VSMC-Specific Deletion of FAM3A Attenuated Ang II-Promoted Hypertension and Cardiovascular Hypertrophy

ECSIT-X4 is Required for Preventing Pressure Overload-Induced Cardiac Hypertrophy via Regulating Mitochondrial STAT3

Mitochondrial dysfunction is a key factor in exacerbating pressure overload-induced cardiac hypertrophy and is linked to increased morbidity and mortality. ECSIT, a crucial adaptor for inflammation and mitochondrial function, has been reported to express multiple transcripts in various species and tissues, leading to distinct protein isoforms with diverse subcellular localizations and functions. However, whether an unknown ECSIT isoform exists in cardiac cells and its potential role in regulating mitochondrial function and pathological cardiac hypertrophy has remained unclear. This study identified a 42-kDa ECSIT isoform encoded by the transcript variant Ecsit-X4, which is highly expressed in the mitochondria of adult cardiomyocytes but down-regulated in hypertrophic human heart samples and TAC-treated mouse hearts. AAV9-mediated Ecsit-X4 gene therapy, administered either before or after TAC surgery, significantly attenuated cardiac hypertrophy. Cardiomyocyte-specific Ecsit deficiency worsened TAC-induced cardiac hypertrophy, while Ecsit-X4 compensation independently rescued hypertrophic phenotypes in EcsitcKO mice. Mechanistically, ECSIT-X4 localized to the mitochondria and interacted with STAT3, leading to increased STAT3 levels and enhanced serine 727 phosphorylation in cardiomyocyte mitochondria, thereby promoting strong mitochondrial bioenergetics. This study identified a novel transcript variant of ECSIT localized in the mitochondria of adult cardiomyocytes and highlights its potential as a therapeutic target for heart failure.

VSMC-specific TRPC1 deletion attenuates angiotensin II-induced hypertension and cardiovascular remodeling

Transient receptor potential canonical 1 (TRPC1) channel, a Ca2+-permeable ion channel widely expressed in vasculature, has been reported to be involved in various cardiovascular disorders. However, the pathophysiological function of vascular smooth muscle cell (VSMC)-derived TRPC1 in hypertension and hypertensive cardiovascular remodeling remains to be defined. In this study, we found increased TRPC1 expression in both angiotensin II (AngII)-treated VSMCs and aortas from AngII-infused mice. VSMC-specific TRPC1 deficiency strikingly attenuated AngII-induced vasoconstriction, hypertension, vascular remodeling, and cardiac hypertrophy. Mechanistically, AngII activated enhancer of zeste homolog 2 (EZH2) to stimulate TRPC1 expression, induced calcium influx and phosphorylation of mitogen-activated protein kinase/extracellular signal-regulated kinase (MEK-ERK), which in turn triggered VSMC proliferation and migration and exacerbated hypertension and cardiovascular remodeling. Treatment with EZH2 inhibitor reduced VSMC proliferation and migration and alleviated vasoconstriction and hypertension in AngII-infused mice. Together, we revealed the pathogenic role of the EZH2-TRPC1-MEK/ERK pathway in AngII-induced hypertension and cardiovascular damage. TRPC1 or EZH2 inhibition may represent a desirable therapeutic target for the treatment of hypertension. KEY MESSAGES: AngII activates AT1R-EZH2-TRPC1 pathway in VSMCs and aortas of hypertensive mice. TRPC1 promotes VSMC proliferation and migration via MEK/ERK signaling. Inhibition of TRPC1 or EZH2 alleviates hypertension and cardiovascular remodeling.

Maternal high glucose and fat diet exposure impaired vascular constriction via miR-325-3P/SHIP2/NOX2 pathway axis in offspring vessels

BACKGROUND AND OBJECTIVES

Maternal western-style diets that are high in glucose and fat have well-known cardiovascular effects on offspring, yet the combined influence of such diets during pregnancy is relatively less comprehended. This study investigates the impact of maternal high glucose and fat diet (HGF) on vascular constriction in offspring and the underlying mechanisms.

METHODS AND RESULTS

Pregnant Sprague-Dawley rats were provided with either HGF or control diets. The assessment of fetal and postnatal vascular function disclosed an enhanced sensitivity to angiotensin II-induced vascular constriction in the offspring exposed to HGF. This was ascribed to increased oxidative stress via upregulated NOX2 expression, which was due to downregulated SHIP2 expression that was influenced by upregulated miR-325-3p. The maternal HGF diet elevated miR-325-3p, suppressed SHIP2 and enhanced NOX2 expression in fetal vascular tissues, thereby resulting in vascular dysfunction. These alterations persist into adulthood, heightening the risk of vascular diseases.

CONCLUSION

The present study is the first to demonstrate that maternal HGF diet impairs vascular constriction function in offspring through the miR-325-3p/SHIP2/NOX2 pathway. These novel findings indicate that the detrimental effects of maternal HGF diet on fetal vascular function can persist into adulthood, advancing our knowledge on the impact of maternal diet on offspring vascular health and the early stages of fetal-origin vascular diseases.

Crystal structure combined with metabolomics and biochemical studies indicates that FAM3A participates in fatty acid beta-oxidation upon binding of acyl-L-carnitine

As the first member of the family with sequence similarity 3 (FAM3), FAM3A promotes synthesis of ATP in mitochondria of hepatic cells and cells from other organs. Dysregulations of FAM3A are involved in the development of diabetes and nonalcoholic fatty liver disease (NAFLD). So far, the molecule mechanism under the physiological and pathological functions of FAM3A is largely unexplored. Here, we determined the crystal structure of FAM3A at high resolution of 1.38Å, complexed with an unknown-source compound which was characterized through metabolomics and confirmed as methacholine by thermal shift assay and surface plasmon resonance (SPR). Exploration for natural ligands of FAM3A was conducted through the same molecular interaction assays. The observed binding of acyl-L-carnitine molecules indicated FAM3A participating in fatty acid beta-oxidation. Knockdown and rescue assays coupled with fatty acid oxidation determination confirmed the role of FAM3A in beta-oxidation. This investigation reveals the molecular mechanism for the biological function of FAM3A and would provide basis for identifying drug target for treatment of diabetes and NAFLD.

ZFP36 Regulates Vascular Smooth Muscle Contraction and Maintains Blood Pressure

Hypertension remains a major risk factor for cardiovascular diseases, but the underlying mechanisms are not well understood. Zinc finger protein 36 (ZFP36) is an RNA-binding protein that regulates mRNA stability by binding to adenylate-uridylate-rich elements in the mRNA 3'-untranslated region. This study reveals that ZFP36 expression is highly elevated in the arteries of hypertensive patients and rodents. In cultured vascular smooth muscle cell (VSMC), angiotensin II (AngII) activates poly (ADP-ribose) polymerases1 (PARP1) to stimulate Zfp36 expression at the transcriptional level. VSMC-specific ZFP36 deletion reduces vessel contractility and blood pressure levels in mice. Mechanistically, ZFP36 regulates G protein-coupled receptors (GPCRs)-mediated increases in intracellular calcium levels through impairing the mRNA stability of regulator of G protein signaling 2 (RGS2). Moreover, the VSMC-specific ZFP36 deficiency attenuates AngII-induced hypertension and vascular remodeling in mice. AAV-mediated ZFP36 knockdown ameliorates spontaneous hypertension in rats. These findings elucidate that ZFP36 plays an important role in the regulation of smooth muscle contraction and blood pressure through modulating RGS2 expression. ZFP36 inhibition may represent a new therapeutic strategy for the treatment of hypertension.

