Search Results (59)

Pulmonary hypertension (PH) is a progressive disease that severely compromises right ventricular function, characterized by two major pathological features: pulmonary arterial constriction and pulmonary arterial remodeling. Bellidifolin (BEL), a natural ketone compound, exhibits potent anti-inflammatory and antioxidant effects; however, its role in PH remains unexplored. This study evaluated the impact of BEL on the two pathological processes: pulmonary arterial constriction and pulmonary arterial remodeling. First, the effects of BEL on pulmonary arterial constriction were evaluated using wire myography. The study revealed that BEL (6–96 μmol/L) inhibited the contraction response of intact endothelial and denuded pulmonary arterial rings precontracted with norepinephrine (1 μmol/L) in a concentration-dependent manner. BEL (90 μmol/L) suppressed pulmonary constriction induced by intracellular calcium release and extracellular calcium influx. In cellular experiments, BEL inhibited the proliferation, migration, and phenotypic transformation of pulmonary arterial smooth muscle cells (PASMCs) induced by 10 μmol/L CoCl₂ (72 h), as evidenced by upregulation of the contractile phenotype markers α-SMA and SM22α and downregulation of the synthetic phenotype markers OPN, vimentin, and PCNA. Multi-omics analysis identified Aldh1A1, Mgp, Col4a6, and Igfbp5 as significantly enriched candidates. Among these candidates, Cellular Thermal Shift Assay demonstrated that BEL enhanced the thermal stability of Igfbp5 in PASMCs, suggesting that Igfbp5 may be a potential direct target of BEL. Moreover, KEGG pathway analysis revealed significant enrichment of the PI3K-AKT-mTOR pathway, which is known to be involved in cell proliferation and is regulated by Igfbp5. BEL may inhibit the PI3K-AKT-mTOR pathway by suppressing Igfbp5. The results indicate that BEL may regulate Igfbp5 to inhibit the PI3K-AKT-mTOR pathway, thereby exerting anti-proliferative and inhibitory effects on migration and phenotypic transformation. Full article

Vein graft restenosis is a leading cause of long-term failure after coronary artery bypass grafting (CABG), driven by maladaptive vascular smooth muscle cell (VSMC) responses to arterialization-induced inflammation. The key molecular mediators of this pathological remodeling, however, remain incompletely defined. Here, we integrated multi-omics analyses of human and canine vein graft specimens with in vitro functional assays to identify tenascin-C (TNC)—a matricellular extracellular matrix protein—as a critical regulator of VSMC dysfunction. TNC was specifically enriched in a synthetic, pro-inflammatory VSMC subpopulation. Pro-inflammatory stimuli potently induced TNC expression, which was functionally linked to VSMC phenotypic modulation, hyperproliferation, and enhanced migration. Mechanistically, TNC acts upstream of NF-κB signaling; siRNA-mediated TNC knockdown significantly reduced nuclear p65 protein levels and attenuated inflammatory responses. Our integrated computational and experimental data suggest that TNC, NF-κB, and TNF-α function within a sequential pro-inflammatory signaling cascade that sustains vascular inflammation and promotes neointimal hyperplasia. These findings reposition TNC from a passive structural component to an active driver of vascular pathology and highlight the TNC–NF-κB axis as a candidate target for therapeutic intervention to improve vein graft patency. Full article

