Deficiency of mannose 6-phosphate receptors and lysosomal storage: a morphometric analysis of hepatocytes of neonatal mice.
Transport of lysosomal enzymes is mediated by two mannose 6-phosphate receptors: a cation dependent (CD-MPR) and a cation independent receptor (CI-MPR). In the present study the effect of MPR-deficiency on the lysosomal system of neonatal mouse hepatocytes was studied by ultrastructural morphometric analyses. The volume density of the lysosomal system in hepatocytes of mice that lack both receptors was significantly increased in comparison with controls and with mice deficient for CI-MPR only. This higher volume density was due to a nine-fold increase of residual bodies. In CI-MPR-deficient mice the volume density of the lysosomal system was not different from controls and no increase of residual bodies was observed. It is concluded that in hepatocytes of MPR-deficient neonatal mice lysosomal storage occurs when both MPRs are lacking, whereas deficiency of CI-MPR only has no effect on the ultrastructure of the lysosomal system.
Department of Cell Biology and Histology, Academic Medical Center, University of Amsterdam, P.O. Box 22700, 1100 DE, Amsterdam, The Netherlands.
Jacques P M
JP
Schellens
Paul
P
Saftig
Kurt
K
von Figura
Vincent
V
Everts
D000375:Aging / Q000235:genetics / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D002454:Cell Differentiation / Q000235:genetics; D048429:Cell Size / Q000235:genetics; D005260:Female; D022781:Hepatocytes / Q000201:enzymology* / Q000473:pathology* / Q000648:ultrastructure; D008099:Liver / Q000201:enzymology* / Q000254:growth & development / Q000473:pathology; D016464:Lysosomal Storage Diseases / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D008247:Lysosomes / Q000201:enzymology* / Q000473:pathology* / Q000648:ultrastructure; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D008854:Microscopy, Electron; D021381:Protein Transport / Q000235:genetics; D017527:Receptor, IGF Type 2 / Q000172:deficiency* / Q000235:genetics
D017527:Receptor, IGF Type 2