Background Vascular hyporeactivity and leakage are key pathophysiologic features that produce multi-organ damage upon sepsis.We hypothesized that pericytes,a group of pluripotent cells that maintain vascular integrity...Background Vascular hyporeactivity and leakage are key pathophysiologic features that produce multi-organ damage upon sepsis.We hypothesized that pericytes,a group of pluripotent cells that maintain vascular integrity and tension,are protective against sepsis via regulating vascular reactivity and permeability.Methods We conducted a series of in vivo experiments using wild-type(WT),platelet-derived growth factor receptor-β(PDGFR-β)-Cre+mT/mG transgenic mice and Tie2-Cre+Cx43^(flox/flox)mice to examine the relative contribution of pericytes in sepsis,either induced by cecal ligation and puncture(CLP)or lipopolysaccharide(LPS)challenge.In a separate set of experiments with Sprague-Dawley(SD)rats,pericytes were depleted using CP-673451,a selective PDGFR-βinhibitor,at a dosage of 40 mg/(kg·d)for 7 consecutive days.Cultured pericytes,vascular endothelial cells(VECs)and vascular smooth muscle cells(VSMCs)were used for mechanistic investigations.The effects of pericytes and pericyte-derived microvesicles(PCMVs)and candidate miRNAs on vascular reactivity and barrier function were also examined.Results CLP and LPS induced severe injury/loss of pericytes,vascular hyporeactivity and leakage(P<0.05).Transplantation with exogenous pericytes protected vascular reactivity and barrier function via microvessel colonization(P<0.05).Cx43 knockout in either pericytes or VECs reduced pericyte colonization in microvessels(P<0.05).Additionally,PCMVs transferred miR-145 and miR-132 to VSMCs and VECs,respectively,exerting a protective effect on vascular reactivity and barrier function after sepsis(P<0.05).miR-145 primarily improved the contractile response of VSMCs by activating the sphingosine kinase 2(Sphk2)/sphingosine-1-phosphate receptor(S1PR)1/phosphorylation of myosin light chain 20 pathway,whereas miR-132 effectively improved the barrier function of VECs by activating the Sphk2/S1PR2/zonula occludens-1 and vascular endothelial-cadherin pathways.Conclusions Pericytes are protective against sepsis through regulating vascular reactivity and barrier function.Possible mechanisms include both direct colonization of microvasculature and secretion of PCMVs.展开更多
Pericytes are the main cellular components of tiny arteries and capillaries.Studies have found that pericytes can undergo morphological contraction or relaxation under stimulation by cytokines,thus affecting the contr...Pericytes are the main cellular components of tiny arteries and capillaries.Studies have found that pericytes can undergo morphological contraction or relaxation under stimulation by cytokines,thus affecting the contraction and relaxation of microvessels and playing an essential role in regulating vascular microcirculation.Moreover,due to the characteristics of stem cells,pericytes can differentiate into a variety of inflammatory cell phenotypes,which then affect the immune function.Additionally,pericytes can also participate in angiogenesis and wound healing by interacting with endothelial cells in vascular microcirculation disorders.Here we review the origin,biological phenotype and function of pericytes,and discuss the potential mechanisms of pericytes in vascular microcirculation disorders,especially in pulmonary hypertension,so as to provide a sound basis and direction for the prevention and treatment of vascular microcirculation diseases.展开更多
Objective:Immature vasculature lacking pericyte coverage substantially contributes to tumor growth,drug resistance,and cancer cell dissemination.We previously demonstrated that tumor necrosis factor superfamily 15(TNF...Objective:Immature vasculature lacking pericyte coverage substantially contributes to tumor growth,drug resistance,and cancer cell dissemination.We previously demonstrated that tumor necrosis factor superfamily 15(TNFSF15)is a cytokine with important roles in modulating hematopoiesis and vascular homeostasis.The main purpose of this study was to explore whether TNFSF15 might promote freshly isolated myeloid cells to differentiate into CD11b^(+) cells and further into pericytes.Methods:A model of Lewis lung cancer was established in mice with red fluorescent bone marrow.After TNFSF15 treatment,CD11b^(+) myeloid cells and vascular pericytes in the tumors,and the co-localization of pericytes and vascular endothelial cells,were assessed.Additionally,CD11b^(+) cells were isolated from wild-type mice and treated with TNFSF15 to determine the effects on the differentiation of these cells.Results:We observed elevated percentages of bone marrow-derived CD11b^(+)myeloid cells and vascular pericytes in TNFSF15-treated tumors,and the latter cells co-localized with vascular endothelial cells.TNFSF15 protected against CD11b^(+)cell apoptosis and facilitated the differentiation of these cells into pericytes by down-regulating Wnt3a-VEGFR1 and up-regulating CD49e-FN signaling pathways.Conclusions:TNFSF15 facilitates the production of CD11b^(+) cells in the bone marrow and promotes the differentiation of these cells into pericytes,which may stabilize the tumor neovasculature.展开更多
Pericytes are classically defined as contra ctile cells within the central nervous system that regulate blood flow and permeability of the blood-brain barrier(BBB).This one-sided view is gradually changing,and pericyt...Pericytes are classically defined as contra ctile cells within the central nervous system that regulate blood flow and permeability of the blood-brain barrier(BBB).This one-sided view is gradually changing,and pericytes are now considered versatile cells that can switch their function in response to different stimuli(Uemura et al.,2020).In addition to their role as gatekeepers of the BBB and maintaining homeostasis of the brain’s microenvironment through adj usting the vascular intraluminal dia meter,pericytes are both sensors and initiators of inflammation.展开更多
Pericytes,as the mural cells surrounding the microvasculature,play a critical role in the regulation of microcirculation;however,how these cells respond to ischemic stroke remains unclear.To determine the temporal alt...Pericytes,as the mural cells surrounding the microvasculature,play a critical role in the regulation of microcirculation;however,how these cells respond to ischemic stroke remains unclear.To determine the temporal alterations in pericytes after ischemia/reperfusion,we used the 1-hour middle cerebral artery occlusion model,which was examined at 2,12,and 24 hours after reperfusion.Our results showed that in the reperfused regions,the cerebral blood flow decreased and the infarct volume increased with time.Furthermore,the pericytes in the infarct regions contracted and acted on the vascular endothelial cells within 24 hours after reperfusion.These effects may result in incomplete microcirculation reperfusion and a gradual worsening trend with time in the acute phase.These findings provide strong evidence for explaining the“no-reflow”phenomenon that occurs after recanalization in clinical practice.展开更多
