Reactive oxygen species(ROS) are produced during normal physiologic processes with the consumption of oxygen. While ROS play signaling roles, when they are produced in excess beyond normal antioxidative capacity this ...Reactive oxygen species(ROS) are produced during normal physiologic processes with the consumption of oxygen. While ROS play signaling roles, when they are produced in excess beyond normal antioxidative capacity this can cause pathogenic damage to cells. The majority of such oxidation occurs in polyunsaturated fatty acids and sulfhydryl group in proteins, resulting in lipid peroxidation and protein misfolding, respectively. The accumulation of misfolded proteins in the endoplasmic reticulum(ER) is enhanced under conditions of oxidative stress and results in ER stress, which, together, leads to the malfunction of cellular homeostasis. Multiple types of defensive machinery are activated in unfolded protein response under ER stress to resolve this unfavorable situation. ER stress triggers the malfunction of protein secretion and is associated with a variety of pathogenic conditions including defective insulin secretion from pancreatic β-cells and accelerated lipid droplet formation in hepatocytes. Herein we use nonalcoholic fatty liver disease(NAFLD) as an illustration of such pathological liver conditions that result from ER stress in association with oxidative stress. Protecting the ER by eliminating excessive ROS viathe administration of antioxidants or by enhancing lipidmetabolizing capacity via the activation of peroxisome proliferator-activated receptors represent promising therapeutics for NAFLD.展开更多
Background Peroxisome proliferator-activated receptor （PPAR） a is one of the subtypes of PPARs. It regulates metabolism of lipid and lipoprotein, as well as glucose homeostasis. In addition, PPARa influences cellula...Background Peroxisome proliferator-activated receptor （PPAR） a is one of the subtypes of PPARs. It regulates metabolism of lipid and lipoprotein, as well as glucose homeostasis. In addition, PPARa influences cellular proliferation, inflammation, differentiation and apoptosis, which plays a vital role in cardiovascular diseases. The purpose of this study was to investigate the role and mechanisms of PPARa activation in relation to acute myocardial damage induced by isoproterenol in rats. Methods Thirty male Wister rats were randomly divided into control group, isoproterenol （Iso） injured group and fenofibrate （FF） treatment group. Acute myocardial damage caused by isoproterenol intraperitoneal injection induced ischemia was established. We determined the levels of creatine kinase （CK） and lactic dehydrogenase （LDH） in serum as well as the concentrations of free fatty acids （FFA） in serum and myocardium. The mRNA expressions of PPARa, muscular type carnitine palmitransferase （M-CPT-I） and medium chain lipid acetyl coenzyme A dehydrogenase （MCAD） were analyzed by reverse transcription-polymerase chain reaction （RT-PCR）. Results Compared with the control group, the levels of serum CK and LDH were significantly increased after FF and Iso treatments. Moreover, the concentrations of FFA in both serum and myocardium were obviously increased in the Iso group and FF group, while the mRNAexpressions of PPARa, M-CPT-I and MCAD declined, respectively （P〈0.01）. When compared with the Iso group, significant decreases in serum CK and LDH were observed in the FF group. The concentrations of FFA both in serum and myocardial tissue were markedly decreased in the FF group, while the expressions of PPARa, M-CPT-I and MCAD mRNA were increased （vs Iso, P〈0.01）. Conclusions The utilization of FFA was reduced in isoproterenol induced acute myocardial damage. PPARa activation by its activator fenofibrate may play a key role in energy metabolism in acute myocardial damage induced by isoproter展开更多
