Huanglian Jiedu decoction inhibits vascular smooth muscle cell-derived foam cell formation by activating autophagy via suppressing P2RY12.

ETHNOPHARMACOLOGICAL RELEVANCE: Huanglian Jiedu Decoction (HLJDD) is a Chinese medicine with a long history of therapeutic application. It is widely used in treating atherosclerosis (AS) in Chinese medicine theory and clinical practice. However, the mechanism of HLJDD in treating AS remains unclear. AIM OF THE STUDY: To investigate the efficacy and mechanism of HLJDD in treating AS. MATERIALS AND METHODS: AS was induced on high-fat diet-fed ApoE-/- mice, with the aorta pathological changes evaluated with lipid content and plaque progression. In vitro, foam cells were induced by subjecting primary mouse aortic vascular smooth muscle cells (VSMCs) to oxLDL incubation. After HLJDD intervention, VSMCs were assessed with lipid stack, apoptosis, oxidative stress, and the expression of foam cell markers. The effects of P2RY12 were tested by adopting clopidogrel hydrogen sulfate (CDL) in vivo and transfecting P2RY12 over-expressive plasmid in vitro. Autophagy was inhibited by Chloroquine or transfecting siRNA targeting ATG7 (siATG7). The mechanism of HLJDD treating atherosclerosis was explored using network pharmacology and validated with molecular docking and co-immunoprecipitation. RESULTS: HLJDD exhibited a dose-dependent reduction in lipid deposition, collagen loss, and necrosis within plaques. It also reversed lipid accumulation and down-regulated the expression of foam cell markers. P2RY12 inhibition alleviated AS, while P2RY12 overexpression enhanced foam cell formation and blocked the therapeutic effects of HLJDD. Network pharmacological analysis suggested that HLJDD might mediate PI3K/AKT signaling pathway-induced autophagy. P2RY12 overexpression also impaired autophagy. Similarly, inhibiting autophagy counteracted the effect of CDL, exacerbated AS in vivo, and promoted foam cell formation in vitro. However, HLJDD treatment mitigated these detrimental effects by suppressing the PI3K/AKT signaling pathway. Immunofluorescence and molecular docking revealed a high affinity between P2RY12 and PIK3CB, while co-immunoprecipitation assays illustrated their interaction. CONCLUSIONS: HLJDD inhibited AS in vivo and foam cell formation in vitro by restoring P2RY12/PI3K/AKT signaling pathway-suppressed autophagy. This study is the first to reveal an interaction between P2RY12 and PI3K3CB.

Shizukaol C alleviates trimethylamine oxide-induced inflammation through activating Keap1-Nrf2-GSTpi pathway in vascular smooth muscle cell.

BACKGROUND: Cardiovascular disease is one of the main causes of global mortality, and there is an urgent need for effective treatment strategies. Gut microbiota-dependent metabolite trimethylamine-N-oxide (TMAO) promotes the development of cardiovascular diseases, and shizukaol C, a natural sesquiterpene isolated from Chloranthus multistachys with various biological activities, might exhibit beneficial role in preventing TMAO-induced vascular inflammation. PURPOSE: The purpose of this study was to investigate the anti-inflammatory effects and the underlying mechanisms of shizukaol C on TMAO-induced vascular inflammation. METHODS: The effect and underlying mechanism of shizukaol C on TMAO-induced adhesion molecules expression, bone marrow-derived macrophages (BMDM) adhesion to VSMC were evaluated by western blot, cell adhesion assay, co-immunoprecipitation, immunofluorescence assay, and quantitative Real-Time PCR, respectively. To verify the role of shizukaol C in vivo, TMAO-induced vascular inflammation model were established using guidewire-induced injury on mice carotid artery. Changes in the intima area and the expression of GSTpi, VCAM-1, CD68 were examined using haematoxylin-eosin staining, and immunofluorescence assay. RESULTS: Our data demonstrated that shizukaol C significantly suppressed TMAO-induced adhesion molecule expression and the bone marrow-derived macrophages (BMDM) adhesion in vascular smooth muscle cells (VSMC). Mechanically, shizukaol C inhibited TMAO-induced c-Jun N-terminal kinase (JNK)-nuclear factor-kappa B (NF-κB)/p65 activation, and the JNK inhibition was dependent on the shizukaol C-mediated glutathione-S-transferase pi (GSTpi) expression. By further molecular docking and protein-binding analysis, we demonstrated that shizukaol C directly binds to Keap1 to induce Nrf2 nuclear translocation and upregulated GSTpi expression. Consistently, our in vivo experiment showed that shizukaol C elevated the expression level of GSTpi in carotid arteries and alleviates TMAO-induced vascular inflammation. CONCLUSION: Shizukaol C exerts anti-inflammatory effects in TMAO-treated VSMC by targeting Keap1 and activating Nrf2-GSTpi signaling and resultantly inhibits the downstream JNK-NF-κB/p65 activation and VSMC adhesion, and alleviates TMAO-induced vascular inflammation in vivo, suggesting that shizukaol C may be a potential drug for treating TMAO-induced vascular diseases.

