Lipid metabolism and m6A RNA methylation are altered in lambs supplemented rumen-protected methionine and lysine in a low-protein diet.

BACKGROUND: Methionine or lysine has been reported to influence DNA methylation and fat metabolism, but their combined effects in N6-methyl-adenosine (m6A) RNA methylation remain unclarified. The combined effects of rumen-protected methionine and lysine (RML) in a low-protein (LP) diet on lipid metabolism, m6A RNA methylation, and fatty acid (FA) profiles in the liver and muscle of lambs were investigated. Sixty-three male lambs were divided into three treatment groups, three pens per group and seven lambs per pen. The lambs were fed a 14.5% crude protein (CP) diet (adequate protein [NP]), 12.5% CP diet (LP), and a LP diet plus RML (LP + RML) for 60 d. RESULTS: The results showed that the addition of RML in a LP diet tended to lower the concentrations of plasma leptin (P = 0.07), triglyceride (P = 0.05), and non-esterified FA (P = 0.08). Feeding a LP diet increased the enzyme activity or mRNA expression of lipogenic enzymes and decreased lipolytic enzymes compared with the NP diet. This effect was reversed by supplementation of RML with a LP diet. The inclusion of RML in a LP diet affected the polyunsaturated fatty acids (PUFA), n-3 PUFA, and n-6 PUFA in the liver but not in the muscle, which might be linked with altered expression of FA desaturase-1 (FADS1) and acetyl-CoA carboxylase (ACC). A LP diet supplemented with RML increased (P < 0.05) total m6A levels in the liver and muscle and were accompanied by decreased expression of fat mass and obesity-associated protein (FTO) and alkB homologue 5 (ALKBH5). The mRNA expressions of methyltransferase-like 3 (METTL3) and methyltransferase-like 14 (METTL14) in the LP + RML diet group were lower than those in the other two groups. Supplementation of RML with a LP diet affected only liver YTH domain family (YTHDF2) proteins (P < 0.05) and muscle YTHDF3 (P = 0.09), which can be explained by limited m6A-binding proteins that were mediated in mRNA fate. CONCLUSIONS: Our findings showed that the inclusion of RML in a LP diet could alter fat deposition through modulations of lipogenesis and lipolysis in the liver and muscle. These changes in fat metabolism may be associated with the modification of m6A RNA methylation. A systematic graph illustrates the mechanism of dietary methionine and lysine influence on lipid metabolism and M6A. The green arrow with triangular heads indicates as activation and brown-wine arrows with flat heads indicates as suppression.

Effects of the natural sweetener rebaudioside A on intake, nutrient digestion, rumen fermentation, and blood biochemical parameters in adult goats during summer.

The effects of dietary rebaudioside A inclusion on feed intake, digestion of nutrients, rumen fermentation, and blood biochemical parameters of goats were evaluated in a replicated 3 × 3 Latin square study. Nine adult goats during summer were fed a basal forage/concentrate-based diet and the forage was chopped rice straw. The three dietary treatments were 0, 350, and 700 mg rebaudioside A per kg chopped rice straw on a DM basis. No significant improvement was observed in dry matter intake (DMI) of forage and diet among treatments. Nutrient digestibility of DM and organic matter (OM) showed a significant trend (p < .10) across groups. Rebaudioside A inclusion significantly (p < .01) increased the concentration of total volatile fatty acids in the rumen, however, there were no differences in concentration of ruminal ammonia, and molar proportions of acetate, propionate, and butyrate. About blood metabolites, increasing rebaudioside A in the diet caused a quadratic response in glucose and total protein, and albumin concentrations. Under the conditions of this study, supplementation with rebaudioside A at 350 and 700 mg/kg forage did not improve consumption of rice straw-based diet in adult goats in summer. However, the responses in digestibility, rumen fermentation, and blood metabolites appear to indicate the potential of rebaudioside A as a bio-active substance in goats.

Effects of Dietary Zinc-Methionine Supplementation During Pregnancy on the Whole-Genome Methylation and Related Gene Expression in the Liver and Spleen of Growing Goats: a Short Communication.

