Vascular Smooth Muscle Cells Contribute to Atherosclerosis Immunity

Corrugated intimal surface of the ovine aorta: when physiology resembles pathology

The aortic lumen in healthy animals is characterized by a smooth, whitish surface, but sheep have macroscopic corrugation of the intimal surface in the thoracic aorta (TA). Our aim was to determine if this finding was pathological or physiological. Thirteen sheep aortas were included in this work together with aortas from cattle (n = 3), a goat (n = 1), horses (n = 4), dogs (n = 2), rabbits (n = 2) and a pig (n = 1). A corrugated intimal surface in the TA was seen in all the sheep and the goat but was less evident in the cattle. Histologically, in sheep the TA intimal surface was seen to have multifocal bulging areas that protruded into the lumen. The outer half of the tunica media had numerous, randomly distributed muscle islands that disrupted the arrangement of the elastic lamella, displacing them towards the lumen. We conclude that the intimal corrugation of the TA in sheep is physiological and must not be misinterpreted as pathological.

Role of CaMKII in diabetes induced vascular injury and its interaction with anti-diabetes therapy

Diabetes mellitus is a metabolic disorder denoted by chronic hyperglycemia that drives maladaptive structural changes and functional damage to the vasculature. Attenuation of this pathological remodeling of blood vessels remains an unmet target owing to paucity of information on the metabolic signatures of this process. Ca2+/calmodulin-dependent kinase II (CaMKII) is expressed in the vasculature and is implicated in the control of blood vessels homeostasis. Recently, CaMKII has attracted a special attention in view of its chronic upregulated activity in diabetic tissues, yet its role in the diabetic vasculature remains under investigation.This review highlights the physiological and pathological actions of CaMKII in the diabetic vasculature, with focus on the control of the dialogue between endothelial (EC) and vascular smooth muscle cells (VSMC). Activation of CaMKII enhances EC and VSMC proliferation and migration, and increases the production of extracellular matrix which leads to maladaptive remodeling of vessels. This is manifested by activation of genes/proteins implicated in the control of the cell cycle, cytoskeleton organization, proliferation, migration, and inflammation. Endothelial dysfunction is paralleled by impaired nitric oxide signaling, which is also influenced by CaMKII signaling (activation/oxidation). The efficiency of CaMKII inhibitors is currently being tested in animal models, with a focus on the genetic pathways involved in the regulation of CaMKII expression (microRNAs and single nucleotide polymorphisms). Interestingly, studies highlight an interaction between the anti-diabetic drugs and CaMKII expression/activity which requires further investigation. Together, the studies reviewed herein may guide pharmacological approaches to improve health-related outcomes in patients with diabetes.

Light deficiency in Apoe-/-mice increases atheroma plaque size and vulnerability by modulating local immunity

Previous research suggests a potential involvement of the cytokine LIGHT (TNFSF14) in atherosclerosis. In this study, the genetic inactivation of Light in Apolipoprotein E deficient mice (male and female C57BL) augmented plaque size and vulnerability while decreasing Treg cells. Human and mouse transcriptomic results demonstrated deranged immune pathways in human atheromas with low LIGHT expression levels and in Light-deficient murine atheromas. In agreement with this, in vitro LIGHT-treatment of human lymphocytes, induced an elevation of Treg cell prevalence while proteomic analysis showed a downregulation of apoptotic and leukocyte cytotoxic pathways. Consistently, Light-deficient mouse lesions displayed increased plaque apoptosis and detrimental adventitial T-lymphocyte aggregates. Altogether suggested that LIGHT could promote a Treg prevalence in the local immunity to prevent the generation of vulnerable plaques via decreased cytotoxic microenvironment and apoptosis. Light gene delivery in Apoe-/-Light-/- mice, through bone marrow transplantation approaches, consistently diminished lesion size and restored local plaque immunity. Altogether demonstrate that Light-deficiency promotes atheroma plaque progression, at least in part through local loss of immune homeostasis and increased apoptosis. This study suggest that therapies based on the local delivery of LIGHT within plaques might therefore prevent immune cell derangement and advanced atherosclerosis.

Circ-ABCA1 promotes oxidized low-density lipoprotein-induced inflammation and phenotypic switch in vascular smooth muscle cells

OBJECTIVE

Atherosclerosis (AS) is a chronic inflammatory disease of the arterial wall, in which Human Vascular Smooth Muscle Cells (HVSMCs) are involved. Nevertheless, the functions and mechanisms of circRNAs in oxidized Low-Density Lipoprotein (ox-LDL)-induced vascular smooth muscle cells remain unclear.

METHODS

Circ-ABCA1 expression was measured in the models of AS. Then, in the vitro model, oligonucleotide transfection was performed, followed by an analysis of VSMC proliferation, migration, inflammation, and phenotypic switch. Also, in the in vivo model, mice were injected with shRNA lentivirus, followed by histological examination of aortic tissues. Finally, the interaction of circ-ABCA1, miR-885-5p, and ROCK2 was identified.

RESULTS

Circ-ABCA1, was confirmed to be overexpressed in ox-LDL-induced VSMCs and mouse models of AS. Functionally, silencing circ-ABCA1 via oligonucleotide transfection suppressed VSMC proliferation, migration, inflammation, and phenotypic switch in vitro and prevented AS development in mice in vivo. Mechanistically, circ-ABCA1 absorbed miR-885-5p, which targeted ROCK2.

CONCLUSION

Taken together, the data from this study suggest that circ-ABCA1 mediates cellular inflammation and phenotype switching through the miR-885-5p/ROCK2 axis in ox-LDL-induced VSMCs, and the circ-ABCA1/miR-885-5p/ROCK2 axis is a new potential biomarker for the treatment of AS.

Cholesteryl Hemiazelate Present in Cardiovascular Disease Patients Causes Lysosome Dysfunction in Murine Fibroblasts

There is growing evidence supporting the role of fibroblasts in all stages of atherosclerosis, from the initial phase to fibrous cap and plaque formation. In the arterial wall, as with macrophages and vascular smooth muscle cells, fibroblasts are exposed to a myriad of LDL lipids, including the lipid species formed during the oxidation of their polyunsaturated fatty acids of cholesteryl esters (PUFA-CEs). Recently, our group identified the final oxidation products of the PUFA-CEs, cholesteryl hemiesters (ChE), in tissues from cardiovascular disease patients. Cholesteryl hemiazelate (ChA), the most prevalent lipid of this family, is sufficient to impact lysosome function in macrophages and vascular smooth muscle cells, with consequences for their homeostasis. Here, we show that the lysosomal compartment of ChA-treated fibroblasts also becomes dysfunctional. Indeed, fibroblasts exposed to ChA exhibited a perinuclear accumulation of enlarged lysosomes full of neutral lipids. However, this outcome did not trigger de novo lysosome biogenesis, and only the lysosomal transcription factor E3 (TFE3) was slightly transcriptionally upregulated. As a consequence, autophagy was inhibited, probably via mTORC1 activation, culminating in fibroblasts' apoptosis. Our findings suggest that the impairment of lysosome function and autophagy and the induction of apoptosis in fibroblasts may represent an additional mechanism by which ChA can contribute to the progression of atherosclerosis.

Nanopore long-read RNA sequencing reveals functional alternative splicing variants in human vascular smooth muscle cells

Vascular smooth muscle cells (VSMCs) are the major contributor to vascular repair and remodeling, which showed high level of phenotypic plasticity. Abnormalities in VSMC plasticity can lead to multiple cardiovascular diseases, wherein alternative splicing plays important roles. However, alternative splicing variants in VSMC plasticity are not fully understood. Here we systematically characterized the long-read transcriptome and their dysregulation in  human aortic smooth muscle cells (HASMCs) by employing the Oxford Nanopore Technologies long-read RNA sequencing in HASMCs that are separately treated with platelet-derived growth factor, transforming growth factor, and hsa-miR-221-3P transfection. Our analysis reveals frequent alternative splicing events and thousands of unannotated transcripts generated from alternative splicing. HASMCs treated with different factors exhibit distinct transcriptional reprogramming modulated by alternative splicing. We also found that unannotated transcripts produce different open reading frames compared to the annotated transcripts. Finally, we experimentally validated the unannotated transcript derived from gene CISD1, namely CISD1-u, which plays a role in the phenotypic switch of HASMCs. Our study characterizes the phenotypic modulation of HASMCs from an insight of long-read transcriptome, which would promote the understanding and the manipulation of HASMC plasticity in cardiovascular diseases.

