Epigenetic regulation of fatty acid chain elongation in MAFLD and its implications in the liver-brain axis dysfunction.

Lipid metabolism plays a crucial role in cellular health and physiology by acting as an energy storehouse, cell membrane component, brain development and signaling molecules. Crucial steps to metabolize dietary fat take place within the hepatic tissue. Any abnormalities in the hepatic fatty metabolic pathways cause abnormal accumulation of lipid inside the liver, causing MAFLD, ranging from simple steatosis to more complex steatohepatitis and fibrosis. During high-fat-diet-induced hepatic inflammation, systemic proinflammatory cytokines disrupt the blood-brain barrier, resulting in neuroinflammation, cognitive impairment, brain damage and even neurodegeneration. Further, during this altered metabolic scenario, circulating metabolites pass through the impaired BBR and deregulate the epigenetic landscape of the central nervous system. Thus, it becomes crucial to understand the epi-metabolic crosstalk between two crucial organs of our body: the liver and the brain. Here in this chapter, we demonstrate the approach that we are using in our laboratory to study the epigenetic reprogramming in the context of metabolic gene expression in the liver, which is the causal for life style disorders like MAFLD. Remarkably, we intend to understand how liver dysfunction can have an implication in the brain function. Here, we discuss the concept of developing a diet-induced steatosis and steatohepatitis mouse model to understand the disease progression and its interconnection with brain physiology. Further, we also demonstrate 2D and 3D cell culture models to study the liver-brain cross-talk in greater molecular detail. Collectively, these approaches can provide a template for studying the role of epi-metabolic cross-talk in liver-guided brain dysfunction upon MAFLD.