The perspective of ceRNA regulation of circadian rhythm on choroidal neovascularization

Abnormal growth of blood vessels (choroidal neovascularization) can lead to age-related macular degeneration (AMD) and eventually cause vision loss due to detachment of the retinal pigmented epithelium. This indicates that choroidal neovascularization is important for the treatment of AMD. The circadian clock in the mammalian retina is responsible for controlling various functions of the retina, enabling it to adjust to changes in light and darkness. Recent studies have revealed a potential connection between the circadian clock and eye diseases, although a cause-and-effect relationship has not been definitively established. C57BL/6J male mice (aged 6 weeks) were randomly divided into two groups (Control group: 9:00-21:00 light period (300 lx); Jet lag group: 8-hour phase advance once every 4 days). A laser-induced CNV model was created after 2 weeks of feeding in a controlled or jet-lagged environment. Then, full transcriptome sequencing was performed. The pathways regulated by differentially expressed mRNAs were identified by GO analysis and GSEA. Further protein networks were constructed with the STRING database and Cytoscape software. WGCNA was used to further explore the co-expression modules of these differential genes and the correlation between these differential genes and phenotypes. ceRNA networks were constructed with miRanda and TargetScan. The pathways associated with the overlapping differentially expressed mRNAs in the ceRNA network were identified, and the hub genes were validated by qPCR. A total of 661 important DEGs, 31 differentially expressed miRNAs, 106 differentially expressed lncRNAs and 87 differentially expressed circRNAs were identified. GO and GSEA showed that the upregulated DEGs were mainly involved in reproductive structure development and reproductive system development. The STRING database and Cytoscape were used to determine the protein interaction relationships of these DEGs. WGCNA divided the expression of these genes into several modules and screened the hub genes of each module separately. Furthermore, a ceRNA network was constructed. GO analysis and GSEA showed that these target DEmRNAs mainly function in wound healing, cell spreading, epiboly involved in wound healing, epiboly, and morphogenesis of an epithelial sheet. Finally, ten key genes were identified, and their expression patterns were confirmed by real-time qPCR. In this study, we investigated the regulatory mechanism of ceRNAs in choroidal neovascularization according to different light-dark cycles in the eyeball.

Blocking Sigmar1 exacerbates methamphetamine-induced hypertension

AIM

Methamphetamine (METH) chronic exposure is an important risk factor for hypertension development. However, the mechanisms behind METH-induced hypertension remain unclear. Therefore, we aimed to reveal the potential mechanisms underlying METH-induced hypertension.

METHODS AND RESULTS

We structured the mouse hypertension model by METH, and observed that METH-treated mice have presented vascular remodeling (large-and small-size arteries) with collagen deposit around the vessel and increasing blood pressure (BP) and Sigma1 receptor (Sigmar1) in vascular tissue. We hypothesized that Sigmar1 is crucial in METH-induced hypertension and vascular remodeling. Sigmar1 knockout (KO) mice and antagonist (BD1047) pretreated mice exposed to METH for six-week showed higher BP and more collagen deposited around vessels than wild-type (WT) mice exposed to METH for six-week, in contrast, mice pretreated with Sigmar1 agonist (PRE-084) had unchanged BP and perivascular collagen despite the six-week METH exposure. Furthermore, we found that METH exposure induced vascular smooth muscle cells (VSMCs) and mesenchymal stem cells to differentiate into the myofibroblast-like cell and secrete collagen into surrounding vessels. Mechanically, Sigmar1 can suppress the COL1A1 expression by blocking the classical fibrotic TGF-β/Smad2/3 signaling pathway in METH-exposed VSMCs and mesenchymal stem cells.

CONCLUSION

Our results suggest that Sigmar1 is involved in METH-induced hypertension and vascular fibrosis by blocking the activation of the TGF-β/Smad2/3 signaling pathway. Accordingly, Sigmar1 may be a novel therapeutic target for METH-induced hypertension and vascular fibrosis.

Regulation of transcription factor function by purinergic signalling in cardiovascular diseases

Cardiovascular diseases (CVDs), including hypertension, atherosclerosis, myocardial ischemia, and myocardial infarction, constitute the primary cause of mortality worldwide. Transcription factors play critical roles in the development of CVDs and contribute to the pathophysiology of these diseases by coordinating the transcription of many genes involved in inflammation, oxidative stress, angiogenesis, and glycolytic metabolism. One important regulator of hemostasis in both healthy and pathological settings has been identified as a purinergic signalling pathway. Research has demonstrated that several signalling networks implicated in the pathophysiology of CVDs are formed by transcription factors that are regulated by purinergic substances. Here, we briefly summarize the roles and mechanisms of the transcription factors regulated by purinergic pathways in various types of CVD. This information will be essential for discovering novel approaches for CVD treatment and prevention.

FAM3A plays a key role in protecting against tubular cell pyroptosis and acute kidney injury

Acute kidney injury (AKI) is in high prevalence worldwide but with no therapeutic strategies. Programmed cell death in tubular epithelial cells has been reported to accelerate a variety of AKI, but the major pathways and underlying mechanisms are not defined. Herein, we identified that pyroptosis was responsible for AKI progression and related to ATP depletion in renal tubular cells. We found that FAM3A, a mitochondrial protein that assists ATP synthesis, was decreased and negatively correlated with tubular cell injury and pyroptosis in both mice and patients with AKI. Knockout of FAM3A worsened kidney function decline, increased macrophage and neutrophil cell infiltration, and facilitated tubular cell pyroptosis in ischemia/reperfusion injury model. Conversely, FAM3A overexpression alleviated tubular cell pyroptosis, and inhibited kidney injury in ischemic AKI. Mechanistically, FAM3A promoted PI3K/AKT/NRF2 signaling, thus blocking mitochondrial reactive oxygen species (mt-ROS) accumulation. NLRP3 inflammasome sensed the overload of mt-ROS and then activated Caspase-1, which cleaved GSDMD, pro-IL-1β, and pro-IL-18 into their mature forms to mediate pyroptosis. Of interest, NRF2 activator alleviated the pro-pyroptotic effects of FAM3A depletion, whereas the deletion of NRF2 blocked the anti-pyroptotic function of FAM3A. Thus, our study provides new mechanisms for AKI progression and demonstrates that FAM3A is a potential therapeutic target for treating AKI.

PANX1-mediated ATP release confers FAM3A's suppression effects on hepatic gluconeogenesis and lipogenesis

BACKGROUND

Extracellular adenosine triphosphate (ATP) is an important signal molecule. In previous studies, intensive research had revealed the crucial roles of family with sequence similarity 3 member A (FAM3A) in controlling hepatic glucolipid metabolism, islet β cell function, adipocyte differentiation, blood pressure, and other biological and pathophysiological processes. Although mitochondrial protein FAM3A plays crucial roles in the regulation of glucolipid metabolism via stimulating ATP release to activate P2 receptor pathways, its mechanism in promoting ATP release in hepatocytes remains unrevealed.

