Insulin receptor signalling in PDGFRß-expressing cells influences systemic metabolism and negatively impacts lipid storage.

Pericytes are vascular mural cells that support the microvasculature; their dysfunction contributes to diabetic retinopathy and has been linked to obesity in humans. To explore the role of pericyte insulin signalling on systemic metabolism we utilised male mice from our previously described PIR-/- (PIRKO) mouse line which has insulin receptor (Insr) knockout in PDGFRß-expressing cells. These animals exhibit systemic insulin resistance from as early as 8-weeks of age, despite no change in body weight or activity level, and show altered body composition and hepatosteatosis. When challenged with high fat diet, PIR-/- remain insulin resistant but are protected from weight gain with reduced adipose tissue expansion across all depots and altered adipose morphology. Exhibiting parallels with the metabolically-obese-normal-weight (MONW) human phenotype, the PIR-/- line underlines the importance of pericyte biology in the development of both diabetes and obesity and establishes the angiopoietin (Ang)/Tie signalling pathway as a focus for future research.

Small molecule modulation of insulin receptor-insulin like growth factor-1 receptor heterodimers in human endothelial cells.

OBJECTIVES: The insulin receptor (IR) and insulin like growth factor-1 receptor (IGF-1R) are heterodimers consisting of two extracellular α-subunits and two transmembrane ß -subunits. Insulin αß and insulin like growth factor-1 αß hemi-receptors can heterodimerize to form hybrids composed of one IR αß and one IGF-1R αß. The function of hybrids in the endothelium is unclear. We sought insight by developing a small molecule capable of reducing hybrid formation in endothelial cells. METHODS: We performed a high-throughput small molecule screening, based on a homology model of the apo hybrid structure. Endothelial cells were studied using western blotting and qPCR to determine the effects of small molecules that reduced hybrid formation. RESULTS: Our studies unveil a first-in-class quinoline-containing heterocyclic small molecule that reduces hybrids by >50% in human umbilical vein endothelial cells (HUVECs) with no effects on IR or IGF-1R. This small molecule reduced expression of the negative regulatory p85α subunit of phosphatidylinositol 3-kinase, increased basal phosphorylation of the downstream target Akt and enhanced insulin/insulin-like growth factor-1 and shear stress-induced serine phosphorylation of Akt. In primary saphenous vein endothelial cells (SVEC) from patients with type 2 diabetes mellitus undergoing coronary artery bypass (CABG) surgery, hybrid receptor expression was greater than in patients without type 2 diabetes mellitus. The small molecule significantly reduced hybrid expression in SVEC from patients with type 2 diabetes mellitus. CONCLUSIONS: We identified a small molecule that decreases the formation of IR: IGF-1R hybrid receptors in human endothelial cells, without significant impact on the overall expression of IR or IGF-1R. In HUVECs, reduction of IR: IGF-1R hybrid receptors leads to an increase in insulin-induced serine phosphorylation of the critical downstream signalling kinase, Akt. The underpinning mechanism appears, at least in part to involve the attenuation of the inhibitory effect of IR: IGF-1R hybrid receptors on PI3-kinase signalling.

Whole-body insulin resistance leads to accelerated atherosclerosis: role for Nox2 NADPH oxidase.

