Integrins are a highly complex family of receptors that, when expressed on the surface of cells, can mediate reciprocal cell-to-cell and cell-to-extracellular matrix(ECM) interactions leading to assembly of integrin a...Integrins are a highly complex family of receptors that, when expressed on the surface of cells, can mediate reciprocal cell-to-cell and cell-to-extracellular matrix(ECM) interactions leading to assembly of integrin adhesion complexes(IACs) that initiate many signaling functions both at the membrane and deeper within the cytoplasm to coordinate processes including cell adhesion, migration, proliferation, survival, differentiation, and metabolism. All metazoan organisms possess integrins, and it is generally agreed that integrins were associated with the evolution of multicellularity, being essential for the association of cells with their neighbors and surroundings, during embryonic development and many aspects of cellular and molecular biology. Integrins have important roles in many aspects of embryonic development, normal physiology, and disease processes with a multitude of functions discovered and elucidated for integrins that directly influence many areas of biology and medicine, including mammalian pregnancy, in particular implantation of the blastocyst to the uterine wall, subsequent placentation and conceptus(embryo/fetus and associated placental membranes) development. This review provides a succinct overview of integrin structure, ligand binding, and signaling followed with a concise overview of embryonic development, implantation, and early placentation in pigs, sheep, humans, and mice as an example for rodents. A brief timeline of the initial localization of integrin subunits to the uterine luminal epithelium(LE) and conceptus trophoblast is then presented, followed by sequential summaries of integrin expression and function during gestation in pigs, sheep, humans, and rodents. As appropriate for this journal, summaries of integrin expression and function during gestation in pigs and sheep are in depth, whereas summaries for humans and rodents are brief. Because similar models to those illustrated in Fig. 1, 2, 3, 4, 5 and 6 are present throughout the scientific literature, the illustrations in this manuscript are drafted as Viking imagery for entertainment purposes.展开更多
Objective Cardiac fibroblasts(CFs)proliferation and extracellular matrix deposition are important features of cardiac fibrosis.Various studies have indicated that vitamin D displays an anti-fibrotic property in chroni...Objective Cardiac fibroblasts(CFs)proliferation and extracellular matrix deposition are important features of cardiac fibrosis.Various studies have indicated that vitamin D displays an anti-fibrotic property in chronic heart diseases.This study explored the role of vitamin D in the growth of CFs via an integrin signaling pathway.Methods MTT and 5-ethynyl-2′-deoxyuridine assays were performed to determine cell viability.Western blotting was performed to detect the expression of proliferating cell nuclear antigen(PCNA)and integrin signaling pathway.The fibronectin was observed by ELISA.Immunohistochemical staining was employed to evaluate the expression of integrinβ3.Results The PCNA expression in the CFs was enhanced after isoproterenol(ISO)stimulation accompanied by an elevated expression of integrin beta-3(β3).The blockade of the integrinβ3 with a specific integrinβ3 antibody reduced the PCNA expression induced by the ISO.Decreasing the integrinβ3 by siRNA reduced the ISO-triggered phosphorylation of FAK and Akt.Both the FAK inhibitor and Akt inhibitor suppressed the PCNA expression induced by the ISO in the CFs.Calcitriol(CAL),an active form of vitamin D,attenuated the ISO-induced CFs proliferation by downregulating the integrinβ3 expression,and phosphorylation of FAK and Akt.Moreover,CAL reduced the increased levels of fibronectin and hydroxyproline in the CFs culture medium triggered by the ISO.The administration of calcitriol decreased the integrinβ3 expression in the ISO-induced myocardial injury model.Conclusion These findings revealed a novel role for CAL in suppressing the CFs growth by the downregulation of the integrinβ3/FAK/Akt pathway.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
