The mechanism of action of FXR1P-related miR-19b-3p in SH-SY5Y

•We firstly found and confirmed that miR-19b-3p could act on FXR1.•3′ UTR and reversely be regulated by FXR1.•Both FMR1 and FXR1 are important genes for the process of FXS.•FXR1, USP32, RAB18 and Dusp6 are target genes of miR-19b-3p.•We, for the first time, demonstrated that miR-19b-3p was involved in the proliferation, apoptosis and cycle of SH-SY5Y cells.

The biological effects of microRNAs (miRNAs) in the Fragile X Syndrome (FXS) have been widely studied. Dysregulation of miRNAs plays a critical role in the progression of nervous system diseases and in cell proliferation and differentiation. Our previous study validated that miR-19b-3p was associated with FXR1 (Fragile X related gene 1), one of homologous genes of FMR1 (Fragile X mental retardation 1). The purpose of this study was to investigate the relationship of FXR1 and miR-19b-3p, and the crucial role of miR-19b-3p in FXS and to validate whether miR-19b-3p could regulate the growth of SH-SY5Y cells. We determined that miR-19b-3p could regulate the expression of not only USP32, RAB18 and Dusp6 but also FXR1, and FXR1 could in turn regulate the expression of miR-19b-3p. What's more, the overexpression of miR-19b-3p significantly inhibited the proliferation, contributed the apoptosis and slowed down the cycle of SH-SY5Y cells. Taken together, our results indicate that miR-19b-3p plays a significant role in the molecular pathology of FXS by interacting with FXR1 and influencing the growth of SH-SY5Y cells.