Impaired Angiogenesis Research Articles

The Circadian System Is Essential for the Crosstalk of VEGF-Notch-mediated Endothelial Angiogenesis in Ischemic Stroke.

Ischemic stroke is a major public health problem worldwide. Although the circadian clock is involved in the process of ischemic stroke, the exact mechanism of the circadian clock in regulating angiogenesis after cerebral infarction remains unclear. In the present study, we determined that environmental circadian disruption (ECD) increased the stroke severity and impaired angiogenesis in the rat middle cerebral artery occlusion model, by measuring the infarct volume, neurological tests, and angiogenesis-related protein. We further report that Bmal1 plays an irreplaceable role in angiogenesis. Overexpression of Bmal1 promoted tube-forming, migration, and wound healing, and upregulated the vascular endothelial growth factor (VEGF) and Notch pathway protein levels. This promoting effect was reversed by the Notch pathway inhibitor DAPT, according to the results of angiogenesis capacity and VEGF pathway protein level. In conclusion, our study reveals the intervention of ECD in angiogenesis in ischemic stroke and further identifies the exact mechanism by which Bmal1 regulates angiogenesis through the VEGF-Notch1 pathway.

Multifunctional Scaffold for Osteoporotic Pathophysiological Microenvironment Improvement and Vascularized Bone Defect Regeneration.

Osteoporosis is a degenerative bone disease resulting from bone homeostasis imbalance regulated by osteoblasts and osteoclasts. Treating osteoporotic bone defects tends to be more difficult due to suppressed osteogenic differentiation, hyperactive osteoclastogenesis, and impaired angiogenesis. Hence, a drug carrier system composed of gelatin-coated hollow mesoporous silica nanoparticles (HMSNs/GM) loaded with pro-osteogenic parathyroid (PTH) and anti-osteoclastogenic alendronate (ALN) is constructed and compounded into calcium magnesium phosphate cement (MCPC). The spatial-temporal release of ions and drugs, controllable degradation rate, and abundant pore structure of MCPC composites enhance osteoporotic bone regeneration in ovariectomized rats by accelerating vascularization, promoting osteogenic differentiation and mineralization, and inhibiting osteoclastogenesis and bone resorption. The MCPC/HMSNs@ALN-PTH/GM demonstrates a synergistic threefold effect on osteogenesis, osteoclastogenesis, and angiogenesis. It improves the osteoporotic pathophysiological microenvironment and promotes osteoporotic vascularized bone defect regeneration, holding huge potential for other functional biomaterials design and clinical management.

Multifunctional, Adhesive, and PDA-Coated Bioactive Glass Reinforced Composite Hydrogel for Regenerative Wound Healing.

Effective wound management imposes several challenges in clinical outcomes due to the complexity of the wound microenvironment, bacterial infections, impaired angiogenesis, aggravated inflammation, and enduring pain. In addition, adhesion on wet biological tissue is another extremely challenging task. Addressing all the issues is necessary for an effective wound healing process. Herein, we developed a unique multifunctional, adhesive composite hydrogel composed of gelatin, chitosan, polydopamine-coated bioactive glass (BG), and curcumin-capped silver nanoparticles (Cur-AgNPs) to target the multifaceted complexity of the wound. The PDA-coated BG serves multiple purposes: (1) adhesivity: catechol groups of PDA and Ca ion released from BG chelate the group present in the hydrogel network and surrounding tissues, (2) angiogenesis: promotes vascularization due to the release of Si from BG, and (3) BG also serves as the "reservoir" for the pain-relieving diclofenac sodium drug with a sustained-release behavior. Cur-AgNPs provide excellent bactericidal and anti-inflammatory properties to the composite hydrogel. In situ application of the composite hydrogel could serve the purpose of a "skin biomimetic" and work as a barrier along with bactericidal properties to inhibit the microbial growth. The multifunctional composite hydrogel (MCH) targeted multiple aspects of wound repair including pain alleviation, elimination of microbes (up to 99%), reduced inflammation, high adhesivity, and increased angiogenesis for effective skin regeneration. The MCH showed excellent wound healing potential as significant wound closure was observed at day 7 and also significantly upregulated the expression of crucial genes involved in the skin regeneration process along with increasing vascularization in the wound area.

The Epidermal Keratinocyte as a Therapeutic Target for Management of Diabetic Wounds.

