Vascular Stem/Progenitor Cell Migration and Differentiation in Atherosclerosis

The Role of Progenitor Cells in the Pathogenesis of Arteriosclerosis

The increasing incidence of arteriosclerosis has become a significant global health burden. Arteriosclerosis is characterized by the thickening and hardening of arterial walls, which can lead to the narrowing or complete blockage of blood vessels. However, the pathogenesis of the disease remains incompletely understood. Recent research has shown that stem and progenitor cells found in the bone marrow and local vessel walls play a role in the development of arteriosclerosis by differentiating into various types of vascular cells, including endothelial cells, smooth muscle cells, fibroblasts, and inflammatory cells. This review aims to provide a comprehensive understanding of the role of stem and progenitor cells in the pathogenesis of arteriosclerosis, shedding light on the underlying mechanisms and potential therapeutic approaches for this disease.

Organelle adaptations in response to mechanical forces during tumour dissemination

Cell migration plays a pivotal role in various biological processes including cancer dissemination and successful metastasis, where the role of mechanical signals is increasingly acknowledged. This review focuses on the intricate mechanisms through which cancer cells modulate their migratory strategies via organelle adaptations in response to the extracellular matrix (ECM). Specifically, the nucleus and mitochondria emerge as pivotal mediators in this process. These organelles serve as sensors, translating mechanical stimuli into rapid metabolic alterations that sustain cell migration. Importantly, prolonged exposure to such stimuli can induce transcriptional or epigenetic changes, ultimately enhancing metastatic traits. Deciphering the intricate interplay between ECM properties and organelle adaptations not only advances our understanding of cytoskeletal dynamics but also holds promise for the development of innovative anti-metastatic therapeutic strategies.

Top Five Stories of the Cellular Landscape and Therapies of Atherosclerosis: Current Knowledge and Future Perspectives

Atherosclerosis (AS) is characterized by impairment and apoptosis of endothelial cells, continuous systemic and focal inflammation and dysfunction of vascular smooth muscle cells, which is documented as the traditional cellular paradigm. However, the mechanisms appear much more complicated than we thought since a bulk of studies on efferocytosis, transdifferentiation and novel cell death forms such as ferroptosis, pyroptosis, and extracellular trap were reported. Discovery of novel pathological cellular landscapes provides a large number of therapeutic targets. On the other side, the unsatisfactory therapeutic effects of current treatment with lipid-lowering drugs as the cornerstone also restricts the efforts to reduce global AS burden. Stem cell- or nanoparticle-based strategies spurred a lot of attention due to the attractive therapeutic effects and minimized adverse effects. Given the complexity of pathological changes of AS, attempts to develop an almighty medicine based on single mechanisms could be theoretically challenging. In this review, the top stories in the cellular landscapes during the initiation and progression of AS and the therapies were summarized in an integrated perspective to facilitate efforts to develop a multi-targets strategy and fill the gap between mechanism research and clinical translation. The future challenges and improvements were also discussed.

Promising Novel Therapies in the Treatment of Aortic and Visceral Aneurysms

Aortic and visceral aneurysms affect large arterial vessels, including the thoracic and abdominal aorta, as well as visceral arterial branches, such as the splenic, hepatic, and mesenteric arteries, respectively. Although these clinical entities have not been equally researched, it seems that they might share certain common pathophysiological changes and molecular mechanisms. The yet limited published data, with regard to newly designed, novel therapies, could serve as a nidus for the evaluation and potential implementation of such treatments in large artery aneurysms. In both animal models and clinical trials, various novel treatments have been employed in an attempt to not only reduce the complications of the already implemented modalities, through manufacturing of more durable materials, but also to regenerate or replace affected tissues themselves. Cellular populations like stem and differentiated vascular cell types, large diameter tissue-engineered vascular grafts (TEVGs), and various molecules and biological factors that might target aspects of the pathophysiological process, including cell-adhesion stabilizers, metalloproteinase inhibitors, and miRNAs, could potentially contribute significantly to the treatment of these types of aneurysms. In this narrative review, we sought to collect and present relevant evidence in the literature, in an effort to unveil promising biological therapies, possibly applicable to the treatment of aortic aneurysms, both thoracic and abdominal, as well as visceral aneurysms.

