A high-throughput electrophysiology assay to study the response of PIEZO1 to mechanical stimulation

Abstract

PIEZO1 channels are mechanically activated cation channels that play a pivotal role in sensing mechanical forces in various cell types. Their dysfunction has been associated with numerous pathophysiological states, including generalized lymphatic dysplasia, varicose vein disease, and hereditary xerocytosis. Given their physiological relevance, investigating PIEZO1 is crucial for the pharmaceutical industry, which requires scalable techniques to allow for drug discovery. In this regard, several studies have used high-throughput automated patch clamp (APC) combined with Yoda1, a specific gating modifier of PIEZO1 channels, to explore the function and properties of PIEZO1 in heterologous expression systems, as well as in primary cells. However, a combination of solely mechanical stimulation (M-Stim) and high-throughput APC has not yet been available for the study of PIEZO1 channels. Here, we show that optimization of pipetting parameters of the SyncroPatch 384 coupled with multihole NPC-384 chips enables M-Stim of PIEZO1 channels in high-throughput electrophysiology. We used this approach to explore differences between the response of mouse and human PIEZO1 channels to mechanical and/or chemical stimuli. Our results suggest that applying solutions on top of the cells at elevated pipetting flows is crucial for activating PIEZO1 channels by M-Stim on the SyncroPatch 384. The possibility of comparing and combining mechanical and chemical stimulation in a high-throughput patch clamp assay facilitates investigations on PIEZO1 channels and thereby provides an important experimental tool for drug development.

The Gárdos Channel and Piezo1 Revisited: Comparison between Reticulocytes and Mature Red Blood Cells

“…One of the putative physiological functions of the Piezo1-Gárdos channel interplay is a volume adaptation, when RBCs need to pass small constrictions like the sinoidal slits in the spleen, which was proposed by several groups [48][49][50]. Indeed, there are a number of facts that support this concept: (i) mechanical stress, like RBCs experience when passing small constrictions, activate Piezo1 [95,96]; (ii) the large gradient of Ca 2+ across the RBC membrane in the order of 20,000 (cp. Table 1) activation of Piezo1 in RBCs results in an increase in intracellular Ca 2+ [60]; (iii) an increase in intracellular Ca 2+ activates the Gárdos channel [73]; and (iv) activation of the Gárdos channel results in dehydration [97].…”