Search

Sphingomyelin synthase 2 (SMS2) is a vital contributor to tissue injury and affects various pathological processes. However, whether SMS2 participates in the modulation of cardiac injury in myocardial infarction has not been determined. This study aimed to evaluate the potential role of SMS2 in the regulation of cardiomyocyte injury induced by hypoxia, an in vitro model for studying myocardial infarction. Our data revealed that SMS2 expression was significantly upregulated in cardiomyocytes in response to hypoxia. Loss-of-function experiments revealed that knockdown of SMS2 markedly restored the viability of cardiomyocytes impaired by hypoxia, and attenuated hypoxia-evoked apoptosis and reactive oxygen species (ROS) generation. In contrast, cardiomyocytes that highly expressed SMS2 were more sensitive to hypoxia-induced injury. Moreover, SMS2 deficiency enhanced the activation of nuclear factor erythroid 2-related factor 2 (Nrf2) signaling through inactivation of glycogen synthase kinase-3β. Notably, suppression of Nrf2 markedly abrogated SMS2 knockdown-mediated cardioprotective effects on hypoxia-exposed cardiomyocytes. Our results illustrate that downregulation of SMS2 exerts a cardioprotective function by protecting cardiomyocytes from hypoxia-induced apoptosis and oxidative stress through enhancement of Nrf2 activation. Our study indicates a potential role of SMS2 in the modulation of cardiac injury, which may contribute to the progression of myocardial infarction. [ABSTRACT FROM AUTHOR]

Fucoxanthin (Fx), a xanthophyll carotenoid abundant in brown algae, possesses several biological functions, such as antioxidant, anti-inflammatory, and cardiac-protective activities. However, the role of Fx in myocardial ischemia/reperfusion (MI/R) is still unclear. Thus, the aim of this study was to investigate the effect of Fx on MI/R-induced injury and explore the underlying mechanisms. Our results showed that in vitro, Fx treatment significantly suppressed inflammatory response, oxidative stress, and apoptosis in rat cardiomyocytes exposed to hypoxia/reoxygenation (H/R). In addition, Fx led to increased phosphorylation of AMPK, AKT, and GSK-3β, and enhanced activation of Nrf2 in cardiomyocytes under H/R conditions. Notably, pretreatment with Compound C (AMPK inhibitor), partially reduced the beneficial effects of Fx in cardiomyocytes exposed to H/R. In vivo, Fx ameliorated myocardial damage, inhibited inflammatory response, oxidative stress, and apoptosis, and activated the AMPK/GSK-3β/Nrf2 signaling in myocardial tissues in MI/R rat model. Taken together, these findings indicated that Fx attenuates MI/R-induced injury by inhibiting oxidative stress, inflammatory response, and apoptosis. The AMPK/GSK-3β/Nrf2 pathway is involved in the cardioprotective effect of Fx in MI/R injury. Thus, Fx may be a promising drug for the treatment of MI/R., (© 2024 John Wiley & Sons Ltd.)

In this paper, the influence of the active layer nanomorphology on device performance for ternary PbS(x)Se(1-x) quantum dot-based solution-processed infrared photodetector is presented. Firstly, ternary PbS(x)Se(1-x) quantum dots (QDs) in various chemical composition were synthesized and the bandgap of the ternary PbS(x)Se(1-x) QDs can be controlled by the component ratio of S/(S + Se), and then field-effect transistor (FET) based photodetectors Au/PbS0.4Se0.6:P3HT/PMMA/Al, in which ternary PbS0.4Se0.6 QDs doped with poly(3-hexylthiophene) (P3HT) act as the active layer and poly(methyl methacrylate) (PMMA) as the dielectric layer, were presented. By changing the weight ratio of P3HT to PbS0.4Se0.6 QDs (K = M(P3HT):M(QDs)) in dichlorobenzene solution, we found that the device with K = 2:1 shows optimal electrical property in dark; however, the device with K = 1:2 demonstrated optimal performance under illumination, showing a maximum responsivity and specific detectivity of 55.98 mA W(-1) and 1.02 × 10(10) Jones, respectively, at low V(DS) = -10 V and V(G) = 3 V under 980 nm laser with an illumination intensity of 0.1 mW cm(-2). By measuring the atomic force microscopy phase images of PbS0.4Se0.6:P3HT films in different weight ratio K, our experimental data show that the active layer nanomorphology has a great influence on the device performance. Also, it provides an easy way to fabricate high performance solution-processed infrared photodetector.