scholarly journals Intervertebral disc decellularisation: progress and challenges

2021 ◽  
Vol 42 ◽  
pp. 196-219
Author(s):  
MF Fiordalisi ◽  
◽  
AJ Silva ◽  
M Barbosa ◽  
RM Gonçalves ◽  
...  
Keyword(s):  
Intervertebral Disc ◽  
Life Quality ◽  
Cell Types ◽  
Host Cells ◽  
Low Back ◽  
Therapeutic Success ◽  
A Cell ◽  
Antigen Removal ◽  
Ivd Degeneration ◽  
Different Cell Types

Intervertebral disc (IVD) degeneration and the consequent low-back pain (LBP) affect over 80 % of people in western societies, constituting a tremendous socio-economic burden worldwide and largely impairing patients’ life quality. Extracellular matrix (ECM)-based scaffolds, derived from decellularised tissues, are being increasingly explored in regenerative medicine for tissue repair. Decellularisation plays an essential role for host cells and antigen removal, while maintaining native microenvironmental signals, including ECM structure, composition and mechanical properties, which are essential for driving tissue regeneration. With the lack of clinical solutions for IVD repair/regeneration, implantation of decellularised IVD tissues has been explored to halt and/or revert the degenerative cascade and the associated LBP symptoms. Over the last few years, several researchers have focused on the optimisation of IVD decellularisation methods, combining physical, chemical and enzymatic treatments, in order to successfully develop a cell-free matrix. Recellularisation of IVD-based scaffolds with different cell types has been attempted and numerous methods have been explored to address proper IVD regeneration. Herein, the advances in IVD decellularisation methods, sterilisation procedures, repopulation and biocompatibility tests are reviewed. Additionally, the importance of the donor profile for therapeutic success is also addressed. Finally, the perspectives and major hurdles for clinical use of the decellularised ECM-based biomaterials for IVD are discussed. The studies reviewed support the notion that tissue-engineering-based strategies resorting to decellularised IVD may represent a major advancement in the treatment of disc degeneration and consequent LBP.

The Biology of Viruses

2019 ◽  
Author(s):  
Anna Jeffery-Smith ◽  
C. Y. William Tong
Keyword(s):  
Nucleic Acid ◽  
Host Cell ◽  
Genetic Material ◽  
Cell Types ◽  
Host Cells ◽  
Host Cell Membrane ◽  
Cell Receptors ◽  
A Cell ◽  
Independent Synthesis ◽  
Different Cell Types

In order to be classified as a virus, certain criteria have to be fulfilled. Viruses must ● Be only capable of growth and multiplication within living cells, i.e. obligate intracellular parasite. Host cells could include humans, animals, insects, plants, protozoa, or even bacteria. ● Have a nucleic acid genome (either RNA or DNA, but not both) surrounded by a protein coat (capsid). ● Have no semipermeable membrane, though some have an envelope formed of phospholipids and proteins. ● Be inert outside of the host cell. Enveloped viruses are susceptible to inactivation by organic solvents such as alcohol. ● Perform replication by independent synthesis of components followed by assembly (c.f. binary fission in bacteria). Viruses are considered as a bundle of genetic programmes encoded in nucleic acids and packaged with a capsid +/ - envelope protein, which can be activated on entry into a host cell (compare this with computer viruses packaged in an enticing way in order to infect and take over control of your PC). Although they share some similarities in their properties, mycoplasma and chlamydia are true bacteria. The virion (assembled infectious particle) consists of viral nucleic acid and capsid. The nucleic acid of a virus can either be ribonucleic acid (RNA) or deoxyribonucleic acid (DNA), and the amount of genetic material varies widely, with some viruses able to encode a few proteins and others having genetic material that encodes hundreds of proteins. In association with the nucleic acid there may be non- structural viral proteins, such as a viral polymerase. The nucleic acid and non- structural proteins are protected by a surrounding layer of capsid proteins. The capsid includes proteins which can attach to host cell receptors. The proteins and the cell receptors to which they bind determine a virus’ tropism, i.e., the ability to bind to and enter different cell types. The term nucleocapsid refers to the nucleic acid core surrounded by capsid protein. Some viruses also have an envelope made up of phospholipids and proteins surrounding the nucleocapsid. This envelope can be formed by the host cell membrane during the process of a virus budding from a cell during replication.