Effects of norepinephrine‑induced activation of rat vascular adventitial fibroblasts on proliferation and migration of BMSCs involved in vascular remodeling

Vascular remodeling caused by vascular injury such as hypertension and atherosclerosis is a complex process involving a variety of cells and factors, and the mechanism is unclear. A vascular injury model was simulated by adding norepinephrine (NE) to culture medium of vascular adventitial fibroblasts (AFs). NE induced activation and proliferation of AFs. To investigate the association between the AFs activation and bone marrow mesenchymal stem cells (BMSCs) differentiation in vascular remodeling. BMSCs were cultured with supernatant of the AFs culture medium. BMSC differentiation and migration were observed by immunostaining and Transwell assay, respectively, while cell proliferation was measured using the Cell Counting Kit-8. Expression levels of smooth muscle actin (α-SMA), TGF-β1 and SMAD3 were measured using western blot assay. The results indicated that compared with those in the control group, in which BMSCs were cultured in normal medium, expression levels of α-SMA, TGF-β1 and SMAD3 in BMSCs cultured in medium supplemented with supernatant of AFs, increased significantly (all P<0.05). Activated AFs induced the differentiation of BMSCs into vascular smooth muscle-like cells and promoted proliferation and migration. AFs activated by NE may induce BMSCs to participate in vascular remodeling. These findings may help design and develop new approaches and therapeutic strategies for vascular injury to prevent pathological remodeling.

The role of calcium-sensing receptor in ginsenoside Rg1 promoting reendothelialization to inhibit intimal hyperplasia after balloon injury

Calcium-sensing receptor (CaSR) is a G protein-coupled receptor, widely distributed in various tissues, including vascular endothelial cells and smooth muscle cells, which plays an important role in the migration and homing of stem/progenitor cells and the proliferation of tissue cells. Restenosis after Percutaneous coronary intervention (PCI) seriously affects its prognosis and application. Our previous research has found that ginsenoside Rg1 (GS-Rg1) can inhibit the occurrence of restenosis after balloon injury of the common carotid artery in rats, but the mechanism is still unclear. In this study, it was found that GS-Rg1 (4, 8, 16 mg/kg) inhibited vascular restenosis caused by balloon injury, and mobilize endothelial progenitor cells (EPCs) to promote reendothelialization and inhibit intimal hyperplasia, which significantly reduced after administration of CaSR antagonist NPS 2143. Interestingly, CaSR and its downstream JNK, P38 were highly expressed in the proliferative intima and participated in the abnormal proliferation of vascular smooth muscle cells mediated by smooth muscle progenitor cells (SMPCs). GS-Rg1 inhibited intimal hyperplasia, while it decreased the expression of CaSR, JNK, and P38. This might relate to the distribution of CaSR and the facilitation of GS-Rg1 on the vascular endothelial repair. It is concluded that CaSR plays a key role in GS-Rg1 promoting reendothelialization to inhibit intimal hyperplasia after balloon Injury.

Amarogentin inhibits vascular smooth muscle cell proliferation and migration and attenuates neointimal hyperplasia via AMPK activation

OBJECTIVES

Recent studies validated the expression of extraoral bitter taste receptors and established the importance of regulatory functions that are associated with various cellular biological processes of these receptors. However, the importance of bitter taste receptors' activity in neointimal hyperplasia has not yet been recognized. The bitter taste receptors activator amarogentin (AMA) is known to regulate a variety of cellular signals, including AMP-activated protein kinase (AMPK), STAT3, Akt, ERK, and p53, which are associated with neointimal hyperplasia.

MATERIALS AND METHODS

The present study assessed the effects of AMA on neointimal hyperplasia and explored the potential underlying mechanisms.

RESULTS

No cytotoxic concentration of AMA significantly inhibited the proliferation and migration of VSMCs induced by serum (15 % FBS) and PDGF-BB. In addition, AMA significantly inhibited neointimal hyperplasia of the cultured great saphenous vein in vitro and ligated mouse left carotid arteries in vivo, while the inhibitory effect of AMA on the proliferation and migration of VSMCs was mediated via the activation of AMPK-dependent signaling, which could be blocked via AMPK inhibition.

CONCLUSION

The present study revealed that AMA inhibited the proliferation and migration of VSMCs and attenuated neointimal hyperplasia, both in ligated mice carotid artery and cultured saphenous vein, which was mediated via a mechanism that involved AMPK activation. Importantly, the study highlighted the potential of AMA to be explored as a new drug candidate for neointimal hyperplasia.

