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Guo H, Yang L, Liu J, Chen L, Huang Y, Li J. KLF5 promotes the ossification process of ligamentum flavum by transcriptionally activating CX43. J Orthop Surg Res 2024; 19:244. [PMID: 38622696 PMCID: PMC11020807 DOI: 10.1186/s13018-024-04702-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 03/25/2024] [Indexed: 04/17/2024] Open
Abstract
BACKGROUND Ossification of ligamentum flavum (OLF) is a prevalent degenerative spinal disease, typically causing severe neurological dysfunction. Kruppel-like factor 5 (KLF5) plays an essential role in the regulation of skeletal development. However, the mechanism KLF5 plays in OLF remains unclear, necessitating further investigative studies. METHODS qRT-PCR, immunofluorescent staining and western blot were used to measure the expression of KLF5. Alkaline Phosphatase (ALP) staining, Alizarin red staining (ARS), and the expression of Runt-related transcription factor 2 (RUNX2), osteopontin (OPN), and osteocalcin (OCN) were used to evaluate the osteogenic differentiation. Luciferase activity assay and ChIP-PCR were performed to investigate the molecular mechanisms. RESULTS KLF5 was significantly upregulated in OLF fibroblasts in contrast to normal ligamentum flavum (LF) fibroblasts. Silencing KLF5 diminished osteogenic markers and mineralized nodules, while its overexpression had the opposite effect, confirming KLF5's role in promoting ossification. Moreover, KLF5 promotes the ossification of LF by activating the transcription of Connexin 43 (CX43), and overexpressing CX43 could reverse the suppressive impact of KLF5 knockdown on OLF fibroblasts' osteogenesis. CONCLUSION KLF5 promotes the OLF by transcriptionally activating CX43. This finding contributes significantly to our understanding of OLF and may provide new therapeutic targets.
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Affiliation(s)
- Hubing Guo
- The First Department of Orthopaedic Surgery, The First Hospital of Tianshui, Tianshui, Gansu, 741000, China
| | - Lingxia Yang
- Department of Odermatology, The First Hospital of Tianshui, Tianshui, Gansu, 741000, China
| | - Jin Liu
- The First Department of Orthopaedic Surgery, The First Hospital of Tianshui, Tianshui, Gansu, 741000, China
| | - Liqi Chen
- The First Department of Orthopaedic Surgery, The First Hospital of Tianshui, Tianshui, Gansu, 741000, China
| | - Yufeng Huang
- The First Department of Orthopaedic Surgery, The First Hospital of Tianshui, Tianshui, Gansu, 741000, China
| | - Jinsong Li
- Department of Spine Surgery, The Third Xiangya Hospital, Central South University, No.138 Tongzipo Road, Changsha, 410013, Hunan, China.
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Rujeedawa T, Mowforth OD, Davies BM, Yang C, Nouri A, Francis JJ, Aarabi B, Kwon BK, Harrop J, Wilson JR, Martin AR, Rahimi-Movaghar V, Guest JD, Fehlings MG, Kotter MR. Degenerative Thoracic Myelopathy: A Scoping Review of Epidemiology, Genetics, and Pathogenesis. Global Spine J 2023:21925682231224768. [PMID: 38146739 DOI: 10.1177/21925682231224768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2023] Open
Abstract
STUDY DESIGN Literature Review. OBJECTIVE Myelopathy affecting the thoracic spinal cord can arise secondary to several aetiologies which have similar presentation and management. Consequently, there are many uncertainties in this area, including optimal terminology and definitions. Recent collaborative cervical spinal research has led to the proposal and subsequent community adoption of the name degenerative cervical myelopathy(DCM), which has facilitated the establishment of internationally-agreed research priorities for DCM. We put forward the case for the introduction of the term degenerative thoracic myelopathy(DTM) and degenerative spinal myelopathy(DSM) as an umbrella term for both DCM and DTM. METHODS Following PRISMA guidelines, a systematic literature search was performed to identify degenerative thoracic myelopathy literature in Embase and MEDLINE. RESULTS Conditions encompassed within DTM include thoracic spondylotic myelopathy, ossification of the posterior longitudinal ligament, ossification of the ligamentum flavum, calcification of ligaments, hypertrophy of ligaments, degenerative disc disease, thoracic osteoarthritis, intervertebral disc herniation, and posterior osteophytosis. The classic presentation includes girdle pain, gait disturbance, leg weakness, sensory disturbance, and bladder or bowel dysfunction, often with associated back pain. Surgical management is typically favoured with post-surgical outcomes dependent on many factors, including the causative pathology, and presence of additional stenosis. CONCLUSION The clinical entities encompassed by the term DTM are interrelated, can manifest concurrently, and present similarly. Building on the consensus adoption of DCM in the cervical spine and the recent proposal of degenerative cervical radiculopathy(DCR), extending this common nomenclature framework to the terms degenerative spinal myelopathy and degenerative thoracic myelopathy will help improve recognition and communication.
