Advances in the differentiation of pluripotent stem cells into vascular cells

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.

Inhibition of viability of human retinal microvascular endothelial cells by vialinin A under high glucose condition

AIM:To investigate the effects of vialinin A on viability of human retinal endothelial cells(HRECs)under high glucose condition and its potential mechanism.METHODS:The HRECs were divided into four groups:normal glucose control group(NG,5 mmol/L D-glucose),high glucose group(HG,30 mmol/L D-glucose),HG+1μmol/L vialinin A group,and HG+5μmol/L vialinin A group.The cell viabilities were measured with cell counting kit-8(CCK-8)assay for proliferation,with scratch assay for migration,and tube formation,for evaluation of the impact of vialinin A on cellular behaviour.Real-time PCR and Western blotting were used to determine the expression level of vascular endothelial growth factor(VEGF).RESULTS:The proliferative capacity and migration of HRECs was reduced by 5μmol/L vialinin A in high glucose environment(both P<0.05).Vialinin A also inhibited highglucose-induced tube formation of HRECs.The expression level of VEGF and PI3K in HRECs was also significantly decreased by vialinin A(P<0.05).CONCLUSION:Vialinin A inhibits the cell viability of HRECs.It may serve as a potential target for anti-angiogenic therapy.

CircPMS1 promotes proliferation of pulmonary artery smooth muscle cells,pulmonary microvascular endothelial cells,and pericytes under hypoxia

Background:Circular RNAs(circRNAs)have been recognized as significant regulators of pulmonary hypertension(PH);however,the differential expression and function of circRNAs in different vascular cells under hypoxia remain unknown.Here,we identified co-differentially expressed circRNAs and determined their putative roles in the proliferation of pulmonary artery smooth muscle cells(PASMCs),pulmonary microvascular endothelial cells(PMECs),and pericytes(PCs)under hypoxia.Methods:Whole transcriptome sequencing was performed to analyze the differential expression of circRNAs in three different vascular cell types.Bioinformatic analysis was used to predict their putative biological function.Quantitative real-time polymerase chain reaction,Cell Counting Kit-8,and EdU Cell Proliferation assays were carried out to determine the role of circular postmeiotic segregation 1(circPMS1)as well as its potential sponge mechanism in PASMCs,PMECs,and PCs.Results:PASMCs,PMECs,and PCs exhibited 16,99,and 31 differentially expressed circRNAs under hypoxia,respectively.CircPMS1 was upregulated in PASMCs,PMECs,and PCs under hypoxia and enhanced the proliferation of vascular cells.CircPMS1may upregulate DEP domain containing 1(DEPDC1)and RNA polymerase II subunit D expression by targeting microRNA-432-5p(miR-432-5p)in PASMCs,upregulate MAX interactor 1(MXI1)expression by targeting miR-433-3p in PMECs,and upregulate zinc finger AN1-type containing 5(ZFAND5)expression by targeting miR-3613-5p in PCs.Conclusions:Our results suggest that circPMS1 promotes cell proliferation through the miR-432-5p/DEPDC1 or miR-432-5p/POL2D axis in PASMCs,through the miR-433-3p/MXI1 axis in PMECs,and through the miR-3613-5p/ZFAND5 axis in PCs,which provides putative targets for the early diagnosis and treatment of PH.

Non-enzymatic methods for isolation of stromal vascular fraction and adipose-derived stem cells:A systematic review

