Sakakura T, Fujita K, Yasui T, Sasaki S, Mabuchi Y, Iguchi M, Kohri K
Department of Urology and The 1st Department of Anatomy, Nagoya City University Medical School, Nagoya, Japan.
Urol Res. 1999 Jun;27(3):200-5. doi: 10.1007/s002400050110.
The canine renal distal tubular cell line Madin-Darby canine kidney (MDCK) forms calcium phosphate microliths during a long-term culture in vitro. We identified osteopontin (OPN) and calprotectin (CPT) from a urinary stone matrix. We recently also detected the expression of OPN and CPT in MDCK cells. The relationship between the mechanism of the stone formation and these stone matrix proteins is not yet known. Here, MDCK cells were cultured and inoculated in the subcutis of nude mice. After 4, 8 and 12 weeks, the inoculated tissues were resected, fixed and immunostained with polyclonal anti-human OPN and polyclonal anti-human CPT antibodies. Some serial specimens were stained with von Kossa's procedure. MDCK cells formed some follicular formations in the subcutis of nude mice at least at 12 weeks after transplantation. At 8 weeks after the inoculation, we detected small calcium phosphate stones with MDCK cells trapped in the follicles. The cells forming the stones also expressed both OPN and CPT. The CPT expression sites coincided with the stone formation sites. We confirmed that MDCK cells inoculated in nude mice had stone-forming potential, and we speculate that OPN and CPT play important roles in stone formation by MDCK cells.
犬肾远端肾小管细胞系马-达二氏犬肾（MDCK）在体外长期培养过程中会形成磷酸钙微晶。我们从尿结石基质中鉴定出骨桥蛋白（OPN）和钙卫蛋白（CPT）。我们最近还检测到MDCK细胞中OPN和CPT的表达。结石形成机制与这些结石基质蛋白之间的关系尚不清楚。在此，将MDCK细胞培养并接种于裸鼠皮下。4周、8周和12周后，切除接种组织，固定并用抗人OPN多克隆抗体和抗人CPT多克隆抗体进行免疫染色。一些连续标本用冯·科萨氏法染色。MDCK细胞至少在移植后12周在裸鼠皮下形成了一些滤泡样结构。接种后8周，我们检测到有MDCK细胞被困在滤泡中的小磷酸钙结石。形成结石的细胞也同时表达OPN和CPT。CPT的表达位点与结石形成位点一致。我们证实接种于裸鼠的MDCK细胞具有结石形成潜能，并且推测OPN和CPT在MDCK细胞形成结石过程中发挥重要作用。
