Adiponectin Influences FGF2 in the Developing Porcine Corpus Luteum

Abstract

Luteal angiogenesis is regulated by pro-angiogenic hormones including fibroblast growth factor 2 (FGF2) and angiopoietin 1 (Ang1), which are regulated by the adipokine leptin during development. Another adipokine, adiponectin, exhibits an inverse relationship with leptin and has been identified in the CL. Therefore, it is hypothesized that adiponectin will influence pro-angiogenic hormones in the developing porcine CL. Crossbred sows were randomly allocated to one of two days of the estrous cycle, day 5 (D5; n = 4) or day 7 (D7; n = 5) for CL collection. Tissue was processed for immunohistochemical localization of adiponectin receptor 2 (AdipoR2), gene expression of FGF2, Ang1, leptin, AdipoR2, and cell culture for adiponectin treatment. The expression of AdipoR2 tended (p = 0.09) to be higher in D7 lutea and was more prevalently localized to the cell surface of large and small luteal cells than in D5 tissue. Adiponectin influenced (p ≤ 0.05) FGF2, leptin, and AdipoR2 gene expression relative to the dose and day (D5 or D7). Collectively, the evidence supports the supposition that adiponectin influences angiogenic factors in the developing CL.

Expression of Locally Produced Adipokines and Their Receptors during Different Physiological and Reproductive Stages in the Bovine Corpus Luteum

“…Research has shown that adiponectin plays a crucial role in oocyte maturation, granulosa cell proliferation, and steroid secretion in the ovaries [23]. Additionally, adiponectin has been suggested to influence angiogenic factors in the development of porcine CL [55]. Previous studies have reported higher adiponectin levels during the follicular stage, with particularly high levels in cumulus-oocyte complexes and theca cells of dominant follicles [56].…”

Local Expression Dynamics of Various Adipokines during Induced Luteal Regression (Luteolysis) in the Bovine Corpus Luteum

“…Adiponectin's mRNA levels remained consistently expressed across all time points, with a downregulation at 48 h (Figure 2A). Additionally, adiponectin has been suggested to influence angiogenic factors in developing porcine CL [59]. The expression of adiponectin receptor 1 remained at low levels without significant changes.…”