Adenylyl cyclase isoform V mediates renin release from juxtaglomerular cells
Adenylyl cyclase isoform V mediates renin release from juxtaglomerular cells
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DOI：
10.1161/01.hyp.0000255172.84842.d2
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发表时间：
2007-03-01
期刊：
影响因子：
8.3
通讯作者：
Beierwaltes, William H.
中科院分区：
文献类型：
--
作者：
Ortiz-Capisano, M. Cecilia;Ortiz, Pablo A.;Beierwaltes, William H.
我们以前已经证明，肾小球细胞内钙离子减少，cAMP的形成和肾素的释放都增加。我们假设，这是因为细胞内钙和腺苷酸环化酶，V型钙代谢异构体之间的相互作用。我们使用的原代培养物的肾小球细胞分离自C-57/B6小鼠在70%至80%的汇合。使用抗腺苷酸环化酶的2种钙代谢异构体（V型和VI型）中任一种的抗体对分离的肾小球细胞进行Western印迹。只有抗腺苷酸环化酶-V的抗体在120 kDa处产生了预期的强条带。免疫标记在肾小球细胞与共聚焦显微镜发现免疫荧光的腺苷酸环化酶-V-特异性抗体相比，无论是阴性对照或细胞染色的腺苷酸环化酶-VI抗体。用100 μ mol/L胞浆钙螯合剂BAPTA-AM降低离体肾小球细胞内钙，（每毫克蛋白质3.49 +/- 0.70至10.09 +/- 0.81 pmol/mL; P < 0.002）和肾素释放（1001.8 +/- 81.5至1648.0 +/- 139.1 ng血管紧张素I/ml/h/mg蛋白; P < 0.01）。选择性腺苷酸环化酶-V抑制剂NKY 80完全阻断BAPTA-AM刺激的cAMP形成和肾素释放。我们的结论是，降低细胞内钙是允许的，允许增加活动的钙代谢异构体腺苷酸环化酶-V（但不是腺苷酸环化酶-VI）在肾小球细胞，产生cAMP，刺激肾素分泌。
We have shown previously that decreasing intracellular calcium in the juxtaglomerular cells increases both cAMP formation and renin release. We hypothesized that this is because of an interaction between intracellular calcium and the calcium-inhibitable isoform of adenylyl cyclase, type-V. We used primary cultures of juxtaglomerular cells isolated from C-57/B6 mice at 70% to 80% confluence. Western blots were performed on isolated juxtaglomerular cells using antibodies against either of the 2 calcium inhibitable isoforms of adenylyl cyclase, types-V and -VI. Only the antibody against adenylyl cyclase-V gave us a strong band at 120 kDa as expected. Immunolabeling in juxtaglomerular cells with confocal microscopy found immunofluorescence for the adenylyl cyclase-V-specific antibody compared with either negative controls or cells stained with the adenylyl cyclase-VI antibody. Reducing isolated juxtaglomerular intracellular calcium with 100 mu mol/L of the cytosolic calcium chelator BAPTA-AM stimulated both cAMP (3.49 +/- 0.70 to 10.09 +/- 0.81 pmol/mL per milligram of protein; P < 0.002) and renin release (1001.8 +/- 81.5 to 1648.0 +/- 139.1 ng of angiotensin I per milliliter per hour per milligram of protein; P < 0.01). The selective adenylyl cyclase-V inhibitor NKY80 completely blocked both BAPTA-AM-stimulated cAMP formation and renin release. We conclude that lowering intracellular calcium is permissive, allowing an increased activity of the calcium-inhibitable isoform adenylyl cyclase-V (but not adenylyl cyclase-VI) in the juxtaglomerular cell, producing cAMP, which stimulates renin secretion.