Insulin resistance underpins the progression of type 2 diabetes mellitus and leads to a collection of risk factors for the development of atherosclerosis. Whether or not insulin resistance at a whole-body level per se leads to accelerated atherosclerosis is unclear. To answer this question, we generated atherosclerosis-prone mice with whole-body insulin resistance secondary to haploinsufficiency of the insulin receptor (IR+/-) deficient in ApoE-/- (IR+/-/ApoE-/-). IR+/-/ApoE-/- and ApoE-/- littermates had similar weight, lipids, and glucose tolerance at baseline. After 12 weeks of Western high-cholesterol diet, IR+/-/ApoE-/- had significantly more atherosclerosis in the thoracoabdominal aorta and at the level of the aortic sinus than ApoE-/- littermates. Excess Nox2 NADPH oxidase (Nox2) derived superoxide has been suggested to underpin diabetes-related atherosclerosis. In IR+/-/ApoE-/- we examined the effect of inhibiting Nox2 using genetic or pharmacological approaches on the development of atherosclerosis. To genetically delete Nox2, we generated IR+/-/ApoE-/-/Nox2-/y and to inhibit Nox2 pharmacologically, we treated IR+/-/ApoE-/- with the peptide Nox2 inhibitor gp91dstat. IR+/-/ApoE-/-/Nox2-/y had significant disruption of the aortic wall with increased thoracoabdominal atherosclerosis when compared to IR+/-/ApoE-/-/Nox2+/y littermates. Inhibition of Nox2 using gp91dstat reduced atherosclerosis in the thoracoabdominal aorta of IR+/-/ApoE-/-. Whole-body insulin resistance accelerates the development of atherosclerosis. Genetic inhibition of Nox2 leads to disruption of the aortic wall in IR+/-/ApoE-/- mice with accelerated atherosclerosis, whereas pharmacological Nox2 inhibition reduces atherosclerosis in IR+/-/ApoE-/- without disruption of the arterial wall.

Echocardiographic screening for heart failure and optimization of the care pathway for individuals with pacemakers: a randomized controlled trial.

Individuals with pacemakers are at increased risk of left ventricular systolic dysfunction (LVSD). Whether screening for and optimizing the medical management of LVSD in these individuals can improve clinical outcomes is unknown. In the present study, in a multicenter controlled trial (OPT-PACE), we randomized 1,201 patients (717 men) with a pacemaker to echocardiography screening or usual care. In the screening arm, LVSD was detected in 201 of 600 (34%) patients, who then received management in either primary care or a specialist heart failure (HF) and devices clinic. The primary outcome of the trial was the difference in a composite of time to first HF hospitalization or death. Over 31 months (interquartile range = 30-40 months), the primary outcome occurred in 106 of 600 (18%) patients receiving echocardiography screening, which was not significantly different compared with the occurrence of the primary outcome in 115 of 601 (19%) patients receiving the usual care (hazard ratio = 0.89; 95% confidence interval = 0.69, 1.17). In a prespecified, nonrandomized, exploratory analysis, patients with LVSD managed by the specialist clinic experienced the primary outcome event less frequently than those managed in primary care. The results of this trial indicate that echocardiography screening commonly identifies LVSD in individuals with pacemakers but alone does not alter outcomes. ClinicalTrials.gov registration: NCT01819662 .

Distinct, common and synergistic effects of insulin and IGF-1 receptors on healthy murine ageing.

Objective: Reduced IGF-1 signalling is an evolutionarily conserved mediator of longevity, yet the magnitude of this effect is substantially larger in organisms retaining a common insulin and IGF-1 receptor. Whether this reflects the failure to simultaneously reduce IGF-1 and insulin signalling in mammalian model systems remains unexplored, as is the associated impact on markers of healthy ageing. We set out to address these uncertainties. Methods: We compared the duration of healthy life (healthspan) in male mice with haploinsufficiency of the insulin receptor (IRKO), IGF-1 receptor (IGF-1RKO), or both (DKO), versus wildtype (WT) littermates. Cognitive performance was defined using nesting studies at 3- and 24-months of age. Brain transcriptome was characterised at 3- and 18-months of age using RNA-seq. Results: Healthspan was longer in DKO versus WT, with IRKO and IGF-1RKO being intermediate. At 2 years of age, DKO also exhibited preserved nesting behaviour in contrast with all other genotypes. Differential insulin sensitivity or weight gain during ageing did not explain the preserved healthspan of DKO, since these were comparable to IRKO littermates. Brain transcriptomics at 18 months of age revealed lower expression of canonical ageing-associated genes in DKO versus WT, although many of these findings were replicated in IRKO versus WT or IGF-1RKO vs WT. Conclusions: Reduced insulin and IGF-1 receptor expression have both common and synergistic effects upon elements of healthy mammalian ageing, suggesting future ageing studies should consider targeting both insulin and IGF-1 signalling.

Advancing the access to cardiovascular diagnosis and treatment among women with cardiovascular disease: a joint British Cardiovascular Societies' consensus document.

