Dong-Mei Wu1,2, Shan Wang1,2, Xin Wen1,2, Xin-Rui Han1,2, Yong-Jian Wang1,2, Min Shen1,2, Shao-Hua Fan1,2, Juan Zhuang1,3,4, Zi-Feng Zhang1,2, Qun Shan1,2, Meng-Qiu Li1,2, Bin Hu1,2, Chun-Hui Sun1,2, Jun Lu5,6, Yuan-Lin Zheng1,2. 1. Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Science, Jiangsu Normal University, Xuzhou, China. 2. College of Health Sciences, Jiangsu Normal University, Xuzhou, China. 3. School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou, China. 4. Jiangsu Key Laboratory for Eco-Agricultural Biotechnology around Hongze Lake, School of Life Sciences, Huaiyin Normal University, Huaian, China. 5. Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Science, Jiangsu Normal University, Xuzhou, Chinalu-jun75@163.com. 6. College of Health Sciences, Jiangsu Normal University, Xuzhou, Chinalu-jun75@163.com.
Abstract
BACKGROUND/AIMS: Parkinson's disease (PD) is a neurodegenerative movement disease with a high annual incidence. Accumulating evidence demonstrates that microRNAs play important roles in the pathogenesis of multiple neurological disorders, including PD. This study aims to investigate how microRNA-200a (miR-200a) regulates striatal dopamine receptor D2 (DRD2) to affect apoptosis of striatum in rats with PD and to explore the associated mechanism. METHODS: After successfully establishing a PD model by 6-hydroxydopamine injections, PD rats were mainly treated with miR-200a mimics, inhibitors, Forskolin or a combination of miR-200a inhibitors and Forskolin. High-performance liquid chromatography-electrochemical detection (HPLC-ECD) was employed to detect the levels of dopamine, 3, 4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), and chemistry colorimetric methods were applied to detect the levels of malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). A TUNEL assay and immunocytochemical staining were performed to observe apoptosis and tyrosine hydroxylase (TH)-positive cells in the striatum. The expression of miR-200a, DRD2, Bad, Bax, Bcl-2, cAMP and PKA was determined by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blot assays. RESULTS: In the cellular experiments, after transfection with the inhibitor of miR-200a, decreased levels of Bax, GSH-Px, SOD, dopamine, DOPAC and HVA but increased levels of MDA and Bcl-2 were found along with a reduced apoptosis rate and increased TH-positive cell number. In addition, downregulating miR-200a resulted in lower expression of AKT, cAMP and PKA but higher expression of DRD2 and CREB, indicating that the downregulation of miR-200a increases DRD2 expression, which blocks the cAMP/PKA signaling pathway. CONCLUSION: This study provides evidence that the inhibition of miR-200a can repress apoptosis in the striatum via inhibition of the cAMP/PKA signaling pathway by upregulating DRD2 expression in PD rats.
BACKGROUND/AIMS: Parkinson's disease (PD) is a neurodegenerative movement disease with a high annual incidence. Accumulating evidence demonstrates that microRNAs play important roles in the pathogenesis of multiple neurological disorders, including PD. This study aims to investigate how microRNA-200a (miR-200a) regulates striatal dopamine receptor D2 (DRD2) to affect apoptosis of striatum in rats with PD and to explore the associated mechanism. METHODS: After successfully establishing a PD model by 6-hydroxydopamine injections, PDrats were mainly treated with miR-200a mimics, inhibitors, Forskolin or a combination of miR-200a inhibitors and Forskolin. High-performance liquid chromatography-electrochemical detection (HPLC-ECD) was employed to detect the levels of dopamine, 3, 4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), and chemistry colorimetric methods were applied to detect the levels of malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). A TUNEL assay and immunocytochemical staining were performed to observe apoptosis and tyrosine hydroxylase (TH)-positive cells in the striatum. The expression of miR-200a, DRD2, Bad, Bax, Bcl-2, cAMP and PKA was determined by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blot assays. RESULTS: In the cellular experiments, after transfection with the inhibitor of miR-200a, decreased levels of Bax, GSH-Px, SOD, dopamine, DOPAC and HVA but increased levels of MDA and Bcl-2 were found along with a reduced apoptosis rate and increased TH-positive cell number. In addition, downregulating miR-200a resulted in lower expression of AKT, cAMP and PKA but higher expression of DRD2 and CREB, indicating that the downregulation of miR-200a increases DRD2 expression, which blocks the cAMP/PKA signaling pathway. CONCLUSION: This study provides evidence that the inhibition of miR-200a can repress apoptosis in the striatum via inhibition of the cAMP/PKA signaling pathway by upregulating DRD2 expression in PDrats.
Authors: Pengfei Yang; William C Knight; Huifangjie Li; Yingqiu Guo; Joel S Perlmutter; Tammie L S Benzinger; John C Morris; Jinbin Xu Journal: Ann Clin Transl Neurol Date: 2020-12-21 Impact factor: 4.511
Authors: Xiao Hu; Shirong Li; Desislava Met Doycheva; Lei Huang; Cameron Lenahan; Rui Liu; Juan Huang; Ling Gao; Jiping Tang; Gang Zuo; John H Zhang Journal: Oxid Med Cell Longev Date: 2020-10-07 Impact factor: 6.543