BACKGROUND Adipose-derived stem cells(ADSCs)and the stromal vascular fraction(SVF)have garnered substantial interest in regenerative medicine due to their potential to treat a wide range of conditions.Traditional enzymatic methods for isolating these cells face challenges such as high costs,lengthy processing time,and regulatory complexities.AIM This systematic review aimed to assess the efficacy and practicality of nonenzymatic,mechanical methods for isolating SVF and ADSCs,comparing these to conventional enzymatic approaches.METHODS Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines,a comprehensive literature search was conducted across multiple databases.Studies were selected based on inclusion criteria focused on non-enzymatic isolation methods for SVF and ADSCs from adipose tissue.The risk of bias was assessed,and a qualitative synthesis of findings was performed due to the methodological heterogeneity of the included studies.RESULTS Nineteen studies met the inclusion criteria,highlighting various mechanical techniques such as centrifugation,vortexing,and ultrasonic cavitation.The review identified significant variability in cell yield and viability,and the integrity of isolated cells across different non-enzymatic methods compared to enzymatic procedures.Despite some advantages of mechanical methods,including reduced processing time and avoidance of enzymatic reagents,the evidence suggests a need for optimization to match the cell quality and therapeutic efficacy achievable with enzymatic isolation.CONCLUSION Non-enzymatic,mechanical methods offer a promising alternative to enzymatic isolation of SVF and ADSCs,potentially simplifying the isolation process and reducing regulatory hurdles.However,further research is necessary to standardize these techniques and ensure consistent,high-quality cell yields for clinical applications.The development of efficient,safe,and reproducible non-enzymatic isolation methods could significantly advance the field of regenerative medicine.

Analyzing the pharmacological substances and targets of Xuefu Zhuyu decoction in hypertensive vascular endothelial cells

Background:Xuefu Zhuyu decoction(XFZY)could significantly improve the function of hypertensive vascular endothelial cells,but the targets and mechanism are not clear.This study is to analyze the pharmacological substances and targets of Xuefu Zhuyu decoction in hypertensive vascular endothelial cells.Methods:This study used Xuefu Zhuyu decoction to intervene human umbilical vein endothelial cells incubated by hypertensive patients’serum,then detected the function of vascular endothelial cells.The aqueous extract of XFZY was analyzed and validated by liquid chromatography-mass spectrometry technology;Finally,macromolecular docking technology was used to analyze the potential active substances and targets of XFZY in the prevention and treatment of hypertension.Results:Compared with the model group,the XFZY group showed a significant increase in NO expression(P<0.01)and a significant decrease in ET-1 expression(P<0.001);and the expression of BIP,P-JNK,CHOP,and BAX in XFZY group cells was significantly decreased(P<0.001),while the expression of JNK and BCL2 was significantly increased(P<0.001).19 main compounds were identified in XFZY and there were 3 pairs of molecular complexes with high affinity for markers of the endoplasmic reticulum stress,including BIP-Hesperidin complex,BIP-HSYA complex and JNK-Naringin complex.Conclusion:This study analyzed the potential pharmacodynamic substance and targets of Xuefu Zhuyu decoction in improving the function of hypertensive vascular endothelial cells,which could provide a scientific basis for the future molecular mechanism of XFZY in treating hypertension.

Ferroptosis inhibition protects vascular endothelial cells and maintains integrity of the blood-spinal cord barrier after spinal cord injury

Maintaining the integrity of the blood-spinal cord barrier is critical for the recove ry of spinal cord injury.Ferro ptosis contributes to the pathogenesis of spinal cord injury.We hypothesized that ferroptosis is involved in disruption of the blood-s pinal cord barrier.In this study,we administe red the ferroptosis inhibitor liproxstatin-1 intraperitoneally after contusive spinal co rd injury in rats.Liproxstatin-1 improved locomotor recovery and somatosensory evoked potential electrophysiological performance after spinal cord inju ry.Liproxstatin-1 maintained blood-spinal cord barrier integrity by upregulation of the expression of tight junction protein.Liproxstatin-1 inhibited ferroptosis of endothelial cell after spinal cord injury,as shown by the immunofluorescence of an endothelial cell marker(rat endothelium cell antigen-1,RECA-1) and fe rroptosis markers Acyl-CoA synthetase long-chain family member 4 and 15-lipoxygenase.Liproxstatin-1reduced brain endothelial cell ferroptosis in vitro by upregulating glutathione peroxidase 4 and downregulating Acyl-CoA synthetase long-chain family member4 and 15-lipoxygenase.Furthermore,inflammatory cell recruitment and astrogliosis were mitigated after liproxstatin-1 treatment.In summary,liproxstatin-1im proved spinal cord injury recovery by inhibiting ferroptosis in endothelial cells and maintaining blood-s pinal co rd barrier integrity.

