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Hepatic fibrosis （HF） is a pathological process of abnormal repair of liver tissue structure caused by chronic liver injury， and its pathogenesis has not been fully clarified. Related studies have shown that programmed cell death may be associated with the onset of HF， and traditional Chinese medicine （TCM） has a significant effect in regulating programmed cell death to intervene against HF. This article reviews the main mechanism of the influence of programmed cell death on HF and discusses the possible mechanism of TCM regulation of programmed cell death in improving HF， which provides new ideas for TCM prevention and treatment of HF.
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Sphingomyelinases (SMase) are the main enzymes that regulate the signaling pathway of sphingomyelin and the metabolism of related products, and they are involved in the key steps of the complex metabolic process of sphingomyelin. In recent years, many studies have shown that SMase is involved in the biological processes such as cell cycle arrest, cell migration, and inflammation and promotes the development and progression of hepatocellular carcinoma by regulating the apoptosis and proliferation of tumor stem cells. SMase has an important potential biological value in the development, progression, diagnosis, and treatment of hepatocellular carcinoma. This article summarizes the exact role of SMase in the development and progression of hepatocellular carcinoma, in order to provide new ideas and strategies for the clinical treatment of hepatocellular carcinoma and the development of new drugs.
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The influence of different affinity tags on enzyme characteristics varies. The (S)-carbonyl reductase 2 (SCR2) from Candida parapsilosis can reduce 2-hydroxyacetophenone, which is a valuable prochiral ketones. Different affinity tags, i.e. his-tag, strep-tag and MBP-tag, were attached to the N terminus of SCR2. These tagged SCR2 enzymes, i.e. his6-SCR2, strep-SCR2 and MBP-SCR2, were heterologously expressed in Escherichia coli and purified to study their characteristics towards 2-hydroxyacetophenone reduction. Affinity tags did affect the characteristics of the recombinant SCR2 enzymes. Specifically, affinity tags affect the stability of recombinant SCR2 enzymes: 1) At pH 6.0, the remaining enzyme activities of his6-SCR2 and strep-SCR2 were only 95.2% and 90.0% of the untagged SCR2, while that of MBP-SCR2 was 1.2 times of the untagged SCR2 after incubating for 13 h at 30 °C. 2) The half-life of MBP-SCR2 at 50 °C was 26.6%-48.8% longer than those of strep-SCR2, his6-SCR2 and untagged SCR2. 3) The kcat of MBP-SCR2 was about 1.25-1.45 times of that of small affinity-tagged and untagged SCR2 after storing at -80 °C for 60 d. Structural informatics indicated that the α-helices at the C terminus of MBP-SCR2 contributed to the stability of the N terminus of fusion protein of SCR2. Data from circular dichroism showed that the MBP-tag has some influence on the secondary structure of SCR2, while melting temperature analysis demonstrated that the Tm of the recombinant MBP-SCR2 was about 5 °C higher than that of the untagged SCR2. This study obtained an efficient and stable recombinant SCR2, i.e. the MBP-SCR2. Moreover, this study could serve as a reference for other researchers to evaluate and select appropriate affinity tags for their research.
Subject(s)
Alcohol Oxidoreductases , Escherichia coli/genetics , Recombinant Fusion Proteins/geneticsABSTRACT
Acute-on-chronic liver failure (ACLF) is a life-threatening disease with a high risk of multiple organ failure, sepsis, and death. ACLF activates innate and acquired immune responses in human body and thus leads to the progression of persistent systemic inflammatory response syndrome and multiple organ dysfunction, leading to the high mortality rate of this disease. Dysregulated immune response plays a key role in disease progression, and immunotherapy may help to target immune-mediated organ damage and inhibit the progression of liver failure. This article reviews the role and mechanism of drugs and means with a potential immune regulatory effect in ACLF, in order to provide a reference for immunotherapy for ACLF.
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The incidence rate of nonalcoholic fatty liver disease (NAFLD) is increasing. Diet is considered one of the main driving forces regulating the composition of intestinal microbiota, and the intestine and the liver are closely linked through the portal vein, so changes in gut microbiota may affect liver function and promote inflammation, insulin resistance, and steatosis, thereby causing NAFLD. This article elaborates on the relationship between diet, gut microbiota, and the liver and the research advances in how this axis promotes the progression of NAFLD, as well as the change in potential mechanism due to intestinal dysbacteriosis and related treatment methods.
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Absent in melanoma 2 (AIM2) is a cytoplasmic double-stranded DNA (dsDNA) sensing protein that can recognize the dsDNA released during cell disturbance and pathogen invasion and trigger the activation of inflammasome cascade. Activation of inflammasomes leads to the maturation and release of inflammatory cytokines (interleukin-1β and interleukin-18), induces pyroptosis, and initiate innate immune response. Among these inflammasomes, AIM2 and its mechanism of action and clinical significance in liver diseases has become a research hotspot at present. This article summarizes and discusses the importance of AIM2 in the pathogenesis of various liver diseases including nonalcoholic fatty liver disease, hepatitis B virus infection, liver fibrosis, liver cirrhosis, and hepatocellular carcinoma, so as to provide new ideas and a reference for clinical treatment.
