LncRNA MALAT1 Facilitates Parkinson's Disease Progression by Increasing SOCS3 Promoter Methylation.

Introduction: Long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been shown to be involved in Parkinson's disease (PD) progression, but its mechanism needs to be further explored.

Methods: Mice were injected with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to induce PD mice models, and BV2 cells were treated with lipopolysaccharides (LPS) to mimic PD cell models. MALAT1 expression and suppressor of cytokine signaling 3 (SOCS3) protein level were examined using quantitative real-time PCR and Western blot, respectively. Cell functions were tested by cell counting kit 8 assay and flow cytometry. The interaction between MALAT1 and SOCS3 was confirmed using RNA pull-down and RIP assays.

Results: MALAT1 was upregulated in MPTP-induced PD mice and LPS-induced BV2 cells. Silencing of MALAT1 increased viability, while inhibiting apoptosis and inflammation in LPS-induced BV2 cells. Besides, MALAT1 enhanced the SOCS3 promoter methylation to decrease its expression by recruiting DNMT1, DNMT3A, and DNMT3B. Furthermore, SOCS3 knockdown eliminated sh-MALAT1-mediated the inhibition effect on LPS-induced BV2 cell injury. In vivo, MALAT1 silencing ameliorated neurological impairment and neuroinflammation in MPTP-induced PD mice.

Conclusion: Our data revealed that MALAT1 worsened PD processes via inhibiting SOCS3 expression by increasing its promoter methylation.