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Sample records for lysosomal protease cathepsin

  1. Cathepsin proteases in Toxoplasma gondii

    OpenAIRE

    Dou, Zhicheng; Carruthers, Vern B.

    2011-01-01

    Cysteine proteases are important for the growth and survival of apicomplexan parasites that infect humans. The apicomplexan Toxoplasma gondii expresses five members of the C1 family of cysteine proteases, including one cathepsin L-like (TgCPL), one cathepsin B-like (TgCPB), and three cathepsin C-like (TgCPC1, 2 and 3) proteases. Recent genetic, biochemical and structural studies reveal that cathepsins function in microneme and rhoptry protein maturation, host cell invasion, replication, and n...

  2. Cathepsin proteases in Toxoplasma gondii

    Science.gov (United States)

    Dou, Zhicheng; Carruthers, Vern B.

    2014-01-01

    Cysteine proteases are important for the growth and survival of apicomplexan parasites that infect humans. The apicomplexan Toxoplasma gondii expresses five members of the C1 family of cysteine proteases, including one cathepsin L-like (TgCPL), one cathepsin B-like (TgCPB), and three cathepsin C-like (TgCPC1, 2 and 3) proteases. Recent genetic, biochemical and structural studies reveal that cathepsins function in microneme and rhoptry protein maturation, host cell invasion, replication, and nutrient acquisition.. Here, we review the key features and roles of T. gondii cathepsins and discuss the therapeutic potential for specific inhibitor development. PMID:21660658

  3. Cathepsin inhibition-induced lysosomal dysfunction enhances pancreatic beta-cell apoptosis in high glucose.

    Science.gov (United States)

    Jung, Minjeong; Lee, Jaemeun; Seo, Hye-Young; Lim, Ji Sun; Kim, Eun-Kyoung

    2015-01-01

    Autophagy is a lysosomal degradative pathway that plays an important role in maintaining cellular homeostasis. We previously showed that the inhibition of autophagy causes pancreatic β-cell apoptosis, suggesting that autophagy is a protective mechanism for the survival of pancreatic β-cells. The current study demonstrates that treatment with inhibitors and knockdown of the lysosomal cysteine proteases such as cathepsins B and L impair autophagy, enhancing the caspase-dependent apoptosis of INS-1 cells and islets upon exposure to high concentration of glucose. Interestingly, treatment with cathepsin B and L inhibitors prevented the proteolytic processing of cathepsins B, D and L, as evidenced by gradual accumulation of the respective pro-forms. Of note, inhibition of aspartic cathepsins had no effect on autophagy and cell viability, suggesting the selective role of cathepsins B and L in the regulation of β-cell autophagy and apoptosis. Lysosomal localization of accumulated pro-cathepsins in the presence of cathepsin B and L inhibitors was verified via immunocytochemistry and lysosomal fractionation. Lysotracker staining indicated that cathepsin B and L inhibitors led to the formation of severely enlarged lysosomes in a time-dependent manner. The abnormal accumulation of pro-cathepsins following treatment with inhibitors of cathepsins B and L suppressed normal lysosomal degradation and the processing of lysosomal enzymes, leading to lysosomal dysfunction. Collectively, our findings suggest that cathepsin defects following the inhibition of cathepsin B and L result in lysosomal dysfunction and consequent cell death in pancreatic β-cells.

  4. Importance of lysosomal cysteine proteases in lung disease

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    Chapman Harold A

    2000-11-01

    Full Text Available Abstract The human lysosomal cysteine proteases are a family of 11 proteases whose members include cathepsins B, C, H, L, and S. The biology of these proteases was largely ignored for decades because of their lysosomal location and the belief that their function was limited to the terminal degradation of proteins. In the past 10 years, this view has changed as these proteases have been found to have specific functions within cells. This review highlights some of these functions, specifically their roles in matrix remodeling and in regulating the immune response, and their relationship to lung diseases.

  5. Reduction of mutant huntingtin accumulation and toxicity by lysosomal cathepsins D and B in neurons

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    Ouyang Xiaosen

    2011-06-01

    Full Text Available Abstract Background Huntington's disease is caused by aggregation of mutant huntingtin (mHtt protein containing more than a 36 polyQ repeat. Upregulation of macroautophagy was suggested as a neuroprotective strategy to degrade mutant huntingtin. However, macroautophagy initiation has been shown to be highly efficient in neurons whereas lysosomal activities are rate limiting. The role of the lysosomal and other proteases in Huntington is not clear. Some studies suggest that certain protease activities may contribute to toxicity whereas others are consistent with protection. These discrepancies may be due to a number of mechanisms including distinct effects of the specific intermediate digestion products of mutant huntingtin generated by different proteases. These observations suggested a critical need to investigate the consequence of upregulation of individual lysosomal enzyme in mutant huntingtin accumulation and toxicity. Results In this study, we used molecular approaches to enhance lysosomal protease activities and examined their effects on mutant huntingtin level and toxicity. We found that enhanced expression of lysosomal cathepsins D and B resulted in their increased enzymatic activities and reduced both full-length and fragmented huntingtin in transfected HEK cells. Furthermore, enhanced expression of cathepsin D or B protected against mutant huntingtin toxicity in primary neurons, and their neuroprotection is dependent on macroautophagy. Conclusions These observations demonstrate a neuroprotective effect of enhancing lysosomal cathepsins in reducing mutant huntingtin level and toxicity in transfected cells. They highlight the potential importance of neuroprotection mediated by cathepsin D or B through macroautophagy.

  6. UVA causes dual inactivation of cathepsin B and L underlying lysosomal dysfunction in human dermal fibroblasts.

    Science.gov (United States)

    Lamore, Sarah D; Wondrak, Georg T

    2013-06-05

    Cutaneous exposure to chronic solar UVA-radiation is a causative factor in photocarcinogenesis and photoaging. Recently, we have identified the thiol-dependent cysteine-protease cathepsin B as a novel UVA-target undergoing photo-oxidative inactivation upstream of autophagic-lysosomal dysfunction in fibroblasts. In this study, we examined UVA effects on a wider range of cathepsins and explored the occurrence of UVA-induced cathepsin inactivation in other cultured skin cell types. In dermal fibroblasts, chronic exposure to non-cytotoxic doses of UVA caused pronounced inactivation of the lysosomal cysteine-proteases cathepsin B and L, effects not observed in primary keratinocytes and occurring only to a minor extent in primary melanocytes. In order to determine if UVA-induced lysosomal impairment requires single or dual inactivation of cathepsin B and/or L, we used a genetic approach (siRNA) to selectively downregulate enzymatic activity of these target cathepsins. Monitoring an established set of protein markers (including LAMP1, LC3-II, and p62) and cell ultrastructural changes detected by electron microscopy, we observed that only dual genetic antagonism (targeting both CTSB and CTSL expression) could mimic UVA-induced autophagic-lysosomal alterations, whereas single knockdown (targeting CTSB or CTSL only) did not display 'UVA-mimetic' effects failing to reproduce the UVA-induced phenotype. Taken together, our data demonstrate that chronic UVA inhibits both cathepsin B and L enzymatic activity and that dual inactivation of both enzymes is a causative factor underlying UVA-induced impairment of lysosomal function in dermal fibroblasts.

  7. Inhibitors of lysosomal cysteine proteases

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    Lyanna O. L.

    2011-04-01

    Full Text Available The review is devoted to the inhibitors of cysteine proteinases which are believed to be very important in many biochemical processes of living organisms. They participate in the development and progression of numerous diseases that involve abnormal protein turnover. One of the main regulators of these proteinases is their specific inhibitors: cystatins. The aim of this review was to present current knowledge about endogenous inhibitors of lysosomal cysteine proteases and their synthetic analogs.

  8. Lysosomal exoglycosidases and cathepsin D in colon adenocarcinoma.

    Science.gov (United States)

    Waszkiewicz, Napoleon; Zalewska-Szajda, Beata; Szajda, Sławomir D; Kępka, Alina; Waszkiewicz, Magdalena; Roszkowska-Jakimiec, Wiesława; Wojewódzka-Żeleźniakowicz, Marzena; Milewska, Anna J; Dadan, Jacek; Szulc, Agata; Zwierz, Krzysztof; Ladny, Jerzy R

    2012-01-01

    Changes in the structure of membrane glycoconjugates and activity of glycosidases and proteases are important in tumor formation. The aim of the study was to compare the specific activity of lysosomal exoglycosidases: N-acetyl-β-D-hexosaminidase (HEX), its isoenzymes A (HEX A) and B (HEX B), β-D-galactosidase (GAL), α-fucosidase (FUC), and α-mannosidase (MAN) with the activity of cathepsin D (CD) in serum, urine, and carcinoma tissue of patients with colon adenocarcinoma. The specific activity of HEX, HEX A, HEX B, GAL, FUC, MAN, and CD was assayed in serum, urine, and carcinoma tissue of 12 patients with colon adenocarcinoma. Lysosomal exoglycosidases and CD have similar specific activity in colon adenocarcinoma tissue and urine, which is higher than their activity in serum (with the exception of the highest specific activity of CD in urine). A positive correlation was observed between the specific activity of CD and that of HEX, HEX A, FUC, and MAN in the carcinoma tissue and urine as well as between CD and GAL in the urine of patients with colon adenocarcinoma. Negative correlations were observed between protein levels and the specific activity of HEX, HEX A, FUC, MAN, and CD in the carcinoma tissue and urine, and between protein levels and GAL in urine. Increased degradation and remodeling of glycoconjugates in the colon adenocarcinoma tissue is reflected by increased specific activity of exoglycosidases and CD. The results suggest a strong effect of exoglycosidase action on tissue degradation and a potential role of exoglycosidases in the initiation of proteolysis.

  9. Molecular characterization and expression analysis of Cathepsin B and L cysteine proteases from rock bream (Oplegnathus fasciatus).

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    Whang, Ilson; De Zoysa, Mahanama; Nikapitiya, Chamilani; Lee, Youngdeuk; Kim, Yucheol; Lee, Sukkyoung; Oh, Chulhong; Jung, Sung-Ju; Oh, Myung-Joo; Choi, Cheol Young; Yeo, Sang-Yeob; Kim, Bong-Seok; Kim, Se-Jae; Lee, Jehee

    2011-03-01

    Cathepsins are lysosomal cysteine proteases of the papain family that play an important role in intracellular protein degradation and turn over within the lysosomal system. In the present study, full-length sequences of cathepsin B (RbCathepsin B) and L (RbCathepsin L) were identified after transcriptome sequencing of rock bream Oplegnathus fasciatus mixed tissue cDNA. Cathepsin B was composed of 330 amino acid residues with 36 kDa predicted molecular mass. RbCathepsin L contained 336 amino acid residues encoding for a 38 kDa predicted molecular mass protein. The sequencing analysis results showed that both cathepsin B and L contain the characteristic papain family cysteine protease signature and active sites for the eukaryotic thiol proteases of cysteine, asparagine and histidine. In addition, RbCathepsin L contained EF hand Ca(2+) binding and cathepsin propeptide inhibitor domains. The rock bream cathepsin B and L showed the highest amino acid identity of 90 and 95% to Lutjanus argentimaculatus cathepsin B and Lates calcarifer cathepsin L, respectively. By phylogenetic analysis, cathepsin B and L exhibited a high degree of evolutionary relationship to respective cathepsin family members of the papain superfamily. Quantitative real-time RT-PCR analysis results confirmed that the expression of cathepsin B and L genes was constitutive in all examined tissues isolated from un-induced rock bream. Moreover, activation of RbCathepsin B and L mRNA was observed in both lipopolysaccharide (LPS) and Edwardsiella tarda challenged liver and blood cells, indicating a role of immune response in rock bream.

  10. Azadirachtin-induced apoptosis involves lysosomal membrane permeabilization and cathepsin L release in Spodoptera frugiperda Sf9 cells.

    Science.gov (United States)

    Wang, Zheng; Cheng, Xingan; Meng, Qianqian; Wang, Peidan; Shu, Benshui; Hu, Qiongbo; Hu, Meiying; Zhong, Guohua

    2015-07-01

    Azadirachtin as a kind of botanical insecticide has been widely used in pest control. We previously reported that azadirachtin could induce apoptosis of Spodoptera litura cultured cell line Sl-1, which involves in the up-regulation of P53 protein. However, the detailed mechanism of azadirachtin-induced apoptosis is not clearly understood in insect cultured cells. The aim of the present study was to address the involvement of lysosome and lysosomal protease in azadirachtin-induced apoptosis in Sf9 cells. The result confirmed that azadirachtin indeed inhibited proliferation and induced apoptosis. The lysosomes were divided into different types as time-dependent manner, which suggested that changes of lysosomes were necessarily physiological processes in azadirachtin-induced apoptosis in Sf9 cells. Interestingly, we noticed that azadirachtin could trigger lysosomal membrane permeabilization and cathepsin L releasing to cytosol. Z-FF-FMK (a cathepsin L inhibitor), but not CA-074me (a cathepsin B inhibitor), could effectively hinder the apoptosis induced by azadirachtin in Sf9 cells. Meanwhile, the activity of caspase-3 could also be inactivated by the inhibition of cathepsin L enzymatic activity induced by Z-FF-FMK. Taken together, our findings suggest that azadirachtin could induce apoptosis in Sf9 cells in a lysosomal pathway, and cathepsin L plays a pro-apoptosis role in this process through releasing to cytosol and activating caspase-3.

  11. Redistribution of cathepsin B activity from the endosomal-lysosomal pathway in chick intestine within 3 min of calcium absorption.

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    Nemere, I; Norman, A W

    1991-06-01

    Earlier work has suggested that calcium-containing lysosomes are involved in 1,25-dihydroxyvitamin D3 (1,25(OH)2D3)-stimulated intestinal absorption of the divalent cation. In the present report immunofluorescent labelling studies on fixed frozen sections of chick intestine were undertaken to determine whether lysosomes could respond to calcium transport conditions in less than 5 min. Tissue prepared from vitamin D-deficient chicks dosed with vehicle or 1.3 nmol of 1,25(OH)2D3 15 h prior to use was immunofluorescently labelled for cathepsin B, a lysosomal protease. In the absence of calcium absorption, punctate staining was found in the region below the terminal web, and more diffusely in the cytoplasm. The intensity of staining was noticeably greater in sections from 1,25(OH)2D3-treated than control chicks. In sections prepared after 3 min of calcium absorption, cathepsin B staining was localized near the basal and lateral membranes of the epithelial cells. After 30 min of transport, the protease was found in the villus core regardless of vitamin D status; however, immunoreactivity within the epithelial cells of 1,25(OH)2D3-treated chick intestine had returned to pretransport intensity, whereas that of controls had not. To further investigate the specificity of the cathepsin B antibody, the intracellular compartmentalization of the protease was determined by biochemical methods. Using dosing procedures and calcium transport times equivalent to those for the immunofluorescent studies mucosae were collected by scraping, homogenized, and subcellular fractions prepared by a combination of differential and Percoll gradient centrifugation. In the absence of calcium transport, cathepsin B-specific activity was enhanced in whole homogenates, endocytic vesicles, and a lysosomal fraction prepared from intestinal epithelium of 1,25(OH)2D3-treated chicks, relative to vitamin D-deficient controls. After 3 min of calcium absorption, a profound (approximately 4-fold) decrease in

  12. Cathepsin B modulates lysosomal biogenesis and host defense against Francisella novicida infection.

    Science.gov (United States)

    Qi, Xiaopeng; Man, Si Ming; Malireddi, R K Subbarao; Karki, Rajendra; Lupfer, Christopher; Gurung, Prajwal; Neale, Geoffrey; Guy, Clifford S; Lamkanfi, Mohamed; Kanneganti, Thirumala-Devi

    2016-09-19

    Lysosomal cathepsins regulate an exquisite range of biological functions, and their deregulation is associated with inflammatory, metabolic, and degenerative diseases in humans. In this study, we identified a key cell-intrinsic role for cathepsin B as a negative feedback regulator of lysosomal biogenesis and autophagy. Mice and macrophages lacking cathepsin B activity had increased resistance to the cytosolic bacterial pathogen Francisella novicida Genetic deletion or pharmacological inhibition of cathepsin B down-regulated mechanistic target of rapamycin activity and prevented cleavage of the lysosomal calcium channel TRPML1. These events drove transcription of lysosomal and autophagy genes via transcription factor EB, which increased lysosomal biogenesis and activation of autophagy initiation kinase ULK1 for clearance of the bacteria. Our results identified a fundamental biological function of cathepsin B in providing a checkpoint for homeostatic maintenance of lysosome populations and basic recycling functions in the cell.

  13. Actin-binding protein coronin 1A controls osteoclastic bone resorption by regulating lysosomal secretion of cathepsin K

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    Ohmae, Saori; Noma, Naruto; Toyomoto, Masayasu; Shinohara, Masahiro; Takeiri, Masatoshi; Fuji, Hiroaki; Takemoto, Kenji; Iwaisako, Keiko; Fujita, Tomoko; Takeda, Norihiko; Kawatani, Makoto; Aoyama, Mineyoshi; Hagiwara, Masatoshi; Ishihama, Yasushi; Asagiri, Masataka

    2017-01-01

    Osteoclasts degrade bone matrix proteins via the secretion of lysosomal enzymes. However, the precise mechanisms by which lysosomal components are transported and fused to the bone-apposed plasma membrane, termed ruffled border membrane, remain elusive. Here, we identified coronin 1A as a negative regulator of exocytotic release of cathepsin K, one of the most important bone-degrading enzymes in osteoclasts. The modulation of coronin 1A expression did not alter osteoclast differentiation and extracellular acidification, but strongly affected the secretion of cathepsin K and osteoclast bone-resorption activity, suggesting the coronin 1A-mediated regulation of lysosomal trafficking and protease exocytosis. Further analyses suggested that coronin 1A prevented the lipidation-mediated sorting of the autophagy-related protein LC3 to the ruffled border and attenuated lysosome–plasma membrane fusion. In this process, the interactions between coronin 1A and actin were crucial. Collectively, our findings indicate that coronin 1A is a pivotal component that regulates lysosomal fusion and the secretion pathway in osteoclast-lineage cells and may provide a novel therapeutic target for bone diseases. PMID:28300073

  14. Cathepsin B protease is required for metamorphism in silkworm,Bombyx mori

    Institute of Scientific and Technical Information of China (English)

    Gen-Hong Wang; Chun Liu; Qing-You Xia; Xing-Fu Zha; Jie Chen; Liang Jiang

    2008-01-01

    Cathepsin B belongs to lysosomal cysteine protease of the papain family.Temporal and spatial expression analysis of cathepsin B of Bombyx mori (BmCtB) was carried out based on Expression Sequence Tags (ESTs) data,oligonucleotide microarray,reverse transcription polymerase chain reaction (RT-PCR) and quantitative real-time PCR.Expression of BmCtB was observed in all of the tissues and stages.Among the 10 tested tissues,the fat body and posterior silk gland are the two most enriched tissues with BmCtB.During Bombyx development,there was an expression fastigium of BmCtB during metamorphosis.RNA interference was used to suppress the expression of cathepsin B during metamorphosis.Significant developmental defective phenotypes were obtained in the RNAi treated group.The dramatically reduced expression of BmCtB was confirmed by Northern blot and quantitative real-time PCR.These evidences strongly suggest cathepsin B proteinase was predominantly involved in the metabolism process of fat body and the posterior silk gland and was critical for metamorphism and development of silkworm,Bombyx mori.

  15. Cathepsin B Activity Initiates Apoptosis via Digestive Protease Activation in Pancreatic Acinar Cells and Experimental Pancreatitis.

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    Sendler, Matthias; Maertin, Sandrina; John, Daniel; Persike, Maria; Weiss, F Ulrich; Krüger, Burkhard; Wartmann, Thomas; Wagh, Preshit; Halangk, Walter; Schaschke, Norbert; Mayerle, Julia; Lerch, Markus M

    2016-07-08

    Pancreatitis is associated with premature activation of digestive proteases in the pancreas. The lysosomal hydrolase cathepsin B (CTSB) is a known activator of trypsinogen, and its deletion reduces disease severity in experimental pancreatitis. Here we studied the activation mechanism and subcellular compartment in which CTSB regulates protease activation and cellular injury. Cholecystokinin (CCK) increased the activity of CTSB, cathepsin L, trypsin, chymotrypsin, and caspase 3 in vivo and in vitro and induced redistribution of CTSB to a secretory vesicle-enriched fraction. Neither CTSB protein nor activity redistributed to the cytosol, where the CTSB inhibitors cystatin-B/C were abundantly present. Deletion of CTSB reduced and deletion of cathepsin L increased intracellular trypsin activation. CTSB deletion also abolished CCK-induced caspase 3 activation, apoptosis-inducing factor, as well as X-linked inhibitor of apoptosis protein degradation, but these depended on trypsinogen activation via CTSB. Raising the vesicular pH, but not trypsin inhibition, reduced CTSB activity. Trypsin inhibition did not affect apoptosis in hepatocytes. Deletion of CTSB affected apoptotic but not necrotic acinar cell death. In summary, CTSB in pancreatitis undergoes activation in a secretory, vesicular, and acidic compartment where it activates trypsinogen. Its deletion or inhibition regulates acinar cell apoptosis but not necrosis in two models of pancreatitis. Caspase 3-mediated apoptosis depends on intravesicular trypsinogen activation induced by CTSB, not CTSB activity directly, and this mechanism is pancreas-specific.

  16. Loss of lysosomal ion channel transient receptor potential channel mucolipin-1 (TRPML1) leads to cathepsin B-dependent apoptosis.

    Science.gov (United States)

    Colletti, Grace A; Miedel, Mark T; Quinn, James; Andharia, Neel; Weisz, Ora A; Kiselyov, Kirill

    2012-03-09

    Mucolipidosis type IV (MLIV) is a lysosomal storage disease caused by mutations in the gene MCOLN1, which codes for the transient receptor potential family ion channel TRPML1. MLIV has an early onset and is characterized by developmental delays, motor and cognitive deficiencies, gastric abnormalities, retinal degeneration, and corneal cloudiness. The degenerative aspects of MLIV have been attributed to cell death, whose mechanisms remain to be delineated in MLIV and in most other storage diseases. Here we report that an acute siRNA-mediated loss of TRPML1 specifically causes a leak of lysosomal protease cathepsin B (CatB) into the cytoplasm. CatB leak is associated with apoptosis, which can be prevented by CatB inhibition. Inhibition of the proapoptotic protein Bax prevents TRPML1 KD-mediated apoptosis but does not prevent cytosolic release of CatB. This is the first evidence of a mechanistic link between acute TRPML1 loss and cell death.

  17. Cleavage of desmin by cysteine proteases: Calpains and cathepsin B

    DEFF Research Database (Denmark)

    Baron, Caroline; Jacobsen, S.; Purslow, P.P.

    2004-01-01

    The intermediate filament protein, desmin, was purified from pork longissimus dorsi and incubated with either P-calpain, m-calpain or cathepsin B. Proteolysis of desmin was followed using SDS-PAGE and Western blotting. After incubation of desmin with the proteases, cleavage sites on the desmin...... a sequential C-terminal degradation pattern characteristic of this dipeptylpeptidase. The substrate primary structure was not found to be essential for regulation of the proteolytic activity of the cysteine peptidases studied. However, the degradation patterns obtained imply that calpains are involved...

  18. Reduction of mutant huntingtin accumulation and toxicity by lysosomal cathepsins D and B in neurons

    OpenAIRE

    Ouyang Xiaosen; Liang Qiuli; Schneider Lonnie; Zhang Jianhua

    2011-01-01

    Abstract Background Huntington's disease is caused by aggregation of mutant huntingtin (mHtt) protein containing more than a 36 polyQ repeat. Upregulation of macroautophagy was suggested as a neuroprotective strategy to degrade mutant huntingtin. However, macroautophagy initiation has been shown to be highly efficient in neurons whereas lysosomal activities are rate limiting. The role of the lysosomal and other proteases in Huntington is not clear. Some studies suggest that certain protease a...

  19. Cathepsins mediate tumor metastasis

    Institute of Scientific and Technical Information of China (English)

    Gong-Jun; Tan; Zheng-Ke; Peng; Jin-Ping; Lu; Fa-Qing; Tang

    2013-01-01

    Cathepsins are highly expressed in various human cancers, associated with tumor metastasis. It is superfamily, concluding A, B, C, D, E, F, G, H, L, K, O, S, V, and W family members. As a group of lysosomal proteinases or endopeptidases, each member has a different function, playing different roles in distinct tumorigenic processes such as proliferation, angiogenesis, metastasis, and invasion. Cathepsins belong to a diverse number of enzyme subtypes, including cysteine proteases, serine proteases and aspartic proteases. The contribution of cathepsins to invasion in human cancers is well documented, although the precise mechanisms by which cathepsins exert their effects are still not clear. In the present review, the role of cathepsin family members in cancer is discussed.

  20. Anthrax lethal toxin induced lysosomal membrane permeabilization and cytosolic cathepsin release is Nlrp1b/Nalp1b-dependent.

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    Kathleen M Averette

    Full Text Available NOD-like receptors (NLRs are a group of cytoplasmic molecules that recognize microbial invasion or 'danger signals'. Activation of NLRs can induce rapid caspase-1 dependent cell death termed pyroptosis, or a caspase-1 independent cell death termed pyronecrosis. Bacillus anthracis lethal toxin (LT, is recognized by a subset of alleles of the NLR protein Nlrp1b, resulting in pyroptotic cell death of macrophages and dendritic cells. Here we show that LT induces lysosomal membrane permeabilization (LMP. The presentation of LMP requires expression of an LT-responsive allele of Nlrp1b, and is blocked by proteasome inhibitors and heat shock, both of which prevent LT-mediated pyroptosis. Further the lysosomal protease cathepsin B is released into the cell cytosol and cathepsin inhibitors block LT-mediated cell death. These data reveal a role for lysosomal membrane permeabilization in the cellular response to bacterial pathogens and demonstrate a shared requirement for cytosolic relocalization of cathepsins in pyroptosis and pyronecrosis.

  1. Reduced cathepsins B and D cause impaired autophagic degradation that can be almost completely restored by overexpression of these two proteases in Sap C-deficient fibroblasts.

    Science.gov (United States)

    Tatti, Massimo; Motta, Marialetizia; Di Bartolomeo, Sabrina; Scarpa, Susanna; Cianfanelli, Valentina; Cecconi, Francesco; Salvioli, Rosa

    2012-12-01

    Saposin (Sap) C deficiency, a rare variant form of Gaucher disease, is due to mutations in the Sap C coding region of the prosaposin (PSAP) gene. Sap C is required as an activator of the lysosomal enzyme glucosylceramidase (GCase), which catalyzes glucosylceramide (GC) degradation. Deficit of either GCase or Sap C leads to the accumulation of undegraded GC and other lipids in lysosomes of monocyte/macrophage lineage. Recently, we reported that Sap C mutations affecting a cysteine residue result in increased autophagy. Here, we characterized the basis for the autophagic dysfunction. We analyzed Sap C-deficient and GCase-deficient fibroblasts and observed that autophagic disturbance was only associated with lack of Sap C. By a combined fluorescence microscopy and biochemical studies, we demonstrated that the accumulation of autophagosomes in Sap C-deficient fibroblasts is not due to enhanced autophagosome formation but to delayed degradation of autolysosomes caused, in part, to decreased amount and reduced enzymatic activity of cathepsins B and D. On the contrary, in GCase-deficient fibroblasts, the protein level and enzymatic activity of cathepsin D were comparable with control fibroblasts, whereas those of cathepsin B were almost doubled. Moreover, the enhanced expression of both these lysosomal proteases in Sap C-deficient fibroblasts resulted in close to functional autophagic degradation. Our data provide a novel example of altered autophagy as secondary event resulting from insufficient lysosomal function.

  2. Engineered nanomaterial-induced lysosomal membrane permeabilization and anti-cathepsin agents.

    Science.gov (United States)

    Bunderson-Schelvan, Melisa; Holian, Andrij; Hamilton, Raymond F

    2017-01-01

    Engineered nanomaterials (ENMs), or small anthropogenic particles approximately < 100 nm in size and of various shapes and compositions, are increasingly incorporated into commercial products and used for industrial and medical purposes. There is an exposure risk to both the population at large and individuals in the workplace with inhalation exposures to ENMs being a primary concern. Further, there is increasing evidence to suggest that certain ENMs may represent a significant health risk, and many of these ENMs exhibit distinct similarities with other particles and fibers that are known to induce adverse health effects, such as asbestos, silica, and particulate matter (PM). Evidence regarding the importance of lysosomal membrane permeabilization (LMP) and release of cathepsins in ENM toxicity has been accumulating. The aim of this review was to describe our current understanding of the mechanisms leading to ENM-associated pathologies, including LMP and the role of cathepsins with a focus on inflammation. In addition, anti-cathepsin agents, some of which have been tested in clinical trials and may prove useful for ameliorating the harmful effects of ENM exposure, are examined.

  3. Efficacy of Kefir on the Release of Lysosomal Proteases After Expremintal Spinal Cord Trauma

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    Emre Delen

    2015-11-01

    Full Text Available Aim: Prevention of secondary injury developing as a result of spinal cord injury will reduce significantly neurological deficits which may occur after trauma. These are focused in experimental studies and many agents are being tested. In our study, we have invesitigated the effects of kefir, which is a a probiotic, associated with life prolongation, whose antioxidant and lipid peroxidation effects were revealed on despite the scientific studies were limited, on lipid peroxidation and lysosomal proteases which play important roles in spinal cord. Material and Method: In the study, female Sprague Dawley rats weighing 200 to 250 g were used. The study was conducted on five groups with a total of 40 rats including the control, trauma, trauma treatment, trauma treatment kefir and trauma kefir groups. The high-dose methylprednisolone was used as the therapy. Spinal cord trauma was performed with clip compression method at the level of T10. Kefir was given to rats via orogastric ways, prior to trauma for 7 days at a dose of 2 * 1cc/100g. All rats were sacrificed 48 hours after treatment. The changes in the value of tissue cathepsins B and L, MDA and histopathological changes were examined. Results: It has been found in our study according to the review of biochemical values that; kefir did not reduce significantly cathepsin B values compared to the treatment group (p> 0.05, did reduce significantly MDA value compared to treatment group (p

  4. Sub-lethal oxidative stress induces lysosome biogenesis via a lysosomal membrane permeabilization-cathepsin-caspase 3-transcription factor EB-dependent pathway.

    Science.gov (United States)

    Leow, San Min; Chua, Shu Xian Serene; Venkatachalam, Gireedhar; Shen, Liang; Luo, Le; Clement, Marie-Veronique

    2016-12-18

    Here we provide evidence to link sub-lethal oxidative stress to lysosomal biogenesis. Exposure of cells to sub-lethal concentrations of exogenously added hydrogen peroxide resulted in cytosol to nuclear translocation of the Transcription Factor EB (TFEB), the master controller of lysosome biogenesis and function. Nuclear translocation of TFEB was dependent upon the activation of a cathepsin-caspase 3 signaling pathway, downstream of a lysosomal membrane permeabilization and accompanied by a significant increase in lysosome numbers as well as induction of TFEB dependent lysosome-associated genes expression such as Ctsl, Lamp2 and its spliced variant Lamp2a, Neu1and Ctsb and Sqstm1 and Atg9b. The effects of sub-lethal oxidative stress on lysosomal gene expression and biogenesis were rescued upon gene silencing of caspase 3 and TFEB. Notably, caspase 3 activation was not associated with phenotypic hallmarks of apoptosis, evidenced by the absence of caspase 3 substrate cleavage, such as PARP, Lamin A/C or gelsolin. Taken together, these data demonstrate for the first time an unexpected and non-canonical role of a cathepsin-caspase 3 axis in the nuclear translocation of TFEB leading to lysosomes biogenesis under conditions of sub-lethal oxidative stress.

  5. Cysteine proteases as therapeutic targets: does selectivity matter? A systematic review of calpain and cathepsin inhibitors.

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    Siklos, Marton; BenAissa, Manel; Thatcher, Gregory R J

    2015-11-01

    Cysteine proteases continue to provide validated targets for treatment of human diseases. In neurodegenerative disorders, multiple cysteine proteases provide targets for enzyme inhibitors, notably caspases, calpains, and cathepsins. The reactive, active-site cysteine provides specificity for many inhibitor designs over other families of proteases, such as aspartate and serine; however, a) inhibitor strategies often use covalent enzyme modification, and b) obtaining selectivity within families of cysteine proteases and their isozymes is problematic. This review provides a general update on strategies for cysteine protease inhibitor design and a focus on cathepsin B and calpain 1 as drug targets for neurodegenerative disorders; the latter focus providing an interesting query for the contemporary assumptions that irreversible, covalent protein modification and low selectivity are anathema to therapeutic safety and efficacy.

  6. Cysteine proteases as therapeutic targets: does selectivity matter? A systematic review of calpain and cathepsin inhibitors

    Directory of Open Access Journals (Sweden)

    Marton Siklos

    2015-11-01

    Full Text Available Cysteine proteases continue to provide validated targets for treatment of human diseases. In neurodegenerative disorders, multiple cysteine proteases provide targets for enzyme inhibitors, notably caspases, calpains, and cathepsins. The reactive, active-site cysteine provides specificity for many inhibitor designs over other families of proteases, such as aspartate and serine; however, a inhibitor strategies often use covalent enzyme modification, and b obtaining selectivity within families of cysteine proteases and their isozymes is problematic. This review provides a general update on strategies for cysteine protease inhibitor design and a focus on cathepsin B and calpain 1 as drug targets for neurodegenerative disorders; the latter focus providing an interesting query for the contemporary assumptions that irreversible, covalent protein modification and low selectivity are anathema to therapeutic safety and efficacy.

  7. Cathepsin F cysteine protease of the human liver fluke, Opisthorchis viverrini.

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    Porntip Pinlaor

    Full Text Available BACKGROUND: The liver fluke Opisthorchis viverrini is classified as a class I carcinogen due to the association between cholangiocarcinoma and chronic O. viverrini infection. During its feeding activity within the bile duct, the parasite secretes several cathepsin F cysteine proteases that may induce or contribute to the pathologies associated with hepatobiliary abnormalities. METHODOLOGY/PRINCIPAL FINDINGS: Here, we describe the cDNA, gene organization, phylogenetic relationships, immunolocalization, and functional characterization of the cathepsin F cysteine protease gene, here termed Ov-cf-1, from O. viverrini. The full length mRNA of 1020 nucleotides (nt encoded a 326 amino acid zymogen consisting of a predicted signal peptide (18 amino acids, aa, prosegment (95 aa, and mature protease (213 aa. BLAST analysis using the Ov-CF-1 protein as the query revealed that the protease shared identity with cathepsin F-like cysteine proteases of other trematodes, including Clonorchis sinensis (81%, Paragonimus westermani (58%, Schistosoma mansoni and S. japonicum (52%, and with vertebrate cathepsin F (51%. Transcripts encoding the protease were detected in all developmental stages that parasitize the mammalian host. The Ov-cf-1 gene, of approximately 3 kb in length, included seven exons interrupted by six introns; the exons ranged from 69 to 267 bp in length, the introns from 43 to 1,060 bp. The six intron/exon boundaries of Ov-cf-1 were conserved with intron/exon boundaries in the human cathepsin F gene, although the gene structure of human cathepsin F is more complex. Unlike Ov-CF-1, human cathepsin F zymogen includes a cystatin domain in the prosegment region. Phylogenetic analysis revealed that the fluke, human, and other cathepsin Fs branched together in a clade discrete from the cathepsin L cysteine proteases. A recombinant Ov-CF-1 zymogen that displayed low-level activity was expressed in the yeast Pichia pastoris. Although the recombinant

  8. The identification, characterization and optimization of small molecule probes of cysteine proteases: experiences of the Penn Center for Molecular Discovery with cathepsin B and cathepsin L.

    Science.gov (United States)

    Huryn, Donna M; Smith, Amos B

    2009-01-01

    During the pilot phase of the NIH Molecular Library Screening Network, the Penn Center for Molecular Discovery focused on a series of projects aimed at high throughput screening and the development of probes of a variety of protease targets. This review provides our medicinal chemistry experience with two such targets--cathepsin B and cathepsin L. We describe our approach for hit validation, characterization and triage that led to a critical understanding of the nature of hits from the cathepsin B project. In addition, we detail our experience at hit identification and optimization that led to the development of a novel thiocarbazate probe of cathepsin L.

  9. Isothiazolones; thiol-reactive inhibitors of cysteine protease cathepsin B and histone acetyltransferase PCAF

    NARCIS (Netherlands)

    Wisastra, Rosalina; Ghizzoni, Massimo; Maarsingh, Harm; Minnaard, Adriaan J.; Haisma, Hidde J.; Dekker, Frank J.

    2011-01-01

    Isothiazolones and 5-chloroisothiazolones react chemoselectively with thiols by cleavage of the weak nitrogen-sulfur bond to form disulfides. They show selectivity for inhibition of the thiol-dependent cysteine protease cathepsin B and the histone acetyltransferase p300/CBP associated factor (PCAF)

  10. Identification of a novel Fasciola hepatica cathepsin L protease containing protective epitopes within the propeptide

    NARCIS (Netherlands)

    Harmsen, M.M.; Cornelissen, J.B.W.J.; Buys-Bergen, W.E.C.M.; Boersma, W.J.A.; Jeurissen, S.H.M.; Milligen, F.J.

    2004-01-01

    Cathepsin L (CL)-like proteases are important candidate vaccine antigens for protection against helminth infections. We previously identified an immunogenic 32 kDa protein specifically present in newly excysted juveniles (NEJs) of Fasciola hepatica. Here we show by N-terminal protein sequencing that

  11. HIV Protease Inhibitor-Induced Cathepsin Modulation Alters Antigen Processing and Cross-Presentation.

    Science.gov (United States)

    Kourjian, Georgio; Rucevic, Marijana; Berberich, Matthew J; Dinter, Jens; Wambua, Daniel; Boucau, Julie; Le Gall, Sylvie

    2016-05-01

    Immune recognition by T cells relies on the presentation of pathogen-derived peptides by infected cells, but the persistence of chronic infections calls for new approaches to modulate immune recognition. Ag cross-presentation, the process by which pathogen Ags are internalized, degraded, and presented by MHC class I, is crucial to prime CD8 T cell responses. The original degradation of Ags is performed by pH-dependent endolysosomal cathepsins. In this article, we show that HIV protease inhibitors (PIs) prescribed to HIV-infected persons variably modulate cathepsin activities in human APCs, dendritic cells and macrophages, and CD4 T cells, three cell subsets infected by HIV. Two HIV PIs acted in two complementary ways on cathepsin hydrolytic activities: directly on cathepsins and indirectly on their regulators by inhibiting Akt kinase activities, reducing NADPH oxidase 2 activation, and lowering phagolysosomal reactive oxygen species production and pH, which led to enhanced cathepsin activities. HIV PIs modified endolysosomal degradation and epitope production of proteins from HIV and other pathogens in a sequence-dependent manner. They altered cross-presentation of Ags by dendritic cells to epitope-specific T cells and T cell-mediated killing. HIV PI-induced modulation of Ag processing partly changed the MHC self-peptidome displayed by primary human cells. This first identification, to our knowledge, of prescription drugs modifying the regulation of cathepsin activities and the MHC-peptidome may provide an alternate therapeutic approach to modulate immune recognition in immune disease beyond HIV.

  12. Toxoplasma gondii cathepsin proteases are undeveloped prominent vaccine antigens against toxoplasmosis

    OpenAIRE

    Zhao, Guanghui; Zhou, Aihua; Lv, Gang; Meng, Min; Sun, Min; Bai, Yang; Han, Yali; Wang, Lin; Zhou, Huaiyu; Cong, Hua; Zhao, Qunli; Zhu, Xing-Quan; He, Shenyi

    2013-01-01

    Background Toxoplasma gondii, an obligate intracellular apicomplexan parasite, infects a wide range of warm-blooded animals including humans. T. gondii expresses five members of the C1 family of cysteine proteases, including cathepsin B-like (TgCPB) and cathepsin L-like (TgCPL) proteins. TgCPB is involved in ROP protein maturation and parasite invasion, whereas TgCPL contributes to proteolytic maturation of proTgM2AP and proTgMIC3. TgCPL is also associated with the residual body in the parasi...

  13. Cathepsin G, a Neutrophil Protease, Induces Compact Cell-Cell Adhesion in MCF-7 Human Breast Cancer Cells

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    Tomoya Kudo

    2009-01-01

    Full Text Available Cathepsin G is a serine protease secreted by activated neutrophils that play a role in the inflammatory response. Because neutrophils are known to be invading leukocytes in various tumors, their products may influence the characteristics of tumor cells such as the growth state, motility, and the adhesiveness between cells or the extracellular matrix. Here, we demonstrate that cathepsin G induces cell-cell adhesion of MCF-7 human breast cancer cells resulting from the contact inhibition of cell movement on fibronectin but not on type IV collagen. Cathepsin G subsequently induced cell condensation, a very compact cell colony, resulting due to the increased strength of E-cadherin-mediated cell-cell adhesion. Cathepsin G action is protease activity-dependent and was inhibited by the presence of serine protease inhibitors. Cathepsin G promotes E-cadherin/catenin complex formation and Rap1 activation in MCF-7 cells, which reportedly regulates E-cadherin-based cell-cell junctions. Cathepsin G also promotes E-cadherin/protein kinase D1 (PKD1 complex formation, and Go6976, the selective PKD1 inhibitor, suppressed the cathepsin G-induced cell condensation. Our findings provide the first evidence that cathepsin G regulates E-cadherin function, suggesting that cathepsin G has a novel modulatory role against tumor cell-cell adhesion.

  14. Salivary Tick Cystatin OmC2 Targets Lysosomal Cathepsins S and C in Human Dendritic Cells

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    Tina Zavašnik-Bergant

    2017-06-01

    Full Text Available To ensure successful feeding tick saliva contains a number of inhibitory proteins that interfere with the host immune response and help to create a permissive environment for pathogen transmission. Among the potential targets of the salivary cystatins are two host cysteine proteases, cathepsin S, which is essential for antigen- and invariant chain-processing, and cathepsin C (dipeptidyl peptidase 1, DPP1, which plays a critical role in processing and activation of the granule serine proteases. Here, the effect of salivary cystatin OmC2 from Ornithodoros moubata was studied using differentiated MUTZ-3 cells as a model of immature dendritic cells of the host skin. Following internalization, cystatin OmC2 was initially found to inhibit the activity of several cysteine cathepsins, as indicated by the decreased rates of degradation of fluorogenic peptide substrates. To identify targets, affinity chromatography was used to isolate His-tagged cystatin OmC2 together with the bound proteins from MUTZ-3 cells. Cathepsins S and C were identified in these complexes by mass spectrometry and confirmed by immunoblotting. Furthermore, reduced increase in the surface expression of MHC II and CD86, which are associated with the maturation of dendritic cells, was observed. In contrast, human inhibitor cystatin C, which is normally expressed and secreted by dendritic cells, did not affect the expression of CD86. It is proposed that internalization of salivary cystatin OmC2 by the host dendritic cells targets cathepsins S and C, thereby affecting their maturation.

  15. Lysosomal cell death at a glance

    DEFF Research Database (Denmark)

    Aits, Sonja; Jaattela, Marja

    2013-01-01

    Lysosomes serve as the cellular recycling centre and are filled with numerous hydrolases that can degrade most cellular macromolecules. Lysosomal membrane permeabilization and the consequent leakage of the lysosomal content into the cytosol leads to so-called "lysosomal cell death". This form...... of cell death is mainly carried out by the lysosomal cathepsin proteases and can have necrotic, apoptotic or apoptosis-like features depending on the extent of the leakage and the cellular context. This article summarizes our current knowledge on lysosomal cell death with an emphasis on the upstream...... mechanisms that lead to lysosomal membrane permeabilization....

  16. xtraction and Characterization of Cathepsin Inhibitor from Milkfish

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    Tati Nurhayati

    2015-06-01

    Full Text Available Abstract Proteolytic enzyme is distributed acros all organism including fish. Cysteine proteases are the largest group of proteolytic enzyme. Lysosomal cathepsin, one of cysteine protease enzyme, cause softening and degradation of myofibril protein and it’s activity is regulated by endogenous inhibitors. The purposes of this study were to optimize the extraction cathepsin inhibitors from the skin, muscles, and viscera of fish, to partially purify the cathepsin inhibitors of selected sources, and to study the characteristics of the cathepsin inhibitor. The cathepsin inhibitor could be extracted from muscle fish and partially purified using ammonium sulfate of 70%. The purified cathepsin inhibitor had optimum temperature at 40°C and the optimum at pH 8. Metal ions decreased the activity of the protease inhibitor, except 1 mM of metal ion Mn2+ and Na+.

  17. Active subsite properties, subsite residues and targeting to lysosomes or midgut lumen of cathepsins L from the beetle Tenebrio molitor.

    Science.gov (United States)

    Damasceno, Ticiane F; Dias, Renata O; de Oliveira, Juliana R; Salinas, Roberto K; Juliano, Maria A; Ferreira, Clelia; Terra, Walter R

    2017-08-25

    Cathepsins L are the major digestive peptidases in the beetle Tenebrio molitor. Two digestive cathepsins L (TmCAL2 and TmCAL3) from it had their 3D structures solved. The aim of this paper was to study in details TmCAL3 specificity and properties and relate them to its 3D structure. Recombinant TmCAL3 was assayed with 64 oligopeptides with different amino acid replacements in positions P2, P1, P1' and P2'. Results showed that TmCAL3 S2 specificity differs from the human enzyme and that its specificities also explain why on autoactivation two propeptide residues remain in the enzyme. Data on free energy of binding and of activation showed that S1 and S2' are mainly involved in substrate binding, S1' acts in substrate binding and catalysis, whereas S2 is implied mainly in catalysis. Enzyme subsite residues were identified by docking with the same oligopeptide used for kinetics. The subsite hydrophobicities were calculated from the efficiency of hydrolysis of different amino acid replacements in the peptide and from docking data. The results were closer for S1 and S2' than for S1' and S2, indicating that the residue subsites that were more involved in transition state binding are different from those binding the substrate seen in docking. Besides TmCAL1-3, there are nine other cathepsins L, most of them more expressed at midgut. They are supposed to be directed to lysosomes by a Drosophila-like Lerp receptor and/or motifs in their prodomains. The mannose 6-phosphate lysosomal sorting machinery is absent from T. molitor transcriptome. Cathepsin L direction to midgut contents seems to depend on overexpression. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Odanacatib, a Cathepsin K Cysteine Protease Inhibitor, Kills Hookworm In Vivo

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    Jon J. Vermeire

    2016-07-01

    Full Text Available Hookworm infection is chief among soil-transmitted helminthiases (STHs for the chronic morbidly inflicted. Deworming via mass drug administration (MDA programs most often employs single doses of benzimidazole drugs to which resistance is a constant threat. To discover new drugs, we employ a hamster model of hookworm infection with Ancylostoma ceylanicum and use albendazole (ABZ; 10 mg/kg orally as the gold standard therapy. We previously showed that a single oral 100 mg/kg dose of the cathepsin cysteine protease (CP inhibitor, K11777, offers near cure of infection that is associated with a 95% reduction in the parasite’s resident CP activity. We confirm these findings here and demonstrate that odanacatib (ODN, Merck’s cathepsin K inhibitor and post-clinical Phase III drug candidate for treatment of osteoporosis, decreases worm burden by 73% at the same dose with a 51% reduction in the parasite’s CP activity. Unlike K11777, ODN is a modest inhibitor of both mammalian cathepsin B and the predominant cathepsin B-like activity measureable in hookworm extracts. ODN’s somewhat unexpected efficacy, therefore, may be due to its excellent pharmacokinetic (PK profile which allows for sustained plasma exposure and, possibly, sufficient perturbation of hookworm cathepsin B activity to be detrimental to survival. Accordingly, identifying a CP inhibitor(s that combines the inhibition potency of K11777 and the PK attributes of ODN could lead to a drug that is effective at a lower dose. Achieving this would potentially provide an alternative or back-up to the current anti-hookworm drug, albendazole.

  19. Cloning and characterization of a cathepsin L-like cysteine protease from Taenia pisiformis.

    Science.gov (United States)

    Wang, Qiuxia; Zhang, Shaohua; Luo, Xuenong; Hou, Junling; Zhu, Xueliang; Cai, Xuepeng

    2013-05-01

    Rabbit cysticercosis, caused by the larval stage of Taenia pisiformis, is a serious parasitic disease of rabbits. It was reported that some cysteine peptidases have potential roles in the pathogenesis of various parasitic infections. To investigate the biochemical characteristics and roles in the pathogenesis/host-invasion of cysteine peptidases, a cDNA sequence encoding for a cathepsin L-like cysteine protease (TpCP) was cloned and identified from the T. pisiformis metacestodes. This sequence was 1220 bp in its length, which included a 1017 bp open reading frame encoding a 339 amino acid peptide. Multiple sequence alignments revealed a 28.9-88.5% similarity with cathepsin L-like cysteine proteases from other helminth parasites and mammals. The recombinant TpCP expressed in Escherichia coli did not show the proteolytic activity by zymography gel assay. However, the TpCP expressed in Pichia pastoris had typical biochemical activities that could hydrolyze rabbit immunoglobulin G, bovine serum albumin and fibronectin. Substrate studies indicated pronounced cleavage of Z-Phe-Arg-AMC. This activity was sensitive to cysteine protease inhibitor E-64 and immunohistochemistry results also indicated that TpCP was distributed as an intense positive reaction in the bladder wall. Our results gave us insights into future studies of TpCP's roles in the infection.

  20. On Blastocystis secreted cysteine proteases: a legumain-activated cathepsin B increases paracellular permeability of intestinal Caco-2 cell monolayers.

    Science.gov (United States)

    Nourrisson, C; Wawrzyniak, I; Cian, A; Livrelli, V; Viscogliosi, E; Delbac, F; Poirier, P

    2016-11-01

    Blastocystis spp. pathogenic potential remains unclear as these anaerobic parasitic protozoa are frequently isolated from stools of both symptomatic and asymptomatic subjects. In silico analysis of the whole genome sequence of Blastocystis subtype 7 revealed the presence of numerous proteolytic enzymes including cysteine proteases predicted to be secreted. To assess the potential impact of proteases on intestinal cells and gut function, we focused our study on two cysteine proteases, a legumain and a cathepsin B, which were previously identified in Blastocystis subtype 7 culture supernatants. Both cysteine proteases were produced as active recombinant proteins. Activation of the recombinant legumain was shown to be autocatalytic and triggered by acidic pH, whereas proteolytic activity of the recombinant cathepsin B was only recorded after co-incubation with the legumain. We then measured the diffusion of 4-kDa FITC-labelled dextran across Caco-2 cell monolayers following exposition to either Blastocystis culture supernatants or each recombinant protease. Both Blastocystis culture supernatants and recombinant activated cathepsin B induced an increase of Caco-2 cell monolayer permeability, and this effect was significantly inhibited by E-64, a specific cysteine protease inhibitor. Our results suggest that cathepsin B might play a role in pathogenesis of Blastocystis by increasing intestinal cell permeability.

  1. Eimeripain, a cathepsin B-like cysteine protease, expressed throughout sporulation of the apicomplexan parasite Eimeria tenella.

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    Anaïs Rieux

    Full Text Available The invasion and replication of Eimeria tenella in the chicken intestine is responsible for avian coccidiosis, a disease that has major economic impacts on poultry industries worldwide. E. tenella is transmitted to naïve animals via shed unsporulated oocysts that need contact with air and humidity to form the infectious sporulated oocysts, which contain the first invasive form of the parasite, the sporozoite. Cysteine proteases (CPs are major virulence factors expressed by protozoa. In this study, we show that E. tenella expresses five transcriptionally regulated genes encoding one cathepsin L, one cathepsin B and three cathepsin Cs. Biot-LC-LVG-CHN₂, a cystatin derived probe, tagged eight polypeptides in unsporulated oocysts but only one in sporulated oocysts. CP-dependant activities were found against the fluorescent substrates, Z-FR-AMC and Z-LR-AMC, throughout the sporulation process. These activities corresponded to a cathepsin B-like enzyme since they were inhibited by CA-074, a specific cathepsin B inhibitor. A 3D model of the catalytic domain of the cathepsin B-like protease, based on its sequence homology with human cathepsin B, further confirmed its classification as a papain-like protease with similar characteristics to toxopain-1 from the related apicomplexan parasite, Toxoplasma gondii; we have, therefore, named the E. tenella cathepsin B, eimeripain. Following stable transfection of E. tenella sporozoites with a plasmid allowing the expression of eimeripain fused to the fluorescent protein mCherry, we demonstrated that eimeripain is detected throughout sporulation and has a punctate distribution in the bodies of extra- and intracellular parasites. Furthermore, CA-074 Me, the membrane-permeable derivative of CA-074, impairs invasion of epithelial MDBK cells by E. tenella sporozoites. This study represents the first characterization of CPs expressed by a parasite from the Eimeria genus. Moreover, it emphasizes the role of CPs in

  2. Serum cathepsin H as a potential prognostic marker in patients with colorectal cancer

    DEFF Research Database (Denmark)

    Schweiger, A; Christensen, Ib Jarle; Nielsen, Hans Jørgen

    2005-01-01

    Cathepsin H is a lysosomal cysteine protease that may participate in tumor progression. In order to evaluate its potential as a prognostic marker, its protein levels were measured by ELISA in preoperative sera from 324 patients with colorectal cancer. The level of cathepsin H was significantly...

  3. Molecular characterization of a cathepsin F-like protease in Trichinella spiralis.

    Science.gov (United States)

    Qu, Zi-gang; Ma, Xue-ting; Li, Wen-hui; Zhang, Nian-zhang; Yue, Long; Cui, Jian-min; Cai, Jian-ping; Jia, Wan-zhong; Fu, Bao-quan

    2015-12-21

    Trichinellosis is a re-emerging infectious disease, caused by Trichinella spp. Cathepsin F belongs to cysteine protease that is a major virulence factor for parasitic helminths, and it may be a potential anti-helminth drug target and vaccine candidate. The aim of this study was to clone, express and identify a cathepsin F-like protease in Trichinella spiralis and to investigate its biochemical characteristics. The full-length cDNA encoding a putative cathepsin F-like protease in T. spiralis, TsCF1, was cloned and its biochemical characterization and expression profile were analyzed. Transcription of TsCF1 at different developmental stages of T. spiralis was observed by RT-PCR. The recombinant TsCF1 protein was expressed by prokaryotic expression system and recombinant TsCF1 (rTsCF1) was analyzed by western blotting. And expression of TsCF1 at muscle larvae stage was performed by immunofluorescent technique. Molecular modeling of TsCF1 and its binding mode with E-64 and K11777 were analyzed. Enzyme activity and inhibitory test with E-64 as inhibitor were investigated by using Z-Phe-Arg-AMC as specific substrate. Sequence analysis revealed that TsCF1 ORF encodes a protein of 366 aa with a theoretical molecular weight of 41.9 kDa and an isoelectric point of 7.46. The cysteine protease conserved active site of Cys173, His309 and Asn333 were identified and cathepsin F specific motif ERFNAQ like KLFNAQ sequence was revealed in the propeptide of TsCF1. Sequence alignment analysis revealed a higher than 40 % identity with other cathepsin F from parasitic helminth and phylogenetic analysis indicated TsCF1 located at the junction of nematode and trematode. RT-PCR revealed the gene was expressed in muscle larvae, newborn larvae and adult stages. SDS-PAGE revealed the recombinant protein was expressed with the molecular weight of 45 kDa. The purified rTsCF1 was used to immunize rabbit and the immune serum could recognize a band of about 46 kDa in soluble protein of adult

  4. Expression Pattern of Lysosomal Protective Protein/Cathepsin A: Implications for the analysis of hnman galactosialidosis

    NARCIS (Netherlands)

    R.J. Rottier (Robbert)

    1998-01-01

    textabstractThe lysosome represents a well characterized, membrane-contained intracellular digestive system. Iu this important organelle a battery of lysosomal hydro lases and accessory proteins work in concert on the step-wise conversion of macromolecular substrates into small biological building b

  5. Neutrophil Cathepsin G, but Not Elastase, Induces Aggregation of MCF-7 Mammary Carcinoma Cells by a Protease Activity-Dependent Cell-Oriented Mechanism

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    Satoru Yui

    2014-01-01

    Full Text Available We previously found that a neutrophil serine protease, cathepsin G, weakens adherence to culture substrates and induces E-cadherin-dependent aggregation of MCF-7 human breast cancer cells through its protease activity. In this study, we examined whether aggregation is caused by degradation of adhesion molecules on the culture substrates or through an unidentified mechanism. We compared the effect of treatment with cathepsin G and other proteases, including neutrophil elastase against fibronectin- (FN- coated substrates. Cathepsin G and elastase potently degraded FN on the substrates and induced aggregation of MCF-7 cells that had been subsequently seeded onto the substrate. However, substrate-bound cathepsin G and elastase may have caused cell aggregation. After inhibiting the proteases on the culture substrates using the irreversible inhibitor phenylmethylsulfonyl fluoride (PMSF, we examined whether aggregation of MCF-7 cells was suppressed. PMSF attenuated cell aggregation on cathepsin G-treated substrates, but the effect was weak in cells pretreated with high concentrations of cathepsin G. In contrast, PMSF did not suppress cell aggregation on elastase-treated FN. Moreover, cathepsin G, but not elastase, induced aggregation on poly-L-lysine substrates which are not decomposed by these enzymes, and the action of cathepsin G was nearly completely attenuated by PMSF. These results suggest that cathepsin G induces MCF-7 aggregation through a cell-oriented mechanism.

  6. Novel cathepsin B and cathepsin B-like cysteine protease of Naegleria fowleri excretory-secretory proteins and their biochemical properties.

    Science.gov (United States)

    Lee, Jinyoung; Kim, Jong-Hyun; Sohn, Hae-Jin; Yang, Hee-Jong; Na, Byoung-Kuk; Chwae, Yong-Joon; Park, Sun; Kim, Kyongmin; Shin, Ho-Joon

    2014-08-01

    Naegleria fowleri causes a lethal primary amoebic meningoencephalitis (PAM) in humans and experimental animals, which leads to death within 7-14 days. Cysteine proteases of parasites play key roles in nutrient uptake, excystment/encystment, host tissue invasion, and immune evasion. In this study, we cloned N. fowleri cathepsin B (nfcpb) and cathepsin B-like (nfcpb-L) genes from our cDNA library of N. fowleri. The full-length sequences of genes were 1,038 and 939 bp (encoded 345 and 313 amino acids), and molecular weights were 38.4 and 34 kDa, respectively. Also, nfcpb and nfcpb-L showed a 56 and 46 % identity to Naegleria gruberi cathepsin B and cathepsin B-like enzyme, respectively. Recombinant NfCPB (rNfCPB) and NfCPB-L (rNfCPB-L) proteins were expressed by the pEX5-NT/TOPO vector that was transformed into Escherichia coli BL21, and they showed 38.4 and 34 kDa bands on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analysis using their respective antibodies. Proteolytic activity of refolded rNfCPB and rNfCPB-L was maximum at a pH of 4.5, and the most effective substrate was Z-LR-MCA. rNfCPB and rNfCPB-L showed proteolytic activity for several proteins such as IgA, IgG, IgM, collagen, fibronectin, hemoglobin, and albumin. These results suggested that NfCPB and NfCPB-L cysteine protease are important components of the N. fowleri ESP, and they may play important roles in host tissue invasion and immune evasion as pathogens that cause N. fowleri PAM.

  7. The role of lysosomal cysteine proteases in crustacean immune response

    Directory of Open Access Journals (Sweden)

    FL Garcia-Carreño

    2014-04-01

    Full Text Available Over the long course of evolution and under the selective pressure exerted by pathogens and parasites, animals have selectively fixed a number of defense mechanisms against the constant attack of intruders. The immune response represents a key component to optimize the biological fitness of individuals. Two decades ago, prevention and control of diseases in crustacean aquaculture systems were considered priorities in most shrimp-producing countries, but knowledge was scarce and various pathogens have severely affected aquaculture development around the world. Scientific contributions have improved our understanding of the crustacean immune response. Several studies confirm the central role played by proteases in the immune response of animals, and the cooperative interaction of these enzymes in a wide variety of organisms is well known. This review summarizes the current information regarding the role of cysteine proteases in the immune system of Crustacea and points to aspects that are needed to provide a better integration of our knowledge.

  8. Cathepsin S Cleavage of Protease-Activated Receptor-2 on Endothelial Cells Promotes Microvascular Diabetes Complications.

    Science.gov (United States)

    Kumar Vr, Santhosh; Darisipudi, Murthy N; Steiger, Stefanie; Devarapu, Satish Kumar; Tato, Maia; Kukarni, Onkar P; Mulay, Shrikant R; Thomasova, Dana; Popper, Bastian; Demleitner, Jana; Zuchtriegel, Gabriele; Reichel, Christoph; Cohen, Clemens D; Lindenmeyer, Maja T; Liapis, Helen; Moll, Solange; Reid, Emma; Stitt, Alan W; Schott, Brigitte; Gruner, Sabine; Haap, Wolfgang; Ebeling, Martin; Hartmann, Guido; Anders, Hans-Joachim

    2016-06-01

    Endothelial dysfunction is a central pathomechanism in diabetes-associated complications. We hypothesized a pathogenic role in this dysfunction of cathepsin S (Cat-S), a cysteine protease that degrades elastic fibers and activates the protease-activated receptor-2 (PAR2) on endothelial cells. We found that injection of mice with recombinant Cat-S induced albuminuria and glomerular endothelial cell injury in a PAR2-dependent manner. In vivo microscopy confirmed a role for intrinsic Cat-S/PAR2 in ischemia-induced microvascular permeability. In vitro transcriptome analysis and experiments using siRNA or specific Cat-S and PAR2 antagonists revealed that Cat-S specifically impaired the integrity and barrier function of glomerular endothelial cells selectively through PAR2. In human and mouse type 2 diabetic nephropathy, only CD68(+) intrarenal monocytes expressed Cat-S mRNA, whereas Cat-S protein was present along endothelial cells and inside proximal tubular epithelial cells also. In contrast, the cysteine protease inhibitor cystatin C was expressed only in tubules. Delayed treatment of type 2 diabetic db/db mice with Cat-S or PAR2 inhibitors attenuated albuminuria and glomerulosclerosis (indicators of diabetic nephropathy) and attenuated albumin leakage into the retina and other structural markers of diabetic retinopathy. These data identify Cat-S as a monocyte/macrophage-derived circulating PAR2 agonist and mediator of endothelial dysfunction-related microvascular diabetes complications. Thus, Cat-S or PAR2 inhibition might be a novel strategy to prevent microvascular disease in diabetes and other diseases.

  9. Structural and Functional Relationships in the Virulence-associated Cathepsin L Proteases of the Parasitic Liver Fluke, Fasciola hepatica*

    Science.gov (United States)

    Stack, Colin M.; Caffrey, Conor R.; Donnelly, Sheila M.; Seshaadri, Amritha; Lowther, Jonathan; Tort, Jose F.; Collins, Peter R.; Robinson, Mark W.; Xu, Weibo; McKerrow, James H.; Craik, Charles S.; Geiger, Sebastian R.; Marion, Rachel; Brinen, Linda S.; Dalton, John P.

    2008-01-01

    The helminth parasite Fasciola hepatica secretes cysteine proteases to facilitate tissue invasion, migration, and development within the mammalian host. The major proteases cathepsin L1 (FheCL1) and cathepsin L2 (FheCL2) were recombinantly produced and biochemically characterized. By using site-directed mutagenesis, we show that residues at position 67 and 205, which lie within the S2 pocket of the active site, are critical in determining the substrate and inhibitor specificity. FheCL1 exhibits a broader specificity and a higher substrate turnover rate compared with FheCL2. However, FheCL2 can efficiently cleave substrates with a Pro in the P2 position and degrade collagen within the triple helices at physiological pH, an activity that among cysteine proteases has only been reported for human cathepsin K. The 1.4-Å three-dimensional structure of the FheCL1 was determined by x-ray crystallography, and the three-dimensional structure of FheCL2 was constructed via homology-based modeling. Analysis and comparison of these structures and our biochemical data with those of human cathepsins L and K provided an interpretation of the substrate-recognition mechanisms of these major parasite proteases. Furthermore, our studies suggest that a configuration involving residue 67 and the “gatekeeper” residues 157 and 158 situated at the entrance of the active site pocket create a topology that endows FheCL2 with its unusual collagenolytic activity. The emergence of a specialized collagenolytic function in Fasciola likely contributes to the success of this tissue-invasive parasite. PMID:18160404

  10. A specific cathepsin-L-like protease purified from an insect midgut shows antibacterial activity against gut symbiotic bacteria.

    Science.gov (United States)

    Byeon, Jin Hee; Seo, Eun Sil; Lee, Jun Beom; Lee, Min Ja; Kim, Jiyeun Kate; Yoo, Jin Wook; Jung, Yunjin; Lee, Bok Luel

    2015-11-01

    Because gut symbiotic bacteria affect host biology, host insects are expected to evolve some mechanisms for regulating symbiont population. The bean bug, Riptortus pedestris, harbors the Burkholderia genus as a gut symbiont in the midgut organ, designated as the M4 region. Recently, we demonstrated that the lysate of M4B, the region adjacent to M4, harbors potent antibacterial activity against symbiotic Burkholderia but not to cultured Burkholderia. However, the bona fide substance responsible for observed antibacterial activity was not identified in the previous study. Here, we report that cathepsin-L-like protease purified from the lysate of M4B showed strong antibacterial activity against symbiotic Burkholderia but not the cultured Burkholderia. To further confirm this activity, recombinant cathepsin-L-like protease expressed in Escherichia coli also showed antibacterial activity against symbiotic Burkholderia. These results suggest that cathepsin-L-like protease purified from the M4B region plays a critical role in controlling the population of the Burkholderia gut symbiont. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Cathepsin X in serum from patients with colorectal cancer

    DEFF Research Database (Denmark)

    Vizin, Tjasa; Christensen, Ib Jarle; Nielsen, Hans Jørgen

    2012-01-01

    Up-regulation of lysosomal cysteine protease cathepsin X (Cat X) is associated with disorders of the immune system and neurodegenerative diseases, while its role in the development and progression of cancer is less understood. Enhanced secretion of pro-Cat X was observed in malignant processes...

  12. Evolutionary History of Cathepsin L (L-like) Family Genes in Vertebrates.

    Science.gov (United States)

    Zhou, Jin; Zhang, Yao-Yang; Li, Qing-Yun; Cai, Zhong-Hua

    2015-01-01

    Cathepsin L family, an important cysteine protease found in lysosomes, is categorized into cathepsins B, F, H, K, L, S, and W in vertebrates. This categorization is based on their sequence alignment and traditional functional classification, but the evolutionary relationship of family members is unclear. This study determined the evolutionary relationship of cathepsin L family genes in vertebrates through phylogenetic construction. Results showed that cathepsins F, H, S and K, and L and V were chronologically diverged. Tandem-repeat duplication was found to occur in the evolutionary history of cathepsin L family. Cathepsin L in zebrafish, cathepsins S and K in xenopus, and cathepsin L in mice and rats underwent evident tandem-repeat events. Positive selection was detected in cathepsin L-like members in mice and rats, and amino acid sites under positive selection pressure were calculated. Most of these sites appeared at the connection of secondary structures, suggesting that the sites may slightly change spatial structure. Severe positive selection was also observed in cathepsin V (L2) of primates, indicating that this enzyme had some special functions. Our work provided a brief evolutionary history of cathepsin L family and differentiated cathepsins S and K from cathepsin L based on vertebrate appearance. Positive selection was the specific cause of differentiation of cathepsin L family genes, confirming that gene function variation after expansion events was related to interactions with the environment and adaptability.

  13. Internalization of exogenous cystatin F supresses cysteine proteases and induces the accumulation of single-chain cathepsin L by multiple mechanisms.

    Science.gov (United States)

    Colbert, Jeff D; Matthews, Stephen P; Kos, Janko; Watts, Colin

    2011-12-01

    Cystatin F is an unusual member of the cystatin family of protease inhibitors, which is made as an inactive dimer and becomes activated by proteolysis in the endo/lysosome pathway of the immune cells that produce it. However a proportion is secreted and can be taken up and activated by other cells. We show here that cystatin F acquired in this way induces a dramatic accumulation of the single-chain form of cathepsin L (CatL). Cystatin F was observed in the same cellular compartments as CatL and was tightly complexed with CatL as determined by co-precipitation studies. The observed accumulation of single-chain CatL was partly due to cystatin F-mediated inhibition of the putative single-chain to two-chain CatL convertase AEP/legumain and partly to general suppression of cathepsin activity. Thus, cystatin F stabilizes CatL leading to the dramatic accumulation of an inactive complex composed either of the single-chain or two-chain form depending on the capacity of cystatin F to inhibit AEP. Cross-transfer of cystatin F from one cell to another may therefore attenuate potentially harmful effects of excessive CatL activity while paradoxically, inducing accumulation of CatL protein. Finally, we confirmed earlier data (Beers, C., Honey, K., Fink, S., Forbush, K., and Rudensky, A. (2003) J. Exp. Med. 197, 169-179) showing a loss of CatL activity, but not of CatL protein, in macrophages activated with IFNγ. However, we found equivalent loss of CatL activity in wild type and cystatin F-null macrophages suggesting that an inhibitory activity other than cystatin F quenches CatL activity in activated macrophages.

  14. The crystal structure of human dipeptidyl peptidase I (cathepsin C) in complex with the inhibitor Gly-Phe-CHN2

    DEFF Research Database (Denmark)

    Mølgaard, Anne; Arnau, Jose; Lauritzen, C.

    2007-01-01

    hDDPI (human dipeptidyl peptidase I) is a lysosomal cysteine protease involved in zymogen activation of granule-associated proteases, including granzymes A and B from cytotoxic T-lymphocytes and natural killer cells, cathepsin G and neutrophil elastase, and mast cell tryptase and chymase...

  15. Lysosome

    Directory of Open Access Journals (Sweden)

    Ursula Matte BSc, PhD

    2016-12-01

    Full Text Available Since Christian de Duve first described the lysosome in the 1950s, it has been generally presented as a membrane-bound compartment containing acid hydrolases that enables the cell to degrade molecules without being digested by autolysis. For those working on the field of lysosomal storage disorders, the lack of one such hydrolase would lead to undegraded or partially degraded substrate storage inside engorged organelles disturbing cellular function by yet poorly explored mechanisms. However, in recent years, a much more complex scenario of lysosomal function has emerged, beyond and above the cellular “digestive” system. Knowledge on how the impairment of this organelle affects cell functioning may shed light on signs and symptoms of lysosomal disorders and open new roads for therapy.

  16. Lysosome

    National Research Council Canada - National Science Library

    Ursula Matte BSc, PhD; Gabriela Pasqualim BSc, MSc

    2016-01-01

    Since Christian de Duve first described the lysosome in the 1950s, it has been generally presented as a membrane-bound compartment containing acid hydrolases that enables the cell to degrade molecules...

  17. Exploration of peptides that fit into the thermally vibrating active site of cathepsin K protease by alternating artificial intelligence and molecular simulation

    Science.gov (United States)

    Nishiyama, Katsuhiko

    2017-08-01

    Eighteen tripeptides that fit into the thermally vibrating active site of cathepsin K were discovered by alternating artificial intelligence and molecular simulation. The 18 tripeptides fit the active site better than the cysteine protease inhibitor E64, and a better inhibitor of cathepsin K could be designed considering these tripeptides. Among the 18 tripeptides, Phe-Arg-Asp and Tyr-Arg-Asp fit the active site the best and their structural similarity should be considered in the design process. Interesting factors emerged from the structure of the decision tree, and its structural information will guide exploration of potential inhibitor molecules for proteases.

  18. Hippocampal neurons exposed to the environmental contaminants methylmercury and polychlorinated biphenyls undergo cell death via parallel activation of calpains and lysosomal proteases.

    Science.gov (United States)

    Tofighi, Roshan; Johansson, Carolina; Goldoni, Matteo; Ibrahim, Wan Norhamidah Wan; Gogvadze, Vladimir; Mutti, Antonio; Ceccatelli, Sandra

    2011-01-01

    Methylmercury (MeHg) and polychlorinated biphenyls (PCBs) are widespread environmental pollutants commonly found as contaminants in the same food sources. Even though their neurotoxic effects are established, the mechanisms of action are not fully understood. In the present study, we have used the mouse hippocampal neuronal cell line HT22 to investigate the mechanisms of neuronal death induced by MeHg, PCB 153, and PCB 126, alone or in combination. All chemicals induced cell death with morphological changes compatible with either apoptosis or necrosis. Mitochondrial functions were impaired as shown by the significant decrease in mitochondrial Ca²+ uptake capacity and ATP levels. MeHg, but not the PCBs, induced loss of mitochondrial membrane potential and release of cytochrome c into the cytosol. Also, pre-treatment with the antioxidant MnTBAP was protective only against cell death induced by MeHg. While caspase activation was absent, the Ca²+-dependent proteases calpains were activated after exposure to MeHg or the selected PCBs. Furthermore, lysosomal disruption was observed in the exposed cells. Accordingly, pre-treatment with the calpain specific inhibitor PD150606 and/or the cathepsin D inhibitor Pepstatin protected against the cytotoxicity of MeHg and PCBs, and the protection was significantly enhanced when the two inhibitors were combined. Simultaneous exposures to lower doses of MeHg and PCBs suggested mostly antagonistic interactions. Taken together, these data indicate that MeHg and PCBs induce caspase-independent cell death via parallel activation of calpains and lysosomal proteases, and that in this model oxidative stress does not play a major role in PCB toxicity.

  19. Functional analysis of the cathepsin-like cysteine protease genes in adult Brugia malayi using RNA interference.

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    Louise Ford

    Full Text Available BACKGROUND: Cathepsin-like enzymes have been identified as potential targets for drug or vaccine development in many parasites, as their functions appear to be essential in a variety of important biological processes within the host, such as molting, cuticle remodeling, embryogenesis, feeding and immune evasion. Functional analysis of Caenorhabditis elegans cathepsin L (Ce-cpl-1 and cathepsin Z (Ce-cpz-1 has established that both genes are required for early embryogenesis, with Ce-cpl-1 having a role in regulating in part the processing of yolk proteins. Ce-cpz-1 also has an important role during molting. METHODS AND FINDINGS: RNA interference assays have allowed us to verify whether the functions of the orthologous filarial genes in Brugia malayi adult female worms are similar. Treatment of B. malayi adult female worms with Bm-cpl-1, Bm-cpl-5, which belong to group Ia of the filarial cpl gene family, or Bm-cpz-1 dsRNA resulted in decreased numbers of secreted microfilariae in vitro. In addition, analysis of the intrauterine progeny of the Bm-cpl-5 or Bm-cpl Pro dsRNA- and siRNA-treated worms revealed a clear disruption in the process of embryogenesis resulting in structural abnormalities in embryos and a varied differential development of embryonic stages. CONCLUSIONS: Our studies suggest that these filarial cathepsin-like cysteine proteases are likely to be functional orthologs of the C. elegans genes. This functional conservation may thus allow for a more thorough investigation of their distinct functions and their development as potential drug targets.

  20. Regulation of cathepsins S and L by cystatin F during maturation of dendritic cells.

    Science.gov (United States)

    Magister, Spela; Obermajer, Nataša; Mirković, Bojana; Svajger, Urban; Renko, Miha; Softić, Adaleta; Romih, Rok; Colbert, Jeff D; Watts, Colin; Kos, Janko

    2012-05-01

    In dendritic cells (DCs) cysteine cathepsins play a key role in antigen processing, invariant chain (Ii) cleavage and regulation of cell adhesion after maturation stimuli. Cystatin F, a cysteine protease inhibitor, is present in DCs in endosomal/lysosomal vesicles and thus has a potential to modulate cathepsin activity. In immature DCs cystatin F colocalizes with cathepsin S. After induction of DC maturation however, it is translocated into lysosomes and colocalizes with cathepsin L. The inhibitory potential of cystatin F depends on the properties of the monomer. We showed that the full-length monomeric cystatin F was a 12-fold stronger inhibitor of cathepsin S than the N-terminally processed cystatin F, whereas no significant difference in inhibition was observed for cathepsins L, H and X. Therefore, the role of cystatin F in regulating the main cathepsin S function in DCs, i.e. the processing of Ii, may depend on the form of the monomer present in endosomal/lysosomal vesicles. On the other hand, intact and truncated monomeric cystatin F are both potent inhibitors of cathepsin L and it is likely that cystatin F could regulate its activity in maturing, adherent DCs, controlling the processing of procathepsin X, which promotes cell adhesion via activation of Mac-1 (CD11b/CD18) integrin receptor.

  1. GILT expression in B cells diminishes cathepsin S steady-state protein expression and activity

    OpenAIRE

    Phipps-Yonas, Hannah; Semik, Vikki; Hastings, Karen Taraszka

    2012-01-01

    MHC class II-restricted Ag processing requires protein degradation in the endocytic pathway for the activation of CD4+ T cells. Gamma-interferon-inducible lysosomal thiol reductase (GILT) facilitates Ag processing by reducing protein disulfide bonds in this compartment. Lysosomal cysteine protease cathepsin S (CatS) contains disulfide bonds and mediates essential steps in MHC class II-restricted processing, including proteolysis of large polypeptides and cleavage of the invariant chain. We so...

  2. The protease degrading sperm histones post-fertilization in sea urchin eggs is a nuclear cathepsin L that is further required for embryo development.

    Directory of Open Access Journals (Sweden)

    Violeta Morin

    Full Text Available Proteolysis of sperm histones in the sea urchin male pronucleus is the consequence of the activation at fertilization of a maternal cysteine protease. We previously showed that this protein is required for male chromatin remodelling and for cell-cycle progression in the newly formed embryos. This enzyme is present in the nucleus of unfertilized eggs and is rapidly recruited to the male pronucleus after insemination. Interestingly, this cysteine-protease remains co-localized with chromatin during S phase of the first cell cycle, migrates to the mitotic spindle in M-phase and is re-located to the nuclei of daughter cells after cytokinesis. Here we identified the protease encoding cDNA and found a high sequence identity to cathepsin proteases of various organisms. A phylogenetical analysis clearly demonstrates that this sperm histone protease (SpHp belongs to the cathepsin L sub-type. After an initial phase of ubiquitous expression throughout cleavage stages, SpHp gene transcripts become restricted to endomesodermic territories during the blastula stage. The transcripts are localized in the invaginating endoderm during gastrulation and a gut specific pattern continues through the prism and early pluteus stages. In addition, a concomitant expression of SpHp transcripts is detected in cells of the skeletogenic lineage and in accordance a pharmacological disruption of SpHp activity prevents growth of skeletal rods. These results further document the role of this nuclear cathepsin L during development.

  3. Characterization of the entire cystatin gene family in barley and their target cathepsin L-like cysteine-proteases, partners in the hordein mobilization during seed germination.

    Science.gov (United States)

    Martinez, Manuel; Cambra, Ines; Carrillo, Laura; Diaz-Mendoza, Mercedes; Diaz, Isabel

    2009-11-01

    Plant cystatins are inhibitors of cysteine-proteases of the papain C1A and legumain C13 families. Cystatin data from multiple plant species have suggested that these inhibitors act as defense proteins against pests and pathogens and as regulators of protein turnover. In this study, we characterize the entire cystatin gene family from barley (Hordeum vulgare), which contain 13 nonredundant genes, and identify and characterize their target enzymes, the barley cathepsin L-like proteases. Cystatins and proteases were expressed and purified from Escherichia coli cultures. Each cystatin was found to have different inhibitory capability against barley cysteine-proteases in in vitro inhibitory assays using specific substrates. Real-time reverse transcription-polymerase chain reaction revealed that inhibitors and enzymes present a wide variation in their messenger RNA expression patterns. Their transcripts were mainly detected in developing and germinating seeds, and some of them were also expressed in leaves and roots. Subcellular localization of cystatins and cathepsin L-like proteases fused to green fluorescent protein demonstrated the presence of both protein families throughout the endoplasmic reticulum and the Golgi complex. Proteases and cystatins not only colocalized but also interacted in vivo in the plant cell, as revealed by bimolecular fluorescence complementation. The functional relationship between cystatins and cathepsin L-like proteases was inferred from their common implication as counterparts of mobilization of storage proteins upon barley seed germination. The opposite pattern of transcription expression in gibberellin-treated aleurones presented by inhibitors and enzymes allowed proteases to specifically degrade B, C, and D hordeins stored in the endosperm of barley seeds.

