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| 2. |
- Barreto Henriksson, Helena, et al.
(författare)
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Development and Regeneration Potential of the Mammalian Intervertebral Disc
- 2013
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Ingår i: Cells Tissues and Organs. - : S. Karger AG. - 1422-6405 .- 1422-6421. ; 197:1
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Forskningsöversikt (refereegranskat)abstract
- At the present time, the normal cell proliferation rate and regeneration processes in the intervertebral disc (IVD) are not fully known. Historically, the IVD has been considered an organ with little or no regenerative capacity. However, several studies have identified the presence of cells expressing progenitor/stem cell markers in adult cartilage tissue and recent data suggest that adult mammalian IVDs have regenerative capacity, albeit slow. The aim of this review is to give an overview of the present knowledge regarding IVD development, regeneration and repair mechanisms in mammals, with a special focus on human discs. At a time when regenerative medicine is making progress and biological treatment options, such as stem cell therapy, are suggested for patients with degenerated discs causing chronic low back pain, basic knowledge about disc cells and their regenerative capacity form a useful basis for the exploration of new treatment options.
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| 3. |
- Barreto Henriksson, Helena, et al.
(författare)
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Investigation of different cell types and gel carriers for cell-based intervertebral disc therapy, in vitro and in vivo studies.
- 2012
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Ingår i: Journal of tissue engineering and regenerative medicine. - : Hindawi Limited. - 1932-7005 .- 1932-6254. ; 6:9, s. 738-747
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Tidskriftsartikel (refereegranskat)abstract
- Biological treatment options for the repair of intervertebral disc damage have been suggested for patients with chronic low back pain. The aim of this study was to investigate possible cell types and gel carriers for use in the regenerative treatment of degenerative intervertebral discs (IVD). In vitro: human mesenchymal cells (hMSCs), IVD cells (hDCs), and chondrocytes (hCs) were cultivated in three gel types: hyaluronan gel (Durolane®), hydrogel (Puramatrix®), and tissue-glue gel (TISSEEL®) in chondrogenic differentiation media for 9days. Cell proliferation and proteoglycan accumulation were evaluated with microscopy and histology. In vivo: hMSCs or hCs and hyaluronan gel were co-injected into injured IVDs of six minipigs. Animals were sacrificed at 3 or 6months. Transplanted cells were traced with anti-human antibodies. IVD appearance was visualized by MRI, immunohistochemistry, and histology. Hyaluronan gel induced the highest cell proliferation in vitro for all cell types. Xenotransplanted hMSCs and hCs survived in porcine IVDs for 6months and produced collagen II in all six animals. Six months after transplantation of cell/gel, pronounced endplate changes indicating severe IVD degeneration were observed at MRI in 1/3 hC/gel, 1/3 hMSCs/gel and 1/3 gel only injected IVDs at MRI and 1/3hMSC/gel, 3/3hC/gel, 2/3 gel and 1/3 injured IVDs showed positive staining for bone mineralization. In 1 of 3 discs receiving hC/gel, in 1 of 3 receiving hMSCs/gel, and in 1 of 3 discs receiving gel alone. Injected IVDs on MRI results in 1 of 3 hMSC/gel, in 3 of 3 hC/gel, in 2 of 3 gel, and in 1 of 3 injured IVDs animals showed positive staining for bone mineralization. The investigated hyaluronan gel carrier is not suitable for use in cell therapy of injured/degenerated IVDs. The high cell proliferation observed in vitro in the hyaluronan could have been a negative factor in vivo, since most cell/gel transplanted IVDs showed degenerative changes at MRI and positive bone mineralization staining. However, this xenotransplantation model is valuable for evaluating possible cell therapy strategies for human degenerated IVDs. Copyright © 2011 John Wiley & Sons, Ltd.
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| 4. |
- Barreto Henriksson, Helena, et al.
(författare)
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Support of Concept that Migrating Progenitor Cells from Stem Cell Niches Contribute to Normal Regeneration of the Adult Mammal Intervertebral Disc: A Descriptive study in the New Zeeland white Rabbit.
