Heparan sulfate (HS)/heparan sulfate proteoglycan (HSPG) and bikunin are up-regulated during calcium oxalate nephrolithiasis in rat kidney.
We reported that expression of both HSPG and of bikunin are increased in calcium oxalate (CaOx) nephrolithic rat kidneys (lida et al., J. Am. Soc. Nephrol. 1999, Urol. Res. 1997). However, these findings were obtained from separate experiments. The present study evaluates whether levels of HSPG and bikunin expression differ in the rat kidney during calcium oxalate nephrolithiasis. Twenty-four male Wistar rats weighing 200-250 g were assigned to one of four groups (n = 6 each group) and administered with 0.5% ethylene glycol daily and 0.5 microgram of 1 alpha-OH-D3 every other day to induce CaOx nephrolithiasis. Animals were sacrificed 1 or 2 weeks later and both kidneys were excised. The cortex was separated from the medulla and papillary tips in the right kidney, then stored in liquid nitrogen for quantitative competitive-reverse transcription-polymerase chain reaction (QC-RT-PCR). The left kidney was fixed in 10% buffered formalin for histochemical studies. We assessed the variable gene expression of both HSPG and bikunin by QC-RT-PCR. Immunohistochemical analyses of left kidney tissue samples determined the localization of HSPG and bikunin. Normal rats serving as controls (n = 6 each) were also sacrificed and processed in the same manner as the experimental groups. QC-RT-PCR confirmed that HSPG and bikunin mRNA expression is significantly increased in nephrolithic kidneys (p < 0.05; Mann-Whitney test), and that medulla and papillary tips tended to express more mRNA of both. Immunohistochemical studies revealed that the production of HS and bikunin was increased in both the distal and proximal tubules of nephrolithic kidneys. These findings suggest that the increased expression of both HSPG and bikunin play an important role during calcium oxalate stone formation. In addition, this phenomenon might be associated with the progression of urothelial damage.
Eguchi
Yoshiro
Y
Department of Urology, Kurume University School of Medicine, 67 Asahi-machi, Kurume 830-0011, Japan.
Inoue
Michiro
M
Iida
Shizuka
S
Matsuoka
Kei
K
Noda
Shinshi
S
D000818:Animals; D002129:Calcium Oxalate / Q000378:metabolism*; D019812:Heparan Sulfate Proteoglycans / Q000096:biosynthesis* / Q000235:genetics; D006497:Heparan Sulfate / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics; D007150:Immunohistochemistry; D007668:Kidney / Q000378:metabolism*; D007669:Kidney Calculi / Q000378:metabolism*; D008297:Male; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014360:Trypsin Inhibitor, Kunitz Soybean; D015854:Up-Regulation
D002129:Calcium Oxalate; D019812:Heparan Sulfate Proteoglycans; D006497:Heparan Sulfate; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D014360:Trypsin Inhibitor, Kunitz Soybean; C109148:SPINT2 protein, human