Experimental and clinical factors influencing long-term stable in vitro expansion of multipotent neural cells from human adult temporal lobes.

Autologous adult human neural stem cells may be used for regenerative cell therapies bypass potential ethical problems. However, stable in vitro expansion protocols and experimental/clinical factors influencing primary cultures need to be further elucidated for clinically applicable techniques. To address these issues, we obtained biopsy specimens from 23 temporal lobe epilepsy patients and adult human multipotent neural cells (ahMNCs) were primarily cultured in a defined attachment culture condition. When the success of primary cultures was defined as stable expansion of cells (>ten in vitro passages) and expression of NSC markers, success rate of the primary culture was 39% (nine of 23 temporal lobes). During the long-term expansion, expressions of NSC markers and differentiation potentials into astrocytes and neurons were maintained. After the 18th sub-culture, spontaneous senescence and differentiation were observed, and the cultivated ahMNCs ceased their proliferation. The culture results were not affected by seizure characteristics; however, an older age (>40 years) and a smaller sample volume (<2 ml) were found to exert negative influences on the primary culture results. Furthermore therapeutic effects of ahMNCs against stroke were analyzed in an animal model. Transplantation of ahMNCs cells reduced infarction volumes and enhanced motor activity, significantly. The results here would provide promising experimental and clinical strategy of using patient-specific autologous ahMNCs in regenerative medicine in the future.