Annotation of AMP-activated protein kinase genes and its comparative transcriptional analysis between high and low lipid producing strains of Mucor circinelloides.

BACKGROUND: AMP-activated protein kinase (AMPK) is an important regulator for lipid accumulation, potentially known to have an inhibitory role in lipid synthesis. It inactivates acetyl-CoA carboxylase (ACC), an important regulatory enzyme required for lipid synthesis. However, in Mucor circinelloides, AMPK and its association with lipid accumulation has not been studied yet. OBJECTIVES: To identify AMPK genes in M. circinelloides and to compare their expression levels in high and low lipid-producing strains of M. circinelloides to predict the possible roles of AMPK in lipid metabolism and to select candidate genes for further studies to enhance lipid accumulation. RESULTS: Two genes for α-subunit, one for ß-subunit and six for γ-subunit were identified and annotated. Bioinformatic analysis confirmed the presence of typical conserved domains in these genes. Furthermore, transcriptional profiling displayed marked differences in expression kinetics of subunits among the selected strains. The expression of AMPK genes decreased rapidly in WJ11, high lipid producer strain during the lipid accumulation phase while contrasting profile of expression was observed in CBS 277.49, low lipid producer strain. CONCLUSION: The present study has shown the association of AMPK genes with lipid metabolism at the transcriptional level. The involvement of Snf-α1, Snf-α2, Snf-ß, Snf-γ1, Snf-γ4, Snf-γ5 subunits were shown to be more pronounced and could potentially be further explored in future studies.

Risk Factors of Mid-upper Arm Circumference (MUAC) Based Child Malnutrition in the Flood-affected Areas of Pakistan: A Cross-sectional Study.

Low- and middle-income countries are usually at high risk of malnutrition. Not only that but the prevalence of malnutrition is much higher. It is important to evaluate the determinants of malnutrition in flood-affected areas of Pakistan. The present study examined the prevalence and risk factors of MUAC-based child malnutrition in flood-hit regions of Khyber Pakhtunkhwa, Pakistan. Multi-stage sampling was employed to select 656 households. Finally, 298 children of 6-59 months were selected. MUAC, an independent anthropometric parameter, was used to investigate the nutritional status of children. An automated logistic regression model was used to identify the risk factors of MUAC-based malnutrition. The prevalence of MUAC-based malnutrition was found 46%, including 40.5% females and 52.1% males. More than 90% of people had improved water quality and soap hand washing facility. Almost 17% of respondents had no toilet facility. Through automated logistic model, child age, maternal age, family size, income level, mother education, water quality, toilet facility were the significant determinants (P < .05) of MUAC-based undernutrition in flood affecting the area. The findings suggest that MUAC-based malnutrition can be minimized in flood-hit areas by targeting the listed risk factors. Community-based awareness programs regarding guidance on nutrition might be a key to reducing malnutrition in the target areas.

Fabrication of curcumin-loaded oleogels using camellia oil bodies and gum arabic/chitosan coatings for controlled release applications.

This study has explored the potential of plant-derived oil bodies (OBs)-based oleogels as novel drug delivery systems for in vitro release under simulated physiological conditions. To obtain stable OBs-based oleogels, gum arabic (GA) and chitosan (CH) were coated onto the curcumin-loaded OBs using an electrostatic deposition technique, followed by 2,3,4-trihydroxybenzaldehyde (TB) induced Schiff-base cross-linking. Microstructural analyses indicated successful encapsulation of curcumin into the hydrophobic domain of the OBs through a pH-driven method combined with ultrasound treatment. The curcumin encapsulation efficiency of OBs increased up to 83.65 % and 92.18 % when GA and GA-CH coatings were applied, respectively, compared to uncoated OBs (63.47 %). In addition, GA-CH coatings retained the structural integrity of oleogel droplets with superior oil-holding capacity (99.07 %), while TB addition induced interconnected 3D-network structures with excellent gel strength (≥4.8 × 105 Pa) and thermal stability (≥80 °C). GA-CH coated oleogels appeared to provide the best protection for loaded bioactive against UV irradiation and high temperature-induced degradation during long-term storage. The combination of biopolymer coatings and TB-induced Schiff-base cross-linking synergistically hindered the simulated gastric degradability of oleogels, releasing only 23.35 %, 12.46 % and 7.19 % of curcumin by GA, GA-CH and GA-CH-TB stabilized oleogels, respectively, while also resulting in sustained release effects during intestinal conditions.