To examine whether hypoxia exerts effect on the expression of basic fibroblast growth ac- tor (bFGF) in pulmonary vascular pericytes (PC), cell culture, in .citu hybridization with probe of digoxigenin-11-dUTP-labled ...To examine whether hypoxia exerts effect on the expression of basic fibroblast growth ac- tor (bFGF) in pulmonary vascular pericytes (PC), cell culture, in .citu hybridization with probe of digoxigenin-11-dUTP-labled cDNA, immunocytochemistry and image analysis were employed in this study. The results showed that the expression amount of bFGF mRNA and protein in PC of hypoxia (H) group was 1.31 times (P<0. 01) and 1. 17 times (P<0. 01) that of normoxia (N) group re- spectively. It suggests that hypoxia can directly enhance the expression of bFGF mRNA and protein in PC. Increased expression of bFGF may play an important role in the process of PC proliferation and differentiation of PC into smooth muscle-like cells.展开更多
Background:Pericytes are contractile cells that wrap along the walls of capillaries.In the brain,pericytes play a crucial role in the regulation of capillary diameter and vascular blood flow in response to metabolic d...Background:Pericytes are contractile cells that wrap along the walls of capillaries.In the brain,pericytes play a crucial role in the regulation of capillary diameter and vascular blood flow in response to metabolic demand.The contribution of pericytes to microvascular deficits in glaucoma is currently unknown.To address this,we used two-photon excitation microscopy for longitudinal monitoring of retinal pericytes and capillaries in a mouse glaucoma model.Methods:Ocular hypertension was induced by injection of magnetic microbeads into the anterior chamber of albino mice expressing red fluorescent protein selectively in pericytes(NG2-DsRed).Minimally invasive,multiphoton imaging through the sclera of live NG2-DsRed mice was used to visualize pericytes and capillary diameter at one,two and three weeks after glaucoma induction.In vivo fluctuations in pericyte intracellular calcium were monitored with the calcium indicator Fluo-4.Ex vivo stereological analysis of retinal tissue prior to and after injection of microbeads was used to confirm our in vivo findings.Results:Live two-photon imaging of NG2-DsRed retinas demonstrated that ocular hypertension induced progressive accumulation of intracellular calcium in pericytes.Calcium uptake correlated directly with the narrowing of capillaries in the superficial,inner,and outer vascular plexuses(capillary diameter:naïve control=4.7±0.1μm,glaucoma=4.0±0.1μm,n=5-6 mice/group,Student’s t-test P<0.05).Frequency distribution analysis showed a substantial increase in the number of small-diameter capillaries(≤3μm)and a decrease in larger-diameter microvessels(≥5-9μm)at three weeks after induction of ocular hypertension(n=5-6 mice/group,Student’s t-test P<0.05).Conclusions:Our data support two main conclusions.First,two-photon excitation microscopy is an effective strategy to monitor longitudinal changes in retinal pericytes and capillaries in live animals at glaucoma onset and progression.Second,ocular hypertension triggers rapid intracellular calcium increase in retinal pericytes leading to substantial capillary constriction.This study identifies retinal pericytes as important mediators of early microvascular dysfunction in glaucoma.展开更多
Over the last ten years or so,it has become apparent that pericytes have the potential to differentiate into other cell types which may help in the repair and regeneration of tissue after injury.In fact,pericytes have...Over the last ten years or so,it has become apparent that pericytes have the potential to differentiate into other cell types which may help in the repair and regeneration of tissue after injury.In fact,pericytes have been described as a precursor to mesenchymal stem cells.Their location at the interface between the microvasculature and the brain parenchyma means they are ideally positioned to initiate repair and regeneration in response to various factors.In this perspective,we will highlight how pericytes have stem cell potential alongside their role in regulating processes,such as angiogenesis and inflammation,and discuss how pericytes could be harnessed to promote tissue repair in the brain(Figure 1).展开更多
Vascular regeneration is a challenging topic in tissue repair. As one of the important components of the neurovascular unit(NVU),pericytes play an essential role in the maintenance of the vascular network of the spina...Vascular regeneration is a challenging topic in tissue repair. As one of the important components of the neurovascular unit(NVU),pericytes play an essential role in the maintenance of the vascular network of the spinal cord. To date, subtypes of pericytes have been identified by various markers, namely the PDGFR-β, Desmin, CD146, and NG2, each of which is involved with spinal cord injury(SCI) repair. In addition, pericytes may act as a stem cell source that is important for bone development and regeneration, whilst specific subtypes of pericyte could facilitate bone fracture and defect repair. One of the major challenges of pericyte biology is to determine the specific markers that would clearly distinguish the different subtypes of pericytes, and to develop efficient approaches to isolate and propagate pericytes. In this review, we discuss the biology and roles of pericytes, their markers for identification, and cell differentiation capacity with a focus on the potential application in the treatment of SCI and bone diseases in orthopedics.展开更多
In order to study the effects of 1-(2,6-dimethylphenoxy)-2-(3,4-dimethoxyphenylethylamino) propane hydrochloride (DDPH) on proliferation and immunophenotypes of newborn rat pulmonary vascular pericytes induced by hypo...In order to study the effects of 1-(2,6-dimethylphenoxy)-2-(3,4-dimethoxyphenylethylamino) propane hydrochloride (DDPH) on proliferation and immunophenotypes of newborn rat pulmonary vascular pericytes induced by hypoxic endothelial cell conditioned medium (HECCM) from porcine pulmonary arteries, the cultured pericytes were divided into 4 groups according to the endothelial cell conditioned medium (ECCM) used: normoxic ECCM (NECCM) group, NECCM+DDPH group, HECCM group and HECCM+DDPH group. Cell culture, immunocytochemical staining, image analysis and flow cytometric method were used to investigate the effects of HECCM and DDPH on the expression of α-smooth muscle actin (α-SM-Actin) antigen, CD34 antigen, S-100 antigen and proliferating cell nuclear antigen (PCNA) and cell cycle in pericytes. The results showed that the α-SM-Actin antigen