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Singh S, Winkelstein BA. Characterization of the L4/L5 rat facet capsular ligament macromechanical and microstructural responses to tensile failure loading. J Biomech 2023; 157:111742. [PMID: 37523884 PMCID: PMC10475220 DOI: 10.1016/j.jbiomech.2023.111742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 07/22/2023] [Accepted: 07/26/2023] [Indexed: 08/02/2023]
Abstract
Low back pain is a prevalent condition that affects the global population. The lumbar facet capsular ligament is a source of pain since the collagenous tissue of the ligament is innervated with sensory neurons that deform with the capsule's stretch. Regional differences in the microstructural and macrostructural anatomy of the spinal facets affect its capsule's mechanical behavior. Although there are many studies of the cervical facet in human and rodent models, the lumbar capsular ligament's multiscale behavior is less well-defined. This study characterizes the macroscale and fiber-scale changes of the rat lumbar facet capsule during tensile failure loading. An integrated polarized light imaging setup captured local fiber alignment during 0.08 mm/s distraction of 7 lumbar facets. Force, displacement, strain, and circular variance were measured at several points along the failure curve: the first instance when the local collagen fiber network realigns differentially (anomalous realignment), yield, the first peak in force corresponding to the capsule's first failure, and peak force, defined as ultimate rupture. Those outcomes were compared across events. While each of force, displacement, and average maximum principal strain increased with applied tension, so did the circular variance of the collagen, suggesting that the fibers were becoming more disorganized. From the fiber alignment maps collected at each mechanical event, the number of anomalous realignment events were counted and found to increase dramatically with loading. The increased collagen disorganization and increasing regions of such disorganization in the facet capsule during loading can provide insights about how loading to the ligament afferent nerves may be activated and thereby produce pain.
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Affiliation(s)
- Sagar Singh
- Department of Bioengineering, University of Pennsylvania, 210 S 33rd St., Philadelphia, PA 19104, United States
| | - Beth A Winkelstein
- Department of Bioengineering, University of Pennsylvania, 210 S 33rd St., Philadelphia, PA 19104, United States; Department of Neurosurgery, University of Pennsylvania, 3400 Spruce St., Philadelphia, PA 19104, United States.
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Fine N, Lively S, Séguin CA, Perruccio AV, Kapoor M, Rampersaud R. Intervertebral disc degeneration and osteoarthritis: a common molecular disease spectrum. Nat Rev Rheumatol 2023; 19:136-152. [PMID: 36702892 DOI: 10.1038/s41584-022-00888-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/05/2022] [Indexed: 01/27/2023]
Abstract
Intervertebral disc degeneration (IDD) and osteoarthritis (OA) affecting the facet joint of the spine are biomechanically interdependent, typically occur in tandem, and have considerable epidemiological and pathophysiological overlap. Historically, the distinctions between these degenerative diseases have been emphasized. Therefore, research in the two fields often occurs independently without adequate consideration of the co-dependence of the two sites, which reside within the same functional spinal unit. Emerging evidence from animal models of spine degeneration highlight the interdependence of IDD and facet joint OA, warranting a review of the parallels between these two degenerative phenomena for the benefit of both clinicians and research scientists. This Review discusses the pathophysiological aspects of IDD and OA, with an emphasis on tissue, cellular and molecular pathways of degeneration. Although the intervertebral disc and synovial facet joint are biologically distinct structures that are amenable to reductive scientific consideration, substantial overlap exists between the molecular pathways and processes of degeneration (including cartilage destruction, extracellular matrix degeneration and osteophyte formation) that occur at these sites. Thus, researchers, clinicians, advocates and policy-makers should consider viewing the burden and management of spinal degeneration holistically as part of the OA disease continuum.
