Dysbiosis-induced NASH was associated with cognitive impairment and a probiotic (LP EMCC-1039) supplementation has beneficial effect through modulation of TLR4/BDNF signaling pathway.
To investigate the mechanism of inflflammatory-mediated toll-like receptor 4 (TLR4)-p38 mitogen-activated protein kinase (p38 MAPK) pathway in Kupffer cells (KCs) of non-alcoholic steatohepatitis (NASH) rats and the intervention effect of soothing Gan (Liver) and invigorating Pi (Spleen) recipes on this pathway.
In conclusion, this work verified that SAR ameliorates NASH through deactivation of the hepatic LPS/TLR4 pathway and inhibition of adipocyte dysfunction.
This study aimed to define altered MS-metabolomic responses during high-fat (HF)-induced NASH that are restored by GTE utilizing livers from an earlier study in which GTE decreased endotoxin-TLR4-NFκB liver injury.
Mechanistically, we demonstrated that scoparone treatment alleviates NASH- and lipopolysaccharide (LPS)-induced immune responses in macrophages partly by blocking TLR-4/NF-κB signaling in a dose-dependent manner.
The results showed that genistein could reduce TLR4 protein and gene expression, decrease the endotoxin and TNFα, alleviate the inflammatory reaction and make the indicators detected in blood and liver stay near normal in NASH rats.
To investigate the effects of intestinal trefoil factor 3 (TFF3) on intestinal barrier function and endotoxin/toll-like receptor 4(TLR4) expression in NASH rats.
Wild-type (WT) and loss-of-function TLR4-mutant (TLR4m) mice were fed a high-fat diet containing GTE at 0 or 2% for 8 weeks before assessing NASH, NFκB-mediated inflammation, TLR4 and its adaptor proteins MyD88 and TRIF, circulating endotoxin, and intestinal tight junction protein mRNA expression.
The pathogenic basis of NAFLD progressing to NASH is currently unknown, but growing evidence suggests MD2 (myeloid differentiation factor 2), an accessory protein of TLR4, is an important signalling component contributing to this disease.
Nonetheless, there are several disease-specific molecular signaling pathways, such as differential pathway activation downstream of TLR4 (MyD88-dependence in NASH versus MyD88-independence in ASH), inflammasome activation and IL-1β signaling in ASH, insulin resistance and lipotoxicity in NASH, and dysregulation of different microRNAs, which clearly highlight that ASH and NASH are two distinct biological entities.
However, GTE in HF mice decreased biochemical and histological parameters of NASH and lowered hepatic p65 phosphorylation in association with decreased serum TNFα, mRNA expression of TNFR1 and TLR4 and MyD88 protein.
The results strongly suggest that NADPH oxidase-mediated peroxynitrite drove TLR4 recruitment into hepatic lipid rafts and inflammation, whereas the in vivo use of the peroxynitrite scavenger phenylboronic acid, a novel synthetic molecule having high reactivity with peroxynitrite, attenuates inflammatory pathogenesis in NASH.
TLR4 mRNA levels were significantly increased in subjects with NASH compared with NAFL as was interferon regulatory factor (IRF) 3 in the myeloid differentiation factor 88-independent signaling pathway.
This data constitutes the first demonstration of the upregulation of the MyD88-dependent TLR4/NFκB pathway in AH and NASH where MDBs formed, via the NFκB-CXCR4/7 pathway, and provides further insight into the mechanism of MDB formation in human liver diseases.
In this review paper, we elaborate on the pathophysiological differences between these two entities and highlight the disease-specific involvement of signaling molecules downstream of the Toll-like receptor 4, and the differential mechanism by which the inflammasome contributes to ASH versus NASH.