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Sample records for apc mutant mice

  1. PARK2 deletions occur frequently in sporadic colorectal cancer and accelerate adenoma development in Apc mutant mice.

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    Poulogiannis, George; McIntyre, Rebecca E; Dimitriadi, Maria; Apps, John R; Wilson, Catherine H; Ichimura, Koichi; Luo, Feijun; Cantley, Lewis C; Wyllie, Andrew H; Adams, David J; Arends, Mark J

    2010-08-24

    In 100 primary colorectal carcinomas, we demonstrate by array comparative genomic hybridization (aCGH) that 33% show DNA copy number (DCN) loss involving PARK2, the gene encoding PARKIN, the E3 ubiquitin ligase whose deficiency is responsible for a form of autosomal recessive juvenile parkinsonism. PARK2 is located on chromosome 6 (at 6q25-27), a chromosome with one of the lowest overall frequencies of DNA copy number alterations recorded in colorectal cancers. The PARK2 deletions are mostly focal (31% approximately 0.5 Mb on average), heterozygous, and show maximum incidence in exons 3 and 4. As PARK2 lies within FRA6E, a large common fragile site, it has been argued that the observed DCN losses in PARK2 in cancer may represent merely the result of enforced replication of locally vulnerable DNA. However, we show that deficiency in expression of PARK2 is significantly associated with adenomatous polyposis coli (APC) deficiency in human colorectal cancer. Evidence of some PARK2 mutations and promoter hypermethylation is described. PARK2 overexpression inhibits cell proliferation in vitro. Moreover, interbreeding of Park2 heterozygous knockout mice with Apc(Min) mice resulted in a dramatic acceleration of intestinal adenoma development and increased polyp multiplicity. We conclude that PARK2 is a tumor suppressor gene whose haploinsufficiency cooperates with mutant APC in colorectal carcinogenesis.

  2. Irsogladine maleate, a gastric mucosal protectant, suppresses intestinal polyp development in Apc-mutant mice

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    Onuma, Wakana; Tomono, Susumu; Miyamoto, Shinngo; Fujii, Gen; Hamoya, Takahiro; Fujimoto, Kyoko; Miyoshi, Noriyuki; Fukai, Fumio; Wakabayashi, Keiji; Mutoh, Michihiro

    2016-01-01

    This study aimed to identify gastric mucosal protectants that suppress intestinal tumorigenesis in a mouse model. We chose six gastric mucosal protectants (ecabet sodium hydrate, irsogladine maleate, rebamipide, sofalcone, teprenone and troxipide) and examined their effects on the activity of oxidative stress-related transcriptional factors, including AP-1, NF-jB, NRF2, p53 and STAT3, in Caco-2 cells using a luciferase reporter gene assay. Among the six protectants, irsogladine maleate clearly inhibited NF-jB and AP-1 transcriptional activity. Furthermore, the chemopreventive property of irsogladine maleate was examined in a Min mouse model of familial adenomatous polyposis. Treatment with irsogladine maleate at doses of 5 and 50 ppm significantly reduced the number of intestinal polyps to 69% and 66% of the untreated control value, respectively. In these polyps, mRNA levels of the downstream targets of NF-jB, such as IL-1β and IL-6, were decreased by irsogladine maleate treatment. Moreover, the levels of oxidative stress-related markers, reactive carbonyl species, in the livers of Min mice were clearly decreased following the administration of irsogladine maleate. This study demonstrated that irsogladine maleate suppresses intestinal polyp formation in Min mice partly through the NF-jB signaling pathway, thus reducing oxidative stress. PMID:26840084

  3. Irsogladine maleate, a gastric mucosal protectant, suppresses intestinal polyp development in Apc-mutant mice.

    Science.gov (United States)

    Onuma, Wakana; Tomono, Susumu; Miyamoto, Shinngo; Fujii, Gen; Hamoya, Takahiro; Fujimoto, Kyoko; Miyoshi, Noriyuki; Fukai, Fumio; Wakabayashi, Keiji; Mutoh, Michihiro

    2016-02-23

    This study aimed to identify gastric mucosal protectants that suppress intestinal tumorigenesis in a mouse model. We chose six gastric mucosal protectants (ecabet sodium hydrate, irsogladine maleate, rebamipide, sofalcone, teprenone and troxipide) and examined their effects on the activity of oxidative stress-related transcriptional factors, including AP-1, NF-jB, NRF2, p53 and STAT3, in Caco-2 cells using a luciferase reporter gene assay. Among the six protectants, irsogladine maleate clearly inhibited NF-jB and AP-1 transcriptional activity. Furthermore, the chemopreventive property of irsogladine maleate was examined in a Min mouse model of familial adenomatous polyposis. Treatment with irsogladine maleate at doses of 5 and 50 ppm significantly reduced the number of intestinal polyps to 69% and 66% of the untreated control value, respectively. In these polyps, mRNA levels of the downstream targets of NF-jB, such as IL-1β and IL-6, were decreased by irsogladine maleate treatment. Moreover, the levels of oxidative stress-related markers, reactive carbonyl species, in the livers of Min mice were clearly decreased following the administration of irsogladine maleate. This study demonstrated that irsogladine maleate suppresses intestinal polyp formation in Min mice partly through the NF-jB signaling pathway, thus reducing oxidative stress.

  4. A new conditional Apc-mutant mouse model for colorectal cancer.

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    Robanus-Maandag, Els C; Koelink, Pim J; Breukel, Cor; Salvatori, Daniela C F; Jagmohan-Changur, Shantie C; Bosch, Cathy A J; Verspaget, Hein W; Devilee, Peter; Fodde, Riccardo; Smits, Ron

    2010-05-01

    Mutations of the adenomatous polyposis coli (APC) gene predispose individuals to familial adenomatous polyposis (FAP), characterized by multiple tumours in the large intestine. Most mouse models heterozygous for truncating mutant Apc alleles mimic FAP, however, the intestinal tumours occur mainly in the small intestine. To model large intestinal tumours, we generated a new conditional Apc-mutant allele, Apc(15lox), with exon 15 flanked by loxP sites. Similar survival of Apc(1638N/15lox) and Apc(1638N/+) mice indicated that the normal function of Apc was not impaired by the loxP sites. Deletion of exon 15, encoding nearly all functional Apc domains and containing the polyadenylation signal, resulted in a mutant allele expressing low levels of a 74 kDa truncated Apc protein. Germ line Cre-mediated deletion of exon 15 resulted in Apc(Delta15/+) mice, showing a severe Apc(Min/+)-like phenotype characterized by multiple tumours in the small intestine and early lethality. In contrast, conditional Cre-mediated deletion of exon 15 specifically directed to the epithelia of distal small and large intestine of FabplCre;Apc(15lox/+) mice led to longer survival and to tumours that developed predominantly in the large intestine, mimicking human FAP-associated colorectal cancer and sporadic colorectal cancer. We conclude that the FabplCre;Apc(15lox/+) mouse should be an attractive model for studies on prevention and treatment of colorectal cancer.

  5. A new conditional Apc-mutant mouse model for colorectal cancer.

    OpenAIRE

    Robanus-Maandag, E C; Koelink, P J; Breukel, C; Salvatori, D. C. F.; Jagmohan-Changur, S. C.; Bosch, C. A. J.; Verspaget, H. W.; Devilee, P; Fodde, R.; Smits, R

    2010-01-01

    textabstractMutations of the adenomatous polyposis coli (APC) gene predispose individuals to familial adenomatous polyposis (FAP), characterized by multiple tumours in the large intestine. Most mouse models heterozygous for truncating mutant Apc alleles mimic FAP, however, the intestinal tumours occur mainly in the small intestine. To model large intestinal tumours, we generated a new conditional Apc-mutant allele, Apc15lox, with exon 15 flanked by loxP sites. Similar survival of Apc1638N/15l...

  6. Selective targeting of mutant adenomatous polyposis coli (APC) in colorectal cancer.

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    Zhang, Lu; Theodoropoulos, Panayotis C; Eskiocak, Ugur; Wang, Wentian; Moon, Young-Ah; Posner, Bruce; Williams, Noelle S; Wright, Woodring E; Kim, Sang Bum; Nijhawan, Deepak; De Brabander, Jef K; Shay, Jerry W

    2016-10-19

    Mutations in the adenomatous polyposis coli (APC) gene are common in colorectal cancer (CRC), and more than 90% of those mutations generate stable truncated gene products. We describe a chemical screen using normal human colonic epithelial cells (HCECs) and a series of oncogenically progressed HCECs containing a truncated APC protein. With this screen, we identified a small molecule, TASIN-1 (truncated APC selective inhibitor-1), that specifically kills cells with APC truncations but spares normal and cancer cells with wild-type APC. TASIN-1 exerts its cytotoxic effects through inhibition of cholesterol biosynthesis. In vivo administration of TASIN-1 inhibits tumor growth of CRC cells with truncated APC but not APC wild-type CRC cells in xenograft models and in a genetically engineered CRC mouse model with minimal toxicity. TASIN-1 represents a potential therapeutic strategy for prevention and intervention in CRC with mutant APC.

  7. Role of P-selectin in intestinal tumorigenesis in ApcMin/+ mice%P-选择素对ApcMin/+小鼠肠道肿瘤的作用

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    郭四美; 亓翠玲; 叶杰; 周秦; 王丽京

    2012-01-01

    ADM: To investigate the role of P ?selectin in intestinal tumorigenesis in Ape Min/+ mice ( C57BL/ 6J -ApcMin/J ). METHODS: Female P - selectin knockout mice ( B6. 129S7 - Selptml Bay/J, that was P - selectin-/- ) were mated with male ApcMin/+ mice. The offspring was genotyped for Min+/- and P -selectin null mutantions, which were ApcMin/+ P - selectin-/- ~ mice. The tumor number and gross tumor volume in the small and large intestines of the ApcMin/ + P - selectin -/- mice and ApcMin/ + mice were determined. RESULTS: P - selectin deficiency in ApcMin/ + mice resulted in significant decreases in the tumor number and gross tumor volume in the small intestine and total intestine. CONCLUSION : Deletion of P - selectin significantly inhibits the tumorigenesis in mouse intestines. In addition, the results also suggest that P - selectin may be a marker for colon cancer.%目的:研究P-选择素(P-selectin)在ApcMin/+小鼠肠道肿瘤中的作用.方法:采用P-selectin基因缺失的基因工程小鼠和肠道肿瘤模型ApcMin/+小鼠杂交,计数ApcMin/+小鼠与ApcMin/+ P-selectin-/-杂交小鼠小肠及大肠肿瘤的数目,并测量其肿瘤体积,研究P-selectin对ApcMin/+小鼠肠道肿瘤的作用.结果:与ApcMin/+小鼠相比,ApcMin/+ P-selectin-/-杂交小鼠在9周龄时肠道肿瘤数目与总负荷明显减少.结论:P-selectin缺失能够显著抑制ApcMin/+小鼠肠道肿瘤的生长.

  8. A new conditional Apc-mutant mouse model for colorectal cancer

    NARCIS (Netherlands)

    E.C. Robanus-Maandag (Els); P.J. Koelink (Pim); C. Breukel (Cor); D.C.F. Salvatori (Daniela); S.C. Jagmohan-Changur (Shantie); C.A.J. Bosch (Cathy); H.W. Verspaget; P. Devilee (Peter); R. Fodde (Riccardo); M.J.M. Smits (Ron)

    2010-01-01

    textabstractMutations of the adenomatous polyposis coli (APC) gene predispose individuals to familial adenomatous polyposis (FAP), characterized by multiple tumours in the large intestine. Most mouse models heterozygous for truncating mutant Apc alleles mimic FAP, however, the intestinal tumours occ

  9. Oncogenic mutations in adenomatous polyposis coli (Apc activate mechanistic target of rapamycin complex 1 (mTORC1 in mice and zebrafish

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    Alexander J. Valvezan

    2014-01-01

    Full Text Available Truncating mutations in adenomatous polyposis coli (APC are strongly linked to colorectal cancers. APC is a negative regulator of the Wnt pathway and constitutive Wnt activation mediated by enhanced Wnt–β-catenin target gene activation is believed to be the predominant mechanism responsible for APC mutant phenotypes. However, recent evidence suggests that additional downstream effectors contribute to APC mutant phenotypes. We previously identified a mechanism in cultured human cells by which APC, acting through glycogen synthase kinase-3 (GSK-3, suppresses mTORC1, a nutrient sensor that regulates cell growth and proliferation. We hypothesized that truncating Apc mutations should activate mTORC1 in vivo and that mTORC1 plays an important role in Apc mutant phenotypes. We find that mTORC1 is strongly activated in apc mutant zebrafish and in intestinal polyps in Apc mutant mice. Furthermore, mTORC1 activation is essential downstream of APC as mTORC1 inhibition partially rescues Apc mutant phenotypes including early lethality, reduced circulation and liver hyperplasia. Importantly, combining mTORC1 and Wnt inhibition rescues defects in morphogenesis of the anterior-posterior axis that are not rescued by inhibition of either pathway alone. These data establish mTORC1 as a crucial, β-catenin independent effector of oncogenic Apc mutations and highlight the importance of mTORC1 regulation by APC during embryonic development. Our findings also suggest a new model of colorectal cancer pathogenesis in which mTORC1 is activated in parallel with Wnt/β-catenin signaling.

  10. Metabolomics of Apc Min/+ mice genetically susceptible to intestinal cancer

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    2014-01-01

    Background To determine how diets high in saturated fat could increase polyp formation in the mouse model of intestinal neoplasia, Apc Min/+ , we conducted large-scale metabolome analysis and association study of colon and small intestine polyp formation from plasma and liver samples of Apc Min/+ vs. wild-type littermates, kept on low vs. high-fat diet. Label-free mass spectrometry was used to quantify untargeted plasma and acyl-CoA liver compounds, respectively. Differences in contrasts of interest were analyzed statistically by unsupervised and supervised modeling approaches, namely Principal Component Analysis and Linear Model of analysis of variance. Correlation between plasma metabolite concentrations and polyp numbers was analyzed with a zero-inflated Generalized Linear Model. Results Plasma metabolome in parallel to promotion of tumor development comprises a clearly distinct profile in Apc Min/+ mice vs. wild type littermates, which is further altered by high-fat diet. Further, functional metabolomics pathway and network analyses in Apc Min/+ mice on high-fat diet revealed associations between polyp formation and plasma metabolic compounds including those involved in amino-acids metabolism as well as nicotinamide and hippuric acid metabolic pathways. Finally, we also show changes in liver acyl-CoA profiles, which may result from a combination of Apc Min/+ -mediated tumor progression and high fat diet. The biological significance of these findings is discussed in the context of intestinal cancer progression. Conclusions These studies show that high-throughput metabolomics combined with appropriate statistical modeling and large scale functional approaches can be used to monitor and infer changes and interactions in the metabolome and genome of the host under controlled experimental conditions. Further these studies demonstrate the impact of diet on metabolic pathways and its relation to intestinal cancer progression. Based on our results, metabolic signatures

  11. Fas/CD95 deficiency in ApcMin/+ mice increases intestinal tumor burden.

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    Hector Guillen-Ahlers

    Full Text Available BACKGROUND: Fas, a member of the tumor necrosis family, is responsible for initiating the apoptotic pathway when bound to its ligand, Fas-L. Defects in the Fas-mediated apoptotic pathway have been reported in colorectal cancer. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, a variant of the Apc(Min/+ mouse, a model for the human condition, Familial Adenomatous Polyposis (FAP, was generated with an additional deficiency of Fas (Apc(Min/+/Fas(lpr by cross-breeding Apc(Min/+ mice with Fas deficient (Fas(lpr mice. One of the main limitations of the Apc(Min/+ mouse model is that it only develops benign polyps. However, Apc(Min/+/Fas(lpr mice presented with a dramatic increase in tumor burden relative to Apc(Min/+ mice and invasive lesions at advanced ages. Proliferation and apoptosis markers revealed an increase in cellular proliferation, but negligible changes in apoptosis, while p53 increased at early ages. Fas-L was lower in Apc(Min/+/Fas(lpr mice relative to Apc(Min/+ cohorts, which resulted in enhanced inflammation. CONCLUSIONS/SIGNIFICANCE: This study demonstrated that imposition of a Fas deletion in an Apc(Min/+ background results in a more aggressive phenotype of the Apc(Min/+ mouse model, with more rapid development of invasive intestinal tumors and a decrease in Fas-L levels.

  12. Apc-Mutant Kyoto Apc Delta (KAD) Rats Are Susceptible to 4-NQO-Induced Tongue Carcinogenesis

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    Tanaka, Takuji, E-mail: tmntt08@gmail.com [Department of Diagnostic Pathology (DDP) & Research Center of Diagnostic Pathology (RC-DiP), Gifu Municipal Hospital, 7-1 Kashima-Cho, Gifu 500-8513 (Japan); Department of Tumor Pathology, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu 501-1194 (Japan); Shimizu, Masahito; Kochi, Takahiro; Shirakami, Yohei [Department of Internal Medicine/Gastroenterology, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu 501-1194 (Japan); Mori, Takayuki [Department of Pharmacy, Ogaki Municipal Hospital, 4-86 Minaminokawa-cho, Ogaki 503-8502 (Japan); Watanabe, Naoki [Department of Diagnostic Pathology (DDP) & Research Center of Diagnostic Pathology (RC-DiP), Gifu Municipal Hospital, 7-1 Kashima-Cho, Gifu 500-8513 (Japan); Naiki, Takafumi [Department of Clinical Laboratory, Gifu Municipal Hospital, 7-1 Kashima-cho, Gifu 500-8513 (Japan); Moriwaki, Hisataka [Department of Internal Medicine/Gastroenterology, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu 501-1194 (Japan); Yoshimi, Kazuto; Serikawa, Tadao; Kuramoto, Takashi [The Institute of Laboratory Animals, Graduate School of Medicine, Kyoto University, Yoshidakonoe-cho, Sakyo-ku, Kyoto 606-8501 (Japan)

    2014-07-21

    Despite widening interest in the possible association between infection/inflammation and cancer development, knowledge of this issue in relation to oral cancer remains inadequate. This study aimed to determine the susceptibility of Apc-mutant Kyoto Apc Delta (KAD) rats, which are vulnerable to developing inflammation-associated colorectal carcinogenesis, to 4-nitroquinoline 1-oxide (4-NQO)-induced tongue carcinogenesis in order to clarify the role of inflammation in oral cancer. KAD (20 males and 22 females) and F344/NS1c (22 males and 23 females) rats received drinking water with or without 4-NQO (20 ppm) for eight weeks. Histopathological and immunohistochemical analyses of the tongue were performed at week 20. Additionally, the mRNA expression of inflammatory cytokines in the tongue mucosa was determined at week 8. Tongue squamous cell carcinoma (SCC) developed in the KAD and F344/NS1c rats that received 4-NQO. Regardless of gender, the incidence and multiplicity of tongue SCC were greater in the KAD rats than in the F344/NS1c rats. In addition, the multiplicity of tongue SCC in the female KAD rats was significantly greater than that observed in the male KAD (p < 0.01) and female F344/NS1c rats (p < 0.05). The levels of inflammation and the mRNA expression of inflammatory cytokines in the tongue in the 4-NQO-treated female KAD rats were the highest among the rats given 4-NQO. These results show that KAD rats, particularly females, are susceptible to 4-NQO-induced tongue carcinogenesis, suggesting the utility of models employing KAD rats for investigating the pathobiology of oral (tongue) carcinogenesis associated with inflammation.

  13. Apc-Mutant Kyoto Apc Delta (KAD Rats Are Susceptible to 4-NQO-Induced Tongue Carcinogenesis

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    Takuji Tanaka

    2014-07-01

    Full Text Available Despite widening interest in the possible association between infection/ inflammation and cancer development, knowledge of this issue in relation to oral cancer remains inadequate. This study aimed to determine the susceptibility of Apc-mutant Kyoto Apc Delta (KAD rats, which are vulnerable to developing inflammation-associated colorectal carcinogenesis, to 4-nitroquinoline 1-oxide (4-NQO-induced tongue carcinogenesis in order to clarify the role of inflammation in oral cancer. KAD (20 males and 22 females and F344/NS1c (22 males and 23 females rats received drinking water with or without 4-NQO (20 ppm for eight weeks. Histopathological and immunohistochemical analyses of the tongue were performed at week 20. Additionally, the mRNA expression of inflammatory cytokines in the tongue mucosa was determined at week 8. Tongue squamous cell carcinoma (SCC developed in the KAD and F344/NS1c rats that received 4-NQO. Regardless of gender, the incidence and multiplicity of tongue SCC were greater in the KAD rats than in the F344/NS1c rats. In addition, the multiplicity of tongue SCC in the female KAD rats was significantly greater than that observed in the male KAD (p < 0.01 and female F344/NS1c rats (p < 0.05. The levels of inflammation and the mRNA expression of inflammatory cytokines in the tongue in the 4-NQO-treated female KAD rats were the highest among the rats given 4-NQO. These results show that KAD rats, particularly females, are susceptible to 4-NQO-induced tongue carcinogenesis, suggesting the utility of models employing KAD rats for investigating the pathobiology of oral (tongue carcinogenesis associated with inflammation.

  14. Complete deletion of Apc results in severe polyposis in mice

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    Cheung, Ann F.; Carter, Alia M.; Kostova, Kamena K.; Woodruff, Joseph F.; Crowley, Denise; Bronson, Roderick T; Haigis, Kevin M.; Jacks, Tyler

    2009-01-01

    The adenomatous polyposis coli (APC) gene product is mutated in the vast majority of human colorectal cancers. APC negatively regulates the WNT pathway by aiding in the degradation of β-catenin, which is the transcription factor activated downstream of WNT signaling. APC mutations result in β-catenin stabilization and constitutive WNT pathway activation, leading to aberrant cellular proliferation. APC mutations associated with colorectal cancer commonly fall in a region of the gene termed the...

  15. The utility of Apc-mutant rats in modeling human colon cancer

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    Amy A. Irving

    2014-11-01

    Full Text Available Prior to the advent of genetic engineering in the mouse, the rat was the model of choice for investigating the etiology of cancer. Now, recent advances in the manipulation of the rat genome, combined with a growing recognition of the physiological differences between mice and rats, have reignited interest in the rat as a model of human cancer. Two recently developed rat models, the polyposis in the rat colon (Pirc and Kyoto Apc Delta (KAD strains, each carry mutations in the intestinal-cancer-associated adenomatous polyposis coli (Apc gene. In contrast to mouse models carrying Apc mutations, in which cancers develop mainly in the small intestine rather than in the colon and there is no gender bias, these rat models exhibit colonic predisposition and gender-specific susceptibility, as seen in human colon cancer. The rat also provides other experimental resources as a model organism that are not provided by the mouse: the structure of its chromosomes facilitates the analysis of genomic events, the size of its colon permits longitudinal analysis of tumor growth, and the size of biological samples from the animal facilitates multiplexed molecular analyses of the tumor and its host. Thus, the underlying biology and experimental resources of these rat models provide important avenues for investigation. We anticipate that advances in disease modeling in the rat will synergize with resources that are being developed in the mouse to provide a deeper understanding of human colon cancer.

  16. The utility of Apc-mutant rats in modeling human colon cancer

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    Irving, Amy A.; Yoshimi, Kazuto; Hart, Marcia L.; Parker, Taybor; Clipson, Linda; Ford, Madeline R.; Kuramoto, Takashi; Dove, William F.; Amos-Landgraf, James M.

    2014-01-01

    Prior to the advent of genetic engineering in the mouse, the rat was the model of choice for investigating the etiology of cancer. Now, recent advances in the manipulation of the rat genome, combined with a growing recognition of the physiological differences between mice and rats, have reignited interest in the rat as a model of human cancer. Two recently developed rat models, the polyposis in the rat colon (Pirc) and Kyoto Apc Delta (KAD) strains, each carry mutations in the intestinal-cancer-associated adenomatous polyposis coli (Apc) gene. In contrast to mouse models carrying Apc mutations, in which cancers develop mainly in the small intestine rather than in the colon and there is no gender bias, these rat models exhibit colonic predisposition and gender-specific susceptibility, as seen in human colon cancer. The rat also provides other experimental resources as a model organism that are not provided by the mouse: the structure of its chromosomes facilitates the analysis of genomic events, the size of its colon permits longitudinal analysis of tumor growth, and the size of biological samples from the animal facilitates multiplexed molecular analyses of the tumor and its host. Thus, the underlying biology and experimental resources of these rat models provide important avenues for investigation. We anticipate that advances in disease modeling in the rat will synergize with resources that are being developed in the mouse to provide a deeper understanding of human colon cancer. PMID:25288683

  17. Targeting the DNA replication checkpoint by pharmacologic inhibition of Chk1 kinase: a strategy to sensitize APC mutant colon cancer cells to 5-fluorouracil chemotherapy.

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    Martino-Echarri, Estefania; Henderson, Beric R; Brocardo, Mariana G

    2014-10-30

    5-fluorouracil (5-FU) is the first line component used in colorectal cancer (CRC) therapy however even in combination with other chemotherapeutic drugs recurrence is common. Mutations of the adenomatous polyposis coli (APC) gene are considered as the initiating step of transformation in familial and sporadic CRCs. We have previously shown that APC regulates the cellular response to DNA replication stress and recently hypothesized that APC mutations might therefore influence 5-FU resistance. To test this, we compared CRC cell lines and show that those expressing truncated APC exhibit a limited response to 5-FU and arrest in G1/S-phase without undergoing lethal damage, unlike cells expressing wild-type APC. In SW480 APC-mutant CRC cells, 5-FU-dependent apoptosis was restored after transient expression of full length APC, indicating a direct link between APC and drug response. Furthermore, we could increase sensitivity of APC truncated cells to 5-FU by inactivating the Chk1 kinase using drug treatment or siRNA-mediated knockdown. Our findings identify mutant APC as a potential tumor biomarker of resistance to 5-FU, and importantly we show that APC-mutant CRC cells can be made more sensitive to 5-FU by use of Chk1 inhibitors.

  18. Persistent lung inflammation and fibrosis in serum amyloid P component (APCs-/- knockout mice.

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    Darrell Pilling

    Full Text Available Fibrosing diseases, such as pulmonary fibrosis, cardiac fibrosis, myelofibrosis, liver fibrosis, and renal fibrosis are chronic and debilitating conditions and are an increasing burden for the healthcare system. Fibrosis involves the accumulation and differentiation of many immune cells, including macrophages and fibroblast-like cells called fibrocytes. The plasma protein serum amyloid P component (SAP; also known as pentraxin-2, PTX2 inhibits fibrocyte differentiation in vitro, and injections of SAP inhibit fibrosis in vivo. SAP also promotes the formation of immuno-regulatory Mreg macrophages. To elucidate the endogenous function of SAP, we used bleomycin aspiration to induce pulmonary inflammation and fibrosis in mice lacking SAP. Compared to wildtype C57BL/6 mice, we find that in Apcs-/- "SAP knock-out" mice, bleomycin induces a more persistent inflammatory response and increased fibrosis. In both C57BL/6 and Apcs-/- mice, injections of exogenous SAP reduce the accumulation of inflammatory macrophages and prevent fibrosis. The types of inflammatory cells present in the lungs following bleomycin-aspiration appear similar between C57BL/6 and Apcs-/- mice, suggesting that the initial immune response is normal in the Apcs-/- mice, and that a key endogenous function of SAP is to promote the resolution of inflammation and fibrosis.

  19. Genetic deletion of mPGES-1 accelerates intestinal tumorigenesis in APC(Min/+) mice

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    Elander, N.; Ungerback, J.; Olsson, H.; Uematsu, S.; Akira, S.; Soderkvist, P.

    2008-01-01

    The induced synthesis of bioactive prostanoids downstream of cyclooxygenase-2 (COX-2) and prostaglandin H(2) (PGH(2)) exerts a critical event in colorectal carcinogenesis. Here we demonstrate that APC(Min/+) mice with genetic deletion of microsomal prostaglandin E synthase-1 (mPGES-1), which catalys

  20. Krüppel-like factor 5 is a crucial mediator of intestinal tumorigenesis in mice harboring combined ApcMin and KRASV12 mutations

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    Robine Sylvie

    2010-03-01

    Full Text Available Abstract Background Both mutational inactivation of the adenomatous polyposis coli (APC tumor suppressor gene and activation of the KRAS oncogene are implicated in the pathogenesis of colorectal cancer. Mice harboring a germline ApcMin mutation or intestine-specific expression of the KRASV12 gene have been developed. Both mouse strains develop spontaneous intestinal tumors, including adenoma and carcinoma, though at a different age. The zinc finger transcription factor Krüppel-like factor 5 (KLF5 has previously been shown to promote proliferation of intestinal epithelial cells and modulate intestinal tumorigenesis. Here we investigated the in vivo effect of Klf5 heterozygosity on the propensity of ApcMin/KRASV12 double transgenic mice to develop intestinal tumors. Results At 12 weeks of age, ApcMin/KRASV12 mice had three times as many intestinal tumors as ApcMin mice. This increase in tumor number was reduced by 92% in triple transgenic ApcMin/KRASV12/Klf5+/- mice. The reduction in tumor number in ApcMin/KRASV12/Klf5+/- mice was also statistically significant compared to ApcMin mice alone, with a 75% decrease. Compared with ApcMin/KRASV12, tumors from both ApcMin/KRASV12/Klf5+/- and ApcMin mice were smaller. In addition, tumors from ApcMin mice were more distally distributed in the intestine as contrasted by the more proximal distribution in ApcMin/KRASV12 and ApcMin/KRASV12/Klf5+/- mice. Klf5 levels in the normal-appearing intestinal mucosa were higher in both ApcMin and ApcMin/KRASV12 mice but were attenuated in ApcMin/KRASV12/Klf5+/- mice. The levels of β-catenin, cyclin D1 and Ki-67 were also reduced in the normal-appearing intestinal mucosa of ApcMin/KRASV12/Klf5+/- mice when compared to ApcMin/KRASV12 mice. Levels of pMek and pErk1/2 were elevated in the normal-appearing mucosa of ApcMin/KRASV12 mice and modestly reduced in ApcMin/KRASV12/Klf5+/- mice. Tumor tissues displayed higher levels of both Klf5 and β-catenin, irrespective of the

  1. Curcumin suppresses intestinal polyps in APC Min mice fed a high fat diet

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    Christina Pettan-Brewer

    2011-06-01

    Full Text Available Colorectal cancer (CRC is a leading cause of cancer deaths in the United States. Various risk factors have been associated with CRC including increasing age and diet. Epidemiological and experimental studies have implicated a diet high in fat as an important risk factor for colon cancer. High fat diets can promote obesity resulting in insulin resistance and inflammation and the development of oxidative stress, increased cell proliferation, and suppression of apoptosis. Because of the high consumption of dietary fats, especially saturated fats, by Western countries, it is of interest to see if non-nutrient food factors might be effective in preventing or delaying CRC in the presence of high saturated fat intake. Curcumin (Curcuma longa, the main yellow pigment in turmeric, was selected to test because of its reported anti-tumor activity. APC Min mice, which develop intestinal polyps and have many molecular features of CRC, were fed a diet containing 35% pork fat, 33% sucrose, and a protein and vitamin mineral mixture (HFD with or without 0.5% curcumin. These cohorts were compared to APC Min mice receiving standard rodent chow (RC with 8% fat. APC Min mice fed the HFD for 3 months had a 23% increase in total number of polyps compared to APC Min mice on RC. Curcumin was able to significantly reverse the accelerated polyp development associated with the HFD suggesting it may be effective clinically in helping prevent colon cancer even when ingesting high amounts of fatty foods. The anti-tumor effect of curcumin was shown to be associated with enhanced apoptosis and increased efficiency of DNA repair. Since curcumin prevented the gain in body weight seen in APC Min mice ingesting the HFD, modulation of energy metabolism may also be a factor.

  2. A novel approach to assess the spontaneous gastrointestinal bleeding risk of antithrombotic agents using Apc(min/+) mice.

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    Wei, Huijun; Shang, Jin; Keohane, CarolAnn; Wang, Min; Li, Qiu; Ni, Weihua; O'Neill, Kim; Chintala, Madhu

    2014-06-01

    Assessment of the bleeding risk of antithrombotic agents is usually performed in healthy animals with some form of vascular injury to peripheral organs to induce bleeding. However, bleeding observed in patients with currently marketed antithrombotic drugs is typically spontaneous in nature such as intracranial haemorrhage (ICH) and gastrointestinal (GI) bleeding, which happens most frequently on top of preexisting pathologies such as GI ulcerations and polyps. Apc(min/+) mice are reported to develop multiple adenomas through the entire intestinal tract and display progressive anaemia.In this study, we evaluated the potential utility of Apc(min/+) mice as a model for assessing spontaneous GI bleeding with antithrombotic agents. Apc(min/+) mice exhibited progressive blood loss starting at the age of nine weeks. Despite the increase in bleeding, Apc(min/+) mice were in a hypercoagulable state and displayed an age-dependent increase in thrombin generation and circulating fibrinogen as well as a significant decrease in clotting times. We evaluated the effect of warfarin, dabigatran etexilate, apixaban and clopidogrel in this model by administering them in diet or in the drinking water to mice for 1-4 weeks. All of these marketed drugs significantly increased GI bleeding in Apc(min/+) mice, but not in wild-type mice. Although different exposure profiles of these antithrombotic agents make it challenging to compare the bleeding risk of compounds, our results indicate that the Apc(min/+) mouse may be a sensitive preclinical model for assessing the spontaneous GI bleeding risk of novel antithrombotic agents.

  3. Chlorinated Water Modulates the Development of Colorectal Tumors with Chromosomal Instability and Gut Microbiota in Apc-Deficient Mice.

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    Sasada, Tatsunari; Hinoi, Takao; Saito, Yasufumi; Adachi, Tomohiro; Takakura, Yuji; Kawaguchi, Yasuo; Sotomaru, Yusuke; Sentani, Kazuhiro; Oue, Naohide; Yasui, Wataru; Ohdan, Hideki

    2015-01-01

    The gastrointestinal tract is continuously exposed to a variety of chemicals and commensal bacteria. Recent studies have shown that changes in gut microbial populations caused by chlorine or other chemicals in the drinking water influence the development of human colorectal cancer, although the mechanism of tumorigenesis in the gut epithelium is obfuscated by the diversity of microflora and complexity of the tumor microenvironment. In this regard, mouse models that recapitulate human colorectal cancer are an invaluable tool. In this study, we used two conditional adenomatous polyposis coli (Apc) knockout mouse models to investigate the effect of chlorinated water on tumorigenesis in the digestive tract. Mice with colon-specific carcinoma--caused by either chromosomal (CDX2P 9.5-NLS Cre;Apc(+/flox), abbreviated to CPC;Apc) or microsatellite (CDX2P9.5-G19Cre;Apc(flox/flox) and CDX2P9.5-G22Cre;Apc(flox/flox)) instability, respectively--were administered chlorinated (10.0 mg/L chlorine) or tap (0.7 mg/L chlorine) water and evaluated for colon polyp formation. In CPC;Apc mice given chlorinated drinking water, tumors tended to develop in the colon, whereas in those that drank tap water, tumors were mostly observed in the small intestine. There was no difference in the rate of tumor formation of CDX2P9.5-G19Cre;Apc(flox/flox) and CDX2P9.5-G22Cre;Apc(flox/flox) mice consuming chlorinated as compared to tap water, suggesting that microsatellite instability in the Apc gene does not significantly affect tumorigenesis. Chlorinated water altered the enteric environment by reducing the fecal populations of the obligatory anaerobes Clostridium perfringens and C. difficile, as well as species belonging to the Atopobium cluster, including Enterobacteriaceae and Staphylococcus sp., which was associated with colon tumorigenesis in CPC;Apc mice. These results suggest that differences in tumorigenesis among CPC;Apc mice consuming chlorinated versus tap water may be due to differences

  4. Chlorinated Water Modulates the Development of Colorectal Tumors with Chromosomal Instability and Gut Microbiota in Apc-Deficient Mice.

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    Tatsunari Sasada

    Full Text Available The gastrointestinal tract is continuously exposed to a variety of chemicals and commensal bacteria. Recent studies have shown that changes in gut microbial populations caused by chlorine or other chemicals in the drinking water influence the development of human colorectal cancer, although the mechanism of tumorigenesis in the gut epithelium is obfuscated by the diversity of microflora and complexity of the tumor microenvironment. In this regard, mouse models that recapitulate human colorectal cancer are an invaluable tool. In this study, we used two conditional adenomatous polyposis coli (Apc knockout mouse models to investigate the effect of chlorinated water on tumorigenesis in the digestive tract. Mice with colon-specific carcinoma--caused by either chromosomal (CDX2P 9.5-NLS Cre;Apc(+/flox, abbreviated to CPC;Apc or microsatellite (CDX2P9.5-G19Cre;Apc(flox/flox and CDX2P9.5-G22Cre;Apc(flox/flox instability, respectively--were administered chlorinated (10.0 mg/L chlorine or tap (0.7 mg/L chlorine water and evaluated for colon polyp formation. In CPC;Apc mice given chlorinated drinking water, tumors tended to develop in the colon, whereas in those that drank tap water, tumors were mostly observed in the small intestine. There was no difference in the rate of tumor formation of CDX2P9.5-G19Cre;Apc(flox/flox and CDX2P9.5-G22Cre;Apc(flox/flox mice consuming chlorinated as compared to tap water, suggesting that microsatellite instability in the Apc gene does not significantly affect tumorigenesis. Chlorinated water altered the enteric environment by reducing the fecal populations of the obligatory anaerobes Clostridium perfringens and C. difficile, as well as species belonging to the Atopobium cluster, including Enterobacteriaceae and Staphylococcus sp., which was associated with colon tumorigenesis in CPC;Apc mice. These results suggest that differences in tumorigenesis among CPC;Apc mice consuming chlorinated versus tap water may be due to

  5. Chemopreventive Effects of RXR-Selective Rexinoid Bexarotene on Intestinal Neoplasia of ApcMin/+ Mice

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    Naveena B. Janakiram

    2012-02-01

    Full Text Available Retinoid X receptor (RXR has been implicated in several neoplastic diseases. Previously, we have shown that RXR-α is downregulated in human and rodent colonic tumors, suggesting a potential target for colon cancer prevention (http://www.cancer.org/Cancer/ColonandRectumCancer/DetailedGuide/colorectal-cancer-key-statistics. Experiments were designed to assess the chemopreventive efficacy of the selective RXR agonist bexarotene for the suppression of intestinal tumorigenesis in ApcMin/+ mice. Before the efficacy studies, we determined that the maximal tolerated dose in C57BL/6J mice was less than 400 ppm. For the efficacy study, 6-week-old male and female C57BL/6J-ApcMin/+ mice (nine mice per group were fed diets containing 0, 30, and 60 ppm of bexarotene or 200 ppm of bexarotene for 80 days before intestinal tumors were evaluated. Dietary administration of 30 and 60 ppm of bexarotene suppressed the intestinal polyp formation by 38% (P < .015 and 60% (P < .0001 in males, respectively, and by 8.5% and 37% (P < .007 in females, respectively. Also, significant inhibition (50%–100% of colonic tumor formation was observed in both male and female mice with bexarotene treatment. Administration of 200 ppm of bexarotene showed significant suppression of tumor formation (66%, P < .0001; however, it had significant toxicity. Intestinal tumors of bexarotene-fed mice showed significantly reduced expression of proliferating cell nuclear antigen (60%, P < .0001, cyclin D1, and cyclooxygenase 2 and increased RXR-α messenger RNA and uptake of oleate (34%, P < .01. Also, bexarotene-fed mice showed dose-dependent suppression of serum triglycerides (25%–72%, P < .0001 and inflammatory cytokines.

  6. Muscle development in mdx mutant mice.

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    Dangain, J; Vrbova, G

    1984-01-01

    Mechanical and contractile properties of tibialis anterior (TA) muscles from X-linked muscular dystrophic (mdx) mutant mice at different stages of development are compared to those of muscles from normal control animals. There is no difference between the tension output, speeds of contraction and relaxation, and weight of TA muscles from mutant adults and normal control animals. However, it is found that in 3-4-week-old mutant animals, tension output and muscle weight are very much reduced, and half relaxation time is prolonged. Thus, during this stage of development, muscles from mdx mice do not function properly. Histological examination of these muscles provides further evidence that, in these animals, rapid muscle destruction occurs at a particular time of development and that it is followed by complete recovery. This new mutant therefore presents an interesting case of muscle destruction and rapid regeneration. However, it is not an adequate model for Duchenne muscular dystrophy.

  7. Liver inflammation and metabolic signaling in ApcMin/+ mice: the role of cachexia progression.

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    Aditi A Narsale

    Full Text Available The ApcMin/+ mouse exhibits an intestinal tumor associated loss of muscle and fat that is accompanied by chronic inflammation, insulin resistance and hyperlipidemia. Since the liver governs systemic energy demands through regulation of glucose and lipid metabolism, it is likely that the liver is a pathological target of cachexia progression in the ApcMin/+ mouse. The purpose of this study was to determine if cancer and the progression of cachexia affected liver endoplasmic reticulum (ER-stress, inflammation, metabolism, and protein synthesis signaling. The effect of cancer (without cachexia was examined in wild-type and weight-stable ApcMin/+ mice. Cachexia progression was examined in weight-stable, pre-cachectic, and severely-cachectic ApcMin/+ mice. Livers were analyzed for morphology, glycogen content, ER-stress, inflammation, and metabolic changes. Cancer induced hepatic expression of ER-stress markers BiP (binding immunoglobulin protein, IRE-1α (endoplasmic reticulum to nucleus signaling 1, and inflammatory intermediate STAT-3 (signal transducer and activator of transcription 3. While gluconeogenic enzyme phosphoenolpyruvate carboxykinase (PEPCK mRNA expression was suppressed by cancer, glycogen content or protein synthesis signaling remained unaffected. Cachexia progression depleted liver glycogen content and increased mRNA expression of glycolytic enzyme PFK (phosphofrucktokinase and gluconeogenic enzyme PEPCK. Cachexia progression further increased pSTAT-3 but suppressed p-65 and JNK (c-Jun NH2-terminal kinase activation. Interestingly, progression of cachexia suppressed upstream ER-stress markers BiP and IRE-1α, while inducing its downstream target CHOP (DNA-damage inducible transcript 3. Cachectic mice exhibited a dysregulation of protein synthesis signaling, with an induction of p-mTOR (mechanistic target of rapamycin, despite a suppression of Akt (thymoma viral proto-oncogene 1 and S6 (ribosomal protein S6 phosphorylation. Thus

  8. Liver inflammation and metabolic signaling in ApcMin/+ mice: the role of cachexia progression.

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    Narsale, Aditi A; Enos, Reilly T; Puppa, Melissa J; Chatterjee, Saurabh; Murphy, E Angela; Fayad, Raja; Pena, Majorette O'; Durstine, J Larry; Carson, James A

    2015-01-01

    The ApcMin/+ mouse exhibits an intestinal tumor associated loss of muscle and fat that is accompanied by chronic inflammation, insulin resistance and hyperlipidemia. Since the liver governs systemic energy demands through regulation of glucose and lipid metabolism, it is likely that the liver is a pathological target of cachexia progression in the ApcMin/+ mouse. The purpose of this study was to determine if cancer and the progression of cachexia affected liver endoplasmic reticulum (ER)-stress, inflammation, metabolism, and protein synthesis signaling. The effect of cancer (without cachexia) was examined in wild-type and weight-stable ApcMin/+ mice. Cachexia progression was examined in weight-stable, pre-cachectic, and severely-cachectic ApcMin/+ mice. Livers were analyzed for morphology, glycogen content, ER-stress, inflammation, and metabolic changes. Cancer induced hepatic expression of ER-stress markers BiP (binding immunoglobulin protein), IRE-1α (endoplasmic reticulum to nucleus signaling 1), and inflammatory intermediate STAT-3 (signal transducer and activator of transcription 3). While gluconeogenic enzyme phosphoenolpyruvate carboxykinase (PEPCK) mRNA expression was suppressed by cancer, glycogen content or protein synthesis signaling remained unaffected. Cachexia progression depleted liver glycogen content and increased mRNA expression of glycolytic enzyme PFK (phosphofrucktokinase) and gluconeogenic enzyme PEPCK. Cachexia progression further increased pSTAT-3 but suppressed p-65 and JNK (c-Jun NH2-terminal kinase) activation. Interestingly, progression of cachexia suppressed upstream ER-stress markers BiP and IRE-1α, while inducing its downstream target CHOP (DNA-damage inducible transcript 3). Cachectic mice exhibited a dysregulation of protein synthesis signaling, with an induction of p-mTOR (mechanistic target of rapamycin), despite a suppression of Akt (thymoma viral proto-oncogene 1) and S6 (ribosomal protein S6) phosphorylation. Thus, cancer

  9. Aging Kit mutant mice develop cardiomyopathy.

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    Lei Ye

    Full Text Available Both bone marrow (BM and myocardium contain progenitor cells expressing the c-Kit tyrosine kinase. The aims of this study were to determine the effects of c-Kit mutations on: i. myocardial c-Kit(+ cells counts and ii. the stability of left ventricular (LV contractile function and structure during aging. LV structure and contractile function were evaluated (echocardiography in two groups of Kit mutant (W/Wv and W41/W42 and in wild type (WT mice at 4 and 12 months of age and the effects of the mutations on LV mass, vascular density and the numbers of proliferating cells were also determined. In 4 month old Kit mutant and WT mice, LV ejection fractions (EF and LV fractional shortening rates (FS were comparable. At 12 months of age EF and FS were significantly decreased and LV mass was significantly increased only in W41/W42 mice. Myocardial vascular densities and c-Kit(+ cell numbers were significantly reduced in both mutant groups when compared to WT hearts. Replacement of mutant BM with WT BM at 4 months of age did not prevent these abnormalities in either mutant group although they were somewhat attenuated in the W/Wv group. Notably BM transplantation did not prevent the development of cardiomyopathy in 12 month W41/W42 mice. The data suggest that decreased numbers and functional capacities of c-Kit(+ cardiac resident progenitor cells may be the basis of the cardiomyopathy in W41/W42 mice and although defects in mutant BM progenitor cells may prove to be contributory, they are not causal.

  10. Acceleration of intestinal polyposis through prostaglandin receptor EP2 in Apc(Delta 716) knockout mice.

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    Sonoshita, M; Takaku, K; Sasaki, N; Sugimoto, Y; Ushikubi, F; Narumiya, S; Oshima, M; Taketo, M M

    2001-09-01

    Arachidonic acid is metabolized to prostaglandin H(2) (PGH(2)) by cyclooxygenase (COX). COX-2, the inducible COX isozyme, has a key role in intestinal polyposis. Among the metabolites of PGH(2), PGE(2) is implicated in tumorigenesis because its level is markedly elevated in tissues of intestinal adenoma and colon cancer. Here we show that homozygous deletion of the gene encoding a cell-surface receptor of PGE(2), EP2, causes decreases in number and size of intestinal polyps in Apc(Delta 716) mice (a mouse model for human familial adenomatous polyposis). This effect is similar to that of COX-2 gene disruption. We also show that COX-2 expression is boosted by PGE(2) through the EP2 receptor via a positive feedback loop. Homozygous gene knockout for other PGE(2) receptors, EP1 or EP3, did not affect intestinal polyp formation in Apc(Delta 716) mice. We conclude that EP2 is the major receptor mediating the PGE2 signal generated by COX-2 upregulation in intestinal polyposis, and that increased cellular cAMP stimulates expression of more COX-2 and vascular endothelial growth factor in the polyp stroma.

  11. Selenium and sulindac are synergistic to inhibit intestinal tumorigenesis in Apc/p21 mice

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    Bi Xiuli

    2013-01-01

    Full Text Available Abstract Background Both selenium and non-steroidal anti-inflammatory drug (NSAID sulindac are effective in cancer prevention, but their effects are affected by several factors including epigenetic alterations and gene expression. The current study was designed to determine the effects of the combination of selenium and sulindac on tumor inhibition and the underlying mechanisms. Results We fed the intestinal tumor model Apc/p21 mice with selenium- and sulindac-supplemented diet for 24 weeks, and found that the combination of selenium and sulindac significantly inhibited intestinal tumorigenesis, in terms of reducing tumor incidence by 52% and tumor multiplicities by 80% (p Conclusions The selenium is synergistic with sulindac to exert maximal effects on tumor inhibition. This finding provides an important chemopreventive strategy using combination of anti-cancer agents, which has a great impact on cancer prevention and has a promising translational potential.

  12. Use of a chemically induced-colon carcinogenesis-prone Apc-mutant rat in a chemotherapeutic bioassay

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    Yoshimi Kazuto

    2012-10-01

    Full Text Available Abstract Background Chemotherapeutic bioassay for colorectal cancer (CRC with a rat model bearing chemically-induced CRCs plays an important role in the development of new anti-tumor drugs and regimens. Although several protocols to induce CRCs have been developed, the incidence and number of CRCs are not much enough for the efficient bioassay. Recently, we established the very efficient system to induce CRCs with a chemically induced-colon carcinogenesis-prone Apc-mutant rat, Kyoto Apc Delta (KAD rat. Here, we applied the KAD rat to the chemotherapeutic bioassay for CRC and showed the utility of the KAD rat. Methods The KAD rat has been developed by the ENU mutagenesis and carries a homozygous nonsense mutation in the Apc gene (S2523X. Male KAD rats were given a single subcutaneous injection of AOM (20 mg/kg body weight at 5 weeks of age. Starting at 1 week after the AOM injection, they were given 2% DSS in drinking water for 7 days. Tumor-bearing KAD rats were divided into experimental and control groups on the basis of the number of tumors observed by endoscopy at week 8. The 5-fluorouracil (5-FU was administrated intravenously a dose of 50 or 75 mg/kg weekly at week 9, 10, and 11. After one-week interval, the 5-FU was given again at week 13, 14, and 15. At week 16, animals were sacrificed and tumor number and volume were measured macroscopically and microscopically. Results In total 48 tumors were observed in 27 KAD rats with a 100% incidence at week 8. The maximum tolerated dose for the KAD rat was 50 mg/kg of 5-FU. Macroscopically, the number or volume of tumors in the 5-FU treated rats was not significantly different from the control. Microscopically, the number of adenocarcinoma in the 5-FU treated rats was not significantly different (p Conclusion The use of the AOM/DSS-treated tumor-bearing KAD rats could shorten the experimental period and reduce the number of animals examined in the chemotherapeutic bioassay. The

  13. Molecular alterations associated with sulindac-resistant colon tumors in ApcMin/+ mice.

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    Greenspan, Emily J; Nichols, Frank C; Rosenberg, Daniel W

    2010-09-01

    Although nonsteroidal anti-inflammatory drugs (NSAID), including sulindac, have been used extensively as chemopreventive agents for colorectal cancer, results are not consistent. NSAIDs, most reportedly sulindac, often do not cause a complete regression of adenomas and some patients develop resistance to NSAID treatment. In this study, we evaluated the effect of sulindac on colon tumorigenesis in the Apc(Min/+) mouse model. Sulindac (180 ppm) given in drinking water for 9 weeks to Apc(Min/+) mice significantly reduced the size of colon tumors, but actually caused an increase in colon tumor multiplicity relative to untreated controls (average of 5.5 versus 1.6 tumors per mouse, respectively; P sulindac significantly reduced tumor size and multiplicity relative to untreated controls (average of 2.3 versus 42.0 tumors per mouse, respectively; P sulindac treatment. Sulindac is also known to exert its growth inhibitory effects through regulation of many noncyclooxygenase targets, including p21, beta-catenin, E-cadherin, mitochondrial apoptotic proteins, and peroxisome proliferator-activated receptor-gamma. We found that sulindac treatment protected against E-cadherin loss in colon tumors, with associated inhibition of nuclear beta-catenin accumulation. Importantly, p21(WAF1/cip1) and peroxisome proliferator-activated receptor-gamma expression were absent in colon tumors from sulindac-treated mice, suggesting that loss of these proteins is necessary for drug resistance. Together, these observations may be translatable to designing novel clinical therapies using combinations of agents that target multiple molecular pathways to overcome sulindac resistance.

  14. Behavioral characterization of system xc- mutant mice.

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    McCullagh, Elizabeth A; Featherstone, David E

    2014-05-15

    The slc7a11 gene encodes xCT, an essential component of 'system xc-', a plasma membrane exchanger that imports cystine and exports glutamate. Slc7a11 is expressed primarily in the brain, but its role there is not clear. We performed behavioral tests on two different strains of homozygous slc7a11 mutant mice ('sut' and 'xCT'), as well as heteroallelic offspring of these two strains ('xCT/sut') and their associated genetic backgrounds. Homozygous sut mutant males showed reduced spontaneous alternation in spontaneous alternation tasks as well as reduced movement in an open field maze, but xCT and xCT/sut strains did not show significant changes in these tasks compared to appropriate controls. Neither xCT nor sut mutants showed differences from controls in rotarod tests. Female behavioral phenotypes were independent of estrus cycle stage. To ensure that homozygous xCT, sut, and xCT/sut strains all represent protein null alleles, we measured whole brain xCT protein levels using immunoblots. xCT, sut and xCT/sut strains showed no detectable xCT protein expression, confirming them as null alleles. Previously published microdialysis experiments showed reduced striatal glutamate in xCT mutants. Using the same methods, we measured reduced interstitial glutamate levels in the striatum but not cerebellum of sut mutants. However, we detected no glutamate change in the striatum or cerebellum of sut/xCT mice. We detected no changes in whole brain EAAT-1, -2, or -3 expression. We conclude that the behavioral and chemical differences exist between slc7a11 mutant strains, but we were unable to definitively attribute any of these differences to loss of system xc-.

  15. Maslinic Acid-Enriched Diet Decreases Intestinal Tumorigenesis in ApcMin/+ Mice through Transcriptomic and Metabolomic Reprogramming

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    Sánchez-Tena, Susana; Reyes-Zurita, Fernando J.; Díaz-Moralli, Santiago; Vinardell, Maria Pilar; Reed, Michelle; García-García, Francisco; Dopazo, Joaquín; Lupiáñez, José A.; Günther, Ulrich; Cascante, Marta

    2013-01-01

    Chemoprevention is a pragmatic approach to reduce the risk of colorectal cancer, one of the leading causes of cancer-related death in western countries. In this regard, maslinic acid (MA), a pentacyclic triterpene extracted from wax-like coatings of olives, is known to inhibit proliferation and induce apoptosis in colon cancer cell lines without affecting normal intestinal cells. The present study evaluated the chemopreventive efficacy and associated mechanisms of maslinic acid treatment on spontaneous intestinal tumorigenesis in ApcMin/+ mice. Twenty-two mice were randomized into 2 groups: control group and MA group, fed with a maslinic acid–supplemented diet for six weeks. MA treatment reduced total intestinal polyp formation by 45% (P<0.01). Putative molecular mechanisms associated with suppressing intestinal polyposis in ApcMin/+ mice were investigated by comparing microarray expression profiles of MA-treated and control mice and by analyzing the serum metabolic profile using NMR techniques. The different expression phenotype induced by MA suggested that it exerts its chemopreventive action mainly by inhibiting cell-survival signaling and inflammation. These changes eventually induce G1-phase cell cycle arrest and apoptosis. Moreover, the metabolic changes induced by MA treatment were associated with a protective profile against intestinal tumorigenesis. These results show the efficacy and underlying mechanisms of MA against intestinal tumor development in the ApcMin/+ mice model, suggesting its chemopreventive potential against colorectal cancer. PMID:23527181

  16. Maslinic acid-enriched diet decreases intestinal tumorigenesis in Apc(Min/+ mice through transcriptomic and metabolomic reprogramming.

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    Susana Sánchez-Tena

    Full Text Available Chemoprevention is a pragmatic approach to reduce the risk of colorectal cancer, one of the leading causes of cancer-related death in western countries. In this regard, maslinic acid (MA, a pentacyclic triterpene extracted from wax-like coatings of olives, is known to inhibit proliferation and induce apoptosis in colon cancer cell lines without affecting normal intestinal cells. The present study evaluated the chemopreventive efficacy and associated mechanisms of maslinic acid treatment on spontaneous intestinal tumorigenesis in Apc(Min/+ mice. Twenty-two mice were randomized into 2 groups: control group and MA group, fed with a maslinic acid-supplemented diet for six weeks. MA treatment reduced total intestinal polyp formation by 45% (P<0.01. Putative molecular mechanisms associated with suppressing intestinal polyposis in Apc(Min/+ mice were investigated by comparing microarray expression profiles of MA-treated and control mice and by analyzing the serum metabolic profile using NMR techniques. The different expression phenotype induced by MA suggested that it exerts its chemopreventive action mainly by inhibiting cell-survival signaling and inflammation. These changes eventually induce G1-phase cell cycle arrest and apoptosis. Moreover, the metabolic changes induced by MA treatment were associated with a protective profile against intestinal tumorigenesis. These results show the efficacy and underlying mechanisms of MA against intestinal tumor development in the Apc(Min/+ mice model, suggesting its chemopreventive potential against colorectal cancer.

  17. Mapping pathological phenotypes in reelin mutant mice.

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    Michetti, Caterina; Romano, Emilia; Altabella, Luisa; Caruso, Angela; Castelluccio, Paolo; Bedse, Gaurav; Gaetani, Silvana; Canese, Rossella; Laviola, Giovanni; Scattoni, Maria Luisa

    2014-01-01

    Autism Spectrum Disorders (ASD) are neurodevelopmental disorders with multifactorial origin characterized by social communication deficits and the presence of repetitive behaviors/interests. Several studies showed an association between the reelin gene mutation and increased risk of ASD and a reduced reelin expression in some brain regions of ASD subjects, suggesting a role for reelin deficiency in ASD etiology. Reelin is a large extracellular matrix glycoprotein playing important roles during development of the central nervous system. To deeply investigate the role of reelin dysfunction as vulnerability factor in ASD, we assessed the behavioral, neurochemical, and brain morphological features of reeler male mice. We recently reported a genotype-dependent deviation in the ultrasonic vocal repertoire and a general delay in motor development of reeler pups. We now report that adult male heterozygous (Het) reeler mice did not show social behavior and communication deficits during male-female social interactions. Wildtype and Het mice showed a typical light/dark locomotor activity profile, with a peak during the central interval of the dark phase. However, when faced with a mild stressful stimulus (a saline injection) only Het mice showed an over response to stress. In addition to the behavioral studies, we conducted high performance liquid chromatography and magnetic resonance imaging and spectroscopy to investigate whether reelin mutation influences brain monoamine and metabolites levels in regions involved in ASD. Low levels of dopamine in cortex and high levels of glutamate and taurine in hippocampus were detected in Het mice, in line with clinical data collected on ASD children. Altogether, our data detected subtle but relevant neurochemical abnormalities in reeler mice supporting this mutant line, particularly male subjects, as a valid experimental model to estimate the contribution played by reelin deficiency in the global ASD neurobehavioral phenotype.

  18. Mapping pathological phenotypes in Reelin mutant mice

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    Caterina eMichetti

    2014-09-01

    Full Text Available Autism Spectrum Disorders (ASD are neurodevelopmental disorders with multifactorial origin characterized by social communication and behavioural perseveration deficits. Several studies showed an association between the reelin gene mutation and increased risk of ASD and a reduced reelin expression in some brain regions of ASD subjects, suggesting a role for reelin deficiency in ASD etiology. Reelin is a large extracellular matrix glycoprotein playing important roles during development of the central nervous system. To deeply investigate the role of reelin dysfunction as vulnerability factor in ASD, we investigated the behavioural, neurochemical and brain morphological features of reeler male mice. We recently reported a genotype-dependent deviation in ultrasonic vocal repertoire and a general delay in motor development in reeler pups. We now report that adult male heterozygous reeler mice did not show social behaviour and communication deficits during male-female social interactions. Wildtype and heterozygous mice also showed a typical light/dark locomotor activity profile, with a peak during the central interval of the dark phase. However, when faced with a mild stressful stimulus (a saline injection only heterozygous mice showed an over response to stress. At the end of the behavioural studies, we conducted high performance liquid chromatography and magnetic resonance imaging and spectroscopy to investigate whether reelin mutation influences brain monoamine and metabolites levels in regions involved in ASD. Low levels of dopamine in cortex and high levels of glutamate and taurine in hippocampus were detected in heterozygous mice, in line with clinical data collected on ASD children. Altogether, our data detected subtle but relevant neurochemical abnormalities in reeler mice supporting this mutant line, particularly male subjects, as a valid experimental model to estimate the contribution played by reelin deficiency in the global ASD

  19. The role of NAG-1/GDF15 in the inhibition of intestinal polyps in APC/Min mice by sulindac.

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    Wang, Xingya; Kingsley, Philip J; Marnett, Larry J; Eling, Thomas E

    2011-01-01

    The antitumor effects of nonsteroidal anti-inflammatory drugs (NSAID) are assumed to be due to the inhibition of COX activity, but COX-independent mechanisms may also play an important role. NSAID-activated gene (NAG-1/GDF15) is induced by NSAIDs and has antitumorigenic activities. To determine the contribution of COX-2 inhibition and NAG-1/GDF15 expression to the prevention of colon carcinogenesis by NSAIDs, we evaluated several sulindac derivatives [des-methyl (DM)-sulindac sulfide and its prodrug DM-sulindac] that do not inhibit COX-2 activity. Sulindac sulfide and DM-sulindac induced the expression of NAG-1/GDF15 in HCT116 cells as determined by quantitative real-time PCR and Western blot. We fed APC/Min mice with 320 ppm of sulindac and doses of DM-sulindac. Only sulindac significantly inhibited tumor formation inAPC/Min mice. To determine the pharmacokinetic properties of sulindac and DM-sulindac in vivo, wild-type C57/B6 mice were fed with sulindac and DM-sulindac at 80, 160, and 320 ppm. High-performance liquid chromatography analysis revealed that the conversion of DM-sulindac to DM-sulindac sulfide (active form) was less efficient than the conversion of sulindac to sulindac sulfide (active form) in the mice. Lower levels of DM-sulindac sulfide accumulated in intestinal and colon tissues in comparison with sulindac sulfide. In addition, NAG-1/GDF15 was induced in the liver of sulindac-fed mice but not in the DM-sulindac-fed mice. Collectively, our results suggest that the tumor-inhibitory effects of sulindac in APC/Min mice may be due to, in part, NAG-1/GDF15 induction in the liver. Our study also suggests that pharmacologic properties should be carefully evaluated when developing drug candidates.

  20. Liver fatty acid-binding protein (L-Fabp) modifies intestinal fatty acid composition and adenoma formation in ApcMin/+ mice.

    Science.gov (United States)

    Dharmarajan, Sekhar; Newberry, Elizabeth P; Montenegro, Grace; Nalbantoglu, Ilke; Davis, Victoria R; Clanahan, Michael J; Blanc, Valerie; Xie, Yan; Luo, Jianyang; Fleshman, James W; Kennedy, Susan; Davidson, Nicholas O

    2013-10-01

    Evidence suggests a relationship between dietary fat intake, obesity, and colorectal cancer, implying a role for fatty acid metabolism in intestinal tumorigenesis that is incompletely understood. Liver fatty acid-binding protein (L-Fabp), a dominant intestinal fatty acid-binding protein, regulates intestinal fatty acid trafficking and metabolism, and L-Fabp deletion attenuates diet-induced obesity. Here, we examined whether changes in intestinal fatty acid metabolism following L-Fabp deletion modify adenoma development in Apc(Min)(/+) mice. Compound L-Fabp(-/-)Apc(Min)(/+) mice were generated and fed a 10% fat diet balanced equally between saturated, monounsaturated, and polyunsaturated fat. L-Fabp(-/-)Apc(Min)(/+) mice displayed significant reductions in adenoma number and total polyp area compared with Apc(Min)(/+)controls, reflecting a significant shift in distribution toward smaller polyps. Adenomas from L-Fabp(-/-)Apc(Min)(/+) mice exhibited reductions in cellular proliferation, high-grade dysplasia, and nuclear β-catenin translocation. Intestinal fatty acid content was increased in L-Fabp(-/-)Apc(Min)(/+) mice, and lipidomic profiling of intestinal mucosa revealed significant shifts to polyunsaturated fatty acid species with reduced saturated fatty acid species. L-Fabp(-/-)Apc(Min)(/+) mice also showed corresponding changes in mRNA expression of enzymes involved in fatty acid elongation and desaturation. Furthermore, adenomas from L-Fabp(-/-)Apc(Min)(/+) mice displayed significant reductions in mRNA abundance of nuclear hormone receptors involved in cellular proliferation and in enzymes involved in lipogenesis. These findings collectively implicate L-Fabp as an important genetic modifier of intestinal tumorigenesis, and identify fatty acid trafficking and metabolic compartmentalization as an important pathway linking dietary fat intake, obesity, and intestinal tumor formation.

  1. Mammary tumorigenesis in APC{sup min/+} mice is enhanced by X-irradiation with a characteristic age dependence

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    Tatsuhiko, Imaoka; Mayumi, Nishimura; Shizuko, Kakinuma; Yoshiya, Shimada [National Institute of Radiological Sciences, Experimental Radiobiology for Children' s Health Research Group, Research, Center for Radiation Protection (Japan); Mieko, Okamoto [Tokyo Metropolitan Institute of Medical Science (Japan)

    2006-07-01

    The ApcM{sup min/+} (Min) mouse is a genetically predisposed model of both intestinal and mammary tumorigenesis. We investigated age-related changes in the susceptibility of mice (before, during and after puberty) to radiation-induced mammary tumorigenesis using this model. Female Min and wild-type mice having the C57BL/6J background were irradiated with 2 Gy of X-rays at 2, 5, 7 and 10 weeks and sacrificed at 18 weeks of age. Min mice irradiated at 7 to 10 weeks of age (after puberty) developed mammary tumors with squamous metaplasia, whereas their wild-type litter-mates did not. Interestingly, irradiation of Min mice at 2 to 5 weeks (before and during puberty, respectively) did not induce mammary tumors but rather cystic nodules with metaplasia. The mammary tumors exhibited increased nuclear beta-catenin protein and loss of the wild-type Apc allele. Our results show that susceptibility to radiation-induced mammary tumorigenesis increases after puberty in Min mice, suggesting that the tumorigenic effect of ionizing radiation targets the lobular-alveolar progenitor cells, which increase in number with age and are controlled by beta-catenin signaling. (author)

  2. Five quantitative trait loci control radiation-induced adenoma multiplicity in Mom1R Apc Min/+ mice.

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    Eiram Elahi

    Full Text Available Ionising radiation is a carcinogen capable of inducing tumours, including colorectal cancer, in both humans and animals. By backcrossing a recombinant line of Apc(Min/+ mice to the inbred BALB/c mouse strain, which is unusually sensitive to radiation-induced tumour development, we obtained panels of 2Gy-irradiated and sham-irradiated N2 Apc(Min/+ mice for genotyping with a genome-wide panel of microsatellites at approximately 15 cM density and phenotyping by counting adenomas in the small intestine. Interval and composite interval mapping along with permutation testing identified five significant susceptibility quantitative trait loci (QTLs responsible for radiation induced tumour multiplicity in the small intestine. These were defined as Mom (Modifier of Min radiation-induced polyposis (Mrip1-5 on chromosome 2 (log of odds, LOD 2.8, p = 0.0003, two regions within chromosome 5 (LOD 5.2, p<0.00001, 6.2, p<0.00001 and two regions within chromosome 16 respectively (LOD 4.1, p = 4x10(-5, 4.8, p<0.00001. Suggestive QTLs were found for sham-irradiated mice on chromosomes 3, 6 and 13 (LOD 1.7, 1.5 and 2.0 respectively; p<0.005. Genes containing BALB/c specific non-synonymous polymorphisms were identified within Mrip regions and prediction programming used to locate potentially functional polymorphisms. Our study locates the QTL regions responsible for increased radiation-induced intestinal tumorigenesis in Apc(Min/+ mice and identifies candidate genes with predicted functional polymorphisms that are involved in spindle checkpoint and chromosomal stability (Bub1b, Casc5, and Bub1, DNA repair (Recc1 and Prkdc or inflammation (Duox2, Itgb2l and Cxcl5. Our study demonstrates use of in silico analysis in candidate gene identification as a way of reducing large-scale backcross breeding programmes.

  3. Diet- and Genetically-induced Obesity Produces Alterations in the Microbiome, Inflammation and Wnt Pathway in the Intestine of Apc+/1638N Mice: Comparisons and Contrasts

    OpenAIRE

    Liu, Wei; Crott, Jimmy W.; Lyu, Lin; Pfalzer, Anna C.; Li, Jinchao; Choi, Sang-Woon; Yang, Yingke; Mason, Joel B.; Liu, Zhenhua

    2016-01-01

    Obesity is an established risk factor for colorectal cancer (CRC). Our previous study indicated that obesity increases activity of the pro-tumorigenic Wnt-signaling. Presently, we sought to further advance our understanding of the mechanisms by which obesity promotes CRC by examining associations between microbiome, inflammation and Wnt-signaling in Apc+/1638N mice whose obesity was induced by one of two modalities, diet- or genetically-induced obesity. Three groups were employed: Apc+/1638NL...

  4. Diet- and Genetically-induced Obesity Produces Alterations in the Microbiome, Inflammation and Wnt Pathway in the Intestine of Apc+/1638N Mice: Comparisons and Contrasts

    OpenAIRE

    Liu, Wei; Crott, Jimmy W; Lyu, Lin; Pfalzer, Anna C.; Li, Jinchao; Choi, Sang-Woon; Yang, Yingke; Mason, Joel B; Liu, Zhenhua

    2016-01-01

    Obesity is an established risk factor for colorectal cancer (CRC). Our previous study indicated that obesity increases activity of the pro-tumorigenic Wnt-signaling. Presently, we sought to further advance our understanding of the mechanisms by which obesity promotes CRC by examining associations between microbiome, inflammation and Wnt-signaling in Apc+/1638N mice whose obesity was induced by one of two modalities, diet- or genetically-induced obesity. Three groups were employed: Apc+/1638NL...

  5. C57BL/KsJ-db/db-ApcMin/+ Mice Exhibit an Increased Incidence of Intestinal Neoplasms

    Directory of Open Access Journals (Sweden)

    Yoshinobu Hirose

    2011-11-01

    Full Text Available The numbers of obese people and diabetic patients are ever increasing. Obesity and diabetes are high-risk conditions for chronic diseases, including certain types of cancer, such as colorectal cancer (CRC. The aim of this study was to develop a novel animal model in order to clarify the pathobiology of CRC development in obese and diabetic patients. We developed an animal model of obesity and colorectal cancer by breeding the C57BL/KsJ-db/db (db/db mouse, an animal model of obesity and type II diabetes, and the C57BL/6J-ApcMin/+ (Min/+ mouse, a model of familial adenomatous polyposis. At 15 weeks of age, the N9 backcross generation of C57BL/KsJ-db/db-ApcMin/+ (db/db-Min/+ mice developed an increased incidence and multiplicity of adenomas in the intestinal tract when compared to the db/m-Min/+ and m/m-Min/+ mice. Blood biochemical profile showed significant increases in insulin (8.3-fold to 11.7-fold, cholesterol (1.2-fold to 1.7-fold, and triglyceride (1.2-fold to 1.3-fold in the db/db-Min/+ mice, when compared to those of the db/m-Min/+ and m/m-Min/+ mice. Increases (1.4-fold to 2.6-fold in RNA levels of insulin-like growth factor (IGF-1, IRF-1R, and IGF-2 were also observed in the db/db-Min/+ mice. These results suggested that the IGFs, as well as hyperlipidemia and hyperinsulinemia, promoted adenoma formation in the db/db-Min/+ mice. Our results thus suggested that the db/db-Min/+ mice should be invaluable for studies on the pathogenesis of CRC in obese and diabetes patients and the therapy and prevention of CRC in these patients.

  6. Tart cherry anthocyanins inhibit tumor development in Apc(Min) mice and reduce proliferation of human colon cancer cells.

    Science.gov (United States)

    Kang, Soo-Young; Seeram, Navindra P; Nair, Muraleedharan G; Bourquin, Leslie D

    2003-05-08

    Anthocyanins, which are bioactive phytochemicals, are widely distributed in plants and especially enriched in tart cherries. Based on previous observations that tart cherry anthocyanins and their respective aglycone, cyanidin, can inhibit cyclooxygenase enzymes, we conducted experiments to test the potential of anthocyanins to inhibit intestinal tumor development in Apc(Min) mice and growth of human colon cancer cell lines. Mice consuming the cherry diet, anthocyanins, or cyanidin had significantly fewer and smaller cecal adenomas than mice consuming the control diet or sulindac. Colonic tumor numbers and volume were not significantly influenced by treatment. Anthocyanins and cyanidin also reduced cell growth of human colon cancer cell lines HT 29 and HCT 116. The IC(50) of anthocyanins and cyanidin was 780 and 63 microM for HT 29 cells, respectively and 285 and 85 microM for HCT 116 cells, respectively. These results suggest that tart cherry anthocyanins and cyanidin may reduce the risk of colon cancer.

  7. Plant stanols induce intestinal tumor formation by up-regulating Wnt and EGFR signaling in Apc Min mice.

    Science.gov (United States)

    Marttinen, Maija; Päivärinta, Essi; Storvik, Markus; Huikko, Laura; Luoma-Halkola, Heli; Piironen, Vieno; Pajari, Anne-Maria; Mutanen, Marja

    2013-01-01

    The rate of APC mutations in the intestine increases in middle-age. At the same period of life, plant sterol and stanol enriched functional foods are introduced to diet to lower blood cholesterol. This study examined the effect of plant stanol enriched diet on intestinal adenoma formation in the Apc(Min) mouse. Apc(Min) mice were fed 0.8% plant stanol diet or control diet for nine weeks. Cholesterol, plant sterols and plant stanols were analyzed from the caecum content and the intestinal mucosa. Levels of β-catenin, cyclin D1, epidermal growth factor receptor (EGFR) and extracellular signal-regulated kinase 1/2 (ERK1/2) were measured from the intestinal mucosa by Western blotting. Gene expression was determined from the intestinal mucosa using Affymetrix and the data were analyzed for enriched categories and pathways. Plant stanols induced adenoma formation in the small intestine, however, the adenoma size was not affected. We saw increased levels of nuclear β-catenin, phosphorylated β-catenin (Ser675 and Ser552), nuclear cyclin D1, total and phosphorylated EGFR and phosphorylated ERK1/2 in the intestinal mucosa after plant stanol feeding. The Affymetrix data demonstrate that several enzymes of cholesterol synthesis pathway were up-regulated, although the cholesterol level in the intestinal mucosa was not altered. We show that plant stanols induce adenoma formation by activating Wnt and EGFR signaling. EGFR signaling seems to have promoted β-catenin phosphorylation and its translocation into the nucleus, where the expression of cyclin D1 was increased. Up-regulated cholesterol synthesis may partly explain the increased EGFR signaling in the plant stanol-fed mice.

  8. Influence of myeloperoxidase on colon tumor occurrence in inflamed versus non-inflamed colons of Apc(Min/+) mice.

    Science.gov (United States)

    Al-Salihi, Mazin; Reichert, Ethan; Fitzpatrick, F A

    2015-12-01

    Control of colorectal cancer needs to be tailored to its etiology. Tumor promotion mechanisms in colitis-associated colon cancer differ somewhat from the mechanisms involved in hereditary and sporadic colorectal cancer. Unlike sporadic or inherited tumors, some experimental models show that colitis-associated colon tumors do not require cyclooxygenase (COX) expression for progression, and non-steroidal anti-inflammatory drugs (NSAIDs) which prevent sporadic or inherited colon cancer do not prevent colitis-associated colon cancer. We report that myeloperoxidase (MPO), an ancestor of the COX isoenzymes, is a determinant of colitis-associated colon tumors in Apc(Min/+) mice. During experimentally induced colitis, inhibition of MPO by resorcinol dampened colon tumor development. Conversely, in the bowels of Apc(Min/+) mice without colitis, resorcinol administration or 'knockout' of MPO gene coincided with a slight, but discernible increase in colon tumor incidence. Acrolein, a by-product of MPO catalysis, formed a covalent adduct with the phosphatase tensin homolog (PTEN) tumor suppressor and enhanced the activity of the Akt kinase proto-oncogene in vitro and in vivo. Thus, MPO may be an important determinant of diet and inflammation on colon cancer risk via its effect on endogenous exposure to oxidants and acrolein. We propose a hypothetical model to explain an apparent dichotomy between colon tumor occurrence and MPO inhibition in inflamed versus non-inflamed colons.

  9. Chronic Trichuris muris infection causes neoplastic change in the intestine and exacerbates tumour formation in APC min/+ mice.

    Directory of Open Access Journals (Sweden)

    Kelly S Hayes

    2017-06-01

    Full Text Available Incidences of infection-related cancers are on the rise in developing countries where the prevalence of intestinal nematode worm infections are also high. Trichuris muris (T. muris is a murine gut-dwelling nematode that is the direct model for human T. trichiura, one of the major soil-transmitted helminth infections of humans. In order to assess whether chronic infection with T. muris does indeed influence the development of cancer hallmarks, both wild type mice and colon cancer model (APC min/+ mice were infected with this parasite. Parasite infection in wild type mice led to the development of neoplastic change similar to that seen in mice that had been treated with the carcinogen azoxymethane. Additionally, both chronic and acute infection in the APCmin/+ mice led to an enhanced tumour development that was distinct to the site of infection suggesting systemic control. By blocking the parasite induced T regulatory response in these mice, the increase in the number of tumours following infection was abrogated. Thus T. muris infection alone causes an increase in gut pathologies that are known to be markers of cancer but also increases the incidence of tumour formation in a colon cancer model. The influence of parasitic worm infection on the development of cancer may therefore be significant.

  10. Chronic Trichuris muris infection causes neoplastic change in the intestine and exacerbates tumour formation in APC min/+ mice.

    Science.gov (United States)

    Hayes, Kelly S; Cliffe, Laura J; Bancroft, Alison J; Forman, Simon P; Thompson, Seona; Booth, Cath; Grencis, Richard K

    2017-06-01

    Incidences of infection-related cancers are on the rise in developing countries where the prevalence of intestinal nematode worm infections are also high. Trichuris muris (T. muris) is a murine gut-dwelling nematode that is the direct model for human T. trichiura, one of the major soil-transmitted helminth infections of humans. In order to assess whether chronic infection with T. muris does indeed influence the development of cancer hallmarks, both wild type mice and colon cancer model (APC min/+) mice were infected with this parasite. Parasite infection in wild type mice led to the development of neoplastic change similar to that seen in mice that had been treated with the carcinogen azoxymethane. Additionally, both chronic and acute infection in the APCmin/+ mice led to an enhanced tumour development that was distinct to the site of infection suggesting systemic control. By blocking the parasite induced T regulatory response in these mice, the increase in the number of tumours following infection was abrogated. Thus T. muris infection alone causes an increase in gut pathologies that are known to be markers of cancer but also increases the incidence of tumour formation in a colon cancer model. The influence of parasitic worm infection on the development of cancer may therefore be significant.

  11. Low and high dose rate heavy ion radiation-induced intestinal and colonic tumorigenesis in APC1638N/+ mice

    Science.gov (United States)

    Suman, Shubhankar; Kumar, Santosh; Moon, Bo-Hyun; Fornace, Albert J.; Datta, Kamal

    2017-05-01

    Ionizing radiation (IR) is a recognized risk factor for colorectal cancer (CRC) and astronauts undertaking long duration space missions are expected to receive IR doses in excess of permissible limits with implications for colorectal carcinogenesis. Exposure to IR in outer space occurs at low doses and dose rates, and energetic heavy ions due to their high linear energy transfer (high-LET) characteristics remain a major concern for CRC risk in astronauts. Previously, we have demonstrated that intestinal tumorigenesis in a mouse model (APC1638N/+) of human colorectal cancer was significantly higher after exposure to high dose rate energetic heavy ions relative to low-LET γ radiation. The purpose of the current study was to compare intestinal tumorigenesis in APC1638N/+ mice after exposure to energetic heavy ions at high (50 cGy/min) and relatively low (0.33 cGy/min) dose rate. Male and female mice (6-8 weeks old) were exposed to either 10 or 50 cGy of 28Si (energy: 300 MeV/n; LET: 70 keV/μm) or 56Fe (energy: 1000 MeV/n; LET: 148 keV/μm) ions at NASA Space Radiation Laboratory in Brookhaven National Laboratory. Mice (n = 20 mice/group) were euthanized and intestinal and colon tumor frequency and size were counted 150 days after radiation exposure. Intestinal tumorigenesis in male mice exposed to 56Fe was similar for high and low dose rate exposures. Although male mice showed a decreasing trend at low dose rate relative to high dose rate exposures, the differences in tumor frequency between the two types of exposures were not statistically significant after 28Si radiation. In female mice, intestinal tumor frequency was similar for both radiation type and dose rates tested. In both male and female mice intestinal tumor size was not different after high and low dose rate radiation exposures. Colon tumor frequency in male and female mice after high and low dose rate energetic heavy ions was also not significantly different. In conclusion, intestinal and colonic tumor

  12. Low and high dose rate heavy ion radiation-induced intestinal and colonic tumorigenesis in APC(1638N/+) mice.

    Science.gov (United States)

    Suman, Shubhankar; Kumar, Santosh; Moon, Bo-Hyun; Fornace, Albert J; Datta, Kamal

    2017-05-01

    Ionizing radiation (IR) is a recognized risk factor for colorectal cancer (CRC) and astronauts undertaking long duration space missions are expected to receive IR doses in excess of permissible limits with implications for colorectal carcinogenesis. Exposure to IR in outer space occurs at low doses and dose rates, and energetic heavy ions due to their high linear energy transfer (high-LET) characteristics remain a major concern for CRC risk in astronauts. Previously, we have demonstrated that intestinal tumorigenesis in a mouse model (APC(1638N/+)) of human colorectal cancer was significantly higher after exposure to high dose rate energetic heavy ions relative to low-LET γ radiation. The purpose of the current study was to compare intestinal tumorigenesis in APC(1638N/+) mice after exposure to energetic heavy ions at high (50cGy/min) and relatively low (0.33cGy/min) dose rate. Male and female mice (6-8 weeks old) were exposed to either 10 or 50cGy of (28)Si (energy: 300MeV/n; LET: 70keV/μm) or (56)Fe (energy: 1000MeV/n; LET: 148keV/μm) ions at NASA Space Radiation Laboratory in Brookhaven National Laboratory. Mice (n=20 mice/group) were euthanized and intestinal and colon tumor frequency and size were counted 150days after radiation exposure. Intestinal tumorigenesis in male mice exposed to (56)Fe was similar for high and low dose rate exposures. Although male mice showed a decreasing trend at low dose rate relative to high dose rate exposures, the differences in tumor frequency between the two types of exposures were not statistically significant after (28)Si radiation. In female mice, intestinal tumor frequency was similar for both radiation type and dose rates tested. In both male and female mice intestinal tumor size was not different after high and low dose rate radiation exposures. Colon tumor frequency in male and female mice after high and low dose rate energetic heavy ions was also not significantly different. In conclusion, intestinal and colonic

  13. Maternal Antibiotic Treatment Protects Offspring from Diabetes Development in Nonobese Diabetic Mice by Generation of Tolerogenic APCs.

