| 1. |
- de Peppo, Giuseppe Maria, 1981, et al.
(författare)
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Free-form-fabricated commercially-pure Ti and Ti6Al4V porous scaffolds support the growth of human embryonic stem cell-derived medsodermal progenitors
- 2012
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Ingår i: The Scientific World Journal. - : Hindawi Limited. - 2356-6140 .- 1537-744X. ; 2012
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Tidskriftsartikel (refereegranskat)abstract
- Commercially-pure titanium (cp-Ti) and the titanium-aluminum-vanadium alloy (Ti6Al4V) are widely used as reconstructive implants for skeletal engineering applications, due to their good mechanical properties, biocompatibility and ability to integrate with the surrounding bone. Electron beam melting technology (EBM) allows the fabrication of customized implants with tailored mechanical properties and high potential in the clinical practice. In order to augment the interaction with the biological tissue, stem cells have recently been combined with metallic scaffolds for skeletal engineering applications. We previously demonstrated that human embryonic stem cell-derived mesodermal progenitors (hES-MPs) hold a great potential to provide a homogeneous and unlimited supply of cells for bone engineering applications. This study demonstrates the effect of EBM-fabricated cp-Ti and Ti6Al4V porous scaffolds on hES-MPs behavior, in terms of cell attachment, growth and osteogenic differentiation. Displaying different chemical composition but similar surface properties, EBM-fabricated cp-Ti and Ti6Al4V scaffolds supported cell attachment and growth, and did not seem to alter the expression of genes involved in osteogenic differentiation and affect the alkaline phosphatase activity. In conclusion, interfacing hES-MPs to EBM-fabricated scaffolds may represent an interesting strategy for design of third-generation biomaterials, with the potential to promote implant integration in clinical conditions characterized by poor bone quality. Copyright 2012 G. M. de Peppo et al.
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| 2. |
- de Peppo, Giuseppe Maria, 1981, et al.
(författare)
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Human Embryonic Stem Cell-Derived Mesodermal Progenitors Display Substantially Increased Tissue Formation Compared to Human Mesenchymal Stem Cells Under Dynamic Culture Conditions in a Packed Bed/Column Bioreactor.
- 2013
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Ingår i: Tissue engineering. Part A. - 1937-335X. ; 19:1-2, s. 175-87
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Tidskriftsartikel (refereegranskat)abstract
- Bone tissue engineering represents a promising strategy to obviate bone deficiencies, allowing the ex vivo construction of bone substitutes with unprecedented potential in the clinical practice. Considering that in the human body cells are constantly stimulated by chemical and mechanical stimuli, the use of bioreactor is emerging as an essential factor for providing the proper environment for the reproducible and large-scale production of the engineered substitutes. Human mesenchymal stem cells (hMSCs) are experimentally relevant cells but, regardless the encouraging results reported after culture under dynamic conditions in bioreactors, show important limitations for tissue engineering applications, especially considering their limited proliferative potential, loss of functionality following protracted expansion, and decline in cellular fitness associated with aging. On the other hand, we previously demonstrated that human embryonic stem cell-derived mesodermal progenitors (hES-MPs) hold great potential to provide a homogenous and unlimited source of cells for bone engineering applications. Based on prior scientific evidence using different types of stem cells, in the present study we hypothesized that dynamic culture of hES-MPs in a packed bed/column bioreactor had the potential to affect proliferation, expression of genes involved in osteogenic differentiation, and matrix mineralization, therefore resulting in increased bone-like tissue formation. The reported findings suggest that hES-MPs constitute a suitable alternative cell source to hMSCs and hold great potential for the construction of bone substitutes for tissue engineering applications in clinical settings.
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| 3. |
- Karlsson, Camilla, 1977, et al.
(författare)
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Differentiation of human mesenchymal stem cells and articular chondrocytes: analysis of chondrogenic potential and expression pattern of differentiation-related transcription factors.
