Background:To investigate the detailed mechanism underlying the pro-metastatic effect of spleen deficiency(SD)syndrome on hepatocellular carcinoma(HCC).Methods:In the present study,our model was established based on a...Background:To investigate the detailed mechanism underlying the pro-metastatic effect of spleen deficiency(SD)syndrome on hepatocellular carcinoma(HCC).Methods:In the present study,our model was established based on an HCC mouse model induced by diethylnitrosamine using reserpine to induce SD.Exosomes were isolated and purified from mouse plasma samples using an exosome isolation kit.Subsequently,we verified the pro-metastatic effects of exosomes from the HCC mice with SD on HCC cells by transwell assays,wound healing assays,phalloidin staining in vitro,and lung metastasis assay of mice in vivo.Finally,we further explored the detailed mechanism underlying the pro-metastatic effect of exosomes from the HCC mice with SD on HCC cells.Results:We found that SD promoted the malignant progression of HCC in mice.Exosomes from HCC mice with SD enhanced the invasion and metastasis of HCC cells in vitro and in vivo.Mechanistically,upregulation of integrinα1,integrinβ1,and integrinβ5 seemed to play a key role in mediating the pro-metastatic effect of exosomes isolated from the HCC mice with SD,which was largely abrogated upon co-treatment with a broad-spectrum integrin inhibitor.Conclusion:Our findings demonstrated that exosomes promote the invasion and metastasis of HCC cells via an integrin-dependent manner in the spleen-deficient state that would contribute to our better understanding of the role of SD in HCC progression in traditional Chinese medicine,and thus management of the disease.展开更多
Background:The effect of platelet factor 4(PF4)on bone marrow mesenchymal stem cells(BMMSCs)and osteoporosis is poorly understood.Therefore,this study aimed to evaluate the effects of PF4-triggered bone destruction in...Background:The effect of platelet factor 4(PF4)on bone marrow mesenchymal stem cells(BMMSCs)and osteoporosis is poorly understood.Therefore,this study aimed to evaluate the effects of PF4-triggered bone destruction in mice and determine the underlying mechanism.Methods:First,in vitro cell proliferation and cell cycle of BMMSCs were assessed using a CCK8 assay and flow cytometry,respectively.Osteogenic differentiation was confirmed using staining and quantification of alkaline phosphatase and Alizarin Red S.Next,an osteoporotic mouse model was established by performing bilateral ovariectomy(OVX).Furthermore,the PF4 concentrations were obtained using enzymelinked immunosorbent assay.The bone microarchitecture of the femur was evaluated using microCT and histological analyses.Finally,the key regulators of osteogenesis and pathways were investigated using quantitative real-time polymerase chain reaction and Western blotting.Results:Human PF4 widely and moderately decreased the cell proliferation and osteogenic differentiation ability of BMMSCs.Furthermore,the levels of PF4 in the serum and bone marrow were generally increased,whereas bone microarchitecture deteriorated due to OVX.Moreover,in vivo mouse PF4 supplementation triggered bone deterioration of the femur.In addition,several key regulators of osteogenesis were downregulated,and the integrinα5-focal adhesion kinase-extracellular signalregulated kinase(ITGA5-FAK-ERK)pathway was inhibited due to PF4 supplementation.Conclusions:PF4 may be attributed to OVX-i nduced bone loss triggered by the suppression of bone formation in vivo and alleviate BMMSC osteogenic differentiation by inhibiting the ITGA5-FAK-ERK pathway.展开更多
The resistance of cancer cells to the anti-cancer drugs is the most important reason that affecting the efficacy of the non-small cell lung cancer(NSCLC)chemotherapy;thus,to explore the underlyingmechanismof drug resi...The resistance of cancer cells to the anti-cancer drugs is the most important reason that affecting the efficacy of the non-small cell lung cancer(NSCLC)chemotherapy;thus,to explore the underlyingmechanismof drug resistance ofNSCLC medications is urgently needed for improving the therapeutic efficacy of current anti-NSCLC chemotherapies.The aim of the present study is to explore the roles of exosomes in the chemosensitivity of A549 cells and the related mechanism.A549 cells and cisplatin resistant cell line A549/DDP derived exosomes were isolated,and