    Science.gov (United States)

    Hu, Youjia; Peng, Jian; Tai, Ningwen; Hu, Changyun; Zhang, Xiaojun; Wong, F Susan; Wen, Li

    2015-11-01

    Type 1 diabetes (T1D) is a T cell-mediated autoimmune disease that involves the slow, progressive destruction of islet β cells and loss of insulin production, as a result of interaction with environmental factors, in genetically susceptible individuals. The gut microbiome is established very early in life. Commensal microbiota establish mutualism with the host and form an important part of the environment to which individuals are exposed in the gut, providing nutrients and shaping immune responses. In this study, we studied the impact of targeting most Gram-negative bacteria in the gut of NOD mice at different time points in their life, using a combination of three antibiotics--neomycin, polymyxin B, and streptomycin--on diabetes development. We found that the prenatal period is a critical time for shaping the immune tolerance in the progeny, influencing development of autoimmune diabetes. Prenatal neomycin, polymyxin B, and streptomycin treatment protected NOD mice from diabetes development through alterations in the gut microbiota, as well as induction of tolerogenic APCs, which led to reduced activation of diabetogenic CD8 T cells. Most importantly, we found that the protective effect was age dependent, and the most profound protection was found when the mice were treated before birth. This indicates the importance of the prenatal environment and early exposure to commensal bacteria in shaping the host immune system and health.

  14. Polyyne-Enriched Extract from Oplopanax elatus Significantly Ameliorates the Progression of Colon Carcinogenesis in ApcMin/+ Mice

    Directory of Open Access Journals (Sweden)

    Xin Qiao

    2017-09-01

    Full Text Available Colorectal cancer (CRC is the third most common cancer in the world. Oplopanax elatus is widely used in traditional medicine. However, little is known about its pharmacological effects and bioactive compounds. We evaluated the effects of the polyyne-enriched extract from O. elatus (PEO on the progression of colon carcinogenesis in ApcMin/+ mice. In addition, these effects were also investigated in HCT116 and SW480 cells. After PEO oral administration (0.2% diet for 12 weeks, PEO significantly improved body weight changes and reduced the tumor burden and tumor multiplicity compared with the untreated mice. Meanwhile, western blot and immunohistochemistry results showed PEO significantly reduced the expression of β-catenin and cyclinD1 in both small intestine and the colon tissues compared with the untreated mice. In addition, PEO treatment significant decreased the cell viability in both HCT116 and SW480 cell lines. It also decreased the levels of β-catenin, cyclinD1, c-myc and p-GSK-3β in HCT116 and SW480 cells at 25 μM. These results indicate that PEO may have potential value in prevention of colon cancer by down-regulating Wnt-related protein.

  15. Profiling of volatile compounds in APC(Min/+) mice blood by dynamic headspace extraction and gas chromatography/mass spectrometry.

    Science.gov (United States)

    Kakuta, Shoji; Nishiumi, Shin; Yoshida, Masaru; Fukusaki, Eiichiro; Bamba, Takeshi

    2015-10-15

    Various volatile compounds as well as hydrophilic compounds exist in the blood. For example, 2-alkenals, 4-hydroxy-2-alkenals, and ketoaldehydes have been reported as oxidized lipid-derived volatiles in blood. These specific volatiles have been associated with diseases; however, multi-volatile analyses have not been performed. In this study, volatile profiling of APC(Min/+) mouse plasma by dynamic headspace extraction was performed for multi-volatile analysis. In total, 19 volatiles were detected in the plasma of mice, based on information regarding oxidized lipid-derived volatile compounds, and eight of these compounds differed significantly between normal and diseased mice. 2-Methyl-2-butanol and benzyl alcohol were previously unreported in blood samples. Furthermore, 3,5,5-trimethyl-2(5H)-furanone was only detected in normal mice. 5-Methyl-3-hexanone and benzaldehyde have been detected in subjects with gastrointestinal diseases and lung cancer, respectively. Therefore, volatile profiling can be used to detect differences between samples and to identify compounds associated with diseases.

  16. Sensorimotor learning in Dab1(scm) (scrambler) mutant mice.

    Science.gov (United States)

    Lalonde, R; Strazielle, C

    2011-04-15

    Homozygous Dab1(scm) mouse mutants with cell ectopias in cerebellar cortex and neocortex were compared with non-ataxic controls on two tests of motor coordination: rotorod and grid climbing. Even at the minimal speed of 4 rpm and unlike controls, none of the Dab1(scm) mutants reached criterion on the constant speed rotorod. In contrast, Dab1(scm) mutants improved their performances on the vertical grid over the course of the same number of trials. Thus, despite massive cerebellar degeneration, sensorimotor learning for equilibrium is still possible, indicating the potential usefulness of the grid-climbing test in determining residual functions in mice with massive cerebellar damage.

  17. A targeted constitutive mutation in the APC tumor suppressor gene underlies mammary but not intestinal tumorigenesis.

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    Claudia Gaspar

    2009-07-01

    Full Text Available Germline mutations in the adenomatous polyposis coli (APC gene are responsible for familial adenomatous polyposis (FAP, an autosomal dominant hereditary predisposition to the development of multiple colorectal adenomas and of a broad spectrum of extra-intestinal tumors. Moreover, somatic APC mutations play a rate-limiting and initiating role in the majority of sporadic colorectal cancers. Notwithstanding its multifunctional nature, the main tumor suppressing activity of the APC gene resides in its ability to regulate Wnt/beta-catenin signaling. Notably, genotype-phenotype correlations have been established at the APC gene between the length and stability of the truncated proteins encoded by different mutant alleles, the corresponding levels of Wnt/beta-catenin signaling activity they encode for, and the incidence and distribution of intestinal and extra-intestinal tumors. Here, we report a novel mouse model, Apc1572T, obtained by targeting a truncated mutation at codon 1572 in the endogenous Apc gene. This hypomorphic mutant allele results in intermediate levels of Wnt/beta-catenin signaling activation when compared with other Apc mutations associated with multifocal intestinal tumors. Notwithstanding the constitutive nature of the mutation, Apc(+/1572T mice have no predisposition to intestinal cancer but develop multifocal mammary adenocarcinomas and subsequent pulmonary metastases in both genders. The histology of the Apc1572T primary mammary tumours is highly heterogeneous with luminal, myoepithelial, and squamous lineages and is reminiscent of metaplastic carcinoma of the breast in humans. The striking phenotype of Apc(+/1572T mice suggests that specific dosages of Wnt/beta-catenin signaling activity differentially affect tissue homeostasis and initiate tumorigenesis in an organ-specific fashion.

  18. Nuclear APC

    OpenAIRE

    Neufeld, Kristi L.

    2009-01-01

    Mutational inactivation of the tumor suppressor gene APC (Adenomatous polyposis coli) is thought to be an initiating step in the progression of the vast majority of colorectal cancers. Attempts to understand APC function have revealed more than a dozen binding partners as well as several subcellular localizations including at cell-cell junctions, associated with microtubules at the leading edge of migrating cells, at the apical membrane, in the cytoplasm and in the nucleus. The present chapte...

  19. Maintenance of adenomatous polyposis coli (APC)-mutant colorectal cancer is dependent on Wnt/beta-catenin signaling.

    Science.gov (United States)

    Scholer-Dahirel, Alix; Schlabach, Michael R; Loo, Alice; Bagdasarian, Linda; Meyer, Ronald; Guo, Ribo; Woolfenden, Steve; Yu, Kristine K; Markovits, Judit; Killary, Karen; Sonkin, Dmitry; Yao, Yung-Mae; Warmuth, Markus; Sellers, William R; Schlegel, Robert; Stegmeier, Frank; Mosher, Rebecca E; McLaughlin, Margaret E

    2011-10-11

    Persistent expression of certain oncogenes is required for tumor maintenance. This phenotype is referred to as oncogene addiction and has been clinically validated by anticancer therapies that specifically inhibit oncoproteins such as BCR-ABL, c-Kit, HER2, PDGFR, and EGFR. Identifying additional genes that are required for tumor maintenance may lead to new targets for anticancer drugs. Although the role of aberrant Wnt pathway activation in the initiation of colorectal cancer has been clearly established, it remains unclear whether sustained Wnt pathway activation is required for colorectal tumor maintenance. To address this question, we used inducible β-catenin shRNAs to temporally control Wnt pathway activation in vivo. Here, we show that active Wnt/β-catenin signaling is required for maintenance of colorectal tumor xenografts harboring APC mutations. Reduced tumor growth upon β-catenin inhibition was due to cell cycle arrest and differentiation. Upon reactivation of the Wnt/β-catenin pathway colorectal cancer cells resumed proliferation and reacquired a crypt progenitor phenotype. In human colonic adenocarcinomas, high levels of nuclear β-catenin correlated with crypt progenitor but not differentiation markers, suggesting that the Wnt/β-catenin pathway may also control colorectal tumor cell fate during the maintenance phase of tumors in patients. These results support efforts to treat human colorectal cancer by pharmacological inhibition of the Wnt/β-catenin pathway.

  20. Obesity promotes PhIP-induced small intestinal carcinogenesis in hCYP1A-db/db mice: involvement of mutations and DNA hypermethylation of Apc.

    Science.gov (United States)

    Wang, Hong; Liu, Anna; Kuo, Yingyi; Chi, Eric; Yang, Xu; Zhang, Lanjing; Yang, Chung S

    2016-07-01

    Obesity is associated with an increased risk of cancer. To study the promotion of dietary carcinogen-induced gastrointestinal cancer by obesity, we employed 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) to induce intestinal tumorigenesis in CYP1A-humanized (hCYP1A) mice, in which mouse Cyp1a1/1a2 was replaced with human CYP1A1/1A2 Obesity was introduced in hCYP1A mice by breeding with Lepr(db/+) mice to establish the genetically induced obese hCYP1A-Lepr(db/db) mice or by feeding hCYP1A mice a high-fat diet. PhIP induced the formation of small intestinal tumors at the ages of weeks 28-40 in obese hCYP1A mice, but not in lean hCYP1A mice. No tumors were found in colon and other gastrointestinal organs in the lean or obese mice. Using immunohistochemistry (IHC), we found strong positive staining of NF-κB p65, pSTAT3 and COX2 as well as elevated levels of nuclear β-catenin (Ctnnb1) in small intestinal tumors, but not in normal tissues. By sequencing Apc and Ctnnb1 genes, we found that most PhIP-induced small intestinal tumors in obese mice carried only a single heterozygous mutation in Apc By bisulfite-sequencing of CpG islands of Apc, we found DNA hypermethylation in a CpG cluster located in its transcription initiation site, which most likely caused the inactivation of the wild-type Apc allele. Our findings demonstrate that PhIP-induced small intestinal carcinogenesis in hCYP1A-db/db mice is promoted by obesity and involves Apc mutation and inactivation by DNA hypermethylation. This experimental result is consistent with the association of obesity and the increased incidence of small intestinal cancer in humans in recent decades. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Diet- and Genetically-Induced Obesity Differentially Affect the Fecal Microbiome and Metabolome in Apc1638N Mice.

    Directory of Open Access Journals (Sweden)

    Anna C Pfalzer

    Full Text Available Obesity is a risk factor for colorectal cancer (CRC, and alterations in the colonic microbiome and metabolome may be mechanistically involved in this relationship. The relative contribution of diet and obesity per se are unclear. We compared the effect of diet- and genetically-induced obesity on the intestinal microbiome and metabolome in a mouse model of CRC. Apc1638N mice were made obese by either high fat (HF feeding or the presence of the Leprdb/db (DbDb mutation. Intestinal tumors were quantified and stool microbiome and metabolome were profiled. Genetic obesity, and to a lesser extent HF feeding, promoted intestinal tumorigenesis. Each induced distinct microbial patterns: taxa enriched in HF were mostly Firmicutes (6 of 8 while those enriched in DbDb were split between Firmicutes (7 of 12 and Proteobacteria (5 of 12. Parabecteroides distasonis was lower in tumor-bearing mice and its abundance was inversely associated with colonic Il1b production (p<0.05. HF and genetic obesity altered the abundance of 49 and 40 fecal metabolites respectively, with 5 in common. Of these 5, adenosine was also lower in obese and in tumor-bearing mice (p<0.05 and its concentration was inversely associated with colonic Il1b and Tnf production (p<0.05. HF and genetic obesity differentially alter the intestinal microbiome and metabolome. A depletion of adenosine and P.distasonis in tumor-bearing mice could play a mechanistic role in tumor formation. Adenosine and P. distasonis have previously been shown to be anti-inflammatory in the colon and we postulate their reduction could promote tumorigenesis by de-repressing inflammation.

  2. Abnormal grooming activity in Dab1(scm) (scrambler) mutant mice.

    Science.gov (United States)

    Strazielle, C; Lefevre, A; Jacquelin, C; Lalonde, R

    2012-07-15

    Dab1(scm) mutant mice, characterized by cell ectopias and degeneration in cerebellum, hippocampus, and neocortex, were compared to non-ataxic controls for different facets of grooming caused by brief water immersions, as well as some non-grooming behaviors. Dab1(scm) mutants were strongly affected in their quantitative functional parameters, exhibiting higher starting latencies before grooming relative to non-ataxic littermates of the A/A strain, fewer grooming bouts, and grooming components of shorter duration, with an unequal regional distribution targeting almost totally the rostral part (head washing and forelimb licking) of the animal. Only bouts of a single grooming element were preserved. The cephalocaudal order of grooming elements appeared less disorganized, mutant and control mice initiating the grooming with head washing and forelimb licking prior to licking posterior parts. However, mutants differed from controls in that all their bouts were incomplete but uninterrupted, although intergroup difference for percentage of the incorrect transitions was not significant. In contrast to grooming, Dab1(scm) mice ambulated for a longer time. During walking episodes, they exhibited more body scratching than controls, possibly to compensate for the lack of licking different body parts. In conjunction with studies with other ataxic mice, these results indicate that the cerebellar cortex affects grooming activity and is consequently involved in executing various components, but not in its sequential organization, which requires other brain regions such as cerebral cortices or basal ganglia.

  3. Helicobacter pylori arginase mutant colonizes arginase Ⅱ knockout mice

    Institute of Scientific and Technical Information of China (English)

    Songhee H Kim; Melanie L Langford; Jean-Luc Boucher; Traci L Testerman; David J McGee

    2011-01-01

    AIM: To investigate the role of host and bacterial argi-nases in the colonization of mice by Helicobacter pylori (H. Pylori).METHODS: H. Pylori produces a very powerful urease that hydrolyzes urea to carbon dioxide and ammonium, which neutralizes acid. Urease is absolutely essential to H. Pylori pathogenesis; therefore, the urea substrate must be in ample supply for urease to work efficiently. The urea substrate is most likely provided by arginase activity, which hydrolyzes L-arginine to L-ornithine and urea. Previous work has demonstrated that H. Pylori arginase is surprisingly not required for colonization of wild-type mice. Hence, another in vivo source of the critical urea substrate must exist. We hypothesized that the urea source was provided by host arginase Ⅱ, since this enzyme is expressed in the stomach, and H. Pylori has previously been shown to induce the expres-sion of murine gastric arginase Ⅱ. To test this hypoth-esis, wild-type and arginase (rocF) mutant H. Pylori strain SS1 were inoculated into arginase Ⅱ knockout mice. RESULTS: Surprisingly, both the wild-type and rocF mutant bacteria still colonized arginase Ⅱ knock-out mice. Moreover, feeding arginase Ⅱ knockout mice the host arginase inhibitor S-(2-boronoethyl)-L-cysteine (BEC), while inhibiting > 50% of the host arginase Ⅰactivity in several tissues, did not block the ability of the rocF mutant H. Pylori to colonize. In con-trast, BEC poorly inhibited H. Pylori arginase activity. CONCLUSION: The in vivo source for the essential urea utilized by H. Pylori urease is neither bacterial arginase nor host arginase Ⅱ; instead, either residual host arginase Ⅰor agmatinase is probably responsible.

  4. Genes and Alcohol Consumption: Studies with Mutant Mice

    Science.gov (United States)

    Mayfield, Jody; Arends, Michael A.; Harris, R. Adron; Blednov, Yuri A.

    2017-01-01

    In this chapter, we review the effects of global null mutant and overexpressing transgenic mouse lines on voluntary self-administration of alcohol. We examine approximately 200 publications pertaining to the effects of 155 mouse genes on alcohol consumption in different drinking models. The targeted genes vary in function and include neurotransmitter, ion channel, neuroimmune, and neuropeptide signaling systems. The alcohol self-administration models include operant conditioning, two- and four-bottle choice continuous and intermittent access, drinking in the dark limited access, chronic intermittent ethanol, and scheduled high alcohol consumption tests. Comparisons of different drinking models using the same mutant mice are potentially the most informative, and we will highlight those examples. More mutants have been tested for continuous two-bottle choice consumption than any other test; of the 137 mouse genes examined using this model, 97 (72%) altered drinking in at least one sex. Overall, the effects of genetic manipulations on alcohol drinking often depend on the sex of the mice, alcohol concentration and time of access, genetic background, as well as the drinking test. PMID:27055617

  5. Genes and Alcohol Consumption: Studies with Mutant Mice.

    Science.gov (United States)

    Mayfield, J; Arends, M A; Harris, R A; Blednov, Y A

    2016-01-01

    In this chapter, we review the effects of global null mutant and overexpressing transgenic mouse lines on voluntary self-administration of alcohol. We examine approximately 200 publications pertaining to the effects of 155 mouse genes on alcohol consumption in different drinking models. The targeted genes vary in function and include neurotransmitter, ion channel, neuroimmune, and neuropeptide signaling systems. The alcohol self-administration models include operant conditioning, two- and four-bottle choice continuous and intermittent access, drinking in the dark limited access, chronic intermittent ethanol, and scheduled high alcohol consumption tests. Comparisons of different drinking models using the same mutant mice are potentially the most informative, and we will highlight those examples. More mutants have been tested for continuous two-bottle choice consumption than any other test; of the 137 mouse genes examined using this model, 97 (72%) altered drinking in at least one sex. Overall, the effects of genetic manipulations on alcohol drinking often depend on the sex of the mice, alcohol concentration and time of access, genetic background, as well as the drinking test.

  6. Boc modifies the holoprosencephaly spectrum of Cdo mutant mice

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    2011-05-01

    Holoprosencephaly (HPE is caused by a failure to form the midline of the forebrain and/or midface. It is one of the most common human birth defects, but clinical expression is extremely variable. HPE is associated with mutations in the sonic hedgehog (SHH pathway. Mice lacking the Shh pathway regulator Cdo (also called Cdon display HPE with strain-dependent penetrance and expressivity, implicating silent modifier genes as one cause of the variability. However, the identities of potential HPE modifiers of this type are unknown. We report here that whereas mice lacking the Cdo paralog Boc do not have HPE, Cdo;Boc double mutants on a largely Cdo-resistant genetic background have lobar HPE with strong craniofacial anomalies and defects in Shh target gene expression in the developing forebrain. Boc is therefore a silent HPE modifier gene in mice. Furthermore, Cdo and Boc have specific, selective roles in Shh signaling in mammals, because Cdo;Boc double-mutant mice do not display the most severe HPE phenotype seen in Shh-null mice, nor do they have major defects in digit patterning or development of vertebrae, which are also Shh-dependent processes. This is in contrast to reported observations in Drosophila, where genetic removal of the Cdo and Boc orthologs Ihog and Boi results in a complete loss of response to the hedgehog ligand. Therefore, there is evolutionary divergence between mammals and insects in the requirement of the hedgehog pathway for Cdo/Ihog family members, with mammalian development involving additional factors and/or distinct mechanisms at this level of pathway regulation.

  7. Executionary pathway for apoptosis: lessons from mutant mice

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Apoptosis or programmed cell death (PCD) is an evolutionarily conserved cellular process that is essential for normal development and homeostasis of multicellular organisms. Defects in the apoptosis signaling result in many diseases including autoimmune diseases and cancer. The apoptosis signaling pathway was first described genetically in the nematode Caenorhabditis elegans which serves as a framework for the more complex apop totic pathways that exist in mammals. In this review, we will discuss the apoptotic pathways that are emerging in mammals as elucidated by studies of gene-targeted mutant mice.

  8. Executionary pathway for apoptosis:lessons from mutant mice

    Institute of Scientific and Technical Information of China (English)

    WOOMINNA; RAZQALLAHHAKEM; 等

    2000-01-01

    Apoptosis or programmed cell death(PCD) is an evolutionarily conserved cellular process that is essential for normal development and homeostasis of multicellular organisms.Defects in the apoptosis signaling result in many diseases including autoimmune diseases and cancer.The apoptosis signaling pathway was first described genetically in the nematode Caenorhabditis elegans which serves as a framework for the more complex apoptotic pathways that exist in mammals.In this review,we will discuss the apoptotic pathways that are emerging in mammals as elucidated by studies of gene-targeted mutant mice.

  9. Triterpenoid herbal saponins enhance beneficial bacteria, decrease sulfate-reducing bacteria, modulate inflammatory intestinal microenvironment and exert cancer preventive effects in ApcMin/+ mice

    Science.gov (United States)

    Chen, Lei; Brar, Manreetpal S.; Leung, Frederick C. C.; Hsiao, W. L. Wendy

    2016-01-01

    Saponins derived from medicinal plants have raised considerable interest for their preventive roles in various diseases. Here, we investigated the impacts of triterpenoid saponins isolated from Gynostemma pentaphyllum (GpS) on gut microbiome, mucosal environment, and the preventive effect on tumor growth. Six-week old ApcMin/+ mice and their wild-type littermates were fed either with vehicle or GpS daily for the duration of 8 weeks. The fecal microbiome was analyzed by enterobacterial repetitive intergenic consensus (ERIC)-PCR and 16S rRNA gene pyrosequencing. Study showed that GpS treatment significantly reduced the number of intestinal polyps in a preventive mode. More importantly, GpS feeding strikingly reduced the sulfate-reducing bacteria lineage, which are known to produce hydrogen sulfide and contribute to damage the intestinal epithelium or even promote cancer progression. Meanwhile, GpS also boosted the beneficial microbes. In the gut barrier of the ApcMin/+ mice, GpS treatment increased Paneth and goblet cells, up-regulated E-cadherin and down-regulated N-cadherin. In addition, GpS decreased the pro-oncogenic β-catenin, p-Src and the p-STAT3. Furthermore, GpS might also improve the inflamed gut epithelium of the ApcMin/+ mice by upregulating the anti-inflammatory cytokine IL-4, while downregulating pro-inflammatory cytokines TNF-β, IL-1β and IL-18. Intriguingly, GpS markedly stimulated M2 and suppressed M1 macrophage markers, indicating that GpS altered mucosal cytokine profile in favor of the M1 to M2 macrophages switching, facilitating intestinal tissue repair. In conclusion, GpS might reverse the host's inflammatory phenotype by increasing beneficial bacteria, decreasing sulfate-reducing bacteria, and alleviating intestinal inflammatory gut environment, which might contribute to its cancer preventive effects. PMID:27121311

  10. Fibersol-2 induces apoptosis of Apc-deficient colorectal Cancer (SW480) cells and decreases polyp formation in Apc MIN mice.

    Science.gov (United States)

    Sancho, Sara Cuesta; Olson, Susan Losee; Young So, Eui; Shimomura, Kazuhiro; Ouchi, Toru; Preuss, Fabian

    2016-06-02

    The consumption of dietary fibers has been implicated with a lowered risk of human colorectal cancer. Proposed mechanisms involve alterations in the stool consistency, transit time, and formation of short-chain fatty acid by dietary fiber fermentation, and the reorganization of gut microbiota. Here we show that Fibersol-2, a digest-resistant maltodextrin, not only inhibits proliferation of colorectal SW480 cancer cell lines by increasing reactive oxygen species (ROS), but decreases the numbers of the adenoma count in Multiple Intestinal Neoplasia (MIN) mice carrying a mutation in the Adenomatous Polyposis Coli gene by 84 d of age. These observations provide direct evidence that Fibersol-2 intrinsically contains anti-cancer activity, independent of the intestinal metabolism and any potential interactions with the microbiota.

  11. Inhibition of intestinal adenoma formation in APC(Min/+ mice by Riccardin D, a natural product derived from liverwort plant Dumortiera hirsuta.

    Directory of Open Access Journals (Sweden)

    Hui-Ping Liu

    Full Text Available BACKGROUND: Mutation of tumor suppressor gene, adenomatous polyposis coli (APC, is the primary molecular event in the development of most intestinal carcinomas. Animal model with APC gene mutation is an effective tool for study of preventive approaches against intestinal carcinomas. We aimed to evaluate the effect of Riccardin D, a macrocyclic bisbibenzyl compound, as a chemopreventive agent against intestinal adenoma formation in APC(Min/+ mice. METHODS: APC(Min/+ mice were given Riccardin D by p.o. gavage for 7 weeks. Mice were sacrificed, and the number, size and histopathology of intestinal polyps were examined under a microscope. We performed immunohistochemical staining, western blotting, reverse transcriptase-polymerase chain reaction (RT-PCR and enzyme-linked immunosorbent assay (ELISA in intestinal polyps to investigate the mechanism of chemopreventive effect of Riccardin D. RESULTS: Riccardin D treatment resulted in a significant inhibition of intestinal adenoma formation, showing a reduction of polyp number by 41.7%, 31.1% and 44.4%, respectively, in proximal, middle and distal portions of small intestine. The activity of Riccardin D against polyp formation was more profound in colon, wherein Riccardin D decreased polyp number by 79.3%. Size distribution analysis revealed a significant reduction in large-size polyps (2-3 mm by 40.0%, 42.5% and 33.3%, respectively, in proximal, middle and distal portions of small intestine, and 77.8% in colon. Histopathological analysis of the intestinal polyps revealed mostly hyperplastic morphology without obvious dysplasia in Riccardin D-treated mice. Molecular analyses of the polyps suggested that the inhibitory effect of Riccardin D on intestinal adenoma formation was associated with its abilities of reduction in cell proliferation, induction of apoptosis, antiangiogenesis, inhibition of the Wnt signaling pathway and suppression of inflammatory mediators in polyps. CONCLUSIONS: Our results

  12. Post-translational glycoprotein modifications regulate colon cancer stem cells and colon adenoma progression in Apc(min/+) mice through altered Wnt receptor signaling.

    Science.gov (United States)

    Guo, Huabei; Nagy, Tamas; Pierce, Michael

    2014-11-01

    Deletion of GnT-V (MGAT5), which synthesizes N-glycans with β(1,6)-branched glycans, reduced the compartment of cancer stem cells (CSC) in the her-2 mouse model of breast cancer, leading to delay of tumor onset. Because GnT-V levels are also commonly up-regulated in colon cancer, we investigated their regulation of colon CSC and adenoma development. Anchorage-independent cell growth and tumor formation induced by injection of colon tumor cells into NOD/SCID mice were positively associated with GnT-V levels, indicating regulation of proliferation and tumorigenicity. Using Apc(min/+) mice with different GnT-V backgrounds, knock-out of GnT-V had no significant effect on the number of adenoma/mouse, but adenoma size was significantly reduced and accompanied increased survival of Apc(min/+) mice with GnT-V deletion (p cells, we found that FZD-7 receptors expressed N-linked β(1,6) branching, indicating that FZD-7 can be modified by GnT-V. The aberrant Wnt signaling observed after modulating GnT-V levels is likely to result from altered N-linked β(1,6) branching on FZD-7, thereby affecting Wnt signaling, the compartment of CSC, and tumor progression.

  13. Effect of maternal and post weaning folate supply on gene-specific DNA methylation in the small intestine of weaning and adult Apc+/Min and wild type mice.

    Directory of Open Access Journals (Sweden)

    Jill Ann Mckay

    2011-05-01

    Full Text Available Increasing evidence supports the developmental origins of adult health and disease hypothesis which argues for a causal relationship between adverse early life nutrition and increased disease risk in adulthood. Modulation of epigenetic marks, e.g. DNA methylation and consequential altered gene expression, has been proposed as a mechanism mediating these effects. Via its role as a methyl donor, dietary folate supply may influence DNA methylation. As aberrant methylation is an early event in colorectal cancer (CRC pathogenesis, we hypothesised low maternal and/or post-weaning folate intake may influence methylation of genes involved in CRC development. We investigated the effects of maternal folate depletion during pregnancy and lactation on selected gene methylation in the small intestine (SI of wild type (WT and Apc+/Min mice at weaning and as adults. We also investigated the effects of folate depletion post-weaning on gene methylation in adult mice. Female C57Bl6/J mice were fed low or normal folate diets from mating with Apc+/Min males to the end of lactation. A sub set of offspring were killed at weaning. Remaining offspring were weaned on to low or normal folate diets, resulting in 4 treatment groups of Apc+/Min and WT mice. p53 was more methylated in weaning and adult WT compared with Apc+/Min mice (p>0.001. Igf2 and Apc were hypermethylated in adult Apc+/Mi n compared with WT mice (p=0.004 & p=0.012 respectively. Low maternal folate reduced p53 methylation in adults (p=0.04. Low post-weaning folate increased Apc methylation in Apc+/Min mice only (p=0.008 for interaction. These observations demonstrate that folate depletion in early life can alter epigenetic marks in a gene specific manner. Also, the differential effects of altered folate supply on DNA methylation in WT and Apc+/Min mice suggest that genotype may modulate epigenetic responses to environmental cues and may have implications for the development of personalised nutrition.

  14. Protein kinase A antagonist inhibits β-catenin nuclear translocation, c-Myc and COX-2 expression and tumor promotion in ApcMin/+ mice

    Directory of Open Access Journals (Sweden)

    Brudvik Kristoffer W

    2011-12-01

    Full Text Available Abstract Background The adenomatous polyposis coli (APC protein is part of the destruction complex controlling proteosomal degradation of β-catenin and limiting its nuclear translocation, which is thought to play a gate-keeping role in colorectal cancer. The destruction complex is inhibited by Wnt-Frz and prostaglandin E2 (PGE2 - PI-3 kinase pathways. Recent reports show that PGE2-induced phosphorylation of β-catenin by protein kinase A (PKA increases nuclear translocation indicating two mechanisms of action of PGE2 on β-catenin homeostasis. Findings Treatment of ApcMin/+ mice that spontaneously develop intestinal adenomas with a PKA antagonist (Rp-8-Br-cAMPS selectively targeting only the latter pathway reduced tumor load, but not the number of adenomas. Immunohistochemical characterization of intestines from treated and control animals revealed that expression of β-catenin, β-catenin nuclear translocation and expression of the β-catenin target genes c-Myc and COX-2 were significantly down-regulated upon Rp-8-Br-cAMPS treatment. Parallel experiments in a human colon cancer cell line (HCT116 revealed that Rp-8-Br-cAMPS blocked PGE2-induced β-catenin phosphorylation and c-Myc upregulation. Conclusion Based on our findings we suggest that PGE2 act through PKA to promote β-catenin nuclear translocation and tumor development in ApcMin/+ mice in vivo, indicating that the direct regulatory effect of PKA on β-catenin nuclear translocation is operative in intestinal cancer.

  15. Impaired exercise tolerance and skeletal muscle myopathy in sulfonylurea receptor-2 mutant mice

    Science.gov (United States)

    Stoller, Douglas; Pytel, Peter; Katz, Sophie; Earley, Judy U.; Collins, Keith; Metcalfe, Jamie; Lang, Roberto M.

    2009-01-01

    By sensing intracellular energy levels, ATP-sensitive potassium (KATP) channels help regulate vascular tone, glucose metabolism, and cardioprotection. SUR2 mutant mice lack full-length KATP channels in striated and smooth muscle and display a complex phenotype of hypertension and coronary vasospasm. SUR2 mutant mice also display baseline cardioprotection and can withstand acute sympathetic stress better than normal mice. We now studied response to a form of chronic stress, namely that induced by 4 wk of daily exercise on SUR2 mutant mice. Control mice increased exercise capacity by 400% over the training period, while SUR2 mutant mice showed little increase in exercise capacity. Unexercised SUR2 mutant showed necrotic and regenerating fibers in multiple muscle skeletal muscles, including quadriceps, tibialis anterior, and diaphragm muscles. Unlike exercised control animals, SUR2 mutant mice did not lose weight, presumably due to less overall exertion. Unexercised SUR2 mutant mice showed a trend of mildly reduced cardiac function, measured by fractional shortening, (46 ± 4% vs. 57 ± 7% for SUR2 mutant and control, respectively), and this decrease was not exacerbated by chronic exercise exposure. Despite an improved response to acute sympathetic stress and baseline cardioprotection, exercise intolerance results from lack of SUR2 KATP channels in mice. PMID:19675276

  16. Induction of lytic pathways in T cell clones derived from wild-type or protein tyrosine kinase Fyn mutant mice.

    Science.gov (United States)

    Lancki, D W; Fields, P; Qian, D; Fitch, F W

    1995-08-01

    The OVA-reactive CD4+ Th1 clones and alloreactive CD8+ clones derived from wild-type or fyn-/- mice serve as model systems which have allowed us to investigate several aspects of the molecular events associated with T cell-mediated cytotoxicity, including 1) the differential utilization of two distinct cytolytic pathways by CD4+ Th1 clones and CD8+ CTL, 2) a comparison of the pathways of lysis induced by stimulation of the TCR or by alternative stimuli, 3) the requirement of Fyn for derivation of antigen-specific T-cell clones having properties of CD4+ Th1 and CD8+ CTL cells 4) the differential requirement of Fyn in the induction of responses by TCR and the alternative stimuli. Stimulation through the TCR, either by APC bearing relevant antigen or by immobilized anti-CD3 mAb, resulted in comparable levels of target cell lysis by clones from both wild-type and fyn-/- mice. These clones also utilize the Fas pathway to lyse target cells. Thus, Fyn does not appear to be required for expression of the Fas pathway when triggered through the TCR. In contrast, lysis of target cells by T-cell clones lacking Fyn was deficient when stimulated through Thy-1 or Ly-6C (using mAb) or with Con A or phorbol ester as compared to clones derived from wild-type mice. The basis for the defect in response to stimulation through the GPI-linked molecules appears to be a signaling defect which affects all of the functional responses we measured, while the defect in response to Con A stimulation appears to affect lysis but not lymphokine production. Thus, Fyn expression is selectively required for efficient activation of the Fas pathway of lysis through Thy-1, Ly-6C, and by Con A or phorbol ester in these T-cell clones. CD8+ clones derived from fyn-/- mutant mice, like clones derived from wild-type mice, display antigen-specific lysis, and appear to express perforin message and perforin protein. A Ca(++)-dependent (presumably perforin/exocytosis) component and Fas component of lysis was

  17. GH and IGF1: Roles in Energy Metabolism of Long-Living GH Mutant Mice

    OpenAIRE

    Brown-Borg, Holly M.; Bartke, Andrzej

    2012-01-01

    Of the multiple theories to explain exceptional longevity, the most robust of these has centered on the reduction of three anabolic protein hormones, growth hormone (GH), insulin-like growth factor, and insulin. GH mutant mice live 50% longer and exhibit significant differences in several aspects of energy metabolism as compared with wild-type mice. Mitochondrial metabolism is upregulated in the absence of GH, whereas in GH transgenic mice and dwarf mice treated with GH, multiple aspects of t...

  18. WD40 domain of Apc1 is critical for the coactivator-induced allosteric transition that stimulates APC/C catalytic activity.

    Science.gov (United States)

    Li, Qiuhong; Chang, Leifu; Aibara, Shintaro; Yang, Jing; Zhang, Ziguo; Barford, David

    2016-09-20

    The anaphase-promoting complex/cyclosome (APC/C) is a large multimeric cullin-RING E3 ubiquitin ligase that orchestrates cell-cycle progression by targeting cell-cycle regulatory proteins for destruction via the ubiquitin proteasome system. The APC/C assembly comprises two scaffolding subcomplexes: the platform and the TPR lobe that together coordinate the juxtaposition of the catalytic and substrate-recognition modules. The platform comprises APC/C subunits Apc1, Apc4, Apc5, and Apc15. Although the role of Apc1 as an APC/C scaffolding subunit has been characterized, its specific functions in contributing toward APC/C catalytic activity are not fully understood. Here, we report the crystal structure of the N-terminal domain of human Apc1 (Apc1N) determined at 2.2-Å resolution and provide an atomic-resolution description of the architecture of its WD40 (WD40 repeat) domain (Apc1(WD40)). To understand how Apc1(WD40) contributes to APC/C activity, a mutant form of the APC/C with Apc1(WD40) deleted was generated and evaluated biochemically and structurally. We found that the deletion of Apc1(WD40) abolished the UbcH10-dependent ubiquitination of APC/C substrates without impairing the Ube2S-dependent ubiquitin chain elongation activity. A cryo-EM structure of an APC/C-Cdh1 complex with Apc1(WD40) deleted showed that the mutant APC/C is locked into an inactive conformation in which the UbcH10-binding site of the catalytic module is inaccessible. Additionally, an EM density for Apc15 is not visible. Our data show that Apc1(WD40) is required to mediate the coactivator-induced conformational change of the APC/C that is responsible for stimulating APC/C catalytic activity by promoting UbcH10 binding. In contrast, Ube2S activity toward APC/C substrates is not dependent on the initiation-competent conformation of the APC/C.

  19. Dietary ω-3 Polyunsaturated Fatty Acids Inhibit Tumor Growth in Transgenic Apc(Min/+) Mice, Correlating with CB1 Receptor Up-Regulation.

    Science.gov (United States)

    Notarnicola, Maria; Tutino, Valeria; De Nunzio, Valentina; Dituri, Francesco; Caruso, Maria Gabriella; Giannelli, Gianluigi

    2017-02-24

    Mediterranean diet components, such as olive oil and ω-3 polyunsaturated fatty acids (ω-3 PUFAs), can arrest cell growth and promote cell apoptosis. Recently, olive oil has been demonstrated to modulate type-1 cannabinoid (CB1) receptor gene expression in both human colon cancer cells and rat colon. The aim of this study was to investigate a possible link between olive oil and ω-3 PUFAs effects and CB1 receptor expression in both intestinal and adipose tissue of Apc(Min/+) mice. To confirm the role for the CB1 receptor as a negative modulator of cell proliferation in human colon cancer, CB1 receptor gene expression was also detected in tumor tissue and in surrounding normal mucosa of patients with colorectal cancer (CRC). Dietary ω-3 PUFAs significantly inhibited intestinal polyp growth in mice, correlating with CB1 receptor gene and protein expression induction. CB1 receptor gene up-regulation was also detected in adipose tissue, suggesting a close communication between cancer cells and the surrounding environment. Tissue CB1 receptor induction was associated with a concurrent inactivation of the Wnt/β-catenin pathway. Moreover, there was a significant reduction in CB1 receptor gene expression levels in cancer tissue compared to normal surrounding mucosa of patients with CRC, confirming that in cancer the "protective" action of the CB1 receptor is lost.

  20. Dietary anthocyanin-rich tart cherry extract inhibits intestinal tumorigenesis in APC(Min) mice fed suboptimal levels of sulindac.

    Science.gov (United States)

    Bobe, Gerd; Wang, Bing; Seeram, Navindra P; Nair, Muraleedharan G; Bourquin, Leslie D

    2006-12-13

    A promising approach for cancer chemoprevention might be a combination therapy utilizing dietary phytochemicals and anticarcinogenic pharmaceuticals at a suboptimal dosage to minimize any potential adverse side effects. To test this hypothesis, various dosages of anthocyanin-rich tart cherry extract were fed in combination with suboptimal levels of the nonsteroidal anti-inflammatory drug sulindac to APCMin mice for 19 weeks. By the end of the feeding period, fewer mice that were fed the anthocyanin-rich extract in combination with sulindac lost more than 10% of body weight than mice fed sulindac alone. Mice that were fed anthocyanin-rich extract (at any dose) in combination with sulindac had fewer tumors and a smaller total tumor burden (total tumor area per mouse) in the small intestine when compared to mice fed sulindac alone. These results suggest that a dietary combination of tart cherry anthocyanins and sulindac is more protective against colon cancer than sulindac alone.

  1. A conditionally lethal mutant of Salmonella Typhimurium induces a protective response in mice.

    Science.gov (United States)

    Hidalgo, Alejandro A; Villagra, Nicolás A; Jerez, Sebastián A; Fuentes, Juan A; Mora, Guido C

    2016-02-01

    Here we present the design of a conditionally lethal mutant of Salmonella enterica serovar Typhimurium (S. Typhimurium) which growth depends on tetracycline (Tet). Four mutants of S. Typhimurium, with Tet-conditional growth, were created by inserting the tetRA cassette. Three of the mutants presented a conditional-lethal phenotype in vitro. One mutant in the yabB gene remained conditional inside cells and did not persisted after 24 h in cell cultures. The capacity of S. Typhimurium yabB::tetRA to invade deep organs was investigated in intraperitoneally (IP) infected mice fed with or without chlortetracycline (CTet), a Tet analog with lower antibiotic activity. The yabB::tetRA mutant was undetectable in liver or spleen of animals under normal diet, while in mice under diet including CTet, yabB::tetRA invaded at a level comparable to the WT in mice under normal diet. Moreover, yabB::tetRA produced a strong humoral-immunoresponse after one IP immunization with 10(6) bacteria, measured as serum reactivity against S. Typhimurium whole cell extract. By contrast, oral immunization with 10(6) bacteria was weaker and variable on inducing antibodies. Consistently, IP infected mice were fully protected in a challenge with 10(4) oral S. Typhimurium, while protection was partial in orally immunized mice. Our data indicate that S. Typhimurium yabB::tetRA is a conditionally attenuated strain capable of inducing a protective response in mice in non-permissive conditions.

  2. Mapping Mammary Epithelial Cell Transformation in BRCA1 Mutant Mice

    Science.gov (United States)

    2006-07-01

    1808 1858 2031 2025 18 mice FEMALE (1656) J-CrelFLOX+/+ X (2033) J-Cre/FLOX+/+/p-/- FEMALE (1656) J-Cre/FLOX+/+ X (2033) J-Cre/FLOX+/+/p-/- FEMALE (1656...J+ 1833 1689 1692 1493/1434 1851 1848 1849 1868 1870 1871 1869 1872 1656 1862 1655 1657 1665 1493/1434 18 mice FEMALE (1417/1244) J-Cre/FLOX+/- X... mice FEMALE (1655) J-Cre FLOX+/+ X (2063) J-Cre/FLOX+/+p+/- FEMALE (1809)J-Cre/FLOX+/+/p+/- X (1659) FLOX+/+ FEMALE (1809)J-Cre/FLOX+/+/p+/- X (1659

  3. Polk Mutant Mice Have a Spontaneous Mutator Phenotype

    Science.gov (United States)

    Stancel, J. Nicole Kosarek; McDaniel, Lisa D.; Velasco, Susana; Richardson, James; Guo, Caixia; Friedberg, Errol C.

    2009-01-01

    Mice defective in the Polk gene (which encodes DNA polymerase kappa) are viable and do not manifest obvious phenotypes. The present studies document a spontaneous mutator phenotype in Polk−/− mice. The initial indication of enhanced spontaneous mutations in these mice came from the serendipitous observation of a postulated founder mutation that manifested in multiple disease states among a cohort of mice comprising all three possible Polk genotypes. Polk−/− and isogenic wild type controls carrying a reporter transgene (the λ-phage cII gene) were used for subsequent quantitative and qualitative studies on mutagenesis in various tissues. We observed significantly increased mutation frequencies in the kidney, liver, and lung of Polk−/− mice, but not in the spleen or testis. G:C base pairs dominated the mutation spectra of the kidney, liver, and lung. These results are consistent with the notion that Polκ is required for accurate translesion DNA synthesis past naturally occurring polycyclic guanine adducts, possibly generated by cholesterol and/or its metabolites. PMID:19783230

  4. High dietary niacin may increase prostaglandin formation but does not increase tumor formation in ApcMin/+ mice

    OpenAIRE

    Kwong, Alan M.; Tippin, Brigette L.; Materi, Alicia M.; Buslon, Virgilio S; French, Samuel W.; Lin, Henry J.

    2011-01-01

    High doses of niacin (nicotinic acid) used to treat dyslipidemias cause flushing, due to high levels of prostaglandin D2 (PGD2). GPR109A, a G-protein coupled receptor, triggers the flushing in the skin. In addition to boosting PGD2, niacin binding to GPR109A activates the entire prostanoid cascade. We found that GPR109A occurs throughout the gastrointestinal tract. Mice that alternated between a 1% niacin diet and a control diet had higher urinary prostaglandin E2 (PGE2) metabolite levels whe...

  5. Metabolic and Phenotypic Differences between Mice Producing a Werner Syndrome Helicase Mutant Protein and Wrn Null Mice.

    Science.gov (United States)

    Aumailley, Lucie; Garand, Chantal; Dubois, Marie Julie; Johnson, F Brad; Marette, André; Lebel, Michel

    2015-01-01

    Werner syndrome (WS) is a premature aging disorder caused by mutations in a RecQ-family DNA helicase, WRN. Mice lacking part of the helicase domain of the WRN orthologue exhibit many phenotypic features of WS, including metabolic abnormalities and a shorter mean life span. In contrast, mice lacking the entire Wrn protein (i.e. Wrn null mice) do not exhibit a premature aging phenotype. In this study, we used a targeted mass spectrometry-based metabolomic approach to identify serum metabolites that are differentially altered in young Wrn helicase mutant and Wrn null mice. An antibody-based quantification of 43 serum cytokines and markers of cardiovascular disease risk complemented this study. We found that Wrn helicase mutants exhibited elevated and decreased levels, respectively, of the anti-inflammatory cytokine IL-10 and the pro-inflammatory cytokine IL-18. Wrn helicase mutants also exhibited an increase in serum hydroxyproline and plasminogen activator inhibitor-1, markers of extracellular matrix remodeling of the vascular system and inflammation in aging. We also observed an abnormal increase in the ratio of very long chain to short chain lysophosphatidylcholines in the Wrn helicase mutants underlying a peroxisome perturbation in these mice. Remarkably, the Wrn mutant helicase protein was mislocalized to the endoplasmic reticulum and the peroxisomal fractions in liver tissues. Additional analyses with mouse embryonic fibroblasts indicated a severe defect of the autophagy flux in cells derived from Wrn helicase mutants compared to wild type and Wrn null animals. These results indicate that the deleterious effects of the helicase-deficient Wrn protein are mediated by the dysfunction of several cellular organelles.

  6. Metabolic and Phenotypic Differences between Mice Producing a Werner Syndrome Helicase Mutant Protein and Wrn Null Mice.

    Directory of Open Access Journals (Sweden)

    Lucie Aumailley

    Full Text Available Werner syndrome (WS is a premature aging disorder caused by mutations in a RecQ-family DNA helicase, WRN. Mice lacking part of the helicase domain of the WRN orthologue exhibit many phenotypic features of WS, including metabolic abnormalities and a shorter mean life span. In contrast, mice lacking the entire Wrn protein (i.e. Wrn null mice do not exhibit a premature aging phenotype. In this study, we used a targeted mass spectrometry-based metabolomic approach to identify serum metabolites that are differentially altered in young Wrn helicase mutant and Wrn null mice. An antibody-based quantification of 43 serum cytokines and markers of cardiovascular disease risk complemented this study. We found that Wrn helicase mutants exhibited elevated and decreased levels, respectively, of the anti-inflammatory cytokine IL-10 and the pro-inflammatory cytokine IL-18. Wrn helicase mutants also exhibited an increase in serum hydroxyproline and plasminogen activator inhibitor-1, markers of extracellular matrix remodeling of the vascular system and inflammation in aging. We also observed an abnormal increase in the ratio of very long chain to short chain lysophosphatidylcholines in the Wrn helicase mutants underlying a peroxisome perturbation in these mice. Remarkably, the Wrn mutant helicase protein was mislocalized to the endoplasmic reticulum and the peroxisomal fractions in liver tissues. Additional analyses with mouse embryonic fibroblasts indicated a severe defect of the autophagy flux in cells derived from Wrn helicase mutants compared to wild type and Wrn null animals. These results indicate that the deleterious effects of the helicase-deficient Wrn protein are mediated by the dysfunction of several cellular organelles.

  7. Enhanced hippocampal long-term potentiation and fear memory in Btbd9 mutant mice.

    Directory of Open Access Journals (Sweden)

    Mark P DeAndrade

    Full Text Available Polymorphisms in BTBD9 have recently been associated with higher risk of restless legs syndrome (RLS, a neurological disorder characterized by uncomfortable sensations in the legs at rest that are relieved by movement. The BTBD9 protein contains a BTB/POZ domain and a BACK domain, but its function is unknown. To elucidate its function and potential role in the pathophysiology of RLS, we generated a line of mutant Btbd9 mice derived from a commercial gene-trap embryonic stem cell clone. Btbd9 is the mouse homolog of the human BTBD9. Proteins that contain a BTB/POZ domain have been reported to be associated with synaptic transmission and plasticity. We found that Btbd9 is naturally expressed in the hippocampus of our mutant mice, a region critical for learning and memory. As electrophysiological characteristics of CA3-CA1 synapses of the hippocampus are well characterized, we performed electrophysiological recordings in this region. The mutant mice showed normal input-output relationship, a significant impairment in pre-synaptic activity, and an enhanced long-term potentiation. We further performed an analysis of fear memory and found the mutant mice had an enhanced cued and contextual fear memory. To elucidate a possible molecular basis for these enhancements, we analyzed proteins that have been associated with synaptic plasticity. We found an elevated level of dynamin 1, an enzyme associated with endocytosis, in the mutant mice. These results suggest the first identified function of Btbd9 as being involved in regulating synaptic plasticity and memory. Recent studies have suggested that enhanced synaptic plasticity, analogous to what we have observed, in other regions of the brain could enhance sensory perception similar to what is seen in RLS patients. Further analyses of the mutant mice will help shine light on the function of BTBD9 and its role in RLS.

  8. The E3 Ligase APC/C-Cdh1 Is Required for Associative Fear Memory and Long-Term Potentiation in the Amygdala of Adult Mice

    Science.gov (United States)

    Pick, Joseph E.; Malumbres, Marcos; Klann, Eric

    2013-01-01

    The anaphase promoting complex/cyclosome (APC/C) is an E3 ligase regulated by Cdh1. Beyond its role in controlling cell cycle progression, APC/C-Cdh1 has been detected in neurons and plays a role in long-lasting synaptic plasticity and long-term memory. Herein, we further examined the role of Cdh1 in synaptic plasticity and memory by generating…

  9. Calreticulin mutants in mice induce an MPL-dependent thrombocytosis with frequent progression to myelofibrosis.

    Science.gov (United States)

    Marty, Caroline; Pecquet, Christian; Nivarthi, Harini; El-Khoury, Mira; Chachoua, Ilyas; Tulliez, Micheline; Villeval, Jean-Luc; Raslova, Hana; Kralovics, Robert; Constantinescu, Stefan N; Plo, Isabelle; Vainchenker, William

    2016-03-10

    Frameshift mutations in the calreticulin (CALR) gene are seen in about 30% of essential thrombocythemia and myelofibrosis patients. To address the contribution of the CALR mutants to the pathogenesis of myeloproliferative neoplasms, we engrafted lethally irradiated recipient mice with bone marrow cells transduced with retroviruses expressing these mutants. In contrast to wild-type CALR, CALRdel52 (type I) and, to a lesser extent, CALRins5 (type II) induced thrombocytosis due to a megakaryocyte (MK) hyperplasia. Disease was transplantable into secondary recipients. After 6 months, CALRdel52-, in contrast to rare CALRins5-, transduced mice developed a myelofibrosis associated with a splenomegaly and a marked osteosclerosis. Monitoring of virus-transduced populations indicated that CALRdel52 leads to expansion at earlier stages of hematopoiesis than CALRins5. However, both mutants still specifically amplified the MK lineage and platelet production. Moreover, a mutant deleted of the entire exon 9 (CALRdelex9) did not induce a disease, suggesting that the oncogenic property of CALR mutants was related to the new C-terminus peptide. To understand how the CALR mutants target the MK lineage, we used a cell-line model and demonstrated that the CALR mutants, but not CALRdelex9, specifically activate the thrombopoietin (TPO) receptor (MPL) to induce constitutive activation of Janus kinase 2 and signal transducer and activator of transcription 5/3/1. We confirmed in c-mpl- and tpo-deficient mice that expression of Mpl, but not of Tpo, was essential for the CALR mutants to induce thrombocytosis in vivo, although Tpo contributes to disease penetrance. Thus, CALR mutants are sufficient to induce thrombocytosis through MPL activation. © 2016 by The American Society of Hematology.

  10. Impaired learning and memory in CD38 null mutant mice.

    Science.gov (United States)

    Kim, Somi; Kim, TaeHyun; Lee, Hye-Ryeon; Jang, Eun-Hye; Ryu, Hyun-Hee; Kang, Minkyung; Rah, So-Young; Yoo, Juyoun; Lee, Bolam; Kim, Jae-Ick; Lim, Chae Seok; Kim, Sang Jeong; Kim, Uh-Hyun; Lee, Yong-Seok; Kaang, Bong-Kiun

    2016-02-09

    CD38 is an enzyme that catalyzes the formation of cyclic ADP ribose and nicotinic acid adenine dinucleotide phosphate, both of which are involved in the mobilization of Ca(2+) from intracellular stores. Recently, CD38 has been shown to regulate oxytocin release from hypothalamic neurons. Importantly, CD38 mutations are associated with autism spectrum disorders (ASD) and CD38 knockout (CD38(-/-)) mice display ASD-like behavioral phenotypes including deficient parental behavior and poor social recognition memory. Although ASD and learning deficits commonly co-occur, the role of CD38 in learning and memory has not been investigated. We report that CD38(-/-) mice show deficits in various learning and memory tasks such as the Morris water maze, contextual fear conditioning, and the object recognition test. However, either long-term potentiation or long-term depression is not impaired in the hippocampus of CD38(-/-) mice. Our results provide convincing evidence that CD38(-/-) mice show deficits in various learning and memory tasks including spatial and non-spatial memory tasks. Our data demonstrate that CD38 is critical for regulating hippocampus-dependent learning and memory without modulating synaptic plasticity.

  11. Changes of motor abilities during ontogenetic development in Lurcher mutant mice.

    Science.gov (United States)

    Markvartová, V; Cendelín, J; Vozeh, F

    2010-07-14

    Lurcher mutant mice represent a natural model of olivocerebellar degeneration. This degeneration is caused by a mutation of the gene for the delta2 glutamate receptor. Lurcher mutants suffer from cerebellar ataxia and cognitive functions deficiency as a consequence of excitotoxic apoptosis of Purkinje cells in the cerebellar cortex and a secondary decrease of granule cells and inferior olive neurons. This process finishes by the 90th day of postnatal life, but already by 14 days, the Purkinje cells are damaged and the ataxia is fully developed. Purkinje cells die by apoptosis within the first 3 weeks of life. The aim of our work was to study the development of motor functions in the course of the ontogenetic development in Lurcher mutant mice of the B6CBA strain and to compare it with wild type mice of the same strain. Mice aged 2, 3, 6, 9, and 22 weeks were used in our experiment. Motor skills were examined using four standard tests: the horizontal wire, rotating cylinder, footbridge and slanting ladder. Our findings in Lurcher mutant mice show a significant increase of motor abilities up to the sixth postnatal week and selective decrease early after this period. This improvement of motor skills is caused by the physiological development of musculature and the nervous system, probably with some contribution of plasticity of the maturing brain. The cause of the decline of these abilities immediately after the completion of the development is unknown.

  12. Effects of Pharmacologic and Genetic Inhibition of Alk on Cognitive Impairments in NF1 Mutant Mice

    Science.gov (United States)

    2016-08-01

    behavioral and cognitive testing than originally anticipated. In addition, as a minimal number of mice was provided to us for breeding of the NF1 and Alk...AWARD NUMBER: W81XWH-13-1-0117 TITLE: Effects of Pharmacologic and Genetic Inhibition of Alk on Cognitive Impairments in NF1 Mutant Mice...including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and

  13. Increased proximal bifurcation of CA1 pyramidal apical dendrites in sema3A mutant mice.

    Science.gov (United States)

    Nakamura, Fumio; Ugajin, Kozue; Yamashita, Naoya; Okada, Takako; Uchida, Yutaka; Taniguchi, Masahiko; Ohshima, Toshio; Goshima, Yoshio

    2009-10-10

    Semaphorin-3A (Sema3A) is an attractive guidance molecule for cortical apical dendrites. To elucidate the role of Sema3A in hippocampal dendritic formation, we examined the Sema3A expression pattern in the perinatal hippocampal formation and analyzed hippocampal dendrites of the brains from young adult sema3A mutant mice. Sema3A protein was predominantly expressed in the hippocampal plate and the inner marginal zone at the initial period of apical dendritic growth. Neuropilin-1 and plexin-A, the receptor components for Sema3A, were also localized in the same regions. The Golgi impregnation method revealed that in wildtype mice more than 90% of hippocampal CA1 pyramidal neurons extended a single trunk or apical trunks bifurcated in stratum radiatum. Seven percent of the pyramidal neurons showed proximal bifurcation of apical trunks in stratum pyramidale or at the border of the stratum pyramidale and stratum radiatum. In sema3A mutant mice, proximally bifurcated apical dendrites were increased to 32%, while the single apical dendritic pyramidal neurons were decreased. We designate this phenotype in sema3A mutant mice as "proximal bifurcation." In the dissociated culture system, approximately half of the hippocampal neurons from wildtype mice resembled pyramidal neurons, which possess a long, thick, and tapered dendrite. In contrast, only 30% of the neurons from sema3A mutants exhibited pyramidal-like morphology. Proximal bifurcation of CA1 pyramidal neurons was also increased in the mutant mice of p35, an activator of cyclin-dependent kinase 5 (Cdk5). Thus, Sema3A may facilitate the initial growth of CA1 apical dendrites via the activation of p35/Cdk5, which may in turn signal hippocampal development.

  14. Mutant Mice Lacking the p53 C-Terminal Domain Model Telomere Syndromes

    NARCIS (Netherlands)

    Simeonova, I.; Jaber, S.; Draskovic, I.; Bardot, B.; Fang, M.; Bouarich-Bourimi, R.; Lejour, V.; Charbonnier, L.; Soudais, C.; Bourdon, J.C.; Huerre, M.; Londono-Vallejo, A.; Toledo, F.

    2013-01-01

    Mutations in p53, although frequent in human cancers, have not been implicated in telomere-related syndromes. Here, we show that homozygous mutant mice expressing p53(Delta31), a p53 lacking the C-terminal domain, exhibit increased p53 activity and suffer from aplastic anemia and pulmonary fibrosis,

  15. Impaired insulin secretion and glucose intolerance in synaptotagmin-7 null mutant mice

    DEFF Research Database (Denmark)

    Gustavsson, Natalia; Lao, Ye; Maximov, Anton;

    2008-01-01

    secretion in pancreatic beta-cells. Of these other synaptotagmins, synaptotagmin-7 is one of the most abundant and is present in pancreatic beta-cells. To determine whether synaptotagmin-7 regulates Ca(2+)-dependent insulin secretion, we analyzed synaptotagmin-7 null mutant mice for glucose tolerance...

  16. Deficiency of antinociception and excessive grooming induced by acute immobilization stress in Per1 mutant mice.

    Science.gov (United States)

    Zhang, Jing; Wu, Zhouqiao; Zhou, Linglin; Li, Huili; Teng, Huajing; Dai, Wei; Wang, Yongqing; Sun, Zhong Sheng

    2011-01-14

    Acute stressors induce changes in numerous behavioral parameters through activation of the hypothalamic-pituitary-adrenal (HPA) axis. Several important hormones in paraventricular nucleus of the hypothalamus (PVN) play the roles in these stress-induced reactions. Corticotropin-releasing hormone (CRH), arginine-vasopressin (AVP) and corticosterone are considered as molecular markers for stress-induced grooming behavior. Oxytocin in PVN is an essential modulator for stress-induced antinociception. The clock gene, Per1, has been identified as an effecter response to the acute stresses, but its function in neuroendocrine stress systems remains unclear. In the present study we observed the alterations in grooming and nociceptive behaviors induced by acute immobilization stress in Per1 mutant mice and other genotypes (wild types and Per2 mutant). The results displayed that stress elicited a more robust effect on grooming behavior in Per1 mutant mice than in other genotypes. Subsequently, the obvious stress-induced antinociception was observed in the wild-type and Per2 mutant mice, however, in Per1 mutant, this antinociceptive effects were partially-reversed (mechanical sensitivity), or over-reversed to hyperalgesia (thermal sensitivity). The real-time qPCR results showed that in PVN, there were stress-induced up-regulations of Crh, Avp and c-fos in all of genotypes; moreover, the expression change of Crh in Per1 mutant mice was much larger than in others. Another hormonal gene, Oxt, was up-regulated induced by stress in wild-type and Per2 mutant but not in Per1 mutant. In addition, the stress significantly elevated the serum corticosterone levels without genotype-dependent differences, and accordingly the glucocorticoid receptor gene, Nr3c1, expressed with a similar pattern in PVN of all strains. Taken together, the present study indicated that in acute stress treated Per1 mutant mice, there are abnormal hormonal responses in PVN, correlating with the aberrant

  17. Temperature-sensitive mutants of Actinobacillus pleuropneumoniae induce protection in mice.

    Science.gov (United States)

    Byrd, W; Hooke, A M

    1997-01-01

    Temperature-sensitive mutants of Actinobacillus pleuropneumoniae 4074, serotype 1, were isolated after treatment with nitrosoguanidine and enrichment with penicillin and D-cycloserine. Of the four temperature-sensitive mutants evaluated in mice, one (A-1) had a tight phenotype (i.e., it ceased replication immediately after transfer to the nonpermissive temperature [37 degrees C]) and three (1-2, 4-1, and 12-1) were coasters that continued replication for up to three generations after transfer to 37 degrees C. The reversion frequencies ranged from 10(-6) to 10(-9), and cutoff temperatures ranged from 33 to 35 degrees C. No major changes were detected in the biochemical profiles; agglutination reactions; electrophoretic profiles of the lipopolysaccharides, outer membrane proteins, and hemolysin proteins; hemolytic titers; or CAMP factor reactions of the mutants and the wild-type bacteria. Groups of 3- to 5-week-old, female ICR mice were immunized intranasally with three doses of 3.5 x 10(6) CFU of the mutants over 3 weeks and subsequently challenged intranasally with 5 50% lethal doses of the parental wild-type. Protection was induced by both the tight and the coaster mutants, with the 4-1 and 12-1 coasters eliciting greater protection (67 and 82%, respectively) than that induced by the A-1 tight mutant (57%). Intranasal immunization with both phenotypes induced serum antibody responses against the surface antigens and the hemolysin protein. PMID:9169752

  18. Pharmacological inhibition of Anaplastic Lymphoma Kinase rescues spatial memory impairments in Neurofibromatosis 1 mutant mice.

    Science.gov (United States)

    Weiss, Joseph B; Weber, Sydney; Marzulla, Tessa; Raber, Jacob

    2017-08-14

    Heterozygous Neurofibromatosis 1 (NF1) loss of function mutations are found in 90% of patients with neurofibromatosis, a syndrome associated with disabling cognitive impairment. Drosophila studies have demonstrated a genetic interaction between Anaplastic Lymphoma Kinase (Alk) and NF1 in cognitive performance. In addition, pharmacologic inhibition of Alk improves cognitive performance in heterozygous NF1 mutant flies. In this study, we tested whether pharmacological inhibition of Alk in heterozygous NF1 mutant mice attenuates or rescues cognitive impairments. Cognitive impairment of spatial memory retention observed in heterozygous NF1 mutant mice was rescued by the Alk inhibitor. These data support the hypothesis that inhibition of Alk may cognitively benefit patients with Neurofibromatosis 1. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. The Anaphase-Promoting Complex (APC ubiquitin ligase affects chemosensory behavior in C. elegans

    Directory of Open Access Journals (Sweden)

    Julia Wang

    2016-05-01

    Full Text Available The regulation of fundamental aspects of neurobiological function has been linked to the ubiquitin signaling system (USS, which regulates the degradation and activity of proteins and is catalyzed by E1, E2, and E3 enzymes. The Anaphase-Promoting Complex (APC is a multi-subunit E3 ubiquitin ligase that controls diverse developmental and signaling processes in post-mitotic neurons; however, potential roles for the APC in sensory function have yet to be explored. In this study, we examined the effect of the APC ubiquitin ligase on chemosensation in Caenorhabditis elegans by testing chemotaxis to the volatile odorants, diacetyl, pyrazine, and isoamyl alcohol, to which wild-type worms are attracted. Animals with loss of function mutations in either of two alleles (g48 and ye143 of the gene encoding the APC subunit EMB-27 APC6 showed increased chemotaxis towards diacetyl and pyrazine, odorants sensed by AWA neurons, but exhibited normal chemotaxis to isoamyl alcohol, which is sensed by AWC neurons. The statistically significant increase in chemotaxis in the emb-27 APC6 mutants suggests that the APC inhibits AWA-mediated chemosensation in C. elegans. Increased chemotaxis to pyrazine was also seen with mutants lacking another essential APC subunit, MAT-2 APC1; however, mat-2 APC1 mutants exhibited wild type responses to diacetyl. The difference in responsiveness of these two APC subunit mutants may be due to differential strength of these hypomorphic alleles or may indicate the presence of functional sub-complexes of the APC at work in this process. These findings are the first evidence for APC-mediated regulation of chemosensation and lay the groundwork for further studies aimed at identifying the expression levels, function, and targets of the APC in specific sensory neurons. Because of the similarity between human and C. elegans nervous systems, the role of the APC in sensory neurons may also advance our understanding of human sensory function and

  20. Weaver mutant mice exhibit long-term learning deficits under several measures of instrumental behavior.

    Science.gov (United States)

    Derenne, Adam; Arsenault, Matthew L; Austin, David P; Weatherly, Jeffrey N

    2007-12-01

    Homozygous weaver mutant mice (wv/wv) exhibit symptoms that parallel Parkinson's disease, including motor deficits and the destruction of dopaminergic neurons as well as degeneration in the cerebellum and hippocampus. To develop a more complete behavioral profile of these organisms, groups of wv/wv, wv/+ mice and C57BL/6 mice were observed on a within-subjects basis under a fixed-interval schedule of reinforcement, a differential-reinforcement-of-low-rate-of-responding schedule, and a discrimination task in which a saccharin solution and tap water were concurrently available from two food cups. Under both reinforcement schedules, the wv/wv mice responded as frequently as the comparison subjects, but they responded in a manner that was inappropriate to the contingencies. Rather than respond with increasing frequency as the upcoming reinforcer became temporally proximate, wv/wv mice responded with decreasing probability as a function of the time since the previous reinforcer. Under the discrimination task, the wv/wv mice, unlike the controls, obtained saccharin over tap water at the level of chance. The findings suggest that weaver mutant mice express learning deficits similar to those found in other dopamine-deficient organisms.

  1. MitoRCA-seq reveals unbalanced cytocine to thymine transition in Polg mutant mice.

    Science.gov (United States)

    Ni, Ting; Wei, Gang; Shen, Ting; Han, Miao; Lian, Yaru; Fu, Haihui; Luo, Yan; Yang, Yanqin; Liu, Jie; Wakabayashi, Yoshi; Li, Zheng; Finkel, Toren; Xu, Hong; Zhu, Jun

    2015-07-27

    Mutations in mitochondrial DNA (mtDNA) can lead to a wide range of human diseases. We have developed a deep sequencing strategy, mitoRCA-seq, to detect low-frequency mtDNA point mutations starting with as little as 1 ng of total DNA. It employs rolling circle amplification, which enriches the full-length circular mtDNA by either custom mtDNA-specific primers or a commercial kit, and minimizes the contamination of nuclear encoded mitochondrial DNA (Numts). By analyzing the mutation profiles of wild-type and Polg (mitochondrial DNA polymerase γ) mutant mice, we found that mice with the proofreading deficient mtDNA polymerase have a significantly higher mutation load by expanding the number of mutation sites and to a lesser extent by elevating the mutation frequency at existing sites even before the premature aging phenotypes appear. Strikingly, cytocine (C) to thymine (T) transitions are found to be overrepresented in the mtDNA of Polg mutated mice. The C → T transition, compared to other types of mutations, tends to increase the hydrophobicity of the underlying amino acids, and may contribute to the impaired protein function of the Polg mutant mice. Taken together, our findings may provide clues to further investigate the molecular mechanism underlying premature aging phenotype in Polg mutant mice.

  2. Cox4i2, Ifit2, and Prdm11 Mutant Mice

    DEFF Research Database (Denmark)

    Horsch, Marion; Aguilar-Pimentel, Juan Antonio; Bönisch, Clemens

    2015-01-01

    and repeated OVA airway challenge. Challenged Prdm11tm1.1ahl mice exhibited changes in B cell counts, CD4+ T cell counts, and in the number of neutrophils in bronchoalveolar lavages, whereas challenged Ifit2tm1.1Ebsb mice displayed alterations in plasma IgE, IgG1, IgG3, and IgM levels compared...... to the challenged wild type littermates. In contrast, challenged Cox4i2tm1Hutt mutant mice did not show alterations in the humoral or cellular immune response compared to challenged wild type mice. Transcriptome analyses from lungs of the challenged mutant mouse lines showed extensive changes in gene expression...... in Prdm11tm1.1ahl mice. Functional annotations of regulated genes of all three mutant mouse lines were primarily related to inflammation and airway smooth muscle (ASM) remodeling. We were thus able to define an effective selection strategy to identify new candidate genes for the predisposition...

  3. Characteristics of gait ataxia in δ2 glutamate receptor mutant mice, ho15J.

    Directory of Open Access Journals (Sweden)

    Eri Takeuchi

    Full Text Available The cerebellum plays a fundamental, but as yet poorly understood, role in the control of locomotion. Recently, mice with gene mutations or knockouts have been used to investigate various aspects of cerebellar function with regard to locomotion. Although many of the mutant mice exhibit severe gait ataxia, kinematic analyses of limb movements have been performed in only a few cases. Here, we investigated locomotion in ho15J mice that have a mutation of the δ2 glutamate receptor. The cerebellum of ho15J mice shows a severe reduction in the number of parallel fiber-Purkinje synapses compared with wild-type mice. Analysis of hindlimb kinematics during treadmill locomotion showed abnormal hindlimb movements characterized by excessive toe elevation during the swing phase, and by severe hyperflexion of the ankles in ho15J mice. The great trochanter heights in ho15J mice were lower than in wild-type mice throughout the step cycle. However, there were no significant differences in various temporal parameters between ho15J and wild-type mice. We suggest that dysfunction of the cerebellar neuronal circuits underlies the observed characteristic kinematic abnormality of hindlimb movements during locomotion of ho15J mice.

  4. Deletion and interallelic complementation analysis of Steel mutant mice

    Energy Technology Data Exchange (ETDEWEB)

    Bedell, M.A.; Cleveland, L.S.; Copeland, N.G. [NCI-Frederick Cancer Research and Development Center, MD (United States)] [and others

    1996-03-01

    Mutations at the Steel (Sl) locus produce pleiotropic effects on viability as well as hematopoiesis, pigmentation and fertility. Several homozygous viable Sl alleles have previously have been shown to contain either structural alterations in mast cell growth factor (Mgf) or regulatory mutations that affect expression of the Mgf gene. More severe Sl alleles cause lethality to homozygous embryos and all lethal Sl alleles examined to date contain deletions that remove the entire Mgf coding region. As the timing of the lethality varies from early to late in gestation, it is possible that some deletions may affect other closely linked genes in addition to Mgf. We have analyzed the extent of deleted sequences in seven homozygous lethal Sl alleles. The results of this analysis suggests that late gestation lethality represents the Sl null phenotype and that peri-implantation lethality results from the deletion of at least one essential gene that maps proximal to Sl. We have also examined gene dosage effects of Sl comparing the phenotypes of mice homozygous and hemizygous for each of four viable Sl alleles. Lastly, we show that certain combinations of the viable Sl alleles exhibit interallelic complementation. Possible mechanisms by which such complementation could occur are discussed. 39 refs., 3 figs., 3 tabs.

  5. Distinct neurobehavioural effects of cannabidiol in transmembrane domain neuregulin 1 mutant mice.

    Directory of Open Access Journals (Sweden)

    Leonora E Long

    Full Text Available The cannabis constituent cannabidiol (CBD possesses anxiolytic and antipsychotic properties. We have previously shown that transmembrane domain neuregulin 1 mutant (Nrg1 TM HET mice display altered neurobehavioural responses to the main psychoactive constituent of cannabis, Δ(9-tetrahydrocannabinol. Here we investigated whether Nrg1 TM HET mice respond differently to CBD and whether CBD reverses schizophrenia-related phenotypes expressed by these mice. Adult male Nrg1 TM HET and wild type-like littermates (WT received vehicle or CBD (1, 50 or 100 mg/kg i.p. for 21 days. During treatment and 48 h after withdrawal we measured behaviour, whole blood CBD concentrations and autoradiographic receptor binding. Nrg1 HET mice displayed locomotor hyperactivity, PPI deficits and reduced 5-HT(2A receptor binding density in the substantia nigra, but these phenotypes were not reversed by CBD. However, long-term CBD (50 and 100 mg/kg selectively enhanced social interaction in Nrg1 TM HET mice. Furthermore, acute CBD (100 mg/kg selectively increased PPI in Nrg1 TM HET mice, although tolerance to this effect was manifest upon repeated CBD administration. Long-term CBD (50 mg/kg also selectively increased GABA(A receptor binding in the granular retrosplenial cortex in Nrg1 TM HET mice and reduced 5-HT(2A binding in the substantia nigra in WT mice. Nrg1 appears necessary for CBD-induced anxiolysis since only WT mice developed decreased anxiety-related behaviour with repeated CBD treatment. Altered pharmacokinetics in mutant mice could not explain our findings since no genotype differences existed in CBD blood concentrations. Here we demonstrate that Nrg1 modulates acute and long-term neurobehavioural effects of CBD, which does not reverse the schizophrenia-relevant phenotypes.

  6. Selective knockdown of mutant SOD1 in Schwann cells ameliorates disease in G85R mutant SOD1 transgenic mice.

    Science.gov (United States)

    Wang, Lijun; Pytel, Peter; Feltri, M Laura; Wrabetz, Lawrence; Roos, Raymond P

    2012-10-01

    Mutants of superoxide dismutase type 1 (mtSOD1) that have full dismutase activity (e.g., G37R) as well as none (e.g., G85R) cause familial amyotrophic lateral sclerosis (FALS), indicating that mtSOD1-induced FALS results from a toxicity rather than loss in SOD1 enzymatic activity. Still, it has remained unclear whether mtSOD1 dismutase activity can influence disease. A previous study demonstrated that Cre-mediated knockdown of G37R expression in Schwann cells (SCs) of G37R transgenic mice shortened the late phase of disease and survival. These results suggested that the neuroprotective effect of G37R expressed in SCs was greater than its toxicity, presumably because its dismutase activity counteracted reactive oxygen species (ROS). In order to further investigate this, we knocked down G85R in SCs by crossing G85R(flox) mice with myelin-protein-zero (P(0)):Cre mice, which express Cre recombinase in SCs. Knockdown of G85R in SCs of G85R mice delayed disease onset and extended survival indicating that G85R expression in SCs is neurotoxic. These results demonstrate differences in the effect on disease of dismutase active vs. inactive mtSOD1 suggesting that both a loss as well as gain in function of mtSOD1 influence FALS pathogenesis. The results suggest that mtSOD1-induced FALS treatment may have to be adjusted depending on the cell type targeted and particular mtSOD1 involved.

  7. Id2 deletion attenuates Apc-deficient ileal tumor formation

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    Kyoko Biyajima

    2015-08-01

    Full Text Available The expression level of inhibitor of DNA binding 2 (Id2 is increased in colorectal carcinomas and is positively correlated with poor prognosis. However, the functional significance of Id2 in intestinal tumorigenesis has not been fully defined using genetic approaches. Here, we show that Id2 promotes ileal tumor initiation in Apc-deficient mice. Expression of Id2 was stimulated by Wnt signaling through the enhancer region of the Id2 promoter at the early stage of tumorigenesis in Apc+/Δ716 (ApcΔ716 mice. Genetic depletion of Id2 in ApcΔ716 mice caused ∼80% reduction in the number of ileal polyps, but had little effect on tumor size. Notably, the lack of Id2 increased the number of apoptotic cells in the normal crypt epithelium of the mice. Furthermore, DNA microarray analysis revealed that the expression level of Max dimerization protein 1 (Mxd1, known as a c-Myc antagonist, was specifically increased by Id2 deletion in the ileal intestinal epithelium of ApcΔ716 mice. In contrast, the protein level of c-Myc, but not the mRNA level, was decreased by loss of Id2 in these mice. These results indicate that loss of Id2 inhibits tumor initiation by up-regulation of Mxd1 and down-regulation of c-Myc in ApcΔ716 mice.

  8. Brain beta-amyloid accumulation in transgenic mice expressing mutant superoxide dismutase 1.

    Science.gov (United States)

    Turner, Bradley J; Li, Qiao-Xin; Laughton, Katrina M; Masters, Colin L; Lopes, Elizabeth C; Atkin, Julie D; Cheema, Surindar S

    2004-12-01

    Oxidative stress is implicated in both the deposition and pathogenesis of beta-amyloid (Abeta) protein in Alzheimer's disease (AD). Accordingly, overexpression of the antioxidant enzyme superoxide dismutase 1 (SOD1) in neuronal cells and transgenic AD mice reduces Abeta toxicity and accumulation. In contrast, mutations in SOD1 associated with amyotrophic lateral sclerosis (ALS) confer enhanced pro-oxidative enzyme activities. We therefore examined whether ALS-linked mutant SOD1 overexpression in motor neuronal cells or transgenic ALS mice modulates Abeta toxicity or its accumulation in the brain. Aggregated, but not freshly solubilised, substrate-bound Abeta peptides induced degenerative morphology and cytotoxicity in motor neuron-like NSC-34 cells. Transfection of NSC-34 cells with human wild-type SOD1 attenuated Abeta-induced toxicity, however this neuroprotective effect was also observed for ALS-linked mutant SOD1. Analysis of the cerebral cortex, brainstem, cerebellum and olfactory bulb from transgenic SOD1G93A mice using enzyme-linked immunosorbent assay of acid-guanidine extracts revealed age-dependent elevations in Abeta levels, although not significantly different from wild-type mouse brain. In addition, brain amyloid protein precursor (APP) levels remained unaltered as a consequence of mutant SOD1 expression. We therefore conclude that mutant SOD1 overexpression promotes neither Abeta toxicity nor brain accumulation in these ALS models.

  9. Cancer stemness in Apc- vs. Apc/KRAS-driven intestinal tumorigenesis.

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    Mehrnaz Ghazvini

    Full Text Available Constitutive activation of the Wnt pathway leads to adenoma formation, an obligatory step towards intestinal cancer. In view of the established role of Wnt in regulating stemness, we attempted the isolation of cancer stem cells (CSCs from Apc- and Apc/KRAS-mutant intestinal tumours. Whereas CSCs are present in Apc/KRAS tumours, they appear to be very rare (<10(-6 in the Apc-mutant adenomas. In contrast, the Lin(-CD24(hiCD29(+ subpopulation of adenocarcinoma cells appear to be enriched in CSCs with increased levels of active β-catenin. Expression profiling analysis of the CSC-enriched subpopulation confirmed their enhanced Wnt activity and revealed additional differential expression of other signalling pathways, growth factor binding proteins, and extracellular matrix components. As expected, genes characteristic of the Paneth cell lineage (e.g. defensins are co-expressed together with stem cell genes (e.g. Lgr5 within the CSC-enriched subpopulation. This is of interest as it may indicate a cancer stem cell niche role for tumor-derived Paneth-like cells, similar to their role in supporting Lgr5(+ stem cells in the normal intestinal crypt. Overall, our results indicate that oncogenic KRAS activation in Apc-driven tumours results in the expansion of the CSCs compartment by increasing ®-catenin intracellular stabilization.

