Ethanol Increases NADPH Oxidase-derived Oxidative Stress and Induces Apoptosis in Human Liver Adenocarcinoma Cells (SK-HEP-1)

Alcohol-induced liver injury is linked to oxidative stress and increased production of reactive oxygen species (ROS). Oxidative stress is an early event in the process of apoptosis. However, it is not completely understood how ethanol-induced oxidative stress induces apoptosis. In contrast, nicotinamide adenine dinucleotide phosphate oxidase (NOX) is known to generate ROS in hepatocytes. The purpose of the present study was to determine whether or not ethanol-induced ROS generation stimulates the death receptor or mitochondrial pathways of apoptosis in alcohol dehydrogenase containing human liver adenocarcinoma (SK-HEP-1) cells. Treatment with ethanol increased the generation of ROS and expression of NOX4 mRNA, and also induced mitochondrial dysfunction in SK-HEP-1 cells. Moreover, ethanol induced the activation of caspase-8 and -3 in hepatocytes. These activities were suppressed by pretreatment with N-acetyl-cysteine, an antioxidant, or apocynin, an inhibitor of NOX activity. These results suggested that ethanol induces an increase in NOX-derived ROS generation upstream of caspase-8 activation and in the mitochondria in SK-HEP-1 cells. In conclusion, this study demonstrated that ethanol increases the generation of ROS and subsequently induces apoptosis using a mechanism involving mitochondrial dysfunction and caspase activation in SK-HEP-1 cells

Ethanol-induced Stress Leads to Apoptosls Via Endoplasmic Reticulum Stress in SK-Hepl Cells

Alcoholic liver disease causes oxidative stress and induces apoptosis during alcohol metabolism. Ethanol causes endoplasmic reticulum (ER) stress in hepatocytes, stimulating the unfolded protein response (UPR) pathway and/or Ca2+-dependent calpain and caspase-4 activities. However, it is poorly understood whether ethanol-induced oxidative stress directly leads to apoptosis promoted by ER stress-associated pathways. This study investigated this question in human liver adenocarcinoma (SK-Hep1) cells, which were treated with 200 mM ethanol for 5 hours in the presence or absence of the antioxidant N-acetyl-cysteine (NAC). We found that treatment with ethanol significantly increased ROS production and cellular apoptosis in the SK-Hep1 cells, and that this response was significantly suppressed by pretreatment with NAC. Furthermore, pretreatment with NAC significantly reduced the observed increases in the mRNA expressions of Bip, Chop, and sXbp-1, and the activity of caspase-3 in ethanol-induced apoptotic cells. However, pretreatment with NAC did not attenuate the transient rise in cytosolic Ca2+ nor the activities of caspase-4 and calpain induced by ethanol. Together, these results revealed that ethanol-induced stress promotes apoptosis not only through mitochondria-mediated pathways, but also via ER stress. The findings further suggested that ethanol-induced oxidative stress and non-oxidative stress both stimulate the pathway regulating ER stress-mediated apoptosis

Combined Neuroprotective Effects of Propofol and Dexmedetomidine on Endoplasmic Reticulum Stress-mediated Apoptosis in SH-SY5Y Cells