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Affiliation(s)
- Noah Fine
- Osteoarthritis Research Program, Division of Orthopaedics, Schroeder Arthritis Institute, University Health Network, Toronto, Ontario, Canada.,Krembil Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Starlee Lively
- Osteoarthritis Research Program, Division of Orthopaedics, Schroeder Arthritis Institute, University Health Network, Toronto, Ontario, Canada.,Krembil Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Cheryle Ann Séguin
- Department of Physiology & Pharmacology, Schulich School of Medicine & Dentistry, Bone and Joint Institute, University of Western Ontario London, London, Ontario, Canada
| | - Anthony V Perruccio
- Osteoarthritis Research Program, Division of Orthopaedics, Schroeder Arthritis Institute, University Health Network, Toronto, Ontario, Canada.,Krembil Research Institute, University Health Network, Toronto, Ontario, Canada.,Institute of Health Policy, Management and Evaluation, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.,Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Mohit Kapoor
- Osteoarthritis Research Program, Division of Orthopaedics, Schroeder Arthritis Institute, University Health Network, Toronto, Ontario, Canada.,Krembil Research Institute, University Health Network, Toronto, Ontario, Canada.,Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Raja Rampersaud
- Osteoarthritis Research Program, Division of Orthopaedics, Schroeder Arthritis Institute, University Health Network, Toronto, Ontario, Canada. .,Krembil Research Institute, University Health Network, Toronto, Ontario, Canada. .,Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
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Piri R, Nøddeskou‐Fink AH, Gerke O, Larsson M, Edenbrandt L, Enqvist O, Høilund‐Carlsen P, Stochkendahl MJ. PET/CT imaging of spinal inflammation and microcalcification in patients with low back pain: A pilot study on the quantification by artificial intelligence-based segmentation. Clin Physiol Funct Imaging 2022; 42:225-232. [PMID: 35319166 PMCID: PMC9322590 DOI: 10.1111/cpf.12751] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 03/11/2022] [Indexed: 12/29/2022]
Abstract
BACKGROUND Current imaging modalities are often incapable of identifying nociceptive sources of low back pain (LBP). We aimed to characterize these by means of positron emission tomography/computed tomography (PET/CT) of the lumbar spine region applying tracers 18 F-fluorodeoxyglucose (FDG) and 18 F-sodium fluoride (NaF) targeting inflammation and active microcalcification, respectively. METHODS Using artificial intelligence (AI)-based quantification, we compared PET findings in two sex- and age-matched groups, a case group of seven males and five females, mean age 45 ± 14 years, with ongoing LBP and a similar control group of 12 pain-free individuals. PET/CT scans were segmented into three distinct volumes of interest (VOIs): lumbar vertebral bodies, facet joints and intervertebral discs. Maximum, mean and total standardized uptake values (SUVmax, SUVmean and SUVtotal) for FDG and NaF uptake in the 3 VOIs were measured and compared between groups. Holm-Bonferroni correction was applied to adjust for multiple testing. RESULTS FDG uptake was slightly higher in most locations of the LBP group including higher SUVmean in the intervertebral discs (0.96 ± 0.34 vs. 0.69 ± 0.15). All NaF uptake values were higher in cases, including higher SUVmax in the intervertebral discs (11.63 ± 3.29 vs. 9.45 ± 1.32) and facet joints (14.98 ± 6.55 vs. 10.60 ± 2.97). CONCLUSION Observed intergroup differences suggest acute inflammation and microcalcification as possible nociceptive causes of LBP. AI-based quantification of relevant lumbar VOIs in PET/CT scans of LBP patients and controls appears to be feasible. These promising, early findings warrant further investigation and confirmation.