Extracellular vesicles in atherosclerosis and vascular calcification: the versatile non-coding RNAs from endothelial cells and vascular smooth muscle cells

Atherosclerosis (AS) is characterized by the accumulation of lipids, fibrous elements, and calcification in the innermost layers of arteries. Vascular calcification (VC), the deposition of calcium and phosphate within the arterial wall, is an important characteristic of AS natural history. However, medial arterial calcification (MAC) differs from intimal calcification and cannot simply be explained as the consequence of AS. Endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) are directly involved in AS and VC processes. Understanding the communication between ECs and VSMCs is critical in revealing mechanisms underlying AS and VC. Extracellular vesicles (EVs) are found as intercellular messengers in kinds of physiological processes and pathological progression. Non-coding RNAs (ncRNAs) encapsulated in EVs are involved in AS and VC, including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs). The effects of ncRNAs have not been comprehensively understood, especially encapsulated in EVs. Some ncRNAs have demonstrated significant roles in AS and VC, but it remains unclear the functions of the majority ncRNAs detected in EVs. In this review, we summarize ncRNAs encapsulated in EC-EVs and VSMC-EVs, and the signaling pathways that are involved in AS and VC.

Cardiovascular Brain Circuits

The cardiovascular system is hardwired to the brain via multilayered afferent and efferent polysynaptic axonal connections. Two major anatomically and functionally distinct though closely interacting subcircuits within the cardiovascular system have recently been defined: The artery-brain circuit and the heart-brain circuit. However, how the nervous system impacts cardiovascular disease progression remains poorly understood. Here, we review recent findings on the anatomy, structures, and inner workings of the lesser-known artery-brain circuit and the better-established heart-brain circuit. We explore the evidence that signals from arteries or the heart form a systemic and finely tuned cardiovascular brain circuit: afferent inputs originating in the arterial tree or the heart are conveyed to distinct sensory neurons in the brain. There, primary integration centers act as hubs that receive and integrate artery-brain circuit-derived and heart-brain circuit-derived signals and process them together with axonal connections and humoral cues from distant brain regions. To conclude the cardiovascular brain circuit, integration centers transmit the constantly modified signals to efferent neurons which transfer them back to the cardiovascular system. Importantly, primary integration centers are wired to and receive information from secondary brain centers that control a wide variety of brain traits encoded in engrams including immune memory, stress-regulating hormone release, pain, reward, emotions, and even motivated types of behavior. Finally, we explore the important possibility that brain effector neurons in the cardiovascular brain circuit network connect efferent signals to other peripheral organs including the immune system, the gut, the liver, and adipose tissue. The enormous recent progress vis-à-vis the cardiovascular brain circuit allows us to propose a novel neurobiology-centered cardiovascular disease hypothesis that we term the neuroimmune cardiovascular circuit hypothesis.

Melatonin and TGF-β-Mediated Release of Extracellular Vesicles

The immune system, unlike other systems, must be flexible and able to "adapt" to fully cope with lurking dangers. The transition from intracorporeal balance to homeostasis disruption is associated with activation of inflammatory signaling pathways, which causes modulation of the immunology response. Chemotactic cytokines, signaling molecules, and extracellular vesicles act as critical mediators of inflammation and participate in intercellular communication, conditioning the immune system's proper response. Among the well-known cytokines allowing for the development and proper functioning of the immune system by mediating cell survival and cell-death-inducing signaling, the tumor necrosis factor α (TNF-α) and transforming growth factor β (TGF-β) are noteworthy. The high bloodstream concentration of those pleiotropic cytokines can be characterized by anti- and pro-inflammatory activity, considering the powerful anti-inflammatory and anti-oxidative stress capabilities of TGF-β known from the literature. Together with the chemokines, the immune system response is also influenced by biologically active chemicals, such as melatonin. The enhanced cellular communication shows the relationship between the TGF-β signaling pathway and the extracellular vesicles (EVs) secreted under the influence of melatonin. This review outlines the findings on melatonin activity on TGF-β-dependent inflammatory response regulation in cell-to-cell communication leading to secretion of the different EV populations.

Investigation of electrical stimulation on phenotypic vascular smooth muscle cells differentiation in tissue-engineered small-diameter vascular graft

In the development of vascular tissue engineering, particularly in the case of small diameter vessels, one of the key obstacles is the blockage of these veins once they enter the in vivo environment. One of the contributing factors to this problem is the aberrant proliferation and migration of vascular smooth muscle cells (VSMCs) from the media layer of the artery to the interior of the channel. Two distinct phenotypes have been identified for smooth muscle cells, namely synthetic and contractile. Since the synthetic phenotype plays an essential role in the unusual growth and migration, the aim of this study was to convert the synthetic phenotype into the contractile one, which is a solution to prevent the abnormal growth of VSMCs. To achieve this goal, these cells were subjected to electrical signals, using a 1000 μA sinusoidal stimulation at 10 Hz for four days, with 20 min duration per 24 h. The morphological transformations and changes in the expression of vimentin, nestin, and β-actin proteins were then studied using ICC and flow cytometry assays. Also, the expression of VSMC specific markers such as smooth muscle myosin heavy chain (SMMHC) and smooth muscle alpha-actin (α-SMA) were evaluated using RT-PCR test. In the final phase of this study, the sheep decellularized vessel was employed as a scaffold for seeding these cells. Based on the results, electrical stimulation resulted in some morphological alterations in VSMCs. Furthermore, the observed reductions in the expression levels of vimentin, nestin and β-actin proteins and increase in the expression of SMMHC and α-SMA markers showed that it is possible to convert the synthetic phenotype to the contractile one using the studied regime of electrical stimulation. Finally, it can be concluded that electrical stimulation can significantly affect the phenotype of VSMCs, as demonstrated in this study.

MiR-146a encapsulated liposomes reduce vascular inflammatory responses through decrease of ICAM-1 expression, macrophage activation, and foam cell formation

Vascular insults can create an inflammatory cascade involving endothelial cell, smooth muscle cell, and macrophage activation which can eventually lead to vascular disease such as atherosclerosis. Several studies have identified microRNA 146a's (miR-146a) anti-inflammatory potential based on its role in regulating the nuclear factor kappa beta (NF-κβ) pathway. Therefore, in this study, we introduced exogenous miR-146a encapsulated by liposomes to lipopolysaccharide (LPS) stimulated vascular cells and macrophages to reduce inflammatory responses. First, the miR-146a encapsulated liposomes showed uniform size (radius 96.4 ± 4.22 nm) and round shape, long term stability (at least two months), high encapsulation efficiency (69.73 ± 0.07%), and were well transfected to human aortic endothelial cells (HAECs), human aortic smooth muscle cells (SMCs), and human differentiated monocytes (U937 cells). In addition, we demonstrated that miR-146a encapsulated liposomes reduced vascular inflammation responses in HAECs and SMCs through inhibition of ICAM-1 expression and decreased monocyte adhesion. In macrophages, miR-146a liposome treatment demonstrated decreased production of proinflammatory cytokines, tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β), as well as reduced oxidized low-density lipoprotein (ox-LDL) uptake and foam cell formation. Thus, based on these results, miR-146a encapsulated liposomes may be promising for reducing vascular inflammation by targeting its multiple associated mediators.

The Impact of Exercise on Immunity, Metabolism, and Atherosclerosis

Physical exercise represents an effective preventive and therapeutic strategy beneficially modifying the course of multiple diseases. The protective mechanisms of exercise are manifold; primarily, they are elicited by alterations in metabolic and inflammatory pathways. Exercise intensity and duration strongly influence the provoked response. This narrative review aims to provide comprehensive up-to-date insights into the beneficial effects of physical exercise by illustrating the impact of moderate and vigorous exercise on innate and adaptive immunity. Specifically, we describe qualitative and quantitative changes in different leukocyte subsets while distinguishing between acute and chronic exercise effects. Further, we elaborate on how exercise modifies the progression of atherosclerosis, the leading cause of death worldwide, representing a prime example of a disease triggered by metabolic and inflammatory pathways. Here, we describe how exercise counteracts causal contributors and thereby improves outcomes. In addition, we identify gaps that still need to be addressed in the future.

