MicroRNA-145 suppresses ROS-induced Ca2+ overload of cardiomyocytes by targeting CaMKIIδ.

A change in intracellular free calcium (Ca(2+)) is a common signaling mechanism of reperfusion-induced cardiomyocyte death. Calcium/calmodulin dependent protein kinase II (CaMKII) is a critical regulator of Ca(2+) signaling and mediates signaling pathways responsible for functions in the heart including hypertrophy, apoptosis, arrhythmia, and heart disease. MicroRNAs (miRNA) are involved in the regulation of cell response, including survival, proliferation, apoptosis, and development. However, the roles of miRNAs in Ca(2+)-mediated apoptosis of cardiomyocytes are uncertain. Here, we determined the potential role of miRNA in the regulation of CaMKII dependent apoptosis and explored its underlying mechanism. To determine the potential roles of miRNAs in H2O2-mediated Ca(2+) overload, we selected and tested 6 putative miRNAs that targeted CaMKIIδ, and showed that miR-145 represses CaMKIIδ protein expression and Ca(2+) overload. We confirmed CaMKIIδ as a direct downstream target of miR-145. Furthermore, miR-145 regulates Ca(2+)-related signals and ameliorates apoptosis. This study demonstrates that miR-145 regulates reactive oxygen species (ROS)-induced Ca(2+) overload in cardiomyocytes. Thus, miR-145 affects ROS-mediated gene regulation and cellular injury responses.

Susceptibility of Listeria monocytogenes biofilms and planktonic cultures to hydrogen peroxide in food processing environments.

Recent studies have indicated that Listeria monocytogenes formed biofilms on the surface of food processing equipment, and may survive sanitization treatments. The purpose of this study was to compare the susceptibility of L. monocytogenes grown in either a biofilm or planktonic culture when exposed to hydrogen peroxide (H(2)O(2)). Twelve strains of biofilm-forming L. monocytogenes and their planktonic counterparts were treated with various concentrations of H(2)O(2) (1, 6, and 10%), and the cell survival was then determined at 10-min exposure intervals. When grown as a biofilm, L. monocytogenes was significantly more resistant to H(2)O(2) than under planktonic culture conditions. Planktonic L. monocytogenes strains exhibited significantly different susceptibility to 1% H(2)O(2). Equally interestingly, biofilms of the 12 L. monocytogenes strains also inhibited different survival rates after being treated with 6 and 10% H(2)O(2). However, most of the biofilms recovered to a population of 2-9 log CFU/glass fiber filter (GFF) after a 24-h re-growth period. These results indicate that there was no significant correlation between the H(2)O(2) resistance of biofilm- and planktonic-cultured cells, and suggest that different mechanisms for the resistance to sanitation or disinfection underly the persistence of certain strains in food-processing environments.

Evaluation of whole pork belly qualitative and quantitative properties using selective belly muscle parameters.

The objective of this study was to identify parameters for the evaluation of pork belly quality (composition) and quantity (volume) and to develop regression equations that predict properties of whole pork belly. Through an image analysis of 648 bellies, newly characterized pork belly parameters were developed for evaluating pork belly quality and quantity. Importantly, the estimated muscle volume showed high positive correlation with the whole belly volume and the whole belly muscle percentage (r=0.458, and 0.654, respectively). Section 7 was identified as the best section for the evaluation of pork belly based on the muscle area in every vertebra. A stepwise regression showed that cutaneous trunci muscle (CTM) had an r2 of 0.624 in the model, and supplementation with the other muscles yielded an r2 of 0.784. Therefore, we propose that a prediction equation could be developed for a certain area in the belly for the evaluation of pork belly quantity and quality. The results could be applied to select breeding stock using techniques such as ultrasound with the aim of producing hogs with large as well as lean bellies.

Evaluation of the Digestibility of Korean Hanwoo Beef Cuts Using the in vitro Physicochemical Upper Gastrointestinal System.

