Pre-ovulatory follicle size modulates the periovulatory endocrine environment and endometrial tissue phenotype in cattle

ABSTRACT: Purpouse: Aims of this study were (1) to characterize the endometrial transcriptome, (2) to identify functional pathways, and (3) to molecularly characterize selected pathways overrepresented in the endometrium of day 7 post-ovulation induction of cows treated to ovulate larger versus smaller follicles Methods: Seventy-four multiparous, nonlactating, presynchronized Nelore cows received a progesterone-releasing device and estradiol benzoate on Day–10 (D−10). Animals received cloprostenol (large follicle-large CL group; LF-LCL; N = 35) or not (small follicle-small CL group; SF-SCL; N = 39) on D−10. Progesterone devices were withdrawn and cloprostenol administered 42 to 54 hours (LF-LCL) or 30 to 36 hours (SF-SCL) before GnRH treatment (D0). Tissues were collected at slaughter on D7. Transcriptional profiling of the endometrial tissue was performed by RNA-seq and protein markers for proliferation and apoptosis were identified by immunohistochemistry. Results: Functional enrichment data indicated that LF-LCL endometrium expressed greater abundance of genes associated with biosynthetic and metabolic processes, whereas SF-SCL endometrium .gene expression profile was biased towards cell proliferation. Extracellular matrix-related genes were also upregulated in the SF-SCL endometrium suggesting reorganization of the ECM towards a proliferation permissive phenotype. Immunohistochemistry data confirmed the greater proliferative activity observed in SF-SCL endometrium I comparison to LF-LCL counterparts, and indicated a time-related transition within experimental group. In conclusion, the periovulatory endocrine milieu regulates bovine endometrial gene expression. Furthermore, timing and amplitude of ovarian steroid secretion pattern seem to determine the transition from a proliferation permissive to a biosynthetic and metabolically active endometrial phenotype, which may be associated with the preparation of an optimally receptive uterine environment. Conclusion: the periovulatory endocrine milieu affected D7 endometrial molecular signature. Main pathways affected were related to cell proliferation, ECM composition and remodeling, biosynthetic and metabolic processes. Reported data further suggest that the endometrial tissue from LF-LCL cows experienced an early proliferative phase (D4), whereas the SF-SCL endometrium, exposed to a distinct periovulatory endocrine environment, expressed a delayed onset of the proliferative activity (D7).

ORGANISM(S): Bos indicus

PROVIDER: GSE65450 | GEO | 2015/07/01

REPOSITORIES: GEO