Background
miR-19b has been reported to be involved in nervous system disease including Parkinson's disease (PD). However its molecular basis has not been exhaustively elucidated. Materials and
Conclusion
the neuroprotective effect of miR-19b might be mediated by HAPLN4/MAPK pathway in SH-SY5Y cells.
Methods
SH-SY5Y cells were treated with 1-methyl-4-phenylpyridinium (MPP+) to construct PD model in vitro. RT-qPCR was performed to detect the expression of miR-19b and proteoglycan link protein 4 (HAPLN4) mRNA. Western blot analysis was used to measure the level of HAPLN4 and mitogen activated protein kinase (MAPK)-related protein. Cell viability and apoptosis were determined by MTT and flow cytometry. Commercial ELISA kits were applied to quantify caspase-3 activity, lactate dehydrogenase (LDH), reactive oxygen species (ROS), superoxide dismutase (SOD), tumor necrosis factor-α (TNF-α) and interleukin-1 beta (IL-1β). Dual-luciferase reporter assay was applied to assess the relationship between miR-19b and HAPLN4.
Results
miR-19b was downregulated in MPP+-induced SH-SY5Y cells. miR-19b overexpression reversed MPP+-induced suppression of cell viability and promotion of cell apoptosis in SH-SY5Y cells. Moreover, miR-19b alleviated MPP+-induced cytotoxicity of SH-SY5Y cells, embodied by the decrease of LDH release, caspase-3 activity, ROS expression, TNF-α and IL-1β secretion, as well as the increase of SOD level. HAPLN4 was identified as a direct target of miR-19b and miR-19b repressed HAPLN4 expression in a post-transcriptional manner. In addition, miR-19b-mediated anti-apoptosis effect was abated following HAPLN4 expression restoration in MPP+-induced SH-SY5Y cells. Furthermore, MAPK signaling participated in miR-19b/HAPLN4-mediated regulation in MPP+-treated SH-SY5Y cells.