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Activation of cumulus cell SMAD2/3 and epidermal growth factor receptor pathways are involved in porcine oocyte–cumulus cell expansion and steroidogenesis
Author(s) -
Nagyova Eva,
Camaioni Antonella,
Scsukova Sona,
Mlynarcikova Alzbeta,
Prochazka Radek,
Nemcova Lucie,
Salustri Antonietta
Publication year - 2011
Publication title -
molecular reproduction and development
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.745
H-Index - 105
eISSN - 1098-2795
pISSN - 1040-452X
DOI - 10.1002/mrd.21312
Subject(s) - autocrine signalling , paracrine signalling , biology , oocyte , cumulus oophorus , microbiology and biotechnology , signal transduction , epidermal growth factor , epidermal growth factor receptor , receptor , ovarian follicle , growth differentiation factor 9 , growth factor , medicine , endocrinology , folliculogenesis , hormone , embryogenesis , embryo , biochemistry
Several lines of evidence suggest that in mice the activation of SMAD2/3 signaling by oocyte secreted factors, together with epidermal growth factor receptor (EGFR) activation, is essential to induce cumulus expansion. Here we show that inhibition of EGFR kinase in follicle stimulating hormone (FSH)‐stimulated porcine oocyte–cumulus cell complex (OCCs) strongly decreases hyaluronan (HA) synthesis and its retention in the matrix, as well as progesterone synthesis. Although porcine cumulus cells undergo expansion independently of oocytes, we use biochemical and gene expression analyses to show that they do require activation of SMAD2/3 for optimal stimulation of HA synthesis and proteins involved in the organization of this polymer in the expanded matrix. Furthermore, FSH‐induced progesterone synthesis by porcine cumulus cells was increased by blocking SMAD2/3 activation. In conclusion, these results support the hypothesis that an FSH–EGF autocrine loop is active in porcine OCCs, and provide the first evidence that the SMAD2/3 signaling pathway is induced by paracrine/autocrine factors in porcine cumulus cells and is involved in the control of both cumulus expansion and steroidogenesis. Mol. Reprod. Dev. 78:391–402, 2011. © 2011 Wiley‐Liss, Inc.