We reported in this manuscript that TGF-beta1 induces apoptosis in AML12 murine hepatocytes, which is associated with the activation of p38 MAPK signaling pathway. SB202190, a specific inhibitor of p38 MAPK, strongly ...We reported in this manuscript that TGF-beta1 induces apoptosis in AML12 murine hepatocytes, which is associated with the activation of p38 MAPK signaling pathway. SB202190, a specific inhibitor of p38 MAPK, strongly inhibited the TGF-beta1-induced apoptosis and PAI-1 promoter activity. Treatment of cells with TGF-beta1 activates p38. Furthermore, over-expression of dominant negative mutant p38 also reduced the TGF-beta1-induced apoptosis. The data indicate that the activation of p38 is involved in TGF-beta1-mediated gene expression and apoptosis.展开更多
Background:Skin wound healing depends on the progress of different but overlapping stages of healing,including hemostasis,inflammatory,proliferative and remodeling.Failure of these stages to occur in a timely and grad...Background:Skin wound healing depends on the progress of different but overlapping stages of healing,including hemostasis,inflammatory,proliferative and remodeling.Failure of these stages to occur in a timely and gradual manner may result in non-healing pathological wounds.Macrophages and neutrophils have been shown to play an essential role in the inflammatory responses of wound tissue,and their active plasticity allows them to modulate tissue damage and repair functions.The ability of macrophages and neutrophils to regulate the occurrence and resolution of inflammatory processes is essential for the treatment of pathological wound healing.Methods:Mice were categorized into negative control,streptozotocin,streptozotocin+puerarin and puerarin groups.The traditional Chinese medicine extract puerarin was selected to treat different groups of mice with a full-thickness skin defect wound.Cells of the RAW264.7 cell line were stimulated under different puerarin conditions.Then,real time quantitative polymerase chain reaction(RT-qPCR),western blot,immunofluorescence and other assays were carried out to explore the effect of puerarin on wound healing and its molecular mechanism.Results:Animal experiments found that the wound healing of diabetic mice treated with puerarin was significantly accelerated,and histological analysis found that puerarin treatment markedly decreased the infiltration of macrophages and neutrophils in wound tissue.Through western blot,RT-qPCR and immunofluorescence experiments,it was observed that puerarin treatment remarkably inhibited nuclear factor kinase B(NF-κB)and mitogen-activated protein kinase(MAPK)signaling pathways,downregulated the expression of inflammatory cytokines and induced the M2 polarization of macrophages.At the cellular level,we also observed that puerarin improved M2 macrophage polarization and inhibited inflammatory pathway activation in a high-glucose culture.Conclusion:Puerarin has a significant therapeutic effect on wound healing in diabetic mice.The therapeutic effect is achieved by regulating macrophage polarization through suppressing NF-κB and MAPK signaling cascades.展开更多
Background:Gastric cancer(GC)is one of the most common malignancies worldwide,particularly in China.DNA damage-inducible transcript 4(DDIT4)is a mammalian target of rapamycin inhibitor and is induced by various cellul...Background:Gastric cancer(GC)is one of the most common malignancies worldwide,particularly in China.DNA damage-inducible transcript 4(DDIT4)is a mammalian target of rapamycin inhibitor and is induced by various cellular stresses;however,its critical role in GC remains poorly understood.The present study aimed to investigate the poten-tial relationship and the underlying mechanism between DDIT4 and GC development.Methods:We used western blotting,real-time polymerase chain reaction,and immunohistochemical or immunoflu-orescence to determine DDIT4 expression in GC cells and tissues.High-content screening,cell counting kit-8 assays,colony formation,and in vivo tumorigenesis assays were performed to evaluate cell proliferation.Flow cytometry was used to investigate cell apoptosis and cell cycle distribution.Results:DDIT4 was upregulated in GC cells and tissue.Furthermore,downregulating DDIT4 in GC cells inhibited proliferation both in vitro and in vivo and increased 5-fluorouracil-induced apoptosis and cell cycle arrest.In contrast,ectopic expression of DDIT4 in normal gastric epithelial cells promoted proliferation and attenuated chemosensitivity.Further analysis indicated that the mitogen-activated protein kinase and p53 signaling pathways were involved in the suppression of proliferation,and increased chemosensitivity upon DDIT4 downregulation.Conclusion:DDIT4 promotes GC proliferation and tumorigenesis,providing new insights into the role of DDIT4 in the tumorigenesis of human GC.展开更多
基金grants fromthe Chinese Academy of Sciences (No. KJ951-BI608), the National Natural Sciences FOundation ofChina (No. 39625007 and
文摘We reported in this manuscript that TGF-beta1 induces apoptosis in AML12 murine hepatocytes, which is associated with the activation of p38 MAPK signaling pathway. SB202190, a specific inhibitor of p38 MAPK, strongly inhibited the TGF-beta1-induced apoptosis and PAI-1 promoter activity. Treatment of cells with TGF-beta1 activates p38. Furthermore, over-expression of dominant negative mutant p38 also reduced the TGF-beta1-induced apoptosis. The data indicate that the activation of p38 is involved in TGF-beta1-mediated gene expression and apoptosis.
