Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37240, USA.
Published: August 2024
AI Article Synopsis
Article Abstract
The endoplasmic reticulum (ER) comprises an array of structurally distinct subdomains, each with characteristic functions. While altered ER-associated processes are linked to age-onset pathogenesis, whether shifts in ER morphology underlie these functional changes is unclear. We report that ER remodeling is a conserved feature of the aging process in models ranging from yeast to and mammals. Focusing on as an exemplar of metazoan aging, we find that as animals age, ER mass declines in virtually all tissues and ER morphology shifts from rough sheets to tubular ER. The accompanying large-scale shifts in proteomic composition correspond to the ER turning from protein synthesis to lipid metabolism. To drive this substantial remodeling, ER-phagy is activated early in adulthood, promoting turnover of rough ER in response to rises in luminal protein-folding burden and reduced global protein synthesis. Surprisingly, ER remodeling is a pro-active and protective response during aging, as ER-phagy impairment limits lifespan in yeast and diverse lifespan-extending paradigms promote profound remodeling of ER morphology even in young animals. Altogether our results reveal ER-phagy and ER morphological dynamics as pronounced, underappreciated mechanisms of both normal aging and enhanced longevity.
Nonalcoholic fatty liver disease (NAFLD) encompasses a spectrum of chronic liver conditions, ranging from simple steatosis to nonalcoholic steatohepatitis, which may progress to fibrosis/cirrhosis. Here, the GSE163211 data set was analyzed, and Asah1 (encoding acid ceramidase) was identified as a crucial lysosomal gene that positively correlated with NAFLD stages in obese patients. To evaluate the role of Asah1 in the progression of NAFLD, Asah1/Alb mice (hepatocyte-specific deletion of Asah1) and Asah1 floxed (Asah1/wild-type) mice were fed with either a normal diet or a high-fat, high-cholesterol paigen diet (PD) for 20 weeks.
Transient receptor potential channel 1 (TRPC1) is a widely expressed mechanosensitive ion channel located within the endoplasmic reticulum membrane, crucial for refilling depleted internal calcium stores during activation of calcium-dependent signaling pathways. Here, we demonstrate that TRPC1 activity is protective within cartilage homeostasis in the prevention of cellular senescence associated cartilage breakdown during mechanical and inflammatory challenge. We reveal that TRPC1 loss is associated with early stages of osteoarthritis (OA) and plays a non-redundant role in calcium signaling in chondrocytes.
University Lyon, Université Claude Bernard Lyon 1, CNRS UMR-5261, INSERM U-1315, Institut NeuroMyoGène - Pathophysiology and Genetics of Neuron and Muscle , Lyon, France.
The potential pathogenic role of disturbed Ca2+ homeostasis in Duchenne muscular dystrophy (DMD) remains a complex, unsettled issue. We used muscle fibers isolated from 3-mo-old DMDmdx rats to further investigate the case. Most DMDmdx fibers exhibited no sign of trophic or morphology distinction as compared with WT fibers and mitochondria and t-tubule membrane networks also showed no stringent discrepancy.
Objective: Cholangiocarcinoma (CCA) presents a therapeutic challenge due to its aggressiveness and poor survival rates. This study introduces an approach using tissue inhibitor of metalloproteinase 2 (TIMP2)-enriched bone marrow mesenchymal stem cell-derived exosomes (BMSC-Exo) encapsulated in chitosan hydrogels (CS), intending to provide novel insight into the CCA treatment.
Methods: BMSC-Exo was characterized by using TEM, nanoparticle tracking analysis, and western blotting.
