| 1. |
- Jones, Iwan, et al.
(författare)
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Development and validation of an in vitro model system to study peripheral sensory neuron development and injury
- 2018
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- The ability to discriminate between diverse types of sensation is mediated by heterogeneous populations of peripheral sensory neurons. Human peripheral sensory neurons are inaccessible for research and efforts to study their development and disease have been hampered by the availability of relevant model systems. The in vitro differentiation of peripheral sensory neurons from human embryonic stem cells therefore provides an attractive alternative since an unlimited source of biological material can be generated for studies that specifically address development and injury. The work presented in this study describes the derivation of peripheral sensory neurons from human embryonic stem cells using small molecule inhibitors. The differentiated neurons express canonical- and modality-specific peripheral sensory neuron markers with subsets exhibiting functional properties of human nociceptive neurons that include tetrodotoxin-resistant sodium currents and repetitive action potentials. Moreover, the derived cells associate with human donor Schwann cells and can be used as a model system to investigate the molecular mechanisms underlying neuronal death following peripheral nerve injury. The quick and efficient derivation of genetically diverse peripheral sensory neurons from human embryonic stem cells offers unlimited access to these specialised cell types and provides an invaluable in vitro model system for future studies.
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| 2. |
- Jonsson, Samuel, et al.
(författare)
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Effect of delayed peripheral nerve repair on nerve regeneration, Schwann cell function and target muscle recovery
- 2013
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Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 8:2
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Tidskriftsartikel (refereegranskat)abstract
- Despite advances in surgical techniques for peripheral nerve repair, functional restitution remains incomplete. The timing of surgery is one factor influencing the extent of recovery but it is not yet clearly defined how long a delay may be tolerated before repair becomes futile. In this study, rats underwent sciatic nerve transection before immediate (0) or 1, 3, or 6 months delayed repair with a nerve graft. Regeneration of spinal motoneurons, 13 weeks after nerve repair, was assessed using retrograde labeling. Nerve tissue was also collected from the proximal and distal stumps and from the nerve graft, together with the medial gastrocnemius (MG) muscles. A dramatic decline in the number of regenerating motoneurons and myelinated axons in the distal nerve stump was observed in the 3- and 6-months delayed groups. After 3 months delay, the axonal number in the proximal stump increased 2-3 folds, accompanied by a smaller axonal area. RT-PCR of distal nerve segments revealed a decline in Schwann cells (SC) markers, most notably in the 3 and 6 month delayed repair samples. There was also a progressive increase in fibrosis and proteoglycan scar markers in the distal nerve with increased delayed repair time. The yield of SC isolated from the distal nerve segments progressively fell with increased delay in repair time but cultured SC from all groups proliferated at similar rates. MG muscle at 3- and 6-months delay repair showed a significant decline in weight (61% and 27% compared with contra-lateral side). Muscle fiber atrophy and changes to neuromuscular junctions were observed with increased delayed repair time suggestive of progressively impaired reinnervation. This study demonstrates that one of the main limiting factors for nerve regeneration after delayed repair is the distal stump. The critical time point after which the outcome of regeneration becomes too poor appears to be 3-months.
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| 3. |
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| 4. |
- Lauvrud, Anne Therese, et al.
