Heat shock protein 70 modulates neural progenitor cells dynamics in human neuroblastoma SH-SY5Y cells exposed to high glucose content

Abstract

In the current experiment, detrimental effects of high glucose condition were investigated on human neuroblastoma cells. Human neuroblastoma cell line SH-SY5Y were exposed to 5, 40, and 70mM glucose over a period of 72h. Survival rate and the proliferation of cells were analyzed by MTT and BrdU incorporation assays. Apoptosis was studied by the assays of flow cytometry and PCR array. In order to investigate the trans-differentiation capacity of the cell into mature neurons, we used immunofluorescence imaging to follow NeuN protein level. The transcription level of HSP70 was shown by real-time PCR analysis. MMP-2 and -9 activities were shown by gelatin Zymography. According to data from MTT and BrdU incorporation assay, 70mM glucose reduced cell viability and proliferation rate as compared to control (5mM glucose) and cells treated with 40mM glucose (P<0.05). Cell exposure to 70mM glucose had potential to induced apoptosis after 72h (P<0.05). Our results also demonstrated the sensitivity of SH-SY5Y cells to detrimental effects of high glucose condition during trans-differentiation into mature neuron-like cells. Real-time PCR analysis confirmed the expression of HSP70 in cells under high content glucose levels, demonstrating the possible cell compensatory response to an insulting condition (p(control vs 70mM group)<0.05). Both MMP-2 and -9 activities were reduced in cells being exposed to 70mM glucose. High glucose condition could abrogate the dynamics of neural progenitor cells. The intracellular level of HSP70 was proportional to cell damage in high glucose condition. High glucose condition effect on HSP70 expression and Apoptosis in SH-SY5Y cells.