Bone Mass and Strength are Significantly Improved in Mice Overexpressing Human WNT16 in Osteocytes.

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Alam, Imranul; Reilly, Austin M; Alkhouli, Mohammed; Gerard-O'Riley, Rita L; Kasipathi, Charishma; Oakes, Dana K; Wright, Weston B; Acton, Dena; McQueen, Amie K; Patel, Bhavmik; Lim, Kyung-Eun; Robling, Alexander G; Econs, Michael J

2017-04-01

Recently, we demonstrated that osteoblast-specific overexpression of human WNT16 increased both cortical and trabecular bone mass and structure in mice. To further identify the cell-specific role of Wnt16 in bone homeostasis, we created transgenic (TG) mice overexpressing human WNT16 in osteocytes using Dmp1 promoter (Dmp1-hWNT16 TG) on C57BL/6 (B6) background. We analyzed bone phenotypes and serum bone biomarkers, performed gene expression analysis and measured dynamic bone histomorphometry in Dmp1-hWNT16 TG and wild-type (WT) mice. Compared to WT mice, Dmp1-hWNT16 TG mice exhibited significantly higher whole-body, spine and femoral aBMD, BMC and trabecular (BV/TV, Tb.N, and Tb.Th) and cortical (bone area and thickness) parameters in both male and female at 12 weeks of age. Femur stiffness and ultimate force were also significantly improved in the Dmp1-hWNT16 TG female mice, compared to sex-matched WT littermates. In addition, female Dmp1-hWNT16 TG mice displayed significantly higher MS/BS, MAR and BFR/BS compared to the WT mice. Gene expression analysis demonstrated significantly higher mRNA level of Alp in both male and female Dmp1-hWNT16 TG mice and significantly higher levels of Osteocalcin, Opg and Rankl in the male Dmp1-hWNT16 TG mice in bone tissue compared to sex-matched WT mice. These results indicate that WNT16 plays a critical role for acquisition of both cortical and trabecular bone mass and strength. Strategies designed to use WNT16 as a target for therapeutic interventions will be valuable to treat osteoporosis and other low bone mass conditions.

Ectoderm-targeted overexpression of the glucocorticoid receptor induces hypohidrotic ectodermal dysplasia.

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Cascallana, Jose Luis; Bravo, Ana; Donet, Eva; Leis, Hugo; Lara, Maria Fernanda; Paramio, Jesús M; Jorcano, José L; Pérez, Paloma

2005-06-01

Hypohidrotic ectodermal dysplasia is a human syndrome defined by maldevelopment of one or more ectodermal-derived tissues, including the epidermis and cutaneous appendices, teeth, and exocrine glands. The molecular bases of this pathology converge in a dysfunction of the transcription factor nuclear factor of the kappa-enhancer in B cells (NF-kappaB), which is essential to epithelial homeostasis and development. A number of mouse models bearing disruptions in NF-kappaB signaling have been reported to manifest defects in ectodermal derivatives. In ectoderm-targeted transgenic mice overexpressing the glucocorticoid receptor (GR) [keratin 5 (K5)-GR mice], the NF-kappaB activity is greatly decreased due to functional antagonism between GR and NF-kappaB. Here, we report that K5-GR mice exhibit multiple epithelial defects in hair follicle, tooth, and palate development. Additionally, these mice lack Meibomian glands and display underdeveloped sweat and preputial glands. These phenotypic features appear to be mediated specifically by ligand-activated GR because the synthetic analog dexamethasone induced similar defects in epithelial morphogenesis, including odontogenesis, in wild-type mice. We have focused on tooth development in K5-GR mice and found that an inhibitor of steroid synthesis partially reversed the abnormal phenotype. Immunostaining revealed reduced expression of the inhibitor of kappaB kinase subunits, IKKalpha and IKKgamma, and diminished p65 protein levels in K5-GR embryonic tooth, resulting in a significantly reduced kappaB-binding activity. Remarkably, altered NF-kappaB activity elicited by GR overexpression correlated with a dramatic decrease in the protein levels of DeltaNp63 in tooth epithelia without affecting Akt, BMP4, or Foxo3a. Given that many of the 170 clinically distinct ectodermal dysplasia syndromes still remain without cognate genes, deciphering the molecular mechanisms of this mouse model with epithelial NF-kappaB and p63 dysfunction may

TRIP-Br2 promotes oncogenesis in nude mice and is frequently overexpressed in multiple human tumors.

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Cheong, Jit Kong; Gunaratnam, Lakshman; Zang, Zhi Jiang; Yang, Christopher M; Sun, Xiaoming; Nasr, Susan L; Sim, Khe Guan; Peh, Bee Keow; Rashid, Suhaimi Bin Abdul; Bonventre, Joseph V; Salto-Tellez, Manuel; Hsu, Stephen I

2009-01-20

Members of the TRIP-Br/SERTAD family of mammalian transcriptional coregulators have recently been implicated in E2F-mediated cell cycle progression and tumorigenesis. We, herein, focus on the detailed functional characterization of the least understood member of the TRIP-Br/SERTAD protein family, TRIP-Br2 (SERTAD2). Oncogenic potential of TRIP-Br2 was demonstrated by (1) inoculation of NIH3T3 fibroblasts, which were engineered to stably overexpress ectopic TRIP-Br2, into athymic nude mice for tumor induction and (2) comprehensive immunohistochemical high-throughput screening of TRIP-Br2 protein expression in multiple human tumor cell lines and human tumor tissue microarrays (TMAs). Clinicopathologic analysis was conducted to assess the potential of TRIP-Br2 as a novel prognostic marker of human cancer. RNA interference of TRIP-Br2 expression in HCT-116 colorectal carcinoma cells was performed to determine the potential of TRIP-Br2 as a novel chemotherapeutic drug target. Overexpression of TRIP-Br2 is sufficient to transform murine fibroblasts and promotes tumorigenesis in nude mice. The transformed phenotype is characterized by deregulation of the E2F/DP-transcriptional pathway through upregulation of the key E2F-responsive genes CYCLIN E, CYCLIN A2, CDC6 and DHFR. TRIP-Br2 is frequently overexpressed in both cancer cell lines and multiple human tumors. Clinicopathologic correlation indicates that overexpression of TRIP-Br2 in hepatocellular carcinoma is associated with a worse clinical outcome by Kaplan-Meier survival analysis. Small interfering RNA-mediated (siRNA) knockdown of TRIP-Br2 was sufficient to inhibit cell-autonomous growth of HCT-116 cells in vitro. This study identifies TRIP-Br2 as a bona-fide protooncogene and supports the potential for TRIP-Br2 as a novel prognostic marker and a chemotherapeutic drug target in human cancer.

Hepatic NPC1L1 overexpression ameliorates glucose metabolism in diabetic mice via suppression of gluconeogenesis.

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Kurano, Makoto; Hara, Masumi; Satoh, Hiroaki; Tsukamoto, Kazuhisa

2015-05-01

Inhibition of intestinal NPC1L1 by ezetimibe has been demonstrated to improve glucose metabolism in rodent models; however, the role of hepatic NPC1L1 in glucose metabolism has not been elucidated. In this study, we analyzed the effects of hepatic NPC1L1 on glucose metabolism. We overexpressed NPC1L1 in the livers of lean wild type mice, diet-induced obesity mice and db/db mice with adenoviral gene transfer. We found that in all three mouse models, hepatic NPC1L1 overexpression lowered fasting blood glucose levels as well as blood glucose levels on ad libitum; in db/db mice, hepatic NPC1L1 overexpression improved blood glucose levels to almost the same as those found in lean wild type mice. A pyruvate tolerance test revealed that gluconeogenesis was suppressed by hepatic NPC1L1 overexpression. Further analyses revealed that hepatic NPC1L1 overexpression decreased the expression of FoxO1, resulting in the reduced expression of G6Pase and PEPCK, key enzymes in gluconeogenesis. These results indicate that hepatic NPC1L1 might have distinct properties of suppressing gluconeogenesis via inhibition of FoxO1 pathways. Copyright © 2015 Elsevier Inc. All rights reserved.

BDNF Overexpression Exhibited Bilateral Effect on Neural Behavior in SCT Mice Associated with AKT Signal Pathway.

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Chen, Mei-Rong; Dai, Ping; Wang, Shu-Fen; Song, Shu-Hua; Wang, Hang-Ping; Zhao, Ya; Wang, Ting-Hua; Liu, Jia

2016-10-01

Spinal cord injury (SCI), a severe health problem in worldwide, was commonly associated with functional disability and reduced quality of life. As the expression of brain-derived neurotrophic factor (BDNF) was substantial event in injured spinal cord, we hypothesized whether BDNF-overexpression could be in favor of the recovery of both sensory function and hindlimb function after SCI. By using BDNF-overexpression transgene mice [CMV-BDNF 26 (CB26) mice] we assessed the role of BDNF on the recovery of neurological behavior in spinal cord transection (SCT) model. BMS score and tail-flick test was performed to evaluate locomotor function and sensory function, respectively. Immunohistochemistry was employed to detect the location and the expression of BDNF, NeuN, 5-HT, GAP-43, GFAP as well as CGRP, and the level of p-AKT and AKT were examined through western blot analysis. BDNF overexpressing resulted in significant locomotor functional recovery from 21 to 28 days after SCT, compared with wild type (WT)+SCT group. Meanwhile, the NeuN, 5-HT and GAP-43 positive cells were markedly increased in ventral horn in BDNF overexpression animals, compared with WT mice with SCT. Moreover, the crucial molecular signal, p-AKT/AKT has been largely up-regulated, which is consistent with the improvement of locomotor function. However, in this study, thermal hyperpathia encountered in sham (CB26) group and WT+SCT mice and further aggravated in CB26 mice after SCT. Also, following SCT, the significant augment of positive-GFAP astrocytes and CGRP fibers were found in WT+SCT mice, and further increase was seen in BDNF over-expression transgene mice. BDNF-overexpression may not only facilitate the recovery of locomotor function via AKT pathway, but also contributed simultaneously to thermal hyperalgesia after SCT.

Impaired baroreflex function in mice overexpressing alpha-synuclein

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Sheila eFleming

2013-07-01

Full Text Available Cardiovascular autonomic dysfunction, such as orthostatic hypotension consequent to baroreflex failure and cardiac sympathetic denervation, is frequently observed in the synucleinopathy Parkinson’s disease (PD. In the present study, the baroreceptor reflex was assessed in mice overexpressing human wildtype alpha-synuclein (Thy1-aSyn, a genetic mouse model of synucleinopathy. The beat-to-beat change in heart rate, computed from R-R interval, in relation to blood pressure was measured in anesthetized and conscious mice equipped with arterial blood pressure telemetry transducers during transient bouts of hypertension and hypotension. Compared to wildtype, tachycardia following nitroprusside-induced hypotension was significantly reduced in Thy1-aSyn mice. Thy1-aSyn mice also showed an abnormal cardiovascular response (i.e., diminished tachycardia to muscarinic blockade with atropine. We conclude that Thy1-aSyn mice have impaired basal and dynamic range of sympathetic and parasympathetic-mediated changes in heart rate and will be a useful model for long-term study of cardiovascular autonomic dysfunction associated with PD.

Transplantation of germ cells from glial cell line-derived neurotrophic factor-overexpressing mice to host testes depleted of endogenous spermatogenesis by fractionated irradiation

NARCIS (Netherlands)

Creemers, L. B.; Meng, X.; den Ouden, K.; van Pelt, A. M. M.; Izadyar, F.; Santoro, M.; Sariola, H.; de rooij, D. G.

2002-01-01

With a novel method of eliminating spermatogenesis in host animals, male germ cells isolated from mice with targeted overexpression of glial cell line-derived neurotrophic factor (GDNF) were transplanted to evaluate their ability to reproduce the phenotype previously found in the transgenic animals.

Bmi1 overexpression in the cerebellar granule cell lineage of mice affects cell proliferation and survival without initiating medulloblastoma formation

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Hourinaz Behesti

2013-01-01

BMI1 is a potent inducer of neural stem cell self-renewal and neural progenitor cell proliferation during development and in adult tissue homeostasis. It is overexpressed in numerous human cancers – including medulloblastomas, in which its functional role is unclear. We generated transgenic mouse lines with targeted overexpression of Bmi1 in the cerebellar granule cell lineage, a cell type that has been shown to act as a cell of origin for medulloblastomas. Overexpression of Bmi1 in granule cell progenitors (GCPs led to a decrease in cerebellar size due to decreased GCP proliferation and repression of the expression of cyclin genes, whereas Bmi1 overexpression in postmitotic granule cells improved cell survival in response to stress by altering the expression of genes in the mitochondrial cell death pathway and of Myc and Lef-1. Although no medulloblastomas developed in ageing cohorts of transgenic mice, crosses with Trp53−/− mice resulted in a low incidence of medulloblastoma formation. Furthermore, analysis of a large collection of primary human medulloblastomas revealed that tumours with a BMI1high TP53low molecular profile are significantly enriched in Group 4 human medulloblastomas. Our data suggest that different levels and timing of Bmi1 overexpression yield distinct cellular outcomes within the same cellular lineage. Importantly, Bmi1 overexpression at the GCP stage does not induce tumour formation, suggesting that BMI1 overexpression in GCP-derived human medulloblastomas probably occurs during later stages of oncogenesis and might serve to enhance tumour cell survival.

Overexpression of Shox2 Leads to Congenital Dysplasia of the Temporomandibular Joint in Mice

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Xihai Li

2014-07-01

Full Text Available Our previous study reported that inactivation of Shox2 led to dysplasia and ankylosis of the temporomandibular joint (TMJ, and that replacing Shox2 with human Shox partially rescued the phenotype with a prematurely worn out articular disc. However, the mechanisms of Shox2 activity in TMJ development remain to be elucidated. In this study, we investigated the molecular and cellular basis for the congenital dysplasia of TMJ in Wnt1-Cre; pMes-stop Shox2 mice. We found that condyle and glenoid fossa dysplasia occurs primarily in the second week after the birth. The dysplastic TMJ of Wnt1-Cre; pMes-stop Shox2 mice exhibits a loss of Collagen type I, Collagen type II, Ihh and Gli2. In situ zymography and immunohistochemistry further demonstrate an up-regulation of matrix metalloproteinases (MMPs, MMP9 and MMP13, accompanied by a significantly increased cell apoptosis. In addition, the cell proliferation and expressions of Sox9, Runx2 and Ihh are no different in the embryonic TMJ between the wild type and mutant mice. Our results show that overexpression of Shox2 leads to the loss of extracellular matrix and the increase of cell apoptosis in TMJ dysplasia by up-regulating MMPs and down-regulating the Ihh signaling pathway.

TRIP-Br2 promotes oncogenesis in nude mice and is frequently overexpressed in multiple human tumors

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Peh Bee

2009-01-01

Full Text Available Abstract Background Members of the TRIP-Br/SERTAD family of mammalian transcriptional coregulators have recently been implicated in E2F-mediated cell cycle progression and tumorigenesis. We, herein, focus on the detailed functional characterization of the least understood member of the TRIP-Br/SERTAD protein family, TRIP-Br2 (SERTAD2. Methods Oncogenic potential of TRIP-Br2 was demonstrated by (1 inoculation of NIH3T3 fibroblasts, which were engineered to stably overexpress ectopic TRIP-Br2, into athymic nude mice for tumor induction and (2 comprehensive immunohistochemical high-throughput screening of TRIP-Br2 protein expression in multiple human tumor cell lines and human tumor tissue microarrays (TMAs. Clinicopathologic analysis was conducted to assess the potential of TRIP-Br2 as a novel prognostic marker of human cancer. RNA interference of TRIP-Br2 expression in HCT-116 colorectal carcinoma cells was performed to determine the potential of TRIP-Br2 as a novel chemotherapeutic drug target. Results Overexpression of TRIP-Br2 is sufficient to transform murine fibroblasts and promotes tumorigenesis in nude mice. The transformed phenotype is characterized by deregulation of the E2F/DP-transcriptional pathway through upregulation of the key E2F-responsive genes CYCLIN E, CYCLIN A2, CDC6 and DHFR. TRIP-Br2 is frequently overexpressed in both cancer cell lines and multiple human tumors. Clinicopathologic correlation indicates that overexpression of TRIP-Br2 in hepatocellular carcinoma is associated with a worse clinical outcome by Kaplan-Meier survival analysis. Small interfering RNA-mediated (siRNA knockdown of TRIP-Br2 was sufficient to inhibit cell-autonomous growth of HCT-116 cells in vitro. Conclusion This study identifies TRIP-Br2 as a bona-fide protooncogene and supports the potential for TRIP-Br2 as a novel prognostic marker and a chemotherapeutic drug target in human cancer.

Fat-Specific DsbA-L Overexpression Promotes Adiponectin Multimerization and Protects Mice From Diet-Induced Obesity and Insulin Resistance

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Liu, Meilian; Xiang, Ruihua; Wilk, Sarah Ann; Zhang, Ning; Sloane, Lauren B.; Azarnoush, Kian; Zhou, Lijun; Chen, Hongzhi; Xiang, Guangda; Walter, Christi A.; Austad, Steven N.; Musi, Nicolas; DeFronzo, Ralph A.; Asmis, Reto; Scherer, Philipp E.; Dong, Lily Q.; Liu, Feng

2012-01-01

The antidiabetic and antiatherosclerotic effects of adiponectin make it a desirable drug target for the treatment of metabolic and cardiovascular diseases. However, the adiponectin-based drug development approach turns out to be difficult due to extremely high serum levels of this adipokine. On the other hand, a significant correlation between adiponectin multimerization and its insulin-sensitizing effects has been demonstrated, suggesting a promising alternative therapeutic strategy. Here we show that transgenic mice overexpressing disulfide bond A oxidoreductase-like protein in fat (fDsbA-L) exhibited increased levels of total and the high-molecular-weight form of adiponectin compared with wild-type (WT) littermates. The fDsbA-L mice also displayed resistance to diet-induced obesity, insulin resistance, and hepatic steatosis compared with WT control mice. The protective effects of DsbA-L overexpression on diet-induced insulin resistance, but not increased body weight and fat cell size, were significantly decreased in adiponectin-deficient fDsbA-L mice (fDsbA-L/Ad−/−). In addition, the fDsbA-L/Ad−/− mice displayed greater activity and energy expenditure compared with adiponectin knockout mice under a high-fat diet. Taken together, our results demonstrate that DsbA-L protects mice from diet-induced obesity and insulin resistance through adiponectin-dependent and independent mechanisms. In addition, upregulation of DsbA-L could be an effective therapeutic approach for the treatment of obesity and its associated metabolic disorders. PMID:22807031

EGF receptor-targeted synthetic double-stranded RNA eliminates glioblastoma, breast cancer, and adenocarcinoma tumors in mice.

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Alexei Shir

2006-01-01

Full Text Available BACKGROUND: Glioblastoma multiforme (GBM is the most lethal form of brain cancer. With the available treatments, survival does not exceed 12-14 mo from the time of diagnosis. We describe a novel strategy to selectively induce the death of glioblastoma cells and other cancer cells that over-express the EGF receptor. Using a non-viral delivery vector that homes to the EGF receptor, we target synthetic anti-proliferative dsRNA (polyinosine-cytosine [poly IC], a strong activator of apoptosis, selectively to cancer cells. METHODS AND FINDINGS: Poly IC was delivered by means of a non-viral vector: 25kDa polyethylenimine-polyethyleneglycol-EGF (PEI25-PEG-EGF. EGFR-targeted poly IC induced rapid apoptosis in the target cells in vitro and in vivo. Expression of several cytokines and "bystander killing" of untransfected tumor cells was detected in vitro and in vivo. Intra-tumoral delivery of the EGFR-targeted poly IC induced the complete regression of pre-established intracranial tumors in nude mice, with no obvious adverse toxic effects on normal brain tissue. A year after treatment completion the treated mice remain cancer-free and healthy. Similarly, non-viral delivery of poly IC completely eliminated pre-established breast cancer and adenocarcinoma xenografts derived from EGFR over-expressing cancer cell lines, suggesting that the strategy is applicable to other EGFR-over-expressing tumors. CONCLUSION: The strategy described has yielded an effective treatment of EGFR over-expressing GBM in an animal model. If this strategy is translated successfully to the clinical setting, it may actually offer help to GBM patients. Moreover the elimination of two additional EGFR over-expressing cancers in vivo suggests that in principle this strategy can be applied to treat other tumors that over-express EGFR.

Cardiac overexpression of Mammalian enabled (Mena) exacerbates heart failure in mice.

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Belmonte, Stephen L; Ram, Rashmi; Mickelsen, Deanne M; Gertler, Frank B; Blaxall, Burns C

2013-09-15

Mammalian enabled (Mena) is a key regulator of cytoskeletal actin dynamics, which has been implicated in heart failure (HF). We have previously demonstrated that cardiac Mena deletion produced cardiac dysfunction with conduction abnormalities and hypertrophy. Moreover, elevated Mena expression correlates with HF in human and animal models, yet the precise role of Mena in cardiac pathophysiology is unclear. In these studies, we evaluated mice with cardiac myocyte-specific Mena overexpression (TTA/TgTetMena) comparable to that observed in cardiac pathology. We found that the hearts of TTA/TgTetMena mice were functionally and morphologically comparable to wild-type littermates, except for mildly increased heart mass in the transgenic mice. Interestingly, TTA/TgTetMena mice were particularly susceptible to cardiac injury, as these animals experienced pronounced decreases in ejection fraction and fractional shortening as well as heart dilatation and hypertrophy after transverse aortic constriction (TAC). By "turning off" Mena overexpression in TTA/TgTetMena mice either immediately prior to or immediately after TAC surgery, we discovered that normalizing Mena levels eliminated cardiac hypertrophy in TTA/TgTetMena animals but did not preclude post-TAC cardiac functional deterioration. These findings indicate that hearts with increased levels of Mena fare worse when subjected to cardiac injury and suggest that Mena contributes to HF pathophysiology.

Enzyme replacement therapy rescues weakness and improves muscle pathology in mice with X-linked myotubular myopathy.

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Lawlor, Michael W; Armstrong, Dustin; Viola, Marissa G; Widrick, Jeffrey J; Meng, Hui; Grange, Robert W; Childers, Martin K; Hsu, Cynthia P; O'Callaghan, Michael; Pierson, Christopher R; Buj-Bello, Anna; Beggs, Alan H

2013-04-15

No effective treatment exists for patients with X-linked myotubular myopathy (XLMTM), a fatal congenital muscle disease caused by deficiency of the lipid phosphatase, myotubularin. The Mtm1δ4 and Mtm1 p.R69C mice model severely and moderately symptomatic XLMTM, respectively, due to differences in the degree of myotubularin deficiency. Contractile function of intact extensor digitorum longus (EDL) and soleus muscles from Mtm1δ4 mice, which produce no myotubularin, is markedly impaired. Contractile forces generated by chemically skinned single fiber preparations from Mtm1δ4 muscle were largely preserved, indicating that weakness was largely due to impaired excitation contraction coupling. Mtm1 p.R69C mice, which produce small amounts of myotubularin, showed impaired contractile function only in EDL muscles. Short-term replacement of myotubularin with a prototypical targeted protein replacement agent (3E10Fv-MTM1) in Mtm1δ4 mice improved contractile function and muscle pathology. These promising findings suggest that even low levels of myotubularin protein replacement can improve the muscle weakness and reverse the pathology that characterizes XLMTM.

Hepatic steatosis in transgenic mice overexpressing human histone deacetylase 1

International Nuclear Information System (INIS)

Wang, Ai-Guo; Seo, Sang-Beom; Moon, Hyung-Bae; Shin, Hye-Jun; Kim, Dong Hoon; Kim, Jin-Man; Lee, Tae-Hoon; Kwon, Ho Jeong; Yu, Dae-Yeul; Lee, Dong-Seok

2005-01-01

It is generally thought that histone deacetylases (HDACs) play important roles in the transcriptional regulation of genes. However, little information is available concerning the specific functions of individual HDACs in disease states. In this study, two transgenic mice lines were established which harbored the human HDAC1 gene. Overexpressed HDAC1 was detected in the nuclei of transgenic liver cells, and HDAC1 enzymatic activity was significantly higher in the transgenic mice than in control littermates. The HDAC1 transgenic mice exhibited a high incidence of hepatic steatosis and nuclear pleomorphism. Molecular studies showed that HDAC1 may contribute to nuclear pleomorphism through the p53/p21 signaling pathway

Middle-aged human apoE4 targeted-replacement mice show retention deficits on a wide range of spatial memory tasks.

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Bour, Alexandra; Grootendorst, Jeannette; Vogel, Elise; Kelche, Christian; Dodart, Jean-Cosme; Bales, Kelly; Moreau, Pierre-Henri; Sullivan, Patrick M; Mathis, Chantal

2008-11-21

Apolipoprotein (apo) E4, one of three human apoE (h-apoE) isoforms, has been identified as a major genetic risk factor for Alzheimer's disease and for cognitive deficits associated with aging. However, the biological mechanisms involving apoE in learning and memory processes are unclear. A potential isoform-dependent role of apoE in cognitive processes was studied in human apoE targeted-replacement (TR) mice. These mice express either the human apoE3 or apoE4 gene under the control of endogenous murine apoE regulatory sequences, resulting in physiological expression of h-apoE in both a temporal and spatial pattern similar to humans. Male and female apoE3-TR, apoE4-TR, apoE-knockout and C57BL/6J mice (15-18 months) were tested with spatial memory and avoidance conditioning tasks. Compared to apoE3-TR mice, spatial memory in female apoE4-TR mice was impaired based on their poor performances in; (i) the probe test of the water-maze reference memory task, (ii) the water-maze working memory task and (iii) an active avoidance Y-maze task. Retention performance on a passive avoidance task was also impaired in apoE4-TR mice, but not in other genotypes. These deficits in both spatial and avoidance memory tasks may be related to the anatomical and functional abnormalities previously reported in the hippocampus and the amygdala of apoE4-TR mice. We conclude that the apoE4-TR mice provide an excellent model for understanding the mechanisms underlying apoE4-dependent susceptibility to cognitive decline.

Overexpression of human SOD1 improves survival of mice susceptible to endotoxic shock

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Charchaflieh J

2012-07-01

Full Text Available Jean Charchaflieh,1,2 Georges I Labaze,1 Pulsar Li,1 Holly Van Remmen,3 Haekyung Lee,1 Helen Stutz,1 Arlan Richardson,3 Asher Emanuel,1 Ming Zhang1,41Department of Anesthesiology, State University of New York (SUNY Downstate Medical Center, New York, NY, USA; 2Department of Anesthesiology, Yale University School of Medicine, New Haven, CT, USA; 3Barshop Center for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA; 4Department of Cell Biology, State University of New York (SUNY Downstate Medical Center, New York, NY, USABackground: Protective effects of the antioxidant enzyme Cu-Zn superoxide dismutase (SOD1 against endotoxic shock have not been demonstrated in animal models. We used a murine model to investigate whether overexpression of SOD1 protects against endotoxic shock, and whether the genetic background of SOD1 affects its effective protective effects and susceptibility to endotoxic shock.Methods: Transgenic (tg mice overexpressing human SOD1 and control mice were divided into four groups based on their genetic background: (1 tg mice with mixed genetic background (tg-JAX; (2 wild-type (WT littermates of tg-JAX strain (WT-JAX; (3 tg mice with C57BL/6J background (tg-TX; (4 WT littermates of tg-TX strain (WT-TX. Activity of SOD1 in the intestine, heart, and liver of tg and control mice was confirmed using a polyacrylamide activity gel. Endotoxic shock was induced by intraperitoneal injection of lipopolysaccharide. Survival rates over 120 hours (mean, 95% confidence interval were analyzed using Kaplan–Meier survival curves.Results: Human SOD1 enzymatic activities were significantly higher in the intestine, heart, and liver of both tg strains (tg-JAX and tg-TX compared with their WT littermates (WT-JAX and WT-TX, respectively. Interestingly, the endogenous SOD1 activities in tg-JAX mice were decreased compared with their WT littermates (WT-JAX, but such aberrant changes were not

Effect of bcl-2 overexpression in mice on ovotoxicity caused by 4-vinylcyclohexene

International Nuclear Information System (INIS)

Flaws, Jodi A.; Marion, Samuel L.; Miller, Kimberly P.; Christian, Patricia J.; Babus, Janice K.; Hoyer, Patricia B.

2006-01-01

The occupational chemical 4-vinylcyclohexene (VCH) destroys small preantral ovarian follicles in mice following repeated daily dosing. The cell survival gene bcl-2 is thought to protect against follicular death during embryogenesis because primordial follicle numbers in newborn bcl-2 overexpressing (OE) mice are greater than in wild-type (WT) controls. Thus, this study was designed to determine if overexpression of bcl-2 protects against VCH-induced follicle loss during embryonic development. Pregnant bcl-2 OE or WT mice were dosed (p.o.) daily with VCH (500 mg/kg) or sesame oil (vehicle control) on days 8-18 of pregnancy. Ovaries were collected from moms and female pups on pup postnatal day (PND) 8. Nonpregnant OE and WT females were also treated with VCH (500 mg/kg p.o.) or vehicle and evaluated in the same manner. As previously reported, ovaries from PND8 OE female pups contained 50% more primordial follicles than WT pups (P < 0.05). Unlike WT pups, relative to vehicle controls, in utero exposure to VCH resulted in a reduction in primordial (25% of control), primary (38% of control), and secondary (33% of control) follicles in ovaries of OE pups (P < 0.05). VCH had no significant effect on follicle numbers in OE or WT moms. Conversely, in nonpregnant adults, VCH did not affect WT mice but caused loss of primordial (55% of control), primary (51% of control), and secondary (69% of control) follicles in OE mice (P < 0.05). These results demonstrate that bcl-2 overexpression does not protect against, but instead increases susceptibility to VCH-induced follicle loss in transplacentally exposed or in nonpregnant mice

Glyoxalase 1 overexpression does not affect atherosclerotic lesion size and severity in ApoE-/- mice with or without diabetes

DEFF Research Database (Denmark)

Hanssen, Nordin M J; Brouwers, Olaf; Gijbels, Marion J

2014-01-01

are higher in rupture-prone plaques. We here investigated whether overexpression of human GLO1 in ApoE(-/-) mice could reduce the development of atherosclerosis. METHODS AND RESULTS: We crossed C57BL/6 ApoE(-/-) mice with C57BL/6 GLO1 overexpressing mice (huGLO1(+/-)) to generate ApoE(-/-) (n = 16) and Apo......E(-/-) huGLO1(+/-) (n = 20) mice. To induce diabetes, we injected a subset with streptozotocin (STZ) to generate diabetic ApoE(-/-) (n = 8) and ApoE(-/-) huGLO1(+/-) (n = 13) mice. All mice were fed chow and sacrificed at 25 weeks of age. The GLO1 activity was three-fold increased in huGLO1(+/-) aorta......, but aortic root lesion size and phenotype did not differ between mice with and without huGLO1(+/-) overexpression. We detected no differences in gene expression in aortic arches, in AGE levels and cytokines, in circulating cells, and endothelial function between ApoE(-/-) mice with and without huGLO1...

APP overexpression prevents neuropathic pain and motoneuron death after peripheral nerve injury in mice.

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Kotulska, Katarzyna; Larysz-Brysz, Magdalena; LePecheur, Marie; Marcol, Wiesław; Lewin-Kowalik, Joanna; Paly, Evelyn; London, Jacqueline

2010-03-16

Despite general capacity of peripheral nervous system to regenerate, peripheral nerve injury is often followed by incomplete recovery of function and sometimes burdened by neuropathic pain. Amyloid precursor protein (APP) was suggested to play a role in neuronal growth, however, its role in peripheral nerve repair was not studied. The aim of this study was to examine the role of APP overexpression in peripheral nerve regeneration and neuropathic pain-related behavior in mice. Sciatic nerves of APP overexpressing and FVB/N wild-type mice were transected and immediately resutured. Evaluation of motor and sensory function and autotomy was carried out during 4-week follow up. We found no autotomy behavior as well as less significant atrophy of denervated muscles in APP overexpressing animals when compared to wild-type ones. Sciatic nerve function index outcome did not differ between groups. Histological evaluation revealed that the intensity of regeneration features, including GAP-43-positive growth cones and Schwann cells number in the distal stump of the transected nerve, was also similar in both groups. However, the regenerating fibers were organized more chaotically in wild-type mice and neuromas were much more often seen in this group. The number of macrophages infiltrating the injury site was significantly higher in control group. The number of surviving motoneurons was higher in transgenic mice than in control animals. Taken together, our findings suggest that APP overexpression is beneficial for nerve regeneration processes due to better organization of regenerating fibers, increased survival of motoneurons after autotomy and prevention of neuropathic pain. Copyright 2009 Elsevier Inc. All rights reserved.

Cardiac-specific inducible overexpression of human plasma membrane Ca2+ ATPase 4b is cardioprotective and improves survival in mice following ischemic injury.

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Sadi, Al Muktafi; Afroze, Talat; Siraj, M Ahsan; Momen, Abdul; White-Dzuro, Colin; Zarrin-Khat, Dorrin; Handa, Shivalika; Ban, Kiwon; Kabir, M Golam; Trivieri, Maria G; Gros, Robert; Backx, Peter; Husain, Mansoor

2018-03-30

Background: Heart failure (HF) is associated with reduced expression of plasma membrane Ca 2+ -ATPase 4 (PMCA4). Cardiac-specific overexpression of human PMCA4b in mice inhibited nNOS activity and reduced cardiac hypertrophy by inhibiting calcineurin. Here we examine temporally regulated cardiac-specific overexpression of hPMCA4b in mouse models of myocardial ischemia reperfusion injury (IRI) ex vivo , and HF following experimental myocardial infarction (MI) in vivo Methods and results: Doxycycline-regulated cardiomyocyte-specific overexpression and activity of hPMCA4b produced adaptive changes in expression levels of Ca 2+ -regulatory genes, and induced hypertrophy without significant differences in Ca 2+ transients or diastolic Ca 2+ concentrations. Total cardiac NOS and nNOS-specific activities were reduced in mice with cardiac overexpression of hPMCA4b while nNOS, eNOS and iNOS protein levels did not differ. hMPCA4b-overexpressing mice also exhibited elevated systolic blood pressure vs. controls, with increased contractility and lusitropy in vivo In isolated hearts undergoing IRI, hPMCA4b overexpression was cardioprotective. NO donor-treated hearts overexpressing hPMCA4b showed reduced LVDP and larger infarct size versus vehicle-treated hearts undergoing IRI, demonstrating that the cardioprotective benefits of hPMCA4b-repressed nNOS are lost by restoring NO availability. Finally, both pre-existing and post-MI induction of hPMCA4b overexpression reduced infarct expansion and improved survival from HF. Conclusions: Cardiac PMCA4b regulates nNOS activity, cardiac mass and contractility, such that PMCA4b overexpression preserves cardiac function following IRI, heightens cardiac performance and limits infarct progression, cardiac hypertrophy and HF, even when induced late post-MI. These data identify PMCA4b as a novel therapeutic target for IRI and HF. © 2018 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

Striatal dopamine transmission is subtly modified in human A53Tα-synuclein overexpressing mice.

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Nicola J Platt

Full Text Available Mutations in, or elevated dosage of, SNCA, the gene for α-synuclein (α-syn, cause familial Parkinson's disease (PD. Mouse lines overexpressing the mutant human A53Tα-syn may represent a model of early PD. They display progressive motor deficits, abnormal cellular accumulation of α-syn, and deficits in dopamine-dependent corticostriatal plasticity, which, in the absence of overt nigrostriatal degeneration, suggest there are age-related deficits in striatal dopamine (DA signalling. In addition A53Tα-syn overexpression in cultured rodent neurons has been reported to inhibit transmitter release. Therefore here we have characterized for the first time DA release in the striatum of mice overexpressing human A53Tα-syn, and explored whether A53Tα-syn overexpression causes deficits in the release of DA. We used fast-scan cyclic voltammetry to detect DA release at carbon-fibre microelectrodes in acute striatal slices from two different lines of A53Tα-syn-overexpressing mice, at up to 24 months. In A53Tα-syn overexpressors, mean DA release evoked by a single stimulus pulse was not different from wild-types, in either dorsal striatum or nucleus accumbens. However the frequency responsiveness of DA release was slightly modified in A53Tα-syn overexpressors, and in particular showed slight deficiency when the confounding effects of striatal ACh acting at presynaptic nicotinic receptors (nAChRs were antagonized. The re-release of DA was unmodified after single-pulse stimuli, but after prolonged stimulation trains, A53Tα-syn overexpressors showed enhanced recovery of DA release at old age, in keeping with elevated striatal DA content. In summary, A53Tα-syn overexpression in mice causes subtle changes in the regulation of DA release in the striatum. While modest, these modifications may indicate or contribute to striatal dysfunction.

Tubular overexpression of gremlin induces renal damage susceptibility in mice.

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Alejandra Droguett

Full Text Available A growing number of patients are recognized worldwide to have chronic kidney disease. Glomerular and interstitial fibrosis are hallmarks of renal progression. However, fibrosis of the kidney remains an unresolved challenge, and its molecular mechanisms are still not fully understood. Gremlin is an embryogenic gene that has been shown to play a key role in nephrogenesis, and its expression is generally low in the normal adult kidney. However, gremlin expression is elevated in many human renal diseases, including diabetic nephropathy, pauci-immune glomerulonephritis and chronic allograft nephropathy. Several studies have proposed that gremlin may be involved in renal damage by acting as a downstream mediator of TGF-β. To examine the in vivo role of gremlin in kidney pathophysiology, we generated seven viable transgenic mouse lines expressing human gremlin (GREM1 specifically in renal proximal tubular epithelial cells under the control of an androgen-regulated promoter. These lines demonstrated 1.2- to 200-fold increased GREM1 expression. GREM1 transgenic mice presented a normal phenotype and were without proteinuria and renal function involvement. In response to the acute renal damage cause by folic acid nephrotoxicity, tubule-specific GREM1 transgenic mice developed increased proteinuria after 7 and 14 days compared with wild-type treated mice. At 14 days tubular lesions, such as dilatation, epithelium flattening and hyaline casts, with interstitial cell infiltration and mild fibrosis were significantly more prominent in transgenic mice than wild-type mice. Tubular GREM1 overexpression was correlated with the renal upregulation of profibrotic factors, such as TGF-β and αSMA, and with increased numbers of monocytes/macrophages and lymphocytes compared to wild-type mice. Taken together, our results suggest that GREM1-overexpressing mice have an increased susceptibility to renal damage, supporting the involvement of gremlin in renal damage

Characterisation of the nociceptive phenotype of suppressible galanin overexpressing transgenic mice

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Wynick David

2010-10-01

Full Text Available Abstract The neuropeptide galanin is widely expressed in both the central and peripheral nervous systems and is involved in many diverse biological functions. There is a substantial data set that demonstrates galanin is upregulated after injury in the DRG, spinal cord and in many brain regions where it plays a predominantly antinociceptive role in addition to being neuroprotective and pro-regenerative. To further characterise the role of galanin following nerve injury, a novel transgenic line was created using the binary transgenic tet-off system, to overexpress galanin in galaninergic tissue in a suppressible manner. The double transgenic mice express significantly more galanin in the DRG one week after sciatic nerve section (axotomy compared to WT mice and this overexpression is suppressible upon administration of doxycycline. Phenotypic analysis revealed markedly attenuated allodynia when galanin is overexpressed and an increase in allodynia following galanin suppression. This novel transgenic line demonstrates that whether galanin expression is increased at the time of nerve injury or only after allodynia is established, the neuropeptide is able to reduce neuropathic pain behaviour. These new findings imply that administration of a galanin agonist to patients with established allodynia would be an effective treatment for neuropathic pain.

TREM2 Overexpression has No Improvement on Neuropathology and Cognitive Impairment in Aging APPswe/PS1dE9 Mice.

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Jiang, Teng; Wan, Yu; Zhang, Ying-Dong; Zhou, Jun-Shan; Gao, Qing; Zhu, Xi-Chen; Shi, Jian-Quan; Lu, Huan; Tan, Lan; Yu, Jin-Tai

2017-03-01

Previously, we showed that overexpression of triggering receptor expressed on myeloid cells 2 (TREM2), a microglia-specific immune receptor, in the brain of a middle-aged (7 months old) APPswe/PS1dE9 mice could ameliorate Alzheimer's disease (AD)-related neuropathology by enhancement of microglial amyloid-β (Aβ) phagocytosis. Since AD is an age-related neurodegenerative disorder, it is critical to assess the efficacy of TREM2 overexpression in aging animals with an advanced disease stage. In vivo, we employed a lentiviral strategy to overexpress TREM2 in the brain of aging (18 months old) APPswe/PS1dE9 mice, and observed its efficacy on AD-related neuropathology and cognitive functions. Afterwards, we directly isolated microglia from middle-aged and aging APPswe/PS1dE9 mice and determined effects of TREM2 overexpression on microglial Aβ phagocytosis and Aβ-binding receptors expression in vitro. In aging APPswe/PS1dE9 mice, TREM2 overexpression has no beneficial effect on AD-related neuropathology and spatial cognitive functions. Of note, in vitro experiments showed a significant reduction of Aβ phagocytosis in microglia from aging APPswe/PS1dE9 mice, possibly attributing to the declined expression of Aβ-binding receptors. Meanwhile, this phagocytic deficit in microglia from aging APPswe/PS1dE9 mice cannot be rescued by TREM2 overexpression. Taken together, our study shows that TREM2 overexpression fails to provide neuroprotection in aging APPswe/PS1dE9 mice, possibly attributing to deficits in microglial Aβ phagocytosis at the late-stage of disease progression. These findings indicate that TREM2-mediated protection in AD is at least partially dependent on the reservation of microglial phagocytic functions, emphasizing the importance of early therapeutic interventions for this devastating disease.

Mammary gland tumor formation in transgenic mice overexpressing stromelysin-1

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Sympson, Carolyn J; Bissell, Mina J; Werb, Zena

1995-06-01

An intact basement membrane (BM) is essential for the proper function, differentiation and morphology of many epithelial cells. The disruption or loss of this BM occurs during normal development as well as in the disease state. To examine the importance of BM during mammary gland development in vivo, we generated transgenic mice that inappropriately express autoactivating isoforms of the matrix metalloproteinase stromelysin-1. The mammary glands from these mice are both functionally and morphologically altered throughout development. We have now documented a dramatic incidence of breast tumors in several independent lines of these mice. These data suggest that overexpression of stromelysin-1 and disruption of the BM may be a key step in the multi-step process of breast cancer.

Working Memory Deficits, Increased Anxiety-Like Traits, and Seizure Susceptibility in BDNF Overexpressing Mice

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Papaleo, Francesco; Silverman, Jill L.; Aney, Jordan; Tian, Qingjun; Barkan, Charlotte L.; Chadman, Kathryn K.; Crawley, Jacqueline N.

2011-01-01

BDNF regulates components of cognitive processes and has been implicated in psychiatric disorders. Here we report that genetic overexpression of the BDNF mature isoform (BDNF-tg) in female mice impaired working memory functions while sparing components of fear conditioning. BDNF-tg mice also displayed reduced breeding efficiency, higher…

Astrocyte-Specific Overexpression of Insulin-Like Growth Factor-1 Protects Hippocampal Neurons and Reduces Behavioral Deficits following Traumatic Brain Injury in Mice.

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Sindhu K Madathil

Full Text Available Traumatic brain injury (TBI survivors often suffer from long-lasting cognitive impairment that stems from hippocampal injury. Systemic administration of insulin-like growth factor-1 (IGF-1, a polypeptide growth factor known to play vital roles in neuronal survival, has been shown to attenuate posttraumatic cognitive and motor dysfunction. However, its neuroprotective effects in TBI have not been examined. To this end, moderate or severe contusion brain injury was induced in mice with conditional (postnatal overexpression of IGF-1 using the controlled cortical impact (CCI injury model. CCI brain injury produces robust reactive astrocytosis in regions of neuronal damage such as the hippocampus. We exploited this regional astrocytosis by linking expression of hIGF-1 to the astrocyte-specific glial fibrillary acidic protein (GFAP promoter, effectively targeting IGF-1 delivery to vulnerable neurons. Following brain injury, IGF-1Tg mice exhibited a progressive increase in hippocampal IGF-1 levels which was coupled with enhanced hippocampal reactive astrocytosis and significantly greater GFAP levels relative to WT mice. IGF-1 overexpression stimulated Akt phosphorylation and reduced acute (1 and 3d hippocampal neurodegeneration, culminating in greater neuron survival at 10d after CCI injury. Hippocampal neuroprotection achieved by IGF-1 overexpression was accompanied by improved motor and cognitive function in brain-injured mice. These data provide strong support for the therapeutic efficacy of increased brain levels of IGF-1 in the setting of TBI.

Astrocyte-Specific Overexpression of Insulin-Like Growth Factor-1 Protects Hippocampal Neurons and Reduces Behavioral Deficits following Traumatic Brain Injury in Mice

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Madathil, Sindhu K.; Carlson, Shaun W.; Brelsfoard, Jennifer M.; Ye, Ping; D’Ercole, A. Joseph; Saatman, Kathryn E.

2013-01-01

Traumatic brain injury (TBI) survivors often suffer from long-lasting cognitive impairment that stems from hippocampal injury. Systemic administration of insulin-like growth factor-1 (IGF-1), a polypeptide growth factor known to play vital roles in neuronal survival, has been shown to attenuate posttraumatic cognitive and motor dysfunction. However, its neuroprotective effects in TBI have not been examined. To this end, moderate or severe contusion brain injury was induced in mice with conditional (postnatal) overexpression of IGF-1 using the controlled cortical impact (CCI) injury model. CCI brain injury produces robust reactive astrocytosis in regions of neuronal damage such as the hippocampus. We exploited this regional astrocytosis by linking expression of hIGF-1 to the astrocyte-specific glial fibrillary acidic protein (GFAP) promoter, effectively targeting IGF-1 delivery to vulnerable neurons. Following brain injury, IGF-1Tg mice exhibited a progressive increase in hippocampal IGF-1 levels which was coupled with enhanced hippocampal reactive astrocytosis and significantly greater GFAP levels relative to WT mice. IGF-1 overexpression stimulated Akt phosphorylation and reduced acute (1 and 3d) hippocampal neurodegeneration, culminating in greater neuron survival at 10d after CCI injury. Hippocampal neuroprotection achieved by IGF-1 overexpression was accompanied by improved motor and cognitive function in brain-injured mice. These data provide strong support for the therapeutic efficacy of increased brain levels of IGF-1 in the setting of TBI. PMID:23826235

Macrophage overexpression of matrix metalloproteinase-9 in aged mice improves diastolic physiology and cardiac wound healing after myocardial infarction.

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Meschiari, Cesar A; Jung, Mira; Iyer, Rugmani Padmanabhan; Yabluchanskiy, Andriy; Toba, Hiroe; Garrett, Michael R; Lindsey, Merry L

2018-02-01

Matrix metalloproteinase (MMP)-9 increases in the myocardium with advanced age and after myocardial infarction (MI). Because young transgenic (TG) mice overexpressing human MMP-9 only in macrophages show better outcomes post-MI, whereas aged TG mice show a worse aging phenotype, we wanted to evaluate the effect of aging superimposed on MI to see if the detrimental effect of aging counteracted the benefits of macrophage MMP-9 overexpression. We used 17- to 28-mo-old male and female C57BL/6J wild-type (WT) and TG mice ( n = 10-21 mice/group) to evaluate the effects of aging superimposed on MI. Despite similar infarct areas and mortality rates at day 7 post-MI, aging TG mice showed improved diastolic properties and remodeling index compared with WT mice (both P wound healing through direct and indirect mechanisms to improve diastolic physiology and remodeling. NEW & NOTEWORTHY Aging mice with macrophage overexpression of matrix metalloproteinase-9 have increased macrophage numbers 7 days after myocardial infarction, resulting in improved diastolic physiology and left ventricular remodeling through effects on cardiac wound healing.

Overexpression of microRNA-26a protects against deficient β-cell function via targeting phosphatase with tensin homology in mouse models of type 2 diabetes.

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Song, Yingli; Jin, Di; Jiang, Xiaoshu; Lv, Chunmei; Zhu, Hui

2018-01-01

The prevalence of type 2 diabetes mellitus (T2DM) increased rapidly in the world. The development of β-cell dysfunction is the quintessential defects in T2DM patients However, the pathogenesis of β-cell dysfunction is still unclear. MicroRNAs are short non-coding RNAs and has been reported to be involved in pathogenesis of β-cell dysfunction and T2DM. Here, we investigated the mechanisms by which miR-26a regulate β-cell function and insulin signaling pathway in high fat diet (HFD) fed and db/db T2DM mice model. The expression of miR-26a was down-regulated dramatically in the serum and islets of both HFD and db/db mice model. miR-26a overexpression protected against HFD-induced diabetes and maintained prolonged normoglycemic time in HFD fed mice. Overexpression of miR-26a improved β-cell dysfunction in T2DM mice. Further, we identified that PTEN is a direct target gene of miR-26a. Overexpression of miR-26a significantly inhibited the luciferase activity of hPTEN 3'-UTR, while the effect of miR-26a disappeared when the miR-26a potential binding site within the PTEN 3'-UTR was mutated. Overexpression of miR-26a reduced both the mRNA and protein levels of PTEN in vitro and in vivo. We also found that miR-26a overexpression increased the expression of p-Akt and p-FoxO-1, while the effect of miR-26a was blocked by PTEN overexpression. In conclusion, our data indicated that miR-26a potentially contributes to the β-cell dysfunction in T2DM, and miR-26a may be a new therapeutic strategy against T2DM. Copyright © 2017 Elsevier Inc. All rights reserved.

Overexpression of CCS in G93A-SOD1 mice leads to accelerated neurological deficits with severe mitochondrial pathology.

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Son, Marjatta; Puttaparthi, Krishna; Kawamata, Hibiki; Rajendran, Bhagya; Boyer, Philip J; Manfredi, Giovanni; Elliott, Jeffrey L

2007-04-03

Cu, Zn superoxide dismutase (SOD1) has been detected within spinal cord mitochondria of mutant SOD1 transgenic mice, a model of familial ALS. The copper chaperone for SOD1 (CCS) provides SOD1 with copper, facilitates the conversion of immature apo-SOD1 to a mature holoform, and influences in yeast the cytosolic/mitochondrial partitioning of SOD1. To determine how CCS affects G93A-SOD1-induced disease, we generated transgenic mice overexpressing CCS and crossed them to G93A-SOD1 or wild-type SOD1 transgenic mice. Both CCS transgenic mice and CCS/wild-type-SOD1 dual transgenic mice are neurologically normal. In contrast, CCS/G93A-SOD1 dual transgenic mice develop accelerated neurological deficits, with a mean survival of 36 days, compared with 242 days for G93A-SOD1 mice. Immuno-EM and subcellular fractionation studies on the spinal cord show that G93A-SOD1 is enriched within mitochondria in the presence of CCS overexpression. Our results indicate that CCS overexpression in G93A-SOD1 mice produces severe mitochondrial pathology and accelerates disease course.

Small heterodimer partner overexpression partially protects against liver tumor development in farnesoid X receptor knockout mice

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Li, Guodong; Kong, Bo; Zhu, Yan; Zhan, Le; Williams, Jessica A.; Tawfik, Ossama; Kassel, Karen M.; Luyendyk, James P.; Wang, Li; Guo, Grace L.

2013-01-01

Farnesoid X receptor (FXR, Nr1h4) and small heterodimer partner (SHP, Nr0b2) are nuclear receptors that are critical to liver homeostasis. Induction of SHP serves as a major mechanism of FXR in suppressing gene expression. Both FXR −/− and SHP −/− mice develop spontaneous hepatocellular carcinoma (HCC). SHP is one of the most strongly induced genes by FXR in the liver and is a tumor suppressor, therefore, we hypothesized that deficiency of SHP contributes to HCC development in the livers of FXR −/− mice and therefore, increased SHP expression in FXR −/− mice reduces liver tumorigenesis. To test this hypothesis, we generated FXR −/− mice with overexpression of SHP in hepatocytes (FXR −/− /SHP Tg ) and determined the contribution of SHP in HCC development in FXR −/− mice. Hepatocyte-specific SHP overexpression did not affect liver tumor incidence or size in FXR −/− mice. However, SHP overexpression led to a lower grade of dysplasia, reduced indicator cell proliferation and increased apoptosis. All tumor-bearing mice had increased serum bile acid levels and IL-6 levels, which was associated with activation of hepatic STAT3. In conclusion, SHP partially protects FXR −/− mice from HCC formation by reducing tumor malignancy. However, disrupted bile acid homeostasis by FXR deficiency leads to inflammation and injury, which ultimately results in uncontrolled cell proliferation and tumorigenesis in the liver. - Highlights: • SHP does not prevent HCC incidence nor size in FXR KO mice but reduces malignancy. • Increased SHP promotes apoptosis. • Bile acids and inflammation maybe critical for HCC formation with FXR deficiency

Neuronal erythropoietin overexpression is protective against kanamycin-induced hearing loss in mice.

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Bächinger, David; Horvath, Lukas; Eckhard, Andreas; Goosmann, Madeline M; Honegger, Tim; Gassmann, Max; Vogel, Johannes; Naldi, Arianne Monge

2018-07-01

Aminoglycosides have detrimental effects on the hair cells of the inner ear, yet these agents indisputably are one of the cornerstones in antibiotic therapy. Hence, there is a demand for strategies to prevent aminoglycoside-induced ototoxicity, which are not available today. In vitro data suggests that the pleiotropic growth factor erythropoietin (EPO) is neuroprotective against aminoglycoside-induced hair cell loss. Here, we use a mouse model with EPO-overexpression in neuronal tissue to evaluate whether EPO could also in vivo protect from aminoglycoside-induced hearing loss. Auditory brainstem response (ABR) thresholds were measured in 12-weeks-old mice before and after treatment with kanamycin for 15 days, which resulted in both C57BL/6 and EPO-transgenic animals in a high-frequency hearing loss. However, ABR threshold shifts in EPO-transgenic mice were significantly lower than in C57BL/6 mice (mean difference in ABR threshold shift 13.6 dB at 32 kHz, 95% CI 3.8-23.4 dB, p = 0.003). Correspondingly, quantification of hair cells and spiral ganglion neurons by immunofluorescence revealed that EPO-transgenic mice had a significantly lower hair cell and spiral ganglion neuron loss than C57BL/6 mice. In conclusion, neuronal overexpression of EPO is protective against aminoglycoside-induce hearing loss, which is in accordance with its known neuroprotective effects in other organs, such as the eye or the brain. Copyright © 2018 Elsevier B.V. All rights reserved.

Trichostatin A suppresses lung adenocarcinoma development in Grg1 overexpressing transgenic mice

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Liu, Ju; Li, Yan; Dong, Fengyun; Li, Liqun; Masuda, Takahiro; Allen, Thaddeus D.; Lobe, Corrinne G.

2015-01-01

Trichostatin A (TSA) is a histone deacetylase inhibitor and a potential therapeutic for various malignancies. The in vivo effect of TSA, however, has not been investigated in a transgenic lung cancer model. Previously, we generated transgenic mice with overexpression of Groucho-related-gene 1 (Grg1) and these mice all developed mucinous lung adenocarcinoma. Grg1 is a transcriptional co-repressor protein, the function of which is thought to depend on HDAC activity. However, functions outside the nucleus have also been proposed. We tested the supposition that Grg1-induced tumorigenesis is HDAC-dependent by assaying the therapeutic effect of TSA in the Grg1 transgenic mouse model. We found that TSA significantly inhibited lung tumorigenesis in Grg1 transgenic mice (p < 0.01). TSA did not affect overall Grg1 protein levels, but instead reduced ErbB1 and ErbB2 expression, which are upregulated by Grg1 in the absence of TSA. We confirmed this effect in A549 cells. Furthermore, lapatinib, an inhibitor of both ErbB1 and ErbB2, effectively masked the effect of TSA on the inhibition of A549 cell proliferation and migration, suggesting TSA does work, at least in part, by downregulating ErbB receptors. We additionally found that TSA reduced the expression of VEGF and VEGFR2, but not basic FGF and FGFR1. Our findings indicate that TSA effectively inhibits Grg1-induced lung tumorigenesis through the down-regulation of ErbB1 and ErbB2, as well as reduced VEGF signaling. This suggests TSA and other HDAC inhibitors could have therapeutic value in the treatment of lung cancers with Grg1 overexpression. - Highlights: • TSA suppresses lung tumorigenesis in Grg1 overexpressing transgenic mice. • TSA does not affect overall Grg1 protein levels in the mice and in A549 cells. • TSA reduces ErbB1 and ErbB2 expression in the mice and in A549 cells. • Lapatinib masks TSA-induced inhibition of A549 cell proliferation and migration. • TSA inhibits VEGF signaling, but not basic FGF

Trichostatin A suppresses lung adenocarcinoma development in Grg1 overexpressing transgenic mice

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Liu, Ju, E-mail: ju.liu@sdu.edu.cn [Medical Research Center, Shandong Provincial Qianfoshan Hospital, Shandong University, 16766 Jingshi Road, Jinan (China); Molecular and Cellular Biology Division, Sunnybrook Health Science Centre, University of Toronto, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5 (Canada); Li, Yan [Children' s Health Care Center, Shandong Provincial Qianfoshan Hospital, Shandong University, 16766 Jingshi Road, Jinan, Shandong 250014 (China); Dong, Fengyun; Li, Liqun [Medical Research Center, Shandong Provincial Qianfoshan Hospital, Shandong University, 16766 Jingshi Road, Jinan (China); Masuda, Takahiro; Allen, Thaddeus D. [Molecular and Cellular Biology Division, Sunnybrook Health Science Centre, University of Toronto, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5 (Canada); Lobe, Corrinne G. [Molecular and Cellular Biology Division, Sunnybrook Health Science Centre, University of Toronto, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5 (Canada); Miami Mice Research Corp., MaRS Centre, Heritage Bldg., 101 College Street, Toronto, Ontario M5G 1L7 (Canada)

2015-08-07

Trichostatin A (TSA) is a histone deacetylase inhibitor and a potential therapeutic for various malignancies. The in vivo effect of TSA, however, has not been investigated in a transgenic lung cancer model. Previously, we generated transgenic mice with overexpression of Groucho-related-gene 1 (Grg1) and these mice all developed mucinous lung adenocarcinoma. Grg1 is a transcriptional co-repressor protein, the function of which is thought to depend on HDAC activity. However, functions outside the nucleus have also been proposed. We tested the supposition that Grg1-induced tumorigenesis is HDAC-dependent by assaying the therapeutic effect of TSA in the Grg1 transgenic mouse model. We found that TSA significantly inhibited lung tumorigenesis in Grg1 transgenic mice (p < 0.01). TSA did not affect overall Grg1 protein levels, but instead reduced ErbB1 and ErbB2 expression, which are upregulated by Grg1 in the absence of TSA. We confirmed this effect in A549 cells. Furthermore, lapatinib, an inhibitor of both ErbB1 and ErbB2, effectively masked the effect of TSA on the inhibition of A549 cell proliferation and migration, suggesting TSA does work, at least in part, by downregulating ErbB receptors. We additionally found that TSA reduced the expression of VEGF and VEGFR2, but not basic FGF and FGFR1. Our findings indicate that TSA effectively inhibits Grg1-induced lung tumorigenesis through the down-regulation of ErbB1 and ErbB2, as well as reduced VEGF signaling. This suggests TSA and other HDAC inhibitors could have therapeutic value in the treatment of lung cancers with Grg1 overexpression. - Highlights: • TSA suppresses lung tumorigenesis in Grg1 overexpressing transgenic mice. • TSA does not affect overall Grg1 protein levels in the mice and in A549 cells. • TSA reduces ErbB1 and ErbB2 expression in the mice and in A549 cells. • Lapatinib masks TSA-induced inhibition of A549 cell proliferation and migration. • TSA inhibits VEGF signaling, but not basic FGF

Dissociation of hepatic steatosis and insulin resistance in mice overexpressing DGAT in the liver.

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Monetti, Mara; Levin, Malin C; Watt, Matthew J; Sajan, Mini P; Marmor, Stephen; Hubbard, Brian K; Stevens, Robert D; Bain, James R; Newgard, Christopher B; Farese, Robert V; Hevener, Andrea L; Farese, Robert V

2007-07-01

Hepatic steatosis, the accumulation of lipids in the liver, is widely believed to result in insulin resistance. To test the causal relationship between hepatic steatosis and insulin resistance, we generated mice that overexpress acyl-CoA:diacylglycerol acyltransferase 2 (DGAT2), which catalyzes the final step of triacylglycerol (TG) biosynthesis, in the liver (Liv-DGAT2 mice). Liv-DGAT2 mice developed hepatic steatosis, with increased amounts of TG, diacylglycerol, ceramides, and unsaturated long-chain fatty acyl-CoAs in the liver. However, they had no abnormalities in plasma glucose and insulin levels, glucose and insulin tolerance, rates of glucose infusion and hepatic glucose production during hyperinsulinemic-euglycemic clamp studies, or activities of insulin-stimulated signaling proteins in the liver. DGAT1 overexpression in the liver also failed to induce glucose or insulin intolerance. Our results indicate that DGAT-mediated lipid accumulation in the liver is insufficient to cause insulin resistance and show that hepatic steatosis can occur independently of insulin resistance.

Transgenic Mice Overexpressing Vitamin D Receptor (VDR) Show Anti-Inflammatory Effects in Lung Tissues.

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Ishii, Masaki; Yamaguchi, Yasuhiro; Isumi, Kyoko; Ogawa, Sumito; Akishita, Masahiro

2017-12-01

Vitamin D insufficiency is increasingly recognized as a prevalent problem worldwide, especially in patients with a chronic lung disease. Chronic obstructive pulmonary disease (COPD) is a type of chronic inflammatory lung disease. Previous clinical studies have shown that COPD leads to low vitamin D levels, which further increase the severity of COPD. Vitamin D homeostasis represents one of the most important factors that potentially determine the severity of COPD. Nonetheless, the mechanisms underlying the anti-inflammatory effects of vitamin D receptor (VDR) in lung tissues are still unclear. To investigate the anti-inflammatory effects of VDR, we generated transgenic mice that show lung-specific VDR overexpression under the control of the surfactant protein C promoter (TG mice). The TG mice were used to study the expression patterns of proinflammatory cytokines using real-time polymerase chain reaction and immunohistochemistry. The TG mice had lower levels of T helper 1 (Th1)-related cytokines than wild-type (WT) mice did. No significant differences in the expression of Th2 cytokines were observed between TG and WT mice. This study is the first to achieve lung-specific overexpression of VDR in TG mice: an interesting animal model useful for studying the relation between airway cell inflammation and vitamin D signaling. VDR expression is an important factor that influences anti-inflammatory responses in lung tissues. Our results show the crucial role of VDR in anti-inflammatory effects in lungs; these data are potentially useful for the treatment or prevention of COPD.

Overexpression of PTPN2 in Visceral Adipose Tissue Ameliorated Atherosclerosis via T Cells Polarization Shift in Diabetic Apoe-/- Mice

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Ya Li

2018-03-01

Full Text Available Background/Aims: Dysregulated inflammation in adipose tissue, marked by increased pro-inflammatory T-cell accumulation and reduced regulatory T cells (Treg, contributes to diabetes-associated insulin resistance and atherosclerosis. However, the molecular mechanisms underlying T-cell-mediated inflammation in adipose tissue remain largely unknown. Methods: Sixty apolipoprotein E (ApoE-/- mice were randomly divided into chow and diabetes groups. Diabetes was induced by a high-fat and high-sugar diet combined with low-dose streptozotocin. Then we transferred a recombinant adenovirus carrying the protein tyrosine phosphatase non-receptor type 2 (PTPN2 gene into epididymal white adipose tissue (EWAT of ApoE-/- mice. After transfection, all mice were euthanized to evaluate the effects of PTPN2 on T cells polarization and atherosclerosis. Results: PTPN2 was downregulated in EWAT of diabetic ApoE-/- mice. PTPN2 overexpression in EWAT reversed the high Th1/Treg and Th17/Treg ratios in EWAT of diabetic mice. In addition, PTPN2 overexpression in EWAT could significantly reduce macrophages infiltration, the ratio of M1/M2 macrophages and the expression of pro-inflammatory cytokines in EWAT, improving insulin resistance. In aortic root lesions, the vulnerability index were significantly decreased by overexpression of PTPN2 in EWAT. Conclusion: These data suggested that PTPN2 overexpression in EWAT would inhibit systemic inflammation and increase the plaque stability via T cells polarization shift in diabetic mice.

FHL1 reduces dystrophy in transgenic mice overexpressing FSHD muscular dystrophy region gene 1 (FRG1.

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Sandra J Feeney

Full Text Available Facioscapulohumeral muscular dystrophy (FSHD is an autosomal-dominant disease with no effective treatment. The genetic cause of FSHD is complex and the primary pathogenic insult underlying the muscle disease is unknown. Several disease candidate genes have been proposed including DUX4 and FRG1. Expression analysis studies of FSHD report the deregulation of genes which mediate myoblast differentiation and fusion. Transgenic mice overexpressing FRG1 recapitulate the FSHD muscular dystrophy phenotype. Our current study selectively examines how increased expression of FRG1 may contribute to myoblast differentiation defects. We generated stable C2C12 cell lines overexpressing FRG1, which exhibited a myoblast fusion defect upon differentiation. To determine if myoblast fusion defects contribute to the FRG1 mouse dystrophic phenotype, this strain was crossed with skeletal muscle specific FHL1-transgenic mice. We previously reported that FHL1 promotes myoblast fusion in vitro and FHL1-transgenic mice develop skeletal muscle hypertrophy. In the current study, FRG1 mice overexpressing FHL1 showed an improvement in the dystrophic phenotype, including a reduced spinal kyphosis, increased muscle mass and myofiber size, and decreased muscle fibrosis. FHL1 expression in FRG1 mice, did not alter satellite cell number or activation, but enhanced myoblast fusion. Primary myoblasts isolated from FRG1 mice showed a myoblast fusion defect that was rescued by FHL1 expression. Therefore, increased FRG1 expression may contribute to a muscular dystrophy phenotype resembling FSHD by impairing myoblast fusion, a defect that can be rescued by enhanced myoblast fusion via expression of FHL1.

Endothelin-1 overexpression exacerbates atherosclerosis and induces aortic aneurysms in apolipoprotein E knockout mice.

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Li, Melissa W; Mian, Muhammad Oneeb Rehman; Barhoumi, Tlili; Rehman, Asia; Mann, Koren; Paradis, Pierre; Schiffrin, Ernesto L

2013-10-01

Endothelin (ET)-1 plays a role in vascular reactive oxygen species production and inflammation. ET-1 has been implicated in human atherosclerosis and abdominal aortic aneurysm (AAA) development. ET-1 overexpression exacerbates high-fat diet-induced atherosclerosis in apolipoprotein E(-/-) (Apoe(-/-)) mice. ET-1-induced reactive oxygen species and inflammation may contribute to atherosclerosis progression and AAA development. Eight-week-old male wild-type mice, transgenic mice overexpressing ET-1 selectively in endothelium (eET-1), Apoe(-/-) mice, and eET-1/Apoe(-/-) mice were fed high-fat diet for 8 weeks. eET-1/Apoe(-/-) had a 45% reduction in plasma high-density lipoprotein (P<0.05) and presented ≥ 2-fold more aortic atherosclerotic lesions compared with Apoe(-/-) (P<0.01). AAAs were detected only in eET-1/Apoe(-/-) (8/21; P<0.05). Reactive oxygen species production was increased ≥ 2-fold in perivascular fat, media, or atherosclerotic lesions in the ascending aorta and AAAs of eET-1/Apoe(-/-) compared with Apoe(-/-) (P<0.05). Monocyte/macrophage infiltration was enhanced ≥ 2.5-fold in perivascular fat of ascending aorta and AAAs in eET-1/Apoe(-/-) compared with Apoe(-/-) (P<0.05). CD4(+) T cells were detected almost exclusively in perivascular fat (3/6) and atherosclerotic lesions (5/6) in ascending aorta of eET-1/Apoe(-/-) (P<0.05). The percentage of spleen proinflammatory Ly-6C(hi) monocytes was enhanced 26% by ET-1 overexpression in Apoe(-/-) (P<0.05), and matrix metalloproteinase-2 was increased 2-fold in plaques of eET-1/Apoe(-/-) (P<0.05) compared with Apoe(-/-). ET-1 plays a role in progression of atherosclerosis and AAA formation by decreasing high-density lipoprotein, and increasing oxidative stress, inflammatory cell infiltration, and matrix metalloproteinase-2 in perivascular fat, vascular wall, and atherosclerotic lesions.

Oxidized SOD1 alters proteasome activities in vitro and in the cortex of SOD1 overexpressing mice.

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Le Pecheur, Marie; Bourdon, Emmanuel; Paly, Evelyne; Farout, Luc; Friguet, Bertrand; London, Jacqueline

2005-07-04

Premature ageing, one of the characteristics of Down syndrome (DS), may involve oxidative stress and impairment of proteasome activity. Transgenic mice overexpressing the human copper/zinc superoxide dismutase (SOD1) gene are one of the first murine models for DS and it has been shown that SOD1 overexpression might be either deleterious or beneficial. Here, we show a reduction in proteasome activities in the cortex of SOD1 transgenic mice and an associated increase in the content of oxidized SOD1 protein. As we demonstrate that in vitro oxidized SOD can inhibit purified proteasome peptidase activities, modified SOD1 might be partially responsible for proteasome inhibition shown in SOD1 transgenic mice.

Compensation of the AKT signaling by ERK signaling in transgenic mice hearts overexpressing TRIM72

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Ham, Young-Mi, E-mail: youngmi_ham@hms.harvard.edu [College of Life Science and Biotechnology, Korea University, Seoul (Korea, Republic of); Department of Cell Biology, Harvard Medical School, Boston, MA 02115 (United States); Mahoney, Sarah Jane [Department of Cell Biology, Harvard Medical School, Boston, MA 02115 (United States)

2013-06-10

The AKT and ERK signaling pathways are known to be involved in cell hypertrophy, proliferation, survival and differentiation. Although there is evidence for crosstalk between these two signaling pathways in cellulo, there is less evidence for cross talk in vivo. Here, we show that crosstalk between AKT and ERK signaling in the hearts of TRIM72-overexpressing transgenic mice (TRIM72-Tg) with alpha-MHC promoter regulates and maintains their heart size. TRIM72, a heart- and skeletal muscle-specific protein, downregulates AKT-mTOR signaling via IRS-1 degradation and reduces the size of rat cardiomyocytes and the size of postnatal TRIM72-Tg hearts. TRIM72 expression was upregulated by hypertrophic inducers in cardiomyocytes, while IRS-1 was downregulated by IGF-1. TRIM72 specifically regulated IGF-1-dependent AKT-mTOR signaling, resulting in a reduction of the size of cardiomyocytes. Postnatal TRIM72-Tg hearts were smaller than control-treated hearts with inhibition of AKT-mTOR signaling. However, adult TRIM72-Tg hearts were larger than of control despite the suppression of AKT-mTOR signaling. Activation of ERK, PKC-α, and JNK were observed to be elevated in adult TRIM72-Tg, and these signals were mediated by ET-1 via the ET receptors A and B. Altogether, these results suggest that AKT signaling regulates cardiac hypertrophy in physiological conditions, and ERK signaling compensates for the absence of AKT signaling during TRIM72 overexpression, leading to pathological hypertrophy. -- Highlights: • TRIM72 inhibits AKT signaling through ubiquitination of IRS-1 in cardiac cells. • TRIM72 regulates the size of cardiac cells. • TRIM72 regulates size of postnatal TRIM72-overexpressing transgenic mice hearts. • Adult TRIM72-overexpressing transgenic mice hearts showed cardiac dysfunction. • Adult TRIM72 transgenic mice hearts showed higher expression of endothelin receptors.

Compensation of the AKT signaling by ERK signaling in transgenic mice hearts overexpressing TRIM72

International Nuclear Information System (INIS)

Ham, Young-Mi; Mahoney, Sarah Jane

2013-01-01

The AKT and ERK signaling pathways are known to be involved in cell hypertrophy, proliferation, survival and differentiation. Although there is evidence for crosstalk between these two signaling pathways in cellulo, there is less evidence for cross talk in vivo. Here, we show that crosstalk between AKT and ERK signaling in the hearts of TRIM72-overexpressing transgenic mice (TRIM72-Tg) with alpha-MHC promoter regulates and maintains their heart size. TRIM72, a heart- and skeletal muscle-specific protein, downregulates AKT-mTOR signaling via IRS-1 degradation and reduces the size of rat cardiomyocytes and the size of postnatal TRIM72-Tg hearts. TRIM72 expression was upregulated by hypertrophic inducers in cardiomyocytes, while IRS-1 was downregulated by IGF-1. TRIM72 specifically regulated IGF-1-dependent AKT-mTOR signaling, resulting in a reduction of the size of cardiomyocytes. Postnatal TRIM72-Tg hearts were smaller than control-treated hearts with inhibition of AKT-mTOR signaling. However, adult TRIM72-Tg hearts were larger than of control despite the suppression of AKT-mTOR signaling. Activation of ERK, PKC-α, and JNK were observed to be elevated in adult TRIM72-Tg, and these signals were mediated by ET-1 via the ET receptors A and B. Altogether, these results suggest that AKT signaling regulates cardiac hypertrophy in physiological conditions, and ERK signaling compensates for the absence of AKT signaling during TRIM72 overexpression, leading to pathological hypertrophy. -- Highlights: • TRIM72 inhibits AKT signaling through ubiquitination of IRS-1 in cardiac cells. • TRIM72 regulates the size of cardiac cells. • TRIM72 regulates size of postnatal TRIM72-overexpressing transgenic mice hearts. • Adult TRIM72-overexpressing transgenic mice hearts showed cardiac dysfunction. • Adult TRIM72 transgenic mice hearts showed higher expression of endothelin receptors

Preservation of endothelium-dependent relaxation in atherosclerotic mice with endothelium-restricted endothelin-1 overexpression.

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Mian, Muhammad Oneeb Rehman; Idris-Khodja, Noureddine; Li, Melissa W; Leibowitz, Avshalom; Paradis, Pierre; Rautureau, Yohann; Schiffrin, Ernesto L

2013-10-01

In human atherosclerosis, which is associated with elevated plasma and coronary endothelin (ET)-1 levels, ETA receptor antagonists improve coronary endothelial function. Mice overexpressing ET-1 specifically in the endothelium (eET-1) crossed with atherosclerosis-prone apolipoprotein E knockout mice (Apoe(-/-)) exhibit exaggerated high-fat diet (HFD)-induced atherosclerosis. Since endothelial dysfunction often precedes atherosclerosis development, we hypothesized that mice overexpressing endothelial ET-1 on a genetic background deficient in apolipoprotein E (eET-1/Apoe(-/-)) would have severe endothelial dysfunction. To test this hypothesis, we investigated endothelium-dependent relaxation (EDR) to acetylcholine in eET-1/Apoe(-/-) mice. EDR in mesenteric resistance arteries from 8- and 16-week-old mice fed a normal diet or HFD was improved in eET-1/Apoe(-/-) compared with Apoe(-/-) mice. Nitric oxide synthase (NOS) inhibition abolished EDR in Apoe(-/-). EDR in eET-1/Apoe(-/-) mice was resistant to NOS inhibition irrespective of age or diet. Inhibition of cyclooxygenase, the cytochrome P450 pathway, and endothelium-dependent hyperpolarization (EDH) resulted in little or no inhibition of EDR in eET-1/Apoe(-/-) compared with wild-type (WT) mice. In eET-1/Apoe(-/-) mice, blocking of EDH or soluble guanylate cyclase (sGC), in addition to NOS inhibition, decreased EDR by 36 and 30%, respectively. The activation of 4-aminopyridine-sensitive voltage-dependent potassium channels (Kv) during EDR was increased in eET-1/Apoe(-/-) compared with WT mice. We conclude that increasing eET-1 in mice that develop atherosclerosis results in decreased mutual dependence of endothelial signaling pathways responsible for EDR, and that NOS-independent activation of sGC and increased activation of Kv are responsible for enhanced EDR in this model of atherosclerosis associated with elevated endothelial and circulating ET-1.

