Vascular wall regulator of G-protein signalling-1 (RGS-1) is required for angiotensin II-mediated blood pressure control

Lowering blood pressure by exercise: investigating the effect of sweating

High blood pressure (hypertension), is a common medical condition, affecting millions of people and is associated with significant health risks. Exercise has been suggested to manage hypertension by inducing sweating and the corresponding loss of sodium and water from the body.Thus, a variety of epidemiological and clinical studies have been conducted to investigate the relationship between sweating and exercise-induced blood pressure reduction and its impacts on hypertension. The mechanisms underlying exercise-induced blood pressure reduction are complex and still not fully understood. However, several pathways have been suggested, including the loss of sodium and water through sweat, a decrease in peripheral resistance, and an improvement in endothelial function in the blood vessels. The decrease in sodium and water content in the body associated with sweating may result in a reduction in blood volume and thus a decrease in blood pressure. Moreover, the reduction in peripheral resistance is thought to be mediated by the activation of the nitric oxide synthase pathway and the release of vasodilators such as prostacyclin and bradykinin, which lead to vasodilation and, thus, a reduction in blood pressure. In conclusion, exercise-induced sweating and consequent sodium and water loss appear to be a reliable biological link to the blood pressure-reducing effects of exercise in hypertensive individuals. Additionally, the mechanisms underlying exercise-induced blood pressure reduction are complex and involve several biological pathways in the cardiovascular system. Therefore, understanding the role of sweat production in blood pressure management is important for developing effective exercise interventions to prevent and manage hypertension.

Elucidating key immunological biomarkers and immune microenvironment dynamics in aging-related intracranial aneurysm through integrated multi-omics analysis

BACKGROUND

The exact cause of intracranial aneurysms (IA) is still unclear. However, pro-inflammatory factors are known to contribute to IA progression. The specific changes in the immune microenvironment of IAs remain largely unexplored.

METHODS

This study analyzed single-cell sequencing data from a male mouse model of brain aneurysm, focusing on samples before and after elastase-induced Willis aneurysms. The data helped identify eight distinct cell subpopulations: fibroblasts, macrophages, NK cells, endothelial cells, B cells, granulocytes, and monocytes. The study also involved bulk RNA sequencing of 97 IA samples, utilizing ssGSEA and CIBERSORT algorithms for analysis. Intercellular communication among these cells was inferred to understand the immune dynamics in IA.

RESULTS

The study found that fibroblasts and macrophages are predominant in various disease states of IA. Notably, the onset of IA was marked by a significant increase in fibroblasts and a decrease in macrophages. There was a marked increase in cellular interactions, especially involving macrophages, at the onset of the disease. Through enrichment analysis, 12 potential immunogenic biomarkers were identified. Of these, Rgs1 emerged as a critical molecule in IA formation, confirmed through secondary validation in a single-cell sequencing dataset.

CONCLUSION

This comprehensive analysis of immune cell composition and intercellular communication in IA tissues highlights the significant roles of macrophages and the molecule Rgs1. These findings shed light on the physiological and pathological conditions of IA, offering new insights into its immune microenvironment.

RGS proteins and cardiovascular Angiotensin II Signaling: Novel opportunities for therapeutic targeting

