Hydrogen Sulfide Protects against Chemical Hypoxia-Induced Cytotoxicity and Inflammation in HaCaT Cells through Inhibition of ROS/NF-κB/COX-2 Pathway

Hydrogen sulfide (H2S) has been shown to protect against oxidative stress injury and inflammation in various hypoxia-induced insult models. However, it remains unknown whether H2S protects human skin keratinocytes (HaCaT cells) against chemical hypoxia-induced damage. In the current study, HaCaT cells were treated with cobalt chloride (CoCl2), a well known hypoxia mimetic agent, to establish a chemical hypoxia-induced cell injury model. Our findings showed that pretreatment of HaCaT cells with NaHS (a donor of H2S) for 30 min before exposure to CoCl2 for 24 h significantly attenuated CoCl2-induced injuries and inflammatory responses, evidenced by increases in cell viability and GSH level and decreases in ROS generation and secretions of IL-1β, IL-6 and IL-8. In addition, pretreatment with NaHS markedly reduced CoCl2-induced COX-2 overexpression and PGE2 secretion as well as intranuclear NF-κB p65 subunit accumulation (the central step of NF-κB activation). Similar to the protective effect of H2S, both NS-398 (a selective COX-2 inhibitor) and PDTC (a selective NF-κB inhibitor) depressed not only CoCl2-induced cytotoxicity, but also the secretions of IL-1β, IL-6 and IL-8. Importantly, PDTC obviously attenuated overexpression of COX-2 induced by CoCl2. Notably, NAC, a ROS scavenger, conferred a similar protective effect of H2S against CoCl2-induced insults and inflammatory responses. Taken together, the findings of the present study have demonstrated for the first time that H2S protects HaCaT cells against CoCl2-induced injuries and inflammatory responses through inhibition of ROS-activated NF-κB/COX-2 pathway

Distress Disclosure and Psychological Functioning Among Taiwanese Nationals and European Americans: The Moderating Roles of Mindfulness and Nationality

Research using Western samples shows that talking about unpleasant emotions—distress disclosure—is associated with fewer psychological symptoms and higher well-being. These benefits of distress disclosure may or may not be observed in East Asia where emotional control is valued. Instead, mindfulness may be more relevant to emotion regulation in East Asia (e.g., Taiwan). In the present study, cultural context (Taiwanese nationals vs. European Americans) and mindfulness were examined as moderators of the relation between distress disclosure and both depression symptoms and life satisfaction. A sample of 256 Taiwanese college students and a sample of 209 European American college students completed self-report measures in their native language. Moderated multiple regression analyses revealed significant interaction effects of mindfulness and distress disclosure on both depression symptoms and life satisfaction for Taiwanese participants but not for European Americans. Specifically, distress disclosure was negatively associated with depression symptoms and positively associated with life satisfaction for Taiwanese low in mindfulness but not for Taiwanese high in mindfulness. For European Americans, distress disclosure was not associated with depression symptoms but was associated with higher life satisfaction, regardless of one’s level of mindfulness. These findings suggest that the potential benefits of disclosing distress are a function of one’s cultural context as well as, for those from Taiwan, one’s mindfulness. (PsycInfo Database Record (c) 2020 APA, all rights reserved

T Cell Tolerance to a Neo-Self Antigen Expressed by Thymic Epithelial Cells: the Soluble Form Is More Effective Than the Membrane-Bound Form

We have previously shown that transgenic (Tg) mice expressing either soluble or membrane-bound hen egg lysozyme (sHEL or mHEL, respectively) under control of the αA-crystallin promoter develop tolerance due to thymic expression of minuscule amounts of H