MicroRNA-146a Promotes Embryonic Stem Cell Differentiation towards Vascular Smooth Muscle Cells through Regulation of Kruppel-like Factor 4

Objective Vascular smooth muscle cell(VSMC)differentiation from stem cells is one source of the increasing number of VSMCs that are involved in vascular remodeling-related diseases such as hypertension,atherosclerosis,and restenosis.MicroRNA-146a(miR-146a)has been proven to be involved in cell proliferation,migration,and tumor metabolism.However,little is known about the functional role of miR-146a in VSMC differentiation from embryonic stem cells(ESCs).This study aimed to determine the role of miR-146a in VSMC differentiation from ESCs.Methods Mouse ESCs were differentiated into VSMCs,and the cell extracts were analyzed by Western blotting and RT-qPCR.In addition,luciferase reporter assays using ESCs transfected with miR-146a/mimic and plasmids were performed.Finally,C57BL/6J female mice were injected with mimic or miR-146a-overexpressing ESCs,and immunohistochemistry,Western blotting,and RT-qPCR assays were carried out on tissue samples from these mice.Results miR-146a was significantly upregulated during VSMC differentiation,accompanied with the VSMC-specific marker genes smooth muscle-alpha-actin(SMαA),smooth muscle 22(SM22),smooth muscle myosin heavy chain(SMMHC),and h1-calponin.Furthermore,overexpression of miR-146a enhanced the differentiation process in vitro and in vivo.Concurrently,the expression of Kruppel-like factor 4(KLF4),predicted as one of the top targets of miR-146a,was sharply decreased in miR-146a-overexpressing ESCs.Importantly,inhibiting KLF4 expression enhanced the VSMC-specific gene expression induced by miR-146a overexpression in differentiating ESCs.In addition,miR-146a upregulated the mRNA expression levels and transcriptional activity of VSMC differentiation-related transcription factors,including serum response factor(SRF)and myocyte enhancer factor 2c(MEF-2c).Conclusion Our data support that miR-146a promotes ESC-VSMC differentiation through regulating KLF4 and modulating the transcription factor activity of VSMCs.

Potential plausible role of Wharton’s jelly mesenchymal stem cells for diabetic bone regeneration

This letter addresses the review titled“Wharton’s jelly mesenchymal stem cells:Future regenerative medicine for clinical applications in mitigation of radiation injury”.The review highlights the regenerative potential of Wharton’s jelly mesenchymal stem cells(WJ-MSCs)and describes why WJ-MSCs will become one of the most probable stem cells for future regenerative medicine.The potential plausible role of WJ-MSCs for diabetic bone regeneration should be noticeable,which will provide a new strategy for improving bone regeneration under diabetic conditions.

Human umbilical cord mesenchymal stem cells derivedexosomes on VEGF-A in hypoxic-induced mice retinal astrocytes and mice model of retinopathy of prematurity

