title: BMSC paracrine activity attenuates interleukin-1β-induced inflammation and apoptosis in rat AF cells via inhibiting relative NF-κB signaling and the mitochondrial pathway.
abstract: We previously showed that bone mesenchymal stem cells (BMSCs) inhibit interleukin-1 beta (IL-1β) induced degenerative effects in NP cells by their paracrine activity, but the anti-inflammatory and anti-apoptotic effect of BMSC paracrine activity and the relative signaling pathway were not further investigated in annulus fibrosus (AF) cells. In this study, AF cells were exposed to IL-1β, which was applied to mimic intervertebral disc degeneration (IDD)in vitro. Indirect co-culture with BMSCs in a transwell co-culture system reduced the activity of nuclear factor-κB-p65 (NF-κB-p65) through the restoration of its inhibitor IκBa. Real time polymerase chain reaction (PT-PCR) and Western blotting revealed that the up-regulation of MMP-3 and MMP-13 induced by IL-1β were impeded by BMSC co-culture, and the decrease in aggrecan, collagen I and TIMP-1 were reversed. An ELISA showed that the increased inflammatory factors, such as nitrite, prostaglandin E-2 (PGE-2), IL-6 and cyclooxygenase-2 (COX-2), were decreased by the BMSC co-culture. Furthermore, the apoptosis rate of AF cells were detected by flow cytometry, and the apoptosis-related proteins, such as Bax, Bcl-2 and caspase-3, were analyzed by Western blotting and ELISA. The changes in mitochondrial membrane potentials were also detected by confocal microscopy. The results showed that IL-1β induced apoptosis of AF cells was attenuated by co-culturing, which suppressed the functions of the mitochondria function. We suggest that BMSC paracrine activity has an anti-inflammation effect and anti-apoptotic effect on IDD, and it is mediated, at least in part, via the relative NF-κF and mitochondrial apoptotic pathways in AF cells.
authors.affiliation: Department of Orthopaedics, Changzheng Hospital Affiliated With Second Military Medical University 415 Fengyang Road, Shanghai 200003, PR China.
authors.forename: Jinquan
authors.initials: J
authors.lastname: Hu
authors.affiliation: Department of Gynaecology and Obstetrics, Nanjing Drum Tower Hospital, Nanjing University School of Medicine Nanjing 210008, Jiangsu, PR China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Yan
authors.affiliation: Department of Orthopaedics, Changzheng Hospital Affiliated With Second Military Medical University 415 Fengyang Road, Shanghai 200003, PR China.
authors.forename: Changgui
authors.initials: C
authors.lastname: Shi
authors.affiliation: Department of Orthopaedics, Changzheng Hospital Affiliated With Second Military Medical University 415 Fengyang Road, Shanghai 200003, PR China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Tian
authors.affiliation: Department of Orthopaedics, Changzheng Hospital Affiliated With Second Military Medical University 415 Fengyang Road, Shanghai 200003, PR China.
authors.forename: Peng
authors.initials: P
authors.lastname: Cao
authors.affiliation: Department of Orthopaedics, Changzheng Hospital Affiliated With Second Military Medical University 415 Fengyang Road, Shanghai 200003, PR China.
authors.forename: Wen
authors.initials: W
authors.lastname: Yuan
keywords: BMSCs; Interleukin-1 beta (IL-1β); annulus fibrosus; apoptosis; disc degeneration; paracrine