Association Between PLA2G6Gene Polymorphisms And Parkinson’s Disease&the Mechanism Study Of PLA2G6Enzyme Activity Decline In The Cell Death

Background:Parkinson’s disease (PD), also known as paralysis agitans, is one of the most common neurodegenerative diseases. In recent years, the relationship between single nucleotide polymorphisms (SNP) and the risk of Parkinson’s disease becomes a central issue, and the single nucleotide polymorphisms in the population distribution have obvious racial specificity. The PLA2G6gene, also called PARK14, was found in2009when Paisan-Ruiz et al studying the autosomal recessive hereditary PD pedigrees, but until now there is still no study about the PLA2G6gene single nucleotide polymorphisms and the risk of PD. Objective:This part of study aims at exploring the relationship between the four of selected PLA2G6single nucleotide polymorphic loci and sporadic Parkinson’s disease. Methods:In this study, direct DNA sequencing methods were used to detect the531patients with sporadic Parkinson’s disease and561healthy people of Han population, four SNPs of PLA2G6gene were selected:rs4375, rs2267369, rs132985and rs2284063. Results:The results of the association study of4tag SNPs in Chinese PD patients and unrelated controls are as follows:1. The SNPs (rs4375, rs2267369, rs132985, rs2284063) are common single nucleotide polymorphic loci in Han population in China, which are not risk factors of Parkinson’s disease.2. Genotype and allele frequencies of all SNPs in patients with either early-onset (EOPD,≤50years) or late-onset (>50years) PD revealed no statistically significant differences from controls.3. The rs132985allele frequency showed a difference in male patients but not in female patients after adjustment for age; Genotype and allele frequencies of rs4375、rs2267369、rs2284063in patients with either male or female PD revealed no statistically significant differences from controls.4. The haplotype rs132985A—2284063C was associated with the increased risk of developing PD in our case control sample set. Conclusion:The results showed that the four single nucleotide polymorphic loci selected were common in Chinese Han population and were not the risk factors in Parkinson’s disease. Background:The PLA2G6gene located at22q13.1, encodes a protein called iPLA2VIA or iPLA2β, there is still no paper reported about this gene in the pathogenesis of Parkinson’s. IPLA2β is one of the phospholipase A2(PLA2), which plays an important role in maintaining the membrane fluidity. Objective:This part aimed at study the relationship between the reduction of iPLA2βactivity and apoptosis. Methods:The specific inhibitor S-BEL was used to pre-incubate SH-SY5Y cells, the activity of iPLA2β enzyme was detected, and MTT, Western Blots, transmission electronic microscopy, Flow Cytometry were used to detect the indicators of related mitochondrial and apoptosis. Results:1. Different concentrations of S-BEL pre-incubation can lead to the decrease of SH-SY5Y cells activity.2. Different concentrations of S-BEL pre-incubation of SH-SY5Y cells can lead to decline in mitochondrial membrane potential.3. Different concentrations of S-BEL pre-incubation can result in cytochrome C release from mitochondrial into the cytoplasm in SH-SY5Y cells.4. Different concentrations of S-BEL pre-incubation can result in caspase9, caspase3activation in SH-SY5Y cells.5. Different concentrations of S-BEL pre-incubation can result in SH-SY5Y cell apoptosis using Annexin-PI detection. Conclusion:The decrease of iPLA2(3activity may cause mitochondrial dysfunction which leads to apoptosis. Of course, our experiments were done on the cellular level and animal model is on the agenda. Background:The mutation of PLA2G6gene can lead to infantile neuroaxonal dystrophy (INAD) and autosomal recessive genetic PD, because in the globus pallidus region of part of the INAD and autosomal recessive PD patients there were MRI visible iron deposition, and therefore the disease of the mutation of PLA2G6gene is classified as the brain iron deposition disease—2(neurodegenerative disorders with brain iron accumulation, NBIA—2). In sporadic patients of Parkinson’s disease, the iron levels have been confirmed to be increased in substantia nigra (SN), and the increased iron proved to be one of the important causes of Parkinson’s disease. Objective:Whether the decrease of the iPLA2β activity may cause the disturbance of iron metabolism then leading to apoptosis become the third part of our study. Methods:This section used Perls iron staining; Western Blots to observe whether there are changes in the deposition of iron and iron metabolism related proteins. Results:The results are as follows:1. There was no intracellular iron deposition in SH-SY5Y cells incubated with different concentrations of S-BEL.2. SH-SY5Y cells were pre-incubated iron chelator deferoxamine, but the protein level of caspase3caused by S-BEL incubation can not be reduced.3. There was no disorder for the expression of iron transport protein for SH-SY5Y cells.4. There was no intracellular iron deposition in Neuro2a cells incubated with different concentrations of S-BEL.5. Neuro2a cells were pre-incubated iron chelator deferoxamine, but cells activity caused by S-BEL incubation can not be rescued.6. There was no disorder for the expression of iron transport protein for Neuro2a cells. Conclusion:The decrease of iPLA2P activity may not cause iron deposition. Of course, our experiments were done on the cellular level and animal model is on the agenda.