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Absent in melanoma 2 (AIM2) is a cytoplasmic double-stranded DNA (dsDNA) sensing protein that can recognize the dsDNA released during cell disturbance and pathogen invasion and trigger the activation of inflammasome cascade. Activation of inflammasomes leads to the maturation and release of inflammatory cytokines (interleukin-1β and interleukin-18), induces pyroptosis, and initiate innate immune response. Among these inflammasomes, AIM2 and its mechanism of action and clinical significance in liver diseases has become a research hotspot at present. This article summarizes and discusses the importance of AIM2 in the pathogenesis of various liver diseases including nonalcoholic fatty liver disease, hepatitis B virus infection, liver fibrosis, liver cirrhosis, and hepatocellular carcinoma, so as to provide new ideas and a reference for clinical treatment.
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Liver failure is a syndrome of severe liver diseases commonly seen in clinical practice, and it has a high mortality rate and thus becomes one of the critical diseases in internal medicine. Massive hepatocyte death and the extent of hepatocyte death exceeding the liver’s regenerative capacity are considered the core events in the development and progression of liver failure, and direct injury and immune-mediated inflammatory injury are the two main factors in this process. An increasing number of evidence has shown that host immune response and inflammatory cascade play an important role in the pathogenesis of liver failure. This article reviews the mechanism of action of immunoregulation (congenital and adaptive) and inflammatory injury (inflammation inducers, receptor cells, and inflammatory mediators) in the process of hepatic failure, as well as the interactions between immune response and immune cells and between inflammatory response and inflammatory factors, in order to help understand the pathogenesis of liver failure and provide new ideas for the diagnosis and treatment of liver failure and drug research and development.
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Arginine deiminase (ADI) was first high-efficient expressed in Corynebacterium crenatum SYPA 5-5. The ADI was purified by Ni-NTA affinity chromatography and SDS-PAGE analysis showed the molecular weight (MW) was 46.8 kDa. The optimal temperature and pH of ADI were 37 ℃ and 6.5 respectively. The Michaelis constant was 12.18 mmol/L and the maximum velocity was 0.36 μmol/(min·mL). Under optimal conditions, 300 g/L of arginine was transformed and the productivity reach 8 g/(L·h). The recombinant strain was cultivated in a 5-L fermentor and used for whole-cell transformation of 300 g/L arginine, under repeated-batch bioconversion, the cumulative production reached 1 900 g/L.
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Objective To describe the prevalence and risk factors of insomnia among adults in YiBin City. Meth?ods Using multi-stage stratified cluster sampling, 12000 subjects over 18 years old were identified in YiBin City. The subjects were screened using the insomnia survey self-edited and risk factors of insomnia were identified through logistic analysis. Results A total of 11227 subjects completed the survey in which 1671 people (14.9%, 95%CI:14.2%~15.5%) were diagnosed insomnia using ICD-10. Among them, 9.4% (157 patients) had seeked for professional help. The multi?variate logistic analysis showed that low level of life quality(OR=2.42,P<0.01), jobless(OR=1.87,P<0.01), over 60 years old(OR=1.69,P<0.01), fewer years of education(OR=1.41,P<0.01), female(OR=1.41,P<0.01)and lower annu?al per capita income(OR=1.15,P=0.01)were risk factors in insomnia people. Conclusion The incidence of insomnia is high in YiBin city. Sleep quality in high-risk group needs more attention and corresponding measures should be taken in order to increase the rate of asking for help in insomnia people.
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To improve the expression level and catalytic efficiency of (R)-carbonyl reductase from Candida parapsilosis in Escherichia coli, we optimized the mRNA secondary structure of (R)-carbonyl reductase gene in translation initiation region (from +1 to +78), and constructed the corresponding variant. The formation of hairpin structure was significantly reduced and the Gibbs free energy was dramatically decreased from -9.5 kcal/mol to -5.0 kcal/mol after optimization. As a result, the expression level of (R)-carbonyl reductase in the variant was increased by 4-5 times and its specific activity in cell-free extract was enhanced by 61.9% compared to the wild-type strain. When using the whole cells as catalyst and 2-hydroxyacetophenone as substrate with a high concentration of 5.0 g/L, the variant showed excellent performance to give (R)-1-phenyl-1, 2-ethanediol with optical purity of 93.1% enantiomeric excess and a yield of 81.8%, which were increased by 27.5% and 40.5% respectively than those of the wild-type. In conclusion, the optimization of mRNA secondary structure in translation initiation region can overcome the steric hindrance of translation startup, promote translation smoothly to acquire high expression of target protein, and favor protein folding correctly to efficiently improve the enzyme specific activity and biotransformation function.
Subject(s)
Alcohol Oxidoreductases , Chemistry , Genetics , Base Sequence , Biocatalysis , Candida , Catalysis , Escherichia coli , Genetics , Metabolism , Molecular Sequence Data , Mutant Proteins , Genetics , Nucleic Acid Conformation , Peptide Chain Initiation, Translational , RNA, Messenger , Chemistry , Recombinant Proteins , Genetics , StereoisomerismABSTRACT
Objective To evaluate the therapeutic effects of trabeculectomy through two right angle incisions.Methods Trabeculectomy was performed on 23 cases (25 eyes)through two right angle incisions.Results All operated eyes formed functional fistulizing blebs and their intraocular pressure were nomal in the follow up periods of 3～10 months.Conclusion The trabeculectomy through two right angle incisions is better than traditional trabeculectomy and similar to clear-cornea trabeculectomy with the merits of simplicity and fewer complications.