Impact of gestation and labor on the expression of the polypeptide hormone, stanniocalcin‐1, in guinea pig and human myometrium

Abstract

Stanniocalcin-1 (STC1) is a small polypeptide hormone which plays a major role in calcium homeostasis. It is involved in physiological processes such as ion transport and reproduction and development. During pregnancy, STC1 production by the ovaries is upregulated and released into circulation. We found that the myometrium is one target of this systemically delivered hormone. The expression of STC1 in the myometrium and its role in labor and dysfunctional labor are unclear. Here we investigate the expression and regulation of STC1 in guinea pig and human myometrium during pregnancy under various physiological conditions. Gene profiling was performed with myometrial RNA obtained from nonpregnant, mid-pregnant (MP), and term-pregnant (TP) guinea pigs and at primary cesarean of human preterm no labor; preterm labor (PTL); term no labor; and term labor (TL). Fold-changes in gene expression were verified by real time pcr. Western blots were used to further determined STC1 protein levels in each myometrial condition. We found a decrease (−9.2 fold) in the gene expression of STC1 in guinea pig myometrium during MP and a contrasting rise (1.7 fold) closer to term. STC1 gene expression increased in human myometrium during normal TL but no change was observed at PTL. STC1 protein levels were greater at term than preterm. These findings suggest that STC1 may be gestationally regulated and important for normal pregnancy outcome. Supported by: HL49041-12 (CPW) and HD049185-01 (CPW)