Reproduction Abstracts

Introduction: Human germ cells develop in synchronised nests in the fetal ovary, interspersed with somatic cells prior to reorganisation to form primordial follicles. We have isolated several somatic cell lines from disaggregated human fetal ovaries as a model for understanding their contribution to the germ cell niche. Fetal dysregulation of TGFβ signalling has been linked with fibrosis in polycystic ovary syndrome (PCOS): effects of TGFβ on extracellular matrix (ECM) components in these somatic cells have therefore been investigated.

Materials and methods: Expression of key somatic cell markers was assessed by qRT-PCR across a number of passages. Changes in the expression of ECM and epithelial to mesenchymal transition (EMT) associated genes in response to 5 ng/ml TGFβ1 or its inhibitor SB431542 (10 μM) for 24 h were also determined.

Results and discussion: Expression of markers associated with pre-granulosa cells (e.g. FOXL2, ID2, and AR) was retained for at least eight passages. TGFβ-signalling pathway associated genes showed up-regulated expression in these cells and many were reciprocally sensitive to exogenous TGFβ1 (TGFB1, LTBP1, LTBP2, TGFBI, INHBA up-regulated) and SB431542 (aforementioned plus LTBP4, FBN1 down-regulated). Several other ECM and EMT-associated genes (CTGF, THBS1, FN1, ITGA5, ITGB1, SNAI1, CDH2, and ACTA2) were also down-regulated by SB431542 while SNAI2 was up-regulated. CTGF, THBS1, and SNAI1 were up-regulated by TGFβ1. CDH2, ITGA5, and ITGB1 are associated with cell adhesion while increased CTGF, and TGFB1 can lead to tissue fibrosis. This suggests a key role for the TGFβ pathway in normal ovary development.