Hypomethylation of the LncRNA H19 promoter accelerates osteogenic differentiation of vascular smooth muscle cells by activating the Erk1/2 pathways.

OBJECTIVE: Vascular calcification is a common chronic kidney disease complication. This study aimed to investigate the function of long non-coding RNA (LncRNA) H19 in vascular calcification to explore new therapeutic strategies. METHODS: We induced osteogenic differentiation and calcification of vascular smooth muscle cells (VSMCs) using ß-glycerophosphate. Then, we detected the LncRNA H19 promoter methylation status and Erk1/2 pathways using methylation-specific polymerase chain reaction and western blotting, respectively. RESULTS: Compared with the control group, high phosphorus levels induced VSMC calcification, accompanied by increases in LncRNA H19 and the osteogenic marker Runx2 and reduction of the contractile phenotype marker SM22a. LncRNA H19 knockdown inhibited osteogenic differentiation and calcification of VSMCs. However, the suppressed role of VSMC calcification caused by shRNA H19 was partially reversed by simultaneous activation of the Erk1/2 pathways. Mechanically, we found that the methylation rate of CpG islands in the LncRNA H19 promoter region was significantly lower in the high-phosphorus group, and the hypomethylation state elevated LncRNA H19 levels, which in turn regulated phosphorylated Erk1/2 expression. CONCLUSIONS: LncRNA H19 promoted osteogenic differentiation and calcification of VSMCs by regulating the Erk1/2 pathways. Additionally, hypomethylation of LncRNA H19 promoter CpG islands upregulated LncRNA H19 levels and subsequently activated Erk1/2 phosphorylation.

Gualou-Xiebai herb pair and its active ingredients act against atherosclerosis by suppressing VSMC-derived foam cell formation via regulating P2RY12-mediated lipophagy.

BACKGROUND: Atherosclerosis (AS) is a chronic disease characterized by lipid accumulation in the aortic wall and the formation of foam cells overloaded with large lipids inclusions. Currently, Western medicine is primarily used to improve lipid metabolism disorders and reduce inflammatory reactions to delay AS progression, but these medicines come with serious side effects and drug resistance. Gualou-Xiebai (GLXB) is a renowned herb pair that has been proven effective against AS. However, the potential molecular mechanism through which GLXB exerts the anti-atherosclerotic effects of increasing lipophagy in vascular smooth muscle cells (VSMCs) remains unknown. PURPOSE: This study aims to explore the role of lipophagy and the therapeutic mechanism of GLXB in AS. METHODS: UPLC-Q-TOF-MS for the determination of the main components of GLXB-containing serum. An AS mouse model was established by feeding a high-fat diet (HFD) to ApoE-/- mice for 12 weeks. Ultrasonography monitoring was used to confirm the successful establishment of the AS model. Plaque areas and lipid deposition were evaluated using HE staining and aorta imagingafter GLXB treatment. Immunofluorescence staining and Western blotting were utilized to observe the P2RY12 and lipophagy levels in AS mice. VSMCs were stimulated with oxidized low-density lipoprotein (ox-LDL) to induce foam cell formation. The degree of lipophagy and the related molecular mechanisms were assessed after treating the VSMCs with GLXB-containing serum or si-P2RY12 transfection. The active components of GLXB-containing serum that act on P2RY12 were screened and verified by molecular docking and dual-luciferase reporter assays. RESULTS: Seventeen components of GLXB were identified in rat serum by UPLC-Q-TOF-MS. GLXB significantly reduced lipid deposition in HFD-fed ApoE-/- mice and ox-LDL-induced VSMCs. GLXB strikingly increased lipophagy levels by downregulating P2RY12, p62, and plin2, upregulating LC3Ⅱ protein expression, and increasing the number of autophagosomes. Notably, the lipophagy inhibitor CQ and the P2RY12 receptor agonist ADPß abolished the GLXB-induced increase in lipophagy. Last, we confirmed that albiflorin, apigenin, luteolin, kaempferol, 7,8-dihydroxyflavone, and hesperetin from GLXB significantly inhibited P2RY12. CONCLUSION: GLXB activates lipophagy and inhibits lipid accumulation-associated VSMC-derived foam cell formation through suppressing P2RY12 activation, resulting in anti-atherosclerotic effects. The GLXB components albiflorin, apigenin, luteolin, kaempferol, 7,8-dihydroxyflavone, and hesperetin are the potential active effectors against P2RY12.

Exploring the anti-atherosclerosis mechanism of ginsenoside Rb1 by integrating network pharmacology and experimental verification.

