Yu-yan Tan1, Li Wu2, Zong-bo Zhao3, Ying Wang4, Qin Xiao5, Jun Liu6, Gang Wang7, Jian-fang Ma8, Sheng-di Chen9. 1. Department of Neurology and Institute of Neurology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China. Electronic address: rabbit82@gmail.com. 2. Department of Neurology and Institute of Neurology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China. Electronic address: breezy51@163.com. 3. Department of Neurology and Institute of Neurology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China. Electronic address: san_pi_love@126.com. 4. Department of Neurology and Institute of Neurology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China. Electronic address: wang-ying@medmail.com.cn. 5. Department of Neurology and Institute of Neurology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China. Electronic address: xiaoqin67@medmail.com.cn. 6. Department of Neurology and Institute of Neurology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China. Electronic address: jly0520@hotmail.com. 7. Department of Neurology and Institute of Neurology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China. Electronic address: wgneuron@hotmail.com. 8. Department of Neurology and Institute of Neurology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China. Electronic address: mjf74@163.com. 9. Department of Neurology and Institute of Neurology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China. Electronic address: chen_sd@medmail.com.cn.
Abstract
BACKGROUND: Recent studies highlight the role of DNA methylation in the pathogenesis of Parkinson's disease (PD). However, there is a paucity of studies exploring the role of blood-based DNA methylation in PD. We aimed to explore identifiable epigenetic biomarkers for PD by analyzing the methylation status of α-synuclein (SNCA) and leucine-rich repeat kinase 2 (LRRK2) in leukocytes. METHODS: Bisulfite Specific PCR-based Sequencing method was used for semi-quantitative detection of methylation status of CpG islands in SNCA and LRRK2 promoter regions. Bisulfite Specific Cloning-based Sequencing method was used for further quantitative examination of CpG-2 methylation of SNCA. mRNA level was also detected in leukocytes. RESULTS: Semi-quantitative detection showed that the methylation status of SNCA CpG-2 differed between PD patients and normal controls, while there was no difference in CpG-1 of SNCA or in LRRK2 promoter. Further quantitative analysis by clonal assay showed that the CpG-2 of SNCA was hypomethylated in PD patients compared with the normal control (5.90% versus 7.69%, P=0.034). Moreover, among the 14 CpG sites of CpG-2, the 2nd, 4th and 9th CpG sites were significantly hypomethylated in PD patients. In subgroups of PD, the methylation level decreased in the early-onset PD patients (P=0.001). RT-PCR examination showed that SNCA mRNA was increased in PD patients compared with normal control (P=0.003). CONCLUSIONS: Our results indicated that the methylation level of SNCA CpG-2, especially that of the 2nd, 4th and 9th CpG sites in leukocytes might have great potential to be a useful and informative biomarker in PD diagnosis and treatment.
BACKGROUND: Recent studies highlight the role of DNA methylation in the pathogenesis of Parkinson's disease (PD). However, there is a paucity of studies exploring the role of blood-based DNA methylation in PD. We aimed to explore identifiable epigenetic biomarkers for PD by analyzing the methylation status of α-synuclein (SNCA) and leucine-rich repeat kinase 2 (LRRK2) in leukocytes. METHODS:Bisulfite Specific PCR-based Sequencing method was used for semi-quantitative detection of methylation status of CpG islands in SNCA and LRRK2 promoter regions. Bisulfite Specific Cloning-based Sequencing method was used for further quantitative examination of CpG-2 methylation of SNCA. mRNA level was also detected in leukocytes. RESULTS: Semi-quantitative detection showed that the methylation status of SNCA CpG-2 differed between PDpatients and normal controls, while there was no difference in CpG-1 of SNCA or in LRRK2 promoter. Further quantitative analysis by clonal assay showed that the CpG-2 of SNCA was hypomethylated in PDpatients compared with the normal control (5.90% versus 7.69%, P=0.034). Moreover, among the 14 CpG sites of CpG-2, the 2nd, 4th and 9th CpG sites were significantly hypomethylated in PDpatients. In subgroups of PD, the methylation level decreased in the early-onset PDpatients (P=0.001). RT-PCR examination showed that SNCA mRNA was increased in PDpatients compared with normal control (P=0.003). CONCLUSIONS: Our results indicated that the methylation level of SNCA CpG-2, especially that of the 2nd, 4th and 9th CpG sites in leukocytes might have great potential to be a useful and informative biomarker in PD diagnosis and treatment.
Authors: Maria Angeliki S Pavlou; Nicoló Colombo; Sandra Fuertes-Alvarez; Sarah Nicklas; Laura Gonzalez Cano; Maria C Marín; Jorge Goncalves; Jens C Schwamborn Journal: Mol Neurobiol Date: 2016-06-23 Impact factor: 5.590