BACKGROUND Erianin is a natural bibenzyl compound extracted from Dendrobium chrysotoxum and is known for its anti-inflammatory and antioxidant properties.AIM To explore the possible therapeutic mechanisms of erianin a...BACKGROUND Erianin is a natural bibenzyl compound extracted from Dendrobium chrysotoxum and is known for its anti-inflammatory and antioxidant properties.AIM To explore the possible therapeutic mechanisms of erianin and determine if it can reduce cardiac damage in mice with type 2 diabetes.METHODS High-fat diet and intraperitoneal injections of streptozotocin were used to induce type 2 diabetes mellitus in C57BL/6 mice.Mice were divided into different groups including control,model,and treatment with various doses of erianin(10,20,and 40 mg/kg)as well as ML-385+erianin group.RESULTS Erianin reduced oxidative stress and inflammation and alleviated diabetic cardiomyopathy through the activation of the adenosine monophosphate-acti-vated protein kinase(AMPK)-nuclear factor erythroid 2-related factor 2(Nrf2)-heme oxygenase-1(HO-1)pathway.Treatments with erianin-M and erianin-H promoted weight stabilization and normalized fasting glucose levels relative to diabetic controls.Echocardiographic assessment demonstrated that erianin dose-dependently enhanced left ventricular systolic function(left ventricular ejection fraction,left ventricular fractional shortening)and mitigated ventricular remodeling(left ventricular internal diameter at end-diastole,left ventricular internal diameter at end-systole;P<0.05 vs model group).No significant differences were observed between the ML-385+erianin and placebo-treated groups.Histopathological examination through hematoxylin-eosin staining indicated that erianin ameliorated myocardial fiber fragmentation,structural disorganization,inflammatory cell infiltration,and cytolytic damage.Furthermore,it significantly reduced the serum levels of cardiac troponin I,creatine kinase,and its MB isoenzyme.However,the ML-385+erianin co-treatment failed to alleviate myocardial injury.Metabolic profiling revealed erianin-mediated improvements in glycemic regulation(glycated hemoglobin:P<0.001),plasma insulin homeostasis,and lipid metabolism(total cholesterol,triglycerides,low-density lipo-protein cholesterol reduction,and high-density lipoprotein cholesterol restoration;P<0.05 vs model group).Pro-inflammatory cytokines including tumor necrosis factor-α,interleukin(IL)-1β,and IL-6 were markedly suppressed in the erianin-M and erianin-H groups compared with the model group,whereas no significant differences were detected between the model and ML-385+erianin groups.Oxidative stress parameters showed decreased malondialdehyde levels accompanied by elevated superoxide dismutase and catalase activities in erianin-treated groups,with the most pronounced effects in the erianin-H group(P<0.05).Western blot analysis confirmed the significant upregulation of proteins associated with the AMPK/Nrf2/HO-1 pathway in erianin-M and erianin-H groups.These protective effects were abolished in the ML-385+erianin co-treatment group,which showed no statistical differences from the model group.CONCLUSION Erianin can effectively alleviate myocardial injury in type 2 diabetic mice by activating the AMPK-Nrf2-HO-1 pathway.展开更多
Treatment with metformin can lead to the recovery of pleiotropic biological activities after spinal cord injury.However,its effect on spinal cord injury in aged mice remains unclear.Considering the essential role of a...Treatment with metformin can lead to the recovery of pleiotropic biological activities after spinal cord injury.However,its effect on spinal cord injury in aged mice remains unclear.Considering the essential role of angiogenesis during the regeneration process,we hypothesized that metformin activates the adenosine monophosphate-activated protein kinase/endothelial nitric oxide synthase pathway in endothelial cells,thereby promoting microvascular regeneration in aged mice after spinal cord injury.In this study,we established young and aged mouse