Small extracellular vesicles (sEVs) participate in the pathological progression of high glucose (HG)-induced kidney injury, which is closely related to diabetic nephropathy. How sEVs specifically mediate the cell biom...Small extracellular vesicles (sEVs) participate in the pathological progression of high glucose (HG)-induced kidney injury, which is closely related to diabetic nephropathy. How sEVs specifically mediate the cell biomechanics underlying HG injury is unclear. Herein, we utilized a versatile atomic force microscope to determine the contributions of sEVs in HG-induced cellular injury. The sEVs extracted from the culture medium of human proximal tubule kidney (HK-2) cells treated by HG for 72 h (HG-induced sEVs) were verified and analyzed by multiple techniques, and the results indicated the effective production and the effect of dehydration on the shape of HG-induced sEVs. Further investigation on the morphologies of HK-2 cells treated by HG-induced sEVs showed that the surface roughness of the HK-2 cells increased, and their pseudopodia transitioned from lamellipodia to filopodia, with almost doubled mean pseudopodia length. Quantitative analysis of the mechanical responses of the cells revealed that the mean Young’s modulus increased by 26.2%, and the mean adhesion decreased by 36.8%. The indirect mediation of cellular biomechanics guided by HG-induced sEVs was evaluated by comparing it with previously studied direct HG injury. The HG-induced sEVs caused a greater reduction in cell adhesion and an increase in Young’s modulus compared with direct HG stimulation. This work suggested the ability of HG-induced sEVs to elicit specific biomechanical responses during HG injury, advancing the understanding of the injury mechanism caused by HG. The comparison of the cellular biomechanics between direct and indirect HG stimulations through HG-induced sEVs can be beneficial for the diagnosis and treatment of kidney injury.展开更多
Liver fibrosis is a significant health burden,marked by the consistent deposition of collagen.Unfortunately,the currently available treatment approaches for this condition are far from optimal.Lysyl oxidase-like prote...Liver fibrosis is a significant health burden,marked by the consistent deposition of collagen.Unfortunately,the currently available treatment approaches for this condition are far from optimal.Lysyl oxidase-like protein 2(LOXL2)secreted by hepatic stellate cells(HSCs)is a crucial player in the cross-linking of matrix collagen and is a significant target for treating liver fibrosis.Mesenchymal stem cell-derived small extracellular vesicles(MSC-sEVs)have been proposed as a potential treatment option for chronic liver disorders.Previous studies have found that MSC-sEV can be used for microRNA delivery into target cells or tissues.It is currently unclear whether microRNA-4465(miR-4465)can target LOXL2 and inhibit HSC activation.Additionally,it is uncertain whether MSC-sEV can be utilized as a gene therapy vector to carry miR-4465 and effectively inhibit the progression of liver fibrosis.This study explored the effect of miR-4465-modified MSC-sEV(MSC-sEVmiR-4465)on LOXL2 expression and liver fibrosis development.The results showed that miR-4465 can bind specifically to the promoter of the LOXL2 gene in HSC.Moreover,MSC-sEVmiR-4465 inhibited HSC activation and collagen expression by downregulating LOXL2 expression in vitro.MSC-sEVmiR-4465 injection could reduce HSC activation and collagen deposition in the CCl4-induced mouse model.MSC-sEVmiR-4465 mediating via LOXL2 also hindered the migration and invasion of HepG2 cells.In conclusion,we found that MSC-sEV can deliver miR-4465 into HSC to alleviate liver fibrosis via altering LOXL2,which might provide a promising therapeutic strategy for liver diseases.展开更多
Gigacycle fatigue behavior of 60Si2CrVA high strength spring steel was investigated by ultrasonic fatigue test machine. Fatigue fractography was observed by scanning electron microscopy （SEM）. Maximum inclusion size...Gigacycle fatigue behavior of 60Si2CrVA high strength spring steel was investigated by ultrasonic fatigue test machine. Fatigue fractography was observed by scanning electron microscopy （SEM）. Maximum inclusion sizes and fatigue strength in different volumes were estimated by statistics of extreme values （SEV） and generalized Pareto distribution （GPD） methods. The results showed that S N curves of 60Si2CrVA spring steels for two rolling processes were not horizontal asymptotes but a gradient in a regime of 109 cycles, and traditional fatigue limits were eliminated. Surface machined topography and inclusions in steel were major factors that led to elimination of fatigue limit for 60Si2CrVA spring steel. The SEV and GPD methods could effectively predict size of the maximum inclusion and fatigue strength in different volumes of 60Si2CrVA spring steel. Predicted fatigue strength was in accordance with experimental results by ultrasonic fatigue testing.展开更多
基金supported by National Natural Science Foundation Program of China(No.62175020)EU H2020 Program(ENSIGN No.101086226)+2 种基金Jilin Provincial Science and Technology Program(Nos.20210101038JC,2020C022-1,20190201287JC and 20190702002GH),Jilin Provincial Education Department(JJKH20220781KJ)“111”Project of China(D17017)This work was also partly supported by Changli Nano Biotechnology(China)and China Scholarship Council(CSC,No.202007585007).
