Objective Diabetic patients pose a greater challenge in managing chronic wound healing,leading to a higher amputation risk compared to non-diabetic patients.Due to their paracrine function by secreting various cytokin...Objective Diabetic patients pose a greater challenge in managing chronic wound healing,leading to a higher amputation risk compared to non-diabetic patients.Due to their paracrine function by secreting various cytokines and angiogenic factors,mesenchymal stem cells(MSCs)have been acknowledged to be a potential agent in modulating wound healing process.However,post-transplanted MSCs are vulnerable to death,indicating poor survival and migration ability in the wound site of the host,especially under hyperglycemia.As hyperglycemia induces reactive oxygen species(ROS)generation and cellular apoptosis,improvement of MSCs survival and migration potentials under hyperglycemia could contribute to a more efficient MSCs-based wound healing therapy.Salidroside(Sa),a small-molecule drug derived from Rhodiola plant,has been proved to enhance the paracrine function of skeletal muscle cells,as well as their migration even under hypoxichyperglycemia.Herein,we investigated whether Sa could improve the survival and migration potentials of MSCs,subsequently enhance the wound healing process under hyperglycemia.Methods MSCs were cultured under three conditions:low glucose,high glucose,and high glucose+Sa.qPCR analysis and western blotting were done to examine the mRNA and protein expression level of several factors which are important in upregulating the wound healing process.MTT colorimetric assay,intracellular ROS detection,and flow cytometry assay were employed to examine the effect of Sa in MSCs survival.Transwell chamber assay,scratch assay,and phalloidin staining were done to elucidate the role of Sa in regulating MSCs migration potential.For in vivo experiment,diabetic wound healing mice model was generated to elucidate the effect of Sa-pretreated MSCs transplantation in wound closure rate,as well as re-epithelization status,observed with hematoxylin and eosin staining.The diabetic wound healing mice model were divided into three groups:1)mice injected with PBS,2)mice transplanted with PBS-pretreated MSCs,and 3)mice transplanted with Sa-pretreated MSCs.Results(1)Hyperglycemic condition induced the generation of ROS and suppressed total cell number of MSCs,while Sa treatment into MSCs restored these hyperglycemia-induced alterations.In line with this,total apoptotic cells were also suppressed by treating MSCs with Sa.The expression level of cell survival factor,heme-oxygenase 1(HO-1),was enhanced in Sa-pretreated MSCs.Further treatment of HO-1 inhibitor into Sa-pretreated MSCs nullified the ROS level and total apoptotic cells,indica-ting the importance of HO-1 in mediating the Sa-induced survival of MSCs under hyperglycemia.(2)Transwell chamber and scratch assay results showed that Sa-pretreated MSCs have a higher migration potential under hyperglycemia,supported by higher F-actin polymerization fractal dimension.Fibroblast growth factor 2(FGF2)and hepatocyte growth factor(HGF)expression level,which are essential factors for cell migration,were also improved in Sa-pretreated MSCs under hyperglycemia.(3)In diabetic wound healing mice model,transplantation of Sa-pretreated MSCs resulted in significantly improved wound closure rate and re-epithelization.The protein levels of HO-1,FGF2,and HGF were also enhanced in the tissues obtained from the wound site of diabetic wound healing mice model which were transplanted with Sa-pretreated MSCs.Conclusions Salidroside pretreatment on MSCs could improve their survival and migration potentials,subsequently promoting wound healing process under hyperglycemia.This prospective MSC-based therapy could serve as a novel strategy to improve diabetic wound healing.展开更多
Objective Mitral valve(MV)plays an importance role in regulating blood flow from left atrium to left ventricle and preventing backflow to left atrium.Mitral Valve consist of four important parts;anterior leaflet,poste...Objective Mitral valve(MV)plays an importance role in regulating blood flow from left atrium to left ventricle and preventing backflow to left atrium.Mitral Valve consist of four important parts;anterior leaflet,posterior leaflet,chordae tendineae,and papillary muscles,which all work in harmony.The material properties alteration on the leaflet causes MV malfunction,and leading to valve diseases such as regurgitation and stenosis.The alteration may be caused by several factors such as calcification,genetic disorders,and infection,which usually have an influence to the mechanical properties,and thus affecting the mechanical behavior of MV.In consequence,some of the patients