models of contusive spinal cord injury using a modified Allen method.We found that aging hindered the recovery of neurological function and the formation of blood vessels in the spinal cord.Treatment with metformin promoted spinal cord microvascular endothelial cell migration and blood vessel formation in vitro.Furthermore,intraperitoneal injection of metformin in an in vivo model promoted endothelial cell proliferation and increased the density of new blood vessels in the spinal cord,thereby improving neurological function.The role of metformin was reversed by compound C,an adenosine monophosphate-activated protein kinase inhibitor,both in vivo and in vitro,suggesting that the adenosine monophosphate-activated protein kinase/endothelial nitric oxide synthase pathway likely regulates metformin-mediated angiogenesis after spinal cord injury.These findings suggest that metformin promotes vascular regeneration in the injured spinal cord by activating the adenosine monophosphate-activated protein kinase/endothelial nitric oxide synthase pathway,thereby improving the neurological function of aged mice after spinal cord injury.展开更多
Objective:Mesenchymal stem cells(MSCs)are important cells in bone tissue engineering.Bone morphogenetic protein-2(BMP-2)effectively treats bone defects and nonunion.The purpose of this study is to investigate whether ...Objective:Mesenchymal stem cells(MSCs)are important cells in bone tissue engineering.Bone morphogenetic protein-2(BMP-2)effectively treats bone defects and nonunion.The purpose of this study is to investigate whether BMP-2 promotes bone formation and femoral fracture healing by inhibiting inflammation and promoting osteogenic differentiation of MSCs,in order to provide an experimental basis for developing more efficient fracture treatment strategies.Methods:Bone marrow-derived MSCs(BMSCs)were isolated from rats and treated withOE-BMP-2,the 5′-adenosinemonophosphate-activated protein kinase(AMPK)signal agonist 5-aminoimidazole-4-carboxamide ribonucleotide(AICAR),and the inhibitor Compound C.Osteogenic differentiation was evaluated through an alkaline phosphatase(ALP)kit,Western blot,and Alizarin Red S(ARS)staining.A rat model of femoral fracture was constructed,and fracture healing in the rats was detected by X-ray,microcomputed tomography(CT),and pathological staining.The AMPK signaling pathway and inflammation levels in the BMSCs and fracture model rats were measured by Western blot and enzyme-linked immunosorbent assay(ELISA)kits.Results:After BMP-2 overexpression,the ALP activity in osteogenic BMSCs was significantly increased(increased to 253.64%),the levels of osteogenic differentiation proteins(Osterix and osteocalcin)and p-AMPK Thr172 protein were significantly increased,and the concentrations of inflammatory factorswere decreased.In rat fracture tissues,BMP-2 overexpression promoted the expression of p-AMPKThr172 protein and bone callus formation,increased bone volume(increased to 22.22%),reduced the number of fibrous components in the cartilage matrix,increased the numbers of osteoblasts and chondrocytes,increased the expression of osteogenic differentiation proteins,and reduced the content of inflammatory factors in the serum.After AICAR intervention,ALP activity and the expression of osteogenic differentiation proteins in BMSCs and fracture tissues further increased,and the level of inflammation decreased.However,the changes in osteogenic differentiation and inflammation levels were significantly reversed after Compound C intervention.Conclusion:BMP-2 activated the AMPK signaling pathway,inhibited the inflammatory response,and effectively promoted the osteogenic differentiation of BMSCs and femoral fracture healing in rats.展开更多
