Lipotoxicity-induced endotheliopathy in metabolic dysfunction-associated steatohepatitis (MASH)
Lipotoxicity-induced endotheliopathy in metabolic dysfunction-associated steatohepatitis (MASH)
This thesis of Qianqian Guo shows that in MASH (metabolic dysfunction–associated steatohepatitis), the build-up of harmful fats does more than injure liver cells. It also directly harms the thin layer of cells that line the liver sinusoids (liver sinusoidal endothelial cells, or LSECs). This type of fat-related injury is called lipotoxic endotheliopathy. When LSECs are exposed to these toxic fats, they lose their normal “filter-like” function and shift into a state that attracts immune cells and promotes scar formation. In short, LSEC damage is not just a consequence of MASH, it helps drive the inflammation and fibrosis that make the disease worse.
A key regulator identified in this work is GSK3, an enzyme that becomes overactive when LSECs are under fat-induced stress and then pushes them toward this disease-driving state. The thesis also focuses on two “adhesion” proteins on the LSEC surface: VCAM1 and ICAM1, which act like molecular Velcro and help cells stick to each other. VCAM1 is a sign of this abnormal LSEC state and can contribute to scar-promoting changes, while ICAM1 is switched on through gene-control mechanisms (epigenetic regulation) linked to GSK3 and related factors. In experimental models of MASH, blocking GSK3, VCAM1, or ICAM1 reduced inflammation and scarring, suggesting potential treatment approaches that specifically protect or reprogram LSECs.