Salt-induced effects on microvascular function: A critical factor in hypertension mediated organ damage

Review Article on Molecular Mechanism of Regulation of Hypertension by Macro-elements (Na, K, Ca and Mg), Micro-elements/Trace Metals (Zn and Cu) and Toxic Elements (Pb and As)

Hypertension (HT) is a medical condition arising due to increase in blood pressure (BP) prevalent worldwide. The balanced dietary intakes of macro-elements and micro-elements including Na, K, Ca, Mg, Zn, and Cu have been described to maintain BP in humans by regulating the osmolarity of blood, cells/tissues, prevention of generation of oxidative and nitrosative stress (OANS), and endothelial damage through their functioning as important components of renin-angiotensin-aldosterone system (RAAS), antioxidant enzyme defense system, and maintenance of blood vascular-endothelial and vascular smooth muscle cell (VSMC) functions. However, inadequate/excess dietary intakes of Na/K, Ca/Mg, and Zn/Cu along with higher Pb and As exposures recognized to induce HT through common mechanisms including the followings: endothelial dysfunctions due to impairment of vasodilatation, increased vasoconstriction and arterial stiffness, blood clotting, inflammation, modification of sympathetic activity and higher catecholamine release, increased peripheral vascular resistance, and cardiac output; increased OANS due to reduced and elevated activities of extracellular superoxide dismutase and NAD(P)H oxidase, less nitric oxide bioavailability, decrease in cGMP and guanylate cyclase activity, increase in intracellular Ca2+ ions in VSMCs, and higher pro-inflammatory cytokines; higher parathyroid and calcitriol hormones; activation/suppression of RAAS resulting imbalance in blood Na+, K+, and water regulated by renin, angiotensin II, and aldosterone through affecting natriuresis/kaliuresis/diuresis; elevation in serum cholesterol and LDL cholesterol, decrease in HDL cholesterol due to defect in lipoprotein metabolism. The present study recommends the need to review simple dietary mineral intervention studies/supplementation trials before keeping their individual dietary excess intakes/exposures in consideration because their interactions lead to elevation and fall of their concentrations in body affecting onset of HT.

Sodium - a systematic review for Nordic Nutrition Recommendations 2023

Blood pressure (BP) rises along with increasing sodium intake from early childhood to late adulthood, and leads to hypertension among most men and women living in Nordic and Baltic countries. Elevated BP is the leading global risk factor for premature deaths and disability-adjusted life-years. A reduction in sodium intake is essential in the prevention of hypertension in individuals, in the lowering of BP levels, in the treatment of hypertensive individuals, and in decreasing risks associated with elevated BP. There is a progressive linear dose-response relationship between sodium intake and BP beginning from a sodium intake of less than 0.8 g/day. Sodium reduction decreases BP linearly by a dose-response manner down to a sodium intake level of less than 2 g/day. Randomised intervention studies with a duration of at least 4 weeks confirm the efficiency and safety of reducing blood sodium intake to a level of less than 2 g/day. Results from prospective cohort studies show that higher sodium intake is positively associated with an increased risk of stroke and cardiovascular events and mortality among the general adult population, and the associations are linear in studies using proper sodium assessment methods. Analyses assessing sodium intake using at least two 24-h urine samples have shown a linear positive relationship between sodium intake and the risk of a cardiovascular event or death. Based on an overall evaluation of the available data, a limitation of the sodium intake to 2.0 g/day is suggested for adults. The optimal sodium intake level would be probably about 1.5 g/day. Sodium intake recommended for children can be extrapolated from the recommended sodium intake for adults. According to national dietary surveys, the average sodium intakes in Nordic countries range in adult men from 3.6 to 4.4 g/day and in adult women from 2.6. to 3.2 g/day, and in Baltic countries in men from 2.6 to 5.1 g/day and in women from 1.8 to 3.6 g/day.