BACKGROUND Colorectal cancer(CRC)ranks among the most prevalent malignant tumors globally.Recent reports suggest that Fusobacterium nucleatum(F.nucleatum)contributes to the initiation,progression,and prognosis of CRC....BACKGROUND Colorectal cancer(CRC)ranks among the most prevalent malignant tumors globally.Recent reports suggest that Fusobacterium nucleatum(F.nucleatum)contributes to the initiation,progression,and prognosis of CRC.Butyrate,a short-chain fatty acid derived from the bacterial fermentation of soluble dietary fiber,is known to inhibit various cancers.This study is designed to explore whether F.nucleatum influences the onset and progression of CRC by impacting the intestinal metabolite butyric acid.AIM To investigate the mechanism by which F.nucleatum affects CRC occurrence and development.METHODS Alterations in the gut microbiota of BALB/c mice were observed following the oral administration of F.nucleatum.Additionally,DLD-1 and HCT116 cell lines were exposed to sodium butyrate(NaB)and F.nucleatum in vitro to examine the effects on proliferative proteins and mitochondrial function.RESULTS Our research indicates that the prevalence of F.nucleatum in fecal samples from CRC patients is significantly greater than in healthy counterparts,while the prevalence of butyrate-producing bacteria is notably lower.In mice colonized with F.nucleatum,the population of butyrate-producing bacteria decreased,resulting in altered levels of butyric acid,a key intestinal metabolite of butyrate.Exposure to NaB can impair mitochondrial morphology and diminish mitochondrial membrane potential in DLD-1 and HCT116 CRC cells.Consequently,this leads to modulated production of adenosine triphosphate and reactive oxygen species,thereby inhibiting cancer cell prolif-eration.Additionally,NaB triggers the adenosine monophosphate-activated protein kinase(AMPK)signaling pathway,blocks the cell cycle in HCT116 and DLD-1 cells,and curtails the proliferation of CRC cells.The combined presence of F.nucleatum and NaB attenuated the effects of the latter.By employing small interfering RNA to suppress AMPK,it was demonstrated that AMPK is essential for NaB’s inhibition of CRC cell proliferation.CONCLUSION F.nucleatum can promote cancer progression through its inhibitory effect on butyric acid,via the AMPK signaling pathway.展开更多
Electroacupuncture improves depressive behavior faster and with fewer adverse effects than antidepressant medication. However, the antidepressant mechanism of electroacupuncture remains poorly understood. Here, we est...Electroacupuncture improves depressive behavior faster and with fewer adverse effects than antidepressant medication. However, the antidepressant mechanism of electroacupuncture remains poorly understood. Here, we established a rat model of chronic unpredicted mild stress, and then treated these rats with electroacupuncture at Yintang （EX-HN3） and Baihui （DU20） with sparse waves at 2 Hz and 0.6 mA for 30 minutes, once a day. We found increased horizontal and vertical activity, and decreased immobility time, at 2 and 4 weeks after treatment. Moreover, levels of neurotransmitters （5-hydroxytryptamine, glutamate, and y-aminobutyric acid） and protein levels of brain-derived neurotrophic factor and brain-derived neurotrophic factor-related proteins （TrkB, protein kinase A, and phosphorylation of cyclic adenosine monophosphate response element binding protein） were increased in the hippocampus. Similarly, protein kinase A and TrkB mRNA levels were increased, and calcium-calmodulin-dependent protein kinase lI levels decreased. These findings suggest that electroacupuncture increases phosphorylation of cyclic adenosine monophosphate response element binding protein and brain-derived neurotrophic factor levels by regulating multiple targets in the cyclic adenosine rnonophosphate response element binding protein signal- ing pathway, thereby promoting nerve regeneration, and exerting an antidepressive effect.展开更多
