Nuclear protein 1 promotes unfolded protein response during endoplasmic reticulum stress, and alleviates apoptosis induced by cisplatin in non-small cell lung cancer cells

Purpose: To investigate the role of nuclear protein 1 (NUPR1) in the drug resistance of non-small cell lung cancer (NSCLC) and its regulatory mechanisms. Methods: Quantitative polymerase chain reaction (qPCR) and immunoblot assays were conducted to determine NUPR1 expression in A549 cells. Cisplatin sensitivity and cisplatin-induced apoptosis were investigated in NUPR1 knockdown or overexpressed cells via 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay and flow cytometry. The potential association between unfolded protein response (UPR) and NUPR1 levels in response to cisplatin were explored. The effect of endoplasmic reticulum (ER) stress on apoptosis was examined using flow cytometry. Results: Cisplatin treatment promoted the expression of NUPR1 in NSCLC cells. NUPR1 regulated cisplatin resistance in NSCLC and also regulated UPR in ER stress induced by cisplatin. The results show NUPR1 regulated apoptosis induced by ER stress following tunicamycin treatment. Conclusion: NSCLC cells may promote the UPR in ER stress by promoting the expression of NUPR1, thereby reducing the ER stress induced by cisplatin

The Inhalation Anesthetic Desflurane Induces Caspase Activation and Increases Amyloid β-Protein Levels under Hypoxic Conditions*

Perioperative factors including hypoxia, hypocapnia, and certain anesthetics have been suggested to contribute to Alzheimer disease (AD) neuropathogenesis. Desflurane is one of the most commonly used inhalation anesthetics. However, the effects of desflurane on AD neuropathogenesis have not been previously determined. Here, we set out to assess the effects of desflurane and hypoxia on caspase activation, amyloid precursor protein (APP) processing, and amyloid β-protein (Aβ) generation in H4 human neuroglioma cells (H4 naïve cells) as well as those overexpressing APP (H4-APP cells). Neither 12% desflurane nor hypoxia (18% O2) alone affected caspase-3 activation, APP processing, and Aβ generation. However, treatment with a combination of 12% desflurane and hypoxia (18% O2) (desflurane/hypoxia) for 6 h induced caspase-3 activation, altered APP processing, and increased Aβ generation in H4-APP cells. Desflurane/hypoxia also increased levels of β-site APP-cleaving enzyme in H4-APP cells. In addition, desflurane/hypoxia-induced Aβ generation could be reduced by the broad caspase inhibitor benzyloxycarbonyl-VAD. Finally, the Aβ aggregation inhibitor clioquinol and γ-secretase inhibitor L-685,458 attenuated caspase-3 activation induced by desflurane/hypoxia. In summary, desflurane can induce Aβ production and caspase activation, but only in the presence of hypoxia. Pending in vivo confirmation, these data may have profound implications for anesthesia care in elderly patients, and especially those with AD