Targeting Aromatase and 5-α-Reductase to Limit Dysfunctional Adipogenesis in Multiple Symmetric Lipomatosis

Background: Multiple symmetric lipomatosis (MSL) is an orphan disease characterized by pathological expansion of lipomatous tissue (LT) in the subcutaneous adipose tissue (SAT) areas, causing severe deformities and compression of vital organs. To date, the only treatment options available are either lifestyle modification or surgical excision/liposuction. Since sex hormones play an important role in adipose tissue (AT) expansion, they may represent an opportunity for pharmacological treatment. Methods: LT and control SAT were collected from eight MSL patients. Both tissues and derived stromal vascular fraction (SVF) were compared in terms of aromatase (hCYP19A1) and 5-α-reductase isoform (hSRD5A1, -2 and -3) mRNA expression. Primary cultures obtained from one MSL patient were exposed to an aromatase inhibitor, 5-α-reductase inhibitor and DL-α-Lipoic Acid and assayed for cell viability, proliferation and adipogenic differentiation. Results: hCYP19A1, hSRD5A1 and hSRD5A3 were expressed in both MSL-affected and MSL-spared tissues at different levels. Cell viability and proliferation of LT-derived SVF cells were slightly increased by treatment with DL-α-Lipoic Acid and the aromatase inhibitor. Adipogenesis was slightly reduced by Finasteride and strongly reduced by Exemestane (more in LT- than in SAT- derived primary cultures). Conclusions: These preliminary results pave the way for the use of aromatase and 5-α-reductase inhibition as a potential pharmacological approach to tackling dysfunctional adipogenesis in MSL. Therefore, the reported study should be interpreted as exploratory and further experiments are recommended in a larger number of patients to validate these promising results.