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

Abstract

This study aimed to determine the gene expression of different local novel adipokines, such as vaspin, adiponectin, visfatin, and resistin, and their known receptors, namely, heat shock 70 protein 5, adiponectin receptor 1, and adiponectin receptor 2, in the bovine corpus luteum (CL) during different phases of the estrous cycle (on days 1–2, 3–4, 5–7, 8–12, 13–18, >18) and pregnancy (at months 1–2, 3–4, 5–7, >7). The mRNA expression was measured by reverse transcription polymerase chain reaction (RT-qPCR). The mRNA expression levels were normalized to the geometric mean of all three constantly expressed reference genes (cyclophilin A, ubiquitin, ubiquitin C). Our findings suggest that adipokines are expressed and present in all investigated groups, and are specifically up- or downregulated during the estrus cycle and during pregnancy. Vaspin and adiponectin levels were upregulated in the middle and late cycle stages. Resistin was abundant during the CL regression stage and in the first months of pregnancy. The specific expression of adipokine receptors indicates their involvement in the local mechanisms that regulate CL function. Further investigations are required to elucidate the regulative mechanisms underlying the different local effects of adipokines on the ovarian physiology of cows.

Expression dynamics of adipokines during induced ovulation in the bovine follicles and early corpus luteum

“…Moreover, adiponectin and leptin can set MAPKs in motion, which are pivotal for cell proliferation, differentiation and apoptosis (Booth et al., 2015; Clemente‐Suárez et al., 2023; Kim et al., 2022; Kim & Bajaj, 2014). Our previous studies demonstrate that numerous adipokines are present in the CL during all cyclic and pregnancy stages, suggesting their important role in regulating CL function and induced luteolysis in the cow (Thaqi et al., 2023a, 2023b). Our study builds on this foundation by demonstrating elevated vaspin levels 4 h post‐GnRH application, hinting at a regulatory or triggering role in follicle growth, maturation and ovulation.…”

“…The Luna® Universal Probe One‐PCR system (New England BioLabs Inc., Ipswich, MA, USA) facilitated one‐step real‐time quantification in a 10 μL reaction volume. The thermal cycler (Rotor‐Gene Q, model 5‐Plex HRM, Qiagen) followed this cycling protocol: a reverse transcription (RT) step at 55°C for 10 min, initial denaturation at 95°C before qPCR, followed by 45 cycles of denaturation at 95°C for 10 s and extension at 60°C for 30 s. The entire RT‐qPCR workflow adhered to the MIQE (Minimum Information for Publication of Quantitative Real‐Time PCR Experiments) guidelines (Thaqi et al., 2023a).…”

“…In the context of data normalization, the mRNA expression levels underwent alignment through normalization against the geometric mean derived from two reference genes: cyclophilin A (PPIA) and ubiquitin (UBAA52). Following normalization, the ∆∆ Cq method compared normalized expression differences between the ‘treatment group’ and the non‐treated ‘control group’ (Livak & Schmittgen, 2001; Thaqi et al., 2023a). The initial set of follicle samples before treatment (0 h) served as the control group with an assigned value of 1.0.…”

“…Disruptions in folliculogenesis can contribute to fertility issues (Esencan et al., 2022; Gershon & Dekel, 2020). Notably, a category of cytokines known as adipokines, originating primarily from adipose tissue, exerts influence on various tissues through autocrine and paracrine mechanisms (Kim et al., 2022; Mitchell et al., 2005; Reverchon et al., 2014; Thaqi et al., 2023a, 2023b). This group encompasses adiponectin, vaspin, visfatin, resistin, chemerin, leptin and apelin, forming a distinctive set of biochemical messengers.…”

Adipokines and Reproduction in Ruminant Livestock

“…The ovary has also been shown to serve as a target organ for adipokines. The presence of leptin, chemerin, vaspin, adiponectin, visfatin, and resistin has been confirmed in various ovarian and testicular structures, including the granulosa, theca, luteal cells, seminal plasma, and Leydig cells [14,15]. According to the studies mentioned above, adipokines link metabolic status with reproduction in most domestic animals.…”