Macrophages regulate vascular smooth muscle cell function during atherosclerosis progression through IL-1β/STAT3 signaling

Vascular smooth muscle cells (VSMCs) play a central role in atherosclerosis progression, but the functional changes in VSMCs and the associated cellular crosstalk during atherosclerosis progression remain unknown. Here we show that scRNA-seq analysis of proximal adjacent (PA) and atherosclerotic core (AC) regions of human carotid artery plaques identifies functional alterations in macrophage-like VSMCs, elucidating the main state differences between PA and AC VSMCs. And, IL-1β mediates macrophage-macrophage-like VSMC crosstalk through regulating key transcription factors involved in macrophage-like VSMCs functional alterations during atherosclerosis progression. In vitro assays reveal VSMCs trans-differentiated into a macrophage-like phenotype and then functional alterations in response to macrophage-derived stimuli. IL-1β promots the adhesion, inflammation, and apoptosis of macrophage-like VSMCs in a STAT3 dependent manner. The current findings provide interesting insight into the macrophages-macrophage-like VSMC crosstalk, which would drive functional alterations in the latter cell type through IL-1β/STAT3 axis during atherosclerosis progression.

How cell migration helps immune sentinels

The immune system relies on the migratory capacity of its cellular components, which must be mobile in order to defend the host from invading micro-organisms or malignant cells. This applies in particular to immune sentinels from the myeloid lineage, i.e. macrophages and dendritic cells. Cell migration is already at work during mammalian early development, when myeloid cell precursors migrate from the yolk sac, an extra embryonic structure, to colonize tissues and form the pool of tissue-resident macrophages. Later, this is accompanied by a migration wave of precursors and monocytes from the bone marrow to secondary lymphoid organs and the peripheral tissues. They differentiate into DCs and monocyte-derived macrophages. During adult life, cell migration endows immune cells with the ability to patrol their environment as well as to circulate between peripheral tissues and lymphoid organs. Hence migration of immune cells is key to building an efficient defense system for an organism. In this review, we will describe how cell migratory capacity regulates the various stages in the life of myeloid cells from development to tissue patrolling, and migration to lymph nodes. We will focus on the role of the actin cytoskeletal machinery and its regulators, and how it contributes to the establishment and function of the immune system.

Single Cell RNA Sequencing Reveals the Pathogenesis of Aortic Dissection Caused by Hypertension and Marfan Syndrome

Aortic dissection (AD) is mainly caused by hypertension and Marfan syndrome. However, it is unclear whether the cellular components and functions are different between the two causes. A total of 11 aortic samples were collected for single-cell RNA analysis and 20 clusters were disclosed, including VSMCs, fibroblasts, endothelial cells, T cells, B cells, monocytes, macrophages, mast cells, and neutrophils components. There were differences in cell subclusters and function between hypertension and Marfan patients. The cells also had different differentiations. Cellchat identified cell ligand–receptor interactions that were associated with hypertension and Marfan-induced AD involving SMC, fibroblast, mo-macrophages, and T-cell subsets. This study revealed the heterogeneity of cellular components and gene changes in hypertension and Marfan-induced AD. Through functional analysis and the changes in intercellular communication, the possible mechanisms of different causes of AD were explained from a new perspective, so we can better understand the occurrence and development of diseases.

A network pharmacology technique used to investigate the potential mechanism of Ligustilide's effect on atherosclerosis

Ligustilide (LIG) is a major active ingredient in traditional Chinese medicines that is also found in plant rhizomes such as carrot, coriander, and others, and it has been demonstrated to have cardiovascular preventive benefits. However, the mechanisms through which LIG protects the cardiovascular and cerebrovascular systems in atherosclerosis (AS) remain unknown. This study was aimed to investigate the mechanisms of LIG in AS utilizing the network pharmacology and molecular docking, and then to validate the putative mechanism through experiments. The network pharmacological analysis indicated that a total of 55 were performed on LIG and AS intersection targets. The genes of LIG and AS intersection targets enriched in the regulation of receptor and enzyme activity, cytokines-related, and transcription factors, indicating that these targets were primarily involved in cell proliferation and migration, regulating cell differentiation and skeletal activities in the development of AS. Finally, molecular docking was used to validate the major targets of LIG and AS intersection targets. Further experiments revealed that LIG may inhibit cell migration induced by AngII by reducing calcium influx, and regulating phenotypic translation-related proteins SM-22α and OPN. The present study investigated the potential targets and signaling pathways of LIG, which provides new insight into its anti-atherosclerosis actions in terms of reducing inflammation, cell proliferation, and migration, and may constitute a novel target for the treatment of AS. PRACTICAL APPLICATIONS: LIG has been shown to have cardiovascular protective benefits, the mechanism by which it protects the cardiovascular and cerebrovascular systems in AS remains unknown. This study uses a holistic network pharmacology strategy to investigate putative treatment pathways and conducts exploratory experimentation. The findings demonstrate that LIG reduces VSMC migration in the treatment of AS, acts as an anti-inflammatory agent, and prevents excessive cell proliferation and migration. Finally, the goal of our research is to uncover the molecular mechanism of LIG's influence on AS. The findings will provide a new research avenue for LIG as well as suggestions for the study of other herbal treatments. These research results will provide a new research direction for LIG and provide guidance for the research of other herbal medicines. This work revealed the multi-component, multi-target, multi-pathway, and multi-disease mechanism of LIG.