BACKGROUND Umbilical cord(UC)mesenchymal stem cell(MSC)transplantation is a potential therapeutic intervention for atherosclerotic vascular disease.Integrin beta 3(ITGB3)promotes cell migration in several cell types.H...BACKGROUND Umbilical cord(UC)mesenchymal stem cell(MSC)transplantation is a potential therapeutic intervention for atherosclerotic vascular disease.Integrin beta 3(ITGB3)promotes cell migration in several cell types.However,whether ITGBmodified MSCs can migrate to plaque sites in vivo and play an anti-atherosclerotic role remains unclear.AIM To investigate whether ITGB3-overexpressing MSCs(MSCs^(ITGB3))would exhibit improved homing efficacy in atherosclerosis.METHODS UC MSCs were isolated and expanded.Lentiviral vectors encoding ITGB3 or green fluorescent protein(GFP)as control were transfected into MSCs.Sixty male apolipoprotein E-/-mice were acquired from Beijing Vital River Lab Animal Technology Co.,Ltd and fed with a high-fat diet(HFD)for 12 wk to induce the formation of atherosclerotic lesions.These HFD-fed mice were randomly separated into three clusters.GFP-labeled MSCs(MSCs^(GFP))or MSCs^(ITGB3)were transplanted into the mice intravenously via the tail vein.Immunofluorescence staining,Oil red O staining,histological analyses,western blotting,enzymelinked immunosorbent assay,and quantitative real-time polymerase chain reaction were used for the analyses.RESULTS ITGB3 modified MSCs successfully differentiated into the“osteocyte”and“adipocyte”phenotypes and were characterized by positive expression(>91.3%)of CD29,CD73,and CD105 and negative expression(<1.35%)of CD34 and Human Leukocyte Antigen-DR.In a transwell assay,MSCs^(ITGB3)showed significantly faster migration than MSCsGFP.ITGB3 overexpression had no effects on MSC viability,differentiation,and secretion.Immunofluorescence staining revealed that ITGB3 overexpression substantially enhanced the homing of MSCs to plaque sites.Oil red O staining and histological analyses further confirmed the therapeutic effects of MSCs^(ITGB3),significantly reducing the plaque area.Enzyme-linked immunosorbent assay and quantitative real-time polymerase chain reaction revealed that MSC^(ITGB3)transplantation considerably decreased the inflammatory response in pathological tissues by improving the dynamic equilibrium of pro-and anti-inflammatory cytokines.CONCLUSION These results showed that ITGB3 overexpression enhanced the MSC homing ability,providing a potential approach for MSC delivery to plaque sites,thereby optimizing their therapeutic effects.展开更多
Neovascularization and angiogenesis in the brain are important physiological processes for normal brain development and repair/regeneration following insults. Integrins are cell surface adhesion receptors mediating im...Neovascularization and angiogenesis in the brain are important physiological processes for normal brain development and repair/regeneration following insults. Integrins are cell surface adhesion receptors mediating important function of cells such as survival, growth and development during tissue organization, differentiation and organogenesis. In this study, we used an integrin-binding array platform to identify the important types of integrins and their binding peptides that facilitate adhesion, growth, development, and vascular-like network formation of rat primary brain microvascular endothelial cells. Brain microvascular endothelial cells were isolated from rat brain on post-natal day 7. Cells were cultured in a custom-designed integrin array system containing short synthetic peptides binding to 16 types of integrins commonly expressed on cells in vertebrates. After 7 days of culture, the brain microvascular endothelial cells were processed for immunostaining with markers for endothelial cells including von Willibrand factor and platelet endothelial cell adhesion molecule. 5-Bromo-2′-dexoyuridine was added to the culture at 48 hours prior to fixation to assess cell proliferation. Among 16 integrins tested, we found that α5β1, αvβ5 and αvβ8 greatly promoted proliferation of endothelial cells in culture. To investigate the effect of integrin-binding peptides in promoting neovascularization and angiogenesis, the binding peptides to the above three types of integrins were immobilized to our custom-designed hydrogel in three-dimensional(3 D) culture of brain microvascular endothelial cells with the addition of vascular endothelial growth factor. Following a 7-day 3 D culture, the culture was fixed and processed for double labeling of phalloidin with von Willibrand factor or platelet endothelial cell adhesion molecule and assessed under confocal microscopy. In the 3 D culture in hydrogels conjugated with the integrin-binding peptide, brain microvascular endothelial cells formed interconnected vascular-like network with clearly discernable lumens, which is reminiscent of brain microvascular network in vivo. With the novel integrin-binding array system, we identified the specific types of integrins on brain microvascular endothelial cells that mediate cell adhesion and growth followed by functionalizing a 3 D hydrogel culture system using the binding peptides that specifically bind to the identified integrins, leading to robust growth and lumenized microvascular-like network formation of brain microvascular endothelial cells in 3 D culture. This technology can be used for in vitro and in vivo vascularization of transplants or brain lesions to promote brain tissue regeneration following neurological insults.展开更多
