Angiogenesis最新文献

Background

Ewing sarcoma (ES) is a rare but extremely aggressive bone and soft-tissue tumor. Clinical outcomes for patients with metastatic or recurrent ES remain poor, particularly for patients who are resistant to chemotherapy. This underscores an urgent need for alternative treatment strategies for these patients. A deep and comprehensive understanding of the cell–cell communications in ES may help identify new therapeutic approaches.

Methods

We first applied single-cell RNA sequencing (scRNA-seq) data analysis to map the cell–cell communication network within the ES tumor microenvironment (TME). Then, based on the cell–cell communication map, we inferred that multi-kinase anti-angiogenic inhibitors might effectively treat ES. Therefore, we investigated the anti-tumor efficacy of a novel multi-kinase inhibitor, KC1036, which primarily targets VEGFR2, MET, and AXL in ES cancer cell lines. The efficacy of KC1036 in ES was further validated in cell line-derived xenograft (CDX) models and a treatment-naïve patient-derived xenograft (PDX) model.

Results

We plotted a comprehensive cell–cell communication map of ES, where ES was characterized by highly immunosuppressive TME, strong autocrine signal NPY-NPY1R in tumor cells, wide activation of receptor kinase signaling pathways in cancer-associated fibroblasts (CAFs) (e.g., AXL, MET, FGFR, PDGFR, and KIT), and robust activation of tumor angiogenesis pathways (e.g., VEGFA/B-VEGFR1/2). Multi-kinase inhibitor KC1036 effectively inhibited ES tumor growth in both CDX and PDX models with superior efficacy compared to pazopanib, cabozantinib, and doxorubicin (DOX).

Conclusions

The novel anti-angiogenic inhibitor, KC1036, is effective in treating ES in the preclinical models.

Vascularization of implanted biomaterials is critical to reconstructive surgery and tissue engineering. Ultimately, the goal is to promote a rapidly perfusable hierarchical microvasculature that persists with time and can meet underlying tissue needs. We have previously shown that using a microsurgical technique, termed micropuncture (MP), in combination with porous granular hydrogel scaffolds (GHS) fabricated via interlinking hydrogel microparticles (microgels) results in a rapidly perfusable patterned microvasculature. However, whether this engineered microvasculature remains stable at longer time points remains unknown. Here, we combine MP with GHS and compare overall microvascular architecture and phenotype along with the evolving cellular landscape over a 28 day period. We demonstrate perfusable patterned microvascular stability in our MP + GHS model that occurs alongside a sustained rise in endothelial cell and macrophage recruitment. Specifically, MP yields a significant rise in M2 macrophages between the 7 and 28 day time points, suggesting ongoing microvascular remodeling, even in the presence of early pericyte stabilization. With time, the GHS microvasculature acquires a relatively equivalent arterial and venous morphology, as assessed through Ephrin-B2 and EphB4 quantification. Finally, angiography at 28 days shows that MP + GHS is associated with more perfusable microvascular loops when compared with MP + Bulk (nonporous) scaffolds. Hence, our surgically bioengineered microvasculature offers a unique opportunity to sustainably and precisely control biomaterial vascularization and ultimately advance the fields of reconstructive surgery and tissue engineering.

Limited vascularization and ischemia are major contributors to the chronicity of wounds, such as ulcers and traumatic injuries, which impose significant medical, social, and economic burdens. These challenges are particularly pronounced in patients with spinal cord injury (SCI), a disabling condition associated with vascular dysfunction, infections, and impaired peripheral circulation, complicating the treatment of pressure injuries (PIs) and the success of reconstructive procedures like grafts and flaps. Regenerative medicine aims to address these issues by identifying effective cellular therapies to restore vascular beds. Among these, cells from the stromal vascular fraction (SVF) of adipose tissue (AT) are promising due to their abundance of angiogenic and vasculogenic cells, including mesenchymal stem cells (MSCs) and endothelial colony-forming cells (ECFCs). This study evaluated the vasculogenic potential of AT-derived cellular fractions isolated via enzymatic digestion of white adipose tissue (WAT). We compared adipose-derived stem cells (ASCs) cultured from SVF with a combination of ECFCs and MSCs, expanded separately and transplanted in a 40:60 ratio. Results showed that while ASCs promote angiogenesis and vasculogenesis, the ECFC/MSC combination is superior, consistently forming perfused vascular beds in subcutaneous implants in nude mice. Furthermore, ECFCs and MSCs extracted from small amounts of WAT in SCI patients with PIs demonstrated similar functionality and vasculogenic potential to cells from healthy controls. These findings highlight the potential of AT-derived ECFCs and MSCs in autologous cell therapies, offering a promising avenue for advancing vascular regeneration in patients with SCI.