Circular gap forming device and two-dimensional area calculation for in vitro cell migration study

Cell wound healing assay is an important experimental technique for the detection of cell migration in vitro. At present, scratch on monolayer cells using a pipette tip is commonly used. However, it is difficult to guarantee the scratch with same width, and only the migration distance of a certain part is calculated. Therefore, the experimental method needs to be optimized. ATRA was used to treat hepa1-6 mouse hepatoma cells. Circular wound with diameter of 0.2 cm were formed by a circular gap forming device. The whole cell wound region could be captured under the microscope to observe cell migration. There are almost no crawling cells in the wound region. The migration capacity of hepa1-6 cells was evaluated by calculating the healing area. ATRA could significantly inhibit the migration of hepa1-6 cells. Compared with linear wound, the standard deviation of wound healing rate in the circular cell wound method is smaller. The circular cell wound method can ensure the dynamic observation of the same wound region, and calculate the healing area at the two-dimensional level with small error and high repetition rate. It is reliable and easy to operate, can be widely used in laboratory.

Ion channels in stem cells and their roles in stem cell biology and vascular diseases

Stem cell therapy may be a promising option for the treatment of vascular diseases. In recent years, significant progress has been made in stem cell research, especially in the mechanism of stem cell activation, homing and differentiation in vascular repair and reconstruction. Current research on stem cells focuses on protein expression and transcriptional networks. Ion channels are considered to be the basis for the generation of bioelectrical signals, which control the proliferation, differentiation and migration of various cell types. Although heterogeneity of multiple ion channels has been found in different types of stem cells, it is unclear whether the heterogeneous expression of ion channels is related to different cell subpopulations and/or different stages of the cell cycle. There is still a long way to go in clinical treatment by using the regulation of stem cell ion channels. In this review, we reviewed the main ion channels found on stem cells, their expression and function in stem cell proliferation, differentiation and migration, and the research status of stem cells' involvement in vascular diseases.

The amoeboid state as part of the epithelial-to-mesenchymal transition programme

Cell migration is essential for many biological processes, while abnormal cell migration is characteristic of cancer cells. Epithelial cells become motile by undergoing epithelial-to-mesenchymal transition (EMT), and mesenchymal cells increase migration speed by adopting amoeboid features. This review highlights how amoeboid behaviour is not merely a migration mode but rather a cellular state - within the EMT spectra - by which cancer cells survive, invade and colonise challenging microenvironments. Molecular biomarkers and physicochemical triggers associated with amoeboid behaviour are discussed, including an amoeboid associated tumour microenvironment. We reflect on how amoeboid characteristics support metastasis and how their liabilities could turn into therapeutic opportunities.

Phosphoinositide Signaling and Mechanotransduction in Cardiovascular Biology and Disease

Phosphoinositides, which are membrane-bound phospholipids, are critical signaling molecules located at the interface between the extracellular matrix, cell membrane, and cytoskeleton. Phosphoinositides are essential regulators of many biological and cellular processes, including but not limited to cell migration, proliferation, survival, and differentiation, as well as cytoskeletal rearrangements and actin dynamics. Over the years, a multitude of studies have uniquely implicated phosphoinositide signaling as being crucial in cardiovascular biology and a dominant force in the development of cardiovascular disease and its progression. Independently, the cellular transduction of mechanical forces or mechanotransduction in cardiovascular cells is widely accepted to be critical to their homeostasis and can drive aberrant cellular phenotypes and resultant cardiovascular disease. Given the versatility and diversity of phosphoinositide signaling in the cardiovascular system and the dominant regulation of cardiovascular cell functions by mechanotransduction, the molecular mechanistic overlap and extent to which these two major signaling modalities converge in cardiovascular cells remain unclear. In this review, we discuss and synthesize recent findings that rightfully connect phosphoinositide signaling to cellular mechanotransduction in the context of cardiovascular biology and disease, and we specifically focus on phosphatidylinositol-4,5-phosphate, phosphatidylinositol-4-phosphate 5-kinase, phosphatidylinositol-3,4,5-phosphate, and phosphatidylinositol 3-kinase. Throughout the review, we discuss how specific phosphoinositide subspecies have been shown to mediate biomechanically sensitive cytoskeletal remodeling in cardiovascular cells. Additionally, we discuss the direct interaction of phosphoinositides with mechanically sensitive membrane-bound ion channels in response to mechanical stimuli. Furthermore, we explore the role of phosphoinositide subspecies in association with critical downstream effectors of mechanical signaling in cardiovascular biology and disease.