  4. Unique biological function of cathepsin L in secretory vesicles for biosynthesis of neuropeptides.

    Science.gov (United States)

    Funkelstein, Lydiane; Beinfeld, Margery; Minokadeh, Ardalan; Zadina, James; Hook, Vivian

    2010-12-01

    Neuropeptides are essential for cell-cell communication in the nervous and neuroendocrine systems. Production of active neuropeptides requires proteolytic processing of proneuropeptide precursors in secretory vesicles that produce, store, and release neuropeptides that regulate physiological functions. This review describes recent findings indicating the prominent role of cathepsin L in secretory vesicles for production of neuropeptides from their protein precursors. The role of cathepsin L in neuropeptide production was discovered using the strategy of activity-based probes for proenkephalin-cleaving activity for identification of the enzyme protein by mass spectrometry. The novel role of cathepsin L in secretory vesicles for neuropeptide production has been demonstrated in vivo by cathepsin L gene knockout studies, cathepsin L gene expression in neuroendocrine cells, and notably, cathepsin L localization in neuropeptide-containing secretory vesicles. Cathepsin L is involved in producing opioid neuropeptides consisting of enkephalin, β-endorphin, and dynorphin, as well as in generating the POMC-derived peptide hormones ACTH and α-MSH. In addition, NPY, CCK, and catestatin neuropeptides utilize cathepsin L for their biosynthesis. The neuropeptide-synthesizing functions of cathepsin L represent its unique activity in secretory vesicles, which contrasts with its role in lysosomes. Interesting evaluations of protease gene knockout studies in mice that lack cathepsin L compared to those lacking PC1/3 and PC2 (PC, prohormone convertase) indicate the key role of cathepsin L in neuropeptide production. Therefore, dual cathepsin L and prohormone convertase protease pathways participate in neuropeptide production. Significantly, the recent new findings indicate cathepsin L as a novel 'proprotein convertase' for production of neuropeptides that mediate cell-cell communication in health and disease.

  5. Differential impact of cysteine cathepsins on genetic mouse models of de novo carcinogenesis: cathepsin B as emerging therapeutic target

    Directory of Open Access Journals (Sweden)

    Thomas eReinheckel

    2012-07-01

    Full Text Available Lysosomal cysteine cathepsins belong to a family of 11 human proteolytic enzymes. Some of them correlate with progression in a variety of cancers and therefore are considered as potential therapeutic targets. Until recently, the contribution of individual cathepsins to tumorigenesis and tumor progression remained unknown. By crossing various types of mouse cancer models with mice where specific cathepsins have been ablated, we contributed to this gap of knowledge and will summarize the results in this report. The employed models are the Rip1-Tag2 model for pancreatic neuroendocrine tumors, the K14-HPV16 model for squamous skin and cervical cancers, and the MMTV-PyMT model for metastasizing breast cancer, the KPC model for pancreatic ductal adenocarcinoma, and the APCmin mice developing early stages of intestinal neoplasia. All models harbor mutations in relevant tumor suppressors and/or cell-type specific expression of potent oncogenes, which initiate de novo carcinogenesis in the targeted tissues. In all these models deletion of cathepsin B led to suppression of the aggressiveness of the respective cancer phenotype. Cathepsin B may network with other proteases as it was shown for cathepsin X/Z. In contrast, deletion of cathepsin L was beneficial in the RiP1-Tag2 model, but enhanced tumorigenesis in the APCmin, and the K14-HPV16 mice. A logical consequence of these results would be to further pursue selective inhibition of cathepsin B. Moreover, it became clear that cathepsins B and S derived from cells of the tumor microenvironment support cancer growth. Strikingly, delivery of broad spectrum cysteine cathepsin inhibitors in the tumor microenvironment disrupts the permissive ecosystem of the cancer and results in impaired growth or even in regression of the tumor. In addition, combination of cysteine cathepsin inhibition and standard chemotherapy improves the therapeutic response of the latter.

  6. The Importance of pH in Regulating the Function of the Fasciola hepatica Cathepsin L1 Cysteine Protease

    Science.gov (United States)

    Lowther, Jonathan; Robinson, Mark W.; Donnelly, Sheila M.; Xu, Weibo; Stack, Colin M.; Matthews, Jacqueline M.; Dalton, John P.

    2009-01-01

    The helminth parasite Fasciola hepatica secretes cathepsin L cysteine proteases to invade its host, migrate through tissues and digest haemoglobin, its main source of amino acids. Here we investigated the importance of pH in regulating the activity and functions of the major cathepsin L protease FheCL1. The slightly acidic pH of the parasite gut facilitates the auto-catalytic activation of FheCL1 from its inactive proFheCL1 zymogen; this process was ∼40-fold faster at pH 4.5 than at pH 7.0. Active mature FheCL1 is very stable at acidic and neutral conditions (the enzyme retained ∼45% activity when incubated at 37°C and pH 4.5 for 10 days) and displayed a broad pH range for activity peptide substrates and the protein ovalbumin, peaking between pH 5.5 and pH 7.0. This pH profile likely reflects the need for FheCL1 to function both in the parasite gut and in the host tissues. FheCL1, however, could not cleave its natural substrate Hb in the pH range pH 5.5 and pH 7.0; digestion occurred only at pH≤4.5, which coincided with pH-induced dissociation of the Hb tetramer. Our studies indicate that the acidic pH of the parasite relaxes the Hb structure, making it susceptible to proteolysis by FheCL1. This process is enhanced by glutathione (GSH), the main reducing agent contained in red blood cells. Using mass spectrometry, we show that FheCL1 can degrade Hb to small peptides, predominantly of 4–14 residues, but cannot release free amino acids. Therefore, we suggest that Hb degradation is not completed in the gut lumen but that the resulting peptides are absorbed by the gut epithelial cells for further processing by intracellular di- and amino-peptidases to free amino acids that are distributed through the parasite tissue for protein anabolism. PMID:19172172

  7. The importance of pH in regulating the function of the Fasciola hepatica cathepsin L1 cysteine protease.

    Directory of Open Access Journals (Sweden)

    Jonathan Lowther

    Full Text Available The helminth parasite Fasciola hepatica secretes cathepsin L cysteine proteases to invade its host, migrate through tissues and digest haemoglobin, its main source of amino acids. Here we investigated the importance of pH in regulating the activity and functions of the major cathepsin L protease FheCL1. The slightly acidic pH of the parasite gut facilitates the auto-catalytic activation of FheCL1 from its inactive proFheCL1 zymogen; this process was approximately 40-fold faster at pH 4.5 than at pH 7.0. Active mature FheCL1 is very stable at acidic and neutral conditions (the enzyme retained approximately 45% activity when incubated at 37 degrees C and pH 4.5 for 10 days and displayed a broad pH range for activity peptide substrates and the protein ovalbumin, peaking between pH 5.5 and pH 7.0. This pH profile likely reflects the need for FheCL1 to function both in the parasite gut and in the host tissues. FheCL1, however, could not cleave its natural substrate Hb in the pH range pH 5.5 and pH 7.0; digestion occurred only at pH

  8. Immunolocalization and developmental expression patterns of two cathepsin B proteases (AC-cathB-1, -2) of Angiostrongylus cantonensis.

    Science.gov (United States)

    Yu, Changmao; Wang, Yinan; Zhang, Jing; Fang, Wenzhen; Luo, Damin

    2014-09-01

    In this study we have investigated the anatomic sites of expression and developmental expression patterns of two cathepsin B-like cysteine proteases (AC-cathB-1, -2) of Angiostrongylus cantonensis. The immunolocalization results revealed that native AC-cathBs were found present in the L1 and L3 larvae, female and male adults, and the AC-cathBs were localized mainly on the digestive tract of A. cantonensis and expressed at varied levels and in different patterns in the internal tissues according to their developmental stage. Consistent with the infective stage of L3 is a much more intense staining of AC-cathBs in the esophagus compared with the intestine. In contrast to L3, more abundant signals were located to the intestine of adults, suggesting that nutrition digestion likely to be the main function of the protease at this point. AC-cathBs fluorescent signals were present in excretory pore, excretory tube in lateral cords, and muscular esophagus of larvae, further supported the AC-cathB-1, -2 likely to be released by A. cantonensis as excretory/secretory products. Additionally, only the protein AC-cathB-2 was detected in the reproductive system, especially in the wall of vas deferens, uterus, and oviduct of the parasites, whether the AC-cathB-2 has some function in germ cells development and maturation need to be further characterized. Although the anatomic sites and expression patterns were different in larvae and adults and the corresponding function might not the same, AC-cathB-1 and -2 involved in the host-parasite interaction in addition to digestive function.

  9. Transcriptome Reveals Cathepsin K in Periodontal Ligament Differentiation.

    Science.gov (United States)

    Yamada, S; Ozaki, N; Tsushima, K; Yamaba, S; Fujihara, C; Awata, T; Sakashita, H; Kajikawa, T; Kitagaki, J; Yamashita, M; Yanagita, M; Murakami, S

    2016-08-01

    Periodontal ligaments (PDLs) play an important role in remodeling the alveolar bond and cementum. Characterization of the periodontal tissue transcriptome remains incomplete, and an improved understanding of PDL features could aid in developing new regenerative therapies. Here, we aimed to generate and analyze a large human PDL transcriptome. We obtained PDLs from orthodontic treatment patients, isolated the RNA, and used a vector-capping method to make a complementary DNA library from >20,000 clones. Our results revealed that 58% of the sequences were full length. Furthermore, our analysis showed that genes expressed at the highest frequencies included those for collagen type I, collagen type III, and proteases. We also found 5 genes whose expressions have not been previously reported in human PDL. To access which of the highly expressed genes might be important for PDL cell differentiation, we used real-time polymerase chain reaction to measure their expression in differentiating cells. Among the genes tested, the cysteine protease cathepsin K had the highest upregulation, so we measured its relative expression in several tissues, as well as in osteoclasts, which are known to express high levels of cathepsin K. Our results revealed that PDL cells express cathepsin K at similar levels as osteoclasts, which are both expressed at higher levels than those of the other tissues tested. We also measured cathepsin K protein expression and enzyme activity during cell differentiation and found that both increased during this process. Immunocytochemistry experiments revealed that cathepsin K localizes to the interior of lysosomes. Last, we examined the effect of inhibiting cathepsin K during cell differentiation and found that cathepsin K inhibition stimulated calcified nodule formation and increased the levels of collagen type I and osteocalcin gene expression. Based on these results, cathepsin K seems to regulate collagen fiber accumulation during human PDL cell

  10. Cysteine Cathepsins Activate ELR Chemokines and Inactivate Non-ELR Chemokines.

    Science.gov (United States)

    Repnik, Urska; Starr, Amanda E; Overall, Christopher M; Turk, Boris

    2015-05-29

    Cysteine cathepsins are primarily lysosomal proteases involved in general protein turnover, but they also have specific proteolytic functions in antigen presentation and bone remodeling. Cathepsins are most stable at acidic pH, although growing evidence indicates that they have physiologically relevant activity also at neutral pH. Post-translational proteolytic processing of mature chemokines is a key, yet underappreciated, level of chemokine regulation. Although the role of selected serine proteases and matrix metalloproteases in chemokine processing has long been known, little has been reported about the role of cysteine cathepsins. Here we evaluated cleavage of CXC ELR (CXCL1, -2, -3, -5, and -8) and non-ELR (CXCL9-12) chemokines by cysteine cathepsins B, K, L, and S at neutral pH by high resolution Tris-Tricine SDS-PAGE and matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Whereas cathepsin B cleaved chemokines especially in the C-terminal region, cathepsins K, L, and S cleaved chemokines at the N terminus with glycosaminoglycans modulating cathepsin processing of chemokines. The functional consequences of the cleavages were determined by Ca(2+) mobilization and chemotaxis assays. We show that cysteine cathepsins inactivate and in some cases degrade non-ELR CXC chemokines CXCL9-12. In contrast, cathepsins specifically process ELR CXC chemokines CXCL1, -2, -3, -5, and -8 N-terminally to the ELR motif, thereby generating agonist forms. This study suggests that cysteine cathepsins regulate chemokine activity and thereby leukocyte recruitment during protective or pathological inflammation.

  11. The Expression and Significance of Lysosome Cathepsin D in the Rat Model of Alzheimer’s Disease%大鼠阿尔茨海默病模型中溶酶体组织蛋白酶D的表达及其意义

    Institute of Scientific and Technical Information of China (English)

    李海龙; 李文; 贾阳

    2013-01-01

    目的:观察阿尔茨海默病(AD)大鼠皮质神经元中溶酶体蛋白酶Cathepsin D的表达。方法采用β-淀粉样肽(Aβ)大鼠海马注射制作AD动物模型,用免疫组织化学染色和Western-blot印迹法检测大鼠颞底皮层Cathepsin D的表达。Y迷宫检测大鼠空间辨别性能和学习记忆能力。TUNEL法检测细胞凋亡情况。结果Aβ脑池内灌注造成Aβ沉积的AD模型在行为学和病理学改变上一定程度地模拟了AD。免疫组化和Werstern-bolt检测均显示实验组Cathepsin D阳性神经元数量较假手术组和正常组明显增加(P<0.05)。TUNEL法检测显示AD大鼠颞底皮层神经元凋亡与正常组和假手术组相比显著升高(P<0.05)。结论Cathepsin D在AD大鼠皮层脑组织中表达升高,可能参与了神经元凋亡等病理过程。%Objective To observe the Alzheimer’s disease(AD) rat cortical neurons in lysosome protease Cathepsin D expression.Methods Using amyloid-beta peptide(Aβ) animal model of rat hippocampal injection production AD with immunohistochemical staining and Western blot imprinting method to detect the expression of Cathepsin D end of temporal cortex in rats,and Y maze to test spatial discrimination performance and the ability of learning and memory in rats.TUNEL method to detect apoptosis.Results Caused A beta deposition pool A beta brain perfusion of AD model on behavioural and pathology change part to simulate the AD.Immunohistochemical and Werstern-bolt test showed that the experimental group,Cathepsin D positive neuron numbers significantly increased compared with control group and normal group(P<0.05).TUNEL method showed that the bottom of the AD rats with temporal cortex neuron apoptosis signiifcantly increased compared with normal group and control group(P<0.05).Conclusion Cathepsin D expression increased in brain tissue in AD rats cortex,may participate in the pathological process of neurons apoptosis.

  12. Dissecting the active site of the collagenolytic cathepsin L3 protease of the invasive stage of Fasciola hepatica.

    Directory of Open Access Journals (Sweden)

    Ileana Corvo

    Full Text Available BACKGROUND: A family of secreted cathepsin L proteases with differential activities is essential for host colonization and survival in the parasitic flatworm Fasciola hepatica. While the blood feeding adult secretes predominantly FheCL1, an enzyme with a strong preference for Leu at the S2 pocket of the active site, the infective stage produces FheCL3, a unique enzyme with collagenolytic activity that favours Pro at P2. METHODOLOGY/PRINCIPAL FINDINGS: Using a novel unbiased multiplex substrate profiling and mass spectrometry methodology (MSP-MS, we compared the preferences of FheCL1 and FheCL3 along the complete active site cleft and confirm that while the S2 imposes the greatest influence on substrate selectivity, preferences can be indicated on other active site subsites. Notably, we discovered that the activity of FheCL1 and FheCL3 enzymes is very different, sharing only 50% of the cleavage sites, supporting the idea of functional specialization. We generated variants of FheCL1 and FheCL3 with S2 and S3 residues by mutagenesis and evaluated their substrate specificity using positional scanning synthetic combinatorial libraries (PS-SCL. Besides the rare P2 Pro preference, FheCL3 showed a distinctive specificity at the S3 pocket, accommodating preferentially the small Gly residue. Both P2 Pro and P3 Gly preferences were strongly reduced when Trp67 of FheCL3 was replaced by Leu, rendering the enzyme incapable of digesting collagen. In contrast, the inverse Leu67Trp substitution in FheCL1 only slightly reduced its Leu preference and improved Pro acceptance in P2, but greatly increased accommodation of Gly at S3. CONCLUSIONS/SIGNIFICANCE: These data reveal the significance of S2 and S3 interactions in substrate binding emphasizing the role for residue 67 in modulating both sites, providing a plausible explanation for the FheCL3 collagenolytic activity essential to host invasion. The unique specificity of FheCL3 could be exploited in the design of

  13. Towards delineating functions within the fasciola secreted cathepsin l protease family by integrating in vivo based sub-proteomics and phylogenetics.

    Directory of Open Access Journals (Sweden)

    Russell M Morphew

    2011-01-01

    Full Text Available fasciola hepatica, along with Fasciola gigantica, is the causative agent of fasciolosis, a foodborne zoonotic disease affecting grazing animals and humans worldwide. Pathology is directly related to the release of parasite proteins that facilitate establishment within the host. The dominant components of these excretory-secretory (ES products are also the most promising vaccine candidates, the cathepsin L (Cat L protease family.the sub-proteome of Cat L proteases from adult F. hepatica ES products derived from in vitro culture and in vivo from ovine host bile were compared by 2-DE. The individual Cat L proteases were identified by tandem mass spectrometry with the support of an in-house translated liver fluke EST database. The study reveals plasticity within the CL1 clade of Cat L proteases; highlighted by the identification of a novel isoform and CL1 sub-clade, resulting in a new Cat L phylogenetic analysis including representatives from other adult Cat L phylogenetic clades. Additionally, for the first time, mass spectrometry was shown to be sufficiently sensitive to reveal single amino acid polymorphisms in a resolved 2-DE protein spot derived from pooled population samples.we have investigated the sub-proteome at the population level of a vaccine target family using the Cat L proteases from F. hepatica as a case study. We have confirmed that F. hepatica exhibits more plasticity in the expression of the secreted CL1 clade of Cat L proteases at the protein level than previously realised. We recommend that superfamily based vaccine discovery programmes should screen parasite populations from different host populations and, if required, different host species via sub-proteomic assay in order to confirm the relative expression at the protein level prior to the vaccine development phase.

  14. Towards Delineating Functions within the Fasciola Secreted Cathepsin L Protease Family by Integrating In Vivo Based Sub-Proteomics and Phylogenetics

    Science.gov (United States)

    Morphew, Russell M.; Wright, Hazel A.; LaCourse, E. James; Porter, Joanne; Barrett, John; Woods, Debra J.; Brophy, Peter M.

    2011-01-01

    Background Fasciola hepatica, along with Fasciola gigantica, is the causative agent of fasciolosis, a foodborne zoonotic disease affecting grazing animals and humans worldwide. Pathology is directly related to the release of parasite proteins that facilitate establishment within the host. The dominant components of these excretory-secretory (ES) products are also the most promising vaccine candidates, the cathepsin L (Cat L) protease family. Methodology/Principal Findings The sub-proteome of Cat L proteases from adult F. hepatica ES products derived from in vitro culture and in vivo from ovine host bile were compared by 2-DE. The individual Cat L proteases were identified by tandem mass spectrometry with the support of an in-house translated liver fluke EST database. The study reveals plasticity within the CL1 clade of Cat L proteases; highlighted by the identification of a novel isoform and CL1 sub-clade, resulting in a new Cat L phylogenetic analysis including representatives from other adult Cat L phylogenetic clades. Additionally, for the first time, mass spectrometry was shown to be sufficiently sensitive to reveal single amino acid polymorphisms in a resolved 2-DE protein spot derived from pooled population samples. Conclusions/Significance We have investigated the sub-proteome at the population level of a vaccine target family using the Cat L proteases from F. hepatica as a case study. We have confirmed that F. hepatica exhibits more plasticity in the expression of the secreted CL1 clade of Cat L proteases at the protein level than previously realised. We recommend that superfamily based vaccine discovery programmes should screen parasite populations from different host populations and, if required, different host species via sub-proteomic assay in order to confirm the relative expression at the protein level prior to the vaccine development phase. PMID:21245911

  15. Isolation and molecular characterization of cathepsin L-like cysteine protease cDNAs from Western flower thrips (Frankliniella occidentalis)

    NARCIS (Netherlands)

    Kuipers, A.G.J.; Jongsma, M.A.

    2004-01-01

    Cysteine proteases are predominant in thrips guts (TGs) and, therefore, a suitable target for selecting effective protease inhibitors against western flower thrips (Frankliniella occidentalis). We report the isolation of four full-length cysteine protease cDNA clones from thrips in a two-step PCR ap

  16. Glycosaminoglycan-mediated loss of cathepsin K collagenolytic activity in MPS I contributes to osteoclast and growth plate abnormalities.

    Science.gov (United States)

    Wilson, Susan; Hashamiyan, Saadat; Clarke, Lorne; Saftig, Paul; Mort, John; Dejica, Valeria M; Brömme, Dieter

    2009-11-01

    Mucopolysaccharidoses are a group of lysosomal storage diseases characterized by the build-up of glycosaminoglycans (GAGs) and severe skeletal abnormalities. As GAGs can regulate the collagenolytic activity of the major osteoclastic protease cathepsin K, we investigated the presence and activity of cathepsin K and its co-localization with GAGs in mucopolysaccharidosis (MPS) type I bone. The most dramatic difference between MPS I and wild-type mice was an increase in the amount of cartilage in the growth plates in MPS I bones. Though the number of cathepsin K-expressing osteoclasts was increased in MPS I mice, these mice revealed a significant reduction in cathepsin K-mediated cartilage degradation. As excess heparan and dermatan sulfates inhibit type II collagen degradation by cathepsin K and the spatial overlap between cathepsin K and heparan sulfate strongly increased in MPS I mice, the build up of subepiphyseal cartilage is speculated to be a direct consequence of cathepsin K inhibition by MPS I-associated GAGs. Moreover, isolated MPS I and Ctsk(-/-) osteoclasts displayed fewer actin rings and formed fewer resorption pits on dentine disks, as compared with wild-type cells. These results suggest that the accumulation of GAGs in murine MPS I bone has an inhibitory effect on cathepsin K activity, resulting in impaired osteoclast activity and decreased cartilage resorption, which may contribute to the bone pathology seen in MPS diseases.

  17. [Cathepsin L cysteine protease from Taenia solium: its biological role in the infection and potential use for the immunodiagnosis of neurocysticercosis].

    Science.gov (United States)

    León, Nancy; Padilla, Carlos; Pajuelo, Mónica; Sheen, Patricia; Zimic, Mirko

    2013-07-01

    Taenia solium is a plane helminth responsible for taeniasis and human cysticercosis, the latter being the result of the consumption of infective eggs. Cysticerci can develop in different human tissues, often in the central nervous system, causing neurocysticercosis (NCC). For the diagnosis of NCC, an adequate interpretation of clinical data, neuroimaging results and serological tests are required. However, serological tests could be improved by developing candidate antigens able to increase their sensibility and specificity. In the last years, a series of surface and secretory proteins of T. solium essential for the parasite-host interaction have been described. One of these families is cathepsin L cysteine proteases, which have a predominant role in the development and survival of the parasite. They take part in the tissue invasion, immune response evasion, excystation and encystment of cysticercus. They are considered potential antigens for the immunodiagnosis of neurocysticercosis.

  18. IFN-γ Regulation of Vacuolar pH, Cathepsin D Processing and Autophagy in Mammary Epithelial Cells

    OpenAIRE

    2008-01-01

    In this study we examined the ability of interferon-γ (IFN-γ) to regulate mammary epithelial cell growth and gene expression, with particular emphasis on two genes: Maspin (a member of serine protease inhibitor superfamily), and the lysosomal aspartyl endopeptidase cathepsin D (CatD). The protein products of these genes are critically involved in regulation of multitude of biological functions in different stages of mammary tissue development and remodeling. In addition, the expression of Mas...

  19. Cathepsin K Deficiency Prevents the Aggravated Vascular Remodeling Response to Flow Cessation in ApoE-/- Mice

    OpenAIRE

    Marjo M P C Donners; Bai, Lili; Lutgens, Suzanne P. M.; Wijnands, Erwin; Johnson, Jason; Schurgers, Leon J.; Liu, Cong-Lin; Daemen, Mat; Cleutjens, Kitty B.J.M.; Shi, Guo-Ping; BIESSEN, Erik; Heeneman, Sylvia

    2016-01-01

    Cathepsin K (catK) is a potent lysosomal cysteine protease involved in extracellular matrix (ECM) degradation and inflammatory remodeling responses. Here we have investigated the contribution of catK deficiency on carotid arterial remodeling in response to flow cessation in apoE-/- and wild type (wt) background. Ligation-induced hyperplasia is considerably aggravated in apoE-/- versus wt mice. CatK protein expression was significantly increased in neointimal lesions of apoE-/- compared with w...

  20. Characterization of the Entire Cystatin Gene Family in Barley and Their Target Cathepsin L-Like Cysteine-Proteases, Partners in the Hordein Mobilization during Seed Germination1[W

    Science.gov (United States)

    Martinez, Manuel; Cambra, Ines; Carrillo, Laura; Diaz-Mendoza, Mercedes; Diaz, Isabel

    2009-01-01

    Plant cystatins are inhibitors of cysteine-proteases of the papain C1A and legumain C13 families. Cystatin data from multiple plant species have suggested that these inhibitors act as defense proteins against pests and pathogens and as regulators of protein turnover. In this study, we characterize the entire cystatin gene family from barley (Hordeum vulgare), which contain 13 nonredundant genes, and identify and characterize their target enzymes, the barley cathepsin L-like proteases. Cystatins and proteases were expressed and purified from Escherichia coli cultures. Each cystatin was found to have different inhibitory capability against barley cysteine-proteases in in vitro inhibitory assays using specific substrates. Real-time reverse transcription-polymerase chain reaction revealed that inhibitors and enzymes present a wide variation in their messenger RNA expression patterns. Their transcripts were mainly detected in developing and germinating seeds, and some of them were also expressed in leaves and roots. Subcellular localization of cystatins and cathepsin L-like proteases fused to green fluorescent protein demonstrated the presence of both protein families throughout the endoplasmic reticulum and the Golgi complex. Proteases and cystatins not only colocalized but also interacted in vivo in the plant cell, as revealed by bimolecular fluorescence complementation. The functional relationship between cystatins and cathepsin L-like proteases was inferred from their common implication as counterparts of mobilization of storage proteins upon barley seed germination. The opposite pattern of transcription expression in gibberellin-treated aleurones presented by inhibitors and enzymes allowed proteases to specifically degrade B, C, and D hordeins stored in the endosperm of barley seeds. PMID:19759340

  1. Cathepsin L is crucial for the development of early experimental diabetic nephropathy.

    Science.gov (United States)

    Garsen, Marjolein; Rops, Angelique L W M M; Dijkman, Henry; Willemsen, Brigith; van Kuppevelt, Toin H; Russel, Frans G; Rabelink, Ton J; Berden, Jo H M; Reinheckel, Thomas; van der Vlag, Johan

    2016-11-01

    Proteinuria is one of the first clinical signs of diabetic nephropathy and an independent predictor for the progression to renal failure. Cathepsin L, a lysosomal cysteine protease, can be involved in the development of proteinuria by degradation of proteins that are important for normal podocyte architecture, such as the CD2-associated protein, synaptopodin, and dynamin. Cathepsin L also activates heparanase, a heparan sulfate endoglycosidase previously shown to be crucial for the development of diabetic nephropathy. Here, we evaluated the exact mode of action of cathepsin L in the development of proteinuria in streptozotocin-induced diabetes. Cathepsin L-deficient mice, in contrast to their wild-type littermates, failed to develop albuminuria, mesangial matrix expansion, tubulointerstitial fibrosis, and renal macrophage influx and showed a normal renal function. In wild-type mice the early development of albuminuria correlated with the activation of heparanase and loss of heparan sulfate expression, whereas loss of synaptopodin expression and podocyte damage occurred at a later stage. Thus, cathepsin L is causally involved in the pathogenesis of experimental diabetic nephropathy. Most likely, cathepsin L-dependent heparanase activation is crucial for the development of albuminuria and renal damage. Copyright © 2016 International Society of Nephrology. All rights reserved.

  2. Posttranslational Processing and Modification of Cathepsins and Cystatins

    Directory of Open Access Journals (Sweden)

    Nobuhiko Katunuma

    2010-01-01

    Full Text Available Cathepsins are an essential protease family in all living cells. The cathepsins play an essential roles such as protein catabolism and protein synthesis. To targeting to various organella and to regulate their activity, the post translational-processing and modification play an important role Cathepsins are translated in polysome as the pre-pro-mature forms. The pre-peptide is removed cotranslationally and then translocated to Golgi-apparatus and the pro-part is removed and the mature-part is glycosylated, and the mature-part is targeted into the lysosome mediated by mannose-6-phosphate signal and the mature-part is bound with their coenzymes. The degradation of the mature-part is started by the limited proteolysis of the ordered nicked bonds to make hydrophobic peptides. The peptides are incorporated into phagosome or proteasome after ubiquitinated and are degrade into amino-acids. Cystatins are endogenous inhibitors of cathepsins. Cystatin α which is only located in skin is phosphorylated at the near C-terminus by protein kinase-C, and the phosphorylate-cystatin α is incorporated into cornified envelope and conjugated with filaggrin-fiber by transglutaminase to form the linker-fiber of skin. The cystatin α is modified by glutathione or make their dimmer, and they are inactive. Those modifications are regulated by the redox-potential by the glutathione.

  3. 短蛸自溶中组织蛋白酶L样蛋白酶的活性及分布变化%Changes in Activity and Distribution of Cathepsin L-Like Proteases in Autolytic Octopus (Octopus ocellatus)

    Institute of Scientific and Technical Information of China (English)

    梁晓旺; 宗媛; 林竹一; 李冬梅; 周大勇

    2015-01-01

    The contents of water‐soluble total proteins and collagen proteins ,as well as the activities of endogenous total proteases and cathepsin L‐like proteases were determined in arm muscle of the autolytic octopus induced by ultraviolet (UV ) . Results showed that the octopus became insensitive after UV irradiation .The body of octopus became softened ,and mucoid degeneration took place in epidermis and subcutaneous tissue .The changes in external appearance indicated that autolysis took place .Along with autolysis ,the contents of water‐soluble total proteins and collagen proteins were found to be increased , indicating degradation of structural proteins .At the same time ,the activities of endogenous total proteases and cathepsin L‐like proteases tissue were increased in tissues in wnit mass .The distribution of cathepsin L‐like proteases in arm muscle of the autolytic octopus was in homogeneous . The stained spots of cathepsin L‐like proteases were dense in myocardial trabeculation ,but were relatively sparse in muscle fibers .Along with the progress of autolysis ,the stained spots of cathepsin L‐like proteases were scattered and eventually disappeared ,indicating the dispersion of cathepsin L‐like proteases in tissue .The findings indicated that the endogenous proteases , cathepsin L‐like proteases as representive , took part in the autolysis of octopus .%采用紫外线照射诱导短蛸自溶,检测腕部肌肉组织可溶性蛋白及可溶性胶原蛋白含量变化,监测内源总蛋白酶及内源组织蛋白酶L样蛋白酶活性变化,并应用免疫组织化学法揭示组织蛋白酶L样蛋白酶的组织分布变化。结果显示,短蛸经紫外线照射后,状态迟钝,机体瘫软,表皮及皮下组织发生黏液化,表明发生自溶。随着自溶时间的延长,可溶性总蛋白及可溶性胶原蛋白含量逐渐增加,表明结构蛋白发生降解;单位质量组织的内源蛋白酶总活力及组织蛋

  4. Cathepsins of lepidopteran insects: Aspects and prospects.

    Science.gov (United States)

    Saikhedkar, Nidhi; Summanwar, Aarohi; Joshi, Rakesh; Giri, Ashok

    2015-09-01

    Molecular understanding of lepidopteran physiology has revealed that proteases consist of one of the central regulatory/reacting system for insect growth and survival. Among the various proteases, cathepsins are the most crucial cellular proteases, which play vital roles during insect development. In the present review, we have discussed various aspects of the lepidopteran insect cathepsins, emphasizing their roles in processes like development, growth, metamorphosis, apoptosis and immunity. Cathepsins are categorized into different types on the basis of their sequence diversification, leading to variation in structure and catalytic function. Cathepsins exhibit tissue and stage specific expression pattern which is fine-tuned by a delicate balance of expression, compartmentalization, zymogen activation, inhibition by protein inhibitors and degradation. The indispensability of cathepsins as cellular proteases in the above mentioned processes proposes them as novel targets for designing effective and specific insect controlling strategies.

  5. Characterization of cathepsin B gene from orange-spotted grouper, Epinephelus coioides involved in SGIV infection.

    Science.gov (United States)

    Wei, Shina; Huang, Youhua; Huang, Xiaohong; Cai, Jia; Yan, Yang; Guo, Chuanyu; Qin, Qiwei

    2014-01-01

    The lysosomal cysteine protease cathepsin B of papain family is a key regulator and signaling molecule that involves in various biological processes, such as the regulation of apoptosis and activation of virus. In the present study, cathepsin B gene (Ec-CB) was cloned and characterized from orange-spotted grouper, Epinephelus coioides. The full-length Ec-CB cDNA was composed of 1918 bp and encoded a polypeptide of 330 amino acids with higher identities to cathepsin B of teleosts and mammalians. Ec-CB possessed typical cathepsin B structural features including an N-terminal signal peptide, the propeptide region and the cysteine protease domain which were conserved in other cathepsin B sequences. Phylogenetic analysis revealed that Ec-CB was most closely related to Lutjanus argentimaculatus. RT-PCR analysis showed that Ec-CB transcript was expressed in all the examined tissues which abundant in spleen, kidney and gill. After challenged with Singapore grouper iridovirus (SGIV) stimulation, the mRNA expression of cathepsin B in E. coioides was up-regulated at 24 h post-infection. Subcellular localization analysis revealed that Ec-CB was distributed predominantly in the cytoplasm. When the fish cells (GS or FHM) were treated with the cathepsin B specific inhibitor CA-074Me, the occurrence of CPE induced by SGIV was delayed, and the viral gene transcription was significantly inhibited. Additionally, SGIV-induced typical apoptosis was also inhibited by CA-074Me in FHM cells. Taken together, our results demonstrated that the Ec-CB might play a functional role in SGIV infection.

  6. PIG7 promotes leukemia cell chemosensitivity via lysosomal membrane permeabilization.

    Science.gov (United States)

    Liu, Jiazhuo; Peng, Leiwen; Niu, Ting; Wu, Yu; Li, Jianjun; Wang, Fangfang; Zheng, Yuhuan; Liu, Ting

    2016-01-26

    PIG7 localizes to lysosomal membrane in leukemia cells. Our previous work has shown that transduction of pig7 into a series of leukemia cell lines did not result in either apoptosis or differentiation of most tested cell lines. Interestingly, it did significantly sensitize these cell lines to chemotherapeutic drugs. Here, we further investigated the mechanism underlying pig7-induced improved sensitivity of acute leukemia cells to chemotherapy. Our results demonstrated that the sensitization effect driven by exogenous pig7 was more effective in drug-resistant leukemia cell lines which had lower endogenous pig7 expression. Overexpression of pig7 did not directly activate the caspase apoptotic pathway, but decreased the lysosomal stability. The expression of pig7 resulted in lysosomal membrane permeabilization (LMP) and lysosomal protease (e.g. cathepsin B, D, L) release. Moreover, we also observed increased reactive oxygen species (ROS) and decreased mitochondrial membrane potential (ΔΨm) induced by pig7. Some autophagy markers such as LC3I/II, ATG5 and Beclin-1, and necroptosis maker MLKL were also stimulated. However, intrinsic antagonism such as serine/cysteine protease inhibitors Spi2A and Cystatin C prevented downstream effectors from triggering leukemia cells, which were only on the "verge of apoptosis". When combined with chemotherapy, LMP increased and more proteases were released. Once this process was beyond the limit of intrinsic antagonism, it induced programmed cell death cooperatively via caspase-independent and caspase-dependent pathways.

  7. Angiostrongylus cantonensis cathepsin B-like protease (Ac-cathB-1 is involved in host gut penetration

    Directory of Open Access Journals (Sweden)

    Long Ying

    2015-01-01

    Full Text Available Although the global spread of the emerging zoonosis, human angiostrongyliasis, has attracted increasing attention, understanding of specific gene function has been impeded by the inaccessibility of genetic manipulation of the pathogen nematode causing this disease, Angiostrongylus cantonensis. Many parasitic proteases play key roles in host-parasite interactions, but those of A. cantonensis are always expressed as the inactive form in prokaryotic expression systems, thereby impeding functional studies. Hence, a lentiviral system that drives secreted expression of target genes fused to a Myc-His tag was used to obtain recombinant Ac-cathB-1 with biological activity. Although this class of proteases was always reported to function in nutrition and immune evasion in parasitic nematodes, recombinant Ac-cathB-1 was capable of hydrolysis of fibronectin and laminin as well as the extracellular matrix of IEC-6 monolayer, so that the intercellular space of the IEC-6 monolayer increased 5.15 times as compared to the control, while the shape of the adherent cells partly rounded up. This suggests a probable role for this protease in intestinal epithelial penetration. The inhibition of Ac-cathB-1 enzymatic activity with antiserum partly suppressed larval penetration ability in the isolated intestine. Thus, an effective system for heterologous expression of parasite proteases is presented for studying gene function in A. cantonensis; and Ac-cathB-1 was related to larval penetration ability in the host small intestine.

  8. Using a Caesalpinia echinata Lam. protease inhibitor as a tool for studying the roles of neutrophil elastase, cathepsin G and proteinase 3 in pulmonary edema.

    Science.gov (United States)

    Cruz-Silva, Ilana; Neuhof, Christiane; Gozzo, Andrezza Justino; Nunes, Viviane Abreu; Hirata, Izaura Yoshico; Sampaio, Misako Uemura; Figueiredo-Ribeiro, Rita de Cássia; Neuhof, Heinz; Araújo, Mariana da Silva

    2013-12-01

    Acute lung injury (ALI) is characterized by neutrophil infiltration and the release of proteases, mainly elastase (NE), cathepsin G (Cat G) and proteinase 3 (PR3), which can be controlled by specific endogenous inhibitors. However, inhibitors of these proteases have been isolated from different sources, including plants. For this study, CeEI, or Caesalpinia echinata elastase inhibitor, was purified from C. echinata (Brazil-wood) seeds after acetone fractionation, followed by ion exchange and reversed phase chromatographic steps. Characterization with SDS-PAGE, stability assays, amino acid sequencing and alignment with other protein sequences confirmed that CeEI is a member of the soybean Kunitz trypsin inhibitor family. Like other members of this family, CeEI is a 20 kDa monomeric protein; it is stable within a large pH and temperature range, with four cysteine residues forming two disulfide bridges, conserved amino acid residues and leucine-isoleucine residues in the reactive site. CeEI was able to inhibit NE and Cat G at a nanomolar range (with K(i)s of 1.9 and 3.6 nM, respectively) and inhibited PR3 within a micromolar range (K(i) 3.7 μM), leading to hydrolysis of specific synthetic substrates. In a lung edema model, CeEI reduced the lung weight and pulmonary artery pressure until 180 min after the injection of zymosan-activated polymorphonuclear neutrophils. In experiments performed in the presence of a Cat G and PR3, but not an NE inhibitor, lung edema was reduced only until 150 min and pulmonary artery pressure was similar to that of the control. These results confirm that NE action is crucial to edema establishment and progression. Additionally, CeEI appears to be a useful tool for studying the physiology of pulmonary edema and provides a template for molecular engineering and drug design for ALI therapy.

  9. NMR characterization and conformational analysis of a potent papain-family cathepsin L-like cysteine protease inhibitor with different behaviour in polar and apolar media

    Science.gov (United States)

    Rotondo, Archimede; Ettari, Roberta; Zappalà, Maria; De Micheli, Carlo; Rotondo, Enrico

    2014-11-01

    We recently reported the synthesis, of a potent papain-family cathepsin L-like cysteine protease inhibitor, as new lead compound for the development of new drugs that can be used as antiprotozoal agents. The investigation of its conformational profile is crucial for the in-depth understanding of its biological behaviour. Our careful NMR analysis has been based on the complete and total assignment of 1H, 13C, 15N and 19F signals of the molecule in both CDCl3 and CD3OH, which could reproduce in some way a scenario of polar and not polar phases into the biological environment. In this way it has been unveiled a different behaviour of the molecule in polar and apolar media. In CDCl3 it is possible to define stable conformational arrangements on the basis of the detected through space contacts, whereas, in CD3OH a greater conformational freedom is envisaged: (a) by the overlap of any of the CH2 diastereotopic resonances (unable to distinguish asymmetric molecular sides because of the free rotation about the single bonded chains), (b) by the less definite measured vicinities not consistent with just one conformation and (c) by the evident loss or switching of key intramolecular hydrogen interactions.

  10. Cathepsin-D, a key protease in breast cancer, is up-regulated in obese mouse and human adipose tissue, and controls adipogenesis.

    Directory of Open Access Journals (Sweden)

    Olivier Masson

    Full Text Available The aspartic protease cathepsin-D (cath-D is overexpressed by human epithelial breast cancer cells and is closely correlated with poor prognosis in breast cancer. The adipocyte is one of the most prominent cell types in the tumor-microenvironment of breast cancer, and clinical studies have shown that obesity increases the incidence of breast cancer. Here, we provide the first evidence that cath-D expression is up-regulated in adipose tissue from obese human beings, as well as in adipocytes from the obese C57BI6/J mouse. Cath-D expression is also increased during human and mouse adipocyte differentiation. We show that cath-D silencing in 3T3-F442A murine preadipocytes leads to lipid-depleted cells after adipogenesis induction, and inhibits of the expression of PPARγ, HSL and aP2 adipocyte differentiation markers. Altogether, our findings demonstrate the key role of cath-D in the control of adipogenesis, and suggest that cath-D may be a novel target in obesity.

  11. Heparin modulates the endopeptidase activity of Leishmania mexicana cysteine protease cathepsin L-Like rCPB2.8.

    Directory of Open Access Journals (Sweden)

    Wagner A S Judice

    Full Text Available Cysteine protease B is considered crucial for the survival and infectivity of the Leishmania in its human host. Several microorganism pathogens bind to the heparin-like glycosaminoglycans chains of proteoglycans at host-cell surface to promote their attachment and internalization. Here, we have investigated the influence of heparin upon Leishmania mexicana cysteine protease rCPB2.8 activity.THE DATA ANALYSIS REVEALED THAT THE PRESENCE OF HEPARIN AFFECTS ALL STEPS OF THE ENZYME REACTION: (i it decreases 3.5-fold the k 1 and 4.0-fold the k -1, (ii it affects the acyl-enzyme accumulation with pronounced decrease in k 2 (2.7-fold, and also decrease in k 3 (3.5-fold. The large values of ΔG  =  12 kJ/mol for the association and dissociation steps indicate substantial structural strains linked to the formation/dissociation of the ES complex in the presence of heparin, which underscore a conformational change that prevents the diffusion of substrate in the rCPB2.8 active site. Binding to heparin also significantly decreases the α-helix content of the rCPB2.8 and perturbs the intrinsic fluorescence emission of the enzyme. The data strongly suggest that heparin is altering the ionization of catalytic (Cys(25-S(-/(His(163-Im(+ H ion pair of the rCPB2.8. Moreover, the interaction of heparin with the N-terminal pro-region of rCPB2.8 significantly decreased its inhibitory activity against the mature enzyme.Taken together, depending on their concentration, heparin-like glycosaminoglycans can either stimulate or antagonize the activity of cysteine protease B enzymes during parasite infection, suggesting that this glycoconjugate can anchor parasite cysteine protease at host cell surface.

  12. Eimeripain, a Cathepsin B-Like Cysteine Protease, Expressed throughout Sporulation of the Apicomplexan Parasite Eimeria tenella

    OpenAIRE

    Anaïs Rieux; Simon Gras; Fabien Lecaille; Alisson Niepceron; Marilyn Katrib; Smith, Nicholas C.; Gilles Lalmanach; Fabien Brossier

    2012-01-01

    The invasion and replication of Eimeria tenella in the chicken intestine is responsible for avian coccidiosis, a disease that has major economic impacts on poultry industries worldwide. E. tenella is transmitted to naïve animals via shed unsporulated oocysts that need contact with air and humidity to form the infectious sporulated oocysts, which contain the first invasive form of the parasite, the sporozoite. Cysteine proteases (CPs) are major virulence factors expressed by protozoa. In this ...

  13. Radiation Induces Cathepsin S through ROS-IFN-{gamma} Pathways: Involvement of Cellular Radioresistance

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Haeng Ran; Lee, Yun-Sil [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Kim, Joon [Korea University, Seoul (Korea, Republic of)

    2008-05-15

    Ionizing radiation can elicit an activated phenotype that promotes rapid and persistent remodeling of the extracellular matrix (ECM) through the induction of proteases and growth factors, as well as in response to chronic production of reactive oxygen species (ROS). In addition, the results of previously conducted cDNA microarrays and real-time RT-PCR analysis (unpublished) suggest that radiation-induced mammary tumors were specifically induced by cathepsin S (CTSS), but that dimethylbenz(a)anthracene (DMBA)-induced mammary tumors were not. CTSS is a lysosomal cystein protease that is synthesized as an inactive precursor (36kDa) and activated in the acidic environment of lysosomes by proteolytic cleavage of its propeptide. In this study, we further investigate the mechanism by which CTSS is induced by radiation as well as its function.

  14. The diagnosis of human fascioliasis by enzyme-linked immunosorbent assay (ELISA using recombinant cathepsin L protease.

    Directory of Open Access Journals (Sweden)

    Bibiana Gonzales Santana

    Full Text Available BACKGROUND: Fascioliasis is a worldwide parasitic disease of domestic animals caused by helminths of the genus Fasciola. In many parts of the world, particularly in poor rural areas where animal disease is endemic, the parasite also infects humans. Adult parasites reside in the bile ducts of the host and therefore diagnosis of human fascioliasis is usually achieved by coprological examinations that search for parasite eggs that are carried into the intestine with the bile juices. However, these methods are insensitive due to the fact that eggs are released sporadically and may be missed in low-level infections, and fasciola eggs may be misclassified as other parasites, leading to problems with specificity. Furthermore, acute clinical symptoms as a result of parasites migrating to the bile ducts appear before the parasite matures and begins egg laying. A human immune response to Fasciola antigens occurs early in infection. Therefore, an immunological method such as ELISA may be a more reliable, easy and cheap means to diagnose human fascioliasis than coprological analysis. METHODOLOGY/PRINCIPAL FINDINGS: Using a panel of serum from Fasciola hepatica-infected patients and from uninfected controls we have optimized an enzyme-linked immunosorbent assay (ELISA which employs a recombinant form of the major F. hepatica cathepsin L1 as the antigen for the diagnosis of human fascioliasis. We examined the ability of the ELISA test to discern fascioliasis from various other helminth and non-helminth parasitic diseases. CONCLUSIONS/SIGNIFICANCE: A sensitive and specific fascioliasis ELISA test has been developed. This test is rapid and easy to use and can discriminate fasciola-infected individuals from patients harbouring other parasites with at least 99.9% sensitivity and 99.9% specificity. This test will be a useful standardized method not only for testing individual samples but also in mass screening programs to assess the extent of human fascioliasis in

  15. DRAM1 regulates apoptosis through increasing protein levels and lysosomal localization of BAX

    Science.gov (United States)

    Guan, J-J; Zhang, X-D; Sun, W; Qi, L; Wu, J-C; Qin, Z-H

    2015-01-01

    DRAM1 (DNA damage-regulated autophagy modulator 1) is a TP53 target gene that modulates autophagy and apoptosis. We previously found that DRAM1 increased autophagy flux by promoting lysosomal acidification and protease activation. However, the molecular mechanisms by which DRAM1 regulates apoptosis are not clearly defined. Here we report a novel pathway by which DRAM1 regulates apoptosis involving BAX and lysosomes. A549 or HeLa cells were treated with the mitochondrial complex II inhibitor, 3-nitropropionic acid (3NP), or an anticancer drug, doxorubicin. Changes in the protein and mRNA levels of BAX and DRAM1 and the role of DRAM1 in BAX induction were determined. The interaction between DRAM1 and BAX and its effect on BAX degradation, BAX lysosomal localization, the release of cathepsin B and cytochrome c by BAX and the role of BAX in 3NP- or doxorubicin-induced cell death were studied. The results showed that BAX, a proapoptotic protein, was induced by DRAM1 in a transcription-independent manner. BAX was degraded by autophagy under basal conditions; however, its degradation was inhibited when DRAM1 expression was induced. There was a protein interaction between DRAM1 and BAX and this interaction prolonged the half-life of BAX. Furthermore, upregulated DRAM1 recruited BAX to lysosomes, leading to the release of lysosomal cathepsin B and cleavage of BID (BH3-interacting domain death agonist). BAX mediated the release of mitochondrial cytochrome c, activation of caspase-3 and cell death partially through the lysosome-cathepsin B-tBid pathway. These results indicate that DRAM1 regulates apoptosis by inhibiting BAX degradation. In addition to mitochondria, lysosomes may also be involved in BAX-initiated apoptosis. PMID:25633293

  16. Desferrioxamine (DFO) Reduces the Expression of Cathepsin B and Cathepsin D in Rats Earlier Injured Brain of Subarachnoid Hemorrhage%去铁敏干预蛛网膜下腔出血后溶酶体组织蛋白酶表达研究

    Institute of Scientific and Technical Information of China (English)

    贾阳; 虞正权; 陈罡; 陈传新; 刘泽昊

    2013-01-01

    . Lysosomes may be involved in the process of earlier injured brain of rats after subarachnoid hemorrhage, stabilizing lysosome membrane and reducing the release of protease may provide a new therapeutic approach in early brain injury after SAH.

  17. The Critical Role of Proteolytic Relay through Cathepsins B and E in the Phenotypic Change of Microglia/Macrophage.

    Science.gov (United States)

    Ni, Junjun; Wu, Zhou; Peterts, Christoph; Yamamoto, Kenji; Qing, Hong; Nakanishi, Hiroshi

    2015-09-01

    Proteinase cascades are part of the basic machinery of neuronal death pathways. Neuronal cathepsin B (CatB), a typical cysteine lysosomal protease, plays a critical role in neuronal death through lysosomal leakage or excessive autophagy. On the other hand, much attention has been paid to microglial CatB in neuronal death. We herein show the critical role of proteolytic relay through microglial CatB and CatE in the polarization of microglia/macrophages in the neurotoxic phenotype, leading to hypoxia/ischemia (HI)-induced hippocampal neuronal damage in neonatal mice. HI caused extensive brain injury in neonatal wild-type mice, but not in CatB(-/-) mice. Furthermore, HI-induced polarization of microglia/macrophages in the neurotoxic phenotype followed by the neuroprotective phenotype in wild-type mice. On the other hand, microglia/macrophages exhibited only the early and transient polarization in the neuroprotective phenotype in CatB(-/-) mice. CA-074Me, a specific CatB inhibitor, significantly inhibited the neuronal death of primary cultured hippocampal neurons induced by the conditioned medium from cultured microglia polarized in the neurotoxic phenotype. Furthermore, CA-074Me prevented the activation of nuclear factor-κB (NF-κB) in cultured microglia by inhibiting autophagic inhibitor of κBα degradation following exposure to oxygen-glucose deprivation. Rather surprisingly, CatE increased the CatB expression after HI by the liberation of the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) from microglia through the proteasomal pathway. A significant increase in CatB and CatE levels was found exclusively in microglia/macrophages after HI. Thus, a proteolytic relay through the early CatE/TRAIL-dependent proteosomal and late CatB-dependent autophagic pathways for NF-κB activation may play a critical role in the polarization of microglia/macrophages in the neurotoxic phenotype. Significance statement: Proteinase cascades are part of the basic

  18. The Octyl Ester of Ginsenoside Rh2 Induces Lysosomal Membrane Permeabilization via Bax Translocation.

    Science.gov (United States)

    Chen, Fang; Zhang, Bing; Sun, Yong; Xiong, Zeng-Xing; Peng, Han; Deng, Ze-Yuan; Hu, Jiang-Ning

    2016-04-25

    Ginsenoside Rh2 is a potential pharmacologically active metabolite of ginseng. Previously, we have reported that an octyl ester derivative of ginsenoside Rh2 (Rh2-O), has been confirmed to possess higher bioavailability and anticancer effect than Rh2 in vitro. In order to better assess the possibility that Rh2-O could be used as an anticancer compound, the underlying mechanism was investigated in this study. The present results revealed that lysosomal destabilization was involved in the early stage of cell apoptosis in HepG2 cells induced by Rh2-O. Rh2-O could induce an early lysosomal membrane permeabilization with the release of lysosomal protease cathepsins to the cytosol in HepG2 cells. The Cat B inhibitor (leu) and Cat D inhibitor (pepA) inhibited Rh2-O-induced HepG2 apoptosis as well as tBid production and Δφm depolarization, indicating that lysosomal permeabilization occurred upstream of mitochondrial dysfunction. In addition, Rh2-O induced a significant increase in the protein levels of DRAM1 and Bax (p lysosomes of HepG2 cells. Knockdown of Bax partially inhibited Rh2-O-induced Cat D release from lysosomes. Thus it was concluded that Rh2-O induced apoptosis of HepG2 cells through activation of the lysosomal-mitochondrial apoptotic pathway involving the translocation of Bax to the lysosome.

  19. Lysosomal cell death mechanisms in aging.

    Science.gov (United States)

    Gómez-Sintes, Raquel; Ledesma, María Dolores; Boya, Patricia

    2016-12-01

    Lysosomes are degradative organelles essential for cell homeostasis that regulate a variety of processes, from calcium signaling and nutrient responses to autophagic degradation of intracellular components. Lysosomal cell death is mediated by the lethal effects of cathepsins, which are released into the cytoplasm following lysosomal damage. This process of lysosomal membrane permeabilization and cathepsin release is observed in several physiopathological conditions and plays a role in tissue remodeling, the immune response to intracellular pathogens and neurodegenerative diseases. Many evidences indicate that aging strongly influences lysosomal activity by altering the physical and chemical properties of these organelles, rendering them more sensitive to stress. In this review we focus on how aging alters lysosomal function and increases cell sensitivity to lysosomal membrane permeabilization and lysosomal cell death, both in physiological conditions and age-related pathologies. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. A lysosome-targeted drug delivery system based on sorbitol backbone towards efficient cancer therapy.

    Science.gov (United States)

    Maniganda, Santhi; Sankar, Vandana; Nair, Jyothi B; Raghu, K G; Maiti, Kaustabh K

    2014-09-14

    A straightforward synthetic approach was adopted for the construction of a lysosome-targeted drug delivery system (TDDS) using sorbitol scaffold (Sor) linked to octa-guanidine and tetrapeptide GLPG, a peptide substrate of lysosomal cysteine protease, cathepsin B. The main objective was to efficiently deliver the potential anticancer drug, doxorubicin to the target sites, thereby minimizing dose-limiting toxicity. Three TDDS vectors were synthesized viz., DDS1: Sor-GLPG-Fl, DDS2: Sor-Fl (control) and DDS3: Sor-GLPGC-SMCC-Dox. Dox release from DDS3 in the presence of cathepsin B was studied by kinetics measurement based on the fluorescent property of Dox. The cytotoxicity of DDS1 was assessed and found to be non-toxic. Cellular internalization and colocalization studies of all the 3 systems were carried out by flow cytometry and confocal microscopy utilizing cathepsin B-expressing HeLa cells. DDS1 and DDS3 revealed significant localization within the lysosomes, in contrast to DDS2 (control). The doxorubicin-conjugated carrier, DDS3, demonstrated significant cytotoxic effect when compared to free Dox by MTT assay and also by flow cytometric analysis. The targeted approach with DDS3 is expected to be promising, because it is indicated to be advantageous over free Dox, which possesses dose-limiting toxicity, posing risk of injury to normal tissues.

  1. Streptozotocin-induced diabetes mellitus affects lysosomal enzymes in rat liver

    Directory of Open Access Journals (Sweden)

    G.B. Peres

    2014-06-01

    Full Text Available It has been previously shown that dextran sulfate administered to diabetic rats accumulates in the liver and kidney, and this could be due to a malfunction of the lysosomal digestive pathway. The aim of the present study was to evaluate the expression and activities of lysosomal enzymes that act upon proteins and sulfated polysaccharides in the livers of diabetic rats. Diabetes mellitus was induced by streptozotocin in 26 male Wistar rats (12 weeks old, while 26 age-matched controls received only vehicle. The livers were removed on either the 10th or the 30th day of the disease, weighed, and used to evaluate the activity, expression, and localization of lysosomal enzymes. A 50-60% decrease in the specific activities of cysteine proteases, especially cathepsin B, was observed in streptozotocin-induced diabetes mellitus. Expression (mRNA of cathepsins B and L was also decreased on the 10th, but not on the 30th day. Sulfatase decreased 30% on the 30th day, while glycosidases did not vary (or presented a transitory and slight decrease. There were no apparent changes in liver morphology, and immunohistochemistry revealed the presence of cathepsin B in hepatocyte granules. The decrease in sulfatase could be responsible for the dextran sulfate build-up in the diabetic liver, since the action of sulfatase precedes glycosidases in the digestive pathway of sulfated polysaccharides. Our findings suggest that the decreased activities of cathepsins resulted from decreased expression of their genes, and not from general lysosomal failure, because the levels of glycosidases were normal in the diabetic liver.

  2. Streptozotocin-induced diabetes mellitus affects lysosomal enzymes in rat liver

    Energy Technology Data Exchange (ETDEWEB)

    Peres, G.B. [Universidade Federal de São Paulo, Escola Paulista de Medicina, Departamento de Bioquímica, São Paulo, SP, Brasil, Departamento de Bioquímica, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Juliano, M.A. [Universidade Federal de São Paulo, Escola Paulista de Medicina, Departamento de Biofísica, São Paulo, SP, Brasil, Departamento de Biofísica, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Aguiar, J.A.K.; Michelacci, Y.M. [Universidade Federal de São Paulo, Escola Paulista de Medicina, Departamento de Bioquímica, São Paulo, SP, Brasil, Departamento de Bioquímica, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil)

    2014-05-09

    It has been previously shown that dextran sulfate administered to diabetic rats accumulates in the liver and kidney, and this could be due to a malfunction of the lysosomal digestive pathway. The aim of the present study was to evaluate the expression and activities of lysosomal enzymes that act upon proteins and sulfated polysaccharides in the livers of diabetic rats. Diabetes mellitus was induced by streptozotocin in 26 male Wistar rats (12 weeks old), while 26 age-matched controls received only vehicle. The livers were removed on either the 10{sup th} or the 30{sup th} day of the disease, weighed, and used to evaluate the activity, expression, and localization of lysosomal enzymes. A 50-60% decrease in the specific activities of cysteine proteases, especially cathepsin B, was observed in streptozotocin-induced diabetes mellitus. Expression (mRNA) of cathepsins B and L was also decreased on the 10{sup th}, but not on the 30{sup th} day. Sulfatase decreased 30% on the 30{sup th} day, while glycosidases did not vary (or presented a transitory and slight decrease). There were no apparent changes in liver morphology, and immunohistochemistry revealed the presence of cathepsin B in hepatocyte granules. The decrease in sulfatase could be responsible for the dextran sulfate build-up in the diabetic liver, since the action of sulfatase precedes glycosidases in the digestive pathway of sulfated polysaccharides. Our findings suggest that the decreased activities of cathepsins resulted from decreased expression of their genes, and not from general lysosomal failure, because the levels of glycosidases were normal in the diabetic liver.

  3. Cathepsin B is involved in the heat shock induced cardiomyocytes apoptosis as well as the anti-apoptosis effect of HSP-70.

    Science.gov (United States)

    Hsu, Shu-Fen; Hsu, Chuan-Chih; Cheng, Bor-Chih; Lin, Cheng-Hsien

    2014-11-01

    Cathepsin B is one of the major lysosomal cysteine proteases that plays an important role in apoptosis. Herein, we investigated whether Cathepsin B is involved in cardiomyocyte apoptosis caused by hyperthermic injury (HI) and heat shock protein (HSP)-70 protects these cells from HI-induced apoptosis mediated by Cathepsin. HI was produced in H9C2 cells by putting them in a circulating 43 °C water bath for 120 min, whereas preinduction of HSP-70 was produced in H9C2 cells by mild heat preconditioning (or putting them in 42 °C water bath for 30 min) 8 h before the start of HI. It was found that HI caused both cardiomyocyte apoptosis and increased Cathepsin B activity in H9C2 cells. E-64-c, in addition to reducing Cathepsin B activity, significantly attenuated HI-induced cardiomyocyte apoptosis (evidenced by increased apoptotic cell numbers, increased tuncated Bid (t-Bid), increased cytochrome C, increased caspase-9/-3, and decreased Bcl-2/Bax) in H9C2 cells. In addition, preinduction of HSP-70 by mild heat preconditioning or inhibition of HSP-70 by Tripolide significantly attenuated or exacerbated respectively both the cardiomyocyte apoptosis and increased Cathepsin B activity in H9C2 cells. Furthermore, the beneficial effects of pre-induction of HSP-70 by mild heat production in reducing both cardiomyocyte apoptosis and increased Cathepsin B activity caused by HI can be significantly reduced by Triptolide preconditioning. These results indicate that Cathepsin B is involved in HI-induced cardiomyocyte apoptosis in H9C2 cells and HSP-70 protects these cells from HI-induced cardiomyocyte apoptosis through Cathepsin B pathways.

  4. Design of cell-permeable, fluorescent activity-based probes for the lysosomal cysteine protease asparaginyl endopeptidase (AEP)/legumain

    NARCIS (Netherlands)

    Sexton, Kelly B.; Witte, Martin D.; Blum, Galia; Bogyo, Matthew

    2007-01-01

    Asparaginyl endopeptidase (AEP), also known as legumain, is a cysteine protease that has been ascribed roles in antigen presentation yet its exact role in human biology remains poorly understood. We report here, the use of a positional scanning combinatorial library of peptide AOMKs containing a P1

  5. Therapeutic effects of remediating autophagy failure in a mouse model of Alzheimer disease by enhancing lysosomal proteolysis.

    Science.gov (United States)

    Yang, Dun-Sheng; Stavrides, Philip; Mohan, Panaiyur S; Kaushik, Susmita; Kumar, Asok; Ohno, Masuo; Schmidt, Stephen D; Wesson, Daniel W; Bandyopadhyay, Urmi; Jiang, Ying; Pawlik, Monika; Peterhoff, Corrinne M; Yang, Austin J; Wilson, Donald A; St George-Hyslop, Peter; Westaway, David; Mathews, Paul M; Levy, Efrat; Cuervo, Ana M; Nixon, Ralph A

    2011-07-01

    The extensive autophagic-lysosomal pathology in Alzheimer disease (AD) brain has revealed a major defect: in the proteolytic clearance of autophagy substrates. Autophagy failure contributes on several levels to AD pathogenesis and has become an important therapeutic target for AD and other neurodegenerative diseases. We recently observed broad therapeutic effects of stimulating autophagic-lysosomal proteolysis in the TgCRND8 mouse model of AD that exhibits defective proteolytic clearance of autophagic substrates, robust intralysosomal amyloid-β peptide (Aβ) accumulation, extracellular β-amyloid deposition and cognitive deficits. By genetically deleting the lysosomal cysteine protease inhibitor, cystatin B (CstB), to selectively restore depressed cathepsin activities, we substantially cleared Aβ, ubiquitinated proteins and other autophagic substrates from autolysosomes/lysosomes and rescued autophagic-lysosomal pathology, as well as reduced total Aβ40/42 levels and extracellular amyloid deposition, highlighting the underappreciated importance of the lysosomal system for Aβ clearance. Most importantly, lysosomal remediation prevented the marked learning and memory deficits in TgCRND8 mice. Our findings underscore the pathogenic significance of autophagic-lysosomal dysfunction in AD and demonstrate the value of reversing this dysfunction as an innovative therapeautic strategy for AD.

  6. Involvement of lysosomal dysfunction in autophagosome accumulation and early pathologies in adipose tissue of obese mice.

    Science.gov (United States)

    Mizunoe, Yuhei; Sudo, Yuka; Okita, Naoyuki; Hiraoka, Hidenori; Mikami, Kentaro; Narahara, Tomohiro; Negishi, Arisa; Yoshida, Miki; Higashibata, Rikako; Watanabe, Shukoh; Kaneko, Hiroki; Natori, Daiki; Furuichi, Takuma; Yasukawa, Hiromine; Kobayashi, Masaki; Higami, Yoshikazu

    2017-04-03

    Whether obesity accelerates or suppresses autophagy in adipose tissue is still debatable. To clarify dysregulation of autophagy and its role in pathologies of obese adipose tissue, we focused on lysosomal function, protease maturation and activity, both in vivo and in vitro. First, we showed that autophagosome formation was accelerated, but autophagic clearance was impaired in obese adipose tissue. We also found protein and activity levels of CTSL (cathepsin L) were suppressed in obese adipose tissue, while the activity of CTSB (cathepsin B) was significantly enhanced. Moreover, cellular senescence and inflammasomes were activated in obese adipose tissue. In 3T3L1 adipocytes, downregulation of CTSL deteriorated autophagic clearance, upregulated expression of CTSB, promoted cellular senescence and activated inflammasomes. Upregulation of CTSB promoted additional activation of inflammasomes. Therefore, we suggest lysosomal dysfunction observed in obese adipose tissue leads to lower autophagic clearance, resulting in autophagosome accumulation. Simultaneously, lysosomal abnormalities, including deteriorated CTSL function and compensatory activation of CTSB, caused cellular senescence and inflammasome activation. Our findings strongly suggest lysosomal dysfunction is involved in early pathologies of obese adipose tissue.

  7. Cathepsin B gene disruption induced Leishmania donovani proteome remodeling implies cathepsin B role in secretome regulation.

    Directory of Open Access Journals (Sweden)

    Teklu Kuru Gerbaba

    Full Text Available Leishmania cysteine proteases are potential vaccine candidates and drug targets. To study the role of cathepsin B cysteine protease, we have generated and characterized cathepsin B null mutant L. donovani parasites. L. donovani cathepsin B null mutants grow normally in culture, but they show significantly attenuated virulence inside macrophages. Quantitative proteome profiling of wild type and null mutant parasites indicates cathepsin B disruption induced remodeling of L. donovani proteome. We identified 83 modulated proteins, of which 65 are decreased and 18 are increased in the null mutant parasites, and 66% (55/83 of the modulated proteins are L. donovani secreted proteins. Proteins involved in oxidation-reduction (trypanothione reductase, peroxidoxins, tryparedoxin, cytochromes and translation (ribosomal proteins are among those decreased in the null mutant parasites, and most of these proteins belong to the same complex network of proteins. Our results imply virulence role of cathepsin B via regulation of Leishmania secreted proteins.

  8. Analysis of the Proteolytic Processing of ABCA3: Identification of Cleavage Site and Involved Proteases.

    Directory of Open Access Journals (Sweden)

    Nicole Hofmann

    Full Text Available ABCA3 is a lipid transporter in the limiting membrane of lamellar bodies in alveolar type II cells. Mutations in the ABCA3 gene cause respiratory distress syndrome in new-borns and childhood interstitial lung disease. ABCA3 is N-terminally cleaved by an as yet unknown protease, a process believed to regulate ABCA3 activity.The exact site where ABCA3 is cleaved was localized using mass spectrometry (MS. Proteases involved in ABCA3 processing were identified using small molecule inhibitors and siRNA mediated gene knockdown. Results were verified by in vitro digestion of a synthetic peptide substrate mimicking ABCA3's cleavage region, followed by MS analysis.We found that cleavage of ABCA3 occurs after Lys174 which is located in the proteins' first luminal loop. Inhibition of cathepsin L and, to a lesser extent, cathepsin B resulted in attenuation of ABCA3 cleavage. Both enzymes showed activity against the ABCA3 peptide in vitro with cathepsin L being more active.We show here that, like some other proteins of the lysosomal membrane, ABCA3 is a substrate of cathepsin L. Therefore, cathepsin L may represent a potential target to therapeutically influence ABCA3 activity in ABCA3-associated lung disease.

  9. Impact of high glucose and AGEs on cultured kidney-derived cells. Effects on cell viability, lysosomal enzymes and effectors of cell signaling pathways.

    Science.gov (United States)

    Peres, Giovani B; Schor, Nestor; Michelacci, Yara M

    2017-04-01

    We have previously reported decreased expression and activities of lysosomal cathepsins B and L in diabetic kidney. Relevant morphological changes were observed in proximal tubules, suggesting that these cells are implicated in the early stages of the disease. The aim of the present study was to investigate the mechanisms that lead to these changes. The effects of high glucose (HG) and advanced glycation end products (AGEs) on cell viability, lysosomal enzymes and other effectors of cell signaling of cultured kidney cells were studied. HG increased viable mesangial cells (ihMC) in 48 h, while epithelial tubular cells were not affected (LLC-PK1 and MDCK). In contrast, the number of viable cells was markedly decreased, for all cell lines, by AGE-BSA. Concerning lysosomal enzymes, the main cysteine-protease expressed by these cells was cathepsin B, and its concentration was much higher in epithelial than in mesangial cells. Exposure to HG had no effect on the cathepsin B activity, but AGE-BSA caused a marked decrease in LLC-PK1, and increased the enzyme activities in the other cell lines. The levels of nitric oxide (NO) was increased by AGE-BSA in all cell lines, suggesting oxidative stress, and Western blotting has shown that, among the investigated proteins, cathepsin B, mTOR and transcription factor EB (TFEB) were the most significantly affected by exposure to AGE-BSA. As mTOR induces anabolism and inhibits autophagy, and TFEB is a master transcription factor for lysosomal enzymes, it is possible that this pathway plays a role in the inhibition of lysosomal enzymes in proximal tubule cells.

  10. Identification of putative cathepsin S in mangrove red snapper Lutjanus argentimaculatus and its role in antigen presentation.

    Science.gov (United States)

    Zhou, Jin; Li, Lei; Cai, Zhong-Hua

    2012-05-01

    Cathepsin S (CTSS) is a key enzyme employed in the histocompatibility complex (MHC) class II-restricted antigens, which are presented by processing class II-associated invariant chains and loaded antigen peptides into class II molecules. To date, little is known about the character and function of CTSS in fish. In the present study, we screened and identified a CTSS cDNA sequence from the mangrove red snapper head kidney cDNA library. The full-length CTSS cDNA contained 1339-bp nucleotide acids encoding 337 amino acids. The sequence shared high identity and similarity with other known cathepsins, especially CTSS (about 56-78% and 79-89%, respectively). Like other cathepsins, the deduced peptide consisted of regions with N-terminal signal peptides, propeptides, and mature peptides. A typical ERWNIN motif in L-like cathepsins and three conservative catalytic activity sites forming a catalytic triad active center were respectively identified in the pro-peptide and mature peptide regions of CTSS. Phylogenetic analysis revealed that mangrove red snapper CTSS was located in the CTSS clade belonging to the L-like cathepsin group, and evolved from the same ancestry. To further characterize the biological activity of the putative CTSS of mangrove snapper, CTSS was expressed in Escherichia coli M15 strains. Like other mammalian CTSS, the recombinant CTSS (rCTSS) had autocatalytic activation properties, can remove pro-peptides, and can release active mature peptides. Active CTSS had the ability to catalyze Z-Phe-Arg-AMC substrates in acidic conditions (pH 5.0) and weak alkaline environments (pH 7.5); this activity could be blocked by the cysteine protease inhibitor E-64. Active CTSS can process recombinant Ii chains (invariant chains) in a stepwise manner in vitro. The results indicate that mangrove red snapper CTSS is a lysosomal cysteine protease family member with a key role in antigen processing in fish.

  11. Construction of a plasmid coding for green fluorescent protein tagged cathepsin L and data on expression in colorectal carcinoma cells

    Directory of Open Access Journals (Sweden)

    Tripti Tamhane

    2015-12-01

    Full Text Available The endo-lysosomal cysteine cathepsin L has recently been shown to have moonlighting activities in that its unexpected nuclear localization in colorectal carcinoma cells is involved in cell cycle progression (Tamhane et al., 2015 [1]. Here, we show data on the construction and sequence of a plasmid coding for human cathepsin L tagged with an enhanced green fluorescent protein (phCL-EGFP in which the fluorescent protein is covalently attached to the C-terminus of the protease. The plasmid was used for transfection of HCT116 colorectal carcinoma cells, while data from non-transfected and pEGFP-N1-transfected cells is also shown. Immunoblotting data of lysates from non-transfected controls and HCT116 cells transfected with pEGFP-N1 and phCL-EGFP, showed stable expression of cathepsin L-enhanced green fluorescent protein chimeras, while endogenous cathepsin L protein amounts exceed those of hCL-EGFP chimeras. An effect of phCL-EGFP expression on proliferation and metabolic states of HCT116 cells at 24 h post-transfection was observed.

  12. Haplodeficiency of Cathepsin D does not affect cerebral amyloidosis and autophagy in APP/PS1 transgenic mice.

    Science.gov (United States)

    Cheng, Shaowu; Wani, Willayat Y; Hottman, David A; Jeong, Angela; Cao, Dongfeng; LeBlanc, Kyle J; Saftig, Paul; Zhang, Jianhua; Li, Ling

    2017-07-01

    Autophagy and lysosomal function are important for protein homeostasis and their dysfunction have been associated with Alzheimer's disease (AD). Increased immunoreactivities of an important lysosomal protease, cathepsin D (Cat D), are evident in amyloid plaques and neurons in patients with AD. This study tests the hypothesis that deleting one allele of the cathepsin D gene (Ctsd) impacts cerebral β-amyloidosis in amyloid-β precursor protein (APP)sw/PS1dE9 (APP/PS1) double transgenic mice. Despite a significant 38% decrease in Cat D level in APP/PS1/Ctsd+/- compared with APP/PS1/Ctsd+/+ mice, no changes in steady state levels and deposition of Aβ were found in the brain. There were also no differences in APP processing, the levels of two other Aβ-degrading proteases, the levels of autophagy related protein, such as LAMP2, P62, LC3-I, LC3-II, and Beclin-1, or the markers of neuroinflammation, observed between the APP/PS1/Ctsd+/+ and APP/PS1/Ctsd+/- mice. Our findings demonstrate that in wild-type mice, Cat D protein levels are either in excess or redundant with other factors in the brain, and at least one allele of Ctsd is dispensable for cerebral β-amyloidosis and autophagy in APP/PS1 transgenic mice. © 2017 International Society for Neurochemistry.

  13. Involvement of Fenneropenaeus chinensis Cathepsin C in antiviral immunity.

    Science.gov (United States)

    Wang, Shuai; Shi, Li-Jie; Liu, Ning; Chen, An-Jing; Zhao, Xiao-Fan; Wang, Jin-Xing

    2012-10-01

    Cathepsin C (Cath C) is a lysosomal cysteine protease that belongs to the papain superfamily. Cath C is capable of activating many chymotrypsin-like serine proteases and is reported to be a central coordinator for the activation of many serine proteinases in immune and inflammatory cells. In this study, Cath C cDNA was cloned from Fenneropenaeus chinensis (Fc). The complete cDNA of Fc-Cath C in Chinese white shrimp was found to be 1445-base pairs (bp) long. It contained an open reading frame (ORF) 1356-bp long and encoded a 451-amino acid residue protein, including a 17-amino acid residue signal peptide. Real-time PCR analysis results indicated that Fc-Cath C was present in all the tissues detected and exhibited high level of transcription in the hepatopancreas. In hemocytes, hepatopancreas, gills and intestine, Fc-Cath C was upregulated after stimulation by the Vibrio anguillarum and the white spot syndrome viruses (WSSVs). Replication of the WSSV increased after the injection of Fc-Cath C antiserum or knockdown Cath C by RNA interference. These results implied that Cath C might play a crucial role in the antiviral immune response of shrimp.

  14. Lysosomal and mitochondrial permeabilization mediates zinc(II) cationic phthalocyanine phototoxicity.

    Science.gov (United States)

    Marino, Julieta; García Vior, María C; Furmento, Verónica A; Blank, Viviana C; Awruch, Josefina; Roguin, Leonor P

    2013-11-01

    In order to find a novel photosensitizer to be used in photodynamic therapy for cancer treatment, we have previously showed that the cationic zinc(II) phthalocyanine named Pc13, the sulfur-linked dye 2,9(10),16(17),23(24)-tetrakis[(2-trimethylammonium) ethylsulfanyl]phthalocyaninatozinc(II) tetraiodide, exerts a selective phototoxic effect on human nasopharynx KB carcinoma cells and induces an apoptotic response characterized by an increase in the activity of caspase-3. Since the activation of an apoptotic pathway by chemotherapeutic agents contributes to the elimination of malignant cells, in this study we investigated the molecular mechanisms underlying the antitumor action of Pc13. We found that after light exposure, Pc13 induced the production of reactive oxygen species (ROS), which are mediating the resultant cytotoxic action on KB cells. ROS led to an early permeabilization of lysosomal membranes as demonstrated by the reduction of lysosome fluorescence with acridine orange and the release of lysosomal proteases to cytosol. Treatment with antioxidants inhibited ROS generation, preserved the integrity of lysosomal membrane and increased cell proliferation in a concentration-dependent manner. Lysosome disruption was followed by mitochondrial depolarization, cytosolic release of cytochrome C and caspases activation. Although no change in the total amount of Bax was observed, the translocation of Bax from cytosol to mitochondria, the cleavage of the pro-apoptotic protein Bid, together with the decrease of the anti-apoptotic proteins Bcl-XL and Bcl-2 indicated the involvement of Bcl-2 family proteins in the induction of the mitochondrial pathway. It was also demonstrated that cathepsin D, but not caspase-8, contributed to Bid cleavage. In conclusion, Pc13-induced cell photodamage is triggered by ROS generation and activation of the mitochondrial apoptotic pathway through the release of lysosomal proteases. In addition, our results also indicated that Pc13 induced

  15. Cysteine cathepsin activity suppresses osteoclastogenesis of myeloid-derived suppressor cells in breast cancer

    NARCIS (Netherlands)

    Edgington-Mitchell, L.E.; Rautela, J.; Duivenvoorden, H.M.; Jayatilleke, K.M.; Linden, W.A. van der; Verdoes, M.; Bogyo, M.; Parker, B.S.

    2015-01-01

    Cysteine cathepsin proteases contribute to many normal cellular functions, and their aberrant activity within various cell types can contribute to many diseases, including breast cancer. It is now well accepted that cathepsin proteases have numerous cell-specific functions within the tumor microenvi

  16. Cathepsin K modulates invasion, migration and adhesion of oral squamous cell carcinomas in vitro.

    Science.gov (United States)

    Yamashita, K; Iwatake, M; Okamoto, K; Yamada, S-I; Umeda, M; Tsukuba, T

    2017-05-01

    Cathepsin K was initially discovered as an osteoclast-specific cysteine proteinase, but the enzyme is also expressed in various cancers including oral squamous cell carcinomas. This study aimed to clarify the function of cathepsin K in oral squamous cell carcinomas. Expression levels of cathepsin K were examined in six types of cell carcinomas. Carcinomas overexpressing cathepsin K were constructed. Effects of cathepsin K overexpression and treatment with odanacatib, a specific cathepsin K inhibitor, on cell invasion, migration and adhesion were analysed. Different levels of cathepsin K were expressed in carcinomas. Cathepsin K was predominantly localised in lysosomes. Cathepsin K overexpression impaired the proliferation of carcinomas. Invasion analysis showed that cathepsin K overexpression enhanced invasion and migration of carcinomas, whereas inhibition of cathepsin K by odanacatib caused the opposite effects in carcinomas. Cathepsin K overexpression also increased cell adhesion and slightly increased surface expression of the adhesion receptor CD29/integrin β1 . The enhanced invasion of carcinomas resulting from cathepsin K overexpression is probably due to the increased cell migration and adhesion. Thus, cathepsin K is implicated not only in protein degradation but also in invasion, migration and adhesion of oral squamous cell carcinomas. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. Cathepsin B and L inhibitors: a patent review (2010 - present).

    Science.gov (United States)

    Li, Yu-Yao; Fang, Jing; Ao, Gui-Zhen

    2017-06-01

    Cathepsins play an important role in protein degradation and processing. Aberrant cathepsin B or L is closely associated with many serious diseases such as cancer, osteoporosis and autoimmune disorders. Therefore, development of potent and selective cathepsin B and L inhibitors has aroused much attention in recent years. Although several classes of cathepsin inhibitors are presently available, there are still some problems to solve, such as broad-spectrum inhibition to protease, specially cysteine proteases, which lead to unpredictable side effects in clinical trials. Therefore, it is very necessary to discovery new scaffolds and new application of cathepsin B and L inhibitors for developing therapeutic agents for treating diseases mediated by cathepsin B or L. Areas covered: This updated review summarizes new patents on cathepsin B and L inhibitors from 2010 to present. Expert opinion: The review gives the latest development in the area of inhibitors of cathepsin B and L, which have been considered key therapeutic targets for the development of drugs treating related diseases. This review puts emphasis on the discovery of novel small molecule inhibitors of cathepsin B and L, as well as their new application as new therapeutic agents.