need MV replacement or repair to restore the normal function of MV.The important point for succeeding such a medical treatment depends on the technique,design,and material used in the treatment shall help rebuild the normal mechanical environment and behavior of MV.Therefore,the mechanical and materials characteristics of MV become a magnetism to explore.In this study,we present an integrated experimental and mathematical constitutive study base in collagen distribution aiming at the mechanical property differences in various region on MV.Methods and materials Both the size and composition of porcine valves are similar to human’s,so the porcine heart valve is often being used in experimental research.Mitral valve was isolated from fresh eight porcine hearts(250-500 gr),and perfused in PBS solution to maintain moist.Anterior and posterior leaflets were separated and dissected into 4 part(two 8~*8 mm rough zone and two clear zone samples)and 2 part(8~*8 mm belly and edge of the clear zone)respectively.Tracking markers(glass bean)were stickled on specimen with superglue(cyanoacrylate adhesive).Then,the specimen was mounted onto biaxial tester machine(CeIIScale,Biotester),and the tests are run by force control.During mechanical test,the specimen is immersed into PBS solution in physiological temperature(37℃).Every test procedure contains 8 preconditioning cycles and 8 loading cycles.The mechanical behavior was determined from the relationship between first Piola-Kirchoff stress and stretch.Constitutive model was reconstructed and material parameters were fitted from biaxial tensile result.Histological analyses were performed in the specimen before and after test.First,a piece of the specimen was cut and immersed in fixation solution(4%paraformaldehyde),then it was dehydrated in graded alcohol solution,and next embedding in paraffin wax block.Paraffin block was then cut and stained with VVG and Picro-sirius red.The collagen fibril orientation was observed from those histological results.Results The experimental results of the clear zone of MV’s first Piola-Kirchhoff stress and stretch curve are similar to those of the recent study from others,while result of the rough zone shows a different trend.This can be explained by differences in collagen distribution between clear zone and rough zone of MV.Our result thus allows for a refinement of computational models for more accurately predicting MV condition,where tissue heterogeneity plays an important role in the MV function.展开更多
基金Supported by grants from the National Natural Science Foundation of China ( 81372202,81872273, 31871367)
文摘Objective Diabetic patients pose a greater challenge in managing chronic wound healing,leading to a higher amputation risk compared to non-diabetic patients.Due to their paracrine function by secreting various cytokines and angiogenic factors,mesenchymal stem cells(MSCs)have been acknowledged to be a potential agent in modulating wound healing process.However,post-transplanted MSCs are vulnerable to death,indicating poor survival and migration ability in the wound site of the host,especially under hyperglycemia.As hyperglycemia induces reactive oxygen species(ROS)generation and cellular apoptosis,improvement of MSCs survival and migration potentials under hyperglycemia could contribute to a more efficient MSCs-based wound healing therapy.Salidroside(Sa),a small-molecule drug derived from Rhodiola plant,has been proved to enhance the paracrine function of skeletal muscle cells,as well as their migration even under hypoxichyperglycemia.Herein,we investigated whether Sa could improve the survival and migration potentials of MSCs,subsequently enhance the wound healing process under hyperglycemia.Methods MSCs were cultured under three conditions:low glucose,high glucose,and high glucose+Sa.qPCR analysis and western blotting were done to examine the mRNA and protein expression level of several factors which are important in upregulating the wound healing process.MTT colorimetric assay,intracellular ROS detection,and flow cytometry assay were employed to examine the effect of Sa in MSCs survival.Transwell chamber assay,scratch assay,and phalloidin staining were done to elucidate the role of Sa in regulating MSCs migration potential.For in vivo experiment,diabetic wound healing mice model was generated to elucidate the effect of Sa-pretreated MSCs transplantation in wound closure rate,as well as re-epithelization status,observed with hematoxylin and eosin staining.The diabetic wound healing mice model were divided into three groups:1)mice injected with PBS,2)mice transplanted with PBS-pretreated MSCs,and 3)mice transplanted with Sa-pretreated MSCs.Results(1)Hyperglycemic condition induced the generation of ROS and suppressed total cell number of MSCs,while Sa treatment into MSCs restored these hyperglycemia-induced alterations.In line with this,total apoptotic cells were also suppressed by treating MSCs with Sa.The expression level of cell survival factor,heme-oxygenase 1(HO-1),was enhanced in Sa-pretreated MSCs.Further treatment of HO-1 inhibitor into Sa-pretreated MSCs nullified the ROS level and total apoptotic cells,indica-ting the importance of HO-1 in mediating the Sa-induced survival of MSCs under hyperglycemia.