The ruminal mucosal epithelium can secrete defensins, which play a key role in innate and adaptive immunity and are considered potential replacements for antibiotics. Of these, sheep β-defensin-1 (SBD-1) is one of the most potent molecules produced by ovine ruminal epithelial cells (ORECs). β-glucan, safe and effective immune activators, can stimulate innate and adaptive immune responses. Here we examined whether β-glucan from Saccharomyces cerevisiae can induce SBD-1 expression in ORECs, as well as the underlying mechanism. First, ORECs were cultured, and quantitative real-time PCR (qPCR) and enzyme-linked immunosorbent assay (ELISA) were used to study the effects of different β-glucan concentrations. Then western blotting, immunohistochemistry, and immunocytofluorescence were performed to investigate the regulatory mechanism of β-glucan-induced SBD-1 upregulation. We show that β-glucan can induce the release of SBD-1 from ORECs; the highest SBD-1 mRNA and protein expression was achieved after treatment with 10 μg/mL at 2 and 4 h. Moreover, β-glucan-induced SBD-1 production was mediated by the activation of dendritic-cell-associated C-type lectin 1 (Dectin-1) receptors, Syk, and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). These findings highlight the immunomodulatory effects of β-glucan on ORECs.

中文翻译：

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来自酿酒酵母的β-葡聚糖通过Dectin-1-Syk-NF-κB信号传导途径诱导绵羊瘤胃上皮细胞中SBD-1的产生。

瘤胃粘膜上皮可以分泌防御素，其在先天和适应性免疫中起关键作用，被认为是抗生素的潜在替代品。其中，绵羊β-防御素1（SBD-1）是绵羊瘤胃上皮细胞（OREC）产生的最有效的分子之一。β-葡聚糖是安全有效的免疫激活剂，可以刺激先天性和适应性免疫反应。在这里，我们检查了来自酿酒酵母的β-葡聚糖是否可以诱导ORECs中SBD-1的表达及其潜在机制。首先，培养ORECs，并使用实时定量PCR（qPCR）和酶联免疫吸附测定（ELISA）来研究不同浓度的β-葡聚糖的影响。然后进行蛋白质印迹，免疫组织化学，免疫细胞荧光法研究了β-葡聚糖诱导的SBD​​-1上调的调控机制。我们表明，β-葡聚糖可以诱导SREC-1从ORECs的释放。在2 h和4 h用10μg/ mL处理后，SBD-1 mRNA和蛋白的表达最高。此外，β-葡聚糖诱导的SBD​​-1产生是通过激活树突状细胞相关的C型凝集素1（Dectin-1）受体，Syk和活化的B细胞的核因子κ轻链增强剂介导的。 （NF-κB）。这些发现突出了β-葡聚糖对OREC的免疫调节作用。β-葡聚糖诱导的SBD​​-1产生是通过树突状细胞相关的C型凝集素1（Dectin-1）受体，Syk和活化的B细胞核因子kappa轻链增强子（NF）的激活介导的-κB）。这些发现突出了β-葡聚糖对OREC的免疫调节作用。β-葡聚糖诱导的SBD​​-1产生是通过激活树突状细胞相关的C型凝集素1（Dectin-1）受体，Syk和活化的B细胞核因子kappa-轻链增强子（NF）介导的-κB）。这些发现突出了β-葡聚糖对OREC的免疫调节作用。