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Lin H, Tian S, Peng Y, Wu L, Xiao Y, Qing X, Shao Z. IGF Signaling in Intervertebral Disc Health and Disease. Front Cell Dev Biol 2022; 9:817099. [PMID: 35178405 PMCID: PMC8843937 DOI: 10.3389/fcell.2021.817099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 12/27/2021] [Indexed: 11/18/2022] Open
Abstract
Low back pain (LBP) is a common musculoskeletal symptom, which brings a lot of pain and economic loss to patients. One of the most common causes of LBP is intervertebral disc degeneration (IVDD). However, pathogenesis is still debated, and therapeutic options are limited. Insulin-like growth factor (IGF) signaling pathways play an important role in regulating different cell processes, including proliferation, differentiation, migration, or cell death, which are critical to the homeostasis of tissues and organs. The IGF signaling is crucial in the occurrence and progression of IVDD. The activation of IGF signaling retards IVDD by increasing cell proliferation, promoting extracellular matrix (ECM) synthesis, inhibiting ECM decomposition, and preventing apoptosis and senescence of disc cells. However, abnormal activation of IGF signaling may promote the process of IVDD. IGF signaling is currently considered to have a promising treatment prospect for IVDD. An in-depth understanding of the role of IGF signaling in IVDD may help find a novel approach for IVDD treatment.
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Affiliation(s)
- Hui Lin
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Shuo Tian
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yizhong Peng
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ling Wu
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yan Xiao
- Department of Radiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiangcheng Qing
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zengwu Shao
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Wu CC, Yang SH, Huang TL, Liu CC, Lu DH, Yang KC, Lin FH. The interaction between co-cultured human nucleus pulposus cells and mesenchymal stem cells in a bioactive scaffold. Process Biochem 2012. [DOI: 10.1016/j.procbio.2012.02.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Pratsinis H, Constantinou V, Pavlakis K, Sapkas G, Kletsas D. Exogenous and autocrine growth factors stimulate human intervertebral disc cell proliferation via the ERK and Akt pathways. J Orthop Res 2012; 30:958-64. [PMID: 22105580 DOI: 10.1002/jor.22017] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Accepted: 10/31/2011] [Indexed: 02/04/2023]
Abstract
Intervertebral disc (IVD) degeneration is accompanied by growth factor-overexpression and increased cell proliferation, probably representing a tissue repair process. Accordingly, we studied the effect of exogenous and autocrine growth factors on the proliferation of human IVD cells. We observed that Platelet-Derived Growth Factor (PDGF), basic Fibroblast Growth Factor (bFGF), and Insulin-like Growth Factor-I (IGF-I) stimulate DNA synthesis of human IVD cells, through the activation of the MEK/ERK and the PI-3K/Akt signal transduction pathways. Furthermore, medium conditioned (CM) by IVD cells induced DNA synthesis in the same cells, indicating the secretion of autocrine growth factors. The MEK/ERK and PI-3K/Akt pathways were also induced by CM, while their inhibition reversed in large part the DNA synthesis induction by CM. These responses to the exogenous and autocrine growth factors were qualitatively similar in both nucleus pulposus (NP) and annulus fibrosus (AF) cell cultures. Immunohistochemical studies in human biopsies showed significant activation of both signaling pathways, which was most prominent in the clusters of proliferating cells. These in vitro and in vivo data indicate that the proliferation of human IVD cells is regulated by exogenous and autocrine growth factors mainly via the MEK/ERK and PI-3K/Akt pathways; this may contribute to the design of future interventional approaches.