Ginsenoside Rb1 is the major active constituent of ginseng, which is widely used in traditional Chinese medicine for the atherosclerosis treatment by anti-inflammatory, anti-oxidant and reducing lipid accumulation. We explored cellular target and molecular mechanisms of ginsenoside Rb1 based on network pharmacology and in vitro experimental validation. In this study, we predicted 17 potential therapeutic targets for ginsenoside Rb1 with atherosclerosis from public databases. We then used protein-protein interaction network to screen the hub targets. Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway enrichment showed that the effects of ginsenoside Rb1 were meditated through multiple targets and pathways. Next, molecular docking results revealed that in the 10 core targets, CCND1 has the highest binding energy with ginsenoside Rb1. Vascular cell proliferation plays a critical role in atherosclerosis development. However, the effect and direct target of ginsenoside Rb1 in regulating vascular cell proliferation in atherosclerosis remains unclear. Edu straining results indicated that ginsenoside Rb1 inhibited the cell proliferation of endothelial cells, macrophages, and vascular smooth muscle cells. The protein immunoprecipitation (IP) analysis showed that ginsenoside Rb1 inhibited the vascular cell proliferation by suppressing the interaction of CCDN1 and CDK4. These findings systematically reveal that the anti-atherosclerosis mechanism of ginsenoside Rb1 by integrating network pharmacology and experimental validation, which provide evidence to treat atherosclerosis by using ginsenoside Rb1 and targeting CCND1.

Potassium dehydroandrographolide succinate regulates the MyD88/CDH13 signaling pathway to enhance vascular injury-induced pathological vascular remodeling.

Pathological vascular remodeling is a hallmark of various vascular diseases. Previous research has established the significance of andrographolide in maintaining gastric vascular homeostasis and its pivotal role in modulating endothelial barrier dysfunction, which leads to pathological vascular remodeling. Potassium dehydroandrographolide succinate (PDA), a derivative of andrographolide, has been clinically utilized in the treatment of inflammatory diseases precipitated by viral infections. This study investigates the potential of PDA in regulating pathological vascular remodeling. The effect of PDA on vascular remodeling was assessed through the complete ligation of the carotid artery in C57BL/6 mice. Experimental approaches, including rat aortic primary smooth muscle cell culture, flow cytometry, bromodeoxyuridine (BrdU) incorporation assay, Boyden chamber cell migration assay, spheroid sprouting assay, and Matrigel-based tube formation assay, were employed to evaluate the influence of PDA on the proliferation and motility of smooth muscle cells (SMCs). Molecular docking simulations and co-immunoprecipitation assays were conducted to examine protein interactions. The results revealed that PDA exacerbates vascular injury-induced pathological remodeling, as evidenced by enhanced neointima formation. PDA treatment significantly increased the proliferation and migration of SMCs. Further mechanistic studies disclosed that PDA upregulated myeloid differentiation factor 88 (MyD88) expression in SMCs and interacted with T-cadherin (CDH13). This interaction augmented proliferation, migration, and extracellular matrix deposition, culminating in pathological vascular remodeling. Our findings underscore the critical role of PDA in the regulation of pathological vascular remodeling, mediated through the MyD88/CDH13 signaling pathway.

Irisin attenuates vascular remodeling in hypertensive mice induced by Ang II by suppressing Ca2+-dependent endoplasmic reticulum stress in VSMCs.

Vascular remodeling plays a vital role in hypertensive diseases and is an important target for hypertension treatment. Irisin, a newly discovered myokine and adipokine, has been found to have beneficial effects on various cardiovascular diseases. However, the pharmacological effect of irisin in antagonizing hypertension-induced vascular remodeling is not well understood. In the present study, we investigated the protection and mechanisms of irisin against hypertension and vascular remodeling induced by angiotensin II (Ang II). Adult male mice of wild-type, FNDC5 (irisin-precursor) knockout, and FNDC5 overexpression were used to develop hypertension by challenging them with Ang II subcutaneously in the back using a microosmotic pump for 4 weeks. Similar to the attenuation of irisin on Ang II-induced VSMCs remodeling, endogenous FNDC5 ablation exacerbated, and exogenous FNDC5 overexpression alleviated Ang II-induced hypertension and vascular remodeling. Aortic RNA sequencing showed that irisin deficiency exacerbated intracellular calcium imbalance and increased vasoconstriction, which was parallel to the deterioration in both ER calcium dysmetabolism and ER stress. FNDC5 overexpression/exogenous irisin supplementation protected VSMCs from Ang II-induced remodeling by improving endoplasmic reticulum (ER) homeostasis. This improvement includes inhibiting Ca2+ release from the ER and promoting the re-absorption of Ca2+ into the ER, thus relieving Ca2+-dependent ER stress. Furthermore, irisin was confirmed to bind to its receptors, αV/ß5 integrins, to further activate the AMPK pathway and inhibit the p38 pathway, leading to vasoprotection in Ang II-insulted VSMCs. These results indicate that irisin protects against hypertension and vascular remodeling in Ang II-challenged mice by restoring calcium homeostasis and attenuating ER stress in VSMCs via activating AMPK and suppressing p38 signaling.

In vitro Evaluation of the Calcification Inhibitory Properties of Policosanol, Genistein, and Vitamin D (Reduplaxin®) either Alone or in Combination.

