Compartmentalization of the matrix formed by nucleus pulposus and annulus fibrosus cells in alginate gel

2002 ◽  
Vol 30 (6) ◽  
pp. 874-878 ◽  
Author(s):  
E. Thonar ◽  
H. An ◽  
K. Masuda
Keyword(s):  
Nucleus Pulposus ◽  
Annulus Fibrosus ◽  
Articular Chondrocyte ◽  
Alginate Gel ◽  
Age Related ◽  
The Matrix ◽  
Disc Cells ◽  
A Cell ◽  
Associated Matrix

Intervertebral disc cells cultured in alginate gel are capable of reforming in alginate, a matrix that consists of two compartments: a rim of metabolically active cell-associated matrix and a more abundant, but metabolically less active, further removed matrix. At any one age and in most species, the cell-associated matrix formed by a nucleus pulposus or annulus fibrosus cell cultured in this way is less abundant than that formed by an articular chondrocyte. In both the cell-associated matrix and further removed matrix, the ratio of aggrecan to collagen is significantly higher in the case of nucleus pulposus than of annulus fibrosus, a feature that also distinguishes the matrices of the nucleus pulposus and annulus fibrosus in vivo. Nucleus pulposus and annulus fibrosus cells from older donors show a decreased ability to reform a cell-associated matrix rich in aggrecan. There is, however, some evidence that gene therapy and/or exposure of the cells to defined stimulatory factors can help overcome some of these age-related limitations. This contention is supported by recent evidence that nucleus pulposus and annulus fibrosus cells from adult donors can be manipulated to form, using the recently developed alginate-recovered chondrocyte system, a resilient tissue that bears many of the characteristics of the tissue in which these cells reside in vivo.

scholarly journals Aggrecan degradation in human intervertebral disc and articular cartilage

1997 ◽  
Vol 326 (1) ◽  
pp. 235-241 ◽  
Author(s):  
Robert SZTROLOVICS ◽  
Mauro ALINI ◽  
Peter J. ROUGHLEY ◽  
John S. MORT
Keyword(s):  
Articular Cartilage ◽  
Intervertebral Disc ◽  
Nucleus Pulposus ◽  
Degradation Product ◽  
Annulus Fibrosus ◽  
Degradation Products ◽  
Immunoblot Analysis ◽  
Age Related ◽  
Low Levels

Aggrecan degradation in human intervertebral disc and articular cartilage has been studied by using anti-neoepitope antibodies specific for the N-terminal degradation products generated by cleavage within the interglobular domain at the metalloproteinase and aggrecanase sites. Immunoblot analysis of extracts of annulus fibrosus, nucleus pulposus and articular cartilage demonstrated age-related patterns in the abundance of both degradation products. In all three tissues the metalloproteinase-generated fragment was present at very low levels in young individuals but increased in abundance with age. In the disc tissues, the abundance of this degradation product levelled off in the juvenile; for cartilage this occurred in early adulthood. Despite these temporal differences, the levels attained in adults were comparable for the three tissues. In contrast, the aggrecanase-generated degradation product exhibited tissue-specific differences in the variation of its abundance with age. Whereas this degradation product increased with age in annulus fibrosus and articular cartilage and had levelled off by adulthood, in nucleus pulposus it was present in greatest abundance in young individuals and decreased to very low levels with age. Examination of discs exhibiting various degrees of degeneration did not reveal any differences in the levels of the metalloproteinase and aggrecanase-generated cleavage products that could not be accounted for by differences in age. In adults the product of aggrecanase action was much more abundant in articular cartilage than in either of the disc tissues, despite the age-related increase also observed for annulus fibrosus. Analysis of tissue extracts with an antibody recognizing the G1 domain of aggrecan identified two major degradation products whose abundance and size were correlated with the fragments detected by the anti-neoepitope antibodies. Taken together, these results indicate that cleavage at the metalloproteinase and aggrecanase sites are quantitatively important events in aggrecan catabolism in both articular cartilage and intervertebral disc in vivo. Moreover the two enzyme systems act independently and exhibit differences in the degree to which they contribute to aggrecan degradation in these tissues.

scholarly journals Evaluation of apoptotic cell death in normal and chondrodystrophic canine intervertebral discs