AIM:To observe the effect of human umbilical cord mesenchymal stem cells(hUCMSCs)secretions on the relevant factors in mouse retinal astrocytes,and to investigate the effect of hUCMSCs on the expression of vascular endothelial growth factor-A(VEGF-A)and to observe the therapeutic effect on the mouse model of retinopathy of prematurity(ROP).METHODS:Cultured hUCMSCs and extracted exosomes from them and then retinal astrocytes were divided into control group and hypoxia group.MTT assay,flow cytometry,reverse transcription-polymerase chain reaction(RT-PCR)and Western blot were used to detect related indicators.Possible mechanisms by which hUCMSCs exosomes affect VEGF-A expression in hypoxia-induced mouse retinal astrocytes were explored.At last,the efficacy of exosomes of UCMSCs in a mouse ROP model was explored.Graphpad6 was used to comprehensively process data information.RESULTS:The secretion was successfully extracted from the culture supernatant of hUCMSCs by gradient ultracentrifugation.Reactive oxygen species(ROS)and hypoxia inducible factor-1α(HIF-1α)of mice retinal astrocytes under different hypoxia time and the expression level of VEGF-A protein and VEGF-A mRNA increased,and the ROP cell model was established after 6h of hypoxia.The secretions of medium and high concentrations of hUCMSCs can reduce ROS and HIF-1α,the expression levels of VEGF-A protein and VEGF-A mRNA are statistically significant and concentration dependent.Compared with the ROP cell model group,the expression of phosphatidylinositol 3-kinase(PI3K)/protein kinase B(AKT)/mammalian target of rapamycin(mTOR)signal pathway related factors in the hUCMSCs exocrine group is significantly decreased.The intravitreal injection of the secretions of medium and high concentrations of hUCMSCs can reduce VEGF-A and HIF-1αin ROP model tissues.HE staining shows that the number of retinal neovascularization in ROP mice decreases with the increase of the dose of hUCMSCs secretion.CONCLUSION:In a hypoxia induced mouse retinal astrocyte model,hUCMSCs exosomes are found to effectively reduce the expression of HIF-1αand VEGF-A,which are positively correlated with the concentration of hUCMSCs exosomes.HUCMSCs exosomes can effectively reduce the number of retinal neovascularization and the expression of HIF-1αand VEGF-A proteins in ROP mice,and are positively correlated with drug dosage.Besides,they can reduce the related factors on the PI3K/AKT/mTOR signaling pathway.

Adipose-derived stem cells and knee osteoarthritis:New perspectives,old concerns

In this editorial,we comment on the paper by Muthu et al published in the recent issue of the journal.This editorial review focusses on the use of adipose-derived stem cells(ADSCs)in knee osteoarthritis treatment.We discuss the differences between the stromal vascular fraction and microfragmented adipose tissue and highlight the results of clinical studies comparing both treatments and the use of hyaluronic acid,platelet-rich plasma,and bone marrow aspirate concentrate.The use of expanded ADSCs is also discussed;moreover,concerns regarding treatment with ADSCs,particularly the heterogeneity of published studies and the need to standardize protocols to explore clinical potential is explored.

Anti-vascular endothelial growth factor drugs combined with laser photocoagulation maintain retinal ganglion cell integrity in patients with diabetic macular edema: study protocol for a prospective, non-randomized, controlled clinical trial

The integrity of retinal ganglion cells is tightly associated with diabetic macular degeneration that leads to damage and death of retinal ganglion cells,affecting vision.The major clinical treatments for diabetic macular edema are anti-vascular endothelial growth factor drugs and laser photocoagulation.However,although the macular thickness can be normalized with each of these two therapies used alone,the vision does not improve in many patients.This might result from the incomplete recovery of retinal ganglion cell injury.Therefore,a prospective,non-randomized,controlled clinical trial was designed to investigate the effect of anti-vascular endothelial growth factor drugs combined with laser photocoagulation on the integrity of retinal ganglion cells in patients with diabetic macular edema and its relationship with vision recovery.In this trial,150 patients with diabetic macular edema will be equally divided into three groups according to therapeutic methods,followed by treatment with anti-vascular endothelial growth factor drugs,laser photocoagulation therapy,and their combination.All patients will be followed up for 12 months.The primary outcome measure is retinal ganglion cell-inner plexiform layer thickness at 12 months after treatment.The secondary outcome measures include retinal ganglion cell-inner plexiform layer thickness before and 1,3,6,and 9 months after treatment,retinal nerve fiber layer thickness,best-corrected visual acuity,macular area thickness,and choroidal thickness before and 1,3,6,9,and 12 months after treatment.Safety measure is the incidence of adverse events at 1,3,6,9,and 12 months after treatment.The study protocol hopes to validate the better efficacy and safety of the combined treatment in patients with diabetic macula compared with the other two monotherapies alone during the 12-month follow-up period.The trial is designed to focus on clarifying the time-effect relationship between imaging measures related to the integrity of retinal ganglion cells and best-corrected visual acuity.The trial protocol was approved by the Medical Ethics Committee of the Affiliated Hospital of Beihua University with approval No.(2023)(26)on April 25,2023,and was registered with the Chinese Clinical Trial Registry(registration number:ChiCTR2300072478,June 14,2023,protocol version:2.0).