  10. Altered metabolism of growth hormone receptor mutant mice: a combined NMR metabonomics and microarray study.

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    Horst Joachim Schirra

    Full Text Available BACKGROUND: Growth hormone is an important regulator of post-natal growth and metabolism. We have investigated the metabolic consequences of altered growth hormone signalling in mutant mice that have truncations at position 569 and 391 of the intracellular domain of the growth hormone receptor, and thus exhibit either low (around 30% maximum or no growth hormone-dependent STAT5 signalling respectively. These mutations result in altered liver metabolism, obesity and insulin resistance. METHODOLOGY/PRINCIPAL FINDINGS: The analysis of metabolic changes was performed using microarray analysis of liver tissue and NMR metabonomics of urine and liver tissue. Data were analyzed using multivariate statistics and Gene Ontology tools. The metabolic profiles characteristic for each of the two mutant groups and wild-type mice were identified with NMR metabonomics. We found decreased urinary levels of taurine, citrate and 2-oxoglutarate, and increased levels of trimethylamine, creatine and creatinine when compared to wild-type mice. These results indicate significant changes in lipid and choline metabolism, and were coupled with increased fat deposition, leading to obesity. The microarray analysis identified changes in expression of metabolic enzymes correlating with alterations in metabolite concentration both in urine and liver. Similarity of mutant 569 to the wild-type was seen in young mice, but the pattern of metabolites shifted to that of the 391 mutant as the 569 mice became obese after six months age. CONCLUSIONS/SIGNIFICANCE: The metabonomic observations were consistent with the parallel analysis of gene expression and pathway mapping using microarray data, identifying metabolites and gene transcripts involved in hepatic metabolism, especially for taurine, choline and creatinine metabolism. The systems biology approach applied in this study provides a coherent picture of metabolic changes resulting from impaired STAT5 signalling by the growth hormone

  11. Standardized, systemic phenotypic analysis of Slc12a1I299F mutant mice.

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    Kemter, Elisabeth; Rathkolb, Birgit; Becker, Lore; Bolle, Ines; Busch, Dirk H; Dalke, Claudia; Elvert, Ralf; Favor, Jack; Graw, Jochen; Hans, Wolfgang; Ivandic, Boris; Kalaydjiev, Svetoslav; Klopstock, Thomas; Rácz, Ildikó; Rozman, Jan; Schrewe, Anja; Schulz, Holger; Zimmer, Andreas; Fuchs, Helmut; Gailus-Durner, Valérie; Hrabe de Angelis, Martin; Wolf, Eckhard; Aigner, Bernhard

    2014-08-02

    Type I Bartter syndrome is a recessive human nephropathy caused by loss-of-function mutations in the SLC12A1 gene coding for the Na+-K+-2Cl- cotransporter NKCC2. We recently established the mutant mouse line Slc12a1I299F exhibiting kidney defects highly similar to the late-onset manifestation of this hereditary human disease. Besides the kidney defects, low blood pressure and osteopenia were revealed in the homozygous mutant mice which were also described in humans. Beside its strong expression in the kidney, NKCC2 has been also shown to be expressed in other tissues in rodents i.e. the gastrointestinal tract, pancreatic beta cells, and specific compartments of the ear, nasal tissue and eye. To examine if, besides kidney defects, further organ systems and/or metabolic pathways are affected by the Slc12a1I299F mutation as primary or secondary effects, we describe a standardized, systemic phenotypic analysis of the mutant mouse line Slc12a1I299F in the German Mouse Clinic. Slc12a1I299F homozygous mutant mice and Slc12a1I299F heterozygous mutant littermates as controls were tested at the age of 4-6 months. Beside the already published changes in blood pressure and bone metabolism, a significantly lower body weight and fat content were found as new phenotypes for Slc12a1I299F homozygous mutant mice. Small additional effects included a mild erythropenic anemia in homozygous mutant males as well as a slight hyperalgesia in homozygous mutant females. For other functions, such as immunology, lung function and neurology, no distinct alterations were observed. In this systemic analysis no clear primary effects of the Slc12a1I299F mutation appeared for the organs other than the kidneys where Slc12a1 expression has been described. On the other hand, long-term effects additional and/or secondary to the kidney lesions might also appear in humans harboring SLC12A1 mutations.

  12. Apc1-mediated antagonism of Wnt/beta-catenin signaling is required for retino-tectal pathfinding in the zebrafish.

    NARCIS (Netherlands)

    Paridaen, J.T.M.; Danesin, C.; Elas, A.T.; van de Water, S.G.P.; Houart, C.; Zivkovic, D.

    2009-01-01

    The tumor suppressor Apc1 is an intracellular antagonist of the Wnt/beta-catenin pathway. We examined the effects of an Apc1 loss-of-function mutation on retino-tectal axon pathfinding in zebrafish. In apc mutants, the retina is disorganized and optic nerves portray pathfinding defects at the optic

  13. Apc1-mediated antagonism of Wnt/beta-catenin signaling is required for retino-tectal pathfinding in the zebrafish.

    NARCIS (Netherlands)

    Paridaen, J.T.M.; Danesin, C.; Elas, A.T.; van de Water, S.G.P.; Houart, C.; Zivkovic, D.

    2009-01-01

    The tumor suppressor Apc1 is an intracellular antagonist of the Wnt/beta-catenin pathway. We examined the effects of an Apc1 loss-of-function mutation on retino-tectal axon pathfinding in zebrafish. In apc mutants, the retina is disorganized and optic nerves portray pathfinding defects at the optic

  14. Identification of Stk25 as a genetic modifier of Tau phosphorylation in Dab1-mutant mice.

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    Tohru Matsuki

    Full Text Available Hyperphosphorylation of the microtubule binding protein Tau is a feature of a number of neurodegenerative diseases, including Alzheimer's disease. Tau is hyperphosphorylated in the hippocampus of dab1-null mice in a strain-dependent manner; however, it has not been clear if the Tau phosphorylation phenotype is a secondary effect of the morbidity of these mutants. The dab1 gene encodes a docking protein that is required for normal brain lamination and dendritogenesis as part of the Reelin signaling pathway. We show that dab1 gene inactivation after brain development leads to Tau hyperphosphorylation in anatomically normal mice. Genomic regions that regulate the phospho Tau phenotype in dab1 mutants have previously been identified. Using a microarray gene expression comparison between dab1-mutants from the high-phospho Tau expressing and low-phospho Tau expressing strains, we identified Stk25 as a differentially expressed modifier of dab1-mutant phenotypes. Stk25 knockdown reduces Tau phosphorylation in embryonic neurons. Furthermore, Stk25 regulates neuronal polarization and Golgi morphology in an antagonistic manner to Dab1. This work provides insights into the complex regulation of neuronal behavior during brain development and provides insights into the molecular cascades that regulate Tau phosphorylation.

  15. Partial Müllerian Duct Retention in Smad4 Conditional Mutant Male Mice.

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    Petit, Fabrice G; Deng, Chuxia; Jamin, Soazik P

    2016-01-01

    Müllerian duct regression is a complex process which involves the AMH signalling pathway. We have previously demonstrated that besides AMH and its specific type II receptor (AMHRII), BMPR-IA and Smad5 are two essential factors implicated in this mechanism. Mothers against decapentaplegic homolog 4 (Smad4) is a transcription factor and the common Smad (co-Smad) involved in transforming growth factor beta (TGF-β) signalling pathway superfamily. Since Smad4 null mutants die early during gastrulation, we have inactivated Smad4 in the Müllerian duct mesenchyme. Specific inactivation of Smad4 in the urogenital ridge leads to the partial persistence of the Müllerian duct in adult male mice. Careful examination of the urogenital tract reveals that the Müllerian duct retention is randomly distributed either on one side or both sides. Histological analysis shows a uterus-like structure, which is confirmed by the expression of estrogen receptor α. As previously described in a β-catenin conditional mutant mouse model, β-catenin contributes to Müllerian duct regression. In our mutant male embryos, it appears that β-catenin expression is locally reduced along the urogenital ridge as compared to control mice. Moreover, the expression pattern is similar to those observed in control female mice. This study shows that reduced Smad4 expression disrupts the Wnt/β-catenin signalling leading to the partial persistence of Müllerian duct.

  16. A CA-repeat polymorphism close to the adenomatous polyposis coli (APC) gene offers improved diagnostic testing for familial APC

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    Spirio, L.; Nelson, L.; Ward, K.; Burt, R.; White, R.; Leppert, M. (Univ. of Utah, Salt Lake City (United States))

    1993-02-01

    Presymptomatic genetic testing for the presence of a mutant allele causing familial adenomatous polyposis coli (APC) has been difficult to perform effectively in the past because DNA markers surrounding the APC gene on chromosome 5q have not been very informative. The authors report results of genetic linkage studies on both research families and clinical families by using D5S346, a highly polymorphic dinucleotide (CA)-repeat locus 30-70 kb from the APC gene. Linkage analysis with this marker in a large APC pedigree showed an increase of at least 9.0 LOD units, in likelihood of linkage of the disease-causing allele to the APC locus, when compared with the highest LOD score attained with any other closely linked marker. When the first 14 APC families that requested genotypic analysis by the DNA Diagnostic Laboratory at the University of Utah were tested with D5S346, 20 of the 31 at-risk individuals were identified as either carriers or noncarriers of an APC-predisposing allele. The authors see this marker as an important tool for research studies and for the presymptomatic diagnosis of APC. 28 refs., 3 figs., 2 tabs.

  17. Progression of Hepatic Adenoma to Carcinoma in Ogg1 Mutant Mice Induced by Phenobarbital

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    Anna Kakehashi

    2017-01-01

    Full Text Available The carcinogenic potential of phenobarbital (PB was assessed in a mouse line carrying a mutant Mmh allele of the Mmh/Ogg1 gene encoding the enzyme oxoguanine DNA glycosylase (Ogg1 responsible for the repair of 8-hydroxy-2′-deoxyguanosine (8-OHdG. Mmh homozygous mutant (Ogg1−/− and wild-type (Ogg1+/+ male and female, 10-week-old, mice were treated with 500 ppm PB in diet for 78 weeks. Hepatocellular carcinomas (HCCs were found in PB-treated Ogg1−/− mice, while Ogg1+/+ animals developed only hepatocellular adenomas (HCAs at the same rate. This was coordinated with PB-induced significant elevation of 8-OHdG formation in DNA and cell proliferation in adjacent liver of Ogg1−/− mice. Proteome analysis predicted activation of transcriptional factor Nrf2 in the livers and HCAs of PB-administered Ogg1+/+ mice; however, its activation was insufficient or absent in the livers and HCCs of Ogg1−/− mice, respectively. Significant elevation of phase I and II metabolizing enzymes was demonstrated in both Ogg1−/− and Ogg1+/+ animals. Treatment of Ogg1−/− mice with PB resulted in significant elevation of cell proliferation in the liver. These results indicate that PB induced progression from HCA to HCC in Ogg1−/− mice, due to persistent accumulation of DNA oxidative base modifications and suppression of Nrf2-mediated oxidative stress response, resulting in significant elevation of cell proliferation.

  18. Conserved role of unc-79 in ethanol responses in lightweight mutant mice.

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    David J Speca

    2010-08-01

    Full Text Available The mechanisms by which ethanol and inhaled anesthetics influence the nervous system are poorly understood. Here we describe the positional cloning and characterization of a new mouse mutation isolated in an N-ethyl-N-nitrosourea (ENU forward mutagenesis screen for animals with enhanced locomotor activity. This allele, Lightweight (Lwt, disrupts the homolog of the Caenorhabditis elegans (C. elegans unc-79 gene. While Lwt/Lwt homozygotes are perinatal lethal, Lightweight heterozygotes are dramatically hypersensitive to acute ethanol exposure. Experiments in C. elegans demonstrate a conserved hypersensitivity to ethanol in unc-79 mutants and extend this observation to the related unc-80 mutant and nca-1;nca-2 double mutants. Lightweight heterozygotes also exhibit an altered response to the anesthetic isoflurane, reminiscent of unc-79 invertebrate mutant phenotypes. Consistent with our initial mapping results, Lightweight heterozygotes are mildly hyperactive when exposed to a novel environment and are smaller than wild-type animals. In addition, Lightweight heterozygotes exhibit increased food consumption yet have a leaner body composition. Interestingly, Lightweight heterozygotes voluntarily consume more ethanol than wild-type littermates. The acute hypersensitivity to and increased voluntary consumption of ethanol observed in Lightweight heterozygous mice in combination with the observed hypersensitivity to ethanol in C. elegans unc-79, unc-80, and nca-1;nca-2 double mutants suggests a novel conserved pathway that might influence alcohol-related behaviors in humans.

  19. Neurobehavioral performances and brain regional metabolism in Dab1(scm) (scrambler) mutant mice.

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    Jacquelin, C; Lalonde, R; Jantzen-Ossola, C; Strazielle, C

    2013-09-01

    As disabled-1 (DAB1) protein acts downstream in the reelin signaling pathway modulating neuronal migration, glutamate neurotransmission, and cytoskeletal function, the disabled-1 gene mutation (scrambler or Dab1(scm) mutation) results in ataxic mice displaying dramatic neuroanatomical defects similar to those observed in the reeler gene (Reln) mutation. By comparison to non-ataxic controls, Dab1(scm) mutants showed severe motor coordination impairments on stationary beam, coat-hanger, and rotorod tests but were more active in the open-field. Dab1(scm) mutants were also less anxious in the elevated plus-maze but with higher latencies in the emergence test. In mutants versus controls, changes in regional brain metabolism as measured by cytochrome oxidase (COX) activity occurred mainly in structures intimately connected with the cerebellum, in basal ganglia, in limbic regions, particularly hippocampus, as well as in visual and parietal sensory cortices. Although behavioral results characterized a major cerebellar disorder in the Dab1(scm) mutants, motor activity impairments in the open-field were associated with COX activity changes in efferent basal ganglia structures such as the substantia nigra, pars reticulata. Metabolic changes in this structure were also associated with the anxiety changes observed in the elevated plus-maze and emergence test. These results indicate a crucial participation of the basal ganglia in the functional phenotype of ataxic Dab1(scm) mutants.

  20. Deletion of Osr2 Partially Rescues Tooth Development in Runx2 Mutant Mice

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    Kwon, H.J.E.; Park, E.K.; Jia, S.; Liu, H.; Lan, Y.

    2015-01-01

    Tooth organogenesis depends on genetically programmed sequential and reciprocal inductive interactions between the dental epithelium and neural crest–derived mesenchyme. Previous studies showed that the Msx1 and Runx2 transcription factors are required for activation of odontogenic signals, including Bmp4 and Fgf3, in the early tooth mesenchyme to drive tooth morphogenesis through the bud-to-cap transition and that Runx2 acts downstream of Msx1 to activate Fgf3 expression. Recent studies identified Osr2 as a repressor of tooth development and showed that inactivation of Osr2 rescued molar tooth morphogenesis in the Msx1-/- mutant mice as well as in mice with neural crest–specific inactivation of Bmp4. Here we show that Runx2 expression is expanded in the tooth bud mesenchyme in Osr2-/- mutant mouse embryos and is partially restored in the tooth mesenchyme in Msx1-/-Osr2-/- mutants in comparison with Msx1-/- and wild-type embryos. Whereas mandibular molar development arrested at the bud stage and maxillary molar development arrested at the bud-to-cap transition in Runx2-/- mutant mice, both mandibular and maxillary molar tooth germs progressed to the early bell stage, with rescued expression of Msx1 and Bmp4 in the dental papilla as well as expression of Bmp4, p21, and Shh in the primary enamel knot in the Osr2-/-Runx2-/- compound mutants. In contrast to the Msx1-/-Osr2-/- compound mutants, which exhibit nearly normal first molar morphogenesis, the Osr2-/-Runx2-/- compound mutant embryos failed to activate the expression of Fgf3 and Fgf10 in the dental papilla and exhibited significant deficit in cell proliferation in both the dental epithelium and mesenchyme in comparison with the control embryos. These data indicate that Runx2 synergizes with Msx1 to drive tooth morphogenesis through the bud-to-cap transition and that Runx2 controls continued tooth growth and morphogenesis beyond the cap stage through activation of Fgf3 and Fgf10 expression in the dental

  1. Deletion of Osr2 Partially Rescues Tooth Development in Runx2 Mutant Mice.

    Science.gov (United States)

    Kwon, H J E; Park, E K; Jia, S; Liu, H; Lan, Y; Jiang, R

    2015-08-01

    Tooth organogenesis depends on genetically programmed sequential and reciprocal inductive interactions between the dental epithelium and neural crest-derived mesenchyme. Previous studies showed that the Msx1 and Runx2 transcription factors are required for activation of odontogenic signals, including Bmp4 and Fgf3, in the early tooth mesenchyme to drive tooth morphogenesis through the bud-to-cap transition and that Runx2 acts downstream of Msx1 to activate Fgf3 expression. Recent studies identified Osr2 as a repressor of tooth development and showed that inactivation of Osr2 rescued molar tooth morphogenesis in the Msx1(-/-) mutant mice as well as in mice with neural crest-specific inactivation of Bmp4. Here we show that Runx2 expression is expanded in the tooth bud mesenchyme in Osr2(-/-) mutant mouse embryos and is partially restored in the tooth mesenchyme in Msx1(-/-)Osr2(-/-) mutants in comparison with Msx1(-/-) and wild-type embryos. Whereas mandibular molar development arrested at the bud stage and maxillary molar development arrested at the bud-to-cap transition in Runx2(-/-) mutant mice, both mandibular and maxillary molar tooth germs progressed to the early bell stage, with rescued expression of Msx1 and Bmp4 in the dental papilla as well as expression of Bmp4, p21, and Shh in the primary enamel knot in the Osr2(-/-)Runx2(-/-) compound mutants. In contrast to the Msx1(-/-)Osr2(-/-) compound mutants, which exhibit nearly normal first molar morphogenesis, the Osr2(-/-)Runx2(-/-) compound mutant embryos failed to activate the expression of Fgf3 and Fgf10 in the dental papilla and exhibited significant deficit in cell proliferation in both the dental epithelium and mesenchyme in comparison with the control embryos. These data indicate that Runx2 synergizes with Msx1 to drive tooth morphogenesis through the bud-to-cap transition and that Runx2 controls continued tooth growth and morphogenesis beyond the cap stage through activation of Fgf3 and Fgf10 expression

  2. Shank3 mutant mice display autistic-like behaviours and striatal dysfunction.

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    Peça, João; Feliciano, Cátia; Ting, Jonathan T; Wang, Wenting; Wells, Michael F; Venkatraman, Talaignair N; Lascola, Christopher D; Fu, Zhanyan; Feng, Guoping

    2011-04-28

    Autism spectrum disorders (ASDs) comprise a range of disorders that share a core of neurobehavioural deficits characterized by widespread abnormalities in social interactions, deficits in communication as well as restricted interests and repetitive behaviours. The neurological basis and circuitry mechanisms underlying these abnormal behaviours are poorly understood. SHANK3 is a postsynaptic protein, whose disruption at the genetic level is thought to be responsible for the development of 22q13 deletion syndrome (Phelan-McDermid syndrome) and other non-syndromic ASDs. Here we show that mice with Shank3 gene deletions exhibit self-injurious repetitive grooming and deficits in social interaction. Cellular, electrophysiological and biochemical analyses uncovered defects at striatal synapses and cortico-striatal circuits in Shank3 mutant mice. Our findings demonstrate a critical role for SHANK3 in the normal development of neuronal connectivity and establish causality between a disruption in the Shank3 gene and the genesis of autistic-like behaviours in mice.

  3. Dearth and Delayed Maturation of Testicular Germ Cells in Fanconi Anemia E Mutant Male Mice

    Science.gov (United States)

    Fu, Chun; Begum, Khurshida; Jordan, Philip W.; He, Yan; Overbeek, Paul A.

    2016-01-01

    After using a self-inactivating lentivirus for non-targeted insertional mutagenesis in mice, we identified a transgenic family with a recessive mutation that resulted in reduced fertility in homozygous transgenic mice. The lentiviral integration site was amplified by inverse PCR. Sequencing revealed that integration had occurred in intron 8 of the mouse Fance gene, which encodes the Fanconi anemia E (Fance) protein. Fanconi anemia (FA) proteins play pivotal roles in cellular responses to DNA damage and Fance acts as a molecular bridge between the FA core complex and Fancd2. To investigate the reduced fertility in the mutant males, we analyzed postnatal development of testicular germ cells. At one week after birth, most tubules in the mutant testes contained few or no germ cells. Over the next 2–3 weeks, germ cells accumulated in a limited number of tubules, so that some tubules contained germ cells around the full periphery of the tubule. Once sufficient numbers of germ cells had accumulated, they began to undergo the later stages of spermatogenesis. Immunoassays revealed that the Fancd2 protein accumulated around the periphery of the nucleus in normal developing spermatocytes, but we did not detect a similar localization of Fancd2 in the Fance mutant testes. Our assays indicate that although Fance mutant males are germ cell deficient at birth, the extant germ cells can proliferate and, if they reach a threshold density, can differentiate into mature sperm. Analogous to previous studies of FA genes in mice, our results show that the Fance protein plays an important, but not absolutely essential, role in the initial developmental expansion of the male germ line. PMID:27486799

  4. Impact of Non-Invasively Induced Motor Deficits on Tibial Cortical Properties in Mutant Lurcher Mice.

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    Alena Jindrová

    Full Text Available It has been shown that Lurcher mutant mice have significantly altered motor abilities, regarding their motor coordination and muscular strength because of olivorecebellar degeneration. We assessed the response of the cross-sectional geometry and lacuno-canalicular network properties of the tibial mid-diaphyseal cortical bone to motor differences between Lurcher and wild-type (WT male mice from the B6CBA strain. The first data set used in the cross-sectional geometry analysis consists of 16 mice of 4 months of age and 32 mice of 9 months of age. The second data set used in the lacunar-canalicular network analysis consists of 10 mice of 4 months of age. We compared two cross-sectional geometry and four lacunar-canalicular properties by I-region using the maximum and minimum second moment of area and anatomical orientation as well as H-regions using histological differences within a cross section. We identified inconsistent differences in the studied cross-sectional geometry properties between Lurcher and WT mice. The biggest significant difference between Lurcher and WT mice is found in the number of canaliculi, whereas in the other studied properties are only limited. Lurcher mice exhibit an increased number of canaliculi (p < 0.01 in all studied regions compared with the WT controls. The number of canaliculi is also negatively correlated with the distance from the centroid in the Lurcher and positively correlated in the WT mice. When the Lurcher and WT sample is pooled, the number of canaliculi and lacunar volume is increased in the posterior Imax region, and in addition, midcortical H-region exhibit lower number of canaliculi, lacuna to lacuna distance and increased lacunar volume. Our results indicate, that the importance of precise sample selection within cross sections in future studies is highlighted because of the histological heterogeneity of lacunar-canalicular network properties within the I-region and H-region in the mouse cortical

  5. Regulation of the metabolite profile by an APC gene mutation in colorectal cancer.

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    Yoshie, Tomoo; Nishiumi, Shin; Izumi, Yoshihiro; Sakai, Aya; Inoue, Jun; Azuma, Takeshi; Yoshida, Masaru

    2012-06-01

    Mutation of the APC gene occurs during the early stages of colorectal cancer development. To obtain new insights into the mechanisms underlying the aberrant activation of the Wnt pathway that accompanies APC mutation, we carried out a gas chromatography-mass spectrometry-based semiquantitative metabolome analysis. In vitro experiments comparing SW480 cells expressing normal APC and truncated APC indicated that the levels of metabolites involved in the latter stages of the intracellular tricarboxylic acid cycle, including succinic acid, fumaric acid, and malic acid, were significantly higher in the SW480 cells expressing the truncated APC. In an in vivo study, we found that the levels of most amino acids were higher in the non-polyp tissues of APC(min/+) mice than in the normal tissues of the control mice and the polyp tissues of APC(min/+) mice. Ribitol, the levels of which were decreased in the polyp lesions of the APC(min/+) mice and the SW480 cells expressing the truncated APC, reduced the growth of SW480 cells with the APC mutation, but did not affect the growth of SW480 transfectants expressing full-length APC. The level of sarcosine was found to be significantly higher in the polyp tissues of APC(min/+) mice than in their non-polyp tissues and the normal tissues of the control mice, and the treatment of SW480 cells with 50 μM sarcosine resulted in a significant increase in their growth rate. These findings suggest that APC mutation causes changes in energetic metabolite pathways and that these alterations might be involved in the development of colorectal cancer.

  6. Silencing mutant ataxin-3 rescues motor deficits and neuropathology in Machado-Joseph disease transgenic mice.

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    Clévio Nóbrega

    Full Text Available Machado-Joseph disease (MJD or spinocerebellar ataxia type 3 (SCA3 is an autosomal dominantly-inherited neurodegenerative disorder caused by the over-repetition of a CAG codon in the MJD1 gene. This expansion translates into a polyglutamine tract that confers a toxic gain-of-function to the mutant protein--ataxin-3, leading to neurodegeneration in specific brain regions, with particular severity in the cerebellum. No treatment able to modify the disease progression is available. However, gene silencing by RNA interference has shown promising results. Therefore, in this study we investigated whether lentiviral-mediated allele-specific silencing of the mutant ataxin-3 gene, after disease onset, would rescue the motor behavior deficits and neuropathological features in a severely impaired transgenic mouse model of MJD. For this purpose, we injected lentiviral vectors encoding allele-specific silencing-sequences (shAtx3 into the cerebellum of diseased transgenic mice expressing the targeted C-variant of mutant ataxin-3 present in 70% of MJD patients. This variation permits to discriminate between the wild-type and mutant forms, maintaining the normal function of the wild-type allele and silencing only the mutant form. Quantitative analysis of rotarod performance, footprint and activity patterns revealed significant and robust alleviation of gait, balance (average 3-fold increase of rotarod test time, locomotor and exploratory activity impairments in shAtx3-injected mice, as compared to control ones injected with shGFP. An important improvement of neuropathology was also observed, regarding the number of intranuclear inclusions, calbindin and DARPP-32 immunoreactivity, fluorojade B and Golgi staining and molecular and granular layers thickness. These data demonstrate for the first time the efficacy of gene silencing in blocking the MJD-associated motor-behavior and neuropathological abnormalities after the onset of the disease, supporting the use of

  7. Characterisation of prostate cancer lesions in heterozygous Men1 mutant mice

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    Tong Wei-Ming

    2010-07-01

    Full Text Available Abstract Background Mutations of the MEN1 gene predispose to multiple endocrine neoplasia type 1 (MEN1 syndrome. Our group and others have shown that Men1 disruption in mice recapitulates MEN1 pathology. Intriguingly, rare lesions in hormone-dependent tissues, such as prostate and mammary glands, were also observed in the Men1 mutant mice. Methods To study the occurrence of prostate lesions, we followed a male mouse cohort of 47 Men1+/- mice and 23 age-matched control littermates, starting at 18 months of age, and analysed the prostate glands from the cohort. Results Six Men1+/- mice (12.8% developed prostate cancer, including two adenocarcinomas and four in situ carcinomas, while none of the control mice developed cancerous lesions. The expression of menin encoded by the Men1 gene was found to be drastically reduced in all carcinomas, and partial LOH of the wild-type Men1 allele was detected in three of the five analysed lesions. Using immunostaining for the androgen receptor and p63, a basal epithelial cell marker, we demonstrated that the menin-negative prostate cancer cells did not display p63 expression and that the androgen receptor was expressed but more heterogeneous in these lesions. Furthermore, our data showed that the expression of the cyclin-dependent kinase inhibitor CDKN1B (p27, a Men1 target gene known to be inactivated during prostate cell tumorigenesis, was notably decreased in the prostate cancers that developed in the mutant mice. Conclusion Our work suggests the possible involvement of Men1 inactivation in the tumorigenesis of the prostate gland.

  8. Characterization of neonatal vocal and motor repertoire of reelin mutant mice.

    Science.gov (United States)

    Romano, Emilia; Michetti, Caterina; Caruso, Angela; Laviola, Giovanni; Scattoni, Maria Luisa

    2013-01-01

    Reelin is a large secreted extracellular matrix glycoprotein playing an important role in early neurodevelopment. Several genetic studies found an association between RELN gene and increased risk of autism suggesting that reelin deficiency may be a vulnerability factor in its etiology. Moreover, a reduced reelin expression has been observed in several brain regions of subjects with Autism Spectrum Disorders. Since a number of reports have documented presence of vocal and neuromotor abnormalities in patients with autism and suggested that these dysfunctions predate the onset of the syndrome, we performed a fine-grain characterization of the neonatal vocal and motor repertoire in reelin mutant mice to explore the developmental precursors of the disorder. Our findings evidence a general delay in motor and vocal development in heterozygous (50% reduced reelin) and reeler (lacking reelin gene) mutant mice. As a whole, an increased number of calls characterized heterozygous pup's emission. Furthermore, the typical ontogenetic peak in the number of calls characterizing wild-type pups on postnatal day 4 appeared slightly delayed in heterozygous pups (to day 6) and was quite absent in reeler littermates, which exhibited a flat profile during development. We also detected a preferential use of a specific call category (two-components) by heterozygous and reeler mice at postnatal days 6 and 8 as compared to their wild-type littermates. With regard to the analysis of spontaneous movements, a differential profile emerged early in development among the three genotypes. While only slight coordination difficulties are exhibited by heterozygous pups, all indices of motor development appear delayed in reeler mice. Overall, our results evidence a genotype-dependent deviation in ultrasonic vocal repertoire and a general delay in motor development in reelin mutant pups.

  9. Characterization of neonatal vocal and motor repertoire of reelin mutant mice.

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    Emilia Romano

    Full Text Available Reelin is a large secreted extracellular matrix glycoprotein playing an important role in early neurodevelopment. Several genetic studies found an association between RELN gene and increased risk of autism suggesting that reelin deficiency may be a vulnerability factor in its etiology. Moreover, a reduced reelin expression has been observed in several brain regions of subjects with Autism Spectrum Disorders. Since a number of reports have documented presence of vocal and neuromotor abnormalities in patients with autism and suggested that these dysfunctions predate the onset of the syndrome, we performed a fine-grain characterization of the neonatal vocal and motor repertoire in reelin mutant mice to explore the developmental precursors of the disorder. Our findings evidence a general delay in motor and vocal development in heterozygous (50% reduced reelin and reeler (lacking reelin gene mutant mice. As a whole, an increased number of calls characterized heterozygous pup's emission. Furthermore, the typical ontogenetic peak in the number of calls characterizing wild-type pups on postnatal day 4 appeared slightly delayed in heterozygous pups (to day 6 and was quite absent in reeler littermates, which exhibited a flat profile during development. We also detected a preferential use of a specific call category (two-components by heterozygous and reeler mice at postnatal days 6 and 8 as compared to their wild-type littermates. With regard to the analysis of spontaneous movements, a differential profile emerged early in development among the three genotypes. While only slight coordination difficulties are exhibited by heterozygous pups, all indices of motor development appear delayed in reeler mice. Overall, our results evidence a genotype-dependent deviation in ultrasonic vocal repertoire and a general delay in motor development in reelin mutant pups.

  10. Four kinds of ENU-induced white spot mice and chromosome locations of the mutant genes

    Institute of Scientific and Technical Information of China (English)

    WU Baojin; MAO Huihua; SHAO Yixiang; XUE Zhengfeng; LI Houda

    2003-01-01

    Phenotype-driven is the name for an approach used to study gene functions through mutagenesis, location and cloning of the mutant gene. In this study, 150 male C57BL/6J(B6) mice were treated with ENU and reproduced a total offspring of 3860. Of these descendants, 210 exhibited mutation phenotypes by screening, and more than 10 of them are hereditable. Four kinds of mutant mice, named Wbct, W-1Bao, W-2Bao, and W-3Bao, showed dominant hereditary white spot mutation with partial albinism on their belly, distal limbs and tail terminal. To map these mutant genes, 39 microsatellites, equally distributed on the mouse genome and with difference between B6 and DBA/2J (D2), were selected to scan the genome after discrimination of the white spots in the F2 mice [(B6×D2)×D2]. It is found that, the log odds score (LODS) between W-1Bao and D5Mit168 is 0.56, and the LODS of W-1Bao and D5Mit352 is 4.47. With the gradual application of microsatellites D5Mit290, D5Mit312, D5Mit308 and D5Mit356 that are close to the mutant gene, and the number of F2 mice going up to 537, the mutant W-1Bao is located between D5Mit356 and D5Mit308 on chromosome 5, about 42.19 cM from the centromere. In the same way, W-2Bao and W-3Bao are mapped nearby W-1Bao, and Wbct is located on chromosome 1, about 41.6 cM from the centromere. After searching for the mouse genome database (MGD) and performing a one-by-one study of all genes located on chromosome subregion, it is believed that the kit gene is an excellent candidate for the white spot mutations of W-1Bao, W-2Bao and W-3Bao.

  11. Dual PI3K/mTOR Inhibition in Colorectal Cancers with APC and PIK3CA Mutations.

    Science.gov (United States)

    Foley, Tyler M; Payne, Susan N; Pasch, Cheri A; Yueh, Alex E; Van De Hey, Dana R; Korkos, Demetra P; Clipson, Linda; Maher, Molly E; Matkowskyj, Kristina A; Newton, Michael A; Deming, Dustin A

    2017-02-09

    Therapeutic targeting of the PI3K pathway is an active area of research in multiple cancer types, including breast and endometrial cancers. This pathway is commonly altered in cancer and plays an integral role in numerous vital cellular functions. Mutations in the PIK3CA gene, resulting in a constitutively active form of PI3K, often occur in colorectal cancer, though the population of patients who would benefit from targeting this pathway has yet to be identified. In human colorectal cancers, PIK3CA mutations most commonly occur concomitantly with loss of adenomatous polyposis coli (APC). Here, treatment strategies are investigated that target the PI3K pathway in colon cancers with mutations in APC and PIK3CA Colorectal cancer spheroids with Apc and Pik3ca mutations were generated and characterized confirming that these cultures represent the tumors from which they were derived. Pan and alpha isomer-specific PI3K inhibitors did not induce a significant treatment response, whereas the dual PI3K/mTOR inhibitors BEZ235 and LY3023414 induced a dramatic treatment response through decreased cellular proliferation and increased differentiation. The significant treatment responses were confirmed in mice with Apc and Pik3ca-mutant colon cancers as measured using endoscopy with a reduction in median lumen occlusion of 53% with BEZ235 and a 24% reduction with LY3023414 compared with an increase of 53% in controls (P APC and PIK3CA-mutant colorectal cancers. Thus, further clinical studies of dual PI3K/mTOR inhibitors are warranted in colorectal cancers with these mutations. Mol Cancer Res; 15(3); 1-11. ©2016 AACR.

  12. Generation and Standardized, Systemic Phenotypic Analysis of Pou3f3L423P Mutant Mice.

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    Sudhir Kumar

    Full Text Available Increased levels of blood plasma urea were used as phenotypic parameter for establishing novel mouse models for kidney diseases on the genetic background of C3H inbred mice in the phenotype-driven Munich ENU mouse mutagenesis project. The phenotypically recessive mutant line HST011 was established and further analyzed. The causative mutation was detected in the POU domain, class 3 transcription factor 3 (Pou3f3 gene, which leads to the amino acid exchange Pou3f3L423P thereby affecting the conserved homeobox domain of the protein. Pou3f3 homozygous knockout mice are published and show perinatal death. Line Pou3f3L423P is a viable mouse model harboring a homozygous Pou3f3 mutation. Standardized, systemic phenotypic analysis of homozygous mutants was carried out in the German Mouse Clinic. Main phenotypic changes were low body weight and a state of low energy stores, kidney dysfunction and secondary effects thereof including low bone mineralization, multiple behavioral and neurological defects including locomotor, vestibular, auditory and nociceptive impairments, as well as multiple subtle changes in immunological parameters. Genome-wide transcriptome profiling analysis of kidney and brain of Pou3f3L423P homozygous mutants identified significantly regulated genes as compared to wild-type controls.

  13. Neurologic function during developmental and adult stages in Dab1(scm) (scrambler) mutant mice.

    Science.gov (United States)

    Jacquelin, C; Strazielle, C; Lalonde, R

    2012-01-01

    Homozygous Dab1(scm) mouse mutants with cell ectopias in cerebellar cortex, hippocampus, and neocortex were compared to non-ataxic controls on the SHIRPA primary screening battery on postnatal days 8, 15, and 22, as well as in the adult period. Dab1(scm) mutants were distinguished from non-ataxic controls as early as postnatal day 8 based on body tremor, gait anomalies, and body weight. On postnatal day 15, motor coordination deficits were evident on horizontal bar and inclined or vertical grid tests in association with a weaker grip strength. Likewise, mutants were distinguished from controls on drop righting and hindpaw clasping tests. Further differences were detected on postnatal day 22 in the form of fewer visual placing, touch escape, trunk curl, freezing, and vocalization responses, as well as squares traversed in the open-field. Evaluation at the adult age demonstrated similar impairments, indicative of permanent motor alterations. Neuronal metabolic activity was estimated by cytochrome oxidase histochemistry on cerebellar sections. Cerebellar cortical layers and efferent deep nuclei of Dab1(scm) mice appeared hypometabolic relative to non-ataxic mice despite normal metabolism in both regular and ectopic Purkinje cells.

  14. Generation and Standardized, Systemic Phenotypic Analysis of Pou3f3L423P Mutant Mice.

    Science.gov (United States)

    Kumar, Sudhir; Rathkolb, Birgit; Kemter, Elisabeth; Sabrautzki, Sibylle; Michel, Dian; Adler, Thure; Becker, Lore; Beckers, Johannes; Busch, Dirk H; Garrett, Lillian; Hans, Wolfgang; Hölter, Sabine M; Horsch, Marion; Klingenspor, Martin; Klopstock, Thomas; Rácz, Ildikó; Rozman, Jan; Vargas Panesso, Ingrid Liliana; Vernaleken, Alexandra; Zimmer, Andreas; Fuchs, Helmut; Gailus-Durner, Valérie; Hrabě de Angelis, Martin; Wolf, Eckhard; Aigner, Bernhard

    2016-01-01

    Increased levels of blood plasma urea were used as phenotypic parameter for establishing novel mouse models for kidney diseases on the genetic background of C3H inbred mice in the phenotype-driven Munich ENU mouse mutagenesis project. The phenotypically recessive mutant line HST011 was established and further analyzed. The causative mutation was detected in the POU domain, class 3 transcription factor 3 (Pou3f3) gene, which leads to the amino acid exchange Pou3f3L423P thereby affecting the conserved homeobox domain of the protein. Pou3f3 homozygous knockout mice are published and show perinatal death. Line Pou3f3L423P is a viable mouse model harboring a homozygous Pou3f3 mutation. Standardized, systemic phenotypic analysis of homozygous mutants was carried out in the German Mouse Clinic. Main phenotypic changes were low body weight and a state of low energy stores, kidney dysfunction and secondary effects thereof including low bone mineralization, multiple behavioral and neurological defects including locomotor, vestibular, auditory and nociceptive impairments, as well as multiple subtle changes in immunological parameters. Genome-wide transcriptome profiling analysis of kidney and brain of Pou3f3L423P homozygous mutants identified significantly regulated genes as compared to wild-type controls.

  15. Modeled changes of cerebellar activity in mutant mice are predictive of their learning impairments

    Science.gov (United States)

    Badura, Aleksandra; Clopath, Claudia; Schonewille, Martijn; de Zeeuw, Chris I.

    2016-11-01

    Translating neuronal activity to measurable behavioral changes has been a long-standing goal of systems neuroscience. Recently, we have developed a model of phase-reversal learning of the vestibulo-ocular reflex, a well-established, cerebellar-dependent task. The model, comprising both the cerebellar cortex and vestibular nuclei, reproduces behavioral data and accounts for the changes in neural activity during learning in wild type mice. Here, we used our model to predict Purkinje cell spiking as well as behavior before and after learning of five different lines of mutant mice with distinct cell-specific alterations of the cerebellar cortical circuitry. We tested these predictions by obtaining electrophysiological data depicting changes in neuronal spiking. We show that our data is largely consistent with the model predictions for simple spike modulation of Purkinje cells and concomitant behavioral learning in four of the mutants. In addition, our model accurately predicts a shift in simple spike activity in a mutant mouse with a brainstem specific mutation. This combination of electrophysiological and computational techniques opens a possibility of predicting behavioral impairments from neural activity.

  16. Bacteriophage-resistant mutants in Yersinia pestis: identification of phage receptors and attenuation for mice.

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    Andrey A Filippov

    Full Text Available BACKGROUND: Bacteriophages specific for Yersinia pestis are routinely used for plague diagnostics and could be an alternative to antibiotics in case of drug-resistant plague. A major concern of bacteriophage therapy is the emergence of phage-resistant mutants. The use of phage cocktails can overcome this problem but only if the phages exploit different receptors. Some phage-resistant mutants lose virulence and therefore should not complicate bacteriophage therapy. METHODOLOGY/PRINCIPAL FINDINGS: The purpose of this work was to identify Y. pestis phage receptors using site-directed mutagenesis and trans-complementation and to determine potential attenuation of phage-resistant mutants for mice. Six receptors for eight phages were found in different parts of the lipopolysaccharide (LPS inner and outer core. The receptor for R phage was localized beyond the LPS core. Most spontaneous and defined phage-resistant mutants of Y. pestis were attenuated, showing increase in LD₅₀ and time to death. The loss of different LPS core biosynthesis enzymes resulted in the reduction of Y. pestis virulence and there was a correlation between the degree of core truncation and the impact on virulence. The yrbH and waaA mutants completely lost their virulence. CONCLUSIONS/SIGNIFICANCE: We identified Y. pestis receptors for eight bacteriophages. Nine phages together use at least seven different Y. pestis receptors that makes some of them promising for formulation of plague therapeutic cocktails. Most phage-resistant Y. pestis mutants become attenuated and thus should not pose a serious problem for bacteriophage therapy of plague. LPS is a critical virulence factor of Y. pestis.

  17. Otx1 null mutant mice show partial segregation of sensory epithelia comparable to lamprey ears

    Science.gov (United States)

    Fritzsch, B.; Signore, M.; Simeone, A.

    2001-01-01

    We investigated the development of inner ear innervation in Otx1 null mutants, which lack a horizontal canal, between embryonic day 12 (E12) and postnatal day 7 (P7) with DiI and immunostaining for acetylated tubulin. Comparable to control animals, horizontal crista-like fibers were found to cross over the utricle in Otx1 null mice. In mutants these fibers extend toward an area near the endolymphatic duct, not to a horizontal crista. Most Otx1 null mutants had a small patch of sensory hair cells at this position. Measurement of the area of the utricular macula suggested it to be enlarged in Otx1 null mutants. We suggest that parts of the horizontal canal crista remain incorporated in the utricular sensory epithelium in Otx1 null mutants. Other parts of the horizontal crista appear to be variably segregated to form the isolated patch of hair cells identifiable by the unique fiber trajectory as representing the horizontal canal crista. Comparison with lamprey ear innervation reveals similarities in the pattern of innervation with the dorsal macula, a sensory patch of unknown function. SEM data confirm that all foramina are less constricted in Otx1 null mutants. We propose that Otx1 is not directly involved in sensory hair cell formation of the horizontal canal but affects the segregation of the horizontal canal crista from the utricle. It also affects constriction of the two main foramina in the ear, but not their initial formation. Otx1 is thus causally related to horizontal canal morphogenesis as well as morphogenesis of these foramina.

  18. Mutant mice lacking acetyl-CoA carboxylase 1 are embryonically lethal

    Science.gov (United States)

    Abu-Elheiga, Lutfi; Matzuk, Martin M.; Kordari, Parichher; Oh, WonKeun; Shaikenov, Tattym; Gu, Ziwei; Wakil, Salih J.

    2005-01-01

    Acetyl-CoA carboxylases (ACC1 and ACC2) catalyze the carboxylation of acetyl-CoA to form malonyl-CoA, an intermediate metabolite that plays a pivotal role in the regulation of fatty acid metabolism. We previously reported that ACC2 null mice are viable, and that ACC2 plays an important role in the regulation of fatty acid oxidation through the inhibition of carnitine palmitoyltransferase I, a mitochondrial component of the fatty-acyl shuttle system. Herein, we used gene targeting to knock out the ACC1 gene. The heterozygous mutant mice (Acc1+/–) had normal fertility and lifespans and maintained a similar body weight to that of their wild-type cohorts. The mRNA level of ACC1 in the tissues of Acc1+/– mice was half that of the wild type; however, the protein level of ACC1 and the total malonyl-CoA level were similar. In addition, there was no difference in the acetate incorporation into fatty acids nor in the fatty acid oxidation between the hepatocytes of Acc1+/– mice and those of the wild type. In contrast to Acc2–/– mice, Acc1–/– mice were not detected after mating. Timed pregnancies of heterozygotes revealed that Acc–/– embryos are already undeveloped at embryonic day (E)7.5, they die by E8.5, and are completely resorbed at E11.5. Our previous results of the ACC2 knockout mice and current studies of ACC1 knockout mice further confirm our hypotheses that malonyl-CoA exists in two independent pools, and that ACC1 and ACC2 have distinct roles in fatty acid metabolism. PMID:16103361

  19. Comprehensive behavioral analysis of ENU-induced Disc1-Q31L and -L100P mutant mice

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    Shoji Hirotaka

    2012-02-01

    Full Text Available Abstract Background Disrupted-in-Schizophrenia 1 (DISC1 is considered to be a candidate susceptibility gene for psychiatric disorders, including schizophrenia, bipolar disorder, and major depression. A recent study reported that N-ethyl-N-nitrosourea (ENU-induced mutations in exon 2 of the mouse Disc1 gene, which resulted in the amino acid exchange of Q31L and L100P, caused an increase in depression-like behavior in 31 L mutant mice and schizophrenia-like behavior in 100P mutant mice; thus, these are potential animal models of psychiatric disorders. However, remaining heterozygous mutations that possibly occur in flanking genes other than Disc1 itself might induce behavioral abnormalities in the mutant mice. Here, to confirm the effects of Disc1-Q31L and Disc1-L100P mutations on behavioral phenotypes and to investigate the behaviors of the mutant mice in more detail, the mutant lines were backcrossed to C57BL/6JJcl through an additional two generations and the behaviors were analyzed using a comprehensive behavioral test battery. Results Contrary to expectations, 31 L mutant mice showed no significant behavioral differences when compared with wild-type control mice in any of the behavioral tests, including the Porsolt forced swim and tail suspension tests, commonly used tests for depression-like behavior. Also, 100P mutant mice exhibited no differences in almost all of the behavioral tests, including the prepulse inhibition test for measuring sensorimotor gating, which is known to be impaired in schizophrenia patients; however, 100P mutant mice showed higher locomotor activity compared with wild-type control mice in the light/dark transition test. Conclusions Although these results are partially consistent with the previous study in that there was hyperactivity in 100P mutant mice, the vast majority of the results are inconsistent with those of the previous study; this discrepancy may be explained by differences in the genetic background of the

  20. Comprehensive behavioral analysis of ENU-induced Disc1-Q31L and -L100P mutant mice.

    Science.gov (United States)

    Shoji, Hirotaka; Toyama, Keiko; Takamiya, Yoshihiro; Wakana, Shigeharu; Gondo, Yoichi; Miyakawa, Tsuyoshi

    2012-02-20

    Disrupted-in-Schizophrenia 1 (DISC1) is considered to be a candidate susceptibility gene for psychiatric disorders, including schizophrenia, bipolar disorder, and major depression. A recent study reported that N-ethyl-N-nitrosourea (ENU)-induced mutations in exon 2 of the mouse Disc1 gene, which resulted in the amino acid exchange of Q31L and L100P, caused an increase in depression-like behavior in 31 L mutant mice and schizophrenia-like behavior in 100P mutant mice; thus, these are potential animal models of psychiatric disorders. However, remaining heterozygous mutations that possibly occur in flanking genes other than Disc1 itself might induce behavioral abnormalities in the mutant mice. Here, to confirm the effects of Disc1-Q31L and Disc1-L100P mutations on behavioral phenotypes and to investigate the behaviors of the mutant mice in more detail, the mutant lines were backcrossed to C57BL/6JJcl through an additional two generations and the behaviors were analyzed using a comprehensive behavioral test battery. Contrary to expectations, 31 L mutant mice showed no significant behavioral differences when compared with wild-type control mice in any of the behavioral tests, including the Porsolt forced swim and tail suspension tests, commonly used tests for depression-like behavior. Also, 100P mutant mice exhibited no differences in almost all of the behavioral tests, including the prepulse inhibition test for measuring sensorimotor gating, which is known to be impaired in schizophrenia patients; however, 100P mutant mice showed higher locomotor activity compared with wild-type control mice in the light/dark transition test. Although these results are partially consistent with the previous study in that there was hyperactivity in 100P mutant mice, the vast majority of the results are inconsistent with those of the previous study; this discrepancy may be explained by differences in the genetic background of the mice, the laboratory environment, experimental protocols

  1. Metabolic abnormalities and hypoleptinemia in α-synuclein A53T mutant mice.

    Science.gov (United States)

    Rothman, Sarah M; Griffioen, Kathleen J; Fishbein, Kenneth W; Spencer, Richard G; Makrogiannis, Sokratis; Cong, Wei-Na; Martin, Bronwen; Mattson, Mark P

    2014-05-01

    Parkinson's disease (PD) patients frequently display loss of body fat mass and increased energy expenditure, and several studies have outlined a relationship between these metabolic abnormalities and disease severity, yet energy metabolism is largely unstudied in mouse models of PD. Here we characterize metabolic and physiologic responses to a high calorie diet (HCD) in mice expressing in neurons a mutant form of human α-synuclein (A53T) that causes dominantly inherited familial forms of the disease. A53T (SNCA) and wild type (WT) littermate mice were placed on a HCD for 12 weeks and evaluated for weight gain, food intake, body fat, blood plasma leptin, hunger, glucose tolerance, and energy expenditure. Results were compared with both SNCA and WT mice on a control diet. Despite consuming similar amounts of food, WT mice gained up to 66% of their original body weight on a HCD, whereas SNCA mice gained only 17%. Further, after 12 weeks on a HCD, magnetic resonance imaging analysis revealed that WT mice had significantly greater total and visceral body fat compared with SNCA mice (p < 0.007). At the age of 24 weeks SNCA mice displayed significantly increased hunger compared with WT (p < 0.03). At the age of 36 weeks, SNCA mice displayed significant hypoleptinemia compared with WT, both on a normal diet and a HCD (p < 0.03). The HCD induced insulin insensitivity in WT, but not SNCA mice, as indicated by an oral glucose tolerance test. Finally, SNCA mice displayed greater energy expenditure compared with WT, as measured in a Comprehensive Laboratory Animal Monitoring System, after 12 weeks on a HCD. Thus, SNCA mice are resistant to HCD-induced obesity and insulin resistance and display reduced body fat, increased hunger, hypoleptinemia and increased energy expenditure. Our findings reveal a profile of metabolic dysfunction in a mouse model of PD that is similar to that of human PD patients, thus providing evidence that α-synuclein pathology is sufficient to drive such

  2. Degenerative hairlets on the vestibular sensory cells in mutant bustling (BUS/Idr) mice.

    Science.gov (United States)

    Moriyama, K; Hashimoto, R; Hanai, A; Yoshizaki, N; Yonezawa, S; Otani, H

    1997-01-01

    The bustling mouse (BUS/Idr: bus) is a mutant mouse strain which exhibits deafness, bustling/hyperkinetic behaviour and functional disorders seemingly related to the vestibular system. This phenotype develops in homozygous (bus/bus) mice and has been shown from cross experiments to be genetically induced by a single autosomal recessive gene. We previously detected, with light and electron microscopy, post-natal degeneration of the inner ear sensory cells in homozygotes. In the present study, we examined, by electron microscopy, the development of pathological changes in the sensory epithelia of the macula acustica and crista ampullaris of homozygous mice of various ages, paying special attention to the detailed morphology of the sensory hairlets. The homozygous mice exhibited specific pathological changes: a decrease in the number of hairs; disarrangement of the kinocilium-stereocilia pattern; and, fused and/or very large stereocilia. Homozygotes also frequently exhibited apical cytoplasmic herniation, or bleb of hair cells, as well as a degenerated kinocilium in the sensory epithelium. Heterozygotes showed similar changes, but to a lesser degree and frequency. As for the vestibular organs, similar pathological changes had developed at day, 17 of gestation. These pathological findings and onset suggest that the BUS mouse may be a mutant mouse strain distinct from other reported strains which display similar behaviour, and may be a useful animal model for the study of human degenerative vestibular disorders.

  3. Mutant Enpp1asj mice as a model for generalized arterial calcification of infancy

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    Qiaoli Li

    2013-09-01

    Generalized arterial calcification of infancy (GACI, an autosomal recessive disorder, is characterized by early mineralization of blood vessels, often diagnosed by prenatal ultrasound and usually resulting in demise during the first year of life. It is caused in most cases by mutations in the ENPP1 gene, encoding an enzyme that hydrolyzes ATP to AMP and inorganic pyrophosphate, the latter being a powerful anti-mineralization factor. Recently, a novel mouse phenotype was recognized as a result of ENU mutagenesis – those mice developed stiffening of the joints, hence the mutant mouse was named ‘ages with stiffened joints’ (asj. These mice harbor a missense mutation, p.V246D, in the Enpp1 gene. Here we demonstrate that the mutant ENPP1 protein is largely absent in the liver of asj mice, and the lack of enzymatic activity results in reduced inorganic pyrophosphate (PPi levels in the plasma, accompanied by extensive mineralization of a number of tissues, including arterial blood vessels. The progress of mineralization is highly dependent on the mineral composition of the diet, with significant shortening of the lifespan on a diet enriched in phosphorus and low in magnesium. These results suggest that the asj mouse can serve as an animal model for GACI.

  4. Evaluation of Rett Syndrome Symptom Improvement by Metabolic Modulators in Mecp2-Mutant Mice.

    Science.gov (United States)

    Buchovecky, Christie M; Hill, Misty G; Borkey, Jennifer M; Kyle, Stephanie M; Justice, Monica J

    2013-12-19

    Mouse models recapitulate many symptoms of Rett Syndrome, an X-linked disorder caused by mutations in methyl-CpG-binding protein 2 (MECP2). The study of Mecp2-null male mice has provided insight into pathogenesis of the disorder-most recently, dysregulation of cholesterol and lipid metabolism. Perisymptomatic treatment with statin drugs successfully mitigates the effects of this metabolic syndrome, increases longevity, and improves motor function. Described here is a metabolic drug screening protocol and timeline for symptom evaluation in Mecp2-mutant mice. Specifically, mice are treated twice weekly with a compound of interest alongside subjective health assessments, bi-weekly body composition measurements, and blood chemistries. Throughout treatment, behavioral phenotyping tests are carried out at specific time points. This protocol is highly adaptable to other neurological diseases; however, the time for completion depends on the specific mutant model under study. The protocol highlights the use of techniques described in several different Current Protocols in Mouse Biology articles to carry out testing in a preclinical model. Curr. Protoc. Mouse Biol. 3:187-204 © 2013 by John Wiley & Sons, Inc.

  5. [The effect of the mutant genes Ta, Ra and Sd on early embryogenesis in mice].

    Science.gov (United States)

    Sakharova, N Iu; Malashenko, A M; Mezhevikina, L M; Lepikhov, K A; Fialkovskaia, L A

    1996-01-01

    We studied early embryonic mortality of mice from mutant stocks Tabby (Ta, X-chromosome) and RaSd (RaSd/++, chromosome 2) maintained in the heterozygous state in F1 CBA x C57B1/6 hybrid. Tabby and RaSd mice were reciprocally crossed with F1 mice and examined for the morphological status of embryos washed from the oviduct on the third day of pregnancy, when the stage of eight blastomeres is normally attained. Mortality was evaluated from the number of embryos which did not reach the expected stage by this time. The results have shown that 2-4 cell embryos, which have received gene Ta with the X-chromosome of the female parent, differed from embryos with F1 genotype at the same stage of development by their increased mortality rate, whereas among embryos obtained from RaSd, the mortality was mainly observed before cleavage. Death of embryos receiving the mutant gene from hemizygous Ta males or heterozygous RaSd/++ males was not significantly different from the mortality of embryos without these mutations.

  6. Mutant Enpp1asj mice as a model for generalized arterial calcification of infancy.

    Science.gov (United States)

    Li, Qiaoli; Guo, Haitao; Chou, David W; Berndt, Annerose; Sundberg, John P; Uitto, Jouni

    2013-09-01

    Generalized arterial calcification of infancy (GACI), an autosomal recessive disorder, is characterized by early mineralization of blood vessels, often diagnosed by prenatal ultrasound and usually resulting in demise during the first year of life. It is caused in most cases by mutations in the ENPP1 gene, encoding an enzyme that hydrolyzes ATP to AMP and inorganic pyrophosphate, the latter being a powerful anti-mineralization factor. Recently, a novel mouse phenotype was recognized as a result of ENU mutagenesis - those mice developed stiffening of the joints, hence the mutant mouse was named 'ages with stiffened joints' (asj). These mice harbor a missense mutation, p.V246D, in the Enpp1 gene. Here we demonstrate that the mutant ENPP1 protein is largely absent in the liver of asj mice, and the lack of enzymatic activity results in reduced inorganic pyrophosphate (PPi) levels in the plasma, accompanied by extensive mineralization of a number of tissues, including arterial blood vessels. The progress of mineralization is highly dependent on the mineral composition of the diet, with significant shortening of the lifespan on a diet enriched in phosphorus and low in magnesium. These results suggest that the asj mouse can serve as an animal model for GACI.

  7. Assessment of behaviors modeling aspects of schizophrenia in Csmd1 mutant mice.

    Directory of Open Access Journals (Sweden)

    Margaret G Distler

    Full Text Available Schizophrenia is a debilitating psychotic disorder that affects up to 1.5% of the population worldwide. Two recent studies in humans identified genome-wide significant associations between schizophrenia and single-nucleotide polymorphisms (SNPs in an intron of CSMD1. The effect of deleting CSMD1 on mouse behavior is unknown. The present study utilized mice with a mutant Csmd1 allele in which the first exon had been ablated (KO mice. All Csmd1 transcripts that included the first exon were absent in the brains of KO mice, but there was persistent expression of at least one other transcript that does not include the first exon. Wild type (WT, heterozygous (HET, and KO mice were assessed using several well-established behavioral paradigms that model aspects of schizophrenia. Csmd1 KO mice did not differ from wild-type littermates for sensorimotor gating (measured as prepulse inhibition, social interaction, anhedonia (measured by sucrose preference, or sensitivity to the locomotor stimulant effects of the dopaminergic agent d-amphetamine. These data demonstrate that loss of Csmd1 transcripts that include the first exon does not alter multiple well-established behaviors that model aspects of schizophrenia. The SNP most strongly associated with schizophrenia in humans is between exons 3 and 4; therefore, ablation of exon 1 appeared to be a logical animal model. Nevertheless, future studies should consider alternative mouse models including gain-of-function mutations, and loss-of-function mutations that target alternative transcripts of Csmd1.

  8. Methanol teratogenicity in mutant mice with deficient catalase activity and transgenic mice expressing human catalase.

    Science.gov (United States)

    Siu, Michelle T; Wiley, Michael J; Wells, Peter G

    2013-04-01

    The role of catalase in methanol (MeOH) teratogenesis is unclear. In rodents it both detoxifies reactive oxygen species (ROS) and metabolizes MeOH and its formic acid (FA) metabolite. We treated pregnant mice expressing either high (hCat) or low catalase activity (aCat), or their wild-type (WT) controls, with either MeOH (4g/kg ip) or saline. hCat mice and WTs were similarly susceptible to MeOH-initiated ophthalmic abnormalities and cleft palates. aCat and WT mice appeared resistant, precluding assessment of the developmental impact of catalase deficiency. Catalase activity was respectively increased at least 1.5-fold, and decreased by at least 35%, in hCat and aCat embryos and maternal livers. MeOH and FA pharmacokinetic profiles were similar among hCat, aCat and WT strains. Although the hCat results imply no ROS involvement, embryo culture studies suggest this may be confounded by maternal factors and/or a requirement for higher catalase activity in the hCat mice.

  9. Mutation-related differences in exploratory, spatial and depressive-like behavior in pcd and Lurcher cerebellar mutant mice

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    Jan eTuma

    2015-05-01

    Full Text Available The cerebellum is not only essential for motor coordination but is also involved in cognitive and affective processes. These functions of the cerebellum and mechanisms of their disorders in cerebellar injury are not completely understood. There is a wide spectrum of cerebellar mutant mice which are used as models of hereditary cerebellar degenerations. Nevertheless, they differ in pathogenesis of manifestation of the particular mutation and also in the strain background. The aim of this work was to compare spatial navigation, learning and memory in pcd and Lurcher mice, two of the most frequently used cerebellar mutants. The mice were tested in the open field for exploration behavior, in the Morris water maze with visible as well as reversal hidden platform tasks and in the forced swimming test for motivation assessment. Lurcher mice showed different space exploration activity in the open field and a lower tendency to depressive-like behavior in the forced swimming test compared with pcd mice. Severe deficit of spatial navigation was shown in both cerebellar mutants. However, the overall performance of Lurcher mice was better than that of pcd mutants. Lurcher mice showed the ability of visual guidance despite difficulties with the direct swim towards a goal. In the probe trial test, Lurcher mice preferred the visible platform rather than the more recent localization of the hidden goal.

  10. Tau passive immunotherapy in mutant P301L mice: antibody affinity versus specificity.

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    Cristina d'Abramo

    Full Text Available The use of antibodies to treat neurodegenerative diseases has undergone rapid development in the past decade. To date, immunotherapeutic approaches to Alzheimer's disease have mostly targeted amyloid beta as it is a secreted protein that can be found in plasma and CSF and is consequently accessible to circulating antibodies. Few recent publications have suggested the utility of treatment of tau pathology with monoclonal antibodies to tau. Our laboratory has begun a systematic study of different classes of tau monoclonal antibodies using mutant P301L mice. Three or seven months old mutant tau mice were inoculated weekly with tau monoclonal antibodies at a dose of 10 mg/Kg, until seven or ten months of age were reached respectively. Our data strongly support the notion that in P301L animals treated with MC1, a conformational monoclonal antibody specific for PHF-tau, the rate of development of tau pathology is effectively reduced, while injecting DA31, a high affinity tau sequence antibody, does not exert such benefit. MC1 appears superior to DA31 in overall effects, suggesting that specificity is more important than affinity in therapeutic applications. Unfortunately the survival rate of the P301L treated mice was not improved when immunizing either with MC1 or PHF1, a high affinity phospho-tau antibody previously reported to be efficacious in reducing pathological tau. These data demonstrate that passive immunotherapy in mutant tau models may be efficacious in reducing the development of tau pathology, but a great deal of work remains to be done to carefully select the tau epitopes to target.

  11. Subtype-specific reduction of olfactory bulb interneurons in Pax6 heterozygous mutant mice.

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    Haba, Hasumi; Nomura, Tadashi; Suto, Fumikazu; Osumi, Noriko

    2009-09-01

    Interneurons in the olfactory bulb (OB) play essential roles in the processing of olfactory information. They are classified into several subpopulations by the expression of different neurochemical markers. Here we focused on a transcription factor Pax6, and examined its expression and function in distinct subtypes of OB interneurons. We identified Pax6 expression in specific subtypes of interneurons in the external plexiform layer (EPL). The number of these interneuron subtypes was dramatically decreased in Pax6 heterozygous mutant mice. These results indicate that Pax6 is required for differentiation and/or maintenance of EPL interneurons in the adult mouse OB.

  12. Ectopic Mineralization and Conductive Hearing Loss in Enpp1asj Mutant Mice, a New Model for Otitis Media and Tympanosclerosis.

    Science.gov (United States)

    Tian, Cong; Harris, Belinda S; Johnson, Kenneth R

    2016-01-01

    Otitis media (OM), inflammation of the middle ear, is a common cause of hearing loss in children and in patients with many different syndromic diseases. Studies of the human population and mouse models have revealed that OM is a multifactorial disease with many environmental and genetic contributing factors. Here, we report on otitis media-related hearing loss in asj (ages with stiffened joints) mutant mice, which bear a point mutation in the Enpp1 gene. Auditory-evoked brainstem response (ABR) measurements revealed that around 90% of the mutant mice (Enpp1asj/asj) tested had moderate to severe hearing impairment in at least one ear. The ABR thresholds were variable and generally elevated with age. We found otitis media with effusion (OME) in all of the hearing-impaired Enpp1asj/asj mice by anatomic and histological examinations. The volume and inflammatory cell content of the effusion varied among the asj mutant mice, but all mutants exhibited a thickened middle ear epithelium with fibrous polyps and more mucin-secreting goblet cells than controls. Other abnormalities observed in the Enpp1 mutant mice include over-ossification at the round window ridge, thickened and over-calcified stapedial artery, fusion of malleus and incus, and white patches on the inside of tympanic membrane, some of which are typical symptoms of tympanosclerosis. An excessive yellow discharge was detected in the outer ear canal of older asj mutant mice, with 100% penetrance by 5 months of age, and contributes to the progressive nature of the hearing loss. This is the first report of hearing loss and ear pathology associated with an Enpp1 mutation in mice. The Enpp1asj mutant mouse provides a new animal model for studying tympanosclerotic otitis and otitis media with effusion, and also provides a specific model for the hearing loss recently reported to be associated with human ENPP1 mutations causing generalized arterial calcification of infancy and hypophosphatemic rickets.

  13. Fission Yeast Apc15 Stabilizes MCC-Cdc20-APC/C Complexes, Ensuring Efficient Cdc20 Ubiquitination and Checkpoint Arrest.

    Science.gov (United States)

    May, Karen M; Paldi, Flora; Hardwick, Kevin G

    2017-03-28

    During mitosis, cells must segregate the replicated copies of their genome to their daughter cells with extremely high fidelity. Segregation errors lead to an abnormal chromosome number (aneuploidy), which typically results in disease or cell death [1]. Chromosome segregation and anaphase onset are initiated through the action of the multi-subunit E3 ubiquitin ligase known as the anaphase-promoting complex or cyclosome (APC/C [2]). The APC/C is inhibited by the spindle checkpoint in the presence of kinetochore attachment defects [3, 4]. Here we demonstrate that two non-essential APC/C subunits (Apc14 and Apc15) regulate association of spindle checkpoint proteins, in the form of the mitotic checkpoint complex (MCC), with the APC/C. apc14Δ mutants display increased MCC association with the APC/C and are unable to silence the checkpoint efficiently. Conversely, apc15Δ mutants display reduced association between the MCC and APC/C, are defective in poly-ubiquitination of Cdc20, and are checkpoint defective. In vitro reconstitution studies have shown that human MCC-APC/C can contain two molecules of Cdc20 [5-7]. Using a yeast strain expressing two Cdc20 genes with different epitope tags, we show by co-immunoprecipitation that this is true in vivo. MCC binding to the second molecule of Cdc20 is mediated via the C-terminal KEN box in Mad3. Somewhat surprisingly, complexes containing both molecules of Cdc20 accumulate in apc15Δ cells, and the implications of this observation are discussed.

  14. Synaptogenesis and outer segment formation are perturbed in the neural retina of Crx mutant mice

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    Raviola Elio

    2005-01-01

    Full Text Available Abstract Background In Leber's congenital amaurosis (LCA, affected individuals are blind, or nearly so, from birth. This early onset suggests abnormal development of the neural retina. Mutations in genes that affect the development and/or function of photoreceptor cells have been found to be responsible in some families. These examples include mutations in the photoreceptor transcription factor, Crx. Results A Crx mutant strain of mice was created to serve as a model for LCA and to provide more insight into Crx's function. In this study, an ultrastructural analysis of the developing retina in Crx mutant mice was performed. Outer segment morphogenesis was found to be blocked at the elongation stage, leading to a failure in production of the phototransduction apparatus. Further, Crx-/- photoreceptors demonstrated severely abnormal synaptic endings in the outer plexiform layer. Conclusions This is the first report of a synaptogenesis defect in an animal model for LCA. These data confirm the essential role this gene plays in multiple aspects of photoreceptor development and extend our understanding of the basic pathology of LCA.

  15. Enhanced subcortical spreading depression in familial hemiplegic migraine type 1 mutant mice.

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    Eikermann-Haerter, Katharina; Yuzawa, Izumi; Qin, Tao; Wang, Yumei; Baek, Kwangyeol; Kim, Young Ro; Hoffmann, Ulrike; Dilekoz, Ergin; Waeber, Christian; Ferrari, Michel D; van den Maagdenberg, Arn M J M; Moskowitz, Michael A; Ayata, Cenk

    2011-04-13

    Familial hemiplegic migraine type 1, a monogenic migraine variant with aura, is linked to gain-of-function mutations in the CACNA1A gene encoding Ca(V)2.1 channels. The S218L mutation causes severe channel dysfunction, and paroxysmal migraine attacks can be accompanied by seizures, coma, and hemiplegia; patients expressing the R192Q mutation exhibit hemiplegia only. Familial hemiplegic migraine knock-in mice expressing the S218L or R192Q mutation are highly susceptible to cortical spreading depression, the electrophysiological surrogate for migraine aura, and develop severe and prolonged motor deficits after spreading depression. The S218L mutants also develop coma and seizures and sometimes die. To investigate underlying mechanisms for these symptoms, we used multielectrode electrophysiological recordings, diffusion-weighted magnetic resonance imaging, and c-fos immunohistochemistry to trace spreading depression propagation into subcortical structures. We showed that unlike the wild type, cortical spreading depression readily propagated into subcortical structures in both familial hemiplegic migraine type 1 mutants. Whereas the facilitated subcortical spread appeared limited to the striatum in R192Q, hippocampal and thalamic spread was detected in the S218L mutants with an allele-dosage effect. Both strains exhibited increased susceptibility to subcortical spreading depression and reverberating spreading depression waves. Altogether, these data show that spreading depression propagates between cortex, basal ganglia, diencephalon, and hippocampus in genetically susceptible brains, which could explain the prolonged hemiplegia, coma, and seizure phenotype in this variant of migraine with aura.

  16. Seizure susceptibility of neuropeptide-Y null mutant mice in amygdala kindling and chemical-induced seizure models.

    Science.gov (United States)

    Shannon, Harlan E; Yang, Lijuan

    2004-01-01

    Neuropeptide Y (NPY) administered exogenously is anticonvulsant, and, NPY null mutant mice are more susceptible to kainate-induced seizures. In order to better understand the potential role of NPY in epileptogenesis, the present studies investigated the development of amygdala kindling, post-kindling seizure thresholds, and anticonvulsant effects of carbamazepine and levetiracetam in 129S6/SvEv NPY(+/+) and NPY(-/-) mice. In addition, susceptibility to pilocarpine- and kainate-induced seizures was compared in NPY(+/+) and (-/-) mice. The rate of amygdala kindling development did not differ in the NPY(-/-) and NPY(+/+) mice either when kindling stimuli were presented once daily for at least 20 days, or, 12 times daily for 2 days. However, during kindling development, the NPY(-/-) mice had higher seizure severity scores and longer afterdischarge durations than the NPY(+/+) mice. Post-kindling, the NPY(-/-) mice had markedly lower afterdischarge thresholds and longer afterdischarge durations than NPY (+/+) mice. Carbamazepine and levetiracetam increased the seizure thresholds of both NPY (-/-) and (+/+) mice. In addition, NPY (-/-) mice had lower thresholds for both kainate- and pilocarpine-induced seizures. The present results in amygdala kindling and chemical seizure models suggest that NPY may play a more prominent role in determining seizure thresholds and severity of seizures than in events leading to epileptogenesis. In addition, a lack of NPY does not appear to confer drug-resistance in that carbamazepine and levetiracetam were anticonvulsant in both wild type (WT) and NPY null mutant mice.

  17. Differential gene expression in ADAM10 and mutant ADAM10 transgenic mice

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    Postina Rolf

    2009-02-01

    Full Text Available Abstract Background In a transgenic mouse model of Alzheimer disease (AD, cleavage of the amyloid precursor protein (APP by the α-secretase ADAM10 prevented amyloid plaque formation, and alleviated cognitive deficits. Furthermore, ADAM10 overexpression increased the cortical synaptogenesis. These results suggest that upregulation of ADAM10 in the brain has beneficial effects on AD pathology. Results To assess the influence of ADAM10 on the gene expression profile in the brain, we performed a microarray analysis using RNA isolated from brains of five months old mice overexpressing either the α-secretase ADAM10, or a dominant-negative mutant (dn of this enzyme. As compared to non-transgenic wild-type mice, in ADAM10 transgenic mice 355 genes, and in dnADAM10 mice 143 genes were found to be differentially expressed. A higher number of genes was differentially regulated in double-transgenic mouse strains additionally expressing the human APP[V717I] mutant. Overexpression of proteolytically active ADAM10 affected several physiological pathways, such as cell communication, nervous system development, neuron projection as well as synaptic transmission. Although ADAM10 has been implicated in Notch and β-catenin signaling, no significant changes in the respective target genes were observed in adult ADAM10 transgenic mice. Real-time RT-PCR confirmed a downregulation of genes coding for the inflammation-associated proteins S100a8 and S100a9 induced by moderate ADAM10 overexpression. Overexpression of the dominant-negative form dnADAM10 led to a significant increase in the expression of the fatty acid-binding protein Fabp7, which also has been found in higher amounts in brains of Down syndrome patients. Conclusion In general, there was only a moderate alteration of gene expression in ADAM10 overexpressing mice. Genes coding for pro-inflammatory or pro-apoptotic proteins were not over-represented among differentially regulated genes. Even a decrease of

  18. Global gene profiling of aging lungs in Atp8b1 mutant mice

    Science.gov (United States)

    Soundararajan, Ramani; Stearns, Timothy M.; Czachor, Alexander; Fukumoto, Jutaro; Turn, Christina; Westermann-Clark, Emma; Breitzig, Mason; Tan, Lee; Lockey, Richard F.; King, Benjamin L.; Kolliputi, Narasaiah

    2016-01-01

    Objective Recent studies implicate cardiolipin oxidation in several age-related diseases. Atp8b1 encoding Type 4 P-type ATPases is a cardiolipin transporter. Mutation in Atp8b1 gene or inflammation of the lungs impairs the capacity of Atp8b1 to clear cardiolipin from lung fluid. However, the link between Atp8b1 mutation and age-related gene alteration is unknown. Therefore, we investigated how Atp8b1 mutation alters age-related genes. Methods We performed Affymetrix gene profiling of lungs isolated from young (7-9 wks, n=6) and aged (14 months, 14 M, n=6) C57BL/6 and Atp8b1 mutant mice. In addition, Ingenuity Pathway Analysis (IPA) was performed. Differentially expressed genes were validated by quantitative real-time PCR (qRT-PCR). Results Global transcriptome analysis revealed 532 differentially expressed genes in Atp8b1 lungs, 157 differentially expressed genes in C57BL/6 lungs, and 37 overlapping genes. IPA of age-related genes in Atp8b1 lungs showed enrichment of Xenobiotic metabolism and Nrf2-mediated signaling pathways. The increase in Adamts2 and Mmp13 transcripts in aged Atp8b1 lungs was validated by qRT-PCR. Similarly, the decrease in Col1a1 and increase in Cxcr6 transcripts was confirmed in both Atp8b1 mutant and C57BL/6 lungs. Conclusion Based on transcriptome profiling, our study indicates that Atp8b1 mutant mice may be susceptible to age-related lung diseases. PMID:27689529

  19. Antioxidant treatment promotes prostate epithelial proliferation in Nkx3.1 mutant mice.

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    Erin E Martinez

    Full Text Available Discordant results in preclinical and clinical trials have raised questions over the effectiveness of antioxidants in prostate cancer chemoprevention. Results from the large-scale Selenium and Vitamin E Cancer Prevention Trial (SELECT showed that antioxidants failed to prevent, and in some cases promoted, prostate cancer formation in men without a history of the disease. One possible explanation for these alarming results is the notion that the effects of antioxidant treatment on the prostate are modified by specific, intrinsic genetic risk factors, causing some men to respond negatively to antioxidant treatment. Loss of expression of the homeobox transcription factor NKX3.1 in the prostate is frequently associated with human prostate cancer. Nkx3.1 mutant mice display prostatic hyperplasia and dysplasia and are used as a model of the early stages of prostate cancer initiation. While the mechanisms by which Nkx3.1 loss promotes prostate tumorigenicity are not completely understood, published data have suggested that elevated reactive oxygen species (ROS associated with Nkx3.1 loss may be a causative factor. Here we have tested this hypothesis by treating Nkx3.1 mutant mice with the antioxidant N-acetylcysteine (NAC for 13 weeks post-weaning. Surprisingly, while NAC treatment decreased ROS levels in Nkx3.1 mutant mouse prostates, it failed to reduce prostatic epithelial hyperplasia/dysplasia. Rather, NAC treatment increased epithelial cell proliferation and promoted the expression of a pro-proliferative gene signature. These results show that ROS do not promote proliferation in the Nkx3.1-null prostate, but instead inhibit proliferation, suggesting that antioxidant treatment may encourage prostate epithelial cell proliferation early in prostate tumorigenesis. Our findings provide new insight that may help explain the increased prostate cancer risk observed with vitamin E treatment in the SELECT trial and emphasize the need for preclinical studies

  20. Behavioral evidence for photophobia and stress-related ipsilateral head pain in transgenic Cacna1a mutant mice.

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    Chanda, Mona Lisa; Tuttle, Alexander H; Baran, Inna; Atlin, Cori; Guindi, Daniella; Hathaway, Georgia; Israelian, Nyrie; Levenstadt, Jeremy; Low, Daniel; Macrae, Lynn; O'Shea, Louise; Silver, Alex; Zendegui, Elaina; Mariette Lenselink, A; Spijker, Sabine; Ferrari, Michel D; van den Maagdenberg, Arn M J M; Mogil, Jeffrey S

    2013-08-01

    Migraine is a highly prevalent, disabling and complex episodic brain disorder whose pathogenesis is poorly understood, due in part to the lack of valid animal models. Here we report behavioral evidence of hallmark migraine features, photophobia and unilateral head pain, in transgenic knock-in mice bearing human familial hemiplegic migraine, type 1 (FHM-1) gain-of-function missense mutations (R192Q or S218L) in the Cacna1a gene encoding the CaV2.1 calcium channel α1 subunit. Photophobia was demonstrated using a modified elevated plus maze in which the safe closed arms were brightly illuminated; mutant mice avoided the light despite showing no differences in the standard (anxiety) version of the test. Multiple behavioral measures suggestive of spontaneous head pain were found in 192Q mutants subjected to novelty and/or restraint stress. These behaviors were: (1) more frequent in mutant versus wildtype mice; (2) lateralized in mutant but not in wildtype mice; (3) more frequent in females versus males; and (4) dose-dependently normalized by systemic administration of 2 different acute analgesics, rizatriptan and morphine. Furthermore, some of these behaviors were found to be more frequent and severe in 218L compared to 192Q mutants, consistent with the clinical presentation in humans. We suggest that Cacna1a transgenic mice can experience migraine-related head pain and can thus serve as unique tools to study the pathogenesis of migraine and test novel antimigraine agents.