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Affiliation(s)
- Harris Pratsinis
- Laboratory of Cell Proliferation and Ageing, Institute of Biology, NCSR Demokritos, 153 10 Athens, Greece
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Annulus cells from more degenerated human discs show modified gene expression in 3D culture compared with expression in cells from healthier discs. Spine J 2010; 10:721-7. [PMID: 20650410 DOI: 10.1016/j.spinee.2010.05.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Revised: 04/06/2010] [Accepted: 05/22/2010] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Understanding gene expression patterns of disc cells in culture is important as we develop biologic therapies for disc degeneration. The objective of the present study was to determine if cells from more degenerated discs expressed different genes, or differed in their expression patterns, compared with patterns of cells from healthier discs. PURPOSE To determine if annulus cells from more degenerated discs expressed different gene expression patterns compared with patterns of cells from healthier discs using genome-wide analysis. STUDY DESIGN Cells from human annulus tissue were grown in three-dimensional (3D) culture and their gene expression patterns analyzed with Affymetrix microarray analysis. Gene expression patterns of cells from more degenerated discs (Thompson Grades IV and V) were compared with patterns from cells from healthier discs (Thompson Grades I, II, and III). METHODS After approval by our human subjects institutional review board, annulus cells were obtained from lumbar discs of seven subjects with Thompson Grades I, II, or III and from five subjects with discs of Thompson Grades IV and V. Cells were grown in 3D culture for 2 weeks; 3D cultures were used because this microenvironment more closely mimics the in vivo condition. mRNA was harvested, processed for Affymetrix genome-wide gene analysis, and data analyzed with p values adjusted so as to compensate for false discovery rates. RESULTS GeneSifter analyses showed that cells from more degenerated discs had 320 genes significantly upregulated, and 104 genes significantly downregulated compared with cells from healthier discs. Important genes included those related to: 1) the extracellular matrix (ECM) (keratin-associated protein 1-1, hyaluronan synthase 2, and nexin were upregulated; biglycan, collagen type VI alpha 2, thrombospondin 3, laminen alpha 1, fibronectin type III domain-containing protein 1, elastin microfibril interfacer 2, fibulin 2, and nidogen 1 and 2 were downregulated); 2) ECM proteolysis (ADAMTS6 was upregulated); 3) cell proliferation (never in mitosis gene 1-related kinase 3, cell division cycle 2-like 5 [cholinesterase-related cell division controller], RAB42 [member of RAS oncogene family], and cyclin-dependent kinase 6 were upregulated; RAS-like GTP-binding 1 was downregulated); 4) apoptosis (BCL2-like 11 and p53-inducible nuclear protein 1 were upregulated; caspase recruitment domain family, member 10, caspase-1 dominant-negative inhibitor pseudo-ICE, and caspase 9 and FADD-like apoptosis regulator were downregulated); and 5) growth factors, inflammatory mediators, and other genes (fibroblast growth factor 1, pregnancy-associated plasma protein-A, interleukin 1 alpha, and interleukin 7 were upregulated; TGF-beta-induced transcript 1, interleukin 26 and interleukin 1 receptor-like 1, tumor necrosis factor, alpha-induced protein 2, and chemokine (C-X3-C motif) ligand 1 were downregulated). CONCLUSIONS Data presented here show that annulus cells from more degenerated discs show modified gene expression in 3D culture. Important gene variations involved expression of interleukins, cytokines, ECM components, and apoptosis regulators. Results presented here have potential application in future cell-based biologic therapies for disc degeneration.
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Abstract
STUDY DESIGN Micromass culture was assessed as a cell culture microenvironment for anulus cells from the human intervertebral disc. OBJECTIVE To determine whether the micromass culture technique might be useful for the culture of human anulus cells. SUMMARY OF BACKGROUND DATA Culture of cells in micromass has been traditionally used as a method to culture chondrocytes in a three-dimensional (3D) microenvironment with specialized chondrocyte media which allows expression of the chondrocytic phenotype. Recently it has also been used for disc cell 3D culture. METHODS Following approval of our human subjects Institutional Review Board, cells isolated from human anulus intervertebral disc tissue was cultured in micromass culture under control conditions or with addition of 5 ng/mL transforming growth factor-beta (TGF-beta). Cultures were grown for 7 days, and then analyzed for morphology with light microscopy, for extracellular matrix (ECM) production with transmission electron microscopy and quantitative measurement of total sulfated proteoglycan production. Immunohistochemistry was also performed to assess types I and II collagen, decorin, keratan sulfate, and chondroitin sulfate content of ECM. RESULTS Human anulus cells form multilayered colonies when cultured with minimal media and 20% fetal bovine serum in the micromass methodology. Stimulation of ECM production occurs when 5 ng/mL TGF-beta was added to the micromass media. TGF-beta also significantly increased the production of sulfated proteoglycans (P = 0.026). Under both control and TGF-beta-supplementation, the resulting micromass formed by anulus cells is not as compact as the micromass which results when stem cells cultured in chondrogenic media. Ultrastructural studies showed the presence of apoptotic cells and the presence of peroxisomes within cells. Immunohistochemical studies on production of type I collagen, decorin and keratan sulfate showed that there was localized production of these ECM components in focal regions; chondroitin sulfate and type II collagen, however, showed a more uniform overall production by cells within the micromass. CONCLUSION Human anulus cells were successfully cultured under micromass conditions in nonchondrogenic media and with TGF-beta supplementation which increased ECM production. The resulting anulus cell micromass, however, was not as rounded or compact as that which occurs with routine chondrocyte micromass or stem cells induced into chondrocyte differentiation. The presence of peroxisomes noted on ultrastructural studies may reflect cell stress or uneven distribution of nutrition within the micromass during the 7-day micromass culture period. Immunohistochemical studies showed nonuniform ECM gene expression and production within the micromass, suggesting variable gene expression patterns with this culture method.
