Angiogenesis最新文献

Wound healing is an essential repair process, and impaired wound healing is a common and sometimes debilitating medical problem. Despite advances in wound healing approaches, optimal management strategies are lacking, partly due to an incomplete understanding of the complex pathophysiology of this process. Here we show that Ang2, a previously known ligand for the Tie2 receptor, also binds to fibroblast growth factor receptor 2 (FGFR2) independently of Tie2 and attenuates FGF/FGFR2 signaling in endothelial cells. Functionally, Ang2 inhibits endothelial cell migration induced by FGF. In mouse, topical Ang2 delays the healing of skin wounds, associated with reduced wound angiogenesis and recruitment of mesenchymal-type cells. Additionally, topical AMG386, a blocker of Ang1/Ang2 binding to Tie2 and systemic REGN910, a blocker of Ang2 binding to Tie2, accelerate wound repair, associated with increased wound angiogenesis and recruitment of inflammatory cells. These results identify the tyrosine kinase FGFR2 as a previously unrecognized Ang2 receptor, explaining some of the context-dependent functions of Ang2 in endothelial cells. Since Ang2 is induced in cutaneous wounds and endogenous FGF/FGFR2 is essential for wound repair, Ang2 blockade holds promise as a new evidence-based therapeutic option to promote wound repair.

Epigenetics is increasingly recognized as a crucial factor in angiogenesis. Ubiquitin-like with PHD and RING Finger Domains 1 (UHRF1) is an important epigenetic regulatory protein involved in regulating cellular life processes, developing many diseases. However, its potential role in regulating embryonic vascular development and postnatal angiogenesis is unclear. Our study found that endothelial cell-specific UHRF1 knockout mice showed obvious developmental disorders at the embryonic stage (E11.5-15.5), including impaired development of the individual embryo size and organs, sparse vascularity in the yolk sac, or even death. In the lower limb ischemia model, UHRF1 expression in ischemic muscle tissues of mice is proportionate to the regeneration of blood vessels. To confirm the specific inhibition of UHRF1, we transfected an adeno-associated virus serotype 9 which inserted a TIE-2 promoter and mediated the delivery of short hairpin RNA (AAV9-TIE-2-shUHRF1) into mouse vascular endothelial cells to knock down UHRF1 specifically. We observed that the knockdown of UHRF1 in endothelial cells results in poorer lower limb perfusion in mice. Mechanically, UHRF1 knockdown decreased the tube-forming capacity of ECFCs, whereas overexpression of UHRF1 by diabetic ECFCs where UHRF1 expression is typically downregulated significantly increased the tube-forming capacity of the cells. RNAseq and related bioinformatics analyses showed that differentially expressed genes (DEGs) were mainly involved in angiogenesis-related pathways. The results of qPCR and western blot showed that the protein and mRNA levels of angiogenesis-related factors (VEGF, PDGF, and ANGPT1), as well as vascular endothelial surface marker molecules (VEGFR2, CD31, and c-Kit), were down-regulated accordingly. Furthermore, ChIP experiments showed that UHRF1 was able to bind the promoters of VEGFR2 and CD31, affecting the levels of histone-methylated protein (H3K4me3 and H3K27me3) enriched in the promoter region. However, the expression of CD31 and VEGFR2 can be reversed separately after the transformation of different histone-methylated protein levels (H3K4me3 and H3K27me3). Taken together, UHRF1 may regulate angiogenic gene expression and vascular endothelial cell differentiation through epigenetic mechanisms and is essential for angiogenesis.

Vascular endothelial cells in vivo are exquisitely regulated by their local environment, which is disrupted or absent when using methods such as FACS sorting of cells isolated from animals or in vitro cell culture. Here, we profile the gene expression patterns of undisturbed endothelial cells in living animals using a novel “AngioTag” zebrafish transgenic line that permits isolation of actively translating mRNAs from endothelial cells in their native environment. This transgenic line uses the endothelial cell-specific kdrl promoter to drive expression of an epitope tagged Rpl10a 60 S ribosomal subunit protein, allowing for Translating Ribosome Affinity Purification (TRAP) of actively translating endothelial cell mRNAs. By performing TRAP-RNAseq on AngioTag animals, we demonstrate strong enrichment of endothelial-specific genes and have uncovered both novel endothelial genes and unique endothelial gene expression signatures for different adult organs. Finally, we generated a versatile “UAS: RiboTag” transgenic line to allow a wider array of different zebrafish cell and tissue types to be examined using TRAP-RNAseq methods. These new tools offer an unparalleled resource to study the molecular identity of cells in their normal in vivo context.