in the pericytes in HECCM group was stronger positively expressed than in the other three groups, but CD34 antigen and S-100 antigen were negatively expressed. The expression of α-SM-Actin antigen, CD34 antigen and S-100 antigen was positive in the groups of NECCM, NECCM+DDPH and HECCM+DDPH; The expression of α-SM-Actin and PCNA in HECCM group was 1.32 times (P<0.01) and 1.24 times (P<0.05) that in NECCM group, 1.30 times (P<0.01) and 1.21 times (P<0.05) that in HECCM+DDPH group, respectively. The percentage of the cells in the GO-G1 phase in the HECCM group was lower by 11.7 % and 9.1 %, in S phase higher by 5.6 % and 4.2 %, in G2-M phase higher by 6.1 % and 4.9 % than in the groups of NECCM,HECCM+DDPH, respectively. The inhibitory rate of DDPH on the increased α-SM-Actin and PCNA syntheses in pericytes induced by HECCM were 23.4 % and 17.1 % respectively. The inhibitory rate on the increased pericytes from GO-G1 phase to S phase was 8.3 %. These results suggest that DDPH can directly inhibit pericytes from proliferation and immunophenotypical transformation of smooth muscle-like cells induced by HECCM.展开更多
Microvascular dysfunction has been implicated in many diseases such as stroke and diabetes.In addition to the microvascular endothelial cell(EC),the pericyte,a perivascular cell that adheres to the abluminal side of t...Microvascular dysfunction has been implicated in many diseases such as stroke and diabetes.In addition to the microvascular endothelial cell(EC),the pericyte,a perivascular cell that adheres to the abluminal side of the EC may also be important to ensure proper microvascular function.As a prominent perivascular cell,the pericyte has garnered increasing attention for its multiple functional aspects,especially the pericyte of central nervous system(Yemisci et al.,2009;Armulik et al.,2010;Gaceb et al.,2018).展开更多
Human osteogenic progenitors are not precisely defined,being primarily studied as heterogeneous multipotent cell populations and termed mesenchymal stem cells(MSCs).Notably,select human pericytes can develop into bone...Human osteogenic progenitors are not precisely defined,being primarily studied as heterogeneous multipotent cell populations and termed mesenchymal stem cells(MSCs).Notably,select human pericytes can develop into bone-forming osteoblasts.Here,we sought to define the differentiation potential of CD146 f human pericytes from skeletal and soft tissue sources,with the underlying goal of defining cell surface markers that typify an osteoblastogenic pericyte.CD146+CD31~CD45_pericytes were derived by fluorescence-activated cell sorting from human periosteum,adipose,or dermal tissue.Periosteal CD146+CD31—CD45 cells retained canonical features of pericytes/MSC.Periosteal pericytes demonstrated a striking tendency to undergo osteoblastogenesis in vitro and skeletogenesis in vivo,while soft tissue pericytes did not readily.Transcriptome analysis revealed higher CXCR4 signaling among periosteal pericytes in comparison to their soft tissue counterparts,and CXCR4 chemical inhibition abrogated ectopic ossification by periosteal pericytes.Conversely,enrichment of CXCR4+pericytes or stromal cells identified an osteoblastic/non-adipocytic precursor cell.In sum,human skeletal and soft tissue pericytes differ in their basal abilities to form bone.Diversity exists in soft tissue pericytes,however,and CXCR4+pericytes represent an osteoblastogenic,non-adipocytic cell precursor.Indeed,enrichment for CXCR4-expressing stromal cells is a potential new tactic for skeletal tissue engineering.展开更多
To study the effect of c myc antisense oligodeoxynucleotides (ODNs) on proliferation of pulmonary vascular pericytes (PC) induced by hypoxia, cell culture, dot hybridization using probe of digoxigenin 11 dUTP labeled ...To study the effect of c myc antisense oligodeoxynucleotides (ODNs) on proliferation of pulmonary vascular pericytes (PC) induced by hypoxia, cell culture, dot hybridization using probe of digoxigenin 11 dUTP labeled cDNA, 3H thymidine incorporation, immunocytochemical technique and image analysis methods were used to observe the effect of c myc antisense ODNs on expression of c myc gene and proliferating cell nuclear antigen (PCNA), and 3H thymidine incorporation of PC induced by hypoxia. The results showed that hypoxia could significantly enhance the expression of c myc and PCNA ( P <0.01), and elevate 3H thymidine incorporation of PC ( P <0.01), but antisense ODNs could significantly inhibit the expression of c myc and PCNA ( P <0.05), and 3H thymidine incorporation of PC ( P <0.01). It was suggested that hypoxia could promote the proliferation of PC by up regulating the expression of c myc gene, but c myc antisense ODNs could inhibit hypoxia induced proliferation of PC by downregulating the expression of c myc gene.展开更多
Background:Pericytes are contractile cells that wrap along the walls of capillaries.In the brain,pericytes play a crucial role in the regulation of capillary diameter and vascular blood flow in response to metabolic d...Background:Pericytes are contractile cells that wrap along the walls of capillaries.In the brain,pericytes play a crucial role in the regulation of capillary diameter and vascular blood flow in response to metabolic demand.During ischemia,it has been suggested that pericytes may constrict capillaries,and that pericytes remain constricted after reperfusion thus resulting in impaired blood flow.Methods:Here,we used a mouse model of retinal ischemia based on ligation of the central retinal artery to characterize the role of pericytes on capillary constriction.Ischemia was induced in transgenic mice carrying the NG2 promoter driving red fluorescent protein expression to selectively visualize pericytes(line NG2:DsRed).Changes in retinal capillary diameter at 1 hr after ischemia were measured ex vivo in whole-mounted retinas from ischemic and control eyes(n=4-6/group)using a stereological approach.Vessels and pericytes were three-dimensionally reconstructed using IMARIS(Bitplane).Furthermore,we used a novel and minimally invasive two-photon microscopy approach that allowed live imaging of microvasculature changes in the retina.Results:Our data show a generalized reduction in capillary diameter in ischemic retinas relative to sham-operated controls in all vascular plexus(ischemia:4.7±0.2μm,control:5.2±0.2µm,student’s t-test,P<0.001).Analysis of the number of capillary constrictions at pericyte locations,visualized in NG2:DsRed mice,demonstrated a substantial increase in ischemic retinas relative to the physiological capillary diameter reductions observed in controls(ischemia:1,038±277 constrictions at pericyte locations,control:60±36 constrictions at pericyte locations,student’s t-test,P<0.01).Live imaging using two-photon microscopy confirmed robust capillary constriction at the level of pericytes on retinal capillaries during ischemia(n=6-8/group).Conclusions:Collectively,our data demonstrate that ischemia promotes rapid pericyte constriction on retinal capillaries causing major microvascular dysfunction in this tissue.To identify the molecular mechanisms underlying the pathological response of pericytes during ischemia,we are currently carrying out experiments in mice and zebrafish to modulate signaling pathways involved in calcium dynamics leading to contractility in these cells.展开更多
