Abstract TP226: Impact Of Apolipoprotein A-i In The Attenuation Of Stroke And Stroke Symptoms

Apolipoprotein AI is the major protein component of high-density lipoprotein (HDL) particles in plasma. Inflammatory cytokines such as TNF and IL-1β repress the production of ApoA-I from hepatocytes and increase the expression of serum amyloid A (SAA), which becomes the major protein component of HDL in this context. Consequently, lipid-poor ApoA-I is rapidly catabolized in the liver and the kidney. These findings could be meaningful if ApoA-I, in addition to its proimmune features, had anti-inflammatory potential. In this way, removal of ApoA-I could intensify the inflammatory response, resulting in a more robust effect. Recent studies have suggested that serum apolipoprotein A1 maybe a predictor and prognostic biomarker in acute ischemic stroke in humans. To understand the impact of ApoA-I in stroke, we have begun to analyze the role of ApoA-I in mouse models of stroke. Mice with reduced or deficient in ApoA-I and subjected to ischemia and reperfusion injury or permanent ischemia, had increased inflammatory responses, larger infarct volumes, and poorer outcomes than wildtype mice. Mice transgenic for the human ApoA-I gene showed a level of protection not seen in the wildtype mice when given an ischemic injury. Administration of AAV human ApoA-I increased HDL levels in deficient mice and provided protection against ischemic injury. Additionally, drugs to enhance ApoA-I expression showed protection against strokes in the mouse models. These studies, along with subsequent investigations will provide a better understanding and potential therapeutic approaches in the field of stroke.