METHODS

db/db, high-fat diet (HFD)-fed, and global pannexin 1 (PANX1) knockout mice, as well as liver sections of individuals, were used in this study. Adenoviruses and adeno-associated viruses were utilized for in vivo gene overexpression or inhibition. To evaluate the metabolic status in mice, oral glucose tolerance test (OGTT), pyruvate tolerance test (PTT), insulin tolerance test (ITT), and magnetic resonance imaging (MRI) were conducted. Protein-protein interactions were determined by coimmunoprecipitation with mass spectrometry (MS) assays.

RESULTS

In livers of individuals and mice with steatosis, the expression of ATP-permeable channel PANX1 was increased (P < 0.01). Hepatic PANX1 overexpression ameliorated the dysregulated glucolipid metabolism in obese mice. Mice with hepatic PANX1 knockdown or global PANX1 knockout exhibited disturbed glucolipid metabolism. Restoration of hepatic PANX1 rescued the metabolic disorders of PANX1-deficient mice (P < 0.05). Mechanistically, ATP release is mediated by the PANX1-activated protein kinase B-forkhead box protein O1 (Akt-FOXO1) pathway to inhibit gluconeogenesis via P2Y receptors in hepatocytes. PANX1-mediated ATP release also activated calmodulin (CaM) (P < 0.01), which interacted with c-Jun N-terminal kinase (JNK) to inhibit its activity, thereby deactivating the transcription factor activator protein-1 (AP1) and repressing fatty acid synthase (FAS) expression and lipid synthesis (P < 0.05). FAM3A stimulated the expression of PANX1 via heat shock factor 1 (HSF1) in hepatocytes (P < 0.05). Notably, FAM3A overexpression failed to promote ATP release, inhibit the expression of gluconeogenic and lipogenic genes, and suppress gluconeogenesis and lipid deposition in PANX1-deficient hepatocytes and livers.

CONCLUSIONS

PANX1-mediated release of ATP plays a crucial role in maintaining hepatic glucolipid homeostasis, and it confers FAM3A's suppressive effects on hepatic gluconeogenesis and lipogenesis.

Dietary branched-chain amino acids intake and new-onset hypertension: a nationwide prospective cohort study in China

OBJECTIVE

This study aimed to investigate the relationship between dietary branched-chain amino acids (BCAAs) and the risk of developing hypertension.

METHODS

A cohort study of 14,883 Chinese adults without hypertension at baseline with were followed for an average of 8.9 years. Dietary intakes of BCAAs, including Ile, Leu, and Val, were collected using 3-day 24-h meal recall and household condiment weighing. Cox proportional hazards regression, restricted cubic splines, interaction analysis, and sensitivity analysis were used to assess the relationship between dietary BCAAs and risk of developing self-reported hypertension, adjusting for age, gender, region, body mass index (BMI), smoking and drinking status, physical activity, energy intake, salt intake.

RESULTS

Among 14,883 study subjects, 6386(42.9%) subjects aged ≥ 45 years at baseline, 2692 (18.1%) had new-onset hypertension during the study period, with a median age of 56 years. High levels of dietary BCAAs were associated with an increased risk of new-onset hypertension. Compared with the 41st-60th percentile, multivariable adjusted hazard ratio (HR) for new-onset hypertension was 1.16 (95% CI 1.01-1.32) for dietary BCAAs 61st-80th percentiles, 1.30 (1.13-1.50) for 81st-95th, 1.60 (1.32-1.95) for 96th-100th. The cut-off value of new-onset hypertension risk, total BCAAs, Ile, Leu, and Val were 15.7 g/day, 4.1 g/day, 6.9 g/day, 4.6 g/day, respectively, and the proportion of the population above these intake values were 13.9%, 13.1%, 15.4%, and 14.4%, respectively. Age, BMI, and salt intake had an interactive effect on this relationship (P < 0.001).

CONCLUSION

There was a significant positive association between total dietary BCAAs, Ile, Leu, Val intake and the risk of developing hypertension, after adjustment for confounders. This relationship was influenced by age, BMI, and salt intake. Further research is needed to clarify the mechanism and potential role of BCAAs in the pathogenesis of hypertension.

FAM3A Deficiency - Induced Mitochondrial Dysfunction Underlies Post-Infarct Mortality and Heart Failure

Mitochondrial protein sequence similarity 3 gene family member A (FAM3A) plays important roles in the electron transfer chain, while its functions in the heart are still unknown. This study aims to explore the roles and mechanisms of FAM3A after myocardial infarction (MI). FAM3A-deficient (Fam3a-/-) mice were implemented with MI injury and showed lower survival rates at 4 weeks as well as decreased cardiac systolic function. Isolated cardiomyocytes of Fam3a-/- mice showed reduced basal, ATP-linked respiration and respiratory reserve compared to that of wild-type mice. Transmission electron microscopy studies showed Fam3a-/- mice had a larger size and elevated density of mitochondria. FAM3A deficiency also induced elevated mitochondrial Ca2+, higher opening level of mPTP, lower mitochondrial membrane potential and elevated apoptotic rates. Further analyses demonstrated that mitochondrial dynamics protein Opa1 contributed to the effects of FAM3A in cardiomyocytes. Our study discloses the important roles of mitochondrial protein FAM3A in the heart.

Comparative Analysis of Circular RNAs Expression and Function between Aortic and Intracranial Aneurysms

An aneurysm is an abnormal enlargement or bulging of the wall of a blood vessel. Most often, aneurysms occur in large blood vessels - the aorta (Thoracic Aortic Aneurysm (TAA) and Abdominal Aortic Aneurysm (AAA)) and brain vessels (Intracranial Aneurysm (IA)). Despite the presence of significant differences in the pathogenesis of the development and progression of IA and TAA/AAA, there are also similarities. For instance, both have been shown to be strongly influenced by shear stress, inflammatory processes, and enzymatic destruction of the elastic lamellae and extracellular matrix (ECM) proteins of the vascular wall. Moreover, although IA and TAA are predominantly considered arteriopathies with different pathological mechanisms, they share risk factors with AAA, such as hypertension and smoking. However, there is a need for a more in- -depth study of the key elements that may influence the formation and progression of a particular aneurysm to find ways of therapeutic intervention or search for a diagnostic tool. Today, it is known that the disruption of gene expression is one of the main mechanisms that contribute to the development of aneurysms. At the same time, growing evidence suggests that aberrant epigenetic regulation of gene function is strongly related to the genesis of aneurysms. Although much has been studied of the known protein-coding genes, circular RNAs (circRNAs), a relatively new and rapidly evolving large family of transcripts, have recently received much scientific attention. CircRNAs regulate gene expression through the sponging of microRNAs (miRNAs) and can also be used as therapeutic targets and biomarkers. Increasing evidence has implicated circRNAs in the pathogenesis of multiple cardiovascular diseases, including the development of aneurysms. However, the mechanism of dysregulation of certain circRNAs in a particular aneurysm remains to be studied. The discovery of circRNAs has recently advanced our understanding of the latest mode of miRNAs/target genes regulation in the development and progression of IA and TAA/AAA. The aim of this study is to compare the expression profiles of circRNAs to search for similar or different effects of certain circRNAs on the formation and progression of IA and TAA/AAA.