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Affiliation(s)
- Reza Piri
- Department of Nuclear MedicineOdense University HospitalOdenseDenmark
- Department of Clinical ResearchUniversity of Southern DenmarkOdenseDenmark
| | | | - Oke Gerke
- Department of Nuclear MedicineOdense University HospitalOdenseDenmark
- Department of Clinical ResearchUniversity of Southern DenmarkOdenseDenmark
| | | | - Lars Edenbrandt
- Department of Molecular and Clinical Medicine, Sahlgrenska AcademyUniversity of GothenburgGothenburgSweden
- Department of Clinical PhysiologyRegion Västra Götaland, Sahlgrenska University HospitalGothenburgSweden
| | - Olof Enqvist
- Eigenvision ABMalmöSweden
- Department of Electrical EngineeringChalmers University of TechnologyGothenburgSweden
| | - Poul‐Flemming Høilund‐Carlsen
- Department of Nuclear MedicineOdense University HospitalOdenseDenmark
- Department of Clinical ResearchUniversity of Southern DenmarkOdenseDenmark
| | - Mette J. Stochkendahl
- Department of Sports Science and Clinical BiomechanicsUniversity of Southern DenmarkOdenseDenmark
- Chiropractic Knowledge HubOdenseDenmark
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Activity of genes of matrix metalloproteinases and their inhibitors in the Ligamentum flavum of patients with stenosing processes in spinal canal and dural sac. ACTA BIOMEDICA SCIENTIFICA 2021. [DOI: 10.29413/abs.2021-6.6-2.7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
New data have been obtained for assessing the expression of genes of metalloproteinases and their tissue inhibitors (MMP-1, MMP-2, MMP-3, MMP-8, MMP-9, TIMP-1 and TIMP-2) in the Ligamentum flavum in patients with lumbar stenosis of spinal canal and dural sac. The features of the metabolism of the extracellular matrix (ECM) were revealed, the data obtained were compared with those for previously studied candidate genes. The search for relationships with the features of the ECM metabolic characteristics was carried out.The aim. To study the expression of genes of metalloproteinases and their tissue inhibitors in intraoperative biopsies of the Ligamentum flavum of patients with lumbar stenosis of the spinal canal and dural sac.Materials and methods. A group of 33 people (17 women, 16 men) with lumbar stenosis of the spinal canal and dural sac was studied; the average age is 45.73 ± 1.95 years. RNA was isolated from intraoperative biopsies of the Ligamentum flavum, reverse transcription was performed, and PCR using specific primers was performed.Results. In Ligamentum flavum of patients with stenosing processes of the spinal canal and dural sac, an increased activity of MMP-1 and insufficient response of TIMP-1 and TIMP-2 were found; the expression of MMP-1 increased synchronously with Dio2, and both genes decreased their activity with increasing age of the patient. In patients with Ligamentum flavum ossification, the MMR-8 gene was more actively expressed, and the synthesis of the mRNA of the MMR-9 gene decreased compared to the subgroup without ossification.
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Sugimoto K, Nakamura T, Tokunaga T, Uehara Y, Okada T, Taniwaki T, Fujimoto T, Oike Y, Nakamura E. Angiopoietin-Like Protein 2 Induces Synovial Inflammation in the Facet Joint Leading to Degenerative Changes via Interleukin-6 Secretion. Asian Spine J 2019; 13:368-376. [PMID: 30685956 PMCID: PMC6547404 DOI: 10.31616/asj.2018.0178] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 09/11/2018] [Indexed: 11/23/2022] Open
Abstract
Study Design Experimental human study. Purpose To determine whether angiopoietin-like protein 2 (ANGPTL2) is highly expressed in the hyperplastic facet joint (FJ) synovium and whether it activates interleukin-6 (IL-6) secretion in FJ synoviocytes. Overview of Literature Mechanical stress-induced synovitis is partially, but significantly, responsible for degenerative and subsequently osteoarthritic changes in the FJ tissues in patients with lumbar spinal stenosis (LSS). However, the underlying molecular mechanism remains unclear. IL-6 is highly expressed in degenerative FJ synovial tissue and is responsible for local chronic inflammation. ANGPTL2, an inflammatory and mechanically induced mediator, promotes the expression of IL-6 in many cells. Methods FJ tissues were harvested from five patients who had undergone lumbar surgery. Immunohistochemistry for ANGPTL2, IL-6, and cell markers was performed in the FJ tissue samples. After cultured synoviocytes from the FJ tissues were subjected to mechanical stress, ANGPTL2 expression and secretion were measured quantitatively using real-time quantitative reverse-transcription–polymerase chain reaction and enzyme-linked immunosorbent assay (ELISA), respectively. Following ANGPTL2 administration in the FJ synoviocytes, anti-nuclear factor-κB (NF-κB) activation was investigated using immunocytochemistry, and IL-6 expression and secretion were assayed quantitatively with or without NF-κB inhibitor. Moreover, we assessed whether ANGPTL2-induced IL-6 modulates leucocyte recruitment in the degenerative process by focusing on the monocyte chemoattractant protein-1 (MCP-1) expression. Results ANGPTL2 and IL-6 were highly expressed in the hyperplastic FJ synovium samples. ANGPTL2 was co-expressed in both, fibroblast-like and macrophage-like synoviocytes. Further, the expression and secretion of ANGPTL2 in the FJ synoviocytes increased in response to stimulation by mechanical stretching. ANGPTL2 protein promoted the nuclear translocation of NF-κB and induced IL-6 expression and secretion in the FJ synoviocytes. This effect was reversed following treatment with NF-κB inhibitor. Furthermore, ANGPTL2-induced IL-6 upregulated the MCP-1 expression in the FJ synoviocytes. Conclusions Mechanical stress-induced ANGPTL2 promotes chronic inflammation in the FJ synovium by activating IL-6 secretion, leading to FJ degeneration and subsequent LSS.