Diabetes mellitus (DM) is an important cause of chronic wounds and non-traumatic amputation. The prevalence and number of cases of diabetic mellitus are increasing worldwide. Keratinocytes, the outermost layer of the epidermis, play an important role in wound healing. A high glucose environment may disrupt the physiologic functions of keratinocytes, resulting in prolonged inflammation, impaired proliferation, and the migration of keratinocytes and impaired angiogenesis. This review provides an overview of keratinocyte dysfunctions in a high glucose environment. Effective and safe therapeutic approaches for promoting diabetic wound healing can be developed if molecular mechanisms responsible for keratinocyte dysfunction in high glucose environments are elucidated.

Vascular therapy for Duchenne muscular dystrophy (DMD).

Duchenne muscular dystrophy (DMD) is a progressive disease characterized by the wasting of the muscles that eventually lead to difficulty moving and, ultimately, premature death from heart and respiratory complications. DMD deficiency is caused by mutations in the gene encoding dystrophin, which prevents skeletal muscle, cardiac muscle, and other cells from producing the functional protein. Located on the cytoplasmic face of the plasma membrane of muscle fibers, dystrophin serves as a component of the dystrophin glycoprotein complex (DGC), mechanically reinforces the sarcolemma, and stabilizes the DGC, preventing it from contraction-mediated muscle degradation. In DMD muscle, dystrophin deficiency leads to progressive fibrosis, myofiber damage, chronic inflammation, and dysfunction of the mitochondria and muscle stem cells. Currently, DMD is incurable, and treatment involves the administration of glucocorticoids in order to delay disease progression. In the presence of developmental delay, proximal weakness, and elevated serum creatine kinase levels, a definitive diagnosis can usually be made after an extensive review of the patient's history and physical examination, as well as confirmation through muscle biopsy or genetic testing. Current standards of care include the use of corticosteroids to prolong ambulation and delay the onset of secondary complications, including respiratory muscle and cardiac functions. However, different studies have been carried out to show the relationship between vascular density and impaired angiogenesis in the pathogenesis of DMD. Several recent studies on DMD management are vascular targeted and focused on ischemia as a culprit for the pathogenesis of DMD. This review critically discusses approaches-such as modulation of nitric oxide (NO) or vascular endothelial growth factor (VEGF)-related pathways-to attenuate the dystrophic phenotype and enhance angiogenesis.

Current Trends in Vascular Biomarkers for Systemic Sclerosis: A Narrative Review

Systemic sclerosis (SSc, scleroderma) is a multifaceted rare connective tissue disease whose pathogenesis is dominated by immune dysregulation, small vessel vasculopathy, impaired angiogenesis, and both cutaneous and visceral fibrosis. Microvascular impairment represents the initial event of the disease, preceding fibrosis by months or years and accounting for the main disabling and/or life-threatening clinical manifestations, including telangiectasias, pitting scars, periungual microvascular abnormalities (e.g., giant capillaries, hemorrhages, avascular areas, ramified/bushy capillaries) clinically detectable by nailfold videocapillaroscopy, ischemic digital ulcers, pulmonary arterial hypertension, and scleroderma renal crisis. Despite a variety of available treatment options, treatment of SSc-related vascular disease remains problematic, even considering SSc etherogenity and the quite narrow therapeutic window. In this context, plenty of studies have highlighted the great usefulness in clinical practice of vascular biomarkers allowing clinicians to assess the evolution of the pathological process affecting the vessels, as well as to predict the prognosis and the response to therapy. The current narrative review provides an up-to-date overview of the main candidate vascular biomarkers that have been proposed for SSc, focusing on their main reported associations with characteristic clinical vascular features of the disease.

Epigallocatechin gallate-loaded pH-responsive dressing with effective antioxidant, antibacterial and anti-biofilm properties for wound healing