- 2007
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Ingår i: Journal of orthopaedic research : official publication of the Orthopaedic Research Society. - : Wiley. - 0736-0266. ; 25:2, s. 152-63
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Tidskriftsartikel (refereegranskat)abstract
- Mesenchymal stem cells (MSCs) are a candidate for replacing chondrocytes in cell-based repair of cartilage lesions. However, it has not been clarified if these cells can acquire the hyaline phenotype, and whether chondrocytes and MSCs show the same expression patterns of critical control genes in development. In order to study this, articular chondrocytes and iliac crest derived MSCs were allowed to differentiate in pellet mass cultures. Gene expression of markers for the cartilage phenotype, helix-loop-helix (HLH) transcription factors, and chondrogenic transcription factors were analyzed by real-time PCR. Matrix production was assayed using biochemical analysis for hydroxyproline, glycosaminoglycans, and immunohistochemistry for collagen types I and II. Significantly decreased expression of collagen type I was accompanied by increased expression of collagen types IIA and IIB during differentiation of chondrocytes, indicating differentiation towards a hyaline phenotype. Chondrogenesis in MSCs on the other hand resulted in up-regulation of collagen types I, IIA, IIB, and X, demonstrating differentiation towards cartilage of a mixed phenotype. Expression of HES1 increased significantly during chondrogenesis in chondrocytes while expression in MSCs was maintained at a low level. The HLH gene HES5 on the other hand was only detected in chondrocytes. Expression of ID1 decreased significantly in chondrocytes while the opposite was seen in MSCs. These findings suggest that chondrocytes and MSCs differentiated and formed different subtypes of cartilage, the hyaline and a mixed cartilage phenotype, respectively. Differentially regulated HLH genes indicated the possibility for HLH proteins in regulating chondrogenic differentiation. This information is important to understand the potential use of MSCs in cartilage repair.
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| 4. |
- Karlsson, Camilla, 1977, et al.
(författare)
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Notch and HES5 are regulated during human cartilage differentiation.
- 2007
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Ingår i: Cell and tissue research. - : Springer Science and Business Media LLC. - 0302-766X .- 1432-0878. ; 327:3, s. 539-51
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Tidskriftsartikel (refereegranskat)abstract
- The molecular mechanisms of cartilage differentiation are poorly understood. In a variety of tissues other than cartilage, members of the basic helix-loop-helix (bHLH) family of transcription factors have been demonstrated to play critical roles in differentiation. We have characterized the human bHLH gene HES5 and investigated its role during chondrogenesis. Blockage of the Notch signaling pathway with a gamma-secretase inhibitor has demonstrated that the human HES5 gene is a downstream marker of Notch signaling in articular chondrocytes. Markers for the Notch signaling pathway significantly decrease during cartilage differentiation in vitro. Cell proliferation assayed by using BrdU has revealed that blockage of Notch signaling is associated with significantly decreased proliferation. Northern blot and reverse transcription/polymerase chain reaction of a panel of various tissues have shown that HES5 is transcribed as a 5.4-kb mRNA that is ubiquitously expressed in diverse fetal and adult tissues. Articular cartilage from HES5(-/-) and wild-type mice has been analyzed by using various histological stains. No differences have been detected between the wild-type and HES5(-/-) mice. Our data thus indicate that the human HES5 gene is coupled to the Notch receptor family, that expression of Notch markers (including HES5) decreases during cartilage differentiation, and that the blockage of Notch signaling is associated with significantly decreased cell proliferation.
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| 5. |
- Karlsson, Camilla, 1977, et al.
(författare)
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Notch1, Jagged1, and HES5 are abundantly expressed in osteoarthritis.
- 2008
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Ingår i: Cells, tissues, organs. - : S. Karger AG. - 1422-6421 .- 1422-6405. ; 188:3, s. 287-98
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Notch signalling controls differentiation and proliferation in various cell types and is associated with several diseases. We investigated the localization and regulation of several Notch markers in human osteoarthritic (OA) cartilage as well as identified genes controlled by Notch signalling. METHODS: Immunolocalization and real-time PCR analysis of Notch markers in healthy and OA articular cartilage were performed. Genes regulated by Notch signalling were studied using microarray. Cytokine-induced transcription of Notch markers was analyzed using real-time PCR and its effect on cellular localization of the intracellular domain of Notch1 (NICD1) was investigated using immunohistochemistry, subcellular fractionation, and transfection. The effect of NFkappaB activation on HES5 transcription was studied using the NFkappaB inhibitor pyrrolidine dithiocarbamate. RESULTS: Notch signalling was activated in OA cartilage and Notch1, Jagged1, and HES5 were abundantly expressed compared to healthy cartilage. Notch signalling regulated the expression of several genes associated with OA, like interleukin-8, lubricin, CD10, matrix metalloproteinase-9, and bone morphogenetic protein-2. Cytokines significantly affected the expression of several Notch markers and repressed expression of HES5, but did not affect the cellular localization of NICD1. CONCLUSION: Notch signalling is dysregulated in OA, inducing and repressing transcription of genes that could potentially partly contribute to the OA phenotype.
