Functional Expression of Piezo1 in Dorsal Root Ganglion (DRG) Neurons

Abstract

Piezo channels are mechanosensitive ion channels. Piezo1 is primarily expressed in nonsensory tissues, whereas Piezo2 is predominantly found in sensory tissues, including dorsal root ganglion (DRG) neurons. However, a recent study demonstrated the intracellular calcium response to Yoda1, a selective Piezo1 agonist, in trigeminal ganglion (TG) neurons. Herein, we investigate the expression of Piezo1 mRNA and protein in mouse and human DRG neurons and the activation of Piezo1 via calcium influx by Yoda1. Yoda1 induces inward currents mainly in small- (<25 μm) and medium-sized (25–35 μm) mouse DRG neurons. The Yoda1-induced Ca2+ response is inhibited by cationic channel blocker, ruthenium red and cationic mechanosensitive channel blocker, GsMTx4. To confirm the specific inhibition of Piezo1, we performed an adeno-associated virus serotype 2/5 (AAV2/5)-mediated delivery of short hairpin RNA (shRNA) into mouse DRG neurons. AAV2/5 transfection downregulates piezo1 mRNA expression and reduces Ca2+ response by Yoda1. Piezo1 also shows physiological functions with transient receptor potential vanilloid 1 (TRPV1) in the same DRG neurons and is regulated by the activation of TRPV1 in mouse DRG sensory neurons. Overall, we found that Piezo1 has physiological functions in DRG neurons and that TRPV1 activation inhibits an inward current induced by Yoda1.

Piezo2 mechanosensitive ion channel is located to sensory neurons and non-neuronal cells in rat peripheral sensory pathway: implications in pain

“…Piezo2 may also integrate mechanical and thermal cues in vertebrate mechanoreceptors [84]. Function of Piezo2 in pain has been interpreted based on the early experimental data showing that PSNs express only Piezo2 but absent in Piezo1; however, recent studies show that functional Piezo1 is also expressed in PSNs [40, 51, 70]. The Piezo isoforms are not known to form Piezo1-Piezo2 hybrid, but co-expression of Piezo1 and Piezo2 in sensory neurons raises an interesting issue of potential functional interactions between these channels.…”

“…However, recent studies also using ISH report that Piezo2 transcripts are expressed in all DRG-PSNs, including most notably the large diameter neurons implicated in mediating touch and proprioception, as well as small-sized nociceptive PSNs [4, 10, 15, 43, 48, 70, 71]. Similarly, single-cell RT-PCR reports that Piezo2 mRNA is detected in 39% of all DRG-PSNs, while new efforts by single-cell RNA sequencing (RNAseq) identify Piezo2 in the majority of mouse DRG-PSNs [51, 72, 83]. Immunohistochemistry (IHC) has observed Piezo2 expression in up to 45∼80% of total PSNs of mouse DRG with high expression in large diameter PSNs, while a recent report describes Piezo2 expression in all PSNs of mouse DRG neurons, including large-diameter myelinated neurons encompassing LTMRs, as well as medium- and small-diameter nociceptors [43, 62, 69, 73].…”

Fabry disease pain: patient and preclinical parallels

“…Specifically, in the DRG sensory neurons, Piezo1/2, TRPV1, TRPA1, ASIC1-3, and BNaC1α have been demonstrated to play a role in mechanotransduction. 56 , 72 , 107 , 143 , 161 Therefore, we hypothesize that identifying mechanically responsive channels that are sensitized in Fabry disease may provide insight into mechanisms of acute or spontaneous pain in Fabry disease. On the molecular level, this could be accomplished through measurement of ion channel expression, posttranslational glycosylation, activity, and changes in response after Gb3/lyso-Gb3 exposure.…”

Decursin Alleviates Mechanical Allodynia in a Paclitaxel-Induced Neuropathic Pain Mouse Model

“…We monitored TRPV1-mediated Ca 2+ in the human TRPV1 stable cell line HEK293, based on the method described by Roh et al [ 12 ]. Human TRPV1 HEK293 stable cells were placed on poly-D-lysine-coated coverslips (Sigma-Aldrich, Milwaukee, WI, USA) and loaded with 2 μM Fura-2 AM (Thermo Fisher Scientific, Waltham, MA, USA) for 40 min at 37 °C in Dulbecco’s Modified Eagle’s Medium (DMEM, Thermo Fisher Scientific, Waltham, MA, USA) and transferred to the chamber.…”