Thymosin β4 preserves vascular smooth muscle phenotype in atherosclerosis via regulation of low density lipoprotein related protein 1 (LRP1)

Atherosclerosis is a progressive, degenerative vascular disease and a leading cause of morbidity and mortality. In response to endothelial damage, platelet derived growth factor (PDGF)-BB induced phenotypic modulation of medial smooth muscle cells (VSMCs) promotes atherosclerotic lesion formation and destabilisation of the vessel wall. VSMC sensitivity to PDGF-BB is determined by endocytosis of Low density lipoprotein receptor related protein 1 (LRP1)-PDGFR β complexes to balance receptor recycling with lysosomal degradation. Consequently, LRP1 is implicated in various arterial diseases. Having identified Tβ4 as a regulator of LRP1-mediated endocytosis to protect against aortic aneurysm, we sought to determine whether Tβ4 may additionally function to protect against atherosclerosis, by regulating LRP1-mediated growth factor signalling. By single cell transcriptomic analysis, Tmsb4x, encoding Tβ4, strongly correlated with contractile gene expression and was significantly down-regulated in cells that adopted a modulated phenotype in atherosclerosis. We assessed susceptibility to atherosclerosis of global Tβ4 knockout mice using the ApoE-/- hypercholesterolaemia model. Inflammation, elastin integrity, VSMC phenotype and signalling were analysed in the aortic root and descending aorta. Tβ4KO; ApoE-/- mice develop larger atherosclerotic plaques than control mice, with medial layer degeneration characterised by accelerated VSMC phenotypic modulation. Defects in Tβ4KO; ApoE-/- mice phenocopied those in VSMC-specific LRP1 nulls and, moreover, were underpinned by hyperactivated LRP1-PDGFRβ signalling. We identify an atheroprotective role for endogenous Tβ4 in maintaining differentiated VSMC phenotype via LRP1-mediated PDGFRβ signalling.

Neuroimmune cardiovascular interfaces in atherosclerosis

Two pairs of biological systems acting over long distances have recently been defined as major participants in the regulation of physiological and pathological tissue reactions: i) the nervous and vascular systems form various blood-brain barriers and control axon growth and angiogenesis; and ii) the nervous and immune systems emerge as key players to direct immune responses and maintain blood vessel integrity. The two pairs have been explored by investigators in relatively independent research areas giving rise to the concepts of the rapidly expanding topics of the neurovascular link and neuroimmunology, respectively. Our recent studies on atherosclerosis led us to consider a more inclusive approach by conceptualizing and combining principles of the neurovascular link and neuroimmunology: we propose that the nervous system, the immune system and the cardiovascular system undergo complex crosstalks in tripartite rather than bipartite interactions to form neuroimmune cardiovascular interfaces (NICIs).

Role of Gut Microbiome in Atherosclerosis: Molecular and Therapeutic Aspects

Atherosclerosis is one of the most relevant and prevalent cardiovascular diseases of our time. It is one of the pathological entities that increases the morbidity and mortality index in the adult population. Pathophysiological connections have been observed between atherosclerosis and the gut microbiome (GM), represented by a group of microorganisms that are present in the gut. These microorganisms are vital for metabolic homeostasis in humans. Recently, direct and indirect mechanisms through which GM can affect the development of atherosclerosis have been studied. This has led to research into the possible modulation of GM and metabolites as a new target in the prevention and treatment of atherosclerosis. The goal of this review is to analyze the physiopathological mechanisms linking GM and atherosclerosis that have been described so far. We also aim to summarize the recent studies that propose GM as a potential target in atherosclerosis management.

Long non-coding RNAs at the crossroad of vascular smooth muscle cell phenotypic modulation in atherosclerosis and neointimal formation

Despite extraordinary advances in the comprehension of the pathophysiology of atherosclerosis and the employment of very effective treatments, cardiovascular diseases are still a major cause of mortality and represent a large share of health expenditure worldwide. Atherosclerosis is a disease affecting the medium and large arteries, which consists of a progressive accumulation of fatty substances, cellular waste products and fibrous elements, which culminates in the buildup of a plaque obstructing the blood flow. Endothelial dysfunction represents an early pathological event, favoring immune cells recruitment and triggering local inflammation. The release of inflammatory cytokines and other signaling molecules stimulates phenotypic modifications in the underlying vascular smooth muscle cells, which, in physiological conditions, are responsible for the maintenance of vessels architecture while regulating vascular tone. Vascular smooth muscle cells are highly plastic and may respond to disease stimuli by de-differentiating and losing their contractility, while increasing their synthetic, proliferative, and migratory capacity. This phenotypic switching is considered a pathological hallmark of atherogenesis and is ruled by the activation of selective gene programs. The advent of genomics and the improvement of sequencing technologies deepened our knowledge of the complex gene expression regulatory networks mediated by non-coding RNAs, and favored the rise of innovative therapeutic approaches targeting the non-coding transcriptome. In the context of atherosclerosis, long non-coding RNAs have received increasing attention as potential translational targets, due to their contribution to the molecular dynamics modulating the expression of vascular smooth muscle cells contractile/synthetic gene programs. In this review, we will focus on the most well-characterized long non-coding RNAs contributing to atherosclerosis by controlling expression of the contractile apparatus and genes activated in perturbed vascular smooth muscle cells.

Decoding the transcriptome of calcified atherosclerotic plaque at single-cell resolution

Atherogenesis involves an interplay of inflammation, tissue remodeling and cellular transdifferentiation (CTD), making it especially difficult to precisely delineate its pathophysiology. Here we use single-cell RNA sequencing and systems-biology approaches to analyze the transcriptional profiles of vascular smooth muscle cells (VSMCs) and endothelial cells (ECs) in calcified atherosclerotic core (AC) plaques and patient-matched proximal adjacent (PA) portions of carotid artery tissue from patients undergoing carotid endarterectomy. Our results reveal an anatomic distinction whereby PA cells express inflammatory mediators, while cells expressing matrix-secreting genes occupy a majority of the AC region. Systems biology analysis indicates that inflammation in PA ECs and VSMCs may be driven by TNFa signaling. Furthermore, we identify POSTN, SPP1 and IBSP in AC VSMCs, and ITLN1, SCX and S100A4 in AC ECs as possible candidate drivers of CTD in the atherosclerotic core. These results establish an anatomic framework for atherogenesis which forms the basis for exploration of a site-specific strategy for disruption of disease progression.

Single-cell RNA sequencing and systems biology are used to profile the human vascular cell populations in calcified atherosclerotic core plaques from carotid endarterectomy samples, showing an anatomic distinction between gene expression of inflammatory versus matrix-secreting factors.

Targeting the Crosstalk of Immune Response and Vascular Smooth Muscle Cells Phenotype Switch for Arteriovenous Fistula Maturation

Plaque formation, thrombosis, and embolism are the underlying causes of acute cardiovascular events such as myocardial infarction and stroke while early thrombosis and stenosis are common pathologies for the maturation failure of arteriovenous fistula (AVF). Chronic inflammation is a common underlying pathogenesis mediated by innate and adaptive immune response involving infiltration of immune cells and secretion of pro- and anti-inflammatory cytokines. Impaired immune cell infiltration and change in vascular smooth muscle cell (VSMC) phenotype play a crucial role in the underlying pathophysiology. However, the change in the phenotype of VSMCs in a microenvironment of immune cell infiltration and increased secretion of cytokines have not been investigated. Since change in VSMC phenotype regulates vessel remodeling after intimal injury, in this study, we investigated the effect of macrophages and pro-inflammatory cytokines, IL-6, IL-1β, and TNF-α, on the change in VSMC phenotype under in vitro conditions. We also investigated the expression of the markers of VSMC phenotypes in arteries with atherosclerotic plaques and VSMCs isolated from control arteries. We found that the inhibition of cytokine downstream signaling may mitigate the effect of cytokines on the change in VSMCs phenotype. The results of this study support that regulating or targeting immune cell infiltration and function might be a therapeutic strategy to mitigate the effects of chronic inflammation to attenuate plaque formation, early thrombosis, and stenosis, and thus enhance AVF maturation.

