Primaquine activates Keratin 7 to treat diabetes and its complications.

Background: The global prevalence of type 2 diabetes mellitus (T2DM) raises the rates of its complications, such as diabetic nephropathy and cardiovascular diseases. To conquer the complications, new strategies to reverse the deterioration of T2DM are urgently needed. In this project, we aimed to examine the hypoglycemic effect of primaquine and explore its specific target.

Methods: In vitro T2DM insulin resistance model was built in HepG2 cells to screen the potential anti-diabetic chemicals. On the other hand, the potential protein targets were explored by molecular docking. Accordingly, we chose C57BL/6 N mice to establish T2DM model to verify the effect of the chemicals on anti-hyperglycemia and diabetic complications.

Results: By targeting the Keratin 7 (K7) to activate EGFR/Akt glucose metabolism signaling pathway, primaquine poses a potent hypoglycemic effect. The level of acetyl-CoA is enhanced markedly, supporting that primaquine upregulates the aerobic glycolysis. Moreover, primaquine ameliorates kidney function by reducing the secretion of urinary proteins and creatinine, especially for the urea nitrogen which is significantly decreased compared to no-treatment T2DM mice. Notably, primaquine restores the level of plasma low-density lipoprotein cholesterol (LDL-C) nearly to normal, minimizing the incidence of cardiovascular diseases.

Conclusions: We find that primaquine may reverse the dysregulated metabolism to prevent diabetic complications by stimulating EGFR/Akt signaling axis, shedding new light on the therapy of T2DM.

Graphical Abstract: Insulin resistance is characterized by reduced p-Akt and glucose metabolism, dominated by anaerobic glycolysis. Primaquine activates the complex made of K7 and EGFR, further stimulating Akt phosphorylation. Then, p-Akt promotes the aerobic glucose metabolism and upregulates Ac-CoA to mobilize TCA cycle, improving insulin sensitivity.

Supplementary Information: The online version contains supplementary material available at 10.1007/s40200-022-01135-8.