scholarly journals Influence of Angiopoietin Treatment with Hypoxia and Normoxia on Human Intervertebral Disc Progenitor Cell’s Proliferation, Metabolic Activity, and Phenotype

2021 ◽  
Vol 11 (15) ◽  
pp. 7144
Author(s):  
Muriel C. Bischof ◽  
Sonja Häckel ◽  
Andrea Oberli ◽  
Andreas S. Croft ◽  
Katharina A. C. Oswald ◽  
...  
Keyword(s):  
Gene Expression ◽  
Intervertebral Disc ◽  
Metabolic Activity ◽  
Cell Metabolism ◽  
Trauma Patients ◽  
Low Back ◽  
Relative Gene Expression ◽  
Progenitor Cell Population ◽  
Ivd Degeneration ◽  
Relative Gene

Increasing evidence implicates intervertebral disc (IVD) degeneration as a major contributor to low back pain. In addition to a series of pathogenic processes, degenerated IVDs become vascularized in contrast to healthy IVDs. In this context, angiopoietin (Ang) plays a crucial role and is involved in cytokine recruitment, and anabolic and catabolic reactions within the extracellular matrix (ECM). Over the last decade, a progenitor cell population has been described in the nucleus pulposus (NP) of the IVD to be positive for the Tie2 marker (also known as Ang-1 receptor). In this study, we investigated the influence of Ang-1 and Ang-2 on human NP cell (Tie2+, Tie2- or mixed) populations isolated from trauma patients during 7 days in normoxia (21% O2) or hypoxia (≤ 5% O2). At the end of the process, the proliferation and metabolic activity of the NP cells were analyzed. Additionally, the relative gene expression of NP-related markers was evaluated. NP cells showed a higher proliferation depending on the Ang treatment. Moreover, the study revealed higher NP cell metabolism when cultured in hypoxia. Additionally, the relative gene expression followed, with an increase linked to the oxygen level and Ang concentration. Our study comparing different NP cell populations may be the start of new approaches for the treatment of IVD degeneration.

scholarly journals Reactive Oxygen Species Mediate Low Back Pain by Upregulating Substance P in Intervertebral Disc Degeneration

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Jiancheng Zheng ◽  
Jian Zhang ◽  
Xingkai Zhang ◽  
Zhiping Guo ◽  
Wenjian Wu ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Low Back Pain ◽  
Back Pain ◽  
Substance P ◽  
Intervertebral Disc ◽  
Reactive Oxygen ◽  
Alternative Methods ◽  
Low Back ◽  
Oxygen Species ◽  
Ivd Degeneration

Reactive oxygen species (ROS) are thought to have a strong correlation with a number of intervertebral disc (IVD) diseases. Here, we aimed to determine whether ROS represent an etiology of low back pain (LBP) during IVD degeneration. Thirty degenerated intervertebral disc samples were obtained from patients, and ROS levels were quantified using dihydroethidium (DHE) staining. The results suggested a significant correlation between the ROS level and the severity of LBP. Subsequently, a puncture-induced LBP model was established in rats, and ROS levels significantly increased compared with those in the sham surgery group, accompanied with severe puncture-induced IVD degeneration. In addition, when ROS levels were increased by H2O2 administration or decreased by NAC treatment, the rats showed increased or decreased LBP, respectively. Based on this evidence, we further determined that stimulation with H2O2 in nucleus pulposus cells (NPCs) in vivo or in vitro resulted in upregulation of substance P (SP), a peptide thought to be involved in the synaptic transmission of pain, and that the severity of LBP decreased when SP levels were increased by exogenous SP administration or neutralized via aprepitant treatment in the IVDs of rats. In conclusion, ROS are primary inducers of LBP based on clinical and animal data, and the mechanism involves ROS stimulation of NPCs to secrete SP, which is a critical neurotransmitter peptide, to promote LBP in IVDs. Therefore, reducing the level of ROS with specific drugs and inhibiting SP may be alternative methods to treat LBP in the clinic.

