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Tissue engineering gives new tools for stem cell-based regenerative medicine and in vitro toxicology. Among different sources of stem cells human cord and cord blood are safe, clinically and ethically approved and easily obtainable sources of pluripotent stem cells able to differentiate into many tissues originated from 3 germ layers. Recently we showed that functional artifi cial neural tissue can be generated from pluripotent stem cells derived from freshly isolated human cord and cord blood stem cells in fully-defi ned culture conditions. We showed that cell starving and precise sequential introduction of single growth factors and morphogenes resulted in differentiation of pluripotent stem cells towards mature neurons in scaffold-based three-dimensional environment. The pluripotent stem cells decreased expression of the key pluripotency transcription factors: Oct4A, Sox2, Nanog, c-Myc, and acquired phenotypes of neuroblasts (Nestin+/GFAP+) followed by generation of mature neuronal networks (NeuN+, PSD95+, TUJ1+, S100beta). Finally we showed that cell–cell interactions within the 3D environment of artifi cial neural tissue were crucial for functional, electrical and calcium, activity of neural networks in vitro. We conclude that tissue-engineering approach is important for generation of functional neural tissue in vitro from cord and cord blood stem cells and therefore might be useful for future therapies of central nervous system.
Taking tissue engineering applications into clinical trials requires the development of efficient and safe protocols incorporated with effective 3-dimentional cell culturing and differentiation systems in order to develop transplantable tissues that may offer a life-line for patients in the future. Cord blood, which is perhaps the most abundant world stem cell source, has shown previously practical and ethical advantages over other stem cells sources in many research and clinical applications including regenerative medicine. We previously developed a three-step protocol for isolation, expansion and sequential neuronal differentiation of cord blood pluripotent stem cells (characterized with our unique triple immunocytochemisty scheme for Oct-4, Sox-2 and Nanog) in defined serum-free culturing conditions. In this study we incorporated this protocol with 3-dimentional culturing systems which produced artificial neuronal tissues expressing Nestin, NF-200, TUJ1, PSD-95 and NeuN. We showed that cord blood pluripotent stem cells are a potential and promising candidate for future neural tissue engineering and regenerative medicine.
Taking tissue engineering applications into clinical trials requires the development of effi cient, effective and safe protocols incorporated with effective 3-dimentional cell culturing and differentiation systems in order to develop transplantable tissues that may offer a life-line for many patients in the future. Umbilical cord blood, which is perhaps the most abundant world stem cell source, has shown previously practical and ethical advantages over other stem cells sources in many research and clinical applications including regenerative medicine. We developed a three step protocol for isolation, expansion and sequential neuronal differentiation and maturation of cord blood pluripotent stem cells (characterized with our unique triple immunocytochemisty scheme for Oct-4, Sox-2 and Nanog expression) in serum-free defi ned culturing conditions. We incorporated this protocol with 3-dimentional culturing system which produced properly organized neuronal tissues expressing Nestin and NF-200. We showed that umbilical cord blood pluripotent stem cells are a potential and promising candidate for future neural tissue engineering and regenerative medicine applications.