  18. Skeletal muscle protease activities in the early growth and development of wild Atlantic salmon (Salmo salar L.).

    Science.gov (United States)

    Lysenko, Liudmila A; Kantserova, Nadezda P; Kaivarainen, Elena I; Krupnova, Marina Yu; Nemova, Nina N

    2017-09-01

    Growth-related dynamics of intracellular protease activities in four year classes of the Atlantic salmon (Salmo salar L. 1758) parr and smolts inhabiting salmon rivers of northwestern Russia (the White Sea basin) were studied. Cathepsin B, cathepsin D, proteasome, and calpain activities in the skeletal muscles of salmon were assessed to investigate their relative contribution to the total protein degradation as well as to young fish growth process. It was confirmed that calpain activity dominates in salmon muscles while proteasome plays a minor role, in contrast to terrestrial vertebrates. Calpain and proteasome activities were maximal at the early post-larval stage (in parrs 0+) and declined with age (parrs 1+ through 2+) dropping to the lowest level in salmon smolts. Annual growth increments and proteolytic activities of calpains and proteasome in the muscles of salmon juveniles changed with age in an orchestrated manner, while lysosomal cathepsin activities increased with age. Comparing protease activities and growth increments in salmon parr and smolts we suggested that the partial suppression of the protein degradation could be a mechanism stimulating efficient growth in smoltifying salmon. Growth and smoltification-related dynamics of protease activities was quite similar in salmon populations from studied spawning rivers, such as Varzuga and Indera; however, some habitat-related differences were observed. Growth increments and protease activities varied in salmon parr 0+ (but not on later ages) inhabiting either main rivers or small tributaries apparently due to habitat difference on the resources for fish growth. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Proteases inhibition assessment on PC12 and NGF treated cells after oxygen and glucose deprivation reveals a distinct role for aspartyl proteases.

    Directory of Open Access Journals (Sweden)

    Aristidis Kritis

    Full Text Available Hypoxia is a severe stressful condition and induces cell death leading to neuronal loss both to the developing and adult nervous system. Central theme to cellular death is the activation of different classes of proteases such as caspases calpains and cathepsins. In the present study we investigated the involvement of these proteases, in the hypoxia-induced PC12 cell death. Rat PC12 is a model cell line for experimentation relevant to the nervous system and several protocols have been developed for either lethal hypoxia (oxygen and glucose deprivation OGD or ischemic preconditioning (IPS. Nerve Growth Factor (NGF treated PC12 differentiate to a sympathetic phenotype, expressing neurites and excitability. Lethal hypoxia was established by exposing undifferentiated and NGF-treated PC12 cells to a mixture of N(2/CO(2 (93:5% in DMEM depleted of glucose and sodium pyruvate for 16 h. The involvement of caspases, calpains and lysosomal cathepsins D and E to the cell death induced by lethal OGD was investigated employing protease specific inhibitors such as z-VAD-fmk for the caspases, MDL28170 for the calpains and pepstatin A for the cathepsins D and E. Our findings show that pepstatin A provides statistically significant protection from cell death of both naive and NGF treated PC12 cells exposed to lethal OGD. We propose that apart from the established processes of apoptosis and necrosis that are integral components of lethal OGD, the activation of cathepsins D and E launches additional cell death pathways in which these proteases are key partners.

  20. Inhibition of cathepsin K for treatment of osteoporosis.

    Science.gov (United States)

    Boonen, Steven; Rosenberg, Elizabeth; Claessens, Frank; Vanderschueren, Dirk; Papapoulos, Socrates

    2012-03-01

    Cathepsin K is the protease that is primarily responsible for the degradation of bone matrix by osteoclasts. Inhibitors of cathepsin K are in development for treatment of osteoporosis. Currently available antiresorptive drugs interfere with osteoclast function. They inhibit both bone resorption and formation, due to the coupling between these processes. Cathepsin K inhibitors, conversely, target the resorption process itself and may not interfere with osteoclast stimulation of bone formation. In fact, when cathepsin K is absent or inhibited in mice, rabbits, or monkeys, bone formation is maintained or increased. In humans, inhibition of cathepsin K is associated with sustained reductions in bone resorption markers but with smaller and transient reductions in bone formation markers. The usefulness of cathepsin K inhibitors in osteoporosis is now being examined in phase 2 and phase 3 clinical trials of postmenopausal osteoporotic women.

  1. Cathepsins and cystatin C in atherosclerosis and obesity.

    Science.gov (United States)

    Lafarge, Jean-Charles; Naour, Nadia; Clément, Karine; Guerre-Millo, Michèle

    2010-11-01

    Given the increasing prevalence of human obesity worldwide, there is an urgent need for a better understanding of the molecular mechanisms linking obesity to metabolic and cardiovascular diseases. Our knowledge is nevertheless limited regarding molecules linking adipose tissue to downstream complications. The importance of cathepsins was brought to light in this context. Through a large scale transcriptomic analysis, our group recently identified the gene encoding cathepsin S as one of the most deregulated gene in the adipose tissue of obese subjects and positively correlated with body mass index. Other members of the cathepsin family are expressed in the adipose tissue, including cathepsin K and cathepsin L. Given their implication in atherogenesis, these proteases could participate into the well established deleterious relationship between enlarged adipose tissue and increased cardiovascular risk. Here, we review the clinical and experimental evidence relevant to the role of cathepsins K, L and S and their most abundant endogenous inhibitor, cystatin C, in atherosclerosis and in obesity.

  2. Molecular Cloning and Sequencing of Channel Catfish, Ictalurus punctatus, Cathepsin H and L cDNA

    Science.gov (United States)

    Cathepsin H and L, a lysosomal cysteine endopeptidase of the papain family, are ubiquitously expressed and involve in antigen processing. In this communication, the channel catfish cathepsin H and L transcripts were sequenced and analyzed. Total RNA from tissues was extracted and cDNA libraries we...

  3. Molecular Cloning, Sequencing and Characterization of Channel Catfish (Ictalurus punctatus, Rafinesque 1818) Cathepsin S Gene

    Science.gov (United States)

    Cathepsin S is a lysosomal cysteine endopeptidase of the papain family. Our preliminary results showed the up-regulation of cathepsin S (CTSS) transcript during the early stage of Edwardsiella ictaluri infection. This prompted us to speculate that the CTSS may play a role in infection. In this re...

  4. MDMA induces cardiac contractile dysfunction through autophagy upregulation and lysosome destabilization in rats.

    Science.gov (United States)

    Shintani-ishida, Kaori; Saka, Kanju; Yamaguchi, Koji; Hayashida, Makiko; Nagai, Hisashi; Takemura, Genzou; Yoshida, Ken-ichi

    2014-05-01

    The underlying mechanisms of cardiotoxicity of 3,4-methylenedioxymethylamphetamine (MDMA, "ecstasy") abuse are unclear. Autophagy exerts either adaptive or maladaptive effects on cardiac function in various pathological settings, but nothing is known on the role of autophagy in the MDMA cardiotoxicity. Here, we investigated the mechanism through which autophagy may be involved in MDMA-induced cardiac contractile dysfunction. Rats were injected intraperitoneally with MDMA (20mg/kg) or saline. Left ventricular (LV) echocardiography and LV pressure measurement demonstrated reduction of LV systolic contractility 24h after MDMA administration. Western blot analysis showed a time-dependent increase in the levels of microtubule-associated protein light chain 3-II (LC3-II) and cathepsin-D after MDMA administration. Electron microscopy showed the presence of autophagic vacuoles in cardiomyocytes. MDMA upregulated phosphorylation of adenosine monophosphate-activated protein kinase (AMPK) at Thr172, mammalian target of rapamycin (mTOR) at Thr2446, Raptor at Ser792, and Unc51-like kinase (ULK1) at Ser555, suggesting activation of autophagy through the AMPK-mTOR pathway. The effects of autophagic inhibitors 3-methyladenine (3-MA) and chloroquine (CQ) on LC3-II levels indicated that MDMA enhanced autophagosome formation, but attenuated autophagosome clearance. MDMA also induced release of cathepsins into cytosol, and western blotting and electron microscopy showed cardiac troponin I (cTnI) degradation and myofibril damage, respectively. 3-MA, CQ, and a lysosomal inhibitor, E64c, inhibited cTnI proteolysis and improved contractile dysfunction after MDMA administration. In conclusion, MDMA causes lysosome destabilization following activation of the autophagy-lysosomal pathway, through which released lysosomal proteases damage myofibrils and induce LV systolic dysfunction in rat heart.

  5. Lysosomal membrane permeabilization: Carbon nanohorn-induced reactive oxygen species generation and toxicity by this neglected mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Mei, E-mail: happy_deercn@163.com [Nanotube Research Center, National Institute of Advanced Industrial Science and Technology 5-2, 1-1-1 Higashi, Tsukuba 305-8565 (Japan); Zhang, Minfang; Tahara, Yoshio; Chechetka, Svetlana; Miyako, Eijiro [Nanotube Research Center, National Institute of Advanced Industrial Science and Technology 5-2, 1-1-1 Higashi, Tsukuba 305-8565 (Japan); Iijima, Sumio [Nanotube Research Center, National Institute of Advanced Industrial Science and Technology 5-2, 1-1-1 Higashi, Tsukuba 305-8565 (Japan); Faculty of Science and Technology, Meijo University, 1-501 Shiogamaguchi, Tenpaku, Nagoya 468-8502 (Japan); Yudasaka, Masako, E-mail: m-yudasaka@aist.go.jp [Nanotube Research Center, National Institute of Advanced Industrial Science and Technology 5-2, 1-1-1 Higashi, Tsukuba 305-8565 (Japan)

    2014-10-01

    Understanding the molecular mechanisms responsible for the cytotoxic effects of carbon nanomaterials is important for their future biomedical applications. Carbon nanotubular materials induce the generation of reactive oxygen species (ROS), which causes cell death; however, the exact details of this process are still unclear. Here, we identify a mechanism of ROS generation that is involved in the apoptosis of RAW264.7 macrophages caused by excess uptake of carbon nanohorns (CNHs), a typical type of carbon nanotubule. CNH accumulated in the lysosomes, where they induced lysosomal membrane permeabilization (LMP) and the subsequent release of lysosomal proteases, such as cathepsins, which in turn caused mitochondrial dysfunction and triggered the generation of ROS in the mitochondria. The nicotinamide adenine dinucleotide phosphate oxidase was not directly involved in CNH-related ROS production, and the ROS generation cannot be regulated by mitochondrial electron transport chain. ROS fed back to amplify the mitochondrial dysfunction, leading to the subsequent activation of caspases and cell apoptosis. Carbon nanotubules commonly accumulate in the lysosomes after internalization in cells; however, lysosomal dysfunction has not attracted much attention in toxicity studies of these materials. These results suggest that LMP, a neglected mechanism, may be the primary reason for carbon nanotubule toxicity. - Highlights: • We clarify an apoptotic mechanism of RAW264.7 cells caused by carbon nanohorns. • In the meantime, the mechanism of CNH-induced ROS generation is identified. • LMP is the initial factor of CNH-induced ROS generation and cell death. • Cathepsins work as mediators that connect LMP and mitochondrial dysfunction.

  6. Distribution of cathepsin L in human umbilical cord tissues.

    Science.gov (United States)

    Gogiel, Tomasz; Wolańska, Małgorzata; Galewska, Zofia; Kinalski, Piotr; Sobolewski, Krzysztof; Romanowicz, Lech

    2017-01-01

    The extracellular matrix components show specific distribution patterns within various structures of the umbilical cord, among which Wharton's jelly is especially collagen-rich tissue. Cathepsin L is a potent cysteine protease engaged in degradation of extracellular matrix proteins, including collagens. We evaluated the activity and expression of cathepsin L, and the inhibitory effect of cysteine protease inhibitors in the umbilical cord arteries, vein and Wharton's jelly. Cathepsin L activity and anti-papain inhibitory effect of cysteine protease inhibitors were quantified in extracts of separated umbilical cord tissues using fluorogenic substrates. The results were calculated per DNA content. The enzyme expression was assessed by Western immunoblotting. The active cathepsin L activity (without activation by pepsin digestion), its percentage in the total activity (after pepsin activation), and the expression of the mature single-chain enzyme were the lowest in the umbilical cord arteries and the highest in Wharton's jelly. The effect of cysteine protease inhibitors showed similar distribution as in the case of the active enzyme, being the highest in Wharton's jelly. Distribution of the activity and expression of mature cathepsin L within the umbilical cord probably results from distinctions in the proenzyme activation process. Differences in the action of cysteine protease inhibitors can partly restrict divergences in the enzyme activity that could reflect its expression alone. Differential enzyme action seems to contribute to tissue-specific collagen turnover within the umbilical cord cells, especially those of Wharton's jelly.

  7. Protective effects of positive lysosomal modulation in Alzheimer's disease transgenic mouse models.

    Directory of Open Access Journals (Sweden)

    David Butler

    Full Text Available Alzheimer's disease (AD is an age-related neurodegenerative pathology in which defects in proteolytic clearance of amyloid β peptide (Aβ likely contribute to the progressive nature of the disorder. Lysosomal proteases of the cathepsin family exhibit up-regulation in response to accumulating proteins including Aβ(1-42. Here, the lysosomal modulator Z-Phe-Ala-diazomethylketone (PADK was used to test whether proteolytic activity can be enhanced to reduce the accumulation events in AD mouse models expressing different levels of Aβ pathology. Systemic PADK injections in APP(SwInd and APPswe/PS1ΔE9 mice caused 3- to 8-fold increases in cathepsin B protein levels and 3- to 10-fold increases in the enzyme's activity in lysosomal fractions, while neprilysin and insulin-degrading enzyme remained unchanged. Biochemical analyses indicated the modulation predominantly targeted the active mature forms of cathepsin B and markedly changed Rab proteins but not LAMP1, suggesting the involvement of enhanced trafficking. The modulated lysosomal system led to reductions in both Aβ immunostaining as well as Aβ(x-42 sandwich ELISA measures in APP(SwInd mice of 10-11 months. More extensive Aβ deposition in 20-22-month APPswe/PS1ΔE9 mice was also reduced by PADK. Selective ELISAs found that a corresponding production of the less pathogenic Aβ(1-38 occurs as Aβ(1-42 levels decrease in the mouse models, indicating that PADK treatment leads to Aβ truncation. Associated with Aβ clearance was the elimination of behavioral and synaptic protein deficits evident in the two transgenic models. These findings indicate that pharmacologically-controlled lysosomal modulation reduces Aβ(1-42 accumulation, possibly through intracellular truncation that also influences extracellular deposition, and in turn offsets the defects in synaptic composition and cognitive functions. The selective modulation promotes clearance at different levels of Aβ pathology and provides proof

  8. Protective effects of positive lysosomal modulation in Alzheimer's disease transgenic mouse models.

    Science.gov (United States)

    Butler, David; Hwang, Jeannie; Estick, Candice; Nishiyama, Akiko; Kumar, Saranya Santhosh; Baveghems, Clive; Young-Oxendine, Hollie B; Wisniewski, Meagan L; Charalambides, Ana; Bahr, Ben A

    2011-01-01

    Alzheimer's disease (AD) is an age-related neurodegenerative pathology in which defects in proteolytic clearance of amyloid β peptide (Aβ) likely contribute to the progressive nature of the disorder. Lysosomal proteases of the cathepsin family exhibit up-regulation in response to accumulating proteins including Aβ(1-42). Here, the lysosomal modulator Z-Phe-Ala-diazomethylketone (PADK) was used to test whether proteolytic activity can be enhanced to reduce the accumulation events in AD mouse models expressing different levels of Aβ pathology. Systemic PADK injections in APP(SwInd) and APPswe/PS1ΔE9 mice caused 3- to 8-fold increases in cathepsin B protein levels and 3- to 10-fold increases in the enzyme's activity in lysosomal fractions, while neprilysin and insulin-degrading enzyme remained unchanged. Biochemical analyses indicated the modulation predominantly targeted the active mature forms of cathepsin B and markedly changed Rab proteins but not LAMP1, suggesting the involvement of enhanced trafficking. The modulated lysosomal system led to reductions in both Aβ immunostaining as well as Aβ(x-42) sandwich ELISA measures in APP(SwInd) mice of 10-11 months. More extensive Aβ deposition in 20-22-month APPswe/PS1ΔE9 mice was also reduced by PADK. Selective ELISAs found that a corresponding production of the less pathogenic Aβ(1-38) occurs as Aβ(1-42) levels decrease in the mouse models, indicating that PADK treatment leads to Aβ truncation. Associated with Aβ clearance was the elimination of behavioral and synaptic protein deficits evident in the two transgenic models. These findings indicate that pharmacologically-controlled lysosomal modulation reduces Aβ(1-42) accumulation, possibly through intracellular truncation that also influences extracellular deposition, and in turn offsets the defects in synaptic composition and cognitive functions. The selective modulation promotes clearance at different levels of Aβ pathology and provides proof

  9. Cysteine cathepsin activity suppresses osteoclastogenesis of myeloid-derived suppressor cells in breast cancer.

    Science.gov (United States)

    Edgington-Mitchell, Laura E; Rautela, Jai; Duivenvoorden, Hendrika M; Jayatilleke, Krishnath M; van der Linden, Wouter A; Verdoes, Martijn; Bogyo, Matthew; Parker, Belinda S

    2015-09-29

    Cysteine cathepsin proteases contribute to many normal cellular functions, and their aberrant activity within various cell types can contribute to many diseases, including breast cancer. It is now well accepted that cathepsin proteases have numerous cell-specific functions within the tumor microenvironment that function to promote tumor growth and invasion, such that they may be valid targets for anti-metastatic therapeutic approaches. Using activity-based probes, we have examined the activity and expression of cysteine cathepsins in a mouse model of breast cancer metastasis to bone. In mice bearing highly metastatic tumors, we detected abundant cysteine cathepsin expression and activity in myeloid-derived suppressor cells (MDSCs). These immature immune cells have known metastasis-promoting roles, including immunosuppression and osteoclastogenesis, and we assessed the contribution of cysteine cathepsins to these functions. Blocking cysteine cathepsin activity with multiple small-molecule inhibitors resulted in enhanced differentiation of multinucleated osteoclasts. This highlights a potential role for cysteine cathepsin activity in suppressing the fusion of osteoclast precursor cells. In support of this hypothesis, we found that expression and activity of key cysteine cathepsins were downregulated during MDSC-osteoclast differentiation. Another cysteine protease, legumain, also inhibits osteoclastogenesis, in part through modulation of cathepsin L activity. Together, these data suggest that cysteine protease inhibition is associated with enhanced osteoclastogenesis, a process that has been implicated in bone metastasis.

  10. Glycopeptide Antibiotics Potently Inhibit Cathepsin L in the Late Endosome/Lysosome and Block the Entry of Ebola Virus, Middle East Respiratory Syndrome Coronavirus (MERS-CoV), and Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV).

    Science.gov (United States)

    Zhou, Nan; Pan, Ting; Zhang, Junsong; Li, Qianwen; Zhang, Xue; Bai, Chuan; Huang, Feng; Peng, Tao; Zhang, Jianhua; Liu, Chao; Tao, Liang; Zhang, Hui

    2016-04-22

    Ebola virus infection can cause severe hemorrhagic fever with a high mortality in humans. The outbreaks of Ebola viruses in 2014 represented the most serious Ebola epidemics in history and greatly threatened public health worldwide. The development of additional effective anti-Ebola therapeutic agents is therefore quite urgent. In this study, via high throughput screening of Food and Drug Administration-approved drugs, we identified that teicoplanin, a glycopeptide antibiotic, potently prevents the entry of Ebola envelope pseudotyped viruses into the cytoplasm. Furthermore, teicoplanin also has an inhibitory effect on transcription- and replication-competent virus-like particles, with an IC50 as low as 330 nm Comparative analysis further demonstrated that teicoplanin is able to block the entry of Middle East respiratory syndrome (MERS) and severe acute respiratory syndrome (SARS) envelope pseudotyped viruses as well. Teicoplanin derivatives such as dalbavancin, oritavancin, and telavancin can also inhibit the entry of Ebola, MERS, and SARS viruses. Mechanistic studies showed that teicoplanin blocks Ebola virus entry by specifically inhibiting the activity of cathepsin L, opening a novel avenue for the development of additional glycopeptides as potential inhibitors of cathepsin L-dependent viruses. Notably, given that teicoplanin has routinely been used in the clinic with low toxicity, our work provides a promising prospect for the prophylaxis and treatment of Ebola, MERS, and SARS virus infection.

  11. Role of cathepsins in blastocyst hatching in the golden hamster.

    Science.gov (United States)

    Sireesha, G V; Mason, R W; Hassanein, M; Tonack, S; Navarrete Santos, A; Fischer, B; Seshagiri, P B

    2008-06-01

    The mammalian embryo is encased in a glycoproteinaceous coat, the zona pellucida (ZP) during preimplantation development. Prior to implantation, the blastocyst must undergo 'hatching' or ZP escape. In hamsters, there is a thinning of the ZP followed by a focal lysis and a complete dissolution of the ZP during blastocyst hatching. Earlier studies from our laboratory have indicated a role for cysteine proteases in the hatching phenomenon. In this study, we tested the effect of specific inhibitors of the three classes of cysteine protease on blastocyst hatching. Cystatin, an endogenous cathepsin inhibitor, blocked blastocyst hatching. Similarly, Fmoc-Tyr-Ala-diazomethane, a synthetic cathepsin inhibitor, blocked hatching. Both showed dose-dependent and temporal inhibition of hatching. However, Z-Val-Ala-Asp-fluoromethylketone, a synthetic caspase inhibitor, and calpastatin, an endogenous calpain inhibitor, had no effect on hatching. The cathepsins were localized to blastocyst cells. Exogenous addition of cathepsins L, P or B to cultured 8-cell embryos caused a complete ZP dissolution. The expression of mRNA and protein of cathepsins L and P was observed in peri-hatching blastocysts. Cathepsins L and P were detected in trophectodermal projections and in the ZP of peri-hatching blastocysts. These data provide the first evidence that blastocyst-derived cathepsins are functionally involved as zonalytic factors in the hatching of blastocysts in the golden hamster.

  12. Endosomal acidification and cathepsin L activity is required for calicivirus replication.

    Science.gov (United States)

    Shivanna, Vinay; Kim, Yunjeong; Chang, Kyeong-Ok

    2014-09-01

    The role of cellular proteases and endosome maturation in the entry of caliciviruses including porcine enteric calicivirus (PEC), murine norovirus (MNV)-1 and feline calicivirus (FCV) were investigated. Treatment with chloroquine or cathepsin L inhibitors, but not cathepsin B inhibitors, significantly reduced the replication of PEC, MNV and FCV. When concentrated PEC, MNV or FCV were incubated with recombinant cathepsin L, the minor capsid protein VP2 of PEC and the major capsid protein VP1 of MNV and FCV were cleaved by the protease based on the Western blot analysis. Confocal microscopy analysis of PEC and MNV-1 showed that viral capsid proteins were retained in the endosomes in the presence of a cathepsin L inhibitor or chloroquine during virus entry. The results of this study suggest the important role of endosome maturation and cathepsin L in the entry of caliciviruses, and cathepsin L as a potential therapeutic target for calicivirus infection. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Caught in the act: the crystal structure of cleaved cathepsin L bound to the active site of Cathepsin L.

    Science.gov (United States)

    Sosnowski, Piotr; Turk, Dušan

    2016-04-01

    Cathepsin L is a ubiquitously expressed papain-like cysteine protease involved in the endosomal degradation of proteins and has numerous roles in physiological and pathological processes, such as arthritis, osteoporosis, and cancer. Insight into the specificity of cathepsin L is important for elucidating its physiological roles and drug discovery. To study interactions with synthetic ligands, we prepared a presumably inactive mutant and crystallized it. Unexpectedly, the crystal structure determined at 1.4 Å revealed that the cathepsin L molecule is cleaved, with the cleaved region trapped in the active site cleft of the neighboring molecule. Hence, the catalytic mutant demonstrated low levels of catalytic activity.

  14. Progress on Action of Cathepsin K in Bone Resorption%组织蛋白酶K在骨吸收中的作用研究进展

    Institute of Scientific and Technical Information of China (English)

    王东; 顾建红; 刘宗平

    2014-01-01

    组织蛋白酶 K(Cathepsin K,CK)是一种溶酶体半胱氨酸蛋白酶,属于番木瓜蛋白酶超家族。在破骨细胞(osteoclast,OC)介导的骨吸收过程中有效降解骨组织中的基质蛋白,在骨吸收过程中发挥重要作用。研究 CK 在骨吸收中的重要性,为治疗骨代谢疾病开辟了新的途径。论文就组织蛋白酶 K 的结构和功能及在骨吸收过程中与破骨细胞的相互作用和表达水平的调控机制进行了阐述。%Cathepsin K is one of lysosomal cysteine proteases,belongs to the papaya protease superfamily,highly expressed in the process of bone resorption mediated by osteoclasts and degrade matrix proteins in bone tissue ef-fectively,plays a significant role in the process on bone resorption.Study of the importance of cathepsin k in bone resorption opened up a new approach to metabolic bone disease treatment.In this mini-review,we mainly focused on the structure and function of cathepsin K and the interaction with osteoclast,the regulation mechanisms of ex-pression levels in the process of bone resorption.

  15. Effect of SI-591, a new class of cathepsin K inhibitor with peptidomimetic structure, on bone metabolism in vitro and in vivo.

    Science.gov (United States)

    Fujii, Toshiaki; Ishikawa, Mizuho; Kubo, Akiko; Tanaka, Yoshitaka

    2015-12-01

    SI-591[N-[1-[[[(1S)-3-[[(3S)-hexahydro-2-oxo-1H-azepin-3-yl]amino]-1-(1-methylethyl)-2,3-dioxopropyl]amino]carbonyl]cyclohexyl]-2-furancarboxamide] is an orally bioavailable compound that was synthesized as one of several unique peptidomimetic compounds without a basic group. This compound was found to have the ability to inhibit cathepsin K, a lysosomal cysteine protease. Cathepsin K is known to be expressed in osteoclasts and involved in bone loss processes. In this study, SI-591 was shown to inhibit the activity of various purified cathepsin molecules at nanomolar concentrations but had high selectivity for cathepsin K over other subtypes including B and L. SI-591 also decreased the level of CTX-I, a bone resorption marker, which was released from osteoclasts in vitro in a dose-dependent manner. The mobilization of calcium from the bones to the blood stream is known to increase in rats fed with a low calcium diet; SI-591 inhibited this increase in serum calcium level at an oral dose of 3mg/kg. Furthermore, SI-591 significantly decreased the level of CTX-I and DPD, bone resorption markers, at oral doses of 10mg/kg or less in ovariectomized rats, while it did not affect the level of BGP, a bone formation marker. In addition, SI-591 prevented bone mineral density loss in the lumber vertebrae and femurs in ovariectomized rats. These results suggest that SI-591 inhibits bone resorption without affecting osteoblast maturation. Therefore, SI-591, a novel cathepsin K inhibitor, could be a promising agent for the treatment of postmenopausal osteoporosis.

  16. 15-Deoxy-Delta(12,14)-prostaglandin-J(2) reveals a new pVHL-independent, lysosomal-dependent mechanism of HIF-1alpha degradation.

    Science.gov (United States)

    Olmos, Gemma; Arenas, María I; Bienes, Raquel; Calzada, María Jose; Aragonés, Julián; Garcia-Bermejo, Maria Laura; Landazuri, Manuel O; Lucio-Cazaña, Javier

    2009-07-01

    Hypoxia-inducible factor-1alpha (HIF-1alpha) protein is degraded under normoxia by its association to von Hippel-Lindau protein (pVHL) and further proteasomal digestion. However, human renal cells HK-2 treated with 15-deoxy-Delta(12,14)-prostaglandin-J(2) (15d-PGJ(2)) accumulate HIF-1alpha in normoxic conditions. Thus, we aimed to investigate the mechanism involved in this accumulation. We found that 15d-PGJ(2) induced an over-accumulation of HIF-1alpha in RCC4 cells, which lack pVHL and in HK-2 cells treated with inhibitors of the pVHL-proteasome pathway. These results indicated that pVHL-proteasome-independent mechanisms are involved, and therefore we aimed to ascertain them. We have identified a new lysosomal-dependent mechanism of HIF-1alpha degradation as a target for 15d-PGJ(2) based on: (1) HIF-1alpha colocalized with the specific lysosomal marker Lamp-2a, (2) 15d-PGJ(2) inhibited the activity of cathepsin B, a lysosomal protease, and (3) inhibition of lysosomal activity did not result in over-accumulation of HIF-1alpha in 15d-PGJ(2)-treated cells. Therefore, expression of HIF-1alpha is also modulated by lysosomal degradation.

  17. Molecular cloning and characterization of cathepsin B from the hepatopancreas of northern shrimp Pandalus borealis.

    Science.gov (United States)

    Aoki, Hitoshi; Ahsan, Md Nazmul; Watabe, Shugo

    2003-04-01

    We cloned a cDNA encoding cathepsin B from the hepatopancreas of northern shrimp Pandalus borealis (NsCtB). Nucleotide sequence of the isolated clone encoded a preproenzyme of 328 amino acids, comprising a 15-residue putative signal peptide, a 60-residue propeptide and the 253-residue mature enzyme. The mature NsCtB was 53% identical to human cathepsin B and conserved all the structural features characteristic of cysteine protease. The presence of an occluding loop in the mature region, a unique feature of cathepsin B, suggested the shrimp protein to be cathepsin B. Northern blot analysis revealed expression of NsCtB transcripts exclusively in the hepatopancreas tissues, suggesting a possible digestive role of this enzyme. An interesting feature of NsCtB was its remarkably high negative charge in comparison with other cysteine proteases, which was predicted to effectively locate and guide the positively charged residues of a substrate into the binding cleft. We also observed a repertoire of cysteine protease activities in the acidic milieu of shrimp hepatopancreas using synthetic substrates specific to various cathepsins. The activity profile revealed cathepsin B as the single most dominant enzyme with a specific activity comparable to that attributable to combined activities of other cathepsins. This activity could be blocked by E-64, a cysteine protease inhibitor, but not by Z-Phe-Tyr (t-Bu)-CHN(2), a specific inhibitor of cathepsin L.

  18. The Coordinated Action of Calcineurin and Cathepsin D Protects Against α-Synuclein Toxicity

    Directory of Open Access Journals (Sweden)

    Andreas Aufschnaiter

    2017-06-01

    Full Text Available The degeneration of dopaminergic neurons during Parkinson’s disease (PD is intimately linked to malfunction of α-synuclein (αSyn, the main component of the proteinaceous intracellular inclusions characteristic for this pathology. The cytotoxicity of αSyn has been attributed to disturbances in several biological processes conserved from yeast to humans, including Ca2+ homeostasis, general lysosomal function and autophagy. However, the precise sequence of events that eventually results in cell death remains unclear. Here, we establish a connection between the major lysosomal protease cathepsin D (CatD and the Ca2+/calmodulin-dependent phosphatase calcineurin. In a yeast model for PD, high levels of human αSyn triggered cytosolic acidification and reduced vacuolar hydrolytic capacity, finally leading to cell death. This could be counteracted by overexpression of yeast CatD (Pep4, which re-installed pH homeostasis and vacuolar proteolytic function, decreased αSyn oligomers and aggregates, and provided cytoprotection. Interestingly, these beneficial effects of Pep4 were independent of autophagy. Instead, they required functional calcineurin signaling, since deletion of calcineurin strongly reduced both the proteolytic activity of endogenous Pep4 and the cytoprotective capacity of overexpressed Pep4. Calcineurin contributed to proper endosomal targeting of Pep4 to the vacuole and the recycling of the Pep4 sorting receptor Pep1 from prevacuolar compartments back to the trans-Golgi network. Altogether, we demonstrate that stimulation of this novel calcineurin-Pep4 axis reduces αSyn cytotoxicity.

  19. A Novel High Content Imaging-Based Screen Identifies the Anti-Helminthic Niclosamide as an Inhibitor of Lysosome Anterograde Trafficking and Prostate Cancer Cell Invasion.

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    Magdalena L Circu

    Full Text Available Lysosome trafficking plays a significant role in tumor invasion, a key event for the development of metastasis. Previous studies from our laboratory have demonstrated that the anterograde (outward movement of lysosomes to the cell surface in response to certain tumor microenvironment stimulus, such as hepatocyte growth factor (HGF or acidic extracellular pH (pHe, increases cathepsin B secretion and tumor cell invasion. Anterograde lysosome trafficking depends on sodium-proton exchanger activity and can be reversed by blocking these ion pumps with Troglitazone or EIPA. Since these drugs cannot be advanced into the clinic due to toxicity, we have designed a high-content assay to discover drugs that block peripheral lysosome trafficking with the goal of identifying novel drugs that inhibit tumor cell invasion. An automated high-content imaging system (Cellomics was used to measure the position of lysosomes relative to the nucleus. Among a total of 2210 repurposed and natural product drugs screened, 18 "hits" were identified. One of the compounds identified as an anterograde lysosome trafficking inhibitor was niclosamide, a marketed human anti-helminthic drug. Further studies revealed that niclosamide blocked acidic pHe, HGF, and epidermal growth factor (EGF-induced anterograde lysosome redistribution, protease secretion, motility, and invasion of DU145 castrate resistant prostate cancer cells at clinically relevant concentrations. In an effort to identify the mechanism by which niclosamide prevented anterograde lysosome movement, we found that this drug exhibited no significant effect on the level of ATP, microtubules or actin filaments, and had minimal effect on the PI3K and MAPK pathways. Niclosamide collapsed intralysosomal pH without disruption of the lysosome membrane, while bafilomycin, an agent that impairs lysosome acidification, was also found to induce JLA in our model. Taken together, these data suggest that niclosamide promotes

  20. Cysteine cathepsin activity suppresses osteoclastogenesis of myeloid-derived suppressor cells in breast cancer

    OpenAIRE

    Edgington-Mitchell, Laura E.; Rautela, Jai; Duivenvoorden, Hendrika M.; Jayatilleke, Krishnath M.; Wouter A. van der Linden; Verdoes, Martijn; Bogyo, Matthew; Parker, Belinda S.

    2015-01-01

    Cysteine cathepsin proteases contribute to many normal cellular functions, and their aberrant activity within various cell types can contribute to many diseases, including breast cancer. It is now well accepted that cathepsin proteases have numerous cell-specific functions within the tumor microenvironment that function to promote tumor growth and invasion, such that they may be valid targets for anti-metastatic therapeutic approaches. Using activity-based probes, we have examined the activit...

  1. A bioavailable cathepsin S nitrile inhibitor abrogates tumor development.

    Science.gov (United States)

    Wilkinson, Richard D A; Young, Andrew; Burden, Roberta E; Williams, Rich; Scott, Christopher J

    2016-04-21

    Cathepsin S has been implicated in a variety of malignancies with genetic ablation studies demonstrating a key role in tumor invasion and neo-angiogenesis. Thus, the application of cathepsin S inhibitors may have clinical utility in the treatment of cancer. In this investigation, we applied a cell-permeable dipeptidyl nitrile inhibitor of cathepsin S, originally developed to target cathepsin S in inflammatory diseases, in both in vitro and in vivo tumor models. Validation of cathepsin S selectivity was carried out by assaying fluorogenic substrate turnover using recombinant cathepsin protease. Complete kinetic analysis was carried out and true K i values calculated. Abrogation of tumour invasion using murine MC38 and human MCF7 cell lines were carried out in vitro using a transwell migration assay. Effect on endothelial tube formation was evaluated using primary HUVEC cells. The effect of inhibitor in vivo on MC38 and MCF7 tumor progression was evaluated using cells propagated in C57BL/6 and BALB/c mice respectively. Subsequent immunohistochemical staining of proliferation (Ki67) and apoptosis (TUNEL) was carried out on MCF7 tumors. We confirmed that this inhibitor was able to selectively target cathepsin S over family members K, V, L and B. The inhibitor also significantly reduced MC38 and MCF7 cell invasion and furthermore, significantly reduced HUVEC endothelial tubule formation in vitro. In vivo analysis revealed that the compound could significantly reduce tumor volume in murine MC38 syngeneic and MCF7 xenograft models. Immunohistochemical analysis of MCF7 tumors revealed cathepsin S inhibitor treatment significantly reduced proliferation and increased apoptosis. In summary, these results highlight the characterisation of this nitrile cathepsin S inhibitor using in vitro and in vivo tumor models, presenting a compound which may be used to further dissect the role of cathepsin S in cancer progression and may hold therapeutic potential.

  2. Bone Microenvironment Modulates Expression and Activity of Cathepsin B in Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Izabela Podgorski

    2005-03-01

    Full Text Available Prostate cancers metastasize to bone leading to osteolysis. Here we assessed proteolysis of DOcollagen I (a bone matrix protein and, for comparison, DO-collagen IV, by living human prostate carcinoma cells in vitro. Both collagens were degraded, this degradation was reduced by inhibitors of matrix metallo, serine, cysteine proteases. Because secretion of the cysteine protease cathepsin B is increased in human breast fibroblasts grown on collagen I gels, we analyzed cathepsin B levels and secretion in prostate cells grown on collagen I gels. Levels and secretion were increased only in DU145 cells-cells that expressed the highest baseline levels of cathepsin B. Secretion of cathepsin B was also elevated in DU145 cells grown in vitro on human bone fragments. We further investigated the effect of the bone microenvironment on cathepsin B expression and activity in vivo in a SCID-human model of prostate bone metastasis. High levels of cathepsin B protein and activity were found in DU145, PC3, LNCaP bone tumors, although the PC3 and LNCaP cells had exhibited low cathepsin B expression in vitro. Our results suggest that tumor-stromal interactions in the context of the bone microenvironment can modulate the expression of the cysteine protease cathepsin B.

  3. Human sputum cathepsin B degrades proteoglycan, is inhibited by alpha 2-macroglobulin and is modulated by neutrophil elastase cleavage of cathepsin B precursor and cystatin C.

    Science.gov (United States)

    Buttle, D J; Abrahamson, M; Burnett, D; Mort, J S; Barrett, A J; Dando, P M; Hill, S L

    1991-01-01

    The high-Mr alkali-stable form of cathepsin B was purified from purulent human sputum. It was shown to solubilize proteoglycan monomer entrapped in polyacrylamide at a rate comparable with that of human lysosomal cathepsin B. Like the enzyme from lysosomes, sputum cathepsin B was bound by human alpha 2-macroglobulin, which inhibited its action on proteoglycan. Cystatin C in purulent sputum was shown to be the N-terminally truncated form generated by neutrophil elastase cleavage, and sputum cathepsin B was only weakly inhibited by recombinant cystatin C that had been cleaved by neutrophil elastase in vitro. Addition of neutrophil elastase to mucoid sputum led to a 5-fold increase in cathepsin B activity concomitant with a lowering in Mr of the cysteine proteinase from 40,000 to 37,000, i.e. the size of the active enzyme purified from purulent sputum. It is concluded that the high-Mr form of cathepsin B present in purulent sputum is a functional proteinase, unlike similar forms of the enzyme secreted by mammary gland in organ culture. The activity of cathepsin B in sputum is modulated by neutrophil elastase, by a combination of inhibitor inactivation and zymogen activation. Images Fig. 3. Fig. 4. Fig. 5. PMID:1710889

  4. Cathepsin B-dependent motor neuron death after nerve injury in the adult mouse

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Li; Wu, Zhou; Baba, Masashi [Department of Aging Science and Pharmacology, Faculty of Dental Sciences, Kyushu University, Maidashi 3-1-1, Fukuoka 812-8582 (Japan); Peters, Christoph [Institute fuer Molekulare Medizin und Zellforshung, Albert-Ludwings-Universitaet Freiburg, D-79104 Freiburg (Germany); Uchiyama, Yasuo [Department of Cell Biology and Neuroscience, Juntendo University Graduate School of Medicine, Tokyo (Japan); Nakanishi, Hiroshi, E-mail: nakan@dent.kyushu-u.ac.jp [Department of Aging Science and Pharmacology, Faculty of Dental Sciences, Kyushu University, Maidashi 3-1-1, Fukuoka 812-8582 (Japan)

    2010-08-27

    Research highlights: {yields} Cathepsin B (CB), a lysosomal cysteine protease, is expressed in neuron and glia. {yields} CB increased in hypogrossal nucleus neurons after nerve injury in adult mice. {yields} CB-deficiency significantly increased the mean survival ratio of injured neurons. {yields} Thus, CB plays a critical role in axotomy-induced neuronal death in adult mice. -- Abstract: There are significant differences in the rate of neuronal death after peripheral nerve injury between species. The rate of neuronal death of motor neurons after nerve injury in the adult rats is very low, whereas that in adult mice is relatively high. However, the understanding of the mechanism underlying axotomy-induced motor neuron death in adult mice is limited. Cathepsin B (CB), a typical cysteine lysosomal protease, has been implicated in three major morphologically distinct pathways of cell death; apoptosis, necrosis and autophagic cell death. The possible involvement of CB in the neuronal death of hypogrossal nucleus (HGN) neurons after nerve injury in adult mice was thus examined. Quantitative analyses showed the mean survival ratio of HGN neurons in CB-deficient (CB-/-) adult mice after nerve injury was significantly greater than that in the wild-type mice. At the same time, proliferation of microglia in the injured side of the HGN of CB-/- adult mice was markedly reduced compared with that in the wild-type mice. On the injured side of the HGN in the wild-type adult mice, both pro- and mature forms of CB markedly increased in accordance with the increase in the membrane-bound form of LC3 (LC3-II), a marker protein of autophagy. Furthermore, the increase in CB preceded an increase in the expression of Noxa, a major executor for axotomy-induced motor neuron death in the adult mouse. Conversely, expression of neither Noxa or LC3-II was observed in the HGN of adult CB-/- mice after nerve injury. These observations strongly suggest that CB plays a critical role in axotomy

  5. Mining a cathepsin inhibitor library for new antiparasitic drug leads.

    Directory of Open Access Journals (Sweden)

    Kenny K H Ang

    Full Text Available The targeting of parasite cysteine proteases with small molecules is emerging as a possible approach to treat tropical parasitic diseases such as sleeping sickness, Chagas' disease, and malaria. The homology of parasite cysteine proteases to the human cathepsins suggests that inhibitors originally developed for the latter may be a source of promising lead compounds for the former. We describe here the screening of a unique ∼ 2,100-member cathepsin inhibitor library against five parasite cysteine proteases thought to be relevant in tropical parasitic diseases. Compounds active against parasite enzymes were subsequently screened against cultured Plasmodium falciparum, Trypanosoma brucei brucei and/or Trypanosoma cruzi parasites and evaluated for cytotoxicity to mammalian cells. The end products of this effort include the identification of sub-micromolar cell-active leads as well as the elucidation of structure-activity trends that can guide further optimization efforts.

  6. Cloning of a cDNA encoding cathepsin D from salamander, Hynobius leechii, and its expression in the limb regenerates.

    Science.gov (United States)

    Ju, B G; Kim, W S

    2000-01-01

    Cathepsin D is a major lysosomal aspartic proteinase participating in the degradation or modification of intra- and extracellular matrix molecules, and its activity is known to increase in the process of tissue reorganization during the early phase of salamander limb regeneration. Here, we report the cloning of a salamander cathepsin D cDNA from Hynobius leechii and its expression profile in normal and retinoic acid (RA) treated limb regenerates. The gene expression of cathepsin D increased notably during the dedifferentiation stage and decreased gradually thereafter. Furthermore, RA that enhances dedifferentiation of regenerating salamander limb caused the elevation of cathepsin D expression both in terms of level and duration. These results suggest that cathepsin D plays important role(s) in the dedifferentiation process, and enhancement of cathepsin D expression might be closely related to RA-evoked pattern duplication.

  7. Myocardial Upregulation of Cathepsin D by Ischemic Heart Disease Promotes Autophagic Flux and Protects Against Cardiac Remodeling and Heart Failure.

    Science.gov (United States)

    Wu, Penglong; Yuan, Xun; Li, Faqian; Zhang, Jianhua; Zhu, Wei; Wei, Meng; Li, Jingbo; Wang, Xuejun

    2017-07-01

    Lysosomal dysfunction is implicated in human heart failure for which ischemic heart disease is the leading cause. Altered myocardial expression of CTSD (cathepsin D), a major lysosomal protease, was observed in human heart failure, but its pathophysiological significance has not been determined. Western blot analyses revealed an increase in the precursor but not the mature form of CTSD in myocardial samples from explanted human failing hearts with ischemic heart disease, which is recapitulated in chronic myocardial infarction produced via coronary artery ligation in Ctsd(+/+) but not Ctsd(+/-) mice. Mice deficient of Ctsd displayed impaired myocardial autophagosome removal, reduced autophagic flux, and restrictive cardiomyopathy. After induction of myocardial infarction, weekly serial echocardiography detected earlier occurrence of left ventricle chamber dilatation, greater decreases in ejection fraction and fractional shortening, and lesser wall thickening throughout the first 4 weeks; pressure-volume relationship analyses at 4 weeks revealed greater decreases in systolic and diastolic functions, stroke work, stroke volume, and cardiac output; greater increases in the ventricular weight to body weight and the lung weight to body weight ratios and larger scar size were also detected in Ctsd(+/-) mice compared with Ctsd(+/+) mice. Significant increases of myocardial autophagic flux detected at 1 and 4 weeks after induction of myocardial infarction in the Ctsd(+/+) mice were diminished in the Ctsd(+/-) mice. Myocardial CTSD upregulation induced by myocardial infarction protects against cardiac remodeling and malfunction, which is at least in part through promoting myocardial autophagic flux. © 2017 American Heart Association, Inc.

  8. Role of Myeloperoxidase Oxidants in the Modulation of Cellular Lysosomal Enzyme Function

    DEFF Research Database (Denmark)

    Ismael, Fahd O; Barrett, Tessa J; Sheipouri, Diba

    2016-01-01

    with the development of atherosclerosis. In this study, we examined the effect of HOCl, HOSCN and LDL pre-treated with these oxidants on the function of lysosomal enzymes responsible for protein catabolism and lipid hydrolysis in murine macrophage-like J774A.1 cells. In each case, the cells were exposed to HOCl...... or HOSCN or LDL pre-treated with these oxidants. Lysosomal cathepsin (B, L and D) and acid lipase activities were quantified, with cathepsin and LAMP-1 protein levels determined by Western blotting. Exposure of J774A.1 cells to HOCl or HOSCN resulted in a significant decrease in the activity of the Cys......-dependent cathepsins B and L, but not the Asp-dependent cathepsin D. Cathepsins B and L were also inhibited in macrophages exposed to HOSCN-modified, and to a lesser extent, HOCl-modified LDL. No change was seen in cathepsin D activity or the expression of the cathepsin proteins or lysosomal marker protein LAMP-1...

  9. Identification of cathepsin K as a novel marker of adiposity in white adipose tissue.

    Science.gov (United States)

    Chiellini, Chiara; Costa, Mario; Novelli, Silvia E; Amri, Ez-Zoubir; Benzi, Luca; Bertacca, Anna; Cohen, Paul; Del Prato, Stefano; Friedman, Jeffrey M; Maffei, Margherita

    2003-05-01

    In obesity, adipocytes undergo dramatic morphological and molecular changes associated with alterations in their gene expression profile. To identify genes differentially modulated in white adipose tissue (WAT) of obese db/db mice compared to wild type (wt) mice, we utilized RNA fingerprinting. Among the 52 candidates that we identified, we focused here on cathepsin K (ctsk), a cysteine protease, prevalently localized in lysosomes and involved in bone extracellular matrix degradation. In db/db mice, WAT ctsk mRNA was elevated 5.9-fold, as were Mitf and TFE3 (2- and 3.3-fold respectively), two transcription factors involved in ctsk induction in osteoclasts. Moreover, the level of WAT ctsk mRNA was increased in other obese models including A(y), fat, and tubby (2.8-, 3.2-, and 4.9-fold respectively) and decreased in mice undergoing weight loss. Despite the ubiquitous distribution of the ctsk transcript, we demonstrated that the obesity related increase is specific to the adipocytes. Further, in vitro experiments proved that the abundance of ctsk transcript increases upon adipose conversion of the established cell line of preadipocytes 3T3-F442A. In addition, ctsk gene expression was examined in adipose tissue of 21 lean and obese male subjects and significant correlations with BMI (r = 0.54, P = 0.012) and plasma leptin levels (r = 0.54, P = 0.015) were found. In conclusion, the WAT of obese db/db mice exhibits a different expression profile from that of the wt mice, and cathepsin K can be considered a novel marker of obesity and a target for the inhibition of adipose mass growth.

  10. Changes of cathepsin B in human photoaging skin both in vivo and in vitro

    Institute of Scientific and Technical Information of China (English)

    LAI Wei; ZHENG Yue; YE Zhang-zhang; SU Xiang-yang; WAN Miao-jian; GONG Zi-jian; XIE Xiao-yuan; LIU Wei

    2010-01-01

    Background Cathepsin B plays an important role in cell cycle, extracellular matrix changes and cutaneous tumorigenesis: whether it plays a role in photoaged skin remains unknown. This study aimed to investigate the role of cathepsin B in skin photoaging in vivo and in vitro. Methods The expressions of cathepsin B were compared with immunohistochemical methods in solar exposed skin and solar protected skin of six healthy Chinese volunteers. The mRNA and protein expression of cathepsin B in ultraviolet light A (UVA) induced premature senescence fibroblasts in vitro were detected by real-time reverse transcription polymerase chain reaction (RT-PCR) and Western blotting technique. Results Decreased expression of cathepsin B was observed in photoaged skin compared with that of the solar protected skin. In the UVA induced, premature senescence fibroblasts, a lower expression of cathepsin B was detected by Western blotting and a decreased synthesis of cathepsin B mRNA in the same cells was revealed by real-time RT-PCR. Conclusions The results demonstrated a significant negative correlation between skin photoaging and cathepsin B in vitro and in vivo. We propose that cathepsin B, besides matrix metalloproteinases and antioxidant enzymes, is involved in the process of skin photoaging in that it contributes to extracellular matrix remodelling and is a dominant protease in cellular apoptosis and senescence.

  11. Extracellular proteolysis of apolipoprotein E (apoE by secreted serine neuronal protease.

    Directory of Open Access Journals (Sweden)

    Irfan Y Tamboli

    Full Text Available Under normal conditions, brain apolipoprotein E (apoE is secreted and lipidated by astrocytes, then taken up by neurons via receptor mediated endocytosis. Free apoE is either degraded in intraneuronal lysosomal compartments or released. Here we identified a novel way by which apoE undergoes proteolysis in the extracellular space via a secreted neuronal protease. We show that apoE is cleaved in neuronal conditioned media by a secreted serine protease. This apoE cleavage was inhibited by PMSF and α1-antichymotrypsin, but not neuroserpin-1 or inhibitors of thrombin and cathepsin G, supporting its identity as a chymotrypsin like protease. In addition, apoE incubation with purified chymotrypsin produced a similar pattern of apoE fragments. Analysis of apoE fragments by mass spectrometry showed cleavages occurring at the C-terminal side of apoE tryptophan residues, further supporting our identification of cleavage by chymotrypsin like protease. Hippocampal neurons were more efficient in mediating this apoE cleavage than cortical neurons. Proteolysis of apoE4 generated higher levels of low molecular weight fragments compared to apoE3. Primary glial cultures released an inhibitor of this proteolytic activity. Together, these studies reveal novel mechanism by which apoE can be regulated and therefore could be useful in designing apoE directed AD therapeutic approaches.

  12. Inhibition of cathepsin X reduces the strength of microglial-mediated neuroinflammation.

    Science.gov (United States)

    Pišlar, Anja; Božić, Biljana; Zidar, Nace; Kos, Janko

    2017-03-01

    Inflammation plays a central role in the processes associated with neurodegeneration. The inflammatory response is mediated by activated microglia that release inflammatory mediators to the neuronal environment. Microglia-derived lysosomal cathepsins, including cathepsin X, are increasingly recognized as important mediators of the inflammation involved in lipopolysaccharide (LPS)-induced neuroinflammation. The current study was undertaken to investigate the role of cathepsin X and its molecular target, γ-enolase, in neuroinflammation and to elucidate the underlying mechanism. We determined that the exposure of activated BV2 and EOC 13.31 cells to LPS led to increased levels of cathepsin X protein and activity in the culture supernatants in a concentration- and time-dependent manner. In contrast, LPS stimulation of these two cells reduced the release of active γ-enolase in a manner regulated by the cathepsin X activity. Cathepsin X inhibitor AMS36 significantly reduced LPS-induced production of nitric oxide, reactive oxygen species and the pro-inflammatory cytokines interleukin-6 and tumor necrosis factor-α from BV2 cells. Inhibition of cathepsin X suppressed microglial activation through the reduced caspase-3 activity, together with diminished microglial cell death and apoptosis, and also through inhibition of the activity of the mitogen-activated protein kinases. Further, SH-SY5Y treatment with culture supernatants of activated microglial cells showed that cathepsin X inhibition reduces microglia-mediated neurotoxicity. These results indicate that up-regulated expression and increased release and activity of microglial cathepsin X leads to microglia activation-mediated neurodegeneration. Cathepsin X inhibitor caused neuroprotection via its inhibition of the activation of microglia. Cathepsin X could thus be a potential therapeutic target for neuroinflammatory disorders.

  13. Symbiotic gut commensal bacteria act as host cathepsin S activity regulators.

    Science.gov (United States)

    Steimle, Alex; Gronbach, Kerstin; Beifuss, Brigitte; Schäfer, Andrea; Harmening, Robin; Bender, Annika; Maerz, Jan Kevin; Lange, Anna; Michaelis, Lena; Maurer, Andreas; Menz, Sarah; McCoy, Kathy; Autenrieth, Ingo B; Kalbacher, Hubert; Frick, Julia-Stefanie

    2016-12-01

    Cathepsin S (CTSS) is a lysosomal protease whose activity regulation is important for MHC-II signaling and subsequent activation of CD4(+) T cell mediated immune responses. Dysregulation of its enzymatic activity or enhanced secretion into extracellular environments is associated with the induction or progression of several autoimmune diseases. Here we demonstrate that commensal intestinal bacteria influence secretion rates and intracellular activity of host CTSS and that symbiotic bacteria, i.e. Bacteroides vulgatus mpk, may actively regulate this process and help to maintain physiological levels of CTSS activities in order to prevent from induction of pathological inflammation. The symbiont-controlled regulation of CTSS activity is mediated by anticipating reactive oxygen species induction in dendritic cells which, in turn, maintains cystatin C (CysC) monomer binding to CTSS. CysC monomers are potent endogenous CTSS inhibitors. This Bacteroides vulgatus caused and CysC dependent CTSS activity regulation is involved in the generation of tolerant intestinal dendritic cells contributing to prevention of T-cell mediated induction of colonic inflammation. Taken together, we demonstrate that symbionts of the intestinal microbiota regulate host CTSS activity and secretion and might therefore be an attractive approach to deal with CTSS associated autoimmune diseases. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Detection of oral squamous cell carcinoma metastasis with cathepsin D: An immunohistochemical approach

    Science.gov (United States)

    Kapoor, Seema; Kaur, Geet Priya; Sikka, Pranav

    2014-01-01

    Background: The lysosomal protease cathepsin D (CD) has been associated with tumor progression in malignant tumors including oral squamous cell carcinoma (OSCC). The purpose of this study was to find out any association between the CD and lymph node metastasis and to study the correlation of CD with various clinicopathological parameters to aid in assessment of its role as a prognostic indicator. Materials and Methods: Immunohistochemical staining was performed on 20 OSCC samples with polyclonal antibody against CD. Positive results indicative of the presence of CD were further analyzed to determine any correlation between the CD and other clinicopathological parameters. Pearson Chi-square analyses, Spearsman correlation coefficient, Mann-Whitney test, Kruskal Wallis test and student t test were used for statistical analysis (P < 0.05). Results: Patients with lymph node metastasis showed statistically significant increase in CD expression (P < 0.01). Increasing tumor size seemed to correlate with increased CD expression (P < 0.05). Conclusion: Based on its association with other clinicopathological variables, CD expression can be used for the assessment of patient survival in cases of OSCC. PMID:24932191

  15. The intrinsic microglial molecular clock controls synaptic strength via the circadian expression of cathepsin S.

    Science.gov (United States)

    Hayashi, Yoshinori; Koyanagi, Satoru; Kusunose, Naoki; Okada, Ryo; Wu, Zhou; Tozaki-Saitoh, Hidetoshi; Ukai, Kiyoharu; Kohsaka, Shinichi; Inoue, Kazuhide; Ohdo, Shigehiro; Nakanishi, Hiroshi

    2013-09-25

    Microglia are thought to play important roles in the maintenance of neuronal circuitry and the regulation of behavior. We found that the cortical microglia contain an intrinsic molecular clock and exhibit a circadian expression of cathepsin S (CatS), a microglia-specific lysosomal cysteine protease in the brain. The genetic deletion of CatS causes mice to exhibit hyperlocomotor activity and removes diurnal variations in the synaptic activity and spine density of the cortical neurons, which are significantly higher during the dark (waking) phase than the light (sleeping) phase. Furthermore, incubation with recombinant CatS significantly reduced the synaptic activity of the cortical neurons. These results suggest that CatS secreted by microglia during the dark-phase decreases the spine density of the cortical neurons by modifying the perisynaptic environment, leading to downscaling of the synaptic strength during the subsequent light-phase. Disruption of CatS therefore induces hyperlocomotor activity due to failure to downscale the synaptic strength.

  16. Detection of oral squamous cell carcinoma metastasis with cathepsin D: An immunohistochemical approach

    Directory of Open Access Journals (Sweden)

    Seema Kapoor

    2014-01-01

    Full Text Available Background: The lysosomal protease cathepsin D (CD has been associated with tumor progression in malignant tumors including oral squamous cell carcinoma (OSCC. The purpose of this study was to find out any association between the CD and lymph node metastasis and to study the correlation of CD with various clinicopathological parameters to aid in assessment of its role as a prognostic indicator. Materials and Methods: Immunohistochemical staining was performed on 20 OSCC samples with polyclonal antibody against CD. Positive results indicative of the presence of CD were further analyzed to determine any correlation between the CD and other clinicopathological parameters. Pearson Chi-square analyses, Spearsman correlation coefficient, Mann-Whitney test, Kruskal Wallis test and student t test were used for statistical analysis (P < 0.05. Results: Patients with lymph node metastasis showed statistically significant increase in CD expression (P < 0.01. Increasing tumor size seemed to correlate with increased CD expression (P < 0.05. Conclusion: Based on its association with other clinicopathological variables, CD expression can be used for the assessment of patient survival in cases of OSCC.

  17. Cystein cathepsin and Hsp90 activities determine the balance between apoptotic and necrotic cell death pathways in caspase-compromised U937 cells.

    Science.gov (United States)

    Imre, Gergely; Dunai, Zsuzsanna; Petak, Istvan; Mihalik, Rudolf

    2007-10-01

    Caspase-inhibited cells induced to die may exhibit the traits of either apoptosis or necrosis or both, simultaneously. However, mechanisms regulating the commitment to these distinct forms of cell death are barely identified. We found that staurosporine induced both apoptotic and necrotic traits in U937 cells exposed to the caspase inhibitor benzyloxycarbonyl-Val-Ala-DL-Asp(OMe)-fluoromethylketone. Morphology and flow cytometry revealed that individual cells exhibited either apoptotic or necrotic traits, but not the mixed phenotype. Inhibition of cathepsin activity by benzyloxycarbonyl-Phe-Ala-fluoromethylketone rendered caspase-compromised cells resistant to staurosporine-induced apoptosis, but switched the cell death form to necrosis. Inhibition of heat shock protein 90 kDa (Hsp90) chaperon activity by geldanamycin conferred resistance to necrosis in caspase-compromised cells but switched the cell death form to apoptosis. Combination of benzyloxycarbonyl-Phe-Ala-fluoromethylketone and geldanamycin halted the onset of both forms of cell death by saving mitochondrial trans-membrane potential and preventing acidic volume (lysosomes) loss. These effects of benzyloxycarbonyl-Phe-Ala-fluoromethylketone and/or geldanamycin on cell death were restricted to caspase-inhibited cells exposed to staurosporine but influenced neither only the staurosporine-provoked apoptosis nor hydrogen peroxide (H2O2)-generated necrosis. Our results demonstrate that the staurosporine-induced death pathway bifurcates in caspase-compromised cells and commitment to apoptotic or necrotic phenotypes depends on cathepsin protease or Hsp90 chaperon activities.

  18. Lysosomal disruption preferentially targets acute myeloid leukemia cells and progenitors

    Science.gov (United States)

    Sukhai, Mahadeo A.; Prabha, Swayam; Hurren, Rose; Rutledge, Angela C.; Lee, Anna Y.; Sriskanthadevan, Shrivani; Sun, Hong; Wang, Xiaoming; Skrtic, Marko; Seneviratne, Ayesh; Cusimano, Maria; Jhas, Bozhena; Gronda, Marcela; MacLean, Neil; Cho, Eunice E.; Spagnuolo, Paul A.; Sharmeen, Sumaiya; Gebbia, Marinella; Urbanus, Malene; Eppert, Kolja; Dissanayake, Dilan; Jonet, Alexia; Dassonville-Klimpt, Alexandra; Li, Xiaoming; Datti, Alessandro; Ohashi, Pamela S.; Wrana, Jeff; Rogers, Ian; Sonnet, Pascal; Ellis, William Y.; Corey, Seth J.; Eaves, Connie; Minden, Mark D.; Wang, Jean C.Y.; Dick, John E.; Nislow, Corey; Giaever, Guri; Schimmer, Aaron D.

    2012-01-01

    Despite efforts to understand and treat acute myeloid leukemia (AML), there remains a need for more comprehensive therapies to prevent AML-associated relapses. To identify new therapeutic strategies for AML, we screened a library of on- and off-patent drugs and identified the antimalarial agent mefloquine as a compound that selectively kills AML cells and AML stem cells in a panel of leukemia cell lines and in mice. Using a yeast genome-wide functional screen for mefloquine sensitizers, we identified genes associated with the yeast vacuole, the homolog of the mammalian lysosome. Consistent with this, we determined that mefloquine disrupts lysosomes, directly permeabilizes the lysosome membrane, and releases cathepsins into the cytosol. Knockdown of the lysosomal membrane proteins LAMP1 and LAMP2 resulted in decreased cell viability, as did treatment of AML cells with known lysosome disrupters. Highlighting a potential therapeutic rationale for this strategy, leukemic cells had significantly larger lysosomes compared with normal cells, and leukemia-initiating cells overexpressed lysosomal biogenesis genes. These results demonstrate that lysosomal disruption preferentially targets AML cells and AML progenitor cells, providing a rationale for testing lysosomal disruption as a novel therapeutic strategy for AML. PMID:23202731

  19. Molecular Cloning and Sequence of Channel Catfish (Ictalurus punctatus, Rafinesque 1818) Cathepsin S gene

    Science.gov (United States)

    Cathepsin S is a lysosomal cysteine endopeptidase of the papain family. This enzyme digests the invariant chain molecules so that antigenic peptides are able to load on the class II-associated invariant chain peptide of MHC. The complexes can subsequently be presented to the CD4 cell surface. In ...

  20. Involvement of cathepsin B in mitochondrial apoptosis by p-phenylenediamine under ambient UV radiation

    Energy Technology Data Exchange (ETDEWEB)

    Goyal, Shruti; Amar, Saroj Kumar [Photobiology Division, CSIR – Indian Institute of Toxicology Research, Post Box No. 80, M.G. Marg, Lucknow 226001, Uttar Pradesh (India); Academy of Scientific and Innovative Research, CSIR-IITR Campus, Lucknow (India); Dubey, Divya; Pal, Manish Kumar [Photobiology Division, CSIR – Indian Institute of Toxicology Research, Post Box No. 80, M.G. Marg, Lucknow 226001, Uttar Pradesh (India); Singh, Jyoti [Photobiology Division, CSIR – Indian Institute of Toxicology Research, Post Box No. 80, M.G. Marg, Lucknow 226001, Uttar Pradesh (India); Academy of Scientific and Innovative Research, CSIR-IITR Campus, Lucknow (India); Verma, Ankit; Kushwaha, Hari Narayan [Photobiology Division, CSIR – Indian Institute of Toxicology Research, Post Box No. 80, M.G. Marg, Lucknow 226001, Uttar Pradesh (India); Ray, Ratan Singh, E-mail: ratanray.2011@rediffmail.com [Photobiology Division, CSIR – Indian Institute of Toxicology Research, Post Box No. 80, M.G. Marg, Lucknow 226001, Uttar Pradesh (India)

    2015-12-30

    Highlights: • Photodegradation and formation of photoproduct. • Involvement of ROS in PPD phototoxicity. • Role of ROS in DNA damage, CPD and micronuclei formation. • PPD induced lysosomal destabilization and release of cathepsin B. • Cleavage of Bid and activation of mitochondrial apoptosis. - Abstract: Paraphenylenediamine (PPD), a derivative of paranitroaniline has been most commonly used as an ingredient of oxidative hair dye and permanent tattoos. We have studied the phototoxic potential of PPD under ambient ultraviolet radiation. PPD is photodegraded and form a novel photoproduct under UV A exposure. PPD shows a concentration dependent decrease in cell viability of human Keratinocyte cells (HaCaT) through MTT and NRU test. Significant intracellular ROS generation was measured by DCFDA assay. It caused an oxidative DNA damage via single stranded DNA breaks, micronuclei and CPD formation. Both lysosome and mitochondria is main target for PPD induced apoptosis which was proved through lysosomal destabilization and release of cathepsin B by immunofluorescence, real time PCR and western blot analysis. Cathepsin B process BID to active tBID which induces the release of cytochrome C from mitochondria. Mitochondrial depolarization was reported through transmission electron microscopy. The cathepsin inhibitor reduced the release of cytochrome C in PPD treated cells. Thus study suggests that PPD leads to apoptosis via the involvement of lysosome and mitochondria both under ambient UV radiation. Therefore, photosensitizing nature of hair dye ingredients should be tested before coming to market as a cosmetic product for the safety of human beings.

  1. Cathepsin Gene Family Reveals Transcriptome Patterns Related to the Infective Stages of the Salmon Louse Caligus rogercresseyi.

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    Waleska Maldonado-Aguayo

    Full Text Available Cathepsins are proteases involved in the ability of parasites to overcome and/or modulate host defenses so as to complete their own lifecycle. However, the mechanisms underlying this ability of cathepsins are still poorly understood. One excellent model for identifying and exploring the molecular functions of cathepsins is the marine ectoparasitic copepod Caligus rogercresseyi that currently affects the Chilean salmon industry. Using high-throughput transcriptome sequencing, 56 cathepsin-like sequences were found distributed in five cysteine protease groups (B, F, L, Z, and S as well as in an aspartic protease group (D. Ontogenic transcriptome analysis evidenced that L cathepsins were the most abundant during the lifecycle, while cathepsins B and K were mostly expressed in the larval stages and adult females, thus suggesting participation in the molting processes and embryonic development, respectively. Interestingly, a variety of cathepsins from groups Z, L, D, B, K, and S were upregulated in the infective stage of copepodid, corroborating the complexity of the processes involved in the parasitic success of this copepod. Putative functional roles of cathepsins were conjectured based on the differential expressions found and on roles previously described in other phylogenetically related species. Moreover, 140 single nucleotide polymorphisms (SNP were identified in transcripts annotated for cysteine and aspartic proteases located into untranslated regions, or the coding region. This study reports for the first time the presence of cathepsin-like genes and differential expressions throughout a copepod lifecycle. The identification of cathepsins together with functional validations represents a valuable strategy for pinpointing target molecules that could be used in the development of new delousing drugs or vaccines against C. rogercresseyi.

  2. Cathepsin D expression level affects alpha-synuclein processing, aggregation, and toxicity in vivo

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    Cullen Valerie

    2009-02-01

    Full Text Available Abstract Background Elevated SNCA gene expression and intracellular accumulation of the encoded α-synuclein (aSyn protein are associated with the development of Parkinson disease (PD. To date, few enzymes have been examined for their ability to degrade aSyn. Here, we explore the effects of CTSD gene expression, which encodes the lysosomal protease cathepsin D (CathD, on aSyn processing. Results Over-expression of human CTSD cDNA in dopaminergic MES23.5 cell cultures induced the marked proteolysis of exogenously expressed aSyn proteins in a dose-dependent manner. Unexpectedly, brain extractions, Western blotting and ELISA quantification revealed evidence for reduced levels of soluble endogenous aSyn in ctsd knock-out mice. However, these CathD-deficient mice also contained elevated levels of insoluble, oligomeric aSyn species, as detected by formic acid extraction. In accordance, immunohistochemical studies of ctsd-mutant brain from mice, sheep and humans revealed selective synucleinopathy-like changes that varied slightly among the three species. These changes included intracellular aSyn accumulation and formation of ubiquitin-positive inclusions. Furthermore, using an established Drosophila model of human synucleinopathy, we observed markedly enhanced retinal toxicity in ctsd-null flies. Conclusion We conclude from these complementary investigations that: one, CathD can effectively degrade excess aSyn in dopaminergic cells; two, ctsd gene mutations result in a lysosomal storage disorder that includes microscopic and biochemical evidence of aSyn misprocessing; and three, CathD deficiency facilitates aSyn toxicity. We therefore postulate that CathD promotes 'synucleinase' activity, and that enhancing its function may lower aSyn concentrations in vivo.

  3. Analysis of cathepsin and furin proteolytic enzymes involved in viral fusion protein activation in cells of the bat reservoir host.

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    Farah El Najjar

    Full Text Available Bats of different species play a major role in the emergence and transmission of highly pathogenic viruses including Ebola virus, SARS-like coronavirus and the henipaviruses. These viruses require proteolytic activation of surface envelope glycoproteins needed for entry, and cellular cathepsins have been shown to be involved in proteolysis of glycoproteins from these distinct virus families. Very little is currently known about the available proteases in bats. To determine whether the utilization of cathepsins by bat-borne viruses is related to the nature of proteases in their natural hosts, we examined proteolytic processing of several viral fusion proteins in cells derived from two fruit bat species, Pteropus alecto and Rousettus aegyptiacus. Our work shows that fruit bat cells have homologs of cathepsin and furin proteases capable of cleaving and activating both the cathepsin-dependent Hendra virus F and the furin-dependent parainfluenza virus 5 F proteins. Sequence analysis comparing Pteropus alecto furin and cathepsin L to proteases from other mammalian species showed a high degree of conservation; however significant amino acid variation occurs at the C-terminus of Pteropus alecto furin. Further analysis of furin-like proteases from fruit bats revealed that these proteases are catalytically active and resemble other mammalian furins in their response to a potent furin inhibitor. However, kinetic analysis suggests that differences may exist in the cellular localization of furin between different species. Collectively, these results indicate that the unusual role of cathepsin proteases in the life cycle of bat-borne viruses is not due to the lack of active furin-like proteases in these natural reservoir species; however, differences may exist between furin proteases present in fruit bats compared to furins in other mammalian species, and these differences may impact protease usage for viral glycoprotein processing.

  4. Involvement of the endosomal-lysosomal system correlates with regional pathology in Creutzfeldt-Jakob disease

    DEFF Research Database (Denmark)

    Kovács, Gábor G; Gelpi, Ellen; Ströbel, Thomas

    2007-01-01

    The endosomal-lysosomal system (ELS) has been suggested to play a role in the pathogenesis of prion diseases. The purpose of this study was to examine how experimental observations can be translated to human neuropathology and whether alterations of the ELS relate to neuropathologic changes....... Combined with stereologic techniques, we examined components of the ELS in human sporadic Creutzfeldt-Jakob disease brains. We immunostained for the early endosomal marker Rab5 and lysosomal enzymes cathepsin D and B. We determined neuron-specific changes in their expression and correlated......-immunoreactive lysosomes. The intraneuronal distribution of cathepsin D and B diverges between Purkinje cells and frontal cortical neurons in sporadic Creutzfeldt-Jakob disease brains. We demonstrated focal intra- and perineuronal colocalization of cathepsin D and PrP. Our results indicate that effects in the ELS...

  5. Silver and Gold Nanoparticles Alter Cathepsin Activity In vitro

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    Speshock Janice

    2011-01-01

    Full Text Available Abstract Nanomaterials are being incorporated into many biological applications for use as therapeutics, sensors, or labels. Silver nanomaterials are being utilized for biological implants and wound dressings as an antiviral material, whereas gold nanomaterials are being used as biological labels or sensors due to their surface properties and biocompatibility. Cytotoxicity data of these materials are becoming more prevalent; however, little research has been performed to understand how the introduction of these materials into cells affects cellular processes. Here, we demonstrate the impact that silver and gold nanoparticles have on cathepsin activity in vitro. Cathepsins are important cellular proteases that are imperative for proper immune system function. We have selected to examine gold and silver nanoparticles due to the increased use of these materials in biological applications. This manuscript depicts how both of these types of nanomaterials affect cathepsin activity, which could impact the host's immune system and its ability to respond to pathogens. Cathepsin B activity decreases in a dose-dependent manner with all nanoparticles tested. Alternatively, the impact of nanoparticles on cathepsin L activity depends greatly on the type and size of the material.

  6. Preventive effect of phytic acid on lysosomal hydrolases in normal and isoproterenol-induced myocardial infarction in Wistar rats.

    Science.gov (United States)

    Brindha, E; Rajasekapandiyan, M

    2015-02-01

    This study was aimed to evaluate the preventive role of phytic acid on lysosomal enzymes in isoproterenol (ISO)-induced myocardial infarction (MI) in male Wistar rats. Rats subcutaneously injected with ISO (85 mg/kg) at an interval of 24 h for two days showed a significant increase in the activities of lysosomal enzymes (glucuronidase, N-acetyl glucosaminidase, galactosidase, cathepsin-B and cathepsin-D) were increased significantly in serum and the heart of ISO-induced rats, but the activities of glucuronidase and cathepsin-D were decreased significantly in the lysosomal fraction of the heart. Pretreatment with phytic acid (25 and 50 mg/kg) daily for a period of 56 d positively altered activities of lysosomal hydrolases in ISO-induced rats. Thus, phytic acid possesses a cardioprotective effect in ISO-induced MI in rats.

  7. Acidic extracellular microenvironment promotes the invasion and cathepsin B secretion of PC-3 cells.

    Science.gov (United States)

    Gao, Li; Fang, You-Qiang; Zhang, Tian-Yu; Ge, Bo; Tang, Rong-Jing; Huang, Jie-Fu; Jiang, Lei-Ming; Tan, Ning

    2015-01-01

    This study aimed to investigate the effect of acidic microenvironment on the invasion of prostatic carcinoma PC-3 cells and to explore the potential mechanism. PC-3 cells were maintained in medium at different pHs (pH 7.4, pH 7.0 and pH 6.6). Invasion and metastasis of PC-3 cells were investigated in vitro. Acridine orange staining was performed, followed by laser confocal scanning microscopy for the localization of lysosomes. Western blot assay and ELISA were employed to evaluate the effect of acidic microenvironment on the cathepsin B secretion. Acidic microenvironment remarkably promote the invasion and migration of PC-3 cells (Pmicroenvironment promoted the cathepsin B secretion in PC- cells. Acidic microenvironment may significantly promote the invasion of PC-3 cells and increase the secretion of cathepsin B. This suggests that the acidic microenvironment induced invasion of PC- cells is related to the elevated cathepsin B secretion.

  8. Evaluation of synthetic acridones and 4-quinolinones as potent inhibitors of cathepsins L and V.

    Science.gov (United States)

    Marques, Emerson F; Bueno, Mauro A; Duarte, Patrícia D; Silva, Larissa R S P; Martinelli, Ariani M; dos Santos, Caio Y; Severino, Richele P; Brömme, Dieter; Vieira, Paulo C; Corrêa, Arlene G

    2012-08-01

    Cathepsins, also known as lysosomal cysteine peptidases, are members of the papain-like peptidase family, involved in different physiological processes. In addition, cathepsins are implicated in many pathological conditions. This report describes the synthesis and evaluation of a series of N-arylanthranilic acids, acridones, and 4-quinolinones as inhibitors of cathepsins V and L. The kinetics revealed that compounds of the classes of acridones are reversible competitive inhibitors of the target enzyme with affinities in the low micromolar range. They represent promising lead candidates for the discovery of novel competitive cathepsin inhibitors with enhanced selectivity and potency. On the other hand, 4-quinolinones were noncompetitive inhibitors and N-arylanthranilic acids were uncompetitive inhibitors.

  9. Protective effect of squalene on certain lysosomal hydrolases and free amino acids in isoprenaline-induced myocardial infarction in rats

    DEFF Research Database (Denmark)

    Farvin, Sabeena; Surendraraj, A.; Anandan, R.

    2010-01-01

    This study was aimed to evaluate the preventive role of squalene on free amino acids and lysosomal alterations in experimentally induced myocardial infarction in rats. The levels of lysosomal enzymes (beta-glucuronidase, beta-galactosidase, beta-glucosidase, acid phosphatase and cathepsin D......) in plasma and lysosomal fractions, hydroxyproline content and free amino acids in heart tissue were determined. Isoprenaline administration to rats resulted in decreased stability of the membranes which was reflected by significantly (p...

  10. Molecular cloning, characterization and expression analysis of cathepsin D gene from turbot Scophthalmus maximus.

    Science.gov (United States)

    Jia, Airong; Zhang, Xiao-Hua

    2009-04-01

    Cathepsin D is a lysosomal endoproteolytic aspartic proteinase which also has been found in endosomes of macrophage. It is thought to play key roles in the developmental and physiological process of animals. The EST sequence of turbot (Scophthalmus maximus L.) cathepsin D was obtained from a subtractive cDNA library. In the present study, 5'-RACE and 3'-RACE were carried out to obtain the complete cDNA sequence of turbot cathepsin D, which contained a 91 bp 5'-UTR, a 1191 bp open reading frame encoding 396 amino acids, and a 329 bp 3'-UTR. The deduced amino acid sequence of the cathepsin D consisted of a signal peptide of 18 aa, a leader peptide extending 43 aa, and a mature peptide of 335 aa. BLAST analysis revealed that turbot cathepsin D shared high similarity with other known cathepsin D, and it showed significant homology with that of Barramundi (Lates calcarifer B., 89% aa similarity). Quantitative real-time PCR (q PCR) demonstrated that the highest expression level of the turbot cathepsin D was in liver. After turbot were challenged with Vibrio harveyi, the lowest expression levels of cathepsin D in liver, spleen and head kidney were detected at 8 h. This result was different from the expression of MHCII of which the expression lever was increased upon challenge. The expression levels of cathepsin D in liver and head kidney increased gradually after 8 h and exceeded the background level after 24 h. In spleen, the expression level was reinforced after 8 h and kept at level that was higher than the original level after 12 h. The results suggested that cathepsin D might process antigens for presentation to the immune system and have synergetic effect with apoptosis pathway until 12 h after injection.

  11. A replacement of the active-site aspartic acid residue 293 in mouse cathepsin D affects its intracellular stability, processing and transport in HEK-293 cells.

    Science.gov (United States)

    Partanen, Sanna; Storch, Stephan; Löffler, Hans-Gerhard; Hasilik, Andrej; Tyynelä, Jaana; Braulke, Thomas

    2003-01-01

    The substitution of an active-site aspartic acid residue by asparagine in the lysosomal protease cathepsin D (CTSD) results in a loss of enzyme activity and severe cerebrocortical atrophy in a novel form of neuronal ceroid lipofuscinosis in sheep [Tyynelä, Sohar, Sleat, Gin, Donnelly, Baumann, Haltia and Lobel (2000) EMBO J. 19, 2786-2792]. In the present study we have introduced the corresponding mutation by replacing aspartic acid residue 293 with asparagine (D293N) into the mouse CTSD cDNA to analyse its effect on synthesis, transport and stability in transfected HEK-293 cells. The complete inactivation of mutant D293N mouse CTSD was confirmed by a newly developed fluorimetric quantification system. Moreover, in the heterologous overexpression systems used, mutant D293N mouse CTSD was apparently unstable and proteolytically modified during early steps of the secretory pathway, resulting in a loss of mass by about 1 kDa. In the affected sheep, the endogenous mutant enzyme was stable but also showed the shift in its molecular mass. In HEK-293 cells, the transport of the mutant D293N mouse CTSD to the lysosome was delayed and associated with a low secretion rate compared with wild-type CTSD. These data suggest that the mutation may result in a conformational change which affects stability, processing and transport of the enzyme. PMID:12350228

  12. Demonstration of elevated levels of active cathepsin S in dextran sulfate sodium colitis using a new activatable probe.

    Science.gov (United States)

    Barlow, N; Nasser, Y; Zhao, P; Sharma, N; Guerrero-Alba, R; Edgington-Mitchell, L E; Lieu, T; Veldhuis, N A; Poole, D P; Conner, J W; Lindström, E; Craig, A W; Graham, B; Vanner, S J; Bunnett, N W

    2015-11-01

    Proteases play a major role in inflammatory diseases of the gastrointestinal tract. Activatable probes are a major technological advance, enabling sensitive detection of active proteases in tissue samples. Our aim was to synthesize an activatable probe for cathepsin S and validate its use in a mouse model of colitis. We designed and synthesized a new fluorescent activatable probe, NB200, for the detection of active cathepsin S. Colitis was induced in C57BL/6 mice by the administration of 3% dextran sulfate sodium (DSS). Homogenized mouse colons, with or without the addition of the specific cathepsin S inhibitor MV026031, were incubated with NB200 in a fluorescent plate reader. NB200 selectively detected purified cathepsin S and not other common inflammatory proteases. Homogenates of colon from mice with DSS colitis induced a significant fluorescent increase when compared to control animals (control vs DSS: p < 0.05 at 200 min and p < 0.01 at 220-240 min), indicating cathepsin S activation. The cathepsin S inhibitor abolished this increase in fluorescence (DSS vs DSS + MV026031: p < 0.05 at 140 min, p < 0.01 at 180 min, p < 0.001 at 200-240 min), which confirms cathepsin S activation. Cathepsin S activity correlated with the disease activity index (Spearman r = 0.77, p = 0.017). Our investigation has demonstrated the utility of activatable probes for detecting protease activity in intestinal inflammation. Panels of such probes may allow 'signature' protease profiles to be established for a range of inflammatory diseases and disorders. © 2015 John Wiley & Sons Ltd.