Mechanical Consequence of Induced Intervertebral Disc Degeneration in the SPARC-Null Mouse

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Mitchel C. Whittal ◽  
Sara Molladavoodi ◽  
Derek P. Zwambag ◽  
Magali Millecamps ◽  
Laura S. Stone ◽  
...  
Keyword(s):  
Low Back Pain ◽  
Back Pain ◽  
Intervertebral Disc ◽  
Mechanical Tests ◽  
Null Mouse ◽  
Low Back ◽  
Spine Mechanics ◽  
Tension And Compression ◽  
In Series ◽  
Ivd Degeneration

Abstract Intervertebral disc (IVD) degeneration is associated with low back pain (LBP) and accompanied by mechanical changes to the spine. Secreted protein acidic and rich in cysteine (SPARC) is a protein that contributes to the functioning and maintenance of the extracellular matrix. SPARC-null mice display accelerated IVD degeneration and pain-associated behaviors. This study examined if SPARC-null mice also display altered spine mechanics as compared to wild-type (WT) mice. Lumbar spines from SPARC-null (n = 36) and WT (n = 18) mice aged 14–25 months were subjected to cyclic axial tension and compression to determine neutral zone (NZ) length and stiffness. Three separate mechanical tests were completed for each spine to determine the effect of the number of IVDs tested in series (one versus two versus three IVDs). SPARC-null spine NZs were both stiffer (p < 0.001) and smaller in length (p < 0.001) than WT spines. There was an effect of the number of IVDs tested in series for NZ length but not NZ stiffness when collapsed across condition (SPARC-null and WT). Correlation analysis revealed a weak negative correlation (r = −0.24) between age and NZ length in SPARC-null mice and a weak positive correlation (r = 0.30) between age and NZ stiffness in WT mice. In conclusion, SPARC-null mice had stiffer and smaller NZs than WT mice, regardless of the number of IVDs in series being tested. The increased stiffness of these IVDs likely influences mobility at these spinal joints thereby potentially contributing to low back pain.

scholarly journals The complement of desmosomal plaque proteins in different cell types.

1985 ◽  
Vol 101 (4) ◽  
pp. 1442-1454 ◽  
Author(s):  
P Cowin ◽  
H P Kapprell ◽  
W W Franke
Keyword(s):  
Guinea Pig ◽  
Cell Types ◽  
Cardiac Cells ◽  
Myocardial Tissue ◽  
Cell Type ◽  
Wide Range ◽  
Specific Manner ◽  
A Cell ◽  
Cell Type Specific ◽  
Different Cell Types

Desmosomal plaque proteins have been identified in immunoblotting and immunolocalization experiments on a wide range of cell types from several species, using a panel of monoclonal murine antibodies to desmoplakins I and II and a guinea pig antiserum to desmosomal band 5 protein. Specifically, we have taken advantage of the fact that certain antibodies react with both desmoplakins I and II, whereas others react only with desmoplakin I, indicating that desmoplakin I contains unique regions not present on the closely related desmoplakin II. While some of these antibodies recognize epitopes conserved between chick and man, others display a narrow species specificity. The results show that proteins whose size, charge, and biochemical behavior are very similar to those of desmoplakin I and band 5 protein of cow snout epidermis are present in all desmosomes examined. These include examples of simple and pseudostratified epithelia and myocardial tissue, in addition to those of stratified epithelia. In contrast, in immunoblotting experiments, we have detected desmoplakin II only among cells of stratified and pseudostratified epithelial tissues. This suggests that the desmosomal plaque structure varies in its complement of polypeptides in a cell-type specific manner. We conclude that the obligatory desmosomal plaque proteins, desmoplakin I and band 5 protein, are expressed in a coordinate fashion but independently from other differentiation programs of expression such as those specific for either epithelial or cardiac cells.

TEMPLATE-BASED ISOCONTOURING

2006 ◽  
Vol 06 (02) ◽  
pp. 187-204 ◽  
Author(s):  
JAGANNATHAN LAKSHMIPATHY ◽  
WIESLAW L. NOWINSKI ◽  
ERIC A. WERNERT
Keyword(s):  
Linear Time ◽  
Cell Types ◽  
Extraction Process ◽  
Extraction Methods ◽  
Lookup Table ◽  
Graphics Hardware ◽  
A Cell ◽  
Triangle Strips ◽  
Different Cell Types

