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单端孢霉烯毒素 单端孢霉烯毒素(trichothecene)是包含200～300种化合物的一类毒素,其中包括T-2毒素、二乙酰藨草镰刀烯醇(diacetooxyscirpenol,DAS)和脱氧雪腐镰刀菌烯醇(deoxynivalenol,DON),这些毒素常见于农产品中(Desjardins等,1993).它们通过在核糖体水上抑制蛋白质的合成而发挥其毒性作用,具有免疫抑制性和细胞膜毒性,可诱使细胞凋亡(Sharma,1993;Shifrin和Anderson,1999).单端孢霉烯毒素的毒性作用包括对胃肠道的影响,如引起呕吐、腹泻和肠炎;此外,贫血、白细胞减少、皮肤刺激、拒食、生长减缓和繁殖障碍等症状也很普遍.若干种镰刀菌及相关属的真菌会产生单端孢霉烯毒素.看来,除了DON外,大多数单端孢霉烯毒素污染发生在谷物收割前. 相似文献
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在12 947篇关于霉菌毒素的科学论文中,有3 000多篇涉及呕吐毒素.科学家们仅仅是最近十年才开始研究呕吐毒素对动物肠道的作用,数据仍然很有限.
几种镰刀菌能够产生呕吐毒素(DON),呕吐毒素是一种B型单端孢霉烯毒素.所有单端孢霉烯毒素的共同活性基团是环氧基,它使呕吐毒素结合在核糖体上阻止蛋白质合成.脱环氧代谢物DOM-1由于没有环氧基不能结合在核糖体上,所以没有毒性.
需要注意的是,呕吐毒素可以被真菌、植物、动物和细菌进一步衍生为几种不同的代谢物.这些呕吐毒素衍生物也被称为隐蔽霉菌毒素(表1). 相似文献
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霉菌毒素对母猪繁殖性能影响及解毒研究进展 总被引：1，自引：0，他引：1
《广东饲料》2015,(10)
霉菌毒素是霉菌代谢过程中自然产生的高毒性次生代谢产物。当前,影响我国养猪生产的主要霉菌毒素包括单端孢霉烯族毒素、玉米赤霉烯酮、赭曲霉毒素、黄曲霉毒素以及伏马菌素,这5类毒素能导致猪的生长抑制、氧化应激加剧、机能损伤、降低繁殖性能和后代数量和质量下降等负面影响,预防和解决霉菌毒素中毒已是养猪生产的重要课题。为此,本文针对霉菌毒素对母猪的毒性作用,以及解决毒素措施的研究进展进行综述,以期给养猪生产提供参考。 相似文献
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Elpetra P. M. Timmermans‐Sprang Helena M. Mestemaker Renske R. Steenlage Jan A. Mol 《Veterinary and comparative oncology》2019,17(3):413-426
Human epidermal growth factor 2 (HER2) overexpression leads to aggressive mammary tumour growth. Although the prognosis of HER2+ tumours in humans is greatly improved using biologicals, therapy resistance, which may be caused by increased phosphatidyl‐3‐kinase (PI3K), rous sarcoma proto‐oncogene (cSRC) or wingless‐type MMTV integration site family (Wnt) activity, is a major concern. A recent analysis of 12 canine mammary cell lines showed an association between HER2/3 overexpression and phosphatase and tensin homologue (PTEN) deletion with elevated Wnt‐signalling. Wnt‐activity appeared to be insensitive to phosphatidyl‐3‐kinase (PI3K) inhibitors but sensitive to Src‐I1. We hypothesized that Wnt activation, was caused by HER2/3‐activated cSRC activation. The role of HER2/3 on Wnt signalling was investigated by silencing HER2/3 expression using specific small interfering RNA (siRNAs). Next, the effect of an epidermal growth factor receptor (EGFR)/HER2 tyrosine kinase inhibitor on Wnt activity and migration was investigated and compared to other tyrosine kinase inhibitors (TKIs) of related signalling pathways. Finally, two TKIs, a cSRC and a PI3K inhibitor, were investigated in a zebrafish xenograft model. Silencing of HER1‐3 did not inhibit the intrinsic high Wnt activity, whereas the HER kinase inhibitor afatinib showed enhanced Wnt activity. The strongest inhibition of Wnt activity and cell viability and migration was shown by cSRC inhibitors, which also showed strong inhibition of cell viability and metastasis in a zebrafish xenograft model. HER2/3 overexpression or HER2/3‐induced cSRC activation is not the cause of enhanced Wnt activity. However, inhibition of cSRC resulted in a strong inhibition of Wnt activity and cell migration and metastasis. Further studies are needed to unravel the mechanism of cSRC activation and cSRC inhibition to restore sensitivity to HER‐inhibitors in HER2/3‐positive breast cancer. 相似文献
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《动物营养（英文）》2020,6(1):98-106
