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Clayton SW, Sebastian A, Wilson SP, Hum NR, Walk RE, Easson GWD, Vaidya R, Broz KS, Loots GG, Tang SY. Single cell RNA sequencing reveals a shift in cell function and maturation of endogenous and infiltrating cell types in response to acute intervertebral disc injury. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.10.607363. [PMID: 39149307 PMCID: PMC11326235 DOI: 10.1101/2024.08.10.607363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/17/2024]
Abstract
Intervertebral disc (IVD) degeneration contributes to disabling back pain. Degeneration can be initiated by injury and progressively leads to irreversible cell loss and loss of IVD function. Attempts to restore IVD function through cell replacement therapies have had limited success due to knowledge gaps in critical cell populations and molecular crosstalk after injury. Here, we used single cell RNA sequencing to identify the transcriptional changes of endogenous and infiltrating IVD cell populations, as well as the potential of resident mesenchymal stem cells (MSCs) for tissue repair. Control and Injured (needle puncture) tail IVDs were extracted from 12 week old female C57BL/6 mice 7 days post injury and clustering analyses, gene ontology, and pseudotime trajectory analyses were used to determine transcriptomic divergences in the cells of the injured IVD, while immunofluorescence was utilized to determine mesenchymal stem cell (MSC) localization. Clustering analysis revealed 11 distinct cell populations that were IVD tissue specific, immune, or vascular cells. Differential gene expression analysis determined that Outer Annulus Fibrosus, Neutrophils, Saa2-High MSCs, Macrophages, and Krt18+ Nucleus Pulposus (NP) cells were the major drivers of transcriptomic differences between Control and Injured cells. Gene ontology of DEGs suggested that the most upregulated biological pathways were angiogenesis and T cell related while wound healing and ECM regulation categories were downregulated. Pseudotime trajectory analyses revealed that cells were driven towards increased cell differentiation due to IVD injury in all IVD tissue clusters except for Krt18+ NP which remained in a less mature cell state. Saa2-High and Grem1-High MSCs populations drifted towards more IVD differentiated cells profiles with injury and localized distinctly within the IVD. This study strengthens the understanding of heterogeneous IVD cell populations response to injury and identifies targetable MSC populations for future IVD repair studies.
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Affiliation(s)
| | - Aimy Sebastian
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore CA
| | - Stephen P Wilson
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore CA
| | - Nicholas R Hum
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore CA
| | - Remy E Walk
- Washington University in St. Louis, St. Louis MO
| | | | | | | | - Gabriela G Loots
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore CA
- Department of Orthopaedic Surgery, University of California Davis Health, Sacramento, CA, United States
| | - Simon Y Tang
- Washington University in St. Louis, St. Louis MO
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2
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Shi P, Gao H, Cheng Z, Zhao K, Chen Y, Chen X, Gan W, Zhang A, Yang C, Zhang Y. Static magnetic field-modulated mesenchymal stem cell-derived mitochondria-containing microvesicles for enhanced intervertebral disc degeneration therapy. J Nanobiotechnology 2024; 22:457. [PMID: 39085827 PMCID: PMC11290117 DOI: 10.1186/s12951-024-02728-6] [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: 03/05/2024] [Accepted: 07/17/2024] [Indexed: 08/02/2024] Open
Abstract
Intervertebral disc degeneration (IVDD) is characterized by the senescence and declining vitality of nucleus pulposus cells (NPCs), often driven by mitochondrial dysfunction. This study elucidates that mesenchymal stem cells (MSCs) play a crucial role in attenuating NPC senescence by secreting mitochondria-containing microvesicles (mitoMVs). Moreover, it demonstrates that static magnetic fields (SMF) enhance the secretion of mitoMVs by MSCs. By distinguishing mitoMV generation from exosomes, this study shifts focus to understanding the molecular mechanisms of SMF intervention, emphasizing cargo transport and plasma membrane budding processes, with RNA sequencing indicating the potential involvement of the microtubule-based transport protein Kif5b. The study further confirms the interaction between Rab22a and Kif5b, revealing Rab22a's role in sorting mitoMVs into microvesicles (MVs) and potentially mediating subsequent plasma membrane budding. Subsequent construction of a gelatin methacrylate (GelMA) hydrogel delivery system further addresses the challenges of in vivo application and verifies the substantial potential of mitoMVs in delaying IVDD. This research not only sheds light on the molecular intricacies of SMF-enhanced mitoMV secretion but also provides innovative perspectives for future IVDD therapeutic strategies.
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Affiliation(s)
- Pengzhi Shi
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Haiyang Gao
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Zhangrong Cheng
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Kangcheng Zhao
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Yuhang Chen
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Xianglong Chen
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Weikang Gan
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Anran Zhang
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Cao Yang
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Yukun Zhang
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
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3
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Yang S, Jing S, Wang S, Jia F. From drugs to biomaterials: a review of emerging therapeutic strategies for intervertebral disc inflammation. Front Cell Infect Microbiol 2024; 14:1303645. [PMID: 38352058 PMCID: PMC10861683 DOI: 10.3389/fcimb.2024.1303645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 01/12/2024] [Indexed: 02/16/2024] Open
Abstract
Chronic low back pain (LBP) is an increasingly prevalent issue, especially among aging populations. A major underlying cause of LBP is intervertebral disc degeneration (IDD), often triggered by intervertebral disc (IVD) inflammation. Inflammation of the IVD is divided into Septic and Aseptic inflammation. Conservative therapy and surgical treatment often fail to address the root cause of IDD. Recent advances in the treatment of IVD infection and inflammation range from antibiotics and small-molecule drugs to cellular therapies, biological agents, and innovative biomaterials. This review sheds light on the complex mechanisms of IVD inflammation and physiological and biochemical processes of IDD. Furthermore, it provides an overview of recent research developments in this area, intending to identify novel therapeutic targets and guide future clinical strategies for effectively treating IVD-related conditions.
