| 1. |
- Jonsson, Marianne, 1962, et al.
(författare)
-
Novel 3D culture system with similarities to the human heart for studies of the cardiac stem cell niche.
- 2010
-
Ingår i: Regenerative medicine. - : Future Medicine Ltd. - 1746-076X .- 1746-0751. ; 5:5, s. 725-36
-
Tidskriftsartikel (refereegranskat)abstract
- AIMS: The aim of this study was to develop a 3D culture system with similarities to the human heart, which was suitable for studies of adult cardiac stem or progenitor cells. MATERIALS & METHODS: Dissociated cells from human cardiac biopsies were placed in high-density pellet cultures and cultured for up to 6 weeks. Gene and protein expressions, analyzed by quantitative real-time PCR and immunohistochemistry, and morphology were studied in early and late pellets. RESULTS: Cells cultured in the 3D model showed similarities to human cardiac tissue. Moreover, markers for cardiac stem and progenitor cells were also detected after 6 weeks of culture, in addition to markers for signaling pathways active in stem cell niche regulation. CONCLUSIONS: The described 3D culture model could be a valuable tool when studying the influence of different compounds on proliferation and differentiation processes in cardiac stem or progenitor cells in cardiac regenerative research.
|
|
| 2. |
- Åberg, Jonas, 1982-, et al.
(författare)
-
Biocompatibility and resorption of a radiopaque premixed calcium phosphate cement
- 2012
-
Ingår i: Journal of Biomedical Materials Research. Part A. - : Wiley. - 1549-3296 .- 1552-4965. ; 100A:5, s. 1269-1278
-
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.
|
|
| 3. |
- Åberg, Jonas, 1982-, et al.
(författare)
-
In vitro and in vivo evaluation of an injectable premixed calcium phosphate cement : cell viability and immunological response from rat
- 2010
-
Ingår i: International Journal of Nano and Biomaterials. - 1752-8941. ; 3:3, s. 203-221
-
Tidskriftsartikel (refereegranskat)abstract
- By using premixed calcium phosphate cement (CPC) the handling properties of the cement are drastically improved, which is a challenge for traditional injectable CPC. In this article, a premixed acidic CPC has been compared to a conventional water mixed brushite cement to evaluate whether the premixed concept affects the biological response. The cements were evaluated regarding the pH-variation in simulated body fluid (SBF). Further, the biocompatibility of the cement with human mesenchymal stem cells (MSC) was studied in vitro and eventual inflammation properties studied in vivo, after subcutaneous material injections in rats. A larger pH decrease was seen for the conventional cement than the premixed cement in SBF. For both materials, > 90% of the MSC remained alive in vitro. No systemic or macroscopic inflammation was detected, only a mild microscopic inflammation was detected around both materials. In addition to the handling benefit of premixed cements compared to conventional water mixed CPC, the premixed CPC in the present study demonstrated high and in comparison to conventional CPC comparable biocompability, both in vitro and in vivo.
|
|
| 4. |
- Barreto Henriksson, Helena, et al.
(författare)
-
Identification of Cell Proliferation Zones, Progenitor Cells and a Potential Stem Cell Niche in the Intervertebral Disc Region: A Study in Four Species.
- 2009
-
Ingår i: SPINE. - 0362-2436. ; 34:21, s. 2278-2287
-
Tidskriftsartikel (refereegranskat)abstract
- STUDY DESIGN.: Descriptive experimental study in 4 different mammals. OBJECTIVE.: To investigate cell proliferation/regeneration and localize stem cells/progenitor cells within the intervertebral disc (IVD). SUMMARY OF BACKGROUND DATA.: Disc degeneration (DD) is believed to play a major role in patients with chronic lumbar pain. Lately, biologic treatment options for DD have gained increasing interest. Normal regeneration processes within the IVD and have previously been sparsely described and therefore it is of great interest to increase the knowledge about these processes. METHODS.: Detection of cell proliferations zones and label-retaining cells were done by in vivo 5-bromo-2-deoxyuridine (BrdU) labeling in 18 rabbits, killed after 4, 6, 10, 14, 28, or 56 days. Results were visualized with immunohistochemistry and fluorescence/confocal microscopy. Localization of progenitor cell were further investigated by immunohistochemistry using antibodies towards Notch1, Delta4, Jagged1, C-KIT, KI67, and Stro-1 in normal IVD from rabbits (n = 3), rats (n = 2), minipigs (n = 2), and in human degenerated IVD (n = 4). Further, flowcytometry analysis using progenitor markers were performed on additional human IVD cells (n = 3). RESULTS.: BrdU positive cells were found in comparable numbers at early and late time points in most regions of the anulus fibrosus (AF) and nucleus pulposus demonstrating slow ongoing cell proliferation. In the AF border to ligament zone (AFo) and the perichondriumregion (P) a stem cell niche-like pattern was determined (a high number of BrdU positive cells at early time points vs. only a few label retaining cells at later time points). In normal and DD tissue from the 4 investigated species progenitor cell markers were detected. CONCLUSION.: The IVD is a tissue with ongoing slow cell proliferation both in the AF and the nucleus pulposus. The stem cell niche pattern detected in AFo and P can be suggested to play a role for IVD morphology and function. These findings may be of importance for the development of biologic treatment strategies. PMID: 19755937 [PubMed - as supplied by publisher]
|
|
| 5. |
- Barreto Henriksson, Helena, et al.
(författare)
-
Investigation of different cell types and gel carriers for cell-based intervertebral disc therapy, in vitro and in vivo studies.