High blood glucose levels, excessive production of reactive oxygen species (ROS), unbalanced inflammatory responses and impaired angiogenesis render chronic wounds more likely to be colonized by bacteria which can form biofilms, leading to recurrent infections and prolonging disunion. The pH-responsive fibers of poly (vinyl alcohol) (PVA)/poly (acrylic acid) (PAA) -epigallocatechin gallate (EGCG) have been constructed. The fibers were able to swell (pH > 7.4) /shrink (pH < 6.5) reversibly with changes in wound pH, controlling the rate of drug release and thus dynamically modulating the complex inflammatory environment of the wound. At the phase of bacterial infection (pH = 7–9), the polycarboxylic acid groups in the network ionized, and the dynamic hydrogen bond between EGCG and PVA and PAA was broke, triggered an increased release of EGCG (87.4 %). Thereafter, the EGCG cleared excess ROS (greater than80.0 %) from the wound and showed significant antibacterial activity against S. aureus (98 %) and Pseudomonas aeruginosa (96.7 %), inhibited biofilm formation (74 %). At the proliferative phase, the wound switched to acidic (pH ∼ 6.5). Fibers swelled less and tended to shrink. The release of EGCG was slowed down (45.8 %) to promote macrophage polarization and remodel the wound microenvironment.

Liraglutide promotes angiogenesis in adipose tissue via suppression of adipocyte-derived IL-6

Accumulating evidence suggests that Liraglutide is a favorable treatment for obese people. Obesity induces cellular senescence and accumulated senescent adipocytes in adipose tissue. However, the role of Liraglutide in adipose tissue (AT) senescence and the underlying mechanisms remain obscure. In this study, we found that HFD induces adipocyte senescence and impaired angiogenesis in AT. The deleterious effects provoked unhealthy adipose tissue remodeling and metabolic disturbance. In contrast, treatment of Liraglutide promoted weight reduction, alleviated adipose tissue senescence, and improved angiogenesis in AT. Notably, we demonstrated that Liraglutide promotes angiogenesis in AT dependent on adipocyte-derived IL-6. These findings revealed distinctive roles of Liraglutide in the regulation of adipocyte senescence and provide a therapeutic potential to obesity-associated metabolic disorders.

Endothelial cells LEENE on noncoding RNAs in diabetic vasculopathy.

Long noncoding RNAs (lncRNAs) have emerged as key mediators of regulated gene expression in diverse biologic contexts, including cardiovascular disease. In this issue of the JCI, Tang, Luo, and colleagues explored the contributions of lncRNAs in diabetic vasculopathy. The authors identified the lncRNA LEENE as a key mediator of angiogenesis and ischemic response. In a model of diabetic peripheral arterial disease, loss of LEENE led to impaired vascular perfusion, while its overexpression rescued the ischemic defect. The authors used unbiased chromatin affinity assays to decipher LEENE's interactome and mode of action. These findings offer insights as to why patients with diabetes are uniquely susceptible to developing peripheral vascular disease and fill important gaps in our understanding of mechanisms that connect metabolic dysregulation with impaired angiogenesis.

Long noncoding RNA LEENE promotes angiogenesis and ischemic recovery in diabetes models.

Impaired angiogenesis in diabetes is a key process contributing to ischemic diseases such as peripheral arterial disease. Epigenetic mechanisms, including those mediated by long noncoding RNAs (lncRNAs), are crucial links connecting diabetes and the related chronic tissue ischemia. Here we identify the lncRNA that enhances endothelial nitric oxide synthase (eNOS) expression (LEENE) as a regulator of angiogenesis and ischemic response. LEENE expression was decreased in diabetic conditions in cultured endothelial cells (ECs), mouse hind limb muscles, and human arteries. Inhibition of LEENE in human microvascular ECs reduced their angiogenic capacity with a dysregulated angiogenic gene program. Diabetic mice deficient in Leene demonstrated impaired angiogenesis and perfusion following hind limb ischemia. Importantly, overexpression of human LEENE rescued the impaired ischemic response in Leene-knockout mice at tissue functional and single-cell transcriptomic levels. Mechanistically, LEENE RNA promoted transcription of proangiogenic genes in ECs, such as KDR (encoding VEGFR2) and NOS3 (encoding eNOS), potentially by interacting with LEO1, a key component of the RNA polymerase II-associated factor complex and MYC, a crucial transcription factor for angiogenesis. Taken together, our findings demonstrate an essential role for LEENE in the regulation of angiogenesis and tissue perfusion. Functional enhancement of LEENE to restore angiogenesis for tissue repair and regeneration may represent a potential strategy to tackle ischemic vascular diseases.

Role of poFUT1 and O-fucosylation in placental angiogenesis†.