Inhibition of VEGF-A expression in hypoxia-exposed fetal retinal microvascular endothelial cells by exosomes derived from human umbilical cord mesenchymal stem cells

Objective:This study aimed to investigate the potential of human umbilical cord mesenchymal stem cell(hucMSC)-derived exosomes(hucMSC-Exos)in inhibiting hypoxia-induced cell hyper proliferation and overexpression of vascular endothelial growth factor A(VEGF-A)in immature human fetal retinal microvascular endothelial cells(hfRMECs).Methods:Exosomes were isolated from hucMSCs using cryogenic ultracentrifugation and characterized through various techniques,including transmission electron microscopy,nanoparticle tracking analysis,bicinchoninic acid assays,and western blotting.The hfRMECs were identified using von Willebrand factor(vWF)co-staining and divided into four groups:a control group cultured under normoxic condition,a hypoxic model group,a hypoxic group treated with low-concentration hucMSC-Exos(75μg/mL)and a hypoxic group treated with high-concentration hucMSC-Exos(100μg/mL).Cell viability and proliferation were assessed using Cell Counting Kit-8(CCK-8)assay and EdU(5-ethynyl-2′-deoxyuridine)assay respectively.Expression levels of VEGF-A were evaluated using RT-PCR,western blotting and immunofluorescence.Results:Hypoxia significantly increased hfRMECs’viability and proliferation by upregulating VEGF-A levels.The administration of hucMSC-Exos effectively reversed this response,with the high-concentration group exhibiting greater efficacy compared to the lowconcentration group.Conclusion:In conclusion,hucMSC-Exos can dose-dependently inhibit hypoxia-induced hyperproliferation and VEGF-A overexpression in immature fetal retinal microvascular endothelial cells.

Integrin binding peptides facilitate growth and interconnected vascular-like network formation of rat primary cortical vascular endothelial cells in vitro

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.

Down-regulation of histone deacetylase 7 reduces biological activities of retinal microvascular endothelial cells under high glucose condition and related mechanism

AIM:To investigate the expression and effect of histone deacetylase 7(HDAC7)in human retinal microvascular endothelial cells(HRMECs)under high glucose condition and related mechanism,and the expression of HDAC7 in the retinal tissue in diabetic rats.METHODS:The expression of HDAC7 in HRMECs under high glucose and the retinal tissue from normal or diabetic rats were detected with immunohistochemistry and Western blot.LV-shHDAC7 HRMECs were used to study the effect of HDAC7 on cell activities.Cell count kit-8(CCK-8),5-ethynyl2’-deoxyuridine(EdU),flow cytometry,scratch test,Transwell test and tube formation assay were used to examine the ability of cell proliferation,migration,and angiogenesis.Finally,a preliminary exploration of its mechanism was performed by Western blot.RESULTS:The expression of HDAC7 was both upregulated in retinal tissues of diabetic rats and high glucosetreated HRMECs.Down-regulation of HDAC7 expression significantly reduced the ability of proliferation,migration,and tube formation,and reversed the high glucose-induced high expression of CDK1/Cyclin B1 and vascular endothelial growth factor in high glucose-treated HRMECs.CONCLUSION:High glucose can up-regulate the expression of HDAC7 in HRMECs.Down-regulation of HDAC7 can inhibit HRMECs activities.HDAC7 is proposed to be involved in pathogenesis of diabetic retinopathy and a therapeutic target.