Targeted Overexpression of Inducible 6-Phosphofructo-2-kinase in Adipose Tissue Increases Fat Deposition but Protects against Diet-induced Insulin Resistance and Inflammatory Responses*

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Huo, Yuqing; Guo, Xin; Li, Honggui; Xu, Hang; Halim, Vera; Zhang, Weiyu; Wang, Huan; Fan, Yang-Yi; Ong, Kuok Teong; Woo, Shih-Lung; Chapkin, Robert S.; Mashek, Douglas G.; Chen, Yanming; Dong, Hui; Lu, Fuer; Wei, Lai; Wu, Chaodong

2012-01-01

Increasing evidence demonstrates the dissociation of fat deposition, the inflammatory response, and insulin resistance in the development of obesity-related metabolic diseases. As a regulatory enzyme of glycolysis, inducible 6-phosphofructo-2-kinase (iPFK2, encoded by PFKFB3) protects against diet-induced adipose tissue inflammatory response and systemic insulin resistance independently of adiposity. Using aP2-PFKFB3 transgenic (Tg) mice, we explored the ability of targeted adipocyte PFKFB3/iPFK2 overexpression to modulate diet-induced inflammatory responses and insulin resistance arising from fat deposition in both adipose and liver tissues. Compared with wild-type littermates (controls) on a high fat diet (HFD), Tg mice exhibited increased adiposity, decreased adipose inflammatory response, and improved insulin sensitivity. In a parallel pattern, HFD-fed Tg mice showed increased hepatic steatosis, decreased liver inflammatory response, and improved liver insulin sensitivity compared with controls. In both adipose and liver tissues, increased fat deposition was associated with lipid profile alterations characterized by an increase in palmitoleate. Additionally, plasma lipid profiles also displayed an increase in palmitoleate in HFD-Tg mice compared with controls. In cultured 3T3-L1 adipocytes, overexpression of PFKFB3/iPFK2 recapitulated metabolic and inflammatory changes observed in adipose tissue of Tg mice. Upon treatment with conditioned medium from iPFK2-overexpressing adipocytes, mouse primary hepatocytes displayed metabolic and inflammatory responses that were similar to those observed in livers of Tg mice. Together, these data demonstrate a unique role for PFKFB3/iPFK2 in adipocytes with regard to diet-induced inflammatory responses in both adipose and liver tissues. PMID:22556414

Neuronal erythropoietin overexpression protects mice against age-related hearing loss (presbycusis).

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Monge Naldi, Arianne; Belfrage, Celina; Jain, Neha; Wei, Eric T; Canto Martorell, Belén; Gassmann, Max; Vogel, Johannes

2015-12-01

So far, typical causes of presbycusis such as degeneration of hair cells and/or primary auditory (spiral ganglion) neurons cannot be treated. Because erythropoietin's (Epo) neuroprotective potential has been shown previously, we determined hearing thresholds of juvenile and aged mice overexpressing Epo in neuronal tissues. Behavioral audiometry revealed in contrast to 5 months of age, that 11-month-old Epo-transgenic mice had up to 35 dB lower hearing thresholds between 1.4 and 32 kHz, and at the highest frequencies (50-80 kHz), thresholds could be obtained in aged Epo-transgenic only but not anymore in old C57BL6 control mice. Click-evoked auditory brainstem response showed similar results. Numbers of spiral ganglion neurons in aged C57BL6 but not Epo-transgenic mice were dramatically reduced mainly in the basal turn, the location of high frequencies. In addition, there was a tendency to better preservation of inner and outer hair cells in Epo-transgenic mice. Hence, Epo's known neuroprotective action effectively suppresses the loss of spiral ganglion cells and probably also hair cells and, thus, development of presbycusis in mice. Copyright © 2015 Elsevier Inc. All rights reserved.

ATP Synthase β-Chain Overexpression in SR-BI Knockout Mice Increases HDL Uptake and Reduces Plasma HDL Level

Directory of Open Access Journals (Sweden)

Kexiu Song

2014-01-01

Full Text Available HDL cholesterol is known to be inversely correlated with cardiovascular disease due to its diverse antiatherogenic functions. SR-BI mediates the selective uptake of HDL-C. SR-BI knockout diminishes but does not completely block the transport of HDL; other receptors may be involved. Ectopic ATP synthase β-chain in hepatocytes has been previously characterized as an apoA-I receptor, triggering HDL internalization. This study was undertaken to identify the overexpression of ectopic ATP synthase β-chain on DIL-HDL uptake in primary hepatocytes in vitro and on plasma HDL levels in SR-BI knockout mice. Human ATP synthase β-chain cDNA was delivered to the mouse liver by adenovirus and GFP adenovirus as control. The adenovirus-mediated overexpression of β-chain was identified at both mRNA and protein levels on mice liver and validated by its increasing of DiL-HDL uptake in primary hepatocytes. In response to hepatic overexpression of β-chain, plasma HDL-C levels and cholesterol were reduced in SR-BI knockout mice, compared with the control. The present data suggest that ATP synthase β-chain can serve as the endocytic receptor of HDL, and its overexpression can reduce plasma HDL-C.

Overexpression of survival motor neuron improves neuromuscular function and motor neuron survival in mutant SOD1 mice.

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Turner, Bradley J; Alfazema, Neza; Sheean, Rebecca K; Sleigh, James N; Davies, Kay E; Horne, Malcolm K; Talbot, Kevin

2014-04-01

Spinal muscular atrophy results from diminished levels of survival motor neuron (SMN) protein in spinal motor neurons. Low levels of SMN also occur in models of amyotrophic lateral sclerosis (ALS) caused by mutant superoxide dismutase 1 (SOD1) and genetic reduction of SMN levels exacerbates the phenotype of transgenic SOD1(G93A) mice. Here, we demonstrate that SMN protein is significantly reduced in the spinal cords of patients with sporadic ALS. To test the potential of SMN as a modifier of ALS, we overexpressed SMN in 2 different strains of SOD1(G93A) mice. Neuronal overexpression of SMN significantly preserved locomotor function, rescued motor neurons, and attenuated astrogliosis in spinal cords of SOD1(G93A) mice. Despite this, survival was not prolonged, most likely resulting from SMN mislocalization and depletion of gems in motor neurons of symptomatic mice. Our results reveal that SMN upregulation slows locomotor deficit onset and motor neuron loss in this mouse model of ALS. However, disruption of SMN nuclear complexes by high levels of mutant SOD1, even in the presence of SMN overexpression, might limit its survival promoting effects in this specific mouse model. Studies in emerging mouse models of ALS are therefore warranted to further explore the potential of SMN as a modifier of ALS. Copyright © 2014 Elsevier Inc. All rights reserved.

Salivary Gland Derived BDNF Overexpression in Mice Exerts an Anxiolytic Effect

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Saruta, Juri; To, Masahiro; Sugimoto, Masahiro; Yamamoto, Yuko; Shimizu, Tomoko; Nakagawa, Yusuke; Inoue, Hiroko; Saito, Ichiro; Tsukinoki, Keiichi

2017-01-01

Brain-derived neurotrophic factor (BDNF) is abundant in the hippocampus and plays critical roles in memory and synapse formation, as well as exerting antidepressant-like effects in psychiatric disorders. We previously reported that BDNF is expressed in salivary glands and affects blood BDNF content. However, the function of salivary BDNF remains unclear. The aim of this study was to generate transgenic mice overexpressing BDNF in the salivary glands. Hence, we used the Lama construct (hemaggl...

Overexpression of hepatocyte growth factor in SBMA model mice has an additive effect on combination therapy with castration

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Ding, Ying; Adachi, Hiroaki; Katsuno, Masahisa; Huang, Zhe; Jiang, Yue-Mei; Kondo, Naohide; Iida, Madoka; Tohnai, Genki; Nakatsuji, Hideaki; Funakoshi, Hiroshi; Nakamura, Toshikazu; Sobue, Gen

2015-01-01

Spinal and bulbar muscular atrophy (SBMA) is an inherited motor neuron disease caused by the expansion of a polyglutamine (polyQ)-encoding tract within the androgen receptor (AR) gene. The pathologic features of SBMA are motor neuron loss in the spinal cord and brainstem and diffuse nuclear accumulation and nuclear inclusions of mutant AR in residual motor neurons and certain visceral organs. Hepatocyte growth factor (HGF) is a polypeptide growth factor which has neuroprotective properties. To investigate whether HGF overexpression can affect disease progression in a mouse model of SBMA, we crossed SBMA transgenic model mice expressing an AR gene with an expanded CAG repeat with mice overexpressing HGF. Here, we report that high expression of HGF induces Akt phosphorylation and modestly ameliorated motor symptoms in an SBMA transgenic mouse model treated with or without castration. These findings suggest that HGF overexpression can provide a potential therapeutic avenue as a combination therapy with disease-modifying therapies in SBMA. - Highlights: • HGF overexpression ameliorates the motor phenotypes of the SBMA mouse model. • HGF overexpression induces Akt phosphorylation in the SBMA mouse model. • This is the first report of combination therapy in a mouse model of polyQ diseases.

Overexpression of hepatocyte growth factor in SBMA model mice has an additive effect on combination therapy with castration

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Ding, Ying [Department of Neurology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan); Adachi, Hiroaki, E-mail: hadachi-ns@umin.org [Department of Neurology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan); Department of Neurology, University of Occupational and Environmental Health School of Medicine, 1-1 Iseigaoka, Yahata-nishi-ku, Kitakyushu 807-8555 (Japan); Katsuno, Masahisa [Department of Neurology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan); Huang, Zhe [Department of Neurology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan); Department of Neurology, University of Occupational and Environmental Health School of Medicine, 1-1 Iseigaoka, Yahata-nishi-ku, Kitakyushu 807-8555 (Japan); Jiang, Yue-Mei; Kondo, Naohide; Iida, Madoka; Tohnai, Genki; Nakatsuji, Hideaki [Department of Neurology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan); Funakoshi, Hiroshi [Center for Advanced Research and Education, Asahikawa Medical University, 1-1-1- Higashinijo Midorigaoka, Asahikawa 078-8510 (Japan); Nakamura, Toshikazu [Neurogen Inc., 1-1-52-201 Nakahozumi, Ibaraki 567-0034 (Japan); Sobue, Gen, E-mail: sobueg@med.nagoya-u.ac.jp [Department of Neurology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan); Research Division of Dementia and Neurodegenerative Disease, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan)

2015-12-25

Spinal and bulbar muscular atrophy (SBMA) is an inherited motor neuron disease caused by the expansion of a polyglutamine (polyQ)-encoding tract within the androgen receptor (AR) gene. The pathologic features of SBMA are motor neuron loss in the spinal cord and brainstem and diffuse nuclear accumulation and nuclear inclusions of mutant AR in residual motor neurons and certain visceral organs. Hepatocyte growth factor (HGF) is a polypeptide growth factor which has neuroprotective properties. To investigate whether HGF overexpression can affect disease progression in a mouse model of SBMA, we crossed SBMA transgenic model mice expressing an AR gene with an expanded CAG repeat with mice overexpressing HGF. Here, we report that high expression of HGF induces Akt phosphorylation and modestly ameliorated motor symptoms in an SBMA transgenic mouse model treated with or without castration. These findings suggest that HGF overexpression can provide a potential therapeutic avenue as a combination therapy with disease-modifying therapies in SBMA. - Highlights: • HGF overexpression ameliorates the motor phenotypes of the SBMA mouse model. • HGF overexpression induces Akt phosphorylation in the SBMA mouse model. • This is the first report of combination therapy in a mouse model of polyQ diseases.

Mild overexpression of Mecp2 in mice causes a higher susceptibility toward seizures.

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Bodda, Chiranjeevi; Tantra, Martesa; Mollajew, Rustam; Arunachalam, Jayamuruga P; Laccone, Franco A; Can, Karolina; Rosenberger, Albert; Mironov, Sergej L; Ehrenreich, Hannelore; Mannan, Ashraf U

2013-07-01

An intriguing finding about the gene encoding methyl-CpG binding protein 2 (MeCP2) is that the loss-of-function mutations cause Rett syndrome and duplication (gain-of-function) of MECP2 leads to another neurological disorder termed MECP2 duplication syndrome. To ensure proper neurodevelopment, a precise regulation of MeCP2 expression is critical, and any gain or loss of MeCP2 over a narrow threshold level may lead to postnatal neurological impairment. To evaluate MeCP2 dosage effects, we generated Mecp2(WT_EGFP) transgenic (TG) mouse in which MeCP2 (endogenous plus TG) is mildly overexpressed (approximately 1.5×). The TG MeCP2(WT_EGFP) fusion protein is functionally active, as cross breeding of these mice with Mecp2 knockout mice led to alleviation of major phenotypes in the null mutant mice, including premature lethality. To characterize the Mecp2(WT_EGFP) mouse model, we performed an extensive battery of behavioral tests, which revealed that these mice manifest increased aggressiveness and higher pentylenetetrazole (PTZ)-induced seizure propensity. Evaluation of neuronal parameters revealed a reduction in the number of tertiary branching sites and increased spine density in Mecp2(WT_EGFP) transgenic (TG) neurons. Treatment of TG neurons with epileptogenic compound-PTZ led to a marked increase in amplitude and frequency of calcium spikes. Based on our ex vivo and in vivo data, we conclude that epileptic seizures are manifested as the first symptom when MeCP2 is mildly overexpressed in mice. Copyright © 2013 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Dose response of bone-targeted enzyme replacement for murine hypophosphatasia.

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Yadav, Manisha C; Lemire, Isabelle; Leonard, Pierre; Boileau, Guy; Blond, Laurent; Beliveau, Martin; Cory, Esther; Sah, Robert L; Whyte, Michael P; Crine, Philippe; Millán, José Luis

2011-08-01

Hypophosphatasia (HPP) features rickets or osteomalacia from tissue-nonspecific alkaline phosphatase (TNSALP) deficiency due to deactivating mutations within the ALPL gene. Enzyme replacement therapy with a bone-targeted, recombinant TNSALP (sALP-FcD(10), renamed ENB-0040) prevents manifestations of HPP when initiated at birth in TNSALP knockout (Akp2(-/-)) mice. Here, we evaluated the dose-response relationship of ENB-0040 to various phenotypic traits of Akp2(-/-) mice receiving daily subcutaneous (SC) injections of ENB-0040 from birth at 0.5, 2.0, or 8.2mg/kg for 43days. Radiographs, μCT, and histomorphometric analyses documented better bone mineralization with increasing doses of ENB-0040. We found a clear, positive correlation between ENB-0040 dose and prevention of mineralization defects of the feet, rib cage, lower limbs, and jaw bones. According to a dose-response model, the ED(80) (the dose that prevents bone defects in 80% of mice) was 3.2, 2.8 and 2.9mg/kg/day for these sites, respectively. Long bones seemed to respond to lower daily doses of ENB-0040. There was also a positive relationship between ENB-0040 dose and survival. Median survival, body weight, and bone length all improved with increasing doses of ENB-0040. Urinary PP(i) concentrations remained elevated in all treatment groups, indicating that while this parameter is a good biochemical marker for diagnosing HPP in patients, it may not be a good follow up marker for evaluating response to treatment when administering bone-targeted TNSALP to mice. These dose-response relationships strongly support the pharmacological efficacy of ENB-0040 for HPP, and provide the experimental basis for the therapeutic range of ENB-0040 chosen for clinical trials. Copyright © 2011 Elsevier Inc. All rights reserved.

Identification of clinical target areas in the brainstem of prion‐infected mice

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Mirabile, Ilaria; Jat, Parmjit S.; Brandner, Sebastian

2015-01-01

Aims While prion infection ultimately involves the entire brain, it has long been thought that the abrupt clinical onset and rapid neurological decline in laboratory rodents relates to involvement of specific critical neuroanatomical target areas. The severity and type of clinical signs, together with the rapid progression, suggest the brainstem as a candidate location for such critical areas. In this study we aimed to correlate prion pathology with clinical phenotype in order to identify clinical target areas. Method We conducted a comprehensive survey of brainstem pathology in mice infected with two distinct prion strains, which produce different patterns of pathology, in mice overexpressing prion protein (with accelerated clinical onset) and in mice in which neuronal expression was reduced by gene targeting (which greatly delays clinical onset). Results We identified specific brainstem areas that are affected by prion pathology during the progression of the disease. In the early phase of disease the locus coeruleus, the nucleus of the solitary tract, and the pre‐Bötzinger complex were affected by prion protein deposition. This was followed by involvement of the motor and autonomic centres of the brainstem. Conclusions Neurodegeneration in the locus coeruleus, the nucleus of the solitary tract and the pre‐Bötzinger complex predominated and corresponded to the manifestation of the clinical phenotype. Because of their fundamental role in controlling autonomic function and the overlap with clinical signs in sporadic Creutzfeldt–Jakob disease, we suggest that these nuclei represent key clinical target areas in prion diseases. PMID:25311251

Overexpression of catalase in mice reduces age-related oxidative stress and maintains sperm production.

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Selvaratnam, Johanna; Robaire, Bernard

2016-11-01

Advanced paternal age is associated with increased complications in pregnancy and genetic diseases in offspring. Oxidative stress is a major contributor to the damage accumulated in sperm during aging. Complex networks of antioxidants regulate reactive oxygen species (ROS) in the testis. While mounting evident shows that redox dysfunction compromises the quality of developing male germ cells, the mechanisms by which aging causes this remain unclear. Furthermore, therapies to successfully alleviate aging-associated loss in germ cell quality are limited. The antioxidant catalase (CAT) has been used in aging-associated pathologies to alleviate oxidative stress. We used mice overexpressing CAT (MCAT) to determine whether CAT overexpression alleviates the redox dysfunction observed with aging. We found that MCAT mice did not exhibit the age-dependent loss of spermatozoa, nor did they show aging associated loss in testicular germ and Sertoli cells seen in wild type (WT). Low overall ROS and reduced peroxynitrite levels were detected in spermatocytes from aged MCAT mice, following exposure to the pro-oxidant tert-butyl hydroperoxide. Germ cells from young MCATs showed elevated levels of DNA-damage repair markers, γ-H2AX and 53BP1, but this response was lost with aging. Finally, we found oxidative stress induced 8-oxodG lesions to increase in sperm with aging; these lesions were significantly reduced in aged MCAT and these mice showed no decrease in the age-dependent number of pups per litter. Thus we conclude that aged MCAT mice generate sperm at the same rate as young mice; these sperm are protected from oxidative stress associated damage. Copyright © 2016 Elsevier Inc. All rights reserved.

A53T-alpha-synuclein overexpression impairs dopamine signaling and striatal synaptic plasticity in old mice.

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Alexander Kurz

2010-07-01

Full Text Available Parkinson's disease (PD, the second most frequent neurodegenerative disorder at old age, can be caused by elevated expression or the A53T missense mutation of the presynaptic protein alpha-synuclein (SNCA. PD is characterized pathologically by the preferential vulnerability of the dopaminergic nigrostriatal projection neurons.Here, we used two mouse lines overexpressing human A53T-SNCA and studied striatal dysfunction in the absence of neurodegeneration to understand early disease mechanisms. To characterize the progression, we employed young adult as well as old mice. Analysis of striatal neurotransmitter content demonstrated that dopamine (DA levels correlated directly with the level of expression of SNCA, an observation also made in SNCA-deficient (knockout, KO mice. However, the elevated DA levels in the striatum of old A53T-SNCA overexpressing mice may not be transmitted appropriately, in view of three observations. First, a transcriptional downregulation of the extraneural DA degradation enzyme catechol-ortho-methytransferase (COMT was found. Second, an upregulation of DA receptors was detected by immunoblots and autoradiography. Third, extensive transcriptome studies via microarrays and quantitative real-time RT-PCR (qPCR of altered transcript levels of the DA-inducible genes Atf2, Cb1, Freq, Homer1 and Pde7b indicated a progressive and genotype-dependent reduction in the postsynaptic DA response. As a functional consequence, long term depression (LTD was absent in corticostriatal slices from old transgenic mice.Taken together, the dysfunctional neurotransmission and impaired synaptic plasticity seen in the A53T-SNCA overexpressing mice reflect early changes within the basal ganglia prior to frank neurodegeneration. As a model of preclinical stages of PD, such insights may help to develop neuroprotective therapeutic approaches.

Over-expression of X-linked inhibitor of apoptosis protein slows presbycusis in C57BL/6J mice.

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Wang, Jian; Menchenton, Trevor; Yin, Shankai; Yu, Zhiping; Bance, Manohar; Morris, David P; Moore, Craig S; Korneluk, Robert G; Robertson, George S

2010-07-01

Apoptosis of cochlear cells plays a significant role in age-related hearing loss or presbycusis. In this study, we evaluated whether over-expression of the anti-apoptotic protein known as X-linked Inhibitor of Apoptosis Protein (XIAP) slows the development of presbycusis. We compared the age-related hearing loss between transgenic (TG) mice that over-express human XIAP tagged with 6-Myc (Myc-XIAP) on a pure C57BL/6J genetic background with wild-type (WT) littermates by measuring auditory brainstem responses. The result showed that TG mice developed hearing loss considerably more slowly than WT littermates, primarily within the high-frequency range. The average total hair cell loss was significantly less in TG mice than WT littermates. Although levels of Myc-XIAP in the ear remained constant at 2 and 14 months, there was a marked increase in the amount of endogenous XIAP from 2 to 14 months in the cochlea, but not in the brain, in both genotypes. These results suggest that XIAP over-expression reduces age-related hearing loss and hair cell death in the cochlea. Copyright 2008 Elsevier Inc. All rights reserved.

EBI2 overexpression in mice leads to B1 B cell expansion and chronic lymphocytic leukemia-(CLL)-like B cell malignancies

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Niss Arfelt, Kristine; Barington, Line; Benned-Jensen, Tau

2017-01-01

-targeted expression of human EBI2 in mice reduces germinal center-dependent immune responses, reduces total IgM and IgG levels, and leads to increased proliferation and upregulation of cellular oncogenes. Furthermore, hEBI2 overexpression leads to an abnormally expanded CD5+ B1a B cell subset present as early as 4......Human and mouse chronic lymphocytic leukemia (CLL) develop from CD5+ B cells that in mice and macaques are known to define the distinct B1a B cell lineage. B1a cells are characterized by lack of germinal center development and the B1a cell population is increased in mice with reduced germinal...... cells towards the extrafollicular area, whereas downregulation is essential for germinal center formation. We therefore speculated whether increased expression of EBI2 would lead to an expanded B1 cell subset and, ultimately, progression to chronic lymphocytic leukemia. Here we demonstrate that B cell...

Overexpression of IGF-I in skeletal muscle of transgenic mice does not prevent unloading-induced atrophy

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Criswell, D. S.; Booth, F. W.; DeMayo, F.; Schwartz, R. J.; Gordon, S. E.; Fiorotto, M. L.

1998-01-01

This study examined the association between local insulin-like growth factor I (IGF-I) overexpression and atrophy in skeletal muscle. We hypothesized that endogenous skeletal muscle IGF-I mRNA expression would decrease with hindlimb unloading (HU) in mice, and that transgenic mice overexpressing human IGF-I (hIGF-I) specifically in skeletal muscle would exhibit less atrophy after HU. Male transgenic mice and nontransgenic mice from the parent strain (FVB) were divided into four groups (n = 10/group): 1) transgenic, weight-bearing (IGF-I/WB); 2) transgenic, hindlimb unloaded (IGF-I/HU); 3) nontransgenic, weight-bearing (FVB/WB); and 4) nontransgenic, hindlimb unloaded (FVB/HU). HU groups were hindlimb unloaded for 14 days. Body mass was reduced (P < 0.05) after HU in both IGF-I (-9%) and FVB mice (-13%). Contrary to our hypothesis, we found that the relative abundance of mRNA for the endogenous rodent IGF-I (rIGF-I) was unaltered by HU in the gastrocnemius (GAST) muscle of wild-type FVB mice. High-level expression of hIGF-I peptide and mRNA was confirmed in the GAST and tibialis anterior (TA) muscles of the transgenic mice. Nevertheless, masses of the GAST and TA muscles were reduced (P < 0.05) in both FVB/HU and IGF-I/HU groups compared with FVB/WB and IGF-I/WB groups, respectively, and the percent atrophy in mass of these muscles did not differ between FVB and IGF-I mice. Therefore, skeletal muscle atrophy may not be associated with a reduction of endogenous rIGF-I mRNA level in 14-day HU mice. We conclude that high local expression of hIGF-I mRNA and peptide in skeletal muscle alone cannot attenuate unloading-induced atrophy of fast-twitch muscle in mice.

Netrin-1 overexpression promotes white matter repairing and remodeling after focal cerebral ischemia in mice

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He, Xiaosong; Li, Yaning; Lu, Haiyan; Zhang, Zhijun; Wang, Yongting; Yang, Guo-Yuan

2013-01-01

Damage of oligodendrocytes after ischemia has negative impact on white matter integrity and neuronal function. In this work, we explore whether Netrin-1 (NT-1) overexpression facilitates white matter repairing and remodeling. Adult CD-1 mice received stereotactic injection of adeno-associated virus carrying NT-1 gene (AAV-NT-1). One week after gene transfer, mice underwent 60 minutes of middle cerebral artery occlusion. The effect of NT-1 on neural function was evaluated by neurobehavioral te...

Disturbed α-Cell Function in Mice with β-Cell Specific Overexpression of Human Islet Amyloid Polypeptide

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Bo Ahrén

2008-01-01

Full Text Available Exogenous administration of islet amyloid polypeptide (IAPP has been shown to inhibit both insulin and glucagon secretion. This study examined α-cell function in mice with β-cell specific overexpression of human IAPP (hIAPP after an oral protein gavage (75 mg whey protein/mouse. Baseline glucagon levels were higher in transgenic mice (41±4.0 pg/mL, n=6 than in wildtype animals (19±5.1 pg/mL, n=5, P=.015. In contrast, the glucagon response to protein was impaired in transgenic animals (21±2.7 pg/mL in transgenic mice versus 38±5.7 pg/mL in wildtype mice at 15 minutes; P=.027. Baseline insulin levels did not differ between the groups, while the insulin response, as the glucagon response, was impaired after protein challenge (P=.018. Glucose levels were not different between the groups and did not change significantly after protein gavage. Acetaminophen was given through gavage to the animals (2 mg/mouse to estimate gastric emptying. The plasma acetaminophen profile was similar in the two groups of mice. We conclude that disturbances in glucagon secretion exist in mice with β-cell specific overexpression of human IAPP, which are not secondary to changes in gastric emptying. The reduced glucagon response to protein challenge may reflect a direct inhibitory influence of hIAPP on glucagon secretion.

Widespread over-expression of the X chromosome in sterile F₁hybrid mice.

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Jeffrey M Good

2010-09-01

Full Text Available The X chromosome often plays a central role in hybrid male sterility between species, but it is unclear if this reflects underlying regulatory incompatibilities. Here we combine phenotypic data with genome-wide expression data to directly associate aberrant expression patterns with hybrid male sterility between two species of mice. We used a reciprocal cross in which F₁ males are sterile in one direction and fertile in the other direction, allowing us to associate expression differences with sterility rather than with other hybrid phenotypes. We found evidence of extensive over-expression of the X chromosome during spermatogenesis in sterile but not in fertile F₁ hybrid males. Over-expression was most pronounced in genes that are normally expressed after meiosis, consistent with an X chromosome-wide disruption of expression during the later stages of spermatogenesis. This pattern was not a simple consequence of faster evolutionary divergence on the X chromosome, because X-linked expression was highly conserved between the two species. Thus, transcriptional regulation of the X chromosome during spermatogenesis appears particularly sensitive to evolutionary divergence between species. Overall, these data provide evidence for an underlying regulatory basis to reproductive isolation in house mice and underscore the importance of transcriptional regulation of the X chromosome to the evolution of hybrid male sterility.

Widespread over-expression of the X chromosome in sterile F₁hybrid mice.

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Good, Jeffrey M; Giger, Thomas; Dean, Matthew D; Nachman, Michael W

2010-09-30

The X chromosome often plays a central role in hybrid male sterility between species, but it is unclear if this reflects underlying regulatory incompatibilities. Here we combine phenotypic data with genome-wide expression data to directly associate aberrant expression patterns with hybrid male sterility between two species of mice. We used a reciprocal cross in which F₁ males are sterile in one direction and fertile in the other direction, allowing us to associate expression differences with sterility rather than with other hybrid phenotypes. We found evidence of extensive over-expression of the X chromosome during spermatogenesis in sterile but not in fertile F₁ hybrid males. Over-expression was most pronounced in genes that are normally expressed after meiosis, consistent with an X chromosome-wide disruption of expression during the later stages of spermatogenesis. This pattern was not a simple consequence of faster evolutionary divergence on the X chromosome, because X-linked expression was highly conserved between the two species. Thus, transcriptional regulation of the X chromosome during spermatogenesis appears particularly sensitive to evolutionary divergence between species. Overall, these data provide evidence for an underlying regulatory basis to reproductive isolation in house mice and underscore the importance of transcriptional regulation of the X chromosome to the evolution of hybrid male sterility.

100-fold but not 50-fold dystrophin overexpression aggravates electrocardiographic defects in the mdx model of Duchenne muscular dystrophy

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Yongping Yue

2016-01-01

Full Text Available Dystrophin gene replacement holds the promise of treating Duchenne muscular dystrophy. Supraphysiological expression is a concern for all gene therapy studies. In the case of Duchenne muscular dystrophy, Chamberlain and colleagues found that 50-fold overexpression did not cause deleterious side effect in skeletal muscle. To determine whether excessive dystrophin expression in the heart is safe, we studied two lines of transgenic mdx mice that selectively expressed a therapeutic minidystrophin gene in the heart at 50-fold and 100-fold of the normal levels. In the line with 50-fold overexpression, minidystrophin showed sarcolemmal localization and electrocardiogram abnormalities were corrected. However, in the line with 100-fold overexpression, we not only detected sarcolemmal minidystrophin expression but also observed accumulation of minidystrophin vesicles in the sarcoplasm. Excessive minidystrophin expression did not correct tachycardia, a characteristic feature of Duchenne muscular dystrophy. Importantly, several electrocardiogram parameters (QT interval, QRS duration and the cardiomyopathy index became worse than that of mdx mice. Our data suggests that the mouse heart can tolerate 50-fold minidystrophin overexpression, but 100-fold overexpression leads to cardiac toxicity.

Dek overexpression in murine epithelia increases overt esophageal squamous cell carcinoma incidence

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Cimperman, Katherine A.; Haas, Sarah R.; Guasch, Geraldine; Waclaw, Ronald R.; Komurov, Kakajan; Lane, Adam; Wikenheiser-Brokamp, Kathryn A.

2018-01-01

Esophageal cancer occurs as either squamous cell carcinoma (ESCC) or adenocarcinoma. ESCCs comprise almost 90% of cases worldwide, and recur with a less than 15% five-year survival rate despite available treatments. The identification of new ESCC drivers and therapeutic targets is critical for improving outcomes. Here we report that expression of the human DEK oncogene is strongly upregulated in esophageal SCC based on data in the cancer genome atlas (TCGA). DEK is a chromatin-associated protein with important roles in several nuclear processes including gene transcription, epigenetics, and DNA repair. Our previous data have utilized a murine knockout model to demonstrate that Dek expression is required for oral and esophageal SCC growth. Also, DEK overexpression in human keratinocytes, the cell of origin for SCC, was sufficient to cause hyperplasia in 3D organotypic raft cultures that mimic human skin, thus linking high DEK expression in keratinocytes to oncogenic phenotypes. However, the role of DEK over-expression in ESCC development remains unknown in human cells or genetic mouse models. To define the consequences of Dek overexpression in vivo, we generated and validated a tetracycline responsive Dek transgenic mouse model referred to as Bi-L-Dek. Dek overexpression was induced in the basal keratinocytes of stratified squamous epithelium by crossing Bi-L-Dek mice to keratin 5 tetracycline transactivator (K5-tTA) mice. Conditional transgene expression was validated in the resulting Bi-L-Dek_K5-tTA mice and was suppressed with doxycycline treatment in the tetracycline-off system. The mice were subjected to an established HNSCC and esophageal carcinogenesis protocol using the chemical carcinogen 4-nitroquinoline 1-oxide (4NQO). Dek overexpression stimulated gross esophageal tumor development, when compared to doxycycline treated control mice. Furthermore, high Dek expression caused a trend toward esophageal hyperplasia in 4NQO treated mice. Taken together, these

Amyloid β Is Not the Major Factor Accounting for Impaired Adult Hippocampal Neurogenesis in Mice Overexpressing Amyloid Precursor Protein

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Hongyu Pan

2016-10-01

Full Text Available Adult hippocampal neurogenesis was impaired in several Alzheimer's disease models overexpressing mutant human amyloid precursor protein (hAPP. However, the effects of wild-type hAPP on adult neurogenesis and whether the impaired adult hippocampal neurogenesis was caused by amyloid β (Aβ or APP remained unclear. Here, we found that neurogenesis was impaired in the dentate gyrus (DG of adult mice overexpressing wild-type hAPP (hAPP-I5 compared with controls. However, the adult hippocampal neurogenesis was more severely impaired in hAPP-I5 than that in hAPP-J20 mice, which express similar levels of hAPP mRNA but much higher levels of Aβ. Furthermore, reducing Aβ levels did not affect the number of doublecortin-positive cells in the DG of hAPP-J20 mice. Our results suggested that hAPP was more likely an important factor inhibiting adult neurogenesis, and Aβ was not the major factor affecting neurogenesis in the adult hippocampus of hAPP mice.

Effects of striatal ΔFosB overexpression and ketamine on social defeat stress-induced anhedonia in mice.

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Donahue, Rachel J; Muschamp, John W; Russo, Scott J; Nestler, Eric J; Carlezon, William A

2014-10-01

Chronic social defeat stress (CSDS) produces persistent behavioral adaptations in mice. In many behavioral assays, it can be difficult to determine if these adaptations reflect core signs of depression. We designed studies to characterize the effects of CSDS on sensitivity to reward because anhedonia (reduced sensitivity to reward) is a defining characteristic of depressive disorders in humans. We also examined the effects of striatal ΔFosB overexpression and the N-methyl-D-aspartate receptor antagonist ketamine, both of which promote resilience, on CSDS-induced alterations in reward function and social interaction. Intracranial self-stimulation (ICSS) was used to quantify CSDS-induced changes in reward function. Mice were implanted with lateral hypothalamic electrodes, and ICSS thresholds were measured after each of 10 daily CSDS sessions and during a 5-day recovery period. We also examined if acute intraperitoneal administration of ketamine (2.5-20 mg/kg) reverses CSDS-induced effects on reward or, in separate mice, social interaction. ICSS thresholds were increased by CSDS, indicating decreases in the rewarding impact of lateral hypothalamic stimulation (anhedonia). This effect was attenuated in mice overexpressing ∆FosB in striatum, consistent with pro-resilient actions of this transcription factor. High, but not low, doses of ketamine administered after completion of the CSDS regimen attenuated social avoidance in defeated mice, although this effect was transient. Ketamine did not block CSDS-induced anhedonia in the ICSS test. This study found that CSDS triggers persistent anhedonia and confirms that ΔFosB overexpression produces stress resilience. The findings of this study also indicate that acute administration of ketamine fails to attenuate CSDS-induced anhedonia despite reducing other depression-related behavioral abnormalities. Copyright © 2014 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Targeted overexpression of EZH2 in the mammary gland disrupts ductal morphogenesis and causes epithelial hyperplasia.

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Li, Xin; Gonzalez, Maria E; Toy, Katherine; Filzen, Tracey; Merajver, Sofia D; Kleer, Celina G

2009-09-01

The Polycomb group protein enhancer of zeste homolog 2 (EZH2), which has roles during development of numerous tissues, is a critical regulator of cell type identity. Overexpression of EZH2 has been detected in invasive breast carcinoma tissue samples and is observed in human breast tissue samples of morphologically normal lobules up to 12 years before the development of breast cancer. The function of EZH2 during preneoplastic progression in the mammary gland is unknown. To investigate the role of EZH2 in the mammary gland, we targeted the expression of EZH2 to mammary epithelial cells using the mouse mammary tumor virus long terminal repeat. EZH2 overexpression resulted in aberrant terminal end bud architecture. By the age of 4 months, 100% of female mouse mammary tumor virus-EZH2 virgin mice developed intraductal epithelial hyperplasia resembling the human counterpart accompanied by premature differentiation of ductal epithelial cells and up-regulation of the luminal marker GATA-3. In addition, remodeling of the mammary gland after parturition was impaired and EZH2 overexpression caused delayed involution. Mechanistically, we found that EZH2 physically interacts with beta-catenin, inducing beta-catenin nuclear accumulation in mammary epithelial cells and activating Wnt/beta-catenin signaling. The biological significance of these data to human hyperplasias is demonstrated by EZH2 up-regulation and colocalization with beta-catenin in human intraductal epithelial hyperplasia, the earliest histologically identifiable precursor of breast carcinoma.

Transgenic mice display hair loss and regrowth overexpressing mutant Hr gene.

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Zhu, Kuicheng; Xu, Cunshuan; Zhang, Jintao; Chen, Yingying; Liu, Mengduan

2017-10-30

Mutations in the hairless (Hr) gene in both mice and humans have been implicated in the development of congenital atrichia, but the role of Hr in skin and hair follicle (HF) biology remains unknown. Here, we established transgenic mice (TG) overexpressing mutant Hr to investigate its specific role in the development of HF. Three transgenic lines were successfully constructed, and two of them (TG3 and TG8) displayed a pattern of hair loss and regrowth with alternation in the expression of HR protein. The mutant Hr gene inhibited the expression of the endogenous gene in transgenic individuals, which led to the development of alopecia. Interestingly, the hair regrew with the increase in the endogenous expression levels resulting from decreased mutant Hr expression. The findings of our study indicate that the changes in the expression of Hr result in hair loss or regrowth.

Overexpression of a transcription factor LYL1 induces T- and B-cell lymphoma in mice.

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Zhong, Y; Jiang, L; Hiai, H; Toyokuni, S; Yamada, Y

2007-10-18

LYL1, a member of the class II basic helix-loop-helix transcription factors, is aberrantly expressed in a fraction of human T-cell acute lymphoblastic leukemia. Here, we generated transgenic mice ubiquitously overexpressing LYL1 using a construct expressing full-length cDNA driven by a human elongation factor 1alpha promoter. Four independent lines exhibiting high LYL1 expression were established. Of these transgenic mice, 96% displayed loss of hair with a short kinked tail. Furthermore, 30% of them developed malignant lymphoma, with an average latent period of 352 days. In these mice, histological examination revealed tumor cell infiltration in multiple organs and immunohistochemical analysis showed that the infiltrated tumor cells were either CD3 or CD45R/B220-positive; fluorescence-activated cell sorter analysis indicated that each tumor consisted either of mainly CD4, CD8 double-positive T cells or mature B cells; the clonality of LYL1-induced lymphoma was confirmed by T-cell receptor rearrangement and immunoglobulin heavy-chain gene rearrangement analyses. Mammalian two-hybrid analysis and luciferase assay suggested that excess LYL1 blocked the dimerization of E2A and thus inhibited the regulatory activity of E2A on the CD4 promoter. Reverse transcription-polymerase chain reaction results showed that the expression of certain E2A/HEB target genes was downregulated. Taken together, our results provide direct evidence that aberrant expression of LYL1 plays a role in lymphomagenesis.

Morphogenetic roles of perlecan in the tooth enamel organ: an analysis of overexpression using transgenic mice.

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Ida-Yonemochi, Hiroko; Satokata, Ichiro; Ohshima, Hayato; Sato, Toshiya; Yokoyama, Minesuke; Yamada, Yoshihiko; Saku, Takashi

2011-09-01

Perlecan, a heparan sulfate proteoglycan, is enriched in the intercellular space of the enamel organ. To understand the role of perlecan in tooth morphogenesis, we used a keratin 5 promoter to generate transgenic (Tg) mice that over-express perlecan in epithelial cells, and examined their tooth germs at tissue and cellular levels. Immunohistochemistry showed that perlecan was more strongly expressed in the enamel organ cells of Tg mice than in wild-type mice. Histopathology showed wider intercellular spaces in the stellate reticulum of the Tg molars and loss of cellular polarity in the enamel organ, especially in its cervical region. Hertwig's epithelial root sheath (HERS) cells in Tg mice were irregularly aligned due to excessive deposits of perlecan along the inner, as well as on the outer sides of the HERS. Tg molars had dull-ended crowns and outward-curved tooth roots and their enamel was poorly crystallized, resulting in pronounced attrition of molar cusp areas. In Tg mice, expression of integrin β1 mRNA was remarkably higher at E18, while expression of bFGF, TGF-β1, DSPP and Shh was more elevated at P1. The overexpression of perlecan in the enamel organ resulted in irregular morphology of teeth, suggesting that the expression of perlecan regulates growth factor signaling in a stage-dependent manner during each step of the interaction between ameloblast-lineage cells and mesenchymal cells. Copyright © 2011 International Society of Matrix Biology. All rights reserved.

Increased Melanoma Growth and Metastasis Spreading in Mice Overexpressing Placenta Growth Factor

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Marcellini, Marcella; De Luca, Naomi; Riccioni, Teresa; Ciucci, Alessandro; Orecchia, Angela; Lacal, Pedro Miguel; Ruffini, Federica; Pesce, Maurizio; Cianfarani, Francesca; Zambruno, Giovanna; Orlandi, Augusto; Failla, Cristina Maria

2006-01-01

Placenta growth factor (PlGF), a member of the vascular endothelial growth factor family, plays an important role in adult pathological angiogenesis. To further investigate PlGF functions in tumor growth and metastasis formation, we used transgenic mice overexpressing PlGF in the skin under the control of the keratin 14 promoter. These animals showed a hypervascularized phenotype of the skin and increased levels of circulating PlGF with respect to their wild-type littermates. Transgenic mice and controls were inoculated intradermally with B16-BL6 melanoma cells. The tumor growth rate was fivefold increased in transgenic animals compared to wild-type mice, in the presence of a similar percentage of tumor necrotic tissue. Tumor vessel area was increased in transgenic mice as compared to controls. Augmented mobilization of endothelial and hematopoietic stem cells from the bone marrow was observed in transgenic animals, possibly contributing to tumor vascularization. The number and size of pulmonary metastases were significantly higher in transgenic mice compared to wild-type littermates. Finally, PlGF promoted tumor cell invasion of the extracellular matrix and increased the activity of selected matrix metalloproteinases. These findings indicate that PlGF, in addition to enhancing tumor angiogenesis and favoring tumor growth, may directly influence melanoma dissemination. PMID:16877362

Widespread Over-Expression of the X Chromosome in Sterile F1 Hybrid Mice

Science.gov (United States)

Good, Jeffrey M.; Giger, Thomas; Dean, Matthew D.; Nachman, Michael W.

2010-01-01

The X chromosome often plays a central role in hybrid male sterility between species, but it is unclear if this reflects underlying regulatory incompatibilities. Here we combine phenotypic data with genome-wide expression data to directly associate aberrant expression patterns with hybrid male sterility between two species of mice. We used a reciprocal cross in which F1 males are sterile in one direction and fertile in the other direction, allowing us to associate expression differences with sterility rather than with other hybrid phenotypes. We found evidence of extensive over-expression of the X chromosome during spermatogenesis in sterile but not in fertile F1 hybrid males. Over-expression was most pronounced in genes that are normally expressed after meiosis, consistent with an X chromosome-wide disruption of expression during the later stages of spermatogenesis. This pattern was not a simple consequence of faster evolutionary divergence on the X chromosome, because X-linked expression was highly conserved between the two species. Thus, transcriptional regulation of the X chromosome during spermatogenesis appears particularly sensitive to evolutionary divergence between species. Overall, these data provide evidence for an underlying regulatory basis to reproductive isolation in house mice and underscore the importance of transcriptional regulation of the X chromosome to the evolution of hybrid male sterility. PMID:20941395

MsrA Overexpression Targeted to the Mitochondria, but Not Cytosol, Preserves Insulin Sensitivity in Diet-Induced Obese Mice.

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JennaLynn Hunnicut

Full Text Available There is growing evidence that oxidative stress plays an integral role in the processes by which obesity causes type 2 diabetes. We previously identified that mice lacking the protein oxidation repair enzyme methionine sulfoxide reductase A (MsrA are particularly prone to obesity-induced insulin resistance suggesting an unrecognized role for this protein in metabolic regulation. The goals of this study were to test whether increasing the expression of MsrA in mice can protect against obesity-induced metabolic dysfunction and to elucidate the potential underlying mechanisms. Mice with increased levels of MsrA in the mitochondria (TgMito MsrA or in the cytosol (TgCyto MsrA were fed a high fat/high sugar diet and parameters of glucose homeostasis were monitored. Mitochondrial content, markers of mitochondrial proteostasis and mitochondrial energy utilization were assessed. TgMito MsrA, but not TgCyto MsrA, mice remain insulin sensitive after high fat feeding, though these mice are not protected from obesity. This metabolically healthy obese phenotype of TgMito MsrA mice is not associated with changes in mitochondrial number or biogenesis or with a reduction of proteostatic stress in the mitochondria. However, our data suggest that increased mitochondrial MsrA can alter metabolic homeostasis under diet-induced obesity by activating AMPK signaling, thereby defining a potential mechanism by which this genetic alteration can prevent insulin resistance without affecting obesity. Our data suggest that identification of targets that maintain and regulate the integrity of the mitochondrial proteome, particular against oxidative damage, may play essential roles in the protection against metabolic disease.

Reversing hypomyelination in BACE1-null mice with Akt-DD overexpression.

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Hu, Xiangyou; Schlanger, Rita; He, Wanxia; Macklin, Wendy B; Yan, Riqiang

2013-05-01

β-Site amyloid precursor protein convertase enzyme 1 (BACE1), a type I transmembrane aspartyl protease required to cleave amyloid precursor protein for releasing a toxic amyloid peptide, also cleaves type I and type III neuregulin-1 (Nrg-1). BACE1 deficiency in mice causes hypomyelination during development and impairs remyelination if injured. In BACE1-null mice, the abolished cleavage of neuregulin-1 by BACE1 is speculated to cause reduced myelin sheath thickness in both the central nervous system and peripheral nervous system because reduced cleavage of Nrg-1 correlates with reduced Akt phosphorylation, a downstream signaling molecule of the Nrg-1/ErbB pathway. Here we tested specifically whether increasing Akt activity alone in oligodendrocytes would be sufficient to reverse the hypomyelination phenotype in BACE1-null mice. BACE1-null mice were bred with transgenic mice expressing constitutively active Akt (Akt-DD; mutations with D(308)T and D(473)S) in oligodendrocytes. Relative to littermate BACE1-null controls, BACE1(-/-)/Akt-DD mice exhibited enhanced expression of myelin basic protein and promoter of proteolipid protein. The elevated expression of myelin proteins correlated with a thicker myelin sheath in optic nerves; comparison of quantified g ratios with statistic significance was used to confirm this reversion. However, it appeared that myelin sheath thickness in the sciatic nerves was not increased in BACE1(-/-)/Akt-DD mice, as the g ratio was not significantly different from the control. Hence, increased Akt activity in BACE1-null myelinating cells only compensates for the loss of BACE1 activity in the central nervous system, which is consistent with the observation that overexpression of Akt-DD in Schwann cells did not induce hypermyelination. Our results suggest that signaling activity other than Akt may also contribute to proper myelination in peripheral nerves.

Identification of cytotoxic drugs that selectively target tumor cells with MYC overexpression.

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Anna Frenzel

Full Text Available Expression of MYC is deregulated in a wide range of human cancers, and is often associated with aggressive disease and poorly differentiated tumor cells. Identification of compounds with selectivity for cells overexpressing MYC would hence be beneficial for the treatment of these tumors. For this purpose we used cell lines with conditional MYCN or c-MYC expression, to screen a library of 80 conventional cytotoxic compounds for their ability to reduce tumor cell viability and/or growth in a MYC dependent way. We found that 25% of the studied compounds induced apoptosis and/or inhibited proliferation in a MYC-specific manner. The activities of the majority of these were enhanced both by c-MYC or MYCN over-expression. Interestingly, these compounds were acting on distinct cellular targets, including microtubules (paclitaxel, podophyllotoxin, vinblastine and topoisomerases (10-hydroxycamptothecin, camptothecin, daunorubicin, doxorubicin, etoposide as well as DNA, RNA and protein synthesis and turnover (anisomycin, aphidicholin, gliotoxin, MG132, methotrexate, mitomycin C. Our data indicate that MYC overexpression sensitizes cells to disruption of specific pathways and that in most cases c-MYC and MYCN overexpression have similar effects on the responses to cytotoxic compounds. Treatment of the cells with topoisomerase I inhibitors led to down-regulation of MYC protein levels, while doxorubicin and the small molecule MYRA-A was found to disrupt MYC-Max interaction. We conclude that the MYC pathway is only targeted by a subset of conventional cytotoxic drugs currently used in the clinic. Elucidating the mechanisms underlying their specificity towards MYC may be of importance for optimizing treatment of tumors with MYC deregulation. Our data also underscores that MYC is an attractive target for novel therapies and that cellular screenings of chemical libraries can be a powerful tool for identifying compounds with a desired biological activity.

Overexpression of copper/zinc-superoxide dismutase in transgenic mice markedly impairs regeneration and increases development of neuropathic pain after sciatic nerve injury.

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Kotulska, Katarzyna; LePecheur, Marie; Marcol, Wiesław; Lewin-Kowalik, Joanna; Larysz-Brysz, Magdalena; Paly, Evelyn; Matuszek, Iwona; London, Jacqueline

2006-10-01

Despite the general capacity of peripheral nervous system to regenerate, peripheral nerve injury is often followed by incomplete recovery of function, sometimes with the burden of neuropathic pain. The mechanisms of both regeneration and nociception have not been clarified, but it is known that inflammatory reactions are involved. Cu/Zn-superoxide dismutase (SOD1) is an important scavenger protein that acts against oxidative stress. It has been shown to play an important role in apoptosis and inflammation. The aim of this study was to examine the role of SOD1 overexpression in peripheral nerve regeneration and neuropathic pain-related behavior in mice. Sciatic nerves of SOD1-overexpressing and FVB/N wild type-mice were transected and immediately resutured. Evaluation of motor and sensory function and autotomy was carried out during 4 weeks of followup. We found markedly worse sciatic function index outcome as well as more significant atrophy of denervated muscles in SOD1-overexpressing animals compared with wild type. Autotomy was markedly worse in SOD1 transgenic mice than in wild-type animals. Histological evaluation revealed that the intensity of regeneration features, including numbers of GAP-43-positive growth cones, Schwann cells, and macrophages in the distal stump of the transected nerve, was also decreased in transgenic mice. Neuroma formation at the injury site was significantly more prominent in this group. Taken together, our findings suggest that SOD1 overexpression is deleterious for nerve regeneration processes and aggravates neuropathic pain-like state in mice. This can be at least partially ascribed to disturbed inflammatory reactions at the injury site. Copyright 2006 Wiley-Liss, Inc.

Nras Overexpression Results in Granulocytosis, T-Cell Expansion and Early Lethality in Mice

DEFF Research Database (Denmark)

Lassen, Louise Berkhoudt; Gonzalez, Borja Ballarin; Schmitz, Alexander

2012-01-01

NRAS is a proto-oncogene involved in numerous myeloid malignancies. Here, we report on a mouse line bearing a single retroviral long terminal repeat inserted into Nras. This genetic modification resulted in an increased level of wild type Nras mRNA giving the possibility of studying the function ...... the increment in immature myeloid cells detected in these mice. The short latency period indicates that Nras overexpression alone is sufficient to cause dose-dependent granulocytosis and T-cell expansion....

Increased heart rate variability in mice overexpressing the Cu/Zn superoxide dismutase.

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Thireau, Jérôme; Poisson, Denise; Zhang, Bei Li; Gillet, Ludovic; Le Pécheur, Marie; Andres, Christian; London, Jacqueline; Babuty, Dominique

2008-08-15

Cu/Zn superoxide dismutase (SOD1) is implicated in various pathological conditions including Down's syndrome, neurodegenerative diseases, and afflictions of the autonomic nervous system (ANS). To assess the SOD1 contribution to ANS dysfunction, especially its influence on cardiac regulation, we studied the heart rate variability (HRV) and cardiac arrhythmias in conscious 12-month-old male and female transgenic mice for the human SOD1 gene (TghSOD1). TghSOD1 mice presented heart rate reduction as compared with control FVB/N individuals. All HRV parameters reflecting parasympathetic activity were increased in TghSOD1. Pharmacological studies confirmed that the parasympathetic tone was exacerbated and the sympathetic pathway was functional in TghSOD1 mice. A high frequency of atrioventricular block and premature ventricular contractions was observed in TghSOD1. By biochemical assays we found that SOD1 activities were multiplied by 9 and 4 respectively in the heart and brainstem of transgenic mice. A twofold decrease in cholinesterase activity was observed in the heart but not in the brainstem. We demonstrate that SOD1 overexpression induces an ANS dysfunction by an exacerbated vagal tone that may be related to impaired cardiac activity of the cholinesterases and may explain the high occurrence of arrhythmias.

Over-expression of two different forms of the alpha-secretase ADAM10 affects learning and memory in mice.

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Schmitt, Ulrich; Hiemke, Christoph; Fahrenholz, Falk; Schroeder, Anja

2006-12-15

Members of the ADAM family (adisintegrin and metalloprotease) are the main candidates for physiologically relevant alpha-secretases. The alpha-secretase cleaves in the non-amyloidogenic pathway the amyloid precursor protein within the region of the Abeta peptides preventing their aggregation in the brain. The increase of alpha-secretase activity in the brain provides a plausible strategy to prevent Abeta formation. Concerning this possibility two transgenic mouse lines (FVB/N) have been created: mice over-expressing the bovine form of the alpha-secretase (ADAM10) and mice over-expressing an inactive form of the alpha-secretase (ADAM10-E348A-HA; ADAM10-dn). For behavioral examination a F1 generation of transgenic mice (C57Bl/6 x FVB/N (tg)) was generated and compared to wild type F1 generation (C57Bl/6 x FVB/N). Behavior was characterized in the following tasks: standard open field, enriched open field, elevated plus-maze, and the Morris water maze hidden platform task. Concerning basal activity, exploration, and anxiety, transgenic mice behaved similar to controls. With respect to learning and memory both transgenic lines showed a significant deficit compared to controls. ADAM10 mice however, showed thigmotaxis with passive floating behavior in the Morris water maze indicating differences in motivation, whereas, ADAM10-dn mice displayed an inconspicuous but limited goal-directed search pattern. Thus variation of the enzymatic activity of alpha-secretase ADAM10 alters learning and memory differentially. Nevertheless, it could be concluded that both, ADAM10 and ADAM10-dn mice are suitable control mice for the assessment of alpha-secretase-related effects in animal models of Alzheimer's disease.

Human HMGA2 protein overexpressed in mice induces precursor T-cell lymphoblastic leukemia

International Nuclear Information System (INIS)

Efanov, A; Zanesi, N; Coppola, V; Nuovo, G; Bolon, B; Wernicle-Jameson, D; Lagana, A; Hansjuerg, A; Pichiorri, F; Croce, C M

2014-01-01

T-cell acute lymphoblastic leukemia (T-ALL) is a neoplasia of thymocytes characterized by the rapid accumulation of the precursors of T lymphocytes. HMGA2 (high-mobility group AT-hook 2) gene expression is extremely low in normal adult tissues, but it is overexpressed in many tumors. To identify the biological function of HMGA2, we generated transgenic mice carrying the human HMGA2 gene under control of the V H promoter/Eμ enhancer. Approximately 90% of Eμ-HMGA2 transgenic mice became visibly sick between 4 and 8 months due to the onset and progression of a T-ALL-like disease. Characteristic features included severe alopecia (30% of mice); enlarged lymph nodes and spleen; and profound immunological abnormalities (altered cytokine levels, hypoimmunoglobulinemia) leading to reduced immune responsiveness. Immunophenotyping showed accumulation of CD5+CD4+, CD5+CD8+ or CD5+CD8+CD4+ T-cell populations in the spleens and bone marrow of sick animals. These findings show that HMGA2-driven leukemia in mice closely resembles spontaneous human T-ALL, indicating that HMGA2 transgenic mice should serve as an important model for investigating basic mechanisms and potential new therapies of relevance to human T-ALL

AAV-mediated pancreatic overexpression of Igf1 counteracts progression to autoimmune diabetes in mice.

Science.gov (United States)

Mallol, Cristina; Casana, Estefania; Jimenez, Veronica; Casellas, Alba; Haurigot, Virginia; Jambrina, Claudia; Sacristan, Victor; Morró, Meritxell; Agudo, Judith; Vilà, Laia; Bosch, Fatima

2017-07-01

Type 1 diabetes is characterized by autoimmune destruction of β-cells leading to severe insulin deficiency. Although many improvements have been made in recent years, exogenous insulin therapy is still imperfect; new therapeutic approaches, focusing on preserving/expanding β-cell mass and/or blocking the autoimmune process that destroys islets, should be developed. The main objective of this work was to test in non-obese diabetic (NOD) mice, which spontaneously develop autoimmune diabetes, the effects of local expression of Insulin-like growth factor 1 (IGF1), a potent mitogenic and pro-survival factor for β-cells with immunomodulatory properties. Transgenic NOD mice overexpressing IGF1 specifically in β-cells (NOD-IGF1) were generated and phenotyped. In addition, miRT-containing, IGF1-encoding adeno-associated viruses (AAV) of serotype 8 (AAV8-IGF1-dmiRT) were produced and administered to 4- or 11-week-old non-transgenic NOD females through intraductal delivery. Several histological, immunological, and metabolic parameters were measured to monitor disease over a period of 28-30 weeks. In transgenic mice, local IGF1 expression led to long-term suppression of diabetes onset and robust protection of β-cell mass from the autoimmune insult. AAV-mediated pancreatic-specific overexpression of IGF1 in adult animals also dramatically reduced diabetes incidence, both when vectors were delivered before pathology onset or once insulitis was established. Transgenic NOD-IGF1 and AAV8-IGF1-dmiRT-treated NOD animals had much less islet infiltration than controls, preserved β-cell mass, and normal insulinemia. Transgenic and AAV-treated islets showed less expression of antigen-presenting molecules, inflammatory cytokines, and chemokines important for tissue-specific homing of effector T cells, suggesting IGF1 modulated islet autoimmunity in NOD mice. Local expression of Igf1 by AAV-mediated gene transfer counteracts progression to diabetes in NOD mice. This study suggests a

Enhanced Androgen Signaling With Androgen Receptor Overexpression in the Osteoblast Lineage Controls Skeletal Turnover, Matrix Quality and Bone Architecture

National Research Council Canada - National Science Library

Wiren, Kristine M; Jepsen, Karl

2006-01-01

.... We genetically engineered transgenic mice in which androgen receptor (AR) overexpression is skeletally targeted in two separate models to better understand the role of androgen signaling directly in bone...

An array of Escherichia coli clones over-expressing essential proteins: A new strategy of identifying cellular targets of potent antibacterial compounds

International Nuclear Information System (INIS)

Xu, H. Howard; Real, Lilian; Bailey, Melissa Wu

2006-01-01

With the advancement of high throughput screening, it has become easier and faster to discover hit compounds that inhibit proliferation of bacterial cells. However, development in technologies used to identify cellular targets of potent antibacterial inhibitors has lagged behind. Here, we describe a novel strategy of target identification for antibacterial inhibitors using an array of Escherichia coli clones each over-expressing one essential protein. In a proof-of-concept study, eight essential genes were cloned into pLex5BA vector under the control of an inducible promoter. Over-expression of target proteins was confirmed. For two clones, one over-expressing FabI and the other over-expressing MurA enzymes, the host cells became 17- and 139-fold more resistant to the specific inhibitors triclosan and phosphomycin, respectively, while the susceptibility of other clones towards these inhibitors remained unchanged after induction of gene expression. Target identification via target protein over-expression was demonstrated using both mixed clone and individual clone assay formats

Osteoblast-targeted overexpression of TAZ increases bone mass in vivo.

Directory of Open Access Journals (Sweden)

Jae-Yeon Yang

Full Text Available Osteoblasts are derived from mesenchymal progenitors. Differentiation to osteoblasts and adipocytes is reciprocally regulated. Transcriptional coactivator with a PDZ-binding motif (TAZ is a transcriptional coactivator that induces differentiation of mesenchymal cells into osteoblasts while blocking differentiation into adipocytes. To investigate the role of TAZ on bone metabolism in vivo, we generated transgenic mice that overexpress TAZ under the control of the procollagen type 1 promoter (Col1-TAZ. Whole body bone mineral density (BMD of 6- to 19-week-old Col-TAZ mice was 4% to 7% higher than that of their wild-type (WT littermates, whereas no difference was noticed in Col.1-TAZ female mice. Microcomputed tomography analyses of proximal tibiae at 16 weeks of age demonstrated a significant increase in trabecular bone volume (26.7% and trabecular number (26.6% with a reciprocal decrease in trabecular spacing (14.2% in Col1-TAZ mice compared with their WT littermates. In addition, dynamic histomorphometric analysis of the lumbar spine revealed increased mineral apposition rate (42.8% and the serum P1NP level was also significantly increased (53% in Col.1-TAZ mice. When primary calvaria cells were cultured in osteogenic medium, alkaline phosphatase (ALP activity was significantly increased and adipogenesis was significantly suppressed in Col1-TAZ mice compared with their WT littermates. Quantitative real-time polymerase chain reaction analyses showed that expression of collagen type 1, bone sialoprotein, osteocalcin, ALP, osterix, and Runx2 was significantly increased in calvaria cells from Col1-TAZ mice compared to their WT littermates. In vitro, TAZ enhanced Runx2-mediated transcriptional activity while suppressing the peroxisome proliferator-activated receptor gamma signaling pathway. TAZ also enhanced transcriptional activity from 3TP-Lux, which reflects transforming growth factor-beta (TGF-β-mediated signaling. In addition, TAZ enhanced TGF

Transgenic mice overexpressing glia maturation factor-β, an oxidative stress inducible gene, show premature aging due to Zmpste24 down-regulation.

Science.gov (United States)

Imai, Rika; Asai, Kanae; Hanai, Jun-ichi; Takenaka, Masaru

2015-07-01

Glia Maturation Factor-β (GMF), a brain specific protein, is induced by proteinuria in renal tubules. Ectopic GMF overexpression causes apoptosisin vitro via cellular vulnerability to oxidative stress. In order to examine the roles of GMF in non-brain tissue, we constructed transgenic mice overexpressing GMF (GMF-TG). The GMF-TG mice exhibited appearance phenotypes associated with premature aging. The GMF-TG mice also demonstrated short lifespans and reduced hair regrowth, suggesting an accelerated aging process. The production of an abnormal lamin A, a nuclear envelope protein, plays a causal role in both normal aging and accelerated aging diseases, known as laminopathies. Importantly, we identified the abnormal lamin A (prelamin A), accompanied by a down-regulation of a lamin A processing enzyme (Zmpste24) in the kidney of the GMF-TG mice. The GMF-TG mice showed accelerated aging in the kidney, compared with wild-type mice, showing increased TGF-β1, CTGF gene and serum creatinine. The gene expression of p21/waf1 was increased at an earlier stage of life, at 10 weeks, which was in turn down-regulated at a later stage, at 60 weeks. In conclusion, we propose that GMF-TG mice might be a novel mouse model of accelerated aging, due to the abnormal lamin A.

An improved 99mTc-HYNIC-(Ser)3-LTVSPWY peptide with EDDA/tricine as co-ligands for targeting and imaging of HER2 overexpression tumor.

Science.gov (United States)

Khodadust, Fatemeh; Ahmadpour, Sajjad; Aligholikhamseh, Nazan; Abedi, Seyed Mohammad; Hosseinimehr, Seyed Jalal

2018-01-20

Overexpression of human epidermal receptor 2 (HER2) has given the opportunity for targeting and delivering of imaging radiotracers. The aim of this study was to evaluate the 99m Tc-HYNIC-(EDDA/tricine)-(Ser) 3 -LTVSPWY peptide for tumor targeting and imaging of tumor with overexpression of HER2. The HYNIC-(Ser) 3 -LTVSPWY was labeled with 99m Tc in presence of EDDA/tricine mixture as co-ligands. The in vitro and in vivo studies of this radiolabeled peptide were performed for cellular specific binding and tumor targeting. The high radiochemical purity of 99m Tc-HYNIC (EDDA/tricine)-(Ser) 3 -LTVSPWY was obtained to be 99%. It exhibited high stability in normal saline and human serum. In HER2 binding affinity study, a significant reduction in uptake of radiolabeled peptide (7.7 fold) was observed by blocking SKOV-3 cells receptors with unlabeled peptide. The K D and B max values for this radiolabeled peptide were determined as 3.3 ± 1.0 nM and 2.9 ± 0.3 × 10 6 CPM/pMol, respectively. Biodistribution study revealed tumor to blood and tumor to muscle ratios about 6.9 and 4 respectively after 4 h. Tumor imaging by gamma camera demonstrated considerable high contrast tumor uptake. This developed 99m Tc-HYNIC-(Ser) 3 -LTVSPWY peptide selectively targeted on HER2 tumor and exhibited a high target uptake combined with acceptable low background activity for tumor imaging in mice. The results of this study and its comparison with another study showed that 99m Tc-HYNIC-(EDDA/tricine)-(Ser) 3 -LTVSPWY is much better than previously reported radiolabeled peptide as 99m Tc-CSSS-LTVSPWY for HER2 overexpression tumor targeting and imaging. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Astroglial c-Myc overexpression predisposes mice to primary malignant gliomas

DEFF Research Database (Denmark)

Jensen, Niels Aagaard; Pedersen, Karen-Marie; Lihme, Frederikke

2003-01-01

Malignant astrocytomas are common human primary brain tumors that result from neoplastic transformation of astroglia or their progenitors. Here we show that deregulation of the c-Myc pathway in developing astroglia predisposes mice to malignant astrocytomas within 2-3 weeks of age. The genetically...... engineered murine (GEM) gliomas harbor a molecular signature resembling that of human primary glioblastoma multiforme, including up-regulation of epidermal growth factor receptor and Mdm2. The GEM gliomas seem to originate in an abnormal population of glial fibrillary acidic protein-expressing cells...... the neoplastic process, presumably by inducing the sustained growth of early astroglial cells. This is in contrast to most other transgenic studies in which c-Myc overexpression requires co-operating transgenes for rapid tumor induction....

Synchronization of the seminiferous epithelium after vitamin A replacement in vitamin A-deficient mice

NARCIS (Netherlands)

van Pelt, A. M.; de rooij, D. G.

1990-01-01

The effect of vitamin A deficiency and vitamin A replacement on spermatogenesis was studied in mice. Breeding pairs of Cpb-N mice were given a vitamin A-deficient diet for at least 4 wk. The born male mice received the same diet and developed signs of vitamin A deficiency at the age of 14-16 wk. At

Targeting human prostate cancer with In-111-labeled D2B IgG, F(ab ')(2) and Fab fragments in nude mice with PSMA-expressing xenografts

NARCIS (Netherlands)

Lutje, Susanne; van Rij, Catharina M.; Franssen, Gerben M.; Fracasso, Giulio; Helfrich, Wijnand; Eek, Annemarie; Oyen, Wim J.; Colombatti, Marco; Boerman, Otto C.

2014-01-01

D2B is a new monoclonal antibody directed against an extracellular domain of prostate-specific membrane antigen (PSMA), which is overexpressed in prostate cancer. The potential of D2B IgG, and F(ab)(2) and Fab fragments of this antibody for targeting prostate cancer was determined in mice bearing

Targeting human prostate cancer with (111) In-labeled D2B IgG, F(ab')2 and Fab fragments in nude mice with PSMA-expressing xenografts

NARCIS (Netherlands)

Lutje, S.; Rij, C.M. van; Franssen, G.M.; Fracasso, G.; Helfrich, W.; Eek, A.; Oyen, W.J.G.; Colombatti, M.; Boerman, O.C.

2015-01-01

D2B is a new monoclonal antibody directed against an extracellular domain of prostate-specific membrane antigen (PSMA), which is overexpressed in prostate cancer. The potential of D2B IgG, and F(ab')2 and Fab fragments of this antibody for targeting prostate cancer was determined in mice bearing

PSMA-targeted polyinosine/polycytosine vector induces prostate tumor regression and invokes an antitumor immune response in mice.

Science.gov (United States)

Langut, Yael; Talhami, Alaa; Mamidi, Samarasimhareddy; Shir, Alexei; Zigler, Maya; Joubran, Salim; Sagalov, Anna; Flashner-Abramson, Efrat; Edinger, Nufar; Klein, Shoshana; Levitzki, Alexander

2017-12-26

There is an urgent need for an effective treatment for metastatic prostate cancer (PC). Prostate tumors invariably overexpress prostate surface membrane antigen (PSMA). We designed a nonviral vector, PEI-PEG-DUPA (PPD), comprising polyethylenimine-polyethyleneglycol (PEI-PEG) tethered to the PSMA ligand, 2-[3-(1, 3-dicarboxy propyl)ureido] pentanedioic acid (DUPA), to treat PC. The purpose of PEI is to bind polyinosinic/polycytosinic acid (polyIC) and allow endosomal release, while DUPA targets PC cells. PolyIC activates multiple pathways that lead to tumor cell death and to the activation of bystander effects that harness the immune system against the tumor, attacking nontargeted neighboring tumor cells and reducing the probability of acquired resistance and disease recurrence. Targeting polyIC directly to tumor cells avoids the toxicity associated with systemic delivery. PPD selectively delivered polyIC into PSMA-overexpressing PC cells, inducing apoptosis, cytokine secretion, and the recruitment of human peripheral blood mononuclear cells (PBMCs). PSMA-overexpressing tumors in nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice with partially reconstituted immune systems were significantly shrunken following PPD/polyIC treatment, in all cases. Half of the tumors showed complete regression. PPD/polyIC invokes antitumor immunity, but unlike many immunotherapies does not need to be personalized for each patient. The potent antitumor effects of PPD/polyIC should spur its development for clinical use.

The effect of constitutive over-expression of insulin-like growth factor 1 on the cognitive function in aged mice.

Science.gov (United States)

Hu, Ankang; Yuan, Honghua; Wu, Lianlian; Chen, Renjin; Chen, Quangang; Zhang, Tengye; Wang, Zhenzhen; Liu, Peng; Zhu, Xiaorong

2016-01-15

The neurotrophic factor insulin-like growth factor (IGF)-1 promotes neurogenesis in the mammalian brain and provides protection against brain injury. However, studies regarding the effects of IGF-1 on cognitive function in aged mice remain limited. We investigated the effects of overexpression of IGF-1 specifically in neural stem cells of the hippocampal dentate gyrus on the recognitive function in 18-month-old transgenic mice. Immunohistocytochemistry and Nissl staining revealed the increased population of BrdU-positive cells as well as the upregulated expression of Nestin and neuronal nuclei (NeuN), respective markers for neural progenitors and neurons, in the hippocampus of the aged IGF-1 transgenic mice versus the wild-type, suggesting that IGF-1 overexpression promotes neurogenesis. In addition, the IGF-1 receptor (IGF-1R), the phosphorylation of Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) and extracellular signal-regulated kinase (ERK) were enhanced in the transgenic mice than in the wild-type. Transgenic mice also showed superior performance in the Morris water maze and step-down memory tests to their wild-type counterparts. Moreover, the learning and memory abilities of transgenic mice were significantly undermined with the blockage of CaMKII and ERK signaling pathway. Accordingly, our findings indicated that IGF-1 may mitigate the aged-associated cognitive decline via promoting neurogenesis in the hippocampus and activating CaMKII and ERK signaling by binding with IGF-1R. Copyright © 2015 Elsevier B.V. All rights reserved.

Lung disease phenotypes caused by overexpression of combinations of α-, β-, and γ-subunits of the epithelial sodium channel in mouse airways.

Science.gov (United States)

Livraghi-Butrico, Alessandra; Wilkinson, Kristen J; Volmer, Allison S; Gilmore, Rodney C; Rogers, Troy D; Caldwell, Ray A; Burns, Kimberlie A; Esther, Charles R; Mall, Marcus A; Boucher, Richard C; O'Neal, Wanda K; Grubb, Barbara R

2018-02-01

The epithelial Na + channel (ENaC) regulates airway surface hydration. In mouse airways, ENaC is composed of three subunits, α, β, and γ, which are differentially expressed (α > β > γ). Airway-targeted overexpression of the β subunit results in Na + hyperabsorption, causing airway surface dehydration, hyperconcentrated mucus with delayed clearance, lung inflammation, and perinatal mortality. Notably, mice overexpressing the α- or γ-subunit do not exhibit airway Na + hyperabsorption or lung pathology. To test whether overexpression of multiple ENaC subunits produced Na + transport and disease severity exceeding that of βENaC-Tg mice, we generated double (αβ, αγ, βγ) and triple (αβγ) transgenic mice and characterized their lung phenotypes. Double αγENaC-Tg mice were indistinguishable from WT littermates. In contrast, double βγENaC-Tg mice exhibited airway Na + absorption greater than that of βENaC-Tg mice, which was paralleled by worse survival, decreased mucociliary clearance, and more severe lung pathology. Double αβENaC-Tg mice exhibited Na + transport rates comparable to those of βENaC-Tg littermates. However, αβENaC-Tg mice had poorer survival and developed severe parenchymal consolidation. In situ hybridization (RNAscope) analysis revealed both alveolar and airway αENaC-Tg overexpression. Triple αβγENaC-Tg mice were born in Mendelian proportions but died within the first day of life, and the small sample size prevented analyses of cause(s) of death. Cumulatively, these results indicate that overexpression of βENaC is rate limiting for generation of pathological airway surface dehydration. Notably, airway co-overexpression of β- and γENaC had additive effects on Na + transport and disease severity, suggesting dose dependency of these two variables.

Original Research: Metabolic alterations from early life thyroxine replacement therapy in male Ames dwarf mice are transient.

Science.gov (United States)

Darcy, Justin; Fang, Yimin; Hill, Cristal M; McFadden, Sam; Sun, Liou Y; Bartke, Andrzej

2016-10-01

Ames dwarf mice are exceptionally long-lived due to a Prop1 loss of function mutation resulting in deficiency of growth hormone, thyroid-stimulating hormone and prolactin. Deficiency in thyroid-stimulating hormone and growth hormone leads to greatly reduced levels of circulating thyroid hormones and insulin-like growth factor 1, as well as a reduction in insulin secretion. Early life growth hormone replacement therapy in Ames dwarf mice significantly shortens their longevity, while early life thyroxine (T4) replacement therapy does not. Possible mechanisms by which early life growth hormone replacement therapy shortens longevity include deleterious effects on glucose homeostasis and energy metabolism, which are long lasting. A mechanism explaining why early life T4 replacement therapy does not shorten longevity remains elusive. Here, we look for a possible explanation as to why early life T4 replacement therapy does not impact longevity of Ames dwarf mice. We found that early life T4 replacement therapy increased body weight and advanced the age of sexual maturation. We also find that early life T4 replacement therapy does not impact glucose tolerance or insulin sensitivity, and any deleterious effects on oxygen consumption, respiratory quotient and heat production are transient. Lastly, we find that early life T4 replacement therapy has long-lasting effects on bone mineral density and bone mineral content. We suggest that the transient effects on energy metabolism and lack of effects on glucose homeostasis are the reasons why there is no shortening of longevity after early life T4 replacement therapy in Ames dwarf mice. © 2016 by the Society for Experimental Biology and Medicine.

Metformin normalizes the structural changes in glycogen preceding prediabetes in mice overexpressing neuropeptide Y in noradrenergic neurons.

