Accumulation of autophagic vacuoles and cardiomyopathy in LAMP-2-deficient mice.
Lysosome-associated membrane protein-2 (LAMP-2) is a highly glycosylated protein and an important constituent of the lysosomal membrane. Here we show that LAMP-2 deficiency in mice increases mortality between 20 and 40 days of age. The surviving mice are fertile and have an almost normal life span. Ultrastructurally, there is extensive accumulation of autophagic vacuoles in many tissues including liver, pancreas, spleen, kidney and skeletal and heart muscle. In hepatocytes, the autophagic degradation of long-lived proteins is severely impaired. Cardiac myocytes are ultrastructurally abnormal and heart contractility is severely reduced. These findings indicate that LAMP-2 is critical for autophagy. This theory is further substantiated by the finding that human LAMP-2 deficiency causing Danon's disease is associated with the accumulation of autophagic material in striated myocytes.
Tanaka
Y
Y
Zentrum Biochemie und Molekulare Zellbiologie, Abt. Biochemie II, Universität Göttingen, Germany.
Guhde
G
G
Suter
A
A
Eskelinen
E L
EL
Hartmann
D
D
Lüllmann-Rauch
R
R
Janssen
P M
PM
Blanz
J
J
von Figura
K
K
Saftig
P
P
D000596:Amino Acids / Q000097:blood; D000818:Animals; D015703:Antigens, CD / Q000235:genetics / Q000502:physiology*; D001343:Autophagy; D001835:Body Weight; D009202:Cardiomyopathies / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D002478:Cells, Cultured; D003433:Crosses, Genetic; D005260:Female; D018390:Gene Targeting; D005934:Glucagon / Q000097:blood; D006801:Humans; D008099:Liver / Q000473:pathology; D016464:Lysosomal Storage Diseases / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D051907:Lysosomal Membrane Proteins; D008297:Male; D008562:Membrane Glycoproteins / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D051379:Mice; D009132:Muscles / Q000473:pathology; D009200:Myocardial Contraction; D009929:Organ Size; D010179:Pancreas / Q000473:pathology; D014617:Vacuoles / Q000473:pathology
D000596:Amino Acids; D015703:Antigens, CD; D051907:Lysosomal Membrane Proteins; D008562:Membrane Glycoproteins; D005934:Glucagon