(författare)
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Water jet-assisted lipoaspiration and Sepax cell separation system for the isolation of adipose stem cells with high adipogenic potential
- 2021
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Ingår i: Journal of Plastic, Reconstructive & Aesthetic Surgery. - : Elsevier. - 1748-6815 .- 1878-0539. ; 74:10, s. 2759-2767
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Water jet-assisted liposuction has gained popularity due to favourable fat grafting outcomes. In this study, we compared stem cells obtained from fat isolated with manual or the water jet-assisted procedure.Methods: Liposuction of abdominal fat was performed using the two methods on each donor (n = 10). Aspirate samples were collagenase digested and the isolated cells seeded in vitro prior to proliferation, adipogenic differentiation and angiogenic activity analyses.Results: Cells from either procedure proliferated at similar rates and exhibited a similar colony-forming ability. The cells expressed stem cell markers CD73, CD90 and CD105. In the water jet cell preparations, there were higher numbers of cells expressing CD146. Robust adipogenic differentiation was observed in cultures expanded from both manual and water jet lipoaspirates. Gene analysis showed higher expression of the adipocyte markers aP2 and GLUT4 in the adipocyte-differentiated water jet cell preparations, and ELISA indicated increased secretion of adiponectin from these cells. Both cell groups expressed vasculogenic factors and the water jet cells promoted the highest levels of in vitro angiogenesis. Given these positive results, we further characterised the water jet cells when prepared using an automated closed cell processing unit, the Sepax-2 system (Cytiva). The growth and stem cell properties of the Sepax-processed cells were similar to the standard centrifugation protocol, but there was evidence for greater adipogenic differentiation in the Sepax-processed cells.Conclusions: Water jet lipoaspirates yield cells with high adipogenic potential and angiogenic activity, which may be beneficial for use in cell-assisted lipotransfers.
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| 5. |
- McGrath, Aleksandra M., et al.
(författare)
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Long-Term Effects of Fibrin Conduit with Human Mesenchymal Stem Cells and Immunosuppression after Peripheral Nerve Repair in a Xenogenic Model
- 2018
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Ingår i: Cell Medicine. - : SAGE Publications. - 2155-1790. ; 10, s. 1-13
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Previously we showed that a fibrin glue conduit with human mesenchymal stem cells (hMSCs) and cyclosporine A (CsA) enhanced early nerve regeneration. In this study long term effects of this conduit are investigated. Methods: In a rat model, the sciatic nerve was repaired with fibrin conduit containing fibrin matrix, fibrin conduit containing fibrin matrix with CsA treatment and fibrin conduit containing fibrin matrix with hMSCs and CsA treatment, and also with nerve graft as control. Results: At 12 weeks 34% of motoneurons of the control group regenerated axons through the fibrin conduit. CsA treatment alone or with hMSCs resulted in axon regeneration of 67% and 64% motoneurons respectively. The gastrocnemius muscle weight was reduced in the conduit with fibrin matrix. The treatment with CsA or CsA with hMSCs induced recovery of the muscle weight and size of fast type fibers towards the levels of the nerve graft group. Discussion: The transplantation of hMSCs for peripheral nerve injury should be optimized to demonstrate their beneficial effects. The CsA may have its own effect on nerve regeneration.
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| 6. |
- Andersson, Magnus N., et al.
(författare)
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Prophylactic mastectomy – Correlation between skin flap thickness and residual glandular tissue evaluated postoperatively by imaging
- 2022
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Ingår i: Journal of Plastic, Reconstructive & Aesthetic Surgery. - : Elsevier. - 1748-6815 .- 1878-0539. ; 75:6, s. 1813-1819
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Tidskriftsartikel (refereegranskat)abstract
- Background: Women with an increased hereditary risk of breast cancer can undergo risk-reducing prophylactic mastectomy. However, there is a balance between how much subcutaneous tissue should be resected to achieve maximal reduction of glandular tissue, while leaving viable skin flaps.Methods: Forty-five women previously operated with prophylactic mastectomy underwent magnetic resonance tomography (MRT) and ultrasound (US) to investigate the correlation between skin flap thickness and residual glandular tissue. Residual glandular tissue was documented as being present or not present, but not quantified, as the amount of residual glandular tissue in many cases was considered too small to make reliable volume quantifications with available tools. Since a mastectomy skin flap thickness of 5 mm is discussed as an oncologically safe thickness in the literature, this was used as a cut-off.Results: Following prophylactic mastectomy, residual glandular tissue was detected in 39.3% of all breasts and 27.9% of all the breast quadrants examined by MRT, and 44.1% of all breasts and 21.7% of all the breast quadrants examined by US. Residual glandular tissue was detected in 6.9% of the quadrants in skin flaps ≤ 5 mm and in 37.5% of the quadrants in skin flaps > 5 mm (OR 3.07; CI = 1.41–6.67; p = 0.005). Furthermore, residual glandular tissue increased significantly already when the skin flap thickness exceeded 7 mm.Conclusions: This study highlights that complete removal of glandular breast tissue during a mastectomy is difficult and suggests that this is an unattainable goal. We demonstrate that residual glandular tissue is significantly higher in skin flaps > 5 mm in comparison to skin flaps ≤ 5 mm, and that residual glandular tissue increases significantly already when the flap thickness exceeds 7 mm.