(2)Transwell chamber and scratch assay results showed that Sa-pretreated MSCs have a higher migration potential under hyperglycemia,supported by higher F-actin polymerization fractal dimension.Fibroblast growth factor 2(FGF2)and hepatocyte growth factor(HGF)expression level,which are essential factors for cell migration,were also improved in Sa-pretreated MSCs under hyperglycemia.(3)In diabetic wound healing mice model,transplantation of Sa-pretreated MSCs resulted in significantly improved wound closure rate and re-epithelization.The protein levels of HO-1,FGF2,and HGF were also enhanced in the tissues obtained from the wound site of diabetic wound healing mice model which were transplanted with Sa-pretreated MSCs.Conclusions Salidroside pretreatment on MSCs could improve their survival and migration potentials,subsequently promoting wound healing process under hyperglycemia.This prospective MSC-based therapy could serve as a novel strategy to improve diabetic wound healing.
基金funded by National Nature Foundation of China ( 11532004,1140204,11832008)
文摘Objective Mitral valve(MV)plays an importance role in regulating blood flow from left atrium to left ventricle and preventing backflow to left atrium.Mitral Valve consist of four important parts;anterior leaflet,posterior leaflet,chordae tendineae,and papillary muscles,which all work in harmony.The material properties alteration on the leaflet causes MV malfunction,and leading to valve diseases such as regurgitation and stenosis.The alteration may be caused by several factors such as calcification,genetic disorders,and infection,which usually have an influence to the mechanical properties,and thus affecting the mechanical behavior of MV.In consequence,some of the patients need MV replacement or repair to restore the normal function of MV.The important point for succeeding such a medical treatment depends on the technique,design,and material used in the treatment shall help rebuild the normal mechanical environment and behavior of MV.Therefore,the mechanical and materials characteristics of MV become a magnetism to explore.In this study,we present an integrated experimental and mathematical constitutive study base in collagen distribution aiming at the mechanical property differences in various region on MV.Methods and materials Both the size and composition of porcine valves are similar to human’s,so the porcine heart valve is often being used in experimental research.Mitral valve was isolated from fresh eight porcine hearts(250-500 gr),and perfused in PBS solution to maintain moist.Anterior and posterior leaflets were separated and dissected into 4 part(two 8~*8 mm rough zone and two clear zone samples)and 2 part(8~*8 mm belly and edge of the clear zone)respectively.Tracking markers(glass bean)were stickled on specimen with superglue(cyanoacrylate adhesive).Then,the specimen was mounted onto biaxial tester machine(CeIIScale,Biotester),and the tests are run by force control.During mechanical test,the specimen is immersed into PBS solution in physiological temperature(37℃).Every test procedure contains 8 preconditioning cycles and 8 loading cycles.The mechanical behavior was determined from the relationship between first Piola-Kirchoff stress and stretch.Constitutive model was reconstructed and material parameters were fitted from biaxial tensile result.Histological analyses were performed in the specimen before and after test.First,a piece of the specimen was cut and immersed in fixation solution(4%paraformaldehyde),then it was dehydrated in graded alcohol solution,and next embedding in paraffin wax block.Paraffin block was then cut and stained with VVG and Picro-sirius red.The collagen fibril orientation was observed from those histological results.Results The experimental results of the clear zone of MV’s first Piola-Kirchhoff stress and stretch curve are similar to those of the recent study from others,while result of the rough zone shows a different trend.This can be explained by differences in collagen distribution between clear zone and rough zone of MV.Our result thus allows for a refinement of computational models for more accurately predicting MV condition,where tissue heterogeneity plays an important role in the MV function.