Conductance Artery Wall Layers and Their Respective Roles in the Clearance Functions

Evolutionary organization of the arterial wall into layers occurred concomitantly with the emergence of a highly muscularized, pressurized arterial system that facilitates outward hydraulic conductance and mass transport of soluble substances across the arterial wall. Although colliding circulating cells disperse potential energy within the arterial wall, the different layers counteract this effect: (1) the endothelium ensures a partial barrier function; (2) the media comprises smooth muscle cells capable of endocytosis/phagocytosis; (3) the outer adventitia and perivascular adipocytic tissue are the final receptacles of convected substances. While the endothelium forms a physical and a biochemical barrier, the medial layer is avascular, relying on the specific permeability properties of the endothelium for metabolic support. Different components of the media interact with convected molecules: medial smooth muscle cells take up numerous molecules via scavenger receptors and are capable of phagocytosis of macro/micro particles. The outer layers-the highly microvascularized innervated adventitia and perivascular adipose tissue-are also involved in the clearance functions of the media: the adventitia is the seat of immune response development, inward angiogenesis, macromolecular lymphatic drainage, and neuronal stimulation. Consequently, the clearance functions of the arterial wall are physiologically essential, but also may favor the development of arterial wall pathologies. This review describes how the walls of large conductance arteries have acquired physiological clearance functions, how this is determined by the attributes of the endothelial barrier, governed by endocytic and phagocytic capacities of smooth muscle cells, impacting adventitial functions, and the role of these clearance functions in arterial wall diseases.

DLEU2 modulates proliferation, migration and invasion of platelet-derived growth factor-BB (PDGF-BB)-induced vascular smooth muscle cells (VSMCs) via miR-212-5p/YWHAZ axis

DLEU2 has been proved to act as an oncogene in a variety of cancers, but its role in cardiovascular diseases is dearth of research. Thus, this study mainly discussed the effect and possible mechanism of DLEU2 on platelet-derived growth factor-BB (PDGF-BB)-triggered vascular smooth muscle cell (VSMC) injury. To obtain authentic results, the expressions of target genes in atherosclerosis serum were determined by reverse transcription quantitative PCR (RT-qPCR) and the protein levels were evaluated by Western blot. PDGF-BB was used to simply simulate the biological characteristics of VSMCs in vitro. The effect of DLEU2 on the biological behavior of PDGF-BB-induced VSMCs was analyzed by gain- and loss-of-function assays. Bioinformatics analysis, dual luciferase reporter assay, and Pearson correlation method were conducted to determine the relationship between target genes. The role of DLEU2/miR-212-5p/ YWHAZ (tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein zeta) axis in PDGF-BB-induced VSMCs was verified by rescue experiments. As a result, DLEU2 and YWHAZ were up-regulated, and miR-212-5p was down-regulated in atherosclerosis serum. Overexpressed DLEU2 facilitated the biological behavior of PDGF-BB-induced VSMCs, whilst siDLEU2 did the opposite. Moreover, overexpressed DLEU2 promoted proliferating cell nuclear antigen (PCNA) expression but repressed α-smooth muscle actin (α-SMA) and Calponin expressions, while it also enhanced YWHAZ expression via suppressing miR-212-5p. MiR-212-5p mimic and siYWHAZ reversed the effects of overexpressed DLEU2 on above biological characteristics and protein expressions in PDGF-BB-induced VSMCs, while the regulatory effect of miR-212-5p mimic was partially offset by overexpressed YWHAZ. Collectively, DLEU2 modulates PDGF-BB-induced VSMC injury via miR-212-5p/YWHAZ axis in atherosclerosis.

Mmu_circ_0000271 regulated the growth of ox-LDL-stimulated mouse vascular smooth muscle cells via sponging miR-5123

BACKGROUND

Atherosclerosis (AS) is a complex inflammatory disease of the arterial wall. Mmu_circ_0000271 was found to be aberrantly expressed in AS, but its function and mechanism in AS have not been reported.

OBJECTIVE

This study investigated the role of mmu_circ_0000271 in AS.

METHODS

Mmu_circ_0000271 were identified using UCSC website, RNase R treatment, and nuclear‑cytoplasmic extraction. And mouse vascular smooth muscle cells (VSMCs) were used to establish the AS cell model by treating oxidized low-density lipoprotein (ox-LDL, 50 μg/ml). Next, the expression of circ_0000271 in VSMCs was determined by quantitative real-time PCR. The effect of overexpressed or silenced circ_0000271 on ox-LDL-treated VSMCs viability, angiogenesis and invasion were detected by MTT, tube formation and transwell assays. The proteins expressions of proliferative and migratory markers were measured by western blot. After the target relationship predication between circ_0000271 and miR-5123, these experiments were performed again to evaluate the effect of miR-5123 inhibitor on AS model cells.

RESULTS

Mmu_circ_0000271 was stably and highly expressed in ox-LDL-treated VSMCs, and its expression was enriched in the cell cytoplasm. Circ_0000271 overexpression further promoted the ox-LDL-induced viability, angiogenesis and invasion, as well as the proliferation- and migration-related proteins in VSMCs, whereas circ_0000271 knockdown had the opposite effect. Moreover, circ_0000271 was found to target miR-5123 and circ_0000271 overexpression suppressed its expression. And miR-5123 inhibitor was capable of reversing the effect of shcirc_0000271 on AS model cells.

CONCLUSION

Mmu_circ_0000271 regulated ox-LDL-induced VSMC proliferation and migration through bind to miR-5123, and it could serve as a potential biomarker for AS.

Translation of Cellular Senescence to Novel Therapeutics: Insights From Alternative Tools and Models

Increasing chronological age is the greatest risk factor for human diseases. Cellular senescence (CS), which is characterized by permanent cell-cycle arrest, has recently emerged as a fundamental mechanism in developing aging-related pathologies. During the aging process, senescent cell accumulation results in senescence-associated secretory phenotype (SASP) which plays an essential role in tissue dysfunction. Although discovered very recently, senotherapeutic drugs have been already involved in clinical studies. This review gives a summary of the molecular mechanisms of CS and its role particularly in the development of cardiovascular diseases (CVD) as the leading cause of death. In addition, it addresses alternative research tools including the nonhuman and human models as well as computational techniques for the discovery of novel therapies. Finally, senotherapeutic approaches that are mainly classified as senolytics and senomorphics are discussed.

Inflammation and atherosclerosis: signaling pathways and therapeutic intervention

Atherosclerosis is a chronic inflammatory vascular disease driven by traditional and nontraditional risk factors. Genome-wide association combined with clonal lineage tracing and clinical trials have demonstrated that innate and adaptive immune responses can promote or quell atherosclerosis. Several signaling pathways, that are associated with the inflammatory response, have been implicated within atherosclerosis such as NLRP3 inflammasome, toll-like receptors, proprotein convertase subtilisin/kexin type 9, Notch and Wnt signaling pathways, which are of importance for atherosclerosis development and regression. Targeting inflammatory pathways, especially the NLRP3 inflammasome pathway and its regulated inflammatory cytokine interleukin-1β, could represent an attractive new route for the treatment of atherosclerotic diseases. Herein, we summarize the knowledge on cellular participants and key inflammatory signaling pathways in atherosclerosis, and discuss the preclinical studies targeting these key pathways for atherosclerosis, the clinical trials that are going to target some of these processes, and the effects of quelling inflammation and atherosclerosis in the clinic.

Identification of HMOX1 as a Critical Ferroptosis-Related Gene in Atherosclerosis

Ferroptosis is a novel form of programmed iron-dependent cell death. The ferroptosis-related genes (FRGs) have been recognized as biomarkers for cancers. Increasing evidence has indicated that ferroptosis is involved in the process of atherosclerosis. However, the potential FRGs used for the diagnosis, prognosis and therapy for atherosclerosis are still unclear. We aimed to identify the ferroptosis-related differentially expressed genes (DEGs) of atherosclerosis. We downloaded the mRNA-sequencing data of patients with atherosclerosis from the Gene Expression Omnibus (GEO) database. HMOX1 was identified as an essential ferroptosis-related DEG by bioinformatic analysis of the GSE28829 and GSE43292 datasets. The pro-ferroptotic effect of HMOX1 was validated through cell experiments. Then we conducted a single-gene analysis of HMOX1 and found that high-expression of HMOX1 in atherosclerotic plaques was accompanied by matrix metalloproteinases (MMPs) producing and M0 macrophages infiltration. Taken together, our present study suggested HMOX1 as a potential diagnostic biomarker for atherosclerosis and provided more evidence about the vital role of ferroptosis in atherosclerosis progression.

