Τίτλος:
Enhanced podocalyxin expression alters the structure of podocyte basal
surface
Γλώσσες Τεκμηρίου:
Αγγλικά
Περίληψη:
Glomerular basement membrane (GBM) and podocalyxin are essential for
podocyte morphology. We provide evidence of functional interconnections
between basement membrane components (collagen IV and laminin), the
expression of podocalyxin and the morphology of human glomerular
epithelial cells (podocytes). We demonstrated that GBM and laminin, but
not collagen IV, up-regulated the expression of podocalyxin. Scanning
electron microscopy revealed that laminin induced a modified morphology
of podocytes with process formation, which was more extensive in the
presence of GBM. Under high magnification, podocytes appeared ruffled.
Using transmission electron microscopy we observed that raised areas
occurred in the basal cell surface. Furthermore, the presence of
anti-podocalyxin antibody increased the extent of adhesion and spreading
of podocytes to both collagen IV and laminin, thus podocalyxin
apparently inhibits cell-matrix interactions. We also performed adhesion
and spreading assays on podocytes grown under increased glucose
concentration (25 mM). Under these conditions, the expression of
podocalyxin was almost totally suppressed. The cells adhered and spread
to basement membrane components but there was no increase in the extent
of adhesion and spreading in the presence of anti-podocalyxin antibody,
or ruffling of the cell edges. Additionally, in podocytes expressing
podocalyxin, the presence of antipodocalyxin antibody partially reversed
the inhibition of adhesion to collagen IV provoked by anti-beta1
integrin antibody, thus podocalyxin should compete with beta1-related
cell adhesion. We suggest that the observed podocalyxin-mediated
inhibition of binding to the matrix could be in part responsible for the
specialized conformation of the basal surface of podocytes.
Συγγραφείς:
Economou, CG
Kitsiou, PV
Tzinia, AK
Panagopoulou, E and
Marinos, E
Kershaw, DB
Kerjaschki, D
Tsilibary, EC
Περιοδικό:
Journal of Cell Science
Εκδότης:
Company of Biologists Ltd
Λέξεις-κλειδιά:
podocalyxin; human glomerular epithelial cells; collagen IV; laminin;
glomerular basement membrane; integrins
