Endothelial Progenitor Cells Migration Research Articles

Dihydrotestosterone Augments the Angiogenic and Migratory Potential of Human Endothelial Progenitor Cells by an Androgen Receptor-Dependent Mechanism.

Endothelial progenitor cells (EPCs) play a critical role in cardiovascular regeneration. Enhancement of their native properties would be highly beneficial to ensuring the proper functioning of the cardiovascular system. As androgens have a positive effect on the cardiovascular system, we hypothesized that dihydrotestosterone (DHT) could also influence EPC-mediated repair processes. To evaluate this hypothesis, we investigated the effects of DHT on cultured human EPCs' proliferation, viability, morphology, migration, angiogenesis, gene and protein expression, and ability to integrate into cardiac tissue. The results showed that DHT at different concentrations had no cytotoxic effect on EPCs, significantly enhanced the cell proliferation and viability and induces fast, androgen-receptor-dependent formation of capillary-like structures. DHT treatment of EPCs regulated gene expression of androgen receptors and the genes and proteins involved in cell migration and angiogenesis. Importantly, DHT stimulation promoted EPC migration and the cells' ability to adhere and integrate into murine cardiac slices, suggesting it has a role in promoting tissue regeneration. Mass spectrometry analysis further highlighted the impact of DHT on EPCs' functioning. In conclusion, DHT increases the proliferation, migration, and androgen-receptor-dependent angiogenesis of EPCs; enhances the cells' secretion of key factors involved in angiogenesis; and significantly potentiates cellular integration into heart tissue. The data offer support for potential therapeutic applications of DHT in cardiovascular regeneration and repair processes.

Transdermal Nicotine Patch Increases the Number and Function of Endothelial Progenitor Cells in Young Healthy Nonsmokers without Adverse Hemodynamic Effects.

Transdermal nicotine patches (TNPs), administering nicotine into the bloodstream through skin, have been widely used as nicotine replacement therapy, and exposure to nicotine can be detected by measurement of plasma cotinine concentration. In animal studies, nicotine treatment could increase the number of endothelial progenitor cells (EPCs), but the effect of TNPs on circulating EPCs and their activity in humans remained unclear. This study aimed to explore the influence of TNPs on circulating EPCs with surface markers of CD34, CD133, and/or KDR, and colony-forming function plus migration activity of early EPCs derived from cultured peripheral blood mononuclear cells before and after TNP treatments in young healthy nonsmokers. In parallel, pulse wave analysis (PWA) was applied to evaluate the vascular effect of TNP treatments. Twenty-one participants (25.8 ± 3.6 years old, 10 males) used TNP (nicotine: 4.2 mg/day) for 7 consecutive days. During the treatment, the CD34+ EPCs progressively increased in number. In addition, the number of EPCs positive for CD34/KDR, CD133, and CD34/CD133 were also increased on day 7 of the treatment. Furthermore, the early EPC colony-forming function and migration activity were increased with the plasma cotinine level positively correlating with change in colony-forming unit number. PWA analyses on day 7, compared with pretreatment, did not show significant change except diastolic pressure time index, which was prolonged and implied potential vascular benefit. In conclusion, 7-day TNP treatments could be a practical strategy to enhance angiogenesis of circulating EPCs to alleviate tissue ischemia without any hemodynamic concern.

MiR-155 promotes compensatory lung growth by inhibiting JARID2 activation of CD34+ endothelial progenitor cells.

Bone marrow-derived CD34-positive (CD34+) endothelial progenitor cells (EPCs) has unique functions in the mechanism of compensatory lung growth (CLG). The content of this study is mainly to describe the effect of microRNA (miR)-155 in the mechanisms of EPCs and CLG. Our study found that transfection of miR-155 mimic could promote EPC proliferation, migration and tube formation, while transfection of miR-155 inhibitor had the opposite effect. It was also found that transfection of pc-JARID2 inhibited EPC proliferation, migration and tube formation, while transfection of si-JARID2 had the opposite effect. miR-155 can target and negatively regulate JARID2 expression. Overexpression of JARID2 weakened the promoting effects of miR-155 mimic on EPC proliferation, migration, and tubular formation, while silencing JARID2 weakened the inhibitory effects of miR-155 inhibitors on EPC proliferation, migration, and tubular formation. Transplantation of EPCs transfected with miR-155 mimic into the left lung model effectively increased lung volume, total alveolar number, diaphragm surface area, and lung endothelial cell number, while transplantation of EPCs co-transfected with miR-155 mimic and pc-JARID2 reversed this phenomenon. Overall, we found that miR-155 activates CD34+ EPC by targeting negative regulation of JARID2 and promotes CLG.

