Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.22.60 (caspase-7)
 920 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fatty liver disease has become a health problem related to metabolic syndrome worldwide, although its molecular pathogenesis requires further study. It is also unclear whether advanced fibrosis of steatohepatitis will regress when diet is controlled. The aim of this study was to investigate whether the resolution of fibrosis occurs in steatohepatitis induced by a methionine-choline-deficient diet (MCDD). Manifestation of endoplasmic reticulum (ER) stress in this model was also studied. Nonalcoholic steatohepatitis with advanced fibrosis was induced in rats by feeding them an MCDD for 10 weeks. Instead of MCDD, a methionine-choline control diet (CD) was given for the last 2 weeks to the experimental group. Fibrosis and inflammation were determined by tissue staining. Protein and gene expressions were determined by immunoblotting and quantitative reverse transcription-PCR (RT-PCR), respectively. Expressions of caspase-7, caspase-12, glucose-regulated protein 78 (GRP78), and protein disulfide isomerase were evaluated to clarify the presence of ER stress. Changing the diet from MCDD to CD triggered the reduction of fat in hepatocytes, a decrease in inflammatory gene expression and oxidative stress, and regression of fibrosis accompanied by the disappearance of activated stellate cells and macrophages. Immunohistochemistry, immunoblotting, and RT-PCR analysis all indicated the occurrence of ER stress in steatohepatitis, while it recovered immediately after changing the diet from MCCD to CD. The ratio of hepatocyte proliferation/apoptotis increased significantly during the recovery stage. This simple experiment clearly shows that changing the diet from MCDD to a normal diet (CD) triggers the resolution of hepatic inflammatory and fibrotic reactions and hepatocyte apoptosis, suggesting that MCDD-induced steatohepatitis is also reversible. ER stress appears and disappears in association with the generation and regression of steatohepatitis, respectively, with fibrosis.
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PMID:Reversibility of fibrosis, inflammation, and endoplasmic reticulum stress in the liver of rats fed a methionine-choline-deficient diet. 1994 75

Nonalcoholic steatohepatitis with fibrosis is a more severe form of nonalcoholic fatty liver disease, one of the most common liver diseases. We have previously shown that peroxisome proliferator-activated receptors gamma (PPARgamma) ligand, rosiglitazone, prevented the development of the methionine choline deficient (MCD) diet-induced fibrosing steatohepatitis. We have now tested whether overexpression of PPARgamma ameliorates established steatohepatitis and fibrosis. Male C57BL6 mice fed with MCD diet for 8 weeks developed hepatic fibrosis with increased hepatic expression of collagen1alpha(I), inhibitors of fibrosis reversal-1, regulator involved in matrix degradation-9 and connective tissue growth factor. After 2 weeks of transduction of PPARgamma through an adenovirus-expressing PPARgamma (Ad-PPARgamma), expression of these genes was reduced in a manner that paralleled the reduction in activated hepatic stellate cells (HSCs) and resolution of liver fibrosis. On the in vitro study, PPARgamma is expressed in primary quiescent HSC, but depleted in culture activated HSC. Conversely, ectopic expression of PPARgamma in activated HSC achieved the phenotypic reversal to the quiescent cell. Such induction markedly suppressed cell viability and cell proliferation, downregulated proliferating cell nuclear antigen, and caused cell cycle arrest at G0/G1 phase. Further, introduction of PPARgamma in HSC increased cell apoptosis, this was confirmed by enhanced expression of FasL, cleaved caspase-3, cleaved caspase-7 and poly ADP-ribose polymerase, indicating an extrinsic apoptosis pathway. In conclusion, the present study shows that MCD diet-induced fibrosing steatohepatitis can be reversed by overexpression of PPARgamma. It is likely that PPARgamma reverses fibrosis by reducing HSCs proliferation, inducing cell cycle arrest and apoptosis.
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PMID:Peroxisome proliferator-activated receptors gamma reverses hepatic nutritional fibrosis in mice and suppresses activation of hepatic stellate cells in vitro. 2015 80

Designed ankyrin repeat proteins (DARPins) are well-established binding molecules based on a highly stable nonantibody scaffold. Building on 13 crystal structures of DARPin-target complexes and stability measurements of DARPin mutants, we have generated a new DARPin library containing an extended randomized surface. To counteract the enrichment of unspecific hydrophobic binders during selections against difficult targets containing hydrophobic surfaces such as membrane proteins, the frequency of apolar residues at diversified positions was drastically reduced and substituted by an increased number of tyrosines. Ribosome display selections against two human caspases and membrane transporter AcrB yielded highly enriched pools of unique and strong DARPin binders which were mainly monomeric. We noted a prominent enrichment of tryptophan residues during binder selections. A crystal structure of a representative of this library in complex with caspase-7 visualizes the key roles of both tryptophans and tyrosines in providing target contacts. These aromatic and polar side chains thus substitute the apolar residues valine, leucine, isoleucine, methionine, and phenylalanine of the original DARPins. Our work describes biophysical and structural analyses required to extend existing binder scaffolds and simplifies an existing protocol for the assembly of highly diverse synthetic binder libraries.
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PMID:Design, construction, and characterization of a second-generation DARP in library with reduced hydrophobicity. 2386 33