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Sahu, B. S.

Publications and source records attributed to Sahu, B. S..

2 recordsLinked to original sources

Sida cordifolia, a medicinal plant is efficacious in models of Huntingtons disease, by reducing ER stress

Background and aimHuntingtons Disease is a severe neurodegenerative disorder caused by misfolded mutant huntingtin proteins with expanded stretches of polyglutamines aggregating and destroying cells in the nervous system. Sida cordifolia and Acorus calamus are medicinal plants used in traditional Ayurvedic medicine to treat neurological disorders. Here, we tested the effectiveness of extracts of both medicinal plants in decreasing aggregation of mutant huntingtin protein in models of Huntingtons Disease and explored the mode of action. Experimental procedureWe used two models, the nematode Caenorhabditis elegans and a transgenic mouse neuroblastoma cell line, both expressing mutant huntingtin proteins with elongated polyglutamines. We assessed the effect of Sida cordifolia and Acorus calamus on mutant huntingtin protein aggregation in both models, and additionally used the cell line for mechanistic studies to identify cellular pathways underlying the effects of treatment. Results and conclusionHere, we show that an extract of Sida cordifolia inhibits aggregation of mutant huntingtin proteins. In the C. elegans model, the extract prolonged life span and improved motility of the nematode by reducing aggregation of the mutant huntingtin protein. Acorus calamus did not exhibit these effects. In the transgenic mouse neuroblastoma cell line, the extract decreased aggregation of the mutant huntingtin protein by suppressing key pathways in the ER stress response caused by the mutant protein. Our results highlight the potential therapeutic value of Sida cordifolia and its promise as a source for novel medications. HighlightsO_LISida cordifolia extract reduces aggregates in HD model of transgenic worms C_LIO_LIReduction in aggregates leads to improved motility and longevity C_LIO_LISida cordifolia extract reduces ER stress in cells expressing mHTT protein C_LIO_LIFirst report on the pharmacology of Sida cordifolia in neurodegeneration C_LI

pharmacology and toxicology↗

Mild ER Stress Impedes Regulated Secretion By Governing Key Exocytotic and granulogenic Molecular Switches

Dense core vesicles (DCVs) and synaptic vesicles (SVs) are specialised secretory vesicles (SSVs) in neurons/neuroendocrine cells harbouring cargo whose abnormal release is associated with pathophysiology. Endoplasmic Reticulum (ER) stress and inter-organellar communication are also associated with disease biology. In pursuit of investigating the cell physiological consequences arising from the crosstalk of a stressed ER and DCVs, ER stress was modelled in PC12 neuroendocrine cells using Thapsigargin (Tg). DCV exocytosis was severely compromised in ER-stressed PC12 cells, reversed by Docosahexaenoic acid (DHA). Experiments with Tunicamycin(Tm), an independent ER stressor, yielded similar results. Concurrently, ER stress caused impaired DCV exocytosis also in INS-1 cells. Molecular analysis revealed blunted SNAP25 expression, potentially attributed to augmented levels of ATF4 (a well-known CREB inhibitor) and its transcriptional regulator CREB (also known to regulate key granulogenic players Chromogranin A, Secretogranin II). Our studies revealed severe defects in DCV exocytosis in ER-stressed cells for the first time, mediated by reduced levels of key exocytotic and granulogenic switches regulated via the CREB/ATF4/eIF2 axis.

cell biology↗