JEWJITSU PEPTIDES News Roundup: fungal lipids, Nesprin‑1 in heart failure, and a nutrient‑sensitive enterokine

The first report isolated two novel fungal lipids, lentinoside A and lentinamide A, along with stearic acid, ergosterol, ergosterol endoperoxide and asperglaucide from Lentinus sajor‑caju. The authors evaluated antioxidant capacity using DPPH, ABTS and FRAP assays. In DPPH the extract and one compound showed modest radical scavenging (reported percentages and IC50 values in the source). In ABTS and FRAP assays different compounds ranked highest (values reported for compounds 4, 5, 6). The paper frames these results as expanding chemical diversity and suggesting nutraceutical potential, while the data are limited to in vitro antioxidant assays and chemical characterization and do not address safety, bioavailability or effects in organisms.

The second study used a mouse model of isoproterenol (ISO)‑induced heart failure to probe Nesprin‑1 biology. HF was induced with daily ISO injections and validated by echocardiography (LVDd, LVDs, EF, FS), gross and histological assessment, and BNP expression. The model exhibited increased body/heart weight, cardiomyocyte area, ventricular dilation and reduced EF/FS. Nesprin‑1 expression was significantly downregulated with altered nuclear membrane localization and measurable nuclear morphological distortions; concurrent findings included elevated MDA, reduced SOD, decreased Connexin‑43, increased DNA damage markers (γH2AX, 53BP1), epigenetic changes (H3K9me3, H3K27me3) and ERK hyperactivation. The authors link Nesprin‑1 downregulation to these alterations in this ISO model, but extrapolation beyond this experimental system requires caution.

The third paper identifies the peptide Limostatin as an enterokine in Drosophila larvae that coordinates developmental plasticity under amino‑acid restriction. Limostatin is produced by a subset of midgut enteroendocrine cells and acts systemically to inhibit dIlp2 expression and release from insulin‑producing neuroendocrine cells. Its expression is triggered by reduced amino acids via a fat‑body to brain relay, and it participates in a feedback loop that slows developmental progression to preserve viability under nutrient stress. The authors propose Limostatin expands the concept of decretins and suggest enterokine‑mediated regulation of IGF signaling may be an evolutionarily conserved or convergent strategy; these conclusions are based on larval Drosophila experiments and do not directly establish conservation in other species.