Research Note: Transcriptome analysis reveals differentially expressed genes regulated muscle development in Pekin ducks during dietary threonine deficiency.

To investigate the underlying molecular mechanism of threonine (Thr) regulation on the development of breast muscle in Pekin ducks, 240 male Pekin ducks at 1 d of age were fed a Thr deficiency diet (Thr-D), Thr sufficiency diet (Thr-S), or Thr excess diet (Thr-E) for 21 d. The results showed that Thr-D reduced body weight (BW), average weight gain (ADG), and average feed intake (ADFI), and increased the feed/gain (F/G) in Pekin ducks (P < 0.05), and Thr-E did not affect BW, ADG, ADFI, or F/G (P > 0.05), compared with Thr-S. The diameter and cross-sectional area of the breast muscle fibers in the Thr-S group were larger than those in the Thr-D group (P < 0.05). RNA sequencing revealed 1,300 differential expressed genes (DEGs) between the Thr-D and Thr-S groups, of which 625 were upregulated and 675 were downregulated by Thr-D. KEGG analysis showed that the upregulated genes were enriched in mTOR, FoxO, Wnt, fat digestion and absorption, and other signaling pathways. The downregulated genes were enriched in the MAPK signaling, glycolysis/gluconeogenesis, adipocytokine signaling, and biosynthesis of unsaturated fatty acids signaling pathways. The genes of Wnt family member 3a (Wnt3a), myogenin, myozenin 2, and insulin like growth factor 2 mRNA binding protein were upregulated, and platelet derived growth factor subunit B, PDGF receptor beta and Wnt4 were downregulated by Thr deficiency, which involving in muscle development. Our findings indicated that Thr increased breast fiber size, perhaps because Thr affected the proliferation and differentiation of satellite cells in breast muscle of ducks after hatch. Our results provide novel insights into new understanding of the molecular mechanisms underlying breast muscle development in ducks subjected to dietary Thr.

Effects of linseed oil supplementation duration on fatty acid profile and fatty acid metabolism-related genes in the muscles of Chinese crested white ducks.

Meat rich in polyunsaturated fatty acids is considered beneficial to health. Supplementing the diet with linseed oil promotes the deposition of polyunsaturated fatty acids (PUFAs) in poultry, a conclusion that has been confirmed multiple times in chicken meat. However, fewer studies have focused on the effects of dietary fatty acids on duck meat. Therefore, this study aims to evaluate the effects of the feeding time of a linseed oil diet on duck meat performance and gene expression, including meat quality performance, plasma biochemical indicators, fatty acid profile, and gene expression. For this study, we selected 168 Chinese crested ducks at 28 days old and divided them into three groups, with 56 birds in each group. The linseed oil content in the different treatment groups was as follows: the control group (0% flaxseed oil), the 14d group (2% linseed oil), and the 28d group (2% linseed oil). Ducks in the two experimental groups were fed a linseed oil diet for 28 and 14 days at 28 and 42 days of age, respectively. The results showed that linseed oil had no negative effect on duck performance (slaughter rate, breast muscle weight, and leg muscle weight) or meat quality performance (pH, meat color, drip loss, and shear force) (P > 0.05). The addition of linseed oil in the diet increased plasma total cholesterol and high-density lipoprotein cholesterol levels (P < 0.05), while decreasing triglyceride content (P < 0.05). Furthermore, the supplementation of linseed oil for four weeks affected the composition of muscle fatty acids. Specifically, levels of α-linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid were increased (P < 0.05), while eicosatetraenoic acid content was negatively correlated with flaxseed oil intake (P < 0.05). qRT-PCR analysis further revealed that the expression of FATP1, FABP5, and ELOVL5 genes in the breast muscle, as well as FABP3 and FADS2 genes in the thigh muscle, increased after four weeks of linseed oil supplementation (P < 0.05). However, after two weeks of feeding, CPT1A gene expression inhibited fatty acid deposition, suggesting an increase in fatty acid oxidation (P < 0.05). Overall, the four-week feeding time may be a key factor in promoting the deposition of n-3 PUFAs in duck meat. However, the limitation of this study is that it remains unknown whether longer supplementation time will continue to affect the deposition of n-3 PUFAs. Further experiments are needed to explain how prolonged feeding of linseed oil will affect the meat quality traits and fatty acid profile of duck meat.

Metabolomics and Proteomics Characterizing Hepatic Reactions to Dietary Linseed Oil in Duck.