Potassium and Hypertension: A State-of-the-Art Review

Hypertension is the single most important and modifiable risk factor for cardiovascular morbidity and mortality worldwide. Non pharmacologic interventions, in particular dietary modifications have been established to decrease blood pressure (BP) and hypertension related adverse cardiovascular events. Among those dietary modifications, sodium intake restriction dominates guidelines from professional organizations and has garnered the greatest attention from the mainstream media. Despite guidelines and media exhortations, dietary sodium intake globally has not noticeably changed over recent decades. Meanwhile, increasing dietary potassium intake has remained on the sidelines, despite similar BP-lowering effects. New research reveals a potential mechanism of action, with the elucidation of its effect on natriuresis via the potassium switch effect. Additionally, potassium-substituted salt has been shown to not only reduce BP, but also reduce the risk for stroke and cardiovascular mortality. With these data, we argue that the focus on dietary modification should shift from a sodium-focused to a sodium- and potassium-focused approach with an emphasis on intervention strategies which can easily be implemented into clinical practice.

Ghrelin improves endothelial function and reduces blood pressure in Ang II-induced hypertensive mice: Role of AMPK

BACKGROUND

Endothelial dysfunction is a major pathophysiology observed in hypertension. Ghrelin, a key regulator of metabolism, has been shown to play protective roles in cardiovascular system. However, whether it has the effect of improving endothelial function and lowering blood pressure in Ang II-induced hypertensive mice remains unclear.

METHODS

In this study, hypertension was induced by continuous infusion of Ang II with a subcutaneous osmotic pumps and ghrelin (30 μg/kg/day) was intraperitoneal injection for 4 weeks. Acetylcholine-induced endothelium-dependent relaxation in aortae was measured on wire myograph and superoxide production in mouse aortae was assessed by fluorescence imaging.

RESULTS

We found that ghrelin had protective effects on Ang II-induced hypertension by inhibiting oxidative stress, increasing NO production, improving endothelial function, and lowering blood pressure. Furthermore, ghrelin activated AMPK signaling in Ang II-induced hypertension, leading to inhibition of oxidative stress. Compound C, a specific inhibitor of AMPK, reversed the protective effects of ghrelin on the reduction of oxidative stress, the improvement of endothelial function and the reduction of blood pressure.

CONCLUSIONS

our findings indicated that ghrelin protected against Ang II-induced hypertension by improving endothelial function and lowering blood pressure partly through activating AMPK signaling. Thus, ghrelin may be a valuable therapeutic strategy for hypertension.

High salt-induced morphological and glycocalyx remodeling of human vascular smooth muscle cells is reversible but induces a high sodium salt-like sensitive memory

Our recent work showed that short-term treatment (1-2 days) with high sodium salt had no effect on the morphology of human vascular smooth muscle cells (hVSMCs). However, chronic (long-term treatment, 6-16 days) high sodium salt (CHSS) induced hypertrophy and decreased the relative density of the glycocalyx in hVSMCs. Whether this CHSS effect is reversible at both the morphological and the intracellular calcium and sodium levels is unknown. In the present study, we tested the hypothesis that the effect of CHSS on the morphological and functional levels of hVSMCs is reversible. However, it induced an irreversible increase in the sensitivity of the cells following short-term treatment with high extracellular Na+. We tested the effects of the removal of CHSS treatment on the morphology and intracellular sodium and calcium of hVSMCs. Our results showed that restoring average sodium concentration (145 mM) modeled back the relative density of the glycocalyx, the intracellular resting calcium and sodium levels, and the whole cell and nuclear volumes of hVSMCs. In addition, it induced a permanent remodeling of hVSMCs' response to a short-term increase in the extracellular level of sodium salt by developing spontaneous cytosolic and nuclear calcium waves. Our results showed that CHSS is reversible at both the morphological and basal intracellular ionic levels. However, it maintained a high sensitivity to short-term elevation of extracellular sodium. These results suggest that even if chronic high salt is corrected, it induces a high sodium salt-like sensitive memory.