Thoracic aortic aneurysm (TAA) is life-threatening once developing to sudden dissection (TAAD) or rupture. The pathogenesis of TAA remains poorly understood and there is no effective pharmacologic therapy. Increased aortic angiogenesis has been recognized as a key factor contributing to TAA formation, yet the regulatory mechanisms governing this process remain unclear. Here we found that the mRNA and protein levels of Sema3A were significantly decreased in human TAA/TAAD tissues compared to non-TAA aortic tissues. Global or vascular smooth muscle cells (VSMCs)-specific overexpression of Sema3A significantly alleviated the progression of β-aminopropionitrile fumarate (BAPN)-induced TAA and reduced TAAD incidence, whereas VSMCs-specific knockout of Sema3A aggravated TAA and increased TAAD incidence, in mice. Sema3A was leadingly expressed in the VSMCs, and the VSMCs-derived Sema3A protected TAA mainly via binding to NRP1 on the endothelial cells (ECs) and inhibiting the downstream ERK signaling, and thereby suppressing aortic neovascularization, inflammation and extracellular matrix (ECM) degradation. Administration of recombinant Sema3A protein hindered TAA progression and reduced TAAD incidence in mice. In summary, we demonstrated that Sema3A is a potential endogenous protective factor for TAA. Downregulation of Sema3A promotes TAA progression and TAAD attack, whereas upregulation of Sema3A or administration of recombinant Sema3A protein alleviates TAA and reduces TAAD incidence. The protection of Sema3A on TAA depends on the VSMC-EC crosstalk and activation of endothelial NRP1-ERK signaling, and thereby the suppression of angiogenesis and angiogenesis-associated inflammation and ECM degradation.

Retrograde menstruation is a widely recognized etiological factor for endometriosis (EMs); however, it is not the sole cause, as not all affected women develop EMs. Emerging evidence suggests a significant association between the vaginal microbiota and EMs. Nonetheless, the precise mechanisms by which microbial communities influence the pathophysiology and progression of EMs remain unclear. In this study, the cervical mucus from patients with EMs showed significantly greater microbial abundance compared with that of controls, with Streptococcus agalactiae (S. agalactiae) exhibiting the most substantial increase as determined by 16S rRNA gene sequencing. In a murine model, elevated S. agalactiae levels significantly increased the lesion number and colonization, whereas antibiotic treatment reduced lesion formation. Metabolomic analyses showed elevated L-carnitine levels in the cervical secretions and serum of patients with EMs, a finding corroborated in murine tissues. Exogenous L-carnitine administration similarly increased the number and weight of endometriotic lesions. Meanwhile, the inhibition of L-carnitine synthesis suppressed lesion formation induced by S. agalactiae. In vitro, both S. agalactiae and L-carnitine promoted EMs cell proliferation, migration, and invasion. L-carnitine synthesis inhibition attenuated cell motility stimulated by S. agalactiae. Mechanistically, S. agalactiae enhanced angiogenesis through L-carnitine by upregulating vascular endothelial growth factor expression and increasing human umbilical vein endothelial cell motility. These findings identify S. agalactiae as a key cervical microbiome component in EMs development and reveal a microbiota–metabolite–angiogenesis axis that may offer novel therapeutic targets.

Reconstruction of the microvascular network is essential for tissue regeneration and functional repair. However, inadequate vascularization remains an arduous challenge, hindering graft survival in wound healing and regenerative medicine. Although neovascularization and vascularized tissue engineering have received considerable attention, current investigations into the regulatory mechanisms of microvascular regeneration have primarily focused on intracellular signaling entities, leaving the extracellular molecular-level regulatory mechanisms unclear. Proteoglycans (PGs), ubiquitously distributed in the extracellular matrix and on cell membranes, consist of glycosaminoglycan (GAG) chains covalently linked to core proteins. Their spatiotemporal heterogeneity enables precise modulation of neovascularization; however, the structural complexity of PGs/GAGs obscures their mechanistic roles in vascular remodeling. This review systematically analyzes the regulatory roles of PGs/GAGs in the distinct phases of angiogenesis and vasculogenesis, which are two fundamental neovascularization processes. Additionally, we explored the emerging applications of PGs/GAGs in vascularized tissue engineering and regenerative medicine (VTERM), focusing on PG/GAG-functionalized biomaterials designed to mimic the native extracellular microenvironment and enhance specific signaling. This article critically evaluates the latest advances in optimizing these composite materials, and highlights the challenges associated with achieving spatiotemporal control over vascularization. By integrating profound molecular insights into innovative translational practices, this study establishes a theoretical framework for leveraging PGs/GAGs as multifunctional regulators in next-generation VTERM strategies.

