CTSD and type 2 diabetes mellitus: Notably, TFEB overexpression significantly reversed the impaired ALP function in both T2DM mice (Fig. 4A) and HG-cultured HT22 cells (Fig. 5A), as indicated by elevated expression of LC3-II, LC3-II/I ratio, CTSB, CTSD and LAMP1, and a decrease in p62 levels.