  1. Mutant laboratory mice with abnormalities in hair follicle morphogenesis, cycling, and/or structure: an update.

    Science.gov (United States)

    Nakamura, Motonobu; Schneider, Marlon R; Schmidt-Ullrich, Ruth; Paus, Ralf

    2013-01-01

    Human hair disorders comprise a number of different types of alopecia, atrichia, hypotrichosis, distinct hair shaft disorders as well as hirsutism and hypertrichosis. Their causes vary from genodermatoses (e.g. hypotrichoses) via immunological disorders (e.g. alopecia areata, autoimmune cicatrical alopecias) to hormone-dependent abnormalities (e.g. androgenetic alopecia). A large number of spontaneous mouse mutants and genetically engineered mice develop abnormalities in hair follicle morphogenesis, cycling, and/or hair shaft formation, whose analysis has proven invaluable to define the molecular regulation of hair growth, ranging from hair follicle development, and cycling to hair shaft formation and stem cell biology. Also, the accumulating reports on hair phenotypes of mouse strains provide important pointers to better understand the molecular mechanisms underlying human hair growth disorders. Since numerous new mouse mutants with a hair phenotype have been reported since the publication of our earlier review on this matter a decade ago, we present here an updated, tabulated mini-review. The updated annotated tables list a wide selection of mouse mutants with hair growth abnormalities, classified into four categories: Mutations that affect hair follicle (1) morphogenesis, (2) cycling, (3) structure, and (4) mutations that induce extrafollicular events (for example immune system defects) resulting in secondary hair growth abnormalities. This synthesis is intended to provide a useful source of reference when studying the molecular controls of hair follicle growth and differentiation, and whenever the hair phenotypes of a newly generated mouse mutant need to be compared with existing ones. Copyright © 2012 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

  2. Tlr4-mutant mice are resistant to acute alcohol-induced sterol-regulatory element binding protein activation and hepatic lipid accumulation

    Science.gov (United States)

    Zhang, Zhi-Hui; Liu, Xiao-Qian; Zhang, Cheng; He, Wei; Wang, Hua; Chen, Yuan-Hua; Liu, Xiao-Jing; Chen, Xi; Xu, De-Xiang

    2016-01-01

    Previous studies demonstrated that acute alcohol intoxication caused hepatic lipid accumulation. The present study showed that acute alcohol intoxication caused hepatic lipid accumulation in Tlr4-wild-type mice but not in Tlr4-mutant mice. Hepatic sterol-regulatory element binding protein (SREBP)-1, a transcription factor regulating fatty acid and triglyceride (TG) synthesis, was activated in alcohol-treated Tlr4-wild-type mice but not in Tlr4-mutant mice. Hepatic Fas, Acc, Scd-1 and Dgat-2, the key genes for fatty acid and TG synthesis, were up-regulated in alcohol-treated Tlr4-wild-type mice but not in Tlr4-mutant mice. Additional experiment showed that hepatic MyD88 was elevated in alcohol-treated Tlr4-wild-type mice but not in Tlr4-mutant mice. Hepatic NF-κB was activated in alcohol-treated Tlr4-wild-type mice but not in Tlr4-mutant mice. Moreover, hepatic GSH content was reduced and hepatic MDA level was elevated in alcohol-treated Tlr4-wild-type mice but not in Tlr4-mutant mice. Hepatic CYP2E1 was elevated in alcohol-treated Tlr4-wild-type mice but not in Tlr4-mutant mice. Hepatic p67phox and gp91phox, two NADPH oxidase subunits, were up-regulated in alcohol-treated Tlr4-wild-type mice but not in Tlr4-mutant mice. Alpha-phenyl-N-t-butylnitrone (PBN), a free radical spin-trapping agent, protected against alcohol-induced hepatic SREBP-1 activation and hepatic lipid accumulation. In conclusion, Tlr4-mutant mice are resistant to acute alcohol-induced hepatic SREBP-1 activation and hepatic lipid accumulation. PMID:27627966

  3. Mutant Brucella abortus membrane fusogenic protein induces protection against challenge infection in mice.

    Science.gov (United States)

    de Souza Filho, Job Alves; de Paulo Martins, Vicente; Campos, Priscila Carneiro; Alves-Silva, Juliana; Santos, Nathalia V; de Oliveira, Fernanda Souza; Menezes, Gustavo B; Azevedo, Vasco; Cravero, Silvio Lorenzo; Oliveira, Sergio Costa

    2015-04-01

    Brucella species can cause brucellosis, a zoonotic disease that causes serious livestock economic losses and represents a public health threat. The mechanism of virulence of Brucella spp. is not yet fully understood. Therefore, it is crucial to identify new molecules that serve as virulence factors to better understand this host-pathogen interplay. Here, we evaluated the role of the Brucella membrane fusogenic protein (Mfp) and outer membrane protein 19 (Omp19) in bacterial pathogenesis. In this study, we showed that B. abortus Δmfp::kan and Δomp19::kan deletion mutant strains have reduced persistence in vivo in C57BL/6 and interferon regulatory factor 1 (IRF-1) knockout (KO) mice. Additionally, 24 h after macrophage infection with a Δmfp::kan or Δomp19::kan strain expressing green fluorescent protein (GFP) approximately 80% or 65% of Brucella-containing vacuoles (BCVs) retained the late endosomal/lysosomal marker LAMP-1, respectively, whereas around 60% of BCVs containing wild-type S2308 were found in LAMP-1-negative compartments. B. abortus Δomp19::kan was attenuated in vivo but had a residual virulence in C57BL/6 and IRF-1 KO mice, whereas the Δmfp::kan strain had a lower virulence in these same mouse models. Furthermore, Δmfp::kan and Δomp19::kan strains were used as live vaccines. Challenge experiments revealed that in C57BL/6 and IRF-1 KO mice, the Δmfp::kan strain induced greater protection than the vaccine RB51 and protection similar that of vaccine S19. However, a Δomp19::kan strain induced protection similar to that of RB51. Thus, these results demonstrate that Brucella Mfp and Omp19 are critical for full bacterial virulence and that the Δmfp::kan mutant may serve as a potential vaccine candidate in future studies.

  4. Alterations of Retinal Vasculature in Cystathionine-Beta-Synthase Mutant Mice, a Model of Hyperhomocysteinemia

    Science.gov (United States)

    Tawfik, Amany; Al-Shabrawey, Mohamed; Roon, Penny; Sonne, Srinivas; Covar, Jason A.; Matragoon, Surapoon; Ganapathy, Preethi S.; Atherton, Sally S.; El-Remessy, Azza; Ganapathy, Vadivel; Smith, Sylvia B.

    2013-01-01

    Purpose. Mice with moderate/severe hyperhomocysteinemia due to deficiency or absence of the cbs gene encoding cystathionine-beta-synthase (CBS) have marked retinal disruption, ganglion cell loss, optic nerve mitochondrial dysfunction, and ERG defects; those with mild hyperhomocysteinemia have delayed retinal morphological/functional phenotype. Excess homocysteine is a risk factor for cardiovascular diseases; however, it is not known whether excess homocysteine alters retinal vasculature. Methods. Cbs+/+, cbs+/−, and cbs−/− mice (age ∼3 weeks) were subjected to angiography; retinas were harvested for cryosections, flat-mount preparations, or trypsin digestion and subjected to immunofluorescence microscopy to visualize vessels using isolectin-B4, to detect angiogenesis using anti-VEGF and anti-endoglin (anti-CD105) and activated glial cells (anti-glial fibrillary acidic protein [anti-GFAP]) and to investigate the blood–retinal barrier using the tight junction markers zonula occludens-1 (ZO-1) and occludin. Expression of vegf was determined by quantitative RT-PCR (qRT-PCR) and immunoblotting. Human retinal endothelial cells (HRECs) were treated with excess homocysteine to analyze permeability. Results. Angiography revealed vascular leakage in cbs−/− mice; immunohistochemical analysis demonstrated vascular patterns consistent with ischemia; isolectin-B4 labeling revealed a capillary-free zone centrally and new vessels with capillary tufts midperipherally. This was associated with increased vegf mRNA and protein, CD105, and GFAP in cbs−/− retinas concomitant with a marked decrease in ZO-1 and occludin. Homocysteine-treated HRECs showed increased permeability. Conclusions. Severe elevation of homocysteine in cbs−/− mutant mice is accompanied by alterations in retinal vasculature (ischemia, neovascularization, and incompetent blood–retinal barrier). The marked disruption of retinal structure and decreased visual function reported in cbs−/− mice

  5. Mutant mice lacking the p53 C-terminal domain model telomere syndromes.

    Science.gov (United States)

    Simeonova, Iva; Jaber, Sara; Draskovic, Irena; Bardot, Boris; Fang, Ming; Bouarich-Bourimi, Rachida; Lejour, Vincent; Charbonnier, Laure; Soudais, Claire; Bourdon, Jean-Christophe; Huerre, Michel; Londono-Vallejo, Arturo; Toledo, Franck

    2013-06-27

    Mutations in p53, although frequent in human cancers, have not been implicated in telomere-related syndromes. Here, we show that homozygous mutant mice expressing p53Δ31, a p53 lacking the C-terminal domain, exhibit increased p53 activity and suffer from aplastic anemia and pulmonary fibrosis, hallmarks of syndromes caused by short telomeres. Indeed, p53Δ31/Δ31 mice had short telomeres and other phenotypic traits associated with the telomere disease dyskeratosis congenita and its severe variant the Hoyeraal-Hreidarsson syndrome. Heterozygous p53+/Δ31 mice were only mildly affected, but decreased levels of Mdm4, a negative regulator of p53, led to a dramatic aggravation of their symptoms. Importantly, several genes involved in telomere metabolism were downregulated in p53Δ31/Δ31 cells, including Dyskerin, Rtel1, and Tinf2, which are mutated in dyskeratosis congenita, and Terf1, which is implicated in aplastic anemia. Together, these data reveal that a truncating mutation can activate p53 and that p53 plays a major role in the regulation of telomere metabolism.

  6. Expression of mutant TDP-43 induces neuronal dysfunction in transgenic mice

    Directory of Open Access Journals (Sweden)

    Dickson Dennis W

    2011-10-01

    Full Text Available Abstract Background Abnormal distribution, modification and aggregation of transactivation response DNA-binding protein 43 (TDP-43 are the hallmarks of multiple neurodegenerative diseases, especially frontotemporal lobar degeneration with ubiquitin-positive inclusions (FTLD-U and amyotrophic lateral sclerosis (ALS. Researchers have identified 44 mutations in the TARDBP gene that encode TDP-43 as causative for cases of sporadic and familial ALS http://www.molgen.ua.ac.be/FTDMutations/. Certain mutant forms of TDP-43, such as M337V, are associated with increased low molecular weight (LMW fragments compared to wild-type (WT TDP-43 and cause neuronal apoptosis and developmental delay in chick embryos. Such findings support a direct link between altered TDP-43 function and neurodegeneration. Results To explore the pathogenic properties of the M337V mutation, we generated and characterized two mouse lines expressing human TDP-43 (hTDP-43M337V carrying this mutation. hTDP-43M337V was expressed primarily in the nuclei of neurons in the brain and spinal cord, and intranuclear and cytoplasmic phosphorylated TDP-43 aggregates were frequently detected. The levels of TDP-43 LMW products of ~25 kDa and ~35 kDa species were also increased in the transgenic mice. Moreover, overexpression of hTDP-43M337V dramatically down regulated the levels of mouse TDP-43 (mTDP-43 protein and RNA, indicating TDP-43 levels are tightly controlled in mammalian systems. TDP-43M337V mice displayed reactive gliosis, widespread ubiquitination, chromatolysis, gait abnormalities, and early lethality. Abnormal cytoplasmic mitochondrial aggregates and abnormal phosphorylated tau were also detected in the mice. Conclusion Our novel TDP-43M337V mouse model indicates that overexpression of hTDP-43M337V alone is toxic in vivo. Because overexpression of hTDP-43 in wild-type TDP-43 and TDP-43M337V mouse models produces similar phenotypes, the mechanisms causing pathogenesis in the mutant

  7. Enhanced food anticipatory activity associated with enhanced activation of extrahypothalamic neural pathways in serotonin2C receptor null mutant mice.

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    Jennifer L Hsu

    Full Text Available The ability to entrain circadian rhythms to food availability is important for survival. Food-entrained circadian rhythms are characterized by increased locomotor activity in anticipation of food availability (food anticipatory activity. However, the molecular components and neural circuitry underlying the regulation of food anticipatory activity remain unclear. Here we show that serotonin(2C receptor (5-HT2CR null mutant mice subjected to a daytime restricted feeding schedule exhibit enhanced food anticipatory activity compared to wild-type littermates, without phenotypic differences in the impact of restricted feeding on food consumption, body weight loss, or blood glucose levels. Moreover, we show that the enhanced food anticipatory activity in 5-HT2CR null mutant mice develops independent of external light cues and persists during two days of total food deprivation, indicating that food anticipatory activity in 5-HT2CR null mutant mice reflects the locomotor output of a food-entrainable oscillator. Whereas restricted feeding induces c-fos expression to a similar extent in hypothalamic nuclei of wild-type and null mutant animals, it produces enhanced expression in the nucleus accumbens and other extrahypothalamic regions of null mutant mice relative to wild-type subjects. These data suggest that 5-HT2CRs gate food anticipatory activity through mechanisms involving extrahypothalamic neural pathways.

  8. Primary coenzyme Q deficiency in Pdss2 mutant mice causes isolated renal disease.

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    Min Peng

    2008-04-01

    Full Text Available Coenzyme Q (CoQ is an essential electron carrier in the respiratory chain whose deficiency has been implicated in a wide variety of human mitochondrial disease manifestations. Its multi-step biosynthesis involves production of polyisoprenoid diphosphate in a reaction that requires the enzymes be encoded by PDSS1 and PDSS2. Homozygous mutations in either of these genes, in humans, lead to severe neuromuscular disease, with nephrotic syndrome seen in PDSS2 deficiency. We now show that a presumed autoimmune kidney disease in mice with the missense Pdss2(kd/kd genotype can be attributed to a mitochondrial CoQ biosynthetic defect. Levels of CoQ9 and CoQ10 in kidney homogenates from B6.Pdss2(kd/kd mutants were significantly lower than those in B6 control mice. Disease manifestations originate specifically in glomerular podocytes, as renal disease is seen in Podocin/cre,Pdss2(loxP/loxP knockout mice but not in conditional knockouts targeted to renal tubular epithelium, monocytes, or hepatocytes. Liver-conditional B6.Alb/cre,Pdss2(loxP/loxP knockout mice have no overt disease despite demonstration that their livers have undetectable CoQ9 levels, impaired respiratory capacity, and significantly altered intermediary metabolism as evidenced by transcriptional profiling and amino acid quantitation. These data suggest that disease manifestations of CoQ deficiency relate to tissue-specific respiratory capacity thresholds, with glomerular podocytes displaying the greatest sensitivity to Pdss2 impairment.

  9. Analysis of pools of targeted Salmonella deletion mutants identifies novel genes affecting fitness during competitive infection in mice.

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    Carlos A Santiviago

    2009-07-01

    Full Text Available Pools of mutants of minimal complexity but maximal coverage of genes of interest facilitate screening for genes under selection in a particular environment. We constructed individual deletion mutants in 1,023 Salmonella enterica serovar Typhimurium genes, including almost all genes found in Salmonella but not in related genera. All mutations were confirmed simultaneously using a novel amplification strategy to produce labeled RNA from a T7 RNA polymerase promoter, introduced during the construction of each mutant, followed by hybridization of this labeled RNA to a Typhimurium genome tiling array. To demonstrate the ability to identify fitness phenotypes using our pool of mutants, the pool was subjected to selection by intraperitoneal injection into BALB/c mice and subsequent recovery from spleens. Changes in the representation of each mutant were monitored using T7 transcripts hybridized to a novel inexpensive minimal microarray. Among the top 120 statistically significant spleen colonization phenotypes, more than 40 were mutations in genes with no previously known role in this model. Fifteen phenotypes were tested using individual mutants in competitive assays of intraperitoneal infection in mice and eleven were confirmed, including the first two examples of attenuation for sRNA mutants in Salmonella. We refer to the method as Array-based analysis of cistrons under selection (ABACUS.

  10. Analysis of pools of targeted Salmonella deletion mutants identifies novel genes affecting fitness during competitive infection in mice.

    Directory of Open Access Journals (Sweden)

    Carlos A Santiviago

    2009-07-01

    Full Text Available Pools of mutants of minimal complexity but maximal coverage of genes of interest facilitate screening for genes under selection in a particular environment. We constructed individual deletion mutants in 1,023 Salmonella enterica serovar Typhimurium genes, including almost all genes found in Salmonella but not in related genera. All mutations were confirmed simultaneously using a novel amplification strategy to produce labeled RNA from a T7 RNA polymerase promoter, introduced during the construction of each mutant, followed by hybridization of this labeled RNA to a Typhimurium genome tiling array. To demonstrate the ability to identify fitness phenotypes using our pool of mutants, the pool was subjected to selection by intraperitoneal injection into BALB/c mice and subsequent recovery from spleens. Changes in the representation of each mutant were monitored using T7 transcripts hybridized to a novel inexpensive minimal microarray. Among the top 120 statistically significant spleen colonization phenotypes, more than 40 were mutations in genes with no previously known role in this model. Fifteen phenotypes were tested using individual mutants in competitive assays of intraperitoneal infection in mice and eleven were confirmed, including the first two examples of attenuation for sRNA mutants in Salmonella. We refer to the method as Array-based analysis of cistrons under selection (ABACUS.

  11. A Yersinia pestis lpxM-mutant live vaccine induces enhanced immunity against bubonic plague in mice and guinea pigs.

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    Feodorova, V A; Pan'kina, L N; Savostina, E P; Sayapina, L V; Motin, V L; Dentovskaya, S V; Shaikhutdinova, R Z; Ivanov, S A; Lindner, B; Kondakova, A N; Bystrova, O V; Kocharova, N A; Senchenkova, S N; Holst, O; Pier, G B; Knirel, Y A; Anisimov, A P

    2007-11-01

    The lpxM mutant of the live vaccine Yersinia pestis EV NIIEG strain synthesising a less toxic penta-acylated lipopolysaccharide was found to be avirulent in mice and guinea pigs, notably showing no measurable virulence in Balb/c mice which do retain some susceptibility to the parental strain itself. Twenty-one days after a single injection of the lpxM-mutant, 85-100% protection was achieved in outbred mice and guinea pigs, whereas a 43% protection rate was achieved in Balb/c mice given single low doses (10(3) to 2.5 x 10(4) CFU) of this vaccine. A subcutaneous challenge with 2000 median lethal doses (equal to 20,000 CFU) of fully virulent Y. pestis 231 strain, is a 6-10-fold higher dose than that which the EV NIIEG itself can protect against.

  12. A Mycobacterium leprae Hsp65 mutant as a candidate for mitigating lupus aggravation in mice.

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    Eliana B Marengo

    Full Text Available Hsp60 is an abundant and highly conserved family of intracellular molecules. Increased levels of this family of proteins have been observed in the extracellular compartment in chronic inflammation. Administration of M. leprae Hsp65 [WT] in [NZBxNZW]F(1 mice accelerates the Systemic Lupus Erythematosus [SLE] progression whereas the point mutated K(409A Hsp65 protein delays the disease. Here, the biological effects of M. leprae Hsp65 Leader pep and K(409A pep synthetic peptides, which cover residues 352-371, are presented. Peptides had immunomodulatory effects similar to that observed with their respective proteins on survival and the combined administration of K(409A+Leader pep or K(409A pep+WT showed that the mutant forms were able to inhibit the deleterious effect of WT on mortality, indicating the neutralizing potential of the mutant molecules in SLE progression. Molecular modeling showed that replacing Lysine by Alanine affects the electrostatic potential of the 352-371 region. The number of interactions observed for WT is much higher than for Hsp65 K(409A and mouse Hsp60. The immunomodulatory effects of the point-mutated protein and peptide occurred regardless of the catalytic activity. These findings may be related to the lack of effect on survival when F(1 mice were inoculated with Hsp60 or K(409A pep. Our findings indicate the use of point-mutated Hsp65 molecules, such as the K(409A protein and its corresponding peptide, that may minimize or delay the onset of SLE, representing a new approach to the treatment of autoimmune diseases.

  13. Developmentally-faithful and effective human erythropoiesis in immunodeficient and Kit mutant mice.

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    Fiorini, Claudia; Abdulhay, Nour J; McFarland, Sean K; Munschauer, Mathias; Ulirsch, Jacob C; Chiarle, Roberto; Sankaran, Vijay G

    2017-09-01

    Immunodeficient mouse models have been valuable for studies of human hematopoiesis, but high-fidelity recapitulation of erythropoiesis in most xenograft recipients remains elusive. Recently developed immunodeficient and Kit mutant mice, however, have provided a suitable background to achieve higher-level human erythropoiesis after long-term hematopoietic engraftment. While there has been some characterization of human erythropoiesis in these models, a comprehensive analysis from various human developmental stages has not yet been reported. Here, we have utilized cell surface phenotypes, morphologic analyses, and molecular studies to fully characterize human erythropoiesis from multiple developmental stages in immunodeficient and Kit mutant mouse models following long-term hematopoietic stem and progenitor cell engraftment. We show that human erythropoiesis in such models demonstrates complete maturation and enucleation, as well as developmentally appropriate globin gene expression. These results provide a framework for future studies to utilize this model system for interrogating disorders affecting human erythropoiesis and for developing improved therapeutic approaches. © 2017 Wiley Periodicals, Inc.

  14. Transgenic mice expressing mutant Pinin exhibit muscular dystrophy, nebulin deficiency and elevated expression of slow-type muscle fiber genes

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    Wu, Hsu-Pin; Hsu, Shu-Yuan [Department of Anatomy, Chang Gung University Medical College, Taiwan (China); Wu, Wen-Ai; Hu, Ji-Wei [Transgenic Mouse Core Laboratory, Chang Gung University, Taiwan (China); Ouyang, Pin, E-mail: ouyang@mail.cgu.edu.tw [Department of Anatomy, Chang Gung University Medical College, Taiwan (China); Transgenic Mouse Core Laboratory, Chang Gung University, Taiwan (China); Molecular Medicine Research Center, Chang Gung University, Taiwan (China)

    2014-01-03

    Highlights: •Pnn CCD domain functions as a dominant negative mutant regulating Pnn expression and function. •Pnn CCD mutant Tg mice have a muscle wasting phenotype during development and show dystrophic histological features. •Pnn mutant muscles are susceptible to slow fiber type gene transition and NEB reduction. •The Tg mouse generated by overexpression of the Pnn CCD domain displays many characteristics resembling NEB{sup +/−} mice. -- Abstract: Pinin (Pnn) is a nuclear speckle-associated SR-like protein. The N-terminal region of the Pnn protein sequence is highly conserved from mammals to insects, but the C-terminal RS domain-containing region is absent in lower species. The N-terminal coiled-coil domain (CCD) is, therefore, of interest not only from a functional point of view, but also from an evolutionarily standpoint. To explore the biological role of the Pnn CCD in a physiological context, we generated transgenic mice overexpressing Pnn mutant in skeletal muscle. We found that overexpression of the CCD reduces endogenous Pnn expression in cultured cell lines as well as in transgenic skeletal muscle fibers. Pnn mutant mice exhibited reduced body mass and impaired muscle function during development. Mutant skeletal muscles show dystrophic histological features with muscle fibers heavily loaded with centrally located myonuclei. Expression profiling and pathway analysis identified over-representation of genes in gene categories associated with muscle contraction, specifically those related to slow type fiber. In addition nebulin (NEB) expression level is repressed in Pnn mutant skeletal muscle. We conclude that Pnn downregulation in skeletal muscle causes a muscular dystrophic phenotype associated with NEB deficiency and the CCD domain is incapable of replacing full length Pnn in terms of functional capacity.

  15. Mutant glycyl-tRNA synthetase (Gars ameliorates SOD1(G93A motor neuron degeneration phenotype but has little affect on Loa dynein heavy chain mutant mice.

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    Gareth T Banks

    Full Text Available BACKGROUND: In humans, mutations in the enzyme glycyl-tRNA synthetase (GARS cause motor and sensory axon loss in the peripheral nervous system, and clinical phenotypes ranging from Charcot-Marie-Tooth neuropathy to a severe infantile form of spinal muscular atrophy. GARS is ubiquitously expressed and may have functions in addition to its canonical role in protein synthesis through catalyzing the addition of glycine to cognate tRNAs. METHODOLOGY/PRINCIPAL FINDINGS: We have recently described a new mouse model with a point mutation in the Gars gene resulting in a cysteine to arginine change at residue 201. Heterozygous Gars(C201R/+ mice have locomotor and sensory deficits. In an investigation of genetic mutations that lead to death of motor and sensory neurons, we have crossed the Gars(C201R/+ mice to two other mutants: the TgSOD1(G93A model of human amyotrophic lateral sclerosis and the Legs at odd angles mouse (Dync1h1(Loa which has a defect in the heavy chain of the dynein complex. We found the Dync1h1(Loa/+;Gars(C201R/+ double heterozygous mice are more impaired than either parent, and this is may be an additive effect of both mutations. Surprisingly, the Gars(C201R mutation significantly delayed disease onset in the SOD1(G93A;Gars(C201R/+ double heterozygous mutant mice and increased lifespan by 29% on the genetic background investigated. CONCLUSIONS/SIGNIFICANCE: These findings raise intriguing possibilities for the study of pathogenetic mechanisms in all three mouse mutant strains.

  16. Mutant huntingtin gene-dose impacts on aggregate deposition, DARPP32 expression and neuroinflammation in HdhQ150 mice.

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    Douglas Young

    Full Text Available Huntington's disease (HD is an autosomal dominant, progressive and fatal neurological disorder caused by an expansion of CAG repeats in exon-1 of the huntingtin gene. The encoded poly-glutamine stretch renders mutant huntingtin prone to aggregation. HdhQ150 mice genocopy a pathogenic repeat (∼150 CAGs in the endogenous mouse huntingtin gene and model predominantly pre-manifest HD. Treating early is likely important to prevent or delay HD, and HdhQ150 mice may be useful to assess therapeutic strategies targeting pre-manifest HD. This requires appropriate markers and here we demonstrate, that pre-symptomatic HdhQ150 mice show several dramatic mutant huntingtin gene-dose dependent pathological changes including: (i an increase of neuronal intra-nuclear inclusions (NIIs in brain, (ii an increase of extra-nuclear aggregates in dentate gyrus, (iii a decrease of DARPP32 protein and (iv an increase in glial markers of neuroinflammation, which curiously did not correlate with local neuronal mutant huntingtin inclusion-burden. HdhQ150 mice developed NIIs also in all retinal neuron cell-types, demonstrating that retinal NIIs are not specific to human exon-1 R6 HD mouse models. Taken together, the striking and robust mutant huntingtin gene-dose related changes in aggregate-load, DARPP32 levels and glial activation markers should greatly facilitate future testing of therapeutic strategies in the HdhQ150 HD mouse model.

  17. Restoration of self-sustained circadian rhythmicity by the mutant Clock allele in mice in constant illumination

    NARCIS (Netherlands)

    Spoelstra, K; Oklejewicz, M; Daan, S

    2002-01-01

    Mice mutant for the Clock gene display abnormal circadian behavior characterized by long circadian periods and a tendency to become rapidly arrhythmic in constant darkness (DID). To investigate whether this result is contingent on the absence of light, the authors studied the circadian behavior of

  18. [Accumulation of the bvg- Bordetella pertussis a virulent mutants in the process of experimental whooping cough in mice].

    Science.gov (United States)

    Medkova, A Iu; Siniashina, L N; Rumiantseva, Iu P; Voronina, O L; Kunda, M S; Karataev, G I

    2013-01-01

    The duration of the persistence and dynamics of accumulation of insertion bvg- Bordetella pertussis mutants were studied in lungs of laboratory mice after intranasal and intravenous challenge by virulent bacteria of the causative agent of whooping cough. The capability of the virulent B. pertussis bacteria to long-term persistence in the body of mice was tested. Using the real-time PCR approximately hundred genome equivalents of the B. pertussis DNA were detected in lungs of mice in two months after infection regardless of the way of challenge. Using the bacterial test bacteria were identified during only four weeks after challenge. Bvg- B. pertussis avirulent mutants were accumulated for the infection time. The percentage of the avirulent bacteria in the B. pertussis population reached 50% in 7-9 weeks after challenge. The obtained results show that the laboratory mice can be used for study of the B. pertussis insertion mutant formation dynamics in vivo and confirm the hypothesis about insertional bvg- B. pertussis virulent mutants accumulation during development of pertussis infection in human.

  19. Restoration of self-sustained circadian rhythmicity by the mutant Clock allele in mice in constant illumination

    NARCIS (Netherlands)

    Spoelstra, K; Oklejewicz, M; Daan, S

    2002-01-01

    Mice mutant for the Clock gene display abnormal circadian behavior characterized by long circadian periods and a tendency to become rapidly arrhythmic in constant darkness (DID). To investigate whether this result is contingent on the absence of light, the authors studied the circadian behavior of h

  20. Impairment of the non-homologous end joining and homologous recombination pathways of DNA double strand break repair: Impact on spontaneous and radiation-induced mammary and intestinal tumour risk in Apc min/+ mice.

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    Haines, Jackie W; Coster, Margaret; Bouffler, Simon D

    2015-11-01

    Female Apc(min/+) mice carrying the BALB/c variant of Prkdc or heterozygous knockout for Xrcc2, were sham- or 2 Gy X-irradiated as adults to compare the effect of mild impairments of double-strand break (DSB) repair pathways, non-homologous end joining (NHEJ) and homologous recombination (HR) respectively on spontaneous and radiation-induced mammary and intestinal tumorigenesis. Mice with impaired NHEJ showed no difference in incidence of spontaneous mammary tumours, compared with matched controls, (2.46 fold, P=0.121) and significantly less following irradiation (radiation-induced excess; 0.35 fold, P=0.008). In contrast mice with impaired HR presented with significantly less spontaneous mammary tumours than matched controls (0.33 fold, P=0.027) and significantly more following irradiation (radiation-induced excess; 3.3 fold, P=0.016). Spontaneous and radiation-induced intestinal adenoma multiplicity in the same groups were significantly greater than matched controls for mice with impaired NHEJ (sham; 1.29 fold, P<0.001, radiation-induced excess; 2.55 fold, P<0.001) and mice with impaired HR showed no significant differences (sham; 0.92 fold, P=0.166, radiation-induced excess; 1.16, P=0.274). Genetic insertion events were common in spontaneous tumours from NHEJ impaired mice compared with matched controls. γH2AX foci analysis suggests a significantly faster rate of DSB repair (MANOVA P<0.001) in intestinal than mammary tissue; apoptosis was also higher in irradiated intestine. To conclude, results suggest that pathway of choice for repair of spontaneous and radiation-induced DSBs is influenced by tissue type. NHEJ appears to play a greater role in DSB repair in intestinal tissue since impairment by functional change of Prkdc significantly increases the rate of mis-repair in intestinal but not mammary tissue. HR appears to play a greater role in DSB repair in adult mammary tissue since impaired HR results in significant changes in mammary but not in the intestinal

  1. A mouse renin distal enhancer is essential for blood pressure homeostasis in BAC-rescued renin-null mutant mice.

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    Tanimoto, Keiji; Kanafusa, Sumiyo; Ushiki, Aki; Matsuzaki, Hitomi; Ishida, Junji; Sugiyama, Fumihiro; Fukamizu, Akiyoshi

    2014-10-01

    Renin is predominantly expressed in juxtaglomerular cells in the kidney and regulates blood pressure homeostasis. To examine possible in vivo functions of a mouse distal enhancer (mdE), we generated transgenic mice (TgM) carrying either wild-type or mdE-deficient renin BACs (bacterial artificial chromosome), integrated at the identical chromosomal site. In the kidneys of the TgM, the mdE contributed 80% to basal renin promoter activity. To test for possible physiological roles for the mdE, renin BAC transgenes were used to rescue the hypotensive renin-null mice. Interestingly, renal renin expression in the Tg(BAC):renin-null compound mice was indistinguishable between the wild-type and mutant BAC carriers. Surprisingly, however, the plasma renin activity and angiotensin I concentration in the mdE compound mutant mice were significantly lower than the same parameters in the control mice, and the mutants were consistently hypotensive, demonstrating that blood pressure homeostasis is regulated through transcriptional cis elements controlling renin activity.

  2. Effects of exogenous recombinant APC in mouse models of ischemia reperfusion injury and of atherosclerosis.

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    Karin C A A Wildhagen

    Full Text Available Activated protein C (APC is a serine protease that has both anticoagulant and cytoprotective properties. The cytoprotective effects are protease activated receptor 1 (PAR-1 and endothelial protein C receptor (EPCR dependent and likely underlie protective effects of APC in animal models of sepsis, myocardial infarction and ischemic stroke. S360A-(APC, a variant (APC that has no catalytic activity, binds EPCR and shifts pro-inflammatory signaling of the thrombin-PAR-1 complex to anti-inflammatory signaling. In this study we investigated effects of human (hwt-PC, hS360A-PC, hwt-APC and hS360A-APC in acute (mouse model of acute myocardial ischemia/reperfusion (I/R injury and chronic inflammation (apoE-/- mouse model of atherosclerosis. All h(APC variants significantly reduced myocardial infarct area (p<0.05 following I/R injury. IL-6 levels in heart homogenates did not differ significantly between sham, placebo and treatment groups in I/R injury. None of the h(APC variants decreased number and size of atherosclerotic plaques in apoE-/- mice. Only hS360A-APC slightly affected phenotype of plaques. IL-6 levels in plasma were significantly (p<0.001 decreased in hwt-APC and hS360A-PC treated mice. In the last group levels of monocyte chemotactic protein 1 (MCP-1 were significantly increased (p<0.05. In this study we show that both hwt and hS360A-(APC protect against acute myocardial I/R injury, which implies that protection from I/R injury is independent of the proteolytic activity of APC. However, in the chronic atherosclerosis model hwt and hS360-(APC had only minor effects. When the dose, species and mode of (APC administration will be adjusted, we believe that (APC will have potential to influence development of chronic inflammation as occurring during atherosclerosis as well.

  3. APC/C-Cdh1-dependent anaphase and telophase progression during mitotic slippage

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    Toda Kazuhiro

    2012-02-01

    Full Text Available Abstract Background The spindle assembly checkpoint (SAC inhibits anaphase progression in the presence of insufficient kinetochore-microtubule attachments, but cells can eventually override mitotic arrest by a process known as mitotic slippage or adaptation. This is a problem for cancer chemotherapy using microtubule poisons. Results Here we describe mitotic slippage in yeast bub2Δ mutant cells that are defective in the repression of precocious telophase onset (mitotic exit. Precocious activation of anaphase promoting complex/cyclosome (APC/C-Cdh1 caused mitotic slippage in the presence of nocodazole, while the SAC was still active. APC/C-Cdh1, but not APC/C-Cdc20, triggered anaphase progression (securin degradation, separase-mediated cohesin cleavage, sister-chromatid separation and chromosome missegregation, in addition to telophase onset (mitotic exit, during mitotic slippage. This demonstrates that an inhibitory system not only of APC/C-Cdc20 but also of APC/C-Cdh1 is critical for accurate chromosome segregation in the presence of insufficient kinetochore-microtubule attachments. Conclusions The sequential activation of APC/C-Cdc20 to APC/C-Cdh1 during mitosis is central to accurate mitosis. Precocious activation of APC/C-Cdh1 in metaphase (pre-anaphase causes mitotic slippage in SAC-activated cells. For the prevention of mitotic slippage, concomitant inhibition of APC/C-Cdh1 may be effective for tumor therapy with mitotic spindle poisons in humans.

  4. lemmingA encodes the Apc11 subunit of the APC/C in Drosophila melanogaster that forms a ternary complex with the E2-C type ubiquitin conjugating enzyme, Vihar and Morula/Apc2

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    Nagy Olga

    2012-03-01

    Full Text Available Abstract Background Ubiquitin-dependent protein degradation is a critical step in key cell cycle events, such as metaphase-anaphase transition and mitotic exit. The anaphase promoting complex/cyclosome (APC/C plays a pivotal role in these transitions by recognizing and marking regulatory proteins for proteasomal degradation. Its overall structure and function has been elucidated mostly in yeasts and mammalian cell lines. The APC/C is, however, a multisubunit assembly with at least 13 subunits and their function and interaction within the complex is still relatively uncharacterized, particularly in metazoan systems. Here, lemming (lmg mutants were used to study the APC/C subunit, Apc11, and its interaction partners in Drosophila melanogaster. Results The lmg gene was initially identified through a pharate adult lethal P element insertion mutation expressing developmental abnormalities and widespread apoptosis in larval imaginal discs and pupal abdominal histoblasts. Larval neuroblasts were observed to arrest mitosis in a metaphase-like state with highly condensed, scattered chromosomes and frequent polyploidy. These neuroblasts contain high levels of both cyclin A and cyclin B. The lmg gene was cloned by virtue of the lmg03424 P element insertion which is located in the 5' untranslated region. The lemming locus is transcribed to give a 2.0 kb mRNA that contains two ORFs, lmgA and lmgB. The lmgA ORF codes for a putative protein with more than 80% sequence homology to the APC11 subunit of the human APC/C. The 85 amino acid protein also contains a RING-finger motif characteristic of known APC11 subunits. The lmgA ORF alone was sufficient to rescue the lethal and mitotic phenotypes of the lmg138 null allele and to complement the temperature sensitive lethal phenotype of the APC11-myc9 budding yeast mutant. The LmgA protein interacts with Mr/Apc2, and they together form a binding site for Vihar, the E2-C type ubiquitin conjugating enzyme. Despite

  5. Mutant human myocilin induces strain specific differences in ocular hypertension and optic nerve damage in mice.

    Science.gov (United States)

    McDowell, Colleen M; Luan, Tomi; Zhang, Zhang; Putliwala, Tasneem; Wordinger, Robert J; Millar, J Cameron; John, Simon W M; Pang, Iok-Hou; Clark, Abbot F

    2012-07-01

    Elevated intraocular pressure (IOP) is a causative risk factor for the development and progression of glaucoma. Glaucomatous mutations in myocilin (MYOC) damage the trabecular meshwork and elevate IOP in humans and in mice. Animal models of glaucoma are important to discover and better understand molecular pathogenic pathways and to test new glaucoma therapeutics. Although a number of different animal models of glaucoma have been developed and characterized, there are no true models of human primary open angle glaucoma (POAG). The overall goal of this work is to develop the first inducible mouse model of POAG using a human POAG relevant transgene (i.e. mutant MYOC) expression in mouse eyes to elevate IOP and cause pressure-induced damage to the optic nerve. Four mouse strains (A/J, BALB/cJ, C57BL/6J, and C3H/HeJ) were used in this study. Ad5.MYOC.Y437H (5 × 10(7) pfu) was injected intravitreally into one eye, with the uninjected contralateral eye serving as the control eye. Conscious IOP measurements were taken using a TonoLab rebound tonometer. Optic nerve damage was determined by scoring PPD stained optic nerve cross sections. Retinal ganglion cell and superior colliculus damage was assessed by Nissl stain cell counts. Intravitreal administration of viral vector Ad5.MYOC.Y437H caused a prolonged, reproducible, and statistically significant IOP elevation in BALB/cJ, A/J, and C57BL/6J mice. IOPs increased to approximately 25 mm Hg for 8 weeks (p death or superior colliculus damage at the 8-week time point in any of the strains tested. These results demonstrate strain dependent responses to Ad5.MYOC.Y437H-induced ocular hypertension and pressure-induced optic nerve damage. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Mice mutant in the DM domain gene Dmrt4 are viable and fertile but have polyovular follicles.

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    Balciuniene, Jorune; Bardwell, Vivian J; Zarkower, David

    2006-12-01

    Proteins containing the DM domain, a zinc finger-like DNA binding motif, have been implicated in sexual differentiation in diverse metazoan organisms. Of seven mammalian DM domain genes, only Dmrt1 and Dmrt2 have been functionally analyzed. Here, we report expression analysis and targeted disruption of Dmrt4 (also called DmrtA1) in the mouse. Dmrt4 is widely expressed during embryonic and postnatal development. However, we find that mice homozygous for a putative null mutation in Dmrt4 develop essentially normally, undergo full sexual differentiation in both sexes, and are fertile. We observed two potential mutant phenotypes in Dmrt4 mutant mice. First, ovaries of most mutant females have polyovular follicles, suggesting a role in folliculogenesis. Second, 25% of mutant males consistently exhibited copulatory behavior toward other males. We also tested potential redundancy between Dmrt4 and two other gonadally expressed DM domain genes, Dmrt1 and Dmrt7. We observed no enhancement of gonadal phenotypes in the double mutants, suggesting that these genes function independently in gonadal development.

  7. Toll-like receptor 4 mutant and null mice retain morphine-induced tolerance, hyperalgesia, and physical dependence.

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    Theresa Alexandra Mattioli

    Full Text Available The innate immune system modulates opioid-induced effects within the central nervous system and one target that has received considerable attention is the toll-like receptor 4 (TLR4. Here, we examined the contribution of TLR4 in the development of morphine tolerance, hyperalgesia, and physical dependence in two inbred mouse strains: C3H/HeJ mice which have a dominant negative point mutation in the Tlr4 gene rendering the receptor non-functional, and B10ScNJ mice which are TLR4 null mutants. We found that neither acute antinociceptive response to a single dose of morphine, nor the development of analgesic tolerance to repeated morphine treatment, was affected by TLR4 genotype. Likewise, opioid induced hyperalgesia and opioid physical dependence (assessed by naloxone precipitated withdrawal were not altered in TLR4 mutant or null mice. We also examined the behavioural consequence of two stereoisomers of naloxone: (- naloxone, an opioid receptor antagonist, and (+ naloxone, a purported antagonist of TLR4. Both stereoisomers of naloxone suppressed opioid induced hyperalgesia in wild-type control, TLR4 mutant, and TLR4 null mice. Collectively, our data suggest that TLR4 is not required for opioid-induced analgesic tolerance, hyperalgesia, or physical dependence.

  8. Agenesis of the Corpus Callosum Due to Defective Glial Wedge Formation in Lhx2 Mutant Mice.

    Science.gov (United States)

    Chinn, Gregory A; Hirokawa, Karla E; Chuang, Tony M; Urbina, Cecilia; Patel, Fenil; Fong, Jeanette; Funatsu, Nobuo; Monuki, Edwin S

    2015-09-01

    Establishment of the corpus callosum involves coordination between callosal projection neurons and multiple midline structures, including the glial wedge (GW) rostrally and hippocampal commissure caudally. GW defects have been associated with agenesis of the corpus callosum (ACC). Here we show that conditional Lhx2 inactivation in cortical radial glia using Emx1-Cre or Nestin-Cre drivers results in ACC. The ACC phenotype was characterized by aberrant ventrally projecting callosal axons rather than Probst bundles, and was 100% penetrant on 2 different mouse strain backgrounds. Lhx2 inactivation in postmitotic cortical neurons using Nex-Cre mice did not result in ACC, suggesting that the mutant phenotype was not autonomous to the callosal projection neurons. Instead, ACC was associated with an absent hippocampal commissure and a markedly reduced to absent GW. Expression studies demonstrated strong Lhx2 expression in the normal GW and in its radial glial progenitors, with absence of Lhx2 resulting in normal Emx1 and Sox2 expression, but premature exit from the cell cycle based on EdU-Ki67 double labeling. These studies define essential roles for Lhx2 in GW, hippocampal commissure, and corpus callosum formation, and suggest that defects in radial GW progenitors can give rise to ACC.

  9. Altered expression of neuropeptides in FoxG1-null heterozygous mutant mice.

    Science.gov (United States)

    Frullanti, Elisa; Amabile, Sonia; Lolli, Maria Grazia; Bartolini, Anna; Livide, Gabriella; Landucci, Elisa; Mari, Francesca; Vaccarino, Flora M; Ariani, Francesca; Massimino, Luca; Renieri, Alessandra; Meloni, Ilaria

    2016-02-01

    Foxg1 gene encodes for a transcription factor essential for telencephalon development in the embryonic mammalian forebrain. Its complete absence is embryonic lethal while Foxg1 heterozygous mice are viable but display microcephaly, altered hippocampal neurogenesis and behavioral and cognitive deficiencies. In order to evaluate the effects of Foxg1 alteration in adult brain, we performed expression profiling in total brains from Foxg1+/- heterozygous mutants and wild-type littermates. We identified statistically significant differences in expression levels for 466 transcripts (Pneuropeptides have an important role in maternal and social behavior, and their alteration is associated with impaired social interaction and autistic behavior. In addition, Neuronatin (Nnat) levels appear significantly higher both in Foxg1+/- whole brain and in hippocampal neurons after silencing Foxg1, strongly suggesting that it is directly or indirectly repressed by Foxg1. During fetal and neonatal brain development, Nnat may regulate neuronal excitability, receptor trafficking and calcium-dependent signaling and, in the adult brain, it is predominantly expressed in parvalbumin-positive GABAergic interneurons. Overall, these results implicate the overexpression of a group of neuropeptides in the basal ganglia, hypothalamus, cortex and hippocampus in the pathogenesis FOXG1 behavioral impairments.

  10. Unraveling the complexity of amyotrophic lateral sclerosis: recent advances from the transgenic mutant SOD1 mice.

    Science.gov (United States)

    Peviani, M; Caron, I; Pizzasegola, C; Gensano, F; Tortarolo, M; Bendotti, C

    2010-08-01

    Amyotrophic Lateral Sclerosis (ALS), which accounts for the majority of motor neuron disorders, is a progressive and fatal neurodegenerative disease leading to complete paralysis of skeletal muscles and premature death usually from respiratory failure. About 10% of all ALS cases are inherited, with the responsible gene having been identified in approximately 25% of these individuals. Mutations in the copper-zinc superoxide dismutase (SOD1) gene were the first to be recognized nearly twenty years ago, and since then different animal models, in particular transgenic rodents, have been developed. They replicate many of the clinical, neuropathological and molecular features of ALS patients and have contributed significantly to our understanding of the pathogenic mechanisms of this disease. Although results obtained so far with mutant SOD1 mice have not translated into effective therapies in ALS patients, these models still represent the only experimentally accessible system to study multiple aspects of disease pathogenesis and to provide proof-of-principle for the development of new therapeutic strategies. This review will examine the most recent discoveries obtained from these animal models in an attempt to elucidate the complex mechanisms of the disease. In particular it will focus on the contribution of multiple cell types in governing the disease development and progression.

  11. CEP-1347 reduces mutant huntingtin-associated neurotoxicity and restores BDNF levels in R6/2 mice.

    Science.gov (United States)

    Apostol, Barbara L; Simmons, Danielle A; Zuccato, Chiara; Illes, Katalin; Pallos, Judit; Casale, Malcolm; Conforti, Paola; Ramos, Catarina; Roarke, Margaret; Kathuria, Satish; Cattaneo, Elena; Marsh, J Lawrence; Thompson, Leslie Michels

    2008-09-01

    Huntington's disease (HD) is a devastating neurodegenerative disorder caused by an expanded polyglutamine repeat within the protein Huntingtin (Htt). We previously reported that mutant Htt expression activates the ERK1/2 and JNK pathways [Apostol, B.L., Illes, K., Pallos, J., Bodai, L., Wu, J., Strand, A., Schweitzer, E.S., Olson, J.M., Kazantsev, A., Marsh, J.L., Thompson, L.M., 2006. Mutant huntingtin alters MAPK signaling pathways in PC12 and striatal cells: ERK1/2 protects against mutant huntingtin-associated toxicity. Hum. Mol. Genet. 15, 273-285]. Chemical and genetic modulation of these pathways promotes cell survival and death, respectively. Here we test the ability of two closely related compounds, CEP-11004 and CEP-1347, which inhibit Mixed Lineage Kinases (MLKs) and are neuroprotective, to suppress mutant Htt-mediated pathogenesis in multiple model systems. CEP-11004/CEP-1347 treatment significantly decreased toxicity in mutant Htt-expressing cells that evoke a strong JNK response. However, suppression of cellular dysfunction in cell lines that exhibit only mild Htt-associated toxicity and little JNK activation was associated with activation of ERK1/2. These compounds also reduced neurotoxicity in immortalized striatal neurons from mutant knock-in mice and Drosophila expressing a mutant Htt fragment. Finally, CEP-1347 improved motor performance in R6/2 mice and restored expression of BDNF, a critical neurotrophic factor that is reduced in HD. These studies suggest a novel therapeutic approach for a currently untreatable neurodegenerative disease, HD, via CEP-1347 up-regulation of BDNF.

  12. Are Sema5a mutant mice a good model of autism? A behavioral analysis of sensory systems, emotionality and cognition.

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    Gunn, Rhian K; Huentelman, Matthew J; Brown, Richard E

    2011-11-20

    Semaphorin 5A (Sema5A) expression is reduced in the brain of individuals with autism, thus mice with reduced Sema5A levels may serve as a model of this neurodevelopmental disorder. We tested male and female Sema5a knockout mice (B6.129P2SEMA5A()/J) and C57BL/6J controls for emotionality, visual ability, prepulse inhibition, motor learning and cognition. Overall, there were only two genotype differences in emotionality: Sema5a mutant mice had more stretch-attend postures in the elevated plus-maze and more defecations in the open field. All mice could see, but Sema5a mice had better visual ability than C57BL/6J mice. There were no genotype differences in sensory-motor gating. Sema5a mice showed higher levels of activity in the elevated plus-maze and light/dark transition box, and there were sex by genotype differences in the Rotarod, suggesting a sex difference in balance and coordination differentially affected by Sema5a. There were no genotype effects on cognition: Sema5a mice did not differ from C57BL/6J in the Morris water maze, set-shifting or cued and contextual fear conditioning. In the social recognition test, all mice preferred social stimuli, but there was no preference for social novelty, thus the Sema5A mice do not have a deficit in social behavior. Overall, there were a number of sex differences, with females showing greater activity and males performing better in tests of spatial learning and memory, but no deficits in the behavior of Sema5A mice. We conclude that the Sema5a mice do not meet the behavioral criteria for a mouse model of autism. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. MASTR: A Technique for Mosaic Mutant Analysis with Spatial and Temporal Control of Recombination Using Conditional Floxed Alleles in Mice

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    Zhimin Lao

    2012-08-01

    Full Text Available Mosaic mutant analysis, the study of cellular defects in scattered mutant cells in a wild-type environment, is a powerful approach for identifying critical functions of genes and has been applied extensively to invertebrate model organisms. A highly versatile technique has been developed in mouse: MASTR (mosaic mutant analysis with spatial and temporal control of recombination, which utilizes the increasing number of floxed alleles and simultaneously combines conditional gene mutagenesis and cell marking for fate analysis. A targeted allele (R26MASTR was engineered; the allele expresses a GFPcre fusion protein following FLP-mediated recombination, which serves the dual function of deleting floxed alleles and marking mutant cells with GFP. Within 24 hr of tamoxifen administration to R26MASTR mice carrying an inducible FlpoER transgene and a floxed allele, nearly all GFP-expressing cells have a mutant allele. The fate of single cells lacking FGF8 or SHH signaling in the developing hindbrain was analyzed using MASTR, and it was revealed that there is only a short time window when neural progenitors require FGFR1 for viability and that granule cell precursors differentiate rapidly when SMO is lost. MASTR is a powerful tool that provides cell-type-specific (spatial and temporal marking of mosaic mutant cells and is broadly applicable to developmental, cancer, and adult stem cell studies.

  14. Cyclophilin D-dependent mitochondrial permeability transition is not involved in neurodegeneration in mnd2 mutant mice.

    Science.gov (United States)

    Ideguchi, Kan; Shimizu, Shigeomi; Okumura, Meinoshin; Tsujimoto, Yoshihide

    2010-03-05

    Parkinson's disease (PD) is a common neurodegenerative disorder. The motor neuron degeneration 2 mutant (mnd2) mouse exhibits loss of striatal neurons, muscle wasting, weight loss, and death within 40days of birth, and is considered to be a useful animal model of PD. mnd2 was identified as an autosomal recessive mutation in the HtrA2/Omi gene, which encodes a mitochondrial serine protease. Omi-deficient mitochondria are more sensitive to mitochondrial permeability transition (mPT), which raises the possibility that mPT plays a role in motor neurodegeneration in mnd2 mice. Given that cyclophilin D (CypD)-deficient mitochondria are resistant to mPT, we examined whether CypD-dependent mPT is involved in the pathogenesis of neurodegenerative disorders in mnd2 mice by generating CypD-deficient mnd2 mice. Brain mitochondria isolated from CypD-deficient mnd2 mice were more resistant to Ca(2+)-induced mPT than those of mnd2 mice. However, both mnd2 mice and CypD-deficient mnd2 mice showed similar survival periods and phenotypes, including the lack of weight gain, muscle wasting, and resting tremor. Our data suggest that CypD-dependent mPT does not play a major role in neurodegeneration in mnd2 mice.

  15. Genetic mapping of Mom5, a novel modifier of Apc(Min)-induced intestinal tumorigenesis.

    Science.gov (United States)

    Oikarinen, Seija I; Cleveland, Alicia G; Cork, Karlene M; Bynoté, Kimberly K; Rafter, Joseph J; Gustafsson, Jan-Ake; Mutanen, Marja; Gould, Karen A

    2009-09-01

    The initial purpose of this study was to assess the role of estrogen receptor beta (ERbeta) in intestinal tumorigenesis by examining the effects of an ERbeta knockout (ERbeta(-/-)) on Apc(Min) mice. In order to accomplish this goal on a uniform genetic background, we were required to backcross the ERbeta knockout from the 129P2 genetic background to the B6 genetic background for 10 generations. Midway through this process, we performed a test cross in which mice from the N(5) backcross generation of the ERbeta knockout strain were intercrossed with Apc(Min/+) mice to obtain Apc(Min/+) ERbeta(+/+), Apc(Min/+) ERbeta(+/-) and Apc(Min/+) ERbeta(-/-) mice. Intestinal tumorigenesis in the N(5)F(2) mice was evaluated at 14 weeks of age. The analysis of the impact of ERbeta in the N(5) cross was complicated by segregating 129P2-derived alleles that affected tumor number and were unlinked to ERbeta. Genetic linkage analysis of this cross permitted the localization of a single genetic modifier of tumor number in Apc(Min/+) mice. This locus, Modifier of Min 5 (Mom5), maps to proximal mouse chromosome 5; the 129P2 allele of this locus is associated with a 50% reduction in mean intestinal tumor number. Through in silico analysis and confirmatory sequencing, we have identified the Rad50-interacting protein-1 gene as a strong candidate for Mom5.

  16. Brn3c null mutant mice show long-term, incomplete retention of some afferent inner ear innervation

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    Pirvola Ulla

    2003-01-01

    Full Text Available Abstract Background Ears of Brn3c null mutants develop immature hair cells, identifiable only by certain molecular markers, and undergo apoptosis in neonates. This partial development of hair cells could lead to enough neurotrophin expression to sustain sensory neurons through embryonic development. We have therefore investigated in these mutants the patterns of innervation and of expression of known neurotrophins. Results At birth there is a limited expression of BDNF and NT-3 in the mutant sensory epithelia and DiI tracing shows no specific reduction of afferents or efferents that resembles neurotrophin null mutations. At postnatal day 7/8 (P7/8, innervation is severely reduced both qualitatively and quantitatively. 1% of myosin VIIa-positive immature hair cells are present in the mutant cochlea, concentrated in the base. Around 20% of immature hair cells exist in the mutant vestibular sensory epithelia. Despite more severe loss of hair cells (1% compared to 20%, the cochlea retains many more sensory neurons (46% compared to 15% than vestibular epithelia. Even 6 months old mutant mice have some fibers to all vestibular sensory epithelia and many more to the cochlear apex which lacks MyoVIIa positive hair cells. Topologically organized central cochlea projections exist at least until P8, suggesting that functional hair cells are not required to establish such projections. Conclusion The limited expression of neurotrophins in the cochlea of Brn3c null mice suffices to support many sensory neurons, particularly in the cochlea, until birth. The molecular nature of the long term survival of apical spiral neurons remains unclear.

  17. A Yersinia pestis YscN ATPase mutant functions as a live attenuated vaccine against bubonic plague in mice.

    Science.gov (United States)

    Bozue, Joel; Cote, Christopher K; Webster, Wendy; Bassett, Anthony; Tobery, Steven; Little, Stephen; Swietnicki, Wieslaw

    2012-07-01

    Yersinia pestis is the causative agent responsible for bubonic and pneumonic plague. The bacterium uses the pLcr plasmid-encoded type III secretion system to deliver virulence factors into host cells. Delivery requires ATP hydrolysis by the YscN ATPase encoded by the yscN gene also on pLcr. A yscN mutant was constructed in the fully virulent CO92 strain containing a nonpolar, in-frame internal deletion within the gene. We demonstrate that CO92 with a yscN mutation was not able to secrete the LcrV protein (V-Antigen) and attenuated in a subcutaneous model of plague demonstrating that the YscN ATPase was essential for virulence. However, if the yscN mutant was complemented with a functional yscN gene in trans, virulence was restored. To evaluate the mutant as a live vaccine, Swiss-Webster mice were vaccinated twice with the ΔyscN mutant at varying doses and were protected against bubonic plague in a dose-dependent manner. Antibodies to F1 capsule but not to LcrV were detected in sera from the vaccinated mice. These preliminary results suggest a proof-of-concept for an attenuated, genetically engineered, live vaccine effective against bubonic plague. Published 2012. This article is a US Government work and is in the public domain in the USA.

  18. Standardized, systemic phenotypic analysis of Umod(C93F and Umod(A227T mutant mice.

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    Elisabeth Kemter

    Full Text Available Uromodulin-associated kidney disease (UAKD summarizes different clinical features of an autosomal dominant heritable disease syndrome in humans with a proven uromodulin (UMOD mutation involved. It is often characterized by hyperuricemia, gout, alteration of urine concentrating ability, as well as a variable rate of disease progression inconstantly leading to renal failure and histological alterations of the kidneys. We recently established the two Umod mutant mouse lines Umod(C93F and Umod(A227T on the C3H inbred genetic background both showing kidney defects analogous to those found in human UAKD patients. In addition, disease symptoms were revealed that were not yet described in other published mouse models of UAKD. To examine if further organ systems and/or metabolic pathways are affected by Umod mutations as primary or secondary effects, we describe a standardized, systemic phenotypic analysis of the two mutant mouse lines Umod(A227T and Umod(C93F in the German Mouse Clinic. Different genotypes as well as different ages were tested. Beside the already published changes in body weight, body composition and bone metabolism, the influence of the Umod mutation on energy metabolism was confirmed. Hematological analysis revealed a moderate microcytic and erythropenic anemia in older Umod mutant mice. Data of the other analyses in 7-10 month-old mutant mice showed single small additional effects.

  19. Elevated Fibroblast Growth Factor Signaling Is Critical for the Pathogenesis of the Dwarfism in Evc2/Limbin Mutant Mice.

    Science.gov (United States)

    Zhang, Honghao; Kamiya, Nobuhiro; Tsuji, Takehito; Takeda, Haruko; Scott, Greg; Rajderkar, Sudha; Ray, Manas K; Mochida, Yoshiyuki; Allen, Benjamin; Lefebvre, Veronique; Hung, Irene H; Ornitz, David M; Kunieda, Tetsuo; Mishina, Yuji

    2016-12-01

    Ellis-van Creveld (EvC) syndrome is a skeletal dysplasia, characterized by short limbs, postaxial polydactyly, and dental abnormalities. EvC syndrome is also categorized as a ciliopathy because of ciliary localization of proteins encoded by the two causative genes, EVC and EVC2 (aka LIMBIN). While recent studies demonstrated important roles for EVC/EVC2 in Hedgehog signaling, there is still little known about the pathophysiological mechanisms underlying the skeletal dysplasia features of EvC patients, and in particular why limb development is affected, but not other aspects of organogenesis that also require Hedgehog signaling. In this report, we comprehensively analyze limb skeletogenesis in Evc2 mutant mice and in cell and tissue cultures derived from these mice. Both in vivo and in vitro data demonstrate elevated Fibroblast Growth Factor (FGF) signaling in Evc2 mutant growth plates, in addition to compromised but not abrogated Hedgehog-PTHrP feedback loop. Elevation of FGF signaling, mainly due to increased Fgf18 expression upon inactivation of Evc2 in the perichondrium, critically contributes to the pathogenesis of limb dwarfism. The limb dwarfism phenotype is partially rescued by inactivation of one allele of Fgf18 in the Evc2 mutant mice. Taken together, our data uncover a novel pathogenic mechanism to understand limb dwarfism in patients with Ellis-van Creveld syndrome.

  20. Class II major histocompatibility complex mutant mice to study the germ-line bias of T-cell antigen receptors.

    Science.gov (United States)

    Silberman, Daniel; Krovi, Sai Harsha; Tuttle, Kathryn D; Crooks, James; Reisdorph, Richard; White, Janice; Gross, James; Matsuda, Jennifer L; Gapin, Laurent; Marrack, Philippa; Kappler, John W

    2016-09-20

    The interaction of αβ T-cell antigen receptors (TCRs) with peptides bound to MHC molecules lies at the center of adaptive immunity. Whether TCRs have evolved to react with MHC or, instead, processes in the thymus involving coreceptors and other molecules select MHC-specific TCRs de novo from a random repertoire is a longstanding immunological question. Here, using nuclease-targeted mutagenesis, we address this question in vivo by generating three independent lines of knockin mice with single-amino acid mutations of conserved class II MHC amino acids that often are involved in interactions with the germ-line-encoded portions of TCRs. Although the TCR repertoire generated in these mutants is similar in size and diversity to that in WT mice, the evolutionary bias of TCRs for MHC is suggested by a shift and preferential use of some TCR subfamilies over others in mice expressing the mutant class II MHCs. Furthermore, T cells educated on these mutant MHC molecules are alloreactive to each other and to WT cells, and vice versa, suggesting strong functional differences among these repertoires. Taken together, these results highlight both the flexibility of thymic selection and the evolutionary bias of TCRs for MHC.

  1. Elevated Fibroblast Growth Factor Signaling Is Critical for the Pathogenesis of the Dwarfism in Evc2/Limbin Mutant Mice.

    Directory of Open Access Journals (Sweden)

    Honghao Zhang

    2016-12-01

    Full Text Available Ellis-van Creveld (EvC syndrome is a skeletal dysplasia, characterized by short limbs, postaxial polydactyly, and dental abnormalities. EvC syndrome is also categorized as a ciliopathy because of ciliary localization of proteins encoded by the two causative genes, EVC and EVC2 (aka LIMBIN. While recent studies demonstrated important roles for EVC/EVC2 in Hedgehog signaling, there is still little known about the pathophysiological mechanisms underlying the skeletal dysplasia features of EvC patients, and in particular why limb development is affected, but not other aspects of organogenesis that also require Hedgehog signaling. In this report, we comprehensively analyze limb skeletogenesis in Evc2 mutant mice and in cell and tissue cultures derived from these mice. Both in vivo and in vitro data demonstrate elevated Fibroblast Growth Factor (FGF signaling in Evc2 mutant growth plates, in addition to compromised but not abrogated Hedgehog-PTHrP feedback loop. Elevation of FGF signaling, mainly due to increased Fgf18 expression upon inactivation of Evc2 in the perichondrium, critically contributes to the pathogenesis of limb dwarfism. The limb dwarfism phenotype is partially rescued by inactivation of one allele of Fgf18 in the Evc2 mutant mice. Taken together, our data uncover a novel pathogenic mechanism to understand limb dwarfism in patients with Ellis-van Creveld syndrome.

  2. Huperzine A provides robust and sustained protection against induced seizures in Scn1a mutant mice

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    Jennifer C. Wong

    2016-10-01

    Full Text Available De novo loss-of-function mutations in the voltage-gated sodium channel (VGSC SCN1A (encoding Nav1.1 are the main cause of Dravet syndrome (DS, a catastrophic early-life encephalopathy associated with prolonged and recurrent early-life febrile seizures (FSs, refractory afebrile epilepsy, cognitive and behavioral deficits, and a 15-20% mortality rate. SCN1A mutations also lead to genetic epilepsy with febrile seizures plus (GEFS+, which is an inherited disorder characterized by early-life FSs and the development of a range of adult epilepsy subtypes. Current antiepileptic drugs often fail to protect against the severe seizures and behavioral and cognitive deficits found in patients with SCN1A mutations. To address the need for more efficacious treatments for SCN1A-derived epilepsies, we evaluated the therapeutic potential of Huperzine A, a naturally occurring reversible acetylcholinesterase inhibitor. In CF1 mice, Hup A (0.56 or 1 mg/kg was found to confer protection against 6 Hz-, pentylenetetrazole (PTZ-, and maximal electroshock (MES-induced seizures. Robust protection against 6 Hz-, MES-, and hyperthermia-induced seizures was also achieved following Hup A administration in mouse models of DS (Scn1a+/- and GEFS+ (Scn1aRH/+. Furthermore, Hup A-mediated seizure protection was sustained during 3 weeks of daily injections in Scn1aRH/+ mutants. Finally, we determined that the muscarinic and GABAA receptors play a role in Hup A-mediated seizure protection. These findings indicate that Hup A might provide a novel therapeutic strategy for increasing seizure resistance in DS and GEFS+, and more broadly, in other forms of refractory epilepsy.

  3. Protective and therapeutic effects of the resuscitation-promoting factor domain and its mutants against Mycobacterium tuberculosis in mice.

    Science.gov (United States)

    Zhao, Shanmin; Song, Xiaoqin; Zhao, Yong; Qiu, Yi; Mao, Fengfeng; Zhang, Caiqin; Bai, Bing; Zhang, Hai; Wu, Shaoping; Shi, Changhong

    2015-04-01

    The resuscitation-promoting factor (Rpf), a secretory protein first reported in Micrococcus luteus, plays a critical role in mycobacterial survival and infection. There are five functionally redundant Rpf-like proteins identified in M. tuberculosis (Mtb). All these Rpfs share a conserved Rpf domain (Rpfd) composed of approximately 70 amino acids, which possesses the same biological functions as the full-length Rpf protein. Glutamic acid at position 54 in Rpfd (E54) has been implicated in mediating multiple physiological processes, and a single amino acid substitution at residue E54 can affect the protein biological activity. In order to determine the effects of different amino acid substitutions of E54 in Rpfd on its immunogenic activity, we generated three recombinant Rpfd mutants, Rpfd1 (E54K), Rpfd2 (E54A) and Rpfd3 (E54K and D48A), based on T-cell epitope prediction and tested their potential protective/therapeutic effects against Mtb in mice. Our results demonstrated that replacement of E54 by different amino acids in Rpfd distinctively influenced its resuscitation-promoting activities and Th1-type immune responses induced in mice. Administration of Rpfd2 mutant enhanced Th1-type cellular responses (IFN-γ and IL-2) in mice (P < 0.05, Rpfd2 versus control) and provided effective protection against Mtb in mice by significantly inhibiting the growth of Mtb during the initial stage of infection. Four weeks after the challenge, the slightest pathological injury in lung was observed in the Rpfd2-immunized group among all three Rfpd mutant-immunized groups. Furthermore, Rpfd2 therapy significantly decreased the bacterial load in lung and alleviated histopathological damage in Mtb-infected mice. Together, our results suggest Rpfd2 as a novel effective vaccine candidate against Mtb.

  4. Searching for biomarkers of CDKL5 disorder: early-onset visual impairment in CDKL5 mutant mice.

    Science.gov (United States)

    Mazziotti, Raffaele; Lupori, Leonardo; Sagona, Giulia; Gennaro, Mariangela; Della Sala, Grazia; Putignano, Elena; Pizzorusso, Tommaso

    2017-06-15

    CDKL5 disorder is a neurodevelopmental disorder still without a cure. Murine models of CDKL5 disorder have been recently generated raising the possibility of preclinical testing of treatments. However, unbiased, quantitative biomarkers of high translational value to monitor brain function are still missing. Moreover, the analysis of treatment is hindered by the challenge of repeatedly and non-invasively testing neuronal function. We analyzed the development of visual responses in a mouse model of CDKL5 disorder to introduce visually evoked responses as a quantitative method to assess cortical circuit function. Cortical visual responses were assessed in CDKL5 null male mice, heterozygous females, and their respective control wild-type littermates by repeated transcranial optical imaging from P27 until P32. No difference between wild-type and mutant mice was present at P25-P26 whereas defective responses appeared from P27-P28 both in heterozygous and homozygous CDKL5 mutant mice. These results were confirmed by visually evoked potentials (VEPs) recorded from the visual cortex of a different cohort. The previously imaged mice were also analyzed at P60-80 using VEPs, revealing a persistent reduction of response amplitude, reduced visual acuity and defective contrast function. The level of adult impairment was significantly correlated with the reduction in visual responses observed during development. Support vector machine showed that multi-dimensional visual assessment can be used to automatically classify mutant and wt mice with high reliability. Thus, monitoring visual responses represents a promising biomarker for preclinical and clinical studies on CDKL5 disorder. © The Author 2017. Published by Oxford University Press.

  5. Decreased MHC I expression in IFN gamma mutant mice alters synaptic elimination in the spinal cord after peripheral injury

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    Victório Sheila CS

    2012-05-01

    Full Text Available Abstract Background The histocompatibility complex (MHC class I expression in the central nervous system (CNS regulates synaptic plasticity events during development and adult life. Its upregulation may be associated with events such as axotomy, cytokine exposition and changes in neuron electrical activity. Since IFNγ is a potent inducer of the MHC I expression, the present work investigated the importance of this pro-inflammatory cytokine in the synaptic elimination process in the spinal cord, as well as the motor recovery of IFN−/−, following peripheral injury. Methods The lumbar spinal cords of C57BL/6J (wild type and IFNγ−/− (mutant mice, subjected to unilateral sciatic nerve transection, were removed and processed for immunohistochemistry and real time RT-PCR, while the sciatic nerves from animals subjected to unilateral crush, were submitted to immunohistochemistry and electron microscopy for counting of the axons. Gait recovery was monitored using the Cat Walk system. Newborn mice astrocyte primary cultures were established in order to study the astrocytic respose in the absence of the IFNγ expression. Results IFNγ−/− mutant mice showed a decreased expression of MHC I and β2-microglobulin mRNA coupled with reduced synaptophysin immunolabelling in the lesioned spinal cord segment. Following unilateral nerve transection, the Iba-1 (ionized calcium binding adaptor molecule 1 and glial fibrillary acid protein (GFAP reactivities increased equally in both strains. In vitro, the astrocytes demonstrated similar GFAP levels, but the proliferation rate was higher in the wild type mice. In the crushed nerves (distal stump, neurofilaments and p75NTR immunolabeling were upregulated in the mutant mice as compared to the wild type and an improvement in locomotor recovery was observed. Conclusion The present results show that a lack of IFNγ affects the MHC I expression and the synaptic elimination process in the spinal cord. Such

  6. Kharon1 null mutants of Leishmania mexicana are avirulent in mice and exhibit a cytokinesis defect within macrophages.

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    Khoa D Tran

    Full Text Available In a variety of eukaryotes, flagella play important roles both in motility and as sensory organelles that monitor the extracellular environment. In the parasitic protozoan Leishmania mexicana, one glucose transporter isoform, LmxGT1, is targeted selectively to the flagellar membrane where it appears to play a role in glucose sensing. Trafficking of LmxGT1 to the flagellar membrane is dependent upon interaction with the KHARON1 protein that is located at the base of the flagellar axoneme. Remarkably, while Δkharon1 null mutants are viable as insect stage promastigotes, they are unable to survive as amastigotes inside host macrophages. Although Δkharon1 promastigotes enter macrophages and transform into amastigotes, these intracellular parasites are unable to execute cytokinesis and form multinucleate cells before dying. Notably, extracellular axenic amastigotes of Δkharon1 mutants replicate and divide normally, indicating a defect in the mutants that is only exhibited in the intra-macrophage environment. Although the flagella of Δkharon1 amastigotes adhere to the phagolysomal membrane of host macrophages, the morphology of the mutant flagella is often distorted. Additionally, these null mutants are completely avirulent following injection into BALB/c mice, underscoring the critical role of the KHARON1 protein for viability of intracellular amastigotes and disease in the animal model of leishmaniasis.

  7. Dopaminergic neuronal loss, reduced neurite complexity and autophagic abnormalities in transgenic mice expressing G2019S mutant LRRK2.

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    David Ramonet

    Full Text Available Mutations in the leucine-rich repeat kinase 2 (LRRK2 gene cause late-onset, autosomal dominant familial Parkinson's disease (PD and also contribute to idiopathic PD. LRRK2 mutations represent the most common cause of PD with clinical and neurochemical features that are largely indistinguishable from idiopathic disease. Currently, transgenic mice expressing wild-type or disease-causing mutants of LRRK2 have failed to produce overt neurodegeneration, although abnormalities in nigrostriatal dopaminergic neurotransmission have been observed. Here, we describe the development and characterization of transgenic mice expressing human LRRK2 bearing the familial PD mutations, R1441C and G2019S. Our study demonstrates that expression of G2019S mutant LRRK2 induces the degeneration of nigrostriatal pathway dopaminergic neurons in an age-dependent manner. In addition, we observe autophagic and mitochondrial abnormalities in the brains of aged G2019S LRRK2 mice and markedly reduced neurite complexity of cultured dopaminergic neurons. These new LRRK2 transgenic mice will provide important tools for understanding the mechanism(s through which familial mutations precipitate neuronal degeneration and PD.

  8. Dopaminergic Neuronal Loss, Reduced Neurite Complexity and Autophagic Abnormalities in Transgenic Mice Expressing G2019S Mutant LRRK2

    Science.gov (United States)

    Lin, Brian M.; Stafa, Klodjan; Kim, Jaekwang; Banerjee, Rebecca; Westerlund, Marie; Pletnikova, Olga; Glauser, Liliane; Yang, Lichuan; Liu, Ying; Swing, Deborah A.; Beal, M. Flint; Troncoso, Juan C.; McCaffery, J. Michael; Jenkins, Nancy A.; Copeland, Neal G.; Galter, Dagmar; Thomas, Bobby; Lee, Michael K.; Dawson, Ted M.; Dawson, Valina L.; Moore, Darren J.

    2011-01-01

    Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene cause late-onset, autosomal dominant familial Parkinson's disease (PD) and also contribute to idiopathic PD. LRRK2 mutations represent the most common cause of PD with clinical and neurochemical features that are largely indistinguishable from idiopathic disease. Currently, transgenic mice expressing wild-type or disease-causing mutants of LRRK2 have failed to produce overt neurodegeneration, although abnormalities in nigrostriatal dopaminergic neurotransmission have been observed. Here, we describe the development and characterization of transgenic mice expressing human LRRK2 bearing the familial PD mutations, R1441C and G2019S. Our study demonstrates that expression of G2019S mutant LRRK2 induces the degeneration of nigrostriatal pathway dopaminergic neurons in an age-dependent manner. In addition, we observe autophagic and mitochondrial abnormalities in the brains of aged G2019S LRRK2 mice and markedly reduced neurite complexity of cultured dopaminergic neurons. These new LRRK2 transgenic mice will provide important tools for understanding the mechanism(s) through which familial mutations precipitate neuronal degeneration and PD. PMID:21494637

  9. Podocyte-specific overexpression of wild type or mutant trpc6 in mice is sufficient to cause glomerular disease.

    Directory of Open Access Journals (Sweden)

    Paola Krall

    Full Text Available Mutations in the TRPC6 calcium channel (Transient receptor potential channel 6 gene have been associated with familiar forms of Focal and Segmental Glomerulosclerosis (FSGS affecting children and adults. In addition, acquired glomerular diseases are associated with increased expression levels of TRPC6. However, the exact role of TRPC6 in the pathogenesis of FSGS remains to be elucidated. In this work we describe the generation and phenotypic characterization of three different transgenic mouse lines with podocyte-specific overexpression of the wild type or any of two mutant forms of Trpc6 (P111Q and E896K previously related to FSGS. Consistent with the human phenotype a non-nephrotic range of albuminuria was detectable in almost all transgenic lines. The histological analysis demonstrated that the transgenic mice developed a kidney disease similar to human FSGS. Differences of 2-3 folds in the presence of glomerular lesions were found between the non transgenic and transgenic mice expressing Trpc6 in its wild type or mutant forms specifically in podocytes. Electron microscopy of glomerulus from transgenic mice showed extensive podocyte foot process effacement. We conclude that overexpression of Trpc6 (wild type or mutated in podocytes is sufficient to cause a kidney disease consistent with FSGS. Our results contribute to reinforce the central role of podocytes in the etiology of FSGS. These mice constitute an important new model in which to study future therapies and outcomes of this complex disease.

  10. Altered cellular infiltration and cytokine levels during early Mycobacterium tuberculosis sigC mutant infection are associated with late-stage disease attenuation and milder immunopathology in mice

    Directory of Open Access Journals (Sweden)

    McMurray David N

    2008-09-01

    Full Text Available Abstract Background Mouse virulence assessments of certain Mycobacterium tuberculosis mutants have revealed an immunopathology defect in which high tissue CFU counts are observed but the tissue pathology and lethality are reduced. M. tuberculosis mutants which grow and persist in the mouse lungs, but have attenuated disease progression, have the immunopathology (imp phenotype. The antigenic properties of these strains may alter the progression of disease due to a reduction in host immune cell recruitment to the lungs resulting in disease attenuation and prolonged host survival. Results In this study we focused on the mouse immune response to one such mutant; the M. tuberculosis ΔsigC mutant. Aerosol infection of DBA/2 and SCID mice with the M. tuberculosis ΔsigC mutant, complemented mutant and wild type strain showed proliferation of mutant bacilli in mouse lungs, but with decreased inflammation and mortality in DBA/2 mice. SCID mice shared the same phenotype as the DBA/2 mice in response to the ΔsigC mutant, however, they succumbed to the infection faster. Bronchoalveolar lavage (BAL fluid analysis revealed elevated numbers of infiltrating neutrophils in the lungs of mice infected with wild type and complemented ΔsigC mutant strains but not in mice infected with the ΔsigC mutant. In addition, DBA/2 mice infected with the ΔsigC mutant had reduced levels of TNF-α, IL-1β, IL-6 and IFN-γ in the lungs. Similarly, there was a reduction in proinflammatory cytokines in the lungs of SCID mice. In contrast to the mouse model, the ΔsigC mutant had reduced initial growth in guinea pig lungs. A possible mechanism of attenuation in the ΔsigC mutant may be a reduction in neutrophilic-influx in the alveolar spaces of the lungs, and decreased proinflammatory cytokine secretion. In contrast to mouse data, the M. tuberculosis ΔsigC mutant proliferates slowly in guinea pig lungs, a setting characterized by caseating necrosis. Conclusion Our

  11. Inhibiting p38 mitogen-activated protein kinase attenuates cerebral ischemic injury in Swedish mutant amyloid precursor protein transgenic mice

    Institute of Scientific and Technical Information of China (English)

    Liangyu Zou; Haiyan Qin; Yitao He; Heming Huang; Yi Lu; Xiaofan Chu

    2012-01-01

    Cerebral ischemia was induced using photothrombosis 1 hour after intraperitoneal injection of the p38 mitogen-activated protein kinase (MAPK) inhibitor SB239063 into Swedish mutant amyloid precursor protein (APP/SWE) transgenic and non-transgenic mice. The number of surviving neurons in the penumbra was quantified using Nissl staining, and the activity of p38 MAPKs was measured by western blotting. The number of surviving neurons in the penumbra was significantly reduced in APP/SWE transgenic mice compared with non-transgenic controls 7 days after cerebral ischemia, but the activity of p38 MAPKs was significantly elevated compared with the non-ischemic hemisphere in the APP/SWE transgenic mice. SB239063 prevented these changes. The APP/SWE mutation exacerbated ischemic brain injury, and this could be alleviated by inhibiting p38 MAPK activity.

  12. Microarray-based detection of Salmonella enterica serovar Typhimurium transposon mutants that cannot survive in macrophages and mice.

    Science.gov (United States)

    Chan, Kaman; Kim, Charles C; Falkow, Stanley

    2005-09-01

    DNA microarrays provide an opportunity to combine the principles of signature-tagged mutagenesis (STM) with microarray technology to identify potentially important bacterial virulence genes. The scope of DNA microarrays allows for less laborious screening on a much larger scale than possible by STM alone. We have adapted a microarray-based transposon tracking strategy for use with a Salmonella enterica serovar Typhimurium cDNA microarray in order to identify genes important for survival and replication in RAW 264.7 mouse macrophage-like cells or in the spleens of BALB/cJ mice. A 50,000-CFU transposon library of S. enterica serovar Typhimurium strain SL1344 was serially passaged in cultured macrophages or intraperitoneally inoculated into BALB/cJ mice. The bacterial genomic DNA was isolated and processed for analysis on the microarray. The novel application of this approach to identify mutants unable to survive in cultured cells resulted in the identification of components of Salmonella pathogenicity island 2 (SPI2), which is known to be critical for intracellular survival and replication. In addition, array results indicated that a number of SPI1-associated genes, currently not associated with intracellular survival, are negatively selected. However, of the SPI1-associated mutants individually tested for intracellular survival, only a sirA mutant exhibited reduced numbers relative to those of wild-type bacteria. Of the mutants unable to survive in mice, significant proportions are either components of the SPI2 pathogenicity island or involved in lipopolysaccharide synthesis. This observation is in agreement with results obtained in the original S. enterica serovar Typhimurium STM screen, illustrating the utility of this approach for the high-throughput identification of virulence factors important for survival in the host.

  13. Locomotor and oculomotor impairment associated with cerebellar dysgenesis in Zic3-deficient (Bent tail) mutant mice.

    NARCIS (Netherlands)

    Aruga, J.; Ogura, H.; Shutoh, F.; Ogawa, M.; Franke, B.; Nagao, S.; Mikoshiba, K.

    2004-01-01

    We examined the adult neural phenotypes of the Bent tail mutant mouse. The Bent tail mutant mouse was recently shown to lack a submicroscopic part of the X chromosome containing the Zic3 gene, which encodes a zinc-finger protein controlling vertebrate neural development. While nearly one-fourth of

  14. Role of GIRK channels on the noradrenergic transmission in vivo: an electrophysiological and neurochemical study on GIRK2 mutant mice.

    Science.gov (United States)

    Torrecilla, María; Fernández-Aedo, Irrintzi; Arrue, Aurora; Zumarraga, Mercedes; Ugedo, Luisa

    2013-06-01

    Dysfunctional noradrenergic transmission is related to several neuropsychiatric conditions, such as depression. Nowadays, the role of G protein-coupled inwardly rectifying potassium (GIRK)2 subunit containing GIRK channels controlling neuronal intrinsic excitability in vitro is well known. The aim of this study was to investigate the impact of GIRK2 subunit mutation on the central noradrenergic transmission in vivo. For that purpose, single-unit extracellular activity of locus coeruleus (LC) noradrenergic neurons and brain monoamine levels using the HPLC technique were measured in wild-type and GIRK2 mutant mice. Girk2 gene mutation induced significant differences among genotypes regarding burst activity of LC neurons. In fact, the proportion of neurons displaying burst firing was increased in GIRK2 heterozygous mice as compared to that recorded from wild-type mice. Furthermore, this augmentation was even greater in the homozygous genotype. However, neither the basal firing rate nor the coefficient of variation of LC neurons was different among genotypes. Noradrenaline and serotonin basal levels were altered in the dorsal raphe nucleus from GIRK2 heterozygous and homozygous mice, respectively. Furthermore, noradrenaline levels were increased in LC projecting areas such as the hippocampus and amygdale from homozygous mice, although not in the prefrontal cortex. Finally, potency of clonidine and morphine inhibiting LC activity was reduced in GIRK2 mutant mice, although the efficacy remained unchanged. Altogether, the present study supports the role of GIRK2 subunit-containing GIRK channels on the maintenance of tonic noradrenergic activity in vivo. Electric and neurochemical consequences derived from an altered GIRK2-dependent signalling could facilitate the understanding of the neurobiological basis of pathologies related to a dysfunctional monoaminergic transmission.

  15. Immunopurification of adenomatous polyposis coli (APC) proteins

    OpenAIRE

    Elliott, Kerryn L.; Catimel, Bruno; Church, Nicole L; Janine L Coates; Antony W Burgess; Layton, Meredith J.; Faux, Maree C.

