Artículos Científicos año 2016

Does Cryopreservation Affect the Biological Properties of Stem Cells from Dental Tissues? A Systematic Review. Conde MC, Chisini LA, Grazioli G, Francia A, Carvalho RV, Alcázar JC, Tarquinio SB, Demarco FFBraz Dent J. 2016 Oct-Dec;27(6):633-640.

Abstract

This systematic review evaluated if different cryopreservation protocols could affect biological properties (Cell survival rate (CSR), proliferation, differentiation, maintenance of stem cell markers) of stem cells obtained from dental tissues (DSC) post-thaw. An electronic search was carried out within PubMed and ISI Web Science by using specific keyword. Two independent reviewers read the titles and abstracts of all reports respecting predetermined inclusion/exclusion criteria. Data were extracted considering the biological properties of previously cryopreserved DSCs and previously cryopreserved dental tissues. DSCs cryopreserved as soon as possible after their isolation presents a CSR quite similar to the non-cryopreserved DSC. Dimethyl sulfoxide (DMSO) [10%] showed good results related to cell recovery post-thaw to cryopreserve cells and tissues for periods of up to 2 years. The cryopreservation of DSC in a mechanical freezer (-80°C) allows the recovery of stem cells post-thaw. The facilities producing magnetic field (MF), demand a lower concentration of cryoprotectant, but their use is not dispensable. It is possible to isolate and cryopreserve dental pulp stem cell (DPSC) from healthy and diseased vital teeth. Cryopreservation of dental tissues for late DSC isolation, combined with MF dispensability, could be valuable to reduce costs and improve the logistics to develop teeth banks.

https://www.ncbi.nlm.nih.gov/pubmed/27982171/

In vivo performance of different scaffolds for dental pulp stem cells induced for odontogenic differentiation. Atalayin C, Tezel H, Dagci T, Karabay Yavasoglu NU, Oktem G, Kose T. Braz Oral Res. 2016 Nov 28;30(1)

Abstract

This study was designed to determine the in vivo performance of three different materials as scaffolds for dental pulp stem cells (DPSC) undergoing induced odontogenic differentiation. An odontogenic medium modified by the addition of recombinant human bone morphogenetic protein 2 was used in the experimental groups to induce differentiation. Mesenchymal stem cell medium was used in the control groups. DPSC were transplanted onto the backs of mice via three scaffolds: copolymer of L-lactide and DL-lactide (PLDL), copolymer of DL-lactide (PDL) and hydroxyapatite tricalcium phosphate (HA/TCP). The expression levels of dentin sialo-phosphoprotein (DSPP), dentin matrix protein-1 (DMP1), enamelysin/matrix metalloproteinase 20 (MMP20) and phosphate-regulating gene with homologies to endopeptidases on X chromosome (PHEX) were analysed using RT-PCR. The expressions in the experimental groups were compared to those in the control groups. The transcript expressions at 6 and 12 weeks were significantly different for all scaffolds (p < 0.05), except for the expression of DSPP in the PLDL group with regard to the time variable. Although there was a decrease in the expression of enamelysin/MMP20 in PLDL and HA/TCP at 12 weeks, all other expressions increased and reached their highest level at 12 weeks. The highest DSPP expression was in the PDL group (p < 0.05). The highest expression of DMP1 was detected in the HA/TCP group (p < 0.05). The highest expression of PHEX was in the PLDL group (p < 0.05). Consequently, PLDL and PDL seemed to be promising scaffold candidates for odontogenic regeneration at least as HA-TCP, when they were applied with the DPSC induced for odontogenic differentiation.

https://www.ncbi.nlm.nih.gov/pubmed/27901202

The Neurovascular Properties of Dental Stem Cells and Their Importance in Dental Tissue Engineering Ratajczak J, Bronckaers A, Dillen Y, Gervois P, Vangansewinkel T, Driesen RB, Wolfs E, Lambrichts I, Hilkens P. Stem Cells Int. 2016;2016:

Abstract

Within the field of tissue engineering, natural tissues are reconstructed by combining growth factors, stem cells, and different biomaterials to serve as a scaffold for novel tissue growth. As adequate vascularization and innervation are essential components for the viability of regenerated tissues, there is a high need for easily accessible stem cells that are capable of supporting these functions. Within the human tooth and its surrounding tissues, different stem cell populations can be distinguished, such as dental pulp stem cells, stem cells from human deciduous teeth, stem cells from the apical papilla, dental follicle stem cells, and periodontal ligament stem cells. Given their straightforward and relatively easy isolation from extracted third molars, dental stem cells (DSCs) have become an attractive source of mesenchymal-like stem cells. Over the past decade, there have been numerous studies supporting the angiogenic, neuroprotective, and neurotrophic effects of the DSC secretome. Together with their ability to differentiate into endothelial cells and neural cell types, this makes DSCs suitable candidates for dental tissue engineering and nerve injury repair.