As major fuels for the small intestinal mucosa, dietary amino acids (AA) are catabolized in the mitochondria and serve as sources of energy production. The present study was conducted to investigate AA metabolism that supply cell energy and the underlying signaling pathways in porcine enterocytes. Intestinal porcine epithelial cells (IPEC-J2) were treated with different concentrations of AA, inhibitor, or agonist of mammalian target of rapamycin complex 1 (mTORC1) and adenosine monophosphate activated protein kinase (AMPK), and mitochondrial respiration was monitored. The results showed that AA treatments resulted in enhanced mitochondrial respiration, increased intracellular content of pyruvic acid and lactic acid, and increased hormone-sensitive lipase mRNA expression. Meanwhile, decreased citrate synthase, isocitrate dehydrogenase alpha, and carnitine palmitoyltransferase 1 mRNA expression were also observed. We found that AA treatments increased the protein levels of phosphorylated mammalian target of rapamycin (p-mTOR), phosphorylated-p70 ribosomal protein S6 kinase, and phosphorylated-4E-binding protein 1. What is more, the protein levels of phosphorylated AMPK α (p-AMPKα) and nicotinamide adenine dinucleotide (NAD)-dependent protein deacetylase sirtuin-1 (SIRT1) were decreased by AA treatments in a time depending manner. Mitochondrial bioenergetics and the production of tricarboxylic acid cycle intermediates were decreased upon inhibition of mTORC1 or AMPK. Moreover, AMPK activation could up-regulate the mRNA expressions of inhibitor of nuclear factor kappa-B kinase subunit beta (Ikbkβ), integrin-linked protein kinase (ILK), unconventional myosin-Ic (Myo1c), ribosomal protein S6 kinase beta-2 (RPS6Kβ2), and vascular endothelial growth factor (VEGF)-β, which are downstream effectors of mammalian target of rapamycin (mTOR). The mRNA expressions of phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit delta isoform (PIK3CD) and 5′-AMP-activated protein kinase subunit gamma-1 (PRKAG1), which are upstream regulators of mTOR, were also up-regulated by AMPK activation. On the other hand, AMPK activation also down-regulated FK506-binding protein 1A (FKBP1A), serine/threonine-protein phosphatase 2A 55 kDa regulatory subunit B beta isoform, phosphatase and tensin homolog (PTEN), and unc-51 like autophagy activating kinase 1 (Ulk1), which are up-stream regulators of mTORC1. Taken together, these data indicated that AA regulated cellular energy metabolism through mTOR and AMPK pathway in porcine enterocytes. These results demonstrated interactions of AMPK and mTORC1 pathways in AA catabolism and energy metabolism in intestinal mucosa cells of piglets, and also provided reference for using AA to remedy human intestinal diseases. 相似文献
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Huimin Zhao Tingting Li Huan Yang Muhammad Usman Mehmood Yangqing Lu Xingwei Liang Xiaogan Yang Huiyan Xu Kehuan Lu Shengsheng Lu 《Reproduction in domestic animals》2019,54(12):1574-1582
The objective of this study was to investigate the effects of different growth factors on the proliferation of Bama mini‐pig spermatogonial stem cells (SSCs) in vitro. The growth factors glial cell line‐derived neurotrophic factor (GDNF), leukaemia inhibitory factor (LIF), GDNF family receptor alpha‐1 (GFRα1) and basic fibroblast growth factor (bFGF) were investigated. The SSCs were seeded on SIM mouse embryo‐derived thioguanine‐ and ouabain‐resistant (STO) feeder layers. Cultivation of the cells were subjected to a factorial design of the growth factors GDNF + bFGF, GDNF + bFGF + GFRα1, LIF + bFGF and LIF + bFGF + GFRα1. The SSCs could propagate for 25 passages in the medium adding GDNF + bFGF + GFRα1, 22 passages in the medium adding GDNF + bFGF, 6 passages in the medium adding LIF + bFGF, or LIF + bFGF + GFRα1. qRT‐PCR analysis showed that the highest mRNA expression levels of NANOG, POU5F, DDX4, GFRα1 and UCHL1 were detected in the group adding GDNF + bFGF + GFRα1. The SSCs from the group adding GDNF + bFGF + GFRα1 also showed UCHL1‐, DBA‐ and CDH1‐positive staining. Moreover, Stra8 and Scp3 expression, and haploid peak were detected after induction of the SSCs from the group adding GDNF + bFGF + GFRα1. In conclusion, pig SSCs could be maintained for long term in the presence of GDNF, bFGF, and GFRα1. 相似文献
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核苷酸结合寡聚化结构域样受体蛋白1（NLRP1）是NOD样受体（nucleotide-binding oligomerization domain-like receptors，NLRs）家族的成员，是人们发现的第一个能形成炎性小体的蛋白。NLRP1的激活可引起半胱氨酸蛋白酶-1前体（pro-caspase-1）的活化并进一步促进炎性因子的成熟和释放，在天然免疫中发挥着重要作用。NLRP1的结构在不同种属间存在差异，目前能引起NLRP1激活的机制，主要包括通过蛋白酶体途径降解并激活NLRP1、通过抑制DPP9激活NLRP1以及弓形虫和部分代谢抑制剂激活NLRP1等。某些病毒蛋白或RNA也能够激活NLRP1，其具体激活机制以及NLRP1在抗病毒感染中发挥的作用尚未明确，还有待于进一步研究。 相似文献
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Lysnyansky I Gerchman I Levisohn S Mikula I Feberwee A Ferguson NM Noormohammadi AH Spergser J Windsor HM 《Veterinary microbiology》2012,156(1-2):222-226
This study evaluated the in vitro activity of diphenyl diselenide against 19 Pythium insidiosum isolates and the in vivo therapeutic response of rabbits with experimentally induced pythiosis. In vitro: susceptibility tests were performed using the broth macrodilution method in accordance with the CLSI document M38-A2. The criteria for interpretation were as follows: MIC-1 and MIC-2 (inhibition of 90% and 100% of mycelium growth, respectively) and the minimum fungicide concentration (MIC-3). In vivo: twenty rabbits were divided into four groups with five animals each and treated for 40 consecutive days: groups 1 and 2 (experimentally induced pythiosis) were treated with diphenyl diselenide (10mg/kg/day) and canola oil (1 mL/kg/day), respectively; groups 3 and 4 (controls) were treated with canola oil (1 mL/kg/day) and diphenyl diselenide (10mg/kg/day), respectively. Toxicity was evaluated using biochemical and haematological parameters. In vitro susceptibility tests showed that 89.4% of isolates had a MIC-1 ≤ 0.5 μg/mL, 84.2% of isolates had a MIC-2 ≤ 1.0 μg/mL and 94.7% of isolates had a MIC-3 ≤ 2.0 μg/mL. The in vivo assay suggested that this compound has a fungistatic activity, and the biochemical and haematological parameters indicated that there was no renal, hepatic or haematological toxicity. The comparison of the unsaturated iron binding capacity levels between animals with and without pythiosis suggested the involvement of iron metabolism in the pathogenesis of pythiosis. This study demonstrated the absence of detectable toxicity caused by diphenyl diselenide and the in vitro fungicidal and in vivo fungistatic activities of this drug, which makes it an option for future therapeutic approaches in the treatment of pythiosis. 相似文献
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Concentration effect of prostaglandin E2 on the growth factor expression and cell proliferation in bovine endometrial explants and their kinetic characteristics 