Blood vessels constitute a closed pipe system distributed throughout the body,transporting blood from the heart to other organs and delivering metabolic waste products back to the lungs and kidneys.Changes in blood ve...Blood vessels constitute a closed pipe system distributed throughout the body,transporting blood from the heart to other organs and delivering metabolic waste products back to the lungs and kidneys.Changes in blood vessels are related to many disorders like stroke,myocardial infarction,aneurysm,and diabetes,which are important causes of death worldwide.Translational research for new appro-aches to disease modeling and effective treatment is needed due to the huge socio-economic burden on healthcare systems.Although mice or rats have been widely used,applying data from animal studies to human-specific vascular physiology and pathology is difficult.The rise of induced pluripotent stem cells(iPSCs)provides a reliable in vitro resource for disease modeling,regenerative medicine,and drug discovery because they carry all human genetic information and have the ability to directionally differentiate into any type of human cells.This review summarizes the latest progress from the establishment of iPSCs,the strategies for differentiating iPSCs into vascular cells,and the in vivo trans-plantation of these vascular derivatives.It also introduces the application of these technologies in disease modeling,drug screening,and regenerative medicine.Additionally,the application of high-tech tools,such as omics analysis and high-throughput sequencing,in this field is reviewed.展开更多
The brain pericyte is a unique and indispensable part of the blood-brain barrier(BBB),and contributes to several pathological processes in traumatic brain injury(TBI).However,the cellular and molecular mechanisms by w...The brain pericyte is a unique and indispensable part of the blood-brain barrier(BBB),and contributes to several pathological processes in traumatic brain injury(TBI).However,the cellular and molecular mechanisms by which pericytes are regulated in the damaged brain are largely unknown.Here,we show that the formation of neutrophil extracellular traps(NETs)induces the appearance of CD11b^(+)pericytes after TBI.These CD11b^(+)pericyte subsets are characterized by increased permeability and pro-inflammatory profiles compared to CD11b-pericytes.Moreover,histones from NETs by Dectin-1 facilitate CD11b induction in brain pericytes in PKC-c-Jun dependent manner,resulting in neuroinflammation and BBB dysfunction after TBI.These data indicate that neutrophil-NET-pericyte and histone-Dectin-1-CD11b are possible mechanisms for the activation and dysfunction of pericytes.Targeting NETs formation and Dectin-1 are promising means of treating TBI.展开更多
The blood-brain barrier is a unique property of central nervous system blood vessels that protects sensitive central nervous system cells from potentially harmful blood components.The mechanistic basis of this barrier...The blood-brain barrier is a unique property of central nervous system blood vessels that protects sensitive central nervous system cells from potentially harmful blood components.The mechanistic basis of this barrier is found at multiple levels,including the adherens and tight junction proteins that tightly bind adjacent endothelial cells and the influence of neighboring pericytes,microglia,and astrocyte endfeet.In addition,extracellular matrix components of the vascular basement membrane play a critical role in establishing and maintaining blood-brain barrier integrity,not only by providing an adhesive substrate for blood-brain barrier cells to adhere to,but also by providing guidance cues that strongly influence vascular cell behavior.The extracellular matrix protein laminin is one of the most abundant components of the basement membrane,and several lines of evidence suggest that it plays a key role in directing blood-brain barrier behavior.In this review,we describe the basic structure of laminin and its receptors,the expression patterns of these molecules in central nervous system blood vessels and how they are altered in disease states,and most importantly,how genetic deletion of different laminin isoforms or their receptors reveals the contribution of these molecules to blood-brain barrier function and integrity.Finally,we discuss some of the important unanswered questions in the field and provide a“to-do”list of some of the critical outstanding experiments.展开更多
Over the past two decades considerable progress has been made in understanding the ototoxic effects and mechanisms underlying loop diuretics. As typical representative of loop diuretics ethacrynic acid or furosemide o...Over the past two decades considerable progress has been made in understanding the ototoxic effects and mechanisms underlying loop diuretics. As typical representative of loop diuretics ethacrynic acid or furosemide only induces temporary hearing loss, but rarely permanent deafness unless applied in severe acute or chronic renal failure or with other ototoxic drugs. Loop diuretic induce unique pathological changes in the cochlea such as formation of edematous spaces in the epithelium of the stria vascularis, which leads to rapid decrease of the endolymphatic potential and eventual loss of the cochlear microphonic potential, summating potential, and compound action potential. Loop diuretics interfere with strial adenylate cyclase and Nat/Kt-ATPase and inhibit the Na-K-2Cl cotransporter in the stria vascularis, however recent reports indicate that one of the earliest effects in vivo is to abolish blood flow in the vessels supplying the lateral wall. Since ethacrynic acid does not damage the stria vascularis in vitro, the changes in Nat/Kt-ATPase and Na-K-2Cl seen in vivo may be secondary effects results from strial ischemia and anoxia. Recent observations showing that renin is present in pericytes surrounding stria arterioles suggest that diuretics may induce local vasoconstriction by renin secretion and angiotensin formation. The tight junctions in the blood-cochlea barrier prevent toxic molecules and pathogens from entering cochlea, but when diuretics induce a transient ischemia, the barrier is temporarily disrupted allowing the entry of toxic chemicals or pathogens.展开更多
基金supported by the Key Projects and Innovation Group of National Natural Science Foundation of China(81830065),the Innovation Groups of NSFC(81721001),and the Young Scientists Fund(82102279).
