Aims: Age-related lipofuscin N-retinylidene-N-retinylethanolamine (A2E) accumulated in human retinal pigment epithelium (RPE) cells confers susceptibility to blue light-mediated damage, which represents one pathogenesis of age-related macular degeneration. This study investigated the expression of 2 best-characterized endoplasmic reticulum (ER) stress markers, glucose-related protein 78 (GRP78) and C/EBP homologous protein (CHOP), as well as their regulation by oxidative stress after blue light-mediated damage of A2E-containing RPE cells. Methods: ARPE-19 cells were incubated with A2E (10, 25, 50 μM) for 2 h and exposed to blue light for 20 min. A2E distributions in RPE cells were assessed via laser scanning confocal microscope and liquid chromatography-mass spectrometry. Cell viability was measured by a Cell Titer 96 Aqueous One Solution cell proliferation assay. The quantity of intracellular reactive oxygen species (ROS) was detected by dihydroethidium fluorescence using flow cytometry. Expressions of GRP78 and CHOP were measured at both mRNA and protein levels. To examine the role of oxidative stress in regulating GRP78 and CHOP expression, RPE cells were pretreated with the antioxidant N-acetylcysteine (NAC) for 2 h. RNA interference of GRP78 performed by short hairpin RNA was used to evaluate the effect of GRP78 in blue light-mediated damage of RPE cells. Results: After blue light exposure, A2E-treated RPE cells showed a gradual decrease in cell viability and a particular increase in ROS levels. Meanwhile, the expressions of GRP78 and CHOP in A2E-treated RPE cells were significantly increased at different time points after illumination. Pretreatment with NAC attenuated the expression of 2 ER stress markers, especially CHOP in A2E and blue light-treated RPE cells. Silencing of GRP78 by RNA interference upregulated CHOP and caspase-12 expression as well as aggravated the blue light-mediated damage of A2E-laden RPE cells. Conclusion: RPE cells exhibited ROS accumulation and subsequent elevation of GRP78 and CHOP expression after A2E and blue light-induced damage. The ROS scavenger NAC diminished ER stress protein expression, suggesting a connection between ER and oxidative stress in blue light-mediated damage of A2E-containing RPE cells. Besides, GRP78 may play a protective role in it.
Manganese sulfides (MnS) are particularly appealing electrode candidates for lithium/sodium‐ion batteries, because of their low cost, wide availability, and environmental benignity. Herein, well‐defined Mn(OH)(OCH3) nanoflakes are synthesized for the first time, whereby two‐dimensional (2D) porous α‐MnS and its composite with N, S co‐doped carbon (α‐MnS@NSC) are produced via the topologic sulfurization of Mn(OH)(OCH3) or a Mn(OH)(OCH3)@polydopamine intermediate. The electrochemical lithium/sodium‐storage properties of α‐MnS are most likely governed by the conductivity, and thus can be significantly enhanced through integrating with conductive carbon coating. As a result, α‐MnS@NSC outperforms the bare α‐MnS and most of the reported MnS‐based anodes, demonstrating the high reversible capacities (1275 mA h g−1 at 0.2 A g−1 for LIBs and 581 mA h g−1 at 0.1 A g−1 for SIBs), great rate capability, and long cyclabilities. This work showcases both a novel strategy to fabricate 2D manganese‐based compounds and a preferred architecture for high performance lithium/sodium‐ion batteries.
The Front Cover illustrates 2D α‐MnS‐based anode materials for lithium/sodium‐ion batteries. The characteristic 2D porous structure of α‐MnS together with conductive carbon shells endow N, S co‐doped carbon coated α‐MnS composite with great Li‐/Na‐ion storage performance. More information can be found in the Research Article by X. Chen et al.
Invited for this issue's Front Cover is the group of Professor Feng Peng from School of Chemistry and Chemical Engineering, Guangzhou University (China). The cover picture illustrates 2D α‐MnS‐based anode materials for lithium/sodium‐ion batteries. The characteristic 2D porous structure of α‐MnS together with conductive carbon shells endow N, S co‐doped carbon coated α‐MnS composite with great Li‐/Na‐ion storage performance. Read the full text of the Research Article at 10.1002/celc.202200738.
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