Proteomics of the Human Endometrial Glandular Epithelium and Stroma from the Proliferative and Secretory Phases of the Menstrual Cycle1

Abstract

Despite its importance in reproductive biology and women's health, a detailed molecular-level understanding of the human endometrium is lacking. Indeed, no comprehensive studies have been undertaken to elucidate the important protein expression differences between the endometrial glandular epithelium and surrounding stroma during the proliferative and midsecretory phases of the menstrual cycle. We utilized laser microdissection to harvest epithelial cells and stromal compartments from proliferative and secretory premenopausal endometrial tissue and performed a global, quantitative mass spectrometry-based proteomics analysis. This analysis identified 1224 total proteins from epithelial cells, among which 318 were differentially abundant between the proliferative and secretory phases (q < 0.05), and 1005 proteins from the stromal compartments, 19 of which were differentially abundant between the phases (q < 0.05). Several proteins were chosen for validation by immunohistochemistry in an independent set of uterine tissues, including carboxypeptidase M, tenascin C, neprilysin, and ectonucleotide pyrophosphatase/phosphodiesterase family member 3 (ENPP3). ENPP3, which was elevated in epithelial glandular cells in the secretory phase, was confirmed to be elevated in midsecretory-phase baboon uterine lavage samples and also observed to have an N-linked glycosylated form that was not observed in the proliferative phase. This study provides a detailed view into the global proteomic alterations of the epithelial cells and stromal compartments of the cycling premenopausal endometrium. These proteomic alterations during endometrial remodeling provide a basis for numerous follow-up investigations on the function of these differentially regulated proteins and their role in reproductive biology and endometrial pathologies.

Race‐specific molecular alterations correlate with differential outcomes for black and white endometrioid endometrial cancer patients

“…15 Proteomic discovery data were filtered so that abundance levels of candidates satisfied a peptide spectral match 2 in at least two-thirds of the patients analyzed for a given comparator cohort. 15 Proteomic discovery data were filtered so that abundance levels of candidates satisfied a peptide spectral match 2 in at least two-thirds of the patients analyzed for a given comparator cohort.…”

“…Tissue samples were processed and subjected to LC-MS/ MS-based proteomic analyses as previously described. 15 Proteomic discovery data were filtered so that abundance levels of candidates satisfied a peptide spectral match 2 in at least two-thirds of the patients analyzed for a given comparator cohort. Significantly altered proteins between black and white patients in discovery LC-MS/MS analyses were identified with a Wilcoxon rank-sum test on the basis of peptide spectral matches normalized to the patient sample exhibiting the lowest total peptide spectral match counts.…”

Hematological and Neurological Expressed 1 (HN1): a predictive and pharmacodynamic biomarker of metformin response in endometrial cancers

“…samples were processed and analyzed by high resolution LC-MS/MS on an Orbitrap Velos MS (Thermo Fisher, San Jose, CA) and HN1 IP samples (preparation described below) were similarly analyzed on a Fusion Lumos MS (Thermo Fisher) as previously described (16,17).…”

The Use of Proteomics in Assisted Reproduction

“…Hood et al performed a global quantitative MS proteomic analysis in both epithelial and stromal cells during the proliferative and secretory phase and managed to identify 318 and 19 differentially overexpressed proteins between phases in the uterine epithelium and stroma, respectively. Further immunohistochemical techniques were applied to a subset of these proteins in order to elucidate eventual modifications during the menstrual cycle (112). MALDI/MS profiling in endometrial biopsies from the 16th to the 21st day of the menstrual cycle (implantation window) in eight fertile women identified annexin A2 and stathmin as possible markers of the receptive capacity of the endometrium (113).…”