Strategies for improving IPAD

R. Carare 2018,

Agents that improve contractility of vascular smooth muscle cells

Phosphodiesterase III is the major cAMP-hydrolyzing PDE uniquely expressed in vascular smooth muscle cells; PDE IIIA isoforms are also involved in cardiovascular function by regulating vascular smooth muscle growth and phenotypic changes. Cilostazol is a selective inhibitor of PDE III that increases cAMP in vascular cells and has multiple effects on the vasculature such as vasodilatation, anti-oxidation, anti-inflammation, regulation of smooth muscle cells, increase in cerebral haemodynamics and arterial elasticity with maintenance of microvascular integrity, as reviewed in (19). Cognition is significantly improved in experimental models and in humans receiving Cilostazol (20)(21)(22)(23). Administration of Cilostazol significantly improves IPAD and the brains of mice treated with Cilostazol show effects upon extracellular matrix, with upregulation of the anti-fibrillogenic glycoproteins (24)(25).

Using chaperones for efficient transport along the IPAD pathways

Clusterin (Apolipoprotein J) is a multifunctional protein that reduces the aggregation and toxicity of Aβ and appears to be beneficial in atherosclerosis (26)(27)We recently demonstrated that in APP/PS1 mouse models of Alzheimer’s disease, crossed with clusterin knockout mice, result in disappearance of Aβ plaques but an increase in severity of CAA. These findings suggest that clusterin is required for efficient chaperoning of solubilized proteins from plaques along IPAD (28). Administration of clusterin as a preventative therapy when the integrity and function of smooth muscle cells and basement membranes are not compromised may yield positive results for the prevention or delay in onset of symptoms of CAA and Alzheimer’s disease. Taxifolin is flavonoid that appears to maintain amyloid in its soluble forms more amenable for clearance (29) We are investigating whether Taxifolin facilitates IPAD.

Agents acting upon the innervation of smooth muscle cells

Experimental work is ongoing in this area. Results suggest that agents such as Prazosin, an alpha(1)-adrenoceptor antagonist, acting upon cholinergic or adrenergic innervation of cerebral arteries result in improvements of IPAD and in reduction of CAA in transgenic mouse models of Alzheimer’s disease (30).




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