Trophoblast cells are critical to placental angiogenesis in the first trimester of pregnancy. Dysfunction of trophoblast leads to defective vascular remodeling and impaired angiogenesis, which is believed as the major cause of placental insufficiency and pregnancy failure. Protein O-fucosyltransferase 1 (poFUT1) is mainly responsible for O-fucosylated glycan biosynthesis on glycoproteins, and poFUT1 deficiency causes embryonic lethality in mice. However, the expression and function of poFUT1 in trophoblast-mediated human placental vessel formation remain unclear. In the current study, we showed that fewer blood vessels were observed in the villi and decidua of miscarriage patients than in normal pregnancy women. The expression of poFUT1 was decreased in the trophoblast cells of miscarriage patients compared with normal pregnancy women. Employing HTR/SVneo cells and an in vivo chorioallantoic membrane assay, we demonstrated that poFUT1 promoted the proliferation, migration ability, and angiogenesis potential of trophoblast cells. The results also indicated that poFUT1 upregulated O-fucosylation on uPA, facilitated the binding of uPA and uPAR, activated the RhoA signaling pathway, and further enhanced the angiogenic capacity of trophoblast cells. Our study provides new evidence for a relationship between poFUT1/O-fucosylation and placental angiogenesis. These findings may provide potential diagnostic biomarkers and targeted therapies for miscarriage patients.

Y-27632 Impairs Angiogenesis on Extra-Embryonic Vasculature in Post-Gastrulation Chick Embryos

Y-27632 inhibits Rho-associated coiled-coil-containing protein kinase (ROCK) signaling, which is involved in various embryonic developmental processes, including angiogenesis, by controlling actin cytoskeleton assembly and cell contractility. Administration of Y-27632 impairs cytoskeletal arrangements in post-gastrulation chick embryos, leading to ventral body wall defects (VBWDs). Impaired angiogenesis has been hypothesized to contribute to VBWDs. ROCK is essential in transmitting signals downstream of vascular endothelial growth factor (VEGF). VEGF-mediated angiogenesis induces gene expressions and alterations of the actin cytoskeleton upon binding to VEGF receptors (VEGFRs). The aim of this study was to investigate effects of Y-27632 on angiogenesis in post-gastrulation chick embryos during early embryogenesis. After 60 h incubation, embryos in shell-less culture were treated with Y-27632 or vehicle for controls. Y-27632-treated embryos showed reduced extra-embryonic blood vessel formation with impaired circulation of the yolk sac, confirmed by fractal analysis. Western blot confirmed impaired ROCK downstream signaling by decreased expression of phosphorylated myosin light chain. Interestingly, RT-PCR demonstrated increased gene expression of VEGF and VEGFR-2 1 h post-treatment. Protein levels of VEGF were higher in Y-27632-treated embryos at 8 h following treatment, whereas no difference was seen in membranes. We hypothesize that administration of Y-27632 impairs vessel formation during angiogenesis, which may contribute to failure of VWB closure, causing VBWDs.

Preeclampsia and the Kidney: Pathophysiology and Clinical Implications.

Preeclampsia and other hypertensive disorders of pregnancy are major contributors to maternal morbidity and mortality worldwide. This group of disorders includes chronic hypertension, gestational hypertension, preeclampsia, preeclampsia superimposed on chronic hypertension, and eclampsia. The body undergoes important physiological changes during pregnancy to allow for normal placental and fetal development. Several mechanisms have been proposed that may lead to preeclampsia, including abnormal placentation and placental hypoxia, impaired angiogenesis, excessive pro-inflammatory response, immune system imbalance, abnormalities of cellular senescence, alterations in regulation and activity of angiotensin II, and oxidative stress, ultimately resulting in upregulation of multiple mediators of endothelial cell dysfunction leading to maternal disease. The clinical implications of preeclampsia are significant as there are important short-term and long-term health consequences for those affected. Preeclampsia leads to increased risk of preterm delivery and increased morbidity and mortality of both the developing fetus and mother. Preeclampsia also commonly leads to acute kidney injury, and women who experience preeclampsia or another hypertensive disorder of pregnancy are at increased lifetime risk of chronic kidney disease and cardiovascular disease. An understanding of normal pregnancy physiology and the pathophysiology of preeclampsia is essential to develop novel treatment approaches and manage patients with preeclampsia and hypertensive disorders of pregnancy. © 2023 American Physiological Society. Compr Physiol 13:4231-4267, 2023.

Mesenchymal Stem Cell Derived Extracellular Vesicles: Promising Nanomedicine for Cutaneous Wound Treatment.