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| 7. |
- Lauvrud, Anne Therese, 1975-
(författare)
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Optimizing stem cells for reconstructive surgery
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Fat grafting has become an established method in plastic surgery for treating soft tissue defects. The results for survival of the fat being transplanted is unpredictable and supplementation of the graft with the Stromal Vascular Fraction (SVF) or cultures Adipose tissue-derived stem cells (ASCs) can enhance graft viability. The ASCs are a heterogenous group of cells with various cell membrane markers, and differing growth promoting and differentiation characteristics of the stem cells derived from the fat. It is of high importance when expanding cells prior to the transplantation of the cells into patients, that the culture conditions are well defined and ideally are xenofree, avoiding use of animal-derived products. Furthermore, the procedures must be safe and not increase risk for recurrence of cancer after reconstructive surgeries. This thesis explores the phenotypic properties of a selected population of ASCs, with a view to determining their suitability for transplantation into fat grafts. ASCs were isolated from SVF of human abdominal fat and CD146+ cells were selected using immunomagnetic beads. The proliferation, angiogenic and adipogenic properties were significantly higher in the CD146+ cells. Stem cells were also isolated from lipoaspirate obtained using two different liposuction methods. Waterjet lipoaspirates yielded the greatest number of CD146+ cells with high adipogenic potential and angiogenic activity. The cells could also be successfully isolated using a closed processing system. Cells were expanded in either foetal bovine serum, platelet lysate or a chemically defined xenofree (XV) medium. Cultures in XV medium proliferated the fastest, expressed the highest number of CD146+ cells, and showed the best adipogenic and angiogenic properties. To test possible ASCs interactions with cancer cells, co-cultures with MCF-7 breast cancer cells were established. Conditioned medium from co-cultures significantly increased the migration of the cancer cells but not their proliferation, and there was increased expression of Tenascin-C in these cultures. The research in this thesis work has shown more optimal ways to isolate and expand ASCs, potentially offering new therapeutic reconstructive treatment options for a variety of medical conditions.
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| 8. |
- Nyström, Maria, et al.
(författare)
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Interaction of adipose-derived stem cells with active and dormant breast cancer cells
- 2023
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Ingår i: Journal of Plastic, Reconstructive & Aesthetic Surgery. - : Elsevier. - 1748-6815 .- 1878-0539. ; 83, s. 69-76
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Tidskriftsartikel (refereegranskat)abstract
- Background: Although autologous fat grafting is considered a successful method for the management of contour deformities, the fat graft could potentially induce cancer reappearance by fueling dormant breast cancer cells. Our aim was to characterize the role of adipose-derived stem cells on active and dormant breast cancer cell growth.Methods: Cobalt chloride was used to induce dormancy in MCF-7 cancer cells. Proliferation of active and dormant cancer cells was determined in the presence of adipose-derived stem cells. A proteome array was used to detect cancer-related protein expression in the cell-conditioned medium. The migration of cancer cells was measured in response to conditioned medium from the adipose-derived stem cells.Results: The adipose-derived stem cells showed variable effects on active MCF-7 cells growth and inhibited MCF-7 proliferation after the withdrawal of cobalt chloride. Of the 84 different proteins measured in the conditioned medium, only tenascin-C was differentially expressed in the co-cultures. MCF-7 cells alone did not express tenascin-C, whereas co-cultures between MCF-7 and adipose-derived stem cells expressed more tenascin-C versus adipose-derived stem cells alone. The conditioned medium from co-cultures significantly increased the migration of the cancer cells.Conclusions: Adipose-derived stem cells themselves neither increased the growth or migration of cancer cells, suggesting that autologous fat grafting may be oncologically safe if reconstruction is postponed until there is no evidence of active disease. However, interactions between adipose-derived stem cells and MCF-7 cancer cells could potentially lead to the production of factors, which further promote cancer cell migration.
