Enhancement of HGF-induced tubulogenesis by endothelial cell-derived GDNF
Enhancement of HGF-induced tubulogenesis by endothelial cell-derived GDNF
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DOI：
10.1371/journal.pone.0212991
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发表时间：
2019-03
期刊：
影响因子：
3.7
通讯作者：
M. Nakasatomi;Shunsuke Takahashi;T. Sakairi;H. Ikeuchi;Y. Kaneko;K. Hiromura;Y. Nojima;A. Maeshima-A.-Maes
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文献类型：
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作者：
M. Nakasatomi;Shunsuke Takahashi;T. Sakairi;H. Ikeuchi;Y. Kaneko;K. Hiromura;Y. Nojima;A. Maeshima-A.-Maes
肾小管发生是肾器官发生和损伤后肾小管再生过程中的重要环节，是上皮细胞组织成小管结构的过程。在目前的研究中，使用体外人类小管生成系统检测了调节小管形成的内皮细胞衍生因子。当人肾近端小管上皮细胞(RPTECs)在凝胶中培养时，在肝细胞生长因子(HGF)的存在下，可以诱导出具有管腔的管状结构。水通道蛋白1定位于这些肾小管结构的顶膜，提示这些结构在形态上与活体肾小管相当。HGF诱导的小管形成在与人脐静脉内皮细胞(HUVECs)或HUVEC条件培养液(HUVEC-CM)共同培养时显著增强。HUVECs与HUVECs共培养，在缺乏HGF的情况下，不能诱导出管状结构。磷酸化受体酪氨酸激酶阵列显示，与未加入HUVEC-CM相比，HUVEC-CM显著增强HGF诱导的肾小管结构中胶质细胞源性神经营养因子(GDNF)受体Ret的磷酸化。HUVECs产生GDNF，RPTECs同时表达Ret和GDNF家族受体α1(共受体)。加入GDNF可显著促进HGF诱导的小管形成。有趣的是，不仅HGF而且GDNF都能显著诱导HGF受体Met的磷酸化。这些数据表明，内皮细胞来源的GDNF增强了HGF的小管生成特性，并可能在肾小管形成和损伤后肾小管再生过程中的上皮-内皮串扰中发挥关键作用。
Tubulogenesis, the organization of epithelial cells into tubular structures, is an essential step during renal organogenesis as well as during the regeneration process of renal tubules after injury. In the present study, endothelial cell-derived factors that modulate tubule formation were examined using an in vitro human tubulogenesis system. When human renal proximal tubular epithelial cells (RPTECs) were cultured in gels, tubular structures with lumens were induced in the presence of hepatocyte growth factor (HGF). Aquaporin 1 was localized in the apical membrane of these tubular structures, suggesting that these structures are morphologically equivalent to renal tubules in vivo. HGF-induced tubule formation was significantly enhanced when co-cultured with human umbilical vein endothelial cells (HUVECs) or in the presence of HUVEC-conditioned medium (HUVEC-CM). Co-culture with HUVECs did not induce tubular structures in the absence of HGF. A phospho-receptor tyrosine kinase array revealed that HUVEC-CM markedly enhanced phosphorylation of Ret, glial cell-derived neurotrophic factor (GDNF) receptor, in HGF-induced tubular structures compared to those without HUVEC-CM. HUVECs produced GDNF, and RPTECs expressed both Ret and GDNF family receptor alpha1 (co-receptor). HGF-induced tubule formation was significantly enhanced by addition of GDNF. Interestingly, not only HGF but also GDNF significantly induced phosphorylation of the HGF receptor, Met. These data indicate that endothelial cell-derived GDNF potentiates the tubulogenic properties of HGF and may play a critical role in the epithelial-endothelial crosstalk during renal tubulogenesis as well as tubular regeneration after injury.