the expressions of CXCR4 were compared.Then,after cisplatin treatment,A549 cells were treated with exosomes,and the proliferation,apoptosis,migration,and invasion of the cells were examined.Finally,the tumorigenic effect of A549/DDP derived exosomes were also evaluated by cisplatin treated xenograft tumor mice models in vivo.We found that A549/DDP derived exosomes increased the proliferation,migration,and invasion,and inhibited the apoptosis and cisplatin sensitivity of A549 cells.CXCR4 was also significantly increased in cells treated with A549/DDP derived exosomes.Furthermore,A549/DDP derived exosomes may also decrease the chemosensitivity of NSCLC cells to cisplatin in vivo.Our data suggested that A549/DDP derived exosomes can affect the chemosensitivity of A549 cells to cisplatin,possibly by transporting CXCR4 to A549 cells.Our data may provide novel evidence for the investigation of drug resistance of NSCLC.展开更多
AIM：To investigate the roles of integrins in choroidal neovascularization（CNV） and their associations with the stromal cell-derived factor-1（SDF-1）/CXCR4 axis.METHODS：CNV lesions were induced in mice using laser...AIM：To investigate the roles of integrins in choroidal neovascularization（CNV） and their associations with the stromal cell-derived factor-1（SDF-1）/CXCR4 axis.METHODS：CNV lesions were induced in mice using laser photocoagulation.After CNV induction,all animals were randomly assigned to：control,SDF-1,SDF-1＋age-related macular degeneration（AMD） 3100（CXCR4 inhibitor）,and SDF-1＋ATN161（integrin α5β1 inhibitor） groups;their effects on CNV progression were observed using hematoxylin eosin（HE） staining,fundus fluorescein angiography（FFA） grading and optical coherence tomography（OCT）,and their effects on CXCR4/integrin α5 expression were evaluated using Western blot and double immunofluorescence staining.Hypoxia-exposed endothelial cells（ECs） were used to simulate CNV in vitro,they were treated with SDF-1,combined with CXCR4 siRNA/AMD3100 or ATN161,and expression of integrin α5,cell migration and tube formation were analyzed.RESULTS：Integrin subunit α5 increased at 3^ rd and 7^ th day and decreased at 14 ^th day in CNV mice,with no significant change of β1-integrin.CXCR4 expression in CNV mice had persistent increase within 14 d after induction.SDF-1 treatment significantly promoted the CNV progression during 3-14 d.The mean CNV length in AMD3100 andATN161 group at day 7 was 270.13 and 264.23 μm in HE images,significantly lower than the mean length in SDF-1（345.70 μm） group.AMD3100 and ATN161 also significantly reduced thickness and leakage of CNV induced by SDF-1.Mean integrin α5 positive area in SDF-1 group reached 2.31×104 μm^2,significantly higher than control（1.25×104 μm^2）,which decreased to 1.78×104 μm^2 after AMD3100 treatment.About 61.36% of ECs in CNV lesions expressed α5 in SDF-1 group,which significantly decreased to 43.12% after AMD3100 treatment.In vitro,integrin α5 peaked by 6 folds after 6 h of hypoxia exposure and CXCR4 gradually increased by up to 2.3 folds after 24 h of hypoxia.Approximately 25.12% of ECs expressed integrin α5 after SDF-1 stimulation,which decreased to 7.2%-9.5% after si-CXCR4 or AMD3100 treatment.ATN161 exerted an inhibitory effect comparable to that of si-CXCR4 on EC migration and tube formation in the presence of SDF-1.CONCLUSION：SDF-1/CXCR4 signaling induces integrin α5β1 expression in ECs to promote CNV.展开更多
Integrins are a family of transmembrane glycoproteins that mediate cell-cell and cell-extracellular matrix interactions. The integrin α4 subunit is widely expressed by cells from the immune system and its expression ...Integrins are a family of transmembrane glycoproteins that mediate cell-cell and cell-extracellular matrix interactions. The integrin α4 subunit is widely expressed by cells from the immune system and its expression by non-hematopoietic cells is scarce. In the present study, gene and protein expression of this integrin subunit was characterized in proliferating and quiescent human RPE cells. Immunofluorescent studies confirm that the α4 subunit is expressed in vitro by RPE cells, a result that has been validated by immunofluorescence and FACS analyses. The accumulation of the α4 integrin at cell-cell junctions in post-confluent RPE cell cultures negatively correlated with the level of expression of the mRNA transcript. Accordingly, transient transfection analyses reveal that the α4 promoter activity is considerably reduced when RPE cells form a confluent monolayer. Moreover, transfection of recombinant constructs bearing 5’-deletions of the α4 promoter segment allows the localization of strong negative regulatory elements on the -76 to -300 region of the α4 gene suggesting that its expression is intimately linked to the proliferative state of primary cultured RPE cells.展开更多