Comparison of the antihypertensive effects of folic acid and resveratrol in spontaneously hypertensive rats combined with hyperhomocysteinemia

Objectives

Studies have found that both folic acid and resveratrol have potential benefits in reducing complications of hypertension. The aim of this study was to compare the effects of resveratrol and folic acid on blood pressure in spontaneously hypertensive rats combined with hyperhomocystinemia, and to explore their potential mechanisms.

Methods

Twenty-four male specific pathogen free (SPF) SPF grade spontaneously hypertensive rats were randomly divided into four groups: the SHR group, the hypertension combined with hyperhomocystinemia group (SHR + HHcy), the folic acid intervention group (SHR + HHcy + FA), and the resveratrol intervention group (SHR + HHcy + Res). The rat model of hypertension combined with hyperhomocystinemia was constructed, and then folic acid or resveratrol were given by gavage. Rat tail artery blood pressure, serum homocysteine concentration, superoxide dismutase activity, malondialdehyde levels, and mRNA transcription and protein expression of endothelial nitric oxide synthase and angiotensin II were detected.

Result

Compared with the SHR group, the SHR + HHcy group significantly increased hyperhomocystinemia and malondialdehyde levels, and inhibited superoxide dismutase activity and endothelial nitric oxide synthase expression. Compared with the SHR + HHcy group, the SHR + HHcy + FA group significantly reduced hyperhomocystinemia and malondialdehyde levels, and significantly increased superoxide dismutase activity and endothelial nitric oxide synthase expression; the SHR + HHcy + Res group also inhibited malondialdehyde levels and promoted endothelial nitric oxide synthase expression, but did not reduce hyperhomocystinemia. When comparing between the SHR + HHcy + FA group and the SHR + HHcy + Res group, folic acid significantly decreased hyperhomocystinemia and increased superoxide dismutase activity, while resveratrol significantly decreased blood pressure and angiotensin II expression.

Conclusions

Both resveratrol and folic acid reduced the levels of oxidative stress and promoted the expression of endothelial nitric oxide synthase in SHRs combined with hyperhomocystinemia. Moreover, resveratrol exhibited superior antihypertensive efficacy compared to folic acid, potentially attributed to its ability to inhibit angiotensin II expression.

FAM3A reshapes VSMC fate specification in abdominal aortic aneurysm by regulating KLF4 ubiquitination

Reprogramming of vascular smooth muscle cell (VSMC) differentiation plays an essential role in abdominal aortic aneurysm (AAA). However, the underlying mechanisms are still unclear. We explore the expression of FAM3A, a newly identified metabolic cytokine, and whether and how FAM3A regulates VSMC differentiation in AAA. We discover that FAM3A is decreased in the aortas and plasma in AAA patients and murine models. Overexpression or supplementation of FAM3A significantly attenuate the AAA formation, manifested by maintenance of the well-differentiated VSMC status and inhibition of VSMC transformation toward macrophage-, chondrocyte-, osteogenic-, mesenchymal-, and fibroblast-like cell subpopulations. Importantly, FAM3A induces KLF4 ubiquitination and reduces its phosphorylation and nuclear localization. Here, we report FAM3A as a VSMC fate-shaping regulator in AAA and reveal the underlying mechanism associated with KLF4 ubiquitination and stability, which may lead to the development of strategies based on FAM3A to restore VSMC homeostasis in AAA.

Vascular smooth muscle cells specific deletion of angiopoietin-like protein 8 prevents angiotensin II-promoted hypertension and cardiovascular hypertrophy

AIMS

Angiopoietin-like protein 8 (ANGPTL8) plays important roles in lipid metabolism, glucose metabolism, inflammation, and cell proliferation and migration. Clinical studies have indicated that circulating ANGPTL8 concentrations are increased in patients with hypertension and positively associated with blood pressure. ANGPTL8 deficiency ameliorates blood pressure in mice treated with chronic intermittent hypoxia. Currently, little is known regarding the pathophysiological role of the vascular smooth muscle cell (VSMC)-derived ANGPTL8 in hypertension and hypertensive cardiovascular remodelling.

METHODS AND RESULTS

Circulating ANGPTL8 concentrations, as determined by enzyme-linked immunosorbent assay, were significantly higher in hypertensive patients than in controls (524.51 ± 26.97 vs. 962.92 ± 15.91 pg/mL; P < 0.001). In hypertensive mice [angiotensin II (AngII) treatment for 14 days] and spontaneously hypertensive rats, ANGPTL8 expression was increased and predominantly located in VSMCs. In AngII-treated mice, systolic and diastolic blood pressure in Tagln-Cre-ANGPTL8fl/fl mice were approximately 15-25 mmHg lower than that in ANGPTL8fl/fl mice. AngII-induced vascular remodelling, vascular constriction, and increased expression of cell markers of proliferation (PCNA and Ki67) and migration (MMP-2 and MMP-9) were strikingly attenuated in Tagln-Cre-ANGPTL8fl/fl mice compared with ANGPTL8fl/fl mice. Furthermore, the AngII-induced increase in the heart size, heart weight, heart/body weight ratio, cardiomyocyte cross-sectional area, and collagen deposition was ameliorated in Tagln-Cre-ANGPTL8fl/fl mice compared with ANGPTL8fl/fl mice. In rat artery smooth muscle cells, ANGPTL8-short hairpin RNA decreased intracellular calcium levels and prevented AngII-induced proliferation and migration through the PI3K-Akt pathway, as shown using LY294002 (inhibitor of PI3K) and Akt inhibitor VIII.

CONCLUSION

This study suggests that ANGPTL8 in VSMCs plays an important role in AngII-induced hypertension and associated cardiovascular remodelling. ANGPTL8 may be a novel therapeutic target against pathological hypertension and hypertensive cardiovascular hypertrophy.

FAM3A mediates the phenotypic switch of human aortic smooth muscle cells stimulated with oxidised low-density lipoprotein by influencing the PI3K-AKT pathway

Family with sequence similarity 3 member A (FAM3A) is a multifunctional protein that is related to the pathological process of various disorders. FAM3A is reportedly able to affect the phenotypic change of vascular smooth muscle cells under a hypertensive state. Whether FAM3A mediates the phenotypic switch of vascular smooth muscle cells under an atherosclerotic state remains unaddressed. This work investigated the roles and mechanisms of FAM3A in mediating the phenotypic switch of human aortic smooth muscle cells (HASMCs) stimulated with oxidised low-density lipoprotein (ox-LDL) in vitro. FAM3A expression was elevated in HASMCs following ox-LDL treatment. FAM3A silencing led to a suppressive effect on ox-LDL-provoked proliferation, migration and inflammation of HASMCs, whereas FAM3A overexpression had an opposite effect. Ox-LDL elicited a change in HASMCs from a contractile phenotype to a synthetic phenotype, which was inhibited by FAM3A silencing or enhanced by FAM3A overexpression. Further investigation elucidated that FAM3A silencing repressed and FAM3A overexpression promoted ox-LDL-induced activation of the PI3K-AKT pathway in HASMCs. Reactivation of AKT reversed the suppressive effect of FAM3A silencing on the ox-LDL-induced phenotypic switch of HASMCs. Restraining AKT blocked the promoting effect of FAM3A overexpression on the ox-LDL-induced phenotypic switch of HASMCs. In summary, this work elucidates that FAM3A mediates the ox-LDL-induced phenotypic switch of HASMCs by influencing the PI3K-AKT pathway, indicating a potential role for FAM3A in atherosclerosis.