Science.gov (United States)

Ailanen, Liisa; Bezborodkina, Natalia N; Virtanen, Laura; Ruohonen, Suvi T; Malova, Anastasia V; Okovityi, Sergey V; Chistyakova, Elizaveta Y; Savontaus, Eriika

2018-04-01

Hepatic insulin resistance and increased gluconeogenesis are known therapeutic targets of metformin, but the role of hepatic glycogen in the pathogenesis of diabetes is less clear. Mouse model of neuropeptide Y (NPY) overexpression in noradrenergic neurons (OE-NPY D βH ) with a phenotype of late onset obesity, hepatosteatosis, and prediabetes was used to study early changes in glycogen structure and metabolism preceding prediabetes. Furthermore, the effect of the anti-hyperglycemic agent, metformin (300 mg/kg/day/4 weeks in drinking water), was assessed on changes in glycogen metabolism, body weight, fat mass, and glucose tolerance. Glycogen structure was characterized by cytofluorometric analysis in isolated hepatocytes and mRNA expression of key enzymes by qPCR. OE-NPY D βH mice displayed decreased labile glycogen fraction relative to stabile fraction (the intermediate form of glycogen) suggesting enhanced glycogen cycling. This was supported by decreased filling of glucose residues in the 10th outer tier of the glycogen molecule, which suggests accelerated glycogen phosphorylation. Metformin reduced fat mass gain in both genotypes, but glucose tolerance was improved mostly in wild-type mice. However, metformin inhibited glycogen accumulation and normalized the ratio between glycogen structures in OE-NPY D βH mice indicating decreased glycogen synthesis. Furthermore, the presence of glucose residues in the 11th tier together with decreased glycogen phosphorylase expression suggested inhibition of glycogen degradation. In conclusion, structural changes in glycogen of OE-NPY D βH mice point to increased glycogen metabolism, which may predispose them to prediabetes. Metformin treatment normalizes these changes and suppresses both glycogen synthesis and phosphorylation, which may contribute to its preventive effect on the onset of diabetes.

Tet1 overexpression leads to anxiety-like behavior and enhanced fear memories via the activation of calcium-dependent cascade through Egr1 expression in mice.

Science.gov (United States)

Kwon, Wookbong; Kim, Hyeng-Soo; Jeong, Jain; Sung, Yonghun; Choi, Minjee; Park, Song; Lee, Jinhee; Jang, Soyoung; Kim, Sung Hyun; Lee, Sanggyu; Kim, Myoung Ok; Ryoo, Zae Young

2018-01-01

Ten-eleven translocation methylcytosine dioxygenase 1 ( Tet1 ) initiates DNA demethylation by converting 5-methylcytosine (5-mC) to 5-hydroxymethylcytosine (5-hmC) at CpG-rich regions of genes, which have key roles in adult neurogenesis and memory. In addition, the overexpression of Tet1 with 5-hmC alteration in patients with psychosis has also been reported, for instance in schizophrenia and bipolar disorders. The mechanism underlying Tet1 overexpression in the brain; however, is still elusive. In the present study, we found that Tet1-transgenic (Tet1-TG) mice displayed abnormal behaviors involving elevated anxiety and enhanced fear memories. We confirmed that Tet1 overexpression affected adult neurogenesis with oligodendrocyte differentiation in the hippocampal dentate gyrus of Tet1-TG mice. In addition, Tet1 overexpression induced the elevated expression of immediate early genes, such as Egr1 , c-fos , Arc , and Bdnf , followed by the activation of intracellular calcium signals ( i.e. , CamKII, ERK, and CREB) in prefrontal and hippocampal neurons. The expression of GABA receptor subunits ( Gabra2 and Gabra4 ) fluctuated in the prefrontal cortex and hippocampus. We evaluated the effects of Tet1 overexpression on intracellular calcium-dependent cascades by activating the Egr1 promoter in vitro Tet1 enhanced Egr1 expression, which may have led to alterations in Gabra2 and Gabra4 expression in neurons. Taken together, we suggest that the Tet1 overexpression in our Tet1-TG mice can be applied as an effective model for studying various stress-related diseases that show hyperactivation of intracellular calcium-dependent cascades in the brain.-Kwon, W., Kim, H.-S., Jeong, J., Sung, Y., Choi, M., Park, S., Lee, J., Jang, S., Kim, S. H., Lee, S., Kim, M. O., Ryoo, Z. Y. Tet1 overexpression leads to anxiety-like behavior and enhanced fear memories via the activation of calcium-dependent cascade through Egr1 expression in mice. © FASEB.

Tumor-targeting magnetic lipoplex delivery of short hairpin RNA suppresses IGF-1R overexpression of lung adenocarcinoma A549 cells in vitro and in vivo

Energy Technology Data Exchange (ETDEWEB)

Wang, Chunmao; Ding, Chao; Kong, Minjian [Department of Cardiothoracic Surgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009 (China); Dong, Aiqiang, E-mail: dr_dongaiqiang@sina.com [Department of Cardiothoracic Surgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009 (China); Qian, Jianfang; Jiang, Daming; Shen, Zhonghua [Department of Cardiothoracic Surgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009 (China)

2011-07-08

Highlights: {yields} We compared lipofection with magnetofection about difference of transfection efficiency on delivery a therapeutic gene in vitro and in vivo. {yields} We investigated the difference of shRNA induced by magnetofection and lipofection into A549 cell and subcutaneous tumor to knockdown IGF-1R overexpressed in A549 cell and A549 tumor. {yields} We investigated in vivo shRNA silenced IGF-1R overexpression 24, 48, and 72 h after shRNA intravenous injection into tumor-bearing mice by way of magnetofection and lipofection. {yields} Our results showed that magnetofection could achieve therapeutic gene targeted delivery into special site, which contributed to targeted gene therapy of lung cancers. -- Abstract: Liposomal magnetofection potentiates gene transfection by applying a magnetic field to concentrate magnetic lipoplexes onto target cells. Magnetic lipoplexes are self-assembling ternary complexes of cationic lipids with plasmid DNA associated with superparamagnetic iron oxide nanoparticles (SPIONs). Type1insulin-like growth factor receptor (IGF-1R), an important oncogene, is frequently overexpressed in lung cancer and mediates cancer cell proliferation and tumor growth. In this study, we evaluated the transfection efficiency (percentage of transfected cells) and therapeutic potential (potency of IGF-1R knockdown) of liposomal magnetofection of plasmids expressing GFP and shRNAs targeting IGF-1R (pGFPshIGF-1Rs) in A549 cells and in tumor-bearing mice as compared to lipofection using Lipofectamine 2000. Liposomal magnetofection provided a threefold improvement in transgene expression over lipofection and transfected up to 64.1% of A549 cells in vitro. In vitro, IGF-1R specific-shRNA transfected by lipofection inhibited IGF-1R protein by 56.1 {+-} 6% and by liposomal magnetofection by 85.1 {+-} 3%. In vivo delivery efficiency of the pGFPshIGF-1R plasmid into the tumor was significantly higher in the liposomal magnetofection group than in the

Tumor-targeting magnetic lipoplex delivery of short hairpin RNA suppresses IGF-1R overexpression of lung adenocarcinoma A549 cells in vitro and in vivo

International Nuclear Information System (INIS)

Wang, Chunmao; Ding, Chao; Kong, Minjian; Dong, Aiqiang; Qian, Jianfang; Jiang, Daming; Shen, Zhonghua

2011-01-01

Highlights: → We compared lipofection with magnetofection about difference of transfection efficiency on delivery a therapeutic gene in vitro and in vivo. → We investigated the difference of shRNA induced by magnetofection and lipofection into A549 cell and subcutaneous tumor to knockdown IGF-1R overexpressed in A549 cell and A549 tumor. → We investigated in vivo shRNA silenced IGF-1R overexpression 24, 48, and 72 h after shRNA intravenous injection into tumor-bearing mice by way of magnetofection and lipofection. → Our results showed that magnetofection could achieve therapeutic gene targeted delivery into special site, which contributed to targeted gene therapy of lung cancers. -- Abstract: Liposomal magnetofection potentiates gene transfection by applying a magnetic field to concentrate magnetic lipoplexes onto target cells. Magnetic lipoplexes are self-assembling ternary complexes of cationic lipids with plasmid DNA associated with superparamagnetic iron oxide nanoparticles (SPIONs). Type1insulin-like growth factor receptor (IGF-1R), an important oncogene, is frequently overexpressed in lung cancer and mediates cancer cell proliferation and tumor growth. In this study, we evaluated the transfection efficiency (percentage of transfected cells) and therapeutic potential (potency of IGF-1R knockdown) of liposomal magnetofection of plasmids expressing GFP and shRNAs targeting IGF-1R (pGFPshIGF-1Rs) in A549 cells and in tumor-bearing mice as compared to lipofection using Lipofectamine 2000. Liposomal magnetofection provided a threefold improvement in transgene expression over lipofection and transfected up to 64.1% of A549 cells in vitro. In vitro, IGF-1R specific-shRNA transfected by lipofection inhibited IGF-1R protein by 56.1 ± 6% and by liposomal magnetofection by 85.1 ± 3%. In vivo delivery efficiency of the pGFPshIGF-1R plasmid into the tumor was significantly higher in the liposomal magnetofection group than in the lipofection group. In vivo IGF-1R

Delivery of acid sphingomyelinase in normal and niemann-pick disease mice using intercellular adhesion molecule-1-targeted polymer nanocarriers.

Science.gov (United States)

Garnacho, Carmen; Dhami, Rajwinder; Simone, Eric; Dziubla, Thomas; Leferovich, John; Schuchman, Edward H; Muzykantov, Vladimir; Muro, Silvia

2008-05-01

Type B Niemann-Pick disease (NPD) is a multiorgan system disorder caused by a genetic deficiency of acid sphingomyelinase (ASM), for which lung is an important and challenging therapeutic target. In this study, we designed and evaluated new delivery vehicles for enzyme replacement therapy of type B NPD, consisting of polystyrene and poly(lactic-coglycolic) acid polymer nanocarriers targeted to intercellular adhesion molecule (ICAM)-1, an endothelial surface protein up-regulated in many pathologies, including type B NPD. Real-time vascular imaging using intravital microscopy and postmortem imaging of mouse organs showed rapid, uniform, and efficient binding of fluorescently labeled ICAM-1-targeted ASM nanocarriers (anti-ICAM/ASM nanocarriers) to endothelium after i.v. injection in mice. Fluorescence microscopy of lung alveoli actin, tissue histology, and 125I-albumin blood-to-lung transport showed that anti-ICAM nanocarriers cause neither detectable lung injury, nor abnormal vascular permeability in animals. Radioisotope tracing showed rapid disappearance from the circulation and enhanced accumulation of anti-ICAM/125I-ASM nanocarriers over the nontargeted naked enzyme in kidney, heart, liver, spleen, and primarily lung, both in wild-type and ASM knockout mice. These data demonstrate that ICAM-1-targeted nanocarriers may enhance enzyme replacement therapy for type B NPD and perhaps other lysosomal storage disorders.

A time-course study of long term over-expression of ARR19 in mice

Science.gov (United States)

Qamar, Imteyaz; Ahmad, Mohammad Faiz; Narayanasamy, Arul

2015-01-01

A leucine-rich protein, ARR19 (androgen receptor corepressor-19 kDa), is highly expressed in male reproductive organs and moderately in others. Previously, we have reported that ARR19 is differentially expressed in adult Leydig cells during the testis development and inhibits steroidogenesis by reducing the expression of steroidogenic enzymes. Whereas in prostate, ARR19 represses the transcriptional activity of AR (androgen receptor), it is important for male sexual differentiation and maturation in prostate and epididymis, through the recruitment of HDAC4. In this study we show that long term adenovirus mediated overexpression of ARR19 in mice testis has the potential of inhibiting the differentiation of testicular and prostatic cells by reducing the size of testis and prostate but has no effect on the growth of seminal vesicles. Further, it reduces the level of progesterone and testosterone by reducing the steroidogenic enzymes such as 3HSD, P450c17 and StAR. This is the first study reporting a time-course analysis of the implications of long term overexpression of ARR19 in mice testis and its effect on other organs such as prostate and seminal vesicles. Taken together, these results suggest that ARR19 may play an important role in the differentiation of male reproductive organs such as testis and prostate. PMID:26260329

Targeted Ablation and Reorganization of the Principal Preplate Neurons and Their Neuroblasts Identified by Golli Promoter Transgene Expression in the Neocortex of Mice

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Yuan-Yun Xie

2009-10-01

Full Text Available The present study delineates the cellular responses of dorsal pallium to targeted genetic ablation of the principal preplate neurons of the neocortex. Ganciclovir treatment during prenatal development (E11-E13; where E is embryonic day of mice selectively killed cells with shared S-phase vulnerability and targeted expression of a GPT [golli promoter transgene, linked to HSV-TK (herpes simplex virus-thymidine kinase, τ-eGFP (τ-enhanced green fluorescent protein and lacZ (lacZ galactosidase reporters] localized in preplate neurons. Morphogenetic fates of attacked neurons and neuroblasts, and their successors, were assessed by multiple labelling in time-series comparisons between ablated (HSV-TK+/0 and control (HSV-TK0/0 littermates. During ablation generation, neocortical growth was suppressed, and compensatory reorganization of non-GPT ventricular zone progenitors of dorsal pallium produced replacements for killed GPT neuroblasts. Replacement and surviving GPT neuroblasts then produced replacements for killed GPT neurons. Near-normal restoration of their complement delayed the settlement of GPT neurons into the reconstituted preplate, which curtailed the outgrowth of pioneer corticofugal axons. Based on this evidence, we conclude that specific cell killing in ablated mice can eliminate a major fraction of GPT neurons, with insignificant bystander killing. Also, replacement GPT neurons in ablated mice originate exclusively by proliferation from intermediate progenitor GPT neuroblasts, whose complement is maintained by non-GPT progenitors for inductive regulation of the total complement of GPT neurons. Finally, GPT neurons in both normal and ablated mice meet all morphogenetic criteria, including the ‘outside-in’ vertical gradient of settlement, presently used to identify principal preplate neurons. In ablated mice, delayed organization of these neurons desynchronizes and isolates developing neocortex from the rest of the brain, and

The design, construction and performance of the MICE target

International Nuclear Information System (INIS)

Booth, C N; Hodgson, P; Howlett, L; Nicholson, R; Overton, E; Robinson, M; Smith, P J; Apollonio, M; Barber, G; Dobbs, A; Leaver, J; Long, K R; Shepherd, B; Adams, D; Capocci, E; McCarron, E; Tarrant, J

2013-01-01

The pion-production target that serves the MICE Muon Beam consists of a titanium cylinder that is dipped into the halo of the ISIS proton beam. The design and construction of the MICE target system are described along with the quality-assurance procedures, electromagnetic drive and control systems, the readout electronics, and the data-acquisition system. The performance of the target is presented together with the particle rates delivered to the MICE Muon Beam. Finally, the beam loss in ISIS generated by the operation of the target is evaluated as a function of the particle rate, and the operating parameters of the target are derived.

Targeted deletion of C1q/TNF-related protein 9 increases food intake, decreases insulin sensitivity, and promotes hepatic steatosis in mice

OpenAIRE

Wei, Zhikui; Lei, Xia; Petersen, Pia S.; Aja, Susan; Wong, G. William

2014-01-01

Transgenic overexpression of CTRP9, a secreted hormone downregulated in obesity, confers striking protection against diet-induced obesity and type 2 diabetes. However, the physiological relevance of this adiponectin-related plasma protein remains undefined. Here, we used gene targeting to establish the metabolic function of CTRP9 in a physiological context. Mice lacking CTRP9 were obese and gained significantly more body weight when fed standard laboratory chow. Increased food intake, due in ...

E2F-1-Induced p53-independent apoptosis in transgenic mice

DEFF Research Database (Denmark)

Holmberg, Christian Henrik; Helin, K.; Sehested, M.

1998-01-01

The E2F transcription factors are key targets for the retinoblastoma protein, pRB. By inactivation of E2Fs, pRB prevents progression to the S phase. To test proliferative functions of E2F, we generated transgenic mice expressing human E2F-1 and/or human DP-1. When the hydroxymethyl glutaryl...... involving increased apoptosis in the germinal epithelium. This effect was potentiated by simultaneous overexpression of DP-1. Testicular atrophy as a result of overexpression of E2F-1 and DP-1 is independent of functional p53, since p53-nullizygous transgenic mice overexpressing E2F-1 and DP-1 also suffered...

Microbial metabolomics: Replacing trial-and-error by the unbiased selection and ranking of targets

NARCIS (Netherlands)

Werf, M.J. van der; Jellema, R.H.; Hankemeier, T.

2005-01-01

Microbial production strains are currently improved using a combination of random and targeted approaches. In the case of a targeted approach, potential bottlenecks, feed-back inhibition, and side-routes are removed, and other processes of interest are targeted by overexpressing or knocking-out the

CRF receptor antagonist astressin-B reverses and prevents alopecia in CRF over-expressing mice.

Directory of Open Access Journals (Sweden)

Lixin Wang

2011-02-01

Full Text Available Corticotropin-releasing factor (CRF signaling pathways are involved in the stress response, and there is growing evidence supporting hair growth inhibition of murine hair follicle in vivo upon stress exposure. We investigated whether the blockade of CRF receptors influences the development of hair loss in CRF over-expressing (OE-mice that display phenotypes of Cushing's syndrome and chronic stress, including alopecia. The non-selective CRF receptors antagonist, astressin-B (5 µg/mouse injected peripherally once a day for 5 days in 4-9 months old CRF-OE alopecic mice induced pigmentation and hair re-growth that was largely retained for over 4 months. In young CRF-OE mice, astressin-B prevented the development of alopecia that occurred in saline-treated mice. Histological examination indicated that alopecic CRF-OE mice had hair follicle atrophy and that astressin-B revived the hair follicle from the telogen to anagen phase. However, astressin-B did not show any effect on the elevated plasma corticosterone levels and the increased weights of adrenal glands and visceral fat in CRF-OE mice. The selective CRF₂ receptor antagonist, astressin₂-B had moderate effect on pigmentation, but not on hair re-growth. The commercial drug for alopecia, minoxidil only showed partial effect on hair re-growth. These data support the existence of a key molecular switching mechanism triggered by blocking peripheral CRF receptors with an antagonist to reset hair growth in a mouse model of alopecia associated with chronic stress.

Overexpression of GDNF in the uninjured DRG exerts analgesic effects on neuropathic pain following segmental spinal nerve ligation in mice.

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Takasu, Kumiko; Sakai, Atsushi; Hanawa, Hideki; Shimada, Takashi; Suzuki, Hidenori

2011-11-01

Glial cell line-derived neurotrophic factor (GDNF), a survival-promoting factor for a subset of nociceptive small-diameter neurons, has been shown to exert analgesic effects on neuropathic pain. However, its detailed mechanisms of action are still unknown. In the present study, we investigated the site-specific analgesic effects of GDNF in the neuropathic pain state using lentiviral vector-mediated GDNF overexpression in mice with left fifth lumbar (L5) spinal nerve ligation (SNL) as a neuropathic pain model. A lentiviral vector expressing both GDNF and enhanced green fluorescent protein (EGFP) was constructed and injected into the left dorsal spinal cord, uninjured fourth lumbar (L4) dorsal root ganglion (DRG), injured L5 DRG, or plantar skin of mice. In SNL mice, injection of the GDNF-EGFP-expressing lentivirus into the dorsal spinal cord or uninjured L4 DRG partially but significantly reduced the mechanical allodynia in association with an increase in GDNF protein expression in each virus injection site, whereas injection into the injured L5 DRG or plantar skin had no effects. These results suggest that GDNF exerts its analgesic effects in the neuropathic pain state by acting on the central terminals of uninjured DRG neurons and/or on the spinal cells targeted by the uninjured DRG neurons. This article shows that GDNF exerts its analgesic effects on neuropathic pain by acting on the central terminals of uninjured DRG neurons and/or on the spinal cells targeted by these neurons. Therefore, research focusing on these GDNF-dependent neurons in the uninjured DRG would provide a new strategy for treating neuropathic pain. Copyright © 2011 American Pain Society. Published by Elsevier Inc. All rights reserved.

Overexpression of cellular glutathione peroxidase rescues homocyst(e)ine-induced endothelial dysfunction

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Weiss, Norbert; Zhang, Ying-Yi; Heydrick, Stanley; Bierl, Charlene; Loscalzo, Joseph

2001-01-01

Homocyst(e)ine (Hcy) inhibits the expression of the antioxidant enzyme cellular glutathione peroxidase (GPx-1) in vitro and in vivo, which can lead to an increase in reactive oxygen species that inactivate NO and promote endothelial dysfunction. In this study, we tested the hypothesis that overexpression of GPx-1 can restore the normal endothelial phenotype in hyperhomocyst(e)inemic states. Heterozygous cystathionine β-synthase-deficient (CBS(−/+)) mice and their wild-type littermates (CBS(+/+)) were crossbred with mice that overexpress GPx-1 [GPx-1(tg+) mice]. GPx-1 activity was 28% lower in CBS(−/+)/GPx-1(tg−) compared with CBS(+/+)/GPx-1(tg−) mice (P < 0.05), and CBS(−/+) and CBS(+/+) mice overexpressing GPx-1 had 1.5-fold higher GPx-1 activity compared with GPx-1 nontransgenic mice (P < 0.05). Mesenteric arterioles of CBS(−/+)/GPx-1(tg−) mice showed vasoconstriction to superfusion with β-methacholine and bradykinin (P < 0.001 vs. all other groups), whereas nonhyperhomocyst(e)inemic mice [CBS(+/+)/GPx-1(tg−) and CBS(+/+)/GPx-1(tg+) mice] demonstrated dose-dependent vasodilation in response to both agonists. Overexpression of GPx-1 in hyperhomocyst(e)inemic mice restored the normal endothelium-dependent vasodilator response. Bovine aortic endothelial cells (BAEC) were transiently transfected with GPx-1 and incubated with dl-homocysteine (HcyH) or l-cysteine. HcyH incubation decreased GPx-1 activity in sham-transfected BAEC (P < 0.005) but not in GPx-1-transfected cells. Nitric oxide release from BAEC was significantly decreased by HcyH but not cysteine, and GPx-1 overexpression attenuated this decrease. These findings demonstrate that overexpression of GPx-1 can compensate for the adverse effects of Hcy on endothelial function and suggest that the adverse vascular effects of Hcy are at least partly mediated by oxidative inactivation of NO. PMID:11606774

Neuroglobin Overexpression Inhibits AMPK Signaling and Promotes Cell Anabolism.

Science.gov (United States)

Cai, Bin; Li, Wenjun; Mao, XiaoOu; Winters, Ali; Ryou, Myoung-Gwi; Liu, Ran; Greenberg, David A; Wang, Ning; Jin, Kunlin; Yang, Shao-Hua

2016-03-01

Neuroglobin (Ngb) is a recently discovered globin with preferential localization to neurons. Growing evidence indicates that Ngb has distinct physiological functions separate from the oxygen storage and transport roles of other globins, such as hemoglobin and myoglobin. We found increased ATP production and decreased glycolysis in Ngb-overexpressing immortalized murine hippocampal cell line (HT-22), in parallel with inhibition of AMP-activated protein kinase (AMPK) signaling and activation of acetyl-CoA carboxylase (ACC). In addition, lipid and glycogen content was increased in Ngb-overexpressing HT-22 cells. AMPK signaling was also inhibited in the brain and heart from Ngb-overexpressing transgenic mice. Although Ngb overexpression did not change glycogen content in whole brain, glycogen synthase was activated in cortical neurons of Ngb-overexpressing mouse brain and Ngb overexpression primary neurons. Moreover, lipid and glycogen content was increased in hearts derived from Ngb-overexpressing mice. These findings suggest that Ngb functions as a metabolic regulator and enhances cellular anabolism through the inhibition of AMPK signaling.

Intestine-specific overexpression of IL-10 improves survival in polymicrobial sepsis.

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Rajan, Saju; Vyas, Dinesh; Clark, Andrew T; Woolsey, Cheryl A; Clark, Jessica A; Hotchkiss, Richard S; Buchman, Timothy G; Coopersmith, Craig M

2008-04-01

Targeted IL-10 therapy improves survival in preclinical models of critical illness, and intestine-specific IL-10 decreases inflammation in models of chronic Inflammatory disease. We therefore sought to determine whether intestine-specific overexpression of IL-10 would improve survival in sepsis. Transgenic mice that overexpress IL-10 in their gut epithelium (Fabpi-IL-10 mice) and wild-type (WT) littermates (n = 127) were subjected to cecal ligation and puncture with a 27-gauge needle. The 7-day survival rate was 45% in transgenic animals and 30% in WT animals (P < or = 0.05). Systemic levels of IL-10 were undetectable in both groups of animals under basal conditions and were elevated to a similar degree in septic animals regardless of whether they expressed the transgene. Local parameter of injury, including gut epithelial apoptosis, intestinal permeability, peritoneal lavage cytokines, and stimulated cytokines from intraepithelial lymphocytes, were similar between transgenic and WT mice. However, in stimulated splenocytes, proinflammatory cytokines monocyte chemoattractant protein 1 (189 +/- 43 vs. 40 +/- 8 pg/mL) and IL-6 (116 +/- 28 vs. 34 +/- 9 pg/mL) were lower in Fabpi-IL-10 mice than WT littermates despite the intestine-specific nature of the transgene (P < 0.05). Cytokine levels were similar in blood and bronchoalveolar lavage fluid between the 2 groups, as were circulating LPS levels. Transgenic mice also had lower white blood cell counts associated with lower absolute neutrophil counts (0.5 +/- 0.1 vs. 1.0 +/- 0.2 10(3)/mm3; P < 0.05). These results indicate that gut-specific overexpression of IL-10 improves survival in a murine model of sepsis, and interactions between the intestinal epithelium and the systemic immune system may play a role in conferring this survival advantage.

Role of paraoxonase-1 in bone anabolic effects of parathyroid hormone in hyperlipidemic mice

Energy Technology Data Exchange (ETDEWEB)

Lu, Jinxiu [Department of Physiology, University of California, Los Angeles (United States); Cheng, Henry [Department of Medicine, University of California, Los Angeles (United States); Atti, Elisa [Division of Diagnostic and Surgical Sciences, School of Dentistry, University of California, Los Angeles (United States); Shih, Diana M. [Department of Medicine, University of California, Los Angeles (United States); Demer, Linda L. [Department of Physiology, University of California, Los Angeles (United States); Department of Medicine, University of California, Los Angeles (United States); Department of Bioengineering, University of California, Los Angeles (United States); Tintut, Yin, E-mail: ytintut@mednet.ucla.edu [Department of Medicine, University of California, Los Angeles (United States)

2013-02-01

Highlights: ► Anabolic effects of PTH were tested in hyperlipidemic mice overexpressing PON1. ► Expression of antioxidant regulatory genes was induced in PON1 overexpression. ► Bone resorptive activity was reduced in PON1 overexpressing hyperlipidemic mice. ► PON1 restored responsiveness to intermittent PTH in bones of hyperlipidemic mice. -- Abstract: Hyperlipidemia blunts anabolic effects of intermittent parathyroid hormone (PTH) on cortical bone, and the responsiveness to PTH are restored in part by oral administration of the antioxidant ApoA-I mimetic peptide, D-4F. To evaluate the mechanism of this rescue, hyperlipidemic mice overexpressing the high-density lipoprotein-associated antioxidant enzyme, paraoxonase 1 (Ldlr{sup −/−}PON1{sup tg}) were generated, and daily PTH injections were administered to Ldlr{sup −/−}PON1{sup tg} and to littermate Ldlr{sup −/−} mice. Expression of bone regulatory genes was determined by realtime RT-qPCR, and cortical bone parameters of the femoral bones by micro-computed tomographic analyses. PTH-treated Ldlr{sup −/−}PON1{sup tg} mice had significantly greater expression of PTH receptor (PTH1R), activating transcription factor-4 (ATF4), and osteoprotegerin (OPG) in femoral cortical bone, as well as significantly greater cortical bone mineral content, thickness, and area in femoral diaphyses compared with untreated Ldlr{sup −/−}PON1{sup tg} mice. In contrast, in control mice (Ldlr{sup −/−}) without PON1 overexpression, PTH treatment did not induce these markers. Calvarial bone of PTH-treated Ldlr{sup −/−}PON1{sup tg} mice also had significantly greater expression of osteoblastic differentiation marker genes as well as BMP-2-target and Wnt-target genes. Untreated Ldlr{sup −/−}PON1{sup tg} mice had significantly greater expression of PTHR1 than untreated Ldlr{sup −/−} mice, whereas sclerostin expression was reduced. In femoral cortical bones, expression levels of transcription factors, Fox

Thioredoxin-1 overexpression in transgenic mice attenuates streptozotocin-induced diabetic osteopenia: a novel role of oxidative stress and therapeutic implications.

Science.gov (United States)

Hamada, Yasuhiro; Fujii, Hideki; Kitazawa, Riko; Yodoi, Junji; Kitazawa, Sohei; Fukagawa, Masafumi

2009-05-01

Diabetes mellitus is associated with increased risk of osteopenia and bone fracture. However, the mechanisms accounting for diabetic bone disorder are unclear. We have previously reported that streptozotocin-induced diabetic mice develop low turnover osteopenia associated with increased oxidative stress in the diabetic condition. To determine the role of oxidative stress in the development of diabetic osteopenia, we presently investigated the effect of overexpression of thioredoxin-1 (TRX), a major intracellular antioxidant, on the development of diabetic osteopenia, using TRX transgenic mice (TRX-Tg). TRX-Tg are C57BL/6 mice that carry the human TRX transgene under the control of beta-actin promoter. Eight-week-old male TRX-Tg mice and wild type (WT) littermates were intraperitoneally injected with either streptozotocin or vehicle. Mice were grouped as 1) non-diabetic WT, 2) non-diabetic TRX-Tg, 3) diabetic WT, and 4) diabetic TRX-Tg. After 12 weeks of streptozotocin treatment, oxidative stress on the whole body and bone was evaluated, and the physical properties of the femora, and histomorphometry parameters of the tibiae were assessed. TRX overexpression did not affect either body weight or hemoglobin A1c levels. There were no significant differences in renal function and in serum levels of calcium, phosphate, and intact parathyroid hormone among the four groups. On the other hand, urinary excretion of 8-hydroxydeoxyguanosine (8-OHdG), a marker of oxidative DNA damage, was significantly elevated in diabetic WT and attenuated in diabetic TRX-Tg. Immunohistochemical staining for 8-OHdG revealed marked intensity in the bone tissue of diabetic WT compared with non-diabetic WT, while staining was attenuated in diabetic TRX-Tg. TRX overexpression partially restored reduced bone mineral density and prevented the suppression of bone formation observed in diabetic WT. Increased oxidative stress in diabetic condition contributes to the development of diabetic osteopenia

Transgenic Mice Over-Expressing RBP4 Have RBP4-Dependent and Light-Independent Retinal Degeneration.

Science.gov (United States)

Du, Mei; Phelps, Eric; Balangue, Michael J; Dockins, Aaron; Moiseyev, Gennadiy; Shin, Younghwa; Kane, Shelley; Otalora, Laura; Ma, Jian-Xing; Farjo, Rafal; Farjo, Krysten M

2017-08-01

Transgenic mice overexpressing serum retinol-binding protein (RBP4-Tg) develop progressive retinal degeneration, characterized by microglia activation, yet the precise mechanisms underlying retinal degeneration are unclear. Previous studies showed RBP4-Tg mice have normal ocular retinoid levels, suggesting that degeneration is independent of the retinoid visual cycle or light exposure. The present study addresses whether retinal degeneration is light-dependent and RBP4-dependent by testing the effects of dark-rearing and pharmacological lowering of serum RBP4 levels, respectively. RBP4-Tg mice reared on normal mouse chow in normal cyclic light conditions were directly compared to RBP4-Tg mice exposed to chow supplemented with the RBP4-lowering compound A1120 or dark-rearing conditions. Quantitative retinal histological analysis was conducted to assess retinal degeneration, and electroretinography (ERG) and optokinetic tracking (OKT) tests were performed to assess retinal and visual function. Ocular retinoids and bis-retinoid A2E were quantified. Dark-rearing RBP4-Tg mice effectively reduced ocular bis-retinoid A2E levels, but had no significant effect on retinal degeneration or dysfunction in RBP4-Tg mice, demonstrating that retinal degeneration is light-independent. A1120 treatment lowered serum RBP4 levels similar to wild-type mice, and prevented structural retinal degeneration. However, A1120 treatment did not prevent retinal dysfunction in RBP4-Tg mice. Moreover, RBP4-Tg mice on A1120 diet had significant worsening of OKT response and loss of cone photoreceptors compared to RBP4-Tg mice on normal chow. This may be related to the very significant reduction in retinyl ester levels in the retina of mice on A1120-supplemented diet. Retinal degeneration in RBP4-Tg mice is RBP4-dependent and light-independent.

Progranulin overexpression in sensory neurons attenuates neuropathic pain in mice: Role of autophagy.

Science.gov (United States)

Altmann, Christine; Hardt, Stefanie; Fischer, Caroline; Heidler, Juliana; Lim, Hee-Young; Häussler, Annett; Albuquerque, Boris; Zimmer, Béla; Möser, Christine; Behrends, Christian; Koentgen, Frank; Wittig, Ilka; Schmidt, Mirko H H; Clement, Albrecht M; Deller, Thomas; Tegeder, Irmgard

2016-12-01

Peripheral or central nerve injury is a frequent cause of chronic pain and the mechanisms are not fully understood. Using newly generated transgenic mice we show that progranulin overexpression in sensory neurons attenuates neuropathic pain after sciatic nerve injury and accelerates nerve healing. A yeast-2-hybrid screen revealed putative interactions of progranulin with autophagy-related proteins, ATG12 and ATG4b. This was supported by colocalization and proteomic studies showing regulations of ATG13 and ATG4b and other members of the autophagy network, lysosomal proteins and proteins involved in endocytosis. The association of progranulin with the autophagic pathway was functionally confirmed in primary sensory neurons. Autophagy and survival were impaired in progranulin-deficient neurons and improved in progranulin overexpressing neurons. Nerve injury in vivo caused an accumulation of LC3b-EGFP positive bodies in neurons of the dorsal root ganglia and nerves suggesting an impairment of autophagic flux. Overexpression of progranulin in these neurons was associated with a reduction of the stress marker ATF3, fewer protein aggregates in the injured nerve and enhanced stump healing. At the behavioral level, further inhibition of the autophagic flux by hydroxychloroquine intensified cold and heat nociception after sciatic nerve injury and offset the pain protection provided by progranulin. We infer that progranulin may assist in removal of protein waste and thereby helps to resolve neuropathic pain after nerve injury. Copyright © 2016 Elsevier Inc. All rights reserved.

Enhanced Stress Response in 5-HT1AR Overexpressing Mice: Altered HPA Function and Hippocampal Long-Term Potentiation.

Science.gov (United States)

Pilar-Cuéllar, Fuencisla; Vidal, Rebeca; Díaz, Álvaro; Garro-Martínez, Emilio; Linge, Raquel; Castro, Elena; Haberzettl, Robert; Fink, Heidrun; Bert, Bettina; Brosda, Jan; Romero, Beatriz; Crespo-Facorro, Benedicto; Pazos, Ángel

2017-11-15

Postsynaptic 5-HT 1A receptors (5-HT 1A R) play an important role in anxiety and stress, although their contribution is still controversial. Previous studies report that mice overexpressing postsynaptic 5-HT 1A Rs show no changes in basal anxiety, though the influence of stress conditions has not been addressed yet. In this study, we used this animal model to evaluate the role of 5-HT 1A Rs in anxiety response after pre-exposure to an acute stressor. Under basal conditions, 5-HT 1A R overexpressing animals presented high corticosterone levels and a lower mineralocorticoid/glucocorticoid receptor ratio. After pre-exposure to a single stressor, they showed a high anxiety-like response, associated with a blunted increase in corticosterone levels and higher c-Fos activation in the prefrontal cortex. Moreover, these mice also presented a lack of downregulation of hippocampal long-term potentiation after stress exposure. Therefore, higher postsynaptic 5-HT 1A R activation might predispose to a high anxious phenotype and an impaired stress coping behavior.

miR-630 targets IGF1R to regulate response to HER-targeting drugs and overall cancer cell progression in HER2 over-expressing breast cancer.

Science.gov (United States)

Corcoran, Claire; Rani, Sweta; Breslin, Susan; Gogarty, Martina; Ghobrial, Irene M; Crown, John; O'Driscoll, Lorraine

2014-03-24

While the treatment of HER2 over-expressing breast cancer with recent HER-targeted drugs has been highly effective for some patients, primary (also known as innate) or acquired resistance limits the success of these drugs. microRNAs have potential as diagnostic, prognostic and predictive biomarkers, as well as replacement therapies. Here we investigated the role of microRNA-630 (miR-630) in breast cancer progression and as a predictive biomarker for response to HER-targeting drugs, ultimately yielding potential as a therapeutic approach to add value to these drugs. We investigated the levels of intra- and extracellular miR-630 in cells and conditioned media from breast cancer cell lines with either innate- or acquired- resistance to HER-targeting lapatinib and neratinib, compared to their corresponding drug sensitive cell lines, using qPCR. To support the role of miR-630 in breast cancer, we examined the clinical relevance of this miRNA in breast cancer tumours versus matched peritumours. Transfection of miR-630 mimics and inhibitors was used to manipulate the expression of miR-630 to assess effects on response to HER-targeting drugs (lapatinib, neratinib and afatinib). Other phenotypic changes associated with cellular aggressiveness were evaluated by motility, invasion and anoikis assays. TargetScan prediction software, qPCR, immunoblotting and ELISAs, were used to assess miR-630's regulation of mRNA, proteins and their phosphorylated forms. We established that introducing miR-630 into cells with innate- or acquired- resistance to HER-drugs significantly restored the efficacy of lapatinib, neratinib and afatinib; through a mechanism which we have determined to, at least partly, involve miR-630's regulation of IGF1R. Conversely, we demonstrated that blocking miR-630 induced resistance/insensitivity to these drugs. Cellular motility, invasion, and anoikis were also observed as significantly altered by miR-630 manipulation, whereby introducing miR-630 into cells

Targeted gene deletion of miRNAs in mice by TALEN system.

Science.gov (United States)

Takada, Shuji; Sato, Tempei; Ito, Yoshiaki; Yamashita, Satoshi; Kato, Tomoko; Kawasumi, Miyuri; Kanai-Azuma, Masami; Igarashi, Arisa; Kato, Tomomi; Tamano, Moe; Asahara, Hiroshi

2013-01-01

Mice are among the most valuable model animal species with an enormous amount of heritage in genetic modification studies. However, targeting genes in mice is sometimes difficult, especially for small genes, such as microRNAs (miRNAs) and targeting genes in repeat sequences. Here we optimized the application of TALEN system for mice and successfully obtained gene targeting technique in mice for intergenic region and series of microRNAs. Microinjection of synthesized RNA of TALEN targeting each gene in one cell stage of embryo was carried out and injected oocytes were transferred into pseudopregnant ICR female mice, producing a high success rate of the targeted deletion of miRNA genes. In our condition, TALEN RNA without poly(A) tail worked better than that of with poly(A) tail. This mutated allele in miRNA was transmitted to the next generation, suggesting the successful germ line transmission of this targeting method. Consistent with our notion of miRNAs maturation mechanism, in homozygous mutant mice of miR-10a, the non- mutated strand of miRNAs expression was completely diminished. This method will lead us to expand and accelerate our genetic research using mice in a high throughput way.

Transgenic overexpression of ADAM12 suppresses muscle regeneration and aggravates dystrophy in aged mdx mice

DEFF Research Database (Denmark)

Jørgensen, Louise Helskov; Jensen, Charlotte Harken; Wewer, Ulla M

2007-01-01

mice (ADAM12(+)) after a knife cut lesion and observed that the regeneration process was significantly impaired. ADAM12 seemed to inhibit the satellite cell response and delay myoblast differentiation. These results discourage long-term therapeutic use of ADAM12. They also point to impaired...... effect of ADAM12 was suggested to be mediated via a membrane-stabilizing up-regulation of utrophin, alpha7B integrin, and dystroglycans. Ectopic ADAM12 expression in normal mouse skeletal muscle also improved regeneration after freeze injury, presumably by the same mechanism. Hence, it was suggested...... overexpressing ADAM12 (ADAM12(+)/mdx mice), even though their utrophin levels were mildly elevated compared with age-matched controls. Thus, membrane stabilization was not sufficient to provide protection during prolonged disease. Consequently, we reinvestigated skeletal muscle regeneration in ADAM12 transgenic...

Cognition, learning behaviour and hippocampal synaptic plasticity are not disrupted in mice over-expressing the cholesterol transporter ABCG1

Directory of Open Access Journals (Sweden)

Eadie Brennan D

2009-02-01

Full Text Available Abstract Background Cognitive deficits are a hallmark feature of both Down Syndrome (DS and Alzheimer's Disease (AD. Extra copies of the genes on chromosome 21 may also play an important role in the accelerated onset of AD in DS individuals. Growing evidence suggests an important function for cholesterol in the pathogenesis of AD, particularly in APP metabolism and production of Aβ peptides. The ATP-Binding Cassette-G1 (ABCG1 transporter is located on chromosome 21, and participates in the maintenance of tissue cholesterol homeostasis. Results To assess the role of ABCG1 in DS-related cognition, we evaluated the cognitive performance of mice selectively over-expressing the ABCG1 gene from its endogenous regulatory signals. Both wild-type and ABCG1 transgenic mice performed equivalently on several behavioral tests, including measures of anxiety, as well as on reference and working memory tasks. No deficits in hippocampal CA1 synaptic plasticity as determined with electrophysiological studies were apparent in mice over-expressing ABCG1. Conclusion These findings indicate that although ABCG1 may play a role in maintaining cellular or tissue cholesterol homeostasis, it is unlikely that excess ABCG1 expression contributes to the cognitive deficits in DS individuals.

Early thymic T cell development in young transgenic mice overexpressing human Cu/Zn superoxide dismutase, a model of Down syndrome.

Science.gov (United States)

Laurent, Julien; Paly, Evelyne; Marche, Patrice N; London, Jacqueline

2006-06-01

Previous studies have shown that transgenic mice overexpressing Cu/Zn superoxide dismutase, a model of Down syndrome, exhibit premature thymic involution. We have performed a flow cytometry analysis of the developing thymus in these homozygous transgenic mice (hSOD1/hSOD1: Tg-SOD). Longitudinal follow-up analysis from day 3 to day 280 showed an early thymic development in Tg-SOD mice compared with controls. This early thymic development was associated with an increased migration of mature T cells to peripheral lymphoid organs. BrdU labeling showed no difference between Tg-SOD and control mice, confirming that the greater number of peripheral T cells in Tg-SOD mice was not due to extensive proliferation of these cells but rather to a greater pool of emigrant T cells in Tg-SOD.

Mice overexpressing both non-mutated human SOD1 and mutated SOD1G93A genes: a competent experimental model for studying iron metabolism in amyotrophic lateral sclerosis

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Anna eGajowiak

2016-01-01

Full Text Available Amyotrophic lateral sclerosis (ALS is a progressive neurodegenerative disease characterized by degeneration and loss of motor neurons in the spinal cord, brainstem and motor cortex. Up to 10% of ALS cases are inherited (familial, fALS and associated with mutations, frequently in the superoxide dismutase 1 (SOD1 gene. Rodent transgenic models of ALS are often used to elucidate a complex pathogenesis of this disease. Of importance, both ALS patients and animals carrying mutated human SOD1 gene show symptoms of oxidative stress and iron metabolism misregulation. The aim of our study was to characterize changes in iron metabolism in one of the most commonly used models of ALS – transgenic mice overexpressing human mutated SOD1G93A gene. We analyzed the expression of iron-related genes in asymptomatic, 2-month old and symptomatic, 4-month old SOD1G93A mice. In parallel, respective age-matched mice overexpressing human non-mutated SOD1 transgene and control mice were analyzed. We demonstrate that the overexpression of both SOD1 and SOD1G93A genes account for a substantial increase in SOD1 protein levels and activity in selected tissues and that not all the changes in iron metabolism genes expression are specific for the overexpression of the mutated form of SOD1.

Targeted gene deletion of miRNAs in mice by TALEN system.

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Shuji Takada

Full Text Available Mice are among the most valuable model animal species with an enormous amount of heritage in genetic modification studies. However, targeting genes in mice is sometimes difficult, especially for small genes, such as microRNAs (miRNAs and targeting genes in repeat sequences. Here we optimized the application of TALEN system for mice and successfully obtained gene targeting technique in mice for intergenic region and series of microRNAs. Microinjection of synthesized RNA of TALEN targeting each gene in one cell stage of embryo was carried out and injected oocytes were transferred into pseudopregnant ICR female mice, producing a high success rate of the targeted deletion of miRNA genes. In our condition, TALEN RNA without poly(A tail worked better than that of with poly(A tail. This mutated allele in miRNA was transmitted to the next generation, suggesting the successful germ line transmission of this targeting method. Consistent with our notion of miRNAs maturation mechanism, in homozygous mutant mice of miR-10a, the non- mutated strand of miRNAs expression was completely diminished. This method will lead us to expand and accelerate our genetic research using mice in a high throughput way.

Metabolomic Analysis of the Skeletal Muscle of Mice Overexpressing PGC-1α.

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Yukino Hatazawa

Full Text Available Peroxisome proliferator-activated receptor (PPAR γ coactivator 1α (PGC-1α is a coactivator of various nuclear receptors and other transcription factors whose expression increases in the skeletal muscle during exercise. We have previously made transgenic mice overexpressing PGC-1α in the skeletal muscle (PGC-1α-Tg mice. PGC-1α upregulates the expression of genes associated with red fibers, mitochondrial function, fatty acid oxidation, and branched chain amino acid (BCAA degradation. However, global analyses of the actual metabolic products have not been investigated. In this study, we conducted metabolomic analysis of the skeletal muscle in PGC-1α-Tg mice by capillary electrophoresis with electrospray ionization time-of-flight mass spectrometry. Principal component analysis and hierarchical cluster analysis showed clearly distinguishable changes in the metabolites between PGC-1α-Tg and wild-type control mice. Changes were observed in metabolite levels of various metabolic pathways such as the TCA cycle, pentose phosphate pathway, nucleotide synthesis, purine nucleotide cycle, and amino acid metabolism, including BCAA and β-alanine. Namely, metabolic products of the TCA cycle increased in PGC-1α-Tg mice, with increased levels of citrate (2.3-fold, succinate (2.2-fold, fumarate (2.8-fold, and malate (2.3-fold observed. Metabolic products associated with the pentose phosphate pathway and nucleotide biosynthesis also increased in PGC-1α-Tg mice. Meanwhile, BCAA levels decreased (Val, 0.7-fold; Leu, 0.8-fold; and Ile, 0.7-fold, and Glu (3.1-fold and Asp (2.2-fold levels increased. Levels of β-alanine and related metabolites were markedly decreased in PGC-1α-Tg mice. Coordinated regulation of the TCA cycle and amino acid metabolism, including BCAA, suggests that PGC-1α plays important roles in energy metabolism. Moreover, our metabolomics data showing the activation of the purine nucleotide pathway, malate-aspartate shuttle, as well as

Atypical scrapie prions from sheep and lack of disease in transgenic mice overexpressing human prion protein.

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Wadsworth, Jonathan D F; Joiner, Susan; Linehan, Jacqueline M; Balkema-Buschmann, Anne; Spiropoulos, John; Simmons, Marion M; Griffiths, Peter C; Groschup, Martin H; Hope, James; Brandner, Sebastian; Asante, Emmanuel A; Collinge, John

2013-11-01

Public and animal health controls to limit human exposure to animal prions are focused on bovine spongiform encephalopathy (BSE), but other prion strains in ruminants may also have zoonotic potential. One example is atypical/Nor98 scrapie, which evaded statutory diagnostic methods worldwide until the early 2000s. To investigate whether sheep infected with scrapie prions could be another source of infection, we inoculated transgenic mice that overexpressed human prion protein with brain tissue from sheep with natural field cases of classical and atypical scrapie, sheep with experimental BSE, and cattle with BSE. We found that these mice were susceptible to BSE prions, but disease did not develop after prolonged postinoculation periods when mice were inoculated with classical or atypical scrapie prions. These data are consistent with the conclusion that prion disease is less likely to develop in humans after exposure to naturally occurring prions of sheep than after exposure to epizootic BSE prions of ruminants.

Skeletal muscle-specific overexpression of IGFBP-2 promotes a slower muscle phenotype in healthy but not dystrophic mdx mice and does not affect the dystrophic pathology.

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Swiderski, Kristy; Martins, Karen Janet Bernice; Chee, Annabel; Trieu, Jennifer; Naim, Timur; Gehrig, Stefan Martin; Baum, Dale Michael; Brenmoehl, Julia; Chau, Luong; Koopman, René; Gregorevic, Paul; Metzger, Friedrich; Hoeflich, Andreas; Lynch, Gordon Stuart

The insulin-like growth factor binding proteins (IGFBPs) are thought to modulate cell size and homeostasis via IGF-I-dependent and -independent pathways. There is a considerable dearth of information regarding the function of IGFBPs in skeletal muscle, particularly their role in the pathophysiology of Duchenne muscular dystrophy (DMD). In this study we tested the hypothesis that intramuscular IGFBP-2 overexpression would ameliorate the pathology in mdx dystrophic mice. 4week old male C57Bl/10 and mdx mice received a single intramuscular injection of AAV6-empty or AAV6-IGFBP-2 vector into the tibialis anterior muscle. At 8weeks post-injection the effect of IGFBP-2 overexpression on the structure and function of the injected muscle was assessed. AAV6-mediated IGFBP-2 overexpression in the tibialis anterior (TA) muscles of 4-week-old C57BL/10 and mdx mice reduced the mass of injected muscle after 8weeks, inducing a slower muscle phenotype in C57BL/10 but not mdx mice. Analysis of inflammatory and fibrotic gene expression revealed no changes between control and IGFBP-2 injected muscles in dystrophic (mdx) mice. Together these results indicate that the IGFBP-2-induced promotion of a slower muscle phenotype is impaired in muscles of dystrophin-deficient mdx mice, which contributes to the inability of IGFBP-2 to ameliorate the dystrophic pathology. The findings implicate the dystrophin-glycoprotein complex (DGC) in the signaling required for this adaptation. Copyright © 2016 Elsevier Ltd. All rights reserved.

The targeted transduction of MMP-overexpressing tumor cells by ACPP-HPMA copolymer-coated adenovirus conjugates.

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Shuhua Li

Full Text Available We have designed and tested a new way to selectively deliver HPMA polymer-coated adenovirus type 5 (Ad5 particles into matrix metalloproteinase (MMP-overexpressing tumor cells. An activatable cell penetrating peptide (ACPP was designed and attached to the reactive 4-nitrophenoxy groups of HPMA polymers by the C-terminal amino acid (asparagine, N. ACPPs are activatable cell penetrating peptides (CPPs with a linker between polycationic and polyanionic domains, and MMP-mediated cleavage releases the CPP portion and its attached cargo to enable cell entry. Our data indicate that the transport of these HPMA polymer conjugates by a single ACPP molecule to the cytoplasm occurs via a nonendocytotic and concentration-independent process. The uptake was observed to finish within 20 minutes by inverted fluorescence microscopy. In contrast, HPMA polymer-coated Ad5 without ACPPs was internalized solely by endocytosis. The optimal formulation was not affected by the presence of Ad5 neutralizing antibodies during transduction, and ACPP/polymer-coated Ad5 also retained high targeting capability to several MMP-overexpressing tumor cell types. For the first time, ACPP-mediated cytoplasmic delivery of polymer-bound Ad5 to MMP-overexpressing tumor cells was demonstrated. These findings are significant, as they demonstrate the use of a polymer-based system for the targeted delivery into MMP-overexpressing solid tumors and highlight how to overcome major cellular obstacles to achieve intracellular macromolecular delivery.

Attenuation of teratoma formation by p27 overexpression in induced pluripotent stem cells.

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Matsu-ura, Toru; Sasaki, Hiroshi; Okada, Motoi; Mikoshiba, Katsuhiko; Ashraf, Muhammad

2016-02-15

Pluripotent stem cells, such as embryonic stem cells or induced pluripotent stem cells, have a great potential for regenerative medicine. Induced pluripotent stem cells, in particular, are suitable for replacement of tissue by autologous transplantation. However, tumorigenicity is a major risk in clinical application of both embryonic stem cells and induced pluripotent stem cells. This study explores the possibility of manipulating the cell cycle for inhibition of tumorigenicity. We genetically modified mouse induced pluripotent stem cells (miPSCs) to overexpress p27 tumor suppressor and examined their proliferation rate, gene expression, cardiac differentiation, tumorigenicity, and therapeutic potential in a mouse model of coronary artery ligation. Overexpression of p27 inhibited cell division of miPSCs, and that inhibition was dependent on the expression level of p27. p27 overexpressing miPSCs had pluripotency characteristics but lost stemness earlier than normal miPSCs during embryoid body and teratoma formation. These cellular characteristics led to none or smaller teratoma when the cells were injected into nude mice. Transplantation of both miPSCs and p27 overexpressing miPSCs into the infarcted mouse heart reduced the infarction size and improved left ventricular function. The overexpression of p27 attenuated tumorigenicity by reducing proliferation and earlier loss of stemness of miPSCs. The overexpression of p27 did not affect pluripotency and differentiation characteristics of miPSC. Therefore, regulation of the proliferation rate of miPSCs offers great therapeutic potential for repair of the injured myocardium.

Data file of a deep proteome analysis of the prefrontal cortex in aged mice with progranulin deficiency or neuronal overexpression of progranulin.

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Heidler, Juliana; Hardt, Stefanie; Wittig, Ilka; Tegeder, Irmgard

2016-12-01

Progranulin deficiency is associated with neurodegeneration in humans and in mice. The mechanisms likely involve progranulin-promoted removal of protein waste via autophagy. We performed a deep proteomic screen of the pre-frontal cortex in aged (13-15 months) female progranulin-deficient mice (GRN -/- ) and mice with inducible neuron-specific overexpression of progranulin (SLICK-GRN-OE) versus the respective control mice. Proteins were extracted and analyzed per liquid chromatography/mass spectrometry (LC/MS) on a Thermo Scientific™ Q Exactive Plus equipped with an ultra-high performance liquid chromatography unit and a Nanospray Flex Ion-Source. Full Scan MS-data were acquired using Xcalibur and raw files were analyzed using the proteomics software Max Quant. The mouse reference proteome set from uniprot (June 2015) was used to identify peptides and proteins. The DiB data file is a reduced MaxQuant output and includes peptide and protein identification, accession numbers, protein and gene names, sequence coverage and label free quantification (LFQ) values of each sample. Differences in protein expression in genotypes are presented in "Progranulin overexpression in sensory neurons attenuates neuropathic pain in mice: Role of autophagy" (C. Altmann, S. Hardt, C. Fischer, J. Heidler, H.Y. Lim, A. Haussler, B. Albuquerque, B. Zimmer, C. Moser, C. Behrends, F. Koentgen, I. Wittig, M.H. Schmidt, A.M. Clement, T. Deller, I. Tegeder, 2016) [1].

Data file of a deep proteome analysis of the prefrontal cortex in aged mice with progranulin deficiency or neuronal overexpression of progranulin

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Juliana Heidler

2016-12-01

Full Text Available Progranulin deficiency is associated with neurodegeneration in humans and in mice. The mechanisms likely involve progranulin-promoted removal of protein waste via autophagy. We performed a deep proteomic screen of the pre-frontal cortex in aged (13–15 months female progranulin-deficient mice (GRN−/− and mice with inducible neuron-specific overexpression of progranulin (SLICK-GRN-OE versus the respective control mice. Proteins were extracted and analyzed per liquid chromatography/mass spectrometry (LC/MS on a Thermo Scientific™ Q Exactive Plus equipped with an ultra-high performance liquid chromatography unit and a Nanospray Flex Ion-Source. Full Scan MS-data were acquired using Xcalibur and raw files were analyzed using the proteomics software Max Quant. The mouse reference proteome set from uniprot (June 2015 was used to identify peptides and proteins. The DiB data file is a reduced MaxQuant output and includes peptide and protein identification, accession numbers, protein and gene names, sequence coverage and label free quantification (LFQ values of each sample. Differences in protein expression in genotypes are presented in "Progranulin overexpression in sensory neurons attenuates neuropathic pain in mice: Role of autophagy" (C. Altmann, S. Hardt, C. Fischer, J. Heidler, H.Y. Lim, A. Haussler, B. Albuquerque, B. Zimmer, C. Moser, C. Behrends, F. Koentgen, I. Wittig, M.H. Schmidt, A.M. Clement, T. Deller, I. Tegeder, 2016 [1].

Nanotized PPARα Overexpression Targeted to Hypertrophied Myocardium Improves Cardiac Function by Attenuating the p53-GSK3β-Mediated Mitochondrial Death Pathway.

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Rana, Santanu; Datta, Ritwik; Chaudhuri, Ratul Datta; Chatterjee, Emeli; Chawla-Sarkar, Mamta; Sarkar, Sagartirtha

2018-05-09

Metabolic remodeling of cardiac muscles during pathological hypertrophy is characterized by downregulation of fatty acid oxidation (FAO) regulator, peroxisome proliferator-activated receptor alpha (PPARα). Thereby, we hypothesized that a cardiac-specific induction of PPARα might restore the FAO-related protein expression and resultant energy deficit. In the present study, consequences of PPARα augmentation were evaluated for amelioration of chronic oxidative stress, myocyte apoptosis, and cardiac function during pathological cardiac hypertrophy. Nanotized PPARα overexpression targeted to myocardium was done by a stearic acid-modified carboxymethyl-chitosan (CMC) conjugated to a 20-mer myocyte-targeted peptide (CMCP). Overexpression of PPARα ameliorated pathological hypertrophy and improved cardiac function. Augmented PPARα in hypertrophied myocytes revealed downregulated p53 acetylation (lys 382), leading to reduced apoptosis. Such cells showed increased binding of PPARα with p53 that in turn reduced interaction of p53 with glycogen synthase kinase-3β (GSK3β), which upregulated inactive phospho-GSK3β (serine [Ser]9) expression within mitochondrial protein fraction. Altogether, the altered molecular milieu in PPARα-overexpressed hypertrophy groups restored mitochondrial structure and function both in vitro and in vivo. Cardiomyocyte-targeted overexpression of a protein of interest (PPARα) by nanotized plasmid has been described for the first time in this study. Our data provide a novel insight towards regression of pathological hypertrophy by ameliorating mitochondrial oxidative stress in targeted PPARα-overexpressed myocardium. PPARα-overexpression during pathological hypertrophy showed substantial betterment of mitochondrial structure and function, along with downregulated apoptosis. Myocardium-targeted overexpression of PPARα during pathological cardiac hypertrophy led to an overall improvement of cardiac energy deficit and subsequent cardiac

Eμ/miR-125b transgenic mice develop lethal B-cell malignancies.

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Enomoto, Y; Kitaura, J; Hatakeyama, K; Watanuki, J; Akasaka, T; Kato, N; Shimanuki, M; Nishimura, K; Takahashi, M; Taniwaki, M; Haferlach, C; Siebert, R; Dyer, M J S; Asou, N; Aburatani, H; Nakakuma, H; Kitamura, T; Sonoki, T

2011-12-01

MicroRNA-125b-1 (miR-125b-1) is a target of a chromosomal translocation t(11;14)(q24;q32) recurrently found in human B-cell precursor acute lymphoblastic leukemia (BCP-ALL). This translocation results in overexpression of miR-125b controlled by immunoglobulin heavy chain gene (IGH) regulatory elements. In addition, we found that six out of twenty-one BCP-ALL patients without t(11;14)(q24;q32) showed overexpression of miR-125b. Interestingly, four out of nine patients with BCR/ABL-positive BCP-ALL and one patient with B-cell lymphoid crisis that had progressed from chronic myelogenous leukemia overexpressed miR-125b. To examine the role of the deregulated expression of miR-125b in the development of B-cell tumor in vivo, we generated transgenic mice mimicking the t(11;14)(q24;q32) (Eμ/miR-125b-TG mice). Eμ/miR-125b-TG mice overexpressed miR-125b driven by IGH enhancer and promoter and developed IgM-negative or IgM-positive lethal B-cell malignancies with clonal proliferation. B cells obtained from the Eμ/miR-125b-TG mice were resistant to apoptosis induced by serum starvation. We identified Trp53inp1, a pro-apoptotic gene induced by cell stress, as a novel target gene of miR-125b in hematopoietic cells in vitro and in vivo. Our results provide direct evidence that miR-125b has important roles in the tumorigenesis of precursor B cells.

EBI2 overexpression in mice leads to B1 B-cell expansion and chronic lymphocytic leukemia-like B-cell malignancies.

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Niss Arfelt, Kristine; Barington, Line; Benned-Jensen, Tau; Kubale, Valentina; Kovalchuk, Alexander L; Daugvilaite, Viktorija; Christensen, Jan Pravsgaard; Thomsen, Allan Randrup; Egerod, Kristoffer L; Bassi, Maria R; Spiess, Katja; Schwartz, Thue W; Wang, Hongsheng; Morse, Herbert C; Holst, Peter J; Rosenkilde, Mette M

2017-02-16

Human and mouse chronic lymphocytic leukemia (CLL) develops from CD5 + B cells that in mice and macaques are known to define the distinct B1a B-cell lineage. B1a cells are characterized by lack of germinal center (GC) development, and the B1a cell population is increased in mice with reduced GC formation. As a major mediator of follicular B-cell migration, the G protein-coupled receptor Epstein-Barr virus-induced gene 2 ( EBI2 or GPR183 ) directs B-cell migration in the lymphoid follicles in response to its endogenous ligands, oxysterols. Thus, upregulation of EBI2 drives the B cells toward the extrafollicular area, whereas downregulation is essential for GC formation. We therefore speculated whether increased expression of EBI2 would lead to an expanded B1 cell subset and, ultimately, progression to CLL. Here, we demonstrate that B-cell-targeted expression of human EBI2 (hEBI2) in mice reduces GC-dependent immune responses, reduces total immunoglobulin M (IgM) and IgG levels, and leads to increased proliferation and upregulation of cellular oncogenes. Furthermore, hEBI2 overexpression leads to an abnormally expanded CD5 + B1a B-cell subset (present as early as 4 days after birth), late-onset lymphoid cancer development, and premature death. These findings are highly similar to those observed in CLL patients and identify EBI2 as a promoter of B-cell malignancies.

Replacing Fish Oil with Vegetable Oils in Salmon Feed Increases Hepatic Lipid Accumulation and Reduces Insulin Sensitivity in Mice

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Midtbø, Lisa Kolden

Background: Due to a growing global aquaculture production, fish oil (FO) and fish meal (FM) are partly replaced with vegetable ingredients in aqua feed for Atlantic salmon. These replacements in the feed lead to an altered fatty acid composition in the salmon fillet. We aimed to investigate how...... these changes affects obesity development and insulin sensitivity in mice eating the salmon. In addition, we wanted to investigate how the background diet affects the antiobesity effect of FO. Results: Western diets (WDs) were produced containing salmon fed either FO (WD-FO), or with partly replacement (80......%) of FO with different vegetable oils (VOs); rape seed oil (WDRO), olive oil (WD-OO) or soybean oil (WD-SO). These diets were given to C57BL/6J mice, and mice had higher hepatic lipid accumulation and lower insulin sensitivity when given WD-SO compared with WD-FO. Mice given WD-SO had higher hepatic...

No dramatic age-related loss of hair cells and spiral ganglion neurons in Bcl-2 over-expression mice or Bax null mice

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Ohlemiller Kevin K

2010-07-01

Full Text Available Abstract Age-related decline of neuronal function is associated with age-related structural changes. In the central nervous system, age-related decline of cognitive performance is thought to be caused by synaptic loss instead of neuronal loss. However, in the cochlea, age-related loss of hair cells and spiral ganglion neurons (SGNs is consistently observed in a variety of species, including humans. Since age-related loss of these cells is a major contributing factor to presbycusis, it is important to study possible molecular mechanisms underlying this age-related cell death. Previous studies suggested that apoptotic pathways were involved in age-related loss of hair cells and SGNs. In the present study, we examined the role of Bcl-2 gene in age-related hearing loss. In one transgenic mouse line over-expressing human Bcl-2, there were no significant differences between transgenic mice and wild type littermate controls in their hearing thresholds during aging. Histological analysis of the hair cells and SGNs showed no significant conservation of these cells in transgenic animals compared to the wild type controls during aging. These data suggest that Bcl-2 overexpression has no significant effect on age-related loss of hair cells and SGNs. We also found no delay of age-related hearing loss in mice lacking Bax gene. These findings suggest that age-related hearing loss is not through an apoptotic pathway involving key members of Bcl-2 family.

Overexpression of Adenylyl Cyclase Encoded by the Mycobacterium tuberculosis Rv2212 Gene Confers Improved Fitness, Accelerated Recovery from Dormancy and Enhanced Virulence in Mice

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Margarita O. Shleeva

2017-08-01

Full Text Available Earlier we demonstrated that the adenylyl cyclase (AC encoded by the MSMEG_4279 gene plays a key role in the resuscitation and growth of dormant Mycobacterium smegmatis and that overexpression of this gene leads to an increase in intracellular cAMP concentration and prevents the transition of M. smegmatis from active growth to dormancy in an extended stationary phase accompanied by medium acidification. We surmised that the homologous Rv2212 gene of M. tuberculosis (Mtb, the main cAMP producer, plays similar physiological roles by supporting, under these conditions, the active state and reactivation of dormant bacteria. To test this hypothesis, we established Mtb strain overexpressing Rv2212 and compared its in vitro and in vivo growth characteristics with a control strain. In vitro, the AC-overexpressing pMindRv2212 strain demonstrated faster growth in a liquid medium, prolonged capacity to form CFUs and a significant delay or even prevention of transition toward dormancy. AC-overexpressing cells exhibited easier recovery from dormancy. In vivo, AC-overexpressing bacteria demonstrated significantly higher growth rates (virulence in the lungs and spleens of infected mice compared to the control strain, and, unlike the latter, killed mice in the TB-resistant strain before month 8 of infection. Even in the absence of selecting hygromycin B, all pMindRv2212 CFUs retained the Rv2212 insert during in vivo growth, strongly suggesting that AC overexpression is beneficial for bacteria. Taken together, our results indicate that cAMP supports the maintenance of Mtb cells vitality under unfavorable conditions in vitro and their virulence in vivo.

Targeted deletion of Kif18a protects from colitis-associated colorectal (CAC) tumors in mice through impairing Akt phosphorylation

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Zhu, Houbao; Xu, Wangyang; Zhang, Hongxin; Liu, Jianbing; Xu, Haimin; Lu, Shunyuan; Dang, Suying; Kuang, Ying; Jin, Xiaolong; Wang, Zhugang

2013-01-01

Highlights: •Kif18A is up-regulated in CAC of mouse model. •Kif18a −/− mice are protected from CAC. •Tumor cells from Kif18a −/− mice undergo more apoptosis. •Kif18A deficiency induces poor Atk phosphorylation. -- Abstract: Kinesins are a superfamily of molecular motors involved in cell division or intracellular transport. They are becoming important targets for chemotherapeutic intervention of cancer due to their crucial role in mitosis. Here, we demonstrate that the kinesin-8 Kif18a is overexpressed in murine CAC and is a crucial promoter during early CAC carcinogenesis. Kif18a-deficient mice are evidently protected from AOM–DSS-induced colon carcinogenesis. Kif18A is responsible for proliferation of colonic tumor cells, while Kif18a ablation in mice promotes cell apoptosis. Mechanistically, Kif18a is responsible for induction of Akt phosphorylation, which is known to be associated with cell survival regulation. In conclusion, Kif18a is critical for colorectal carcinogenesis in the setting of inflammation by mechanisms of increased PI3K-AKT signaling. Inhibition of Kif18A activity may be useful in the prevention or chemotherapeutic intervention of CAC

Erythropoietin over-expression protects against diet-induced obesity in mice through increased fat oxidation in muscles

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Hojman, Pernille; Brolin, Camilla; Gissel, Hanne

2009-01-01

patients. Thus we applied the EPO over-expression model to investigate the metabolic effect of EPO in vivo.At 12 weeks, EPO expression resulted in a 23% weight reduction (Pobese mice; thus the mice weighed 21.9+/-0.8 g (control, normal diet,) 21.9+/-1.4 g (EPO, normal diet), 35.......3+/-3.3 g (control, high-fat diet) and 28.8+/-2.6 g (EPO, high-fat diet). Correspondingly, DXA scanning revealed that this was due to a 28% reduction in adipose tissue mass.The decrease in adipose tissue mass was accompanied by a complete normalisation of fasting insulin levels and glucose tolerance......-physiological levels has substantial metabolic effects including protection against diet-induced obesity and normalisation of glucose sensitivity associated with a shift to increased fat metabolism in the muscles....

miR-449 overexpression inhibits papillary thyroid carcinoma cell growth by targeting RET kinase-β-catenin signaling pathway.

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Li, Zongyu; Huang, Xin; Xu, Jinkai; Su, Qinghua; Zhao, Jun; Ma, Jiancang

2016-10-01

Papillary thyroid carcinoma (PTC) is the most common thyroid cancer and represent approximately 80% of all thyroid cancers. The present study is aimed to investigate the role of microRNA (miR)-449 in the progression of PTC. Our results revealed that miR-449 was underexpressed in the collected PTC specimens compared with non-cancerous PTC tissues. Overexpression of miR-449 induced a cell cycle arrest at G0/G1 phase and inhibited PTC cell growth in vitro. Further studies revealed that RET proto-oncogene (RET) is a novel miR-449 target, due to miR-449 bound directly to its 3'-untranslated region and miR-449 mimic reduced the protein expression of RET. Similar to the effects of miR-449 overexpression, RET downregulation inhibited cell growth, whereas RET overexpression reversed the inhibitive effect of miR-449 mimic. Furthermore, miR-449 overexpression inhibited the nuclear translocation of β-catenin and reduced the expression of several downstream genes, including c-Myc, cyclin D1, T cell-specific transcription factor (TCF) and lymphoid enhancer-binding factor 1 (LEF-1), and inactivated the β-catenin pathway in TPC-1 cells. Moreover, overexpression of β-catenin prevented miR-449-reduced cell cycle arrest and cell viability. In xenograft animal experiments, miR-449 overexpression effectively suppressed the tumor growth of PTC. Taken together, our research indicated that miR-449 functions as an anti-oncogene by targeting RET, and that miR-449 overexpression inhibited the growth of PTC by inactivating the β-catenin pathway. Thus, miR-449 may serve as a potential therapeutic strategy for the treatment of PTC.

Overexpression of BID in thyroids of transgenic mice increases sensitivity to iodine-induced autoimmune thyroiditis

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2014-01-01

Background BID functions as a bridge molecule between death-receptor and mitochondrial related apoptotic pathways to amplify apoptotic signaling. Our previous studies have demonstrated a substantial increase in BID expression in primary normal thyroid epithelia cells treated with inflammatory cytokines, including the combination of IFNγ and IL-1β or IFNγ and TNFα. The aim of this study was to determine whether an increase in BID expression in thyroid can induce autoimmune thyroiditis. Methods A transgenic mouse line that expresses human BID in thyroid cells was established by fusing a mouse thyroglobulin (Tg) promoter upstream of human BID (Tg-BID). We tested whether the increased expression of pro-apoptotic BID in thyroid would induce autoimmune thyroiditis, both in the presence and absence of 0.3% iodine water. Results Our data show that Tg-BID mice in a CBA/J (H-2 k) background do not spontaneously develop autoimmune thyroiditis for over a year. However, upon ingestion of iodine in the drinking water, autoimmune thyroiditis does develop in Tg-BID transgenic mice, as shown by a significant increase in anti-Tg antibody and mononuclear cell infiltration in the thyroid glands in 30% of mice tested. Serum T4 levels, however, were similar between iodine-treated Tg-BID transgenic mice and the wild type mice. Conclusions Our data demonstrate that increased thyroid expression of BID facilitates the development of autoimmune thyroiditis induced by iodine uptake. However, the overexpression of BID itself is not sufficient to initiate thyroiditis in CBA/J (H-2 k) mice. PMID:24957380

Chronic wasting disease prions are not transmissible to transgenic mice overexpressing human prion protein.

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Sandberg, Malin K; Al-Doujaily, Huda; Sigurdson, Christina J; Glatzel, Markus; O'Malley, Catherine; Powell, Caroline; Asante, Emmanuel A; Linehan, Jacqueline M; Brandner, Sebastian; Wadsworth, Jonathan D F; Collinge, John

2010-10-01

Chronic wasting disease (CWD) is a prion disease that affects free-ranging and captive cervids, including mule deer, white-tailed deer, Rocky Mountain elk and moose. CWD-infected cervids have been reported in 14 USA states, two Canadian provinces and in South Korea. The possibility of a zoonotic transmission of CWD prions via diet is of particular concern in North America where hunting of cervids is a popular sport. To investigate the potential public health risks posed by CWD prions, we have investigated whether intracerebral inoculation of brain and spinal cord from CWD-infected mule deer transmits prion infection to transgenic mice overexpressing human prion protein with methionine or valine at polymorphic residue 129. These transgenic mice have been utilized in extensive transmission studies of human and animal prion disease and are susceptible to BSE and vCJD prions, allowing comparison with CWD. Here, we show that these mice proved entirely resistant to infection with mule deer CWD prions arguing that the transmission barrier associated with this prion strain/host combination is greater than that observed with classical BSE prions. However, it is possible that CWD may be caused by multiple prion strains. Further studies will be required to evaluate the transmission properties of distinct cervid prion strains as they are characterized.

Erythropoietin over-expression protects against diet-induced obesity in mice through increased fat oxidation in muscles.

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Pernille Hojman

Full Text Available Erythropoietin can be over-expressed in skeletal muscles by gene electrotransfer, resulting in 100-fold increase in serum EPO and significant increases in haemoglobin levels. Earlier studies have suggested that EPO improves several metabolic parameters when administered to chronically ill kidney patients. Thus we applied the EPO over-expression model to investigate the metabolic effect of EPO in vivo.At 12 weeks, EPO expression resulted in a 23% weight reduction (P<0.01 in EPO transfected obese mice; thus the mice weighed 21.9+/-0.8 g (control, normal diet, 21.9+/-1.4 g (EPO, normal diet, 35.3+/-3.3 g (control, high-fat diet and 28.8+/-2.6 g (EPO, high-fat diet. Correspondingly, DXA scanning revealed that this was due to a 28% reduction in adipose tissue mass.The decrease in adipose tissue mass was accompanied by a complete normalisation of fasting insulin levels and glucose tolerance in the high-fat fed mice. EPO expression also induced a 14% increase in muscle volume and a 25% increase in vascularisation of the EPO transfected muscle. Muscle force and stamina were not affected by EPO expression. PCR array analysis revealed that genes involved in lipid metabolism, thermogenesis and inflammation were increased in muscles in response to EPO expression, while genes involved in glucose metabolism were down-regulated. In addition, muscular fat oxidation was increased 1.8-fold in both the EPO transfected and contralateral muscles.In conclusion, we have shown that EPO when expressed in supra-physiological levels has substantial metabolic effects including protection against diet-induced obesity and normalisation of glucose sensitivity associated with a shift to increased fat metabolism in the muscles.

Overexpressed connective tissue growth factor in cardiomyocytes attenuates left ventricular remodeling induced by angiotensin II perfusion.

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Zhang, Ying; Yan, Hua; Guang, Gong-Chang; Deng, Zheng-Rong

2017-01-01

To evaluate the improving effects of specifically overexpressed connective tissue growth factor (CTGF) in cardiomyocytes on mice with hypertension induced by angiotensin II (AngII) perfusion, 24 transgenic mice with cardiac-restricted overexpression of CTGF (Tg-CTGF) were divided into two equal groups that were perfused with acetic acid and AngII, respectively, for 7 days. Another 24 cage-control wild-type C57BL/6 mice (NLC) were divided and treated identically. Blood pressure was detected by caudal artery cannulation. Cardiac structural and functional changes were observed by echocardiography. Cardiac fibrosis was detected by Masson staining. After AngII perfusion, blood pressures of NLC and Tg-CTGF mice, especially those of the formers, significantly increased. Compared with NLC + AngII group, Tg-CTGF + AngII group had significantly lower left ventricular posterior wall thickness at end-diastole and left ventricular posterior wall thickness at end-systole as well as significantly higher left ventricular end-systolic diameter and left ventricular end-diastolic diameter (P tissues (P < 0.05). Tg-CTGF can protect AngII-induced cardiac remodeling of mice with hypertension by mitigating inflammatory response. CTGF may be a therapy target for hypertension-induced myocardial fibrosis, but the detailed mechanism still needs in-depth studies.