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Affiliation(s)
- Shuhan Yang
- Department of Orthopedics, Third Hospital of Shanxi Medical University, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Taiyuan, China
| | - Shaoze Jing
- Department of Orthopedics, Third Hospital of Shanxi Medical University, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Taiyuan, China
| | - Shanxi Wang
- Department of Spine Surgery, Honghui Hospital, Xi’an Jiaotong University, Xi’an, China
| | - Fajing Jia
- Department of General Practice, Third Hospital of Shanxi Medical University, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Taiyuan, China
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Samanta A, Lufkin T, Kraus P. Intervertebral disc degeneration-Current therapeutic options and challenges. Front Public Health 2023; 11:1156749. [PMID: 37483952 PMCID: PMC10359191 DOI: 10.3389/fpubh.2023.1156749] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 06/12/2023] [Indexed: 07/25/2023] Open
Abstract
Degeneration of the intervertebral disc (IVD) is a normal part of aging. Due to the spine's declining function and the development of pain, it may affect one's physical health, mental health, and socioeconomic status. Most of the intervertebral disc degeneration (IVDD) therapies today focus on the symptoms of low back pain rather than the underlying etiology or mechanical function of the disc. The deteriorated disc is typically not restored by conservative or surgical therapies that largely focus on correcting symptoms and structural abnormalities. To enhance the clinical outcome and the quality of life of a patient, several therapeutic modalities have been created. In this review, we discuss genetic and environmental causes of IVDD and describe promising modern endogenous and exogenous therapeutic approaches including their applicability and relevance to the degeneration process.
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Lufkin L, Samanta A, Baker D, Lufkin S, Schulze J, Ellis B, Rose J, Lufkin T, Kraus P. Glis1 and oxaloacetate in nucleus pulposus stromal cell somatic reprogramming and survival. Front Mol Biosci 2022; 9:1009402. [PMID: 36406265 PMCID: PMC9671658 DOI: 10.3389/fmolb.2022.1009402] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Accepted: 10/10/2022] [Indexed: 12/04/2022] Open
Abstract
Regenerative medicine aims to repair degenerate tissue through cell refurbishment with minimally invasive procedures. Adipose tissue (FAT)-derived stem or stromal cells are a convenient autologous choice for many regenerative cell therapy approaches. The intervertebral disc (IVD) is a suitable target. Comprised of an inner nucleus pulposus (NP) and an outer annulus fibrosus (AF), the degeneration of the IVD through trauma or aging presents a substantial socio-economic burden worldwide. The avascular nature of the mature NP forces cells to reside in a unique environment with increased lactate levels, conditions that pose a challenge to cell-based therapies. We assessed adipose and IVD tissue-derived stromal cells through in vitro transcriptome analysis in 2D and 3D culture and suggested that the transcription factor Glis1 and metabolite oxaloacetic acid (OAA) could provide NP cells with survival tools for the harsh niche conditions in the IVD.
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Affiliation(s)
- Leon Lufkin
- Department of Statistics and Data Science, Yale University, New Haven, CT, United States,The Clarkson School, Clarkson University, Potsdam, NY, United States
| | - Ankita Samanta
- Department of Biology, Clarkson University, Potsdam, NY, United States
| | - DeVaun Baker
- The Clarkson School, Clarkson University, Potsdam, NY, United States,Department of Biology, Clarkson University, Potsdam, NY, United States
| | - Sina Lufkin
- The Clarkson School, Clarkson University, Potsdam, NY, United States,Department of Biology, Clarkson University, Potsdam, NY, United States
| | | | - Benjamin Ellis
- Department of Biology, Clarkson University, Potsdam, NY, United States
| | - Jillian Rose
- Department of Biology, Clarkson University, Potsdam, NY, United States
| | - Thomas Lufkin
- Department of Biology, Clarkson University, Potsdam, NY, United States
| | - Petra Kraus
- Department of Biology, Clarkson University, Potsdam, NY, United States,*Correspondence: Petra Kraus,
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Single-Cell RNA-Seq Analysis of Cells from Degenerating and Non-Degenerating Intervertebral Discs from the Same Individual Reveals New Biomarkers for Intervertebral Disc Degeneration. Int J Mol Sci 2022; 23:ijms23073993. [PMID: 35409356 PMCID: PMC8999935 DOI: 10.3390/ijms23073993] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 03/31/2022] [Accepted: 04/01/2022] [Indexed: 02/07/2023] Open
Abstract
In this study, we used single-cell transcriptomic analysis to identify new specific biomarkers for nucleus pulposus (NP) and inner annulus fibrosis (iAF) cells, and to define cell populations within non-degenerating (nD) and degenerating (D) human intervertebral discs (IVD) of the same individual. Cluster analysis based on differential gene expression delineated 14 cell clusters. Gene expression profiles at single-cell resolution revealed the potential functional differences linked to degeneration, and among NP and iAF subpopulations. GO and KEGG analyses discovered molecular functions, biological processes, and transcription factors linked to cell type and degeneration state. We propose two lists of biomarkers, one as specific cell type, including C2orf40, MGP, MSMP, CD44, EIF1, LGALS1, RGCC, EPYC, HILPDA, ACAN, MT1F, CHI3L1, ID1, ID3 and TMED2. The second list proposes predictive IVD degeneration genes, including MT1G, SPP1, HMGA1, FN1, FBXO2, SPARC, VIM, CTGF, MGST1, TAF1D, CAPS, SPTSSB, S100A1, CHI3L2, PLA2G2A, TNRSF11B, FGFBP2, MGP, SLPI, DCN, MT-ND2, MTCYB, ADIRF, FRZB, CLEC3A, UPP1, S100A2, PRG4, COL2A1, SOD2 and MT2A. Protein and mRNA expression of MGST1, vimentin, SOD2 and SYF2 (p29) genes validated our scRNA-seq findings. Our data provide new insights into disc cells phenotypes and biomarkers of IVD degeneration that could improve diagnostic and therapeutic options.