https://www.ncbi.nlm.nih.gov/pubmed/27688777

Human dental pulp stem cells transplantation combined with treadmill training in rats after traumatic spinal cord injury Nicola FC, Rodrigues LP, Crestani T, Quintiliano K, Sanches EF, Willborn S, Aristimunha D, Boisserand L, Pranke P, Netto CA. Braz J Med Biol Res. 2016 Aug 8;49(9)

Abstract

Spinal cord injury (SCI) is a disabling condition resulting in deficits of sensory and motor functions, and has no effective treatment. Considering that protocols with stem cell transplantation and treadmill training have shown promising results, the present study evaluated the effectiveness of stem cells from human exfoliated deciduous teeth (SHEDs) transplantation combined with treadmill training in rats with experimental spinal cord injury. Fifty-four Wistar rats were spinalized using NYU impactor. The rats were randomly distributed into 5 groups: Sham (laminectomy with no SCI, n=10); SCI (laminectomy followed by SCI, n=12); SHEDs (SCI treated with SHEDs, n=11); TT (SCI treated with treadmill training, n=11); SHEDs+TT (SCI treated with SHEDs and treadmill training; n=10). Treatment with SHEDs alone or in combination with treadmill training promoted functional recovery, reaching scores of 15 and 14, respectively, in the BBB scale, being different from the SCI group, which reached 11. SHEDs treatment was able to reduce the cystic cavity area and glial scar, increase neurofilament. Treadmill training alone had no functional effectiveness or tissue effects. In a second experiment, the SHEDs transplantation reduced the TNF-α levels in the cord tissue measured 6 h after the injury. Contrary to our hypothesis, treadmill training either alone or in combination, caused no functional improvement. However, SHEDs showed to be neuroprotective, by the reduction of TNF-α levels, the cystic cavity and the glial scar associated with the improvement of motor function after SCI. These results provide evidence that grafted SHEDs might be an effective therapy to spinal cord lesions, with possible anti-inflammatory action.

https://www.ncbi.nlm.nih.gov/pubmed/27509306/

Therapeutic Potential of Dental Pulp Stem Cell Secretome for Alzheimer's Disease Treatment: An In Vitro Study. Ahmed Nel-M, Murakami M, Hirose Y, Nakashima M. Stem Cells Int. 2016;2016

Abstract

The secretome obtained from stem cell cultures contains an array of neurotrophic factors and cytokines that might have the potential to treat neurodegenerative conditions. Alzheimer's disease (AD) is one of the most common human late onset and sporadic neurodegenerative disorders. Here, we investigated the therapeutic potential of secretome derived from dental pulp stem cells (DPSCs) to reduce cytotoxicity and apoptosis caused by amyloid beta (Aβ) peptide. We determined whether DPSCs can secrete the Aβ-degrading enzyme, neprilysin (NEP), and evaluated the effects of NEP expression in vitro by quantitating Aβ-degrading activity. The results showed that DPSC secretome contains higher concentrations of VEGF, Fractalkine, RANTES, MCP-1, and GM-CSF compared to those of bone marrow and adipose stem cells. Moreover, treatment with DPSC secretome significantly decreased the cytotoxicity of Aβ peptide by increasing cell viability compared to nontreated cells. In addition, DPSC secretome stimulated the endogenous survival factor Bcl-2 and decreased the apoptotic regulator Bax. Furthermore, neprilysin enzyme was detected in DPSC secretome and succeeded in degrading Aβ 1-42 in vitro in 12 hours. In conclusion, our study demonstrates that DPSCs may serve as a promising source for secretome-based treatment of Alzheimer's disease.

https://www.ncbi.nlm.nih.gov/pubmed/27403169

Dental mesenchymal stem cells Sharpe PT. Development. 2016 Jul 1;143(13)

Abstract

Mammalian teeth harbour mesenchymal stem cells (MSCs), which contribute to tooth growth and repair. These dental MSCs possess many in vitro features of bone marrow-derived MSCs, including clonogenicity, expression of certain markers, and following stimulation, differentiation into cells that have the characteristics of osteoblasts, chondrocytes and adipocytes. Teeth and their support tissues provide not only an easily accessible source of MSCs but also a tractable model system to study their function and properties in vivo In addition, the accessibility of teeth together with their clinical relevance provides a valuable opportunity to test stem cell-based treatments for dental disorders. This Review outlines some recent discoveries in dental MSC function and behaviour and discusses how these and other advances are paving the way for the development of new biologically based dental therapies.

https://www.ncbi.nlm.nih.gov/pubmed/27381225/