  13. Hepatic steatosis inhibits autophagic proteolysis via impairment of autophagosomal acidification and cathepsin expression

    Energy Technology Data Exchange (ETDEWEB)

    Inami, Yoshihiro [Department of Gastroenterology, Juntendo University School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Yamashina, Shunhei, E-mail: syamashi@juntendo.ac.jp [Department of Gastroenterology, Juntendo University School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Izumi, Kousuke [Department of Gastroenterology, Juntendo University School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Ueno, Takashi [Department of Biochemistry, Juntendo University School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Tanida, Isei [Department of Biochemistry and Cell Biology, Laboratory of Biomembranes, National Institute of Infectious Disease, Toyama 1-23-1, Shinjuku-ku, Tokyo 162-8640 (Japan); Ikejima, Kenichi; Watanabe, Sumio [Department of Gastroenterology, Juntendo University School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan)

    2011-09-09

    Highlights: {yields} Acidification of autophagosome was blunted in steatotic hepatocytes. {yields} Hepatic steatosis did not disturb fusion of isolated autophagosome and lysosome. {yields} Proteinase activity of cathepsin B and L in autolysosomes was inhibited by steatosis. {yields} Hepatic expression of cathepsin B and L was suppressed by steatosis. -- Abstract: Autophagy, one of protein degradation system, contributes to maintain cellular homeostasis and cell defense. Recently, some evidences indicated that autophagy and lipid metabolism are interrelated. Here, we demonstrate that hepatic steatosis impairs autophagic proteolysis. Though accumulation of autophagosome is observed in hepatocytes from ob/ob mice, expression of p62 was augmented in liver from ob/ob mice more than control mice. Moreover, degradation of the long-lived protein leucine was significantly suppressed in hepatocytes isolated from ob/ob mice. More than 80% of autophagosomes were stained by LysoTracker Red (LTR) in hepatocytes from control mice; however, rate of LTR-stained autophagosomes in hepatocytes were suppressed in ob/ob mice. On the other hand, clearance of autolysosomes loaded with LTR was blunted in hepatocytes from ob/ob mice. Although fusion of isolated autophagosome and lysosome was not disturbed, proteinase activity of cathepsin B and L in autolysosomes and cathepsin B and L expression of liver were suppressed in ob/ob mice. These results indicate that lipid accumulation blunts autophagic proteolysis via impairment of autophagosomal acidification and cathepsin expression.

  14. Evaluation of serum cathepsin B and D in relation to clinicopathological staging of colorectal cancer

    Institute of Scientific and Technical Information of China (English)

    Elzbieta Skrzydlewska; Mariola Sulkowska; Andrzej Wincewicz; Mariusz Koda; Stanislaw Sulkowski

    2005-01-01

    AIM: Proteolytic degradation of the extracellular matrix facilitates cancer invasion and promotes metastasis. The study aims at evaluation of preoperative and postoperative serum cathepsins B and D levels in correlation with selected anatomoclinical features of colorectal cancer.METHODS: Blood samples were collected from 63colorectal cancer patients before curative operation of the tumor 10 d later. Blood that was obtained from 20healthy volunteers, served as a control. The activity of cathepsin B was measured with Bz-DL-arginine-pNA as a substrate at pH 6.0, while cathepsin D activity was determined with urea-denatured hemoglobin (pH 4.0).RESULTS: The preoperative and postoperative activities of cathepsin B were significantly (P<0.00001) lower in serum of colorectal cancer patients than in control group.However, postoperative values of this protease were significantly increased in comparison with preoperative ones (P = 0.031). Activity of cathepsin D appeared to be significantly higher in colorectal cancer sera (P<0.00001)compared with controls. No statistically significant differences between preoperative and postoperative activity of cathepsin D were noted (P = 0.09). We revealed a strong linkage of cathepsins' levels with lymph node status and pT stage of colorectal cancer.CONCLUSION: Blood serum activities of cathepsin B and D depend on the time of sampling, tumor size and lymph node involvement. Significantly, increased activity of cathepsin D could indicate a malignant condition of the large intestine. In our work, the serum postoperative decrease of cathepsin B activity appears as an obvious concomitant of local lymph node metastasis-the wellknown clinicopathological feature of poor prognosis.

  15. The effect of cathepsin K deficiency on airway development and TGF-β1 degradation

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    Saftig Paul

    2011-05-01

    Full Text Available Background Cathepsin K, a cysteine protease predominantly expressed in osteoclasts, is a major drug target for the treatment of osteoporosis. Recent findings, however, indicate that cathepsin K is also involved in non-skeletal metabolism. The development of fibrotic phenotypes in lung and skin is a concern for cathepsin K inhibitors presently evaluated in clinical trials. Cathepsin K is expressed in lung tissue and has been implicated in lung fibrosis. However, little is known about the role of cathepsin K in airway development and its effect on TGF-β1 degradation. Methods We investigated the effects of cathepsin K-deficiency on alterations in airway integrity, extracellular matrix composition, and TGF-β1 expression and degradation. Lung homogenates of wild-type and cathepsin K-deficient mice were used to evaluate their contents of collagen, glycosaminoglycans, and TGF-β1. The accessibility of TGF-β1 to cathepsin K-mediated degradation was determined in vitro and lung fibroblast proliferations in wild-type and cathepsin K-deficient cells were evaluated. Results Lung airway cathepsin K expression in wild-type mice remained constant between 1 and 6 months of age and the airway integrity was maintained. In contrast, after 2 months of age, all Ctsk-/- mice demonstrated increased airway epithelium thickness by 16-28%, a lower structural airway integrity (1-2 score units lower, elevated cytokeratin expression of 12%, increased α-actin and vimentin expression by 50% and 70%, increased area of smooth muscle cells by 15%, elevated hydroxyproline and GAGs content by 20% and 25%, and increased TGF-β1 expression by 25%. TGF-β1 proved an efficient substrate of cathepsin K and TGF-β1 protein content in lung was increased by a potent cathepsin inhibitor. Lung fibroblasts from Ctsk-/- mice after TGF-β1 treatment showed increased proliferation rates, increased levels of TGF-β1 by 30%, and increased ECM secretion. Conclusion This study suggests that

  16. Immunohistochemical expression of cathepsin L in atopic dermatitis and lichen planus

    Directory of Open Access Journals (Sweden)

    Zeinab A El Ashmawy

    2015-01-01

    Full Text Available Background: Cathepsin L is a member of papain superfamily. It seems to promote T-cell survival, selection maturation in the thymus and enhance the antigen presentation. Cathepsin L plays an important role in tumor necrosis factors (TNF-α induced cell death. Also it degrades the tight junction between cornedesomses in the epidermis. Elevated expression of cathepsin L has been found in many inflammatory and neoplastic diseases. Objective: The aim of this study was to determine immunohistochemical expression of cathepsin L in atopic dermatitis (AD and lichen planus (LP patients in order to evaluate its role in the pathogenesis of both diseases. Materials and Methods: This study included 15 patients with AD (Group I, 15 patients with LP (Group II, in addition to 10 healthy skin specimens served as controls (Group III. Punch biopsies were taken from lesional skin of the patients and controls for immunohistochemical detection of cathepsin L expression. Results: Highly significant increase was found in cathepsin L expression in AD and LP patients compared to controls [P = 0.001]. Conclusion: Cathepsin L could be implicated as an important protease in the pathogenesis of AD and LP. It could be a useful marker for assessing AD severity.

  17. Three-dimensional cultures modeling premalignant progression of human breast epithelial cells: role of cysteine cathepsins

    Science.gov (United States)

    Mullins, Stefanie R.; Sameni, Mansoureh; Blum, Galia; Bogyo, Matthew; Sloane, Bonnie F.; Moin, Kamiar

    2013-01-01

    The expression of the cysteine protease cathepsin B is increased in early stages of human breast cancer. To assess the potential role of cathepsin B in premalignant progression of breast epithelial cells, we employed a 3D reconstituted basement membrane overlay culture model of MCF10A human breast epithelial cells and isogenic variants that replicate the in vivo phenotypes of hyperplasia (MCF10AneoT) and atypical hyperplasia (MCF10AT1). MCF10A cells developed into polarized acinar structures with central lumens. In contrast, MCF10AneoT and MCF10AT1 cells form larger structures in which the lumens are filled with cells. CA074Me, a cell-permeable inhibitor selective for the cysteine cathepsins B and L, reduced proliferation and increased apoptosis of MCF10A, MCF10AneoT and MCF10AT1 cells in 3D culture. We detected active cysteine cathepsins in the isogenic MCF10 variants in 3D culture with GB111, a cell-permeable activity-based probe, and established differential inhibition of cathepsin B in our 3D cultures. We conclude that cathepsin B promotes proliferation and premalignant progression of breast epithelial cells. These findings are consistent with studies by others showing that deletion of cathepsin B in the transgenic MMTV-PyMT mice, a murine model that is predisposed to development of mammary cancer, reduces malignant progression. PMID:23667900

  18. Protective effects of sinapic acid on lysosomal dysfunction in isoproterenol induced myocardial infarcted rats.

    Science.gov (United States)

    Roy, Subhro Jyoti; Stanely Mainzen Prince, Ponnian

    2012-11-01

    In the pathology of myocardial infarction, lysosomal lipid peroxidation and resulting enzyme release play an important role. We evaluated the protective effects of sinapic acid on lysosomal dysfunction in isoproterenol induced myocardial infarcted rats. Male Wistar rats were treated with sinapic acid (12 mg/kg body weight) orally daily for 10 days and isoproterenol (100 mg/kg body weight) was injected twice at an interval of 24 h (9th and 10th day). Then, lysosomal lipid peroxidation, lysosomal enzymes in serum, heart homogenate, lysosomal fraction and myocardial infarct size were measured. Isoproterenol induced myocardial infarcted rats showed a significant increase in serum creatine kinase-MB and lysosomal lipid peroxidation. The activities of β-glucuronidase, β-galactosidase, cathepsin-B and D were significantly increased in serum, heart and the activities of β-glucuronidase and cathepsin-D were significantly decreased in lysosomal fraction of myocardial infarcted rats. Pre-and-co-treatment with sinapic acid normalized all the biochemical parameters and reduced myocardial infarct size in myocardial infarcted rats. In vitro studies confirmed the free radical scavenging effects of sinapic acid. The possible mechanisms for the observed effects are attributed to sinapic acid's free radical scavenging and membrane stabilizing properties. Thus, sinapic acid has protective effects on lysosomal dysfunction in isoproterenol induced myocardial infarcted rats.

  19. Chemoproteomic Strategy to Quantitatively Monitor Transnitrosation Uncovers Functionally Relevant S-Nitrosation Sites on Cathepsin D and HADH2.

    Science.gov (United States)

    Zhou, Yani; Wynia-Smith, Sarah L; Couvertier, Shalise M; Kalous, Kelsey S; Marletta, Michael A; Smith, Brian C; Weerapana, Eranthie

    2016-06-23

    S-Nitrosoglutathione (GSNO) is an endogenous transnitrosation donor involved in S-nitrosation of a variety of cellular proteins, thereby regulating diverse protein functions. Quantitative proteomic methods are necessary to establish which cysteine residues are most sensitive to GSNO-mediated transnitrosation. Here, a competitive cysteine-reactivity profiling strategy was implemented to quantitatively measure the sensitivity of >600 cysteine residues to transnitrosation by GSNO. This platform identified a subset of cysteine residues with a high propensity for GSNO-mediated transnitrosation. Functional characterization of previously unannotated S-nitrosation sites revealed that S-nitrosation of a cysteine residue distal to the 3-hydroxyacyl-CoA dehydrogenase type 2 (HADH2) active site impaired catalytic activity. Similarly, S-nitrosation of a non-catalytic cysteine residue in the lysosomal aspartyl protease cathepsin D (CTSD) inhibited proteolytic activation. Together, these studies revealed two previously uncharacterized cysteine residues that regulate protein function, and established a chemical-proteomic platform with capabilities to determine substrate specificity of other cellular transnitrosation agents.

  20. Prognostic and predictive value of cathepsin X in serum from colorectal cancer patients

    DEFF Research Database (Denmark)

    Vižin, Tjaša; Christensen, Ib Jarle; Wilhelmsen, Michael

    2014-01-01

    BACKGROUND: Cathepsin X is a cysteine protease involved in mechanisms of malignant progression. It is secreted from tumour cells as a proenzyme and may serve to predict the disease status and risk of death for cancer patients. In a previous, pilot, study on 77 colorectal patients we demonstrated...

  1. The relationship between Cd-induced autophagy and lysosomal activation in WRL-68 cells.

    Science.gov (United States)

    Meng, Su-Fang; Mao, Wei-Ping; Wang, Fang; Liu, Xiao-Qian; Shao, Luan-Luan

    2015-11-01

    This study shows that Cd induces autophagy in the human's embryonic normal liver cell line (WRL-68). The expression of LC3B-II and the mature cathepsin L were analyzed by Western blotting. The autophagosomes and lysosomes were directly visualized by electron microscopy and confocal microscopy analysis in Cd-exposed WRL-68 cells. In this study, we first found that autophagy induced the activation of lysosomal function in WRL-68 cells. The lysosomal activation was markedly decreased when the cells were co-treated with 3-MA (an inhibitor of autophagy). Secondly, we provided the evidence that the activation of lysosomal function depended on autophagosome-lysosome fusion. The colocalization of lysosome-associated membrane protein-2 (LAMP2) and GFP-LC3 was significantly reduced, when they were treated with thapsigargin (an inhibitor of autophagosome-lysosome fusion). We demonstrated that deletion or blockage of the autophagosome-lysosome fusion process effectively diminished lysosomal activation, which suggests that lysosomal activation occurring in the course of autophagy is dependent on autophagosome-lysosome fusion. Thirdly, we provided evidence that the activation of lysosomal function was associated with lysosomal acid. We investigated the relationship between autophagosome-lysosome fusion and pH in acidic compartments by visualizing fusion process in WRL-68 cells. This suggests that increasing pH in acidic compartments in WRL-68 cells inhibits the autophagosome-lysosome fusion. Finally, we found that the activation of lysosomal function was associated with Ca(2+) stores and the intracellular Ca(2+) channels or pumps were possibly pH-dependent.

  2. Autophagic flux promotes cisplatin resistance in human ovarian carcinoma cells through ATP-mediated lysosomal function.

    Science.gov (United States)

    Ma, Liwei; Xu, Ye; Su, Jing; Yu, Huimei; Kang, Jinsong; Li, Hongyan; Li, Xiaoning; Xie, Qi; Yu, Chunyan; Sun, Liankun; Li, Yang

    2015-11-01

    Lysosomes are involved in promoting resistance of cancer cells to chemotherapeutic agents. However, the mechanisms underlying lysosomal influence of cisplatin resistance in ovarian cancer remain incompletely understood. We report that, compared with cisplatin-sensitive SKOV3 cells, autophagy increases in cisplatin-resistant SKOV3/DDP cells treated with cisplatin. Inhibition of early-stage autophagy enhanced cisplatin-mediated cytotoxicity in SKOV3/DDP cells, but autophagy inhibition at a later stage by disturbing autophagosome-lysosome fusion is more effective. Notably, SKOV3/DDP cells contained more lysosomes than cisplatin-sensitive SKOV3 cells. Abundant lysosomes and lysosomal cathepsin D activity were required for continued autolysosomal degradation and maintenance of autophagic flux in SKOV3/DDP cells. Furthermore, SKOV3/DDP cells contain abundant lysosomal ATP required for lysosomal function, and inhibition of lysosomal ATP accumulation impaired lysosomal function and blocked autophagic flux. Therefore, our findings suggest that lysosomes at least partially contribute to cisplatin resistance in ovarian cancer cells through their role in cisplatin-induced autophagic processes, and provide insight into the mechanism of cisplatin resistance in tumors.

  3. The Role of Oxidized Cholesterol in Diabetes-Induced Lysosomal Dysfunction in the Brain.

    Science.gov (United States)

    Sims-Robinson, Catrina; Bakeman, Anna; Rosko, Andrew; Glasser, Rebecca; Feldman, Eva L

    2016-05-01

    Abnormalities in lysosomal function have been reported in diabetes, aging, and age-related degenerative diseases. These lysosomal abnormalities are an early manifestation of neurodegenerative diseases and often precede the onset of clinical symptoms such as learning and memory deficits; however, the mechanism underlying lysosomal dysfunction is not known. In the current study, we investigated the mechanism underlying lysosomal dysfunction in the cortex and hippocampi, key structures involved in learning and memory, of a type 2 diabetes (T2D) mouse model, the leptin receptor deficient db/db mouse. We demonstrate for the first time that diabetes leads to destabilization of lysosomes as well as alterations in the protein expression, activity, and/or trafficking of two lysosomal enzymes, hexosaminidase A and cathepsin D, in the hippocampus of db/db mice. Pioglitazone, a thiazolidinedione (TZD) commonly used in the treatment of diabetes due to its ability to improve insulin sensitivity and reverse hyperglycemia, was ineffective in reversing the diabetes-induced changes on lysosomal enzymes. Our previous work revealed that pioglitazone does not reverse hypercholesterolemia; thus, we investigated whether cholesterol plays a role in diabetes-induced lysosomal changes. In vitro, cholesterol promoted the destabilization of lysosomes, suggesting that lysosomal-related changes associated with diabetes are due to elevated levels of cholesterol. Since lysosome dysfunction precedes neurodegeneration, cognitive deficits, and Alzheimer's disease neuropathology, our results may provide a potential mechanism that links diabetes with complications of the central nervous system.

  4. Synthetic cyclohexenyl chalcone natural products possess cytotoxic activities against prostate cancer cells and inhibit cysteine cathepsins in vitro.

    Science.gov (United States)

    Deb Majumdar, Ishita; Devanabanda, Arvind; Fox, Benjamin; Schwartzman, Jacob; Cong, Huan; Porco, John A; Weber, Horst C

    2011-12-16

    A number of cyclohexenyl chalcone Diels-Alder natural products possess promising biological properties including strong cytotoxicity in various human cancer cells. Herein, we show that natural products in this class including panduratin A and nicolaioidesin C inhibit cysteine cathepsins as indicated by protease profiling assays and cell-free cathepsin L enzyme assays. Owing to the critical roles of cathepsins in the biology of human tumor progression, invasion, and metastasis, these findings should pave the way for development of novel antitumor agents for use in clinical settings.

  5. Mast cell proteases as pharmacological targets.

    Science.gov (United States)

    Caughey, George H

    2016-05-05

    Mast cells are rich in proteases, which are the major proteins of intracellular granules and are released with histamine and heparin by activated cells. Most of these proteases are active in the granule as well as outside of the mast cell when secreted, and can cleave targets near degranulating mast cells and in adjoining tissue compartments. Some proteases released from mast cells reach the bloodstream and may have far-reaching actions. In terms of relative amounts, the major mast cell proteases include the tryptases, chymases, cathepsin G, carboxypeptidase A3, dipeptidylpeptidase I/cathepsin C, and cathepsins L and S. Some mast cells also produce granzyme B, plasminogen activators, and matrix metalloproteinases. Tryptases and chymases are almost entirely mast cell-specific, whereas other proteases, such as cathepsins G, C, and L are expressed by a variety of inflammatory cells. Carboxypeptidase A3 expression is a property shared by basophils and mast cells. Other proteases, such as mastins, are largely basophil-specific, although human basophils are protease-deficient compared with their murine counterparts. The major classes of mast cell proteases have been targeted for development of therapeutic inhibitors. Also, a human β-tryptase has been proposed as a potential drug itself, to inactivate of snake venins. Diseases linked to mast cell proteases include allergic diseases, such as asthma, eczema, and anaphylaxis, but also include non-allergic diseases such as inflammatory bowel disease, autoimmune arthritis, atherosclerosis, aortic aneurysms, hypertension, myocardial infarction, heart failure, pulmonary hypertension and scarring diseases of lungs and other organs. In some cases, studies performed in mouse models suggest protective or homeostatic roles for specific proteases (or groups of proteases) in infections by bacteria, worms and other parasites, and even in allergic inflammation. At the same time, a clearer picture has emerged of differences in the

  6. Factors influencing the measurement of lysosomal enzymes activity in human cerebrospinal fluid.

    Directory of Open Access Journals (Sweden)

    Emanuele Persichetti

    Full Text Available Measurements of the activities of lysosomal enzymes in cerebrospinal fluid have recently been proposed as putative biomarkers for Parkinson's disease and other synucleinopathies. To define the operating procedures useful for ensuring the reliability of these measurements, we analyzed several pre-analytical factors that may influence the activity of β-glucocerebrosidase, α-mannosidase, β-mannosidase, β-galactosidase, α-fucosidase, β-hexosaminidase, cathepsin D and cathepsin E in cerebrospinal fluid. Lysosomal enzyme activities were measured by well-established fluorimetric assays in a consecutive series of patients (n = 28 with different neurological conditions, including Parkinson's disease. The precision, pre-storage and storage conditions, and freeze/thaw cycles were evaluated. All of the assays showed within- and between-run variabilities below 10%. At -20°C, only cathepsin D was stable up to 40 weeks. At -80°C, the cathepsin D, cathepsin E, and β-mannosidase activities did not change significantly up to 40 weeks, while β-glucocerebrosidase activity was stable up to 32 weeks. The β-galactosidase and α-fucosidase activities significantly increased (+54.9±38.08% after 4 weeks and +88.94±36.19% after 16 weeks, respectively. Up to four freeze/thaw cycles did not significantly affect the activities of cathepsins D and E. The β-glucocerebrosidase activity showed a slight decrease (-14.6% after two freeze/thaw cycles. The measurement of lysosomal enzyme activities in cerebrospinal fluid is reliable and reproducible if pre-analytical factors are accurately taken into consideration. Therefore, the analytical recommendations that ensue from this study may contribute to the establishment of actual values for the activities of cerebrospinal fluid lysosomal enzymes as putative biomarkers for Parkinson's disease and other neurodegenerative disorders.

  7. The research of neurospecific proteins and lysosomal peptidehydrolases in frontal neocortex during forming conditioned reaction of active avoiding of rats

    Directory of Open Access Journals (Sweden)

    Vyatkin O. K.

    2009-04-01

    Full Text Available Dynamics of the activity of neuronal cell adhesion molecule (NCAM and lysosomal cysteine cathepsins B, L, H was researched in frontal neocortex of rat brain during forming a conditioned reaction of active avoiding. The quantitative estimation of NCAM content in the neocortex membrane fraction was carried on by ELISA in 3, 7, 14 and 21 days after starting animals’ training. The dynamics correlation between the NCAM content increasing and cysteine cathepsins activity was obtained, especially for aminopeptidase cathepsin H during the process of memory engram forming in frontal neocortex of rat brain.

  8. A primitive enzyme for a primitive cell: the protease required for excystation of Giardia.

    Science.gov (United States)

    Ward, W; Alvarado, L; Rawlings, N D; Engel, J C; Franklin, C; McKerrow, J H

    1997-05-02

    Protozoan parasites of the genus Giardia are one of the earliest lineages of eukaryotic cells. To initiate infection, trophozoites emerge from a cyst in the host. Excystation is blocked by specific cysteine protease inhibitors. Using a biotinylated inhibitor, the target protease was identified and its corresponding gene cloned. The protease was localized to vesicles that release their contents just prior to excystation. The Giardia protease is the earliest known branch of the cathepsin B family. Its phylogeny confirms that the cathepsin B lineage evolved in primitive eukaryotic cells, prior to the divergence of plant and animal kingdoms, and underscores the diversity of cellular functions that this enzyme family facilitates.

  9. Changes in the morphology and lability of lysosomal subpopulations in caerulein-induced acute pancreatitis.

    Science.gov (United States)

    Sarmiento, Nancy; Sánchez-Yagüe, Jesús; Juanes, Pedro P; Pérez, Nieves; Ferreira, Laura; García-Hernández, Violeta; Mangas, Arturo; Calvo, José J; Sánchez-Bernal, Carmen

    2011-02-01

    Lysosomes play an important role in acute pancreatitis (AP). Here we developed a method for the isolation of lysosome subpopulations from rat pancreas and assessed the stability of lysosomal membranes. AP was induced by four subcutaneous injections of 20 μg caerulein/kg body weight at hourly intervals. The animals were killed 9h after the first injection. Marker enzymes [N-acetyl-β-D-glucosaminidase (NAG), cathepsin B and succinate dehydrogenase (SDH)] were assayed in subcellular fractions from control pancreas and in pancreatitis. Lysosomal subpopulations were separated by Percoll density gradient centrifugation and observed by electron microscopy. NAG molecular forms were determined by DEAE-cellulose chromatography. AP was associated with: (i) increases in the specific activity of lysosomal enzymes in the soluble fraction, (ii) changes in the size and alterations in the morphology of the organelles from the lysosomal subpopulations, (iii) the appearance of large vacuoles in the primary and secondary lysosome subpopulations, (iv) the increase in the amount of the NAG form associated with the pancreatic lysosomal membrane as well as its release towards the soluble fraction. Lysosome subpopulations are separated by a combination of differential and Percoll density gradient centrifugations. Primary lysosome membrane stability decreases in AP. Copyright © 2010 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  10. Streptococcus oralis Induces Lysosomal Impairment of Macrophages via Bacterial Hydrogen Peroxide.

    Science.gov (United States)

    Okahashi, Nobuo; Nakata, Masanobu; Kuwata, Hirotaka; Kawabata, Shigetada

    2016-07-01

    Streptococcus oralis, an oral commensal, belongs to the mitis group of streptococci and occasionally causes opportunistic infections, such as bacterial endocarditis and bacteremia. Recently, we found that the hydrogen peroxide (H2O2) produced by S. oralis is sufficient to kill human monocytes and epithelial cells, implying that streptococcal H2O2 is a cytotoxin. In the present study, we investigated whether streptococcal H2O2 impacts lysosomes, organelles of the intracellular digestive system, in relation to cell death. S. oralis infection induced the death of RAW 264 macrophages in an H2O2-dependent manner, which was exemplified by the fact that exogenous H2O2 also induced cell death. Infection with either a mutant lacking spxB, which encodes pyruvate oxidase responsible for H2O2 production, or Streptococcus mutans, which does not produce H2O2, showed less cytotoxicity. Visualization of lysosomes with LysoTracker revealed lysosome deacidification after infection with S. oralis or exposure to H2O2, which was corroborated by acridine orange staining. Similarly, fluorescent labeling of lysosome-associated membrane protein-1 gradually disappeared during infection with S. oralis or exposure to H2O2 The deacidification and the following induction of cell death were inhibited by chelating iron in lysosomes. Moreover, fluorescent staining of cathepsin B indicated lysosomal destruction. However, treatment of infected cells with a specific inhibitor of cathepsin B had negligible effects on cell death; instead, it suppressed the detachment of dead cells from the culture plates. These results suggest that streptococcal H2O2 induces cell death with lysosomal destruction and then the released lysosomal cathepsins contribute to the detachment of the dead cells.

  11. Cysteine Cathepsins in Human Carious Dentin

    Science.gov (United States)

    Nascimento, F.D.; Minciotti, C.L.; Geraldeli, S.; Carrilho, M.R.; Pashley, D.H.; Tay, F.R.; Nader, H.B.; Salo, T.; Tjäderhane, L.; Tersariol, I.L.S.

    2011-01-01

    Matrix metalloproteinases (MMPs) are important in dentinal caries, and analysis of recent data demonstrates the presence of other collagen-degrading enzymes, cysteine cathepsins, in human dentin. This study aimed to examine the presence, source, and activity of cysteine cathepsins in human caries. Cathepsin B was detected with immunostaining. Saliva and dentin cysteine cathepsin and MMP activities on caries lesions were analyzed spectrofluorometrically. Immunostaining demonstrated stronger cathepsins B in carious than in healthy dentin. In carious dentin, cysteine cathepsin activity increased with increasing depth and age in chronic lesions, but decreased with age in active lesions. MMP activity decreased with age in both active and chronic lesions. Salivary MMP activities were higher in patients with active than chronic lesions and with increasing lesion depth, while cysteine cathepsin activities showed no differences. The results indicate that, along with MMPs, cysteine cathepsins are important, especially in active and deep caries. PMID:21248362

  12. Quinazoline derivatives as cathepsins B, H and L inhibitors and cell proliferating agents.

    Science.gov (United States)

    Raghav, Neera; Jangra, Suman; Kumar, Ajay; Bhattacharyya, Shalmoli

    2017-01-01

    Cysteine Cathepsins well known to be involved in cancer, inflammation and regulation of degenerative processes like apoptosis have become specific targets in drug designing. The potential of quinazolines and their derivatives in medicinal chemistry led us to synthesise a novel series of seven compounds of quinazolines to evaluate their effect on cathepsins and cellular aspects of HepG2 cells. In the present work we report the solvent free microwave assisted synthesis of (E)-8-benzylidene-5,6,7,8-tetrahydro-2,4-diarylquinazolines as inhibitors of mammalian hepatic cysteine proteases viz. Cathepsins B, H and L. In vitro inhibition of Cathepsins B, H and L is correlated well with in vitro studies when tested using MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) assay on HepG2 cells, hepatocellular carcinoma cell line. The studies have been extended to evaluate the type of inhibition exhibited by the individual enzyme. Out of the seven compounds 1g i.e. (E)-8-(4-fluorobenzylidene)-4-(4-fluorophenyl)-2-phenyl-5, 6, 7, 8-tetrahydroquinazoline has been found to be most inhibitory for Cathepsins B, H and L to a maximum extent with the Ki values of 10(-10)M, 10(-10)M and 10(-9)M order respectively. In silico studies of all compounds have also been done at the active sites of Cathepsin B, H and L. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. High sphingomyelin levels induce lysosomal damage and autophagy dysfunction in Niemann Pick disease type A

    Science.gov (United States)

    Gabandé-Rodríguez, E; Boya, P; Labrador, V; Dotti, C G; Ledesma, M D

    2014-01-01

    Niemann Pick disease type A (NPA), which is caused by loss of function mutations in the acid sphingomyelinase (ASM) gene, is a lysosomal storage disorder leading to neurodegeneration. Yet, lysosomal dysfunction and its consequences in the disease are poorly characterized. Here we show that undegraded molecules build up in neurons of acid sphingomyelinase knockout mice and in fibroblasts from NPA patients in which autophagolysosomes accumulate. The latter is not due to alterations in autophagy initiation or autophagosome–lysosome fusion but because of inefficient autophago–lysosomal clearance. This, in turn, can be explained by lysosomal membrane permeabilization leading to cytosolic release of Cathepsin B. High sphingomyelin (SM) levels account for these effects as they can be induced in control cells on addition of the lipid and reverted on SM-lowering strategies in ASM-deficient cells. These results unveil a relevant role for SM in autophagy modulation and characterize autophagy anomalies in NPA, opening new perspectives for therapeutic interventions. PMID:24488099

  14. Mild MPP(+) exposure impairs autophagic degradation through a novel lysosomal acidity-independent mechanism.

    Science.gov (United States)

    Miyara, Masatsugu; Kotake, Yaichiro; Tokunaga, Wataru; Sanoh, Seigo; Ohta, Shigeru

    2016-10-01

    Parkinson's disease (PD) is the second most common neurodegenerative disorder, but its underlying cause remains unknown. Although recent studies using PD-related neurotoxin MPP(+) suggest autophagy involvement in the pathogenesis of PD, the effect of MPP(+) on autophagic processes under mild exposure, which mimics the slow progressive nature of PD, remains largely unclear. We examined the effect of mild MPP(+) exposure (10 and 200 μM for 48 h), which induces a more slowly developing cell death, on autophagic processes and the mechanistic differences with acute MPP(+) toxicity (2.5 and 5 mM for 24 h). In SH-SY5Y cells, mild MPP(+) exposure predominantly inhibited autophagosome degradation, whereas acute MPP(+) exposure inhibited both autophagosome degradation and basal autophagy. Mild MPP(+) exposure reduced lysosomal hydrolase cathepsin D activity without changing lysosomal acidity, whereas acute exposure decreased lysosomal density. Lysosome biogenesis enhancers trehalose and rapamycin partially alleviated mild MPP(+) exposure induced impaired autophagosome degradation and cell death, but did not prevent the pathogenic response to acute MPP(+) exposure, suggesting irreversible lysosomal damage. We demonstrated impaired autophagic degradation by MPP(+) exposure and mechanistic differences between mild and acute MPP(+) toxicities. Mild MPP(+) toxicity impaired autophagosome degradation through novel lysosomal acidity-independent mechanisms. Sustained mild lysosomal damage may contribute to PD. We examined the effects of MPP(+) on autophagic processes under mild exposure, which mimics the slow progressive nature of Parkinson's disease, in SH-SY5Y cells. This study demonstrated impaired autophagic degradation through a reduction in lysosomal cathepsin D activity without altering lysosomal acidity by mild MPP(+) exposure. Mechanistic differences between acute and mild MPP(+) toxicity were also observed. Sustained mild damage of lysosome may be an underlying cause

  15. Identification of cytoskeleton-associated proteins essential for lysosomal stability and survival of human cancer cells.

    Science.gov (United States)

    Groth-Pedersen, Line; Aits, Sonja; Corcelle-Termeau, Elisabeth; Petersen, Nikolaj H T; Nylandsted, Jesper; Jäättelä, Marja

    2012-01-01

    Microtubule-disturbing drugs inhibit lysosomal trafficking and induce lysosomal membrane permeabilization followed by cathepsin-dependent cell death. To identify specific trafficking-related proteins that control cell survival and lysosomal stability, we screened a molecular motor siRNA library in human MCF7 breast cancer cells. SiRNAs targeting four kinesins (KIF11/Eg5, KIF20A, KIF21A, KIF25), myosin 1G (MYO1G), myosin heavy chain 1 (MYH1) and tropomyosin 2 (TPM2) were identified as effective inducers of non-apoptotic cell death. The cell death induced by KIF11, KIF21A, KIF25, MYH1 or TPM2 siRNAs was preceded by lysosomal membrane permeabilization, and all identified siRNAs induced several changes in the endo-lysosomal compartment, i.e. increased lysosomal volume (KIF11, KIF20A, KIF25, MYO1G, MYH1), increased cysteine cathepsin activity (KIF20A, KIF25), altered lysosomal localization (KIF25, MYH1, TPM2), increased dextran accumulation (KIF20A), or reduced autophagic flux (MYO1G, MYH1). Importantly, all seven siRNAs also killed human cervix cancer (HeLa) and osteosarcoma (U-2-OS) cells and sensitized cancer cells to other lysosome-destabilizing treatments, i.e. photo-oxidation, siramesine, etoposide or cisplatin. Similarly to KIF11 siRNA, the KIF11 inhibitor monastrol induced lysosomal membrane permeabilization and sensitized several cancer cell lines to siramesine. While KIF11 inhibitors are under clinical development as mitotic blockers, our data reveal a new function for KIF11 in controlling lysosomal stability and introduce six other molecular motors as putative cancer drug targets.

  16. TRPML and lysosomal function.

    Science.gov (United States)

    Zeevi, David A; Frumkin, Ayala; Bach, Gideon

    2007-08-01

    Mucolipin 1 (MLN1), also known as TRPML1, is a member of the mucolipin family. The mucolipins are the only lysosomal proteins within the TRP superfamily. Mutations in the gene coding for TRPML1 result in a lysosomal storage disorder (LSD). This review summarizes the current knowledge related to this protein and the rest of the mucolipin family.

  17. The proteome of lysosomes.

    Science.gov (United States)

    Schröder, Bernd A; Wrocklage, Christian; Hasilik, Andrej; Saftig, Paul

    2010-11-01

    Lysosomes are organelles of eukaryotic cells that are critically involved in the degradation of macromolecules mainly delivered by endocytosis and autophagocytosis. Degradation is achieved by more than 60 hydrolases sequestered by a single phospholipid bilayer. The lysosomal membrane facilitates interaction and fusion with other compartments and harbours transport proteins catalysing the export of catabolites, thereby allowing their recycling. Lysosomal proteins have been addressed in various proteomic studies that are compared in this review regarding the source of material, the organelle/protein purification scheme, the proteomic methodology applied and the proteins identified. Distinguishing true constituents of an organelle from co-purifying contaminants is a central issue in subcellular proteomics, with additional implications for lysosomes as being the site of degradation of many cellular and extracellular proteins. Although many of the lysosomal hydrolases were identified by classical biochemical approaches, the knowledge about the protein composition of the lysosomal membrane has remained fragmentary for a long time. Using proteomics many novel lysosomal candidate proteins have been discovered and it can be expected that their functional characterisation will help to understand functions of lysosomes at a molecular level that have been characterised only phenomenologically so far and to generally deepen our understanding of this indispensable organelle.

  18. Imaging Primary Mouse Sarcomas After Radiation Therapy Using Cathepsin-Activatable Fluorescent Imaging Agents

    Energy Technology Data Exchange (ETDEWEB)

    Cuneo, Kyle C. [Department of Radiation Oncology, Duke University School of Medicine, Durham, North Carolina (United States); Mito, Jeffrey K.; Javid, Melodi P. [Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina (United States); Ferrer, Jorge M. [Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts (United States); Kim, Yongbaek [Department of Clinical Pathology, College of Veterinary Medicine, Seoul National University, Seoul (Korea, Republic of); Lee, W. David [The David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts (United States); Bawendi, Moungi G. [Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts (United States); Brigman, Brian E. [Department of Orthopedic Surgery, Duke University School of Medicine, Durham, North Carolina (United States); Kirsch, David G., E-mail: david.kirsch@duke.edu [Department of Radiation Oncology, Duke University School of Medicine, Durham, North Carolina (United States); Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina (United States)

    2013-05-01

    Purpose: Cathepsin-activated fluorescent probes can detect tumors in mice and in canine patients. We previously showed that these probes can detect microscopic residual sarcoma in the tumor bed of mice during gross total resection. Many patients with soft tissue sarcoma (STS) and other tumors undergo radiation therapy (RT) before surgery. This study assesses the effect of RT on the ability of cathepsin-activated probes to differentiate between normal and cancerous tissue. Methods and Materials: A genetically engineered mouse model of STS was used to generate primary hind limb sarcomas that were treated with hypofractionated RT. Mice were injected intravenously with cathepsin-activated fluorescent probes, and various tissues, including the tumor, were imaged using a hand-held imaging device. Resected tumor and normal muscle samples were harvested to assess cathepsin expression by Western blot. Uptake of activated probe was analyzed by flow cytometry and confocal microscopy. Parallel in vitro studies using mouse sarcoma cells were performed. Results: RT of primary STS in mice and mouse sarcoma cell lines caused no change in probe activation or cathepsin protease expression. Increasing radiation dose resulted in an upward trend in probe activation. Flow cytometry and immunofluorescence showed that a substantial proportion of probe-labeled cells were CD11b-positive tumor-associated immune cells. Conclusions: In this primary murine model of STS, RT did not affect the ability of cathepsin-activated probes to differentiate between tumor and normal muscle. Cathepsin-activated probes labeled tumor cells and tumor-associated macrophages. Our results suggest that it would be feasible to include patients who have received preoperative RT in clinical studies evaluating cathepsin-activated imaging probes.

  19. Hormonal and cholinergic influences on pancreatic lysosomal and digestive enzymes in rats.

    Science.gov (United States)

    Evander, A; Ihse, I; Lundquist, I

    1983-01-01

    Hormonal and cholinergic influences on lysosomal and digestive enzyme activities in pancreatic tissue were studied in normal adult rats. Hormonal stimulation by the cholecystokinin analogue, caerulein, induced a marked enhancement of the activities of cathepsin D and N-acetyl-beta-D-glucosaminidase in pancreatic tissue, whereas the activities of amylase and lipase tended to decrease. Acid phosphatase activity was not affected. Further, caerulein was found to induce a significant increase of cathepsin D output in bile-pancreatic juice. This output largely parallelled that of amylase. Cholinergic stimulation by the muscarinic agonist carbachol, at a dose level giving the same output of amylase as caerulein, did not affect pancreatic activities of cathepsin D and N-acetyl-beta-D-glucosaminidase. Further, cholinergic stimulation induced an increase of amylase activity and a slight decrease of acid phosphatase activity in pancreatic tissue. Lipase activity was not affected. No apparent effect on cathepsin D output in bile-pancreatic juice was encountered after cholinergic stimulation. The activities of neither the digestive nor the lysosomal enzymes were influenced by the administration of secretin. The results suggest a possible lysosomal involvement in caerulein-induced secretion and/or inactivation of pancreatic digestive enzymes, whereas cholinergic stimulation seems to act through different mechanisms.

  20. Evaluation of cathepsin B activity for degrading collagen IV using a surface plasmon resonance method and circular dichroism spectroscopy.

    Science.gov (United States)

    Shoji, Atsushi; Kabeya, Mitsutaka; Ishida, Yuuki; Yanagida, Akio; Shibusawa, Yoichi; Sugawara, Masao

    2014-07-01

    Evaluation of cathepsin B activities for degrading collagen IV and heat-denatured collagen IV (gelatin) were performed by surface plasmon resonance (SPR) and circular dichroism (CD) measurements. The optimal pH of cathepsin B activity for degrading each substrate was around 4.0. The ΔRU(15 min), which is a decrease in the SPR signal at 15 min after injection of cathepsin B, was smaller for collagen IV than for heat-denatured collagen IV owing to the presence of triple-helical conformation. An unstable nature of the triple-helical conformation of collagen IV at pH 4.0 was shown by the CD study. Degrading collagen IV by cathepsin B was facilitated owing to a local unwinding of the triple-helical conformation caused by proteolytic cleavage of the non-helical region. The concentration dependence of the initial velocity for degrading collagen IV by cathepsin B at pH 4.0 was biphasic, showing that cathepsin B at low concentration exhibits exopeptidase activity, while the enzyme at high concentration exhibits endopeptidase activity. The kinetic parameters for the exopeptidase activity of cathepsin B toward collagen IV and heat-treated collagen IV were evaluated and discussed in terms of the protease mechanism.

  1. Quantitative electrochemical detection of cathepsin B activity in complex tissue lysates using enhanced AC voltammetry at carbon nanofiber nanoelectrode arrays.

    Science.gov (United States)

    Swisher, Luxi Z; Prior, Allan M; Shishido, Stephanie; Nguyen, Thu A; Hua, Duy H; Li, Jun

    2014-06-15

    The proteolytic activity of a cancer-related enzyme cathepsin B is measured with alternating current voltammetry (ACV) using ferrocene (Fc) labeled tetrapeptides attached to nanoelectrode arrays (NEAs) fabricated with vertically aligned carbon nanofibers (VACNFs). This combination enables the use of high AC frequencies (~1kHz) with enhanced electrochemical signals. The specific proteolysis of the Fc-peptide by cathepsin B produces decay in the ACV peak current versus the reaction time. The exponential component of the raw data can be extracted and defined as the "extracted proteolytic signal" which allows consistent quantitative analyses using a heterogeneous Michaelis-Menten model. A "specificity constant" kcat/KM = (3.68 ± 0.50) × 10(4)M(-1)s(-1) for purified cathepsin B was obtained. The detections of cathepsin B activity in different concentrations of whole lysate of human breast tissue, tissue lysate spiked with varied concentrations of cathepsin B, and the tissue lysate after immunoprecipitation showed that there is ~13.4 nM higher cathepsin B concentration in 29.1 µg mL(-1) of whole tissue lysate than the immunoprecipitated sample. The well-defined regular VACNF NEAs by e-beam lithography show a much faster kinetics for cathepsin B proteolysis with kcat/KM = 9.2 × 10(4)M(-1)s(-1). These results illustrate the potential of this technique as a portable multiplex electronic system for cancer diagnosis by rapid protease profiling of serum or blood samples.

  2. Endothelial Nlrp3 inflammasome activation associated with lysosomal destabilization during coronary arteritis.

    Science.gov (United States)

    Chen, Yang; Li, Xiang; Boini, Krishna M; Pitzer, Ashley L; Gulbins, Erich; Zhang, Yang; Li, Pin-Lan

    2015-02-01

    Inflammasomes play a critical role in the development of vascular diseases. However, the molecular mechanisms activating the inflammasome in endothelial cells and the relevance of this inflammasome activation is far from clear. Here, we investigated the mechanisms by which an Nlrp3 inflammasome is activated to result in endothelial dysfunction during coronary arteritis by Lactobacillus casei (L. casei) cell wall fragments (LCWE) in a mouse model for Kawasaki disease. Endothelial dysfunction associated with increased vascular cell adhesion protein 1 (VCAM-1) expression and endothelial-leukocyte adhesion was observed during coronary arteritis in mice treated with LCWE. Accompanied with these changes, the inflammasome activation was also shown in coronary arterial endothelium, which was characterized by a marked increase in caspase-1 activity and IL-1β production. In cultured endothelial cells, LCWE induced Nlrp3 inflammasome formation, caspase-1 activation and IL-1β production, which were blocked by Nlrp3 gene silencing or lysosome membrane stabilizing agents such as colchicine, dexamethasone, and ceramide. However, a potassium channel blocker glibenclamide or an oxygen free radical scavenger N-acetyl-l-cysteine had no effects on LCWE-induced inflammasome activation. LCWE also increased endothelial cell lysosomal membrane permeability and triggered lysosomal cathepsin B release into cytosol. Silencing cathepsin B blocked LCWE-induced Nlrp3 inflammasome formation and activation in endothelial cells. In vivo, treatment of mice with cathepsin B inhibitor also abolished LCWE-induced inflammasome activation in coronary arterial endothelium. It is concluded that LCWE enhanced lysosomal membrane permeabilization and consequent release of lysosomal cathepsin B, resulting in activation of the endothelial Nlrp3 inflammasome, which may contribute to the development of coronary arteritis.

  3. Lysosomal Membrane Permeabilization is an Early Event in Sigma-2 Receptor Ligand Mediated Cell Death in Pancreatic Cancer

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    Hornick John R

    2012-05-01

    Full Text Available Abstract Background Sigma-2 receptor ligands have been studied for treatment of pancreatic cancer because they are preferentially internalized by proliferating cells and induce apoptosis. This mechanism of apoptosis is poorly understood, with varying reports of caspase-3 dependence. We evaluated multiple sigma-2 receptor ligands in this study, each shown to decrease tumor burden in preclinical models of human pancreatic cancer. Results Fluorescently labeled sigma-2 receptor ligands of two classes (derivatives of SW43 and PB282 localize to cell membrane components in Bxpc3 and Aspc1 pancreatic cancer cells and accumulate in lysosomes. We found that interactions in the lysosome are critical for cell death following sigma-2 ligand treatment because selective inhibition of a protective lysosomal membrane glycoprotein, LAMP1, with shRNA greatly reduced the viability of cells following treatment. Sigma-2 ligands induced lysosomal membrane permeabilization (LMP and protease translocation triggering downstream effectors of apoptosis. Subsequently, cellular oxidative stress was greatly increased following treatment with SW43, and the hydrophilic antioxidant N-acetylcysteine (NAC gave greater protection against this than a lipophilic antioxidant, α-tocopherol (α-toco. Conversely, PB282-mediated cytotoxicity relied less on cellular oxidation, even though α-toco did provide protection from this ligand. In addition, we found that caspase-3 induction was not as significantly inhibited by cathepsin inhibitors as by antioxidants. Both NAC and α-toco protected against caspase-3 induction following PB282 treatment, while only NAC offered protection following SW43 treatment. The caspase-3 inhibitor DEVD-FMK offered significant protection from PB282, but not SW43. Conclusions Sigma-2 ligand SW43 commits pancreatic cancer cells to death by a caspase-independent process involving LMP and oxidative stress which is protected from by NAC. PB282 however undergoes a

  4. Cytosol cathepsin-D content and proliferative activity of human breast cancer. The Comitato Italiano per il Controllo di Qualita del Laboratorio in Oncologia.

    Science.gov (United States)

    Paradiso, A; Mangia, A; Correale, M; Abbate, I; Ferri, G; Piffanelli, A; Catozzi, L; Amadori, D; Riccobon, A; De Lena, M

    1992-01-01

    Mitogenic properties have been demonstrated in vitro for the lysosomal acidic protease cathepsin-D (cath-D). We investigated possible relationships between cath-D cytosol cell content and tumor proliferative activity in a series of 129 operable breast cancer patients. For total cytosol cath-D evaluation, a solid phase two-site immunoradiometric assay was utilized on tumor cell cytosol obtained for hormone receptor assay (DCC method). The percentage of S-phase cells was analyzed by 3H-thymidine autoradiographic assay. Median 3H-thymidine Labeling Index (3H-Tdr-LI) of the series was 2.7%; median cath-D content resulted 57 pmol/mg of protein cytosol and was significantly higher in node-positive with respect to the node-negative subgroup (p < 0.03). When classified in low, intermediate or high tumor cath-D content and slow or fast proliferative activity (cut-off: median values of the series), no significant agreement was found between the two variables. Statistical analysis, however, showed that a significant inverse correlation existed in node positive tumors between cath-D and 3H-Tdr-LI values which was even more evident in N-positive high estrogen receptor-positive (ER+) cases (coefficient of correlation = 0.6828; p = 0.0001). Cytosol cath-D content cannot be generally proposed as a direct marker of proliferative activity for operable breast cancer.

  5. Lysosome Biogenesis and Autophagy

    NARCIS (Netherlands)

    Reggiori, Fulvio; Klumperman, Judith|info:eu-repo/dai/nl/075097273

    2016-01-01

    Lysosomes degrade biological components acquired by endocytosis, the major cellular pathway for internalization of extracellular material, and macroautophagy. This chapter presents an overview of these two major degradative intracellular pathways, and highlights the emerging cross talks between

  6. Region-specific changes in activities of cell death-related proteases and nitric oxide metabolism in rat brain in a chronic unpredictable stress model.

    Science.gov (United States)

    Tishkina, Anna; Rukhlenko, Alexey; Stepanichev, Mikhail; Levshina, Irina; Pasikova, Natalia; Onufriev, Mikhail; Moiseeva, Yulia; Piskunov, Alexey; Gulyaeva, Natalia

    2012-12-01

    Effects of a chronic combined unpredictable stress on activities of two cell death-related proteases, calpain and cathepsin B, were studied along with indices of nitrergic system in rat brain structures. Male Wistar rats were subjected to a 2-week-long combined stress (combination of unpaired flash light and moderate footshock associated with a white noise session). Stress resulted in a significant loss in the body and thymus weight and increased defecation in the open field test, though neither motor and exploratory activity, nor plasma corticosterone differed from the respective control levels. Decreased calpain activity and increased cathepsin B activity were demonstrated in the hippocampus of stressed rats (previously we have shown that caspase-3 activity was significantly suppressed in the brain of rats subjected to same type of stress). A significant reduction in the number of NOS-containing neurons was accompanied by a chronic stressinduced decline in NOS activity in the neocortex. Similar changes were observed in the hippocampus. However, levels of NO metabolites were elevated in both structures. Thus, stress-induced structural modifications in the brain may be mediated by disturbances in the nitrergic system and increased lysosomal proteolysis.

  7. A cardinal role for cathepsin d in co-ordinating the host-mediated apoptosis of macrophages and killing of pneumococci.

    Directory of Open Access Journals (Sweden)

    Martin A Bewley

    2011-01-01

    Full Text Available The bactericidal function of macrophages against pneumococci is enhanced by their apoptotic demise, which is controlled by the anti-apoptotic protein Mcl-1. Here, we show that lysosomal membrane permeabilization (LMP and cytosolic translocation of activated cathepsin D occur prior to activation of a mitochondrial pathway of macrophage apoptosis. Pharmacological inhibition or knockout of cathepsin D during pneumococcal infection blocked macrophage apoptosis. As a result of cathepsin D activation, Mcl-1 interacted with its ubiquitin ligase Mule and expression declined. Inhibition of cathepsin D had no effect on early bacterial killing but inhibited the late phase of apoptosis-associated killing of pneumococci in vitro. Mice bearing a cathepsin D(-/- hematopoietic system demonstrated reduced macrophage apoptosis in vivo, with decreased clearance of pneumococci and enhanced recruitment of neutrophils to control pulmonary infection. These findings establish an unexpected role for a cathepsin D-mediated lysosomal pathway of apoptosis in pulmonary host defense and underscore the importance of apoptosis-associated microbial killing to macrophage function.

  8. Nuclear cathepsin D enhances TRPS1 transcriptional repressor function to regulate cell cycle progression and transformation in human breast cancer cells.

    Science.gov (United States)

    Bach, Anne-Sophie; Derocq, Danielle; Laurent-Matha, Valérie; Montcourrier, Philippe; Sebti, Salwa; Orsetti, Béatrice; Theillet, Charles; Gongora, Céline; Pattingre, Sophie; Ibing, Eva; Roger, Pascal; Linares, Laetitia K; Reinheckel, Thomas; Meurice, Guillaume; Kaiser, Frank J; Gespach, Christian; Liaudet-Coopman, Emmanuelle

    2015-09-29

    The lysosomal protease cathepsin D (Cath-D) is overproduced in breast cancer cells (BCC) and supports tumor growth and metastasis formation. Here, we describe the mechanism whereby Cath-D is accumulated in the nucleus of ERα-positive (ER+) BCC. We identified TRPS1 (tricho-rhino-phalangeal-syndrome 1), a repressor of GATA-mediated transcription, and BAT3 (Scythe/BAG6), a nucleo-cytoplasmic shuttling chaperone protein, as new Cath-D-interacting nuclear proteins. Cath-D binds to BAT3 in ER+ BCC and they partially co-localize at the surface of lysosomes and in the nucleus. BAT3 silencing inhibits Cath-D accumulation in the nucleus, indicating that Cath-D nuclear targeting is controlled by BAT3. Fully mature Cath-D also binds to full-length TRPS1 and they co-localize in the nucleus of ER+ BCC where they are associated with chromatin. Using the LexA-VP16 fusion co-activator reporter assay, we then show that Cath-D acts as a transcriptional repressor, independently of its catalytic activity. Moreover, microarray analysis of BCC in which Cath-D and/or TRPS1 expression were silenced indicated that Cath-D enhances TRPS1-mediated repression of several TRPS1-regulated genes implicated in carcinogenesis, including PTHrP, a canonical TRPS1 gene target. In addition, co-silencing of TRPS1 and Cath-D in BCC affects the transcription of cell cycle, proliferation and transformation genes, and impairs cell cycle progression and soft agar colony formation. These findings indicate that Cath-D acts as a nuclear transcriptional cofactor of TRPS1 to regulate ER+ BCC proliferation and transformation in a non-proteolytic manner.

  9. Proteases in Periodontal Disease

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    Ana Rita Sokolonski ANTON

    2006-09-01

    Full Text Available Introduction: The caries and the periodontal disease (PD are the most frequent alterations in the oral cavity. The PD presents two stages: gengivitis and periodontitis. The destruction of collagenous fibers which encases the tooth onto the alveolar bone is characteristic of the pariodontitis. The inclusion loss caused by this pathology is due to the presence of bacteria and their products, besides the tissue destruction. This process is caused by excessive discharge of cells of the organism defence which reach the damaged area, and among these cells are neutrophils. These cells free lysosomal granule, where enzymes known as proteases (elastase, colagenasis and catepsin G are present. When excessively delivered, they cause extensive tissue destruction. The organism innate defence respond to this process activating anti-proteases, such as alfa-1-antitripsin e alfa-2-macrogoblulin, and, as consequence, the inflammatory process is subdued. Objective: Revision of the literature on periodontitis and its markers. In periodontitis, the balance between protease and anti-protese seems to be altered and lead to the appearance of these ones. There is an increase of prevalence of PD in the world population. In recent times, it has been associated to systemic conditions that lead to tissue destruction. Perhaps, the cause is based on an exacerbated tissue reaction, more than on the bacterial aggression. Conclusion: The predisposition of the organism is an important factor for the disease development. At reading different studies, it was observed that the discharged protease during the neutrophils degranulation process has internal, not bacterial, origin.

  10. Coronavirus cell entry occurs through the endo-/lysosomal pathway in a proteolysis-dependent manner.

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    Christine Burkard

    2014-11-01

    Full Text Available Enveloped viruses need to fuse with a host cell membrane in order to deliver their genome into the host cell. While some viruses fuse with the plasma membrane, many viruses are endocytosed prior to fusion. Specific cues in the endosomal microenvironment induce conformational changes in the viral fusion proteins leading to viral and host membrane fusion. In the present study we investigated the entry of coronaviruses (CoVs. Using siRNA gene silencing, we found that proteins known to be important for late endosomal maturation and endosome-lysosome fusion profoundly promote infection of cells with mouse hepatitis coronavirus (MHV. Using recombinant MHVs expressing reporter genes as well as a novel, replication-independent fusion assay we confirmed the importance of clathrin-mediated endocytosis and demonstrated that trafficking of MHV to lysosomes is required for fusion and productive entry to occur. Nevertheless, MHV was shown to be less sensitive to perturbation of endosomal pH than vesicular stomatitis virus and influenza A virus, which fuse in early and late endosomes, respectively. Our results indicate that entry of MHV depends on proteolytic processing of its fusion protein S by lysosomal proteases. Fusion of MHV was severely inhibited by a pan-lysosomal protease inhibitor, while trafficking of MHV to lysosomes and processing by lysosomal proteases was no longer required when a furin cleavage site was introduced in the S protein immediately upstream of the fusion peptide. Also entry of feline CoV was shown to depend on trafficking to lysosomes and processing by lysosomal proteases. In contrast, MERS-CoV, which contains a minimal furin cleavage site just upstream of the fusion peptide, was negatively affected by inhibition of furin, but not of lysosomal proteases. We conclude that a proteolytic cleavage site in the CoV S protein directly upstream of the fusion peptide is an essential determinant of the intracellular site of fusion.

  11. Coronavirus cell entry occurs through the endo-/lysosomal pathway in a proteolysis-dependent manner.

    Science.gov (United States)

    Burkard, Christine; Verheije, Monique H; Wicht, Oliver; van Kasteren, Sander I; van Kuppeveld, Frank J; Haagmans, Bart L; Pelkmans, Lucas; Rottier, Peter J M; Bosch, Berend Jan; de Haan, Cornelis A M

    2014-11-01

    Enveloped viruses need to fuse with a host cell membrane in order to deliver their genome into the host cell. While some viruses fuse with the plasma membrane, many viruses are endocytosed prior to fusion. Specific cues in the endosomal microenvironment induce conformational changes in the viral fusion proteins leading to viral and host membrane fusion. In the present study we investigated the entry of coronaviruses (CoVs). Using siRNA gene silencing, we found that proteins known to be important for late endosomal maturation and endosome-lysosome fusion profoundly promote infection of cells with mouse hepatitis coronavirus (MHV). Using recombinant MHVs expressing reporter genes as well as a novel, replication-independent fusion assay we confirmed the importance of clathrin-mediated endocytosis and demonstrated that trafficking of MHV to lysosomes is required for fusion and productive entry to occur. Nevertheless, MHV was shown to be less sensitive to perturbation of endosomal pH than vesicular stomatitis virus and influenza A virus, which fuse in early and late endosomes, respectively. Our results indicate that entry of MHV depends on proteolytic processing of its fusion protein S by lysosomal proteases. Fusion of MHV was severely inhibited by a pan-lysosomal protease inhibitor, while trafficking of MHV to lysosomes and processing by lysosomal proteases was no longer required when a furin cleavage site was introduced in the S protein immediately upstream of the fusion peptide. Also entry of feline CoV was shown to depend on trafficking to lysosomes and processing by lysosomal proteases. In contrast, MERS-CoV, which contains a minimal furin cleavage site just upstream of the fusion peptide, was negatively affected by inhibition of furin, but not of lysosomal proteases. We conclude that a proteolytic cleavage site in the CoV S protein directly upstream of the fusion peptide is an essential determinant of the intracellular site of fusion.

  12. The secretion of high molecular weight cathepsin B from cultured human liver cancers.

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    Ohsawa,Toshiya

    1989-02-01

    Full Text Available The biochemical characteristics of cathepsin B secreted from cultured human liver cancer cells were examined. The enzyme activity of culture medium against a synthetic substrate, N-carbobenzoxy-L-arginyl-L-arginine-4-methyl-coumaryl-7-amide, was dependent on the addition of cysteine, and the optimal pH was found to be 6.0. No activity was observed when the enzyme source was fresh medium not used for culture. These results suggest that the enzyme released from liver cancer cells is the thiol-protease cathepsin B. The molecular weight of the enzyme with 90% of the total activity was 40,000. Two cathepsin B molecules were found in liver tissue from patients with hepatocellular carcinoma (HCC; one was equivalent in size to the secreted enzyme, and a smaller one was the same as normal liver cathepsin B (27,000, which was also obtained from HCC-bearing cirrhotic liver. These results demonstrate that two molecules of cathepsin B are synthesized in liver cancer, and that the larger one is released into the surrounding tissue.

  13. The inactivation of the sortilin gene leads to a partial disruption of prosaposin trafficking to the lysosomes

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Jibin; Racicott, Jesse [Department of Anatomy and Cell Biology, McGill University, Montreal (Canada); Morales, Carlos R., E-mail: carlos.morales@mcgill.ca [Department of Anatomy and Cell Biology, McGill University, Montreal (Canada)

    2009-11-01

    Lysosomes are intracellular organelles which contain enzymes and activator proteins involved in the digestion and recycling of a variety of cellular and extracellular substances. We have identified a novel sorting receptor, sortilin, which is involved in the lysosomal trafficking of the sphingolipid activator proteins, prosaposin and GM{sub 2}AP, and the soluble hydrolases cathepsin D, cathepsin H, and acid sphingomyelinase. Sortilin belongs to a growing family of receptors with homology to the yeast Vps10 protein, which acts as a lysosomal sorting receptor for carboxypeptidase Y. In this study we examined the effects of the sortilin gene inactivation in mice. The inactivation of this gene did not yield any noticeable lysosomal pathology. To determine the existence of an alternative receptor complementing the sorting function of sortilin, we quantified the concentration of prosaposin in the lysosomes of the nonciliated epithelial cells lining the efferent ducts. These cells were chosen because they express sortilin and have a large number of lysosomes containing prosaposin. In addition, the nonciliated cells are known to endocytose luminal prosaposin that is synthesized and secreted by Sertoli cells into the seminiferous luminal fluids. Consequently, the nonciliated cells are capable of targeting both exogenous and endogenous prosaposin to the lysosomes. Using electron microscope immunogold labeling and quantitative analysis, our results demonstrate that inactivation of the sortilin gene produces a significant decrease of prosaposin in the lysosomes. When luminal prosaposin was excluded from the efferent ducts, the level of prosaposin in lysosomes was even lower in the mutant mice. Nonetheless, a significant amount of prosaposin continues to reach the lysosomal compartment. These results strongly suggest the existence of an alternative receptor that complements the function of sortilin and explains the lack of lysosomal storage disorders in the sortilin

  14. Calpains mediate epithelial-cell death during mammary gland involution: mitochondria and lysosomal destabilization.

    Science.gov (United States)

    Arnandis, T; Ferrer-Vicens, I; García-Trevijano, E R; Miralles, V J; García, C; Torres, L; Viña, J R; Zaragozá, R

    2012-09-01

    Our aim was to elucidate the physiological role of calpains (CAPN) in mammary gland involution. Both CAPN-1 and -2 were induced after weaning and its activity increased in isolated mitochondria and lysosomes. CAPN activation within the mitochondria could trigger the release of cytochrome c and other pro-apoptotic factors, whereas in lysosomes it might be essential for tissue remodeling by releasing cathepsins into the cytosol. Immunohistochemical analysis localized CAPNs mainly at the luminal side of alveoli. During weaning, CAPNs translocate to the lysosomes processing membrane proteins. To identify these substrates, lysosomal fractions were treated with recombinant CAPN and cleaved products were identified by 2D-DIGE. The subunit b(2) of the v-type H(+) ATPase is proteolyzed and so is the lysosomal-associated membrane protein 2a (LAMP2a). Both proteins are also cleaved in vivo. Furthermore, LAMP2a cleavage was confirmed in vitro by addition of CAPNs to isolated lysosomes and several CAPN inhibitors prevented it. Finally, in vivo inhibition of CAPN1 in 72-h-weaned mice decreased LAMP2a cleavage. Indeed, calpeptin-treated mice showed a substantial delay in tissue remodeling and involution of the mammary gland. These results suggest that CAPNs are responsible for mitochondrial and lysosomal membrane permeabilization, supporting the idea that lysosomal-mediated cell death is a new hallmark of mammary gland involution.

  15. [Lysosomal proteinasen and peptidasen in serum of children with inflammatory diseases (author's transl)].

    Science.gov (United States)

    Appel, W; Huth, E; Herrmann, H

    1976-08-01

    In the serum of 43 children the activities of proteinases and peptidases by mean of 41 substrates have been determined in order to get knowledge of overall activities and differentiation of lysosomal proteolytic enzymes. Proteinases, cathepsins A, B, C and D, aminopeptidases, carboxypeptidases, dipeptidases, tripeptidases and aminoacidarylamidases have been checked. The enzyme pattern of the serum of a collective of 15 healthy children or those without serious clinical signs is demonstrated, also the alterations and differentiations in the serum of children with leucemia, pneumonia, inflammatory diseases of the respiratory tract, other inflammatory diseases and common diseases. Leucyl-glycyl-glycyltripeptidase, glycyl-glycyl-glycyltripeptidase, a proteosterase, carboxypeptidase A, a neutrale proteinase and basic proteinase (cathepsin B) and cathepsin C are increased. A distinct elevation has been found only in children with leucemia and pneumonia.

  16. Fungal protease.

    NARCIS (Netherlands)

    Buxton, F.; Jarai, G.; Visser, J.

    1994-01-01

    The present invention concerns a novel DNA sequence coding for an Aspergillus aspartic protease, an Aspergillus aspartic protease per se and a method for the preparation thereof. The invention further concerns a novel Aspergillus mutant strain defective in a protease of the aspartic proteinase-type,

  17. The Structure and Function of Cathepsin L%组织蛋白酶L的结构与功能

    Institute of Scientific and Technical Information of China (English)

    杨东辉; 刘宇; 肖蓉; 李庆伟

    2012-01-01

    Cathepsin L ( CTSL) is a member of the lysosomal cysteine protease superfamily with an unique manner of synthesis and transportation. The precursor peptide of CTSL preproenzyme contains the ERF/WNIN motif and GNFD motif in the primary structure, and contains an L domain of a-helix and an R domain of p-sheet in the spatial structure. CTSL plays extremely important roles in physiological and pathological processes in human and parasitic animals. Its physiological roles are widely involved in proteolysis, antigen-presenting, T cell development, cell apoptosis, and embryonic development, etc. It is also related to the development of cancer, cardiovascular diseases and kidney diseases. In addition, CTSL plays a special role in parasitic animals. Here, we focused on the recent advances regarding this study.%组织蛋白酶L(cathepsin L,CTSL)是溶酶体半胱氨酸蛋白酶家族的主要成员,具有非常独特的合成和转运方式.CTSL前体酶原的前体肽含有ERF/WNIN模体和GNFD模体.CTSL的空间结构主要由α螺旋构成的L结构域以及由β折叠构成的R结构域组成.大量研究工作表明,CTSL在体内生理和病理过程中,以及在寄生动物中都发挥着极其重要的功能.其生理作用广泛涉及到蛋白质水解、抗原提呈、T细胞分选、细胞凋亡以及胚胎发育等方面.CTSL还与多种类型的肿瘤发生、心血管疾病以及肾病等密切相关.另外,CTSL在寄生动物中也发挥着独特的作用.本文针对CTST的最新研究进展做了简要总结及分析,并指出了相关研究的发展趋势.

  18. Visualization of ceramide channels in lysosomes following endogenous palmitoyl-ceramide accumulation as an initial step in the induction of necrosis

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    Mototeru Yamane

    2017-09-01

    Full Text Available In this study, we showed that the dual addition of glucosyl ceramide synthase and ceramidase inhibitors to A549 cell culture led to the possibility of ceramide channel formation via endogenous palmitoyl-ceramide accumulation with an increase in cholesterol contents in the lysosome membrane as an initial step prior to initiation of necrotic cell death. In addition, the dual addition led to black circular structures of 10–20 nm, interpreted as stain-filled cylindrical channels on transmission electron microscopy. The formation of palmitoyl-ceramide channels in the lysosome membrane causes the liberation of cathepsin B from lysosomes for necrotic cell death. On the other hand, necrotic cell death in the dual addition was not caused by oxidative stress or cathepsin B activity, and the cell death was free from the contribution of the translation of Bax protein to the lysosome membrane.

  19. Expression and Purification of Active Recombinant Cathepsin C (Dipeptidyl Aminopeptidase I of Kuruma Prawn Marsupenaeus japonicus in Insect Cells

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    Gao-Feng Qiu

    2009-01-01

    Full Text Available Cathepsin C (CTSC is a lysosomal cysteine protease belonging to the papain superfamily. Our previous study showed that CTSC precursor (zymogen is localized exclusively in cortical rods (CRs of mature oocyte in the kuruma prawn Marsupenaeus japonicus, suggesting that CTSC might have roles on regulating release and/or formation of a jelly layer. In this study, enzymically active CTSC of the kuruma prawn was prepared by recombinant expression in the High Five insect cell line. The recombinant enzyme with a polyhistidine tag at its C-terminus was considered to be initially secreted into the culture medium as an inactive form of zymogen, because Western blot with anti-CTSC antibody detected a 51 kDa protein corresponding to CTSC precursor. After purification by affinity chromatography on nickel-iminodiacetic acid resin, the enzyme displayed three forms of 51, 31, and 30 kDa polypeptides. All of the forms can be recognized by antiserum raised against C-terminal polyhistidine tag, indicating that the 31 and 30 kDa forms were generated from 51 kDa polypeptide by removal of a portion of the N-terminus of propeptide. Following activation at pH 5.5 and 37∘C for 40 hours under native conditions, the recombinant CTSC (rCTSC exhibited increased activity against the synthetic substrate Gly-Phe-β-naphthylamide and optimal pH at around 5. The purified rCTSC will be useful for further characterization of its exact physiological role on CRs release and/or formation of a jelly layer in kuruma prawn.

  20. Action of cathepsin D on fructose-1,6-bisphosphate aldolase.

    Science.gov (United States)

    Offermann, M K; Chlebowski, J F; Bond, J S

    1983-06-01

    Cathepsin D inactivated aldolase at pH values between 4.2 and 5.2; the chloride, sulphate or iodide, but not citrate or acetate, salts of sodium or potassium accelerated the rate of inactivation. Cathepsin D cleaved numerous peptide bonds in the C-terminus of aldolase, but the major site of cleavage in this region was Leu354-Phe355. The most prominent peptide products of hydrolysis were Phe-Ile-Ser-Asn-His-Ala-Tyr and Phe-Ile-Ser-Asn-His. Up to 20 amino acids were removed from the C-terminus of aldolase, but no further degradation of native aldolase was observed. By contrast, extensive degradation of the 40 000-Mr subunit was observed after aldolase was denatured. The cathepsin D-inactivated aldolase cross-reacted with antibodies prepared against native aldolase and had the same thermodynamic stability as native aldolase, demonstrated by differential scanning calorimetry and fluorescence quenching of tryptophan residues. Furthermore, the cathepsin-modified and native forms of aldolase were both resistant to extensive proteolysis by other purified cellular proteinases and lysosomal extracts at pH values of 4.8-8.0.

  1. Protease Inhibitors Targeting Coronavirus and Filovirus Entry

    Science.gov (United States)

    Zhou, Yanchen; Vedantham, Punitha; Lu, Kai; Agudelo, Juliet; Carrion, Ricardo; Nunneley, Jerritt W.; Barnard, Dale; Pöhlmann, Stefan; McKerrow, James H.; Renslo, Adam R.; Simmons, Graham

    2016-01-01

    In order to gain entry into cells, diverse viruses, including Ebola virus, SARS-coronavirus and the emerging MERS-coronavirus, depend on activation of their envelope glycoproteins by host cell proteases. The respective enzymes are thus excellent targets for antiviral intervention. In cell culture, activation of Ebola virus, as well as SARS- and MERS-coronavirus can be accomplished by the endosomal cysteine proteases, cathepsin L (CTSL) and cathepsin B (CTSB). In addition, SARS- and MERS-coronavirus can use serine proteases localized at the cell surface, for their activation. However, it is currently unclear which protease(s) facilitate viral spread in the infected host. We report here that the cysteine protease inhibitor K11777, ((2S)-N-[(1E,3S)-1-(benzenesulfonyl)-5-phenylpent-1-en-3-yl]-2-{[(E)-4-methylpiperazine-1-carbonyl]amino}-3-phenylpropanamide) and closely-related vinylsulfones act as broad-spectrum antivirals by targeting cathepsin-mediated cell entry. K11777 is already in advanced stages of development for a number of parasitic diseases, such as Chagas disease, and has proven to be safe and effective in a range of animal models. K11777 inhibition of SARS-CoV and Ebola virus entry was observed in the sub-nanomolar range. In order to assess, whether cysteine or serine proteases promote viral spread in the host, we compared the antiviral activity of an optimized K11777-derivative with that of camostat, an inhibitor of TMPRSS2 and related serine proteases. Employing a pathogenic animal model of SARS-CoV infection, we demonstrated that viral spread and pathogenesis of SARS-CoV is driven by serine rather than cysteine proteases and can be effectively prevented by camostat. Camostat has been clinically used to treat chronic pancreatitis, and thus represents an exciting potential therapeutic for respiratory coronavirus infections. Our results indicate that camostat, or similar serine protease inhibitors, might be an effective option for treatment of SARS and

  2. Frustrated phagocytosis on micro-patterned immune complexes to characterize lysosome movements in live macrophages.

    Directory of Open Access Journals (Sweden)

    Arnaud M. Labrousse

    2011-10-01

    Full Text Available Lysosome mobilization is a key cellular process in phagocytes for bactericidal activities and trans-matrix migration. The molecular mechanisms that regulate lysosome mobilization are still poorly known. Lysosomes are hard to track as they move towards phagosomes throughout the cell volume. In order to anticipate cell regions where lysosomes are recruited to, human and RAW264.7 macrophages were seeded on surfaces that were micro-patterned with immune complexes (ICs as 4 µm-side squares. Distances between IC patterns were adapted to optimize cell spreading in order to constrain lysosome movements mostly in 2 dimensions. Fc receptors triggered local frustrated phagocytosis, frustrated phagosomes appeared as rings of F-actin dots around the IC patterns as early as 5 minutes after cells made contact with the substratum. Frustrated phagosomes recruited actin-associated proteins (vinculin, paxillin and gelsolin. The fusion of lysosomes with frustrated phagosomes was shown by the release of beta-hexosaminidase and the recruitment of Lamp-1 to frustrated phagosomes. Lysosomes of RAW264.7 macrophages were labeled with cathepsinD-mCherry to visualize their movements towards frustrated phagosomes. Lysosomes saltatory movements were markedly slowed down compared to cells layered on non-opsonized patterns. In addition, the linearity of the trajectories and the frequency and duration of contacts of lysosomes with frustrated phagosomes were measured.¬¬¬¬¬¬¬¬ Using PP2 we showed that instant velocity, pauses and frequency of lysosome/phagosome contacts were at least in part dependent on Src tyrosine kinases. This experimental set-up is the first step towards deciphering molecular mechanisms which are involved in lysosome movements in the cytoplasm (directionality, docking and fusion using RNA interference, pharmacological inhibition or mutant expression.

  3. Processing Proteases

    DEFF Research Database (Denmark)

    Ødum, Anders Sebastian Rosenkrans

    Processing proteases are proteases which proteolytically activate proteins and peptides into their biologically active form. Processing proteases play an important role in biotechnology as tools in protein fusion technology. Fusion strategies where helper proteins or peptide tags are fused...... to the protein of interest are an elaborate method to optimize expression or purification systems. It is however critical that fusion proteins can be removed and processing proteases can facilitate this in a highly specific manner. The commonly used proteases all have substrate specificities to the N...... of few known proteases to have substrate specificity for the C-terminal side of the scissile bond. LysN exhibits specificity for lysine, and has primarily been used to complement trypsin in to proteomic studies. A working hypothesis during this study was the potential of LysN as a processing protease...

  4. Role of cathepsin A and cathepsin C in the regulation of glycosidase activity

    Directory of Open Access Journals (Sweden)

    Anna Justyna Milewska

    2012-04-01

    Full Text Available Increased tissue activity of cathepsin A and cathepsin C can be observed in many pathological conditions. It is associated with an enhanced degradation of glycosaminoglycans, proteoglycans, and glycoproteins, and results in their decreased tissue content. Cathepsin C releases the glycosidases from complexes formed with cathepsin A, and reinstates their activity. In this review a current state of knowledge is presented concerning the regulation of selected glycosidases activity by cathepsin A (EC 3.4.16.1 and C (EC 3.4.14.1.

  5. Chemoenzymatic synthesis of organoselenium(IV) compounds and their evaluation as cysteine protease inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Piovan, Leandro; Andrade, Leandro H., E-mail: leandroh@iq.usp.b [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Quimica; Alves, Marcio F.M.; Juliano, Luiz; Cunha, Rodrigo L.O.R, E-mail: rodrigo.cunha@ufabc.edu.b [Universidade Federal de Sao Paulo (Unifesp/EPM), Sao Paulo, SP (Brazil). Dept. de Biofisica; Broemme, Dieter [University of British Columbia, Vancouver (Canada). Dept. of Dentistry

    2010-07-01

    A series of organoselenium dihalides (organoselenanes) was synthesized from organoselenides using a chemoenzymatic approach. The organoselenanes have variations in their stereochemistry and in the halogen atom bonded to the selenium atom. Because of the unique selenium-thiol chemistry displayed by several organoselenium compounds, the organoselenanes were evaluated as new potential inhibitors of cysteine proteases (cathepsins S and V). By the analysis of the second-order rate constants of the inhibition of cathepsin S and V, it was possible to conclude that organoselenanes inhibited the cathepsin S faster than cathepsin V. It was observed higher inhibitory potencies for the dibromo organoselenanes derivatives than the dichloro analogues. In addition, the present data suggest the use of hypervalent selenium compounds as novel motifs for cysteine proteases inhibitors. (author)

  6. Serum cysteine proteases and their inhibitors in rheumatoid arthritis: relation to disease activity and radiographic progression

    DEFF Research Database (Denmark)

    Kos, Janko; Krašovec, Marta; Troelsen, Lone

    2011-01-01

    This study aims to investigate the serum levels of cysteine proteases cathepsins B and H and their inhibitors stefin A, stefin B, and cystatin C, as well as traditional inflammatory markers such as C-reactive protein in patients with rheumatoid arthritis and to correlate these markers with scores...... of disease activity and radiographic progression. Seventy-two patients with rheumatoid arthritis were included from two previously described cohorts of patients with chronic polyarthritis. At inclusion, disease activity was assessed by a 28-joint count, patient global assessment, and serum C-reactive protein....... Erosive status of hands and wrists was expressed by the Larsen score and recorded at inclusion and after 1 year. Serum levels of cathepsin B, cathepsin H, stefin A, stefin B, and cystatin C were determined by enzyme-linked immunosorbent assay. Neither cathepsin B nor cathepsin H serum levels were...

  7. Peptide aldehyde inhibitors of cathepsin K inhibit bone resorption both in vitro and in vivo.

    Science.gov (United States)

    Votta, B J; Levy, M A; Badger, A; Bradbeer, J; Dodds, R A; James, I E; Thompson, S; Bossard, M J; Carr, T; Connor, J R; Tomaszek, T A; Szewczuk, L; Drake, F H; Veber, D F; Gowen, M

    1997-09-01

    We have shown previously that cathepsin K, a recently identified member of the papain superfamily of cysteine proteases, is expressed selectively in osteoclasts and is the predominant cysteine protease in these cells. Based upon its abundant cell type-selective expression, potent endoprotease activity at low pH and cellular localization at the bone interface, cathepsin K has been proposed to play a specialized role in osteoclast-mediated bone resorption. In this study, we evaluated a series of peptide aldehydes and demonstrated that they are potent cathepsin K inhibitors. These compounds inhibited osteoclast-mediated bone resorption in fetal rat long bone (FRLB) organ cultures in vitro in a concentration-dependent manner. Selected compounds were also shown to inhibit bone resorption in a human osteoclast-mediated assay in vitro. Chz-Leu-Leu-Leu-H (in vitro enzyme inhibition Ki,app = 1.4 nM) inhibited parathyroid hormone (PTH)-stimulated resorption in the FRLB assay with an IC-50 of 20 nM and inhibited resorption by isolated human osteoclasts cultured on bovine cortical bone slices with an IC-50 of 100 nM. In the adjuvant-arthritic (AA) rat model, in situ hybridization studies demonstrated high levels of cathepsin K expression in osteoclasts at sites of extensive bone loss in the distal tibia. Cbz-Leu-Leu-Leu-H (30 mg/kg, intraperitoneally) significantly reduced this bone loss, as well as the associated hind paw edema. In the thyroparathyriodectomized rat model, Cbz-Leu-Leu-Leu-H inhibited the increase in blood ionized calcium induced by a 6 h infusion of PTH. These data indicate that inhibitors of cathepsin K are effective at reducing osteoclast-mediated bone resorption and may have therapeutic potential in diseases of excessive bone resorption such as rheumatoid arthritis or osteoporosis.

