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Potential of bone marrow and umbilical cord derived mesenchymal stem cells in intervertebral disc repairLü, Fengjuan., 吕凤娟. January 2012 (has links)
Introduction: Intervertebral disc (IVD) degeneration is suggested to begin from the
nucleus pulposus (NP). Evidence from various studies highlights mesenchymal stem cells
(MSC), in most cases using bone marrow derived MSC, as a potential stem cell source
for NP regeneration. However MSC can be isolated from many sources with various
characteristics. There are indications that fetal or close to fetal tissue sources contain
MSC with relatively undifferentiated phenotype with respect to MSC from adult sources.
Moreover, umbilical cord (C)-MSC may have better chondrogenic differentiation potential
than bone marrow (B)-MSC. We hypothesize CMSC are different from BMSC, and more
efficient than BMSC in stimulating NP regeneration.
Methods: MSC were isolated from human bone marrow and umbilical cord with
corresponding ethical approval. BMSC and CMSC were characterized for cell surface
marker expression profile and differentiation potential.. RT-PCR of interest genes in NP
cells isolated from scoliosis and degenerate discs was performed to search for NP
degeneration indicators. Conditioned media (CM) was collected from confluent MSC
monolayer, and used for stimulation of four batches of degenerated NP cells isolated from
human degenerative intervertebral discs. Cell proliferation and cytotoxicity were assessed
by MTT assay. Proteoglycan content were measured by DMMB assay. Gene expression
of a series of degeneration related molecules including ACAN, SOX9, CDH2, CD55,
KRT19, KRT18, FBLN1 and MGP, and fibrosis related molecules, including MMP12,
HSP47, COL1A1, COL3A1 and FN1, of NP cells in MSC-CM were determined by real- time RT-PCR. All results were normalized to the control cells in basal medium. The
expression of discogenic, chondrogenic and osteogenic markers on BMSC and CMSC
were compared by RT-PCR.
Results and Conclusion: CMSC were similar to BMSC and fulfilled the minimum
criteria of MSC, however the expression of CD146, CD106 and Stro-1 was different, and
BMSC had a spontaneous osteogenesis tendency while CMSC expressed chondrogenic
marker even without TGF-beta stimulation. BMSC demonstrated a paracrine effect on
modulating human degenerated NP cells towards a non-degenerative phenotype in
stimulating cell proliferation, slightly enhancing proteoglycan production, upregulating
KRT19 while downregulating MMP12. Compared with BMSC, a higher paracrine effect of
CMSC was disclosed in modulating the phenotype of NP cells in all aspects tested, and
an intrinsic higher expression on CMSC of ‘potential NP markers’, including KRT19,
KRT18 and CD55, but lower expression of osteogenic markers, including RUNX2 and
ALPL, was revealed, which indicate a higher potential of CMSC for future clinical
application to treat IVD degeneration diseases. KRT19 and MMP12 were also confirmed
to be the highest differentially expressed candidate genes between cultured scoliosis and
degenerated human NP cells, indicating a high indicator potential of NP degeneration.
Furthermore, a subpopulation was detected in the degenerated NP cells that possessed
macrophage-like phenotype and activities, which may play a role in the pathogenesis of
IVD degeneration. In conclusion, studies in this thesis highlighted CMSC as a superior
source than BMSC for IVD repair. Further investigations into the active agents in the
conditioned media and the signalling pathway may help to elucidate the mechanism of
the effect. / published_or_final_version / Orthopaedics and Traumatology / Doctoral / Doctor of Philosophy
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Fabrication of multi-component tissue for intervertebral disc tissue engineeringChik, Tsz-kit., 戚子傑. January 2012 (has links)
Intervertebral disc tissue engineering is challenging because it involves the
integration of multiple tissues with distinct structures and compositions such as
lamellar annulus fibrosus, gel?like nucleus pulposus and cartilage endplate. Each
of them has different compositions and different structures. It is hypothesized
that integration of tissues can be enhanced with appropriate mechanical and
biological stimuli. Meanwhile, effect of torsional stimulus on cell re?orientation
in mesenchymal stem cell?collagen tubular constructs is investigated in this study.
