AimMyocardial infarction (MI) is a severe disease with increased mortality and disability rates, posing heavy economic burden for society. Exosomes were uncovered to mediate intercellular communication after MI. This study aims to explore the effect and mechanism of lncRNA KLF3-AS1 in exosomes secreted by human mesenchymal stem cells (hMSCs) on pyroptosis of cardiomyocytes and MI.MethodsExosomes from hMSCs were isolated and identified. Exosomes from hMSCs with transfection of KLF3-AS1 for overexpression were injected into MI rat model or incubated with hypoxia cardiomyocytes. Effect of KLF3-AS1 on MI area, cell viability, apoptosis, and pyroptosis was determined. The relationship among miR-138-5p, KLF3-AS1, and Sirt1 was verified by dual-luciferase reporter assay. Normal cardiomyocytes were transfected with miR-138-5p inhibitor or sh-Sirt1 to clarify whether alteration of miR-138-5p or sh-Sirt1 can regulate the effect of KLF3-AS1 on cardiomyocytes.ResultsExosomes from hMSCs were successfully extracted. Transfection of KLF3-AS1 exosome in rats and incubation with KLF3-AS1 exosome in hypoxia cardiomyocytes both verified that overexpression of KLF3-AS1 in exosomes leads to reduced MI area, decreased cell apoptosis and pyroptosis, and attenuated MI progression. KLF3-AS1 can sponge miR-138-5p to regulate Sirt1 expression. miR-138-5p inhibitor transfection and KLF3-AS1 exosome incubation contribute to attenuated pyroptosis and MI both in vivo and in vitro, while transfection of sh-Sirt1 could reverse the protective effect of exosomal KLF3-AS1 on hypoxia cardiomyocytes.ConclusionLncRNA KLF3-AS1 in exosomes secreted from hMSCs by acting as a ceRNA to sponge miR-138-5p can regulate Sirt1 so as to inhibit cell pyroptosis and attenuate MI progression.

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This article demonstrates theoretical design of ultracompact all-optical AND, NAND, OR, and NOR gates with two-dimensional nonlinear photonic crystal slabs. Compound Ag-polymer film with a low refractive index and large third-order nonlinearity is adopted as our nonlinear material and photonic crystal cavities with a relatively high quality factor of about 2000 is designed on this polymer slab. Numerical simulations show that all-optical logic gates with low pump-power in the order of tens of MW/cm2 can be achieved. These design results may provide very useful schemes and approaches for the realization of all-optical logic gates with low-cost, low-pump-power, high-contrast and ultrafast response-time.

Uncaria rhynchophylla is a component herb of many Chinese herbal formulae for the treatment of neurodegenerative diseases. Previous study in our laboratory has demonstrated that an ethanol extract of Uncaria rhynchophylla ameliorated cognitive deficits in a mouse model of Alzheimer's disease induced by D-galactose. However, the active ingredients of Uncaria rhynchophylla responsible for the anti-Alzheimer's disease activity have not been identified. This study aims to identify the active ingredients of Uncaria rhynchophylla by a bioassay-guided fractionation approach and explore the acting mechanism of these active ingredients by using a well-established cellular model of Alzheimer's disease, beta-amyloid- (Aβ-) induced neurotoxicity in PC12 cells. The results showed that six alkaloids, namely, corynoxine, corynoxine B, corynoxeine, isorhynchophylline, isocorynoxeine, and rhynchophylline were isolated from the extract of Uncaria rhynchophylla. Among them, rhynchophylline and isorhynchophylline significantly decreased Aβ-induced cell death, intracellular calcium overloading, and tau protein hyperphosphorylation in PC12 cells. These results suggest that rhynchophylline and isorhynchophylline are the major active ingredients responsible for the protective action of Uncaria rhynchophylla against Aβ-induced neuronal toxicity, and their neuroprotective effect may be mediated, at least in part, by inhibiting intracellular calcium overloading and tau protein hyperphosphorylation.

Optical fiber-Raman devices integrated with plasmonic nanostructures have promising potentials for in situ probing remote liquid samples and biological samples. In this system, the fiber probe is required to simultaneously demonstrate stable surface enhanced Raman scattering (SERS) signals and high sensitivity toward the target species. Here we demonstrate a generic approach to integrate presynthesized plasmonic nanostructures with tapered fiber probes that are prepared by a dipping-etching method, through reversed electrostatic attraction between the silane couple agent modified silica fiber probe and the nanostructures. Using this approach, both negatively and positively charged plasmonic nanostructures with various morphologies (such as Au nanosphere, Ag nanocube, Au nanorod, Au@Ag core-shell nanorod) can be stably assembled on the tapered silica fiber probes. Attributed to the electrostatic force between the plasmonic units and the fiber surface, the nanostructures do not disperse in liquid samples easily, making the relative standard deviation of SERS signals as low as 2% in analyte solution. Importantly, the detection sensitivity of the system can be optimized by adjusting the cone angle (from 3.6° to 22°) and the morphology of nanostructures assembled on the fiber. Thus, the nanostructures-sensitized optical fiber-Raman probes show great potentials in the applications of SERS-based environmental detection of liquid samples.

The stem with hooks of Uncaria rhynchophylla is a component herb of many traditional formulae for the treatment of neurodegenerative diseases. However, scientific evidence of the efficacy of Uncaria rhynchophylla in the treatment of Alzheimer's disease (AD) in animal models is lacking. Thus, in the present study, we investigated whether the 70 % aqueous ethanol extract of Uncaria rhynchophylla (EUR) could protect against D-galactose (D-gal)-induced cognitive deficits in mice. Mice were given a subcutaneous injection of D-gal (50 mg/kg) and orally administered EUR (100, 200, or 400 mg/kg) daily for 8 weeks. The effect of EUR on D-gal-induced cognitive deficits was evaluated by measuring behavioral and neurochemical parameters of AD and the antioxidant status of brain tissue. The results showed that EUR (200 or 400 mg/kg) significantly increased exploratory behavior (assessed by an open-field test) and improved spatial learning and memory function (assessed by the Morris water maze test) in D-gal-treated mice. In addition, EUR (200 or 400 mg/kg) significantly increased the levels of acetylcholine and glutathione and decreased the activity of acetylcholinesterase and the level of malondialdehyde in the brains of D-gal-treated mice. These results indicate that EUR ameliorates cognitive deficits induced by D-gal in mice, and that this action may be mediated, at least in part, by the inhibition of acetylcholinesterase activity and the enhancement of the antioxidant status of brain tissue.

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