[Corrigendum] Ouabain suppresses the growth and migration abilities of glioma U­87MG cells through inhibiting the Akt/mTOR signaling pathway and downregulating the expression of HIF­1α.

Subsequently to the publication of the above paper, an interested reader drew to the authors' attention that several pairings of panels in Fig. 5, as shown on p. 5599, were strikingly similar. After having examined their original data, the authors realized that they uploaded some images incorrectly during the process of compiling this figure, and that there were duplicated data panels in this figure. However, the authors were able to consult their original data, and had access to the correct images. The revised version of Fig. 5, showing the correct data for the Akt/Control, p­Akt/Control, mTOR/0.05 µM Ouabain, HIF­1α/0.05 µM Ouabain and Akt/0.5 µM Ouabain experiments, is shown opposite. Note that the replacement of the erroneous data does not affect either the results or the conclusions reported in this paper, and all the authors agree to this Corrigendum. The authors are grateful to the Editor of Molecular Medicine Reports for granting them this opportunity to publish a Corrigendum, and apologize to the readership for any inconvenience caused. [the original article was published in Molecular Medicine Reports 17: 5595­5600, 2018; DOI: 10.3892/mmr.2018.8587].

Ouabain suppresses the growth and migration abilities of glioma U­87MG cells through inhibiting the Akt/mTOR signaling pathway and downregulating the expression of HIF­1α.

Glioma is one of the most malignant forms of brain tumor, and has been of persistent concern due to its high recurrence and mortality rates, and limited therapeutic options. As a cardiac glycoside, ouabain has widespread applications in congestive heart diseases due to its positive cardiac inotropic effect by inhibiting Na+/K+­ATPase. Previous studies have demonstrated that ouabain has antitumor activity in several types of human tumor, including glioma. However, the exact underlying mechanism remains to be elucidated. The purpose of present study was to elucidate the effect of ouabain on human glioma cell apoptosis and investigate the exact mechanism. U­87MG cells were treated with various concentrations of ouabain for 24 h, following which cell viability and survival rate were assessed using a 3­(4,5-dimethylthiazol-2­yl)­2,5­diphenyltetrazolium bromide assay. The dynamic changes and cell motility were observed using digital holographic microscopy. Additionally, western blot analysis and high­content screening assays were used to detect the protein expression levels of phosphorylated (p­)Akt, mammalian target of rapamycin (mTOR), p­mTOR and hypoxia­inducible factor (HIF)­1α, respectively. Compared with the control group, ouabain suppressed U­87MG cell survival, and attenuated cell motility in a dose­dependent manner (P<0.01). The downregulation of p­Akt, mTOR, p­mTOR and HIF­1α were observed following treatment with 2.5 and 25 µmol/l of ouabain. These results suggested that ouabain exerted suppressive effects on tumor cell growth and motility, leading to cell death via regulating the intracellular Akt/mTOR signaling pathway and inhibiting the expression of HIF­1α in glioma cells. The present study examined the mechanism underlying the antitumor property of ouabain, providing a novel potential therapeutic agent for glioma treatment.

iTRAQ-Based Quantitative Proteomics Reveals the New Evidence Base for Traumatic Brain Injury Treated with Targeted Temperature Management.

This study aimed to investigate the effects of targeted temperature management (TTM) modulation on traumatic brain injury (TBI) and the involved mechanisms using quantitative proteomics technology. SH-SY5Y and HT-22 cells were subjected to moderate stretch injury using the cell injury controller (CIC), followed by incubation at TTM (mild hypothermia, 32°C), or normothermia (37°C). The real-time morphological changes, cell cycle phase distribution, death, and cell viability were evaluated. Moderate TBI was produced by the controlled cortical impactor (CCI), and the effects of TTM on the neurological damage, neurodegeneration, cerebrovascular histopathology, and behavioral outcome were determined in vivo. Results showed that TTM treatment prevented TBI-induced neuronal necrosis in the brain, achieved a substantial reduction in neuronal death both in vitro and in vivo, reduced cortical lesion volume and neuronal loss, attenuated cerebrovascular histopathological damage, brain edema, and improved behavioral outcome. Using an iTRAQ proteomics approach, proteins that were significantly associated with TTM in experimental TBI were identified. Importantly, changes in four candidate molecules (plasminogen [PLG], antithrombin III [AT III], fibrinogen gamma chain [FGG], transthyretin [TTR]) were verified using TBI rat brain tissues and TBI human cerebrospinal fluid (CSF) samples. This study is one of the first to investigate the neuroprotective effects of TTM on the proteome of human and experimental models of TBI, providing an overall landscape of the TBI brain proteome and a scientific foundation for further assessment of candidate molecules associated with TTM for the promotion of reparative strategies post-TBI.

Hypoxia-inducible factor-1 alpha is involved in RIP-induced necroptosis caused by in vitro and in vivo ischemic brain injury.

Necroptosis, a novel type of programmed cell death, is involved in stroke-induced ischemic brain injury. Although studies have sought to explore the mechanisms of necroptosis, its signaling pathway has not yet to be completely elucidated. Thus, we used oxygen-glucose deprivation (OGD) and middle cerebral artery occlusion (MCAO) models mimicking ischemic stroke (IS) conditions to investigate mechanisms of necroptosis. We found that OGD and MCAO induced cell death, local brain ischemia and neurological deficit, while zVAD-fmk (zVAD, an apoptotic inhibitor), GSK'872 (a receptor interacting protein kinase-3 (RIP3) inhibitor), and combined treatment alleviated cell death and ischemic brain injury. Moreover, OGD and MCAO upregulated protein expression of the triggers of necroptosis: receptor interacting protein kinase-1 (RIP1), RIP3 and mixed lineage kinase domain-like protein (MLKL). The upregulation of these proteins was inhibited by GSK'872, combination treatments and RIP3 siRNA but not zVAD treatment. Intriguingly, hypoxia-inducible factor-1 alpha (HIF-1α), an important transcriptional factor under hypoxic conditions, was upregulated by OGD and MCAO. Similar to their inhibitory effects on aforementioned proteins upregulation, GSK'872, combination treatments and RIP3 siRNA decreased HIF-1α protein level. These findings indicate that necroptosis contributes to ischemic brain injury induced by OGD and MCAO and implicate HIF-1α, RIP1, RIP3, and MLKL in necroptosis.