GTP binding protein 3 (GTPBP3) is a highly conserved enzyme involved in tRNA modification, is essential for 5-taurinomethyluridine (τm⁵U) biosynthesis, and is linked to mitochondrial dysfunction within cells. However, the specific roles of GTPBP3 in different cell types during vascular development and angiogenesis are not well understood. In this study, we assess the physiological functions of GTPBP3 in endothelial cells (ECs) using two conditional knockout mouse models. GTPBP3 deletion, specifically in ECs, resulted in embryonic lethality owing to irregularities in angiogenesis and vascular formation. Tamoxifen-inducible EC-specific GTPBP3 knockout (Gtpbp3^iΔEC) mice show reduced retinal sprouting angiogenesis and impaired neovascularization after limb ischemia. Mechanistically, GTPBP3 absence in ECs leads to mitochondrial dysfunction and an increase in mitochondrial reactive oxygen species (mtROS), which alters Heme-regulated eIF2α kinase (HRI)—activating transcription factor 4 (ATF4)—Sestrin2 pathway expression, inhibiting activation of the mTORC1 pathway and angiogenesis. However, treatment with MitoQ—an mtROS scavenger—improves angiogenic dysfunction. These results highlight GTPBP3 as a vital element for developmental angiogenesis and neovascularization after limb ischemia.

Stroke is a leading cause of mortality and disability globally. Despite advancements in acute stroke therapies, patient outcomes with ischemic stroke remain suboptimal. Understanding its molecular mechanisms is crucial for developing effective treatments. Angiogenesis actively contributes to post-stroke functional recovery and improves long-term survival in stroke patients. Pericytes are essential for maintaining vascular stability and promoting angiogenesis. We hypothesized that microRNA-15a/16-1 in pericytes significantly modulates post-stroke angiogenesis and neurological recovery. Using a pericyte-specific miR-15a/16-1 conditional knockout (cKO) mouse model, we found that genetic deletion of miR-15a/16-1 in pericytes enhances angiogenesis, promotes cerebral blood flow recovery, and improves sensorimotor and cognitive outcomes following ischemic stroke. Mechanistically, RNA sequencing identified several novel targets of miR-15a/16-1, including Pappa2, Fgf9, Islr, and Ccr2. Interestingly, Pappa2, Fgf9, and Islr function as secreted proteins. Luciferase reporter assays demonstrated that miR-15a/16-1 directly binds and suppresses Pappa2, Fgf9, Islr, and Ccr2 activity in cultured pericytes. In vivo and in vitro assays further confirmed that miR-15a/16-1 silencing in pericytes significantly elevates the protein levels of Pappa2, Fgf9, Islr, and Ccr2 and enhances endothelial cell proliferation, migration, and tube formation under ischemic conditions. These findings suggest that targeting miR-15a/16-1 in pericytes offers a promising therapeutic strategy for enhancing stroke recovery by promoting neurovascular repair and reducing brain damage.

Extracellular vesicles (EVs) are phospholipid bilayer membrane structures secreted by cells and widely present in blood or body fluids, playing critical roles in cell communication and homeostasis. Increasing evidence has implicated EVs dysfunction in the pathogenesis of various cardiovascular diseases (CVD), including atherosclerosis (AS), ischemic heart disease, heart failure, aortic lesions, and valvular lesions. Using EVs derived from diseases or multiple tissue types to illuminate the functional mechanisms of EVs will promote pathological studies and drug development. EVs including exosomes, microvesicles, and apoptotic bodies, play key roles in the cellular physiological processes linked to AS, notably the recently developed engineering strategies applied to EVs have provided a new avenue for elucidating the mechanisms underlying the development and pathology of AS. To help researchers develop robust and reproducible methods that recapitulate in-vivo signatures of EVs to study AS development and pathology, this review summarized the current methods used to isolate or generate EVs and provided opinions on the use of EVs for disease and functional studies through collecting EVs derived from different kinds of cells or diseases in AS, which are the aspects that have not been generalized in previous reviews. In essence, EVs and their derivatives offer a novel approach to understanding the complex etiology of AS, and serve as a substantial basis for the discovery of potential diagnostic biomarkers and therapeutic targets.