Nutritional implications in the mechanistic link between the intestinal microbiome, renin-angiotensin system, and the development of obesity and metabolic syndrome

Obesity and metabolic disorders represent a significant global health problem and the gut microbiota plays an important role in modulating systemic homeostasis. Recent evidence shows that microbiota and its signaling pathways may affect the whole metabolism and the Renin-Angiotensin System (RAS), which in turn seems to modify microbiota. The present review aimed to investigate nutritional implications in the mechanistic link between the intestinal microbiome, renin-angiotensin system, and the development of obesity and metabolic syndrome components. A description of metabolic changes was obtained based on relevant scientific literature. The molecular and physiological mechanisms that impact the human microbiome were addressed, including the gut microbiota associated with obesity, diabetes, and hepatic steatosis. The RAS interaction signaling and modulation were analyzed. Strategies including the use of prebiotics, symbiotics, probiotics, and biotechnology may affect the gut microbiota and its impact on human health.

FAM3A maintains metabolic homeostasis by interacting with F1-ATP synthase to regulate the activity and assembly of ATP synthase

Reduced mitochondrial ATP synthase (ATPS) capacity plays crucial roles in the pathogenesis of metabolic disorders. However, there is currently no effective strategy for synchronously stimulating the expressions of ATPS key subunits to restore its assembly. This study determined the roles of mitochondrial protein FAM3A in regulating the activity and assembly of ATPS in hepatocytes. FAM3A is localized in mitochondrial matrix, where it interacts with F1-ATPS to initially activate ATP synthesis and release, and released ATP further activates P2 receptor-Akt-CREB pathway to induce FOXD3 expression. FOXD3 synchronously stimulates the transcriptions of ATPS key subunits and assembly genes to increase its assembly and capacity, augmenting ATP synthesis and inhibiting ROS production. FAM3A, FOXD3 and ATPS expressions were reduced in livers of diabetic mice and NAFLD patients. FOXD3 expression, ATPS capacity and ATP content were reduced in various tissues of FAM3A-deficient mice with dysregulated glucose and lipid metabolism. Hepatic FOXD3 activation increased ATPS assembly to ameliorate dysregulated glucose and lipid metabolism in obese mice. Hepatic FOXD3 inhibition or knockout reduced ATPS capacity to aggravate HFD-induced hyperglycemia and steatosis. In conclusion, FAM3A is an active ATPS component, and regulates its activity and assembly by activating FOXD3. Activating FAM3A-FOXD3 axis represents a viable strategy for restoring ATPS assembly to treat metabolic disorders.

FAM3A Ameliorates Brain Impairment Induced by Hypoxia-Ischemia in Neonatal Rat

Hypoxia-ischemia (HI) during crucial periods of brain formation can lead to changes in brain morphology, propagation of neuronal stimuli, and permanent neurodevelopmental impairment, which can have profound effects on cognitive function later in life. FAM3A, a subgroup of family with sequence similarity 3 (FAM3) gene family, is ubiquitously expressed in almost all cells. Overexpression of FAM3A has been evidenced to reduce hyperglycemia via the PI3K/Akt signaling pathway and protect mitochondrial function in neuronal HT22 cells. This study aims to evaluate the protective role of FAM3A in HI-induced brain impairment. Experimentally, maternal rats underwent uterine artery bilateral ligation to induce neonatal HI on day 14 of gestation. At 6 weeks of age, cognitive development assessments including NSS, wire grip, and water maze were carried out. The animals were then sacrificed to assess cerebral mitochondrial function as well as levels of FAM3A, TNF-α and IFN-γ. Results suggest that HI significantly reduced FAM3A expression in rat brain tissues, and that overexpression of FAM3A through lentiviral transduction effectively improved cognitive and motor functions in HI rats as reflected by improved NSS evaluation, cerebral water content, limb strength, as well as spatial learning and memory. At the molecular level, overexpression of FAM3A was able to promote ATP production, balance mitochondrial membrane potential, and reduce levels of pro-inflammatory cytokines TNF-α and IFN-γ. We conclude that FAM3A overexpression may have a protective effect on neuron morphology, cerebral mitochondrial as well as cognitive function. Created with Biorender.com.

Imipramine activates FAM3A-FOXA2-CPT2 pathway to ameliorate hepatic steatosis

Mitochondrial FAM3A has been revealed to be a viable target for treating diabetes and nonalcoholic fatty liver disease (NAFLD). However, its distinct mechanism in ameliorating hepatic steatosis remained unrevealed. High-throughput RNA sequencing revealed that carnitine palmityl transferase 2 (CPT2), one of the key enzymes for lipid oxidation, is the downstream molecule of FAM3A signaling pathway in hepatocytes. Intensive study demonstrated that FAM3A-induced ATP release activated P2 receptor to promote the translocation of calmodulin (CaM) from cytoplasm into nucleus, where it functioned as a co-activator of forkhead box protein A2 (FOXA2) to promote the transcription of CPT2, increasing free fatty acid oxidation and reducing lipid deposition in hepatocytes. Furthermore, antidepressant imipramine activated FAM3A-ATP-P2 receptor-CaM-FOXA2-CPT2 pathway to reduce lipid deposition in hepatocytes. In FAM3A-deficient hepatocytes, imipramine failed to activate CaM-FOXA2-CPT2 axis to increase lipid oxidation. Imipramine administration significantly ameliorated hepatic steatosis, hyperglycemia and obesity of obese mice mainly by activating FAM3A-ATP-CaM-FOXA2-CPT2 pathway in liver and thermogenesis in brown adipose tissue (BAT). In FAM3A-deficient mice fed on high-fat-diet, imipramine treatment failed to correct the dysregulated lipid and glucose metabolism, and activate thermogenesis in BAT. In conclusion, imipramine activates FAM3A-ATP-CaM-FOXA2-CPT2 pathway to ameliorate steatosis. For depressive patients complicated with metabolic disorders, imipramine may be recommended in priority as antidepressive drug.

Oviductal Glycoprotein 1 Promotes Hypertension by Inducing Vascular Remodeling Through an Interaction With MYH9

BACKGROUND

Hypertension is a common cardiovascular disease that is related to genetic and environmental factors, but its mechanisms remain unclear. DNA methylation, a classic epigenetic modification, not only regulates gene expression but is also susceptible to environmental factors, linking environmental factors to genetic modification. Therefore, globally screening differential genomic DNA methylation in patients with hypertension is important for investigating hypertension mechanisms.

METHODS

Differential genomic DNA methylation in patients with hypertension, individuals with prehypertension, and healthy control individuals was screened using Illumina 450K BeadChip and verified by pyrosequencing. Plasma OVGP1 (oviduct glycoprotein 1) levels were determined using an enzyme-linked immunosorbent assay. Ovgp1 transgenic and knockout mice were generated to analyze the function of OVGP1. The blood pressure levels of the mouse models were measured using the tail-cuff system and radiotelemetry methods. The role of OVGP1 in vascular remodeling was determined by vascular relaxation studies. Protein-protein interactions were investigated using a pull-down/mass spectrometry assay and verified with coimmunoprecipitation and pull-down assays.

