Institute for Medical Microbiology, Virology, and Hygiene, Rostock University Medical Center, Schillingallee 70, D-18057 Rostock, Germany.
Exp Cell Res. 2013 Nov 1;319(18):2883-92. doi: 10.1016/j.yexcr.2013.08.020. Epub 2013 Aug 27.
Adult mesenchymal stem cells (MSC) are present in several tissues, e.g. bone marrow, heart muscle, brain and subcutaneous adipose tissue. In invasive infections MSC get in contact with bacteria and bacterial components. Not much is known about how bacterial pathogens interact with MSC and how contact to bacteria influences MSC viability and differentiation potential. In this study we investigated the impact of three different wound infection relevant bacteria, Escherichia coli, Staphylococcus aureus, and Streptococcus pyogenes, and the cell wall components lipopolysaccharide (LPS; Gram-negative bacteria) and lipoteichoic acid (LTA; Gram-positive bacteria) on viability, proliferation, and osteogenic as well as adipogenic differentiation of human adipose tissue-derived mesenchymal stem cells (adMSC). We show that all three tested species were able to attach to and internalize into adMSC. The heat-inactivated Gram-negative E. coli as well as LPS were able to induce proliferation and osteogenic differentiation but reduce adipogenic differentiation of adMSC. Conspicuously, the heat-inactivated Gram-positive species showed the same effects on proliferation and adipogenic differentiation, while its cell wall component LTA exhibited no significant impact on adMSC. Therefore, our data demonstrate that osteogenic and adipogenic differentiation of adMSC is influenced in an oppositional fashion by bacterial antigens and that MSC-governed regeneration is not necessarily reduced under infectious conditions.
成人间充质干细胞（MSC）存在于多种组织中，如骨髓、心肌、脑和皮下脂肪组织。在侵袭性感染中，MSC 会与细菌及其组成成分接触。目前对于细菌病原体如何与 MSC 相互作用以及与细菌接触如何影响 MSC 的活力和分化潜能知之甚少。在这项研究中，我们研究了三种不同的伤口感染相关细菌，即大肠杆菌、金黄色葡萄球菌和化脓性链球菌，以及细胞壁成分脂多糖（LPS；革兰氏阴性菌）和脂磷壁酸（LTA；革兰氏阳性菌）对人脂肪组织来源的间充质干细胞（adMSC）活力、增殖以及成骨和脂肪分化的影响。我们表明，所有三种测试的物种都能够附着和内化到 adMSC 中。热灭活的革兰氏阴性大肠杆菌和 LPS 能够诱导 adMSC 的增殖和成骨分化，但降低脂肪分化。值得注意的是，热灭活的革兰氏阳性物种对增殖和脂肪分化也表现出相同的影响，而其细胞壁成分 LTA 对 adMSC 没有显著影响。因此，我们的数据表明，细菌抗原以相反的方式影响 adMSC 的成骨和脂肪分化，并且在感染条件下 MSC 控制的再生不一定会减少。
