Parallel variations of insulin-like peptide 3 (INSL3) and antimüllerian hormone (AMH) in women with the polycystic ovary syndrome according to menstrual cycle pattern

Insulin-like peptide 5 (INSL5) positively correlates with anti-Müllerian hormone (AMH) in women with the polycystic ovary syndrome: a case-control study

BACKGROUND

Insulin-like peptide 5 (INSL5) is involved in both reproductive and metabolic processes in polycystic ovary syndrome (PCOS). This study aimed to evaluate the relationship between INSL5 and anti-Müllerian hormone (AMH).

METHODS

A retrospective case-control study was conducted in a university-based reproductive centre between December 2019 and January 2021. We included 117 women with PCOS and 100 healthy subjects from Zhejiang Province. All subjects were divided into four groups (1st-4th) based on quartiles of serum INSL5 levels. Serum INSL5 concentration was assayed using an enzyme-linked immunosorbent assay.

RESULTS

A significant direct association was observed between serum INSL5 and AMH levels in women with PCOS. The mean AMH level in the 1st-4th INSL5 level quartiles were 4.64, 5.20, 6.46, and 9.48 ng/ml, respectively (P < 0.001). After adjusting for age, body mass index, metabolic indices, and serum levels of oestradiol and total testosterone, AMH levels remained positively and significantly associated with INSL5 levels (P for trend < 0.001). The diagnostic value of AMH was better than that of INSL5.

CONCLUSIONS

INSL5 and AMH levels were significantly correlated and elevated in women with PCOS. INSL5 and AMH might be associated with increased androgen secretion and chronic anovulation in PCOS.

Relaxin ligand/receptor systems in the developing teleost fish brain: Conserved features with mammals and a platform to address neuropeptide system functions

The relaxins (RLNs) are a group of peptide hormone/neuromodulators that can regulate a wide range of physiological processes ranging from reproduction to brain function. All the family members have originated from a RLN3-like ancestor via different rounds of whole genome and gene specific duplications during vertebrate evolution. In mammals, including human, the divergence of the different family members and the emergence of new members led to the acquisition of specific functions for the various relaxin family peptide and associated receptor genes. In particular, in mammals, it was shown, that the role of RLN3 is correlated to the modulation of arousal, stress responses, emotion, social recognition, and other brain functions, positioning this gene/peptide as a potential therapeutic target for neuropsychiatric disorders. This review highlights the evolutionary conservation of relaxin family peptide and receptor gene expression and their associated brain neural circuits. In the zebrafish, the expression pattern of the different relaxin family members has specific features that are conserved in higher species, including a likely similar functional role for the ancestral RLN3-like gene. The use of different model organisms, particularly the zebrafish, to explore the diversification and conservation of relaxin family ligands and receptor systems, provides a relatively high-throughput platform to identify their specific conserved or differential neuromodulatory roles in higher species including human.

Insulin‐like peptide 3 in domestic animals with normal and abnormal reproductive functions, in comparison to rodents and humans

Background

Methods

Main findings

Conclusion

Diverse functions of insulin-like 3 peptide

Insulin-like 3 peptide (INSL3) is a member of the insulin-like peptide superfamily and is the only known physiological ligand of relaxin family peptide receptor 2 (RXFP2), a G protein-coupled receptor (GPCR). In mammals, INSL3 is primarily produced both in testicular Leydig cells and in ovarian theca cells, but circulating levels of the hormone are much higher in males than in females. The INSL3/RXFP2 system has an essential role in the development of the gubernaculum for the initial transabdominal descent of the testis and in maintaining proper reproductive health in men. Although its function in female physiology has been less well-characterized, it was reported that INSL3 deletion affects antral follicle development during the follicular phase of the menstrual cycle and uterus function. Since the discovery of its role in the reproductive system, the study of INSL3/RXFP2 has expanded to others organs, such as skeletal muscle, bone, kidney, thyroid, brain, and eye. This review aims to summarize the various advances in understanding the physiological function of this ligand-receptor pair since its first discovery and elucidate its future therapeutic potential in the management of various diseases.

