Isolamento e diferenciação das células-tronco da polpa dentária canina em células progenitoras neurais / Isolation and differentiation of canine dental pulp stem cells in neural progenitor cells

O objetivo deste estudo foi verificar a capacidade de diferenciação das células-tronco da polpa dentária canina em células progenitoras neurais bem como quantificar obtenção e viabilidade celular, durante três passagens em cultura. As células foram extraídas da polpa dentária de dois cadáveres caninos, com aproximadamente dez meses de idade, que foram a óbito em decorrência de traumatismo automotivo. Após três subculturas, realizou-se avaliação da viabilidade celular por quantificação em câmara de Neubauer. A partir disso, induziu-se diferenciação neural em meio de cultura neurobasal (Gibco™), com células aderidas ao plástico ou suspensas em placas tratadas com agarose. Após sete e 14 dias em cultivo indutor, observou-se morfologia e perfil imunofenotípico utilizando citometria de fluxo e imunocitoquímica fluorescente. Aos 14 dias as células apresentaram alto grau de expressão para marcadores anti-nestina e anti-glial fibrillary acidic protein (anti-GFAP). Anteriormente, obteve-se ao 25º dia, média de 18x106 células viáveis indiferenciadas oriundas do tecido pulpar. Sugere-se que as células-tronco indiferenciadas da polpa dentária canina apresentem índices satisfatórios de diferenciação em células progenitoras neurais, aderidas ou suspensas em cultura. A polpa dentária dos dentes decíduos caninos, fornece células indiferenciadas viáveis em quantidade adequada.(AU)

The objective of this study was to verify the differentiation capacity of canine tooth pulp stem cells in neural progenitor cells as well as to quantify the attainment and viability during three culture passages. The cells were extracted from the dental pulp of two canine cadavers, with approximately ten months of age, which died due to automotive trauma. After three subcultures, cell viability evaluation was performed by Neubauer chamber quantification. Neural differentiation was induced in neurobasal culture medium (Gibco ™), with cells adhered to the plastic or suspended in agarose-treated plates. After seven and 14 days in inducer culture, morphology and immunophenotypic profile were observed using flow cytometry and fluorescent immunocytochemistry. At 14 days the cells had a high degree of expression for anti-nestin and anti-glial fibrillary acidic (anti-GFAP) markers. Previously, an average of 18x106 undifferentiated viable cells from the pulp tissue were obtained on the 25th day. It is suggested that the undifferentiated canine pulp stem cells present satisfactory differentiation indices in neural progenitor cells, adhered or suspended in culture. The dental pulp of deciduous canine teeth provides viable undifferentiated cells in adequate quantity.(AU)

Isolamento e diferenciação das células-tronco da polpa dentária canina em células progenitoras neurais / Isolation and differentiation of canine dental pulp stem cells in neural progenitor cells

O objetivo deste estudo foi verificar a capacidade de diferenciação das células-tronco da polpa dentária canina em células progenitoras neurais bem como quantificar obtenção e viabilidade celular, durante três passagens em cultura. As células foram extraídas da polpa dentária de dois cadáveres caninos, com aproximadamente dez meses de idade, que foram a óbito em decorrência de traumatismo automotivo. Após três subculturas, realizou-se avaliação da viabilidade celular por quantificação em câmara de Neubauer. A partir disso, induziu-se diferenciação neural em meio de cultura neurobasal (Gibco™), com células aderidas ao plástico ou suspensas em placas tratadas com agarose. Após sete e 14 dias em cultivo indutor, observou-se morfologia e perfil imunofenotípico utilizando citometria de fluxo e imunocitoquímica fluorescente. Aos 14 dias as células apresentaram alto grau de expressão para marcadores anti-nestina e anti-glial fibrillary acidic protein (anti-GFAP). Anteriormente, obteve-se ao 25º dia, média de 18x106 células viáveis indiferenciadas oriundas do tecido pulpar. Sugere-se que as células-tronco indiferenciadas da polpa dentária canina apresentem índices satisfatórios de diferenciação em células progenitoras neurais, aderidas ou suspensas em cultura. A polpa dentária dos dentes decíduos caninos, fornece células indiferenciadas viáveis em quantidade adequada.(AU)

