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Sigma-1 receptor (Sig-1r) is a class of orphan receptors, the potential role of which in pancreatic islet cells remains poorly understood. The present study aimed to investigate the role of Sig-1r in islet β-cell proliferation and examine the effects of Sig-1r on islet β-cell injury under lipotoxic conditions. Sig-1r-overexpressing Min6 cells were generated by lentiviral vector transfection. The effect of Sig-1r overexpression on cell proliferation detected by edu staining, cell cycle progression by propidium iodide (Pi), apoptosis by annexin V-aPc/Pi, mitochondrial membrane potential by Mitolite red and cytoplasmic ca 2+ levelsby Fura-2/aM in islet β-cells were measured by flow cytometry. Western blot analysis was used to measure protein expression levels of endoplasmic reticulum (er) stress markers glucose-regulated protein 78 and c/eBP homologous protein, mitochondrial apoptotic proteins Bcl-2-associated X and Bcl-2 and cytochrome c. in addition, aTP levels and insulin secretion were separately measured using aTP assay and mouse insulin eliSa. Mitochondria-associated er membrane (MaM) structures in Min6 cells were then detected using transmission electron microscopy. Protein disulfide isomerase expression and possible colocalization between inositol 1,4,5-trisphosphate receptor and voltage-dependent anion channel 1 were examined using immunofluorescence. Sig-1R overexpression was found to promote β-cell proliferation by accelerating cell cycle progression. Furthermore, Sig-1r overexpression ameliorated the apoptosis rate whilst impairing insulin secretion induced by palmitic acid by relieving er stress and mitochondrial dysfunction in Min6 cells. Sig-1r overexpression also promoted ca 2+ transport between mitochondria and er by increasing the quantity of er adjacent to mitochondria in the 50-nm range. it was concluded that Sig-1r overexpression conferred protective effects on β-cells against lipotoxicity as a result of the promotion of cell proliferation and inhibition of er stress and oxidative stress, by regulating the structure of MaM.

Porous materials have been widely applied for supercapacitors; however, the relationship between the electrochemical behaviors and the spatial structures has rarely been discussed before. Herein, we report a series of porous coordination cage (PCC) flexible supercapacitors with tunable three-dimensional (3D) cavities and redox centers. PCCs exhibit excellent capacitor performances with a superior molecular capacitance of 2510 F mmol–1, high areal capacitances of 250 mF cm–2, and unique cycle stability. The electrochemical behavior of PCCs is dictated by the size, type, and open–close state of the cavities. Both the charge binding site and the charge transportation pathway are unambiguously elucidated for PCC supercapacitors. These findings provide central theoretical support for the “structure–property relationship” for designing powerful electrode materials for flexible energy storage devices.