Neuropeptide Y Y1 receptor hippocampal overexpression via viral vectors is associated with modest anxiolytic-like and proconvulsant effects in mice

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Olesen, Mikkel V; Christiansen, Søren Hofman Oliveira; Gøtzsche, Casper René

2012-01-01

overexpression was found to be associated with modest anxiolytic-like effect in the open field and elevated plus maze tests, but no effect was seen on depression-like behavior using the tail suspension and forced swim tests. However, the rAAV-Y1 vector modestly aggravated kainate-induced seizures. These data...... in the hippocampus of adult mice and tested the animals in anxiety- and depression-like behavior. Hippocampal Y1 receptors have been suggested to mediate seizure-promoting effect, so the effects of rAAV-induced Y1 receptor overexpression were also tested in kainate-induced seizures. Y1 receptor transgene...

Overexpression of thioredoxin in islets transduced by a lentiviral vector prolongs graft survival in autoimmune diabetic NOD mice

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Sytwu Huey-Kang

2009-08-01

Full Text Available Abstract Pancreatic islet transplantation is considered an appropriate treatment to achieve insulin independence in type I diabetic patients. However, islet isolation and transplantation-induced oxidative stress and autoimmune-mediated destruction are still the major obstacles to the long-term survival of graft islets in this potential therapy. To protect islet grafts from inflammatory damage and prolong their survival, we transduced islets with an antioxidative gene thioredoxin (TRX using a lentiviral vector before transplantation. We hypothesized that the overexpression of TRX in islets would prolong islet graft survival when transplanted into diabetic non-obese diabetic (NOD mice. Methods Islets were isolated from NOD mice and transduced with lentivirus carrying TRX (Lt-TRX or enhanced green fluorescence protein (Lt-eGFP, respectively. Transduced islets were transplanted under the left kidney capsule of female diabetic NOD mice, and blood glucose concentration was monitored daily after transplantation. The histology of the islet graft was assessed at the end of the study. The protective effect of TRX on islets was investigated. Results The lentiviral vector effectively transduced islets without altering the glucose-stimulating insulin-secretory function of islets. Overexpression of TRX in islets reduced hydrogen peroxide-induced cytotoxicity in vitro. After transplantation into diabetic NOD mice, euglycemia was maintained for significantly longer in Lt-TRX-transduced islets than in Lt-eGFP-transduced islets; the mean graft survival was 18 vs. 6.5 days (n = 9 and 10, respectively, p Conclusion We successfully transduced the TRX gene into islets and demonstrated that these genetically modified grafts are resistant to inflammatory insult and survived longer in diabetic recipients. Our results further support the concept that the reactive oxygen species (ROS scavenger and antiapoptotic functions of TRX are critical to islet survival after

XIAP over-expression is an independent poor prognostic marker in Middle Eastern breast cancer and can be targeted to induce efficient apoptosis.

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Hussain, Azhar R; Siraj, Abdul Khalid; Ahmed, Maqbool; Bu, Rong; Pratheeshkumar, Poyil; Alrashed, Alanood M; Qadri, Zeeshan; Ajarim, Dahish; Al-Dayel, Fouad; Beg, Shaham; Al-Kuraya, Khawla S

2017-09-11

Breast cancer is the most common cancer in females and is ranked second in cancer-related deaths all over the world in women. Despite improvement in diagnosis, the survival rate of this disease has still not improved. X-linked Inhibitor of Apoptosis (XIAP) has been shown to be over-expressed in various cancers leading to poor overall survival. However, the role of XIAP in breast cancer from Middle Eastern region has not been fully explored. We examined the expression of XIAP in more than 1000 Middle Eastern breast cancer cases by immunohistochemistry. Apoptosis was measured by flow cytometry. Protein expression was determined by western blotting. Finally, in vivo studies were performed on nude mice following xenografting and treatment with inhibitors. XIAP was found to be over-expressed in 29.5% of cases and directly associated with clinical parameters such as tumor size, extra nodal extension, triple negative breast cancer and poorly differentiated breast cancer subtype. In addition, XIAP over-expression was also significantly associated with PI3-kinase pathway protein; p-AKT, proliferative marker; Ki-67 and anti-apoptotic marker; PARP. XIAP over-expression in our cohort of breast cancer was an independent poor prognostic marker in multivariate analysis. Next, we investigated inhibition of XIAP using a specific inhibitor; embelin and found that embelin treatment led to inhibition of cell viability and induction of apoptosis in breast cancer cells. Finally, breast cancer cells treated with combination of embelin and PI3-kinase inhibitor; LY294002 synergistically induced apoptosis and caused tumor growth regression in vivo. These data suggest that XIAP may be playing an important role in the pathogenesis of breast cancer and can be therapeutically targeted either alone or in combination with PI3-kinase inhibition to induce efficient apoptosis in breast cancer cells.

L-Endoglin Overexpression Increases Renal Fibrosis after Unilateral Ureteral Obstruction

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Arévalo, Miguel; Núñez-Gómez, Elena; Pérez-Roque, Lucía; Pericacho, Miguel; González-Núñez, María; Langa, Carmen; Martínez-Salgado, Carlos; Perez-Barriocanal, Fernando; Bernabeu, Carmelo; Lopez-Novoa, José M.

2014-01-01

Transforming growth factor-β (TGF-β) plays a pivotal role in renal fibrosis. Endoglin, a 180 KDa membrane glycoprotein, is a TGF-β co-receptor overexpressed in several models of chronic kidney disease, but its function in renal fibrosis remains uncertain. Two membrane isoforms generated by alternative splicing have been described, L-Endoglin (long) and S-Endoglin (short) that differ from each other in their cytoplasmic tails, being L-Endoglin the most abundant isoform. The aim of this study was to assess the effect of L-Endoglin overexpression in renal tubulo-interstitial fibrosis. For this purpose, a transgenic mouse which ubiquitously overexpresses human L-Endoglin (L-ENG+) was generated and unilateral ureteral obstruction (UUO) was performed in L-ENG+ mice and their wild type (WT) littermates. Obstructed kidneys from L-ENG+ mice showed higher amounts of type I collagen and fibronectin but similar levels of α-smooth muscle actin (α-SMA) than obstructed kidneys from WT mice. Smad1 and Smad3 phosphorylation were significantly higher in obstructed kidneys from L-ENG+ than in WT mice. Our results suggest that the higher increase of renal fibrosis observed in L-ENG+ mice is not due to a major abundance of myofibroblasts, as similar levels of α-SMA were observed in both L-ENG+ and WT mice, but to the higher collagen and fibronectin synthesis by these fibroblasts. Furthermore, in vivo L-Endoglin overexpression potentiates Smad1 and Smad3 pathways and this effect is associated with higher renal fibrosis development. PMID:25313562

Overexpression of Reelin prevents the manifestation of behavioral phenotypes related to schizophrenia and bipolar disorder.

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Teixeira, Cátia M; Martín, Eduardo D; Sahún, Ignasi; Masachs, Nuria; Pujadas, Lluís; Corvelo, André; Bosch, Carles; Rossi, Daniela; Martinez, Albert; Maldonado, Rafael; Dierssen, Mara; Soriano, Eduardo

2011-11-01

Despite the impact of schizophrenia and mood disorders, which in extreme cases can lead to death, recent decades have brought little progress in the development of new treatments. Recent studies have shown that Reelin, an extracellular protein that is critical for neuronal development, is reduced in schizophrenia and bipolar disorder patients. However, data on a causal or protective role of Reelin in psychiatric diseases is scarce. In order to study the direct influence of Reelin's levels on behavior, we subjected two mouse lines, in which Reelin levels are either reduced (Reelin heterozygous mice) or increased (Reelin overexpressing mice), to a battery of behavioral tests: open-field, black-white box, novelty-suppressed-feeding, forced-swim-test, chronic corticosterone treatment followed by forced-swim-test, cocaine sensitization and pre-pulse inhibition (PPI) deficits induced by N-methyl-D-aspartate (NMDA) antagonists. These tests were designed to model some aspects of psychiatric disorders such as schizophrenia, mood, and anxiety disorders. We found no differences between Reeler heterozygous mice and their wild-type littermates. However, Reelin overexpression in the mouse forebrain reduced the time spent floating in the forced-swim-test in mice subjected to chronic corticosterone treatment, reduced behavioral sensitization to cocaine, and reduced PPI deficits induced by a NMDA antagonist. In addition, we demonstrate that while stress increased NMDA NR2B-mediated synaptic transmission, known to be implicated in depression, Reelin overexpression significantly reduced it. Together, these results point to the Reelin signaling pathway as a relevant drug target for the treatment of a range of psychiatric disorders.

Isolated cytochrome c oxidase deficiency in G93A SOD1 mice overexpressing CCS protein.

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Son, Marjatta; Leary, Scot C; Romain, Nadine; Pierrel, Fabien; Winge, Dennis R; Haller, Ronald G; Elliott, Jeffrey L

2008-05-02

G93A SOD1 transgenic mice overexpressing CCS protein develop an accelerated disease course that is associated with enhanced mitochondrial pathology and increased mitochondrial localization of mutant SOD1. Because these results suggest an effect of mutant SOD1 on mitochondrial function, we assessed the enzymatic activities of mitochondrial respiratory chain complexes in the spinal cords of CCS/G93A SOD1 and control mice. CCS/G93A SOD1 mouse spinal cord demonstrates a 55% loss of complex IV (cytochrome c oxidase) activity compared with spinal cord from age-matched non-transgenic or G93A SOD1 mice. In contrast, CCS/G93A SOD1 spinal cord shows no reduction in the activities of complex I, II, or III. Blue native gel analysis further demonstrates a marked reduction in the levels of complex IV but not of complex I, II, III, or V in spinal cords of CCS/G93A SOD1 mice compared with non-transgenic, G93A SOD1, or CCS/WT SOD1 controls. With SDS-PAGE analysis, spinal cords from CCS/G93A SOD1 mice showed significant decreases in the levels of two structural subunits of cytochrome c oxidase, COX1 and COX5b, relative to controls. In contrast, CCS/G93A SOD1 mouse spinal cord showed no reduction in levels of selected subunits from complexes I, II, III, or V. Heme A analyses of spinal cord further support the existence of cytochrome c oxidase deficiency in CCS/G93A SOD1 mice. Collectively, these results establish that CCS/G93A SOD1 mice manifest an isolated complex IV deficiency which may underlie a substantial part of mutant SOD1-induced mitochondrial cytopathy.

Mediobasal hypothalamic overexpression of DEPTOR protects against high-fat diet-induced obesity

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Alexandre Caron

2016-02-01

Full Text Available Background/Objective: The mechanistic target of rapamycin (mTOR is a serine–threonine kinase that functions into distinct protein complexes (mTORC1 and mTORC2 that regulate energy homeostasis. DEP-domain containing mTOR-interacting protein (DEPTOR is part of these complexes and is known to dampen mTORC1 function, consequently reducing mTORC1 negative feedbacks and promoting insulin signaling and Akt/PKB activation in several models. Recently, we observed that DEPTOR is expressed in several structures of the brain including the mediobasal hypothalamus (MBH, a region that regulates energy balance. Whether DEPTOR in the MBH plays a functional role in regulating energy balance and hypothalamic insulin signaling has never been tested. Methods: We have generated a novel conditional transgenic mouse model based on the Cre-LoxP system allowing targeted overexpression of DEPTOR. Mice overexpressing DEPTOR in the MBH were subjected to a metabolic phenotyping and MBH insulin signaling was evaluated. Results: We first report that systemic (brain and periphery overexpression of DEPTOR prevents high-fat diet-induced obesity, improves glucose metabolism and protects against hepatic steatosis. These phenotypes were associated with a reduction in food intake and feed efficiency and an elevation in oxygen consumption. Strikingly, specific overexpression of DEPTOR in the MBH completely recapitulated these phenotypes. DEPTOR overexpression was associated with an increase in hypothalamic insulin signaling, as illustrated by elevated Akt/PKB activation. Conclusion: Altogether, these results support a role for MBH DEPTOR in the regulation of energy balance and metabolism. Keywords: mTOR, DEPTOR, Hypothalamus, Energy balance, Glucose metabolism

Striatal Transcriptome and Interactome Analysis of Shank3-overexpressing Mice Reveals the Connectivity between Shank3 and mTORC1 Signaling

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Yeunkum Lee

2017-06-01

Full Text Available Mania causes symptoms of hyperactivity, impulsivity, elevated mood, reduced anxiety and decreased need for sleep, which suggests that the dysfunction of the striatum, a critical component of the brain motor and reward system, can be causally associated with mania. However, detailed molecular pathophysiology underlying the striatal dysfunction in mania remains largely unknown. In this study, we aimed to identify the molecular pathways showing alterations in the striatum of SH3 and multiple ankyrin repeat domains 3 (Shank3-overexpressing transgenic (TG mice that display manic-like behaviors. The results of transcriptome analysis suggested that mammalian target of rapamycin complex 1 (mTORC1 signaling may be the primary molecular signature altered in the Shank3 TG striatum. Indeed, we found that striatal mTORC1 activity, as measured by mTOR S2448 phosphorylation, was significantly decreased in the Shank3 TG mice compared to wild-type (WT mice. To elucidate the potential underlying mechanism, we re-analyzed previously reported protein interactomes, and detected a high connectivity between Shank3 and several upstream regulators of mTORC1, such as tuberous sclerosis 1 (TSC1, TSC2 and Ras homolog enriched in striatum (Rhes, via 94 common interactors that we denominated “Shank3-mTORC1 interactome”. We noticed that, among the 94 common interactors, 11 proteins were related to actin filaments, the level of which was increased in the dorsal striatum of Shank3 TG mice. Furthermore, we could co-immunoprecipitate Shank3, Rhes and Wiskott-Aldrich syndrome protein family verprolin-homologous protein 1 (WAVE1 proteins from the striatal lysate of Shank3 TG mice. By comparing with the gene sets of psychiatric disorders, we also observed that the 94 proteins of Shank3-mTORC1 interactome were significantly associated with bipolar disorder (BD. Altogether, our results suggest a protein interaction-mediated connectivity between Shank3 and certain upstream

Targeted deletion of Kif18a protects from colitis-associated colorectal (CAC) tumors in mice through impairing Akt phosphorylation

Energy Technology Data Exchange (ETDEWEB)

Zhu, Houbao [State Key Laboratory of Medical Genomics, Research Center for Experimental Medicine, Rui-Jin Hospital and Department of Medical Genetics, E-Institutes of Shanghai Universities, Shanghai Jiao Tong University School of Medicine (SJTUSM), Shanghai 200025 (China); Xu, Wangyang [Department of Clinical Laboratories, Ninth People’s Hospital, SJTUSM, Shanghai 200011 (China); Zhang, Hongxin [State Key Laboratory of Medical Genomics, Research Center for Experimental Medicine, Rui-Jin Hospital and Department of Medical Genetics, E-Institutes of Shanghai Universities, Shanghai Jiao Tong University School of Medicine (SJTUSM), Shanghai 200025 (China); Liu, Jianbing [State Key Laboratory of Medical Genomics, Research Center for Experimental Medicine, Rui-Jin Hospital and Department of Medical Genetics, E-Institutes of Shanghai Universities, Shanghai Jiao Tong University School of Medicine (SJTUSM), Shanghai 200025 (China); Shanghai Research Center for Model Organisms, Shanghai 201203 (China); Xu, Haimin [Department of Pathology, Rui-Jin Hospital, SJTUSM, Shanghai 200025 (China); Lu, Shunyuan; Dang, Suying [State Key Laboratory of Medical Genomics, Research Center for Experimental Medicine, Rui-Jin Hospital and Department of Medical Genetics, E-Institutes of Shanghai Universities, Shanghai Jiao Tong University School of Medicine (SJTUSM), Shanghai 200025 (China); Kuang, Ying [Shanghai Research Center for Model Organisms, Shanghai 201203 (China); Jin, Xiaolong [Department of Pathology, Rui-Jin Hospital, SJTUSM, Shanghai 200025 (China); Wang, Zhugang, E-mail: zhugangw@shsmu.edu.cn [State Key Laboratory of Medical Genomics, Research Center for Experimental Medicine, Rui-Jin Hospital and Department of Medical Genetics, E-Institutes of Shanghai Universities, Shanghai Jiao Tong University School of Medicine (SJTUSM), Shanghai 200025 (China); Shanghai Research Center for Model Organisms, Shanghai 201203 (China)

2013-08-16

Highlights: •Kif18A is up-regulated in CAC of mouse model. •Kif18a{sup −/−} mice are protected from CAC. •Tumor cells from Kif18a{sup −/−} mice undergo more apoptosis. •Kif18A deficiency induces poor Atk phosphorylation. -- Abstract: Kinesins are a superfamily of molecular motors involved in cell division or intracellular transport. They are becoming important targets for chemotherapeutic intervention of cancer due to their crucial role in mitosis. Here, we demonstrate that the kinesin-8 Kif18a is overexpressed in murine CAC and is a crucial promoter during early CAC carcinogenesis. Kif18a-deficient mice are evidently protected from AOM–DSS-induced colon carcinogenesis. Kif18A is responsible for proliferation of colonic tumor cells, while Kif18a ablation in mice promotes cell apoptosis. Mechanistically, Kif18a is responsible for induction of Akt phosphorylation, which is known to be associated with cell survival regulation. In conclusion, Kif18a is critical for colorectal carcinogenesis in the setting of inflammation by mechanisms of increased PI3K-AKT signaling. Inhibition of Kif18A activity may be useful in the prevention or chemotherapeutic intervention of CAC.

In vivo examination of {sup 188}Re(I)-tricarbonyl-labeled trastuzumab to target HER2-overexpressing breast cancer

Energy Technology Data Exchange (ETDEWEB)

Chen, K.-T. [Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Lee, T.-W. [Institute of Nuclear Energy Research, Longtan 32546, Taiwan (China); Lo, Jem-Mau [Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Institute of Nuclear Engineering and Science, National Tsing Hua University, Hsinchu 30013, Taiwan (China)], E-mail: jmlo@mx.nthu.edu.tw

2009-05-15

Introduction: Trastuzumab (Herceptin), a humanized IgG1 monoclonal antibody directed against the extracellular domain of the HER2 protein, acts as an immunotherapeutic agent for HER2-overexpressing human breast cancers. Radiolabeled trastuzumab with {beta}- or {alpha} emitters can be used as radioimmunotherapeutic agent for the similar purpose but with additional radiation effect. Methods: In this study, trastuzumab was labeled with {sup 188}Re for radioimmunotherapy of HER2/neu-positive breast cancer. {sup 188}Re(I)-tricarbonyl ion, [{sup 188}Re(OH{sub 2}){sub 3}(CO){sub 3}]{sup +}, was employed as a precursor for directly labeling the monoclonal antibody with {sup 188}Re. The immunoreactivity of {sup 188}Re(I)-trastuzumab was estimated by competition receptor-binding assay using HER2/neu-overexpressive BT-474 human breast cancer cells. The localization properties of {sup 188}Re(I)-trastuzumab within both tumor and normal tissues of athymic mice bearing BT-474 human breast cancer xenografts (HER2/neu-overexpressive) and similar mice bearing MCF-7 human breast cancer xenografts (HER2/neu-low expressive) were investigated. Results: When incubated with human serum albumin and histidine at 25{sup o}C, {sup 188}Re(I)-trastuzumab was found to be stable within 24 h. The IC{sub 50} of {sup 188}Re(I)-trastuzumab was found to be 22.63{+-}4.57 nM. {sup 188}Re(I)-trastuzumab was shown to accumulate specifically in BT-474 tumor tissue in in vivo biodistribution studies. By microSPECT/CT, the image of {sup 188}Re localized BT-474 tumor was clearly visualized within 24 h. In contrast, {sup 188}Re(I)-trastuzumab uptake in HER2-low-expressing MCF-7 tumor was minimal, and the {sup 188}Re image at the localization of the tumor was dim. Conclusion: These results reveal that {sup 188}Re(I)-trastuzumab could be an appropriate radioimmunotherapeutic agent for the treatment of HER2/neu-overexpressing cancers.

Export-defective lamB protein is a target for translational control caused by ompC porin overexpression.

OpenAIRE

Click, E M; Schnaitman, C A

1989-01-01

Overexpression of OmpC protein from an inducible plasmid vector reduced the amount of the precursor form of LamB protein in LamB signal sequence mutants. The stability of the precursor form of LamB protein was not affected, indicating that the effect of OmpC overexpression was on the synthesis of the precursor rather than on degradation. These results indicate that a functional signal sequence is not required on an outer membrane protein for it to be a target for translational control.

Dual-targeting hybrid nanoparticles for the delivery of SN38 to Her2 and CD44 overexpressed human gastric cancer

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Yang, Zhe; Luo, Huiyan; Cao, Zhong; Chen, Ya; Gao, Jinbiao; Li, Yingqin; Jiang, Qing; Xu, Ruihua; Liu, Jie

2016-06-01

Gastric cancer (GC), particularly of the type with high expression of both human epidermal growth factor receptor 2 (Her2) and cluster determinant 44 (CD44), is one of the most malignant human tumors which causes a high mortality rate due to rapid tumor growth and metastasis. To develop effective therapeutic treatments, a dual-targeting hybrid nanoparticle (NP) system was designed and constructed to deliver the SN38 agent specifically to human solid gastric tumors bearing excessive Her2 and CD44. The hybrid NPs consist of a particle core made of the biodegradable polymer PLGA and a lipoid shell prepared by conjugating the AHNP peptides and n-hexadecylamine (HDA) to the carboxyl groups of hyaluronic acid (HA). Upon encapsulation of the SN38 agent in the NPs, the AHNP peptides and HA on the NP surface allow preferential delivery of the drug to gastric cancer cells (e.g., HGC27 cells) by targeting Her2 and CD44. Cellular uptake and in vivo biodistribution experiments verified the active targeting and prolonged in vivo circulation properties of the dual-targeting hybrid NPs, leading to enhanced accumulation of the drug in tumors. Furthermore, the anti-proliferation mechanism studies revealed that the inhibition of the growth and invasive activity of HGC27 cells was not only attributed to the enhanced cellular uptake of dual-targeting NPs, but also benefited from the suppression of CD44 and Her2 expression by HA and AHNP moieties. Finally, intravenous administration of the SN38-loaded dual-targeting hybrid NPs induced significant growth inhibition of HGC27 tumor xenografted in nude mice compared with a clinical antitumor agent, Irinotecan (CPT-11), and the other NP formulations. These results demonstrate that the designed dual-targeting hybrid NPs are promising for targeted anti-cancer drug delivery to treat human gastric tumors over-expressing Her2 and CD44.Gastric cancer (GC), particularly of the type with high expression of both human epidermal growth factor receptor

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

Twinkle overexpression prevents cardiac rupture after myocardial infarction by alleviating impaired mitochondrial biogenesis.

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Inoue, Takahiro; Ikeda, Masataka; Ide, Tomomi; Fujino, Takeo; Matsuo, Yuka; Arai, Shinobu; Saku, Keita; Sunagawa, Kenji

2016-09-01

Cardiac rupture is a fatal complication after myocardial infarction (MI). However, the detailed mechanism underlying cardiac rupture after MI remains to be fully elucidated. In this study, we investigated the role of mitochondrial DNA (mtDNA) and mitochondria in the pathophysiology of cardiac rupture by analyzing Twinkle helicase overexpression mice (TW mice). Twinkle overexpression increased mtDNA copy number approximately twofold and ameliorated ischemic cardiomyopathy at day 28 after MI. Notably, Twinkle overexpression markedly prevented cardiac rupture and improved post-MI survival, accompanied by the suppression of MMP-2 and MMP-9 in the MI border area at day 5 after MI when cardiac rupture frequently occurs. Additionally, these cardioprotective effects of Twinkle overexpression were abolished in transgenic mice overexpressing mutant Twinkle with an in-frame duplication of amino acids 353-365, which resulted in no increases in mtDNA copy number. Furthermore, although apoptosis and oxidative stress were induced and mitochondria were damaged in the border area, these injuries were improved in TW mice. Further analysis revealed that mitochondrial biogenesis, including mtDNA copy number, transcription, and translation, was severely impaired in the border area at day 5 In contrast, Twinkle overexpression maintained mtDNA copy number and restored the impaired transcription and translation of mtDNA in the border area. These results demonstrated that Twinkle overexpression alleviated impaired mitochondrial biogenesis in the border area through maintained mtDNA copy number and thereby prevented cardiac rupture accompanied by the reduction of apoptosis and oxidative stress, and suppression of MMP activity. Copyright © 2016 the American Physiological Society.

Early and rapid development of insulin resistance, islet dysfunction and glucose intolerance after high-fat feeding in mice overexpressing phosphodiesterase 3B

DEFF Research Database (Denmark)

Walz, Helena A; Härndahl, Linda; Wierup, Nils

2006-01-01

Inadequate islet adaptation to insulin resistance leads to glucose intolerance and type 2 diabetes. Here we investigate whether beta-cell cAMP is crucial for islet adaptation and prevention of glucose intolerance in mice. Mice with a beta-cell-specific, 2-fold overexpression of the c......AMP-degrading enzyme phosphodiesterase 3B (RIP-PDE3B/2 mice) were metabolically challenged with a high-fat diet. We found that RIP-PDE3B/2 mice early and rapidly develop glucose intolerance and insulin resistance, as compared with wild-type littermates, after 2 months of high-fat feeding. This was evident from...... did not reveal reduced insulin sensitivity in these tissues. Significant steatosis was noted in livers from high-fat-fed wild-type and RIP-PDE3B/2 mice and liver triacyl-glycerol content was 3-fold higher than in wild-type mice fed a control diet. Histochemical analysis revealed severe islet...

Reduction of age-associated pathology in old mice by overexpression of catalase in mitochondria.

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Treuting, Piper M; Linford, Nancy J; Knoblaugh, Sue E; Emond, M J; Morton, John F; Martin, George M; Rabinovitch, Peter S; Ladiges, Warren C

2008-08-01

We describe the effects of mitochondrially targeted catalase (MCAT) expression on end-of-life pathology in mice using detailed semiquantitative histopathological evaluation. We previously reported that the median and maximum life spans of MCAT mice were extended relative to those of wild-type littermates. We now report that MCAT expression is associated with reduced malignant nonhematopoietic tumor burden, reduced cardiac lesions, and a trend toward reduced systemic inflammation, with no effect on hematopoietic neoplasia or glomerulonephropathy. Combined disease burden and comorbidity are also reduced, and MCAT expression is not associated with any detrimental clinical effects. The results suggest that oxidative damage is involved in aging of C57BL/6J mice via modulation of a subset of age-associated lesions. Antioxidant interventions targeting mitochondria may therefore be a viable strategy for prevention or postponement of some age-associated diseases. The variability of the MCAT effect across tissues, however, illustrates the importance of developing semiquantitative histopathology for assessment of comorbidity in life-span studies.

Tetracycline-inducible system for regulation of skeletal muscle-specific gene expression in transgenic mice

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Grill, Mischala A.; Bales, Mark A.; Fought, Amber N.; Rosburg, Kristopher C.; Munger, Stephanie J.; Antin, Parker B.

2003-01-01

Tightly regulated control of over-expression is often necessary to study one aspect or time point of gene function and, in transgenesis, may help to avoid lethal effects and complications caused by ubiquitous over-expression. We have utilized the benefits of an optimized tet-on system and a modified muscle creatine kinase (MCK) promoter to generate a skeletal muscle-specific, doxycycline (Dox) controlled over-expression system in transgenic mice. A DNA construct was generated in which the codon optimized reverse tetracycline transactivator (rtTA) was placed under control of a skeletal muscle-specific version of the mouse MCK promoter. Transgenic mice containing this construct expressed rtTA almost exclusively in skeletal muscles. These mice were crossed to a second transgenic line containing a bi-directional promoter centered on a tet responder element driving both a luciferase reporter gene and a tagged gene of interest; in this case the calpain inhibitor calpastatin. Compound hemizygous mice showed high level, Dox dependent muscle-specific luciferase activity often exceeding 10,000-fold over non-muscle tissues of the same mouse. Western and immunocytochemical analysis demonstrated similar Dox dependent muscle-specific induction of the tagged calpastatin protein. These findings demonstrate the effectiveness and flexibility of the tet-on system to provide a tightly regulated over-expression system in adult skeletal muscle. The MCKrtTA transgenic lines can be combined with other transgenic responder lines for skeletal muscle-specific over-expression of any target gene of interest.

Efficient immunoglobulin gene disruption and targeted replacement in rabbit using zinc finger nucleases.

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Tatiana Flisikowska

Full Text Available Rabbits are widely used in biomedical research, yet techniques for their precise genetic modification are lacking. We demonstrate that zinc finger nucleases (ZFNs introduced into fertilized oocytes can inactivate a chosen gene by mutagenesis and also mediate precise homologous recombination with a DNA gene-targeting vector to achieve the first gene knockout and targeted sequence replacement in rabbits. Two ZFN pairs were designed that target the rabbit immunoglobulin M (IgM locus within exons 1 and 2. ZFN mRNAs were microinjected into pronuclear stage fertilized oocytes. Founder animals carrying distinct mutated IgM alleles were identified and bred to produce offspring. Functional knockout of the immunoglobulin heavy chain locus was confirmed by serum IgM and IgG deficiency and lack of IgM(+ and IgG(+ B lymphocytes. We then tested whether ZFN expression would enable efficient targeted sequence replacement in rabbit oocytes. ZFN mRNA was co-injected with a linear DNA vector designed to replace exon 1 of the IgM locus with ∼1.9 kb of novel sequence. Double strand break induced targeted replacement occurred in up to 17% of embryos and in 18% of fetuses analyzed. Two major goals have been achieved. First, inactivation of the endogenous IgM locus, which is an essential step for the production of therapeutic human polyclonal antibodies in the rabbit. Second, establishing efficient targeted gene manipulation and homologous recombination in a refractory animal species. ZFN mediated genetic engineering in the rabbit and other mammals opens new avenues of experimentation in immunology and many other research fields.

Catalase overexpression prevents nuclear factor erythroid 2-related factor 2 stimulation of renal angiotensinogen gene expression, hypertension, and kidney injury in diabetic mice.

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Abdo, Shaaban; Shi, Yixuan; Otoukesh, Abouzar; Ghosh, Anindya; Lo, Chao-Sheng; Chenier, Isabelle; Filep, Janos G; Ingelfinger, Julie R; Zhang, Shao Ling; Chan, John S D

2014-10-01

This study investigated the impact of catalase (Cat) overexpression in renal proximal tubule cells (RPTCs) on nuclear factor erythroid 2-related factor 2 (Nrf2) stimulation of angiotensinogen (Agt) gene expression and the development of hypertension and renal injury in diabetic Akita transgenic mice. Additionally, adult male mice were treated with the Nrf2 activator oltipraz with or without the inhibitor trigonelline. Rat RPTCs, stably transfected with plasmid containing either rat Agt or Nrf2 gene promoter, were also studied. Cat overexpression normalized systolic BP, attenuated renal injury, and inhibited RPTC Nrf2, Agt, and heme oxygenase-1 (HO-1) gene expression in Akita Cat transgenic mice compared with Akita mice. In vitro, high glucose level, hydrogen peroxide, and oltipraz stimulated Nrf2 and Agt gene expression; these changes were blocked by trigonelline, small interfering RNAs of Nrf2, antioxidants, or pharmacological inhibitors of nuclear factor-κB and p38 mitogen-activated protein kinase. The deletion of Nrf2-responsive elements in the rat Agt gene promoter abolished the stimulatory effect of oltipraz. Oltipraz administration also augmented Agt, HO-1, and Nrf2 gene expression in mouse RPTCs and was reversed by trigonelline. These data identify a novel mechanism, Nrf2-mediated stimulation of intrarenal Agt gene expression and activation of the renin-angiotensin system, by which hyperglycemia induces hypertension and renal injury in diabetic mice. © 2014 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

Multi-kilobase homozygous targeted gene replacement in human induced pluripotent stem cells.

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Byrne, Susan M; Ortiz, Luis; Mali, Prashant; Aach, John; Church, George M

2015-02-18

Sequence-specific nucleases such as TALEN and the CRISPR/Cas9 system have so far been used to disrupt, correct or insert transgenes at precise locations in mammalian genomes. We demonstrate efficient 'knock-in' targeted replacement of multi-kilobase genes in human induced pluripotent stem cells (iPSC). Using a model system replacing endogenous human genes with their mouse counterpart, we performed a comprehensive study of targeting vector design parameters for homologous recombination. A 2.7 kilobase (kb) homozygous gene replacement was achieved in up to 11% of iPSC without selection. The optimal homology arm length was around 2 kb, with homology length being especially critical on the arm not adjacent to the cut site. Homologous sequence inside the cut sites was detrimental to targeting efficiency, consistent with a synthesis-dependent strand annealing (SDSA) mechanism. Using two nuclease sites, we observed a high degree of gene excisions and inversions, which sometimes occurred more frequently than indel mutations. While homozygous deletions of 86 kb were achieved with up to 8% frequency, deletion frequencies were not solely a function of nuclease activity and deletion size. Our results analyzing the optimal parameters for targeting vector design will inform future gene targeting efforts involving multi-kilobase gene segments, particularly in human iPSC. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

Regulation, overexpression, and target gene identification of Potato Homeobox 15 (POTH15) – a class-I KNOX gene in potato

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Mahajan, Ameya S.; Kondhare, Kirtikumar R.; Rajabhoj, Mohit P.; Kumar, Amit; Ghate, Tejashree; Ravindran, Nevedha; Habib, Farhat; Siddappa, Sundaresha; Banerjee, Anjan K.

2016-01-01

Potato Homeobox 15 (POTH15) is a KNOX-I (Knotted1-like homeobox) family gene in potato that is orthologous to Shoot Meristemless (STM) in Arabidopsis. Despite numerous reports on KNOX genes from different species, studies in potato are limited. Here, we describe photoperiodic regulation of POTH15, its overexpression phenotype, and identification of its potential targets in potato (Solanum tuberosum ssp. andigena). qRT-PCR analysis showed a higher abundance of POTH15 mRNA in shoot tips and stolons under tuber-inducing short-day conditions. POTH15 promoter activity was detected in apical and axillary meristems, stolon tips, tuber eyes, and meristems of tuber sprouts, indicating its role in meristem maintenance and leaf development. POTH15 overexpression altered multiple morphological traits including leaf and stem development, leaflet number, and number of nodes and branches. In particular, the rachis of the leaf was completely reduced and leaves appeared as a bouquet of leaflets. Comparative transcriptomic analysis of 35S::GUS and two POTH15 overexpression lines identified more than 6000 differentially expressed genes, including 2014 common genes between the two overexpression lines. Functional analysis of these genes revealed their involvement in responses to hormones, biotic/abiotic stresses, transcription regulation, and signal transduction. qRT-PCR of selected candidate target genes validated their differential expression in both overexpression lines. Out of 200 randomly chosen POTH15 targets, 173 were found to have at least one tandem TGAC core motif, characteristic of KNOX interaction, within 3.0kb in the upstream sequence of the transcription start site. Overall, this study provides insights to the role of POTH15 in controlling diverse developmental processes in potato. PMID:27217546

Targeted deletion of C1q/TNF-related protein 9 increases food intake, decreases insulin sensitivity, and promotes hepatic steatosis in mice.

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Wei, Zhikui; Lei, Xia; Petersen, Pia S; Aja, Susan; Wong, G William

2014-04-01

Transgenic overexpression of CTRP9, a secreted hormone downregulated in obesity, confers striking protection against diet-induced obesity and type 2 diabetes. However, the physiological relevance of this adiponectin-related plasma protein remains undefined. Here, we used gene targeting to establish the metabolic function of CTRP9 in a physiological context. Mice lacking CTRP9 were obese and gained significantly more body weight when fed standard laboratory chow. Increased food intake, due in part to upregulated expression of hypothalamic orexigenic neuropeptides, contributed to greater adiposity in CTRP9 knockout mice. Although the frequency of food intake remained unchanged, CTRP9 knockout mice increased caloric intake by increasing meal size and decreasing satiety ratios. The absence of CTRP9 also resulted in peripheral tissue insulin resistance, leading to increased fasting insulin levels, impaired hepatic insulin signaling, and reduced insulin tolerance. Increased expression of lipogenic genes, combined with enhanced caloric intake, contributed to hepatic steatosis in CTRP9 knockout mice. Loss of CTRP9 also resulted in reduced skeletal muscle AMPK activation and mitochondrial content. Together, these results provide the genetic evidence for a physiological role of CTRP9 in controlling energy balance via central and peripheral mechanisms.

Lipid-Based Nanovectors for Targeting of CD44-Overexpressing Tumor Cells

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Silvia Arpicco

2013-01-01

Full Text Available Hyaluronic acid (HA is a naturally occurring glycosaminoglycan that exists in living systems, and it is a major component of the extracellular matrix. The hyaluronic acid receptor CD44 is found at low levels on the surface of epithelial, haematopoietic, and neuronal cells and is overexpressed in many cancer cells particularly in tumour initiating cells. HA has been therefore used as ligand attached to HA-lipid-based nanovectors for the active targeting of small or large active molecules for the treatment of cancer. This paper describes the different approaches employed for the preparation, characterization, and evaluation of these potent delivery systems.

Spontaneous autoimmunity in 129 and C57BL/6 mice-implications for autoimmunity described in gene-targeted mice.

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Anne E Bygrave

2004-08-01

Full Text Available Systemic lupus erythematosus (SLE is a multisystem autoimmune disorder in which complex genetic factors play an important role. Several strains of gene-targeted mice have been reported to develop SLE, implicating the null genes in the causation of disease. However, hybrid strains between 129 and C57BL/6 mice, widely used in the generation of gene-targeted mice, develop spontaneous autoimmunity. Furthermore, the genetic background markedly influences the autoimmune phenotype of SLE in gene-targeted mice. This suggests an important role in the expression of autoimmunity of as-yet-uncharacterised background genes originating from these parental mouse strains. Using genome-wide linkage analysis, we identified several susceptibility loci, derived from 129 and C57BL/6 mice, mapped in the lupus-prone hybrid (129 x C57BL/6 model. By creating a C57BL/6 congenic strain carrying a 129-derived Chromosome 1 segment, we found that this 129 interval was sufficient to mediate the loss of tolerance to nuclear antigens, which had previously been attributed to a disrupted gene. These results demonstrate important epistatic modifiers of autoimmunity in 129 and C57BL/6 mouse strains, widely used in gene targeting. These background gene influences may account for some, or even all, of the autoimmune traits described in some gene-targeted models of SLE.

New Targets for End-Stage Chronic Kidney Disease Therapy

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Prakoura Niki

2015-05-01

Full Text Available Severe forms of chronic kidney disease can lead to a critical, end-stage condition, requiring renal replacement therapy, which may involve a form of dialysis or renal transplantation. Identification and characterization of novel markers and/or targets of therapy that could be applied in these critically ill patients remains the focus of the current research in the field of critical care medicine and has been the objective of our studies for some years past. To this end, we used models of renal vascular disease, Ang II, L-NAME or mice overexpressing renin, treated with AT1 antagonists at different stages of progression, to create cohorts of animals during progression, reversal or escape from therapy. Transcriptomic analysis and comparisons were performed and genes were selected according to the following criteria: a not previously described in the kidney, b highly upregulated during progression and returning to the normal levels during reversal, and c producing proteins that are either circulating or membrane receptors.

Overexpression of the E2F target gene CENPI promotes chromosome instability and predicts poor prognosis in estrogen receptor-positive breast cancer.

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Thangavelu, Pulari U; Lin, Cheng-Yu; Vaidyanathan, Srividya; Nguyen, Thu H M; Dray, Eloise; Duijf, Pascal H G

2017-09-22

During cell division, chromosome segregation is facilitated by the mitotic checkpoint, or spindle assembly checkpoint (SAC), which ensures correct kinetochore-microtubule attachments and prevents premature sister-chromatid separation. It is well established that misexpression of SAC components on the outer kinetochores promotes chromosome instability (CIN) and tumorigenesis. Here, we study the expression of CENP-I, a key component of the HIKM complex at the inner kinetochores, in breast cancer, including ductal, lobular, medullary and male breast carcinomas. CENPI mRNA and protein levels are significantly elevated in estrogen receptor-positive (ER+) but not in estrogen receptor-negative (ER-) breast carcinoma. Well-established prognostic tests indicate that CENPI overexpression constitutes a powerful independent marker for poor patient prognosis and survival in ER+ breast cancer. We further demonstrate that CENPI is an E2F target gene. Consistently, it is overexpressed in RB1 -deficient breast cancers. However, CENP-I overexpression is not purely due to cell cycle-associated expression. In ER+ breast cancer cells, CENP-I overexpression promotes CIN, especially chromosome gains. In addition, in ER+ breast carcinomas the degree of CENPI overexpression is proportional to the level of aneuploidy and CENPI overexpression is one of the strongest markers for CIN identified to date. Our results indicate that overexpression of the inner kinetochore protein CENP-I promotes CIN and forecasts poor prognosis for ER+ breast cancer patients. These observations provide novel mechanistic insights and have important implications for breast cancer diagnostics and potentially therapeutic targeting.

Targeted radiotherapy with 177 Lu-DOTA-TATE in athymic mice with induced pancreatic malignant tumours

International Nuclear Information System (INIS)

Murphy, M. A de; Pedraza L, M.; Rodriguez C, J.; Ferro F, G.; Murphy S, E.

2006-01-01

Malignant pancreas tumours induced in athymic mice are a good model for targeted radiotherapy. The objective of this research was to estimate pancreatic tumour absorbed radiation doses and to evaluate 177 Lu-DOTA-TATE as a therapeutic radiopharmaceutical that could be used in humans. AR42J murine pancreas cancer cells, which over-express somatostatin receptors, were injected in athymic mice and 20 days later the mean tumour size was 3.08 square cm (n=3). A mean of 86.3 MBq 177 Lu-DOTA-TATE, was injected in a tail vein and 19 days after therapy the size of the tumours was 0.81 square cm. There was a partial relapse and after 16 days, when sacrificed, the mean tumour size was 8.28 cubic cm. An epithelial and sarcoma mixed tumour in the kidney of one treated mouse was found. The tumour of the control mouse was 8.61 cubic cm when sacrificed 14 days after tumour induction. Radiotherapy estimates to the tumours was 35.9-39.7 Gy and the tumours might have been completely reduced with a second therapy dose. These preliminary studies justify further therapeutic and dosimetry estimations to ensure that Lu- 177 -DOTA-TATE will act as expected in man, considering kidney radiation. (Author)

PTK2B/Pyk2 overexpression improves a mouse model of Alzheimer's disease

KAUST Repository

Giralt, Albert; de Pins, Benoî t; Cifuentes-Dí az, Carmen; Ló pez-Molina, Laura; Farah, Amel Thamila; Tible, Marion; Deramecourt, Vincent; Arold, Stefan T.; Giné s, Silvia; Hugon, Jacques; Girault, Jean-Antoine

2018-01-01

Pyk2 is a Ca2+-activated non-receptor tyrosine kinase enriched in forebrain neurons and involved in synaptic regulation. Human genetic studies associated PTK2B, the gene coding Pyk2, with risk for Alzheimer's disease (AD). We previously showed that Pyk2 is important for hippocampal function, plasticity, and spine structure. However, its potential role in AD is unknown. To address this question we used human brain samples and 5XFAD mice, an amyloid mouse model of AD expressing mutated human amyloid precursor protein and presenilin1. In the hippocampus of 5XFAD mice and in human AD patients' cortex and hippocampus, Pyk2 total levels were normal. However, Pyk2 Tyr-402 phosphorylation levels, reflecting its autophosphorylation-dependent activity, were reduced in 5XFAD mice at 8 months of age but at 3 months. We crossed these mice with Pyk2−/− mice to generate 5XFAD animals devoid of Pyk2. At 8 months the phenotype of 5XFAD x Pyk2−/− double mutant mice was not different from that of 5XFAD. In contrast, overexpression of Pyk2 in the hippocampus of 5XFAD mice, using adeno-associated virus, rescued autophosphorylated Pyk2 levels and improved synaptic markers and performance in several behavioral tasks. Both Pyk2−/− and 5XFAD mice showed an increase of potentially neurotoxic Src cleavage product, which was rescued by Pyk2 overexpression. Manipulating Pyk2 levels had only minor effects on Aβ plaques, which were slightly decreased in hippocampus CA3 region of double mutant mice and increased following overexpression. Our results show that Pyk2 is not essential for the pathogenic effect of human amyloidogenic mutations in the 5XFAD mouse model. However, the slight decrease in plaque number observed in these mice in the absence of Pyk2 and their increase following Pyk2 overexpression suggest a contribution of this kinase in plaque formation. Importantly, a decreased function of Pyk2 was observed in 5XFAD mice, indicated by its decreased autophosphorylation

PTK2B/Pyk2 overexpression improves a mouse model of Alzheimer's disease

KAUST Repository

Giralt, Albert

2018-05-24

Pyk2 is a Ca2+-activated non-receptor tyrosine kinase enriched in forebrain neurons and involved in synaptic regulation. Human genetic studies associated PTK2B, the gene coding Pyk2, with risk for Alzheimer\\'s disease (AD). We previously showed that Pyk2 is important for hippocampal function, plasticity, and spine structure. However, its potential role in AD is unknown. To address this question we used human brain samples and 5XFAD mice, an amyloid mouse model of AD expressing mutated human amyloid precursor protein and presenilin1. In the hippocampus of 5XFAD mice and in human AD patients\\' cortex and hippocampus, Pyk2 total levels were normal. However, Pyk2 Tyr-402 phosphorylation levels, reflecting its autophosphorylation-dependent activity, were reduced in 5XFAD mice at 8 months of age but at 3 months. We crossed these mice with Pyk2−/− mice to generate 5XFAD animals devoid of Pyk2. At 8 months the phenotype of 5XFAD x Pyk2−/− double mutant mice was not different from that of 5XFAD. In contrast, overexpression of Pyk2 in the hippocampus of 5XFAD mice, using adeno-associated virus, rescued autophosphorylated Pyk2 levels and improved synaptic markers and performance in several behavioral tasks. Both Pyk2−/− and 5XFAD mice showed an increase of potentially neurotoxic Src cleavage product, which was rescued by Pyk2 overexpression. Manipulating Pyk2 levels had only minor effects on Aβ plaques, which were slightly decreased in hippocampus CA3 region of double mutant mice and increased following overexpression. Our results show that Pyk2 is not essential for the pathogenic effect of human amyloidogenic mutations in the 5XFAD mouse model. However, the slight decrease in plaque number observed in these mice in the absence of Pyk2 and their increase following Pyk2 overexpression suggest a contribution of this kinase in plaque formation. Importantly, a decreased function of Pyk2 was observed in 5XFAD mice, indicated by its decreased

Glucagon-like peptide-1 receptor overexpression in cancer and its impact on clinical applications

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Meike eKörner

2012-12-01

Full Text Available Peptide hormones of the glucagon-like peptide (GLP family play an increasing clinical role, such as GLP-1 in diabetes therapy. Moreover, GLP receptors are over-expressed in various human tumor types and therefore represent molecular targets for important clinical applications. In particular, virtually all benign insulinomas highly over-express GLP-1 receptors (GLP-1R. Targeting GLP-1R with the stable GLP-1 analogs 111In-DOTA/ DPTA-exendin-4 offers a new approach to successfully localize these small tumors. This non-invasive technique has the potential to replace the invasive localization of insulinomas by selective arterial stimulation and venous sampling. Malignant insulinomas, in contrast to their benign counterparts, express GLP-1R in only one third of the cases, while they more often express the somatostatin type 2 receptors. Importantly, one of the two receptors appears to be always expressed in malignant insulinomas. The GLP-1R overexpression in selected cancers is worth to be kept in mind with regard to the increasing use of GLP-1 analogs for diabetes therapy. While the functional role of GLP-1R in neoplasia is not known yet, it may be safe to monitore patients undergoing GLP-1 therapy carefully.

Gene-Targeted Mice with the Human Troponin T R141W Mutation Develop Dilated Cardiomyopathy with Calcium Desensitization.

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Mohun Ramratnam

Full Text Available Most studies of the mechanisms leading to hereditary dilated cardiomyopathy (DCM have been performed in reconstituted in vitro systems. Genetically engineered murine models offer the opportunity to dissect these mechanisms in vivo. We generated a gene-targeted knock-in murine model of the autosomal dominant Arg141Trp (R141W mutation in Tnnt2, which was first described in a human family with DCM. Mice heterozygous for the mutation (Tnnt2R141W/+ recapitulated the human phenotype, developing left ventricular dilation and reduced contractility. There was a gene dosage effect, so that the phenotype in Tnnt2R141W/+mice was attenuated by transgenic overexpression of wildtype Tnnt2 mRNA transcript. Male mice exhibited poorer survival than females. Biomechanical studies on skinned fibers from Tnnt2R141W/+ hearts showed a significant decrease in pCa50 (-log[Ca2+] required for generation of 50% of maximal force relative to wildtype hearts, indicating Ca2+ desensitization. Optical mapping studies of Langendorff-perfused Tnnt2R141W/+ hearts showed marked increases in diastolic and peak systolic intracellular Ca2+ ([Ca2+]i, and prolonged systolic rise and diastolic fall of [Ca2+]i. Perfused Tnnt2R141W/+ hearts had slower intrinsic rates in sinus rhythm and reduced peak heart rates in response to isoproterenol. Tnnt2R141W/+ hearts exhibited a reduction in phosphorylated phospholamban relative to wildtype mice. However, crossing Tnnt2R141W/+ mice with phospholamban knockout (Pln-/- mice, which exhibit increased Ca2+ transients and contractility, had no effect on the DCM phenotype. We conclude that the Tnnt2 R141W mutation causes a Ca2+ desensitization and mice adapt by increasing Ca2+-transient amplitudes, which impairs Ca2+ handling dynamics, metabolism and responses to β-adrenergic activation.

Sevoflurane Inhalation Accelerates the Long-Term Memory Consolidation via Small GTPase Overexpression in the Hippocampus of Mice in Adolescence.

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Nakamura, Emi; Kinoshita, Hiroyuki; Feng, Guo-Gang; Hayashi, Hisaki; Satomoto, Maiko; Sato, Motohiko; Fujiwara, Yoshihiro

2016-01-01

Sevoflurane exposure impairs the long-term memory in neonates. Whether the exposure to animals in adolescence affects the memory, however, has been unclear. A small hydrolase enzyme of guanosine triphosphate (GTPase) rac1 plays a role in the F-actin dynamics related to the synaptic plasticity, as well as superoxide production via reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation. The current study was designed to examine whether sevoflurane exposure to mice in early adolescence modifies the long-term learning ability concomitantly with the changes in F-actin constitution as well as superoxide production in the hippocampus according to the levels of rac1 protein expression. Four-week-old mice were subjected to the evaluation of long-term learning ability for three days. On day one, each mouse was allowed to enter a dark chamber for five min to acclimatization. On day two, the procedure was repeated with the addition of an electric shock as soon as a mouse entered the dark chamber. All mice subsequently inhaled 2 L/min air with (Sevoflurane group) and without (Control group) 2.5% sevoflurane for three hours. On day three, each mouse was placed on the platform and retention time, which is the latency to enter the dark chamber, was examined. The brain removed after the behavior test, was used for analyses of immunofluorescence, Western immunoblotting and intracellular levels of superoxide. Sevoflurane exposure significantly prolonged retention time, indicating the enhanced long-term memory. Sevoflurane inhalation augmented F-actin constitution coexisting with the rac1 protein overexpression in the hippocampus whereas it did not alter the levels of superoxide. Sevoflurane exposure to 4-week-old mice accelerates the long-term memory concomitantly with the enhanced F-actin constitution coexisting with the small GTPase rac1 overexpression in the hippocampus. These results suggest that sevoflurane inhalation may amplify long-term memory

Persistent Coxiella burnetii infection in mice overexpressing IL-10: an efficient model for chronic Q fever pathogenesis.

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Soraya Meghari

2008-02-01

Full Text Available Interleukin (IL-10 increases host susceptibility to microorganisms and is involved in intracellular persistence of bacterial pathogens. IL-10 is associated with chronic Q fever, an infectious disease due to the intracellular bacterium Coxiella burnetii. Nevertheless, accurate animal models of chronic C. burnetii infection are lacking. Transgenic mice constitutively expressing IL-10 in macrophages were infected with C. burnetti by intraperitoneal and intratracheal routes and infection was analyzed through real-time PCR and antibody production. Transgenic mice exhibited sustained tissue infection and strong antibody response in contrast to wild-type mice; thus, bacterial persistence was IL-10-dependent as in chronic Q fever. The number of granulomas was low in spleen and liver of transgenic mice infected through the intraperitoneal route, as in patients with chronic Q fever. Macrophages from transgenic mice were unable to kill C. burnetii. C. burnetii-stimulated macrophages were characterized by non-microbicidal transcriptional program consisting of increased expression of arginase-1, mannose receptor, and Ym1/2, in contrast to wild-type macrophages in which expression of inducible NO synthase and inflammatory cytokines was increased. In vivo results emphasized macrophage data. In spleen and liver of transgenic mice infected with C. burnetii by the intraperitoneal route, the expression of arginase-1 was increased while microbicidal pathway consisting of IL-12p40, IL-23p19, and inducible NO synthase was depressed. The overexpression of IL-10 in macrophages prevents anti-infectious competence of host, including the ability to mount granulomatous response and microbicidal pathway in tissues. To our knowledge, this is the first efficient model for chronic Q fever pathogenesis.

Global Overexpression of ET-1 Decreases Blood Pressure - A Systematic Review and Meta-Analysis of ET-1 Transgenic Mice.

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Lu, Yong Ping; Tsuprykov, Oleg; Vignon-Zellweger, Nicolas; Heiden, Susi; Hocher, Berthold

2016-01-01

ET-1 has independent effects on blood pressure regulation in vivo, it is involved in tubular water and salt excretion, promotes constriction of smooth muscle cells, modulates sympathetic nerve activity, and activates the liberation of nitric oxide. To determine the net effect of these partially counteracting mechanisms on blood pressure, a systematic meta-analysis was performed. Based on the principles of Cochrane systematic reviews, we searched in major literature databases - MEDLINE (PubMed), Embase, Google Scholar, and the China Biological Medicine Database (CBM-disc) - for articles relevant to the topic of the blood pressure phenotype of endothelin-1 transgenic (ET-1+/+) mice from January 1, 1988 to March 31, 2016. Review Manager Version 5.0 (Rev-Man 5.0) software was applied for statistical analysis. In total thirteen studies reported blood pressure data. The meta-analysis of blood pressure data showed that homozygous ET-1 transgenic mice (ET-1+/+ mice) had a significantly lower blood pressure as compared to WT mice (mean difference: -2.57 mmHg, 95% CI: -4.98∼ -0.16, P = 0.04), with minimal heterogeneity (P = 0.86). A subgroup analysis of mice older than 6 months revealed that the blood pressure difference between ET-1+/+ mice and WT mice was even more pronounced (mean difference: -6.19 mmHg, 95% CI: -10.76∼ -1.62, P = 0.008), with minimal heterogeneity (P = 0.91). This meta-analysis provides robust evidence that global ET-1 overexpression in mice lowers blood pressure in an age-dependent manner. Older ET-1+/+ mice have a somewhat more pronounced reduction of blood pressure. © 2016 The Author(s) Published by S. Karger AG, Basel.

Targeted radiotherapy with {sup 177} Lu-DOTA-TATE in athymic mice with induced pancreatic malignant tumours

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Murphy, M. A de; Pedraza L, M. [Department of Nuclear Medicine, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Mexico D.F. (Mexico); Rodriguez C, J. [Faculty of Medicine, UAEM, Toluca, Estado de Mexico (Mexico); Ferro F, G. [ININ, 52045 Estado de Mexico (Mexico); Murphy S, E. [Hospital Santelena, Mexico D.F. (Mexico)

2006-07-01

Malignant pancreas tumours induced in athymic mice are a good model for targeted radiotherapy. The objective of this research was to estimate pancreatic tumour absorbed radiation doses and to evaluate {sup 177}Lu-DOTA-TATE as a therapeutic radiopharmaceutical that could be used in humans. AR42J murine pancreas cancer cells, which over-express somatostatin receptors, were injected in athymic mice and 20 days later the mean tumour size was 3.08 square cm (n=3). A mean of 86.3 MBq {sup 177}Lu-DOTA-TATE, was injected in a tail vein and 19 days after therapy the size of the tumours was 0.81 square cm. There was a partial relapse and after 16 days, when sacrificed, the mean tumour size was 8.28 cubic cm. An epithelial and sarcoma mixed tumour in the kidney of one treated mouse was found. The tumour of the control mouse was 8.61 cubic cm when sacrificed 14 days after tumour induction. Radiotherapy estimates to the tumours was 35.9-39.7 Gy and the tumours might have been completely reduced with a second therapy dose. These preliminary studies justify further therapeutic and dosimetry estimations to ensure that Lu-{sup 177}-DOTA-TATE will act as expected in man, considering kidney radiation. (Author)

Redox susceptibility of SOD1 mutants is associated with the differential response to CCS over-expression in vivo.

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Son, Marjatta; Fu, Qiao; Puttaparthi, Krishna; Matthews, Christina M; Elliott, Jeffrey L

2009-04-01

Over-expression of CCS in G93A SOD1 mice accelerates neurological disease and enhances mitochondrial pathology. We studied the effect of CCS over-expression in transgenic mice expressing G37R, G86R or L126Z SOD1 mutations in order to understand factors which influence mitochondrial dysfunction. Over-expression of CCS markedly decreased survival and produced mitochondrial vacuolation in G37R SOD1 mice but not in G86R or L126Z SOD1 mice. Moreover, CCS/G37R SOD1 spinal cord showed specific reductions in mitochondrial complex IV subunits consistent with an isolated COX deficiency, while no such reductions were detected in CCS/G86R or CCS/L126Z SOD1 mice. CCS over-expression increased the ratio of reduced to oxidized SOD1 monomers in the spinal cords of G37R SOD1 as well as G93A SOD1 mice, but did not influence the redox state of G86R or L126Z SOD1 monomers. The effects of CCS on disease are SOD1 mutation dependent and correlate with SOD1 redox susceptibility.

Dual peptide-mediated targeted delivery of bioactive siRNAs to oral cancer cells in vivo.

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Alexander-Bryant, Angela A; Zhang, Haiwen; Attaway, Christopher C; Pugh, William; Eggart, Laurence; Sansevere, Robert M; Andino, Lourdes M; Dinh, Lu; Cantini, Liliana P; Jakymiw, Andrew

2017-09-01

Despite significant advances in cancer treatment, the prognosis for oral cancer remains poor in comparison to other cancer types, including breast, skin, and prostate. As a result, more effective therapeutic modalities are needed for the treatment of oral cancer. Consequently, in the present study, we examined the feasibility of using a dual peptide carrier approach, combining an epidermal growth factor receptor (EGFR)-targeting peptide with an endosome-disruptive peptide, to mediate targeted delivery of small interfering RNAs (siRNAs) into EGFR-overexpressing oral cancer cells and induce silencing of the targeted oncogene, cancerous inhibitor of protein phosphatase 2A (CIP2A). Fluorescence microscopy, real-time PCR, Western blot analysis, and in vivo bioimaging of mice containing orthotopic xenograft tumors were used to examine the ability of the dual peptide carrier to mediate specific delivery of bioactive siRNAs into EGFR-overexpressing oral cancer cells/tissues. Co-complexation of the EGFR-targeting peptide, GE11R9, with the endosome-disruptive 599 peptide facilitated the specific uptake of siRNAs into oral cancer cells overexpressing EGFR in vitro with optimal gene silencing observed at a 60:30:1 (GE11R9:599:siRNA) molar ratio. Furthermore, when administered systemically to mice bearing xenograft oral tumors, this dual peptide complex mediated increased targeted delivery of siRNAs into tumor tissues in comparison to the 599 peptide alone and significantly enhanced CIP2A silencing. Herein we provide the first report demonstrating the clinical potential of a dual peptide strategy for siRNA-based therapeutics by synergistically mediating the effective targeting and delivery of bioactive siRNAs into EGFR-overexpressing oral cancer cells. Copyright © 2017 Elsevier Ltd. All rights reserved.

Vascular endothelial overexpression of human CYP2J2 (Tie2-CYP2J2 Tr) modulates cardiac oxylipin profiles and enhances coronary reactive hyperemia in mice

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Hanif, Ahmad; Edin, Matthew L.; Zeldin, Darryl C.; Morisseau, Christophe; Falck, John R.

2017-01-01

Arachidonic acid is metabolized to epoxyeicosatrienoic acids (EETs) by cytochrome (CYP) P450 epoxygenases, and to ω-terminal hydroxyeicosatetraenoic acids (HETEs) by ω-hydroxylases. EETs and HETEs often have opposite biologic effects; EETs are vasodilatory and protect against ischemia/reperfusion injury, while ω-terminal HETEs are vasoconstrictive and cause vascular dysfunction. Other oxylipins, such as epoxyoctadecaenoic acids (EpOMEs), hydroxyoctadecadienoic acids (HODEs), and prostanoids also have varied vascular effects. Post-ischemic vasodilation in the heart, known as coronary reactive hyperemia (CRH), protects against potential damage to the heart muscle caused by ischemia. The relationship among CRH response to ischemia, in mice with altered levels of CYP2J epoxygenases has not yet been investigated. Therefore, we evaluated the effect of endothelial overexpression of the human cytochrome P450 epoxygenase CYP2J2 in mice (Tie2-CYP2J2 Tr) on oxylipin profiles and CRH. Additionally, we evaluated the effect of pharmacologic inhibition of CYP-epoxygenases and inhibition of ω-hydroxylases on CRH. We hypothesized that CRH would be enhanced in isolated mouse hearts with vascular endothelial overexpression of human CYP2J2 through modulation of oxylipin profiles. Similarly, we expected that inhibition of CYP-epoxygenases would reduce CRH, whereas inhibition of ω-hydroxylases would enhance CRH. Compared to WT mice, Tie2-CYP2J2 Tr mice had enhanced CRH, including repayment volume, repayment duration, and repayment/debt ratio (P iso-PGF2α (P < 0.05). Inhibition of CYP epoxygenases with MS-PPOH attenuated CRH (P < 0.05). Ischemia caused a decrease in mid-chain HETEs (5-, 11-, 12-, 15-HETEs P < 0.05) and HODEs (P < 0.05). These data demonstrate that vascular endothelial overexpression of CYP2J2, through changing the oxylipin profiles, enhances CRH. Inhibition of CYP epoxygenases decreases CRH, whereas inhibition of ω-hydroxylases enhances CRH. PMID:28328948

Overexpression of transmembrane protein 168 in the mouse nucleus accumbens induces anxiety and sensorimotor gating deficit.

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Kequan Fu

Full Text Available Transmembrane protein 168 (TMEM168 comprises 697 amino acid residues, including some putative transmembrane domains. It is reported that TMEM168 controls methamphetamine (METH dependence in the nucleus accumbens (NAc of mice. Moreover, a strong link between METH dependence-induced adaptive changes in the brain and mood disorders has been evaluated. In the present study, we investigated the effects of accumbal TMEM168 in a battery of behavioral paradigms. The adeno-associated virus (AAV Tmem168 vector was injected into the NAc of C57BL/6J mice (NAc-TMEM mice. Subsequently, the accumbal TMEM168 mRNA was increased approximately by seven-fold when compared with the NAc-Mock mice (controls. The NAc-TMEM mice reported no change in the locomotor activity, cognitive ability, social interaction, and depression-like behaviors; however, TMEM168 overexpression enhanced anxiety in the elevated-plus maze and light/dark box test. The increased anxiety was reversed by pretreatment with the antianxiety drug diazepam (0.3 mg/kg i.p.. Moreover, the NAc-TMEM mice exhibited decreased prepulse inhibition (PPI in the startle response test, and the induced schizophrenia-like behavior was reversed by pretreatment with the antipsychotic drug risperidone (0.01 mg/kg i.p.. Furthermore, accumbal TMEM168 overexpression decreased the basal levels of extracellular GABA in the NAc and the high K+ (100 mM-stimulated GABA elevation; however, the total contents of GABA in the NAc remained unaffected. These results suggest that the TMEM168-regulated GABAergic neuronal system in the NAc might become a novel target while studying the etiology of anxiety and sensorimotor gating deficits.

Overexpression of heterogeneous nuclear ribonucleoprotein F stimulates renal Ace-2 gene expression and prevents TGF-β1-induced kidney injury in a mouse model of diabetes.

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Lo, Chao-Sheng; Shi, Yixuan; Chang, Shiao-Ying; Abdo, Shaaban; Chenier, Isabelle; Filep, Janos G; Ingelfinger, Julie R; Zhang, Shao-Ling; Chan, John S D

2015-10-01

We investigated whether heterogeneous nuclear ribonucleoprotein F (hnRNP F) stimulates renal ACE-2 expression and prevents TGF-β1 signalling, TGF-β1 inhibition of Ace-2 gene expression and induction of tubulo-fibrosis in an Akita mouse model of type 1 diabetes. Adult male Akita transgenic (Tg) mice overexpressing specifically hnRNP F in their renal proximal tubular cells (RPTCs) were studied. Non-Akita littermates and Akita mice served as controls. Immortalised rat RPTCs stably transfected with plasmid containing either rat Hnrnpf cDNA or rat Ace-2 gene promoter were also studied. Overexpression of hnRNP F attenuated systemic hypertension, glomerular filtration rate, albumin/creatinine ratio, urinary angiotensinogen (AGT) and angiotensin (Ang) II levels, renal fibrosis and profibrotic gene (Agt, Tgf-β1, TGF-β receptor II [Tgf-βrII]) expression, stimulated anti-profibrotic gene (Ace-2 and Ang 1-7 receptor [MasR]) expression, and normalised urinary Ang 1-7 level in Akita Hnrnpf-Tg mice as compared with Akita mice. In vitro, hnRNP F overexpression stimulated Ace-2 gene promoter activity, mRNA and protein expression, and attenuated Agt, Tgf-β1 and Tgf-βrII gene expression. Furthermore, hnRNP F overexpression prevented TGF-β1 signalling and TGF-β1 inhibition of Ace-2 gene expression. These data demonstrate that hnRNP F stimulates Ace-2 gene transcription, prevents TGF-β1 inhibition of Ace-2 gene transcription and induction of kidney injury in diabetes. HnRNP F may be a potential target for treating hypertension and renal fibrosis in diabetes.

PKCepsilon overexpression, irrespective of genetic background, sensitizes skin to UVR-induced development of squamous-cell carcinomas.

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Sand, Jordan M; Aziz, Moammir H; Dreckschmidt, Nancy E; Havighurst, Thomas C; Kim, KyungMann; Oberley, Terry D; Verma, Ajit K

2010-01-01

Chronic exposure to UVR is the major etiologic factor in the development of human skin cancers including squamous-cell carcinoma (SCC). We have previously shown that protein Kinase C epsilon (PKCepsilon) transgenic mice on FVB/N background, which overexpress PKCepsilon protein approximately eightfold over endogenous levels in epidermis, exhibit about threefold more sensitivity than wild-type littermates to UVR-induced development of SCC. To determine whether it is PKCepsilon and not the mouse genetic background that determines susceptibility to UVR carcinogenesis, we cross-bred PKCepsilon FVB/N transgenic mice with SKH-1 hairless mice to generate PKCepsilon-overexpressing SKH-1 hairless mice. To evaluate the susceptibility of PKCepsilon SKH-1 hairless transgenic mice to UVR carcinogenesis, the mice were exposed to UVR (1-2 KJ m(-2)) three times weekly from a bank of six kodacel-filtered FS40 sunlamps. As compared with the wild-type hairless mice, PKCepsilon overexpression in SKH-1 hairless mice decreased the latency (12 weeks), whereas it increased the incidence (twofold) and multiplicity (fourfold) of SCC. The SKH hairless transgenic mice were observed to be as sensitive as FVB/N transgenic mice to UVR-induced development of SCC and expression of proliferative markers (proliferating cell nuclear antigen, signal transducers and activators of transcription 3, and extracellular signal-regulated kinase 1/2). The results indicate that PKCepsilon level dictates susceptibility, irrespective of genetic background, to UVR carcinogenesis.

ß-cell specific overexpression of suppressor of cytokine signalling-3 does not protect against multiple low dose streptozotocin induced type 1 diabetes in mice

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Börjesson, A; Rønn, S G; Karlsen, A E

2011-01-01

We investigated the impact of ß-cell specific overexpression of suppressor of cytokine signalling-3 (SOCS-3) on the development of multiple low dose streptozotocin (MLDSTZ) induced Type 1 diabetes and the possible mechanisms involved. MLDSTZ treatment was administered to RIP-SOCS-3 transgenic......RNA in islet cells and secretion of IL-1Ra into culture medium. MLDSTZ treatment caused gradual hyperglycemia both in the wt mice and in the transgenic mice with the latter tending to be more sensitive. In vitro experiments on wt and transgenic islets did not reveal any differences in sensitivity to damaging...

Targeting Protein Kinase CK2: Evaluating CX-4945 Potential for GL261 Glioblastoma Therapy in Immunocompetent Mice

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Laura Ferrer-Font

2017-02-01

Full Text Available Glioblastoma (GBM causes poor survival in patients even with aggressive treatment. Temozolomide (TMZ is the standard chemotherapeutic choice for GBM treatment but resistance always ensues. Protein kinase CK2 (CK2 contributes to tumour development and proliferation in cancer, and it is overexpressed in human GBM. Accordingly, targeting CK2 in GBM may benefit patients. Our goal has been to evaluate whether CK2 inhibitors (iCK2s could increase survival in an immunocompetent preclinical GBM model. Cultured GL261 cells were treated with different iCK2s including CX-4945, and target effects evaluated in vitro. CX-4945 was found to decrease CK2 activity and Akt(S129 phosphorylation in GL261 cells. Longitudinal in vivo studies with CX-4945 alone or in combination with TMZ were performed in tumour-bearing mice. Increase in survival (p < 0.05 was found with combined CX-4945 and TMZ metronomic treatment (54.7 ± 11.9 days, n = 6 when compared to individual metronomic treatments (CX-4945: 24.5 ± 2.0 and TMZ: 38.7 ± 2.7, n = 6 and controls (22.5 ± 1.2, n = 6. Despite this, CX-4945 did not improve mice outcome when administered on every/alternate days, either alone or in combination with 3-cycle TMZ. The highest survival rate was obtained with the metronomic combined TMZ+CX-4945 every 6 days, pointing to the participation of the immune system or other ancillary mechanism in therapy response.

Targeting Protein Kinase CK2: Evaluating CX-4945 Potential for GL261 Glioblastoma Therapy in Immunocompetent Mice

Science.gov (United States)

Ferrer-Font, Laura; Villamañan, Lucia; Arias-Ramos, Nuria; Vilardell, Jordi; Plana, Maria; Ruzzene, Maria; Pinna, Lorenzo A.; Itarte, Emilio; Arús, Carles; Candiota, Ana Paula

2017-01-01

Glioblastoma (GBM) causes poor survival in patients even with aggressive treatment. Temozolomide (TMZ) is the standard chemotherapeutic choice for GBM treatment but resistance always ensues. Protein kinase CK2 (CK2) contributes to tumour development and proliferation in cancer, and it is overexpressed in human GBM. Accordingly, targeting CK2 in GBM may benefit patients. Our goal has been to evaluate whether CK2 inhibitors (iCK2s) could increase survival in an immunocompetent preclinical GBM model. Cultured GL261 cells were treated with different iCK2s including CX-4945, and target effects evaluated in vitro. CX-4945 was found to decrease CK2 activity and Akt(S129) phosphorylation in GL261 cells. Longitudinal in vivo studies with CX-4945 alone or in combination with TMZ were performed in tumour-bearing mice. Increase in survival (p < 0.05) was found with combined CX-4945 and TMZ metronomic treatment (54.7 ± 11.9 days, n = 6) when compared to individual metronomic treatments (CX-4945: 24.5 ± 2.0 and TMZ: 38.7 ± 2.7, n = 6) and controls (22.5 ± 1.2, n = 6). Despite this, CX-4945 did not improve mice outcome when administered on every/alternate days, either alone or in combination with 3-cycle TMZ. The highest survival rate was obtained with the metronomic combined TMZ+CX-4945 every 6 days, pointing to the participation of the immune system or other ancillary mechanism in therapy response. PMID:28208677

HER2-Targeted Polyinosine/Polycytosine Therapy Inhibits Tumor Growth and Modulates the Tumor Immune Microenvironment.

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Zigler, Maya; Shir, Alexei; Joubran, Salim; Sagalov, Anna; Klein, Shoshana; Edinger, Nufar; Lau, Jeffrey; Yu, Shang-Fan; Mizraji, Gabriel; Globerson Levin, Anat; Sliwkowski, Mark X; Levitzki, Alexander

2016-08-01

The development of targeted therapies that affect multiple signaling pathways and stimulate antitumor immunity is greatly needed. About 20% of patients with breast cancer overexpress HER2. Small molecules and antibodies targeting HER2 convey some survival benefits; however, patients with advanced disease succumb to the disease under these treatment regimens, possibly because HER2 is not completely necessary for the survival of the targeted cancer cells. In the present study, we show that a polyinosine/polycytosine (pIC) HER2-homing chemical vector induced the demise of HER2-overexpressing breast cancer cells, including trastuzumab-resistant cells. Targeting pIC to the tumor evoked a number of cell-killing mechanisms, as well as strong bystander effects. These bystander mechanisms included type I IFN induction, immune cell recruitment, and activation. The HER2-targeted pIC strongly inhibited the growth of HER2-overexpressing tumors in immunocompetent mice. The data presented here could open additional avenues in the treatment of HER2-positive breast cancer. Cancer Immunol Res; 4(8); 688-97. ©2016 AACR. ©2016 American Association for Cancer Research.

Deletion of circadian gene Per1 alleviates acute ethanol-induced hepatotoxicity in mice

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Wang, Tao; Yang, Ping; Zhan, Yibei; Xia, Lin; Hua, Zichun; Zhang, Jianfa

2013-01-01

The severity of ethanol-induced liver injury is associated with oxidative stress and lipid accumulation in the liver. Core circadian clock is known to mediate antioxidative enzyme activity and lipid metabolism. However, the link between circadian clock and ethanol-induced hepatotoxicity remains unclear. Here we showed that extents of acute ethanol-induced liver injury and steatosis in mice exhibit circadian variations consistent with hepatic expression of Period (Per) genes. Mice lacking clock gene Per1 displayed less susceptible to ethanol-induced liver injury, as evidenced by lower serum transaminase activity and less severe histopathological changes. Ethanol-induced lipid peroxidation was alleviated in Per1−/− mice. However, Per1 deletion had no effect on antioxidants depletion caused by ethanol administration. Ethanol-induced triglycerides (TG) accumulation in the serum and liver was significantly decreased in Per1−/− mice compared with that in wild-type (WT) mice. Analysis of gene expression in the liver revealed peroxisome proliferators activated receptor-gamma (PPARγ) and its target genes related to TG synthesis are remarkably down-regulated in Per1−/− mice. HepG2 cells were treated with ethanol at 150 mM for 3 days. Per1 overexpression augmented lipid accumulation after treatment with ethanol in HepG2 cells, but had no effect on ethanol-induced oxidative stress. Expression of genes related to lipogenesis, including PPARγ and its target genes, was up-regulated in cells overexpressing Per1. In conclusion, these results indicated that circadian rhythms of ethanol-induced hepatotoxicity are controlled by clock gene Per1, and deletion of Per1 protected mice from ethanol-induced liver injury by decreasing hepatic lipid accumulation

Effects of transgenic methionine sulfoxide reductase A (MsrA expression on lifespan and age-dependent changes in metabolic function in mice

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Adam B. Salmon

2016-12-01

Full Text Available Mechanisms that preserve and maintain the cellular proteome are associated with long life and healthy aging. Oxidative damage is a significant contributor to perturbation of proteostasis and is dealt with by the cell through regulation of antioxidants, protein degradation, and repair of oxidized amino acids. Methionine sulfoxide reductase A (MsrA repairs oxidation of free- and protein-bound methionine residues through enzymatic reduction and is found in both the cytosol and the mitochondria. Previous studies in Drosophila have shown that increasing expression of MsrA can extend longevity. Here we test the effects of increasing MsrA on longevity and healthy aging in two transgenic mouse models. We show that elevated expression of MsrA targeted specifically to the cytosol reduces the rate of age-related death in female mice when assessed by Gompertz analysis. However, neither cytosolic nor mitochondrial MsrA overexpression extends lifespan when measured by log-rank analysis. In mice with MsrA overexpression targeted to the mitochondria, we see evidence for improved insulin sensitivity in aged female mice. With these and our previous data, we conclude that the increasing MsrA expression in mice has differential effects on aging and healthy aging that are dependent on the target of its subcellular localization.