Collagen and gelatin: Structure, properties, and applications in food industry.

Food-producing animals have the highest concentration of collagen in their extracellular matrix. Collagen and gelatin are widely used in food industry due to their specific structural, physicochemical, and biochemical properties, which enable them to improve health and nutritional value as well as to increase the stability, consistency, and elasticity of food products. This paper reviews the structural and functional properties including inherent self-assembly, gel forming, water-retaining, emulsifying, foaming, and thickening properties of collagen and gelatin. Then the colloid structures formed by collagen such as emulsions, films or coatings, and fibers are summarized. Finally, the potential applications of collagen and gelatin in muscle foods, dairy products, confectionary and dessert, and beverage products are also reviewed. The objective of this review is to provide the current market value, progress as well as applications of collagen and its derivatives in food industry.

Interfacial rheology of sodium caseinate/high acyl gellan gum complexes: Stabilizing oil-in-water emulsions.

In this work, the effects of pH and high acyl gellan gum concentration on the adsorption kinetics and interfacial dilatational rheology of sodium caseinate/high acyl gellan gum (CN/HG) complexes were investigated using a pendant drop tensiometer. In addition, stability related properties including interfacial protein concentration, droplet charge, size, microstructure and creaming index of emulsions were studied at different HG concentration (0-0.2 wt%) and pH values (4, 5.5 and 7). The results showed that HG adsorbed onto the CN mainly through electrostatic interactions which could lead to increase the interfacial pressure (π), rates of protein diffusion (kdiff), and molecular penetration (kp). The CN/HG complexes formed thick adsorption layers around the oil droplets which significantly increased the surface dilatational modulus with the increasing HG concentration. The CN/HG complexes appeared to form more elastic interfacial films after a long-term adsorption time compared with CN alone, which could reduce the droplet coalescence and thus prevented the growth of emulsion droplets. All four phosphorylated proteins of CN (αs1-, αs2-, ß-, and κ-casein) were adsorbed at the oil-water (O/W) interface as confirmed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), and surface protein coverage increased progressively with increasing HG concentration at pH 5.5, but decreased at pH 7. The CN/HG stabilized emulsions at pH 5.5 revealed the higher net charges and smaller z-average diameters than those at pH 4 and pH 7. This study provides valuable information on the use of CN/HG complexes to improve the stability and texture of food emulsions.

Glutaredoxin1 knockout promotes high-fat diet-induced obesity in male mice but not in female ones.

This study aims to explore how a high-fat diet and glutaredoxin1 (Glrx1) deficiency affect the development of obesity in male and female mice. A high-fat diet induced great differences in calorie intake and body weight gain between male and female mice; furthermore, the Glrx1 deficiency made male mice more sensitive to a high-fat diet than females. Male mice had higher glucose intolerance, and Glrx1 deficiency aggravated gender differences in glucose intolerance. Glrx1 deficiency aggravated high-fat diet-induced hyperlipidemia. The mRNA levels of HMGCR, Srebf-1c, Srebf-2, CD36, FASN and SCD1 were consistently lower in females than in males. Glrx1 deficiency exacerbated high-fat diet induced liver injury and oxidative stress. Diet but not gender or genotype altered the composition of gut microbiota. These findings provide a new insight into the different susceptibilities to obesity caused by a high-fat diet between males and females.

The Role of Meat Protein in Generation of Oxidative Stress and Pathophysiology of Metabolic Syndromes.

