Differential Effects of Isoxazole-9 on Neural Stem/Progenitor Cells, Oligodendrocyte Precursor Cells, and Endothelial Progenitor Cells.

Seong-Ho Koh,Jing Zhao,Yoko Takahashi,Akihiro Shindo,Noriko Osumi,Eng H Lo,Takakuni Maki,Hong Lin,John D Mcneish,Anna C Liang,Julie C Holder,Tsu Tshen Chuang,Ken Arai,Cesar V Borlongan

doi:10.1371/journal.pone.0138724

Abstract

Adult mammalian brain can be plastic after injury and disease. Therefore, boosting endogenous repair mechanisms would be a useful therapeutic approach for neurological disorders. Isoxazole-9 (Isx-9) has been reported to enhance neurogenesis from neural stem/progenitor cells (NSPCs). However, the effects of Isx-9 on other types of progenitor/precursor cells remain mostly unknown. In this study, we investigated the effects of Isx-9 on the three major populations of progenitor/precursor cells in brain: NSPCs, oligodendrocyte precursor cells (OPCs), and endothelial progenitor cells (EPCs). Cultured primary NSPCs, OPCs, or EPCs were treated with various concentrations of Isx-9 (6.25, 12.5, 25, 50 μM), and their cell numbers were counted in a blinded manner. Isx-9 slightly increased the number of NSPCs and effectively induced neuronal differentiation of NSPCs. However, Isx-9 significantly decreased OPC number in a concentration-dependent manner, suggesting cytotoxicity. Isx-9 did not affect EPC cell number. But in a matrigel assay of angiogenesis, Isx-9 significantly inhibited tube formation in outgrowth endothelial cells derived from EPCs. This potential anti-tube-formation effect of Isx-9 was confirmed in a brain endothelial cell line. Taken together, our data suggest that mechanisms and targets for promoting stem/progenitor cells in the central nervous system may significantly differ between cell types.

Highlights

Neuronal loss is one of the most important and common features in numerous intractable neurological diseases such as stroke, central nervous system (CNS) trauma, Alzheimer’s disease, PLOS ONE | DOI:10.1371/journal.pone.0138724 September 25, 2015Effects of Isx-9 on NSCs oligodendrocyte precursor cells (OPCs) and endothelial progenitor cells (EPCs)
We conducted in vitro proof-of-concept studies wherein Isx-9 was administered to primary rat neural stem/progenitor cells (NSPCs), primary rat oligodendrocyte precursor cells (OPCs), and primary mouse endothelial progenitor cells (EPCs), which together may comprise a representation of the major progenitor/precursor pools relevant for recovering neural, glial and vascular elements in damaged or diseased brain
NSPCs were positive for the standard marker nestin [14,15] and a proliferative marker Ki67 (Fig 1)

Summary

Introduction

Neuronal loss is one of the most important and common features in numerous intractable neurological diseases such as stroke, central nervous system (CNS) trauma, Alzheimer’s disease, PLOS ONE | DOI:10.1371/journal.pone.0138724 September 25, 2015. If endogenous neurogenesis can be enhanced, one might pursue the therapeutic possibility of replacing lost neurons and boosting functional recovery [1,2,3]. This remains a compelling idea and goal, to date, there have been no clinically validated approaches for enhancing neurogenesis and neural replacement. We conducted in vitro proof-of-concept studies wherein Isx-9 was administered to primary rat NSPCs, primary rat oligodendrocyte precursor cells (OPCs), and primary mouse endothelial progenitor cells (EPCs), which together may comprise a representation of the major progenitor/precursor pools relevant for recovering neural, glial and vascular elements in damaged or diseased brain

Material and Methods

Results

Discussion