Arsenic trioxide inhibites transgenic tumor necrosis factor-α promoter activity in vascular smooth muscle cells and THP-1 monocytes in vitro

Aim This study was to evaluate the effect of arsenic trioxide （As2O3） on the transgenic TNF-α promoter activity in cultured vascular smooth muscle cells （VSMCs） and THP-1 monocytes. Methods Human TNF-α promoter was constructed by reporter gene system and was transiently transfected into VSMCs and THP-1 in vitro. The promoter activity was tested by luciferase activity with or without LPS and Ang Ⅱ stimulation, before and after different dosage of As2O3 treatment. Results 1. TNF-α promoter effectively expressed in VSMCs and THP-1 compared with CMV promoter （58.3% and 80.9%, respectively）. Both LPS and Ang Ⅱ significantly up-regulated TNF-α promoter activity （P〈0.05）. 2. As2O3 significantly inhibited, both intact and LPS/Ang Ⅱ stimulated promoter activity, in a dose dependent manner （P〈0.05）, and in both cell type. Conclusion These results manifested that, the inhibition effect of As2O3 on the activity of human TNF-α promoter indicated its potential inhibition on pro-inflammatory cytokine genes expression at transcriptional level and its potential anti-inflammatory property in the cardiovascular system.

Urocortin, the neuropeptide, inhibits the viability of ECV304 cells and rat vascular smooth muscle cells

Objective: This study aims to investigate the effects of urocortin (Ucn) on the viability of endothelial cells (ECV304) and rat vascular muscle cells (VSMC). Methods: Rat aortic VSMC were isolated from the rats' thoracic aorta. We studied the effect of Ucn on the viability of ECV304 cells and VSMC by using a tetrazolium (MTT) assay.Results: Ucn (10 -7 mol/L) inhibited the viability of ECV304 cells and VSMC. Inhibition rates are 13% and 15%, respectively(P<0.05, compared with Control). This inhibition was not dependent on the affecting time and was not affected by the addition of ATP-sensitive potassium channel (KATP channel) blocker, glybenclamide (Gly, 10 mol/L). Conclusion: Ucn inhibits the viability of ECV304 and VSMC. Our results suggest that Ucn may be a new vasoactive agent and may have a beneficial effect in the process of vascular remodeling (VR).

Overexpression of vascular endothelial growth factor enhances the neuroprotective effects of bone marrow mesenchymal stem cell transplantation in ischemic stroke

Although bone marrow mesenchymal stem cells(BMSCs)might have therapeutic potency in ischemic stroke,the benefits are limited.The current study investigated the effects of BMSCs engineered to overexpress vascular endothelial growth factor(VEGF)on behavioral defects in a rat model of transient cerebral ischemia,which was induced by middle cerebral artery occlusion.VEGF-BMSCs or control grafts were injected into the left striatum of the infarcted hemisphere 24 hours after stroke.We found that compared with the stroke-only group and the vehicle-and BMSCs-control groups,the VEGF-BMSCs treated animals displayed the largest benefits,as evidenced by attenuated behavioral defects and smaller infarct volume 7 days after stroke.Additionally,VEGF-BMSCs greatly inhibited destruction of the blood-brain barrier,increased the regeneration of blood vessels in the region of ischemic penumbra,and reducedneuronal degeneration surrounding the infarct core.Further mechanistic studies showed that among all transplant groups,VEGF-BMSCs transplantation induced the highest level of brain-derived neurotrophic factor.These results suggest that BMSCs transplantation with vascular endothelial growth factor has the potential to treat ischemic stroke with better results than are currently available.

β-Estradiol 17-acetate enhances the in vitro vitality of endothelial cells isolated from the brain of patients subjected to neurosurgery

