NORE1A loss promotes MASLD/MASH

NORE1A (RASSF5) is a tumor suppressor that is frequently down-regulated in liver tumors. It is an upstream component of the HIPPO pathway, a key regulator of liver development and metabolism. HIPPO disruption can lead to the development of MASLD/MASH. While studying the phenotype of NORE1A knockout mice, we noticed that they exhibit no overt liver tumor phenotype, but have a strong propensity to develop fatty livers characteristic of MASLD/MASH. Additionally, knockdown of NORE1A in liver cells upregulates sterol regulator element binding protein 1 (SREBP1), whose deregulation is central to the development MASLD. Examination of primary human MASLD samples showed an inverse correlation between the expression of NORE1A protein and TAZ, a downstream effector of the HIPPO pathway. Thus, loss of NORE1A expression may contribute to the development of MASLD/MASH in humans and NORE1A knockout mice may provide a new MASLD/MASH model that more accurately mimics the human disease.