  8. Chlamydia species-dependent differences in the growth requirement for lysosomes.

    Directory of Open Access Journals (Sweden)

    Scot P Ouellette

    Full Text Available Genome reduction is a hallmark of obligate intracellular pathogens such as Chlamydia, where adaptation to intracellular growth has resulted in the elimination of genes encoding biosynthetic enzymes. Accordingly, chlamydiae rely heavily on the host cell for nutrients yet their specific source is unclear. Interestingly, chlamydiae grow within a pathogen-defined vacuole that is in close apposition to lysosomes. Metabolically-labeled uninfected host cell proteins were provided as an exogenous nutrient source to chlamydiae-infected cells, and uptake and subsequent labeling of chlamydiae suggested lysosomal degradation as a source of amino acids for the pathogen. Indeed, Bafilomycin A1 (BafA1, an inhibitor of the vacuolar H(+/ATPase that blocks lysosomal acidification and functions, impairs the growth of C. trachomatis and C. pneumoniae, and these effects are especially profound in C. pneumoniae. BafA1 induced the marked accumulation of material within the lysosomal lumen, which was due to the inhibition of proteolytic activities, and this response inhibits chlamydiae rather than changes in lysosomal acidification per se, as cathepsin inhibitors also inhibit the growth of chlamydiae. Finally, the addition of cycloheximide, an inhibitor of eukaryotic protein synthesis, compromises the ability of lysosomal inhibitors to block chlamydial growth, suggesting chlamydiae directly access free amino acids in the host cytosol as a preferred source of these nutrients. Thus, chlamydiae co-opt the functions of lysosomes to acquire essential amino acids.

  9. Macrobrachium rosenbergii cathepsin L: molecular characterization and gene expression in response to viral and bacterial infections.

    Science.gov (United States)

    Arockiaraj, Jesu; Gnanam, Annie J; Muthukrishnan, Dhanaraj; Thirumalai, Muthukumaresan Kuppusamy; Pasupuleti, Mukesh; Milton, James; Kasi, Marimuthu

    2013-11-07

    Cathepsin L (MrCathL) was identified from a constructed cDNA library of freshwater prawn Macrobrachium rosenbergii. MrCathL full-length cDNA is 1161 base pairs (bp) with an ORF of 1026bp which encodes a polypeptide of 342 amino acid (aa) long. The eukaryotic cysteine proteases, histidine and asparagine active site residues were identified in the aa sequence of MrCathL at 143-154, 286-296 and 304-323, respectively. The pair wise clustalW analysis of MrCathL showed the highest similarity (97%) with the homologous cathepsin L from Macrobrachium nipponense and the lowest similarity (70%) from human. Phylogenetic analysis revealed two distinct clusters of the invertebrates and vertebrates cathepsin L in the phylogenetic tree. MrCathL and cathepsin L from M. nipponense were clustered together, formed a sister group to cathepsin L of Penaeus monodon, and finally clustered to Lepeophtheirus salmonis. High level of (Prosenbergii was up-regulated in haemocyte by virus [M. rosenbergii nodovirus (MrNV) and white spot syndrome baculovirus (WSBV)] and bacteria (Vibrio harveyi and Aeromonas hydrophila). The recombinant MrCathL exhibited a wide range of activity in various pH between 3 and 10 and highest at pH 7.5. Cysteine proteinase (stefin A, stefin B and antipain) showed significant influence (100%) on recombinant MrCathL enzyme activity. The relative activity and residual activity of recombinant MrCathL against various metal ions or salts and detergent tested at different concentrations. These results indicated that the metal ions, salts and detergent had an influence on the proteinase activity of recombinant MrCathL. Conclusively, the results of this study imply that MrCathL has high pH stability and is fascinating object for further research on the function of cathepsin L in prawn innate immune system.

  10. Preventive effects of p-coumaric acid on lysosomal dysfunction and myocardial infarct size in experimentally induced myocardial infarction.

    Science.gov (United States)

    Jyoti Roy, Abhro; Stanely Mainzen Prince, P

    2013-01-15

    The present study was designed to evaluate the preventive effects of p-coumaric acid on lysosomal dysfunction and myocardial infarct size in isoproterenol induced myocardial infarcted rats. Male albino Wistar rats were pretreated with p-coumaric acid (8 mg/kg body weight) daily for a period of 7 days after which isoproterenol (100mg/kg body weight) was injected subcutaneously into rats twice at an interval of 24h (8th and 9th day).The activity/levels of serum cardiac diagnostic markers, heart lysosomal lipid peroxidation products and the activities of lysosomal enzymes (β-glucuronidase, β-galactosidase, cathepsin-B and cathepsin-D) were significantly (Plysosomal fraction. The pretreatment with p-coumaric acid significantly (Plysosomal lipid peroxidation products and the activities of lysosomal enzymes. In addition, p-coumaric acid greatly reduced myocardial infarct size. p-Coumaric acid pretreatment (8 mg/kg body weight) to normal rats did not show any significant effect. Thus, this study showed that p-coumaric acid prevents lysosomal dysfunction against cardiac damage induced by isoproterenol and brings back the levels of lipid peroxidation products and activities of lysosomal enzymes to near normal levels. The in vitro study also revealed the free radical scavenging activity of p-coumaric acid. Thus, the observed effects are due to p-coumaric acid's free radical scavenging and membrane stabilizing properties.

  11. Evidence for lysosomal exocytosis and release of aggrecan-degrading hydrolases from hypertrophic chondrocytes, in vitro and in vivo

    Directory of Open Access Journals (Sweden)

    Edward R. Bastow

    2012-02-01

    The abundant proteoglycan, aggrecan, is resorbed from growth plate cartilage during endochondral bone ossification, yet mice with genetically-ablated aggrecan-degrading activity have no defects in bone formation. To account for this apparent anomaly, we propose that lysosomal hydrolases degrade extracellular, hyaluronan-bound aggrecan aggregates in growth plate cartilage, and that lysosomal hydrolases are released from hypertrophic chondrocytes into growth plate cartilage via Ca2+-dependent lysosomal exocytosis. In this study we confirm that hypertrophic chondrocytes release hydrolases via lysosomal exocytosis in vitro and we show in vivo evidence for lysosomal exocytosis in hypertrophic chondrocytes during skeletal development. We show that lysosome-associated membrane protein 1 (LAMP1 is detected at the cell surface following in vitro treatment of epiphyseal chondrocytes with the calcium ionophore, ionomycin. Furthermore, we show that in addition to the lysosomal exocytosis markers, cathepsin D and β-hexosaminidase, ionomycin induces release of aggrecan- and hyaluronan-degrading activity from cultured epiphyseal chondrocytes. We identify VAMP-8 and VAMP7 as v-SNARE proteins with potential roles in lysosomal exocytosis in hypertrophic chondrocytes, based on their colocalisation with LAMP1 at the cell surface in secondary ossification centers in mouse tibiae. We propose that resorbing growth plate cartilage involves release of destructive hydrolases from hypertrophic chondrocytes, via lysosomal exocytosis.

  12. Glucagon-like Peptide-1 Protects Pancreatic Beta-cells from Death by Increasing Autophagic Flux and Restoring Lysosomal Function.

    Science.gov (United States)

    Zummo, Francesco P; Cullen, Kirsty S; Honkanen-Scott, Minna; Shaw, James Am; Lovat, Penny E; Arden, Catherine

    2017-02-23

    Studies in animal models of type 2 diabetes have shown that glucagon-like peptide-1 (GLP-1) receptor agonists prevent β-cell loss. Whether GLP-1 mediates β-cell survival via the key lysosomal-mediated process of autophagy is unknown.Here we report that treatment of INS-1E β-cells and primary islets with glucolipotoxicity (0.5mmol/l palmitate, 25mmol/l glucose) increases LC3 II, a marker of autophagy. Further analysis indicates a blockage in autophagic flux associated with lysosomal dysfunction. Accumulation of defective lysosomes leads to lysosomal membrane permeabilisation (LMP) and release of Cathepsin D, which contributes to cell death. Our data further demonstrated defects in autophagic flux and lysosomal staining in human samples of type 2 diabetes. Co-treatment with the GLP-1 receptor agonist exendin-4 reversed the lysosomal dysfunction, relieving the impairment in autophagic flux and further stimulated autophagy. siRNA knockdown showed the restoration of autophagic flux is also essential for the protective effects of exendin-4.Collectively, our data highlights lysosomal dysfunction as a critical mediator of β-cell loss and shows that exendin-4 improves cell survival via restoration of lysosomal function and autophagic flux. Modulation of autophagy / lysosomal homeostasis may thus define a novel therapeutic strategy for type 2 diabetes, with the GLP-1 signalling pathway as a potential focus.

  13. Monoclonal antibody against recombinant Fasciola gigantica cathepsin L1H could detect juvenile and adult cathepsin Ls of Fasciola gigantica.

    Science.gov (United States)

    Wongwairot, Sirima; Kueakhai, Pornanan; Changklungmoa, Narin; Jaikua, Wipaphorn; Sansri, Veerawat; Meemon, Krai; Songkoomkrong, Sineenart; Riengrojpitak, Suda; Sobhon, Prasert

    2015-01-01

    Cathepsin Ls (CatLs), the major cysteine protease secreted by Fasciola spp., are important for parasite digestion and tissue invasion. Fasciola gigantica cathepsin L1H (FgCatL1H) is the isotype expressed in the early stages for migration and invasion. In the present study, a monoclonal antibody (MoAb) against recombinant F. gigantica cathepsin L1H (rFgCatL1H) was produced by hybridoma technique using spleen cells from BALB/c mice immunized with recombinant proFgCatL1H (rproFgCatL1H). This MoAb is an immunoglobulin (Ig)G1 with κ light chain isotype. The MoAb reacted specifically with rproFgCatL1H, the native FgCatL1H at a molecular weight (MW) 38 to 48 kDa in the extract of whole body (WB) of metacercariae and newly excysted juvenile (NEJ) and cross-reacted with rFgCatL1 and native FgCatLs at MW 25 to 28 kDa in WB of 2- and 4-week-old juveniles, adult, and adult excretory-secretory (ES) fractions by immunoblotting and indirect ELISA. It did not cross-react with antigens in WB fractions from other parasites, including Gigantocotyle explanatum, Paramphistomum cervi, Gastrothylax crumenifer, Eurytrema pancreaticum, Setaria labiato-papillosa, and Fischoederius cobboldi. By immunolocalization, MoAb against rFgCatL1H reacted with the native protein in the gut of metacercariae and NEJ and also cross-reacted with CatL1 in 2- and 4-week-old juveniles and adult F. gigantica. Therefore, FgCatL1H and its MoAb may be used for immunodiagnosis of both early and late fasciolosis in ruminants and humans.

  14. Metallothionein-3 regulates lysosomal function in cultured astrocytes under both normal and oxidative conditions.

    Science.gov (United States)

    Lee, Sook-Jeong; Park, Mi-Ha; Kim, Hyun-Jae; Koh, Jae-Young

    2010-08-01

    Cellular zinc plays a key role in lysosomal change and cell death in neurons and astrocytes under oxidative stress. Here, using astrocytes lacking metallothionein-3 (MT3), a potential source of labile zinc in the brain, we studied the role of MT3 in oxidative stress responses. H(2)O(2) induced a large increase in labile zinc in wild-type (WT) astrocytes, but stimulated only a modest rise in MT3-null astrocytes. In addition, H(2)O(2)-induced lysosomal membrane permeabilization (LMP) and cell death were comparably attenuated in MT3-null astrocytes. Expression and glycosylation of Lamp1 (lysosome-associated membrane protein 1) and Lamp2 were increased in MT3-null astrocytes, and the activities of several lysosomal enzymes were significantly reduced, indicating an effect of MT3 on lysosomal components. Consistent with lysosomal dysfunction in MT3-null cells, the level of LC3-II (microtubule-associated protein 1 light chain 3), a marker of early autophagy, was increased by oxidative stress in WT astrocytes, but not in MT3-null cells. Similar changes in Lamp1, LC3, and cathepsin-D were induced by the lysosomal inhibitors bafilomycin A1, chloroquine, and monensin, indicating that lysosomal dysfunction may lie upstream of changes observed in MT3-null astrocytes. Consistent with this idea, lysosomal accumulation of cholesterol and lipofuscin were augmented in MT3-null astrocytes. Similar to the results seen in MT3-null cells, MT3 knockdown by siRNA inhibited oxidative stress-induced increases in zinc and LMP. These results indicate that MT3 may play a key role in normal lysosomal function in cultured astrocytes.

  15. Evaluation of flavonols and derivatives as human cathepsin B inhibitor.

    Science.gov (United States)

    Ramalho, Suelem D; de Sousa, Lorena R F; Burger, Marcela C M; Lima, Maria Inês S; da Silva, M Fátima das G F; Fernandes, João B; Vieira, Paulo C

    2015-01-01

    Cathepsin B (catB) is a cysteine protease involved in tumour progression and represents a potential therapeutic target in cancer. Among the 15 evaluated extracts from cerrado biome, Myrcia lingua Berg. (Myrtaceae) extract demonstrated to be a source of compounds with potential to inhibit catB. Using bioactivity-guided fractionation, we have found flavonols as inhibitors and also some other derivatives were obtained. From the evaluated compounds, myricetin (5) and quercetin (6) showed the most promising results with IC50 of 4.9 and 8.2 μM, respectively, and mode of inhibition as uncompetitive on catB. The results demonstrated polyhydroxylated flavonols as promising inhibitors of catB.

  16. Non-invasive imaging of cysteine cathepsin activity in solid tumors using a 64Cu-labeled activity-based probe.

    Directory of Open Access Journals (Sweden)

    Gang Ren

    Full Text Available The papain family of cysteine cathepsins are actively involved in multiple stages of tumorigenesis. Because elevated cathepsin activity can be found in many types of human cancers, they are promising biomarkers that can be used to target radiological contrast agents for tumor detection. However, currently there are no radiological imaging agents available for these important molecular targets. We report here the development of positron emission tomography (PET radionuclide-labeled probes that target the cysteine cathepsins by formation of an enzyme activity-dependent bond with the active site cysteine. These probes contain an acyloxymethyl ketone (AOMK functional group that irreversibly labels the active site cysteine of papain family proteases attached to a 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA tag for labeling with (64Cu for PET imaging studies. We performed biodistribution and microPET imaging studies in nude mice bearing subcutaneous tumors expressing various levels of cysteine cathepsin activity and found that the extent of probe uptake by tumors correlated with overall protease activity as measured by biochemical methods. Furthermore, probe signals could be reduced by pre-treatment with a general cathepsin inhibitor. We also found that inclusion of a Cy5 tag on the probe increased tumor uptake relative to probes lacking this fluorogenic dye. Overall, these results demonstrate that small molecule activity-based probes carrying radio-tracers can be used to image protease activity in living subjects.

  17. Lysosomal membrane permeabilization is involved in oxidative stress-induced apoptotic cell death in LAMP2-deficient iPSCs-derived cerebral cortical neurons

    Directory of Open Access Journals (Sweden)

    Cheuk-Yiu Law

    2016-03-01

    Our results from cellular fractionation and inhibitor blockade experiments further revealed that oxidative stress-induced apoptosis in the LAMP2-deficient cortical neurons was caused by increased abundance of cytosolic cathepsin L. These results suggest the involvement of lysosomal membrane permeabilization in the LAMP2 deficiency associated neural injury.

  18. Inhibitors of cysteine cathepsin and calpain do not prevent ultraviolet-B-induced apoptosis in human keratinocytes and HeLa cells

    DEFF Research Database (Denmark)

    Bang, Bo; Baadsgaard, Ole; Skov, Lone

    2004-01-01

    Caspases, members of the cysteine protease family, execute UVB-induced apoptosis in several cell lines and keratinocytes. Several researchers investigating UVB-induced apoptosis have demonstrated a dose-dependent protective effect of the synthetic peptide caspase inhibitor zVAD-fmk. However, z......VAD-fmk displays a dose-dependent protective effect against UVB-induced apoptosis, even at doses higher than those required to block all known proapoptotic caspases. In addition, it is known that zVAD-fmk also inhibits other cysteine proteases including cathepsins and calpains, and these proteases have recently....... This was done by investigating the effect of the irreversible cysteine protease inhibitor zFA-fmk, the cathepsin B inhibitor CA-074-Me and the calpain inhibitor ALLN on the viability of UVB-irradiated human keratinocytes and HeLa cells. At concentrations of 10 microM and above zVAD-fmk conferred partial dose...

  19. Some observations on the subfibrillar structure of collagen fibrils as noted during treatment with NKISK and cathepsin G with mechanical agitation.

    Science.gov (United States)

    Zhao, Tailun; Weinhold, Paul S; Lee, Nicole Y; Dahners, Laurence E

    2011-01-01

    We observed the structure of collagen fibrils in rat tail tendons after treatment with NKISK and cathepsin G. NKISK is a pentapeptide that has been previously shown to bind fibronectin, while cathepsin G is a serine protease that cleaves fibronectin but not type I collagen. In tendons treated with NKISK, fibrils were seen to extensively dissociate into smaller-diameter subfibrils. These subfibrils were homogeneous in diameter with an average diameter of 26.3 ± 5.8 nm. Similar, although less extensive, dissociation into subfibrils was found in tendons treated with cathepsin G. The average diameter of these subfibrils was 24.8 ± 4.9 nm. The ability of NKISK and cathepsin G to release subfibrils at physiological pH without harsh denaturants may enhance the study of the subfibrillar structure of collagen fibrils.

  20. Protease inhibitor

    DEFF Research Database (Denmark)

    2009-01-01

    The present invention relates to a polypeptide exhibiting a protease inhibitory activity and uses of said polypeptide in methods for inhibiting, directly or indirectly, one or more proteases of the blood clotting cascade. The invention also relates to use of said polypeptide as a pharmaceutical e...

  1. Cathepsin D SNP associated with increased risk of variant Creutzfeldt-Jakob disease

    Directory of Open Access Journals (Sweden)

    Sanchez-Juan Pascual

    2008-04-01

    Full Text Available Abstract Background Variant Creutzfeldt-Jakob disease (vCJD originally resulted from the consumption of foodstuffs contaminated by bovine spongiform encephalopathy (BSE material, with 163 confirmed cases in the UK to date. Many thousands are likely to have been exposed to dietary infection and so it is important (for surveillance, epidemic modelling, public health and understanding pathogenesis to identify genetic factors that may affect individual susceptibility to infection. This study looked at a polymorphism in the cathepsin D gene (refSNP ID: rs17571 previously examined in Alzheimer's disease (AD. Methods Blood samples taken from 110 vCJD patients were tested for the C-T base change, and genotype data were compared with published frequencies for a control population using multiple logistic regression. Results There was a significant excess of the cathepsin D polymorphism TT genotype in the vCJD cohort compared to controls. The TT genotype was found to have a 9.75 fold increase in risk of vCJD compared to the CT genotype and a 10.92 fold increase compared to the CC genotype. Conclusion This mutation event has been observed to alter the protease activity of the cathepsin D protein and has been linked to an increase in amyloid beta plaque formation in AD. vCJD neuropathology is characterised by the presence of amyloid plaques, formed from the prion protein, and therefore alterations in the amyloid processing activity of cathepsin D may affect the neuropathogenesis of this disease.

  2. Displacement of the occluding loop by the parasite protein, chagasin, results in efficient inhibition of human cathepsin B.

    Science.gov (United States)

    Redzynia, Izabela; Ljunggren, Anna; Abrahamson, Magnus; Mort, John S; Krupa, Joanne C; Jaskolski, Mariusz; Bujacz, Grzegorz

    2008-08-15

    Cathepsin B is a papain-like cysteine protease showing both endo- and exopeptidase activity, the latter due to a unique occluding loop that restricts access to the active site cleft. To clarify the mode by which natural protein inhibitors manage to overcome this obstacle, we have analyzed the structure and function of cathepsin B in complexes with the Trypanosoma cruzi inhibitor, chagasin. Kinetic analysis revealed that substitution of His-110e, which anchors the loop in occluding position, results in 3-fold increased chagasin affinity (Ki for H110A cathepsin B, 0.35 nm) due to an improved association rate (kon, 5 x 10(5) m(-1)s(-1)). The structure of chagasin in complex with cathepsin B was solved in two crystal forms (1.8 and 2.67 angstroms resolution), demonstrating that the occluding loop is displaced to allow chagasin binding with its three loops, L4, L2, and L6, spanning the entire active site cleft. The occluding loop is differently displaced in the two structures, indicating a large range of movement and adoption of conformations forced by the inhibitor. The area of contact is slightly larger than in chagasin complexes with the endopeptidase, cathepsin L. However, residues important for high affinity to both enzymes are mainly found in the outer loops L4 and L6 of chagasin. The chagasin-cathepsin B complex provides a structural framework for modeling and design of inhibitors for cruzipain, the parasite cysteine protease and a virulence factor in Chagas disease.

  3. 香蕉穿孔线虫组织蛋白酶B基因的克隆与分析%Cloning and analysis of cathepsin B gene of Radopholus similis

    Institute of Scientific and Technical Information of China (English)

    李丹蕾; 李宇; 谢辉; 徐春玲; 黄欣

    2013-01-01

    为了获得香蕉穿孔线虫的组织蛋白酶B基因,分析该基因的序列、结构及其功能,为进一步研究植物寄生线虫组织蛋白酶的功能及其在线虫防治中的应用提供科学依据.我们应用SMART技术构建了香蕉穿孔线虫cDNA文库;采用SL法,克隆得到香蕉穿孔线虫组织蛋白酶B基因全长cDNA,通过测序获得1 257 bp全长序列,命名为Rs-cb-1 (GenBank:GU360972),该基因cDNA全长序列包括1 071 bp的完整ORF,编码356个氨基酸,蛋白质相对分子质量为41 400.对该基因的序列结构及其编码的蛋白2级结构和三维结构与功能进行分析和预测结果表明,Rs-cb-1序列与其他寄生虫的组织蛋白酶B基因序列相比,该基因与秀丽小杆线虫组织蛋白酶B基因的亲缘关系最近;其编码蛋白主要为细胞外分泌蛋白,定位于微体(过氧化物酶体)、内质网膜和内质网管腔上,约有25个氨基酸跨膜区段位于蛋白质的C端,其表面电荷呈明显的极性分布;另外,通过同源建模获得该蛋白的三维结构预测图,这些结构与已报道的组织蛋白酶B生物学功能相符.本研究分离克隆得到的Rs-cb-1,是首个分离克隆得到的香蕉穿孔线虫组织蛋白酶B基因,从而为该线虫组织蛋白酶的进一步研究奠定了基础.%The banana burrowing nematode,Radopholus similis,is a migratory endoparasite plant nematode and severely harms many tropical and subtropical crops.It is the most important invasive species to banana worldwide,and is listed as a quarantine pest in many countries.Nematicide have been used as the main approach to control R.similis.However,due to the high toxicity,nematicide has led to many environmental problems.Now,gene targeting has become a new sustainable strategy to control plant nematode.Cathepsin B is a lysosomal cysteine protease,and it occurs in a wide range of parasitic and free-living nematodes.It has been demonstrated that cathepsin B plays a very important role in

  4. Crystal structure of cathepsin A, a novel target for the treatment of cardiovascular diseases

    Energy Technology Data Exchange (ETDEWEB)

    Schreuder, Herman A., E-mail: herman.schreuder@sanofi.com; Liesum, Alexander, E-mail: alexander.liesum@sanofi.com; Kroll, Katja, E-mail: katja.kroll@sanofi.com; Böhnisch, Britta, E-mail: britta.boehnisch@sanofi.com; Buning, Christian, E-mail: christian.buning@sanofi.com; Ruf, Sven, E-mail: sven.ruf@sanofi.com; Sadowski, Thorsten, E-mail: thorsten.sadowski@sanofi.com

    2014-03-07

    Graphical abstract: - Highlights: • The structures of active cathepsin A and the inactive precursor are very similar. • The only major difference is the absence of a 40 residue activation domain. • The termini of the active catalytic core are held together by a disulfide bond. • Compound 1 reacts with the catalytic Ser150, building a tetrahedral intermediate. • Compound 2 is cleaved by the enzyme and a fragment remained bound. - Abstract: The lysosomal serine carboxypeptidase cathepsin A is involved in the breakdown of peptide hormones like endothelin and bradykinin. Recent pharmacological studies with cathepsin A inhibitors in rodents showed a remarkable reduction in cardiac hypertrophy and atrial fibrillation, making cathepsin A a promising target for the treatment of heart failure. Here we describe the crystal structures of activated cathepsin A without inhibitor and with two compounds that mimic the tetrahedral intermediate and the reaction product, respectively. The structure of activated cathepsin A turned out to be very similar to the structure of the inactive precursor. The only difference was the removal of a 40 residue activation domain, partially due to proteolytic removal of the activation peptide, and partially by an order–disorder transition of the peptides flanking the removed activation peptide. The termini of the catalytic core are held together by the Cys253–Cys303 disulfide bond, just before and after the activation domain. One of the compounds we soaked in our crystals reacted covalently with the catalytic Ser150 and formed a tetrahedral intermediate. The other compound got cleaved by the enzyme and a fragment, resembling one of the natural reaction products, was found in the active site. These studies establish cathepsin A as a classical serine proteinase with a well-defined oxyanion hole. The carboxylate group of the cleavage product is bound by a hydrogen-bonding network involving one aspartate and two glutamate side chains

  5. Cyclosporin a, but not FK506, induces osmotic lysis of pancreas zymogen granules, intra-acinar enzyme release, and lysosome instability by activating K+ channel.

    Science.gov (United States)

    Lee, Wing-Kee; Braun, Matthias; Langelüddecke, Christian; Thévenod, Frank

    2012-05-01

    The immunosuppressant tacrolimus (FK506) has improved pancreas allograft survival compared with cyclosporin A (CsA), possibly because of reduced acute pancreatitis following ischemia-reperfusion injury. Ion permeabilities in zymogen granule (ZG) membranes, including a KCNQ1 K channel, promote hormone-stimulated enzyme secretion. We investigated whether a differential modulation of ZG and lysosomal ion permeabilities and enzyme secretion by CsA/FK506 contributes to pancreatitis. Rat ZGs and lysosomes were isolated by gradient centrifugation, ion permeabilities assayed by osmotic lysis, and single-channel currents recorded in a planar lipid bilayer. Amylase release was measured in permeabilized acini and lysosomal cathepsin B release detected by immunoblotting. CsA (1-10 μM), but not FK506, enhanced ZGs osmotic lysis by selectively increasing K permeability up to 5-fold. Zymogen granule membrane K channels showed ∼2-fold increased single-channel open probability with CsA only. Cyclosporin A selectively increased basal (∼2-fold), but not cholecystokinin-octapeptide (1 nM)-induced amylase secretion in K medium only. Cyclosporin A (5 μM), but not FK506, increased cathepsin B release from lysosomes. Cyclosporin A selectively opens the ZG K channel and induces cathepsin B release from lysosomes, which cause increased in situ lysis of ZGs and may aggravate or fuel acute allograft pancreatitis following hypoxia-reperfusion injury.

  6. Para-toluenesulfonamide induces tongue squamous cell carcinoma cell death through disturbing lysosomal stability.

    Science.gov (United States)

    Liu, Zhe; Liang, Chenyuan; Zhang, Zhuoyuan; Pan, Jian; Xia, Hui; Zhong, Nanshan; Li, Longjiang

    2015-11-01

    Para-toluenesulfonamide (PTS) has been implicated with anticancer effects against a variety of tumors. In the present study, we investigated the inhibitory effects of PTS on tongue squamous cell carcinoma (Tca-8113) and explored the lysosomal and mitochondrial changes after PTS treatment in vitro. High-performance liquid chromatography showed that PTS selectively accumulated in Tca-8113 cells with a relatively low concentration in normal fibroblasts. Next, the effects of PTS on cell viability, invasion, and cell death were determined. PTS significantly inhibited Tca-8113 cells' viability and invasive ability with increased cancer cell death. Flow cytometric analysis and the lactate dehydrogenase release assay showed that PTS induced cancer cell death by activating apoptosis and necrosis simultaneously. Morphological changes, such as cellular shrinkage, nuclear condensation as well as formation of apoptotic body and secondary lysosomes, were observed, indicating that PTS might induce cell death through disturbing lysosomal stability. Lysosomal integrity assay and western blot showed that PTS increased lysosomal membrane permeabilization associated with activation of lysosomal cathepsin B. Finally, PTS was shown to inhibit ATP biosynthesis and induce the release of mitochondrial cytochrome c. Therefore, our findings provide a novel insight into the use of PTS in cancer therapy.

  7. Regulatory elements within the prodomain of Falcipain-2, a cysteine protease of the malaria parasite Plasmodium falciparum.

    Directory of Open Access Journals (Sweden)

    Kailash C Pandey

    Full Text Available Falcipain-2, a papain family cysteine protease of the malaria parasite Plasmodium falciparum, plays a key role in parasite hydrolysis of hemoglobin and is a potential chemotherapeutic target. As with many proteases, falcipain-2 is synthesized as a zymogen, and the prodomain inhibits activity of the mature enzyme. To investigate the mechanism of regulation of falcipain-2 by its prodomain, we expressed constructs encoding different portions of the prodomain and tested their ability to inhibit recombinant mature falcipain-2. We identified a C-terminal segment (Leu(155-Asp(243 of the prodomain, including two motifs (ERFNIN and GNFD that are conserved in cathepsin L sub-family papain family proteases, as the mediator of prodomain inhibitory activity. Circular dichroism analysis showed that the prodomain including the C-terminal segment, but not constructs lacking this segment, was rich in secondary structure, suggesting that the segment plays a crucial role in protein folding. The falcipain-2 prodomain also efficiently inhibited other papain family proteases, including cathepsin K, cathepsin L, cathepsin B, and cruzain, but it did not inhibit cathepsin C or tested proteases of other classes. A structural model of pro-falcipain-2 was constructed by homology modeling based on crystallographic structures of mature falcipain-2, procathepsin K, procathepsin L, and procaricain, offering insights into the nature of the interaction between the prodomain and mature domain of falcipain-2 as well as into the broad specificity of inhibitory activity of the falcipain-2 prodomain.

  8. Structural Basis for Reversible and Irreversible Inhibition of Human Cathepsin L by their Respective dipeptidyl glyoxal and diazomethylketone Inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    R Shenoy; J Sivaraman

    2011-12-31

    Cathepsin L plays a key role in many pathophysiological conditions including rheumatoid arthritis, tumor invasion and metastasis, bone resorption and remodeling. Here we report the crystal structures of two analogous dipeptidyl inhibitor complexes which inhibit human cathepsin L in reversible and irreversible modes, respectively. To-date, there are no crystal structure reports of complexes of proteases with their glyoxal inhibitors or complexes of cathepsin L and their diazomethylketone inhibitors. These two inhibitors - inhibitor 1, an {alpha}-keto-{beta}-aldehyde and inhibitor 2, a diazomethylketone, have different groups in the S1 subsite. Inhibitor 1 [Z-Phe-Tyr (OBut)-COCHO], with a Ki of 0.6 nM, is the most potent, reversible, synthetic peptidyl inhibitor of cathepsin L reported to-date. The structure of the inhibitor 1 complex was refined up to 2.2 {angstrom} resolution. The structure of the complex of the inhibitor 2 [Z-Phe-Tyr (t-Bu)-diazomethylketone], an irreversible inhibitor that can inactivate cathepsin L at {micro}M concentrations, was refined up to 1.76 {angstrom} resolution. These two inhibitors have substrate-like interactions with the active site cysteine (Cys25). Inhibitor 1 forms a tetrahedral hemithioacetal adduct, whereas the inhibitor 2 forms a thioester with Cys25. The inhibitor 1 {beta}-aldehyde group is shown to make a hydrogen bond with catalytic His163, whereas the ketone carbonyl oxygen of the inhibitor 2 interacts with the oxyanion hole. tert-Butyl groups of both inhibitors are found to make several non-polar contacts with S' subsite residues of cathepsin L. These studies, combined with other complex structures of cathepsin L, reveal the structural basis for their potency and selectivity.

  9. The lysosome and neurodegenerative diseases

    Institute of Scientific and Technical Information of China (English)

    Lisha Zhang; Rui Sheng; Zhenghong Qin

    2009-01-01

    It has long been believed that the lysosome is an important digestive organelle. There is increasing evidence that the lysosome is also involved in pathogenesis of a variety of neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis. Abnormal protein degradation and deposition induced by lysosoreal dysfunction may be the primary contributor to age-related neurodegeneration. In this review, the possible relationship between lysosome and various neurodegenerative diseases is described.

  10. Supermarket Proteases.

    Science.gov (United States)

    Hagar, William G.; Bullerwell, Lornie D.

    2003-01-01

    Presents a laboratory activity on enzymes. Uses common items found in the supermarket that contain protease enzymes, such as contact lens cleaner and meat tenderizer. Demonstrates the digestion of gelatin proteins as part of enzymatic reactions. (Author/SOE)

  11. Citreoviridin Induces Autophagy-Dependent Apoptosis through Lysosomal-Mitochondrial Axis in Human Liver HepG2 Cells.

    Science.gov (United States)

    Wang, Yuexia; Liu, Yanan; Liu, Xiaofang; Jiang, Liping; Yang, Guang; Sun, Xiance; Geng, Chengyan; Li, Qiujuan; Yao, Xiaofeng; Chen, Min

    2015-08-06

    Citreoviridin (CIT) is a mycotoxin derived from fungal species in moldy cereals. In our previous study, we reported that CIT stimulated autophagosome formation in human liver HepG2 cells. Here, we aimed to explore the relationship of autophagy with lysosomal membrane permeabilization and apoptosis in CIT-treated cells. Our data showed that CIT increased the expression of LC3-II, an autophagosome biomarker, from the early stage of treatment (6 h). After treatment with CIT for 12 h, lysosomal membrane permeabilization occurred, followed by the release of cathepsin D in HepG2 cells. Inhibition of autophagosome formation with siRNA against Atg5 attenuated CIT-induced lysosomal membrane permeabilization. In addition, CIT induced collapse of mitochondrial transmembrane potential as assessed by JC-1 staining. Furthermore, caspase-3 activity assay showed that CIT induced apoptosis in HepG2 cells. Inhibition of autophagosome formation attenuated CIT-induced apoptosis, indicating that CIT-induced apoptosis was autophagy-dependent. Cathepsin D inhibitor, pepstatin A, relieved CIT-induced apoptosis as well, suggesting the involvement of the lysosomal-mitochondrial axis in CIT-induced apoptosis. Taken together, our data demonstrated that CIT induced autophagy-dependent apoptosis through the lysosomal-mitochondrial axis in HepG2 cells. The study thus provides essential mechanistic insight, and suggests clues for the effective management and treatment of CIT-related diseases.

  12. Role of Proteases in Chronic Obstructive Pulmonary Disease

    Directory of Open Access Journals (Sweden)

    Kailash C. Pandey

    2017-08-01

    Full Text Available Chronic obstructive pulmonary disease (COPD is generally associated with progressive destruction of airways and lung parenchyma. Various factors play an important role in the development and progression of COPD, like imbalance of proteases, environmental and genetic factors and oxidative stress. This review is specifically focused on the role of proteases and their imbalance in COPD. There are three classes (serine, mettalo, and cysteine of proteases involved in COPD. In serine proteases, neutrophil elastase, cathepsin G, and proteinase-3 are involved in destruction of alveolar tissue. Matrix-mettaloproteinase-9, 12, 13, plays an influential role in severity of COPD. Among cysteine proteases, caspase-3, caspases-8 and caspase-9 play an important role in controlling apoptosis. These proteases activities can be regulated by inhibitors like α-1-antitrypsin, neutrophil elastase inhibitor, and leukocyte protease inhibitor. Studies suggest that neutrophil elastase may be a therapeutic target for COPD, and specific inhibitor against this enzyme has potential role to control the disease. Current study suggests that Dipeptidyl Peptidase IV is a potential marker for COPD. Since the expression of proteases and its inhibitors play an important role in COPD pathogenesis, therefore, it is worth investigating the role of proteases and their regulation. Understanding the biochemical basis of COPD pathogenesis using advanced tools in protease biochemistry and aiming toward translational research from bench-to-bedside will have great impact to deal with this health problem.

  13. The role of autophagic and lysosomal pathways in ischemic brain injury******

    Institute of Scientific and Technical Information of China (English)

    Zhaohua Gu; Nan Shi; Qian Zhang; Wei Zhang; Meizhen Zhao; Xiaojiang Sun; Yinyi Sun; Kangyong Liu; Fen Wang; Ting Zhang; Qiang Li; Liwei Shen; Ling Zhou; Liang Dong

    2013-01-01

    Autophagy is involved in neural cel death after cerebral ischemia. Our previous studies showed that rapamycin-induced autophagy decreased the rate of apoptosis, but the rate of apoptosis was creased after the autophagy inhibitor, 3-methyladenine, was used. In this study, a suture-occluded method was performed to generate a rat model of brain ischemia. Under a transmission electron microscope, autophagic bodies and autophagy lysosomes were markedly accumulated in neurons at 4 hours post brain ischemic injury, with their numbers gradual y reducing over time. Western blotting demonstrated that protein levels of light chain 3-II and cathepsin B were significantly in-creased within 4 hours of ischemic injury, but these levels were not persistently upregulated over time. Confocal microscopy showed that autophagy was mainly found in neurons with positive light chain 3 signal. Injection of rapamycin via tail vein promoted the occurrence of autophagy in rat brain tissue after cerebral ischemia and elevated light chain 3 and cathepsin B expression. However, in-jection of 3-methyladenine significantly diminished light chain 3-II and cathepsin B expression. Results verified that autophagic and lysosomal activity is increased in ischemic neurons. Abnormal components in cel s can be eliminated through upregulating cel autophagy or inhibiting autophagy after ischemic brain injury, resulting in a dynamic balance of substances in cel s. Moreover, drugs that interfere with autophagy may be potential therapies for the treatment of brain injury.

  14. Human macrophage foam cells degrade atherosclerotic plaques through cathepsin K mediated processes

    Directory of Open Access Journals (Sweden)

    Larsen Lise

    2010-04-01

    Full Text Available Abstract Background Proteolytic degradation of Type I Collagen by proteases may play an important role in remodeling of atherosclerotic plaques, contributing to increased risk of plaque rupture. The aim of the current study was to investigate whether human macrophage foam cells degrade the extracellular matrix (ECM of atherosclerotic plaques by cathepsin K mediated processes. Methods We 1 cultured human macrophages on ECM and measured cathepsin K generated fragments of type I collagen (C-terminal fragments of Type I collagen (CTX-I 2 investigated the presence of CTX-I in human coronary arteries and 3 finally investigated the clinical potential by measuring circulating CTX-I in women with and without radiographic evidence of aortic calcified atherosclerosis. Results Immune-histochemistry of early and advanced lesions of coronary arteries demonstrated co-localization of Cathepsin-K and CTX-I in areas of intimal hyperplasia and in shoulder regions of advanced plaques. Treatment of human monocytes with M-CSF or M-CSF+LDL generated macrophages and foam cells producing CTX-I when cultured on type I collagen enriched matrix. Circulating levels of CTX-I were not significantly different in women with aortic calcifications compared to those without. Conclusions Human macrophage foam cells degrade the atherosclerotic plaques though cathepsin K mediated processes, resulting in increase in levels of CTX-I. Serum CTX-I was not elevated in women with aortic calcification, likely due to the contribution of CTX-I from osteoclastic bone resorption which involves Cathepsin-K. The human macrophage model system may be used to identify important pathway leading to excessive proteolytic plaque remodeling and plaque rupture.

  15. Poly IC triggers a cathepsin D- and IPS-1-dependent pathway to enhance cytokine production and mediate dendritic cell necroptosis.

    Science.gov (United States)

    Zou, Jian; Kawai, Taro; Tsuchida, Tetsuo; Kozaki, Tatsuya; Tanaka, Hiroki; Shin, Kyung-Sue; Kumar, Himanshu; Akira, Shizuo

    2013-04-18

    RIG-I-like receptors (RLRs) sense virus-derived RNA or polyinosinic-polycytidylic acid (poly IC) to exert antiviral immune responses. Here, we examine the mechanisms underlying the adjuvant effects of poly IC. Poly IC was taken up by dendritic cells (DCs), and it induced lysosomal destabilization, which, in turn, activated an RLR-dependent signaling pathway. Upon poly IC stimulation, cathepsin D was released into the cytoplasm from the lysosome to interact with IPS-1, an adaptor molecule for RLRs. This interaction facilitated cathepsin D cleavage of caspase 8 and the activation of the transcription factor NF-κB, resulting in enhanced cytokine production. Further recruitment of the kinase RIP-1 to this complex initiated the necroptosis of a small number of DCs. HMGB1 released by dying cells enhanced IFN-β production in concert with poly IC. Collectively, these findings suggest that cathepsin D-triggered, IPS-1-dependent necroptosis is a mechanism that propagates the adjuvant efficacy of poly IC.

  16. Role of receptor-mediated endocytosis, endosomal acidification and cathepsin D in cholera toxin cytotoxicity.

    Science.gov (United States)

    El Hage, Tatiana; Merlen, Clémence; Fabrega, Sylvie; Authier, François

    2007-05-01

    Using the in situ liver model system, we have recently shown that, after cholera toxin binding to hepatic cells, cholera toxin accumulates in a low-density endosomal compartment, and then undergoes endosomal proteolysis by the aspartic acid protease cathepsin-D [Merlen C, Fayol-Messaoudi D, Fabrega S, El Hage T, Servin A, Authier F (2005) FEBS J272, 4385-4397]. Here, we have used a subcellular fractionation approach to address the in vivo compartmentalization and cytotoxic action of cholera toxin in rat liver parenchyma. Following administration of a saturating dose of cholera toxin to rats, rapid endocytosis of both cholera toxin subunits was observed, coincident with massive internalization of both the 45 kDa and 47 kDa Gsalpha proteins. These events coincided with the endosomal recruitment of ADP-ribosylation factor proteins, especially ADP-ribosylation factor-6, with a time course identical to that of toxin and the A subunit of the stimulatory G protein (Gsalpha) translocation. After an initial lag phase of 30 min, these constituents were linked to NAD-dependent ADP-ribosylation of endogenous Gsalpha, with maximum accumulation observed at 30-60 min postinjection. Assessment of the subsequent postendosomal fate of internalized Gsalpha revealed sustained endolysosomal transfer of the two Gsalpha isoforms. Concomitantly, cholera toxin increased in vivo endosome acidification rates driven by the ATP-dependent H(+)-ATPase pump and in vitro vacuolar acidification in hepatoma HepG2 cells. The vacuolar H(+)-ATPase inhibitor bafilomycin and the cathepsin D inhibitor pepstatin A partially inhibited, both in vivo and in vitro, the cAMP response to cholera toxin. This cathepsin D-dependent action of cholera toxin under the control of endosomal acidity was confirmed using cellular systems in which modification of the expression levels of cathepsin D, either by transfection of the cathepsin D gene or small interfering RNA, was followed by parallel changes in the cytotoxic

  17. Proteomic analysis of pycnogenol effects in RAW 264.7 macrophage reveals induction of cathepsin D expression and enhancement of phagocytosis.

    Science.gov (United States)

    Wu, Ting-Feng; Hsu, Chiung-Yueh; Huang, Huei-Sheng; Chou, Siao-Ping; Wu, Hung

    2007-11-28

    Pycnogenol, polyphenolic compounds extracted from the pine bark, is beneficial for human health. To understand more of its effects, the present study is to explore the protein expression pattern induced by pycnogenol in RAW 264.7 cells. Global analysis using two-dimensional gel electrophoresis indicated that treatment with pycnogenol induces upregulation of four proteins, whose identities were revealed by mass spectrometry as cathepsin D, keratinocyte lipid-binding protein, proteasome subunit alpha type 1, and annexin IV. The pycnogenol effect displayed a time- and concentration-dependent manner. Unlike pycnogenol, N-acetyl cysteine and vitamin C had no effect on cathepsin D expression. Further studies showed that cathepsin D induction is correlated with an increase of lysosomal staining and enhancement of phagocytosis. These results reveal the novel effects of pycnogenol on protein expression and phagocytic functions and illustrate the advantage of proteomics-based strategy in unveiling the molecular basis of phytochemicals.

  18. Efficient inhibition of cathepsin B by a secreted type 1 cystatin of Fasciola gigantica.

    Science.gov (United States)

    Siricoon, Sinee; Grams, Suksiri Vichasri; Grams, Rudi

    2012-12-01

    Cysteine proteases are important antigens in the liver fluke genus Fasciola, essential for infection, protection and nutrition. While their biochemistry, biological roles and application as vaccines have been thoroughly studied there is a lack of data concerning their regulation. In the present study we have continued our investigation of cysteine protease inhibitors in Fasciola gigantica and demonstrate, in comparison with FgStefin-1 and human cystatin C, that a second type 1 cystatin of the parasite, FgStefin-2, has been evolutionary adapted to block cathepsin B. The protein, which unusually for a type 1 cystatin carries a signal peptide, is expressed from the metacercarial to adult stage and located in the epithelial cells of the intestinal tract in all stages and in the prostate gland cells in adults. Both cell types may contribute to the released FgStefin-2 observed in the ES product of the parasite. Distinct isoforms of cathepsin B are essential for host tissue penetration during the early infection process and FgStefin-2 may act as key regulator, required to protect the minute juvenile from autoproteolysis. Expression in the prostate gland in the adult stage suggests an additional regulative role of cysteine protease activity in the reproductive system.

  19. Cancer-associated lysosomal changes

    DEFF Research Database (Denmark)

    Kallunki, T; Olsen, O D; Jaattela, Marja

    2013-01-01

    Rapidly dividing and invasive cancer cells are strongly dependent on effective lysosomal function. Accordingly, transformation and cancer progression are characterized by dramatic changes in lysosomal volume, composition and cellular distribution. Depending on one's point of view, the cancer-asso......:10.1038/onc.2012.292....

  20. LYSOSOMAL DISRUPTION BY BACTERIAL TOXINS

    Science.gov (United States)

    Bernheimer, Alan W.; Schwartz, Lois L.

    1964-01-01

    Bernheimer, Alan W. (New York University School of Medicine, New York), and Lois L. Schwartz. Lysosomal disruption by bacterial toxins. J. Bacteriol. 87:1100–1104. 1964.—Seventeen bacterial toxins were examined for capacity (i) to disrupt rabbit leukocyte lysosomes as indicated by decrease in turbidity of lysosomal suspensions, and (ii) to alter rabbit liver lysosomes as measured by release of β-glucuronidase and acid phosphatase. Staphylococcal α-toxin, Clostridium perfringens α-toxin, and streptolysins O and S affected lysosomes in both systems. Staphylococcal β-toxin, leucocidin and enterotoxin, Shiga neurotoxin, Serratia endotoxin, diphtheria toxin, tetanus neurotoxin, C. botulinum type A toxin, and C. perfringens ε-toxin were not active in either system. Staphylococcal δ-toxin, C. histolyticum collagenase, crude C. perfringens β-toxin, and crude anthrax toxin caused lysosomal damage in only one of the test systems. There is a substantial correlation between the hemolytic property of a toxin and its capacity to disrupt lysosomes, lending support to the concept that erythrocytes and lysosomes are bounded by similar membranes. PMID:5874534

  1. Cloning and expression of mouse legumain, a lysosomal endopeptidase.

    Science.gov (United States)

    Chen, J M; Dando, P M; Stevens, R A; Fortunato, M; Barrett, A J

    1998-01-01

    Legumain, a recently discovered mammalian cysteine endopeptidase, was found in all mouse tissues examined, but was particularly abundant in kidney and placenta. The distribution in subcellular fractions of mouse and rat kidney showed a lysosomal localization, and activity was detectable only after the organelles were disrupted. Nevertheless, ratios of legumain activity to that of cathepsin B differed considerably between mouse tissues. cDNA encoding mouse legumain was cloned and sequenced, the deduced amino acid sequence proving to be 83% identical to that of the human protein [Chen, Dando, Rawlings, Brown, Young, Stevens, Hewitt, Watts and Barrett (1997) J. Biol. Chem. 272, 8090-8098]. Recombinant mouse legumain was expressed in human embryonic kidney 293 cells by use of a vector containing a cytomegalovirus promoter. The recombinant enzyme was partially purified and found to be an asparagine-specific endopeptidase closely similar to naturally occurring pig kidney legumain. PMID:9742219

  2. Combined effects of thermal stress and Cd on lysosomal biomarkers and transcription of genes encoding lysosomal enzymes and HSP70 in mussels, Mytilus galloprovincialis.

    Science.gov (United States)

    Izagirre, Urtzi; Errasti, Aitzpea; Bilbao, Eider; Múgica, María; Marigómez, Ionan

    2014-04-01

    In estuaries and coastal areas, intertidal organisms may be subject to thermal stress resulting from global warming, together with pollution. In the present study, the combined effects of thermal stress and exposure to Cd were investigated in the endo-lysosomal system of digestive cells in mussels, Mytilus galloprovincialis. Mussels were maintained for 24h at 18°C and 26°C seawater temperature in absence and presence of 50 μg Cd/L seawater. Cadmium accumulation in digestive gland tissue, lysosomal structural changes and membrane stability were determined. Semi-quantitative PCR was applied to reveal the changes elicited by the different experimental conditions in hexosaminidase (hex), β-glucuronidase (gusb), cathepsin L (ctsl) and heat shock protein 70 (hsp70) gene transcription levels. Thermal stress provoked lysosomal enlargement whilst Cd-exposure led to fusion of lysosomes. Both thermal stress and Cd-exposure caused lysosomal membrane destabilisation. hex, gusb and ctsl genes but not hsp70 gene were transcriptionally up-regulated as a result of thermal stress. In contrast, all the studied genes were transcriptionally down-regulated in response to Cd-exposure. Cd bioaccumulation was comparable at 18°C and 26°C seawater temperatures but interactions between thermal stress and Cd-exposure were remarkable both in lysosomal biomarkers and in gene transcription. hex, gusb and ctsl genes, reacted to elevated temperature in absence of Cd but not in Cd-exposed mussels. Therefore, thermal stress resulting from global warming might influence the use and interpretation of lysosomal biomarkers in marine pollution monitoring programmes and, vice versa, the presence of pollutants may condition the capacity of mussels to respond against thermal stress in a climate change scenario.

  3. Possible role of proteases in preconditioning of brain cells to pathological conditions.

    Science.gov (United States)

    Yakovlev, A A; Gulyaeva, N V

    2015-02-01

    Preconditioning (PC) is one of the most effective strategies to reduce the severity of cell damage, in particular of nervous tissue cells. Although PC mechanisms are studied insufficiently, it is clear that proteases are involved in them, but their role has yet been not studied in detail. In this work, some mechanisms of a potential recruiting of proteases in PC are considered. Our attention is mainly focused on the protease families of caspases and cathepsins and on protease receptors. We present evidence that just these proteins are involved in the PC of brain cells. A hypothesis is proposed that secreted cathepsin B is involved in the realization of PC through activation of PAR2 receptor.

  4. The role of lysosomal cysteine proteases in crustacean immune response

    OpenAIRE

    FL Garcia-Carreño; MA Navarrete del Toro; A Muhlia-Almazan

    2014-01-01

    Over the long course of evolution and under the selective pressure exerted by pathogens and parasites, animals have selectively fixed a number of defense mechanisms against the constant attack of intruders. The immune response represents a key component to optimize the biological fitness of individuals. Two decades ago, prevention and control of diseases in crustacean aquaculture systems were considered priorities in most shrimp-producing countries, but knowledge was scarce and various pathog...

  5. Protease inhibitor from Moringa oleifera with potential for use as therapeutic drug and as seafood preservative.

    Science.gov (United States)

    Bijina, B; Chellappan, Sreeja; Krishna, Jissa G; Basheer, Soorej M; Elyas, K K; Bahkali, Ali H; Chandrasekaran, M

    2011-07-01

    Protease inhibitors are well known to have several applications in medicine and biotechnology. Several plant sources are known to return potential protease inhibitors. In this study plants belonging to different families of Leguminosae, Malvaceae, Rutaceae, Graminae and Moringaceae were screened for the protease inhibitor. Among them Moringa oleifera, belonging to the family Moringaceae, recorded high level of protease inhibitor activity after ammonium sulfate fractionation. M. oleifera, which grows throughout most of the tropics and having several industrial and medicinal uses, was selected as a source of protease inhibitor since so far no reports were made on isolation of the protease inhibitor. Among the different parts of M. oleifera tested, the crude extract isolated from the mature leaves and seeds showed the highest level of inhibition against trypsin. Among the various extraction media evaluated, the crude extract prepared in phosphate buffer showed maximum recovery of the protease inhibitor. The protease inhibitor recorded high inhibitory activity toward the serine proteases thrombin, elastase, chymotrypsin and the cysteine proteases cathepsin B and papain which have more importance in pharmaceutical industry. The protease inhibitor also showed complete inhibition of activities of the commercially available proteases of Bacillus licheniformis and Aspergillus oryzae. However, inhibitory activities toward subtilisin, esperase, pronase E and proteinase K were negligible. Further, it was found that the protease inhibitor could prevent proteolysis in a commercially valuable shrimp Penaeus monodon during storage indicating the scope for its application as a seafood preservative. This is the first report on isolation of a protease inhibitor from M. oleifera.

  6. Late stage cathepsin C, CXCL13 and Ki-67 overexpression correlate with regional neuropathology in a BSE transgenic murine model.

    Science.gov (United States)

    Vidal, E; Tortosa, R; Marco, P; Fondevila, D; Rabanal, R M; Torres, J M; Pumarola, M

    2013-01-01

    A DNA microarray-based gene expression analysis study was performed with bovine spongiform encephalopathy (BSE) transgenic mice. Several genes were found to be overexpressed including the lysosomal enzyme cathepsin C, the chemokine CXCL13 and a number of genes related to cellular proliferation. The brains from terminal stage, BSE inoculated, 'bovinized', transgenic mice were subjected to immunohistochemistry with antibodies against these two proteins and Ki-67, a cell proliferation marker, to assess the biological relevance of the gene expression changes. Differential expression of cathepsin C and CXCL13 proteins and increased expression of Ki-67 was observed. These changes were localized to areas of deposition of PrP(res) and spongiform change and to areas showing an astroglial and microglial response. These findings suggest that these proteins are involved in the mechanisms leading to the establishment of transmissible spongiform encephalopathy.

  7. Giardia duodenalis Surface Cysteine Proteases Induce Cleavage of the Intestinal Epithelial Cytoskeletal Protein Villin via Myosin Light Chain Kinase.

    Directory of Open Access Journals (Sweden)

    Amol Bhargava

    Full Text Available Giardia duodenalis infections are among the most common causes of waterborne diarrhoeal disease worldwide. At the height of infection, G. duodenalis trophozoites induce multiple pathophysiological processes within intestinal epithelial cells that contribute to the development of diarrhoeal disease. To date, our understanding of pathophysiological processes in giardiasis remains incompletely understood. The present study reveals a previously unappreciated role for G. duodenalis cathepsin cysteine proteases in intestinal epithelial pathophysiological processes that occur during giardiasis. Experiments first established that Giardia trophozoites indeed produce cathepsin B and L in strain-dependent fashion. Co-incubation of G. duodenalis with human enterocytes enhanced cathepsin production by Assemblage A (NF and S2 isolates trophozoites, but not when epithelial cells were exposed to Assemblage B (GSM isolate trophozoites. Direct contact between G. duodenalis parasites and human intestinal epithelial monolayers resulted in the degradation and redistribution of the intestinal epithelial cytoskeletal protein villin; these effects were abolished when parasite cathepsin cysteine proteases were inhibited. Interestingly, inhibition of parasite proteases did not prevent degradation of the intestinal tight junction-associated protein zonula occludens 1 (ZO-1, suggesting that G. duodenalis induces multiple pathophysiological processes within intestinal epithelial cells. Finally, this study demonstrates that G. duodenalis-mediated disruption of villin is, at least, in part dependent on activation of myosin light chain kinase (MLCK. Taken together, this study indicates a novel role for parasite cathepsin cysteine proteases in the pathophysiology of G. duodenalis infections.

  8. Potent inhibition of feline coronaviruses with peptidyl compounds targeting coronavirus 3C-like protease.

    Science.gov (United States)

    Kim, Yunjeong; Mandadapu, Sivakoteswara Rao; Groutas, William C; Chang, Kyeong-Ok

    2013-02-01

    Feline coronavirus infection is common among domestic and exotic felid species and usually associated with mild or asymptomatic enteritis; however, feline infectious peritonitis (FIP) is a fatal disease of cats that is caused by systemic infection with a feline infectious peritonitis virus (FIPV), a variant of feline enteric coronavirus (FECV). Currently, there is no specific treatment approved for FIP despite the importance of FIP as the leading infectious cause of death in young cats. During the replication process, coronavirus produces viral polyproteins that are processed into mature proteins by viral proteases, the main protease (3C-like [3CL] protease) and the papain-like protease. Since the cleavages of viral polyproteins are an essential step for virus replication, blockage of viral protease is an attractive target for therapeutic intervention. Previously, we reported the generation of broad-spectrum peptidyl inhibitors against viruses that possess a 3C or 3CL protease. In this study, we further evaluated the antiviral effects of the peptidyl inhibitors against feline coronaviruses, and investigated the interaction between our protease inhibitor and a cathepsin B inhibitor, an entry blocker, against a feline coronavirus in cell culture. Herein we report that our compounds behave as reversible, competitive inhibitors of 3CL protease, potently inhibited the replication of feline coronaviruses (EC(50) in a nanomolar range) and, furthermore, combination of cathepsin B and 3CL protease inhibitors led to a strong synergistic interaction against feline coronaviruses in a cell culture system.

  9. Tuning and predicting biological affinity: aryl nitriles as cysteine protease inhibitors.

    Science.gov (United States)

    Ehmke, Veronika; Quinsaat, Jose Enrico Q; Rivera-Fuentes, Pablo; Heindl, Cornelia; Freymond, Céline; Rottmann, Matthias; Brun, Reto; Schirmeister, Tanja; Diederich, François

    2012-08-14

    A series of aryl nitrile-based ligands were prepared to investigate the effect of their electrophilicity on the affinity against the cysteine proteases rhodesain and human cathepsin L. Density functional theory calculations provided relative reactivities of the nitriles, enabling prediction of their biological affinity and cytotoxicity and a clear structure-activity relationship.

  10. In Vivo Evidence for Lysosome Depletion and Impaired Autophagic Clearance in Hereditary Spastic Paraplegia Type SPG11.

    Science.gov (United States)

    Varga, Rita-Eva; Khundadze, Mukhran; Damme, Markus; Nietzsche, Sandor; Hoffmann, Birgit; Stauber, Tobias; Koch, Nicole; Hennings, J Christopher; Franzka, Patricia; Huebner, Antje K; Kessels, Michael M; Biskup, Christoph; Jentsch, Thomas J; Qualmann, Britta; Braulke, Thomas; Kurth, Ingo; Beetz, Christian; Hübner, Christian A

    2015-08-01

    Hereditary spastic paraplegia (HSP) is characterized by a dying back degeneration of corticospinal axons which leads to progressive weakness and spasticity of the legs. SPG11 is the most common autosomal-recessive form of HSPs and is caused by mutations in SPG11. A recent in vitro study suggested that Spatacsin, the respective gene product, is needed for the recycling of lysosomes from autolysosomes, a process known as autophagic lysosome reformation. The relevance of this observation for hereditary spastic paraplegia, however, has remained unclear. Here, we report that disruption of Spatacsin in mice indeed causes hereditary spastic paraplegia-like phenotypes with loss of cortical neurons and Purkinje cells. Degenerating neurons accumulate autofluorescent material, which stains for the lysosomal protein Lamp1 and for p62, a marker of substrate destined to be degraded by autophagy, and hence appears to be related to autolysosomes. Supporting a more generalized defect of autophagy, levels of lipidated LC3 are increased in Spatacsin knockout mouse embryonic fibrobasts (MEFs). Though distinct parameters of lysosomal function like processing of cathepsin D and lysosomal pH are preserved, lysosome numbers are reduced in knockout MEFs and the recovery of lysosomes during sustained starvation impaired consistent with a defect of autophagic lysosome reformation. Because lysosomes are reduced in cortical neurons and Purkinje cells in vivo, we propose that the decreased number of lysosomes available for fusion with autophagosomes impairs autolysosomal clearance, results in the accumulation of undegraded material and finally causes death of particularly sensitive neurons like cortical motoneurons and Purkinje cells in knockout mice.

  11. In Vivo Evidence for Lysosome Depletion and Impaired Autophagic Clearance in Hereditary Spastic Paraplegia Type SPG11.

    Directory of Open Access Journals (Sweden)

    Rita-Eva Varga

    2015-08-01

    Full Text Available Hereditary spastic paraplegia (HSP is characterized by a dying back degeneration of corticospinal axons which leads to progressive weakness and spasticity of the legs. SPG11 is the most common autosomal-recessive form of HSPs and is caused by mutations in SPG11. A recent in vitro study suggested that Spatacsin, the respective gene product, is needed for the recycling of lysosomes from autolysosomes, a process known as autophagic lysosome reformation. The relevance of this observation for hereditary spastic paraplegia, however, has remained unclear. Here, we report that disruption of Spatacsin in mice indeed causes hereditary spastic paraplegia-like phenotypes with loss of cortical neurons and Purkinje cells. Degenerating neurons accumulate autofluorescent material, which stains for the lysosomal protein Lamp1 and for p62, a marker of substrate destined to be degraded by autophagy, and hence appears to be related to autolysosomes. Supporting a more generalized defect of autophagy, levels of lipidated LC3 are increased in Spatacsin knockout mouse embryonic fibrobasts (MEFs. Though distinct parameters of lysosomal function like processing of cathepsin D and lysosomal pH are preserved, lysosome numbers are reduced in knockout MEFs and the recovery of lysosomes during sustained starvation impaired consistent with a defect of autophagic lysosome reformation. Because lysosomes are reduced in cortical neurons and Purkinje cells in vivo, we propose that the decreased number of lysosomes available for fusion with autophagosomes impairs autolysosomal clearance, results in the accumulation of undegraded material and finally causes death of particularly sensitive neurons like cortical motoneurons and Purkinje cells in knockout mice.

  12. In Vivo Evidence for Lysosome Depletion and Impaired Autophagic Clearance in Hereditary Spastic Paraplegia Type SPG11.

    Directory of Open Access Journals (Sweden)

    Rita-Eva Varga

    2015-08-01

    Full Text Available Hereditary spastic paraplegia (HSP is characterized by a dying back degeneration of corticospinal axons which leads to progressive weakness and spasticity of the legs. SPG11 is the most common autosomal-recessive form of HSPs and is caused by mutations in SPG11. A recent in vitro study suggested that Spatacsin, the respective gene product, is needed for the recycling of lysosomes from autolysosomes, a process known as autophagic lysosome reformation. The relevance of this observation for hereditary spastic paraplegia, however, has remained unclear. Here, we report that disruption of Spatacsin in mice indeed causes hereditary spastic paraplegia-like phenotypes with loss of cortical neurons and Purkinje cells. Degenerating neurons accumulate autofluorescent material, which stains for the lysosomal protein Lamp1 and for p62, a marker of substrate destined to be degraded by autophagy, and hence appears to be related to autolysosomes. Supporting a more generalized defect of autophagy, levels of lipidated LC3 are increased in Spatacsin knockout mouse embryonic fibrobasts (MEFs. Though distinct parameters of lysosomal function like processing of cathepsin D and lysosomal pH are preserved, lysosome numbers are reduced in knockout MEFs and the recovery of lysosomes during sustained starvation impaired consistent with a defect of autophagic lysosome reformation. Because lysosomes are reduced in cortical neurons and Purkinje cells in vivo, we propose that the decreased number of lysosomes available for fusion with autophagosomes impairs autolysosomal clearance, results in the accumulation of undegraded material and finally causes death of particularly sensitive neurons like cortical motoneurons and Purkinje cells in knockout mice.

  13. In Vivo Evidence for Lysosome Depletion and Impaired Autophagic Clearance in Hereditary Spastic Paraplegia Type SPG11

    Science.gov (United States)

    Varga, Rita-Eva; Khundadze, Mukhran; Damme, Markus; Nietzsche, Sandor; Hoffmann, Birgit; Stauber, Tobias; Koch, Nicole; Hennings, J. Christopher; Franzka, Patricia; Huebner, Antje K.; Kessels, Michael M.; Biskup, Christoph; Jentsch, Thomas J.; Qualmann, Britta; Braulke, Thomas; Kurth, Ingo; Beetz, Christian; Hübner, Christian A.

    2015-01-01

    Hereditary spastic paraplegia (HSP) is characterized by a dying back degeneration of corticospinal axons which leads to progressive weakness and spasticity of the legs. SPG11 is the most common autosomal-recessive form of HSPs and is caused by mutations in SPG11. A recent in vitro study suggested that Spatacsin, the respective gene product, is needed for the recycling of lysosomes from autolysosomes, a process known as autophagic lysosome reformation. The relevance of this observation for hereditary spastic paraplegia, however, has remained unclear. Here, we report that disruption of Spatacsin in mice indeed causes hereditary spastic paraplegia-like phenotypes with loss of cortical neurons and Purkinje cells. Degenerating neurons accumulate autofluorescent material, which stains for the lysosomal protein Lamp1 and for p62, a marker of substrate destined to be degraded by autophagy, and hence appears to be related to autolysosomes. Supporting a more generalized defect of autophagy, levels of lipidated LC3 are increased in Spatacsin knockout mouse embryonic fibrobasts (MEFs). Though distinct parameters of lysosomal function like processing of cathepsin D and lysosomal pH are preserved, lysosome numbers are reduced in knockout MEFs and the recovery of lysosomes during sustained starvation impaired consistent with a defect of autophagic lysosome reformation. Because lysosomes are reduced in cortical neurons and Purkinje cells in vivo, we propose that the decreased number of lysosomes available for fusion with autophagosomes impairs autolysosomal clearance, results in the accumulation of undegraded material and finally causes death of particularly sensitive neurons like cortical motoneurons and Purkinje cells in knockout mice. PMID:26284655

  14. Megalin/Cubulin-Lysosome-mediated Albumin Reabsorption Is Involved in the Tubular Cell Activation of NLRP3 Inflammasome and Tubulointerstitial Inflammation.

    Science.gov (United States)

    Liu, Dan; Wen, Yi; Tang, Tao-Tao; Lv, Lin-Li; Tang, Ri-Ning; Liu, Hong; Ma, Kun-Ling; Crowley, Steve D; Liu, Bi-Cheng

    2015-07-17

    Albuminuria contributes to the development and progression of chronic kidney disease by inducing tubulointerstitial inflammation (TI) and fibrosis. However, the exact mechanisms of TI in response to albuminuria are unresolved. We previously demonstrated that NLRP3 and inflammasomes mediate albumin-induced lesions in tubular cells. Here, we further investigated the role of endocytic receptors and lysosome rupture in NLRP3 inflammasome activation. A murine proteinuric nephropathy model was induced by albumin overload as described previously. The priming and activation signals for inflammasome complex formation were evoked simultaneously by albumin excess in tubular epithelial cells. The former signal was dependent on a albumin-triggered NF-κB pathway activation. This process is mediated by the endocytic receptor, megalin and cubilin. However, the silencing of megalin or cubilin inhibited the albumin-induced NLRP3 signal. Notably, subsequent lysosome rupture and the corresponding release of lysosomal hydrolases, especially cathepsin B, were observed in tubular epithelial cells exposed to albumin. Cathepsin B release and distribution are essential for NLRP3 signal activation, and inhibitors of cathepsin B suppressed the NLRP3 signal in tubular epithelial cells. Taken together, our findings suggest that megalin/cubilin and lysosome rupture are involved in albumin-triggered tubular injury and TI. This study provides novel insights into albuminuria-induced TI and implicates the active control of albuminuria as a critical strategy to halt the progression of chronic kidney disease.

  15. Cancer-associated lysosomal changes

    DEFF Research Database (Denmark)

    Kallunki, T; Olsen, O D; Jaattela, Marja

    2013-01-01

    Rapidly dividing and invasive cancer cells are strongly dependent on effective lysosomal function. Accordingly, transformation and cancer progression are characterized by dramatic changes in lysosomal volume, composition and cellular distribution. Depending on one's point of view, the cancer-associated......-targeting anti-cancer drugs. In this review we compile our current knowledge on cancer-associated changes in lysosomal composition and discuss the consequences of these alterations to cancer progression and the possibilities they can bring to cancer therapy.Oncogene advance online publication, 9 July 2012; doi...

  16. The proinflammatory cytokines interleukin-1α and tumor necrosis factor α promote the expression and secretion of proteolytically active cathepsin S from human chondrocytes.

    Science.gov (United States)

    Caglič, Dejan; Repnik, Urška; Jedeszko, Christopher; Kosec, Gregor; Miniejew, Catherine; Kindermann, Maik; Vasiljeva, Olga; Turk, Vito; Wendt, K Ulrich; Sloane, Bonnie F; Goldring, Mary B; Turk, Boris

    2013-02-01

    Osteoarthritis and rheumatoid arthritis are destructive joint diseases that involve the loss of articular cartilage. Degradation of cartilage extracellular matrix is believed to occur due to imbalance between the catabolic and anabolic processes of resident chondrocytes. Previous work has suggested that various lysosomal cysteine cathepsins participate in cartilage degeneration; however, their exact roles in disease development and progression have not been elucidated. In order to study degradation processes under conditions resembling the in vivo milieu of the cartilage, we cultivated chondrocytes on a type II collagen-containing matrix. Stimulation of the cultivated chondrocytes with interleukin-1α and/or tumor necrosis factor α resulted in a time-dependent increase in cathepsin S expression and induced its secretion into the conditioned media. Using a novel bioluminescent activity-based probe, we were able to demonstrate a significant increase in proteolytic activity of cathepsin S in the conditioned media of proinflammatory cytokine-stimulated chondrocytes. For the first time, cathepsin S was demonstrated to be secreted from chondrocytes upon stimulation with the proinflammatory cytokines, and displayed proteolytic activity in culture supernatants. Its stability at neutral pH and potent proteolytic activity on extracellular matrix components mean that cathepsin S may contribute significantly to cartilage degradation and may thus be considered a potential drug target in joint diseases.

  17. Identification of Plakortide E from the Caribbean Sponge Plakortis halichondroides as a Trypanocidal Protease Inhibitor using Bioactivity-Guided Fractionation

    Directory of Open Access Journals (Sweden)

    Swarna Oli

    2014-05-01

    Full Text Available In this paper, we report new protease inhibitory activity of plakortide E towards cathepsins and cathepsin-like parasitic proteases. We further report on its anti-parasitic activity against Trypanosoma brucei with an IC50 value of 5 μM and without cytotoxic effects against J774.1 macrophages at 100 μM concentration. Plakortide E was isolated from the sponge Plakortis halichondroides using enzyme assay-guided fractionation and identified by NMR spectroscopy and mass spectrometry. Furthermore, enzyme kinetic studies confirmed plakortide E as a non-competitive, slowly-binding, reversible inhibitor of rhodesain.

  18. Expression characteristics and specific antibody reactivity of diverse cathepsin F members of Paragonimus westermani.

    Science.gov (United States)

    Ahn, Chun-Seob; Na, Byoung-Kuk; Chung, Dong-Ll; Kim, Jeong-Geun; Kim, Jin-Taek; Kong, Yoon

    2015-02-01

    Paragonimiasis, caused by the lung fluke Paragonimus, is a major food-borne helminthic disease. Differential diagnosis of paragonimiasis from tuberculosis and other infectious granulomas in the lung is a prerequisite to proper management of patients. Cysteine proteases of Paragonimus westermani (PwCPs) invoke specific antibody responses against patient sera, while antibody capturing activity of different PwCPs has not been comparatively analyzed. In this study, we observed the expressional regulation of 11 species of different PwCPs (PwCP1-11). We expressed recombinant PwCPs and assessed diagnostic reliability employing sera from patients with P. westermani (n=138), other trematodiases (n=80), cestodiases (n=60) and pulmonary tuberculosis (n=20), and those of normal controls (n=20). PwCPs formed a monophyletic clade into cathepsin F and showed differential expression patterns along with developmental stages of worm. Bacterially expressed recombinant PwCPs (rPwCPs) exhibited variable sensitivity of 38.4-84.5% and specificity of 87.2-100% in diagnosing homologous infection. rPwCPs recognized specific antibodies of experimental cat sera as early as 3 or 6weeks after infection. Patient sera of fascioliasis, Schistosomiasis japonicum and clonorchiasis demonstrated weak cross-reactions. Our results demonstrate that diverse PwCPs of the cathepsin F family participate in inducing specific antibody responses. Most P. westermani cathepsin F, except for PwCP2 (AAF21461), which showed negligible antibody responses, might be applicable for paragonimiasis serodiagnosis.

  19. Activity of cathepsins in rat's spleen due to experimentally induced pancreatitis.

    Science.gov (United States)

    Maciejewski, R; Burdan, F; Madej, B; Kiś, G; Szkodziak, P; Burski, K

    The aim of this study was to establish and quantify the changes of the level of cathepsin B, D and L in the spleen during experimental pancreatitis. The experiment was carried out in 115 male Wistar rats, randomly divided into three groups: intact (n = 15), injected with 0.9% NaCl solution into the common bile pancreatic duct (n = 50) and injected with 5% sodium taurocholate into this duct to induce acute pancreatitis (n = 50). After 2, 6, 12, 24 and 48 hours rats were anaesthetised, and blood was taken for amylase determination from the heart, and the spleen was removed. Alpha-amylase level in the blood serum samples was measured by enzymatic method. Cathepsin activity was established by spectrophotometric methods using substrates which form coloured complexes when they react with these proteases. The specific free fraction activity of cathepsin B, D and L in the spleen changed during the course of experiment, but there was no correlation between their activity and the intensity of pancreatitis established by serum amylase level.

  20. uPARAP/endo180 directs lysosomal delivery and degradation of collagen IV

    DEFF Research Database (Denmark)

    Kjøller, Lars; Engelholm, Lars H; Høyer-Hansen, Maria

    2004-01-01

    transmembrane glycoprotein urokinase plasminogen activator receptor-associated protein (uPARAP/endo180) directs collagen IV for lysosomal delivery and degradation. In wild-type fibroblasts, fluorescently labeled collagen IV was first internalized into vesicular structures with diffuse fluorescence eventually...... appearing uniformly within the wild-type cells after longer incubation times. In these cells, some collagen-containing vesicles were identified as lysosomes by staining for LAMP-1. In contrast, collagen IV remained extracellular and associated with fiber-like structures on uPARAP/endo180-deficient...... fibroblasts. Blocking lysosomal cysteine proteases with the inhibitor E64d resulted in strong accumulation of collagen IV in lysosomes in wild-type cells, but only very weak intracellular fluorescence accumulation in uPARAP/endo180-deficient fibroblasts. We conclude that uPARAP/endo180 is critical...

  1. Characterization and differential expression of cathepsin L3 alleles from Fasciola hepatica.

    Science.gov (United States)

    Zawistowska-Deniziak, A; Wasyl, K; Norbury, L J; Wesołowska, A; Bień, J; Grodzik, M; Wiśniewski, M; Bąska, P; Wędrychowicz, H

    2013-07-01

    Fasciola hepatica infections cause significant global problems in veterinary and human medicine, including causing huge losses in cattle and sheep production. F. hepatica host infection is a multistage process and flukes express papain-like cysteine proteases, termed cathepsins, which play pivotal roles in virulence through host entry, tissue migration and immune evasion. Expression of these proteases is developmentally regulated. Recent studies indicate that excystment of infective larvae is dependent on cysteine proteases and together FhCL3 and FhCB account for over 80% of total protease activity detectable in newly excysted juvenile (NEJ) fluke. This paper focuses on members of the cathepsin L gene family, specifically those belonging to the CL3 clade. The cDNA of two novel cathepsin L3 proteases--FhCL3-1 and FhCL3-2 were cloned. The mRNA transcript expression levels for these enzymes were significantly different at various time points in life development stages obtained in vitro, from dormant metacercariae to NEJ 24h after excystment. Maximum expression levels were observed in NEJ immediately after excystment. In all stages examined by Real Time PCR, FhCL3-2 was expressed at a higher level compared to FhCL3-1 which was expressed only at very low levels. Western blot and immunohistochemical analysis also indicated higher expression of the FhCL3-2 allele and its secretory nature. The ability of antibody responses from rats and sheep challenged with F. hepatica to recognize recombinant FhCL3-1 and FhCL3-2 was shown to differ. Differences were also confirmed through the use of anti-rFhCL3-1 and anti-rFhCL3-2 sera in Western blot analysis of juvenile excretory/secretory (ES) material separated by 2D electrophoresis. These results indicate analysis of relative expression of parasite virulence factors from different populations is required, as this will likely impact the effectiveness of vaccines based on these antigens.

  2. Bupivacaine can enhance lysosomal activity in mouse muscle myoblasts%布比卡因增强小鼠成肌细胞溶酶体的活性

    Institute of Scientific and Technical Information of China (English)

    熊静薇; 毛雨; 李荣荣; 丁正年

    2015-01-01

    Objective To investigate the effects of bupivacaine on lysosomal abundance and activity in mouse muscle myoblasts.Methods Mouse myoblasts C2C12 was randomly divided into control group (without any treatment) and bupivacaine group (treated with bupivacaine 600 μ mol/L for 6 h).After then,the changes of lysosomal pH was assessed by LysoSensor pH indicator.The content of lysosomes was detected by LysoTracker probe.The expression of lysosomal-associated membrane protein-1 (LAMP-1) and Cathepsin B was detected by Western blot analysis.The activity of lysosomal proteolytic enzymes Cathepsin B was determined by MagicRed assay kit.Results Bupivacaine did not affect lysosomal pH.However,compared with the controls,lysosomal abundance was significantly increased 15.15% following bupivacaine treatment(P<0.01).Moreover,protein expression levels of LAMP-1 and Cathepsin B were significantly upregulated 36.41% and 35.29% respetctively by bupivacaine (P<0.01).Furthermore,the activity of Cathepsin B was significantly increased 23.74% by bupivacaine(P<0.01).Conclusions Bupivacaine increased lysosomal content and enhance lysosomal activity in mouse muscle myoblasts.%目的 探讨局部麻醉药布比卡因对小鼠成肌细胞溶酶体的影响. 方法 将体外培养的小鼠成肌细胞C2C12分为2组.对照组:不加任何药物;布比卡因组:以600μmol/L布比卡因刺激细胞6h.实验结束后,用LysoSensor探针评价溶酶体腔pH,用LysoTrackor探针检测溶酶体含量,用蛋白免疫印迹法检测溶酶体相关膜蛋白-1(LAMP-1)和溶酶体蛋白水解酶Cathepsin B的表达水平,并以MagicRed染色法测定Cathepsin B的活性.结果 布比卡因对溶酶体腔pH没有影响.但是,与对照组相比,布比卡因组溶酶体含量增加15.15% (P<0.01),LAMP-1与Cathepsin B表达量分别增加36.41%、35.29% (P<0.01),Cathepsin B活性增加23.74%(P<0.01).结论 布比卡因能增加小鼠成肌细胞溶酶体含量,增强溶酶体活性.

  3. Endosomes and lysosomes are involved in early steps of Tl(III)-mediated apoptosis in rat pheochromocytoma (PC12) cells.

    Science.gov (United States)

    Hanzel, Cecilia E; Almeira Gubiani, María F; Verstraeten, Sandra V

    2012-11-01

    The mechanisms that mediate thallium (Tl) toxicity are still not completely understood. The exposure of rat pheochromocytoma (PC12) cells to Tl(I) or Tl(III) activates both mitochondrial (Tl(I) and Tl(III)) and extrinsic (Tl(III)) pathways of apoptosis. In this work we evaluated the hypothesis that the effects of Tl(III) may be mediated by the damage to lysosomes, where it might be incorporated following the route of iron uptake. PC12 cells exposed for 3 h to 100 μM Tl(III) presented marked endosomal acidification, effect that was absent when cells were incubated in a serum-free medium and that was fully recovered when the latter was supplemented with transferrin. After 6 h of incubation the colocalization of cathepsins D and B with the lysosomal marker Lamp-1 was decreased together with an increase in the total activity of the enzymes. A permanent damage to lysosomes after 18 h of exposure was evidenced from the impairment of acridine orange uptake. Cathepsin D caused the cleavage of pro-apoptotic protein BID that is involved in the activation of the intrinsic pathway of apoptosis. Supporting that, BID cleavage and the activation of caspase 3 by Tl(III) were fully prevented when cells were preincubated with cathepsin D inhibitor (pepstatin A) and only partially prevented when cathepsin B inhibitor (E64d) was used. None of these inhibitors affected BID cleavage or caspase 3 activation in Tl(I)-treated cells. Together, experimental results support the role of Tl(III) uptake by the acidic cell compartments and their involvement in the early steps of Tl(III)-mediated PC12 cells apoptosis.