2012 ◽  
Vol 2 (1) ◽  
pp. 6 ◽  
Author(s):  
Marie Klauser ◽  
Franck Forterre ◽  
Marcus Doherr ◽  
Andreas Zurbriggen ◽  
David Spreng ◽  
...  
Keyword(s):  
Nucleus Pulposus ◽  
Disc Degeneration ◽  
Annulus Fibrosus ◽  
Caspase 3 ◽  
Apoptotic Cell ◽  
Intervertebral Discs ◽  
Discogenic Pain ◽  
Age Related ◽  
Chondroid Metaplasia ◽  
Related Increase

Disc degeneration occurs commonly in dogs. A variety of factors is thought to contribute an inappropriate disc matrix that isolate cells in the disc and lead to apoptosis. Disc herniation with radiculopathy and discogenic pain are the results of the degenerative process. The objective of this prospective study was to determine the extent of apoptosis in intact and herniated intervertebral discs of chondrodystrophic dogs and non-chondrodystrophic dogs. In addition, the nucleus pulposus (NP) was histologically compared between non-chondrodystrophic and chondrodystrophic dogs. Thoracolumbar intervertebral discs and parts of the extruded nucleus pulposus were harvested from 45 dogs. Samples were subsequently stained with haematoxylin-eosin and processed to detect cleaved caspase-3 and poly(ADP-ribose) polymerase. A significant greater degree of apoptosis was observed in herniated NPs of chondrodystrophic dogs compared to non- chondrodystrophic dogs with poly (ADP-ribose) polymerase and cleaved caspase- 3 detection. Within the group of chondrodystrophic dogs, dogs with an intact disc and younger than 6 years showed a significant lower incidence of apoptosis in the NP compared to the herniated NP of chondrodystrophic dogs. The extent of apoptosis in the annulus fibrosus was not different between the intact disc from chondrodystrophic and non- chondrodystrophic dogs. An age-related increase of apoptotic cells in NP and annulus fibrosus was found in the intact non-herniated intervertebral discs. Histologically, absence of notochordal cells and occurrence of chondroid metaplasia were observed in the nucleus pulposus of chondrodystrophic dogs. As a result, we found that apoptosis plays a role in disc degeneration in chondrodystrophic dogs.

Mesenchymal Stem Cell-Seeded High-Density Collagen Gel for Annular Repair: 6-Week Results From In Vivo Sheep Models

Neurosurgery ◽  
2018 ◽  
Vol 85 (2) ◽  
pp. E350-E359 ◽  
Author(s):  
Ibrahim Hussain ◽  
Stephen R Sloan ◽  
Christoph Wipplinger ◽  
Rodrigo Navarro-Ramirez ◽  
Micaella Zubkov ◽  
...  
Keyword(s):  
Nucleus Pulposus ◽  
Annulus Fibrosus ◽  
Perioperative Complications ◽  
Collagen Gel ◽  
Intervertebral Discs ◽  
High Density ◽  
Sheep Model ◽  
Gel Treatment ◽  
Pfirrmann Grade

AbstractBACKGROUNDOur group has previously demonstrated in vivo annulus fibrosus repair in animal models using an acellular, riboflavin crosslinked, high-density collagen (HDC) gel.OBJECTIVETo assess if seeding allogenic mesenchymal stem cells (MSCs) into this gel yields improved histological and radiographic benefits in an in vivo sheep model of annular injury.METHODSFifteen lumbar intervertebral discs (IVDs) were randomized into 4 groups: intact, injury only, injury + acellular gel treatment, or injury + MSC-seeded gel treatment. Sheep were sacrificed at 6 wk. Disc height index (DHI), Pfirrmann grade, nucleus pulposus area, and T2 relaxation time (T2-RT) were calculated for each IVD and standardized to healthy controls from the same sheep. Quantitative histological assessment was also performed using the Han scoring system.RESULTSAll treated IVDs retained gel plugs on gross assessment and there were no adverse perioperative complications. The MSC-seeded gel treatment group demonstrated statistically significant improvement over other experimental groups in DHI (P = .002), Pfirrmann grade (P < .001), and T2-RT (P = .015). There was a trend for greater Han scores in the MSC-seeded gel-treated discs compared with injury only and acellular gel-treated IVDs (P = .246).CONCLUSIONMSC-seeded HDC gel can be delivered into injured IVDs and maintained safely in live sheep to 6 wk. Compared with no treatment and acellular HDC gel, our data show that MSC-seeded HDC gel improves outcomes in DHI, Pfirrmann grade, and T2-RT. Histological analysis shows improved annulus fibrosus and nucleus pulposus reconstitution and organization over other experimental groups as well.

