Transcriptome Analysis Reveals Altered Inflammatory Pathway in an Inducible Glial Cell Model of Myotonic Dystrophy Type 1.

Cuauhtli N Azotla-Vilchis,Oscar Hernández-Hernández,Jonathan J Magaña,Bulmaro Cisneros,Arturo Ortega,Claudia Rangel,Karla Vázquez-Santillán,J Manuel Hernández-Hernández,Daniel Sanchez-Celis,Rocío Suárez-Sánchez,Jorge Peña,Norberto Leyva-García,Vilma Maldonado,Luis E Agonizantes-Juárez

doi:10.3390/biom11020159

Abstract

Myotonic dystrophy type 1 (DM1), the most frequent inherited muscular dystrophy in adults, is caused by the CTG repeat expansion in the 3′UTR of the DMPK gene. Mutant DMPK RNA accumulates in nuclear foci altering diverse cellular functions including alternative splicing regulation. DM1 is a multisystemic condition, with debilitating central nervous system alterations. Although a defective neuroglia communication has been described as a contributor of the brain pathology in DM1, the specific cellular and molecular events potentially affected in glia cells have not been totally recognized. Thus, to study the effects of DM1 mutation on glial physiology, in this work, we have established an inducible DM1 model derived from the MIO-M1 cell line expressing 648 CUG repeats. This new model recreated the molecular hallmarks of DM1 elicited by a toxic RNA gain-of-function mechanism: accumulation of RNA foci colocalized with MBNL proteins and dysregulation of alternative splicing. By applying a microarray whole-transcriptome approach, we identified several gene changes associated with DM1 mutation in MIO-M1 cells, including the immune mediators CXCL10, CCL5, CXCL8, TNFAIP3, and TNFRSF9, as well as the microRNAs miR-222, miR-448, among others, as potential regulators. A gene ontology enrichment analyses revealed that inflammation and immune response emerged as major cellular deregulated processes in the MIO-M1 DM1 cells. Our findings indicate the involvement of an altered immune response in glia cells, opening new windows for the study of glia as potential contributor of the CNS symptoms in DM1.

Highlights

MIO-M1-CTG(648) cells after triplet repeat-primed polymerase chain reaction (TP-PCR) analysis, unlike MIO-M1-CTG(0) cells, which lacked this characteristic pattern (Figure S1B). Confirming this result, SP-PCR experiments on MIO-M1-CTG(648) cells resulted in the amplification of a DNA fragment that corresponds to 648 CTG repeats tract, while no amplified expanded fragment was obtained from MIOM1-CTG(0) cells (Figure S1C)
These results demonstrated that control and mutant
By Gene set enrichment analysis (GSEA) approach, we identified the TNF-α via NFκB signaling pathway, the INF-γ response mechanism, the E2F targets, and the inflammatory response as the most gene set enriched hallmarks in MIO-M1-CTG(648) Dox-induced cells (Figure 4)

Summary

Introduction

Myotonic Dystrophy type 1 (DM1), an inherited neuromuscular disorder, is the most common form of muscular dystrophy in adults, with a prevalence between 0.5–18.1 per Biomolecules 2021, 11, 159. The neuronal features exhibited by patients with DM1 depend on the age of onset and size of the CTG tract [6,7]. Intellectual disability is present in the congenital form of DM1; while learning difficulties, speech and language delay, reduced IQ-values accompanied with attention deficit hyperactive disorder, and autism spectrum are frequent in infantile- and juvenile-onset DM1 [8,9]. Attention deficit, excessive daytime sleepiness, and fatigue are commonly present in the adult form [7]

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Results

Conclusion