Hepatic Cholesterol-25-Hydroxylase Overexpression Improves Systemic Insulin Sensitivity in Mice

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Britta Noebauer

2017-01-01

Full Text Available Obesity is a major risk factor for several diseases including diabetes, heart disease, and some forms of cancer and due to its rapidly increasing prevalence it has become one of the biggest problems medicine is facing today. All the more surprising, a substantial percentage of obese patients are metabolically healthy when classified based on insulin resistance and systemic inflammation. Oxysterols are naturally occurring molecules that play important role in various metabolic and inflammatory processes and their levels are elevated in patients suffering from obesity and diabetes. 25-Hydroxycholesterol (25-OHC is produced in cells from cholesterol by the enzyme cholesterol 25-hydroxylase (Ch25h and is involved in lipid metabolism, inflammatory processes, and cell proliferation. Here, we investigated the role of hepatic Ch25h in the transition from metabolically healthy obesity to insulin resistance and diabetes. Using several different experimental approaches, we demonstrated the significance of Ch25h on the border of “healthy” and “diseased” states of obesity. Adenovirus-mediated Ch25h overexpression in mice improved glucose tolerance and insulin sensitivity and lowered HOMA-IR. Our data suggest that low hepatic Ch25h levels could be considered a risk marker for unhealthy obesity.

Epigenetic modification of miR-10a regulates renal damage by targeting CREB1 in type 2 diabetes mellitus

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Shan, Qun, E-mail: shanp@jsnu.edu.cn; Zheng, Guihong, E-mail: ghzhengsd@jsnu.edu.cn; Zhu, Aihua, E-mail: ahzhu@jsnu.edu.cn; Cao, Li, E-mail: 948113717@qq.com; Lu, Jun, E-mail: lu-jun75@163.com; Wu, Dongmei, E-mail: wdm8610@jsnu.edu.cn; Zhang, ZiFeng, E-mail: zhangzifengsuper@jsnu.edu.cn; Fan, Shaohua, E-mail: fshfly@126.com; Sun, Chunhui, E-mail: 306484866@qq.com; Hu, Bin, E-mail: hubin@jsnu.edu.cn; Zheng, Yuanlin, E-mail: ylzheng@jsnu.edu.cn

2016-09-01

Emerging evidence has shown that microRNA-mediated gene expression modulation plays a crucial role in the pathogenesis of type 2 diabetes mellitus, but the novel miRNAs involved in type 2 diabetes and its functional regulatory mechanisms still need to be determined. In this study, we assessed the role of miR-10a in extracellular matrix accumulation in the kidney of diabetic mellitus induced by combining administration of chronic high fat diet (HFD) and low dosage of streptozotocin (STZ, 35 mg/kg). Here, we found that HFD/STZ administration decreased the level of microRNA (miR-10a) expression in ICR strain mice. Overexpression of miR-10a alleviated the increased ratio of urine albumin-to-creatinine (ACR) ratio of HFD/STZ mice. In contrast, knockdown of miR-10a increased the ratio of kidney ACR in naïve mice. Furthermore, cAMP response element binding protein 1 (CREB1) was validated as a target of miR-10a in vitro and in vivo. CREB1 and its downstream fibronectin (FN, extracellular matrix) were increased in HFD/STZ-treated mice, which was reversed by kidney miR-10a overexpression. The content of CREB1 and FN was increased by miR-10a knockdown in kidney of naïve mice. Furthermore, histone deacetylase 3 (HDAC3) was revealed to be increased in kidney of HFD/STZ mice, accompanied with the augmentation of ACR ratio and FN level. Knockdown of HDAC3 with siRNA significantly caused the increase of miR-10a, resulting in the decrease in CREB1 and FN expression in kidney of HFD/STZ mice. Contrarily, HDAC3 overexpression mediated by lentivirus decreased miR-10a content, and enhanced ACR value, CREB1 and FN formation in naïve mice. Collectively, these results elucidate that HDAC3/miR-10a/CREB1 serves as a new mechanism underlying kidney injury, providing potential therapeutic targets in type 2 diabetes. - Highlights: • Diabetes induces the decrease of miR-10a level in the kidney. • MiR-10a overexpression improves kidney damage of diabetes. • MiR-10a targeting CREB1/FN

Epigenetic modification of miR-10a regulates renal damage by targeting CREB1 in type 2 diabetes mellitus

International Nuclear Information System (INIS)

Shan, Qun; Zheng, Guihong; Zhu, Aihua; Cao, Li; Lu, Jun; Wu, Dongmei; Zhang, ZiFeng; Fan, Shaohua; Sun, Chunhui; Hu, Bin; Zheng, Yuanlin

2016-01-01

Emerging evidence has shown that microRNA-mediated gene expression modulation plays a crucial role in the pathogenesis of type 2 diabetes mellitus, but the novel miRNAs involved in type 2 diabetes and its functional regulatory mechanisms still need to be determined. In this study, we assessed the role of miR-10a in extracellular matrix accumulation in the kidney of diabetic mellitus induced by combining administration of chronic high fat diet (HFD) and low dosage of streptozotocin (STZ, 35 mg/kg). Here, we found that HFD/STZ administration decreased the level of microRNA (miR-10a) expression in ICR strain mice. Overexpression of miR-10a alleviated the increased ratio of urine albumin-to-creatinine (ACR) ratio of HFD/STZ mice. In contrast, knockdown of miR-10a increased the ratio of kidney ACR in naïve mice. Furthermore, cAMP response element binding protein 1 (CREB1) was validated as a target of miR-10a in vitro and in vivo. CREB1 and its downstream fibronectin (FN, extracellular matrix) were increased in HFD/STZ-treated mice, which was reversed by kidney miR-10a overexpression. The content of CREB1 and FN was increased by miR-10a knockdown in kidney of naïve mice. Furthermore, histone deacetylase 3 (HDAC3) was revealed to be increased in kidney of HFD/STZ mice, accompanied with the augmentation of ACR ratio and FN level. Knockdown of HDAC3 with siRNA significantly caused the increase of miR-10a, resulting in the decrease in CREB1 and FN expression in kidney of HFD/STZ mice. Contrarily, HDAC3 overexpression mediated by lentivirus decreased miR-10a content, and enhanced ACR value, CREB1 and FN formation in naïve mice. Collectively, these results elucidate that HDAC3/miR-10a/CREB1 serves as a new mechanism underlying kidney injury, providing potential therapeutic targets in type 2 diabetes. - Highlights: • Diabetes induces the decrease of miR-10a level in the kidney. • MiR-10a overexpression improves kidney damage of diabetes. • MiR-10a targeting CREB1/FN

Electrical remodeling of cardiac myocytes from mice with heart failure due to the overexpression of tumor necrosis factor-alpha.

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Petkova-Kirova, Polina S; Gursoy, Erdal; Mehdi, Haider; McTiernan, Charles F; London, Barry; Salama, Guy

2006-05-01

Mice that overexpress the inflammatory cytokine tumor necrosis factor-alpha in the heart (TNF mice) develop heart failure characterized by atrial and ventricular dilatation, decreased ejection fraction, atrial and ventricular arrhythmias, and increased mortality (males > females). Abnormalities in Ca2+ handling, prolonged action potential duration (APD), calcium alternans, and reentrant atrial and ventricular arrhythmias were previously observed with the use of optical mapping of perfused hearts from TNF mice. We therefore tested whether altered voltage-gated outward K+ and/or inward Ca2+ currents contribute to the altered action potential characteristics and the increased vulnerability to arrhythmias. Whole cell voltage-clamp recordings of K+ currents from left ventricular myocytes of TNF mice revealed an approximately 50% decrease in the rapidly activating, rapidly inactivating transient outward K+ current Ito and in the rapidly activating, slowly inactivating delayed rectifier current IK,slow1, an approximately 25% decrease in the rapidly activating, slowly inactivating delayed rectifier current IK,slow2, and no significant change in the steady-state current Iss compared with controls. Peak amplitudes and inactivation kinetics of the L-type Ca2+ current ICa,L were not altered. Western blot analyses revealed a reduction in the proteins underlying Kv4.2, Kv4.3, and Kv1.5. Thus decreased K+ channel expression is largely responsible for the prolonged APD in the TNF mice and may, along with abnormalities in Ca2+ handling, contribute to arrhythmias.

Overexpression of Latent TGFβ Binding Protein 4 in Muscle Ameliorates Muscular Dystrophy through Myostatin and TGFβ.

Science.gov (United States)

Lamar, Kay-Marie; Bogdanovich, Sasha; Gardner, Brandon B; Gao, Quan Q; Miller, Tamari; Earley, Judy U; Hadhazy, Michele; Vo, Andy H; Wren, Lisa; Molkentin, Jeffery D; McNally, Elizabeth M

2016-05-01

Latent TGFβ binding proteins (LTBPs) regulate the extracellular availability of latent TGFβ. LTBP4 was identified as a genetic modifier of muscular dystrophy in mice and humans. An in-frame insertion polymorphism in the murine Ltbp4 gene associates with partial protection against muscular dystrophy. In humans, nonsynonymous single nucleotide polymorphisms in LTBP4 associate with prolonged ambulation in Duchenne muscular dystrophy. To better understand LTBP4 and its role in modifying muscular dystrophy, we created transgenic mice overexpressing the protective murine allele of LTBP4 specifically in mature myofibers using the human skeletal actin promoter. Overexpression of LTBP4 protein was associated with increased muscle mass and proportionally increased strength compared to age-matched controls. In order to assess the effects of LTBP4 in muscular dystrophy, LTBP4 overexpressing mice were bred to mdx mice, a model of Duchenne muscular dystrophy. In this model, increased LTBP4 led to greater muscle mass with proportionally increased strength, and decreased fibrosis. The increase in muscle mass and reduction in fibrosis were similar to what occurs when myostatin, a related TGFβ family member and negative regulator of muscle mass, was deleted in mdx mice. Supporting this, we found that myostatin forms a complex with LTBP4 and that overexpression of LTBP4 led to a decrease in myostatin levels. LTBP4 also interacted with TGFβ and GDF11, a protein highly related to myostatin. These data identify LTBP4 as a multi-TGFβ family ligand binding protein with the capacity to modify muscle disease through overexpression.

Overexpression of Latent TGFβ Binding Protein 4 in Muscle Ameliorates Muscular Dystrophy through Myostatin and TGFβ.

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Kay-Marie Lamar

2016-05-01

Full Text Available Latent TGFβ binding proteins (LTBPs regulate the extracellular availability of latent TGFβ. LTBP4 was identified as a genetic modifier of muscular dystrophy in mice and humans. An in-frame insertion polymorphism in the murine Ltbp4 gene associates with partial protection against muscular dystrophy. In humans, nonsynonymous single nucleotide polymorphisms in LTBP4 associate with prolonged ambulation in Duchenne muscular dystrophy. To better understand LTBP4 and its role in modifying muscular dystrophy, we created transgenic mice overexpressing the protective murine allele of LTBP4 specifically in mature myofibers using the human skeletal actin promoter. Overexpression of LTBP4 protein was associated with increased muscle mass and proportionally increased strength compared to age-matched controls. In order to assess the effects of LTBP4 in muscular dystrophy, LTBP4 overexpressing mice were bred to mdx mice, a model of Duchenne muscular dystrophy. In this model, increased LTBP4 led to greater muscle mass with proportionally increased strength, and decreased fibrosis. The increase in muscle mass and reduction in fibrosis were similar to what occurs when myostatin, a related TGFβ family member and negative regulator of muscle mass, was deleted in mdx mice. Supporting this, we found that myostatin forms a complex with LTBP4 and that overexpression of LTBP4 led to a decrease in myostatin levels. LTBP4 also interacted with TGFβ and GDF11, a protein highly related to myostatin. These data identify LTBP4 as a multi-TGFβ family ligand binding protein with the capacity to modify muscle disease through overexpression.

Metallothionein-I overexpression alters brain inflammation and stimulates brain repair in transgenic mice with astrocyte-targeted interleukin-6 expression

DEFF Research Database (Denmark)

Penkowa, Milena; Camats, Jordi; Giralt, Mercedes

2003-01-01

injury, such as a cryolesion, demonstrate a neuroprotective role of IL-6. Thus, the GFAP-IL-6 mice showed faster tissue repair and decreased oxidative stress and apoptosis compared with control litter-mate mice. The neuroprotective factors metallothionein-I+II (MT-I+II) were upregulated by the cryolesion...... the inflammatory response, decreased oxidative stress and apoptosis significantly, and increased brain tissue repair in comparison with either GFAP-IL-6 or control litter-mate mice. Overall, the results demonstrate that brain MT-I+II proteins are fundamental neuroprotective factors....

Fractalkine overexpression suppresses tau pathology in a mouse model of tauopathy.

Science.gov (United States)

Nash, Kevin R; Lee, Daniel C; Hunt, Jerry B; Morganti, Josh M; Selenica, Maj-Linda; Moran, Peter; Reid, Patrick; Brownlow, Milene; Guang-Yu Yang, Clement; Savalia, Miloni; Gemma, Carmelina; Bickford, Paula C; Gordon, Marcia N; Morgan, David

2013-06-01

Alzheimer's disease is characterized by amyloid plaques, neurofibrillary tangles, glial activation, and neurodegeneration. In mouse models, inflammatory activation of microglia accelerates tau pathology. The chemokine fractalkine serves as an endogenous neuronal modulator to quell microglial activation. Experiments with fractalkine receptor null mice suggest that fractalkine signaling diminishes tau pathology, but exacerbates amyloid pathology. Consistent with this outcome, we report here that soluble fractalkine overexpression using adeno-associated viral vectors significantly reduced tau pathology in the rTg4510 mouse model of tau deposition. Furthermore, this treatment reduced microglial activation and appeared to prevent neurodegeneration normally found in this model. However, in contrast to studies with fractalkine receptor null mice, parallel studies in an APP/PS1 model found no effect of increased fractalkine signaling on amyloid deposition. These data argue that agonism at fractalkine receptors might be an excellent target for therapeutic intervention in tauopathies, including those associated with amyloid deposition. Copyright © 2013 Elsevier Inc. All rights reserved.

Kaiso overexpression promotes intestinal inflammation and potentiates intestinal tumorigenesis in Apc(Min/+) mice.

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Pierre, Christina C; Longo, Joseph; Mavor, Meaghan; Milosavljevic, Snezana B; Chaudhary, Roopali; Gilbreath, Ebony; Yates, Clayton; Daniel, Juliet M

2015-09-01

Constitutive Wnt/β-catenin signaling is a key contributor to colorectal cancer (CRC). Although inactivation of the tumor suppressor adenomatous polyposis coli (APC) is recognized as an early event in CRC development, it is the accumulation of multiple subsequent oncogenic insults facilitates malignant transformation. One potential contributor to colorectal carcinogenesis is the POZ-ZF transcription factor Kaiso, whose depletion extends lifespan and delays polyp onset in the widely used Apc(Min/+) mouse model of intestinal cancer. These findings suggested that Kaiso potentiates intestinal tumorigenesis, but this was paradoxical as Kaiso was previously implicated as a negative regulator of Wnt/β-catenin signaling. To resolve Kaiso's role in intestinal tumorigenesis and canonical Wnt signaling, we generated a transgenic mouse model (Kaiso(Tg/+)) expressing an intestinal-specific myc-tagged Kaiso transgene. We then mated Kaiso(Tg/+) and Apc(Min/+) mice to generate Kaiso(Tg/+):Apc(Min/+) mice for further characterization. Kaiso(Tg/+):Apc(Min/+) mice exhibited reduced lifespan and increased polyp multiplicity compared to Apc(Min/+) mice. Consistent with this murine phenotype, we found increased Kaiso expression in human CRC tissue, supporting a role for Kaiso in human CRC. Interestingly, Wnt target gene expression was increased in Kaiso(Tg/+):Apc(Min/+) mice, suggesting that Kaiso's function as a negative regulator of canonical Wnt signaling, as seen in Xenopus, is not maintained in this context. Notably, Kaiso(Tg/+):Apc(Min/+) mice exhibited increased inflammation and activation of NFκB signaling compared to their Apc(Min/+) counterparts. This phenotype was consistent with our previous report that Kaiso(Tg/+) mice exhibit chronic intestinal inflammation. Together our findings highlight a role for Kaiso in promoting Wnt signaling, inflammation and tumorigenesis in the mammalian intestine. Copyright © 2015 Elsevier B.V. All rights reserved.

Matrix-Dependent Regulation of AKT in Hepsin-Overexpressing PC3 Prostate Cancer Cells

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Stephanie M Wittig-Blaich

2011-07-01

Full Text Available The serine-protease hepsin is one of the most prominently overexpressed genes in human prostate carcinoma. Forced expression of the enzyme in mice prostates is associated with matrix degradation, invasive growth, and prostate cancer progression. Conversely, hepsin overexpression in metastatic prostate cancer cell lines was reported to induce cell cycle arrest and reduction of invasive growth in vitro. We used a system for doxycycline (dox-inducible target gene expression in metastasis-derived PC3 cells to analyze the effects of hepsin in a quantitative manner. Loss of viability and adhesion correlated with hepsin expression levels during anchorage-dependent but not anchorage-independent growth. Full expression of hepsin led to cell death and detachment and was specifically associated with reduced phosphorylation of AKT at Ser473, which was restored by growth on matrix derived from RWPE1 normal prostatic epithelial cells. In the chorioallantoic membrane xenograft model, hepsin overexpression in PC3 cells reduced the viability of tumors but did not suppress invasive growth. The data presented here provide evidence that elevated levels of hepsin interfere with cell adhesion and viability in the background of prostate cancer as well as other tissue types, the details of which depend on the microenvironment provided. Our findings suggest that overexpression of the enzyme in prostate carcinogenesis must be spatially and temporally restricted for the efficient development of tumors and metastases.

Overexpression of the ped/pea-15 Gene Causes Diabetes by Impairing Glucose-Stimulated Insulin Secretion in Addition to Insulin Action

OpenAIRE

Vigliotta, Giovanni; Miele, Claudia; Santopietro, Stefania; Portella, Giuseppe; Perfetti, Anna; Maitan, Maria Alessandra; Cassese, Angela; Oriente, Francesco; Trencia, Alessandra; Fiory, Francesca; Romano, Chiara; Tiveron, Cecilia; Tatangelo, Laura; Troncone, Giancarlo; Formisano, Pietro

2004-01-01

Overexpression of the ped/pea-15 gene is a common feature of type 2 diabetes. In the present work, we show that transgenic mice ubiquitously overexpressing ped/pea-15 exhibited mildly elevated random-fed blood glucose levels and decreased glucose tolerance. Treatment with a 60% fat diet led ped/pea-15 transgenic mice to develop diabetes. Consistent with insulin resistance in these mice, insulin administration reduced glucose levels by only 35% after 45 min, compared to 70% in control mice. In...

Radioimmunodetection of human leukemia with anti-interleukin-2 receptor antibody in severe combined immunodeficiency mice

International Nuclear Information System (INIS)

Hosono, Makoto; Takaori-Kondo, Akifumi; Zheng-Sheng, Yao; Kobayashi, Hisataka; Hosono, Masako N.; Sakahara, Harumi; Imada, Kazunori; Okuma, Minoru; Uchiyama, Takashi; Konishi, Junji

1995-01-01

Anti-Tac monoclonal antibody recognizes human interleukin-2 receptor, which is overexpressed in leukemic cells of most adult T-cell leukemia (ATL) patients. To examine the potency of anti-Tac for targeting of ATL, biodistributions of intravenously administered 125 I- and 111 In-labeled anti-Tac were examined in severe combined immunodeficiency (SCID) mice inoculated with ATL cells. Significant amounts of radiolabeled anti-Tac were found in the spleen and thymus. The trafficking of ATL cells in SCID mice was detected using 111 In-oxine-labeled ATL cells. These results were coincident with the histologically confirmed infiltration of ATL cells. The radiolabeled anti-Tac seemed potent for targeting of ATL

Targeted Deletion of Kynurenine 3-Monooxygenase in Mice

Science.gov (United States)

Giorgini, Flaviano; Huang, Shao-Yi; Sathyasaikumar, Korrapati V.; Notarangelo, Francesca M.; Thomas, Marian A. R.; Tararina, Margarita; Wu, Hui-Qiu; Schwarcz, Robert; Muchowski, Paul J.

2013-01-01

Kynurenine 3-monooxygenase (KMO), a pivotal enzyme in the kynurenine pathway (KP) of tryptophan degradation, has been suggested to play a major role in physiological and pathological events involving bioactive KP metabolites. To explore this role in greater detail, we generated mice with a targeted genetic disruption of Kmo and present here the first biochemical and neurochemical characterization of these mutant animals. Kmo−/− mice lacked KMO activity but showed no obvious abnormalities in the activity of four additional KP enzymes tested. As expected, Kmo−/− mice showed substantial reductions in the levels of its enzymatic product, 3-hydroxykynurenine, in liver, brain, and plasma. Compared with wild-type animals, the levels of the downstream metabolite quinolinic acid were also greatly decreased in liver and plasma of the mutant mice but surprisingly were only slightly reduced (by ∼20%) in the brain. The levels of three other KP metabolites: kynurenine, kynurenic acid, and anthranilic acid, were substantially, but differentially, elevated in the liver, brain, and plasma of Kmo−/− mice, whereas the liver and brain content of the major end product of the enzymatic cascade, NAD+, did not differ between Kmo−/− and wild-type animals. When assessed by in vivo microdialysis, extracellular kynurenic acid levels were found to be significantly elevated in the brains of Kmo−/− mice. Taken together, these results provide further evidence that KMO plays a key regulatory role in the KP and indicate that Kmo−/− mice will be useful for studying tissue-specific functions of individual KP metabolites in health and disease. PMID:24189070

Matrix-Dependent Regulation of AKT in Hepsin-Overexpressing PC3 Prostate Cancer Cells12

Science.gov (United States)

Wittig-Blaich, Stephanie M; Kacprzyk, Lukasz A; Eismann, Thorsten; Bewerunge-Hudler, Melanie; Kruse, Petra; Winkler, Eva; Strauss, Wolfgang S L; Hibst, Raimund; Steiner, Rudolf; Schrader, Mark; Mertens, Daniel; Sültmann, Holger; Wittig, Rainer

2011-01-01

The serine-protease hepsin is one of the most prominently overexpressed genes in human prostate carcinoma. Forced expression of the enzyme in mice prostates is associated with matrix degradation, invasive growth, and prostate cancer progression. Conversely, hepsin overexpression in metastatic prostate cancer cell lines was reported to induce cell cycle arrest and reduction of invasive growth in vitro. We used a system for doxycycline (dox)-inducible target gene expression in metastasis-derived PC3 cells to analyze the effects of hepsin in a quantitative manner. Loss of viability and adhesion correlated with hepsin expression levels during anchorage-dependent but not anchorage-independent growth. Full expression of hepsin led to cell death and detachment and was specifically associated with reduced phosphorylation of AKT at Ser473, which was restored by growth on matrix derived from RWPE1 normal prostatic epithelial cells. In the chorioallantoic membrane xenograft model, hepsin overexpression in PC3 cells reduced the viability of tumors but did not suppress invasive growth. The data presented here provide evidence that elevated levels of hepsin interfere with cell adhesion and viability in the background of prostate cancer as well as other tissue types, the details of which depend on the microenvironment provided. Our findings suggest that overexpression of the enzyme in prostate carcinogenesis must be spatially and temporally restricted for the efficient development of tumors and metastases. PMID:21750652

Smad6/Smurf1 overexpression in cartilage delays chondrocyte hypertrophy and causes dwarfism with osteopenia

Science.gov (United States)

Horiki, Mitsuru; Imamura, Takeshi; Okamoto, Mina; Hayashi, Makoto; Murai, Junko; Myoui, Akira; Ochi, Takahiro; Miyazono, Kohei; Yoshikawa, Hideki; Tsumaki, Noriyuki

2004-01-01

Biochemical experiments have shown that Smad6 and Smad ubiquitin regulatory factor 1 (Smurf1) block the signal transduction of bone morphogenetic proteins (BMPs). However, their in vivo functions are largely unknown. Here, we generated transgenic mice overexpressing Smad6 in chondrocytes. Smad6 transgenic mice showed postnatal dwarfism with osteopenia and inhibition of Smad1/5/8 phosphorylation in chondrocytes. Endochondral ossification during development in these mice was associated with almost normal chondrocyte proliferation, significantly delayed chondrocyte hypertrophy, and thin trabecular bone. The reduced population of hypertrophic chondrocytes after birth seemed to be related to impaired bone growth and formation. Organ culture of cartilage rudiments showed that chondrocyte hypertrophy induced by BMP2 was inhibited in cartilage prepared from Smad6 transgenic mice. We then generated transgenic mice overexpressing Smurf1 in chondrocytes. Abnormalities were undetectable in Smurf1 transgenic mice. Mating Smad6 and Smurf1 transgenic mice produced double-transgenic pups with more delayed endochondral ossification than Smad6 transgenic mice. These results provided evidence that Smurf1 supports Smad6 function in vivo. PMID:15123739

Adenoviral gene transfer of PLD1-D4 enhances insulin sensitivity in mice by disrupting phospholipase D1 interaction with PED/PEA-15.

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Angela Cassese

Full Text Available Over-expression of phosphoprotein enriched in diabetes/phosphoprotein enriched in astrocytes (PED/PEA-15 causes insulin resistance by interacting with the D4 domain of phospholipase D1 (PLD1. Indeed, the disruption of this association restores insulin sensitivity in cultured cells over-expressing PED/PEA-15. Whether the displacement of PLD1 from PED/PEA-15 improves insulin sensitivity in vivo has not been explored yet. In this work we show that treatment with a recombinant adenoviral vector containing the human D4 cDNA (Ad-D4 restores normal glucose homeostasis in transgenic mice overexpressing PED/PEA-15 (Tg ped/pea-15 by improving both insulin sensitivity and secretion. In skeletal muscle of these mice, D4 over-expression inhibited PED/PEA-15-PLD1 interaction, decreased Protein Kinase C alpha activation and restored insulin induced Protein Kinase C zeta activation, leading to amelioration of insulin-dependent glucose uptake. Interestingly, Ad-D4 administration improved insulin sensitivity also in high-fat diet treated obese C57Bl/6 mice. We conclude that PED/PEA-15-PLD1 interaction may represent a novel target for interventions aiming at improving glucose tolerance.

Overexpression of hepatoma-derived growth factor in melanocytes does not lead to oncogenic transformation

International Nuclear Information System (INIS)

Sedlmaier, Angela; Wernert, Nicolas; Gallitzendörfer, Rainer; Abouzied, Mekky M; Gieselmann, Volkmar; Franken, Sebastian

2011-01-01

HDGF is a growth factor which is overexpressed in a wide range of tumors. Importantly, expression levels were identified as a prognostic marker in some types of cancer such as melanoma. To investigate the presumed oncogenic/transforming capacity of HDGF, we generated transgenic mice overexpressing HDGF in melanocytes. These mice were bred with mice heterozygous for a defective copy of the Ink4a tumor suppressor gene and were exposed to UV light to increase the risk for tumor development both genetically and physiochemically. Mice were analyzed by immunohistochemistry and Western blotting. Furthermore, primary melanocytes were isolated from different strains created. Transgenic animals overexpressed HDGF in hair follicle melanocytes. Interestingly, primary melanocytes isolated from transgenic animals were not able to differentiate in vitro whereas cells isolated from wild type and HDGF-deficient animals were. Although, HDGF -/- /Ink4a +/- mice displayed an increased number of epidermoid cysts after exposure to UV light, no melanomas or premelanocytic alterations could be detected in this mouse model. The results therefore provide no evidence that HDGF has a transforming capacity in tumor development. Our results in combination with previous findings point to a possible role in cell differentiation and suggest that HDGF promotes tumor progression after secondary upregulation and may represent another protein fitting into the concept of non-oncogene addiction of tumor tissue

Photodynamic therapy targeting neuropilin-1: Interest of pseudopeptides with improved stability properties.

Science.gov (United States)

Thomas, Noémie; Pernot, Marlène; Vanderesse, Régis; Becuwe, Philippe; Kamarulzaman, Ezatul; Da Silva, David; François, Aurélie; Frochot, Céline; Guillemin, François; Barberi-Heyob, Muriel

2010-07-15

The general strategy developed aims to favor the vascular effect of photodynamic therapy by targeting tumor vasculature. Since angiogenic endothelial cells represent an interesting target to potentiate this vascular effect, we previously described the conjugation of a photosensitizer to a peptide targeting neuropilins (NRPs) over-expressed specially in tumor angiogenic vessels and we recently characterized the mechanism of photosensitization-induced thrombogenic events. Nevertheless, in glioma-bearing nude mice, we demonstrated that the peptide moiety was degraded to various rates according to time after intravenous administration. In this study, new peptidases-resistant pseudopeptides were tested, demonstrating a molecular affinity for NRP-1 and NRP-2 recombinant chimeric proteins and devoid of affinity for VEGF receptor type 1 (Flt-1). To argue the involvement of NRP-1, MDA-MB-231 breast cancer cells were used, strongly over-expressing NRP-1 receptor. We evidenced a statistically significant decrease of the different peptides-conjugated photosensitizers uptake after RNA interference-mediated silencing of NRP-1. Peptides-conjugated photosensitizers allowed a selective accumulation into cells. In mice, no degradation was observed in plasma in vivo 4h after intravenous injection by MALDI-TOF mass spectrometry. This study draws attention to this potential problem with peptides, especially in the case of targeting strategies, and provides useful information for the future design of more stable molecules. 2010 Elsevier Inc. All rights reserved.

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

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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.

Over-expression of Stat5b confers protection against diabetes in the non-obese diabetic (NOD) mice via up-regulation of CD4+CD25+ regulatory T cells

International Nuclear Information System (INIS)

Jin, Yulan; Purohit, Sharad; Chen, Xueqin; Yi, Bing; She, Jin-Xiong

2012-01-01

Highlights: ► This is the first study to provide direct evidence of the role of Stat5b in NOD mice. ► Over-expression of wild type Stat5b transgene protects NOD mice against diabetes. ► This protection may be mediated by the up-regulation of CD4 + CD25 + Tregs. -- Abstract: The signal transducers and activators of transcription (STAT) family of proteins play a critical role in cytokine signaling required for fine tuning of immune regulation. Previous reports showed that a mutation (L327M) in the Stat5b protein leads to aberrant cytokine signaling in the NOD mice. To further elaborate the role of Stat5b in diabetes, we established a NOD transgenic mouse that over-expresses the wild type Stat5b gene. The incidences of spontaneous diabetes as well as cyclophosphamide-induced diabetes were significantly reduced and delayed in the Stat5b transgenic NOD mice compared to their littermate controls. The total cell numbers of CD4 + T cells and especially CD8 + T cells in the spleen and pancreatic lymph node were increased in the Stat5b transgenic NOD mice. Consistent with these findings, CD4 + and CD8 + T cells from the Stat5b transgenic NOD mice showed a higher proliferation capacity and up-regulation of multiple cytokines including IL-2, IFN-γ, TNF-α and IL-10 as well as anti-apoptotic gene Bcl-xl. Furthermore, the number and proportion of CD4 + CD25 + regulatory T cells were significantly increased in transgenic mice although in vitro suppression ability of the regulatory T-cells was not affected by the transgene. Our results suggest that Stat5b confers protection against diabetes in the NOD mice by regulating the numbers and function of multiple immune cell types, especially by up-regulating CD4 + CD25 + regulatory T cells.

Resistance to the Beneficial Metabolic Effects and Hepatic Antioxidant Defense Actions of Fibroblast Growth Factor 21 Treatment in Growth Hormone-Overexpressing Transgenic Mice

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Ravneet K. Boparai

2015-01-01

Full Text Available Fibroblast growth factor 21 (FGF21 modulates a diverse range of biological functions, including glucose and lipid metabolism, adaptive starvation response, and energy homeostasis, but with limited mechanistic insight. FGF21 treatment has been shown to inhibit hepatic growth hormone (GH intracellular signaling. To evaluate GH axis involvement in FGF21 actions, transgenic mice overexpressing bovine GH were used. Expectedly, in response to FGF21 treatment control littermates showed metabolic improvements whereas GH transgenic mice resisted most of the beneficial effects of FGF21, except an attenuation of the innate hyperinsulinemia. Since FGF21 is believed to exert its effects mostly at the transcriptional level, we analyzed and observed significant upregulation in expression of various genes involved in carbohydrate and lipid metabolism, energy homeostasis, and antioxidant defense in FGF21-treated controls, but not in GH transgenics. The resistance of GH transgenic mice to FGF21-induced changes underlines the necessity of normal GH signaling for the beneficial effects of FGF21.

Impaired growth of pancreatic exocrine cells in transgenic mice expressing human activin βE subunit

International Nuclear Information System (INIS)

Hashimoto, Osamu; Ushiro, Yuuki; Sekiyama, Kazunari; Yamaguchi, Osamu; Yoshioka, Kazuki; Mutoh, Ken-Ichiro; Hasegawa, Yoshihisa

2006-01-01

Activins, TGF-β superfamily members, have multiple functions in a variety of cells and tissues. Recently, additional activin β subunit genes, βC and βE, have been identified. To explore the role of activin E, we created transgenic mice overexpressing human activin βE subunit. There were pronounced differences in the pancreata of the transgenic animals as compared with their wild-type counterparts. Pancreatic weight, expressed relative to total body weight, was significantly reduced. Histologically, adipose replacement of acini in the exocrine pancreas was observed. There was a significant decrease in the number of PCNA-positive cells in the acinar cells, indicating reduced proliferation in the exocrine pancreas of the transgenic mice. However, quantitative pancreatic morphometry showed that the total number and mass of the islets of the transgenic mice were comparable with those of the nontransgenic control mice. Our findings suggest a role for activin E in regulating the proliferation of pancreatic exocrine cells

MicroRNA-Mediated Rescue of Fear Extinction Memory by miR-144-3p in Extinction-Impaired Mice.

Science.gov (United States)

Murphy, Conor P; Li, Xiang; Maurer, Verena; Oberhauser, Michael; Gstir, Ronald; Wearick-Silva, Luis Eduardo; Viola, Thiago Wendt; Schafferer, Simon; Grassi-Oliveira, Rodrigo; Whittle, Nigel; Hüttenhofer, Alexander; Bredy, Timothy W; Singewald, Nicolas

2017-06-15

MicroRNA (miRNA)-mediated control of gene expression suggests that miRNAs are interesting targets and/or biomarkers in the treatment of anxiety- and trauma-related disorders, where often memory-associated gene expression is adversely affected. The role of miRNAs in the rescue of impaired fear extinction was assessed using the 129S1/SvlmJ (S1) mouse model of impaired fear extinction. miRNA microarray analysis, reverse transcription polymerase chain reaction, fluorescent in situ hybridization, lentiviral overexpression, and Luciferase reporter assays were used to gain insight into the mechanisms underlying miRNA-mediated normalization of deficient fear extinction. Rescuing impaired fear extinction via dietary zinc restriction was associated with differential expression of miRNAs in the amygdala. One candidate, miR-144-3p, robustly expressed in the basolateral amygdala, showed specific extinction-induced, but not fear-induced, increased expression in both extinction-rescued S1 mice and extinction-intact C57BL/6 (BL6) mice. miR-144-3p upregulation and effects on subsequent behavioral adaption was assessed in S1 and BL6 mice. miR-144-3p overexpression in the basolateral amygdala rescued impaired fear extinction in S1 mice, led to enhanced fear extinction acquisition in BL6 mice, and furthermore protected against fear renewal in BL6 mice. miR-144-3p targets a number of genes implicated in the control of plasticity-associated signaling cascades, including Pten, Spred1, and Notch1. In functional interaction studies, we revealed that the miR-144-3p target, PTEN, colocalized with miR-144-3p in the basolateral amygdala and showed functional downregulation following successful fear extinction in S1 mice. These findings identify a fundamental role of miR-144-3p in the rescue of impaired fear extinction and suggest this miRNA as a viable target in developing novel treatments for posttraumatic stress disorder and related disorders. Copyright © 2017 Society of Biological

Targeted Transgenic Overexpression of Mitochondrial Thymidine Kinase (TK2) Alters Mitochondrial DNA (mtDNA) and Mitochondrial Polypeptide Abundance : Transgenic TK2, mtDNA, and Antiretrovirals

OpenAIRE

Hosseini, Seyed H.; Kohler, James J.; Haase, Chad P.; Tioleco, Nina; Stuart, Tami; Keebaugh, Erin; Ludaway, Tomika; Russ, Rodney; Green, Elgin; Long, Robert; Wang, Liya; Eriksson, Staffan; Lewis, William

2007-01-01

Mitochondrial toxicity limits nucleoside reverse transcriptase inhibitors (NRTIs) for acquired immune deficiency syndrome. NRTI triphosphates, the active moieties, inhibit human immunodeficiency virus reverse transcriptase and eukaryotic mitochondrial DNA polymerase pol-γ. NRTI phosphorylation seems to correlate with mitochondrial toxicity, but experimental evidence is lacking. Transgenic mice (TGs) with cardiac overexpression of thymidine kinase isoforms (mitochondrial TK2 and cytoplasmic TK...

Overexpression of endothelin B receptor in glioblastoma: a prognostic marker and therapeutic target?

KAUST Repository

Vasaikar, Suhas

2018-02-06

BackgroundGlioblastoma (GBM) is the most common malignant brain tumor with median survival of 12-15 months. Owing to uncertainty in clinical outcome, additional prognostic marker(s) apart from existing markers are needed. Since overexpression of endothelin B receptor (ETBR) has been demonstrated in gliomas, we aimed to test whether ETBR is a useful prognostic marker in GBM and examine if the clinically available endothelin receptor antagonists (ERA) could be useful in the disease treatment.MethodsData from The Cancer Genome Atlas and the Gene Expression Omnibus database were analyzed to assess ETBR expression. For survival analysis, glioblastoma samples from 25 Swedish patients were immunostained for ETBR, and the findings were correlated with clinical history. The druggability of ETBR was assessed by protein-protein interaction network analysis. ERAs were analyzed for toxicity in in vitro assays with GBM and breast cancer cells.ResultsBy bioinformatics analysis, ETBR was found to be upregulated in glioblastoma patients, and its expression levels were correlated with reduced survival. ETBR interacts with key proteins involved in cancer pathogenesis, suggesting it as a druggable target. In vitro viability assays showed that ERAs may hold promise to treat glioblastoma and breast cancer.ConclusionsETBR is overexpressed in glioblastoma and other cancers and may be a prognostic marker in glioblastoma. ERAs may be useful for treating cancer patients.

Differential tumor biology effects of double-initiation in a mouse skin chemical carcinogenesis model comparing wild type versus protein kinase Cepsilon overexpression mice.

Science.gov (United States)

Li, Yafan; Wheeler, Deric L; Ananthaswamy, Honnavara N; Verma, Ajit K; Oberley, Terry D

2007-12-01

Our previous studies showed that protein kinase Cepsilon (PKCepsilon) verexpression in mouse skin resulted in metastatic squamous cell carcinoma (SCC) elicited by single 7,12-dimethylbenz(a)anthracene (DMBA)-initiation and 12-O-tetradecanoylphorbol-13-acetate (TPA)-promotion in the absence of preceding papilloma formation as is typically observed in wild type mice. The present study demonstrates that double-DMBA initiation modulates tumor incidence, multiplicity, and latency period in both wild type and PKCepsilon overexpression transgenic (PKCepsilon-Tg) mice. After 17 weeks (wks) of tumor promotion, a reduction in papilloma multiplicity was observed in double- versus single-DMBA initiated wild type mice. Papilloma multiplicity was inversely correlated with cell death indices of interfollicular keratinocytes, indicating decreased papilloma formation was caused by increased cell death and suggesting the origin of papillomas is in interfollicular epidermis. Double-initiated PKCepsilon-Tg mice had accelerated carcinoma formation and cancer incidence in comparison to single-initiated PKCepsilon-Tg mice. Morphologic analysis of mouse skin following double initiation and tumor promotion showed a similar if not identical series of events to those previously observed following single initiation and tumor promotion: putative preneoplastic cells were observed arising from hyperplastic hair follicles (HFs) with subsequent cancer cell infiltration into the dermis. Single-initiated PKCepsilon-Tg mice exhibited increased mitosis in epidermal cells of HFs during tumor promotion.

Epigenetic modification of miR-10a regulates renal damage by targeting CREB1 in type 2 diabetes mellitus.

Science.gov (United States)

Shan, Qun; Zheng, Guihong; Zhu, Aihua; Cao, Li; Lu, Jun; Wu, Dongmei; Zhang, ZiFeng; Fan, Shaohua; Sun, Chunhui; Hu, Bin; Zheng, Yuanlin

2016-09-01

Emerging evidence has shown that microRNA-mediated gene expression modulation plays a crucial role in the pathogenesis of type 2 diabetes mellitus, but the novel miRNAs involved in type 2 diabetes and its functional regulatory mechanisms still need to be determined. In this study, we assessed the role of miR-10a in extracellular matrix accumulation in the kidney of diabetic mellitus induced by combining administration of chronic high fat diet (HFD) and low dosage of streptozotocin (STZ, 35mg/kg). Here, we found that HFD/STZ administration decreased the level of microRNA (miR-10a) expression in ICR strain mice. Overexpression of miR-10a alleviated the increased ratio of urine albumin-to-creatinine (ACR) ratio of HFD/STZ mice. In contrast, knockdown of miR-10a increased the ratio of kidney ACR in naïve mice. Furthermore, cAMP response element binding protein 1 (CREB1) was validated as a target of miR-10a in vitro and in vivo. CREB1 and its downstream fibronectin (FN, extracellular matrix) were increased in HFD/STZ-treated mice, which was reversed by kidney miR-10a overexpression. The content of CREB1 and FN was increased by miR-10a knockdown in kidney of naïve mice. Furthermore, histone deacetylase 3 (HDAC3) was revealed to be increased in kidney of HFD/STZ mice, accompanied with the augmentation of ACR ratio and FN level. Knockdown of HDAC3 with siRNA significantly caused the increase of miR-10a, resulting in the decrease in CREB1 and FN expression in kidney of HFD/STZ mice. Contrarily, HDAC3 overexpression mediated by lentivirus decreased miR-10a content, and enhanced ACR value, CREB1 and FN formation in naïve mice. Collectively, these results elucidate that HDAC3/miR-10a/CREB1 serves as a new mechanism underlying kidney injury, providing potential therapeutic targets in type 2 diabetes. Copyright © 2016. Published by Elsevier Inc.

Antibody-mediated enzyme replacement therapy targeting both lysosomal and cytoplasmic glycogen in Pompe disease.

Science.gov (United States)

Yi, Haiqing; Sun, Tao; Armstrong, Dustin; Borneman, Scott; Yang, Chunyu; Austin, Stephanie; Kishnani, Priya S; Sun, Baodong

2017-05-01

Pompe disease is characterized by accumulation of both lysosomal and cytoplasmic glycogen primarily in skeletal and cardiac muscles. Mannose-6-phosphate receptor-mediated enzyme replacement therapy (ERT) with recombinant human acid α-glucosidase (rhGAA) targets the enzyme to lysosomes and thus is unable to digest cytoplasmic glycogen. Studies have shown that anti-DNA antibody 3E10 penetrates living cells and delivers "cargo" proteins to the cytosol or nucleus via equilibrative nucleoside transporter ENT2. We speculate that 3E10-mediated ERT with GAA will target both lysosomal and cytoplasmic glycogen in Pompe disease. A fusion protein (FabGAA) containing a humanized Fab fragment derived from the murine 3E10 antibody and the 110 kDa human GAA precursor was constructed and produced in CHO cells. Immunostaining with an anti-Fab antibody revealed that the Fab signals did not co-localize with the lysosomal marker LAMP2 in cultured L6 myoblasts or Pompe patient fibroblasts after incubation with FabGAA. Western blot with an anti-GAA antibody showed presence of the 150 kDa full-length FabGAA in the cell lysates, in addition to the 95- and 76 kDa processed forms of GAA that were also seen in the rhGAA-treated cells. Blocking of mannose-6-phosphate receptor with mannose-6-phosphate markedly reduced the 95- and the 76 kDa forms but not the 150 kDa form. In GAA-KO mice, FabGAA achieved similar treatment efficacy as rhGAA at an equal molar dose in reducing tissue glycogen contents. Our data suggest that FabGAA retains the ability of rhGAA to treat lysosomal glycogen accumulation and has the beneficial potential over rhGAA to reduce cytoplasmic glycogen storage in Pompe disease. FabGAA can be delivered to both the cytoplasm and lysosomes in cultured cells. FabGAA equally reduced lysosomal glycogen accumulation as rhGAA in GAA-KO mice. FabGAA has the beneficial potential over rhGAA to clear cytoplasmic glycogen. This study suggests a novel antibody-enzyme fusion protein therapy

Overexpression of miR-19b Impairs Cardiac Development in Zebrafish by Targeting ctnnb1

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Mengmeng Li

2014-07-01

Full Text Available Background: MicroRNAs are broadly accepted as crucial regulators of cardiovascular development, and dysregulation of their expression has been linked to cardiac disease. MicroRNA cluster miR-17-92 has been implicated in cardiac development and function, yet its defined mechanisms of action in this context are uncertain. Here, we focused on miR-19b, a key component of the miR-17-92 cluster proven to induce cardiomyocyte proliferation in vitro. We aimed to identify the biological significance of miR-19b in cardiac development and its underlying molecular mechanism of action in vivo. Methods: We micro-injected zebrafish embryos with different concentrations (0, 2, 4 and 8 μm of miR-19b mimics or a negative control, and assessed the embryo malformation rate, mortality rate, hatching rate and heart abnormalities at 72 hours post-fertilization (72 hpf. Results: We found that overexpression of miR-19b impacted left-right symmetry and cardiac development of zebrafish embryos, characterized by pericardial edema, slower heart rate and cardiac looping defects in a dose-dependent manner. Moreover, several important signaling molecules in the Wnt signaling pathway were abnormally expressed, suggesting that overexpression of miR-19b induces the inhibition of the Wnt signaling pathway by directly targeting ctnnb1. Interestingly, the deformed cardiac phenotype was partially rescued by treatment with the GSK3β inhibitor lithium chloride. Conclusion: Our findings suggest that miR-19b regulates laterality development and heart looping in zebrafish embryos by targeting ctnnb1.

Cardiomyocyte Overexpression of FABP4 Aggravates Pressure Overload-Induced Heart Hypertrophy.

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Ji Zhang

Full Text Available Fatty acid binding protein 4 (FABP4 is a member of the intracellular lipid-binding protein family, responsible for the transportation of fatty acids. It is considered to express mainly in adipose tissues, and be strongly associated with inflammation, obesity, diabetes and cardiovasculardiseases. Here we report that FABP4 is also expressed in cardiomyocytes and plays an important role in regulating heart function under pressure overload. We generated heart-specific transgenic FABP4 (FABP4-TG mice using α myosin-heavy chain (α-MHC promoter and human FABP4 sequence, resulting in over-expression of FABP4 in cardiomyocytes. The FABP4-TG mice displayed normal cardiac morphology and contractile function. When they were subjected to the transverse aorta constriction (TAC procedure, the FABP4-TG mice developed more cardiac hypertrophy correlated with significantly increased ERK phosphorylation, compared with wild type controls. FABP4 over-expression in cardiomyocytes activated phosphor-ERK signal and up-regulate the expression of cardiac hypertrophic marker genes. Conversely, FABP4 induced phosphor-ERK signal and hypertrophic gene expressions can be markedly inhibited by an ERK inhibitor PD098059 as well as the FABP4 inhibitor BMS309403. These results suggest that FABP4 over-expression in cardiomyocytes can aggravate the development of cardiac hypertrophy through the activation of ERK signal pathway.

A dual selection based, targeted gene replacement tool for Magnaporthe grisea and Fusarium oxysporum.

Science.gov (United States)

Khang, Chang Hyun; Park, Sook-Young; Lee, Yong-Hwan; Kang, Seogchan

2005-06-01

Rapid progress in fungal genome sequencing presents many new opportunities for functional genomic analysis of fungal biology through the systematic mutagenesis of the genes identified through sequencing. However, the lack of efficient tools for targeted gene replacement is a limiting factor for fungal functional genomics, as it often necessitates the screening of a large number of transformants to identify the desired mutant. We developed an efficient method of gene replacement and evaluated factors affecting the efficiency of this method using two plant pathogenic fungi, Magnaporthe grisea and Fusarium oxysporum. This method is based on Agrobacterium tumefaciens-mediated transformation with a mutant allele of the target gene flanked by the herpes simplex virus thymidine kinase (HSVtk) gene as a conditional negative selection marker against ectopic transformants. The HSVtk gene product converts 5-fluoro-2'-deoxyuridine to a compound toxic to diverse fungi. Because ectopic transformants express HSVtk, while gene replacement mutants lack HSVtk, growing transformants on a medium amended with 5-fluoro-2'-deoxyuridine facilitates the identification of targeted mutants by counter-selecting against ectopic transformants. In addition to M. grisea and F. oxysporum, the method and associated vectors are likely to be applicable to manipulating genes in a broad spectrum of fungi, thus potentially serving as an efficient, universal functional genomic tool for harnessing the growing body of fungal genome sequence data to study fungal biology.

Overexpression of Heparin-Binding Epidermal Growth Factor-Like Growth Factor Mediates Liver Fibrosis in Transgenic Mice.

Science.gov (United States)

Guo, Yongze; Ding, Qian; Chen, Lei; Ji, Chenguang; Hao, Huiyao; Wang, Jia; Qi, Wei; Xie, Xiaoli; Ma, Junji; Li, Aidi; Jiang, Xiaoyu; Li, Xiaotian; Jiang, Huiqing

2017-08-01

The role of heparin-binding epidermal growth factor-like growth factor (HB-EGF) in liver fibrosis is not clear and is sometimes even contradictory. To clarify this role, a HB-EGF transgenic (Tg) mouse model was, for the first time, used to evaluate the functions of HB-EGF in liver fibrosis. For the in vivo study, carbon tetrachloride injection and bile duct ligation treatment were used to induce liver fibrosis in HB-EGF Tg mice and wild-type (WT) mice, respectively. Primary hepatic satellite cells (HSCs) were isolated from HB-EGF Tg and WT mice for the in vitro study. Compared with the WT mice, HB-EGF Tg mice were shown to develop more severe liver fibrosis when treated with carbon tetrachloride or bile duct ligation, with increased matrix metalloproteinases 13 activity and enhanced expression of fibrogenic genes including α-smooth muscle actin and collagen I. HB-EGF gene transfer led to an increase in proliferation and a decrease in apoptosis in primary HSCs. The ERK signaling pathway was more highly activated in primary HSCs from HB-EGF Tg mice than in those from WT mice. Our investigation confirmed the profibrotic effect of HB-EGF on the liver using a Tg mouse model. This result may contribute to the elucidation of HB-EGF as a therapeutic target in liver fibrosis. Copyright © 2017 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.

MMP20 Overexpression Disrupts Molar Ameloblast Polarity and Migration.

Science.gov (United States)

Shin, M; Chavez, M B; Ikeda, A; Foster, B L; Bartlett, J D

2018-02-01

Ameloblasts responsible for enamel formation express matrix metalloproteinase 20 (MMP20), an enzyme that cleaves enamel matrix proteins, including amelogenin (AMELX) and ameloblastin (AMBN). Previously, we showed that continuously erupting incisors from transgenic mice overexpressing active MMP20 had a massive cell infiltrate present within their enamel space, leading to enamel mineralization defects. However, effects of MMP20 overexpression on mouse molars were not analyzed, although these teeth more accurately represent human odontogenesis. Therefore, MMP20-overexpressing mice ( Mmp20 +/+ Tg + ) were assessed by multiscale analyses, combining several approaches from high-resolution micro-computed tomography to enamel organ immunoblots. During the secretory stage at postnatal day 6 (P6), Mmp20 +/+ Tg + mice had a discontinuous ameloblast layer and, unlike incisors, molar P12 maturation stage ameloblasts abnormally migrated away from the enamel layer into the stratum intermedium/stellate reticulum. TOPflash assays performed in vitro demonstrated that MMP20 expression promoted β-catenin nuclear localization and that MMP20 expression promoted invasion through Matrigel-coated filters. However, for both assays, significant differences were eliminated in the presence of the β-catenin inhibitor ICG-001. This suggests that MMP20 activity promotes cell migration via the Wnt pathway. In vivo, the unique molar migration of amelogenin-expressing ameloblasts was associated with abnormal deposition of ectopic calcified nodules surrounding the adherent enamel layer. Enamel content was assessed just prior to eruption at P15. Compared to wild-type, Mmp20 +/+ Tg + molars exhibited significant reductions in enamel thickness (70%), volume (60%), and mineral density (40%), and MMP20 overexpression resulted in premature cleavage of AMBN, which likely contributed to the severe defects in enamel mineralization. In addition, Mmp20 +/+ Tg + mouse molar enamel organs had increased levels

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

International Nuclear Information System (INIS)

Wu, Hsu-Pin; Hsu, Shu-Yuan; Wu, Wen-Ai; Hu, Ji-Wei; Ouyang, Pin

2014-01-01

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 +/− 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

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

Energy Technology Data Exchange (ETDEWEB)

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.

Gene therapy/bone marrow transplantation in ADA-deficient mice: roles of enzyme-replacement therapy and cytoreduction.

Science.gov (United States)

Carbonaro, Denise A; Jin, Xiangyang; Wang, Xingchao; Yu, Xiao-Jin; Rozengurt, Nora; Kaufman, Michael L; Wang, Xiaoyan; Gjertson, David; Zhou, Yang; Blackburn, Michael R; Kohn, Donald B

2012-11-01

Gene therapy (GT) for adenosine deaminase-deficient severe combined immune deficiency (ADA-SCID) can provide significant long-term benefit when patients are given nonmyeloablative conditioning and ADA enzyme-replacement therapy (ERT) is withheld before autologous transplantation of γ-retroviral vector-transduced BM CD34+ cells. To determine the contributions of conditioning and discontinuation of ERT to the therapeutic effects, we analyzed these factors in Ada gene knockout mice (Ada(-/-)). Mice were transplanted with ADA-deficient marrow transduced with an ADA-expressing γ-retroviral vector without preconditioning or after 200 cGy or 900 cGy total-body irradiation and evaluated after 4 months. In all tissues analyzed, vector copy numbers (VCNs) were 100- to 1000-fold greater in mice receiving 900 cGy compared with 200 cGy (P < .05). In mice receiving 200 cGy, VCN was similar whether ERT was stopped or given for 1 or 4 months after GT. In unconditioned mice, there was decreased survival with and without ERT, and VCN was very low to undetectable. When recipients were conditioned with 200 cGy and received transduced lineage-depleted marrow, only recipients receiving ERT (1 or 4 months) had detectable vector sequences in thymocytes. In conclusion, cytoreduction is important for the engraftment of gene-transduced HSC, and short-term ERT after GT did not diminish the capacity of gene-corrected cells to engraft and persist.

Dimethylarginine Dimethylaminohydrolase Overexpression enhances Insulin Sensitivity

Science.gov (United States)

Sydow, Karsten; Mondon, Carl E.; Schrader, Joerg; Konishi, Hakuoh; Cooke, John P.

2011-01-01

Objective Previous studies suggest that nitric oxide (NO) may modulate insulin-induced uptake of glucose in insulin-sensitive tissues. Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of NO synthase (NOS). We hypothesized that a reduction in endogenous ADMA would increase NO synthesis and thereby enhance insulin sensitivity. Methods and Results To test this hypothesis we employed a transgenic mouse in which we overexpressed human dimethylarginine dimethylaminohydrolase (DDAH-I). The DDAH-I mice had lower plasma ADMA at all ages (22–70 weeks) by comparison to wild-type (WT) littermates. With a glucose challenge, WT mice showed a prompt increase in ADMA, whereas DDAH-I mice had a blunted response. Furthermore, DDAH-I mice had a blunted increase in plasma insulin and glucose levels after glucose challenge, with a 50% reduction in the insulin resistence index, consistent with enhanced sensitivity to insulin. In liver, we observed an increased Akt phosphorylation in the DDAH-I mice after i.p. glucose challenge. Incubation of skeletal muscle from WT mice ex vivo with ADMA (2μM) markedly suppressed insulin-induced glycogen synthesis in fast-twitch but not slow-twitch muscle. Conclusions These findings suggest that the endogenous NOS inhibitor ADMA reduces insulin sensitivity, consistent with previous observations that NO plays a role in insulin sensitivity. PMID:18239148

PKCδ regulates hepatic insulin sensitivity and hepatosteatosis in mice and humans

DEFF Research Database (Denmark)

Bezy, Olivier; Tran, Thien T; Pihlajamäki, Jussi

2011-01-01

C57BL/6J and 129S6/Sv (B6 and 129) mice differ dramatically in their susceptibility to developing diabetes in response to diet- or genetically induced insulin resistance. A major locus contributing to this difference has been mapped to a region on mouse chromosome 14 that contains the gene encoding...... tolerance, and reduced hepatosteatosis with aging. Conversely, mice with liver-specific overexpression of PKCδ developed hepatic insulin resistance characterized by decreased insulin signaling, enhanced lipogenic gene expression, and hepatosteatosis. Therefore, changes in the expression and regulation...... of PKCδ between strains of mice and in obese humans play an important role in the genetic risk of hepatic insulin resistance, glucose intolerance, and hepatosteatosis; and thus PKCδ may be a potential target in the treatment of metabolic syndrome....

Overexpression of SIRT1 in mouse forebrain impairs lipid/glucose metabolism and motor function.

Directory of Open Access Journals (Sweden)

Dongmei Wu

Full Text Available SIRT1 plays crucial roles in glucose and lipid metabolism, and has various functions in different tissues including brain. The brain-specific SIRT1 knockout mice display defects in somatotropic signaling, memory and synaptic plasticity. And the female mice without SIRT1 in POMC neuron are more sensitive to diet-induced obesity. Here we created transgenic mice overexpressing SIRT1 in striatum and hippocampus under the control of CaMKIIα promoter. These mice, especially females, exhibited increased fat accumulation accompanied by significant upregulation of adipogenic genes in white adipose tissue. Glucose tolerance of the mice was also impaired with decreased Glut4 mRNA levels in muscle. Moreover, the SIRT1 overexpressing mice showed decreased energy expenditure, and concomitantly mitochondria-related genes were decreased in muscle. In addition, these mice showed unusual spontaneous physical activity pattern, decreased activity in open field and rotarod performance. Further studies demonstrated that SIRT1 deacetylated IRS-2, and upregulated phosphorylation level of IRS-2 and ERK1/2 in striatum. Meanwhile, the neurotransmitter signaling in striatum and the expression of endocrine hormones in hypothalamus and serum T3, T4 levels were altered. Taken together, our findings demonstrate that SIRT1 in forebrain regulates lipid/glucose metabolism and motor function.

Activated signature of antiphospholipid syndrome neutrophils reveals potential therapeutic target

Science.gov (United States)

Knight, Jason S.; Meng, He; Coit, Patrick; Yalavarthi, Srilakshmi; Sule, Gautam; Gandhi, Alex A.; Grenn, Robert C.; Mazza, Levi F.; Ali, Ramadan A.; Renauer, Paul; Wren, Jonathan D.; Bockenstedt, Paula L.; Wang, Hui; Eitzman, Daniel T.; Sawalha, Amr H.

2017-01-01

Antiphospholipid antibodies, present in one-third of lupus patients, increase the risk of thrombosis. We recently reported a key role for neutrophils — neutrophil extracellular traps (NETs), in particular — in the thrombotic events that define antiphospholipid syndrome (APS). To further elucidate the role of neutrophils in APS, we performed a comprehensive transcriptome analysis of neutrophils isolated from patients with primary APS. Moreover, APS-associated venous thrombosis was modeled by treating mice with IgG prepared from APS patients, followed by partial restriction of blood flow through the inferior vena cava. In patients, APS neutrophils demonstrated a proinflammatory signature with overexpression of genes relevant to IFN signaling, cellular defense, and intercellular adhesion. For in vivo studies, we focused on P-selectin glycoprotein ligand-1 (PSGL-1), a key adhesion molecule overexpressed in APS neutrophils. The introduction of APS IgG (as compared with control IgG) markedly potentiated thrombosis in WT mice, but not PSGL-1–KOs. PSGL-1 deficiency was also associated with reduced leukocyte vessel wall adhesion and NET formation. The thrombosis phenotype was restored in PSGL-1–deficient mice by infusion of WT neutrophils, while an anti–PSGL-1 monoclonal antibody inhibited APS IgG–mediated thrombosis in WT mice. PSGL-1 represents a potential therapeutic target in APS. PMID:28931754

Over-expression of Stat5b confers protection against diabetes in the non-obese diabetic (NOD) mice via up-regulation of CD4{sup +}CD25{sup +} regulatory T cells

Energy Technology Data Exchange (ETDEWEB)

Jin, Yulan; Purohit, Sharad [Center for Biotechnology and Genomic Medicine, Georgia Health Sciences University, GA (United States); Department of Pathology, Medical College of Georgia, Georgia Health Sciences University, GA (United States); Chen, Xueqin; Yi, Bing [Center for Biotechnology and Genomic Medicine, Georgia Health Sciences University, GA (United States); She, Jin-Xiong, E-mail: jshe@georgiahealth.edu [Center for Biotechnology and Genomic Medicine, Georgia Health Sciences University, GA (United States); Department of Pathology, Medical College of Georgia, Georgia Health Sciences University, GA (United States)

2012-08-10

Highlights: Black-Right-Pointing-Pointer This is the first study to provide direct evidence of the role of Stat5b in NOD mice. Black-Right-Pointing-Pointer Over-expression of wild type Stat5b transgene protects NOD mice against diabetes. Black-Right-Pointing-Pointer This protection may be mediated by the up-regulation of CD4{sup +}CD25{sup +} Tregs. -- Abstract: The signal transducers and activators of transcription (STAT) family of proteins play a critical role in cytokine signaling required for fine tuning of immune regulation. Previous reports showed that a mutation (L327M) in the Stat5b protein leads to aberrant cytokine signaling in the NOD mice. To further elaborate the role of Stat5b in diabetes, we established a NOD transgenic mouse that over-expresses the wild type Stat5b gene. The incidences of spontaneous diabetes as well as cyclophosphamide-induced diabetes were significantly reduced and delayed in the Stat5b transgenic NOD mice compared to their littermate controls. The total cell numbers of CD4{sup +} T cells and especially CD8{sup +} T cells in the spleen and pancreatic lymph node were increased in the Stat5b transgenic NOD mice. Consistent with these findings, CD4{sup +} and CD8{sup +} T cells from the Stat5b transgenic NOD mice showed a higher proliferation capacity and up-regulation of multiple cytokines including IL-2, IFN-{gamma}, TNF-{alpha} and IL-10 as well as anti-apoptotic gene Bcl-xl. Furthermore, the number and proportion of CD4{sup +}CD25{sup +} regulatory T cells were significantly increased in transgenic mice although in vitro suppression ability of the regulatory T-cells was not affected by the transgene. Our results suggest that Stat5b confers protection against diabetes in the NOD mice by regulating the numbers and function of multiple immune cell types, especially by up-regulating CD4{sup +}CD25{sup +} regulatory T cells.

VIP Gene Deletion in Mice Causes Cardiomyopathy Associated with Upregulation of Heart Failure Genes

Energy Technology Data Exchange (ETDEWEB)

Szema, Anthony M.; Hamidi, Sayyed A.; Smith, S. David; Benveniste, Helene; Katare, Rajesh Gopalrao

2013-05-20

Vasoactive Intestinal Peptide (VIP), a pulmonary vasodilator and inhibitor of vascular smooth muscle proliferation, is absent in pulmonary arteries of patients with idiopathic pulmonary arterial hypertension (PAH). We previously determined that targeted deletion of the VIP gene in mice leads to PAH with pulmonary vascular remodeling and right ventricular (RV) dilatation. Whether the left ventricle is also affected by VIP gene deletion is unknown. In the current study, we examined if VIP knockout mice (VIP-/-) develop both right (RV) and left ventricular (LV) cardiomyopathy, manifested by LV dilatation and systolic dysfunction, as well as overexpression of genes conducive to heart failure.

Overexpression of Rad in muscle worsens diet-induced insulin resistance and glucose intolerance and lowers plasma triglyceride level

Science.gov (United States)

Ilany, Jacob; Bilan, Philip J.; Kapur, Sonia; Caldwell, James S.; Patti, Mary-Elizabeth; Marette, Andre; Kahn, C. Ronald

2006-03-01

Rad is a low molecular weight GTPase that is overexpressed in skeletal muscle of some patients with type 2 diabetes mellitus and/or obesity. Overexpression of Rad in adipocytes and muscle cells in culture results in diminished insulin-stimulated glucose uptake. To further elucidate the potential role of Rad in vivo, we have generated transgenic (tg) mice that overexpress Rad in muscle using the muscle creatine kinase (MCK) promoter-enhancer. Rad tg mice have a 6- to 12-fold increase in Rad expression in muscle as compared to wild-type littermates. Rad tg mice grow normally and have normal glucose tolerance and insulin sensitivity, but have reduced plasma triglyceride levels. On a high-fat diet, Rad tg mice develop more severe glucose intolerance than the wild-type mice; this is due to increased insulin resistance in muscle, as exemplified by a rightward shift in the dose-response curve for insulin stimulated 2-deoxyglucose uptake. There is also a unexpected further reduction of the plasma triglyceride levels that is associated with increased levels of lipoprotein lipase in the Rad tg mice. These results demonstrate a potential synergistic interaction between increased expression of Rad and high-fat diet in creation of insulin resistance and altered lipid metabolism present in type 2 diabetes. diabetes mellitus | glucose transport | RGK GTPase | transgenic mouse

Intraperitoneal implant of recombinant encapsulated cells overexpressing alpha-L-iduronidase partially corrects visceral pathology in mucopolysaccharidosis type I mice.

Science.gov (United States)

Baldo, Guilherme; Mayer, Fabiana Quoos; Martinelli, Barbara; Meyer, Fabiola Schons; Burin, Maira; Meurer, Luise; Tavares, Angela Maria Vicente; Giugliani, Roberto; Matte, Ursula

2012-08-01

Mucopolysaccharidosis type I (MPS I) is characterized by deficiency of the enzyme alpha-L-iduronidase (IDUA) and storage of glycosaminoglycans (GAG) in several tissues. Current available treatments present limitations, thus the search for new therapies. Encapsulation of recombinant cells within polymeric structures combines gene and cell therapy and is a promising approach for treating MPS I. We produced alginate microcapsules containing baby hamster kidney (BHK) cells overexpressing IDUA and implanted these capsules in the peritoneum of MPS I mice. An increase in serum and tissue IDUA activity was observed at early time-points, as well as a reduction in GAG storage; however, correction in the long term was only partially achieved, with a drop in the IDUA activity being observed a few weeks after the implant. Analysis of the capsules obtained from the peritoneum revealed inflammation and a pericapsular fibrotic process, which could be responsible for the reduction in IDUA levels observed in the long term. In addition, treated mice developed antibodies against the enzyme. The results suggest that the encapsulation process is effective in the short term but improvements must be achieved in order to reduce the immune response and reach a stable correction.

Cardiac-specific overexpression of catalase prevents diabetes-induced pathological changes by inhibiting NF-κB signaling activation in the heart.

Science.gov (United States)

Cong, Weitao; Ruan, Dandan; Xuan, Yuanhu; Niu, Chao; Tao, Youli; Wang, Yang; Zhan, Kungao; Cai, Lu; Jin, Litai; Tan, Yi

2015-12-01

Catalase is an antioxidant enzyme that specifically catabolizes hydrogen peroxide (H2O2). Overexpression of catalase via a heart-specific promoter (CAT-TG) was reported to reduce diabetes-induced accumulation of reactive oxygen species (ROS) and further prevent diabetes-induced pathological abnormalities, including cardiac structural derangement and left ventricular abnormity in mice. However, the mechanism by which catalase overexpression protects heart function remains unclear. This study found that activation of a ROS-dependent NF-κB signaling pathway was downregulated in hearts of diabetic mice overexpressing catalase. In addition, catalase overexpression inhibited the significant increase in nitration levels of key enzymes involved in energy metabolism, including α-oxoglutarate dehydrogenase E1 component (α-KGD) and ATP synthase α and β subunits (ATP-α and ATP-β). To assess the effects of the NF-κB pathway activation on heart function, Bay11-7082, an inhibitor of the NF-κB signaling pathway, was injected into diabetic mice, protecting mice against the development of cardiac damage and increased nitrative modifications of key enzymes involved in energy metabolism. In conclusion, these findings demonstrated that catalase protects mouse hearts against diabetic cardiomyopathy, partially by suppressing NF-κB-dependent inflammatory responses and associated protein nitration. Copyright © 2015 Elsevier Ltd. All rights reserved.

Overexpression of dimethylarginine dimethylaminohydrolase 1 attenuates airway inflammation in a mouse model of asthma.

Directory of Open Access Journals (Sweden)

Kayla G Kinker

Full Text Available Levels of asymmetric dimethylarginine (ADMA, an endogenous inhibitor of nitric oxide synthase, are increased in lung, sputum, exhaled breath condensate and plasma samples from asthma patients. ADMA is metabolized primarily by dimethylarginine dimethylaminohydrolase 1 (DDAH1 and DDAH2. We determined the effect of DDAH1 overexpression on development of allergic inflammation in a mouse model of asthma. The expression of DDAH1 and DDAH2 in mouse lungs was determined by RT-quantitative PCR (qPCR. ADMA levels in bronchoalveolar lavage fluid (BALF and serum samples were determined by mass spectrometry. Wild type and DDAH1-transgenic mice were intratracheally challenged with PBS or house dust mite (HDM. Airway inflammation was assessed by bronchoalveolar lavage (BAL total and differential cell counts. The levels of IgE and IgG1 in BALF and serum samples were determined by ELISA. Gene expression in lungs was determined by RNA-Seq and RT-qPCR. Our data showed that the expression of DDAH1 and DDAH2 was decreased in the lungs of mice following HDM exposure, which correlated with increased ADMA levels in BALF and serum. Transgenic overexpression of DDAH1 resulted in decreased BAL total cell and eosinophil numbers following HDM exposure. Total IgE levels in BALF and serum were decreased in HDM-exposed DDAH1-transgenic mice compared to HDM-exposed wild type mice. RNA-Seq results showed downregulation of genes in the inducible nitric oxide synthase (iNOS signaling pathway in PBS-treated DDAH1-transgenic mice versus PBS-treated wild type mice and downregulation of genes in IL-13/FOXA2 signaling pathway in HDM-treated DDAH1-transgenic mice versus HDM-treated wild type mice. Our findings suggest that decreased expression of DDAH1 and DDAH2 in the lungs may contribute to allergic asthma and overexpression of DDAH1 attenuates allergen-induced airway inflammation through modulation of Th2 responses.

Neural androgen receptors affect the number of surviving new neurones in the adult dentate gyrus of male mice.

Science.gov (United States)

Swift-Gallant, A; Duarte-Guterman, P; Hamson, D K; Ibrahim, M; Monks, D A; Galea, L A M

2018-04-01

Adult hippocampal neurogenesis occurs in many mammalian species. In rats, the survival of new neurones within the hippocampus is modulated by the action of androgen via the androgen receptor (AR); however, it is not known whether this holds true in mice. Furthermore, the evidence is mixed regarding whether androgens act in neural tissue or via peripheral non-neural targets to promote new neurone survival in the hippocampus. We evaluated whether the action of androgen via AR underlies the survival of new neurones in mice, and investigated whether increasing AR selectively in neural tissue would increase new neurone survival in the hippocampus. We used the cre-loxP system to overexpress AR only in neural tissues (Nestin-AR). These males were compared with wild-type males, as well as control males with 1 of the 2 mutations required for overexpression. Mice were gonadectomised and injected with the DNA synthesis marker, bromodeoxyuridine (BrdU) and for 37 days (following BrdU injection), mice were treated with oil or dihydrotestosterone (DHT). Using immunohistochemistry, proliferation (Ki67) and survival (BrdU) of new neurones were both evaluated in the dorsal and ventral dentate gyrus. Dihydrotestosterone treatment increased the survival of new neurones in the entire hippocampus in wild-type mice and control mice that only have 1 of 2 necessary mutations for transgenic expression. However, DHT treatment did not increase the survival of new neurones in mice that overexpressed AR in neural tissue. Cell proliferation (Ki67) and cell death (pyknotic cells) were not affected by DHT treatment in wild-type or transgenic males. These results suggest that androgens act via neural AR to affect hippocampal neurogenesis by promoting cell survival; however, the relationship between androgen dose and new neurone survival is nonlinear. © 2018 British Society for Neuroendocrinology.

Targeting EGFR-overexpressing tumor cells using Cetuximab-immunomicelles loaded with doxorubicin and superparamagnetic iron oxide

International Nuclear Information System (INIS)

Liao Chengde; Sun Qiquan; Liang, Biling; Shen Jun; Shuai Xintao

2011-01-01

Epidermal growth factor receptor (EGFR), a cellular transmembrane receptor, plays a key role in cell proliferation and is linked to a poor prognosis in various human cancers. In this study, we constructed Cetuximab-immunomicelles in which the anti-EGFR monoclonal antibody was linked to poly(ethylene glycol)-block-poly(ε-caprolactone) (PEG–PCL) nanomicelles that were loaded with doxorubicin (DOX) and superparamagnetic iron oxide (SPIO). The specific interactions between EGFR-overexpressing tumor cells (A431) and immunomicelles were observed using confocal laser scanning microscopy (CLSM) and flow cytometry. Furthermore, the capacity of transporting SPIO into tumor cells using these immunomicelles was evaluated with a 1.5 T clinical magnetic resonance imaging (MRI) scanner. It was found that the acquired MRI T2 signal intensity of A431 cells that were treated with the SPIO-loaded and antibody-functionalized micelles decreased significantly. Using the thiazolyl blue tetrazolium bromide (MTT) assay, we also demonstrated that the immunomicelles inhibited cell proliferation more effectively than their nontargeting counterparts. Our results suggest that Cetuximab-immunomicelles are a useful delivery vehicle for DOX and SPIO to EGFR-overexpressing tumor cells in vitro and that Cetuximab-immunomicelles can serve as a MRI-visible and targeted drug delivery agent for better tumor imaging and therapy.

Anxiolytic-like effects after vector-mediated overexpression of neuropeptide Y in the amygdala and hippocampus of mice

DEFF Research Database (Denmark)

Christiansen, Søren Hofman Oliveira; Olesen, Mikkel Vestergaard; Gøtzsche, Casper René

2014-01-01

, injections of rAAV-NPY caused significant anxiolytic-like effect in the open field, elevated plus maze, and light-dark transition tests. In the hippocampus, rAAV-NPY treatment was associated with anxiolytic-like effect only in the elevated plus maze. No additive effect was observed after combined r....... Using a recombinant adeno-associated viral (rAAV) vector, we addressed this idea by testing effects on anxiolytic- and depression-like behaviours in adult mice after overexpression of NPY transgene in the amygdala and/or hippocampus, two brain regions implicated in emotional behaviours. In the amygdala......AAV-NPY injection into both the amygdala and hippocampus where anxiolytic-like effect was found in the elevated plus maze and light-dark transition tests. Antidepressant-like effects were not detected in any of the rAAV-NPY injected groups. Immobility was even increased in the tail suspension and forced swim tests...

Gene therapy/bone marrow transplantation in ADA-deficient mice: roles of enzyme-replacement therapy and cytoreduction

Science.gov (United States)

Jin, Xiangyang; Wang, Xingchao; Yu, Xiao-Jin; Rozengurt, Nora; Kaufman, Michael L.; Wang, Xiaoyan; Gjertson, David; Zhou, Yang; Blackburn, Michael R.; Kohn, Donald B.

