Mesenchymal Stem Cell-Derived Small Extracellular Vesicles Protect Cardiomyocytes from Doxorubicin-Induced Cardiomyopathy by Upregulating Survivin Expression via the miR-199a-3p-Akt-Sp1/p53 Signaling Pathway

Cardiotoxicity is associated with the long-term clinical application of doxorubicin (DOX) in cancer patients. Mesenchymal stem cell-derived small extracellular vesicles (MSC-sEVs) including exosomes have been suggested for the treatment of various diseases, including ischemic diseases. However, the effects and functional mechanism of MSC-sEVs in DOX-induced cardiomyopathy have not been clarified. Here, MSC-sEVs were isolated from murine embryonic mesenchymal progenitor cell (C3H/10T1/2) culture media, using ultrafiltration. H9c2 cardiac myoblast cells were pretreated with MSC-sEVs and then exposed to DOX. For in vivo studies, male C57BL/6 mice were administered MSC-sEVs intravenously, prior to a single dose of DOX (15 mg/kg, intraperitoneal). The mice were sacrificed 14 days after DOX treatment. The results showed that MSC-sEVs protected cardiomyocytes from DOX-induced cell death. H9c2 cells treated with DOX showed downregulation of both phosphorylated Akt and survivin, whereas the treatment of MSC-sEVs recovered expression, indicating their anti-apoptotic effects. Three microRNAs (miRNAs) (miR 199a-3p, miR 424-5p, and miR 21-5p) in MSC-sEVs regulated the Akt-Sp1/p53 signaling pathway in cardiomyocytes. Among them, miR 199a-3p was involved in regulating survivin expression, which correlated with the anti-apoptotic effects of MSC-sEVs. In in vivo studies, the echocardiographic results showed that the group treated with MSC-sEVs recovered from DOX-induced cardiomyopathy, showing improvement of both the left ventricle fraction and ejection fraction. MSC-sEVs treatment also increased both survivin and B-cell lymphoma 2 expression in heart tissue compared to the DOX group. Our results demonstrate that MSC-sEVs have protective effects against DOX-induced cardiomyopathy by upregulating survivin expression, which is mediated by the regulation of Akt activation by miRNAs in MSC-sEVs. Thus, MSC-sEVs may be a novel therapy for the prevention of DOX-induced cardiomyopathy.     

Modeling the effect of γ-irradiation on reducing total bacterial populations in <Emphasis Type="Italic">gochujang</Emphasis> intended for consumption by astronauts in space programs

This study modeled the effect of γ-irradiation on reducing bacterial populations in space gochujang (Korean red pepper paste). The gochujang samples were γ-irradiated at 0, 5, 10, 15, and 20 kGy, and stored under accelerated storage condition (35°C for 10 days). During storage, total bacterial populations in gochujang samples were enumerated on plate count agar (PCA) on day 0, 1, 3, 5, 7, and 10. To calculate maximum specific growth rate (μ_max; log CFU/g/day), lag phase duration (day), low asymptote (Y ₀; log CFU/g), upper asymptote (Y _max; log CFU/g), and surviving cell counts recovered with PCA were fitted to the Baranyi equation. The parameters then were further expressed as a function of irradiation dose. Total bacterial populations in gochujang were decreased to below detection limit (1 log CFU/g) after irradiation (5–20 kGy). The samples irradiated at 5, 10, and 15 kGy then had bacterial cell recovery, but no growth was observed in 20 kGy irradiated samples during accelerated storage. After validation of models, acceptable model performances (B factor=1.15, A factor=1.29, RMSE=1.044, R ²=0.862) were observed. These results indicate that the developed models may be useful in predicting irradiation doses to produce space gochujang.     

Analysis of irradiated jujube (Zizyphus jujuba) by photostimulated luminescence and electron spin resonance spectroscopy

Possibility of photostimulated luminescence (PSL) and electron spin resonance (ESR) to detect γ-irradiation of jujube (Zizyphus jujuba) was investigated. The jujube samples were exposed to γ-irradiation at doses of 1, 3, 5, and 10 kGy. The PSL results showed that jujube exposed to at 1 kGy or more had a photon count of greater than 5,000 count/60 sec (positive), while the non-irradiated jujube yielded a photon count of less than 700 photon count/60 sec (negative). However, physical parameters (light exposure, storage, and thermal treatment) of irradiated jujube samples gave a strong effect on the PSL signal, resulting in decrease of the photon counts from the initial counts. ESR spectroscopy analysis of irradiated jujube revealed specific signals derived from cellulose radicals, and irradiation caused a significant increase in the ESR signal intensity of the jujube samples without any changes in the spectral patterns. Light exposure, storage, and thermal treatment of jujube resulted in significant decreases in the ESR signal intensities of cellulose radicals.     

