Regulation of Endoplasmic Reticulum-Mitochondria Tethering and Ca
| Autor: | Alessandro Bertoli, Tito Calì, Maria Lina Massimino, Caterina Peggion, Raphael Severino Bonadio, Stefano Cagnin, Raffaele Lopreiato, Federica Lia |
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| Rok vydání: | 2021 |
| Předmět: |
amyotrophic lateral sclerosis
QH301-705.5 TDP-43 ER–mitochondria contacts Aequorin Amyotrophic lateral sclerosis Calcium homeostasis GSK3β Neurodegenerative disorders SPLICS Mitochondrion Endoplasmic Reticulum Catalysis Article Green fluorescent protein Inorganic Chemistry Organelle Gene silencing Humans Physical and Theoretical Chemistry Nuclear protein Biology (General) Molecular Biology QD1-999 Spectroscopy Messenger RNA Glycogen Synthase Kinase 3 beta biology calcium homeostasis Chemistry Endoplasmic reticulum Organic Chemistry General Medicine Computer Science Applications Cell biology Mitochondria DNA-Binding Proteins Gene Expression Regulation neurodegenerative disorders Gene Knockdown Techniques biology.protein Calcium HeLa Cells Signal Transduction |
| Zdroj: | International Journal of Molecular Sciences Volume 22 Issue 21 International Journal of Molecular Sciences, Vol 22, Iss 11853, p 11853 (2021) |
| ISSN: | 1422-0067 |
| Popis: | Mitochondria–ER contacts (MERCs), tightly regulated by numerous tethering proteins that act as molecular and functional connections between the two organelles, are essential to maintain a variety of cellular functions. Such contacts are often compromised in the early stages of many neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS). TDP-43, a nuclear protein mainly involved in RNA metabolism, has been repeatedly associated with ALS pathogenesis and other neurodegenerative diseases. Although TDP-43 neuropathological mechanisms are still unclear, the accumulation of the protein in cytoplasmic inclusions may underlie a protein loss-of-function effect. Accordingly, we investigated the impact of siRNA-mediated TDP-43 silencing on MERCs and the related cellular parameters in HeLa cells using GFP-based probes for MERCs quantification and aequorin-based probes for local Ca2+ measurements, combined with targeted protein and mRNA profiling. Our results demonstrated that TDP-43 down-regulation decreases MERCs density, thereby remarkably reducing mitochondria Ca2+ uptake after ER Ca2+ release. Thorough mRNA and protein analyses did not highlight altered expression of proteins involved in MERCs assembly or Ca2+-mediated ER–mitochondria cross-talk, nor alterations of mitochondrial density and morphology were observed by confocal microscopy. Further mechanistic inspections, however, suggested that the observed cellular alterations are correlated to increased expression/activity of GSK3β, previously associated with MERCs disruption. |
| Databáze: | OpenAIRE |
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