Diabetes, hypertension, and cardiovascular disease: clinical insights and vascular mechanisms

Hypertension and type 2 diabetes are common comorbidities. Hypertension is twice as frequent in patients with diabetes compared with those who do not have diabetes. Moreover, patients with hypertension often exhibit insulin resistance and are at greater risk of diabetes developing than are normotensive individuals. The major cause of morbidity and mortality in diabetes is cardiovascular disease, which is exacerbated by hypertension. Accordingly, diabetes and hypertension are closely interlinked because of similar risk factors, such as endothelial dysfunction, vascular inflammation, arterial remodelling, atherosclerosis, dyslipidemia, and obesity. There is also substantial overlap in the cardiovascular complications of diabetes and hypertension related primarily to microvascular and macrovascular disease. Common mechanisms, such as upregulation of the renin-angiotensin-aldosterone system, oxidative stress, inflammation, and activation of the immune system likely contribute to the close relationship between diabetes and hypertension. In this article we discuss diabetes and hypertension as comorbidities and discuss the pathophysiological features of vascular complications associated with these conditions. We also highlight some vascular mechanisms that predispose to both conditions, focusing on advanced glycation end products, oxidative stress, inflammation, the immune system, and microRNAs. Finally, we provide some insights into current therapies targeting diabetes and cardiovascular complications and introduce some new agents that may have vasoprotective therapeutic potential in diabetes

Serotonin signaling through the 5-HT1B receptor and NADPH oxidase 1 in pulmonary arterial hypertension

Objective: Serotonin can induce human pulmonary artery smooth muscle cell (hPASMC) proliferation through reactive oxygen species (ROS), influencing the development of pulmonary arterial hypertension (PAH). We hypothesise that in PASMCs, serotonin induces oxidative stress through NADPH-oxidase-derived ROS generation and reduced Nrf-2 anti-oxidant systems, promoting vascular injury. Approach and Results: HPASMCs from controls and PAH patients, and PASMCs from Nox1-/- mice, were stimulated with serotonin in the absence/presence of inhibitors of Src kinase, the 5-HT1B receptor and NADPH oxidase 1 (Nox1). Markers of fibrosis were also determined. The pathophysiological significance of our findings was examined in vivo in serotonin transporter overexpressing (SERT+) female mice, a model of pulmonary hypertension (PH). We confirmed serotonin increased superoxide and H2O2 production in these cells. For the first time, we show that serotonin increased oxidized protein tyrosine phosphatases and peroxiredoxin-SO3H and decreased Nrf-2 and catalase activity in hPASMCs. ROS generation was exaggerated, and dependent on c-Src, 5-HT1B receptor and the serotonin transporter in PAH-hPASMCs. Proliferation and extracellular matrix remodeling were exaggerated in PAH-hPASMCs and dependent on 5-HT1B receptor signaling and Nox1, confirmed in PASMCs from Nox1-/- mice. In SERT+ mice, SB216641, a 5-HT1B receptor antagonist, prevented development of PH in a ROS-dependent manner. Conclusions: Serotonin can induce c-Src-regulated Nox1-induced ROS and Nrf-2 dysregulation, contributing to increased post-translational oxidative modification of proteins, activation of redox-sensitive signaling pathways in hPASMCs; associated with mitogenic responses. 5-HT1B receptors contribute to experimental PH by inducing lung ROS production. Our results suggest 5-HT1B receptor-dependent c-Src-Nox1-pathways contribute to vascular remodeling in PAH

Anti‐atherosclerotic effect of the angiotensin 1–7 mimetic AVE0991 is mediated by inhibition of perivascular and plaque inflammation in early atherosclerosis