Various processing methods have a great impact on the physiochemical and nutritional properties of meat that are of health concern. Hence, the postmortem processing of meat by different methods is likely to intensify the potential effects on protein oxidation. The influence of meat protein oxidation on the modulation of the systemic redox status and underlying mechanism is well known. However, the effects of processed meat proteins isolated from different sources on gut microbiota, oxidative stress biomarkers, and metabolomic markers associated with metabolic syndromes are of growing interest. The application of advanced methodological approaches based on OMICS, and mass spectrometric technologies has enabled to better understand the molecular basis of the effect of processed meat oxidation on human health and the aging process. Animal studies indicate the involvement of dietary proteins isolated from different sources on health disorders, which emphasizes the impact of processed meat protein on the richness of bacterial taxa such as (Mucispirillum, Oscillibacter), accompanied by increased expression of lipogenic genes. This review explores the most recent evidences on meat processing techniques, meat protein oxidation, underlying mechanisms, and their potential effects on nutritional value, gut microbiota composition and possible implications on human health.

High-Fat Proteins Drive Dynamic Changes in Gut Microbiota, Hepatic Metabolome, and Endotoxemia-TLR-4-NFκB-Mediated Inflammation in Mice.

The responses of gut microbiota to dietary proteins have been studied previously. However, the effects of dietary proteins supplemented with a high-fat diet (HFD) on the metabolite biomarkers associated with non-alcoholic fatty liver disease (NAFLD) are not well understood. To understand the underlying mechanisms, C57BL/6J mice were fed with either a low-fat diet with casein (LFC) or an HFD with casein (HFC), fish (HFF), or mutton proteins (HFM), and their cecal microbiota and liver metabolites were analyzed. At the phylum level, the HFD group had a relatively higher abundance of Firmicutes compared to the LFC-diet group. At the genus level, the HFF-diet group had the highest abundance of Lactobacillus and Akkermansia compared to the HFC- and HFM-diet groups. Furthermore, mice fed with the HFF diet had significantly reduced levels of hepatic metabolites involved in oxidative stress and bile acid metabolism. Thus, meat proteins in HFD interact in the host to create distinct responses in the gut microbiota and its metabolites.

Meat Protein in High-Fat Diet Induces Adipogensis and Dyslipidemia by Altering Gut Microbiota and Endocannabinoid Dysregulation in the Adipose Tissue of Mice.

Endocannabinoids modulate insulin and adipokine expression in adipocytes through cannabinoid receptors and their levels are elevated during hyperglycemia and obesity, but little is known about how diets affect them. We assessed the effects of dietary casein, chicken, beef, and pork proteins in a high-fat diet mode, on endocannabinoids, adipogenesis, and biomarkers associated with dyslipemdia. A high-fat beef or chicken diet upregulated cannabinoid 1 receptor, N-acyl phosphatidylethanolamine-selective phospholipase-D and diacylglycerol lipase α in adipose tissue and reduced the immunoreactivity of mitochondrial uncoupling protein 1 in brown adipose tissue. In addition, the high-fat diets with beef and chicken protein had a significant impact on adipocyte differentiation and mitochondrial biogenesis in obese mice. A 16S rRNA gene sequencing indicated that high-fat diets, regardless of the protein source, significantly enhanced the ratio of Firmicutes to Bacteroidetes in colon. Meat proteins in a high-fat diet significantly decreased the relative abundances of Akkermansia and Bifidobacteria but enhanced the lipopolysaccharides level in the serum, which promoted the adipogenesis process by causing dysregulation in the endocannabinoid receptors. Consumption of meat protein with high-fat-induced adiposity, visceral obesity, and dyslipidemia reduced the thermogenesis and had a distinctive effect on the mitochondrial biogenesis compared with casein protein.

Gut inflammation exacerbates hepatic injury in C57BL/6J mice via gut-vascular barrier dysfunction with high-fat-incorporated meat protein diets.

