1
|
Easson GWD, Savadipour A, Gonzalez C, Guilak F, Tang SY. TRPV4 differentially controls inflammatory cytokine networks during static and dynamic compression of the intervertebral disc. JOR Spine 2023; 6:e1282. [PMID: 38156056 PMCID: PMC10751971 DOI: 10.1002/jsp2.1282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 08/04/2023] [Accepted: 09/02/2023] [Indexed: 12/30/2023] Open
Abstract
Background The ion channel transient receptor potential vanilloid 4 (TRPV4) critically transduces mechanical forces in the IVD, and its inhibition can prevent IVD degeneration due to static overloading. However, it remains unknown whether different modes of loading signals through TRPV4 to regulate the expression of inflammatory cytokines. We hypothesized that TRPV4 signaling is essential during static and dynamic loading to mediate homeostasis and mechanotransduction. Methods Mouse functional spine units were isolated and either cyclically compressed for 5 days (1 Hz, 1 h, 10% strain) or statically compressed (24 h, 0.2 MPa). Conditioned media were monitored at 6 h, 24 h, 2 days, and 5 days, with and without TRPV4 inhibition. Effects of TRPV4 activation was also evaluated without loading. The media was analyzed for a panel of 44 cytokines using a microbead array and then a correlative network was constructed to explore the regulatory relationships during loading and TRPV4 inhibition. After the loading regimen, the IVDs were evaluated histologically for degeneration. Results Activation of TRPV4 led to an increase interleukin-6 (IL-6) family of cytokines (IL-6, IL-11, IL-16, and leukemia inhibitory factor [LIF]) and decreased the T-cell (CCL3, CCL4, CCL17, CCL20, CCL22, and CXCL10) and monocyte (CCL2 and CCL12) recruiting chemokines by the IVD. Dynamic and static loading each provoked unique chemokine correlation networks. The inhibition of TRPV4 during dynamic loading dysregulated the relationship between LIF and other cytokines, while the inhibition of TRPV4 during static loading disrupted the connectivity of IL-16 and VEGFA. Conclusions We demonstrated that TRPV4 critically mediates the cytokine production following dynamic and static loading. The activation of TRPV4 upregulated a diverse set of cytokines that may suppress the chemotaxis of T-cells and monocytes, implicating the role of TRPV4 in maintaining the immune privilege of healthy IVD.
Collapse
Affiliation(s)
- Garrett W. D. Easson
- Department of Orthopaedic SurgeryWashington University in St. LouisSt. LouisMissouriUSA
- Department of Mechanical Engineering and Materials ScienceWashington University in St. LouisSt. LouisMissouriUSA
| | - Alireza Savadipour
- Department of Orthopaedic SurgeryWashington University in St. LouisSt. LouisMissouriUSA
- Department of Mechanical Engineering and Materials ScienceWashington University in St. LouisSt. LouisMissouriUSA
- Shriners Hospitals for Children—St. LouisSt. LouisMissouriUSA
| | - Christian Gonzalez
- Department of Biomedical EngineeringWashington University in St. LouisSt. LouisMissouriUSA
| | - Farshid Guilak
- Department of Orthopaedic SurgeryWashington University in St. LouisSt. LouisMissouriUSA
- Department of Mechanical Engineering and Materials ScienceWashington University in St. LouisSt. LouisMissouriUSA
- Shriners Hospitals for Children—St. LouisSt. LouisMissouriUSA
- Department of Biomedical EngineeringWashington University in St. LouisSt. LouisMissouriUSA
| | - Simon Y. Tang
- Department of Orthopaedic SurgeryWashington University in St. LouisSt. LouisMissouriUSA
- Department of Mechanical Engineering and Materials ScienceWashington University in St. LouisSt. LouisMissouriUSA
- Department of Biomedical EngineeringWashington University in St. LouisSt. LouisMissouriUSA
| |
Collapse
|
2
|
Easson GWD, Savadipour A, Anandarajah A, Iannucci LE, Lake SP, Guilak F, Tang SY. Modulation of TRPV4 protects against degeneration induced by sustained loading and promotes matrix synthesis in the intervertebral disc. FASEB J 2023; 37:e22714. [PMID: 36583692 DOI: 10.1096/fj.202201388r] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 11/15/2022] [Accepted: 12/05/2022] [Indexed: 12/31/2022]
Abstract