The imbalance in polyunsaturated fatty acid (PUFA) composition in human food is ubiquitous and closely related to obesity and cardiovascular diseases. The development of n-3 PUFA-enriched poultry products is of great significance for optimizing fatty acid composition. This study aimed to improve our understanding of the effects of dietary linseed oil on hepatic metabolism using untargeted metabolomics and 4D label-free proteome analysis. A total of 91 metabolites and 63 proteins showed differences in abundance in duck livers between the high linseed oil and control groups. Pathway analysis revealed that the biosynthesis of unsaturated fatty acids, linoleic acid, glycerophospholipid, and pyrimidine metabolisms were significantly enriched in ducks fed with linseed oil. Meanwhile, dietary linseed oil changed liver fatty acid composition, which was reflected in the increase in the abundance of downstream metabolites, such as α-linolenic acid (ALA; 18:3n-3) as a substrate, including n-3 PUFA and its related glycerophospholipids, and a decrease in downstream n-6 PUFA synthesis using linoleic acid (LA; 18:2n-6) as a substrate. Moreover, the anabolism of PUFA in duck livers showed substrate-dependent effects, and the expression of related proteins in the process of fatty acid anabolism, such as FADS2, LPIN2, and PLA2G4A, were significantly regulated by linseed oil. Collectively, our work highlights the ALA substrate dependence during n-3 PUFA synthesis in duck livers. The present study expands our knowledge of the process products of PUFA metabolism and provides some potential biomarkers for liver health.

Dietary linseed oil affects the polyunsaturated fatty acid and transcriptome profiles in the livers and breast muscles of ducks.

Linseed oil, an important source of dietary α-linolenic acid, is used to provide meat enriched in n-3 PUFA. We investigated the effects of dietary linseed oil (0, 0.5, 1, and 2%) on growth performance, meat quality, tissue fatty acid (FA), and transcriptome profiles in ducks. The result showed that dietary linseed oil had no effect on growth performance. Increasing dietary linseed oil enrichment raised n-3 PUFA and linoleic acid (LA) levels in both the liver and breast muscle, but decreased dihomo-gamma-linolenic acid (DGLA) and arachidonic acid (ARA) levels in the liver. The liver n-3 PUFA content was negatively correlated with duck body weight. Transcriptome analysis showed that dietary linseed oil caused hepatic changes in genes (SCD, FADS1, FADS2, and ACOT6) related to the biosynthesis of unsaturated fatty acids. Besides, dietary linseed oil also affected the expression of genes related to PUFAs and downstream metabolites (such as linoleic acid, steroid hormone, progesterone, etc.) metabolic pathways in both liver and breast muscle. Key genes involved in PUFA synthesis and transport pathways were examined by RT-qPCR, and the results verified that hepatic expression levels of FADS1 and FADS2 decreased, and those of FABP4 and FABP5 increased when 2% linseed oil was added. CD36 expression level increased in breast muscle when 2% linseed oil was added. Thus, 2% dietary linseed oil supplementation produces n-3 PUFA-enriched duck products by regulating the PUFA metabolic pathways, which could be advantageous for health-conscious consumers.

Report of the Largest Chinese Cohort With SLC19A3 Gene Defect and Literature Review.

Thiamine metabolism dysfunction syndrome 2 (THMD2) is a rare metabolic disorder caused by SLC19A3 mutations, inherited in autosomal recessive pattern. As a treatable disease, early diagnosis and therapy with vitamin supplementation is important to improve the prognosis. So far, the reported cases were mainly from Saudi Arab regions, and presented with relatively simple clinical course because of the hot spot mutation (T422A). Rare Chinese cases were described until now. In this study, we investigated 18 Chinese THMD2 patients with variable phenotypes, and identified 23 novel SLC19A3 mutations, which expanded the genetic and clinical spectrum of the disorder. Meanwhile, we reviewed all 146 reported patients from different countries. Approximately 2/3 of patients presented with classical BTBGD, while 1/3 of patients manifested as much earlier onset and poor prognosis, including infantile Leigh-like syndrome, infantile spasms, neonatal lactic acidosis and infantile BTBGD. Literature review showed that elevated lactate in blood and CSF, as well as abnormal OXPHOS activities of muscle or skin usually correlated with infantile phenotypes, which indicated poor outcome. Brainstem involvement on MRI was more common in deceased cases. Thiamine supplementation is indispensable in the treatment of THMD2, whereas combination of biotin and thiamine is not superior to thiamine alone. But biotin supplementation does work in some patients. Genotypic-phenotypic correlation remains unclear which needs further investigation, and biallelic truncated mutations usually led to more severe phenotype.

