Effects of in ovo injection of vitamin C on heat shock protein and metabolic genes expression
Effects of in ovo injection of vitamin C on heat shock protein and metabolic genes expression
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DOI：
10.1017/s1751731118003531
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发表时间：
2020-02-01
期刊：
影响因子：
3.6
通讯作者：
Yang, X. J.
中科院分区：
文献类型：
--
作者：
Zhu, Y. F.;Bodinga, M. B.;Yang, X. J.
免疫力低下和多种应激是肉鸡行业面临的两大挑战。在胚胎期特定时间进行营养干预是提高动物生产性能的可行途径。本试验旨在研究胚龄15 d（E15）蛋内饲喂维生素C（VC）对肉仔鸡生长性能、抗氧化能力和免疫功能的影响。将240枚肉仔鸡受精卵随机分为2组（E15时注射0和3 mg维生素C），孵化后将每组的雏鸡随机分为6个重复，每个重复10只。结果表明，卵内注射维生素C能显著提高孵化率（P < 0.05），提高1日龄（D1）肉仔鸡免疫球蛋白M（IgM）、血浆IgG和IgM含量（D21）、溶菌酶活性（D21，P < 0.05）和总抗氧化能力（D42，P < 0.01）。D21时，VC组脾脏DNA甲基转移酶1（DNMT 1）表达水平上调，而白细胞介素6（IL-6）、干扰素γ（IFN-γ）、10 - 11易位蛋白1（ten-111 translocation protein 1）和胸腺嘧啶-DNA糖基化酶表达水平下调（P < 0.05）。在D42，卵内注射维生素C可上调脾脏DNMT 1、DNA甲基转移酶3B（DNMT 3B）、生长停滞蛋白和DNA损伤诱导蛋白β的表达水平（P < 0.05），而下调IL-6、肿瘤坏死因子α和甲基CpG结合域蛋白4的表达水平（P < 0.05）。结果表明，在E15时给予3 mg维生素C的IOF可在一定程度上提高血浆中的抗氧化活性和免疫功能，并降低脾脏中促炎细胞因子的表达。然而，维生素C的IOF导致DNA甲基转移酶和去甲基化酶表达的变化可能提示脾脏DNA甲基化水平有升高的趋势，DNA甲基化变化是否与脾脏促炎细胞因子表达降低有关还有待进一步研究。有研究表明，过度的代谢产热是鸡胚胎发育后期死亡的主要原因。提高热休克蛋白（HSP）的表达，调节机体代谢是维持机体热应激稳态的重要途径。本研究旨在探讨胚胎第11天（E11）卵内注射维生素C（VC）对HSP及其代谢基因表达的影响。将320枚种蛋随机分为生理盐水组和VC注射组。检测鸡1日龄血浆VC含量和肛温，检测E14、16、18胚胎肝脏HSP和代谢相关基因的mRNA水平，分析差异表达基因的启动子甲基化水平，预测启动子区域的转录因子。结果表明，维生素C的IOI显著提高血浆维生素C含量，降低直肠温度（P < 0.05）。卵内注射维生素C可显著增加E16时热休克蛋白60（HSP 60）和丙酮酸脱氢酶激酶4（PDK 4）基因表达，E18时PDK 4基因表达和分泌卷曲相关蛋白1（SFRP 1）（P < 0.05）。在E16时，VC的IOI显著降低总CpG位点和HSP 60启动子-336CpG位点及PDK 4启动子-1137CpG位点的甲基化水平（P < 0.05）。在HSP 60启动子区的-389和-336CpG位点发现了核因子-1的潜在结合位点，在PDK 4启动子区的-1137CpG位点发现了特异性蛋白1的潜在结合位点。结果提示，维生素C IOI诱导E16和E18小鼠HSP 60、PDK 4和SFRP 1基因表达增加，可能与基因启动子区去甲基化有关。VC的IOI是否能提高孵化率，还需通过设置不注射组进一步验证。
Hypoimmunity and numerous stresses are two major challenges in broiler industry. Nutrient intervention at the specific time of embryonic stage is a feasible way to improve animal performance. This study was conducted to investigate the possible effects of in ovo feeding (IOF) of vitamin C at embryonic age 15(th) day (E15) on growth performance, antioxidation and immune function of broilers. A total of 240 broiler fertile eggs were randomly divided into two groups (0 and 3 mg injected dose of vitamin C at E15), and new-hatched chicks from each treatment were randomly allocated into six replicates with 10 chicks per replicate after incubation. The results indicated that in ovo vitamin C injection improved the hatchability (P < 0.05) and increased immunoglobulin M (IgM) (at the broiler's age 1(st) day, D1), IgG and IgM concentrations (D21), as well as lysozyme activity (D21, P < 0.05) and total antioxidant capacity (D42, P < 0.01) in plasma of broilers. On D21, the splenic expression level of DNA methyltransferase 1 (DNMT1) was up-regulated in vitamin C (VC) group, whereas interleukin (IL)-6, interferon-gamma, ten-eleven translocation protein 1 and thymine-DNA glycosylase were down-regulated (P < 0.05). On D42, in ovo vitamin C injection up-regulated splenic expression levels of DNMT1, DNA methyltransferase 3B (DNMT3B) and growth arrest and DNA-damage-inducible protein beta (P < 0.05), whereas down-regulated splenic expression levels of IL-6, tumour necrosis factor-alpha and methyl-CpG-binding domain protein 4 (P < 0.05). Our findings suggested that IOF of 3 mg vitamin C at E15 could improve, to some extent, the antioxidant activity and immune function in plasma, corresponding with the lower expression of pro-inflammatory cytokines in spleen. However, IOF of vitamin C leading to the changes in the expression of DNA methyltransferases and demethylases may suggest an increased trend of DNA methylation level in spleen and whether DNA methylation variation is associated with the lower expression of pro-inflammatory cytokines in spleen warrants future study.Some studies have shown that the excessive metabolic heat production is the primary cause for dead chicken embryos during late embryonic development. Increasing heat shock protein (HSP) expression and adjusting metabolism are important ways to maintain body homeostasis under heat stress. This study was conducted to investigate the effects of in ovo injection (IOI) of vitamin C (VC) at embryonic age 11th day (E11) on HSP and metabolic genes expression. A total of 320 breeder eggs were randomly divided into normal saline and VC injection groups. We detected plasma VC content and rectal temperature at chick's age 1st day, and the mRNA levels of HSP and metabolic genes in embryonic livers at E14, 16 and 18, analysed the promoter methylation levels of differentially expressed genes and predicted transcription factors at the promoter regions. The results showed that IOI of VC significantly increased plasma VC content and decreased rectal temperature (P < 0.05). In ovo injection of VC significantly increased heat shock protein 60 (HSP60) and pyruvate dehydrogenase kinase 4 (PDK4) genes expression at E16 and PDK4 and secreted frizzled related protein 1 (SFRP1) at E18 (P < 0.05). At E16, IOI of VC significantly decreased the methylation levels of total CpG sites and -336 CpG site in HSP60 promoter and -1137 CpG site in PDK4 promoter (P < 0.05). Potential binding sites for nuclear factor-1 were found around -389 and -336 CpG sites in HSP60 promoter and potential binding site for specificity protein 1 was found around -1137 CpG site in PDK4 promoter. Our results suggested that IOI of VC increased HSP60, PDK4 and SFRP1 genes expression at E16 and 18, which may be associated with the demethylation in gene promoters. Whether IOI of VC could improve hatchability needs to be further verified by setting uninjection group.