Loss of apical monocilia on collecting duct principal cells impairs ATP secretion across the apical cell surface and ATP-dependent and flow-induced calcium signals.
Loss of apical monocilia on collecting duct principal cells impairs ATP secretion across the apical cell surface and ATP-dependent and flow-induced calcium signals.
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DOI：
10.1007/s11302-007-9072-0
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发表时间：
2008-06
影响因子：
3.5
通讯作者：
Schwiebert EM
中科院分区：
文献类型：
--
作者：
Hovater MB;Olteanu D;Hanson EL;Cheng NL;Siroky B;Fintha A;Komlosi P;Liu W;Satlin LM;Bell PD;Yoder BK;Schwiebert EM
肾上皮细胞在基础条件下组成性释放ATP，并响应刺激释放更大量的嘌呤核苷酸。ATP在肾小球滤过，由沿着肾单位的上皮细胞分泌，并由致密斑细胞分泌，用于反馈信号到肾小球内的传入小动脉，在肾脏内具有重要的生理信号作用。在常染色体隐性遗传性多囊肾病（ARPKD）小鼠和人类中，集合管上皮细胞缺乏顶端中央纤毛或在该单纤毛内表达功能失调的蛋白质。来源于橡树岭多囊肾（orpkTg 737）小鼠ARPKD模型的集合管主细胞缺乏被认为是感觉细胞器的良好形成的顶端中央纤毛。我们比较了这些细胞生长的极化细胞单层渗透支持相同的细胞，其中顶端单纤毛是遗传拯救野生型Tg 737基因编码北极星，蛋白质纤毛形成必不可少的。在基础条件下的组成型ATP释放是低的，并没有不同的突变体与获救的单层。然而，基因拯救的主细胞单层释放ATP三至五倍更强劲地响应于离子霉素。主细胞单层与完全形成的顶端单纤毛响应三至五倍，低渗比突变体单层缺乏单纤毛。在支持的想法，即单眼是感觉细胞器，故意苛刻的吸移液介质直接到中心的单层诱导ATP释放的基因拯救的单层，具有顶端单眼。然而，机械刺激对缺乏顶端中央单纤毛的突变orpk集合管主细胞单层的效果要差得多。我们的数据还表明，增加胞质游离Ca 2+引发的ATP池，释放响应机械刺激。低渗细胞肿胀和机械移液刺激似乎也触发了常见ATP池的释放。纤毛主管单层响应流量与细胞外和细胞内商店来源的细胞Ca 2+的增加。这种流动诱导的Ca 2+信号在纤毛缺陷的单层中不太稳健。两种制剂中的流动诱导的Ca 2+信号被细胞外钆和细胞外腺苷三磷酸双磷酸酶（ATP酶/ADAPASE）衰减。两者合计，这些数据表明，顶端单丝是感觉细胞器，它们的存在，在顶端膜促进形成一个成熟的ATP分泌装置响应化学，渗透和机械刺激。纤毛和自分泌ATP信号似乎协同工作来控制细胞Ca 2+。纤毛专用的自分泌嘌呤能信号系统的丧失可能是ARPKD的关键潜在病因，并可能导致多种钠（Na+）吸收机制的去抑制和/或上调，并导致ARPKD和其他疾病中的严重高血压表型。
Renal epithelial cells release ATP constitutively under basal conditions and release higher quantities of purine nucleotide in response to stimuli. ATP filtered at the glomerulus, secreted by epithelial cells along the nephron, and released serosally by macula densa cells for feedback signaling to afferent arterioles within the glomerulus has important physiological signaling roles within kidneys. In autosomal recessive polycystic kidney disease (ARPKD) mice and humans, collecting duct epithelial cells lack an apical central cilium or express dysfunctional proteins within that monocilium. Collecting duct principal cells derived from an Oak Ridge polycystic kidney (orpkTg737) mouse model of ARPKD lack a well-formed apical central cilium, thought to be a sensory organelle. We compared these cells grown as polarized cell monolayers on permeable supports to the same cells where the apical monocilium was genetically rescued with the wild-type Tg737 gene that encodes Polaris, a protein essential to cilia formation. Constitutive ATP release under basal conditions was low and not different in mutant versus rescued monolayers. However, genetically rescued principal cell monolayers released ATP three- to fivefold more robustly in response to ionomycin. Principal cell monolayers with fully formed apical monocilia responded three- to fivefold greater to hypotonicity than mutant monolayers lacking monocilia. In support of the idea that monocilia are sensory organelles, intentionally harsh pipetting of medium directly onto the center of the monolayer induced ATP release in genetically rescued monolayers that possessed apical monocilia. Mechanical stimulation was much less effective, however, on mutant orpk collecting duct principal cell monolayers that lacked apical central monocilia. Our data also show that an increase in cytosolic free Ca2+ primes the ATP pool that is released in response to mechanical stimuli. It also appears that hypotonic cell swelling and mechanical pipetting stimuli trigger release of a common ATP pool. Cilium-competent monolayers responded to flow with an increase in cell Ca2+ derived from both extracellular and intracellular stores. This flow-induced Ca2+ signal was less robust in cilium-deficient monolayers. Flow-induced Ca2+ signals in both preparations were attenuated by extracellular gadolinium and by extracellular apyrase, an ATPase/ADPase. Taken together, these data suggest that apical monocilia are sensory organelles and that their presence in the apical membrane facilitates the formation of a mature ATP secretion apparatus responsive to chemical, osmotic, and mechanical stimuli. The cilium and autocrine ATP signaling appear to work in concert to control cell Ca2+. Loss of a cilium-dedicated autocrine purinergic signaling system may be a critical underlying etiology for ARPKD and may lead to disinhibition and/or upregulation of multiple sodium (Na+) absorptive mechanisms and a resultant severe hypertensive phenotype in ARPKD and, possibly, other diseases.
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影响因子：
4.7
作者：
Giaroni, C;Knight, GE;Burnstock, G
通讯作者：
Burnstock, G
DOI：
10.1152/ajpgi.00355.2003
发表时间：
2004-04-01
影响因子：
4.5
作者：
Gatof, D;Kilic, G;Fitz, JG
通讯作者：
Fitz, JG
DOI：
10.1152/ajprenal.1996.270.5.f798
发表时间：
1996-05-01
期刊：
AMERICAN JOURNAL OF PHYSIOLOGY-RENAL FLUID AND ELECTROLYTE PHYSIOLOGY
影响因子：
--
作者：
Ma, HP;Ling, BN
通讯作者：
Ling, BN
影响因子：
3.7
作者：
Frame, MK;deFeijter, AW
通讯作者：
deFeijter, AW
影响因子：
21.3
作者：
Koulen, P;Cai, YQ;Somlo, S
通讯作者：
Somlo, S