    2013-01-01

    Background The adenomatous polyposis coli (APC) tumour suppressor gene encodes a 2843 residue (310 kDa) protein. APC is a multifunctional protein involved in the regulation of β-catenin/Wnt signalling, cytoskeletal dynamics and cell adhesion. APC mutations occur in most colorectal cancers and typically result in truncation of the C-terminal half of the protein. Results In order to investigate the biophysical properties of APC, we have generated a set of monoclonal antibodies which enable puri...

  16. A cerebellar learning model of vestibulo-ocular reflex adaptation in wild-type and mutant mice.

    Science.gov (United States)

    Clopath, Claudia; Badura, Aleksandra; De Zeeuw, Chris I; Brunel, Nicolas

    2014-05-21

    Mechanisms of cerebellar motor learning are still poorly understood. The standard Marr-Albus-Ito theory posits that learning involves plasticity at the parallel fiber to Purkinje cell synapses under control of the climbing fiber input, which provides an error signal as in classical supervised learning paradigms. However, a growing body of evidence challenges this theory, in that additional sites of plasticity appear to contribute to motor adaptation. Here, we consider phase-reversal training of the vestibulo-ocular reflex (VOR), a simple form of motor learning for which a large body of experimental data is available in wild-type and mutant mice, in which the excitability of granule cells or inhibition of Purkinje cells was affected in a cell-specific fashion. We present novel electrophysiological recordings of Purkinje cell activity measured in naive wild-type mice subjected to this VOR adaptation task. We then introduce a minimal model that consists of learning at the parallel fibers to Purkinje cells with the help of the climbing fibers. Although the minimal model reproduces the behavior of the wild-type animals and is analytically tractable, it fails at reproducing the behavior of mutant mice and the electrophysiology data. Therefore, we build a detailed model involving plasticity at the parallel fibers to Purkinje cells' synapse guided by climbing fibers, feedforward inhibition of Purkinje cells, and plasticity at the mossy fiber to vestibular nuclei neuron synapse. The detailed model reproduces both the behavioral and electrophysiological data of both the wild-type and mutant mice and allows for experimentally testable predictions.

  17. The role of S100a4 (Mts1) in Apc- and Smad4-driven tumour onset and progression

    DEFF Research Database (Denmark)

    Atlasi, Yaser; Noori, Rubina; Marolin, Ivana

    2016-01-01

    Introduction S100a4 is a calcium-binding protein belonging to the family of S100-proteins, highly expressed in different stromal cell types. S100A4 has been reported as a prognostic marker in colorectal cancer in association with tumour progression and metastasis. Methods In this study, we analysed...... the in vivo role of S100a4 in intestinal tumour initiation and progression using different transgenic and knockout mouse models. Results We found that genetic ablation or overexpression of S100a4 in both Apc- and Smad4-mutant mice do not affect tumour initiation in the intestinal tract. In contrast, S100a4...... epithelial overexpression in Apc1638N/+/KRASV12G mice increases the dissemination of intestinal tumour cells to the liver, in agreement with its role in tumour metastasis. Moreover, we report a novel role for S100a4 in desmoid formation where S100a4 deficiency results in a significant reduction of the tumour...

  18. Activity-dependent BDNF release and TRPC signaling is impaired in hippocampal neurons of Mecp2 mutant mice.

    Science.gov (United States)

    Li, Wei; Calfa, Gaston; Larimore, Jennifer; Pozzo-Miller, Lucas

    2012-10-16

    Dysfunction of the neurotrophin brain-derived neurotrophic factor (BDNF) is implicated in Rett syndrome (RTT), but the state of its releasable pool and downstream signaling in mice lacking methyl-CpG-binding protein-2 (Mecp2) is unknown. Here, we show that membrane currents and dendritic Ca(2+) signals evoked by recombinant BDNF or an activator of diacylglycerol (DAG)-sensitive transient receptor potential canonical (TRPC) channels are impaired in CA3 pyramidal neurons of symptomatic Mecp2 mutant mice. TRPC3 and TRPC6 mRNA and protein levels are lower in Mecp2 mutant hippocampus, and chromatin immunoprecipitation (ChIP) identified Trpc3 as a target of MeCP2 transcriptional regulation. BDNF mRNA and protein levels are also lower in Mecp2 mutant hippocampus and dentate gyrus granule cells, which is reflected in impaired activity-dependent release of endogenous BDNF estimated from TRPC currents and dendritic Ca(2+) signals in CA3 pyramidal neurons. These results identify the gene encoding TRPC3 channels as a MeCP2 target and suggest a potential therapeutic strategy to boost impaired BDNF signaling in RTT.

  19. Unique food-entrained circadian rhythm in cysteine414-alanine mutant mCRY1 transgenic mice.

    Science.gov (United States)

    Okano, Satoshi; Yasui, Akira; Hayasaka, Kiyoshi; Nakajima, Osamu

    Food availability is a potent environmental cue that directs circadian locomotor activity in rodents. Daily scheduled restricted feeding (RF), in which the food available time is restricted for several hours each day, elicits anticipatory activity. This food-anticipatory activity (FAA) is controlled by a food-entrainable oscillator (FEO) that is distinct from the suprachiasmatic nucleus (SCN), the master pacemaker in mammals. In an earlier report, we described generation of transgenic (Tg) mice ubiquitously overexpressing cysteine414-alanine mutant mCRY1. The Tg mice displayed long locomotor free-running periods (approximately 28 h) with rhythm splitting. Furthermore, their locomotor activity immediately re-adjusted to the advance of light-dark cycles (LD), suggesting some disorder in the coupling of SCN neurons. The present study examined the restricted feeding cycle (RF)-induced entrainment of locomotor activity in Tg mice in various light conditions. In LD, wild-type controls showed both FAA and LD-entrained activities. In Tg mice, almost all activity was eventually consolidated to a single bout before the feeding time. The result suggests a possibility that in Tg mice the feeding cycle dominates the LD cycle as an entrainment agent. In constant darkness (DD), wild-type mice exhibited robust free-run activity and FAA during RF. For Tg mice, only the rhythm entrained to RF was observed in DD. Furthermore, after returning to free feeding, the free-run started from the RF-entrained phase. These results suggest that the SCN of Tg mice is entrainable to RF and that the mCRY1 mutation alters the sensitivity of SCN to the cycle of nonphotic zeitgebers.

  20. Restoration of testis function in hypogonadotropic hypogonadal mice harboring a misfolded GnRHR mutant by pharmacoperone drug therapy.

    Science.gov (United States)

    Janovick, Jo Ann; Stewart, M David; Jacob, Darla; Martin, L D; Deng, Jian Min; Stewart, C Allison; Wang, Ying; Cornea, Anda; Chavali, Lakshmi; Lopez, Suhujey; Mitalipov, Shoukhrat; Kang, Eunju; Lee, Hyo-Sang; Manna, Pulak R; Stocco, Douglas M; Behringer, Richard R; Conn, P Michael

    2013-12-24

    Mutations in receptors, ion channels, and enzymes are frequently recognized by the cellular quality control system as misfolded and retained in the endoplasmic reticulum (ER) or otherwise misrouted. Retention results in loss of function at the normal site of biological activity and disease. Pharmacoperones are target-specific small molecules that diffuse into cells and serve as folding templates that enable mutant proteins to pass the criteria of the quality control system and route to their physiologic site of action. Pharmacoperones of the gonadotropin releasing hormone receptor (GnRHR) have efficacy in cell culture systems, and their cellular and biochemical mechanisms of action are known. Here, we show the efficacy of a pharmacoperone drug in a small animal model, a knock-in mouse, expressing a mutant GnRHR. This recessive mutation (GnRHR E(90)K) causes hypogonadotropic hypogonadism (failed puberty associated with low or apulsatile luteinizing hormone) in both humans and in the mouse model described. We find that pulsatile pharmacoperone therapy restores E(90)K from ER retention to the plasma membrane, concurrently with responsiveness to the endogenous natural ligand, gonadotropin releasing hormone, and an agonist that is specific for the mutant. Spermatogenesis, proteins associated with steroid transport and steroidogenesis, and androgen levels were restored in mutant male mice following pharmacoperone therapy. These results show the efficacy of pharmacoperone therapy in vivo by using physiological, molecular, genetic, endocrine and biochemical markers and optimization of pulsatile administration. We expect that this newly appreciated approach of protein rescue will benefit other disorders sharing pathologies based on misrouting of misfolded protein mutants.

  1. The Parvalbumin/Somatostatin Ratio Is Increased in Pten Mutant Mice and by Human PTEN ASD Alleles

    Directory of Open Access Journals (Sweden)

    Daniel Vogt

    2015-05-01

    Full Text Available Mutations in the phosphatase PTEN are strongly implicated in autism spectrum disorder (ASD. Here, we investigate the function of Pten in cortical GABAergic neurons using conditional mutagenesis in mice. Loss of Pten results in a preferential loss of SST+ interneurons, which increases the ratio of parvalbumin/somatostatin (PV/SST interneurons, ectopic PV+ projections in layer I, and inhibition onto glutamatergic cortical neurons. Pten mutant mice exhibit deficits in social behavior and changes in electroencephalogram (EEG power. Using medial ganglionic eminence (MGE transplantation, we test for cell-autonomous functional differences between human PTEN wild-type (WT and ASD alleles. The PTEN ASD alleles are hypomorphic in regulating cell size and the PV/SST ratio in comparison to WT PTEN. This MGE transplantation/complementation assay is efficient and is generally applicable for functional testing of ASD alleles in vivo.

  2. Nuclear Expression of a Mitochondrial DNA Gene: Mitochondrial Targeting of Allotopically Expressed Mutant ATP6 in Transgenic Mice

    Directory of Open Access Journals (Sweden)

    David A. Dunn

    2012-01-01

    Full Text Available Nuclear encoding of mitochondrial DNA transgenes followed by mitochondrial targeting of the expressed proteins (allotopic expression; AE represents a potentially powerful strategy for creating animal models of mtDNA disease. Mice were created that allotopically express either a mutant (A6M or wildtype (A6W mt-Atp6 transgene. Compared to non-transgenic controls, A6M mice displayed neuromuscular and motor deficiencies (wire hang, pole, and balance beam analyses; P0.05. This study illustrates a mouse model capable of circumventing in vivo mitochondrial mutations. Moreover, it provides evidence supporting AE as a tool for mtDNA disease research with implications in development of DNA-based therapeutics.

  3. Study on the Parameters of Specific Immune of BALB/c-Mutant Hairless Mice%BALB/c突变无毛小鼠免疫学特性指标的研究

    Institute of Scientific and Technical Information of China (English)

    王冬平; 李善如; 栾蓉晖; 李桂军

    2003-01-01

    The mutant gene of BALB/c-mutant hairless mice was assigned to chromosome 11, Genetic markers which have been tested suggested that the mutation is a new genetic locus that affected the skin and hair structure of the mouse The mutation was named uncoved, with the symbol Uncv . Uncv has been accepted by International Naming Committee of Mice, and the gene information of Uncv has been receipted by the mice's genebank . The skin is the biggest organ of the body , and is also the main physiological barrier between vivo and vitro . The skin is albe to produce and keep the part immunoresponses , inflammation . Many immunoresponses are related to the skin . The dissecting and breeding of the mutant mice show that their immune organs are normal and they can adopt to the general conditions. Objective To further study the mutant gene' s immune function of the BALB/c-mutant hairless mice . Method We tested the parameters of the immune system about two-day-old、two-month-old hairless mice and mutant sparse coat mice . After testing the parameters of CD4 + 、 CD3 + 、 CD8 + 、 CD19 + through flow cytometry and testing the IgG by ELISA. Results we found that CD19+ 、CD4+/CD8+ of male are higher than female about two-week-old mutant mice with sparse coat , but CD8+ of female is higher than the male, CD4+/CD8+ of male F2 sparse coat mice is higher than the female, CD19+ 、IgG of male mutant hairless mice is higher than the female . There were no significant differences among the male and the female about the two-month-old mutant hairless mice and the mutant sparse coat mice, CD4 + of male F2 two-month-old mutant hairless mice is higher than the female . Otherwise , we also found that the celluar immunity and humoral immunity of both two-week-old and two-month-old hairless mice are lower than the mutant sparse coat mice; only the celluar immunity of F2 mutant hairless mice is lower than the mutant sparse coat mice , but the humoral immunity is higher . The experiment suggest

  4. Alternating hemiplegia of childhood-related neural and behavioural phenotypes in Na+,K+-ATPase α3 missense mutant mice.

    Directory of Open Access Journals (Sweden)

    Greer S Kirshenbaum

    Full Text Available Missense mutations in ATP1A3 encoding Na(+,K(+-ATPase α3 have been identified as the primary cause of alternating hemiplegia of childhood (AHC, a motor disorder with onset typically before the age of 6 months. Affected children tend to be of short stature and can also have epilepsy, ataxia and learning disability. The Na(+,K(+-ATPase has a well-known role in maintaining electrochemical gradients across cell membranes, but our understanding of how the mutations cause AHC is limited. Myshkin mutant mice carry an amino acid change (I810N that affects the same position in Na(+,K(+-ATPase α3 as I810S found in AHC. Using molecular modelling, we show that the Myshkin and AHC mutations display similarly severe structural impacts on Na(+,K(+-ATPase α3, including upon the K(+ pore and predicted K(+ binding sites. Behavioural analysis of Myshkin mice revealed phenotypic abnormalities similar to symptoms of AHC, including motor dysfunction and cognitive impairment. 2-DG imaging of Myshkin mice identified compromised thalamocortical functioning that includes a deficit in frontal cortex functioning (hypofrontality, directly mirroring that reported in AHC, along with reduced thalamocortical functional connectivity. Our results thus provide validation for missense mutations in Na(+,K(+-ATPase α3 as a cause of AHC, and highlight Myshkin mice as a starting point for the exploration of disease mechanisms and novel treatments in AHC.

  5. Nootropic nefiracetam inhibits proconvulsant action of peripheral-type benzodiazepines in epileptic mutant EL mice.

    Science.gov (United States)

    Nakamoto, Yurie; Shiotani, Tadashi; Watabe, Shigeo; Nabeshima, Toshitaka; Yoshii, Mitsunobu

    2004-10-01

    Piracetam and structurally related nootropics are known to potentiate the anticonvulsant effects of antiepileptic drugs. It remains to be seen, however, whether these nootropics inhibit proconvulsant actions of many toxic agents including Ro 5-4864, a specific agonist for peripheral-type benzodiazepine receptors (PBR). The present study was designed to address this issue using EL mice, an animal model of epilepsy. In behavioral pharmacological experiments, EL mice were highly susceptible to convulsions induced by Ro 5-4864 (i.p.) in comparison with nonepileptic DDY mice. Nefiracetam administered orally to EL mice inhibited spontaneous seizures. In DDY mice, convulsions induced by Ro 5-4864 were prevented by nefiracetam when administered by i.v. injection. Aniracetam (i.v.) was partially effective, but piracetam and oxiracetam were ineffective as anticonvulsants. Binding assay for brain tissues revealed a higher density of mitochondrial PBR in EL mice compared with DDY mice. Binding of the PBR ligands Ro 5-4864 to either EL or DDY mouse brain was inhibited by micromolar concentrations of these nootropic agents in the sequence of nefiracetam > aniracetam > oxiracetam, piracetam. This rank order is identical to potency as anticonvulsants. These data suggest that nefiracetam may prevent toxic effects of PBR agonists through interacting with PBR.

  6. Effects of metallothionein on zinc metabolism in lethal-milk mutant mice

    Energy Technology Data Exchange (ETDEWEB)

    Grider, A. Jr.

    1986-01-01

    The lethal-milk mice (C57BL/6J-Im) exhibit various pleiotropic effects, including a congenital otolith defect, production of zinc-deficient milk, and clinical signs of a systemic Zn deficiency by one year of age. The clinical signs include alopecia, dermatitis, and skin lesions. The systemic zinc deficiency may be due to increased levels of metallothionein (MT) in the intestine and/or liver of Im mice. The untreated Im mice contain twice as much intestinal MT as do C57BL/6J-(+/sup im//+ /sup Im/) (B6) controls. This was determined by a sulfhydryl assay, by the /sup 109/Cd-saturation/hemolysate method, and by the /sup 65/Zn-binding assay. Various concentrations of Cd or Zn were added to the drinking water three days before assaying for MT. Compared to B6 mice, the Im mice exhibited more MT in their liver by the /sup 65/Zn-MT binding assay (3-fold) and by the /sup 109/Cd-saturation/hemolysate method (18-fold). The effects of the two zinc treatments did not differ significantly between Im and B6 mice. The retention and excretion of /sup 65/Zn (administered intraperitoneally) were determined over a 14-day period, but the results did not different between the Im and B6 mice. The increased concentrations of MT within the Im mice was not significantly different for the intestine and liver. Based on these data and other studies, the Im mice may exhibit alterations in zinc homeostasis due to some deregulation of MT metabolism, including the inner ear of the fetus, the lactating mammary gland, and the intestine and liver of adults by one year of age.

  7. Colorectal tumors from APC*I1307K carriers principally harbor somatic APC mutations outside the A8 tract.

    Directory of Open Access Journals (Sweden)

    Peter Zauber

    Full Text Available PURPOSE: APC*I1307K (c.3920T>A is an inherited variant associated with colorectal tumour risk found almost exclusively in those of Ashkenazi Jewish ancestry. A single nucleotide substitution creates an oligo-adenine tract (A8 that appears to be inherently prone to further mis-pairing and slippage. The reported multiple tumor phenotype of carriers is not easily reconciled with molecular and population genetics data. We postulated that some c.3920T>A carriers with multiple adenomas have other unidentified APC germ line or somatic mutations. METHODS: DNA from 82 colonic tumours and accompanying normal tissue collected from 29 carriers with multiple colorectal tumors was directly sequenced between codons 716 and 1604. We also assessed APC gene loss of heterozygosity. RESULTS: One patient (3.4% was found to have an additional APC germ line mutation. Twenty-five of the tumours showed no significant somatic molecular change, 36 showed one change, 20 showed two, and one tumour showed more than 2 changes. Our data suggest a correlation between advancing histology and fewer beta-catenin binding sites remaining in the mutant proteins. CONCLUSIONS: There were no other common germ line variants identified within the region of the APC gene examined, suggesting that any effect from this region on tumour production is attributable to the c.3920T>A allele. Our findings further suggest the only somatic genetic change clearly attributable to the c.3920T>A mutation is the c.3924_3925insA.

  8. Colorectal Tumors from APC*I1307K Carriers Principally Harbor Somatic APC Mutations outside the A8 Tract

    Science.gov (United States)

    Zauber, Peter; Bishop, Timothy; Taylor, Claire; Sabbath-Solitare, Marlene; Marotta, Stephen; Tomlinson, Ian

    2014-01-01

    Purpose APC*I1307K (c.3920T>A) is an inherited variant associated with colorectal tumour risk found almost exclusively in those of Ashkenazi Jewish ancestry. A single nucleotide substitution creates an oligo-adenine tract (A8) that appears to be inherently prone to further mis-pairing and slippage. The reported multiple tumor phenotype of carriers is not easily reconciled with molecular and population genetics data. We postulated that some c.3920T>A carriers with multiple adenomas have other unidentified APC germ line or somatic mutations. Methods DNA from 82 colonic tumours and accompanying normal tissue collected from 29 carriers with multiple colorectal tumors was directly sequenced between codons 716 and 1604. We also assessed APC gene loss of heterozygosity. Results One patient (3.4%) was found to have an additional APC germ line mutation. Twenty-five of the tumours showed no significant somatic molecular change, 36 showed one change, 20 showed two, and one tumour showed more than 2 changes. Our data suggest a correlation between advancing histology and fewer beta-catenin binding sites remaining in the mutant proteins. Conclusions There were no other common germ line variants identified within the region of the APC gene examined, suggesting that any effect from this region on tumour production is attributable to the c.3920T>A allele. Our findings further suggest the only somatic genetic change clearly attributable to the c.3920T>A mutation is the c.3924_3925insA. PMID:24416237

  9. Reduced activity without hyperphagia contributes to obesity in Tubby mutant mice

    OpenAIRE

    Coyle, Christopher A.; Strand, Sarah C.; Deborah J Good

    2008-01-01

    The Tub gene was originally identified as a spontaneous mutation in C57Bl/6J mice, and associated with adult-onset obesity (Tub MUT mice). Although the original Tub MUT mouse was identified over 15 years ago, there have been few reports on the animal’s food intake, body fat percentage or energy expenditure. In this study, we report food intake, body weight from 5–20 weeks, body fat, body temperature and three different measures of physical activity behavior. Tub MUT mice display reduced food ...

  10. ApcD is required for state transition but not involved in blue-light induced quenching in the cyanobacterium Anabaena sp. PCC7120

    Institute of Scientific and Technical Information of China (English)

    DONG ChunXia; ZHAO JinDong

    2008-01-01

    Pbycobilisomes (PBS) are able to transfer absorbed energy to photosystem Ⅰ and Ⅱ, and the distribution of light energy between two photosystems is regulated by state transitions. In this study we show that energy transfer from PBS to photosystem Ⅰ (PSI) requires ApcD. Cells were unable to perform state transitions in the absence of ApcD. The apcD mutant grows more slowly in light mainly absorbed by PBS, indicating that ApcD-dependent energy transfer to PSI is required for optimal growth under this condition. The apoD mutant showed normal blue-light induced quenching, suggesting that ApcD is not required for this process and state transitions are independent of blue-light induced quenching. Under nitrogen fixing condition, the growth rates of the wild type and the mutant were the same, indicating that energy transfer from PBS to PSI in heterocysta was not required for nitrogen fixation.

  11. Epididymis response partly compensates for spermatozoa oxidative defects in snGPx4 and GPx5 double mutant mice.

    Directory of Open Access Journals (Sweden)

    Anaïs Noblanc

    Full Text Available We report here that spermatozoa of mice lacking both the sperm nucleus glutathione peroxidase 4 (snGPx4 and the epididymal glutathione peroxidase 5 (GPx5 activities display sperm nucleus structural abnormalities including delayed and defective nuclear compaction, nuclear instability and DNA damage. We show that to counteract the GPx activity losses, the epididymis of the double KO animals mounted an antioxydant response resulting in a strong increase in the global H(2O(2-scavenger activity especially in the cauda epididymis. Quantitative RT-PCR data show that together with the up-regulation of epididymal scavengers (of the thioredoxin/peroxiredoxin system as well as glutathione-S-transferases the epididymis of double mutant animals increased the expression of several disulfide isomerases in an attempt to recover normal disulfide-bridging activity. Despite these compensatory mechanisms cauda-stored spermatozoa of double mutant animals show high levels of DNA oxidation, increased fragmentation and greater susceptibility to nuclear decondensation. Nevertheless, the enzymatic epididymal salvage response is sufficient to maintain full fertility of double KO males whatever their age, crossed with young WT female mice.

  12. January 2012 DMM Podcast: histopathology in high-throughput phenotyping of mutant mice

    Science.gov (United States)

    2012-01-01

    SUMMARY Paul Schofield, of Cambridge University, discusses the advantages of including histopathological analysis in large-scale mouse mutant phenotyping pipelines. Narrated by Sarah E. Allan. To listen to this podcast, visit http://www.biologists.com/DMM/podcasts/index.html.

  13. Functionality of cryopreserved juvenile ovaries from mutant mice in different genetic background strains after allotransplantation

    NARCIS (Netherlands)

    Huang, K.Y.; Groot, de S.A.; Woelders, H.; Horst, van der G.T.J.; Themmen, A.P.N.; Colenbrander, B.; Fentener van Vlissingen, J.M.

    2010-01-01

    The rapid expansion of mutant mouse colonies for biomedical research has resulted in lack of space at laboratory animal facilities and increasing risks of losing precious lines. These challenges require cheap and effective methods in addition to freezing embryos and sperm to archive the expanding mu

  14. Laminin alpha2 deficiency and muscular dystrophy; genotype-phenotype correlation in mutant mice

    DEFF Research Database (Denmark)

    Guo, L T; Zhang, X U; Kuang, W

    2003-01-01

    Deficiency of laminin alpha2 is the cause of one of the most severe muscular dystrophies in humans and other species. It is not yet clear how particular mutations in the laminin alpha2 chain gene affect protein expression, and how abnormal levels or structure of the protein affect disease. Animal...... models may be valuable for such genotype-phenotype analysis and for determining mechanism of disease as well as function of laminin. Here, we have analyzed protein expression in three lines of mice with mutations in the laminin alpha2 chain gene and in two lines of transgenic mice overexpressing...... substantially prevented the muscular dystrophy in these mice. However, dy(W)/dy(W) mice, expressing the human laminin alpha2 under the control of the striated muscle-specific portion of the desmin promoter, still developed muscular dystrophy. This failure to rescue is apparently because of insufficient...

  15. The effect of soy isoflavones on the development of intestinal neoplasia in Apc(Min) mouse

    DEFF Research Database (Denmark)

    Sørensen, Ilona Kryspin; Kristiansen, Eva; Mortensen, Alicja

    1998-01-01

    Data from epidemiological studies suggest that isoflavones in soy may have a protective effect on the development of colon cancer in humans. Therefore, we have investigated whether soy isoflavones will inhibit intestinal tumour development in Apc(Min) mice. The mice were fed a Western-type high r...

  16. Acetylcholinesterase activity in the brain of dystonia musculorum (Dst(dt-J)) mutant mice.

    Science.gov (United States)

    Clément, C; Lalonde, R; Strazielle, C

    2012-01-01

    The dystonia musculorum (Dst(dt-J)) mutant mouse suffers from severe motor coordination deficits, characterized, among various symptoms, by a spastic ataxia and dystonic movements, indicating central defects in motor structures in addition to dystrophy of peripheral sensory tracts and partial degeneration of spinocerebellar tracts. Neurochemical alterations, notably in dopaminergic and noradrenergic systems, were previously observed in basal ganglia and cerebellum. A quantitative histochemical cartography of brain acetylcholinesterase activity in Dst(dt-J) mutants, in comparison with controls, revealed increases in the neostriatum, the habenula-interpeduncular pathway, the cholinergic pedunculopontine nucleus and its target structures, the thalamus, major regions of the basal ganglia, such as substantia nigra, ventral tegmental area, globus pallidum, and subthalamic nucleus, as well as in associated extrapyramidal regions, such as red nucleus, brainstem reticular formation, and superior colliculus. These acetylcholinesterase changes may play a role in motor deficits, particularly the dystonic symptomatology observed in the mutation.

  17. Deoxynybomycins inhibit mutant DNA gyrase and rescue mice infected with fluoroquinolone-resistant bacteria.

    Science.gov (United States)

    Parkinson, Elizabeth I; Bair, Joseph S; Nakamura, Bradley A; Lee, Hyang Y; Kuttab, Hani I; Southgate, Emma H; Lezmi, Stéphane; Lau, Gee W; Hergenrother, Paul J

    2015-04-24

    Fluoroquinolones are one of the most commonly prescribed classes of antibiotics, but fluoroquinolone resistance (FQR) is widespread and increasing. Deoxynybomycin (DNM) is a natural-product antibiotic with an unusual mechanism of action, inhibiting the mutant DNA gyrase that confers FQR. Unfortunately, isolation of DNM is difficult and DNM is insoluble in aqueous solutions, making it a poor candidate for development. Here we describe a facile chemical route to produce DNM and its derivatives. These compounds possess excellent activity against FQR methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococci clinical isolates and inhibit mutant DNA gyrase in-vitro. Bacteria that develop resistance to DNM are re-sensitized to fluoroquinolones, suggesting that resistance that emerges to DNM would be treatable. Using a DNM derivative, the first in-vivo efficacy of the nybomycin class is demonstrated in a mouse infection model. Overall, the data presented suggest the promise of DNM derivatives for the treatment of FQR infections.

  18. Consequences of zygote injection and germline transfer of mutant human mitochondrial DNA in mice.

    Science.gov (United States)

    Yu, Hong; Koilkonda, Rajeshwari D; Chou, Tsung-Han; Porciatti, Vittorio; Mehta, Arpit; Hentall, Ian D; Chiodo, Vince A; Boye, Sanford L; Hauswirth, William W; Lewin, Alfred S; Guy, John

    2015-10-20

    Considerable evidence supports mutations in mitochondrial genes as the cause of maternally inherited diseases affecting tissues that rely primarily on oxidative energy metabolism, usually the nervous system, the heart, and skeletal muscles. Mitochondrial diseases are diverse, and animal models currently are limited. Here we introduced a mutant human mitochondrial gene responsible for Leber hereditary optic neuropathy (LHON) into the mouse germ line using fluorescence imaging for tissue-specific enrichment in the target retinal ganglion cells. A mitochondria-targeted adeno-associated virus (MTS-AAV) containing the mutant human NADH ubiquinone oxidoreductase subunit 4 (ND4) gene followed by mitochondrial-encoded mCherry was microinjected into zygotes. Female founders with mCherry fluorescence on ophthalmoscopy were backcrossed with normal males for eight generations. Mutant human ND4 DNA was 20% of mouse ND4 and did not integrate into the host genome. Translated human ND4 protein assembled into host respiratory complexes, decreasing respiratory chain function and increasing oxidative stress. Swelling of the optic nerve head was followed by progressive demise of ganglion cells and their axons, the hallmarks of human LHON. Early visual loss that began at 3 mo and progressed to blindness 8 mo after birth was reversed by intraocular injection of MTS-AAV expressing wild-type human ND4. The technology of introducing human mitochondrial genes into the mouse germ line has never been described, to our knowledge, and has implications not only for creating animal models recapitulating the counterpart human disorder but more importantly for reversing the adverse effects of the mutant gene using gene therapy to deliver the wild-type allele.

  19. Consequences of zygote injection and germline transfer of mutant human mitochondrial DNA in mice

    Science.gov (United States)

    Yu, Hong; Koilkonda, Rajeshwari D.; Chou, Tsung-Han; Porciatti, Vittorio; Mehta, Arpit; Hentall, Ian D.; Chiodo, Vince A.; Boye, Sanford L.; Hauswirth, William W.; Lewin, Alfred S.; Guy, John

    2015-01-01

    Considerable evidence supports mutations in mitochondrial genes as the cause of maternally inherited diseases affecting tissues that rely primarily on oxidative energy metabolism, usually the nervous system, the heart, and skeletal muscles. Mitochondrial diseases are diverse, and animal models currently are limited. Here we introduced a mutant human mitochondrial gene responsible for Leber hereditary optic neuropathy (LHON) into the mouse germ line using fluorescence imaging for tissue-specific enrichment in the target retinal ganglion cells. A mitochondria-targeted adeno-associated virus (MTS-AAV) containing the mutant human NADH ubiquinone oxidoreductase subunit 4 (ND4) gene followed by mitochondrial-encoded mCherry was microinjected into zygotes. Female founders with mCherry fluorescence on ophthalmoscopy were backcrossed with normal males for eight generations. Mutant human ND4 DNA was 20% of mouse ND4 and did not integrate into the host genome. Translated human ND4 protein assembled into host respiratory complexes, decreasing respiratory chain function and increasing oxidative stress. Swelling of the optic nerve head was followed by progressive demise of ganglion cells and their axons, the hallmarks of human LHON. Early visual loss that began at 3 mo and progressed to blindness 8 mo after birth was reversed by intraocular injection of MTS-AAV expressing wild-type human ND4. The technology of introducing human mitochondrial genes into the mouse germ line has never been described, to our knowledge, and has implications not only for creating animal models recapitulating the counterpart human disorder but more importantly for reversing the adverse effects of the mutant gene using gene therapy to deliver the wild-type allele. PMID:26438859

  20. APC and chromosome instability in colorectal cancer

    Directory of Open Access Journals (Sweden)

    C. M. Cabrera

    Full Text Available Colon cancer is a common disease that can be sporadic or familial. An inactivated adenomatous polyposis coli (APC suppressor gene is found in over 80% of colorectal tumors, this being an early alteration in the development of adenomatous polyps. APC function is not only critical for tumor initiation and progression, and chromosome instability (CIN is another characteristic dependent at least partly on APC mutations.

  1. Cox4i2, Ifit2, and Prdm11 Mutant Mice: Effective Selection of Genes Predisposing to an Altered Airway Inflammatory Response from a Large Compendium of Mutant Mouse Lines.

    Science.gov (United States)

    Horsch, Marion; Aguilar-Pimentel, Juan Antonio; Bönisch, Clemens; Côme, Christophe; Kolster-Fog, Cathrine; Jensen, Klaus T; Lund, Anders H; Lee, Icksoo; Grossman, Lawrence I; Sinkler, Christopher; Hüttemann, Maik; Bohn, Erwin; Fuchs, Helmut; Ollert, Markus; Gailus-Durner, Valérie; de Angelis, Martin Hrabĕ; Beckers, Johannes

    2015-01-01

    We established a selection strategy to identify new models for an altered airway inflammatory response from a large compendium of mutant mouse lines that were systemically phenotyped in the German Mouse Clinic (GMC). As selection criteria we included published gene functional data, as well as immunological and transcriptome data from GMC phenotyping screens under standard conditions. Applying these criteria we identified a few from several hundred mutant mouse lines and further characterized the Cox4i2tm1Hutt, Ifit2tm1.1Ebsb, and Prdm11tm1.1ahl lines following ovalbumin (OVA) sensitization and repeated OVA airway challenge. Challenged Prdm11tm1.1ahl mice exhibited changes in B cell counts, CD4+ T cell counts, and in the number of neutrophils in bronchoalveolar lavages, whereas challenged Ifit2tm1.1Ebsb mice displayed alterations in plasma IgE, IgG1, IgG3, and IgM levels compared to the challenged wild type littermates. In contrast, challenged Cox4i2tm1Hutt mutant mice did not show alterations in the humoral or cellular immune response compared to challenged wild type mice. Transcriptome analyses from lungs of the challenged mutant mouse lines showed extensive changes in gene expression in Prdm11tm1.1ahl mice. Functional annotations of regulated genes of all three mutant mouse lines were primarily related to inflammation and airway smooth muscle (ASM) remodeling. We were thus able to define an effective selection strategy to identify new candidate genes for the predisposition to an altered airway inflammatory response under OVA challenge conditions. Similar selection strategies may be used for the analysis of additional genotype-envirotype interactions for other diseases.

  2. [Interaction of the mutant aphakia, fidget and ocular retardation genes in mice].

    Science.gov (United States)

    Koniukhov, B V; Nonchev, S G

    1982-07-01

    The phenogenetic analysis of the effects of aphakia (ak) gene and its interaction with the ocular retardation (or) and fidget (fi) genes suggests that the ak gene acts in the lens cells with the result of arresting lens fibre differentiation. In mice homozygous for ak, the lens failure leads to secondary retina defects, in particular, to formation of retinal folds. In ak/ak or/or mice, the lens and retina morphogenesis stops at the optic cup stage, the eye is strongly reduced in size and more affected, compared to the corresponding single homozygotes. Unlike ak/ak or/or, in the ak/ak fi/fi mice the eyes are more regular in shape than those in the ak/ak +/+ condition. The fi gene inhibition of the retina anlage growth leads to some improvement of the eye development in double ak/ak fi/fi homozygotes, due to the absence of extensive retina folding.

  3. Increased lipolysis and altered lipid homeostasis protect γ-synuclein–null mutant mice from diet-induced obesity

    Science.gov (United States)

    Millership, Steven; Ninkina, Natalia; Guschina, Irina A.; Norton, Jessica; Brambilla, Riccardo; Oort, Pieter J.; Adams, Sean H.; Dennis, Rowena J.; Voshol, Peter J.; Rochford, Justin J.; Buchman, Vladimir L.

    2012-01-01

    Synucleins are a family of homologous proteins principally known for their involvement in neurodegeneration. γ-Synuclein is highly expressed in human white adipose tissue and increased in obesity. Here we show that γ-synuclein is nutritionally regulated in white adipose tissue whereas its loss partially protects mice from high-fat diet (HFD)–induced obesity and ameliorates some of the associated metabolic complications. Compared with HFD-fed WT mice, HFD-fed γ-synuclein–null mutant mice display increased lipolysis, lipid oxidation, and energy expenditure, and reduced adipocyte hypertrophy. Knockdown of γ-synuclein in adipocytes causes redistribution of the key lipolytic enzyme ATGL to lipid droplets and increases lipolysis. γ-Synuclein–deficient adipocytes also contain fewer SNARE complexes of a type involved in lipid droplet fusion. We hypothesize that γ-synuclein may deliver SNAP-23 to the SNARE complexes under lipogenic conditions. Via these independent but complementary roles, γ-synuclein may coordinately modulate lipid storage by influencing lipolysis and lipid droplet formation. Our data reveal γ-synuclein as a regulator of lipid handling in adipocytes, the function of which is particularly important in conditions of nutrient excess. PMID:23213245

  4. Increased lipolysis and altered lipid homeostasis protect γ-synuclein-null mutant mice from diet-induced obesity.

    Science.gov (United States)

    Millership, Steven; Ninkina, Natalia; Guschina, Irina A; Norton, Jessica; Brambilla, Riccardo; Brambilla, Ricardo; Oort, Pieter J; Adams, Sean H; Dennis, Rowena J; Voshol, Peter J; Rochford, Justin J; Buchman, Vladimir L

    2012-12-18

    Synucleins are a family of homologous proteins principally known for their involvement in neurodegeneration. γ-Synuclein is highly expressed in human white adipose tissue and increased in obesity. Here we show that γ-synuclein is nutritionally regulated in white adipose tissue whereas its loss partially protects mice from high-fat diet (HFD)-induced obesity and ameliorates some of the associated metabolic complications. Compared with HFD-fed WT mice, HFD-fed γ-synuclein-null mutant mice display increased lipolysis, lipid oxidation, and energy expenditure, and reduced adipocyte hypertrophy. Knockdown of γ-synuclein in adipocytes causes redistribution of the key lipolytic enzyme ATGL to lipid droplets and increases lipolysis. γ-Synuclein-deficient adipocytes also contain fewer SNARE complexes of a type involved in lipid droplet fusion. We hypothesize that γ-synuclein may deliver SNAP-23 to the SNARE complexes under lipogenic conditions. Via these independent but complementary roles, γ-synuclein may coordinately modulate lipid storage by influencing lipolysis and lipid droplet formation. Our data reveal γ-synuclein as a regulator of lipid handling in adipocytes, the function of which is particularly important in conditions of nutrient excess.

  5. Long-term preservation of cone photoreceptors and visual acuity in rd10 mutant mice exposed to continuous environmental enrichment.

    Science.gov (United States)

    Barone, Ilaria; Novelli, Elena; Strettoi, Enrica

    2014-01-01

    In human patients and animal models of retinitis pigmentosa (RP), a gradual loss of rod photoreceptors and decline in scotopic vision are the primary manifestations of the disease. Secondary death of cones and gradual, regressive remodeling of the inner retina follow and progress at different speeds according to the underlying genetic defect. In any case, the final outcome is near-blindness without a conclusive cure yet. We recently reported that environmental enrichment (EE), an experimental manipulation based on exposure to enhanced motor, sensory, and social stimulation, when started at birth, exerts clear beneficial effects on a mouse model of RP, by slowing vision loss. The purpose of this study was to investigate in the same mouse the long-term effects of chronic exposure to an EE and assess the outcome of this manipulation on cone survival, inner retinal preservation, and visual behavior. Two groups of rd10 mutant mice were maintained in an EE or standard (ST) laboratory conditions up to 1 year of age. Then, retinal preservation was assessed with immunocytochemistry, confocal microscopy examination, cone counts, and electron microscopy of the photoreceptor layer, while visual acuity was tested behaviorally with a Prusky water maze. rd10 mice are a model of autosomal recessive RP with a typical rod-cone, center to the periphery pattern of photoreceptor degeneration. They carry a mutation of the rod-specific phosphodiesterase gene and undergo rod death that peaks at around P24, while cone electroretinogram (ERG) is extinct by P60. We previously showed that early exposure to an EE efficiently delays photoreceptor degeneration in these mutants, extending the time window of cone viability and cone-mediated vision well beyond the phase of maximum rod death. Here we find that a maintained EE can delay the degeneration of cones even in the long term. Confocal and electron microscopy examination of the retinas of the rd10 EE and ST mice at 1 year of age showed major

  6. Lithium improves hippocampal neurogenesis, neuropathology and cognitive functions in APP mutant mice.

    Directory of Open Access Journals (Sweden)

    Anna Fiorentini

    Full Text Available BACKGROUND: Alzheimer's disease (AD is a neurodegenerative disorder characterized by progressive deterioration of cognitive functions, extracellular β-amyloid (Aβ plaques and intracellular neurofibrillary tangles within neocortex and hippocampus. Adult hippocampal neurogenesis plays an important role in learning and memory processes and its abnormal regulation might account for cognitive impairments associated with AD. METHODOLOGY/PRINCIPAL FINDINGS: The double transgenic (Tg CRND8 mice (overexpressing the Swedish and Indiana mutations in the human amyloid precursor protein, aged 2 and 6 months, were used to examine in vivo the effects of 5 weeks lithium treatment. BrdU labelling showed a decreased neurogenesis in the subgranular zone of Tg mice compared to non-Tg mice. The decrease of hippocampal neurogenesis was accompanied by behavioural deficits and worsened with age and pathology severity. The differentiation into neurons and maturation of the proliferating cells were also markedly impaired in the Tg mice. Lithium treatment to 2-month-old Tg mice significantly stimulated the proliferation and neuron fate specification of newborn cells and fully counteracted the transgene-induced impairments of cognitive functions. The drug, by the inhibition of GSK-3β and subsequent activation of Wnt/ß-catenin signalling promoted hippocampal neurogenesis. Finally, the data show that the lithium's ability to stimulate neurogenesis and cognitive functions was lost in the aged Tg mice, thus indicating that the lithium-induced facilitation of neurogenesis and cognitive functions declines as brain Aβ deposition and pathology increases. CONCLUSIONS: Lithium, when given on time, stimulates neurogenesis and counteracts AD-like pathology.

  7. Epileptogenesis and epileptic maturation in phosphorylation site-specific SNAP-25 mutant mice.

    Science.gov (United States)

    Watanabe, Shigeru; Yamamori, Saori; Otsuka, Shintaro; Saito, Masanori; Suzuki, Eiji; Kataoka, Masakazu; Miyaoka, Hitoshi; Takahashi, Masami

    2015-09-01

    Snap25(S187A/S187A) mouse is a knock-in mouse with a single amino acid substitution at a protein kinase C-dependent phosphorylation site of the synaptosomal-associated protein of 25 kDa (SNAP-25), which is a target-soluble NSF attachment protein receptor (t-SNARE) protein essential for neurotransmitter release. Snap25(S187A/S187A) mice exhibit several distinct phenotypes, including reductions in dopamine and serotonin release in the brain, anxiety-like behavior, and cognitive dysfunctions. Homozygous mice show spontaneous epileptic convulsions, and about 15% of the mice die around three weeks after birth. The remaining mice survive for almost two years and exhibit spontaneous recurrent seizures throughout their lifetime. Here, we conducted long-term continuous video electroencephalogram recording of the mice and analyzed the process of epileptogenesis and epileptic maturation in detail. Spikes and slow-wave discharges (SWDs) were observed in the cerebral cortex and thalamus before epileptic convulsions began. SWDs showed several properties similar to those observed in absence seizures including (1) lack of in the hippocampus, (2) movement arrest during SWDs, and (3) inhibition by ethosuximide. Multiple generalized seizures occurred in all homozygous mice around three weeks after birth. However, seizure generation stopped within several days, and a seizure-free latent period began. Following a spike-free quiet period, the number of spikes increased gradually, and epileptic seizures reappeared. Subsequently, spontaneous seizures occurred cyclically throughout the life of the mice, and several progressive changes in seizure frequency, seizure duration, seizure cycle interval, seizure waveform, and the number and waveform of epileptic discharges during slow-wave sleep occurred with different time courses over 10 weeks. Anxiety-related behaviors appeared suddenly within three days after epileptic seizures began and were delayed markedly by oral administration of

  8. Dilated cardiomyopathy in homozygous myosin-binding protein-C mutant mice

    OpenAIRE

    1999-01-01

    To elucidate the role of cardiac myosin-binding protein-C (MyBP-C) in myocardial structure and function, we have produced mice expressing altered forms of this sarcomere protein. The engineered mutations encode truncated forms of MyBP-C in which the cardiac myosin heavy chain-binding and titin-binding domain has been replaced with novel amino acid residues. Analogous heterozygous defects in humans cause hypertrophic cardiomyopathy. Mice that are homozygous for the mutated MyBP-C alleles expre...

  9. Analysis of Two Complementary Single-Gene Deletion Mutant Libraries of Salmonella Typhimurium in Intraperitoneal Infection of BALB/c Mice

    Science.gov (United States)

    Silva-Valenzuela, Cecilia A.; Molina-Quiroz, Roberto C.; Desai, Prerak; Valenzuela, Camila; Porwollik, Steffen; Zhao, Ming; Hoffman, Robert M.; Andrews-Polymenis, Helene; Contreras, Inés; Santiviago, Carlos A.; McClelland, Michael

    2016-01-01

    Two pools of individual single gene deletion (SGD) mutants of S. Typhimurium 14028s encompassing deletions of 3,923 annotated non-essential ORFs and sRNAs were screened by intraperitoneal (IP) injection in BALB/c mice followed by recovery from spleen and liver 2 days post infection. The relative abundance of each mutant was measured by microarray hybridization. The two mutant libraries differed in the orientation of the antibiotic resistance cassettes (either sense-oriented KanR, SGD-K, or antisense-oriented CamR, SGD-C). Consistent systemic colonization defects were observed in both libraries and both organs for hundreds of mutants of genes previously reported to be important after IP injection in this animal model, and for about 100 new candidate genes required for systemic colonization. Four mutants with a range of apparent fitness defects were confirmed using competitive infections with the wild-type parental strain: ΔSTM0286, ΔSTM0551, ΔSTM2363, and ΔSTM3356. Two mutants, ΔSTM0286 and ΔSTM2363, were then complemented in trans with a plasmid encoding an intact copy of the corresponding wild-type gene, and regained the ability to fully colonize BALB/c mice systemically. These results suggest the presence of many more undiscovered Salmonella genes with phenotypes in IP infection of BALB/c mice, and validate the libraries for application to other systems. PMID:26779130

  10. eIF4E/Fmr1 double mutant mice display cognitive impairment in addition to ASD-like behaviors.

    Science.gov (United States)

    Huynh, Thu N; Shah, Manan; Koo, So Yeon; Faraud, Kirsten S; Santini, Emanuela; Klann, Eric

    2015-11-01

    Autism spectrum disorder (ASD) is a group of heritable disorders with complex and unclear etiology. Classic ASD symptoms include social interaction and communication deficits as well as restricted, repetitive behaviors. In addition, ASD is often comorbid with intellectual disability. Fragile X syndrome (FXS) is the leading genetic cause of ASD, and is the most commonly inherited form of intellectual disability. Several mouse models of ASD and FXS exist, however the intellectual disability observed in ASD patients is not well modeled in mice. Using the Fmr1 knockout mouse and the eIF4E transgenic mouse, two previously characterized mouse models of fragile X syndrome and ASD, respectively, we generated the eIF4E/Fmr1 double mutant mouse. Our study shows that the eIF4E/Fmr1 double mutant mice display classic ASD behaviors, as well as cognitive dysfunction. Importantly, the learning impairments displayed by the double mutant mice spanned multiple cognitive tasks. Moreover, the eIF4E/Fmr1 double mutant mice display increased levels of basal protein synthesis. The results of our study suggest that the eIF4E/Fmr1 double mutant mouse may be a reliable model to study cognitive dysfunction in the context of ASD. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Cell cycle- and cell growth-regulated proteolysis of mammalian CDC6 is dependent on APC-CDH1

    DEFF Research Database (Denmark)

    Petersen, B O; Wagener, C; Marinoni, F;

    2000-01-01

    CDC6 is conserved during evolution and is essential and limiting for the initiation of eukaryotic DNA replication. Human CDC6 activity is regulated by periodic transcription and CDK-regulated subcellular localization. Here, we show that, in addition to being absent from nonproliferating cells, CDC6...... is targeted for ubiquitin-mediated proteolysis by the anaphase promoting complex (APC)/cyclosome in G(1). A combination of point mutations in the destruction box and KEN-box motifs in CDC6 stabilizes the protein in G(1) and in quiescent cells. Furthermore, APC, in association with CDH1, ubiquitinates CDC6...... in vitro, and both APC and CDH1 are required and limiting for CDC6 proteolysis in vivo. Although a stable mutant of CDC6 is biologically active, overexpression of this mutant or wild-type CDC6 is not sufficient to induce multiple rounds of DNA replication in the same cell cycle. The APC-CDH1-dependent...

  12. Tumorigenic fragments of APC cause dominant defects in directional cell migration in multiple model systems

    Directory of Open Access Journals (Sweden)

    Scott A. Nelson

    2012-11-01

    Nonsense mutations that result in the expression of truncated, N-terminal, fragments of the adenomatous polyposis coli (APC tumour suppressor protein are found in most sporadic and some hereditary colorectal cancers. These mutations can cause tumorigenesis by eliminating β-catenin-binding sites from APC, which leads to upregulation of β-catenin and thereby results in the induction of oncogenes such as MYC. Here we show that, in three distinct experimental model systems, expression of an N-terminal fragment of APC (N-APC results in loss of directionality, but not speed, of cell motility independently of changes in β-catenin regulation. We developed a system to culture and fluorescently label live pieces of gut tissue to record high-resolution three-dimensional time-lapse movies of cells in situ. This revealed an unexpected complexity of normal gut cell migration, a key process in gut epithelial maintenance, with cells moving with spatial and temporal discontinuity. Quantitative comparison of gut tissue from wild-type mice and APC heterozygotes (APCMin/+; multiple intestinal neoplasia model demonstrated that cells in precancerous epithelia lack directional preference when moving along the crypt-villus axis. This effect was reproduced in diverse experimental systems: in developing chicken embryos, mesoderm cells expressing N-APC failed to migrate normally; in amoeboid Dictyostelium, which lack endogenous APC, expressing an N-APC fragment maintained cell motility, but the cells failed to perform directional chemotaxis; and multicellular Dictyostelium slug aggregates similarly failed to perform phototaxis. We propose that N-terminal fragments of APC represent a gain-of-function mutation that causes cells within tissue to fail to migrate directionally in response to relevant guidance cues. Consistent with this idea, crypts in histologically normal tissues of APCMin/+ intestines are overpopulated with cells, suggesting that a lack of migration might cause cell

  13. An APC/C-Cdh1 Biosensor Reveals the Dynamics of Cdh1 Inactivation at the G1/S Transition.

    Science.gov (United States)

    Ondracka, Andrej; Robbins, Jonathan A; Cross, Frederick R

    2016-01-01

    B-type cyclin-dependent kinase activity must be turned off for mitotic exit and G1 stabilization. B-type cyclin degradation is mediated by the anaphase-promoting complex/cyclosome (APC/C); during and after mitotic exit, APC/C is dependent on Cdh1. Cdh1 is in turn phosphorylated and inactivated by cyclin-CDK at the Start transition of the new cell cycle. We developed a biosensor to assess the cell cycle dynamics of APC/C-Cdh1. Nuclear exit of the G1 transcriptional repressor Whi5 is a known marker of Start; APC/C-Cdh1 is inactivated 12 min after Whi5 nuclear exit with little measurable cell-to-cell timing variability. Multiple phosphorylation sites on Cdh1 act in a redundant manner to repress its activity. Reducing the number of phosphorylation sites on Cdh1 can to some extent be tolerated for cell viability, but it increases variability in timing of APC/C-Cdh1 inactivation. Mutants with minimal subsets of phosphorylation sites required for viability exhibit striking stochasticity in multiple responses including budding, nuclear division, and APC/C-Cdh1 activity itself. Multiple cyclin-CDK complexes, as well as the stoichiometric inhibitor Acm1, contribute to APC/C-Cdh1 inactivation; this redundant control is likely to promote rapid and reliable APC/C-Cdh1 inactivation immediately following the Start transition.

  14. An APC/C-Cdh1 Biosensor Reveals the Dynamics of Cdh1 Inactivation at the G1/S Transition

    Science.gov (United States)

    Ondracka, Andrej; Robbins, Jonathan A.; Cross, Frederick R.

    2016-01-01

    B-type cyclin-dependent kinase activity must be turned off for mitotic exit and G1 stabilization. B-type cyclin degradation is mediated by the anaphase-promoting complex/cyclosome (APC/C); during and after mitotic exit, APC/C is dependent on Cdh1. Cdh1 is in turn phosphorylated and inactivated by cyclin-CDK at the Start transition of the new cell cycle. We developed a biosensor to assess the cell cycle dynamics of APC/C-Cdh1. Nuclear exit of the G1 transcriptional repressor Whi5 is a known marker of Start; APC/C-Cdh1 is inactivated 12 min after Whi5 nuclear exit with little measurable cell-to-cell timing variability. Multiple phosphorylation sites on Cdh1 act in a redundant manner to repress its activity. Reducing the number of phosphorylation sites on Cdh1 can to some extent be tolerated for cell viability, but it increases variability in timing of APC/C-Cdh1 inactivation. Mutants with minimal subsets of phosphorylation sites required for viability exhibit striking stochasticity in multiple responses including budding, nuclear division, and APC/C-Cdh1 activity itself. Multiple cyclin-CDK complexes, as well as the stoichiometric inhibitor Acm1, contribute to APC/C-Cdh1 inactivation; this redundant control is likely to promote rapid and reliable APC/C-Cdh1 inactivation immediately following the Start transition. PMID:27410035

  15. A novel gain of function mutant in C-kit gene and its tumorigenesis in nude mice

    Institute of Scientific and Technical Information of China (English)

    Chen-Guang Bai; Xiao-Hong Liu; Qiang Xie; Fei Feng; Da-Lie Ma

    2005-01-01

    AIM: To transfect mutant C-kit cDNA at codon 579 into human embryonic kidney cell line to observe its role in the pathogenesis of gastrointestinal stromal tumor (GIST).METHODS: Eukaryotic expression vectors of pcDNA3-Kit-NW and pcDNA3-Kit-W were constructed. Then pcDNA3-Kit-NW and pcDNA3-Kit-W plasmids were transfected into human embryonic kidney cell line by Lipofectamine. The resistant done was screened by G418filtration and identified by sequencing, Western blotting,and immunocytochemical staining. Human embryonic kidney cells were divided into three groups including pcDNA3-Kit-NW, pcDNA3-Kit-W, and vector control groups. Absorbency value with a wavelength of 574 nm was detected by MTT analysis. Mice were injected with three groups of cells. Volume, mass, and histological examinations of the tumors in different groups were measured and compared.RESULTS: The C-kit gene and mutant C-kit gene were successfully cloned into the eukaryotic expression vector pcDNA3. pcDNA3-Kit-NW and pcDNA3-Kit-W were successfully transfected into human embryonic kidney cell line and showed stable expression in this cell line.Cell proliferating activity had significant differences between pcDNA3-Kit-NW and pcDNA3, pcDNA3-KitNW and pcDNA3-Kit-W (P<0.05), respectively. Tumors were only observed in nude mice implanted with cells transfected with pcDNA3-Kit-NW.CONCLUSION: Mutation of C-kit gene increases the proliferation activity of human cells and plays an important role in the malignant transformation of GIST.

  16. Sex-dependent novelty response in neurexin-1α mutant mice.

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    Marijke C Laarakker

    Full Text Available Neurexin-1 alpha (NRXN1α belongs to the family of cell adhesion molecules (CAMs, which are involved in the formation of neuronal networks and synapses. NRXN1α gene mutations have been identified in neuropsychiatric diseases including Schizophrenia (SCZ and Autism Spectrum Disorder (ASD. In order to get a better understanding of the pleiotropic behavioral manifestations caused by NRXN1α gene mutations, we performed a behavioral study of Nrxn1α heterozygous knock-out (+/- mice and observed increased responsiveness to novelty and accelerated habituation to novel environments compared to wild type (+/+ litter-mates. However, this effect was mainly observed in male mice, strongly suggesting that gender-specific mechanisms play an important role in Nrxn1α-induced phenotypes.

  17. Genetic background modifies nuclear mutant huntingtin accumulation and HD CAG repeat instability in Huntington's disease knock-in mice.

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    Lloret, Alejandro; Dragileva, Ella; Teed, Allison; Espinola, Janice; Fossale, Elisa; Gillis, Tammy; Lopez, Edith; Myers, Richard H; MacDonald, Marcy E; Wheeler, Vanessa C

    2006-06-15

    Genetically precise models of Huntington's disease (HD), Hdh CAG knock-in mice, are powerful systems in which phenotypes associated with expanded HD CAG repeats are studied. To dissect the genetic pathways that underlie such phenotypes, we have generated Hdh(Q111) knock-in mouse lines that are congenic for C57BL/6, FVB/N and 129Sv inbred genetic backgrounds and investigated four Hdh(Q111) phenotypes in these three genetic backgrounds: the intergenerational instability of the HD CAG repeat and the striatal-specific somatic HD CAG repeat expansion, nuclear mutant huntingtin accumulation and intranuclear inclusion formation. Our results reveal increased intergenerational and somatic instability of the HD CAG repeat in C57BL/6 and FVB/N backgrounds compared with the 129Sv background. The accumulation of nuclear mutant huntingtin and the formation of intranuclear inclusions were fastest in the C57BL/6 background, slowest in the 129Sv background and intermediate in the FVB/N background. Inbred strain-specific differences were independent of constitutive HD CAG repeat size and did not correlate with Hdh mRNA levels. These data provide evidence for genetic modifiers of both intergenerational HD CAG repeat instability and striatal-specific phenotypes. Different relative contributions of C57BL/6 and 129Sv genetic backgrounds to the onset of nuclear mutant huntingtin and somatic HD CAG repeat expansion predict that the initiation of each of these two phenotypes is modified by different genes. Our findings set the stage for defining disease-related genetic pathways that will ultimately provide insight into disease mechanism.

  18. Impact of retinoic acid exposure on midfacial shape variation and manifestation of holoprosencephaly in Twsg1 mutant mice

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    Charles J. Billington

    2015-02-01

    Full Text Available Holoprosencephaly (HPE is a developmental anomaly characterized by inadequate or absent midline division of the embryonic forebrain and midline facial defects. It is believed that interactions between genes and the environment play a role in the widely variable penetrance and expressivity of HPE, although direct investigation of such effects has been limited. The goal of this study was to examine whether mice carrying a mutation in a gene encoding the bone morphogenetic protein (BMP antagonist twisted gastrulation (Twsg1, which is associated with a low penetrance of HPE, are sensitized to retinoic acid (RA teratogenesis. Pregnant Twsg1+/− dams were treated by gavage with a low dose of all-trans RA (3.75 mg/kg of body weight. Embryos were analyzed between embryonic day (E9.5 and E11.5 by microscopy and geometric morphometric analysis by micro-computed tomography. P19 embryonal carcinoma cells were used to examine potential mechanisms mediating the combined effects of increased BMP and retinoid signaling. Although only 7% of wild-type embryos exposed to RA showed overt HPE or neural tube defects (NTDs, 100% of Twsg1−/− mutants exposed to RA manifested severe HPE compared to 17% without RA. Remarkably, up to 30% of Twsg1+/− mutants also showed HPE (23% or NTDs (7%. The majority of shape variation among Twsg1+/− mutants was associated with narrowing of the midface. In P19 cells, RA induced the expression of Bmp2, acted in concert with BMP2 to increase p53 expression, caspase activation and oxidative stress. This study provides direct evidence for modifying effects of the environment in a genetic mouse model carrying a predisposing mutation for HPE in the Twsg1 gene. Further study of the mechanisms underlying these gene-environment interactions in vivo will contribute to better understanding of the pathogenesis of birth defects and present an opportunity to explore potential preventive interventions.

  19. Effects of Pharmacologic and Genetic Inhibition of Alk on Cognitive Impairments in NF1 Mutant Mice

    Science.gov (United States)

    2015-06-01

    in the general population. Specific learning disabilities in reading, spelling and math occur in 20% of children without overt central nervous...Distribution Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT We studied the expression of Alk and the effects of Alk mutations on learning and memory...even rescue learning impairments in mice. We describe the breeding data for the genetic study and the behavioral data so far for the genetic study

  20. Intracerebral Distribution of the Oncometabolite D-2-Hydroxyglutarate in Mice Bearing Mutant Isocitrate Dehydrogenase Brain Tumors: Implications for Tumorigenesis

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    Amanda Pickard

    2016-10-01

    Full Text Available The prevalence of mutant IDH1 brain tumors has generated significant efforts to understand the role of the mutated enzyme product D-2-hydroxyglutarate (D2HG, an oncometabolite, in tumorigenesis, as well as means to eliminate it. Glymphatic clearance was proposed as a pathway that could be manipulated to accelerate D2HG clearance and dictated the study design that consisted of two cohorts of mice bearing U87/mutant IDH1 intracerebral tumors who underwent two microdialysis – providing D2HG interstitial fluid concentrations - sampling periods of awake and asleep (activate glymphatic clearance in a crossover manner. Glymphatic clearance was found not to have a significant effect on D2HG brain tumor interstitial fluid concentrations that were 126.9 ± 74.8 µM awake and 117.6 ± 98.6 µM asleep. These concentrations, although low relative to total brain tumor concentrations of 6.8 ± 3.6 mM, were considered sufficient to be transported by interstitial fluid and taken up into normal cells to cause deleterious effects. A model of D2HG CNS distribution supported this contention and was further supported by in vitro studies that showed D2HG could interfere with immune cell function. The study provides insight into the compartmental distribution of D2HG in the brain wherein the interstitial fluid serves as a dynamic pathway for D2HG to enter normal cells and contribute to tumorigenesis.

  1. CaMKII modulates sodium current in neurons from epileptic Scn2a mutant mice.

    Science.gov (United States)

    Thompson, Christopher H; Hawkins, Nicole A; Kearney, Jennifer A; George, Alfred L

    2017-02-14

    Monogenic epilepsies with wide-ranging clinical severity have been associated with mutations in voltage-gated sodium channel genes. In the Scn2a(Q54) mouse model of epilepsy, a focal epilepsy phenotype is caused by transgenic expression of an engineered NaV1.2 mutation displaying enhanced persistent sodium current. Seizure frequency and other phenotypic features in Scn2a(Q54) mice depend on genetic background. We investigated the neurophysiological and molecular correlates of strain-dependent epilepsy severity in this model. Scn2a(Q54) mice on the C57BL/6J background (B6.Q54) exhibit a mild disorder, whereas animals intercrossed with SJL/J mice (F1.Q54) have a severe phenotype. Whole-cell recording revealed that hippocampal pyramidal neurons from B6.Q54 and F1.Q54 animals exhibit spontaneous action potentials, but F1.Q54 neurons exhibited higher firing frequency and greater evoked activity compared with B6.Q54 neurons. These findings correlated with larger persistent sodium current and depolarized inactivation in neurons from F1.Q54 animals. Because calcium/calmodulin protein kinase II (CaMKII) is known to modify persistent current and channel inactivation in the heart, we investigated CaMKII as a plausible modulator of neuronal sodium channels. CaMKII activity in hippocampal protein lysates exhibited a strain-dependence in Scn2a(Q54) mice with higher activity in F1.Q54 animals. Heterologously expressed NaV1.2 channels exposed to activated CaMKII had enhanced persistent current and depolarized channel inactivation resembling the properties of F1.Q54 neuronal sodium channels. By contrast, inhibition of CaMKII attenuated persistent current, evoked a hyperpolarized channel inactivation, and suppressed neuronal excitability. We conclude that CaMKII-mediated modulation of neuronal sodium current impacts neuronal excitability in Scn2a(Q54) mice and may represent a therapeutic target for the treatment of epilepsy.

  2. Different Phenotypic Consequences of Simultaneous Versus Stepwise Apc Loss

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    Fischer, Jared M.; Miller, Ashleigh J; Shibata, Darryl; Liskay, R. Michael

    2011-01-01

    APC is considered a gatekeeper for colorectal cancer (CRC). Cells with heterozygous APC mutations have altered expression profiles suggesting that the first APC hit may help set the stage for subsequent transformation. Therefore, we measured transformation efficiency following what we have designated as “simultaneous” versus “stepwise” Apc loss. We combined a conditional Apc allele (ApcCKO ) with a Cre reporter gene and an out-of-frame Cre allele (Pms2cre ) that stochastically becomes functio...

  3. APC mutations as a potential biomarker for sensitivity to tankyrase inhibitors in colorectal cancer.

    Science.gov (United States)

    Tanaka, Noritaka; Mashima, Tetsuo; Mizutani, Anna; Sato, Ayana; Aoyama, Aki; Gong, Bo; Yoshida, Haruka; Muramatsu, Yukiko; Nakata, Kento; Matsuura, Masaaki; Katayama, Ryohei; Nagayama, Satoshi; Fujita, Naoya; Sugimoto, Yoshikazu; Seimiya, Hiroyuki

    2017-02-08

    In most colorectal cancers (CRCs), Wnt/β-catenin signaling is activated by loss-of-function mutations in the adenomatous polyposis coli (APC) gene and plays a critical role in tumorigenesis. Tankyrases poly(ADP-ribosyl)ate and destabilize Axins, a negative regulator of β-catenin, and upregulate β-catenin signaling. Tankyrase inhibitors downregulate β-catenin and are expected to be promising therapeutics for CRC. However, CRC cells are not always sensitive to tankyrase inhibitors, and predictive biomarkers for the drug sensitivity remain elusive. Here we demonstrate that the short-form APC mutations predict the sensitivity of CRC cells to tankyrase inhibitors. By using well-established CRC cell lines, we found that tankyrase inhibitors downregulated β-catenin in the drug-sensitive but not resistant CRC cells. The drug-sensitive cells showed higher Tcf/LEF transcriptional activity than the resistant cells and possessed 'short' truncated APCs lacking all seven β-catenin-binding 20-amino-acid repeats (20-AARs). By contrast, the drug-resistant cells possessed 'long' APC retaining two or more 20-AARs. Knockdown of the long APCs with two 20-AARs increased β-catenin, Tcf/LEF transcriptional activity and its target gene AXIN2 expression. Under these conditions, tankyrase inhibitors were able to downregulate β-catenin in the resistant cells. These results indicate that the long APCs are hypomorphic mutants whereas they exert a dominant-negative effect on Axin-dependent β-catenin degradation caused by tankyrase inhibitors. Finally, we established 16 patient-derived CRC cells and confirmed that the tankyrase inhibitor-responsive cells harbor the short-form APC mutations. These observations exemplify the predictive importance of APC mutations, the most common genetic alteration in CRCs, for molecular targeted therapeutics.

  4. Na(v)1.8 channelopathy in mutant mice deficient for myelin protein zero is detrimental to motor axons.

    Science.gov (United States)

    Moldovan, Mihai; Alvarez, Susana; Pinchenko, Volodymyr; Klein, Dennis; Nielsen, Finn Cilius; Wood, John N; Martini, Rudolf; Krarup, Christian

    2011-02-01

    Myelin protein zero mutations were found to produce Charcot-Marie-Tooth disease phenotypes with various degrees of myelin impairment and axonal loss, ranging from the mild 'demyelinating' adult form to severe and early onset forms. Protein zero deficient homozygous mice ( ) show a severe and progressive dysmyelinating neuropathy from birth with compromised myelin compaction, hypomyelination and distal axonal degeneration. A previous study using immunofluorescence showed that motor nerves deficient of myelin protein zero upregulate the Na(V)1.8 voltage gated sodium channel isoform, which is normally present only in restricted populations of sensory axons. The aim of this study was to investigate the function of motor axons in protein zero-deficient mice with particular emphasis on ectopic Na(V)1.8 voltage gated sodium channel. We combined 'threshold tracking' excitability studies with conventional nerve conduction studies, behavioural studies using rotor-rod measurements, and histological measures to assess membrane dysfunction and its progression in protein zero deficient homozygous mutants as compared with age-matched wild-type controls. The involvement of Na(V)1.8 was investigated by pharmacologic block using the subtype-selective Na(V)1.8 blocker A-803467 and chronically in Na(V)1.8 knock-outs. We found that in the context of dysmyelination, abnormal potassium ion currents and membrane depolarization, the ectopic Na(V)1.8 channels further impair the motor axon excitability in protein zero deficient homozygous mutants to an extent that precipitates conduction failure in severely affected axons. Our data suggest that a Na(V)1.8 channelopathy contributed to the poor motor function of protein zero deficient homozygous mutants, and that the conduction failure was associated with partially reversible reduction of the electrically evoked muscle response and of the clinical function as indicated by the partial recovery of function at rotor-rod measurements. As a

  5. The targeted overexpression of a Claudin mutant in the epidermis of transgenic mice elicits striking epidermal and hair follicle abnormalities.

    Science.gov (United States)

    Troy, Tammy-Claire; Turksen, Kursad

    2007-06-01

    Skin is one of the largest organs of the body, and is formed during development through a highly orchestrated process involving mesenchymal-epithelial interactions, cell commitment, and terminal differentiation. It protects against microorganism invasion and UV irradiation, inhibits water loss, regulates body temperature, and is an important part of the immune system. Using transgenic mouse technology, we have demonstrated that Claudin (Cldn)-containing tight junctions (TJs) are intricately involved in cell signaling during epidermal differentiation and that an epidermal suprabasal overexpression of Cldn6 results in a perturbed epidermal terminal differentiation program with distinct phenotypic abnormalities. To delineate the role of the Cldn cytoplasmic tail domain in epidermal differentiation, we engineered transgenic mice targeting the overexpression of a Cldn6 cytoplasmic tail-truncation mutant in the epidermis. Transgenic mice were characterized by a lethal barrier dysfunction in addition to the existence of hyperproliferative squamous invaginations/cysts replacing hair follicles. Immunohistochemical analysis revealed an epidermal cytoplasmic accumulation of Cldn6, Cldn11, Cldn12, and Cldn18, downregulation of Cldn1 and aberrant expression of various classical markers of epidermal differentiation; namely the basal keratins as well as K1, involucrin, loricrin, and filaggrin. Collectively these studies suggest an important role for Cldns in epidermal/hair follicle differentiation programs likely involving cross talk to signaling pathways (e.g., Notch) directing cell fate selection and differentiation.

  6. Aggressive acute myeloid leukemia in PU.1/p53 double-mutant mice.

    Science.gov (United States)

    Basova, P; Pospisil, V; Savvulidi, F; Burda, P; Vargova, K; Stanek, L; Dluhosova, M; Kuzmova, E; Jonasova, A; Steidl, U; Laslo, P; Stopka, T

    2014-09-25

    PU.1 downregulation within hematopoietic stem and progenitor cells (HSPCs) is the primary mechanism for the development of acute myeloid leukemia (AML) in mice with homozygous deletion of the upstream regulatory element (URE) of PU.1 gene. p53 is a well-known tumor suppressor that is often mutated in human hematologic malignancies including AML and adds to their aggressiveness; however, its genetic deletion does not cause AML in mouse. Deletion of p53 in the PU.1(ure/ure) mice (PU.1(ure/ure)p53(-/-)) results in more aggressive AML with shortened overall survival. PU.1(ure/ure)p53(-/-) progenitors express significantly lower PU.1 levels. In addition to URE deletion we searched for other mechanisms that in the absence of p53 contribute to decreased PU.1 levels in PU.1(ure/ure)p53(-/-) mice. We found involvement of Myb and miR-155 in downregulation of PU.1 in aggressive murine AML. Upon inhibition of either Myb or miR-155 in vitro the AML progenitors restore PU.1 levels and lose leukemic cell growth similarly to PU.1 rescue. The MYB/miR-155/PU.1 axis is a target of p53 and is activated early after p53 loss as indicated by transient p53 knockdown. Furthermore, deregulation of both MYB and miR-155 coupled with PU.1 downregulation was observed in human AML, suggesting that MYB/miR-155/PU.1 mechanism may be involved in the pathogenesis of AML and its aggressiveness characterized by p53 mutation.

  7. Endocannabinoid system and drug addiction: new insights from mutant mice approaches.

    Science.gov (United States)

    Maldonado, Rafael; Robledo, Patricia; Berrendero, Fernando

    2013-08-01

    The involvement of the endocannabinoid system in drug addiction was initially studied by the use of compounds with different affinities for each cannabinoid receptor or for the proteins involved in endocannabinoids inactivation. The generation of genetically modified mice with selective mutations in these endocannabinoid system components has now provided important advances in establishing their specific contribution to drug addiction. These genetic tools have identified the particular interest of CB1 cannabinoid receptor and endogenous anandamide as potential targets for drug addiction treatment. Novel genetic tools will allow determining if the modulation of CB2 cannabinoid receptor activity and 2-arachidonoylglycerol tone can also have an important therapeutic relevance for drug addiction.

  8. Lethality in PARP-1/Ku80 double mutant mice reveals physiologicalsynergy during early embryogenesis

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    Henrie, Melinda S.; Kurimasa, Akihiro; Burma, Sandeep; Menissier-de Murcia, Josiane; de Murcia, Gilbert; Li, Gloria C.; Chen,David J.

    2002-09-24

    Ku is an abundant heterodimeric nuclear protein, consisting of 70-kDa and 86-kDa tightly associated subunits that comprise the DNA binding component of DNA-dependent protein kinase. Poly(ADP)ribose polymerase-1 (PARP-1) is a 113-kDa protein that catalyzes the synthesis of poly(ADP-ribose) on target proteins. Both Ku and PARP-1 recognize and bind to DNA ends. Ku functions in the non-homologous end joining (NHEJ) repair pathway whereas PARP-1 functions in the single strand break repair and base excision repair (BER) pathways. Recent studies have revealed that PARP-1 and Ku80 interact in vitro. To determine whether the association of PARP-1 and Ku80 has any physiological significance or synergistic function in vivo, mice lacking both PARP-1 and Ku80 were generated. The resulting offspring died during embryonic development displaying abnormalities around the gastrulation stage. In addition, PARP-1-/-Ku80-/- cultured blastocysts had an increased level of apoptosis. These data suggest that the functions of both Ku80 and PARP-1 are essential for normal embryogenesis and that a loss of genomic integrity leading to cell death through apoptosis is likely the cause of the embryonic lethality observed in these mice.

  9. High amplitude phase resetting in rev-erbalpha/per1 double mutant mice.

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    Corinne Jud

    Full Text Available Over time, organisms developed various strategies to adapt to their environment. Circadian clocks are thought to have evolved to adjust to the predictable rhythms of the light-dark cycle caused by the rotation of the Earth around its own axis. The rhythms these clocks generate persist even in the absence of environmental cues with a period of about 24 hours. To tick in time, they continuously synchronize themselves to the prevailing photoperiod by appropriate phase shifts. In this study, we disrupted two molecular components of the mammalian circadian oscillator, Rev-Erbalpha and Period1 (Per1. We found that mice lacking these genes displayed robust circadian rhythms with significantly shorter periods under constant darkness conditions. Strikingly, they showed high amplitude resetting in response to a brief light pulse at the end of their subjective night phase, which is rare in mammals. Surprisingly, Cry1, a clock component not inducible by light in mammals, became slightly inducible in these mice. Taken together, Rev-Erbalpha and Per1 may be part of a mechanism preventing drastic phase shifts in mammals.

  10. Regulation of nuclear envelope dynamics via APC/C is necessary for the progression of semi-open mitosis in Schizosaccharomyces japonicus.

    Science.gov (United States)

    Aoki, Keita; Shiwa, Yuh; Takada, Hiraku; Yoshikawa, Hirofumi; Niki, Hironori

    2013-09-01

    Three types of mitosis, which are open, closed or semi-open mitosis, function in eukaryotic cells, respectively. The open mitosis involves breakage of the nuclear envelope before nuclear division, whereas the closed mitosis proceeds with an intact nuclear envelope. To understand the mechanism and significance of three types of mitotic division in eukaryotes, we investigated the process of semi-open mitosis, in which the nuclear envelope is only partially broken, in the fission yeast Schizosaccharomyces japonicus. In anaphase-promoting complex/cyclosome (APC/C) mutants of Sz. japonicus, the nuclear envelope remained relatively intact during anaphase, resulting in impaired semi-open mitosis. As a suppressor of apc2 mutant, a mutation of Oar2, which was a 3-oxoacyl-[acyl carrier protein] reductase, was obtained. The level of the Oar2, which had two destruction-box motifs recognized by APC/C, was increased in APC/C mutants. Furthermore, the defective semi-open mitosis observed in an apc2 mutant was restored by mutated oar2+. Based on these findings, we propose that APC/C regulates the dynamics of the nuclear envelope through degradation of Oar2 dependent on APC/C during the metaphase-to-anaphase transition of semi-open mitosis in Sz. japonicus.

  11. New Functions of APC/C Ubiquitin Ligase in the Nervous System and Its Role in Alzheimer’s Disease

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    Tanja Fuchsberger

    2017-05-01

    Full Text Available The E3 ubiquitin ligase Anaphase Promoting Complex/Cyclosome (APC/C regulates important processes in cells, such as the cell cycle, by targeting a set of substrates for degradation. In the last decade, APC/C has been related to several major functions in the nervous system, including axon guidance, synaptic plasticity, neurogenesis, and neuronal survival. Interestingly, some of the identified APC/C substrates have been related to neurodegenerative diseases. There is an accumulation of some degradation targets of APC/C in Alzheimer’s disease (AD brains, which suggests a dysregulation of the protein complex in the disorder. Moreover, recently evidence has been provided for an inactivation of APC/C in AD. It has been shown that oligomers of the AD-related peptide, Aβ, induce degradation of the APC/C activator subunit cdh1, in vitro in neurons in culture and in vivo in the mouse hippocampus. Furthermore, in the AD mouse model APP/PS1, lower cdh1 levels were observed in pyramidal neurons in CA1 when compared to age-matched wildtype mice. In this review, we provide a complete list of APC/C substrates that are involved in the nervous system and we discuss their functions. We also summarize recent studies that show neurobiological effects in cdh1 knockout mouse models. Finally, we discuss the role of APC/C in the pathophysiology of AD.

  12. Characterization of age-dependent and progressive cortical neuronal degeneration in presenilin conditional mutant mice.

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    Mary Wines-Samuelson

    Full Text Available Presenilins are the major causative genes of familial Alzheimer's disease (AD. Our previous study has demonstrated essential roles of presenilins in memory and neuronal survival. Here, we explore further how loss of presenilins results in age-related, progressive neurodegeneration in the adult cerebral cortex, where the pathogenesis of AD occurs. To circumvent the requirement of presenilins for embryonic development, we used presenilin conditional double knockout (Psen cDKO mice, in which presenilin inactivation is restricted temporally and spatially to excitatory neurons of the postnatal forebrain beginning at 4 weeks of age. Increases in the number of degenerating (Fluoro-Jade B+, 7.6-fold and apoptotic (TUNEL+, 7.4-fold neurons, which represent approximately 0.1% of all cortical neurons, were first detected at 2 months of age when there is still no significant loss of cortical neurons and volume in Psen cDKO mice. By 4 months of age, significant loss of cortical neurons (approximately 9% and gliosis was found in Psen cDKO mice. The apoptotic cell death is associated with caspase activation, as shown by increased numbers of cells immunoreactive for active caspases 9 and 3 in the Psen cDKO cortex. The vulnerability of cortical neurons to loss of presenilins is region-specific with cortical neurons in the lateral cortex most susceptible. Compared to the neocortex, the increase in apoptotic cell death and the extent of neurodegeneration are less dramatic in the Psen cDKO hippocampus, possibly in part due to increased neurogenesis in the aging dentate gyrus. Neurodegeneration is also accompanied with mitochondrial defects, as indicated by reduced mitochondrial density and altered mitochondrial size distribution in aging Psen cortical neurons. Together, our findings show that loss of presenilins in cortical neurons causes apoptotic cell death occurring in a very small percentage of neurons, which accumulates over time and leads to substantial loss

  13. Identification of a glycogen synthase kinase-3β inhibitor that attenuates hyperactivity in CLOCK mutant mice.

    Science.gov (United States)

    Kozikowski, Alan P; Gunosewoyo, Hendra; Guo, Songpo; Gaisina, Irina N; Walter, Richard L; Ketcherside, Ariel; McClung, Colleen A; Mesecar, Andrew D; Caldarone, Barbara

    2011-09-05

    Bipolar disorder is characterized by a cycle of mania and depression, which affects approximately 5 million people in the United States. Current treatment regimes include the so-called "mood-stabilizing drugs", such as lithium and valproate that are relatively dated drugs with various known side effects. Glycogen synthase kinase-3β (GSK-3β) plays a central role in regulating circadian rhythms, and lithium is known to be a direct inhibitor of GSK-3β. We designed a series of second generation benzofuran-3-yl-(indol-3-yl)maleimides containing a piperidine ring that possess IC₅₀ values in the range of 4 to 680 nM against human GSK-3β. One of these compounds exhibits reasonable kinase selectivity and promising preliminary absorption, distribution, metabolism, and excretion (ADME) data. The administration of this compound at doses of 10 to 25 mg kg⁻¹ resulted in the attenuation of hyperactivity in amphetamine/chlordiazepoxide-induced manic-like mice together with enhancement of prepulse inhibition, similar to the effects found for valproate (400 mg kg⁻¹) and the antipsychotic haloperidol (1 mg kg⁻¹). We also tested this compound in mice carrying a mutation in the central transcriptional activator of molecular rhythms, the CLOCK gene, and found that the same compound attenuates locomotor hyperactivity in response to novelty. This study further demonstrates the use of inhibitors of GSK-3β in the treatment of manic episodes of bipolar/mood disorders, thus further validating GSK-3β as a relevant therapeutic target in the identification of new therapies for bipolar patients. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Identification of a Glycogen Synthase Kinase-3[beta] Inhibitor that Attenuates Hyperactivity in CLOCK Mutant Mice

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    Kozikowski, Alan P.; Gunosewoyo, Hendra; Guo, Songpo; Gaisina, Irina N.; Walter, Richard L.; Ketcherside, Ariel; McClung, Colleen A.; Mesecar, Andrew D.; Caldarone, Barbara (Psychogenics); (Purdue); (UIC); (UTSMC)

    2012-05-02

    Bipolar disorder is characterized by a cycle of mania and depression, which affects approximately 5 million people in the United States. Current treatment regimes include the so-called 'mood-stabilizing drugs', such as lithium and valproate that are relatively dated drugs with various known side effects. Glycogen synthase kinase-3{beta} (GSK-3{beta}) plays a central role in regulating circadian rhythms, and lithium is known to be a direct inhibitor of GSK-3{beta}. We designed a series of second generation benzofuran-3-yl-(indol-3-yl)maleimides containing a piperidine ring that possess IC{sub 50} values in the range of 4 to 680 nM against human GSK-3{beta}. One of these compounds exhibits reasonable kinase selectivity and promising preliminary absorption, distribution, metabolism, and excretion (ADME) data. The administration of this compound at doses of 10 to 25 mg kg{sup -1} resulted in the attenuation of hyperactivity in amphetamine/chlordiazepoxide-induced manic-like mice together with enhancement of prepulse inhibition, similar to the effects found for valproate (400 mg kg{sup -1}) and the antipsychotic haloperidol (1 mg kg{sup -1}). We also tested this compound in mice carrying a mutation in the central transcriptional activator of molecular rhythms, the CLOCK gene, and found that the same compound attenuates locomotor hyperactivity in response to novelty. This study further demonstrates the use of inhibitors of GSK-3{beta} in the treatment of manic episodes of bipolar/mood disorders, thus further validating GSK-3{beta} as a relevant therapeutic target in the identification of new therapies for bipolar patients.