C1q/Tumor Necrosis Factor-Related Protein-9 Is a Novel Vasculoprotective Cytokine That Restores High Glucose-Suppressed Endothelial Progenitor Cell Functions by Activating the Endothelial Nitric Oxide Synthase.

This study investigated whether gCTRP9 (globular C1q/tumor necrosis factor-related protein-9) could restore high-glucose (HG)-suppressed endothelial progenitor cell (EPC) functions by activating the endothelial nitric oxide synthase (eNOS). EPCs were treated with HG (25 mmol/L) and gCTRP9. Migration, adhesion, and tube formation assays were performed. Adiponectin receptor 1, adiponectin receptor 2, and N-cadherin expression and AMP-activated protein kinase, protein kinase B, and eNOS phosphorylation were measured by Western blotting. eNOS activity was determined using nitrite production measurement. Invivo reendothelialization and EPC homing assays were performed using Evans blue and immunofluorescence in mice. Treatment with gCTRP9 at physiological levels enhanced migration, adhesion, and tube formation of EPCs. gCTRP9 upregulated the phosphorylation of AMP-activated protein kinase, protein kinase B, and eNOS and increased nitrite production in a concentration-dependent manner. Exposure of EPCs to HG-attenuated EPC functions induced cellular senescence and decreased eNOS activity and nitric oxide synthesis; the effects of HG were reversed by gCTRP9. Protein kinase B knockdown inhibited eNOS phosphorylation but did not affect gCTRP9-induced AMP-activated protein kinase phosphorylation. HG impaired N-cadherin expression, but treatment with gCTRP9 restored N-cadherin expression after HG stimulation. gCTRP9 restored HG-impaired EPC functions through both adiponectin receptor 1 and N-cadherin-mediated AMP-activated protein kinase /protein kinase B/eNOS signaling. Nude mice that received EPCs treated with gCTRP9 under HG medium showed a significant enhancement of the reendothelialization capacity compared with those with EPCs incubated under HG conditions. CTRP9 promotes EPC migration, adhesion, and tube formation and restores these functions under HG conditions through eNOS-mediated signaling mechanisms. Therefore, CTRP9 modulation could eventually be used for vascular healing after injury.

Effect of sunitinib against Echinococcus multilocularis through inhibition of VEGFA-induced angiogenesis

