(465) Effect of SGLT2 inhibitors on fibroblast activation

Objective : To establish an in-vitro model and evaluate the cardioprotective potential for sodium-linked-glucose transporter 2 inhibitors (SGLT2i) in fibroblasts. We hypothesize that fibroblasts exposed to glucose experience oxidative stress and are sensitized to pathological stimuli such as TGFβ due to depletion of a protective antioxidant pathway.

Methods: Mouse embryonic fibroblasts (3T3s) were treated with a combination of glucose, transforming growth factor beta (TGFβ), and either empagliflozin or ertugliflozin. Transcriptional activity was assessed by quantitative PCR (qPCR) against genes known to change in response to oxidative and pathological stimuli such as smooth muscle actin (Acta2), peroxisome proliferator-activated receptor gamma coactivator 1-alpha (Pgc1a), and lactose dehydrogenase-A (Ldha). Protein expression was assessed by Western blot to specifically evaluate changes in the nuclear localization of the antioxidative response transcription factor nuclear factor erythroid 2 (NFE2)-related factor 2 (NRF2).

Results: 3T3s treated with either 1ng/ul TGFβ or 35mM glucose reliably induced Acta2 expression two- to five-fold over baseline and decreased Pgc1a expression to less than 10% of baseline as expected, while treatment with up to 10uM empagliflozin or ertugliflozin alone had no significant impact on Acta2 or Pgc1a expression. Simultaneous treatment of 3T3s with TGFβ, glucose, and either empagliflozin or ertuglifozin however did not blunt Acta2 induction as expected or significantly maintain antioxidant response pathways as assessed by increased expression of Pgc1a and Ldha. Protein analysis of nuclear NRF2 was inconclusive as endogenous NRF2 was difficult to detect in 3T3s.

Conclusions: Timing of in-vitro SGLT2i administration likely impacts the transcriptional response of fibroblasts. Future experiments will be performed to pre-treat 3T3s with SGLT2i prior to glucose and TGFβ treatment.