Adeno-Associated Viral Gene Therapy in a Novel Mouse Model Age-Related Macular Degeneration

SUMMARY OF PROPOSED REsAH 8 State the objectives, hypotheses, and specific aims of the proposed research. State the relevance of the proposed research to macular degeneration. Describe, briefly and concisely, the experimental design and methods for achieving these goals. This abstract is meant to serve as a succinct and accurate description of the proposed work when separated trom the application. Do not exceed the space provided. Introduction: Age-related macular degeneration (AMD) is the leading cause of elderly blindness in the U.S. Absence of good animal models has limited mechanistic understanding and thwarted development of therapies. We observed that mice genetically deficient either in the macrophage chemokine Ccl-2 develop the pathological hallmarks of AMD in an agedependent fashion. Preliminary Data: (1) Cel2-/-mice develop lipofuscin, drusen, geographic atrophy, and choroidal neovascularization (CNV) as they age. (2) Various complement components, complement regulatory proteins, and IgG are deposited in the retinal pigmented epithelium (RPE) and choroid of Cel2-/-mice as they age, as in patients with AMD. (3) These findings are not present in age-matched wild-type mice. (4) Macrophages infiltrate into the choroid of aged wild-type mice but not Cc/2-/-mice in large numbers. (5) C5a and IgG upregulate RPE and choroidal endothelial cell secretion ofCcl-2. (6) C5a and IgG upregulate RPE secretion of vascular endothelial growth factor (VEGF), consistent with CNV development. (7) Wild-type macrophages are immobilized by, adhere to, and degrade C5a and IgG on eye sections of CelZ/- mice in situ. Hypothesis: The accumulation of drusen and lipofuscin associated with senescence in CelT/- mice is due to impaired clearance by scavenger macrophages, whose recruitment is impaired in the absence ofCcl-2, and ultimately leads to geographic atrophy and CNV; rescue ofCcl-2 function can prevent or regress AMD-like pathology in Cel2-/-mice. Specific Aim: To demonstrate that rescue ofCcl-2 function by adeno-associated viral gene therapy inhibits or-regresses AMD-like pathology in elderly CelZ/- mice. Significance: These studies will provide mechanistic insights into and more effective treatments for AMD. KEY PERSONNEL Name, Degree(s) Jayakrishna Ambati, MD Position Title Role in Project Department and Organization OphthalmologylUniv. of Kentucky OphthalmologylUniv. of Kentucky Akshay Anand, PhD Assistant Professor Principal Investigator Postdoctoral Scholar FelJow 3