Diabetic Ketoacidosis Induces Tau Hyperphosphorylation in Rat Brain

Area of Science:

• Neuroscience
• Endocrinology
• Pathology

Background:

• Diabetes mellitus (DM) is a known risk factor for cognitive impairment and Alzheimer's disease (AD).
• Diabetic ketoacidosis (DKA), a severe DM complication, may exacerbate brain damage and AD progression.
• The molecular mechanisms linking DKA to neurodegeneration in AD remain largely unknown.

Purpose of the Study:

• To elucidate the molecular mechanisms by which DKA contributes to neurodegeneration relevant to Alzheimer's disease (AD).

Main Methods:

• DKA was induced in a rat model using streptozotocin injection followed by a 48-hour starvation period.
• Brain alterations associated with AD, particularly tau phosphorylation, were investigated.
• Analysis included tau kinases, phosphatases, and signaling pathways like mTOR-AKT.

Main Results:

• DKA induced significant tau protein hyperphosphorylation at AD-associated sites.
• Activation of c-Jun N-terminal kinase and downregulation of protein phosphatase 2A were identified as key mediators.
• Disruption of the mTOR-AKT signaling pathway and altered synaptic protein levels were observed.

Conclusions:

• DKA promotes neurodegenerative changes implicated in Alzheimer's disease (AD) pathogenesis.
• The findings highlight the roles of specific kinase/phosphatase pathways and mTOR-AKT signaling in DKA-induced brain alterations.
• This research provides insights into how DKA may elevate the risk for developing AD.