Objective This study aimed to assess the protective value of adiponectin(APN)in pancreatic islet injury induced by chronic intermittent hypoxia(CIH).Methods Sixty rats were randomly divided into three groups:normal co...Objective This study aimed to assess the protective value of adiponectin(APN)in pancreatic islet injury induced by chronic intermittent hypoxia(CIH).Methods Sixty rats were randomly divided into three groups:normal control(NC)group,CIH group,and CIH with APN supplement(CIH+APN)group.After 5 weeks of CIH exposure,we conducted oral glucose tolerance tests(OGTT)and insulin released test(IRT),examined and compared the adenosine triphosphate(ATP)levels,mitochondrial membrane potential(MMP)levels,reactive oxygen species(ROS)levels,enzymes gene expression levels of Ant1,Cs,Hmox1,and Cox4 i1 which represented mitochondrial tricarboxylic acid cycle function,the protein and gene expression levels of DRP1,FIS1,MFN1,and OPA1 which represented mitochondrial fusion and division,and the protein expression levels of BAX,BCL-2,cleaved Caspase-3,and cleaved PARP which represented mitochondrial associated apoptosis pathway of pancreatic islet.Results OGTT and IRT showed blood glucose and insulin levels had no differences among the NC,CIH and CIH+APN groups(both P>0.05)at 0 min,20 min,30 min,60 min,120 min.However,we found that compared to NC group,CIH increased the ROS level,reduced ATP level and MMP level.The islets of CIH exposed rats showed reduced gene expression levels of Ant1,Cs,Hmox1,and Cox4 i1,decreased protein and gene expression levels of MFN1 and OPA1,increased protein and gene expression levels of DRP1 and FIS1,increased protein expression levels of cleaved Caspase-3 and cleaved PARP,with lower ratio of BCL-2/BAX at protein expression level.All the differences among three groups were statistically significant.APN treated CIH rats showed mitigated changes in the above measurements associated with islet injuries.Conclusion APN may ameliorate the pancreatic islet injury induced by CIH via inhibiting the imbalance in mitochondrial fusion and division.展开更多
A dual thermocouple difference technique is developed to determine the accuracy and anti-interference ability in the process of intracellular temperature measurement.First,two micro-nano thermocouples(TC)and a high-pr...A dual thermocouple difference technique is developed to determine the accuracy and anti-interference ability in the process of intracellular temperature measurement.First,two micro-nano thermocouples(TC)and a high-precision signal acquisition module are used to measure the temperature difference between the cell and the culture medium(separated about 10μm from the cell).The cold junctions of two TCs are connected to eliminate the setting of the reference temperature and enhance the anti-interference ability.Then,a low-noise voltage amplifier and digital acquisition card are used to sample signals.In order to verify the feasibility of the dual thermocouple difference method,the temperature changes of U251 cells are detected.The calibration results of two TCs show that the Seebeck coefficient is about 5μV/℃,and the signal acquisition accuracy is 0.5μV in a low voltage range(0-15μV).With the dual thermocouple difference method,errors due to the cold junctions can be removed and the interference caused by environmental temperature fluctuation can be reduced.The phenomenon of cellular temperature increase proves that the dual thermocouple difference method can detect the tiny temperature change of a single cell.The method potentially is a highly powerful technique for studying local thermogenesis of cells and helps to explore the relationship between cellular thermogenesis and cellular processes.展开更多
文摘Objective This study aimed to assess the protective value of adiponectin(APN)in pancreatic islet injury induced by chronic intermittent hypoxia(CIH).Methods Sixty rats were randomly divided into three groups:normal control(NC)group,CIH group,and CIH with APN supplement(CIH+APN)group.After 5 weeks of CIH exposure,we conducted oral glucose tolerance tests(OGTT)and insulin released test(IRT),examined and compared the adenosine triphosphate(ATP)levels,mitochondrial membrane potential(MMP)levels,reactive oxygen species(ROS)levels,enzymes gene expression levels of Ant1,Cs,Hmox1,and Cox4 i1 which represented mitochondrial tricarboxylic acid cycle function,the protein and gene expression levels of DRP1,FIS1,MFN1,and OPA1 which represented mitochondrial fusion and division,and the protein expression levels of BAX,BCL-2,cleaved Caspase-3,and cleaved PARP which represented mitochondrial associated apoptosis pathway of pancreatic islet.Results OGTT and IRT showed blood glucose and insulin levels had no differences among the NC,CIH and CIH+APN groups(both P>0.05)at 0 min,20 min,30 min,60 min,120 min.However,we found that compared to NC group,CIH increased the ROS level,reduced ATP level and MMP level.The islets of CIH exposed rats showed reduced gene expression levels of Ant1,Cs,Hmox1,and Cox4 i1,decreased protein and gene expression levels of MFN1 and OPA1,increased protein and gene expression levels of DRP1 and FIS1,increased protein expression levels of cleaved Caspase-3 and cleaved PARP,with lower ratio of BCL-2/BAX at protein expression level.All the differences among three groups were statistically significant.APN treated CIH rats showed mitigated changes in the above measurements associated with islet injuries.Conclusion APN may ameliorate the pancreatic islet injury induced by CIH via inhibiting the imbalance in mitochondrial fusion and division.
基金The National Key Research and Development Program of China(No.2017YFA0104302)the National Natural Science Foundation of China(No.61420106012,61821002).
文摘A dual thermocouple difference technique is developed to determine the accuracy and anti-interference ability in the process of intracellular temperature measurement.First,two micro-nano thermocouples(TC)and a high-precision signal acquisition module are used to measure the temperature difference between the cell and the culture medium(separated about 10μm from the cell).The cold junctions of two TCs are connected to eliminate the setting of the reference temperature and enhance the anti-interference ability.Then,a low-noise voltage amplifier and digital acquisition card are used to sample signals.In order to verify the feasibility of the dual thermocouple difference method,the temperature changes of U251 cells are detected.The calibration results of two TCs show that the Seebeck coefficient is about 5μV/℃,and the signal acquisition accuracy is 0.5μV in a low voltage range(0-15μV).With the dual thermocouple difference method,errors due to the cold junctions can be removed and the interference caused by environmental temperature fluctuation can be reduced.The phenomenon of cellular temperature increase proves that the dual thermocouple difference method can detect the tiny temperature change of a single cell.The method potentially is a highly powerful technique for studying local thermogenesis of cells and helps to explore the relationship between cellular thermogenesis and cellular processes.
