Effects of resveratrol on the proliferation and osteogenic differentiation of deciduous dental pulp stem cells from neurofibromatosis type 1 patient.

PURPOSE: We aimed at verifying whether resveratrol can decrease cell proliferation and change osteogenic differentiation of cells obtained from patients with type 1 neurofibromatosis (NF1). METHODS: Deciduous dental pulp derived stem cells were isolated from NF1 patient and healthy volunteer. These cells were subjected to increasing concentrations of resveratrol and evaluated for proliferation and mineralization of osteogenic differentiation. RESULTS: The results showed that resveratrol reduced the difference in proliferation between CNT and NF1 cells in a dose-dependent manner and this property was more prominent in affected cells than in healthy cells. Resveratrol showed no statistically significant changes in mineralization in osteogenic differentiation of NF1 cells, at low doses tested. CONCLUSIONS: In conclusion, in a dose-dependent manner, resveratrol displays interesting properties that could be applied in a possible treatment aimed at decreasing cellular proliferation in neurofibromatosis. Furthermore, it is selective concerning healthy cells and not affecting cell differentiation. Further research to cell selectivity, differentiation to other tissue types, and cell cytotoxicity are needed.

Proposing the use of dental pulp stem cells as a suitable biological model of neurofibromatosis type 1.

PURPOSE: This study aims to propose the dental pulp stem cells (DPSCs) as a model for studying two features related to neurofibromatosis type 1 (NF1), i.e. augmented proliferative capacity and altered osteogenic differentiation. METHODS: We isolated a DPSC from the pulp of deciduous teeth of a 6-year-old NF1 patient and two other healthy children of similar age. Cell proliferation was assayed by counting with a haemocytometer after successive cell re-plating. In order to compare osteogenic differentiation, we used osteoblast-differentiating medium and quantified alizarin stain, which relates to degree of calcification, and evaluated the expression of osteoblastic markers by reverse transcription polymerase chain reaction (RT-PCR). RESULTS: The DPSCs isolated from the NF1 patient displayed a greater rate of proliferation when compared to the control cells. Osteogenic differentiation occurred as expected for both NF1 and control, which concerned cell morphology and expression of osteoblast marker genes ALP, BMP2, BMP4, OCN and SPP1. However, alizarin staining denoted a markedly lower calcification level in the cells from the NF1-diagnosed child, considering that less calcium deposits were visualized under light microscopy and a smaller amount of alizarin could be quantified by spectrophotometry after extraction from the stained cells. CONCLUSION: DPSCs seem to be useful as a model for studying NF1 and predicting prognosis of patients, since their in vitro behaviour seems to mimic at least two features of this disorder: higher tendency to develop bone abnormalities and neoplastic cell proliferation.

Toward personalized cell therapies by using stem cells: seven relevant topics for safety and success in stem cell therapy.

Stem cells, both embryonic and adult, due to the potential for application in tissue regeneration have been the target of interest to the world scientific community. In fact, stem cells can be considered revolutionary in the field of medicine, especially in the treatment of a wide range of human diseases. However, caution is needed in the clinical application of such cells and this is an issue that demands more studies. This paper will discuss some controversial issues of importance for achieving cell therapy safety and success. Particularly, the following aspects of stem cell biology will be presented: methods for stem cells culture, teratogenic or tumorigenic potential, cellular dose, proliferation, senescence, karyotyping, and immunosuppressive activity.

Advances in cellular technology in the hematology field: What have we learned so far?

Despite the advances in the hematology field, blood transfusion-related iatrogenesis is still a major issue to be considered during such procedures due to blood antigenic incompatibility. This places pluripotent stem cells as a possible ally in the production of more suitable blood products. The present review article aims to provide a comprehensive summary of the state-of-the-art concerning the differentiation of both embryonic stem cells and induced pluripotent stem cells to hematopoietic cell lines. Here, we review the most recently published protocols to achieve the production of blood cells for future application in hemotherapy, cancer therapy and basic research.