The effect of replacing inorganic zinc with organic zinc in diets of pregnant goats was investigated on the development of the liver and spleen of offspring. Pregnant goats (n = 14; Xiangdong black goat, local breed) of similar parity and body weight (BW, 37.17 ± 5.28 kg) were selected and divided randomly into two groups: the zinc sulfate group (ZnSO4; n = 7) and the methionine-chelated zinc group (Zn-Met; n = 7). Goats were fed for 45 days (day 106 of gestation to delivery). After delivering, lactating goats were fed a diet without extra zinc supplement. Kid goats were weaned at 2 months of age and both the groups were fed the same diet. All goats were fed a mixed diet and had free access to fresh water. Kid goats were slaughtered on day 100, and the liver and spleen were collected, weighed, and stored in liquid nitrogen for genomic DNA methylation and related gene expression determination. In the Zn-Met group, the liver organ index of kid goats showed an increasing trend (P < 0.10), but the methylation of the whole genome was not affected both in the liver and spleen (P > 0.10). Furthermore, the blood zinc content of the offspring was reduced (P < 0.05), and the expression of genes related to methylation were downregulated (P < 0.05) or showed a downward trend (P < 0.10) in the liver and spleen. These data indicated that goats feeding Zn-Met during pregnancy increased the offspring liver organ index without change in the genomic DNA methylation. It is speculated that the regulation of zinc finger protein Sp3 adjusted by blood zinc indirectly regulated the expression of methylation-related genes in the liver and spleen of the kid goats, thus enhancing the development and function of the immune system of the offspring.

Magnolol and Honokiol Attenuate Apoptosis of Enterotoxigenic Escherichia Coli-Induced Intestinal Epithelium by Maintaining Secretion and Absorption Homeostasis and Protecting Mucosal Integrity.

BACKGROUND The cortex of Magnolia officinalis has long been used as an element of traditional Chinese medicine for the treatment of anxiety, chronic bronchitis, and gastrointestinal dysfunction. This study aimed to elucidate the underlying mechanism of its functional ingredients (magnolol and honokiol) in modifying the secretion and absorption homeostasis and protecting mucosal integrity in an Enterotoxigenic Escherichia coli (ETEC)-induced diarrhea mouse model. MATERIAL AND METHODS This study established a diarrhea mouse model infected by ETEC at a dosage of 0.02 ml/g live body weight (BW) in vivo. Magnolol or honokiol was followed by an intraperitoneal administration at dosages of 100, 300, and 500 mg/kg BW according to a 3×3 factorial arrangement. The useful biomarkers for evaluating the integrity of intestinal tract and histologic injury were analyzed and morphological development (including villus height, crypt depth, and ratio of villus height to crypt depth) and the expressions of inflammatory cytokines were determined by real-time PCR. RESULTS The results showed that magnolol and honokiol (500 mg/kg BW) reduced the concentrations of NO, DAO, and DLA, and iNOS activity, and the mRNA expressions of the interferon gamma (IFN-γ) and interleukin 10 (IL-10), and inhibited intestinal epithelial cell apoptosis. Magnolol and honokiol (300 mg/kg BW) elongated the villus height and crypt depth and decreased the number of goblet cells and the ratio of villus height to crypt depth. CONCLUSIONS The current results indicate that magnolol and honokiol enhance the intestinal anti-inflammatory capacities, elongate the villus height and crypt depth, and reduce goblet cell numbers to inhibit the intestinal epithelium apoptosis and effectively protect the intestinal mucosa. These results show that magnolol and honokiol protect the intestinal mucosal integrity and regulate gastrointestinal dysfunction.

Influence of Oleic Acid on Rumen Fermentation and Fatty Acid Formation In Vitro.

A series of batch cultures were conducted to investigate the effects of oleic acid (OA) on in vitro ruminal dry matter degradability (IVDMD), gas production, methane (CH4) and hydrogen (H2) production, and proportion of fatty acids. Rumen fluid was collected from fistulated goats, diluted with incubation buffer, and then incubated with 500 mg Leymus chinensis meal supplemented with different amounts of OA (0, 20, 40, and 60 mg for the CON, OA20, OA40 and OA60 groups, respectively). Incubation was carried out anaerobically at 39°C for 48 h, and the samples were taken at 12, 24 and 48 h and subjected to laboratory analysis. Supplementation of OA decreased IVDMD, the cumulative gas production, theoretical maximum of gas production and CH4 production, but increased H2 production. However, no effect was observed on any parameters of rumen fermentation (pH, ammonia, production of acetate, propionate and butyrate and total volatile fatty acid production). The concentrations of some beneficial fatty acids, such as cis monounsaturated fatty acids and conjugated linoleic acid (CLA) were higher (P < 0.05) from OA groups than those from the control group at 12 h incubation. In summary, these results suggest that the OA supplementation in diet can reduce methane production and increase the amount of some beneficial fatty acids in vitro.

Effects of dietary addition of cellulase and a Saccharomyces cerevisiae fermentation product on nutrient digestibility, rumen fermentation and enteric methane emissions in growing goats.