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Affiliation(s)
- Kazuki Sugimoto
- Department of Orthopaedics, Graduate School of Medical Science, Kumamoto University, Kumamoto, Japan
| | - Takayuki Nakamura
- Department of Orthopaedics, Graduate School of Medical Science, Kumamoto University, Kumamoto, Japan
| | - Takuya Tokunaga
- Department of Orthopaedics, Graduate School of Medical Science, Kumamoto University, Kumamoto, Japan
| | - Yusuke Uehara
- Department of Orthopaedics, Graduate School of Medical Science, Kumamoto University, Kumamoto, Japan
| | - Tatsuya Okada
- Department of Orthopaedics, Graduate School of Medical Science, Kumamoto University, Kumamoto, Japan
| | - Takuya Taniwaki
- Department of Orthopaedics, Graduate School of Medical Science, Kumamoto University, Kumamoto, Japan
| | - Toru Fujimoto
- Department of Orthopaedics, Graduate School of Medical Science, Kumamoto University, Kumamoto, Japan
| | - Yuichi Oike
- Department of Molecular Genetics, Graduate School of Medical Science, Kumamoto University, Kumamoto, Japan
| | - Eiichi Nakamura
- Department of Orthopaedics, Graduate School of Medical Science, Kumamoto University, Kumamoto, Japan
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Xiao L, Xu S, Wang X, Jin Z, Wang J, Yang B, Xu H. Isolation and characterization of stem cells from differentially degenerated human lumbar zygapophyseal articular cartilage. Mol Med Rep 2018; 18:5751-5759. [PMID: 30365096 DOI: 10.3892/mmr.2018.9592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 09/28/2018] [Indexed: 11/06/2022] Open
Abstract
The present study aimed to verify the presence of stem cells with multilineage differentiation potential in human lumbar zygapophyseal articular cartilage (LZAC) and to compare the chondrogenic potential of cells obtained from differentially degenerated articular cartilage samples. Surgically obtained human lumbar zygapophyseal joint tissues were classified into the normal, mildly degenerated and severely degenerated groups, according to their pathological characteristics. Primary chondrocytes from these groups were cultured, and stem cells were selected using a monoclonal cell culture method. Differences in stem cell morphology between the three groups were observed using inverted microscopy and phalloidin staining. In addition, stem cell chondrogenic potential was determined through induced differentiation and cellular staining. Gene and protein expression levels of the chondrogenic‑specific markers aggrecan, collagen type‑II and SRY‑related high‑mobility‑group box 9 were determined using reverse transcription‑quantitative polymerase chain reaction and western blotting. The clonogenic ability of stem cells in the three groups was determined using a clonogenic assay. It was revealed that stem cells with multilineage differentiation potential were isolated from all three cartilage groups; however, the cells obtained from severely degenerated articular cartilage resulted in severe fibrosis, whilst those obtained from mildly degenerated articular cartilage possessed stronger chondrogenic and clonogenic abilities. Taken together, stem cells with multilineage differentiation potential and clonal properties were identified in human LZAC, and these characteristics were more prominent in mildly degenerated as compared with severely degenerated articular cartilage.