A skin wound represents a rupture caused by external damage or the existence of underlying pathological conditions. Sometimes, skin wound healing processes may place a heavy burden on patients, families, and society. Wound healing processes mainly consist of several continuous, dynamic, but overlapping stages, namely, the coagulation stage, inflammation stage, proliferation stage, and remodeling stage. Bacterial infection, excessive inflammation, impaired angiogenesis, and scar formation constitute the four significant factors impeding the recovery efficacy of skin wounds. This encourages scientists to develop multifunctional nanomedicines to meet challenging needs. As we know, mesenchymal stem cells (MSCs) have been widely explored for wound repair owing to their unique capability for self-renewal and multipotency. However, problems including immune concerns and legal restrictions should be properly resolved before MSC-based therapeutics are safely and widely used in clinics. Besides, maintaining the high viability/proliferation capability of MSCs during administration processes and therapy procedures is also one of the biggest technical bottlenecks. Extracellular vesicles (EVs) are cell-derived nanovesicles, that not only possess the basic characteristics and functions of their corresponding maternal cells but also contain several outstanding advantages including abundant sources, excellent biocompatibility, and convenient administration routes. Furthermore, the membrane surface and cavity are easy to flexibly modify to meet versatile application needs. Recently, MSC-derived EVs have emerged as promising therapeutics for skin wound repair. However, current reviews are too broad and rarely focused on the specific roles of EVs in the different stages of wound recovery. Therefore, it is quite necessary to demonstrate the significance of stem cell-derived EVs in promoting wound healing from several specific aspects. Here, this review primarily tries to provide critical comments on current advances in EVs derived from MSCs for wound repair, particularly elaborating on their impressive roles in effectively eliminating infections, inhibiting inflammation, promoting angiogenesis, and reducing scar formation. Last but not least, current limitations and future prospects of EVs derived from MSCs in the areas of wound repair are also objectively analyzed.

TsRNA-15797-modified BMSC-derived exosomes mediate LFNG to induce angiogenesis in osteonecrosis of the femoral head.

Osteonecrosis of the femoral head (ONFH) is an ischemic disease characterized by the impairment of angiogenesis. We have previously elucidated the role of tsRNAs and BMSC exosomes in ONFH, but whether tsRNA-modified BMSC exosomes promote angiogenesis in ONFH remains unclear. The expression of angiogenesis-related tsRNA in plasma exosomes from ONFH patients was examined by q-PCR. The function of tsRNA in HUVECs was identified by CCK-8 and angiogenesis assay. Exosomes purified from tsRNA-15797 overexpressed BMSCs were cocultured with HUVECs to examine their role in angiogenesis. The molecule mechanism of tsRNA-15797-modified exosomes was explored by RNA sequencing, dual-luciferase assay, and immunofluorescence. A tRNA-derived small RNA tsRNA-15797 was down-regulated in plasma exosomes of ONFH patients. We found the effects of BMSCs-derived exosomes on accelerating HUVECs angiogenesis and migration, which were further enhanced after overexpressing tsRNA-15797. Besides, overexpression of tsRNA-15797 would lead to down-regulation of LFNG correlated with angiogenesis. tsRNA-15797 could directly interact with LFNG. We demonstrated that LNFG overexpression weakened the pro angiogenic and migratory effects of tsRNA-15797-modified BMSCs-derived exosomes. We successfully constructed tsRNA-15797-modified BMSC-derived exosomes and demonstrated that it induced the angiogenesis of HUVECs by targeting the down-regulation of LFNG. Thus, tsRNA-15797-loaded BMSCs-derived exosomes may be a potential target therapy drug for ONFH.

PS-BPB04-7: PRO-ANGIOGENIC EFFECTS OF LSKL, A THROMBOSPONDIN-1 INHIBITOR, IN HUMAN AND EXPERIMENTAL MODELS OF PREECLAMPSIA