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
基金supported by USDA-NRICGP 98-35203-6337 to FWB.and RCB,NRSA DHHS/NIH 1-F32-HDO 8501 O1A1 to GAJ,USDA-NRI 2006-35203-17199 to GAJ and Kayla J.BaylessUSDA National Institute of Food and Agriculture Research Initiative Competitive Fellowship Grant no.2012-67011-19892 to James W.Frank and GAJ+1 种基金Agriculture and Food Research Initiative Competitive Grant no.2016-67015-24955 from the USDA National Institute of Food and Agriculture to GAJ and FWBNational Institutes of Health Grant 1R21HD071468-01 to GAJ and KJB。
文摘Integrins are a highly complex family of receptors that, when expressed on the surface of cells, can mediate reciprocal cell-to-cell and cell-to-extracellular matrix(ECM) interactions leading to assembly of integrin adhesion complexes(IACs) that initiate many signaling functions both at the membrane and deeper within the cytoplasm to coordinate processes including cell adhesion, migration, proliferation, survival, differentiation, and metabolism. All metazoan organisms possess integrins, and it is generally agreed that integrins were associated with the evolution of multicellularity, being essential for the association of cells with their neighbors and surroundings, during embryonic development and many aspects of cellular and molecular biology. Integrins have important roles in many aspects of embryonic development, normal physiology, and disease processes with a multitude of functions discovered and elucidated for integrins that directly influence many areas of biology and medicine, including mammalian pregnancy, in particular implantation of the blastocyst to the uterine wall, subsequent placentation and conceptus(embryo/fetus and associated placental membranes) development. This review provides a succinct overview of integrin structure, ligand binding, and signaling followed with a concise overview of embryonic development, implantation, and early placentation in pigs, sheep, humans, and mice as an example for rodents. A brief timeline of the initial localization of integrin subunits to the uterine luminal epithelium(LE) and conceptus trophoblast is then presented, followed by sequential summaries of integrin expression and function during gestation in pigs, sheep, humans, and rodents. As appropriate for this journal, summaries of integrin expression and function during gestation in pigs and sheep are in depth, whereas summaries for humans and rodents are brief. Because similar models to those illustrated in Fig. 1, 2, 3, 4, 5 and 6 are present throughout the scientific literature, the illustrations in this manuscript are drafted as Viking imagery for entertainment purposes.
基金supported by grants from the National Natural Science Foundation of China(No.81441016)and Key R&D Plan in Shaanxi Province of China(No.2020SF-262 and No.2019SF-200).
文摘Objective Cardiac fibroblasts(CFs)proliferation and extracellular matrix deposition are important features of cardiac fibrosis.Various studies have indicated that vitamin D displays an anti-fibrotic property in chronic heart diseases.This study explored the role of vitamin D in the growth of CFs via an integrin signaling pathway.Methods MTT and 5-ethynyl-2′-deoxyuridine assays were performed to determine cell viability.Western blotting was performed to detect the expression of proliferating cell nuclear antigen(PCNA)and integrin signaling pathway.The fibronectin was observed by ELISA.Immunohistochemical staining was employed to evaluate the expression of integrinβ3.Results The PCNA expression in the CFs was enhanced after isoproterenol(ISO)stimulation accompanied by an elevated expression of integrin beta-3(β3).The blockade of the integrinβ3 with a specific integrinβ3 antibody reduced the PCNA expression induced by the ISO.Decreasing the integrinβ3 by siRNA reduced the ISO-triggered phosphorylation of FAK and Akt.Both the FAK inhibitor and Akt inhibitor suppressed the PCNA expression induced by the ISO in the CFs.Calcitriol(CAL),an active form of vitamin D,attenuated the ISO-induced CFs proliferation by downregulating the integrinβ3 expression,and phosphorylation of FAK and Akt.Moreover,CAL reduced the increased levels of fibronectin and hydroxyproline in the CFs culture medium triggered by the ISO.The administration of calcitriol decreased the integrinβ3 expression in the ISO-induced myocardial injury model.Conclusion These findings revealed a novel role for CAL in suppressing the CFs growth by the downregulation of the integrinβ3/FAK/Akt pathway.
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National Natural Science Foundation of China,No.82100301Key Science and Technology Research Program of Hebei Provincial Department of Health,No,20221014.