Circulating Exosomal miRNAs as Novel Biomarkers for Stable Coronary Artery Disease

Exosomal miRNAs are currently being explored as a novel class of biomarkers in cardiovascular diseases. However, few reports have focused on the value of circulating exosomal miRNAs as biomarkers for stable coronary artery disease (SCAD). Here, we aimed to investigate whether miRNAs involved in cardiovascular diseases in circulating exosomes could serve as novel diagnostic biomarkers for SCAD. Firstly, the serum exosomes were isolated and purified by the ExoQuick reagent and identified by transmission electron microscopy, western blot, and nanoparticle tracking analysis. Then, the purified exosomes were quantified by measuring the exosome protein concentration and calculating the total protein amount. Next, eight miRNAs involved in cardiovascular diseases, miR-192-5p, miR-148b-3p, miR-125a-3p, miR-942-5p, miR-149-5p, miR-32-5p, miR-144-3p, and miR-142-5p, were quantified in circulating exosomes from the control group (n = 20) and the SCAD group (n = 20) by quantitative real-time polymerase chain reaction (qPCR). Finally, the gene targets of the differentially expressed miRNAs were predicted, and the functions and signaling pathways of these targets were analyzed using an online database. The isolated exosomes had a bilayer membrane with a diameter of about 100 nm and expressed exosomal markers including CD63, Tsg101, and Flotillin but negatively expressed Calnexin. Both the exosome protein concentration and total protein amount exhibited no significant differences between the two groups. The qPCR assay demonstrated that among the eight miRNAs, the expression levels of miR-942-5p, miR-149-5p, and miR-32-5p in the serum exosomes from the SCAD group were significantly higher than that from the control group. And the three miRNAs for SCAD diagnosis exhibited AUC values of 0.693, 0.702, and 0.691, respectively. GO categories and signaling pathways analysis showed that some of the predictive targets of these miRNAs were involved in the pathophysiology processes of SCAD. In conclusion, our findings suggest that serum exosomal miR-942-5p, miR-149-5p, and miR-32-5p may serve as potential diagnostic biomarkers for SCAD.

Evaluation of a high-throughput in vitro endothelial cell migration assay for the assessment of nicotine and tobacco delivery products

Endothelial cell migration is a critical process in the maintenance of healthy blood vessels. Impaired endothelial migration is reportedly associated with the development of cardiovascular diseases. Here, we report on the development of a 96-well in vitro endothelial migration assay for the purpose of comparative toxicological assessment of a novel THP relative to cigarette smoke, to be able to rapidly inform regulatory decision making. Uniform scratches were induced in confluent human umbilical vein endothelial cells using the 96-pin wound maker and exposed to 3R4F cigarette or THP aqueous extracts (AqE). Endothelial migration was recorded over 24 h, and the rate of wound closure calculated using mean relative wound density rather than migration rate as previously reported. This self-normalising parameter accounts for starting wound size, by comparing the density of the scratch to the outer region at each time-point. Furthermore, wound width acceptance criteria was defined to further increase the sensitivity of the assay. 3R4F and THP AqE samples were tested at comparable nicotine concentrations. 3R4F showed significant cytotoxicity and inhibition of wound healing whereas THP AqE did not show any response in either endpoint. This 96-well endothelial migration assay was suitably sensitive to distinguish combustible cigarette and THP test articles.

Stem/Progenitor Cells and Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a progressive disease characterized by endothelial dysfunction and vascular remodeling. Despite significant advancement in our understanding of the pathogenesis of PAH in recent years, treatment options for PAH are limited and their prognosis remains poor. PAH is now seen as a severe pulmonary arterial vasculopathy with structural changes driven by excessive vascular proliferation and inflammation. Perturbations of a number of cellular and molecular mechanisms have been described, including pathways involving growth factors, cytokines, metabolic signaling, elastases, and proteases, underscoring the complexity of the disease pathogenesis. Interestingly, emerging evidence suggests that stem/progenitor cells may have an impact on disease development and therapy. In preclinical studies, stem/progenitor cells displayed an ability to promote endothelial repair of dysfunctional arteries and induce neovascularization. The stem cell-based therapy for PAH are now under active investigation. This review article will briefly summarize the updates in the research field, with a special focus on the contribution of stem/progenitor cells to lesion formation via influencing vascular cell functions and highlight the potential clinical application of stem/progenitor cell therapy to PAH.

