Alteration of thrombospondin-1 and -2 in rat brains following experimental intracerebral hemorrhage. Laboratory investigation.

Abstract

Spontaneous intracerebral hemorrhage (ICH) is among the most intractable forms of stroke. Angiogenesis, an orchestrated balance between proangiogenic and antiangiogenic factors, is a fundamental process to brain development and repair by new blood vessel formation from preexisting ones and can be induced by ICH. Thrombospondin (TSP)–1 and TSP-2 are naturally occurring antiangiogenic factors. The aim of this study was to observe their expression in rat brains with ICH. Intracerebral hemorrhage was induced in adult male Sprague-Dawley rats by stereotactic injection of collagenase VII or autologous blood into the right globus pallidus. The expression of TSP-1 and -2 was evaluated by immunohistochemistry and quantitative real-time reverse transcription–polymerase chain reaction analysis. After the induction of ICH, some TSP1- or TSP2-immunoreactive microvessels resided around the hematoma for ~ 7 days and extended into a clot thereafter. Cerebral endothelial cells expressed the TSPs. The expression of TSP-1 and TSP-2 mRNA peaked at 4 and 14 days after collagenase-induced ICH, respectively. Findings in this study suggest that ICH can alter the expression of TSP-1 and TSP-2, which may be involved in modulating angiogenesis in brains following ICH.