Periodontitis is closely linked to atherosclerosis; however, the role of the keystone periodontal pathogen Porphyromonas gingivalis (P. gingivalis), particularly its virulence factor, outer membrane vesicles (OMVs), in vascular smooth muscle cell (VSMC) dysfunction remains unclear. This study aimed to explore the effects of P. g-OMVs on mouse aortic smooth muscle cells (MOVAS) and the potential involvement of cytoskeleton-associated protein 4 (CKAP4) in this process. OMVs were isolated by ultracentrifugation and characterized by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and Western blotting. MOVAS cells were treated with OMVs; cellular functions were evaluated using CCK-8, colony formation, scratch wound-healing, ELISA, and Western blotting assays. Lentiviral vectors were used to construct CKAP4 overexpression and knockout cell models. Results showed that after P. g-OMVs were internalized by MOVAS cells, the cells showed cytoskeletal disorganization, promoting cell proliferation, wound closure, and contractile-to-synthetic phenotypic switching (decreased α-SMA and increased OPN expression), and enhancing extracellular matrix (ECM) remodeling (upregulated expression of type I collagen, type III collagen, fibronectin, matrix metalloproteinase-2 and -9, and tissue inhibitor of metalloproteinase-1). At the protein level, P. g-OMV treatment was associated with upregulated expression of CKAP4, integrin α5, and integrin β1; CKAP4 overexpression synergized with OMV stimulation to amplify these phenotypic alterations, whereas CKAP4 knockout attenuated these cellular changes. These findings suggest an association between CKAP4 upregulation and P. g-OMV-induced MOVAS dysfunction, indicating that CKAP4 may serve as a potential target in periodontitis-associated atherosclerosis. Full article

Vascular remodeling driven by the phenotypic switching of vascular smooth muscle cells (VSMCs) poses a significant health risk to astronauts during long-duration spaceflight. While the morphological and molecular changes are well recognized, the underlying metabolic drivers and potential translational countermeasures remain elusive. To investigate the metabolic determinants of VSMCs phenotypic switching, human aortic smooth muscle cells (HASMCs) were subjected to cyclic mechanical stretch, an in vitro model offering indirect mechanistic insights into mechanical loading conditions relevant to spaceflight-associated hemodynamic alterations. An integrated approach combining quantitative proteomics, flux analysis (Seahorse), and functional assays (cell cycle, wound healing, transwell) was used to characterize the accompanying metabolic and phenotypic alterations. Molecular mechanisms were assessed using immunoprecipitation, protein crosslinking, and immunofluorescence. Mechanical stretch triggered a contractile-to-synthetic phenotypic switch in HASMCs, accompanied by a shift from oxidative phosphorylation to aerobic glycolysis. Pyruvate kinase M2 (PKM2) was identified as a central metabolic regulator of this process, its silencing reversed the pro-synthetic phenotype. Notably, lactate, a glycolytic product, was found to exert a self-limiting feedback signal. Exogenous lactate suppressed the synthetic switch in associated with increased PKM2 lactylation. Further analysis indicated that PKM2 lactylation was associated with enhanced stability of its active tetrameric conformation, which was associated with a metabolic shift toward oxidative phosphorylation and restored expression of contractile markers. Although specific lactylation sites on PKM2 were not identified in this study, and direct causality between lactylation and tetramerization remains to be established, these findings identify a previously unrecognized association. This study reveals a novel metabolic regulatory mechanism in which lactate correlates with the suppression of synthetic switching of VSMCs, linked to PKM2 lactylation and tetramer stabilization. The observed lactate-PKM2 axis represents a candidate metabolic node associated with VSMCs phenotype regulation and offers a potential therapeutic target for modulating vascular remodeling. Upon direct validation under relevant conditions in future studies, this mechanism may inform the development of novel therapeutic strategies for managing vascular adaptation during long-duration spaceflight and other aerospace-related physiological challenges. Full article

Aortic diseases, including thoracic and abdominal aneurysms as well as aortic dissections, represent life-threatening vascular disorders characterized by progressive wall degeneration and inflammation. Increasing evidence indicates that oxidative stress is a central driver of aortic pathology through the induction of DNA damage in vascular smooth muscle cells and endothelial cells. Oxidative DNA lesions activate the DNA damage response (DDR), a highly coordinated network of damage sensors, signaling kinases, and repair effectors that determines cell fate decisions such as DNA repair, apoptosis, or cellular senescence. In aortic tissue, persistent or dysregulated DDR signaling contributes to chronic inflammation, extracellular matrix degradation, and loss of vascular integrity. Key molecular regulators, including base excision repair enzymes OGG1 and APE1, as well as DDR mediators such as ATM, ATR, p53, PARP, and NOTCH1, integrate oxidative stress signals with pro-inflammatory and pro-degenerative pathways. Aberrant activation of these mechanisms promotes vascular smooth muscle cell VSMC phenotypic switching from contractile to synthetic phenotype, endothelial dysfunction, and senescence-associated secretory responses, thereby accelerating aortic wall weakening and aneurysm progression. This review highlights the mechanistic links between oxidative stress-induced DNA damage, DDR pathway activation, and vascular remodeling in aortopathies. A deeper understanding of these molecular interactions may uncover novel biomarkers and therapeutic targets aimed at limiting inflammation, preserving genomic stability, and preventing catastrophic aortic events. This work represents a narrative review and therefore has inherent limitations in terms of systematic literature search and selection. Full article

