Abstract:

At sites of human injury, leukocytes fight against invading microorganisms while von Willebrand factor (VWF) facilitates platelets to stop bleeding. The mechanics of leukocytes and VWF is extremely important for their functions. On the one hand, to migrate out of blood vessels and fulfill their defensive functions, leukocytes first roll on the endothelium in the blood vessel. Stable rolling is essential for effective leukocyte recruitment into infected tissues. The rolling of leukocytes is a complex dynamic process that is mediated concertedly by many factors including cellular mechanical properties such as surface protrusion and tether extraction. Surface protrusion is a solid-like behavior of cell membrane when it is subjected to a point force, whereas tether extraction is a fluid-like behavior of cell membrane that follows surface protrusion when the pulling force is large enough. Both surface protrusion and tether extraction facilitate leukocyte rolling on the endothelium by lengthening the lifetime of the adhesive bonds that mediate rolling. On the other hand, to fulfill its function, VWF, a multimer, has to maintain an appropriate size distribution mediated by ADAMTS13, which cleaves VWF in its A2 domain. A force of 20 pN is necessary to unfold the A2 domain, which cannot be cleaved in its globular state.

About the Speaker:

1988年7月毕业于北京大学力学系，获学士学位，免试直升北京大学研究生院；1991年7月毕业于北京大学力学系流体力学专业，获硕士学位；1991年8月至1993年7月在中日友好医院临床医学研究所从事生物流变学研究；1997年5月毕业于美国杜克大学，获机械工程博士学位；1997年6月至1998年9月在杜克大学从事博士后研究并转为助理研究教授；1998年10月至今在美国华盛顿大学（圣路易斯）生物医学工程系任助理教授、副教授（终身），曾任副系主任（2005-2011）、是美国单细胞和单分子生物力学领域的知名学者，在PNAS, Biophysical Journal, Ann. Biomed. Eng. , Am. J. Physiol. Cell Physiol., Physical Review E等国际权威期刊上发表大量论文，目前是Journal of Bioengineering & Biomedical Science、Cellular and Molecular Bioengineering等期刊的编委、副编辑。

校内合作人:覃开蓉, Email: krqin@ Tel: 0411-84709690