Dong Niu

Analysis of miRNAs and their target genes associated with lipid metabolism in duck liver.

Fat character is an important index in duck culture that linked to local flavor, feed cost and fat intake for costumers. Since the regulation networks in duck lipid metabolism had not been reported very clearly, we aimed to explore the potential miRNA-mRNA pairs and their regulatory roles in duck lipid metabolism. Here, Cherry-Valley ducks were selected and treated with/without 5% oil added in feed for 2 weeks, and then fat content determination was performed on. The data showed that the fat contents and the fatty acid ratios of C17:1 and C18:2 were up-regulated in livers of oil-added ducks, while the C12:0 ratio was down-regulated. Then 21 differential miRNAs, including 10 novel miRNAs, were obtain from the livers by sequencing, and 73 target genes involved in lipid metabolic processes of these miRNAs were found, which constituted 316 miRNA-mRNA pairs. Two miRNA-mRNA pairs including one novel miRNA and one known miRNA, N-miR-16020-FASN and gga-miR-144-ELOVL6, were selected to validate the miRNA-mRNA negative relation. And the results showed that N-mir-16020 and gga-miR-144 could respectively bind the 3′-UTRs of FASN and ELOVL6 to control their expressions. This study provides new sights and useful information for future research on regulation network in duck lipid metabolism.

Expression pattern of adipocyte fatty acid-binding protein gene in different tissues and its regulation of genes related to adipocyte differentiation in duck

Abundance of duck adipocyte fatty acid-binding protein (A-FABP) mRNA was detected in this study by quantitative real-time PCR. The results showed that duck A-FABP gene was expressed in muscular tissues and many organs, except pancreas, lung, and kidney, and highly expressed in adipose tissues, especially in sebum. The expression of A-FABP and adipocyte differentiation-related genes was upregulated by oleic acid, and the A-FABP knockdown suppressed the oleic acid-stimulated expression of these genes in the cultured duck adipocytes, indicating A-FABP might play an important role in duck adipocyte differentiation.

Effects of perilla extract on productive performance, serum values and hepatic expression of lipid-related genes in Shaoxing ducks

1. The aim of this study was to identify the effect of perilla extract, a source of polyunsaturated fatty acids, on lipid metabolism and expression of lipid-related genes in livers of Shaoxing ducks. 2. Two hundred and forty 28-week-old laying ducks received a commercial diet with perilla extract added at 0 (control) or 200 mg/kg of feed. 3. Ducks fed on a diet with perilla extract had increased laying rates compared with control ducks. 4. Serum concentrations of triglycerides were reduced by perilla extract, while high-density lipoprotein cholesterol and total serum cholesterol increased. 5. The expression of genes involved in hepatic lipogenesis, sterol regulatory element-binding protein-1, acetyl CoA carboxylase, stearoyl CoA desaturase, fatty acid synthase, apolipoprotein B, and apolipoprotein very low density lipoprotein, were decreased in the perilla group. 6. The mRNA expression of peroxisome proliferators-activated receptor alpha and acyl-coenzyme A oxidase was enhanced following treatment with perilla extract, and a similar tendency was observed in the expression of liver fatty acid-binding protein. 7. The results show that a diet with 200 mg/kg perilla extract regulated fat metabolism of Shaoxing ducks by improving egg laying, altering serum lipid profiles, stimulating lipid catabolic gene expression and inibiting lipogenic gene expression in the liver.

MiR-144 affects fatty acid composition by regulating ELOVL6 expression in duck hepatocytes†

Lipid metabolism in duck is very important for both raisers and peoples health. In our previous studies, we have detected that miR‐144 is related to duck lipid metabolism and validated one of its target genes, elongation of very long chain fatty acids protein 6 (ELOVL6). In the present study, we isolated, cultured, and identified duck hepatocytes, and transfected with miR‐144 mimics/inhibitor to mediate the miR‐144 level. The qRT‐PCR results showed that the ELOVL6 expression in duck hepatocytes was down/upregulated, respectively. The fat contents and each fatty‐acid percent content of the hepatocytes and medium were also determined. When ELOVL6 expression suppressed (miR‐144 mimics transfected), the palmitic acid (C16:0) content was significantly increased (P < 0.05); the oleic acid (C18:1, n‐9), eicosenoic acid (C20:1, n‐9), and eicosatrienoic acid (C20:3) contents were significantly reduced (P < 0.05). The myristic acid (C14:0) and palmitic acid (C16:0) contents were significantly reduced (P < 0.05), and the oleic acid (C18:1, n‐9) content was significantly increased (P < 0.05) when ELOVL6 expression upregulated (miR‐144 inhibitor transfected). It indicated that miR‐144 could regulate some saturated fatty acids elongated to longer unsaturated fatty acids through controlling ELOVL6 expression. Whereas, miR‐144/ELOVL6 appeared not associated with fat deposition in duck hepatocytes (P > 0.05). Our findings suggest that miR‐144 might regulate the percentages of fatty acids in duck hepatocytes through affecting ELOVL6 expression.