Mesenchymal stem cells (MSC) are of clinical interest because of their potential use in autologous transplantation. The ability of MSC to differentiate into multiple different cells of mesodermal origin has offered therapeutic tool for the treatment of hematopoietic malignancies and graft versus host disease. Recently, MSC have been shown to ameliorate a variety of neurological dysfunction. This effect is believed to be mediated to their paracrine functions since it is known that MSC produce bioactive substances that promote endogenous neurogenesis. However, the critical question that remains unanswered is whether MSC can transdifferentiate into neural cells. To be “primed” toward a neuronal fate, MSC have to express neural antigens. In an attempt to clarify this issue we explored the constitutive expression of different markers by mesenchymal cells isolated from human umbilical cord Wharton jelly (HUC-MSC) and compare their expression with neural stem cell line derived from human umbilical cord blood (HUCB-NSC) established in our laboratory. Materials and methods: Gene expression pattern in HUC-MSC (passage 5 of cells cultured in MSCGM hMSC Lonza medium) and HUCB-NSC (cultured in DMEM/F12 medium+2% FBS) was performed by real time PCR and RT-PCR reactions. Total RNA was extracted using TRIzol (Invitrogen). Then cDNA was synthesized from total RNA, using High Capacity RNA-to-cDNA kit (Applied Biosystems). PCR reactions were carried out using template cDNA in the presence of specific primers. Concomitantly immunocytochemical analysis of gene-related proteins was employed. The results of our studies have demonstrated that HUC-MSC, in addition to pluripotent (Oct3/4, Nanog1), mesenchymal (CD73, CD90, CD105, CD166) and extracellular matrix (Fibronectin, Vimentin, Collagen1) genes, spontaneously express neural genes i.e. Nestin, NF200, βIIITubulin, MAP2 and GFAP. The initially expressed neuroectodermal genes were comparable with mRNA level of the same neural genes in HUCB-NSC. In addition to neural genes noninduced expression of neural proteins was found. Subsets of HUCMSC were positive for several neural markers, including: Nestin, NF200, βIIITubulin and GFAP. Summary and conclusion: We have demonstrated that MSC derived from human umbilical cord Wharton jelly acquire neural progenitor-like properties by expressing neuronal and astrocytic specific markers. However, it is of clinical interest whether transplanted MSC respond with an appropriate neural pattern of differentiation when exposed to the environment of the host brain. Supported by MSHE grant no N401 014235 and Foundation Jerome Lejeune grant as part of the Novus Sanguis research consortium.
Mesenchymal stem cells (MSC) emerged as promising candidates for therapeutic applications in regenerative medicine and tissue engineering. The ability of MSC to differentiate into multiple different cells of mesodermal origin has offered therapeutic tool for the treatment leukaemias and other malignant diseases. Recently, MSC have been shown to ameliorate a variety of neurological dysfunction. The critical question that remains unanswered is whether MSC can trans-differentiate into neural cells. In an attempt to clarify this issue we explored the expression profile of different markers by mesenchymal cells isolated from human umbilical cord Wharton jelly (HUC-MSC) and compare their expression with neural stem cell line derived from human umbilical cord blood (HUCB-NSC) established in our laboratory. Materials and methods: Gene expression pattern in HUC-MSC (hMSC Lonza medium) and HUCB-NSC (DMEM/F12 medium+2% FBS) was performed by RT-PCR and quantitative RT-PCR reactions. Total RNA was isolated from cultured cells and RT-PCR was performed by using gene-specific primers. The target gene value of each sample was normalized by the GAPDH value. Concomitantly immunocytochemical analysis of gene-related proteins was employed. Results: Direct comparison of the expression profiles demonstrated that HUC-MSC, in addition to pluripotent (Oct-4, Nanog) genes, spontaneously express neural genes: Nestin, NF-200, βIIITubulin, and GFAP. Concomitantly non-induced expression of neural proteins was found. The subsets of HUC-MSC were positive for several markers including: SSEA-4, Nestin, NF-200, βIIITubulin, GFAP and A2B5. Summary and conclusions: We have demonstrated that MSC derived from human umbilical cord Wharton jelly cultured in vitro acquire neural progenitor-like properties by expressing neuronal and astrocytic specific markers. Supported by MSHE grant No. N401 014235 and Foundation Jerome Lejeune grant as part of the Novus Sanguis research consortium.