Vascular smooth muscle cells (VSMCs) in the tunica media are essential for maintaining the structure and function of the arterial wall. These cells regulate vascular tone and contribute to vasculogenesis and angiogenesis, particularly during development. Proper control of VSMC differentiation ensures the correct size and patterning of vessels. Dysregulation of VSMC behaviour in adulthood, however, is linked to serious cardiovascular diseases, including aortic aneurysm, coronary artery disease, atherosclerosis and pulmonary hypertension. VSMCs are characterised by their phenotypic plasticity, which is the capacity to transition from a contractile to a synthetic, dedifferentiated state in response to environmental cues. This phenotypic switch plays a central role in vascular remodelling, a process that drives the progression of many vascular pathologies. Epigenetic mechanisms, which are defined as heritable but reversible changes in gene expression that do not involve alterations to the DNA sequence, have emerged as key regulators of VSMC identity and behaviour. These mechanisms include DNA methylation, histone modifications, chromatin remodelling, non-coding RNA and RNA modifications. Understanding how these epigenetic processes influence VSMC plasticity is crucial to uncovering the molecular basis of vascular development and disease. This review explores the current understanding of VSMC biology, focusing on epigenetic regulation in health and pathology. Full article

Thrombospondin-1 (TSP1) is a multifunctional glycoprotein that plays a crucial role in angiogenesis and vascular remodeling. Ser93 of TSP1 has recently been identified as a novel phosphorylation site, influencing angiogenic properties; however, the underlying signaling mechanism remains unclear. Here, we investigated the functional impact of Ser93 phosphorylation using phosphomimetic (TSP1^S93D) and phosphonull (TSP1^S93A) mutants. Endothelial cell (EC) migration was analyzed using scratch assay and electric cell-substrate impedance sensing. Activation of key pathways (Akt, p38, ERK, and FAK) was analyzed by immunoblotting. TSP1 secretion was quantified by ELISA. Downstream effects on smooth muscle cells were examined by Western blot using conditioned media of endothelial cells. Expression of TSP1^S93D significantly impaired endothelial migration and wound closure, associated with reduced phosphorylation of FAK and paxillin. Upstream of FAK signaling, TSP1^S93D showed enhanced binding to integrin β1 and promoted its clustering. In contrast, TSP1^S93D stimulated smooth muscle cell proliferation, migration, cytoskeletal remodeling, and phenotypic switching toward a synthetic, pro-inflammatory state characterized by elevated marker protein expression. Together, these findings demonstrate that the impaired angiogenic properties induced by TSP1^S93D result from the modulation of integrin β1-FAK pathways in ECs, suppressing endothelial motility while promoting smooth muscle activation, suggesting a role in early vascular remodeling and inflammation. Full article