Objective To investigate the effects and underlying mechanisms of Panax quinquefolium saponin(PQS)on energy deficiency in hypoxia-reperfusion(H/R)induced cardiomyocytes.Methods The H/R injury involved hypoxia for 3 h ...Objective To investigate the effects and underlying mechanisms of Panax quinquefolium saponin(PQS)on energy deficiency in hypoxia-reperfusion(H/R)induced cardiomyocytes.Methods The H/R injury involved hypoxia for 3 h and then reperfusion for 2 h.Cardiomyocytes recruited from neonatal rat ventricular myocytes(NRVMs)were randomly divided into control,H/R,H/R+compound C(C.C),H/R+PQS,and H/R+C.C+PQS groups.BrdU assay,lactase dehydrogenase(LDH)leakage and early apoptosis rate were evaluated to assess cell damages.Contents of high energy phosphate compounds were conducted to detect the energy production.Protein expression levels of adenosine monophosphate-activated protein kinase a(AMPKα),glucose transporter 4(GLUT4),phosphate fructose kinase 2(PFK2),fatty acid translocase/cluster of differentiation 36(FAT/CD36),and acetyl CoA carboxylase 2(ACC2)in the regulatory pathways were measured by Western blotting.Immunofluorescence staining of GLUT4 and FAT/CD36 was used to observe the mobilization of metabolic transporters.Results PQS(50 mg/L)pretreatment significantly alleviated H/R-induced inhibition of NRVMs viability,up-regulation of LDH leakage,acceleration of early apoptosis,and reduction of energy production(P<0.05).Compared with the H/R group,up-regulated expression of AMPKα,GLUT4,PFK2,FAT/CD36 and ACC2 were observed,and more GLUT4 and FAT/CD36 expressions were detected on the membrane in the H/R+PQS group(P<0.05).These effects of PQS on H/R-induced NRVMs were eliminated in the H/R+C.C+PQS group(P<0.05).Conclusion PQS has prominent advantages in protecting NRVMs from H/R-induced cell damages and energy metabolic disorders,by activation of AMPKα-mediated GLUT4-PFK2 and FAT/CD36-ACC2 pathways.展开更多
The immunosuppressive tumor microenvironment(ITM)and low immunogenicity of tumors greatly limit cancer immunotherapy efficacy.The approach of solely depleting regulatory T cells(Tregs)cannot ameliorate ITM,but possibl...The immunosuppressive tumor microenvironment(ITM)and low immunogenicity of tumors greatly limit cancer immunotherapy efficacy.The approach of solely depleting regulatory T cells(Tregs)cannot ameliorate ITM,but possibly worsen it since the produced apoptotic Tregs will activate the A2A signaling pathway and cause more severe immune suppression.To address it,in this work a pH-responsive polymersome(CY/ZM@CS-BPA)based on chondroitin sulfate(CS)-poly(β-amino ester)is rationally developed.In the acidic tumor microenvironment,the tertiary amine groups in the polymersome will reverse from hydrophobic to hydrophilic due to protonation,which leads to the disintegration of nanostructures and the release of cyclophosphamide(CY)and A2A receptor(A2AR)antagonist ZM241385(ZM).CY can selectively deplete Tregs.Additionally,CY can induce immunogenic cell death(ICD)of tumor cells,which results in the proapoptotic translocation of calreticulin to the cell surface,further initiating the antitumor immune responses.ZM can inhibit the activation of the adenosine A2A pathway,subsequently preventing the differentiation of CD4^(+)T cells into Tregs and enhancing the cytotoxicity of CD8+T cells.As a result,the combination of depleting regulatory T cells and blocking the A2A receptor can enhance cancer immunotherapy efficacy.展开更多
文摘BACKGROUND Erianin is a natural bibenzyl compound extracted from Dendrobium chrysotoxum and is known for its anti-inflammatory and antioxidant properties.AIM To explore the possible therapeutic mechanisms of erianin and determine if it can reduce cardiac damage in mice with type 2 diabetes.METHODS High-fat diet and intraperitoneal injections of streptozotocin were used to induce type 2 diabetes mellitus in C57BL/6 mice.Mice were divided into different groups including control,model,and treatment with various doses of erianin(10,20,and 40 mg/kg)as well as ML-385+erianin group.RESULTS Erianin reduced oxidative stress and inflammation and alleviated diabetic cardiomyopathy through the activation of the adenosine monophosphate-acti-vated protein kinase(AMPK)-nuclear factor erythroid 2-related factor 2(Nrf2)-heme oxygenase-1(HO-1)pathway.Treatments with erianin-M and erianin-H promoted weight stabilization and normalized fasting glucose levels relative