Piezo1 mediates neuron oxygen-glucose deprivation/reoxygenation injury via Ca2+/calpain signaling

https://doi.org/10.1016/j.bbrc.2019.03.163Get rights and content

Highlights

  • Activation of Piezo1 enhanced OGD/R-induced apoptosis, increase intracellular calcium levels and enhanced calpain activity.

  • Piezo1 activation mediates OGD/R-induced neuron apoptosis through Ca2+/calpain signaling.

Abstract

Objective

We investigated whether Piezo1 could regulate oxygen-glucose deprivation/reoxygenation injury of neurons through Ca2+/calpain signaling.

Methods

Piezo1 expression in rat brain cortex and PC12 cells were confirmed by immunohistochemistry, immunofluorescence and Western blotting. The effects of Yoda1 and GsMTx4 on OGD/R-induced decrease in cell viability, increase in cell apoptosis and activation of downstreaming Ca2+/calpain signaling were investigated. Furthermore, calpain signaling was inhibited by PD151746 to see whether Ca2+/calpain signaling participated in the neurotoxic effects of Piezo1 activation.

Results

Piezo1 expression was increased in rat cerebral cortex after ischemia/reperfusion and in PC12 cells after OGD/R. Activation of Piezo1 by Yoda1 enhanced OGD/R-induced cell viability inhibition, apoptosis, increase intracellular calcium levels and enhanced calpain activity while GsMTx4 showed the opposite effects. The effects of Piezo1 activation on cell viability and apoptosis were reversed by PD151746.

Conclusion

Piezo1 could regulate neuron oxygen-glucose deprivation/reoxygenation injury via activation of Ca2+/calpain signaling.

Introduction

Brian ischemia/reperfusion injury (IRI) is common and even inevitable during some types of surgery such as cardiac surgery and carotid endarterectomy [1,2]. Apoptosis constitutes a major part of neuron death following IRI and various interventions have been tried [3]. However, the treatment efficacy remain unsatisfactory and more new and powerful molecular targets or strategies are still needed [4].

Calcium ion (Ca2+) is a critical regulator of neuron fate during IRI [5]. Calcium overload during reperfusion can induce endoplasmic reticulum stress and neuron apoptosis by activate calpain signaling [6,7] and inhibition of Ca2+/calpain signaling has been thought to be a promising way to counteract brain IRI [8,9].

In 2010, researchers discovered Piezo1 as a mechanical stimulation-, such as membrane stretch, static pressure and shear stress, activated ion channel [10]. Recently, it is found that Piezo channel can also be modulated by voltage and switch to a purely voltage-gated mode [11]. Both modes of activation increased nonselective cation permeability and mainly calcium influx [[11], [12], [13]]. Moreover, a role of Ca2+/calpain signaling in Piezo1-mediated vascular development has been postulated [13,14]. A study also reveals that Piezo1 regulates mechanically activated currents in the Neuro2A cell line [10]. However, whether Piezo1 is expressed in neurons and plays a role in IRI-induced neuron apoptosis is not known. In this study, we first observed that the expression level of Piezo1 was up-regulated after hypoxia/reoxygenation in PC12 cells and rat brain cortex and further explored the role of Piezo-1/Ca2+/calpain signaling in hypoxia/reoxygenation injury.

Section snippets

Cell culture

The neuron-like PC12 cells (highly differentiated) were purchased from Kunming Institute of Zoology (Kunming, China) and cultured in high glucose Dulbecco's modified Eagle's medium (DMEM) containing 10% fetal bovine serum (Gibco, USA), 100 U/mL penicillin and 100 μg/mL streptomycin (Gibco, USA). The cells were incubated in an incubator at 37 °C with saturated humidity and 5% CO2 plus 95% O2. The culture medium was changed every other day and experiments were carried out when the cells adhered

Piezo1 was expressed in adult rat brain cortex and PC12 cells

Immunohistochemical staining showed that Piezo1 was expressed in the cerebral cortex of adult rats (Fig. 1Aa). Immunofluorescence results also confirmed that Piezo1 protein was expressed in adult rat brain cortex and PC12 cells and localized in both the endoplasmic reticulum and the nucleus (Fig. 1Ab and c).

Piezo1 expression was increased in PC12 cells and rat MCAO brain cortex

The expression of Piezo1 was increased in PC12 cells after 24-h reoxygenation as compared with control and cells with other durations of reoxygenation (Fig. 1Ba and b). The following

Discussion

Piezo1 ion channel is a new type of non-selective mechanically sensitive ion channel discovered in recent years. In this study, we explored the role of the Piezo1 in neuron OGD/R injury and found that Piezo1 could regulate the apoptosis of neurons after OGD/R injury through the Ca2+/calpain signaling.

Studies have shown that inhibition of Piezo1 expression in human osteosarcoma (OS) cells could reverse stretch-induced apoptosis and apoptosis-related gene expression [20]. More recently, Yang Q

Disclosure

The authors declare no conflict of interests.

Acknowledgement

This study was supported by National Natural Science Foundation of China (No. 81502182 and No. 81400893), National Natural Science Foundation of Beijing, China (No. 7142169) and CPLA Youth Training Project for Medical Science (17QNP030).

References (28)

  • E.B. Cagmat et al.

    Potential use of calpain inhibitors as brain injury therapy

  • Y. Wang et al.

    Calpain-2 as a therapeutic target for acute neuronal injury

    Expert Opin. Ther. Targets

    (2018)
  • B. Coste et al.

    Piezo1 and Piezo2 are essential components of distinct mechanically activated cation channels

    Science

    (2010)
  • M. Moroni et al.

    Voltage gating of mechanosensitive PIEZO channels

    Nat. Commun.

    (2018)
  • Cited by (0)

    1

    equal contributors.

    View full text