Highly Purified Eicosapentaenoic Acid Alleviates the Inflammatory Response and Oxidative Stress in Macrophages during Atherosclerosis via the miR-1a-3p/sFRP1/Wnt/PCP-JNK Pathway

Highly purified eicosapentaenoic acid (EPA) has shown great effects in the prevention of atherosclerosis. In a murine model, it significantly reduced plaque accumulation, lowered plasma lipid levels, and decreased inflammation levels, which was also observed in vitro. Using microRNA sequencing, we identified differentially expressed microRNAs, among which miR-1a-3p was selected for further validation. Overexpression of miR-1a-3p in RAW264.7 cells worsened lipid accumulation, increased oxidative stress, and exacerbated inflammatory responses whereas its downregulation produced the opposite results. Potential targets of miR-1a-3p were analyzed by prediction tools. Then, secreted frizzled-related protein 1 (sFRP1), an antagonist of the Wnt pathway, was confirmed as the target gene of miR-1a-3p by a dual-luciferase reporter assay. Further research showed that in macrophages, EPA influenced the activation of the Wnt/planar cell polarity-c-Jun N-terminal kinase (Wnt/PCP-JNK) axis, which is consistent with the phenomenon that miR-1a-3p has an impact on this same axis. Collectively, our findings suggest that EPA mitigates inflammatory responses and oxidative responses both in vivo and in vitro by targeting the miR-1a-3p/sFRP1/Wnt/PCP-JNK axis in macrophages, which may explain the cardioprotective role of EPA and promote the application of EPA in clinical practice.

Highly Purified Eicosapentaenoic Acid Alleviates the Inflammatory Response and Oxidative Stress in Macrophages during Atherosclerosis via the miR-1a-3p/sFRP1/Wnt/PCP-JNK Pathway

Highly purified eicosapentaenoic acid (EPA) has shown great effects in the prevention of atherosclerosis. In a murine model, it significantly reduced plaque accumulation, lowered plasma lipid levels, and decreased inflammation levels, which was also observed in vitro. Using microRNA sequencing, we identified differentially expressed microRNAs, among which miR-1a-3p was selected for further validation. Overexpression of miR-1a-3p in RAW264.7 cells worsened lipid accumulation, increased oxidative stress, and exacerbated inflammatory responses whereas its downregulation produced the opposite results. Potential targets of miR-1a-3p were analyzed by prediction tools. Then, secreted frizzled-related protein 1 (sFRP1), an antagonist of the Wnt pathway, was confirmed as the target gene of miR-1a-3p by a dual-luciferase reporter assay. Further research showed that in macrophages, EPA influenced the activation of the Wnt/planar cell polarity-c-Jun N-terminal kinase (Wnt/PCP-JNK) axis, which is consistent with the phenomenon that miR-1a-3p has an impact on this same axis. Collectively, our findings suggest that EPA mitigates inflammatory responses and oxidative responses both in vivo and in vitro by targeting the miR-1a-3p/sFRP1/Wnt/PCP-JNK axis in macrophages, which may explain the cardioprotective role of EPA and promote the application of EPA in clinical practice.

Ginsenoside Rh1 Inhibits Angiotensin II-Induced Vascular Smooth Muscle Cell Migration and Proliferation through Suppression of the ROS-Mediated ERK1/2/p90RSK/KLF4 Signaling Pathway

Vascular smooth muscle cell (VSMC) proliferation and migration play key roles in the progression of atherosclerosis and restenosis. A variety of ginsenosides exert various cardiovascular benefits. However, whether and how ginsenoside Rh1 (Rh1) inhibits VSMC dysfunction remain unclear. Here, we investigated the inhibitory effects of Rh1 on rat aortic smooth muscle cell (RASMC) migration and proliferation induced by angiotensin II (Ang II) and the underlying mechanisms. Cell proliferation and migration were evaluated using sulforhodamine B and wound-healing assay. The molecular mechanisms were investigated using Western blotting, quantitative reverse-transcription polymerase chain reaction analysis, immunofluorescence staining, and luciferase assay. Reactive oxygen species (ROS) production was measured using dihydroethidium and MitoSOX staining. We found that Rh1 dose-dependently suppressed Ang II-induced cell proliferation and migration. Concomitantly, Ang II increased protein levels of osteopontin, vimentin, MMP2, MMP9, PCNA, and cyclin D1, while these were reduced by Rh1 pretreatment. Notably, Ang II enhanced both the protein expression and promoter activity of KLF4, a key regulator of phenotypic switching, whereas pretreatment with Rh1 reversed these effects. Mechanistically, the effects of Rh1 on VSMC proliferation and migration were found to be associated with inhibition of ERK1/2/p90RSK signaling. Furthermore, the inhibitory effects of Rh1 were accompanied by inhibition of ROS production. In conclusion, Rh1 inhibited the Ang II-induced migration and proliferation of RASMCs by suppressing the ROS-mediated ERK1/2/p90RSK signaling pathway.

Tissue Clearing Approaches in Atherosclerosis

Recent advances in cardiovascular research have led to a more comprehensive understanding of molecular mechanisms of atherosclerosis. It has become apparent that the disease involves three layers of the arterial wall: the intima, the media, and a connective tissue coat termed the adventitia. It is also now appreciated that arteries are surrounded by adipose and neuronal tissues. In addition, adjacent to and within the adventitia, arteries are embedded in a loose connective tissue containing blood vessels (vasa vasora) and lymph vessels, artery-draining lymph nodes and components of the peripheral nervous system, including periarterial nerves and ganglia. During atherogenesis, each of these tissues undergoes marked structural and cellular alterations. We propose that a better understanding of these cell-cell and cell-tissue interactions may considerably advance our understanding of cardiovascular disease pathogenesis. Methods to acquire subcellular optical access to the intact tissues surrounding healthy and diseased arteries are urgently needed to achieve these aims. Tissue clearing is a landmark next-generation, three-dimensional (3D) microscopy technique that allows to image large-scale hitherto inaccessible intact deep tissue compartments. It allows for detailed reconstructions of arteries by a combination of labelling, clearing, advanced microscopies and other imaging and data-analysis tools. Here, we describe two distinct tissue clearing protocols; solvent-based modified three-dimensional imaging of solvent-cleared organs (3DISCO) clearing and another using aqueous-based 2,2'-thiodiethanol (TDE) clearing, both of which complement each other.

Adipocyte Phenotype Flexibility and Lipid Dysregulation

The prevalence of obesity and associated cardiometabolic diseases continues to rise, despite efforts to improve global health. The adipose tissue is now regarded as an endocrine organ since its multitude of secretions, lipids chief among them, regulate systemic functions. The loss of normal adipose tissue phenotypic flexibility, especially related to lipid homeostasis, appears to trigger cardiometabolic pathogenesis. The goal of this manuscript is to review lipid balance maintenance by the lean adipose tissue’s propensity for phenotype switching, obese adipose tissue’s narrower range of phenotype flexibility, and what initial factors account for the waning lipid regulatory capacity. Metabolic, hypoxic, and inflammatory factors contribute to the adipose tissue phenotype being made rigid. A better grasp of normal adipose tissue function provides the necessary context for recognizing the extent of obese adipose tissue dysfunction and gaining insight into how pathogenesis evolves.

Association of IL-6 promoter polymorphism hotspots (- 174G/C and - 572G/C) with cardiovascular disease risk factors

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of death globally, despite the recent advancements in clinical research. Early diagnosis of CVD and prevention of future complications are important for the management of CVD. In the present study, we determined the genotypic linkage of interleukin-6 (IL-6) promoters with the clinical, biochemical, and inflammatory markers of CVD in the Saudi population.

MATERIALS AND METHODS

The study consisted of 89 patients (male and female) with CVD who were admitted at the King Abdulaziz university hospital, Jeddah, Saudi Arabia. The biochemical parameters were evaluated using an automated chemistry analyzer, and inflammatory markers were measured using specific enzyme-linked immunosorbent assay (ELISA) kits. For genotypic analysis, Sanger sequencing was performed. We observed a statistically significant association (p < 0.05) between GG (66.29%), GC (30.34%), and CC (3.37%) genotypes at the - 174G/C (rs1800795) hotspot and neopterin levels. However, the genotypes at the - 572G/C (rs1800796) hotspot did not show any association with age, gender, obesity, diabetes, hypertension, dyslipidemia, smoking, and coronary artery status. In addition, no significant association was observed with biochemical and inflammatory markers, namely fasting blood sugar, glycated hemoglobin A1c, creatinine, total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol, IL-6, and C-reactive protein. The comparison between different possible genotypic groups and CVD risk factors showed a statistically significant (p < 0.05) association between the male gender and HDL with GG, rs1800795 group vs. GC, rs1800796 group. Similarly, neopterin level was also found to be significantly (p < 0.05) associated with the genotypes GC, rs1800795, and GG, rs1800796. Additionally, the male gender (p < 0.01), age (p < 0.05), serum creatinine (p < 0.001), and neopterin (p < 0.05) were found to be significantly associated with GG, rs1800795 + GG, rs1800796, GC, rs1800795 + GC, and rs1800796 GC.

