Psychosocial-Stress, Liver Regeneration and Weight Gain: a Conspicuous Pathophysiological Triad

Psychosocial stress alters several physiological parameters resulting in multiple disorders, particularly compromising the immune system thereby provoking various diseases including liver disorders. However, the plausible underlying mechanisms remain elusive. Recent literature provides mechanistic evidences of detrimental effects of psychosocial stress on physiology of different body organs including liver. The data of stress-induced pathophysiological changes in liver functions and obesity were systematically collected from PubMed, ScienceDirect and the Web of Science Databases published in English. Stress and glucocorticoids (GCs) control food intake and energy expenditure through appetite stimulators neuropeptide Y (NYP) and agouti-related protein (AgRP) in hypothalamus. Principle effectors of the activated hypothalamic-pituitary-adrenal (HPA) axis in response to psychosocial stress are proopiomelanocortin (POMC)-derived adrenocorticotropic hormone (ACTH) and GCs. Stress-induced GCs hyper-secretion triggers glucocorticoid receptor (GR)-dependent transcriptional factor, nuclear factor kappa B (NFκB), which interferes TNFα-IL6 and keap1-Nrf2 pathways in liver regeneration and obesity through fine-tuning of TNFα, IL6 and Nrf2 signaling. In this review, it is contrived upon existing evidence to put forward a model whereby exposure to life-stress has a prominent impact over weight gain and can alter the regenerative mode of a damaged liver through Keap1-Nrf2 and TNFa-IL6 pathways.