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Varden LJ, Turner EJ, Coon AT, Michalek AJ. Establishing a through-puncture model for assessing post-injection leakage in the intervertebral disc. 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 2022; 31:865-873. [PMID: 35179651 DOI: 10.1007/s00586-022-07140-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 01/12/2022] [Accepted: 01/31/2022] [Indexed: 01/07/2023]
Abstract
PURPOSE Needle injection through the outer annulus fibrosus of the intervertebral disc (IVD) is the most practical approach for delivery of therapeutic agents, which have been shown to potentially leak following needle retraction. The goal of this work was to establish a protocol for quantifying post-injection leakage and test its sensitivity to factors believed to affect needle track geometry. METHODS A through-puncture defect procedure, followed by controlled injection, was performed on bovine caudal IVDs. Sensitivity to needle size was tested by injection of saline into unconstrained discs with either a 30G, 26G, or 21G hypodermic needle. Sensitivity to axial load was tested by repeated injection via a 26G needle with either no constraint, fixed height, or 10% axial compressive strain. Sensitivity to flexion was tested by applying combined 0.2 MPa compression and 15° of flexion following injection of 5% of disc volume. RESULTS Needle diameter significantly affected maximum volume prior to leakage, ranging from 34.6 ± 31.9 µL when using 21G to 115.6 ± 23.6 µL when using 30G. While all unloaded discs leaked, axial compression decreased the incidence of leakage events by 50-100% depending on load history. Forward flexion resulted in a 22% incidence of leakage. CONCLUSION Fluid injected into IVDs is at significant risk of leakage following needle retraction. This risk depends on factors which alter the geometry of the needle track, including needle size, pinching due to axial compression, and stretching as a result of forward flexion.
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Affiliation(s)
- Lara J Varden
- Department of Biology, Clarkson University, Potsdam, NY, USA
| | - Evan J Turner
- Department of Mechanical and Aerospace Engineering, Clarkson University, 8 Clarkson Ave, Box 5725, Potsdam, NY, USA
| | - Allison T Coon
- Department of Mechanical and Aerospace Engineering, Clarkson University, 8 Clarkson Ave, Box 5725, Potsdam, NY, USA
| | - Arthur J Michalek
- Department of Mechanical and Aerospace Engineering, Clarkson University, 8 Clarkson Ave, Box 5725, Potsdam, NY, USA.
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Zhang Y, Wang J, Yu C, Xia K, Yang B, Zhang Y, Ying L, Wang C, Huang X, Chen Q, Shen L, Li F, Liang C. Advances in single-cell sequencing and its application to musculoskeletal system research. Cell Prolif 2022; 55:e13161. [PMID: 34888976 PMCID: PMC8780907 DOI: 10.1111/cpr.13161] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 10/30/2021] [Accepted: 11/12/2021] [Indexed: 11/30/2022] Open
Abstract
In recent years, single-cell sequencing (SCS) technologies have continued to advance with improved operating procedures and reduced cost, leading to increasing practical adoption among researchers. These emerging technologies have superior abilities to analyse cell heterogeneity at a single-cell level, which have elevated multi-omics research to a higher level. In some fields of research, application of SCS has enabled many valuable discoveries, and musculoskeletal system offers typical examples. This article reviews some major scientific issues and recent advances in musculoskeletal system. In addition, combined with SCS technologies, the research of cell or tissue heterogeneity in limb development and various musculoskeletal system clinical diseases also provides new possibilities for treatment strategies. Finally, this article discusses the challenges and future development potential of SCS and recommends the direction of future applications of SCS to musculoskeletal medicine.