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Immunolocalization and biochemical evidence of pregnancy-associated plasma protein A in the intervertebral disc. Spine (Phila Pa 1976) 2008; 33:E447-54. [PMID: 18552658 DOI: 10.1097/brs.0b013e318178e642] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Studies were approved by the authors' Human Subjects Institutional Review Board and Institutional Animal Care and Use Committee. Anulus tissue was used in studies of the immunocytochemical localization of pregnancy-associated plasma protein A (PAPP-A) in disc tissue from the sand rat and from human disc surgical specimens and specimens from control donors. Cultured human disc cells were also tested for production of PAPP-A. OBJECTIVES (1) To determine the immunohistochemical localization of PAPP-A in human and sand rat discs; (2) To test for gene expression of PAPP-A in the human disc in vivo and in vitro production by cultured cells; and (3) To test for expression of insulin-like growth factor binding proteins (IGFBP)-2, -4, and -5 in vivo and in vitro by human disc cells. SUMMARY OF BACKGROUND DATA PAPP-A is a metalloproteinase expressed by several cell types, including fibroblasts, osteoblasts, and smooth muscle cells. PAPP-A has an extremely important role because it cleaves IGFBP-2, -4, and -5 in the extracellular matrix, thereby increasing the bioavailability of IGF to nearby cells. METHODS.: Specimens of human disc tissue and lumbar discs from sand rats were assessed for immunocytochemical localization of PAPP-A, and the percentage of positive cells determined. Human disc cells in three-dimensional culture were assessed for production of PAPP-A using an enzyme linked immunosorbent assay. Molecular gene expression studies were carried out using microarray analysis. RESULTS Positive cytoplasmic immunolocalization of PAPP-A was present in the majority of cells of the human and sand rat outer anulus (OA). In the human outer anulus, the percentage of cells positive for PAPP-A localization did not differ in Grades I-II discs vs. Grades III-V discs (OA: 77.4% +/- 10.5 vs. 75.1% +/- 7.4 [mean +/- SEM] respectively). In the inner anulus, however, the percentage of cells positive for PAPP-A localization in more degenerate discs was significantly greater than the percentage in healthier discs (60.7% +/- 10.1 vs. 15.6 +/- 5.4, P = 0.024). % positive cells in the inner anulus correlated significantly with disc grade (r = 0.579; P = 0.01). Over a 5-day three-dimensional culture period, human anulus cells produced and secreted abundant PAPP-A into the culture media. Molecular studies confirmed the expression of IGFBP-2, -4, and -5 both in vivo and in vitro. CONCLUSIONS Data provide important new insights into disc cell expression of PAPP-A at the translational level. The presence of a significantly greater proportion of cells positive for PAPP-A in the inner anulus of more degenerate Grade III-V discs compared with healthier Grade I-II discs supports our previous observation of increased gene expression of PAPP-A in more degenerated discs. Biochemical data shown here documented production of PAPP-A by disc cells in vitro. Production of PAPP-A by disc cells is important since PAPP-A cleaves IGF-binding proteins, and makes IGF-I, a potent mitogen and antiapoptotic agent, available to cells. Future studies are indicated to further investigate PAPP-A and IGF-BP function in the disc.
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Abstract
Intervertebral disc degeneration is a complex age-related pathology associated with back pain. Research on the growth factors that regulate disc homeostasis is of critical importance for understanding the basis of the disease. Here we summarize the data on the expression and function of various growth factors in the disc from in vivo and in vitro studies, as well as on their alterations during degeneration and ageing. Such studies are becoming more crucial in the prospect of clinical application of growth factors for the treatment of disc degeneration.