Pathological vascular remodeling—central to restenosis, atherosclerosis, and vasculo-proliferative diseases—depends on the phenotypic switching of vascular smooth muscle cells (VSMCs) from a quiescent, contractile state to a synthetic, proliferative program. Although the receptor tyrosine kinase c-Kit is implicated in proliferation, migration, and tissue repair, its role in VSMC plasticity has yet to be fully understood. Using c-Kit haploinsufficient mice subjected to right carotid artery ligation (CAL) and primary aortic VSMC cultures, we show that c-Kit is required for the contractile-to-synthetic transition. In vitro, c-Kit haploinsufficiency halved c-Kit expression, reduced 5-bromo-2′-deoxyuridine (BrdU) incorporation, and blunted platelet-derived growth factor BB (PDGF-BB)-induced repression of contractile genes. c-Kit–deficient VSMCs exhibited a senescence program with increased p16^INK4a/p21 expression and upregulated senescence-associated secretory phenotype (SASP) mediators. RNA-Seq of carotid arteries 7 days post-ligation revealed that wild-type arteries activated cell-cycle pathways and suppressed contractile signatures, whereas c-Kit-deficient carotid arteries failed to fully engage proliferative programs and instead maintained contractile gene expression. At 28 days post CAL in vivo, c-Kit haploinsufficiency produced markedly reduced neointima, fewer Ki67+ VSMCs, more p16^INK4a+ cells, and impaired re-endothelialization. Because progenitor-to-VSMC differentiation contributes to remodeling, we tested adult cardiac stem/progenitor cells (CSCs) as a model system of adult progenitor differentiation. Wild-type CSCs efficiently generated induced VSMCs (iVSMCs) with appropriate smooth-muscle gene upregulation; c-Kit–deficient rarely did so. Restoring c-Kit with a BAC transgene rescued both the smooth-muscle differentiation and proliferative competence of c-Kit-deficient iVSMCs. Collectively, our data identified c-Kit as a gatekeeper of reparative VSMC plasticity. Adequate c-Kit enables progenitor-to-VSMC commitment and the expansion of newly formed VSMCs while permitting injury-induced proliferation and matrix synthesis; reduced c-Kit locks cells in a hypercontractile, senescence-prone state and limits neointima formation. Modulating the c-Kit axis may therefore offer a strategy to fine-tune vascular repair while mitigating pathological remodeling. Full article

Mast cells (MCs) belong to the cell network that regulates uterine spiral artery remodeling (uSAR), a critical vascular adaptation supporting placental development and fetal growth. Our previous in vitro study demonstrated that human MCs promote trophoblast invasion, as well as uterine vascular smooth muscle cells (uVSMCs) migration and transition to a synthetic phenotype—essential steps for a successful uSAR. Although MCs are known targets of bisphenol A (BPA), a widespread endocrine-disrupting chemical, its impact on their supportive role in uSAR is unknown. In this study, we used murine cell lines to investigate whether BPA (0.1–100 µM) affects MC-mediated promotion of cellular processes critical for uSAR. Our results showed that BPA exposure hindered MCs’ ability to promote trophoblast invasion and the switch in uVSMCs’ synthetic phenotype and migration. The highest concentrations of BPA altered the expression of genes related to MCs activation and proliferation, and of those involved in trophoblasts invasion. In contrast, low doses induced the expression of pro-inflammatory mediators in MCs without detectable effect on trophoblasts at the transcriptional level. These findings confirmed MCs as key mediators of uSAR, and identified BPA as a disruptor of their function, emphasizing its potential harmful impact on reproductive health. Full article

Vascular smooth muscle cells (VSMCs) are a major cell type in the arterial wall responsible for regulating vascular homeostasis. Under physiological conditions, VSMCs reside in the medial layer of the arteries, express elevated levels of contractile proteins, regulate vascular tone, and provide mechanical strength and elasticity to the blood vessel. In response to obesity, hyperglycemia, and insulin resistance, critical pathogenic hallmarks of Type 2 diabetes (T2D), VSMCs undergo a phenotypic transformation, adopting new phenotypes with increased proliferative (synthetic), inflammatory (macrophage-like), or bone-like (osteogenic) properties. While crucial for normal repair and vascular adaptation, VSMC phenotypic plasticity is a key driver for the development and progression of macrovascular complications associated with T2D. Despite advances in lineage tracing and multi-omics profiling that have uncovered key molecular regulators of VSMC phenotypic switching in vasculopathy, our understanding of the cellular and molecular mechanisms underlying VSMC transformation into diseased phenotypes in T2D remains incomplete. This review will provide a holistic summary of research from the past 15 years, with a focus on the signaling pathways and transcriptional regulators that govern VSMC phenotypic transition in response to obesity, hyperglycemia, and insulin resistance. We examine the integrated molecular mechanisms that orchestrate VSMC fate reprogramming in T2D and highlight the dynamic interplay among diverse signaling and transcriptional networks. Emphasis is placed on how these interconnected pathways collectively influence VSMC behavior and contribute to the pathogenesis of T2D-associated atherosclerosis. Full article