BackgroundAlveolar echinococcosis (AE) is a lethal zoonosis caused by the fox tapeworm Echinococcus multilocularis. The disease is difficult to treat, and an effective therapeutic drug is urgently needed. Echinococcus multilocularis-associated angiogenesis is required by the parasite for growth and metastasis; however, whether antiangiogenic therapy is effective for treating AE is unclear.MethodsThe in vivo efficacy of sunitinib malate (SU11248) was evaluated in mice by secondary infection with E. multilocularis. Enzyme-linked immunosorbent assays (ELISAs) were used to evaluate treatment effects on serum IL-4 and vascular endothelial growth factor A (VEGFA) levels after SU11248 treatment. Gross morphological observations and immunohistochemical staining were used to evaluate the impact of SU11248 on angiogenesis and the expression of pro-angiogenic factors VEGFA and VEGF receptor 2 (VEGFR2) in the metacestode tissues. Furthermore, the anthelmintic effects of SU11248 were tested on E. multilocularis metacestodes in vitro. The effect of SU11248 on the expression of VEGFA, VEGFR2, and phosphorylated VEGFR2 (p-VEGFR2) in liver cells infected with protoscoleces in vitro was detected by western blotting, reverse transcription quantitative polymerase chain reaction (RT-qPCR), and enzyme-linked immunosorbent assay (ELISA). The influence of SU11248 on endothelial progenitor cell (EPC) proliferation and migration was determined using CCK8 and transwell assays.ResultsIn vivo, SU11248 treatment markedly reduced neovascular lesion formation and substantially inhibited E. multilocularis metacestode growth in mice. Further, it exhibited high anti-hydatid activity as efficiently as albendazole (ABZ), and the treatment resulted in reduced protoscolex development. In addition, VEGFA, VEGFR2, and p-VEGFR2 expression was significantly decreased in the metacestode tissues after SU11248 treatment. However, no effect of SU11248 on serum IL-4 levels was observed. In vitro, SU11248 exhibited some anthelmintic effects and damaged the cellular structure in the germinal layer of metacestodes at concentrations below those generally considered acceptable for treatment (0.12–0.5 μM). Western blotting, RT-qPCR, and ELISA showed that in co-cultured systems, only p-VEGFR2 levels tended to decrease with increasing SU11248 concentrations. Furthermore, SU11248 was less toxic to Reuber rat hepatoma (RH) cells and metacestodes than to EPCs, and 0.1 μM SU11248 completely inhibited EPC migration to the supernatants of liver cell and protoscolex co-cultures.ConclusionsSU11248 is a potential candidate drug for the treatment of AE, which predominantly inhibits parasite-induced angiogenesis. Host-targeted anti-angiogenesis treatment strategies constitute a new avenue for the treatment of AE.Graphical

CCN1 inhibition affects the function of endothelial progenitor cells under high-glucose condition.

The impact of cysteine-rich angiogenic inducer 61 (Cyr61, also called CCN1) on endothelial progenitor cells (EPCs) from diabetic-rat-derived whole peripheral and bone marrow remains poorly understood. Therefore, the expression levels of CCN1, CCN1-induced C-X-C chemokine receptor type 4 (CXCR4), and stromal-cell-derived factor-1 (SDF-1) were explored under high glucose (HG) conditions. The aim of the study was to explore the effects of high CCN1 levels on EPC activity in diabetic rats through mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) pathway modulation. Primary EPCs were isolated from bone marrow and whole peripheral blood of streptozocin (STZ)-induced diabetic Sprague-Dawley rats and controls. Cell migration, tube formation ability and viability were determined using transwell, Cell Counting Kit-8 (CCK-8), and Matrigel®-based capillary-like tube formation assays. Protein and gene expression levels were measured by western blot and real-time quantitative polymerase chain reaction (RT-qPCR). The study findings showed that EPC migration, viability and tube formation ability were significantly lower under HG conditions. High CCN1 expression levels restored EPC function by inducing SDF-1 and CXCR4 in EPCs under HG conditions. Furthermore, HG suppressed MEK/ERK phosphorylation, while an ERK1/2 agonist rescued EPC CCN1-SDF-1/CXCR4 expression under HG conditions through the activation of the MEK/ERK pathway. This study demonstrates that high CCN1 expression levels restored EPC functions, partly by modulating MEK/ERK signaling. These findings provide a basis for developing novel therapeutic methods for diabetic vascular neogenesis and vascular injury repair.

Sonic hedgehog signaling promotes angiogenesis of endothelial progenitor cells to improve pressure ulcers healing by PI3K/AKT/eNOS signaling.

