C-X-C motif chemokine receptor 4 (CXCR4) and its ligand stromal cell-derived factor 1 (SDF1) protein expression in the ovary during the natural estrous cycle of the domestic cat (Felis catus)

PELUFFO, MC; EDELSZTEIN, NADIA Y.

Mar del Plata

Congreso; Reunión anual de Sociedades Biocientíficas; 2019

SAIC junto a otras sociedades

Expression of immune function genes (e.g. chemokine receptors) within follicle cells has been reported in ovaries from different species, suggesting that chemokine action in the ovary may extend beyond its role as a chemoattractant. In neonatal mouse ovaries, interaction between the chemokine receptor CXCR4 and its ligand SDF1 has been shown to prevent primordial-to-primary follicle transition. Our laboratory has previously shown that CXCR4 and SDF1 are expressed in the cumulus cells and oocyte of cumulus-oocyte complexes (COCs) retrieved from feline antral follicles, and that SDF1 significantly increases the expression of key ovulatory genes HAS2 and TNFAIP6 within the feline COC in vitro, through its main receptor CXCR4. Thus, the aim of this study was to analyze the protein expression and localization of the chemokine receptor CXCR4 and its ligand SDF1 in the ovary during the natural estrous cycle of the domestic cat (Felis catus). Ovaries from adult cats (n=12) in different stages of the estrous cycle -estrus, diestrus and anestrus- were collected, fixed and processed for immunohistochemistry. Immunolocalization of CXCR4 was distinguished in the nucleus and/or cytoplasm of various cell types (oocyte, cumulus, granulosa, theca and luteal cells) within follicles -ranging from primordial to pre-ovalutory-and the corpora lutea. CXCR4 positive staining was non-homogenous and varied depending on the developmental stage of the follicles and the phase of the estrous cycle. We observed that CXCR4 was strongly noticeable in the interstitial cells from the stroma in all stages of the cycle. SDF1 showed a similar expression pattern to that of its receptor. In summary, the receptor CXCR4 and its ligand SDF1 are differentially expressed in various cell types within the feline ovary during the natural estrous cycle, supporting possible roles for them in the ovary that surpass their chemoattractant function. Further analysis is needed to elucidate these potential novel roles.