MASID, A. | bioRxiv Science

bioRxiv2022

AUF-1 knock down in mice overarches butyrate driven hypo-cholesteraemia by conjuring AUF-1-Dicer-1-miR122 hierarchy

This discourse probes the mechanistic molecular details of butyrate action in maintaining host-cholesterol balance. Hepatic miR122 being the most indispensable regulator of cholesterol metabolic enzymes, we studied upstream players of miR122 biogenesis in the presence and absence of butyrate in Huh7 cells and mice model. We showed that butyrate treatment caused upregulation of RNA-binding protein, AUF-1 resulting in RNase-III nuclease, Dicer-1 instability, and significant diminution of miR122. We proved its importance of AUF-1 and sequential downstream players in AUF-1-knock-down mice. We synthesized unique self-transfecting GMO (guanidinium-morpholino-oligonucleotides) linked PMO (Phosphorodiamidate-Morpholino Oligonucleotides)-based antisense reagent and injection of which in mouse caused near absence of AUF-1 coupled with increased Dicer-1 and miR122, and reduced serum cholesterol regardless of butyrate treatment indicating that butyrate acts though AUF-1. The roster of intracellular players was as follows: AUF-1-Dicer-1-miR122 for triggering butyrate driven hypocholesterlaemia. To our knowledge this is the first report linking AUF-1 with cholesterol biogenesis.

systems biology↗

bioRxiv2022

Prenatal arsenic exposure stymies gut butyrate production and enhances gut permeability in post natal life even in absence of arsenic deftly through miR122-Occludin pathway.

This discourse attempts to capture a few important dimensions of gut physiology like microbial homeostasis, short chain fatty acid (SCFA) production, occludin expression and gut permeability in post-natal life of mice those received arsenic only during pre-natal life (pAs-mice). The pAs-mice showed a striking reduction in Firmicutes to Bacteroidetes (F/B) ratio coupled with decrease in tight junction protein, occludin resulting in increase in gut permeability, increased infiltration of inflammatory cells in the colon and decrease in common SCFAs in which butyrate reduction was quite prominent in fecal samples as compared to normal control. The above phenotypes of pAs-mice were mostly reversed by supplementing butyrate with food. The talismanic ability of butyrate in enhancing occludin expression, in particular, was dissected further. As miR122 causes degradation of Occludin mRNA, we transiently overexpressed miR122 by injecting appropriate plasmids and showed reversal of butyrate effects in pAs-mice. Thus, pre-natal arsenic exposure orchestrates variety of effects by decreasing in butyrate in pAs-mice leading to increased permeability due to reduced occludin expression. Our research adds a new dimension to our understanding that pre-natal arsenic exposure imprints in post-natal life while there was no further arsenic exposure. HighlightsO_LIPrenatal Arsenic exposure decreases prevalence of butyrate producing bacteria and butyrate production in gut. C_LIO_LILack of butyrate production in the gut is responsible for increased permeability and decreased occludin expression. C_LIO_LIOral supplementation with butyrate reverses the prenatal arsenic induced changes in the gut. C_LIO_LIButyrate increases Occludin gene expression by downregulating miR122 in the gut. C_LI

pharmacology and toxicology↗