Comprehensive analysis of mRNAs and miRNAs in the ovarian follicles of uniparous and multiple goats at estrus phase

Background

Fertility is an important economic trait in the production of meat goat, and follicular development plays an important role in fertility. Although many mRNAs and microRNAs (miRNAs) have been found to play critical roles in ovarian biological processes, the interaction between mRNAs and miRNAs in follicular development is not yet completely understood. In addition, less attention has been given to the study of single follicle (dominant or atretic follicle) in goats. This study aimed to identify mRNAs, miRNAs, and signaling pathways as well as their interaction networks in the ovarian follicles (large follicles and small follicles) of uniparous and multiple Chuanzhong black goats at estrus phase using RNA-sequencing (RNA-seq) technique.

Results

The results showed that there was a significant difference in the number of large follicles between uniparous and multiple goats (P < 0.05), but no difference in the number of small follicles was observed (P > 0.05). For the small follicles of uniparous and multiple goats at estrus phase, 289 differentially expressed mRNAs (DEmRNAs) and 16 DEmiRNAs were identified; and for the large follicles, 195 DEmRNAs and 7 DEmiRNAs were identified. The functional enrichment analysis showed that DE genes in small follicles were significantly enriched in ovarian steroidogenesis and steroid hormone biosynthesis, while in large follicles were significantly enriched in ABC transporters and steroid hormone biosynthesis. The results of quantitative real-time polymerase chain reaction were consistent with those of RNA-seq. Analysis of the mRNA-miRNA interaction network suggested that CD36 (miR-122, miR-200a, miR-141), TNFAIP6 (miR-141, miR-200a, miR-182), CYP11A1 (miR-122), SERPINA5 (miR-1, miR-206, miR-133a-3p, miR-133b), and PTGFR (miR-182, miR-122) might be related to fertility, but requires further research on follicular somatic cells.

Conclusions

This study was used for the first time to reveal the DEmRNAs and DEmiRNAs as well as their interaction in the follicles of uniparous and multiple goats at estrus phase using RNA-seq technology. Our findings provide new clues to uncover the molecular mechanisms and signaling networks of goat reproduction that could be potentially used to increase ovulation rate and kidding rate in goat.

Circulating insulin-like peptide 5 levels and its association with metabolic and hormonal parameters in women with polycystic ovary syndrome

PURPOSE

Insulin-like peptide 5 (INSL5) is a gut peptide hormone that is a member of relaxin/insulin superfamily. Growing evidence implicates the crucial role of the peptide in some metabolisms including food intake, glucose homeostasis and reproductive system. Polycystic ovary syndrome (PCOS) is involved in both reproductive and metabolic issues. The aim of the study was determination of circulating levels of INSL5 alteration in women with PCOS and evaluation of the relationship between INSL5 and hormonal-metabolic parameters as well as carotid intima media thickness (cIMT).

METHODS

A total of 164 subjects were recruited in this cross-sectional study (82 women with PCOS and 82 age- and BMI-matched controls). Circulating INSL5 levels were assessed via ELISA method. High-resolution B-mode ultrasound was used to measure cIMT. The hormonal and metabolic parameters of the recruited subjects were determined.

RESULTS

Circulating INSL5 levels were significantly elevated in women with PCOS compared to controls (27.63 ± 7.74 vs. 19.90 ± 5.85 ng/ml, P < 0.001). The mean values of INSL5 were significantly higher in overweight subjects compared to lean weight subjects in both groups. The women with PCOS having insulin resistance have increased INSL5 compared to those of PCOS subjects without insulin resistance. INSL5 is associated with insulin resistance, BMI, luteinizing hormone and free androgen index. Multivariate logistic regression analyses revealed that the odds ratio for having PCOS in the highest tertile of INSL5 was higher than in the lowest tertile.

CONCLUSIONS

PCOS subjects exhibited an elevation in circulating INSL5 levels along with a link between INSL5 level induction and metabolic-hormonal parameters.

