Reduced ZMPSTE24 expression leads to prelamin accumulation and development of steatosis in MASLD patients.

Abstract

Mutations of nuclear lamina-associated proteins LMNA and ZMPSTE24 have been associated with fatty liver. We report that the changes at the nuclear envelope we described in MASLD patients are caused by downregulation of ZMPSTE24, an enzyme that processes prelamin to mature lamin A. In addition, Zmpste24 mutant mice develop hepatic steatosis and exhibit upregulation of p53 target genes. p53 activity is also induced in genes differentially expressed in MASLD patients. Furthermore, p53 regulates genes bound by FOXA2 in these individuals, corresponding to observations in Zmpste24 mutants. In contrast, expression of glucose and insulin regulated genes is reduced in MASLD patients, suggesting altered glucose metabolism and insulin resistance, hallmarks of type 2 diabetes (T2D). Hence, our genomics data show that MASLD patients with severe steatosis but yet without MASH are already suffering from severe metabolic consequences and underscore the need for treatment at this stage of the disease.