文摘BACKGROUND Umbilical cord(UC)mesenchymal stem cell(MSC)transplantation is a potential therapeutic intervention for atherosclerotic vascular disease.Integrin beta 3(ITGB3)promotes cell migration in several cell types.However,whether ITGBmodified MSCs can migrate to plaque sites in vivo and play an anti-atherosclerotic role remains unclear.AIM To investigate whether ITGB3-overexpressing MSCs(MSCs^(ITGB3))would exhibit improved homing efficacy in atherosclerosis.METHODS UC MSCs were isolated and expanded.Lentiviral vectors encoding ITGB3 or green fluorescent protein(GFP)as control were transfected into MSCs.Sixty male apolipoprotein E-/-mice were acquired from Beijing Vital River Lab Animal Technology Co.,Ltd and fed with a high-fat diet(HFD)for 12 wk to induce the formation of atherosclerotic lesions.These HFD-fed mice were randomly separated into three clusters.GFP-labeled MSCs(MSCs^(GFP))or MSCs^(ITGB3)were transplanted into the mice intravenously via the tail vein.Immunofluorescence staining,Oil red O staining,histological analyses,western blotting,enzymelinked immunosorbent assay,and quantitative real-time polymerase chain reaction were used for the analyses.RESULTS ITGB3 modified MSCs successfully differentiated into the“osteocyte”and“adipocyte”phenotypes and were characterized by positive expression(>91.3%)of CD29,CD73,and CD105 and negative expression(<1.35%)of CD34 and Human Leukocyte Antigen-DR.In a transwell assay,MSCs^(ITGB3)showed significantly faster migration than MSCsGFP.ITGB3 overexpression had no effects on MSC viability,differentiation,and secretion.Immunofluorescence staining revealed that ITGB3 overexpression substantially enhanced the homing of MSCs to plaque sites.Oil red O staining and histological analyses further confirmed the therapeutic effects of MSCs^(ITGB3),significantly reducing the plaque area.Enzyme-linked immunosorbent assay and quantitative real-time polymerase chain reaction revealed that MSC^(ITGB3)transplantation considerably decreased the inflammatory response in pathological tissues by improving the dynamic equilibrium of pro-and anti-inflammatory cytokines.CONCLUSION These results showed that ITGB3 overexpression enhanced the MSC homing ability,providing a potential approach for MSC delivery to plaque sites,thereby optimizing their therapeutic effects.
基金supported by NIH grant RO1 NS093985 (to DS, NZ, XW) and RO1 NS101955 (to DS)the VCU Microscopy Facility,supported,in part,by funding from NIH-NCI Cancer Center Support Grant P30 CA016059。
文摘Neovascularization and angiogenesis in the brain are important physiological processes for normal brain development and repair/regeneration following insults. Integrins are cell surface adhesion receptors mediating important function of cells such as survival, growth and development during tissue organization, differentiation and organogenesis. In this study, we used an integrin-binding array platform to identify the important types of integrins and their binding peptides that facilitate adhesion, growth, development, and vascular-like network formation of rat primary brain microvascular endothelial cells. Brain microvascular endothelial cells were isolated from rat brain on post-natal day 7. Cells were cultured in a custom-designed integrin array system containing short synthetic peptides binding to 16 types of integrins commonly expressed on cells in vertebrates. After 7 days of culture, the brain microvascular endothelial cells were processed for immunostaining with markers for endothelial cells including von Willibrand factor and platelet endothelial cell adhesion molecule. 5-Bromo-2′-dexoyuridine was added to the culture at 48 hours prior to fixation to assess cell proliferation. Among 16 integrins tested, we found that α5β1, αvβ5 and αvβ8 greatly promoted proliferation of endothelial cells in culture. To investigate the effect of integrin-binding peptides in promoting neovascularization and angiogenesis, the binding peptides to the above three types of integrins were immobilized to our custom-designed hydrogel in three-dimensional(3 D) culture of brain microvascular endothelial cells with the addition of vascular endothelial growth factor. Following a 7-day 3 D culture, the culture was fixed and processed for double labeling of phalloidin with von Willibrand factor or platelet endothelial cell adhesion molecule and assessed under confocal microscopy. In the 3 D culture in hydrogels conjugated with the integrin-binding peptide, brain microvascular endothelial cells formed interconnected vascular-like network with clearly discernable lumens, which is reminiscent of brain microvascular network in vivo. With the novel integrin-binding array system, we identified the specific types of integrins on brain microvascular endothelial cells that mediate cell adhesion and growth followed by functionalizing a 3 D hydrogel culture system using the binding peptides that specifically bind to the identified integrins, leading to robust growth and lumenized microvascular-like network formation of brain microvascular endothelial cells in 3 D culture. This technology can be used for in vitro and in vivo vascularization of transplants or brain lesions to promote brain tissue regeneration following neurological insults.
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.
