Gp6, encoding the platelet-specific collagen receptor GPVI, is crucial for platelet activation, adhesion, and aggregation. It plays a significant role in the thrombotic pathway, and its expression during megakaryocytic differentiation is regulated by CpG demethylation initiated by thrombopoietin [4].

In a study on Itga2-Gp6-double collagen receptor deficient mice, the deficiency of both Gp6 and Itga2 had no impact on platelet number and GPVI responsiveness. Megakaryocyte count, size, localization, maturation, and association to sinusoids were normal, but the contact of megakaryocytes to collagen type I filaments was decreased at sinusoids compared to wild-type mice [2]. In human studies, genetic variations in the GP6 regulatory region are associated with platelet hyperaggregability, which may be a cause of miscarriage [1]. Also, certain SNPs in GP6 are associated with an increased risk of venous thromboembolism in patients with sticky platelet syndrome [5], and some SNPs in GP6 are related to the risk of non-fatal myocardial infarction in Caucasians [3].

In conclusion, Gp6 is essential for platelet-related functions. Research using gene-knockout mouse models, like the Itga2-Gp6-double deficient mice, helps to understand its role in megakaryocyte-platelet-collagen interactions. In human studies, the association of Gp6 genetic variations with diseases such as miscarriage, venous thromboembolism, and non-fatal myocardial infarction emphasizes its significance in thrombotic-related disease areas.

References:

1. Sokol, Juraj, Skerenova, Maria, Biringer, Kamil, Stasko, Jan, Kubisz, Peter. 2015. Genetic variations of the GP6 regulatory region in patients with sticky platelet syndrome and miscarriage. In Expert review of hematology, 8, 863-8. doi:10.1586/17474086.2015.1083417. https://pubmed.ncbi.nlm.nih.gov/26308704/

2. Semeniak, Daniela, Faber, Kristina, Öftering, Patricia, Manukjan, Georgi, Schulze, Harald. 2019. Impact of Itga2-Gp6-double collagen receptor deficient mice for bone marrow megakaryocytes and platelets. In PloS one, 14, e0216839. doi:10.1371/journal.pone.0216839. https://pubmed.ncbi.nlm.nih.gov/31398205/

3. Shaffer, J R, Kammerer, C M, Dorn, J, Trevisan, M, Donahue, R P. 2010. Polymorphisms in the platelet-specific collagen receptor GP6 are associated with risk of nonfatal myocardial infarction in Caucasians. In Nutrition, metabolism, and cardiovascular diseases : NMCD, 21, 546-52. doi:10.1016/j.numecd.2009.12.002. https://pubmed.ncbi.nlm.nih.gov/20227257/

4. Kanaji, Sachiko, Kanaji, Taisuke, Jacquelin, Beatrice, Izuhara, Kenji, Kunicki, Thomas J. 2005. Thrombopoietin initiates demethylation-based transcription of GP6 during megakaryocyte differentiation. In Blood, 105, 3888-92. doi:. https://pubmed.ncbi.nlm.nih.gov/15701720/

5. Kotuličová, Daniela, Chudý, Peter, Škereňová, Mária, Dobrotová, Miroslava, Kubisz, Peter. . Variability of GP6 gene in patients with sticky platelet syndrome and deep venous thrombosis and/or pulmonary embolism. In Blood coagulation & fibrinolysis : an international journal in haemostasis and thrombosis, 23, 543-7. doi:10.1097/MBC.0b013e328355a808. https://pubmed.ncbi.nlm.nih.gov/22821001/