Characterization of Mitochondrial Alterations in Aicardi-Goutières Patients Mutated in RNASEH2A and RNASEH2B Genes

• Published in: International journal of molecular sciences 2022-11, Vol.23 (22), p.14482
• Main Authors: Dragoni, Francesca, Garau, Jessica, Sproviero, Daisy, Orcesi, Simona, Varesio, Costanza, De Siervi, Silvia, Gagliardi, Stella, Cereda, Cristina, Pansarasa, Orietta
• Format: Article
• Language: English
• Subjects: Adenosine; Aicardi–Goutières syndrome; Antibodies; Autoimmune Diseases of the Nervous System - genetics; Cerebrospinal fluid; Disease; DNA, Mitochondrial - genetics; DNA, Mitochondrial - metabolism; Encephalopathy; Flow cytometry; Genes; Humans; IFN-α; Immune system; Immunofluorescence; Immunology; Lymphoblastoid cell lines; Membrane potential; Membranes; Metabolism; Mitochondria; mitochondrial disorder; Mitochondrial DNA; mitochondrial stress; Morphology; mtDNA; Mutation; Nervous System Malformations - genetics; Oligomerization; Oxidation; Oxidative stress; Pathogenesis; Patients; Phosphorylation; Physiology; Pore formation; Reactive oxygen species; Reactive Oxygen Species - metabolism; ROS; Transmission electron microscopy
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms232214482

Aicardi-Goutières syndrome (AGS) is a rare encephalopathy characterized by neurological and immunological features. Mitochondrial dysfunctions may lead to mitochondrial DNA (mtDNA) release and consequent immune system activation. We investigated the role of mitochondria and mtDNA in AGS pathogenesis by studying patients mutated in and genes. Lymphoblastoid cell lines (LCLs) from - and -mutated patients and healthy control were used. Transmission Electron Microscopy (TEM) and flow cytometry were used to assess morphological alterations, reactive oxygen species (ROS) production and mitochondrial membrane potential variations. Seahorse Analyzer was used to investigate metabolic alterations, and mtDNA oxidation and VDAC1 oligomerization were assessed by immunofluorescence. Western blot and RT-qPCR were used to quantify mtTFA protein and mtDNA release. Morphological alterations of mitochondria were observed in both mutated LCLs, and loss of physiological membrane potential was mainly identified in LCLs. ROS production and 8-oxoGuanine levels were increased in LCLs. Additionally, the VDAC1 signal was increased, suggesting a mitochondrial pore formation possibly determining mtDNA release. Indeed, higher cytoplasmic mtDNA levels were found in LCLs. Metabolic alterations confirmed mitochondrial damage in both LCLs. Data highlighted mitochondrial alterations in AGS patients' LCLs suggesting a pivotal role in AGS pathogenesis.