Background: Previously, we found that the pathological changes in the corpus spongiosum (CS) in hypospadias were mainly localized within smooth muscle tissue, presenting as a transformation from the contraction phenotype to synthesis. The role of low-intensity pulsed ultrasound (LIPUS) in regulating smooth muscle cells (SMCs) and angiogenesis has been confirmed. Objectives: To demonstrate the feasibility of regulating the phenotypic transformation of corpus spongiosum smooth muscle cells (CSSMCs) in hypospadias using LIPUS and to explore the potential mechanisms. Materials and Methods: The CSSMCs were extracted from CS in patients with proximal hypospadias. In vitro experiments were conducted to explore the appropriate LIPUS irradiation intensity and duration which could promote the phenotypic transformation of CSSMCs. A total of 71 patients with severe hypospadias were randomly divided into a control group and a LIPUS group to verify the in vivo transition effect of LIPUS. Consequently, the potential mechanisms by which LIPUS regulates the phenotypic transformation of CSSMCs were explored in vitro. Results: In vitro experiments showed that LIPUS with an intensity of 100 mW/cm² and a duration of 10 min could significantly increase the expression of contraction markers in CSSMCs and decrease the expression of synthesis markers. Moreover, LIPUS stimulation could alter the phenotype of CSSMCs in patients with proximal hypospadias. RNA sequencing results revealed that peroxisome proliferator-activated receptor gamma (PPAR-γ) significantly increased after LIPUS stimulation. Overexpression of PPAR-γ significantly increased the expression of contraction markers in CSSMCs, and the knockdown of PPAR-γ blocked this effect. Conclusions: LIPUS can regulate the transition of CSSMCs from a synthetic to a contractile phenotype in hypospadias. The PPAR-γ-mediated signaling pathway is a possible mechanism involved in this process. Full article

Background/Objectives: Under physiological conditions, vascular smooth muscle cells (VSMCs) are in a quiescent contractile state, but under pathological conditions, such as atherosclerosis, they change their phenotype to synthetic, characterized by increased proliferation, migration, and production of an extracellular matrix. Furthermore, VSMCs can undergo calcification, switching to an osteoblast-like phenotype, contributing to plaque instability. Methods: In this study, we analyzed the phenotypic changes in VSMCs during the transition from a physiological to a pathological state, a key process in the progression of atherosclerosis, using confocal and transmission electron microscopy, real-time PCR, and intracellular calcium quantification. Results: Confocal and transmission electron microscopy revealed a prominent remodeling of the actin cytoskeleton, increasing autophagic vacuoles in synthetic VSMCs and the deposition of calcium microcrystals in calcified cells. Immunofluorescence analysis revealed differential expression of α-SMA (contractile marker) and galectin-3 (synthetic marker), confirming the phenotypic changes. Real-time PCR further validated these changes, showing upregulation of RUNX-2, a marker of osteogenic transition, in calcified VSMCs. Conclusions: This study highlights the dynamic plasticity of VSMCs and their role in atherosclerosis progression. Understanding the characteristics of these phenotypic transitions can help develop targeted therapies to mitigate vascular calcification and plaque instability, potentially countering cardiovascular disease. Full article