Objective:PD-L1 and PD-L2 expression levels determine immune evasion and the therapeutic efficacy of immune checkpoint blockade.The factors that drive inducible PD-L1 expression have been extensively studied,but mecha...Objective:PD-L1 and PD-L2 expression levels determine immune evasion and the therapeutic efficacy of immune checkpoint blockade.The factors that drive inducible PD-L1 expression have been extensively studied,but mechanisms that result in constitutive PD-L1 expression in cancer cells are largely unknown.Methods:DNA elements were deleted in cells by CRISPR/Cas9-mediated knockout.Protein function was inhibited by chemical inhibitors.Protein levels were examined by Western blot,mRNA levels were examined by real-time RT-PCR,and surface protein expression was determined by cellular immunofluorescence and flow cytometry.Immune evasion was examined by in vitro T cell-mediated killing.Results:We determined the core regions(chr9:5,496,378–5,499,663)of a previously identified PD-L1L2-super-enhancer(SE).Through systematic analysis,we found that the E26 transformation-specific(ETS)variant transcription factor(ETV4)bound to this core DNA region but not to DNA surrounding PD-L1L2SE.Genetic knockout of ETV4 dramatically reduced the expressions of both PD-L1 and PD-L2.ETV4 transcription was dependent on ERK activation,and BRAF/TAK1-induced ERK activation was dependent on extracellular signaling fromαvβ3 integrin,which profoundly affected ETV4 transcription and PD-L1/L2 expression.Genetic silencing or pharmacological inhibition of components of the PD-L1L2-SE-associated pathway rendered cancer cells susceptible to T cell-mediated killing.Conclusions:We identified a pathway originating from the extracellular matrix that signaled via integrin/BRAF/TAK1/ERK/ETV4 to PD-L1L2-SE to induce PD-L1-mediated immune evasion.These results provided new insights into PD-L1L2-SE activation and pathways associated with immune checkpoint regulation in cancer.展开更多
It is imperative to develop and implement newer,more effective strategies to address refractory diabetic wounds.As of now,there is currently no optimal solution for these wounds.Hypoxic human umbilical vein endothelia...It is imperative to develop and implement newer,more effective strategies to address refractory diabetic wounds.As of now,there is currently no optimal solution for these wounds.Hypoxic human umbilical vein endothelial cells(HUVECs)-derived exosomes have been postulated to promote diabetic wound healing,however,its effect and molecular mechanism need further study.In this study,we aimed to investigate whether hypoxic exosomes enhance wound healing in diabetics.Based on our high-throughput sequencing,differentially expressed lncRNAs(including 64 upregulated lncRNAs and 94 downregulated lncRNAs)were found in hypoxic exosomes compared to normoxic exosomes.Interestingly,lncHAR1B was one of the prominently upregulated lncRNAs in hypoxic exosomes,showing a notable correlation with diabetic wound healing.More specifically,hypoxic exosomes were transmitted to surrounding cells,which resulted in a significant increase in lncHAR1B level,thereby relieving the dysfunction of endothelial cells and promoting the switch from M1 to M2 macrophages under high glucose conditions.Mechanistically,lncHAR1B directly interacted with the transcription factor basic helix-loop-helix family member e23(BHLHE23),which subsequently led to its binding to the KLF transcription factor 4(KLF4)and promoted KLF4 expression.In our in vivo experiments,the use of hypoxic exosomes-loaded HGM-QCS hydrogels(Gel-H-Exos)resulted in rapid wound healing compared to that of normoxic exosomes-loaded HGM-QCS hydrogels(Gel-N-Exos)and diabetic groups.Consequently,our study provides potentially novel therapeutic approaches aimed at accelerating wound healing and developing a practical exosomes delivery platform.展开更多
基金This study was funded by the National Science Foundation of China(No.82174173,No.82104962,No.81903967 and No.81873248).
