Proteomic Analyses Reveal the Role of Progesterone and Inducible Nitric Oxide Synthase in Uterine Remodeling during Pregnancy

In the luteal phase the uterus undergoes a series of changes in uterine proteins and creates a receptive window for embryo attachment. Invasion of implanted embryos into the endometrium initiates both morphological and functional remodeling of pregnant uteri with continuous elevation of progesterone. Rapid development of proteomic analysis offers additional approaches to construct the protein database of pregnant uteri for the study of embryo-induced remodeling. Comparative proteomic studies followed by functional annotation demonstrate the role of progesterone and its downstream molecule (Hoxa10) in regulating the expression of immmunosuppresive proteins (such as glycodelin) and chaperone proteins (such as FK506 binding protein 4). Further improvement in the technology of protein digestion and separation increases the number of myometrial proteins identified. Validation studies indicate a unique expression pattern and functions of inducible nitric oxide synthase during pregnancy. The combinatory effect of inducible nitric oxide synthase and progesterone contributes to decidual remodeling during pregnancy.