Junior Recital

List of performers and performances

Junior Recital

List of performers and performances

Collective motion of cells crawling on a substrate: roles of cell shape and contact inhibition

Contact inhibition plays a crucial role in the motility of cells, the process of wound healing, and the formation of tumors. By mimicking the mechanical motion of calls crawling on a substrate using a pseudopod, we constructed a minimal model for migrating cells which gives rise to contact inhibition of locomotion (CIL) naturally. The model cell consists of two disks, one in the front (a pseudopod) and the other one in the back (cell body), connected by a finitely extensible spring. Despite the simplicity of the model, the cells' collective behavior is highly nontrivial, depending on the shape of cells and whether CIL is enabled or not. Cells with a small front circle (i.e. a narrow pseudopod) form immobile colonies. In contrast, cells with a large front circle (i.e. such as a lamellipodium) exhibit coherent migration without any explicit alignment mechanism being present in the model. This suggests that crawling cells often exhibit broad fronts because it helps them avoid clustering. Upon increasing the density, the cells develop density waves which propagate against the direction of cell migration and finally arrest at higher densities

Development of a monoclonal anti-ADAMTS-5 antibody that specifically blocks the interaction with LRP1

The potent aggrecanase ADAMTS-5 is constitutively secreted by chondrocytes, but it is rapidly endocytosed in normal cartilage via the cell surface endocytic receptor LRP1. Therefore it is difficult to detect the total ADAMTS-5 activity produced. In this study, we isolated a monoclonal anti-ADAMTS-5 antibody 1B7 that blocks LRP1-mediated internalization without affecting the aggrecanolytic activity. Addition of 1B7 to cultured human chondrocytes revealed the full aggrecanolytic activity of ADAMTS-5 generated by the cells. 1B7 is a useful tool to estimate the ADAMTS-5 activity and to identify its potential roles in the tissues