  4. Structural Dynamics Investigation of Human Family 1 & 2 Cystatin-Cathepsin L1 Interaction: A Comparison of Binding Modes.

    Science.gov (United States)

    Nandy, Suman Kumar; Seal, Alpana

    2016-01-01

    Cystatin superfamily is a large group of evolutionarily related proteins involved in numerous physiological activities through their inhibitory activity towards cysteine proteases. Despite sharing the same cystatin fold, and inhibiting cysteine proteases through the same tripartite edge involving highly conserved N-terminal region, L1 and L2 loop; cystatins differ widely in their inhibitory affinity towards C1 family of cysteine proteases and molecular details of these interactions are still elusive. In this study, inhibitory interactions of human family 1 & 2 cystatins with cathepsin L1 are predicted and their stability and viability are verified through protein docking & comparative molecular dynamics. An overall stabilization effect is observed in all cystatins on complex formation. Complexes are mostly dominated by van der Waals interaction but the relative participation of the conserved regions varied extensively. While van der Waals contacts prevail in L1 and L2 loop, N-terminal segment chiefly acts as electrostatic interaction site. In fact the comparative dynamics study points towards the instrumental role of L1 loop in directing the total interaction profile of the complex either towards electrostatic or van der Waals contacts. The key amino acid residues surfaced via interaction energy, hydrogen bonding and solvent accessible surface area analysis for each cystatin-cathepsin L1 complex influence the mode of binding and thus control the diverse inhibitory affinity of cystatins towards cysteine proteases.

  5. Structural Dynamics Investigation of Human Family 1 & 2 Cystatin-Cathepsin L1 Interaction: A Comparison of Binding Modes

    Science.gov (United States)

    Nandy, Suman Kumar; Seal, Alpana

    2016-01-01

    Cystatin superfamily is a large group of evolutionarily related proteins involved in numerous physiological activities through their inhibitory activity towards cysteine proteases. Despite sharing the same cystatin fold, and inhibiting cysteine proteases through the same tripartite edge involving highly conserved N-terminal region, L1 and L2 loop; cystatins differ widely in their inhibitory affinity towards C1 family of cysteine proteases and molecular details of these interactions are still elusive. In this study, inhibitory interactions of human family 1 & 2 cystatins with cathepsin L1 are predicted and their stability and viability are verified through protein docking & comparative molecular dynamics. An overall stabilization effect is observed in all cystatins on complex formation. Complexes are mostly dominated by van der Waals interaction but the relative participation of the conserved regions varied extensively. While van der Waals contacts prevail in L1 and L2 loop, N-terminal segment chiefly acts as electrostatic interaction site. In fact the comparative dynamics study points towards the instrumental role of L1 loop in directing the total interaction profile of the complex either towards electrostatic or van der Waals contacts. The key amino acid residues surfaced via interaction energy, hydrogen bonding and solvent accessible surface area analysis for each cystatin-cathepsin L1 complex influence the mode of binding and thus control the diverse inhibitory affinity of cystatins towards cysteine proteases. PMID:27764212

  6. Do alterations in follicular fluid proteases contribute to human infertility?

    Science.gov (United States)

    Cookingham, Lisa Marii; Van Voorhis, Bradley J; Ascoli, Mario

    2015-05-01

    Cathepsin L and ADAMTS-1 are known to play critical roles in follicular rupture, ovulation, and fertility in mice. Similar studies in humans are limited; however, both are known to increase during the periovulatory period. No studies have examined either protease in the follicular fluid of women with unexplained infertility or infertility related to advanced maternal age (AMA). We sought to determine if alterations in cathepsin L and/or ADAMTS-1 existed in these infertile populations. Patients undergoing in vitro fertilization (IVF) for unexplained infertility or AMA-related infertility were prospectively recruited for the study; patients with tubal or male factor infertility were recruited as controls. Follicular fluid was collected to determine gene expression (via quantitative polymerase chain reaction), enzyme concentrations (via enzyme-linked immunosorbent assays), and enzymatic activities (via fluorogenic enzyme cleavage assay or Western blot analysis) of cathepsin L and ADAMTS-1. The analysis included a total of 42 patients (14 per group). We found no statistically significant difference in gene expression, enzyme concentration, or enzymatic activity of cathepsin L or ADAMTS-1 in unexplained infertility or AMA-related infertility as compared to controls. We also found no statistically significant difference in expression or concentration with advancing age. Cathepsin L and ADAMTS-1 are not altered in women with unexplained infertility or AMA-related infertility undergoing IVF, and they do not decline with advancing age. It is possible that differences exist in natural cycles, contributing to infertility; however, our findings do not support a role for protease alterations as a common cause of infertility.

  7. New method to discriminate between cathepsin B and cathepsin L in crude extracts from fish muscle based on a simple acidification procedure

    DEFF Research Database (Denmark)

    Godiksen, Helene; Nielsen, Henrik Hauch

    2007-01-01

    A new and simple method to distinguish between cathepsin B and cathepsin L in crude extracts of herring (Clupea harengus) muscle has been established. An acid treatment of crude extracts (exposed to pH 3 for 5 min) activated a latent form of cathepsin L and inactivated cathepsin B. Furthermore......). Cathepsin B activity is measured in neutral extract using the specific cathepsin B substrate Z-Arg-Arg-MCA and cathepsin L activity is measured in acid-treated extract with Z-Phe-Arg-MCA as substrate. The specific cathepsin B inhibitor, CA-074, did not inhibit the Z-Arg-Arg-MCA significantly without...

  8. Combined effects of thermal stress and Cd on lysosomal biomarkers and transcription of genes encoding lysosomal enzymes and HSP70 in mussels, Mytilus galloprovincialis

    Energy Technology Data Exchange (ETDEWEB)

    Izagirre, Urtzi; Errasti, Aitzpea; Bilbao, Eider; Múgica, María; Marigómez, Ionan, E-mail: ionan.marigomez@ehu.es

    2014-04-01

    Highlights: • Thermal stress and Cd caused lysosomal enlargement and membrane destabilisation. • hex, gusb and ctsl but not hsp70 were up-regulated at elevated temperature but down-regulated by Cd. • Thermal stress influenced lysosomal responses to Cd exposure. • The presence of Cd jeopardised responsiveness against thermal stress. - Abstract: In estuaries and coastal areas, intertidal organisms may be subject to thermal stress resulting from global warming, together with pollution. In the present study, the combined effects of thermal stress and exposure to Cd were investigated in the endo-lysosomal system of digestive cells in mussels, Mytilus galloprovincialis. Mussels were maintained for 24 h at 18 °C and 26 °C seawater temperature in absence and presence of 50 μg Cd/L seawater. Cadmium accumulation in digestive gland tissue, lysosomal structural changes and membrane stability were determined. Semi-quantitative PCR was applied to reveal the changes elicited by the different experimental conditions in hexosaminidase (hex), β-glucuronidase (gusb), cathepsin L (ctsl) and heat shock protein 70 (hsp70) gene transcription levels. Thermal stress provoked lysosomal enlargement whilst Cd-exposure led to fusion of lysosomes. Both thermal stress and Cd-exposure caused lysosomal membrane destabilisation. hex, gusb and ctsl genes but not hsp70 gene were transcriptionally up-regulated as a result of thermal stress. In contrast, all the studied genes were transcriptionally down-regulated in response to Cd-exposure. Cd bioaccumulation was comparable at 18 °C and 26 °C seawater temperatures but interactions between thermal stress and Cd-exposure were remarkable both in lysosomal biomarkers and in gene transcription. hex, gusb and ctsl genes, reacted to elevated temperature in absence of Cd but not in Cd-exposed mussels. Therefore, thermal stress resulting from global warming might influence the use and interpretation of lysosomal biomarkers in marine pollution

  9. Human cathepsin L rescues the neurodegeneration and lethality incathepsin B/L double deficient mice

    Energy Technology Data Exchange (ETDEWEB)

    Sevenich, Lisa; Pennacchio, Len A.; Peters, Christoph; Reinheckel, Thomas

    2006-01-09

    Cathepsin B (CTSB) and cathepsin L (CTSL) are two widelyexpressed cysteine proteases thought to predominantly reside withinlysosomes. Functional analysis of CTSL in humans is complicated by theexistence of two CTSL-like homologues (CTSL and CTSL2), in contrast tomice which contain only one CTSL enzyme. Thus transgenic expression ofhuman CTSL in CTSL deficient mice provides an opportunity to study the invivo functions of this human protease without interference by its highlyrelated homologue. While mice with single gene deficiencies for murineCTSB or CTSL survive without apparent neuromuscular impairment, murineCTSB/CTSL double deficient mice display degeneration of cerebellarPurkinje cells and neurons of the cerebral cortex, resulting in severehypotrophy, motility defects, and lethality during their third to fourthweek of life. Here we show that expression of human CTSL through agenomic transgene results in widespread expression of human CTSL in themouse which is capable of rescuing the lethality found in CTSB/CTSLdouble-deficient animals. Human CTSL is expressed in the brain of thesecompound mutants predominantly in neurons of the cerebral cortex and inPurkinje cells of the cerebellum, where it appears to prevent neuronalcell death.

  10. Cathepsin S-cleavable, multi-block HPMA copolymers for improved SPECT/CT imaging of pancreatic cancer.

    Science.gov (United States)

    Fan, Wei; Shi, Wen; Zhang, Wenting; Jia, Yinnong; Zhou, Zhengyuan; Brusnahan, Susan K; Garrison, Jered C

    2016-10-01

    This work continues our efforts to improve the diagnostic and radiotherapeutic effectiveness of nanomedicine platforms by developing approaches to reduce the non-target accumulation of these agents. Herein, we developed multi-block HPMA copolymers with backbones that are susceptible to cleavage by cathepsin S, a protease that is abundantly expressed in tissues of the mononuclear phagocyte system (MPS). Specifically, a bis-thiol terminated HPMA telechelic copolymer containing 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) was synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization. Three maleimide modified linkers with different sequences, including cathepsin S degradable oligopeptide, scramble oligopeptide and oligo ethylene glycol, were subsequently synthesized and used for the extension of the HPMA copolymers by thiol-maleimide click chemistry. All multi-block HPMA copolymers could be labeled by (177)Lu with high labeling efficiency and exhibited high serum stability. In vitro cleavage studies demonstrated highly selective and efficient cathepsin S mediated cleavage of the cathepsin S-susceptible multi-block HPMA copolymer. A modified multi-block HPMA copolymer series capable of Förster Resonance Energy Transfer (FRET) was utilized to investigate the rate of cleavage of the multi-block HPMA copolymers in monocyte-derived macrophages. Confocal imaging and flow cytometry studies revealed substantially higher rates of cleavage for the multi-block HPMA copolymers containing the cathepsin S-susceptible linker. The efficacy of the cathepsin S-cleavable multi-block HPMA copolymer was further examined using an in vivo model of pancreatic ductal adenocarcinoma. Based on the biodistribution and SPECT/CT studies, the copolymer extended with the cathepsin S susceptible linker exhibited significantly faster clearance and lower non-target retention without compromising tumor targeting. Overall, these results indicate that

  11. Nanoplatforms for highly sensitive fluorescence detection of cancer-related proteases.

    Science.gov (United States)

    Wang, Hongwang; Udukala, Dinusha N; Samarakoon, Thilani N; Basel, Matthew T; Kalita, Mausam; Abayaweera, Gayani; Manawadu, Harshi; Malalasekera, Aruni; Robinson, Colette; Villanueva, David; Maynez, Pamela; Bossmann, Leonie; Riedy, Elizabeth; Barriga, Jenny; Wang, Ni; Li, Ping; Higgins, Daniel A; Zhu, Gaohong; Troyer, Deryl L; Bossmann, Stefan H

    2014-02-01

    Numerous proteases are known to be necessary for cancer development and progression including matrix metalloproteinases (MMPs), tissue serine proteases, and cathepsins. The goal of this research is to develop an Fe/Fe3O4 nanoparticle-based system for clinical diagnostics, which has the potential to measure the activity of cancer-associated proteases in biospecimens. Nanoparticle-based "light switches" for measuring protease activity consist of fluorescent cyanine dyes and porphyrins that are attached to Fe/Fe3O4 nanoparticles via consensus sequences. These consensus sequences can be cleaved in the presence of the correct protease, thus releasing a fluorescent dye from the Fe/Fe3O4 nanoparticle, resulting in highly sensitive (down to 1 × 10(-16) mol l(-1) for 12 proteases), selective, and fast nanoplatforms (required time: 60 min).

  12. Activated cathepsin L is associated with the switch from autophagy to apoptotic death of SH-SY5Y cells exposed to 6-hydroxydopamine

    Energy Technology Data Exchange (ETDEWEB)

    Li, Lingyun, E-mail: lingyunlee@126.com [Department of Pharmacology, College of Pharmaceutical Sciences, Soochow University, Suzhou 215123 (China); Experimental Center, The Second Affiliated Hospital of Soochow University, Suzhou 215004 (China); Gao, Luyan [Experimental Center, The Second Affiliated Hospital of Soochow University, Suzhou 215004 (China); Song, Yunzhen; Qin, Zheng-Hong [Department of Pharmacology, College of Pharmaceutical Sciences, Soochow University, Suzhou 215123 (China); Liang, Zhongqin, E-mail: liangzhongqin@suda.edu.cn [Department of Pharmacology, College of Pharmaceutical Sciences, Soochow University, Suzhou 215123 (China)

    2016-02-12

    Autophagy and apoptosis are common responses to pathological damage in the process of Parkinson's disease (PD), and lysosome dysfunction may contribute to the etiology of PD's neurodegenerative process. In this study, we demonstrated that the neurotoxin 6-hydroxydopamine (6-OHDA) increased autophagy in SH-SY5Y cells, as determined by detection of the lysosome marker lysosomal-associated membrane protein1, the autophagy protein light chain 3 (LC3)-II and the autophagy substrate P62 protein. Meanwhile, autophagy repression with 3-methyladenine accelerated the activation of caspase-3 and PARP and aggravated the cell apoptotic death induced by 6-OHDA. Furthermore, we found that 6-OHDA treatment resulted in a transient increase in the intracellular and nuclear expression of cathepsin L (CTSL). The CTSL inhibitor, Z-FY-CHO, could promote autophagy, decrease accumulation of P62, and block activation of caspase-3 and PARP. Taken together, these results suggest that activation of autophagy may primarily be a protective process in SH-SY5Y cell death induced by 6-OHDA, and the nuclear translocation of CTSL could enhance the cell apoptotic cascade via disturbing autophagy-apoptotic systems in SH-SY5Y cells. Our findings highlight the potential role of CTSL in the cross talk between autophagy and apoptosis, which might be considered a therapeutic strategy for treatment of pathologic conditions associated with neurodegeneration. - Highlights: • Inhibition of autophagy aggravated the cell apoptotic death in SH-SY5Y cells. • Activation of cathepsin L impaired the autophagy pathway. • Activation of cathepsin L enhanced the cell apoptotic cascade. • Cathepsin L involves in the cross talk between autophagy and apoptosis.

  13. Significance and prognostic value of lysosomal enzyme activities measured in surgically operated adenocarcinomas of the gastroesophageal junction and squamous cell carcinomas of the lower third of esophagus

    Institute of Scientific and Technical Information of China (English)

    Aron Altorjay; Balazs Paal; Nicolette Sohar; Janos Kiss; Imre Szanto; Istvan Sohar

    2005-01-01

    AIM: To establish whether there are fundamental differences in the biochemistries of adenocarcinomas of the gastroesophageal junction (GEJ) and the squamous cell carcinomas of the lower third of the esophagus (LTE).METHODS: Between February 1, 1997 and February 1,2000, we obtained tissue samples at the moment of resection from 54 patients for biochemical analysis. The full set of data could be comprehensively analyzed in 47 of 54 patients' samples (81%). Of these, 29 were adenocarcinomas of the GEJ Siewert type Ⅰ (n = 8), type Ⅱ (n = 12), type Ⅲ (n = 9), and 18 presented as squamous cell carcinomas of the LTE. We evaluated the mean values of 11-lysosomal enzyme and 1-cytosol protease activities of the tumorous and surrounding mucosae as well as their relative activities, measured as the ratio of activity in tumor and normal tissues from the same patient.These data were further analyzed to establish the correlation with tumor localization, TNM stage (lymph-node involvement), histological type (papillary, signet-ring cell,tubular), state of differentiation (good, moderate, poor),and survival (≤24 or ≥24 mo).RESULTS: In adenocarcinomas, the activity of α-mannosidase (AMAN), cathepsin B (CB) and dipeptidyl-peptidase Ⅰ (DPP Ⅰ) increased significantly as compared to the normal gastric mucosa. In squamous cell carcinomas of the esophagus, we also found a significant difference in the activity of cathepsin L and tripeptidyl-peptidase I in addition to these three. There was a statistical correlation of AMAN,CB, and DPP Ⅰ activity between the level of differentiation of adenocarcinomas of the GEJ and lymph node involvement,because tumors with no lymph node metastases histologically confirmed as well-differentiated, showed a significantly lower activity. The differences in CB and DPP Ⅰ activity correlated well with the differences in survival rates, since the CB and DPP Ⅰ values of those who died within 24 mo following surgical intervention were

  14. Structural basis for the immunomodulatory function of cysteine protease inhibitor from human roundworm Ascaris lumbricoides.

    Science.gov (United States)

    Mei, Guoqiang; Dong, Jianmei; Li, Zhaotao; Liu, Sanling; Liu, Yunfeng; Sun, Mingze; Liu, Guiyun; Su, Zhong; Liu, Jinsong

    2014-01-01

    Immunosuppression associated with infections of nematode parasites has been documented. Cysteine protease inhibitor (CPI) released by the nematode parasites is identified as one of the major modulators of host immune response. In this report, we demonstrated that the recombinant CPI protein of Ascaris lumbricoides (Al-CPI) strongly inhibited the activities of cathepsin L, C, S, and showed weaker effect to cathepsin B. Crystal structure of Al-CPI was determined to 2.1 Å resolution. Two segments of Al-CPI, loop 1 and loop 2, were proposed as the key structure motifs responsible for Al-CPI binding with proteases and its inhibitory activity. Mutations at loop 1 and loop 2 abrogated the protease inhibition activity to various extents. These results provide the molecular insight into the interaction between the nematode parasite and its host and will facilitate the development of anthelmintic agents or design of anti-autoimmune disease drugs.

  15. Calciurn/lysosome pathway in the apoptosis of SGC-7901 cells induced by Wuxing soup%五行汤经钙离子/溶酶体途径介导的SGC-7901细胞凋亡

    Institute of Scientific and Technical Information of China (English)

    莫非; 胡晶莹; 甘愉; 赵仰星; 朱明洁; 赵新泰; 段友容

    2011-01-01

    Objective To explore the mechanism of calcium/lysosome pathway in the apoptosis of SGC-7901 cells induced by Wuxing soup. Methods The integrity of lysosome membrane was detected by acridine orange (AO) staining,the key proteins in apoptotic pathway were tested by Western blot, and the effect of inhibitors on cell apoptotic rate and survival rate was analyzed by Annexin V-binding ELISA and CCK-8, respectively. Results The leakage of lysosome membrane was observed by AO staining. The lysosome associated apoptotic protein Cathepsin D and Cathepsin B were released into cytosol. The inhibitors of Cathepsin B, L and S exerted protection in the survival of SGC-7901 under Wuxing soup treatment in a dose-dependent manner. However, the inhibitor of Cathepsin D had no effects on apoptosis.Conclusion Wuxing soup could induce SGC-7901 cell apoptosis through calcium mediated and lysosome involved caspase-independent pathway.%目的 探索五行汤经钙离子/溶酶体途径介导的SGC-7901细胞凋亡机制.方法 吖啶橙染色检测溶酶体膜完整性,胞浆蛋白免疫印迹法检测凋亡途径蛋白变化,Annexin V结合实验和CCK-8法检测不同抑制剂对细胞凋亡和存活的影响.结果 凋亡细胞的溶酶体膜渗漏,溶酶休释放蛋白酶Cathepsin D和Cathepsin B至胞浆.天冬氨酸蛋白酶Cathepsin D抑制剂对五行汤诱导的细胞凋亡无影响;半胱氨酸蛋白酶Cathepsin B、L、S抑制荆可明显减少细胞凋亡(P<0.05),且对细胞的保护作用呈浓度依赖性.结论 五行汤经钙离子/溶酶体途径介导SGC-7901细胞凋亡.

  16. Synthesis and extended activity of triazole-containing macrocyclic protease inhibitors

    DEFF Research Database (Denmark)

    Pehere, A.D.; Pietsch, M.; Gütschow, M.;

    2013-01-01

    Peptide-derived protease inhibitors are an important class of compounds with the potential to treat a wide range of diseases. Herein, we describe the synthesis of a series of triazole- containing macrocyclic protease inhibitors pre-organized into a b-strand conformation and an evaluation...... of their activity against a panel of proteases. Acyclic azidoalkyne-based aldehydes are also evaluated for comparison. The macrocyclic peptidomimetics showed considerable activity towards calpain II, cathepsin L and S, and the 20S proteasome chymotrypsin-like activity. Some of the first examples of highly potent...

  17. [Activity of cathepsin D in the blood serum and urine of patients with cancer of the stomach, pancreas and liver].

    Science.gov (United States)

    Szajda, Sławomir Dariusz; Snarska, Jadwiga; Roszkowska-Jakimiec, Wiesława; Waszkiewicz, Napoleon; Siedlecka, Katarzyna; Zwierz, Krzysztof; Krupkowska, Agnieszka

    2006-12-01

    Cathepsin D is a protease involved in invasion of the cancer and metastasis formation. The purpose of the study was to evaluate a prognostic value of cathepsin D activity in blood serum and urine of patients with cancer of the stomach, pancreas and liver. The study was carried out on the samples of blood serum and urine obtained from patients with cancer of the stomach, pancreas and liver treated surgically at the First Department of General Surgery and Endocrinology of the Medical University of Białystok. The control group consisted of healthy individuals. Activity of cathepsin D was determined in serum and urine by the Folin-Ciocaltau method with the cupric modification and was expressed in nmol Tyr/ml/6h. Specific activity of cathepsin D was determined in the urine, and was expressed in nmol Tyr/mg of protein/6h. Protein concentration in serum was assessed with Lowry et al. method and results were expressed in mg/ml. A significant increase in activity of cathepsin D in serum (p = 0.0169) and urine (p = 0.0008) and an enhanced specific activity in the urine (p = 0.0085) was found in patients with cancer of the pancreas as compared with the controls. A significantly increased activity of cathepsin was revealed in serum (p = 0.0233) of patients with cancer of the stomach. No significant differences of cathepsin D activity were found in urine of the patients with cancer of the stomach when compared to the controls. Additionally, an upward tendency (almost two-fold increase) of cathepsin D activity was shown in blood serum and an increase in the activity and in specific activity was observed in urine of both patients with cancer of the liver in comparison with the healthy individuals. There were no significant differences in the activity of cathepsin D in serum of the patients with cancer of the pancreas and stomach (p = 0.4156). A statistically significantly higher activity (p = 0.0004) and specific (0.0048) cathepsin D activity was demonstrated in urine of the

  18. The expression of matrix metalloproteinase 9 and cathepsin B in gastric carcinoma is associated with lymph node metastasis, but not with postoperative survival.

    Directory of Open Access Journals (Sweden)

    Roman Bandurski

    2008-02-01

    Full Text Available Degradation components of basement membrane could be crucial for tumor invasion. A key role in this process has been assigned to cysteine proteases, i.e. cathepsins and matrix metalloproteinases. The purpose of this study was to investigate the relationship of the expression of MMP-9 and cathepsin B with tumor aggressiveness expressed by lymph node metastases and survival rates in gastric carcinoma patients. Slides of 5 mum-thick serial sections from 91 patients with primary gastric carcinoma were prepared and analyzed for MMP-9 and cathepsin B expression using anti-human monoclonal antibody (NCL-MMP-9 clone; dilution 1:40 and NCL-CATH-B clone; dilution 1:40. The patients were clinically monitored for 84 months. We found no association between the expression of MMP-9 and cathepsin B in main mass of tumor and patients' gender, tumor location, Lauren's classification or histological differentiation. Also no correlation was observed between the expression of MMP-9 in main mass of tumor and depth of invasion. A strong statistically significant association was found between the expression of MMP-9 and cathepsin B in main mass of tumor and lymph node involvement (p<0.001; p<0.001, respectively. However, we observed no correlation between the expression of MMP-9 and cathepsin B in main mass of tumor and lymph node involvement or 5-year overall survival. Our results may suggest that the expression of matrix metalloproteinase-9 (MMP-9 and cathepsin B is correlated with lymph node metastasis in advanced gastric carcinoma, but not with patients' postoperative survival.

  19. Identification of cytoskeleton-associated proteins essential for lysosomal stability and survival of human cancer cells

    DEFF Research Database (Denmark)

    Groth-Pedersen, Line; Aits, Sonja; Corcelle-Termeau, Elisabeth

    2012-01-01

    Microtubule-disturbing drugs inhibit lysosomal trafficking and induce lysosomal membrane permeabilization followed by cathepsin-dependent cell death. To identify specific trafficking-related proteins that control cell survival and lysosomal stability, we screened a molecular motor siRNA library...... in human MCF7 breast cancer cells. SiRNAs targeting four kinesins (KIF11/Eg5, KIF20A, KIF21A, KIF25), myosin 1G (MYO1G), myosin heavy chain 1 (MYH1) and tropomyosin 2 (TPM2) were identified as effective inducers of non-apoptotic cell death. The cell death induced by KIF11, KIF21A, KIF25, MYH1 or TPM2 si......), increased dextran accumulation (KIF20A), or reduced autophagic flux (MYO1G, MYH1). Importantly, all seven siRNAs also killed human cervix cancer (HeLa) and osteosarcoma (U-2-OS) cells and sensitized cancer cells to other lysosome-destabilizing treatments, i.e. photo-oxidation, siramesine, etoposide...

  20. Phototoxic effects of lysosome-associated genetically encoded photosensitizer KillerRed

    Science.gov (United States)

    Serebrovskaya, Ekaterina O.; Ryumina, Alina P.; Boulina, Maria E.; Shirmanova, Marina V.; Zagaynova, Elena V.; Bogdanova, Ekaterina A.; Lukyanov, Sergey A.; Lukyanov, Konstantin A.

    2014-07-01

    KillerRed is a unique phototoxic red fluorescent protein that can be used to induce local oxidative stress by green-orange light illumination. Here we studied phototoxicity of KillerRed targeted to cytoplasmic surface of lysosomes via fusion with Rab7, a small GTPase that is known to be attached to membranes of late endosomes and lysosomes. It was found that lysosome-associated KillerRed ensures efficient light-induced cell death similar to previously reported mitochondria- and plasma membrane-localized KillerRed. Inhibitory analysis demonstrated that lysosomal cathepsins play an important role in the manifestation of KillerRed-Rab7 phototoxicity. Time-lapse monitoring of cell morphology, membrane integrity, and nuclei shape allowed us to conclude that KillerRed-Rab7-mediated cell death occurs via necrosis at high light intensity or via apoptosis at lower light intensity. Potentially, KillerRed-Rab7 can be used as an optogenetic tool to direct target cell populations to either apoptosis or necrosis.

  1. WNK4 enhances the degradation of NCC through a sortilin-mediated lysosomal pathway.

    Science.gov (United States)

    Zhou, Bo; Zhuang, Jieqiu; Gu, Dingying; Wang, Hua; Cebotaru, Liudmila; Guggino, William B; Cai, Hui

    2010-01-01

    WNK kinase is a serine/threonine kinase that plays an important role in electrolyte homeostasis. WNK4 significantly inhibits the surface expression of the sodium chloride co-transporter (NCC) by enhancing the degradation of NCC through a lysosomal pathway, but the mechanisms underlying this trafficking are unknown. Here, we investigated the effect of the lysosomal targeting receptor sortilin on NCC expression and degradation. In Cos-7 cells, we observed that the presence of WNK4 reduced the steady-state amount of NCC by approximately half. Co-transfection with truncated sortilin (a dominant negative mutant) prevented this WNK4-induced reduction in NCC. NCC immunoprecipitated with both wild-type sortilin and, to a lesser extent, truncated sortilin. Immunostaining revealed that WNK4 increased the co-localization of NCC with the lysosomal marker cathepsin D, and NCC co-localized with wild-type sortilin, truncated sortilin, and WNK4 in the perinuclear region. These findings suggest that WNK4 promotes NCC targeting to the lysosome for degradation via a mechanism involving sortilin.

  2. An activity of caspase-3 and cathepsin D at the different subtypes of ischemic stroke

    Directory of Open Access Journals (Sweden)

    Наталія Романівна Сохор

    2015-06-01

    Full Text Available Aim of research – To define the dynamics of activity of caspase-3, cathepsin D, apoptosis of leukocytes at the different subtypes of ischemic stroke (IS in an acute period.Methods. There were examined 232 patients in an acute period of ІS: 56 (24,1%- with hemodynamic (HDS, 62 (2,.7% – with atherothrombotic (АТS, 60 (25,9% – with cardioembolic (CЕS і 54 (23,3% – with lacunar stroke (LS. There was defined the number of leukocytes at the stage of apoptosis (ANV+-cells, necrosis (PI+-cells, with an increased content of the active forms of oxygen (AFO+-cells and with lowered mitochondrial potential (Mito+-cells, activity of caspase-3 and cathepsin D.Results. It was established that at all subtypes of IS mitochondrial dysfunction, apoptosis and necrosis of leukocytes are observed on the 1st day it were presented in increase of content of  ANV+-, PI+-, АFO+- and Mito+-cells and were the mostly apparent at ATS.   The highest activity of caspase-3 on the 1st day was noticed at LS it did not correlate with a number of cells at the stage of apoptosis and probably was connected with a predominant impact of caspase-3 on endothelium and with hyperpermeability of hematoencephalic barrier. In patients with ATS an activity of cathepsin D increased during the 1st week of disease that can indicate an activation of lysosomal way of activation of apoptosis that courses parallel to an apoptosis connected with mitochondrial dysfunction.Conclusions.  The different ways of apoptotic cellular death that depends on subtype of stroke activate in an acute period of IS

  3. Cathepsin D (C224T) polymorphism in sporadic and genetic Creutzfeldt-Jakob disease.

    Science.gov (United States)

    Kovacs, Gabor G; Sanchez-Juan, Pascual; Ströbel, Thomas; Schuur, Maaike; Poleggi, Anna; Nocentini, Sara; Giannattasio, Claudia; Belay, Girma; Bishop, Matthew; Capellari, Sabina; Parchi, Piero; Gelpi, Ellen; Gal, Aniko; Bakos, Agnes; Molnar, Maria J; Heinemann, Uta; Zerr, Inga; Knight, Richard S G; Mitrova, Eva; van Duijn, Cornelia; Budka, Herbert

    2010-01-01

    Accumulation of cathepsin D immunoreactive lysosomes correlates with tissue pathology in sporadic Creutzfeldt-Jakob disease (CJD) brains. The C-to-T transition within exon 2 of the cathepsin D (CTSD) gene is associated with altered enzymatic activity. Possession of the TT genotype is a risk factor for variant CJD. To verify the association between the CTSD position 224T allele and the risk for and survival in sporadic and genetic CJD, we genotyped 540 sporadic, 101 genetic CJD, and 723 control individuals. Genotype data and duration of illness were compared using multiple logistic regression and Kruskal-Wallis test. Multivariate survival analysis was performed using Cox's regression model. The distribution of CTSD position 224 alleles was approximately the same in all groups. We observed a trend for shorter survival in sporadic CJD patients harboring the T allele at position 224 of the CTSD gene in particular in sporadic CJD patients with the prion protein gene position 129 MM genotype. We conclude that the CTSD position 224 polymorphism alone is not a significant risk or disease-modifying factor in sporadic or genetic CJD.

  4. Cathepsin B-degradable, NIR-responsive nanoparticulate platform for target-specific cancer therapy

    Science.gov (United States)

    Tarassoli, Sam P.; Martinez de Pinillos Bayona, Alejandra; Pye, Hayley; Mosse, C. Alexander; Callan, John F.; MacRobert, Alexander; McHale, Anthony P.; Nomikou, Nikolitsa

    2017-02-01

    Stimuli-responsive anticancer formulations can promote drug release and activation within the target tumour, facilitate cellular uptake, as well as improve the therapeutic efficacy of drugs and reduce off-target effects. In the present work, indocyanine green (ICG)-containing polyglutamate (PGA) nanoparticles were developed and characterized. Digestion of nanoparticles with cathepsin B, a matrix metalloproteinase overexpressed in the microenvironment of advanced tumours, decreased particle size and increased ICG cellular uptake. Incorporation of ICG in PGA nanoparticles provided the NIR-absorbing agent with time-dependent altered optical properties in the presence of cathepsin B. Having minimal dark toxicity, the formulation exhibited significant cytotoxicity upon NIR exposure. Combined use of the formulation with saporin, a ribosome-inactivating protein, resulted in synergistically enhanced cytotoxicity attributed to the photo-induced release of saporin from endo/lysosomes. The results suggest that this therapeutic approach can offer significant therapeutic benefit in the treatment of superficial malignancies, such as head and neck tumours.

  5. Cathepsin B from the white shrimp Litopenaeus vannamei: cDNA sequence analysis, tissues-specific expression and biological activity.

    Science.gov (United States)

    Stephens, A; Rojo, L; Araujo-Bernal, S; Garcia-Carreño, F; Muhlia-Almazan, A

    2012-01-01

    Cathepsin B is a cystein proteinase scarcely studied in crustaceans. Its function has not been clearly described in shrimp species belonging to the sub-order Dendrobranchiata, which includes the white shrimp Litopenaeus vannamei and other species from the Penaeidae family. Studies on vertebrates suggest that these lysosomal enzymes intracellularly hydrolize protein, as other cystein proteinases. However, the expression of the gene encoding the shrimp cathepsin B in the midgut gland was affected by starvation in a similar way as other digestive proteinases which extracellularly hydrolyze food protein. In this study the white shrimp L. vannamei cathepsin B (LvCathB) cDNA was sequenced, and characterized. Its gene expression was evaluated in various shrimp tissues, and changes in the mRNA amounts were compared with those observed on other digestive proteinases from the midgut gland during starvation. By using qRT-PCR it was found that LvCathB is expressed in most shrimp tissues except in pleopods and eye stalk. Changes on LvCathB mRNA during starvation suggest that the enzyme participates during intracellular protein hydrolysis but also, after food ingestion, it participates in hydrolyzing food proteins extracellularly as confirmed by the high activity levels we found in the gastric juice and midgut gland of the white shrimp.

  6. Excessive activity of cathepsin K is associated with cartilage defects in a zebrafish model of mucolipidosis II

    Directory of Open Access Journals (Sweden)

    Aaron C. Petrey

    2012-03-01

    The severe pediatric disorder mucolipidosis II (ML-II; also known as I-cell disease is caused by defects in mannose 6-phosphate (Man-6-P biosynthesis. Patients with ML-II exhibit multiple developmental defects, including skeletal, craniofacial and joint abnormalities. To date, the molecular mechanisms that underlie these clinical manifestations are poorly understood. Taking advantage of a zebrafish model of ML-II, we previously showed that the cartilage morphogenesis defects in this model are associated with altered chondrocyte differentiation and excessive deposition of type II collagen, indicating that aspects of development that rely on proper extracellular matrix homeostasis are sensitive to decreases in Man-6-P biosynthesis. To further investigate the molecular bases for the cartilage phenotypes, we analyzed the transcript abundance of several genes in chondrocyte-enriched cell populations isolated from wild-type and ML-II zebrafish embryos. Increased levels of cathepsin and matrix metalloproteinase (MMP transcripts were noted in ML-II cell populations. This increase in transcript abundance corresponded with elevated and sustained activity of several cathepsins (K, L and S and MMP-13 during early development. Unlike MMP-13, for which higher levels of protein were detected, the sustained activity of cathepsin K at later stages seemed to result from its abnormal processing and activation. Inhibition of cathepsin K activity by pharmacological or genetic means not only reduced the activity of this enzyme but led to a broad reduction in additional protease activity, significant correction of the cartilage morphogenesis phenotype and reduced type II collagen staining in ML-II embryos. Our findings suggest a central role for excessive cathepsin K activity in the developmental aspects of ML-II cartilage pathogenesis and highlight the utility of the zebrafish system to address the biochemical underpinnings of metabolic disease.

  7. Fluorescent nitrile-based inhibitors of cysteine cathepsins.

    Science.gov (United States)

    Frizler, Maxim; Mertens, Matthias D; Gütschow, Michael

    2012-12-15

    Cysteine cathepsins play an important role in many (patho)physiological conditions. Among them, cathepsins L, S, K and B are subjects of several drug discovery programs. Besides their role as drug targets, cysteine cathepsins are additionally considered to be possible biomarkers for inflammation and cancer. Herein, we describe the design, synthesis, biological evaluation and spectral properties of fluorescently labeled dipeptide- and azadipeptide nitriles. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. IGFBP-4 Anti-Angiogenic and Anti-Tumorigenic Effects Are Associated with Anti-Cathepsin B Activity

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    María J Moreno

    2013-05-01

    Full Text Available Insulin-like growth factor-binding protein 4 (IGFBP-4/IBP-4 has potent IGF-independent anti-angiogenic and antitumorigenic effects. In this study, we demonstrated that these activities are located in the IGFBP-4 C-terminal protein fragment (CIBP-4, a region containing a thyroglobulin type 1 (Tg1 domain. Proteins bearing Tg1 domains have been shown to inhibit cathepsins, lysosomal enzymes involved in basement membrane degradation and implicated in tumor invasion and angiogenesis. In our studies, CIBP-4 was shown to internalize and co-localize with lysosomal-like structures in both endothelial cells (ECs and glioblastoma U87MG cells. CIBP-4 also inhibited both growth factor-induced EC tubulogenesis in Matrigel and the concomitant increases in intracellular cathepsin B (CatB activity. In vitro assays confirmed CIBP-4 capacity to block recombinant CatB activity. Biodistribution analysis of intravenously injected CIBP-4-Cy5.5 in a glioblastoma tumor xenograft model indicated targeted accumulation of CIBP-4 in tumors. Most importantly, CIBP-4 reduced tumor growth in this animal model by 60%. Pleiotropic anti-angiogenic and anti-tumorigenic activities of CIBP-4 most likely underlie its observed therapeutic potential against glioblastoma.

  9. Further characterization of the cathepsin L-associated protein and its gene in two species of the brine shrimp, Artemia.

    Science.gov (United States)

    Liu, Liqian; Warner, Alden H

    2006-12-01

    The major cysteine protease in embryos and larvae of the brine shrimp Artemia franciscana is a heterodimer composed of a cathepsin L-like polypeptide of 28.5 kDa and a 31.5 kDa polypeptide called the cathepsin L-associated protein or CLAP. In a previous study, CLAP was shown to be a cell adhesion protein containing two Fas I domains and two GTP/ATP binding sites known as Walker A and B motifs. Here, we have characterized CLAP and its genes to better understand the role of this protein in Artemia development. The polymerase chain reaction was used to investigate the structure of the CLAP gene in two species of Artemia, the New World bisexual diploid A. franciscana and the Old World parthenogenetic tetraploid Artemia parthenogenetica. The protein coding region of the CLAP gene from each species was 99.5% identical for a protein of 332 amino acids, while the 3' non-coding region, representing nearly 45% of the gene, was only 86% identical between the two related species. However, while the CLAP gene is intronless in A. franciscana, in A. parthenogenetica the gene contained a mini-intron of 30 base pairs in the 3' non-coding region. The sequences representing the CLAP gene in A. franciscana and A. parthenogenetica have been entered into the NCBI database as AY757920 and DQ100385, respectively. Northern blot analysis showed that while the cathepsin L gene is expressed constitutively in Artemia franciscana embryos and young larvae, the CLAP gene is not expressed in late embryos and young larvae. In contrast, Western blots indicated that CLAP is present in developing embryos and young larvae, at least to the first larval molt, supporting results obtained previously showing CLAP's resistance to degradation by its dimeric partner, cathepsin L. At the protein level we showed that the GTP/ATP binding sites in CLAP are functional with rate constants of 0.024 and 0.022 for GTP and ATP hydrolase activity, respectively. GTP but not ATP also had a slight stimulatory effect on

  10. Insecticidal Activity of a Basement Membrane-Degrading Protease against Heliothis virescens (Fabricius) and Acyrthosiphon pisum (Harris)

    Science.gov (United States)

    ScathL is a cathepsin L-like cysteine protease derived from the flesh fly Sarcophaga peregrina that functions in basement membrane (BM) remodeling during insect development. A recombinant baculovirus expressing ScathL (AcMLF9.ScathL) kills larvae of the tobacco budworm, Heliothis virescens, signific...

  11. Exogenous Thyropin from p41 Invariant Chain Diminishes Cysteine Protease Activity and Affects IL-12 Secretion during Maturation of Human Dendritic Cells.

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    Tina Zavašnik-Bergant

    Full Text Available Dendritic cells (DC play a pivotal role as antigen presenting cells (APC and their maturation is crucial for effectively eliciting an antigen-specific immune response. The p41 splice variant of MHC class II-associated chaperone, called invariant chain p41 Ii, contains an amino acid sequence, the p41 fragment, which is a thyropin-type inhibitor of proteolytic enzymes. The effects of exogenous p41 fragment and related thyropin inhibitors acting on human immune cells have not been reported yet. In this study we demonstrate that exogenous p41 fragment can enter the endocytic pathway of targeted human immature DC. Internalized p41 fragment has contributed to the total amount of the immunogold labelled p41 Ii-specific epitope, as quantified by transmission electron microscopy, in particular in late endocytic compartments with multivesicular morphology where antigen processing and binding to MHC II take place. In cell lysates of treated immature DC, diminished enzymatic activity of cysteine proteases has been confirmed. Internalized exogenous p41 fragment did not affect the perinuclear clustering of acidic cathepsin S-positive vesicles typical of mature DC. p41 fragment is shown to interfere with the nuclear translocation of NF-κB p65 subunit in LPS-stimulated DC. p41 fragment is also shown to reduce the secretion of interleukin-12 (IL-12/p70 during the subsequent maturation of treated DC. The inhibition of proteolytic activity of lysosomal cysteine proteases in immature DC and the diminished capability of DC to produce IL-12 upon their subsequent maturation support the immunomodulatory potential of the examined thyropin from p41 Ii.

  12. Molecular Dynamics Simulations of Ligand-Induced Flap Conformational Changes in Cathepsin-D-A Comparative Study.

    Science.gov (United States)

    Arodola, Olayide A; Soliman, Mahmoud E S

    2016-11-01

    The flap region in aspartic proteases is a unique structural feature to this class of enzymes, and found to have a profound impact on protein overall structure, function, and dynamics. Understanding the structure and dynamic behavior of the flap regions is crucial in the design of selective inhibitors against aspartic proteases. Cathepsin-D, an aspartic protease enzyme, has been implicated in a long list of degenerative diseases as well as breast cancer progression. Presented herein, for the first time, is a comprehensive description of the conformational flap dynamics of cathepsin-D using a comparative 50 ns "multiple" molecular dynamics simulations. Diverse collective metrics were proposed to accurately define flap dynamics. These are distance d1 between the flap tips residues (Gly79 and Met301); dihedral angle ϕ; in addition to TriCα angles Gly79-Asp33-Asp223, θ1 , and Gly79-Asp223-Met301, θ2 . The maximum distance attained throughout the simulation was 17.42 and 11.47 Å for apo and bound cathepsin-D, respectively, while the minimum distance observed was 8.75 and 6.32 Å for apo and bound cathepsin-D, respectively. The movement of the flap as well as the twist of the active pocket can properly be explained by measuring the angle, θ1 , between Gly79-Asp33-Met301 and correlating it with the distance Cα of the flap tip residues. The asymmetrical opening of the binding cavity was best described by the large shift of -6.26° to +20.94° in the dihedral angle, ϕ, corresponding to the full opening of the flap at a range of 31-33 ns. A wide-range of post-dynamic analyses was also applied in this report to supplement our findings. We believe that this report would augment current efforts in designing potent structure-based inhibitors against cathepsin-D in the treatment of breast cancer and other degenerative diseases. J. Cell. Biochem. 117: 2643-2657, 2016. © 2016 Wiley Periodicals, Inc.

  13. The autophagic- lysosomal pathway determines the fate of glial cells under manganese- induced oxidative stress conditions.

    Science.gov (United States)

    Gorojod, R M; Alaimo, A; Porte Alcon, S; Pomilio, C; Saravia, F; Kotler, M L

    2015-10-01

    Manganese (Mn) overexposure is frequently associated with the development of a neurodegenerative disorder known as Manganism. The Mn-mediated generation of reactive oxygen species (ROS) promotes cellular damage, finally leading to apoptotic cell death in rat astrocytoma C6 cells. In this scenario, the autophagic pathway could play an important role in preventing cytotoxicity. In the present study, we found that Mn induced an increase in the amount and total volume of acidic vesicular organelles (AVOs), a process usually related to the activation of the autophagic pathway. Particularly, the generation of enlarged AVOs was a ROS- dependent event. In this report we demonstrated for the first time that Mn induces autophagy in glial cells. This conclusion emerged from the results obtained employing a battery of autophagy markers: a) the increase in LC3-II expression levels, b) the formation of autophagic vesicles labeled with monodansylcadaverine (MDC) or LC3 and, c) the increase in Beclin 1/ Bcl-2 and Beclin 1/ Bcl-X(L) ratio. Autophagy inhibition employing 3-MA and mAtg5(K130R) resulted in decreased cell viability indicating that this event plays a protective role in Mn- induced cell death. In addition, mitophagy was demonstrated by an increase in LC3 and TOM-20 colocalization. On the other hand, we proposed the occurrence of lysosomal membrane permeabilization (LMP) based in the fact that cathepsins B and D activities are essential for cell death. Both cathepsin B inhibitor (Ca-074 Me) or cathepsin D inhibitor (Pepstatin A) completely prevented Mn- induced cytotoxicity. In addition, low dose of Bafilomycin A1 showed a similar effect, a finding that adds evidence about the lysosomal role in Mn cytotoxicity. Finally, in vivo experiments demonstrated that Mn induces injury and alters LC3 expression levels in rat striatal astrocytes. In summary, our results demonstrated that autophagy is activated to counteract the harmful effect caused by Mn. These data is valuable to

  14. First-Generation Antipsychotic Haloperidol Alters the Functionality of the Late Endosomal/Lysosomal Compartment in Vitro.

    Science.gov (United States)

    Canfrán-Duque, Alberto; Barrio, Luis C; Lerma, Milagros; de la Peña, Gema; Serna, Jorge; Pastor, Oscar; Lasunción, Miguel A; Busto, Rebeca

    2016-03-18

    First- and second-generation antipsychotics (FGAs and SGAs, respectively), have the ability to inhibit cholesterol biosynthesis and also to interrupt the intracellular cholesterol trafficking, interfering with low-density lipoprotein (LDL)-derived cholesterol egress from late endosomes/lysosomes. In the present work, we examined the effects of FGA haloperidol on the functionality of late endosomes/lysosomes in vitro. In HepG2 hepatocarcinoma cells incubated in the presence of 1,1'-dioctadecyl-3,3,3,3'-tetramethylindocarbocyanineperchlorate (DiI)-LDL, treatment with haloperidol caused the enlargement of organelles positive for late endosome markers lysosome-associated membrane protein 2 (LAMP-2) and LBPA (lysobisphosphatidic acid), which also showed increased content of both free-cholesterol and DiI derived from LDL. This indicates the accumulation of LDL-lipids in the late endosomal/lysosomal compartment caused by haloperidol. In contrast, LDL traffic through early endosomes and the Golgi apparatus appeared to be unaffected by the antipsychotic as the distribution of both early endosome antigen 1 (EEA1) and coatomer subunit β (β-COP) were not perturbed. Notably, treatment with haloperidol significantly increased the lysosomal pH and decreased the activities of lysosomal protease and β-d-galactosidase in a dose-dependent manner. We conclude that the alkalinization of the lysosomes' internal milieu induced by haloperidol affects lysosomal functionality.

  15. Biomarkers in Lysosomal Storage Diseases

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    Joaquin Bobillo Lobato

    2016-12-01

    Full Text Available A biomarker is generally an analyte that indicates the presence and/or extent of a biological process, which is in itself usually directly linked to the clinical manifestations and outcome of a particular disease. The biomarkers in the field of lysosomal storage diseases (LSDs have particular relevance where spectacular therapeutic initiatives have been achieved, most notably with the introduction of enzyme replacement therapy (ERT. There are two main types of biomarkers. The first group is comprised of those molecules whose accumulation is directly enhanced as a result of defective lysosomal function. These molecules represent the storage of the principal macro-molecular substrate(s of a specific enzyme or protein, whose function is deficient in the given disease. In the second group of biomarkers, the relationship between the lysosomal defect and the biomarker is indirect. In this group, the biomarker reflects the effects of the primary lysosomal defect on cell, tissue, or organ functions. There is no “gold standard” among biomarkers used to diagnosis and/or monitor LSDs, but there are a number that exist that can be used to reasonably assess and monitor the state of certain organs or functions. A number of biomarkers have been proposed for the analysis of the most important LSDs. In this review, we will summarize the most promising biomarkers in major LSDs and discuss why these are the most promising candidates for screening systems.

  16. Plasma levels of cathepsins L, K, and V and risks of abdominal aortic aneurysms

    DEFF Research Database (Denmark)

    Lv, Bing-Jie; Lindholt, Jes S; Wang, Jing;

    2013-01-01

    Cathepsin L (CatL), cathepsin K (CatK), and cathepsin V (CatV) are potent elastases implicated in human arterial wall remodeling. Whether plasma levels of these cathepsins are altered in patients with abdominal aortic aneurysms (AAAs) remains unknown.......Cathepsin L (CatL), cathepsin K (CatK), and cathepsin V (CatV) are potent elastases implicated in human arterial wall remodeling. Whether plasma levels of these cathepsins are altered in patients with abdominal aortic aneurysms (AAAs) remains unknown....

  17. Cathepsin-S degraded decorin are elevated in fibrotic lung disorders - development and biological validation of a new serum biomarker

    DEFF Research Database (Denmark)

    Kehlet, Stephanie Nina; Bager, C. L.; Willumsen, N.

    2017-01-01

    by determining the inter-and intra-assay precision, dilution recovery, accuracy, analyte stability and interference. Serum levels were assessed in lung cancer patients, patients with idiopathic pulmonary fibrosis (IPF), patients with chronic obstructive pulmonary disease (COPD) and healthy controls...... controls was 0.96 and 0.77, respectively.Conclusion: Cathepsin-S degraded decorin could be quantified in serum using the DCN-CS competitive ELISA. The clinical data indicated that degradation of decorin by cathepsin-S is an important part of the pathology of lung cancer and IPF....

  18. Defective lysosomal proteolysis and axonal transport are early pathogenic events that worsen with age leading to increased APP metabolism and synaptic Abeta in transgenic APP/PS1 hippocampus

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    Torres Manuel

    2012-11-01

    Full Text Available Abstract Background Axonal pathology might constitute one of the earliest manifestations of Alzheimer disease. Axonal dystrophies were observed in Alzheimer’s patients and transgenic models at early ages. These axonal dystrophies could reflect the disruption of axonal transport and the accumulation of multiple vesicles at local points. It has been also proposed that dystrophies might interfere with normal intracellular proteolysis. In this work, we have investigated the progression of the hippocampal pathology and the possible implication in Abeta production in young (6 months and aged (18 months PS1(M146L/APP(751sl transgenic mice. Results Our data demonstrated the existence of a progressive, age-dependent, formation of axonal dystrophies, mainly located in contact with congophilic Abeta deposition, which exhibited tau and neurofilament hyperphosphorylation. This progressive pathology was paralleled with decreased expression of the motor proteins kinesin and dynein. Furthermore, we also observed an early decrease in the activity of cathepsins B and D, progressing to a deep inhibition of these lysosomal proteases at late ages. This lysosomal impairment could be responsible for the accumulation of LC3-II and ubiquitinated proteins within axonal dystrophies. We have also investigated the repercussion of these deficiencies on the APP metabolism. Our data demonstrated the existence of an increase in the amyloidogenic pathway, which was reflected by the accumulation of hAPPfl, C99 fragment, intracellular Abeta in parallel with an increase in BACE and gamma-secretase activities. In vitro experiments, using APPswe transfected N2a cells, demonstrated that any imbalance on the proteolytic systems reproduced the in vivo alterations in APP metabolism. Finally, our data also demonstrated that Abeta peptides were preferentially accumulated in isolated synaptosomes. Conclusion A progressive age-dependent cytoskeletal pathology along with a reduction of

  19. Characterization of two cysteine proteases secreted by Blastocystis ST7, a human intestinal parasite.

    Science.gov (United States)

    Wawrzyniak, Ivan; Texier, Catherine; Poirier, Philippe; Viscogliosi, Eric; Tan, Kevin S W; Delbac, Frédéric; El Alaoui, Hicham

    2012-09-01

    Blastocystis spp. are unicellular anaerobic intestinal parasites of both humans and animals and the most prevalent ones found in human stool samples. Their association with various gastrointestinal disorders raises the questions of its pathogenicity and of the molecular mechanisms involved. Since secreted proteases are well-known to be implicated in intestinal parasite virulence, we intended to determine whether Blastocystis spp. possess such pathogenic factors. In silico analysis of the Blastocystis subtype 7 (ST7) genome sequence highlighted 22 genes coding proteases which were predicted to be secreted. We characterized the proteolytic activities in the secretory products of Blastocystis ST7 using specific protease inhibitors. Two cysteine proteases, a cathepsin B and a legumain, were identified in the parasite culture supernatant by gelatin zymographic SDS-PAGE gel and MS/MS analysis. These proteases might act on intestinal cells and disturb gut function. This work provides serious molecular candidates to link Blastocystis spp. and intestinal disorders.

  20. Regulation of split anergy in natural killer cells by inhibition of cathepsins C and H and cystatin F.

    Science.gov (United States)

    Magister, Špela; Tseng, Han-Ching; Bui, Vickie T; Kos, Janko; Jewett, Anahid

    2015-09-01

    Freshly isolated human primary NK cells induce preferential lysis of Oral Squamous Carcinoma Stem Cells (OSCSCs) when compared to differentiated Oral Squamous Carcinoma Cells (OSCCs), while anti-CD16 antibody and monocytes induce functional split anergy in primary NK cells by decreasing the cytotoxic function of NK cells and increasing the release of IFN-γ. Since NK92 cells have relatively lower levels of cytotoxicity when compared to primary NK cells, and have the ability to increase secretion of regulatory cytokines IL-10 and IL-6, we used these cells as a model of NK cell anergy to identify and to study the upstream regulators of anergy. We demonstrate in this paper that the levels of truncated monomeric cystatin F, which is known to inhibit the functions of cathepsins C and H, is significantly elevated in NK92 cells and in anergized primary NK cells. Furthermore, cystatin F co-localizes with cathepsins C and H in the lysosomal/endosomal vesicles of NK cells. Accordingly, the mature forms of aminopeptidases cathepsins C and H, which regulate the activation of effector granzymes in NK cells, are significantly decreased, whereas the levels of pro-cathepsin C enzyme is increased in anergized NK cells after triggering of the CD16 receptor. In addition, the levels of granzyme B is significantly decreased in anti-CD16mAb and target cell anergized primary NK cells and NK92 cells. Our study provides the cellular and molecular mechanisms by which target cells may utilize to inhibit the cytotoxic function of NK cells.

  1. The 3D structure and function of digestive cathepsin L-like proteinases of Tenebrio molitor larval midgut.

    Science.gov (United States)

    Beton, Daniela; Guzzo, Cristiane R; Ribeiro, Alberto F; Farah, Chuck S; Terra, Walter R

    2012-09-01

    Cathepsin L-like proteinases (CAL) are major digestive proteinases in the beetle Tenebrio molitor. Procathepsin Ls 2 (pCAL2) and 3 (pCAL3) were expressed as recombinant proteins in Escherichia coli, purified and activated under acidic conditions. Immunoblot analyses of different T. molitor larval tissues demonstrated that a polyclonal antibody to pCAL3 recognized pCAL3 and cathepsin L 3 (CAL3) only in the anterior two-thirds of midgut tissue and midgut luminal contents of T. molitor larvae. Furthermore, immunocytolocalization data indicated that pCAL3 occurs in secretory vesicles and microvilli in anterior midgut. Therefore CAL3, like cathepsin L 2 (CAL2), is a digestive enzyme secreted by T. molitor anterior midgut. CAL3 hydrolyses Z-FR-MCA and Z-RR-MCA (typical cathepsin substrates), whereas CAL2 hydrolyses only Z-FR-MCA. Active site mutants (pCAL2C25S and pCAL3C26S) were constructed by replacing the catalytic cysteine with serine to prevent autocatalytic processing. Recombinant pCAL2 and pCAL3 mutants (pCAL2C25S and pCAL3C26S) were prepared, crystallized and their 3D structures determined at 1.85 and 2.1 Å, respectively. While the overall structure of these enzymes is similar to other members of the papain superfamily, structural differences in the S2 subsite explain their substrate specificities. The data also supported models for CAL trafficking to lysosomes and to secretory vesicles to be discharged into midgut contents.

  2. The highly antigenic 53/25 kDa Taenia solium protein fraction with cathepsin-L like activity is present in the oncosphere/cysticercus and induces non-protective IgG antibodies in pigs.

    Science.gov (United States)

    Zimic, Mirko; Pajuelo, Mónica; Gilman, Robert H; Gutiérrez, Andrés H; Rueda, Luis D; Flores, Myra; Chile, Nancy; Verástegui, Manuela; Gonzalez, Armando; García, Héctor H; Sheen, Patricia

    2012-01-15

    Cathepsin L-like proteases are secreted by several parasites including Taenia solium. The mechanism used by T. solium oncospheres to degrade and penetrate the intestine and infect the host is incompletely understood. It is assumed that intestinal degradation is driven by the proteolytic activity of enzymes secreted by the oncosphere. Blocking the proteolytic activity by an antibody response would prevent the oncosphere penetration and further infection. Serine and cysteine proteases including chymotrypsin, trypsin, elastase, and cathepsin L, are secreted by T. solium and Taenia saginata oncospheres when cultured in vitro, being potential vaccine candidates. However, the purification of a sufficient quantity of proteases secreted by oncospheres to conduct a vaccine trial is costly and lengthy. A 53/25 kDa cathepsin L-like fraction partially purified from T. solium cyst fluid was described previously as an important antigen for immunodiagnostics. In this study we found that this antigen is present in the T. solium oncosphere and is also secreted by the cysticercus. This protein fraction was tested for its ability to protect pigs against an oral challenge with T. solium oncospheres in a vaccine trial. IgG antibodies against the 53/25 kDa cathepsin L-like protein fraction were elicited in the vaccinated animals but did not confer protection.

  3. Cathepsin B mediates caspase-independent cell death induced by microtubule stabilizing agents in non-small cell lung cancer cells.

    NARCIS (Netherlands)

    Broker, L.E.; Huisman, C.; Span, SW; Rodriguez, J.A.; Kruyt, F.A.E.; Giaccone, G.

    2004-01-01

    We have previously reported that the microtubule stabilizing agents (MSAs) paclitaxel, epothilone B and discodermolide induce caspase-independent cell death in non-small cell lung cancer (NSCLC) cells. Here we present two lines of evidence indicating a central role for the lysosomal protease catheps

  4. Proteases as Insecticidal Agents

    OpenAIRE

    Robert L. Harrison; Bonning, Bryony C.

    2010-01-01

    Proteases from a variety of sources (viruses, bacteria, fungi, plants, and insects) have toxicity towards insects. Some of these insecticidal proteases evolved as venom components, herbivore resistance factors, or microbial pathogenicity factors, while other proteases play roles in insect development or digestion, but exert an insecticidal effect when over-expressed from genetically engineered plants or microbial pathogens. Many of these proteases are cysteine proteases, although insect-toxic...

  5. Brief exposure to copper activates lysosomal exocytosis.

    Science.gov (United States)

    Peña, Karina; Coblenz, Jessica; Kiselyov, Kirill

    2015-04-01

    Copper (Cu) is essential mineral, but its toxicity necessitates existence of powerful machinery responsible for the extraction of excess Cu from the cell. Cu exposure was recently shown to induce the translocation of Cu pump ATP7B to the lysosomes followed by lysosomal exocytosis. Here we sought to investigate the mechanisms underlying the effect of Cu on lysosomal exocytosis. We found that brief exposure to Cu activates lysosomal exocytosis, which was measured as a release of the lysosomal digestive enzyme β-hexosaminidase (β-hex) into the extracellular medium and by the presence lysosomal protein LAMP1 at the plasma membrane. Such release depends on calcium (Ca) and on the lysosomal SNARE VAMP7. ATP7B knockdown using RNAi suppressed the basal lysosomal exocytosis, but did not affect the ability of Cu to activate it. ATP7B knockdown was associated with sustained oxidative stress. The removal of Ca from the extracellular medium suppressed the Cu-dependent component of the lysosomal exocytosis. We propose that Cu promotes lysosomal exocytosis by facilitating a Ca-dependent step of the lysosomal exocytosis.

  6. Mitigating role of baicalein on lysosomal enzymes and xenobiotic metabolizing enzyme status during lung carcinogenesis of Swiss albino mice induced by benzo(a)pyrene.

    Science.gov (United States)

    Naveenkumar, Chandrashekar; Raghunandakumar, Subramanian; Asokkumar, Selvamani; Binuclara, John; Rajan, Balan; Premkumar, Thandavamoorthy; Devaki, Thiruvengadam

    2014-06-01

    The lungs mainly serve as a primary site for xenobiotic metabolism and constitute an important defense mechanism against inhalation of carcinogens. Our current study aimed to evaluate the chemotherapeutic efficacy of baicalein (BE) in Swiss albino mice exposed to tobacco-specific carcinogen benzo(a)pyrene [B(a)P] for its ability to mitigate pulmonary carcinogenesis. Here, we report that altered activities/levels of lysosomal enzymes (cathepsin-D, cathepsin-B, acid phosphatase, β-D-galactosidase, β-D-glucuronidase, and β-D-N-acetyl glucosaminidase), phase I biotransformation enzymes (cytochrome P450, cytochrome b5, NADPH-cytochrome P450 reductase, and NADH-cytochrome b5 reductase), and phase II enzymes (glutathione S-transferase, UDP-glucuronyl transferase, and DT-diaphorase) were observed in the B(a)P-induced mice. Treatment with BE significantly restored back the activities/levels of lysosomal enzymes, phase I and phase II biotransformation enzymes. Moreover, assessment of lysosomal abnormalities by transmission electron microscopic examination revealed that BE treatment effectively counteract B(a)P-induced oxidative damages. Protein expression levels studied by immunohistochemistry, immunofluorescence, and immunoblot analysis of CYP1A1 revealed that BE treatment effectively negate B(a)P-induced upregulated expression of CYP1A1. Further analysis of scanning electron microscopic studies in lung was carried out to substantiate the anticarcinogenic effect of BE. The overall data suggest that BE treatment significantly inhibits lysosomal and microsomal dysfunction, thus revealing its potent anticarcinogenic effect.

  7. Effective DNA Inhibitors of Cathepsin G by In Vitro Selection

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    Manlio Palumbo

    2008-06-01

    Full Text Available Cathepsin G (CatG is a chymotrypsin-like protease released upon degranulation of neutrophils. In several inflammatory and ischaemic diseases the impaired balance between CatG and its physiological inhibitors leads to tissue destruction and platelet aggregation. Inhibitors of CatG are suitable for the treatment of inflammatory diseases and procoagulant conditions. DNA released upon the death of neutrophils at injury sites binds CatG. Moreover, short DNA fragments are more inhibitory than genomic DNA. Defibrotide, a single stranded polydeoxyribonucleotide with antithrombotic effect is also a potent CatG inhibitor. Given the above experimental evidences we employed a selection protocol to assess whether DNA inhibition of CatG may be ascribed to specific sequences present in defibrotide DNA. A Selex protocol was applied to identify the single-stranded DNA sequences exhibiting the highest affinity for CatG, the diversity of a combinatorial pool of oligodeoxyribonucleotides being a good representation of the complexity found in defibrotide. Biophysical and biochemical studies confirmed that the selected sequences bind tightly to the target enzyme and also efficiently inhibit its catalytic activity. Sequence analysis carried out to unveil a motif responsible for CatG recognition showed a recurrence of alternating TG repeats in the selected CatG binders, adopting an extended conformation that grants maximal interaction with the highly charged protein surface. This unprecedented finding is validated by our results showing high affinity and inhibition of CatG by specific DNA sequences of variable length designed to maximally reduce pairing/folding interactions.

  8. Inhibition of cathepsin B by E-64 induces oxidative stress and apoptosis in filarial parasite.

    Directory of Open Access Journals (Sweden)

    Mohit Wadhawan

    Full Text Available Current available antifilarial drug strategies only eliminate the larval stages of filarial parasites. Therefore, there is an urgent need of drugs which are macrofilaricidals. Identification of molecular targets crucial for survival of parasite is a prerequisite for drug designing. Cathepsin B, a cysteine protease family member is known to play crucial role in the normal growth, digestion of nutrients, exsheathment of the helminth parasites. Therefore, we targeted this enzyme in the filarial parasite using its specific inhibitor, E-64.We have exposed the parasites to E-64 and observed their motility and viability at various time intervals. It caused marked decrease in the motility and viability of the parasites ultimately leading to their death after 8 hours. It is well known that E-64 protects the cell from apoptosis, however, it causes apoptotic effect in carcinoma cell lines. To understand the mechanism of action of E-64 on parasite survival, we have measured levels of different apoptotic markers in the treated parasites. E-64 significantly reduced the level of ced-9 and activity of tyrosine phosphatases, cytochrome c oxidase. It also activated ced-3, homolog of mammalian caspase 3 suggesting initiation of an apoptotic like event in the filarial parasites. Different antioxidant enzymes were also evaluated to further explore the mechanism behind the death of the parasites. There was marked decrease in the level of GSH and activity of Glutathione reductase and glutathione-s-transferase leading to increased generation of reactive oxygen species. This led to the induced oxidation of fatty acids and protein which might alter the mitochondrial membrane permeability.This study suggests that inhibition of cathepsin B by E-64 generates oxidative stress followed by mitochondrial mediated apoptotic like event in filarial parasites leading to their death. Hence, suggesting filarial cathepsin B as a potential chemotherapeutic target for lymphatic

  9. Glucolipotoxicity diminishes cardiomyocyte TFEB and inhibits lysosomal autophagy during obesity and diabetes.

    Science.gov (United States)

    Trivedi, Purvi C; Bartlett, Jordan J; Perez, Lester J; Brunt, Keith R; Legare, Jean Francois; Hassan, Ansar; Kienesberger, Petra C; Pulinilkunnil, Thomas

    2016-12-01

    Impaired cardiac metabolism in the obese and diabetic heart leads to glucolipotoxicity and ensuing cardiomyopathy. Glucolipotoxicity causes cardiomyocyte injury by increasing energy insufficiency, impairing proteasomal-mediated protein degradation and inducing apoptosis. Proteasome-evading proteins are degraded by autophagy in the lysosome, whose metabolism and function are regulated by master regulator transcription factor EB (TFEB). Limited studies have examined the impact of glucolipotoxicity on intra-lysosomal signaling proteins and their regulators. By utilizing a mouse model of diet-induced obesity, type-1 diabetes (Akita) and ex-vivo model of glucolipotoxicity (H9C2 cells and NRCM, neonatal rat cardiomyocyte), we examined whether glucolipotoxicity negatively targets TFEB and lysosomal proteins to dysregulate autophagy and cause cardiac injury. Despite differential effects of obesity and diabetes on LC3B-II, expression of proteins facilitating autophagosomal clearance such as TFEB, LAMP-2A, Hsc70 and Hsp90 were decreased in the obese and diabetic heart. In-vivo data was recapitulated in H9C2 and NRCM cells, which exhibited impaired autophagic flux and reduced TFEB content when exposed to a glucolipotoxic milieu. Notably, overloading myocytes with a saturated fatty acid (palmitate) but not an unsaturated fatty acid (oleate) depleted cellular TFEB and suppressed autophagy, suggesting a fatty acid specific regulation of TFEB and autophagy in the cardiomyocyte. The effect of glucolipotoxicity to reduce TFEB content was also confirmed in heart tissue from patients with Class-I obesity. Therefore, during glucolipotoxicity, suppression of lysosomal autophagy was associated with reduced lysosomal content, decreased cathepsin-B activity and diminished cellular TFEB content likely rendering myocytes susceptible to cardiac injury.

  10. HIV-infected microglia mediate cathepsin B-induced neurotoxicity.

    Science.gov (United States)

    Zenón, Frances; Cantres-Rosario, Yisel; Adiga, Radhika; Gonzalez, Mariangeline; Rodriguez-Franco, Eillen; Langford, Dianne; Melendez, Loyda M

    2015-10-01

    HIV-1-infected mononuclear phagocytes release soluble factors that affect the homeostasis in tissue. HIV-1 can prompt metabolic encephalopathy with the addition of neuronal dysfunction and apoptosis. Recently, we reported that HIV-1 enhances the expression and secretion of bioactive cathepsin B in monocyte-derived macrophages, ultimately contributing to neuronal apoptosis. In this research, we asked if microglia respond to HIV infection similarly by modifying the expression, secretion, and neurotoxic potential of cathepsin B and determined the in vivo relevance of these findings. HIV-1ADA-infected human primary microglia and CHME-5 microglia cell line were assessed for expression and activity of cathepsin B, its inhibitors, cystatins B and C, and the neurotoxicity associated with these changes. Human primary neurons were exposed to supernatants from HIV-infected and uninfected microglia in the presence of cathepsin B inhibitors and apoptosis was assessed by TUNEL. Microglial expression of cathepsin B was validated in brain tissue from HIV encephalitis (HIVE) patients. HIV-infected microglia secreted significantly greater levels of cathepsin B, cystatin B, and cystatin C compared to uninfected cells. Increased apoptosis was observed in neurons exposed to supernatants from HIV-1 infected microglia at day 12 post-infection. The cathepsin B inhibitor CA-074 and cathepsin B antibody prevented neuronal apoptosis. Increased microglia-derived cathepsin B, cystatin B, and cystatin C and caspase-3+ neurons were detected in HIVE brains compared to controls. Our results suggest that HIV-1-induced cathepsin B production in microglia contributes to neuronal apoptosis and may be an important factor in neuronal death associated with HIVE.

  11. Unnatural amino acids increase activity and specificity of synthetic substrates for human and malarial cathepsin C.

    Science.gov (United States)

    Poreba, Marcin; Mihelic, Marko; Krai, Priscilla; Rajkovic, Jelena; Krezel, Artur; Pawelczak, Malgorzata; Klemba, Michael; Turk, Dusan; Turk, Boris; Latajka, Rafal; Drag, Marcin

    2014-04-01

    Mammalian cathepsin C is primarily responsible for the removal of N-terminal dipeptides and activation of several serine proteases in inflammatory or immune cells, while its malarial parasite ortholog dipeptidyl aminopeptidase 1 plays a crucial role in catabolizing the hemoglobin of its host erythrocyte. In this report, we describe the systematic substrate specificity analysis of three cathepsin C orthologs from Homo sapiens (human), Bos taurus (bovine) and Plasmodium falciparum (malaria parasite). Here, we present a new approach with a tailored fluorogenic substrate library designed and synthesized to probe the S1 and S2 pocket preferences of these enzymes with both natural and a broad range of unnatural amino acids. Our approach identified very efficiently hydrolyzed substrates containing unnatural amino acids, which resulted in the design of significantly better substrates than those previously known. Additionally, in this study significant differences in terms of the structures of optimal substrates for human and malarial orthologs are important from the therapeutic point of view. These data can be also used for the design of specific inhibitors or activity-based probes.

  12. Cathepsin L upregulation-induced EMT phenotype is associated with the acquisition of cisplatin or paclitaxel resistance in A549 cells.

    Science.gov (United States)

    Han, Mei-Ling; Zhao, Yi-Fan; Tan, Cai-Hong; Xiong, Ya-Jie; Wang, Wen-Juan; Wu, Feng; Fei, Yao; Wang, Long; Liang, Zhong-Qin

    2016-12-01

    Cathepsin L (CTSL), a lysosomal acid cysteine protease, is known to play important roles in tumor metastasis and chemotherapy resistance. In this study we investigated the molecular mechanisms underlying the regulation of chemoresistance by CTSL in human lung cancer cells. Human lung cancer A549 cells, A549/PTX (paclitaxel-resistant) cells and A549/DDP (cisplatin-resistant) cells were tested. The resistance to cisplatin or paclitaxel was detected using MTT and the colony-formation assays. Actin remodeling was observed with FITC-Phalloidin fluorescent staining or immunofluorescence. A wound-healing assay or Transwell assay was used to assess the migration or invasion ability. The expression of CTSL and epithelial and mesenchymal markers was analyzed with Western blotting and immunofluorescence. The expression of EMT-associated transcription factors was measured with Western blotting or q-PCR. BALB/c nude mice were implanted subcutaneously with A549 cells overexpressing CTSL, and the mice were administered paclitaxel (10, 15 mg/kg, ip) every 3 d for 5 times. Cisplatin or paclitaxel treatment (10-80 ng/mL) induced CTSL expression in A549 cells. CTSL levels were much higher in A549/PTX and A549/DDP cells than in A549 cells. Silencing of CTSL reversed the chemoresistance in A549/DDP and A549/TAX cells, whereas overexpression of CTSL attenuated the sensitivity of A549 cells to cisplatin or paclitaxel. Furthermore, A549/DDP and A549/TAX cells underwent morphological and cytoskeletal changes with increased cell invasion and migration abilities, accompanied by decreased expression of epithelial markers (E-cadherin and cytokeratin-18) and increased expression of mesenchymal markers (N-cadherin and vimentin), as well as upregulation of EMT-associated transcription factors Snail, Slug, ZEB1 and ZEB2. Silencing of CTSL reversed EMT in A549/DDP and A549/TAX cells; In contrast, overexpression of CTSL induced EMT in A549 cells. In xenograft nude mouse model, the mice implanted

  13. Human macrophage foam cells degrade atherosclerotic plaques through cathepsin K mediated processes

    DEFF Research Database (Denmark)

    Barascuk, Natasha; Skjøt-Arkil, Helene; Register, Thomas C

    2010-01-01

    BACKGROUND: Proteolytic degradation of Type I Collagen by proteases may play an important role in remodeling of atherosclerotic plaques, contributing to increased risk of plaque rupture.The aim of the current study was to investigate whether human macrophage foam cells degrade the extracellular......-I in areas of intimal hyperplasia and in shoulder regions of advanced plaques. Treatment of human monocytes with M-CSF or M-CSF+LDL generated macrophages and foam cells producing CTX-I when cultured on type I collagen enriched matrix. Circulating levels of CTX-I were not significantly different in women...... with aortic calcifications compared to those without. CONCLUSIONS: Human macrophage foam cells degrade the atherosclerotic plaques though cathepsin K mediated processes, resulting in increase in levels of CTX-I. Serum CTX-I was not elevated in women with aortic calcification, likely due to the contribution...

  14. First-Generation Antipsychotic Haloperidol Alters the Functionality of the Late Endosomal/Lysosomal Compartment in Vitro

    Directory of Open Access Journals (Sweden)

    Alberto Canfrán-Duque

    2016-03-01

    Full Text Available First- and second-generation antipsychotics (FGAs and SGAs, respectively, have the ability to inhibit cholesterol biosynthesis and also to interrupt the intracellular cholesterol trafficking, interfering with low-density lipoprotein (LDL-derived cholesterol egress from late endosomes/lysosomes. In the present work, we examined the effects of FGA haloperidol on the functionality of late endosomes/lysosomes in vitro. In HepG2 hepatocarcinoma cells incubated in the presence of 1,1′-dioctadecyl-3,3,3,3′-tetramethylindocarbocyanineperchlorate (DiI-LDL, treatment with haloperidol caused the enlargement of organelles positive for late endosome markers lysosome-associated membrane protein 2 (LAMP-2 and LBPA (lysobisphosphatidic acid, which also showed increased content of both free-cholesterol and DiI derived from LDL. This indicates the accumulation of LDL-lipids in the late endosomal/lysosomal compartment caused by haloperidol. In contrast, LDL traffic through early endosomes and the Golgi apparatus appeared to be unaffected by the antipsychotic as the distribution of both early endosome antigen 1 (EEA1 and coatomer subunit β (β-COP were not perturbed. Notably, treatment with haloperidol significantly increased the lysosomal pH and decreased the activities of lysosomal protease and β-d-galactosidase in a dose-dependent manner. We conclude that the alkalinization of the lysosomes’ internal milieu induced by haloperidol affects lysosomal functionality.

  15. First-Generation Antipsychotic Haloperidol Alters the Functionality of the Late Endosomal/Lysosomal Compartment in Vitro

    Science.gov (United States)

    Canfrán-Duque, Alberto; Barrio, Luis C.; Lerma, Milagros; de la Peña, Gema; Serna, Jorge; Pastor, Oscar; Lasunción, Miguel A.; Busto, Rebeca

    2016-01-01

    First- and second-generation antipsychotics (FGAs and SGAs, respectively), have the ability to inhibit cholesterol biosynthesis and also to interrupt the intracellular cholesterol trafficking, interfering with low-density lipoprotein (LDL)-derived cholesterol egress from late endosomes/lysosomes. In the present work, we examined the effects of FGA haloperidol on the functionality of late endosomes/lysosomes in vitro. In HepG2 hepatocarcinoma cells incubated in the presence of 1,1′-dioctadecyl-3,3,3,3′-tetramethylindocarbocyanineperchlorate (DiI)-LDL, treatment with haloperidol caused the enlargement of organelles positive for late endosome markers lysosome-associated membrane protein 2 (LAMP-2) and LBPA (lysobisphosphatidic acid), which also showed increased content of both free-cholesterol and DiI derived from LDL. This indicates the accumulation of LDL-lipids in the late endosomal/lysosomal compartment caused by haloperidol. In contrast, LDL traffic through early endosomes and the Golgi apparatus appeared to be unaffected by the antipsychotic as the distribution of both early endosome antigen 1 (EEA1) and coatomer subunit β (β-COP) were not perturbed. Notably, treatment with haloperidol significantly increased the lysosomal pH and decreased the activities of lysosomal protease and β-d-galactosidase in a dose-dependent manner. We conclude that the alkalinization of the lysosomes’ internal milieu induced by haloperidol affects lysosomal functionality. PMID:26999125

  16. SIRT1 regulates accumulation of oxidized LDL in HUVEC via the autophagy-lysosomal pathway.

    Science.gov (United States)

    Zhang, Yanlin; Sun, Juanjuan; Yu, Xiaoyan; Shi, Luyao; Du, Wenxiu; Hu, Lifang; Liu, Chunfeng; Cao, Yongjun

    2016-01-01

    Autophagy is involved in the degradation of oxidized low-density lipoprotein (ox-LDL) in human umbilical vein endothelial cells (HUVECs). Sirtuin1 (SIRT1), a new anti-atherosclerotic factor, can induce autophagy in cardiac myocytes. In the present study, we observed the effect of SIRT1 on the accumulation of ox-LDL in HUVECs, and elucidated whether its effect is relative with the autophagy-lysosomal pathway. The results showed that treatment with either SIRT1 siRNA or SIRT1 inhibitor nicotinamide (NAM) increased Dil-labelled-ox-LDL (Dil-ox-LDL) accumulation in HUVECs, and the SIRT1 inducer resveratrol (RSV) decreased it. Knockdown of autophagy-related protein 5 or inhibit the lysosomal degradation by chloroquine (CQ) decreased the effect of RSV. In HUVECs with ox-LDL, expression of LC3II and LC3 puncta was decreased by treatment with SIRT1 siRNA or NAM, but increased by RSV treatment; sequestosome 1 p62 expression showed the opposite effects. Moreover, Dil-ox-LDL combined with SIRT1 siRNA or NAM showed a much smaller degree of overlap of Lamp1 or Cathepsin D with Dil-ox-LDL than in cells with Dil-ox-LDL alone, and RSV treatment resulted in a greater degree of overlap. These results suggest that SIRT1 can decrease the accumulation of ox-LDL in HUVECs, and this effect is related to the autophagy-lysosomal pathway.