Despite significant progress in cardiovascular pharmacotherapy and interventional strategies, cardiovascular disease (CVD), in particular ischaemic heart disease, remains the leading cause of morbidity and mortality among women in the UK and worldwide. Women are underdiagnosed, undertreated and under-represented in clinical trials directed at management strategies for CVD, making their results less applicable to this subset. Women have additional sex-specific risk factors that put them at higher risk of future cardiovascular events. Psychosocial risk factors, socioeconomic deprivation and environmental factors have an augmented impact on women's cardiovascular health, highlighting the need for a holistic approach to care that considers risk factors specifically related to female biology alongside the traditional risk factors. Importantly, in the UK, even in the context of a National Health Service, there exist significant regional variations in age-standardised mortality rates among patients with CVD. Given most CVDs are preventable, concerted efforts are necessary to address the unmet needs and ensure parity of care for women with CVD. The present consensus document, put together by the British Cardiovascular Society (BCS)'s affiliated societies, specifically portrays the current status on the sex-related differences in the diagnosis and treatment of each of the major CVD areas and proposes strategies to overcome the barriers in accessing diagnoses and treatments among women. This document aims at raising awareness of the scale of the current problem and hopes to stimulate a multifaceted approach to address sex disparities and enable future comprehensive sex- and gender-based research through collaboration across different affiliated societies within the BCS.

Plasma MERTK is causally associated with infection mortality.

BACKGROUND: Infectious diseases are a major cause of mortality in spite of existing public health, anti-microbial and vaccine interventions. We aimed to define plasma proteomic associates of infection mortality and then apply Mendelian randomisation (MR) to yield biomarkers that may be causally associated. METHODS: We used UK Biobank plasma proteomic data to associate 2923 plasma proteins with infection mortality before 31st December 2019 (240 events in 52,520 participants). Since many plasma proteins also predict non-infection mortality, we focussed on those associated with >1.5-fold risk of infection mortality in an analysis excluding survivors. Protein quantitative trait scores (pQTS) were then used to identify whether genetically predicted protein levels also associated with infection mortality. To conduct Two Sample MR, we performed a genome-wide association study (GWAS) of infection mortality using UK Biobank participants without plasma proteomic data (n = 363,953 including 984 infection deaths). FINDINGS: After adjusting for clinical risk factors, 1142 plasma proteins were associated with risk of infection mortality (false discovery rate <0.05). 259 proteins were associated with >1.5-fold increased risk of infection versus non-infection mortality. Of these, we identified genetically predicted increasing MERTK concentration was associated with increased risk of infection mortality. MR supported a causal association between increasing plasma MERTK protein and infection mortality (odds ratio 1.46 per unit; 95% CI 1.15- 1.85; p = 0.002). CONCLUSION: Plasma MERTK is causally associated with infection mortality and warrants exploration as a potential therapeutic target.

The diabetic myocardial transcriptome reveals Erbb3 and Hspa2 as a novel biomarkers of incident heart failure.

AIMS: Diabetes mellitus (DM) increases heart failure incidence and worsens prognosis, but its molecular basis is poorly defined in humans. We aimed to define the diabetic myocardial transcriptome and validate hits in their circulating protein form to define disease mechanisms and biomarkers. METHODS AND RESULTS: RNA-sequencing data from the Genotype-Tissue Expression (GTEx) project was used to define differentially expressed genes (DEGs) in right atrial (RA) and left ventricular (LV) myocardium from people with versus without DM (type 1 or 2). DEGs were validated as plasma proteins in the UK Biobank cohort, searching for directionally concordant differential expression. Validated plasma proteins were characterized in UK Biobank participants, irrespective of diabetes status, using cardiac magnetic resonance imaging, incident heart failure and cardiovascular mortality.We found 32 and 32 DEGs associated with DM in the RA and LV, respectively, with no overlap between these. Plasma proteomic data was available for 12, with ERBB3, NRXN3 and HSPA2 (all LV hits) exhibiting directional concordance. Irrespective of DM status, lower circulating ERBB3 and higher HSPA2 were associated with impaired left ventricular contractility and higher LV mass. Participants in the lowest quartile of circulating ERBB3 or highest quartile of circulating HSPA2 had increased incident heart failure and cardiovascular death vs. all other quartiles. CONCLUSIONS: DM is characterized by lower Erbb3 and higher Hspa2 expression in the myocardium, with directionally concordant differences in their plasma protein concentration. These are associated with left ventricular dysfunction, incident heart failure and cardiovascular mortality.