AIM: Meat and its derivatives provide nutrients essential for human health. However, meat consumption, along with excessive fat intake, has been associated with gut inflammation, intestinal barrier dysfunction and alterations in gut microbiota. Herein, we investigated whether and how these changes in the intestinal barrier system affect the gut liver axis and hepatic injury and eventually lead to the progression of liver syndrome such as NAFLD. METHODS: Mice were fed with high fat (60% kcal) or low fat (12% kcal) along with soybean (control), chicken and pork proteins (HFCH, HFP, LFCH, and LFP) for 12 weeks. The biomarkers for liver injury were investigated after meat protein intake along with the high fat. FINDINGS: Greater amount of fat vacuoles visible in the H&E staining increased the inflammatory cell infiltration and disorganized liver structures were observed in the HFP-fed mice. Oil Red O staining revealed that the HFP-fed and HFCH-fed mice showed more lipid droplets, confirming the increased hepatic lipid accumulation. Potential serum markers for NAFLD, ALT and AST were increased in the HF meat diet groups. Key genes responsible for hepatic inflammation and lipogenesis, such as MCP-1, IL1-ß and TNF-α were upregulated. HF meat protein diet-fed mice exhibited signs of compromised liver with increased levels of endotoxin in the liver and its binding protein in serum, upregulation of TLRs in the liver, and significant increase in TG, TC, LDL-C and HDL-C concentrations. SIGNIFICANCE: Intestinal inflammation and barrier dysfunction aggravate liver injury and fibrosis due to the intake of HF meat protein diets in mice, which may contribute to the progress of liver injury and associated complications. Gut inflammation may directly contribute to the development of NAFLD, especially of the gut vascular barricade dysfunction.

High fat diet incorporated with meat proteins changes biomarkers of lipid metabolism, antioxidant activities, and the serum metabolomic profile in Glrx1-/- mice.

Red and processed meat consumption has been associated with oxidative stress, diabetes and non-alcoholic fatty liver disease (NAFLD). This study was aimed at exploring the effects of high-fat meat protein diets on potential metabolite biomarkers in Glrx1-/- mice, a well-documented mouse model to study NAFLD. Male Glrx1-/- mice were fed a control diet with 12% energy (kcal) from fat, a high-fat diet supplemented with casein (HFC) with 60% energy (kcal) from fat, and a high-fat diet supplemented with fish (HFF) or mutton proteins (HFM) for 12 weeks. The results of biochemical and histological analyses indicated that the intake of HFM increased hepatic total cholesterol, triglycerides, serum alanine transaminase and aspartate transaminase, and macro- and micro-vesicular lipid droplet accumulation, which were accompanied by altered gene expression associated with the lipid and cholesterol metabolism. HFF diet fed Glrx1-/- mice significantly ameliorated diet-induced NAFLD biomarkers compared to HFC and HFM diets. In addition, serum metabolome profiling identified metabolites specifically associated with lipid metabolism bile acid metabolism, sphingolipid and amino acid metabolism pathways. A HFM diet increased the abundance of LysoPC(15:0), LysoPC(16:0), LysoPC(20:1), LysoPE(18:2), LysoPE(22:0), LysoPE(20:6), O-arachidonoylglycidol, 12-ketodeoxycholic acid and sphinganine that are associated with NAFLD. The KEGG metabolic pathway of identified metabolites of high fat diets showed that the differential metabolites were associated with lipid metabolism, linoleic acid metabolism, amino acid metabolism, bile acid metabolism, sphingolipid metabolism, and glutathione metabolism pathways whereas HFF diet ameliorated NAFLD by modifying these pathways. These results provide potential metabolite biomarkers for NAFLD induced by HFM diet.

Processed Meat Protein Promoted Inflammation and Hepatic Lipogenesis by Upregulating Nrf2/Keap1 Signaling Pathway in Glrx-Deficient Mice.