文摘Background Vascular hyporeactivity and leakage are key pathophysiologic features that produce multi-organ damage upon sepsis.We hypothesized that pericytes,a group of pluripotent cells that maintain vascular integrity and tension,are protective against sepsis via regulating vascular reactivity and permeability.Methods We conducted a series of in vivo experiments using wild-type(WT),platelet-derived growth factor receptor-β(PDGFR-β)-Cre+mT/mG transgenic mice and Tie2-Cre+Cx43^(flox/flox)mice to examine the relative contribution of pericytes in sepsis,either induced by cecal ligation and puncture(CLP)or lipopolysaccharide(LPS)challenge.In a separate set of experiments with Sprague-Dawley(SD)rats,pericytes were depleted using CP-673451,a selective PDGFR-βinhibitor,at a dosage of 40 mg/(kg·d)for 7 consecutive days.Cultured pericytes,vascular endothelial cells(VECs)and vascular smooth muscle cells(VSMCs)were used for mechanistic investigations.The effects of pericytes and pericyte-derived microvesicles(PCMVs)and candidate miRNAs on vascular reactivity and barrier function were also examined.Results CLP and LPS induced severe injury/loss of pericytes,vascular hyporeactivity and leakage(P<0.05).Transplantation with exogenous pericytes protected vascular reactivity and barrier function via microvessel colonization(P<0.05).Cx43 knockout in either pericytes or VECs reduced pericyte colonization in microvessels(P<0.05).Additionally,PCMVs transferred miR-145 and miR-132 to VSMCs and VECs,respectively,exerting a protective effect on vascular reactivity and barrier function after sepsis(P<0.05).miR-145 primarily improved the contractile response of VSMCs by activating the sphingosine kinase 2(Sphk2)/sphingosine-1-phosphate receptor(S1PR)1/phosphorylation of myosin light chain 20 pathway,whereas miR-132 effectively improved the barrier function of VECs by activating the Sphk2/S1PR2/zonula occludens-1 and vascular endothelial-cadherin pathways.Conclusions Pericytes are protective against sepsis through regulating vascular reactivity and barrier function.Possible mechanisms include both direct colonization of microvasculature and secretion of PCMVs.
基金Program of Fundamental Research Funds for the Central Universities,Grant/Award Number:22120220562Program of Natural Science Foundation of Shanghai,Grant/Award Number:201409004100 and 21ZR1453800+1 种基金Three Year Action Plan to Promote Clinical Skills and Clinical Innovation in Municipal Hospitals,Grant/Award Number:SHDC2020CR6016-002 and SHDC2020CR4021Program of Shanghai Pulmonary Hospital,Grant/Award Number:fkzr2320 and FKLY20005。
文摘Pericytes are the main cellular components of tiny arteries and capillaries.Studies have found that pericytes can undergo morphological contraction or relaxation under stimulation by cytokines,thus affecting the contraction and relaxation of microvessels and playing an essential role in regulating vascular microcirculation.Moreover,due to the characteristics of stem cells,pericytes can differentiate into a variety of inflammatory cell phenotypes,which then affect the immune function.Additionally,pericytes can also participate in angiogenesis and wound healing by interacting with endothelial cells in vascular microcirculation disorders.Here we review the origin,biological phenotype and function of pericytes,and discuss the potential mechanisms of pericytes in vascular microcirculation disorders,especially in pulmonary hypertension,so as to provide a sound basis and direction for the prevention and treatment of vascular microcirculation diseases.
基金supported partly by the National Natural Science Foundation of China(Grant Nos.82073064 and 81874167 to LYL,and 82073233 to ZQZ)Haihe Laboratory of Cell Ecosystem Innovation Fund(Grant No.22HHXBSS00020 to LYL)Ministry of Education 111 Project(Grant No.B20016 to LYL)。
文摘Objective:Immature vasculature lacking pericyte coverage substantially contributes to tumor growth,drug resistance,and cancer cell dissemination.We previously demonstrated that tumor necrosis factor superfamily 15(TNFSF15)is a cytokine with important roles in modulating hematopoiesis and vascular homeostasis.The main purpose of this study was to explore whether TNFSF15 might promote freshly isolated myeloid cells to differentiate into CD11b^(+) cells and further into pericytes.Methods:A model of Lewis lung cancer was established in mice with red fluorescent bone marrow.After TNFSF15 treatment,CD11b^(+) myeloid cells and vascular pericytes in the tumors,and the co-localization of pericytes and vascular endothelial cells,were assessed.Additionally,CD11b^(+) cells were isolated from wild-type mice and treated with TNFSF15 to determine the effects on the differentiation of these cells.Results:We observed elevated percentages of bone marrow-derived CD11b^(+)myeloid cells and vascular pericytes in TNFSF15-treated tumors,and the latter cells co-localized with vascular endothelial cells.TNFSF15 protected against CD11b^(+)cell apoptosis and facilitated the differentiation of these cells into pericytes by down-regulating Wnt3a-VEGFR1 and up-regulating CD49e-FN signaling pathways.Conclusions:TNFSF15 facilitates the production of CD11b^(+) cells in the bone marrow and promotes the differentiation of these cells into pericytes,which may stabilize the tumor neovasculature.
基金Neurological Foundation First Fellowship(2244 FFE)(to TJS)Health Research Council Hercus(21/034)+1 种基金a Neurologicalgrant(2026PRG)School of Medical Science,University of Auckland(to BVD)。
文摘Pericytes are classically defined as contra ctile cells within the central nervous system that regulate blood flow and permeability of the blood-brain barrier(BBB).This one-sided view is gradually changing,and pericytes are now considered versatile cells that can switch their function in response to different stimuli(Uemura et al.,2020).In addition to their role as gatekeepers of the BBB and maintaining homeostasis of the brain’s microenvironment through adj usting the vascular intraluminal dia meter,pericytes are both sensors and initiators of inflammation.