In the current landscape of endothelial cell isolation for building in vitro models of the blood-brain barrier,our work moves towards reproducing the features of the neurovascular unit to achieve glial compliance through an innovative biomimetic coating technology for brain chronic implants.We hypothesized that the autologous origin of human brain mic rovascular endothelial cells(hBMECs)is the first requirement for the suitable coating to prevent the glial inflammato ry response trigge red by foreign neuroprosthetics.Therefo re,this study established a new procedure to preserve the in vitro viability of hBMECs isolated from gray and white matter specimens taken from neurosurge ry patients.Culturing adult hBMECs is generally considered a challenging task due to the difficult survival ex vivo and progressive reduction in proliferation of these cells.The addition of 10 nMβ-estradiol 17-acetate to the hBMEC culture medium was found to be an essential and discriminating factor promoting adhesion and proliferation both after isolation and thawing,suppo rting the well-known protective role played by estrogens on microvessels.In particular,β-estradiol 17-acetate was critical for both freshly isolated and thawed female-derived hBMECs,while it was not necessary for freshly isolated male-derived hBMECs;however,it did countera ct the decay in the viability of the latter after thawing.The tumo r-free hBMECs were thus cultured for up to 2 months and their growth efficiency was assessed befo re and after two periods of cryopreservation.Des pite the thermal stress,the hBMECs remained viable and suitable for re-freezing and storage for several months.This approach increasing in vitro viability of hBMECs opens new perspectives for the use of cryopreserved autologous hBMECs as biomimetic therapeutic tools,offering the potential to avoid additional surgical sampling for each patient.

Vascular dysfunction in diabetes: The endothelial progenitor cells as new therapeutic strategy

The vascular endothelium is a critical determinant of dia- betes-associated vascular complications, and improving endothelial function is an important target for therapy. Diabetes mellitus contributes to endothelial cell injury and dysfunction. Endothelial progenitor cells (EPCs) play a critical role in maintaining endothelial function and might affect the progression of vascular disease. EPCs are essential to blood vessel formation, can differentiate into mature endothelial cells, and promote the repair of damaged endothelium. In diabetes, the circulating EPC count is low and their functionality is impaired. The me- chanisms that underlie this reduced count and impaired functionality are poorly understood. Knowledge of the status of EPCs is critical for assessing the health of the vascular system, and interventions that increase the number of EPCs and restore their angiogenic activity in diabetes may prove to be particularly beneficial. The pre-sent review outlines current thinking on EPCs' therapeutic potential in endothelial dysfunction in diabetes, as well as evidence-based perspectives regarding their use for vascular regenerative medicine.

Early expressions of hypoxia-inducible factor 1alpha and vascular endothelial growth factor increase the neuronal plasticity of activated endogenous neural stem cells after focal cerebral ischemia

Endogenous neural stem cells become ＂activated＂ after neuronal injury, but the activation sequence and fate of endogenous neural stem cells in focal cerebral ischemia model are little known. We evaluated the relationships between neural stem cells and hypoxia-inducible factor-1α and vascular endothelial growth factor expression in a photothromobotic rat stroke model using immunohistochemistry and western blot analysis. We also evaluated the chronological changes of neural stem cells by 5-bromo-2′-deoxyuridine（BrdU） incorporation. Hypoxia-inducible factor-1α expression was initially increased from 1 hour after ischemic injury, followed by vascular endothelial growth factor expression. Hypoxia-inducible factor-1α immunoreactivity was detected in the ipsilateral cortical neurons of the infarct core and peri-infarct area. Vascular endothelial growth factor immunoreactivity was detected in bilateral cortex, but ipsilateral cortex staining intensity and numbers were greater than the contralateral cortex. Vascular endothelial growth factor immunoreactive cells were easily found along the peri-infarct area 12 hours after focal cerebral ischemia. The expression of nestin increased throughout the microvasculature in the ischemic core and the peri-infarct area in all experimental rats after 24 hours of ischemic injury. Nestin immunoreactivity increased in the subventricular zone during 12 hours to 3 days, and prominently increased in the ipsilateral cortex between 3–7 days. Nestin-labeled cells showed dual differentiation with microvessels near the infarct core and reactive astrocytes in the peri-infarct area. BrdU-labeled cells were increased gradually from day 1 in the ipsilateral subventricular zone and cortex, and numerous BrdU-labeled cells were observed in the peri-infarct area and non-lesioned cortex at 3 days. BrdU-labeled cells rather than neurons, were mainly co-labeled with nestin and GFAP. Early expressions of hypoxia-inducible factor-1α and vascular endothelial growth factor after ischemia made up the microenvironment to increase the neuronal plasticity of activated endogenous neural stem cells. Moreover, neural precursor cells after large-scale cortical injury could be recruited from the cortex nearby infarct core and subventricular zone.