Aim: 

ALR is a liver growth factor with a strong anti-apoptotic activity; our previous studies have demonstrated the protective effect of ALR on H2O2-induced apoptosis in the human neuroblastoma cell line SH-SY5Y. The aim of the present study was to explore both effect and role of RA and ALR in terms of SH-SY5Y cell survival and differentiation in media supplemented with different serum concentrations.

Methods: 

Cultures of the SH-SY5Y cells were maintained in either DMEMs supplemented with 10, 2 or 0.2% FCS, or in defined medium (DM). 10mM RA and 100ng/ml ALR were added to the culture media singularly or together. Cell viability was tested using the MTT assay. The expression of anti-apoptotic marker Bcl-2 and of differentiation marker Gap43 was assessed by Western blot.

Results: 

RA was found to significantly decrease cell viability and increase neurite outgrowth, whereas ALR alone had no effect on cell proliferation and differentiation in all the different culture media under study. When RA and ALR were added together to a low-serum culture medium, SH-SY5Y cell viability was enhanced. In addition, treatment of SH-SY5Y with ALR was found to increase Bcl2 expression compared to treatment with RA alone, while Gap43 expression was observed to decrease.

Conclusion: 

Our results suggest that ALR can protect SH-SY5Y cells against the apoptotic effect of RA, but also that this protein has an inhibitory effect on cell differentiation. Further work on this subject is underway in our laboratories.