RESULTS

We found a hypomethylated site at cg20823859 in the promoter region of OVGP1 and plasma OVGP1 levels were significantly increased in patients with hypertension. This finding indicates that OVGP1 is associated with hypertension. In Ovgp1 transgenic mice, OVGP1 overexpression caused an increase in blood pressure, dysfunctional vasoconstriction and vasodilation, remodeling of arterial walls, and increased vascular superoxide stress and inflammation, and these phenomena were exacerbated by angiotensin II infusion. In contrast, OVGP1 deficiency attenuated angiotensin II-induced vascular oxidase stress, inflammation, and collagen deposition. These findings indicate that OVGP1 is a prohypertensive factor that directly promotes vascular remodeling. Pull-down and coimmunoprecipitation assays showed that MYH9 (nonmuscle myosin heavy chain IIA) interacted with OVGP1, whereas inhibition of MYH9 attenuated OVGP1-induced hypertension and vascular remodeling.

CONCLUSIONS

Hypomethylation at cg20823859 in the promoter region of OVGP1 is associated with hypertension and induces upregulation of OVGP1. The interaction between OVGP1 and MYH9 contributes to vascular remodeling and dysfunction. Therefore, OVGP1 is a prohypertensive factor that promotes vascular remodeling by binding with MYH9.

LncRNA PSR Regulates Vascular Remodeling Through Encoding a Novel Protein Arteridin

RATIONALE

Vascular smooth muscle cells (VSMCs) phenotype switch from contractile to proliferative phenotype is a pathological hallmark in various cardiovascular diseases. Recently, a subset of long noncoding RNAs was identified to produce functional polypeptides. However, the functional impact and regulatory mechanisms of long noncoding RNAs in VSMCs phenotype switching remain to be fully elucidated.

OBJECTIVES

To illustrate the biological function and mechanism of a VSMC-enriched long noncoding RNA and its encoded peptide in VSMC phenotype switching and vascular remodeling.

RESULTS

We identified a VSMC-enriched transcript encoded by a previously uncharacterized gene, which we called phenotype switching regulator (PSR), which was markedly upregulated during vascular remodeling. Although PSR was annotated as a long noncoding RNA, we demonstrated that the lncPSR (PSR transcript) also encoded a protein, which we named arteridin. In VSMCs, both arteridin and lncPSR were necessary and sufficient to induce phenotype switching. Mechanistically, arteridin and lncPSR regulate downstream genes by directly interacting with a transcription factor YBX1 (Y-box binding protein 1) and modulating its nuclear translocation and chromatin targeting. Intriguingly, the PSR transcription was also robustly induced by arteridin. More importantly, the loss of PSR gene or arteridin protein significantly attenuated the vascular remodeling induced by carotid arterial injury. In addition, VSMC-specific inhibition of lncPSR using adeno-associated virus attenuated Ang II (angiotensin II)-induced hypertensive vascular remodeling.

CONCLUSIONS

PSR is a VSMC-enriched gene, and its transcript IncPSR and encoded protein (arteridin) coordinately regulate transcriptional reprogramming through a shared interacting partner, YBX1. This is a previously uncharacterized regulatory circuit in VSMC phenotype switching during vascular remodeling, with lncPSR/arteridin as potential therapeutic targets for the treatment of VSMC phenotype switching-related vascular remodeling.

Exercise-derived peptide protects against pathological cardiac remodeling

Background

Exercise training protects the heart against pathological cardiac remodeling and confers cardioprotection from heart failure. However, the underlying mechanism is still elusive.

Methods

An integrative analysis of multi-omics data of the skeletal muscle in response to exercise is performed to search for potential exerkine. Then, CCDC80tide is examined in humans after acute exercise. The role of CCDC80tide is assessed in a mouse model of hypertensive cardiac remodeling and in hypertension-mediated cell injury models. The transcriptomic analysis and immunoprecipitation assay are conducted to explore the mechanism.

Findings

The coiled-coil domain-containing protein 80 (CCDC80) is found strongly positively associated with exercise. Interestingly, exercise stimuli induce the secretion of C-terminal CCDC80 (referred as CCDC80tide hereafter) via EVs-encapsulated CCDC80tide into the circulation. Importantly, cardiac-specific expression of CCDC80tide protects against angiotensin II (Ang II)-induced cardiac hypertrophy and fibrosis in mice. In in vitro studies, the expression of CCDC80tide reduces Ang II-induced cardiomyocyte hypertrophy, cardiac microvascular endothelial cell (CMEC) inflammation, and mitigated vascular smooth muscle cell (VSMC) proliferation and collagen formation. To understand the cardioprotective effect of CCDC80tide, a transcriptomic analysis reveals a dramatic inhibition of the STAT3 (Signal transducer and activator of transcription 3) signaling pathway in CCDC80tide overexpressing cells. Mechanistically, CCDC80tide selectively interacts with the kinase-active form of JAK2 (Janus kinase 2) and consequently inhibits its kinase activity to phosphorylate and activate STAT3.

Interpretation

The results provide new insights into exercise-afforded cardioprotection in pathological cardiac remodeling and highlight the therapeutic potential of CCDC80tide in heart failure treatment.

Funding

This work was supported by the National Natural Science Foundation of China [Grant/Award Numbers: 81770428, 81830010, 82130012, 81900438, 82100447); Shanghai Science and Technology Committee [Grant/Award Numbers: 21S11903000, 19JC1415702]; Emerging and Advanced Technology Programs of Hospital Development Center of Shanghai [Grant/Award Number: SHDC12018129]; China Postdoctoral Science Foundation [2021M692108]; and China National Postdoctoral Program for Innovative Talents [BX20200211].

ATP Secretion and Metabolism in Regulating Pancreatic Beta Cell Functions and Hepatic Glycolipid Metabolism

Diabetes (DM), especially type 2 diabetes (T2DM) has become one of the major diseases severely threatening public health worldwide. Islet beta cell dysfunctions and peripheral insulin resistance including liver and muscle metabolic disorder play decisive roles in the pathogenesis of T2DM. Particularly, increased hepatic gluconeogenesis due to insulin deficiency or resistance is the central event in the development of fasting hyperglycemia. To maintain or restore the functions of islet beta cells and suppress hepatic gluconeogenesis is crucial for delaying or even stopping the progression of T2DM and diabetic complications. As the key energy outcome of mitochondrial oxidative phosphorylation, adenosine triphosphate (ATP) plays vital roles in the process of almost all the biological activities including metabolic regulation. Cellular adenosine triphosphate participates intracellular energy transfer in all forms of life. Recently, it had also been revealed that ATP can be released by islet beta cells and hepatocytes, and the released ATP and its degraded products including ADP, AMP and adenosine act as important signaling molecules to regulate islet beta cell functions and hepatic glycolipid metabolism via the activation of P2 receptors (ATP receptors). In this review, the latest findings regarding the roles and mechanisms of intracellular and extracellular ATP in regulating islet functions and hepatic glycolipid metabolism would be briefly summarized and discussed.

