| 31. |
- Wallenquist, Ulrika, 1975-, et al.
(författare)
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Grafted neural progenitors migrate and form neurons after experimental traumatic brain injury
- 2009
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Ingår i: Restorative Neurology and Neuroscience. - Amsterdam : IOS Press. - 0922-6028 .- 1878-3627. ; 27:4, s. 323-334
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSENeural stem and progenitor cells (NSPC) generate neurons and glia, a feature that makes them attractive for cell replacement therapies. However, efforts to transplant neural progenitors in animal models of brain injury typically result in high cell mortality and poor neuronal differentiation.METHODSIn an attempt to improve the outcome for grafted NSPC after controlled cortical impact we transplanted Enhanced Green Fluorescent Protein (EGFP)-positive NSPC into the contra lateral ventricle of mice one week after injury.RESULTSGrafted EGFP-NSPC readily migrated to the injured hemisphere where we analyzed the proportion of progenitors and differentiated progeny at different time points. Transplantation directly into the injured parenchyma, resulted in few brains with detectable EGFP-NSPC. On the contrary, in more than 90% of the mice that received a transplant into the lateral ventricle detectable EGFP-positive cells were found. The cells were integrated into the lateral ventricle wall of the un-injured hemisphere, throughout the corpus callosum, and in the cortical perilesional area. At one-week post transplantation, grafted cells that had migrated to the perilesion area mainly expressed markers of neural progenitors and neurons, while in the corpus callosum and the ventricular lining, grafted cells with a glial fate were more abundant. After 3 months, grafted cells in the perilesion area were less abundant whereas cells that had migrated to the walls of the third- and lateral- ventricle of the injured hemisphere were still detectable, suggesting that the injury site remained a hostile environment.CONCLUSIONTransplantation to the lateral ventricle, presumably for being a neurogenic region, provides a favorable environment improving the outcome for grafted NSPC both in term of their appearance at the cortical site of injury, and their acquisition of neural markers.
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| 32. |
- Wallenquist, Ulrika, et al.
(författare)
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Ibuprofen attenuates the inflammatory response and allows formation of migratory neuroblasts from grafted stem cells after traumatic brain injury
- 2012
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Ingår i: Restorative Neurology and Neuroscience. - 0922-6028 .- 1878-3627. ; 30:1, s. 9-19
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: There is hope for neural stem and progenitor cells (NSPC) to enhance regeneration when transplanted to the injured brain after traumatic brain injury (TBI). So far, the therapeutic effects of NSPC transplantation have been hampered mainly by the notable death of the transplanted cells. Neuroinflammation may lead to additional cell death after TBI and we hypothesized that survival of grafted NSPC could be enhanced by anti-inflammatory treatment. Methods: Mice that were subjected to controlled cortical impact TBI and grafted with NSPC, were treated with the non-steroidal anti-inflammatory drug ibuprofen. Results: Ibuprofen was found to down-regulate the TBI-induced inflammatory response. In addition, migrating neuroblasts from transplanted cells were observed near the contusion and in the ipsilateral hippocampus in ibuprofen-treated animals only, suggesting that the anti-inflammatory treatment had beneficial effects on graft survival and/or differentiation. However, Morris Water Maze performance or TBI-induced tissue loss was not influenced by ibuprofen treatment. Conclusions: Our data suggests that anti-inflammatory strategies may be a complement to enhance the outcome for the cell transplants following TBI.
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| 33. |
- Wallenquist, Ulrika, 1975-
(författare)
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Neural Stem and Progenitor Cells as a Tool for Tissue Regeneration
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Neural stem and progenitor cells (NSPC) can differentiate to neurons and glial cells. NSPC are easily propagated in vitro and are therefore an attractive tool for tissue regeneration. Traumatic brain injury (TBI) is a common cause for death and disabilities. A fundamental problem following TBI is tissue loss. Animal studies aiming at cell replacement have encountered difficulties in achieving sufficient graft survival and differentiation. To improve outcome of grafted cells after experimental TBI (controlled cortical impact, CCI) in mice, we compared two transplantation settings. NSPC were transplanted either directly upon CCI to the injured parenchyma, or one week after injury to the contralateral ventricle. Enhanced survival of transplanted cells and differentiation were seen when cells were deposited in the ventricle. To further enhance cell survival, efforts were made to reduce the inflammatory response to TBI by administration of ibuprofen to mice that had been subjected to CCI. Inflammation was reduced, as monitored by a decrease in inflammatory markers. Cell survival as well as differentiation to early neuroblasts seemed to be improved. To device a 3D system for future transplantation studies, NSPC from different ages were cultured in a hydrogel consisting of hyaluronan and collagen. Cells survived and proliferated in this culturing condition and the greatest neuronal differentiating ability was seen in cells from the newborn mouse brain. NSPC were also used in a model of peripheral nervous system injury, and xeno-transplanted to rats where the dorsal root ganglion had been removed. Cells survived and differentiated to neurons and glia, furthermore demonstrating their usefulness as a tool for tissue regeneration.