This study was designed to assess the effectiveness of dietary cellulase (243 U/g, derived from Neocallimastix patriciarum) and a Saccharomyces cerevisiae fermentation product (yeast product) on ruminal fermentation characteristics, enteric methane (CH4) emissions and methanogenic community in growing goats. The experiment was conducted in a 5 × 5 Latin square design using five Xiangdong black wether goats. The treatments included a Control and two levels of cellulase (0.8 g and 1.6 g/kg dry matter intake (DMI), i.e. 194 U/kg and 389 U/kg DMI, respectively) crossed over with two levels (6 g or 12 g/kg DMI) of the yeast product. There were no significant differences regarding feed intake, apparent digestibility of organic matter, neutral detergent fibre and acid detergent fibre among all the treatments. In comparison with the Control, the ruminal ammonia N concentration was decreased (p = 0.001) by cellulase and yeast product addition. The activities of carboxymethylcellulase and xylanase were decreased after cellulase addition. Moreover, dietary cellulase and yeast product addition led to a significant reduction (p < 0.05) of enteric CH4 emissions although the diversity and copy numbers of methanogens among treatments were not dissimilar. The present results indicate that the combination of cellulase and yeast fermentation product can reduce the production of CH4 energy and mitigate the enteric CH4 emissions to a certain degree.

Effect of tea catechins on regulation of antioxidant enzyme expression in H2O2-induced skeletal muscle cells of goat in vitro.

Skeletal muscle cells (SMCs) of goats were stress induced with 1 mM H(2)O(2) in the absence or presence of 0.5, 5, and 50 µg/mL tea catechins (TCs) incubation. Cells were harvested at 48 h postincubation with TCs to investigate the effects of TCs on cell proliferation, cell membrane integrity, antioxidant enzyme activities, and antioxidant enzyme genes and protein expression levels. Results showed that H(2)O(2) induction inhibited cell proliferation with or without TC incubation; moreover, the inhibition effect was enhanced in the presence of TCs (P < 0.001). H(2)O(2)-induced stress increased the lactate dehydrogenase (LDH) activity in the absence or presence of TC incubation, but concentrations of TCs, less than 5 µg/mL, showed protective functions against LDH leakage than in other H(2)O(2)-induced treatments. The catalase (CAT) activity increased when SMCs were stress induced with H(2)O(2) in the absence or presence of TC incubation (P < 0.001). H(2)O(2)-induced stress decreased CuZn superoxide dismutase (CuZn-SOD) and glutathione peroxidase (GPx) activities, whereas this effect was prevented by incubation with TCs in a concentration-dependent manner. H(2)O(2)-induced stress with or without TC incubation had significant effects on mRNA and protein expression levels of CAT, CuZn-SOD, and GPx (P < 0.001). CAT and CuZn-SOD mRNA expression levels were increased by different concentrations of TC incubation, and this tendency was basically consistent with corresponding protein expression levels. The GPx mRNA expression level increased with a low concentration of TCs but decreased with concentrations greater than 5 µg/mL of TCs, whereas GPx protein expression in all TC-incubated groups was lower than in the control treatment. The current findings imply that TCs had an inhibitory effect on cell proliferation and enhanced damage to the cell membrane integrity, but TCs affected antioxidant status in SMCs by modulating antioxidant enzyme activities at mRNA and protein expression levels.

Effects of alkyl polyglycoside, a nonionic surfactant, and forage-to-concentrate ratio on rumen fermentation, amino acid composition of rumen content, bacteria and plasma in goats.

In the present study, the effects of different forage-to-concentrate ratios (F:C) and an alkyl polyglycoside (APG) supplementation on parameters of rumen and blood metabolism were investigated in goats. A 2 x 2 factorial experiment was arranged within a 4 x 4 Latin square design (four 22-day periods), using four wether goats equipped with permanent ruminal cannulas. The experimental diets included two F:C levels (40:60 vs. 60:40), and two APG supplementation levels (None or 13 ml APG daily per animal). Rumen contents and blood samples were collected at the end of each period. Dietary F:C alteration affected plasma urea and influenced the proportions of leucine, histidine, arginine, glycine, proline, alanine, valine, phenylalanine, cysteine and tyrosine in rumen content, and the proportions of methionine, threonine and proline in solid-associated bacteria (SAB) significantly. Dietary APG decreased the proportions of valine and phenylalanine in rumen content, and the histidine content of liquid-associated bacteria. The interaction between dietary F:C and APG was significant for the proportions of glycine and alanine in rumen content, and the proportions of lysine and threonine in SAB. The proportion of lysine was greater, but the proportion of threonine was less in SAB for goats fed high F:C diet without APG supplementation. The proportions of plasma free amino acids and glucose concentration were not affected by experimental treatments. These results indicated that dietary APG addition affected the amino acid composition of the rumen content and ruminal bacteria, but this depended on the dietary F:C ratio. It is necessary to validate the effectiveness of dietary APG supplementation in further studies with more animals.