Mouse Model to Explore the Therapeutic Effect of Nano-Doxorubicin Drug Delivery System on Bladder Cancer.

To study the therapeutic effect of nano-dosin-loaded drug system in mouse bladder cancer, a luciferase-labeled mouse bladder cancer cell line and a mouse bladder cancer model were constructed. In vivo imaging monitors tumor growth and uses a combination of photothermal, immune, and chemotherapy to treat the mouse model. With doxorubicin as an antitumor drug carrier, the drug loading, in vitro drug release, cytotoxicity and behavior in cells of mesoporous nano particle-targeted drug delivery system were studied. The cells were injected into the bladder through the urethra, and the mouse bladder cancer subcutaneous model was treated with gelatin-coated single-walled carbon nanotube-encapsulated mouse granulocytes-macrophage colony-stimulating factor and doxorubicin. In the process of using, the use of near-infrared light for irradiation, thereby achieving the combined effect of photothermal, immune and chemotherapy. The experimental results show that the prepared doxorubicin prodrug delivery system can enhance the targeted therapeutic effect and reduce the toxicity and side effects of the drug. Especially for those cancer cells or tissues with overexpression of folate receptors, it has a better therapeutic effect and provides reference for the treatment of subsequent bladder cancer.

Molecular cloning, expression and mimicking antiviral activity analysis of retinoic acid-inducible gene-I in duck (Anas platyrhynchos).

Intracellular double-stranded RNA (dsRNA) is a chief sign of replication for many viruses. Pattern recognition receptors(PRRs) of the innate immune system detected the dsRNA and initiate the antiviral responses. Retinoic acid-inducible gene I (RIG-I), a member of PRRs, plays an essential regulatory role in dsRNA-induced signalling. In this study, the full-length complementary DNA (cDNA) of duck RIG-I (duRIG-I) was cloned using the reverse transcription-polymerase chain reaction (RT-PCR) and rapid amplification of the cDNA ends (RACE). The cDNA of duRIG-I contained 97-bp 5'UTR, 141-bp 3'-UTR and 2802 bp complete open-reading frame (ORF) encoding 933 amino acids. Multiple sequence alignments showed that duRIG-I shared high similarity with RIG-I from other vertebrates. Quantitative real-time PCR (qRT-PCR) analysis revealed that duRIG-I mRNA was expressed in all tested tissues, with high levels in the liver, heart, spleen, kidney and thymus, while lower in the duodenum. duRIG-I could be induced by treatment with poly(I:C). Further, overexpression of duRIG-I significantly activated the transcription of poly(I:C)-induced IFN-b, IRF7, TRIF, Mx, STAT1 and STAT2 mRNA, and duRIG-I knockdown showed the opposite results. Overall, our results suggested that duRIG-I could be an important receptor for mimicking antiviral state in duck, which warrant further studies to show the possible mechanism.

Research Note: Effect of diet with different proportions of ryegrass on breast meat quality of broiler geese.

This study was conducted to determine the effects of diet with different proportions of ryegrass on breast meat quality of geese. In total, 240 healthy male Yangzhou geese (28-day-old) with similar body weight were divided randomly into 4 diet groups (control group: fed commercial diets; treatment groups I, II, and III: fed ryegrass and commercial diet in the ratios of 1.5:1, 2:1, and 3:1, respectively), the birds being fed from the age of 29 to 70 D. The results shows that the body weights of 70-day-old geese of treatment groups II and III were lower than those in the control group, whereas those of geese of treatment group I were similar to those of the control group. The contents of flavor amino acid and total (essential) amino acids in treatment groups I and II were higher than those in treatment group III (P < 0.05). In addition, grass supplementation reduced saturated fatty acid content and increased that of omega-3 (n-3) polyunsaturated fatty acids, relative to the control group (P < 0.05). Finally, among the 6 minerals analyzed in breast muscle, differences existed in Zn, Se, and Cu contents among the geese fed with different proportions of ryegrass. Zn content of geese from treatment groups II and III was significantly higher than that of those of the control group; Cu content was lower with grass intake and was significantly higher in the control group than in treatment group III; Se content was significantly higher in the control group than in both groups II and III (all at P < 0.05). The results from this study indicated that geese fed with low proportions of ryegrass (1.5:1 or 2:1) showed good growth performance and increased total (essential) amino acid, flavor amino acid, n-3 polyunsaturated fatty acid, and Zn content in meat, which had a certain guiding value for the production of high-quality goose meat under intensive feeding conditions.