Berberine: A Review of its Pharmacokinetics Properties and Therapeutic Potentials in Diverse Vascular Diseases

Traditional Chinese medicine plays a significant role in the treatment of various diseases and has attracted increasing attention for clinical applications. Vascular diseases affecting vasculature in the heart, cerebrovascular disease, atherosclerosis, and diabetic complications have compromised quality of life for affected individuals and increase the burden on health care services. Berberine, a naturally occurring isoquinoline alkaloid form Rhizoma coptidis, is widely used in China as a folk medicine for its antibacterial and anti-inflammatory properties. Promisingly, an increasing number of studies have identified several cellular and molecular targets for berberine, indicating its potential as an alternative therapeutic strategy for vascular diseases, as well as providing novel evidence that supports the therapeutic potential of berberine to combat vascular diseases. The purpose of this review is to comprehensively and systematically describe the evidence for berberine as a therapeutic agent in vascular diseases, including its pharmacological effects, molecular mechanisms, and pharmacokinetics. According to data published so far, berberine shows remarkable anti-inflammatory, antioxidant, antiapoptotic, and antiautophagic activity via the regulation of multiple signaling pathways, including AMP-activated protein kinase (AMPK), nuclear factor κB (NF-κB), mitogen-activated protein kinase silent information regulator 1 (SIRT-1), hypoxia-inducible factor 1α (HIF-1α), vascular endothelial growth factor phosphoinositide 3-kinase (PI3K), protein kinase B (Akt), janus kinase 2 (JAK-2), Ca²⁺ channels, and endoplasmic reticulum stress. Moreover, we discuss the existing limitations of berberine in the treatment of vascular diseases, and give corresponding measures. In addition, we propose some research perspectives and challenges, and provide a solid evidence base from which further studies can excavate novel effective drugs from Chinese medicine monomers.

Upregulation of miR-140-5p uncouples mitochondria by targeting Bcl-xL in vascular smooth muscle cells in angiotensin II-induced hypertension

Angiotensin II–induced vascular smooth muscle cell (VSMC) remodeling and dysfunction is a major contributor to the development of hypertension. In spite of the low content of mitochondria and their low contribution to bioenergetics in VSMCs, recent studies have suggested that mitochondria play an important role in the regulation of VSMC function. However, the role of mitochondria in angiotensin II–induced VSMC dysfunction remains unknown. Here, we found that angiotensin II decreased the expression of Bcl-2-like protein 1 (Bcl-xL), a newly identified protein in inhibition of uncoupled proton flux in mitochondria through interaction with the β-subunit of ATP synthase, and uncoupled mitochondria in VSMCs both in vivo and in vitro. Overexpression of Bcl-xL restored the mitochondrial and VSMC function in response to angiotensin II treatment in vitro, suggesting that angiotensin II uncouples mitochondria through downregulation of Bcl-xL. Mechanistically, angiotensin II increased the expression of miR-140-5p, which targeted and downregulated Bcl-xL in VSMCs. Inhibition of miR-140-5p using antagomir-140-5p in vivo attenuated mitochondrial uncoupling and hypertension in angiotensin II-treated mice. These results suggested that upregulation of miR-140-5p uncouples mitochondria by targeting Bcl-xL in VSMCs in angiotensin II–induced hypertension, and miR-140-5p and Bcl-xL are potential targets for treatment of vascular dysfunction.

Chromodomain Helicase DNA Binding Protein 1-like, a negative regulator of Forkhead box O3a, promotes the proliferation and migration of Angiotensin II-induced vascular smooth muscle cells

Essential hypertension (EH) represents a major risk factor for stroke, myocardial infarction, and heart failure. Dysregulated proliferation and migration of vascular smooth muscle cells (VSMCs) play an important role in pathogenesis of EH. This study aims to investigate the effect of Chromodomain Helicase DNA Binding Protein 1-Like (CHD1L) on Angiotensin II (AngII)-induced VSMCs injury and reveal the underlying mechanism. The expression of CHD1L in EH patients was determined by bioinformatics analysis, and then it was silenced in AngII-induced VSMCs to detect the changes in cellular functions including proliferation, migration, invasion and phenotypic switching via CCK-8, EDU staining, wound healing, transwell and Western blot assays, respectively. Inflammation and oxidative stress were also measured by detecting related markers via commercial kits. After confirming the binding sites between forkhead box O3A (FOXO3a) and CHD1L and their negative association by bioinformatics analysis, FOXO3a was further silenced, and the cellular functions were assessed again to reveal the underlying mechanism. Results showed that CHD1L was highly expressed in EH, and interference of CHD1L suppressed the proliferation, migration, invasion and phenotypic switching in VSMCs. Inflammation and oxidative stress were also restrained by CHD1L knockdown. After validating the negative role of FOXO3a in regulating CHD1L, it was found that FOXO3a abrogated the effect of CHD1L knockdown on the cellular functions of AngII-induced VSMCs. In conclusion, FOXO3a suppresses the proliferation and migration of AngII-induced VSMCs by down-regulating CHD1L.

Vascular smooth muscle cell-specific miRNA-214 knockout inhibits angiotensin II-induced hypertension through upregulation of Smad7

Vascular remodeling is a prominent trait during the development of hypertension, attributable to the phenotypic transition of vascular smooth muscle cells (VSMCs). Increasing studies demonstrate that microRNA plays an important role in this process. Here, we surprisingly found that smooth muscle cell-specific miR-214 knockout (miR-214 cKO) significantly alleviates angiotensin II (Ang II)-induced hypertension, which has the same effect as that of miR-214 global knockout mice in response to Ang II stimulation. Under the treatment of Ang II, miR-214 cKO mice exhibit substantially reduced systolic blood pressure. The vascular medial thickness and area in miR-214 cKO blood vessels were obviously reduced, the expression of collagen I and proinflammatory factors were also inhibited. VSMC-specific deletion of miR-214 blunts the response of blood vessels to the stimulation of endothelium-dependent and -independent vasorelaxation and phenylephrine and 5-HT induced vasocontraction. In vitro, Ang II-induced VSMC proliferation, migration, contraction, hypertrophy, and stiffness were all repressed with miR-214 KO in VSMC. To further explore the mechanism of miR-214 in the regulation of the VSMC function, it is very interesting to find that the TGF-β signaling pathway is mostly enriched in miR-214 KO VSMC. Smad7, the potent negative regulator of the TGF-β/Smad pathway, is identified to be the target of miR-214 in VSMC. By which, miR-214 KO sharply enhances Smad7 levels and decreases the phosphorylation of Smad3, and accordingly alleviates the downstream gene expression. Further, Ang II-induced hypertension and vascular dysfunction were reversed by antagomir-214. These results indicate that miR-214 in VSMC established a crosstalk between Ang II-induced AT1R signaling and TGF-β induced TβRI /Smad signaling, by which it exerts a pivotal role in vascular remodeling and hypertension and imply that miR-214 has the potential as a therapeutic target for the treatment of hypertension.

miR‑125a‑5p and miR‑7 inhibits the proliferation, migration and invasion of vascular smooth muscle cell by targeting EGFR

