Lin Xia1, Zhaogang Dong2, Yun Zhang3, Xiaoying Zhang3, Xiaobin Song3, Mingxia Sun3, Yingwei Hu3, Shaohua Liu3, Ketao Wang3, Xun Qu2, Fengcai Wei3. 1. Department of Stomatology, Qilu Hospital, and Institute of Stomatology, Shandong University, Jinan, PR China; Department of Stomatology, Shuguang Branch of Shanghai Baoshan Hospital, Shanghai, PR China. 2. Institute of Basic Medical Sciences and Key Laboratory of Cardiovascular Proteomics in Shandong Province, Qilu Hospital, Shandong University, Jinan, PR China. 3. Department of Stomatology, Qilu Hospital, and Institute of Stomatology, Shandong University, Jinan, PR China.
Abstract
BACKGROUND/ PURPOSE: Soluble vascular endothelial growth factor receptor-1 (sVEGFR1) antagonizes angiogenesis by inhibiting the biological function of vascular endothelial growth factor (VEGF). Immature dendritic cells (imDCs) express high levels of sVEGFR1 during development and are antiangiogenic. This study aimed to investigate the changes in VEGFR1, sVEGFR1, and VEGF levels during the development of imDCs and explore the underlying signaling mechanisms. METHODS: To model the differentiation of imDCs from monocytes, RAW264.7 cells, a murine monocyte/macrophage cell line, were stimulated by interleukin-4 (IL-4; 10 ng/mL, 20 ng/mL, and 40 ng/mL) and/or by granulocyte-macrophage colony-stimulating factor (GM-CSF; 10 ng/mL, 20 ng/mL, and 50 ng/mL) and/or pretreated by the p38 inhibitor SB203580. The levels of VEGFR1, sVEGFR1, and VEGF were detected by reverse transcription polymerase chain reaction (RT-PCR), Western blot, and enzyme-linked immunosorbent assay (ELISA). RESULTS: IL-4 increased the VEGFR1 mRNA and sVEGFR1 levels in RAW264.7 (p < 0.05). This increase was inhibited by SB203580. Granulocyte-macrophage colony-stimulating factor increased the sVEGFR1 levels, but it had no significant effect on VEGFR1 mRNA levels. SB203580 decreased the expression of VEGFR1 mRNA induced by GM-CSF, whereas sVEGFR1 was unaffected. IL-4 had a greater effect on sVEGFR1 levels, compared to GM-CSF. CONCLUSION: IL-4 and GM-CSF increased sVEGFR1 levels, but did not significantly effect VEGF expression, and led to the antiangiogenesis properties of monocytes. p38 Mitogen-activated protein kinase signaling has an important role in the process.
BACKGROUND/ PURPOSE: Soluble vascular endothelial growth factor receptor-1 (sVEGFR1) antagonizes angiogenesis by inhibiting the biological function of vascular endothelial growth factor (VEGF). Immature dendritic cells (imDCs) express high levels of sVEGFR1 during development and are antiangiogenic. This study aimed to investigate the changes in VEGFR1, sVEGFR1, and VEGF levels during the development of imDCs and explore the underlying signaling mechanisms. METHODS: To model the differentiation of imDCs from monocytes, RAW264.7 cells, a murine monocyte/macrophage cell line, were stimulated by interleukin-4 (IL-4; 10 ng/mL, 20 ng/mL, and 40 ng/mL) and/or by granulocyte-macrophage colony-stimulating factor (GM-CSF; 10 ng/mL, 20 ng/mL, and 50 ng/mL) and/or pretreated by the p38 inhibitor SB203580. The levels of VEGFR1, sVEGFR1, and VEGF were detected by reverse transcription polymerase chain reaction (RT-PCR), Western blot, and enzyme-linked immunosorbent assay (ELISA). RESULTS:IL-4 increased the VEGFR1 mRNA and sVEGFR1 levels in RAW264.7 (p < 0.05). This increase was inhibited by SB203580. Granulocyte-macrophage colony-stimulating factor increased the sVEGFR1 levels, but it had no significant effect on VEGFR1 mRNA levels. SB203580 decreased the expression of VEGFR1 mRNA induced by GM-CSF, whereas sVEGFR1 was unaffected. IL-4 had a greater effect on sVEGFR1 levels, compared to GM-CSF. CONCLUSION:IL-4 and GM-CSF increased sVEGFR1 levels, but did not significantly effect VEGF expression, and led to the antiangiogenesis properties of monocytes. p38 Mitogen-activated protein kinase signaling has an important role in the process.