The Myoblast C2C12 Transfected with Mutant Valosin-Containing Protein Exhibits Delayed Stress Granule Resolution on Oxidative Stress.
Valosin-containing protein (VCP) mutations cause inclusion body myopathy with Paget disease and frontotemporal dementia. However, the mechanisms by which mutant VCP triggers degeneration remain unknown. Here, we investigated the role of VCP in cellular stress and found that the oxidative stressor arsenite and heat shock-activated stress responses evident by T-intracellular antigen-1-positive granules in C2C12 myoblasts. Granules also contained phosphorylated transactive response DNA-binding protein 43, ubiquitin, microtubule-associated protein 1A/1B light chains 3, and lysosome-associated membrane protein 2. Mutant VCP produced more T-intracellular antigen-1-positive granules than wild-type in the postarsenite exposure period. Similar results were observed for other granule components, indicating that mutant VCP delayed clearance of stress granules. Furthermore, stress granule resolution was impaired on differentiated C2C12 cells expressing mutant VCP. To address whether mutant VCP triggers dysregulation of the stress granule pathway in vivo, we analyzed skeletal muscle of aged VCPR155H-knockin mice. We found significant increments in oxidated proteins but observed the stress granule markers RasGAP SH3-binding protein and phosphorylated eukaryotic translation initiation factor 2α unchanged. The mixed results indicate that mutant VCP together with aging lead to higher oxidative stress in skeletal muscle but were insufficient to disrupt the stress granule pathway. Our findings support that deficiencies in recovery from stressors may result in attenuated tolerance to stress that could trigger muscle degeneration.
Molecular and Cell Biology, School of Natural Sciences, University of California, Merced, California.
Carlos J
CJ
Rodriguez-Ortiz
Molecular and Cell Biology, School of Natural Sciences, University of California, Merced, California.
Julio C
JC
Flores
Molecular and Cell Biology, School of Natural Sciences, University of California, Merced, California.
Joanna A
JA
Valenzuela
Molecular and Cell Biology, School of Natural Sciences, University of California, Merced, California.
Gema J
GJ
Rodriguez
Molecular and Cell Biology, School of Natural Sciences, University of California, Merced, California.
Joannee
J
Zumkehr
Molecular and Cell Biology, School of Natural Sciences, University of California, Merced, California.
Diana N
DN
Tran
Department of Pediatrics, Division of Genetics and Genomics Medicine, University of California Irvine, Irvine, California.
Virginia E
VE
Kimonis
Molecular and Cell Biology, School of Natural Sciences, University of California, Merced, California. Electronic address: mkitazawa@ucmerced.edu.
Masashi
M
Kitazawa
D000251:Adenosine Triphosphatases / Q000235:genetics*; D000818:Animals; D018797:Cell Cycle Proteins / Q000235:genetics*; D002460:Cell Line; D004195:Disease Models, Animal; D005455:Fluorescent Antibody Technique; D057180:Frontotemporal Dementia / Q000235:genetics / Q000473:pathology*; D006801:Humans; D015151:Immunoblotting; D007150:Immunohistochemistry; D051379:Mice; D049288:Muscular Dystrophies, Limb-Girdle / Q000235:genetics / Q000473:pathology*; D032446:Myoblasts / Q000378:metabolism / Q000473:pathology*; D018979:Myositis, Inclusion Body / Q000235:genetics / Q000473:pathology*; D010001:Osteitis Deformans / Q000235:genetics / Q000473:pathology*; D018384:Oxidative Stress / Q000502:physiology*; D014162:Transfection; D000074405:Valosin Containing Protein
D018797:Cell Cycle Proteins; D000251:Adenosine Triphosphatases; C000614178:VCP protein, human; D000074405:Valosin Containing Protein; C000614179:Vcp protein, mouse