Pressure ulcer is a severe disease in the paralyzed and aging populations. Endothelial progenitor cells (EPCs) are able to regulate ulcer healing by modulating angiogenesis, but the molecular mechanism is still obscure. Sonic hedgehog (SHH) signaling contributes to angiogenesis in various diseases and has been identified to modulate EPCs function. Here, we aimed to explore the significance of SHH signaling in EPCs function during pressure ulcers. The EPCs were isolated and characterized by the expression of DiI-acLDL and bind fluorescein iso-thiocyanate UEA-1. Cell proliferation was detected by cell counting kit 8 (CCK-8). The DiI-acLDL and bind fluorescein iso-thiocyanate UEA-1 were analyzed by immunofluorescent analysis. The angiogenesis of EPCs was analyzed by tube formation assay. The pressure ulcers rat model was constructed, the wound injury was analyzed by H&E staining and angiogenesis was analyzed by the accumulation of CD31 based on immunofluorescent analysis. The expression of patched-1 and Gli-1 was enhanced by SHH activator SAG but reduced by SHH inhibitor cyclopamine in the EPCsThe PI3K, Akt, eNOS expression and the Akt phosphorylation were induced by SAG, while the treatment of cyclopamine presented a reversed result. The proliferation and migration of EPCs were enhanced by SAG but repressed by cyclopamine or PI3K/AKT/eNOS signaling inhibitor Y294002, in which the co-treatment of Y294002 could reverse the effect of SAG. Thus, we found that SHH signaling activated angiogenesis properties of EPCs to improve pressure ulcers healing by PI3K/AKT/eNOS signaling. SHH signaling may serve as the potential target for attenuating pressure ulcers.

Bioprinted constructs that simulate nerve-bone crosstalk to improve microenvironment for bone repair.

Crosstalk between nerves and bone is essential for bone repair, for which Schwann cells (SCs) are crucial in the regulation of the microenvironment. Considering that exosomes are critical paracrine mediators for intercellular communication that exert important effects in tissue repair, the aim of this study is to confirm the function and molecular mechanisms of Schwann cell-derived exosomes (SC-exos) on bone regeneration and to propose engineered constructs that simulate SC-mediated nerve-bone crosstalk. SCs promoted the proliferation and differentiation of bone marrow mesenchymal stem cells (BMSCs) through exosomes. Subsequent molecular mechanism studies demonstrated that SC-exos promoted BMSC osteogenesis by regulating the TGF-β signaling pathway via let-7c-5p. Interestingly, SC-exos promoted the migration and tube formation performance of endothelial progenitor cells. Furthermore, the SC-exos@G/S constructs were developed by bioprinting technology that simulated SC-mediated nerve-bone crosstalk and improved the bone regeneration microenvironment by releasing SC-exos, exerting the regulatory effect of SCs in the microenvironment to promote innervation, vascularization, and osteogenesis and thus effectively improving bone repair in a cranial defect model. This study demonstrates the important role and underlying mechanism of SCs in regulating bone regeneration through SC-exos and provides a new engineered strategy for bone repair.

Transplantation of endothelial progenitor cells improves myocardial hypertrophy in spontaneously hypertensive rats through HO-1/CREB3/AKT axis

Hypertensive myocardial hypertrophy produces a hostile microenvironment characterized by cardiomyocyte hypertrophy, inflammation and oxidative stress, which also leads to endothelial progenitor cells (EPCs) dysfunction, preventing EPC migration, adhesion and angiogenesis. Heme oxygenase-1 (HO-1) is an intracellular protein that plays an important role in angiogenesis and cell survival. The upregulation of cAMP response element-binding protein 3 (CREB3) is closely related to the formation of endothelial cells. The purpose of this study was to evaluate the role of HO-1 and CREB3 in EPCs and their effects on hypertensive myocardial hypertrophy. EPCs were transfected with HO-1 adenoviral overexpression vector (Ad–HO–1) or together with CREB3 siRNA (si-CREB3), or transfected with CREB3 adenoviral overexpression vector (Ad-CREB3) or together with HO-1 siRNA, and then treated with 100 nM Ang Ⅱ for 12 h. Overexpressing HO-1 or CREB3 promoted adhesion to extracellular matrix, cell migration, and angiogenesis, inhibited the secretion of inflammatory factors TNF-α and IL-6, and reduced ROS level, ICAM-1 and MCP-1 mRNA expression levels in EPCs treated with Ang Ⅱ. Online prediction and Co-IP assay showed that HO-1 interacts with CREB3, and they promote expression of each other. EPC-conditioned medium supplemented with CREB3 recombinant protein decreased the levels of ANP and BNP mRNA in H9C2 cells treated with Ang Ⅱ and alleviated oxidative stress. Ad-CREB3 transfected EPCs promoted the phosphorylation of AKT in vivo and in vitro, thereby improving myocardial swelling and dysfunction in SHR rats. Taken together, transplantation of CREB3 overexpressing EPCs alleviates myocardial hypertrophy in spontaneously hypertensive rats by promoting HO-1 protein expression and AKT phosphorylation.

