JAK/STAT signaling: novel prospectives in the obesity diagnostics

The problem of obesity seemed to be nonresolved over the past decades. Obesity has been proven to be an important pathogenetic factor of metabolic disorders in humans, leading to the development of various disorders. Many questions remain open, despite numerous studies, clarifying the aspects of obesity pathogenesis and associated changes in metabolism. The aim of this study was to consider the components of JAK / STAT signaling system: proteins STAT1, STAT3, SOCS1, SOCS3, as well as the level of cytokine IL-6 in blood serum of obese individuals. 210 patients were examined, being divided into groups: I – individuals with normal body weight; II – patients with overweight; III – patients with metabolically healthy obesity, IV – patients with metabolically unhealthy obesity. A set of immunological and general clinical research methods was used in the work. The study revealed significantly altered values of JAK/STAT signaling system components and IL-6 cytokine levels in blood serum of obese patients. Increased serum IL-6 levels were found in obese subjects as well as statistically significant correlation between IL-6 and lipid profile parameters, STAT1, STAT3, and SOCS1, SOCS3 proteins. The STAT1 and STAT3 levels were decreased in obese individuals in contrast to the persons with normal and overweight body weight. An imbalance of SOCS1 and SOCS3 proteins was also observed in individuals with different obesity phenotypes. Significant correlations were revealed between serum IL-6, STAT1, STAT3, SOCS1, and SOCS3 levels, as well as lipid metabolism parameters in patients with metabolic healthy and metabolic unhealthy obesity. The results of these studies are consistent with available literature data on changed expression of STAT1, STAT3 and SOCS1, SOCS3 proteins in obese patients, as well as importance of SOCS1, SOCS3 proteins in STAT expression levels by the negative feedback relations. One may also suggest participation of IL-6 cytokine in activation of JAK/STAT signaling system and maintenance of meta-inflammation in obese individuals. Thus, the study of JAK/STAT signaling indices may be a promising area in diagnostics and search for new strategies in obesity management.