基金supported by The National Natural Science Foundation of China(81974288).
文摘Background:Skin wound healing depends on the progress of different but overlapping stages of healing,including hemostasis,inflammatory,proliferative and remodeling.Failure of these stages to occur in a timely and gradual manner may result in non-healing pathological wounds.Macrophages and neutrophils have been shown to play an essential role in the inflammatory responses of wound tissue,and their active plasticity allows them to modulate tissue damage and repair functions.The ability of macrophages and neutrophils to regulate the occurrence and resolution of inflammatory processes is essential for the treatment of pathological wound healing.Methods:Mice were categorized into negative control,streptozotocin,streptozotocin+puerarin and puerarin groups.The traditional Chinese medicine extract puerarin was selected to treat different groups of mice with a full-thickness skin defect wound.Cells of the RAW264.7 cell line were stimulated under different puerarin conditions.Then,real time quantitative polymerase chain reaction(RT-qPCR),western blot,immunofluorescence and other assays were carried out to explore the effect of puerarin on wound healing and its molecular mechanism.Results:Animal experiments found that the wound healing of diabetic mice treated with puerarin was significantly accelerated,and histological analysis found that puerarin treatment markedly decreased the infiltration of macrophages and neutrophils in wound tissue.Through western blot,RT-qPCR and immunofluorescence experiments,it was observed that puerarin treatment remarkably inhibited nuclear factor kinase B(NF-κB)and mitogen-activated protein kinase(MAPK)signaling pathways,downregulated the expression of inflammatory cytokines and induced the M2 polarization of macrophages.At the cellular level,we also observed that puerarin improved M2 macrophage polarization and inhibited inflammatory pathway activation in a high-glucose culture.Conclusion:Puerarin has a significant therapeutic effect on wound healing in diabetic mice.The therapeutic effect is achieved by regulating macrophage polarization through suppressing NF-κB and MAPK signaling cascades.
基金supported by the National Natural Science Foundation of China(Nos.81430072,81421003,81602641,81572929).
文摘Background:Gastric cancer(GC)is one of the most common malignancies worldwide,particularly in China.DNA damage-inducible transcript 4(DDIT4)is a mammalian target of rapamycin inhibitor and is induced by various cellular stresses;however,its critical role in GC remains poorly understood.The present study aimed to investigate the poten-tial relationship and the underlying mechanism between DDIT4 and GC development.Methods:We used western blotting,real-time polymerase chain reaction,and immunohistochemical or immunoflu-orescence to determine DDIT4 expression in GC cells and tissues.High-content screening,cell counting kit-8 assays,colony formation,and in vivo tumorigenesis assays were performed to evaluate cell proliferation.Flow cytometry was used to investigate cell apoptosis and cell cycle distribution.Results:DDIT4 was upregulated in GC cells and tissue.Furthermore,downregulating DDIT4 in GC cells inhibited proliferation both in vitro and in vivo and increased 5-fluorouracil-induced apoptosis and cell cycle arrest.In contrast,ectopic expression of DDIT4 in normal gastric epithelial cells promoted proliferation and attenuated chemosensitivity.Further analysis indicated that the mitogen-activated protein kinase and p53 signaling pathways were involved in the suppression of proliferation,and increased chemosensitivity upon DDIT4 downregulation.Conclusion:DDIT4 promotes GC proliferation and tumorigenesis,providing new insights into the role of DDIT4 in the tumorigenesis of human GC.