to diabetic controls.Echocardiographic assessment demonstrated that erianin dose-dependently enhanced left ventricular systolic function(left ventricular ejection fraction,left ventricular fractional shortening)and mitigated ventricular remodeling(left ventricular internal diameter at end-diastole,left ventricular internal diameter at end-systole;P<0.05 vs model group).No significant differences were observed between the ML-385+erianin and placebo-treated groups.Histopathological examination through hematoxylin-eosin staining indicated that erianin ameliorated myocardial fiber fragmentation,structural disorganization,inflammatory cell infiltration,and cytolytic damage.Furthermore,it significantly reduced the serum levels of cardiac troponin I,creatine kinase,and its MB isoenzyme.However,the ML-385+erianin co-treatment failed to alleviate myocardial injury.Metabolic profiling revealed erianin-mediated improvements in glycemic regulation(glycated hemoglobin:P<0.001),plasma insulin homeostasis,and lipid metabolism(total cholesterol,triglycerides,low-density lipo-protein cholesterol reduction,and high-density lipoprotein cholesterol restoration;P<0.05 vs model group).Pro-inflammatory cytokines including tumor necrosis factor-α,interleukin(IL)-1β,and IL-6 were markedly suppressed in the erianin-M and erianin-H groups compared with the model group,whereas no significant differences were detected between the model and ML-385+erianin groups.Oxidative stress parameters showed decreased malondialdehyde levels accompanied by elevated superoxide dismutase and catalase activities in erianin-treated groups,with the most pronounced effects in the erianin-H group(P<0.05).Western blot analysis confirmed the significant upregulation of proteins associated with the AMPK/Nrf2/HO-1 pathway in erianin-M and erianin-H groups.These protective effects were abolished in the ML-385+erianin co-treatment group,which showed no statistical differences from the model group.CONCLUSION Erianin can effectively alleviate myocardial injury in type 2 diabetic mice by activating the AMPK-Nrf2-HO-1 pathway.
基金supported by the Natural Nature Science Foundation of China,Nos.82030071,81874004the Science and Technology Major Project of Changsha,No.kh2103008(all to JZH).
文摘Treatment with metformin can lead to the recovery of pleiotropic biological activities after spinal cord injury.However,its effect on spinal cord injury in aged mice remains unclear.Considering the essential role of angiogenesis during the regeneration process,we hypothesized that metformin activates the adenosine monophosphate-activated protein kinase/endothelial nitric oxide synthase pathway in endothelial cells,thereby promoting microvascular regeneration in aged mice after spinal cord injury.In this study,we established young and aged mouse models of contusive spinal cord injury using a modified Allen method.We found that aging hindered the recovery of neurological function and the formation of blood vessels in the spinal cord.Treatment with metformin promoted spinal cord microvascular endothelial cell migration and blood vessel formation in vitro.Furthermore,intraperitoneal injection of metformin in an in vivo model promoted endothelial cell proliferation and increased the density of new blood vessels in the spinal cord,thereby improving neurological function.The role of metformin was reversed by compound C,an adenosine monophosphate-activated protein kinase inhibitor,both in vivo and in vitro,suggesting that the adenosine monophosphate-activated protein kinase/endothelial nitric oxide synthase pathway likely regulates metformin-mediated angiogenesis after spinal cord injury.These findings suggest that metformin promotes vascular regeneration in the injured spinal cord by activating the adenosine monophosphate-activated protein kinase/endothelial nitric oxide synthase pathway,thereby improving the neurological function of aged mice after spinal cord injury.
基金funded by the Qinghai Province Natural Science Foundation Youth Project Grant No.2022-ZJ-968Q.