scholarly journals Combined Nucleus Pulposus Augmentation and Annulus Fibrosus Repair Prevents Intervertebral Disc Degeneration After Discectomy

Neurosurgery ◽  
2019 ◽  
Vol 66 (Supplement_1) ◽  
Author(s):  
Sertac Kirnaz ◽  
Stephen Sloan ◽  
Christoph Wipplinger ◽  
Franziska Anna Schmidt ◽  
Roger Hartl ◽  
...  
Keyword(s):  
Nucleus Pulposus ◽  
Disc Degeneration ◽  
Annulus Fibrosus ◽  
Combined Treatment ◽  
Disc Height ◽  
Histological Evaluation ◽  
Sheep Model ◽  
Mri Scans ◽  
The Individual

Abstract INTRODUCTION The objective of the current study is to assess the efficacy of combined annulus fibrosus (AF) using a high-density collagen (HDC) gel and nucleus pulposus (NP) repair using a hyaluronic acid (HA) gel in an in Vivo sheep model. METHODS We performed an anterolateral, retroperitoneal prepsoas approach to access the IVDs L1-6 in a total of 8 skeletally mature Finn sheep. IVDs were randomized into 5 groups: (1) intact, (2) injured via 3 × 10 mm box annulotomy and removal of 200 mg of NP, (3) injury and HDC gel patch for AF repair, (4) injury and injection of a HA gel into the NP, and (5) injury and HDC AF repair and NP HA replacement. At 6 wk postoperatively, sheep were sacrificed and underwent postmortem 3T-MRI scans as well as gross anatomical and histological evaluation. Disc height index (DHI) analysis and Pfirrmann grading (PG) were performed on each segment using MR images. RESULTS Intact control discs were not degenerated and had an average PG of 1 while injured, and untreated discs had a significant degeneration with an average PG of 3. Discs receiving the combined injection and collagen AF patch individually showed fewer signs of degeneration than injured alone, and the combined treatment resulted in the least amount of degeneration with PG not significantly different from the intact controls. DHI confirmed the trends seen in the PG, where injured discs lost 20% of the intact disc height, the individual NP and AF repairs restored 5% to 10% of intact disc height, and the combined repairs preserved 90% of the intact disc height. CONCLUSION PG and DHI results demonstrate that individual NP and AF repairs are able to prevent disc degeneration better than no treatment at all; however, the greatest preservation of disc health was seen with combined AF and NP repairs.

Biaxial Mechanical Testing of Single Annulus Fibrosus Layers

2010 ◽  
Author(s):  
J. P. Rys ◽  
A. M. Ellingson ◽  
D. J. Nuckley ◽  
V. H. Barocas
Keyword(s):  
Intervertebral Disc ◽  
Annulus Fibrosus ◽  
Spinal Nerve ◽  
Older Individuals ◽  
Physical Trauma ◽  
Age Related ◽  
Biaxial Mechanical Testing ◽  
Partial Displacement ◽  
Outer Annulus Fibrosus

The intervertebral disc (IVD), consisting of the inner nucleus pulposus and the outer annulus fibrosus, is subjected to multiaxial stress in vivo. The disc undergoes degenerative changes that account for impairment and disability in middle-aged and older individuals.4 In addition to age-related degeneration, the intervertebral disc is subject to the development of lesions due to partial displacement or rupture of the annulus fibrosus. Such occurrences, typically resulting from physical trauma, can yield disabling effects from impingement on spinal nerve structures. A greater understanding of the IVD and how it functions mechanically is crucial in prevention and repair of debilitating spinal disorders.

scholarly journals Hyaline cartilage differentiation of fibroblasts in regeneration and regenerative medicine

Development ◽  
2022 ◽  
Author(s):  
Ling Yu ◽  
Yu-Lieh Lin ◽  
Mingquan Yan ◽  
Tao Li ◽  
Emily Y. Wu ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Regenerative Medicine ◽  
Hyaline Cartilage ◽  
Fibroblast Cell ◽  
Similar Response ◽  
Articular Chondrocyte ◽  
Joint Injury ◽  
A Cell ◽  
Culture Strategy