  17. Cathepsin L deficiency as molecular defect of furless: hyperproliferation of keratinocytes and pertubation of hair follicle cycling.

    Science.gov (United States)

    Roth, W; Deussing, J; Botchkarev, V A; Pauly-Evers, M; Saftig, P; Hafner, A; Schmidt, P; Schmahl, W; Scherer, J; Anton-Lamprecht, I; Von Figura, K; Paus, R; Peters, C

    2000-10-01

    Lysosomal cysteine proteinases of the papain family are involved in lysosomal bulk proteolysis, major histocompatibility complex class II mediated antigen presentation, prohormone processing, and extracellular matrix remodeling. Cathepsin L (CTSL) is a ubiquitously expressed major representative of the papain-like family of cysteine proteinases. To investigate CTSL in vivo functions, the gene was inactivated by gene targeting in embryonic stem cells. CTSL-deficient mice develop periodic hair loss and epidermal hyperplasia, acanthosis, and hyperkeratosis. The hair loss is due to alterations of hair follicle morphogenesis and cycling, dilatation of hair follicle canals, and disturbed club hair formation. Hyperproliferation of hair follicle epithelial cells and basal epidermal keratinocytes-both of ectodermal origin-are the primary characteristics underlying the mutant phenotype. Pathological inflammatory responses have been excluded as a putative cause of the skin and hair disorder. The phenotype of CTSL-deficient mice is reminiscent of the spontaneous mouse mutant furless (fs). Analyses of the ctsl gene of fs mice revealed a G149R mutation inactivating the proteinase activity. CTSL is the first lysosomal proteinase shown to be essential for epidermal homeostasis and regular hair follicle morphogenesis and cycling.

  18. Schistosome asparaginyl endopeptidase (legumain) is not essential for cathepsin B1 activation in vivo.

    Science.gov (United States)

    Krautz-Peterson, Greice; Skelly, Patrick J

    2008-05-01

    Schistosomes are parasitic platyhelminths that constitute an important public health problem. Adult parasites live in the vasculature of their vertebrate hosts where they consume blood. Ingested blood proteins are degraded by a proteolytic cascade. One of the best characterized schistosome proteases is cathepsin B1 (SmCB1 or Sm31). This protein is synthesized as a large 38 kDa precursor form which is proteolytically cleaved to yield a mature, active 31 kDa enzyme. A second schistosome protease--the asparaginyl endopeptidase SmAE (also known as Sm32, or schistosome legumain), has been proposed to proteolytically convert the 38 kDa precursor SmCB1 into its mature form. Recombinant activated SmAE has been shown to trans-process SmCB1 into the mature, catalytic form in vitro. In the present study, our aim was to test the hypothesis that in vivo SmAE likewise processes SmCB1 into its active form. To do this, expression of the SmAE gene was suppressed in adult Schistosoma mansoni using RNA interference (RNAi). The results of these experiments show that, even in the absence of detectable SmAE protein, SmCB1 is fully processed and active and support the assertion that SmAE is not essential to activate SmCB1 in vivo. The data indicate that our original hypothesis is incorrect and that SmAE is not pivotal in the in vivo conversion of cathepsin B1 into its mature, active form.

  19. The inhibitory effects of silver diamine fluorides on cysteine cathepsins.

    Science.gov (United States)

    Mei, May L; Ito, L; Cao, Y; Li, Q L; Chu, C H; Lo, Edward C M

    2014-03-01

    The expression of cysteine cathepsins in human carious dentine suggests that this enzyme contributes to the collagen degradation in caries progress. This study investigated whether silver diamine fluoride (SDF) inhibited the activity of cysteine cathepsins. Three commercial SDF solutions with concentrations at 38%, 30% and 12% were studied. Two fluoride solutions with the same fluoride ion (F(-)) concentrations as the 38% and 12% SDF solutions, and 2 silver solutions with the same silver ion (Ag(+)) concentrations as the 38% and 12% SDF solutions were prepared. Five samples of each experimental solution were used to study their inhibitory effect on two cathepsins (B and K) using cathepsin assay kits. Positive control contained assay buffer and cathepsins dilution was used to calculate the percentage inhibition (difference between the mean readings of the test solution and control solution divided by that of the control group). The percentage inhibition of 38%, 30% and 12% SDF on cathepsin B were 92.0%, 91.5% and 90.3%, respectively (pF(-) (pF(-) only (p<0.01). According to this study, SDF solution at all 3 tested concentrations significantly inhibited the activity of cathepsin B and K. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  20. Dipeptide-derived nitriles containing additional electrophilic sites: potentially irreversible inhibitors of cysteine proteases.

    Science.gov (United States)

    Löser, Reik; Gütschow, Michael

    2009-12-01

    Heterocyclic and open-chain dipeptide-derived nitriles have been synthesized, containing an additional electrophilic center enabling the subsequent covalent modification of the thioimidate nitrogen formed in situ at the active site of the enzyme. The inhibitory potential of these nitriles against the cysteine proteases papain and cathepsins L, S, and K was determined. The open-chain dipeptide nitriles 8 and 10 acted as moderate reversible inhibitors, but no evidence for an irreversible inhibition of these enzymes was discernable.

  1. SmCL3, a gastrodermal cysteine protease of the human blood fluke Schistosoma mansoni.

    Directory of Open Access Journals (Sweden)

    Jan Dvorák

    Full Text Available Blood flukes of the genus Schistosoma are platyhelminth parasites that infect 200 million people worldwide. Digestion of nutrients from the host bloodstream is essential for parasite development and reproduction. A network of proteolytic enzymes (proteases facilitates hydrolysis of host hemoglobin and serum proteins.We identified a new cathepsin L termed SmCL3 using PCR strategies based on S. mansoni EST sequence data. An ortholog is present in Schistosoma japonicum. SmCL3 was heterologously expressed as an active enzyme in the yeast, Pichia pastoris. Recombinant SmCL3 has a broad pH activity range against peptidyl substrates and is inhibited by Clan CA protease inhibitors. Consistent with a function in degrading host proteins, SmCL3 hydrolyzes serum albumin and hemoglobin, is localized to the adult gastrodermis, and is expressed mainly in those life stages infecting the mammalian host. The predominant form of SmCL3 in the parasite exists as a zymogen, which is unusual for proteases. This zymogen includes an unusually long prodomain with alpha helical secondary structure motifs. The striking specificity of SmCL3 for amino acids with large aromatic side chains (Trp and Tyr at the P2 substrate position, as determined with positional scanning-synthetic combinatorial library, is consistent with a molecular model that shows a large and deep S2 pocket. A sequence similarity network (SSN view clusters SmCL3 and other cathepsins L in accordance with previous large-scale phylogenetic analyses that identify six super kingdoms.SmCL3 is a gut-associated cathepsin L that may contribute to the network of proteases involved in degrading host blood proteins as nutrients. Furthermore, this enzyme exhibits some unusual sequence and biophysical features that may result in additional functions. The visualization of network inter-relationships among cathepsins L suggests that these enzymes are suitable 'marker sequences' for inclusion in future phylogenetic analyses.

  2. GNeosomes: Highly Lysosomotropic Nanoassemblies for Lysosomal Delivery.

    Science.gov (United States)

    Wexselblatt, Ezequiel; Esko, Jeffrey D; Tor, Yitzhak

    2015-01-01

    GNeosomes, lysosomotropic lipid vesicles decorated with guanidinoneomycin, can encapsulate and facilitate the cellular internalization and lysosomal delivery of cargo ranging from small molecules to high molecular weight proteins, in a process that is exclusively dependent on cell surface glycosaminoglycans. Their cellular uptake mechanism and co-localization with lysosomes, as well as the delivery, release, and activity of internalized cargo, are quantified. GNeosomes are proposed as a universal platform for lysosomal delivery with potential as a basic research tool and a therapeutic vehicle.

  3. Interactions between autophagic and endo-lysosomal markers in endothelial cells.

    Science.gov (United States)

    Oeste, Clara L; Seco, Esther; Patton, Wayne F; Boya, Patricia; Pérez-Sala, Dolores

    2013-05-01

    Autophagic and endo-lysosomal degradative pathways are essential for cell homeostasis. Availability of reliable tools to interrogate these pathways is critical to unveil their involvement in physiology and pathophysiology. Although several probes have been recently developed to monitor autophagic or lysosomal compartments, their specificity has not been validated through co-localization studies with well-known markers. Here, we evaluate the selectivity and interactions between one lysosomal (Lyso-ID) and one autophagosomal (Cyto-ID) probe under conditions modulating autophagy and/or endo-lysosomal function in live cells. The probe for acidic compartments Lyso-ID was fully localized inside vesicles positive for markers of late endosome-lysosomes, including Lamp1-GFP and GFP-CINCCKVL. Induction of autophagy by amino acid deprivation in bovine aortic endothelial cells caused an early and potent increase in the fluorescence of the proposed autophagy dye Cyto-ID. Cyto-ID-positive compartments extensively co-localized with the autophagosomal fluorescent reporter RFP-LC3, although the time and/or threshold for organelle detection was different for each probe. Interestingly, use of Cyto-ID in combination with Lysotracker Red or Lyso-ID allowed the observation of structures labeled with either one or both probes, the extent of co-localization increasing upon treatment with protease inhibitors. Inhibition of the endo-lysosomal pathway with chloroquine or U18666A resulted in the formation of large Cyto-ID and Lyso-ID-positive compartments. These results constitute the first assessment of the selectivity of Cyto-ID and Lyso-ID as probes for the autophagic and lysosomal pathways, respectively. Our observations show that these probes can be used in combination with protein-based markers for monitoring the interactions of both pathways in live cells.

  4. Synthesis and evaluation of new NIR-fluorescent probes for cathepsin B: ICT versus FRET as a turn-ON mode-of-action.

    Science.gov (United States)

    Kisin-Finfer, Einat; Ferber, Shiran; Blau, Rachel; Satchi-Fainaro, Ronit; Shabat, Doron

    2014-06-01

    Recent years have seen tremendous progress in the design and study of molecular imaging geared towards biological and biomedical applications. The expression or activity of specific enzymes including proteases can be monitored by cutting edge molecular imaging techniques. Cathepsin B plays key roles in tumor progression via controlled degradation of extracellular matrix. Consequently, this protease has been attracting significant attention in cancer research, and many imaging probes targeting its activity have been developed. Here, we describe the design, synthesis and evaluation of two novel near infrared (NIR) fluorescent probes for detection of cathepsin B activity with different turn-ON mechanisms. One probe is based on an ICT activation mechanism of a donor-two-acceptor π-electron dye system, while the other is based on the FRET mechanism obtained by a fluorescent dye and a quencher. The two probes exhibit significant fluorescent turn-ON response upon cleavage by cathepsin B. The NIR fluorescence of the ICT probe in its OFF state was significantly lower than that of the FRET-based probe. This effect results in a higher signal-to-noise ratio and consequently increased sensitivity and better image contrast.

  5. Identification of Chalcones as Fasciola hepatica Cathepsin L Inhibitors Using a Comprehensive Experimental and Computational Approach

    Science.gov (United States)

    Ferraro, Florencia; Merlino, Alicia; dell´Oca, Nicolás; Gil, Jorge; Tort, José F.; Gonzalez, Mercedes; Cerecetto, Hugo; Cabrera, Mauricio

    2016-01-01

    Background Increased reports of human infections have led fasciolosis, a widespread disease of cattle and sheep caused by the liver flukes Fasciola hepatica and Fasciola gigantica, to be considered an emerging zoonotic disease. Chemotherapy is the main control measure available, and triclabendazole is the preferred drug since is effective against both juvenile and mature parasites. However, resistance to triclabendazole has been reported in several countries urging the search of new chemical entities and target molecules to control fluke infections. Methodology/Principle Findings We searched a library of forty flavonoid derivatives for inhibitors of key stage specific Fasciola hepatica cysteine proteases (FhCL3 and FhCL1). Chalcones substituted with phenyl and naphtyl groups emerged as good cathepsin L inhibitors, interacting more frequently with two putative binding sites within the active site cleft of the enzymes. One of the compounds, C34, tightly bounds to juvenile specific FhCL3 with an IC50 of 5.6 μM. We demonstrated that C34 is a slow-reversible inhibitor that interacts with the Cys-His catalytic dyad and key S2 and S3 pocket residues, determinants of the substrate specificity of this family of cysteine proteases. Interestingly, C34 induces a reduction in NEJ ability to migrate through the gut wall and a loss of motility phenotype that leads to NEJ death within a week in vitro, while it is not cytotoxic to bovine cells. Conclusions/Significance Up to date there are no reports of in vitro screening for non-peptidic inhibitors of Fasciola hepatica cathepsins, while in general these are considered as the best strategy for in vivo inhibition. We have identified chalcones as novel inhibitors of the two main Cathepsins secreted by juvenile and adult liver flukes. Interestingly, one compound (C34) is highly active towards the juvenile enzyme reducing larval ability to penetrate the gut wall and decreasing NEJ´s viability in vitro. These findings open new avenues

  6. Identification of Chalcones as Fasciola hepatica Cathepsin L Inhibitors Using a Comprehensive Experimental and Computational Approach.

    Science.gov (United States)

    Ferraro, Florencia; Merlino, Alicia; Dell Oca, Nicolás; Gil, Jorge; Tort, José F; Gonzalez, Mercedes; Cerecetto, Hugo; Cabrera, Mauricio; Corvo, Ileana

    2016-07-01

    Increased reports of human infections have led fasciolosis, a widespread disease of cattle and sheep caused by the liver flukes Fasciola hepatica and Fasciola gigantica, to be considered an emerging zoonotic disease. Chemotherapy is the main control measure available, and triclabendazole is the preferred drug since is effective against both juvenile and mature parasites. However, resistance to triclabendazole has been reported in several countries urging the search of new chemical entities and target molecules to control fluke infections. We searched a library of forty flavonoid derivatives for inhibitors of key stage specific Fasciola hepatica cysteine proteases (FhCL3 and FhCL1). Chalcones substituted with phenyl and naphtyl groups emerged as good cathepsin L inhibitors, interacting more frequently with two putative binding sites within the active site cleft of the enzymes. One of the compounds, C34, tightly bounds to juvenile specific FhCL3 with an IC50 of 5.6 μM. We demonstrated that C34 is a slow-reversible inhibitor that interacts with the Cys-His catalytic dyad and key S2 and S3 pocket residues, determinants of the substrate specificity of this family of cysteine proteases. Interestingly, C34 induces a reduction in NEJ ability to migrate through the gut wall and a loss of motility phenotype that leads to NEJ death within a week in vitro, while it is not cytotoxic to bovine cells. Up to date there are no reports of in vitro screening for non-peptidic inhibitors of Fasciola hepatica cathepsins, while in general these are considered as the best strategy for in vivo inhibition. We have identified chalcones as novel inhibitors of the two main Cathepsins secreted by juvenile and adult liver flukes. Interestingly, one compound (C34) is highly active towards the juvenile enzyme reducing larval ability to penetrate the gut wall and decreasing NEJ´s viability in vitro. These findings open new avenues for the development of novel agents to control fluke infection and

  7. Identification of Chalcones as Fasciola hepatica Cathepsin L Inhibitors Using a Comprehensive Experimental and Computational Approach.

    Directory of Open Access Journals (Sweden)

    Florencia Ferraro

    2016-07-01

    Full Text Available Increased reports of human infections have led fasciolosis, a widespread disease of cattle and sheep caused by the liver flukes Fasciola hepatica and Fasciola gigantica, to be considered an emerging zoonotic disease. Chemotherapy is the main control measure available, and triclabendazole is the preferred drug since is effective against both juvenile and mature parasites. However, resistance to triclabendazole has been reported in several countries urging the search of new chemical entities and target molecules to control fluke infections.We searched a library of forty flavonoid derivatives for inhibitors of key stage specific Fasciola hepatica cysteine proteases (FhCL3 and FhCL1. Chalcones substituted with phenyl and naphtyl groups emerged as good cathepsin L inhibitors, interacting more frequently with two putative binding sites within the active site cleft of the enzymes. One of the compounds, C34, tightly bounds to juvenile specific FhCL3 with an IC50 of 5.6 μM. We demonstrated that C34 is a slow-reversible inhibitor that interacts with the Cys-His catalytic dyad and key S2 and S3 pocket residues, determinants of the substrate specificity of this family of cysteine proteases. Interestingly, C34 induces a reduction in NEJ ability to migrate through the gut wall and a loss of motility phenotype that leads to NEJ death within a week in vitro, while it is not cytotoxic to bovine cells.Up to date there are no reports of in vitro screening for non-peptidic inhibitors of Fasciola hepatica cathepsins, while in general these are considered as the best strategy for in vivo inhibition. We have identified chalcones as novel inhibitors of the two main Cathepsins secreted by juvenile and adult liver flukes. Interestingly, one compound (C34 is highly active towards the juvenile enzyme reducing larval ability to penetrate the gut wall and decreasing NEJ´s viability in vitro. These findings open new avenues for the development of novel agents to control

  8. Processing of Neutrophil α-Defensins Does Not Rely on Serine Proteases In Vivo

    DEFF Research Database (Denmark)

    Glenthøj, Andreas; Nickles, Katrin; Cowland, Jack;

    2015-01-01

    in promyelocytes: Neutrophil elastase (NE), cathepsin G (CG), and proteinase 3 (PR3), all of which are able to process recombinant proHNP into HNP in vitro. We investigated whether serine proteases are in fact responsible for processing of proHNP in human bone marrow cells and in human and murine myeloid cell...... lines. Subcellular fractionation of the human promyelocytic cell line PLB-985 demonstrated proHNP processing to commence in fractions containing endoplasmic reticulum. Processing of 35S-proHNP was insensitive to serine protease inhibitors. Simultaneous knockdown of NE, CG, and PR3 did not decrease pro...

  9. Identification of non-peptidic cysteine reactive fragments as inhibitors of cysteine protease rhodesain.

    Science.gov (United States)

    McShan, Danielle; Kathman, Stefan; Lowe, Brittiney; Xu, Ziyang; Zhan, Jennifer; Statsyuk, Alexander; Ogungbe, Ifedayo Victor

    2015-10-15

    Rhodesain, the major cathepsin L-like cysteine protease in the protozoan Trypanosoma brucei rhodesiense, the causative agent of African sleeping sickness, is a well-validated drug target. In this work, we used a fragment-based approach to identify inhibitors of this cysteine protease, and identified inhibitors of T. brucei. To discover inhibitors active against rhodesain and T. brucei, we screened a library of covalent fragments against rhodesain and conducted preliminary SAR studies. We envision that in vitro enzymatic assays will further expand the use of the covalent tethering method, a simple fragment-based drug discovery technique to discover covalent drug leads.

  10. Circulating cathepsin-S levels correlate with GFR decline and sTNFR1 and sTNFR2 levels in mice and humans

    Science.gov (United States)

    Steubl, Dominik; Kumar, Santhosh V.; Tato, Maia; Mulay, Shrikant R.; Larsson, Anders; Lind, Lars; Risérus, Ulf; Renders, Lutz; Heemann, Uwe; Carlsson, Axel C.; Ärnlöv, Johan; Anders, Hans-Joachim

    2017-01-01

    Cardiovascular complications determine morbidity/mortality in chronic kidney disease (CKD). We hypothesized that progressive CKD drives the release of cathepsin-S (Cat-S), a cysteine protease that promotes endothelial dysfunction and cardiovascular complications. Therefore, Cat-S, soluble tumor-necrosis-factor receptor (sTNFR) 1/2 and glomerular filtration rate (GFR) were measured in a CKD mouse model, a German CKD-cohort (MCKD, n = 421) and two Swedish community-based cohorts (ULSAM, n = 764 and PIVUS, n = 804). Association between Cat-S and sTNFR1/2/GFR was assessed using multivariable linear regression. In the mouse model, Cat-S and sTNFR1/2 concentrations were increased following the progressive decline of GFR, showing a strong correlation between Cat-S and GFR (r = −0.746, p < 0.001) and Cat-S and sTNFR1/sTNFR2 (r = 0.837/0.916, p < 0.001, respectively). In the human cohorts, an increase of one standard deviation of estimated GFR was associated with a decrease of 1.008 ng/ml (95%-confidence interval (95%-CI) −1.576–(−0.439), p < 0.001) in Cat-S levels in MCKD; in ULSAM and PIVUS, results were similar. In all three cohorts, Cat-S and sTNFR1/sTNFR2 levels were associated in multivariable linear regression (p < 0.001). In conclusion, as GFR declines Cat-S and markers of inflammation-related endothelial dysfunction increase. The present data indicating that Cat-S activity increases with CKD progression suggest that Cat-S might be a therapeutic target to prevent cardiovascular complications in CKD. PMID:28240259

  11. Identification of semicarbazones, thiosemicarbazones and triazine nitriles as inhibitors of Leishmania mexicana cysteine protease CPB.

    Directory of Open Access Journals (Sweden)

    Jörg Schröder

    Full Text Available Cysteine proteases of the papain superfamily are present in nearly all eukaryotes. They play pivotal roles in the biology of parasites and inhibition of cysteine proteases is emerging as an important strategy to combat parasitic diseases such as sleeping sickness, Chagas' disease and leishmaniasis. Homology modeling of the mature Leishmania mexicana cysteine protease CPB2.8 suggested that it differs significantly from bovine cathepsin B and thus could be a good drug target. High throughput screening of a compound library against this enzyme and bovine cathepsin B in a counter assay identified four novel inhibitors, containing the warhead-types semicarbazone, thiosemicarbazone and triazine nitrile, that can be used as leads for antiparasite drug design. Covalent docking experiments confirmed the SARs of these lead compounds in an effort to understand the structural elements required for specific inhibition of CPB2.8. This study has provided starting points for the design of selective and highly potent inhibitors of L. mexicana cysteine protease CPB that may also have useful efficacy against other important cysteine proteases.

  12. Identification of semicarbazones, thiosemicarbazones and triazine nitriles as inhibitors of Leishmania mexicana cysteine protease CPB.

    Science.gov (United States)

    Schröder, Jörg; Noack, Sandra; Marhöfer, Richard J; Mottram, Jeremy C; Coombs, Graham H; Selzer, Paul M

    2013-01-01

    Cysteine proteases of the papain superfamily are present in nearly all eukaryotes. They play pivotal roles in the biology of parasites and inhibition of cysteine proteases is emerging as an important strategy to combat parasitic diseases such as sleeping sickness, Chagas' disease and leishmaniasis. Homology modeling of the mature Leishmania mexicana cysteine protease CPB2.8 suggested that it differs significantly from bovine cathepsin B and thus could be a good drug target. High throughput screening of a compound library against this enzyme and bovine cathepsin B in a counter assay identified four novel inhibitors, containing the warhead-types semicarbazone, thiosemicarbazone and triazine nitrile, that can be used as leads for antiparasite drug design. Covalent docking experiments confirmed the SARs of these lead compounds in an effort to understand the structural elements required for specific inhibition of CPB2.8. This study has provided starting points for the design of selective and highly potent inhibitors of L. mexicana cysteine protease CPB that may also have useful efficacy against other important cysteine proteases.

  13. C1A cysteine protease-cystatin interactions in leaf senescence.

    Science.gov (United States)

    Díaz-Mendoza, Mercedes; Velasco-Arroyo, Blanca; González-Melendi, Pablo; Martínez, Manuel; Díaz, Isabel

    2014-07-01

    Senescence-associated proteolysis in plants is a crucial process to relocalize nutrients from leaves to growing or storage tissues. The massive net degradation of proteins involves broad metabolic networks, different subcellular compartments, and several types of proteases and regulators. C1A cysteine proteases, grouped as cathepsin L-, B-, H-, and F-like according to their gene structures and phylogenetic relationships, are the most abundant enzymes responsible for the proteolytic activity during leaf senescence. Besides, cystatins as specific modulators of C1A peptidase activities exert a complex regulatory role in this physiological process. This overview article covers the most recent information on C1A proteases in leaf senescence in different plant species. Particularly, it is focussed on barley, as the unique species where the whole gene family members of C1A cysteine proteases and cystatins have been analysed.

  14. Concanavalin A/IFN-gamma triggers autophagy-related necrotic hepatocyte death through IRGM1-mediated lysosomal membrane disruption.

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    Chih-Peng Chang

    Full Text Available Interferon-gamma (IFN-γ, a potent Th1 cytokine with multiple biological functions, can induce autophagy to enhance the clearance of the invading microorganism or cause cell death. We have reported that Concanavalin A (Con A can cause autophagic cell death in hepatocytes and induce both T cell-dependent and -independent acute hepatitis in immunocompetent and immunodeficient mice, respectively. Although IFN-γ is known to enhance liver injury in Con A-induced hepatitis, its role in autophagy-related hepatocyte death is not clear. In this study we report that IFN-γ can enhance Con A-induced autophagic flux and cell death in hepatoma cell lines. A necrotic cell death with increased lysosomal membrane permeabilization (LMP is observed in Con A-treated hepatoma cells in the presence of IFN-γ. Cathepsin B and L were released from lysosomes to cause cell death. Furthermore, IFN-γ induces immunity related GTPase family M member 1(IRGM1 translocation to lysosomes and prolongs its activity in Con A-treated hepatoma cells. Knockdown of IRGM1 inhibits the IFN-γ/Con A-induced LMP change and cell death. Furthermore, IFN-γ(-/- mice are resistant to Con A-induced autophagy-associated necrotic hepatocyte death. We conclude that IFN-γ enhances Con A-induced autophagic flux and causes an IRGM1-dependent lysosome-mediated necrotic cell death in hepatocytes.

  15. Molecular and functional characterisation of a stress responsive cysteine protease, EhCP6 from Entamoeba histolytica.

    Science.gov (United States)

    Ghosh, Anupama; Raha, Sanghamitra

    2015-05-01

    Entamoeba histolytica cysteine protease 6 (EhCP6) is a stress responsive cysteine protease that is upregulated in response to heat shock and during pathogen invasion of the host tissue. In the present study an attempt has been made to express and purify recombinant EhCP6 in order to gain insights into its biochemical properties. The recombinant and refolded protein has been shown to undergo autoproteolysis in the presence of DTT and SDS to give rise to ∼25kDa mature form. The mature form of the protein was found to exhibit a protease activity that is sensitive to E-64, a specific cysteine protease inhibitor. In silico homology modelling of EhCP6 revealed that the protein exhibits conservation of almost all the major structural features of cathepsin-L like cysteine proteases. Further in vivo studies are needed to decipher the function of the protein in response to different stressed conditions.

  16. A molecular mechanism to regulate lysosome motility for lysosome positioning and tubulation.

    Science.gov (United States)

    Li, Xinran; Rydzewski, Nicholas; Hider, Ahmad; Zhang, Xiaoli; Yang, Junsheng; Wang, Wuyang; Gao, Qiong; Cheng, Xiping; Xu, Haoxing

    2016-04-01

    To mediate the degradation of biomacromolecules, lysosomes must traffic towards cargo-carrying vesicles for subsequent membrane fusion or fission. Mutations of the lysosomal Ca(2+) channel TRPML1 cause lysosomal storage disease (LSD) characterized by disordered lysosomal membrane trafficking in cells. Here we show that TRPML1 activity is required to promote Ca(2+)-dependent centripetal movement of lysosomes towards the perinuclear region (where autophagosomes accumulate) following autophagy induction. ALG-2, an EF-hand-containing protein, serves as a lysosomal Ca(2+) sensor that associates physically with the minus-end-directed dynactin-dynein motor, while PtdIns(3,5)P(2), a lysosome-localized phosphoinositide, acts upstream of TRPML1. Furthermore, the PtdIns(3,5)P(2)-TRPML1-ALG-2-dynein signalling is necessary for lysosome tubulation and reformation. In contrast, the TRPML1 pathway is not required for the perinuclear accumulation of lysosomes observed in many LSDs, which is instead likely to be caused by secondary cholesterol accumulation that constitutively activates Rab7-RILP-dependent retrograde transport. Ca(2+) release from lysosomes thus provides an on-demand mechanism regulating lysosome motility, positioning and tubulation.

  17. Up-regulation of lysosomal TRPML1 channels is essential for lysosomal adaptation to nutrient starvation.

    Science.gov (United States)

    Wang, Wuyang; Gao, Qiong; Yang, Meimei; Zhang, Xiaoli; Yu, Lu; Lawas, Maria; Li, Xinran; Bryant-Genevier, Marthe; Southall, Noel T; Marugan, Juan; Ferrer, Marc; Xu, Haoxing

    2015-03-17

    Upon nutrient starvation, autophagy digests unwanted cellular components to generate catabolites that are required for housekeeping biosynthesis processes. A complete execution of autophagy demands an enhancement in lysosome function and biogenesis to match the increase in autophagosome formation. Here, we report that mucolipin-1 (also known as TRPML1 or ML1), a Ca(2+) channel in the lysosome that regulates many aspects of lysosomal trafficking, plays a central role in this quality-control process. By using Ca(2+) imaging and whole-lysosome patch clamping, lysosomal Ca(2+) release and ML1 currents were detected within hours of nutrient starvation and were potently up-regulated. In contrast, lysosomal Na(+)-selective currents were not up-regulated. Inhibition of mammalian target of rapamycin (mTOR) or activation of transcription factor EB (TFEB) mimicked a starvation effect in fed cells. The starvation effect also included an increase in lysosomal proteostasis and enhanced clearance of lysosomal storage, including cholesterol accumulation in Niemann-Pick disease type C (NPC) cells. However, this effect was not observed when ML1 was pharmacologically inhibited or genetically deleted. Furthermore, overexpression of ML1 mimicked the starvation effect. Hence, lysosomal adaptation to environmental cues such as nutrient levels requires mTOR/TFEB-dependent, lysosome-to-nucleus regulation of lysosomal ML1 channels and Ca(2+) signaling.

  18. BK Channels Alleviate Lysosomal Storage Diseases by Providing Positive Feedback Regulation of Lysosomal Ca2+ Release.

    Science.gov (United States)

    Cao, Qi; Zhong, Xi Zoë; Zou, Yuanjie; Zhang, Zhu; Toro, Ligia; Dong, Xian-Ping

    2015-05-26

    Promoting lysosomal trafficking represents a promising therapeutic approach for lysosome storage diseases. Efficient Ca(2+) mobilization from lysosomes is important for lysosomal trafficking. Ca(2+) release from lysosomes could generate a negative potential in the lumen to disturb subsequent Ca(2+) release in the absence of counter ion flux. Here we report that lysosomes express big-conductance Ca(2+)-activated potassium (BK) channels that form physical and functional coupling with the lysosomal Ca(2+) release channel, TRPML1. Ca(2+) release via TRPML1 causes BK activation, which in turn facilitates further lysosomal Ca(2+) release and membrane trafficking. Importantly, BK overexpression rescues the impaired TRPML1-mediated Ca(2+) release and abnormal lysosomal storage in cells from Niemann-Pick C1 patients. Therefore, we have identified a lysosomal K(+) channel that provides a positive feedback mechanism to facilitate TRPML1-mediated Ca(2+) release and membrane trafficking. Our findings suggest that upregulating BK may be a potential therapeutic strategy for certain lysosomal storage diseases and common neurodegenerative disorders.

  19. Sensitivity to lysosome-dependent cell death is directly regulated by lysosomal cholesterol content.

    Directory of Open Access Journals (Sweden)

    Hanna Appelqvist

    Full Text Available Alterations in lipid homeostasis are implicated in several neurodegenerative diseases, although the mechanisms responsible are poorly understood. We evaluated the impact of cholesterol accumulation, induced by U18666A, quinacrine or mutations in the cholesterol transporting Niemann-Pick disease type C1 (NPC1 protein, on lysosomal stability and sensitivity to lysosome-mediated cell death. We found that neurons with lysosomal cholesterol accumulation were protected from oxidative stress-induced apoptosis. In addition, human fibroblasts with cholesterol-loaded lysosomes showed higher lysosomal membrane stability than controls. Previous studies have shown that cholesterol accumulation is accompanied by the storage of lipids such as sphingomyelin, glycosphingolipids and sphingosine and an up regulation of lysosomal associated membrane protein-2 (LAMP-2, which may also influence lysosomal stability. However, in this study the use of myriocin and LAMP deficient fibroblasts excluded these factors as responsible for the rescuing effect and instead suggested that primarily lysosomal cholesterol content determineD the cellular sensitivity to toxic insults. Further strengthening this concept, depletion of cholesterol using methyl-β-cyclodextrin or 25-hydroxycholesterol decreased the stability of lysosomes and cells became more prone to undergo apoptosis. In conclusion, cholesterol content regulated lysosomal membrane permeabilization and thereby influenced cell death sensitivity. Our data suggests that lysosomal cholesterol modulation might be used as a therapeutic strategy for conditions associated with accelerated or repressed apoptosis.

  20. The intramembrane protease SPPL2A is critical for tooth enamel formation

    NARCIS (Netherlands)

    Bronckers, A.L.J.J.; Gueneli, N.; Lüllmann-Rauch, R.; Schneppenheim, J.; Moraru, A.P.; Himmerkus, N.; Bervoets, T.J.; Fluhrer, R.; Everts, V.; Saftig, P.; Schröder, B.

    2013-01-01

    Intramembrane proteases are critically involved in signal transduction and membrane protein turnover. Signal-peptide-peptidase-like 2a (SPPL2A), a presenilin-homologue residing in lysosomes/late endosomes, cleaves type II-oriented transmembrane proteins. We recently identified SPPL2A as the enzyme c

  1. Drynaria total flavonoids decrease cathepsin K expression in ovariectomized rats.

    Science.gov (United States)

    Shi, X L; Li, C W; Wan, Q Z; Li, A Q; Wang, H; Liu, K

    2014-06-09

    This study investigated the effects of Drynaria total flavonoids on cathepsin K serum concentrations and gene expression, biomechanics and bone mineral density (BMD) of the tibial shaft in ovariectomized rat models of osteoporosis, and mechanism in the prevention and cure of osteoporosis. Seventy-two female Sprague-Dawley rats were divided into six groups. The rats in each group were subjected to gastric lavage after the model was established. The tibial shaft of the right hindlimb was obtained to measure the BMD. Serum cathepsin K concentrations were determined. The cathepsin K mRNA expression was also determined using fluorescent quantitative polymerase chain reaction. The three-point bending method was performed to measure the maximum bending load of the tibial shaft. The total flavonoid and normal groups had significant differences in serum cathepsin K concentrations compared with that in the estrogen group (Ptotal flavonoid and sham-operated groups also showed significant differences in cathepsin K mRNA expression compared with that in the normal group (Ptotal flavonoid group was significantly different from that in the estrogen group (Ptotal flavonoid group elicited a better effect on BMD than that by the medium- and low-dose groups (Ptotal flavonoids inhibited the serum cathepsin K concentration and increased the maximum bending load of the tibial shaft in ovariectomized rats.

  2. Alterations in cathepsin L expression in lung cancers.

    Science.gov (United States)

    Okudela, Koji; Mitsui, Hideaki; Woo, Tetsukan; Arai, Hiromasa; Suzuki, Takehisa; Matsumura, Mai; Kojima, Yoko; Umeda, Shigeaki; Tateishi, Yoko; Masuda, Munetaka; Ohashi, Kenichi

    2016-07-01

    We herein investigated the potential role of cathepsin L in lung carcinogenesis. Lung cancer cell lines and surgically resected tumors were examined for the expression of the cathepsin L protein and copy number alterations in its gene locus. Cathepsin L was stably expressed in bronchiolar epithelial cells. Neoplastic cells expressed cathepsin L at various levels, whereas its expression was completely lost in most of the lung cancer cell lines (63.6%, 7/11) examined. Furthermore, expression levels were lower in a large fraction of lung tumors (69.5%, 139/200) than in bronchiolar epithelia. The expression of cathepsin L was lost in some tumors (16.0%, 32/200). In adenocarcinomas, expression levels were significantly lower in high-grade tumors than in low-grade tumors (one-way ANOVA, P L protein expression levels and the copy number of its gene locus (Spearman's rank-order correlation, P = 0.3096). Collectively, these results suggest that the down-regulated expression of cathepsin L, which is caused by an undefined mechanism other than copy number alterations, is involved in the progression of lung adenocarcinomas.

  3. Cysteine protease activation and apoptosis in Murine norovirus infection

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    Ettayebi Khalil

    2009-09-01

    Full Text Available Abstract Background Noroviruses are the leading cause of viral gastroenteritis. Because a suitable in vitro culture system for the human virus has yet to be developed, many basic details of the infection process are unknown. Murine norovirus (MNV serves as a model system for the study of norovirus infection. Recently it was shown that infection of RAW 264.7 cells involved a novel apoptotic pathway involving survivin. Results Using a different set of approaches, the up-regulation of caspases, DNA condensation/fragmentation, and membrane blebbing, all of which are markers of apoptosis, were confirmed. Live cell imaging and activity-based protein profiling showed that activation of caspase-like proteases occurred within two hours of infection, followed by morphological changes to the cells. MNV infection in the presence of caspase inhibitors proceeded via a distinct pathway of rapid cellular necrosis and reduced viral production. Affinity purification of activity-based protein profiling targets and identification by peptide mass fingerprinting showed that the cysteine protease cathepsin B was activated early in infection, establishing this protein as an upstream activator of the intrinsic apoptotic pathway. Conclusion This work adds cathepsin B to the noncanonical programmed cell death induced by MNV, and provides data suggesting that the virus may induce apoptosis to expand the window of time for viral replication. This work also highlights the significant power of activity-based protein profiling in the study of viral pathogenesis.

  4. Processing and targeting of the thiol protease, aleurain

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, J.C.

    1989-01-01

    We have identified a cDNA clone from barley aleurone mRNA that encodes a protein with unusual homologies: the C-terminal portion, about 270 amino acids, is 65% identical to the mammalian thiol protease, cathepsin H. This degree of sequence conservation indicates that the enzyme must have some specific function in both plants and mammals that cannot tolerate further divergence. The N-terminal 1/3 of the protein, about 140 amino acids, has no detectable homologies to other known protein sequences; its function is unknown. In aleurone tissue, the mRNA level is increased by gibberellic acid and decreased by abscisic acid, but is expressed apparently constitutively at high levels in leaf and root tissues. The amino acid sequence and cathepsin H homology suggest that the protein will be both secreted into the endoplasmic reticulum and glycosylated. Using our cDNA clone in a bacterial expression system, we have made a fusion protein containing the protease domain of aleurain, and have used it to raise specific antisera in rabbits. These antibodies identify a 32 kd protein in extracts of aleurone layers that is induced with GA treatment but not secreted; a similarly sized protein is specifically identified in extracts of leaf tissue. Experiments are underway to characterize the pattern of expression in different tissues, to identify the subcellular locations of the protein, to characterize processing of the precursor to the 32 kd mature form, and to purify the enzyme from barley. 2 figs.

  5. Autophagy and cathepsin L are involved in the antinociceptive effect of DMBC in a mouse acetic acid-writhing model

    Institute of Scientific and Technical Information of China (English)

    Wei-wei GU; Gui-zhen AO; Yong-ming ZHU; Shi-chang SUN; Qiang ZHOU; Jia-hong FAN; Katunuma NOBUHIKO

    2013-01-01

    Aim:2-(3',5'-Dimethoxybenzylidene) cyclopentanone (DMBC) is a novel synthetic compound with antinociceptive activities.The aim of this study was to investigate the roles of the autophagic-lysosomal pathway in the antinociceptive effect of DMBC in a mouse acetic acid-writhing model.Methods:Mouse acetic acid-writhing test and hotplate test were used to assess the antinociceptive effects of DMBC,3-MA (autophagy inhibitor) and Clik148 (cathepsin L inhibitor).The drugs were administered peripherally (ip) or centrally (icv).Results:Peripheral administration of 3-MA (7.5-30 mg/kg) or Clik148 (10-80 mg/kg) produced potent antinociceptive effect in acetic acid-writhing test.Central administration of 3-MA or Clik148 (12.5-50 nmol/L) produced comparable antinociceptive effect in acetic acid-writhing test.Peripheral administration of DMBC (25-50 mg/kg) produced potent antinociceptive effects in both acetic acidwrithing and hotplate tests.Furthermore,the antinociceptive effect produced by peripheral administration of DMBC (50 mg/kg) in acetic acid-writhing test was antagonized by low doses of 3-MA (3.75 mg/kg) or Clik148 (20 mg/kg) peripherally administered,but was not affected by 3-MA or Clik148 (25 nmol/L) centrally administered.Conclusion:Activation of central autophagy and cathepsin L is involved in nociception in mice,whereas peripheral autophagy and cathepsin L contributes,at least in part,to the antinociceptive effect of DMBC in mice.

  6. THE PROGNOSIS SIGNIFICANCE OF CATHEPSIN-D EXPRESSION IN THE DIFFERENT LOCATIONS IN AXILLARY NODES NEGATIVE CARCINOMA

    Institute of Scientific and Technical Information of China (English)

    NIU; Yun

    2001-01-01

    [1]Garcia M, Platet N, Liaudet Estradiol, et al. Biological and clinical significance of cathepsin D in breast cancer metastasis [J]. Stem Cells 1996; 14:642.[2]Johnson MD, Torri JA, Lippman ME, et al. The role of cathepsin D in the invasiveness of human breast cancer cells [J]. Cancer Res 1993; 53: 873.[3]Duffy MJ. Proteases as prognostic markers in cancer [J]. Clin Cancer Res 1996; 2:613.[4]Westley BR, May FE. Cathepsin D and breast cancer [J]. Eur J Cancer 1996; 32A:7.[5]Riley LB, Lange MK, Browne RJ, et al. Analysis of cathepsin D in human breast cancer: usefulness of the processed 31 kDa active form of the enzyme as a prognostic indicator in node-negative and node-positive patients [J]. Breast Cancer Res Treat 2000; 60:173.[6]Fu XL. Histopathologic diagnosis. Chinese Common Malignant Tumor Diagnosis and Treatment Rule. Breast Carcinoma Volume [M]. 2nd ed. Beijing: Beijing Medical University and Chinese Xiehe Medical University Union Publisher, 1999; 23.[7]Yang SQ. Health Statistics [M]. 3rd ed. Beijing: People Health Publisher, 1998; 131.[8]Bittl A, Nap M, Jager W, et al. Immuno-histochemical detection of P-glycoprotein on frozen and paraffin-embedded tissue sections of normal and malignant tissues [J]. Anticancer Res 1995; 15:1007.[9]Isola J, Weitz S, Visakorpi T, et al. Cathepsin D expression detected by immunohistochemistry has independent prognostic value in axillary node-negative breast cancer [J]. J Clin Oncol 1993; 11:36.[10]Castiglioni T, Merino MJ, Elsner B, et al. Immunohistochemical analysis of cathepsins D, B, and L in human breast cancer [J]. Hum Pathol 1994; 25:857.[11]Montcourrier P, Mangeat PH, Valembois C, et al. Characterization of very acidic phagosomes in breast cancer cells and their association with invasion [J]. J Cell Sci 1994; 107:238l.[12]Foekens JA, Look MP, Bolt de Vries J, et al. Cathepsin-D in primary breast cancer: prognostic evaluation involving 2810 patients [J]. Br J Cancer 1999

  7. Cathepsin K Contributes to Cavitation and Collagen Turnover in Pulmonary Tuberculosis.

    Science.gov (United States)

    Kubler, Andre; Larsson, Christer; Luna, Brian; Andrade, Bruno B; Amaral, Eduardo P; Urbanowski, Michael; Orandle, Marlene; Bock, Kevin; Ammerman, Nicole C; Cheung, Laurene S; Winglee, Kathryn; Halushka, Marc; Park, Jin Kyun; Sher, Alan; Friedland, Jon S; Elkington, Paul T; Bishai, William R

    2016-02-15

    Cavitation in tuberculosis enables highly efficient person-to-person aerosol transmission. We performed transcriptomics in the rabbit cavitary tuberculosis model. Among 17 318 transcripts, we identified 22 upregulated proteases. Five type I collagenases were overrepresented: cathepsin K (CTSK), mast cell chymase-1 (CMA1), matrix metalloproteinase 1 (MMP-1), MMP-13, and MMP-14. Studies of collagen turnover markers, specifically, collagen type I C-terminal propeptide (CICP), urinary deoxypyridinoline (DPD), and urinary helical peptide, revealed that cavitation in tuberculosis leads to both type I collagen destruction and synthesis and that proteases other than MMP-1, MMP-13, and MMP-14 are involved, suggesting a key role for CTSK. We confirmed the importance of CTSK upregulation in human lung specimens, using immunohistochemical analysis, which revealed perigranulomatous staining for CTSK, and we showed that CTSK levels were increased in the serum of patients with tuberculosis, compared with those in controls (3.3 vs 0.3 ng/mL; P = .005). © The Author 2015. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  8. Endosome-lysosomes and neurodegeneration.

    Science.gov (United States)

    Mayer, R J; Tipler, C; Laszlo, L; Arnold, J; Lowe, J; Landon, M

    1994-01-01

    A number of the major human and animal neurodegenerative diseases, such as Alzheimer's disease and sheep scrapie, are characterised by deposits of amyloid, arising through incomplete breakdown of membrane proteins. Although our knowledge concerning these diseases is increasing, they remain largely untreatable. Recently, attention has focussed on the mechanisms of production of different types of amyloid and the likely involvement within cells of acid compartments called endosome-lysosomes. These organelles may be 'bioreactor' sites for the unfolding and partial degradation of membrane proteins to generate the amyloid materials. These subsequently become expelled from the cell, or are released from dead cells, and accumulate as pathological entities. Common features of the disease processes give new direction to therapeutic intervention.

  9. Expression of Cathepsin K in Skull Base Chordoma.

    Science.gov (United States)

    Tian, Kaibing; Ma, Junpeng; Wang, Liang; Wang, Ke; Li, Da; Hao, Shuyu; Yang, Yang; Du, Jiang; Jia, Guijun; Zhang, Liwei; Wu, Zhen; Zhang, Junting

    2017-05-01

    The aim of this study was to explore the association between cathepsin K and the clinical characteristics of skull base chordoma (SBC). This study included 58 paraffin-embedded samples and 85 frozen samples of 94 patients. All clinical data corresponding to these patients were available. Immunohistochemical staining and quantitative real-time polymerase chain reaction were performed. Positive rate of immunohistochemical staining slices and delta cycle threshold value of quantitative real-time polymerase chain reaction represented the cathepsin K expression level in protein and gene level separately. In protein level, expression level (EL) of invasive tumors was increased compared with noninvasive tumors (P = 0.006), EL of tumors with dura erosion was increased compared with tumors without dura erosion (P = 0.001). Tumors with septa exhibited increased EL compared with tumors without septa (P = 0.001). Tumors with lobulation exhibited increased EL compared with tumors without lobulation (P = 0.000). Higher EL of cathepsin K was associated with reduced progression-free survival (PFS) (P = 0.015). In gene level, tumors with septa showed higher EL than tumors without septa (P = 0.015), and tumors with lobulation showed higher EL than tumors without lobulation (P = 0.049). Cathepsin K EL was an independent risk factor for reduced PFS, and an increased level of cathepsin K in SBC was associated with reduced PFS (P = 0.042). Increased cathepsin K expression in SBC was associated with tumor invasion and reduced PFS. The cathepsin K level in SBC also was associated with tumor stage, tumor lobulation, and septa. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Expression of a barley cystatin gene in maize enhances resistance against phytophagous mites by altering their cysteine-proteases.

    Science.gov (United States)

    Carrillo, Laura; Martinez, Manuel; Ramessar, Koreen; Cambra, Inés; Castañera, Pedro; Ortego, Felix; Díaz, Isabel

    2011-01-01

    Phytocystatins are inhibitors of cysteine-proteases from plants putatively involved in plant defence based on their capability of inhibit heterologous enzymes. We have previously characterised the whole cystatin gene family members from barley (HvCPI-1 to HvCPI-13). The aim of this study was to assess the effects of barley cystatins on two phytophagous spider mites, Tetranychus urticae and Brevipalpus chilensis. The determination of proteolytic activity profile in both mite species showed the presence of the cysteine-proteases, putative targets of cystatins, among other enzymatic activities. All barley cystatins, except HvCPI-1 and HvCPI-7, inhibited in vitro mite cathepsin L- and/or cathepsin B-like activities, HvCPI-6 being the strongest inhibitor for both mite species. Transgenic maize plants expressing HvCPI-6 protein were generated and the functional integrity of the cystatin transgene was confirmed by in vitro inhibitory effect observed against T. urticae and B. chilensis protein extracts. Feeding experiments impaired on transgenic lines performed with T. urticae impaired mite development and reproductive performance. Besides, a significant reduction of cathepsin L-like and/or cathepsin B-like activities was observed when the spider mite fed on maize plants expressing HvCPI-6 cystatin. These findings reveal the potential of barley cystatins as acaricide proteins to protect plants against two important mite pests.

  11. Lysosomal-associated transmembrane protein 5 (LAPTM5 is a molecular partner of CD1e.

    Directory of Open Access Journals (Sweden)

    Catherine Angénieux

    Full Text Available The CD1e protein participates in the presentation of lipid antigens in dendritic cells. Its transmembrane precursor is transported to lysosomes where it is cleaved into an active soluble form. In the presence of bafilomycin, which inhibits vacuolar ATPase and consequently the acidification of endosomal compartments, CD1e associates with a 27 kD protein. In this work, we identified this molecular partner as LAPTM5. The latter protein and CD1e colocalize in trans-Golgi and late endosomal compartments. The quantity of LAPTM5/CD1e complexes increases when the cells are treated with bafilomycin, probably due to the protection of LAPTM5 from lysosomal proteases. Moreover, we could demonstrate that LAPTM5/CD1e association occurs under physiological conditions. Although LAPTM5 was previously shown to act as a platform recruiting ubiquitin ligases and facilitating the transport of receptors to lysosomes, we found no evidence that LATPM5 controls either CD1e ubiquitination or the generation of soluble lysosomal CD1e proteins. Notwithstanding these last observations, the interaction of LAPTM5 with CD1e and their colocalization in antigen processing compartments both suggest that LAPTM5 might influence the role of CD1e in the presentation of lipid antigens.

  12. Cathepsin G-regulated release of formyl peptide receptor agonists modulate neutrophil effector functions.

    Science.gov (United States)

    Woloszynek, Josh C; Hu, Ying; Pham, Christine T N

    2012-10-05

    Neutrophil serine proteases play an important role in inflammation by modulating neutrophil effector functions. We have previously shown that neutrophils deficient in the serine proteases cathepsin G and neutrophil elastase (CG/NE neutrophils) exhibit severe defects in chemokine CXCL2 release and reactive oxygen species (ROS) production when activated on immobilized immune complex. Exogenously added active CG rescues these defects, but the mechanism remains undefined. Using a protease-based proteomic approach, we found that, in vitro, the addition of exogenous CG to immune complex-stimulated CG/NE neutrophils led to a decrease in the level of cell-associated annexin A1 (AnxA1) and cathelin-related antimicrobial peptide (CRAMP), both known inflammatory mediators. We further confirmed that, in vivo, CG was required for the extracellular release of AnxA1 and CRAMP in a subcutaneous air pouch model. In vitro, CG efficiently cleaved AnxA1, releasing the active N-terminal peptide Ac2-26, and processed CRAMP in limited fashion. Ac2-26 and CRAMP peptides enhanced the release of CXCL2 by CG/NE neutrophils in a dose-dependent manner via formyl peptide receptor (FPR) stimulation. Blockade of FPRs by an antagonist, Boc2 (t-Boc-Phe-d-Leu-Phe-d-Leu-Phe), abrogates CXCL2 release, whereas addition of FPR agonists, fMLF and F2L, relieves Boc2 inhibition. Furthermore, the addition of active CG, but not inactive CG, also relieves Boc2 inhibition. These findings suggest that CG modulates neutrophil effector functions partly by controlling the release (and proteolysis) of FPR agonists. Unexpectedly, we found that mature CRAMP, but not Ac2-26, induced ROS production through an FPR-independent pathway.

  13. Lysosomal enlargement and lysosomal membrane destabilisation in mussel digestive cells measured by an integrative index

    Energy Technology Data Exchange (ETDEWEB)

    Izagirre, Urtzi [Cell Biology in Environmental Toxicology Research Group, Department of Zoology and Cell Biology, School of Sciences and Technology, University of the Basque Country, P.O. box 644, E-48080 Bilbo (Spain); Marigomez, Ionan, E-mail: ionan.marigomez@ehu.e [Cell Biology in Environmental Toxicology Research Group, Department of Zoology and Cell Biology, School of Sciences and Technology, University of the Basque Country, P.O. box 644, E-48080 Bilbo (Spain)

    2009-05-15

    Lysosomal responses (enlargement and membrane destabilisation) in mussel digestive cells are well-known environmental stress biomarkers in pollution effects monitoring in marine ecosystems. Presently, in laboratory and field studies, both responses were measured separately (in terms of lysosomal volume density - Vv - and labilisation period -LP) and combined (lysosomal response index - LRI) in order to contribute to their understanding and to develop an index useful for decisions makers. LRI integrates Vv and LP, which are not necessarily dependent lysosomal responses. It is unbiased and more sensitive than Vv and LP alone and diminishes background due to confounding factors. LRI provides a simple numerical index (consensus reference = 0; critical threshold = 1) directly related to the pollution impact degree. Moreover, LRI can be represented in a way that allows the interpretation of lysosomal responses, which is useful for environmental scientists. - Lysosomal responses to pollutants measured by an integrative index.

  14. Localization of acid hydrolases in protoplasts. Examination of the proposed lysosomal function of the mature vacuole

    Energy Technology Data Exchange (ETDEWEB)

    Butcher, H.C.; Wagner, G.J.; Siegelman, H.W.

    1977-06-01

    The development of techniques to isolate and purify relatively large quantities of intact vacuoles from mature tissues permits direct biochemical analysis of this ubiquitous mature plant cell organelle. Vacuoles and a fraction enriched in soluble cytoplasmic constituents were quantitatively prepared from Hippeastrum flower petal protoplasts. Vacuolar lysate and soluble cytoplasmic fractions were examined for acid hydrolase activities commonly associated with animal lysosomes, and pH optima were determined. Esterase, protease, carboxypeptidase, ..beta..-galactosidase, ..cap alpha..-glycosidase and ..beta..-glycosidase, not found in the vacuole lysate fraction, were components of the soluble cytoplasmic fraction. Acid phosphatase, RNase and DNase were present in both fractions. Vacuolar enzyme activities were also examined as a function of flower development from bud through senescent stages. The data obtained are not consistent with the concept that the mature plant cell vacuole functions as a generalized lysosome.

  15. Identification of interleukin-8 converting enzyme as cathepsin L.

    Science.gov (United States)

    Ohashi, Kensaku; Naruto, Masanobu; Nakaki, Toshio; Sano, Emiko

    2003-06-26

    IL-8 is produced by various cells, and the NH(2)-terminal amino acid sequence of IL-8 displays heterogeneity among cell types. The mature form of IL-8 has 72 amino acids (72IL-8), while a precursor form (77IL-8) of IL-8 has five additional amino acids to the 72IL-8 NH(2)-terminal. However, it has been unclear how IL-8 is processed to yield the mature form. In this study, converting enzyme was purified as a single 31-kDa band on silver-stained polyacrylamide gel from 160 l of cultured fibroblast supernatant by sequential chromatography. NH(2)-terminal amino acid sequence analysis revealed a sequence, EAPRSVDWRE, which was identified as a partial sequence of cathepsin L. Polyclonal antibodies raised against cathepsin L recognized the purified converting enzyme on Western blot. Moreover, human hepatic cathepsin L cleaved 77IL-8 between Arg(5) and Ser(6), which is the same cleavage site as the putative converting enzyme, resulting in 72IL-8 formation. These data indicate that the converting enzyme of the partially purified fraction of the human fibroblast culture supernatant was cathepsin L. Furthermore, 72IL-8 was sevenfold more potent than 77IL-8 in a neutrophil chemotaxis assay. These results show that cathepsin L is secreted from human fibroblasts in response to external stimuli and plays an important role in IL-8 processing in inflammatory sites.

  16. Lysosomal exoglycosidases in nasal polyps.

    Science.gov (United States)

    Chojnowska, Sylwia; Minarowska, Alina; Knaś, Małgorzata; Niemcunowicz-Janica, Anna; Kołodziejczyk, Paweł; Zalewska-Szajda, Beata; Kępka, Alina; Minarowski, Łukasz; Waszkiewicz, Napoleon; Zwierz, Krzysztof; Szajda, Sławomir Dariusz

    2013-01-01

    Nasal polyps are smooth outgrowths assuming a shape of grapes, formed from the nasal mucosa, limiting air flow by projecting into a lumen of a nasal cavity. Up to now the surgical resection is the best method of their treatment, but etiology and pathogenesis of the nasal polyps is not yet fully established. The aim of the study was the assessment of the selected lysosomal exoglycosidases activity in the nasal polyps. In this study the activity of β-galactosidase, α-mannosidase and α-fucosidase was determined in the tissue of the nasal polyps obtained from 40 patients (10F, 30M) and control tissues derived from mucosa of lower nasal conchas obtained during mucotomy from 20 patients (10F, 10M). We observed significant lower values of GAL, FUC and tendency to decrease of MAN and GLU concentration in nasal polyps (P) in comparison to control healthy nasal mucosa (C). In nasal polyp tissue (P) no differences of GAL, MAN and FUC specific activity in comparison to control mucosa (C) were found. Our research supports bioelectrical theory of the nasal polyps pathogenesis and directs attention at research on glycoconjugates and glycosidases of the nasal mucosa extracellular matrix. Copyright © 2013 Polish Otorhinolaryngology - Head and Neck Surgery Society. Published by Elsevier Urban & Partner Sp. z.o.o. All rights reserved.

  17. ADAM30 Downregulates APP-Linked Defects Through Cathepsin D Activation in Alzheimer's Disease

    Directory of Open Access Journals (Sweden)

    Florent Letronne

    2016-07-01

    Full Text Available Although several ADAMs (A disintegrin-like and metalloproteases have been shown to contribute to the amyloid precursor protein (APP metabolism, the full spectrum of metalloproteases involved in this metabolism remains to be established. Transcriptomic analyses centred on metalloprotease genes unraveled a 50% decrease in ADAM30 expression that inversely correlates with amyloid load in Alzheimer's disease brains. Accordingly, in vitro down- or up-regulation of ADAM30 expression triggered an increase/decrease in Aβ peptides levels whereas expression of a biologically inactive ADAM30 (ADAM30mut did not affect Aβ secretion. Proteomics/cell-based experiments showed that ADAM30-dependent regulation of APP metabolism required both cathepsin D (CTSD activation and APP sorting to lysosomes. Accordingly, in Alzheimer-like transgenic mice, neuronal ADAM30 over-expression lowered Aβ42 secretion in neuron primary cultures, soluble Aβ42 and amyloid plaque load levels in the brain and concomitantly enhanced CTSD activity and finally rescued long term potentiation alterations. Our data thus indicate that lowering ADAM30 expression may favor Aβ production, thereby contributing to Alzheimer's disease development.

  18. The Rhodococcus equi virulence protein VapA disrupts endolysosome function and stimulates lysosome biogenesis.

    Science.gov (United States)

    Rofe, Adam P; Davis, Luther J; Whittingham, Jean L; Latimer-Bowman, Elizabeth C; Wilkinson, Anthony J; Pryor, Paul R

    2017-04-01

    Rhodococcus equi (R. equi) is an important pulmonary pathogen in foals that often leads to the death of the horse. The bacterium harbors a virulence plasmid that encodes numerous virulence-associated proteins (Vaps) including VapA that is essential for intracellular survival inside macrophages. However, little is known about the precise function of VapA. Here, we demonstrate that VapA causes perturbation to late endocytic organelles with swollen endolysosome organelles having reduced Cathepsin B activity and an accumulation of LBPA, LC3 and Rab7. The data are indicative of a loss of endolysosomal function, which leads cells to upregulate lysosome biogenesis to compensate for the loss of functional endolysosomes. Although there is a high degree of homology of the core region of VapA to other Vap proteins, only the highly conserved core region of VapA, and not VapD of VapG, gives the observed effects on endolysosomes. This is the first demonstration of how VapA works and implies that VapA aids R. equi survival by reducing the impact of lysosomes on phagocytosed bacteria. © 2016 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  19. Early involvement of lysosome dysfunction in the degeneration of cerebral cortical neurons caused by the lipid peroxidation product 4-hydroxynonenal.

    Science.gov (United States)

    Zhang, Shi; Eitan, Erez; Mattson, Mark P

    2017-03-01

    Free radical-mediated oxidative damage to proteins, lipids, and DNA occurs in neurons during acute brain injuries and in neurodegenerative disorders. Membrane lipid peroxidation contributes to neuronal dysfunction and death, in part by disrupting neuronal ion homeostasis and cellular bioenergetics. Emerging findings suggest that 4-hydroxynonenal (HNE), an aldehyde produced during lipid peroxidation, impairs the function of various proteins involved in neuronal homeostasis. Here we tested the hypothesis that HNE impairs the cellular system that removes damaged proteins and organelles, the autophagy-lysosome pathway in rat primary cortical neurons. We found that HNE, at a concentration that causes apoptosis over a 48-72 h period, increases protein levels of LC3 II and p62 and within 1 and 4 h of exposure, respectively; LC3 II and p62 immunoreactive puncta were observed in the cytoplasm of HNE-treated neurons at 6 h. The extent of up-regulation of p62 and LC3 II in response to HNE was not affected by co-treatment with the lysosome inhibitor bafilomycin A1, suggesting that the effects of HNE on autophagy were secondary to lysosome inhibition. Indeed, we found that neurons exposed to HNE exhibit elevated pH levels, and decreased protein substrate hydrolysis and cathepsin B activity. Neurons exposed to HNE also exhibited the accumulation of K63-linked polyubiquitinated proteins, which are substrates targeted for lysosomal degradation. Moreover, we found that the levels of LAMP2a and constitutively active heat-shock protein 70, and numbers of LAMP2a-positive lysosomes, are decreased in neurons exposed to HNE. Our findings demonstrate that the lipid peroxidation product HNE causes early impairment of lysosomes which may contribute to the accumulation of damaged and dysfunctional proteins and organelles and consequent neuronal death. Because impaired lysosome function is increasingly recognized as an early event in the neuronal death that occurs in neurodegenerative

  20. Presenilin 1 maintains lysosomal Ca2+ homeostasis by regulating vATPase-mediated lysosome acidification

    Science.gov (United States)

    Lee, Ju-Hyun; McBrayer, Mary Kate; Wolfe, Devin M.; Haslett, Luke J.; Kumar, Asok; Sato, Yutaka; Lie, Pearl P. Y.; Mohan, Panaiyur; Coffey, Erin E.; Kompella, Uday; Mitchell, Claire H.; Lloyd-Evans, Emyr; Nixon, Ralph A.

    2015-01-01

    Summary Presenilin-1 (PS1) deletion or Alzheimer’s Disease (AD)-linked mutations disrupt lysosomal acidification and proteolysis, which inhibits autophagy. Here, we establish that this phenotype stems from impaired glycosylation and instability of vATPase V0a1 subunit causing deficient lysosomal vATPase assembly and function. We further demonstrate that elevated lysosomal pH in PS1KO cells induces abnormal Ca2+ efflux from lysosomes mediated by TRPML1 and elevates cytosolic Ca2+. In WT cells, blocking vATPase activity or knockdown of either PS1 or the V0a1 subunit of vATPase reproduces all of these abnormalities. Normalizing lysosomal pH in PS1KO cells using acidic nanoparticles restores normal lysosomal proteolysis, autophagy, and Ca2+ homeostasis, but correcting lysosomal Ca2+ deficits alone neither re-acidifies lysosomes nor reverses proteolytic and autophagic deficits. Our results indicate that vATPase deficiency in PS1 loss of function states causes lysosomal/autophagy deficits and contributes to abnormal cellular Ca2+ homeostasis, thus linking two AD-related pathogenic processes through a common molecular mechanism. PMID:26299959

  1. Lipid storage disorders block lysosomal trafficking by inhibiting a TRP channel and lysosomal calcium release.

    Science.gov (United States)

    Shen, Dongbiao; Wang, Xiang; Li, Xinran; Zhang, Xiaoli; Yao, Zepeng; Dibble, Shannon; Dong, Xian-ping; Yu, Ting; Lieberman, Andrew P; Showalter, Hollis D; Xu, Haoxing

    2012-03-13

    Lysosomal lipid accumulation, defects in membrane trafficking and altered Ca(2+) homoeostasis are common features in many lysosomal storage diseases. Mucolipin transient receptor potential channel 1 (TRPML1) is the principle Ca(2+) channel in the lysosome. Here we show that TRPML1-mediated lysosomal Ca(2+) release, measured using a genetically encoded Ca(2+) indicator (GCaMP3) attached directly to TRPML1 and elicited by a potent membrane-permeable synthetic agonist, is dramatically reduced in Niemann-Pick (NP) disease cells. Sphingomyelins (SMs) are plasma membrane lipids that undergo sphingomyelinase (SMase)-mediated hydrolysis in the lysosomes of normal cells, but accumulate distinctively in lysosomes of NP cells. Patch-clamp analyses revealed that TRPML1 channel activity is inhibited by SMs, but potentiated by SMases. In NP-type C cells, increasing TRPML1's expression or activity was sufficient to correct the trafficking defects and reduce lysosome storage and cholesterol accumulation. We propose that abnormal accumulation of luminal lipids causes secondary lysosome storage by blocking TRPML1- and Ca(2+)-dependent lysosomal trafficking.

  2. Cathepsin B antisense oligodeoxynucleotide suppresses invasive potential of MG-63 cells

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Objective To study the biological effects of cathepsin B phosporothioated antisense oligodeoxynucleotide on human osteosarcoma cell line MG-63 after transfection.Methods A 18-mer phosphorothioate antisense oligodeoxynucleotide(ASODN)targeted against the cathepsin B mRNA was transfected into the human osteosarcoma cell line MG-63 by lipofectamine 2000.The sense and nonsense oligodeoxynucleotides to cathepsin B and blank vector were used as controls.The expression of cathepsin B mRNA was examined by RT-PCR an...

  3. Cathepsin B is up-regulated and mediates extracellular matrix degradation in trabecular meshwork cells following phagocytic challenge.

    Directory of Open Access Journals (Sweden)

    Kristine Porter

    Full Text Available Cells in the trabecular meshwork (TM, a tissue responsible for draining aqueous humor out of the eye, are known to be highly phagocytic. Phagocytic activity in TM cells is thought to play an important role in outflow pathway physiology. However, the molecular mechanisms triggered by phagocytosis in TM cells are unknown. Here we investigated the effects of chronic phagocytic stress on lysosomal function using different phagocytic ligands (E. coli, carboxylated beads, collagen I-coated beads, and pigment. Lysotracker red co-localization and electron micrographs showed the maturation of E. coli- and collagen I-coated beads-containing phagosomes into phagolysosomes. Maturation of phagosomes into phagolysosomes was not observed with carboxylated beads or pigment particles. In addition, phagocytosis of E. coli and collagen I-coated beads led to increased lysosomal mass, and the specific up-regulation and activity of cathepsin B (CTSB. Higher levels of membrane-bound and secreted CTSB were also detected. Moreover, in vivo zymography showed the intralysosomal degradation of ECM components associated with active CTSB, as well as an overall increased gelatinolytic activity in phagocytically challenged TM cells. This increased gelatinolytic activity with phagocytosis was partially blocked with an intracellular CTSB inhibitor. Altogether, these results suggest a potential role of phagocytosis in outflow pathway tissue homeostasis through the up-regulation and/or proteolytic activation of extracellular matrix remodeling genes.

  4. Novel fungal protease.

    NARCIS (Netherlands)

    Buxton, F.; Jarai, G.; Visser, J.

    1994-01-01

    The present invention concerns a novel DNA sequence coding for an Aspergillus serine protease of the subtilisin-type, an Aspergillus serine protease of the subtilisin-type per se and a method for the preparation thereof. The invention further concerns a novel Aspergillus mutant strain defective in a

  5. Therapeutic dosing of an orally active, selective cathepsin S inhibitor suppresses disease in models of autoimmunity

    NARCIS (Netherlands)

    Baugh, Mark; Black, Darcey; Westwood, Paul; Kinghorn, Emma; McGregor, Kieran; Bruin, John; Hamilton, William; Dempster, Maureen; Claxton, Christopher; Cai, Jiaqiang; Bennett, Jonathan; Long, Clive; Mckinnon, Heather; Vink, Paul; den Hoed, Leontien; Gorecka, Monika; Vora, Kalpit; Grant, Ethan; Percival, M. David; Boots, A. Mieke H.; van Lierop, Marie-Jose; Boots, Annemieke

    2011-01-01

    The purpose of the study was to examine the potential of inhibition of cathepsin S as a treatment for autoimmune diseases. A highly selective cathepsin S inhibitor, CSI-75, was shown to upregulate levels of the cathepsin S substrate, invariant chain Lip10, in vitro as well as in vivo in C57Bl/6 mice

  6. Triterpenoids as novel natural inhibitors of human cathepsin L.

    Science.gov (United States)

    Ramalho, Suelem D; De Sousa, Lorena R F; Nebo, Liliane; Maganhi, Stella H; Caracelli, Ignez; Zukerman-Schpector, Julio; Lima, Maria Inês S; Alves, Marcio F M; Da Silva, M Fátima das G F; Fernandes, João B; Vieira, Paulo C

    2014-09-01

    Cathepsins L (catL) and B play an important role in tumor progression and have been considered promising therapeutic targets in the development of novel anticancer agents. Using a bioactivity-guided fractionation, a series of triterpenoids was identified as a new class of competitive inhibitors towards cathepsin L with affinity values in micromolar range. Among the 14 compounds evaluated, the most promising were 3-epiursolic acid (3), 3-(hydroxyimino)oleanolic acid (9), and 3-(hydroxyimino)masticadienoic acid (13) with IC50 values of 6.5, 2.4, and 2.6 μM on catL, respectively. Most of the evaluated triterpenoids do not inhibit cathepsin B. Thus, the evaluated compounds exhibit a great potential to help in the design of new inhibitors with enhanced potency and affinity towards catL. Docking studies were performed in order to gain insight on the binding mode and SAR of these compounds.

  7. Anti-trypanosomal activity of non-peptidic nitrile-based cysteine protease inhibitors.

    Science.gov (United States)

    Burtoloso, Antonio C B; de Albuquerque, Sérgio; Furber, Mark; Gomes, Juliana C; Gonçalez, Cristiana; Kenny, Peter W; Leitão, Andrei; Montanari, Carlos A; Quilles, José Carlos; Ribeiro, Jean F R; Rocha, Josmar R

    2017-02-01

    The cysteine protease cruzipain is considered to be a validated target for therapeutic intervention in the treatment of Chagas disease. Anti-trypanosomal activity against the CL Brener strain of T. cruzi was observed in the 0.1 μM to 1 μM range for three nitrile-based cysteine protease inhibitors based on two scaffolds known to be associated with cathepsin K inhibition. The two compounds showing the greatest potency against the trypanosome were characterized by EC50 values (0.12 μM and 0.25 μM) that were an order of magnitude lower than the corresponding Ki values measured against cruzain, a recombinant form of cruzipain, in an enzyme inhibition assay. This implies that the anti-trypanosomal activity of these two compounds may not be explained only by the inhibition of the cruzain enzyme, thereby triggering a putative polypharmacological profile towards cysteine proteases.

  8. [Application of lysosomal detection in marine pollution monitoring: research progress].

    Science.gov (United States)

    Weng, You-Zhu; Fang, Yong-Qiang; Zhang, Yu-Sheng

    2013-11-01

    Lysosome is an important organelle existing in eukaryotic cells. With the development of the study on the structure and function of lysosome in recent years, lysosome is considered as a target of toxic substances on subcellular level, and has been widely applied abroad in marine pollution monitoring. This paper summarized the biological characteristics of lysosomal marker enzyme, lysosome-autophagy system, and lysosomal membrane, and introduced the principles and methods of applying lysosomal detection in marine pollution monitoring. Bivalve shellfish digestive gland and fish liver are the most sensitive organs for lysosomal detection. By adopting the lysosomal detection techniques such as lysosomal membrane stability (LMS) test, neutral red retention time (NRRT) assay, morphological measurement (MM) of lysosome, immunohistochemical (Ih) assay of lysosomal marker enzyme, and electron microscopy (EM), the status of marine pollution can be evaluated. It was suggested that the lysosome could be used as a biomarker for monitoring marine environmental pollution. The advantages and disadvantages of lysosomal detection and some problems worthy of attention were analyzed, and the application prospects of lysosomal detection were discussed.

  9. Lysosomal Storage Disorders and Malignancy

    Directory of Open Access Journals (Sweden)

    Gregory M. Pastores

    2017-02-01

    Full Text Available Lysosomal storage disorders (LSDs are infrequent to rare conditions caused by mutations that lead to a disruption in the usual sequential degradation of macromolecules or their transit within the cell. Gaucher disease (GD, a lipidosis, is among the most common LSD, with an estimated incidence of 1 in 40,000 among the Caucasian, non-Jewish population. Studies have indicated an increased frequency of polyclonal and monoclonal gammopathy among patients with GD. It has been shown that two major sphingolipids that accumulate in GD, namely, β-glucosylceramide 22:0 (βGL1-22 and glucosylsphingosine (LGL1, can be recognized by a distinct subset of CD1d-restricted human and murine type II natural killer T (NKT cells. Investigations undertaken in an affected mouse model revealed βGL1-22- and LGL1-specific NKT cells were present and constitutively promoted the expression of a T-follicular helper (TFH phenotype; injection of these lipids led to downstream induction of germinal center B cells, hypergammaglobulinemia, and the production of antilipid antibodies. Subsequent studies have found clonal immunoglobulin in 33% of sporadic human monoclonal gammopathies is also specific for the lysolipids LGL1 and lysophosphatidylcholine (LPC. Furthermore, substrate reduction ameliorated GD-associated gammopathy in mice. It had been hypothesized that chronic antigenic stimulation by the abnormal lipid storage and associated immune dysregulation may be the underlying mechanism for the increased incidence of monoclonal and polyclonal gammopathies, as well as an increased incidence of multiple myeloma in patients with GD. Current observations support this proposition and illustrate the value of investigations into rare diseases, which as ‘experiments of nature’ may provide insights into conditions found in the general population that continue to remain incompletely understood.

  10. Cellular Composition of the Spleen and Changes in Splenic Lysosomes in the Dynamics of Dyslipidemia in Mice Caused by Repeated Administration of Poloxamer 407.

    Science.gov (United States)

    Goncharova, N V; Shurlygina, A V; Mel'nikova, E V; Karmatskikh, O L; Avrorov, P A; Loktev, K V; Korolenko, T A

    2015-11-01

    We studied the effect of dyslipidemia induced by poloxamer 407 (300 mg/kg twice a week for 30 days) on cellular composition of the spleen and splenocyte lysosomes in mice. Changes in blood lipid profile included elevated concentrations of total cholesterol, aterogenic LDL, and triglycerides most pronounced in 24 h after the last poloxamer 407 injection; gradual normalization of lipid profile was observed in 4 days (except triglycerides) and 10 days. The most pronounced changes in the spleen (increase in organ weight and number of cells, inhibition in apoptosis, and reduced accumulation of vital dye acridine orange in lysosomes) were detected on day 4; on day 10, the indices returned to normal. Cathepsin D activity in the spleen also increased at these terms. The relationship between changes in the cellular composition of the spleen and dynamics of serum lipid profile in mice in dyslipidemia caused by repeated administrations of relatively low doses of poloxamer 407 is discussed.

  11. Cathepsin-D And Tnf-α in Bladder Cancer

    Directory of Open Access Journals (Sweden)

    T. Salman

    1996-01-01

    Full Text Available In a study of 34 normal healthy controls, 35 patients with urinary tract bilharziasis and 93 bladder cancer patients (62 of them are operable cases and 31 are non-operable ones, serum tumor necrosis factor alpha (TNF-α and cytosolic Cathepsin-D were estimated. Though both potential markers were elevated in bladder cancer patients, neither Cathepsin-D nor TNF-α showed associations of prognostic value since there were no positive correlations with tumor stages, grades or association of tumors with bilharzia ova or lymph node involvement.

  12. Differential expression of Cathepsin S and X in the spinal cord of a rat neuropathic pain model

    Directory of Open Access Journals (Sweden)

    Schmitz Beate

    2008-08-01

    Full Text Available Abstract Background Ample evidence suggests a substantial contribution of cellular and molecular changes in the spinal cord to the induction and persistence of chronic neuropathic pain conditions. While for a long time, proteases were mainly considered as protein degrading enzymes, they are now receiving growing interest as signalling molecules in the pain pathology. In the present study we focused on two cathepsins, CATS and CATX, and studied their spatiotemporal expression and activity during the development and progression of neuropathic pain in the CNS of the rat 5th lumbar spinal nerve transection model (L5T. Results Immediately after the lesion, both cathepsins, CATS and CATX, were upregulated in the spinal cord. Moreover, we succeeded in measuring the activity of CATX, which was substantially increased after L5T. The differential expression of these proteins exhibited the same spatial distribution and temporal progression in the spinal cord, progressing up to the medulla oblongata in the late phase of chronic pain. The cellular distribution of CATS and CATX was, however, considerably different. Conclusion The cellular distribution and the spatio-temporal development of the altered expression of CATS and CATX suggest that these proteins are important players in the spinal mechanisms involved in chronic pain induction and maintenance.

  13. Effect of vitamin E and human placenta cysteine peptidase inhibitor on expression of cathepsins B and L in implanted hepatoma Morris 5123 tumor model in Wistar rats

    Institute of Scientific and Technical Information of China (English)

    Tadeusz Sebzda; Piotr Hanczyc; Yousif Saleh; Bernice F Akinpelumi; Maciej Siewinski; Jerzy Rudnicki

    2005-01-01

    AIM: To examine the effectiveness of human placental inhibitors, by injecting vitamin E to rats with transplanted Norris-5123 hepatoma, on the expression of cathepsins B and L in tumor, liver, lung and blood sera after transplantation of Norris 5123 hepatoma.METHODS: Animals were divided into 10 groups receiving three different concentrations of vitamin E and inhibitors along or in combination and compared with negative control (healthy rats) and positive control (tumor rats). Effectiveness of treatment was evaluated with regard to survival time,tumor response and determination of the activities of proteolytic enzymes and their inhibitors using flurogenic substrates.RESULTS: Cathepsins B and L activities were elevated by 16-fold in comparison with negative control tissues, and their endogenous inhibitor activity decreased by 1.2-fold before treatment. In several cases, tumors completely disappeared following vitamin E plus human placental cyteine protease inhibitor (CPI) compared with controls.The number of complete tumor responses was higher when 20 m/kg vitamin E plus 400 μg of CPI was used, i.e.7/10 rats survived more than two mo. Cathepsins B and L were expressed significantly in tumor, liver, lung tissues and sera in parallel to the increasing of the endogenous inhibitor activity compared with the controls after treatment (P<0.0001).CONCLUSION: The data indicate formation of metastasis significantly reduced in treated rats, which might provide a therapeutic basis for anti-cancer therapy.

  14. Molecular characterization of cathepsin B from Clonorchis sinensis excretory/secretory products and assessment of its potential for serodiagnosis of clonorchiasis

    Directory of Open Access Journals (Sweden)

    Zhou Chenhui

    2011-07-01

    Full Text Available Abstract Background Cathepsin cysteine proteases play multiple roles in the life cycle of parasites such as food uptake, immune invasion and pathogenesis, making them valuable targets for diagnostic assays, vaccines and drugs. The purpose of this study was to identify a cathepsin B of Clonorchis sinensis (CsCB and to investigate its diagnostic value for human helminthiases. Results The predicted amino acid sequence of the cathepsin B of C. sinensis shared 63%, 52%, 50% identity with that of Schistosoma japonicum, Homo sapiens and Fasciola hepatica, respectively. Sequence encoding proenzyme of CsCB was overexpressed in Escherichia coli. Reverse transcription PCR experiments revealed that CsCB transcribed in both adult worm and metacercaria of C. sinensis. CsCB was identified as a C. sinensis excretory/secretory product by immunoblot assay, which was consistent with immunohistochemical localization showing that CsCB was especially expressed in the intestine of C. sinensis adults. Both ELISA and western blotting analysis showed recombinant CsCB could react with human sera from clonorchiasis and other helminthiases. Conclusions Our findings revealed that secreted CsCB may play an important role in the biology of C. sinensis and could be a diagnostic candidate for helminthiases.

  15. Proteolytic degradation of glutamate decarboxylase mediates disinhibition of hippocampal CA3 pyramidal cells in cathepsin D-deficient mice.

