Characteristics of amino acid metabolism in myeloid-derived suppressor cells in septic mice / 北京大学学报(医学版)

OBJECTIVE@#To explore the amino acid metabolomics characteristics of myeloid-derived suppressor cells (MDSCs) in mice with sepsis induced by the cecal ligation and puncture (CLP).@*METHODS@#The sepsis mouse model was prepared by CLP, and the mice were randomly divided into a sham operation group (sham group, n = 10) and a CLP model group (n = 10). On the 7th day after the operation, 5 mice were randomly selected from the surviving mice in each group, and the bone marrow MDSCs of the mice were isolated. Bone marrow MDSCs were separated to measure the oxygen consumption rate (OCR) by using Agilent Seahorse XF technology and to detect the contents of intracellular amino acids and oligopeptides through ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) technology. Different metabolites and potential biomarkers were analyzed by univariate statistical analysis and multivariate statistical analysis. The major metabolic pathways were enriched using the small molecular pathway database (SMPDB).@*RESULTS@#The proportion of MDSCs in the bone marrow of CLP group mice (75.53% ± 6.02%) was significantly greater than that of the sham group (43.15%± 7.42%, t = 7.582, P < 0.001), and the basal respiratory rate [(50.03±1.20) pmol/min], maximum respiration rate [(78.07±2.57) pmol/min] and adenosine triphosphate (ATP) production [(25.30±1.21) pmol/min] of MDSCs in the bone marrow of CLP group mice were significantly greater than the basal respiration rate [(34.53±0.96) pmol/min, (t = 17.41, P < 0.001)], maximum respiration rate [(42.57±1.87) pmol/min, (t = 19.33, P < 0.001)], and ATP production [(12.63±0.96) pmol/min, (t = 14.18, P < 0.001)] of sham group. Leucine, threonine, glycine, etc. were potential biomarkers of septic MDSCs (all P < 0.05). The increased amino acids were mainly enriched in metabolic pathways, such as malate-aspartate shuttle, ammonia recovery, alanine metabolism, glutathione metabolism, phenylalanine and tyrosine metabolism, urea cycle, glycine and serine metabolism, β-alanine metabolism, glutamate metabolism, arginine and proline metabolism.@*CONCLUSION@#The enhanced mitochondrial oxidative phosphorylation, malate-aspartate shuttle and alanine metabolism in MDSCs of CLP mice may provide raw materials for mitochondrial aerobic respiration, thereby promoting the immunosuppressive function of MDSCs. Blocking the above metabolic pathways may reduce the risk of secondary infection in sepsis and improve the prognosis.

Protective Effect and Mechanism of Buzhong Yiqitang on Concanavalin A-induced Acute Liver Failure in Mice / 中国实验方剂学杂志

<b>Objective::To explore the hepatoprotective effect and the mechanism of Buzhong Yiqitang (BZYQT) on mice with acute liver failure induced by Concanavalin A (ConA). <b>Method::A total of 80 mice were randomly divided into normal group, model group, Cyclosporine A (CsA) group, BZYQT low and high dose group (10.5, 21 g·kg^-1), 16 mice per group. All the mice except for normal group were injected intravenously with 15 mg·kg^-1 ConA. The treatment group mice were orally administrated with BZYQT, or intravenously administrated with 50 mg·kg^-1 CsA 30 min post ConA injection, normal and model group mice were orally administrated with ddH₂O at the same time. Blood, liver and spleen were collected 3 and 10 h post ConA injection. Cytokine levels of tumor necrosis factor alpha (TNF-<italic>α</italic>), interleukin-6 (IL-6), interleukin-12 (IL-12), interferon-gamma (IFN-<italic>γ</italic>) and monocyte chemoattractant protein-1 (MCP-1) in the serum were detected with cytometric bead array. The alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels in the serum were analyzed with fully automatic biochemical analyzer. The pathological changes of liver tissues were observed by hematoxylin-eosin (HE) staining. The activation of splenic CD4⁺ T lymphocytes was analyzed by flow cytometry. The expression and phosphorylation of extracellular regulated protein kinase 1/2(ERK1/2) and p38 mitogen-activated protein kinase (p38 MAPK) was analyzed by Western blot. <b>Result::Compared with normal group, model group showed higher levels of ALT and AST in the serum (<italic>P</italic><0.01), obvious pathological damage of liver tissue, higher levels of TNF-<italic>α</italic>, IL-6, IL-12, IFN-<italic>γ</italic> and MCP-1 in the serum (<italic>P</italic><0.01), higher expression of IL-2, IFN-<italic>γ</italic> and IL-4 CD4⁺ T lymphocytes in the spleen (<italic>P</italic><0.01), and elevated levels of phosphorylation of ERK1/2 and p38 MAPK (<italic>P</italic><0.01). Compared with the model group, BZYQT high dose group showed decreased levels of ALT and AST (<italic>P</italic>< 0.05, <italic>P</italic><0.01), reduced liver injury, decreased levels of TNF-<italic>α</italic>, IL-6, IL-12, IFN-<italic>γ</italic> and MCP-1 in the serum (<italic>P</italic><0.05, <italic>P</italic><0.01), reduced level of IL-2 and IFN-<italic>γ</italic> CD4⁺ T lymphocytes in the spleen (<italic>P</italic><0.05, <italic>P</italic><0.01), and reduced levels of phosphorylation of ERK1/2 and p38 MAPK (<italic>P</italic><0.05, <italic>P</italic><0.01). <b>Conclusion::BZYQT has a protective effect on mice with acute liver failure induced by ConA. The mechanism may be through inhibiting ERK1/2 and p38 MAPK signaling pathways, thereby reducing T lymphocyte activation and inflammatory cytokine secretion.