文摘Background:To investigate the detailed mechanism underlying the pro-metastatic effect of spleen deficiency(SD)syndrome on hepatocellular carcinoma(HCC).Methods:In the present study,our model was established based on an HCC mouse model induced by diethylnitrosamine using reserpine to induce SD.Exosomes were isolated and purified from mouse plasma samples using an exosome isolation kit.Subsequently,we verified the pro-metastatic effects of exosomes from the HCC mice with SD on HCC cells by transwell assays,wound healing assays,phalloidin staining in vitro,and lung metastasis assay of mice in vivo.Finally,we further explored the detailed mechanism underlying the pro-metastatic effect of exosomes from the HCC mice with SD on HCC cells.Results:We found that SD promoted the malignant progression of HCC in mice.Exosomes from HCC mice with SD enhanced the invasion and metastasis of HCC cells in vitro and in vivo.Mechanistically,upregulation of integrinα1,integrinβ1,and integrinβ5 seemed to play a key role in mediating the pro-metastatic effect of exosomes isolated from the HCC mice with SD,which was largely abrogated upon co-treatment with a broad-spectrum integrin inhibitor.Conclusion:Our findings demonstrated that exosomes promote the invasion and metastasis of HCC cells via an integrin-dependent manner in the spleen-deficient state that would contribute to our better understanding of the role of SD in HCC progression in traditional Chinese medicine,and thus management of the disease.
基金Beijing Natural Science Foundation,Grant/Award Number:L222145CAMS Innovation Fund for Medical Sciences,Grant/Award Number:2019-I2M-5-038+2 种基金Clinical Medicine Plus X-Young Scholars Project,Peking Universitythe Fundamental Research Funds for the Central Universities,Grant/Award Number:PKU2023LCXQ017National Natural Science Foundation of China,Grant/Award Number:81700935。
文摘Background:The effect of platelet factor 4(PF4)on bone marrow mesenchymal stem cells(BMMSCs)and osteoporosis is poorly understood.Therefore,this study aimed to evaluate the effects of PF4-triggered bone destruction in mice and determine the underlying mechanism.Methods:First,in vitro cell proliferation and cell cycle of BMMSCs were assessed using a CCK8 assay and flow cytometry,respectively.Osteogenic differentiation was confirmed using staining and quantification of alkaline phosphatase and Alizarin Red S.Next,an osteoporotic mouse model was established by performing bilateral ovariectomy(OVX).Furthermore,the PF4 concentrations were obtained using enzymelinked immunosorbent assay.The bone microarchitecture of the femur was evaluated using microCT and histological analyses.Finally,the key regulators of osteogenesis and pathways were investigated using quantitative real-time polymerase chain reaction and Western blotting.Results:Human PF4 widely and moderately decreased the cell proliferation and osteogenic differentiation ability of BMMSCs.Furthermore,the levels of PF4 in the serum and bone marrow were generally increased,whereas bone microarchitecture deteriorated due to OVX.Moreover,in vivo mouse PF4 supplementation triggered bone deterioration of the femur.In addition,several key regulators of osteogenesis were downregulated,and the integrinα5-focal adhesion kinase-extracellular signalregulated kinase(ITGA5-FAK-ERK)pathway was inhibited due to PF4 supplementation.Conclusions:PF4 may be attributed to OVX-i nduced bone loss triggered by the suppression of bone formation in vivo and alleviate BMMSC osteogenic differentiation by inhibiting the ITGA5-FAK-ERK pathway.
基金supported by The Fundamental Research Funds for the Central Universities[No.WK9110000071]Youth Fund of Anhui Cancer Hospital[Nos.2018YJQN019,2020YJQN007].