Dietary factors and hypertension risk in West Africa: a systematic review and meta-analysis of observational studies

BACKGROUND

Contrary to North America and Europe, the prevalence of hypertension is rising in West Africa. Although diet is implicated as a contributor to this trend, nutritional guidelines in West Africa are not tailored to address this concern. This study aimed to address this limitation by investigating dietary factors common to West Africa and evaluating their association with hypertension.

METHODS

PubMed, Scopus, Web of Science, and Medline were searched to identify studies that investigated diet and hypertension in West African adults. All meta-analyses used a generic inverse-variance random effects model, with subgroup analyses by age, BMI, and study location, and were performed in R.

RESULTS

Three thousand, two hundred ninety-eight studies were identified, of which 31 ( n  = 48 809 participants) satisfied inclusion criteria - all cross-sectional. Meta-analyses of the association between dietary factors and hypertension included dietary fat [odds ratio (OR) = 1.76; 95% confidence interval (95% CI) 1.44-2.14; P  < 0.0001], red meat (OR = 1.51; 95% CI: 1.04-2.18; P  = 0.03), junk-food (OR = 1.41; 95% CI: 1.19-1.67; P  < 0.0001), dietary salt (OR = 1.25; 95% CI: 1.12-1.40; P  < 0.0001), alcohol (OR = 1.17; 95% CI: 1.03-1.32; P  = 0.013), and 'fruits and vegetables' (OR = 0.80; 95% CI: 0.24-1.17; P  < 0.0001). Subgroup analyses suggested that 'fruit and vegetable' consumption is less protective in the elderly.

CONCLUSION

High consumption of dietary salt, red meat, dietary fat, junk food, and alcohol are associated with increased odds of hypertension, whereas high fruit and vegetable appear protective. This region-specific evidence will support the development of nutritional assessment tools for clinicians, patients, and researchers aiming to reduce hypertension in West Africa.

A high-salt diet promotes hypertrophic scarring through TRPC3-mediated mitochondrial Ca2+ homeostasis dysfunction

Diet High in salt content have been associated with cardiovascular disease and chronic inflammation. We recently demonstrated that transient receptor potential canonical 3 (TRPC3) channels regulate myofibroblast transdifferentiation in hypertrophic scars. Here, we examined how high salt activation of TRPC3 participates in hypertrophic scarring during wound healing. In vitro, we confirmed that high salt increased the TRPC3 protein expression and the marker of myofibroblast alpha smooth muscle actin (α-SMA) in wild-type mice (WT) primary cultured dermal fibroblasts but not Trpc3-/- mice. Activation of TRPC3 by high salt elevated cytosolic Ca2+ influx and mitochondrial Ca2+ uptake in dermal fibroblasts in a TRPC3-dependent manner. High salt activation of TRPC3 enhanced mitochondrial respiratory dysfunction and excessive ROS production by inhibiting pyruvate dehydrogenase action, that activated ROS-triggered Ca2+ influx and the Rho kinase/MLC pathway in WT mice but not Trpc3-/- mice. In vivo, a persistent high-salt diet promoted myofibroblast transdifferentiation and collagen deposition in a TRPC3-dependent manner. Therefore, this study demonstrates that high salt enhances myofibroblast transdifferentiation and promotes hypertrophic scar formation through enhanced mitochondrial Ca2+ homeostasis, which activates the ROS-mediated pMLC/pMYPT1 pathway. TRPC3 deficiency antagonizes high salt diet-induced hypertrophic scarring. TRPC3 may be a novel target for hypertrophic scarring during wound healing.

Hypertensive heart disease: risk factors, complications and mechanisms

Hypertensive heart disease constitutes functional and structural dysfunction and pathogenesis occurring primarily in the left ventricle, the left atrium and the coronary arteries due to chronic uncontrolled hypertension. Hypertensive heart disease is underreported and the mechanisms underlying its correlates and complications are not well elaborated. In this review, we summarize the current understanding of hypertensive heart disease, we discuss in detail the mechanisms associated with development and complications of hypertensive heart disease especially left ventricular hypertrophy, atrial fibrillation, heart failure and coronary artery disease. We also briefly highlight the role of dietary salt, immunity and genetic predisposition in hypertensive heart disease pathogenesis.

