Jazi, Ali Yousefian Kim, Su-Hyun Chu, Jiyeon Choi, Seung-Hye Nguyen, Phuong Thi Thanh Park, Uiyeol Kim, Min-gyeong Hwang, Hongik Lee, Kyung Eun Kim, Yeyun Hyeon, Seung Jae Rhim, Hyewhon Ryu, Hannah L Lim, Grewo Stein, Thor D Lim, Kayeong Ryu, Hoon Lee, Junghee 2025-02-13T03:00:07Z 2025-02-13T03:00:07Z 2025-02-11 2025-02 1750-1326 https://pubs.kist.re.kr/handle/201004/151742 Background Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder characterized by the loss of both upper and lower motor neurons, leading to progressive paralysis. Both genetic alterations and epigenetic modifications contribute to neuronal dysfunction in the pathogenesis of ALS. However, the mechanism behind genetic mutations in the non-coding region of genes that affect epigenetic modifications remains unclear. Methods Convolutional neural network was used to identify an ALS-associated SNP located in the intronic region of MEF2C (rs304152), residing in a putative enhancer element. To examine the alteration of MEF2C transcription by the SNP, we generated HEK293T cells carrying the major or minor allele by CRISPR-Cas9. To verify the role of MEF2C-knockdown (MEF2C-KD) in mice, we developed AAV expressing shRNA for MEF2C based on AAV-U6 promoter vector. Neuropathological alterations of MEF2C-KD mice with mitochondrial dysfunction and motor neuronal damage were observed by confocal microscopy and transmission electron microscope (TEM). Behavioral changes of mice were examined through longitudinal study by tail suspension, inverted grid test and automated gait analysis. Results Here, we show that enhancer mutation of MEF2C reduces own gene expression and consequently impairs mitochondrial function in motor neurons. MEF2C localizes and binds to the mitochondria DNA, and directly modulates mitochondria-encoded gene expression. CRISPR/Cas-9-induced mutation of the MEF2C enhancer decreases expression of mitochondria-encoded genes. Moreover, MEF2C mutant cells show reduction of mitochondrial membrane potential, ATP level but elevation of oxidative stress. MEF2C deficiency in the upper and lower motor neurons of mice impairs mitochondria-encoded genes, and leads to mitochondrial metabolic disruption and progressive motor behavioral deficits. Conclusions Together, MEF2C dysregulation by the enhancer mutation leads to mitochondrial dysfunction and oxidative stress, which are prevalent features in motor neuronal damage and ALS pathogenesis. This genetic and epigenetic crosstalk mechanism provides insights for advancing our understanding of motor neuron disease and developing effective treatments. English BioMed Central Loss of MEF2C function by enhancer mutation leads to neuronal mitochondria dysfunction and motor deficits in mice Article 10.1186/s13024-024-00792-y 1 Molecular Neurodegeneration, v.20, no.1 Molecular Neurodegeneration 20 1 N scie scopus 001415583700001 Neurosciences Neurosciences & Neurology Article AMYOTROPHIC-LATERAL-SCLEROSIS TRANSCRIPTION FACTOR ANALYSES IDENTIFY GENE-EXPRESSION ALS DISEASE HYPEREXCITABILITY HYPERMETHYLATION SCHIZOPHRENIA ARCHITECTURE MEF2C Single nucleotide polymorphism (SNP) Mitochondria Motor neuron Epigenetics