title: Downregulated interleukin 37 expression associated with aggravation of intervertebral disc degeneration.
abstract: Interleukin 37 (IL-37) is an anti-inflammatory cytokine which was proven to be associated with several diseases characterized with excessive-inflammation. The pathologic process of Intervertebral disc degeneration (IVDD) is also companied by uncurbed inflammation, many cytokines were reported presenting in the process. However, there is little IL-37 related knowledge in IVDD up to now. The aim of this study was to investigate whether IL-37 expression in degenerative intervertebral disc (IVD) is different from that in non-degenerative disc and to evaluate the relationship between IL-37 expression, overexpression of pro-inflammatory cytokines and development of degeneration. Human nucleus pulposus samples were obtained from patients with disc degenerative disease and vertebra fractures undergoing discectomy and fusion. Subsequently, expression of IL-37 was assessed by real-time quantitative polymerase chain reaction (RT-PCR) and western blotting. Gene expression level was measured for IL-1α, IL-1β, IL-6, IL-16, TNF-α, TGF-β1 and Smad3. Degree of degeneration was evaluated for MRI with modified Pfirrmann grading system. The results showed that IL-37 had a decreased expression in degenerative samples compared to that in normal samples both at mRNA and protein level. Instead, significant elevated gene expression of IL-1β, IL-16, TNF-α, TGF-β1 and Smad3 were detected in degenerative samples. High correlations were observed between IL-37, IL-1β, IL-16, TGF-β1, Smad3 and degeneration degree of IVD. Downregulation of IL-37 expression appeared to result in overexpression of pro-inflammatory cytokines, such as IL-1β and IL-16, in degenerative IVD and may be a contributor involved in the progression of IVDD.
authors.affiliation: Department of Orthopaedics, Xijing Hospital, Fourth Military Medical University Xi'an, Shaanxi, P. R. China.
authors.forename: Zhong-Yuan
authors.initials: ZY
authors.lastname: Wan
authors.affiliation: Department of Orthopaedics, Xijing Hospital, Fourth Military Medical University Xi'an, Shaanxi, P. R. China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Sun
authors.affiliation: Department of General Dentistry & Emergency, School of Stomatology, Fourth Military Medical University Xi'an, Shaanxi, P. R. China.
authors.forename: Fang
authors.initials: F
authors.lastname: Song
authors.affiliation: Department of Orthopaedics, Xijing Hospital, Fourth Military Medical University Xi'an, Shaanxi, P. R. China.
authors.forename: Yu-Fei
authors.initials: YF
authors.lastname: Chen
authors.affiliation: Department of Orthopaedics, Xijing Hospital, Fourth Military Medical University Xi'an, Shaanxi, P. R. China.
authors.forename: Wei-Lin
authors.initials: WL
authors.lastname: Zhang
authors.affiliation: Department of Orthopaedics, Xijing Hospital, Fourth Military Medical University Xi'an, Shaanxi, P. R. China.
authors.forename: Hai-Qiang
authors.initials: HQ
authors.lastname: Wang
authors.affiliation: Department of Orthopaedics, Xijing Hospital, Fourth Military Medical University Xi'an, Shaanxi, P. R. China.
authors.forename: Zhuo-Jing
authors.initials: ZJ
authors.lastname: Luo
mesh_terms: D000328:Adult; D015153:Blotting, Western; D018450:Disease Progression; D017586:Diskectomy; D015536:Down-Regulation; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000032:analysis; D007375:Interleukin-1 / Q000032:analysis* / Q000235:genetics; D007403:Intervertebral Disc / Q000276:immunology* / Q000293:injuries / Q000473:pathology / Q000601:surgery; D055959:Intervertebral Disc Degeneration / Q000235:genetics / Q000276:immunology* / Q000473:pathology / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000032:analysis; D060888:Real-Time Polymerase Chain Reaction; D012720:Severity of Illness Index; D016103:Spinal Fractures / Q000235:genetics / Q000276:immunology* / Q000473:pathology / Q000601:surgery; D013123:Spinal Fusion; D055815:Young Adult
chemical_list: C508587:IL37 protein, human; D018836:Inflammation Mediators; D007375:Interleukin-1; D012333:RNA, Messenger
keywords: Intervertebral disc degeneration; anti-inflammatory cytokine; interleukin 16; interleukin 37; interleukin-1 beta