Abstract P755: Perlecan Lg3 is Neuroprotective and Functionally Restorative in Experimental Ischemic Stroke

Abstract

Despite promising advancements, ischemic stroke remains a leading cause of death and disability. We previously determined that human recombinant ~85-kDa C-terminal protein fragment of the vascular basement membrane proteoglycan perlecan termed domain V (DV) is neuroprotective, pro-angiogenic, neurogenic and functionally restorative when administered after experimental stroke (transient and permanent middle cerebral artery occlusion -MCAO) in mice and rats. As previous studies suggest, the 23-kDa subdomain of DV called laminin globular domain 3 (LG3) may confer most of DV’s biological activity and is more amenable to production, we tested whether human recombinant perlecan DV LG3 (also termed “DV LG3 ”) might be neuroprotective and functionally restorative in the transient MCAO (intraluminal filament model). Methods: Fifty male mice (C57BL/6J, 10-12 weeks old, 24–30 g) underwent MCAO for 60 min and were survived for seven days. At reperfusion mice were randomly allocated to one of three treatment groups and immediately received either human recombinant DV treatment (positive control, n=16 2 mg/kg, i.p.), LG3 (n=19 6 mg/kg, i.p.), or equivalent volume of PBS vehicle (n=15) ; and again on post-MCAO days 2 and 4. The DV:LG3 dose ratio was selected based on a preliminary in vivo dose evaluation study of therapeutic equivalence. Functional outcome measures (grip strength and grid-hang tests) were determined at baseline and on post-MCAO days 1, 3 and 7. Body weight was measured daily as per welfare. To determine infarct size on post-MCAO day 7, whole brain samples were harvested, sectioned and stained with 2,3,5- Triphenyltetrazolium chloride. The induction of MCAO, DV, DV LG3 or PBS treatments, functional tests and analyses were performed, blindly, by different individuals. While DV treatment significantly reduced mean infarct volume as expected (p<0.022, compared to PBS control group), DV LG3 further reduced infarct volumes (p<0.0001), weight loss (p<0.0002) and improved functional outcome measures (p<0.01) compared to PBS group. Our findings show that human recombinant DV LG3 is neuroprotective and functionally restorative, may be even more effective than DV, and is worthy of more study as a readily producible therapy for ischemic stroke.