FASEB journal : official publication of the Federation of American Societies for Experimental Biology
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The goal of this study was to further explore potential mechanisms through which diabetogenic dietary conditions that result in promotion of insulin resistance (IR), a feature of non-insulin dependant diabetes mellitus (type-2 diabetes), may influence Alzheimer's disease (AD). Using genome-wide array technology, we found that connective tissue growth factor (CTGF), a gene product described previously for its involvement in diabetic fibrosis, is elevated in brain tissue in an established mouse model of diet-induced IR. ⋯ Finally, using in vitro cellular models of amyloid precursor protein (APP)-processing and Abeta generation/clearance, we confirmed that human recombinant (hr)CTGF may increase Abeta1-40 and Abeta1-42 peptide steady-state levels, possibly through a mechanism that involves gamma-secretase activation and decreased insulin-degrading enzyme (IDE) steady-state levels in a MAP kinase (MAPK)/ phosphatidylinositol 3-kinase (PI-3K)/protein kinase-B (AKT)1-dependent manner. The findings in this study tentatively suggest that increased CTGF expression in the brain might be a novel biological predicative factor of AD clinical progression and neuropathology in response to dietary regimens promoting IR conditions.