Background Steroid-induced osteonecrosis of the femoral head （ONFH） is a common clinical disease,with a high disability rate.At present,efficient prevention and treatment of steroid-induced ONFH is still lacking.The...Background Steroid-induced osteonecrosis of the femoral head （ONFH） is a common clinical disease,with a high disability rate.At present,efficient prevention and treatment of steroid-induced ONFH is still lacking.The peroxisome proliferator-activated receptor-γ （PPARγ） is recognized as an important pathogenic gene for the development of steroid-induced ONFH.RNA interference （RNAi） is a tool for functional gene analysis,which has been successfully used to down-regulate the levels of specific target proteins.Therefore,down-regulation of PPARγ expression by RNAi may prevent the incidence of steroid-induced ONFH.Methods According to the principles of siRNA design,three duplex siRNA sequences （971-989,1253-1271 and 1367-1385） derived from the PPARy gene （NM_001082148） were synthesized.These duplexes were annealed,purified and ligated into 1.0-cytomegalovirus （CMV） shuttle vector.The shuttle vector was transfected into HEK293 cells.The HEK293 generated recombinant adenovirus vector carrying PPARγ siRNA sequences was purified and the titer of recombinant adenovirus was determined.Results After the annealing of single-strand DNA oligo encoding short hairpin RNA （shRNA） sequences,products were identified by gel electrophoresis.These products were ligated into the 1.0-CMV shuttle vector and the recombinant shuttle vectors 1.0-CMV-971,1.0-CMV-1253 and 1.0-CMV-1367 were constructed.These sequences of these recombinant vectors were confirmed.We then successfully constructed the recombinant adenovirus vector carrying siRNA targeting PPARγ.After purification,the virus titer was higher than 1010 plaque forming unit （PFU）/ml.Conclusion In this study,three recombinant adenovirus shuttle vectors carrying siRNA targeting PPARγ,including shuttle vectors 1.0-CMV-971,1.0-CMV-1253 and 1.0-CMV-1367,were successfully constructed and high titers of recombinant adenovirus were obtained.展开更多
AIM：To explore the role of Pioglitazone（Pio） on a mouse model of retinal ischemia/reperfusion（I/R） injury and to elucidate the potential mechanism.METHODS：Retinal ischemia was induced in mice by increasing the i...AIM：To explore the role of Pioglitazone（Pio） on a mouse model of retinal ischemia/reperfusion（I/R） injury and to elucidate the potential mechanism.METHODS：Retinal ischemia was induced in mice by increasing the intraocular pressure,and Pio was administered 4 h though periocular injection before I/R.The number of cells in the ganglion cell layer（GCL） was counted 7 d after retinal I/R injury.Glial fibrillary acidic protein（GFAP）,nuclear factor-kappa B（NF-κB）,p38,phosphorylated-p38,PPAR-γ,interleukin-1β（IL-1β）,Toll-like receptor 4（TLR4）,NLRP3,cleaved caspase-1,caspase-1 were determined by real-time polymerase chain reaction and Western blotting.RESULTS：Pio promoted the survival of retinal cells in GCL following retinal I/R injury（P〈0.05）.Besides,retinal I/R injury stimulated the expression of GFAP and TLR4,which were partially reversed by Pio treatment（P0.05）.Retinal I/R injury-upregulated expression of NLRP3,cleaved caspase-1,IL-1β was attenuated after Pio treatment（P〈0.05）.Moreover,I/R injury induced activation of NF-κB and p38 were inhibited by Pio treatment（P〈0.05）.CONCLUSION：Pio promotes retinal ganglion cells survival by suppressing I/R-induced activation of TLR4/NLRP3 inflammasomes via inhibiting NF-κB and p38 phosphorylation.展开更多
基金Supported by a Joint Research Project between Japan Society for Promotion of Science and National Research Foundation of South Korea(in part)
文摘Reactive oxygen species(ROS) are produced during normal physiologic processes with the consumption of oxygen. While ROS play signaling roles, when they are produced in excess beyond normal antioxidative capacity this can cause pathogenic damage to cells. The majority of such oxidation occurs in polyunsaturated fatty acids and sulfhydryl group in proteins, resulting in lipid peroxidation and protein misfolding, respectively. The accumulation of misfolded proteins in the endoplasmic reticulum(ER) is enhanced under conditions of oxidative stress and results in ER stress, which, together, leads to the malfunction of cellular homeostasis. Multiple types of defensive machinery are activated in unfolded protein response under ER stress to resolve this unfavorable situation. ER stress triggers the malfunction of protein secretion and is associated with a variety of pathogenic conditions including defective insulin secretion from pancreatic β-cells and accelerated lipid droplet formation in hepatocytes. Herein we use nonalcoholic fatty liver disease(NAFLD) as an illustration of such pathological liver conditions that result from ER stress in association with oxidative stress. Protecting the ER by eliminating excessive ROS viathe administration of antioxidants or by enhancing lipidmetabolizing capacity via the activation of peroxisome proliferator-activated receptors represent promising therapeutics for NAFLD.
