Sheng-Qi Wang

Protective Effect of (±) Isoborneol Against 6-OHDA-Induced Apoptosis in SH-SY5Y Cells

Oxidative stress caused by dopamine (DA) may play an important role in the pathogenesis of Parkinson’s disease (PD). (±) Isoborneol is a monoterpenoid alcohol present in the essential oils of numerous medicinal plants and is a known antioxidant. In this study, we investigated the neuroprotective effect of isoborneol against 6-hydroxydopamine (6-OHDA)-induced cell death in human neuroblastoma SH-SY5Y cells. Pretreatment of SH-SY5Y cells with isoborneol significantly reduced 6-OHDA-induced generation of reactive oxygen species (ROS) and 6-OHDA-induced increases in intracellular calcium. Furthermore, apoptosis induced by 6-OHDA was reversed by isoborneol treatment. Isoborneol protected against 6-OHDA-induced increases in caspase-3 activity and cytochrome C translocation into the cytosol from mitochondria. Isoborneol prevented 6-OHDA from decreasing the Bax/Bcl-2 ratio. We also observed that isoborneol decreased the activation of c-Jun N-terminal kinase and induced activation of protein kinase C (PKC) which had been suppressed by 6-OHDA. Our results indicate that the protective function of isoborneol is dependent upon its antioxidant potential and strongly suggest that isoborneol may be an effective treatment for neurodegenerative diseases associated with oxidative stress.

Proteomic Analysis of Ionizing Radiation-Induced Proteins at the Subcellular Level

Irradiation induces a series of liver diseases. However the molecular mechanisms involving in the process of liver diseases induced by irradiation are still unclear. Subcellular proteomics provides a method to understand regional differences in protein expression levels. With accumulating evidence in the literature that new proteins are implicated in radiation response, in the present study, C57BL/6 mice were treated with irradiation, liver cell homogenates were subfractionated by differential ultracentrifugation into nuclei, mitochondria and cytosol, which were subjected to 2-DE to generate the proteomic maps of these fractions. The differentially expressed proteins in the nuclei, mitochondria and cytosol compartment of liver at 24 and 48 h after exposure to 20 Gy irradiation compared to control were identified by MALDI-TOF MS respectively. Total 37 proteins at 24 h and 29 proteins at 48 h were matched with known proteins after database searching in nuclei, mitochondria and cytosol, respectively, among which nine proteins exhibited changes at both time points. Most of these proteins are involved in antioxidant response, energy metabolism, molecular chaperones and inflammatory response. More antioxidant-associated proteins were induced at 48 h than 24 h. Reverse transcriptase polymerase chain reaction (RT-PCR) and Western blotting further validated 2-DE results of two of these proteins. It is feasible that the differential proteins identified in this study have a biological significance and may provided clues for understanding the mechanism of injury in liver induced by irradiation.