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Retroviral Infection of Murine Embryonic Stem Cell Derived Embryoid Body Cells for Analysis of Hematopoietic Differentiation

Embryonic stem cells (ESCs) are an outstanding model for elucidating the molecular mechanisms of cellular differentiation. They are especially useful for ...

University of Notre Dame

Several small (<25aa) peptides have been designed based on the sequence of the dentin phosphoprotein, one of the major noncollagenous proteins thought to be involved in the mineralization of the dentin extracellular matrix during tooth development. These peptides, consisting of multiple repeats of the tripeptide aspartate-serine-serine (DSS), bind with high affinity to calcium phosphate compounds and, when immobilized, can recruit calcium phosphate to peptide-derivatized polystyrene beads or to demineralized human dentin surfaces. The affinity of binding to hydroxyapatite surfaces increases with the number of (DSS)(n) repeats, and though similar repeated sequences-(NTT)(n), (DTT)(n), (ETT)(n), (NSS)(n), (ESS)(n), (DAA)(n), (ASS)(n), and (NAA)(n)-also showed HA binding activity, it was generally not at the same level as the natural sequence. Binding of the (DSS)(n) peptides to sectioned human teeth was shown to be tissue-specific, with high levels of binding to the mantle dentin, lower levels of binding to the circumpulpal dentin, and little or no binding to healthy enamel. Phosphorylation of the serines of these peptides was found to affect the avidity, but not the affinity, of binding. The potential utility of these peptides in the detection of carious lesions, the delivery of therapeutic compounds to mineralized tissues, and the modulation of remineralization is discussed.

Specific binding and mineralization of calcified surfaces by small peptides.

There is increasing evidence for emotional fit in couples and groups, but also within cultures. In the current research, we investigated the consequences of emotional fit at the cultural level. Given that emotions reflect people's view on the world, and that shared views are associated with good social relationships, we expected that an individual's fit to the average cultural patterns of emotion would be associated with relational well-being. Using an implicit measure of cultural fit of emotions, we found across 3 different cultural contexts (United States, Belgium, and Korea) that (1) individuals' emotional fit is associated with their level of relational well-being, and that (2) the link between emotional fit and relational well-being is particularly strong when emotional fit is measured for situations pertaining to relationships (rather than for situations that are self-focused). Together, the current studies suggest that people may benefit from emotionally "fitting in" to their culture.

Emotional fit with culture: a predictor of individual differences in relational well-being.

Cell-cell fusion is an evolutionarily conserved process that leads to the formation of multinucleated myofibers, syncytiotrophoblasts and osteoclasts, allowing their respective functions. Although cell-cell fusion requires the presence of fusogenic membrane proteins and actin-dependent cytoskeletal reorganization, the precise machinery allowing cells to fuse is still poorly understood. Using an inducible knockout mouse model to generate dynamin 1- and 2-deficient primary osteoclast precursors and myoblasts, we found that fusion of both cell types requires dynamin. Osteoclast and myoblast cell-cell fusion involves the formation of actin-rich protrusions closely associated with clathrin-mediated endocytosis in the apposed cell. Furthermore, impairing endocytosis independently of dynamin also prevented cell-cell fusion. Since dynamin is involved in both the formation of actin-rich structures and in endocytosis, our results indicate that dynamin function is central to the osteoclast precursors and myoblasts fusion process, and point to an important role of endocytosis in cell-cell fusion.

Hyewon Choi

Department of Biological Sciences

University of Notre Dame

Retroviral Infection of Murine Embryonic Stem Cell Derived Embryoid Body Cells for Analysis of Hematopoietic Differentiation

Hyewon Choi

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Department of Biological Sciences

University of Notre Dame

Retroviral Infection of Murine Embryonic Stem Cell Derived Embryoid Body Cells for Analysis of Hematopoietic Differentiation

Department of Biological Sciences