Endothelial Damage Arising From High Salt Hypertension Is Elucidated by Vascular Bed Systematic Profiling

BACKGROUND

Considerable evidence links dietary salt intake with the development of hypertension, left ventricular hypertrophy, and increased risk of stroke and coronary heart disease. Despite extensive epidemiological and basic science interrogation of the relationship between high salt (HS) intake and blood pressure, it remains unclear how HS impacts endothelial cell (EC) and vascular structure in vivo. This study aims to elucidate HS-induced vascular pathology using a differential systemic decellularization in vivo approach.

METHODS

We performed systematic molecular characterization of the endothelial glycocalyx and EC proteomes in mice with HS (8%) diet-induced hypertension versus healthy control animals. Isolation of eGC and EC compartments was achieved using differential systemic decellularization in vivo methodology. Altered protein expression in hypertensive compared to normal mice was characterized by liquid chromatography tandem mass spectrometry. Proteomic results were validated using functional assays, microscopic imaging, and histopathologic evaluation.

RESULTS

Proteomic analysis revealed a significant downregulation of eGC and associated proteins in HS diet-induced hypertensive mice (among 1696 proteins identified in this group, 723 were markedly decreased in abundance, while only 168 were increased in abundance. Bioinformatic analysis indicated substantial derangement of the eGC layer, which was subsequently confirmed by fluorescent and electron microscopy assessment of vessel damage ex vivo. In the EC fraction, HS-induced hypertension significantly altered protein mediators of contractility, metabolism, mechanotransduction, renal function, and the coagulation cascade. In particular, we observed dysregulation of integrin subunits α2, α2b, and α5, which was associated with arterial wall inflammation and substantial infiltration of CD68+ monocyte-macrophages. Consequently, HS-induced hypertensive mice also displayed reduced vascular integrity of multiple organs including lungs, kidneys, and heart.

CONCLUSIONS

These findings provide novel molecular insight into HS-induced structural changes in eGC and EC composition that may increase cardiovascular risk and potentially guide the development of new diagnostics and therapeutic interventions.

Salt Consumption and Blood Pressure in Rural Hypertensive Participants: A Community Filed Trial

Purpose. Hypertension is a major cause of morbidity and mortality in the world. This study aimed to evaluate an intervention based on the Health Belief Model regarding the whole family’s salt consumption and blood pressure among hypertensive patients in rural areas in Iran. Methods. This clinical multicenter trial (clinical and community) with a control and an intervention group was conducted on the residents of 14 villages covered by 14 health houses. Totally, 200 hypertensive patients (n = 100 in each group) were selected via multistage random sampling. The intervention included a two-day workshop on blood pressure and reducing salt consumption based on HBM structures for health personnel and an eight-session workshop on how to reduce salt intake and blood pressure for mothers who were responsible for the families’ diets. Participants completed the questionnaires before and immediately after the intervention. Results. Compared to the control group, in the intervention group, a significant reduction was observed in salt consumption by the families (urine sodium and creatinine reduced by 35 mEq/l and 7.5 mg/dL, respectively). The results also revealed a significant decrease in blood pressure in the intervention group. Conclusion. The results showed that the mothers’ model-based education could effectively improve the diet of the whole family members and, as a result, reduce the associated diseases. The main advantage of this study was the involvement of the rural health personnel, which helped run longer and larger-scale health-promotion programs in the communities.

Self-Care by Muslim Women during Ramadan Fasting to Protect Nutritional and Cardiovascular Health

The practice of Ramadan involves a series of changes in lifestyle, mainly in eating habits. The research aim of this study is to determine the prevalence of overweight-obesity, the degree of compliance with dietary recommendations and the effects of religious fasting on cardiovascular health among a population of Muslim women living in Melilla, a Spanish city in North Africa. A follow-up cohort study was conducted on 62 healthy adult women (33.6 ± 12.7 years). Anthropometric and body composition parameters were obtained using bioimpedance and dietary records. All of the participants were overweight or obese, especially due to the non-compliance with dietary recommendations; however, more than 60% considered their weight was appropriate or even low. By the end of Ramadan, the women's body mass index and fat component values had fallen significantly (p < 0.001), but this loss was later recovered. Dietary records revealed an excessive consumption of lipids and sodium, and the presence of a high waist-to-hip ratio. All of these factors are related to cardiovascular risk. In conclusion, promoting nutritional health and encouraging year-round self-care among adult Muslim women is necessary in order to ensure healthy fasting during Ramadan.