Furthermore, it is proposed that these findings can be used to fabricate a multicomponent
unit for intervertebral disc tissue engineering. It has been
demonstrated that mechanical and biological stimuli can stabilize the interface
between osteogenic and chondrogenic differentiated constructs with enhanced
ultimate tensile stress while the phenotype of osteogenic and chondrogenic
differentiated constructs were maintained. Scanning electronic microscopic
images have shown aligned collagen fibrils and presence of calcium at the
interface, indicating the possibility of the formation of a calcified zone. In
addition, it is proven that torsional stimulus triggered re?orientation of
mesenchymal stem cells in collagen lamellae towards a preferred angle. Cell
alignments were confirmed by using a MatLab?based program to analyze the
actin filament and the cell alignment via Phalloidin and Hematoxylin staining,
respectively. Cells and actin filaments were inclined around 30o from the vertical
axis, while cells and filaments in the control group (static loading) aligned along
the vertical axis. Furthermore, a double?layers bioengineered unit was fabricated,
with intact osteogenic differentiated parts at both ends. Comparatively higher
cell density was observed at the interface between layers, demonstrating the
interactions between layers, while the phenotype of each part was maintained in
14 days culture. This study concludes that a multi?components bioengineered
unit with preferred cell alignments can be fabricated. This provides new insights
to future development of bioengineered spinal motion segment for treating late
stage disc degeneration. / published_or_final_version / Mechanical Engineering / Doctoral / Doctor of Philosophy
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Differential action of bone morphogenetic protein BMP-2 and BMP-7 on nucleus pulposus cells of intervertebral discZhou, Lixiong, 周立雄 January 2014 (has links)
Low back pain (LBP) is associated with intervertebral disc (IVD) degeneration and exerts enormous socioeconomic burdens on the society. The nucleus pulposus (NP) is the structural and functional core of the IVD, and plays vital roles in its homeostasis. Although the etiology of IVD degeneration is not fully understood, the cellular changes of the NP have been proposed to be associated with degeneration. Conventional management for IVD degeneration primarily targets to relieve LBP and other symptoms without restoring or preserving disc function. Novel therapeutic strategies have emerged with an aim to retard or even reverse disc degeneration. In particular, the use of growth factors, such as the bone morphogenetic proteins (BMP), has received considerable attention due to their anabolic effects on extracellular matrix (ECM) synthesis by NP cells.
BMP-2 and BMP-7 are of great interest for their involvement in osteogenesis, chondrogenesis, and development and maintenance of the IVD. To date, the benefits of BMP-2 on disc degeneration are controversial, given the inconsistent findings from animal model studies. The effectiveness of BMP-7 in disc repair, however, has been well demonstrated both in vitro and in vivo. A better understanding of the differences between BMP-2 and BMP-7 regulatory action on NP cells may facilitate future applications of BMP in disc repair/regeneration.
This study hypothesized that BMP-2 and BMP-7 act differentially on human NP cells via different signal transduction processes. The differential effect of BMP-2 and BMP-7 was first tested in bovine NP cells using a three-dimensional culture system (alginate beads). Both BMP-2 and BMP-7 enhanced ECM production and phenotypic characteristics of bovine NP cells. Notably, BMP-7 was significantly more potent than BMP-2 in this regard. The effects of BMPs were further tested on non-degenerated (ND-NP) and degenerated (D-NP) human NP cells. The DMMB assay revealed that BMP-7 exerted a superior up-regulatory action on GAG production of D-NP cells compared to BMP-2. Furthermore, the overall response of D-NP cells to BMP-2 and BMP-7 was significantly lower than ND-NP cells.
Immunohistochemical staining and quantitative RT-PCR assays demonstrated that D-NP cells possess a more fibroblastic and less chondrocyte-like phenotype than ND-NP cells. At the mRNA level, the BMP receptor BMPR1A was not expressed in D-NP cells. BMP-7, but not BMP-2, induced expression of BMPR1A in D-NP cells. On the other hand, gene expression of selected TGF-β pathway components and hypoxia pathway components were significantly up-regulated by BMP-2 but down-regulated by BMP-7. These findings suggest that D-NP cells can activate differential molecular cascades in response to BMP-2 and BMP-7.
In conclusion, this study showed a superior effect of BMP7 in up-regulation of classical BMP signaling components including BMP receptor BMPR1A. The reduced responsiveness of D-NP cells to BMP-2 and BMP-7 stimulation may be related to a different expression pattern of BMP receptors. This study provides insights into the differential regulatory actions of BMP-2 and BMP-7 on human NP cells and facilitates the future application of BMPs in managing disc degeneration. / published_or_final_version / Orthopaedics and Traumatology / Doctoral / Doctor of Philosophy
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Development and characterization of a prosthetic intervertebral discHudgins, Robert Garryl 12 1900 (has links)
No description available.
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Discitis after discography and chemonucleolysis /Fraser, Robert D. January 1986 (has links) (PDF)
Thesis (M.D.)--University of Adelaide, 1989. / Includes bibliographical references (leaves 107-109).
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In vivo study of asporin polymorphic variants in chondrogenesis and degenerative disc disease (DDD)Lam, To-kam. January 2009 (has links)
Thesis (M. Phil.)--University of Hong Kong, 2009. / Includes bibliographical references (leaves 154-162). Also available in print.
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Mechanisms of axial compressive fracture in human lumbar spine /Ochia, Ruth Shada. January 2000 (has links)
Thesis (Ph. D.)--University of Washington, 2000. / Vita. Includes bibliographical references (leaves 96-103).
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Finite element analysis and materials characterization of changes due to aging and degeneration of the human intervertebral disc /Massey, Christopher John. Marcolongo, Michele S. January 2009 (has links)
Thesis (Ph.D.)--Drexel University, 2009. / Includes abstract and vita. Includes bibliographical references (leaves 145-161).
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Development of injectable hydrogels for nucleus pulposus replacement /Thomas, Jonathan D. Lowman, Anthony M. Marcolongo, Michele S. January 2006 (has links)
Thesis (Ph. D.)--Drexel University, 2006. / Includes abstract and vita. Includes bibliographical references (leaves 170-193).
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Serial radiographic and histological changes as a result of a disc curettage in chondrodystrophic caninesWagner, Stanley D. January 1985 (has links)
Call number: LD2668 .T4 1985 W33 / Master of Science
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