2012-01-01

Gene therapy (GT) for adenosine deaminase–deficient severe combined immune deficiency (ADA-SCID) can provide significant long-term benefit when patients are given nonmyeloablative conditioning and ADA enzyme-replacement therapy (ERT) is withheld before autologous transplantation of γ-retroviral vector-transduced BM CD34+ cells. To determine the contributions of conditioning and discontinuation of ERT to the therapeutic effects, we analyzed these factors in Ada gene knockout mice (Ada−/−). Mice were transplanted with ADA-deficient marrow transduced with an ADA-expressing γ-retroviral vector without preconditioning or after 200 cGy or 900 cGy total-body irradiation and evaluated after 4 months. In all tissues analyzed, vector copy numbers (VCNs) were 100- to 1000-fold greater in mice receiving 900 cGy compared with 200 cGy (P < .05). In mice receiving 200 cGy, VCN was similar whether ERT was stopped or given for 1 or 4 months after GT. In unconditioned mice, there was decreased survival with and without ERT, and VCN was very low to undetectable. When recipients were conditioned with 200 cGy and received transduced lineage-depleted marrow, only recipients receiving ERT (1 or 4 months) had detectable vector sequences in thymocytes. In conclusion, cytoreduction is important for the engraftment of gene-transduced HSC, and short-term ERT after GT did not diminish the capacity of gene-corrected cells to engraft and persist. PMID:22833548

Reactive oxygen species and fatigue-induced prolonged low-frequency force depression in skeletal muscle fibres of rats, mice and SOD2 overexpressing mice.

Science.gov (United States)

Bruton, Joseph D; Place, Nicolas; Yamada, Takashi; Silva, José P; Andrade, Francisco H; Dahlstedt, Anders J; Zhang, Shi-Jin; Katz, Abram; Larsson, Nils-Göran; Westerblad, Håkan

2008-01-01

Skeletal muscle often shows a delayed force recovery after fatiguing stimulation, especially at low stimulation frequencies. In this study we focus on the role of reactive oxygen species (ROS) in this fatigue-induced prolonged low-frequency force depression. Intact, single muscle fibres were dissected from flexor digitorum brevis (FDB) muscles of rats and wild-type and superoxide dismutase 2 (SOD2) overexpressing mice. Force and myoplasmic free [Ca(2+)] ([Ca(2+)](i)) were measured. Fibres were stimulated at different frequencies before and 30 min after fatigue induced by repeated tetani. The results show a marked force decrease at low stimulation frequencies 30 min after fatiguing stimulation in all fibres. This decrease was associated with reduced tetanic [Ca(2+)](i) in wild-type mouse fibres, whereas rat fibres and mouse SOD2 overexpressing fibres instead displayed a decreased myofibrillar Ca(2+) sensitivity. The SOD activity was approximately 50% lower in wild-type mouse than in rat FDB muscles. Myoplasmic ROS increased during repeated tetanic stimulation in rat fibres but not in wild-type mouse fibres. The decreased Ca(2+) sensitivity in rat fibres could be partially reversed by application of the reducing agent dithiothreitol, whereas the decrease in tetanic [Ca(2+)](i) in wild-type mouse fibres was not affected by dithiothreitol or the antioxidant N-acetylcysteine. In conclusion, we describe two different causes of fatigue-induced prolonged low-frequency force depression, which correlate to differences in SOD activity and ROS metabolism. These findings may have clinical implications since ROS-mediated impairments in myofibrillar function can be counteracted by reductants and antioxidants, whereas changes in SR Ca(2+) handling appear more resistant to interventions.

Overexpression of FurA in Anabaena sp. PCC 7120 reveals new targets for this regulator involved in photosynthesis, iron uptake and cellular morphology.

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González, Andrés; Bes, M Teresa; Barja, François; Peleato, M Luisa; Fillat, María F

2010-11-01

Previous genomic analyses of the filamentous nitrogen-fixing cyanobacterium Anabaena sp. PCC 7120 have identified three ferric uptake regulator (Fur) homologs with low sequence identities and probably different functions in the cell. FurA is a constitutive protein that shares the highest homology with Fur from heterotrophic bacteria and appears to be essential for in vitro growth. In this study, we have analysed the effects of FurA overexpression on the Anabaena sp. phenotype and investigated which of the observed alterations were directly operated by FurA. Overexpression of the regulator led to changes in cellular morphology, resulting in shorter filaments with rounded cells of different sizes. The furA-overexpressing strain showed a slower photoautotrophic growth and a marked decrease in the oxygen evolution rate. Overexpression of the regulator also decreased both catalase and superoxide dismutase activities, but did not lead to an increase in the levels of intracellular reactive oxygen species. By combining phenotypic studies, reverse transcription-PCR analyses and electrophoretic mobility shift assays, we identified three novel direct targets of FurA, including genes encoding a siderophore outer membrane transporter (schT), bacterial actins (mreBCD) and the PSII reaction center protein D1 (psbA). The affinity of FurA for these novel targets was markedly affected by the absence of divalent metal ions, confirming previous evidence of a critical role for the metal co-repressor in the function of the regulator in vivo. The results unravel new cellular processes modulated by FurA, supporting its role as a global transcriptional regulator in Anabaena sp. PCC 7120.

Specific and Efficient Regression of Cancers Harboring KRAS Mutation by Targeted RNA Replacement.

Science.gov (United States)

Kim, Sung Jin; Kim, Ju Hyun; Yang, Bitna; Jeong, Jin-Sook; Lee, Seong-Wook

2017-02-01

Mutations in the KRAS gene, which persistently activate RAS function, are most frequently found in many types of human cancers. Here, we proposed and verified a new approach against cancers harboring the KRAS mutation with high cancer selectivity and efficient anti-cancer effects based on targeted RNA replacement. To this end, trans-splicing ribozymes from Tetrahymena group I intron were developed, which can specifically target and reprogram the mutant KRAS G12V transcript to induce therapeutic gene activity in cells. Adenoviral vectors containing the specific ribozymes with downstream suicide gene were constructed and then infection with the adenoviruses specifically downregulated KRAS G12V expression and killed KRAS G12V-harboring cancer cells additively upon pro-drug treatment, but it did not affect the growth of wild-type KRAS-expressing cells. Minimal liver toxicity was noted when the adenoviruses were administered systemically in vivo. Importantly, intratumoral injection of the adenoviruses with pro-drug treatment specifically and significantly impeded the growth of xenografted tumors harboring KRAS G12V through a trans-splicing reaction with the target RNA. In contrast, xenografted tumors harboring wild-type KRAS were not affected by the adenoviruses. Therefore, RNA replacement with a mutant KRAS-targeting trans-splicing ribozyme is a potentially useful therapeutic strategy to combat tumors harboring KRAS mutation. Copyright © 2017 The American Society of Gene and Cell Therapy. Published by Elsevier Inc. All rights reserved.

Mammalian target of rapamycin is essential for cardiomyocyte survival and heart development in mice

International Nuclear Information System (INIS)

Zhang, Pengpeng; Shan, Tizhong; Liang, Xinrong; Deng, Changyan; Kuang, Shihuan

2014-01-01

Highlights: • mTOR is a critical regulator of many biological processes yet its function in heart is not well understood. • MCK-Cre/Mtor flox/flox mice were established to delete Mtor in cardiomyocytes. • The mTOR-mKO mice developed normally but die prematurely within 5 weeks after birth due to heart disease. • The mTOR-mKO mice had dilated myocardium and increased cell death. • mTOR-mKO hearts had reduced expression of metabolic genes and activation of mTOR target proteins. - Abstract: Mammalian target of rapamycin (mTOR) is a critical regulator of protein synthesis, cell proliferation and energy metabolism. As constitutive knockout of Mtor leads to embryonic lethality, the in vivo function of mTOR in perinatal development and postnatal growth of heart is not well defined. In this study, we established a muscle-specific mTOR conditional knockout mouse model (mTOR-mKO) by crossing MCK-Cre and Mtor flox/flox mice. Although the mTOR-mKO mice survived embryonic and perinatal development, they exhibited severe postnatal growth retardation, cardiac muscle pathology and premature death. At the cellular level, the cardiac muscle of mTOR-mKO mice had fewer cardiomyocytes due to apoptosis and necrosis, leading to dilated cardiomyopathy. At the molecular level, the cardiac muscle of mTOR-mKO mice expressed lower levels of fatty acid oxidation and glycolysis related genes compared to the WT littermates. In addition, the mTOR-mKO cardiac muscle had reduced Myh6 but elevated Myh7 expression, indicating cardiac muscle degeneration. Furthermore, deletion of Mtor dramatically decreased the phosphorylation of S6 and AKT, two key targets downstream of mTORC1 and mTORC2 mediating the normal function of mTOR. These results demonstrate that mTOR is essential for cardiomyocyte survival and cardiac muscle function

Overexpression of angiopoietin 2 promotes the formation of oral squamous cell carcinoma by increasing epithelial-mesenchymal transition-induced angiogenesis.

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Li, C; Li, Q; Cai, Y; He, Y; Lan, X; Wang, W; Liu, J; Wang, S; Zhu, G; Fan, J; Zhou, Y; Sun, R

2016-09-01

Oral squamous cell carcinoma (OSCC) is the most common cancer of the head and neck and is associated with a high rate of lymph node metastasis. The initial step in the metastasis and transition of tumors is epithelial-mesenchymal transition (EMT)-induced angiogenesis, which can be mediated by angiopoietin 2 (ANG2), a key regulatory factor in angiogenesis. In the present study, immunohistochemistry and real-time quantitative reverse transcriptase (qRT-PCR) were used to measure the expression of ANG2 in OSCC tissues. Plasmids encoding ANG2 mRNA were used for increased ANG2 expression in the OSCC cell line TCA8113. The short interfering RNA (siRNA)-targeting ANG2 mRNA sequences were used to inhibit ANG2 expression in TCA8113 cells. Subsequently, transwell assays were performed to examine the effects of ANG2 on TCA8113 cell migration and invasion. Furthermore, in vivo assays were performed to assess the effect of ANG2 on tumor growth. Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assays and immunohistochemistry were used to examine cell apoptosis and angiogenesis in tumor tissues, respectively. Finally, western blot analysis was performed to evaluate tumor formation-related proteins in OSCC tissues. We found that protein expression of ANG2 was remarkably upregulated in OSCC tissues. Overexpression of ANG2 increased the migration and invasion of TCA8113 cells by regulating EMT. Further investigations showed that overexpression of ANG2 increased tumor growth in nude mice, and angiogenesis of OSCC tissues increased in the presence of ANG2 overexpression. Overexpression of ANG2 also reduced cell apoptosis in tumor tissue cells. Finally, we found that overexpression of ANG2 resulted in changes in the expression of tumor formation-related proteins including vimentin, E-cadherin, Bim, PUMA, Bcl-2, Bax, Cyclin D1, PCNA and CD31. Our findings show that ANG2 has an important role in the migration and invasion of OSCC. More importantly, further

BRCA1-IRIS Overexpression Promotes Formation of Aggressive Breast Cancers

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Shimizu, Yoshiko; Luk, Hugh; Horio, David; Miron, Penelope; Griswold, Michael; Iglehart, Dirk; Hernandez, Brenda; Killeen, Jeffrey; ElShamy, Wael M.

2012-01-01

Introduction Women with HER2+ or triple negative/basal-like (TN/BL) breast cancers succumb to their cancer rapidly due, in part to acquired Herceptin resistance and lack of TN/BL-targeted therapies. BRCA1-IRIS is a recently discovered, 1399 residue, BRCA1 locus alternative product, which while sharing 1365 residues with the full-length product of this tumor suppressor gene, BRCA1/p220, it has oncoprotein-like properties. Here, we examine whether BRCA1-IRIS is a valuable treatment target for HER2+ and/or TN/BL tumors. Methodology/Principal Findings Immunohistochemical staining of large cohort of human breast tumor samples using new monoclonal anti-BRCA1-IRIS antibody, followed by correlation of BRCA1-IRIS expression with that of AKT1, AKT2, p-AKT, survivin and BRCA1/p220, tumor status and age at diagnosis. Generation of subcutaneous tumors in SCID mice using human mammary epithelial (HME) cells overexpressing TERT/LT/BRCA1-IRIS, followed by comparing AKT, survivin, and BRCA1/p220 expression, tumor status and aggressiveness in these tumors to that in tumors developed using TERT/LT/RasV12-overexpressing HME cells. Induction of primary and invasive rat mammary tumors using the carcinogen N-methyl-N-nitrosourea (NMU), followed by analysis of rat BRCA1-IRIS and ERα mRNA levels in these tumors. High BRCA1-IRIS expression was detected in the majority of human breast tumors analyzed, which was positively correlated with that of AKT1-, AKT2-, p-AKT-, survivin, but negatively with BRCA1/p220 expression. BRCA1-IRIS-positivity induced high-grade, early onset and metastatic HER2+ or TN/BL tumors. TERT/LT/BRCA1-IRIS overexpressing HME cells formed invasive subcutaneous tumors that express high AKT1, AKT2, p-AKT and vimentin, but no CK19, p63 or BRCA1/p220. NMU-induced primary and invasive rat breast cancers expressed high levels of rat BRCA1-IRIS mRNA but low levels of rat ERα mRNA. Conclusion/Significance BRCA1-IRIS overexpression triggers aggressive breast tumor formation

Upregulation of triglyceride synthesis in skeletal muscle overexpressing DGAT1

OpenAIRE

Yang, Feifei; Wei, Zhuying; Ding, Xiangbin; Liu, Xinfeng; Ge, Xiuguo; Song, Guimin; Li, Guangpeng; Guo, Hong

2013-01-01

The gene encoding diacylglycerol acyltransferase (DGAT1) is a functional and positional candidate gene for milk and intramuscular fat content. A bovine DGAT1 overexpression vector was constructed containing mouse MCK promoter and bovine DGAT1 cDNA. MCK-DGAT1 transgene in FVB mice was researched in present study. The transgene DGAT1 had a high level of expression in contrast to the endogenous DGAT1 in posterior tibial muscle of the transgenic mice, but a low expression level in the cardiac mus...

Prediction of miRNA-mRNA associations in Alzheimer's disease mice using network topology.

Science.gov (United States)

Noh, Haneul; Park, Charny; Park, Soojun; Lee, Young Seek; Cho, Soo Young; Seo, Hyemyung

2014-08-03

Little is known about the relationship between miRNA and mRNA expression in Alzheimer's disease (AD) at early- or late-symptomatic stages. Sequence-based target prediction algorithms and anti-correlation profiles have been applied to predict miRNA targets using omics data, but this approach often leads to false positive predictions. Here, we applied the joint profiling analysis of mRNA and miRNA expression levels to Tg6799 AD model mice at 4 and 8 months of age using a network topology-based method. We constructed gene regulatory networks and used the PageRank algorithm to predict significant interactions between miRNA and mRNA. In total, 8 cluster modules were predicted by the transcriptome data for co-expression networks of AD pathology. In total, 54 miRNAs were identified as being differentially expressed in AD. Among these, 50 significant miRNA-mRNA interactions were predicted by integrating sequence target prediction, expression analysis, and the PageRank algorithm. We identified a set of miRNA-mRNA interactions that were changed in the hippocampus of Tg6799 AD model mice. We determined the expression levels of several candidate genes and miRNA. For functional validation in primary cultured neurons from Tg6799 mice (MT) and littermate (LM) controls, the overexpression of ARRDC3 enhanced PPP1R3C expression. ARRDC3 overexpression showed the tendency to decrease the expression of miR139-5p and miR3470a in both LM and MT primary cells. Pathological environment created by Aβ treatment increased the gene expression of PPP1R3C and Sfpq but did not significantly alter the expression of miR139-5p or miR3470a. Aβ treatment increased the promoter activity of ARRDC3 gene in LM primary cells but not in MT primary cells. Our results demonstrate AD-specific changes in the miRNA regulatory system as well as the relationship between the expression levels of miRNAs and their targets in the hippocampus of Tg6799 mice. These data help further our understanding of the function

Overexpression of eIF-5A2 in mice causes accelerated organismal aging by increasing chromosome instability

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Chen Leilei

2011-05-01

Full Text Available Abstract Background Amplification of 3q26 is one of the most frequent genetic alterations in many human malignancies. Recently, we isolated a novel oncogene eIF-5A2 within the 3q26 region. Functional study has demonstrated the oncogenic role of eIF-5A2 in the initiation and progression of human cancers. In the present study, we aim to investigate the physiological and pathological effect of eIF-5A2 in an eIF-5A2 transgenic mouse model. Methods An eIF-5A2 transgenic mouse model was generated using human eIF-5A2 cDNA. The eIF-5A2 transgenic mice were characterized by histological and immunohistochemistry analyses. The aging phenotypes were further characterized by wound healing, bone X-ray imaging and calcification analysis. Mouse embryo fibroblasts (MEF were isolated to further investigate molecular mechanism of eIF-5A2 in aging. Results Instead of resulting in spontaneous tumor formation, overexpression of eIF-5A2 accelerated the aging process in adult transgenic mice. This included decreased growth rate and body weight, shortened life span, kyphosis, osteoporosis, delay of wound healing and ossification. Investigation of the correlation between cellular senescence and aging showed that cellular senescence is not required for the aging phenotypes in eIF-5A2 mice. Interestingly, we found that activation of eIF-5A2 repressed p19 level and therefore destabilized p53 in transgenic mouse embryo fibroblast (MEF cells. This subsequently allowed for the accumulation of chromosomal instability, such as errors in cell dividing during metaphase and anaphase. Additionally, a significantly increase in number of aneuploidy cells (p Conclusion These observations suggest that eIF-5A2 mouse models could accelerate organismal aging by increasing chromosome instability.

Immunohistochemical determination of HER-2/neu overexpression in malignant melanoma reveals no prognostic value, while c-Kit (CD117 overexpression exhibits potential therapeutic implications

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Potti Anil

2003-01-01

Full Text Available Abstract Background HER-2/neu and c-kit (CD117 onco-protein are increasingly being recognized as targets for therapy in solid tumors, but data on their role in malignant melanoma is currently limited. We studied the prevalence of overexpression of HER-2/neu and c-Kit in 202 patients with malignant melanoma to evaluate a possible prognostic value of these molecular targets in malignant melanoma. Methods Overexpression of HER-2/neu and c-Kit was evaluated using immunohistochemical assays in 202 archival tissue specimens. Results Between 1991 and 2001, 202 subjects (109 males; 54% and 93 females; 46% with malignant melanoma were studied with a mean age of 57 years (age range: 15–101 years. The most common histologic type was amelanotic melanoma (n = 62; 30.7% followed by superficial spreading melanoma (n = 54; 26.7%. The depth of penetration of melanoma (Breslow thickness, pT Stage ranged from 0.4 mm (stage pT1 to 8.0 mm (stage pT4A. Mean thickness was 2.6 mm (stage pT3A. The ECOG performance scores ranged from 0 to 3. Only 2 patients (0.9% revealed HER-2/neu overexpression, whereas 46 (22.8% revealed c-Kit overexpression. Multivariate analysis performed did not show a significant difference in survival between c-Kit positive and negative groups (p = 0.36. Interestingly, not only was c-Kit more likely to be overexpressed in the superficial spreading type, a preliminary association between the presence or absence of c-Kit overexpression and the existence of another second primary tumor was also observed. Conclusions The results of our large study indicate that the HER-2/neu onco-protein neither has a role in melanogenesis nor is a potential target for clinical trials with monoclonal antibody therapy. This indicates there is no role for its testing in patients with malignant melanoma. Although c-Kit, expressed preferentially in the superficial spreading type, may not have prognostic value, it does have significant therapeutic implications as a

Systemic delivery of microRNA-101 potently inhibits hepatocellular carcinoma in vivo by repressing multiple targets.

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Fang Zheng

2015-02-01

Full Text Available Targeted therapy based on adjustment of microRNA (miRNAs activity takes great promise due to the ability of these small RNAs to modulate cellular behavior. However, the efficacy of miR-101 replacement therapy to hepatocellular carcinoma (HCC remains unclear. In the current study, we first observed that plasma levels of miR-101 were significantly lower in distant metastatic HCC patients than in HCCs without distant metastasis, and down-regulation of plasma miR-101 predicted a worse disease-free survival (DFS, P<0.05. In an animal model of HCC, we demonstrated that systemic delivery of lentivirus-mediated miR-101 abrogated HCC growth in the liver, intrahepatic metastasis and distant metastasis to the lung and to the mediastinum, resulting in a dramatic suppression of HCC development and metastasis in mice without toxicity and extending life expectancy. Furthermore, enforced overexpression of miR-101 in HCC cells not only decreased EZH2, COX2 and STMN1, but also directly down-regulated a novel target ROCK2, inhibited Rho/Rac GTPase activation, and blocked HCC cells epithelial-mesenchymal transition (EMT and angiogenesis, inducing a strong abrogation of HCC tumorigenesis and aggressiveness both in vitro and in vivo. These results provide proof-of-concept support for systemic delivery of lentivirus-mediated miR-101 as a powerful anti-HCC therapeutic modality by repressing multiple molecular targets.

Fish oil improves gene targets of Down syndrome in C57BL and BALB/c mice.

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Zmijewski, Peter A; Gao, Linda Y; Saxena, Abhinav R; Chavannes, Nastacia K; Hushmendy, Shazaan F; Bhoiwala, Devang L; Crawford, Dana R

2015-05-01

We have considered a novel gene targeting approach for treating pathologies and conditions whose genetic bases are defined using diet and nutrition. One such condition is Down syndrome, which is linked to overexpression of RCAN1 on human chromosome 21 for some phenotypes. We hypothesize that a decrease in RCAN1 expression with dietary supplements in individuals with Down syndrome represents a potential treatment. Toward this, we used in vivo studies and bioinformatic analysis to identify potential healthy dietary RCAN1 expression modulators. We observed Rcan1 isoform 1 (Rcan1-1) protein reduction in mice pup hippocampus after a 4-week curcumin and fish oil supplementation, with only fish oil reduction being statistically significant. Focusing on fish oil, we observed a 17% Rcan1-1 messenger RNA (mRNA) and 19% Rcan1-1 protein reduction in BALB/c mice after 5 weeks of fish oil supplementation. Fish oil supplementation starting at conception and in a different mouse strain (C57BL) led to a 27% reduction in hippocampal Rcan1-1 mRNA and a 34% reduction in spleen Rcan1-1 mRNA at 6 weeks of age. Hippocampal protein results revealed a modest 11% reduction in RCAN1-1, suggesting translational compensation. Bioinformatic mining of human fish oil studies also revealed reduced RCAN1 mRNA expression, consistent with the above studies. These results suggest the potential use of fish oil in treating Down syndrome and support our strategy of using select healthy dietary agents to treat genetically defined pathologies, an approach that we believe is simple, healthy, and cost-effective. Copyright © 2015 Elsevier Inc. All rights reserved.

Moderate elevation of intracellular creatine by targeting the creatine transporter protects mice from acute myocardial infarction

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Lygate, Craig A.; Bohl, Steffen; ten Hove, Michiel; Faller, Kiterie M.E.; Ostrowski, Philip J.; Zervou, Sevasti; Medway, Debra J.; Aksentijevic, Dunja; Sebag-Montefiore, Liam; Wallis, Julie; Clarke, Kieran; Watkins, Hugh; Schneider, Jürgen E.; Neubauer, Stefan

2012-01-01

Aims Increasing energy storage capacity by elevating creatine and phosphocreatine (PCr) levels to increase ATP availability is an attractive concept for protecting against ischaemia and heart failure. However, testing this hypothesis has not been possible since oral creatine supplementation is ineffectual at elevating myocardial creatine levels. We therefore used mice overexpressing creatine transporter in the heart (CrT-OE) to test for the first time whether elevated creatine is beneficial in clinically relevant disease models of heart failure and ischaemia/reperfusion (I/R) injury. Methods and results CrT-OE mice were selected for left ventricular (LV) creatine 20–100% above wild-type values and subjected to acute and chronic coronary artery ligation. Increasing myocardial creatine up to 100% was not detrimental even in ageing CrT-OE. In chronic heart failure, creatine elevation was neither beneficial nor detrimental, with no effect on survival, LV remodelling or dysfunction. However, CrT-OE hearts were protected against I/R injury in vivo in a dose-dependent manner (average 27% less myocardial necrosis) and exhibited greatly improved functional recovery following ex vivo I/R (59% of baseline vs. 29%). Mechanisms contributing to ischaemic protection in CrT-OE hearts include elevated PCr and glycogen levels and improved energy reserve. Furthermore, creatine loading in HL-1 cells did not alter antioxidant defences, but delayed mitochondrial permeability transition pore opening in response to oxidative stress, suggesting an additional mechanism to prevent reperfusion injury. Conclusion Elevation of myocardial creatine by 20–100% reduced myocardial stunning and I/R injury via pleiotropic mechanisms, suggesting CrT activation as a novel, potentially translatable target for cardiac protection from ischaemia. PMID:22915766

X11beta rescues memory and long-term potentiation deficits in Alzheimer's disease APPswe Tg2576 mice.

LENUS (Irish Health Repository)

Mitchell, Jacqueline C

2009-12-01

Increased production and deposition of amyloid beta-protein (Abeta) are believed to be key pathogenic events in Alzheimer\\'s disease. As such, routes for lowering cerebral Abeta levels represent potential therapeutic targets for Alzheimer\\'s disease. X11beta is a neuronal adaptor protein that binds to the intracellular domain of the amyloid precursor protein (APP). Overexpression of X11beta inhibits Abeta production in a number of experimental systems. However, whether these changes to APP processing and Abeta production induced by X11beta overexpression also induce beneficial effects to memory and synaptic plasticity are not known. We report here that X11beta-mediated reduction in cerebral Abeta is associated with normalization of both cognition and in vivo long-term potentiation in aged APPswe Tg2576 transgenic mice that model the amyloid pathology of Alzheimer\\'s disease. Overexpression of X11beta itself has no detectable adverse effects upon mouse behaviour. These findings support the notion that modulation of X11beta function represents a therapeutic target for Abeta-mediated neuronal dysfunction in Alzheimer\\'s disease.

Biochemical Characterization of Porphobilinogen Deaminase–Deficient Mice During Phenobarbital Induction of Heme Synthesis and the Effect of Enzyme Replacement

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Johansson, Annika; Möller, Christer; Fogh, Jens; Harper, Pauline

2003-01-01

Acute intermittent porphyria (AIP) is a genetic disorder caused by a deficiency of porphobilinogen deaminase (PBGD), the 3rd enzyme in heme synthesis. It is clinically characterized by acute attacks of neuropsychiatric symptoms and biochemically by increased urinary excretion of the porphyrin precursors porphobilinogen (PBG) and 5-aminolevulinic acid (ALA). A mouse model that is partially deficient in PBGD and biochemically mimics AIP after induction of the hepatic ALA synthase by phenobarbital was used in this study to identify the site of formation of the presumably toxic porphyrin precursors and study the effect of enzyme-replacement therapy by using recombinant human PBGD (rhPBGD). After 4 d of phenobarbital administration, high levels of PBG and ALA were found in liver, kidney, plasma, and urine of the PBGD-deficient mice. The administration of rhPBGD intravenously or subcutaneously after a 4-d phenobarbital induction was shown to lower the PBG level in plasma in a dose-dependent manner with maximal effect seen after 30 min and 2 h, respectively. Injection of rhPBGD subcutaneously twice daily during a 4-d phenobarbital induction reduced urinary PBG excretion to 25% of the levels found in PBGD-deficient mice administered with only phenobarbital. This study points to the liver as the main producer of PBG and ALA in the phenobarbital-induced PBGD-deficient mice and demonstrates efficient removal of accumulated PBG in plasma and urine by enzyme-replacement therapy. PMID:15208740

Tuning Hsf1 levels drives distinct fungal morphogenetic programs with depletion impairing Hsp90 function and overexpression expanding the target space

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Miao, Zhengqiang; Tan, Kaeling; Vyas, Valmik K.; Whiteway, Malcolm; Robbins, Nicole; Wong, Koon Ho; Cowen, Leah E.

2018-01-01

The capacity to respond to temperature fluctuations is critical for microorganisms to survive within mammalian hosts, and temperature modulates virulence traits of diverse pathogens. One key temperature-dependent virulence trait of the fungal pathogen Candida albicans is its ability to transition from yeast to filamentous growth, which is induced by environmental cues at host physiological temperature. A key regulator of temperature-dependent morphogenesis is the molecular chaperone Hsp90, which has complex functional relationships with the transcription factor Hsf1. Although Hsf1 controls global transcriptional remodeling in response to heat shock, its impact on morphogenesis remains unknown. Here, we establish an intriguing paradigm whereby overexpression or depletion of C. albicans HSF1 induces morphogenesis in the absence of external cues. HSF1 depletion compromises Hsp90 function, thereby driving filamentation. HSF1 overexpression does not impact Hsp90 function, but rather induces a dose-dependent expansion of Hsf1 direct targets that drives overexpression of positive regulators of filamentation, including Brg1 and Ume6, thereby bypassing the requirement for elevated temperature during morphogenesis. This work provides new insight into Hsf1-mediated environmentally contingent transcriptional control, implicates Hsf1 in regulation of a key virulence trait, and highlights fascinating biology whereby either overexpression or depletion of a single cellular regulator induces a profound developmental transition. PMID:29590106

Tuning Hsf1 levels drives distinct fungal morphogenetic programs with depletion impairing Hsp90 function and overexpression expanding the target space.

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Amanda O Veri

2018-03-01

Full Text Available The capacity to respond to temperature fluctuations is critical for microorganisms to survive within mammalian hosts, and temperature modulates virulence traits of diverse pathogens. One key temperature-dependent virulence trait of the fungal pathogen Candida albicans is its ability to transition from yeast to filamentous growth, which is induced by environmental cues at host physiological temperature. A key regulator of temperature-dependent morphogenesis is the molecular chaperone Hsp90, which has complex functional relationships with the transcription factor Hsf1. Although Hsf1 controls global transcriptional remodeling in response to heat shock, its impact on morphogenesis remains unknown. Here, we establish an intriguing paradigm whereby overexpression or depletion of C. albicans HSF1 induces morphogenesis in the absence of external cues. HSF1 depletion compromises Hsp90 function, thereby driving filamentation. HSF1 overexpression does not impact Hsp90 function, but rather induces a dose-dependent expansion of Hsf1 direct targets that drives overexpression of positive regulators of filamentation, including Brg1 and Ume6, thereby bypassing the requirement for elevated temperature during morphogenesis. This work provides new insight into Hsf1-mediated environmentally contingent transcriptional control, implicates Hsf1 in regulation of a key virulence trait, and highlights fascinating biology whereby either overexpression or depletion of a single cellular regulator induces a profound developmental transition.

Tuning Hsf1 levels drives distinct fungal morphogenetic programs with depletion impairing Hsp90 function and overexpression expanding the target space.

Science.gov (United States)

Veri, Amanda O; Miao, Zhengqiang; Shapiro, Rebecca S; Tebbji, Faiza; O'Meara, Teresa R; Kim, Sang Hu; Colazo, Juan; Tan, Kaeling; Vyas, Valmik K; Whiteway, Malcolm; Robbins, Nicole; Wong, Koon Ho; Cowen, Leah E

2018-03-01

The capacity to respond to temperature fluctuations is critical for microorganisms to survive within mammalian hosts, and temperature modulates virulence traits of diverse pathogens. One key temperature-dependent virulence trait of the fungal pathogen Candida albicans is its ability to transition from yeast to filamentous growth, which is induced by environmental cues at host physiological temperature. A key regulator of temperature-dependent morphogenesis is the molecular chaperone Hsp90, which has complex functional relationships with the transcription factor Hsf1. Although Hsf1 controls global transcriptional remodeling in response to heat shock, its impact on morphogenesis remains unknown. Here, we establish an intriguing paradigm whereby overexpression or depletion of C. albicans HSF1 induces morphogenesis in the absence of external cues. HSF1 depletion compromises Hsp90 function, thereby driving filamentation. HSF1 overexpression does not impact Hsp90 function, but rather induces a dose-dependent expansion of Hsf1 direct targets that drives overexpression of positive regulators of filamentation, including Brg1 and Ume6, thereby bypassing the requirement for elevated temperature during morphogenesis. This work provides new insight into Hsf1-mediated environmentally contingent transcriptional control, implicates Hsf1 in regulation of a key virulence trait, and highlights fascinating biology whereby either overexpression or depletion of a single cellular regulator induces a profound developmental transition.

Absence of Nrf2 or its selective overexpression in neurons and muscle does not affect survival in ALS-linked mutant hSOD1 mouse models.

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Marcelo R Vargas

Full Text Available The nuclear factor erythroid 2-related factor 2 (Nrf2 governs the expression of antioxidant and phase II detoxifying enzymes. Nrf2 activation can prevent or reduce cellular damage associated with several types of injury in many different tissues and organs. Dominant mutations in Cu/Zn-superoxide dismutase (SOD1 cause familial forms of amyotrophic lateral sclerosis (ALS, a fatal disorder characterized by the progressive loss of motor neurons and subsequent muscular atrophy. We have previously shown that Nrf2 activation in astrocytes delays neurodegeneration in ALS mouse models. To further investigate the role of Nrf2 in ALS we determined the effect of absence of Nrf2 or its restricted overexpression in neurons or type II skeletal muscle fibers on symptoms onset and survival in mutant hSOD1 expressing mice. We did not observe any detrimental effect associated with the lack of Nrf2 in two different mutant hSOD1 animal models of ALS. However, restricted Nrf2 overexpression in neurons or type II skeletal muscle fibers delayed disease onset but failed to extend survival in hSOD1(G93A mice. These results highlight the concept that not only the pharmacological target but also the cell type targeted may be relevant when considering a Nrf2-mediated therapeutic approach for ALS.

Overexpression of Thioredoxin-1 Blocks Morphine-Induced Conditioned Place Preference Through Regulating the Interaction of γ-Aminobutyric Acid and Dopamine Systems.

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Li, Xiang; Huang, Mengbing; Yang, Lihua; Guo, Ningning; Yang, Xiaoyan; Zhang, Zhimin; Bai, Ming; Ge, Lu; Zhou, Xiaoshuang; Li, Ye; Bai, Jie

2018-01-01

Morphine is one kind of opioid, which is currently the most effective widely utilized pain relieving pharmaceutical. Long-term administration of morphine leads to dependence and addiction. Thioredoxin-1 (Trx-1) is an important redox regulating protein and works as a neurotrophic cofactor. Our previous study showed that geranylgeranylaceton, an inducer of Trx-1 protected mice from rewarding effects induced by morphine. However, whether overexpression of Trx-1 can block morphine-induced conditioned place preference (CPP) in mice is still unknown. In this study, we first examined whether overexpression of Trx-1 affects the CPP after morphine training and further examined the dopamine (DA) and γ-aminobutyric acid (GABA) systems involved in rewarding effects. Our results showed that morphine-induced CPP was blocked in Trx-1 overexpression transgenic (TG) mice. Trx-1 expression was induced by morphine in the ventral tegmental area (VTA) and nucleus accumbens (NAc) in wild-type (WT) mice, which was not induced in Trx-1 TG mice. The DA level and expressions of tyrosine hydroxylase (TH) and D1 were induced by morphine in WT mice, which were not induced in Trx-1 TG mice. The GABA level and expression of GABA B R were decreased by morphine, which were restored in Trx-1 TG mice. Therefore, Trx-1 may play a role in blocking CPP induced by morphine through regulating the expressions of D1, TH, and GABA B R in the VTA and NAc.

Overexpression of Thioredoxin-1 Blocks Morphine-Induced Conditioned Place Preference Through Regulating the Interaction of γ-Aminobutyric Acid and Dopamine Systems

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Xiang Li

2018-05-01

Full Text Available Morphine is one kind of opioid, which is currently the most effective widely utilized pain relieving pharmaceutical. Long-term administration of morphine leads to dependence and addiction. Thioredoxin-1 (Trx-1 is an important redox regulating protein and works as a neurotrophic cofactor. Our previous study showed that geranylgeranylaceton, an inducer of Trx-1 protected mice from rewarding effects induced by morphine. However, whether overexpression of Trx-1 can block morphine-induced conditioned place preference (CPP in mice is still unknown. In this study, we first examined whether overexpression of Trx-1 affects the CPP after morphine training and further examined the dopamine (DA and γ-aminobutyric acid (GABA systems involved in rewarding effects. Our results showed that morphine-induced CPP was blocked in Trx-1 overexpression transgenic (TG mice. Trx-1 expression was induced by morphine in the ventral tegmental area (VTA and nucleus accumbens (NAc in wild-type (WT mice, which was not induced in Trx-1 TG mice. The DA level and expressions of tyrosine hydroxylase (TH and D1 were induced by morphine in WT mice, which were not induced in Trx-1 TG mice. The GABA level and expression of GABABR were decreased by morphine, which were restored in Trx-1 TG mice. Therefore, Trx-1 may play a role in blocking CPP induced by morphine through regulating the expressions of D1, TH, and GABABR in the VTA and NAc.

Pancreatic beta-cell lipotoxicity induced by overexpression of hormone-sensitive lipase

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Winzell, Maria Sörhede; Svensson, Håkan; Enerbäck, Sven

2003-01-01

Lipid perturbations associated with triglyceride overstorage in beta-cells impair insulin secretion, a process termed lipotoxicity. To assess the role of hormone-sensitive lipase, which is expressed and enzymatically active in beta-cells, in the development of lipotoxicity, we generated transgenic...... mice overexpressing hormone-sensitive lipase specifically in beta-cells. Transgenic mice developed glucose intolerance and severely blunted glucose-stimulated insulin secretion when challenged with a high-fat diet. As expected, both lipase activity and forskolin-stimulated lipolysis was increased...

Over-expressing the soluble gp130-Fc does not ameliorate methionine and choline deficient diet-induced non alcoholic steatohepatitis in mice.

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Helene L Kammoun

Full Text Available Non-alcoholic steatohepatitis (NASH is a liver disease with the potential to lead to cirrhosis and hepatocellular carcinoma. Interleukin-6 (IL-6 has been implicated in the pathogenesis of NASH, with the so-called IL-6 'trans-signaling' cascade being responsible for the pro-inflammatory actions of this cytokine. We aimed to block IL-6 'trans-signaling', using a transgenic mouse that overexpresses human soluble glycoprotein130 (sgp130Fc Tg mice fed a commonly used dietary model of inducing NASH (methionine and choline deficient-diet; MCD diet and hypothesized that markers of NASH would be ameliorated in such mice. Sgp130Fc Tg and littermate control mice were fed a MCD or control diet for 4 weeks. The MCD diet induced many hallmarks of NASH including hepatomegaly, steatosis, and liver inflammation. However, in contrast with other mouse models and, indeed, human NASH, the MCD diet model did not increase the mRNA or protein expression of IL-6. Not surprisingly, therefore, markers of MCD diet-induced NASH were unaffected by sgp130Fc transgenic expression. While the MCD diet model induces many pathophysiological markers of NASH, it does not induce increased IL-6 expression in the liver, a key hallmark of human NASH. We, therefore, caution the use of the MCD diet as a viable mouse model of NASH.

Overexpression of antioxidant enzymes in diaphragm muscle does not alter contraction-induced fatigue or recovery

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McClung, Joseph M.; DeRuisseau, Keith C.; Whidden, Melissa A.; Van Remmen, Holly; Richardson, Arlan; Song, Wook; Vrabas, Ioannis S.; Powers, Scott K.

2010-01-01

Low levels of reactive oxygen species (ROS) production are necessary to optimize muscle force production in unfatigued muscle. In contrast, sustained high levels of ROS production have been linked to impaired muscle force production and contraction-induced skeletal muscle fatigue. Using genetically engineered mice, we tested the hypothesis that the independent transgenic overexpression of catalase (CAT), copper/zinc superoxide dismutase (CuZnSOD; SOD1) or manganese superoxide dismutase (MnSOD; SOD2) antioxidant enzymes would negatively affect force production in unfatigued diaphragm muscle but would delay the development of muscle fatigue and enhance force recovery after fatiguing contractions. Diaphragm muscle from wild-type littermates (WT) and from CAT, SOD1 and SOD2 overexpressing mice were subjected to an in vitro contractile protocol to investigate the force–frequency characteristics, the fatigue properties and the time course of recovery from fatigue. The CAT, SOD1 and SOD2 overexpressors produced less specific force (in N cm−2) at stimulation frequencies of 20–300 Hz and produced lower maximal tetanic force than WT littermates. The relative development of muscle fatigue and recovery from fatigue were not influenced by transgenic overexpression of any antioxidant enzyme. Morphologically, the mean cross-sectional area (in μm2) of diaphragm myofibres expressing myosin heavy chain type IIA was decreased in both CAT and SOD2 transgenic animals, and the percentage of non-contractile tissue increased in diaphragms from all transgenic mice. In conclusion, our results do not support the hypothesis that overexpression of independent antioxidant enzymes protects diaphragm muscle from contraction-induced fatigue or improves recovery from fatigue. Moreover, our data are consistent with the concept that a basal level of ROS is important to optimize muscle force production, since transgenic overexpression of major cellular antioxidants is associated with

The CRKL gene encoding an adaptor protein is amplified, overexpressed, and a possible therapeutic target in gastric cancer

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Natsume Hiroko

2012-07-01

Full Text Available Abstract Background Genomic DNA amplification is a genetic factor involved in cancer, and some oncogenes, such as ERBB2, are highly amplified in gastric cancer. We searched for the possible amplification of other genes in gastric cancer. Methods and Results A genome-wide single nucleotide polymorphism microarray analysis was performed using three cell lines of differentiated gastric cancers, and 22 genes (including ERBB2 in five highly amplified chromosome regions (with a copy number of more than 6 were identified. Particular attention was paid to the CRKL gene, the product of which is an adaptor protein containing Src homology 2 and 3 (SH2/SH3 domains. An extremely high CRKL copy number was confirmed in the MKN74 gastric cancer cell line using fluorescence in situ hybridization (FISH, and a high level of CRKL expression was also observed in the cells. The RNA-interference-mediated knockdown of CRKL in MKN74 disclosed the ability of CRKL to upregulate gastric cell proliferation. An immunohistochemical analysis revealed that CRKL protein was overexpressed in 24.4% (88/360 of the primary gastric cancers that were analyzed. The CRKL copy number was also examined in 360 primary gastric cancers using a FISH analysis, and CRKL amplification was found to be associated with CRKL overexpression. Finally, we showed that MKN74 cells with CRKL amplification were responsive to the dual Src/BCR-ABL kinase inhibitor BMS354825, likely via the inhibition of CRKL phosphorylation, and that the proliferation of MKN74 cells was suppressed by treatment with a CRKL-targeting peptide. Conclusion These results suggested that CRKL protein is overexpressed in a subset of gastric cancers and is associated with CRKL amplification in gastric cancer. Furthermore, our results suggested that CRKL protein has the ability to regulate gastric cell proliferation and has the potential to serve as a molecular therapy target for gastric cancer.

Analysis of human protein replacement stable cell lines established using snoMEN-PR vector.

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Motoharu Ono

Full Text Available The study of the function of many human proteins is often hampered by technical limitations, such as cytotoxicity and phenotypes that result from overexpression of the protein of interest together with the endogenous version. Here we present the snoMEN (snoRNA Modulator of gene ExpressioN vector technology for generating stable cell lines where expression of the endogenous protein can be reduced and replaced by an exogenous protein, such as a fluorescent protein (FP-tagged version. SnoMEN are snoRNAs engineered to contain complementary sequences that can promote knock-down of targeted RNAs. We have established and characterised two such partial protein replacement human cell lines (snoMEN-PR. Quantitative mass spectrometry was used to analyse the specificity of knock-down and replacement at the protein level and also showed an increased pull-down efficiency of protein complexes containing exogenous, tagged proteins in the protein replacement cell lines, as compared with conventional co-expression strategies. The snoMEN approach facilitates the study of mammalian proteins, particularly those that have so far been difficult to investigate by exogenous expression and has wide applications in basic and applied gene-expression research.

Long-term imaging in awake mice using removable cranial windows

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Glickfeld, Lindsey L.; Kerlin, Aaron M.; Reid, R. Clay; Bonin, Vincent; Schafer, Dorothy P.; Andermann, Mark L.

2015-01-01

Cranial window implants in head-fixed rodents are becoming a preparation of choice for stable optical access to large areas of cortex over extended periods of time. Here, we provide a highly detailed and reliable surgical protocol for a cranial window implantation procedure for chronic widefield and cellular imaging in awake, head-fixed mice, which enables subsequent window removal and replacement in the weeks and months following the initial craniotomy. This protocol has facilitated awake, chronic imaging in adolescent as well as adult mice over several months from a large number of cortical brain regions; targeted virus and tracer injections from data obtained using prior awake functional mapping; and functionally-targeted two-photon imaging across all cortical layers in awake mice using a microprism attachment to the cranial window. Collectively, these procedures extend the reach of chronic imaging of cortical function and dysfunction in behaving animals. PMID:25275789

Cardiac-Specific Overexpression of Catalase Attenuates Lipopolysaccharide-Induced Myocardial Contractile Dysfunction: Role of Autophagy

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Turdi, Subat; Han, Xuefeng; Huff, Anna F.; Roe, Nathan D.; Hu, Nan; Gao, Feng; Ren, Jun

2012-01-01

Lipopolysaccharide (LPS) from Gram-negative bacteria is a major initiator of sepsis, leading to cardiovascular collapse. Accumulating evidence has indicated a role of reactive oxygen species (ROS) in cardiovascular complication in sepsis. This study was designed to examine the effect of cardiac-specific overexpression of catalase in LPS-induced cardiac contractile dysfunction and the underlying mechanism(s) with a focus on autophagy. Catalase transgenic and wild-type FVB mice were challenged with LPS (6 mg/kg) and cardiac function was evaluated. Levels of oxidative stress, autophagy, apoptosis and protein damage were examined using fluorescence microscopy, Western blot, TUNEL assay, caspase-3 activity and carbonyl formation. Kaplan-Meier curve was constructed for survival following LPS treatment. Our results revealed a lower mortality in catalase mice compared with FVB mice following LPS challenge. LPS injection led to depressed cardiac contractile capacity as evidenced by echocardiography and cardiomyocyte contractile function, the effect of which was ablated by catalase overexpression. LPS treatment induced elevated TNF-α level, autophagy, apoptosis (TUNEL, caspase-3 activation, cleaved caspase-3), production of ROS and O2−, and protein carbonyl formation, the effects of which were significantly attenuated by catalase overexpression. Electron microscopy revealed focal myocardial damage characterized by mitochondrial injury following LPS treatment, which was less severe in catalase mice. Interestingly, LPS-induced cardiomyocyte contractile dysfunction was prevented by antioxidant NAC and the autophagy inhibitor 3-methyladenine. Taken together, our data revealed that catalase protects against LPS-induced cardiac dysfunction and mortality, which may be associated with inhibition of oxidative stress and autophagy. PMID:22902401

Mammalian target of rapamycin is essential for cardiomyocyte survival and heart development in mice

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Zhang, Pengpeng [Key Laboratory of Swine Genetics and Breeding, Ministry of Agriculture, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction, Ministry of Education, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); Department of Animal Sciences, Purdue University, West Lafayette, IN 47907 (United States); Shan, Tizhong; Liang, Xinrong [Department of Animal Sciences, Purdue University, West Lafayette, IN 47907 (United States); Deng, Changyan [Key Laboratory of Swine Genetics and Breeding, Ministry of Agriculture, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction, Ministry of Education, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); Kuang, Shihuan, E-mail: skuang@purdue.edu [Department of Animal Sciences, Purdue University, West Lafayette, IN 47907 (United States)

2014-09-12

Highlights: • mTOR is a critical regulator of many biological processes yet its function in heart is not well understood. • MCK-Cre/Mtor{sup flox/flox} mice were established to delete Mtor in cardiomyocytes. • The mTOR-mKO mice developed normally but die prematurely within 5 weeks after birth due to heart disease. • The mTOR-mKO mice had dilated myocardium and increased cell death. • mTOR-mKO hearts had reduced expression of metabolic genes and activation of mTOR target proteins. - Abstract: Mammalian target of rapamycin (mTOR) is a critical regulator of protein synthesis, cell proliferation and energy metabolism. As constitutive knockout of Mtor leads to embryonic lethality, the in vivo function of mTOR in perinatal development and postnatal growth of heart is not well defined. In this study, we established a muscle-specific mTOR conditional knockout mouse model (mTOR-mKO) by crossing MCK-Cre and Mtor{sup flox/flox} mice. Although the mTOR-mKO mice survived embryonic and perinatal development, they exhibited severe postnatal growth retardation, cardiac muscle pathology and premature death. At the cellular level, the cardiac muscle of mTOR-mKO mice had fewer cardiomyocytes due to apoptosis and necrosis, leading to dilated cardiomyopathy. At the molecular level, the cardiac muscle of mTOR-mKO mice expressed lower levels of fatty acid oxidation and glycolysis related genes compared to the WT littermates. In addition, the mTOR-mKO cardiac muscle had reduced Myh6 but elevated Myh7 expression, indicating cardiac muscle degeneration. Furthermore, deletion of Mtor dramatically decreased the phosphorylation of S6 and AKT, two key targets downstream of mTORC1 and mTORC2 mediating the normal function of mTOR. These results demonstrate that mTOR is essential for cardiomyocyte survival and cardiac muscle function.

Interleukin-6 overexpression induces pulmonary hypertension.

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Steiner, M Kathryn; Syrkina, Olga L; Kolliputi, Narasaish; Mark, Eugene J; Hales, Charles A; Waxman, Aaron B

2009-01-30

Inflammatory cytokine interleukin (IL)-6 is elevated in the serum and lungs of patients with pulmonary artery hypertension (PAH). Several animal models of PAH cite the potential role of inflammatory mediators. We investigated role of IL-6 in the pathogenesis of pulmonary vascular disease. Indices of pulmonary vascular remodeling were measured in lung-specific IL-6-overexpressing transgenic mice (Tg(+)) and compared to wild-type (Tg(-)) controls in both normoxic and chronic hypoxic conditions. The Tg(+) mice exhibited elevated right ventricular systolic pressures and right ventricular hypertrophy with corresponding pulmonary vasculopathic changes, all of which were exacerbated by chronic hypoxia. IL-6 overexpression increased muscularization of the proximal arterial tree, and hypoxia enhanced this effect. It also reproduced the muscularization and proliferative arteriopathy seen in the distal arteriolar vessels of PAH patients. The latter was characterized by the formation of occlusive neointimal angioproliferative lesions that worsened with hypoxia and were composed of endothelial cells and T-lymphocytes. IL-6-induced arteriopathic changes were accompanied by activation of proangiogenic factor, vascular endothelial growth factor, the proproliferative kinase extracellular signal-regulated kinase, proproliferative transcription factors c-MYC and MAX, and the antiapoptotic proteins survivin and Bcl-2 and downregulation of the growth inhibitor transforming growth factor-beta and proapoptotic kinases JNK and p38. These findings suggest that IL-6 promotes the development and progression of pulmonary vascular remodeling and PAH through proproliferative antiapoptotic mechanisms.

β-Cell Replacement in Mice Using Human Type 1 Diabetes Nuclear Transfer Embryonic Stem Cells.

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Sui, Lina; Danzl, Nichole; Campbell, Sean R; Viola, Ryan; Williams, Damian; Xing, Yuan; Wang, Yong; Phillips, Neil; Poffenberger, Greg; Johannesson, Bjarki; Oberholzer, Jose; Powers, Alvin C; Leibel, Rudolph L; Chen, Xiaojuan; Sykes, Megan; Egli, Dieter

2018-01-01

β-Cells derived from stem cells hold great promise for cell replacement therapy for diabetes. Here we examine the ability of nuclear transfer embryonic stem cells (NT-ESs) derived from a patient with type 1 diabetes to differentiate into β-cells and provide a source of autologous islets for cell replacement. NT-ESs differentiate in vitro with an average efficiency of 55% into C-peptide-positive cells, expressing markers of mature β-cells, including MAFA and NKX6.1. Upon transplantation in immunodeficient mice, grafted cells form vascularized islet-like structures containing MAFA/C-peptide-positive cells. These β-cells adapt insulin secretion to ambient metabolite status and show normal insulin processing. Importantly, NT-ES-β-cells maintain normal blood glucose levels after ablation of the mouse endogenous β-cells. Cystic structures, but no teratomas, were observed in NT-ES-β-cell grafts. Isogenic induced pluripotent stem cell lines showed greater variability in β-cell differentiation. Even though different methods of somatic cell reprogramming result in stem cell lines that are molecularly indistinguishable, full differentiation competence is more common in ES cell lines than in induced pluripotent stem cell lines. These results demonstrate the suitability of NT-ES-β-cells for cell replacement for type 1 diabetes and provide proof of principle for therapeutic cloning combined with cell therapy. © 2017 by the American Diabetes Association.

Prothymosin α overexpression contributes to the development of pulmonary emphysema

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Su, Bing-Hua; Tseng, Yau-Lin; Shieh, Gia-Shing; Chen, Yi-Cheng; Shiang, Ya-Chieh; Wu, Pensee; Li, Kuo-Jung; Yen, Te-Hsin; Shiau, Ai-Li; Wu, Chao-Liang

2013-01-01

Emphysema is one of the disease conditions that comprise chronic obstructive pulmonary disease. Prothymosin α transgenic mice exhibit an emphysema phenotype, but the pathophysiological role of prothymosin α in emphysema remains unclear. Here we show that prothymosin α contributes to the pathogenesis of emphysema by increasing acetylation of histones and nuclear factor-kappaB, particularly upon cigarette smoke exposure. We find a positive correlation between prothymosin α levels and the severity of emphysema in prothymosin α transgenic mice and emphysema patients. Prothymosin α overexpression increases susceptibility to cigarette smoke-induced emphysema, and cigarette smoke exposure further enhances prothymosin α expression. We show that prothymosin α inhibits the association of histone deacetylases with histones and nuclear factor-kappaB, and that prothymosin α overexpression increases expression of nuclear factor-kappaB-dependent matrix metalloproteinase 2 and matrix metalloproteinase 9, which are found in the lungs of patients with chronic obstructive pulmonary disease. These results demonstrate the clinical relevance of prothymosin α in regulating acetylation events during the pathogenesis of emphysema. PMID:23695700

Overexpression of the long noncoding RNA TUG1 protects against cold-induced injury of mouse livers by inhibiting apoptosis and inflammation.

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Su, Song; Liu, Jiang; He, Kai; Zhang, Mengyu; Feng, Chunhong; Peng, Fangyi; Li, Bo; Xia, Xianming

2016-04-01

Hepatic injury provoked by cold storage is a major problem affecting liver transplantation, as exposure to cold induces apoptosis in hepatic tissues. Long noncoding RNAs (lncRNAs) are increasingly understood to regulate apoptosis, but the contribution of lncRNAs to cold-induced liver injury remains unknown. Using RNA-seq, we determined the differential lncRNA expression profile in mouse livers after cold storage and found that expression of the lncRNA TUG1 was significantly down-regulated. Overexpression of TUG1 attenuated cold-induced apoptosis in mouse hepatocytes and liver sinusoidal endothelial cells LSECs, in part by blocking mitochondrial apoptosis and endoplasmic reticulum (ER) stress pathways. Moreover, TUG1 attenuated apoptosis, inflammation, and oxidative stress in vivo in livers subjected to cold storage. Overexpression of TUG1 also improved hepatocyte function and prolonged hepatic graft survival rates in mice. These results suggest that the lncRNA TUG1 exerts a protective effect against cold-induced liver damage by inhibiting apoptosis in mice, and suggests a potential role for TUG1 as a target for the prevention of cold-induced liver damage in liver transplantation. RNA-seq data are available from GEO using accession number GSE76609. © 2016 Federation of European Biochemical Societies.

Mitochondrial catalase overexpressed transgenic mice are protected against lung fibrosis in part via preventing alveolar epithelial cell mitochondrial DNA damage.

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Kim, Seok-Jo; Cheresh, Paul; Jablonski, Renea P; Morales-Nebreda, Luisa; Cheng, Yuan; Hogan, Erin; Yeldandi, Anjana; Chi, Monica; Piseaux, Raul; Ridge, Karen; Michael Hart, C; Chandel, Navdeep; Scott Budinger, G R; Kamp, David W

2016-12-01

Alveolar epithelial cell (AEC) injury and mitochondrial dysfunction are important in the development of lung fibrosis. Our group has shown that in the asbestos exposed lung, the generation of mitochondrial reactive oxygen species (ROS) in AEC mediate mitochondrial DNA (mtDNA) damage and apoptosis which are necessary for lung fibrosis. These data suggest that mitochondrial-targeted antioxidants should ameliorate asbestos-induced lung. To determine whether transgenic mice that express mitochondrial-targeted catalase (MCAT) have reduced lung fibrosis following exposure to asbestos or bleomycin and, if so, whether this occurs in association with reduced AEC mtDNA damage and apoptosis. Crocidolite asbestos (100µg/50µL), TiO 2 (negative control), bleomycin (0.025 units/50µL), or PBS was instilled intratracheally in 8-10 week-old wild-type (WT - C57Bl/6J) or MCAT mice. The lungs were harvested at 21d. Lung fibrosis was quantified by collagen levels (Sircol) and lung fibrosis scores. AEC apoptosis was assessed by cleaved caspase-3 (CC-3)/Surfactant protein C (SFTPC) immunohistochemistry (IHC) and semi-quantitative analysis. AEC (primary AT2 cells from WT and MCAT mice and MLE-12 cells) mtDNA damage was assessed by a quantitative PCR-based assay, apoptosis was assessed by DNA fragmentation, and ROS production was assessed by a Mito-Sox assay. Compared to WT, crocidolite-exposed MCAT mice exhibit reduced pulmonary fibrosis as measured by lung collagen levels and lung fibrosis score. The protective effects in MCAT mice were accompanied by reduced AEC mtDNA damage and apoptosis. Similar findings were noted following bleomycin exposure. Euk-134, a mitochondrial SOD/catalase mimetic, attenuated MLE-12 cell DNA damage and apoptosis. Finally, compared to WT, asbestos-induced MCAT AT2 cell ROS production was reduced. Our finding that MCAT mice have reduced pulmonary fibrosis, AEC mtDNA damage and apoptosis following exposure to asbestos or bleomycin suggests an important role

Overexpression of xeroderma pigmentosum group C decreases the chemotherapeutic sensitivity of colorectal carcinoma cells to cisplatin.

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Zhang, Yi; Cao, Jia; Meng, Yanni; Qu, Chunying; Shen, Feng; Xu, Leiming

2018-05-01

Xeroderma pigmentosum group C (XPC) is a DNA-damage-recognition gene active at the early stage of DNA repair. XPC also participates in regulation of cell-cycle checkpoint and DNA-damage-induced apoptosis. In the present study, the expression levels of genes involved in nucleotide excision repair (NER) were assessed in human colorectal cancer (CRC) tissue. This analysis revealed that expression of XPC mRNA significantly increased in colorectal carcinoma tissues compared with matched normal controls. Expression of XPC gradually increased along with the degree of progression of CRC. In vitro , an XTT assay demonstrated that small interfering RNA (siRNA) targeting XPC significantly increased the sensitivity of CRC SW480 cells to cisplatin, whereas cells transfected with a XPC-overexpression plasmid became more resistant to cisplatin. Furthermore, flow cytometry revealed that the proportion of apoptotic cells significantly increased in XPC-knockdown cells upon cisplatin treatment. However, the overexpression XPC significantly increased the resistance of cells to cisplatin. In vivo , tumor growth was significantly reduced in tumor-bearing mice when the XPC gene was knocked down. Upregulation of the expression of pro-apoptotic Bcl-associated X and downregulation of the anti-apoptotic B-cell lymphoma 2 proteins was observed in the implanted tumor tissue. In conclusion, XPC serves a key role in chemotherapeutic sensitivity of CRC to cisplatin, meaning that it may be a potential target for chemotherapy of CRC.

Transgenic overexpression of 14-3-3 zeta protects hippocampus against endoplasmic reticulum stress and status epilepticus in vivo.

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Gary P Brennan

Full Text Available 14-3-3 proteins are ubiquitous molecular chaperones that are abundantly expressed in the brain where they regulate cell functions including metabolism, the cell cycle and apoptosis. Brain levels of several 14-3-3 isoforms are altered in diseases of the nervous system, including epilepsy. The 14-3-3 zeta (ζ isoform has been linked to endoplasmic reticulum (ER function in neurons, with reduced levels provoking ER stress and increasing vulnerability to excitotoxic injury. Here we report that transgenic overexpression of 14-3-3ζ in mice results in selective changes to the unfolded protein response pathway in the hippocampus, including down-regulation of glucose-regulated proteins 78 and 94, activating transcription factors 4 and 6, and Xbp1 splicing. No differences were found between wild-type mice and transgenic mice for levels of other 14-3-3 isoforms or various other 14-3-3 binding proteins. 14-3-3ζ overexpressing mice were potently protected against cell death caused by intracerebroventricular injection of the ER stressor tunicamycin. 14-3-3ζ overexpressing mice were also potently protected against neuronal death caused by prolonged seizures. These studies demonstrate that increased 14-3-3ζ levels protect against ER stress and seizure-damage despite down-regulation of the unfolded protein response. Delivery of 14-3-3ζ may protect against pathologic changes resulting from prolonged or repeated seizures or where injuries provoke ER stress.

A Novel ¹¹¹In-Labeled Anti-Prostate-Specific Membrane Antigen Nanobody for Targeted SPECT/CT Imaging of Prostate Cancer.

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Chatalic, Kristell L S; Veldhoven-Zweistra, Joke; Bolkestein, Michiel; Hoeben, Sander; Koning, Gerben A; Boerman, Otto C; de Jong, Marion; van Weerden, Wytske M

2015-07-01

Prostate-specific membrane antigen (PSMA) is overexpressed in prostate cancer (PCa) and a promising target for molecular imaging and therapy. Nanobodies (single-domain antibodies, VHH) are the smallest antibody-based fragments possessing ideal molecular imaging properties, such as high target specificity and rapid background clearance. We developed a novel anti-PSMA Nanobody (JVZ-007) for targeted imaging and therapy of PCa. Here, we report on the application of the (111)In-radiolabeled Nanobody for SPECT/CT imaging of PCa. A Nanobody library was generated by immunization of a llama with 4 human PCa cell lines. Anti-PSMA Nanobodies were captured by biopanning on PSMA-overexpressing cells. JVZ-007 was selected for evaluation as an imaging probe. JVZ-007 was initially produced with a c-myc-hexahistidine (his) tag allowing purification and detection. The c-myc-his tag was subsequently replaced by a single cysteine at the C terminus, allowing site-specific conjugation of chelates for radiolabeling. JVZ-007-c-myc-his was conjugated to 2-(4-isothiocyanatobenzyl)-diethylenetriaminepentaacetic acid (p-SCN-DTPA) via the lysines, whereas JVZ-007-cys was conjugated to maleimide-DTPA via the C-terminal cysteine. PSMA targeting was analyzed in vitro by cell-binding experiments using flow cytometry, autoradiography, and internalization assays with various PCa cell lines and patient-derived xenografts (PDXs). The targeting properties of radiolabeled Nanobodies were evaluated in vivo in biodistribution and SPECT/CT imaging experiments, using nude mice bearing PSMA-positive PC-310 and PSMA-negative PC-3 tumors. JVZ-007 was successfully conjugated to DTPA for radiolabeling with (111)In at room temperature. (111)In-JVZ007-c-myc-his and (111)In-JVZ007-cys internalized in LNCaP cells and bound to PSMA-expressing PDXs and, importantly, not to PSMA-negative PDXs and human kidneys. Good tumor targeting and fast blood clearance were observed for (111)In-JVZ-007-c-myc-his and (111)In

Concurrent nuclear ERG and MYC protein overexpression defines a subset of locally advanced prostate cancer: Potential opportunities for synergistic targeted therapeutics.

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Udager, Aaron M; DeMarzo, Angelo M; Shi, Yang; Hicks, Jessica L; Cao, Xuhong; Siddiqui, Javed; Jiang, Hui; Chinnaiyan, Arul M; Mehra, Rohit

2016-06-01

Recurrent ERG gene fusions, the most common genetic alterations in prostate cancer, drive overexpression of the nuclear transcription factor ERG, and are early clonal events in prostate cancer progression. The nuclear transcription factor MYC is also frequently overexpressed in prostate cancer and may play a role in tumor initiation and/or progression. The relationship between nuclear ERG and MYC protein overexpression in prostate cancer, as well as the clinicopathologic characteristics and prognosis of ERG-positive/MYC high tumors, is not well understood. Immunohistochemistry (IHC) for ERG and MYC was performed on formalin-fixed, paraffin-embedded tissue from prostate cancer tissue microarrays (TMAs), and nuclear staining was scored semi-quantitatively (IHC product score range = 0-300). Correlation between nuclear ERG and MYC protein expression and association with clinicopathologic parameters and biochemical recurrence after radical prostatectomy was assessed. 29.1% of all tumor nodules showed concurrent nuclear ERG and MYC protein overexpression (i.e., ERG-positive/MYC high), including 35.0% of secondary nodules. Overall, there was weak positive correlation between ERG and MYC expression across all tumor nodules (rpb  = 0.149, P = 0.045), although this correlation was strongest in secondary nodules (rpb  = 0.520, P = 0.019). In radical prostatectomy specimens, ERG-positive/MYC high tumors were positively associated with the presence of extraprostatic extension (EPE), relative to all other ERG/MYC expression subgroups, however, there was no significant association between concurrent nuclear ERG and MYC protein overexpression and time to biochemical recurrence. Concurrent nuclear ERG and MYC protein overexpression is common in prostate cancer and defines a subset of locally advanced tumors. Recent data indicates that BET bromodomain proteins regulate ERG gene fusion and MYC gene expression in prostate cancer, suggesting possible synergistic

Overexpression of Catalase Diminishes Oxidative Cysteine Modifications of Cardiac Proteins.

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Chunxiang Yao

Full Text Available Reactive protein cysteine thiolates are instrumental in redox regulation. Oxidants, such as hydrogen peroxide (H2O2, react with thiolates to form oxidative post-translational modifications, enabling physiological redox signaling. Cardiac disease and aging are associated with oxidative stress which can impair redox signaling by altering essential cysteine thiolates. We previously found that cardiac-specific overexpression of catalase (Cat, an enzyme that detoxifies excess H2O2, protected from oxidative stress and delayed cardiac aging in mice. Using redox proteomics and systems biology, we sought to identify the cysteines that could play a key role in cardiac disease and aging. With a 'Tandem Mass Tag' (TMT labeling strategy and mass spectrometry, we investigated differential reversible cysteine oxidation in the cardiac proteome of wild type and Cat transgenic (Tg mice. Reversible cysteine oxidation was measured as thiol occupancy, the ratio of total available versus reversibly oxidized cysteine thiols. Catalase overexpression globally decreased thiol occupancy by ≥1.3 fold in 82 proteins, including numerous mitochondrial and contractile proteins. Systems biology analysis assigned the majority of proteins with differentially modified thiols in Cat Tg mice to pathways of aging and cardiac disease, including cellular stress response, proteostasis, and apoptosis. In addition, Cat Tg mice exhibited diminished protein glutathione adducts and decreased H2O2 production from mitochondrial complex I and II, suggesting improved function of cardiac mitochondria. In conclusion, our data suggest that catalase may alleviate cardiac disease and aging by moderating global protein cysteine thiol oxidation.

Contribution of V(H replacement products in mouse antibody repertoire.

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Lin Huang

Full Text Available VH replacement occurs through RAG-mediated recombination between the cryptic recombination signal sequence (cRSS near the 3' end of a rearranged VH gene and the 23-bp RSS from an upstream unrearranged VH gene. Due to the location of the cRSS, VH replacement leaves a short stretch of nucleotides from the previously rearranged VH gene at the newly formed V-D junction, which can be used as a marker to identify VH replacement products. To determine the contribution of VH replacement products to mouse antibody repertoire, we developed a Java-based VH Replacement Footprint Analyzer (VHRFA program and analyzed 17,179 mouse IgH gene sequences from the NCBI database to identify VH replacement products. The overall frequency of VH replacement products in these IgH genes is 5.29% based on the identification of pentameric VH replacement footprints at their V-D junctions. The identified VH replacement products are distributed similarly in IgH genes using most families of VH genes, although different families of VH genes are used differentially. The frequencies of VH replacement products are significantly elevated in IgH genes derived from several strains of autoimmune prone mice and in IgH genes encoding autoantibodies. Moreover, the identified VH replacement footprints in IgH genes from autoimmune prone mice or IgH genes encoding autoantibodies preferentially encode positively charged amino acids. These results revealed a significant contribution of VH replacement products to the diversification of antibody repertoire and potentially, to the generation of autoantibodies in mice.

Pancreatic beta-cell overexpression of the glucagon receptor gene results in enhanced beta-cell function and mass

DEFF Research Database (Denmark)

Gelling, Richard W; Vuguin, Patricia M; Du, Xiu Quan

2009-01-01

in vivo, we generated mice overexpressing the Gcgr specifically on pancreatic beta-cells (RIP-Gcgr). In vivo and in vitro insulin secretion in response to glucagon and glucose was increased 1.7- to 3.9-fold in RIP-Gcgr mice compared with controls. Consistent with the observed increase in insulin release...

Sirtuin1 Over-Expression Does Not Impact Retinal Vascular and Neuronal Degeneration in a Mouse Model of Oxygen-Induced Retinopathy

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Michan, Shaday; Juan, Aimee M.; Hurst, Christian G.; Cui, Zhenghao; Evans, Lucy P.; Hatton, Colman J.; Pei, Dorothy T.; Ju, Meihua; Sinclair, David A.; Smith, Lois E. H.; Chen, Jing

2014-01-01

Proliferative retinopathy is a leading cause of blindness, including retinopathy of prematurity (ROP) in children and diabetic retinopathy in adults. Retinopathy is characterized by an initial phase of vessel loss, leading to tissue ischemia and hypoxia, followed by sight threatening pathologic neovascularization in the second phase. Previously we found that Sirtuin1 (Sirt1), a metabolically dependent protein deacetylase, regulates vascular regeneration in a mouse model of oxygen-induced proliferative retinopathy (OIR), as neuronal depletion of Sirt1 in retina worsens retinopathy. In this study we assessed whether over-expression of Sirtuin1 in retinal neurons and vessels achieved by crossing Sirt1 over-expressing flox mice with Nestin-Cre mice or Tie2-Cre mice, respectively, may protect against retinopathy. We found that over-expression of Sirt1 in Nestin expressing retinal neurons does not impact vaso-obliteration or pathologic neovascularization in OIR, nor does it influence neuronal degeneration in OIR. Similarly, increased expression of Sirt1 in Tie2 expressing vascular endothelial cells and monocytes/macrophages does not protect retinal vessels in OIR. In addition to the genetic approaches, dietary supplement with Sirt1 activators, resveratrol or SRT1720, were fed to wild type mice with OIR. Neither treatment showed significant vaso-protective effects in retinopathy. Together these results indicate that although endogenous Sirt1 is important as a stress-induced protector in retinopathy, over-expression of Sirt1 or treatment with small molecule activators at the examined doses do not provide additional protection against retinopathy in mice. Further studies are needed to examine in depth whether increasing levels of Sirt1 may serve as a potential therapeutic approach to treat or prevent retinopathy. PMID:24416337

Sirtuin1 over-expression does not impact retinal vascular and neuronal degeneration in a mouse model of oxygen-induced retinopathy.

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Michan, Shaday; Juan, Aimee M; Hurst, Christian G; Cui, Zhenghao; Evans, Lucy P; Hatton, Colman J; Pei, Dorothy T; Ju, Meihua; Sinclair, David A; Smith, Lois E H; Chen, Jing

2014-01-01

Proliferative retinopathy is a leading cause of blindness, including retinopathy of prematurity (ROP) in children and diabetic retinopathy in adults. Retinopathy is characterized by an initial phase of vessel loss, leading to tissue ischemia and hypoxia, followed by sight threatening pathologic neovascularization in the second phase. Previously we found that Sirtuin1 (Sirt1), a metabolically dependent protein deacetylase, regulates vascular regeneration in a mouse model of oxygen-induced proliferative retinopathy (OIR), as neuronal depletion of Sirt1 in retina worsens retinopathy. In this study we assessed whether over-expression of Sirtuin1 in retinal neurons and vessels achieved by crossing Sirt1 over-expressing flox mice with Nestin-Cre mice or Tie2-Cre mice, respectively, may protect against retinopathy. We found that over-expression of Sirt1 in Nestin expressing retinal neurons does not impact vaso-obliteration or pathologic neovascularization in OIR, nor does it influence neuronal degeneration in OIR. Similarly, increased expression of Sirt1 in Tie2 expressing vascular endothelial cells and monocytes/macrophages does not protect retinal vessels in OIR. In addition to the genetic approaches, dietary supplement with Sirt1 activators, resveratrol or SRT1720, were fed to wild type mice with OIR. Neither treatment showed significant vaso-protective effects in retinopathy. Together these results indicate that although endogenous Sirt1 is important as a stress-induced protector in retinopathy, over-expression of Sirt1 or treatment with small molecule activators at the examined doses do not provide additional protection against retinopathy in mice. Further studies are needed to examine in depth whether increasing levels of Sirt1 may serve as a potential therapeutic approach to treat or prevent retinopathy.

Tumor Targeting via Sialic Acid: [68Ga]DOTA-en-pba as a New Tool for Molecular Imaging of Cancer with PET.

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Tsoukalas, Charalambos; Geninatti-Crich, Simonetta; Gaitanis, Anastasios; Tsotakos, Theodoros; Paravatou-Petsotas, Maria; Aime, Silvio; Jiménez-Juárez, Rogelio; Anagnostopoulos, Constantinos D; Djanashvili, Kristina; Bouziotis, Penelope

2018-02-20

The aim of this study was to demonstrate the potential of Ga-68-labeled macrocycle (DOTA-en-pba) conjugated with phenylboronic vector for tumor recognition by positron emission tomography (PET), based on targeting of the overexpressed sialic acid (Sia). The imaging reporter DOTA-en-pba was synthesized and labeled with Ga-68 at high efficiency. Cell binding assay on Mel-C and B16-F10 melanoma cells was used to evaluate melanin production and Sia overexpression to determine the best model for demonstrating the capability of [ 68 Ga]DOTA-en-pba to recognize tumors. The in vivo PET imaging was done with B16-F10 tumor-bearing SCID mice injected with [ 68 Ga]DOTA-en-pba intravenously. Tumor, blood, and urine metabolites were assessed to evaluate the presence of a targeting agent. The affinity of [ 68 Ga]DOTA-en-pba to Sia was demonstrated on B16-F10 melanoma cells, after the production of melanin as well as Sia overexpression was proved to be up to four times higher in this cell line compared to that in Mel-C cells. Biodistribution studies in B16-F10 tumor-bearing SCID mice showed blood clearance at the time points studied, while uptake in the tumor peaked at 60 min post-injection (6.36 ± 2.41 % ID/g). The acquired PET images were in accordance with the ex vivo biodistribution results. Metabolite assessment on tumor, blood, and urine samples showed that [ 68 Ga]DOTA-en-pba remains unmetabolized up to at least 60 min post-injection. Our work is the first attempt for in vivo imaging of cancer by targeting overexpression of sialic acid on cancer cells with a radiotracer in PET.

Endothelium-targeted overexpression of heat shock protein 27 ameliorates blood–brain barrier disruption after ischemic brain injury

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Jiang, Xiaoyan; Zhang, Lili; Pu, Hongjian; Hu, Xiaoming; Zhang, Wenting; Cai, Wei; Gao, Yanqin; Leak, Rehana K.; Keep, Richard F.; Bennett, Michael V. L.; Chen, Jun

2017-01-01

The damage borne by the endothelial cells (ECs) forming the blood–brain barrier (BBB) during ischemic stroke and other neurological conditions disrupts the structure and function of the neurovascular unit and contributes to poor patient outcomes. We recently reported that structural aberrations in brain microvascular ECs—namely, uncontrolled actin polymerization and subsequent disassembly of junctional proteins, are a possible cause of the early onset BBB breach that arises within 30–60 min of reperfusion after transient focal ischemia. Here, we investigated the role of heat shock protein 27 (HSP27) as a direct inhibitor of actin polymerization and protectant against BBB disruption after ischemia/reperfusion (I/R). Using in vivo and in vitro models, we found that targeted overexpression of HSP27 specifically within ECs—but not within neurons—ameliorated BBB impairment 1–24 h after I/R. Mechanistically, HSP27 suppressed I/R-induced aberrant actin polymerization, stress fiber formation, and junctional protein translocation in brain microvascular ECs, independent of its protective actions against cell death. By preserving BBB integrity after I/R, EC-targeted HSP27 overexpression attenuated the infiltration of potentially destructive neutrophils and macrophages into brain parenchyma, thereby improving long-term stroke outcome. Notably, early poststroke administration of HSP27 attached to a cell-penetrating transduction domain (TAT-HSP27) rapidly elevated HSP27 levels in brain microvessels and ameliorated I/R-induced BBB disruption and subsequent neurological deficits. Thus, the present study demonstrates that HSP27 can function at the EC level to preserve BBB integrity after I/R brain injury. HSP27 may be a therapeutic agent for ischemic stroke and other neurological conditions involving BBB breakdown. PMID:28137866

Enzyme replacement therapy for murine hypophosphatasia.