- 2012
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Ingår i: Spine. - 0362-2436 .- 1528-1159. ; 37:9, s. 722-732
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Tidskriftsartikel (refereegranskat)abstract
- ABSTRACT: Study Design. Descriptive experimental study performed in rabbits of two age groups.Objective. To study and investigate presence of prechondrocytic cells and cell migration routes in the IVD region, to gain knowledge about the normal IVD regeneration pattern.Summary of Background Data. Disc degeneration is believed to play a major role in patients with chronic lumbar pain. Regeneration processes and cell migration within the intervertebral disc (IVD) have been sparsely described. Therefore it is of interest to increase knowledge of these processes in order to understand pathological conditions of the IVD.Methods. 5-bromo-2-deoxyuridine (BrdU) in vivo labelling was performed in two groups of rabbits, 3 and 9 months old at the beginning of the experiment, in total 27 rabbits. BrdU is incorporated into DNA during mitosis and then it is gradually diluted with each cell division until it finally disappears. Incorporation of BrdU was then visualized by immunohistochemistry (IHC) at different time points providing cell division pattern and presence of slow-cycling cells in the IVD region. IVD tissue was investigated by IHC for: Growth- and differentiation-factor-5 (GDF5), SOX9 (chondrogenic lineage markers), SNAIL homolog1 (SNAI1), SNAIL homolog2 (SLUG)(migration markers) and β1-INTEGRIN (cellular adhesion marker). In addition, GDF5, SOX9 and BMPRIB expression were investigated on genetic level.Results. BrdU+ cells were observed in early time points in the IVD niche, adjacent to the epiphyseal plate, at later time points mainly in outer region of the annulus fibrosus (AF) for both age groups of rabbits, indicating a gradual migration of cells. The presence of SLUG, SNAI1, GDF5, SOX9 and β1-INTEGRIN were found in same regions.Conclusion. The results suggest a cellular migration route from the IVD stem cell niche toward the AF and the inner parts of the IVD. These findings may be of importance for understanding IVD regenerative mechanisms and for future development of biological treatment strategies.
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| 5. |
- Brisby, Helena, 1965, et al.
(författare)
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Moderate Physical Exercise Results in Increased Cell Activity in Articular Cartilage of the Knee Joint in Rats.
- 2013
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Ingår i: Cells, tissues, organs. - : S. Karger AG. - 1422-6421 .- 1422-6405. ; 198:3, s. 237-248
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Tidskriftsartikel (refereegranskat)abstract
- Background: Moderate exercise regimens have shown minor positive effects on matrix turnover in articular cartilage (AC), while effects at cellular level, e.g. proliferation, are scarcely described. Aim: The aim of this study was to investigate the effects of moderate exercise on cell proliferation and recruitment of cells possibly active in regeneration in different regions of cartilage in the rat knee joint. Methods: Eighteen rats were orally given 5-bromo-2-deoxyuridine (BrdU) for 14 days for in vivo DNA labeling. Nine rats underwent treadmill training for 50 min/day, 5 days/week (exercise group), and 9 rats served as controls (no exercise). Animals were sacrificed after 14, 56 and 105 days, and knee joints were harvested. BrdU+ cells were visualized immunohistochemically (IHC) and counted in AC, posterior stem cell niche (PN), potential migration route (PMR; area between PN and the AC border), potential migration area (PMA; region between PN and AC including PN) and epiphyseal cartilage plate (EP) of the tibia and femur. Results: Compared to controls, in the exercise group BrdU+ cells/mm(2) were increased on days 14 (p = 0.022) and 105 (p = 0.045) in AC of the tibia and on day 105 (p = 0.014) in AC of the femur. BrdU+ cell numbers were increased in the PMR region of the tibia on days 14 (p = 0.023) and 105 (p = 0.0018) and in the PMR region of the femur on day 105 (p = 0.0099) as well as in the PMA region of the tibia (p = 0.0008) and femur (p = 0.0080) on day 105. No significant differences in BrdU+ cells/mm(2) were seen in PN or EP between the groups at any time point. Regarding collagen 2A1 expression and proteoglycan accumulation, no significant differences between groups were detected. Conclusions: The results indicate increased cell activity in AC in response to physical exercise and may help to understand the complexity of AC regeneration in the normal mammal knee joint. © 2013 S. Karger AG, Basel.
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| 6. |
- Brisby, Helena, 1965, et al.