Angiotensin II (AngII), as an octapeptide hormone normally ionized at physiological pH, cannot cross cell membranes and thus, relies on, two (mainly) G protein-coupled receptor (GPCR) types, AT1R and AT2R, to exert its intracellular effects in various organ systems including the cardiovascular one. Although a lot remains to be elucidated about the signaling of the AT2R, AT1R signaling is known to be remarkably versatile, mobilizing a variety of G protein-dependent and independent signal transduction pathways inside cells to produce a biological outcome. Cardiac AT1R signaling leads to hypertrophy, adverse remodeling, fibrosis, while vascular AT1R signaling raises blood pressure via vasoconstriction, but also elicits hypertrophic, vascular growth/proliferation, and pathological remodeling sets of events. In addition, adrenal AT1R is the major physiological stimulus (alongside hyperkalemia) for secretion of aldosterone, a mineralocorticoid hormone that contributes to hypertension, electrolyte abnormalities, and to pathological remodeling of the failing heart. Regulator of G protein Signaling (RGS) proteins, discovered about 25 years ago as GTPase-activating proteins (GAPs) for the Gα subunits of heterotrimeric G proteins, play a central role in silencing G protein signaling from a plethora of GPCRs, including the AngII receptors. Given the importance of AngII and its receptors, but also of several RGS proteins, in cardiovascular homeostasis, the physiological and pathological significance of RGS protein-mediated modulation of cardiovascular AngII signaling comes as no surprise. In the present review, we provide an overview of the current literature on the involvement of RGS proteins in cardiovascular AngII signaling, by discussing their roles in cardiac (cardiomyocyte and cardiofibroblast), vascular (smooth muscle and endothelial cell), and adrenal (medulla and cortex) AngII signaling, separately. Along the way, we also highlight the therapeutic potential of enhancement of, or, in some cases, inhibition of each RGS protein involved in AngII signaling in each one of these cell types.

NCOR1 maintains the homeostasis of vascular smooth muscle cells and protects against aortic aneurysm

Phenotypic modulation of vascular smooth muscle cells (VSMCs) plays critical roles in the pathogenesis of aortic aneurysm (AA). The function of nuclear receptor corepressor1 (NCOR1) in regulation of VSMC phenotype and AA is unclear. Herein, using smooth muscle NCOR1 knockout mice, we demonstrated that smooth muscle NCOR1 deficiency decreased both mRNA and protein levels of contractile genes, impaired stress fibers formation and RhoA pathway activation, reduced synthesis of elastin and collagens, and induced the expression and activity of MMPs, manifesting a switch from contractile to degradative phenotype of VSMCs. NCOR1 modulated VSMC phenotype through 3 different mechanisms. First, NCOR1 deficiency increased acetylated FOXO3a to inhibit the expression of Myocd, which downregulated contractile genes. Second, deletion of NCOR1 derepressed NFAT5 to induce the expression of Rgs1, thus impeding RhoA activation. Third, NCOR1 deficiency increased the expression of Mmp12 and Mmp13 by derepressing ATF3. Finally, a mouse model combined apoE knockout mice with angiotensin II was used to study the role of smooth muscle NCOR1 in the development of AA. The results showed that smooth muscle NCOR1 deficiency increased the incidence of aortic aneurysms and exacerbated medial degeneration in angiotensin II-induced AA mouse model. Collectively, our data illustrated that NCOR1 interacts with FOXO3a, NFAT5, and ATF3 to maintain contractile phenotype of VSMCs and suppress AA development. Manipulation of smooth muscle NCOR1 may be a potential approach for AA treatment.

Weighted Gene Coexpression Network Analysis Identifies Crucial Genes Involved in Coronary Atherosclerotic Heart Disease

Background

Coronary atherosclerotic heart disease (CHD) is a lethal disease with an unstated pathogenic mechanism. Therefore, it is urgent to develop innovative strategies to ameliorate the outcome of CHD patients and explore novel biomarkers connected to the pathogenicity of CHD.

Methods

The weighted gene coexpression network analysis (WGCNA) was carried out on a coronary atherosclerosis dataset GSE90074 to determine the crucial modules and hub genes for their prospective relationship to CHD. After the different modules associated with CHD have been identified, the Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enriched pathway analyses were conducted. The protein-protein interaction (PPI) network was thereafter performed for the critical module using STRING and Cytoscape.

Results

The yellow module was recognized as the most critical module associated with CHD. The enriched pathways in the yellow module included those related to inflammatory response, positive regulation of extracellular signal-regulated kinase1/2 (ERK1/2) cascade, lipid catabolic process, cellular response to oxidative stress, apoptotic pathway, and NF-kappa B pathway. Further CytoHubba analysis revealed the top five hub genes (MMP14, CD28, CaMK4, RGS1, and DDAH1) associated with CHD development.

