Lipopolysaccharide-activated Kupffer cell signaling pathway (LPS-KC signaling)

The Lipopolysaccharide (LPS)-activated Kupffer cell signaling pathway is a primary driver of the hepatic innate immune response to Gram-negative bacterial endotoxins. Kupffer cells, which are resident macrophages in the liver sinusoids, detect LPS via the Toll-like receptor 4 (TLR4) complex, involving co-receptors CD14 and MD-2 (Dixon et al., 2013, PubMed: 23314806). Activation of this pathway triggers intracellular signaling cascades, notably the MyD88-dependent and TRIF-dependent pathways, which culminate in the activation of NF-kappaB and mitogen-activated protein kinases (MAPKs) (Su et al., 2002, PubMed: 12117104). These events lead to the secretion of potent pro-inflammatory mediators, including TNF-alpha, IL-1beta, and reactive oxygen species, which are intended to neutralize pathogens but can cause significant collateral tissue damage (Roberts et al., 2007, PubMed: 17448576).\n\nDysregulation or chronic overactivation of this pathway is implicated in the progression of various liver pathologies, such as alcoholic liver disease, non-alcoholic fatty liver disease (NAFLD), and sepsis-induced liver failure (Tilg et al., 2016, PubMed: 27060403). Pharmacological intervention targeting this pathway, such as TLR4 antagonists or LPS neutralizers, aims to reduce hepatic inflammation and prevent the transition from simple steatosis to advanced fibrosis (Wang et al., 2021, PubMed: 33854442). Therapeutic challenges include maintaining sufficient immune vigilance against systemic infections while suppressing localized hepatic inflammation. Monitoring biomarkers like circulating TNF-alpha and soluble CD14 can help assess the activation state of this pathway in clinical settings.

Other names

LPS-induced Kupffer cell activationTLR4 signaling in hepatic macrophagesEndotoxin-induced Kupffer cell signalingToll-like receptor 4 signaling pathway

Inhibition of TLR4 receptor complex activation, neutralization of circulating lipopolysaccharide, or suppression of downstream pro-inflammatory cytokine transcription and release.