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Affiliation(s)
- Tanzil Rujeedawa
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Oliver D Mowforth
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Benjamin M Davies
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Cylene Yang
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Aria Nouri
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
- Department of Clinical Neurosciences, Geneva University Hospitals, Geneva, Switzerland
| | - Jibin J Francis
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | | | - Brian K Kwon
- Vancouver General Hospital, University of British Columbia, Vancouver, BC, Canada
| | - James Harrop
- Thomas Jefferson University Hospital, Philadelphia, PA, USA
| | | | - Allan R Martin
- Department of Neurosurgery, University of California Davis, Sacramento, CA, USA
| | - Vafa Rahimi-Movaghar
- Department of Neurosurgery, Sina Trauma and Surgery Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - James D Guest
- Department of Neurosurgery and The Miami Project to Cure Paralysis, The Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Michael G Fehlings
- Toronto Western Hospital, University Health Network, University of Toronto, Toronto, ON, Canada
| | - Mark R Kotter
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
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Zuo T, Liu Y, Duan M, Pu X, Huang M, Zhang D, Xie J. Platelet-derived growth factor PDGF-AA upregulates connexin 43 expression and promotes gap junction formations in osteoblast cells through p-Akt signaling. Biochem Biophys Rep 2023; 34:101462. [PMID: 37025987 PMCID: PMC10070375 DOI: 10.1016/j.bbrep.2023.101462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 03/14/2023] [Accepted: 03/23/2023] [Indexed: 03/30/2023] Open
Abstract
Gap junctions, which are mainly composed of connexin units, play an indispensable role in cell morphogenesis, proliferation, migration, adhesion and differentiation of osteoblast lineage cells, and thus mediate bone development, homeostasis and disease occurrence. Platelet-derived growth factor-AA (PDGF-AA) is proved to have a great influence on osteoblast cell lines and is widely applied in the field of bone defect and wound healing. However, the role of PDGF-AA on gap junction formation in the osteoblast lineage remains elusive. In the current study, we aimed to investigate the impact of PDGF-AA on gap junction formation and cell-to-cell communication in the osteoblast lineage and explore its underlying biomechanism. We first found that PDGF-AA promoted cell proliferation and thus increased gap junction formations in living primary osteoblasts and MC3T3-E1 cells through scrape loading and dye transfer (SL/DT) assay. We then confirmed that PDGF-AA enhanced gap junction formations through up-regulation of connexin 43 (Cx43). We next detected the activation of p-Akt signaling in primary osteoblasts and MC3T3-E1 cells that were induced by PDGF-AA. Through inhibitory experiments, we further confirmed that PDGF-AA-mediated gap junction formation occurred via the activation of PI3K/Akt signaling. Taking together, our results provided evidences that PDGF-AA promoted gap junction formation in the osteoblast lineage through p-Akt signaling, which helped to understand the role of PDGF-AA in bone regeneration and diseases.
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Affiliation(s)
- Tao Zuo
- Orthopedics Department, First Clinical College, Xuzhou Medical University, Jiangsu, China
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Yang Liu
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Mengmeng Duan
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Xiaohua Pu
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Minglei Huang
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Demao Zhang
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Jing Xie
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
- National Clinical Research Center for Oral Diseases, Sichuan University, Chengdu, China
- Corresponding author. Principle Investigator of Bone and joint research lab, State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, 610064, China.
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Coexistence of flavum ligament ossification with diffuse idiopathic skeletal hyperostosis in the cervical spine: Review of literature and technical note starting from a rare case. Neurochirurgie 2022; 68:637-647. [PMID: 36087693 DOI: 10.1016/j.neuchi.2022.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Revised: 08/09/2022] [Accepted: 08/15/2022] [Indexed: 11/21/2022]
Abstract
BACKGROUND Cervical flavum ligament ossification (C-OLF) is very rare source of myeloradiculopathy. Less than 100 cases have been reported in modern English literature up to 2020. Association between C-OLF and Diffuse Idiopathic Skeletal Hyperostosis (DISH) at cervical level has never been described. METHODS In this article we performed a systematic review about epidemiology, physiopathology, clinical and surgical management of C-OLF. Moreover, we research its possible association with other cervical spine ligament ossification and in particular with anterior longitudinal ligament ossification. We report a case of 73 years-old woman experiencing mild cervical myeloradiculopathy caused by C6-C7 C-OLF compression and coexistence of DISH at cervico-thoracic level. A brief technical note about intraoperative management of C-OLF has also been described. RESULT Our research found 81 previous reported case of C-OLF. The coexistence of Posterior longitudinal ligament ossification has been reported in 21.3% of C-OLF case. Conversely, we reported the first case describing the association between DISH and C-OLF. Posterior surgical decompression is the only useful treatment providing good long-term functional outcome. Instrumentation should be tailored according to pre-operative findings. CONCLUSIONS C-OLF is a rare source of myeloradiculopathy and it may coexists with DISH probably due to alteration in the cervical mechanical stress and tendency of bone formation in patients harboring coexistent ligament ossifications. According to our result, skip en-bloc microsurgical laminectomy is safe and less invasive method to avoid complication and to provide optimal cervical spinal cord and nerve decompression avoiding CSF-leak.
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