StemRegenin-1 Attenuates Endothelial Progenitor Cell Senescence by Regulating the AhR Pathway-Mediated CYP1A1 and ROS Generation.

Endothelial progenitor cell (EPC)-based stem cell therapy is a promising therapeutic strategy for vascular diseases. However, continuous in vitro expansion for clinical studies induces the loss of EPC functionality due to aging. In this study, we investigated the effects of StemRegenin-1 (SR-1), an antagonist of aryl hydrocarbon receptor (AhR), on replicative senescence in EPCs. We found that SR-1 maintained the expression of EPC surface markers, including stem cell markers, such as CD34, c-Kit, and CXCR4. Moreover, SR-1 long-term-treated EPCs preserved their characteristics. Subsequently, we demonstrated that SR-1 showed that aging phenotypes were reduced through senescence-associated phenotypes, such as β-galactosidase activity, SMP30, p21, p53, and senescence-associated secretory phenotype (SASP). SR-1 treatment also increased the proliferation, migration, and tube-forming capacity of senescent EPCs. SR-1 inhibited the AhR-mediated cytochrome P450 (CYP)1A1 expression, reactive-oxygen species (ROS) production, and DNA damage under oxidative stress conditions in EPCs. Furthermore, as a result of CYP1A1-induced ROS inhibition, it was found that accumulated intracellular ROS were decreased in senescent EPCs. Finally, an in vivo Matrigel plug assay demonstrated drastically enhanced blood vessel formation via SR-1-treated EPCs. In summary, our results suggest that SR-1 contributes to the protection of EPCs against cellular senescence.

Carvacrol Improves Vascular Function in Hypertensive Animals by Modulating Endothelial Progenitor Cells.

Carvacrol, a phenolic monoterpene, has diverse biological activities, highlighting its antioxidant and antihypertensive capacity. However, there is little evidence demonstrating its influence on vascular regeneration. Therefore, we evaluated the modulation of carvacrol on endothelial repair induced by endothelial progenitor cells (EPC) in hypertension. Twelve-week-old spontaneously hypertensive rats (SHR) were treated with a vehicle, carvacrol (50 or 100 mg/kg/day), or resveratrol (10 mg/kg/day) orally for four weeks. Wistar Kyoto (WKY) rats were used as the normotensive controls. Their systolic blood pressure (SBP) was measured weekly through the tail cuff. The EPCs were isolated from the bone marrow and peripherical circulation and were quantified by flow cytometry. The functionality of the EPC was evaluated after cultivation through the quantification of colony-forming units (CFU), evaluation of eNOS, intracellular detection of reactive oxygen species (ROS), and evaluation of senescence. The superior mesenteric artery was isolated to evaluate the quantification of ROS, CD34, and CD31. Treatment with carvacrol induced EPC migration, increased CFU formation and eNOS expression and activity, and reduced ROS and senescence. In addition, carvacrol reduced vascular ROS and increased CD31 and CD34 expression. This study showed that treatment with carvacrol improved the functionality of EPC, contributing to the reduction of endothelial dysfunction.

Effect of Extracellular Ribonucleic Acids on Neurovascularization in Osteoarthritis.

Osteoarthritis is a degenerative disease characterized by abnormal neurovascularization at the osteochondral junctions, the regulatory mechanisms of which remain poorly understood. In the present study, a murine osteoarthritic model with augmented neurovascularization at the osteochondral junction is used to examine this under-evaluated facet of degenerative joint dysfunction. Increased extracellular RNA (exRNA) content is identified in neurovascularized osteoarthritic joints. It is found that the amount of exRNA is positively correlated with the extent of neurovascularization and the expression of vascular endothelial growth factor (VEGF). In vitro binding assay and molecular docking demonstrate that synthetic RNAs bind to VEGF via electrostatic interactions. The RNA-VEGF complex promotes the migration and function of endothelial progenitor cells and trigeminal ganglion cells. The use of VEGF and VEGFR2 inhibitors significantly inhibits the amplification of the RNA-VEGF complex. Disruption of the RNA-VEGF complex by RNase and polyethyleneimine reduces its in vitro activities, as well as prevents excessive neurovascularization and osteochondral deterioration in vivo. The results of the present study suggest that exRNAs may be potential targets for regulating nerve and blood vessel ingrowth under physiological and pathological joint conditions.