The ectopic proliferation, migration and invasion of vascular smooth muscle cells (VSMCs) contributes to the progression of various human vascular diseases. Accumulating evidence has demonstrated that microRNAs (miRs) exert vital functions in the proliferation and invasion of VSMCs. The current study aimed to elucidate the functions of miR-125a-5p and miR-7 in VSMCs and investigate the associated molecular mechanisms. The results of EdU and reverse transcription-quantitative PCR assays revealed that platelet-derived growth factor (PDGF)-BB enhanced the proliferation of VSMCs and significantly reduced the expression of miR-125a-5p and miR-7. miR-125a-5p or miR-7 overexpression significantly ameliorated PDGF-BB-induced proliferation, migration and invasion of VSMCs. Furthermore, the results demonstrated that epidermal growth factor receptor (EGFR) may be a target mRNA of miR-125a-5p and miR-7 in VSMCs. The results of western blot analysis indicated that co-transfection of miR-125a-5p mimics or miR-7 mimics distinctly decreased the protein expression of EGFR in EGFR-overexpressed VSMCs. Moreover, rescue experiments indicated that EGFR overexpression alleviated the suppressive impact of the miR-125a-5p and miR-7 s on the growth, migration and invasion of VSMCs. In conclusion, the current study identified that miR-125a-5p and miR-7 repressed the growth, migration and invasion of PDGF-BB-stimulated VSMCs by, at least partially, targeting EGFR. The current study verified that miR-125a-5p and miR-7 may be used as feasible therapeutic targets for cardiovascular diseases.

The molecular mechanism of LRP1 in physiological vascular homeostasis and signal transduction pathways

Interactions between vascular smooth muscle cells (VSMCs), endothelial cells (ECs), pericytes (PCs) and macrophages (MФ), the major components of blood vessels, play a crucial role in maintaining vascular structural and functional homeostasis. Low-density lipoprotein (LDL) receptor-related protein-1 (LRP1), a transmembrane receptor protein belonging to the LDL receptor family, plays multifunctional roles in maintaining endocytosis, homeostasis, and signal transduction. Accumulating evidence suggests that LRP1 modulates vascular homeostasis mainly by regulating vasoactive substances and specific intracellular signaling pathways, including the plasminogen activator inhibitor 1 (PAI-1) signaling pathway, platelet-derived growth factor (PDGF) signaling pathway, transforming growth factor-β (TGF-β) signaling pathway and vascular endothelial growth factor (VEGF) signaling pathway. The aim of the present review is to focus on recent advances in the discovery and mechanism of vascular homeostasis regulated by LRP1-dependent signaling pathways. These recent discoveries expand our understanding of the mechanisms controlling LRP1 as a target for studies on vascular complications.

Vascular Stress Signaling in Hypertension

Cells respond to stress by activating a variety of defense signaling pathways, including cell survival and cell death pathways. Although cell survival signaling helps the cell to recover from acute insults, cell death or senescence pathways induced by chronic insults can lead to unresolved pathologies. Arterial hypertension results from chronic physiological maladaptation against various stressors represented by abnormal circulating or local neurohormonal factors, mechanical stress, intracellular accumulation of toxic molecules, and dysfunctional organelles. Hypertension and aging share common mechanisms that mediate or prolong chronic cell stress, such as endoplasmic reticulum stress and accumulation of protein aggregates, oxidative stress, metabolic mitochondrial stress, DNA damage, stress-induced senescence, and proinflammatory processes. This review discusses common adaptive signaling mechanisms against these stresses including unfolded protein responses, antioxidant response element signaling, autophagy, mitophagy, and mitochondrial fission/fusion, STING (signaling effector stimulator of interferon genes)-mediated responses, and activation of pattern recognition receptors. The main molecular mechanisms by which the vasculature copes with hypertensive and aging stressors are presented and recent advancements in stress-adaptive signaling mechanisms as well as potential therapeutic targets are discussed.

Myeloid differentiation protein 2 mediates angiotensin II-induced inflammation and mesenchymal transition in vascular endothelium

Angiotensin II (Ang II)-induced vascular inflammation and injury entails endothelial to mesenchymal transition (EndMT). Recent studies have shown that Ang II engages toll-like receptor 4 (TLR4) in the vasculature to mediate adverse effects. Here, we aimed to investigate whether myeloid differentiation protein 2 (MD2), an extracellular molecule indispensable for TLR4 activation, mediates Ang II-induced vascular injury and EndMT. We utilized MD2 knockout mice and wildtype mice treated with a specific MD2 inhibitor to decipher its role in aortas of Ang II-challenged mice. To confirm our results and to provide mechanistic insights, we exposed cultured endothelial cells to Ang II, with or without MD2 silencing. We show that Ang II causes deleterious remodeling and EndMT in aortas of mice within two weeks. These Ang II effects were largely absent in MD2 knockout mice and in wildtype mice treated with a MD2 inhibitor. MD2 silencing in cultured endothelial cells confirmed the essential role of MD2 in Ang II-induced inflammatory factor induction, and EndMT-associated phenotypic change. We also found that Ang II-MD2-EndMT axis involves the activation of nuclear factor-κB. Our studies highlight an essential role of MD2 in Ang II-induced vascular inflammation and EndMT contributing to vascular injury. These results also imply that MD2 may be targeted to dampen inflammatory cardiovascular and EndMT-associated diseases.

Aloe emodin relieves Ang II-induced endothelial junction dysfunction via promoting ubiquitination mediated NLRP3 inflammasome inactivation

Recent studies have revealed that aloe emodin (AE), a natural compound from the root and rhizome of Rheum palmatum L., exhibits significant pharmacologic activities. However, the pharmacologic relevance of the compound, particularly for cardiovascular disease, remains largely unknown. Here, we hypothesized that AE could improve endothelial junction dysfunction through inhibiting the activation of NOD-like receptor family pyrin domain containing-3 (NLRP3) inflammasome regulated by NLRP3 ubiquitination, and ultimately prevent cardiovascular disease. In vivo, we used confocal microscopy to study the expression of tight junction proteins zonula occludens-1/2 (ZO-1/2) and the formation of NLRP3 inflammasome in coronary arteries of hypertension. And the experimental serum was used to detect the activation of NLRP3 inflammasome by ELISA assay. We found that AE could restore the expression of the endothelial connective proteins ZO-1/2 and decrease the release of high mobility group box1 (HMGB1), and also inhibited the formation and activation of NLRP3 inflammasome. Similarly, in vitro, our findings demonstrated that AE could restore the expression of the tight junction proteins ZO-1/2 and decrease monolayer cell permeability that related to endothelial function after stimulation by angiotensin II (Ang II) in microvascular endothelial cells (MECs). We also demonstrated that AE could inhibit Ang II-induced NLRP3 inflammasome formation and activation, which were regulated by NLRP3 ubiquitination in MECs, as shown by fluorescence confocal microscopy and Western blot. Together with these changes, we revealed a new protection mechanism of AE that inhibited NLRP3 inflammasome activation and decreased the release of HMGB1 by promoting NLRP3 ubiquitination. Our findings implicated that AE exhibited immense potential and specific therapeutic value in hypertension-related cardiovascular disease in the early stage and the development of innovative drugs.