Effects of dietary fats on egg quality and lipid parameters in serum and yolks of Shan Partridge Duck

&NA; The effects of different dietary fats with variable levels of polyunsaturated fatty acids (PUFAs) on egg quality of Shan Partridge Duck, serum, and yolk lipid parameters were examined in this study. A flock of 585 optimal produced ducks were selected and diets enriched with 0.5%, 1%, or 2% fish oil (F)/flaxseed oil (FL)/rapeseed oil (R)/tallow (T) plus basal diet were supplied through a 28‐d period. Supplemental fat source and fat level had no effects on egg qualities. Proportions of yolk total cholesterol (TC), saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs) were reduced (P < 0.001), while polyunsaturated fatty acids (PUFAs), &ohgr;‐6 polyunsaturated fatty acids (n‐6 PUFAs), &ohgr;‐3 polyunsaturated fatty acids (n‐3 PUFAs), Docosahexaenoic Acid (DHA), and Eicosapentaenoic Acid (EPA) were increased by fish oil, flaxseed oil, or rapeseed oil. Effects of supplementation increasing DHA and EPA were detected in F, FL, and R. Compared with C, fish oil significantly increased low‐density lipoprotein cholesterol (LDL‐C) in serum, flaxseed oil significantly reduced TC and increased very low‐density lipoprotein cholesterol (VLDL‐C), rapeseed oil significantly reduced TC and LDL‐C in serum and increased VLDL‐C, tallow significantly increased LDL‐C. It is concluded that unsaturated fatty acids rich diets (fish oil, flaxseed oil, and rapeseed oil) might increase yolk PUFAs, reduce yolk cholesterol, and change serum lipid parameters without evident effect on egg qualities.

Digital gene-expression profiling analysis of the fatty liver of Landes geese fed different supplemental oils

The goose liver is an ideal model for deciphering lipogenesis molecular mechanisms. This study was designed to investigate the effect of different lipid sources on hepatic lipogenesis in overfed geese. Sixty Landes geese were fed ad libitum with no fat (control) or overfed diets containing 2% goose fat (GF) or rapeseed oil (RO) for 20 days. We measured fatty acid composition of the liver at day 20 of overfeeding. We performed a transcriptomic comparison of fatty liver between GF and RO-fed geese to gain insights into the molecular and cellular events mediating lipogenesis activity. The results showed that there was no substantial effect on fatty liver performance between GF- and RO-fed geese. Significant differences in fatty acid composition were detected between GF- and RO-fed geese. Total ω-6 PUFAs increased and saturated fatty acid decreased (P < 0.05) with RO supplementation when compared with GF, but ω-3 PUFAs did not differ between the two diets. Concentrations of C16:1, C18:1, C18:2, C20:2, and C22:1 were higher (P < 0.05) in the fatty liver of RO-fed geese compared to those in the GF group. Analysis of transcriptome sequencing showed that there were 124 up-regulated and 129 down-regulated differentially expressed genes in the fatty liver of RO and GF-fed geese. Many of these genes code for proteins involved in the lipid metabolic process, including bile secretion, adipocytokine signalling pathway, biosynthesis of unsaturated fatty acids, linoleic acid metabolism, fatty acid elongation and fatty acid biosynthesis, and fat digestion and absorption. Moreover, genes involved in lipid-related pathways such as peroxisome, steroid biosynthesis, steroid hormone biosynthesis, retinol metabolism, and apoptosis were altered, suggesting that the fatty liver of goose fed different oils undertakes both an oxidation function and hormone-related metabolic function. In conclusions, these data suggest that RO supplementation reduces liver lipid oxidation and improves lipogenesis. These findings provide new insights into the molecular mechanisms involved in fatty liver formation and provide valuable resources for analysing mechanisms underlying the effects of oils from different sources on the goose fatty liver.

