Progress of Adipokines in the Female Reproductive System: A Focus on Polycystic Ovary Syndrome

Usefulness of the Sympto-Thermal Method with Standardized Cervical Mucus Assessment (InVivo Method) for Evaluating the Monthly Cycle in Women with Polycystic Ovary Syndrome (PCOS)

(1) Background: FABMs (fertility awareness-based methods) are methods that rely on the observation of clinical signs related to fertility found in women, the so-called fertility bioindicators. They can be a valuable tool for diagnosing monthly cycle disorders and infertility, for example, among patients with PCOS (polycystic ovary syndrome). Until now, it has been difficult for women with PCOS to use FABM, due to the difficulty of describing fertility bioindicators and their disorders due to the biology of the syndrome. The new InVivo sympto-thermal method with standardized cervical mucus assessment may provide a valuable diagnostic and therapeutic tool for observing the monthly cycle in this group of women. (2) Methods: The monthly cycle was evaluated in a group of 32 women of reproductive age. A total of 108 monthly cycle observation cards were analyzed: 35 monthly cycle cards were collected from 18 women with PCOS, and 73 monthly cycle cards collected from 14 healthy women. In addition, 32 pairs of macroscopic and microscopic images were evaluated: 17 pairs from the study group (four subjects) and 15 pairs from women in the control group (six subjects). (3) Results: We showed that in the group of patients with PCOS, menstruation was longer (p = 0.000814), the number of mucus peaks was statistically higher (p = 0.040747), and the interquartile range (IQR) of the duration of the follicular phase (calculated according to the BBT) was significantly higher (8 days) compared to women in the control group. We also observed that among all the women studied, the microscopic image of cervical mucus correlated with the cycle phase described in the observation card, as determined by reference to the BBT chart, provided that it showed the correct features. (4) Conclusions: Systematic maintenance of monthly cycle observation charts using the InVivo method can be an important supplement to the medical history, as it allows for a thorough assessment of, among others, the timing of monthly bleeding, cervical mucus symptoms, BBT changes, and the duration of the follicular and luteal phases among both healthy and PCOS women.

Regulation and Role of Adiponectin Secretion in Rat Ovarian Granulosa Cells

Adiponectin is an important adipokine involved in glucose and lipid metabolism, but its secretion and potential role in regulating glucose utilization during ovarian development remains unclear. This study aims to investigate the mechanism and effects of follicle-stimulating hormones (FSHs) on adiponectin secretion and its following impact on glucose transport in the granulosa cells of rat ovaries. A range of experimental techniques were utilized to test our research, including immunoblotting, immunohistochemistry, immunofluorescence, ELISA, histological staining, real-time quantitative PCR, and transcriptome analysis. The immunohistochemistry results indicated that adiponectin was primarily located in the granulosa cells of rat ovaries. In primary granulosa cells cultured in vitro, both Western blot and immunofluorescence assays demonstrated that FSH significantly induced adiponectin secretion within 2 h of incubation, primarily via the PKA signaling pathway rather than the PI3K/AKT pathway. Concurrently, the addition of the AdipoR1/AdipoR2 dual agonist AdipoRon to the culture medium significantly stimulated the protein expression of GLUT1 in rat granulosa cells, resulting in enhanced glucose absorption. Consistent with these in vitro findings, rats injected with eCG (which shares structural and functional similarities with FSH) exhibited significantly increased adiponectin levels in both the ovaries and blood. Moreover, there was a notable elevation in mRNA and protein levels of AdipoRs and GLUTs following eCG administration. Transcriptomic analysis further revealed a positive correlation between the expression of the intraovarian adiponectin system and glucose transporter. The present study represents a novel investigation, demonstrating that FSH stimulates adiponectin secretion in ovarian granulosa cells through the PKA signaling pathway. This mechanism potentially influences glucose transport (GLUT1) and utilization within the ovaries.

Relation of resistin gene variants to resistin plasma levels and altered susceptibility to polycystic ovary syndrome: A case control study

BACKGROUND

A role for resistin in the pathogenesis of polycystic ovarian syndrome (PCOS) and related features were described for various ethnicities. As its expression is partly inherited, a role for RETN polymorphisms in regulating resistin levels and PCOS risk was shown, but with varied results.

AIM

To investigate the association of rs34124816 (-537A>C), rs1862513 (-420C>G), rs3219175 (-358G>A), rs3745367 (+299G>A), rs3745369 (+1263G>C), and rs1423096 (+4965C>T) RETN SNPs with PCOS.

METHODS

Study subjects included 583 women with PCOS, and 713 eumenorrheic women serving as controls. Genotyping was done by real-time PCR.

RESULTS

Higher minor allele frequency (MAF) of rs34124816, rs3219175, and rs3745369, and lower MAF of rs1862513 and rs1423096 were seen in PCOS cases. Reduced PCOS risk was found with rs3745367 minor-allele homozygotes and rs1423096 minor-allele homozygotes, while increased risk was linked with rs3745367 heterozygotes, and with rs3745369 heterozygotes and minor-allele homozygotes. While it did not reach statistical significance, serum resistin levels were elevated in PCOS cases than in control women and major-allele homozygotes of rs34124816 and rs1862513, and in rs1423096 minor-allele-containing carriers. Carriage of rs34124816 correlated positively with age and LH, whereas rs1862513 positively and rs3745367 negatively correlated with fasting glucose. Six-locus (rs34124816-rs1862513-rs3219175-rs3745367-rs3745369-rs1423096) haplotype analysis demonstrated a significant reduction in AGGGGG and a marked increase in AGGGCG haplotypes between cases and controls, thus assigning PCOS protective and susceptible nature to these haplotypes, respectively.