INTRODUCTION: The process of vascular calcification has severe clinical consequences in a number of diseases, including diabetes, atherosclerosis, and end-stage renal disease. In the present study, we investigated the effect of policosanol (Poli), genistein (Gen), and vitamin D (VitD) separately and in association to evaluate the possible synergistic action on inorganic phosphate (Pi)-induced calcification of vascular smooth muscle cells (VSMCs). METHODS: Primary human VSMCs were cultured with either growth medium or growth medium supplemented with calcium and phosphorus (calcification medium) in combination with Poli, Gen, and VitD. Alizarin Red staining, mineralization, and the protein expression of RUNX2 and superoxide dismutase-2 (SOD2) were investigated. RESULTS: All three substances tested were effective at reducing osteogenic differentiation of VSMCs in a dose-dependent manner. Poli+Gen, Poli+VitD, Gen+VitD treatment induced a greater inhibition of calcification and RUNX2 expression compared to single compounds treatments. Moreover, the association of Poli+Gen+VitD (Reduplaxin®) was more effective at inhibiting VSMCs mineralization and preventing the increase in RUNX2 expression induced by calcification medium but not modified SOD2 expression. CONCLUSIONS: The association of Pol, Gen, and VitD (Reduplaxin®) has an additive inhibitory effect on the calcification process of VSMCs induced in vitro by a pro-calcifying medium.

Ganglioside GM3 Protects Against Abdominal Aortic Aneurysm by Suppressing Ferroptosis.

BACKGROUND: Abdominal aortic aneurysm (AAA) is a potentially life-threatening vascular condition, but approved medical therapies to prevent AAA progression and rupture are currently lacking. Sphingolipid metabolism disorders are associated with the occurrence and development of AAA. It has been discovered that ganglioside GM3, a sialic acid-containing type of glycosphingolipid, plays a protective role in atherosclerosis, which is an important risk factor for AAA; however, the potential contribution of GM3 to AAA development has not been investigated. METHODS: We performed a metabolomics study to evaluated GM3 level in plasma of human patients with AAA. We profiled GM3 synthase (ST3GAL5) expression in the mouse model of aneurysm and human AAA tissues through Western blotting and immunofluorescence staining. RNA sequencing, affinity purification and mass spectrometry, proteomic analysis, surface plasmon resonance analysis, and functional studies were used to dissect the molecular mechanism of GM3-regulating ferroptosis. We conditionally deleted and overexpressed St3gal5 in smooth muscle cells (SMCs) in vivo to investigate its role in AAA. RESULTS: We found significantly reduced plasma levels of GM3 in human patients with AAA. GM3 content and ST3GAL5 expression were decreased in abdominal aortic vascular SMCs in patients with AAA and an AAA mouse model. RNA sequencing analysis showed that ST3GAL5 silencing in human aortic SMCs induced ferroptosis. We showed that GM3 interacted directly with the extracellular domain of TFR1 (transferrin receptor 1), a cell membrane protein critical for cellular iron uptake, and disrupted its interaction with holo-transferrin. SMC-specific St3gal5 knockout exacerbated iron accumulation at lesion sites and significantly promoted AAA development in mice, whereas GM3 supplementation suppressed lipid peroxidation, reduced iron deposition in aortic vascular SMCs, and markedly decreased AAA incidence. CONCLUSIONS: Together, these results suggest that GM3 dysregulation promotes ferroptosis of vascular SMCs in AAA. Furthermore, GM3 may constitute a new therapeutic target for AAA.

Ultrastructural changes of vascular smooth muscle cells and resistance to vasospasm treatment in femoral arteries of an arteriosclerotic rat model.

The objective of this study was to establish an animal model of arteriosclerosis for assessing vasospasm and to investigate the relationship between arteriosclerosis and vasospasm. Twelve-week-old male Sprague-Dawley rats were fed a diet supplemented with adenine and vitamin D (adenine/vitD). Body weight, blood, and femoral artery histopathology were assessed at 2, 4, and 6 weeks. Change in the femoral artery was examined by transmission electron microscope (TEM). Vasospasm was induced by administering epinephrine extravascularly into the femoral artery and released by the treatment with lidocaine as a vasodilator. During this period, the extravascular diameter and blood flow were measured. The rats in the adenine/vitD group developed renal dysfunction, uremia, hyperphosphatemia, and elevated serum alkaline phosphatase. Histological and TEM analyses of the femoral arteries in the treated rats revealed the degeneration of elastic fibers and extensive calcification of the tunica media and intima. Vascular smooth muscles were degenerated and osteoblasts were developed, resulting in calcified arteriosclerosis. Vasospasm in arteriosclerotic arteries was detected; however, vasodilation as well as an increase in the blood flow was not observed. This study revealed the development of vasospasm in the femoral arteries of the arteriosclerotic rats and, a conventional vasodilator did not release the vasospasm.

Selenium Deficiency Promotes Dilatation of the Aorta by Increasing Expression and Activity of Vascular Smooth Muscle Cell Derived Matrix Metalloproteinase-2.

