2018 Fiscal Year Research-status Report
Platelet activation plays a repulsive role of lymphatic to blood vessels in mouse peripheral tissues
| Project/Area Number |
18K15005
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| Research Institution | Kobe University |
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Principal Investigator |
劉 シンイ 神戸大学, 医学研究科, 教育研究補佐員 (40813928)
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| Project Period (FY) |
2018-04-01 – 2020-03-31
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| Keywords | mouse / lymphatic / development |
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| Outline of Annual Research Achievements |
Lymphatic endothelial cells are derived from venous endothelial cells during embryonic development. Previous study suggested a discrete role of platelet mediated blood-lymph separation in lymph-venous junctions. However, how platelet keep lymphatic vessels separate from blood vessels remains unknown. In this study, I confirmed abnormal blood filled in lymphatic vessels in the embryonic back skin of Plcg knockout mice. Result showed blood filled lymphatic vessels in the peripheral tissue but where was the misconnection site still unclear. To address this question, I performed fluorescent angiography of isolectin GS-IB4 injection through embryonic blood circulation around embryonic day (E) 14.5 or 15.5. Results revealed that part of isolectin-positive lymphatic vessels in embryonic peripheral tissue, indicating Plcg2 knockout embryos exhibit abnormal directional blood flow into lymphatic vessels through peripheral lymph-blood misconnection sites.
I also detected isolated blood-filled lymphatic islands in Aspp1; Plcg2 double knockout mouse embryonic peripheral tissues around E15.5. Moreover, fluorescent isolectin injection into embryonic blood circulation showed both isolectin-positive and negative signal expressed in a length of lymphatic vessel. I also observed a blood capillary protrusion oriented toward this lymphatic vessel at this site. This result indicated that isoletcin localized one blood-lymph misconnection site by blood circulation. Overall, by using this method I identified a novel role for platelets in partitioning blood and lymphatic vascular compartments.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
Last year I analyzed Aspp1 knockout, Plcg2 knockout and Aspp1; Plcg2 double knockout embryonic phenotype at different stage. I find direct evidence and confirmed our original hypothesis: platelet plays a key role in separation of blood and lymphatic vessels in mice peripheral tissue.
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| Strategy for Future Research Activity |
My study also suggests that platelet plays a repulsive guidance role in separation of blood and lymphatic vessels in the peripheral tissue. In the following year, to understand this important guidance cue in cellular events, I will use Semaphorin 3G (Sema3G), which showed a dramatic repulsive role from artery to lymphatic endothelial cells, to generate Sema3G, Plcg2 double knockout mice. By using these mice, I will try to detect whether abnormal misconnection sites will happen between artery and lymphatic vessels. I will also establish a co-culture system of ES cells with distinct expression of Sema3G, Plcg2 or not.
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| Causes of Carryover |
Supplies expenses for antibodies, chemicals, laboratory wares, and experimental animals will be required to perform experiments in this study.
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Research Products
(2 results)
