Effects of Actr2 gene Variants on Mouse Viability, Gene Expression, and Cytoskeletal Dynamics
| Autor: | Guojing Zhu, Amy E Siebert, Marisa A Brake, Alexander J Johnston, Cleuren Audrey, Randal J. Westrick, Linzi M Hobbs, Vakharia Paras |
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| Rok vydání: | 2019 |
| Předmět: | |
| Zdroj: | Blood. 134:2340-2340 |
| ISSN: | 1528-0020 0006-4971 |
| DOI: | 10.1182/blood-2019-131004 |
| Popis: | Venous thromboembolism (VTE) is a prevalent human disease that exhibits significant heritability. Factor V Leiden (F5L) is the most common known VTE risk factor, but modifier genes significantly influence VTE development. We recently identified a p.R258G missense mutation in the Actr2 gene (Actr2+/G, ARP2 protein) as a genetic suppressor of lethal thrombosis in mice homozygous for F5L (F5L/L) and hemizygous for tissue factor pathway inhibitor (Tfpi+/-). However, the antithrombotic mechanism of Actr2+/G is unknown. We used genetic and genomic techniques to investigate the phenotypic effects of the Actr2G variant on cells and mice. We previously analyzed progeny from Actr2+/G x Actr2+/G (N7 backcross generations to C57BL6/J) to investigate the effects of Actr2G on mouse survival. The progeny deviated from Mendelian frequencies, as only ~12% were Actr2G/G mice (N=303; p We next studied the mechanism(s) of Actr2G thrombosis suppression by gene expression studies. RT-qPCR for multiple coagulation genes was performed in liver samples from Actr2+/+ and Actr2+/G mice. Serpine2 mRNA (Protease Nexin-1 (PN-1)) was significantly increased in Actr2+/G mice (N=3; p To further investigate the effects of the Actr2G mutation, we isolated mouse embryonic fibroblasts (MEFs) from Actr2+/+ and Actr2G/G mice. The Actr2G/G MEFs grew poorly in culture, and displayed a significant reduction in cell surface area 20 minutes after plating on fibronectin when compared to Actr2+/+ (q=0.0003). Further analysis revealed F-actin aggregation in the root of cellular protrusions of Actr2G/G MEFs. These results indicate cytoskeletal remodeling defects in Actr2G/G cells. In summary, our studies indicate that mutations affecting ARP2 function can have profound effects on mouse and cell survival, as well as pronounced effects on specific physiological processes like blood coagulation and the transcriptional regulation of coagulation related genes. Disclosures No relevant conflicts of interest to declare. |
| Databáze: | OpenAIRE |
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