  15. Direct reversal of DNA damage by mutant methyltransferase protein protects mice against dose-intensified chemotherapy and leads to in vivo selection of hematopoietic stem cells.

    Science.gov (United States)

    Ragg, S; Xu-Welliver, M; Bailey, J; D'Souza, M; Cooper, R; Chandra, S; Seshadri, R; Pegg, A E; Williams, D A

    2000-09-15

    Direct reversal of O6 adducts caused by chemotherapy agents is accomplished in mammalian cells by the protein O6-methylguanine DNA methyltransferase (MGMT). Some tumors overexpress MGMT and are resistant to alkylator therapy. One future approach to treatment of these tumors may rely on concurrent pharmacological depletion of tumor MGMT with O6-benzylguanine (6-BG) and protection of sensitive tissues, such as hematopoietic stem and progenitor cells, using genetic modification with 6-BG-resistant MGMT mutants. We have used retroviral-mediated gene transfer to transduce murine hematopoietic bone marrow cells with MGMT point mutants showing resistance to 6-BG depletion in vitro. These mutants include proline to alanine and proline to lysine substitutions at the 140 position (P140A and P140K, respectively), which show 40- and 1000-fold resistance to 6-BG compared with wild-type (WT) MGMT. Lethally irradiated mice were reconstituted with murine stem cells transduced with murine stem cell virus retrovirus expressing each mutant, WT MGMT, or mock-infected cells and then treated with a combination of 30 mg/kg 6-BG and 10 mg/kg 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) or with 40 mg/kg BCNU alone. Compared with mice treated with BCNU alone, significant myeloid toxicity and death occurred in mice reconstituted with mock-infected or WT MGMT (0.70; no treatment, <0.1). These data demonstrate that mutant MGMT expressed in the bone marrow can protect mice from time- and dose-intensive chemotherapy and that the combination of 6-BG and BCNU leads to uniform selection of transduced stem cells in vivo in mice.

  16. Intracerebral Distribution of the Oncometabolite d-2-Hydroxyglutarate in Mice Bearing Mutant Isocitrate Dehydrogenase Brain Tumors: Implications for Tumorigenesis

    Science.gov (United States)

    Pickard, Amanda J.; Sohn, Albert S. W.; Bartenstein, Thomas F.; He, Shan; Zhang, Yi; Gallo, James M.

    2016-01-01

    The prevalence of mutant isocitrate dehydrogenase 1 (IDH1) brain tumors has generated significant efforts to understand the role of the mutated enzyme product d-2-hydroxyglutarate (D2HG), an oncometabolite, in tumorigenesis, as well as means to eliminate it. Glymphatic clearance was proposed as a pathway that could be manipulated to accelerate D2HG clearance and dictated the study design that consisted of two cohorts of mice bearing U87/mutant IDH1 intracerebral tumors that underwent two microdialysis – providing D2HG interstitial fluid concentrations – sampling periods of awake and asleep (activate glymphatic clearance) in a crossover manner. Glymphatic clearance was found not to have a significant effect on D2HG brain tumor interstitial fluid concentrations that were 126.9 ± 74.8 μM awake and 117.6 ± 98.6 μM asleep. These concentrations, although low relative to total brain tumor concentrations of 6.8 ± 3.6 mM, were considered sufficient to be transported by interstitial fluid and taken up into normal cells to cause deleterious effects. A model of D2HG CNS distribution supported this contention and was further supported by in vitro studies that showed D2HG could interfere with immune cell function. The study provides insight into the compartmental distribution of D2HG in the brain, wherein the interstitial fluid serves as a dynamic pathway for D2HG to enter normal cells and contribute to tumorigenesis. PMID:27781195

  17. Progressive aggregation despite chaperone associations of a mutant SOD1-YFP in transgenic mice that develop ALS.

    Science.gov (United States)

    Wang, Jiou; Farr, George W; Zeiss, Caroline J; Rodriguez-Gil, Diego J; Wilson, Jean H; Furtak, Krystyna; Rutkowski, D Thomas; Kaufman, Randal J; Ruse, Cristian I; Yates, John R; Perrin, Steve; Feany, Mel B; Horwich, Arthur L

    2009-02-03

    Recent studies suggest that superoxide dismutase 1 (SOD1)-linked amyotrophic lateral sclerosis results from destabilization and misfolding of mutant forms of this abundant cytosolic enzyme. Here, we have tracked the expression and fate of a misfolding-prone human SOD1, G85R, fused to YFP, in a line of transgenic G85R SOD1-YFP mice. These mice, but not wild-type human SOD1-YFP transgenics, developed lethal paralyzing motor symptoms at 9 months. In situ RNA hybridization of spinal cords revealed predominant expression in motor neurons in spinal cord gray matter in all transgenic animals. Concordantly, G85R SOD-YFP was diffusely fluorescent in motor neurons of animals at 1 and 6 months of age, but at the time of symptoms, punctate aggregates were observed in cell bodies and processes. Biochemical analyses of spinal cord soluble extracts indicated that G85R SOD-YFP behaved as a misfolded monomer at all ages. It became progressively insoluble at 6 and 9 months of age, associated with presence of soluble oligomers observable by gel filtration. Immunoaffinity capture and mass spectrometry revealed association of G85R SOD-YFP, but not WT SOD-YFP, with the cytosolic chaperone Hsc70 at all ages. In addition, 3 Hsp110's, nucleotide exchange factors for Hsp70s, were captured at 6 and 9 months. Despite such chaperone interactions, G85R SOD-YFP formed insoluble inclusions at late times, containing predominantly intermediate filament proteins. We conclude that motor neurons, initially "compensated" to maintain the misfolded protein in a soluble state, become progressively unable to do so.

  18. Targeting of Fzr/Cdh1 for timely activation of the APC/C at the centrosome during mitotic exit.

    Science.gov (United States)

    Meghini, Francesco; Martins, Torcato; Tait, Xavier; Fujimitsu, Kazuyuki; Yamano, Hiroyuki; Glover, David M; Kimata, Yuu

    2016-08-25

    A multi-subunit ubiquitin ligase, the anaphase-promoting complex/cyclosome (APC/C), regulates critical cellular processes including the cell cycle. To accomplish its diverse functions, APC/C activity must be precisely regulated in time and space. The interphase APC/C activator Fizzy-related (Fzr or Cdh1) is localized at centrosomes in animal cells. However, neither the mechanism of its localization nor its importance is clear. Here we identify the centrosome component Spd2 as a major partner of Fzr in Drosophila. The localization of Fzr to the centriole during interphase depends on direct interaction with Spd2. By generating Spd2 mutants unable to bind Fzr, we show that centrosomal localization of Fzr is essential for optimal APC/C activation towards its centrosomal substrate Aurora A. Finally, we show that Spd2 is also a novel APC/C(Fzr) substrate. Our study is the first to demonstrate the critical importance of distinct subcellular pools of APC/C activators in the spatiotemporal control of APC/C activity.

  19. Intermediate rough Brucella abortus S19Δper mutant is DIVA enable, safe to pregnant guinea pigs and confers protection to mice.

    Science.gov (United States)

    Lalsiamthara, Jonathan; Gogia, Neha; Goswami, Tapas K; Singh, R K; Chaudhuri, Pallab

    2015-05-21

    Brucella abortus S19 is a smooth strain used as live vaccine against bovine brucellosis. Smooth lipopolysaccharide (LPS) is responsible for its residual virulence and serological interference. Rough mutants defective of LPS are more attenuated but confers lower level of protection. We describe a modified B. abortus S19 strain, named as S19Δper, which exhibits intermediate rough phenotype with residual O-polysaccharide (OPS). Deletion of perosamine synthetase gene resulted in substantial attenuation of S19Δper mutant without affecting immunogenic properties. It mounted strong immune response in Swiss albino mice and conferred protection similar to S19 vaccine. Immunized mice produced higher levels of IFN-γ, IgG2a and thus has immune response inclined towards Th1 cell mediated immunity. Sera from immunized animals did not show agglutination reaction with RBPT antigen and thus could serve as DIVA (Differentiating Infected from Vaccinated Animals) vaccine. S19Δper mutant displayed more susceptibility to serum complement mediated killing and sensitivity to polymyxin B. Pregnant guinea pigs injected with S19Δper mutant completed full term of pregnancy and did not cause abortion, still birth or birth of weak offspring. S19Δper mutant with intermediate rough phenotype displayed remarkable resemblance to S19 vaccine strain with improved properties of safety, immunogenicity and DIVA capability for control of bovine brucellosis.

  20. APC implementation in Chandra Asri - ethylene plant

    Science.gov (United States)

    Sidiq, Mochamad; Mustofa, Ali

    2017-05-01

    Nowadays, the modern process plants are continuously improved for maximizing production, Optimization of the energy and raw material and reducing the risk. Due to many disturbances appearance between the process units, hence, the failure of one unit might have a bad effect on the overall productivity. Ethylene Plant have significant opportunities for using Advanced Process Control (APC) technologies to improve operation stability, push closer to quality or equipment limit, and improve the capability of process units to handle disturbances. APC implementation had considered a best answer for solving multivariable control problem. PT. Chandra Asri Petrochemical, Tbk (CAP) operates a large naphtha cracker complex at Cilegon, Indonesia. To optimize the plant operation and to enhance the benefit, Chandra Asri has been decided to implement Advance Process Control (APC) for ethylene plant. The APC implementation technology scopes at CAP are as follows: 1. Hot Section : Furnaces, Quench Tower 2. Cold Section : Demethanizer, Deethanizer, Acetylene Converter, Ethylene Fractionator, Depropanizer, Propylene Fractionator, Debutanizer

  1. Serotonin hyperinnervation and upregulated 5-HT2A receptor expression and motor-stimulating function in nigrostriatal dopamine-deficient Pitx3 mutant mice.

    Science.gov (United States)

    Li, Li; Qiu, Guozhen; Ding, Shengyuan; Zhou, Fu-Ming

    2013-01-23

    The striatum receives serotonin (5-hydroxytryptamine, 5-HT) innervation and expresses 5-HT2A receptors (5-HT2ARs) and other 5-HT receptors, raising the possibility that the striatal 5-HT system may undergo adaptive changes after chronic severe dopamine (DA) loss and contribute to the function and dysfunction of the striatum. Here we show that in transcription factor Pitx3 gene mutant mice with a selective, severe DA loss in the dorsal striatum mimicking the DA denervation in late Parkinson's disease (PD), both the 5-HT innervation and the 5-HT2AR mRNA expression were increased in the dorsal striatum. Functionally, while having no detectable motor effect in wild type mice, the 5-HT2R agonist 2,5-dimethoxy-4-iodoamphetamine increased both the baseline and l-dopa-induced normal ambulatory and dyskinetic movements in Pitx3 mutant mice, whereas the selective 5-HT2AR blocker volinanserin had the opposite effects. These results demonstrate that Pitx3 mutant mice are a convenient and valid mouse model to study the compensatory 5-HT upregulation following the loss of the nigrostriatal DA projection and that the upregulated 5-HT2AR function in the DA deficient dorsal striatum may enhance both normal and dyskinetic movements. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Muscle-wide secretion of a miniaturized form of neural agrin rescues focal neuromuscular innervation in agrin mutant mice

    Science.gov (United States)

    Lin, Shuo; Maj, Marcin; Bezakova, Gabriela; Magyar, Josef P.; Brenner, Hans Rudolf; Ruegg, Markus A.

    2008-01-01

    Agrin and its receptor MuSK are required for the formation of the postsynaptic apparatus at the neuromuscular junction (NMJ). In the current model the local deposition of agrin by the nerve and the resulting local activation of MuSK are responsible for creating and maintaining the postsynaptic apparatus including clusters of acetylcholine receptors (AChRs). Concomitantly, the release of acetylcholine (ACh) and the resulting depolarization disperses those postsynaptic structures that are not apposed by the nerve and thus not stabilized by agrin-MuSK signaling. Here we show that a miniaturized form of agrin, consisting of the laminin-binding and MuSK-activating domains, is sufficient to fully restore NMJs in agrin mutant mice when expressed by developing muscle. Although miniagrin is expressed uniformly throughout muscle fibers and induces ectopic AChR clusters, the size and the number of those AChR clusters contacted by the motor nerve increase during development. We provide experimental evidence that this is due to ACh, because the AChR agonist carbachol stabilizes AChR clusters in organotypic cultures of embryonic diaphragms. In summary, our results show that agrin function in NMJ development requires only two small domains, and that this function does not depend on the local deposition of agrin at synapses. Finally, they suggest a novel local function of ACh in stabilizing postsynaptic structures. PMID:18685098

  3. Over-Expression of Porcine Myostatin Missense Mutant Leads to A Gender Difference in Skeletal Muscle Growth between Transgenic Male and Female Mice

    Directory of Open Access Journals (Sweden)

    Dezun Ma

    2015-08-01

    Full Text Available Myostatin, a transforming growth factor-β family member, is a negative regulator of skeletal muscle development and growth. Piedmontese cattle breeds have a missense mutation, which results in a cysteine to tyrosine substitution in the mature myostatin protein (C313Y. This loss-of-function mutation in myostatin results in a double-muscled phenotype in cattle. Myostatin propeptide is an inhibitor of myostatin activity and is considered a potential agent to stimulate muscle growth in livestock. In this study, we generated transgenic mice overexpressing porcine myostatin missense mutant (pmMS, C313Y, and wild-type porcine myostatin propeptide (ppMS, respectively, to examine their effects on muscle growth in mice. Enhanced muscle growth was observed in both pmMS and ppMS transgenic female mice and also in ppMS transgenic male mice. However, there was no enhanced muscle growth observed in pmMS transgenic male mice. To explore why there is such a big difference in muscle growth between pmMS and ppMS transgenic male mice, the expression level of androgen receptor (AR mutant AR45 was measured by Western blot. Results indicated that AR45 expression significantly increased in pmMS transgenic male mice while it decreased dramatically in ppMS transgenic male mice. Our data demonstrate that both pmMS and ppMS act as myostatin inhibitors in the regulation of muscle growth, but the effect of pmMS in male mice is reversed by an increased AR45 expression. These results provide useful insight and basic theory to future studies on improving pork quality by genetically manipulating myostatin expression or by regulating myostatin activity.

  4. Over-Expression of Porcine Myostatin Missense Mutant Leads to A Gender Difference in Skeletal Muscle Growth between Transgenic Male and Female Mice.

    Science.gov (United States)

    Ma, Dezun; Gao, Pengfei; Qian, Lili; Wang, Qingqing; Cai, Chunbo; Jiang, Shengwang; Xiao, Gaojun; Cui, Wentao

    2015-08-24

    Myostatin, a transforming growth factor-β family member, is a negative regulator of skeletal muscle development and growth. Piedmontese cattle breeds have a missense mutation, which results in a cysteine to tyrosine substitution in the mature myostatin protein (C313Y). This loss-of-function mutation in myostatin results in a double-muscled phenotype in cattle. Myostatin propeptide is an inhibitor of myostatin activity and is considered a potential agent to stimulate muscle growth in livestock. In this study, we generated transgenic mice overexpressing porcine myostatin missense mutant (pmMS), C313Y, and wild-type porcine myostatin propeptide (ppMS), respectively, to examine their effects on muscle growth in mice. Enhanced muscle growth was observed in both pmMS and ppMS transgenic female mice and also in ppMS transgenic male mice. However, there was no enhanced muscle growth observed in pmMS transgenic male mice. To explore why there is such a big difference in muscle growth between pmMS and ppMS transgenic male mice, the expression level of androgen receptor (AR) mutant AR45 was measured by Western blot. Results indicated that AR45 expression significantly increased in pmMS transgenic male mice while it decreased dramatically in ppMS transgenic male mice. Our data demonstrate that both pmMS and ppMS act as myostatin inhibitors in the regulation of muscle growth, but the effect of pmMS in male mice is reversed by an increased AR45 expression. These results provide useful insight and basic theory to future studies on improving pork quality by genetically manipulating myostatin expression or by regulating myostatin activity.

  5. Data sharing system for lithography APC

    Science.gov (United States)

    Kawamura, Eiichi; Teranishi, Yoshiharu; Shimabara, Masanori

    2007-03-01

    We have developed a simple and cost-effective data sharing system between fabs for lithography advanced process control (APC). Lithography APC requires process flow, inter-layer information, history information, mask information and so on. So, inter-APC data sharing system has become necessary when lots are to be processed in multiple fabs (usually two fabs). The development cost and maintenance cost also have to be taken into account. The system handles minimum information necessary to make trend prediction for the lots. Three types of data have to be shared for precise trend prediction. First one is device information of the lots, e.g., process flow of the device and inter-layer information. Second one is mask information from mask suppliers, e.g., pattern characteristics and pattern widths. Last one is history data of the lots. Device information is electronic file and easy to handle. The electronic file is common between APCs and uploaded into the database. As for mask information sharing, mask information described in common format is obtained via Wide Area Network (WAN) from mask-vender will be stored in the mask-information data server. This information is periodically transferred to one specific lithography-APC server and compiled into the database. This lithography-APC server periodically delivers the mask-information to every other lithography-APC server. Process-history data sharing system mainly consists of function of delivering process-history data. In shipping production lots to another fab, the product-related process-history data is delivered by the lithography-APC server from the shipping site. We have confirmed the function and effectiveness of data sharing systems.

  6. Development of an autism severity score for mice using Nlgn4 null mutants as a construct-valid model of heritable monogenic autism.

    Science.gov (United States)

    El-Kordi, Ahmed; Winkler, Daniela; Hammerschmidt, Kurt; Kästner, Anne; Krueger, Dilja; Ronnenberg, Anja; Ritter, Caroline; Jatho, Jasmin; Radyushkin, Konstantin; Bourgeron, Thomas; Fischer, Julia; Brose, Nils; Ehrenreich, Hannelore

    2013-08-15

    Autism is the short name of a complex and heterogeneous group of disorders (autism spectrum disorders, ASD) with several lead symptoms required for classification, including compromised social interaction, reduced verbal communication and stereotyped repetitive behaviors/restricted interests. The etiology of ASD is still unknown in most cases but monogenic heritable forms exist that have provided insights into ASD pathogenesis and have led to the notion of autism as a 'synapse disorder'. Among the most frequent monogenic causes of autism are loss-of-function mutations of the NLGN4X gene which encodes the synaptic cell adhesion protein neuroligin-4X (NLGN4X). We previously described autism-like behaviors in male Nlgn4 null mutant mice, including reduced social interaction and ultrasonic communication. Here, we extend the phenotypical characterization of Nlgn4 null mutant mice to both genders and add a series of additional autism-relevant behavioral readouts. We now report similar social interaction and ultrasonic communication deficits in females as in males. Furthermore, aggression, nest-building parameters, as well as self-grooming and circling as indicators of repetitive behaviors/stereotypies were explored in both genders. The construction of a gender-specific autism severity composite score for Nlgn4 mutant mice markedly diminishes population/sample heterogeneity typically obtained for single tests, resulting in p values of 83% for female mice. Taken together, these data underscore the similarity of phenotypical consequences of Nlgn4/NLGN4X loss-of-function in mouse and man, and emphasize the high relevance of Nlgn4 null mutant mice as an ASD model with both construct and face validity.

  7. Aumento de linfocitos T regulatorios en los ganglios linfoides de ratones mutantes para catepsina L Increase of regulatory T cells in the lymph node of cathepsin L mutant mice

    Directory of Open Access Journals (Sweden)

    Gabriela Camicia

    2011-08-01

    homeostasis. CTSL mutant mice (CTSLnkt/nkt showed a decrease in the absolute number of thymic Treg cells. In contrast, the absolute number of lymph node Treg cells and their frequency within CD4+ cells were increased. The absence of CTSL activity in CD4+ T cells -and not in their environment- increased the proliferation rate of lymph node CD4+ T cells. Treg and T CD4+ conventional (CD4+CD25-Foxp3- cells from mutant mice showed similar increases in their proliferative levels as compared with control mice, suggesting that although proliferation contributes to the increases in their number, the augmentation in the frequency of Treg cells is not only associated to increases in proliferation. Furthermore, the Treg apoptosis rate was not decreased in the lymph node of CTSLnkt/nkt mice. Taking into account that the daily CD4+ thymic production is diminished in mutant mice, our results suggest that peripheral Treg increases are probably not the result of increased thymic output and raise the possibility that a conversion to Treg phenotype would be favored in the CD4+ T cells peripheral pool of CTSL mutant mice.

  8. An APC:WNT counter-current-like mechanism regulates cell division along the colonic crypt axis: a mechanism that explains how APC mutations induce proliferative abnormalities that drive colon cancer development.

    Directory of Open Access Journals (Sweden)

    Bruce M Boman

    2013-11-01

    Full Text Available APC normally down-regulates WNT signaling in human colon, and APC mutations cause proliferative abnormalities in premalignant crypts leading to colon cancer, but the mechanisms are unclear at the level of spatial and functional organization of the crypt. Accordingly, we postulated a counter-current-like mechanism based on gradients of factors (APC;WNT that regulate colonocyte proliferation along the crypt axis. During crypt renewal, stem cells (SCs at the crypt bottom generate non-SC daughter cells that proliferate and differentiate while migrating upwards. The APC concentration is low at the crypt bottom and high at the top (where differentiated cells reside. WNT signaling, in contrast, is high at the bottom (where SCs reside and low at the top. Given that WNT and APC gradients are counter to one another, we hypothesized that a counter-current-like mechanism exists. Since both APC and WNT signaling components (e.g. survivin are required for mitosis, this mechanism establishes a zone in the lower crypt where conditions are optimal for maximal cell division and mitosis orientation (symmetric versus asymmetric. APC haploinsufficiency diminishes the APC gradient, shifts the proliferative zone upwards, and increases symmetric division, which causes SC overpopulation. In homozygote mutant crypts, these changes are exacerbated. Thus, APC-mutation-induced changes in the counter-current-like mechanism cause expansion of proliferative populations (SCs, rapidly-proliferating cells during tumorigenesis. We propose this mechanism also drives crypt fission, functions in the crypt cycle, and underlies adenoma development. Novel chemoprevention approaches designed to normalize the two gradients and readjust the proliferative zone downwards, might thwart progression of these premalignant changes.

  9. Phenotype of transgenic mice carrying a very low copy number of the mutant human G93A superoxide dismutase-1 gene associated with amyotrophic lateral sclerosis.

    Directory of Open Access Journals (Sweden)

    Jeffrey S Deitch

    Full Text Available Amyotrophic lateral sclerosis (ALS is a progressive neurodegenerative disease of the motor neuron. While most cases of ALS are sporadic, 10% are familial (FALS with 20% of FALS caused by a mutation in the gene that codes for the enzyme Cu/Zn superoxide dismutase (SOD1. There is variability in sporadic ALS as well as FALS where even within the same family some siblings with the same mutation do not manifest disease. A transgenic (Tg mouse model of FALS containing 25 copies of the mutant human SOD1 gene demonstrates motor neuron pathology and progressive weakness similar to ALS patients, leading to death at approximately 130 days. The onset of symptoms and survival of these transgenic mice are directly related to the number of copies of the mutant gene. We report the phenotype of a very low expressing (VLE G93A SOD1 Tg carrying only 4 copies of the mutant G93ASOD1 gene. While weakness can start at 9 months, only 74% of mice 18 months or older demonstrate disease. The VLE mice show decreased motor neurons compared to wild-type mice as well as increased cytoplasmic translocation of TDP-43. In contrast to the standard G93A SOD1 Tg mouse which always develops motor weakness leading to death, not all VLE animals manifested clinical disease or shortened life span. In fact, approximately 20% of mice older than 24 months had no motor symptoms and only 18% of VLE mice older than 22 months reached end stage. Given the variable penetrance of clinical phenotype, prolonged survival, and protracted loss of motor neurons the VLE mouse provides a new tool that closely mimics human ALS. This tool will allow the study of pathologic events over time as well as the study of genetic and environmental modifiers that may not be causative, but can exacerbate or accelerate motor neuron disease.

  10. Optic nerve compression and retinal degeneration in Tcirg1 mutant mice lacking the vacuolar-type H-ATPase a3 subunit.

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    Nobuyuki Kawamura

    Full Text Available BACKGROUND: Vacuolar-type proton transporting ATPase (V-ATPase is involved in the proper development of visual function. Mutations in the Tcirg1 (also known as Atp6V0a3 locus, which encodes the a3 subunit of V-ATPase, cause severe autosomal recessive osteopetrosis (ARO in humans. ARO is often associated with impaired vision most likely because of nerve compression at the optic canal. We examined the ocular phenotype of mice deficient in Tcirg1 function. METHODOLOGY/PRINCIPAL FINDINGS: X-ray microtomography showed narrowed foramina in the skull, suggesting that optic nerve compression occurred in the a3-deficient (Tcirg1-/- mice. The retina of the mutant mice had normal architecture, but the number of apoptotic cells was increased at 2-3 wks after birth. In the ocular system, the a3 subunit accumulated in the choriocapillary meshwork in uveal tissues. Two other subunit isoforms a1 and a2 accumulated in the retinal photoreceptor layer. We found that the a4 subunit, whose expression has previously been shown to be restricted to several transporting epithelia, was enriched in pigmented epithelial cells of the retina and ciliary bodies. The expression of a4 in the uveal tissue was below the level of detection in wild-type mice, but it was increased in the mutant choriocapillary meshwork, suggesting that compensation may have occurred among the a subunit isoforms in the mutant tissues. CONCLUSIONS: Our findings suggest that a similar etiology of visual impairment is involved in both humans and mice; thus, a3-deficient mice may provide a suitable model for clinical and diagnostic purposes in cases of ARO.

  11. Msh2 acts in medium-spiny striatal neurons as an enhancer of CAG instability and mutant huntingtin phenotypes in Huntington's disease knock-in mice.

    Science.gov (United States)

    Kovalenko, Marina; Dragileva, Ella; St Claire, Jason; Gillis, Tammy; Guide, Jolene R; New, Jaclyn; Dong, Hualing; Kucherlapati, Raju; Kucherlapati, Melanie H; Ehrlich, Michelle E; Lee, Jong-Min; Wheeler, Vanessa C

    2012-01-01

    The CAG trinucleotide repeat mutation in the Huntington's disease gene (HTT) exhibits age-dependent tissue-specific expansion that correlates with disease onset in patients, implicating somatic expansion as a disease modifier and potential therapeutic target. Somatic HTT CAG expansion is critically dependent on proteins in the mismatch repair (MMR) pathway. To gain further insight into mechanisms of somatic expansion and the relationship of somatic expansion to the disease process in selectively vulnerable MSNs we have crossed HTT CAG knock-in mice (HdhQ111) with mice carrying a conditional (floxed) Msh2 allele and D9-Cre transgenic mice, in which Cre recombinase is expressed specifically in MSNs within the striatum. Deletion of Msh2 in MSNs eliminated Msh2 protein in those neurons. We demonstrate that MSN-specific deletion of Msh2 was sufficient to eliminate the vast majority of striatal HTT CAG expansions in HdhQ111 mice. Furthermore, MSN-specific deletion of Msh2 modified two mutant huntingtin phenotypes: the early nuclear localization of diffusely immunostaining mutant huntingtin was slowed; and the later development of intranuclear huntingtin inclusions was dramatically inhibited. Therefore, Msh2 acts within MSNs as a genetic enhancer both of somatic HTT CAG expansions and of HTT CAG-dependent phenotypes in mice. These data suggest that the selective vulnerability of MSNs may be at least in part contributed by the propensity for somatic expansion in these neurons, and imply that intervening in the expansion process is likely to have therapeutic benefit.

  12. Following EAU recovery there is an associated MC5r-dependent APC induction of regulatory immunity in the spleen.

    Science.gov (United States)

    Lee, Darren J; Taylor, Andrew W

    2011-11-17

    IRBPp-specific regulatory immunity is found in the spleens of mice recovered from experimental autoimmune uveoretinitis (EAU). Induction of this regulatory immunity is dependent on the expression of the melanocortin 5 receptor (MC5r). Therefore, the authors investigated whether dependence on the expression of MC5r was with the T cells or with the APCs mediating protective regulatory immunity in the EAU-recovered mouse spleen. Wild-type and MC5r-/- mice were immunized to induce EAU. The IRBPp-stimulated T-cell response in spleens of wild-type and MC5r-/- mice were compared for surface markers and cytokine production. Spleen APC were isolated and used to stimulate cytokine production and regulatory activity in IRBP-specific T cells from wild-type or MC5r-/- mice assayed in culture by ELISA, by flow cytometry, and in vivo by adoptive transfer into EAU mice. IRBPp-specific CD25+CD4+ T cells from spleens of EAU-recovered wild-type mice express a Treg cell phenotype of FoxP3 and TGF-β compared with the effector T-cell phenotype of IFN-γ and IL-17 production in EAU-recovered MC5r-/- mice. APCs from the spleens of wild-type mice recovering from EAU promoted regulatory T-cell activation in IRBP-specific effector T cells from the spleens of EAU-recovering MC5r-/- mice. Spleen APCs from EAU-recovering wild-type, but not MC5r-/-, mice induced TGF-β expression by primed IRBP-specific effector T cells. Dependence on MC5r expression is with an APC that promotes or selectively activates IRBP-specific FoxP3+ TGF-β+ CD25+CD4+ Treg cells in the spleens of EAU-recovered mice.

  13. The pro-apoptotic K-Ras 4A proto-oncoprotein does not affect tumorigenesis in the ApcMin/+ mouse small intestine

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    Berry Rachel L

    2008-06-01

    Full Text Available Abstract Background Alterations in gene splicing occur in human sporadic colorectal cancer (CRC and may contribute to tumour progression. The K-ras proto-oncogene encodes two splice variants, K-ras 4A and 4B, and K-ras activating mutations which jointly affect both isoforms are prevalent in CRC. Past studies have established that splicing of both the K-ras oncogene and proto-oncogene is altered in CRC in favour of K-ras 4B. The present study addressed whether the K-Ras 4A proto-oncoprotein can suppress tumour development in the absence of its oncogenic allele, utilising the ApcMin/+ (Min mouse that spontaneously develops intestinal tumours that do not harbour K-ras activating mutations, and the K-rastmΔ4A/tmΔ4A mouse that can express the K-ras 4B splice variant only. By this means tumorigenesis in the small intestine was compared between ApcMin/+, K-ras+/+ and ApcMin/+, K-rastmΔ4A/tmΔ4A mice that can, and cannot, express the K-ras 4A proto-oncoprotein respectively. Methods The relative levels of expression of the K-ras splice variants in normal small intestine and small intestinal tumours were quantified by real-time RT-qPCR analysis. Inbred (C57BL/6 ApcMin/+, K-ras+/+ and ApcMin/+, K-rastmΔ4A/tmΔ4A mice were generated and the genotypes confirmed by PCR analysis. Survival of stocks was compared by the Mantel-Haenszel test, and tumour number and area compared by Student's t-test in outwardly healthy mice at approximately 106 and 152 days of age. DNA sequencing of codons 12, 13 and 61 was performed to confirm the intestinal tumours did not harbour a K-ras activating mutation. Results The K-ras 4A transcript accounted for about 50% of K-ras expressed in the small intestine of both wild-type and Min mice. Tumours in the small intestine of Min mice showed increased levels of K-ras 4B transcript expression, but no appreciable change in K-ras 4A transcript levels. No K-ras activating mutations were detected in 27 intestinal tumours derived from

  14. Chemoprevention of colorectal cancer by targeting APC-deficient cells for apoptosis.

    Science.gov (United States)

    Zhang, Ling; Ren, Xiaoyang; Alt, Eckhard; Bai, Xiaowen; Huang, Shaoyi; Xu, Zhengming; Lynch, Patrick M; Moyer, Mary P; Wen, Xian-Feng; Wu, Xiangwei

    2010-04-15

    Cancer chemoprevention uses natural, synthetic, or biological substances to reverse, suppress, or prevent either the initial phase of carcinogenesis or the progression of neoplastic cells to cancer. It holds promise for overcoming problems associated with the treatment of late-stage cancers. However, the broad application of chemoprevention is compromised at present by limited effectiveness and potential toxicity. To overcome these challenges, here we developed a new chemoprevention approach that specifically targets premalignant tumour cells for apoptosis. We show that a deficiency in the adenomatous polyposis coli (APC) gene and subsequent activation of beta-catenin lead to the repression of cellular caspase-8 inhibitor c-FLIP (also known as CFLAR) expression through activation of c-Myc, and that all-trans-retinyl acetate (RAc) independently upregulates tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) death receptors and suppresses decoy receptors. Thus, the combination of TRAIL and RAc induces apoptosis in APC-deficient premalignant cells without affecting normal cells in vitro. In addition, we show that short-term and non-continuous TRAIL and RAc treatment induce apoptosis specifically in intestinal polyps, strongly inhibit tumour growth, and prolong survival in multiple intestinal neoplasms C57BL/6J-Apc(Min)/J (Apc(Min)) mice. With our approach, we further demonstrate that TRAIL and RAc induce significant cell death in human colon polyps, providing a potentially selective approach for colorectal cancer chemoprevention by targeting APC-deficient cells for apoptosis.

  15. Rational design of a live attenuated dengue vaccine: 2'-o-methyltransferase mutants are highly attenuated and immunogenic in mice and macaques.

    Directory of Open Access Journals (Sweden)

    Roland Züst

    Full Text Available Dengue virus is transmitted by Aedes mosquitoes and infects at least 100 million people every year. Progressive urbanization in Asia and South-Central America and the geographic expansion of Aedes mosquito habitats have accelerated the global spread of dengue, resulting in a continuously increasing number of cases. A cost-effective, safe vaccine conferring protection with ideally a single injection could stop dengue transmission. Current vaccine candidates require several booster injections or do not provide protection against all four serotypes. Here we demonstrate that dengue virus mutants lacking 2'-O-methyltransferase activity are highly sensitive to type I IFN inhibition. The mutant viruses are attenuated in mice and rhesus monkeys and elicit a strong adaptive immune response. Monkeys immunized with a single dose of 2'-O-methyltransferase mutant virus showed 100% sero-conversion even when a dose as low as 1,000 plaque forming units was administrated. Animals were fully protected against a homologous challenge. Furthermore, mosquitoes feeding on blood containing the mutant virus were not infected, whereas those feeding on blood containing wild-type virus were infected and thus able to transmit it. These results show the potential of 2'-O-methyltransferase mutant virus as a safe, rationally designed dengue vaccine that restrains itself due to the increased susceptibility to the host's innate immune response.

  16. Structure of an APC3–APC16 Complex: Insights into Assembly of the Anaphase-Promoting Complex/Cyclosome

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, Masaya; Yu, Shanshan; Qiao, Renping; Weissmann, Florian; Miller, Darcie J.; VanderLinden, Ryan; Brown, Nicholas G.; Frye, Jeremiah J.; Peters, Jan-Michael; Schulman, Brenda A. (SJCH); (IMP)

    2015-08-21

    The anaphase-promoting complex/cyclosome (APC/C) is a massive E3 ligase that controls mitosis by catalyzing ubiquitination of key cell cycle regulatory proteins. The APC/C assembly contains two subcomplexes: the “Platform” centers around a cullin-RING-like E3 ligase catalytic core; the “Arc Lamp” is a hub that mediates transient association with regulators and ubiquitination substrates. The Arc Lamp contains the small subunits APC16, CDC26, and APC13, and tetratricopeptide repeat (TPR) proteins (APC7, APC3, APC6, and APC8) that homodimerize and stack with quasi-2-fold symmetry. Within the APC/C complex, APC3 serves as center for regulation. APC3's TPR motifs recruit substrate-binding coactivators, CDC20 and CDH1, via their C-terminal conserved Ile-Arg (IR) tail sequences. Human APC3 also binds APC16 and APC7 and contains a > 200-residue loop that is heavily phosphorylated during mitosis, although the basis for APC3 interactions and whether loop phosphorylation is required for ubiquitination are unclear. Here, we map the basis for human APC3 assembly with APC16 and APC7, report crystal structures of APC3Δloop alone and in complex with the C-terminal domain of APC16, and test roles of APC3's loop and IR tail binding surfaces in APC/C-catalyzed ubiquitination. The structures show how one APC16 binds asymmetrically to the symmetric APC3 dimer and, together with biochemistry and prior data, explain how APC16 recruits APC7 to APC3, show how APC3's C-terminal domain is rearranged in the full APC/C assembly, and visualize residues in the IR tail binding cleft important for coactivator-dependent ubiquitination. Overall, the results provide insights into assembly, regulation, and interactions of TPR proteins and the APC/C.

  17. Alterations in grooming activity and syntax in heterozygous SERT and BDNF knockout mice: the utility of behavior-recognition tools to characterize mutant mouse phenotypes.

    Science.gov (United States)

    Kyzar, Evan J; Pham, Mimi; Roth, Andrew; Cachat, Jonathan; Green, Jeremy; Gaikwad, Siddharth; Kalueff, Allan V

    2012-12-01

    Serotonin transporter (SERT) and brain-derived neurotrophic factor (BDNF) are key modulators of molecular signaling, cognition and behavior. Although SERT and BDNF mutant mouse phenotypes have been extensively characterized, little is known about their self-grooming behavior. Grooming represents an important behavioral domain sensitive to environmental stimuli and is increasingly used as a model for repetitive behavioral syndromes, such as autism and attention deficit/hyperactivity disorder. The present study used heterozygous ((+/-)) SERT and BDNF male mutant mice on a C57BL/6J background and assessed their spontaneous self-grooming behavior applying both manual and automated techniques. Overall, SERT(+/-) mice displayed a general increase in grooming behavior, as indicated by more grooming bouts and more transitions between specific grooming stages. SERT(+/-) mice also aborted more grooming bouts, but showed generally unaltered activity levels in the observation chamber. In contrast, BDNF(+/-) mice displayed a global reduction in grooming activity, with fewer bouts and transitions between specific grooming stages, altered grooming syntax, as well as hypolocomotion and increased turning behavior. Finally, grooming data collected by manual and automated methods (HomeCageScan) significantly correlated in our experiments, confirming the utility of automated high-throughput quantification of grooming behaviors in various genetic mouse models with increased or decreased grooming phenotypes. Taken together, these findings indicate that mouse self-grooming behavior is a reliable behavioral biomarker of genetic deficits in SERT and BDNF pathways, and can be reliably measured using automated behavior-recognition technology.

  18. Phenotypic characterization of skeletal abnormalities of osteopotentia mutant mice by micro-CT: a descriptive approach with emphasis on reconstruction techniques

    Energy Technology Data Exchange (ETDEWEB)

    Roemer, Frank W. [Department of Radiology, Klinikum Augsburg, Augsburg (Germany); Boston University School of Medicine, Quantitative Imaging Center, Boston, MA (United States); University of California, San Francisco, Osteoporosis and Arthritis Research Group, San Francisco, CA (United States); Boston University Medical Center, Department of Radiology, Boston, MA (United States); Mohr, Andreas [University of California, San Francisco, Osteoporosis and Arthritis Research Group, San Francisco, CA (United States); Sligo General Hospital, Department of Radiology, Sligo (Ireland); Guermazi, Ali [Boston University School of Medicine, Quantitative Imaging Center, Boston, MA (United States); University of California, San Francisco, Osteoporosis and Arthritis Research Group, San Francisco, CA (United States); Jiang, Yebin [University of California, San Francisco, Osteoporosis and Arthritis Research Group, San Francisco, CA (United States); University of Michigan Medical School, Osteoporosis and Arthritis Laboratory, Musculoskeletal Division, Department of Radiology, Ann Arbor, MI (United States); Schlechtweg, Philipp [University of Erlangen, Department of Radiology, Erlangen (Germany); Genant, Harry K. [University of California, San Francisco, Osteoporosis and Arthritis Research Group, San Francisco, CA (United States); CCBR-SYNARC, Inc., San Francisco, CA (United States); Sohaskey, Michael L. [University of California, Berkeley, Department of Molecular and Cell Biology and Center for Integrative Genomics, Berkeley, CA (United States)

    2011-08-15

    The novel protein osteopotentia (Opt) has recently been described as an essential regulator of postnatal osteoblast maturation and might possibly be responsible for some of the rarer types of osteogenesis imperfecta. Our aim was the evaluation of micro CT for the qualitative morphological assessment of skeletal abnormalities of Osteopotentia-mutant mice in comparison to radiography and histology. Four homozygous mice with insertional mutations in the Opt gene and three wild-type controls were examined ex vivo using radiography and micro-CT. Two of the homozygous animals were evaluated histologically (trichrome reagent). For the micro-CT evaluation three-dimensional (3D) surface reconstructions and two-dimensional (2D) multiplanar reformations (MPRs) were applied. The Opt-homozygous mice exhibited severe growth. The radiographic examinations showed osteopenia and fractures with hypertrophic callus formation and pseudarthroses of the forelimbs and ribs. Micro-CT confirmed these findings and was able to demonstrate additional fractures especially at smaller bones such as the metacarpals and phalanges. Additional characterization and superior delineation of cortices and fracture fragments was achieved by 2D MPRs. Histological correlation verified several of these imaging findings. Micro-CT is able to screen Opt-mutant mice for osseous pathologies and furthermore characterize these anomalies. The modality seems superior to conventional radiography, but is not able to demonstrate cellular pathology. However, histology is destructive and more time- and material-consuming than micro-CT. Additional information may be gathered by 2D MPRs. (orig.)

  19. A human FSHB transgene encoding the double N-glycosylation mutant (Asn(7Δ) Asn(24Δ)) FSHβ subunit fails to rescue Fshb null mice.

    Science.gov (United States)

    Wang, Huizhen; Butnev, Vladimir; Bousfield, George R; Kumar, T Rajendra

    2016-05-05

    Follicle-stimulating hormone (FSH) is a gonadotrope-derived heterodimeric glycoprotein. Both the common α- and hormone-specific β subunits contain Asn-linked N-glycan chains. Recently, macroheterogeneous FSH glycoforms consisting of β-subunits that differ in N-glycan number were identified in pituitaries of several species and subsequently the recombinant human FSH glycoforms biochemically characterized. Although chemical modification and in vitro site-directed mutagenesis studies defined the roles of N-glycans on gonadotropin subunits, in vivo functional analyses in a whole-animal setting are lacking. Here, we have generated transgenic mice with gonadotrope-specific expression of either an HFSHB(WT) transgene that encodes human FSHβ WT subunit or an HFSHB(dgc) transgene that encodes a human FSHβ(Asn7Δ 24Δ) double N-glycosylation site mutant subunit, and separately introduced these transgenes onto Fshb null background using a genetic rescue strategy. We demonstrate that the human FSHβ(Asn7Δ 24Δ) double N-glycosylation site mutant subunit, unlike human FSHβ WT subunit, inefficiently combines with the mouse α-subunit in pituitaries of Fshb null mice. FSH dimer containing this mutant FSHβ subunit is inefficiently secreted with very low levels detectable in serum. Fshb null male mice expressing HFSHB(dgc) transgene are fertile and exhibit testis tubule size and sperm number similar to those of Fshb null mice. Fshb null female mice expressing the mutant, but not WT human FSHβ subunit-containing FSH dimer are infertile, demonstrate no evidence of estrus cycles, and many of the FSH-responsive genes remain suppressed in their ovaries. Thus, HFSHB(dgc) unlike HFSHB(WT) transgene does not rescue Fshb null mice. Our genetic approach provides direct in vivo evidence that N-linked glycans on FSHβ subunit are essential for its efficient assembly with the α-subunit to form FSH heterodimer in pituitary. Our studies also reveal that N-glycans on FSHβ subunit are

  20. Investigation of iron metabolism in mice expressing a mutant Menke's copper transporting ATPase (Atp7a protein with diminished activity (Brindled; Mo (Br (/y .

    Directory of Open Access Journals (Sweden)

    Sukru Gulec

    Full Text Available During iron deficiency, perturbations in copper homeostasis have frequently been documented. Previous studies in iron-deprived rats demonstrated that enterocyte and hepatic copper levels increase and a copper transporter (the Menkes Copper ATPase; Atp7a is induced in the duodenal epithelium in parallel to iron transport-related genes (e.g. Dmt1, Dcytb, Fpn1. Moreover, two ferroxidase proteins involved in iron homeostasis, hephaestin expressed in enterocytes and ceruloplasmin, produced and secreted into blood by the liver, are copper-dependent enzymes. We thus aimed to test the hypothesis that Atp7a function is important for the copper-related compensatory response of the intestinal epithelium to iron deficiency. Accordingly, iron homeostasis was studied for the first time in mice expressing a mutant Atp7a protein with minimal activity (Brindled [Mo (Br (/y ]. Mutant mice were rescued by perinatal copper injections, and, after a 7-8 week recovery period, were deprived of dietary iron for 3 weeks (along with WT littermates. Adult Mo (Br (/y mice displayed copper-deficiency anemia but had normal iron status; in contrast, iron-deprived Mo (Br (/y mice were iron deficient and more severely anemic with partial amelioration of the copper-deficient phenotype. Intestinal iron absorption in both genotypes (WT and Mo (Br (/y increased ∼3-fold when mice consumed a low-iron diet and ∼6-fold when mice were concurrently bled. WT mice exhibited no alterations in copper homeostasis in response to iron deprivation or phlebotomy. Conversely, upregulation of iron absorption was associated with increased enterocyte and liver copper levels and serum ferroxidase (ceruloplasmin activity in Mo (Br (/y mice, typifying the response to iron deprivation in many mammalian species. We thus speculate that a copper threshold exists that is necessary to allow appropriate regulate of iron absorption. In summary, Mo (Br (/y mice were able to adequately regulate iron absorption

  1. Expression of a mutant p53 results in an age-related demographic shift in spontaneous lung tumor formation in transgenic mice.

    Directory of Open Access Journals (Sweden)

    Wenrui Duan

    Full Text Available BACKGROUND: Mutations in the P53 gene are among the most common genetic abnormalities in human lung cancer. Codon 273 in the sequence-specific DNA binding domain is one of the most frequently mutated sites. METHODOLOGY: To investigate the role of mutant p53 in lung tumorigenesis, a lung specific p53(273H transgenic mouse model was developed. Rates of lung cancer formation in the transgenic animals and their littermates were evaluated by necropsy studies performed in progressive age cohorts ranging from 4 to 24 months. In order to establish the influence of other common genetic abnormalities in lung tumor formation in the animals, K-Ras gene mutation and p16INK4a (p16 promoter methylation were evaluated in a total of 281 transgenic mice and 189 non-transgenic littermates. PRINCIPAL FINDINGS: At the age extremes of 4-12 and 22-24 months no differences were observed, with very low prevalence of tumors in animals younger than 12 months, and a relatively high prevalence at age 22 months or older. However, the transgenic mice had a significant higher lung tumor rate than their non-transgenic counterparts during the age of 13-21 months, suggesting an age-related shift in lung tumor formation induced by the lung-specific expression of the human mutant p53. Histopathology suggested a more aggressive nature for the transgenic tumors. Older mice (>13 months had a significantly higher rate of p16 promoter methylation (17% v 82%. In addition, an age related effect was observed for K-Ras codons 12 or 13 mutations, but not for codon 61 mutations. CONCLUSIONS/SIGNIFICANCE: These results would suggest that the mutant p53(273H contributes to an acceleration in the development of spontaneous lung tumors in these mice. Combination with other genetic and epigenetic alterations occurring after the age of 13 months is intimately linked to its oncogenic potential.

  2. A model of sensitivity: 1,3-butadiene increases mutant frequencies and genomic damage in mice lacking a functional microsomal epoxide hydrolase gene.

    Science.gov (United States)

    Wickliffe, Jeffrey K; Ammenheuser, Marinel M; Salazar, James J; Abdel-Rahman, Sherif Z; Hastings-Smith, Darlene A; Postlethwait, Edward M; Lloyd, R Stephen; Ward, Jonathan B

    2003-01-01

    The specific role that polymorphisms in xenobiotic metabolizing enzymes play in modulating sensitivity to 1,3-butadiene (BD) genotoxicity has been relatively unexplored. The enzyme microsomal epoxide hydrolase (mEH) is important in detoxifying the mutagenic epoxides of BD (butadiene monoepoxide [BDO], butadiene diepoxide [BDO(2)]). Polymorphisms in the human mEH gene appear to affect the function of the enzyme. We exposed mice with normal mEH activity (WT) and knockout mice without mEH activity (KO) to 20 ppm BD (inhalation) or 30 mg/kg BDO(2) (intraperitoneal [IP] injection). We then compared Hprt mutant frequencies (MFs) among these groups. KO mice exposed to BD exhibited a significant (P damage in WT and KO mice (comet tail moment) following IP exposure to 3 mg/kg and 30 mg/kg BDO(2). KO mice exposed to 3 mg/kg exhibited significantly more DNA damage than controls (7.5-12.1-fold increase) and exposed WT mice (3 mg/kg; 4.8-fold increase). KO mice exposed to 30 mg/kg BDO(2) exhibited significantly more DNA damage than all other groups (2.3-27.9-fold increase). Correlation analysis indicated that a significant, positive relationship (r(2) = 0.92) exists between comet-measured damage and Hprt MFs. The lack of mEH activity increases the genetic sensitivity of mice exposed to BD and BDO(2). This model should facilitate a mechanistic understanding of the observed variation in human genetic sensitivity following exposure to BD.

  3. Msh2 acts in medium-spiny striatal neurons as an enhancer of CAG instability and mutant huntingtin phenotypes in Huntington's disease knock-in mice.

    Directory of Open Access Journals (Sweden)

    Marina Kovalenko

    Full Text Available The CAG trinucleotide repeat mutation in the Huntington's disease gene (HTT exhibits age-dependent tissue-specific expansion that correlates with disease onset in patients, implicating somatic expansion as a disease modifier and potential therapeutic target. Somatic HTT CAG expansion is critically dependent on proteins in the mismatch repair (MMR pathway. To gain further insight into mechanisms of somatic expansion and the relationship of somatic expansion to the disease process in selectively vulnerable MSNs we have crossed HTT CAG knock-in mice (HdhQ111 with mice carrying a conditional (floxed Msh2 allele and D9-Cre transgenic mice, in which Cre recombinase is expressed specifically in MSNs within the striatum. Deletion of Msh2 in MSNs eliminated Msh2 protein in those neurons. We demonstrate that MSN-specific deletion of Msh2 was sufficient to eliminate the vast majority of striatal HTT CAG expansions in HdhQ111 mice. Furthermore, MSN-specific deletion of Msh2 modified two mutant huntingtin phenotypes: the early nuclear localization of diffusely immunostaining mutant huntingtin was slowed; and the later development of intranuclear huntingtin inclusions was dramatically inhibited. Therefore, Msh2 acts within MSNs as a genetic enhancer both of somatic HTT CAG expansions and of HTT CAG-dependent phenotypes in mice. These data suggest that the selective vulnerability of MSNs may be at least in part contributed by the propensity for somatic expansion in these neurons, and imply that intervening in the expansion process is likely to have therapeutic benefit.

  4. The subcutaneous inoculation of pH 6 antigen mutants of Yersinia pestis does not affect virulence and immune response in mice.

    Science.gov (United States)

    Anisimov, Andrey P; Bakhteeva, Irina V; Panfertsev, Evgeniy A; Svetoch, Tat'yana E; Kravchenko, Tat'yana B; Platonov, Mikhail E; Titareva, Galina M; Kombarova, Tat'yana I; Ivanov, Sergey A; Rakin, Alexander V; Amoako, Kingsley K; Dentovskaya, Svetlana V

    2009-01-01

    Two isogenic sets of Yersinia pestis strains were generated, composed of wild-type strains 231 and I-1996, their non-polar pH 6(-) mutants with deletions in the psaA gene that codes for its structural subunit or the whole operon, as well as strains with restored ability for temperature- and pH-dependent synthesis of adhesion pili or constitutive production of pH 6 antigen. The mutants were generated by site-directed mutagenesis of the psa operon and subsequent complementation in trans. It was shown that the loss of synthesis or constitutive production of pH 6 antigen did not influence Y. pestis virulence or the average survival time of subcutaneously inoculated BALB/c naïve mice or animals immunized with this antigen.

  5. Short-term carcinogenicity testing of a potent murine intestinal mutagen, 2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine (PhIP), in Apc1638N transgenic mice

    DEFF Research Database (Denmark)

    Sørensen, Ilona Kryspin; Kristiansen, E.; Mortensen, Alicja;

    1997-01-01

    others, mammary tumors, We have studied these mice in a short-term carcinogenicity test with 2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine (PhIP), a potent murine small intestinal mutagen and lymphomagen. Upon dietary administration of 0.03% PhIP in a short-term (6 months) study, a significantly...

  6. Increased biomass production and glycogen accumulation in apcE gene deleted Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Joseph, Ancy; Aikawa, Shimpei; Sasaki, Kengo; Matsuda, Fumio; Hasunuma, Tomohisa; Kondo, Akihiko

    2014-01-01

    The effect of phycobilisome antenna-truncation in the cyanobacterium Synechocystis sp. PCC 6803 on biomass production and glycogen accumulation have not yet been fully clarified. To investigate these effects here, the apcE gene, which encodes the anchor protein linking the phycobilisome to the thylakoid membrane, was deleted in a glucose tolerant strain of Synechocystis sp. PCC 6803. Biomass production of the apcE-deleted strain under photoautotrophic and atmospheric air conditions was 1.6 times higher than that of strain PCC 6803 (1.32 ± 0.01 versus 0.84 ± 0.07 g cell-dry weight L(-1), respectively) after 15 days of cultivation. In addition, the glycogen content of the apcE-deleted strain (24.2 ± 0.7%) was also higher than that of strain PCC 6803 (11.1 ± 0.3%). Together, these results demonstrate that antenna truncation by deleting the apcE gene was effective for increasing biomass production and glycogen accumulation under photoautotrophic and atmospheric air conditions in Synechocystis sp. PCC 6803.

  7. Subthreshold membrane potential oscillations in inferior olive neurons are dynamically regulated by P/Q- and T-type calcium channels: a study in mutant mice.

    Science.gov (United States)

    Choi, Soonwook; Yu, Eunah; Kim, Daesoo; Urbano, Francisco J; Makarenko, Vladimir; Shin, Hee-Sup; Llinás, Rodolfo R

    2010-08-15

    The role of P/Q- and T-type calcium channels in the rhythmic oscillatory behaviour of inferior olive (IO) neurons was investigated in mutant mice. Mice lacking either the CaV2.1 gene of the pore-forming alpha1A subunit for P/Q-type calcium channel, or the CaV3.1 gene of the pore-forming alpha1G subunit for T-type calcium channel were used. In vitro intracellular recording from IO neurons reveals that the amplitude and frequency of sinusoidal subthreshold oscillations (SSTOs) were reduced in the CaV2.1-/- mice. In the CaV3.1-/- mice, IO neurons also showed altered patterns of SSTOs and the probability of SSTO generation was significantly lower (15%, 5 of 34 neurons) than that of wild-type (78%, 31 of 40 neurons) or CaV2.1-/- mice (73%, 22 of 30 neurons). In addition, the low-threshold calcium spike and the sustained endogenous oscillation following rebound potentials were absent in IO neurons from CaV3.1-/- mice. Moreover, the phase-reset dynamics of oscillatory properties of single neurons and neuronal clusters in IO were remarkably altered in both CaV2.1-/- and CaV3.1-/- mice. These results suggest that both alpha1A P/Q- and alpha1G T-type calcium channels are required for the dynamic control of neuronal oscillations in the IO. These findings were supported by results from a mathematical IO neuronal model that incorporated T and P/Q channel kinetics.

  8. Progressive Motor Deficit is Mediated by the Denervation of Neuromuscular Junctions and Axonal Degeneration in Transgenic Mice Expressing Mutant (P301S) Tau Protein.

    Science.gov (United States)

    Yin, Zhuoran; Valkenburg, Femke; Hornix, Betty E; Mantingh-Otter, Ietje; Zhou, Xingdong; Mari, Muriel; Reggiori, Fulvio; Van Dam, Debby; Eggen, Bart J L; De Deyn, Peter P; Boddeke, Erik

    2017-02-10

    Tauopathies include a variety of neurodegenerative diseases associated with the pathological aggregation of hyperphosphorylated tau, resulting in progressive cognitive decline and motor impairment. The underlying mechanism for motor deficits related to tauopathy is not yet fully understood. Here, we use a novel transgenic tau mouse line, Tau 58/4, with enhanced neuron-specific expression of P301S mutant tau to investigate the motor abnormalities in association with the peripheral nervous system. Using stationary beam, gait, and rotarod tests, motor deficits were found in Tau 58/4 mice already 3 months after birth, which deteriorated during aging. Hyperphosphorylated tau was detected in the cell bodies and axons of motor neurons. At the age of 9 and 12 months, significant denervation of the neuromuscular junction in the extensor digitorum longus muscle was observed in Tau 58/4 mice, compared to wild-type mice. Muscle hypotrophy was observed in Tau 58/4 mice at 9 and 12 months. Using electron microscopy, we observed ultrastructural changes in the sciatic nerve of 12-month-old Tau 58/4 mice indicative of the loss of large axonal fibers and hypomyelination (assessed by g-ratio). We conclude that the accumulated hyperphosphorylated tau in the axon terminals may induce dying-back axonal degeneration, myelin abnormalities, neuromuscular junction denervation, and muscular atrophy, which may be the mechanisms responsible for the deterioration of the motor function in Tau 58/4 mice. Tau 58/4 mice represent an interesting neuromuscular degeneration model, and the pathological mechanisms might be responsible for motor signs observed in some human tauopathies.

  9. Analysis of APC allelic imbalance/loss of heterozygosity and APC protein expression in cutaneous squamous cell carcinomas.

    LENUS (Irish Health Repository)

    Gray, Sarah E

    2012-02-01

    BACKGROUND: The adenomatous polyposis coli (APC) gene is a tumor suppressor gene which is mutated in the hereditary disease, familial adenomatous polyposis (FAP). Somatic mutations of the APC gene have also been identified in the majority of sporadic colorectal carcinomas, and mutation of the APC gene appears to be an early step in the initiation of colon cancer. Loss of heterozygosity (LOH) of APC has been described in a variety of other cancer types, including renal cell carcinoma, gastric cancer, non-small cell lung cancer, endometrial cancer and oral squamous cell carcinomas (SCC). AIM: To determine the role played by APC gene in the genesis of cutaneous SCC. MATERIALS AND METHODS: Allelic imbalance\\/loss of heterozygosity (AI\\/LOH) was examined in twenty-two histologically confirmed cutaneous squamous cell carcinomas (SCC) using microsatellite markers, proximal to the APC gene. Immunohistochemical analysis of APC protein expression was also examined in the cutaneous SCC. RESULTS: AI\\/LOH was detected in 60% of the SCC samples using D5S346 marker (proximal to the APC gene). Ninty-five percent of the SCC samples showed positive reduced APC expression, however the localization of the APC protein was abnormal. CONCLUSION: The abnormal expression of APC suggests that APC gene may play a role in cutaneous SCC development.

  10. DNA adducts, mutant frequencies, and mutation spectra in various organs of λlacZ mice exposed to ethylating agents

    NARCIS (Netherlands)

    Mientjes, E.J.; Luiten-Schuite, A.; Wolf, E. van der; Borsboom, Y.; Bergmans, A.; Berends, F.; Lohman, P.H.M.; Baan, R.A.; Delft, J.H.M. van

    1998-01-01

    To investigate tissue-specific relations between DNA adducts and mutagenesis in vivo, λlacZ transgenic mice were treated i.p. with N-ethyl-N-nitrosourea (ENU), diethylnitrosamine (DEN), and ethyl methanesulphonate (EMS). In liver, bone marrow, and brain DNA from mice sacrificed at several time point

  11. Targeted expression of a protease-resistant IGFBP-4 mutant in smooth muscle of transgenic mice results in IGFBP-4 stabilization and smooth muscle hypotrophy.

    Science.gov (United States)

    Zhang, Mingyu; Smith, Eric P; Kuroda, Hiroaki; Banach, Walter; Chernausek, Steven D; Fagin, James A

    2002-06-14

    The insulin-like growth factor-binding protein 4 (IGFBP-4), the most abundant IGF-binding protein produced by rodent smooth muscle cells (SMC), is degraded by specific protease(s) potentially releasing IGF-I for local bioactivity. IGFBP-4 protease(s) recognizes basic residues within the midregion of the molecule. We constructed a mutant IGFBP-4 with the cleavage domain substitution 119-KHMAKVRDRSKMK-133 to 119-AAMAAVADASAMA-133. Myc-tagged native and IGFBP-4.7A retained equivalent IGF-I binding affinity. Whereas native IGFBP-4 was cleaved by SMC-conditioned medium, IGFBP-4.7A was completely resistant to proteolysis. To explore the function of the protease-resistant IGFBP-4 in vivo, expression of the mutant and native proteins was targeted to SMC of transgenic mice by means of a smooth muscle alpha-actin promoter. Transgene expression was confined to SMC-rich tissues in all lines. Bladder and aortic immunoreactive IGFBP-4/transgene mRNA ratios in SMP8-BP4.7A mice were increased by 2- to 4-fold relative to SMP8-BP4 mice, indicating that the IGFBP-4.7A protein was stabilized in vivo. SMP8-BP4.7A mice had lower aortic, bladder, and stomach weight and intestinal length relative to SMP8-BP4 counterparts matched for protein expression by Western blotting. Thus, IGFBP-4.7A results in greater growth inhibition than equivalent levels of native IGFBP-4 in vivo, demonstrating a role for IGFBP-4 proteolysis in the regulation of IGF-I action.

  12. Regulation of APC/C activators in mitosis and meiosis.

    Science.gov (United States)

    Pesin, Jillian A; Orr-Weaver, Terry L

    2008-01-01

    The anaphase-promoting complex/cyclosome (APC/C) is a multisubunit E3 ubiquitin ligase that triggers the degradation of multiple substrates during mitosis. Cdc20/Fizzy and Cdh1/Fizzy-related activate the APC/C and confer substrate specificity through complex interactions with both the core APC/C and substrate proteins. The regulation of Cdc20 and Cdh1 is critical for proper APC/C activity and occurs in multiple ways: targeted protein degradation, phosphorylation, and direct binding of inhibitory proteins. During the specialized divisions of meiosis, the activity of the APC/C must be modified to achieve proper chromosome segregation. Recent studies show that one way in which APC/C activity is modified is through the use of meiosis-specific APC/C activators. Furthermore, regulation of the APC/C during meiosis is carried out by both mitotic regulators of the APC/C as well as meiosis-specific regulators. Here, we review the regulation of APC/C activators during mitosis and the role and regulation of the APC/C during female meiosis.

  13. Deducing the stage of origin of Wilms' tumours from a developmental series of Wt1-mutant mice

    Directory of Open Access Journals (Sweden)

    Rachel L. Berry

    2015-08-01

    Full Text Available Wilms' tumours, paediatric kidney cancers, are the archetypal example of tumours caused through the disruption of normal development. The genetically best-defined subgroup of Wilms' tumours is the group caused by biallelic loss of the WT1 tumour suppressor gene. Here, we describe a developmental series of mouse models with conditional loss of Wt1 in different stages of nephron development before and after the mesenchymal-to-epithelial transition (MET. We demonstrate that Wt1 is essential for normal development at all kidney developmental stages under study. Comparison of genome-wide expression data from the mutant mouse models with human tumour material of mutant or wild-type WT1 datasets identified the stage of origin of human WT1-mutant tumours, and emphasizes fundamental differences between the two human tumour groups due to different developmental stages of origin.

  14. Fission yeast APC/C activators Slp1 and Fzr1 sequentially trigger two consecutive nuclear divisions during meiosis.

    Science.gov (United States)

    Chikashige, Yuji; Yamane, Miho; Okamasa, Kasumi; Osakada, Hiroko; Tsutsumi, Chihiro; Nagahama, Yuki; Fukuta, Noriko; Haraguchi, Tokuko; Hiraoka, Yasushi

    2017-04-01

    In meiosis, two rounds of nuclear division occur consecutively without DNA replication between the divisions. We isolated a fission yeast mutant in which the nucleus divides only once to generate two spores, as opposed to four, in meiosis. In this mutant, we found that the initiation codon of the slp1(+) gene is converted to ATA, producing a reduced amount of Slp1. As a member of the Fizzy family of anaphase-promoting complex/cyclosome (APC/C) activators, Slp1 is essential for vegetative growth; however, the mutant allele shows a phenotype only in meiosis. Slp1 insufficiency delays degradation of maturation-promoting factor at the first meiotic division, and another APC/C activator, Fzr1, which acts late in meiosis, terminates meiosis immediately after the delayed first division to produce two viable spores. © 2017 Federation of European Biochemical Societies.

  15. Integrated metrology: an enabler for advanced process control (APC)

    Science.gov (United States)

    Schneider, Claus; Pfitzner, Lothar; Ryssel, Heiner

    2001-04-01

    Advanced process control (APC) techniques become more and more important as short innovation cycles in microelectronics and a highly competitive market requires cost-effective solutions in semiconductor manufacturing. APC marks a paradigm shift from statistically based techniques (SPC) using monitor wafers for sampling measurement data towards product wafer control. The APC functionalities including run-to-run control, fault detection, and fault analysis allow to detect process drifts and excursions at an early stage and to minimize the number of misprocessed wafers. APC is being established as part of factory control systems through the definition of an APC framework. A precondition for APC is the availability of sensors and measurement methods providing the necessary wafer data. This paper discusses integrated metrology as an enabler for APC and demonstrates practical implementations in semiconductor manufacturing.

  16. Immunogenicity and Cross-Protective Efficacy Induced by Outer Membrane Proteins from Salmonella Typhimurium Mutants with Truncated LPS in Mice

    Directory of Open Access Journals (Sweden)

    Qiong Liu

    2016-03-01

    Full Text Available Lipopolysaccharide (LPS is a major virulence factor present in the outer membrane of Salmonella enterica serovar Typhimurium (S. Typhimurium. Outer membrane proteins (OMPs from Salmonella show high immunogenicity and provide protection against Salmonella infection, and truncated LPS alters the outer membrane composition of the cell wall. In our previous study, we demonstrated that Salmonella mutants carrying truncated LPS failed to induce strong immune responses and cross-reaction to other enteric bacteria, due to their high attenuation and low colonization in the host. Therefore, we plan to investigate whether outer membrane proteins from Salmonella mutants with truncated LPS resulting from a series of nonpolar mutations, including ∆waaC12, ∆waaF15, ∆waaG42, ∆rfaH49, ∆waaI43, ∆waaJ44, ∆waaL46, ∆wbaP45 and ∆wzy-48, affect immunogenicity and provide protection against diverse Salmonella challenge. In this study, the immunogenicity and cross-protection efficiency of purified OMPs from all mutants were investigated to explore a potential OMP vaccine to protect against homologous or heterologous serotype Salmonella challenge. The results demonstrated that OMPs from three Salmonella mutants (∆waaC12, ∆waaJ44 and ∆waaL46 induced higher immune responses and provided good protection against homologous S. Typhimurium. The OMPs from these three mutants were also selected to determine the cross-protective efficacy against homologous and heterologous serotype Salmonella. Our results indicated that the mutant ∆waaC12 can elicit higher cross-reactivity and can provide good protection against S. Choleraesuis and S. Enteritidis infection and that the cross-reactivity may be ascribed to an antigen of approximately 18.4–30 kDa.

  17. Immunogenicity and Cross-Protective Efficacy Induced by Outer Membrane Proteins from Salmonella Typhimurium Mutants with Truncated LPS in Mice.

    Science.gov (United States)

    Liu, Qiong; Liu, Qing; Zhao, Xinxin; Liu, Tian; Yi, Jie; Liang, Kang; Kong, Qingke

    2016-03-22

    Lipopolysaccharide (LPS) is a major virulence factor present in the outer membrane of Salmonella enterica serovar Typhimurium (S. Typhimurium). Outer membrane proteins (OMPs) from Salmonella show high immunogenicity and provide protection against Salmonella infection, and truncated LPS alters the outer membrane composition of the cell wall. In our previous study, we demonstrated that Salmonella mutants carrying truncated LPS failed to induce strong immune responses and cross-reaction to other enteric bacteria, due to their high attenuation and low colonization in the host. Therefore, we plan to investigate whether outer membrane proteins from Salmonella mutants with truncated LPS resulting from a series of nonpolar mutations, including ∆waaC12, ∆waaF15, ∆waaG42, ∆rfaH49, ∆waaI43, ∆waaJ44, ∆waaL46, ∆wbaP45 and ∆wzy-48, affect immunogenicity and provide protection against diverse Salmonella challenge. In this study, the immunogenicity and cross-protection efficiency of purified OMPs from all mutants were investigated to explore a potential OMP vaccine to protect against homologous or heterologous serotype Salmonella challenge. The results demonstrated that OMPs from three Salmonella mutants (∆waaC12, ∆waaJ44 and ∆waaL46) induced higher immune responses and provided good protection against homologous S. Typhimurium. The OMPs from these three mutants were also selected to determine the cross-protective efficacy against homologous and heterologous serotype Salmonella. Our results indicated that the mutant ∆waaC12 can elicit higher cross-reactivity and can provide good protection against S. Choleraesuis and S. Enteritidis infection and that the cross-reactivity may be ascribed to an antigen of approximately 18.4-30 kDa.

  18. Differential interaction of Apolipoprotein-E isoforms with insulin receptors modulates brain insulin signaling in mutant human amyloid precursor protein transgenic mice.

    Science.gov (United States)

    Chan, Elizabeth S; Chen, Christopher; Cole, Gregory M; Wong, Boon-Seng

    2015-09-08

    It is unclear how human apolipoprotein E4 (ApoE4) increases the risk for Alzheimer's disease (AD). Although Aβ levels can lead to insulin signaling impairment, these experiments were done in the absence of human ApoE. To examine ApoE role, we crossed the human ApoE-targeted replacement mice with mutant human amyloid precursor protein (APP) mice. In 26 week old mice with lower Aβ levels, the expression and phosphorylation of insulin signaling proteins remained comparable among APP, ApoE3xAPP and ApoE4xAPP mouse brains. When the mice aged to 78 weeks, these proteins were markedly reduced in APP and ApoE4xAPP mouse brains. While Aβ can bind to insulin receptor, how ApoE isoforms modulate this interaction remains unknown. Here, we showed that ApoE3 had greater association with insulin receptor as compared to ApoE4, regardless of Aβ42 concentration. In contrast, ApoE4 bound more Aβ42 with increasing peptide levels. Using primary hippocampal neurons, we showed that ApoE3 and ApoE4 neurons are equally sensitive to physiological levels of insulin. However, in the presence of Aβ42, insulin failed to elicit a downstream response only in ApoE4 hippocampal neurons. Taken together, our data show that ApoE genotypes can modulate this Aβ-mediated insulin signaling impairment.

  19. Inflammation in mice ectopically expressing human Pyogenic Arthritis, Pyoderma Gangrenosum, and Acne (PAPA) Syndrome-associated PSTPIP1 A230T mutant proteins.

    Science.gov (United States)

    Wang, Donghai; Höing, Susanne; Patterson, Heide Christine; Ahmad, Umtul M; Rathinam, Vijay A K; Rajewsky, Klaus; Fitzgerald, Katherine A; Golenbock, Douglas T

    2013-02-15

    Pyogenic Arthritis, Pyoderma Gangrenosum, and Acne Syndrome (PAPA syndrome) is an autoinflammatory disease caused by aberrant production of the proinflammatory cytokine interleukin-1. Mutations in the gene encoding proline serine threonine phosphatase-interacting protein-1 (PSTPIP1) have been linked to PAPA syndrome. PSTPIP1 is an adaptor protein that interacts with PYRIN, the protein encoded by the Mediterranean Fever (MEFV) gene whose mutations cause Familial Mediterranean Fever (FMF). However, the pathophysiological function of PSTPIP1 remains to be elucidated. We have generated mouse strains that either are PSTPIP1 deficient or ectopically express mutant PSTPIP1. Results from analyzing these mice suggested that PSTPIP1 is not an essential regulator of the Nlrp3, Aim2, or Nlrc4 inflammasomes. Although common features of human PAPA syndrome such as pyogenic arthritis and skin inflammation were not recapitulated in the mouse model, ectopic expression of the mutant but not the wild type PSTPIP1 in mice lead to partial embryonic lethality, growth retardation, and elevated level of circulating proinflammatory cytokines.

  20. Regulation of GABA(A and glutamate receptor expression, synaptic facilitation and long-term potentiation in the hippocampus of prion mutant mice.

    Directory of Open Access Journals (Sweden)

    Alejandra Rangel

    Full Text Available BACKGROUND: Prionopathies are characterized by spongiform brain degeneration, myoclonia, dementia, and periodic electroencephalographic (EEG disturbances. The hallmark of prioniopathies is the presence of an abnormal conformational isoform (PrP(sc of the natural cellular prion protein (PrP(c encoded by the Prnp gene. Although several roles have been attributed to PrP(c, its putative functions in neuronal excitability are unknown. Although early studies of the behavior of Prnp knockout mice described minor changes, later studies report altered behavior. To date, most functional PrP(c studies on synaptic plasticity have been performed in vitro. To our knowledge, only one electrophysiological study has been performed in vivo in anesthetized mice, by Curtis and coworkers. They reported no significant differences in paired-pulse facilitation or LTP in the CA1 region after Schaffer collateral/commissural pathway stimulation. METHODOLOGY/PRINCIPAL FINDINGS: Here we explore the role of PrP(c expression in neurotransmission and neural excitability using wild-type, Prnp -/- and PrP(c-overexpressing mice (Tg20 strain. By correlating histopathology with electrophysiology in living behaving mice, we demonstrate that both Prnp -/- mice but, more relevantly Tg20 mice show increased susceptibility to KA, leading to significant cell death in the hippocampus. This finding correlates with enhanced synaptic facilitation in paired-pulse experiments and hippocampal LTP in living behaving mutant mice. Gene expression profiling using Illumina microarrays and Ingenuity pathways analysis showed that 129 genes involved in canonical pathways such as Ubiquitination or Neurotransmission were co-regulated in Prnp -/- and Tg20 mice. Lastly, RT-qPCR of neurotransmission-related genes indicated that subunits of GABA(A and AMPA-kainate receptors are co-regulated in both Prnp -/- and Tg20 mice. CONCLUSIONS/SIGNIFICANCE: Present results demonstrate that PrP(c is necessary for the

  1. Electroretinographic analyses of Rpe65-mutant rd12 mice: developing an in vivo bioassay for human gene therapy trials of Leber congenital amaurosis.

    Science.gov (United States)

    Roman, Alejandro J; Boye, Sanford L; Aleman, Tomas S; Pang, Ji-jing; McDowell, J Hugh; Boye, Shannon E; Cideciyan, Artur V; Jacobson, Samuel G; Hauswirth, William W

    2007-09-18

    Dramatic restoration of retinal function has followed subretinal viral-mediated gene therapy in RPE65-deficient animal models of human Leber congenital amaurosis (LCA) caused by RPE65 mutations. Progress in early-phase clinical trials of RPE65-LCA prompted us to begin development of an in vivo bioassay of clinical grade vector stability for later-phase trials. Naturally-occurring Rpe65-mutant rd12 mice (2-4 mo of age) were studied with full-field electroretinograms (ERGs). Flash stimuli (range, -4.1 to 3.6 log scot-cd x s x m(-2)) were used to evoke ERGs in anesthetized, dark-adapted mice. B-wave amplitudes were measured conventionally and luminance-response functions were fit. Leading edges of photoresponses were analyzed with a model of rod phototransduction activation. A unilateral subretinal injection of AAV2-CB(SB)-hRPE65 vector was delivered and therapeutic efficacy of 4 doses spanning a 2 log unit range was studied with ERGs performed about 6 weeks after injection. Uninjected rd12 eyes and wild-type (wt) mice served as controls. Rd12 mice showed substantially smaller amplitudes and lower sensitivities than wt mice for all measured ERG b-wave and photoresponse parameters. For the dose-response study, there was no difference between 0.01X-dosed mice and untreated mutants. Improved receptoral and post-receptoral function was evident for 0.1X, 0.3X, 1X doses: b-wave semi-saturation constants decreased, b-wave amplitudes increased with dose; photoresponses showed faster kinetics and higher maximum amplitudes. ERG b-wave amplitude to a selected stimulus light intensity could provide evidence of biologic activity of the vector; interocular differences in b-wave amplitude comparing treated versus untreated eyes in the same animal also revealed vector efficacy. We have taken the first steps toward developing an ERG assay of biologic activity of human grade vector for future clinical trials of RPE65-LCA. Faithful murine models of treatable human disease tested with

  2. Different human copper-zinc superoxide dismutase mutants, SOD1G93A and SOD1H46R, exert distinct harmful effects on gross phenotype in mice.

    Directory of Open Access Journals (Sweden)

    Lei Pan

    Full Text Available Amyotrophic lateral sclerosis (ALS is a heterogeneous group of fatal neurodegenerative diseases characterized by a selective loss of motor neurons in the brain and spinal cord. Creation of transgenic mice expressing mutant Cu/Zn superoxide dismutase (SOD1, as ALS models, has made an enormous impact on progress of the ALS studies. Recently, it has been recognized that genetic background and gender affect many physiological and pathological phenotypes. However, no systematic studies focusing on such effects using ALS models other than SOD1(G93A mice have been conducted. To clarify the effects of genetic background and gender on gross phenotypes among different ALS models, we here conducted a comparative analysis of growth curves and lifespans using congenic lines of SOD1(G93A and SOD1(H46R mice on two different genetic backgrounds; C57BL/6N (B6 and FVB/N (FVB. Copy number of the transgene and their expression between SOD1(G93A and SOD1(H46R lines were comparable. B6 congenic mutant SOD1 transgenic lines irrespective of their mutation and gender differences lived longer than corresponding FVB lines. Notably, the G93A mutation caused severer disease phenotypes than did the H46R mutation, where SOD1(G93A mice, particularly on a FVB background, showed more extensive body weight loss and earlier death. Gender effect on survival also solely emerged in FVB congenic SOD1(G93A mice. Conversely, consistent with our previous study using B6 lines, lack of Als2, a murine homolog for the recessive juvenile ALS causative gene, in FVB congenic SOD1(H46R, but not SOD1(G93A, mice resulted in an earlier death, implying a genetic background-independent but mutation-dependent phenotypic modification. These results indicate that SOD1(G93A- and SOD1(H46R-mediated toxicity and their associated pathogenic pathways are not identical. Further, distinctive injurious effects resulted from different SOD1 mutations, which are associated with genetic background and/or gender

  3. Interview : Sandra Bessudo Lion (APC-Colombia)

    OpenAIRE

    Bessudo Lion, Sandra

    2013-01-01

    She is a Marine Biologist, graduated from the Ecole Pratique de Hautes Etudes (EPHE), and holds a Master’s in Life and Earth Sciences from Perpignan, France. She is a professional scuba diver with over 5,000 dives in open waters. Ms. Bessudo is a professional strongly committed to the conservation of marine biodiversity and the protection of the environment. In January 2012, she took office as head of the General Directorate, Presidential Agency of International Cooperation, Colombia (APC-Col...

  4. Article Processing Charges and OpenAPC

    CERN Document Server

    CERN. Geneva

    2017-01-01

    The publication landscape is about to change. While being largely operated by subscription based journals in the past, recent political decisions force the publishing industry towards OpenAccess. Especially, the publication of the Finch report in 2012 put APC based Gold OpenAccess models almost everywhere on the agenda. These models also require quite some adoptions for library work flows to handle payments, bills and centralized funds for publication fees. Sometimes handled in specialized systems (e.g. first setups in Jülich) pretty early on discussions started to handle APCs in local repositories which would also hold the OpenAccess content resulting from these fees, e.g. the University of Regenburg uses ePrints for this purpose. Backed up by the OpenData movmement, libraries also saw opportunity to exchange data about fees payed. Thus, OpenAPC.de was born in 2014 on github to facilitate this exchange and aggregate large amounts of data for evaluation and comparison. Using the repository to hold payment d...