- 2012
-
Ingår i: Journal of tissue engineering and regenerative medicine. - : Hindawi Limited. - 1932-7005 .- 1932-6254. ; 6:9, s. 738-747
-
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.
|
|
| 6. |
|
|
| 7. |
- Barreto Henriksson, Helena, et al.
(författare)
-
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
-
Ingår i: Spine. - 0362-2436 .- 1528-1159. ; 37:9, s. 722-732
-
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.
|
|
| 8. |
- Barreto Henriksson, Helena, et al.
(författare)
-
The Traceability of Mesenchymal Stromal Cells After Injection Into Degenerated Discs in Patients with Low Back Pain.
- 2019
-
Ingår i: Stem cells and development. - : Mary Ann Liebert Inc. - 1557-8534 .- 1547-3287. ; 28:17, s. 1203-1211
-
Tidskriftsartikel (refereegranskat)abstract
- Low back pain is a major health issue and one main cause to this condition is believed to be intervertebral disc (IVD) degeneration. Stem cell therapy for degenerated discs using mesenchymal stromal cells (MSCs) has been suggested. The aim of the study was to investigate the presence and distribution pattern of autologous MSCs transplanted into degenerated IVDs in patients and explanted posttransplantation. IVD tissues from four patients (41, 45, 47, and 47 years of age) participating in a clinical feasibility study on MSC transplantation to degenerative discs were investigated. Three patients decided to undergo fusion surgery at time points 8 months and one patient at 28 months posttransplantation. Pretransplantation, MSCs from bone marrow aspirate were isolated by centrifugation in FICOLL® test tubes and cultured (passage 1). Before transplantation, MSCs were labeled with 1mg/mL iron sucrose (Venofer®) and 1×106 MSCs were transplanted into degenerated IVDs. At the time point of surgery, IVD tissues were collected. IVD tissue samples were fixated, embedded in paraffin, and sections prepared. IVD samples were stained with Prussian Blue, by which iron deposits are visualized and examined (light microscopy). Immunohistochemistry (IHC), including SOX9 (sex determining region Y box 9), Coll2A1 (collagen 2A1), and cell viability (TUNEL) were performed. Cells positive for iron deposits were observed in IVD tissues (3/4 patients). The cells/iron deposits were observed in clusters and/or as solitary cells in regions in IVD tissue samples [regions of interest (ROIs)]. By IHC, SOX9- and Coll2A1-positive cells were detected in the same regions as the detected cells/iron deposits. A few nonviable cells were detected by TUNEL assay in ROIs. Results demonstrated that MSCs, labeled with iron sucrose, transplanted into degenerated IVDs were detectable 8 months posttransplantation. The detected cellular activity indicates that MSCs have differentiated into chondrocyte-like cells and that the injected MSCs and/or their progeny have survived since the cells were found in large cluster and as solitary cells which were distributed at different parts of the IVD.
|
|
| 9. |
- Barreto Henriksson, Helena, et al.
(författare)
-
Transplantation of human mesenchymal stems cells into intervertebral discs in a xenogeneic porcine model.
- 2009
-
Ingår i: Spine. - 1528-1159. ; 34:2, s. 141-8
-
Tidskriftsartikel (refereegranskat)abstract
- STUDY DESIGN: Experimental and descriptive study of a xenotransplantation model in minipigs. OBJECTIVE: To study survival and function of human mesenchymal stem cells (hMSCs) after transplantation into injured porcine spinal discs, as a model for cell therapy. SUMMARY OF BACKGROUND DATA: Biologic treatment options of the intervertebral disc are suggested for patients with chronic low back pain caused by disc degeneration. METHODS: Three lumbar discs in each of 9 minipigs were injured by aspiration of the nucleus pulposus (NP), 2 weeks later hMSCs were injected in F12 media suspension (cell/med) or with a hydrogel carrier (Puramatrix) (cell/gel). The animals were sacrificed after 1, 3, or 6 months. Disc appearance was visualized by magnetic resonance imaging. Immunohistochemistry methods were used to detect hMSCs by antihuman nuclear antibody staining, and further performed for Collagen II, Aggrecan, and Collagen I. SOX 9, Aggrecan, Versican, Collagen IA, and Collagen IIA and Collagen IIB human mRNA expression was analyzed by real-time PCR. RESULTS: At magnetic resonance imaging all injured discs demonstrated degenerative signs. Cell/gel discs showed fewer changes compared with cell/med discs and only injured discs at later time points. hMSCs were detected in 9 of 10 of the cell/gel discs and in 8 of 9 of the cell/med discs. Immunostaining for Aggrecan and Collagen type II expression were observed in NP after 3 and 6 months in gel/cell discs and colocalized with the antihuman nuclear antibody. mRNA expression of Collagen IIA, Collagen IIB, Versican, Collagen 1A, Aggrecan, and SOX9 were detected in both cell/med and cell/gel discs at the time points 3 and 6 months by real-time PCR. CONCLUSION: hMSCs survive in the porcine disc for at least 6 months and express typical chondrocyte markers suggesting differentiation toward disc-like cells. As in autologous animal models the combination with a three-dimensional-hydrogel carrier seems to facilitate differentiation and survival of MSCs in the disc. Xenotransplantation seems to be valuable in evaluating the possibility for human cell therapy treatment for intervertebral discs.
|
|
| 10. |
- Brisby, Helena, 1965, et al.
(författare)
-
Moderate Physical Exercise Results in Increased Cell Activity in Articular Cartilage of the Knee Joint in Rats.
- 2013
-
Ingår i: Cells, tissues, organs. - : S. Karger AG. - 1422-6421 .- 1422-6405. ; 198:3, s. 237-248
-
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.
|
|