Studying Adipose Endothelial Cell/Adipocyte Cross-Talk in Human Subcutaneous Adipose Tissue.

Microvascular endothelial cells (MVECs) have many critical roles, including control of vascular tone, regulation of thrombosis, and angiogenesis. Significant heterogeneity in endothelial cell (EC) genotype and phenotype depends on their vascular bed and host disease state. The ability to isolate MVECs from tissue-specific vascular beds and individual patient groups offers the opportunity to directly compare MVEC function in different disease states. Here, using subcutaneous adipose tissue (SAT) taken at the time of insertion of cardiac implantable electronic devices (CIED), we describe a method for the isolation of a pure population of functional human subcutaneous adipose tissue MVEC (hSATMVEC) and an experimental model of hSATMVEC-adipocyte cross-talk. hSATMVEC were isolated following enzymatic digestion of SAT by incubation with anti-CD31 antibody-coated magnetic beads and passage through magnetic columns. hSATMVEC were grown and passaged on gelatin-coated plates. Experiments used cells at passages 2-4. Cells maintained classic features of EC morphology until at least passage 5. Flow cytometric assessment showed 99.5% purity of isolated hSATMVEC, defined as CD31+/CD144+/CD45-. Isolated hSATMVEC from controls had a population doubling time of approximately 57 h, and active proliferation was confirmed using a cell proliferation imaging kit. Isolated hSATMVEC function was assessed using their response to insulin stimulation and angiogenic tube-forming potential. We then established an hSATMVEC-subcutaneous adipocyte co-culture model to study cellular cross-talk and demonstrated a downstream effect of hSATMVEC on adipocyte function. hSATMVEC can be isolated from SAT taken at the time of CIED insertion and are of sufficient purity to both experimentally phenotype and study hSATMVEC-adipocyte cross-talk.

Diabetes mellitus does not alter mortality or hospitalisation risk in patients with newly diagnosed heart failure with preserved ejection fraction: Time to rethink pathophysiological models of disease progression.

INTRODUCTION: Type 2 diabetes is a common and adverse prognostic co-morbidity for patients with heart failure with reduced ejection fraction (HFrEF). The effect of diabetes on long-term outcomes for heart failure with preserved ejection fraction (HFpEF) is less established. METHODS: Prospective cohort study of patients referred to a regional HF clinic with newly diagnosed with HFrEF and HFpEF according to the 2016 European Society of Cardiology guidelines. The association between diabetes, all-cause mortality and hospitalisation was quantified using Kaplan-Meier or Cox regression analysis. RESULTS: Between 1st May 2012 and 1st May 2013, of 960 unselected consecutive patients referred with suspected HF, 464 and 314 patients met the criteria for HFpEF and HFrEF respectively. Within HFpEF and HFrEF groups, patients with diabetes were more frequently male and in both groups patients with diabetes were more likely to be treated with ß-adrenoceptor antagonists and angiotensin converting enzyme inhibitors. After adjustment for age, sex, medical therapy and co-morbidities, diabetes was associated with increased mortality in individuals with HFrEF (HR 1.46 95% CI: 1.05-2.02; p = .023), but not in those with HFpEF (HR 1.26 95% CI 0.92-1.72; p = .146). CONCLUSION: In unselected patients with newly diagnosed HF, diabetes is not an adverse prognostic marker in patients with HFpEF, but is in HFrEF.

Molecular mechanisms of diabetic heart disease: Insights from transcriptomic technologies.