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Affiliation(s)
- Liang Xiao
- Department of Orthopedic Surgery, Yijishan Hospital, The First Affiliated Hospital of Wannan Medical College, Wuhu, Anhui 241001, P.R. China
| | - Shujuan Xu
- Department of Surgery, Yijishan Hospital, The First Affiliated Hospital of Wannan Medical College, Wuhu, Anhui 241001, P.R. China
| | - Xiao Wang
- Department of Orthopedic Surgery, Yijishan Hospital, The First Affiliated Hospital of Wannan Medical College, Wuhu, Anhui 241001, P.R. China
| | - Zhongxing Jin
- Department of Orthopedic Surgery, Yijishan Hospital, The First Affiliated Hospital of Wannan Medical College, Wuhu, Anhui 241001, P.R. China
| | - Jing Wang
- Department of Orthopedic Surgery, Yijishan Hospital, The First Affiliated Hospital of Wannan Medical College, Wuhu, Anhui 241001, P.R. China
| | - Bijing Yang
- Department of Orthopedic Surgery, Yijishan Hospital, The First Affiliated Hospital of Wannan Medical College, Wuhu, Anhui 241001, P.R. China
| | - Hongguang Xu
- Department of Orthopedic Surgery, Yijishan Hospital, The First Affiliated Hospital of Wannan Medical College, Wuhu, Anhui 241001, P.R. China
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Osteogenic differentiation of preosteoblasts on a hemostatic gelatin sponge. Sci Rep 2016; 6:32884. [PMID: 27616161 PMCID: PMC5018723 DOI: 10.1038/srep32884] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 08/16/2016] [Indexed: 02/07/2023] Open
Abstract
Bone tissue engineering provides many advantages for repairing skeletal defects. Although many different kinds of biomaterials have been used for bone tissue engineering, safety issues must be considered when using them in a clinical setting. In this study, we examined the effects of using a common clinical item, a hemostatic gelatin sponge, as a scaffold for bone tissue engineering. The use of such a clinically acceptable item may hasten the translational lag from laboratory to clinical studies. We performed both degradation and biocompatibility studies on the hemostatic gelatin sponge, and cultured preosteoblasts within the sponge scaffold to demonstrate its osteogenic differentiation potential. In degradation assays, the gelatin sponge demonstrated good stability after being immersed in PBS for 8 weeks (losing only about 10% of its net weight and about 54% decrease of mechanical strength), but pepsin and collagenases readily biodegraded it. The gelatin sponge demonstrated good biocompatibility to preosteoblasts as demonstrated by MTT assay, confocal microscopy, and scanning electron microscopy. Furthermore, osteogenic differentiation and the migration of preosteoblasts, elevated alkaline phosphatase activity, and in vitro mineralization were observed within the scaffold structure. Each of these results indicates that the hemostatic gelatin sponge is a suitable scaffold for bone tissue engineering.
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Rempe RG, Hartz AMS, Bauer B. Matrix metalloproteinases in the brain and blood-brain barrier: Versatile breakers and makers. J Cereb Blood Flow Metab 2016; 36:1481-507. [PMID: 27323783 PMCID: PMC5012524 DOI: 10.1177/0271678x16655551] [Citation(s) in RCA: 417] [Impact Index Per Article: 52.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 05/26/2016] [Indexed: 02/01/2023]
Abstract
Matrix metalloproteinases are versatile endopeptidases with many different functions in the body in health and disease. In the brain, matrix metalloproteinases are critical for tissue formation, neuronal network remodeling, and blood-brain barrier integrity. Many reviews have been published on matrix metalloproteinases before, most of which focus on the two best studied matrix metalloproteinases, the gelatinases MMP-2 and MMP-9, and their role in one or two diseases. In this review, we provide a broad overview of the role various matrix metalloproteinases play in brain disorders. We summarize and review current knowledge and understanding of matrix metalloproteinases in the brain and at the blood-brain barrier in neuroinflammation, multiple sclerosis, cerebral aneurysms, stroke, epilepsy, Alzheimer's disease, Parkinson's disease, and brain cancer. We discuss the detrimental effects matrix metalloproteinases can have in these conditions, contributing to blood-brain barrier leakage, neuroinflammation, neurotoxicity, demyelination, tumor angiogenesis, and cancer metastasis. We also discuss the beneficial role matrix metalloproteinases can play in neuroprotection and anti-inflammation. Finally, we address matrix metalloproteinases as potential therapeutic targets. Together, in this comprehensive review, we summarize current understanding and knowledge of matrix metalloproteinases in the brain and at the blood-brain barrier in brain disorders.
