Suntornsaratoon Panan, Wongdee Kannikar, Thammayon Nithipak, Teerapornpuntakit Jarinthorn, Panupinthu Nattapon, Tiyasatkulkovit Wacharaporn, Lapmanee Sarawut, Chanpaisaeng Krittikan, Chantip Surachai, Charoenphandhu Narattaphol
Department of Physiology, Faculty of Science, Mahidol University, Rama VI Road, Bangkok, 10400, Thailand.
Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University, Bangkok, Thailand.
Sci Rep. 2025 Jul 1;15(1):22103. doi: 10.1038/s41598-025-06485-w.
Abnormal fluid accumulation in the renal pelvis and calyces, with enlargement of the pelvicalyceal system, leads to a devastating disease known as hydronephrosis, which subsequently induces progressive renal impairment and mineral imbalance. Since the renal tubular cells play a role in the conversion of 25-hydroxyvitamin D to 1,25-dihydroxyvitamin D [1,25(OH)D], an important calciotropic hormone, we hypothesized that the ICR/Mlac-hydro mice with bilateral non-obstructive hydronephrosis and hypoparathyroidism plausibly manifested derangements of calcium and bone metabolism. The results showed that Mlac-hydro mice had reductions in the levels of intact parathyroid hormone, 1,25(OH)D and fibroblast growth factor-23, along with downregulated TRPV6 expression in the duodenum and ~ 50% reduction in calcium flux as determined by Ca radioactive tracer. Aberrant duodenal electrical properties, i.e., decreased potential difference and increased transepithelial resistance, were also observed, indicating reduced intestinal ion permeability. Both male and female Mlac-hydro mice had shorter femoral lengths and lower volumetric bone mineral density than wild-type mice. Ultra-high resolution micro-computed tomography further revealed defects in the trabecular bone microstructure, consistent with several abnormalities of bone histomorphometric parameters, e.g., reductions in osteoblast surface, active erosion surface, mineral apposition rate and bone formation rate. Bone mechanical properties, i.e., maximum load, yield load, and stiffness, were also impaired in both male and female Mlac-hydro mice, as evaluated by the three-point bending test. In conclusion, Mlac-hydro mice with hydronephrosis and hypoparathyroidism exhibited several features of calcium dysregulation and bone defects, e.g., impaired intestinal calcium absorption, poor bone mechanical properties, and low bone turnover, the latter of which suggested an association between adynamic bone disease and hydronephrosis. Our data, therefore, provide relevant information essential for the future development of drugs or treatments for hydronephrotic patients.
肾盂和肾盏中异常的液体蓄积,以及肾盂肾盏系统的扩大,会导致一种毁灭性疾病——肾积水,进而引发进行性肾功能损害和矿物质失衡。由于肾小管细胞在将25-羟基维生素D转化为1,25-二羟基维生素D[1,25(OH)D](一种重要的钙调节激素)过程中发挥作用,我们推测患有双侧非梗阻性肾积水和甲状旁腺功能减退的ICR/Mlac-hydro小鼠可能表现出钙和骨代谢紊乱。结果显示,Mlac-hydro小鼠的完整甲状旁腺激素、1,25(OH)D和成纤维细胞生长因子-23水平降低,十二指肠中TRPV6表达下调,并且通过钙放射性示踪剂测定的钙通量降低约50%。还观察到十二指肠电特性异常,即电位差降低和跨上皮电阻增加,表明肠道离子通透性降低。雄性和雌性Mlac-hydro小鼠的股骨长度均短于野生型小鼠,骨体积密度也低于野生型小鼠。超高分辨率微计算机断层扫描进一步揭示了小梁骨微结构的缺陷,这与骨组织形态计量学参数的几个异常情况一致,例如成骨细胞表面、活跃侵蚀表面、矿物质沉积率和骨形成率降低。通过三点弯曲试验评估发现,雄性和雌性Mlac-hydro小鼠的骨力学性能,即最大载荷、屈服载荷和刚度也受损。总之,患有肾积水和甲状旁腺功能减退的Mlac-hydro小鼠表现出钙调节和骨缺陷的几个特征,例如肠道钙吸收受损、骨力学性能差和骨转换率低,后者表明骨无动力性疾病与肾积水之间存在关联。因此,我们的数据为未来开发肾积水患者的药物或治疗方法提供了重要的相关信息。