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Affiliation(s)
- Harris Pratsinis
- Laboratory of Cell Proliferation & Ageing, Institute of Biology, NCSR, Athens, Greece
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Zhao CQ, Wang LM, Jiang LS, Dai LY. The cell biology of intervertebral disc aging and degeneration. Ageing Res Rev 2007; 6:247-61. [PMID: 17870673 DOI: 10.1016/j.arr.2007.08.001] [Citation(s) in RCA: 290] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2007] [Revised: 08/02/2007] [Accepted: 08/07/2007] [Indexed: 12/18/2022]
Abstract
Intervertebral disc degeneration, which mimics disc aging but occurs at an accelerated rate, is considered to be related to neck or low back pain and disc herniation. Degenerated discs show breakdown of the extracellular matrix and thus fail to bear the daily loadings exerted on the spine. Rather than a passive process of wear and tear, disc degeneration is an aberrant, cell-mediated response to progressive structural failure due to aging and other environmental factors such as abnormal mechanical stress. With aging and degeneration, disc cells undergo substantially biologic changes, including alternation of cell type in the nucleus pulposus, increased cell density but decreased number of viable cells as a result of increased cell death and increased cell proliferation, increased cell senescence, and altered cell phenotype which is characterized by compromised capability of synthesizing correct matrix components and by enhanced catabolic metabolism. These changes are involved in the process of disc degeneration through the complicated interactions among them. To retard or reverse disc degeneration, the abnormal conditions of the decreased viable cell population and the altered cell phenotype should be corrected. As potential therapies for disc degeneration, intradiscal protein injection, gene transfer and cell implantation are being understudied in vivo. Suppression of excessive apoptosis and accelerated senescence of disc cells may be other choices for treating disc degeneration. When performing a biologic therapy in order to repair or regenerate the degenerated disc, nutrient and biomechanical factors should also be incorporated, because they are the major causes of the biologic changes experienced by disc cells. Moreover, a very early intervention is indicated by the finding that the onset of human disc degeneration occurs as early as by adolescence.
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Affiliation(s)
- Chang-Qing Zhao
- Department of Orthopaedic Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, 1665 Kongjiang Road, 200092 Shanghai, China
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Pratsinis H, Kletsas D. PDGF, bFGF and IGF-I stimulate the proliferation of intervertebral disc cells in vitro via the activation of the ERK and Akt signaling pathways. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2007; 16:1858-66. [PMID: 17763874 PMCID: PMC2223343 DOI: 10.1007/s00586-007-0408-9] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 12/20/2006] [Revised: 03/12/2007] [Accepted: 05/14/2007] [Indexed: 02/08/2023]
Abstract
Intervertebral disc (IVD) degeneration is frequently characterized by increased cell proliferation, probably as a tissue regenerative response. Although many growth factors and their receptors have been shown to be expressed normally in the disc, and generally to be over-expressed during degeneration, not all of them have been thoroughly studied concerning their effects on IVD cell proliferation. In the present report, three potent mitogens, platelet-derived growth factor (PDGF), basic fibroblast growth factor (bFGF) and insulin-like growth factor-I (IGF-I) are examined regarding their capacity to induce proliferation in vitro of bovine coccygeal nucleus pulposus (NP) and annulus fibrosus (AF) cells, as well as to activate major intracellular signal transduction pathways. PDGF, bFGF and IGF-I were found to induce DNA synthesis in quiescent IVD cells in a dose-dependent manner. Maximum stimulation was induced by PDGF, while stimulation by all three factors simultaneously exceeded only slightly that caused by PDGF alone. All three growth factors were shown to phosphorylate immediately extracellular-signal regulated kinases (ERKs), while the stimulation by bFGF especially resulted in sustained ERK phosphorylation. Furthermore, all three growth factors induced phosphorylation of Akt in both Thr308 and Ser473 residues immediately after stimulation, although bFGF-induced phosphorylation was much weaker than that provoked by PDGF and IGF-I. In addition, the MEK inhibitor PD98059 and the PI 3-K inhibitor wortmannin were shown to block growth factor-induced ERK- and Akt-phosphorylation, respectively, in IVD cells. Inhibition of the MEK/ERK or the PI 3-K/Akt pathways provoked a significant decline of the proliferative effects of PDGF, bFGF or IGF-I on IVD cell cultures, while the simultaneous inhibition of both signaling pathways abolished completely the mitogenicity of these growth factors. The above effects of the three growth factors were reproduced similarly in both NP and AF cell cultures. Overall, the above results indicate that PDGF, bFGF and IGF-I stimulate the proliferation of IVD cells via the ERK and Akt signaling pathways.