Amputation injuries in mammals are typically non-regenerative, however joint regeneration is stimulated by BMP9 treatment (Yu et al., 2019) indicating the presence of latent articular chondrocyte progenitor cells. BMP9 induces a battery of chondrogenic genes in vivo, and a similar response is observed in cultures of amputation wound cells. Extended cultures of BMP9 treated cells results in differentiation of hyaline cartilage and single cell RNAseq analysis identified wound fibroblasts as BMP9 responsive. This culture model was used to identify a BMP9 responsive adult fibroblast cell line and a culture strategy was developed to engineer hyaline cartilage for engraftment into an acutely damaged joint. Transplanted hyaline cartilage survived engraftment and maintained a hyaline cartilage phenotype but did not form mature articular cartilage. In addition, individual hypertrophic chondrocytes were identified in some samples indicating that the acute joint injury site can promote osteogenic progression of engrafted hyaline cartilage. The findings identify fibroblasts as a cell source for engineering articular cartilage and establishes a novel experimental strategy that bridges the gap between regeneration biology and regenerative medicine.

Effect of Inflammation on the Osmotic Response of Nucleus Pulposus Cells

2012 ◽  
Author(s):  
Robert Maidhof ◽  
Neena Rajan ◽  
Nadeen O. Chahine
Keyword(s):  
Nucleus Pulposus ◽  
Biomechanical Properties ◽  
Nucleus Pulposus Cells ◽  
Cellular Mechanisms ◽  
Osmotic Response ◽  
Tnf Α ◽  
Disc Cells ◽  
Cytokine Stimulation ◽  
Ivd Degeneration

Intervertebral disc (IVD) degeneration is accompanied by elevated levels of pro-inflammatory cytokines, particularly IL-1β and TNF-α [1]. Disc cells from the nucleus pulposus (NPs) respond to cytokine stimulation with increased catabolic breakdown of the tissue, resulting in a positive feedback of disc integrity loss and further inflammation [2]. Previous studies by our group have examined the response of NP cells to Toll-Like Receptor-4 (TLR-4) activation through stimulation with lipopolysaccharide (LPS). TLR-4 is a pattern recognition receptor that is activated in innate immunity and by polysaccharide fragments from degenerated proteoglycans. TLR-4 activation by LPS results in stimulation of multiple cytokines by NP cells [3]. Moreover, we have shown that in vivo LPS injection results in catabolic changes in the IVD, including matrix breakdown, decrease in biomechanical properties and loss of disc height [4]. However, the specific cellular mechanisms for these catabolic changes remain to be elucidated.

scholarly journals Metalloproteinases in Ovarian Cancer

2021 ◽  
Vol 22 (7) ◽  
pp. 3403
Author(s):  
Preston Carey ◽  
Ethan Low ◽  
Elizabeth Harper ◽  
M. Sharon Stack
Keyword(s):  
Ovarian Cancer ◽  
Extracellular Matrix ◽  
Tumor Microenvironment ◽  
Cancer Progression ◽  
Ovarian Cancer Cells ◽  
Age Related ◽  
The Matrix ◽  
Interaction Stress

Proteases play a crucial role in the progression and metastasis of ovarian cancer. Pericellular protein degradation and fragmentation along with remodeling of the extracellular matrix (ECM) is accomplished by numerous proteases that are present in the ovarian tumor microenvironment. Several proteolytic processes have been linked to cancer progression, particularly those facilitated by the matrix metalloproteinase (MMP) family. These proteases have been linked to enhanced migratory ability, extracellular matrix breakdown, and development of support systems for tumors. Several studies have reported the direct involvement of MMPs with ovarian cancer, as well as their mechanisms of action in the tumor microenvironment. MMPs play a key role in upregulating transcription factors, as well as the breakdown of structural proteins like collagen. Proteolytic mechanisms have been shown to enhance the ability of ovarian cancer cells to migrate and adhere to secondary sites allowing for efficient metastasis. Furthermore, angiogenesis for tumor growth and development of metastatic implants is influenced by upregulation of certain proteases, including MMPs. While proteases are produced normally in vivo, they can be upregulated by cancer-associated mutations, tumor–microenvironment interaction, stress-induced catecholamine production, and age-related pathologies. This review outlines the important role of proteases throughout ovarian cancer progression and metastasis.

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