文摘The resistance of cancer cells to the anti-cancer drugs is the most important reason that affecting the efficacy of the non-small cell lung cancer(NSCLC)chemotherapy;thus,to explore the underlyingmechanismof drug resistance ofNSCLC medications is urgently needed for improving the therapeutic efficacy of current anti-NSCLC chemotherapies.The aim of the present study is to explore the roles of exosomes in the chemosensitivity of A549 cells and the related mechanism.A549 cells and cisplatin resistant cell line A549/DDP derived exosomes were isolated,and the expressions of CXCR4 were compared.Then,after cisplatin treatment,A549 cells were treated with exosomes,and the proliferation,apoptosis,migration,and invasion of the cells were examined.Finally,the tumorigenic effect of A549/DDP derived exosomes were also evaluated by cisplatin treated xenograft tumor mice models in vivo.We found that A549/DDP derived exosomes increased the proliferation,migration,and invasion,and inhibited the apoptosis and cisplatin sensitivity of A549 cells.CXCR4 was also significantly increased in cells treated with A549/DDP derived exosomes.Furthermore,A549/DDP derived exosomes may also decrease the chemosensitivity of NSCLC cells to cisplatin in vivo.Our data suggested that A549/DDP derived exosomes can affect the chemosensitivity of A549 cells to cisplatin,possibly by transporting CXCR4 to A549 cells.Our data may provide novel evidence for the investigation of drug resistance of NSCLC.
基金Supported by the National Natural Science Foundation of China(No.81770936No.81570856+2 种基金No.81670863No.81500748No.81370020)
文摘AIM：To investigate the roles of integrins in choroidal neovascularization（CNV） and their associations with the stromal cell-derived factor-1（SDF-1）/CXCR4 axis.METHODS：CNV lesions were induced in mice using laser photocoagulation.After CNV induction,all animals were randomly assigned to：control,SDF-1,SDF-1＋age-related macular degeneration（AMD） 3100（CXCR4 inhibitor）,and SDF-1＋ATN161（integrin α5β1 inhibitor） groups;their effects on CNV progression were observed using hematoxylin eosin（HE） staining,fundus fluorescein angiography（FFA） grading and optical coherence tomography（OCT）,and their effects on CXCR4/integrin α5 expression were evaluated using Western blot and double immunofluorescence staining.Hypoxia-exposed endothelial cells（ECs） were used to simulate CNV in vitro,they were treated with SDF-1,combined with CXCR4 siRNA/AMD3100 or ATN161,and expression of integrin α5,cell migration and tube formation were analyzed.RESULTS：Integrin subunit α5 increased at 3^ rd and 7^ th day and decreased at 14 ^th day in CNV mice,with no significant change of β1-integrin.CXCR4 expression in CNV mice had persistent increase within 14 d after induction.SDF-1 treatment significantly promoted the CNV progression during 3-14 d.The mean CNV length in AMD3100 andATN161 group at day 7 was 270.13 and 264.23 μm in HE images,significantly lower than the mean length in SDF-1（345.70 μm） group.AMD3100 and ATN161 also significantly reduced thickness and leakage of CNV induced by SDF-1.Mean integrin α5 positive area in SDF-1 group reached 2.31×104 μm^2,significantly higher than control（1.25×104 μm^2）,which decreased to 1.78×104 μm^2 after AMD3100 treatment.About 61.36% of ECs in CNV lesions expressed α5 in SDF-1 group,which significantly decreased to 43.12% after AMD3100 treatment.In vitro,integrin α5 peaked by 6 folds after 6 h of hypoxia exposure and CXCR4 gradually increased by up to 2.3 folds after 24 h of hypoxia.Approximately 25.12% of ECs expressed integrin α5 after SDF-1 stimulation,which decreased to 7.2%-9.5% after si-CXCR4 or AMD3100 treatment.ATN161 exerted an inhibitory effect comparable to that of si-CXCR4 on EC migration and tube formation in the presence of SDF-1.CONCLUSION：SDF-1/CXCR4 signaling induces integrin α5β1 expression in ECs to promote CNV.
文摘Integrins are a family of transmembrane glycoproteins that mediate cell-cell and cell-extracellular matrix interactions. The integrin α4 subunit is widely expressed by cells from the immune system and its expression by non-hematopoietic cells is scarce. In the present study, gene and protein expression of this integrin subunit was characterized in proliferating and quiescent human RPE cells. Immunofluorescent studies confirm that the α4 subunit is expressed in vitro by RPE cells, a result that has been validated by immunofluorescence and FACS analyses. The accumulation of the α4 integrin at cell-cell junctions in post-confluent RPE cell cultures negatively correlated with the level of expression of the mRNA transcript. Accordingly, transient transfection analyses reveal that the α4 promoter activity is considerably reduced when RPE cells form a confluent monolayer. Moreover, transfection of recombinant constructs bearing 5’-deletions of the α4 promoter segment allows the localization of strong negative regulatory elements on the -76 to -300 region of the α4 gene suggesting that its expression is intimately linked to the proliferative state of primary cultured RPE cells.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.81600386,81641164,31770935,and 81873531)the Distinguished Professorship Program of Jiangsu Province to Yihui Fan,the Distinguished Professorship Program of Jiangsu Province to Renfang Mao,and the National Undergraduate Training Programs for Innovation(Grant No.202010304109Y).