OBJECTIVE: Selenium (Se) is a key part of the body's oxidation defence system. However, it is unclear whether Se affects the development of aortic aneurysm (AA). An animal experiment was conducted to clarify the role of Se in AA development. METHODS: C57BL/6N male mice were fed with a Se deficient (Se-D, < 0.05 mg/kg), Se adequate (Se-A, 0.2 mg/kg), or Se supplemented (Se-S, 1 mg/kg) diet for 8 weeks. Subsequently, an AA murine model (Se-D, n = 11; Se-A, n = 12; Se-S, n = 15) was established using angiotensin II (Ang II, 1 mg/kg/min) for four weeks plus ß-aminopropionitrile (BAPN, 1 mg/mL) for the first two weeks. Saline replaced Ang II, and BAPN was removed during the modelling process for sham mice (Se-A, n = 9). To determine whether Se deficiency promoted aortic dilation via matrix metalloproteinase-2 (MMP-2), the non-specific MMP inhibitor doxycycline (Dox, 100 mg/kg/day) was given to Se-D AA mice (n = 7) for two weeks. RESULTS: The maximum aortic diameter in Se-D AA model mice was significantly increased compared with Se-A AA model mice. MMP-2 expression and activity in the aortic media of Se-D AA model mice was significantly increased compared with Se-A AA model mice. A large number of vascular smooth muscle cells (VSMCs) were found aggregating in the media of the non-dilated aorta of Se-D AA model mice, which was completely inhibited by Dox. The percentage of VSMCs in aortic media of Se-D AA model mice was significantly higher than in Se-A AA model mice. The maximum aortic diameter and occurrence rate of AA in Se-D AA model mice with Dox were significantly reduced compared with Se-D AA model mice. CONCLUSION: Se deficiency promoted dilatation of the aorta in AA model mice by increasing expression and activity of VSMC derived MMP-2, causing abnormal aggregation and proliferation of VSMCs in aortic media.

Integration of single-nucleus RNA sequencing and network disturbance to elucidate crosstalk between multicomponent drugs and trigeminal ganglia cells in migraine.

ETHNOPHARMACOLOGICAL RELEVANCE: Migraine is caused by hyperactivity of the trigeminovascular system, where trigeminal ganglia (TG) plays an important role. TG is composed of multiple neuronal and non-neuronal cell types, which is related to "neuro-inflammation-vascular" disorder in migraine. Tou Tong Ning capsule (TTNC), a CFDA-approved traditional Chinese medicine for treating migraine, has the characteristics of "multicomponents, multitargets, multipathways". AIM OF THE STUDY: To clarify the mechanism of TTNC and elucidate crosstalk between multicomponent drugs and neuronal and non-neuronal functions and cells in migraine. MATERIALS AND METHODS: We integrated single-nucleus RNA sequencing and a quantitative evaluation algorithm of the disturbance of multitarget drugs on the disease network and explored the specific pathology of migraine and corresponding compounds. A cerebrovascular smooth muscle spasmolytic activity experiment was carried out to verify the results of the bioinformatics analysis. RESULTS: TTNC exhibited its regulation activities in neuronal and non-neuronal aspects based on drugs attack to four subnetworks and cell specific networks, which explored the MoA of TTNC in comprehensive and refined perspectives. Compared to neuronal regulation, TTNC showed more significant attack score on non-neuronal biological function (smooth muscle and vessel). And TTNC compound clusters C1, C6 and C7, targeting non-neuronal function and cells, had larger group area than C10, C4 and C6 for neuronal function and cell, which implied that TTNC may mainly regulate the non-neuronal function, e.g., vessel smooth muscle contraction. Contraction of cerebrovascular smooth muscle of mice ex vivo confirmed the vasodilation activity of TTNC and active compounds from C1, C6, C9 (Emodin, Luteolin and Levistilide A). Literature mining confirmed the vasospasmodolytic activity and neuroprotective effect of TTNC. CONCLUSIONS: The study found that TTNC may primarily alleviate non-neuronal functional disorders in migraine by relaxing cerebral vascular smooth muscle cell spasm to alleviate migraine. Integrating single-nucleus RNA sequencing data and network disturbance tools provides a new strategy for the pharmacological mechanism of multicomponent drugs through cell subtyping.

Trimethylamine N-oxide promotes abdominal aortic aneurysm by inducing vascular inflammation and vascular smooth muscle cell phenotypic switching.