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Affiliation(s)
- Harris Pratsinis
- Laboratory of Cell Proliferation and Ageing, Institute of Biology, National Centre for Scientific Research “Demokritos”, 153 10 Athens, Greece
| | - Dimitris Kletsas
- Laboratory of Cell Proliferation and Ageing, Institute of Biology, National Centre for Scientific Research “Demokritos”, 153 10 Athens, Greece
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Gruber HE, Leslie K, Norton HJ, Heiner D, Patt J, Hanley EN. Demographic factors that influence human disc cell proliferation in vitro. Spine J 2006; 6:120-4. [PMID: 16517381 DOI: 10.1016/j.spinee.2005.05.383] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2005] [Revised: 04/29/2005] [Accepted: 05/19/2005] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Although previous work has shown that greater age, greater disc degeneration, female gender, and surgical derivation of disc tissue had deleterious effects on cell proliferative potential, relatively little is known about the association between disc cell proliferation in vitro and clinical donor characteristics. PURPOSE To identify the relationships between donor characteristic and the in vitro proliferative potential of human disc cells from the annulus. STUDY DESIGN/SETTING Studies were approved by the human subjects Institutional Review Board. Donor data included donor source, ethnicity, age, gender, smoking history, height, weight, number of years of back pain, and Thompson score. Cells cultured from the annulus were tested for proliferation. PATIENT SAMPLE There were two study populations: 1) Comparison Group (32 control donors and 33 control surgical subjects; 60 Caucasians, 5 African-Americans). Cell proliferation, age, Thompson score, height, weight, and smoking history were statistically analyzed for control donors versus control surgical group. No significant differences were present, and these two groups were pooled to form the Comparison Group. 2) Nineteen subjects from the United Arab Emirates who underwent disc surgery. OUTCOME MEASURES Linear models were fit to the data to determine the best prediction of cell proliferation as the outcome variable; multiple R-squared was used to determine model goodness of fit. METHODS Control donor specimens were obtained from the National Cancer Institute Cooperative Human Tissue Network, and control donor surgical specimens from disc surgeries. A standardized cell proliferation assay was used to evaluate monolayer and three-dimensional agarose cell proliferation. Data were expressed as mean cpm[(3)H]-thymidine per microgram deoxyribonucleic acid+/-SEM. Standard statistical methods used the SAS system for data analysis. RESULTS No differences were present in the Comparison Group versus the Middle Eastern group for mean Thompson score (both averaged grade III), mean age (44.3 vs. 43.0 years, respectively), gender, height, weight, length of time with back pain (1.9 years vs. 2.1 years respectively), or smoking history. Three-dimensional proliferation in agarose was not significantly different for the two groups. Monolayer proliferation, however, was significantly different (17,434+/-2,929 vs. 6,693+/-2,103, respectively), p=.019. Linear regression models were fit to the data to determine the best prediction using proliferation as the outcome variable. In the Middle Eastern group, monolayer cell proliferation bore a significant negative correlation to age (p=.02, r=-.32), whereas the Comparison Group showed no such relationship. The following equation was derived to fit these data: Log(10) of proliferation (cpm/mug deoxyribonucleic acid)=10.915-0.7919 (Middle Eastern ethnicity)-0.0296 (Age). The r(2) for this equation is 0.203 (ie, 20.3% of the change in proliferation is explained by age and Middle Eastern ethnicity). Middle Eastern ethnicity and age were significant in this equation (p=.04 and .0003, respectively). CONCLUSIONS Studies have shown that familial history, age, and smoking are important risk factors for disc degeneration in Arabic pedigrees. It is interesting that our present findings also point to age and familial history as important significant factors influencing monolayer proliferation. Further research is needed to identify the cellular basis for this influence on cellular proliferative capacity.
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Affiliation(s)
- Helen E Gruber
- Department of Orthopaedic Surgery, Carolinas Medical Center, 1000 Blyth Boulevard, Charlotte, NC 28232, USA.
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Abstract
Disc degeneration plays a major role in this country's medical, social and economic structure. The life-time prevalence of low back pain, which has disc degeneration as its cause, is about 80% in the general population. It is a primary cause of disability and estimated costs related to low back disorders exceed $100 billion per year in the U.S. alone. Biomarkers are becoming increasingly important as indicators of the presence of disease, and in evaluating outcomes during clinical treatment. Cell-based biologic therapies which are currently being developed to treat disc degeneration are going to be most efficacious when applied to the early stages of disc disease. In this article we ask: 1) Whether there are existing biomarkers which could play a role in detecting early stages of disc degeneration, and 2) Highlight exciting potentials in future biomarker screening for disc degeneration.
