Co-localization of Urokinase and its Receptor on Established Human Umbilical Vein Endothelial Cell.
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- Ueshima Shigeru
- Department of Physiology, Kinki University School of Medicine, Osakasayama, Osaka 589-8511, Japan
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- Matsumoto Hiroshi
- Department of Physiology, Kinki University School of Medicine, Osakasayama, Osaka 589-8511, Japan
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- Izaki Seiichi
- Department of Dermatology, Saitama Medical Center, Saitama Medical School, Kawagoe, Saitama 350-8550, Japan
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- Mitsui Youji
- National Institute of Bioscience and Human-Technology, Agency of Industrial Science and Technology, Tsukuba, Ibaraki 305-8566 Japan
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- Fukao Hideharu
- Department of Physiology, Kinki University School of Medicine, Osakasayama, Osaka 589-8511, Japan
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- Okada Kiyotaka
- Department of Physiology, Kinki University School of Medicine, Osakasayama, Osaka 589-8511, Japan
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- Matsuo Osamu
- Department of Physiology, Kinki University School of Medicine, Osakasayama, Osaka 589-8511, Japan
Abstract
Vascular endothelial cells possess antithrombotic properties, which are determined by the balance between plasminogen activators (PAs) and PA inhibitors (PAIs). A cell line, TKM-33, has been established and cloned from human umbilical vein endothelial cells, was previously reported to produce a large amount of urokinase-type PA (u-PA) and small amounts of tissue-type plasminogen activator (t-PA) and PA inhibitor-1 (PAI-1). Moreover, TKM-33 expressed the u-PA receptor (u-PAR) which plays an important role in the localization of fibrinolytic activity on cell surface. In the present study, we investigated the localization of u-PA, t-PA, PAI-1 and u-PAR in TKM-33 by using immunofluorescence staining technique. The endothelial cells were strongly stained with anti-PAI-1, anti-u-PA and anti-u-PAR IgGs, and slightly with anti-t-PA IgG. The double immunofluorescence staining with mouse anti-u-PA IgG and rabbit anti-u-PAR IgG followed by rhodamine-conjugated anti-mouse IgG and FITC-conjugated anti-rabbit IgG showed the co-localization of u-PA and u-PAR on the same section of endothelial cells. Although u-PA antigen also existed in the cytoplasm of endothelial cells, u-PAR antigen did not. The treatment of endothelial cells with phorbol-myristateacetate (PMA) upregulated the expression of u-PA and u-PAR antigens. In this stimulation, u-PAR antigen was detected not only on the surface of the cells but also in the cytoplasm. Thus, the binding of u-PA to u-PAR was confirmed by double immunofluorescence staining.
Journal
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- Cell Structure and Function
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Cell Structure and Function 24 (2), 71-78, 1999
Japan Society for Cell Biology
