Xin-Wen Wang1, Ji-Jun Liu1, Qi-Ning Wu1, Shu-Fang Wu2, Ding-Jun Hao3. 1. Department of Spine Surgery, Honghui Hospital, Xi'an Jiaotong University, Xi'an 710054, PR China. 2. Translational Medicine Center, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, PR China. Electronic address: wushufang_WSF8@163.com. 3. Department of Spine Surgery, Honghui Hospital, Xi'an Jiaotong University, Xi'an 710054, PR China. Electronic address: haodingjunxa@126.com.
Abstract
AIMS: We aim to investigate the role of microRNA-133a (miR-133a) in intervertebral disc destruction by targeting MMP9 in spinal tuberculosis (TB). MAIN METHODS: Rabbit models with spinal TB were established and assigned to the blank, miR-133a mimic, miR-133a inhibitor and negative control (NC) groups. Primary notochordal cells were extracted and separately transfected with miR-133a mimics, miR-133a inhibitor, miR-nonsense sequence control (NC), si-NC and si-MMP9. QRT-PCR and Western blot assay were used to detect the expression of MMP-9, Collagen I, Collagen II and Collagen-X. Gelatin Zymography was performed to detect MMP9 activity. Immunohistochemistry was used to detect the expression of Collagen I, Collagen II and Collagen-X proteins. Osteoclast morphology and the number of osteoclast cells were observed after Tartrate resistant acid phosphatase staining. KEY FINDINGS: MMP9, Collagen-X and Collagen I expression and MMP9 activity were higher while the expression of Collagen II was lower in the miR-133a mimic group than the miR-NC group. MMP9, Collagen-X Collagen I and MMP9 activities were lower and Collagen II expression was higher in the miR-133a inhibitor group than the miR-NC group. Compared with the si-NC group, the si-MMP9 group showed increased Collagen II expression but decreased expression of MMP9, Collagen-X and Collagen I and MMP9 activity. A reduced amount of osteoclast cells exhibited in the miR-133a mimic group while an increased number was seen in the miR-133a inhibitor group compared to the blank group. SIGNIFICANCE: MiR-133a could inhibit Collagen degradation by down-regulating MMP-9 expression to attenuate the destructive effects of spinal TB on intervertebral disc.
AIMS: We aim to investigate the role of microRNA-133a (miR-133a) in intervertebral disc destruction by targeting MMP9 in spinal tuberculosis (TB). MAIN METHODS:Rabbit models with spinal TB were established and assigned to the blank, miR-133a mimic, miR-133a inhibitor and negative control (NC) groups. Primary notochordal cells were extracted and separately transfected with miR-133a mimics, miR-133a inhibitor, miR-nonsense sequence control (NC), si-NC and si-MMP9. QRT-PCR and Western blot assay were used to detect the expression of MMP-9, Collagen I, Collagen II and Collagen-X. Gelatin Zymography was performed to detect MMP9 activity. Immunohistochemistry was used to detect the expression of Collagen I, Collagen II and Collagen-X proteins. Osteoclast morphology and the number of osteoclast cells were observed after Tartrate resistant acid phosphatase staining. KEY FINDINGS:MMP9, Collagen-X and Collagen I expression and MMP9 activity were higher while the expression of Collagen II was lower in the miR-133a mimic group than the miR-NC group. MMP9, Collagen-X Collagen I and MMP9 activities were lower and Collagen II expression was higher in the miR-133a inhibitor group than the miR-NC group. Compared with the si-NC group, the si-MMP9 group showed increased Collagen II expression but decreased expression of MMP9, Collagen-X and Collagen I and MMP9 activity. A reduced amount of osteoclast cells exhibited in the miR-133a mimic group while an increased number was seen in the miR-133a inhibitor group compared to the blank group. SIGNIFICANCE: MiR-133a could inhibit Collagen degradation by down-regulating MMP-9 expression to attenuate the destructive effects of spinal TB on intervertebral disc.