Metabolically and epigenetically reprogrammed splenic TRNP1hiCD8+ T cells exacerbate liver fibrosis

The cross-talk between spleen and liver in MASLD/MASH progression remains poorly understood. Here, we find the enlarged spleens in MASLD patients, and the induced TRNP1hiCD8+ T cells in the spleens of MASLD/MASH mouse models and confirmed in MASLD patients, with pro-fibrotic property by secreting INSR-α.

Mechanistically, demethylated DNA and H3K27me3, increased H3K27ac, together with bolstered enhancer-promoter contact, synergistically reorganized chromatin topologically associating domains spatially to initiate the expression of transcription factor TRNP1 in splenic CD8+ T cells. TRNP1 then transcriptionally activates the expression of FURIN and CTSD, promoting the maturation and ectodomain shedding of INSR-α thereby facilitating its secretion to activate hepatic stellate cells.