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Affiliation(s)
- Helen E. Gruber
- Department of Orthopaedic Surgery, Carolinas Medical Center, Charlotte, N.C
| | - Edward N. Hanley
- Department of Orthopaedic Surgery, Carolinas Medical Center, Charlotte, N.C
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Gruber HE, Leslie K, Ingram J, Hoelscher G, Norton HJ, Hanley EN. Colony formation and matrix production by human anulus cells: modulation in three-dimensional culture. Spine (Phila Pa 1976) 2004; 29:E267-74. [PMID: 15223948 DOI: 10.1097/01.brs.0000129029.10036.64] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Human intervertebral disc cells from the anulus were tested in a study of colony formation and extracellular matrix (ECM) production during long-term three-dimensional culture with exposure to selected cytokines. Experimental studies were approved by the authors' Human Subjects Institutional Review Board. OBJECTIVES To quantitatively evaluate colony formation and qualitatively assess ECM production (using immunohistochemistry and in situ hybridization) in cells derived from Thompson Grades I to V discs and tested in culture with cytokines and nutrient supplementation. SUMMARY OF THE BACKGROUND DATA Human intervertebral disc cells offer special in vitro challenges because of the slow-growing nature of these cells and their need for specialized three-dimensional in vitro conditions, which permit the expression and production of proteoglycans and Type II collagen, two ECM products that are important for disc cell biology. METHODS Discs from 9 human subjects (2 control donors and 7 surgical patients, Thompson Grades I-V), mean age 35.8 years, were used to obtain anulus cells to be tested in three-dimensional agarose culture. Tests of specialized growth conditions included treatment with ITS (insulin-transferrin-sodium selenite supplement), insulin-like growth factor I (IGF-I), and transforming growth factor-beta1 (TGF-beta1). Cultures were evaluated after 14 to 36 days of culture for % colony formation and cell numbers/colony; immunocytochemistry, in situ hybridization, and quantitative histology were used to evaluate colony formation and ECM production. RESULTS : Data showed that compared with the average 17.5% colony formation observed in controls, ITS, TGF-beta1 and ITS with IGF-I significantly increased colony formation (28.4%, 30.4%, and 30.4%, respectively, P < or = 0.04). Even cells derived from Thompson Grade V disc showed responsiveness to cytokines and improved production of ECM in vitro. CONCLUSIONS : Findings indicated that cells derived from discs with advanced degeneration were still responsive to cytokines and could be modulated to produce Type II collagen and proteoglycans in three-dimensional culture by the addition of enriched media and selected cytokines. Such findings are important since they advance our understanding of how to modulate disc cell behavior in vitro, and may have application to potential future biologic therapies for disc degeneration.
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Affiliation(s)
- Helen E Gruber
- Department of Orthopaedic Surgery, Carolinas Medical Center, Charlotte, NC 28232, USA.
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Abstract
STUDY DESIGN There have been many advances over the past decade in understanding and experimentally modulating biologic aspects of intervertebral disc cell function. An overview of the current state of this biologic research is presented. OBJECTIVES To provide clinicians with a review of important recent advances in biologic studies of the disc and their implications for potential disc therapies. SUMMARY OF BACKGROUND DATA Historically, anatomic, biochemical, radiologic, and biomechanical studies of the intervertebral disc formed the foundation on which our understanding of disc function was built. Magnetic resonance imaging techniques that allowed viewing of soft tissue components of the disc further advanced imaging capabilities. METHODS Recent publications are reviewed. RESULTS Experimental approaches over the past decade have enabled researchers to look more critically at disc cell function. This is important because disc cell function produces the extracellular matrix components of the disc, which, in turn, shape the disc's subsequent physiologic and biomechanical functions. New approaches to the study of disc cell function, methods to manipulate disc cells, studies of intact discs and disc nutrition, vertebral endplate structure and function, tissue engineering, gene therapy, and the potential of stem cells in disc therapy are reviewed and discussed. CONCLUSIONS Many believe that disc degeneration has a cellular basis. New research is helping us better understand healthy, aging, and degenerating discs. Modern methods to manipulate and modulate disc cell function open exciting and challenging new therapeutic possibilities for future biologic treatments of disc degeneration.
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Affiliation(s)
- Helen E Gruber
- Department of Orthopaedic Surgery, Carolinas Medical Center, Charlotte, North Carolina 28232, USA.
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