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Matrix metalloproteinase12 facilitated platelet activation by shedding carcinoembryonic antigen related cell adhesion
Jing Wang1, Yujia Ye1, Guoqing Wei1
1Laboratory of Molecular Cardiology, Department of Cardiology, The First Affiliated Hospital of Kunming Medical University, Kunming, PR China.
Abstract:
Platelets express several MMPs that modulate their activation, which in turn regulates thrombosis, but the exact mechanism is unclear. This study evaluated the platelet expression of MMP12 and platelet activation by shedding CEACAM1 mediated by MMP12. Expression of MMP12 was measured by RT-PCR, Western blot (WB), and casein zymography in platelet from whole blood by gel filtration over plateletpheresis. The site of CEACAM1 cleavage by MMP12 was determined by high performance liquid chromatography (HPLC), mass spectrometry, WB and flow cytometry (FCM). Furthermore, the regulation of platelet aggregation, release and adhesion by MMP12-dependent shedding of platelet CEACAM1 was analyzed. We have observed that human platelets express MMP12. In addition, CEACAM1 as enzymatic substrates of MMP12 have also been found in this study. MMP12 can cleave the CEACAM1 exodomain at several sites and generated several short peptides. Among these fragments, one peptide, WYKG was identified, whose cutting sits were S66/W67 and A83/I84. We also found that MMP12 facilitated type I collagen induced platelet aggregation, adhesion and alpha granule secretion. Similarly, one short peptide, WYKG, facilitated type I collagen induced platelet alpha granule secretion. We conclude that platelet express MMP12 may facilitate platelet activation through shedding of CEACAM1.
Insights
Human platelets express MMP12, an enzyme that facilitates platelet activation. MMP12 sheds CEACAM1, promoting platelet aggregation, adhesion, and alpha granule secretion, crucial for thrombosis.
Area of Science:
- Hematology
- Biochemistry
- Molecular Biology
Background:
- Platelets play a key role in thrombosis and hemostasis.
- Matrix metalloproteinases (MMPs) are known to modulate platelet function, but specific mechanisms remain unclear.
Purpose of the Study:
- To investigate the expression of MMP12 in human platelets.
- To determine if MMP12 mediates platelet activation through the shedding of CEACAM1.
Main Methods:
- MMP12 expression analyzed by RT-PCR, Western blot, and zymography.
- CEACAM1 cleavage sites identified using HPLC, mass spectrometry, Western blot, and flow cytometry.
- Platelet aggregation, adhesion, and secretion assays performed.
Main Results:
- Human platelets express functional MMP12.
- CEACAM1 identified as an enzymatic substrate for MMP12, with cleavage generating peptides like WYKG.
- MMP12-dependent CEACAM1 shedding enhances type I collagen-induced platelet aggregation, adhesion, and alpha granule secretion.
Conclusions:
- Platelet MMP12 facilitates platelet activation.
- MMP12-mediated shedding of CEACAM1 is a key mechanism in platelet activation and aggregation.