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Affiliation(s)
- Yongxiang Zhang
- Department of Orthopedics SurgeryThe Second Affiliated HospitalZhejiang University School of MedicineHangzhouZhejiangChina
- Zhejiang Key Laboratory of Bone and Joint Precision and Department of OrthopedicsResearch Institute of Zhejiang UniversityHangzhouZhejiangChina
| | - Jingkai Wang
- Department of Orthopedics SurgeryThe Second Affiliated HospitalZhejiang University School of MedicineHangzhouZhejiangChina
- Zhejiang Key Laboratory of Bone and Joint Precision and Department of OrthopedicsResearch Institute of Zhejiang UniversityHangzhouZhejiangChina
| | - Chao Yu
- Department of Orthopedics SurgeryThe Second Affiliated HospitalZhejiang University School of MedicineHangzhouZhejiangChina
- Zhejiang Key Laboratory of Bone and Joint Precision and Department of OrthopedicsResearch Institute of Zhejiang UniversityHangzhouZhejiangChina
| | - Kaishun Xia
- Department of Orthopedics SurgeryThe Second Affiliated HospitalZhejiang University School of MedicineHangzhouZhejiangChina
- Zhejiang Key Laboratory of Bone and Joint Precision and Department of OrthopedicsResearch Institute of Zhejiang UniversityHangzhouZhejiangChina
| | - Biao Yang
- Department of Orthopedics SurgeryThe Second Affiliated HospitalZhejiang University School of MedicineHangzhouZhejiangChina
- Zhejiang Key Laboratory of Bone and Joint Precision and Department of OrthopedicsResearch Institute of Zhejiang UniversityHangzhouZhejiangChina
| | - Yuang Zhang
- Department of Orthopedics SurgeryThe Second Affiliated HospitalZhejiang University School of MedicineHangzhouZhejiangChina
- Zhejiang Key Laboratory of Bone and Joint Precision and Department of OrthopedicsResearch Institute of Zhejiang UniversityHangzhouZhejiangChina
| | - Liwei Ying
- Department of Orthopedics SurgeryThe Second Affiliated HospitalZhejiang University School of MedicineHangzhouZhejiangChina
- Zhejiang Key Laboratory of Bone and Joint Precision and Department of OrthopedicsResearch Institute of Zhejiang UniversityHangzhouZhejiangChina
| | - Chenggui Wang
- Department of Orthopedics SurgeryThe Second Affiliated HospitalZhejiang University School of MedicineHangzhouZhejiangChina
- Zhejiang Key Laboratory of Bone and Joint Precision and Department of OrthopedicsResearch Institute of Zhejiang UniversityHangzhouZhejiangChina
| | - Xianpeng Huang
- Department of Orthopedics SurgeryThe Second Affiliated HospitalZhejiang University School of MedicineHangzhouZhejiangChina
- Zhejiang Key Laboratory of Bone and Joint Precision and Department of OrthopedicsResearch Institute of Zhejiang UniversityHangzhouZhejiangChina
| | - Qixin Chen
- Department of Orthopedics SurgeryThe Second Affiliated HospitalZhejiang University School of MedicineHangzhouZhejiangChina
- Zhejiang Key Laboratory of Bone and Joint Precision and Department of OrthopedicsResearch Institute of Zhejiang UniversityHangzhouZhejiangChina
| | - Li Shen
- Department of Orthopedics SurgeryThe Second Affiliated HospitalZhejiang University School of MedicineHangzhouZhejiangChina
- The MOE Key Laboratory of Biosystems Homeostasis & Protection and Zhejiang Provincial Key Laboratory for Cancer Molecular Cell BiologyLife Sciences InstituteZhejiang UniversityHangzhouChina
- Hangzhou Innovation CenterZhejiang UniversityHangzhouChina
| | - Fangcai Li
- Department of Orthopedics SurgeryThe Second Affiliated HospitalZhejiang University School of MedicineHangzhouZhejiangChina
- Zhejiang Key Laboratory of Bone and Joint Precision and Department of OrthopedicsResearch Institute of Zhejiang UniversityHangzhouZhejiangChina
| | - Chengzhen Liang
- Department of Orthopedics SurgeryThe Second Affiliated HospitalZhejiang University School of MedicineHangzhouZhejiangChina
- Zhejiang Key Laboratory of Bone and Joint Precision and Department of OrthopedicsResearch Institute of Zhejiang UniversityHangzhouZhejiangChina
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KRAUS P, SAMANTA A, LUFKIN S, LUFKIN T. Stem cells in intervertebral disc regeneration-more talk than action? BIOCELL 2021; 46:893-898. [PMID: 34966192 PMCID: PMC8713956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Pain and lifestyle changes are common consequences of intervertebral disc degeneration (IVDD) and affect a large part of the aging population. The stemness of cells is exploited in the field of regenerative medicine as key to treat degenerative diseases. Transplanted cells however often face delivery and survival challenges, especially in tissues with a naturally harsh microniche environment such as the intervertebral disc. Recent interest in the secretome of stem cells, especially cargo protected from microniche-related decay as frequently present in degenerating tissues, provides new means of rejuvenating ailing cells and tissues. Exosomes, a type of extracellular vesicles with purposeful cargo gained particular interest in conveying stem cell related attributes of rejuvenation, which will be discussed here in the context of IVDD.
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Affiliation(s)
- Petra KRAUS
- Department of Biology, Clarkson University, Potsdam, NY 13699, USA, Address correspondence to: Petra Kraus,
| | - Ankita SAMANTA
- Department of Biology, Clarkson University, Potsdam, NY 13699, USA
| | - Sina LUFKIN
- The Clarkson School, Clarkson University, Potsdam, NY 13699, USA
| | - Thomas LUFKIN
- Department of Biology, Clarkson University, Potsdam, NY 13699, USA
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The Application of Mesenchymal Stromal Cells and Their Homing Capabilities to Regenerate the Intervertebral Disc. Int J Mol Sci 2021; 22:ijms22073519. [PMID: 33805356 PMCID: PMC8036861 DOI: 10.3390/ijms22073519] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 03/25/2021] [Accepted: 03/26/2021] [Indexed: 12/12/2022] Open
Abstract
Chronic low back pain (LBP) remains a challenging condition to treat, and especially to cure. If conservative treatment approaches fail, the current “gold standard” for intervertebral disc degeneration (IDD)-provoked back pain is spinal fusion. However, due to its invasive and destructive nature, the focus of orthopedic research related to the intervertebral disc (IVD) has shifted more towards cell-based therapeutic approaches. They aim to reduce or even reverse the degenerative cascade by mimicking the human body’s physiological healing system. The implementation of progenitor and/or stem cells and, in particular, the delivery of mesenchymal stromal cells (MSCs) has revealed significant potential to cure the degenerated/injured IVD. Over the past decade, many research groups have invested efforts to find ways to utilize these cells as efficiently and sustainably as possible. This narrative literature review presents a summary of achievements made with the application of MSCs for the regeneration of the IVD in recent years, including their preclinical and clinical applications. Moreover, this review presents state-of-the-art strategies on how the homing capabilities of MSCs can be utilized to repair damaged or degenerated IVDs, as well as their current limitations and future perspectives.