Therapeutic targeting of inflammation in hypertension: from novel mechanisms to translational perspective

Both animal models and human observational and genetic studies have shown that immune and inflammatory mechanisms play a key role in hypertension and its complications. We review the effects of immunomodulatory interventions on blood pressure, target organ damage, and cardiovascular risk in humans. In experimental and small clinical studies, both non-specific immunomodulatory approaches, such as mycophenolate mofetil and methotrexate, and medications targeting T and B lymphocytes, such as tacrolimus, cyclosporine, everolimus, and rituximab, lower blood pressure and reduce organ damage. Mechanistically targeted immune interventions include isolevuglandin scavengers to prevent neo-antigen formation, co-stimulation blockade (abatacept, belatacept), and anti-cytokine therapies (e.g. secukinumab, tocilizumab, canakinumab, TNF-α inhibitors). In many studies, trial designs have been complicated by a lack of blood pressure-related endpoints, inclusion of largely normotensive study populations, polypharmacy, and established comorbidities. Among a wide range of interventions reviewed, TNF-α inhibitors have provided the most robust evidence of blood pressure lowering. Treatment of periodontitis also appears to deliver non-pharmacological anti-hypertensive effects. Evidence of immunomodulatory drugs influencing hypertension-mediated organ damage are also discussed. The reviewed animal models, observational studies, and trial data in humans, support the therapeutic potential of immune-targeted therapies in blood pressure lowering and in hypertension-mediated organ damage. Targeted studies are now needed to address their effects on blood pressure in hypertensive individuals.

High Na+ Salt Diet and Remodeling of Vascular Smooth Muscle and Endothelial Cells

Our knowledge on essential hypertension is vast, and its treatment is well known. Not all hypertensives are salt-sensitive. The available evidence suggests that even normotensive individuals are at high cardiovascular risk and lower survival rate, as blood pressure eventually rises later in life with a high salt diet. In addition, little is known about high sodium (Na⁺) salt diet-sensitive hypertension. There is no doubt that direct and indirect Na⁺ transporters, such as the Na/Ca exchanger and the Na/H exchanger, and the Na/K pump could be implicated in the development of high salt-induced hypertension in humans. These mechanisms could be involved following the destruction of the cell membrane glycocalyx and changes in vascular endothelial and smooth muscle cells membranes’ permeability and osmolarity. Thus, it is vital to determine the membrane and intracellular mechanisms implicated in this type of hypertension and its treatment.

Potential mechanisms of Guizhi decoction against hypertension based on network pharmacology and Dahl salt-sensitive rat model

Background

Guizhi decoction (GZD), a classical Chinese herbal formula, has been widely used to treat hypertension, but its underlying mechanisms remain elusive. The present study aimed to explore the potential mechanisms and therapeutic effects of GZD on hypertension by integrating network pharmacology and experimental validation.

Methods

The active ingredients and corresponding targets were collected from the Traditional Chinese Medicine Systems Pharmacology database and Analysis Platform (TCMSP). The targets related to hypertension were identified from the CTD, GeneCards, OMIM and Drugbank databases. Multiple networks were constructed to identify the key compounds, hub targets, and main biological processes and pathways of GZD against hypertension. The Surflex-Dock software was used to validate the binding affinity between key targets and their corresponding active compounds. The Dahl salt-sensitive rat model was used to evaluate the therapeutic effects of GZD against hypertension.

