[Influence of hyaluronan and CD44 expression in renal tubular epithelial cells on the adherence of calcium oxalate crystal].
OBJECTIVE
To study the expression of hyaluronan (HA) and CD44, a transmembrane glucoprotein and cell surface receptor of HA, in impaired renal tubular epithelial cells and relation thereof with the retention of calcium oxalate (CaOx) crystals in the renal tubule.


METHODS
Forty-eight SD rats were randomly divided into four equal groups, ethylene glycol (EG) 1-day group, treated with drinking water containing 0.75% EG for 1 day, EG 5-day group, treated with drinking water containing 0.75% EG for 5 days, general drinking water 1-day group, treated with tap water for 1 day, and general water 5-day group, treated with tap water for 5 days. The rats were killed 1 day or 5 days later respectively with their kidneys taken out. Immunohistochemistry was used to detect the expression of HA and CD44 in the renal tissues. Polarized light microscopy was used to detect the CaOx crystals in the renal tubules.


RESULTS
The expression rates of HA and CD44, and proportion of crystal retention of the tap water 1-day group were 25.0%, 25.0%, and 16.7% respectively, all not significantly different from those of the EG 1-day group (8.3%, 16.7%, and 25.0% respectively, all P > 0.05). The expression rates of HA and CD44, and proportion of crystal retention of the tap water 5-day group were 33.3%, 25.0%, and 16.7% respectively, all significantly lower than those of the EG 5-day group (83.3%, 75.0%, and 66.7% respectively, all P < 0.05). Microscopy showed that the CaOx crystals adhered only to the injured tubular epithelial cells expressing HA and CD44 at their luminal membrane.


CONCLUSIONS
The expression of HA and CD44 by injured tubular cells seems to play a role in the retention of CaOx crystals in the kidney.
Yu
Xiao
X
Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
Zhu
Xuan
X
Wang
Shao-Gang
SG
Chen
Zhi-Qiang
ZQ
Yang
Wei-Min
WM
Ye
Zhang-Qun
ZQ
D000818:Animals; D002129:Calcium Oxalate / Q000737:chemistry / Q000378:metabolism*; D003460:Crystallization; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D019855:Ethylene Glycol / Q000008:administration & dosage / Q000494:pharmacology; D018960:Hyaluronan Receptors / Q000096:biosynthesis*; D006820:Hyaluronic Acid / Q000096:biosynthesis*; D007150:Immunohistochemistry; D007684:Kidney Tubules / Q000166:cytology; D008297:Male; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley
D018960:Hyaluronan Receptors; D002129:Calcium Oxalate; D006820:Hyaluronic Acid; D019855:Ethylene Glycol