Nonmuscle myosin 2A (NM2A) not only plays numerous and diverse roles in vertebrate development, but also functions as a negative regulator for the formation of squamous cell carcinoma (SSC). Our previous research reported that ablation of NM 2A in mice (A-/A-) led to the abnormal formation of the visceral endoderm and embryonic lethality by E6.5. However, the molecular mechanisms responsible for A-/A- embryonic death were not fully characterized. Since in vitro differentiation of embryonic stem cells (ESCs) has been shown to faithfully mimic early embryonic development in vivo, we first established a mouse ESC differentiation system, including a spontaneous differentiation system (embryonic body formation) and a hematopoietic differentiation system (embryonic body formation with enhanced hematopoietic differentiation). Under spontaneous differentiation, a gene ontology analysis of down-regulated genes according to biological processes showed that NM 2A-/- ESCs has a developmental deficiency related to ear development, immune system development, vasculature development, hematopoietic or lymphoid organ development, and embryo implantation. RT-qPCR analysis revealed that NM 2A deletion decreased mesendoderm gene expression (Mesp1, Mixl1, T gene and Eomes). In addition, compared to four week old control teratomas, NM 2A knockout teratomas exhibited a low level of endoderm genes, such as Sox17, HNF4a, and AFP. Gene ontology analyses also showed that the top two downregulated biological processes in NM 2A-/A- ESCs are chromatin organization and chromatin modification. Compared to wild type, the levels of tri-methylation of K4, K9 and K27 on histone H3 were significantly decreased during differentiation. These data indicate that there is a difference in chromatin structures between the wild-type and the A-/A- ESCs in development. Defects in hematopoietic development are further confirmed in a hematopoietic differentiation system where NM 2A deletion decreased the percentage of hemangioblast cells (Flk1+ VE-Cad-) and hematopoietic progenitors (CD41+ CD45-). Interestingly, an inhibitor of the lysine demethylase 5 family (CPI-455) could rescue the defects in hematopoietic development caused by NM 2A deletion. The KDM 5 family contains 4 members including KDM 5A, KDM 5B, KDM 5C and KDM 5D. Knock down of KDM 5A could rescue the hematopoietic development defects caused by NM 2A deletion. These data indicate that KDM5A-mediated histone demethylation is critically involved in hematopoietic development defects caused by NM 2A deletion. Overall, these data indicate that deletion of NM 2A results in major defects related to chromatin modification and organization that consequently affects ESC differentiation including hematopoietic or lymphoid organ development.

Project Start
Project End
Budget Start
Budget End
Support Year
28
Fiscal Year
2018
Total Cost
Indirect Cost
Name
U.S. National Heart Lung and Blood Inst
Department
Type
DUNS #
City
State
Country
Zip Code
Baird, Michelle A; Billington, Neil; Wang, Aibing et al. (2017) Local pulsatile contractions are an intrinsic property of the myosin 2A motor in the cortical cytoskeleton of adherent cells. Mol Biol Cell 28:240-251
Naydenov, Nayden G; Feygin, Alex; Wang, Dongdong et al. (2016) Nonmuscle Myosin IIA Regulates Intestinal Epithelial Barrier in vivo and Plays a Protective Role During Experimental Colitis. Sci Rep 6:24161
Conti, Mary Anne; Saleh, Anthony D; Brinster, Lauren R et al. (2015) Conditional deletion of nonmuscle myosin II-A in mouse tongue epithelium results in squamous cell carcinoma. Sci Rep 5:14068
Recuenco, Mariam C; Ohmori, Tomoko; Tanigawa, Shunsuke et al. (2015) Nonmuscle Myosin II Regulates the Morphogenesis of Metanephric Mesenchyme-Derived Immature Nephrons. J Am Soc Nephrol 26:1081-91
Kwan, Raymond; Chen, Lu; Looi, Koksun et al. (2015) PKC412 normalizes mutation-related keratin filament disruption and hepatic injury in mice by promoting keratin-myosin binding. Hepatology 62:1858-69
Chandrasekar, Indra; Goeckeler, Zoe M; Turney, Stephen G et al. (2014) Nonmuscle myosin II is a critical regulator of clathrin-mediated endocytosis. Traffic 15:418-32
Crish, James; Conti, Mary Anne; Sakai, Takao et al. (2013) Keratin 5-Cre-driven excision of nonmuscle myosin IIA in early embryo trophectoderm leads to placenta defects and embryonic lethality. Dev Biol 382:136-48
Ebrahim, Seham; Fujita, Tomoki; Millis, Bryan A et al. (2013) NMII forms a contractile transcellular sarcomeric network to regulate apical cell junctions and tissue geometry. Curr Biol 23:731-6
Doyle, Andrew D; Kutys, Matthew L; Conti, Mary Anne et al. (2012) Micro-environmental control of cell migration--myosin IIA is required for efficient migration in fibrillar environments through control of cell adhesion dynamics. J Cell Sci 125:2244-56
Zhang, Yingfan; Conti, Mary Anne; Malide, Daniela et al. (2012) Mouse models of MYH9-related disease: mutations in nonmuscle myosin II-A. Blood 119:238-50

Showing the most recent 10 out of 23 publications