Double-Negative T Cells Regulate Hepatic Stellate Cell Activation to Promote Liver Fibrosis Progression via NLRP3

The Roles of T Cells in the Development of Metabolic Dysfunction-Associated Steatohepatitis

Metabolic dysfunction-associated steatohepatitis (MASH), the progressed period of metabolic dysfunction-associated steatotic liver disease (MASLD), is a multifaceted liver disease characterised by inflammation and fibrosis that develops from simple steatosis, even contributing to hepatocellular carcinoma and death. MASH involves several immune cell-mediated inflammation and fibrosis, where T cells play a crucial role through the release of pro-inflammatory cytokines and pro-fibrotic factors. This review discusses the complex role of various T cell subsets in the pathogenesis of MASH and highlights the progress of ongoing clinical trials involving T cell-targeted MASH therapies.

Unraveling the Emerging Niche Role of Hepatic Stellate Cell-derived Exosomes in Liver Diseases

Hepatic stellate cells (HSCs) play an essential role in various liver diseases, and exosomes are critical mediators of intercellular communication in local and distant microenvironments. Cellular crosstalk between HSCs and surrounding multiple tissue-resident cells promotes or inhibits the activation of HSCs. Substantial evidence has revealed that HSC-derived exosomes are involved in the occurrence and development of liver diseases through the regulation of retinoid metabolism, lipid metabolism, glucose metabolism, protein metabolism, and mitochondrial metabolism. HSC-derived exosomes are underpinned by vehicle molecules, such as mRNAs and microRNAs, that function in, and significantly affect, the processes of various liver diseases, such as acute liver injury, alcoholic liver disease, nonalcoholic fatty liver disease, viral hepatitis, fibrosis, and cancer. As such, numerous exosomes derived from HSCs or HSC-associated exosomes have attracted attention because of their biological roles and translational applications as potential targets for therapeutic targets. Herein, we review the pathophysiological and metabolic processes associated with HSC-derived exosomes, their roles in various liver diseases and their potential clinical application.

Double-negative T cells mediate M1 polarization of microglial cells via TNF-α-NLRP3 to aggravate neuroinflammation and cognitive impairment in Alzheimer's disease mice

We mainly study the role and regulatory mechanism of double-negative T cells (DNTs) in Alzheimer's disease (AD). The mice splenic DNTs were separated and amplified by Rosettesep antibody adsorption method and Easysep magnetic activated cell sorting. DNTs were intraperitoneally injected into the APP/PS1-AD mice model, which was found to aggravate cognitive impairment in mice. DNTs secreted tumor necrosis factor α (TNF-α) to promote the activation of NLRP3 and the M1 polarization of microglial cells, and silencing NLRP3 with small interfering RNA (siRNA) suppressed the effect of DNTs. DNTs were later cocultured with mice microglial cell line BV2, then fluorescence staining was conducted to detect NLRP3 expression, and enzyme-linked immunoassay was performed to measure the expression of inflammatory factors. Moreover, the levels of NLRP3, ASC, and TNFR1 proteins were detected by western-blot assay, and the proportion of F4/80 + CD11b + M1 cells was detected by flow cytometry. DNTs promoted the M1 polarization of BV2 cells and the activation of NLRP3 inflammasome. After treatment of BV2 cells with NLRP3 inhibitor, the effect of DNTs was weakened. Later, TNF-α siRNA was transfected into DNTs, and it was found that DNTs with TNF-α silencing had markedly weakened polarization effect on BV2 cells. We discovered that the proportion of DNTs increased in AD patients. DNTs secreted TNF-α to regulate the activation of NLRP3 inflammasome and the M1 polarization of microglial cells, thus promoting the central inflammatory response and aggravating the cognitive impairment in AD mice.