1-Methyl-4-phenyl-pyridinium time-dependently alters expressions of oxoguanine glycosylase 1 and xeroderma pigmentosum group F protein in PC12 cells

Abstract

Objective To determine if DNA excision repair enzymes oxoguanine glycosylase 1 (OGG1) and xeroderma pigmentosum group F protein (XPF) are involved in the pathogenesis of Parkinson's disease (PD) in a cell model. Methods PC12 cells were treated with 1-Methyl-4-phenylpyridine ion (MPP + ) for various periods of time to induce oxidative DNA damage. MTT assay was used to determine cell viability. Immunocytochemistry with antibody against 8-hydroxy-2'-deoxyguanosine (8-oxodG) was used to evaluate oxidative DNA damage. Immunoblotting was used to detect the protein levels of OGG1 and XPF. Results MPP + treatment (1 mmol/L) for 18 h and 24 h reduced cell viability to 78.6% and 70.3% of the control, respectively, in a time-dependent way. MPP + increased the immunoreactivity of 8-oxodG in the cytoplasm at 3 h and in the nucleus at 24 h of treatment. With the treatment of MPP + , the expression of OGG1 was significantly increased at 1 h, reaching a peak at 3 h, and then it was decreased at 24 h, as compared to that with vehicle treatment. The same effect was exerted on XPF level, except that the XPF level reached a peak at 18 h of MPP + treatment. Moreover, the maximally-increased protein level of OGG1 by MPP + was approximately 2-fold higher than that of XPF. Conclusion MPP + treatment could timedependently induce increases in OGG1 and XPF expressions in PC12 cells. Also, this study indicates that the base and nucleotide excision repair pathways may be compensatorily activated in the early stage of pathogenesis in the cells after MPP + treatment.

Diabetes-induced Central Neuritic Dystrophy and Cognitive Deficits Are Associated with the Formation of Oligomeric Reticulon-3 via Oxidative Stress

“…Immunohistochemical Staining for 8-OxodG-The immunostaining were carried out based on a previous report (34). Briefly, the sections were incubated with 100 g/ml RNase in 10 mM Tris buffer containing 1 mM EDTA, 400 mM NaCl (pH 7.5) for 60 min at 37°C and with 2 N HCl for 10 min at room temperature and then neutralized with 50 mM Tris buffer for 5 min at room temperature.…”

Genetic modification of H2AX renders mesenchymal stromal cell–derived dopamine neurons more resistant to DNA damage and subsequent apoptosis

“…To further test if BMSC-derived DA neurons bearing H2AX (Y142F) are more resistant to DNA damage after exposure to oxidative damage, WT, Y142F and Null were treated with or without MPP+ for 2 days as MPP+ is a parkinsonian neurotoxin well-known to induce oxidative DNA damage and subsequent apoptosis (40–42). After exposure to MPP+, cells were subjected to different assays.…”

Activated or Impaired: An Overview of DNA Repair in Neurodegenerative Diseases

“…The abundance of OGG1 in the substantia nigra is increased in the brains of PD patients [ 112 ]. Consistently, in PC12 cells, treatment with toxins that induce PD-like injury, such as melanin, MnCl 2 or 1-methyl-4-phenylpyridinium (MPP + ), elevated the expression level of OGG1 [ 113 , 114 ]. Unfortunately, the trend of OGG1 activity is still unclear.…”