CONCLUSION

The direct association of neopterin level with IL-6 promoter polymorphism at - 174G/C (rs1800795) hotspot indicated the role of inflammation in CVD pathogenesis in the Saudi population.

Proteomimetics of Natural Regulators of JAK-STAT Pathway: Novel Therapeutic Perspectives

The JAK-STAT pathway is a crucial cellular signaling cascade, including an intricate network of Protein-protein interactions (PPIs) responsible for its regulation. It mediates the activities of several cytokines, interferons, and growth factors and transduces extracellular signals into transcriptional programs to regulate cell growth and differentiation. It is essential for the development and function of both innate and adaptive immunities, and its aberrant deregulation was highlighted in neuroinflammatory diseases and in crucial mechanisms for tumor cell recognition and tumor-induced immune escape. For its involvement in a multitude of biological processes, it can be considered a valuable target for the development of drugs even if a specific focus on possible side effects associated with its inhibition is required. Herein, we review the possibilities to target JAK-STAT by focusing on its natural inhibitors as the suppressor of cytokine signaling (SOCS) proteins. This protein family is a crucial checkpoint inhibitor in immune homeostasis and a valuable target in immunotherapeutic approaches to cancer and immune deficiency disorders.

A novel circUBR4/miR-491-5p/NRP2 ceRNA network regulates oxidized low-density lipoprotein-induced proliferation and migration in vascular smooth muscle cells

ABSTRACT

Vascular smooth muscle cells (VSMCs) play critical roles in the progression of atherosclerosis. Circular RNA (circRNA) ubiquitin protein ligase E3 component n-recognin 4 (circUBR4) has been shown to regulate VSMC migration and proliferation. Here, we sought to identify the mechanism in the regulation of circUBR4. CircUBR4, microRNA (miR)-491-5p and Neuropilin-2 (NRP2) were quantified by quantitative real-time PCR (qRT-PCR) and western blot. Cell proliferation was evaluated by Cell Counting Kit-8 (CCK-8) and 5-Ethynyl-2'-Deoxyuridine (EDU) assays. Cell migration was examined by wound-healing and transwell invasion assays. The direct relationship between miR-491-5p and circUBR4 or NRP2 was validated by dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. Our data indicated that in VSMCs, ox-LDL induced circUBR4 expression. Silencing endogenous circUBR4 attenuated VSMC proliferation and migration induced by ox-LDL. Mechanistically, circUBR4 targeted miR-491-5p by pairing to miR-491-5p. Moreover, miR-491-5p was identified as a downstream mediator of circUBR4 function in ox-LDL-treated VSMCs. NRP2 was a direct target of miR-491-5p, and circUBR4 acted as a competing endogenous RNA (ceRNA) for miR-491-5p to regulate NRP2 expression. Additionally, NRP2 was a functionally downstream effector of miR-491-5p in regulating ox-LDL-evoked VSMC proliferation and migration. Our findings identify a new ceRNA network, the circUBR4/miR-491-5p/NRP2 axis, for the regulation of circUBR4 in VSMC migration and proliferation.

Down-regulation of microRNA-342-5p or Up-regulation of Wnt3a Inhibits Angiogenesis and Maintains Atherosclerotic Plaque Stability in Atherosclerosis Mice

Evidence has demonstrated that microRNA-342-5p (miR-342-5p) is implicated in atherosclerosis (AS), but little is known regarding its intrinsic regulatory mechanisms. Here, we aimed to explore the effect of miR-342-5p targeting Wnt3a on formation of vulnerable plaques and angiogenesis of AS. ApoE^-/- mice were fed with high-fat feed for 16 w to replicate the AS vulnerable plaque model. miR-342-5p and Wnt3a expression in aortic tissues of AS were detected. The target relationship between miR-342-5p and Wnt3a was verified. Moreover, ApoE^-/- mice were injected with miR-342-5p antagomir and overexpression-Wnt3a vector to test their functions in serum lipid levels, inflammatory and oxidative stress-related cytokines, aortic plaque stability and angiogenesis in plaque of AS mice. miR-342-5p expression was enhanced and Wnt3a expression was degraded in aortic tissues of AS mice and miR-342-5p directly targeted Wnt3a. Up-regulating Wnt3a or down-regulating miR-342-5p reduced blood lipid content, inflammatory and oxidative stress levels, the vulnerability of aortic tissue plaque and inhibited angiogenesis in aortic plaque of AS mice. Functional studies show that depleting miR-342-5p can stabilize aortic tissue plaque and reduce angiogenesis in plaque in AS mice via restoring Wnt3a.

The Combined Regulation of Long Non-coding RNA and RNA-Binding Proteins in Atherosclerosis

Atherosclerosis is a complex disease closely related to the function of endothelial cells (ECs), monocytes/macrophages, and vascular smooth muscle cells (VSMCs). Despite a good understanding of the pathogenesis of atherosclerosis, the underlying molecular mechanisms are still only poorly understood. Therefore, atherosclerosis continues to be an important clinical issue worthy of further research. Recent evidence has shown that long non-coding RNAs (lncRNAs) and RNA-binding proteins (RBPs) can serve as important regulators of cellular function in atherosclerosis. Besides, several studies have shown that lncRNAs are partly dependent on the specific interaction with RBPs to exert their function. This review summarizes the important contributions of lncRNAs and RBPs in atherosclerosis and provides novel and comprehensible interaction models of lncRNAs and RBPs.

Potential Vasculoprotective Effects of Blackcurrant (Ribes nigrum) Extract in Diabetic KK-Ay Mice

Polyphenols are bioactive compounds found naturally in fruits and vegetables; they are widely used in disease prevention and health maintenance. Polyphenol-rich blackcurrant extract (BCE) exerts beneficial effects on vascular health in menopausal model animals. However, the vasculoprotective effects in diabetes mellitus (DM) and atherosclerotic vascular disease secondary to DM are unknown. Therefore, we investigated whether BCE is effective in preventing atherosclerosis using KK-A^y mice as a diabetes model. The mice were divided into three groups and fed a high-fat diet supplemented with 1% BCE (BCE1), 3% BCE (BCE2), or Control for 9 weeks. The mice in the BCE2 group showed a considerable reduction in the disturbance of elastic lamina, foam cell formation, and vascular remodeling compared to those in the BCE1 and Control groups. Immunohistochemical staining indicated that the score of endothelial nitric oxide synthase staining intensity was significantly higher in both BCE2 (2.9) and BCE1 (1.9) compared to that in the Control (1.1). Furthermore, the score for the percentage of alpha-smooth muscle actin was significantly lower in the BCE2 (2.9%) than in the Control (2.1%). Our results suggest that the intake of anthocyanin-rich BCE could have beneficial effects on the blood vessels of diabetic patients.

The effects of a biodegradable Mg-based alloy on the function of VSMCs via immunoregulation of macrophages through Mg-induced responses

Background

Restenosis is one of the worst side effects of percutaneous coronary intervention (PCI) due to neointima formation resulting from the excessive proliferation and migration of vascular smooth muscle cells (VSMCs) and continuous inflammation. Biodegradable Mg-based alloy is a promising candidate material because of its good mechanical properties and biocompatibility, and biodegradation of cardiovascular stents. Although studies have shown reduced neointima formation after Mg-based CVS implantation in vivo, these findings were inconsistent with in vitro studies, demonstrating magnesium-mediated promotion of the proliferation and migration of VSMCs. Given the vital role of activated macrophage-driven inflammation in neointima formation, along with the well-demonstrated crosstalk between macrophages and VSMCs, we investigated the interactions of a biodegradable Mg-Nd-Zn-Zr alloy (denoted JDBM), which is especially important for cardiovascular stents, with VSMCs via macrophages.

Methods

JDBM extracts and MgCl₂ solutions were prepared to study their effect on macrophages. To study the effects of the JDBM extracts and MgCl₂ solutions on the function of VSMCs via immunoregulation of macrophages, conditioned media (CM) obtained from macrophages was used to establish a VSMC-macrophage indirect coculture system.