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Li K, Varden L, Henderson A, Lufkin T, Kraus P. Simultaneous detection of multiple mRNAs and proteins in bovine IVD cells and tissue with single cell resolution. Biotechnol Lett 2020; 43:13-24. [PMID: 32902710 DOI: 10.1007/s10529-020-02997-9] [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: 06/28/2020] [Accepted: 09/01/2020] [Indexed: 11/29/2022]
Abstract
OBJECTIVES Interactions of cells with their neighbors and influences by the surrounding extracellular matrix (ECM) is reflected in a cells transcriptome and proteome. In tissues comprised of heterogeneous cell populations or cells depending on ECM signalling cues such as those of the intervertebral disc (IVD), this information is obscured or lost when cells are pooled for the commonly used transcript analysis by quantitative PCR or RNA sequencing. Instead, these cells require means to analyse RNA transcript and protein distribution at a single cell or subcellular level to identify different cell types and functions, without removing them from their surrounding signalling cues. RESULTS We developed a simple, sequential protocol combining RNA is situ hybridisation (RISH) and immunohistochemistry (IHC) for the simultaneous analysis of multiple transcripts alongside proteins. This allows one to characterize heterogeneous cell populations at the single cell level in the natural cell environment and signalling context, both in vivo and in vitro. This protocol is demonstrated on cells of the bovine IVD, for transcripts and proteins involved in mechanotransduction, stemness and cell proliferation. CONCLUSIONS A simple, sequential protocol combining RISH and IHC is presented that allows for simultaneous information on RNA transcripts and proteins to characterize cells within a heterogeneous cell population and complex signalling environments such as those of the IVD.
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Affiliation(s)
- Kangning Li
- Department of Biology, Clarkson University, Potsdam, NY, USA
| | - Lara Varden
- Department of Biology, Clarkson University, Potsdam, NY, USA
| | | | - Thomas Lufkin
- Department of Biology, Clarkson University, Potsdam, NY, USA
| | - Petra Kraus
- Department of Biology, Clarkson University, Potsdam, NY, USA.
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Penolazzi L, Lambertini E, Bergamin LS, Roncada T, De Bonis P, Cavallo M, Piva R. MicroRNA-221 silencing attenuates the degenerated phenotype of intervertebral disc cells. Aging (Albany NY) 2019; 10:2001-2015. [PMID: 30130742 PMCID: PMC6128426 DOI: 10.18632/aging.101525] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 08/08/2018] [Indexed: 02/07/2023]
Abstract
The aim of this study was to investigate the role of an antichondrogenic factor, MIR221 (miR-221), in intervertebral disc degeneration (IDD), and provide basic information for the development of a therapeutic strategy for the disc repair based on specific nucleic acid based drugs, such as miR-221 silencing. We established a relatively quick protocol to minimize artifacts from extended in vitro culture, without selecting the different types of cells from intervertebral disc (IVD) or completely disrupting extracellular matrix (ECM), but by using the whole cell population with a part of resident ECM. During the de-differentiation process miR-221 expression significantly increased. We demonstrated the effectiveness of miR-221 silencing in driving the cells towards chondrogenic lineage. AntagomiR-221 treated cells showed in fact a significant increase of expression of typical chondrogenic markers including COL2A1, ACAN and SOX9, whose loss is associated with IDD. Moreover, antagomiR-221 treatment restored FOXO3 expression and increased TRPS1 expression levels attenuating the severity grade of degeneration, and demonstrating in a context of tissue degeneration and inflammation not investigated before, that FOXO3 is target of miR-221. Data of present study are promising in the definition of new molecules useful as potential intradiscal injectable biological agents.
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Affiliation(s)
- Letizia Penolazzi
- Department of Biomedical and Specialty Surgical Sciences, University of Ferrara, Ferrara, Italy
| | - Elisabetta Lambertini
- Department of Biomedical and Specialty Surgical Sciences, University of Ferrara, Ferrara, Italy
| | | | - Tosca Roncada
- Department of Biomedical and Specialty Surgical Sciences, University of Ferrara, Ferrara, Italy
| | - Pasquale De Bonis
- Department of Neurosurgery, S. Anna University Hospital, Ferrara, Italy
| | - Michele Cavallo
- Department of Neurosurgery, S. Anna University Hospital, Ferrara, Italy
| | - Roberta Piva
- Department of Biomedical and Specialty Surgical Sciences, University of Ferrara, Ferrara, Italy.,Center for Studies on Gender Medicine, University of Ferrara, Ferrara, Italy
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Han Y, Li X, Zhang Y, Han Y, Chang F, Ding J. Mesenchymal Stem Cells for Regenerative Medicine. Cells 2019; 8:E886. [PMID: 31412678 PMCID: PMC6721852 DOI: 10.3390/cells8080886] [Citation(s) in RCA: 627] [Impact Index Per Article: 125.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 08/05/2019] [Accepted: 08/06/2019] [Indexed: 02/06/2023] Open
Abstract
In recent decades, the biomedical applications of mesenchymal stem cells (MSCs) have attracted increasing attention. MSCs are easily extracted from the bone marrow, fat, and synovium, and differentiate into various cell lineages according to the requirements of specific biomedical applications. As MSCs do not express significant histocompatibility complexes and immune stimulating molecules, they are not detected by immune surveillance and do not lead to graft rejection after transplantation. These properties make them competent biomedical candidates, especially in tissue engineering. We present a brief overview of MSC extraction methods and subsequent potential for differentiation, and a comprehensive overview of their preclinical and clinical applications in regenerative medicine, and discuss future challenges.