(författare)
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The presence of local mesenchymal progenitor cells in human degenerated intervertebral discs and possibilities to influence these in vitro: A descriptive study in humans
- 2013
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Ingår i: Stem Cells and Development. - : Mary Ann Liebert Inc. - 1547-3287 .- 1557-8534. ; 22:5, s. 804-814
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Tidskriftsartikel (refereegranskat)abstract
- Low back pain is common and degenerated discs are believed to be a major cause. In non-degenerated intervertebral discs(IVDs) presence of stem-/progenitor cells was recently reported in different mammals (rabbit,rat,pig). Understanding processes of disc degeneration and regenerative mechanisms within degenerated discs(DDs) is important. The aim of the study was to examine presence of local stem-/progenitor cells in human DDs and if these cell-populations could respond to paracrin stimulation in vitro. Tissue biopsies from the IVD region (L3-S1) was collected from 15 patients, age 34-69 years, undergoing surgery (spinal fusion) and mesenchymal stem cells (MSCs)(iliac crest) from two donors. Non-degenerated disc cells were collected from one donor(scoliosis) and chordoma tissue was obtained from(positive control, stem cell markers) two donors. The IVD biopsies were investigated for gene- and protein expression of: OCT3/4, CD105, CD90, STRO-1 and NOTCH1. DD cell cultures(pellet mass) were performed with conditioned media from MSCs and non-degenerated IVD cells. Pellets were investigated after 7, 14, 28 days for the same stem cell markers as above. Gene expression of OCT3/4 and STRO-1 was detected in 13/15 patient samples, CD105 in 14/15 samples and CD90 and NOTCH1 was detected 15/15 samples. Immunohistochemistry analysis supported findings on protein level, in cells sparsely distributed in DDs tissues. DDs cell-cultures displayed more undifferentiated appearance with increased expression of CD105, CD90, STRO-1, OCT3/4, NOTCH1 and JAGGED1 which was observed when cultured in conditioned cell-culture media from MSC compared to cell-cultures cultured with conditioned media from non-degenerated disc cells. Expression of OCT3/4(multipotency marker) and NOTCH1(regulator of cell fate), MSC- markers CD105, CD90 and STRO-1 indicate that primitive cell populations are present within DDs. Furthermore, the possibility to influence cells from DDs by by paracrin signalling /soluble factors from MSCs and from non-degenerated IVD cells was observed in vitro indicating that repair processes within human degenerated discs may be stimulated.
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| 7. |
- de Peppo, Giuseppe Maria, 1981, et al.
(författare)
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Osteogenic response of human mesenchymal stem cells to well-defined nanoscale topography in vitro
- 2014
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Ingår i: International journal of nanomedicine. - : Informa UK Limited. - 1176-9114 .- 1178-2013. ; 9:1, s. 2499-2515
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Tidskriftsartikel (refereegranskat)abstract
- Background: Patterning medical devices at the nanoscale level enables the manipulation of cell behavior and tissue regeneration, with topographic features recognized as playing a significant role in the osseointegration of implantable devices. Methods: In this study, we assessed the ability of titanium-coated hemisphere-like topographic nanostructures of different sizes (approximately 50, 100, and 200 nm) to influence the morphology, proliferation, and osteogenic differentiation of human mesenchymal stem cells (hMSCs). Results: We found that the proliferation and osteogenic differentiation of hMSCs was influenced by the size of the underlying structures, suggesting that size variations in topographic features at the nanoscale level, independently of chemistry, can be exploited to control hMSC behavior in a size-dependent fashion. Conclusion: Our studies demonstrate that colloidal lithography, in combination with coating technologies, can be exploited to investigate the cell response to well defined nanoscale topography and to develop next-generation surfaces that guide tissue regeneration and promote implant integration.
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| 8. |
- Larsson, Karin, 1955, et al.
(författare)
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Effects of Intervertebral Disc Cells on Neurite Outgrowth From Dorsal Root Ganglion Explants in Culture
- 2011
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Ingår i: Spine (Phila Pa 1976). - 0362-2436. ; 36:8, s. 600-6
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Tidskriftsartikel (refereegranskat)abstract
- STUDY DESIGN.: An experimental study investigating the effect of disc cells on neurite outgrowth in a rat dorsal root ganglion (DRG) culture system. OBJECTIVE.: To examine the effects of the 2 nucleus pulposus (NP) cell populations, notochordal cells (NC) and chondrocyte-like cells (CC) on neurite outgrowth from DRGs. SUMMARY OF BACKGROUND DATA.: NP consists of at least 2 cell populations, NC and CC. The cells in NP have been shown to be responsible for negative effects on neurite outgrowth in vitro and on nerve tissue in vivo. It is unknown whether 1 cell type or combinations of the 2 cell types are responsible for the reported effects. METHODS.: A total of 939 DRGs from newborn Sprague Dawley rats were harvested and placed in culture dishes. After 24 hours, the neurite outgrowth was measured. NP was harvested from tail discs of adult rats and the NP cells were separated into 2 populations, NC and CC. The cell populations were applied to the DRG culture in different cell concentrations and combinations, and compared to medium. After 24 hours of exposure, the neurite outgrowth was reassessed and expressed as the ratio between the outgrowth at 48 and 24 hours culture. RESULTS.: NC in intermediate and high concentration and CC in high concentration induced a significant inhibition of the neurite outgrowth compared to culture medium. Further, one of the combinations (low NC and high CC concentration) resulted in a significant inhibition of the neurite outgrowth. CONCLUSION.: The present study demonstrated negative effects of NP cells on nerve tissue culture explants. The combination of low NC and high CC concentrations may mimic the situation in humans, where we have an increased proportion of chondrocyte-like cells with age. The results from this study may provide a biologic explanation for the large variation of symptoms in disc herniation patients despite similar mechanical influence on nerve tissue.
