title: Up-regulation of acid-sensing ion channels in the capsule of the joint in frozen shoulder.
abstract: The purpose of this study was to evaluate the expression of acid-sensing ion channels (ASICs) in the capsule and synovial fluid of patients with frozen shoulder. Capsular tissue and synovial fluid were obtained from 18 patients with idiopathic frozen shoulder (FS group) and 18 patients with instability of the shoulder (control group). The expressions of ASIC1, ASIC2, and ASIC3 in the capsule were determined using the reverse transcriptase-polymerase chain reaction, immunoblot analysis, and immunohistochemistry (IHC). The concentrations in synovial fluid were evaluated using an enzyme-linked immunosorbent assay. The mRNA expression of ASIC1, ASIC2 and ASIC3 in the capsule were significantly increased in the FS group compared with the control group. The protein levels of these three ASICs were also increased. The increased expressions were confirmed by IHC. Of the ASICs, ASIC3 showed the greatest increase in both mRNA and levels of expression compared with the control group. The levels of ASIC1 and ASIC3 in synovial fluid were significantly increased in the FS group. This study suggests that ASICs may play a role as mediators of inflammatory pain and be involved in the pathogenesis of frozen shoulder.
authors.affiliation: Keimyung University Dongsan Medical Center, 56 Dalseong-ro, Jung-gu, Daegu 700-712, South Korea.
authors.forename: C H
authors.initials: CH
authors.lastname: Cho
authors.affiliation: Keimyung University Dongsan Medical Center, 56 Dalseong-ro, Jung-gu, Daegu 700-712, South Korea.
authors.forename: Y M
authors.initials: YM
authors.lastname: Lho
authors.affiliation: Keimyung University Dongsan Medical Center, 56 Dalseong-ro, Jung-gu, Daegu 700-712, South Korea.
authors.forename: E
authors.initials: E
authors.lastname: Ha
authors.affiliation: Keimyung University Dongsan Medical Center, 56 Dalseong-ro, Jung-gu, Daegu 700-712, South Korea.
authors.forename: I
authors.initials: I
authors.lastname: Hwang
authors.affiliation: Keimyung University Dongsan Medical Center, 56 Dalseong-ro, Jung-gu, Daegu 700-712, South Korea.
authors.forename: K S
authors.initials: KS
authors.lastname: Song
authors.affiliation: Keimyung University Dongsan Medical Center, 56 Dalseong-ro, Jung-gu, Daegu 700-712, South Korea.
authors.forename: B W
authors.initials: BW
authors.lastname: Min
authors.affiliation: Keimyung University Dongsan Medical Center, 56 Dalseong-ro, Jung-gu, Daegu 700-712, South Korea.
authors.forename: K C
authors.initials: KC
authors.lastname: Bae
authors.affiliation: Keimyung University Dongsan Medical Center, 56 Dalseong-ro, Jung-gu, Daegu 700-712, South Korea.
authors.forename: D H
authors.initials: DH
authors.lastname: Kim
mesh_terms: D062565:Acid Sensing Ion Channels / Q000096:biosynthesis / Q000378:metabolism*; D002062:Bursitis / Q000378:metabolism* / Q000503:physiopathology; D006801:Humans; D007150:Immunohistochemistry; D017746:Joint Capsule / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D013582:Synovial Fluid / Q000378:metabolism; D015854:Up-Regulation / Q000502:physiology*
chemical_list: C568266:ASIC1 protein, human; C568424:ASIC2 protein, human; C112231:ASIC3 protein, human; D062565:Acid Sensing Ion Channels; D012333:RNA, Messenger
keywords: Frozen shoulder; Joint capsule; Acid-Sensing Ion Channel