Relative Liver Protein Research Articles

Study on the mechanism underlying Al-induced hepatotoxicity based on the identification of the Al-binding proteins in liver.

Aluminum (Al) is the most abundant metal element in the earth's crust, and is implicated in the pathogenesis of liver lesions. However, the mechanisms underlying Al3+-induced hepatotoxicity are still largely elusive. Based on analysis with native gel electrophoresis, Al3+ plus 8-hydroxyquinoline staining and LC-MS/MS, the proteins with high Al3+ affinity were identified to be carbamoyl-phosphate synthase, adenosylhomocysteinase, heat shock protein 90-alpha, carbonic anhydrase 3, serum albumin and calreticulin. These proteins are involved in physiological processes such as the urea cycle, redox reactions, apoptosis and so on. Then we established an Al3+-treated rat model for biochemical tests, morphology observation and Ca2+ homeostasis analysis, in order to evaluate the extent of oxidative damage, hepatic histopathology and specific indicators of Al3+-related proteins in liver. Our findings indicated the high-affinity interactions with Al3+ perturbed the normal function of the above proteins, which could account for the mechanism underlying Al3+-induced hepatotoxicity.

Administration of methyl palmitate prevents non-alcoholic steatohepatitis (NASH) by induction of PPAR-α

Background and aimsThe lack of valid therapeutic approach that can ameliorate the manifestations of NASH is a barrier to therapeutic development. Therefore, we investigate the novel role of Methyl Palmitate (MP) in preventing NASH and the possible mechanism involved. Methods50 Male C57BL/6 J mice were randomly divided into 5 groups (n = 10). The control group was fed control diet; model group was fed MCD diet; MP 1 group was fed MCD diet supplemented with MP (75 mg/kg/day); MP 2 group was fed MCD plus MP diet (150 mg/kg/day); and MP 3 group was fed MCD plus MP diet (300 mg/kg/day). Histological staining’s, and commercially available kits for serum ALT and AST and hepatic contents of TG, TC, MDA, SOD, and GSH were used to assess NASH. Furthermore, relative liver protein and gene expression levels were determined by Western Blot and qPCR, respectively. ResultsMice fed MCD diet developed NASH, which was markedly improved by MP in a dose-dependent manner. MP treatment improved hepatic content of TG, TC, MDA, SOD and GSH and serum levels of ALT and AST. In vivo studies showed that MP treatment activated PPARα expression, that in turns, promoted β-oxidation protein and gene expressions, suppressed TNFα, MCP1, TGFβ1 and Colla1 protein and gene expression levels, contributing to the prevention of NASH. ConclusionsOur results indicated that MP could successfully prevent NASH. This effect of MP was mediated through induction of PPARα pathway. This study provides a novel therapeutic target that plays pivotal role in the prevention of NASH.

Novel hepatoprotective role of Leonurine hydrochloride against experimental non-alcoholic steatohepatitis mediated via AMPK/SREBP1 signaling pathway

Background and aimsNon-alcoholic steatohepatitis (NASH) is the hepatic manifestation of metabolic syndrome and is characterized by steatosis, inflammation, and fibrosis. We aim to characterize the hepatoprotective effects of Leonurine hydrochloride (LH) and the possible pathway in a cell and rodent model of diet-induced steatohepatitis (NASH). MethodsFor in vitro studies, Palmitic acid (PA) and free fatty acid (FFA) induced HepG2 and HL7702 steatosis cell models were used. For in vivo studies, NASH was induced by feeding mice MCD diet. These mice received either placebo or LH at three different doses (50、100、200 mg/kg/day) for 6 weeks. Histological staining’s, and commercially available kits for ALT and AST and hepatic contents of TG, TC, MDA, SOD, and GSH were used to assess NASH. Furthermore, relative liver protein and gene expression levels were determined by Western Blot and qPCR, respectively. ResultsAfter establishing NASH models, LH treatment improved lipid accumulation, hepatic contents of TG, TC, and expression levels of ALT and AST in dose-dependent manner. Also, LH improved MDA, SOD, and GSH expression levels. The results of RT-PCR and Western blotting showed that LH upregulated the expression of AMPK phosphorylation and downregulated SREBP-1c and its target genes expression level. ConclusionsOur data reveal the promising role of Leonurine hydrochloride in the prevention and treatment of NASH, in vitro and in vivo. This effect may be partially mediated by the AMPK/SREBP1 pathway. These findings provide a novel therapeutic target for the clinical treatment of NASH.

Identification and Characterization of a cDNA Encoding Cytochrome P450 3A from the Fresh Water Teleost Medaka (Oryzias latipes)

A new member of the CYP3A gene family has been cloned from the teleost fish medaka (Oryzias latipes) by reverse-transcriptase polymerase chain reaction (RT-PCR). Degenerate primers homologous to highly conserved regions of known CYP3A sequences were used for initial RT-PCRs. Individual PCR products were cloned, sequenced, and identified as those belonging to the cytochrome P450 superfamily based on amino acid sequence similarity and the presence of the highly conserved heme-binding region. PCR products were subsequently used as probes to screen a complementary DNA library. A full-length cDNA clone was identified containing a 1758-base-pair (bp) insert with an open reading frame encoding a single peptide of 500 amino acids. Comparisons of the deduced amino acid sequence to other known cytochrome P450 sequences indicate that this gene product is most similar to the CYP3A gene family and has been designated as CYP3A38 by the cytochrome P450 nomenclature committee. Northern blot analysis identified two abundant CYP3A related transcripts in liver of both male and female adults and demonstrated quantitative differences in abundance according to gender. Similarly, Western blot analysis demonstrated the presence of two abundant cytochrome P450 related proteins in liver of both male and female adults. These results suggests that O. latipes contains multiple forms of CYP3A. Heterologous expression of CYP3A38 cDNA in HEK 293 cells produced a single protein that was reactive with anti-scup P450A (CYP3A) polyclonal antibody. Microsomes of HEK 293 cells expressing recombinant CYP3A38 protein actively catalyzed the hydroxylation of testosterone.

Life maintaining activity of delta1 desoxycorticosterone acetate.

SummaryThe steroid Δ1 deoxycorticosterone acetate will maintain adrenalectomized immature rats for 20 days with dosages of 0.25 mg and 0.5 mg and will increase daily body weight 1 and 2 g respectively. Activity is approximately 1/8 to 1/10 that of deoxycorticosterone acetate. Liver water content was unchanged in maintained adrenalectomized rats and the relative liver protein content of adrenalectomized rats receiving Δ1 desoxycorticosterone acetate was comparable to that of normal rats. This steroid did not alter organ weights in normal immature female rats over a 10-day period except for a tendency toward liver weight increase.