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| 6. |
- Larsson, Alice, et al.
(författare)
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Do patients with large vessel occlusion ischemic stroke harboring prestroke disability benefit from thrombectomy?
- 2020
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Ingår i: Journal of Neurology. - : Springer Science and Business Media LLC. - 0340-5354 .- 1432-1459. ; 267
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Evidence of endovascular treatment (EVT) for acute large vessel occlusion (LVO) ischemic stroke in patients harboring substantial prestroke disability is lacking due to their exclusion from randomized trials. Here, we used routine care observational data to compare outcomes in patients with and without prestroke disability receiving EVT for LVO ischemic stroke. Methods: Consecutive patients undergoing EVT for acute LVO ischemic stroke at the Sahlgrenska University Hospital from January 1st, 2015 to March 31st, 2018 were registered in the Sahlgrenska Stroke Recanalization Registry. Pre- and poststroke functional levels were assessed by the modified Rankin Scale (mRS). Outcomes were recanalization rate (mTICI = 2b/3), symptomatic intracranial hemorrhage [sICH], complications during hospital stay, and return to prestroke functional level and mortality at 3 months. Results: Among 591 patients, 90 had prestroke disability (mRS ≥ 3). The latter group were older, more often female, had more comorbidities and higher NIHSS scores before intervention compared to patients without prestroke disability. Recanalization rates (80.0% vs 85.0%, p = 0.211), sICH (2.2% vs 6.3% p = 0.086) and the proportion of patients returning to prestroke functional level (22.7% vs 14.8% p = 0.062) did not significantly differ between those with and without prestroke disability. Patients with prestroke disability had higher complication rates during hospital stay (55.2% vs 40.1% p < 0.01) and mortality at 3 months (48.9% vs 24.3% p < 0.001). Conclusion: One of five with prestroke disability treated with thrombectomy for a LVO ischemic stroke returned to their prestroke functional level. However, compared to patients without prestroke disability, mortality at 3 months was higher. © 2020, The Author(s).
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| 7. |
- Nordanstig, Annika, 1974, et al.
(författare)
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EndoVAscular treatment and ThRombolysis for Ischemic Stroke Patients (EVA-TRISP) registry: basis and methodology of a pan-European prospective ischaemic stroke revascularisation treatment registry.
- 2021
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Ingår i: BMJ open. - : BMJ. - 2044-6055. ; 11:8
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Tidskriftsartikel (refereegranskat)abstract
- The Thrombolysis in Ischemic Stroke Patients (TRISP) collaboration was a concerted effort initiated in 2010 with the purpose to address relevant research questions about the effectiveness and safety of intravenous thrombolysis (IVT). The collaboration also aims to prospectively collect data on patients undergoing endovascular treatment (EVT) and hence the name of the collaboration was changed from TRISP to EVA-TRISP. The methodology of the former TRISP registry for patients treated with IVT has already been published. This paper focuses on describing the EVT part of the registry.All centres committed to collecting predefined variables on consecutive patients prospectively. We aim for accuracy and completeness of the data and to adapt local databases to investigate novel research questions. Herein, we introduce the methodology of a recently constructed academic investigator-initiated open collaboration EVT registry built as an extension of an existing IVT registry in patients with acute ischaemic stroke (AIS).Currently, the EVA-TRISP network includes 20 stroke centres with considerable expertise in EVT and maintenance of high-quality hospital-based registries. Following several successful randomised controlled trials (RCTs), many important clinical questions remain unanswered in the (EVT) field and some of them will unlikely be investigated in future RCTs. Prospective registries with high-quality data on EVT-treated patients may help answering some of these unanswered issues, especially on safety and efficacy of EVT in specific patient subgroups.This collaborative effort aims at addressing clinically important questions on safety and efficacy of EVT in conditions not covered by RCTs. The TRISP registry generated substantial novel data supporting stroke physicians in their daily decision making considering IVT candidate patients. While providing observational data on EVT in daily clinical practice, our future findings may likewise be hypothesis generating for future research as well as for quality improvement (on EVT). The collaboration welcomes participation of further centres willing to fulfill the commitment and the outlined requirements.