Propofol is a short-acting intravenous anesthetic agent. Dexmedetomidine, a highly selective α2-adrenergic receptor agonist, has a well-known sedative effect. Both agents exhibit cytoprotective effects in the nervous system under ischemic conditions. Recently, the combination of propofol plus dexmedetomidine was used for the sedation of mechanically ventilated patients in an intensive care unit, but there are few experimental reports of the protective effects of the propofol plus dexmedetomidine combination in cells. Meanwhile, intraoperative brain ischemia–reperfusion induces endoplasmic reticulum (ER) stress-mediated apoptosis. The aim of the present study was to clarify molecular details underlying the neuroprotection afforded by the combination of propofol plus dexmedetomidine against thapsigargin (TG)-induced ER stress in human neuroblastoma SH-SY5Y cells, and whether the combination provided more efficient neuroprotection. TG was used to generate ER stress in SH-SY5Y cells. Cells were pretreated with propofol or dexmedetomidine, individually or in combination, for 1 h before cotreatment with TG for 20 h. There was a significant increase in [Ca2+]i, caspase activation, and the expression of ER stress biomarkers in TG-induced apoptotic cells. The increase in [Ca2+]i and the induction of ER stress by TG were suppressed by pretreatment with propofol, dexmedetomidine, and their combination. The dexmedetomidine-induced reduction in caspase activity and ER stress biomarkers was inhibited by pretreatment with an α2-adrenergic receptor antagonist, but was enhanced by pretreatment with a cAMP inhibitor. Treatment with the propofol plus dexmedetomidine combination exhibited the strongest protection against TG-induced apoptosis. These results demonstrate that the combination of propofol plus dexmedetomidine at clinically relevant concentrations suppresses ER stress-induced apoptosis in neuroblastoma SH-SY5Y cells. The findings suggest that the combination of propofol plus dexmedetomidine within a clinically relevant concentration range may be used safely in patients

Neuroprotective Effects of Dexmedetomidine against Thapsigargin-induced ER-stress via Activity of α₂-adrenoceptors and Imidazoline Receptors

Dexmedetomidine is a potent and highly selective α2-adrenoceptor agonist with sedative, analgesic, and sympatholytic properties, though it also exhibits some affinity for imidazoline binding sites. In addition to its sedative effects, dexmedetomidine exerts neuroprotective effects under ischemic conditions. Invasive incidents such as ischemia or hypoxia induce dysfunctions in energy production or depletion of ATP as well as accumulation and aggregation of abnormal proteins in the endoplasmic reticulum (ER), leading to an ER-stress response. In the present study, we examined whether dexmedetomidine exerts inhibitory effects on apoptosis mediated by thapsigargin-induced ER-stress in SH-SY5Y cells, and proposed a possible underlying mechanism for its neuroprotective effects. We used thapsigargin (TG) to generate an ER-stress response in SH-SY5Y cells. SH-SY5Y cells were pretreated with Dex (1–1000 nM) or receptor antagonists (atipamezole, efaroxan, BU99006, and 2’,5’-dideoxyadenosine) for 1 hour before co-treatment with 1 mM TG for 20 hours. Co-incubation with dexmedetomidine suppressed thapsigargin-induced increases in cytosolic Ca2+, caspase-4 and -3 activity, eIF2α phosphorylation, and expression of ER-stress biomarkers. Dexmedetomidine treatment also decreased cAMP levels. In the presence of atipamezole or efaroxan, but not BU99006, inhibition of eIF2α phosphorylation and CHOP expression significantly increased following treatment with dexmedetomidine in thapsigargin-treated cells. However, pretreatment with BU99006 enhanced the increase in mitochondrial membrane potential associated with dexmedetomidine treatment. The results of the present study demonstrate that dexmedetomidine at clinically relevant concentrations suppresses ER-stress-induced apoptosis in SH-SY5Y cells. Some neuroprotective effects of dexmedetomidine may be mediated by α2-adrenoceptor and I1- and I2-receptors

Correction: A multicenter, randomized controlled trial of individualized occupational therapy for patients with schizophrenia in Japan.

[This corrects the article DOI: 10.1371/journal.pone.0193869.]

