snRNA-Seq analysis of islets from WT mice treated with or without 0.5mM Glucosamine

Prolonged exposure to high glucose stimulates mTORC1, resulting in impaired glucose metabolism and exacerbation of ER stress and inflammation. However, the precise mechanism by which glucose regulates mTORC1 activity in diabetes remains unclear.

We performed metabolic labeling with 13C6- glucose in diabetic animals treated with or without the SGLT2 inhibitor (SGLT2i) dapagliflozin or insulin, followed by targeted metabolomics and metabolic flux analysis. We found that tissue glucose concentrations strongly correlate with glucosamine, rather than with other glucose or amino acid metabolites. Plasma glucosamine levels are increased in patients with impaired fasting glucose (IFG) and type 2 diabetes (T2D) and are inversely correlated with b-cell function.