Application of Gamma Irradiation on Breakdown of Hazardous Volatile N-Nitrosamines

ABSTRACT: Gamma irradiation was applied for the breakdown of the volatile N-nitrosamines (VNAs), nitrosodimethylamine (NDMA), and nitrosopyrrolidine (NPYR). NDMA and NPYR were dissolved in distilled water, dichloromethane, or ethanol, and irradiated at 2.5, 5.0, 7.5, 10, 15, 20, and 25 kGy by gamma ray. Samples were analyzed by GC-TEA. NDMA and NPYR in distilled water and dichloromethane were easily broken at 5 kGy or above. NPYR was the most sensitive to irradiation, while the NDMA is relatively resistant to irradiation. NDMA and NPYR dissolved in ethanol was the most resistant to irradiation and the breakdown was 90% or above at 20 kGy. VNA formation was not observed by in vitro test from decomposed compounds without nitrite, while the VNAs were found by exposure of irradiated products to nitrite. Results indicated that the gamma irradiation technology may be effective to reduce carcinogenic VNA contents in food and other industry.     

Production of Low Salted and Fermented Shrimp by Irradiation

ABSTRACT: Shrimp ( Acetes chinensis ) were sliced, washed, and then salted with 15 and 20% (w/w) sodium chloride. Salted shrimp was 0, 5, and 10 kGy-irradiated at 2 different stages: 1) irradiated immediately after processing salted shrimp, 2) irradiated at optimum fermentation period, and fermented at 15 °C for 10 weeks. Nonirradiated shrimp with 30% salt were also prepared as a control. Irradiated shrimp were not different in proximate composition, salinity, and water activity from nonirradiated shrimp with the same salt addition and the same irradiation time. During fermentation, volatile basic nitrogen (VBN) contents increased as the salt concentration and irradiation dose decreased. From results of sensory analysis, total bacterial count, and pH, the combination of low salt concentration (15% or 20%) and gamma irradiation (5 or 10 kGy) was effective in processing low-salted and fermented shrimp. Results provided no adverse sensory quality and improved micro-bial shelf-stability compared to control (30% of salt addition).     

Irradiation Effects on Biogenic Amines in Korean Fermented Soybean Paste During Fermentation

ABSTRACT: Irradiation effects on biogenic amines (BAs) and microbiological populations of Korean fermented soybean paste were investigated during fermentation. Soybean paste was prepared and irradiated with doses of 5,10, and 15 kGy, and then fermented at 25 °C for 12 wk. Bacillus spp. and lactic‐acid bacteria decreased by irradiation but increased during fermentation. Biogenic amines detected were putrescine, cadaverine, β‐phenylethylamine, spermidine, spermine, tryptamine, histamine, tyramine, and agmatine. A significant difference was not observed in BA content between control and irradiated samples immediately after gamma irradiation. However, 4 kinds of BAs, putrescine, tryptamine, spermidine, and histamine, showed significant reduction by irradiation during fermentation (P < 0.05).     

Effects of γ-irradiation on antioxidant and antimicrobial activities and color of <Emphasis Type="Italic">Ecklonia cava</Emphasis>

Ecklonia cava (EC) was irradiated with γ-rays at doses of 3, 7, and 20 kGy. The extraction yields, total polyphenol content (TPC), DPPH radical scavenging activity, antimicrobial activity, and color of the EC extracts were assessed. The results showed that irradiation caused an increase in the extraction yields of ethanol and water. TPC was found to be significantly increased when EC powder was subjected to irradiation, followed by ethanol and water extraction. However, DPPH radical scavenging and antimicrobial activities were stable under all irradiation conditions. In the heat and pH stability tests, the DPPH radical scavenging activities of EC ethanol extracts were not influenced by irradiation. Irradiation caused an increase in the lightness and redness of EC extracts and decreased the yellowness. In conclusion, γ-irradiation increased the extraction yield and TPC and brightened the color, while maintaining the antioxidant and antimicrobial activities.     

Identification of an emulsifier and conditions for preparing stable nanoemulsions containing the antioxidant astaxanthin

In this study, oil-in-water nanoemulsions of astaxanthin were prepared by high-pressure homogenization. The influence of emulsifying conditions including emulsifier type, concentration, passing time, astaxanthin concentration and coantioxidants were optimized. The stabilities of nanoemulsions were measured using zetasizer, FF-SEM, TEM, colorimeter and particle size analyzer. The mean diameter of the dispersed particles containing astaxanthin ranged from 160 to 190 nm. The size distribution was unimodal and extended from 100 to 200 nm. The nanoemulsions prepared with glyceryl citrate/lactate/linoleate/oleate (glyceryl ester) had smaller particle size and narrower size distribution than the emulsion prepared with hydrogenated lecithin. Stable incorporation of astaxanthin in nanoemulsion was performed and checked using HPLC, FF-SEM and TEM. The nanoemulsion was not significantly affected during storage under light and thermal condition for one month indicating that the nanoemulsion had a zeta potential of less than -41 mV, indicating a stable colloid.