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下载免费PDF全文 S Zhang W Mao Q Li R Gao Y Zhang L Gao C Fu J Wu Y Deng Y Shen T Li B Liu J Cao 《Reproduction in domestic animals》2018,53(1):143-151
Bovine endometrium undergoes various physiological and histological changes that are necessary for blastocyst implantation during oestrous cycle. From pro‐oestrus to late‐oestrus, endometrium thickens gradually for implantation preparation and exhibits remarkable capacity for self‐repair after uterine lining shedding while implantation does not occur. The prostaglandin E2 (PGE 2) secretion pattern is synchronized with endometrial growth during oestrous cycles in bovine endometrium; however, limited information is available regarding the association between PGE 2 secretion and endometrial growth. In this study, the concentration (10?9 to 10?5 M) and time effect (2–36 hr) of PGE 2 treatment on a series of growth factors are essential for endometrial growth including connective tissue growth factor (CTGF ), fibroblast growth factor‐2 (FGF ‐2), interleukin‐8 (IL ‐8), transforming growth factor‐β1 (TGF ‐β1), matrix metalloproteinase‐2 (MMP ‐2), and vascular endothelial growth factor A (VEGFA ) mRNA and protein expression, and proliferation of epithelial and fibroblast cells was investigated in bovine endometrial explants in vitro. The results indicated that PGE 2 at concentration about 10?7 to 10?5 M could up‐regulate CTGF , FGF ‐2, IL ‐8, MMP ‐2, TGF ‐β1, VEGFA mRNA and protein expression, and could induce the proliferation of epithelial and fibroblast cells and reduce the proapoptotic factor (caspase‐3) expression in bovine endometrial explants in vitro. These results collectively improved the possibility of PGE 2 functions in endometrial growth during oestrous cycles. 相似文献
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T. O. Abegunde A. O. Akinsoyinu 《Journal of animal physiology and animal nutrition》2011,95(2):192-197
The replacement value of Ficus polita for Panicum maximum was evaluated on 32 female post‐weaned West African dwarfs goats. Ficus polita was fed with P. maximum at different proportions of 0:90 (F. polita:P. maximum), 30:60, 60:30 and 90:0 constituting diets 1, 2, 3 and 4 respectively. Each diet was supplemented with 10% cassava peels. Dry matter intake per kg metabolic weight of goats was not significantly (p > 0.05) influenced by the dietary treatments. However, crude protein intake per kg metabolic weight was higher (p < 0.05) in animals fed 60% and 90%F. polita than those fed sole P. maximum diet. Daily weight gain of goats fed diet 3 (60%F. polita) was higher (p < 0.05) (27.3 g) than those fed diets 4 (18.9 g), 2 (20.8 g) and the control (6.6 g). Dry matter (DM), organic matter, crude protein (CP) and neutral detergent fibre digestibilities were higher (p < 0.05) in goats fed 60%F. polita than those fed other diets, except for DM digestibility which was statistically similar to diets 2 and 4 but higher than those fed diet 1 without F. polita. Organic matter and CP digestibility were highest (72.0 and 65.7% respectively) in animals fed 60%F. polita. Nitrogen retention of goats fed 60%F. polita (diet 3) was higher (p < 0.05) than that obtained with other diets. The results suggest that feeding combination of F. polita and P. maximum at ratio 60:30 respectively has associative effects that can enhance growth rate, feed intake, nutrients digestibility and nitrogen utilization for goat production during dry season in the tropics. 相似文献