PDRG1 at the interface between intermediary metabolism and oncogenesis

PDRG1 is a small oncogenic protein of 133 residues. In normal human tissues, the p53 and DNA damageregulated gene 1(PDRG1) gene exhibits maximal expression in the testis and minimal levels in the liver. Increased expression has been detected in several tumor cells and in response to genotoxic stress. High-throughput studies identified the PDRG1 protein in a variety of macromolecular complexes involved in processes that are altered in cancer cells. For example, this oncogene has been found as part of the RNA polymerase Ⅱ complex, the splicing machinery and nutrient sensing machinery, although its role in these complexes remains unclear. More recently, the PDRG1 protein was found as an interaction target for the catalytic subunits of methionine adenosyltransferases. These enzymes synthesize S-adenosylmethionine, the methyl donor for, among others, epigenetic methylations that occur on the DNA and histones. In fact, downregulation of S-adenosylmethionine synthesis is the first functional effect directly ascribed to PDRG1. The existence of global DNA hypomethylation, together with increased PDRG1 expression, in many tumor cells highlights the importance of this interaction as one of the putative underlying causes for cell transformation. Here, we will review the accumulated knowledge on this oncogene, emphasizing the numerous aspects that remain to be explored.

Exploring the effects of dietary inulin in rainbow trout fed a high‑starch,100%plant‑based diet

Background High dietary carbohydrates can spare protein in rainbow trout(Oncorhynchus mykiss)but may affect growth and health.Inulin,a prebiotic,could have nutritional and metabolic effects,along with anti-inflammatory properties in teleosts,improving growth and welfare.We tested this hypothesis in rainbow trout by feeding them a 100%plant-based diet,which is a viable alternative to fishmeal and fish oil in aquaculture feeds.In a two-factor design,we examined the impact of inulin(2%)as well as the variation in the carbohydrates(CHO)/plant protein ratio on rainbow trout.We assessed the influence of these factors on zootechnical parameters,plasma metabolites,gut microbiota,production of short-chain fatty acids and lactic acid,as well as the expression of free-fatty acid receptor genes in the mid-intestine,intermediary liver metabolism,and immune markers in a 12-week feeding trial.Results The use of 2%inulin did not significantly change the fish intestinal microbiota,but interestingly,the high CHO/protein ratio group showed a change in intestinal microbiota and in particular the beta diversity,with 21 bacterial genera affected,including Ralstonia,Bacillus,and 11 lactic-acid producing bacteria.There were higher levels of butyric,and valeric acid in groups fed with high CHO/protein diet but not with inulin.The high CHO/protein group showed a decrease in the expression of pro-inflammatory cytokines(il1b,il8,and tnfa)in liver and a lower expression of the genes coding for tight-junction proteins in mid-intestine(tjp1a and tjp3).However,the 2%inulin did not modify the expression of plasma immune markers.Finally,inulin induced a negative effect on rainbow trout growth performance irrespective of the dietary carbohydrates.Conclusions With a 100%plant-based diet,inclusion of high levels of carbohydrates could be a promising way for fish nutrition in aquaculture through a protein sparing effect whereas the supplementation of 2%inulin does not appear to improve the use of CHO when combined with a 100%plant-based diet.

Pipeline of New Drug Treatment for Non-alcoholic Fatty Liver Disease/Metabolic Dysfunction-associated Steatotic Liver Disease

Given the global prevalence and rising incidence of metabolic dysfunction-associated steatotic liver disease(MASLD),the absence of licensed medications is striking.A deeper understanding of the heterogeneous nature of MASLD has recently contributed to the discovery of novel groups of agents and the potential repurposing of currently available medications.MASLD therapies center on four major pathways.Considering the close relationship between MASLD and type 2 diabetes,the first approach involves antidiabetic medications,including incretins,thiazolidinedione insulin sensitizers,and sodium-glucose cotransporter 2 inhibitors.The second approach targets hepatic lipid accumulation and the resultant metabolic stress.Agents in this group include peroxisome proliferatoractivated receptor agonists(e.g.,pioglitazone,elafibranor,saroglitazar),bile acid-farnesoid X receptor axis regulators(obeticholic acid),de novo lipogenesis inhibitors(aramchol,NDI-010976),and fibroblast growth factor 21/19 analogs.The third approach focuses on targeting oxidative stress,inflammation,and fibrosis.Agents in this group include antioxi-dants(vitamin E),tumor necrosis factor a pathway regulators(emricasan,pentoxifylline,ZSP1601),and immune modulators(cenicriviroc,belapectin).The final group targets the gut(IMM-124e,solithromycin).Combination therapies targeting different pathogenetic pathways may provide an alternative to MASLD treatment with higher efficacy and fewer side effects.This review aimed to provide an update on these medications.

Supplying the trip to antibody production-nutrients,signaling,and the programming of cellular metabolism in the mature B lineage

The COVID pandemic has refreshed and expanded recognition of the vital role that sustained antibody(Ab)secretion plays in our immune defenses against microbes and of the importance of vaccines that elicit Ab protection against infection.With this backdrop,it is especially timely to review aspects of the molecular programming that govern how the cells that secrete Abs arise,persist,and meet the challenge of secreting vast amounts of these glycoproteins.Whereas plasmablasts and plasma cells(PCs)are the primary sources of secreted Abs,the process leading to the existence of these cell types starts with naive B lymphocytes that proliferate and differentiate toward several potential fates.At each step,cells reside in specific microenvironments in which they not only receive signals from cytokines and other cell surface receptors but also draw on the interstitium for nutrients.Nutrients in turn influence flux through intermediary metabolism and sensor enzymes that regulate gene transcription,translation,and metabolism.This review will focus on nutrient supply and how sensor mechanisms influence distinct cellular stages that lead to PCs and their adaptations as factories dedicated to Ab secretion.Salient findings of this group and others,sometimes exhibiting differences,will be summarized with regard to the journey to a distinctive metabolic program in PCs.