Effect of neuroprotective therapies (hypothermia and cyclosporine a) on dopamine-induced apoptosis in human neuronal SH-SY5Y cells

Introduction: This study aimed to evaluate the effect of hypothermia and CyA on neuronal survival after induced injury in a neuronal model. Methods: Human neuroblastoma SH-SY5Y cells were seeded and allowed to grow. To determine whether lower temperatures protect from dopamine-induced apoptosis, cells were treated with dopamine at 100 mu M, at 300 mu M or without dopamine and incubated at 32 degrees C or 37 degrees C for 24 hours. To assess the effect of CyA, cells were pre-incubated with CyA at 37 degrees C and after dopamine was added. Results: After 24 hours of incubation at 37 degrees C, 100 mu M and 300 mu M dopamine induced 42% (SD = 21) and 58% (SD = 7.9) apoptotic SH-SY5 cells, respectively. In cultures at 32 degrees C dopamine-induced apoptosis could be reversed by hypothermia [7% (SD = 1.4) and 3.45% (SD = 1.1) for 100 mu M and 300 mu M, respectively], similar to levels obtained in non-treated cells [2.4% (SD = 1.5)]. Cyclosporine A treatment did not render the expected result, since CyA-pre-treated cells and SH-SY5Y cells showed higher levels of apoptosis than those observed with dopamine alone Conclusions: Hypothermia has a marked protective effect against apoptotic cell death induced by dopamine in a human neuroblastic cell line. The neuroprotective effect of CyA described with other apoptotic cell death stimuli was not demonstrated with our experimental conditions.