Fibroblasts in atherosclerosis: heterogeneous and plastic participants

PURPOSE OF REVIEW

Fibroblasts are very heterogeneous and plastic cells in the vasculature. A growing interest in fibroblasts in healthy and atherosclerotic vasculature is observed, next to macrophages, endothelial cells, and smooth muscle cells (SMCs). In this review, we discuss fibroblast presence, heterogeneity, origin, and plasticity in health and atherosclerosis based on latest literature.

RECENT FINDINGS

With help of single cell sequencing (SCS) techniques, we have gained more insight into presence and functions of fibroblasts in atherosclerosis. Next to SMCs, fibroblasts are extracellular matrix-producing cells abundant in the vasculature and involved in atherogenesis. Fibroblasts encompass a heterogeneous population and SCS data reveal several fibroblast clusters in healthy and atherosclerotic tissue with varying gene expression and function. Moreover, recent findings indicate interesting similarities between adventitial stem and/or progenitor cells and fibroblasts. Also, communication with inflammatory cells opens up a new therapeutic avenue.

SUMMARY

Because of their highly plastic and heterogeneous nature, modulating fibroblast cell function and communication in the atherosclerotic vessel might be useful in battling atherosclerosis from within the plaque.

Development of mucoadhesive cationic polypeptide micelles for sustained cabozantinib release and inhibition of corneal neovascularization

Corneal neovascularization (CNV) is one of the leading risk factors for vision loss. Anti-angiogenic drugs can theoretically be extended to the treatment of CNV. However, the application of these drugs is often hindered by traditional administration methods, e.g., eye drops, which is ascribed to the unique structure of the cornea and tear film. In this study, cationic polypeptide nanoparticles with mucoadhesive ability that carry lipophilic cabozantinib (a tyrosine kinase inhibitor), called Cabo-NPs, were developed for sustained cabozantinib release and inhibition of CNV. The polypeptides were synthesized via N-carboxyanhydride ring-opening polymerization and could self-assemble into micelles with cabozantinib in aqueous solution. The Cabo-NPs possessed good biocompatibility both in corneal epithelial cells and mouse corneas. More importantly, in vitro angiogenesis assays demonstrated the strong inhibitory effect of Cabo-NPs on cell migration and tube formation. Furthermore, the Cabo-NPs exerted superior anti-angiogenic effects with remarkable reductions in the neovascular area, which were as effective as the clinical dexamethasone but without apparent side effects. The therapeutic mechanism of the Cabo-NPs is closely related to the significant decrease in proangiogenic and proinflammatory factors, suppressing neovascularization and inflammation. Overall, cationic Cabo-NPs offer a new prospect for safe and effective CNV treatment via enhancing the bioavailability of lipophilic cabozantinib.

Role of Endothelial Dysfunction in Cardiovascular Diseases: The Link Between Inflammation and Hydrogen Sulfide

Endothelial cells are important constituents of blood vessels that play critical roles in cardiovascular homeostasis by regulating blood fluidity and fibrinolysis, vascular tone, angiogenesis, monocyte/leukocyte adhesion, and platelet aggregation. The normal vascular endothelium is taken as a gatekeeper of cardiovascular health, whereas abnormality of vascular endothelium is a major contributor to a plethora of cardiovascular ailments, such as atherosclerosis, aging, hypertension, obesity, and diabetes. Endothelial dysfunction is characterized by imbalanced vasodilation and vasoconstriction, elevated reactive oxygen species (ROS), and proinflammatory factors, as well as deficiency of nitric oxide (NO) bioavailability. The occurrence of endothelial dysfunction disrupts the endothelial barrier permeability that is a part of inflammatory response in the development of cardiovascular diseases. As such, abrogation of endothelial cell activation/inflammation is of clinical relevance. Recently, hydrogen sulfide (H₂S), an entry as a gasotransmitter, exerts diverse biological effects through acting on various targeted signaling pathways. Within the cardiovascular system, the formation of H₂S is detected in smooth muscle cells, vascular endothelial cells, and cardiomyocytes. Disrupted H₂S bioavailability is postulated to be a new indicator for endothelial cell inflammation and its associated endothelial dysfunction. In this review, we will summarize recent advances about the roles of H₂S in endothelial cell homeostasis, especially under pathological conditions, and discuss its putative therapeutic applications in endothelial inflammation-associated cardiovascular disorders.