Intestinal microbiota as modulators of the immune system and neuroimmune system: impact on the host health and homeostasis.

Many immune-based intestinal disorders, such as ulcerative colitis and Crohn's disease, as well as other illnesses, may have the intestines as an initial cause or aggravator in the development of diseases, even apparently not correlating directly to the intestine. Diabetes, obesity, multiple sclerosis, depression, and anxiety are examples of other illnesses discussed in the literature. In parallel, importance of the gut microbiota in intestinal homeostasis and immunologic conflict between tolerance towards commensal microorganisms and combat of pathogens is well known. Recent researches show that the immune system, when altered by the gut microbiota, influences the state in which these diseases are presented in the patient directly and indirectly. At the present moment, a considerable number of investigations about this subject have been performed and published. However, due to difficulties on correlating information, several speculations and hypotheses are generated. Thus, the present review aims at bringing together how these interactions work-gut microbiota, immune system, and their influence in the neuroimmune system.

Satellite cells: regenerative mechanisms and applicability in muscular dystrophy.

The satellite cells are long regarded as heterogeneous cell population, which is intimately linked to the processes of muscular recovery. The heterogeneous cell population may be classified by specific markers. In spite of the significant amount of variation amongst the satellite cell populations, it seems that their activity is tightly bound to the paired box 7 transcription factor expression, which is, therefore, used as a canonical marker for these cells. Muscular dystrophic diseases, such as Duchenne muscular dystrophy, elicit severe tissue injuries leading those patients to display a very specific pattern of muscular recovery abnormalities. There have been works on the application of precursors cells as a therapeutic alternative for Duchenne muscular dystrophy and initial attempts have proven the cells inefficient; however later endeavours have proposed solutions for the experiments improving significantly the results. The presence of a range of satellite cells populations indicates the existence of specific cells with enhanced capability of muscular recovery in afflicted muscles.

Mesenchymal stem cells derived from human exfoliated deciduous teeth (SHEDs) induce immune modulatory profile in monocyte-derived dendritic cells.

BACKGROUND: Mesenchymal stem cells have prominent immune modulatory properties, which may have clinical applications; however their major source, bone marrow, is of limited availability. On the other hand, mesenchymal stem cells derived from human exfoliated deciduous teeth (SHEDs) are readily accessible, but their immune regulatory properties have not been completely investigated. This study was designed, therefore, to evaluate the SHEDs influence on DCs differentiation, maturation, ability to activate T cells and to expand CD4(+)Foxp3(+) T cells. METHODOLOGY/PRINCIPAL FINDINGS: The experiments were based in cellular co-culture during differentiation and maturation of monocyte derived-DCs (moDCs), with, or not, presence of SHEDs. After co-culture with SHEDs, (moDCs) presented lower expression of BDCA-1 and CD11c, in comparison to DC cultivated without SHEDs. CD40, CD80, CD83 and CD86 levels were also decreased in mature DCs (mDCs) after co-cultivation with SHEDs. To assess the ability of SHEDs-exposed moDCs to modulate T cell responses, the former were separated from SHEDs, and co-cultured with peripheral blood lymphocytes. After 5 days, the proliferation of CD4(+) and CD8(+) T cells was evaluated and found to be lower than that induced by moDCs cultivated without SHEDs. In addition, an increase in the proportion of CD4(+)Foxp3(+)IL-10(+) T cells was observed among cells stimulated by mature moDCs that were previously cultivated with SHEDs. Soluble factors released during co-cultures also showed a reduction in the pro-inflammatory cytokines (IL-2, TNF-α and IFN-γ), and an increase in the anti-inflammatory molecule IL-10. CONCLUSION/SIGNIFICANCE: This study shows that SHEDs induce an immune regulatory phenotype in moDCs cells, evidenced by changes in maturation and differentiation rates, inhibition of lymphocyte stimulation and ability to expand CD4(+)Foxp3(+) T cells. Further characterization and validation of this phenomenon could support the use of SHEDs, directly or indirectly for immune modulation in the clinical practice.