While it is well known that mechanical signals can either promote or disrupt intervertebral disc (IVD) homeostasis, the molecular mechanisms for transducing mechanical stimuli are not fully understood. The transient receptor potential vanilloid 4 (TRPV4) ion channel activated in isolated IVD cells initiates extracellular matrix (ECM) gene expression, while TRPV4 ablation reduces cytokine production in response to circumferential stretching. However, the role of TRPV4 on ECM maintenance during tissue-level mechanical loading remains unknown. Using an organ culture model, we modulated TRPV4 function over both short- (hours) and long-term (days) and evaluated the IVDs' response. Activating TRPV4 with the agonist GSK101 resulted in a Ca2+ flux propagating across the cells within the IVD. Nuclear factor (NF)-κB signaling in the IVD peaked at 6 h following TRPV4 activation that subsequently resulted in higher interleukin (IL)-6 production at 7 days. These cellular responses were concomitant with the accumulation of glycosaminoglycans and increased hydration in the nucleus pulposus that culminated in higher stiffness of the IVD. Sustained compressive loading of the IVD resulted in elevated NF-κB activity, IL-6 and vascular endothelial growth factor A (VEGFA) production, and degenerative changes to the ECM. TRPV4 inhibition using GSK205 during loading mitigated the changes in inflammatory cytokines, protected against IVD degeneration, but could not prevent ECM disorganization due to mechanical damage in the annulus fibrosus. These results indicate TRPV4 plays an important role in both short- and long-term adaptations of the IVD to mechanical loading. The modulation of TRPV4 may be a possible therapeutic for preventing load-induced IVD degeneration.
Collapse
Affiliation(s)
- Garrett W D Easson
- Department of Mechanical Engineering, Washington University in St. Louis, St. Louis, Missouri, USA.,Department of Orthopaedic Surgery, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Alireza Savadipour
- Department of Mechanical Engineering, Washington University in St. Louis, St. Louis, Missouri, USA.,Department of Orthopaedic Surgery, Washington University in St. Louis, St. Louis, Missouri, USA.,Shriner's Hospital for Children - St. Louis, St. Louis, Missouri, USA
| | - Akila Anandarajah
- Department of Orthopaedic Surgery, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Leanne E Iannucci
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Spencer P Lake
- Department of Mechanical Engineering, Washington University in St. Louis, St. Louis, Missouri, USA.,Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Farshid Guilak
- Department of Mechanical Engineering, Washington University in St. Louis, St. Louis, Missouri, USA.,Department of Orthopaedic Surgery, Washington University in St. Louis, St. Louis, Missouri, USA.,Shriner's Hospital for Children - St. Louis, St. Louis, Missouri, USA.,Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Simon Y Tang
- Department of Mechanical Engineering, Washington University in St. Louis, St. Louis, Missouri, USA.,Department of Orthopaedic Surgery, Washington University in St. Louis, St. Louis, Missouri, USA.,Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri, USA
| |
Collapse
|
3
|
Yoon DHE, Weber CI, Easson GWD, Broz KS, Tang SY. Rapid determination of internal strains in soft tissues using an experimentally calibrated finite element model derived from magnetic resonance imaging. Quant Imaging Med Surg 2020; 10:57-65. [DOI: 10.21037/qims.2019.10.16] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
4
|
Liu Z, Easson GWD, Zhao J, Makki N, Ahituv N, Hilton MJ, Tang SY, Gray RS. Dysregulation of STAT3 signaling is associated with endplate-oriented herniations of the intervertebral disc in Adgrg6 mutant mice. PLoS Genet 2019; 15:e1008096. [PMID: 31652254 PMCID: PMC6834287 DOI: 10.1371/journal.pgen.1008096] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 11/06/2019] [Accepted: 09/18/2019] [Indexed: 12/01/2022] Open
Abstract