Different isocontour extraction methods use different cell types (tetrahedral, hexahedral, etc.) depending on the nature of the acquisition grids (structured, unstructured, etc.). The existing isocontouring methods have the following pre-steps for the actual extraction process: (a) identification of cell types, (b) identification of topologically independent instances for each cell type, (c) determination of surface primitives contained in the topologically independent instances and (d) generation of a lookup table such that the name of the entry is an instance of a cell and the entry is the triangle set for that instance. The extraction process outputs the triangles from the lookup table. In this paper we present a novel generic method that enables us to list topologically independent surface primitives called "templates" within any n-polytope cell namely tetrahedra, hexahedra etc. We have also modified the traditional lookup table such that name is the cell instance and the entry is face index representations of all template instances contained in that cell. To show an example, we have applied this approach on a hexahedron and listed the templates and subsequently we have showed how to construct a lookup table. Most modern graphics hardware render triangles faster if they are rendered collectively as triangle strips as opposed to individual triangles. With our modified lookup table approach we can identify triangles in the neighboring cell in a linear time and hence we are able to connect two triangle strips into a longer triangle strip on the fly during the extraction process. We have compared our approach with some existing methods. The following are some of the important features of the method: (1) Simplicity, (2) procedural triangulation and (3) face-index representation.

scholarly journals Complex regulation and functional versatility of mammalian alpha- and beta-tubulin isotypes during the differentiation of testis and muscle cells.

1988 ◽  
Vol 106 (6) ◽  
pp. 2023-2033 ◽  
Author(s):  
S A Lewis ◽  
N J Cowan
Keyword(s):  
Cell Types ◽  
Beta Tubulin ◽  
Specific Expression ◽  
Alpha Tubulin ◽  
Tubulin Isotypes ◽  
Tubulin Isotype ◽  
A Cell ◽  
Complex Regulation ◽  
Carboxy Terminal ◽  
Different Cell Types

In the accompanying paper (Gu, W., S. A. Lewis, and N. J. Cowan. 1988. J. Cell Biol. 106: 2011-2022), we report the generation of three antisera, each of which uniquely recognizes a different mammalian alpha-tubulin isotype, plus a fourth antibody that distinguishes between microtubules containing the tyrosinated and nontyrosinated form of the only known mammalian alpha-tubulin gene product that lacks an encoded carboxy-terminal tyrosine residue. These sera, together with five sera we raised that distinguish among the known mammalian beta-tubulin isotypes, have been used to study patterns of tubulin isotype-specific expression in muscle and testis, two tissues in which characteristic developmental changes are accompanied by dramatic rearrangements in microtubule structures. As in the case of cells in culture, there is no evidence to suggest that there is subcellular sorting of different tubulin isotypes among different kinds of microtubule, even in a cell type (the developing spermatid) that simultaneously contains such functionally distinct structures as the manchette and the flagellum. On the other hand, the patterns of expression of the various tubulin isotypes show marked and distinctive differences in different cell types and, in at least one case, evidence is presented for regulation at the translational or posttranslational level. The significance of these observations is discussed in terms of the existence of the mammalian alpha- and beta-tubulin multigene families.

scholarly journals Unravelling the role of Mesenchymal Stem/Stromal Cells Secretome in intervertebral disc degeneration in a pro-inflammatory/degenerative ex vivo model

2020 ◽  
Author(s):  
JR Ferreira ◽  
GQ Teixeira ◽  
E Neto ◽  
C Ribeiro-Machado ◽  
AM Silva ◽  
...  
Keyword(s):  
Gene Expression ◽  
Intervertebral Disc ◽  
Stromal Cells ◽  
Ex Vivo ◽  
Low Oxygen ◽  
Ex Vivo Model ◽  
A Cell ◽  
New Perspective ◽  
Regulated Gene Expression ◽  
Ivd Degeneration