Over the last decade a large number of studies explored the use of cord-blood-derived stem cells for treatment of neurological disorders. Despite of some positive preclinical results low survival of transplanted cells was noticed in the host brain. It seems that transplantation of the donor cells in their own milieu might be more effective due to the natural cell-cell contact and the presence of growth factors and cytokines. The concept of our studies was to deliver human stem cells resided in Wharton jelly (WJ) of umbilical cord tissue into rat brain. 3D tissue implant contains mesenchymal stem cells (MSCs) capable of multilineage differentiation. In the current study we performed in situ analysis of entire WJ-MSCs after their transplantation into: hippocampal organotypic slices isolated from neonatal rats (i); the striatum of normal (ii) or focally injured (iii) adult Wistar rats. Results: Seven days after grafting on hippocampal slices intense migration of the donor cells (NuMa+) from 3D WJ implant was noticed. Double-labeling showed co-localization of NuMa marker with NF200 or GFAP activity in these cells whereas donor cells residing in 3D WJ implant did not express any neural markers. Interestingly, in intact brain all WJ-MSCs (NuMa+) cells remained in 3D tissue implant but differentiated into NF200+ and GFAP+ phenotypes during the time of observation. In contrast, after WJ implantation into injured rat brain the donor MSCs proclaimed migration towards ischemic boundary regions. Moreover, NF200 or GFAP markers were localized among both, migrating as well as remaining in the graft NuMa+ cells. Conclusions: Transplantation of WJ-MSCs in 3D tissue implant into adult rat brain improves cells survival within graft and induces their spontaneous transition into cell of neural lineage. Brain injury additionally stimulates migration of these donor cells out of WJ implant with their further differentiation in the host tissue. Supported by Fondation Jerome Lejeune grant
Surprisingly in vitro conditions allowing to culture glioblastoma cells presenting EGFR amplification were not known until now. Our evaluation of EGFR amplification status in glioblastoma (GBM) culture demonstrated that this anomaly was preserved for months in spheroids (aggregated glioblastoma cells) at a level comparable to the earliest passage of cell culture. In contrast, and in accordance with already published data we detected it as completely lost in the adherent culture. Apparently glioblastoma cells presenting EGFR amplification become apoptotic in the regular cell culture conditions. In addition discrepant expression of SOX2 and multilineage phenotype recognized as a markers of neural progenitors was observed in monolayer and 3D culture. Moreover, our analyses showed a decreased invasion potential of adherent GBM loosing EGFR amplification, and spheroids maintaining EGFR amplification. In conclusion, our findings confirm that GBM-derived spheroids seem to be a promising tool to preserve original molecular features of the tumor in vitro, with a special emphasis on EGFR gene aberrations, including EGFRvIII, regarded as novel therapeutic target. Our last unpublished and preliminary data suggest that mechanism responsible for in vitro death of adherent glioblastoma cells showing EGFR amplification seems to be linked to the artificial in vitro cell-cell interaction rather than to the lack of proper autocrine effects. Those suggestion came from analysis of glioblastoma cells in artificial brain tissues system and analysis of aggregated glioblastoma cells only. The present study was supported by the Ministry of Science and Higher Education, Poland, grant No. N N401047337 and Foundation for Polish Science(PARENT-BRIDGE Programme - support for women, No.POMOST_C/15).
Mesenchymal stem cell (MSC) transplantation offers new therapeutic avenue for neurological diseases, however limitted survival of exogenous cells in the host brain is a major setback. The aim of this study was to evaluate the efficacy of using biodegradable scaffolds or Wharton jelly implants contained MSC after their transplantation into rat brain.Materials and methods: Adult Wistar rats were transplanted with MSC derived from human umbilical cord (hUC-MSC) (i), hUC-MSC localized inside biodegradable gelatin/laminin scaffolds (hUC-MSC/GL) (ii) or Wharton jelly implants (hUC-MSC/WJ) (iii). Results: hUC-MSC cultured in vitro expressed CD73, CD90, CD166 and Oct3/4, Nanog1, Nestin markers. 7 days after hUC-MSC transplantation only few viable donor cells were observed in the rat brain surrounded by heavy infiltration of macrophages/microglia (ED1+) and activating astrocytes (GFAP+). Hence transplantation of hUC-MSC/GL resulted with better cell survival compared with hUCMSC grafted in suspension. There was no donor cell migration out of the scaffolds however hUC-MSC lodged inside G/L scaffolds attained early neural markers. The inflammatory cell influx observed around the scaffolds was less intense with few ED1+ cells present in the core of scaffold. Similarly, all transplanted hUC-MSC/WJ remained in 3D tissue implants. Some of these cells adopted NF200, A2B5 or GFAP phenotypes during 7 days of observation. Concomitantly only scarce infiltration of immunoreactive cells was seen. Conclusions: Transplantation of hUC-MSC in 3D G/L scaffolds or hUC-MSC/WJ implants into adult rat brain improves survival of donor cells and induces their spontaneous transition into cell of neural lineage. It seems that 3D structures protect cells localized inside them from the host immune cells and may allow the diffusion of nutrients and other factors to propagate cell survival and differentiation into neuronal lineage. Supported by MSHE grant no N401 014235 and Fondation Jerome Lejeune grant.
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