Degenerative changes of the intervertebral disc (IVD) are a leading cause of disability affecting humans worldwide and has been attributed primarily to trauma and the accumulation of pathology during aging. While genetic defects have also been associated with disc degeneration, the precise mechanisms driving the initiation and progression of disease have remained elusive due to a paucity of genetic animal models. Here, we discuss a novel conditional mouse genetic model of endplate-oriented disc herniations in adult mice. Using conditional mouse genetics, we show increased mechanical stiffness and reveal dysregulation of typical gene expression profiles of the IVD in adhesion G-protein coupled receptor G6 (Adgrg6) mutant mice prior to the onset of endplate-oriented disc herniations in adult mice. We observed increased STAT3 activation prior to IVD defects and go on to demonstrate that treatment of Adgrg6 conditional mutant mice with a small molecule inhibitor of STAT3 activation ameliorates endplate-oriented herniations. These findings establish ADGRG6 and STAT3 as novel regulators of IVD endplate and growth plate integrity in the mouse, and implicate ADGRG6/STAT3 signaling as promising therapeutic targets for endplate-oriented disc degeneration. Back pain is a leading cause of disability in humans worldwide and one of the most common culprits of these issues are the consequence of degenerative changes of the intervertebral disc. Here, we demonstrate that conditional loss of the Adgrg6 gene in cartilaginous tissues of the spine results in endplate-oriented disc herniations and degenerative changes of the intervertebral disc in mice. We further establish that these obvious degenerative changes of the disc are preceded by substantial alterations in normal gene expression profiles, including upregulation of pro-inflammatory STAT3 signaling, and increased mechanical stiffness of the intervertebral disc. Increased STAT3 activation is a signal observed in other models of degenerative musculoskeletal tissues. As such, we tested whether systemic treatment with a small-molecule STAT3 inhibitor would protect against the formation of endplate-oriented disc herniations in conditional Adgrg6 mutant mice, and report a significant positive improvement of histopathology in our treatment group. Taken together, we demonstrate a novel conditional model of endplate-oriented disc herniation in mouse. We establish ADGRG6 and STAT3 as novel regulators of endplate integrity of the intervertebral disc in mouse and suggest that modulation of ADGRG6/STAT3 signaling could provide robust disease-modifying targets for endplate-oriented disc degeneration in humans.
Collapse
Affiliation(s)
- Zhaoyang Liu
- Department of Nutritional Sciences, University of Texas at Austin, Austin, Texas, United States of America
- Department of Pediatrics, Dell Pediatric Research Institute, University of Texas at Austin Dell Medical School, Austin, Texas, United States of America
| | - Garrett W. D. Easson
- Department of Orthopedics, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - Jingjing Zhao
- Department of Bioengineering and Therapeutic Sciences and Institute for Human Genetics, University of California San Francisco, San Francisco, California, United States of America
| | - Nadja Makki
- Department of Bioengineering and Therapeutic Sciences and Institute for Human Genetics, University of California San Francisco, San Francisco, California, United States of America
- Department of Anatomy and Cell Biology, University of Florida, College of Medicine, Gainesville, Florida, United States of America
| | - Nadav Ahituv
- Department of Bioengineering and Therapeutic Sciences and Institute for Human Genetics, University of California San Francisco, San Francisco, California, United States of America
| | - Matthew J. Hilton
- Department of Orthopedic Surgery and Cell Biology, Duke University School of Medicine, Durham, North Carolina, United States of America
| | - Simon Y. Tang
- Department of Orthopedics, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - Ryan S. Gray
- Department of Nutritional Sciences, University of Texas at Austin, Austin, Texas, United States of America
- Department of Pediatrics, Dell Pediatric Research Institute, University of Texas at Austin Dell Medical School, Austin, Texas, United States of America
- * E-mail:
| |
Collapse
|