Background and Purpose: Inflammation plays a key role in atherosclerosis. A protective role of angiotensin-(1-7) in vascular pathologies opened a possibility for therapeutic use of small molecule non-peptide Ang-(1-7) mimetics, such as AVE0991. The mechanisms of these vaso-protective effects of a Mas receptor agonist, AVE0991, remain unclear. Experimental approach: We investigated the effects of AVE0991 on the spontaneous atherosclerosis in ApoE-/- mice, in the context of vascular inflammation and plaque stability. Key Results: AVE0991 has significant anti-atherosclerotic properties in ApoE-/- mice and increases plaque stability, by reducing plaque macrophage content, without effects on collagen. Using descending aorta of chow fed ApoE-/- mice, before significant atherosclerotic plaque develops, we gained insight to early events in atherosclerosis. Interestingly, perivascular adipose tissue (pVAT) and adventitial infiltration with macrophages and T cells precedes atherosclerotic plaque or the impairment of endothelium-dependent NO bioavailability as a measure of endothelial function. AVE0991 inhibited perivascular inflammation, through the reduction of chemokine expression in pVAT, as well as through direct actions on monocytes/macrophages inhibiting their activation, characterized by IL-1β, TNF-α, MCP-1 and CXCL10 and differentiation to M1 phenotype. Pre-treatment with AVE0991 inhibited migration of THP-1 monocytes towards supernatants of activated adipocytes (SW872). Mas receptors were expressed in pVAT and in THP-1 cells in vitro and anti-inflammatory effects of AVE0991 were partially Mas dependent. Conclusions & implications: Selective Mas receptor agonist AVE0991 possesses anti-atherosclerotic and anti-inflammatory properties, affecting monocyte/macrophage differentiation and recruitment to perivascular space at early stages of atherosclerosis in ApoE-/- mice

The serotonin transporter promotes a pathological estrogen metabolic pathway in pulmonary hypertension via cytochrome P450 1B1 pulmonary circulation

Pulmonary arterial hypertension (PAH) is a devastating vasculopathy that predominates in women and has been associated with dysregulated estrogen and serotonin signaling. Overexpression of the serotonin transporter (SERT+) in mice results in an estrogen-dependent development of pulmonary hypertension (PH). Estrogen metabolism by cytochrome P450 1B1 (CYP1B1) contributes to the pathogenesis of PAH, and serotonin can increase CYP1B1 expression in human pulmonary arterial smooth muscle cells (hPASMCs). We hypothesized that an increase in intracellular serotonin via increased SERT expression may dysregulate estrogen metabolism via CYP1B1 to facilitate PAH. Consistent with this hypothesis, we found elevated lung CYP1B1 protein expression in female SERT+ mice accompanied by PH, which was attenuated by the CYP1B1 inhibitor 2,3',4,5'-tetramethoxystilbene (TMS). Lungs from female SERT+ mice demonstrated an increase in oxidative stress that was marked by the expression of 8-hydroxyguanosine; however, this was unaffected by CYP1B1 inhibition. SERT expression was increased in monocrotaline-induced PH in female rats; however, TMS did not reverse PH in monocrotaline-treated rats but prolonged survival. Stimulation of hPASMCs with the CYP1B1 metabolite 16α-hydroxyestrone increased cellular proliferation, which was attenuated by an inhibitor (MPP) of estrogen receptor alpha (ERα) and a specific ERα antibody. Thus, increased intracellular serotonin caused by increased SERT expression may contribute to PAH pathobiology by dysregulation of estrogen metabolic pathways via increased CYP1B1 activity. This promotes PASMC proliferation by the formation of pathogenic metabolites of estrogen that mediate their effects via ERα. Our studies indicate that targeting this pathway in PAH may provide a promising antiproliferative therapeutic strategy

Is it time to reappraise blood pressure thresholds and targets? Statement from the international society of hypertension - a global perspective

No abstract available

Associations between parents' body weight/shape comments and disordered eating amongst adolescents over time : a longitudinal study

Parents are key influencers of adolescents’ attitudes on weight, shape, and eating, and make more positive than negative comments, with negative comments most impactful. This study examined prospective unique associations of parental positive and negative comments in a community sample of adolescents with paediatric psychosocial quality of life (PED-QoL), Eating Disorder Weight/Shape Cognitions (EDEQ-WS), BMI percentile, and Psychological Distress (K10) scales. Data were from 2056 adolescents from the EveryBODY study cohort. Multiple regressions were conducted for the impacts of parental positive and negative comments on four dependent variables at one year after controlling for their stage of adolescence (early, middle, late). Multiple imputation and bootstrapping were used for handling missing data and violations of normality. Results indicated that positive maternal comments on eating were associated with increased EDCs and better quality of life at one year. Paternal positive weight shape comments were associated with a decrease in psychological distress, but positive eating comments saw a decrease in quality of life. Findings highlight the nuances of parental comments and how these are perceived and interpreted, and could alert health care workers and family practitioners who have weight, shape, and eating conversations to be aware of the potential influence of their communication

An exploration of how adolescents experience and reason their parents' comments on their weight, shape, and eating