Conclusions

The current study provides the prognosis, novel hub genes, and signaling pathways for treating coronary atherosclerosis. However, their potential biological roles require deeper investigation.

Pathophysiology of Hypertension: The Mosaic Theory and Beyond

Dr Irvine Page proposed the Mosaic Theory of Hypertension in the 1940s advocating that hypertension is the result of many factors that interact to raise blood pressure and cause end-organ damage. Over the years, Dr Page modified his paradigm, and new concepts regarding oxidative stress, inflammation, genetics, sodium homeostasis, and the microbiome have arisen that allow further refinements of the Mosaic Theory. A constant feature of this approach to understanding hypertension is that the various nodes are interdependent and that these almost certainly vary between experimental models and between individuals with hypertension. This review discusses these new concepts and provides an introduction to other reviews in this compendium of Circulation Research.

The vascular dilatation induced by Hydroxysafflor yellow A (HSYA) on rat mesenteric artery through TRPV4-dependent calcium influx in endothelial cells

ETHNOPHARMACOLOGICAL RELEVANCE

Hydroxysafflor yellow A (HSYA) is the principal constituent of the flowers of Carthamus tinctorius L., a traditional Chinese herbal medicine, which has been used for the treatment of cerebrovascular and cardiovascular diseases due to its property of promoting blood circulation and removing blood stasis. It is dominated in the water extract of Carthamus tinctorius L., which has been used in the clinical treatment for cardiovascular diseases. HSYA exerts a variety of pharmacological efficacy upon the vascular system. However, the underlying mechanisms remain unclear.

AIM OF THE STUDY

To investigate the vascular dilatation effect of HSYA on rat mesenteric artery (MA) and its potential mechanism.

MATERIALS AND METHODS

Adult male Wistar rats were applied to the study. Tension studies were conducted to determine the dilatation activity of HSYA against pre-contracted mesenteric arterial (MA) rings by U 46619 and Phenylephrine (PE). The vascular activities were measured with or without incubation with some selective inhibitors, including L-N(ω)-nitro-L-arginine methyl ester (L-NAME, a nitro oxide synthase inhibitor), HC-067047 (a selective TRPV4 antagonist), BaCl₂ (a Kir channel blocker), and Indomethacin (Indo, a nonselective cyclooxygenase inhibitor), respectively. Immunocytochemistry, Calcium Imaging, NO Production detection, and Western Blot were also employed to further study the underlying mechanism.

RESULTS

HSYA reversed the constriction of MAs induced by U 46619 in a manner of concentration dependency, and the dilatation capability was reversed by L-NAME. This effect was significantly dependent on the intactness of MA endothelium, accompanying an increment of NO production in mesenteric arterial endothelium cells. The increment of NO production was reversed by inhibiting the PKA. Also, the expression of p-eNOS was activated by HSYA shown in Western Blot assays. The cells imaging revealed a significant increase and drop of the influx of Ca²⁺ before and after treatment with HC-067047.

CONCLUSIONS

These findings suggest that HSYA exerts vessel dilation effect on MAs via a TRPV4-dependent influx of Ca²⁺ in endothelium cells, PKA-dependent eNOS phosphorylation and NO production mechanism. The present study indicates that HSYA has the potential to be a future candidate for the treatment of hypertension.

The TGF-β pathway plays a key role in aortic aneurysms

Aortic dissection and aortic aneurysms are currently among the most high-risk cardiovascular diseases due to their rapid onset and high mortality. Although aneurysm research has been extensive, the pathogenesis remains unknown. Studies have found that the TGF-β/Smad pathway and aneurysm formation appear linked. For example, the TGF-β signaling pathway was significantly activated in aneurysm development and aortic dissection. Aneurysms are not, however, mitigated following knockdown of TGF-β signaling pathway-related genes. Incidence and mortality rate of ruptured thoracic aneurysms increase with the down-regulation of the classical TGF-β signaling pathway. In this review, we summarize recent findings and evaluate the differential role of classical and non-classical TGF-β pathways on aortic aneurysm. It is postulated that the TGF-β signaling pathway is necessary to maintain vascular function, but over-activation will promote aneurysms whereas over-inhibition will lead to bypass pathway over-activation and promote aneurysm occurrence.

