Inhibitory effects of AG490 on H2O2-induced TRPM2-mediated Ca2+ entry

Shimizu, Shunichi; Yonezawa, Ryo; Hagiwara, Takaaki; Yoshida, Takashi; Takahashi, Nobuaki; Hamano, Satoshi; Negoro, Takaharu; Toda, Takahiro; Wakamori, Minoru; Mori, Yasuo; Ishii, Masakazu

doi:10.1016/j.ejphar.2014.08.023

Cited by 21 publications

(7 citation statements)

References 55 publications

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“…In the present study, JAK2 knockdown by JAK2 siRNA significantly reduced cytosolic Ca 2+ concentrations. This finding is in agreement with the results of a previous study which demonstrated that AG490, the JAK2 signal inhibitor, blocked an H 2 O 2 -induced increase in intracellular Ca 2+ in U937 cells ( 32 ). It has been recognised that XO activation is regulated by cytosolic Ca 2+ , and an unidentified Ca 2+ -dependent protease is involved in the cleavage of XDH to XO ( 11 ).…”

Section: Discussionsupporting

confidence: 93%

Hepatocyte growth factor inhibits hypoxia/reoxygenation-induced activation of xanthine oxidase in endothelial cells through the JAK2 signaling pathway

Zhang

Chen

et al. 2016

International Journal of Molecular Medicine

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Vascular endothelial cells (ECs) appear to be one of the primary targets of hypoxia/reoxygenation (H/R) injury. In our previous study, we demonstrated that hepatocyte growth factor (HGF) exhibited a protective effect in cardiac microvascular endothelial cells (CMECs) subjected to H/R by inhibiting xanthine oxidase (XO) by reducing the cytosolic Ca2+ concentration increased in response to H/R. The precise mechanisms through which HGF inhibits XO activation remain to be determined. In the present study, we examined the signaling pathway through which HGF regulates Ca2+ concentrations and the activation of XO during H/R in primary cultured rat CMECs. CMECs were exposed to 4 h of hypoxia and 1 h of reoxygenation. The protein expression of XO and the activation of the phosphoinositide 3-kinase (PI3K), janus kinase 2 (JAK2) and p38 mitogen-activated protein kinase (p38 MAPK) signaling pathways were detected by western blot analysis. Cytosolic calcium (Ca2+) concentrations and reactive oxygen species (ROS) levels were measured by flow cytometry. The small interfering RNA (siRNA)-mediated knockdown of XO inhibited the increase in ROS production induced by H/R. LY294002 and AG490 inhibited the H/R-induced increase in the production and activation of XO. The PI3K and JAK2 signaling pathways were activated by H/R. The siRNA-mediated knockdown of PI3K and JAK2 also inhibited the increase in the production of XO protein. HGF inhibited JAK2 activation whereas it had no effect on PI3K activation. The siRNA-mediated knockdown of JAK2 prevented the increase in cytosolic Ca2+ induced by H/R. Taken together, these findings suggest that H/R induces the production and activation of XO through the JAK2 and PI3K signaling pathways. Furthermore, HGF prevents XO activation following H/R primarily by inhibiting the JAK2 signaling pathway and in turn, inhibiting the increase in cytosolic Ca2+.

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Section: Discussionsupporting

confidence: 93%

Hepatocyte growth factor inhibits hypoxia/reoxygenation-induced activation of xanthine oxidase in endothelial cells through the JAK2 signaling pathway

Zhang

Chen

et al. 2016

International Journal of Molecular Medicine

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“…In this study, we show that AG490, a specific JAK2 inhibitor, and HO-3867, a specific STAT3 inhibitor, abrogates the inhibitory effect of IL-6 on TRPM7 current. This finding is consistent with several reports that demonstrate the role of JAK2 in the regulation of ion-channel activity [ 35 – 38 ]. Because IL-6 modulates TRPM7 current with fast kinetics, we speculate that the effect of IL-6 signaling on TRPM7 may result from JAK2−STAT3 mediated phosphorylation of TRPM7, or another direct interaction between IL-6R signal transducers and TRPM7.…”