文摘Objective:Mesenchymal stem cells(MSCs)are important cells in bone tissue engineering.Bone morphogenetic protein-2(BMP-2)effectively treats bone defects and nonunion.The purpose of this study is to investigate whether BMP-2 promotes bone formation and femoral fracture healing by inhibiting inflammation and promoting osteogenic differentiation of MSCs,in order to provide an experimental basis for developing more efficient fracture treatment strategies.Methods:Bone marrow-derived MSCs(BMSCs)were isolated from rats and treated withOE-BMP-2,the 5′-adenosinemonophosphate-activated protein kinase(AMPK)signal agonist 5-aminoimidazole-4-carboxamide ribonucleotide(AICAR),and the inhibitor Compound C.Osteogenic differentiation was evaluated through an alkaline phosphatase(ALP)kit,Western blot,and Alizarin Red S(ARS)staining.A rat model of femoral fracture was constructed,and fracture healing in the rats was detected by X-ray,microcomputed tomography(CT),and pathological staining.The AMPK signaling pathway and inflammation levels in the BMSCs and fracture model rats were measured by Western blot and enzyme-linked immunosorbent assay(ELISA)kits.Results:After BMP-2 overexpression,the ALP activity in osteogenic BMSCs was significantly increased(increased to 253.64%),the levels of osteogenic differentiation proteins(Osterix and osteocalcin)and p-AMPK Thr172 protein were significantly increased,and the concentrations of inflammatory factorswere decreased.In rat fracture tissues,BMP-2 overexpression promoted the expression of p-AMPKThr172 protein and bone callus formation,increased bone volume(increased to 22.22%),reduced the number of fibrous components in the cartilage matrix,increased the numbers of osteoblasts and chondrocytes,increased the expression of osteogenic differentiation proteins,and reduced the content of inflammatory factors in the serum.After AICAR intervention,ALP activity and the expression of osteogenic differentiation proteins in BMSCs and fracture tissues further increased,and the level of inflammation decreased.However,the changes in osteogenic differentiation and inflammation levels were significantly reversed after Compound C intervention.Conclusion:BMP-2 activated the AMPK signaling pathway,inhibited the inflammatory response,and effectively promoted the osteogenic differentiation of BMSCs and femoral fracture healing in rats.
基金Supported by the Key Discipline of Zhejiang Province in Medical Technology(First Class,Category A)and the Health Project of the Science and Technology Department of Wenzhou,No.Y20220029.
文摘BACKGROUND Colorectal cancer(CRC)ranks among the most prevalent malignant tumors globally.Recent reports suggest that Fusobacterium nucleatum(F.nucleatum)contributes to the initiation,progression,and prognosis of CRC.Butyrate,a short-chain fatty acid derived from the bacterial fermentation of soluble dietary fiber,is known to inhibit various cancers.This study is designed to explore whether F.nucleatum influences the onset and progression of CRC by impacting the intestinal metabolite butyric acid.AIM To investigate the mechanism by which F.nucleatum affects CRC occurrence and development.METHODS Alterations in the gut microbiota of BALB/c mice were observed following the oral administration of F.nucleatum.Additionally,DLD-1 and HCT116 cell lines were exposed to sodium butyrate(NaB)and F.nucleatum in vitro to examine the effects on proliferative proteins and mitochondrial function.RESULTS Our research indicates that the prevalence of F.nucleatum in fecal samples from CRC patients is significantly greater than in healthy counterparts,while the prevalence of butyrate-producing bacteria is notably lower.In mice colonized with F.nucleatum,the population of butyrate-producing bacteria decreased,resulting in altered levels of butyric acid,a key intestinal metabolite of butyrate.Exposure to NaB can impair mitochondrial morphology and diminish mitochondrial membrane potential in DLD-1 and HCT116 CRC cells.Consequently,this leads to modulated production of adenosine triphosphate and reactive oxygen species,thereby inhibiting cancer cell prolif-eration.Additionally,NaB triggers the adenosine monophosphate-activated protein kinase(AMPK)signaling pathway,blocks the cell cycle in HCT116 and DLD-1 cells,and curtails the proliferation of CRC cells.The combined presence of F.nucleatum and NaB attenuated the effects of the latter.By employing small interfering RNA to suppress AMPK,it was demonstrated that AMPK is essential for NaB’s inhibition of CRC cell proliferation.CONCLUSION F.nucleatum can promote cancer progression through its inhibitory effect on butyric acid,via the AMPK signaling pathway.
基金supported by the General Program of the National Natural Science Foundation of China,No.81273847
文摘Electroacupuncture improves depressive behavior faster and with fewer adverse effects than antidepressant medication. However, the antidepressant mechanism of electroacupuncture remains poorly understood. Here, we established a rat model of chronic unpredicted mild stress, and then treated these rats with electroacupuncture at Yintang （EX-HN3） and Baihui （DU20） with sparse waves at 2 Hz and 0.6 mA for 30 minutes, once a day. We found increased horizontal and vertical activity, and decreased immobility time, at 2 and 4 weeks after treatment. Moreover, levels of neurotransmitters （5-hydroxytryptamine, glutamate, and y-aminobutyric acid） and protein levels of brain-derived neurotrophic factor and brain-derived neurotrophic factor-related proteins （TrkB, protein kinase A, and phosphorylation of cyclic adenosine monophosphate response element binding protein） were increased in the hippocampus. Similarly, protein kinase A and TrkB mRNA levels were increased, and calcium-calmodulin-dependent protein kinase lI levels decreased. These findings suggest that electroacupuncture increases phosphorylation of cyclic adenosine monophosphate response element binding protein and brain-derived neurotrophic factor levels by regulating multiple targets in the cyclic adenosine rnonophosphate response element binding protein signal- ing pathway, thereby promoting nerve regeneration, and exerting an antidepressive effect.
