Journal: Stem cell reviews
In a recent study published in this journal it was claimed that the rate of publications from US-based authors in the human embryonic stem cell (hESC) research field was slowing or even declining from 2008 to 2010. It was assumed that this is the result of long-term effects of the Bush administration’s funding policy for hESC research and the uncertain policy environment of recent years. In the present study, we analyzed a pool of more than 1,700 original hESC research papers published world-wide from 2007 to 2011. In contrast to the previous study, our results do not support the hypothesis of a decline in the productivity of US-based research but rather confirm a nearly unchanged leading position of US research in the hESC field with respect to both publication numbers and impact of research. Moreover, we analyzed about 500 papers reporting original research involving human induced pluripotent stem cells (hiPSCs) published through 2011 and found a dominant position of US research in this research field as well.
We researched the survival of bone marrow-derived mesenchymal stem cells (MSCs) and the results of MSCs' injected into decompensated bladders in a rabbit model.
Evaluation of potential tropic effects of vascular endothelial growth factor (VEGF) on the incorporation and differentiation of bone-marrow-derived stem cells (BMSCs) in a murine model of anterior ischemic optic neuropathy (AION).
Hematopoietic stem cells (HSCs) from umbilical cord blood have been successfully used to treat blood disorders but one major hurdle is the relatively low cell dose available. Double cord blood unit transplantation results in elevated engraftment failure because one unit predominates over the other. Various approaches are thus being undertaken to expand HSCs ex vivo from single cord blood units. We report here a protocol involving slow freezing (-1 °C per minute to -120 °C) + freezing medium containing DMSO + FBS + 24 h-50 % hWJSC-CM that enhances thaw-survival of CD34+ cells. Post-thawing, the fold, percentage and colony forming unit numbers of CD34+ cells were significantly increased (2.08 ± 0.3; 102 ± 1.17 %; 1.07 ± 0.02 respectively) while the percentages of apoptotic, necrotic, dead and sub-G1 phase cells (91.06 ± 3.63 %; 91.80 ± 5.01 %; 95.6 ± 3.61 %; 86.1 ± 16.26 % respectively) were significantly decreased compared to controls. Post-thaw culture in 24 h-50 % hWJSC-CM+FBS for 72 h showed further significant increases in CD34+ cells (fold: 2.28 ± 0.17; percentage: 153.3 ± 21.99 %, CFU: 1.6 ± 0.19) and significant decreases in apoptotic, necrotic, dead and sub-G1 cells (49.2 ± 3.59 %; 62.0 ± 4.30 %; 56.6 ± 5.06 %; 28.6 ± 5.74 % respectively) compared to controls. We hypothesize that these improvements are probably related to the high levels of cytokines, cell adhesion molecules and growth factors in hWJSC-CM that help to preserve cell membrane integrity during freezing and stimulate mitosis post-thaw. A 24 h-50 % hJWSC-CM may be a useful supplement for freezing CD34+ cells in cord blood banks.
Stem cell research has generated considerable attention for its potential to remediate many disorders of the central nervous system including neurodevelopmental disorders such as autism spectrum disorder (ASD) and cerebral palsy (CP) that place a high burden on individual children, families and society. Here we characterized messaging about the use of stem cells for ASD and CP in news media articles and concurrent dissemination of discoveries through conventional science discourse. We searched LexisNexis and Canadian Newsstand for news articles from the US, UK, Canada and Australia in the period between 2000 and 2014, and PubMed for peer reviewed articles for the same 10 years. Using in-depth content analysis methods, we found less cautionary messaging about stem cells for ASD and CP in the resulting sample of 73 media articles than in the sample of 87 science papers, and a privileging of benefits over risk. News media also present stem cells as ready for clinical application to treat these neurodevelopmental disorders, even while the science literature calls for further research. Investigative news reports that explicitly quote researchers, however, provide the most accurate information to actual science news. The hope, hype, and promise of stem cell interventions for neurodevelopmental disorders, combined with the extreme vulnerability of these children and their families, creates a perfect storm in which journalists and stem cell scientists must commit to a continued, if not even more robust, partnership to promote balanced and accurate messaging.
Transparent public discourse about translational stem cell research promotes informed hope about scientific progress and the sustainable development of biotechnologies. Using an a priori coding scheme, we surveyed articles from leading news media about stem cell interventions for neurodegenerative diseases (1991-2014) from United States (n = 83), Canada (n = 29), and United Kingdom (n = 65). While, this analysis of translational contexts in the news demonstrates a lingering tendency to celebrate the benefits of research with little context of its caveats even for chronic neurologic diseases, in a departure from many previous studies, the data also reveal conscientious reporting about stem cell tourism and timeframe estimates for the development of relevant therapeutics.
