Hepatic stellate cells (HSCs) are the primary fibrogenic cells in the liver, and their activation plays a crucial role in the development and progression of hepatic fibrosis. Here, we report that retinoid X receptor-alpha (RXRα), a unique member of the nuclear receptor superfamily, is a key modulator of HSC activation and liver fibrosis. RXRα exerts its effects by modulating calcium/calmodulin-dependent protein kinase kinase β (CaMKKβ)-mediated activation of AMP-activated protein kinase-alpha (AMPKα). In addition, we demonstrate that K-80003, which binds RXRα by a unique mechanism, effectively suppresses HSC activation, proliferation, and migration, thereby inhibiting liver fibrosis in the CCl₄ and amylin liver NASH (AMLN) diet animal models. The effect is mediated by AMPKα activation, promoting mitophagy in HSCs. Mechanistically, K-80003 activates AMPKα by inducing RXRα to form condensates with CaMKKβ and AMPKα via a two-phase process. The formation of RXRα condensates is driven by its N-terminal intrinsic disorder region and requires phosphorylation by CaMKKβ. Our results reveal a crucial role of RXRα in liver fibrosis regulation through modulating mitochondrial activities in HSCs. Furthermore, they suggest that K-80003 and related RXRα modulators hold promise as therapeutic agents for fibrosis-related diseases.

Ischemic stroke is a major health crisis causing high mortality and morbidity. The key treatment relies on the rapid intervention to dissolve thrombus, to reduce bleeding side effect and re-canalize clotted blood vessels using clot lysis drugs. Tissue plasminogen activator (tPA) is the only FDA-approved drug for ischemic stroke, but it has many limitations in clinical use. In recent years, the development of thrombolytic drugs and treatment strategies based on tPA has been progressed rapidly. Here we review the recent progress in this field, including the contributions from us and others, to promote the future development of novel thrombolytic drugs.
Brain Ischemia/drug therapy* ; Fibrinolytic Agents/therapeutic use* ; Humans ; Research/trends* ; Stroke/drug therapy* ; Thrombolytic Therapy/trends* ; Tissue Plasminogen Activator/therapeutic use*