LncRNA NEAT-2 regulate the function of endothelial progenitor cells in experimental Sepsis model.

Sepsis is a life-threatening disease with a limited effectiveness and the potential mechanism remains unclear. LncRNA NEAT-2 is reported to be involved in the regulation of cardiovascular disease. This study aimed to investigate the function of NEAT-2 in sepsis. We built sepsis animal model with Male Balb/C mice induced by cecal ligation and puncture (CLP). A total of 54 mice were randomly assigned into eight groups: sham operation group (n = 18), CLP group (n = 18), CLP plus si-control group (n = 3), CLP plus si-NEAT2 group (n = 3), CLP plus mimic control group (n = 3), CLP plus miR-320 group (n = 3), CLP plus normal saline group (n = 3), and normal control group (n = 3). The number of peripheral endothelial progenitor cells (EPCs), the expression level of NEAT-2 and miR-320 were detected during progression of sepsis, as well as the number of peripheral EPCs and level of TNF-α, IL-6, VEGF, ALT, AST and Cr. In addition, the function of EPCs was evaluated after NEAT-2 knockdown and miR-320 overexpression in vitro. The number of circulating EPCs increased significantly in sepsis. NEAT-2 expression was significantly increased in the progress of sepsis, accompanied with miR-320 downregulated. NEAT-2 knockdown and miR-320 overexpression attenuated hepatorenal function and increased cytokines in sepsis. Moreover, NEAT-2 knockdown and miR-320 overexpression decreased the proliferation, migration and angiogenesis of endothelial progenitor cells in vitro. LncRNA-NEAT2 regulated the number and function of endothelial progenitor cells via miR-320 in sepsis, which may contribute to the development of novel potential clinical therapy for sepsis.

Endothelial Progenitor Cells and Macrophage Subsets Recruitment in Postischemic Mouse Hind Limbs

Introduction: Peripheral arterial disease (PAD) occurs from atherosclerotic obstruction of arteries in the lower extremities. Restoration of perfusion requires angiogenesis and arteriogenesis through migration and differentiation of endothelial progenitor cells (EPCs) and macrophages at the site of injury. The time of recruitment has not been fully investigated. In this study, we investigated the infiltration of these cells in murine hind limb ischemia (HLI) model of PAD. Methods: EPCs and M1-like and M2-like macrophages from ischemic skeletal muscles were quantified by flow cytometry at day-0, 1, 3, 7, and 14 post-HLI. Results: The abundance of EPCs increased from day 1 and was highest on day 7 until day 14. M1-like population similarly increased and was highest on day 14 during the experiment. M2-like population was significantly greater than M1-like at baseline but surpassed the highest value of M1-like by day 7 during the experiment. Muscle regeneration and capillary density also increased and were highest at days 3 and 7, respectively, during the experiment. All mice achieved near full perfusion recovery by day 14. Conclusion: Thus, we observed a gradual increase in the percentage of EPC’s and this was temporally paralleled with initial increase in M1-like followed by sustained increased in M2-like macrophages and perfusion recovered post-HLI.

GroEL of Porphyromonas gingivalis-induced microRNAs accelerate tumor neovascularization by downregulating thrombomodulin expression in endothelial progenitor cells.

