Enhanced pericyte-endothelial interactions through NO-boosted extracellular vesicles drive revascularization in a mouse model of ischemic injury

Netrin1-Enriched Exosomes From Genetically Modified ADSCs as a Novel Treatment for Diabetic Limb Ischemia

Diabetic limb ischemia (DLI) is a frequent complication of diabetes and the leading cause of non-traumatic amputation. Traditional treatments like stent placement and bypass surgery may not suit all patients. Exosome transplantation has emerged as a promising therapy. Netrin1, a protective cardiovascular factor, has an unclear role in DLI. This study investigates the role of Netrin1 in DLI patients and evaluates the therapeutic potential of exosomes derived from Netrin1-overexpressing adipose-derived stem cells (N-ADSCs). The expression of Netrin1 is significantly decreased in both endothelial cells and serum of DLI patients, highlighting its potential as a biomarker or therapeutic target. In vitro, Netrin1-enriched exosomes (N-Exos) promoted human umbilical vein endothelial cell (HUVEC) proliferation, migration, tube formation, and increased resistance to apoptosis under high glucose conditions. These protective effects are mediated through PI3K/AKT/eNOS and MEK/ERK pathways, and N-Exos further facilitated macrophage polarization from M1 to M2. In vivo, N-Exos demonstrates superior therapeutic effects over ADSC exosomes (Exos), including enhanced angiogenesis, improved collateral artery remodeling, reduced inflammation, and muscle protection. Collectively, these findings identify Netrin1 as a critical factor in DLI and underscore its significance in disease progression and therapeutic strategies. N-Exos offers a promising non-cellular therapeutic approach for the treatment of DLI.

Mitochondria Transplantation to Bone Marrow Stromal Cells Promotes Angiogenesis During Bone Repair

Angiogenesis is crucial for successful bone defect repair. Co-transplanting Bone Marrow Stromal Cells (BMSCs) and Endothelial Cells (ECs) has shown promise for vascular augmentation, but it face challenges in hostile tissue microenvironments, including poor cell survival and limited efficacy. In this study, the mitochondria of human BMSCs are isolated and transplanted to BMSCs from the same batch and passage number (BMSCsmito). The transplanted mitochondria significantly boosted the ability of BMSCsmito-ECs to promote angiogenesis, as assessed by in vitro tube formation and spheroid sprouting assays, as well as in vivo transplantation experiments in balb/c mouse and SD rat models. The Dll4-Notch1 signaling pathway is found to play a key role in BMSCsmito-induced endothelial tube formation. Co-transplanting BMSCsmito with ECs in a rat cranial bone defect significantly improves functional vascular network formation, and improve bone repair outcomes. These findings thus highlight that mitochondrial transplantation, by acting through the DLL4-Notch1 signaling pathway, represents a promising therapeutic strategy for enhancing angiogenesis and improving bone repair. Hence, mitochondrial transplantation to BMSCS as a therapeutic approach for promoting angiogenesis offers valuable insights and holds much promise for innovative regenerative medicine therapies.

Insights into the mechanisms of angiogenesis in infantile hemangioma

Infantile hemangioma (IH) is the most common benign tumor in infants and usually resolves on its own. However, a small portion of IH cases are accompanied by serious complications and other problems, impacting the physical and psychological health of the children affected. The pathogenesis of IH is highly controversial. Studies have shown that abnormal blood vessel formation is an important pathological basis for the development of IH. Compared with that in normal tissues, the equilibrium of blood vessel growth at the tumor site is disrupted, and interactions among other types of cells, such as immune cells, promote the rapid proliferation and migration of vascular tissue cells and the construction of vascular networks. Currently, propranolol is the most common systemic drug used to inhibit the growth of IHs and accelerate their regression. The purpose of this review is to provide the latest research on the mechanisms of angiogenesis in IH. We discuss the possible roles of three major factors, namely, estrogen, hypoxia, and inflammation, in the development of IH. Additionally, we summarize the key roles of tumor cell subpopulations, such as pericytes, in the proliferation and regression of IH considering evidence from the past few years, with an emphasis on the possible mechanisms of propranolol in the treatment of IH. Angiogenesis is an important event during the development of IH, and an in-depth understanding of the molecular mechanisms of angiogenesis will provide new insights into the biology and clinical treatment of IH.

Blood-brain barrier disruption: a culprit of cognitive decline?

Cognitive decline covers a broad spectrum of disorders, not only resulting from brain diseases but also from systemic diseases, which seriously influence the quality of life and life expectancy of patients. As a highly selective anatomical and functional interface between the brain and systemic circulation, the blood-brain barrier (BBB) plays a pivotal role in maintaining brain homeostasis and normal function. The pathogenesis underlying cognitive decline may vary, nevertheless, accumulating evidences support the role of BBB disruption as the most prevalent contributing factor. This may mainly be attributed to inflammation, metabolic dysfunction, cell senescence, oxidative/nitrosative stress and excitotoxicity. However, direct evidence showing that BBB disruption causes cognitive decline is scarce, and interestingly, manipulation of the BBB opening alone may exert beneficial or detrimental neurological effects. A broad overview of the present literature shows a close relationship between BBB disruption and cognitive decline, the risk factors of BBB disruption, as well as the cellular and molecular mechanisms underlying BBB disruption. Additionally, we discussed the possible causes leading to cognitive decline by BBB disruption and potential therapeutic strategies to prevent BBB disruption or enhance BBB repair. This review aims to foster more investigations on early diagnosis, effective therapeutics, and rapid restoration against BBB disruption, which would yield better cognitive outcomes in patients with dysregulated BBB function, although their causative relationship has not yet been completely established.

Overcoming big bottlenecks in vascular regeneration

Bioengineering and regenerative medicine strategies are promising for the treatment of vascular diseases. However, current limitations inhibit the ability of these approaches to be translated to clinical practice. Here we summarize some of the big bottlenecks that inhibit vascular regeneration in the disease applications of aortic aneurysms, stroke, and peripheral artery disease. We also describe the bottlenecks preventing three-dimensional bioprinting of vascular networks for tissue engineering applications. Finally, we describe emerging technologies and opportunities to overcome these challenges to advance vascular regeneration.

Emerging Epigenetic Targets and Their Molecular Impact on Vascular Remodeling in Pulmonary Hypertension

Pulmonary Hypertension (PH) is a terminal disease characterized by severe pulmonary vascular remodeling. Unfortunately, targeted therapy to prevent disease progression is limited. Here, the vascular cell populations that contribute to the molecular and morphological changes of PH in conjunction with current animal models for studying vascular remodeling in PH will be examined. The status quo of epigenetic targeting for treating vascular remodeling in different PH subtypes will be dissected, while parallel epigenetic threads between pulmonary hypertension and pathogenic cancer provide insight into future therapeutic PH opportunities.