Differential expression of inflammation-related genes in the ovarian stroma and granulosa cells of PCOS women

Polycystic ovary syndrome (PCOS) is the most common female endocrine disorder. Ovarian changes in PCOS women are well characterized by ultrasound. However, the ovarian pathophysiology is not fully understood. The aim of this study was to characterize the expression, in both the central ovarian stroma and in granulosa cells (GCs), of a number of genes, including several inflammation-related genes, which have been hypothesized to be involved in the pathophysiology of PCOS. Biopsies of the central ovarian stroma were obtained from PCOS women (Rotterdam criteria) and from normally ovulating women in follicular phase. GCs were retrieved from PCOS-women and non-PCOS women, undergoing in vitro maturation. The expressions of 57 genes were analyzed by quantitative-PCR using a low-density-gene array. The main outcome measures were over-expression or under-expression of the specific genes. The results showed that in the central stroma of PCOS ovaries, five inflammation-related genes (CCL2, IL1R1, IL8, NOS2, TIMP1), the leukocyte marker CD45, the inflammation-related transcription factor RUNX2 and the growth factor AREG were under-expressed. The growth factor DUSP12 and the coagulation factor TFPI2 were over-expressed. In the GC of PCOS, all of the differentially expressed genes were over-expressed; the inflammation-related IL1B, IL8, LIF, NOS2 and PTGS2, the coagulation-related F3 and THBS1, the growth factors BMP6 and DUSP12, the permeability-related AQ3 and the growth-arrest-related GADD45A. In conclusion, the results indicate major alterations in the local ovarian immune system of PCOS ovaries. This may have implications for the PCOS-related defects in the inflammation-like ovulatory process and for the susceptibility to acquire the inflammatory state of ovarian hyperstimulation syndrome.