We found that GroEL in Porphyromonas gingivalis accelerated tumor growth and increased mortality in tumor-bearing mice; GroEL promoted proangiogenic function, which may be the reason for promoting tumor growth. To understand the regulatory mechanisms by which GroEL increases the proangiogenic function of endothelial progenitor cells (EPCs), we explored in this study. In EPCs, MTT assay, wound-healing assay, and tube formation assay were performed to analyze its activity. Western blot and immunoprecipitation were used to study the protein expression along with next-generation sequencing for miRNA expression. Finally, a murine tumorigenesis animal model was used to confirm the results of in vitro. The results indicated that thrombomodulin (TM) direct interacts with PI3 K/Akt to inhibit the activation of signaling pathways. When the expression of TM is decreased by GroEL stimulation, molecules in the PI3 K/Akt signaling axis are released and activated, resulting in increased migration and tube formation of EPCs. In addition, GroEL inhibits TM mRNA expression by activating miR-1248, miR-1291, and miR-5701. Losing the functions of miR-1248, miR-1291, and miR-5701 can effectively alleviate the GroEL-induced decrease in TM protein levels and inhibit the proangiogenic abilities of EPCs. These results were also confirmed in animal experiments. In conclusion, the intracellular domain of the TM of EPCs plays a negative regulatory role in the proangiogenic capabilities of EPCs, mainly through direct interaction between TM and PI3 K/Akt to inhibit the activation of signaling pathways. The effects of GroEL on tumor growth can be reduced by inhibiting the proangiogenic properties of EPCs through the inhibition of the expression of specific miRNAs.

Nanofibrous insulin/vildagliptin core-shell PLGA scaffold promotes diabetic wound healing.

Introduction: Slow wound repair in diabetes is a serious adverse event that often results in loss of a limb or disability. An advanced and encouraging vehicle is wanted to enhance clinically applicable diabetic wound care. Nanofibrous insulin/vildagliptin core-shell biodegradable poly (lactic-co-glycolic acid) (PLGA) scaffolds to prolong the effective drug delivery of vildagliptin and insulin for the repair of diabetic wounds were prepared. Methods: To fabricate core-shell nanofibrous membranes, vildagliptin mixture with PLGA, and insulin solution were pumped via separate pumps into two differently sized capillary tubes that were coaxially electrospun. Results and Discussion: Nanofibrous core-shell scaffolds slowly released effective vildagliptin and insulin over 2weeks in vitro migration assay and in vivo wound-healing models. Water contact angle (68.3 ± 8.5° vs. 121.4 ± 2.0°, p = 0.006) and peaked water absorbent capacity (376% ± 9% vs. 283% ± 24%, p = 0.003) of the insulin/vildagliptin core-shell nanofibrous membranes remarkably exceeded those of a control group. The insulin/vildagliptin-loaded core-shell nanofibers improved endothelial progenitor cells migration in vitro (762 ± 77cells/mm2 vs. 424.4 ± 23cells/mm2, p < 0.001), reduced the α-smooth muscle actin content in vivo (0.72 ± 0.23 vs. 2.07 ± 0.37, p < 0.001), and increased diabetic would recovery (1.9 ± 0.3mm2 vs. 8.0 ± 1.4mm2, p = 0.002). Core-shell insulin/vildagliptin-loaded nanofibers extend the drug delivery of insulin and vildagliptin and accelerate the repair of wounds associated with diabetes.

Transplantation of endothelial progenitor cells overexpressing mir-126-3p improves vascular repair in a diabetic rat model.

Transplantation of endothelial progenitor cells overexpressing mir-126-3p improves vascular repair in a diabetic rat model.

Melatonin Inhibits VEGF-Induced Endothelial Progenitor Cell Angiogenesis in Neovascular Age-Related Macular Degeneration.

Neovascular age-related macular degeneration (AMD) is described as abnormal angiogenesis in the retina and the leaking of fluid and blood that generates a huge, dark, blind spot in the center of the visual field, causing severe vision loss in over 90% of patients. Bone marrow-derived endothelial progenitor cells (EPCs) contribute to pathologic angiogenesis. Gene expression profiles downloaded from the eyeIntegration v1.0 database for healthy retinas and retinas from patients with neovascular AMD identified significantly higher levels of EPC-specific markers (CD34, CD133) and blood vessel markers (CD31, VEGF) in the neovascular AMD retinas compared with healthy retinas. Melatonin is a hormone that is mainly secreted by the pineal gland, and is also produced in the retina. Whether melatonin affects vascular endothelial growth factor (VEGF)-induced EPC angiogenesis in neovascular AMD is unknown. Our study revealed that melatonin inhibits VEGF-induced stimulation of EPC migration and tube formation. By directly binding with the VEGFR2 extracellular domain, melatonin significantly and dose-dependently inhibited VEGF-induced PDGF-BB expression and angiogenesis in EPCs via c-Src and FAK, NF-κB and AP-1 signaling. The corneal alkali burn model demonstrated that melatonin markedly inhibited EPC angiogenesis and neovascular AMD. Melatonin appears promising for reducing EPC angiogenesis in neovascular AMD.

