PIEZO1 and TRPV4, which Are Distinct Mechano-Sensors in the Osteoblastic MC3T3-E1 Cells, Modify Cell-Proliferation

Abstract

Mechanical-loading and unloading can modify osteoblast functioning. Ca2+ signaling is one of the earliest events in osteoblasts to induce a mechanical stimulus, thereby demonstrating the importance of the underlying mechanical sensors for the sensation. Here, we examined the mechano-sensitive channels PIEZO1 and TRPV4 were involved in the process of mechano-sensation in the osteoblastic MC3T3-E1 cells. The analysis of mRNA expression revealed a high expression of Piezo1 and Trpv4 in these cells. We also found that a PIEZO1 agonist, Yoda1, induced Ca2+ response and activated cationic currents in these cells. Ca2+ response was elicited when mechanical stimulation (MS), with shear stress, was induced by fluid flow in the MC3T3-E1 cells. Gene knockdown of Piezo1 in the MC3T3-E1 cells, by transfection with siPiezo1, inhibited the Yoda1-induced response, but failed to inhibit the MS-induced response. When MC3T3-E1 cells were transfected with siTrpv4, the MS-induced response was abolished and Yoda1 response was attenuated. Moreover, the MS-induced response was inhibited by a TRPV4 antagonist HC-067047 (HC). Yoda1 response was also inhibited by HC in MC3T3-E1 cells and HEK cells, expressing both PIEZO1 and TRPV4. Meanwhile, the activation of PIEZO1 and TRPV4 reduced the proliferation of MC3T3-E1, which was reversed by knockdown of PIEZO1, and TRPV4, respectively. In conclusion, TRPV4 and PIEZO1 are distinct mechano-sensors in the MC3T3-E1 cells. However, PIEZO1 and TRPV4 modify the proliferation of these cells, implying that PIEZO1 and TRPV4 may be functional in the osteoblastic mechano-transduction. Notably, it is also found that Yoda1 can induce TRPV4-dependent Ca2+ response, when both PIEZO1 and TRPV4 are highly expressed.

Mechanical stretch promotes hypertrophic scar formation through mechanically activated cation channel Piezo1

“…A previous research emphasized that mechanical loading initiates HS formation through activation of fibroblasts survival pathways 31 . Previous studies have also illustrated that Piezo1 mediates mechanical force-induced proliferation of many cell types, including mouse embryonic stem cells 45 , human progenitors 46 , and osteoblastic cells 47 . In this study, our data showed that CMS promotes HDFs proliferation in a Piezo1-mediated manner (Fig.…”

Cross-talk between the calcium channel TRPV4 and reactive oxygen species interlocks adhesive and degradative functions of invadosomes

“…The functions of TRPV4 in invadosome confirmed its generic role in the mechanotransduction processes associated with cell migration of multiple cell types ( Alessandri-Haber et al, 2008 ). In the mechanoresponse of osteoblastic cells, a recent report even suggested that TRPV4 could be more important than the calcium channel Piezo1, thought to be the main channel implicated in mechanotransduction ( Yoneda et al, 2019 ).…”

Piezo Channels: Awesome Mechanosensitive Structures in Cellular Mechanotransduction and Their Role in Bone

“…Subsequent transwell cell migration experiments and cell scratch experiments showed that the number of Piezo1-siRNA cells migrating per well and the rate of scratch healing were significantly reduced, indicating that the Piezo1 gene silencing significantly inhibited the migration ability of MC3T3-E1 osteoblasts [ 81 ]. Meanwhile, Yoneda et al found that Piezo1 activator Yoda1 triggers Ca 2+ influx and promotes proliferation in MC3T3-E1 osteoblasts in vitro [ 82 ]. In vitro, MC3T3-E1 osteoblasts required Piezo1 to adapt to the external mechanical fluid shear stress, thereby inducing osteoblastic Runx2 (Runt-related transcription factor 2) gene expression, partly through the AKT/GSK-3β/β-catenin pathway [ 83 ].…”