Analysis of the m6A modification regulators in the substantia nigra and striatum of MPTP-induced Parkinson's disease mice

Parkinson's disease (PD) is one of the most common neurodegenerative disorders of aging that impairs predominately dopaminergic neurons. N6-methyladenosine (m6A) is the most prevalent form of internal RNA modification in eukaryotes and it plays an essential role in normal brain development and neurodegenerative diseases. The m6A status is dynamically modulated by diverse types of genes called "writers", "erasers" and "readers". However, whether these m6A regulators are perturbed in PD remains poorly understood. To clarify this point, we established a PD mouse model using 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). The motor as well as learning and memory ability of mice were evaluated through and rotarod and Y maze spontaneous alternation tests. Morphological characteristics of tyrosine hydroxylase (TH)-positive cells were visualized using immunohistochemistry, while expression of alpha-synuclein (α-syn) and TH were determined by using western blot. Furthermore, the expression of the m6A regulators in the substantia nigra and striatum were evaluated by using qRT-PCR and western blot. As a result, the MPTP-induced PD mice suffered from learning and memory as well as motor defects. Additionally, there were significant TH+ neuron losses in the substantia nigra and striatum of MPTP-injected mice. In the PD mice, proteins including ALKBH5, IGF2BP2 were up-regulated in the substantia nigra, while YTHDF1 and FMR1 were down-regulated. For the striatum, FMR1 and CBLL1were up-regulated, while IGF2BP3, METTL3 and RBM15 were down-regulated. The expressions of genes at the mRNA level were partially in accordance with the protein changes. These findings indicate the m6A regulators may participate in PD pathogenesis.

MPTP; Parkinson’s disease; m6A regulators; striatum; substantia nigra.