基金financially supported by the China Academy of Chinese Medical Sciences Innovation Fund,No.CI2021A03407(to WZB)the National Natural Science Foundation of China,No.81973789(to FFC).
文摘Pericytes,as the mural cells surrounding the microvasculature,play a critical role in the regulation of microcirculation;however,how these cells respond to ischemic stroke remains unclear.To determine the temporal alterations in pericytes after ischemia/reperfusion,we used the 1-hour middle cerebral artery occlusion model,which was examined at 2,12,and 24 hours after reperfusion.Our results showed that in the reperfused regions,the cerebral blood flow decreased and the infarct volume increased with time.Furthermore,the pericytes in the infarct regions contracted and acted on the vascular endothelial cells within 24 hours after reperfusion.These effects may result in incomplete microcirculation reperfusion and a gradual worsening trend with time in the acute phase.These findings provide strong evidence for explaining the“no-reflow”phenomenon that occurs after recanalization in clinical practice.
基金This project was supported by the grant of the NationalNature Sciences Foundation of China (No. 39570289).
文摘To examine whether hypoxia exerts effect on the expression of basic fibroblast growth ac- tor (bFGF) in pulmonary vascular pericytes (PC), cell culture, in .citu hybridization with probe of digoxigenin-11-dUTP-labled cDNA, immunocytochemistry and image analysis were employed in this study. The results showed that the expression amount of bFGF mRNA and protein in PC of hypoxia (H) group was 1.31 times (P<0. 01) and 1. 17 times (P<0. 01) that of normoxia (N) group re- spectively. It suggests that hypoxia can directly enhance the expression of bFGF mRNA and protein in PC. Increased expression of bFGF may play an important role in the process of PC proliferation and differentiation of PC into smooth muscle-like cells.
文摘Background:Pericytes are contractile cells that wrap along the walls of capillaries.In the brain,pericytes play a crucial role in the regulation of capillary diameter and vascular blood flow in response to metabolic demand.The contribution of pericytes to microvascular deficits in glaucoma is currently unknown.To address this,we used two-photon excitation microscopy for longitudinal monitoring of retinal pericytes and capillaries in a mouse glaucoma model.Methods:Ocular hypertension was induced by injection of magnetic microbeads into the anterior chamber of albino mice expressing red fluorescent protein selectively in pericytes(NG2-DsRed).Minimally invasive,multiphoton imaging through the sclera of live NG2-DsRed mice was used to visualize pericytes and capillary diameter at one,two and three weeks after glaucoma induction.In vivo fluctuations in pericyte intracellular calcium were monitored with the calcium indicator Fluo-4.Ex vivo stereological analysis of retinal tissue prior to and after injection of microbeads was used to confirm our in vivo findings.Results:Live two-photon imaging of NG2-DsRed retinas demonstrated that ocular hypertension induced progressive accumulation of intracellular calcium in pericytes.Calcium uptake correlated directly with the narrowing of capillaries in the superficial,inner,and outer vascular plexuses(capillary diameter:naïve control=4.7±0.1μm,glaucoma=4.0±0.1μm,n=5-6 mice/group,Student’s t-test P<0.05).Frequency distribution analysis showed a substantial increase in the number of small-diameter capillaries(≤3μm)and a decrease in larger-diameter microvessels(≥5-9μm)at three weeks after induction of ocular hypertension(n=5-6 mice/group,Student’s t-test P<0.05).Conclusions:Our data support two main conclusions.First,two-photon excitation microscopy is an effective strategy to monitor longitudinal changes in retinal pericytes and capillaries in live animals at glaucoma onset and progression.Second,ocular hypertension triggers rapid intracellular calcium increase in retinal pericytes leading to substantial capillary constriction.This study identifies retinal pericytes as important mediators of early microvascular dysfunction in glaucoma.
文摘Over the last ten years or so,it has become apparent that pericytes have the potential to differentiate into other cell types which may help in the repair and regeneration of tissue after injury.In fact,pericytes have been described as a precursor to mesenchymal stem cells.Their location at the interface between the microvasculature and the brain parenchyma means they are ideally positioned to initiate repair and regeneration in response to various factors.In this perspective,we will highlight how pericytes have stem cell potential alongside their role in regulating processes,such as angiogenesis and inflammation,and discuss how pericytes could be harnessed to promote tissue repair in the brain(Figure 1).
基金partly supported by a research grant from the National Natural Science Funding of China (82172424,81972150,82172428)Zhejiang Medical and Health Science,and Technology Plan Project (2021KY212)supported in part by the Australian Health and Medical Research Council (NHMRC,No. 1107828)
文摘Vascular regeneration is a challenging topic in tissue repair. As one of the important components of the neurovascular unit(NVU),pericytes play an essential role in the maintenance of the vascular network of the spinal cord. To date, subtypes of pericytes have been identified by various markers, namely the PDGFR-β, Desmin, CD146, and NG2, each of which is involved with spinal cord injury(SCI) repair. In addition, pericytes may act as a stem cell source that is important for bone development and regeneration, whilst specific subtypes of pericyte could facilitate bone fracture and defect repair. One of the major challenges of pericyte biology is to determine the specific markers that would clearly distinguish the different subtypes of pericytes, and to develop efficient approaches to isolate and propagate pericytes. In this review, we discuss the biology and roles of pericytes, their markers for identification, and cell differentiation capacity with a focus on the potential application in the treatment of SCI and bone diseases in orthopedics.
