Variable Expression of Neural Cell Adhesion Molecule Isoforms in Renal Tissue: Possible Role in Incipient Renal Fibrosis.
Variable Expression of Neural Cell Adhesion Molecule Isoforms in Renal Tissue: Possible Role in Incipient Renal Fibrosis.
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DOI：
10.1371/journal.pone.0137028
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Müller GA
中科院分区：
文献类型：
--
作者：
Marković-Lipkovski J;Životić M;Müller CA;Tampe B;Ćirović S;Vještica J;Tomanović N;Zeisberg M;Müller GA
先前已在正常成人肾间质内描述了罕见的神经细胞粘附分子（NCAM）阳性细胞，推测它们可能在早期间质性肾纤维化（IRF）的间质中增加。在本研究中，在93份各种肾脏疾病的活检样本中，62.4%的病例检测到NCAM+间质细胞。与正常肾组织和晚期 IRF 阶段相比，仅在早期 IRF 中观察到 NCAM+ 细胞数量显着增加 (p<0.001)，与基础疾病无关 (p = 0.657)。所有三种主要 NCAM 亚型的 RT-PCR 条带在正常肾脏或早期 IRF 肾脏中均可见，尽管通过 qRT-PCR 测量的 mRNA 表达水平不同。对通过激光捕获显微切割获得的纯 NCAM+ 细胞群应用 qRT-PCR，在初始 IRF 内的 NCAM+ 细胞中发现 NCAM140kD 同种型的 mRNA 显着过表达（p = 0.004），而 NCAM120kD 和 NCAM180kD 同种型没有显着变化（分别为 p = 0.750；p = 0.704）。同时，qRT-PCR 还显示，初始 IRF 的 NCAM+ 细胞内 αSMA (p = 0.014) 和 SLUG (p = 0.004) mRNA 显着上调，以及基质金属蛋白酶 (MMP) -2 和 -9 mRNA 高度下降（分别为 p = 0.028；p = 0.036）。然而，使用双重免疫荧光仍然可以在初始 IRF 内的罕见 NCAM+ 细胞中检测到 MMP-9 的蛋白质水平。通过双重免疫荧光标记对 NCAM+ 细胞进行进一步表征，揭示了它们与参与纤维化的分子的关联。成纤维细胞生长因子受体 1 (FGFR1) 和 α5β1 整合素在早期 IRF 区域的 NCAM+ 细胞上广泛表达，而人附睾蛋白 4 (HE4) 被发现存在于正常和早期纤维化间质的少数 NCAM+ 细胞中。正常和初期 IRF 中 NCAM+ 间质细胞的异质性，涉及与纤维化相关的分子和 NCAM 亚型的可变表达，可能表明 NCAM+ 细胞在病变肾脏的稳态和肾纤维化调节中发挥不同的作用。
Rare neural cell adhesion molecule (NCAM) positive cells have been previously described within the normal human adult kidney interstitium, speculating that they could increase in the interstitium with incipient interstitial renal fibrosis (IRF). In the present study, among 93 biopsy samples of various kidney diseases, NCAM+ interstitial cells were detected in 62.4% cases. An increased number of NCAM+ cells was significantly observed only in incipient IRF compared to normal renal tissues and advanced IRF stages (p<0.001), independently of underlying diseases (p = 0.657). All three major NCAM isoforms’ RT-PCR bands were visible either in normal or in kidneys with incipient IRF, albeit their mRNA expression levels measured by qRT-PCR were different. Applying qRT-PCR on pure NCAM+ cells population, obtained by laser capture microdissection, significant mRNA over-expression of NCAM140kD isoform was found in NCAM+ cells within incipient IRF (p = 0.004), while NCAM120kD and NCAM180kD isoforms were not changed significantly (p = 0.750; p = 0.704; respectively). Simultaneously, qRT-PCR also showed significant αSMA (p = 0.014) and SLUG (p = 0.004) mRNAs up-regulation within the NCAM+ cells of incipient IRF, as well as highly decreased matrix metalloproteinases (MMP) -2 and -9 mRNAs (p = 0.028; p = 0.036; respectively). However, using double immunofluorescence MMP-9 could still be detectable on the protein level in rare NCAM+ cells within the incipient IRF. Further characterization of NCAM+ cells by double immunofluorescent labeling revealed their association with molecules involved in fibrosis. Fibroblast growth factor receptor 1 (FGFR1) and α5β1 integrin were extensively expressed on NCAM+ cells within the incipient IRF areas, whereas human epididymis protein-4 (HE4) was found to be present in few NCAM+ cells of both normal and interstitium with incipient fibrosis. Heterogeneity of NCAM+ interstitial cells in normal and incipient IRF, concerning molecules related to fibrosis and variable expression of NCAM isoforms, could suggest diverse role of NCAM+ cells in homeostasis and in regulation of renal fibrosis in diseased kidneys.