Results

Our results showed that both JDBM extracts and MgCl₂ solutions significantly attenuated the inflammatory response stimulated by lipopolysaccharide (LPS)-activated macrophages and converted macrophages into M2-type cells. In addition, JDBM extracts and MgCl₂ solutions significantly decreased the expression of genes related to VSMC phenotypic switching, migration, and proliferation in macrophages. Furthermore, the proliferation, migration, and proinflammatory phenotypic switching of VSMCs were significantly inhibited when the cells were incubated with CMs from macrophages treated with LPS + extracts or LPS + MgCl₂ solutions.

Conclusions

Taken together, our results suggested that the magnesium in the JDBM extract could affect the functions of VSMCs through macrophage-mediated immunoregulation, inhibiting smooth muscle hyperproliferation to suppress restenosis after implantation of a biodegradable Mg-based stent.

Phoenixin-14 regulates proliferation and apoptosis of vascular smooth muscle cells by modulation of KCNQ1OT1/miR-183-3p/CTNNB1 axis

Phoenixin-14 has been reported to be implicated in the process of blood glucose metabolism, reproduction, lipid deposition and cardioprotection. However, the role of phoenixin-14 in vascular smooth muscle cells (VSMCs) remains unkown. In this study, we focused on the effects of phoenixin-14 on VSMCs under oxidized low-density lipoprotein (ox-LDL) treatment. The experimental results demonstrated that phoenixin-14 inhibited mRNA level and nuclear translocation of β-catenin. Functionally, phoenixin-14 inhibited cell proliferation and facilitated apoptosis of VSMCs under ox-LDL stimulation, and CTNNB1 overexpression reversed these effects. Mechanistically, KCNQ1OT1 interacted with miR-183-3p to upregulate CTNNB1 in VSMCs. Furthermore, CTNNB1 expression was negatively correlated with miR-183-3p but positively associated with KCNQ1OT1. Rescue assays indicated that KCNQ1OT1 overexpression or Lithium chloride (LiCl) treatment reversed the effects of phoenixin-14 on proliferation and apoptosis of ox-LDL-stimulated VSMCs. In summary, phoenixin-14 regulates proliferation and apoptosis of ox-LDL-treated VSMCs by regulating the KCNQ1OT1/miR-183-3p/CTNNB1 axis.

Insulin action at a molecular level - 100 years of progress

The discovery of insulin 100 years ago and its application to the treatment of human disease in the years since have marked a major turning point in the history of medicine. The availability of purified insulin allowed for the establishment of its physiological role in the regulation of blood glucose and ketones, the determination of its amino acid sequence, and the solving of its structure. Over the last 50 years, the function of insulin has been applied into the discovery of the insulin receptor and its signaling cascade to reveal the role of impaired insulin signaling-or resistance-in the progression of type 2 diabetes. It has also become clear that insulin signaling can impact not only classical insulin-sensitive tissues, but all tissues of the body, and that in many of these tissues the insulin signaling cascade regulates unexpected physiological functions. Despite these remarkable advances, much remains to be learned about both insulin signaling and how to use this molecular knowledge to advance the treatment of type 2 diabetes and other insulin-resistant states.

Bench-to-Bedside in Vascular Medicine: Optimizing the Translational Pipeline for Patients With Peripheral Artery Disease

Peripheral arterial disease is a growing worldwide problem with a wide spectrum of clinical severity and is projected to consume >$21 billion per year in the United States alone. While vascular researchers have brought several therapies to the clinic in recent years, few of these approaches have leveraged advances in high-throughput discovery screens, novel translational models, or innovative trial designs. In the following review, we discuss recent advances in unbiased genomics and broader omics technology platforms, along with preclinical vascular models designed to enhance our understanding of disease pathobiology and prioritize targets for additional investigation. Furthermore, we summarize novel approaches to clinical studies in subjects with claudication and ischemic ulceration, with an emphasis on streamlining and accelerating bench-to-bedside translation. By providing a framework designed to enhance each aspect of future clinical development programs, we hope to enrich the pipeline of therapies that may prevent loss of life and limb for those with peripheral arterial disease.

lncRNA ZFAS1 promotes the ox-LDL induced proliferation, invasion and migration of vascular smooth muscle cells

Atherosclerosis is a chronic progressive inflammatory vascular disease. The dysfunction of vascular smooth muscle cells (VSMCs) induced by oxidized low-density lipoprotein (ox-LDL) contributes to the formation of atherosclerotic lesions. Additionally, upregulation of the long non-coding RNA zinc finger antisense 1 (ZFAS1) was observed in the plaques of patients with atherosclerosis. The aim of the present study was to explore the functional role of ZFAS1 in atherosclerosis progression. Reverse transcription-quantitative PCR was performed to analyze ZFAS1 mRNA expression, and western blotting was performed to determine the protein expression levels of Ki67, proliferating cell nuclear antigen (PCNA), matrix metallopeptidase (MMP)2 and MMP9. The Cell Counting Kit-8 assay was used to test cell viability. Finally, wound healing and Transwell chamber assays were performed to evaluate cell migration and invasion, respectively. The current findings demonstrated that ZFAS1 expression was upregulated by ox-LDL stimulation in VSMCs. Moreover, ZFAS1 overexpression promoted the ox-LDL-induced proliferation, migration and invasion of VSMCs, and upregulated the expression levels of proteins associated with cellular proliferation (Ki67 and PCNA), migration and invasion (MMP2 and 9). By contrast, ZFAS1-knockdown inhibited the proliferation, migration and invasion of VSMCs, and suppressed cell proliferation-, migration- and invasion-associated protein expression. In conclusion, ZFAS1 promoted the ox-LDL-induced proliferation, invasion and migration of VSMCs. Thus, ZFAS1 may represent a novel biomarker for dysfunction of VSMCs in the pathological condition of atherosclerosis.

Uric acid can enhance MAPK pathway-mediated proliferation in rat primary vascular smooth muscle cells via controlling of mitochondria and caspase-dependent cell death

Hyperuricemia may be a risk factor for cardiovascular diseases such as hypertension and atherosclerosis, but the mechanisms underlying uric acid-induced pathological conditions remain unknown. In this study, we investigated the effect of short time and long-term administration of increasing uric acid concentrations on cell viability, proliferative and apoptotic pathways in vascular smooth muscle cells (VSMCs). Cell viability/proliferation was determined with WST-1 assay. Expression levels of mitogen-activated protein kinases (MAPKs) (phosphorylated (p)-p38 and p-p44/42 MAPK), extrinsic (caspase 3, caspase 8), and intrinsic (B-cell lymphoma-extra-large (Bcl-xL)) apoptotic pathway proteins were measured by Western blotting. In order to assess the proliferative effects of uric acid incubations on VSMCs, we monitored the proliferative/apoptosis signaling pathways for up to 24 h. Our results indicated that uric acid increases cell viability at time and dose-dependently in VSMCs. Immunoblotting results showed that uric acid treatment elevated the expression level of p-p38 MAPK but did markedly reduce the protein levels of p-p44/42, compared with all the uric acid doses-treated VSMCs, especially at 1 h. Uric acid stimulation increased caspase-3 protein levels and decreased Bcl-xL, but did not alter caspase-8 protein expression at the same dose and time. Furthermore, low uric acid incubations (0-7.5 mg/dL) did not affect any signaling pathways for long time points (6-24 h). In conclusion, our study demonstrates for the first time that VSMCs induced with uric acid can affect cell viability, proliferative, and apoptosis pathways at the widest time and dose range. These findings provide a better understanding of the uric acid effects related to vascular impairments.

Resistin-like molecule beta augments phenotypic modulation of human aortic smooth muscle cell triggered by high glucose

Vascular muscle cells (VSMCs) participate in the pathophysiology of atherosclerosis. Resistin-like molecule beta (Relmβ) contributes to atherosclerosis development by activating macrophage. This study aims to investigate whether Relmβ regulates VSMC phenotypic modulation under high glucose environment. Human aortic vascular smooth muscle cells were cultured and treated with Relmβ in the presence or absence of high glucose. VSMC phenotypic modulation was assessed by expression of related markers. The migration of VSMCs was detected by wound healing assay and transwell assay. The proliferation of VSMCs was measured using CCK-8 assay. In this study, we observed that Relmβ modulated VSMC phenotypic modulation by down-regulating expression of smooth muscle α-actin (α-SMA), smooth muscle myosin heavy chain (SM-MHC), and calponin while up-regulating expression of osteopontin (OPN). Relmβ increased the expression of inflammatory genes in VSMCs. Relmβ also augmented VSMCs migration as well as proliferation. It is worth noting that all the effects of VSMCs were enhanced upon high glucose stimulation. The phosphorylation levels of p38MAPK and ERK1/2 were increased by co-treatment with Relmβ and high glucose. The p38 MAPK pathway inhibitor RWJ64809 and pERK1/2 inhibitor PD98059 significantly inhibited the proliferation of VSMCs induced by Relmβ and high glucose. Our results provide evidence that Relmβ augments phenotypic modulation and migration of human aortic smooth muscle cell induced by high glucose. Relmβ might be a potential target for treatment of atherosclerosis induced by hyperglycemia.