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Millán, José Luis; Narisawa, Sonoko; Lemire, Isabelle; Loisel, Thomas P; Boileau, Guy; Leonard, Pierre; Gramatikova, Svetlana; Terkeltaub, Robert; Camacho, Nancy Pleshko; McKee, Marc D; Crine, Philippe; Whyte, Michael P

2008-06-01

Hypophosphatasia (HPP) is the inborn error of metabolism that features rickets or osteomalacia caused by loss-of-function mutation(s) within the gene that encodes the tissue-nonspecific isozyme of alkaline phosphatase (TNALP). Consequently, natural substrates for this ectoenzyme accumulate extracellulary including inorganic pyrophosphate (PPi), an inhibitor of mineralization, and pyridoxal 5'-phosphate (PLP), a co-factor form of vitamin B6. Babies with the infantile form of HPP often die with severe rickets and sometimes hypercalcemia and vitamin B6-dependent seizures. There is no established medical treatment. Human TNALP was bioengineered with the C terminus extended by the Fc region of human IgG for one-step purification and a deca-aspartate sequence (D10) for targeting to mineralizing tissue (sALP-FcD10). TNALP-null mice (Akp2-/-), an excellent model for infantile HPP, were treated from birth using sALP-FcD10. Short-term and long-term efficacy studies consisted of once daily subcutaneous injections of 1, 2, or 8.2 mg/kg sALP-FcD10 for 15, 19, and 15 or 52 days, respectively. We assessed survival and growth rates, circulating levels of sALP-FcD10 activity, calcium, PPi, and pyridoxal, as well as skeletal and dental manifestations using radiography, microCT, and histomorphometry. Akp2-/- mice receiving high-dose sALP-FcD10 grew normally and appeared well without skeletal or dental disease or epilepsy. Plasma calcium, PPi, and pyridoxal concentrations remained in their normal ranges. We found no evidence of significant skeletal or dental disease. Enzyme replacement using a bone-targeted, recombinant form of human TNALP prevents infantile HPP in Akp2-/- mice.

Interventions Targeting Glucocorticoid-Krüppel-like Factor 15-Branched-Chain Amino Acid Signaling Improve Disease Phenotypes in Spinal Muscular Atrophy Mice

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Lisa M. Walter

2018-05-01

Full Text Available The circadian glucocorticoid-Krüppel-like factor 15-branched-chain amino acid (GC-KLF15-BCAA signaling pathway is a key regulatory axis in muscle, whose imbalance has wide-reaching effects on metabolic homeostasis. Spinal muscular atrophy (SMA is a neuromuscular disorder also characterized by intrinsic muscle pathologies, metabolic abnormalities and disrupted sleep patterns, which can influence or be influenced by circadian regulatory networks that control behavioral and metabolic rhythms. We therefore set out to investigate the contribution of the GC-KLF15-BCAA pathway in SMA pathophysiology of Taiwanese Smn−/−;SMN2 and Smn2B/− mouse models. We thus uncover substantial dysregulation of GC-KLF15-BCAA diurnal rhythmicity in serum, skeletal muscle and metabolic tissues of SMA mice. Importantly, modulating the components of the GC-KLF15-BCAA pathway via pharmacological (prednisolone, genetic (muscle-specific Klf15 overexpression and dietary (BCAA supplementation interventions significantly improves disease phenotypes in SMA mice. Our study highlights the GC-KLF15-BCAA pathway as a contributor to SMA pathogenesis and provides several treatment avenues to alleviate peripheral manifestations of the disease. The therapeutic potential of targeting metabolic perturbations by diet and commercially available drugs could have a broader implementation across other neuromuscular and metabolic disorders characterized by altered GC-KLF15-BCAA signaling. Keywords: Spinal muscular atrophy, KLF15, Glucocorticoids, Branched-chain amino acids, Metabolism, Therapy

Cardiac-specific overexpression of catalase attenuates lipopolysaccharide-induced myocardial contractile dysfunction: role of autophagy.

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Turdi, Subat; Han, Xuefeng; Huff, Anna F; Roe, Nathan D; Hu, Nan; Gao, Feng; Ren, Jun

2012-09-15

Lipopolysaccharide (LPS) from gram-negative bacteria is a major initiator of sepsis, leading to cardiovascular collapse. Accumulating evidence has indicated a role of reactive oxygen species (ROS) in cardiovascular complications in sepsis. This study was designed to examine the effect of cardiac-specific overexpression of catalase in LPS-induced cardiac contractile dysfunction and the underlying mechanism(s) with a focus on autophagy. Catalase transgenic and wild-type FVB mice were challenged with LPS (6 mg/kg) and cardiac function was evaluated. Levels of oxidative stress, autophagy, apoptosis, and protein damage were examined using fluorescence microscopy, Western blot, TUNEL assay, caspase-3 activity, and carbonyl formation. A Kaplan-Meier curve was constructed for survival after LPS treatment. Our results revealed a lower mortality in catalase mice compared with FVB mice after LPS challenge. LPS injection led to depressed cardiac contractile capacity as evidenced by echocardiography and cardiomyocyte contractile function, the effect of which was ablated by catalase overexpression. LPS treatment induced elevated TNF-α level, autophagy, apoptosis (TUNEL, caspase-3 activation, cleaved caspase-3), production of ROS and O(2)(-), and protein carbonyl formation, the effects of which were significantly attenuated by catalase overexpression. Electron microscopy revealed focal myocardial damage characterized by mitochondrial injury after LPS treatment, which was less severe in catalase mice. Interestingly, LPS-induced cardiomyocyte contractile dysfunction was prevented by the antioxidant N-acetylcysteine and the autophagy inhibitor 3-methyladenine. Taken together, our data revealed that catalase protects against LPS-induced cardiac dysfunction and mortality, which may be associated with inhibition of oxidative stress and autophagy. Copyright © 2012 Elsevier Inc. All rights reserved.

Targeted microbubbles for imaging tumor angiogenesis: assessment of whole-body biodistribution with dynamic micro-PET in mice

DEFF Research Database (Denmark)

Willmann, Jürgen K; Cheng, Zhen; Davis, Corrine

2008-01-01

To evaluate in vivo whole-body biodistribution of microbubbles (MBs) targeted to tumor angiogenesis-related vascular endothelial growth factor (VEGF) receptor 2 (VEGFR2) by using dynamic micro-positron emission tomography (PET) in living mice.......To evaluate in vivo whole-body biodistribution of microbubbles (MBs) targeted to tumor angiogenesis-related vascular endothelial growth factor (VEGF) receptor 2 (VEGFR2) by using dynamic micro-positron emission tomography (PET) in living mice....

Characterization of amyloid beta peptides from brain extracts of transgenic mice overexpressing the London mutant of human amyloid precursor protein.

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Pype, Stefan; Moechars, Dieder; Dillen, Lieve; Mercken, Marc

2003-02-01

Alzheimer's disease (AD) is marked by the presence of neurofibrillary tangles and amyloid plaques in the brain of patients. To study plaque formation, we report on further quantitative and qualitative analysis of human and mouse amyloid beta peptides (Abeta) from brain extracts of transgenic mice overexpressing the London mutant of human amyloid precursor protein (APP). Using enzyme-linked immunosorbant assays (ELISAs) specific for either human or rodent Abeta, we found that the peptides from both species aggregated to form plaques. The ratios of deposited Abeta1-42/1-40 were in the order of 2-3 for human and 8-9 for mouse peptides, indicating preferential deposition of Abeta42. We also determined the identity and relative levels of other Abeta variants present in protein extracts from soluble and insoluble brain fractions. This was done by combined immunoprecipitation and mass spectrometry (IP/MS). The most prominent peptides truncated either at the carboxyl- or the amino-terminus were Abeta1-38 and Abeta11-42, respectively, and the latter was strongly enriched in the extracts of deposited peptides. Taken together, our data indicate that plaques of APP-London transgenic mice consist of aggregates of multiple human and mouse Abeta variants, and the human variants that we identified were previously detected in brain extracts of AD patients.

Parvalbumin overexpression alters immune-mediated increases in intracellular calcium, and delays disease onset in a transgenic model of familial amyotrophic lateral sclerosis

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Beers, D. R.; Ho, B. K.; Siklos, L.; Alexianu, M. E.; Mosier, D. R.; Mohamed, A. H.; Otsuka, Y.; Kozovska, M. E.; McAlhany, R. E.; Smith, R. G.;

MicroRNA-375 inhibits colorectal cancer growth by targeting PIK3CA

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Wang, Yihui [Department of Colorectal Surgery, The Third Affiliated Hospital of Harbin Medical University, 150 Haping Road, 150081 Harbin (China); Tang, Qingchao [Cancer Center, The Second Affiliated Hospital of Harbin Medical University, 246 Xuefu Road, 150086 Harbin (China); Li, Mingqi; Jiang, Shixiong [Department of Colorectal Surgery, The Third Affiliated Hospital of Harbin Medical University, 150 Haping Road, 150081 Harbin (China); Wang, Xishan, E-mail: wxshan12081@163.com [Cancer Center, The Second Affiliated Hospital of Harbin Medical University, 246 Xuefu Road, 150086 Harbin (China)

2014-02-07

Highlights: • miR-375 is downregulated in colorectal cancer cell lines and tissues. • miR-375 inhibits colorectal cancer cell growth by targeting PIK3CA. • miR-375 inhibits colorectal cancer cell growth in xenograft nude mice model. - Abstract: Colorectal cancer (CRC) is the second most common cause of death from cancer. MicroRNAs (miRNAs) represent a class of small non-coding RNAs that control gene expression by triggering RNA degradation or interfering with translation. Aberrant miRNA expression is involved in human disease including cancer. Herein, we showed that miR-375 was frequently down-regulated in human colorectal cancer cell lines and tissues when compared to normal human colon tissues. PIK3CA was identified as a potential miR-375 target by bioinformatics. Overexpression of miR-375 in SW480 and HCT15 cells reduced PIK3CA protein expression. Subsequently, using reporter constructs, we showed that the PIK3CA untranslated region (3′-UTR) carries the directly binding site of miR-375. Additionally, miR-375 suppressed CRC cell proliferation and colony formation and led to cell cycle arrest. Furthermore, miR-375 overexpression resulted in inhibition of phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. SiRNA-mediated silencing of PIK3CA blocked the inhibitory effect of miR-375 on CRC cell growth. Lastly, we found overexpressed miR-375 effectively repressed tumor growth in xenograft animal experiments. Taken together, we propose that overexpression of miR-375 may provide a selective growth inhibition for CRC cells by targeting PI3K/Akt signaling pathway.

Overexpression of TOR (target of rapamycin) inhibits cell proliferation in Dictyostelium discoideum.

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Swer, Pynskhem Bok; Mishra, Himanshu; Lohia, Rakhee; Saran, Shweta

2016-05-01

TOR (target of rapamycin) protein kinase acts as a central controller of cell growth and development of an organism. Present study was undertaken to find the expression pattern and role of TOR during growth and development of Dictyostelium discoideum. Failures to generate either knockout and/or knockdown mutants indicate that interference with its levels led to cellular defects. Thus, the effects of TOR (DDB_G0281569) overexpression specifically, cells expressing Dd(Δ211-TOR)-Eyfp mutant was analyzed. Elevated expression of (Δ211-TOR)-Eyfp reduced both cell size and cell proliferation. DdTOR was found to be closer to fungus. mRNA level of TOR was found maximally in the freshly starved/aggregate cells that gradually declined. This was also strengthened by the expression patterns observed by in situ and the analysis of β-galactosidase reporter driven by the putative TOR promoter. The TOR protein was found to be highest at the aggregate stage. The fusion protein, (Δ211-TOR)-Eyfp was localized to the cell membrane, cytosol, and the nucleus. We suggest, DdTOR to be an essential protein and high TOR expression inhibits cell proliferation. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dwarfism and early death in mice lacking C-type natriuretic peptide

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Chusho, Hideki; Tamura, Naohisa; Ogawa, Yoshihiro; Yasoda, Akihiro; Suda, Michio; Miyazawa, Takashi; Nakamura, Kenji; Nakao, Kazuki; Kurihara, Tatsuya; Komatsu, Yasato; Itoh, Hiroshi; Tanaka, Kiyoshi; Saito, Yoshihiko; Katsuki, Motoya; Nakao, Kazuwa

2001-01-01

Longitudinal bone growth is determined by endochondral ossification that occurs as chondrocytes in the cartilaginous growth plate undergo proliferation, hypertrophy, cell death, and osteoblastic replacement. The natriuretic peptide family consists of three structurally related endogenous ligands, atrial, brain, and C-type natriuretic peptides (ANP, BNP, and CNP), and is thought to be involved in a variety of homeostatic processes. To investigate the physiological significance of CNP in vivo, we generated mice with targeted disruption of CNP (Nppc−/− mice). The Nppc−/− mice show severe dwarfism as a result of impaired endochondral ossification. They are all viable perinatally, but less than half can survive during postnatal development. The skeletal phenotypes are histologically similar to those seen in patients with achondroplasia, the most common genetic form of human dwarfism. Targeted expression of CNP in the growth plate chondrocytes can rescue the skeletal defect of Nppc−/− mice and allow their prolonged survival. This study demonstrates that CNP acts locally as a positive regulator of endochondral ossification in vivo and suggests its pathophysiological and therapeutic implication in some forms of skeletal dysplasia. PMID:11259675

MS-analysis of SILAC-labeled MYC-driven B lymphoma cells overexpressing miR-17-19b

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Marija Mihailovich

2016-06-01

Full Text Available Micro RNAs (miRNAs are small non-coding RNAs, which dampen gene expression by repressing translation and/or inducing degradation of target-mRNAs. Although the role of miR-17-19b (a truncated version of miR-17-92 cluster is well documented in MYC-driven B cell lymphomagenesis, little is known about the function of the cluster in the maintenance of full-blown lymphomas. We employed SILAC-based quantitative proteomics to identify miR-17-19b targets upon a mild overexpression of the cluster in B cell lymphomas, established from λ-MYC transgenic mice. The proteomics data described in detail in this study, whose follow up analysis with MaxQuant algorithm is part of the recent publication (Mihailovich et al., 2015 [1], are deposited to the ProteomeXchange Consortium via the PRIDE partner repository, with the accession code PRIDE: http://www.ebi.ac.uk/pride/archive/projects/PXD002810.

MiR-124 suppresses cell proliferation in hepatocellular carcinoma by targeting PIK3CA

International Nuclear Information System (INIS)

Lang, Qingbo; Ling, Changquan

2012-01-01

Highlights: ► PIK3CA is a novel target of miR-124 in HepG2 cells. ► MiR-124 suppresses cell proliferation by downregulating PIK3CA expression. ► MiR-124 regulates the PI3K/Akt pathway in HepG2 cells. ► MiR-124 overexpression inhibits the tumorigenesis in nude mice. -- Abstract: MicroRNAs (miRNAs) have crucial roles in the development and progression of human cancers, including hepatocellular carcinoma (HCC). Recent studies have shown that microRNA-124 (miR-124) was downregulated in HCC; however, the underlying mechanisms by which miR-124 suppresses tumorigenesis in HCC are largely unknown. In this study, we report that phosphoinositide 3-kinase catalytic subunit alpha (PIK3CA) is a novel target of miR-124 in HepG2 cells. Overexpression of miR-124 resulted in decreased expression of PIK3CA at both mRNA and protein levels. We found that miR-124 overexpression markedly suppressed cell proliferation by inducing G1-phase cell-cycle arrest in vitro. Consistent with the restoring miR-124 expression, PIK3CA knockdown suppressed cell proliferation, whereas overexpression of PIK3CA abolished the suppressive effect of miR-124. Mechanistic studies showed that miR-124-mediated reduction of PIK3CA resulted in suppression of PI3K/Akt pathway. The expressions of Akt and mTOR, key components of the PI3K/Akt pathway, were all downregulated. Moreover, we found overexpressed miR-124 effectively repressed tumor growth in xenograft animal experiments. Taken together, our results demonstrate that miR-124 functions as a growth-suppressive miRNA and plays an important role in inhibiting the tumorigenesis through targeting PIK3CA.

MiR-124 suppresses cell proliferation in hepatocellular carcinoma by targeting PIK3CA

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Lang, Qingbo [Department of Traditional Chinese Medicine, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); Ling, Changquan, E-mail: lingchangquan@hotmail.com [Department of Traditional Chinese Medicine, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China)

2012-09-21

Highlights: Black-Right-Pointing-Pointer PIK3CA is a novel target of miR-124 in HepG2 cells. Black-Right-Pointing-Pointer MiR-124 suppresses cell proliferation by downregulating PIK3CA expression. Black-Right-Pointing-Pointer MiR-124 regulates the PI3K/Akt pathway in HepG2 cells. Black-Right-Pointing-Pointer MiR-124 overexpression inhibits the tumorigenesis in nude mice. -- Abstract: MicroRNAs (miRNAs) have crucial roles in the development and progression of human cancers, including hepatocellular carcinoma (HCC). Recent studies have shown that microRNA-124 (miR-124) was downregulated in HCC; however, the underlying mechanisms by which miR-124 suppresses tumorigenesis in HCC are largely unknown. In this study, we report that phosphoinositide 3-kinase catalytic subunit alpha (PIK3CA) is a novel target of miR-124 in HepG2 cells. Overexpression of miR-124 resulted in decreased expression of PIK3CA at both mRNA and protein levels. We found that miR-124 overexpression markedly suppressed cell proliferation by inducing G1-phase cell-cycle arrest in vitro. Consistent with the restoring miR-124 expression, PIK3CA knockdown suppressed cell proliferation, whereas overexpression of PIK3CA abolished the suppressive effect of miR-124. Mechanistic studies showed that miR-124-mediated reduction of PIK3CA resulted in suppression of PI3K/Akt pathway. The expressions of Akt and mTOR, key components of the PI3K/Akt pathway, were all downregulated. Moreover, we found overexpressed miR-124 effectively repressed tumor growth in xenograft animal experiments. Taken together, our results demonstrate that miR-124 functions as a growth-suppressive miRNA and plays an important role in inhibiting the tumorigenesis through targeting PIK3CA.

Ultrasound-targeted hepatic delivery of factor IX in hemophiliac mice.

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Anderson, C D; Moisyadi, S; Avelar, A; Walton, C B; Shohet, R V

2016-06-01

Ultrasound-targeted microbubble destruction (UTMD) was used to direct the delivery of plasmid and transposase-based vectors encoding human factor IX (hFIX) to the livers of hemophilia B (FIX-/-) mice. The DNA vectors were incorporated into cationic lipid microbubbles, injected intravenously, and transfected into hepatocytes by acoustic cavitation of the bubbles as they transited the liver. Ultrasound parameters were identified that produced transfection of hepatocytes in vivo without substantial damage or bleeding in the livers of the FIX-deficient mice. These mice were treated with a conventional expression plasmid, or one containing a piggyBac transposon construct, and hFIX levels in the plasma and liver were evaluated at multiple time points after UTMD. We detected hFIX in the plasma by western blotting from mice treated with either plasmid during the 12 days after UTMD, and in the hepatocytes of treated livers by immunofluorescence. Reductions in clotting time and improvements in the percentage of FIX activity were observed for both plasmids, conventional (4.15±1.98%), and transposon based (2.70±.75%), 4 to 5 days after UTMD compared with untreated FIX (-/-) control mice (0.92±0.78%) (P=0.001 and P=0.012, respectively). Reduced clotting times persisted for both plasmids 12 days after treatment (reflecting percentage FIX activity of 3.12±1.56%, P=0.02 and 3.08±0.10%, P=0.001, respectively). Clotting times from an additional set of mice treated with pmGENIE3-hFIX were evaluated for long-term effects and demonstrated a persistent reduction in average clotting time 160 days after a single treatment. These data suggest that UTMD could be a minimally invasive, nonviral approach to enhance hepatic FIX expression in patients with hemophilia.

ESC-Derived BDNF-Overexpressing Neural Progenitors Differentially Promote Recovery in Huntington's Disease Models by Enhanced Striatal Differentiation

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Tina Zimmermann

2016-10-01

Full Text Available Huntington's disease (HD is characterized by fatal motoric failures induced by loss of striatal medium spiny neurons. Neuronal cell death has been linked to impaired expression and axonal transport of the neurotrophin BDNF (brain-derived neurotrophic factor. By transplanting embryonic stem cell-derived neural progenitors overexpressing BDNF, we combined cell replacement and BDNF supply as a potential HD therapy approach. Transplantation of purified neural progenitors was analyzed in a quinolinic acid (QA chemical and two genetic HD mouse models (R6/2 and N171-82Q on the basis of distinct behavioral parameters, including CatWalk gait analysis. Explicit rescue of motor function by BDNF neural progenitors was found in QA-lesioned mice, whereas genetic mouse models displayed only minor improvements. Tumor formation was absent, and regeneration was attributed to enhanced neuronal and striatal differentiation. In addition, adult neurogenesis was preserved in a BDNF-dependent manner. Our findings provide significant insight for establishing therapeutic strategies for HD to ameliorate neurodegenerative symptoms.

Mice with GFAP-targeted loss of neurofibromin demonstrate increased axonal MET expression with aging.

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Su, Weiping; Xing, Rubing; Guha, Abhijit; Gutmann, David H; Sherman, Larry S

2007-05-01

Neurofibromatosis 1 (NF1) is a common genetic disease that predisposes patients to peripheral nerve tumors and central nervous system (CNS) abnormalities including low-grade astrocytomas and cognitive disabilities. Using mice with glial fibrillary acidic protein (GFAP)-targeted Nf1 loss (Nf1(GFAP)CKO mice), we found that Nf1(-/-) astrocytes proliferate faster and are more invasive than wild-type astrocytes. In light of our previous finding that aberrant expression of the MET receptor tyrosine kinase contributes to the invasiveness of human NF1-associated malignant peripheral nerve sheath tumors, we sought to determine whether MET expression is aberrant in the brains of Nf1 mutant mice. We found that Nf1(-/-) astrocytes express slightly more MET than wild-type cells in vitro, but do not express elevated MET in situ. However, fiber tracts containing myelinated axons in the hippocampus, midbrain, cerebral cortex, and cerebellum express higher than normal levels of MET in older (> or =6 months) Nf1(GFAP)CKO mice. Both Nf1(GFAP)CKO and wild-type astrocytes induced MET expression in neurites of wild-type hippocampal neurons in vitro, suggesting that astrocyte-derived signals may induce MET in Nf1 mutant mice. Because the Nf1 gene product functions as a RAS GTPase, we examined MET expression in the brains of mice with GFAP-targeted constitutively active forms of RAS. MET was elevated in axonal fiber tracts in mice with active K-RAS but not H-RAS. Collectively, these data suggest that loss of Nf1 in either astrocytes or GFAP(+) neural progenitor cells results in increased axonal MET expression, which may contribute to the CNS abnormalities in children and adults with NF1. (c) 2007 Wiley-Liss, Inc.

Estradiol replacement enhances fear memory formation, impairs extinction and reduces COMT expression levels in the hippocampus of ovariectomized female mice.

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McDermott, Carmel M; Liu, Dan; Ade, Catherine; Schrader, Laura A

2015-02-01

Females experience depression, posttraumatic stress disorder (PTSD), and anxiety disorders at approximately twice the rate of males, but the mechanisms underlying this difference remain undefined. The effect of sex hormones on neural substrates presents a possible mechanism. We investigated the effect of ovariectomy at two ages, before puberty and in adulthood, and 17β-estradiol (E2) replacement administered chronically in drinking water on anxiety level, fear memory formation, and extinction. Based on previous studies, we hypothesized that estradiol replacement would impair fear memory formation and enhance extinction rate. Females, age 4 weeks and 10 weeks, were divided randomly into 4 groups; sham surgery, OVX, OVX+low E2 (200nM), and OVX+high E2 (1000nM). Chronic treatment with high levels of E2 significantly increased anxiety levels measured in the elevated plus maze. In both age groups, high levels of E2 significantly increased contextual fear memory but had no effect on cued fear memory. In addition, high E2 decreased the rate of extinction in both ages. Finally, catechol-O-methyltransferase (COMT) is important for regulation of catecholamine levels, which play a role in fear memory formation and extinction. COMT expression in the hippocampus was significantly reduced by high E2 replacement, implying increased catecholamine levels in the hippocampus of high E2 mice. These results suggest that estradiol enhanced fear memory formation, and inhibited fear memory extinction, possibly stabilizing the fear memory in female mice. This study has implications for a neurobiological mechanism for PTSD and anxiety disorders. Copyright © 2014 Elsevier Inc. All rights reserved.

Tumor-targeting magnetic lipoplex delivery of short hairpin RNA suppresses IGF-1R overexpression of lung adenocarcinoma A549 cells in vitro and in vivo.

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Wang, Chunmao; Ding, Chao; Kong, Minjian; Dong, Aiqiang; Qian, Jianfang; Jiang, Daming; Shen, Zhonghua

2011-07-08

Liposomal magnetofection potentiates gene transfection by applying a magnetic field to concentrate magnetic lipoplexes onto target cells. Magnetic lipoplexes are self-assembling ternary complexes of cationic lipids with plasmid DNA associated with superparamagnetic iron oxide nanoparticles (SPIONs). Type1 insulin-like growth factor receptor (IGF-1R), an important oncogene, is frequently overexpressed in lung cancer and mediates cancer cell proliferation and tumor growth. In this study, we evaluated the transfection efficiency (percentage of transfected cells) and therapeutic potential (potency of IGF-1R knockdown) of liposomal magnetofection of plasmids expressing GFP and shRNAs targeting IGF-1R (pGFPshIGF-1Rs) in A549 cells and in tumor-bearing mice as compared to lipofection using Lipofectamine 2000. Liposomal magnetofection provided a threefold improvement in transgene expression over lipofection and transfected up to 64.1% of A549 cells in vitro. In vitro, IGF-1R specific-shRNA transfected by lipofection inhibited IGF-1R protein by 56.1±6% and by liposomal magnetofection by 85.1±3%. In vivo delivery efficiency of the pGFPshIGF-1R plasmid into the tumor was significantly higher in the liposomal magnetofection group than in the lipofection group. In vivo IGF-1R specific-shRNA by lipofection inhibited IGF-1R protein by an average of 43.8±5.3%; that by liposomal magnetofection inhibited IGF-1R protein by 43.4±5.7%, 56.3±9.6%, and 72.2±6.8%, at 24, 48, and 72 h, respectively, after pGFPshIGF-1R injection. Our findings indicate that liposomal magnetofection may be a promising method that allows the targeting of gene therapy to lung cancer. Copyright © 2011 Elsevier Inc. All rights reserved.

Growth hormone abolishes beneficial effects of calorie restriction in long-lived Ames dwarf mice.

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Gesing, Adam; Al-Regaiey, Khalid A; Bartke, Andrzej; Masternak, Michal M

2014-10-01

Disruption of the growth hormone (GH) axis promotes longevity and delays aging. In contrast, GH over-expression may lead to accelerated aging and shorter life. Calorie restriction (CR) improves insulin sensitivity and may extend lifespan. Long-lived Ames dwarf (df/df) mice have additional extension of longevity when subjected to 30% CR. The aim of the study was to assess effects of CR or GH replacement therapy separately and as a combined (CR+GH) treatment in GH-deficient df/df and normal mice, on selected metabolic parameters (e.g., insulin, glucose, cholesterol), insulin signaling components (e.g., insulin receptor [IR] β-subunit, phosphorylated form of IR [IR pY1158], protein kinase C ζ/λ [p-PKCζ/λ] and mTOR [p-mTOR]), transcription factor p-CREB, and components of the mitogen-activated protein kinase (MAPK) signaling (p-ERK1/2, p-p38), responsible for cell proliferation, differentiation and survival. CR decreased plasma levels of insulin, glucose, cholesterol and leptin, and increased hepatic IR β-subunit and IR pY1158 levels as well as IR, IRS-1 and GLUT-2 gene expression compared to ad libitum feeding, showing a significant beneficial diet intervention effect. Moreover, hepatic protein levels of p-PKCζ/λ, p-mTOR and p-p38 decreased, and p-CREB increased in CR mice. On the contrary, GH increased levels of glucose, cholesterol and leptin in plasma, and p-mTOR or p-p38 in livers, and decreased plasma adiponectin and hepatic IR β-subunit compared to saline treatment. There were no GH effects on adiponectin in N mice. Moreover, GH replacement therapy did not affect IR, IRS-1 and GLUT-2 gene expression. GH treatment abolishes the beneficial effects of CR; it may suggest an important role of GH-IGF1 axis in mediating the CR action. Suppressed somatotrophic signaling seems to predominate over GH replacement therapy in the context of the examined parameters and signaling pathways. Copyright © 2014 Elsevier Inc. All rights reserved.

A decrease in hepatic microRNA-9 expression impairs gluconeogenesis by targeting FOXO1 in obese mice.

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Yan, Caifeng; Chen, Jinfeng; Li, Min; Xuan, Wenying; Su, Dongming; You, Hui; Huang, Yujie; Chen, Nuoqi; Liang, Xiubin

2016-07-01

MicroRNA-9 (miR-9) is involved in the regulation of pancreatic beta cell function. However, its role in gluconeogenesis is still unclear. Our objective was to investigate the role of miR-9 in hepatic glucose production (HGP). MiR-9 expression was measured in livers of high-fat diet (HFD) mice and ob/ob mice. The methylation status of the miR-9-3 promoter regions in hepatocytes was determined by the methylation-specific PCR procedure. The binding activity of DNA methyltransferase (DNMT)1, DNMT3a and DNMT3b on the miR-9-3 promoter was detected by chromatin immunoprecipitation (ChIP) and quantitative real-time PCR assays. HGP was evaluated in vitro and in vivo. Glucose tolerance, insulin tolerance and pyruvate tolerance tests were also performed. Reduced miR-9 expression and hypermethylation of the miR-9-3 promoter were observed in the livers of obese mice. Further study showed that the binding of DNMT1, but not of DNMT3a and DNMT3b, to the miR-9-3 promoter was increased in hepatocytes from ob/ob mice. Knockdown of DNMT1 alleviated the decrease in hepatic miR-9 expression in vivo and in vitro. Overexpression of hepatic miR-9 improved insulin sensitivity in obese mice and inhibited HGP. In addition, deletion of hepatic miR-9 led to an increase in random and fasting blood glucose levels in lean mice. Importantly, silenced forkhead box O1 (FOXO1) expression reversed the gluconeogenesis and glucose production in hepatocytes induced by miR-9 deletion. Our observations suggest that the decrease in miR-9 expression contributes to an inappropriately activated gluconeogenesis in obese mice.

Hyperlipidemia and cutaneous abnormalities in transgenic mice overexpressing human apolipoprotein C1

NARCIS (Netherlands)

Jong, M. C.; Gijbels, M. J.; Dahlmans, V. E.; Gorp, P. J.; Koopman, S. J.; Ponec, M.; Hofker, M. H.; Havekes, L. M.

1998-01-01

Transgenic mice were generated with different levels of human apolipoprotein C1 (APOC1) expression in liver and skin. At 2 mo of age, serum levels of cholesterol, triglycerides (TG), and FFA were strongly elevated in APOC1 transgenic mice compared with wild-type mice. These elevated levels of serum

ErbB2 and NFκB overexpression as predictors of chemoradiation resistance and putative targets to overcome resistance in muscle-invasive bladder cancer.

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Fumitaka Koga

Full Text Available Radical cystectomy for muscle-invasive bladder cancer (MIBC patients frequently impairs their quality of life (QOL due to urinary diversion. To improve their QOL, a bladder-sparing alternative strategy using chemoradiation has been developed. In bladder-sparing protocols, complete response (CR to induction chemoradiation is a prerequisite for bladder preservation and favorable survival. Thus predicting chemoradiation resistance and overcoming it would increase individual MIBC patients' chances of bladder preservation. The aim of this study is to investigate putative molecular targets for treatment aimed at improving chemoradiation response. Expression levels of erbB2, NFκB, p53, and survivin were evaluated immunohistochemically in pretreatment biopsy samples from 35 MIBC patients in whom chemoradiation sensitivity had been pathologically evaluated in cystectomy specimens, and associations of these expression levels with chemoradiation sensitivity and cancer-specific survival (CSS were investigated. Of the 35 patients, 11 (31% achieved pathological CR, while tumors in the remaining 24 patients (69% were chemoradiation-resistant. Multivariate analysis identified erbB2 and NFκB overexpression and hydronephrosis as significant and independent risk factors for chemoradiation resistance with respective relative risks of 11.8 (P = 0.014, 15.4 (P = 0.024 and 14.3 (P = 0.038. The chemoradiation resistance rate was 88.5% for tumors overexpressing erbB2 and/or NFκB, but only 11.1% for those negative for both (P <0.0001. The 5-year CSS rate was 74% overall. Through multivariate analysis, overexpression of erbB2 and/or NFκB was identified as an independent risk factor for bladder cancer death with marginal significance (hazard ratio 21.5, P = 0.056 along with chemoradiation resistance (P = 0.003 and hydronephrosis (P = 0.018. The 5-year CSS rate for the 11 patients achieving pathological CR was 100%, while that for the 24 with

Development of ghrelin transgenic mice for elucidation of clinical implication of ghrelin.

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Aotani, Daisuke; Ariyasu, Hiroyuki; Shimazu-Kuwahara, Satoko; Shimizu, Yoshiyuki; Nomura, Hidenari; Murofushi, Yoshiteru; Kaneko, Kentaro; Izumi, Ryota; Matsubara, Masaki; Kanda, Hajime; Noguchi, Michio; Tanaka, Tomohiro; Kusakabe, Toru; Miyazawa, Takashi; Nakao, Kazuwa

2017-01-01

To elucidate the clinical implication of ghrelin, we have been trying to generate variable models of transgenic (Tg) mice overexpressing ghrelin. We generated Tg mice overexpressing des-acyl ghrelin in a wide variety of tissues under the control of β-actin promoter. While plasma des-acyl ghrelin level in the Tg mice was 44-fold greater than that of control mice, there was no differences in the plasma ghrelin level between des-acyl ghrelin Tg and the control mice. The des-acyl ghrelin Tg mice exhibited the lower body weight and the shorter body length due to modulation of GH-IGF-1 axis. We tried to generate Tg mice expressing a ghrelin analog, which possessed ghrelin-like activity (Trp 3 -ghrelin Tg mice). The plasma Trp 3 -ghrelin concentration in Trp 3 -ghrelin Tg mice was approximately 85-fold higher than plasma ghrelin (acylated ghrelin) concentration seen in the control mice. Because Trp 3 -ghrelin is approximately 24-fold less potent than ghrelin, the plasma Trp 3 -ghrelin concentration in Trp 3 -ghrelin Tg mice was calculated to have approximately 3.5-fold biological activity greater than that of ghrelin (acylated ghrelin) in the control mice. Trp 3 -ghrelin Tg mice did not show any phenotypes except for reduced insulin sensitivity in 1-year old. After the identification of ghrelin O-acyltransferase (GOAT), we generated doubly Tg mice overexpressing both mouse des-acyl ghrelin and mouse GOAT in the liver by cross-mating the two kinds of Tg mice. The plasma ghrelin concentration of doubly Tg mice was approximately 2-fold higher than that of the control mice. No apparent phenotypic changes in body weight and food intake were observed in doubly Tg mice. Further studies are ongoing in our laboratory to generate Tg mice with the increased plasma ghrelin level to a greater extent. The better understanding of physiological and pathophysiological significance of ghrelin from experiments using an excellent animal model may provide a new therapeutic approach for human

Enzyme Replacement Therapy for Murine Hypophosphatasia*

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Millán, José Luis; Narisawa, Sonoko; Lemire, Isabelle; Loisel, Thomas P; Boileau, Guy; Leonard, Pierre; Gramatikova, Svetlana; Terkeltaub, Robert; Camacho, Nancy Pleshko; McKee, Marc D; Crine, Philippe; Whyte, Michael P

2008-01-01

Introduction Hypophosphatasia (HPP) is the inborn error of metabolism that features rickets or osteomalacia caused by loss-of-function mutation(s) within the gene that encodes the tissue-nonspecific isozyme of alkaline phosphatase (TNALP). Consequently, natural substrates for this ectoenzyme accumulate extracellulary including inorganic pyrophosphate (PPi), an inhibitor of mineralization, and pyridoxal 5`-phosphate (PLP), a co-factor form of vitamin B6. Babies with the infantile form of HPP often die with severe rickets and sometimes hypercalcemia and vitamin B6-dependent seizures. There is no established medical treatment. Materials and Methods Human TNALP was bioengineered with the C terminus extended by the Fc region of human IgG for one-step purification and a deca-aspartate sequence (D10) for targeting to mineralizing tissue (sALP-FcD10). TNALP-null mice (Akp2−/−), an excellent model for infantile HPP, were treated from birth using sALP-FcD10. Short-term and long-term efficacy studies consisted of once daily subcutaneous injections of 1, 2, or 8.2 mg/kg sALP-FcD10 for 15, 19, and 15 or 52 days, respectively. We assessed survival and growth rates, circulating levels of sALP-FcD10 activity, calcium, PPi, and pyridoxal, as well as skeletal and dental manifestations using radiography, μCT, and histomorphometry. Results Akp2−/− mice receiving high-dose sALP-FcD10 grew normally and appeared well without skeletal or dental disease or epilepsy. Plasma calcium, PPi, and pyridoxal concentrations remained in their normal ranges. We found no evidence of significant skeletal or dental disease. Conclusions Enzyme replacement using a bone-targeted, recombinant form of human TNALP prevents infantile HPP in Akp2−/− mice. PMID:18086009

Muscle ERRγ mitigates Duchenne muscular dystrophy via metabolic and angiogenic reprogramming.

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Matsakas, Antonios; Yadav, Vikas; Lorca, Sabina; Narkar, Vihang

2013-10-01

Treatment of Duchenne muscular dystrophy (DMD) by replacing mutant dystrophin or restoring dystrophin-associated glycoprotein complex (DAG) has been clinically challenging. Instead, identifying and targeting muscle pathways deregulated in DMD will provide new therapeutic avenues. We report that the expression of nuclear receptor estrogen-related receptor-γ (ERRγ), and its metabolic and angiogenic targets are down-regulated (50-85%) in skeletal muscles of mdx mice (DMD model) vs. wild-type mice. Corelatively, oxidative myofibers, muscle vasculature, and exercise tolerance (33%) are decreased in mdx vs. wild-type mice. Overexpressing ERRγ selectively in the dystrophic muscles of the mdx mice restored metabolic and angiogenic gene expression compared with control mdx mice. Further, ERRγ enhanced muscle oxidative myofibers, vasculature, and blood flow (by 33-66%) and improved exercise tolerance (by 75%) in the dystrophic mice. Restoring muscle ERRγ pathway ameliorated muscle damage and also prevented DMD hallmarks of postexercise muscle damage, hypoxia, and fatigue in mdx mice. Notably, ERRγ did not restore sarcolemmal DAG complex, which is thus dispensable for antidystrophic effects of ERRγ. In summary, ERRγ-dependent metabolic and angiogenic gene program is defective in DMD, and we demonstrate that its restoration is a potential strategy for treating muscular dystrophy.

Mice with a targeted deletion of the tetranectin gene exhibit a spinal deformity

DEFF Research Database (Denmark)

Iba, K; Durkin, M E; Johnsen, L

2001-01-01

and muscle. To test the functional role of tetranectin directly, we have generated mice with a targeted disruption of the gene. We report that the tetranectin-deficient mice exhibit kyphosis, a type of spinal deformity characterized by an increased curvature of the thoracic spine. The kyphotic angles were...... in the morphology of the vertebrae. Histological analysis of the spines of these mice revealed an apparently asymmetric development of the growth plate and of the intervertebral disks of the vertebrae. In the most advanced cases, the growth plates appeared disorganized and irregular, with the disk material...... in tissue growth and remodeling. The tetranectin-deficient mouse is the first mouse model that resembles common human kyphotic disorders, which affect up to 8% of the population....

CtBP2 overexpression promotes tumor cell proliferation and invasion in gastric cancer and is associated with poor prognosis.

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Dai, Faxiang; Xuan, Yi; Jin, Jie-Jie; Yu, Shengjia; Long, Zi-Wen; Cai, Hong; Liu, Xiao-Wen; Zhou, Ye; Wang, Ya-Nong; Chen, Zhong; Huang, Hua

2017-04-25

C-terminal binding protein-2 (CtBP2), a transcriptional corepressor, has been reported to correlate with tumorigenesis and progression and predict a poor prognosis in several human cancers. However, few studies on CtBP2 in gastric cancer (GC) have been performed. In this research, we evaluated the correlations between CtBP2 expression and the clinicopathological characteristics, as well as prognosis of GC patients. The effects of silencing CtBP2 expression on GC cells biology activity were also assessed. The results showed that CtBP2 was overexpressed in GC tissues and closely correlated with poor differentiation, advanced tumor stage and poor prognosis in GC patients. CtBP2 induced epithelial-to-mesenchymal transition (EMT) and repressed PTEN to increase proliferation rate, migration, and invasion in GC cells. Silencing CtBP2 inhibited GC growth in nude mice model. In conclusion, CtBP2 is overexpressed in GC and may accelerate GC tumorigenesis and metastasis, which could represent an independent prognostic marker and promising therapeutic target for GC.

MET overexpression, gene amplification and relevant clinicopathological features in gastric adenocarcinoma.

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Zhang, Jing; Guo, Lei; Liu, Xiuyun; Li, Wenbin; Ying, Jianming

2017-02-07

This study was conducted to investigate the expression of MET in Chinese gastric adenocarcinoma cohort, the correlation between MET overexpression and clinical pathological features, HER2 expression and MET gene amplification. A total of 816 gastric adenocarcinoma patients were included and MET and HER2 immunohistochemical (IHC) staining were performed. IHC and dual-color silver in situ hybridization analysis were performed in the tissue microarrays, constructed from the 240 patients who were randomly selected. MET overexpression (IHC 3+) was observed in 6.0% (49/816) of the cohort. MET overexpression rate was higher in patients with poor prognostic factors, such as clinical stages III/IV (p =0.012) and pathologic stages T3/T4 (p =0.027). The HER2 overexpression (IHC 3+) rate was 8.8% (72/816) and MET overexpression rate was higher in HER2 positive patients (9.7%, 7/72). A high concordance rate (94.6%) between MET overexpression and gene amplification was demonstrated. Therefore, MET overexpression could serve as a prognostic biomarker and a potential therapeutic target for gastric cancer.

Overexpression of Myo1e in mouse podocytes enhances cellular endocytosis, migration, and adhesion.

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Jin, Xia; Wang, Wenjing; Mao, Jianhua; Shen, Huijun; Fu, Haidong; Wang, Xia; Gu, Weizhong; Liu, Aimin; Yu, Huimin; Shu, Qiang; Du, Lizhong

2014-02-01

Podocytes are a terminally differentiated and highly specialized cell type in the glomerulus that forms a crucial component of the glomerular filtration barrier. Recently, Myo1e was identified in the podocytes of glomeruli. Myo1e podocyte-specific knockout mice exhibit proteinuria, podocyte foot process effacement, glomerular basement membrane disorganization, signs of chronic renal injury, and kidney inflammation. After overexpression of Myo1e in a conditionally immortalized mouse podocyte cell line (MPC5), podocyte migration was evaluated via transwell assay, endocytosis was evaluated using FITC-transferrin, and adhesion was evaluated using a detachment assay after puromycin aminonucleoside treatment. Myo1e overexpression significantly increased the adherence of podocytes. ANOVA analysis indicated significant differences for cell adhesion between the overexpression and control groups (overexpression vs. control, t = 11.3199, P = 0.005; overexpression vs. negative control, t = 12.0570, P = 0.0006). Overexpression of Myo1e inhibited puromycin aminonucleoside-induced podocyte detachment, and the number of cells remaining on the bottom of the culture plate increased. Cell migration was enhanced in Myo1e-overexpressing podocytes in the transwell migration assay. Internalization of FITC-transferrin also increased in Myo1e-overexpressing podocytes relative to control cells. Overexpression of Myo1e can enhance podocyte migration ability, endocytosis, and attachment to the glomerular basement membrane. Restoration of Myo1e expression in podocytes may therefore strengthen their functional integrity against environmental and mechanical injury. © 2013 Wiley Periodicals, Inc.

Targeted delivery of antigen to intestinal dendritic cells induces oral tolerance and prevents autoimmune diabetes in NOD mice.

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Chen, Yulin; Wu, Jie; Wang, Jiajia; Zhang, Wenjing; Xu, Bohui; Xu, Xiaojun; Zong, Li

2018-03-15

The intestinal immune system is an ideal target to induce immune tolerance physiologically. However, the efficiency of oral protein antigen delivery is limited by degradation of the antigen in the gastrointestinal tract and poor uptake by antigen-presenting cells. Gut dendritic cells (DCs) are professional antigen-presenting cells that are prone to inducing antigen-specific immune tolerance. In this study, we delivered the antigen heat shock protein 65-6×P277 (H6P) directly to the gut DCs of NOD mice through oral vaccination with H6P-loaded targeting nanoparticles (NPs), and investigated the ability of this antigen to induce immune tolerance to prevent autoimmune diabetes in NOD mice. A targeting NP delivery system was developed to encapsulate H6P, and the ability of this system to protect and facilitate H6P delivery to gut DCs was assessed. NOD mice were immunised with H6P-loaded targeting NPs orally once a week for 7 weeks and the onset of diabetes was assessed by monitoring blood glucose levels. H6P-loaded targeting NPs protected the encapsulated H6P from degradation in the gastrointestinal tract environment and significantly increased the uptake of H6P by DCs in the gut Peyer's patches (4.1 times higher uptake compared with the control H6P solution group). Oral vaccination with H6P-loaded targeting NPs induced antigen-specific T cell tolerance and prevented diabetes in 100% of NOD mice. Immune deviation (T helper [Th]1 to Th2) and CD4 + CD25 + FOXP3 + regulatory T cells were found to participate in the induction of immune tolerance. In this study, we successfully induced antigen-specific T cell tolerance and prevented the onset of diabetes in NOD mice. To our knowledge, this is the first attempt at delivering antigen to gut DCs using targeting NPs to induce T cell tolerance.

Apolipoprotein CIII overexpression exacerbates diet-induced obesity due to adipose tissue higher exogenous lipid uptake and retention and lower lipolysis rates.

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Raposo, Helena F; Paiva, Adriene A; Kato, Larissa S; de Oliveira, Helena C F

2015-01-01

Hypertriglyceridemia is a common type of dyslipidemia found in obesity. However, it is not established whether primary hyperlipidemia can predispose to obesity. Evidences have suggested that proteins primarily related to plasma lipoprotein transport, such as apolipoprotein (apo) CIII and E, may significantly affect the process of body fat accumulation. We have previously observed an increased adiposity in response to a high fat diet (HFD) in mice overexpressing apoCIII. Here, we examined the potential mechanisms involved in this exacerbated response of apoCIII mice to the HFD. We measured body energy balance, tissue capacity to store exogenous lipids, lipogenesis and lipolysis rates in non-transgenic and apoCIII overexpressing mice fed a HFD during two months. Food intake, fat excretion and whole body CO2 production were similar in both groups. However, the adipose tissue mass (45 %) and leptin plasma levels (2-fold) were significantly greater in apoCIII mice. Lipogenesis rates were similar, while exogenous lipid retention was increased in perigonadal (2-fold) and brown adipose tissues (40 %) of apoCIII mice. In addition, adipocyte basal lipolysis (55 %) and in vivo lipolysis index (30 %) were significantly decreased in apoCIII mice. A fat tolerance test evidenced delayed plasma triglyceride clearance and greater transient availability of non-esterified fatty acids (NEFA) during the post-prandial state in the apoCIII mice plasma. Thus, apoCIII overexpression resulted in increased NEFA availability to adipose uptake and decreased adipocyte lipolysis, favoring lipid enlargement of adipose depots. We propose that plasma apoCIII levels represent a new risk factor for diet-induced obesity.

Spred-2 deficiency exacerbates lipopolysaccharide-induced acute lung inflammation in mice.

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Yang Xu

Full Text Available BACKGROUND: Acute respiratory distress syndrome (ARDS is a severe and life-threatening acute lung injury (ALI that is caused by noxious stimuli and pathogens. ALI is characterized by marked acute inflammation with elevated alveolar cytokine levels. Mitogen-activated protein kinase (MAPK pathways are involved in cytokine production, but the mechanisms that regulate these pathways remain poorly characterized. Here, we focused on the role of Sprouty-related EVH1-domain-containing protein (Spred-2, a negative regulator of the Ras-Raf-extracellular signal-regulated kinase (ERK-MAPK pathway, in lipopolysaccharide (LPS-induced acute lung inflammation. METHODS: Wild-type (WT mice and Spred-2(-/- mice were exposed to intratracheal LPS (50 µg in 50 µL PBS to induce pulmonary inflammation. After LPS-injection, the lungs were harvested to assess leukocyte infiltration, cytokine and chemokine production, ERK-MAPK activation and immunopathology. For ex vivo experiments, alveolar macrophages were harvested from untreated WT and Spred-2(-/- mice and stimulated with LPS. In in vitro experiments, specific knock down of Spred-2 by siRNA or overexpression of Spred-2 by transfection with a plasmid encoding the Spred-2 sense sequence was introduced into murine RAW264.7 macrophage cells or MLE-12 lung epithelial cells. RESULTS: LPS-induced acute lung inflammation was significantly exacerbated in Spred-2(-/- mice compared with WT mice, as indicated by the numbers of infiltrating leukocytes, levels of alveolar TNF-α, CXCL2 and CCL2 in a later phase, and lung pathology. U0126, a selective MEK/ERK inhibitor, reduced the augmented LPS-induced inflammation in Spred-2(-/- mice. Specific knock down of Spred-2 augmented LPS-induced cytokine and chemokine responses in RAW264.7 cells and MLE-12 cells, whereas Spred-2 overexpression decreased this response in RAW264.7 cells. CONCLUSIONS: The ERK-MAPK pathway is involved in LPS-induced acute lung inflammation. Spred-2 controls

Triggered Firing and Atrial Fibrillation in Transgenic Mice With Selective Atrial Fibrosis Induced by Overexpression of TGF-β1

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Choi, Eue-Keun; Chang, Po-Cheng; Lee, Young-Soo; Lin, Shien-Fong; Zhu, Wuqiang; Maruyama, Mitsunori; Fishbein, Michael C.; Chen, Zhenhui; der Lohe, Michael Rubart-von; Field, Loren J.; Chen, Peng-Sheng

2013-01-01

Background Calcium transient triggered firing (CTTF) is induced by large intracellular calcium (Cai) transient and short action potential duration (APD). We hypothesized that CTTF underlies the mechanisms of early afterdepolarization (EAD) and spontaneous recurrent atrial fibrillation (AF) in transgenic (Tx) mice with overexpression of transforming growth factor β1 (TGF-β1). Methods and Results MHC-TGFcys33ser Tx mice develop atrial fibrosis because of elevated levels of TGF-β1. We studied membrane potential and Cai transients of isolated superfused atria from Tx and wild-type (Wt) littermates. Short APD and persistently elevated Cai transients promoted spontaneous repetitive EADs, triggered activity and spontaneous AF after cessation of burst pacing in Tx but not Wt atria (39% vs. 0%, P=0.008). We were able to map optically 4 episodes of spontaneous AF re-initiation. All first and second beats of spontaneous AF originated from the right atrium (4/4, 100%), which is more severely fibrotic than the left atrium. Ryanodine and thapsigargin inhibited spontaneous re-initiation of AF in all 7 Tx atria tested. Western blotting showed no significant changes of calsequestrin or sarco/endoplasmic reticulum Ca2+-ATPase 2a. Conclusions Spontaneous AF may occur in the Tx atrium because of CTTF, characterized by APD shortening, prolonged Cai transient, EAD and triggered activity. Inhibition of Ca2+ release from the sarcoplasmic reticulum suppressed spontaneous AF. Our results indicate that CTTF is an important arrhythmogenic mechanism in TGF-β1 Tx atria. PMID:22447020

Targeting GPR110 in HER2-Overexpressing Breast Cancers

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2015-10-01

34assay"using"the"transwell" inserts"with" (A)"or"without" (B)"matrigel" for"SKBR3" cells "transfected"with"nonAtarge1ng"( NT1 )"orŗ"independent"GPR110"siRNAs...HER2 drug resistant cells and in tumorigenic population using a broad panel of cell line models. We have successfully generated inducible lentiviral...plasmids with GPR110 cDNA and cell lines that inducibly overexpress GPR110. Generation of cell lines with lentiviral plasmids containing GPR110

Overexpression of HER-2 via immunohistochemistry in canine urinary bladder transitional cell carcinoma - A marker of malignancy and possible therapeutic target.

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Millanta, F; Impellizeri, J; McSherry, L; Rocchigiani, G; Aurisicchio, L; Lubas, G

2018-06-01

Transitional cell carcinoma (TCC) is the most commonly diagnosed neoplasm in the urinary bladder. Distant metastases to the regional lymph nodes, lungs, abdominal organs or bones are noted in up to 50% of dogs at time of death. Surgical excision is often not practical as TCC typically involve the trigone of the bladder and/or occurs multifocally throughout the bladder with field cancerization. Therapeutic approaches are very challenging and the requirement to evaluate alternative therapeutic protocols that may prolong survival times in dogs bearing these tumours is compelling. We assessed the immunohistochemical expression of HER-2 in 23 cases of canine TCCs of the urinary bladder and compare it with non-neoplastic urothelium in order to evaluate a rationale for targeted therapies and gene-based vaccines. HER-2 positivity was recorded in 13/23 (56%) neoplastic lesions. The receptor was significantly overexpressed in neoplastic than in non-neoplastic samples (P = .015). According to our preliminary results, it would be of interest to further evaluate the role of HER-2 in canine TCCs as a marker of malignancy and a therapeutic target for cancer vaccine and antibodies. Moreover, the significantly different overexpression of HER-2 in TCCs than in non-neoplastic urothelium further supports to investigate its role in the progression toward malignancy of non-neoplastic lesions. © 2017 John Wiley & Sons Ltd.

A strong anti-inflammatory signature revealed by liver transcription profiling of Tmprss6-/- mice.

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Michela Riba

Full Text Available Control of systemic iron homeostasis is interconnected with the inflammatory response through the key iron regulator, the antimicrobial peptide hepcidin. We have previously shown that mice with iron deficiency anemia (IDA-low hepcidin show a pro-inflammatory response that is blunted in iron deficient-high hepcidin Tmprss6 KO mice. The transcriptional response associated with chronic hepcidin overexpression due to genetic inactivation of Tmprss6 is unknown. By using whole genome transcription profiling of the liver and analysis of spleen immune-related genes we identified several functional pathways differentially expressed in Tmprss6 KO mice, compared to IDA animals and thus irrespective of the iron status. In the effort of defining genes potentially targets of Tmprss6 we analyzed liver gene expression changes according to the genotype and independently of treatment. Tmprss6 inactivation causes down-regulation of liver pathways connected to immune and inflammatory response as well as spleen genes related to macrophage activation and inflammatory cytokines production. The anti-inflammatory status of Tmprss6 KO animals was confirmed by the down-regulation of pathways related to immunity, stress response and intracellular signaling in both liver and spleen after LPS treatment. Opposite to Tmprss6 KO mice, Hfe(-/- mice are characterized by iron overload with inappropriately low hepcidin levels. Liver expression profiling of Hfe(-/- deficient versus iron loaded mice show the opposite expression of some of the genes modulated by the loss of Tmprss6. Altogether our results confirm the anti-inflammatory status of Tmprss6 KO mice and identify new potential target pathways/genes of Tmprss6.

Overexpression of Dyrk1A is implicated in several cognitive, electrophysiological and neuromorphological alterations found in a mouse model of Down syndrome.

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Susana García-Cerro

Full Text Available Down syndrome (DS phenotypes result from the overexpression of several dosage-sensitive genes. The DYRK1A (dual-specificity tyrosine-(Y-phosphorylation regulated kinase 1A gene, which has been implicated in the behavioral and neuronal alterations that are characteristic of DS, plays a role in neuronal progenitor proliferation, neuronal differentiation and long-term potentiation (LTP mechanisms that contribute to the cognitive deficits found in DS. The purpose of this study was to evaluate the effect of Dyrk1A overexpression on the behavioral and cognitive alterations in the Ts65Dn (TS mouse model, which is the most commonly utilized mouse model of DS, as well as on several neuromorphological and electrophysiological properties proposed to underlie these deficits. In this study, we analyzed the phenotypic differences in the progeny obtained from crosses of TS females and heterozygous Dyrk1A (+/- male mice. Our results revealed that normalization of the Dyrk1A copy number in TS mice improved working and reference memory based on the Morris water maze and contextual conditioning based on the fear conditioning test and rescued hippocampal LTP. Concomitant with these functional improvements, normalization of the Dyrk1A expression level in TS mice restored the proliferation and differentiation of hippocampal cells in the adult dentate gyrus (DG and the density of GABAergic and glutamatergic synapse markers in the molecular layer of the hippocampus. However, normalization of the Dyrk1A gene dosage did not affect other structural (e.g., the density of mature hippocampal granule cells, the DG volume and the subgranular zone area or behavioral (i.e., hyperactivity/attention alterations found in the TS mouse. These results suggest that Dyrk1A overexpression is involved in some of the cognitive, electrophysiological and neuromorphological alterations, but not in the structural alterations found in DS, and suggest that pharmacological strategies targeting

Targeting annexin A7 by a small molecule suppressed the activity of phosphatidylcholine-specific phospholipase C in vascular endothelial cells and inhibited atherosclerosis in apolipoprotein E⁻/⁻mice.

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Li, H; Huang, S; Wang, S; Zhao, J; Su, L; Zhao, B; Zhang, Y; Zhang, S; Miao, J

2013-09-19

Phosphatidylcholine-specific phospholipase C (PC-PLC) is a key factor in apoptosis and autophagy of vascular endothelial cells (VECs), and involved in atherosclerosis in apolipoprotein E⁻/⁻ (apoE⁻/⁻) mice. But the endogenous regulators of PC-PLC are not known. We recently found a small chemical molecule (6-amino-2, 3-dihydro-3-hydroxymethyl-1, 4-benzoxazine, ABO) that could inhibit oxidized low-density lipoprotein (oxLDL)-induced apoptosis and promote autophagy in VECs, and further identified ABO as an inhibitor of annexin A7 (ANXA7) GTPase. Based on these findings, we hypothesize that ANXA7 is an endogenous regulator of PC-PLC, and targeting ANXA7 by ABO may inhibit atherosclerosis in apoE⁻/⁻ mice. In this study, we tested our hypothesis. The results showed that ABO suppressed oxLDL-induced increase of PC-PLC level and activity and promoted the co-localization of ANXA7 and PC-PLC in VECs. The experiments of ANXA7 knockdown and overexpression demonstrated that the action of ABO was ANXA7-dependent in cultured VECs. To investigate the relation of ANXA7 with PC-PLC in atherosclerosis, apoE⁻/⁻ mice fed with a western diet were treated with 50 or 100 mg/kg/day ABO. The results showed that ABO decreased PC-PLC levels in the mouse aortic endothelium and PC-PLC activity in serum, and enhanced the protein levels of ANXA7 in the mouse aortic endothelium. Furthermore, both dosages of ABO significantly enhanced autophagy and reduced apoptosis in the mouse aortic endothelium. As a result, ABO significantly reduced atherosclerotic plaque area and effectively preserved a stable plaques phenotype, including reduced lipid deposition and pro-inflammatory macrophages, increased anti-inflammatory macrophages, collagen content and smooth muscle cells, and less cell death in the plaques. In conclusion, ANXA7 was an endogenous regulator of PC-PLC, and targeting ANXA7 by ABO inhibited atherosclerosis in apoE⁻/⁻ mice.

TNF-Overexpression in Borna Disease Virus-Infected Mouse Brains Triggers Inflammatory Reaction and Epileptic Seizures

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Kramer, Katharina; Schaudien, Dirk; Eisel, Ulrich L. M.; Herzog, Sibylle; Richt, Juergen A.; Baumgaertner, Wolfgang; Herden, Christiane

2012-01-01

Proinflammatory state of the brain increases the risk for seizure development. Neonatal Borna disease virus (BDV)-infection of mice with neuronal overexpression of tumor necrosis factor-alpha (TNF) was used to investigate the complex relationship between enhanced cytokine levels, neurotropic virus

E2F1 activation is responsible for pituitary adenomas induced by HMGA2 gene overexpression

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Fusco Alfredo

2006-08-01

Full Text Available Abstract The High Mobility Group protein HMGA2 is a nuclear architectural factor that plays a critical role in a wide range of biological processes including regulation of gene expression, embryogenesis and neoplastic transformation. Several studies are trying to identify the mechanisms by which HMGA2 protein is involved in each of these activities, and only recently some new significant insights are emerging from the study of transgenic and knock-out mice. Overexpression of HMGA2 gene leads to the onset of prolactin and GH-hormone induced pituitary adenomas in mice, suggesting a critical role of this protein in pituitary tumorigenesis. This was also confirmed in the human pathology by the finding that HMGA2 amplification and/or overexpression is present in human prolactinomas. This review focuses on recent data that explain the mechanism by which HMGA2 induces the development of pituitary adenomas in mice. This mechanism entails the activation of the E2F1 protein by the HMGA2-mediated displacement of HDAC1 from pRB protein.

Transgenic overexpression of NanogP8 in the mouse prostate is insufficient to initiate tumorigenesis but weakly promotes tumor development in the Hi-Myc mouse model.

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Liu, Bigang; Gong, Shuai; Li, Qiuhui; Chen, Xin; Moore, John; Suraneni, Mahipal V; Badeaux, Mark D; Jeter, Collene R; Shen, Jianjun; Mehmood, Rashid; Fan, Qingxia; Tang, Dean G

2017-08-08

This project was undertaken to address a critical cancer biology question: Is overexpression of the pluripotency molecule Nanog sufficient to initiate tumor development in a somatic tissue? Nanog1 is critical for the self-renewal and pluripotency of ES cells, and its retrotransposed homolog, NanogP8 is preferentially expressed in somatic cancer cells. Our work has shown that shRNA-mediated knockdown of NanogP8 in prostate, breast, and colon cancer cells inhibits tumor regeneration whereas inducible overexpression of NanogP8 promotes cancer stem cell phenotypes and properties. To address the key unanswered question whether tissue-specific overexpression of NanogP8 is sufficient to promote tumor development in vivo , we generated a NanogP8 transgenic mouse model, in which the ARR 2 PB promoter was used to drive NanogP8 cDNA. Surprisingly, the ARR 2 PB-NanogP8 transgenic mice were viable, developed normally, and did not form spontaneous tumors in >2 years. Also, both wild type and ARR 2 PB-NanogP8 transgenic mice responded similarly to castration and regeneration and castrated ARR 2 PB-NanogP8 transgenic mice also did not develop tumors. By crossing the ARR 2 PB-NanogP8 transgenic mice with ARR 2 PB-Myc (i.e., Hi-Myc) mice, we found that the double transgenic (i.e., ARR 2 PB-NanogP8; Hi-Myc) mice showed similar tumor incidence and histology to the Hi-Myc mice. Interestingly, however, we observed white dots in the ventral lobes of the double transgenic prostates, which were characterized as overgrown ductules/buds featured by crowded atypical Nanog-expressing luminal cells. Taken together, our present work demonstrates that transgenic overexpression of NanogP8 in the mouse prostate is insufficient to initiate tumorigenesis but weakly promotes tumor development in the Hi-Myc mouse model.

GNB3 overexpression causes obesity and metabolic syndrome.

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Alev Cagla Ozdemir

Full Text Available The G-protein beta subunit 3 (GNB3 gene has been implicated in obesity risk; however, the molecular mechanism of GNB3-related disease is unknown. GNB3 duplication is responsible for a syndromic form of childhood obesity, and an activating DNA sequence variant (C825T in GNB3 is also associated with obesity. To test the hypothesis that GNB3 overexpression causes obesity, we created bacterial artificial chromosome (BAC transgenic mice that carry an extra copy of the human GNB3 risk allele. Here we show that GNB3-T/+ mice have increased adiposity, but not greater food intake or a defect in satiety. GNB3-T/+ mice have elevated fasting plasma glucose, insulin, and C-peptide, as well as glucose intolerance, indicating type 2 diabetes. Fasting plasma leptin, triglycerides, cholesterol and phospholipids are elevated, suggesting metabolic syndrome. Based on a battery of behavioral tests, GNB3-T/+ mice did not exhibit anxiety- or depressive-like phenotypes. GNB3-T/+ and wild-type animals have similar activity levels and heat production; however, GNB3-T/+ mice exhibit dysregulation of acute thermogenesis. Finally, Ucp1 expression is significantly lower in white adipose tissue (WAT in GNB3-T/+ mice, suggestive of WAT remodeling that could lead to impaired cellular thermogenesis. Taken together, our study provides the first functional link between GNB3 and obesity, and presents insight into novel pathways that could be applied to combat obesity and type 2 diabetes.

GNB3 overexpression causes obesity and metabolic syndrome.

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Ozdemir, Alev Cagla; Wynn, Grace M; Vester, Aimee; Weitzmann, M Neale; Neigh, Gretchen N; Srinivasan, Shanthi; Rudd, M Katharine

2017-01-01

The G-protein beta subunit 3 (GNB3) gene has been implicated in obesity risk; however, the molecular mechanism of GNB3-related disease is unknown. GNB3 duplication is responsible for a syndromic form of childhood obesity, and an activating DNA sequence variant (C825T) in GNB3 is also associated with obesity. To test the hypothesis that GNB3 overexpression causes obesity, we created bacterial artificial chromosome (BAC) transgenic mice that carry an extra copy of the human GNB3 risk allele. Here we show that GNB3-T/+ mice have increased adiposity, but not greater food intake or a defect in satiety. GNB3-T/+ mice have elevated fasting plasma glucose, insulin, and C-peptide, as well as glucose intolerance, indicating type 2 diabetes. Fasting plasma leptin, triglycerides, cholesterol and phospholipids are elevated, suggesting metabolic syndrome. Based on a battery of behavioral tests, GNB3-T/+ mice did not exhibit anxiety- or depressive-like phenotypes. GNB3-T/+ and wild-type animals have similar activity levels and heat production; however, GNB3-T/+ mice exhibit dysregulation of acute thermogenesis. Finally, Ucp1 expression is significantly lower in white adipose tissue (WAT) in GNB3-T/+ mice, suggestive of WAT remodeling that could lead to impaired cellular thermogenesis. Taken together, our study provides the first functional link between GNB3 and obesity, and presents insight into novel pathways that could be applied to combat obesity and type 2 diabetes.

Critical role of c-Jun overexpression in liver metastasis of human breast cancer xenograft model

International Nuclear Information System (INIS)

Zhang, Yan; Hu, Meiru; Shen, Beifen; Guo, Ning; Pu, Xiaoyun; Shi, Ming; Chen, Liyong; Song, Yuhua; Qian, Lu; Yuan, Guogang; Zhang, Hao; Yu, Ming

2007-01-01

c-Jun/AP-1 has been linked to invasive properties of aggressive breast cancer. Recently, it has been reported that overexpression of c-Jun in breast cancer cell line MCF-7 resulted in increased AP-1 activity, motility and invasiveness of the cells in vitro and tumor formation in nude mice. However, the role of c-Jun in metastasis of human breast cancer in vivo is currently unknown. To further investigate the direct involvement of c-Jun in tumorigenesis and metastasis, in the present study, the effects of c-Jun overexpression were studied in both in vitro and in nude mice. Ectopic overexpression of c-Jun promoted the growth of MCF-7 cells and resulted in a significant increase in the percentage of cells in S phase and increased motility and invasiveness. Introduction of c-Jun gene alone into weakly invasive MCF-7 cells resulted in the transfected cells capable of metastasizing to the nude mouse liver following tail vein injection. The present study confirms that overexpression of c-Jun contributes to a more invasive phenotype in MCF-7 cells. It indicates an interesting relationship between c-Jun expression and increased property of adhesion, migration and in vivo liver metastasis of MCF-7/c-Jun cells. The results provide further evidence that c-Jun is involved in the metastasis of breast cancer. The finding also opens an opportunity for development of anti-c-Jun strategies in breast cancer therapy

Aurora-A overexpression and aneuploidy predict poor outcome in serous ovarian carcinoma.

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Lassus, Heini; Staff, Synnöve; Leminen, Arto; Isola, Jorma; Butzow, Ralf

2011-01-01

Aurora-A is a potential oncogene and therapeutic target in ovarian carcinoma. It is involved in mitotic events and overexpression leads to centrosome amplification and chromosomal instability. The objective of this study was to evaluate the clinical significance of Aurora-A and DNA ploidy in serous ovarian carcinoma. Serous ovarian carcinomas were analysed for Aurora-A protein by immunohistochemistry (n=592), Aurora-A copy number by CISH (n=169), Aurora-A mRNA by real-time PCR (n=158) and DNA ploidy by flowcytometry (n=440). Overexpression of Aurora-A was found in 27% of the tumors, cytoplasmic overexpression in 11% and nuclear in 17%. The cytoplasmic and nuclear overexpression were nearly mutually exclusive. Both cytoplasmic and nuclear overexpression were associated with shorter survival, high grade, high proliferation index and aberrant p53. Interestingly, only cytoplasmic expression was associated with aneuploidy and expression of phosphorylated Aurora-A. DNA ploidy was associated with poor patient outcome as well as aggressive clinicopathological parameters. In multivariate analysis, Aurora-A overexpression appeared as an independent prognostic factor for disease-free survival, together with grade, stage and ploidy. Aurora-A protein expression is strongly linked with poor patient outcome and aggressive disease characteristics, which makes Aurora-A a promising biomarker and a potential therapeutic target in ovarian carcinoma. Cytoplasmic and nuclear Aurora-A protein may have different functions. DNA aneuploidy is a strong predictor of poor prognosis in serous ovarian carcinoma. Copyright © 2010 Elsevier Inc. All rights reserved.

Corticotropin-releasing factor overexpression in mice abrogates sex differences in body weight, visceral fat, and food intake response to a fast and alters levels of feeding regulatory hormones.

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Wang, Lixin; Goebel-Stengel, Miriam; Yuan, Pu-Qing; Stengel, Andreas; Taché, Yvette

2017-01-01

Corticotropin-releasing factor overexpressing (CRF-OE) male mice showed an inhibited feeding response to a fast, and lower plasma acyl ghrelin and Fos expression in the arcuate nucleus compared to wild-type (WT) mice. We investigated whether hormones and hypothalamic feeding signals are impaired in CRF-OE mice and the influence of sex. Male and female CRF-OE mice and WT littermates (4-6 months old) fed ad libitum or overnight fasted were assessed for body, adrenal glands and perigonadal fat weights, food intake, plasma hormones, blood glucose, and mRNA hypothalamic signals. Under fed conditions, compared to WT, CRF-OE mice have increased adrenal glands and perigonadal fat weight, plasma corticosterone, leptin and insulin, and hypothalamic leptin receptor and decreased plasma acyl ghrelin. Compared to male, female WT mice have lower body and perigonadal fat and plasma leptin but higher adrenal glands weights. CRF-OE mice lost these sex differences except for the adrenals. Male CRF-OE and WT mice did not differ in hypothalamic expression of neuropeptide Y (NPY) and proopiomelanocortin (POMC), while female CRF-OE compared to female WT and male CRF-OE had higher NPY mRNA levels. After fasting, female WT mice lost more body weight and ate more food than male WT, while CRF-OE mice had reduced body weight loss and inhibited food intake without sex difference. In male WT mice, fasting reduced plasma insulin and leptin and increased acyl ghrelin and corticosterone while female WT showed only a rise in corticosterone. In CRF-OE mice, fasting reduced insulin while leptin, acyl ghrelin and corticosterone were unchanged with no sex difference. Fasting blood glucose was higher in CRF-OE with female > male. In WT mice, fasting increased hypothalamic NPY expression in both sexes and decreased POMC only in males, while in CRF-OE mice, NPY did not change, and POMC decreased in males and increased in females. These data indicate that CRF-OE mice have abnormal basal and fasting

Claudins Overexpression in Ovarian Cancer: Potential Targets for Clostridium Perfringens Enterotoxin (CPE Based Diagnosis and Therapy

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Diana P. English

2013-05-01

Full Text Available Claudins are a family of tight junction proteins regulating paracellular permeability and cell polarity with different patterns of expression in benign and malignant human tissues. There are approximately 27 members of the claudin family identified to date with varying cell and tissue-specific expression. Claudins-3, -4 and -7 represent the most highly differentially expressed claudins in ovarian cancer. While their exact role in ovarian tumors is still being elucidated, these proteins are thought to be critical for ovarian cancer cell invasion/dissemination and resistance to chemotherapy. Claudin-3 and claudin-4 are the natural receptors for the Clostridium perfringens enterotoxin (CPE, a potent cytolytic toxin. These surface proteins may therefore represent attractive targets for the detection and treatment of chemotherapy-resistant ovarian cancer and other aggressive solid tumors overexpressing claudin-3 and -4 using CPE-based theranostic agents.

Dual-Ligand Modified Polymer-Lipid Hybrid Nanoparticles for Docetaxel Targeting Delivery to Her2/neu Overexpressed Human Breast Cancer Cells.

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Yang, Zhe; Tang, Wenxin; Luo, Xingen; Zhang, Xiaofang; Zhang, Chao; Li, Hao; Gao, Di; Luo, Huiyan; Jiang, Qing; Liu, Jie

2015-08-01

In this study, a dual-ligand polymer-lipid hybrid nanoparticle drug delivery vehicle comprised of an anti-HER2/neu peptide (AHNP) mimic with a modified HIV-1 Tat (mTAT) was established for the targeted treatment of Her2/neu-overexpressing cells. The resultant dual-ligand hybrid nanoparticles (NPs) consisted of a poly(lactide-co-glycolide) core, a near 90% surface coverage of the lipid monolayer, and a 5.7 nm hydrated polyethylene glycol shell. Ligand density optimization study revealed that cellular uptake efficiency of the hybrid NPs could be manipulated by controlling the surface-ligand densities. Furthermore, the cell uptake kinetics and mechanism studies showed that the dual-ligand modifications of hybrid NPs altered the cellular uptake pathway from caveolae-mediated endocytosis (CvME) to the multiple endocytic pathways, which would significantly enhance the NP internalization. Upon the systemic investigation of the cellular uptake behavior of dual-ligand hybrid NPs, docetaxel (DTX), a hydrophobic anticancer drug, was successfully encapsulated into dual-ligand hybrid NPs with high drug loading for Her2/neu-overexpressing SK-BR-3 breast cancer cell treatment. The DTX-loaded dual-ligand hybrid NPs showed a decreased burst release and a more gradual sustained drug release property. Because of the synergistic effect of dual-ligand modification, DTX-loaded dual-ligand hybrid NPs exerted substantially better therapeutic potency against SK-BR-3 cancer cells than other NP formulations and free DTX drugs. These results demonstrate that the dual-ligand hybrid NPs could be a promising vehicle for targeted drug delivery to treat breast cancer.

Intraductal delivery of adenoviruses targets pancreatic tumors in transgenic Ela-myc mice and orthotopic xenografts.