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Affiliation(s)
- Ralf G Rempe
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY, USA
| | - Anika M S Hartz
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA Department of Pharmacology and Nutritional Sciences, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - Björn Bauer
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY, USA
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Vardeh D, Mannion RJ, Woolf CJ. Toward a Mechanism-Based Approach to Pain Diagnosis. THE JOURNAL OF PAIN 2016; 17:T50-69. [PMID: 27586831 PMCID: PMC5012312 DOI: 10.1016/j.jpain.2016.03.001] [Citation(s) in RCA: 193] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 02/22/2016] [Accepted: 03/08/2016] [Indexed: 12/13/2022]
Abstract
UNLABELLED The past few decades have witnessed a huge leap forward in our understanding of the mechanistic underpinnings of pain, in normal states where it helps protect from injury, and also in pathological states where pain evolves from a symptom reflecting tissue injury to become the disease itself. However, despite these scientific advances, chronic pain remains extremely challenging to manage clinically. Although the number of potential treatment targets has grown substantially and a strong case has been made for a mechanism-based and individualized approach to pain therapy, arguably clinicians are not much more advanced now than 20 years ago, in their capacity to either diagnose or effectively treat their patients. The gulf between pain research and pain management is as wide as ever. We are still currently unable to apply an evidence-based approach to chronic pain management that reflects mechanistic understanding, and instead, clinical practice remains an empirical and often unsatisfactory journey for patients, whose individual response to treatment cannot be predicted. In this article we take a common and difficult to treat pain condition, chronic low back pain, and use its presentation in clinical practice as a framework to highlight what is known about pathophysiological pain mechanisms and how we could potentially detect these to drive rational treatment choice. We discuss how present methods of assessment and management still fall well short, however, of any mechanism-based or precision medicine approach. Nevertheless, substantial improvements in chronic pain management could be possible if a more strategic and coordinated approach were to evolve, one designed to identify the specific mechanisms driving the presenting pain phenotype. We present an analysis of such an approach, highlighting the major problems in identifying mechanisms in patients, and develop a framework for a pain diagnostic ladder that may prove useful in the future, consisting of successive identification of 3 steps: pain state, pain mechanism, and molecular target. Such an approach could serve as the foundation for a new era of individualized/precision pain medicine. The Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION)-American Pain Society (APS) Pain Taxonomy (AAPT) includes pain mechanisms as 1 of the 5 dimensions that need to be considered when making a diagnostic classification. The diagnostic ladder proposed in this article is consistent with and an extension of the AAPT. PERSPECTIVE We discuss how identifying the specific mechanisms that operate in the nervous system to produce chronic pain in individual patients could provide the basis for a targeted and rational precision medicine approach to controlling pain, using chronic low back pain as our example.
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Affiliation(s)
- Daniel Vardeh
- Division of Pain Neurology, Department of Neurology and Anesthesia, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts
| | - Richard J Mannion
- Department of Academic Neurosurgery, Cambridge University Hospitals NHS Trust, Cambridge, United Kingdom
| | - Clifford J Woolf
- FM Kirby Neurobiology Center, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts.