Adventitial Cell Atlas of wt (Wild Type) and ApoE (Apolipoprotein E)-Deficient Mice Defined by Single-Cell RNA Sequencing

Objective- Vascular adventitia encompasses progenitors and is getting recognized as the major site of inflammation in early stage of atherosclerosis. However, the cellular atlas of the heterogeneous adventitial cells, the intercellular communication, the cellular response of adventitia to hyperlipidemia, and its contribution to atherosclerosis have been elusive. Approach and Results- Single-cell RNA sequencing was applied to wt (wild type) and ApoE (apolipoprotein E)-deficient aortic adventitia from 12-week-old C57BL/6J mice fed on normal laboratory diet with early stage of atherosclerosis. Unbiased clustering analysis revealed that the landscape of adventitial cells encompassed adventitial mesenchyme cells, immune cells (macrophages, T cells, and B cells), and some types of rare cells, for example, neuron, lymphatic endothelial cells, and innate lymphoid cells. Seurat clustering analysis singled out 6 nonimmune clusters with distinct transcriptomic profiles, in which there predominantly were stem/progenitor cell-like and proinflammatory population (Mesen II). In ApoE-deficient adventitia, resident macrophages were activated and related to increased myeloid cell infiltration in the adventitia. Cell communication analysis further elucidated enhanced interaction between a mesenchyme cluster and inflammatory macrophages in ApoE-deficient adventitia. In vitro transwell assay confirmed the proinflammatory role of SCA1+ (stem cell antigen 1 positive) Mesen II population with increased CCL2 (chemokine [C-C motif] ligand 2) secretion and thus increased capacity to attract immune cells in ApoE-deficient adventitia. Conclusions- Cell atlas defined by single-cell RNA sequencing depicted the heterogeneous cellular landscape of the adventitia and uncovered several types of cell populations. Furthermore, resident cell interaction with immune cells appears crucial at the early stage of atherosclerosis.

Vascular progenitor cell senescence in patients with Marfan syndrome

Vascular progenitor cells (VPCs) present in the adventitia of the vessel wall play a critical role in the regulation of vascular repair following injury. This study aimed to assess the function of VPCs isolated from patients with Marfan syndrome (MFS). VPCs were isolated from control and MFS donors and characterized. Compared with control‐VPCs, MFS‐VPCs exhibited cellular senescence as demonstrated by increased cell size, higher SA‐β‐gal activity and elevated levels of p53 and p21. RNA sequencing showed that several cellular process‐related pathways including cell cycle and cellular senescence were significantly enriched in MFP‐VPCs. Notably, the expression level of TGF‐β1 was much higher in MFS‐VPCs than control‐VPCs. Treatment of control‐VPCs with TGF‐β1 significantly enhanced mitochondrial reactive oxidative species (ROS) and induced cellular senescence whereas inhibition of ROS reversed these effects. MFS‐VPCs displayed increased mitochondrial fusion and decreased mitochondrial fission. Treatment of control‐VPCs with TGF‐β1 increased mitochondrial fusion and reduced mitochondrial fission. Nonetheless, treatment of mitofusin2 (Mfn2)‐siRNA inhibited TGF‐β1‐induced mitochondrial fusion and cellular senescence. Furthermore, TGF‐β1‐induced mitochondrial fusion was mediated by the AMPK signalling pathway. Our study shows that TGF‐β1 induces VPC senescence in patients with MFS by mediating mitochondrial dynamics via the AMPK signalling pathway.

The Impact of Natural Antioxidants on the Regenerative Potential of Vascular Cells

With advances in technology, the impact of natural antioxidants on vascular cell regeneration is attracting enormous attention as many current studies are now exploring the clinical potential of antioxidants in regenerative medicine. Natural antioxidants are an important step for improving future treatment and prevention of various diseases such as cardiovascular, cancer, neurodegenerative, and diabetes. The use of natural antioxidants which have effects on several types of stem cells with the potential to differentiate into functional endothelium and smooth muscle cells (known as vascular progenitors) for vascular regeneration might override pharmaceutical and surgical treatments. The natural antioxidant systems comprise of several components present in fruits, vegetables, legumes, medicinal plants, and other animal-derived products that interact with reactive free radicals such as oxygen and nitrogen species to neutralize their oxidative damaging effects on vascular cells. Neutralization by antioxidants involves the breaking down of the oxidative cascade chain reactions in the cell membranes in order to fine-tune the free radical levels. The effect of natural antioxidants on vascular regeneration includes restoration or establishment of new vascular structures and functions. In this review, we highlight the significant effects of natural antioxidants on modulating vascular cells to regenerate vessels, as well as possible mechanisms of action and the potential therapeutic benefits on health. The role of antioxidants in regenerating vessels may be critical for the future of regenerative medicine in terms of the maintenance of the normal functioning of vessels and the prevention of multiple vascular diseases.