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| 9. |
- Pérez-Díaz, Sergio, et al.
(författare)
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The potential role of collagen type VII in breast cancer proliferation
- 2024
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Ingår i: Cancer Cell International. - : Springer Nature. - 1475-2867. ; 24:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Breast cancer is the most common cancer in women. Cancer cells can persist in a prolonged dormant state for years without any clinical evidence of disease creating an urgent need to better understand the molecular mechanisms leading to relapse. This study aimed to identify extracellular matrix (ECM) components associated with hypoxia-induced breast cancer dormancy. The effects of selected ECM proteins on breast cancer cell proliferation were analyzed, along with their correlation with established prognostic markers in human breast cancer tissue.Materials and methods: Screening of extracellular matrix proteins was performed in hypoxia-induced dormant MCF-7 breast cancer cells. Proliferation of MCF-7 cells in vitro was subsequently determined in the presence of recombinant ColVII. Adipose tissue-derived mesenchymal stem cells (AdMSCs) subpopulation overexpressing ColVII were indirectly isolated by ColVII receptor integrin-α6 specific antibodies. AdMSCs- MCF-7 3D spheroid cultures were generated to model solid tumour conditions. In addition, the association between ColVII and various prognostic markers was evaluated in clinical samples of human breast cancer tissue.Results: Dormant MCF-7 cells showed an elevated expression of ColVII while MCF-7 cells cultured on ColVII exhibited reduced proliferation in vitro. In AdMSCs-MCF-7 3D spheroids, a reduced proliferation of MCF-7 cells was observed in Int-α6+/ ColVIIhigh compared with Int-α6-/ ColVIIlow AdMSCs spheroids. In human tissue, high ColVII expression correlated to several positive prognostic markers. Staining for Cytokeratin-5 revealed that ColVIIhigh-expressing cells were predominantly myoepithelial cells.Conclusion: ColVII is associated with reduced proliferation of breast cancer cells in vitro. ColVII is strongly expressed in myoepithelial cells and in breast cancer tissue the high ColVII expression correlates with several well-known positive prognostic markers, highlighting its potential as a prognostic marker in breast cancer.
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| 10. |
- Skoglund, Märta A, et al.
(författare)
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Inter- and intra-observer agreement on evaluating the presence of residual glandular tissue with magnetic resonance tomography following prophylactic mastectomy
- 2023
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Ingår i: Acta Radiologica. - : Sage Publications. - 0284-1851 .- 1600-0455. ; 64:1, s. 67-73
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Tidskriftsartikel (refereegranskat)abstract
- Background: There are no published international consensus or guideline documents regarding appropriate medical follow-up for women with hereditary increased risk of breast cancer who opt for prophylactic mastectomy. Moreover, it is not known whether breast magnetic resonance imaging (MRI) performed after a prophylactic mastectomy is a reproducible method for evaluating whether clinically relevant amounts of residual glandular tissue remains.Purpose: To evaluate the inter- and intra-observer agreement on detecting residual glandular tissue with MRI. Material and Methods: In total, 40 women previously operated with prophylactic mastectomy underwent MRI and two breast radiologists (R1 and R2) independently assessed the presence of residual glandular tissue. Inter- and intra-rater agreements were assessed using Cohen's kappa (k).Results: Residual glandular tissue was found in 69 of 248 quadrants (27.8%) and 32 of 62 breasts (51.6%) by R1 and 77 of 248 quadrants (31.1%) and 35 of 62 breasts (56.5%) by R2. The interrater agreement was observed to be moderate (k = 0.554) and the intra-rater agreement was observed to be substantial (k = 0.623).Conclusion: In conclusion, the inter-and intra-rater observer agreement in regard to detection of residual glandular tissue was not excellent, which would be desirable for a method considered reproducible enough to be used as a surveillance tool after the surgical procedure in order to ensure that there is no relevant residual glandular tissue remaining warranting further follow-up. More research is needed, as well as establishment of precise protocols, before using the method in risk assessment of remaining glandular tissue and breast cancer risk.
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