Results

A total of 112 active ingredients, 222 targets of GZD and 341 hypertension-related targets were obtained. Furthermore, 56 overlapping targets were identified, five of which were determined as the hub targets for experimental verification, including interleukin 6 (IL-6), C–C motif chemokine 2 (CCL2), IL-1β, matrix metalloproteinase 2 (MMP-2), and MMP-9. Pathway enrichment analysis results indicated that 56 overlapping targets were mainly enriched in several inflammation pathways such as the tumor necrosis factor (TNF) signaling pathway, Toll-like receptor (TLR) signaling pathway and nuclear factor kappa-B (NF-κB) signaling pathway. Molecular docking confirmed that most active compounds of GZD could bind tightly to the key targets. Experimental studies revealed that the administration of GZD improved blood pressure, reduced the area of cardiac fibrosis, and inhibited the expression of IL-6, CCL2, IL-1β, MMP-2 and MMP-9 in rats.

Conclusion

The potential mechanisms and therapeutic effects of GZD on hypertension may be attributed to the regulation of cardiac inflammation and fibrosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13020-021-00446-x.

Salt and Sugar: Two Enemies of Healthy Blood Pressure in Children

The prevalence of essential arterial hypertension in children and adolescents has grown considerably in the last few decades, making this disease a major clinical problem in the pediatric age. The pathogenesis of arterial hypertension is multifactorial, with one of the components being represented by incorrect eating habits. In particular, excessive salt and sugar intake can contribute to the onset of hypertension in children, particularly in subjects with excess weight. Babies have an innate predisposition for sweet taste, while that for salty taste manifests after a few weeks. The recent modification of dietary styles and the current very wide availability of salt and sugar has led to an exponential increase in the consumption of these two nutrients. The dietary intake of salt and sugar in children is in fact much higher than that recommended by health agencies. The purpose of this review is to explore the mechanisms via which an excessive dietary intake of salt and sugar can contribute to the onset of arterial hypertension in children and to show the most important clinical studies that demonstrate the association between these two nutrients and arterial hypertension in pediatric age. Correct eating habits are essential for the prevention and nondrug treatment of essential hypertension in children and adolescents.

Hypertension-mediated organ damage regression associates with blood pressure variability improvement three years after successful treatment initiation in essential hypertension

Blood pressure variability (BPV) has been associated with the development, progression, and severity of cardiovascular (CV) organ damage and an increased risk of CV morbidity and mortality. We aimed to explore any association between short‐term BPV reduction and hypertension‐mediated organ damage (HMOD) regression in hypertensive patients 3‐year post‐treatment initiation regarding BP control. 24‐h ambulatory blood pressure monitoring (24 h ABPM) was performed at baseline in 180 newly diagnosed and never‐treated hypertensive patients. We measured 24 h average systolic (24 h SBP) and diastolic BP (24 h DBP) as well as 24 h systolic (sBPV) and diastolic BPV (dBPV). Patients were initially evaluated and 3 years later regarding arterial stiffness (PWV), left ventricular hypertrophy (LVMI), carotid intima‐media thickness (cIMT), 24 h microalbumin levels (MAU), and coronary flow reserve (CFR). Successful BP treatment was defined as 24 h SBP/DBP < 130/80 mm Hg based on 2nd ABPM and subsequently, patients were characterized as controlled (n = 119, age = 53 ± 11 years) or non‐controlled (n = 61, age = 47 ± 11 years) regarding their BP levels. In the whole population and the controlled group, 24 h SBP/DBP, sBPV/dBPV, LVMI, and IMT were decreased. Additionally, LVMI improvement was related with both sBPV (p < .001) and dBPV reduction (r = .18, p = .02 and r = .20, p = .03, respectively). In non‐controlled hypertensives, PWV was increased. In multiple linear regression analysis, sBPV and dBPV reduction predicted LVMI improvement in total population and controlled group independently of initial office SBP, mean BP, and 24 h‐SBP levels. In middle‐aged hypertensive patients, a 3‐year antihypertensive treatment within normal BP limits, confirmed by 24‐h ABPM, leads to CV risk reduction associated with sBPV and dBPV improvement.