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| 8. |
- Barreto Henriksson, Helena, et al.
(författare)
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Identification of Cell Proliferation Zones, Progenitor Cells and a Potential Stem Cell Niche in the Intervertebral Disc Region: A Study in Four Species.
- 2009
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Ingår i: SPINE. - 0362-2436. ; 34:21, s. 2278-2287
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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]
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| 9. |
- Bigdeli, Narmin, 1974, et al.
(författare)
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Coculture of human embryonic stem cells and human articular chondrocytes results in significantly altered phenotype and improved chondrogenic differentiation.
- 2009
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Ingår i: Stem cells (Dayton, Ohio). - : Oxford University Press (OUP). - 1549-4918 .- 1066-5099. ; 27:8, s. 1812-21
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Tidskriftsartikel (refereegranskat)abstract
- Human embryonic stem (hES) cells have been suggested as a cell source for the repair of cartilage lesions. Here we studied how coculture with human articular chondrocytes affects the expansion potential, morphology, expression of surface markers, and differentiation abilities of hES cells, with special regard to chondrogenic differentiation. Undifferentiated hES cells were cocultured with irradiated neonatal or adult articular chondrocytes in high-density pellet mass cultures for 14 days. Cocultured hES cells were then expanded on plastic and their differentiation potential toward the adipogenic, osteogenic, and chondrogenic lineages was compared with that of undifferentiated hES cells. The expression of different surface markers was investigated using flow cytometry and teratoma formation was studied using injection of the cells under the kidney capsule. Our results demonstrate that although hES cells have to be grown on Matrigel, the cocultured hES cells could be massively expanded on plastic with a morphology and expression of surface markers similar to mesenchymal stem cells. Coculture further resulted in a more homogenous pellet and significantly increased cartilage matrix production, both in high-density pellet mass cultures and hyaluronan-based scaffolds. Moreover, cocultured cells formed colonies in agarose suspension culture, also demonstrating differentiation toward chondroprogenitor cells, whereas no colonies were detected in the hES cell cultures. Coculture further resulted in a significantly decreased osteogenic potential. No teratoma formation was detected. Our results confirm the potential of the culture microenvironment to influence hES cell morphology, expansion potential, and differentiation abilities over several population doublings.
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| 10. |
- Bigdeli, Narmin, 1974, et al.
(författare)
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Superior Osteogenic Capacity of Human Embryonic Stem Cells Adapted to Matrix-Free Growth Compared to Human Mesenchymal Stem Cells.
- 2010
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Ingår i: Tissue engineering. Part A. - : Mary Ann Liebert Inc. - 1937-335X .- 1937-3341. ; 16:11, s. 3427-3440
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Tidskriftsartikel (refereegranskat)abstract
- Human mesenchymal stem cells (hMSCs) represent a promising source of cells for bone tissue engineering. However, their low frequencies and limited proliferation restrict their clinical utility. An alternative is the use of human embryonic stem cells (hESCs), but labor-intensive expansion with the need for coating support limits their clinical use. We have previously derived a cell line from hESCs denoted matrix-free growth (MFG)-hESC that are independent of coating support for expansion, and we here compare its osteogenic capacity to that of hMSCs. Microarray analysis of hMSCs and MFG-hESCs revealed differential expression of genes involved in ossification. MFG-hESCs have significantly higher expression of secreted phosphoprotein 1 (SPP1) during osteogenic differentiation, whereas the opposite was true for alkaline phosphatase (ALPL), transforming growth factor, beta 1 (TGFB2), runt-related transcription factor 2 (RUNX2), and forkhead box C1 (FOXC1), as well as the activity of the ALPL enzyme, demonstrating that these two cell types differentiate into the osteogenic lineage using different signaling pathways. von Kossa staining, time-of-flight secondary ion mass spectrometry, and measurement of calcium and phosphate in the extracellular matrix demonstrated a superior ability of the MFG-hESCs to produce a mineralized matrix compared to hMSCs. The superior ability of the MFG-hESCs to form mineralized matrix compared to hMSCs demonstrates that MFG-hESCs are a promising alternative to the use of adult stem cells in future bone regenerative applications.
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