Description of Research Expertise

Dr. Song's research pertains to vascular and autoimmune disease biology of membrane complement regulatory proteins. Complement is a form of natural immunity that plays an essential role in host defense. However, activated complement must be carefully regulated to avoid autologous tissue damage. Prevention of autologous complement attack is in part achieved by specific membrane regulatory proteins on the cell surface. Decay-accelerating factor (DAF, CD55) and CD59 are two key membrane complement regulatory proteins on mammalian cells. The roles of CD55 and CD59 in preventing complement-mediated vascular injury and autoimmune end organ damage are being investigated in our laboratory using single and double knockout mice that are deficient in CD55 or/and CD59.

Dr. Song is also investigating the ole of estrogen metabolism in intracrine and paracrine estrogen regulation. Elicitation of biological responses by estrogen in target tissues requires the presence of estrogen receptor as well as receptor-active ligand in the local microenvironment. While much attention has been devoted to the study of the receptors in estrogen target tissues, the concept is emerging that tissue estrogen sensitivity may also be regulated by ligand availability through metabolic transformation in situ. Estrogen sulfotransferase catalyzes the specific sulfoconjugation and inactivation of estrogen and is expressed in a number of estrogen target tissues. Using a knockout mouse that is deficient in the estrogen sulfotransferase gene, we are studying the physiological role of estrogen sulfation in intracrine and paracrine estrogen regulation.