I received my PhD from the University of Illinois under the Reproductive Biology Training Program. In this program there is considerable interaction and discussion among the students and faculty with a wide range of research focuses. The RBTP faculty encourages students to be very questioning, form their own hypotheses, design their own experiments, and write their own proposals. My coursework was concentrated on reproductive physiology but also included biochemistry and cell biology, developmental biology, genetics, microbiology, and research ethics. Prior to my PhD I was fortunate to work in three highly regarded laboratories with research focuses ranging from molecular biology to population genetics to Pathology. In 2003 I received brief postdoctoral training in basic electrophysiology. I took a break from research between 2004 and 2009 to raise two children. During this time I kept current with the scientific literature and contributed to work investigating the role of the alpha 7 integrin in placental development and embryonic vascularization in my spare time. I have missed research very much and am highly motivated to return. I have recently begun working with Dr. Iain Buxton. Dr. Buxton is a highly successful scientist with a long track record of research in uterine function during pregnancy. Dr. Buxton possesses a rare combination of medical knowledge, attention to detail, and vision. Our discussions stimulated the ideas presented in this proposal and I cannot think of a better mentor for this project. The faculty here at the University of Nevada School of Medicine is widely recognized for their expertise in smooth muscle physiology. Their knowledge of smooth muscle physiology is the perfect complement for my background in molecular and cellular biology and the physiology of reproduction. During the mentored phase of this award I will learn new experimental skills in muscle mechanics and electrophysiology that will provide exciting results for the huge problem of preterm labor. Therefore, the University of Nevada is an ideal institution in which to further my career goals to become an independent researcher. My comprehensive training in Reproductive Physiology combined with extensive training in molecular biology, cellular biochemistry, and more recently smooth muscle mechanics have uniquely prepared me to investigate the exciting and highly relevant topic of integrin action during human preterm and post-term labor. In the longer term I would like to obtain a faculty appointment and to direct basic research that will lead to a better understanding of preterm labor and how to prevent it. This award would allow me to move from a postdoctoral position to a faculty appointment. I hope to gain further insights into the regulation of labor induction at the molecular level. An appointment in the Pharmacology Department here at the medical school would ideally situate me to identify pharmacological agents to halt preterm labor. During pregnancy the onset of labor is dependent on activation of the uterine myometrium from the quiescent to the contractile state. The initiation of uterine contractions requires the activation of both endocrine and stretch-induced signaling pathways. The molecular mechanisms underlying the stretch-induced pathway are just beginning to be elucidated, however recent data have shown that Focal Adhesion Kinase (FAK) is activated in term human myometrial tissue, a strong indicator of integrin engagement (Li et al., 2009). Activation of the FAK-ERK pathway strongly suggests integrin receptor engagement is required for myometrial contraction. Because integrins have been shown to play pivotal roles in smooth muscle contractility, I hypothesize at least one integrin heterodimer will be essential to myometrial contractility. I will determine which integrin subunits are present and/or upregulated in term pregnant human myometrium and determine if individual integrin subunits regulate stretch-induced contraction in human uterine tissue. I will create an inducible mouse model in which integrin 21 production can be blocked in the uterine myometrium during pregnancy. I will use these mice to determine if loss of 21 integrin decreases myometrial contractility in response to stretch in vitro, alters downstream signaling pathways, or results in post-term labor. I will also test the hypothesis that enhanced integrin-ERK activation in the uterus contributes to preterm labor. I will compare the expression of relevant integrins in tissue sections from pre-term and post-term human uterus compared to term uterus and determine if downstream FAK-ERK activation is altered in pre-term and post-term human myometrium. Defining the integrin- mediated signaling pathways that regulate stretch induced activation of the uterine myometrium will have important implications for treating preterm and post term labor.
During pregnancy the onset of labor depends on the initiation of uterine contractions. This study will determine if integrin proteins control uterine contraction and if these proteins are altered in cases of preterm labor or in post-term pregnancies.