OBJECTIVE: Inflammation and vascular smooth muscle cell (VSMC) phenotypic switching are implicated in the pathogenesis of abdominal aortic aneurysm (AAA). Trimethylamine N-oxide (TMAO) has emerged as a crucial risk factor in cardiovascular diseases, inducing vascular inflammation and calcification. We aimed to evaluate the effect of TMAO on the formation of AAA. APPROACH AND RESULTS: Here, we showed that TMAO was elevated in plasma from AAA patients compared with nonaneurysmal subjects by liquid chromatography‒mass spectrometry (LC‒MS) detection. Functional studies revealed that increased TMAO induced by feeding a choline-supplemented diet promoted Ang II-induced AAA formation. Immunohistochemistry, enzyme-linked immunosorbent assay (ELISA), and Western blot analyses revealed that TMAO induced macrophage infiltration and inflammatory factor release. Conversely, inhibition of TMAO by supplementation with DMB suppressed AAA formation and the inflammatory response. Molecular studies revealed that TMAO regulated VSMC phenotypic switching. Flow cytometry analyses showed that TMAO induces macrophage M1-type polarization. Furthermore, pharmacological intervention experiments suggested that the nuclear factor-κB (NF-κB) signaling pathway was critical for TMAO to trigger AAA formation. CONCLUSIONS: TMAO promotes AAA formation by inducing vascular inflammation and VSMC phenotypic switching through activation of the NF-κB signaling pathway. Thus, TMAO is a prospective therapeutic AAA target.

Navigating the landscape: Prospects and hurdles in targeting vascular smooth muscle cells for atherosclerosis diagnosis and therapy.

Vascular smooth muscle cells (VSMCs) have emerged as pivotal contributors throughout all phases of atherosclerotic plaque development, effectively dispelling prior underestimations of their prevalence and significance. Recent lineage tracing studies have unveiled the clonal nature and remarkable adaptability inherent to VSMCs, thereby illuminating their intricate and multifaceted roles in the context of atherosclerosis. This comprehensive review provides an in-depth exploration of the intricate mechanisms and distinctive characteristics that define VSMCs across various physiological processes, firmly underscoring their paramount importance in shaping the course of atherosclerosis. Furthermore, this review offers a thorough examination of the significant strides made over the past two decades in advancing imaging techniques and therapeutic strategies with a precise focus on targeting VSMCs within atherosclerotic plaques, notably spotlighting meticulously engineered nanoparticles as a promising avenue. We envision the potential of VSMC-targeted nanoparticles, thoughtfully loaded with medications or combination therapies, to effectively mitigate pro-atherogenic VSMC processes. These advancements are poised to contribute significantly to the pivotal objective of modulating VSMC phenotypes and enhancing plaque stability. Moreover, our paper also delves into recent breakthroughs in VSMC-targeted imaging technologies, showcasing their remarkable precision in locating microcalcifications, dynamically monitoring plaque fibrous cap integrity, and assessing the therapeutic efficacy of medical interventions. Lastly, we conscientiously explore the opportunities and challenges inherent in this innovative approach, providing a holistic perspective on the potential of VSMC-targeted strategies in the evolving landscape of atherosclerosis research and treatment.

Hypermethylation of the CTRP9 promoter region promotes Hcy induced VSMC lipid deposition and foam cell formation via negatively regulating ER stress.

To provide a theoretical basis for the prevention and treatment of atherosclerosis (As), the current study aimed to investigate the mechanism underlying the effect of homocysteine (Hcy) on inducing the lipid deposition and foam cell formation of the vascular smooth muscle cell (VSMC) via C1q/Tumor necrosis factor-related protein9 (CTRP9) promoter region Hypermethylation negative regulating endoplasmic reticulum stress (ERs). Therefore, apolipoprotein E deficient (ApoE-/-) mice were randomly divided into the control [ApoE-/- + normal diet (NC)] and high methionine [ApoE-/- + (normal diet supplemented with 1.7% methionine (HMD)] groups (n = 6 mice/group). Following feeding for 15 weeks, the serum levels of Homocysteine (Hcy), total cholesterol (TC), and triglyceride (TG) were measured using an automatic biochemical analyzer. HE and oil red O staining were performed on the aorta roots to observe the pathological changes. Additionally, immunofluorescence staining was performed to detect the protein expression levels of CTRP9, glucose-regulated protein 78 kD (GRP78), phosphorylated protein kinase RNA-like ER kinase (p-PERK), activating transcription factor 6a (ATF6a), phosphorylated inositol-requiring enzyme-1α (p-IRE1α), sterol regulatory element binding proteins-1c (SREBP1c) and sterol regulatory element binding proteins-2 (SREBP2) in VSMC derived from murine aortic roots. In vitro, VSMC was stimulated with 100 µmol/l Hcy. After transfection of plasmids with overexpression and interference of CTRP9, ERs agonist (TM) and inhibitor (4-PBA) were given to stimulate VSMC cells. HE staining and oil red O staining were used to observe the effect of Hcy stimulation on lipid deposition in VSMC. Additionally, The mRNA and protein expression levels of CTRP9, GRP78, PERK, ATF6a, IRE1α, SREBP1c, and SREBP2 in VSMC were detected by RT-qPCR and western blot analysis, respectively. Finally, The methylation modification of the CTRP9 promoter region has been studied. The NCBI database was used to search the promoter region of the CTRP9 gene, and CpG Island was used to predict the methylation site. After Hcy stimulation of VSMC, overexpression of DNMT1, and intervention with 5-Azc, assess the methylation level of the CTRP9 promoter through bisulfite sequencing PCR (BSP). The results showed that the serum levels of Hcy, TC, and TG in the ApoE-/- + HMD group were significantly increased compared with the ApoE-/- + NC group. In addition, HE staining and oil red O staining showed obvious AS plaque formation in the vessel wall, and a large amount of fat deposition in VSMC, thus indicating that the hyperhomocysteinemia As an animal model was successfully established. Furthermore, CTRP9 were downregulated, while GRP78, p-PERK, ATF6a, p-IRE1α, SREBP1c, SREBP2 was upregulated in aortic VSMC in the ApoE-/- + HMD group. Consistent with the in vivo results, Hcy can inhibit the expression of CTRP9 in VSMC and induce ERs and lipid deposition in VSMC. Meanwhile, the increased expression of CTRP9 can reduce ERs and protect the lipid deposition in Hcy induced VSMC. Furthermore, ERs can promote Hcy induced VSMC lipid deposition, inhibition of ERs can reduce Hcy induced VSMC lipid deposition, and CTRP9 may play a protective role in Hcy induced VSMC lipid deposition and foam cell transformation through negative regulation of ERs. In addition, The CTRP9 promoter in the Hcy group showed hypermethylation. At the same time as Hcy intervention, overexpression of DNMT1 increases the methylation level of the CTRP9 promoter, while 5-Azc can reduce the methylation level of the CTRP9 promoter. Finally, Hcy can up-regulate the expression of DNMT1 and down-regulate the expression of CTRP9. After overexpression of DNMT1, the expression of CTRP9 is further decreased. After 5-Azc inhibition of DNMT1, the expression of DNMT1 decreases, while the expression of CTRP9 increases. It is suggested that the molecular mechanism of Hcy inhibiting the expression of CTRP9 is related to the hypermethylation of the CTRP9 promoter induced by Hcy and regulated by DNMT1. 5-Azc can inhibit the expression of DNMT1 and reverse the regulatory effect of DNMT1 on CTRP9. Overall, the results of the present study suggested that Hcy induces DNA hypermethylation in the CTRP9 promoter region by up-regulating DNMT1 expression, and negatively regulates ERs mediated VSMC lipid deposition and foam cell formation. CTRP9 may potentially be a therapeutic target in the treatment of hyperhomocysteinemia and As.

