Knockdown of CLC-3 may improve cognitive impairment caused by diabetic encephalopathy

Background: Diabetic encephalopathy(DE) is a neurological complication of diabetes, and its pathogenesis is unclear. Current studies indicate that Insulin receptors and downstream signaling pathways play a key role in the occurrence and development of DE. Additionally, CLC-3, a member of the CLC family of anion channels and transporters, is closely related to the secretion and processing of Insulin. Here, we investigated the changes and putative roles of CLC-3 in diabetic encephalopathy.

Results: To this aim, we combined lentivirus and adeno-associated virus gene transfer to change the expression level of CLC-3 in the HT-22 hippocampal cell line and hippocampal CA1. We studied the role of CLC-3 in DE through the Morris water maze test.CLC-3 expression increased significantly in HT-22 cells cultured with high glucose and STZ-induced DE model hippocampus. Moreover, Insulin Receptor(IR) and downstream PI3K/Akt/GSK3β signaling pathways were also dysfunctional. After knocking down CLC-3, impaired cell proliferation, Apoptosis, IR and the downstream PI3K/Akt/GSK3β signaling pathways were significantly improved. However, when CLC-3 was overexpressed, the neurotoxicity induced by high glucose was further aggravated. Rescue experiments found that through the use of inhibitors such as GSK3β, the PI3K/Akt/GSK3β signaling pathways pathway changes with the use of inhibition, and the expression of related downstream signaling molecules such as Tau and p-Tau also changes accordingly. Using adeno-associated virus gene transfer to knock down CLC-3 in the hippocampal CA1 of the DE model, the IR caused by DE and the dysfunction of the downstream PI3K/Akt/GSK3β signaling pathway were significantly improved. In addition, the impaired spatial recognition of DE was partially restored.

Conclusion: Our study proposes that CLC-3, as a key molecule, may regulate Insulin Receptor signaling and downstream PI3K/Akt/GSK3β signaling pathways and affect the pathogenesis of diabetic encephalopathy.

CLC-3; Diabetic encephalopathy; Morris Water Maze test; Novel object recognition test.