PMID- 23970164
OWN - NLM
STAT- MEDLINE
DCOM- 20141216
LR  - 20230815
IS  - 1554-8635 (Electronic)
IS  - 1554-8627 (Linking)
VI  - 9
IP  - 10
DP  - 2013 Oct
TI  - Modulation of intracellular calcium homeostasis blocks autophagosome formation.
PG  - 1475-90
LID - 10.4161/auto.25900 [doi]
AB  - Cellular stress responses often involve elevation of cytosolic calcium levels, 
      and this has been suggested to stimulate autophagy. Here, however, we 
      demonstrated that agents that alter intracellular calcium ion homeostasis and 
      induce ER stress-the calcium ionophore A23187 and the sarco/endoplasmic reticulum 
      Ca (2+)-ATPase inhibitor thapsigargin (TG)-potently inhibit autophagy. This 
      anti-autophagic effect occurred under both nutrient-rich and amino acid 
      starvation conditions, and was reflected by a strong reduction in autophagic 
      degradation of long-lived proteins. Furthermore, we found that the 
      calcium-modulating agents inhibited autophagosome biogenesis at a step after the 
      acquisition of WIPI1, but prior to the closure of the autophagosome. The latter 
      was evident from the virtually complete inability of A23187- or TG-treated cells 
      to sequester cytosolic lactate dehydrogenase. Moreover, we observed a decrease in 
      both the number and size of starvation-induced EGFP-LC3 puncta as well as reduced 
      numbers of mRFP-LC3 puncta in a tandem fluorescent mRFP-EGFP-LC3 cell line. The 
      anti-autophagic effect of A23187 and TG was independent of ER stress, as chemical 
      or siRNA-mediated inhibition of the unfolded protein response did not alter the 
      ability of the calcium modulators to block autophagy. Finally, and remarkably, we 
      found that the anti-autophagic activity of the calcium modulators did not require 
      sustained or bulk changes in cytosolic calcium levels. In conclusion, we propose 
      that local perturbations in intracellular calcium levels can exert inhibitory 
      effects on autophagy at the stage of autophagosome expansion and closure.
FAU - Engedal, Nikolai
AU  - Engedal N
AD  - Centre for Molecular Medicine Norway (NCMM); Nordic EMBL Partnership; University 
      of Oslo, Norway.
FAU - Torgersen, Maria L
AU  - Torgersen ML
AD  - Department of Biochemistry; Institute of Basic Medical Sciences; Faculty of 
      Medicine; University of Oslo, Norway.
FAU - Guldvik, Ingrid J
AU  - Guldvik IJ
AD  - Centre for Molecular Medicine Norway (NCMM); Nordic EMBL Partnership; University 
      of Oslo, Norway.
FAU - Barfeld, Stefan J
AU  - Barfeld SJ
AD  - Centre for Molecular Medicine Norway (NCMM); Nordic EMBL Partnership; University 
      of Oslo, Norway.
FAU - Bakula, Daniela
AU  - Bakula D
AD  - Autophagy Laboratory; Department of Molecular Biology; Interfaculty Institute for 
      Cell Biology; Faculty of Science; Eberhard Karls University; Tuebingen, Germany.
FAU - Saetre, Frank
AU  - Saetre F
AD  - Department of Cell Biology; Institute for Cancer Research; Norwegian Radium 
      Hospital; Oslo University Hospital; Nydalen, Oslo Norway.
FAU - Hagen, Linda K
AU  - Hagen LK
AD  - Department of Cell Biology; Institute for Cancer Research; Norwegian Radium 
      Hospital; Oslo University Hospital; Nydalen, Oslo Norway.
FAU - Patterson, John B
AU  - Patterson JB
AD  - MannKind Corporation; Valencia, CA USA.
FAU - Proikas-Cezanne, Tassula
AU  - Proikas-Cezanne T
AD  - Autophagy Laboratory; Department of Molecular Biology; Interfaculty Institute for 
      Cell Biology; Faculty of Science; Eberhard Karls University; Tuebingen, Germany.
FAU - Seglen, Per O
AU  - Seglen PO
AD  - Department of Cell Biology; Institute for Cancer Research; Norwegian Radium 
      Hospital; Oslo University Hospital; Nydalen, Oslo Norway.
FAU - Simonsen, Anne
AU  - Simonsen A
AD  - Department of Biochemistry; Institute of Basic Medical Sciences; Faculty of 
      Medicine; University of Oslo, Norway.
FAU - Mills, Ian G
AU  - Mills IG
AD  - Centre for Molecular Medicine Norway (NCMM); Nordic EMBL Partnership; University 
      of Oslo, Norway; Department of Cancer Prevention and Department of Urology; Oslo 
      University Hospitals; Oslo, Norway.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20130813
PL  - United States
TA  - Autophagy
JT  - Autophagy
JID - 101265188
RN  - 67526-95-8 (Thapsigargin)
RN  - SY7Q814VUP (Calcium)
SB  - IM
MH  - Autophagy/*drug effects
MH  - Calcium/*metabolism
MH  - Cell Communication/drug effects/physiology
MH  - Cell Line
MH  - Cytosol/metabolism
MH  - Endoplasmic Reticulum/*drug effects/metabolism
MH  - Homeostasis/*drug effects
MH  - Humans
MH  - Intracellular Space/metabolism
MH  - Signal Transduction/drug effects
MH  - Thapsigargin/*pharmacology
OTO - NOTNLM
OT  - A23187
OT  - ER stress
OT  - autophagosome formation
OT  - autophagy
OT  - calcium
OT  - long-lived protein degradation
OT  - sequestration
OT  - thapsigargin
EDAT- 2013/08/24 06:00
MHDA- 2014/12/17 06:00
CRDT- 2013/08/24 06:00
PHST- 2013/08/24 06:00 [entrez]
PHST- 2013/08/24 06:00 [pubmed]
PHST- 2014/12/17 06:00 [medline]
AID - 25900 [pii]
AID - 10.4161/auto.25900 [doi]
PST - ppublish
SO  - Autophagy. 2013 Oct;9(10):1475-90. doi: 10.4161/auto.25900. Epub 2013 Aug 13.