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| 34. |
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| 35. |
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| 36. |
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| 37. |
- Xiong, Anqi, 1986-, et al.
(författare)
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Heparanase confers a growth advantage to differentiating murine embryonic stem cells, and enhances oligodendrocyte formation.
- 2017
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Ingår i: Matrix Biology. - : Elsevier BV. - 0945-053X .- 1569-1802. ; 62, s. 92-104
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Tidskriftsartikel (refereegranskat)abstract
- Heparan sulfate proteoglycans (HSPGs), ubiquitous components of mammalian cells, play important roles in development and homeostasis. These molecules are located primarily on the cell surface and in the pericellular matrix, where they interact with a multitude of macromolecules, including many growth factors. Manipulation of the enzymes involved in biosynthesis and modification of HSPG structures alters the properties of stem cells. Here, we focus on the involvement of heparanase (HPSE), the sole endo-glucuronidase capable of cleaving of HS, in differentiation of embryonic stem cells into the cells of the neural lineage. Embryonic stem (ES) cells overexpressing HPSE (Hpse-Tg) proliferated more rapidly than WT ES cells in culture and formed larger teratomas in vivo. In addition, differentiating Hpse-Tg ES cells also had a higher growth rate, and overexpression of HPSE in NSPCs enhanced Erk and Akt phosphorylation. Employing a two-step, monolayer differentiation, we observed an increase in HPSE as wild-type (WT) ES cells differentiated into neural stem and progenitor cells followed by down-regulation of HPSE as these NSPCs differentiated into mature cells of the neural lineage. Furthermore, NSPCs overexpressing HPSE gave rise to more oligodendrocytes than WT cultures, with a concomitant reduction in the number of neurons. Our present findings emphasize the importance of HS, in neural differentiation and suggest that by regulating the availability of growth factors and, or other macromolecules, HPSE promotes differentiation into oligodendrocytes.
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| 38. |
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| 39. |
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| 40. |
- Agreus, Lars, et al.
(författare)
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Towards a healthy stomach? : Helicobacter pylori prevalence has dramatically decreased over 23 years in adults in a Swedish community
- 2016
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Ingår i: United European Gastroenterology journal. - : Wiley. - 2050-6406 .- 2050-6414. ; 4:5, s. 686-696
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Tidskriftsartikel (refereegranskat)abstract
- Background In Western countries the prevalence of Helicobacter pylori (H. pylori) infection may be declining but there is a lack of recent longitudinal population studies. We evaluated the changing epidemiology over a 23-year period in Sweden.Materials and methods In 1989, the validated Abdominal Symptom Questionnaire (ASQ) was mailed to a random sample of inhabitants (ages 22-80 years) in a Swedish community, and 1097 (87%) responded. H. pylori serology was analysed in a representative subsample (n=145). Twenty-three years later, the ASQ was mailed again using similar selection criteria, and 388 out of 1036 responders had an upper endoscopy with assessment of H. pylori and corpus atrophy status.Results The prevalence of positive H. pylori serology decreased from 37.9% (1989) to 15.8% (2012), corresponding to a decrease in odds of 75% per decade (odds ratio (OR): 0.25; 95% confidence interval (CI): 0.11-0.59, p=0.001) independent of age, gender, body mass index (BMI) and level of education, with a pattern consistent with a birth cohort effect. The prevalence increased with increasing age (p=0.001). The prevalence of H. pylori on histology in 2012 was 11.4% (95% CI 8.6-15.0). The prevalence of corpus atrophy on serology and/or histology in 2012 was 3.2% (95% CI 1.8-5.5); all cases were 57 years old.Conclusion The stomach is healthier in 2012 compared with 1989. H. pylori prevalence in adults has decreased over the last two decades to a level where clinical management might be affected.
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