Introduction: Preeclampsia (PE) is a hypertensive disorder of pregnancy characterized by blood pressure above 140/90 mmHg. It accounts for 10% of all pregnancies and is responsible for 25% of preterm births and low birth weight. To date, no medications can treat or prevent PE. We identified an activation of the anti-angiogenic protein thrombospondin-1 (THBS1) in human and experimental preeclampsia. THBS1 is also a main activator of TGF-β. We postulate that THBS1-mediated TGF-β activation may contribute to impair placental angiogenesis during PE. Objective: We aimed to test the effects of LSKL, an inhibitor of THBS1-mediated TGF-β activation, on angiogenesis in placentas of a mouse model of PE and in human placental endothelial cells. Methods: Peptide LSKL or its control peptide SLLK (280 μM in 0.5 ml saline, s.c.) was administered at gestational day (GD) 14.5 in heterozygous transgenic mice overexpressing human renin and human angiotensinogen and controls (C57BL/6). Placentas (n = 12/group) were removed at GD 18.5. Protein expression of TGF-β1, TGF-β2, total and phosphorylated SMAD2 were assessed by western blot of placental lysates. Placental angiogenesis was assessed by CD31+ immunohistochemistry in placental sections. CD31+ endothelial cells were extracted by magnetic sorting from human placentas (n = 4) of healthy pregnancies. Cells (2–5 passages) were treated with LSKL or SLLK (30 μM) under hypoxia (0.5% vs. 8% O2) or thrombin (10 u/mL) exposure (4 hours). THBS1 expression in placental endothelial cells was assessed by immunofluorescence. Cell angiogenesis was quantified by the number of closed tubes formed on matrigel (per 15,000 cells, 4 hours). Results: Maternal LSKL treatment significantly reduced the expression of TGF-β2 (P &lt; 0.01) and SMAD2 phosphorylation (P &lt; 0.05) while improving angiogenesis (P &lt; 0.05) in placentas of transgenic preeclamptic mouse compared to controls. In human placental endothelial cells, both thrombin (P &lt; 0.05) and hypoxia (P &lt; 0.05) significantly increased THBS1 expression. Thrombin (P &lt; 0.01) and hypoxia (P &lt; 0.05) significantly impaired cell angiogenesis on matrigel (P &lt; 0.01), which was prevented by LSKL treatment (P &lt; 0.01). In human cells, LSKL similarly reduced TGB-β2 (p &lt; 0.05) and phospho-SMAD2 (P &lt; 0.05) expressions under thrombin and hypoxia cell exposure. Conclusion: Our results describe a significant pro-angiogenic effect of LSKL treatment by regulating THBS1 and TGF-β2 mechanisms in human and experimental models of PE.

A mace-like heterostructural enriched injectable hydrogel composite for on-demand promotion of diabetic wound healing.

Wound healing is a multifaceted process that involves hemostasis, inflammation, proliferation, and remodeling stages. Diabetic wounds affect the transition of the organized phases and result in delayed healing due to impaired angiogenesis, chronic inflammation, bacterial infection, and insufficient growth factors. Multifunctional heterostructural nanoparticles enriched minimally invasive hydrogels for on-demand procedural distribution to aid wound healing at various stages has become a promising strategy. Herein, silk fibroin-hyaluronic acid based injectable hydrogels incorporated with mace-like Au-CuS heterostructural nanoparticles (gAu-CuS HSs) were used to cure diabetic wounds. SF-HA and the rough surface of gAu-CuS HSs confer a synergistic hemostatic phase with a nano-bridge effect and rapidly close the wounds. During the inflammation stage, gAu-CuS HSs perform in-space resonance energy transfer under 808 nm laser irradiation which in return produces reactive oxygen species for bacterial destruction. The unusual mace-like rough structure of nanoparticles causes macrophage transfer to the M2 phenotype, regulates cytokine expression (interleukin 6, transforming factor-β1, interferon γ, and interleukin-10), promotes angiogenesis, and promotes cell multiplication and fibroblast emigration to the wound area during the proliferation and remodeling phase. Overall, the gAu-CuS HSs reinforced injectable hydrogel programmatically accelerates wound healing and could represent a versatile strategy for advanced diabetic wound healing.

Single-cell RNA-seq and bulk-seq identify RAB17 as a potential regulator of angiogenesis by human dermal microvascular endothelial cells in diabetic foot ulcers.

