Characterization of progenitor/stem cell population from human dental socket and their multidifferentiation potential.

Dental stem cells have many applications in medicine, dentistry and stem cell biology in general due to their easy accessibility and low morbidity. A common surgical manoeuvre after a tooth extraction is the dental socket curettage which is necessary to clean the alveolus and favour alveolar bone healing. This procedure can cause very low morbidity compared to bone marrow collection procedures and the collected material is normally discarded. In order to investigate if the tissue obtained by dental socket curettage after a tooth extraction was a feasible alternative source to isolate human stem cells, we isolated and characterized two different stem cell populations based on STRO-1 and CD146 expression. We were able to collect and grow cells from dental socket of vital and non-vital teeth. Both populations were proliferative, clonogenic and expressed STRO-1, CD146, CD90, NG2, PDGFR-ß, which are markers found in stem cells, presented in vitro multiline-differentiation into osteogenic, chondrogenic, and adipogenic tissue, and in vivo transplanted cells formed mineralized tissue. Interestingly, STRO-1+ clonogenic cells presented better multidifferentiation than CD146+ cells. Our results showed that mesenchymal stem cells can be isolated from the tiny tissue collected by dental socket curettage after vital and non-vital tooth extraction and suggest that STRO-1 is an important marker to be used to sort cells with multidifferentiation capacity.

Comparative prognostic relevance of breast intra-tumoral microvessel density evaluated by CD105 and CD146: A pilot study of 42 cases.

UNLABELLED: Angiogenesis is a key process for metastatic progression. While it has been established that the evaluation of breast tumoral microvessel density by CD105 marker is a potential prognostic parameter, its evaluation by CD146 marker has been poorly studied. AIM: The purpose of this study was to compare the prognostic value of intra-tumoral microvessel density assayed by CD105 and CD146 in early breast cancer patients. METHODS: 42 women with breast infiltrative ductal carcinoma (I and II-stages) were retrospectively reviewed. Intra-tumoral microvessel density was immunohistochemically examined using antibodies anti-CD105 and CD146 in paraffin-embedded tissues, and their association with classical prognostic-markers, metastatic recurrence, metastasis-free survival and overall survival was analyzed. RESULTS: High microvessel density assessed by CD146 was significantly associated with a higher risk of developing metastasis (p=0.0310) and a shorter metastasis-free survival (p=0.0197). In contrast, when we used the CD105-antibody, we did not find any significant association. Finally, CD146 showed to be an independent predictive indicator for metastasis-free survival (p=0.0055). CONCLUSION: Our data suggest that the intra-tumoral microvessel density evaluated by CD146 may be a more suitable predictor of metastatic development than that evaluated by CD105 in early breast cancer.

Mesenchymal stem cells as active prohealing and immunosuppressive agents in periapical environment: evidence from human and experimental periapical lesions.

INTRODUCTION: Previous studies describe contrasting molecular profiles of active and inactive periapical granulomas characterized by distinct expression of cytokines, osteoclastogenic factors, and wound healing markers. Although the molecular mechanisms underlying such a dichotomy remain unknown, in this study we investigated the potential involvement of mesenchymal stem cells (MSCs) in determining human and murine periapical lesion activity and outcomes. METHODS: Periapical granulomas (n = 83) and control samples (n = 24) were comparatively assessed for the expression levels of 11 mesenchymal stem cell (MSC) markers using real-time polymerase chain reaction. Experimental periapical lesions induced in mice were evaluated for MSC marker expression and the effects of AMD3100 treatment on lesion outcomes. RESULTS: MCS marker expression was prevalent in periapical granulomas compared with that in controls, whereas CD29, CD73, CD90, CD146, CD166, NANOG, Stro-1, and CXCR4 expressions were higher in inactive than in active lesions. Experimental periapical lesion inactivity was also associated with an increased expression of MSC markers. The inhibition of MSC mobilization to the periapex by AMD3100 resulted in increased lesion sizes; decreased expression of MSCs and wound healing markers; and increased expression of interleukin 1 beta (IL-17ß), interleukin 17 (IL-17), tumor necrosis factor alpha (TNF-α), interferon gamma (IFN-γ), and nuclear factor kappa-B ligand (RANKL). CONCLUSIONS: Our results show that MSC markers are overexpressed in inactive human and experimental periapical lesions and that MSC mobilization results in the attenuation of experimental lesion progression associated with immunosuppressive and prohealing mechanisms.