Downregulation of miR-125a-5p Promotes Endothelial Progenitor Cell Migration and Angiogenesis and Alleviates Deep Vein Thrombosis in Mice Via Upregulation of MCL-1.

Endothelial progenitor cells (EPCs) contribute to recanalization of deep vein thrombosis (DVT). MicroRNAs (miRNAs) play regulatory roles in functions of EPCs, which is becoming a promising therapeutic choice for thrombus resolution. The main purpose of this study was to explore the effect of miR-125a-5p on EPC functions in deep vein thrombosis (DVT). EPCs were isolated from the peripheral blood of patients with DVT. In DVT mouse models, DVT was induced by stenosis of the inferior vena cava (IVC). The levels of miR-125a-5p and myeloid cell leukemia sequence 1 (MCL-1) in EPCs and thrombi of DVT mice were detected by RT-qPCR. EPC migration, angiogenesis, and apoptosis were estimated by Transwell assay, tube formation assay, and flow cytometry analysis. Luciferase reporter assay was utilized for detecting the binding of miR-125a-5p and MCL-1. The phosphorylation of PI3K and AKT was estimated by western blot. DVT formation in vivo was observed through hematoxylin-eosin (H&E) staining. The expression of thrombus resolution marker, CD34 molecule (CD34), in the thrombi was measured by immunofluorescence staining. MiR-125a-5p upregulation repressed EPC migration and angiogenesis and facilitated apoptosis. MiR-125a-5p downregulation showed the opposite effect. MCL-1 was targeted and negatively regulated by miR-125a-5p. Additionally, miR-125a-5p inhibited the PI3K/AKT pathway in EPCs. Inhibition of MCL-1 or PI3K/AKT pathway reversed the effect of miR-125a-5p knockdown on EPC functions. The in vivo experiments revealed that miR-125a-5p downregulation repressed thrombus formation and promoted the homing capability of EPCs to the thrombosis site, thereby alleviating DVT mice. Downregulation of miR-125a-5p promotes EPC migration and angiogenesis by upregulating MCL-1, thereby enhancing EPC homing to thrombi and facilitating thrombus resolution.

The Mechanism of miR-21-5p/TSP-1-Mediating Exercise on the Function of Endothelial Progenitor Cells in Aged Rats.

(1) Background: The declined function of peripheral circulating endothelial progenitor cells (EPCs) in aging individuals resulted in decreased endothelial cell regeneration and vascular endothelial function. Improving EPCs function in aging individuals plays an important role in preventing cardiovascular diseases. (2) Methods: Thirty aged (18-month-old) male Sprague-Dawley rats were randomly divided into control and exercise groups. An aerobic exercise intervention was performed 5 days/week for 8 weeks. EPCs functions, miR-21-5p, and TSP-1 expressions were detected after the intervention. The senescence rate, proliferation, and migration of EPCs were examined after overexpression of miR-21-5p and inhibition of TSP-1 expression. (3) Results: The senescence rate, proliferation, and migration of EPCs in exercise groups were significantly improved after exercise intervention. The miR-21-5p expression was increased and the TSP-1 mRNA expression was decreased in the EPCs after the intervention. miR-21-5p overexpression can improve EPCs function and inhibit TSP-1 expression but has no effect on senescence rate. Inhibition of TSP-1 expression could improve the function and reduce the senescence rate. (4) Conclusions: Our results indicate that long-term aerobic exercise can improve the functions of EPCs in aging individuals by downregulating TSP-1 expression via miR-21-5p, which reveals the mechanism of exercise in improving cardiovascular function.