文摘Small extracellular vesicles (sEVs) participate in the pathological progression of high glucose (HG)-induced kidney injury, which is closely related to diabetic nephropathy. How sEVs specifically mediate the cell biomechanics underlying HG injury is unclear. Herein, we utilized a versatile atomic force microscope to determine the contributions of sEVs in HG-induced cellular injury. The sEVs extracted from the culture medium of human proximal tubule kidney (HK-2) cells treated by HG for 72 h (HG-induced sEVs) were verified and analyzed by multiple techniques, and the results indicated the effective production and the effect of dehydration on the shape of HG-induced sEVs. Further investigation on the morphologies of HK-2 cells treated by HG-induced sEVs showed that the surface roughness of the HK-2 cells increased, and their pseudopodia transitioned from lamellipodia to filopodia, with almost doubled mean pseudopodia length. Quantitative analysis of the mechanical responses of the cells revealed that the mean Young’s modulus increased by 26.2%, and the mean adhesion decreased by 36.8%. The indirect mediation of cellular biomechanics guided by HG-induced sEVs was evaluated by comparing it with previously studied direct HG injury. The HG-induced sEVs caused a greater reduction in cell adhesion and an increase in Young’s modulus compared with direct HG stimulation. This work suggested the ability of HG-induced sEVs to elicit specific biomechanical responses during HG injury, advancing the understanding of the injury mechanism caused by HG. The comparison of the cellular biomechanics between direct and indirect HG stimulations through HG-induced sEVs can be beneficial for the diagnosis and treatment of kidney injury.
基金supported by the National Natural Science Foundation of China(No.82272421)the Jiangsu Provincial Key Research and Development Program(No.BE2021690)+2 种基金the Changzhou's 14th Five-year Plan Project to Train Highlevel Health Professionals(No.2022CZLJ027)the Scientific Project of Jiangsu Health Commission(No.Z2020038)the Changzhou Sci&Tech Program(No.CJ20220164),China.
文摘Liver fibrosis is a significant health burden,marked by the consistent deposition of collagen.Unfortunately,the currently available treatment approaches for this condition are far from optimal.Lysyl oxidase-like protein 2(LOXL2)secreted by hepatic stellate cells(HSCs)is a crucial player in the cross-linking of matrix collagen and is a significant target for treating liver fibrosis.Mesenchymal stem cell-derived small extracellular vesicles(MSC-sEVs)have been proposed as a potential treatment option for chronic liver disorders.Previous studies have found that MSC-sEV can be used for microRNA delivery into target cells or tissues.It is currently unclear whether microRNA-4465(miR-4465)can target LOXL2 and inhibit HSC activation.Additionally,it is uncertain whether MSC-sEV can be utilized as a gene therapy vector to carry miR-4465 and effectively inhibit the progression of liver fibrosis.This study explored the effect of miR-4465-modified MSC-sEV(MSC-sEVmiR-4465)on LOXL2 expression and liver fibrosis development.The results showed that miR-4465 can bind specifically to the promoter of the LOXL2 gene in HSC.Moreover,MSC-sEVmiR-4465 inhibited HSC activation and collagen expression by downregulating LOXL2 expression in vitro.MSC-sEVmiR-4465 injection could reduce HSC activation and collagen deposition in the CCl4-induced mouse model.MSC-sEVmiR-4465 mediating via LOXL2 also hindered the migration and invasion of HepG2 cells.In conclusion,we found that MSC-sEV can deliver miR-4465 into HSC to alleviate liver fibrosis via altering LOXL2,which might provide a promising therapeutic strategy for liver diseases.
基金Sponsored by National Basic Research Program(973 Program)of China(2004CB619100)
文摘Gigacycle fatigue behavior of 60Si2CrVA high strength spring steel was investigated by ultrasonic fatigue test machine. Fatigue fractography was observed by scanning electron microscopy （SEM）. Maximum inclusion sizes and fatigue strength in different volumes were estimated by statistics of extreme values （SEV） and generalized Pareto distribution （GPD） methods. The results showed that S N curves of 60Si2CrVA spring steels for two rolling processes were not horizontal asymptotes but a gradient in a regime of 109 cycles, and traditional fatigue limits were eliminated. Surface machined topography and inclusions in steel were major factors that led to elimination of fatigue limit for 60Si2CrVA spring steel. The SEV and GPD methods could effectively predict size of the maximum inclusion and fatigue strength in different volumes of 60Si2CrVA spring steel. Predicted fatigue strength was in accordance with experimental results by ultrasonic fatigue testing.
