Probiotic‐derived nanoparticles inhibit ALD through intestinal miR194 suppression and subsequent FXR activation

Abstract

Background and Aims: Intestinal farnesoid X receptor (FXR) plays a critical role in alcohol‐associated liver disease (ALD). We aimed to investigate whether alcohol‐induced dysbiosis increased intestinal microRNA194 (miR194) that suppressed Fxr transcription and whether Lactobacillus rhamnosus GG–derived exosome‐like nanoparticles (LDNPs) protected against ALD through regulation of intestinal miR194‐FXR signaling in mice. Approach and Results: Binge‐on‐chronic alcohol exposure mouse model was utilized. In addition to the decreased ligand‐mediated FXR activation, alcohol feeding repressed intestinal Fxr transcription and increased miR194 expression. This transcriptional suppression of Fxr by miR194 was confirmed in intestinal epithelial Caco‐2 cells and mouse enteriods. The alcohol feeding–reduced intestinal FXR activation was further demonstrated by the reduced FXR reporter activity in fecal samples and by the decreased fibroblast growth factor 15 (Fgf15) messenger RNA (mRNA) in intestine and protein levels in the serum, which caused an increased hepatic bile acid synthesis and lipogeneses. We further demonstrated that alcohol feeding increased‐miR194 expression was mediated by taurine‐upregulated gene 1 (Tug1) through gut microbiota regulation of taurine metabolism. Importantly, 3‐day oral administration of LDNPs increased bile salt hydrolase (BSH)‐harboring bacteria that decreased conjugated bile acids and increased gut taurine concentration, which upregulated Tug1, leading to a suppression of intestinal miR194 expression and recovery of FXR activation. Activated FXR upregulated FGF15 signaling and subsequently reduced hepatic bile acid synthesis and lipogenesis and attenuated ALD. These protective effects of LDNPs were eliminated in intestinal Fxr ΔIEC and Fgf15 −/− mice. We further showed that miR194 was upregulated, whereas BSH activity and taurine levels were decreased in fecal samples of patients with ALD. Conclusions: Our results demonstrated that gut microbiota–mediated miR194 regulation contributes to ALD pathogenesis and to the protective effects of LDNPs through modulating intestinal FXR signaling.

High performance anion exchange chromatography purification of probiotic bacterial extracellular vesicles enhances purity and anti‐inflammatory efficacy

“…From the data in Figure 3, we conclude that (i) HPAEC in tandem with TFF is superior to size‐based methods alone in eliminating coisolated flagellin impurities in EcN, and (ii) pH adjustment in HPAEC is a potential approach for separation of EcN BEVs from negatively charged protein impurities. To test whether HPAEC could be applied to enrichment of BEVs beyond EcN, we used Gram‐positive LAB probiotics L. casei , L. reuteri , and L. rhamnosus as BEV producers, all of which have well‐characterized BEV efficacy in a variety of diseases (Behzadi et al, 2017; Choi et al, 2020; Jiang et al, 2022; Tong et al, 2021). Purification of BEVs from Gram‐positive bacteria is complicated in that there are 10−100‐fold lower BEV yields and greater numbers of proteins secreted when compared to Gram‐negative bacteria (Dean et al, 2019).…”

Micro Trojan horses: Engineering extracellular vesicles crossing biological barriers for drug delivery

“…On the other hand, vesicles originating from the intestinal flora have been found to have beneficial effects. For example, they have been shown to alleviate alcohol‐induced liver injury by reducing the expression of miR194 in patients with alcoholic liver disease (ALD) 152 . Bacteroides polymorpha‐derived EVs can also pass through the intestinal epithelial barrier to induce the production of immunomodulatory IL‐10 in DC cells, thereby maintaining the stability of the intestinal environment 153 .…”

High performance anion exchange chromatography purification of probiotic bacterial extracellular vesicles enhances purity and anti-inflammatory efficacy

“…From the data in Figure 3, we conclude that i) HPAEC in tandem with TFF is superior to sizebased methods alone in eliminating co-isolated flagellin impurities in EcN, and ii) pH adjustment in HPAEC is a potential approach for separation of EcN BEVs from negatively charged protein impurities. To test whether HPAEC could be applied to enrichment of BEVs beyond EcN, we used Gram positive lactic acid bacteria probiotics L. casei, L. reuteri, and L. rhamnosus as BEV producers, all of which have well-characterized BEV efficacy in a variety of diseases [24][25][26][27] .…”