TMT Based Proteomic Analysis of Human Follicular Fluid From Overweight/Obese and Normal-Weight Patients With Polycystic Ovary Syndrome

Background: Polycystic ovary syndrome (PCOS) is a major endocrine and metabolic disorder with heterogeneous manifestations and complex etiology. As a leading cause of anovulatory infertility, the molecular diversity of the follicular microenvironment has not been fully elucidated. The aim of the present study was to investigate the follicular fluid proteomic profiles of overweight/obese and normal-weight women with PCOS, to identify novel molecular mechanisms underlying PCOS and to determine the effect of obesity on the follicular fluid protein profiles. Methods: Follicular fluid samples were collected from 3 different groups: overweight/obese PCOS patients (n = 29), normal-weight PCOS patients (n = 29), and normo-ovulatory controls (n = 29). We used a quantitative approach with tandem mass tag labeling and liquid chromatography tandem mass spectrometry to identify the differentially expressed proteins. Differential abundance of four selected proteins was confirmed by ELISA. Gene Set Enrichment Analysis was also conducted to further explore our findings. Furthermore, we compared the clinical, hormonal, and biochemical characteristics of overweight/obese and normal-weight patients with PCOS to determine the effects of obesity. Results: A total of 1,153 proteins were identified, of which 41 and 19 proteins were differentially expressed in the overweight/obese PCOS group vs. the control group, and in the normal-weight PCOS group vs. the control group, respectively. Bioinformatics analyses showed that the inflammatory, immunological, and metabolic-related biological processes were co-enriched in both subgroups of PCOS. Apolipoprotein A-II, complement C5, fetuin-B, and stromal cell-derived factor 1 were found to be involved in various processes and were validated using the ELISA analysis. From clinical features and proteomic data, obesity was found to worsen follicular development disturbances in PCOS. Conclusion: In this proteomic study, a panel of proteins were found differentially expressed in the follicular fluid of PCOS. Inflammatory, immunological, and metabolic abnormalities were identified inside the intra-follicular environment, which could be aggravated by obesity. The identified proteins were correlated with follicular growth and may be considered as candidate biomarkers as well as therapeutic targets of PCOS.

Evaluation of the correlation between insulin like factor 3, polycystic ovary syndrome, and ovarian maldescent

The aim of this study was to investigate a proposed correlation between the incidentally discovered undescended ovaries and their confirmed diagnosis as a polycystic ovary disease (PCOD) for all cases included, and to evaluate the role of estimated insulin like factor 3 (INSL3) circulating level in the pathogenesis of both abnormal findings. The study group (A) comprised 35 women whose ovaries had been incidentally found to be undescended during the routine laparoscopy for infertility causes, and all had been diagnosed as PCOD. The control category included two subgroups; subgroup (B) included 35 women group, diagnosed as PCOD but with normally allocated ovaries in the true pelvis, and subgroup (C) included 35 healthy women with regular menses and no signs of hyperandrogenism. Correlations between the level of INSL3 and other PCOD relevant biochemical tests: [e.g. BMI, waist-to-hip ratio (WHR), LH, FSH, androstendione (A), total and free testosterone (T & Ft), DHEA-S, and SHBG] had been also investigated. INSL3 levels were significantly higher in PCOD groups (A) and (B) compared to the healthy fertile control subgroup (C) (80.5 ± 29.4, 65.11 ± 15.6, and 41.11 ± 10.2 pg/mL, respectively), and was highest in group (A). Moreover, we identified a strong correlation between INSL3 and androstenedione (r = 0.42, p = 0.0012), and free (r = 0.42, p = .0123) and total testosterone (r = 0.41, p = .004) in the PCOD (A) and (B) subgroup compared to the levels in subgroup (C). LH was significantly higher in all PCOD women in groups (A&B) (12. 3 ± 3.4, and 11.2 ± 1.4 mIU/L, respectively) compared to those in group (A) (5.7 ± 2.5 mIU/L), with a fair correlation with INSL3. However, there was no statistically significant correlation between INSL3 and FSH, DHEA-S, glucose, basal insulin concentration or HOMA-IR in all PCOD women. The strong positive correlation between INSL3, and high ovarian androgens levels in all PCOD women, which appeared clearly in undescended polycystic ovaries could support the proposed syndrome hypothesis between those abnormal findings.

Expression profiles of mRNA and long noncoding RNA in the ovaries of letrozole-induced polycystic ovary syndrome rat model through deep sequencing

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in reproductive-aged women. However, the exact pathophysiology of PCOS remains largely unclear. We performed deep sequencing to investigate the mRNA and long noncoding RNA (lncRNA) expression profiles in the ovarian tissues of letrozole-induced PCOS rat model and control rats. A total of 2147 mRNAs and 158 lncRNAs were differentially expressed between the PCOS models and control. Gene ontology analysis indicated that differentially expressed mRNAs were associated with biological adhesion, reproduction, and metabolic process. Pathway analysis results indicated that these aberrantly expressed mRNAs were related to several specific signaling pathways, including insulin resistance, steroid hormone biosynthesis, PPAR signaling pathway, cell adhesion molecules, autoimmune thyroid disease, and AMPK signaling pathway. The relative expression levels of mRNAs and lncRNAs were validated through qRT-PCR. LncRNA-miRNA-mRNA network was constructed to explore ceRNAs involved in the PCOS model and were also verified by qRTPCR experiment. These findings may provide insight into the pathogenesis of PCOS and clues to find key diagnostic and therapeutic roles of lncRNA in PCOS.

