The legacy of terrestrial plant evolution on cell wall fine structure.

The evolution of land flora was an epochal event in the history of planet Earth. The success of plants, and especially flowering plants, in colonizing all but the most hostile environments required multiple mechanisms of adaptation. The mainly polysaccharide-based cell walls of flowering plants, which are indispensable for water transport and structural support, are one of the most important adaptations to life on land. Thus, development of vasculature is regarded as a seminal event in cell wall evolution, but the impact of further refinements and diversification of cell wall compositions and architectures on radiation of flowering plant families is less well understood. We approached this from a glyco-profiling perspective and, using carbohydrate microarrays and monoclonal antibodies, studied the cell walls of 287 plant species selected to represent important evolutionary dichotomies and adaptation to a variety of habitats. The results support the conclusion that radiation of flowering plant families was indeed accompanied by changes in cell wall fine structure and that these changes can obscure earlier evolutionary events. Convergent cell wall adaptations identified by our analyses do not appear to be associated with plants with similar lifestyles but that are taxonomically distantly related. We conclude that cell wall structure is linked to phylogeny more strongly than to habitat or lifestyle and propose that there are many approaches of adaptation to any given ecological niche.

Effect on cardiac function among patients with type 2 diabetes following high-dose mineralocorticoid receptor antagonist using echocardiography; data from the MIRAD randomized clinical trial.

BACKGROUND: Early heart failure prevention is central in patients with type 2 diabetes, and mineralocorticoid receptor antagonists (MRAs) have shown to improve prognosis. We investigated the effect of high-dose MRA, eplerenone, on cardiac function and structure in patients with type 2 diabetes and established or increased risk of cardiovascular disease but without heart failure. METHODS: In the current randomized, placebo-controlled clinical trial, 140 patients with high-risk type 2 diabetes were randomized to high-dose eplerenone (100-200 mg daily) or placebo as add-on to standard care for 26 weeks. Left ventricular systolic and diastolic function, indexed left ventricular mass (LVMi), and global longitudinal strain (GLS) were assessed using echocardiography at baseline and after 26 weeks of treatment. RESULTS: Of the included patients, 138 (99%) had an echocardiography performed at least once. Baseline early diastolic in-flow velocity (E-wave) indexed by mitral annulus velocity (e') was mean (SD) 11.1 (0.5), with 31% of patients reaching above 12. No effect of treatment on diastolic function was observed measured by E/e' (0.0, 95%CI [-1.2 to 1.2], P = 0.992) or E/A (-0.1, 95%CI [-0.2 to 0.0], P = 0.191). Mean left ventricular ejection fraction (LVEF) at baseline was 59.0% (8.0). No improvement in systolic function was observed when comparing groups after 26 weeks (LVEF: 0.9, 95%CI [-1.1 to 2.8], P = 0.382; GLS: -0.4%, 95%CI [-1.5 to 0.6], P = 0.422), nor in LVMi (-3.8 g/m2 95%CI [-10.2 to 2.7], P = 0.246). CONCLUSION: In the present echo sub-study, no change in left ventricular function was observed following high-dose MRA therapy in patients with type 2 diabetes when evaluated by conventional echocardiography. TRIAL REGISTRATION: Date of registration 25/08/2015 (EudraCT number: 2015-002,519-14).

Mineralocorticoid Receptor Antagonist Improves Cardiac Structure in Type 2 Diabetes: Data From the MIRAD Trial.

OBJECTIVES: This study investigated the impact of the MR antagonist (MRA) eplerenone on LVM in type 2 diabetes patients at high risk for cardiovascular disease (CVD). BACKGROUND: MRA activation is associated with cardiac fibrosis and increased left ventricular mass (LVM), which is an independent predictor of adverse CVD, including heart failure in patients with type 2 diabetes. METHODS: A prespecified analysis of secondary endpoints in a randomized, double-blinded clinical trial of 140 patients with type 2 diabetes at high risk of or established CVD. Patients were randomized to receive high-dose eplerenone therapy (100 mg-200 mg) or placebo as an add-on to standard care for 26 weeks. Indexed LVM (LVMi) and T1 time were measured using cardiac magnetic resonance (CMR) imaging. Biomarkers included N-terminal pro-B-type natriuretic peptide (NT-proBNP), pro-collagen type I N-terminal propeptide (P1NP), and type III N-terminal propeptide (P3NP). RESULTS: Of 140 patients in the MIRAD trial, 104 patients were subject to CMR imaging (eplerenone: 54 patients; placebo: 50 patients). Mean LVMi at baseline was 74.2 ± 16 g/m2. The treatment effect (ie, between-group differences) was a decrease of 3.7 g/m2 following the eplerenone treatment (95% CI: -6.7 to -0.7; P = 0.017), with a corresponding decrease in absolute LVM. Plasma NT-proBNP concentrations decreased by 22% (P = 0.017) using eplerenone compared with placebo, and P1NP decreased 3.3 ng/mL (P = 0.019). No differences in T1 times or P3NP concentrations were observed between groups. CONCLUSIONS: The addition of high-dose eplerenone in high-risk type 2 diabetes was associated with a clear reduction in LVMi and in NT-proBNP and P1NP levels, which may suggest a clinical benefit in heart failure prevention. (EU Clinical trials: Mineralocorticoid Receptor Antagonists in Type 2 Diabetes [MIRAD]; 2015-002519-14).

Effect of high-dose mineralocorticoid receptor antagonist eplerenone on urinary albumin excretion in patients with type 2 diabetes and high cardiovascular risk: Data from the MIRAD trial.

AIM: As mineralocorticoid receptor antagonists (MRAs) may possess renoprotective effects in type 2 diabetes (T2D), it was decided to investigate the impact of high-dose MRA on prespecified secondary endpoints-namely, change in urinary albumin-creatinine ratio (UACR) and 24-h ambulatory blood pressure-in the MIRAD trial. METHODS: This was a double-blind clinical trial in which T2D patients at high risk of or with established cardiovascular disease (CVD) were randomized to either high-dose (100-200 mg) eplerenone or a dose-matched placebo as an add-on to background antihypertensive treatment for 26 weeks. Safety was evaluated by the incidence of hyperkalaemia and kidney-related adverse events. RESULTS: A total of 140 patients were enrolled (70 in each group). Baseline UACR was 17 mg/g (geometric mean; 95% CI: 13-22); this decreased by 34% in the eplerenone group compared with the placebo group at week 26 (95% CI: -51% to -12%; P = 0.005). There was no significant decrease in 24-h systolic blood pressure (SBP) due to treatment (-3 mmHg; 95% CI: -6 to 1; P = 0.150). However, the observed change in 24-h SBP correlated with the relative change in UACR in the eplerenone group (r = 0.568, P < 0.001). Mean baseline (± SD) estimated glomerular filtration rate (eGFR) was 85 (± 18.6) mL/min/1.73 m2, and 12 (± 9%) had an eGFR of 41-59 mL/min/1.73 m2. No significant differences in the incidence of mild hyperkalaemia (≥ 5.5 mmol/L; eplerenone vs placebo: 6 vs 2, respectively; P = 0.276) and no severe hyperkalaemia (≥ 6.0 mmol/L) were observed. CONCLUSION: The addition of high-dose eplerenone to T2D patients at high risk of CVD can markedly reduce UACR with an acceptable safety profile.