The response of the human endometrium to the ovarian hormones, estrogen and progesterone, has been the focus of decades of research. In order to understand this critical aspect of endometrial physiology, we undertook a genome-wide analysis of transcript abundance and changes in transcript level between normal endometrium in the proliferative and secretory phases of the menstrual cycle. A high-density, oligonucleotide gene array, comprising 60 000 gene targets, was used to define the gene expression profile of proliferative and secretory phase endometrium. Results from the arrays were verified using real-time PCR. The expression levels of 149 transcripts differed significantly between the two phases of the cycle determined by stringent range limits (99.99%), calculated using local variance values. These transcripts include previously documented steroidally responsive genes (such as placental protein 14 and stromelysin-3) and novel transcripts not previously linked to either endometrial physiology or steroid regulation (such as intestinal trefoil factor and a number of expressed sequence tags). Examination of the 5' promoter regions of these genes identified many putative estrogen and progesterone receptor DNA binding domains, suggesting a direct response of these genes to the ovarian hormones.

Repair of human endometrium after menstruation and preparation of the endometrium for implantation involves profound angiogenic changes. Vascular endothelial cell growth factor (VEGF) is a recently identified growth factor with significant angiogenic properties. Four species of mRNA encoding VEGFs were identified in human endometrium and myometrium. All species were present throughout the menstrual cycle. Two species, VEGF165 and VEGF121, were present in peripheral leukocytes, indicating tissue-specific splicing of the two other VEGF transcripts. In situ hybridization of mRNA encoding VEGF was not restricted to vascular smooth muscle but was present in epithelial and stromal cells of endometrium throughout the cycle, and the distribution changed during the course of the cycle. All four species of VEGF were expressed by the endometrial carcinoma cell lines Ishikawa, HEC 1-A, and HEC 1-B. Estradiol increased steady-state levels of mRNA encoding VEGF in a dose- and time-dependent manner in HEC 1-A cells. Conditioned medium from these cells possessed angiogenic activity that was depleted by passage through a heparin affinity column. None of the cell lines demonstrated mRNA for acidic or basic fibroblast growth factor (FGF), despite previous reports of the identification of immunoreactive basic FGF in HEC 1-A and HEC 1-B cells. These findings show that VEGFs, not FGFs, are the principal angiogenic growth factors secreted by these cells and that human endometrium expresses a secreted angiogenic growth factor whose site of expression changes during the menstrual cycle.

Lipidomics is of increasing interest in studies of biological systems. However, high-throughput data collection and processing remains non-trivial, making assessment of phenotypes difficult. We describe a platform for surveying the lipid fraction for a range of tissues. These techniques are demonstrated on a set of seven different tissues (serum, brain, heart, kidney, adipose, liver, and vastus lateralis muscle) from post-weaning mouse dams that were either obese (> 12 g fat mass) or lean (<5 g fat mass). This showed that the lipid metabolism in some tissues is affected more by obesity than others. Analysis of human serum (healthy nonpregnant women and pregnant women at 28 weeks' gestation) showed that the abundance of several phospholipids differed between groups. Human placenta from mothers with high and low BMI showed that lean placentae contain less polyunsaturated lipid. This platform offers a way to map lipid metabolism with immediate application in metabolic research and elsewhere.

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