title: Targeted suppression of chaperone-mediated autophagy by miR-320a promotes α-synuclein aggregation.
abstract: Chaperone-mediated autophagy (CMA) is involved in wild-type α-synuclein degradation in Parkinson's disease (PD), and LAMP2A and Hsc 70 have recently been indicated to be deregulated by microRNAs. To recognize the regularory role of miR-320a in CMA and the possible role in α-synuclein degradation, in the present study, we examined the targeting and regulating role of miR-320 in Hsc 70 expression. We first constructed an α-synuclein-overexpressed human neuroblastoma cell line, SH-SY5Y-Syn(+), stably over-expressing wild-type α-synuclein and sensitive to an autophagy inhibitor, which exerted no effect on the expression of LAMP2A and Hsc 70. Then we evaluated the influence on the CMA by miR-320a in the SH-SY5Y-Syn(+) cells. It was shown that miR-320a mimics transfection of specifically targeted Hsc 70 and reduced its expression at both mRNA and protein levels, however, the other key CMA molecule, LAMP2A was not regulated by miR-320a. Further, the reduced Hsc 70 attenuated the α-synuclein degradation in the SH-SY5Y-Syn(+) cells, and induced a significantly high level of α-synuclein accumulation. In conclusion, we demonstrate that miR-320a specifically targeted the 3' UTR of Hsc 70, decreased Hsc 70 expression at both protein and mRNA levels in α-synuclein-over-expressed SH-SY5Y cells, and resulted in significant α-synuclein intracellular accumulation. These results imply that miR-320a might be implicated in the α-synuclein aggravation in PD.
authors.affiliation: Department of Neurosurgery, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong, China. guobinli434@163.com.
authors.forename: Guobin
authors.initials: G
authors.lastname: Li
authors.affiliation: Department of Neurosurgery, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong, China. haiying_yangqd@163.com.
authors.forename: Haiying
authors.initials: H
authors.lastname: Yang
authors.affiliation: Department of Neurosurgery, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong, China. dezhzhu888@163.com.
authors.forename: Dezhang
authors.initials: D
authors.lastname: Zhu
authors.affiliation: Department of Neurosurgery, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong, China. huih_huang@163.com.
authors.forename: Hui
authors.initials: H
authors.lastname: Huang
authors.affiliation: Department of Neurosurgery, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong, China. guoyuan626liu@163.com.
authors.forename: Guoyuan
authors.initials: G
authors.lastname: Liu
authors.affiliation: Department of Neurosurgery, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong, China. pengqdlun@163.com.
authors.forename: Peng
authors.initials: P
authors.lastname: Lun
mesh_terms: D020413:3' Untranslated Regions; D001343:Autophagy; D045744:Cell Line, Tumor; D050883:HSC70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D052119:Lysosomal-Associated Membrane Protein 2 / Q000235:genetics / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D066263:Protein Aggregation, Pathological; D059748:Proteolysis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051844:alpha-Synuclein / Q000378:metabolism*
chemical_list: D020413:3' Untranslated Regions; D050883:HSC70 Heat-Shock Proteins; C494371:HSPA8 protein, human; C497811:LAMP2 protein, human; D052119:Lysosomal-Associated Membrane Protein 2; C572916:MIRN320 microRNA, human; D035683:MicroRNAs; D012333:RNA, Messenger; D051844:alpha-Synuclein