The expression of FOXJ1 in neurogenesis after transient focal cerebral ischemia.

OBJECTIVE AND BACKGROUND

FOXJ1 is a member of the Forkhead/winged-helix (Fox) family of transcription factors, which is required for the differentiation of the cells acting as adult neural stem cells which participate in neurogenesis and give rise to neurons, astrocytes, oligodendrocytes. The expression pattern of FOXJ1 in the brain after cerebral ischemia has so far not been described. In the current study, we investigated the expression pattern of FOXJ1 in the rat brain after cerebral ischemia by animal model.

METHODS

We performed a middle cerebral artery occlusion (MCAO) model in adult rats and investigated the expression of FOXJ1 in the brain by Western blotting and immunochemistry; double immunofluorescence staining was used to analyze FOXJ1's co-expression with Ki67.

RESULTS

Western blot analysis showed that the expression of FOXJ1 was lower than normal and sham-operated brain after cerebral ischemia, but the level of FOXJ1 gradually increased from Day 1 to Day 14. Immuohistochemical staining suggested that the immunostaining of FOXJ1 deposited strongly in the ipsilateral and contralateral hemisphere in the cortical penumbra (CP). There was no FOXJ1 expression in the ischemic core (IC). The positive cells in the cortical penumbra might migrate to the ischemic core. In addition, double immunofluorescence staining revealed that FOXJ1 was co-expressed with mAP-2 and gFAP, and Ki67 had the colocalization with NeuN, GFAP, and FOXJ1.

CONCLUSIONS

All our findings suggest that FOXJ1 plays an important role on neuronal production and neurogenesis in the adult brain after cerebral ischemia.