title: Endoplasmic reticulum stress and the ER mitochondrial calcium cycle in amyotrophic lateral sclerosis.
abstract: The endoplasmic reticulum (ER) is a multifunctional organelle involved in protein synthesis, processing and folding, in intracellular transport and calcium signalling. ER stress can be triggered by depletion of ER calcium content and the accumulation of un- and mis-folded proteins, and relays stress signals to the ER mitochondria calcium cycle (ERMCC) and to the nucleus and protein translation machinery. The ensuing unfolded protein response (UPR) helps to cope with ER stress. Total protein synthesis is inhibited to keep protein load low, while the synthesis of ER chaperones, which assist protein folding, is induced. If cell integrity cannot be restored, signal cascades mediating cell death are activated. This review focuses on the role of ER stress and the UPR in the pathology of amyotrophic lateral sclerosis (ALS). The triggers for ER stress are as yet unclear, but induction of UPR sensor proteins, up-regulation of chaperones and induction of cell death proteins have been described in human post mortem ALS tissue and in mutant superoxide dismutase-1 (SOD1) expressing models of ALS. TDP-43 and VAPB seem to be involved in UPR signalling as well. Recent reports raise hope that UPR sensor proteins become effective therapeutic targets in the treatment of ALS.
authors.affiliation: Hans-Berger Department of Neurology, Friedrich-Schiller-University Jena, Erlanger Allee 101, Jena, Germany. janin.lautenschlaeger@med.uni-jena.de
authors.forename: Janin
authors.initials: J
authors.lastname: Lautenschlaeger
authors.forename: Tino
authors.initials: T
authors.lastname: Prell
authors.forename: Julian
authors.initials: J
authors.lastname: Grosskreutz
mesh_terms: D000690:Amyotrophic Lateral Sclerosis / Q000503:physiopathology*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000502:physiology* / Q000648:ultrastructure; D059865:Endoplasmic Reticulum Stress / Q000502:physiology*; D006056:Golgi Apparatus / Q000502:physiology / Q000648:ultrastructure; D006801:Humans; D008928:Mitochondria / Q000378:metabolism*; D056811:Unfolded Protein Response / Q000502:physiology*
chemical_list: D004268:DNA-Binding Proteins; D002118:Calcium