Abstract Background: Mesenchymal stem/stromal cells (MSCs) have been increasingly used in clinical trials for intervertebral disc (IVD) degeneration. Here, we aimed to evaluate the potential of a cell-free approach to degenerated IVD, testing if MSCs secretome can stimulate a regenerative response by modulating the IVD inflammatory cascade. Methods: Human bone marrow-derived MSCs were pre-conditioned with IL-1β (10 ng/mL) and low oxygen (6% O2). The secretome of MSCs (MSCsec) was collected after 48h. Bovine IVD tissue explants cultured in pro-inflammatory/degenerative conditions (needle puncture + IL-1β) were treated with MSCsec or co-cultured with MSCs. Results: MSCsec obtained upon IL-1β-pre-conditioning, as well as MSCs co-culture, down-regulated gene expression of pro-inflammatory cytokines, bIL-6 and bIL-8 after 48h, in IVD. IVD matrix degrading enzymes, bMMP1 and bMMP3, were downregulated and upregulated, respectively, in the presence of MSCsec, but not MSCs. After 14 days, MSCsec-treated IVDs revealed increased aggrecan content at the protein level, contrarily to MSCs/IVD co-cultures. Interestingly, IL-1β-preconditioning only, but not IL-1β-IVD, increased gene expression of hADAMTS5 and hTIMP-1in MSCs. Additionally, conditioned medium from MSCsec-treated IVDs did not promote angiogenesis or neurogenesis. In MSCsec-treated IVD, an increase in MCP-3 and GCP-2 was observed, while SDF-1α, TNF-α, IGF-1, Eotaxin 3, FGF-9, MIP-1δ, IFN-γ, IL-5, TNF-β, IL-4, TGF-β1, IL-16, IGFBP-3 and IGFBP-4 were decreased, compared with MSCs/IVD co-cultures. Conclusions: MSCsec obtained upon IL1β-preconditioning, present an immunomodulatory role in degenerated IVD, as well as MSCs. Nevertheless, MSCsec but not MSCs, potentiate aggrecan deposition in IVD in pro-inflammatory/degenerative conditions. This finding can open new perspective on the use of MSCsec as a cell-based/cell-free approach to LBP.

scholarly journals CD300LF Polymorphisms of Inbred Mouse Strains Confer Resistance to Murine Norovirus Infection in a Cell Type-Dependent Manner

2020 ◽  
Vol 94 (17) ◽  
Author(s):  
Kevin Furlong ◽  
Scott B. Biering ◽  
Jayoung Choi ◽  
Craig B. Wilen ◽  
Robert C. Orchard ◽  
...  
Keyword(s):  
Cell Types ◽  
Host Cells ◽  
Mouse Strains ◽  
Specific Cell ◽  
Dependent Manner ◽  
Murine Norovirus ◽  
Cell Type ◽  
Human Norovirus ◽  
A Cell ◽  
Cell Type Specific

ABSTRACT Human norovirus is the leading cause of gastroenteritis worldwide, yet basic questions about its life cycle remain unanswered due to an historical lack of robust experimental systems. Recent studies on the closely related murine norovirus (MNV) have identified CD300LF as an indispensable entry factor for MNV. We compared the MNV susceptibilities of cells from different mouse strains and identified polymorphisms in murine CD300LF which are critical for its function as an MNV receptor. Bone marrow-derived macrophages (BMDMs) from I/LnJ mice were resistant to infection from multiple MNV strains which readily infect BMDMs from C57BL/6J mice. The resistance of I/LnJ BMDMs was specific to MNV, since the cells supported infection of other viruses comparably to C57BL/6J BMDMs. Transduction of I/LnJ BMDMs with C57BL/6J CD300LF made the cells permissible to MNV infection, suggesting that the cause of resistance lies in the entry step of MNV infection. In fact, we mapped this phenotype to a 4-amino-acid difference at the CC′ loop of CD300LF; swapping of these amino acids between C57BL/6J and I/LnJ CD300LF proteins made the mutant C57BL/6J CD300LF functionally impaired and the corresponding mutant of I/LnJ CD300LF functional as an MNV entry factor. Surprisingly, expression of the I/LnJ CD300LF in other cell types made the cells infectible by MNV, even though the I/LnJ allele did not function as an MNV receptor in macrophage-like cells. Correspondingly, I/LnJ CD300LF bound MNV virions in permissive cells but not in nonpermissive cells. Collectively, our data suggest the existence of a cell type-specific modifier of MNV entry. IMPORTANCE MNV is a prevalent model system for studying human norovirus, which is the leading cause of gastroenteritis worldwide and thus a sizeable public health burden. Elucidating mechanisms underlying susceptibility of host cells to MNV infection can lead to insights on the roles that specific cell types play during norovirus pathogenesis. Here, we show that different alleles of the proteinaceous receptor for MNV, CD300LF, function in a cell type-dependent manner. In contrast to the C57BL/6J allele, which functions as an MNV entry factor in all tested cell types, including human cells, I/LnJ CD300LF does not function as an MNV entry factor in macrophage-like cells but does allow MNV entry in other cell types. Together, these observations indicate the existence of cell type-specific modifiers of CD300LF-dependent MNV entry.

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