Stem cell fate is largely determined by the microenvironment called niche. The extracellular matrix (ECM), as a key component in the niche, is responsible for maintaining structural stability and regulating cell proliferation, differentiation, migration and other cellular activities. Each tissue has a unique ECM composition for its needs. Here we investigated the effect of a bioengineered human dermal fibroblast-derived ECM (hECM) on the regulation of human mesenchymal stem cell (hMSC) proliferation and multilineage differentiation. Human MSCs were maintained on hECM for two passages followed by the analysis of mRNA expression levels of potency- and lineage-specific markers to determine the capacity of MSC stemness and differentiation, respectively. Mesenchymal stem cells pre-cultured with or without hECM were then induced and analyzed for osteogenesis, adipogenesis and chondrogenesis. Our results showed that compared to MSCs maintained on control culture plates without hECM coating, cells on hECM-coated plates proliferated more rapidly with a higher percentage of cells in S phase of the cell cycle, resulting in an increase in the CD90(+)/CD105(+)/CD73(+)/CD45(-) subpopulation. In addition, hECM downregulated osteogenesis and adipogenesis of hMSCs but significantly upregulated chondrogenesis with increased production of collagen type 2. In sum, our findings suggest that hECM may be used to culture hMSCs for the application of cartilage tissue engineering.
Duchenne Muscular Dystrophy (DMD) is a progressive and lethal disease caused by mutations of the dystrophin gene. Currently no cure exists. Stem cell therapies targeting DMD are challenged by limited engraftment and rejection despite the use of immunosuppression. There is an urgent need to introduce new stem cell-based therapies that exhibit low allogenic profiles and improved cell engraftment. In this proof-of-concept study, we develop and test a new human stem cell-based approach to increase engraftment, limit rejection, and restore dystrophin expression in the mdx/scid mouse model of DMD. We introduce two Dystrophin Expressing Chimeric (DEC) cell lines created by ex vivo fusion of human myoblasts (MB) derived from two normal donors (MBN1/MBN2), and normal and DMD donors (MBN/MBDMD). The efficacy of fusion was confirmed by flow cytometry and confocal microscopy based on donor cell fluorescent labeling (PKH26/PKH67). In vitro, DEC displayed phenotype and genotype of donor parent cells, expressed dystrophin, and maintained proliferation and myogenic differentiation. In vivo, local delivery of both DEC lines (0.5 × 106) restored dystrophin expression (17.27%±8.05-MBN1/MBN2and 23.79%±3.82-MBN/MBDMD) which correlated with significant improvement of muscle force, contraction and tolerance to fatigue at 90 days after DEC transplant to the gastrocnemius muscles (GM) of dystrophin-deficient mdx/scid mice. This study establishes DEC as a potential therapy for DMD and other types of muscular dystrophies.
Stem cells continue to garner attention by the news media and play a role in public and policy discussions of emerging technologies. As new media platforms develop, it is important to understand how different news media represents emerging stem cell technologies and the role these play in public discussions. We conducted a comparative analysis of newspaper and sports websites coverage of one recent high profile case: Gordie Howe’s stem cell treatment in Mexico. Using qualitative coding methods, we analyzed news articles and readers' comments from Canadian and US newspapers and sports websites. Results indicate that the efficacy of stem cell treatments is often assumed in news coverage and readers' comments indicate a public with a wide array of beliefs and perspectives on stem cells and their clinical efficacy. Media coverage that presents uncritical perspectives on unproven stem cell therapies may create patient expectations, may have an affect on policy discussions, and help to feed the marketing of unproven therapies. However, news coverage that provides more balanced or critical coverage of unproven stem cell treatments may also inspire more critical discussion, as reflected in readers' comments.
Neuronal degeneration within the substantia nigra and the loss of the dopaminergic nigro-striatal pathway are the major hallmarks of Parkinson’s disease (PD). Grafts of foetal ventral mesencephalic (VM) dopaminergic (DA) neurons into the striatum have been shown to be able to restore striatal dopamine levels and to improve overall PD symptoms. However, human foetus-derived cell grafts are not feasible for clinical application. Autologous induced pluripotent stem cell (iPS cell)-derived DA neurons are emerging as an unprecedented alternative. In this review, we summarize and compare the efficacy of human iPS cell-derived DA neuron grafts to restore normal behaviour in a rat model for PD with that of human foetal primary DA neurons. The differences we observed in the efficacy to restore normal function between the 2 types of DA neuron grafts could be ascribed to intrinsic properties of the iPS cell-derived DA neurons that critically affected survival and proper neurite extension in the striatum after implantation.