AIM To investigate the role of the complement 5a(C5a)/C5 a receptor(C5a R) pathway in the pathogenesis of acute liver failure(ALF) in a mouse model.METHODS BALB/c mice were randomly assigned to different groups, and i...AIM To investigate the role of the complement 5a(C5a)/C5 a receptor(C5a R) pathway in the pathogenesis of acute liver failure(ALF) in a mouse model.METHODS BALB/c mice were randomly assigned to different groups, and intraperitoneal injections of lipopolysaccharide(LPS)/D-galactosamine(D-Gal N)(600 mg/kg and 10 μg/kg) were used to induce ALF. The KaplanMeier method was used for survival analysis. Serum alanine aminotransferase(ALT) levels, at different time points within a 1-wk period, were detected with a biochemistry analyzer. Pathological examination of liver tissue was performed 36 h after ALF induction. Serum complement 5(C5), C5 a, tumor necrosis factor-α(TNF-α), interleukin(IL)-1β, IL-6, high-mobility group protein B1(HMGB1) and sphingosine-1-phosphatelevels were detected by enzyme-linked immunosorbant assay. Hepatic morphological changes at 36 h after ALF induction were assessed by hematoxylin and eosin staining. Expression of C5 a R, sphingosine kinase 1(Sph K1), p38-MAPK and p-p38-MAPK in liver tissue, peripheral blood mononuclear cells(PBMCs) and peritoneal exudative macrophages(PEMs) of mice or RAW 264.7 cells was analyzed by western blotting. C5 a R m RNA levels were detected by quantitative real-time PCR.RESULTS Activation of C5 and up-regulation of C5 a R were observed in liver tissue and PBMCs of mice with ALF. Blockade of C5 a R with a C5 a R antagonist(C5a Ra C5 a Ra) significantly reduced the levels of serum ALT, inflammatory cytokines(TNF-α, IL-1β and IL-6) and HMGB1, as well as the liver tissue damage, but increased the survival rates(P < 0.01 for all). Blockade of C5 a R decreased Sph K1 expression in both liver tissue and PBMCs significantly at 0.5 h after ALF induction. C5 a Ra pretreatment significantly downregulated the phosphorylation of p38-MAPK in liver tissues of ALF mice and C5 a stimulated PEMs or RAW 264.7 cells. Moreover, inhibition of p38-MAPK activity with SB203580 reduced Sph K1 protein production significantly in PEMs after C5 a stimulation.CONCLUSION The C5a/C5 a R pathway is essential for up-regulating Sph K1 expression through p38 MAPK activation in ALF in mice, which provides a potential immunotherapeutic strategy for ALF in patients.展开更多
A radio frequency (r.f.) ion source used in the electrostatic accelerator was designed and built for the study on the ion beam bioengineering. The extracting characteristics were determined by experiments, from whic...A radio frequency (r.f.) ion source used in the electrostatic accelerator was designed and built for the study on the ion beam bioengineering. The extracting characteristics were determined by experiments, from which the results showed that a maximal beam current is obtained under the condition of the extracting voltage 1700V and the gas pressure in the range of (4~ 8)× 10-4 Pa. And the diameter of the ion beam was measured as well.展开更多
Aging-elevated DNMT3A R882H-driven clonal hematopoiesis(CH)is a risk factor for myeloid malignancies remission and overall survival.Although some studies were conducted to investigate this phenomenon,the exact mechani...Aging-elevated DNMT3A R882H-driven clonal hematopoiesis(CH)is a risk factor for myeloid malignancies remission and overall survival.Although some studies were conducted to investigate this phenomenon,the exact mechanism is still under debate.In this study,we observed that DNMT3 A R878 H bone marrow cells(human allele:DNMT3 A R882 H)displayed enhanced reconstitution capacity in aged bone marrow milieu and upon inflammatory insult.DNMT3 A R878 H protects hematopoietic stem and progenitor cells from the damage induced by chronic inflammation,especially TNFa insults.Mechanistically,we identified that RIPK1-RIPK3-MLKL-mediated necroptosis signaling was compromised in R878 H cells in response to proliferation stress and TNFa insults.Briefly,we elucidated the molecular mechanism driving DNMT3 A R878 H-based clonal hematopoiesis,which raises clinical value for treating DNMT3 A R882 H-driven clonal hematopoiesis and myeloid malignancies with aging.展开更多