Over half a billion adults across the world have diabetes mellitus (DM). This has a wide-ranging impact on their health, including more than doubling their risk of major cardiovascular events, in comparison to age-sex matched individuals without DM. Notably, the risk of heart failure is particularly increased, even when coronary artery disease and hypertension are not present. Macro- and micro-vascular complications related to endothelial cell (EC) dysfunction are a systemic feature of DM and can affect the heart. However, it remains unclear to what extent these and other factors underpin myocardial dysfunction and heart failure linked with DM. Use of unbiased 'omics approaches to profile the molecular environment of the heart offers an opportunity to identify novel drivers of cardiac dysfunction in DM. Multiple transcriptomics studies have characterised the whole myocardium or isolated cardiac ECs. We present a systematic summary of relevant studies, which identifies common themes including alterations in both myocardial fatty acid metabolism and inflammation. These findings prompt further research focussed on these processes to validate potentially causal factors for prioritisation into therapeutic development pipelines.

Association Between Type 2 Diabetes and Changes in Myocardial Structure, Contractile Function, Energetics, and Blood Flow Before and After Aortic Valve Replacement in Patients With Severe Aortic Stenosis.

BACKGROUND: Type 2 diabetes (T2D) is associated with an increased risk of left ventricular dysfunction after aortic valve replacement (AVR) in patients with severe aortic stenosis (AS). Persistent impairments in myocardial energetics and myocardial blood flow (MBF) may underpin this observation. Using phosphorus magnetic resonance spectroscopy and cardiovascular magnetic resonance, this study tested the hypothesis that patients with severe AS and T2D (AS-T2D) would have impaired myocardial energetics as reflected by the phosphocreatine to ATP ratio (PCr/ATP) and vasodilator stress MBF compared with patients with AS without T2D (AS-noT2D), and that these differences would persist after AVR. METHODS: Ninety-five patients with severe AS without coronary artery disease awaiting AVR (30 AS-T2D and 65 AS-noT2D) were recruited (mean, 71 years of age [95% CI, 69, 73]; 34 [37%] women). Thirty demographically matched healthy volunteers (HVs) and 30 patients with T2D without AS (T2D controls) were controls. One month before and 6 months after AVR, cardiac PCr/ATP, adenosine stress MBF, global longitudinal strain, NT-proBNP (N-terminal pro-B-type natriuretic peptide), and 6-minute walk distance were assessed in patients with AS. T2D controls underwent identical assessments at baseline and 6-month follow-up. HVs were assessed once and did not undergo 6-minute walk testing. RESULTS: Compared with HVs, patients with AS (AS-T2D and AS-noT2D combined) showed impairment in PCr/ATP (mean [95% CI]; HVs, 2.15 [1.89, 2.34]; AS, 1.66 [1.56, 1.75]; P<0.0001) and vasodilator stress MBF (HVs, 2.11 mL min g [1.89, 2.34]; AS, 1.54 mL min g [1.41, 1.66]; P<0.0001) before AVR. Before AVR, within the AS group, patients with AS-T2D had worse PCr/ATP (AS-noT2D, 1.74 [1.62, 1.86]; AS-T2D, 1.44 [1.32, 1.56]; P=0.002) and vasodilator stress MBF (AS-noT2D, 1.67 mL min g [1.5, 1.84]; AS-T2D, 1.25 mL min g [1.22, 1.38]; P=0.001) compared with patients with AS-noT2D. Before AVR, patients with AS-T2D also had worse PCr/ATP (AS-T2D, 1.44 [1.30, 1.60]; T2D controls, 1.66 [1.56, 1.75]; P=0.04) and vasodilator stress MBF (AS-T2D, 1.25 mL min g [1.10, 1.41]; T2D controls, 1.54 mL min g [1.41, 1.66]; P=0.001) compared with T2D controls at baseline. After AVR, PCr/ATP normalized in patients with AS-noT2D, whereas patients with AS-T2D showed no improvements (AS-noT2D, 2.11 [1.79, 2.43]; AS-T2D, 1.30 [1.07, 1.53]; P=0.0006). Vasodilator stress MBF improved in both AS groups after AVR, but this remained lower in patients with AS-T2D (AS-noT2D, 1.80 mL min g [1.59, 2.0]; AS-T2D, 1.48 mL min g [1.29, 1.66]; P=0.03). There were no longer differences in PCr/ATP (AS-T2D, 1.44 [1.30, 1.60]; T2D controls, 1.51 [1.34, 1.53]; P=0.12) or vasodilator stress MBF (AS-T2D, 1.48 mL min g [1.29, 1.66]; T2D controls, 1.60 mL min g [1.34, 1.86]; P=0.82) between patients with AS-T2D after AVR and T2D controls at follow-up. Whereas global longitudinal strain, 6-minute walk distance, and NT-proBNP all improved after AVR in patients with AS-noT2D, no improvement in these assessments was observed in patients with AS-T2D. CONCLUSIONS: Among patients with severe AS, those with T2D demonstrate persistent abnormalities in myocardial PCr/ATP, vasodilator stress MBF, and cardiac contractile function after AVR; AVR effectively normalizes myocardial PCr/ATP, vasodilator stress MBF, and cardiac contractile function in patients without T2D.