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Affiliation(s)
- Yu Han
- Department of Orthopedics, The Second Hospital of Jilin University, 218 Ziqiang Street, Changchun 130041, China
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022, China
| | - Xuezhou Li
- Department of Orthopedics, The Second Hospital of Jilin University, 218 Ziqiang Street, Changchun 130041, China
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022, China
| | - Yanbo Zhang
- Department of Orthopedics, China-Japan Union Hospital of Jilin University, 126 Xiantai Street, Changchun 130033, China.
| | - Yuping Han
- Department of Urology, China-Japan Union Hospital of Jilin University, 126 Xiantai Street, Changchun 130033, China.
| | - Fei Chang
- Department of Orthopedics, The Second Hospital of Jilin University, 218 Ziqiang Street, Changchun 130041, China.
| | - Jianxun Ding
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022, China
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Quantitative Single-Cell Transcript Assessment of Biomarkers Supports Cellular Heterogeneity in the Bovine IVD. Vet Sci 2019; 6:vetsci6020042. [PMID: 31083612 PMCID: PMC6631975 DOI: 10.3390/vetsci6020042] [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] [Subscribe] [Scholar Register] [Received: 04/06/2019] [Revised: 05/05/2019] [Accepted: 05/09/2019] [Indexed: 02/06/2023] Open
Abstract
Severe and chronic low back pain is often associated with intervertebral disc (IVD) degeneration. While imposing a considerable socio-economic burden worldwide, IVD degeneration is also severely impacting on the quality of life of affected individuals. Cell-based regenerative medicine approaches have moved into clinical trials, yet IVD cell identities in the mature disc remain to be fully elucidated and tissue heterogeneity exists, requiring a better characterization of IVD cells. The bovine coccygeal IVD is an accepted research model to study IVD mechano-biology and disc homeostasis. Recently, we identified novel IVD biomarkers in the outer annulus fibrosus (AF) and nucleus pulposus (NP) of the mature bovine coccygeal IVD through RNA in situ hybridization (AP-RISH) and z-proportion test. Here we follow up on Lam1, Thy1, Gli1, Gli3, Noto, Ptprc, Scx, Sox2 and Zscan10 with fluorescent RNA in situ hybridization (FL-RISH) and confocal microscopy. This permits sub-cellular transcript localization and the addition of quantitative single-cell derived values of mRNA expression levels to our previous analysis. Lastly, we used a Gaussian mixture modeling approach for the exploratory analysis of IVD cells. This work complements our earlier cell population proportion-based study, confirms the previously proposed biomarkers and indicates even further heterogeneity of cells in the outer AF and NP of a mature IVD.
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Li K, Kapper D, Youngs B, Kocsis V, Mondal S, Kraus P, Lufkin T. Potential biomarkers of the mature intervertebral disc identified at the single cell level. J Anat 2018; 234:16-32. [PMID: 30450595 PMCID: PMC6284444 DOI: 10.1111/joa.12904] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/08/2018] [Indexed: 12/17/2022] Open
Abstract
Intervertebral disc (IVD) degeneration and trauma is a major socio-economic burden and the focus of cell-based regenerative medicine approaches. Despite numerous ongoing clinical trials attempting to replace ailing IVD cells with mesenchymal stem cells, a solid understanding of the identity and nature of cells in a healthy mature IVD is still in need of refinement. Although anatomically simple, the IVD is comprised of heterogeneous cell populations. Therefore, methods involving cell pooling for RNA profiling could be misleading. Here, by using RNA in situ hybridization and z proportion test, we have identified potential novel biomarkers through single cell assessment. We quantified the proportion of RNA transcribing cells for 50 genetic loci in the outer annulus fibrosus (AF) and nucleus pulposus (NP) in coccygeal bovine discs isolated from tails of four skeletally mature animals. Our data reconfirm existing data and suggest 10 novel markers such as Lam1 and Thy1 in the outer AF and Gli1, Gli3, Noto, Scx, Ptprc, Sox2, Zscan10 and LOC101904175 in the NP, including pluripotency markers, that indicate stemness potential of IVD cells. These markers could be added to existing biomarker panels for cell type characterization. Furthermore, our data once more demonstrate heterogeneity in cells of the AF and NP, indicating the need for single cell assessment by methods such as RNA in situ hybridization. Our work refines the molecular identity of outer AF and NP cells, which can benefit future regenerative medicine and tissue engineering strategies in humans.