Oxidative stress may play a critical role in the progression of liver disorders. Increasing interest has been given to the associations among diet, oxidative stress, gut-liver axis, and nonalcoholic fatty liver disease. Here, we investigated the effects of processed meat proteins on biomarkers of lipid homeostasis, hepatic metabolism, antioxidant functions, and gut microbiota composition in glutaredoxin1 deficient (Glrx1-/-) mice. The wild-type (WT) and Glrx1-/- mice were fed a soy protein diet (SPD), a dry-cured pork protein diet (DPD), a braised pork protein diet (BPD), and a cooked pork protein diet (CPD) at a dose of 20% of protein for 3 months. Serum and hepatic total cholesterol, serum endotoxin, hepatic liver droplet %, and antioxidant capacity were significantly increased in the CPD fed WT mice. In addition, CPD fed Glrx1-/- mice significantly increased total cholesterol, triacylglycerol, and pro-inflammatory cytokines which are accompanied by higher steatosis scores, intrahepatic lipid accumulation, and altered gene expression associated with lipid metabolism. Furthermore, hepatic gene expression of Nrf2/keap1 signaling pathway and its downstream signaling targets were determined using RT-qPCR. Glrx1 deficiency increased Nrf2 activity and expression of its target genes (GPx, catalase, SOD1, G6pd, and Bbc3), which was exacerbated by intake of CPD. Metagenomic analyses revealed that Glrx1-/- mice fed meat protein diets had higher abundances of Mucispirillum, Oscillibacter, and Mollicutes but lower abundances of Bacteroidales S24-7 group_norank, Blautia, and Anaerotruncus than their wild-type counterparts. In summary, Glrx1 deficiency induced an increase in serum biomarkers for lipid homeostasis, gut microbiota imbalance, and upregulation of Nrf2/Keap1 and antioxidant defense genes, which was aggravated by cooked meat protein diet.

Meat proteins in a high-fat diet have a substantial impact on intestinal barriers through mucus layer and tight junction protein suppression in C57BL/6J mice.

Protein diets are well known for body maintenance and weight loss. However, it remains unclear whether and how different protein sources affect the intestinal epithelial integrity through tight junctions, mucus secretions and host immunity in diet-induced obesity. To evaluate possible effects, soybean, chicken and pork proteins either with low fat (12% kcal) or high fat (60% kcal) were administered to C57BL/6J mice for 12 weeks. Muc2 expression, tight junction proteins, goblet cells, and inflammatory cytokines in the colon and serum were measured. The intake of a high-fat pork protein diet decreased the number of goblet cells and inhibited Muc2 expression in the colon, which impaired the mucus barrier. Immunohistochemistry indicated decreased crypt depth and downregulation of tight junction proteins in high-fat diet fed mice, signifying losses of epithelial barriers. In addition, a pork protein diet reduces the key zonula occludens-1 and E-cadherin proteins. A high-fat meat protein diet induces colonic inflammatory injury by upregulating several key cytokines and increasing IL-1ß, TNF-α, IL-6 and IFN-γ concentrations in serum. The intake of high-fat meat protein diets resulted in the impairment of the colon barrier through mucus suppression, downregulation of tight junctions, and gut inflammation in mice.

Occurrence of Heterocyclic Amines in Commercial Fast-Food Meat Products Available on the Chinese Market and Assessment of Human Exposure to these Compounds.

Heterocyclic amines (HCAs) have been identified as highly mutagenic and are risk factors for human cancer. In recent years, the intake of fast-food meat products has increased exponentially due to their convenience. Therefore, it is important to assess the health risks of HCAs and provide useful public dietary guidelines. Eight fast-food meat products were selected from the Chinese market, including chicken, beef, and fish, to evaluate their health risk in conjunction with HCAs. Crispy chicken drumsticks contained the maximum level of total HCAs (24.18 ± 3.57 ng/g), followed by crispy fried chicken burgers (19.99 ± 1.41 ng/g) and traditional Chinese nuggets (19.17 ± 1.23 ng/g), whereas shrimp cake burgers had the lowest levels (13.17 ± 1.77 ng/g). Crispy chicken drumsticks (men: 169.12 ng/day, women: 108.70 ng/day), hot chicken wings (men: 126.32 ng/day, women: 142.11 ng/day), and crispy fried chicken burgers (men: 129.78 ng/day, women: 59.91 ng/day) were found to provide the highest dietary intake of HCAs in both genders, which may lead to an increase in colorectal and breast cancers. PRACTICAL APPLICATIONS: The rapid expansion of the Chinese fast-food industry has promoted serious health problems, such as colorectal cancer and some cardiovascular diseases. Several epidemiological studies revealed that a high intake of processed meats may increase the risk of cancer in humans because cooking food proteins, such as meat, at high temperatures could produce high levels of carcinogenic compounds, such as HCAs. Because of the vast variation in eating habits, preparation methods and the frequency of meat consumption, it is important to evaluate the accurate level of HCAs in commercially available fast-food meat products with the aim to clarify the association between processed meats and the health risk.