Potential for Cell-Transplant Therapy with Human Neuronal Precursors to Treat Neuropathic Pain in Models of PNS and CNS Injury: Comparison of hNT2.17 and hNT2.19 Cell Lines
Figure 5
Sensory behaviors after diabetic peripheral neuropathy (DPN) and intrathecal transplant of hNT2.17 cells. The hNT2.17 cells were transplanted into the lumbar subarachnoid space 5 days after a STZ injection (50 mg/Kg, i.v.) and cords fixed at 42 days after STZ and transplants. (a) Cords were examined for graft survival with the human NuMA marker (arrows) and adjacent sections (b) stained with the antibody marker for GABA (arrows). Many surviving hNT2.17 cells, expressing both NuMA and GABA could be found on the pial surface (arrows), especially over the dorsal lumbar spinal cord. For cell transplant and sensory behavior evaluation, nonviable cells were prepared by suspension of the cells in water, centrifugation, and resuspension in buffer before transplant. All rats received 10 mg/Kg i.p. CsA at the time points corresponding to one day before and 13 days after cell transplant (daily injections). Tactile allodynia behaviors (c) were examined for both a baseline period before STZ injection and for 42 days following STZ. Two groups of STZ-injected rats () were transplanted with either hNT2.17 viable or nonviable hNT2.17 cells at 5 days following STZ, a time when the behavioral hypersensitivity to nonnoxious tactile stimulation was already apparent in the rats. In these three groups (nontransplanted and transplanted), both hindpaws develop (pooled data) increased hypersensitivity, but only the rats with viable hNT2.17 cell grafts recover permanent tactile responses. Saline injected rats never develop tactile allodynia and serve as positive controls. The data (mean + SEM) is from six rats in each group. For thermal hyperalgesia (d), the same rats were examined on alternate days for responses to noxious thermal stimulation and like tactile allodynia, thermal hyperalgesia was apparent immediately before the transplant time, 5 days after STZ. In these three groups (non-transplanted and transplanted), both hindpaws develop (pooled data) increased hypersensitivity, but only the rats with viable hNT2.17 cell grafts recover permanent normal thermal responses. Saline injected rats never develop thermal hyperalgesia and serve as positive controls. The data (mean + SEM) is from six rats in each group. (e) All rats were examined for blood glucose levels before and after STZ and transplant of hNT2.17 cells. Data are the mean ± SEM from >six rats in each group. No treatment had an effect on the vigorous increase in blood glucose levels induced by 50 mg/Kg STZ injection; only the saline injected animals showed no increase in blood glucose.
