Neural Regenerative Potential of Stem Cells Derived from the Tooth Apical Papilla.

The regenerative effects of stem cells derived from dental tissues have been previously investigated. This study assessed the potential of human tooth stem cells from apical papilla (SCAP) on nerve regeneration. The SCAP collected from nine individuals were characterized and polarized by exposure to interferon-γ (IFN-γ). IFN-γ increased kynurenine and interleukin-6 (IL-6) production by SCAP, without affecting the cell viability. IFN-γ-primed SCAP exhibited a decrease of brain-derived neurotrophic factor (BDNF) mRNA levels, followed by an upregulation of glial cell-derived neurotrophic factor mRNA. Ex vivo, the co-culture of SCAP with neurons isolated from the rat dorsal root ganglion induced neurite outgrowth, accompanied by increased BDNF secretion, irrespective of IFN-γ priming. In vivo, the local application of SCAP reduced the mechanical and thermal hypersensitivity in Wistar rats that had been submitted to sciatic chronic constriction injury. The SCAP also reduced the pain scores, according to the evaluation of the Grimace scale, partially restoring the myelin damage and BDNF immunopositivity secondary to nerve lesion. Altogether, our results provide novel evidence about the regenerative effects of human SCAP, indicating their potential to handle nerve injury-related complications.

Nociceptin/orphanin FQ receptor modulates painful and fatigue symptoms in a mouse model of fibromyalgia.

Generalized pain and fatigue are both hallmarks of fibromyalgia, a syndrome with an indefinite etiology. The treatment options for fibromyalgia are currently limited, probably because of its intricate pathophysiology. Thus, further basic and clinical research on this condition is currently needed. This study investigated the effects of nociceptin/orphanin FQ (N/OFQ) receptor (NOPr) ligands and the modulation of the NOP system in the preclinical mouse model of reserpine-induced fibromyalgia. The effects of administration of the natural agonist N/OFQ and the selective NOPr antagonists (UFP-101 and SB-612111) were evaluated in fibromyalgia-related symptoms in reserpine-treated mice. The expression of prepronociceptin/orphanin FQ and NOPr was assessed in central and peripheral sites at different time points after reserpine administration. Nociceptin/orphanin FQ displayed dual effects in the behavioral changes in the reserpine-elicited fibromyalgia model. The peptide NOPr antagonist UFP-101 produced analgesic and antifatigue effects, by preventing alterations in brain activity and skeletal muscle metabolism, secondary to fibromyalgia induction. The nonpeptide NOPr antagonist SB-612111 mirrored the favorable effects of UFP-101 in painful and fatigue alterations induced by reserpine. A time-related up- or downregulation of prepronociceptin/orphanin FQ and NOPr was observed in supraspinal, spinal, and peripheral sites of reserpine-treated mice. Our data shed new lights on the mechanisms underlying the fibromyalgia pathogenesis, supporting a role for N/OFQ-NOP receptor system in this syndrome.

In Vivo Immunogenic Response to Allogeneic Mesenchymal Stem Cells and the Role of Preactivated Mesenchymal Stem Cells Cotransplanted with Allogeneic Islets.

Mesenchymal stem cells (MSCs) are multipotent cells capable of differentiating into cells from the mesenchymal lineage. The hypoimmunogenic characteristic of MSCs has encouraged studies using allogeneic MSCs for the treatment of autoimmune diseases and inflammatory conditions. Promising preclinical results and the safety of allogeneic MSC transplantation have created the possibility of "off-the-shelf" clinical application of allogeneic cells. This study has aimed to evaluate the survival of untreated and IFN-γ- and TNF-α-treated (preactivated) allogeneic MSCs transplanted under the kidney capsule of immunocompetent mice together with the role of preactivated MSCs after cotransplantation with allogeneic islets. The preactivation of MSCs upregulated the gene expression of anti-inflammatory molecules and also enhanced their immunomodulatory capacity in vitro. In vivo, allogeneic MSCs provoked an immunogenic response, with the infiltration of inflammatory cells at the transplant site and full graft rejection in both the untreated and preactivated groups. Allogeneic islets cotransplanted with preactivated MSCs prolonged graft survival for about 6 days, compared with islet alone. The present results corroborate the hypothesis that allogeneic MSCs are not immune-privileged and that after playing their therapeutic role they are rejected. Strategies that reduce allogeneic MSC immunogenicity can potentially prolong their in vivo persistence and improve the therapeutic effects.

