Cleveland State University, Department of Physics, Cleveland, Ohio 44115, USA.
J Biomed Opt. 2010 Jan-Feb;15(1):015005. doi: 10.1117/1.3316378.
Cellular mechanosensation mechanisms have been implicated in a variety of disease states. Specifically in renal tubules, the primary cilium and associated mechanosensitive ion channels are hypothesized to play a role in water and salt homeostasis, with relevant disease states including polycystic kidney disease and hypertension. Previous experiments investigating ciliary-mediated cellular mechanosensation have used either fluid flow chambers or micropipetting to elicit a biological response. The interpretation of these experiments in terms of the "ciliary hypothesis" has been difficult due the spatially distributed nature of the mechanical disturbance-several competing hypotheses regarding possible roles of primary cilium, glycocalyx, microvilli, cell junctions, and actin cytoskeleton exist. I report initial data using optical tweezers to manipulate individual primary cilia in an attempt to elicit a mechanotransduction response-specifically, the release of intracellular calcium. The advantage of using laser tweezers over previous work is that the applied disturbance is highly localized. I find that stimulation of a primary cilium elicits a response, while stimulation of the apical surface membrane does not. These results lend support to the hypothesis that the primary cilium mediates transduction of mechanical strain into a biochemical response in renal epithelia.
细胞机械感觉机制与多种疾病状态有关。具体来说，在肾小管中，初级纤毛和相关的机械敏感离子通道被认为在水和盐稳态中发挥作用，相关疾病状态包括多囊肾病和高血压。以前研究纤毛介导的细胞机械感觉的实验使用流体流动室或微量移液器来引发生物学反应。由于机械干扰的空间分布性质，这些实验在“纤毛假说”方面的解释变得困难——存在几种关于初级纤毛、糖萼、微绒毛、细胞连接和肌动蛋白细胞骨架的可能作用的竞争假说。我报告了使用光学镊子操纵单个初级纤毛以引发机械转导反应（具体为细胞内钙释放）的初步数据。与以前的工作相比，使用激光镊子的优势在于施加的干扰高度集中。我发现刺激初级纤毛会引起反应，而刺激顶端表面膜则不会。这些结果支持这样的假设，即初级纤毛将机械应变转导为肾上皮细胞的生化反应。
