Russeting in apple is initiated after exposure to moisture ends: Molecular and biochemical evidence

Exposure of the fruit surface to moisture during early development is causal in russeting of apple (Malus × domestica Borkh.). Moisture exposure results in formation of microcracks and de-creased cuticle thickness. Periderm differentiation begins in the hypodermis, but only after discon-tinuation of moisture exposure. Expressions of selected genes involved in cutin, wax and suberin synthesis were quantified, as were the wax, cutin and suberin compositions. Experiments were con-ducted in two phases. In Phase I (31 days after full bloom) the fruit surface was exposed to moisture for 6 or 12 d. Phase II was after moisture exposure had been discontinued. Unexposed areas on the same fruit served as unexposed controls. During Phase I, cutin and wax synthesis genes were down-regulated only in the moisture-exposed patches. During Phase II, suberin synthesis genes were up-regulated only in the moisture-exposed patches. The expressions of cutin and wax genes in the moisture-exposed patches increased slightly during Phase II, but the levels of expression were much lower than in the control patches. Amounts and compositions of cutin, wax and suberin were con-sistent with the gene expressions. Thus, moisture-induced russet is a two-step process: moisture exposure reduces cutin and wax synthesis, moisture removal triggers suberin synthesis. © 2020 by the authors. Licensee MDPI, Basel, Switzerland

Membrane-anchored calpains – hidden regulators of growth and development beyond plants?

Calpains are modulatory proteases that modify diverse cellular substrates and play essential roles in eukaryots. The best studied are animal cytosolic calpains. Here, we focus on enigmatic membrane-anchored calpains, their structural and functional features as well as phylogenetic distribution. Based on domain composition, we identified four types of membrane-anchored calpains. Type 1 and 2 show broad phylogenetic distribution among unicellular protists and streptophytes suggesting their ancient evolutionary origin. Type 3 and 4 diversified early and are present in brown algae and oomycetes. The plant DEK1 protein is the only representative of membrane-anchored calpains that has been functionally studied. Here, we present up to date knowledge about its structural features, putative regulation, posttranslational modifications, and biological role. Finally, we discuss potential model organisms and available tools for functional studies of membrane-anchored calpains with yet unknown biological role. Mechanistic understanding of membrane-anchored calpains may provide important insights into fundamental principles of cell polarization, cell fate control, and morphogenesis beyond plants

Metabolic causes of liver disease among adults living with HIV from low- and middle-income countries: a cross-sectional study.

INTRODUCTION Liver disease is a leading cause of morbidity and mortality among persons living with HIV (PLHIV). While chronic viral hepatitis has been extensively studied in low- and middle-income countries (LMICs), there is limited information about the burden of metabolic disorders on liver disease in PLHIV. METHODS We conducted a cross-sectional analysis of baseline data collected between October 2020 and July 2022 from the IeDEA-Sentinel Research Network, a prospective cohort enrolling PLHIV ≥40 years on antiretroviral treatment (ART) for ≥6 months from eight clinics in Asia, Americas, and central, East, southern and West Africa. Clinical assessments, laboratory testing on fasting blood samples and liver stiffness measurement (LSM)/controlled attenuation parameter (CAP) by vibration-controlled transient elastography were performed. Multivariable logistic regression models assessed factors associated with liver fibrosis (LSM ≥7.1 kPa) and steatosis (CAP ≥248 dB/m). Population attributable fraction (PAF) of each variable associated with significant liver fibrosis was estimated using Levin's formula. RESULTS Overall, 2120 PLHIV (56% female, median age 50 [interquartile range: 45-56] years) were included. The prevalence of obesity was 19%, 12% had type 2 diabetes mellitus (T2DM), 29% had hypertension and 53% had dyslipidaemia. The overall prevalence of liver fibrosis and steatosis was 7.6% (95% confidence interval [CI] 6.1-8.4) and 28.4% (95% CI 26.5-30.7), respectively, with regional variability. Male sex at birth (odds ratio [OR] 1.62, CI 1.10-2.40), overweight/obesity (OR = 2.50, 95% CI 1.69-3.75), T2DM (OR 2.26, 95% CI 1.46-3.47) and prolonged exposure to didanosine (OR 3.13, 95% CI 1.46-6.49) were associated with liver fibrosis. Overweight/obesity and T2DM accounted for 42% and 11% of the PAF for liver fibrosis, while HBsAg and anti-HCV accounted for 3% and 1%, respectively. Factors associated with steatosis included overweight/obesity (OR 4.25, 95% CI 3.29-5.51), T2DM (OR 2.06, 95% CI 1.47-2.88), prolonged exposure to stavudine (OR 1.69, 95% CI 1.27-2.26) and dyslipidaemia (OR 1.68, 95% CI 1.31-2.16). CONCLUSIONS Metabolic disorders were significant risk factors for liver disease among PLHIV in LMICs. Early recognition of metabolic disorders risk factors might be helpful to guide clinical and lifestyle interventions. Further prospective studies are needed to determine the causative natures of these findings