  5. CD8 Knockout Mice Are Protected from Challenge by Vaccination with WR201, a Live Attenuated Mutant of Brucella melitensis

    Directory of Open Access Journals (Sweden)

    Samuel L. Yingst

    2013-01-01

    Full Text Available CD8+ T cells have been reported to play an important role in defense against B. abortus infection in mouse models. In the present report, we use CD8 knockout mice to further elucidate the role of these cells in protection from B. melitensis infection. Mice were immunized orally by administration of B. melitensis WR201, a purine auxotrophic attenuated vaccine strain, then challenged intranasally with B. melitensis 16M. In some experiments, persistence of WR201 in the spleens of CD8 knockout mice was slightly longer than that in the spleens of normal mice. However, development of anti-LPS serum antibody, antigen-induced production of γ-interferon (IFN-γ by immune splenic lymphocytes, protection against intranasal challenge, and recovery of nonimmunized animals from intranasal challenge were similar between normal and knockout animals. Further, primary Brucella infection was not exacerbated in perforin knockout and Fas-deficient mice and these animals’ anti-Brucella immune responses were indistinguishable from those of normal mice. These results indicate that CD8+ T cells do not play an essential role as either cytotoxic cells or IFN-γ producers, yet they do participate in a specific immune response to immunization and challenge in this murine model of B. melitensis infection.

  6. Period2 gene mutant mice show compromised insulin-mediated endothelial nitric oxide release and altered glucose homeostasis

    Directory of Open Access Journals (Sweden)

    João Miguel Carvas

    2012-08-01

    Full Text Available Period2 (Per2 is an important component of the circadian clock. Mutation of this gene is associated with vascular endothelial dysfunction and altered glucose metabolism. The aim of this study is to further characterize whole body glucose homeostasis and endothelial NO production in response to insulin in the mPer2Brdm1 mice. We show that mPer2Brdm1 mice exhibit compromised insulin receptor activation and Akt signaling in various tissues including liver, fat, heart, and aortas with a tissue-specific heterogeneous diurnal pattern, and decreased insulin-stimulated endothelial NO release in the aortas in both active and inactive phases of the animals. As compared to wild type mice, the mPer2Brdm1 mice reveal hyperinsulinemia, hypoglycemia with lower fasting hepatic glycogen content and glycogen synthase level, no difference in glucose tolerance and insulin tolerance. The mPer2Brdm1 mice do not show increased predisposition to obesity either on normal chow or high fat diet compared to wild type controls. Thus, mice with Per2 gene mutation show altered glucose homeostasis and compromised insulin-stimulated endothelial NO release, independently of obesity.

  7. Evidence that the spindle assembly checkpoint does not regulate APC(Fzy) activity in Drosophila female meiosis.

    Science.gov (United States)

    Batiha, Osamah; Swan, Andrew

    2012-01-01

    The spindle assembly checkpoint (SAC) plays an important role in mitotic cells to sense improper chromosome attachment to spindle microtubules and to inhibit APC(Fzy)-dependent destruction of cyclin B and Securin; consequent initiation of anaphase until correct attachments are made. In Drosophila , SAC genes have been found to play a role in ensuring proper chromosome segregation in meiosis, possibly reflecting a similar role for the SAC in APC(Fzy) inhibition during meiosis. We found that loss of function mutations in SAC genes, Mad2, zwilch, and mps1, do not lead to the predicted rise in APC(Fzy)-dependent degradation of cyclin B either globally throughout the egg or locally on the meiotic spindle. Further, the SAC is not responsible for the inability of APC(Fzy) to target cyclin B and promote anaphase in metaphase II arrested eggs from cort mutant females. Our findings support the argument that SAC proteins play checkpoint independent roles in Drosophila female meiosis and that other mechanisms must function to control APC activity.

  8. Molecular mechanism of APC/C activation by mitotic phosphorylation.

    Science.gov (United States)

    Zhang, Suyang; Chang, Leifu; Alfieri, Claudio; Zhang, Ziguo; Yang, Jing; Maslen, Sarah; Skehel, Mark; Barford, David

    2016-05-12

    In eukaryotes, the anaphase-promoting complex (APC/C, also known as the cyclosome) regulates the ubiquitin-dependent proteolysis of specific cell-cycle proteins to coordinate chromosome segregation in mitosis and entry into the G1 phase. The catalytic activity of the APC/C and its ability to specify the destruction of particular proteins at different phases of the cell cycle are controlled by its interaction with two structurally related coactivator subunits, Cdc20 and Cdh1. Coactivators recognize substrate degrons, and enhance the affinity of the APC/C for its cognate E2 (refs 4-6). During mitosis, cyclin-dependent kinase (Cdk) and polo-like kinase (Plk) control Cdc20- and Cdh1-mediated activation of the APC/C. Hyperphosphorylation of APC/C subunits, notably Apc1 and Apc3, is required for Cdc20 to activate the APC/C, whereas phosphorylation of Cdh1 prevents its association with the APC/C. Since both coactivators associate with the APC/C through their common C-box and Ile-Arg tail motifs, the mechanism underlying this differential regulation is unclear, as is the role of specific APC/C phosphorylation sites. Here, using cryo-electron microscopy and biochemical analysis, we define the molecular basis of how phosphorylation of human APC/C allows for its control by Cdc20. An auto-inhibitory segment of Apc1 acts as a molecular switch that in apo unphosphorylated APC/C interacts with the C-box binding site and obstructs engagement of Cdc20. Phosphorylation of the auto-inhibitory segment displaces it from the C-box-binding site. Efficient phosphorylation of the auto-inhibitory segment, and thus relief of auto-inhibition, requires the recruitment of Cdk-cyclin in complex with a Cdk regulatory subunit (Cks) to a hyperphosphorylated loop of Apc3. We also find that the small-molecule inhibitor, tosyl-l-arginine methyl ester, preferentially suppresses APC/C(Cdc20) rather than APC/C(Cdh1), and interacts with the binding sites of both the C-box and Ile-Arg tail motifs. Our

  9. Liver tumor formation by a mutant retinoblastoma protein in the transgenic mice is caused by an upregulation of c-Myc target genes

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Bo; Hikosaka, Keisuke; Sultana, Nishat; Sharkar, Mohammad Tofael Kabir [Department of Biochemistry, Hamamatsu University School of Medicine, 1-20-1 Handa-yama, Higashi-ku, Hamamatsu 431-3192 (Japan); Noritake, Hidenao [Department of Biochemistry, Hamamatsu University School of Medicine, 1-20-1 Handa-yama, Higashi-ku, Hamamatsu 431-3192 (Japan); Department of Internal Medicine, Hamamatsu University School of Medicine, 1-20-1 Handa-yama, Higashi-ku, Hamamatsu 431-3192 (Japan); Kimura, Wataru; Wu, Yi-Xin [Department of Biochemistry, Hamamatsu University School of Medicine, 1-20-1 Handa-yama, Higashi-ku, Hamamatsu 431-3192 (Japan); Kobayashi, Yoshimasa [Department of Internal Medicine, Hamamatsu University School of Medicine, 1-20-1 Handa-yama, Higashi-ku, Hamamatsu 431-3192 (Japan); Uezato, Tadayoshi [Department of Biochemistry, Hamamatsu University School of Medicine, 1-20-1 Handa-yama, Higashi-ku, Hamamatsu 431-3192 (Japan); Miura, Naoyuki, E-mail: nmiura@hama-med.ac.jp [Department of Biochemistry, Hamamatsu University School of Medicine, 1-20-1 Handa-yama, Higashi-ku, Hamamatsu 431-3192 (Japan)

    2012-01-06

    Highlights: Black-Right-Pointing-Pointer Fifty percent of the mutant Rb transgenic mice produced liver tumors. Black-Right-Pointing-Pointer In the tumor, Foxm1, Skp2, Bmi1 and AP-1 mRNAs were up-regulated. Black-Right-Pointing-Pointer No increase in expression of the Myc-target genes was observed in the non-tumorous liver. Black-Right-Pointing-Pointer Tumor formation depends on up-regulation of the Myc-target genes. -- Abstract: The retinoblastoma (Rb) tumor suppressor encodes a nuclear phosphoprotein that regulates cellular proliferation, apoptosis and differentiation. In order to adapt itself to these biological functions, Rb is subjected to modification cycle, phosphorylation and dephosphorylation. To directly determine the effect of phosphorylation-resistant Rb on liver development and function, we generated transgenic mice expressing phosphorylation-resistant human mutant Rb (mt-Rb) under the control of the rat hepatocyte nuclear factor-1 gene promoter/enhancer. Expression of mt-Rb in the liver resulted in macroscopic neoplastic nodules (adenomas) with {approx}50% incidence within 15 months old. Interestingly, quantitative reverse transcriptase-PCR analysis showed that c-Myc was up-regulated in the liver of mt-Rb transgenic mice irrespective of having tumor tissues or no tumor. In tumor tissues, several c-Myc target genes, Foxm1, c-Jun, c-Fos, Bmi1 and Skp2, were also up-regulated dramatically. We determined whether mt-Rb activated the Myc promoter in the HTP9 cells and demonstrated that mt-Rb acted as an inhibitor of wild-type Rb-induced repression on the Myc promoter. Our results suggest that continued upregulation of c-Myc target genes promotes the liver tumor formation after about 1 year of age.

  10. SMC6 is an essential gene in mice, but a hypomorphic mutant in the ATPase domain has a mild phenotype with a range of subtle abnormalities.

    Science.gov (United States)

    Ju, Limei; Wing, Jonathan; Taylor, Elaine; Brandt, Renata; Slijepcevic, Predrag; Horsch, Marion; Rathkolb, Birgit; Rácz, Ildikó; Becker, Lore; Hans, Wolfgang; Adler, Thure; Beckers, Johannes; Rozman, Jan; Klingenspor, Martin; Wolf, Eckhard; Zimmer, Andreas; Klopstock, Thomas; Busch, Dirk H; Gailus-Durner, Valérie; Fuchs, Helmut; de Angelis, Martin Hrabě; van der Horst, Gilbertus; Lehmann, Alan R

    2013-05-01

    Smc5-6 is a highly conserved protein complex related to cohesin and condensin involved in the structural maintenance of chromosomes. In yeasts the Smc5-6 complex is essential for proliferation and is involved in DNA repair and homologous recombination. siRNA depletion of genes involved in the Smc5-6 complex in cultured mammalian cells results in sensitivity to some DNA damaging agents. In order to gain further insight into its role in mammals we have generated mice mutated in the Smc6 gene. A complete knockout resulted in early embryonic lethality, demonstrating that this gene is essential in mammals. However, mutation of the highly conserved serine-994 to alanine in the ATP hydrolysis motif in the SMC6 C-terminal domain, resulted in mice with a surprisingly mild phenotype. With the neo gene selection marker in the intron following the mutation, resulting in reduced expression of the SMC6 gene, the mice were reduced in size, but fertile and had normal lifespans. When the neo gene was removed, the mice had normal size, but detailed phenotypic analysis revealed minor abnormalities in glucose tolerance, haematopoiesis, nociception and global gene expression patterns. Embryonic fibroblasts derived from the ser994 mutant mice were not sensitive to killing by a range of DNA damaging agents, but they were sensitive to the induction of sister chromatid exchanges induced by ultraviolet light or mitomycin C. They also accumulated more oxidative damage than wild-type cells. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Relationship between UV-induced mutant p53 patches and skin tumours, analysed by mutation spectra and by induction kinetics in various DNA-repair-deficient mice.

    Science.gov (United States)

    Rebel, Heggert; Kram, Nicolien; Westerman, Anja; Banus, Sander; van Kranen, Henk J; de Gruijl, Frank R

    2005-12-01

    Clusters of p53 immunopositive epidermal keratinocytes (so-called p53 patches, clones or foci) are found in sun or ultraviolet (UV) light-exposed skin. We investigated to what extent these p53 patches are genuine precursors of skin carcinomas in chronically irradiated hairless (SKH1) mice. The mutation spectra of exons 5-8 of the p53 gene of laser-micro-dissected mutant p53 patches and carcinomas were therefore compared. The mutations we found were mainly UV-signature mutations (C-->T and CC-->TT at dipyrimidine sites) located at known hotspots. No significant differences were found between both spectra, indicating that all p53 patches harbour mutations with which they could progress to carcinomas. To examine whether these p53 patches can be used as tumour risk indicators, we made an extensive comparison of the induction kinetics of these patches and carcinomas in genetically modified mice with various defects in nucleotide excision repair (NER), i.e. xeroderma pigmentosum A (Xpa), Xpc and Cockayne syndrome B (Csb) and wild-type mice. In this aforementioned order, the mouse strains developed both p53 patches and carcinomas in the course of daily exposure to 40 J/m(2) UV. Hence, the order in which the NER-deficient mice developed patches was predictive of the order in which they developed tumours. The induction kinetics of the patches in Xpc-deficient mice differed notably from the others: there was a stationary phase (days 13-41) where the numbers were limited to 5-10 patches per mouse before an explosive increase which ran parallel to the other groups. The chance that a p53 patch progresses to carcinoma is relatively small (estimated at 1 out of 8300-40,000/individual when the first tumour appears), but our results are strongly indicative of a causal relationship between p53 patches and carcinomas.

  12. Ex-vivo assessment and non-invasive in vivo imaging of internal hemorrhages in Aga2/+ mutant mice

    Energy Technology Data Exchange (ETDEWEB)

    Ermolayev, Vladimir [Institute for Biological and Medical Imaging, Helmholtz Zentrum München, Building 56, Ingolstädter Landstraße 1, D-85764 Neuherberg (Germany); Cohrs, Christian M. [Institute for Experimental Genetics, Helmholtz Zentrum München, Ingolstädter Landstraße 1, D-85764 Neuherberg (Germany); Mohajerani, Pouyan; Ale, Angelique [Institute for Biological and Medical Imaging, Helmholtz Zentrum München, Building 56, Ingolstädter Landstraße 1, D-85764 Neuherberg (Germany); Hrabé de Angelis, Martin [Institute for Experimental Genetics, Helmholtz Zentrum München, Ingolstädter Landstraße 1, D-85764 Neuherberg (Germany); Ntziachristos, Vasilis, E-mail: v.ntziachristos@tum.de [Institute for Biological and Medical Imaging, Helmholtz Zentrum München, Building 56, Ingolstädter Landstraße 1, D-85764 Neuherberg (Germany)

    2013-03-08

    Highlights: ► Aga2/+ mice, model for Osteogenesis imperfecta, have type I collagen mutation. ► Aga2/+ mice display both moderate and severe phenotypes lethal 6–11th postnatal. ► Internal hemorrhages studied in Aga2/+ vs. control mice at 6 and 9 days postnatal. ► Anatomical and functional findings in-vivo contrasted to the ex-vivo appearance. -- Abstract: Mutations in type I collagen genes (COL1A1/2) typically lead to Osteogenesis imperfecta, the most common heritable cause of skeletal fractures and bone deformation in humans. Heterozygous Col1a1{sup Aga2/+}, animals with a dominant mutation in the terminal C-propeptide domain of type I collagen develop typical skeletal hallmarks and internal hemorrhages starting from 6 day after birth. The disease progression for Aga2/+ mice, however, is not uniform differing between severe phenotype lethal at the 6–11th day of life, and moderate-to-severe one with survival to adulthood. Herein we investigated whether a new modality that combines X-ray computer tomography with fluorescence tomography in one hybrid system can be employed to study internal bleedings in relation to bone fractures and obtain insights into disease progression. The disease phenotype was characterized on Aga2/+ vs. wild type mice between 6 and 9 days postnatal. Anatomical and functional findings obtained in-vivo were contrasted to the ex-vivo appearance of the same tissues under cryo-slicing.

  13. Stem cell expansion during carcinogenesis in stem cell-depleted conditional telomeric repeat factor 2 null mutant mice.

    Science.gov (United States)

    Bojovic, B; Ho, H-Y; Wu, J; Crowe, D L

    2013-10-24

    To examine the role of telomeric repeat-binding factor 2 (TRF2) in epithelial tumorigenesis, we characterized conditional loss of TRF2 expression in the basal layer of mouse epidermis. These mice exhibit some characteristics of dyskeratosis congenita, a human stem cell depletion syndrome caused by telomere dysfunction. The epidermis in conditional TRF2 null mice exhibited DNA damage response and apoptosis, which correlated with stem cell depletion. The stem cell population in conditional TRF2 null epidermis exhibited shorter telomeres than those in control mice. Squamous cell carcinomas induced in conditional TRF2 null mice developed with increased latency and slower growth due to reduced numbers of proliferating cells as the result of increased apoptosis. TRF2 null epidermal stem cells were found in both primary and metastatic tumors. Despite the low-grade phenotype of the conditional TRF2 null primary tumors, the number of metastatic lesions was similar to control cancers. Basal cells from TRF2 null tumors demonstrated extreme telomere shortening and dramatically increased numbers of telomeric signals by fluorescence in situ hybridization due to increased genomic instability and aneuploidy in these cancers. DNA damage response signals were detected at telomeres in TRF2 null tumor cells from these mice. The increased genomic instability in these tumors correlated with eightfold expansion of the transformed stem cell population compared with that in control cancers. We concluded that genomic instability resulting from loss of TRF2 expression provides biological advantages to the cancer stem cell population.

  14. Distinct synaptic and neurochemical changes to the granule cell-CA3 projection in Bassoon mutant mice

    OpenAIRE

    Dieni, Sandra; Nestel, Sigrun; Sibbe, Mirjam; Frotscher, Michael; Hellwig, Sabine

    2015-01-01

    Proper synaptic function depends on a finely-tuned balance between events such as protein synthesis and structural organization. In particular, the functional loss of just one synaptic-related protein can have a profound impact on overall neuronal network function. To this end, we used a mutant mouse model harboring a mutated form of the presynaptic scaffolding protein Bassoon (Bsn), which is phenotypically characterized by: (i) spontaneous generalized epileptic seizure activity, representing...

  15. [Inhibition Function of Dominant-negative Mutant Gene Survivin-D53A to SPC-A1 Lung Adenocarcinoma Xenograft in Nude Mice Models].

    Science.gov (United States)

    Yu, Min; Peng, Xingchen; Lu, You; Huang, Meijuan

    2015-06-01

    Survivin-D53A (SVV-D53A) is a dominant-negative mutant survivin, which represents a potential promising target for cancer gene therapy. The present study was designed to determine whether SVV-D53A plasmid encapsuled by DOTAP: Chol liposome would have the anti-tumor activity against SPC-A1 lung adenocarcinoma, and to detect the possible mechanisms. In our experiment, SPC-A1 cells were transfected in vitro with SVV-D53A plasmid and examined for protein expression by Western blot, then flow cytometric analysis was used to detect apoptosis. SPC-A1 lung adenocarcinoma xenografts were established in vivo in the nude mice, which received the i. v. administrations of SVV-D53A plasmid/liposome complexes. After mice were sacrificed, the paraffin-embedded tumor tissue sections were used for proliferating cell nuclear antigen (PCNA) expression and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Compared with the control group, the mice treated with SVV-D53A plasmid had an obviously reduced tumor volume, with high level of apoptosis and decreased cell proliferation in tumor tissue. The research results proved that the administration of SVV-D53A plasmid resulted in significant inhibition of SPC-A1 cells both in vitro and in vivo. The functional mechanism is that the anti-tumor response causes and induces tumor cell apoptosis.

  16. Action potential generation in the small intestine of W mutant mice that lack interstitial cells of Cajal

    DEFF Research Database (Denmark)

    Malysz, J; Thuneberg, L; Mikkelsen, Hanne Birte

    1996-01-01

    The small intestine of W/Wv mice lacks both the network of interstitial cells of Cajal (ICC), associated with Auerbach's plexus, and pacemaker activity, i.e., it does not generate slow-wave-type action potentials. The W/Wv muscle preparations showed a wide variety of electrical activities, rangin...

  17. Role of RANKL (TNFSF11-dependent osteopetrosis in the dental phenotype of Msx2 null mutant mice.

    Directory of Open Access Journals (Sweden)

    Beatriz Castaneda

    Full Text Available The MSX2 homeoprotein is implicated in all aspects of craniofacial skeletal development. During postnatal growth, MSX2 is expressed in all cells involved in mineralized tissue formation and plays a role in their differentiation and function. Msx2 null (Msx2 (-/- mice display complex craniofacial skeleton abnormalities with bone and tooth defects. A moderate form osteopetrotic phenotype is observed, along with decreased expression of RANKL (TNFSF11, the main osteoclast-differentiating factor. In order to elucidate the role of such an osteopetrosis in the Msx2 (-/- mouse dental phenotype, a bone resorption rescue was performed by mating Msx2 (-/- mice with a transgenic mouse line overexpressing Rank (Tnfrsf11a. Msx2 (-/- Rank(Tg mice had significant improvement in the molar phenotype, while incisor epithelium defects were exacerbated in the enamel area, with formation of massive osteolytic tumors. Although compensation for RANKL loss of function could have potential as a therapy for osteopetrosis, but in Msx2 (-/- mice, this approach via RANK overexpression in monocyte-derived lineages, amplified latent epithelial tumor development in the peculiar continuously growing incisor.

  18. Shank3-mutant mice lacking exon 9 show altered excitation/inhibition balance, enhanced rearing, and spatial memory deficit

    Directory of Open Access Journals (Sweden)

    Jiseok eLee

    2015-03-01

    Full Text Available Shank3 is a postsynaptic scaffolding protein implicated in synapse development and autism spectrum disorders. The Shank3 gene is known to produce diverse splice variants whose functions have not been fully explored. In the present study, we generated mice lacking Shank3 exon 9 (Shank3∆9 mice, and thus missing 5 out of 10 known Shank3 splice variants containing the N-terminal ankyrin repeat region, including the longest splice variant, Shank3a. Our X-gal staining results revealed that Shank3 proteins encoded by exon 9-containing splice variants are abundant in upper cortical layers, striatum, hippocampus, and thalamus, but not in the olfactory bulb or cerebellum, despite the significant Shank3 mRNA levels in these regions. The hippocampal CA1 region of Shank3∆9 mice exhibited reduced excitatory transmission at Schaffer collateral synapses and increased frequency of spontaneous inhibitory synaptic events in pyramidal neurons. In contrast, prelimbic layer 2/3 pyramidal neurons in the medial prefrontal cortex displayed decreased frequency of spontaneous inhibitory synaptic events, indicating alterations in the ratio of excitation/inhibition (E/I ratio in the Shank3∆9 brain. These mice displayed a mild increase in rearing in a novel environment and mildly impaired spatial memory, but showed normal social interaction and repetitive behavior. These results suggest that ankyrin repeat-containing Shank3 splice variants are important for E/I balance, rearing behavior, and spatial memory.

  19. Booster vaccination with safe, modified, live-attenuated mutants of Brucella abortus strain RB51 vaccine confers protective immunity against virulent strains of B. abortus and Brucella canis in BALB/c mice.

    Science.gov (United States)

    Truong, Quang Lam; Cho, Youngjae; Kim, Kiju; Park, Bo-Kyoung; Hahn, Tae-Wook

    2015-11-01

    Brucella abortus attenuated strain RB51 vaccine (RB51) is widely used in prevention of bovine brucellosis. Although vaccination with this strain has been shown to be effective in conferring protection against bovine brucellosis, RB51 has several drawbacks, including residual virulence for animals and humans. Therefore, a safe and efficacious vaccine is needed to overcome these disadvantages. In this study, we constructed several gene deletion mutants (ΔcydC, ΔcydD and ΔpurD single mutants, and ΔcydCΔcydD and ΔcydCΔpurD double mutants) of RB51 with the aim of increasing the safety of the possible use of these mutants as vaccine candidates. The RB51ΔcydC, RB51ΔcydD, RB51ΔpurD, RB51ΔcydCΔcydD and RB51ΔcydCΔpurD mutants exhibited significant attenuation of virulence when assayed in murine macrophages in vitro or in BALB/c mice. A single intraperitoneal immunization with RB51ΔcydC, RB51ΔcydD, RB51ΔcydCΔcydD or RB51ΔcydCΔpurD mutants was rapidly cleared from mice within 3 weeks, whereas the RB51ΔpurD mutant and RB51 were detectable in spleens until 4 and 7 weeks, respectively. Vaccination with a single dose of RB51 mutants induced lower protective immunity in mice than did parental RB51. However, a booster dose of these mutants provided significant levels of protection in mice against challenge with either the virulent homologous B. abortus strain 2308 or the heterologous Brucella canis strain 26. In addition, these mutants were found to induce a mixed but T-helper-1-biased humoral and cellular immune response in immunized mice. These data suggest that immunization with a booster dose of attenuated RB51 mutants provides an attractive strategy to protect against either bovine or canine brucellosis.

  20. Oxidative damage in brain from human mutant APP/PS-1 double knock-in mice as a function of age.

    Science.gov (United States)

    Abdul, Hafiz Mohmmad; Sultana, Rukhsana; St Clair, Daret K; Markesbery, William R; Butterfield, D Allan

    2008-11-15

    Oxidative stress is strongly implicated in the progressive decline of cognition associated with aging and neurodegenerative disorders. In the brain, free radical-mediated oxidative stress plays a critical role in the age-related decline of cellular function as a result of the oxidation of proteins, lipids, and nucleic acids. A number of studies indicate that an increase in protein oxidation and lipid peroxidation is associated with age-related neurodegenerative diseases and cellular dysfunction observed in aging brains. Oxidative stress is one of the important factors contributing to Alzheimer's disease (AD), one of whose major hallmarks includes brain depositions of amyloid beta-peptide (Abeta) derived from amyloid precursor protein (APP). Mutation in APP and PS-1 genes, which increases production of the highly amyloidogenic amyloid beta-peptide (Abeta42), is the major cause of familial AD. In the present study, protein oxidation and lipid peroxidation in the brain from knock-in mice expressing human mutant APP and PS-1 were compared with brain from wild type, as a function of age. The results suggest that there is an increased oxidative stress in the brain of wild-type mice as a function of age. In APP/PS-1 mouse brain, there is a basal increase (at 1 month) in oxidative stress compared to the wild type (1 month), as measured by protein oxidation and lipid peroxidation. In addition, age-related elevation of oxidative damage was observed in APP/PS-1 mice brain compared to that of wild-type mice brain. These results are discussed with reference to the importance of Abeta42-associated oxidative stress in the pathogenesis of AD.

  1. Calcilytic Ameliorates Abnormalities of Mutant Calcium-Sensing Receptor (CaSR) Knock-In Mice Mimicking Autosomal Dominant Hypocalcemia (ADH).

    Science.gov (United States)

    Dong, Bingzi; Endo, Itsuro; Ohnishi, Yukiyo; Kondo, Takeshi; Hasegawa, Tomoka; Amizuka, Norio; Kiyonari, Hiroshi; Shioi, Go; Abe, Masahiro; Fukumoto, Seiji; Matsumoto, Toshio

    2015-11-01

    Activating mutations of calcium-sensing receptor (CaSR) cause autosomal dominant hypocalcemia (ADH). ADH patients develop hypocalcemia, hyperphosphatemia, and hypercalciuria, similar to the clinical features of hypoparathyroidism. The current treatment of ADH is similar to the other forms of hypoparathyroidism, using active vitamin D3 or parathyroid hormone (PTH). However, these treatments aggravate hypercalciuria and renal calcification. Thus, new therapeutic strategies for ADH are needed. Calcilytics are allosteric antagonists of CaSR, and may be effective for the treatment of ADH caused by activating mutations of CaSR. In order to examine the effect of calcilytic JTT-305/MK-5442 on CaSR harboring activating mutations in the extracellular and transmembrane domains in vitro, we first transfected a mutated CaSR gene into HEK cells. JTT-305/MK-5442 suppressed the hypersensitivity to extracellular Ca(2+) of HEK cells transfected with the CaSR gene with activating mutations in the extracellular and transmembrane domains. We then selected two activating mutations locating in the extracellular (C129S) and transmembrane (A843E) domains, and generated two strains of CaSR knock-in mice to build an ADH mouse model. Both mutant mice mimicked almost all the clinical features of human ADH. JTT-305/MK-5442 treatment in vivo increased urinary cAMP excretion, improved serum and urinary calcium and phosphate levels by stimulating endogenous PTH secretion, and prevented renal calcification. In contrast, PTH(1-34) treatment normalized serum calcium and phosphate but could not reduce hypercalciuria or renal calcification. CaSR knock-in mice exhibited low bone turnover due to the deficiency of PTH, and JTT-305/MK-5442 as well as PTH(1-34) increased bone turnover and bone mineral density (BMD) in these mice. These results demonstrate that calcilytics can reverse almost all the phenotypes of ADH including hypercalciuria and renal calcification, and suggest that calcilytics can become a

  2. Intestinal APCs of the endogenous nanomineral pathway fail to express PD-L1 in Crohn's disease.

    Science.gov (United States)

    Robertson, Jack; Haas, Carolin T; Pele, Laetitia C; Monie, Tom P; Charalambos, Charles; Parkes, Miles; Hewitt, Rachel E; Powell, Jonathan J

    2016-05-26

    Crohn's disease is a chronic inflammatory condition most commonly affecting the ileum and colon. The aetiology of Crohn's disease is complex and may include defects in peptidoglycan recognition, and/or failures in the establishment of intestinal tolerance. We have recently described a novel constitutive endogenous delivery system for the translocation of nanomineral-antigen-peptidoglycan (NAP) conjugates to antigen presenting cells (APCs) in intestinal lymphoid patches. In mice NAP conjugate delivery to APCs results in high surface expression of the immuno-modulatory molecule programmed death receptor ligand 1 (PD-L1). Here we report that NAP conjugate positive APCs in human ileal tissues from individuals with ulcerative colitis and intestinal carcinomas, also have high expression of PD-L1. However, NAP-conjugate positive APCs in intestinal tissue from patients with Crohn's disease show selective failure in PD-L1 expression. Therefore, in Crohn's disease intestinal antigen taken up by lymphoid patch APCs will be presented without PD-L1 induced tolerogenic signalling, perhaps initiating disease.

  3. Entrevista : Sandra Bessudo Lion (APC-Colombia)

    OpenAIRE

    2013-01-01

    Bióloga Marina del Ecole Pratique de Hautes Etudes Ephe, con Máster en Estudios de Ciencias de la Vida y de la Tierra en Perpignan, Francia. Es buzo profesional con más de 5.000 inmersiones en aguas abiertas, siendo una profesional muy comprometida con la conservación de la biodiversidad marina y con el cuidado del medio ambiente. A partir de enero de 2012 asumió la Dirección General de la Agencia Presidencial de Cooperación Internacional de Colombia (APC-Colombia), entidad gubernamental enca...

  4. Distinct synaptic and neurochemical changes to the granule cell-CA3 projection in Bassoon mutant mice.

    Directory of Open Access Journals (Sweden)

    Sandra eDieni

    2015-10-01

    Full Text Available Proper synaptic function depends on a finely-tuned balance between events such as protein synthesis and structural organization. In particular, the functional loss of just one synaptic-related protein can have a profound impact on overall neuronal network function. To this end, we used a mutant mouse model harboring a mutated form of the presynaptic scaffolding protein Bassoon (Bsn, which is phenotypically characterized by: (i spontaneous generalized epileptic seizure activity, representing a chronically-imbalanced neuronal network, and (ii a dramatic increase in hippocampal brain-derived neurotrophic factor (BDNF protein concentration, a key player in synaptic plasticity. Detailed morphological and neurochemical analyses revealed that the increased BDNF levels are associated with: I. modified neuropeptide distribution, II. perturbed expression of selected markers of synaptic activation or plasticity, III. subtle changes to microglial structure, and IV. morphological alterations to the mossy fiber synapse. These findings emphasize the important contribution of Bassoon protein to normal hippocampal function, and further characterize the Bsn mutant as a useful model for studying the effects of chronic changes to network activity.

  5. Dasatinib targets B-lineage cells but does not provide an effective therapy for myeloproliferative disease in c-Cbl RING finger mutant mice.

    Directory of Open Access Journals (Sweden)

    Johanna M Duyvestyn

    Full Text Available This study aimed to determine whether the multi-kinase inhibitor dasatinib would provide an effective therapy for myeloproliferative diseases (MPDs involving c-Cbl mutations. These mutations, which occur in the RING finger and linker domains, abolish the ability of c-Cbl to function as an E3 ubiquitin ligase and downregulate activated protein tyrosine kinases. Here we analyzed the effects of dasatinib in a c-Cbl RING finger mutant mouse that develops an MPD with a phenotype similar to the human MPDs. The mice are characterized by enhanced tyrosine kinase signaling resulting in an expansion of hematopoietic stem cells, multipotent progenitors and cells within the myeloid lineage. Since c-Cbl is a negative regulator of c-Kit and Src signaling we reasoned that dasatinib, which targets these kinases, would be an effective therapy. Furthermore, two recent studies showed dasatinib to be effective in inhibiting the in vitro growth of cells from leukemia patients with c-Cbl RING finger and linker domain mutations. Surprisingly we found that dasatinib did not provide an effective therapy for c-Cbl RING finger mutant mice since it did not suppress any of the hematopoietic lineages that promote MPD development. Thus we conclude that dasatinib may not be an appropriate therapy for leukemia patients with c-Cbl mutations. We did however find that dasatinib caused a marked reduction of pre-B cells and immature B cells which correlated with a loss of Src activity. This study is therefore the first to provide a detailed characterization of in vivo effects of dasatinib in a hematopoietic disorder that is driven by protein tyrosine kinases other than BCR-ABL.

  6. Dasatinib Targets B-Lineage Cells but Does Not Provide an Effective Therapy for Myeloproliferative Disease in c-Cbl RING Finger Mutant Mice

    Science.gov (United States)

    Duyvestyn, Johanna M.; Taylor, Samuel J.; Dagger, Samantha A.; Orandle, Marlene; Morse, Herbert C.; Thien, Christine B. F.; Langdon, Wallace Y.

    2014-01-01

    This study aimed to determine whether the multi-kinase inhibitor dasatinib would provide an effective therapy for myeloproliferative diseases (MPDs) involving c-Cbl mutations. These mutations, which occur in the RING finger and linker domains, abolish the ability of c-Cbl to function as an E3 ubiquitin ligase and downregulate activated protein tyrosine kinases. Here we analyzed the effects of dasatinib in a c-Cbl RING finger mutant mouse that develops an MPD with a phenotype similar to the human MPDs. The mice are characterized by enhanced tyrosine kinase signaling resulting in an expansion of hematopoietic stem cells, multipotent progenitors and cells within the myeloid lineage. Since c-Cbl is a negative regulator of c-Kit and Src signaling we reasoned that dasatinib, which targets these kinases, would be an effective therapy. Furthermore, two recent studies showed dasatinib to be effective in inhibiting the in vitro growth of cells from leukemia patients with c-Cbl RING finger and linker domain mutations. Surprisingly we found that dasatinib did not provide an effective therapy for c-Cbl RING finger mutant mice since it did not suppress any of the hematopoietic lineages that promote MPD development. Thus we conclude that dasatinib may not be an appropriate therapy for leukemia patients with c-Cbl mutations. We did however find that dasatinib caused a marked reduction of pre-B cells and immature B cells which correlated with a loss of Src activity. This study is therefore the first to provide a detailed characterization of in vivo effects of dasatinib in a hematopoietic disorder that is driven by protein tyrosine kinases other than BCR-ABL. PMID:24718698

  7. Identification of the c-kit ligand: end of the road for understanding aplastic anemia in steel mutant mice?

    Science.gov (United States)

    Pantel, K; Boertman, J; Nakeff, A

    1991-09-15

    We here report the initiation of hematopoietic recovery in congenitally hypoplastic S1/S1d mice by the cytotoxic ablation of cells bearing the natural killer (NK) phenotype (NK 1.1+). The most striking finding was the early several-fold increase in the cycling fraction of stem and progenitor cells (with the exception of progenitors committed to megakaryocytopoiesis) in the anti-NK 1.1+ antibody-treated group. This increase resulted in an early, complete restoration of total marrow cellularity to the normal (+/+) littermate level. Our data suggest that NK 1.1+ cells exert functions critical to the negative control of hematopoietic cell proliferation in S1/S1d mice.

  8. Peripheral motor axons of SOD1(G127X) mutant mice are susceptible to activity-dependent degeneration

    DEFF Research Database (Denmark)

    Alvarez Herrero, Susana; Calin, A; Graffmo, K S

    2013-01-01

    Motor neuron disorders may be associated with mitochondrial dysfunction, and repetitive electrical impulse conduction during energy restriction has been found to cause neuronal degeneration. The aim of this study was to investigate the vulnerability of motor axons of a presymptomatic late......-onset, fast-progression SOD1(G127X) mouse model of amyotrophic lateral sclerosis to long-lasting, high-frequency repetitive activity. Tibial nerves were stimulated at ankle in 7 to 8-month-old SOD1(G127X) mice when they were clinically indistinguishable from wild-type (WT) mice. The evoked compound muscle...... action potentials and ascending compound nerve action potentials were recorded from plantar muscles and from the sciatic nerve, respectively. Repetitive stimulation (RS) was carried out in interrupted trains of 200-Hz for 3h. During the stimulation-sequence there was progressive conduction failure in WT...

  9. DNA adducts, mutant frequencies and mutation spectra in λlacZ transgenic mice treated with N-nitrosodimethylamine

    NARCIS (Netherlands)

    Souliotis, V.L.; Delft, J.H.M. van; Steenwinkel, M.-J.S.T.; Baan, R.A.; Kyrtopoulos, S.A.

    1998-01-01

    Groups of λlacZ transgenic mice were treated i.p. with N-nitrosodimethylamine (NDMA) as single doses of 5 mg/kg or 10 mg/kg or as 10 daily doses of 1 mg/kg and changes in DNA N7- or O6-methylguanine or the repair enzyme O6-alkylguanine-DNA alkyltransferase (AGT) were followed for up to 14 days in va

  10. DNA adducts, mutant frequencies and mutation spectra in λlacZ transgenic mice treated with N-nitrosodimethylamine

    NARCIS (Netherlands)

    Souliotis, V.L.; Delft, J.H.M. van; Steenwinkel, M.-J.S.T.; Baan, R.A.; Kyrtopoulos, S.A.

    1998-01-01

    Groups of λlacZ transgenic mice were treated i.p. with N-nitrosodimethylamine (NDMA) as single doses of 5 mg/kg or 10 mg/kg or as 10 daily doses of 1 mg/kg and changes in DNA N7- or O6-methylguanine or the repair enzyme O6-alkylguanine-DNA alkyltransferase (AGT) were followed for up to 14 days in

  11. Human selenoprotein P and S variant mRNAs with different numbers of SECIS elements and inferences from mutant mice of the roles of multiple SECIS elements.

    Science.gov (United States)

    Wu, Sen; Mariotti, Marco; Santesmasses, Didac; Hill, Kristina E; Baclaocos, Janinah; Aparicio-Prat, Estel; Li, Shuping; Mackrill, John; Wu, Yuanyuan; Howard, Michael T; Capecchi, Mario; Guigó, Roderic; Burk, Raymond F; Atkins, John F

    2016-11-01

    Dynamic redefinition of the 10 UGAs in human and mouse selenoprotein P (Sepp1) mRNAs to specify selenocysteine instead of termination involves two 3' UTR structural elements (SECIS) and is regulated by selenium availability. In addition to the previously known human Sepp1 mRNA poly(A) addition site just 3' of SECIS 2, two further sites were identified with one resulting in 10-25% of the mRNA lacking SECIS 2. To address function, mutant mice were generated with either SECIS 1 or SECIS 2 deleted or with the first UGA substituted with a serine codon. They were fed on either high or selenium-deficient diets. The mutants had very different effects on the proportions of shorter and longer product Sepp1 protein isoforms isolated from plasma, and on viability. Spatially and functionally distinctive effects of the two SECIS elements on UGA decoding were inferred. We also bioinformatically identify two selenoprotein S mRNAs with different 5' sequences predicted to yield products with different N-termini. These results provide insights into SECIS function and mRNA processing in selenoprotein isoform diversity.

  12. Analysis of APC allelic imbalance/loss of heterozygosity and APC protein expression in cutaneous squamous cell carcinomas.

    LENUS (Irish Health Repository)

    Gray, Sarah E

    2011-05-01

    The adenomatous polyposis coli (APC) gene is a tumor suppressor gene which is mutated in the hereditary disease, familial adenomatous polyposis (FAP). Somatic mutations of the APC gene have also been identified in the majority of sporadic colorectal carcinomas, and mutation of the APC gene appears to be an early step in the initiation of colon cancer. Loss of heterozygosity (LOH) of APC has been described in a variety of other cancer types, including renal cell carcinoma, gastric cancer, non-small cell lung cancer, endometrial cancer and oral squamous cell carcinomas (SCC).

  13. Proteomic profiling of a mouse model of acute intestinal Apc deletion leads to identification of potential novel biomarkers of human colorectal cancer (CRC).

    Science.gov (United States)

    Hammoudi, Abeer; Song, Fei; Reed, Karen R; Jenkins, Rosalind E; Meniel, Valerie S; Watson, Alastair J M; Pritchard, D Mark; Clarke, Alan R; Jenkins, John R

    2013-10-25

    Colorectal cancer (CRC) is the fourth most common cause of cancer-related death worldwide. Accurate non-invasive screening for CRC would greatly enhance a population's health. Adenomatous polyposis coli (Apc) gene mutations commonly occur in human colorectal adenomas and carcinomas, leading to Wnt signalling pathway activation. Acute conditional transgenic deletion of Apc in murine intestinal epithelium (AhCre(+)Apc(fl)(/)(fl)) causes phenotypic changes similar to those found during colorectal tumourigenesis. This study comprised a proteomic analysis of murine small intestinal epithelial cells following acute Apc deletion to identify proteins that show altered expression during human colorectal carcinogenesis, thus identifying proteins that may prove clinically useful as blood/serum biomarkers of colorectal neoplasia. Eighty-one proteins showed significantly increased expression following iTRAQ analysis, and validation of nine of these by Ingenuity Pathaway Analysis showed they could be detected in blood or serum. Expression was assessed in AhCre(+)Apc(fl)(/)(fl) small intestinal epithelium by immunohistochemistry, western blot and quantitative real-time PCR; increased nucelolin concentrations were also detected in the serum of AhCre(+)Apc(fl)(/)(fl) and Apc(Min)(/)(+) mice by ELISA. Six proteins; heat shock 60kDa protein 1, Nucleolin, Prohibitin, Cytokeratin 18, Ribosomal protein L6 and DEAD (Asp-Glu-Ala-Asp) box polypeptide 5,were selected for further investigation. Increased expression of 4 of these was confirmed in human CRC by qPCR. In conclusion, several novel candidate biomarkers have been identified from analysis of transgenic mice in which the Apc gene was deleted in the intestinal epithelium that also showed increased expression in human CRC. Some of these warrant further investigation as potential serum-based biomarkers of human CRC.

  14. Wnt signaling and colon carcinogenesis: Beyond APC

    Directory of Open Access Journals (Sweden)

    Rani Najdi

    2011-01-01

    Full Text Available Activation of the Wnt signaling pathway via mutation of the adenomatous polyposis coli gene (APC is a critical event in the development of colon cancer. For colon carcinogenesis, however, constitutive signaling through the canonical Wnt pathway is not a singular event. Here we review how canonical Wnt signaling is modulated by intracellular LEF/TCF composition and location, the action of different Wnt ligands, and the secretion of Wnt inhibitory molecules. We also review the contributions of non-canonical Wnt signaling and other distinct pathways in the tumor micro environment that cross-talk to the canonical Wnt pathway and thereby influence colon cancer progression. These ′non-APC′ aspects of Wnt signaling are considered in relation to the development of potential agents for the treatment of patients with colon cancer. Regulatory pathways that influence Wnt signaling highlight how it might be possible to design therapies that target a network of signals beyond that of APC and β-catenin.

  15. A broad phenotypic screen identifies novel phenotypes driven by a single mutant allele in Huntington's disease CAG knock-in mice.

    Directory of Open Access Journals (Sweden)

    Sabine M Hölter

    Full Text Available Huntington's disease (HD is an autosomal dominant neurodegenerative disorder caused by the expansion of a CAG trinucleotide repeat in the HTT gene encoding huntingtin. The disease has an insidious course, typically progressing over 10-15 years until death. Currently there is no effective disease-modifying therapy. To better understand the HD pathogenic process we have developed genetic HTT CAG knock-in mouse models that accurately recapitulate the HD mutation in man. Here, we describe results of a broad, standardized phenotypic screen in 10-46 week old heterozygous HdhQ111 knock-in mice, probing a wide range of physiological systems. The results of this screen revealed a number of behavioral abnormalities in HdhQ111/+ mice that include hypoactivity, decreased anxiety, motor learning and coordination deficits, and impaired olfactory discrimination. The screen also provided evidence supporting subtle cardiovascular, lung, and plasma metabolite alterations. Importantly, our results reveal that a single mutant HTT allele in the mouse is sufficient to elicit multiple phenotypic abnormalities, consistent with a dominant disease process in patients. These data provide a starting point for further investigation of several organ systems in HD, for the dissection of underlying pathogenic mechanisms and for the identification of reliable phenotypic endpoints for therapeutic testing.

  16. Wild-Type, but Not Mutant N296H, Human Tau Restores Aβ-Mediated Inhibition of LTP in Tau−/− mice

    Directory of Open Access Journals (Sweden)

    Mariana Vargas-Caballero

    2017-04-01

    Full Text Available Microtubule associated protein tau (MAPT is involved in the pathogenesis of Alzheimer's disease and many forms of frontotemporal dementia (FTD. We recently reported that Aβ-mediated inhibition of hippocampal long-term potentiation (LTP in mice requires tau. Here, we asked whether expression of human MAPT can restore Aβ-mediated inhibition on a mouse Tau−/− background and whether human tau with an FTD-causing mutation (N296H can interfere with Aβ-mediated inhibition of LTP. We used transgenic mouse lines each expressing the full human MAPT locus using bacterial artificial chromosome technology. These lines expressed all six human tau protein isoforms on a Tau−/− background. We found that the human wild-type MAPT H1 locus was able to restore Aβ42-mediated impairment of LTP. In contrast, Aβ42 did not reduce LTP in slices in two independently generated transgenic lines expressing tau protein with the mutation N296H associated with frontotemporal dementia (FTD. Basal phosphorylation of tau measured as the ratio of AT8/Tau5 immunoreactivity was significantly reduced in N296H mutant hippocampal slices. Our data show that human MAPT is able to restore Aβ42-mediated inhibition of LTP in Tau−/− mice. These results provide further evidence that tau protein is central to Aβ-induced LTP impairment and provide a valuable tool for further analysis of the links between Aβ, human tau and impairment of synaptic function.

  17. Neuronal death and synapse elimination in the olivocerebellar system. II. Cell counts in the inferior olive of adult x-irradiated rats and weaver and reeler mutant mice

    Energy Technology Data Exchange (ETDEWEB)

    Shojaeian, H.; Delhaye-Bouchaud, N.; Mariani, J.

    1985-02-15

    Cell death in the developing rat inferior olive precedes the regression of the polyneuronal innervation of Purkinje cells by olivary axons (i.e., climbing fibers), suggesting that the involution of the redundant olivocerebellar contacts is caused by a withdrawal of supernumerary axonal collaterals rather than by degeneration of the parent cell. However, a subsequent apparent increase of the olivary population occurs, which could eventually mask a residual presynaptic cell death taking place at the same time. Therefore, cell counts were performed in the inferior olive of adult rodents in which the multiple innervation of Purkinje cells by olivary axons is maintained, with the idea that if cell death plays a role in the regression of supernumerary climbing fibers, the number of olivary cells should be higher in these animals than in their controls. The results show that the size of the cell population in the inferior olive of weaver and reeler mutant mice and rats degranulated by early postnatal x-irradiation does not differ significantly from that of their controls. Similarly, the distribution of the cells in the four main olivary subnuclei is not modified in weaver mice and x-irradiated rats. The present data further support the assumption that the regression of the polyneuronal innervation of Purkinje cells occurs independently of cell death in the presynaptic population.

  18. A broad phenotypic screen identifies novel phenotypes driven by a single mutant allele in Huntington's disease CAG knock-in mice.

    Science.gov (United States)

    Hölter, Sabine M; Stromberg, Mary; Kovalenko, Marina; Garrett, Lillian; Glasl, Lisa; Lopez, Edith; Guide, Jolene; Götz, Alexander; Hans, Wolfgang; Becker, Lore; Rathkolb, Birgit; Rozman, Jan; Schrewed, Anja; Klingenspor, Martin; Klopstock, Thomas; Schulz, Holger; Wolf, Eckhard; Wursta, Wolfgang; Gillis, Tammy; Wakimoto, Hiroko; Seidman, Jonathan; MacDonald, Marcy E; Cotman, Susan; Gailus-Durner, Valérie; Fuchs, Helmut; de Angelis, Martin Hrabě; Lee, Jong-Min; Wheeler, Vanessa C

    2013-01-01

    Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder caused by the expansion of a CAG trinucleotide repeat in the HTT gene encoding huntingtin. The disease has an insidious course, typically progressing over 10-15 years until death. Currently there is no effective disease-modifying therapy. To better understand the HD pathogenic process we have developed genetic HTT CAG knock-in mouse models that accurately recapitulate the HD mutation in man. Here, we describe results of a broad, standardized phenotypic screen in 10-46 week old heterozygous HdhQ111 knock-in mice, probing a wide range of physiological systems. The results of this screen revealed a number of behavioral abnormalities in HdhQ111/+ mice that include hypoactivity, decreased anxiety, motor learning and coordination deficits, and impaired olfactory discrimination. The screen also provided evidence supporting subtle cardiovascular, lung, and plasma metabolite alterations. Importantly, our results reveal that a single mutant HTT allele in the mouse is sufficient to elicit multiple phenotypic abnormalities, consistent with a dominant disease process in patients. These data provide a starting point for further investigation of several organ systems in HD, for the dissection of underlying pathogenic mechanisms and for the identification of reliable phenotypic endpoints for therapeutic testing.

  19. Evaluation of genetic melanoma vaccines in cdk4-mutant mice provides evidence for immunological tolerance against authochthonous melanomas in the skin.

    Science.gov (United States)

    Steitz, Julia; Büchs, Stefanie; Tormo, Damia; Ferrer, Aleix; Wenzel, Jörg; Huber, Christoph; Wölfel, Thomas; Barbacid, Mariano; Malumbres, Marcos; Tüting, Thomas

    2006-01-15

    We evaluated the efficacy of a candidate melanoma vaccine approach in mice genetically prone to develop melanoma due to the introduction of an oncogenic mutation (R24C) in the germline sequence of the cyclin-dependent kinase 4 (cdk4), a protein critically involved in cell cycle regulation. Melanomas were induced in cdk4-mutant mice by chemical carcinogenesis and UVB irradiation. A genetic prime-boost strategy targeting the clinically relevant differentiation antigen tyrosinase-related protein 2 (TRP2) was performed which was able to stimulate a melanocyte-specific cellular immune response associated with localized autoimmune vitiligo-like depigmentation. However, significant destruction of carcinogen-induced autochthonous melanocytic neoplasms in the skin was not observed following immunization. We provide evidence that autochthonous melanomas expressed TRP2 but not the MHC molecule H2-Kb and are immunologically tolerated in the skin. Our results highlight the importance of assessing melanoma vaccines in genetic mouse models that more adequately represent the expected clinical situation in order to identify strategies, which eventually may be of benefit for melanoma patients.

  20. Feedback regulation between atypical E2Fs and APC/CCdh1 coordinates cell cycle progression.

    Science.gov (United States)

    Boekhout, Michiel; Yuan, Ruixue; Wondergem, Annelotte P; Segeren, Hendrika A; van Liere, Elsbeth A; Awol, Nesibu; Jansen, Imke; Wolthuis, Rob M F; de Bruin, Alain; Westendorp, Bart

    2016-03-01

    E2F transcription factors control the oscillating expression pattern of multiple target genes during the cell cycle. Activator E2Fs, E2F1-3, induce an upswing of E2F targets, which is essential for the G1-to-S phase transition, whereas atypical E2Fs, E2F7 and E2F8, mediate a downswing of the same targets during late S, G2, and M phases. Expression of atypical E2Fs is induced by E2F1-3, but it is unknown how atypical E2Fs are inactivated in a timely manner. Here, we demonstrate that E2F7 and E2F8 are substrates of the anaphase-promoting complex/cyclosome (APC/C). Removal of CDH1, or mutating the CDH1-interacting KEN boxes, stabilized E2F7/8 from anaphase onwards and during G1. Expressing KEN mutant E2F7 during G1 impairs S phase entry and eventually results in cell death. Furthermore, we show that E2F8, but not E2F7, interacts also with APC/C(C) (dc20). Importantly, atypical E2Fs can activate APC/C(C) (dh1) by repressing its inhibitors cyclin A, cyclin E, and Emi1. In conclusion, we discovered a feedback loop between atypical E2Fs and APC/C(C) (dh1), which ensures balanced expression of cell cycle genes and normal cell cycle progression.

  1. Myc deletion rescues Apc deficiency in the small intestine

    NARCIS (Netherlands)

    Sansom, O.J.; Meniel, V.S.; Muncan, V.; Phesse, T.J.; Wilkins, J.A.; Reed, K.R.; Vass, J.K.; Athineos, D.; Clevers, J.C.; Clarke, A.R.

    2007-01-01

    The APC gene encodes the adenomatous polyposis coli tumour suppressor protein, germline mutation of which characterizes familial adenomatous polyposis (FAP), an autosomal intestinal cancer syndrome. Inactivation of APC is also recognized as the key early event in the development of sporadic colorect

  2. Dietary factors and Truncating APC Mutations in Sporadic Colorectal Adenomas

    NARCIS (Netherlands)

    Diergaarde, B.; Tiemersma, E.W.; Braam, H.; Muijen, van G.N.P.; Nagengast, F.M.; Kok, F.J.; Kampman, E.

    2005-01-01

    Inactivating mutations in APC are thought to be early, initiating events in colorectal carcinogenesis. To gain insight into the relationship between diet and inactivating APC mutations, we evaluated associations between dietary factors and the occurrence of these mutations in a Dutch case-control st

  3. Dietary factors and truncating APC mutations in sporadic colorectal adenomas.

    NARCIS (Netherlands)

    Diergaarde, B.; Tiemersma, E.W.; Braam, H.; Muijen, G.N.P. van; Nagengast, F.M.; Kok, F.J.; Kampman, E.

    2005-01-01

    Inactivating mutations in APC are thought to be early, initiating events in colorectal carcinogenesis. To gain insight into the relationship between diet and inactivating APC mutations, we evaluated associations between dietary factors and the occurrence of these mutations in a Dutch case-control st

  4. To cell cycle, swing the APC/C

    NARCIS (Netherlands)

    van Leuken, Renske; Clijsters, Linda; Wolthuis, Rob

    2008-01-01

    For successful mitosis, Cyclin 131 and Securin must be degraded efficiently before anaphase. Destruction of these mitotic regulators by the 26S proteasome is the result of their poly-ubiquitination by a multi-subunit E3 ligase: the Anaphase-Promoting Complex or Cyclosome (APC/C). Clearly, the APC/C

  5. Early degenerative changes in transgenic mice expressing mutant huntingtin involve dendritic abnormalities but no impairment of mitochondrial energy production.

    Science.gov (United States)

    Guidetti, P; Charles, V; Chen, E Y; Reddy, P H; Kordower, J H; Whetsell, W O; Schwarcz, R; Tagle, D A

    2001-06-01

    Mitochondrial defects, which occur in the brain of late-stage Huntington's disease (HD) patients, have been proposed to underlie the selective neuronal loss in the disease. To shed light on the possible role of mitochondrial energy impairment in the early phases of HD pathophysiology, we carried out Golgi impregnation and quantitative histochemical/biochemical studies in HD full-length cDNA transgenic mice that were symptomatic but had not developed to a stage in which neuronal loss could be documented. Golgi staining showed morphologic abnormalities that included a significant decrease in the number of dendritic spines and a thickening of proximal dendrites in striatal and cortical neurons. In contrast, measurements of mitochondrial electron transport Complexes I-IV did not reveal changes in the striatum and cerebral cortex in these mice. Examination of the neostriatum and cerebral cortex in human presymptomatic and pathological Grade 1 HD cases also showed no change in the activity of mitochondrial Complexes I-IV. These data suggest that dendritic alterations precede irreversible cell loss in HD, and that mitochondrial energy impairment is a consequence, rather than a cause, of early neuropathological changes.

  6. Distinct phenotypes of new transmembrane-domain neuregulin 1 mutant mice and the rescue effects of valproate on the observed schizophrenia-related cognitive deficits.

    Directory of Open Access Journals (Sweden)

    Ju-Chun ePei

    2014-04-01

    Full Text Available Accumulating evidence suggests that neuregulin 1 (NRG1 might be involved in the neurodevelopment, neural plasticity, GABAergic neurotransmission and pathogenesis of schizophrenia. NRG1 is abundantly expressed in the hippocampus, and emerging studies have begun to reveal the link between NRG1 signaling and cognitive deficits in schizophrenic patients. Because the transmembrane domain of NRG1 is vital for both forward and reverse signaling cascades, new Nrg1-deficient mice that carry a truncation of the transmembrane domain of the Nrg1 gene were characterized and used in this study to test a NRG1 loss-of-function hypothesis for schizophrenia. Both male and female Nrg1 heterozygous mutant mice and their wild-type littermates were used in a series of 4 experiments to characterize the impact of Nrg1 on behavioral phenotypes and to determine the importance of Nrg1 in the regulation of hippocampal neuromorphology and local GABAergic interneurons. First, a comprehensive battery of behavioral tasks indicated that male Nrg1-deficient mice exhibited significant impairments in cognitive functions. Second, pharmacological challenges were conducted and revealed that Nrg1 haploinsufficiency altered GABAergic activity in males. Third, although no genotype-specific neuromorphological alterations were found in the hippocampal CA1 pyramidal neurons, significant reductions in the hippocampal expressions of GAD67 and parvalbumin were revealed in the Nrg1-deficient males. Fourth, chronic treatment with valproate rescued the observed behavioral deficits and hippocampal GAD67 reduction in Nrg1-deficient males. Collectively, these results indicate the potential therapeutic effect of valproate and the importance of Nrg1 in the regulation of cognitive functions and hippocampal GABAergic interneurons, especially in males.

  7. Drosophila-Cdh1 (Rap/Fzr) a regulatory subunit of APC/C is required for synaptic morphology, synaptic transmission and locomotion

    Science.gov (United States)

    Wise, Alexandria; Schatoff, Emma; Flores, Julian; Hua, Shao-Ying; Ueda, Atsushi; Wu, Chun-Fang; Venkatesh, Tadmiri

    2013-01-01

    The assembly of functional synapses requires the orchestration of the synthesis and degradation of a multitude of proteins. Protein degradation and modification by the conserved ubiquitination pathway has emerged as a key cellular regulatory mechanism during nervous system development and function (Kawabe and Brose, 2011). The anaphase promoting complex/cyclosome (APC/C) is a multi-subunit ubiquitin ligase complex primarily characterized for its role in the regulation of mitosis (Peters, 2002). In recent years, a role for APC/C in nervous system development and function has been rapidly emerging (Stegmuller and Bonni, 2005; Li et al., 2008). In the mammalian central nervous system the activator subunit, APC/C-Cdh1, has been shown to be a regulator of axon growth and dendrite morphogenesis (Konishi et al. 2004). In the Drosophila peripheral nervous system (PNS), APC2, a ligase subunit of the APC/C complex has been shown to regulate synaptic bouton size and activity (Van Roessel et al., 2004). To investigate the role of APC/C-Cdh1 at the synapse we examined loss-of-function mutants of Rap/Fzr (Retina aberrant in pattern/Fizzy related), a Drosophila homolog of the mammalian Cdh1 during the development of the larval neuromuscular junction in Drosophila. Our cell biological, ultrastructural, electrophysiological, and behavioral data showed that rap/fzr loss-of-function mutations lead to changes in synaptic structure and function as well as locomotion defects. Data presented here show changes in size and morphology of synaptic boutons, and, muscle tissue organization. Electrophysiological experiments show that loss-of-function mutants exhibit increased frequency of spontaneous miniature synaptic potentials, indicating a higher rate of spontaneous synaptic vesicle fusion events. In addition, larval locomotion and peristaltic movement were also impaired. These findings suggest a role for Drosophila APC/C-Cdh1 mediated ubiquitination in regulating synaptic morphology

  8. Intramuscular Immunization of Mice with a Live-Attenuated Triple Mutant of Yersinia pestis CO92 Induces Robust Humoral and Cell-Mediated Immunity To Completely Protect Animals against Pneumonic Plague.

    Science.gov (United States)

    Tiner, Bethany L; Sha, Jian; Ponnusamy, Duraisamy; Baze, Wallace B; Fitts, Eric C; Popov, Vsevolod L; van Lier, Christina J; Erova, Tatiana E; Chopra, Ashok K

    2015-12-01

    Earlier, we showed that the Δlpp ΔmsbB Δail triple mutant of Yersinia pestis CO92 with deleted genes encoding Braun lipoprotein (Lpp), an acyltransferase (MsbB), and the attachment invasion locus (Ail), respectively, was avirulent in a mouse model of pneumonic plague. In this study, we further evaluated the immunogenic potential of the Δlpp ΔmsbB Δail triple mutant and its derivative by different routes of vaccination. Mice were immunized via the subcutaneous (s.c.) or the intramuscular (i.m.) route with two doses (2 × 10(6) CFU/dose) of the above-mentioned triple mutant with 100% survivability of the animals. Upon subsequent pneumonic challenge with 70 to 92 50% lethal doses (LD(50)) of wild-type (WT) strain CO92, all of the mice survived when immunization occurred by the i.m. route. Since Ail has virulence and immunogenic potential, a mutated version of Ail devoid of its virulence properties was created, and the genetically modified ail replaced the native ail gene on the chromosome of the Δlpp ΔmsbB double mutant, creating a Δlpp ΔmsbB::ailL2 vaccine strain. This newly generated mutant was attenuated similarly to the Δlpp ΔmsbB Δail triple mutant when administered by the i.m. route and provided 100% protection to animals against subsequent pneumonic challenge. Not only were the two above-mentioned mutants cleared rapidly from the initial i.m. site of injection in animals with no histopathological lesions, the immunized mice did not exhibit any disease symptoms during immunization or after subsequent exposure to WT CO92. These two mutants triggered balanced Th1- and Th2-based antibody responses and cell-mediated immunity. A substantial increase in interleukin-17 (IL-17) from the T cells of vaccinated mice, a cytokine of the Th17 cells, further augmented their vaccine potential. Thus, the Δlpp ΔmsbB Δail and Δlpp ΔmsbB::ailL2 mutants represent excellent vaccine candidates for plague, with the latter mutant still retaining Ail immunogenicity but

  9. Novel strategies for comprehensive mutation screening of the APC gene.

    Science.gov (United States)

    Wachsmannova, L; Mego, M; Stevurkova, V; Zajac, V; Ciernikova, S

    2017-03-03

    Colorectal cancer is the 4th most common cause of cancer related deaths worldwide and new possibilities in accurate diagnosis and targeted treatment are highly required. Mutations in adenomatous polyposis coli (APC) gene play a pivotal role in adenoma-carcinoma pathway of colorectal tumorigenesis. The quarter century from its´ first cloning, APC became one of the most frequently mutated, known driver genes in colorectal cancer. Intensive routine molecular testing of APC has brought the benefits for patients with family history of polyposis or colorectal cancer. Nevertheless, multiple mutational disease-causing mechanisms make the genetic testing still challenging. This minireview is focused on implementation of novel APC mutation screening diagnostic strategies for polyposis families according to the current findings. A further understanding and improved algorithms may help to increase the mutation detection rate. APC germline mutations achieve close to 100% penetrance, so more comprehensive approach followed by preventive and therapeutic strategies might reflect in decrease in burden of colorectal cancer.

  10. Cdh1 regulates craniofacial development via APC-dependent ubiquitination and activation of Goosecoid.

    Science.gov (United States)

    Shao, Rui; Liu, Jia; Yan, Guang; Zhang, Jinfang; Han, Yujiao; Guo, Jianfeng; Xu, Zhan; Yuan, Zhu; Liu, Jiankang; Malumbres, Marcos; Wan, Lixin; Wei, Wenyi; Zou, Weiguo

    2016-06-01

    Craniofacial anomalies (CFAs) characterized by birth defects of skull and facial bones are the most frequent congenital disease. Genomic analysis has identified multiple genes responsible for CFAs; however, the underlying genetic mechanisms for the majority of CFAs remain largely unclear. Our previous study revealed that the Wwp2 E3 ubiquitin ligase facilitates craniofacial development in part through inducing monoubiquitination and activation of the paired-like homeobox transcription factor, Goosecoid (Gsc). Here we report that Gsc is also ubiquitinated and activated by the APC(Cdh1) E3 ubiquitin ligase, leading to transcriptional activation of various Gsc target genes crucial for craniofacial development. Consistenly, neural crest-specific Cdh1-knockout mice display similar bone malformation as Wwp2-deficient mice in the craniofacial region, characterized by a domed skull, a short snout and a twisted nasal bone. Mechanistically, like Wwp2-deficient mice, mice with Cdh1 deficiency in neural crest cells exhibit reduced Gsc/Sox6 transcriptional activities. Simultaneous deletion of Cdh1 and Wwp2 results in a more severe craniofacial defect compared with single gene deletion, suggesting a synergistic augmentation of Gsc activity by these two E3 ubiquitin ligases. Hence, our study reveals a novel role for Cdh1 in craniofacial development through promoting APC-dependent non-proteolytic ubiquitination and activation of Gsc.

  11. P301S mutant human tau transgenic mice manifest early symptoms of human tauopathies with dementia and altered sensorimotor gating.

    Directory of Open Access Journals (Sweden)

    Hiroki Takeuchi

    Full Text Available Tauopathies are neurodegenerative disorders characterized by the accumulation of abnormal tau protein leading to cognitive and/or motor dysfunction. To understand the relationship between tau pathology and behavioral impairments, we comprehensively assessed behavioral abnormalities in a mouse tauopathy model expressing the human P301S mutant tau protein in the early stage of disease to detect its initial neurological manifestations. Behavioral abnormalities, shown by open field test, elevated plus-maze test, hot plate test, Y-maze test, Barnes maze test, Morris water maze test, and/or contextual fear conditioning test, recapitulated the neurological deficits of human tauopathies with dementia. Furthermore, we discovered that prepulse inhibition (PPI, a marker of sensorimotor gating, was enhanced in these animals concomitantly with initial neuropathological changes in associated brain regions. This finding provides evidence that our tauopathy mouse model displays neurofunctional abnormalities in prodromal stages of disease, since enhancement of PPI is characteristic of amnestic mild cognitive impairment, a transitional stage between normal aging and dementia such as Alzheimer's disease (AD, in contrast with attenuated PPI in AD patients. Therefore, assessment of sensorimotor gating could be used to detect the earliest manifestations of tauopathies exemplified by prodromal AD, in which abnormal tau protein may play critical roles in the onset of neuronal dysfunctions.

  12. Na(v)1.8 channelopathy in mutant mice deficient for myelin protein zero is detrimental to motor axons

    DEFF Research Database (Denmark)

    Alvarez Herrero, Susana; Pinchenko, Volodymyr; Klein, Dennis

    2011-01-01

    by pharmacologic block using the subtype-selective Na(V)1.8 blocker A-803467 and chronically in Na(V)1.8 knock-outs. We found that in the context of dysmyelination, abnormal potassium ion currents and membrane depolarization, the ectopic Na(V)1.8 channels further impair the motor axon excitability in protein zero...... and progressive dysmyelinating neuropathy from birth with compromised myelin compaction, hypomyelination and distal axonal degeneration. A previous study using immunofluorescence showed that motor nerves deficient of myelin protein zero upregulate the Na(V)1.8 voltage gated sodium channel isoform, which...... is normally present only in restricted populations of sensory axons. The aim of this study was to investigate the function of motor axons in protein zero-deficient mice with particular emphasis on ectopic Na(V)1.8 voltage gated sodium channel. We combined 'threshold tracking' excitability studies...

  13. Identification of five novel modifier loci of Apc(Min) harbored in the BXH14 recombinant inbred strain.

    Science.gov (United States)

    Nnadi, Stephanie C; Watson, Rayneisha; Innocent, Julie; Gonye, Gregory E; Buchberg, Arthur M; Siracusa, Linda D

    2012-08-01

    Every year thousands of people in the USA are diagnosed with small intestine and colorectal cancers (CRC). Although environmental factors affect disease etiology, uncovering underlying genetic factors is imperative for risk assessment and developing preventative therapies. Familial adenomatous polyposis is a heritable genetic disorder in which individuals carry germ-line mutations in the adenomatous polyposis coli (APC) gene that predisposes them to CRC. The Apc ( Min ) mouse model carries a point mutation in the Apc gene and develops polyps along the intestinal tract. Inbred strain background influences polyp phenotypes in Apc ( Min ) mice. Several Modifier of Min (Mom) loci that alter tumor phenotypes associated with the Apc ( Min ) mutation have been identified to date. We screened BXH recombinant inbred (RI) strains by crossing BXH RI females with C57BL/6J (B6) Apc ( Min ) males and quantitating tumor phenotypes in backcross progeny. We found that the BXH14 RI strain harbors five modifier loci that decrease polyp multiplicity. Furthermore, we show that resistance is determined by varying combinations of these modifier loci. Gene interaction network analysis shows that there are multiple networks with proven gene-gene interactions, which contain genes from all five modifier loci. We discuss the implications of this result for studies that define susceptibility loci, namely that multiple networks may be acting concurrently to alter tumor phenotypes. Thus, the significance of this work resides not only with the modifier loci we identified but also with the combinations of loci needed to get maximal protection against polyposis and the impact of this finding on human disease studies.

  14. Deregulation of type I IFN-dependent genes correlates with increased susceptibility to cytomegalovirus acute infection of dicer mutant mice.

    Directory of Open Access Journals (Sweden)

    Eleonore Ostermann

    Full Text Available Regulation of gene expression by microRNAs (miRNAs is now considered as an essential mechanism for cell development and homeostasis. Indeed, numerous studies have reported that modulating their expression, maturation, or activity can affect cell survival, identity or activation. In particular, miRNAs are key players in the tight regulation of signaling cascades, and as such, they appear as perfectly suited immunomodulators. Several immune-related processes, including inflammation, have recently been demonstrated to require specific miRNAs. In addition, the discovery of herpesvirus-encoded miRNAs has reinforced this assumption. To decipher the potential roles of miRNAs in innate antiviral immune response, we developed an in vivo model based on the inoculation of mouse cytomegalovirus (MCMV in mice. Furthermore, we exploited a mouse line carrying a hypomorphic mutation in the Dicer gene to visualize the impact of impaired miRNA biogenesis upon the anti-MCMV response. Our data indicate that miRNAs are important actors in mounting an efficient response against herpesviruses. We suggest that a rapid and transient interferon response following viral infection requires miRNA-dependent repressor release. In addition, our in vivo efforts identified several miRNA targets, thus providing a conceptual framework for future analyzes on the regulation of specific actors involved in the Type I interferon pathway.

  15. Somatic hypermutation of immunoglobulin genes: lessons from proliferating cell nuclear antigenK164R mutant mice.

    Science.gov (United States)

    Langerak, Petra; Krijger, Peter H L; Heideman, Marinus R; van den Berk, Paul C M; Jacobs, Heinz

    2009-03-12

    Proliferating cell nuclear antigen (PCNA) encircles DNA as a ring-shaped homotrimer and, by tethering DNA polymerases to their template, PCNA serves as a critical replication factor. In contrast to high-fidelity DNA polymerases, the activation of low-fidelity translesion synthesis (TLS) DNA polymerases seems to require damage-inducible monoubiquitylation (Ub) of PCNA at lysine residue 164 (PCNA-Ub). TLS polymerases can tolerate DNA damage, i.e. they can replicate across DNA lesions. The lack of proofreading activity, however, renders TLS highly mutagenic. The advantage is that B cells use mutagenic TLS to introduce somatic mutations in immunoglobulin (Ig) genes to generate high-affinity antibodies. Given the critical role of PCNA-Ub in activating TLS and the role of TLS in establishing somatic mutations in immunoglobulin genes, we analysed the mutation spectrum of somatically mutated immunoglobulin genes in B cells from PCNAK164R knock-in mice. A 10-fold reduction in A/T mutations is associated with a compensatory increase in G/C mutations-a phenotype similar to Poleta and mismatch repair-deficient B cells. Mismatch recognition, PCNA-Ub and Poleta probably act within one pathway to establish the majority of mutations at template A/T. Equally relevant, the G/C mutator(s) seems largely independent of PCNAK(164) modification.

  16. Mice lacking Ras-GRF1 show contextual fear conditioning but not spatial memory impairments: convergent evidence from two independently generated mouse mutant lines

    Directory of Open Access Journals (Sweden)

    Raffaele ed'Isa

    2011-12-01

    Full Text Available Ras-GRF1 is a neuronal specific guanine exchange factor that, once activated by both ionotropic and metabotropic neurotransmitter receptors, can stimulate Ras proteins, leading to long-term phosphorylation of downstream signaling. The two available reports on the behavior of two independently generated Ras-GRF1 deficient mouse lines provide contrasting evidence on the role of Ras-GRF1 in spatial memory and contextual fear conditioning. These discrepancies may be due to the distinct alterations introduced in the mouse genome by gene targeting in the two lines that could differentially affect expression of nearby genes located in the imprinted region containing the Ras-grf1 locus. In order to determine the real contribution of Ras-GRF1 to spatial memory we compared in Morris Water Maze learning the Brambilla’s mice with a third mouse line (GENA53 in which a nonsense mutation was introduced in the Ras-GRF1 coding region without additional changes in the genome and we found that memory in this task is normal. Also, we measured both contextual and cued fear conditioning, which were previously reported to be affected in the Brambilla’s mice, and we confirmed that contextual learning but not cued conditioning is impaired in both mouse lines. In addition, we also tested both lines for the first time in conditioned place aversion in the Intellicage, an ecological and remotely controlled behavioral test, and we observed normal learning. Finally, based on previous reports of other mutant lines suggesting that Ras-GRF1 may control body weight, we also measured this non-cognitive phenotype and we confirmed that both Ras-GRF1 deficient mutants are smaller than their control littermates. In conclusion, we demonstrate that Ras-GRF1 has no unique role in spatial memory while its function in contextual fear conditioning is likely to be due not only to its involvement in amygdalar functions but possibly to some distinct hippocampal connections specific to

  17. Paradoxical effects of prenatal acetylcholinesterase blockade on neuro-behavioral development and drug-induced stereotypies in reeler mutant mice.

    Science.gov (United States)

    Laviola, Giovanni; Adriani, Walter; Gaudino, Chiara; Marino, Ramona; Keller, Flavio

    2006-08-01

    Epidemiological and experimental studies support a link between genetic and epigenetic factors in vulnerability to develop enduring neurobehavioral alterations. We studied the interplay between genetic vulnerability and the prenatal exposure to a neurotoxic compound. Chlorpyrifos, a potent and reversible acetylcholinesterase blocker used as a pesticide, and the "reeler" mouse, lacking the extracellular-matrix protein Reelin, were used. Homozygous reeler (RL), heterozygous (HZ), and wild-type (WT) mice were prenatally exposed to chlorpyrifos-oxon (CPF-O), the active metabolite of chlorpyrifos, or to vehicle (prenatal controls) on gestation days 14-16, that is, during a peak period of neurogenesis in the cerebral cortex. The offspring was reared by the natural dam and tested during infancy and at adulthood for global consequences of the prenatal exposure. The results are consistent with complex interactions between genetic (reeler genotype) and epigenetic (prenatal exposure to CPF-O) factors. In the case of some "genetically modulated" parameters (ultrasound vocalization, amphetamine-induced locomotion, and stereotypy), exposure to CPF-O paradoxically reverted the effects produced by progressive reelin absence. Conversely, for an "epigenetically modulated" parameter (grasping reflex maturation), the effects of CPF-O exposure were counteracted by progressive reelin absence. Finally, for parameters apparently untouched by either factor alone (righting reflex latency, scopolamine-induced locomotor activity), prenatal CPF-O exposure unmasked an otherwise latent genotype dependency. This complex picture also points to reciprocal adaptations within cholinergic and dopaminergic systems during development. Data are interesting in view of recently discovered cholinergic abnormalities in autism and schizophrenia, and may suggest new avenues for early intervention.

  18. The anabolic/androgenic steroid nandrolone exacerbates gene expression modifications induced by mutant SOD1 in muscles of mice models of amyotrophic lateral sclerosis.

    Science.gov (United States)

    Galbiati, Mariarita; Onesto, Elisa; Zito, Arianna; Crippa, Valeria; Rusmini, Paola; Mariotti, Raffaella; Bentivoglio, Marina; Bendotti, Caterina; Poletti, Angelo

    2012-02-01

    Anabolic/androgenic steroids (AAS) are drugs that enhance muscle mass, and are often illegally utilized in athletes to improve their performances. Recent data suggest that the increased risk for amyotrophic lateral sclerosis (ALS) in male soccer and football players could be linked to AAS abuse. ALS is a motor neuron disease mainly occurring in sporadic (sALS) forms, but some familial forms (fALS) exist and have been linked to mutations in different genes. Some of these, in their wild type (wt) form, have been proposed as risk factors for sALS, i.e. superoxide dismutase 1 (SOD1) gene, whose mutations are causative of about 20% of fALS. Notably, SOD1 toxicity might occur both in motor neurons and in muscle cells. Using gastrocnemius muscles of mice overexpressing human mutant SOD1 (mutSOD1) at different disease stages, we found that the expression of a selected set of genes associated to muscle atrophy, MyoD, myogenin, atrogin-1, and transforming growth factor (TGF)β1, is up-regulated already at the presymptomatic stage. Atrogin-1 gene expression was increased also in mice overexpressing human wtSOD1. Similar alterations were found in axotomized mouse muscles and in cultured ALS myoblast models. In these ALS models, we then evaluated the pharmacological effects of the synthetic AAS nandrolone on the expression of the genes modified in ALS muscle. Nandrolone administration had no effects on MyoD, myogenin, and atrogin-1 expression, but it significantly increased TGFβ1 expression at disease onset. Altogether, these data suggest that, in fALS, muscle gene expression is altered at early stages, and AAS may exacerbate some of the alterations induced by SOD1 possibly acting as a contributing factor also in sALS. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Dietary folate and APC mutations in sporadic colorectal cancer.

    Science.gov (United States)

    de Vogel, Stefan; van Engeland, Manon; Lüchtenborg, Margreet; de Bruïne, Adriaan P; Roemen, Guido M J M; Lentjes, Marjolein H F M; Goldbohm, R Alexandra; van den Brandt, Piet A; de Goeij, Anton F P M; Weijenberg, Matty P

    2006-12-01

    Folate deficiency has been associated with colorectal cancer risk and may be involved in colorectal carcinogenesis through increased chromosome instability, gene mutations, and aberrant DNA methylation. Within the Netherlands Cohort Study on diet and cancer, we investigated the associations between dietary folate intake and colorectal cancer risk with (APC(+)) and without (APC(-)) truncating APC mutations, accounting for hMLH1 expression and K-ras mutations. In total, 528 cases and 4200 subcohort members were available for data analyses of the study cohort (n = 120,852) from a follow-up period between 2.3 and 7.3 y after baseline. Adjusted gender-specific incidence rate ratios (RR) over tertiles of folate intake were calculated in case-cohort analyses for colon and rectal cancer. Although relatively high folate intake was not associated with overall colorectal cancer risk, it reduced the risk of APC(-)colon tumors in men (RR 0.58, 95% CI 0.32-1.05, P(trend) = 0.06 for the highest vs. lowest tertile of folate intake). In contrast, it was positively associated with APC(+) colon tumors in men (highest vs. lowest tertile: RR 2.77, 95% CI 1.29-5.95, P(trend) = 0.008) and was even stronger when the lack of hMLH1 expression and K-ras mutations were excluded (RR 3.99, 95% CI 1.43-11.14, P(trend) = 0.007). Such positive associations were not observed among women; nor was folate intake associated with rectal cancer when APC mutation status was taken into account. Relatively high folate consumption reduced the risk of APC(-) colon tumors, but folate intake was positively associated with APC(+) colon tumors among men. These opposite results may indicate that folate enhances colorectal carcinogenesis through a distinct APC mutated pathway.

  20. Intra-bone marrow-bone marrow transplantation slows disease progression and prolongs survival in G93A mutant SOD1 transgenic mice, an animal model mouse for amyotrophic lateral sclerosis.

    Science.gov (United States)

    Ohnishi, Shizuo; Ito, Hidefumi; Suzuki, Yasuhiro; Adachi, Yasushi; Wate, Reika; Zhang, Jianhua; Nakano, Satoshi; Kusaka, Hirofumi; Ikehara, Susumu

    2009-11-03

    It has been reported that bone marrow transplantation (BMT) has clinical effects on not only hematopoietic diseases and autoimmune diseases but also solid malignant tumors and metabolic diseases. We have found that intra-bone marrow-bone marrow transplantation (IBM-BMT) is superior to conventional intravenous BMT, since IBM-BMT enables rapid recovery of donor hematopoiesis and reduces the extent of graft-versus-host disease (GVHD). In this experiment, we examined the effects of IBM-BMT on symptomatic G93A mutant SOD1 transgenic mice (mSOD1 Tg mice), a model mouse line for amyotrophic lateral sclerosis (ALS). Symptomatic mSOD1 Tg mice (12 weeks old) were irradiated with 6Gyx2 at a 4-hour interval, one day before IBM-BMT. The mice were transplanted with bone marrow cells (BMCs) from 12-wk-old eGFP-transgenic C57BL/6 mice (eGFP Tg mice) or BMCs from 12-wk-old mSOD1 Tg mice. The ALS model mice transplanted with BMCs from eGFP Tg mice showed longer survival and slower disease progression than those transplanted with BMCs from mSOD1 Tg mice or untreated mSOD1 Tg mice. There was a significantly high number of eGFP(+) cells in the anterior horn of the spinal cord of the mSOD1 Tg mice transplanted with BMCs of eGFP Tg mice, some of which expressed Iba-1, a marker of microglia, although they did not differentiate into neural cells. These results suggest that the replacement with normal hematopoietic cells improved the neural cell environment, thereby slowing the progression of the disease.