    Science.gov (United States)

    Shimizu, Tokiko; Hayashi, Yoshinori; Yamasaki, Ryo; Yamada, Jun; Zhang, Jian; Ukai, Kiyoharu; Koike, Masato; Mine, Kazunori; von Figura, Kurt; Peters, Christoph; Saftig, Paul; Fukuda, Takaichi; Uchiyama, Yasuo; Nakanishi, Hiroshi

    2005-08-01

    Although of clinical importance, little is known about the mechanism of seizure in neuronal ceroid lipofuscinosis (NCL). In the present study, we have attempted to elucidate the mechanism underlying the seizure of cathepsin D-deficient (CD-/-) mice that show a novel type of lysosomal storage disease with a phenotype resembling late infantile NCL. In hippocampal slices prepared from CD-/- mice at post-natal day (P)24, spontaneous burst discharges were recorded from CA3 pyramidal cells. At P24, the mean amplitude of IPSPs after stimulation of the mossy fibres was significantly smaller than that of wild-type mice, which was substantiated by the decreased level of gamma-aminobutyric acid (GABA) contents in the hippocampus measured by high-performance liquid chromatography (HPLC). At this stage, activated microglia were found to accumulate in the pyramidal cell layer of the hippocampal CA3 subfield of CD-/- mice. However, there was no significant change in the numerical density of GABAergic interneurons in the CA3 subfield of CD-/- mice at P24, estimated by counting the number of glutamate decarboxylase (GAD) 67-immunoreactive somata. In the hippocampus and the cortex of CD-/- mice at P24, some GABAergic interneurons displayed extremely high somatic granular immunoreactivites for GAD67, suggesting the lysosomal accumulation of GAD67. GAD67 levels in axon terminals abutting on to perisomatic regions of hippocampal CA3 pyramidal cells was not significantly changed in CD-/- mice even at P24, whereas the total protein levels of GAD67 in both the hippocampus and the cortex of CD-/- mice after P24 were significantly decreased as a result of degradation. Furthermore, the recombinant human GAD65/67 was rapidly digested by the lysosomal fraction prepared from the whole brain of wild-type and CD-/- mice. These observations strongly suggest that the reduction of GABA contents, presumably because of lysosomal degradation of GAD67 and lysosomal accumulation of its degraded forms

  16. Hsp70 stabilizes lysosomes and reverts Niemann-Pick disease-associated lysosomal pathology

    DEFF Research Database (Denmark)

    Kirkegaard, Thomas; Roth, Anke G; Petersen, Nikolaj H T

    2010-01-01

    inhibition of ASM, effectively revert the Hsp70-mediated stabilization of lysosomes. Notably, the reduced ASM activity in cells from patients with Niemann-Pick disease (NPD) A and B-severe lysosomal storage disorders caused by mutations in the sphingomyelin phosphodiesterase 1 gene (SMPD1) encoding for ASM...

  17. Evaluation of dipeptide nitriles as inhibitors of rhodesain, a major cysteine protease of Trypanosoma brucei.

    Science.gov (United States)

    Schirmeister, Tanja; Schmitz, Janina; Jung, Sascha; Schmenger, Torsten; Krauth-Siegel, R Luise; Gütschow, Michael

    2017-01-01

    A series of dipeptide nitriles known as inhibitors of mammalian cathepsins were evaluated for inhibition of rhodesain, the cathepsin L-like protease of Trypanosoma brucei. Compound 35 consisting of a Leu residue fitting into the S2 pocket and a triarylic moiety consisting of thiophene, a 1,2,4-oxadiazole and a phenyl ring fitting into the S3 pocket, and compound 33 with a 3-bromo-Phe residue (S2) and a biphenyl fragment (S3) were found to inhibit rhodesain in the single-digit nanomolar range. The observed steep structure-activity relationship could be explained by covalent docking simulations. With their high selectivity indices (ca. 200) and the good antitrypanosomal activity (8μM) the compounds represent promising starting points for new rhodesain inhibitors. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. The Effect of Washing and Inhibitor on Cathepsin Activity of Silver Carp

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The effect of washing and temperature on the activity of cathepsins of Silver carp was studied.The result showed that the activity of cathepsin L was higher than those of cathepsin B and H.The total catalysis activity of these three enzymes was the highest at 55℃ after washing.The inhibiting effect of soybean protein and potato starch on cathepsin L also had been studied,the results showed that soybean protein and potato starch could decrease activity of cathepsins L significantly.

  19. ErbB2-associated changes in the lysosomal proteome

    DEFF Research Database (Denmark)

    Nylandsted, Jesper; Becker, Andrea C; Bunkenborg, Jakob

    2011-01-01

    Late endosomes and lysosomes (hereafter referred to as lysosomes) play an essential role in the turnover of cellular macromolecules and organelles. Their biochemical characterization has so far depended on purification methods based on either density gradient centrifugations or magnetic...... purification of iron-loaded organelles. Owing to dramatic changes in lysosomal density and stability associated with lysosomal diseases and cancer, these methods are not optimal for the comparison of normal and pathological lysosomes. Here, we introduce an efficient method for the purification of intact...... lysosomes by magnetic immunoprecipitation with antibodies against the vacuolar-type H(+) -ATPase. Quantitative MS-based proteomics analysis of the obtained lysosomal membranes identified 60 proteins, most of which have previously been associated with the lysosomal compartment. Interestingly, the lysosomal...

  20. Cathepsin G-dependent modulation of platelet thrombus formation in vivo by blood neutrophils.

    Directory of Open Access Journals (Sweden)

    Nauder Faraday

    Full Text Available Neutrophils are consistently associated with arterial thrombotic morbidity in human clinical studies but the causal basis for this association is unclear. We tested the hypothesis that neutrophils modulate platelet activation and thrombus formation in vivo in a cathepsin G-dependent manner. Neutrophils enhanced aggregation of human platelets in vitro in dose-dependent fashion and this effect was diminished by pharmacologic inhibition of cathepsin G activity and knockdown of cathepsin G expression. Tail bleeding time in the mouse was prolonged by a cathepsin G inhibitor and in cathepsin G knockout mice, and formation of neutrophil-platelet conjugates in blood that was shed from transected tails was reduced in the absence of cathepsin G. Bleeding time was highly correlated with blood neutrophil count in wildtype but not cathepsin G deficient mice. In the presence of elevated blood neutrophil counts, the anti-thrombotic effect of cathepsin G inhibition was greater than that of aspirin and additive to it when administered in combination. Both pharmacologic inhibition of cathepsin G and its congenital absence prolonged the time for platelet thrombus to form in ferric chloride-injured mouse mesenteric arterioles. In a vaso-occlusive model of ischemic stroke, inhibition of cathepsin G and its congenital absence improved cerebral blood flow, reduced histologic brain injury, and improved neurobehavioral outcome. These experiments demonstrate that neutrophil cathepsin G is a physiologic modulator of platelet thrombus formation in vivo and has potential as a target for novel anti-thrombotic therapies.

  1. Mitochondrial Dysfunction in Lysosomal Storage Disorders

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    Mario de la Mata

    2016-10-01

    Full Text Available Lysosomal storage diseases (LSDs describe a heterogeneous group of rare inherited metabolic disorders that result from the absence or loss of function of lysosomal hydrolases or transporters, resulting in the progressive accumulation of undigested material in lysosomes. The accumulation of substances affects the function of lysosomes and other organelles, resulting in secondary alterations such as impairment of autophagy, mitochondrial dysfunction, inflammation and apoptosis. LSDs frequently involve the central nervous system (CNS, where neuronal dysfunction or loss results in progressive neurodegeneration and premature death. Many LSDs exhibit signs of mitochondrial dysfunction, which include mitochondrial morphological changes, decreased mitochondrial membrane potential (ΔΨm, diminished ATP production and increased generation of reactive oxygen species (ROS. Furthermore, reduced autophagic flux may lead to the persistence of dysfunctional mitochondria. Gaucher disease (GD, the LSD with the highest prevalence, is caused by mutations in the GBA1 gene that results in defective and insufficient activity of the enzyme β-glucocerebrosidase (GCase. Decreased catalytic activity and/or instability of GCase leads to accumulation of glucosylceramide (GlcCer and glucosylsphingosine (GlcSph in the lysosomes of macrophage cells and visceral organs. Mitochondrial dysfunction has been reported to occur in numerous cellular and mouse models of GD. The aim of this manuscript is to review the current knowledge and implications of mitochondrial dysfunction in LSDs.

  2. The development and characterization of an ELISA specifically detecting the active form of cathepsin K

    DEFF Research Database (Denmark)

    Sun, S; Karsdal, M A; Bay-Jensen, A C;

    2013-01-01

    OBJECTIVE: Cathepsin K plays essential roles in bone resorption and is intensely investigated as a therapeutic target for the treatment of osteoporosis. Hence an assessment of the active form of cathepsin K may provide important biological information in metabolic bone diseases, such as osteoporo......OBJECTIVE: Cathepsin K plays essential roles in bone resorption and is intensely investigated as a therapeutic target for the treatment of osteoporosis. Hence an assessment of the active form of cathepsin K may provide important biological information in metabolic bone diseases......, such as osteoporosis or ankylosing spondylitis. METHODS: Presently there are no robust assays for the assessment of active cathepsin K in serum, and therefore an ELISA specifically detecting the N-terminal of the active form of cathepsin K was developed. RESULTS: The assay was technically robust, with a lowest limit...... form. Quantification of the levels of active cathepsin K in supernatants of purified human osteoclasts compared to corresponding macrophages showed a 30-fold induction (p...

  3. Dysregulation of macrophage-secreted cathepsin B contributes to HIV-1-linked neuronal apoptosis.

    Directory of Open Access Journals (Sweden)

    Eillen J Rodriguez-Franco

    Full Text Available Chronic HIV infection leads to the development of cognitive impairments, designated as HIV-associated neurocognitive disorders (HAND. The secretion of soluble neurotoxic factors by HIV-infected macrophages plays a central role in the neuronal dysfunction and cell death associated with HAND. One potentially neurotoxic protein secreted by HIV-1 infected macrophages is cathepsin B. To explore the potential role of cathepsin B in neuronal cell death after HIV infection, we cultured HIV-1(ADA infected human monocyte-derived macrophages (MDM and assayed them for expression and activity of cathepsin B and its inhibitors, cystatins B and C. The neurotoxic activity of the secreted cathepsin B was determined by incubating cells from the neuronal cell line SK-N-SH with MDM conditioned media (MCM from HIV-1 infected cultures. We found that HIV-1 infected MDM secreted significantly higher levels of cathepsin B than did uninfected cells. Moreover, the activity of secreted cathepsin B was significantly increased in HIV-infected MDM at the peak of viral production. Incubation of neuronal cells with supernatants from HIV-infected MDM resulted in a significant increase in the numbers of apoptotic neurons, and this increase was reversed by the addition of either the cathepsin B inhibitor CA-074 or a monoclonal antibody to cathepsin B. In situ proximity ligation assays indicated that the increased neurotoxic activity of the cathepsin B secreted by HIV-infected MDM resulted from decreased interactions between the enzyme and its inhibitors, cystatins B and C. Furthermore, preliminary in vivo studies of human post-mortem brain tissue suggested an upregulation of cathepsin B immunoreactivity in the hippocampus and basal ganglia in individuals with HAND. Our results demonstrate that HIV-1 infection upregulates cathepsin B in macrophages, increases cathepsin B activity, and reduces cystatin-cathepsin interactions, contributing to neuronal apoptosis. These findings

  4. The recombinant prepro region of TvCP4 is an inhibitor of cathepsin L-like cysteine proteinases of Trichomonas vaginalis that inhibits trichomonal haemolysis.

    Science.gov (United States)

    Cárdenas-Guerra, Rosa Elena; Ortega-López, Jaime; Flores-Pucheta, Claudia Ivonne; Benítez-Cardoza, Claudia Guadalupe; Arroyo, Rossana

    2015-02-01

    Trichomonas vaginalis expresses multiple proteinases, mainly of the cysteine type (CPs). A cathepsin L-like 34kDa CP, designated TvCP4, is synthesized as a 305-amino-acid precursor protein. TvCP4 contains the prepro fragment and the catalytic triad that is typical of the papain-like CP family of clan CA. The aim of this work was to determine the function of the recombinant TvCP4 prepro region (ppTvCP4r) as a specific inhibitor of CPs. We cloned, expressed, and purified the recombinant TvCP4 prepro region. The conformation of the purified and refolded ppTvCP4r polypeptide was verified by circular dichroism spectroscopy and fluorescence emission spectra. The inhibitory effect of ppTvCP4r was tested on protease-resistant extracts from T. vaginalis using fluorogenic substrates for cathepsin L and legumain CPs. In 1-D zymograms, the inhibitory effect of ppTvCP4r on trichomonad CP proteolytic activity was observed in the ∼97, 65, 39, and 30 kDa regions. By using 2-D zymograms and mass spectrometry, several of the CPs inhibited by ppTvCP4r were identified. A clear reduction in the proteolytic activity of several cathepsin L-like protein spots (TvCP2, TvCP4, TvCP4-like, and TvCP39) was observed compared with the control zymogram. Moreover, pretreatment of live parasites with ppTvCP4r inhibited trichomonal haemolysis in a concentration dependent manner. These results confirm that the recombinant ppTvCP4 is a specific inhibitor of the proteolytic activity of cathepsin L-like T. vaginalis CPs that is useful for inhibiting virulence properties depending on clan CA papain-like CPs.

  5. Cardioprotection by a novel recombinant serine protease inhibitor in myocardial ischemia and reperfusion injury.

    Science.gov (United States)

    Murohara, T; Guo, J P; Lefer, A M

    1995-09-01

    Polymorphonuclear neutrophils (PMN) play an important role in myocardial ischemia/reperfusion (MI/R) injury; however, the role of neutrophilic proteases is less understood. The effects of a novel serine protease inhibitor (serpin), LEX032, were investigated in a murine model of MI (20 min) and R (24 hr) injury in vivo. LEX032 is a recombinant human alpha 1-antichymotrypsin in which six amino acid residues were replaced around the active center with those of alpha-1 protease inhibitor. LEX032 has the ability to inhibit both neutrophil elastase and cathepsin G, two major neutral serine proteases in neutrophils, as well as superoxide generation. LEX032 (25 or 50 mg/kg) administered i.v. 1 min before reperfusion significantly attenuated myocardial necrotic injury evaluated by cardiac creatine kinase loss compared to MI/R rats receiving only vehicle (P LEX032 as compared with rats receiving vehicle (P LEX032 also moderately attenuated leukotriene B4-stimulated PMN adherence to rat superior mesenteric artery endothelium and markedly diminished superoxide radical release from LTB4-stimulated PMN in vitro. In a glycogen-induced rat peritonitis model, LEX032 (50 mg/kg) significantly attenuated PMN transmigration into the peritoneal cavity in vivo. In conclusion, the recombinant serine protease inhibitor, LEX032, appears to be an effective agent for attenuating MI/R injury by inhibiting neutrophil-accumulation into the ischemic-reperfused myocardium and by inactivating cytotoxic metabolites (proteases and superoxide radical) released from neutrophils.

  6. Bacterial proteases and virulence

    DEFF Research Database (Denmark)

    Frees, Dorte; Brøndsted, Lone; Ingmer, Hanne

    2013-01-01

    Bacterial pathogens rely on proteolysis for variety of purposes during the infection process. In the cytosol, the main proteolytic players are the conserved Clp and Lon proteases that directly contribute to virulence through the timely degradation of virulence regulators and indirectly by providing....... These extracellular proteases are activated in complex cascades involving auto-processing and proteolytic maturation. Thus, proteolysis has been adopted by bacterial pathogens at multiple levels to ensure the success of the pathogen in contact with the human host....

  7. Identification of mouse cathepsin K structural elements that regulate the potency of odanacatib.

    Science.gov (United States)

    Law, Simon; Andrault, Pierre-Marie; Aguda, Adeleke H; Nguyen, Nham T; Kruglyak, Natasha; Brayer, Gary D; Brömme, Dieter

    2017-02-20

    Cathepsin K (CatK) is the predominant mammalian bone-degrading protease and thus an ideal target for antiosteoporotic drug development. Rodent models of osteoporosis are preferred due to their close reflection of the human disease and their ease of handling, genetic manipulation and economic affordability. However, large differences in the potency of CatK inhibitors for the mouse/rat vs. the human protease orthologs have made it impossible to use rodent models. This is even more of a problem considering that the most advanced CatK inhibitors, including odanacatib (ODN) and balicatib, failed in human clinical trials due to side effects and rodent models are not available to investigate the mechanism of these failures. Here, we elucidated the structural elements of the potency differences between mouse and human CatK (hCatK) using ODN. We determined and compared the structures of inhibitor-free mouse CatK (mCatK), hCatK and ODN bound to hCatK. Two structural differences were identified and investigated by mutational analysis. Humanizing subsite 2 in mCatK led to a 5-fold improvement of ODN binding, whereas the replacement of Tyr61 in mCatK with Asp resulted in an hCatK with comparable ODN potency. Combining both sites further improved the inhibition of the mCatK variant. Similar results were obtained for balicatib. These findings will allow the generation of transgenic CatK mice that will facilitate the evaluation of CatK inhibitor adverse effects and to explore routes to avoid them.

  8. Cathepsin K null mice show reduced adiposity during the rapid accumulation of fat stores.

    Directory of Open Access Journals (Sweden)

    Marcella Funicello

    Full Text Available Growing evidences indicate that proteases are implicated in adipogenesis and in the onset of obesity. We previously reported that the cysteine protease cathepsin K (ctsk is overexpressed in the white adipose tissue (WAT of obese individuals. We herein characterized the WAT and the metabolic phenotype of ctsk deficient animals (ctsk-/-. When the growth rate of ctsk-/- was compared to that of the wild type animals (WT, we could establish a time window (5-8 weeks of age within which ctsk-/-display significantly lower body weight and WAT size as compared to WT. Such a difference was not observable in older mice. Upon treatment with high fat diet (HFD for 12 weeks ctsk-/- gained significantly less weight than WT and showed reduced brown adipose tissue, liver mass and a lower percentage of body fat. Plasma triglycerides, cholesterol and leptin were significantly lower in HFD-fed-ctsk-/- as compared to HFD-fed WT animals. Adipocyte lipolysis rates were increased in both young and HFD-fed-ctsk-/-, as compared to WT. Carnitine palmitoyl transferase-1 activity, was higher in mitochondria isolated from the WAT of HFD treated ctsk-/- as compared to WT. Together, these data indicate that ctsk ablation in mice results in reduced body fat content under conditions requiring a rapid accumulation of fat stores. This observation could be partly explained by an increased release and/or utilization of FFA and by an augmented ratio of lipolysis/lipogenesis. These results also demonstrate that under a HFD, ctsk deficiency confers a partial resistance to the development of dyslipidemia.

  9. Neisseria gonorrhoeae activates the proteinase cathepsin B to mediate the signaling activities of the NLRP3 and ASC-containing inflammasome.

    Science.gov (United States)

    Duncan, Joseph A; Gao, Xi; Huang, Max Tze-Han; O'Connor, Brian P; Thomas, Christopher E; Willingham, Stephen B; Bergstralh, Daniel T; Jarvis, Gary A; Sparling, P Frederick; Ting, Jenny P-Y

    2009-05-15

    Neisseria gonorrhoeae is a common sexually transmitted pathogen that significantly impacts female fertility, neonatal health, and transmission of HIV worldwide. N. gonorrhoeae usually causes localized inflammation of the urethra and cervix by inducing production of IL-1beta and other inflammatory cytokines. Several NLR (nucleotide-binding domain, leucine-rich repeat) proteins are implicated in the formation of pro-IL-1beta-processing complexes called inflammasomes in response to pathogens. We demonstrate that NLRP3 (cryopyrin, NALP3) is the primary NLR required for IL-1beta/IL-18 secretion in response to N. gonorrhoeae in monocytes. We also show that N. gonorrhoeae infection promotes NLRP3-dependent monocytic cell death via pyronecrosis, a recently described pathway with morphological features of necrosis, including release of the strong inflammatory mediator HMBG1. Additionally, N. gonorrhoeae activates the cysteine protease cathepsin B as measured by the breakdown of a cathepsin B substrate. Inhibition of cathepsin B shows that this protease is an apical controlling step in the downstream activities of NLRP3 including IL-1beta production, pyronecrosis, and HMGB1 release. Nonpathogenic Neisseria strains (Neisseria cinerea and Neisseria flavescens) do not activate NLRP3 as robustly as N. gonorrhoeae. Conditioned medium from N. gonorrhoeae contains factors capable of initiating the NLRP3-mediated signaling events. Isolated N. gonorrhoeae lipooligosaccharide, a known virulence factor from this bacterium that is elaborated from the bacterium in the form of outer membrane blebs, activates both NLRP3-induced IL-1beta secretion and pyronecrosis. Our findings indicate that activation of NLRP3-mediated inflammatory response pathways is an important venue associated with host response and pathogenesis of N. gonorrhoeae.

  10. Lysosomal Ca(2+) homeostasis: role in pathogenesis of lysosomal storage diseases.

    Science.gov (United States)

    Lloyd-Evans, Emyr; Platt, Frances M

    2011-08-01

    Disrupted cellular Ca(2+) signaling is believed to play a role in a number of human diseases including lysosomal storage diseases (LSD). LSDs are a group of ∼50 diseases caused predominantly by mutations in lysosomal proteins that result in accumulation of macromolecules within the lysosome. We recently reported that Niemann-Pick type C (NPC) is the first human disease to be associated with defective lysosomal Ca(2+) uptake and defective NAADP-mediated lysosomal Ca(2+) release. These defects in NPC cells leads to the disruption in endocytosis and subsequent lipid storage that is a feature of this disease. In contrast, Chediak-Higashi Syndrome cells have been reported to have enhanced lysosomal Ca(2+) uptake whilst the TRPML1 protein defective in mucolipidosis type IV is believed to function as a Ca(2+) channel. In this review we provide a summary of the current knowledge on the role of lysosomal Ca(2+) signaling in the pathogenesis of this group of diseases.

  11. Endo-lysosomal dysfunction in human proximal tubular epithelial cells deficient for lysosomal cystine transporter cystinosin.

    Directory of Open Access Journals (Sweden)

    Ekaterina A Ivanova

    Full Text Available Nephropathic cystinosis is a lysosomal storage disorder caused by mutations in the CTNS gene encoding cystine transporter cystinosin that results in accumulation of amino acid cystine in the lysosomes throughout the body and especially affects kidneys. Early manifestations of the disease include renal Fanconi syndrome, a generalized proximal tubular dysfunction. Current therapy of cystinosis is based on cystine-lowering drug cysteamine that postpones the disease progression but offers no cure for the Fanconi syndrome. We studied the mechanisms of impaired reabsorption in human proximal tubular epithelial cells (PTEC deficient for cystinosin and investigated the endo-lysosomal compartments of cystinosin-deficient PTEC by means of light and electron microscopy. We demonstrate that cystinosin-deficient cells had abnormal shape and distribution of the endo-lysosomal compartments and impaired endocytosis, with decreased surface expression of multiligand receptors and delayed lysosomal cargo processing. Treatment with cysteamine improved surface expression and lysosomal cargo processing but did not lead to a complete restoration and had no effect on the abnormal morphology of endo-lysosomal compartments. The obtained results improve our understanding of the mechanism of proximal tubular dysfunction in cystinosis and indicate that impaired protein reabsorption can, at least partially, be explained by abnormal trafficking of endosomal vesicles.

  12. Electrochemical Protease Biosensor Based on Enhanced AC Voltammetry Using Carbon Nanofiber Nanoelectrode Arrays.

    Science.gov (United States)

    Swisher, Luxi Z; Syed, Lateef U; Prior, Allan M; Madiyar, Foram R; Carlson, Kyle R; Nguyen, Thu A; Hua, Duy H; Li, Jun

    2013-02-28

    We report an electrochemical method for measuring the activity of proteases using nanoelectrode arrays (NEAs) fabricated with vertically aligned carbon nanofibers (VACNFs). The VACNFs of ~150 nm in diameter and 3 to 5 μm in length were grown on conductive substrates and encapsulated in SiO2 matrix. After polishing and plasma etching, controlled VACNF tips are exposed to form an embedded VACNF NEA. Two types of tetrapeptides specific to cancer-mediated proteases legumain and cathepsin B are covalently attached to the exposed VACNF tip, with a ferrocene (Fc) moiety linked at the distal end. The redox signal of Fc can be measured with AC voltammetry (ACV) at ~1 kHz frequency on VACNF NEAs, showing distinct properties from macroscopic glassy carbon electrodes due to VACNF's unique interior structure. The enhanced ACV properties enable the kinetic measurements of proteolytic cleavage of the surface-attached tetrapeptides by proteases, further validated with a fluorescence assay. The data can be analyzed with a heterogeneous Michaelis-Menten model, giving "specificity constant" kcat /Km as (4.3 ± 0.8) × 10(4) M(-1)s(-1) for cathepsin B and (1.13 ± 0.38) × 10(4) M(-1)s(-1) for legumain. This method could be developed as portable multiplex electronic techniques for rapid cancer diagnosis and treatment monitoring.

  13. Different host cell proteases activate the SARS-coronavirus spike-protein for cell-cell and virus-cell fusion

    Science.gov (United States)

    Simmons, Graham; Bertram, Stephanie; Glowacka, Ilona; Steffen, Imke; Chaipan, Chawaree; Agudelo, Juliet; Lu, Kai; Rennekamp, Andrew J.; Hofmann, Heike; Bates, Paul; Pöhlmann, Stefan

    2011-01-01

    Severe acute respiratory syndrome coronavirus (SARS-CoV) poses a considerable threat to human health. Activation of the viral spike (S)-protein by host cell proteases is essential for viral infectivity. However, the cleavage sites in SARS-S and the protease(s) activating SARS-S are incompletely defined. We found that R667 was dispensable for SARS-S-driven virus-cell fusion and for SARS-S-activation by trypsin and cathepsin L in a virus-virus fusion assay. Mutation T760R, which optimizes the minimal furin consensus motif 758-RXXR-762, and furin overexpression augmented SARS-S-activity, but did not result in detectable SARS-S cleavage. Finally, SARS-S-driven cell-cell fusion was independent of cathepsin L, a protease essential for virus-cell fusion. Instead, a so far unknown leupeptin-sensitive host cell protease activated cellular SARS-S for fusion with target cells expressing high levels of ACE2. Thus, different host cell proteases activate SARS-S for virus-cell and cell-cell fusion and SARS-S cleavage at R667 and 758-RXXR-762 can be dispensable for SARS-S activation. PMID:21435673

  14. The antimalarial amodiaquine causes autophagic-lysosomal and proliferative blockade sensitizing human melanoma cells to starvation- and chemotherapy-induced cell death.

    Science.gov (United States)

    Qiao, Shuxi; Tao, Shasha; Rojo de la Vega, Montserrat; Park, Sophia L; Vonderfecht, Amanda A; Jacobs, Suesan L; Zhang, Donna D; Wondrak, Georg T

    2013-12-01

    Pharmacological inhibition of autophagic-lysosomal function has recently emerged as a promising strategy for chemotherapeutic intervention targeting cancer cells. Repurposing approved and abandoned non-oncological drugs is an alternative approach to the identification and development of anticancer therapeutics, and antimalarials that target autophagic-lysosomal functions have recently attracted considerable attention as candidates for oncological repurposing. Since cumulative research suggests that dependence on autophagy represents a specific vulnerability of malignant melanoma cells, we screened a focused compound library of antimalarials for antimelanoma activity. Here we report for the first time that amodiaquine (AQ), a clinical 4-aminoquinoline antimalarial with unexplored cancer-directed chemotherapeutic potential, causes autophagic-lysosomal and proliferative blockade in melanoma cells that surpasses that of its parent compound chloroquine. Monitoring an established set of protein markers (LAMP1, LC3-II, SQSTM1) and cell ultrastructural changes detected by electron microscopy, we observed that AQ treatment caused autophagic-lysosomal blockade in malignant A375 melanoma cells, a finding substantiated by detection of rapid inactivation of lysosomal cathepsins (CTSB, CTSL, CTSD). AQ-treatment was associated with early induction of energy crisis (ATP depletion) and sensitized melanoma cells to either starvation- or chemotherapeutic agent-induced cell death. AQ displayed potent antiproliferative effects, and gene expression array analysis revealed changes at the mRNA (CDKN1A, E2F1) and protein level (TP53, CDKN1A, CCND1, phospho-RB1 [Ser 780]/[Ser 807/811], E2F1) consistent with the observed proliferative blockade in S-phase. Taken together, our data suggest that the clinical antimalarial AQ is a promising candidate for repurposing efforts that aim at targeting autophagic-lysosomal function and proliferative control in malignant melanoma cells.

  15. Antimicrobial peptide LL-37 is both a substrate of Cathepsins S and K and a selective inhibitor of Cathepsin L

    NARCIS (Netherlands)

    Andrault, P.M.; Samsonov, S.A.; Weber, G.; Coquet, L.; Nazmi, K.; Bolscher, J.G.M.; Lalmanach, A.C.; Jouenne, T.; Brömme, D.; Pisabarro, M.T.; Lalmanach, G.; Lecaille, F.

    2015-01-01

    Lung cysteine cathepsins B, K, L, and S contribute to physiological and pathological processes including degradation of antimicrobial peptides/proteins (AMPs) such as surfactant protein SP-A, lactoferrin, secretory leukocyte peptidase inhibitor, and beta-defensins-2 and -3. Substantial amounts of

  16. Crystal Structures of TbCatB and rhodesain, potential chemotherapeutic targets and major cysteine proteases of Trypanosoma brucei.

    Directory of Open Access Journals (Sweden)

    Iain D Kerr

    Full Text Available BACKGROUND: Trypanosoma brucei is the etiological agent of Human African Trypanosomiasis, an endemic parasitic disease of sub-Saharan Africa. TbCatB and rhodesain are the sole Clan CA papain-like cysteine proteases produced by the parasite during infection of the mammalian host and are implicated in the progression of disease. Of considerable interest is the exploration of these two enzymes as targets for cysteine protease inhibitors that are effective against T. brucei. METHODS AND FINDINGS: We have determined, by X-ray crystallography, the first reported structure of TbCatB in complex with the cathepsin B selective inhibitor CA074. In addition we report the structure of rhodesain in complex with the vinyl-sulfone K11002. CONCLUSIONS: The mature domain of our TbCat*CA074 structure contains unique features for a cathepsin B-like enzyme including an elongated N-terminus extending 16 residues past the predicted maturation cleavage site. N-terminal Edman sequencing reveals an even longer extension than is observed amongst the ordered portions of the crystal structure. The TbCat*CA074 structure confirms that the occluding loop, which is an essential part of the substrate-binding site, creates a larger prime side pocket in the active site cleft than is found in mammalian cathepsin B-small molecule structures. Our data further highlight enhanced flexibility in the occluding loop main chain and structural deviations from mammalian cathepsin B enzymes that may affect activity and inhibitor design. Comparisons with the rhodesain*K11002 structure highlight key differences that may impact the design of cysteine protease inhibitors as anti-trypanosomal drugs.

  17. Cathepsin L is required for endothelial progenitor cell-induced neovascularization

    Energy Technology Data Exchange (ETDEWEB)

    Urbich, Carmen; Heeschen, Christopher; Aicher, Alexandra; Sasaki, Ken-ichiro; Bruhl, Thomas; Hofmann, Wolf K.; Peters, Christoph; Reinheckel, Thomas; Pennacchio, Len A.; Abolmaali, Nasreddin D.; Chavakis, Emmanouil; Zeiher, Andreas M.; Dimmeler, Stefanie

    2004-01-15

    Infusion of endothelial progenitor cells (EPCs), but not of mature endothelial cells (ECs), promotes neovascularization after ischemia. We performed a gene expression profiling of EPCs and ECs to identify genes, which might be important for the neovascularization capacity of EPCs. Intriguingly, the protease cathepsin L (CathL) was highly expressed in EPCs as opposed to ECs and is essential for matrix degradation and invasion by EPCs in vitro. CathL deficient mice showed impaired functional recovery after hind limb ischemia supporting the concept for an important role of CathL in postnatal neovascularization. Infused CathL deficient progenitor cells failed to home to sites of ischemia and to augment neovascularization. In contrast, over expression of CathL in mature ECs significantly enhanced their invasive activity and induced their neovascularization capacity in vivo. Taken together, CathL plays a crucial role for the integration of circulating EPCs into the ischemic tissue and is required for neovascularization mediated by EPCs.

  18. A contiguous compartment functions as endoplasmic reticulum and endosome/lysosome in Giardia lamblia.

    Science.gov (United States)

    Abodeely, Marla; DuBois, Kelly N; Hehl, Adrian; Stefanic, Sasa; Sajid, Mohammed; DeSouza, Wanderley; Attias, Marcia; Engel, Juan C; Hsieh, Ivy; Fetter, Richard D; McKerrow, James H

    2009-11-01

    The dynamic evolution of organelle compartmentalization in eukaryotes and how strictly compartmentalization is maintained are matters of ongoing debate. While the endoplasmic reticulum (ER) is classically envisioned as the site of protein cotranslational translocation, it has recently been proposed to have pluripotent functions. Using transfected reporter constructs, organelle-specific markers, and functional enzyme assays, we now show that in an early-diverging protozoan, Giardia lamblia, endocytosis and subsequent degradation of exogenous proteins occur in the ER or in an adjacent and communicating compartment. The Giardia endomembrane system is simple compared to those of typical eukaryotes. It lacks peroxisomes, a classical Golgi apparatus, and canonical lysosomes. Giardia orthologues of mammalian lysosomal proteases function within an ER-like tubulovesicular compartment, which itself can dynamically communicate with clathrin-containing vacuoles at the periphery of the cell to receive endocytosed proteins. These primitive characteristics support Giardia's proposed early branching and could serve as a model to study the compartmentalization of endocytic and lysosomal functions into organelles distinct from the ER. This system also may have functional similarity to the retrograde transport of toxins and major histocompatibility complex class I function in the ER of mammals.

  19. Lysosomal stress: a new player in perturbed lipid metabolism

    NARCIS (Netherlands)

    Gabriel, T.L.

    2017-01-01

    Lysosomes are involved in many different essential cellular processes, among others organelle and molecule degradation, exocytosis, cell energy metabolism, cholesterol and sphingolipid level regulation. Lysosomal stress has a strong impact on the immune system, affecting specially macrophages as the

  20. Lysosomal stress: a new player in perturbed lipid metabolism

    NARCIS (Netherlands)

    Gabriel, T.L.

    2017-01-01

    Lysosomes are involved in many different essential cellular processes, among others organelle and molecule degradation, exocytosis, cell energy metabolism, cholesterol and sphingolipid level regulation. Lysosomal stress has a strong impact on the immune system, affecting specially macrophages as the

  1. Activation of lysosomal function in the course of autophagy via mTORC1 suppression and autophagosome-lysosome fusion

    Institute of Scientific and Technical Information of China (English)

    Jing Zhou; Shi-Hao Tan; Valérie Nicolas; Chantal Bauvy; Nai-Di Yang; Jianbin Zhang; Yuan Xue

    2013-01-01

    Lysosome is a key subcellular organelle in the execution of the autophagic process and at present little is known whether lysosomal function is controlled in the process of autophagy.In this study,we first found that suppression of mammalian target of rapamycin (mTOR) activity by starvation or two mTOR catalytic inhibitors (PP242 and Torinl),but not by an allosteric inhibitor (rapamycin),leads to activation of lysosomal function.Second,we provided evidence that activation of lysosomal function is associated with the suppression of mTOR complex 1 (mTORC1),but not mTORC2,and the mTORC1 localization to lysosomes is not directly correlated to its regulatory role in lysosomal function.Third,we examined the involvement of transcription factor EB (TFEB) and demonstrated that TFEB activation following mTORC1 suppression is necessary but not sufficient for lysosomal activation.Finally,Atg5 or Atg7deletion or blockage of the autophagosome-lysosome fusion process effectively diminished lysosomal activation,suggesting that lysosomal activation occurring in the course of autophagy is dependent on antophagosome-lysosome fusion.Taken together,this study demonstrates that in the course of autophagy,lysosomal function is upregulated via a dual mechanism involving mTORC1 suppression and autophagosome-lysosome fusion.

  2. Activation of lysosomal function in the course of autophagy via mTORC1 suppression and autophagosome-lysosome fusion.

    Science.gov (United States)

    Zhou, Jing; Tan, Shi-Hao; Nicolas, Valérie; Bauvy, Chantal; Yang, Nai-Di; Zhang, Jianbin; Xue, Yuan; Codogno, Patrice; Shen, Han-Ming

    2013-04-01

    Lysosome is a key subcellular organelle in the execution of the autophagic process and at present little is known whether lysosomal function is controlled in the process of autophagy. In this study, we first found that suppression of mammalian target of rapamycin (mTOR) activity by starvation or two mTOR catalytic inhibitors (PP242 and Torin1), but not by an allosteric inhibitor (rapamycin), leads to activation of lysosomal function. Second, we provided evidence that activation of lysosomal function is associated with the suppression of mTOR complex 1 (mTORC1), but not mTORC2, and the mTORC1 localization to lysosomes is not directly correlated to its regulatory role in lysosomal function. Third, we examined the involvement of transcription factor EB (TFEB) and demonstrated that TFEB activation following mTORC1 suppression is necessary but not sufficient for lysosomal activation. Finally, Atg5 or Atg7 deletion or blockage of the autophagosome-lysosome fusion process effectively diminished lysosomal activation, suggesting that lysosomal activation occurring in the course of autophagy is dependent on autophagosome-lysosome fusion. Taken together, this study demonstrates that in the course of autophagy, lysosomal function is upregulated via a dual mechanism involving mTORC1 suppression and autophagosome-lysosome fusion.

  3. Glutamate alteration of glutamic acid decarboxylase (GAD) in GABAergic neurons: the role of cysteine proteases.

    Science.gov (United States)

    Monnerie, Hubert; Le Roux, Peter D

    2008-09-01

    Brain cell vulnerability to neurologic insults varies greatly, depending on their neuronal subpopulation. Among cells that survive a pathological insult such as ischemia or brain trauma, some may undergo morphological and/or biochemical changes that could compromise brain function. We previously reported that surviving cortical GABAergic neurons exposed to glutamate in vitro displayed an NMDA receptor (NMDAR)-mediated alteration in the levels of the GABA synthesizing enzyme glutamic acid decarboxylase (GAD65/67) [Monnerie, H., Le Roux, P., 2007. Reduced dendrite growth and altered glutamic acid decarboxylase (GAD) 65- and 67-kDa isoform protein expression from mouse cortical GABAergic neurons following excitotoxic injury in vitro. Exp. Neurol. 205, 367-382]. In this study, we examined the mechanisms by which glutamate excitotoxicity caused a change in cortical GABAergic neurons' GAD protein levels. Removing extracellular calcium prevented the NMDAR-mediated decrease in GAD protein levels, measured using Western blot techniques, whereas inhibiting calcium entry through voltage-gated calcium channels had no effect. Glutamate's effect on GAD protein isoforms was significantly attenuated by preincubation with the cysteine protease inhibitor N-Acetyl-L-Leucyl-L-Leucyl-L-norleucinal (ALLN). Using class-specific protease inhibitors, we observed that ALLN's effect resulted from the blockade of calpain and cathepsin protease activities. Cell-free proteolysis assay confirmed that both proteases were involved in glutamate-induced alteration in GAD protein levels. Together these results suggest that glutamate-induced excitotoxic stimulation of NMDAR in cultured cortical neurons leads to altered GAD protein levels from GABAergic neurons through intracellular calcium increase and protease activation including calpain and cathepsin. Biochemical alterations in surviving cortical GABAergic neurons in various disease states may contribute to the altered balance between excitation

  4. Mucolipidosis type IV protein TRPML1-dependent lysosome formation.

    Science.gov (United States)

    Miller, Austin; Schafer, Jessica; Upchurch, Cameron; Spooner, Ellen; Huynh, Julie; Hernandez, Sebastian; McLaughlin, Brooke; Oden, Liam; Fares, Hanna

    2015-03-01

    Lysosomes are dynamic organelles that undergo cycles of fusion and fission with themselves and with other organelles. Following fusion with late endosomes to form hybrid organelles, lysosomes are reformed as discrete organelles. This lysosome reformation or formation is a poorly understood process that has not been systematically analyzed and that lacks known regulators. In this study, we quantitatively define the multiple steps of lysosome formation and identify the first regulator of this process.

  5. Effects of ethanol, acetaldehyde and cholesteryl esters on pancreatic lysosomes.

    OpenAIRE

    Wilson, J S; Apte, M V; Thomas, M. C.; Haber, P S; Pirola, R C

    1992-01-01

    Recent studies indicate that altered lysosomal function may be involved in the early stages of pancreatic injury. Chronic consumption of ethanol increases rat pancreatic lysosomal fragility. The aim of this study is to determine whether the lysosomal fragility observed after chronic ethanol consumption is mediated by ethanol per se, its oxidative metabolite acetaldehyde or cholesteryl esters (substances which accumulate in the pancreas after ethanol consumption). Pancreatic lysosomes from cho...

  6. Lysosomal storage disease 2 - Pompe's disease

    NARCIS (Netherlands)

    van der Ploeg, Ans T.; Reuser, Arnold J. J.

    2008-01-01

    Pompe's disease, glycogen-storage disease type II, and acid maltase deficiency are alternative names for the same metabolic disorder. It is a pan-ethnic autosomal recessive trait characterised by acid alpha-glucosidase deficiency leading to lysosomal glycogen storage. Pompe's disease is also

  7. Transport of Lysosome-Related Organelles

    NARCIS (Netherlands)

    Jordens, Ingrid

    2005-01-01

    Many intracellular compartments, including (MHC class II-containing) lysosomes, melanosomes and phagosomes, move along microtubules in a bi-directional manner due to the alternating activities of the plus-end directed kinesin motor and the minus-end directed dynein-dynactin motor. However, it is lar

  8. Transport of Lysosome-Related Organelles

    NARCIS (Netherlands)

    Jordens, Ingrid

    2005-01-01

    Many intracellular compartments, including (MHC class II-containing) lysosomes, melanosomes and phagosomes, move along microtubules in a bi-directional manner due to the alternating activities of the plus-end directed kinesin motor and the minus-end directed dynein-dynactin motor. However, it is

  9. Lysosomal proteolysis: effects of aging and insulin.

    Science.gov (United States)

    Gromakova, I A; Konovalenko, O A

    2003-07-01

    Age-related characteristics of the effect of insulin on the activity of lysosomal proteolytic enzymes were studied. The relationship between the insulin effect on protein degradation and insulin degradation was analyzed. The effect of insulin on the activities of lysosomal enzymes was opposite in young and old rats (inhibitory in 3-month-old and stimulatory in 24-month-old animals). The activities of proteolytic enzymes were regulated by insulin in a glucose-independent manner: similar hypoglycemic effects of insulin in animals of different ages were accompanied by opposite changes in the activities of lysosomal enzymes. The inhibition of lysosomal enzymes by insulin in 3-month-old rats is consistent with a notion on the inhibitory effect of insulin on protein degradation. An opposite insulin effect in 24-month-old rats (i.e., stimulation of proteolytic activity by insulin) may be partly associated with attenuation of the degradation of insulin, resulting in disturbances in signaling that mediates the regulatory effects of insulin on protein degradation.

  10. TRPML: transporters of metals in lysosomes essential for cell survival?

    Science.gov (United States)

    Kiselyov, Kirill; Colletti, Grace A; Terwilliger, Austen; Ketchum, Kathleen; Lyons, Christopher W P; Quinn, James; Muallem, Shmuel

    2011-09-01

    Key aspects of lysosomal function are affected by the ionic content of the lysosomal lumen and, therefore, by the ion permeability in the lysosomal membrane. Such functions include regulation of lysosomal acidification, a critical process in delivery and activation of the lysosomal enzymes, release of metals from lysosomes into the cytoplasm and the Ca(2+)-dependent component of membrane fusion events in the endocytic pathway. While the basic mechanisms of lysosomal acidification have been largely defined, the lysosomal metal transport system is not well understood. TRPML1 is a lysosomal ion channel whose malfunction is implicated in the lysosomal storage disease Mucolipidosis Type IV. Recent evidence suggests that TRPML1 is involved in Fe(2+), Ca(2+) and Zn(2+) transport across the lysosomal membrane, ascribing novel physiological roles to this ion channel, and perhaps to its relatives TRPML2 and TRPML3 and illuminating poorly understood aspects of lysosomal function. Further, alterations in metal transport by the TRPMLs due to mutations or environmental factors may contribute to their role in the disease phenotype and cell death.

  11. A non-conserved miRNA regulates lysosomal function and impacts on a human lysosomal storage disorder

    DEFF Research Database (Denmark)

    Frankel, Lisa B; Di Malta, Chiara; Wen, Jiayu

    2014-01-01

    Sulfatases are key enzymatic regulators of sulfate homeostasis with several biological functions including degradation of glycosaminoglycans (GAGs) and other macromolecules in lysosomes. In a severe lysosomal storage disorder, multiple sulfatase deficiency (MSD), global sulfatase activity...

  12. Reactivation of Lysosomal Ca2+ Efflux Rescues Abnormal Lysosomal Storage in FIG4-Deficient Cells.

    Science.gov (United States)

    Zou, Jianlong; Hu, Bo; Arpag, Sezgi; Yan, Qing; Hamilton, Audra; Zeng, Yuan-Shan; Vanoye, Carlos G; Li, Jun

    2015-04-29

    Loss of function of FIG4 leads to Charcot-Marie-Tooth disease Type 4J, Yunis-Varon syndrome, or an epilepsy syndrome. FIG4 is a phosphatase with its catalytic specificity toward 5'-phosphate of phosphatidylinositol-3,5-diphosphate (PI3,5P2). However, the loss of FIG4 decreases PI3,5P2 levels likely due to FIG4's dominant effect in scaffolding a PI3,5P2 synthetic protein complex. At the cellular level, all these diseases share similar pathology with abnormal lysosomal storage and neuronal degeneration. Mice with no FIG4 expression (Fig4(-/-)) recapitulate the pathology in humans with FIG4 deficiency. Using a flow cytometry technique that rapidly quantifies lysosome sizes, we detected an impaired lysosomal fission, but normal fusion, in Fig4(-/-) cells. The fission defect was associated with a robust increase of intralysosomal Ca(2+) in Fig4(-/-) cells, including FIG4-deficient neurons. This finding was consistent with a suppressed Ca(2+) efflux of lysosomes because the endogenous ligand of lysosomal Ca(2+) channel TRPML1 is PI3,5P2 that is deficient in Fig4(-/-) cells. We reactivated the TRPML1 channels by application of TRPML1 synthetic ligand, ML-SA1. This treatment reduced the intralysosomal Ca(2+) level and rescued abnormal lysosomal storage in Fig4(-/-) culture cells and ex vivo DRGs. Furthermore, we found that the suppressed Ca(2+) efflux in Fig4(-/-) culture cells and Fig4(-/-) mouse brains profoundly downregulated the expression/activity of dynamin-1, a GTPase known to scissor organelle membranes during fission. This downregulation made dynamin-1 unavailable for lysosomal fission. Together, our study revealed a novel mechanism explaining abnormal lysosomal storage in FIG4 deficiency. Synthetic ligands of the TRPML1 may become a potential therapy against diseases with FIG4 deficiency.

  13. Docetaxel-induced prostate cancer cell death involves concomitant activation of caspase and lysosomal pathways and is attenuated by LEDGF/p75

    Directory of Open Access Journals (Sweden)

    Leoh Lai

    2009-08-01

    Full Text Available Abstract Background Hormone-refractory prostate cancer (HRPC is characterized by poor response to chemotherapy and high mortality, particularly among African American men when compared to other racial/ethnic groups. It is generally accepted that docetaxel, the standard of care for chemotherapy of HRPC, primarily exerts tumor cell death by inducing mitotic catastrophe and caspase-dependent apoptosis following inhibition of microtubule depolymerization. However, there is a gap in our knowledge of mechanistic events underlying docetaxel-induced caspase-independent cell death, and the genes that antagonize this process. This knowledge is important for circumventing HRPC chemoresistance and reducing disparities in prostate cancer mortality. Results We investigated mechanistic events associated with docetaxel-induced death in HRPC cell lines using various approaches that distinguish caspase-dependent from caspase-independent cell death. Docetaxel induced both mitotic catastrophe and caspase-dependent apoptosis at various concentrations. However, caspase activity was not essential for docetaxel-induced cytotoxicity since cell death associated with lysosomal membrane permeabilization still occurred in the presence of caspase inhibitors. Partial inhibition of docetaxel-induced cytotoxicity was observed after inhibition of cathepsin B, but not inhibition of cathepsins D and L, suggesting that docetaxel induces caspase-independent, lysosomal cell death. Simultaneous inhibition of caspases and cathepsin B dramatically reduced docetaxel-induced cell death. Ectopic expression of lens epithelium-derived growth factor p75 (LEDGF/p75, a stress survival autoantigen and transcription co-activator, attenuated docetaxel-induced lysosomal destabilization and cell death. Interestingly, LEDGF/p75 overexpression did not protect cells against DTX-induced mitotic catastrophe, and against apoptosis induced by tumor necrosis factor related apoptosis inducing ligand (TRAIL

  14. Neuroinflammatory paradigms in lysosomal storage diseases

    Directory of Open Access Journals (Sweden)

    Megan Elizabeth Bosch

    2015-10-01

    Full Text Available Lysosomal storage diseases (LSDs include approximately 70 distinct disorders that collectively account for 14% of all inherited metabolic diseases. LSDs are caused by mutations in various enzymes/proteins that disrupt lysosomal function, which impairs macromolecule degradation following endosome-lysosome and phagosome-lysosome fusion and autophagy, ultimately disrupting cellular homeostasis. LSDs are pathologically typified by lysosomal inclusions composed of a heterogeneous mixture of various proteins and lipids that can be found throughout the body. However, in many cases the CNS is dramatically affected, which may result from heightened neuronal vulnerability based on their post-mitotic state. Besides intrinsic neuronal defects, another emerging factor common to many LSDs is neuroinflammation, which may negatively impact neuronal survival and contribute to neurodegeneration. Microglial and astrocyte activation is a hallmark of many LSDs that affect the CNS, which often precedes and predicts regions where eventual neuron loss will occur. However, the timing, intensity, and duration of neuroinflammation may ultimately dictate the impact on CNS homeostasis. For example, a transient inflammatory response following CNS insult/injury can be neuroprotective, as glial cells attempt to remove the insult and provide trophic support to neurons. However, chronic inflammation, as seen in several LSDs, can promote neurodegeneration by creating a neurotoxic environment due to elevated levels of cytokines, chemokines, and pro-apoptotic molecules. Although neuroinflammation has been reported in several LSDs, the cellular basis and mechanisms responsible for eliciting neuroinflammatory pathways are just beginning to be defined. This review highlights the role of neuroinflammation in select LSDs and its potential contribution to neuron loss.

  15. Cowpea bruchid Callosobruchus maculatus uses a three-component strategy to overcome a plant defensive cysteine protease inhibitor.

    Science.gov (United States)

    Zhu-Salzman, K; Koiwa, H; Salzman, R A; Shade, R E; Ahn, J-E

    2003-04-01

    The soybean cysteine protease inhibitor, soyacystatin N (scN), negatively impacts growth and development of the cowpea bruchid, Callosobruchus maculatus[Koiwa et al. (1998) Plant J 14: 371-379]. However, the developmental delay and feeding inhibition caused by dietary scN occurred only during the early developmental stages (the 1st, 2nd and 3rd instars) of the cowpea bruchid. The 4th instar larvae reared on scN diet (adapted) exhibited rates of feeding and development which were comparable to those feeding on an scN-free diet (unadapted) prior to pupation. Total gut proteolytic capacity at this larval stage significantly increased in the scN-adapted insects. The elevated enzymatic activity was attributed to a differential expression of insect gut cysteine proteases (representing the major digestive enzymes), and of aspartic proteases. scN degradation by the gut extract was observed only in adapted bruchids, and this activity appeared to be a combined effect of scN-induced cysteine and aspartic proteases. Thirty cDNAs encoding cathepsin L-like cysteine proteases were isolated from insect guts, and they were differentially regulated by dietary scN. Our results suggest that the cowpea bruchid adapts to the challenge of scN by qualitative and quantitative remodelling of its digestive protease complement, and by activating scN-degrading protease activity.

  16. Cleavage of Histone 3 by Cathepsin D in the involuting mammary gland.

    Directory of Open Access Journals (Sweden)

    Zhila Khalkhali-Ellis

    Full Text Available The post-lactational regression of mammary gland is a complex multi-step process designed to conserve the biological function of the gland for next pregnancy. This developmental stage is a biological intrigue with great relevance to breast cancer research, and thus has been the subject of intensive scrutiny. Multipronged studies (microarray, proteomics profiling, animal knock-out models have provided a repertoire of genes critical to involution. However, the caveat of these approaches remains in their failure to reveal post-translational modification(s, an emerging and critical aspect of gene regulation in developmental processes and mammary gland remodeling. The massive surge in the lysosomal enzymes concurrent with the onset of involution has been known for decades, and considered essential for "clearance" purposes. However, functional significance of these enzymes in diverse biological processes distinct from their proteolytic activity is just emerging. Studies from our laboratory had indicated specific post-translational modifications of the aspartyl endopeptidase Cathepsin D (CatD at distinct stages mammary gland development. This study addresses the biological significance of these modifications in the involution process, and reveals that post-translational modifications drive CatD into the nucleus to cleave Histone 3. The cleavage of Histone 3 has been associated with cellular differentiation and could be critical instigator of involution process. From functional perspective, deregulated expression and increased secretion of CatD are associated with aggressive and metastatic phenotype of breast cancer. Thus unraveling CatD's physiological functions in mammary gland development will bridge the present gap in understanding its pro-tumorigenic/metastatic functions, and assist in the generation of tailored therapeutic approaches.

  17. Cathepsin B Regulates Collagen Expression by Fibroblasts via Prolonging TLR2/NF-κB Activation

    Directory of Open Access Journals (Sweden)

    Xue Li

    2016-01-01

    Full Text Available Fibroblasts are essential for tissue repair due to producing collagens, and lysosomal proteinase cathepsin B (CatB is involved in promoting chronic inflammation. We herein report that CatB regulates the expression of collagens III and IV by fibroblasts in response to a TLR2 agonist, lipopolysaccharide from Porphyromonas gingivalis (P.g. LPS. In cultured human BJ fibroblasts, mRNA expression of CatB was significantly increased, while that of collagens III and IV was significantly decreased at 24 h after challenge with P.g. LPS (1 μg/mL. The P.g. LPS-decreased collagen expression was completely inhibited by CA-074Me, the specific inhibitor of CatB. Surprisingly, expression of collagens III and IV was significantly increased in the primary fibroblasts from CatB-deficient mice after challenge with P.g. LPS. The increase of CatB was accompanied with an increase of 8-hydroxy-2′-deoxyguanosine (8-OHdG and a decrease of IκBα. Furthermore, the P.g. LPS-increased 8-OHdG and decreased IκBα were restored by CA-074Me. Moreover, 87% of CatB and 86% of 8-OHdG were colocalized with gingival fibroblasts of chronic periodontitis patients. The findings indicate the critical role of CatB in regulating the expression of collagens III and IV by fibroblasts via prolonging TLR2/NF-κB activation and oxidative stress. CatB-specific inhibitors may therefore improve chronic inflammation-delayed tissue repair.

  18. Inhibition of bone resorption by the cathepsin K inhibitor odanacatib is fully reversible.

    Science.gov (United States)

    Zhuo, Y; Gauthier, J-Y; Black, W C; Percival, M D; Duong, L T

    2014-10-01

    The cathepsin K (CatK) inhibitor odanacatib (ODN) is currently being developed for the treatment of osteoporosis. In clinical trials, efficacy and resolution of effect of ODN treatment on bone turnover biomarkers and accrued bone mass have been demonstrated. Here, we examine the effects of continuing treatment and discontinuation of ODN versus alendronate (ALN) on osteoclast (OC) function. First, accessibility and reversible engagement of active CatK in intracellular vesicles and resorption lacunae of actively resorbing OCs were demonstrated by the selective and reversible CatK inhibitors, BODIPY-L-226 (IC50=39nM) and L-873,724 (IC50=0.5nM). Next, mature human OCs on bone slices were treated with vehicle, ODN, or ALN for 2days, followed by either continuing with the same treatment, or replacement of the inhibitors by vehicle for additional times as specified per experimental conditions. Maintaining OCs on ODN or ALN significantly reduced CTx-I release compared to vehicle controls. However, only the treatment of OCs with ODN resulted in the formation of small shallow discrete resorption pits, retention of intracellular vesicles enriched with CatK and other lysosomal enzymes, increase in 1-CTP release and number of TRAP(+) OCs. Upon discontinuation of ODN treatment, OCs rapidly resumed bone resorption activity, as demonstrated by a return of OC functional markers (CTx-I, 1-CTP), cell number and size, morphology and number of resorption pits, and vesicular secretion of CatK toward the respective vehicle levels. As expected, discontinuation of ALN did not reverse the treatment-related inhibition of OC activity in the time frame of the experiment. In summary, this study demonstrated rapid kinetics of inhibition and reversibility of the effects of ODN on OC bone resorption, that differentiated the cellular mechanism of CatK inhibition from that of the bisphosphate antiresorptive ALN.

  19. Interventional value of total flavonoids from Rhizoma Drynariae on Cathepsin K, a potential target of osteoporosis.

    Science.gov (United States)

    Shi, Xiao-Lin; Liu, Kang; Wu, Lian-Guo

    2011-07-01

    Osteoporosis, the sixth most common disease in the world, is bringing increasingly serious harm to people's health. Cathepsin K, which plays an important role in bone resorption, is a potential target in the treatment of osteoporosis. Total flavonoids, the active ingredients in Rhizoma Drynariae, have shown obvious, therapeutic effect on osteoporosis. In previous studies, it was presumed that the mechanism for the therapeutic effect was through inhibiting the expression of Cathepsin K. However, there are still no detailed reports on some key issues such as the specific inhibitory results of total flavonoids on Cathepsin K and the pathway of inhibition and so on. Based on previous studies on total flavonoids from Rhizoma Drynariae, the pathway for the effect of, total flavonoids inhibiting Cathepsin K and their interventional value on Cathepsin K were analyzed in this paper, so as to explore the interventional feasibility and value of total flavonoids in Rhizoma Drynariae on Cathepsin K.

  20. Discovery of a New Class of Cathepsin K Inhibitors in Rhizoma Drynariae as Potential Candidates for the Treatment of Osteoporosis

    Science.gov (United States)

    Qiu, Zuo-Cheng; Dong, Xiao-Li; Dai, Yi; Xiao, Gao-Keng; Wang, Xin-Luan; Wong, Ka-Chun; Wong, Man-Sau; Yao, Xin-Sheng

    2016-01-01

    Rhizoma Drynariae (RD), as one of the most common clinically used folk medicines, has been reported to exert potent anti-osteoporotic activity. The bioactive ingredients and mechanisms that account for its bone protective effects are under active investigation. Here we adopt a novel in silico target fishing method to reveal the target profile of RD. Cathepsin K (Ctsk) is one of the cysteine proteases that is over-expressed in osteoclasts and accounts for the increase in bone resorption in metabolic bone disorders such as postmenopausal osteoporosis. It has been the focus of target based drug discovery in recent years. We have identified two components in RD, Kushennol F and Sophoraflavanone G, that can potentially interact with Ctsk. Biological studies were performed to verify the effects of these compounds on Ctsk and its related bone resorption process, which include the use of in vitro fluorescence-based Ctsk enzyme assay, bone resorption pit formation assay, as well as Receptor Activator of Nuclear factor κB (NF-κB) ligand (RANKL)-induced osteoclastogenesis using murine RAW264.7 cells. Finally, the binding mode and stability of these two compounds that interact with Ctsk were determined by molecular docking and dynamics methods. The results showed that the in silico target fishing method could successfully identify two components from RD that show inhibitory effects on the bone resorption process related to protease Ctsk. PMID:27999266

  1. Inhibition Of Prostate Cancer Skeletal Metastases By Targeting Cathepsin K

    Science.gov (United States)

    2010-02-01

    PTHrP -induced MCP-1 production by human bone marrow endothelial cells promotes osteosteoclastast differentiation and prostate cancer cell...Abbreviations: cathepsin K, CatK; osteoprotegerin, OPG; prostate cancer, PCa; parathyroid hormone-related protein, PTHrP ; zoledronic acid, ZA; Receptor...zoledronic acid (ZA) or parathyroid hormone-related protein ( PTHrP ) neutralizing antibody have been reported in cancer animal models to block the tumor

  2. l-Homocysteine-induced cathepsin V mediates the vascular endothelial inflammation in hyperhomocysteinaemia.

    Science.gov (United States)

    Leng, Yi-Ping; Ma, Ye-Shuo; Li, Xiao-Gang; Chen, Rui-Fang; Zeng, Ping-Yu; Li, Xiao-Hui; Qiu, Cheng-Feng; Li, Ya-Pei; Zhang, Zhen; Chen, Alex F

    2017-06-20

    Vascular inflammation, including the expression of inflammatory cytokines in endothelial cells, plays a critical role in hyperhomocysteinaemia-associated vascular diseases. Cathepsin V, specifically expressed in humans, is involved in vascular diseases through its elastolytic and collagenolytic activities. The aim of this study was to determine the effects of cathepsin V on l-homocysteine-induced vascular inflammation. A high methionine diet-induced hyperhomocysteinaemic mouse model was used to assess cathepsin V expression and vascular inflammation. Cultures of HUVECs were challenged with l-homocysteine and the cathepsin L/V inhibitor SID to assess the pro-inflammatory effects of cathepsin V. Transfection and antisense techniques were utilized to investigate the effects of cathepsin V on the dual-specificity protein phosphatases (DUSPs) and MAPK pathways. Cathepsin L (human cathepsin V homologous) was increased in the thoracic aorta endothelial cells of hyperhomocysteinaemic mice; l-homocysteine promoted cathepsin V expression in HUVECs. SID suppressed the activity of cathepsin V and reversed the up-regulation of inflammatory cytokines (IL-6, IL-8 and TNF-α), adhesion and chemotaxis of leukocytes and vascular inflammation induced by l-homocysteine in vivo and in vitro. Increased cathepsin V promoted the degradation of DUSP6 and DUSP7, phosphorylation and subsequent nuclear translocation of ERK1/2, phosphorylation of STAT1 and expression of IL-6, IL-8 and TNF-α. This study has identified a novel mechanism, which shows that l-homocysteine-induced upregulation of cathepsin V mediates vascular endothelial inflammation under high homocysteine condition partly via ERK1/2 /STAT1 pathway. This mechanism could represent a potential therapeutic target in hyperaemia-associated vascular diseases. © 2017 The British Pharmacological Society.

  3. Localization of cathepsins D, K, and L in degenerated human intervertebral discs.

    Science.gov (United States)

    Ariga, K; Yonenobu, K; Nakase, T; Kaneko, M; Okuda, S; Uchiyama, Y; Yoshikawa, H

    2001-12-15

    Localization of cathepsins D, K, and L in degenerated intervertebral discs was examined by immunohistochemistry. To determine the involvement of cathepsins in the pathomechanism of intervertebral disc degeneration by monitoring the immunolocalization of cathepsins in degenerated intervertebral disc tissue. Cathepsins D, K, and L are enzymes that contribute to the matrix destruction seen in the articular cartilage affected by osteoarthritis and rheumatoid arthritis. However, little is known about the contribution of these cathepsins to intervertebral disc degeneration. Paraffin-embedded sections of degenerated intervertebral disc tissue collected at the time of surgery (13 discs from 12 patients) were immunohistochemically stained with antibodies for cathepsins D, K, and L. For further characterization of the stained cells, immunohistochemical detection of CD68 and TRAP staining were performed. Hematoxylin and eosin staining revealed obvious signs of degeneration in all sections. Cathepsins D and L were immunolocalized in disc fibrochondrocytes at various sites exhibiting degeneration. Cathepsins K were found in tartrate-resistant acid phosphatase-positive multinucleated cells, in particular near the cleft within the cartilaginous endplate. However, few cells were positive for these cathepsins in anulus fibrosus that maintained the lamellar structure of collagen fibers. Marked expression of cathepsins D and L was observed at the site of degeneration. Cathepsins D and K localized in tartrate-resistant acid phosphatase-positive multinucleated cells existed at the cleft between the cartilaginous endplate and vertebral body. The site-specific localization of these cathepsins suggests the association of these proteinases with endplate separation and disorganization of the anulus fibrosus in degenerative spinal disorders.

  4. PARP-1 cleavage fragments: signatures of cell-death proteases in neurodegeneration

    Directory of Open Access Journals (Sweden)

    Alexander Jonathan S

    2010-12-01

    Full Text Available Abstract The normal function of poly (ADP-ribose polymerase-1 (PARP-1 is the routine repair of DNA damage by adding poly (ADP ribose polymers in response to a variety of cellular stresses. Recently, it has become widely appreciated that PARP-1 also participates in diverse physiological and pathological functions from cell survival to several forms of cell death and has been implicated in gene transcription, immune responses, inflammation, learning, memory, synaptic functions, angiogenesis and aging. In the CNS, PARP inhibition attenuates injury in pathologies like cerebral ischemia, trauma and excitotoxicity demonstrating a central role of PARP-1 in these pathologies. PARP-1 is also a preferred substrate for several 'suicidal' proteases and the proteolytic action of suicidal proteases (caspases, calpains, cathepsins, granzymes and matrix metalloproteinases (MMPs on PARP-1 produces several specific proteolytic cleavage fragments with different molecular weights. These PARP-1 signature fragments are recognized biomarkers for specific patterns of protease activity in unique cell death programs. This review focuses on specific suicidal proteases active towards PARP-1 to generate signature PARP-1 fragments that can identify key proteases and particular forms of cell death involved in pathophysiology. The roles played by some of the PARP-1 fragments and their associated binding partners in the control of different forms of cell death are also discussed.

  5. Insights into the Interactions of Fasciola hepatica Cathepsin L3 with a Substrate and Potential Novel Inhibitors through In Silico Approaches.

    Science.gov (United States)

    Hernández Alvarez, Lilian; Naranjo Feliciano, Dany; Hernández González, Jorge Enrique; Soares, R O; Soares, Rosemberg de Oliveira; Barreto Gomes, Diego Enry; Pascutti, Pedro Geraldo

    2015-05-01

    Fasciola hepatica is the causative agent of fascioliasis, a disease affecting grazing animals, causing economic losses in global agriculture and currently being an important human zoonosis. Overuse of chemotherapeutics against fascioliasis has increased the populations of drug resistant parasites. F. hepatica cathepsin L3 is a protease that plays important roles during the life cycle of fluke. Due to its particular collagenolytic activity it is considered an attractive target against the infective phase of F. hepatica. Starting with a three dimensional model of FhCL3 we performed a structure-based design of novel inhibitors through a computational study that combined virtual screening, molecular dynamics simulations, and binding free energy (ΔGbind) calculations. Virtual screening was carried out by docking inhibitors obtained from the MYBRIDGE-HitFinder database inside FhCL3 and human cathepsin L substrate-binding sites. On the basis of dock-scores, five compounds were predicted as selective inhibitors of FhCL3. Molecular dynamic simulations were performed and, subsequently, an end-point method was employed to predict ΔGbind values. Two compounds with the best ΔGbind values (-10.68 kcal/mol and -7.16 kcal/mol), comparable to that of the positive control (-10.55 kcal/mol), were identified. A similar approach was followed to structurally and energetically characterize the interface of FhCL3 in complex with a peptidic substrate. Finally, through pair-wise and per-residue free energy decomposition we identified residues that are critical for the substrate/ligand binding and for the enzyme specificity. The present study is the first computer-aided drug design approach against F. hepatica cathepsins. Here we predict the principal determinants of binding of FhCL3 in complex with a natural substrate by detailed energetic characterization of protease interaction surface. We also propose novel compounds as FhCL3 inhibitors. Overall, these results will foster the future

  6. Insights into the Interactions of Fasciola hepatica Cathepsin L3 with a Substrate and Potential Novel Inhibitors through In Silico Approaches.

    Directory of Open Access Journals (Sweden)

    Lilian Hernández Alvarez

    2015-05-01

    Full Text Available Fasciola hepatica is the causative agent of fascioliasis, a disease affecting grazing animals, causing economic losses in global agriculture and currently being an important human zoonosis. Overuse of chemotherapeutics against fascioliasis has increased the populations of drug resistant parasites. F. hepatica cathepsin L3 is a protease that plays important roles during the life cycle of fluke. Due to its particular collagenolytic activity it is considered an attractive target against the infective phase of F. hepatica.Starting with a three dimensional model of FhCL3 we performed a structure-based design of novel inhibitors through a computational study that combined virtual screening, molecular dynamics simulations, and binding free energy (ΔGbind calculations. Virtual screening was carried out by docking inhibitors obtained from the MYBRIDGE-HitFinder database inside FhCL3 and human cathepsin L substrate-binding sites. On the basis of dock-scores, five compounds were predicted as selective inhibitors of FhCL3. Molecular dynamic simulations were performed and, subsequently, an end-point method was employed to predict ΔGbind values. Two compounds with the best ΔGbind values (-10.68 kcal/mol and -7.16 kcal/mol, comparable to that of the positive control (-10.55 kcal/mol, were identified. A similar approach was followed to structurally and energetically characterize the interface of FhCL3 in complex with a peptidic substrate. Finally, through pair-wise and per-residue free energy decomposition we identified residues that are critical for the substrate/ligand binding and for the enzyme specificity.The present study is the first computer-aided drug design approach against F. hepatica cathepsins. Here we predict the principal determinants of binding of FhCL3 in complex with a natural substrate by detailed energetic characterization of protease interaction surface. We also propose novel compounds as FhCL3 inhibitors. Overall, these results will

  7. Insights into the Interactions of Fasciola hepatica Cathepsin L3 with a Substrate and Potential Novel Inhibitors through In Silico Approaches

    Science.gov (United States)

    Hernández Alvarez, Lilian; Naranjo Feliciano, Dany; Hernández González, Jorge Enrique; de Oliveira Soares, Rosemberg; Barreto Gomes, Diego Enry; Pascutti, Pedro Geraldo

    2015-01-01

    Background Fasciola hepatica is the causative agent of fascioliasis, a disease affecting grazing animals, causing economic losses in global agriculture and currently being an important human zoonosis. Overuse of chemotherapeutics against fascioliasis has increased the populations of drug resistant parasites. F. hepatica cathepsin L3 is a protease that plays important roles during the life cycle of fluke. Due to its particular collagenolytic activity it is considered an attractive target against the infective phase of F. hepatica. Methodology/Principal Findings Starting with a three dimensional model of FhCL3 we performed a structure-based design of novel inhibitors through a computational study that combined virtual screening, molecular dynamics simulations, and binding free energy (ΔGbind) calculations. Virtual screening was carried out by docking inhibitors obtained from the MYBRIDGE-HitFinder database inside FhCL3 and human cathepsin L substrate-binding sites. On the basis of dock-scores, five compounds were predicted as selective inhibitors of FhCL3. Molecular dynamic simulations were performed and, subsequently, an end-point method was employed to predict ΔGbind values. Two compounds with the best ΔGbind values (-10.68 kcal/mol and -7.16 kcal/mol), comparable to that of the positive control (-10.55 kcal/mol), were identified. A similar approach was followed to structurally and energetically characterize the interface of FhCL3 in complex with a peptidic substrate. Finally, through pair-wise and per-residue free energy decomposition we identified residues that are critical for the substrate/ligand binding and for the enzyme specificity. Conclusions/Significance The present study is the first computer-aided drug design approach against F. hepatica cathepsins. Here we predict the principal determinants of binding of FhCL3 in complex with a natural substrate by detailed energetic characterization of protease interaction surface. We also propose novel compounds

  8. Death proteases come alive

    NARCIS (Netherlands)

    Woltering, E.J.

    2004-01-01

    Cell death in plants exhibits morphological features comparable to caspase-mediated apoptosis in animals, suggesting that plant cell death is executed by (caspase-like) proteases. However, to date, no caspase homologues have been identified in plants and therefore the existence and nature of these p

  9. Activity of lysosomal exoglycosidases in human gliomas.

    Science.gov (United States)

    Wielgat, P; Walczuk, U; Szajda, S; Bień, M; Zimnoch, L; Mariak, Z; Zwierz, K

    2006-12-01

    There is a lot of data suggesting that modifications of cell glycoconjugates may be important in progression of cancer. In the present work we studied activities of lysosomal exoglycosidases: beta-hexosaminidase and its isoenzymes A and B, beta-galactosidase and alpha-mannosidase, in human gliomas. Enzyme activity was determined spectrophotometrically based on the release of p-nitrophenol from p-nitrophenyl-derivative of appropriate sugars. The activities of the exoglycosidases tested were significantly higher in malignant glial tumors than in control tissue (normal brain tissue) and non-glial tumors. The highest activities of exoglycosidases were observed in high-grade gliomas, and a positive correlation of enzyme activities and degree of malignancy was noted. Our results suggest that lysosomal exoglycosidases may participate in the progression and dynamical development of glial tumors.

  10. Thymol attenuates inflammation in isoproterenol induced myocardial infarcted rats by inhibiting the release of lysosomal enzymes and downregulating the expressions of proinflammatory cytokines.

    Science.gov (United States)

    Nagoor Meeran, Mohamed Fizur; Jagadeesh, Govindan Sangaran; Selvaraj, Palanisamy

    2015-05-05

    Inflammation plays an important role in the development of myocardial infarction (MI). The current study dealt with the protective effects of thymol on inflammation in isoproterenol (ISO) induced myocardial infarcted rats. Male albino Wistar rats were pre and co-treated with thymol (7.5mg/kg body weight) daily for 7 days. ISO (100mg/kg body weight) was injected subcutaneously into rats at an interval of 24h for two days (6th and 7th day) to induce MI. ISO induced myocardial infarcted rats showed increased levels of serum cardiac troponin-T, high sensitive C-reactive protein (hsCRP), lysosomal thiobarbituric acid reactive substances (TBARS) and elevated ST-segments. Also, the activities of lysosomal enzymes such as β-glucuronidase, β-galactosidase, cathepsin-B and D, the stimulators of inflammatory mediators were increased in the serum and heart of ISO induced myocardial infarcted rats. Furthermore, ISO up regulates the expressions of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) genes in the myocardium of rats analyzed by reverse transcription polymerase chain reaction (RT-PCR). Pre and co-treatment with thymol (7.5mg/kg body weight) near normalized the levels of lysosomal TBARS, activities of serum and heart lysosomal enzymes and downregulates the expressions of pro-inflammatory cytokines in the myocardium of ISO induced myocardial infarcted rats. Histopathological and transmission electron microscopic findings were also found in line with biochemical findings. Thus, the results of our study revealed that thymol attenuates inflammation by inhibiting the release of lysosomal enzymes and downregulates the expressions of pro-inflammatory cytokines by its potent anti-inflammatory effect.

  11. Regulation of lysosomal ion homeostasis by channels and transporters.

    Science.gov (United States)

    Xiong, Jian; Zhu, Michael X

    2016-08-01

    Lysosomes are the major organelles that carry out degradation functions. They integrate and digest materials compartmentalized by endocytosis, phagocytosis or autophagy. In addition to more than 60 hydrolases residing in the lysosomes, there are also ion channels and transporters that mediate the flux or transport of H(+), Ca(2+), Na(+), K(+), and Cl(-) across the lysosomal membranes. Defects in ionic exchange can lead to abnormal lysosome morphology, defective vesicle trafficking, impaired autophagy, and diseases such as neurodegeneration and lysosomal storage disorders. The latter are characterized by incomplete lysosomal digestion and accumulation of toxic materials inside enlarged intracellular vacuoles. In addition to degradation, recent studies have revealed the roles of lysosomes in metabolic pathways through kinases such as mechanistic target of rapamycin (mTOR) and transcriptional regulation through calcium signaling molecules such as transcription factor EB (TFEB) and calcineurin. Owing to the development of new approaches including genetically encoded fluorescence probes and whole endolysosomal patch clamp recording techniques, studies on lysosomal ion channels have made remarkable progress in recent years. In this review, we will focus on the current knowledge of lysosome-resident ion channels and transporters, discuss their roles in maintaining lysosomal function, and evaluate how their dysfunction can result in disease.

  12. Biphasic regulation of lysosomal exocytosis by oxidative stress.

    Science.gov (United States)

    Ravi, Sreeram; Peña, Karina A; Chu, Charleen T; Kiselyov, Kirill

    2016-11-01

    Oxidative stress drives cell death in a number of diseases including ischemic stroke and neurodegenerative diseases. A better understanding of how cells recover from oxidative stress is likely to lead to better treatments for stroke and other diseases. The recent evidence obtained in several models ties the process of lysosomal exocytosis to the clearance of protein aggregates and toxic metals. The mechanisms that regulate lysosomal exocytosis, under normal or pathological conditions, are only beginning to emerge. Here we provide evidence for the biphasic effect of oxidative stress on lysosomal exocytosis. Lysosomal exocytosis was measured using the extracellular levels of the lysosomal enzyme beta-hexosaminidase (ß-hex). Low levels or oxidative stress stimulated lysosomal exocytosis, but inhibited it at high levels. Deletion of the lysosomal ion channel TRPML1 eliminated the stimulatory effect of low levels of oxidative stress. The inhibitory effects of oxidative stress appear to target the component of lysosomal exocytosis that is driven by extracellular Ca(2+). We propose that while moderate oxidative stress promotes cellular repair by stimulating lysosomal exocytosis, at high levels oxidative stress has a dual pathological effect: it directly causes cell damage and impairs damage repair by inhibiting lysosomal exocytosis. Harnessing these adaptive mechanisms may point to pharmacological interventions for diseases involving oxidative proteotoxicity or metal toxicity.

  13. 线虫脂肪沉积中组织蛋白酶 B 的表达及功能研究%Study of expression and function of Cathepsin B in the process of fat storage in Caenorhabditis elegans

    Institute of Scientific and Technical Information of China (English)

    赵丽娟; 鲍斌

    2016-01-01

    In this paper ,Caenorhabditis elegans (C .elegans) were fed with high concentration glucose and cholesterol diet ,and it was demonstrated that the fat storage increased dramatically by oil red O staining .In order to study the role of Cathepsin B Protease homologous genes in the fat storage process of C .elegans ,their expression was investigated by quantitative reverse transcription-polymer-ase chain reaction (RT-PCR) .The cp r-3 was proposed as a critical gene homologous to Cathepsin B Protease ,and then the effect of selected critical genes on the fat storage in C .elegans was studied by RNAi technology .The results show that the altered expression of Cathepsin B Protease homologous genes maybe a result of the changed fat storage in C .elegans . However ,there is no change of fat storage when cp r-3 is knocked down by RNAi .In consequence ,homologous genes of Cathepsin B Protease do not directly regulate the fat storage ,but may participate in the physiological and patholog-ical processes after the increase of fat storage .%文章利用高糖/高胆固醇饮食诱导了线虫,油红 O 染色结果表明线虫脂肪沉积显著增加。为了研究组织蛋白酶 B 在诱导线虫过程中的作用,利用实时荧光定量聚合酶链式反应(polymerase chain reaction , PCR)研究了组织蛋白酶 B 同源基因的表达。选取其中的关键基因利用 RNA 干扰(RNA interference ,RNAi)技术,研究其在线虫脂肪沉积中的作用。结果表明:在线虫脂肪沉积改变后,组织蛋白酶 B 同源基因表达随之改变;而利用 RNA 干扰组织蛋白酶 B 关键基因 cp r-3的表达,线虫的脂肪沉积未受影响。因此,组织蛋白酶 B 同源基因可能参与线虫脂肪沉积改变后的生理变化,而未直接参与线虫脂肪沉积的调控。

  14. A potentially dynamic lysosomal role for the endogenous TRPML proteins.

    Science.gov (United States)

    Zeevi, David A; Frumkin, Ayala; Offen-Glasner, Vered; Kogot-Levin, Aviram; Bach, Gideon

    2009-10-01

    Lysosomal storage disorders (LSDs) constitute a diverse group of inherited diseases that result from lysosomal storage of compounds occurring in direct consequence to deficiencies of proteins implicated in proper lysosomal function. Pathology in the LSD mucolipidosis type IV (MLIV), is characterized by lysosomal storage of lipids together with water-soluble materials in cells from every tissue and organ of affected patients. Mutations in the mucolipin 1 (TRPML1) protein cause MLIV and TRPML1 has also been shown to interact with two of its paralogous proteins, mucolipin 2 (TRPML2) and mucolipin 3 (TRPML3), in heterologous expression systems. Heterogeneous lysosomal storage is readily identified in electron micrographs of MLIV patient cells, suggesting that proper TRPML1 function is essential for the maintenance of lysosomal integrity. In order to investigate whether TRPML2 and TRPML3 also play a role in the maintenance of lysosomal integrity, we conducted gene-specific knockdown assays against these protein targets. Ultrastructural analysis revealed lysosomal inclusions in both TRPML2 and TRPML3 knockdown cells, suggestive of a common mechanism for these proteins, in parallel with TRPML1, in the regulation of lysosomal integrity. However, co-immunoprecipitation assays revealed that physical interactions between each of the e