1761-P: Verapamil Increases ß-Cells Proliferation in MIN6 Cells and ß-Cell Mass in Zebrafish Model

Abstract

Recent clinical studies highlighted a significant clinical utility for verapamil in both type 1 (T1D) and type 2 (T2D) diabetes. Verapamil treatment in T1D lowered dependency on exogenous insulin. In T2D, addition of verapamil to metformin therapy improved glycemic control. These findings led us to further study the molecular and cellular mechanisms of verapamil in the treatment of T1D and T2D using an in vitro (MIN6 mouse β cell-line) and in vivo zebrafish (Danio rerio) model. In this study, MIN6 cells were cultured in growth media containing 5.6 mM glucose (mimicking normoglycemia) and supplemented with 2% BSA to eliminate any proliferative effect of high glucose in the media, and growth factors in FBS. The cells were treated with different concentrations of verapamil. The levels of cell proliferation (MTT assay), cell growth (cell counts), Ki67 expression (IF), and cell cycle (flow cytometry) were studied in MIN6 cells treated with the optimal dose detected (50 μM) of verapamil. Larvae (24hpf) of the Ins:NfsB-mCherry transgenic zebrafish (expressing mCherry fluorescence reporter under the control of insulin proximal promoter) were treated with 10 uM of verapamil for 3 days. Full larvae images were acquired using a stereo microscope. Our results show that verapamil induced significantly increased proliferation of MIN6 cells. Cell cycle analysis shows initiation of the proliferative effect during an early time point (1-4 hours) after verapamil treatment. Higher Ki67 expression indicated enhanced cellular proliferation at 24 hours and growth curve data confirmed that the proliferative effect of verapamil lasted for 7 days. As evident from increased mCherry fluorescence intensity in zebrafish larvae, verapamil treatment increased the β cell mass during the exposure period of three days. Taken together, our findings support the positive impact of verapamil on mouse β cell proliferation in vitro as well as on increased β cell mass in Zebrafish model. Disclosure H.Arefanian: None. S.E.John: None. S.Jacob: None. M.Alhusayan: None. S.J.Kurian: None. S.P.Kochumon: None. S.T.K.Sindhu: None. F.Alzaid: None. M.Abu-farha: None. J.Abubaker: None. A.T.Thangavel: None. A.Al madhoun: None. R.Ahmad: None. F.Almulla: None. F.Alrashed: None. F.Bahman: None. H.Alsaeed: None. N.A.Abukhalaf: None. S.Shenouda: None. M.R.Williams: None. R.Nizam: None. Funding Kuwait Foundation for the Advancement of Sciences (RACB-2019-001)