Figure 4.

MCT1 is a key regulator of lactate bidirectional fluxes in beige adipocytes. MCT1, which is expressed at the cell surface of beige adipocytes, sustains bidirectional lactate fluxes. Lactate export, which is predominant under noradrenergic stimulation such as cold exposure, supports glycolysis through NAD⁺ regeneration (red arrows). Concomitant lactate import occurs (green arrows), which fuels the oxidative metabolism and promotes the induction of UCPl, thereby increasing the oxidative capacity of beige adipocytes (adapted from Lagarde et al., 2020). ETC, electron transport chain; ATPase, ATP synthase; and FA, fatty acids.