Relationship Among Diabetes, Obesity, and Cardiovascular Disease Phenotypes: A UK Biobank Cohort Study.

OBJECTIVE: Obesity and diabetes frequently coexist, yet their individual contributions to cardiovascular risk remain debated. We explored cardiovascular disease biomarkers, events, and mortality in the UK Biobank stratified by BMI and diabetes. RESEARCH DESIGN AND METHODS: A total of 451,355 participants were stratified by ethnicity-specific BMI categories (normal, overweight, obese) and diabetes status. We examined cardiovascular biomarkers including carotid intima-media thickness (CIMT), arterial stiffness, left ventricular ejection fraction (LVEF), and cardiac contractility index (CCI). Poisson regression models estimated adjusted incidence rate ratios (IRRs) for myocardial infarction, ischemic stroke, and cardiovascular death, with normal-weight nondiabetes as comparator. RESULTS: Five percent of participants had diabetes (10% normal weight, 34% overweight, and 55% obese vs. 34%, 43%, and 23%, respectively, without diabetes). In the nondiabetes group, overweight/obesity was associated with higher CIMT, arterial stiffness, and CCI and lower LVEF (P < 0.005); these relationships were diminished in the diabetes group. Within BMI classes, diabetes was associated with adverse cardiovascular biomarker phenotype (P < 0.005), particularly in the normal-weight group. After 5,323,190 person-years follow-up, incident myocardial infarction, ischemic stroke, and cardiovascular mortality rose across increasing BMI categories without diabetes (P < 0.005); this was comparable in the diabetes groups (P-interaction > 0.05). Normal-weight diabetes had comparable adjusted cardiovascular mortality to obese nondiabetes (IRR 1.22 [95% CI 0.96-1.56]; P = 0.1). CONCLUSIONS: Obesity and diabetes are additively associated with adverse cardiovascular biomarkers and mortality risk. While adiposity metrics are more strongly correlated with cardiovascular biomarkers than diabetes-oriented metrics, both correlate weakly, suggesting that other factors underpin the high cardiovascular risk of normal-weight diabetes.

Independent endothelial functions of PIEZO1 and TRPV4 in hepatic portal vein and predominance of PIEZO1 in mechanical and osmotic stress.

BACKGROUND & AIMS: PIEZO1 and TRPV4 are mechanically and osmotically regulated calcium-permeable channels. The aim of this study was to determine the relevance and relationship of these channels in the contractile tone of the hepatic portal vein, which experiences mechanical and osmotic variations as it delivers blood to the liver from the intestines, gallbladder, pancreas and spleen. METHODS: Wall tension was measured in freshly dissected portal veins from adult male mice, which were genetically unmodified or modified for either a non-disruptive tag in native PIEZO1 or endothelial-specific PIEZO1 deletion. Pharmacological agents were used to activate or inhibit PIEZO1, TRPV4 and associated pathways, including Yoda1 and Yoda2 for PIEZO1 and GSK1016790A for TRPV4 agonism, respectively. RESULTS: PIEZO1 activation leads to nitric oxide synthase- and endothelium-dependent relaxation of the portal vein. TRPV4 activation causes contraction, which is also endothelium-dependent but independent of nitric oxide synthase. The TRPV4-mediated contraction is suppressed by inhibitors of phospholipase A2 and cyclooxygenases and mimicked by prostaglandin E2 , suggesting mediation by arachidonic acid metabolism. TRPV4 antagonism inhibits the effect of agonising TRPV4 but not PIEZO1. Increased wall stretch and hypo-osmolality inhibit TRPV4 responses while lacking effects on or amplifying PIEZO1 responses. CONCLUSIONS: The portal vein contains independently functioning PIEZO1 channels and TRPV4 channels in the endothelium, the pharmacological activation of which leads to opposing effects of vessel relaxation (PIEZO1) and contraction (TRPV4). In mechanical and osmotic strain, the PIEZO1 mechanism dominates. Modulators of these channels could present important new opportunities for manipulating liver perfusion and regeneration in disease and surgical procedures.