Traditional Chinese medicine protects against hypertensive kidney injury in Dahl salt-sensitive rats by targeting transforming growth factor-β signaling pathway

This study investigated the therapeutic efficacy of Bu-Shen-Jiang-Ya decoction (BSJYD) on hypertensive renal damage to determine whether it regulates the expression of transforming growth factor-β (TGF-β)/SMADs signaling pathways, thereby relieving renal fibrosis in Dahl salt-sensitive (SS) rats. Dahl SS rats on a high-sodium diet were prospectively treated with BSJYD (n = 12) or valsartan (n = 12) for 8 weeks. The blood pressure (BP) of these rats was measured and their kidneys were subjected to biochemical analysis, including serum creatinine (Scr) and blood urea nitrogen (BUN); hematoxylin and eosin staining; Masson trichrome staining; real-time polymerase chain reaction; and western blot analysis. The primary outcome was that BSJYD significantly reduced BP, debased BUN, and Scr and ameliorated renal pathological changes. As underlying therapeutic mechanisms, BSJYD reduces TGFβ1 and Smad2/3 expression and suppresses renal fibrosis, as suggested by the decreased expression of connective tissue growth factor(CTGF). These data suggest that BSJYD acts as an optimal therapeutic agent for hypertensive renal damage by inhibiting the TGF-β/SMADs signaling pathway.

Vascular smooth muscle remodeling in health and disease

In blood vessels, vascular smooth muscle cells (VSMCs) generally exist in two major phenotypes: contractile and non-contractile (synthetic). The contractile phenotype is predominant and includes quiescent or differentiated VSMCs, which function as the regulators of blood vessel diameter and blood flow. According to some literature in the field, contractile VSMCs do not switch to the non-contractile phenotype due to the activation of specific transcription factors that are considered as guardians of the contractile phenotype. However, a vast amount of the literature uses the terms remodeling and phenotype switching of contractile VSMCs interchangeably based mainly on studies dealing with atherosclerosis. The use of the terms remodeling and switching to describe changes in phenotype based on morphological criteria can be confusing. The term remodeling was first used to describe morphological changes in the heart and was soon used to describe phenotype changes of contractile VSMCs based on morphological criteria. The latter were introduced in early studies, and new molecular criteria were later added, including changes in gene expression, which could be irreversible. In this review, we will discuss the different views concerning remodeling and possible switching of contractile VSMCs to a non-contractile phenotype. We conclude that only remodeling of contractile VSMCs may take place upon vascular injury and disease.

[Effects of lifestyle interventions for arterial hypertension in primary care: A systematic review]

BACKGROUND

The proportion of adults suffering from hypertension worldwide was estimated at 31.1 % in 2010. The aim of this study was to evaluate the effects of lifestyle changes in patients with arterial hypertension (AH) in primary care.

MATERIAL AND METHODS

Systematic literature search in the online databases PubMed, Embase, Cochrane and Opengrey. Only randomized controlled trials of the years 2005 to 2017 in German or English were considered.

RESULTS

11 studies out of 458 identified references were evaluated. The patient groups investigated were very heterogeneous and underwent different types of intervention. Educating patients about the clinical picture, regular self-measurements of blood pressure, or patient memories of maintaining a healthy lifestyle have been used most frequently.

CONCLUSION

There is a need for further studies focusing on primary care. However, many lifestyle interventions seem to show very good effects in patients with pre-existing AH (secondary prophylaxis), so these measures should form the basis of antihypertensive therapy in all patients with AH. In addition, it is important to maintain advice on a healthy lifestyle during drug therapy.

