Retinoic acid induces differentiation of cochlear neural progenitor cells into hair cells / O ácido retinoico induz a diferenciação das células progenitoras neurais cocleares em células ciliadas

Abstract Introduction: Inner ear progenitor cells have the potential for multi-directional differentiation. Retinoic acid is an important requirement for the development of the inner ear. Blocking the Curtyr's retinoic acid signaling pathway can significantly reduce the number of hair cells. Therefore, we believe that retinoic acid may induce the regeneration of inner ear hair cells. Objective: To investigate whether the cochlear neural progenitor cells maintain the characteristics of stem cells during recovery and subculture, whether retinoic acid can induce cochlear neural progenitor cells into hair cells in vitro, and whether retinoic acid promotes or inhibits the proliferation of cochlear neural progenitor cells during differentiation. Methods: Cochlear neural progenitor cells were cultured and induced in DMEM/F12 + RA (10−6M) and then detected the expressions of hair cell markers (Math1 and MyosinVIIa) by immunofluorescence cytochemistry and realtime-polymerase chain reaction, and the proliferation of cochlear neural progenitor cells was detected by Brdu. Results: The nestin of cochlear neural progenitor cells was positively expressed. The ratios of Math1-positive cells in the control group and experimental group were 1.5% and 63%, respectively; the ratios of MyosinVIIa-positive cells in the control group and experimental group were 0.96% and 56%, respectively (p <0.05). The ratios of Brdu+-labeled cells in retinoic acid group, group PBS, and group FBS were 20.6%, 29.9%, and 54.3%, respectively; however, the proliferation rate in the experimental group decreased. Conclusion: Retinoic acid can promote cochlear neural progenitor cells to differentiate into the hair cells.

Resumo Introdução: As células progenitoras da orelha interna têm potencial para diferenciação multidirecional. O ácido retinoico é uma condição importante para o desenvolvimento da orelha interna. O bloqueio da via de sinalização do ácido retinoico no órgão de Corti pode reduzir significativamente o número de células ciliadas. Portanto, acreditamos que o ácido retinoico pode induzir a regeneração das células ciliadas do ouvido interno. Objetivo: Investigar se as células progenitoras neurais cocleares mantêm as características das células-tronco durante a recuperação e subcultura, se o ácido retinoico pode induzir a transformação de células progenitoras neurais cocleares em células ciliadas in vitro e se o ácido retinoico promove ou inibe a proliferação das células progenitoras durante a diferenciação. Método: As células progenitoras neurais cocleares foram cultivadas e induzidas em DMEM/F12+AR (106M) e, então, foram detectadas as expressões de marcadores das células ciliadas (Math1 e Myosin?a) com o uso de citoquímica por imunofluorescência e real time -polymerase chain reaction e a proliferação de células progenitoras neurais cocleares foi detectada pelo teste Brdu. Resultados: A nestina das células progenitoras neurais cocleares foi expressa positivamente. As proporções de células positivas para Math1 no grupo controle e no grupo experimental foram 1,5% e 63%, respectivamente; as proporções de células positivas para Myosin?a no grupo controle e no grupo experimental foram de 0,96% e 56%, respectivamente (p <0,05). As proporções de células marcadas com Brdu+ no grupo ácido retinoico, grupo PBS e grupo FBS foram de 20,6%, 29,9% e 54,3%, respectivamente; no entanto, a taxa de proliferação no grupo experimental diminuiu. Conclusões: O ácido retinoico pode promover a diferenciação das células progenitoras neurais cocleares em células ciliadas.

Retinoic acid induces differentiation of cochlear neural progenitor cells into hair cells.

INTRODUCTION: Inner ear progenitor cells have the potential for multi-directional differentiation. Retinoic acid is an important requirement for the development of the inner ear. Blocking the Curtyr's retinoic acid signaling pathway can significantly reduce the number of hair cells. Therefore, we believe that retinoic acid may induce the regeneration of inner ear hair cells. OBJECTIVE: To investigate whether the cochlear neural progenitor cells maintain the characteristics of stem cells during recovery and subculture, whether retinoic acid can induce cochlear neural progenitor cells into hair cells in vitro, and whether retinoic acid promotes or inhibits the proliferation of cochlear neural progenitor cells during differentiation. METHODS: Cochlear neural progenitor cells were cultured and induced in DMEM/F12+RA (10-6M) and then detected the expressions of hair cell markers (Math1 and MyosinVIIa) by immunofluorescence cytochemistry and realtime-polymerase chain reaction, and the proliferation of cochlear neural progenitor cells was detected by Brdu. RESULTS: The nestin of cochlear neural progenitor cells was positively expressed. The ratios of Math1-positive cells in the control group and experimental group were 1.5% and 63%, respectively; the ratios of MyosinVIIa-positive cells in the control group and experimental group were 0.96% and 56%, respectively (p<0.05). The ratios of Brdu+-labeled cells in retinoic acid group, group PBS, and group FBS were 20.6%, 29.9%, and 54.3%, respectively; however, the proliferation rate in the experimental group decreased. CONCLUSION: Retinoic acid can promote cochlear neural progenitor cells to differentiate into the hair cells.