Pre-culturing islets with mesenchymal stromal cells using a direct contact configuration is beneficial for transplantation outcome in diabetic mice.

BACKGROUND AIMS: We recently showed that co-transplantation of mesenchymal stromal cells (MSCs) improves islet function and revascularization in vivo. Pre-transplant islet culture is associated with the loss of islet cells. MSCs may enhance islet cell survival or function by direct cell contact mechanisms and soluble mediators. We investigated the capacity of MSCs to improve islet cell survival or ß-cell function in vitro using direct and indirect contact islet-MSC configurations. We also investigated whether pre-culturing islets with MSCs improves islet transplantation outcome. METHODS: The effect of pre-culturing islets with MSCs on islet function in vitro was investigated by measuring glucose-stimulated insulin secretion. The endothelial cell density of fresh islets and islets cultured with or without MSCs was determined by immunohistochemistry. The efficacy of transplanted islets was tested in vivo using a syngeneic streptozotocin-diabetic minimal islet mass model. Graft function was investigated by monitoring blood glucose concentrations. RESULTS: Indirect islet-MSC co-culture configurations did not improve islet function in vitro. Pre-culturing islets using a direct contact MSC monolayer configuration improved glucose-stimulated insulin secretion in vitro, which correlated with superior islet graft function in vivo. MSC pre-culture had no effect on islet endothelial cell number in vitro or in vivo. CONCLUSIONS: Pre-culturing islets with MSCs using a direct contact configuration maintains functional ß-cell mass in vitro and the capacity of cultured islets to reverse hyperglycemia in diabetic mice.

Methodology, biology and clinical applications of human mesenchymal stem cells.

Stem cells are known by their capacity of self-renewal and differentiation into at least one specialized cell type. Mesenchymal stem cells (MSCs) were isolated initially from bone marrow but are now known to exist in any vascularized organ or tissue in adults. MSCs have a great therapeutic potential, due to their ability to migrate to sites of tissue injury and secrete trophic factors that hasten endogenous repair. They have also been shown to present immunosuppressive properties that may be used in the treatment of autoimmune or graft-versus-host diseases. Clinical trials employing MSCs show that the therapy is safe, but the efficiency needs to be in tested in phase III and IV studies. We describe here protocols for the isolation of human MSCs from human bone marrow and adipose tissue. The safe use of these cells demand a thorough in vitro characterization, as described in protocols of immunophenotyping by flow cytometry and analysis of their capacity to differentiate into adipogenic, osteogenic, and chondrogenic lineages.

Association of mesenchymal stem cells with platelet rich plasma on the repair of critical calvarial defects in mice.

PURPOSE: To evaluate the effects of mesenchymal stem cells (MSC) from eight mice C57BL/6 gfp(+) bone marrows expanded in cultures associated with platelets rich plasma (PRP) deriving from another eight mice, in the repair of critical defects in calvarial bone produced in twenty-four adult isogenic mice C57BL/6. METHODS: The animals were submitted to a cranial defect of 6.0mm in diameter and divided into two equal experimental groups. Control group did not receive treatment and the treated group received a MSC pellet containing 1.0 x 10(7) cells/mL associated with 50.0 µL of plasma gel containing 1.0 x 10(9) autologous platelets within the defect. RESULTS: In the treated group was observed process of angiogenesis and bone repair better than control group. CONCLUSION: Mesenchymal stem cells derived from bone marrow of C57BL/6 gfp(+) mice associated with PRP gel applied in bone critical defects produced in calvarial contributes positively to the process of bone repair.

Association of mesenchymal stem cells with platelet rich plasma on the repair of critical calvarial defects in mice / Associação de células-tronco mesenquimais com plasma rico em plaquetas na reparação de defeitos críticos em calvária de camundongos

PURPOSE: To evaluate the effects of mesenchymal stem cells (MSC) from eight mice C57BL/6 gfp+ bone marrows expanded in cultures associated with platelets rich plasma (PRP) deriving from another eight mice, in the repair of critical defects in calvarial bone produced in twenty-four adult isogenic mice C57BL/6. METHODS: The animals were submitted to a cranial defect of 6.0mm in diameter and divided into two equal experimental groups. Control group did not receive treatment and the treated group received a MSC pellet containing 1.0 x 10(7) cells/mL associated with 50.0µL of plasma gel containing 1.0 x 10(9) autologous platelets within the defect. RESULTS: In the treated group was observed process of angiogenesis and bone repair better than control group. CONCLUSION: Mesenchymal stem cells derived from bone marrow of C57BL/6 gfp+ mice associated with PRP gel applied in bone critical defects produced in calvarial contributes positively to the process of bone repair.