Chrysanthemum coronarium L. Extract Attenuates Homocysteine-Induced Vascular Inflammation in Vascular Smooth Muscle Cells.

Hyperhomocysteinemia is a main risk factor for phenotypic modulation of vascular smooth muscle cells (VSMCs) and atherosclerosis. Phenotypic switching and proliferation of VSMCs are related to the progression of vascular inflammation. Chrysanthemum coronarium L. is a leafy vegetable with various biological functions, such as antioxidative, anti-inflammatory, and antiproliferative effects. In this study, we aimed to identify the mechanisms underlying the therapeutic and preventive effects of C. coronarium L. extract (CC) in regulating homocysteine (Hcy)-induced vascular inflammation in human aortic VSMCs. CC did not exhibit cytotoxicity and inhibited Hcy-stimulated VSMC proliferation and migration. In addition, CC promoted Hcy-induced expression of VSMC contractile phenotype proteins, including alpha-smooth muscle actin, calponin, and smooth muscle 22α. CC also decreased Hcy-induced accumulation of reactive oxygen species and expression of inflammatory markers nicotinamide adenine dinucleotide phosphate oxidase-4 and soluble epoxide hydrolase. These results showed that CC attenuates Hcy-induced inflammatory responses, highlighting its potential as a therapeutic or preventive target for Hcy-induced vascular inflammation.

Codonopsis lanceolata Extract Restores Smooth Muscle Vasorelaxation in Rat Carotid Arteries Even under High Extracellular K+ Concentrations.

Recent studies showed that Codonopsis lanceolata (CL) has antihypertensive effects. However, to date, no study has examined the effects of CL on vascular tone under a high extracellular K+ concentration ([K+]o). Thus, the present study examined the effect of an extract of Codonopsis lanceolata (ECL) on the vascular tension of rat carotid arteries exposed to high [K+]o. We used myography to investigate the effect of an ECL on the vascular tension of rat carotid arteries exposed to high [K+]o and the underlying mechanism of action. In arteries with intact endothelia, the ECL (250 µg/mL) had no effect on vascular tension in arteries exposed to normal or high [K+]o. In contrast, the ECL significantly increased vasorelaxation in endothelium-impaired arteries exposed to a physiologically normal or high [K+]o compared with control arteries exposed to the same [K+]o conditions in the absence of ECL. This vasorelaxing action was unaffected by a broad-spectrum K+ channel blocker and an ATP-sensitive K+ channel blocker. The ECL significantly inhibited the vasoconstriction induced by Ca2+ influx through voltage-dependent Ca2+ channels (VDCCs) but not Ca2+ influx induced via receptor-operated Ca2+ channels or the release of Ca2+ from the sarcoplasmic reticulum in the vascular smooth muscle. In summary, our study reveals that the ECL acts through VDCCs in vascular smooth muscle to promote the recovery of vasorelaxation even in arteries exposed to high [K+]o in the context of endothelial dysfunction and provides further evidence of the vascular-protective effects of ECL.