The aim of this study was to investigate the digestibility of different Korean Hanwoo beef cuts using an in vitro digestion model, in vitro physicochemical upper gastrointestinal system (IPUGS). The four most commonly consumed cuts - tenderloin, sirloin, brisket and flank, and bottom round - were chosen for this study. Beef samples (75 g) were cooked and ingested into IPUGS, which was composed of mouth, esophagus, and stomach, thereby simulating the digestion conditions of humans. Digested samples were collected every 15 min for 4 h of simulation and their pH monitored. Samples were visualized under a scanning electron microscope (SEM) to examine changes in the smoothness of the surface after digestion. Analysis of the amino acid composition and molecular weight (MW) of peptides was performed using reverse-phase high performance liquid chromatography and sodium dodecyl sulfate polyacrylamide gel electrophoresis, respectively. Following proteolysis by the gastric pepsin, beef proteins were digested into peptides. The amount of peptides with higher MW decreased over the course of digestion. SEM results revealed that the surface of the digested samples became visibly smoother. Total indispensable and dispensable amino acids were the highest for the bottom round cut prior to digestion simulation. However, the total amount of indispensable amino acids were maximum for the tenderloin cut after digestion. These results may provide guidelines for the elderly population to choose easily digestible meat cuts and products to improve their nutritional and health status.

Purification and Anti-pathogenic Properties of Immunoglobulin Concentrates from Porcine Blood.

During slaughtering, animal blood is typically discarded, resulting in water pollution. However, this discarded blood has valuable components, such as immunoglobulin (Ig). Although several studies have been conducted to develop methods for effective recycling of slaughterhouse blood, they have not been commercially utilized in Korea. Here, we extracted an Ig-rich fraction from porcine blood that was then subjected to various in vitro tests, including pathogen growth inhibition, antigenic cross-reactivity, and anti-toxin activity. The porcine immunoglobulin concentrate (PIC) was effectively purified by eliminating other components, such as albumin, and consisted of approximately 63.2±2.9% IgG and 7.2±0.4% IgM on a protein basis. The results showed that it significantly suppressed the growth of pathogenic bacteria, and bound to all tested pathogens, including both gram-positive and gram-negative species, although the degree of activity differed according to strain. The PIC bound to two types of lipopolysaccharide (LPS) obtained from Escherichia coli O111:B4 and Salmonella enterica serotype typhimurium in a concentration-dependent manner. In addition, the PIC restored the proliferation activity of the lymphoblast K-562 cells when co-incubated with pathogenic LPS. These results confirm that the PIC prepared in this study is a potentially valuable functional food material or diet supplement as an alternative to antibiotics that can protect animals from pathogenic bacteria.

Hypoallergenic and Physicochemical Properties of the A2 ß-Casein Fractionof Goat Milk.

Goat milk has a protein composition similar to that of breast milk and contains abundant nutrients, but its use in functional foods is rather limited in comparison to milk from other sources. The aim of this study was to prepare a goat A2 ß-casein fraction with improved digestibility and hypoallergenic properties. We investigated the optimal conditions for the separation of A2 ß-casein fraction from goat milk by pH adjustment to pH 4.4 and treating the casein suspension with calcium chloride (0.05 M for 1 h at 25°C). Selective reduction of ß-lactoglobulin and αs-casein was confirmed using sodium dodecyl sulphate-polyacrylamide gel electrophoresis and reverse-phase high-performance liquid chromatography. The hypoallergenic property of A2 ß-casein fraction was examined by measuring the release of histamine and tumor necrosis factor alpha from HMC-1 human mast cells exposed to different proteins, including A2 ß-casein fraction. There was no significant difference in levels of both indicators between A2 ß-casein treatment and the control (no protein treatment). The A2 ß-casein fraction is abundant in essential amino acids, especially, branched-chain amino acids (leucine, valine, and isoleucine). The physicochemical properties of A2 ß-casein fraction, including protein solubility and viscosity, are similar to those of bovine whole casein which is widely used as a protein source in various foods. Therefore, the goat A2 ß-casein fraction may be useful as a food material with good digestibility and hypoallergenic properties for infants, the elderly, and people with metabolic disorders.

Hydrolysis by Alcalase Improves Hypoallergenic Properties of Goat Milk Protein.

Goat milk is highly nutritious and is consumed in many countries, but the development of functional foods from goat milk has been slow compared to that for other types of milk. The aim of this study was to develop a goat milk protein hydrolysate (GMPH) with enhanced digestibility and better hypoallergenic properties in comparison with other protein sources such as ovalbumin and soy protein. Goat milk protein was digested with four commercial food-grade proteases (separately) under various conditions to achieve the best hydrolysis of αs -casein and ß-lactoglobulin. It was shown that treatment with alcalase (0.4%, 60℃ for 30 min) effectively degraded these two proteins, as determined by SDS-PAGE, measurement of nonprotein nitrogen content, and reverse-phase high-performance liquid chromatography. Hydrolysis with alcalase resulted in a significant decrease in ß-lactoglobulin concentration (almost to nil) and a ~40% reduction in the level of αs-casein. Quantification of histamine and TNF-α released from HMC-1 cells (human mast cell line) showed that the GMPH did not induce an allergic response when compared to the control. Hence, the GMPH may be useful for development of novel foods for infants, the elderly, and convalescent patients, to replace cow milk.

