Analysis of grafted Thy1-YFP-16 positive cells in mouse brains affected by ischaemic stroke

Abstract

Stroke is an aggressive neurological disorder which may be haemorrhagic or ischaemic. Neural stem cells (NSCs) are a wide cell population which can differentiate into neurons and glia cells. In this study we induced stroke in mice by occlusion of the middle cerebral artery. Twenty-four hours post-surgery, NSCs were transplanted into the mouse brains. For purpose of this study two mouse strains were used, wild type and transgenic B6.Cg-Tg(Thy1-YFP)16Jrs/J (Thy1 YFP-16) kept on the same background. In total nine embryos and twelve adult animals were used: two pregnant females, five males for middle cerebral artery occlusion (MCAO), and five males for the control group. Thy1 YFP16 cells express YFP in approximately 22% neurons under the influence of Thy1 promoter. The main goal of this study was to analyse the grafted cells eight weeks post transplantation in these two groups of animals. A significant difference in TUBB3 positive neurons (P=0.0340) and GFAP positive astrocytes (P=0.0004) between MCAO and the control group was found. Moreover, a significantly higher percentage of Thy1-YFP cells was found in the control group of animals (P=0.0003). Pearson’s coefficient of colocalization showed colocalization between Thy1-YFP and TUBB3 positive neurons, but there was no colocalization between Thy1-YFP and GFAP positive astrocytes. On the basis of our data we can conclude that Thy1-YFP cells may serve for transplantation and cell tracing studies.