Objective

Adipose-derived regenerative cells (ADRCs) are promising cell sources for damaged tissue regeneration. The efficacy of therapeutic angiogenesis with ADRC implantation in patients with critical limb ischemia has been demonstrated in clinical studies. There are several possible mechanisms in this process such as cytokines and microRNA. Recently, cell-to-cell transfer of mitochondria gains more attention in regenerative medicine. However, the role of the mitochondrial transfer mechanism in ADRCs in the regeneration of functional tissue perfusion following ischemic injury remains unclear. In this study, we aimed to investigate whether mitochondrial transfer is a potential mechanism of therapeutic angiogenesis in ADRCs using a murine hindlimb ischemia model.

Methods and results

In initial studies, the occurrence of mitochondrial transfer of ADRC to endothelial cells and macrophages in a series of pro-angiogenic effects of ADRC was demonstrated in a mouse model of hindlimb ischemia. Subsequently, we comprehensively elucidated the modes of mitochondrial transfer from ADRCs to HUVECs and macrophages mediated by Connexin43-based gap junctions and tunneling nanotubes using time-lapse confocal microscopy and cell sorting techniques. Furthermore, mitochondrial transfer from ADRCs enhanced mitochondrial biogenesis and angiogenesis in vascular endothelial cells and shifted macrophages toward the M2-phenotype. Notably, partially canceled mitochondrial transfer from ADRCs could impede the angiogenic ability of ADRCs in hind limb ischemia.

Conclusions

ADRCs can protect against ischemic limbs, at least in part by mitochondrial transfer via gap junctions and tunneling of nanotubes into injured endothelial cells and macrophages. Additionally, mitochondrial transfer is a potential mechanism for therapeutic angiogenesis with ADRCs in hindlimb ischemia.

Graphical abstract

Schematic illustration showing potential mechanisms of mitochondrial transfer from ADRCs in mouse hindlimb ischemia model. This figure was created with BioRender.

Vascular permeability, crucial for organ function, relies on the endothelial barrier formed by intercellular junctions (AJs, TJs). However, mechanisms regulating these junctions and maintaining endothelial barrier integrity are incompletely understood. Here, we investigate the RNA-binding protein G3BP1’s role in endothelial barrier integrity using G3bp1 knockout mice and G3BP1-deficient human endothelial cells. We found that G3BP1 loss compromised barrier function, leading to reduced AJ and TJ protein levels and increased vascular permeability, particularly under LPS-induced inflammatory conditions. Mechanistically, G3BP1 exerts dual post-transcriptional control: it directly binds to and stabilizes mRNAs of key AJ proteins (VE-cadherin, p120), ensuring their sustained expression. Concurrently, G3BP1 binds MYD88 mRNA and promotes its decay, thereby suppressing the pro-permeability MYD88-ARNO-ARF6 signaling cascade, particularly during inflammation. Pharmacological or genetic inhibition of this pathway, or VE-cadherin overexpression, partially rescued barrier defects in G3BP1-deficient models, with combined interventions showing enhanced restoration under inflammatory conditions. Our findings reveal that G3BP1 maintains vascular barrier integrity through dual post-transcriptional control: stabilizing key AJ mRNA and suppressing inflammatory signaling via MYD88 mRNA decay. Targeting G3BP1 may offer a therapeutic strategy for vascular permeability disorders.

The Fontan procedure is a definitive surgical approach for complex cardiac malformations, redirecting systemic venous blood into the pulmonary circulation through a staged repair that separates systemic and pulmonary venous returns in the absence of a subpulmonary ventricle. The ensuing unique hemodynamic conditions compromise the endothelial function both in the pulmonary and the systemic circulation. The underlying pathophysiological mechanisms, although distinct within each vascular bed, are interrelated and may collectively contribute to progressive end-organ dysfunction, ultimately accounting for the significant morbidity burden in Fontan patients. This review provides an overview of the current knowledge on the pathophysiology of pulmonary and systemic vasculopathy in Fontan circulation, with particular emphasis on the interplay between endothelial dysfunction and adverse clinical outcomes. Remaining gaps in knowledge and directions of future research are also discussed.

Graphical abstract

Critical limb ischemia (CLI) is a refractory peripheral artery disease characterized by tissue ischemia, presenting significant therapeutic challenges. Current surgical revascularization treatments are limited by indications, complications, and other constraints, making the identification of novel therapeutic strategies an important objective for CLI management. In this study, we designed and synthesized a novel short peptide, named MY-1, and developed a GelMA/MY-1 hydrogel sustained-release system for local application in a mouse hindlimb ischemia model. This system significantly promoted blood flow reperfusion and muscle tissue repair in the ischemic region. In vitro experiments revealed that MY-1 promoted the formation of filopodia in endothelial cells, accelerating cell migration and confirming the critical role of CDC42 in this process. Importantly, we found that MY-1 regulates the stability of CDC42, driving endothelial cell dynamics. Building on this, we identified PSMD14 as a novel upstream target influencing CDC42 stability. Silencing PSMD14 impaired filopodia formation, migration ability, and CDC42 stability in endothelial cells, and MY-1 could not reverse these effects. This indicates the potential of MY-1 in regulating deubiquitinase activity in angiogenesis.

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.