CONCLUSIONS

This study is the first to document the contribution of rs34124816 and rs1423096 RETN variants to the risk of PCOS. The varied association of RETN gene variants with PCOS suggests an ethnic contribution of RETN association with PCOS.

The Role of Selected Adipocytokines in Ovarian Cancer and Endometrial Cancer

Due to their multidirectional influence, adipocytokines are currently the subject of numerous intensive studies. Significant impact applies to many processes, both physiological and pathological. Moreover, the role of adipocytokines in carcinogenesis seems particularly interesting and not fully understood. For this reason, ongoing research focuses on the role of these compounds in the network of interactions in the tumor microenvironment. Particular attention should be drawn to cancers that remain challenging for modern gynecological oncology-ovarian and endometrial cancer. This paper presents the role of selected adipocytokines, including leptin, adiponectin, visfatin, resistin, apelin, chemerin, omentin and vaspin in cancer, with a particular focus on ovarian and endometrial cancer, and their potential clinical relevance.

Meteorin-like/Metrnl, a novel secreted protein implicated in inflammation, immunology, and metabolism: A comprehensive review of preclinical and clinical studies

Meteorin-like, also known as Metrnl, Meteorin-β, Subfatin, and Cometin, is a novel secreted protein exerting pleiotropic effects on inflammation, immunology, and metabolism. Earlier research on this hormone focused on regulating energy expenditure and glucose homeostasis. Consequently, several studies attempted to characterize the molecule mechanism of Metrnl in glucose metabolism and obesity-related disorders but reported contradictory clinical results. Recent studies gradually noticed its multiple protective functions in inflammatory immune regulations and cardiometabolic diseases, such as inducing macrophage activation, angiogenesis, tissue remodeling, bone formation, and preventing dyslipidemias. A comprehensive understanding of this novel protein is essential to identify its significance as a potential therapeutic drug or a biomarker of certain diseases. In this review, we present the current knowledge on the physiology of Metrnl and its roles in inflammation, immunology, and metabolism, including animal/cell interventional preclinical studies and human clinical studies. We also describe controversies regarding the data of circulation Metrnl in different disease states to determine its clinical application better.

The Complex Roles of Adipokines in Polycystic Ovary Syndrome and Endometriosis

Polycystic ovary syndrome (PCOS) and endometriosis are frequent diseases of the female reproductive tract causing high morbidity as they can significantly affect fertility and quality of life. Adipokines are pleiotropic signaling molecules secreted by white or brown adipose tissues with a central role in energy metabolism. More recently, their involvement in PCOS and endometriosis has been demonstrated. In this review article, we provide an update on the role of adipokines in both diseases and summarize previous findings. We also address the results of multi-omics approaches in adipokine research to examine the role of single nucleotide polymorphisms (SNPs) in genes coding for adipokines and their receptors, the secretome of adipocytes and to identify epigenetic alterations of adipokine genes that might be conferred from mother to child. Finally, we address novel data on the role of brown adipose tissue (BAT), which seems to have notable effects on PCOS. For this review, original research articles on adipokine actions in PCOS and endometriosis are considered, which are listed in the PubMed database.

Anti-Tumoral Effect of Chemerin on Ovarian Cancer Cell Lines Mediated by Activation of Interferon Alpha Response

Simple Summary

Chemerin is a multifunctional protein with an important role in the immune system. Recent evidence showed that chemerin also regulates the development of cancer. Ovarian cancer is a common type of tumor in women. In this study, we observed that chemerin decreases the growth of ovarian cancer cell lines in vitro when cultivated in standard cell culture or in globular multicellular aggregates. When we examined the mechanisms involved in this process, we found that treatment of ovarian cancer cells with chemerin led to the activation of genes that are known to mediate the effects of interferon alpha (IFNα). The main effect of IFNα is to defend body cells against viral infections, but it is also able to defeat cancer cells. We observed that this activation of IFNα response by chemerin resulted from the increased production of IFNα protein in ovarian cancer cells, which then reduced cancer cells numbers. However, it remains to be investigated how exactly chemerin might be able to activate interferon alpha and its anti-tumoral actions.

Abstract

The pleiotropic adipokine chemerin affects tumor growth primarily as anti-tumoral chemoattractant inducing immunocyte recruitment. However, little is known about its effect on ovarian adenocarcinoma. In this study, we examined chemerin actions on ovarian cancer cell lines in vitro and intended to elucidate involved cell signaling mechanisms. Employing three ovarian cancer cell lines, we observed differentially pronounced effects of this adipokine. Treatment with chemerin (huChem-157) significantly reduced OVCAR-3 cell numbers (by 40.8% on day 6) and decreased the colony and spheroid growth of these cells by half. The spheroid size of SK-OV-3 ovarian cancer cells was also significantly reduced upon treatment. Transcriptome analyses of chemerin-treated cells revealed the most notably induced genes to be interferon alpha (IFNα)-response genes like IFI27, OAS1 and IFIT1 and their upstream regulator IRF9 in all cell lines tested. Finally, we found this adipokine to elevate IFNα levels about fourfold in culture medium of the employed cell lines. In conclusion, our data for the first time demonstrate IFNα as a mediator of chemerin action in vitro. The observed anti-tumoral effect of chemerin on ovarian cancer cells in vitro was mediated by the notable activation of IFNα response genes, resulting from the chemerin-triggered increase of secreted levels of this cytokine.