Vascular smooth muscle cells (VSMCs) can dynamically change their phenotype between contractile and synthetic forms in response to environmental stress, which is pivotal in maintaining vascular homeostasis and mediating pathological remodeling of blood vessels. We previously reported that suppression of canonical transient receptor potential 6 (TRPC6) channel-mediated cation entry sustains VSMCs contractile phenotype and promotes the blood flow recovery after hindlimb ischemia in mice. We also reported that Zn²⁺, a metal biomolecule mobilized by TRPC6 channel activation, exerts potential beneficial effects on cardiac contractility and remodeling. Therefore, we hypothesized that TRPC6-mediated Zn²⁺ influx participates in phenotype switching of VSMCs and vascular remodeling. We established rat aortic smooth muscle cells (RAoSMCs) stably expressing wild type (WT) and Zn²⁺ only impermeable TRPC6 (KYD) mutant. Although the resting phenotypes were similar in both RAoSMCs, pharmacological TRPC6 activation by PPZ2 prevented the transforming growth factor (TGF) β-induced reduction in the intracellular Zn²⁺ amount and contractile differentiation in RAoSMCs (WT), but failed to prevent them in RAoSMCs (KYD). There were no significant differences in TRPC6-dependent cation currents among all RAoSMCs pretreated with or without TGFβ and/or PPZ2, suggesting that TRPC6 channels are functionally expressed in RAoSMCs regardless of their phenotype. Treatment of mice with PPZ2 attenuated the progression of vascular remodeling caused by chronic angiotensin II infusion. These results suggest that Zn²⁺ influx through TRPC6 channels negatively regulates the TGFβ-induced contractile differentiation of VSMCs and the progression of vascular remodeling in rodents. Full article

The role of stress granules (SGs) in pulmonary arterial hypertension (PAH) is unknown. We hypothesized that SG formation contributes to abnormal vascular phenotypes, and cardiac and skeletal muscle dysfunction in PAH. Using the rat Sugen/hypoxia (SU/Hx) model of PAH, we demonstrate the formation of SG puncta and increased expression of SG proteins compared to control animals in lungs, right ventricles, and soleus muscles. Acetazolamide (ACTZ) treatment ameliorated the disease and reduced SG formation in all of these tissues. Primary pulmonary artery smooth muscle cells (PASMCs) from diseased animals had increased SG protein expression and SG number after acute oxidative stress and this was ameliorated by ACTZ. Pharmacologic inhibition of SG formation or genetic ablation of the SG assembly protein (G3BP1) altered the SU/Hx-PASMC phenotype by decreasing proliferation, increasing apoptosis and modulating synthetic and contractile marker expression. In human PAH lungs, we found increased SG puncta in pulmonary arteries compared to control lungs and in human PAH-PASMCs we found increased SGs after acute oxidative stress compared to healthy PASMCs. Genetic ablation of G3BP1 in human PAH-PASMCs resulted in a phenotypic switch to a less synthetic and more contractile phenotype. We conclude that increased SG formation in PASMCs and other tissues may contribute to PAH pathogenesis. Full article

Background: Neonatal rats that receive sucrose during a critical postnatal period (CP, days 12 to 28) develop hypertension by the time they reach adulthood. Inflammation might contribute to changes during this period and could be associated with variations in the vascular smooth muscle (VSMC) phenotype. Objective: We studied changes in inflammatory pathways that could underlie the expression of the secretory phenotype in the VSMC in the thoracic aorta of rats that received sucrose during CP. Methods: We analyzed histological changes in the aorta and the expression of the COX-2, TLR4, iNOS, eNOS, MMP-2 and -9, and β- and α-actin, the quantities of TNF-α, IL-6, and IL-1β using ELISA, and the levels of fatty acids using gas chromatography. Results: The aortic wall presented disorganization, decellularization, and wavy elastic fibers and an increase in the lumen area. The α- and β-actin expressions were decreased, while COX-2, TLR4, TNF-α, and the activity of IL-6 were increased. Oleic acid was increased in CP in comparison to the control group. Conclusions: There is transient hypertension at the end of the CP that is accompanied by inflammation and a change in the phenotype of VSMC to the secretory phenotype. The inflammatory changes could act as epigenetic signals to determine the development of hypertension when animals reach adulthood. Full article