Section: Discussionsupporting

confidence: 94%

Regulation of TRPM7 Function by IL-6 through the JAK2-STAT3 Signaling Pathway

Liu¹,

Zhao²,

Wang³

et al. 2016

PLoS ONE

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AimsPrevious studies have demonstrated that expression of the TRPM7 channel, which may induce delayed cell death by mediating calcium influx, is precisely regulated. However, functional regulation of TRPM7 channels by endogenous molecules has not been elucidated. The proinflammatory cytokine IL-6 contributes to regulation of Ca2+ influx in cerebral ischemia, but the role of IL-6 in regulating TRPM7 functioning is unknown. Thus, we here investigated the interaction between IL-6 and TRPM7 channels and the relevant mechanisms.Materials and MethodsUsing whole-cell patch-clamping, we first investigated the effect of IL-6 on TRPM7-like currents in primary cultured cortical neurons. Next, TRPM7-overexpressing HEK293 cells were used to confirm the effect of IL-6/sIL-6R on TRPM7. Finally, we used specific signaling pathway inhibitors to investigate the signaling pathways involved.ResultsIL-6 or IL-6/sIL-6R dose-dependently inhibited inward TRPM7 currents, in both primary cultured neurons and HEK293 cells overexpressing TRPM7. In intracellular Mg2+-free conditions, extracellular Ca2+ or the α-kinase domain of TRPM7 did not participate in this regulation. The inhibitory effect of IL-6 on TRPM7 could be blocked by specific inhibitors of the JAK2−STAT3 pathway, but not of the PI3K, ERK1/2, or PLC pathways.ConclusionsIL-6 inhibits the inward TRPM7 current via the JAK2−STAT3 signaling pathway.

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“…3), suggesting that it attenuates H 2 O 2 -induced TRPM2 activation by affecting its pore region. TRPA1 and TRPV1 are also oxidative stress-sensitive Ca 21 permeable channels (Andersson et al, 2008;Takahashi et al, 2008;Chuang and Lin, 2009;Shimizu et al, 2014). However, duloxetine did not affect H 2 O 2 -induced In the sham group and each I + R group, vehicle or duloxetine (10 mg/kg, i.p.)…”

Section: Discussionmentioning

confidence: 95%

“…We examined the effects of duloxetine on other transient receptor potential channels, which are activated by oxidative stress or possess a similar pore region to TRPM2 channels. TRPA1 and TRPV1 are oxidative stress-sensitive channels that are activated by H 2 O 2 (Andersson et al, 2008;Takahashi et al, 2008;Chuang and Lin, 2009;Shimizu et al, 2014). The addition of H 2 O 2 to TRPA1/HEK or TRPV1/HEK cells increased [Ca 21 ] i .…”

Section: Duloxetine Attenuates Brain Injury Via Trpm2 Inhibitionmentioning

confidence: 99%

Protective Effects of Duloxetine against Cerebral Ischemia-Reperfusion Injury via Transient Receptor Potential Melastatin 2 Inhibition

Toda

Yamamoto

Umehara

et al. 2018

J Pharmacol Exp Ther

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Activation of transient receptor potential melastatin 2 (TRPM2), an oxidative stress-sensitive Ca 21 -permeable channel, contributes to the aggravation of cerebral ischemia-reperfusion (CIR) injury. Recent studies indicated that treatment with the antidepressant duloxetine for 24 hours (long term) attenuates TRPM2 activation in response to oxidative stress in neuronal cells. To examine the direct effects of antidepressants on TRPM2 activation, we examined their short-term (0-30 minutes) treatment effects on H 2 O 2 -induced TRPM2 activation in TRPM2expressing human embryonic kidney 293 cells using the Ca 21 indicator fura-2. Duloxetine exerted the strongest inhibitory effects on TRPM2 activation among the seven antidepressants tested. These inhibitory effects appeared to be due to the inhibition of H 2 O 2 -induced TRPM2 activation via an open-channel blocking-like mechanism, because duloxetine reduced the sustained phase but not the initial phase of increases in intracellular Ca 21 concentrations. In a whole-cell patch-clamp study, duloxetine reduced the TRPM2-mediated inward current during the channel opening state. We also examined the effects of duloxetine in a mouse model of CIR injury. The administration of duloxetine to wild-type mice attenuated CIR injury, similar to that in Trpm2 knockout (KO) mice. The administration of duloxetine did not reduce CIR injury further in Trpm2 KO mice, suggesting that it exerts neuroprotective effects against CIR injury by inhibiting TRPM2 activation. Regarding drug repositioning, duloxetine may be a useful drug in reperfusion therapy for ischemic stroke because it has already been used clinically in therapeutics for several disorders, including depression.

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Inhibitory effects of AG490 on H2O2-induced TRPM2-mediated Ca2+ entry

Cited by 21 publications

References 55 publications

Hepatocyte growth factor inhibits hypoxia/reoxygenation-induced activation of xanthine oxidase in endothelial cells through the JAK2 signaling pathway

Hepatocyte growth factor inhibits hypoxia/reoxygenation-induced activation of xanthine oxidase in endothelial cells through the JAK2 signaling pathway

Regulation of TRPM7 Function by IL-6 through the JAK2-STAT3 Signaling Pathway

Protective Effects of Duloxetine against Cerebral Ischemia-Reperfusion Injury via Transient Receptor Potential Melastatin 2 Inhibition

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