Anti-Müllerian Hormone and Inhibin-A, but not Inhibin-B or Insulin-Like Peptide-3, may be Used as Surrogates in the Diagnosis of Polycystic Ovary Syndrome in Adolescents: Preliminary Results

OBJECTIVE

Polycystic ovary syndrome (PCOS) is a common endocrine problem in adolescents with an increasing prevalence of 30%. Pursuing new biomarkers with high specificity and sensitivity in the diagnosis of PCOS in adolescents is currently an active area of research. We aimed to investigate the diagnostic value of anti-Müllerian hormone (AMH), insulin-like peptide-3 (INSL3), inhibin-A (INH-A), and inhibin-B (INH-B) in adolescents with PCOS and also to determine the association, if any, between these hormones and clinical/laboratory findings related with hyperandrogenism.

METHODS

The study group comprised 53 adolescent girls aged between 14.5 and 20 years who were admitted to our outpatient clinic with symptoms of hirsutism and/or irregular menses and diagnosed as having PCOS in accordance with the Rotterdam criteria. Twenty-six healthy peers, eumenorrheic for at least two years and body mass index-matched, constituted the controls. Fasting blood samples for hormones [luteinizing hormone (LH), follicle-stimulating hormone (FSH), dehydroepiandrosterone-sulfate (DHEAS), androstenedione (D4-A), total/free testosterone (T/fT), sex hormone binding globulin (SHBG), AMH, INSL3, INH-A, INH-B] were drawn after an overnight fast.

RESULTS

In the PCOS group, 83% of the subjects were oligomenorrheic/amenorrheic and 87% had hirsutism. The LH, LH/FSH ratio, total T, fT, free androgen-index (FAI), DHEAS levels were significantly higher (p=0.005, p=0.042, p=0.047, p<0.001, p=0.007, p=0.014, respectively) and SHBG was significantly lower (p=0.004) in PCOS patients as compared to the controls. Although the INSL-3 and INH-B levels showed no difference between the groups (p>0.05), AMH and INH-A levels were found to be significantly higher in the PCOS group compared to the controls (p<0.001, p<0.001, respectively). In multiple linear regression analysis, WC SDS (p=0.028), logD4-A (p=0.033), logSHBG (p=0.031), and total ovarian volume (p=0.045) had significant effects on AMH levels, and LH (p=0.003) on INH-A levels. In receiver-operating characteristic analysis, the cut-off values for AMH and INH-A were 6.1 ng/mL (sensitivity 81.1%) and 12.8 pg/mL (sensitivity 86.8%), respectively, to diagnose PCOS. When AMH and INH-A were used in combination, the sensitivity (96.2%) increased.

CONCLUSION

INSL3 and INH-B were not found to have diagnostic value in adolescents with PCOS. On the other hand, it was shown that INH-A could be used as a new diagnostic biomarker in addition to AMH.

Role of ACTH in the Interactive/Paracrine Regulation of Adrenal Steroid Secretion in Physiological and Pathophysiological Conditions

In the normal human adrenal gland, steroid secretion is regulated by a complex network of autocrine/paracrine interactions involving bioactive signals released by endothelial cells, nerve terminals, chromaffin cells, immunocompetent cells, and adrenocortical cells themselves. ACTH can be locally produced by medullary chromaffin cells and is, therefore, a major mediator of the corticomedullary functional interplay. Plasma ACTH also triggers the release of angiogenic and vasoactive agents from adrenocortical cells and adrenal mast cells and, thus, indirectly regulates steroid production through modulation of the adrenal blood flow. Adrenocortical neoplasms associated with steroid hypersecretion exhibit molecular and cellular defects that tend to reinforce the influence of paracrine regulatory loops on corticosteroidogenesis. Especially, ACTH has been found to be abnormally synthesized in bilateral macronodular adrenal hyperplasia responsible for hypercortisolism. In these tissues, ACTH is detected in a subpopulation of adrenocortical cells that express gonadal markers. This observation suggests that ectopic production of ACTH may result from impaired embryogenesis leading to abnormal maturation of the adrenogonadal primordium. Globally, the current literature indicates that ACTH is a major player in the autocrine/paracrine processes occurring in the adrenal gland in both physiological and pathological conditions.