  1. Suppression of IRAK1 or IRAK4 Catalytic Activity, but Not Type 1 IFN Signaling, Prevents Lupus Nephritis in Mice Expressing a Ubiquitin Binding-Defective Mutant of ABIN1.

    Science.gov (United States)

    Nanda, Sambit K; Lopez-Pelaez, Marta; Arthur, J Simon C; Marchesi, Francesco; Cohen, Philip

    2016-12-01

    Polymorphisms in the TNIP1 gene encoding A20-binding inhibitor of NF-κB1 (ABIN1) predispose to lupus and other autoimmune diseases in at least eight human populations. We found previously that knock-in mice expressing a ubiquitin-binding-defective mutant of ABIN1 (ABIN1[D485N]) develop autoimmunity as they age and succumb to a disease resembling lupus nephritis in humans. In this article, we report that Flt3-derived dendritic cells from these mice overproduced type 1 IFNs upon stimulation with ligands that activate TLR7 or TLR9. However, crossing ABIN1[D485N] mice to IFNAR1-knockout mice that do not express the α-subunit of the type 1 IFNR did not prevent splenomegaly, the appearance of high serum levels of autoantibodies and other Igs, or liver inflammation and only reduced kidney inflammation modestly. In contrast, crossing ABIN1[D485N] mice to knock-in mice expressing catalytically inactive mutants of IRAK1 or IRAK4 prevented splenomegaly, autoimmunity, and liver and kidney inflammation. Our results support the notion that IRAK1 and/or IRAK4 are attractive targets for the development of drugs to prevent, and perhaps treat, lupus nephritis and other autoinflammatory diseases caused by the decreased ability of ABIN1 or other proteins to restrict the strength of MyD88 signaling. Copyright © 2016 The Authors.

  2. Lovastatin, but not orlistat, reduces intestinal polyp volume in an ApcMin/+ mouse model.

    Science.gov (United States)

    Notarnicola, Maria; Barone, Michele; Francavilla, Antonio; Tutino, Valeria; Bianco, Giusy; Tafaro, Angela; Minoia, Mario; Polimeno, Lorenzo; Napoli, Anna; Scavo, Maria Principia; Caruso, Maria Gabriella

    2016-08-01

    The statins, inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCoAR) and orlistat, an inhibitor of fatty acid synthase (FAS), inhibit tumor cell growth by restricting cholesterol and fatty acid synthesis, respectively. We previously demonstrated that an omega (ω)-3 polyunsaturated fatty acid (PUFA)- or olive oil-enriched diet reduced the polyp number and volume in ApcMin/+ mice. This phenomenon was associated with a significant inhibition of FAS and HMGCoAR, as well as an increase in the estrogen receptor (ER)β/α ratio. Herein, we evaluated the effect of lovastatin and orlistat on polyp development and ER expression in ApcMin/+ mice, in order to confirm previous data obtained with ω‑3-PUFAs and olive oil. As expected, the use of lovastatin and orlistat significantly reduced HMGCoAR and FAS enzymatic activities and gene expression in colonic tissues, but did not affect the number of intestinal polyps, while there was a statistically significant reduction in polyp volume only in the mouse group treated with lovastatin. In the mice receiving orlistat, we observed a significant increase in cell proliferation in the polyp tissue, as well as enhanced expression of ERα. Moreover, the overexpression of ERα was associated with a statistically significant increase in PES1, Shh and Gli1 protein levels, considered ERα-related molecular targets.

  3. Spontaneous hyperactivity in mutant mice lacking the NMDA receptor GluRepsilon1 subunit is aggravated during exposure to 0.1 MAC sevoflurane and is preserved after emergence from sevoflurane anaesthesia.

    Science.gov (United States)

    Petrenko, A B; Kohno, T; Wu, J; Sakimura, K; Baba, H

    2008-12-01

    Patients who awake from sevoflurane anaesthesia with symptoms of agitation may have some underlying functional substrate that is sensitive to the low concentrations of anaesthetic encountered during emergence. One candidate for such a substrate could be neurocircuitry implied in the pathophysiology of both agitation and movement disorders with hyperactivity. We postulated that hyperactive animals would show a further increase in activity in the presence of low concentrations of volatile anaesthetics, such as sevoflurane. To confirm our hypothesis, we examined the effects of two subanaesthetic concentrations of sevoflurane, isoflurane and halothane (0.1 and 0.2 MAC (minimum alveolar concentration)) on spontaneous activity in N-methyl-d-aspartate receptor GluRepsilon1 subunit knockout mice exhibiting locomotor hyperactivity in a novel environment and compared these results with those for wild-type controls. We also compared the effects of anaesthetic concentrations of sevoflurane (1.2 MAC) on mice activity during postanaesthesia recovery. Out of the three anaesthetics used, only sevoflurane administered at 0.1 MAC caused a significantly different response between the two experimental groups. Exposure to this subanaesthetic concentration of sevoflurane reduced the activity of wild-type mice, whereas mutant animals showed a further increase in hyperactivity. The effects of 1.2 MAC sevoflurane anaesthesia on mice activity during postanaesthesia recovery also differed significantly between the two genotypes. Exposure to anaesthetic concentrations of sevoflurane had a sedative effect on wild-type mice, whereas mutant mice preserved their high levels of activity upon emergence from the anaesthesia. The presence of an inherent anomaly in mutant mice that becomes more manifest during exposure to 0.1 MAC sevoflurane and is still present after the emergence from sevoflurane anaesthesia suggests the presence of and necessitates a search for some putative substrate that may, by

  4. Swedish mutant APP-based BACE1 binding site peptide reduces APP β-cleavage and cerebral Aβ levels in Alzheimer's mice.

    Science.gov (United States)

    Li, Song; Hou, Huayan; Mori, Takashi; Sawmiller, Darrell; Smith, Adam; Tian, Jun; Wang, Yanjiang; Giunta, Brian; Sanberg, Paul R; Zhang, Sheqing; Tan, Jun

    2015-06-19

    BACE1 initiates amyloid-β (Aβ) generation and the resultant cerebral amyloidosis, as a characteristic of Alzheimer's disease (AD). Thus, inhibition of BACE1 has been the focus of a large body of research. The most recent clinical trials highlight the difficulty involved in this type of anti-AD therapy as evidenced by side effects likely due to the ubiquitous nature of BACE1, which cleaves multiple substrates. The human Swedish mutant form of amyloid protein precursor (APPswe) has been shown to possess a higher affinity for BACE1 compared to wild-type APP (APPwt). We pursued a new approach wherein harnessing this greater affinity to modulate BACE1 APP processing activity. We found that one peptide derived from APPswe, containing the β-cleavage site, strongly inhibits BACE1 activity and thereby reduces Aβ production. This peptide, termed APPswe BACE1 binding site peptide (APPsweBBP), was further conjugated to the fusion domain of the HIV-1 Tat protein (TAT) at the C-terminus to facilitate its biomembrane-penetrating activity. APPwt and APPswe over-expressing CHO cells treated with this TAT-conjugated peptide resulted in a marked reduction of Aβ and a significant increase of soluble APPα. Intraperitoneal administration of this peptide to 5XFAD mice markedly reduced β-amyloid deposits as well as improved hippocampal-dependent learning and memory.

  5. An Exon-Specific U1snRNA Induces a Robust Factor IX Activity in Mice Expressing Multiple Human FIX Splicing Mutants

    Directory of Open Access Journals (Sweden)

    Dario Balestra

    2016-01-01

    Full Text Available In cellular models we have demonstrated that a unique U1snRNA targeting an intronic region downstream of a defective exon (Exon-specific U1snRNA, ExSpeU1 can rescue multiple exon-skipping mutations, a relevant cause of genetic disease. Here, we explored in mice the ExSpeU1 U1fix9 toward two model Hemophilia B-causing mutations at the 5′ (c.519A > G or 3′ (c.392-8T > G splice sites of F9 exon 5. Hydrodynamic injection of wt-BALB/C mice with plasmids expressing the wt and mutant (hFIX-2G5′ss and hFIX-8G3′ss splicing-competent human factor IX (hFIX cassettes resulted in the expression of hFIX transcripts lacking exon 5 in liver, and in low plasma levels of inactive hFIX. Coinjection of U1fix9, but not of U1wt, restored exon inclusion of variants and in the intrinsically weak FIXwt context. This resulted in appreciable circulating hFIX levels (mean ± SD; hFIX-2G5′ss, 1.0 ± 0.5 µg/ml; hFIX-8G3′ss, 1.2 ± 0.3 µg/ml; and hFIXwt, 1.9 ± 0.6 µg/ml, leading to a striking shortening (from ≃100 seconds of untreated mice to ≃80 seconds of FIX-dependent coagulation times, indicating a hFIX with normal specific activity. This is the first proof-of-concept in vivo that a unique ExSpeU1 can efficiently rescue gene expression impaired by distinct exon-skipping variants, which extends the applicability of ExSpeU1s to panels of mutations and thus cohort of patients.

  6. Phosphorylation-triggered CUEDC2 degradation promotes UV-induced G1 arrest through APC/C(Cdh1) regulation.

    Science.gov (United States)

    Zhang, Wei-Na; Zhou, Jie; Zhou, Tao; Li, Ai-Ling; Wang, Na; Xu, Jin-Jing; Chang, Yan; Man, Jiang-Hong; Pan, Xin; Li, Tao; Li, Wei-Hua; Mu, Rui; Liang, Bing; Chen, Liang; Jin, Bao-Feng; Xia, Qing; Gong, Wei-Li; Zhang, Xue-Min; Wang, Li; Li, Hui-Yan

    2013-07-02

    DNA damage triggers cell cycle arrest to provide a time window for DNA repair. Failure of arrest could lead to genomic instability and tumorigenesis. DNA damage-induced G1 arrest is generally achieved by the accumulation of Cyclin-dependent kinase inhibitor 1 (p21). However, p21 is degraded and does not play a role in UV-induced G1 arrest. The mechanism of UV-induced G1 arrest thus remains elusive. Here, we have identified a critical role for CUE domain-containing protein 2 (CUEDC2) in this process. CUEDC2 binds to and inhibits anaphase-promoting complex/cyclosome-Cdh1 (APC/C(Cdh1)), a critical ubiquitin ligase in G1 phase, thereby stabilizing Cyclin A and promoting G1-S transition. In response to UV irradiation, CUEDC2 undergoes ERK1/2-dependent phosphorylation and ubiquitin-dependent degradation, leading to APC/C(Cdh1)-mediated Cyclin A destruction, Cyclin-dependent kinase 2 inactivation, and G1 arrest. A nonphosphorylatable CUEDC2 mutant is resistant to UV-induced degradation. Expression of this stable mutant effectively overrides UV-induced G1-S block. These results establish CUEDC2 as an APC/C(Cdh1) inhibitor and indicate that regulated CUEDC2 degradation is critical for UV-induced G1 arrest.

  7. Functional comparison of human adenomatous polyposis coli (APC and APC-like in targeting beta-catenin for degradation.

    Directory of Open Access Journals (Sweden)

    Jean Schneikert

    Full Text Available Truncating mutations affect the adenomatous polyposis coli (APC gene in most cases of colon cancer, resulting in the stabilization of β-catenin and uncontrolled cell proliferation. We show here that colon cancer cell lines express also the paralog APC-like (APCL or APC2. RNA interference revealed that it controls the level and/or the activity of β-catenin, but it is less efficient and binds less well to β-catenin than APC, thereby providing one explanation as to why the gene is not mutated in colon cancer. A further comparison indicates that APCL down-regulates the β-catenin level despite the lack of the 15R region known to be important in APC. To understand this discrepancy, we performed immunoprecipitation experiments that revealed that phosphorylated β-catenin displays a preference for binding to the 15 amino acid repeats (15R rather than the first 20 amino acid repeat of APC. This suggests that the 15R region constitutes a gate connecting the steps of β-catenin phosphorylation and subsequent ubiquitination/degradation. Using RNA interference and domain swapping experiments, we show that APCL benefits from the 15R of truncated APC to target β-catenin for degradation, in a process likely involving heterodimerization of the two partners. Our data suggest that the functional complementation of APCL by APC constitutes a substantial facet of tumour development, because the truncating mutations of APC in colorectal tumours from familial adenomatous polyposis (FAP patients are almost always selected for the retention of at least one 15R.

  8. 42 CFR 419.31 - Ambulatory payment classification (APC) system and payment weights.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false Ambulatory payment classification (APC) system and... Outpatient Services § 419.31 Ambulatory payment classification (APC) system and payment weights. (a) APC... the Federal Food, Drug and Cosmetic Act. (3) The payment rate determined for an APC group...

  9. Tumour Suppressor Adenomatous Polyposis Coli (APC) localisation is regulated by both Kinesin-1 and Kinesin-2

    Science.gov (United States)

    Ruane, Peter T.; Gumy, Laura F.; Bola, Becky; Anderson, Beverley; Wozniak, Marcin J.; Hoogenraad, Casper C.; Allan, Victoria J.

    2016-01-01

    Microtubules and their associated proteins (MAPs) underpin the polarity of specialised cells. Adenomatous polyposis coli (APC) is one such MAP with a multifunctional agenda that requires precise intracellular localisations. Although APC has been found to associate with kinesin-2 subfamily members, the exact mechanism for the peripheral localization of APC remains unclear. Here we show that the heavy chain of kinesin-1 directly interacts with the APC C-terminus, contributing to the peripheral localisation of APC in fibroblasts. In rat hippocampal neurons the kinesin-1 binding domain of APC is required for its axon tip enrichment. Moreover, we demonstrate that APC requires interactions with both kinesin-2 and kinesin-1 for this localisation. Underlining the importance of the kinesin-1 association, neurons expressing APC lacking kinesin-1-binding domain have shorter axons. The identification of this novel kinesin-1-APC interaction highlights the complexity and significance of APC localisation in neurons. PMID:27272132

  10. OpenAPC. Open-Access-Publikationskosten als Open Data

    OpenAIRE

    Tullney, Marco

    2015-01-01

    Präsentationsfolien zum Vortrag „OpenAPC. Open-Access-Publikationskosten als Open Data“ in der Session „Ausgestaltung eines wissenschaftsadäquaten APC-Marktes: Grundsätze, Finanzierungsansätze und Management“ der Open-Access-Tage 2015 in Zürich (https://www.open-access.net/community/open-access-tage/open-access-tage-2015-zuerich/programm/#c1974)

  11. The APC/C in female mammalian meiosis I.

    Science.gov (United States)

    Homer, Hayden

    2013-08-01

    The anaphase-promoting complex or cyclosome (APC/C) orchestrates a meticulously controlled sequence of proteolytic events critical for proper cell cycle progression, the details of which have been most extensively elucidated during mitosis. It has become apparent, however, that the APC/C, particularly when acting in concert with its Cdh1 co-activator (APC/C(Cdh1)), executes a staggeringly diverse repertoire of functions that extend its remit well outside the bounds of mitosis. Findings over the past decade have not only earmarked mammalian oocyte maturation as one such case in point but have also begun to reveal a complex pattern of APC/C regulation that underpins many of the oocyte's unique developmental attributes. This review will encompass the latest findings pertinent to the APC/C, especially APC/C(Cdh1), in mammalian oocytes and how its activity and substrates shape the stop-start tempo of female mammalian first meiotic division and the challenging requirement for assembling spindles in the absence of centrosomes.

  12. miR-155 Controls Lymphoproliferation in LAT Mutant Mice by Restraining T-Cell Apoptosis via SHIP-1/mTOR and PAK1/FOXO3/BIM Pathways.

    Directory of Open Access Journals (Sweden)

    Alexandre K Rouquette-Jazdanian

    Full Text Available Linker for Activation of T cells (LAT is an adapter protein that is essential for T cell function. Knock-in mice with a LAT mutation impairing calcium flux develop a fatal CD4+ lymphoproliferative disease. miR-155 is a microRNA that is correlated with hyperproliferation in a number of cancers including lymphomas and leukemias and is overexpressed in mutant LAT T cells. To test whether miR-155 was merely indicative of T cell activation or whether it contributes to lymphoproliferative disease in mutant LAT mice, we interbred LAT mutant and miR-155-deficient mice. miR-155 deficiency markedly inhibited lymphoproliferative disease by stimulating BIM-dependent CD4+ T cell apoptosis, even though ERK activation and T cell proliferation were increased in double mutant CD4+ T cells. Bim/Bcl2l11 expression is activated by the forkhead transcription factor FOXO3. Using miR-155-deficient, LAT mutant T cells as a discovery tool, we found two connected pathways that impact the nuclear translocation and activation of FOXO3 in T cells. One pathway is mediated by the inositide phosphatase SHIP-1 and the serine/threonine kinases AKT and PDK1. The other pathway involves PAK1 and JNK kinase activation. We define crosstalk between the two pathways via the kinase mTOR, which stabilizes PAK1. This study establishes a role for PAK1 in T cell apoptosis, which contrasts to its previously identified role in T cell proliferation. Furthermore, miR-155 regulates the delicate balance between PAK1-mediated proliferation and apoptosis in T cells impacting lymphoid organ size and function.

  13. Differential RNA-seq analysis comparing APC-defective and APC-restored SW480 colorectal cancer cells.

    Science.gov (United States)

    King, Lauren E; Love, Christopher G; Sieber, Oliver M; Faux, Maree C; Burgess, Antony W

    2016-03-01

    The adenomatous polyposis coli (APC) tumour suppressor gene is mutated in about 80% of colorectal cancers (CRC) Brannon et al. (2014) [1]. APC is a large multifunctional protein that regulates many biological functions including Wnt signalling (through the regulation of beta-catenin stability) Reya and Clevers (2005) [2], cell migration Kroboth et al. (2007), Sansom et al. (2004) [3], [4], mitosis Kaplan et al. (2001) [5], cell adhesion Faux et al. (2004), Carothers et al. (2001) [6], [7] and differentiation Sansom et al. (2004) [4]. Although the role of APC in CRC is often described as the deregulation of Wnt signalling, its other biological functions suggest that there are other factors at play that contribute to the onset of adenomas and the progression of CRC upon the truncation of APC. To identify genes and pathways that are dysregulated as a consequence of loss of function of APC, we compared the gene expression profiles of the APC mutated human CRC cell line SW480 following reintroduction of wild-type APC (SW480 + APC) or empty control vector (SW480 + vector control) Faux et al. (2004) . Here we describe the RNA-seq data derived for three biological replicates of parental SW480, SW480 + vector control and SW480 + APC cells, and present the bioinformatics pipeline used to test for differential gene expression and pathway enrichment analysis. A total of 1735 genes showed significant differential expression when APC was restored and were enriched for genes associated with cell polarity, Wnt signalling and the epithelial to mesenchymal transition. There was additional enrichment for genes involved in cell-cell adhesion, cell-matrix junctions, angiogenesis, axon morphogenesis and cell movement. The raw and analysed RNA-seq data have been deposited in the Gene Expression Omnibus (GEO) database under accession number GSE76307. This dataset is useful for further investigations of the impact of APC mutation on the properties of colorectal cancer cells.

  14. Differential RNA-seq analysis comparing APC-defective and APC-restored SW480 colorectal cancer cells

    Directory of Open Access Journals (Sweden)

    Lauren E. King

    2016-03-01

    Full Text Available The adenomatous polyposis coli (APC tumour suppressor gene is mutated in about 80% of colorectal cancers (CRC Brannon et al. (2014 [1]. APC is a large multifunctional protein that regulates many biological functions including Wnt signalling (through the regulation of beta-catenin stability Reya and Clevers (2005 [2], cell migration Kroboth et al. (2007, Sansom et al. (2004 [3,4], mitosis Kaplan et al. (2001 [5], cell adhesion Faux et al. (2004, Carothers et al. (2001 [6,7] and differentiation Sansom et al. (2004 [4]. Although the role of APC in CRC is often described as the deregulation of Wnt signalling, its other biological functions suggest that there are other factors at play that contribute to the onset of adenomas and the progression of CRC upon the truncation of APC. To identify genes and pathways that are dysregulated as a consequence of loss of function of APC, we compared the gene expression profiles of the APC mutated human CRC cell line SW480 following reintroduction of wild-type APC (SW480 + APC or empty control vector (SW480 + vector control Faux et al. (2004 . Here we describe the RNA-seq data derived for three biological replicates of parental SW480, SW480 + vector control and SW480 + APC cells, and present the bioinformatics pipeline used to test for differential gene expression and pathway enrichment analysis. A total of 1735 genes showed significant differential expression when APC was restored and were enriched for genes associated with cell polarity, Wnt signalling and the epithelial to mesenchymal transition. There was additional enrichment for genes involved in cell–cell adhesion, cell–matrix junctions, angiogenesis, axon morphogenesis and cell movement. The raw and analysed RNA-seq data have been deposited in the Gene Expression Omnibus (GEO database under accession number GSE76307. This dataset is useful for further investigations of the impact of APC mutation on the properties of colorectal cancer cells.

  15. Differential RNA-seq analysis comparing APC-defective and APC-restored SW480 colorectal cancer cells

    OpenAIRE

    King, Lauren E.; Love, Christopher G.; Sieber, Oliver M.; Faux, Maree C.; Antony W Burgess

    2016-01-01

    The adenomatous polyposis coli (APC) tumour suppressor gene is mutated in about 80% of colorectal cancers (CRC) Brannon et al. (2014) [1]. APC is a large multifunctional protein that regulates many biological functions including Wnt signalling (through the regulation of beta-catenin stability) Reya and Clevers (2005) [2], cell migration Kroboth et al. (2007), Sansom et al. (2004) [3], [4], mitosis Kaplan et al. (2001) [5], cell adhesion Faux et al. (2004), Carothers et al. (2001) [6], [7] and...

  16. Progressive Purkinje cell degeneration in tambaleante mutant mice is a consequence of a missense mutation in HERC1 E3 ubiquitin ligase.

    Directory of Open Access Journals (Sweden)

    Tomoji Mashimo

    2009-12-01

    Full Text Available The HERC gene family encodes proteins with two characteristic domains: HECT and RCC1-like. Proteins with HECT domains have been described to function as ubiquitin ligases, and those that contain RCC1-like domains have been reported to function as GTPases regulators. These two activities are essential in a number of important cellular processes such as cell cycle, cell signaling, and membrane trafficking. Mutations affecting these domains have been found associated with retinitis pigmentosa, amyotrophic lateral sclerosis, and cancer. In humans, six HERC genes have been reported which encode two subgroups of HERC proteins: large (HERC1-2 and small (HERC3-6. The giant HERC1 protein was the first to be identified. It has been involved in membrane trafficking and cell proliferation/growth through its interactions with clathrin, M2-pyruvate kinase, and TSC2 proteins. Mutations affecting other members of the HERC family have been found to be associated with sterility and growth retardation. Here, we report the characterization of a recessive mutation named tambaleante, which causes progressive Purkinje cell degeneration leading to severe ataxia with reduced growth and lifespan in homozygous mice aged over two months. We mapped this mutation in mouse chromosome 9 and then performed positional cloning. We found a GA transition at position 1448, causing a Gly to Glu substitution (Gly483Glu in the highly conserved N-terminal RCC1-like domain of the HERC1 protein. Successful transgenic rescue, with either a mouse BAC containing the normal copy of Herc1 or with the human HERC1 cDNA, validated our findings. Histological and biochemical studies revealed extensive autophagy associated with an increase of the mutant protein level and a decrease of mTOR activity. Our observations concerning this first mutation in the Herc1 gene contribute to the functional annotation of the encoded E3 ubiquitin ligase and underline the crucial and unexpected role of this protein

  17. The polyglutamine-expanded androgen receptor responsible for spinal and bulbar muscular atrophy inhibits the APC/C(Cdh1) ubiquitin ligase complex.

    Science.gov (United States)

    Bott, Laura C; Salomons, Florian A; Maric, Dragan; Liu, Yuhong; Merry, Diane; Fischbeck, Kenneth H; Dantuma, Nico P

    2016-06-17

    Polyglutamine expansion in the androgen receptor (AR) causes spinal and bulbar muscular atrophy (SBMA), an X-linked neuromuscular disease that is fully manifest only in males. It has been suggested that proteins with expanded polyglutamine tracts impair ubiquitin-dependent proteolysis due to their propensity to aggregate, but recent studies indicate that the overall activity of the ubiquitin-proteasome system is preserved in SBMA models. Here we report that AR selectively interferes with the function of the ubiquitin ligase anaphase-promoting complex/cyclosome (APC/C), which, together with its substrate adaptor Cdh1, is critical for cell cycle arrest and neuronal architecture. We show that both wild-type and mutant AR physically interact with the APC/C(Cdh1) complex in a ligand-dependent fashion without being targeted for proteasomal degradation. Inhibition of APC/C(Cdh1) by mutant but not wild-type AR in PC12 cells results in enhanced neurite outgrowth which is typically followed by rapid neurite retraction and mitotic entry. Our data indicate a role of AR in neuronal differentiation through regulation of APC/C(Cdh1) and suggest abnormal cell cycle reactivation as a pathogenic mechanism in SBMA.

  18. The polyglutamine-expanded androgen receptor responsible for spinal and bulbar muscular atrophy inhibits the APC/CCdh1 ubiquitin ligase complex

    Science.gov (United States)

    Bott, Laura C.; Salomons, Florian A.; Maric, Dragan; Liu, Yuhong; Merry, Diane; Fischbeck, Kenneth H.; Dantuma, Nico P.

    2016-01-01

    Polyglutamine expansion in the androgen receptor (AR) causes spinal and bulbar muscular atrophy (SBMA), an X-linked neuromuscular disease that is fully manifest only in males. It has been suggested that proteins with expanded polyglutamine tracts impair ubiquitin-dependent proteolysis due to their propensity to aggregate, but recent studies indicate that the overall activity of the ubiquitin-proteasome system is preserved in SBMA models. Here we report that AR selectively interferes with the function of the ubiquitin ligase anaphase-promoting complex/cyclosome (APC/C), which, together with its substrate adaptor Cdh1, is critical for cell cycle arrest and neuronal architecture. We show that both wild-type and mutant AR physically interact with the APC/CCdh1 complex in a ligand-dependent fashion without being targeted for proteasomal degradation. Inhibition of APC/CCdh1 by mutant but not wild-type AR in PC12 cells results in enhanced neurite outgrowth which is typically followed by rapid neurite retraction and mitotic entry. Our data indicate a role of AR in neuronal differentiation through regulation of APC/CCdh1 and suggest abnormal cell cycle reactivation as a pathogenic mechanism in SBMA. PMID:27312068

  19. Identification of an APC Variant in a Patient with Clinical Attenuated Familial Adenomatous Polyposis

    Directory of Open Access Journals (Sweden)

    Andrew T. Schlussel

    2014-01-01

    Full Text Available Introduction. The objective of this case report is to discuss an unclassified germline variant of the adenomatous polyposis coli (APC gene identified in an older patient with attenuated familial adenomatous polyposis syndrome (AFAP. Methods. We present a case report of a 66-year-old man diagnosed with AFAP. Colonoscopy found multiple polyps and invasive adenocarcinoma arising in the transverse colon. Samples were tested for mutations in the APC gene. Results. DNA sequencing of germline DNA identified a cytosine (C to thymine (T transition at nucleotide 1240, heterozygous. The C to T transition at codon 414 is predicted to convert an arginine residue to a cysteine that is possibly pathogenic. Analysis of the patient’s colon tumor DNA indicated that the tumor had lost the mutant variant allele and retained only the normal allele, suggesting that the variant may not be significant. Conclusions. The p.R414C variant has been described previously as a germline mutation of probable pathogenicity. This substitution should be considered an unclassified variant and possibly not pathogenic. These findings support the need for further genetic testing of tissue, as well as for developing a mechanism for testing all variants, as this could significantly impact the lives of patients and their family members.

  20. Brucella abortus mutants lacking ATP-binding cassette transporter proteins are highly attenuated in virulence and confer protective immunity against virulent B. abortus challenge in BALB/c mice.

    Science.gov (United States)

    Truong, Quang Lam; Cho, Youngjae; Park, Soyeon; Park, Bo-Kyoung; Hahn, Tae-Wook

    2016-06-01

    Brucella abortus RB51 is an attenuated vaccine strain that has been most frequently used for bovine brucellosis. Although it is known to provide good protection in cattle, it still has some drawbacks including resistance to rifampicin, residual virulence and pathogenicity in humans. Thus, there has been a continuous interest on new safe and effective bovine vaccine candidates. In the present study, we have constructed unmarked mutants by deleting singly cydD and cydC genes, which encode ATP-binding cassette transporter proteins, from the chromosome of the virulent Brucella abortus isolate from Korean cow (referred to as IVK15). Both IVK15ΔcydD and ΔcydC mutants showed increased sensitivity to metal ions, hydrogen peroxide and acidic pH, which are mimic to intracellular environment during host infection. Additionally, the mutants exhibited a significant growth defect in RAW264.7 cells and greatly attenuated in mice. Vaccination of mice with either IVK15ΔcydC or IVK15ΔcydD mutant could elicit an anti-Brucella specific immunoglobulin G (IgG) and IgG subclass responses as well as enhance the secretion of interferon-gamma, and provided better protection against challenge with B. abortus strain 2308 than with the commercial B. abortus strain RB51 vaccine. Collectively, these results suggest that both IVK15ΔcydC and IVK15ΔcydD mutants could be an attenuated vaccine candidate against B. abortus.

  1. Chronic epithelial NF-κB activation accelerates APC loss and intestinal tumor initiation through iNOS up-regulation

    OpenAIRE

    Shaked, Helena; Hofseth, Lorne J.; Chumanevich, Alena; Chumanevich, Alexander A.; Wang, Jin; Wang, Yinsheng; Taniguchi, Koji; Guma, Monica; Shenouda, Steve; Clevers, Hans; Curtis C Harris; Karin, Michael

    2012-01-01

    The role of NF-κB activation in tumor initiation has not been thoroughly investigated. We generated Ikkβ(EE)IEC transgenic mice expressing constitutively active IκB kinase β (IKKβ) in intestinal epithelial cells (IECs). Despite absence of destructive colonic inflammation, Ikkβ(EE)IEC mice developed intestinal tumors after a long latency. However, when crossed to mice with IEC-specific allelic deletion of the adenomatous polyposis coli (Apc) tumor suppressor locus, Ikkβ(EE)IEC mice exhibited m...

  2. High performance APCS conceptual design and evaluation scoping study

    Energy Technology Data Exchange (ETDEWEB)

    Soelberg, N.; Liekhus, K.; Chambers, A.; Anderson, G.

    1998-02-01

    This Air Pollution Control System (APCS) Conceptual Design and Evaluation study was conducted to evaluate a high-performance (APC) system for minimizing air emissions from mixed waste thermal treatment systems. Seven variations of high-performance APCS designs were conceptualized using several design objectives. One of the system designs was selected for detailed process simulation using ASPEN PLUS to determine material and energy balances and evaluate performance. Installed system capital costs were also estimated. Sensitivity studies were conducted to evaluate the incremental cost and benefit of added carbon adsorber beds for mercury control, specific catalytic reduction for NO{sub x} control, and offgas retention tanks for holding the offgas until sample analysis is conducted to verify that the offgas meets emission limits. Results show that the high-performance dry-wet APCS can easily meet all expected emission limits except for possibly mercury. The capability to achieve high levels of mercury control (potentially necessary for thermally treating some DOE mixed streams) could not be validated using current performance data for mercury control technologies. The engineering approach and ASPEN PLUS modeling tool developed and used in this study identified APC equipment and system performance, size, cost, and other issues that are not yet resolved. These issues need to be addressed in feasibility studies and conceptual designs for new facilities or for determining how to modify existing facilities to meet expected emission limits. The ASPEN PLUS process simulation with current and refined input assumptions and calculations can be used to provide system performance information for decision-making, identifying best options, estimating costs, reducing the potential for emission violations, providing information needed for waste flow analysis, incorporating new APCS technologies in existing designs, or performing facility design and permitting activities.

  3. Regulated degradation of the APC coactivator Cdc20

    Directory of Open Access Journals (Sweden)

    Robbins Jonathan A

    2010-09-01

    Full Text Available Abstract Background Cdc20 is a highly conserved activator of the anaphase-promoting complex (APC, promoting cell-cycle-regulated ubiquitination and proteolysis of a number of critical cell-cycle-regulatory targets including securin and mitotic cyclins. APC-Cdc20 activity is tightly regulated, and this regulation is likely important for accurate cell cycle control. One significant component of Cdc20 regulation is thought to be Cdc20 proteolysis. However, published literature suggests different mechanisms and requirements for Cdc20 proteolysis. The degree to which Cdc20 proteolysis is cell-cycle regulated, the dependence of Cdc20 proteolysis on Cdc20 destruction boxes (recognition sequences for APC-mediated ubiqutination, either by Cdc20 or by the related Cdh1 APC activator, and the need for APC itself for Cdc20 proteolysis all have been disputed to varying extents. In animals, Cdc20 proteolysis is thought to be mediated by Cdh1, contributing an intrinsic order of APC activation by Cdc20 and then by Cdh1. One report suggests a Cdh1 requirement for Cdc20 proteolysis in budding yeast; this idea has not been tested further. Results We characterized Cdc20 proteolysis using Cdc20 expressed from its endogenous locus; previous studies generally employed strongly overexpressed Cdc20, which can cause significant artifacts. We analyzed Cdc20 proteolysis with or without mutations in previously identified destruction box sequences, using varying methods of cell cycle synchronization, and in the presence or absence of Cdh1. Cdc20 instability is only partially dependent on destruction boxes. A much stronger dependence on Cdh1 for Cdc20 proteolysis was observed, but Cdh1-independent proteolysis was also clearly observed. Cdc20 proteolysis independent of both destruction boxes and Cdh1 was especially detectable around the G1/S transition; Cdh1-dependent proteolysis was most notable in late mitosis and G1. Conclusions Cdc20 proteolysis is under complex control

  4. ApcD is necessary for efficient energy transfer from phycobilisomes to photosystem I and helps to prevent photoinhibition in the cyanobacterium Synechococcus sp. PCC 7002.

    Science.gov (United States)

    Dong, Chunxia; Tang, Aihui; Zhao, Jindong; Mullineaux, Conrad W; Shen, Gaozhong; Bryant, Donald A

    2009-09-01

    Phycobilisomes (PBS) are the major light-harvesting, protein-pigment complexes in cyanobacteria and red algae. PBS absorb and transfer light energy to photosystem (PS) II as well as PS I, and the distribution of light energy from PBS to the two photosystems is regulated by light conditions through a mechanism known as state transitions. In this study the quantum efficiency of excitation energy transfer from PBS to PS I in the cyanobacterium Synechococcus sp. PCC 7002 was determined, and the results showed that energy transfer from PBS to PS I is extremely efficient. The results further demonstrated that energy transfer from PBS to PS I occurred directly and that efficient energy transfer was dependent upon the allophycocyanin-B alpha subunit, ApcD. In the absence of ApcD, cells were unable to perform state transitions and were trapped in state 1. Action spectra showed that light energy transfer from PBS to PS I was severely impaired in the absence of ApcD. An apcD mutant grew more slowly than the wild type in light preferentially absorbed by phycobiliproteins and was more sensitive to high light intensity. On the other hand, a mutant lacking ApcF, which is required for efficient energy transfer from PBS to PS II, showed greater resistance to high light treatment. Therefore, state transitions in cyanobacteria have two roles: (1) they regulate light energy distribution between the two photosystems; and (2) they help to protect cells from the effects of light energy excess at high light intensities.

  5. Epigenetic regulation of APC in the molecular pathogenesis of gallbladder cancer

    Directory of Open Access Journals (Sweden)

    Dinesh Singh Tekcham

    2016-01-01

    Interpretation & conclusions: The present findings indicate epigenetic silencing of APC in advanced GBC. The methylation pattern, followed by expression analysis of APC may be suggested for diagnostic, prognostic and therapeutic purposes in GBC in future.

  6. Apc Restoration Promotes Cellular Differentiation and Reestablishes Crypt Homeostasis in Colorectal Cancer

    NARCIS (Netherlands)

    Dow, Lukas E; O'Rourke, Kevin P; Simon, Janelle; Tschaharganeh, Darjus F; van Es, Johan H; Clevers, Hans; Lowe, Scott W

    2015-01-01

    The adenomatous polyposis coli (APC) tumor suppressor is mutated in the vast majority of human colorectal cancers (CRC) and leads to deregulated Wnt signaling. To determine whether Apc disruption is required for tumor maintenance, we developed a mouse model of CRC whereby Apc can be conditionally su

  7. Occult progression by Apc-deficient intestinal crypts as a target for chemoprevention

    NARCIS (Netherlands)

    Fischer, Jared M; Schepers, Arnout G; Clevers, Hans; Shibata, Darryl; Liskay, R Michael

    2014-01-01

    Although Apc mutation is widely considered an initiating event in colorectal cancer, little is known about the earliest stages of tumorigenesis following sporadic Apc loss. Therefore, we have utilized a novel mouse model that facilitates the sporadic inactivation of Apc via frameshift reversion of C

  8. Stabilization of APC residues from waste incineration with ferrous sulfate on a semi-industrial scale

    DEFF Research Database (Denmark)

    Lundtorp, Kasper; Jensen, Dorthe Lærke; Christensen, Thomas Højlund

    2002-01-01

    A stabilization method for air pollution control (APC) residues from municipal solid waste incineration (MSWI) involving mixing of the residue with water and FeSO4 has been demonstrated on a semi-industrial scale on three types of APC residues: a semidy (SD) APC residue, a fly ash (FA), and an FA...

  9. ACKR4 on Stromal Cells Scavenges CCL19 To Enable CCR7-Dependent Trafficking of APCs from Inflamed Skin to Lymph Nodes.

    Science.gov (United States)

    Bryce, Steven A; Wilson, Ruairi A M; Tiplady, Eleanor M; Asquith, Darren L; Bromley, Shannon K; Luster, Andrew D; Graham, Gerard J; Nibbs, Robert J B

    2016-04-15

    Dermal dendritic cells and epidermal Langerhans cells are APCs that migrate from skin to draining lymph nodes (LN) to drive peripheral tolerance and adaptive immunity. Their migration requires the chemokine receptor CCR7, which directs egress from the skin via dermal lymphatic vessels and extravasation into the LN parenchyma from lymph in the subcapsular sinus. CCR7 is activated by two chemokines: CCL19 and CCL21. CCL21 alone is sufficient for the migration of APCs from skin to LN. CCL19 and CCL21 also bind atypical chemokine receptor (ACKR) 4. ACKR4-mediated CCL21 scavenging by lymphatic endothelial cells lining the subcapsular sinus ceiling stabilizes interfollicular CCL21 gradients that direct lymph-borne CCR7(+)APCs into the parenchyma of mouse LN. In this study, we show that ACKR4 also aids APC egress from mouse skin under steady-state and inflammatory conditions. ACKR4 plays a particularly prominent role during cutaneous inflammation when it facilitates Langerhans cell egress from skin and enables the accumulation of dermal dendritic cells in skin-draining LN. Stromal cells in mouse skin, predominantly keratinocytes and a subset of dermal lymphatic endothelial cells, express ACKR4 and are capable of ACKR4-dependent chemokine scavenging in situ. ACKR4-mediated scavenging of dermal-derived CCL19, rather than CCL21, is critical during inflammation, because the aberrant trafficking of skin-derived APCs inAckr4-deficient mice is completely rescued by genetic deletion ofCcl19 Thus, ACKR4 on stromal cells aids the egress of APCs from mouse skin, and, during inflammation, facilitates CCR7-dependent cell trafficking by scavenging CCL19.

  10. Social approach behaviors are similar on conventional versus reverse lighting cycles, and in replications across cohorts, in BTBR T+ tf/J, C57BL/6J, and vasopressin receptor 1B mutant mice

    Directory of Open Access Journals (Sweden)

    Mu Yang

    2007-11-01

    Full Text Available Mice are a nocturnal species, whose social behaviors occur primarily during the dark phase of the circadian cycle. However, laboratory rodents are frequently tested during their light phase, for practical reasons. We investigated the question of whether light phase testing presents a methodological pitfall for investigating mouse social approach behaviors. Three lines of mice were systematically compared. One cohort of each line was raised in a conventional lighting schedule and tested during the light phase, under white light illumination; another cohort was raised in a reverse lighting schedule and tested during their dark phase, under dim red light. Male C57BL/6J (B6 displayed high levels of sociability in our three-chambered automated social approach task when tested in either phase. BTBR T+ tf/J (BTBR displayed low levels of sociability in either phase. Five cohorts of vasopressin receptor subtype 1b (Avpr1b null mutants, heterozygotes, and wildtype littermate controls were tested in the same social approach paradigm: three in the dark phase and two in the light phase. All three genotypes displayed normal sociability in four out of the five replications. In the juvenile play test, testing phase had no effect on play soliciting behaviors in Avpr1b mice, but had modest effects on nose sniff and huddling. Taken together, these findings indicate that testing phase is not a crucial factor for studying some forms of social approach in juvenile and adult mice.

  11. No dopamine cell loss or changes in cytoskeleton function in transgenic mice expressing physiological levels of wild type or G2019S mutant LRRK2 and in human fibroblasts.

    Science.gov (United States)

    Garcia-Miralles, Marta; Coomaraswamy, Janaky; Häbig, Karina; Herzig, Martin C; Funk, Natalja; Gillardon, Frank; Maisel, Martina; Jucker, Mathias; Gasser, Thomas; Galter, Dagmar; Biskup, Saskia

    2015-01-01

    Mutations within the LRRK2 gene have been identified in Parkinson's disease (PD) patients and have been implicated in the dysfunction of several cellular pathways. Here, we explore how pathogenic mutations and the inhibition of LRRK2 kinase activity affect cytoskeleton dynamics in mouse and human cell systems. We generated and characterized a novel transgenic mouse model expressing physiological levels of human wild type and G2019S-mutant LRRK2. No neuronal loss or neurodegeneration was detected in midbrain dopamine neurons at the age of 12 months. Postnatal hippocampal neurons derived from transgenic mice showed no alterations in the seven parameters examined concerning neurite outgrowth sampled automatically on several hundred neurons using high content imaging. Treatment with the kinase inhibitor LRRK2-IN-1 resulted in no significant changes in the neurite outgrowth. In human fibroblasts we analyzed whether pathogenic LRRK2 mutations change cytoskeleton functions such as cell adhesion. To this end we compared the adhesion characteristics of human skin fibroblasts derived from six PD patients carrying one of three different pathogenic LRRK2 mutations and from four age-matched control individuals. The mutant LRRK2 variants as well as the inhibition of LRRK2 kinase activity did not reveal any significant cell adhesion differences in cultured fibroblasts. In summary, our results in both human and mouse cell systems suggest that neither the expression of wild type or mutant LRRK2, nor the inhibition of LRRK2 kinase activity affect neurite complexity and cellular adhesion.

  12. No dopamine cell loss or changes in cytoskeleton function in transgenic mice expressing physiological levels of wild type or G2019S mutant LRRK2 and in human fibroblasts.

    Directory of Open Access Journals (Sweden)

    Marta Garcia-Miralles

    Full Text Available Mutations within the LRRK2 gene have been identified in Parkinson's disease (PD patients and have been implicated in the dysfunction of several cellular pathways. Here, we explore how pathogenic mutations and the inhibition of LRRK2 kinase activity affect cytoskeleton dynamics in mouse and human cell systems. We generated and characterized a novel transgenic mouse model expressing physiological levels of human wild type and G2019S-mutant LRRK2. No neuronal loss or neurodegeneration was detected in midbrain dopamine neurons at the age of 12 months. Postnatal hippocampal neurons derived from transgenic mice showed no alterations in the seven parameters examined concerning neurite outgrowth sampled automatically on several hundred neurons using high content imaging. Treatment with the kinase inhibitor LRRK2-IN-1 resulted in no significant changes in the neurite outgrowth. In human fibroblasts we analyzed whether pathogenic LRRK2 mutations change cytoskeleton functions such as cell adhesion. To this end we compared the adhesion characteristics of human skin fibroblasts derived from six PD patients carrying one of three different pathogenic LRRK2 mutations and from four age-matched control individuals. The mutant LRRK2 variants as well as the inhibition of LRRK2 kinase activity did not reveal any significant cell adhesion differences in cultured fibroblasts. In summary, our results in both human and mouse cell systems suggest that neither the expression of wild type or mutant LRRK2, nor the inhibition of LRRK2 kinase activity affect neurite complexity and cellular adhesion.

  13. Clinicopathologic characteristics of anterior prostate cancer (APC), including correlation with previous biopsy pathology.

    Science.gov (United States)

    Magers, Martin J; Zhan, Tianyu; Udager, Aaron M; Wei, John T; Tomlins, Scott A; Wu, Angela J; Kunju, Lakshmi P; Lew, Madelyn; Feng, Felix Y; Hamstra, Daniel A; Siddiqui, Javed; Chinnaiyan, Arul M; Montgomery, Jeffrey S; Weizer, Alon Z; Morgan, Todd M; Hollenbeck, Brent K; Miller, David C; Palapattu, Ganesh S; Jiang, Hui; Mehra, Rohit

    2015-11-01

    Anterior-predominant prostate cancer (APC) is an incompletely understood entity which can be difficult to sample via transrectal biopsy. Seemingly favorable biopsy results may belie the potential aggressiveness of these tumors. Here, we attempt to characterize APC by retrospectively examining the clinicopathologic features of APC at radical prostatectomy and comparing our findings with prior biopsy information. We found that 17.4 % of patients in our study had APC. APC demonstrated a significantly lower (P value biopsy than non-transperineal saturation (i.e., transrectal ultrasound guided) biopsy strategies. Four patients (7 %) without transperineal saturation biopsy exhibited a significantly worse GS at RP than biopsy, compared to five patients (36 %) with transperineal saturation biopsy. Our findings corroborate the difficulty in detecting APC and suggest that APC is not a uniform disease with a wholly indolent phenotype. Dedicated long-term outcome data are needed in these patients. Additionally, alternative pathologic staging parameters may be necessary.

  14. Impaired long-term memory retention and working memory in sdy mutant mice with a deletion in Dtnbp1, a susceptibility gene for schizophrenia

    Directory of Open Access Journals (Sweden)

    Takao Keizo

    2008-10-01

    Full Text Available Abstract Background Schizophrenia is a complex genetic disorder caused by multiple genetic and environmental factors. The dystrobrevin-binding protein 1 (DTNBP1: dysbindin-1 gene is a major susceptibility gene for schizophrenia. Genetic variations in DTNBP1 are associated with cognitive functions, general cognitive ability and memory function, and clinical features of patients with schizophrenia including negative symptoms and cognitive decline. Since reduced expression of dysbindin-1 has been observed in postmortem brains of patients with schizophrenia, the sandy (sdy mouse, which has a deletion in the Dtnbp1 gene and expresses no dysbindin-1 protein, could be an animal model of schizophrenia. To address this issue, we have carried out a comprehensive behavioral analysis of the sdy mouse in this study. Results In a rotarod test, sdy mice did not exhibit motor learning whilst the wild type mice did. In a Barnes circular maze test both sdy mice and wild type mice learned to selectively locate the escape hole during the course of the training period and in the probe trial conducted 24 hours after last training. However, sdy mice did not locate the correct hole in the retention probe tests 7 days after the last training trial, whereas wild type mice did, indicating impaired long-term memory retention. A T-maze forced alternation task, a task of working memory, revealed no effect of training in sdy mice despite the obvious effect of training in wild type mice, suggesting a working memory deficit. Conclusion Sdy mouse showed impaired long-term memory retention and working memory. Since genetic variation in DTNBP1 is associated with both schizophrenia and memory function, and memory function is compromised in patients with schizophrenia, the sdy mouse may represent a useful animal model to investigate the mechanisms of memory dysfunction in the disorder.

  15. Mitochondria-targeted catalase reverts the neurotoxicity of hSOD1G⁹³A astrocytes without extending the survival of ALS-linked mutant hSOD1 mice.

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    Mariana Pehar

    Full Text Available Dominant mutations in the Cu/Zn-superoxide dismutase (SOD1 cause familial forms of amyotrophic lateral sclerosis (ALS, a fatal disorder characterized by the progressive loss of motor neurons. The molecular mechanism underlying the toxic gain-of-function of mutant hSOD1s remains uncertain. Several lines of evidence suggest that toxicity to motor neurons requires damage to non-neuronal cells. In line with this observation, primary astrocytes isolated from mutant hSOD1 over-expressing rodents induce motor neuron death in co-culture. Mitochondrial alterations have been documented in both neuronal and glial cells from ALS patients as well as in ALS-animal models. In addition, mitochondrial dysfunction and increased oxidative stress have been linked to the toxicity of mutant hSOD1 in astrocytes and neurons. In mutant SOD1-linked ALS, mitochondrial alterations may be partially due to the increased association of mutant SOD1 with the outer membrane and intermembrane space of the mitochondria, where it can affect several critical aspects of mitochondrial function. We have previously shown that decreasing glutathione levels, which is crucial for peroxide detoxification in the mitochondria, significantly accelerates motor neuron death in hSOD1G93A mice. Here we employed a catalase targeted to the mitochondria to investigate the effect of increased mitochondrial peroxide detoxification capacity in models of mutant hSOD1-mediated motor neuron death. The over-expression of mitochondria-targeted catalase improved mitochondrial antioxidant defenses and mitochondrial function in hSOD1G93A astrocyte cultures. It also reverted the toxicity of hSOD1G93A-expressing astrocytes towards co-cultured motor neurons, however ALS-animals did not develop the disease later or survive longer. Hence, while increased oxidative stress and mitochondrial dysfunction have been extensively documented in ALS, these results suggest that preventing peroxide-mediated mitochondrial damage

  16. Adaptive SPC monitoring scheme for DOE-based APC

    Institute of Scientific and Technical Information of China (English)

    Ye Liang; Pan Ershun; Xi Lifeng

    2008-01-01

    Automatic process control (APC) based on design of experiment (DOE) is a cost-efficient approach for variation reduction. The process changes both in mean and variance owing to online parameter adjustment make it hard to apply traditional SPC charts in such DOE-based APC applied process. An adaptive SPC scheme is developed, which can better track the process transitions and achieve the possible SPC run cost reduction when the process is stable. The control law of SPC parameters is designed by fully utilizing the estimation properties of the process model instead of traditionally using the data collected from the production line. An example is provided to illustrate the proposed adaptive SPC design approach.

  17. Cellular factors targeting APCs to modulate adaptive T cell immunity.

    Science.gov (United States)

    Visperas, Anabelle; Do, Jeongsu; Min, Booki

    2014-01-01

    The fate of adaptive T cell immunity is determined by multiple cellular and molecular factors, among which the cytokine milieu plays the most important role in this process. Depending on the cytokines present during the initial T cell activation, T cells become effector cells that produce different effector molecules and execute adaptive immune functions. Studies thus far have primarily focused on defining how these factors control T cell differentiation by targeting T cells themselves. However, other non-T cells, particularly APCs, also express receptors for the factors and are capable of responding to them. In this review, we will discuss how APCs, by responding to those cytokines, influence T cell differentiation and adaptive immunity.

  18. Cellular Factors Targeting APCs to Modulate Adaptive T Cell Immunity

    Directory of Open Access Journals (Sweden)

    Anabelle Visperas

    2014-01-01

    Full Text Available The fate of adaptive T cell immunity is determined by multiple cellular and molecular factors, among which the cytokine milieu plays the most important role in this process. Depending on the cytokines present during the initial T cell activation, T cells become effector cells that produce different effector molecules and execute adaptive immune functions. Studies thus far have primarily focused on defining how these factors control T cell differentiation by targeting T cells themselves. However, other non-T cells, particularly APCs, also express receptors for the factors and are capable of responding to them. In this review, we will discuss how APCs, by responding to those cytokines, influence T cell differentiation and adaptive immunity.

  19. Co-operating for gold open access without APCs

    Directory of Open Access Journals (Sweden)

    Martin Paul Eve

    2015-03-01

    Full Text Available While article processing charges (APCs are emerging as a key way in which existing publishers can adapt to gold open access (OA, this mode is problematic in many ways. Considering the existing subscription publication ecosystem as a risk/cost-pooling mechanism leads to the conclusion that APCs are a concentration of risk that may come with damaging institutional consequences, particularly in the humanities disciplines. Consortial and co-operative modes of funding gold OA, however, do not come with these drawbacks but are susceptible to ‘free riders’. In this article, the theoretical backdrop to these models is addressed and the range of current offerings evaluated. Noting that classical economic incentives do not seem to operate in a world of inter-library loans, the article ends with a description of the model that is being implemented for the 'Open Library of Humanities' initiative, funded by the Andrew W Mellon Foundation.

  20. Neurotoxicity of cGMP in the vertebrate retina: from the initial research on rd mutant mice to zebrafish genetic approaches.

    Science.gov (United States)

    Iribarne, Maria; Masai, Ichiro

    2017-09-01

    Zebrafish are an excellent animal model for research on vertebrate development and human diseases. Sophisticated genetic tools including large-scale mutagenesis methodology make zebrafish useful for studying neuronal degenerative diseases. Here, we review zebrafish models of inherited ophthalmic diseases, focusing on cGMP metabolism in photoreceptors. cGMP is the second messenger of phototransduction, and abnormal cGMP levels are associated with photoreceptor death. cGMP concentration represents a balance between cGMP phosphodiesterase 6 (PDE6) and guanylate cyclase (GC) activities in photoreceptors. Various zebrafish cGMP metabolism mutants were used to clarify molecular mechanisms by which dysfunctions in this pathway trigger photoreceptor degeneration. Here, we review the history of research on the retinal degeneration (rd) mutant mouse, which carries a genetic mutation of PDE6b, and we also highlight recent research in photoreceptor degeneration using zebrafish models. Several recent discoveries that provide insight into cGMP toxicity in photoreceptors are discussed.

  1. Extracellular Vesicles Containing P301L Mutant Tau Accelerate Pathological Tau Phosphorylation and Oligomer Formation but Do Not Seed Mature Neurofibrillary Tangles in ALZ17 Mice.

    Science.gov (United States)

    Baker, Siân; Polanco, Juan Carlos; Götz, Jϋrgen

    2016-10-04

    In Alzheimer's disease, the distribution of neurofibrillary tangles, a histological hallmark comprised of phosphorylated forms of the protein tau, follows a distinct pattern through anatomically connected brain regions. The well-documented correlation between the severity of tau pathology and disease progression implies a prion-like seeding and spreading mechanism for tau. Experimentally, this has been addressed in transgenic mice by the injection of protein lysates isolated from brains of transgenic mice or patients with tauopathies, including AD, that were shown to behave like seeds, accelerating tau pathology and tangle formation in predisposed mice. More specifically, in vivo data suggest that brain lysates from mice harboring the P301S mutation of tau can seed protein aggregation when injected into the hippocampi of human wild-type tau transgenic ALZ17 mice. Here, we compared the seeding potential of lysates and extracellular vesicles enriched for exosomes (EVs) from wild-type and human P301L tau transgenic rTg4510 mouse brains. We show that transgenic EVs cause increased tau phosphorylation and soluble oligomer formation in a manner comparable to that of freely available proteins in brain lysates, a prerequisite for the formation of mature protein aggregates.

  2. Clinical application of Assessment of Parenting Competencies (APC)

    DEFF Research Database (Denmark)

    Jacobsen, Stine Lindahl

    This paper is part of a symposium on music therapy with families with Kirsi Tuomi as Chair. It revolves around the clinical application of a new music therapy assessment model on parent-child interaction and parenting competencies. APC was developed for emotional neglected children and their pare......This paper is part of a symposium on music therapy with families with Kirsi Tuomi as Chair. It revolves around the clinical application of a new music therapy assessment model on parent-child interaction and parenting competencies. APC was developed for emotional neglected children......, child somatic hospitals, centers for refuges and other populations where it would be clinical relevant to assess the parent-child interaction. APC is an observational and improvisational based assessment model evaluating dyads of parent and child (child age range is 5-12). It produces information...... (numbers, graphs, and descriptions) of parent-child interaction and parenting competencies including nonverbal communication, level of attunement in the dyad, and level of emotional support from the parent. It is based on video analysis and a fixed assessment protocol. It was developed through a completed...

  3. Human immunodeficiencies related to APC/T cell interaction

    Directory of Open Access Journals (Sweden)

    Marinos eKallikourdis

    2015-08-01

    Full Text Available The primary event for initiating adaptive immune responses is the encounter between T lymphocytes and antigen presenting cells (APC in the T cell area of secondary lymphoid organs and the formation of highly organized inter-cellular junctions referred to as the immune synapses. In vivo live-cell imaging of APC-T cell interactions combined to functional studies unveiled that T cell fate is dictated, in large part, by the stability of the initial contact. Immune cell interaction is equally important during delivery of T cell help to B cells and for the killing of target cells by cytotoxic T cells and NK cells. The critical role of contact dynamics and synapse stability on the immune response is well illustrated by human immune deficiencies in which disease pathogenesis is linked to altered adhesion or defective cross-talk between the synaptic partners. Here we will discuss in details the mechanisms of defective APC-T cell communications in Wiskott-Aldrich syndrome (WAS and in warts, hypogammaglobulinemia, infections, myelokathexis syndrome (WHIM. In addition, we will summarize the evidences pointing to a compromised conjugate formation in WIP deficiency, DOCK8 deficiency and X-linked lymphoproliferative syndrome.

  4. Recruitment of DNA replication and damage response proteins to viral replication centers during infection with NS2 mutants of Minute Virus of Mice (MVM).

    Science.gov (United States)

    Ruiz, Zandra; Mihaylov, Ivailo S; Cotmore, Susan F; Tattersall, Peter

    2011-02-20

    MVM NS2 is essential for viral DNA amplification, but its mechanism of action is unknown. A classification scheme for autonomous parvovirus-associated replication (APAR) center development, based on NS1 distribution, was used to characterize abnormal APAR body maturation in NS2null mutant infections, and their organization examined for defects in host protein recruitment. Since acquisition of known replication factors appeared normal, we looked for differences in invoked DNA damage responses. We observed widespread association of H2AX/MDC1 damage response foci with viral replication centers, and sequestration and complex hyperphosphorylation of RPA(32), which occurred in wildtype and mutant infections. Quantifying these responses by western transfer indicated that both wildtype and NS2 mutant MVM elicited ATM activation, while phosphorylation of ATR, already basally activated in asynchronous A9 cells, was downregulated. We conclude that MVM infection invokes multiple damage responses that influence the APAR environment, but that NS2 does not modify the recruitment of cellular proteins.

  5. Mechanistic study of the anti-cancer effect of Gynostemma pentaphyllum saponins in the Apc(Min/+) mouse model.

    Science.gov (United States)

    Tai, William Chi-Shing; Wong, Wing-Yan; Lee, Magnolia Muk-Lan; Chan, Brandon Dow; Lu, Cheng; Hsiao, Wen-Luan Wendy

    2016-05-01

    Gynostemma pentaphyllum saponins (GpS) have been shown to have anti-cancer activity. However, the underlying mechanisms remain unclear. In this study, we used the Apc(Min) (/+) colorectal cancer (CRC) mouse model to investigate the anti-cancer effect of GpS and we demonstrated that GpS treatment could significantly reduce the number and size of intestinal polyps in Apc(Min) (/+) mice. In order to identify the potential targets and mechanisms involved, a comparative proteomics analysis was performed and 40 differentially expressed proteins after GpS treatment were identified. Bioinformatics analyses suggested a majority of these proteins were involved in processes related to cellular redox homeostasis, and predicted Raf-1 as a potential target of GpS. The upregulation of two proteins known to be involved in redox homeostasis, peroxiredoxin-1 (Prdx1) and peroxiredoxin-2 (Prdx2), and the downregulation of Raf-1 were validated using Western blot analysis. After further investigation of the associated signaling networks, we postulated that the anti-cancer effect of GpS was mediated through the upregulation of Prdx1 and Prdx2, suppression of Ras, RAF/MEK/ERK/STAT, PI3K/AKT/mTOR signaling and modulation of JNK/p38 MAPK signaling. We also examined the potential combinatorial effect of GpS with the chemotherapeutic 5-fluorouracil (5-FU) and found that GpS could enhance the anti-cancer efficacy of 5-FU, further suppressing the number of polyps in Apc(Min/+) mice. Our findings highlight the potential of GpS as an anti-cancer agent, the potential mechanisms of its anti-cancer activities, and its effect as an adjuvant of 5-FU in the chemotherapy of CRC. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. NT-3 protein levels are enhanced in the hippocampus of PRG1-deficient mice but remain unchanged in PRG1/LPA2 double mutants.

    Science.gov (United States)

    Petzold, Sandra; Sommer, Babette; Kröber, Andrea; Nitsch, Robert; Schwegler, Herbert; Vogt, Johannes; Roskoden, Thomas

    2016-01-26

    The plasticity-related gene 1 (PRG1) modulates bioactive lipids at the postsynaptic density and is a novel player in neuronal plasticity and regulation of glutamatergic transmission at principal neurons. PRG1, a neuronal molecule, is highly expressed during development and regeneration processes at the postsynaptic density, modulates synaptic lysophosphatidic acid (LPA) levels and is related to epilepsy and brain injury. In the present study, we analyzed the interaction between the synaptic molecules PRG1 and LPA2R with other plasticity-related molecules the neurotrophins. The protein levels of NGF, BDNF and NT-3 were measured using ELISA in hippocampal tissue of homozygous (PRG(-/-)) and heterozygous (PRG(+/-)) PRG1 deficient mice and compared to their wild type (PRG(+/+)/WT) littermates. In the hippocampus, protein levels of NT-3 were significantly increased in PRG(-/-) mice (compared to WT-litters) while protein levels of NGF and BDNF were not affected. Since PRG1 deficiency leads to increased neuronal excitability and higher hippocampal network activity, which may well influence neurotrophin levels, we further assessed PRG1 deficient mice on an LPA2-receptor (LPA2R) deficient background, reported to normalize hippocampal over-excitability in PRG1(-/-) mice. However, on an LPA2R deficient background, protein levels of NT-3 in PRG1(-/-) mice (PRG1(-/-)/LPA2R(-/-)) were not significantly different when compared to WT animals. Since PRG1 deficient mice showed over-excitability in glutamatergic neurons. This was normalized by additional LPA2R deletion, and we conclude the increased NT3-levels were directly or indirectly attributable to increased hippocampal network activity, possibly exerting a protective effect against over-excitability.

  7. High resolution genetic map of the adenomatous polyposis coli gene (APC) region

    Energy Technology Data Exchange (ETDEWEB)

    Olschwang, S.; Laurent-Puig, P.; Melot, T. [Institut Curie, Paris (France)

    1995-05-08

    Familial adenomatous polyposis coli (APC) is a dominantly inherited colorectal cancer susceptibility disease caused by mutation in a gene called APC located on chromosome 5q21. Presymptomatic diagnosis of this condition is recommended because it enables restriction of the efficient but demanding prevention program to those relatives that are genetically affected. The large size of the APC gene makes the direct search for the casual alteration difficult to implement in routine diagnostic laboratories. Because APC appears to be genetically homogeneous with alteration in a single locus causing the disease, cosegregation analysis may represent an alternative efficient method for presymptomatic diagnosis. However, the reliability of the risk estimation by linkage analysis in APC families is hampered by the lack of a short range genetic map of the APC locus. A combined approach including genotyping of 65 APC families, analysis of the CEPH database, and complementary typing of both APC and CEPH families has made it possible to derive the following genetic map: Centromere-[D5S82-D5S49]-0.02-D5S122-0.01-D5S136-0.01-D5S135-0.02-[APC-D5S346-MCC]-0.04-[D5S81-D5S64]-Telomere. This order, which differs from previously proposed genetic maps, is fully compatible with recent physical mapping data. These data should contribute to increase the reliability of the presymptomatic test for APC. 42 refs., 1 fig., 3 tabs.

  8. APC/CCDC20 and APC/C play pivotal roles in the process of embryonic development in Artemia sinica

    Science.gov (United States)

    Zhang, Mengchen; Yao, Feng; Luan, Hong; Zhao, Wei; Jing, Ting; Zhang, Shuang; Hou, Lin; Zou, Xiangyang

    2016-01-01

    Anaphase Promoting Complex or Cyclosome (APC/C) is a representative E3 ubiquitin ligase, triggering the transition of metaphase to anaphase by regulating degradation and ensures the exit from mitosis. Cell division cycle 20 (CDC20) and Cell division cycle 20 related protein 1 (CDH1), as co-activators of APC/C, play significant roles in the spindle assembly checkpoint, guiding ubiquitin-mediated degradation, together with CDC23. During the embryonic development of the brine shrimp, Artemia sinica, CDC20, CDH1 and CDC23 participate in cell cycle regulation, but the specific mechanisms of their activities remain unknown. Herein, the full-length cDNAs of cdc20 and cdc23 from A. sinica were cloned. Real-time PCR analyzed the expression levels of As-cdc20 and As-cdc23. The locations of CDH1, CDC20 and CDC23 showed no tissue or organ specificity. Furthermore, western blotting showed that the levels of As-CDC20, securin, cyclin B, CDK1, CDH1, CDC14B, CDC23 and geminin proteins conformed to their complicated degradation relationships during different embryo stages. Our research revealed that As-CDC20, As-CDH1 and APC mediate the mitotic progression, downstream proteins degradation and cellular differentiation in the process of embryonic development in A. sinica. PMID:27991546

  9. Cleft palate defect of Dlx1/2-/- mutant mice is caused by lack of vertical outgrowth in the posterior palate

    NARCIS (Netherlands)

    Jeong, J.; Cesario, J.; Zhao, Y.; Burns, L.; Westphal, H.; Rubenstein, J.L.

    2012-01-01

    BACKGROUND: Mice lacking the activities of Dlx1 and Dlx2 (Dlx1/2-/-) exhibit cleft palate, one of the most common human congenital defects, but the etiology behind this phenotype has been unknown. Therefore, we analyzed the morphological, cellular, and molecular changes caused by inactivation of Dlx

  10. Hyperoxia Exacerbates Postnatal Inflammation-Induced Lung Injury in Neonatal BRP-39 Null Mutant Mice Promoting the M1 Macrophage Phenotype

    Directory of Open Access Journals (Sweden)

    Mansoor A. Syed

    2013-01-01

    Full Text Available Rationale. Hyperoxia exposure to developing lungs—critical in the pathogenesis of bronchopulmonary dysplasia—may augment lung inflammation by inhibiting anti-inflammatory mediators in alveolar macrophages. Objective. We sought to determine the O2-induced effects on the polarization of macrophages and the role of anti-inflammatory BRP-39 in macrophage phenotype and neonatal lung injury. Methods. We used RAW264.7, peritoneal, and bone marrow derived macrophages for polarization (M1/M2 studies. For in vivo studies, wild-type (WT and BRP-39−/− mice received continuous exposure to 21% O2 (control mice or 100% O2 from postnatal (PN 1 to PN7 days, along with intranasal lipopolysaccharide (LPS administered on alternate days (PN2, -4, and -6. Lung histology, bronchoalveolar lavage (BAL cell counts, BAL protein, and cytokines measurements were performed. Measurements and Main Results. Hyperoxia differentially contributed to macrophage polarization by enhancing LPS induced M1 and inhibiting interleukin-4 induced M2 phenotype. BRP-39 absence led to further enhancement of the hyperoxia and LPS induced M1 phenotype. In addition, BRP-39−/− mice were significantly more sensitive to LPS plus hyperoxia induced lung injury and mortality compared to WT mice. Conclusions. These findings collectively indicate that BRP-39 is involved in repressing the M1 proinflammatory phenotype in hyperoxia, thereby deactivating inflammatory responses in macrophages and preventing neonatal lung injury.

  11. Phenotypes of PK2/PKR2 heterozygosis mutant mice%前动力蛋白2/前动力蛋白受体2基因杂合突变小鼠表型特征

    Institute of Scientific and Technical Information of China (English)

    肖玲; 周闻白; 周群勇; 胡仁明

    2012-01-01

    目的 观察前动力蛋白(PK2)、前动力蛋白受体2(PKR2)基因单拷贝丢失后小鼠生长发育及生殖系统发育情况.方法 对比观察PK2+/-、PKR2+/-、以及PK2+/-∶PKR2+/-复合杂合突变小鼠与野生型小鼠体重增长、外生殖器发育情况;免疫荧光染色法观察四组小鼠颅内促性腺激素释放激素(GnRH)神经元分布;阴道冲洗细胞涂片评估法观察小鼠动情周期. 结果 三组杂合突变小鼠体重增长、外生殖器发育及颅内GnRH神经元分布与野生型小鼠相比均无显著差异,但杂合突变小鼠动情周期延长、无规律,双基因杂合突变小鼠表现最明显. 结论 PK2、PKR2基因单拷贝丢失后虽不影响小鼠生殖系统和GnRH神经元发育,但雌鼠表现出动情周期紊乱.因此PK2/PKR2通路对生殖系统功能有调节作用.%Objective; To observe the phenotype changes including weight growth and reproductive system development in PK2/PKR2 heterozygosis mutant mice. Methods; The weight gain and external genitalia development were compared between the three heterozygosis mutant mice groups and the wild type group. GnRH neurons distribution was observed by fluorescent staining method in four groups. The stage of estrus cycle was determined by cytologic evaluation of vaginal smears. The vaginal exfoliate cells were smeared on glass slides, and the cytologic features were evaluated under microscopy Results; There were no changes in weight growth, external genitalia development and the GnRH neurons distribution in brain between the three mutant mice groups and the wild type mice group. The length of estrus cycle was extended in heterogeneous mice, especially in PK2/PKR2 heterogeneous mutation mice. Conclusions: Loss of one copy of PK2 or PKR2 gene did not change reproductive system and GnRH neurons development except estrous cycle. So PK2/PKR2 pathway may play roles in the regulation of reproductive system function.

  12. Gasdermin C Is Upregulated by Inactivation of Transforming Growth Factor β Receptor Type II in the Presence of Mutated Apc, Promoting Colorectal Cancer Proliferation.

    Science.gov (United States)

    Miguchi, Masashi; Hinoi, Takao; Shimomura, Manabu; Adachi, Tomohiro; Saito, Yasufumi; Niitsu, Hiroaki; Kochi, Masatoshi; Sada, Haruki; Sotomaru, Yusuke; Ikenoue, Tsuneo; Shigeyasu, Kunitoshi; Tanakaya, Kohji; Kitadai, Yasuhiko; Sentani, Kazuhiro; Oue, Naohide; Yasui, Wataru; Ohdan, Hideki

    2016-01-01

    Mutations in TGFBR2, a component of the transforming growth factor (TGF)-β signaling pathway, occur in high-frequency microsatellite instability (MSI-H) colorectal cancer (CRC). In mouse models, Tgfbr2 inactivation in the intestinal epithelium accelerates the development of malignant intestinal tumors in combination with disruption of the Wnt-β-catenin pathway. However, no studies have further identified the genes influenced by TGFBR2 inactivation following disruption of the Wnt-β-catenin pathway. We previously described CDX2P-G19Cre;Apcflox/flox mice, which is stochastically null for Apc in the colon epithelium. In this study, we generated CDX2P-G19Cre;Apcflox/flox;Tgfbr2flox/flox mice, with simultaneous loss of Apc and Tgfbr2. These mice developed tumors, including adenocarcinoma in the proximal colon. We compared gene expression profiles between tumors of the two types of mice using microarray analysis. Our results showed that the expression of the murine homolog of GSDMC was significantly upregulated by 9.25-fold in tumors of CDX2P-G19Cre;Apcflox/flox;Tgfbr2flox/flox mice compared with those of CDX2P-G19Cre;Apcflox/flox mice. We then investigated the role of GSDMC in regulating CRC tumorigenesis. The silencing of GSDMC led to a significant reduction in the proliferation and tumorigenesis of CRC cell lines, whereas the overexpression of GSDMC enhanced cell proliferation. These results suggested that GSDMC functioned as an oncogene, promoting cell proliferation in colorectal carcinogenesis. In conclusion, combined inactivation of both Apc and Tgfbr2 in the colon epithelium of a CRC mouse model promoted development of adenocarcinoma in the proximal colon. Moreover, GSDMC was upregulated by TGFBR2 mutation in CRC and promoted tumor cell proliferation in CRC carcinogenesis, suggesting that GSDMC may be a promising therapeutic target.

  13. The effects of various inhibitors on the regulation of orotic acid excretion in sparse-fur mutant mice (spf/Y) deficient in ornithine transcarbamylase.

    Science.gov (United States)

    Nelson, J; Qureshi, I A; Vasudevan, S; Sarma, D S

    1993-10-01

    Experiments were conducted to determine whether the excessive orotic aciduria, induced in sparse-fur male mice (spf/Y) deficient in ornithine transcarbamylase (OTC), may be regulated by some inhibitors, such as acivicin (0.014 mmol/100 g body weight, i.p.), N-(phosphonoacetyl)-L-aspartate (PALA, 2.5 mg/100 g body weight, i.p.), adenine (3 g/kg diet) and cycloheximide (0.35 mmol/kg body weight, i.p.). We also administered ornithine (1 mmol/100 g body weight, i.p.), a substrate of the urea cycle, to alleviate the metabolic deficiency of arginine in spf/Y mice which may also be responsible for excessive orotic aciduria. The orotic aciduria remained insensitive to acivicin, indicating mitochondria as the source of carbamyl phosphate. However, orotate excretion was significantly decreased by PALA (P handle excess mitochondrial carbamyl phosphate and orotic acid.

  14. Herpes simplex virus type-1(HSV-1 oncolytic and highly fusogenic mutants carrying the NV1020 genomic deletion effectively inhibit primary and metastatic tumors in mice

    Directory of Open Access Journals (Sweden)

    David Andrew T

    2008-06-01

    Full Text Available Abstract Background The NV1020 oncolytic herpes simplex virus type-1 has shown significant promise for the treatment of many different types of tumors in experimental animal models and human trials. Previously, we described the construction and use of the NV1020-like virus OncSyn to treat human breast tumors implanted in nude mice. The syncytial mutation gKsyn1 (Ala-to-Val at position 40 was introduced into the OncSyn viral genome cloned into a bacterial artificial chromosome using double-red mutagenesis in E. coli to produce the OncdSyn virus carrying syncytial mutations in both gB(syn3 and gK(syn1. Results The OncdSyn virus caused extensive virus-induced cell fusion in cell culture. The oncolytic potential of the OncSyn and OncdSyn viruses was tested in the highly metastatic syngeneic mouse model system, which utilizes 4T1 murine mammary cancer cells implanted within the interscapular region of Balb/c mice. Mice were given three consecutive intratumor injections of OncSyn, OncdSyn, or phosphate buffered saline four days apart. Both OncSyn and OncdSyn virus injections resulted in significant reduction of tumor sizes (p Conclusion These results show that the attenuated, but highly fusogenic OncSyn and OncdSyn viruses can effectively reduce primary and metastatic breast tumors in immuncompetent mice. The available bac-cloned OncSyn and OncdSyn viral genomes can be rapidly modified to express a number of different anti-tumor and immunomodulatory genes that can further enhance their anti-tumor potency.

  15. Regulation of blood pressure, oxidative stress and AT1R by high salt diet in mutant human dopamine D5 receptor transgenic mice.

    Science.gov (United States)

    Liu, Xing; Wang, Wenjie; Chen, Wei; Jiang, Xiaoliang; Zhang, Yanrong; Wang, Zihao; Yang, Jian; Jones, John E; Jose, Pedro A; Yang, Zhiwei

    2015-06-01

    Humans have dopamine D5 receptors (hD5R) with single-nucleotide polymorphisms and a diminished function. We generated hD5(F173L) cDNA that has a decreased response to D5R agonist-mediated increase in cAMP production and increased production of reactive oxygen species, relative to wild-type hD5R (hD5(WT)) cDNA expressed in Chinese hamster ovary cells. To investigate the role of hD5(F173L) in the pathogenesis of salt-sensitive hypertension, we generated transgenic mice overexpressing hD5(F173L) or hD5(WT) and fed them normal (0.8% NaCl) or high (4% NaCl) salt diet. On normal salt diet, the blood pressure, and renal NADPH oxidase activity and angiotensin type 1 receptor (AT1R) expression were higher in hD5(F173L) than hD5(WT) transgenic mice. After 2 weeks on high salt diet, the blood pressure and renal NADPH oxidase activity, but not AT1R expression, were increased in hD5(F173L) but not in hD5(WT) transgenic mice. Candesartan, an AT1R antagonist, decreased the blood pressure and NADPH oxidase activity in hD5(F173L) but not in hD5(WT) transgenic mice. We suggest that the ability of the hD5R to negatively regulate the renal NADPH oxidase activity and AT1R function may have important implications in the pathogenesis of salt-sensitive blood pressure. However, the mechanisms involved in regulating the balance of renal D5R and AT1R function in the oxidative stress-mediated salt-sensitive blood pressure remain to be determined.

  16. Inherited colorectal polyposis and cancer risk of the APC I1307K polymorphism.

    OpenAIRE

    Gryfe, R; Di Nicola, N; G. Lal; Gallinger, S.; Redston, M

    1999-01-01

    Germ-line and somatic truncating mutations of the APC gene are thought to initiate colorectal tumor formation in familial adenomatous polyposis syndrome and sporadic colorectal carcinogenesis, respectively. Recently, an isoleucine-->lysine polymorphism at codon 1307 (I1307K) of the APC gene has been identified in 6%-7% of the Ashkenazi Jewish population. To assess the risk of this common APC allelic variant in colorectal carcinogenesis, we have analyzed a large cohort of unselected Ashkenazi ...

  17. Electrodialytically treated MSWI APC residue as substitute for cement in mortar

    DEFF Research Database (Denmark)

    Kirkelund, Gunvor Marie; Geiker, Mette Rica; Jensen, Pernille Erland

    2014-01-01

    Air pollution control (APC) residues from municipal solid waste incineration (MSWI) are considered hazardous waste and need pretreatment prior to possible reuse. Here, two MSWI APC residues, from which the most mobile fraction of heavy metals and salts has been removed by carbonation and...... and comparable to both the reference mortar and mortar with coal fly ash. These results indicate that electrodialytic remediation could be used a pre-treatment method for MSWI APC residues prior to reuse in mortar....

  18. An oral recombinant Salmonella enterica serovar Typhimurium mutant elicits systemic antigen-specific CD8+ T cell cytokine responses in mice

    Directory of Open Access Journals (Sweden)

    Chin'ombe Nyasha

    2009-04-01

    Full Text Available Abstract Background The induction of antigen-specific CD8+ T cell cytokine responses against an attenuated, oral recombinant Salmonella enterica serovar Typhimurium vaccine expressing a green fluorescent protein (GFP model antigen was investigated. A GFP expression plasmid was constructed in which the gfp gene was fused in-frame with the 5' domain of the Escherichia coli β-galactosidase α-gene fragment with expression under the lac promoter. Groups of mice were orally immunized three times with the bacteria and systemic CD8+ T cell cytokine responses were evaluated. Results High level of the GFP model antigen was expressed by the recombinant Salmonella vaccine vector. Systemic GFP-specific CD8+ T cell cytokine (IFN-γ and IL-4 immune responses were detected after mice were orally vaccinated with the bacteria. It was shown that 226 net IFN-γ and 132 net IL-4 GFP-specific SFUs/10e6 splenocytes were formed in an ELISPOT assay. The level of IFN-γ produced by GFP peptide-stimulated cells was 65.2-fold above background (p Conclusion These results suggested that a high expressing recombinant Salmonella vaccine given orally to mice would elicit antigen-specific CD8+ T cell responses in the spleen. Salmonella bacteria may, therefore, be used as potential mucosal vaccine vectors.

  19. RNase H2 catalytic core Aicardi-Goutières syndrome–related mutant invokes cGAS–STING innate immune-sensing pathway in mice

    Science.gov (United States)

    Pokatayev, Vladislav; Hasin, Naushaba; Chon, Hyongi; Cerritelli, Susana M.; Sakhuja, Kiran; Ward, Jerrold M.; Morris, H. Douglas; Yan, Nan

    2016-01-01

    The neuroinflammatory autoimmune disease Aicardi-Goutières syndrome (AGS) develops from mutations in genes encoding several nucleotide-processing proteins, including RNase H2. Defective RNase H2 may induce accumulation of self-nucleic acid species that trigger chronic type I interferon and inflammatory responses, leading to AGS pathology. We created a knock-in mouse model with an RNase H2 AGS mutation in a highly conserved residue of the catalytic subunit, Rnaseh2aG37S/G37S (G37S), to understand disease pathology. G37S homozygotes are perinatal lethal, in contrast to the early embryonic lethality previously reported for Rnaseh2b- or Rnaseh2c-null mice. Importantly, we found that the G37S mutation led to increased expression of interferon-stimulated genes dependent on the cGAS–STING signaling pathway. Ablation of STING in the G37S mice results in partial rescue of the perinatal lethality, with viable mice exhibiting white spotting on their ventral surface. We believe that the G37S knock-in mouse provides an excellent animal model for studying RNASEH2-associated autoimmune diseases. PMID:26880576