Long-term effect of vital labelling on mixed Schwann cell cultures

Schwann cell tl:transplantation following neuronal injury could encourage r egeneration of spinal cord as well as improving peripheral nerve gap repair . In order to gain a better understanding of the role of transplanted Schwa nn cells in vivo, it is essential to be able to follow their behaviour afte r transplantation. Our aim was to evaluate the suitability of two vital flu orescent labels on the proliferation rate and phenotypic stability of Schwa nn cells, in either pure culture or mixed co-culture. Primary cultures of S chwann cells were obtained from Dark Agouti and Lewis neonatal rats and lab elled with H33342 and PKH26, respectively. In mixed cultures, a 50:50 mixtu re of Dark Agouti and Lewis Schwann cells was present. Labelled cultured ce lls were examined at 1, 2 and 4 weeks for viability and phenotypic marker e xpression of S100, GFAP, p75, MHC I, MHC II and compared with corresponding unlabelled cells. The results showed that although there was no deleteriou s interaction in the mixed cultures, the viability was reduced by the label ling after 3 weeks. Labelled cells could be distinguished up to 3 weeks, bu t there was leakage of H33342 label after 2 weeks. Labelled Schwann cells s howed reduced expression of phenotypic markers, especially p75 when labelle d with H33342. In conclusion, H33342 and PKH26 can be used as fluorescent m arkers of Schwann cells for short-term studies, for a maximum of 2 weeks, b ut different markers may be needed for longer experiments.