文摘In order to study the effects of 1-(2,6-dimethylphenoxy)-2-(3,4-dimethoxyphenylethylamino) propane hydrochloride (DDPH) on proliferation and immunophenotypes of newborn rat pulmonary vascular pericytes induced by hypoxic endothelial cell conditioned medium (HECCM) from porcine pulmonary arteries, the cultured pericytes were divided into 4 groups according to the endothelial cell conditioned medium (ECCM) used: normoxic ECCM (NECCM) group, NECCM+DDPH group, HECCM group and HECCM+DDPH group. Cell culture, immunocytochemical staining, image analysis and flow cytometric method were used to investigate the effects of HECCM and DDPH on the expression of α-smooth muscle actin (α-SM-Actin) antigen, CD34 antigen, S-100 antigen and proliferating cell nuclear antigen (PCNA) and cell cycle in pericytes. The results showed that the α-SM-Actin antigen in the pericytes in HECCM group was stronger positively expressed than in the other three groups, but CD34 antigen and S-100 antigen were negatively expressed. The expression of α-SM-Actin antigen, CD34 antigen and S-100 antigen was positive in the groups of NECCM, NECCM+DDPH and HECCM+DDPH; The expression of α-SM-Actin and PCNA in HECCM group was 1.32 times (P<0.01) and 1.24 times (P<0.05) that in NECCM group, 1.30 times (P<0.01) and 1.21 times (P<0.05) that in HECCM+DDPH group, respectively. The percentage of the cells in the GO-G1 phase in the HECCM group was lower by 11.7 % and 9.1 %, in S phase higher by 5.6 % and 4.2 %, in G2-M phase higher by 6.1 % and 4.9 % than in the groups of NECCM,HECCM+DDPH, respectively. The inhibitory rate of DDPH on the increased α-SM-Actin and PCNA syntheses in pericytes induced by HECCM were 23.4 % and 17.1 % respectively. The inhibitory rate on the increased pericytes from GO-G1 phase to S phase was 8.3 %. These results suggest that DDPH can directly inhibit pericytes from proliferation and immunophenotypical transformation of smooth muscle-like cells induced by HECCM.
基金This work was supported by the National Heart,Lung,and Blood Institute R01HL143432(to JC).
文摘Microvascular dysfunction has been implicated in many diseases such as stroke and diabetes.In addition to the microvascular endothelial cell(EC),the pericyte,a perivascular cell that adheres to the abluminal side of the EC may also be important to ensure proper microvascular function.As a prominent perivascular cell,the pericyte has garnered increasing attention for its multiple functional aspects,especially the pericyte of central nervous system(Yemisci et al.,2009;Armulik et al.,2010;Gaceb et al.,2018).
基金A.WJ.was supported by the NIH/NIAMS(R01 AR070773,K08 AR068316),NIH/NIDCR(R21 DE027922)Department of Defense(W81XWH-18-1-0121,W81XWH-18-1-0336,W81XWH-18-10613)+1 种基金American Cancer Society(Research Scholar Grant,RSG-18-027-01-CSM)the Maryland Stem Cell Research Foundation,and the Musculoskeletal Transplant Foundation.The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute of Health,Department of Defense,or US Army.We thank the JHU microscopy facility,JHMI deep sequencing and microarray core facility,and Hao Zhang within the JHU Bloomberg Flow Cytometry and Immunology Core for their technical assistance.
文摘Human osteogenic progenitors are not precisely defined,being primarily studied as heterogeneous multipotent cell populations and termed mesenchymal stem cells(MSCs).Notably,select human pericytes can develop into bone-forming osteoblasts.Here,we sought to define the differentiation potential of CD146 f human pericytes from skeletal and soft tissue sources,with the underlying goal of defining cell surface markers that typify an osteoblastogenic pericyte.CD146+CD31~CD45_pericytes were derived by fluorescence-activated cell sorting from human periosteum,adipose,or dermal tissue.Periosteal CD146+CD31—CD45 cells retained canonical features of pericytes/MSC.Periosteal pericytes demonstrated a striking tendency to undergo osteoblastogenesis in vitro and skeletogenesis in vivo,while soft tissue pericytes did not readily.Transcriptome analysis revealed higher CXCR4 signaling among periosteal pericytes in comparison to their soft tissue counterparts,and CXCR4 chemical inhibition abrogated ectopic ossification by periosteal pericytes.Conversely,enrichment of CXCR4+pericytes or stromal cells identified an osteoblastic/non-adipocytic precursor cell.In sum,human skeletal and soft tissue pericytes differ in their basal abilities to form bone.Diversity exists in soft tissue pericytes,however,and CXCR4+pericytes represent an osteoblastogenic,non-adipocytic cell precursor.Indeed,enrichment for CXCR4-expressing stromal cells is a potential new tactic for skeletal tissue engineering.
基金This project was supported by a grant from the National Natural Sciences Foundation of China(No.395 70 2 89) .
文摘To study the effect of c myc antisense oligodeoxynucleotides (ODNs) on proliferation of pulmonary vascular pericytes (PC) induced by hypoxia, cell culture, dot hybridization using probe of digoxigenin 11 dUTP labeled cDNA, 3H thymidine incorporation, immunocytochemical technique and image analysis methods were used to observe the effect of c myc antisense ODNs on expression of c myc gene and proliferating cell nuclear antigen (PCNA), and 3H thymidine incorporation of PC induced by hypoxia. The results showed that hypoxia could significantly enhance the expression of c myc and PCNA ( P <0.01), and elevate 3H thymidine incorporation of PC ( P <0.01), but antisense ODNs could significantly inhibit the expression of c myc and PCNA ( P <0.05), and 3H thymidine incorporation of PC ( P <0.01). It was suggested that hypoxia could promote the proliferation of PC by up regulating the expression of c myc gene, but c myc antisense ODNs could inhibit hypoxia induced proliferation of PC by downregulating the expression of c myc gene.
