Role of murine macrophage in temporal regulation of cortisol- and serotonin-induced adipogenesis in pre-adipocytes when grown together.

Regulation of adipogenesis, the root cause for obesity, is very poorly understood. However, studies have presented evidence of immuno-metabolic regulation of adipose tissue during periods of chronic psychological stress, leading to adverse conditions related to stress manifestation, including visceral obesity and atherosclerosis. Despite pronounced association of hormonal markers of stress with dys-regulated metabolic states, the contributing signalling events are yet to be established. It is apparent that to understand contributing signalling events we need a model. Although an in vivo model is preferred, it is difficult to establish. The current report, therefore, presents an in vitro model system for the simulation of adipose tissue in a chronic stress micro-environment by growing pre-adipocytes with macrophages in the presence and absence of stress hormones. In this report, effects of cortisol and serotonin on the kinetics of immune and metabolic changes in adipocytes and macrophage (alone and co-cultured) was studied through whole genome transcriptome profiling. A transition from pro- to anti-inflammatory response in the immune profile of pre-adipocytes, with increasing time in co-culture with macrophages, was observed. This transition was reversed by stress hormones cortisol and/or serotonin.