The Effect of Hydrated Sodium Calcium Aluminosilicate on Fatty Liver and the Composition of the Intestinal Microbiota in Overfed Landes Geese

Goose fatty liver is a delicious food product and the overfeeding will cause the abnormal physiology of the geese. The objective of this study was to investigate the effect of supplementation with hydrated sodium calcium aluminosilicate (HSCAS) on the fatty liver, ileal and cecal microbiota of Landes geese during overfeeding. Sixty 70-day-old Landes geese (body weight= 3.0 ± 0.05 kg) were randomly divided into three groups, two of which were overfed with whole corn supplemented with or without HSCAS for 20 days when the fatty liver reaches to the maximum size and the negative control group was ad libitum access to the corn basal diet. The intestinal contents of the ileum and cecum from three geese per group were used for high-throughput sequencing. As a result of this study, the HSCAS-treatment led to an increase in relative liver weight (p<0.05) of geese compared with the overfeeding control group. The richness and diversity of the bacterial communities decreased in the ileum and ceca after overfeeding. Overfeeding increased the relative abundance of Firmicutes, especially Lactobacillus, in ileal samples. HSCAS supplementation increased the relative abundance of Lactobacillus, and decreased the relative abundance of Actinobacillus in the ileum and the relative abundance of Erysipelotrichi, Bacteroides and Escherichia in the ceca. Bacterial richness indicators were also increased in samples from ileum and ceca after HSCAS supplementation. In conclusion, dietary HSCAS supplementation promoted liver performance in overfed Landes geese. HSCAS treatment had a beneficial effect on the intestinal microbiota composition in geese during the overfeeding.

Effects of hydrated sodium calcium aluminosilicate on growth performance, fatty liver, intestine morphology, and serum parameters of overfed geese

In geese, overfeeding induces hepatic steatosis and makes the liver functions enhanced. Aluminosilicate absorbs toxins created by moulds in animal feeds and enhances nutrient absorption. In the present study, the effects of hydrated sodium calcium aluminosilicate (Improved HSCAS, Jumpstar) on the growth performance, fatty liver, serum parameters, and intestinal morphology of overfed Landes geese were evaluated. The study included two Control groups, a non-overfed Control (Control I) and an overfed Control (Control II), as well as a treatment group. The results showed that compared with the Control I group, liver weight, relative liver weight, abdominal fat weight, intestinal fat weight, villus height, total cholesterol, very low density lipoproteins, lipoprotein lipase, aspartate aminotransferase, IgM, and IgG in the HSCAS treatment group all significantly increased (P 0.05), and decreased aspartate aminotransferase levels than those in the Control II group (P < 0.05). In conclusion, HSCAS treatment had a beneficial effect on fatty liver production, intestinal development, and serum parameters in overfed Landes geese, which could enhance the health status of these geese.

Construction, Expression and Characterization of a Single Chain Variable Fragment Antibody Against Human Myostatin

Myostatin plays negative roles in muscle development. To block the inhibitory effects of myostatin on myogenesis, a 759 bp single chain variable fragment antibody (scFv) against myostatin was constructed and expressed in Escherichia coli. ELISA detection showed that the scFv could bind to myostatin, and change of the scFv N-terminal peptides decreased its binding affinity. MTT assay and cell morphology demonstrated that the cell number and viability of the C2C12 myoblast were enhanced by the scFv. Meanwhile, the scFv significantly inhibited the myostatin-induced expression of cyclin-dependent kinase inhibitor p21 and Smad binding element-luciferase activity. H2O2 increased the expression of Muscle RING Finger 1 (MuRF1) and Muscle Atrophy F-box (MAFbx) in myoblasts as well as myostatin and MuRF1 in myotubes, and the scFv significantly decreased the H2O2-elevated expression of these genes. Conclusively, the scFv we developed could antagonize the inhibitory effects of myostatin on myogenesis through Smad pathway and regulation of p21, MuRF1 and MAFbx gene expression. The scFv may have application in the therapy of muscular dystrophy and improvement of animal meat production.