The roles of mechanosensitive ion channels and associated downstream MAPK signaling pathways in PDLC mechanotransduction

Abstract

The present study aimed to investigate whether the cytoskeleton, the Piezo1 ion channel and the transient receptor potential cation channel subfamily V member 4 (TrPV4) ion channel are equally functional in the mechanotransduction of periodontal ligament cells (Pdlcs) and to reveal the interplay of these mechanically sensitive ion channels (MScs). Human Pdlcs (hPdlcs) were pretreated with cytochalasin d (the inhibitor of actin polymerization), GsMTx4 (the antagonist of Piezo1) and GSK205 (the antagonist of TrPV4), and then subjected to periodic mechanical loading. The expression levels of macrophage colony stimulating factor (M-cSF), receptor activator of nF-κB ligand (ranKl) and cyclooxygenase-2 (coX2) in hPdlcs were detected via western blotting. osteoblast mineralization induction capacity of the hPdlcs was also studied and the mitogen-activated protein kinase (MAPK) expression profile was determined via protein microarray. The expression of Piezo1 and TRPV4 in the PDLCs was significantly increased at 8 h after loading. These differences in expression were accompanied by increased expression of M-cSF, ranKl and coX2. compared with the control group, key Pdlc biomarkers were suppressed after mechanical loading following treatment with the inhibitors of Piezo1 (GsMTx4) and TrPV4 (GSK205). The phosphorylated-MAPK protein array showed differential biomarker profiles among all groups. The present study suggested that both MScs and the cytoskeleton participated as mechanical sensors, and did so independently in hPdlc mechanotransduction. Furthermore, the Piezo1 ion channel may transmit mechanical signals via the erK signaling pathway; however, the TrPV4 channel may function via alternative signaling pathways.

TRPV4 Inhibition and CRISPR-Cas9 Knockout Reduce Inflammation Induced by Hyperphysiological Stretching in Human Annulus Fibrosus Cells

“…In human epidermal keratinocytes, TRPV4 blocking reduced IL6 and IL8 production caused by gamma irradiation [37]. Additionally, the stretch-induced upregulation of COX2 expression was decreased by treatment with a TRPV4 antagonist in human periodontal ligament cells [38]. The reduction of stretch-induced PGE2 release in the presence of the TRPV4 antagonist further confirms the reduction in COX2 gene expression.…”

Mechanosensitive Piezo1 in Periodontal Ligament Cells Promotes Alveolar Bone Remodeling During Orthodontic Tooth Movement

“…Piezo1 also exists on the membrane of primary PDL cells ( Jin et al, 2015 ). In vitro studies have confirmed that the Piezo1 ion channel can transmit mechanical signals and regulate both the osteogenic differentiation and osteoclastogenesis of PDL cells via various signaling including extracellular regulated protein kinases (ERK), nuclear factor-kappa B (NF-κB), and Notch1 signaling pathways ( Jin et al, 2015 ; Shen et al, 2020 ; Wang et al, 2020a ). These results suggest the possible mechanotransduction role of Piezo1 in the process of OTM.…”

Mechanistic Insight into Orthodontic Tooth Movement Based on Animal Studies: A Critical Review

“…Ion channels are pore-forming membrane proteins that facilitate direct ion passage through the cell membrane [ 51 ]. Mechanical force-activated ion channels increase membrane permeability and trigger the influx of extracellular calcium, demonstrating their role in mechanotransduction in osteocytes and PDL fibroblasts [ 51 , 128 , 129 ]. Piezo1 ion channel and transient receptor potential cation channel subfamily V member 4 (TRPV4) are key factors in the mechanotransduction of osteocytes and PDL fibroblasts under mechanical loading.…”

“…In vitro mechanical stimulation of mature osteocytes activates Piezo1, which rapidly activates Akt and down-regulates sclerostin [ 131 ]. Piezo1 and TRPV4 increase their expression 8 h after mechanical loading, followed by the increased expression of M-CSF, RANKL and COX2 [ 128 ]. However, pretreatment with the inhibitors of Piezo1 and TRPV4 suppressed the related cytokine expression.…”