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José, Anabel; Sobrevals, Luciano; Miguel Camacho-Sánchez, Juan; Huch, Meritxell; Andreu, Núria; Ayuso, Eduard; Navarro, Pilar; Alemany, Ramon; Fillat, Cristina

2013-01-01

Gene-based anticancer therapies delivered by adenoviruses are limited by the poor viral distribution into the tumor. In the current work we have explored the feasibility of targeting pancreatic tumors through a loco-regional route. We have taken advantage of the ductal network in the pancreas to retrogradelly inject adenoviruses through the common bile duct in two different mouse models of pancreatic carcinogenesis: The transgenic Ela-myc mice that develop mixed neoplasms displaying both acinar-like and duct-like neoplastic cells affecting the whole pancreas; and mice bearing PANC-1 and BxPC-3 orthotopic xenografts that constitute a model of localized human neoplastic tumors. We studied tumor targeting and the anticancer effects of newly thymidine kinase-engineered adenoviruses both in vitro and in vivo, and conducted comparative studies between intraductal or intravenous administration. Our data indicate that the intraductal delivery of adenovirus efficiently targets pancreatic tumors in the two mouse models. The in vivo application of AduPARTKT plus ganciclovir (GCV) treatment induced tumor regression in Ela-myc mice. Moreover, the intraductal injection of ICOVIR15-TKT oncolytic adenoviruses significantly improved mean survival of mice bearing PANC-1 and BxPC-3 pancreatic xenografts from 30 to 52 days and from 20 to 68 days respectively (p less than 0.0001) when combined with GCV. Of notice, both AduPARTKT and ICOVIR15-TKT antitumoral responses were stronger by ductal viral application than intravenously, in line with the 38-fold increase in pancreas transduction observed upon ductal administration. In summary our data show that cytotoxic adenoviruses retrogradelly injected to the pancreas can be a feasible approach to treat localized pancreatic tumors.

Overexpression of the endothelial protein C receptor is detrimental during pneumonia-derived gram-negative sepsis (Melioidosis.

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Liesbeth M Kager

Full Text Available The endothelial protein C receptor (EPCR enhances anticoagulation by accelerating activation of protein C to activated protein C (APC and mediates anti-inflammatory effects by facilitating APC-mediated signaling via protease activated receptor-1. We studied the role of EPCR in the host response during pneumonia-derived sepsis instigated by Burkholderia (B. pseudomallei, the causative agent of melioidosis, a common form of community-acquired Gram-negative (pneumosepsis in South-East Asia.Soluble EPCR was measured in plasma of patients with septic culture-proven melioidosis and healthy controls. Experimental melioidosis was induced by intranasal inoculation of B. pseudomallei in wild-type (WT mice and mice with either EPCR-overexpression (Tie2-EPCR or EPCR-deficiency (EPCR(-/-. Mice were sacrificed after 24, 48 or 72 hours. Organs and plasma were harvested to measure colony forming units, cellular influxes, cytokine levels and coagulation parameters. Plasma EPCR-levels were higher in melioidosis patients than in healthy controls and associated with an increased mortality. Tie2-EPCR mice demonstrated enhanced bacterial growth and dissemination to distant organs during experimental melioidosis, accompanied by increased lung damage, neutrophil influx and cytokine production, and attenuated coagulation activation. EPCR(-/- mice had an unremarkable response to B. pseudomallei infection as compared to WT mice, except for a difference in coagulation activation in plasma.Increased EPCR-levels correlate with accelerated mortality in patients with melioidosis. In mice, transgenic overexpression of EPCR aggravates outcome during Gram-negative pneumonia-derived sepsis caused by B. pseudomallei, while endogenous EPCR does not impact on the host response. These results add to a better understanding of the regulation of coagulation during severe (pneumosepsis.

Dual oxidase maturation factor 1 (DUOXA1) overexpression increases reactive oxygen species production and inhibits murine muscle satellite cell differentiation.

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Sandiford, Shelley D E; Kennedy, Karen A M; Xie, Xiaojun; Pickering, J Geoffrey; Li, Shawn S C

2014-01-11

Dual oxidase maturation factor 1 (DUOXA1) has been associated with the maturation of the reactive oxygen species (ROS) producing enzyme, dual oxidase 1 (DUOX1) in the adult thyroid. However, ROS have also been implicated in the development of several tissues. We found that activated muscle satellite cells and primary myoblasts isolated from mice express robust levels of DUOXA1 and that its levels are altered as cells differentiate. To determine whether DUOXA1 levels affect muscle differentiation, we used an adenoviral construct (pCMV5-DUOXA1-GFP) to drive constitutive overexpression of this protein in primary myoblasts. High levels of DUOXA1 throughout myogenesis resulted in enhanced H2O2 production, fusion defects, reduced expression of early (myogenin) and late (myosin heavy chain) markers of differentiation, and elevated levels of apoptosis compared to control cells infected with an empty adenoviral vector (pCMV5-GFP). DUOXA1 knockdown (using a DUOXA1 shRNA construct) resulted in enhanced differentiation compared to cells subjected to a control shRNA, and subjecting DUOXA1 overexpressing cells to siRNAs targeting DUOX1 or apoptosis signal-regulating kinase 1 (ASK1) rescued the phenotype. This study represents the first to demonstrate the importance of DUOXA1 in skeletal muscle myoblasts and that DUOXA1 overexpression in muscle stem cells induces apoptosis and inhibits differentiation through DUOX1 and ASK1.

A new anti-tumor strategy based on in vivo tumstatin overexpression after plasmid electrotransfer in muscle

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Thevenard, Jessica, E-mail: jessica.thevenard@univ-reims.fr [FRE CNRS/URCA 3481, University of Reims Champagne-Ardenne, 51 rue Cognacq Jay, F-51095 Reims (France); Ramont, Laurent, E-mail: lramont@chu-reims.fr [FRE CNRS/URCA 3481, University of Reims Champagne-Ardenne, 51 rue Cognacq Jay, F-51095 Reims (France); CHU de Reims, Avenue du Général Koenig, F-51092 Reims (France); Mir, Lluis M., E-mail: luis.mir@igr.fr [CNRS, UMR 8203, Institut Gustave Roussy, 114, Rue Edouard Vaillant, F-94805 Villejuif Cedex (France); Université Paris-Sud, UMR 8203, Institut Gustave Roussy, 114, Rue Edouard Vaillant, F-94405 Orsay Cedex (France); Dupont-Deshorgue, Aurélie, E-mail: aurelie.dupont@univ-reims.fr [FRE CNRS/URCA 3481, University of Reims Champagne-Ardenne, 51 rue Cognacq Jay, F-51095 Reims (France); Maquart, François-Xavier, E-mail: fmaquart@chu-reims.fr [FRE CNRS/URCA 3481, University of Reims Champagne-Ardenne, 51 rue Cognacq Jay, F-51095 Reims (France); CHU de Reims, Avenue du Général Koenig, F-51092 Reims (France); Monboisse, Jean-Claude, E-mail: jc.monboisse@univ-reims.fr [FRE CNRS/URCA 3481, University of Reims Champagne-Ardenne, 51 rue Cognacq Jay, F-51095 Reims (France); CHU de Reims, Avenue du Général Koenig, F-51092 Reims (France); Brassart-Pasco, Sylvie, E-mail: sylvie.brassart-pasco@univ-reims.fr [FRE CNRS/URCA 3481, University of Reims Champagne-Ardenne, 51 rue Cognacq Jay, F-51095 Reims (France)

2013-03-22

Highlights: ► A new therapeutic strategy based on tumstatin in vivo overexpression is proposed. ► pVAX1©–tumstatin electrotransfer in muscle mediates protein expression in muscle. ► A substantial expression of tumstatin is detected in the serum of electrotransfected mice. ► Tumstatin overexpression decreases tumor growth and increases mouse survival. -- Abstract: The NC1 domains from the different α(IV) collagen chains were found to exert anti-tumorigenic and/or anti-angiogenic activities. A limitation to the therapeutic use of these matrikines is the large amount of purified recombinant proteins, in the milligram range in mice that should be administered daily throughout the experimental procedures. In the current study, we developed a new therapeutic approach based on tumstatin (NC1α3(IV)) overexpression in vivo in a mouse melanoma model. Gene electrotransfer of naked plasmid DNA (pDNA) is particularly attractive because of its simplicity, its lack of immune responsiveness and its safety. The pDNA electrotransfer in muscle mediates a substantial gene expression that lasts several months. A pVAX1© vector containing the tumstatin cDNA was injected into the legs of C57BL/6 mice and submitted to electrotranfer. Sera were collected at different times and tumstatin was quantified by ELISA. Tumstatin secretion reached a plateau at day 21 with an expression level of 12 μg/mL. For testing the effects of tumstatin expression on tumor growth in vivo, B16F1 melanoma cells were subcutaneously injected in mice 7 days after empty pVAX1© (Mock) or pVAX1©–tumstatin electrotransfer. Tumstatin expression triggered a large decrease in tumor growth and an increase in mouse survival. This new therapeutic approach seems promising to inhibit tumor progression in vivo.

A new anti-tumor strategy based on in vivo tumstatin overexpression after plasmid electrotransfer in muscle

International Nuclear Information System (INIS)

Thevenard, Jessica; Ramont, Laurent; Mir, Lluis M.; Dupont-Deshorgue, Aurélie; Maquart, François-Xavier; Monboisse, Jean-Claude; Brassart-Pasco, Sylvie

2013-01-01

Highlights: ► A new therapeutic strategy based on tumstatin in vivo overexpression is proposed. ► pVAX1©–tumstatin electrotransfer in muscle mediates protein expression in muscle. ► A substantial expression of tumstatin is detected in the serum of electrotransfected mice. ► Tumstatin overexpression decreases tumor growth and increases mouse survival. -- Abstract: The NC1 domains from the different α(IV) collagen chains were found to exert anti-tumorigenic and/or anti-angiogenic activities. A limitation to the therapeutic use of these matrikines is the large amount of purified recombinant proteins, in the milligram range in mice that should be administered daily throughout the experimental procedures. In the current study, we developed a new therapeutic approach based on tumstatin (NC1α3(IV)) overexpression in vivo in a mouse melanoma model. Gene electrotransfer of naked plasmid DNA (pDNA) is particularly attractive because of its simplicity, its lack of immune responsiveness and its safety. The pDNA electrotransfer in muscle mediates a substantial gene expression that lasts several months. A pVAX1© vector containing the tumstatin cDNA was injected into the legs of C57BL/6 mice and submitted to electrotranfer. Sera were collected at different times and tumstatin was quantified by ELISA. Tumstatin secretion reached a plateau at day 21 with an expression level of 12 μg/mL. For testing the effects of tumstatin expression on tumor growth in vivo, B16F1 melanoma cells were subcutaneously injected in mice 7 days after empty pVAX1© (Mock) or pVAX1©–tumstatin electrotransfer. Tumstatin expression triggered a large decrease in tumor growth and an increase in mouse survival. This new therapeutic approach seems promising to inhibit tumor progression in vivo

Myofiber-specific TEAD1 overexpression drives satellite cell hyperplasia and counters pathological effects of dystrophin deficiency

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Southard, Sheryl; Kim, Ju-Ryoung; Low, SiewHui; Tsika, Richard W; Lepper, Christoph

2016-01-01

When unperturbed, somatic stem cells are poised to affect immediate tissue restoration upon trauma. Yet, little is known regarding the mechanistic basis controlling initial and homeostatic ‘scaling’ of stem cell pool sizes relative to their target tissues for effective regeneration. Here, we show that TEAD1-expressing skeletal muscle of transgenic mice features a dramatic hyperplasia of muscle stem cells (i.e. satellite cells, SCs) but surprisingly without affecting muscle tissue size. Super-numeral SCs attain a ‘normal’ quiescent state, accelerate regeneration, and maintain regenerative capacity over several injury-induced regeneration bouts. In dystrophic muscle, the TEAD1 transgene also ameliorated the pathology. We further demonstrate that hyperplastic SCs accumulate non-cell-autonomously via signal(s) from the TEAD1-expressing myofiber, suggesting that myofiber-specific TEAD1 overexpression activates a physiological signaling pathway(s) that determines initial and homeostatic SC pool size. We propose that TEAD1 and its downstream effectors are medically relevant targets for enhancing muscle regeneration and ameliorating muscle pathology. DOI: http://dx.doi.org/10.7554/eLife.15461.001 PMID:27725085

CD147 overexpression promotes tumorigenicity in Chinese hamster ovary cells.

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Yong, Yu-Le; Liao, Cheng-Gong; Wei, Ding; Chen, Zhi-Nan; Bian, Huijie

2016-04-01

CD147 overexpresses in many epithelium-originated tumors and plays an important role in tumor migration and invasion. Most studies aim at the role of CD147 in tumor progression using tumor cell models. However, the influence of abnormal overexpression of CD147 on neoplastic transformation of normal cells is unknown. Here, the role of CD147 in malignant phenotype transformation in CHO cells was investigated. Three CHO cell lines that stably overexpressed CD147 (CHO-CD147), EGFP-CD147 (CHO-EGFP-CD147), and EGFP (CHO-EGFP) were generated by transfection of plasmids containing human CD147, EGFP-human CD147, and EGFP genes into CHO cells. Cell migration and invasion were detected by wound healing and transwell matrix penetration assay. Trypan blue exclusion, MTT, cell cycle analysis, and BrdU cell proliferation assay were used to detect cell viability and cell proliferation. Annexin V-FITC analysis was performed to detect apoptosis. We found that CD147 overexpression promoted the migration and invasion of CHO cells. CD147 accelerated the G1 to S phase transition and enhanced the CHO cell proliferation. Overexpression of CD147 inhibited both early- and late-stages of apoptosis of CHO-CD147 cells, which is caused by serum deprivation. CHO-EGFP-CD147 cells showed an increased anchorage-independent growth compared with CHO-EGFP cells as detected by soft-agar colony formation assay. The tumors formed by CHO-CD147 cells in nude mice were larger and coupled with higher expression of proliferating cell nuclear antigen and Ki-67 than that of CHO cells. In conclusion, human CD147 overexpression induces malignant phenotype in CHO cells. © 2015 International Federation for Cell Biology.

Restoration of the cellular secretory milieu overrides androgen dependence of in vivo generated castration resistant prostate cancer cells overexpressing the androgen receptor.

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Patki, Mugdha; Huang, Yanfang; Ratnam, Manohar

2016-07-22

It is believed that growth of castration resistant prostate cancer (CRPC) cells is enabled by sensitization to minimal residual post-castrate androgen due to overexpression of the androgen receptor (AR). Evidence is derived from androgen-induced colony formation in the absence of cell-secreted factors or from studies involving forced AR overexpression in hormone-dependent cells. On the other hand, standard cell line models established from CRPC patient tumors (e.g., LNCaP and VCaP) are hormone-dependent and require selection pressure in castrated mice to re-emerge as CRPC cells and the resulting tumors then tend to be insensitive to the androgen antagonist enzalutamide. Therefore, we examined established CRPC model cells produced by castration of mice bearing hormone-dependent cell line xenografts including CRPC cells overexpressing full-length AR (C4-2) or co-expressing wtAR and splice-variant AR-V7 that is incapable of ligand binding (22Rv1). In standard colony formation assays, C4-2 cells were shown to be androgen-dependent and sensitive to enzalutamide whereas 22Rv1 cells were incapable of colony formation under identical conditions. However, both C4-2 and 22Rv1 cells formed colonies in conditioned media derived from the same cells or from HEK293 fibroblasts that were proven to lack androgenic activity. This effect was (i) not enhanced by androgen, (ii) insensitive to enzalutamide, (iii) dependent on AR (in C4-2) and on AR-V7 and wtAR (in 22Rv1) and (iv) sensitive to inhibitors of several signaling pathways, similar to androgen-stimulation. Therefore, during progression to CRPC in vivo, coordinate cellular changes accompanying overexpression of AR may enable cooperation between hormone-independent activity of AR and actions of cellular secretory factors to completely override androgen-dependence and sensitivity to drugs targeting hormonal factors. Copyright © 2016 Elsevier Inc. All rights reserved.

Conditional Expression of Wnt4 during Chondrogenesis Leads to Dwarfism in Mice

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Lee, Hu-Hui; Behringer, Richard R.

2007-01-01

Wnts are expressed in the forming long bones, suggesting roles in skeletogenesis. To examine the action of Wnts in skeleton formation, we developed a genetic system to conditionally express Wnt4 in chondrogenic tissues of the mouse. A mouse Wnt4 cDNA was introduced into the ubiquitously expressed Rosa26 (R26) locus by gene targeting in embryonic stem (ES) cells. The expression of Wnt4 from the R26 locus was blocked by a neomycin selection cassette flanked by loxP sites (floxneo) that was positioned between the Rosa26 promoter and the Wnt4 cDNA, creating the allele designated R26floxneoWnt4. Wnt4 expression was activated during chondrogenesis using Col2a1-Cre transgenic mice that express Cre recombinase in differentiating chondrocytes. R26floxneoWnt4; Col2a1-Cre double heterozygous mice exhibited a growth deficiency, beginning approximately 7 to 10 days after birth, that resulted in dwarfism. In addition, they also had craniofacial abnormalities, and delayed ossification of the lumbar vertebrae and pelvic bones. Histological analysis revealed a disruption in the organization of the growth plates and a delay in the onset of the primary and secondary ossification centers. Molecular studies showed that Wnt4 overexpression caused decreased proliferation and altered maturation of chondrocytes. In addition, R26floxneoWnt4; Col2a1-Cre mice had decreased expression of vascular endothelial growth factor (VEGF). These studies demonstrate that Wnt4 overexpression leads to dwarfism in mice. The data indicate that Wnt4 levels must be regulated in chondrocytes for normal growth plate development and skeletogenesis. Decreased VEGF expression suggests that defects in vascularization may contribute to the dwarf phenotype. PMID:17505543

Conditional expression of Wnt4 during chondrogenesis leads to dwarfism in mice.

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Hu-Hui Lee

Full Text Available Wnts are expressed in the forming long bones, suggesting roles in skeletogenesis. To examine the action of Wnts in skeleton formation, we developed a genetic system to conditionally express Wnt4 in chondrogenic tissues of the mouse. A mouse Wnt4 cDNA was introduced into the ubiquitously expressed Rosa26 (R26 locus by gene targeting in embryonic stem (ES cells. The expression of Wnt4 from the R26 locus was blocked by a neomycin selection cassette flanked by loxP sites (floxneo that was positioned between the Rosa26 promoter and the Wnt4 cDNA, creating the allele designated R26(floxneoWnt4. Wnt4 expression was activated during chondrogenesis using Col2a1-Cre transgenic mice that express Cre recombinase in differentiating chondrocytes. R26(floxneoWnt4; Col2a1-Cre double heterozygous mice exhibited a growth deficiency, beginning approximately 7 to 10 days after birth, that resulted in dwarfism. In addition, they also had craniofacial abnormalities, and delayed ossification of the lumbar vertebrae and pelvic bones. Histological analysis revealed a disruption in the organization of the growth plates and a delay in the onset of the primary and secondary ossification centers. Molecular studies showed that Wnt4 overexpression caused decreased proliferation and altered maturation of chondrocytes. In addition, R26(floxneoWnt4; Col2a1-Cre mice had decreased expression of vascular endothelial growth factor (VEGF. These studies demonstrate that Wnt4 overexpression leads to dwarfism in mice. The data indicate that Wnt4 levels must be regulated in chondrocytes for normal growth plate development and skeletogenesis. Decreased VEGF expression suggests that defects in vascularization may contribute to the dwarf phenotype.

Expression of GAT1 in male reproductive system and its effects on reproduction in mice.

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Zhang, JinFu; Gui, YaPing; Yuan, Tao; Bian, CuiDong; Guo, LiHe

2009-12-01

The present study was carried out to identify GABA (gamma-aminobutyric acid) transport protein I (GAT1) in male reproductive organs and to study the effect of GAT1 overexpression on the male reproductive system in GAT1 transgenic mice (TG). Expression and location of GAT1 in testes, epididymis, and sperm of wild-type (WT) mice were identified by immunohistochemistry and western-blot. Histological changes of testes, epididymis, and sperm of transgenic mice overexpressing GAT1 were detected by immunofluorenscent staining and haematoxylin and eosin (HE) staining. GAT1 expression was detected in the testes, epididymis, and sperm of non-transgenic mice. Vacuolization and deformity of spermatogenic cells were observed in the transgenic mice, but the epididymis was unremarkable. Immunofluorenscent staining showed that the number of diastrophic and decapitated sperm increased significantly in transgenic mice to 46.9% from 7.3% in nontransgenic mice. These results suggest that abnormal expression of GAT1 could result in spermiogenesis function injury, sperm paramorphia and dysgenesis.

Genes and Alcohol Consumption: Studies with Mutant Mice

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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

Overexpression screens identify conserved dosage chromosome instability genes in yeast and human cancer

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Duffy, Supipi; Fam, Hok Khim; Wang, Yi Kan; Styles, Erin B.; Kim, Jung-Hyun; Ang, J. Sidney; Singh, Tejomayee; Larionov, Vladimir; Shah, Sohrab P.; Andrews, Brenda; Boerkoel, Cornelius F.; Hieter, Philip

2016-01-01

Somatic copy number amplification and gene overexpression are common features of many cancers. To determine the role of gene overexpression on chromosome instability (CIN), we performed genome-wide screens in the budding yeast for yeast genes that cause CIN when overexpressed, a phenotype we refer to as dosage CIN (dCIN), and identified 245 dCIN genes. This catalog of genes reveals human orthologs known to be recurrently overexpressed and/or amplified in tumors. We show that two genes, TDP1, a tyrosyl-DNA-phosphdiesterase, and TAF12, an RNA polymerase II TATA-box binding factor, cause CIN when overexpressed in human cells. Rhabdomyosarcoma lines with elevated human Tdp1 levels also exhibit CIN that can be partially rescued by siRNA-mediated knockdown of TDP1. Overexpression of dCIN genes represents a genetic vulnerability that could be leveraged for selective killing of cancer cells through targeting of an unlinked synthetic dosage lethal (SDL) partner. Using SDL screens in yeast, we identified a set of genes that when deleted specifically kill cells with high levels of Tdp1. One gene was the histone deacetylase RPD3, for which there are known inhibitors. Both HT1080 cells overexpressing hTDP1 and rhabdomyosarcoma cells with elevated levels of hTdp1 were more sensitive to histone deacetylase inhibitors valproic acid (VPA) and trichostatin A (TSA), recapitulating the SDL interaction in human cells and suggesting VPA and TSA as potential therapeutic agents for tumors with elevated levels of hTdp1. The catalog of dCIN genes presented here provides a candidate list to identify genes that cause CIN when overexpressed in cancer, which can then be leveraged through SDL to selectively target tumors. PMID:27551064

MicroRNA-214 Suppresses Gluconeogenesis by Targeting Activating Transcriptional Factor 4*

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Li, Kai; Zhang, Jin; Yu, Junjie; Liu, Bin; Guo, Yajie; Deng, Jiali; Chen, Shanghai; Wang, Chunxia; Guo, Feifan

2015-01-01

Although the gluconeogenesis pathway is already a target for the treatment of type 2 diabetes, the potential role of microRNAs (miRNAs) in gluconeogenesis remains unclear. Here, we investigated the physiological functions of miR-214 in gluconeogenesis. The expression of miR-214 was suppressed by glucagon via protein kinase A signaling in primary hepatocytes, and miR-214 was down-regulated in the livers of fasted, high fat diet-induced diabetic and leptin receptor-mutated (db/db) mice. The overexpression of miR-214 in primary hepatocytes suppressed glucose production, and silencing miR-214 reversed this effect. Gluconeogenesis was suppressed in the livers of mice injected with an adenovirus expressing miR-214 (Ad-miR-214). Additionally, Ad-miR-214 alleviated high fat diet-induced elevation of gluconeogenesis and hyperglycemia. Furthermore, we found that activating transcription factor 4 (ATF4), a reported target of miR-214, can reverse the suppressive effect of miR-214 on gluconeogenesis in primary hepatocytes, and this suppressive effect was blocked in liver-specific ATF4 knock-out mice. ATF4 regulated gluconeogenesis via affecting forkhead box protein O1 (FOXO1) transcriptional activity. Finally, liver-specific miR-214 transgenic mice exhibited suppressed gluconeogenesis and reduced expression of ATF4, phosphoenolpyruvate carboxykinase, and glucose-6-phosphatase in liver. Taken together, our results suggest that the miR-214-ATF4 axis is a novel pathway for the regulation of hepatic gluconeogenesis. PMID:25657009

Development of a new anti-cancer agent for targeted radionuclide therapy: β- radiolabeled RAFT-RGD

International Nuclear Information System (INIS)

Petitprin, A.

2013-01-01

β-emitters radiolabeled RAFT-RGD as new agents for internal targeted radiotherapy. The αvβ3 integrin is known to play an important role in tumor-induced angiogenesis, tumor proliferation, survival and metastasis. Because of its overexpression on neo-endothelial cells such as those present in growing tumors, as well as on tumor cells of various origins, αvβ3 integrin is an attractive molecular target for diagnosis and therapy of the rapidly growing and metastatic tumors. A tetrameric RGD-based peptide, regioselectively addressable functionalized template-(cyclo-[RGDfK])4 (RAFT-RGD), specifically targets integrin αvβ3 in vitro and in vivo. RAFT-RGD has been used for tumor imaging and drug targeting. This study is the first to evaluate the therapeutic potential of the β-emitters radiolabeled tetrameric RGD peptide RAFT-RGD in a Nude mouse model of αvβ3 -expressing tumors. An injection of 37 MBq of 90 Y-RAFT-RGD or 177 Lu-RAFT-RGD in mice with αvβ3 -positive tumors caused a significant growth delay as compared with mice treated with 37 MBq of 90 Y-RAFT-RAD or 177 Lu-RAFT-RAD or untreated mice. In comparison, an injection of 30 MBq of 90 Y-RAFT-RGD had no efficacy for the treatment of αvβ3 -negative tumors. 90 Y-RAFT-RGD and 177 Lu-RAFT-RGD are potent αvβ3 -expressing tumor targeting agents for internal targeted radiotherapy. (author)

Fibroblast growth factor 21 has no direct role in regulating fertility in female mice

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Garima Singhal

2016-08-01

Full Text Available Objective: Reproduction is an energetically expensive process. Insufficient calorie reserves, signaled to the brain through peripheral signals such as leptin, suppress fertility. Recently, fibroblast growth factor 21 (FGF21 was implicated as a signal from the liver to the hypothalamus that directly inhibits the hypothalamic–gonadotropin axis during fasting and starvation. However, FGF21 itself increases metabolic rate and can induce weight loss, which suggests that the effects of FGF21 on fertility may not be direct and may reflect changes in energy balance. Methods: To address this important question, we evaluated fertility in several mouse models with elevated FGF21 levels including ketogenic diet fed mice, fasted mice, mice treated with exogenous FGF21 and transgenic mice over-expressing FGF21. Results: We find that ketogenic diet fed mice remain fertile despite significant elevation in serum FGF21 levels. Absence of FGF21 does not alter transient infertility induced by fasting. Centrally infused FGF21 does not suppress fertility despite its efficacy in inducing browning of inguinal white adipose tissue. Furthermore, a high fat diet (HFD can restore fertility of female FGF21-overexpressing mice, a model of growth restriction, even in the presence of supraphysiological serum FGF21 levels. Conclusions: We conclude that FGF21 is not a direct physiological regulator of fertility in mice. The infertility observed in FGF21 overexpressing mice is likely driven by the increased energy expenditure and consequent excess calorie requirements resulting from high FGF21 levels. Keywords: FGF21, Fertility, Leptin, Hypothalamic action

Sphingosine kinase 1 is a relevant molecular target in gastric cancer

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Fuereder, Thorsten; Hoeflmayer, Doris; Jaeger-Lansky, Agnes

2011-01-01

Sphingosine kinase 1 (Sphk1), a lipid kinase implicated in cell transformation and tumor growth, is overexpressed in gastric cancer and is linked with a poor prognosis. The biological relevance of Sphk1 expression in gastric cancer is unclear. Here, we studied the functional significance of Sphk1...... as a novel molecular target for gastric cancer by using an antisense oligonucleotide approach in vitro and in vivo. Gastric cancer cell lines (MKN28 and N87) were treated with Sphk1 with locked nucleic acid-antisense oligonucleotides (LNA-ASO). Sphk1 target regulation, cell growth, and apoptosis were...... assessed for single-agent Sphk1 LNA-ASO and for combinations with doxorubicin. Athymic nude mice xenografted with gastric cancer cells were treated with Sphk1 LNA and assessed for tumor growth and Sphk1 target regulation, in vivo. In vitro, nanomolar concentrations of Sphk1 LNA-ASO induced an approximately...

Low-dose radiation potentiates the therapeutic efficacy of folate receptor-targeted hapten therapy.

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Sega, Emanuela I; Lu, Yingjuan; Ringor, Michael; Leamon, Christopher P; Low, Philip S

2008-06-01

Human cancers frequently overexpress a high-affinity cell-surface receptor for the vitamin folic acid. Highly immunogenic haptens can be targeted to folate receptor-expressing cell surfaces by administration of folate-hapten conjugates, rendering the decorated tumor cell surfaces more recognizable by the immune system. Treatment of antihapten-immunized mice with folate-hapten constructs results in elimination of moderately sized tumors by the immune system. However, when subcutaneous tumors exceed 300 mm(3) before initiation of therapy, antitumor activity is significantly decreased. In an effort to enhance the efficacy of folate-targeted hapten immunotherapy (FTHI) against large tumors, we explored the combination of targeted hapten immunotherapy with low-dose radiotherapy. Mice bearing 300-mm(3) subcutaneous tumors were treated concurrently with FTHI (500 nmol/kg of folate conjugated to fluorescein isothiocyanate, 20,000 U/dose of interleukin 2, and 25,000 U/dose of interferon alpha) and low-dose radiotherapy (3 Gy/dose focused directly on the desired tumor mass). The efficacy of therapy was evaluated by measuring tumor volume. Tumor growth analyses show that radiotherapy synergizes with FTHI in antihapten-immunized mice, thereby allowing for cures of animals bearing tumors greater than 300 mm(3). More importantly, nonirradiated distal tumor masses in animals containing locally irradiated tumors also showed improved response to hapten immunotherapy, suggesting that not all tumor lesions must be identified and irradiated to benefit from the combination therapy. These results suggest that simultaneous treatment with FTHI and radiation therapy can enhance systemic antitumor activity in tumor-bearing mice.

Low-Dose Radiation Potentiates the Therapeutic Efficacy of Folate Receptor-Targeted Hapten Therapy

International Nuclear Information System (INIS)

Sega, Emanuela I.; Lu Yingjuan; Ringor, Michael; Leamon, Christopher P.; Low, Philip S.

2008-01-01

Purpose: Human cancers frequently overexpress a high-affinity cell-surface receptor for the vitamin folic acid. Highly immunogenic haptens can be targeted to folate receptor-expressing cell surfaces by administration of folate-hapten conjugates, rendering the decorated tumor cell surfaces more recognizable by the immune system. Treatment of antihapten-immunized mice with folate-hapten constructs results in elimination of moderately sized tumors by the immune system. However, when subcutaneous tumors exceed 300 mm 3 before initiation of therapy, antitumor activity is significantly decreased. In an effort to enhance the efficacy of folate-targeted hapten immunotherapy (FTHI) against large tumors, we explored the combination of targeted hapten immunotherapy with low-dose radiotherapy. Methods and Materials: Mice bearing 300-mm 3 subcutaneous tumors were treated concurrently with FTHI (500 nmol/kg of folate conjugated to fluorescein isothiocyanate, 20,000 U/dose of interleukin 2, and 25,000 U/dose of interferon α) and low-dose radiotherapy (3 Gy/dose focused directly on the desired tumor mass). The efficacy of therapy was evaluated by measuring tumor volume. Results: Tumor growth analyses show that radiotherapy synergizes with FTHI in antihapten-immunized mice, thereby allowing for cures of animals bearing tumors greater than 300 mm 3 . More importantly, nonirradiated distal tumor masses in animals containing locally irradiated tumors also showed improved response to hapten immunotherapy, suggesting that not all tumor lesions must be identified and irradiated to benefit from the combination therapy. Conclusions: These results suggest that simultaneous treatment with FTHI and radiation therapy can enhance systemic antitumor activity in tumor-bearing mice

Targeted Therapy for Melanoma

International Nuclear Information System (INIS)

Quinn, Thomas; Moore, Herbert

2016-01-01

The research project, entitled ''Targeted Therapy for Melanoma,'' was focused on investigating the use of kidney protection measures to lower the non-specific kidney uptake of the radiolabeled Pb-DOTA-ReCCMSH peptide. Previous published work demonstrated that the kidney exhibited the highest non-target tissue uptake of the "2"1"2"P"b"/"2"0"3Pb radiolabeled melanoma targeting peptide DOTA-ReCCMSH. The radiolabeled alpha-melanocyte stimulating hormone (α-MSH) peptide analog DOTA-Re(Arg"1"1)CCMSH, which binds the melanocortin-1 receptor over-expressed on melanoma tumor cells, has shown promise as a PRRT agent in pre-clinical studies. High tumor uptake of "2"1"2Pb labeled DOTA-Re(Arg"1"1)CCMSH resulted in tumor reduction or eradication in melanoma therapy studies. Of particular note was the 20-50% cure rate observed when melanoma mice were treated with alpha particle emitter "2"1"2Pb. However, as with most PRRT agents, high radiation doses to the kidneys where observed. To optimize tumor treatment efficacy and reduce nephrotoxicity, the tumor to kidney uptake ratio must be improved. Strategies to reduce kidney retention of the radiolabeled peptide, while not effecting tumor uptake and retention, can be broken into several categories including modification of the targeting peptide sequence and reducing proximal tubule reabsorption.

Targeted Therapy for Melanoma

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Quinn, Thomas [Alphamed, Jackson, TN (United States); Moore, Herbert [Alphamed, Jackson, TN (United States)

2016-12-05

The research project, entitled ”Targeted Therapy for Melanoma,” was focused on investigating the use of kidney protection measures to lower the non-specific kidney uptake of the radiolabeled Pb-DOTA-ReCCMSH peptide. Previous published work demonstrated that the kidney exhibited the highest non-target tissue uptake of the ^212Pb/203Pb radiolabeled melanoma targeting peptide DOTA-ReCCMSH. The radiolabeled alpha-melanocyte stimulating hormone (α-MSH) peptide analog DOTA-Re(Arg¹¹)CCMSH, which binds the melanocortin-1 receptor over-expressed on melanoma tumor cells, has shown promise as a PRRT agent in pre-clinical studies. High tumor uptake of ²¹²Pb labeled DOTA-Re(Arg¹¹)CCMSH resulted in tumor reduction or eradication in melanoma therapy studies. Of particular note was the 20-50% cure rate observed when melanoma mice were treated with alpha particle emitter ²¹²Pb. However, as with most PRRT agents, high radiation doses to the kidneys where observed. To optimize tumor treatment efficacy and reduce nephrotoxicity, the tumor to kidney uptake ratio must be improved. Strategies to reduce kidney retention of the radiolabeled peptide, while not effecting tumor uptake and retention, can be broken into several categories including modification of the targeting peptide sequence and reducing proximal tubule reabsorption.

Overexpression of mouse TTF-2 gene causes cleft palate

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Meng, Tian; Shi, Jia-Yu; Wu, Min; Wang, Yan; Li, Ling; Liu, Yan; Zheng, Qian; Huang, Lei; Shi, Bing

2012-01-01

In humans, mutations of the gene encoding for thyroid transcription factor-2 (TTF-2 or FOXE1) result in Bamforth syndrome. Bamforth syndrome is characterized by agenesis, cleft palate, spiky hair and choanal atresia. TTF-2 null mice (TTF-2−/−) also exhibit cleft palate, suggesting its involvement in the palatogenesis. However, the molecular pathology and genetic regulation by TTF2 remain largely unknown. In the present study, the recombinant expression vector pBROAD3-TTF-2 containing the promoter of the mouse ROSA26 gene was created to form the structural gene of mouse TTF-2 and was microinjected into the male pronuclei of fertilized ova. Sequence analysis confirmed that the TTF-2 transgenic mouse model was established successfully. The transgenic mice displayed a phenotype of cleft palate. In addition, we found that TTF-2 was highly expressed in the medial edge epithelium (MEE) from the embryonic day 12.5 (E12.5) to E14.5 in TTF-2 transgenic mice. These observations suggest that overexpression of TTF-2 during palatogenesis may contribute to formation of cleft palate. PMID:22304410

Overexpression and deletion of phospholipid transfer protein reduce HDL mass and cholesterol efflux capacity but not macrophage reverse cholesterol transport[S

Science.gov (United States)

Kuwano, Takashi; Bi, Xin; Cipollari, Eleonora; Yasuda, Tomoyuki; Lagor, William R.; Szapary, Hannah J.; Tohyama, Junichiro; Millar, John S.; Billheimer, Jeffrey T.; Lyssenko, Nicholas N.; Rader, Daniel J.

2017-01-01

Phospholipid transfer protein (PLTP) may affect macrophage reverse cholesterol transport (mRCT) through its role in the metabolism of HDL. Ex vivo cholesterol efflux capacity and in vivo mRCT were assessed in PLTP deletion and PLTP overexpression mice. PLTP deletion mice had reduced HDL mass and cholesterol efflux capacity, but unchanged in vivo mRCT. To directly compare the effects of PLTP overexpression and deletion on mRCT, human PLTP was overexpressed in the liver of wild-type animals using an adeno-associated viral (AAV) vector, and control and PLTP deletion animals were injected with AAV-null. PLTP overexpression and deletion reduced plasma HDL mass and cholesterol efflux capacity. Both substantially decreased ABCA1-independent cholesterol efflux, whereas ABCA1-dependent cholesterol efflux remained the same or increased, even though preβ HDL levels were lower. Neither PLTP overexpression nor deletion affected excretion of macrophage-derived radiocholesterol in the in vivo mRCT assay. The ex vivo and in vivo assays were modified to gauge the rate of cholesterol efflux from macrophages to plasma. PLTP activity did not affect this metric. Thus, deviations in PLTP activity from the wild-type level reduce HDL mass and ex vivo cholesterol efflux capacity, but not the rate of macrophage cholesterol efflux to plasma or in vivo mRCT. PMID:28137768

β‑catenin nuclear translocation induced by HIF‑1α overexpression leads to the radioresistance of prostate cancer.

Science.gov (United States)

Luo, Yong; Li, Mingchuan; Zuo, Xuemei; Basourakos, Spyridon P; Zhang, Jiao; Zhao, Jiahui; Han, Yili; Lin, Yunhua; Wang, Yongxing; Jiang, Yongguang; Lan, Ling

2018-04-12

Hypoxia-inducible factor‑1α (HIF‑1α) is known to play crucial roles in tumor radioresistance; however, the molecular mechanisms responsible for the promotion of tumor radioresistance by HIF‑1α remain unclear. β‑catenin is known to be involved in the metastatic potential of prostate cancer (PCa). In this study, to investigate the role of HIF‑1α and β‑catenin in the radioresistance of PCa, two PCa cell lines, LNCaP and C4‑2B, were grouped as follows: Negative control (no treatment), HIF‑1α overexpression group (transfected with HIF‑1α overexpression plasmid) and β‑catenin silenced group (transfected with HIF‑1α plasmids and β‑catenin-shRNA). Cell proliferation, cell cycle, cell invasion and radiosensitivity were examined under normal or hypoxic conditions. In addition, radiosensitivity was examined in two mouse PCa models (the LNCaP orthotopic BALB/c-nu mice model and the C4‑2B subcutaneous SCID mice model). Our results revealed that in both the LNCaP and C4‑2B cells, transfection with HIF‑1α overexpression plasmid led to an enhanced β‑catenin nuclear translocation, while β‑catenin silencing inhibited β‑catenin nuclear translocation. The enhanced β‑catenin nuclear translocation induced by HIF‑1α overexpression resulted in an enhanced cell proliferation and cell invasion, an altered cell cycle distribution, decreased apoptosis, and improved non‑homologous end joining (NHEJ) repair under normal and irradiation conditions. Similar results were observed in the animal models. HIF‑1α overexpression enhanced β‑catenin nuclear translocation, which led to the activation of the β‑catenin/NHEJ signaling pathway and increased cell proliferation, cell invasion and DNA repair. These results thus suggest that HIF‑1α overexpression promotes the radioresistance of PCa cells.

Impaired TFEB-mediated Lysosome Biogenesis and Autophagy Promote Chronic Ethanol-induced Liver Injury and Steatosis in Mice.

Science.gov (United States)

Chao, Xiaojuan; Wang, Shaogui; Zhao, Katrina; Li, Yuan; Williams, Jessica A; Li, Tiangang; Chavan, Hemantkumar; Krishnamurthy, Partha; He, Xi C; Li, Linheng; Ballabio, Andrea; Ni, Hong-Min; Ding, Wen-Xing

2018-05-18

Defects in lysosome function and autophagy contribute to pathogenesis of alcoholic liver disease. We investigated the mechanisms by which alcohol consumption affects these processes, evaluating the functions transcription factor EB (TFEB), which regulates lysosomal biogenesis. We performed studies with GFP-LC3 mice, mice with liver-specific deletion of transcription factor EB (TFEB), mice with disruption of the transcription factor E3 gene (TFE3-knockout mice), mice with disruption of the Tefb and Tfe3 genes (TFEB, TFE3 double-knockout mice), and Tfeb flox/flox albumin cre-negative mice (controls). TFEB was overexpressed from adenoviral vectors or knocked down with small interfering RNAs in mouse livers. Mice were placed on diets of chronic ethanol feeding plus an acute binge to induce liver damage (ethanol diet); some mice were also given injections of torin1, an inhibitor of the kinase activity of the mechanistic target of rapamycin (mTOR). Liver tissues were collected and analyzed by immunohistochemistry, immunoblots, and quantitative real-time PCR to monitor lysosome biogenesis. We analyzed levels of TFEB in liver tissues from patients with alcoholic hepatitis and from healthy donors (controls) by immunohistochemistry. Liver tissues from mice on the ethanol diet had lower levels of total and nuclear TFEB, compared with control mice, and hepatocytes had reduced lysosome biogenesis and autophagy. Hepatocytes from mice on the ethanol diet had increased translocation of mTOR into lysosomes, resulting increased mTOR activation. Administration of torin1 increased liver levels of TFEB and reduced steatosis and liver injury induced by ethanol. Mice that overexpressed TFEB in liver developed less-severe ethanol-induced liver injury and had increased lysosomal biogenesis and mitochondrial bioenergetics compared to mice carrying a control vector. Mice with knockdown of TFEB, as well as TFEB, TFE3 double-knockout mice, developed more severe liver injury in response to the

Overexpression of Glucocorticoid Receptor β Enhances Myogenesis and Reduces Catabolic Gene Expression.

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Hinds, Terry D; Peck, Bailey; Shek, Evan; Stroup, Steven; Hinson, Jennifer; Arthur, Susan; Marino, Joseph S

2016-02-11

Unlike the glucocorticoid receptor α (GRα), GR β (GRβ) has a truncated ligand-binding domain that prevents glucocorticoid binding, implicating GRα as the mediator of glucocorticoid-induced skeletal muscle loss. Because GRβ causes glucocorticoid resistance, targeting GRβ may be beneficial in impairing muscle loss as a result of GRα activity. The purpose of this study was to determine how the overexpression of GRβ affects myotube formation and dexamethasone (Dex) responsiveness. We measured GR isoform expression in C₂C12 muscle cells in response to Dex and insulin, and through four days of myotube formation. Next, lentiviral-mediated overexpression of GRβ in C₂C12 was performed, and these cells were characterized for cell fusion and myotube formation, as well as sensitivity to Dex via the expression of ubiquitin ligases. GRβ overexpression increased mRNA levels of muscle regulatory factors and enhanced proliferation in myoblasts. GRβ overexpressing myotubes had an increased fusion index. Myotubes overexpressing GRβ had lower forkhead box O3 (Foxo3a) mRNA levels and a blunted muscle atrophy F-box/Atrogen-1 (MAFbx) and muscle ring finger 1 (MuRF1) response to Dex. We showed that GRβ may serve as a pharmacological target for skeletal muscle growth and protection from glucocorticoid-induced catabolic signaling. Increasing GRβ levels in skeletal muscle may cause a state of glucocorticoid resistance, stabilizing muscle mass during exposure to high doses of glucocorticoids.

Overexpression of Glucocorticoid Receptor β Enhances Myogenesis and Reduces Catabolic Gene Expression

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Terry D. Hinds

2016-02-01

Full Text Available Unlike the glucocorticoid receptor α (GRα, GR β (GRβ has a truncated ligand-binding domain that prevents glucocorticoid binding, implicating GRα as the mediator of glucocorticoid-induced skeletal muscle loss. Because GRβ causes glucocorticoid resistance, targeting GRβ may be beneficial in impairing muscle loss as a result of GRα activity. The purpose of this study was to determine how the overexpression of GRβ affects myotube formation and dexamethasone (Dex responsiveness. We measured GR isoform expression in C2C12 muscle cells in response to Dex and insulin, and through four days of myotube formation. Next, lentiviral-mediated overexpression of GRβ in C2C12 was performed, and these cells were characterized for cell fusion and myotube formation, as well as sensitivity to Dex via the expression of ubiquitin ligases. GRβ overexpression increased mRNA levels of muscle regulatory factors and enhanced proliferation in myoblasts. GRβ overexpressing myotubes had an increased fusion index. Myotubes overexpressing GRβ had lower forkhead box O3 (Foxo3a mRNA levels and a blunted muscle atrophy F-box/Atrogen-1 (MAFbx and muscle ring finger 1 (MuRF1 response to Dex. We showed that GRβ may serve as a pharmacological target for skeletal muscle growth and protection from glucocorticoid-induced catabolic signaling. Increasing GRβ levels in skeletal muscle may cause a state of glucocorticoid resistance, stabilizing muscle mass during exposure to high doses of glucocorticoids.

c-MET Overexpression in Colorectal Cancer: A Poor Prognostic Factor for Survival.

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Lee, Su Jin; Lee, Jeeyun; Park, Se Hoon; Park, Joon Oh; Lim, Ho Yeong; Kang, Won Ki; Park, Young Suk; Kim, Seung Tae

2018-03-02

Increased mesenchymal-epithelial transition factor gene (c-MET) expression in several human malignancies is related to increased tumor progression and is a new potential drug target for several types of cancers. In the present study, we investigated the incidence of c-MET overexpression and its prognostic significance in patients with colorectal cancer (CRC). We retrospectively reviewed the data from 255 stage IV CRC patients who had results from a c-MET immunohistochemical test at Samsung Medical Center. We explored the relationships between c-MET overexpression and clinicopathological features and survival. Primary tumor sites were 67 right-sided colon, 98 left-sided colon, and 90 rectum. Forty-two patients (16.7%) had poorly differentiated or mucinous carcinoma. Among the 255 patients, 39 (15.3%) exhibited c-MET overexpression. There was no significant difference in the prevalence of c-MET overexpression according to primary site, histologic differentiation, molecular markers, or metastatic sites. In a comparison of the tumor response to first-line chemotherapy according to the level of c-MET expression, we found no significant difference in either partial response or disease control rate. In the survival analysis, patients with c-MET overexpression had significantly shorter overall survival (39 vs. 27 months; P = .018) and progression-free survival (PFS) during bevacizumab treatment (10 vs. 7 months; P = .024). c-MET overexpression, which was detected in 39 CRC patients (15.3%) irrespective of primary sites or molecular markers, indicated a poor survival prognosis and predicted shorter PFS during bevacizumab treatment in patients with CRC. Further studies are warranted to elucidate the value of c-MET-targeted therapy in CRC patients. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

miR-206 inhibits cell proliferation, migration, and invasion by targeting BAG3 in human cervical cancer.

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Wang, Yingying; Tian, Yongjie

2018-01-02

miR-206 and bcl2-associated athanogene 3 (BAG3) have been suggested as important regulators in various cancer types. However, the biological role of miR-206 and BAG3 in cervical cancer (CC) remains unclear. Here, we investigated the expressions and mechanisms of miR-206 and BAG3 in cervical cancer using in vitro and in vivo assays. In the present study, miR-206 expression was expressed at a lower level in CC tissues and cells than adjacent normal tissues and NEEC cells. By contrast, BAG3 mRNA and protein were expressed at higher levels in CC tissues and cells. Furthermore, miR-206 overexpression repressed cell proliferation, migration and invasion in vitro, and the 3'-untranslated region (3'-UTR) of BAG3 was a direct target of miR-206. miR-206 overexpression also inhibited EGFR, Bcl-2 and MMP2/9 protein expression, but promoted Bax protein expression. Besides, BAG3 over-expression partially abrogated miR-206-inhibited cell proliferation and invasion, while BAG3 silencing enhanced miR206-mediated inhibition. In vivo assay revealed that miR-206 repressed tumor growth in nude mice xenograft model. In conclusion, miR-206 inhibits cell proliferation, migration, and invasion by targeting BAG3 in human cervical cancer. Thus, miR-206-BAG3 can be used as a useful target for cervical cancer.

miR-378 attenuates muscle regeneration by delaying satellite cell activation and differentiation in mice.

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Zeng, Ping; Han, Wanhong; Li, Changyin; Li, Hu; Zhu, Dahai; Zhang, Yong; Liu, Xiaohong

2016-09-01

Skeletal muscle mass and homeostasis during postnatal muscle development and regeneration largely depend on adult muscle stem cells (satellite cells). We recently showed that global overexpression of miR-378 significantly reduced skeletal muscle mass in mice. In the current study, we used miR-378 transgenic (Tg) mice to assess the in vivo functional effects of miR-378 on skeletal muscle growth and regeneration. Cross-sectional analysis of skeletal muscle tissues showed that the number and size of myofibers were significantly lower in miR-378 Tg mice than in wild-type mice. Attenuated cardiotoxin-induced muscle regeneration in miR-378 Tg mice was found to be associated with delayed satellite cell activation and differentiation. Mechanistically, miR-378 was found to directly target Igf1r in muscle cells both in vitro and in vivo These miR-378 Tg mice may provide a model for investigating the physiological and pathological roles of skeletal muscle in muscle-associated diseases in humans, particularly in sarcopenia. © The Author 2016. Published by Oxford University Press on behalf of the Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Endothelial Nitric Oxide Synthase Overexpression Restores the Efficiency of Bone Marrow Mononuclear Cell-Based Therapy

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Mees, Barend; Récalde, Alice; Loinard, Céline; Tempel, Dennie; Godinho, Marcia; Vilar, José; van Haperen, Rien; Lévy, Bernard; de Crom, Rini; Silvestre, Jean-Sébastien

2011-01-01

Bone marrow-derived mononuclear cells (BMMNCs) enhance postischemic neovascularization, and their therapeutic use is currently under clinical investigation. However, cardiovascular risk factors, including diabetes mellitus and hypercholesterolemia, lead to the abrogation of BMMNCs proangiogenic potential. NO has been shown to be critical for the proangiogenic function of BMMNCs, and increased endothelial NO synthase (eNOS) activity promotes vessel growth in ischemic conditions. We therefore hypothesized that eNOS overexpression could restore both the impaired neovascularization response and decreased proangiogenic function of BMMNCs in clinically relevant models of diabetes and hypercholesterolemia. Transgenic eNOS overexpression in diabetic, atherosclerotic, and wild-type mice induced a 1.5- to 2.3-fold increase in postischemic neovascularization compared with control. eNOS overexpression in diabetic or atherosclerotic BMMNCs restored their reduced proangiogenic potential in ischemic hind limb. This effect was associated with an increase in BMMNC ability to differentiate into cells with endothelial phenotype in vitro and in vivo and an increase in BMMNCs paracrine function, including vascular endothelial growth factor A release and NO-dependent vasodilation. Moreover, although wild-type BMMNCs treatment resulted in significant progression of atherosclerotic plaque in ischemic mice, eNOS transgenic atherosclerotic BMMNCs treatment even had antiatherogenic effects. Cell-based eNOS gene therapy has both proangiogenic and antiatherogenic effects and should be further investigated for the development of efficient therapeutic neovascularization designed to treat ischemic cardiovascular disease. PMID:21224043

Autism-like Deficits in Shank3-Deficient Mice Are Rescued by Targeting Actin Regulators

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Lara J. Duffney

2015-06-01

Full Text Available Haploinsufficiency of the Shank3 gene, which encodes a scaffolding protein at glutamatergic synapses, is a highly prevalent and penetrant risk factor for autism. Using combined behavioral, electrophysiological, biochemical, imaging, and molecular approaches, we find that Shank3-deficient mice exhibit autism-like social deficits and repetitive behaviors, as well as the significantly diminished NMDA receptor (NMDAR synaptic function and synaptic distribution in prefrontal cortex. Concomitantly, Shank3-deficient mice have a marked loss of cortical actin filaments, which is associated with the reduced Rac1/PAK activity and increased activity of cofilin, the major actin depolymerizing factor. The social deficits and NMDAR hypofunction are rescued by inhibiting cofilin or activating Rac1 in Shank3-deficient mice and are induced by inhibiting PAK or Rac1 in wild-type mice. These results indicate that the aberrant regulation of synaptic actin filaments and loss of synaptic NMDARs contribute to the manifestation of autism-like phenotypes. Thus, targeting actin regulators provides a strategy for autism treatment.

Ecto-5'-Nucleotidase Overexpression Reduces Tumor Growth in a Xenograph Medulloblastoma Model.

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Angélica R Cappellari

Full Text Available Ecto-5'-nucleotidase/CD73 (ecto-5'-NT participates in extracellular ATP catabolism by converting adenosine monophosphate (AMP into adenosine. This enzyme affects the progression and invasiveness of different tumors. Furthermore, the expression of ecto-5'-NT has also been suggested as a favorable prognostic marker, attributing to this enzyme contradictory functions in cancer. Medulloblastoma (MB is the most common brain tumor of the cerebellum and affects mainly children.The effects of ecto-5'-NT overexpression on human MB tumor growth were studied in an in vivo model. Balb/c immunodeficient (nude 6 to 14-week-old mice were used for dorsal subcutaneous xenograph tumor implant. Tumor development was evaluated by pathophysiological analysis. In addition, the expression patterns of adenosine receptors were verified.The human MB cell line D283, transfected with ecto-5'-NT (D283hCD73, revealed reduced tumor growth compared to the original cell line transfected with an empty vector. D283hCD73 generated tumors with a reduced proliferative index, lower vascularization, the presence of differentiated cells and increased active caspase-3 expression. Prominent A1 adenosine receptor expression rates were detected in MB cells overexpressing ecto-5'-NT.This work suggests that ecto-5'-NT promotes reduced tumor growth to reduce cell proliferation and vascularization, promote higher differentiation rates and initiate apoptosis, supposedly by accumulating adenosine, which then acts through A1 adenosine receptors. Therefore, ecto-5'-NT might be considered an important prognostic marker, being associated with good prognosis and used as a potential target for therapy.

Overexpression of the muscle-specific protein, melusin, protects from cardiac ischemia/reperfusion injury.

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Penna, Claudia; Brancaccio, Mara; Tullio, Francesca; Rubinetto, Cristina; Perrelli, Maria-Giulia; Angotti, Carmelina; Pagliaro, Pasquale; Tarone, Guido

2014-07-01

Melusin is a muscle-specific protein which interacts with β1 integrin cytoplasmic domain and acts as chaperone protein. Its overexpression induces improved resistance to cardiac overload delaying left ventricle dilation and reducing the occurrence of heart failure. Here, we investigated possible protective effect of melusin overexpression against acute ischemia/reperfusion (I/R) injury with or without Postconditioning cardioprotective maneuvers. Melusin transgenic (Mel-TG) mice hearts were subjected to 30-min global ischemia followed by 60-min reperfusion. Interestingly, infarct size was reduced in Mel-TG mice hearts compared to wild-type (WT) hearts (40.3 ± 3.5 % Mel-TG vs. 59.5 ± 3.8 % WT hearts; n = 11 animals/group; P level of AKT, ERK1/2 and GSK3β phosphorylation, and displayed increased phospho-kinases level after I/R compared to WT mice. Post-ischemic Mel-TG hearts displayed also increased levels of the anti-apoptotic factor phospho-BAD. Importantly, pharmacological inhibition of PI3K/AKT (Wortmannin) and ERK1/2 (U0126) pathways abrogated the melusin protective effect. Notably, HSP90, a chaperone known to protect heart from I/R injury, showed high levels of expression in the heart of Mel-TG mice suggesting a possible collaboration of this molecule with AKT/ERK/GSK3β pathways in the melusin-induced protection. Postconditioning, known to activate AKT/ERK/GSK3β pathways, significantly reduced IS and LDH release in WT hearts, but had no additive protective effects in Mel-TG hearts. These findings implicate melusin as an enhancer of AKT and ERK pathways and as a novel player in cardioprotection from I/R injury.

The development of a highly specific radiochemical compound based on labeled 99mtc recombinant molecules for targeted imaging of cells with the overexpression of Her-2 / neu

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Olga D. Bragina

2017-01-01

Full Text Available Currently, there is a urgent need to search for new diagnostic methods that allow us to reveal malignant tumors with the overexpression of Her-2/neu with high accuracy. In recent years radioisotope methods have been actively developing to identify specific tumor targets, with antibodies being the “targeting” module.The purpose of the study. Creation of a chemically stable radiochemical compound for the imaging of cells with the overexpression of Her-2/neu.Materials and methods. The study was conducted using two human adenocarcinoma cell lines with expression (BT-474 and without expression (MCF-7 Her-2/neu. The specificity of the binding of the test complex with Her-2/neu receptor was determined by direct radiometric and planar scintigraphy. To evaluate the differences in quantitative characteristics between the groups a non-parametric Mann – Whitney test was used.Results. The yield of the labeled complex was more than 91% and the radiochemical frequency was more than 94%. When performing a visual scintigraphic evaluation, a much higher accumulation rate of the studied radiopharmaceutical preparation (RFP was observed in the culture of cells with overexpression of the surface Her-2/neu receptor. Direct radiometric results also demonstrated a higher accumulation of RFPs in the human BT-474 mammary adenocarcinoma cell line with Her-2/neu overexpression in comparison with the control group.Conclusion. Preclinical studies demonstrated high stability of the test compound, as well as its accumulation in the group of cells with Her-2/neu overexpression

Stable Skin-specific Overexpression of Human CTLA4-Ig in Transgenic Mice through Seven Generations

Institute of Scientific and Technical Information of China (English)

Yong WANG; Yong NI; Hong WEI; Feng-Chao WANG; Liang-Peng GE; Xiang GAO

2006-01-01

Skin graft rejection is a typical cellular immune response, mainly mediated by T cells. Cytotoxic T lymphocyte associated antigen 4-immunoglobin (CTLA4-Ig) extends graft survival by blocking the T cell co-stimulation pathway and inhibiting T cell activation. To investigate the efficacy of CTLA4-Ig in prolonging skin graft survival, human CTLA4-Ig (hCTLA4-Ig) was engineered to overexpress in mouse skin by transgenesis using the K14 promoter. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot assay indicated that the expression of CTLA4-Ig remained skin-specific and relatively constant compared to the internal control protein, AKT, through seven generations. The presence and concentration of the hCTLA4-Ig protein in transgenic mouse sera was determined by enzyme-linked immunosorbent assay (ELISA), and the results indicated that the serum CTLA4-Ig concentration also remained constant through generations. Survival of transgenic mouse skins grafted onto rat wounds was remarkably prolonged compared to that of wild-type skins from the same mouse strain, and remained comparable among all seven generations. This suggested that the bioactive hCTLA4-Ig protein was stably expressed in transgenical mice through at least seven generations, which was consistent with the stable skin-specific CTLA4-Ig expression.The results demonstrated that the transgenic expression of hCTLA4-Ig in skin driven by the K14 promoter remained constant through generations, and a transgenic line can be established to provide transgenic skin with extended survival reproducibly.

HER2 overexpression and amplification as a potential therapeutic target in colorectal cancer: analysis of 3256 patients enrolled in the QUASAR, FOCUS and PICCOLO colorectal cancer trials.

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Richman, Susan D; Southward, Katie; Chambers, Philip; Cross, Debra; Barrett, Jennifer; Hemmings, Gemma; Taylor, Morag; Wood, Henry; Hutchins, Gordon; Foster, Joseph M; Oumie, Assa; Spink, Karen G; Brown, Sarah R; Jones, Marc; Kerr, David; Handley, Kelly; Gray, Richard; Seymour, Matthew; Quirke, Philip

2016-03-01

HER2 overexpression/amplification is linked to trastuzumab response in breast/gastric cancers. One suggested anti-EGFR resistance mechanism in colorectal cancer (CRC) is aberrant MEK-AKT pathway activation through HER2 up-regulation. We assessed HER2-amplification/overexpression in stage II-III and IV CRC patients, assessing relationships to KRAS/BRAF and outcome. Pathological material was obtained from 1914 patients in the QUASAR stage II-III trial and 1342 patients in stage IV trials (FOCUS and PICCOLO). Tissue microarrays were created for HER2 immunohistochemistry. HER2-amplification was assessed using FISH and copy number variation. KRAS/BRAF mutation status was assessed by pyrosequencing. Progression-free survival (PFS) and overall survival (OS) data were obtained for FOCUS/PICCOLO and recurrence and mortality for QUASAR; 29/1342 (2.2%) stage IV and 25/1914 (1.3%) stage II-III tumours showed HER2 protein overexpression. Of the HER2-overexpressing cases, 27/28 (96.4%) stage IV tumours and 20/24 (83.3%) stage II-III tumours demonstrated HER2 amplification by FISH; 41/47 (87.2%) also showed copy number gains. HER2-overexpression was associated with KRAS/BRAF wild-type (WT) status at all stages: in 5.2% WT versus 1.0% mutated tumours (p < 0.0001) in stage IV and 2.1% versus 0.2% in stage II-III tumours (p = 0.01), respectively. HER2 was not associated with OS or PFS. At stage II-III, there was no significant correlation between HER2 overexpression and 5FU/FA response. A higher proportion of HER2-overexpressing cases experienced recurrence, but the difference was not significant. HER2-amplification/overexpression is identifiable by immunohistochemistry, occurring infrequently in stage II-III CRC, rising in stage IV and further in KRAS/BRAF WT tumours. The value of HER2-targeted therapy in patients with HER2-amplified CRC must be tested in a clinical trial. © 2015 The Authors. Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society

A Novel mouse model of enhanced proteostasis: Full-length human heat shock factor 1 transgenic mice

International Nuclear Information System (INIS)

Pierce, Anson; Wei, Rochelle; Halade, Dipti; Yoo, Si-Eun; Ran, Qitao; Richardson, Arlan

2010-01-01

Research highlights: → Development of mouse overexpressing native human HSF1 in all tissues including CNS. → HSF1 overexpression enhances heat shock response at whole-animal and cellular level. → HSF1 overexpression protects from polyglutamine toxicity and favors aggresomes. → HSF1 overexpression enhances proteostasis at the whole-animal and cellular level. -- Abstract: The heat shock response (HSR) is controlled by the master transcriptional regulator heat shock factor 1 (HSF1). HSF1 maintains proteostasis and resistance to stress through production of heat shock proteins (HSPs). No transgenic model exists that overexpresses HSF1 in tissues of the central nervous system (CNS). We generated a transgenic mouse overexpressing full-length non-mutant HSF1 and observed a 2-4-fold increase in HSF1 mRNA and protein expression in all tissues studied of HSF1 transgenic (HSF1 +/0 ) mice compared to wild type (WT) littermates, including several regions of the CNS. Basal expression of HSP70 and 90 showed only mild tissue-specific changes; however, in response to forced exercise, the skeletal muscle HSR was more elevated in HSF1 +/0 mice compared to WT littermates and in fibroblasts following heat shock, as indicated by levels of inducible HSP70 mRNA and protein. HSF1 +/0 cells elicited a significantly more robust HSR in response to expression of the 82 repeat polyglutamine-YFP fusion construct (Q82YFP) and maintained proteasome-dependent processing of Q82YFP compared to WT fibroblasts. Overexpression of HSF1 was associated with fewer, but larger Q82YFP aggregates resembling aggresomes in HSF1 +/0 cells, and increased viability. Therefore, our data demonstrate that tissues and cells from mice overexpressing full-length non-mutant HSF1 exhibit enhanced proteostasis.

Intestine-targeted DGAT1 inhibition improves obesity and insulin resistance without skin aberrations in mice.

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Naoto Tsuda

Full Text Available OBJECTIVE: Diacylglycerol O-acyltransferase 1 (DGAT1 catalyzes the final committed step in triglyceride biosynthesis. DGAT1 null mice are known to be resistant to diet-induced obesity, and more insulin sensitive relative to the wild-type; however, the mice exhibit abnormalities in the skin. This work determined whether the intestine-targeted DGAT1 inhibitor could improve obesity and insulin resistance without skin aberrations in mice. DESIGN AND METHODS: We synthesized 2 DGAT1 inhibitors: Compound A, described in the patent application from the Japan Tobacco, and Compound B (A-922500, reported by Abbott Laboratories. Both compounds were evaluated for inhibitory activities against DGAT1 enzymes and effects on the skin in mice in vivo. Compound B was further investigated for effects on obesity and insulin resistance in diet-induced-obese (DIO mice. RESULTS: The 2 compounds comparably inhibited the DGAT1 enzyme activity and the cellular triglyceride synthesis in vitro, while they showed different distribution patterns in mice in vivo. Compound A, which distributed systemically, caused skin aberrations, while Compound B, which preferentially distributed to the intestine, improved obesity and insulin resistance without skin aberrations in DIO mice. CONCLUSIONS: Our results suggest that the intestine is the key tissue in which DGAT1 plays a role in promoting obesity and insulin resistance.

Characterization of a sensitive mouse Aβ40 PD biomarker assay for Alzheimer's disease drug development in wild-type mice.

Science.gov (United States)

Lu, Yanmei; Hoyte, Kwame; Montgomery, William H; Luk, Wilman; He, Dongping; Meilandt, William J; Zuchero, Y Joy Yu; Atwal, Jasvinder K; Scearce-Levie, Kimberly; Watts, Ryan J; DeForge, Laura E

2016-05-01

Transgenic mice that overexpress human amyloid precursor protein with Swedish or London (APPswe or APPlon) mutations have been widely used for preclinical Alzheimer's disease (AD) drug development. AD patients, however, rarely possess these mutations or overexpress APP. We developed a sensitive ELISA that specifically and accurately measures low levels of endogenous Aβ40 in mouse plasma, brain and CSF. In wild-type mice treated with a bispecific anti-TfR/BACE1 antibody, significant Aβ reductions were observed in the periphery and the brain. APPlon transgenic mice showed a slightly less reduction, whereas APPswe mice did not have any decrease. This sensitive and well-characterized mouse Aβ40 assay enables the use of wild-type mice for preclinical PK/PD and efficacy studies of potential AD therapeutics.

Inducible targeting of CNS astrocytes in Aldh1l1-CreERT2 BAC transgenic mice.

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Winchenbach, Jan; Düking, Tim; Berghoff, Stefan A; Stumpf, Sina K; Hülsmann, Swen; Nave, Klaus-Armin; Saher, Gesine

2016-01-01

Background: Studying astrocytes in higher brain functions has been hampered by the lack of genetic tools for the efficient expression of inducible Cre recombinase throughout the CNS, including the neocortex. Methods: Therefore, we generated BAC transgenic mice, in which CreERT2 is expressed under control of the Aldh1l1 regulatory region. Results: When crossbred to Cre reporter mice, adult Aldh1l1-CreERT2 mice show efficient gene targeting in astrocytes. No such Cre-mediated recombination was detectable in CNS neurons, oligodendrocytes, and microglia. As expected, Aldh1l1-CreERT2 expression was evident in several peripheral organs, including liver and kidney. Conclusions: Taken together, Aldh1l1-CreERT2 mice are a useful tool for studying astrocytes in neurovascular coupling, brain metabolism, synaptic plasticity and other aspects of neuron-glia interactions.

The collagen receptor uPARAP/Endo180 as a novel target for antibody-drug conjugate mediated treatment of mesenchymal and leukemic cancers

DEFF Research Database (Denmark)

Nielsen, Christoffer Fagernæs; van Putten, Sander Maarten; Lund, Ida Katrine

2017-01-01

A key task in developing the field of personalized cancer therapy is the identification of novel molecular targets that enable treatment of cancers not susceptible to other means of specific therapy. The collagen receptor uPARAP/Endo180 is overexpressed by malignant cells in several non-epithelia......A key task in developing the field of personalized cancer therapy is the identification of novel molecular targets that enable treatment of cancers not susceptible to other means of specific therapy. The collagen receptor uPARAP/Endo180 is overexpressed by malignant cells in several non...... into the endosomal-lysosomal system, thus opening a potential route of entry into receptor-positive cells. This combination of specific expression and endocytic function appears well suited for targeting of uPARAP/Endo180-positive cancers by antibody-drug conjugate (ADC) mediated drug delivery. Therefore, we...... model with human uPARAP/Endo180-positive leukemic cells, obtaining a complete cure of all tested mice following intravenous ADC treatment with no sign of adverse effects. Our study identifies uPARAP/Endo180 as a promising target for novel therapy against several highly malignant cancer types....

Effect of Lowering Asymmetric Dimethylarginine (ADMA on Vascular Pathology in Atherosclerotic ApoE-Deficient Mice with Reduced Renal Mass

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Johannes Jacobi

2014-03-01

Full Text Available The purpose of the work was to study the impact of the endogenous nitric oxide synthase (NOS inhibitor asymmetric dimethylarginine (ADMA and its degrading enzyme, dimethylarginine dimethylaminohydrolase (DDAH1, on atherosclerosis in subtotally nephrectomized (SNX ApoE-deficient mice. Male DDAH1 transgenic mice (TG, n = 39 and C57Bl/6J wild-type littermates (WT, n = 27 with or without the deletion of the ApoE gene underwent SNX at the age of eight weeks. Animals were sacrificed at 12 months of age, and blood chemistry, as well as the extent of atherosclerosis within the entire aorta were analyzed. Sham treated (no renal mass reduction ApoE-competent DDAH1 transgenic and wild-type littermates (n = 11 served as a control group. Overexpression of DDAH1 was associated with significantly lower ADMA levels in all treatment groups. Surprisingly, SNX mice did not exhibit higher ADMA levels compared to sham treated control mice. Furthermore, the degree of atherosclerosis in ApoE-deficient mice with SNX was similar in mice with or without overexpression of DDAH1. Overexpression of the ADMA degrading enzyme, DDAH1, did not ameliorate atherosclerosis in ApoE-deficient SNX mice. Furthermore, SNX in mice had no impact on ADMA levels, suggesting a minor role of this molecule in chronic kidney disease (CKD in this mouse model.

Overexpression, purification and crystallization of the tetrameric form of SorC sorbitol operon regulator

International Nuclear Information System (INIS)

Sanctis, Daniele de; Rêgo, Ana T.; Marçal, David; McVey, Colin E.; Carrondo, Maria A.; Enguita, Francisco J.

2007-01-01

The sorbitol operon regulator from K. pneumoniae has been overexpressed in E. coli, purified and crystallized. Diffraction data were collected to 3.2 Å. The sorbitol operon regulator (SorC) regulates the metabolism of l-sorbose in Klebsiella pneumonia. SorC was overexpressed in Escherichia coli and purified, and crystals were obtained of a tetrameric form. A single crystal showed X-ray diffraction to 3.20 Å. The crystal belongs to space group P2 1 2 1 2 1 , with unit-cell parameters a = 91.6, b = 113.3, c = 184.1 Å. Analysis of the molecular-replacement solution indicates the presence of four SorC molecules in the asymmetric unit

Microtubule-targeting drugs rescue axonal swellings in cortical neurons from spastin knockout mice

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Coralie Fassier

2013-01-01

Mutations in SPG4, encoding the microtubule-severing protein spastin, are responsible for the most frequent form of hereditary spastic paraplegia (HSP, a heterogeneous group of genetic diseases characterized by degeneration of the corticospinal tracts. We previously reported that mice harboring a deletion in Spg4, generating a premature stop codon, develop progressive axonal degeneration characterized by focal axonal swellings associated with impaired axonal transport. To further characterize the molecular and cellular mechanisms underlying this mutant phenotype, we have assessed microtubule dynamics and axonal transport in primary cultures of cortical neurons from spastin-mutant mice. We show an early and marked impairment of microtubule dynamics all along the axons of spastin-deficient cortical neurons, which is likely to be responsible for the occurrence of axonal swellings and cargo stalling. Our analysis also reveals that a modulation of microtubule dynamics by microtubule-targeting drugs rescues the mutant phenotype of cortical neurons. Together, these results contribute to a better understanding of the pathogenesis of SPG4-linked HSP and ascertain the influence of microtubule-targeted drugs on the early axonal phenotype in a mouse model of the disease.

Trib1 Is Overexpressed in Systemic Lupus Erythematosus, While It Regulates Immunoglobulin Production in Murine B Cells

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Léa Simoni

2018-03-01

Full Text Available Systemic lupus erythematosus (SLE is a severe and heterogeneous autoimmune disease with a complex genetic etiology, characterized by the production of various pathogenic autoantibodies, which participate in end-organ damages. The majority of human SLE occurs in adults as a polygenic disease, and clinical flares interspersed with silent phases of various lengths characterize the usual evolution of the disease in time. Trying to understand the mechanism of the different phenotypic traits of the disease, and considering the central role of B cells in SLE, we previously performed a detailed wide analysis of gene expression variation in B cells from quiescent SLE patients. This analysis pointed out an overexpression of TRIB1. TRIB1 is a pseudokinase that has been implicated in the development of leukemia and also metabolic disorders. It is hypothesized that Trib1 plays an adapter or scaffold function in signaling pathways, notably in MAPK pathways. Therefore, we planned to understand the functional significance of TRIB1 overexpression in B cells in SLE. We produced a new knock-in model with B-cell-specific overexpression of Trib1. We showed that overexpression of Trib1 specifically in B cells does not impact B cell development nor induce any development of SLE symptoms in the mice. By contrast, Trib1 has a negative regulatory function on the production of immunoglobulins, notably IgG1, but also on the production of autoantibodies in an induced model. We observed a decrease of Erk activation in BCR-stimulated Trib1 overexpressing B cells. Finally, we searched for Trib1 partners in B cells by proteomic analysis in order to explore the regulatory function of Trib1 in B cells. Interestingly, we find an interaction between Trib1 and CD72, a negative regulator of B cells whose deficiency in mice leads to the development of autoimmunity. In conclusion, the overexpression of Trib1 could be one of the molecular pathways implicated in the negative regulation

Overexpression of Lin28b in Neural Stem Cells is Insufficient for Brain Tumor Formation, but Induces Pathological Lobulation of the Developing Cerebellum.

Science.gov (United States)

Wefers, Annika K; Lindner, Sven; Schulte, Johannes H; Schüller, Ulrich

2017-02-01

LIN28B is a homologue of the RNA-binding protein LIN28A and regulates gene expression during development and carcinogenesis. It is strongly upregulated in a variety of brain tumors, such as medulloblastoma, embryonal tumor with multilayered rosettes (ETMR), atypical teratoid/rhabdoid tumor (AT/RT), or glioblastoma, but the effect of an in vivo overexpression of LIN28B on the developing central nervous system is unknown. We generated transgenic mice that either overexpressed Lin28b in Math1-positive cerebellar granule neuron precursors or in a broad range of Nestin-positive neural precursors. Sections of the cerebellar vermis from adult Math1-Cre::lsl-Lin28b mice had an additional subfissure in lobule IV. Vermes from p0 and p7 Nestin-Cre::lsl-Lin28b mice appeared normal, but we found a pronounced vermal hypersublobulation at p15 and p21 in these mice. Also, the external granule cell layer (EGL) was thicker at p15 than in controls, contained more proliferating cells, and persisted up to p21. Consistently, some Pax6- and NeuN-positive cells were present in the EGL of Nestin-Cre::lsl-Lin28b mice even at p21, and we detected more NeuN-positive granule neuron precursors in the molecular layer (ML) as compared to control. Finally, we found some residual Pax2-positive precursors of inhibitory interneurons in the ML of Nestin-Cre::lsl-Lin28b mice at p21, which have already disappeared in controls. We conclude that while overexpression of LIN28B in Nestin-positive cells does not lead to tumor formation, it results in a protracted development of granule cells and inhibitory interneurons and leads to a hypersublobulation of the cerebellar vermis.