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Affiliation(s)
- Kangning Li
- Department of Biology, Clarkson University, Potsdam, NY, USA
| | - Devin Kapper
- Department of Mathematics, Clarkson University, Potsdam, NY, USA
| | - Brittany Youngs
- Department of Biology, Clarkson University, Potsdam, NY, USA
| | - Victoria Kocsis
- Department of Biology, Clarkson University, Potsdam, NY, USA
| | - Sumona Mondal
- Department of Mathematics, Clarkson University, Potsdam, NY, USA
| | - Petra Kraus
- Department of Biology, Clarkson University, Potsdam, NY, USA
| | - Thomas Lufkin
- Department of Biology, Clarkson University, Potsdam, NY, USA
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Migliorini F, Rath B, Tingart M, Baroncini A, Quack V, Eschweiler J. Autogenic mesenchymal stem cells for intervertebral disc regeneration. INTERNATIONAL ORTHOPAEDICS 2018; 43:1027-1036. [PMID: 30415465 DOI: 10.1007/s00264-018-4218-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 10/29/2018] [Indexed: 12/17/2022]
Abstract
PURPOSE A systematic review of the literature was conducted to clarify the outcomes of autologous mesenchymal stem cells (MSC) injections for the regeneration of the intervertebral disc (IVD). METHODS The following databases were accessed: PubMed, Medline, CINAHL, Cochrane, Embase and Google Scholar bibliographic databases. Articles including previous or planned surgical interventions were excluded. Only articles reporting percutaneous autologous MSC injection to regenerate IVD in humans were included. We referred to the Coleman Methodology Score for the methodological quality assessment. The statistical analysis was performed using Review Manager Software 5.3. RESULTS After the databases search and cross-references of the bibliographies, seven studies were included in the present work. The funnel plot detected low risk of publication bias. The Coleman Methodology Score reported a good result, scoring 61.07 points. A total of 98 patients were enrolled, with 122 treated levels. All the patients underwent conservative therapies prior to injection. A remarkable improvement in the quality of life were reported after the treatment. The average Oswestry Disability Index (ODI) improved from "severe disability" to "minimal disability" at one year follow-up. The visual analogue scale (VAS) showed an improvement of ca. 30% at one year follow-up. Only one case of herniated nucleus pulposus was reported. No other adverse events at the aspiration or injection site were observed. CONCLUSIONS This systematic review of the literature proved MSC injection to be a safe and feasible option for intervertebral disc regeneration in the early-degeneration stage patients. Irrespective of the source of the MSCs, an overall clinical and radiological improvement of the patients has been evidenced, as indeed a very low complication rate during the follow-up.
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Affiliation(s)
- Filippo Migliorini
- Department of Orthopaedics, RWTH Aachen University Clinic, Pauwelsstraße 30, 52074, Aachen, Germany.
| | - Björn Rath
- Department of Orthopaedics, RWTH Aachen University Clinic, Pauwelsstraße 30, 52074, Aachen, Germany
| | - Markus Tingart
- Department of Orthopaedics, RWTH Aachen University Clinic, Pauwelsstraße 30, 52074, Aachen, Germany
| | - Alice Baroncini
- Department of Spine Surgery, Eifelklinik St. Brigida, Kammerbruchstraße 8, 52152, Simmerath, Germany
| | - Valentin Quack
- Department of Orthopaedics, RWTH Aachen University Clinic, Pauwelsstraße 30, 52074, Aachen, Germany
| | - Jörg Eschweiler
- Department of Orthopaedics, RWTH Aachen University Clinic, Pauwelsstraße 30, 52074, Aachen, Germany
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Disc cell therapy with bone-marrow-derived autologous mesenchymal stromal cells in a large porcine disc degeneration model. 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 2018; 27:2639-2649. [PMID: 30141058 DOI: 10.1007/s00586-018-5728-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 06/09/2018] [Accepted: 08/07/2018] [Indexed: 12/21/2022]
Abstract
PURPOSE Disc regeneration through matrix-assisted autologous mesenchymal stromal cell therapy seems promising against disc degeneration with convincing results in small animal models. Whether these positive results can be transferred to larger animal models or humans is unclear. METHODS Fibrin matrix-assisted autologous bone-marrow-derived mesenchymal stromal cell therapy was compared to acellular fibrin matrix therapy in a porcine in vivo model. First, disc degeneration was induced by annular puncture and partial nucleotomy with a large 16G-needle, and 12 weeks later, disc therapy was performed in a second surgery with a thinner 26G needle. Seventy-two lumbar discs from 12 aged adult pigs were evaluated by histology, micro-CT, and gene expression analysis 13 and 24 weeks after nucleotomy and 1 and 12 weeks after treatment, respectively. RESULTS Radiologic disc height was not significantly different in both treatment groups. In the semi-quantitative histologic degeneration score, significant disc degeneration was still evident 1 week after treatment both in the mesenchymal stromal cell group and in the acellular fibrin matrix group. 12 weeks after treatment, degeneration was, however, not further increased and mesenchymal-stromal-cell-treated discs showed significantly less disc degeneration in the annulus fibrosus (p = 0.02), whereas reduction in the nucleus pulposus did not reach statistical significance. Cell treatment compared to matrix alone found less Col1 gene expression as a marker for fibrosis and more expression of the trophic factor BMP2 in the nucleus pulposus, whereas the inflammation marker IL1ß was reduced in the annulus fibrosus. CONCLUSIONS Disc treatment with fibrin matrix-assisted autologous mesenchymal stromal cells reduced degenerative findings compared to acellular fibrin matrix alone. Regenerative changes, however, were not significant for all parameters showing limitations in a large biomechanically demanding model with aged discs. These slides can be retrieved under Electronic Supplementary Material.
