The Changes of Slit Diaphragm Molecules After Using Sirolimus.
- Author:
Jung Youn CHOI
1
;
Gi Dong HAN
;
Yong Jin KIM
;
Yong Hoon PARK
Author Information
1. Department of Pediatrics, College of Medicine, Yeungnam University, Daegu, Korea. yhpark@med.yu.ac.kr
- Publication Type:In Vitro ; Original Article
- Keywords:
Sirolimus;
Proteinuria;
Cyclosporine;
Nephrin
- MeSH:
Antibodies;
Capillaries;
Cyclosporine;
Diaphragm;
Epithelial Cells;
Female;
Foot;
Humans;
Immunohistochemistry;
Injections, Intraperitoneal;
Intracellular Signaling Peptides and Proteins;
Membrane Proteins;
Podocytes;
Proteinuria;
Rats, Wistar;
RNA, Messenger;
Sirolimus;
Transplants
- From:Journal of the Korean Society of Pediatric Nephrology
2010;14(2):143-153
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
PURPOSE: Recently, massive proteinuria has been observed in some transplant patients after switching cyclosporine A (CsA) to sirolimus. To evaluate the pathogenesis of sirolimus-associated proteinuria, we investigated the early changes in slit diaphragm molecules by various administrative conditions of sirolimus and CsA. METHODS: In vitro-Mouse podocytes were incubated with buffer (C), sirolimus (10 microg/mL) after CsA (10 microg/mL) (C-S), sirolimus only (S) and CsA and sirolimus simultaneously (C+S) for 12, 24, and 48 hours. In vivo-twenty four SPF female Wistar rats were divided into 4 groups buffer (C), sirolimus after 2 weeks of CsA (C-S), sirolimus only (S) and CsA and sirolimus simultaneously (C+S). All groups were treated by intraperitoneal injection every other day for 4 weeks (CsA: 25 mg/kg, sirolimus: 0.5 mg/kg). The changes in mRNA of slit diaphragm molecules were examined by RT-PCR. RESULTS: The mRNA of nephrin was significantly decreased in group C-S and C+S in vitro. In vivo, the mRNA of nephrin in all groups using sirolimus and the mRNA of podocin in group C-S and C+S were decreased. Microscopically, group C-S and C+S showed small vacuolization and calcification in proximal tubular epithelial cells. Immunohistochemistry using nephrin and podocin antibodies did not show remarkable decrease of staining along the glomerular capillaries. Electron-microscopically, focal fusion of foot processes was seen in group C-S and C+S. CONCLUSION: This study suggests the decrease of slit diaphragm molecules (nephrin and podocin) in podocyte may be one of the causes of sirolimus associated proteinuria, and podocyte injury by sirolimus may need a primary hit by CsA to develop the proteinuria.