Sodium-hydrogen exchanger regulatory factor-1 (NHERF1) confers salt sensitivity in both male and female models of hypertension in aging

Hypertension is a risk factor for premature death and roughly 50% of hypertensive patients are salt-sensitive. The incidence of salt-sensitive hypertension increases with age. However, the mechanisms of salt-sensitive hypertension are not well understood. We had demonstrated decreased renal sodium‑hydrogen exchanger regulatory factor 1 (NHERF1) expression in old salt-resistant F344 rats. Based on those studies we hypothesized that NHERF1 expression is required for the development of some forms of salt-sensitive hypertension. To address this hypothesis, we measured blood pressure in NHERF1 expressing salt-sensitive 4-mo and 24-mo-old male and female Fischer Brown Norway (FBN) rats male and female 18-mo-old NHERF1 knock-out (NHERF1-/-) mice and wild-type (WT) littermates on C57BL/6J background after feeding high salt (8% NaCl) diet for 7 days. Our data demonstrate that 8% salt diet increased blood pressure in both male and female 24-mo-old FBN rats but not in 4-mo-old FBN rats and in 18-mo-old male and female WT mice but not in NHERF1-/- mice. Renal dopamine 1 receptor (D1R) expression was decreased in 24-mo-old rats, compared with 4-mo-old FBN rats. However, sodium chloride cotransporter (NCC) expression increased in 24-mo-old FBN rats. In FBN rats, age had no effect on NaK ATPase α1 and NKCC2 expression. By contrast, high salt diet increased the renal expressions of NKCC2, and NCC in 24-mo-old FBN rats. High salt diet also increased NKCC2 and NCC expression in WT mice but not NHERF1-/- mice. Our data suggest that renal NHERF1 expression confers salt sensitivity with aging, associated with increased expression of sodium transporters.

High-salt intake increases TRPC3 expression and enhances TRPC3-mediated calcium influx and systolic blood pressure in hypertensive patients

Enhanced transient receptor potential canonical subtype 3 (TRPC3) expression and TRPC3-mediated calcium influx in monocytes from hypertensive rats and patients are associated with increased blood pressure. Daily salt intake is closely related to hypertension, but the relationship between TRPC3 expression and salt intake has not yet been evaluated in hypertensive patients. Using reverse transcription-polymerase chain reaction, we studied the expression of TRPC3 and TRPC3-related store-operated calcium entry (SOCE) in peripheral blood mononuclear cells (PBMCs) from hypertensive and normotensive control subjects. Measurement of SOCE was performed using the fluorescent dye Fura-2 AM. Participants were divided into a low-salt group (<9 g) and a high-salt group (≥9 g) based on 24-h urinary sodium excretion. Increased TRPC3 mRNA expression levels and SOCE were observed in THP-1 cells after high-NaCl treatment. However, administration of the TRPC3-specific inhibitor Pyr3 significantly decreased the effect. Furthermore, the TRPC3 mRNA expression levels in PBMCs from high-salt intake patients with essential hypertension were significantly higher than those in low-salt intake patients compared with those in normotensive control subjects. We also observed significantly increased TRPC3-mediated SOCE in PBMCs from hypertensive subjects (but not from normotensive control subjects), with calcium concentration correlating with salt intake. More importantly, TRPC3 mRNA levels showed a significant correlation with salt intake and systolic blood pressure in patients with essential hypertension. This study demonstrated, for the first time, that increased TRPC3 mRNA levels are associated with elevated salt intake and systolic blood pressure in hypertensive patients.

Sodium Intake and Hypertension

The close relationship between hypertension and dietary sodium intake is widely recognized and supported by several studies. A reduction in dietary sodium not only decreases the blood pressure and the incidence of hypertension, but is also associated with a reduction in morbidity and mortality from cardiovascular diseases. Prolonged modest reduction in salt intake induces a relevant fall in blood pressure in both hypertensive and normotensive individuals, irrespective of sex and ethnic group, with larger falls in systolic blood pressure for larger reductions in dietary salt. The high sodium intake and the increase in blood pressure levels are related to water retention, increase in systemic peripheral resistance, alterations in the endothelial function, changes in the structure and function of large elastic arteries, modification in sympathetic activity, and in the autonomic neuronal modulation of the cardiovascular system. In this review, we have focused on the effects of sodium intake on vascular hemodynamics and their implication in the pathogenesis of hypertension.