Mueller polarimetric imaging for fast macroscopic mapping of microscopic collagen matrix remodeling by smooth muscle cells

Smooth muscle cells (SMCs) are critical players in cardiovascular disease development and undergo complex phenotype switching during disease progression. However, SMC phenotype is difficult to assess and track in co-culture studies. To determine the contractility of SMCs embedded within collagen hydrogels, we performed polarized light imaging and subsequent analysis based on Mueller matrices. Measurements were made both in the absence and presence of endothelial cells (ECs) in order to establish the impact of EC-SMC communication on SMC contractility. The results demonstrated that Mueller polarimetric imaging is indeed an appropriate tool for assessing SMC activity which significantly modifies the hydrogel retardance in the presence of ECs. These findings are consistent with the idea that EC-SMC communication promotes a more contractile SMC phenotype. More broadly, our findings suggest that Mueller polarimetry can be a useful tool for studies of spatial heterogeneities in hydrogel remodeling by SMCs.

Protein deglycase DJ-1 deficiency induces phenotypic switching in vascular smooth muscle cells and exacerbates atherosclerotic plaque instability

Protein deglycase DJ‐1 (DJ‐1) is a multifunctional protein involved in various biological processes. However, it is unclear whether DJ‐1 influences atherosclerosis development and plaque stability. Accordingly, we evaluated the influence of DJ‐1 deletion on the progression of atherosclerosis and elucidate the underlying mechanisms. We examine the expression of DJ‐1 in atherosclerotic plaques of human and mouse models which showed that DJ‐1 expression was significantly decreased in human plaques compared with that in healthy vessels. Consistent with this, the DJ‐1 levels were persistently reduced in atherosclerotic lesions of ApoE^−/− mice with the increasing time fed by western diet. Furthermore, exposure of vascular smooth muscle cells (VSMCs) to oxidized low‐density lipoprotein down‐regulated DJ‐1 in vitro. The canonical markers of plaque stability and VSMC phenotypes were evaluated in vivo and in vitro. DJ‐1 deficiency in Apoe^−/− mice promoted the progression of atherosclerosis and exaggerated plaque instability. Moreover, isolated VSMCs from Apoe^−/−DJ‐1^−/− mice showed lower expression of contractile markers (α‐smooth muscle actin and calponin) and higher expression of synthetic indicators (osteopontin, vimentin and tropoelastin) and Kruppel‐like factor 4 (KLF4) by comparison with Apoe^−/−DJ‐1^+/+ mice. Furthermore, genetic inhibition of KLF4 counteracted the adverse effects of DJ‐1 deletion. Therefore, our results showed that DJ‐1 deletion caused phenotype switching of VSMCs and exacerbated atherosclerotic plaque instability in a KLF4‐dependent manner.

miR-140-5p regulates vascular smooth muscle cell viability, migration and apoptosis by targeting ROBO4 gene expression in atherosclerosis

MicroRNAs (miRs) are essential regulators of atherosclerosis (AS) development; however, the pathogenic roles of miR-140-5p during AS development are not completely understood. The present study investigated the effects of miR‑140-5p on human vascular smooth muscle cells (VSMCs) and its target gene. miR-140-5p and roundabout guidance receptor 4 (ROBO4) mRNA expression levels were determined by performing reverse transcription-quantitative PCR. ROBO4 protein expression levels were analyzed via western blotting. Cell viability, migration, invasion and apoptosis were evaluated by conducting Cell Counting Kit-8, Transwell and flow cytometry assays, respectively. The binding of miR-140-5p to ROBO4 mRNA was verified using the dual-luciferase reporter assay. miR-140-5p was highly expressed in the plaque-containing artery tissues of patients with AS compared with healthy control tissues. Oxidized-low density lipoprotein (ox-LDL) treatment increased miR-140-5p expression and decreased ROBO4 expression in human VSMCs, which promoted VSMC viability, migration and invasion, but suppressed apoptosis compared with the control group. The effects of ox-LDL treatment on VSMCs were attenuated by miR-140-5p inhibitor. miR-140-5p directly bound to the 3'-untranslated region of ROBO4 mRNA. ROBO4 overexpression mitigated the effects of ox-LDL treatment on VSMC viability, migration, invasion and apoptosis. Therefore, the present study suggested that high level miR-140-5p expression promoted VSMC viability, migration, and invasion, and suppressed VSMC apoptosis by reducing ROBO4 gene expression. The present study provided novel insights into AS pathogenesis that may aid the development of new strategies for the treatment and prevention of AS.

Kahweol, a Diterpenoid Molecule, Inhibits CTGF-Dependent Synthetic Phenotype Switching and Migration in Vascular Smooth Muscle Cells

Vascular smooth muscle cell (VSMC) phenotype switching from contractile to synthetic is essential for proliferation and migration in vascular pathophysiology. Connective tissue growth factor (CTGF) is a matricellular protein involved in cell adhesion, migration, and proliferation. Kahweol, a diterpene molecule in arabica coffee beans, has been reported to have anti-inflammatory, antiproliferative, and apoptotic effects in many cells. However, in VSMCs, the effects of kahweol on CTGF activities have not been investigated. Thus, in this study, the effects and associated mechanisms of kahweol in CTGF-dependent phenotype switching and migration in VSMCs were examined. Experiments were performed on primary rat aortic smooth muscle cells and a rat VSMC line, A7r5. Western blot analysis was used to determine the protein levels. The mRNA levels of synthetic markers were measured by qRT-PCR. Migration of VSMCs was evaluated by wound healing and transwell assays. Kahweol reduced the angiotensin II (Ang II)-induced CTGF expression. Further, kahweol inhibited expressions of synthetic phenotype markers of VSMC. The kahweol-reduced synthetic marker protein levels were reversed by the administration of rCTGF. However, expressions of contractile phenotype markers of VSMC were not affected. Kahweol suppressed Ang II-stimulated VSMC migration. Moreover, kahweol downregulated Ang II-induced p-FAK, p-Erk, and Yes-associated protein (YAP) protein expressions. Taken together, in Ang II-stimulated VSMCs, kahweol inhibited CTGF-dependent synthetic phenotype switching and migration, with focal adhesion kinase (FAK), Erk, and YAP involved in the underlying mechanisms of the kahweol effects. These results suggest that kahweol has a potential as a therapeutic agent to inhibit CTGF, which is a molecular target in sclerogenic vascular disease.

Receptors for pro-resolving mediators as a therapeutic tool for smooth muscle remodeling-associated disorders

Respiratory airway, blood vessel and intestinal wall remodeling, in which smooth muscle remodeling plays a major role, is a key pathological event underlying the development of several associated diseases, including asthma, cardiovascular disorders (e.g., atherosclerosis, hypertension, and aneurism formation), and inflammatory bowel disease. However, the mechanisms underlying these remodeling processes remain poorly understood. We hypothesize that the creation of chronic inflammation-mediated networks that support and exacerbate the airway, as well as vascular and intestinal wall remodeling, is a crucial pathogenic mechanism governing the development of the associated diseases. The failed inflammation resolution might be one of the causal pathogenic mechanisms. Hence, it is reasonable to assume that applying specialized, pro-resolving mediators (SPMs), acting via cognate G-protein coupled receptors (GPCRs), could potentially be an effective pathway for treating these disorders. However, several obstacles, such as poor understanding of the SPM/receptor signaling pathways, SMP rapid inactivation as well as their complex and costly synthesis, limit their translational potential. In this connection, stable, small-molecule SPM mimetics and receptor agonists have emerged as new, potentially suitable drugs. It has been recently shown in preclinical studies that they can effectively attenuate the manifestations of asthma, atherosclerosis and Crohn's disease. Remarkably, some biased SPM receptor agonists, which cause a signaling response in the desired inflammation pro-resolving direction, revealed similar beneficial effects. These encouraging observations suggest that SPM mimetics and receptor agonists can be applied as a novel approach for the treatment of various chronic inflammation conditions, including airway, vascular and intestinal wall remodeling-associated disorders.