In the absence of overt urothelial damage, chondroitinase ABC digestion of the GAG layer increases bladder permeability in ovariectomized female rats
In the absence of overt urothelial damage, chondroitinase ABC digestion of the GAG layer increases bladder permeability in ovariectomized female rats
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DOI：
10.1152/ajprenal.00566.2015
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发表时间：
2016-05-15
影响因子：
4.2
通讯作者：
Greenwood-Van Meerveld, Beverley
中科院分区：
文献类型：
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作者：
Hurst, Robert E.;Van Gordon, Samuel;Greenwood-Van Meerveld, Beverley
尿路上皮保护性不渗透性屏障完整性的丧失已被确定为膀胱功能障碍的重要原因。在这项研究中，我们验证了糖胺聚糖（GAG）的管腔层是屏障功能的重要组成部分的理论。将肽多阳离子硫酸鱼精蛋白（PS） 1 mg/ml滴入大鼠膀胱10 min。另外6只大鼠灌胃63 IU/ml的软骨素酶ABC (Chondroitinase ABC, ChABC) 30 min消化GAG层。未操作的对照组和假注射的对照组也进行了研究。24 h后，将大鼠安乐死，取膀胱，Ussing室评估通透性，并通过fitc标记的葡聚糖（4kda）扩散测量大分子通透性。采用免疫荧光和电镜观察紧密连接状态。在对照组和假手术大鼠膀胱中，经上皮电阻分别为2.5 +/- 1.1、2.6 +/- 1.1、1.2 +/- 0.5和1.01 +/- 0.7 k ω。P = 0.0016和P = 0.0039)。右旋糖酐通透性也有类似差异。组织病理学显示PS治疗后出现轻度炎症，但chabc治疗后的膀胱与对照组没有区别。紧密连接通常保持完整。ChABC消化单独诱导膀胱通透性，证实了GAG层对膀胱屏障功能的重要性，并支持在间质性膀胱炎患者膀胱活检中发现的GAG层缺失可能是至少部分间质性膀胱炎/膀胱疼痛综合征患者产生症状的重要因素。
Loss of integrity of the protective impermeability barrier in the urothelium has been identified as significant in bladder dysfunction. In this study, we tested the theory that the luminal layer of glycosaminoglycans (GAG) serves as an important component of barrier function. The peptide polycation protamine sulfate (PS), 1 mg/ml, was instilled intravesically for 10 min into rat bladders. Chondroitinase ABC (ChABC), 63 IU/ml, was instilled into an additional six rats for 30 min to digest the GAG layer. Unmanipulated controls and sham-injected controls were also performed. After 24 h, the rats were euthanized, the bladders were removed, and permeability was assessed in the Ussing chamber and by diffusion of FITC-labeled dextran (4 kDa) to measure macromolecular permeability. The status of tight junctions was assessed by immunofluorescence and electron microscopy. In control and sham treated rat bladders, the transepithelial electrical resistance were means of 2.5 +/- 1.1 vs. 2.6 +/- 1.1 vs 1.2 +/- 0.5 and 1.01 +/- 0.7 k Omega.cm(2) in the PS-treated and ChABC-treated rat bladders (P = 0.0016 and P = 0.0039, respectively). Similar differences were seen in dextran permeability. Histopathology showed a mild inflammation following PS treatment, but the ChABC-treated bladders were indistinguishable from controls. Tight junctions generally remained intact. ChABC digestion alone induced bladder permeability, confirming the importance of the GAG layer to bladder barrier function and supports that loss of the GAG layer seen in bladder biopsies of interstitial cystitis patients could be a significant factor producing symptoms for at least some interstitial cystitis/painful bladder syndrome patients.