Atherosclerosis is a vascular stem cell disease caused by insulin

The present article proposes the hypothesis that when multipotent vascular stem cells are exposed to excessive insulin in a rhythmic pattern of sharply rising and falling concentrations, their differentiation is misdirected toward adipogenic and osteogenic cell lineages. This results in plaque-like accumulation of adipocytes with fat and cholesterol deposition from adipocyte debris, and osteogenic (progenitor) cells with a calcified matrix in advanced lesions. The ingrowth of capillaries and infiltration with macrophages, which upon uptake of lipids turn into foam cells, are unspecific pro-resolving reactions. Epidemiological, histopathological, pharmacological, and experimental evidence in favour of this hypothesis is summarised.

Role of Resident Stem Cells in Vessel Formation and Arteriosclerosis

Vascular, resident stem cells are present in all 3 layers of the vessel wall; they play a role in vascular formation under physiological conditions and in remodeling in pathological situations. Throughout development and adult early life, resident stem cells participate in vessel formation through vasculogenesis and angiogenesis. In adults, the vascular stem cells are mostly quiescent in their niches but can be activated in response to injury and participate in endothelial repair and smooth muscle cell accumulation to form neointima. However, delineation of the characteristics and of the migration and differentiation behaviors of these stem cells is an area of ongoing investigation. A set of genetic mouse models for cell lineage tracing has been developed to specifically address the nature of these cells and both migration and differentiation processes during physiological angiogenesis and in vascular diseases. This review summarizes the current knowledge on resident stem cells, which has become more defined and refined in vascular biology research, thus contributing to the development of new potential therapeutic strategies to promote endothelial regeneration and ameliorate vascular disease development.

Vascular Calcification: Is it rather a Stem/Progenitor Cells Driven Phenomenon?

Vascular calcification (VC) has witnessed a surge of interest. Vasculature is virtually an omnipresent organ and has a notably high capacity for repair throughout embryonic and adult life. Of the vascular diseases, atherosclerosis is a leading cause of morbidity and mortality on account of ectopic cartilage and bone formation. Despite the identification of a number of risk factors, all the current theories explaining pathogenesis of VC in atherosclerosis are far from complete. The most widely accepted response to injury theory and smooth muscle transdifferentiation to explain the VC observed in atherosclerosis is being challenged. Recent focus on circulating and resident progenitor cells in the vasculature and their role in atherogenesis and VC has been the driving force behind this review. This review discusses intrinsic cellular players contributing to fate determination of cells and tissues to form ectopic cartilage and bone formation.

Endothelial nitric oxide synthase overexpressing human early outgrowth cells inhibit coronary artery smooth muscle cell migration through paracrine functions

Cells mobilized from the bone marrow can contribute to endothelial regeneration and repair. Nevertheless, cardiovascular diseases are associated with diminished numbers and function of these cells, attenuating their healing potential. Gene transfer of endothelial nitric oxide synthase (eNOS) can restore the activity of circulating cells. Furthermore, estrogen accelerates the reendothelialization capacity of early outgrowth cells (EOCs). We hypothesized that overexpressing eNOS alone or in combination with estrogen stimulation in EOCs would potentiate the beneficial effects of these cells in regulating smooth muscle cell (SMC) function. Native human EOCs did not have any effect on human coronary artery SMC (hCASMC) proliferation or migration. Transfecting EOCs with a human eNOS plasmid and/or stimulating with 17β-estradiol (E₂) increased NO production 3-fold and enhanced EOC survival. Moreover, in co-culture studies, eNOS overexpressing or E2-stimulated EOCs reduced hCASMC migration (by 23% and 56% respectively), vs. control EOCs. These effects do not implicate ERK1/2 or focal adhesion kinases. Nevertheless, NOS-EOCs had no effect on hCASMC proliferation. These results suggest that overexpressing or activating eNOS in EOCs increases their survival and enhances their capacity to regulate SMC migration through paracrine effects. These data elucidate how eNOS overexpression or activation in EOCs can prevent vascular remodeling.