文摘Background Peroxisome proliferator-activated receptor （PPAR） a is one of the subtypes of PPARs. It regulates metabolism of lipid and lipoprotein, as well as glucose homeostasis. In addition, PPARa influences cellular proliferation, inflammation, differentiation and apoptosis, which plays a vital role in cardiovascular diseases. The purpose of this study was to investigate the role and mechanisms of PPARa activation in relation to acute myocardial damage induced by isoproterenol in rats. Methods Thirty male Wister rats were randomly divided into control group, isoproterenol （Iso） injured group and fenofibrate （FF） treatment group. Acute myocardial damage caused by isoproterenol intraperitoneal injection induced ischemia was established. We determined the levels of creatine kinase （CK） and lactic dehydrogenase （LDH） in serum as well as the concentrations of free fatty acids （FFA） in serum and myocardium. The mRNA expressions of PPARa, muscular type carnitine palmitransferase （M-CPT-I） and medium chain lipid acetyl coenzyme A dehydrogenase （MCAD） were analyzed by reverse transcription-polymerase chain reaction （RT-PCR）. Results Compared with the control group, the levels of serum CK and LDH were significantly increased after FF and Iso treatments. Moreover, the concentrations of FFA in both serum and myocardium were obviously increased in the Iso group and FF group, while the mRNAexpressions of PPARa, M-CPT-I and MCAD declined, respectively （P〈0.01）. When compared with the Iso group, significant decreases in serum CK and LDH were observed in the FF group. The concentrations of FFA both in serum and myocardial tissue were markedly decreased in the FF group, while the expressions of PPARa, M-CPT-I and MCAD mRNA were increased （vs Iso, P〈0.01）. Conclusions The utilization of FFA was reduced in isoproterenol induced acute myocardial damage. PPARa activation by its activator fenofibrate may play a key role in energy metabolism in acute myocardial damage induced by isoproter
文摘Background Steroid-induced osteonecrosis of the femoral head （ONFH） is a common clinical disease,with a high disability rate.At present,efficient prevention and treatment of steroid-induced ONFH is still lacking.The peroxisome proliferator-activated receptor-γ （PPARγ） is recognized as an important pathogenic gene for the development of steroid-induced ONFH.RNA interference （RNAi） is a tool for functional gene analysis,which has been successfully used to down-regulate the levels of specific target proteins.Therefore,down-regulation of PPARγ expression by RNAi may prevent the incidence of steroid-induced ONFH.Methods According to the principles of siRNA design,three duplex siRNA sequences （971-989,1253-1271 and 1367-1385） derived from the PPARy gene （NM_001082148） were synthesized.These duplexes were annealed,purified and ligated into 1.0-cytomegalovirus （CMV） shuttle vector.The shuttle vector was transfected into HEK293 cells.The HEK293 generated recombinant adenovirus vector carrying PPARγ siRNA sequences was purified and the titer of recombinant adenovirus was determined.Results After the annealing of single-strand DNA oligo encoding short hairpin RNA （shRNA） sequences,products were identified by gel electrophoresis.These products were ligated into the 1.0-CMV shuttle vector and the recombinant shuttle vectors 1.0-CMV-971,1.0-CMV-1253 and 1.0-CMV-1367 were constructed.These sequences of these recombinant vectors were confirmed.We then successfully constructed the recombinant adenovirus vector carrying siRNA targeting PPARγ.After purification,the virus titer was higher than 1010 plaque forming unit （PFU）/ml.Conclusion In this study,three recombinant adenovirus shuttle vectors carrying siRNA targeting PPARγ,including shuttle vectors 1.0-CMV-971,1.0-CMV-1253 and 1.0-CMV-1367,were successfully constructed and high titers of recombinant adenovirus were obtained.
基金Supported by National Natural Science Foundation of China(No.81300777)the General Program of Shanghai Municipal Health and Family Planning Commission(No.201440522)
文摘AIM：To explore the role of Pioglitazone（Pio） on a mouse model of retinal ischemia/reperfusion（I/R） injury and to elucidate the potential mechanism.METHODS：Retinal ischemia was induced in mice by increasing the intraocular pressure,and Pio was administered 4 h though periocular injection before I/R.The number of cells in the ganglion cell layer（GCL） was counted 7 d after retinal I/R injury.Glial fibrillary acidic protein（GFAP）,nuclear factor-kappa B（NF-κB）,p38,phosphorylated-p38,PPAR-γ,interleukin-1β（IL-1β）,Toll-like receptor 4（TLR4）,NLRP3,cleaved caspase-1,caspase-1 were determined by real-time polymerase chain reaction and Western blotting.RESULTS：Pio promoted the survival of retinal cells in GCL following retinal I/R injury（P〈0.05）.Besides,retinal I/R injury stimulated the expression of GFAP and TLR4,which were partially reversed by Pio treatment（P0.05）.Retinal I/R injury-upregulated expression of NLRP3,cleaved caspase-1,IL-1β was attenuated after Pio treatment（P〈0.05）.Moreover,I/R injury induced activation of NF-κB and p38 were inhibited by Pio treatment（P〈0.05）.CONCLUSION：Pio promotes retinal ganglion cells survival by suppressing I/R-induced activation of TLR4/NLRP3 inflammasomes via inhibiting NF-κB and p38 phosphorylation.