OBJETIVO: Avaliar os efeitos da associação das células-tronco mesenquimais (MSC) oriundas da medula óssea de oito camundongos jovens C57BL/6 gfp+ e expandidas em culturas, com Plasma Rico em Plaquetas (PRP) provenientes de outros oito camundongos, na reparação de defeitos críticos confeccionados em calvária de 24 camundongos adultos C57BL/6. MÉTODOS: Os animais foram submetidos a um defeito craniano de 6,0mm de diâmetro e separados em dois grupos experimentais iguais. O grupo controle não recebeu tratamento e no grupo tratado foi administrado, no interior do defeito, pellet de MSC contendo 1,0 x 10(7) células/mL associado com 50,0µL de plasma em gel autólogo contendo 1,0 x 10(9) plaquetas. RESULTADOS: No grupo tratado verificou-se processo de angiogênese e reparação óssea superior ao grupo controle. CONCLUSÃO: A associação das células-tronco mesenquimais (MSC) derivadas da medula óssea de camundongos C57BL/6 gfp+ com gel de PRP aplicadas em defeitos ósseos críticos confeccionadas em calvária de camundongos C57BL/6 jovens, contribuiu positivamente para o processo de reparação óssea.

Biology and applications of mesenchymal stem cells.

Undifferentiated adult stem cells are responsible for cell replacement in adult organisms. Initially isolated from the bone marrow, they are now known to be distributed throughout the organism as a whole, with a perivascular location. They are defined by properties which include proliferation as adherent cells, a defined immunophenotype, and the capacity to differentiate in vitro into osteoblasts, adipocytes and chondroblasts. Mesenchymal stem cells (MSCs) are considered as one of the most promising cell types for therapeutic applications. Mechanisms responsible for this therapeutic role are not well understood, and may involve diferentiation or, as most evidences point out, paracrine activity. The ability to modulate the immune system opens a wide range of applications, mainly for autoimmune diseases and graft-versus-host disease. Preclinical and clinical studies show promising results, but controversial results are still reported, indicating the need for further basic and preclinical investigation on their therapeutic potential. This review will focus on recent advances in understanding MSC biology and applications in cell therapy.

The karyotype of Franciscana dolphin (Pontoporia blainvillei).

Despite the recent increase in studies on franciscana dolphin (Pontoporia blainvillei) molecular biology, there has been no published karyotype information, as opportunities for sampling live individuals are very rare. In the present study, the diploid number of the species was established from corneal cell cultures of 2 newborn male franciscanas live stranded (2n = 44). From the comparison of the chromosomal number to the cetacean karyotype phylogeny, we suggest that the most parsimonious hypothesis is that the ancestral character state in the group is the diploid number of 42, with an extra chromosome pair appearing independently twice during cetacean evolution, once in the suborder Odontoceti and once in the suborder Mysticeti. This information on chromosomal number may be useful to future genetic mapping projects of the species.

Mesenchymal stem cells reside in virtually all post-natal organs and tissues.

Mesenchymal stem cells (MSCs) are multipotent cells which can give rise to mesenchymal and non-mesenchymal tissues in vitro and in vivo. Whereas in vitro properties such as (trans)differentiation capabilities are well known, there is little information regarding natural distribution and biology in the living organism. To investigate the subject further, we generated long-term cultures of cells with mesenchymal stem cell characteristics from different organs and tissues from adult mice. These populations have morphology, immunophenotype and growth properties similar to bone marrow-derived MSCs. The differentiation potential was related to the tissue of origin. The results indicate that (1) cells with mesenchymal stem characteristics can be derived and propagated in vitro from different organs and tissues (brain, spleen, liver, kidney, lung, bone marrow, muscle, thymus, pancreas); (2) MSC long-term cultures can be generated from large blood vessels such as the aorta artery and the vena cava, as well as from small vessels such as those from kidney glomeruli; (3) MSCs are not detected in peripheral blood. Taken together, these results suggest that the distribution of MSCs throughout the post-natal organism is related to their existence in a perivascular niche. These findings have implications for understanding MSC biology, and for clinical and pharmacological purposes.