文摘Objective:PD-L1 and PD-L2 expression levels determine immune evasion and the therapeutic efficacy of immune checkpoint blockade.The factors that drive inducible PD-L1 expression have been extensively studied,but mechanisms that result in constitutive PD-L1 expression in cancer cells are largely unknown.Methods:DNA elements were deleted in cells by CRISPR/Cas9-mediated knockout.Protein function was inhibited by chemical inhibitors.Protein levels were examined by Western blot,mRNA levels were examined by real-time RT-PCR,and surface protein expression was determined by cellular immunofluorescence and flow cytometry.Immune evasion was examined by in vitro T cell-mediated killing.Results:We determined the core regions(chr9:5,496,378–5,499,663)of a previously identified PD-L1L2-super-enhancer(SE).Through systematic analysis,we found that the E26 transformation-specific(ETS)variant transcription factor(ETV4)bound to this core DNA region but not to DNA surrounding PD-L1L2SE.Genetic knockout of ETV4 dramatically reduced the expressions of both PD-L1 and PD-L2.ETV4 transcription was dependent on ERK activation,and BRAF/TAK1-induced ERK activation was dependent on extracellular signaling fromαvβ3 integrin,which profoundly affected ETV4 transcription and PD-L1/L2 expression.Genetic silencing or pharmacological inhibition of components of the PD-L1L2-SE-associated pathway rendered cancer cells susceptible to T cell-mediated killing.Conclusions:We identified a pathway originating from the extracellular matrix that signaled via integrin/BRAF/TAK1/ERK/ETV4 to PD-L1L2-SE to induce PD-L1-mediated immune evasion.These results provided new insights into PD-L1L2-SE activation and pathways associated with immune checkpoint regulation in cancer.
基金supported by the National Science Foundation of China(No.82272491,No.82072444)Chinese Pharmaceutical Association Hospital Pharmacy department(No.CPA-Z05-ZC-2022-002)Grants from Hubei Province Unveiling Science and Technology Projects(No.2022-35).
文摘It is imperative to develop and implement newer,more effective strategies to address refractory diabetic wounds.As of now,there is currently no optimal solution for these wounds.Hypoxic human umbilical vein endothelial cells(HUVECs)-derived exosomes have been postulated to promote diabetic wound healing,however,its effect and molecular mechanism need further study.In this study,we aimed to investigate whether hypoxic exosomes enhance wound healing in diabetics.Based on our high-throughput sequencing,differentially expressed lncRNAs(including 64 upregulated lncRNAs and 94 downregulated lncRNAs)were found in hypoxic exosomes compared to normoxic exosomes.Interestingly,lncHAR1B was one of the prominently upregulated lncRNAs in hypoxic exosomes,showing a notable correlation with diabetic wound healing.More specifically,hypoxic exosomes were transmitted to surrounding cells,which resulted in a significant increase in lncHAR1B level,thereby relieving the dysfunction of endothelial cells and promoting the switch from M1 to M2 macrophages under high glucose conditions.Mechanistically,lncHAR1B directly interacted with the transcription factor basic helix-loop-helix family member e23(BHLHE23),which subsequently led to its binding to the KLF transcription factor 4(KLF4)and promoted KLF4 expression.In our in vivo experiments,the use of hypoxic exosomes-loaded HGM-QCS hydrogels(Gel-H-Exos)resulted in rapid wound healing compared to that of normoxic exosomes-loaded HGM-QCS hydrogels(Gel-N-Exos)and diabetic groups.Consequently,our study provides potentially novel therapeutic approaches aimed at accelerating wound healing and developing a practical exosomes delivery platform.
