Background Micro algae's are worldwide considered as an alternative source of proteins in diets for animals and humans. Micro algae also produce an array of biological active substances with potential to induce beneficial and health promoting effects. To better understand the mode of action of micro algae's when applied as additive in diets, porcine intestinal epithelial cells (IPEC-J2), stressed by enterotoxigenic Escherichia coli (ETEC) or under non-stressed conditions, were exposed to micro algae extracts and changes in gene expression were recorded. Methods IPEC-J2 cells were exposed for 2 and 6 h to extracts prepared from the biomass of the microalgae Chlorella vulgaris (C), Haematococcus pluvialis (H), Spirulina platensis (S), or a mixture of Scenedesmus obliques and Chlorella sorokiniana (AM), in the absence and presence of ETEC. Gene expression in cells was measured using porcine "whole genome" microarrays. Results The micro algae extracts alone enhanced the expression of a set of genes coding for proteins with biological activity that are secreted from cells. These secreted proteins (hereafter denoted as effector proteins; EPs) may regulate processes like remodelling of the extracellular matrix, activation of an antiviral/bacterial response and oxygen homeostasis in the intestine and periphery. Elevated gene expression of immunostimulatory proteins CCL17, CXCL2, CXCL8 (alias IL8), IFNA, IFNL1, HMOX1, ITGB3, and THBS1 was observed in response to all four extracts in the absence or presence of ETEC. For several of these immunostimulatory proteins no elevated expression was observed when cells were exposed to ETEC alone. Furthermore, all extracts highly stimulated expression of an antisense RNA of the mitochondrial/peroxisome symporter SLC25A21 gene in ETEC-challenged cells. Inhibition of SLC25A21 translation by this antisense RNA may impose a concentration gradient of 2-oxoadipic and 2-oxoglutarate, both metabolites of fatty acid β-oxidation, between the cytoplasm and the interior of these organelles. Conclusions Exposure of by ETEC stressed intestinal epithelium cells to micro algae extracts affected "fatty acid β-oxidation", ATP and reactive oxygen species production and (de) hydroxylation of lysine residues in procollagen chains in these cells. Elevated gene expression of specific EPs and immunostimulatory proteins indicated that micro algae extracts, when used as feed/food additive, can steer an array of metabolic and immunological processes in the intestines of humans and monogastric animals stressed by an enteric bacterial pathogen.

中文翻译：

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在存在和不存在产肠毒素大肠杆菌的情况下，培养的猪肠上皮细胞对微藻提取物的转录反应。

背景微藻在世界范围内被认为是动物和人类饮食中蛋白质的替代来源。微藻还产生一系列具有潜在诱导有益和促进健康作用的生物活性物质。为了更好地了解微藻作为日粮添加剂的作用模式，将猪肠上皮细胞 (IPEC-J2) 在产肠毒素大肠杆菌 (ETEC) 胁迫下或在非胁迫条件下暴露于微藻提取物和变化记录基因表达。方法 IPEC-J2 细胞暴露于由微藻类小球藻 (C)、雨生红球藻 (H)、扁平螺旋藻 (S) 或斜栅藻和小球藻 (AM) 的生物量制备的提取物中 2 和 6 小时)，在 ETEC 不存在和存在的情况下。使用猪“全基因组”微阵列测量细胞中的基因表达。结果 单独的微藻提取物增强了一组编码从细胞分泌的具有生物活性的蛋白质的基因的表达。这些分泌蛋白（以下称为效应蛋白；EP）可以调节诸如细胞外基质重塑、抗病毒/细菌反应激活以及肠道和外周氧稳态等过程。在不存在或存在 ETEC 的情况下，对所有四种提取物的反应都观察到免疫刺激蛋白 CCL17、CXCL2、CXCL8（别名 IL8）、IFNA、IFNL1、HMOX1、ITGB3 和 THBS1 的基因表达升高。对于这些免疫刺激蛋白中的一些，当细胞单独暴露于 ETEC 时，没有观察到表达升高。此外，所有提取物都高度刺激了 ETEC 攻击细胞中线粒体/过氧化物酶体转运体 SLC25A21 基因的反义 RNA 的表达。这种反义 RNA 对 SLC25A21 翻译的抑制可能会在细胞质和这些细胞器内部之间产生 2-氧代己二酸和 2-氧代戊二酸的浓度梯度，这两种代谢物都是脂肪酸 β-氧化的代谢产物。结论 ETEC 应激的肠上皮细胞暴露于微藻提取物会影响这些细胞中前胶原链中赖氨酸残基的“脂肪酸 β 氧化”、ATP 和活性氧的产生以及（去）羟基化。特定 EP 和免疫刺激蛋白的基因表达升高表明微藻提取物在用作饲料/食品添加剂时，