PIEZO1 and PECAM1 interact at cell-cell junctions and partner in endothelial force sensing.

Two prominent concepts for the sensing of shear stress by endothelium are the PIEZO1 channel as a mediator of mechanically activated calcium ion entry and the PECAM1 cell adhesion molecule as the apex of a triad with CDH5 and VGFR2. Here, we investigated if there is a relationship. By inserting a non-disruptive tag in native PIEZO1 of mice, we reveal in situ overlap of PIEZO1 with PECAM1. Through reconstitution and high resolution microscopy studies we show that PECAM1 interacts with PIEZO1 and directs it to cell-cell junctions. PECAM1 extracellular N-terminus is critical in this, but a C-terminal intracellular domain linked to shear stress also contributes. CDH5 similarly drives PIEZO1 to junctions but unlike PECAM1 its interaction with PIEZO1 is dynamic, increasing with shear stress. PIEZO1 does not interact with VGFR2. PIEZO1 is required in Ca2+-dependent formation of adherens junctions and associated cytoskeleton, consistent with it conferring force-dependent Ca2+ entry for junctional remodelling. The data suggest a pool of PIEZO1 at cell junctions, the coming together of PIEZO1 and PECAM1 mechanisms and intimate cooperation of PIEZO1 and adhesion molecules in tailoring junctional structure to mechanical requirement.

Guideline-directed medical therapy is similarly effective in heart failure with mildly reduced ejection fraction.

AIMS: Current guidelines recommend that disease-modifying pharmacological therapies may be considered for patients who have heart failure with mildly reduced ejection fraction (HFmrEF). We aimed to describe the characteristics, outcomes, provision of pharmacological therapies and dose-related associations with mortality risk in HFmrEF. METHODS AND RESULTS: We explored data from two prospective observational studies, which permitted the examination of the effects of pharmacological therapies across a broad spectrum of left ventricular ejection fraction (LVEF). The combined dataset consisted of 2388 unique patients, with a mean age of 73.7 ± 13.2 years of whom 1525 (63.9%) were male. LVEF ranged from 5 to 71% (mean 37.2 ± 12.8%) and 1504 (63.0%) were categorised as having reduced ejection fraction (HFrEF), 421 (17.6%) as HFmrEF and 463 (19.4%) as preserved ejection fraction (HFpEF). Patients with HFmrEF more closely resembled HFrEF than HFpEF. Adjusted all-cause mortality risk was lower in HFmrEF (hazard ratio [HR] 0.86 (95% confidence interval [CI] 0.74-0.99); p = 0.040) and in HFpEF (HR 0.61 (95% CI 0.52-0.71); p < 0.001) compared to HFrEF. Adjusted all-cause mortality risk was lower in patients with HFrEF and HFmrEF who received the highest doses of beta-blockers or renin-angiotensin inhibitors. These associations were not evident in HFpEF. Once adjusted for relevant confounders, each mg equivalent of bisoprolol (HR 0.95 [95% CI 0.91-1.00]; p = 0.047) and ramipril (HR 0.95 [95%CI 0.90-1.00]; p = 0.044) was associated with incremental reductions in mortality risk in patients with HFmrEF. CONCLUSIONS: Pharmacological therapies were associated with lower mortality risk in HFmrEF, supporting guideline recommendations which extend the indications of these agents to all patients with LVEF < 50%. HFmrEF more closely resembles HFrEF in terms of clinical characteristics and outcomes. Pharmacological therapies are associated with lower mortality risk in HFmrEF and HFrEF, but not in HFpEF.

