Altered expression of junctional adhesion molecule 4 in injured podocytes
- 1 February 2006
- journal article
- research article
- Published by American Physiological Society in American Journal of Physiology-Renal Physiology
- Vol. 290 (2), F335-F344
- https://doi.org/10.1152/ajprenal.00253.2005
Abstract
Recent investigations have revealed the importance of glomerular podocytes with its diaphragm as the major filtration barrier. Junctional adhesion molecule 4 (JAM4) has been identified as a protein that interacts with membrane-associated guanyl kinase inverted (MAGI)-1 and is reported to be expressed on podocytes. To elucidate the role of JAM4 on podocytes, we examined the expression of JAM4 and MAGI-1 in normal and two different proteinuric rat models: puromycin aminonucleoside (PAN) nephropathy and anti-nephrin antibody-induced (ANA) nephropathy, one model with and one without effacement of podocyte foot processes. JAM4 was detected by immunomicroscopy at the apical membrane of normal podocytes. JAM4 immunostaining was focally increased in the podocytes in PAN nephropathy but not in ANA nephropathy. In proteinuric podocytes, the expression of JAM4 was distinct from that of MAGI-1 or other slit diaphragm molecules such as nephrin and ZO-1. Close colocalization of JAM4 and ezrin was maintained in PAN nephropathy. By immunoelectron microscopy, the signals for JAM4 were detected at the free apical membrane of the podocytes with effaced foot processes. Studies with selective detergent extract revealed that the subcellular localization of JAM4 was altered in PAN nephropathy. Thus the altered expression of JAM4 appears to be associated with morphological changes in podocytes and can be a useful marker of injured podocytes. JAM4 may have a different role at the apical membrane besides the role as a junctional molecule and is likely associated with the unique structure of this epithelium.Keywords
This publication has 36 references indexed in Scilit:
- Junctional adhesion molecules (JAMs): more molecules with dual functions?Journal of Cell Science, 2004
- Podocyte cytoskeleton is connected to the integral membrane protein podocalyxin through Na + /H + -exchanger regulatory factor 2 and ezrinClinical and Experimental Nephrology, 2003
- Cloning of an Immunoglobulin Family Adhesion Molecule Selectively Expressed by Endothelial CellsJournal of Biological Chemistry, 2001
- Localization of membrane-associated guanylate kinase (MAGI)-1/BAI-associated protein (BAP) 1 at tight junctions of epithelial cellsOncogene, 1999
- Isoforms of the Lutheran/Basal Cell Adhesion Molecule Glycoprotein Are Differentially Delivered in Polarized Epithelial CellsPublished by Elsevier BV ,1999
- Cloning and Characterization of BAI-Associated Protein 1: A PDZ Domain-Containing Protein That Interacts with BAI1Biochemical and Biophysical Research Communications, 1998
- The plasma membrane-actin linking protein, ezrin, is a glomerular epithelial cell marker in glomerulogenesis, in the adult kidney and in glomerular injuryKidney International, 1998
- An Adenosine Deaminase Inhibitor Prevents Puromycin Aminonucleoside NephrotoxicityFree Radical Biology & Medicine, 1997
- Epitope-specific induction of mesangial lesions with proteinuria by a MoAb against mesangial cell surface antigenClinical and Experimental Immunology, 1992
- Identification and characterization of podocalyxin--the major sialoprotein of the renal glomerular epithelial cell.The Journal of cell biology, 1984