Effects of genetic selection and threonine on meat quality in Pekin ducks.

The present study was conducted to investigate the effects of genetic selection and threonine levels on meat quality in Pekin ducks. At 15 D of age, 192 lean ducks and 192 fatty ducks were selected and allotted to one of three treatments with 8 replicates with similar BW (8 ducks/cage), respectively. All ducks were fed the experimental diets (0.00, 0.15, and 0.30% added threonine) for 21 D from 15 to 35 D of age. The results showed that fatty ducks had higher (P < 0.001) feed intake, feed/gain ratio, abdominal fat percentage, and sebum percentage and lower (P = 0.001) breast muscle percentage compared with that of lean ducks. The fatty-type and lean-type ducks had similar weight gain and BW. Dietary threonine supplementation improved (P < 0.05) growth performance and increased breast muscle percentage in lean-type ducks, but it did not affect (P > 0.05) those indices in fatty-type ducks. Lean ducks had higher (P < 0.001) hepatic contents of total lipids, triglyceride, cholesterol, and plasma low-density lipoprotein cholesterol concentration, and dietary threonine supplementation decreased (P < 0.05) hepatic total lipid, cholesterol, and triglyceride contents in lean ducks, but it had no influence on hepatic lipids in fatty ducks (P > 0.05). Lean ducks had higher (P < 0.05) concentrations of monounsaturated fatty acid (MUFA), and C18-polyunsaturated fatty acid (PUFA) in the liver, PUFA in the breast muscle, and C18:3n6 and C18:3n3 in plasma and lower C20-PUFA and C22-PUFA in the liver and MUFA in plasma, compared with fatty ducks. Threonine supplementation increased PUFA, N3-PUFA, and n6-PUFA in plasma and hepatic fatty acids profiles in lean ducks (P > 0.05) but had on influence on total MUFA and total PUFA in the liver, breast muscle, and plasma in fatty ducks (P > 0.05). In conclusion, genetic selection toward meat production and threonine supplementation increases meat production and PUFA contents, which would influence eating quality, but it is benefit for human health.

Therapeutic targets of Traditional Chinese Medicine for colorectal cancer.

OBJECTIVE: To explore the role of Traditional Chinese Medicine (TCM) in the prevention and treatment of colorectal cancer and identify possible therapeutic targets of TCM to provide clues for the use of TCM for colorectal cancer prevention and treatment in the clinic and to find novel directions for new drug discovery for colorectal cancer. METHODS: We used PubMed and Google to search for and collect scientific publications for a full evalu- ation of current evidence in the literature indicating the potential role of Chinese herbal medicines and their respective ingredients as effective candidates for colorectal cancer prevention and treatment. RESULTS: We extracted a detailed description of potential therapeutic Chinese herbal medicines and their constituent ingredients that target different mechanisms in colorectal cancer such as gene mutation, dysregulation of signaling pathways, metabolism disorders, and the inflammatory microenvironment, including both conventional and non-conventional approaches. CONCLUSION: TCM may be a promising complementary and alternative therapy for the treatment of colorectal cancer.

Molecular characterization, expression patterns, and subcellular localization of RIG-I in the Jinding duck (Anas platyrhynchos domesticus).

Retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs) have recently been identified as cytoplasmic sensors for RNA virus. Recent research has shown that RIG-I, a member of this family, play an important role in innate immunity. In this study, we cloned the RIG-I gene from Jinding duck by reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE). We determined that the cDNA of duRIG-I contains a 14-bp 5' UTR, a 2802-bp open reading frame, and alternative 3' UTRs (295-bp and 927-bp) and encodes a polypeptide of 933 amino acids. Based on this sequence, the duRIG-I protein is predicted to have conserved domains typical of RLRs. In addition, duRIG-I was found to be distributed throughout DF1 cells by indirect immunofluorescence, as predicted. duRIG-I mRNA was scarcely detected in healthy tissues by semi-quantitative RT-PCR (sqRT-PCR). To study the role of RIG-I in innate immunity, we used synthetic double-stranded RNA to mimic viral infection in vivo and detected duRIG-I transcripts in spleen and liver by quantitative real-time PCR (qRT-PCR). The expression of duRIG-I mRNA was significantly elevated at 8h post-injection (P < 0.05) and was indistinguishable from control levels at other time points (P > 0.05). These results suggest that duRIG-I plays an important role in innate immune responses to double-stranded RNA viruses and warrant further studies to reveal the possible mechanism.