Markel Troy A, Crisostomo Paul R, Wang Meijing, Herring Christine M, Meldrum Daniel R
Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Am J Physiol Gastrointest Liver Physiol. 2007 Oct;293(4):G657-62. doi: 10.1152/ajpgi.00230.2007. Epub 2007 Jul 19.
Necrotizing enterocolitis (NEC) is an emergency of the newborn that often requires surgery. Growth factors from stem cells may aid in decreasing intestinal damage while also promoting restitution. We hypothesized that 1) TNF, LPS, or hypoxia would alter bone marrow mesenchymal stem cell (BMSC) TNF, IGF-1, IL-6, and VEGF production, and 2) TNF receptor type 1 (TNFR1) or type 2 (TNFR2) ablation would result in changes to the patterns of cytokines and growth factors produced. BMSCs were harvested from female wild-type (WT), TNFR1 knockout (KO), and TNFR2KO mice. Cells were stimulated with TNF, LPS, or hypoxia. After 24 h, cell supernatants were assayed via ELISA. Production of TNF and IGF-1 was decreased in both knockouts compared with WT regardless of the stimulus utilized, whereas IL-6 and VEGF levels appeared to be cooperatively regulated by both the activated TNF receptor and the initial stimulus. IL-6 was increased compared with WT in both knockouts following TNF stimulation but was significantly decreased with LPS. Compared with WT, hypoxia increased IL-6 in TNFR1KO but not TNFR2KO cells. TNF stimulation decreased VEGF in TNFR2KO cells, whereas TNFR1 ablation resulted in no change in VEGF compared with WT. TNFR1 ablation resulted in a decrease in VEGF following LPS stimulation compared with WT; no change was noted in TNFR2KO cells. With hypoxia, TNFR1KO cells expressed more VEGF compared with WT, whereas no difference was noted between WT and TNFR2KO cells. TNF receptor ablation modifies BMSC cytokine production. Identifying the proper stimulus and signaling cascades for the production of desired growth factors may be beneficial in maximizing the therapeutic potential of stem cells.
坏死性小肠结肠炎（NEC）是新生儿的一种急症，通常需要进行手术。干细胞产生的生长因子可能有助于减少肠道损伤，同时促进肠道修复。我们假设：1）肿瘤坏死因子（TNF）、脂多糖（LPS）或缺氧会改变骨髓间充质干细胞（BMSC）的TNF、胰岛素样生长因子-1（IGF-1）、白细胞介素-6（IL-6）和血管内皮生长因子（VEGF）的产生；2）1型肿瘤坏死因子受体（TNFR1）或2型肿瘤坏死因子受体（TNFR2）的缺失会导致细胞因子和生长因子产生模式的改变。从雌性野生型（WT）、TNFR1基因敲除（KO）和TNFR2基因敲除小鼠中获取骨髓间充质干细胞。用TNF、LPS或缺氧刺激细胞。24小时后，通过酶联免疫吸附测定法（ELISA）检测细胞上清液。无论使用何种刺激，与野生型相比，两种基因敲除小鼠中TNF和IGF-1的产生均减少，而IL-6和VEGF水平似乎受活化的肿瘤坏死因子受体和初始刺激的共同调节。TNF刺激后，两种基因敲除小鼠中的IL-6均比野生型增加，但LPS刺激后则显著降低。与野生型相比，缺氧使TNFR1基因敲除细胞中的IL-6增加，但TNFR2基因敲除细胞中未增加。TNF刺激使TNFR2基因敲除细胞中的VEGF减少，而与野生型相比，TNFR1基因敲除导致VEGF无变化。与野生型相比，LPS刺激后TNFR1基因敲除使VEGF减少；TNFR2基因敲除细胞中未观察到变化。缺氧时，与野生型相比，TNFR1基因敲除细胞表达更多的VEGF，而野生型和TNFR2基因敲除细胞之间未观察到差异。肿瘤坏死因子受体基因敲除会改变骨髓间充质干细胞细胞因子的产生。确定产生所需生长因子的合适刺激和信号级联反应可能有助于最大限度地发挥干细胞的治疗潜力。