Medicinal plant rosemary relaxes blood vessels by activating vascular smooth muscle KCNQ channels.

The evergreen plant rosemary (Salvia rosmarinus) has been employed medicinally for centuries as a memory aid, analgesic, spasmolytic, vasorelaxant and antihypertensive, with recent preclinical and clinical evidence rationalizing some applications. Voltage-gated potassium (Kv) channels in the KCNQ (Kv7) subfamily are highly influential in the nervous system, muscle and epithelia. KCNQ4 and KCNQ5 regulate vascular smooth muscle excitability and contractility and are implicated as antihypertensive drug targets. Here, we found that rosemary extract potentiates homomeric and heteromeric KCNQ4 and KCNQ5 activity, resulting in membrane hyperpolarization. Two rosemary diterpenes, carnosol and carnosic acid, underlie the effects and, like rosemary, are efficacious KCNQ-dependent vasorelaxants, quantified by myography in rat mesenteric arteries. Sex- and estrous cycle stage-dependence of the vasorelaxation matches sex- and estrous cycle stage-dependent KCNQ expression. The results uncover a molecular mechanism underlying rosemary vasorelaxant effects and identify new chemical spaces for KCNQ-dependent vasorelaxants.

Phosphorus May Induce Phenotypic Transdifferentiation of Vascular Smooth Muscle Cells through the Reduction of microRNA-145.

Phosphorus is a vital element for life found in most foods as a natural component, but it is also one of the most used preservatives added during food processing. High serum phosphorus contributes to develop vascular calcification in chronic kidney disease; however, it is not clear its effect in a population without kidney damage. The objective of this in vivo and in vitro study was to investigate the effect of high phosphorus exposure on the aortic and serum levels of miR-145 and its effect on vascular smooth muscle cell (VSMCs) changes towards less contractile phenotypes. The study was performed in aortas and serum from rats fed standard and high-phosphorus diets, and in VSMCs exposed to different concentrations of phosphorus. In addition, miR-145 silencing and overexpression experiments were carried out. In vivo results showed that in rats with normal renal function fed a high P diet, a significant increase in serum phosphorus was observed which was associated to a significant decrease in the aortic α-actin expression which paralleled the decrease in aortic and serum miR-145 levels, with no changes in the osteogenic markers. In vitro results using VSMCs corroborated the in vivo findings. High phosphorus first reduced miR-145, and afterwards α-actin expression. The miR-145 overexpression significantly increased α-actin expression and partially prevented the increase in calcium content. These results suggest that miR-145 could be an early biomarker of vascular calcification, which could give information about the initiation of the transdifferentiation process in VSMCs.

[Terpinen-4-ol inhibits proliferation of VSMCs exposed to high glucose via regulating KLF4/NF-κB signaling pathway].

This study aimed to observe the effect of terpinen-4-ol(T4O) on the proliferation of vascular smooth muscle cells(VSMCs) exposed to high glucose(HG) and reveal the mechanism via the Krüppel-like factor 4(KLF4)/nuclear factor kappaB(NF-κB) signaling pathway. The VSMCs were first incubated with T4O for 2 h and then cultured with HG for 48 h to establish the model of inflammatory injury. The proliferation, cell cycle, and migration rate of VSMCs were examined by MTT method, flow cytometry, and wound healing assay, respectively. The content of inflammatory cytokines including interleukin(IL)-6 and tumor necrosis factor-alpha(TNF-α) in the supernatant of VSMCs was measured by enzyme-linked immunosorbent assay(ELISA). Western blot was employed to determine the protein levels of proliferating cell nuclear antigen(PCNA), Cyclin D1, KLF4, NF-κB p-p65/NF-κB p65, IL-1ß, and IL-18. The KLF4 expression in VSMCs was silenced by the siRNA technology, and then the effects of T4O on the cell cycle and protein expression of the HG-induced VSMCs were observed. The results showed that different doses of T4O inhibited the HG-induced proliferation and migration of VSMCs, increased the percentage of cells in G_1 phase, and decreased the percentage of cells in S phase, and down-regulated the protein levels of PCNA and Cyclin D1. In addition, T4O reduced the HG-induced secretion and release of the inflammatory cytokines IL-6 and TNF-α and down-regulated the expression of KLF4, NF-κB p-p65/NF-κB p65, IL-1ß, and IL-18. Compared with si-NC+HG, siKLF4+HG increased the percentage of cells in G_1 phase, decreased the percentage of cells in S phase, down-regulated the expression of PCNA, Cyclin D1, and KLF4, and inhibited the activation of NF-κB signaling pathway. Notably, the combination of silencing KLF4 with T4O treatment further promoted the changes in the above indicators. The results indicate that T4O may inhibit the HG-induced proliferation and migration of VSMCs by down-regulating the level of KLF4 and inhibiting the activation of NF-κB signaling pathway.