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Chu G, Shi C, Wang H, Zhang W, Yang H, Li B. Strategies for Annulus Fibrosus Regeneration: From Biological Therapies to Tissue Engineering. Front Bioeng Biotechnol 2018; 6:90. [PMID: 30042942 PMCID: PMC6048238 DOI: 10.3389/fbioe.2018.00090] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 06/18/2018] [Indexed: 12/17/2022] Open
Abstract
Intervertebral disc (IVD) is an avascular tissue which contributes to the weight bearing, motion, and flexibility of spine. However, IVD is susceptible to damage and even failure due to injury, pathology, and aging. Annulus fibrosus (AF), the structural and functional integrity of which is critically essential to confine nucleus pulpous (NP) and maintain physiological intradiscal pressure under mechanical loading, plays a critical role in the biomechanical properties of IVD. AF degeneration commonly results in substantial deterioration of IVD. During this process, the biomechanical properties of AF and the balance between anabolism and catabolism in IVD are progressively disrupted, leading to chronic back pain, and even disability of individuals. Therefore, repairing and regenerating AF are effective treatments to degeneration-associated pains. However, they remain highly challenging due to the complexity of natural AF tissue in the aspects of cell phenotype, biochemical composition, microstructure, and mechanical properties. Tissue engineering (TE), by combining biological science and materials engineering, shed lights on AF regeneration. In this article, we review recent advances in the pro-anabolic approaches in the form of cell delivery, bioactive factors delivery, gene therapy, and TE strategies for achieving AF regeneration.
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Affiliation(s)
- Genglei Chu
- Orthopaedic Institute, Medical College, Soochow University, Suzhou, Jiangsu, China
- Department of Orthopaedic Surgery, First Affiliated Hospital, Soochow University, Suzhou, China
| | - Chen Shi
- Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore
| | - Huan Wang
- Orthopaedic Institute, Medical College, Soochow University, Suzhou, Jiangsu, China
- Department of Orthopaedic Surgery, First Affiliated Hospital, Soochow University, Suzhou, China
| | - Weidong Zhang
- Orthopaedic Institute, Medical College, Soochow University, Suzhou, Jiangsu, China
- Department of Orthopaedic Surgery, First Affiliated Hospital, Soochow University, Suzhou, China
| | - Huilin Yang
- Orthopaedic Institute, Medical College, Soochow University, Suzhou, Jiangsu, China
- Department of Orthopaedic Surgery, First Affiliated Hospital, Soochow University, Suzhou, China
| | - Bin Li
- Orthopaedic Institute, Medical College, Soochow University, Suzhou, Jiangsu, China
- Department of Orthopaedic Surgery, First Affiliated Hospital, Soochow University, Suzhou, China
- China Orthopaedic Regenerative Medicine Group, Hangzhou, China
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van den Akker GGH, Koenders MI, van de Loo FAJ, van Lent PLEM, Blaney Davidson E, van der Kraan PM. Transcriptional profiling distinguishes inner and outer annulus fibrosus from nucleus pulposus in the bovine intervertebral disc. 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 2017; 26:2053-2062. [PMID: 28567592 DOI: 10.1007/s00586-017-5150-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 05/11/2017] [Accepted: 05/18/2017] [Indexed: 12/20/2022]
Abstract
BACKGROUND Cells in the intervertebral disc have unique phenotypes and marker genes that separate the nucleus pulposus (NP), annulus fibrosus (AF) and articular cartilage (AC) have been identified. Recently, it was shown that phenotypic marker genes exhibit variable expression in humans. In this study, the bovine tail was used to determine the ability of marker genes to distinguish the outer and inner AF from NP tissue and isolated cells. METHODS Bovine tail intervertebral discs from 13 donors were dissected and correct isolation of tissue was confirmed. mRNA was isolated directly from tissue or passage 0 monolayer cells and used for gene expression measurements (qPCR). Conventional marker genes (bAcan, bCol1a1, bCol2a1) and novel marker genes (bAdamts17, bBrachyury/T, bCD24, bCol5a1, bCol12a1, bFoxf1, bKrt19, bPax1, bSfrp2) were evaluated. RESULTS As expected bAcan, bCol2a1 and bCol1a1 distinguished outer AF from NP tissue, while inner AF and NP could not be discriminated. The NP markers bT, bCd24 and bKrt19 were significantly higher expressed in NP than inner and outer AF tissue. bFoxF1 and bPax1 only distinguished IVD tissues from AC. The AF markers bAdamts17, bCol5a1, bCol12a1 and bSfrp2 were higher expressed in the outer AF compared with inner AF and NP tissue. Monolayer culturing strongly decreased bAcan, bCol2a1, bCD24 and bCol5a1 expression, while bCol1a1, bT, bKrt19 and bSfrp2 were not affected. CONCLUSION The IVD phenotypic marker genes bT, bKrt19, bSfrp2 and bCol12a1 convincingly distinguished NP from outer AF in situ and in vitro.
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Affiliation(s)
- Guus G H van den Akker
- Department of Rheumatology, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Marije I Koenders
- Department of Rheumatology, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Fons A J van de Loo
- Department of Rheumatology, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Peter L E M van Lent
- Department of Rheumatology, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Esmeralda Blaney Davidson
- Department of Rheumatology, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Peter M van der Kraan
- Department of Rheumatology, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands.
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