👤 Cornelia Amalinei

Depression and obesity are amongst the most serious global health challenges. Each of them is associated with high morbidity, chronicity, and socioeconomic burden. Increasing evidence suggests that these conditions are not merely comorbid but share convergent biological pathways (e.g., hypothalamic-pituitary-adrenal axis dysregulation, chronic inflammation, gut dysbiosis, and mitochondrial dysfunction). All these components contribute together to the development and persistence of depressive symptoms as well as to an increase in adiposity. Within this framework, adipose tissue has emerged as an essential endocrine organ that has a deep impact on neuroimmune signalling and mood regulation through its secreted molecules, such as leptin, adiponectin, resistin, omentin, apelin, chemerin, and visfatin. The current management of depression involves a comprehensive, multidisciplinary approach that includes pharmacological treatment and psychotherapeutic support, alongside lifestyle changes. Here we highlight the molecular crosstalk between adipose tissue and the brain, summarising the evidence of adipokines' dysregulation role in connecting metabolic dysfunction to depressive neurobiology. By integrating metabolic, immunological, and neuroendocrine perspectives, this narrative review underscores the need to reconceptualise depression as an immunometabolic disorder. Understanding adipokine-mediated pathways may reveal new biomarkers and therapeutic targets, fostering interdisciplinary approaches. This would allow for the development of new treatment strategies, which include recombinant adipokines, anti-inflammatory agents, and microbial modulation. These new strategies might provide a significant benefit in selected patients, in addition to conventional antidepressants. Show less

Firstly identified by anatomists, the fat tissue is nowadays an area of intense research due to increased global prevalence of obesity and its associated diseases. Histologically, there are four types of fat tissue cells which are currently recognized (white, brown, beige, and perivascular adipocytes). Therefore, in this study we are reviewing the most recent data regarding the origin, structure, and molecular mechanisms involved in the development of adipocytes. White adipocytes can store triglycerides as a consequence of lipogenesis, under the regulation of growth hormone or leptin and adiponectin, and release fatty acids resulted from lipolysis, under the regulation of the sympathetic nervous system, glucocorticoids, TNF-α, insulin, and natriuretic peptides. Brown adipocytes possess a mitochondrial transmembrane protein thermogenin or UCP1 which allows heat generation. Recently, thermogenic, UCP positive adipocytes have been identified in the subcutaneous white adipose tissue and have been named beige adipocytes. The nature of these cells is still controversial, as current theories are suggesting their origin either by transdifferentiation of white adipocytes, or by differentiation from an own precursor cell. Perivascular adipocytes surround most of the arteries, exhibiting a supportive role and being involved in the maintenance of intravascular temperature. Thoracic perivascular adipocytes resemble brown adipocytes, while abdominal ones are more similar to white adipocytes and, consequently, are involved in obesity-induced inflammatory reactions. The factors involved in the regulation of adipose stem cells differentiation may represent potential pathways to inhibit or to divert adipogenesis. Several molecules, such as pro-adipogenic factors (FGF21, BMP7, BMP8b, and Cox-2), cell surface proteins or receptors (Asc-1, PAT2, P2RX5), and hypothalamic receptors (MC4R) have been identified as the most promising targets for the development of future therapies. Further investigations are necessary to complete the knowledge about adipose tissue and the development of a new generation of therapeutic tools based on molecular targets. Show less