Angiogenesis is crucial in diabetic wound healing and is often impaired in diabetic foot ulcers (DFUs). Human dermal microvascular endothelial cells (HDMECs) are vital components in dermal angiogenesis; however, their functional and transcriptomic characteristics in DFU patients are not well understood. This study aimed to comprehensively analyse HDMECs from DFU patients and healthy controls and find the potential regulator of angiogenesis in DFUs. HDMECs were isolated from skin specimens of DFU patients and healthy controls via magnetic-activated cell sorting. The proliferation, migration and tube-formation abilities of the cells were then compared between the experimental groups. Both bulk RNA sequencing (bulk-seq) and single-cell RNA-seq (scRNA-seq) were used to identify RAB17 as a potential marker of angiogenesis, which was further confirmed via weighted gene co-expression network analysis (WGCNA) and least absolute shrink and selection operator (LASSO) regression. The role of RAB17 in angiogenesis was examined through in vitro and in vivo experiments. The isolated HDMECs displayed typical markers of endothelial cells. HDMECs isolated from DFU patients showed considerably impaired tube formation, rather than proliferation or migration, compared to those from healthy controls. Gene set enrichment analysis (GSEA), fGSEA, and gene set variation analysis (GSVA) of bulk-seq and scRNA-seq indicated that angiogenesis was downregulated in DFU-HDMECs. LASSO regression identified two genes, RAB17 and CD200, as characteristic of DFU-HDMECs; additionally, the expression of RAB17 was found to be significantly reduced in DFU-HDMECs compared to that in the HDMECs of healthy controls. Overexpression of RAB17 was found to enhance angiogenesis, the expression of hypoxia inducible factor-1α and vascular endothelial growth factor A, and diabetic wound healing, partially through the mitogen-activated protein kinase/extracellular signal-regulated kinase signalling pathway. Our findings suggest that the impaired angiogenic capacity in DFUs may be related to the dysregulated expression of RAB17 in HDMECs. The identification of RAB17 as a potential molecular target provides a potential avenue for the treatment of impaired angiogenesis in DFUs.

In vitro and in vivo effect of novel GA-CSNPs loaded col-fibrin nanocomposite scaffold on diabetic wound healing.

A non-healing wound is a common problem associated with diabetes mellitus. Chronic inflammation, challenging re-epithelization, unusual growth factors, and impaired angiogenesis are the multifactorial events that contribute to impaired wounds. Hence, in the present work, an innovative GA-CSNPs nanocomposite scaffold has been fabricated by integrating Gallic acid (GA) loaded chitosan nanoparticles (GA-CSNPs) into a genipin crosslinked collagen-fibrin (Col-fibrin) scaffold as wound dressing material. The in vitro RT-PCR study carried out using NIH/3T3 mouse fibroblast cells showed that treatment with GA-CSNPs nanocomposite scaffold aids in an upsurge in the expression of Col-I, III, and VEGF, which further supports the synthesis of extracellular matrix, increases neovascularization and development of the established vascular system. In vivo wound contraction study results revealed that diabetic wounds treated with GA-CSNPs nanocomposite scaffold show a faster rate of wound closure (p < .001), histopathology results showed accelerated fibroblast cell migration, reduction of the inflammatory cells, enhanced collagen along with hexosamine synthesis. In addition, immunohistochemistry results showed increased vascularization, a significant decrease in macrophage recruitment, and reduced expression of MMP-9 compared to the Col-fibrin scaffold and Control groups. Overall data suggest that the fabricated GA-CSNPs nanocomposite porous 3-D scaffold can be a hopeful therapeutic choice for diabetic wound management.

Impairment of endothelial progenitor cells in women after kidney transplantation.

The long-term survival of kidney transplant patients has substantially improved. However, there is a higher risk for cardiovascular events after transplantation, partly due to immunosuppression. A diminished number of endothelial progenitor cells (EPCs), which play an important role in angiogenesis and the repair of endothelial damage, is associated with an increased cardiovascular risk. The aim of this study was to evaluate whether kidney transplantation affects EPCs in women. Twenty-four healthy women and 22 female kidney transplant recipients were recruited. The ratio of angiogenic and non-angiogenic circulating progenitor cells (CPCs) was determined by multicolor flow cytometry and related to clinical parameters. Cord blood-derived endothelial colony-forming cells (ECFCs), a proliferative subgroup of endothelial progenitor cells, were treated with pooled sera from transplant patients or healthy controls and tested for their functional integrity using in vitro models. Kidney transplant recipients displayed a reduced ratio of angiogenic and non-angiogenic CPCs compared to healthy controls. Differences were especially pronounced in premenopausal women. Exposure to sera of transplanted women led to a significant impairment of ECFC proliferation, migration and angiogenesis ability. Alterations of EPC populations may contribute to the higher cardiovascular risks after organ transplantation and should be considered in therapeutic strategies.