David Han, Ph.D.Associate Professor, Department of Cell Biology
Center for Vascular Biology
|B.S.||Western Illinois University||Biology|
|Ph.D.||George Washington University||Genetics|
We are currently working on three areas: The first project deals with the process of recognition and engulfment of apoptotic cells. In terms of the basic biology of this process, we are interested in identification of ligands that coat apoptotic cells, receptors that recognize these ligands, signaling in apoptotic cells that mediate externalization of the ligands, and signaling in engulfing cells that mediate internalization and digestion of apoptotic cells. To address the pathophysiological consequences of this process in vivo, we are interested in developing and characterizing animal models in which ligands and receptor genes have been deleted. This project is currently funded by the American Heart Association. We are seeking additional funding from NIH to support this project. The second project deals with pluripotency of human embryonic stem cells and iPS cells. Using a phosphoproteomic approach, we are interested in identification of signaling pathways that are operational in pluripotent stem cells and changes in these cells when they begin to assume differentiated phenotype. This project is currently funded by the Connecticut State Stem Cell Initiative. We are seeking additional funding from NIH to support this project. The third project deals with biomarker discovery in human diseases such as cancer, cardiovascular disease, and multiple sclerosis. A number of proteomic studies in human disease tissues have been carried out with the overall goals to (1) identify biomarkers of human diseases, (2) uncover mechanisms of pathogenesis, and (3) provide new insights to treat human diseases. We are currently seeking funding from NIH and other sources to support these projects.
Not Accepting Students for Lab Rotations at This Time
Lab Rotation Projects Proteomics and Protein: Protein Interaction Networks Students who wish to understand the basic techniques related to proteomics and want to learn how to use proteomics to understand biologically relevant protein : protein interaction networks can participate in a rotation project. #1 – Annexin I interacting proteins: We have recently showed that Annexin I protein is crucial for the recognition and engulfment of apoptotic cells. We have a good antibody that can be used to immunoprecipitate Annexin I and associated protein complexes. Students will participate in immunoprecipitation of endogenous Annexin I from viable cells or apoptotic cells to identify the proteins that co-precipitate with annexin I. Students are anticipated to learn basic protein identification technique using the liquid-chromatography and tandem mass spectrometry. #2 - Phosphotidylserine Receptor interacting protein networks: We have also showed that Phosphatidylserine Receptor (PSR) participates in the engulfment of apoptotic cells by recognizing cell-surface exposed annexin I. Thus, we are interested in identifying PSR associated proteins during the engulfment of apoptotic cells. Students will participate in PSR immunoprecipitation experiments and identification of cell surface receptors and intracellular signaling proteins. #3- Cancer Biology Projects: We are interested in identifying cancer specific oncoproteins / tumor suppressor protein from histological tissue arrays. We have recently developed methods to dientify proteins directly from human prostate cancer tissues. Students will participate in optimizing the protein extraction conditions to detect low quantity of proteins from tumor cells using very sensitive mass spectrometry and proteomics technologies. At the end of the rotation, students are expected to learn a number of techniques related to proteomics and cancer biology.