Introduction: Disordered eating among adolescents is of increasing concern given associated physical and mental health sequelae. Cognitions underlying disordered eating are formed in childhood and adolescence. Parents are a significant presence during this period, so it is critical to understand how they influence their adolescent's eating cognitions and behaviors. Methods: Qualitative analysis using interpretative phenomenological analysis (IPA) methodology was employed to consider the lived experiences of 10 Australian adolescents (14-19 years), 60% female, as they engaged with their parents in a range of weight, shape, and eating communications. Results: Our inductive IPA revealed three key themes representing adolescents' experiences and meaning-making: Parents as Influencers-adolescents acknowledged parents are influencers (objects) within a wider context of community and cultural norms (symbols) and can be protective for peer influence on body image ideals; Expression and Perception-the "what" (weight-talk as an object) and the "how" (objects as independent influences) of gendered parental communication related to health and fitness ideals and illustrated diverse interpretations of both verbal and non-verbal expression; and Fertile Soil and Maturity-the adolescent's characteristics and context influence perceptions of communication, a fear of deviating from norms, and an overarching focus on being "healthy" yet not always knowing what that was. Perception of bidirectional communication also offered valuable insights into potential dangers through family loyalty and in-group permissions. Conclusions: Findings highlight implications for the nuanced influence of parental communication and illustrate the pivotal role of parents within the bioecosystem of adolescent development

Novel therapeutic approaches targeting the renin angiotensin system and associated peptides in hypertension and heart failure

Despite the success of renin-angiotensin system (RAS) blockade by angiotensin-converting enzyme (ACE) inhibitors and angiotensin II type 1 receptor (AT1R) blockers, current therapies for hypertension and related cardiovascular diseases are still inadequate. Identification of additional components of the RAS and associated vasoactive pathways, as well as new structural and functional insights into established targets, have led to novel therapeutic approaches with the potential to provide improved cardiovascular protection and better blood pressure control and/or reduced adverse side effects. The simultaneous modulation of several neurohumoral mediators in key interconnected blood pressure–regulating pathways has been an attractive approach to improve treatment efficacy, and several novel approaches involve combination therapy or dual-acting agents. In addition, increased understanding of the complexity of the RAS has led to novel approaches aimed at upregulating the ACE2/angiotensin-(1-7)/Mas axis to counter-regulate the harmful effects of the ACE/angiotensin II/angiotensin III/AT1R axis. These advances have opened new avenues for the development of novel drugs targeting the RAS to better treat hypertension and heart failure. Here we focus on new therapies in preclinical and early clinical stages of development, including novel small molecule inhibitors and receptor agonists/antagonists, less conventional strategies such as gene therapy to suppress angiotensinogen at the RNA level, recombinant ACE2 protein, and novel bispecific designer peptides

Exploring associations between positive and negative valanced parental comments about adolescents' bodies and eating and eating problems : a community study

Background: Adolescence is a time of rapid emotional and physical development when foundational self-concepts (including beliefs about one’s weight and shape) are established. Parents are key influencers of adolescent beliefs and behaviours. This study aimed to investigate associations between perceived positive and negative parental comments on weight/shape and eating, with sons’ and daughters’ psychological distress and eating disorder cognitions (EDCs). Methods: A representative mixed-sex sample of 2204 Australian adolescents (12–19 years) from the EveryBODY Study completed an online survey exploring eating behaviours, psychological wellbeing and experiences of parental comments regarding weight, shape and eating behaviours. Results: Correlation analyses revealed that adolescents’ reports of perceived positive parental comments on shape/ weight were significantly associated with lower psychological distress and EDCs only for daughters. All perceived negative parental comments on shape/weight or eating were associated with greater psychological distress and EDCs for both sons and daughters. In the final model of the regression analysis, only perceived parental negative shape/weight and maternal negative eating comments, adolescent stage and biological sex were significantly associated with EDCs. When known contributors such as BMI percentile and psychological distress were included in the regression model, adolescent stage and perceived negative paternal comments were no longer significantly associated with EDCs. Conclusions: Overall, results show perceived negative comments were associated with poorer adolescent mental health, both their specific EDCs and general distress. Findings highlight the importance of raising awareness of potential negative impacts within family systems of comments around weight/shape and eating in these key formative years

Progressive hypertension and severe left ventricular outflow tract obstruction

No abstract available