基金Supported by the National Natural Science Foundation of China,No.81260455 and No.81160065
文摘AIM To investigate the role of the complement 5a(C5a)/C5 a receptor(C5a R) pathway in the pathogenesis of acute liver failure(ALF) in a mouse model.METHODS BALB/c mice were randomly assigned to different groups, and intraperitoneal injections of lipopolysaccharide(LPS)/D-galactosamine(D-Gal N)(600 mg/kg and 10 μg/kg) were used to induce ALF. The KaplanMeier method was used for survival analysis. Serum alanine aminotransferase(ALT) levels, at different time points within a 1-wk period, were detected with a biochemistry analyzer. Pathological examination of liver tissue was performed 36 h after ALF induction. Serum complement 5(C5), C5 a, tumor necrosis factor-α(TNF-α), interleukin(IL)-1β, IL-6, high-mobility group protein B1(HMGB1) and sphingosine-1-phosphatelevels were detected by enzyme-linked immunosorbant assay. Hepatic morphological changes at 36 h after ALF induction were assessed by hematoxylin and eosin staining. Expression of C5 a R, sphingosine kinase 1(Sph K1), p38-MAPK and p-p38-MAPK in liver tissue, peripheral blood mononuclear cells(PBMCs) and peritoneal exudative macrophages(PEMs) of mice or RAW 264.7 cells was analyzed by western blotting. C5 a R m RNA levels were detected by quantitative real-time PCR.RESULTS Activation of C5 and up-regulation of C5 a R were observed in liver tissue and PBMCs of mice with ALF. Blockade of C5 a R with a C5 a R antagonist(C5a Ra C5 a Ra) significantly reduced the levels of serum ALT, inflammatory cytokines(TNF-α, IL-1β and IL-6) and HMGB1, as well as the liver tissue damage, but increased the survival rates(P < 0.01 for all). Blockade of C5 a R decreased Sph K1 expression in both liver tissue and PBMCs significantly at 0.5 h after ALF induction. C5 a Ra pretreatment significantly downregulated the phosphorylation of p38-MAPK in liver tissues of ALF mice and C5 a stimulated PEMs or RAW 264.7 cells. Moreover, inhibition of p38-MAPK activity with SB203580 reduced Sph K1 protein production significantly in PEMs after C5 a stimulation.CONCLUSION The C5a/C5 a R pathway is essential for up-regulating Sph K1 expression through p38 MAPK activation in ALF in mice, which provides a potential immunotherapeutic strategy for ALF in patients.
文摘A radio frequency (r.f.) ion source used in the electrostatic accelerator was designed and built for the study on the ion beam bioengineering. The extracting characteristics were determined by experiments, from which the results showed that a maximal beam current is obtained under the condition of the extracting voltage 1700V and the gas pressure in the range of (4~ 8)× 10-4 Pa. And the diameter of the ion beam was measured as well.
基金the Beijing Advanced Innovation Center for Structural Biology and the Tsinghua-Peking Center for Life Sciences for facility and financial supportsupported by grant numbers 2018YFA0800200,2017YFA0104000,91849106,Z200022,Z181100001818005 and 81870118 to Jianwei Wang from the National Key R&D Program of China or the Beijing Municipal Science&Technology Commission and the National Natural Science Foundation of China。
文摘Aging-elevated DNMT3A R882H-driven clonal hematopoiesis(CH)is a risk factor for myeloid malignancies remission and overall survival.Although some studies were conducted to investigate this phenomenon,the exact mechanism is still under debate.In this study,we observed that DNMT3 A R878 H bone marrow cells(human allele:DNMT3 A R882 H)displayed enhanced reconstitution capacity in aged bone marrow milieu and upon inflammatory insult.DNMT3 A R878 H protects hematopoietic stem and progenitor cells from the damage induced by chronic inflammation,especially TNFa insults.Mechanistically,we identified that RIPK1-RIPK3-MLKL-mediated necroptosis signaling was compromised in R878 H cells in response to proliferation stress and TNFa insults.Briefly,we elucidated the molecular mechanism driving DNMT3 A R878 H-based clonal hematopoiesis,which raises clinical value for treating DNMT3 A R882 H-driven clonal hematopoiesis and myeloid malignancies with aging.
