Heparanase upregulation in astrocytes and macrophages recruited to the injured spinal cord

Abstract

Mammalian heparanase (Hpa1) is a heparan sulfate-cleaving endo-glucuronidase exploited by inflammatory and cancer cells to invade connective tissues. We hypothesize Hpa1 involvement also in the recruitment of reactive astrocytes and macrophages to the injured spinal cord. To test this, spinal cords of adult rats were hemisected at T8. Q-PCR for Hpa1 mRNA in the cord at T7-9 indicated initial (3 dpi) decrease followed by progressive increase to levels in excess of that in the normal cord by 14 dpi. Combined in situ hybridization for Hpa1 mRNA and immunocytochemistry for cell markers indicated increased Hpa1 expression in GFAP+ astrocytes and ED-1+ macrophages in the lesion by 7–14 dpi. Upregulated Hpa1 expression was also observed in astrocytes that invaded the scratched area in an in vitro model. Taken together, our results indicated upregulated expression of Hpa1 in astrocytes and macrophages that were recruited to the injury. Research funds: CRCG10204997 & 10205634 to DKYS