In Vitro Effects of Dietary Inulin on Human Fecal Microbiota and Butyrate Production.

Administration of dietary fibers has various health benefits, mainly by increasing numbers of beneficial bacteria and enhancing production of short-chain fatty acids in the colon. There has been growing interest in the addition of dietary fiber to human diet, due to its prebiotic effects. This study aimed to evaluate the prebiotic activity of inulin using an in vitro batch fermentation system with human fecal microbiota. Fermentation of inulin resulted in a significantly greater ratio of Lactobacillus or Bifidobacteria to Enterobacteria strains as an index of healthy human intestine and elevated butyrate concentration, which are related to improvement of gut health.

Butyrate modulates bacterial adherence on LS174T human colorectal cells by stimulating mucin secretion and MAPK signaling pathway.

BACKGROUND/OBJECTIVES: Fermentation of dietary fiber results in production of various short chain fatty acids in the colon. In particular, butyrate is reported to regulate the physical and functional integrity of the normal colonic mucosa by altering mucin gene expression or the number of goblet cells. The objective of this study was to investigate whether butyrate modulates mucin secretion in LS174T human colorectal cells, thereby influencing the adhesion of probiotics such as Lactobacillus and Bifidobacterium strains and subsequently inhibiting pathogenic bacteria such as E. coli. In addition, possible signaling pathways involved in mucin gene regulation induced by butyrate treatment were also investigated. MATERIALS/METHODS: Mucin protein content assay and periodic acid-Schiff (PAS) staining were performed in LS174T cells treated with butyrate at various concentrations. Effects of butyrate on the ability of probiotics to adhere to LS174T cells and their competition with E. coli strains were examined. Real time polymerase chain reaction for mucin gene expression and Taqman array 96-well fast plate-based pathway analysis were performed on butyrate-treated LS174T cells. RESULTS: Treatment with butyrate resulted in a dose-dependent increase in mucin protein contents in LS174T cells with peak effects at 6 or 9 mM, which was further confirmed by PAS staining. Increase in mucin protein contents resulted in elevated adherence of probiotics, which subsequently reduced the adherent ability of E. coli. Treatment with butyrate also increased transcriptional levels of MUC3, MUC4, and MUC12, which was accompanied by higher gene expressions of signaling kinases and transcription factors involved in mitogen-activated protein kinase (MAPK) signaling pathways. CONCLUSIONS: Based on our results, butyrate is an effective regulator of modulation of mucin protein production at the transcriptional and translational levels, resulting in changes in the adherence of gut microflora. Butyrate potentially stimulates the MAPK signaling pathway in intestinal cells, which is positively correlated with gut defense.

Effects of perilla oil on plasma concentrations of cardioprotective (n-3) fatty acids and lipid profiles in mice.

The aim of this study was to examine the effects of perilla oil as well as several vegetable oils, including flaxseed oil, canola oil, and rice bran oil on plasma levels of cardioprotective (n-3) polyunsaturated fatty acids in mice by feeding each vegetable oil for a period of eight weeks. Concentrations of docosapentaenoic acid (DHA) and eicosapentaenoic acid (EPA), fish-based (n-3) polyunsaturated fatty acids, showed an increase in the plasma of mice fed perilla and flaxseed oils compared to those of mice in the control group (P < 0.05), whereas rice bran and canola oils did not alter plasma DPA and EPA concentrations. Arachidonic acid concentration was increased by feeding rice bran oil (P < 0.05), but not canola, flaxseed, or perilla oil. In addition, oleic acid, linoleic acid, and docosahexaenoic acid concentrations were altered by feeding dietary rice bran, canola, perilla, and flaxseed oils. Findings of this study showed that perilla oil, similar to flaxseed oil, is cardioprotective and could be used as an alternative to fish oil or even flaxseed oil in animal models.

Effect of antioxidant activity in kimchi during a short-term and over-ripening fermentation period.

This study evaluated the antioxidant activities of kimchi at different fermentation times: short-term fermented kimchi (SK; less than 7days) and over-ripened kimchi (OK; greater than 2 years). In conclusion, antioxidant activity of the OK was significantly higher than the SK. The results of this study suggested that there was an increase in the antioxidant activity of fermented kimchi during the fermentation and ripening processes.