Antimicrobial peptides secreted by equine mesenchymal stromal cells inhibit the growth of bacteria commonly found in skin wounds.
Antimicrobial peptides secreted by equine mesenchymal stromal cells inhibit the growth of bacteria commonly found in skin wounds.
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DOI：
10.1186/s13287-017-0610-6
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发表时间：
2017-07-04
影响因子：
7.5
通讯作者：
Van de Walle GR
中科院分区：
文献类型：
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作者：
Harman RM;Yang S;He MK;Van de Walle GR
慢性皮肤伤口在人类中的患病率很高，并且治疗经常由于病原菌的存在而变得复杂。因此，需要安全和创新的治疗方法来减少皮肤伤口中的细菌负荷。间充质基质细胞（MSC）可提供旁分泌信号，作用于皮肤细胞，促进伤口愈合，但其潜在的抗菌活性尚不清楚。本研究旨在检测来自马的MSC的抗菌特性，因为这种动物模型为MSC在人体中的治疗提供了一种易于转化的模型。具体而言，我们的目的是（i）评价马MSC对皮肤伤口中常见的代表性革兰氏阴性和革兰氏阳性细菌种属生长的体外作用，以及（ii）确定MSC抑制细菌生长的机制。从健康马的外周血中分离MSC。革兰氏阴性菌E.大肠杆菌和革兰氏阳性S.在MSC和含有MSC分泌的所有因子的MSC条件培养基（CM）存在下培养金黄色葡萄球菌。通过平板接种细菌并计数活菌落或通过阅读细菌培养物的吸光度来测量细菌生长。通过掺入N-苯基-1-萘胺（NPN）检测细菌膜损伤。采用RT-PCR和Western blot方法分别检测了抗菌肽（AMP）基因和蛋白在马MSC中的表达。用AMP特异性抗体阻断MSC CM的AMP活性。我们发现马MSC和MSC CM对E. coli和革兰氏阳性菌S.金黄色葡萄球菌，MSC CM使这些细菌细胞膜去极化。此外，我们发现马MSC CM含有AMP，用抗体阻断这些AMP可降低MSC CM对细菌的作用。我们的结果表明，马MSC抑制细菌生长并分泌破坏皮肤伤口中常见细菌膜完整性的因子。我们还鉴定了由马MSC产生的四种特异性AMP。AMP的分泌可能有助于MSC作为马和人的皮肤创伤的治疗剂的价值。
The prevalence of chronic skin wounds in humans is high, and treatment is often complicated by the presence of pathogenic bacteria. Therefore, safe and innovative treatments to reduce the bacterial load in cutaneous wounds are needed. Mesenchymal stromal cells (MSC) are known to provide paracrine signals that act on resident skin cells to promote wound healing, but their potential antibacterial activities are not well described. The present study was designed to examine the antibacterial properties of MSC from horses, as this animal model offers a readily translatable model for MSC therapies in humans. Specifically, we aimed to (i) evaluate the in vitro effects of equine MSC on the growth of representative gram-negative and gram-positive bacterial species commonly found in skin wounds and (ii) define the mechanisms by which MSC inhibit bacterial growth. MSC were isolated from the peripheral blood of healthy horses. Gram-negative E. coli and gram-positive S. aureus were cultured in the presence of MSC and MSC conditioned medium (CM), containing all factors secreted by MSC. Bacterial growth was measured by plating bacteria and counting viable colonies or by reading the absorbance of bacterial cultures. Bacterial membrane damage was detected by incorporation of N-phenyl-1-naphthylamine (NPN). Antimicrobial peptide (AMP) gene and protein expression by equine MSC were determined by RT-PCR and Western blot analysis, respectively. Blocking of AMP activity of MSC CM was achieved using AMP-specific antibodies. We found that equine MSC and MSC CM inhibit the growth of E. coli and S. aureus, and that MSC CM depolarizes the cell membranes of these bacteria. In addition, we found that equine MSC CM contains AMPs, and blocking these AMPs with antibodies reduces the effects of MSC CM on bacteria. Our results demonstrate that equine MSC inhibit bacterial growth and secrete factors that compromise the membrane integrity of bacteria commonly found in skin wounds. We also identified four specific AMPs produced by equine MSC. The secretion of AMPs may contribute to the value of MSC as a therapy for cutaneous wounds in both horses and humans.