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Liu XG, Hou HW, Liu YL. Expression levels of IL-17 and TNF-α in degenerated lumbar intervertebral discs and their correlation. Exp Ther Med 2016; 11:2333-2340. [PMID: 27284317 DOI: 10.3892/etm.2016.3250] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 12/03/2015] [Indexed: 01/03/2023] Open
Abstract
The present study aimed to investigate the expression and roles of interleukin (IL)-17 and tumor necrosis factor (TNF)-α in intervertebral disc degeneration (IDD) and to identify the association between the effects of IL-17 and TNF-α in IDD. This may increase understanding of the pathogenic mechanism underlying IDD, and aid the development of alternative therapies. The experimental group consisted of 40 samples of nucleus pulposus tissue obtained from the intervertebral discs (IVDs) of patients with IDD by surgical intervention, and was further divided into an annulus fibrosus disrupted group, comprising 18 patients in which the external annulus was ruptured, and an annulus fibrosus intact group comprising 22 patients. The control group consisted of 20 samples of nucleus pulposus tissue from the IVDs of patients with traumatic lumbar disc fractures. The mRNA and protein expression levels of IL-17 and TNF-α in the 50 tissue samples were detected by semi-quantitative reverse transcription polymerase chain reaction and immunohistochemical staining, respectively, and the results were statistically analyzed. The IL-17 and TNF-α protein and mRNA expression levels in the annulus fibrosus disrupted and annulus fibrosus intact groups were both higher compared with those in the control group. In addition, the expression levels of IL-17 and TNF-α in the annulus fibrosus disrupted group were significantly higher compared with those in the annulus fibrosus intact group (P<0.01). A positive correlation was identified between the mRNA and protein expression levels of IL-17 and TNF-α in the experimental group (r=0.957, P<0.01). IL-17 and TNF-α may therefore be involved in the progression of human IDD, and may have synergistic effects in the development of IDD.
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Affiliation(s)
- Xiao-Gang Liu
- Department of Orthopedics, Weihai Hospital of Qingdao University, Weihai, Shandong 264200, P.R. China
| | - Hong-Wei Hou
- Department of Information, Weihai Hospital of Qingdao University, Weihai, Shandong 264200, P.R. China
| | - Yi-Lin Liu
- Department of Internal Medicine, Worker's Hospital of Xinjiang Dushanzi Mining Area Services Division, Karamay, Xinjiang 833699, P.R. China
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Davelaar AL, Straub D, Buttar NS, Fockens P, Krishnadath KK. Active matrix metalloproteases are expressed early on and are high during the Barrett's esophagus malignancy sequence. Scand J Gastroenterol 2015; 50:321-32. [PMID: 25562781 DOI: 10.3109/00365521.2014.940379] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Molecular processes underlying Barrett's malignant development are poorly understood. Matrix metalloproteases (MMPs) are enzymes involved in inflammation, tissue remodeling, and malignant development. Therefore, active MMPs may have a role in early metaplasia development and Barrett's esophagus' malignant progression. We desired to gain more insight into the role of MMPs during the Barrett's esophagus pathogenesis sequence. MATERIAL AND METHODS In a surgical Barrett's mouse model, and in nonmalignant Barrett's and malignant esophageal cell lines, the activity of MMPs was investigated using a MMP activatable probe. MMP activity was further validated in Barrett's esophagus and esophageal adenocarcinoma patient biopsies and was further differentiated by investigating MMP9 and MMP13 expressions. RESULTS The mouse model showed probe activation in stromal cells early on in the esophagitis and metaplasia stages. MMP probe activation was higher in the Barrett's and cancer cell lines and biopsies as compared to normal cells and tissues. Co-immunostainings confirmed that, at the tissue level, the probe activation was mostly confined to CD45-positive stromal cells. MMP13 expression was highest in Barrett's metaplasia, whereas MMP9 was highest in the esophageal adenocarcinomas. CONCLUSION During the Barrett's pathogenesis process, MMP activity is increased early on in the inflamed esophagus and remains high in metaplasia and esophageal adenocarcinoma. However, there is a switch of MMP13 to MMP9 expression once neoplasia develops. In the future, detecting specific MMP subtypes could be used for distinguishing nonmalignant from neoplastic Barrett's esophagus.
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Affiliation(s)
- Akueni L Davelaar
- Department of Gastroenterology and Hepatology, Academic Medical Center , Amsterdam , The Netherlands
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