Regulator of G-protein signaling (RGS) proteins as drug targets: Progress and future potentials

G protein-coupled receptors (GPCRs) play critical roles in regulating processes such as cellular homeostasis, responses to stimuli, and cell signaling. Accordingly, GPCRs have long served as extraordinarily successful drug targets. It is therefore not surprising that the discovery in the mid-1990s of a family of proteins that regulate processes downstream of GPCRs generated great excitement in the field. This finding enhanced the understanding of these critical signaling pathways and provided potentially new targets for pharmacological intervention. These regulators of G-protein signaling (RGS) proteins were viewed by many as nodes downstream of GPCRs that could be targeted with small molecules to tune signaling processes. In this review, we provide a brief overview of the discovery of RGS proteins and of the gradual and continuing discovery of their roles in disease states, focusing particularly on cancer and neurological disorders. We also discuss high-throughput screening efforts that have led to the discovery first of peptide-based and then of small-molecule inhibitors targeting a subset of the RGS proteins. We explore the unique mechanisms of RGS inhibition these chemical tools have revealed and highlight the most up-to-date studies using these tools in animal experiments. Finally, we discuss the future opportunities in the field, as there are clearly more avenues left to be explored and potentials to be realized.

Corn dried distillers grains with solubles (cDDGS) in the diet of pigs change the expression of adipose genes that are potential therapeutic targets in metabolic and cardiovascular diseases

Background

Corn dried distillers grains with solubles (cDDGS) are a byproduct of biofuel and alcohol production. cDDGS have been used in pig feed for many years, because they are readily available and rich in protein, fiber, unsaturated fatty acids and phytosterols. However, feed mixtures too high in cDDGS result in the worsening of backfat quality. We performed RNA-sequencing analysis of backfat from crossbred pigs fed different diets. The diets were isoenergetic but contained different amounts of cDDGS and various sources of fats. The animals were divided into four dietary groups during the two months of experimentation: group I (control (-cDDGS+rapeseed oil)), group II (+cDDGS+rapeseed oil), group III (+cDDGS+beef tallow), and group IV (+cDDGS+coconut oil). The aim of the present experiment was to evaluate changes in the backfat transcriptome of pigs fed isoenergetic diets that differed in cDDGS presence.

Results

Via DESeq2 software, we identified 93 differentially expressed genes (DEGs) between groups I and II, 13 between groups I and III, and 125 between groups I and IV. DEGs identified between group I (-cDDGS+rapeseed oil) and group II (+cDDGS+rapeseed oil) were highly overrepresented in several KEGG pathways: metabolic pathways (FDR < 1.21e-06), oxidative phosphorylation (FDR < 0.00189), fatty acid biosynthesis (FDR < 0.00577), Huntington’s disease (FDR < 0.00577), fatty acid metabolism (FDR < 0.0112), Parkinson’s disease (FDR < 0.0151), non-alcoholic fatty liver disease (NAFLD) (FDR < 0.016), Alzheimer’s disease (FDR < 0.0211) and complement and coagulation cascades (FDR < 0.02).

Conclusions

We observed that the addition of cDDGS positively affects the expression of several genes that have been recently proposed as potential targets for the treatment of obesity, diabetes, cardiovascular disease, and Alzheimer’s disease (e.g., FASN, AACS, ALAS1, HMGCS1, and VSIG4). Thus, our results support the idea of including cDDGS into the diets of companion animals and humans and encourage research into the bioactive ingredients of cDDGS.

Electronic supplementary material

The online version of this article (10.1186/s12864-018-5265-x) contains supplementary material, which is available to authorized users.