Xijiao Dihuang Decoction () and Rehmannia glutinosa Libosch. protect mice against lipopolysaccharide and tumor necrosis factor alpha-induced acute liver failure / 中国结合医学杂志

OBJECTIVE@#To investigate the hepatoprotective effect of Xijiao Dihuang Decoction (, XJDHD) on lipopolysaccharide (LPS)- and tumor necrosis factor alpha (TNF-α)-induced acute liver failure (ALF) as well as the underlying mechanism of action, and to clarify the key herbs and components of XJDHD.@*METHODS@#LPS/D-galactosamine (D-GalN) or TNF-α/D-GalN were intraperitoneally injected into C57BL/6J mice to induce ALF. Simultaneously, XJDHD or its individual herbs and components were orally administered. Survival rates, transaminase levels in serum, and hepatic histology were examined to evaluate the effects of XJDHD. The terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay and real-time polymerase chain reaction were additionally performed to expound the mechanism underlying the anti-apoptotic activity of XJDHD.@*RESULTS@#Oral administration of XJDHD protected mice from lethal liver failure induced by LPS and TNF-α, with notable amelioration of liver injury in histology and a significant decrease in transaminase levels in serum. XJDHD significantly inhibited apoptosis of hepatocytes and enhanced expression of the antiapoptosis genes, c-Flip, Iap1, Gadd45b and A20. In addition, Rehmannia glutinosa Libosch. was identified as the key herb of XJDHD and galactose as the effective component of Rehmannia glutinosa Libosch. that protects against ALF.@*CONCLUSIONS@#XJDHD inhibits TNF-α-induced apoptosis of hepatocytes by promoting the expression of nuclear factor κ B-regulated anti-apoptotic genes. Rehmannia glutinosa Libosch. is the effective herb of XJDHD and galactose is an active component in this protection.

A second protein marker of caveolae: caveolin-2 / 中国医学科学杂志(英文版)

Caveolin-2, a protein about 20 kD, is a major component of the inner surface of caveolae, small invaginations of the plasma membrane. Similar with caveolin-1 and caveolin-3, it serves as a protein marker of caveolae. Caveolin-1 and -2 are located next to each other at 7q31.1 on human chromosome, the proteins encoded are co-localized and form a stable hetero-oligomeric complex, distributing similarly in tissue and cultured cells. Caveolin-3 is located on different chromosomes but confirmed to interact with caveolin-2. Caveolin-2 is similar to caveolin-1 in many respects but differs from the latter in functional domains, especially in G-protein binding domain and caveolin scaffolding domain. The mRNAs of both caveolin-1 and caveolin-2 are most abundantly expressed in white adipose tissue and are induced during differentiation of 3T3-L1 cells to adipocytes. Caveolin-2-deficient mice demonstrate clear pulmonary defects, with little or no change in caveolin-1 expression and caveolae formation, suggesting that caveolin-2 plays a selective role in lung functions. Caveolin-2 is also involved in lipid metabolism and human cancers.

Research advances in Sirt1 gene / 中国医学科学院学报

As the most homologic homologue of silent information regulator 2 of yeast, Sirt1 gene is extensively expressed in mature tissues, and is rich in early embryo and reproductive cells. It is involved in the regulation of gene transcription, energy metabolism and cell aging. It promotes fat mobilization in adipocytes and glucose production in liver and regulates insulin secretion in islet beta cell. Furthermore, Sirt1 gene is an essential endogenous apoptosis inhibitor. In future, it may be used as new drug targets or applied in other disease management modalities.

Current situation researching of methylation in tumor / 中国医学科学院学报

The disorders of DNA and histone methylation have a close relationship with the development and progression of tumors. Epigenetic regulation is critical in maintaining the stability and integrity of the expression profiles of different cell types by modifying DNA methylation and histone methylation. However, the abnormal changes of methylation often result in the development and progression of tumors. This review summarized the theory of tumor genomic and histone methylation, detection methods of methylation and their applications, and the clinical application of methylation as biological markers and drug targets.