基金Supported by the National Natural Science Foundation of China(No.81273934 and No.81874410)。
文摘Objective To investigate the effects and underlying mechanisms of Panax quinquefolium saponin(PQS)on energy deficiency in hypoxia-reperfusion(H/R)induced cardiomyocytes.Methods The H/R injury involved hypoxia for 3 h and then reperfusion for 2 h.Cardiomyocytes recruited from neonatal rat ventricular myocytes(NRVMs)were randomly divided into control,H/R,H/R+compound C(C.C),H/R+PQS,and H/R+C.C+PQS groups.BrdU assay,lactase dehydrogenase(LDH)leakage and early apoptosis rate were evaluated to assess cell damages.Contents of high energy phosphate compounds were conducted to detect the energy production.Protein expression levels of adenosine monophosphate-activated protein kinase a(AMPKα),glucose transporter 4(GLUT4),phosphate fructose kinase 2(PFK2),fatty acid translocase/cluster of differentiation 36(FAT/CD36),and acetyl CoA carboxylase 2(ACC2)in the regulatory pathways were measured by Western blotting.Immunofluorescence staining of GLUT4 and FAT/CD36 was used to observe the mobilization of metabolic transporters.Results PQS(50 mg/L)pretreatment significantly alleviated H/R-induced inhibition of NRVMs viability,up-regulation of LDH leakage,acceleration of early apoptosis,and reduction of energy production(P<0.05).Compared with the H/R group,up-regulated expression of AMPKα,GLUT4,PFK2,FAT/CD36 and ACC2 were observed,and more GLUT4 and FAT/CD36 expressions were detected on the membrane in the H/R+PQS group(P<0.05).These effects of PQS on H/R-induced NRVMs were eliminated in the H/R+C.C+PQS group(P<0.05).Conclusion PQS has prominent advantages in protecting NRVMs from H/R-induced cell damages and energy metabolic disorders,by activation of AMPKα-mediated GLUT4-PFK2 and FAT/CD36-ACC2 pathways.
基金the National Natural Science Foundation of China(Nos.51725303 and 52033007).
文摘The immunosuppressive tumor microenvironment(ITM)and low immunogenicity of tumors greatly limit cancer immunotherapy efficacy.The approach of solely depleting regulatory T cells(Tregs)cannot ameliorate ITM,but possibly worsen it since the produced apoptotic Tregs will activate the A2A signaling pathway and cause more severe immune suppression.To address it,in this work a pH-responsive polymersome(CY/ZM@CS-BPA)based on chondroitin sulfate(CS)-poly(β-amino ester)is rationally developed.In the acidic tumor microenvironment,the tertiary amine groups in the polymersome will reverse from hydrophobic to hydrophilic due to protonation,which leads to the disintegration of nanostructures and the release of cyclophosphamide(CY)and A2A receptor(A2AR)antagonist ZM241385(ZM).CY can selectively deplete Tregs.Additionally,CY can induce immunogenic cell death(ICD)of tumor cells,which results in the proapoptotic translocation of calreticulin to the cell surface,further initiating the antitumor immune responses.ZM can inhibit the activation of the adenosine A2A pathway,subsequently preventing the differentiation of CD4^(+)T cells into Tregs and enhancing the cytotoxicity of CD8+T cells.As a result,the combination of depleting regulatory T cells and blocking the A2A receptor can enhance cancer immunotherapy efficacy.
