Identification and localization of aquaporin water channels in human salivary glands
Identification and localization of aquaporin water channels in human salivary glands
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DOI：
10.1152/ajpgi.2001.281.1.g247
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发表时间：
2001-07-01
影响因子：
4.5
通讯作者：
Steward, MC
中科院分区：
文献类型：
--
作者：
Gresz, V;Kwon, TH;Steward, MC
水通道蛋白（AQP）水通道在多种液体转运上皮细胞中表达，并可能在唾液分泌中起重要作用。我们的目的是确定和定位水通道蛋白表达在人类唾液腺。从人腮腺、下颌下、舌下腺和唇腺以及人脑中提取总RNA。使用人AQP 1、AQP 3、AQP 4和AQP 5的特异性引物通过RT-PCR评估水通道蛋白mRNA的表达。所有四个水通道蛋白在所有的腺体通过RT-PCR检测，和序列后，进一步扩增与巢式引物进行确认。然后将清洁的PCR产物用作P-32标记的cDNA探针，用于半定量北方印迹分析，使用甘油醛-3-磷酸脱氢酶作为参考。只有AQP 1、AQP 3和AQP 5 mRNA以显著水平存在。AQP的定位通过免疫组织化学确定的石蜡切片使用亲和纯化的第一抗体和过氧化物酶连接的第二抗体。每种唾液腺类型显示了大致相似的染色模式：AQP 1定位于毛细血管内皮细胞和肌上皮细胞; AQP 3存在于粘液和浆液腺泡细胞的基底膜; AQP 4未检测到; AQP 5表达于两种类型腺泡细胞的腔和小管膜。我们的结论是，AQP 3和AQP 5一起可能提供了一个途径，为跨细胞渗透水流动的初级唾液的形成。
Aquaporin (AQP) water channels are expressed in a variety of fluid-transporting epithelia and are likely to play a significant role in salivary secretion. Our aim was to identify and localize the aquaporins expressed in human salivary glands. Total RNA was extracted from human parotid, submandibular, sublingual, and labial glands and from human brain. Expression of aquaporin mRNA was assessed by RT-PCR using specific primers for human AQP1, AQP3, AQP4, and AQP5. All four aquaporins were detected by RT-PCR in all of the glands, and the sequences were confirmed after further amplification with nested primers. Cleaned PCR products were then used as P-32-labeled cDNA probes in a semiquantitative Northern blot analysis using glyceraldehyde-3-phosphate dehydrogenase as reference. Only AQP1, AQP3, and AQP5 mRNAs were present at significant levels. AQP localization was determined by immunohistochemistry on paraffin sections using affinity-purified primary antibodies and peroxidase-linked secondary antibodies. Each salivary gland type showed a broadly similar staining pattern: AQP1 was localized to the capillary endothelium and myoepithelial cells; AQP3 was present in the basolateral membranes of both mucous and serous acinar cells; AQP4 was not detected; and AQP5 was expressed in the luminal and canalicular membranes of both types of acinar cell. We conclude that AQP3 and AQP5 together may provide a pathway for transcellular osmotic water flow in the formation of the primary saliva.