The Polycystic Ovary Morphology-Polycystic Ovary Syndrome Spectrum

BACKGROUND

Polycystic ovary syndrome (PCOS) is the most common cause of chronic hyperandrogenic anovulation. Two-thirds of PCOS patients have functionally typical PCOS, with typical functional ovarian hyperandrogenism manifest as 17-hydroxyprogesterone hyper-responsiveness to gonadotropin stimulation. Most, but not all, of the remainder have atypical functional ovarian hyperandrogenism. Many asymptomatic volunteers with polycystic ovary morphology (PCOM) have similar abnormalities.

OBJECTIVE

The objective of this paper is to review the relationship of biochemical ovarian function to the clinical spectrum observed in PCOS and in normal volunteers with PCOM.

FINDINGS

Adolescents and adults with PCOS are similar clinically and biochemically. Ninety-five percent of functionally typical PCOS have classic PCOS, ie, hyperandrogenic anovulation with PCOM. In addition to having more severe hyperandrogenism and a greater prevalence of PCOM than other PCOS, they have a significantly greater prevalence of glucose intolerance although insulin resistance is similarly reduced. Half of normal-variant PCOM have PCOS-related steroidogenic dysfunction, which suggests a PCOS carrier state.

CONCLUSIONS

There is a spectrum of ovarian androgenic dysfunction that ranges from subclinical hyperandrogenemia in some normal-variant PCOM to severe ovarian hyperandrogenism in most classic PCOS. A minority of mild PCOS cases do not fall on this spectrum of ovarian androgenic dysfunction, but rather seem to have obesity as the basis of their hyperandrogenism, or, less often, isolated adrenal androgenic dysfunction. Half of normal-variant PCOM also do not fall on the PCOS spectrum, and some of these seem to have excessive folliculogenesis as a variant that may confer mild prolongation of the reproductive lifespan. Improved understanding of PCOM in young women is needed.

Anti-müllerian hormone and insulin-like 3 levels in healthy normal-weight ovulatory and anovulatory eumenorrheic late adolescent females: potential early biomarkers of ovarian dysfunction?

OBJECTIVE

The aim of this study was to evaluate differences in anti-müllerian hormone (AMH) and insulin-like 3 (INSL3) levels and their association with gonadotropin and ovarian steroid hormones, as expression of ovarian function, between healthy normal-weight ovulatory and anovulatory eumenorrheic late adolescent females.

STUDY DESIGN

This study analyzed AMH and INSL3 levels in forty healthy eumenorrheic late adolescent females (aged 16-19 ys), selected from a cross-sectional epidemiological study performed on the prevalence of hyperandrogenic states. The subjects were divided into ovulatory (n: 28) and anovulatory (n: 12) groups in accordance to a previous cluster analysis based on progesterone (P) distribution measured once in the latter part of the cycle. Both groups were compared for anthropometric, biochemical and hormonal parameters.

RESULTS

INSL3 and AMH were detectable in all samples. Testosterone (P=0.01), the free-androgen index (FAI) (P=0.051), gonadotropins (LH: P=0.02; FSH: P=0.004) and AMH (P=0.02) levels were significantly higher in the anovulatory group with respect to their ovulatory counterpart. A trend toward significantly higher INSL3 concentrations (P=0.08) was also shown in the anovulatory group. A positive correlation between INSL3 levels and androgens such as androstenedione (r=0.38; P=0.02), testosterone (r=0.44; P=0.004) and FAI (r=0.42; P=0.006) and a negative borderline significant correlation (r=-0.30; P=0.055) between AMH and P were shown in all subjects.

CONCLUSION

Healthy eumenorrheic late adolescent females with sporadic anovulation display higher AMH and INSL-3 blood concentrations in association with higher androgen levels compared with age- and BMI-matched subjects with ovulatory cycle, suggesting evidence of an earlier ovarian dysfunction.