Ann Sutherland Assistant Professor of Cell Biology Phone: (434)243-6711 Fax: (434)982-5626 Office: Unknown Email: as9n@virginia.edu Homepage: Click Here

Research Interest

CELL MATRIX INTERACTIONS IN MOUSE DEVELOPMENT

Interactions between cells and their surrounding extracellular matrix (ECM) influence many aspects of cell behavior, including adhesion, protrusive activity and migration, and can also affect patterns of gene expression and thus, cell differentiation. My long term goal is to understand the role of cell-matrix interactions in regulating cell behavior and differentiation during development of the mouse embryo. I am focussing in particular on trophoblast differentiation during mouse embryo implantation into the uterus, which involves a series of regulated adhesive interactions.

Just prior to implantation the trophectoderm cells of the blastocyst become adherent to ECM and differentiate from a quiescent epithelium to an invasive cell type, allowing the embryo to attach and penetrate the uterine stroma, ultimately forming the placenta. Cell-ECM interactions are important for the initial differentiation: blastocysts will only attach and differentiate when provided with ECM substrates. Experiments using function-blocking antibodies to the integrin family of ECM receptors show that integrin receptors mediate trophoblast attachment to a variety of ECM molecules. Using PCR, immunoprecipitation and immunofluorescence assays, I have determined that changes in integrin expression and distribution accompany trophoblast differentiation and invasion, and that expression of several of these receptors is trophoblast-specific at the time of implantation.

Figure 1:
Immunofluorescent detection of integrins 6 1 (right) and v 3 (left) on the cell surface of the blastomeres of the 2-cell mouse embryo.

I am pursuing these observations in several ways: first by analyzing the promoter regions of two trophoblast-specific integrin genes; secondly, by testing the regulation of trophoblast invasive behavior using reagents that influence differentiation, and finally by misexpressing mutant forms of potential regulatory molecules in blastocysts using recombinant adenovirus and using time-lapse video to analyze the effects on cell behavior.

Figure 2:
Polymerase chain reaction (PCR) analysis of integrin subunit expression in embryos at the 2-cell (2C), 8-cell (8C), early blastocyst (EB) and late blastocyst (LB) stages of preimplantation development, and in embryo outgrowths (OG) and the embryonic (E) and trophoblast (EPC) regions of the E7.5 embryo.

Representative Recent Publications

1. Sutherland, A.E., P.G. Calarco, and C.H. Damsky (1988).Expression and function of cell surface extracellular matrix receptors in mouse blastocyst attachment and outgrowth. J. Cell Biol. 106: 1331-1348.
2. Sutherland, A.E., R. Sanderson, M. Mayes, M. Seibert, P.G. Calarco, M. Bernfield, and C.H. Damsky (1991). Expression of syndecan, a putative low affinity fibroblast growth factor receptor, in the early mouse embryo. Development 113: 339-351.
3. Sutherland, A.E., P.G. Calarco, and C.H. Damsky (1993). Developmental regulation of integrin expression at the time of implantation in the mouse embryo. Development 119: 1175-1186.
4. Almeida, E.A.C., A.-P.J. Huovila, A.E. Sutherland, L.E. Stephens, P.G. Calarco, L.M. Shaw, A.M. Mercurio, A. Sonnenberg, P. Primakoff, D.G. Myles, and J.M. White (1995). Mouse egg integrin alpha-6 beta-1 functions as a sperm receptor. Cell 81: 1-10.
5. Stephens, L.E., A.E. Sutherland, I.V. Klimanskaya, A. Andrieux, J. Meneses, R.A. Pedersen, and C.H. Damsky (1995). Deletion of beta-1 integrins in mice results in inner cell mass failure and periimplantation lethality. Genes Dev. 9: 1883-1895.
6. Yao, C.-C., B.L. Ziober, A.E. Sutherland, D.L. Mendrick and R.H. Kramer (1996). Laminins promote the locomotion of skeletal myoblasts via the alpha 7 integrin receptor. J. Cell Sci. 109: 3139-3150.
7. Parast, M.M., S.E. Aeder and A.E. Sutherland (2001). Trophoblast giant
   cell differentiation involves changes in cytoskeleton and cell motility.
   Dev. Biol. 230: 43-60.
8. Periasamy, A., C. Noakes, R. Keller, P. Skoglund and A.E. Sutherland
   (2001). Two-photon excitation and digital deconvolution microscopy in
   Xenopus and transgenic mouse embryos. In: Confocal and Two-photon
   Microscopy: Foundations, Applications and Advances (A. Diaspro, ed.).
   Wiley-Liss, Inc, New York.
9. Klaffky, E.J., R.G. Williams, C.C. Yao, B.Ziober, R. Kramer and A.E.
   Sutherland (2001). Trophoblast specific expression and function of the
   integrin alpha 7 subunit in the peri-implantation mouse embryo. (in press
   in Developmental Biology).
10. Martin, P.M. and A.E. Sutherland (2001). Exogenous amino acids reglate
    trophectoderm differentiation in the mose blastocyst throgh an
    mTOR-dependent pathway. (in press in Developmental Biology)
    

For more information email as9n@virginia.edu.