Isolation and characterization of cells with neurogenic potential from adult skeletal muscle.

Autologous cell therapies in neurodegenerative diseases and stroke will require an efficient generation of neuroprogenitors or neurons. We have previously shown that presumptive neural progenitors can be obtained from a candidate stem cell population isolated from adult skeletal muscle. Here we describe experimental conditions to isolate and characterize the cells with neurogenic potential from this population. Candidate stem cell population was isolated from adult skeletal muscle and expanded for selection during at least 30 cell divisions. FACS analysis revealed that this population was homogeneous with respect to CD45 (-), CD34 (-), and heterogeneous for CD90 (Thy-1) expression. The population was separated by cell sorting into three sub-populations based on CD90 expression (CD90-, CD90+, and CD90++) and each population expanded rapidly as free-floating spheres. When dissociated and plated in a neuronal differentiation medium, a large number of CD90+ cells acquired morphological characteristics of neuroprogenitors and neurons, and expressed markers of neurons but no markers of glial or muscle cells. In contrast, CD90- and CD90++ cells lacked this ability. Comparison of CD90+ and CD90- populations may be useful for studying the molecular characteristics defining the neuronal potential of stem cells from adult muscle. The selection of CD90+ expressing cells, combined with the growth conditions presented here, allows for rapid generation of a large number of cells which may be useful for autologous cell replacement therapies in the central nervous system.