文摘Background:Pericytes are contractile cells that wrap along the walls of capillaries.In the brain,pericytes play a crucial role in the regulation of capillary diameter and vascular blood flow in response to metabolic demand.During ischemia,it has been suggested that pericytes may constrict capillaries,and that pericytes remain constricted after reperfusion thus resulting in impaired blood flow.Methods:Here,we used a mouse model of retinal ischemia based on ligation of the central retinal artery to characterize the role of pericytes on capillary constriction.Ischemia was induced in transgenic mice carrying the NG2 promoter driving red fluorescent protein expression to selectively visualize pericytes(line NG2:DsRed).Changes in retinal capillary diameter at 1 hr after ischemia were measured ex vivo in whole-mounted retinas from ischemic and control eyes(n=4-6/group)using a stereological approach.Vessels and pericytes were three-dimensionally reconstructed using IMARIS(Bitplane).Furthermore,we used a novel and minimally invasive two-photon microscopy approach that allowed live imaging of microvasculature changes in the retina.Results:Our data show a generalized reduction in capillary diameter in ischemic retinas relative to sham-operated controls in all vascular plexus(ischemia:4.7±0.2μm,control:5.2±0.2µm,student’s t-test,P<0.001).Analysis of the number of capillary constrictions at pericyte locations,visualized in NG2:DsRed mice,demonstrated a substantial increase in ischemic retinas relative to the physiological capillary diameter reductions observed in controls(ischemia:1,038±277 constrictions at pericyte locations,control:60±36 constrictions at pericyte locations,student’s t-test,P<0.01).Live imaging using two-photon microscopy confirmed robust capillary constriction at the level of pericytes on retinal capillaries during ischemia(n=6-8/group).Conclusions:Collectively,our data demonstrate that ischemia promotes rapid pericyte constriction on retinal capillaries causing major microvascular dysfunction in this tissue.To identify the molecular mechanisms underlying the pathological response of pericytes during ischemia,we are currently carrying out experiments in mice and zebrafish to modulate signaling pathways involved in calcium dynamics leading to contractility in these cells.
文摘Blood vessels constitute a closed pipe system distributed throughout the body,transporting blood from the heart to other organs and delivering metabolic waste products back to the lungs and kidneys.Changes in blood vessels are related to many disorders like stroke,myocardial infarction,aneurysm,and diabetes,which are important causes of death worldwide.Translational research for new appro-aches to disease modeling and effective treatment is needed due to the huge socio-economic burden on healthcare systems.Although mice or rats have been widely used,applying data from animal studies to human-specific vascular physiology and pathology is difficult.The rise of induced pluripotent stem cells(iPSCs)provides a reliable in vitro resource for disease modeling,regenerative medicine,and drug discovery because they carry all human genetic information and have the ability to directionally differentiate into any type of human cells.This review summarizes the latest progress from the establishment of iPSCs,the strategies for differentiating iPSCs into vascular cells,and the in vivo trans-plantation of these vascular derivatives.It also introduces the application of these technologies in disease modeling,drug screening,and regenerative medicine.Additionally,the application of high-tech tools,such as omics analysis and high-throughput sequencing,in this field is reviewed.
基金This work was supported by the National Natural Science Foundation of China(32000670 and 82071779)Chongqing Research Program of Basic Research and Frontier Technology(cstc2017jcyjAX0338).
文摘The brain pericyte is a unique and indispensable part of the blood-brain barrier(BBB),and contributes to several pathological processes in traumatic brain injury(TBI).However,the cellular and molecular mechanisms by which pericytes are regulated in the damaged brain are largely unknown.Here,we show that the formation of neutrophil extracellular traps(NETs)induces the appearance of CD11b^(+)pericytes after TBI.These CD11b^(+)pericyte subsets are characterized by increased permeability and pro-inflammatory profiles compared to CD11b-pericytes.Moreover,histones from NETs by Dectin-1 facilitate CD11b induction in brain pericytes in PKC-c-Jun dependent manner,resulting in neuroinflammation and BBB dysfunction after TBI.These data indicate that neutrophil-NET-pericyte and histone-Dectin-1-CD11b are possible mechanisms for the activation and dysfunction of pericytes.Targeting NETs formation and Dectin-1 are promising means of treating TBI.
文摘The blood-brain barrier is a unique property of central nervous system blood vessels that protects sensitive central nervous system cells from potentially harmful blood components.The mechanistic basis of this barrier is found at multiple levels,including the adherens and tight junction proteins that tightly bind adjacent endothelial cells and the influence of neighboring pericytes,microglia,and astrocyte endfeet.In addition,extracellular matrix components of the vascular basement membrane play a critical role in establishing and maintaining blood-brain barrier integrity,not only by providing an adhesive substrate for blood-brain barrier cells to adhere to,but also by providing guidance cues that strongly influence vascular cell behavior.The extracellular matrix protein laminin is one of the most abundant components of the basement membrane,and several lines of evidence suggest that it plays a key role in directing blood-brain barrier behavior.In this review,we describe the basic structure of laminin and its receptors,the expression patterns of these molecules in central nervous system blood vessels and how they are altered in disease states,and most importantly,how genetic deletion of different laminin isoforms or their receptors reveals the contribution of these molecules to blood-brain barrier function and integrity.Finally,we discuss some of the important unanswered questions in the field and provide a“to-do”list of some of the critical outstanding experiments.
基金supported in part by a grant from National Natural Science Foundation of China 81470706a grant from Guangdong Natural Science Foundation No 2015A030313180
文摘Over the past two decades considerable progress has been made in understanding the ototoxic effects and mechanisms underlying loop diuretics. As typical representative of loop diuretics ethacrynic acid or furosemide only induces temporary hearing loss, but rarely permanent deafness unless applied in severe acute or chronic renal failure or with other ototoxic drugs. Loop diuretic induce unique pathological changes in the cochlea such as formation of edematous spaces in the epithelium of the stria vascularis, which leads to rapid decrease of the endolymphatic potential and eventual loss of the cochlear microphonic potential, summating potential, and compound action potential. Loop diuretics interfere with strial adenylate cyclase and Nat/Kt-ATPase and inhibit the Na-K-2Cl cotransporter in the stria vascularis, however recent reports indicate that one of the earliest effects in vivo is to abolish blood flow in the vessels supplying the lateral wall. Since ethacrynic acid does not damage the stria vascularis in vitro, the changes in Nat/Kt-ATPase and Na-K-2Cl seen in vivo may be secondary effects results from strial ischemia and anoxia. Recent observations showing that renin is present in pericytes surrounding stria arterioles suggest that diuretics may induce local vasoconstriction by renin secretion and angiotensin formation. The tight junctions in the blood-cochlea barrier prevent toxic molecules and pathogens from entering cochlea, but when diuretics induce a transient ischemia, the barrier is temporarily disrupted allowing the entry of toxic chemicals or pathogens.