The objective of this study was to verify the differentiation capacity of canine tooth pulp stem cells in neural progenitor cells as well as to quantify the attainment and viability during three culture passages. The cells were extracted from the dental pulp of two canine cadavers, with approximately ten months of age, which died due to automotive trauma. After three subcultures, cell viability evaluation was performed by Neubauer chamber quantification. Neural differentiation was induced in neurobasal culture medium (Gibco ™), with cells adhered to the plastic or suspended in agarose-treated plates. After seven and 14 days in inducer culture, morphology and immunophenotypic profile were observed using flow cytometry and fluorescent immunocytochemistry. At 14 days the cells had a high degree of expression for anti-nestin and anti-glial fibrillary acidic (anti-GFAP) markers. Previously, an average of 18x106 undifferentiated viable cells from the pulp tissue were obtained on the 25th day. It is suggested that the undifferentiated canine pulp stem cells present satisfactory differentiation indices in neural progenitor cells, adhered or suspended in culture. The dental pulp of deciduous canine teeth provides viable undifferentiated cells in adequate quantity.(AU)

Orphan nuclear receptor regulation of reproduction

Orphan nuclear receptors, those without known ligands, were discovered because of their structural similarity to the ligand-driven steroid and thyroid receptors. Since their characterization, many of the orphan receptors have been adopted, i.e., ligands, usually lipids or derived lipids, have been discovered. The orphan receptors are transcriptional regulators, functioning in the reproductive context to upregulate or suppress gene expression. By this means, the orphan receptors regulate a plethora of reproductive events. In the majority of cases, the effects are stimulatory, indeed, members of the NR2 family promote Leydig cell differentiation and testicular steroidogenesis, while those of the NR4 family regulate early gestation and placental formation. The NR5 family has two members, steroidogenic factor-1 (SF-1, NR5A1) and liver receptor homolog-1 (LRH-1, NR5A2). These receptors interact with the same DNA sequence and are believed to be constitutive transcription factors. Their effects are modulated by the repressive effects of the NR0 family of orphan receptors that comprise the short heterodimeric partner (SHP, NR0B2) and dosage-sensitive sex reversal adrenal hypoplasia congenital region on the X chromosome, gene 1 (DAX1, NROB1). SHP and DAX1 inhibit the interaction of LRH-1 and SF-1 with coactivators, thereby reducing their constitutive transcriptional effects. Overall, the orphan nuclear receptors are essential regulators of reproductive function in mammals.

Orphan nuclear receptor regulation of reproduction

Orphan nuclear receptors, those without known ligands, were discovered because of their structural similarity to the ligand-driven steroid and thyroid receptors. Since their characterization, many of the orphan receptors have been adopted, i.e., ligands, usually lipids or derived lipids, have been discovered. The orphan receptors are transcriptional regulators, functioning in the reproductive context to upregulate or suppress gene expression. By this means, the orphan receptors regulate a plethora of reproductive events. In the majority of cases, the effects are stimulatory, indeed, members of the NR2 family promote Leydig cell differentiation and testicular steroidogenesis, while those of the NR4 family regulate early gestation and placental formation. The NR5 family has two members, steroidogenic factor-1 (SF-1, NR5A1) and liver receptor homolog-1 (LRH-1, NR5A2). These receptors interact with the same DNA sequence and are believed to be constitutive transcription factors. Their effects are modulated by the repressive effects of the NR0 family of orphan receptors that comprise the short heterodimeric partner (SHP, NR0B2) and dosage-sensitive sex reversal adrenal hypoplasia congenital region on the X chromosome, gene 1 (DAX1, NROB1). SHP and DAX1 inhibit the interaction of LRH-1 and SF-1 with coactivators, thereby reducing their constitutive transcriptional effects. Overall, the orphan nuclear receptors are essential regulators of reproductive function in mammals.(AU)