Propofol Prevents Amyloid-β-Induced Neurotoxicity through Suppression of Cytosolic Ca2＋ and MAPK Signaling Pathway in SH-SY5Y Cells

Alzheimer’s disease （AD） is one of the most common causes of dementia, characterized by the accumulation of amyloid-β （Aβ） peptide deposits in the brain. Within an aging society, elderly patients with preoperative dementia, or those who are affected by postoperative cognitive impairment, are a major health problem. Although inhalation anesthetics induce accumulation of Aβ protein and progression of AD, propofol, a short-acting intravenous anesthetic, has gained increasing attention for its neuroprotective effects following cerebral ischemia. However, the protective action of propofol against Aβ-induced neuronal damage remains unclear. Therefore, the aim of this study was to elucidate the mechanisms underlying the protective effect of propofol against Aβ-induced neurotoxicity. Neural damage was induced in human neuroblastoma cells （SH-SY5Y） using 2.5?M Aβ（1?42）. Cells were pretreated with propofol （1?M） for 1h, followed by further treatment with propofol for 20h in combination with Aβ. In Aβ（1?42）-induced neural damage, caspase-3 activation was increased, as was phosphorylation of p38 mitogen-activated protein kinase （MAPK） and tau. Moreover, cell viability and the phosphorylation of Akt, cAMP response element-binding protein, and Bcl-2 decreased significantly with Aβ treatment. However, these responses were reversed by pretreatment with propofol and p38MAPK inhibitor. The Aβ（1?42）-induced increase in reactive oxygen species generation was inhibited by propofol pretreatment, but remained unchanged following pretreatment with the p38MAPK inhibitor. Furthermore, Aβ（1?42）-treated cells exhibited a significant increase in cytosolic Ca2＋（［Ca2＋］i）, but propofol pretreatment resulted in a significant decrease in ［Ca2＋］i starting 30s after exposure to Aβ（1?42）. Our results indicate that the mechanism underlying the protective effect of propofol against Aβ-induced neurotoxicity is a decrease in ［Ca2＋］i, which subsequently suppresses oxidative stress, along with p38MAPK and tau phosphorylation. Thus, these findings suggest that propofol, at clinically relevant concentrations, is likely to be safe in elderly patients and in those with risk factors for AD

Attitudes toward depression among Japanese non-psychiatric medical doctors: a cross-sectional study

Abstract Background Under-recognition of depression is common in many countries. Education of medical staff, focusing on their attitudes towards depression, may be necessary to change their behavior and enhance recognition of depression. Several studies have previously reported on attitudes toward depression among general physicians. However, little is known about attitudes of non-psychiatric doctors in Japan. In the present study, we surveyed non-psychiatric doctors’ attitude toward depression. Methods The inclusion criteria of participants in the present study were as follows: 1) Japanese non-psychiatric doctors and 2) attendees in educational opportunities regarding depression care. We conveniently approached two populations: 1) a workshop to depression care for non-psychiatric doctors and 2) a general physician-psychiatrist (G-P) network group. We contacted 367 subjects. Attitudes toward depression were measured using the Depression Attitude Questionnaire (DAQ), a 20-item self-report questionnaire developed for general physicians. We report scores of each DAQ item and factors derived from exploratory factor analysis. Results We received responses from 230 subjects, and we used DAQ data from 187 non-psychiatric doctors who met the inclusion criteria. All non-psychiatric doctors (n = 187) disagreed with "I feel comfortable in dealing with depressed patients' needs," while 60 % (n = 112) agreed with "Working with depressed patients is heavy going." Factor analysis indicated these items comprised a factor termed "Depression should be treated by psychiatrists" - to which 54 % of doctors (n = 101) agreed. Meanwhile, 67 % of doctors (n = 126) thought that nurses could be useful in depressed patient support. The three factors derived from the Japanese DAQ differed from models previously derived from British GP samples. The attitude of Japanese non-psychiatric doctors concerning whether depression should be treated by psychiatrists was markedly different to that of British GPs. Conclusions Japanese non-psychiatric doctors believe that depression care is beyond the scope of their duties. It is suggested that educational programs or guidelines for depression care developed in other countries such as the UK are not directly adaptable for Japanese non-psychiatric doctors. Developing a focused educational program that motivates non-psychiatric doctors to play a role in depression care is necessary to enhance recognition and treatment of depression in Japan.</p