Full text
| |
| Author(s): |
Mayra Laino Albiero
Total Authors: 1
|
| Document type: | Master's Dissertation |
| Press: | Piracicaba, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Faculdade de Odontologia de Piracicaba |
| Defense date: | 2013-05-03 |
| Examining board members: |
Karina Gonzales Silverio;
Thaisângela Rodrigues;
Bruna Rabelo Amorim
|
| Advisor: | Karina Gonzales Silverio |
| Abstract | |
The aim of this study was to evaluate if the exposure of mesenchymal stem cells of the periodontal ligament (PDLMSCs) to lipopolysaccharide (LPS) of Porphyromonas gingivalis (Pg) and Escherichia coli (Ec), would lead to biological changes that compromised the properties related to undifferentiated mesenchymal phenotype. To test this hypothesis, initially it was checked whether the five populations of mesenchymal stem cells purified by surface antigen CD105 (CD105+ cells) expressed the Toll-like receptors 2 and 4 (TRL2 and 4). Then, cells were cultured in the presence of LPS from Pg and Ec, and evaluated for viability and proliferation by the MTS assay, expression of proinflammatory cytokines IL-1?, IL-6, IL-8 and TNF-? (PCRq technique), immunostaining for STRO-1 and OCT-4 gene expression, an identifier of pluripotency, and osteoblast/cementoblastic differentiation capacity through assays to identify minerals nodules, as well as the gene expression of RUNX2, ALP and OCN. All these assays were carried out also in the presence of LPS from Escherichia coli (Ec), which is not considered a periodontal pathogen. The results showed that all cell populations with undifferentiated mesenchymal phenotype had positive staining for STRO-1, and also showed to be positive for the receptors TLR2 and 4. The MTS assay revealed that exposure to the three concentrations of Pg and Ec LPS (100 ng, 1?g and 10?g/ml) did not affect cell viability, keeping all PDLMSCs populations proliferative over 10 days of culture. In parallel, it was found that the LPS Pg did not alter mRNA levels for the cytokines studied, while the Ec LPS caused a significant increase in IL-6 and IL-8, when applied concentrations of 100ng/ml and 1?g/ ml. Additionally, the results revealed that cellular exposure to both LPS in the concentration of 1?g/ml, did not alter the undifferentiated mesenchymal phenotype of these populations, since the expression of gene OCT-4 and positive STRO-1 staining remained similar to cells in the control group. In addition, these cells retained their ability to differentiate into osteoblastic/cementoblastic phenotype confirmed by production of mineral nodules (alizarin red assay) and expression of the genes for RUNX-2, ALP and OCN similar to cells control group (cultured in osteogenic medium only). It was only observed a significant increase (p<0.05) in the production of mineral nodules when cells were cultured in the presence of 1?g/ml Ec LPS. However, this increase in the mineral matrix it is not related to increased levels of mRNA for genes related to osteogenic phenotype compared to the control group. Within the experimental conditions, it can be concluded that exposure of PDLMSCs to LPS of Porphyromonas gingivalis and Escherichia coli did not alter the biological properties of these cells thereby, maintaining the characteristics that confer to these cells the condition of mesenchymal stem cells (AU) | |
| FAPESP's process: | 11/04757-3 - Effect of LPS from porphyromonas gingivalis on the biological properties of mesenchymal stem cells from human periodontal ligament |
| Grantee: | Mayra Laino Albiero |
| Support Opportunities: | Scholarships in Brazil - Master |