Maternal Cardiac Changes in Women With Obesity and Gestational Diabetes Mellitus.

OBJECTIVE: We investigated if women with gestational diabetes mellitus (GDM) in the third trimester of pregnancy exhibit adverse cardiac alterations in myocardial energetics, function, or tissue characteristics. RESEARCH DESIGN AND METHODS: Thirty-eight healthy, pregnant women and 30 women with GDM were recruited. Participants underwent phosphorus MRS and cardiovascular magnetic resonance for assessment of myocardial energetics (phosphocreatine [PCr] to ATP ratio), tissue characteristics, biventricular volumes and ejection fractions, left ventricular (LV) mass, global longitudinal shortening (GLS), and mitral in-flow E-wave to A-wave ratio. RESULTS: Participants were matched for age, gestational age, and ethnicity. The following data are reported as mean ± SD. The women with GDM had higher BMI (27 ± 4 vs. 33 ± 5 kg/m2; P = 0.0001) and systolic (115 ± 11 vs. 121 ± 13 mmHg; P = 0.04) and diastolic (72 ± 7 vs. 76 ± 9 mmHg; P = 0.04) blood pressures. There was no difference in N-terminal pro-brain natriuretic peptide concentrations between the groups. The women with GDM had lower myocardial PCr to ATP ratio (2.2 ± 0.3 vs. 1.9 ± 0.4; P < 0.0001), accompanied by lower LV end-diastolic volumes (76 ± 12 vs. 67 ± 11 mL/m2; P = 0.002) and higher LV mass (90 ± 13 vs. 103 ± 18 g; P = 0.001). Although ventricular ejection fractions were similar, the GLS was reduced in women with GDM (-20% ± 3% vs. -18% ± 3%; P = 0.008). CONCLUSIONS: Despite no prior diagnosis of diabetes, women with obesity and GDM manifest impaired myocardial contractility and higher LV mass, associated with reductions in myocardial energetics in late pregnancy compared with lean women with healthy pregnancy. These findings may aid our understanding of the long-term cardiovascular risks associated with GDM.

Reduction of heart failure guideline-directed medication during hospitalization: prevalence, risk factors, and outcomes.

AIMS: Optimal management of heart failure with reduced ejection fraction (HFrEF) includes titration of guideline-directed medical therapy (GDMT) to the highest tolerated dose within the licensed range. During hospitalization, GDMT doses are often significantly altered, although it is unknown whether the cause of hospitalization influences this. METHODS AND RESULTS: We recruited 711 people with stable HFrEF from specialist heart failure clinics and prospectively assessed events occurring during first unplanned hospitalization. Dose changes of ACE inhibitors or angiotensin receptor blockers (ACEi/ARB), beta-blockers, mineralocorticoid receptor antagonists, and loop diuretics were recorded during 414 hospitalizations, categorized as due to decompensated heart failure, other cardiovascular causes, infection, or other non-cardiovascular causes. Most hospitalizations resulted in no change to GDMT. ACEi/ARB dose was reduced in 21% of hospitalizations and was more common during non-cardiovascular hospitalization (25.4% vs. 13.9%; P = 0.005). ACEi/ARB dose reduction was associated with older age and lower left ventricular ejection fraction at study recruitment, and poorer renal function, lower systolic blood pressure, higher serum potassium, and less frequent care from a cardiologist during admission. People experiencing ACEi/ARB reduction had worse age-adjusted survival after discharge, without differences in heart failure re-hospitalization. De-escalation of beta-blockers occurred in 8% of hospitalizations, most often due to other non-cardiovascular causes; this was not associated with post-discharge survival or re-hospitalization with heart failure. CONCLUSIONS: De-escalation of HFrEF GDMT is more common during non-cardiovascular hospitalization and for ACEi/ARB is associated with reduced survival. Post-discharge care plans should include robust plans to consider re-escalation of GDMT in these cases.