BACKGROUND Diabetic retinopathy(DR)is a major ocular complication of diabetes mellitus,leading to visual impairment.Retinal pigment epithelium(RPE)injury is a key component of the outer blood retinal barrier,and its d...BACKGROUND Diabetic retinopathy(DR)is a major ocular complication of diabetes mellitus,leading to visual impairment.Retinal pigment epithelium(RPE)injury is a key component of the outer blood retinal barrier,and its damage is an important indicator of DR.Receptor for activated C kinase 1(RACK1)activates protein kinase C-ε(PKC-ε)to promote the generation of reactive oxygen species(ROS)in RPE cells,leading to apoptosis.Therefore,we hypothesize that the activation of RACK1 under hypoxic/high-glucose conditions may promote RPE cell apoptosis by modulating PKC-ε/ROS,thereby disrupting the barrier effect of the outer blood retinal barrier and contributing to the progression of DR.AIM To investigate the role and associated underlying mechanisms of RACK1 in the development of early DR.METHODS In this study,Sprague-Dawley rats and adult RPE cell line-19(ARPE-19)cells were used as in vivo and in vitro models,respectively,to explore the role of RACK1 in mediating PKC-εin early DR.Furthermore,the impact of RACK1 on apoptosis and barrier function of RPE cells was also investigated in the former model.RESULTS Streptozotocin-induced diabetic rats showed increased apoptosis and upregulated expression of RACK1 and PKC-εproteins in RPE cells following a prolonged modeling.Similarly,ARPE-19 cells exposed to high glucose and hypoxia displayed elevated mRNA and protein levels of RACK1 and PKC-ε,accompanied by an increases in ROS production,apoptosis rate,and monolayer permeability.However,silencing RACK1 significantly downregulated the expression of PKC-εand ROS,reduced cell apoptosis and permeability,and protected barrier function.CONCLUSION RACK1 plays a significant role in the development of early DR and might serve as a potential therapeutic target for DR by regulating RPE apoptosis and barrier function.展开更多
Background:Animal models are widely used in scientific research in order to obtain information from a whole organism under a specific set of experimental conditions.Various lineages of mice have been used to investiga...Background:Animal models are widely used in scientific research in order to obtain information from a whole organism under a specific set of experimental conditions.Various lineages of mice have been used to investigate diseases and new therapeutic strategies,and,consequently,hematological and biochemical tests in these laboratory animals are essential to validate scientific studies.Our study seeks to establish reference values for hematological and biochemical parameters of four lineages of mice.Methods:We evaluated the hematological and biochemical profiles of 20 males and 20 females from the lineages Swiss(heterogeneous),BALB/c and C57BL/6(isogenic),and B6D2F1(hybrid),totaling 160 mice.Analysis were standardized using the systems pocH-100iV Diff™for 19 hematological parameters and VITROS®350 for 12 biochemical parameters.Results:Results are shown as means and standard deviation,grouped by lineage and genre.Comparing the values obtained in this study with the values from previous studies,some variations were detected,which could be explained by differences in methodologies or individual variability.Conclusion:Thus our study shows that knowledge and disclosure of the values of physiological parameters of laboratory animals is necessary,and emphasises the importance of considering variations influenced by gender,lineage and genotype in the choice of the best experimental model.展开更多
Active vitamin D (1,25D) is a fat-soluble vitamin that is mainly produced in the skin by the conversion of 7-dehydrocholesterol under ultraviolet light stimulation.Its role in calcium homeostasis,bone growth, and prev...Active vitamin D (1,25D) is a fat-soluble vitamin that is mainly produced in the skin by the conversion of 7-dehydrocholesterol under ultraviolet light stimulation.Its role in calcium homeostasis,bone growth, and prevention of rickets and osteomalacia has been known for over two hundred years.Its展开更多
基金Supported by National Natural Science Foundation of China,No.82260211Key Research and Development Project in Jiangxi Province,No.20203BBG73058Chinese Medicine Science and Technology Project in Jiangxi Province,No.2020A0166.
文摘BACKGROUND Diabetic retinopathy(DR)is a major ocular complication of diabetes mellitus,leading to visual impairment.Retinal pigment epithelium(RPE)injury is a key component of the outer blood retinal barrier,and its damage is an important indicator of DR.Receptor for activated C kinase 1(RACK1)activates protein kinase C-ε(PKC-ε)to promote the generation of reactive oxygen species(ROS)in RPE cells,leading to apoptosis.Therefore,we hypothesize that the activation of RACK1 under hypoxic/high-glucose conditions may promote RPE cell apoptosis by modulating PKC-ε/ROS,thereby disrupting the barrier effect of the outer blood retinal barrier and contributing to the progression of DR.AIM To investigate the role and associated underlying mechanisms of RACK1 in the development of early DR.METHODS In this study,Sprague-Dawley rats and adult RPE cell line-19(ARPE-19)cells were used as in vivo and in vitro models,respectively,to explore the role of RACK1 in mediating PKC-εin early DR.Furthermore,the impact of RACK1 on apoptosis and barrier function of RPE cells was also investigated in the former model.RESULTS Streptozotocin-induced diabetic rats showed increased apoptosis and upregulated expression of RACK1 and PKC-εproteins in RPE cells following a prolonged modeling.Similarly,ARPE-19 cells exposed to high glucose and hypoxia displayed elevated mRNA and protein levels of RACK1 and PKC-ε,accompanied by an increases in ROS production,apoptosis rate,and monolayer permeability.However,silencing RACK1 significantly downregulated the expression of PKC-εand ROS,reduced cell apoptosis and permeability,and protected barrier function.CONCLUSION RACK1 plays a significant role in the development of early DR and might serve as a potential therapeutic target for DR by regulating RPE apoptosis and barrier function.
基金National Council for Scientific and Technological Development(CNPq)Coordination for the Improvement of Higher Level Personnel,Brazil(CAPES)Research Support Foundation for the State of Rio de Janeiro,Brazil(FAPERJ)。
文摘Background:Animal models are widely used in scientific research in order to obtain information from a whole organism under a specific set of experimental conditions.Various lineages of mice have been used to investigate diseases and new therapeutic strategies,and,consequently,hematological and biochemical tests in these laboratory animals are essential to validate scientific studies.Our study seeks to establish reference values for hematological and biochemical parameters of four lineages of mice.Methods:We evaluated the hematological and biochemical profiles of 20 males and 20 females from the lineages Swiss(heterogeneous),BALB/c and C57BL/6(isogenic),and B6D2F1(hybrid),totaling 160 mice.Analysis were standardized using the systems pocH-100iV Diff™for 19 hematological parameters and VITROS®350 for 12 biochemical parameters.Results:Results are shown as means and standard deviation,grouped by lineage and genre.Comparing the values obtained in this study with the values from previous studies,some variations were detected,which could be explained by differences in methodologies or individual variability.Conclusion:Thus our study shows that knowledge and disclosure of the values of physiological parameters of laboratory animals is necessary,and emphasises the importance of considering variations influenced by gender,lineage and genotype in the choice of the best experimental model.
基金Sao Paulo Research Foundation(FAPESP),[Grant No.2013/26257-8]
文摘Active vitamin D (1,25D) is a fat-soluble vitamin that is mainly produced in the skin by the conversion of 7-dehydrocholesterol under ultraviolet light stimulation.Its role in calcium homeostasis,bone growth, and prevention of rickets and osteomalacia has been known for over two hundred years.Its
