Reproduction Abstracts

It has been previously shown that multimeric pentraxin 3 (PTX3) is a key component of the cumulus oophorus extracellular matrix. Noteworthy, cumuli from PTX3^−/− mice were defective in matrix organization and fertility was impaired. PTX3 binds to both tumor necrosis factor alpha-induced protein 6 (TNFAIP6) and inter-alpha-trypsin inhibitor thereby likely serving as a cross linker for multiple hyaluronan molecules, stabilizing in this way the cumulus oophorus extracellular matrix. We investigated whether PTX3 is also expressed in porcine preovulatory follicle. Oocyte-cumulus complexes (OCC) and granulosa cells (GC) from gilts were either stimulated in vivo with PMSG and hCG (4, 8, 16, 24, and 32 h) or cultured in vitro (4, 24, and 44 h) with FSH/LH. Methods performed were real-time RT-PCR, western blot analysis and immunostaining. Expression of PTX3 transcripts was significantly increased 24 h after either in vivo hCG stimulation or in vitro FSH/LH treatment in both OCC and GC. Western blot analysis with PTX3 antibody revealed that not only matrix extracts from naturally cycling gilts contain high levels of PTX3 protein (~49 kDa) but also matrix extracts of FSH/LH-stimulated OCC cultured in medium supplemented with follicular fluid or porcine serum. Localization of PTX3 in the extracellular matrix was confirmed by immunohistochemistry. This research was supported as follows: ‘collaboration via a fellowship (EN) under the OECD Co-Operative Research Programme: Biological Resource Management for Sustainable Agricultural Systems’ and by Grant P502/11/0593 from GA of the Czech Republic.