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| 9. |
- Suzuki, Nobuyuki, 1971, et al.
(författare)
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Physical exercise affects cell proliferation in lumbar intervertebral disc regions in rats
- 2012
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Ingår i: Spine. - 0362-2436. ; 37:17, s. 1440-1447
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Tidskriftsartikel (refereegranskat)abstract
- Study Design. Descriptive experimental study.Objective. The aim of this study was to investigate the effect of exercise on cell proliferation in different areas of the IVD and recruitment of cells possibly active in regeneration of normal rat lumbar IVDs.Summary of Background Data. Little is known about the effects of physical exercise on lumbar intervertebral disc (IVD) tissue. Recently, stem cell niches in the perichondrium area of the IVD were identified and cells in these niches have been suggested to be involved in the normal regeneration of the IVD.Methods. Thirty Sprague-Dawley rats were exposed to 5-bromo-2-deoxyuridine (BrdU) diluted in the drinking water during 14 days. Fifteen rats ran on a treadmill daily for 50 min/day, 5 days/week (exercise group) and 15 non-exercised rats served as controls. Immunohistochemical analyses (anti-BrdU antibody) were performed at 9, 14, 28, 56 and 105 days after the start of the exercise protocol. BrdU positive cells were counted in the stem cell niche area (SN), peripheral region of epiphyseal cartilage area (pEC), the annulus fibrous outer and inner area (AFo and AFi). Data were analyzed by two-way ANOVA (significance level; p<0.05).Results. The BrdU positive cell numbers in the SN and AFo region were increased in discs from the exercising group on days 14 (p<0.01) and 105 (p<0.05) and at day 14 (p<0.01) in the pEC region as compared to controls.Conclusions. Physical exercise was shown to have positive effects on cell proliferation in intervertebral discs with involvement of various disc regions, indicating a differential response by disc tissue to exercise depending on anatomical location and tissue characteristics.
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| 10. |
- Åberg, Jonas, 1982-, et al.
(författare)
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Biocompatibility and resorption of a radiopaque premixed calcium phosphate cement
- 2012
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Ingår i: Journal of Biomedical Materials Research. Part A. - : Wiley. - 1549-3296 .- 1552-4965. ; 100A:5, s. 1269-1278
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Tidskriftsartikel (refereegranskat)abstract
- Calcium phosphate cements (CPC) are used as bone void filler in various orthopedic indications; however, there are some major drawbacks regarding mixing, transfer, and injection of traditional CPC. By using glycerol as mixing liquid, a premixed calcium phosphate cement (pCPC), some of these difficulties can be overcome. In the treatment of vertebral fractures the handling characteristics need to be excellent including a high radio-opacity for optimal control during injection. The aim of this study is to evaluate a radiopaque pCPC regarding its resorption behavior and biocompatibility in vivo. pCPC and a water-based CPC were injected into a circle divide 4-mm drilled femur defect in rabbits. The rabbits were sacrificed after 2 and 12 weeks. Cross sections of the defects were evaluated using histology, electron microscopy, and immunohistochemical analysis. Signs of inflammation were evaluated both locally and systemically. The results showed a higher bone formation in the pCPC compared to the water-based CPC after 2 weeks by expression of RUNX-2. After 12 weeks most of the cement had been resorbed in both groups. Both materials were considered to have a high biocompatibility since no marked immunological response was induced and extensive bone ingrowth was observed. The conclusion from the study was that pCPC with ZrO2 radiopacifier is a promising alternative regarding bone replacement material and may be suggested for treatment of, for example, vertebral fractures based on its high biocompatibility, fast bone ingrowth, and good handling properties.
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