(1395) Targeted Delivery of Human Neural Stem Cells to Treat Neurologic Deficits After Cardiac Arrest

Introduction: Cardiac arrest (CA) affects over 640,000 Americans annually in and outside the hospital. However, neurological deficits post-CA remains a major cause of mortality and long-term disability. Transplantation of human neural stem cells (hNSCs) is a promising strategy in CA rat models. However, there is currently limited understanding regarding the engrafted hNSCs including the localization within the rat brain. We have modified hNSCs with metabolically glycoengineered sugar analog TProp (TProp-hNSCs) and demonstrated improved adhesion and differentiation. This study aims to evaluate the effects of TProp-hNSCs and their post-injection localization in the rat hippocampus, a brain area corresponding to known cognitive and physical impairment in CA.

Methods: In vitro, hNSCs were labeled with Molday Ion Rhodamine B (MIRB), an iron-oxide MRI contrast reagent that can be used in cell labeling and tracking, at 25ug/mL and 50ug/mL. T2-weighted magnetic resonance imaging (MRI), Prussian Staining, and Rhodamine fluorescence were then performed to visually confirm and analyze the strength of MIRB signals. In-vivo, 2x10^5 MIRB-labeled hNSCs or MIRB-labeled TProp-hNSCs were injected intracerebroventricularly (ICV) in rats after an 8 min asphyxia-induced CA. Successive T2-weighted MRI images were collected at 7-, 14-, and 30- days post-administration. Hypo-intense signals localized in the hippocampal region were visually identified, measured, and analyzed using ImageJ.

Results: In-vitro, hNSCs labeled with 50ug/mL MIRB displayed a higher quantified fluorescence intensity and Prussian blue-positive area when compared to 25μg/mL cells. The presence of MIRB-labeled cells was also visually confirmed via T2-weighted MRI, showing strong hypo-intense signals from a pellet of 50ug/mL MIRB-labelled cells. In-vivo, TProp-hNSCs were shown to have significantly stronger neuroprotective functions compared to hNSCs. MIRB of TProp-hNSC shows a stronger and more persistent hippocampal localization in the rat CA brain compared to hNSCs.

Conclusions: TProp-hNSCs improved functional outcomes after CA. MIRB labeling of hNSCs demonstrates high potential for tracking hNSCs post-resuscitation.
Partially supported by R01NS125232 and R01NS110387 from NIH (both to XJ).