Vacuolar degeneration of skeletal muscle in transgenic mice overexpressing ORP150.
ORP150 is a hypoxic stress-induced protein located in the endoplasmic reticulum. Transgenic mice overexpressing ORP150 (ORP-Tg) exhibit vacuolar degeneration in the heart. To determine whether vacuolization is present in skeletal muscle, we pathologically examined ORP-Tg mice. After 60 days of age, severe vacuolization was found in the soleus muscles of the hind legs of the ORP-Tg mice. Immunohistochemical staining of ORP150 revealed co-localization of ORP150 and vacuolization in the affected cells. Electron microscopy revealed a marked increase in the number of rough-surfaced endoplasmic reticula (rER) and distention of the cisterna. These findings suggest that overexpression of ORP150 causes accumulation of ORP150 in the rER, resulting in vacuolar degeneration in the skeletal muscle of ORP-Tg mice.
Kobayashi
Tomohiro
T
HSP Research Institute, Kyoto Research Park, Kyoto, Japan.
Takita
Yuko
Y
Suzuki
Atsuko
A
Katsu
Yoshinao
Y
Iguchi
Taisen
T
Ohta
Yasuhiko
Y
D000818:Animals; D005786:Gene Expression Regulation; D018840:HSP70 Heat-Shock Proteins; D007150:Immunohistochemistry; D051379:Mice; D008822:Mice, Transgenic; D032342:Muscle Cells / Q000473:pathology; D018482:Muscle, Skeletal / Q000166:cytology* / Q000473:pathology*; D009135:Muscular Diseases / Q000235:genetics* / Q000473:pathology; D011506:Proteins / Q000235:genetics* / Q000378:metabolism*; D014617:Vacuoles / Q000473:pathology*
D018840:HSP70 Heat-Shock Proteins; D011506:Proteins; C050087:oxygen-regulated proteins