Nag Subhra, Resnick Andrew
Department of Biology, Geology, and Environmental Sciences, Cleveland State University, Cleveland, Ohio.
Department of Biology, Geology, and Environmental Sciences, Cleveland State University, Cleveland, Ohio;
Am J Physiol Renal Physiol. 2017 Sep 1;313(3):F706-F720. doi: 10.1152/ajprenal.00172.2017. Epub 2017 Jun 21.
Primary cilia have been called "the forgotten organelle" for over 20 yr. As cilia now have their own journal and several books devoted to their study, perhaps it is time to reconsider the moniker "forgotten organelle." In fact, during the drafting of this review, 12 relevant publications have been issued; we therefore apologize in advance for any relevant work we inadvertently omitted. What purpose is yet another ciliary review? The primary goal of this review is to specifically examine the evidence for and against the hypothesized flow-sensing function of primary cilia expressed by differentiated epithelia within a kidney tubule, bringing together differing disciplines and their respective conceptual and experimental approaches. We will show that understanding the biophysics/biomechanics of primary cilia provides essential information for understanding any potential role of ciliary function in disease. We will summarize experimental and mathematical models used to characterize renal fluid flow and incident force on primary cilia and to characterize the mechanical response of cilia to an externally applied force and discuss possible ciliary-mediated cell signaling pathways triggered by flow. Throughout, we stress the importance of separating the effects of fluid shear and stretch from the action of hydrodynamic drag.
二十多年来，初级纤毛一直被称为“被遗忘的细胞器”。如今，纤毛有了自己的期刊，还有几本专门研究纤毛的书籍，也许是时候重新审视“被遗忘的细胞器”这个称谓了。事实上，在撰写这篇综述期间，已经发表了12篇相关出版物；因此，对于我们无意中遗漏的任何相关工作，我们提前表示歉意。为什么还要进行另一篇关于纤毛的综述呢？这篇综述的主要目标是专门研究支持和反对肾小管内分化上皮细胞表达的初级纤毛具有假定的流量感知功能的证据，汇集不同学科及其各自的概念和实验方法。我们将表明，理解初级纤毛的生物物理学/生物力学为理解纤毛功能在疾病中的任何潜在作用提供了重要信息。我们将总结用于表征肾液流和初级纤毛上的入射力以及表征纤毛对外部施加力的机械响应的实验和数学模型，并讨论由流动触发的可能的纤毛介导的细胞信号通路。在整个过程中，我们强调区分流体剪切和拉伸的影响与流体动力阻力作用的重要性。
