The role of macrophages in polycystic ovarian syndrome and its typical pathological features: A narrative review

Fine particulate matter components and reproductive hormones in female adults: A 15-year longitudinal cohort study

BACKGROUND

Few cohort studies have evaluated the long-term impacts of ambient fine particulate matter (PM2.5) and its components on reproductive hormone levels in female adults.

METHODS

We conducted a 15-year retrospective cohort study in Taiwan between 2003 and 2017. The two-year average concentrations of PM2.5 and its components, including sulfate (SO42-), nitrate (NO3-), ammonium (NH4+), organic matter (OM), and black carbon (BC), were assessed at each participant's addresses. Linear mixed models were used to examine the associations of PM2.5 and its components with reproductive hormones, including follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone (T), estradiol (E2), and prolactin (PRL). Stratified analyses were conducted to identify vulnerable populations.

RESULTS

17,152 female adults were included. Each interquartile range (IQR: 3.545 μg/m3) increase in PM2.5 was associated with a 0.585 mIU/mL [95% confidence interval (CI): 0.190-0.980] increase in FSH levels. Among the five components of PM2.5, BC had the strongest positive association [each IQR (0.272 μg/m3) increase was associated with a 0.863 mIU/mL (95% CI: 0.476-1.250) increase in FSH levels], followed by OM, SO42-, and NH4+. Similar associations were found for LH, with a 0.483 mIU/mL (95% CI: 0.225-0.742) and 0.684 mIU/mL (95% CI: 0.431-0.938) increase in LH levels per IQR increase in PM2.5 and BC, respectively. The pollutants were marginally associated with decreased E2 levels and increased PRL levels. Non-linear associations between PM2.5 and its components and the levels of FSH, LH, E2, and PRL were observed. These pollutants were also positively associated with T levels among young adults. Post-menopausal women were more susceptible to the chronic impacts of PM2.5 and its components.

CONCLUSION

Our study highlighted the adverse impacts of long-term exposure to PM2.5 components on hormonal homeostasis, revealing the biological mechanism of air pollution-reproductive health associations in females. Implementing stringent control of air pollution levels can benefit reproductive health in female adults, even in moderately polluted regions.

Dissecting Causal Relationships Between Immune Cells, Plasma Metabolites, and PCOS: Evidence From Mediating Mendelian Randomization Analysis

Background

The relationship between Polycystic ovary syndrome (PCOS) and immune dysregulation, along with metabolic disturbances, remains unclear. This study used Mendelian Randomization (MR) to investigate causal relationships between immune cells, PCOS, and possible metabolite mediators.

Methods

We explored the genetic-level relationship between immune cells and PCOS, focusing on metabolites as potential mediators. Data from genome-wide association studies (GWAS) included 731 immune cell types (n=3757), 1400 plasma metabolites (n=8299), and PCOS cases (n=797) versus controls (n=140,558). Bidirectional MR analysis examined immune-PCOS relationships, while two-step MR and mediation analysis identified metabolites as potential mediators. The inverse variance-weighted (IVW) method was used for primary causal assessment, with sensitivity analysis validating results.

Results

We identified a total of 33 immune cells that were associated with increased or decreased risk of PCOS (P < 0.05), and these immune cells were also associated with alterations in certain metabolite levels (P < 0.05). Among them, 12 immune cells were found to influence the occurrence of PCOS through the mediation of 17 metabolites. Notably, the effects of Myeloid DC %DC, NKT AC, CD20 on CD20- CD38-, CD25 on memory B cell, and HLA DR on CD33dim HLA DR+ CD11b+ were mediated by multiple metabolites on PCOS development. Similarly, histidine betaine (hercynine) levels and alpha-ketoglutarate to ornithine ratio mediated the association of more than one immune cell with PCOS.

Conclusion

This study highlights 12 immune cells impacting PCOS through 17 metabolites, advancing the understanding of immune mechanisms in PCOS risk and suggesting potential therapeutic approaches targeting immune modulation.

Macrophages: a double-edged sword in female reproduction and disorders

Reproduction consists of sequential inflammation-like events, primarily within the endometrium, from ovulation to embryo implantation, decidualization and delivery. During the reproductive cycle, the endometrium repeatedly undergoes cyclic periods of proliferation, differentiation, tissue breakdown and repair without scarring. Owing to their phagocytic activity, macrophages, key players in innate immunity, are thought to play crucial roles in the endometrium. Endometrial macrophages actively participate in various stages of reproductive tissue remodeling, particularly during decidualization and pregnancy establishment. Traditionally considered simple bystanders that clear debris to prevent autoimmune responses in tissue homeostasis, macrophages are now recognized as main actors with broad functional plasticity that allows them to fine tune the balance between pro- and anti-inflammatory responses during tissue inflammation, remodeling and repair. Homeostatic balance is determined by the sum of various mediators produced by two distinctly polarized macrophage subpopulations. The biased polarization of tissue-resident macrophages may contribute to the pathogenesis of various diseases, such as inflammation and cancer. Thus, understanding how macrophages contribute to endometrial homeostasis is crucial for deciphering the underlying mechanisms of various reproductive disorders. Nanomedicines using extracellular vesicles, nanoparticles and noncoding RNAs have recently been applied to modulate macrophage polarization and alleviate disease phenotypes. Despite these advances, the functions of endometrial macrophages under physiological and pathophysiological conditions remain poorly understood, which complicates the development of targeted therapies. Here we update the current understanding of the homeostatic function of macrophages and the putative contribution of endometrial macrophage dysfunction to reproductive disorders in women, along with innovative molecular therapeutics to resolve this issue.

PTX3 impairs granulosa cell function by promoting the secretion of inflammatory cytokines in M1 macrophages via the JAK pathway

Polycystic Ovary Syndrome (PCOS) is an endocrine disorder syndrome among women in their reproductive years and is often linked to chronic inflammation. Pentraxin 3 (PTX3), a member of the pentraxin protein family, plays a key role in inflammation. In our study, we explored whether PTX3 influences granulosa cell function via its involvement in inflammation. Our analysis revealed elevated PTX3 concentrations in the follicular fluid and granulosa cells of patients with PCOS. Overexpression of PTX3 promoted apoptosis in the cultured murine granulosa cell line KK1 and inhibited the proliferation of these cells. Additionally, it suppressed the expression of luteinizing hormone receptor (LHR) and follicle-stimulating hormone receptor (FSHR), as well as those of key enzymes involved in steroid hormone synthesis, CYP19A1, and HSD3β, leading to reduced secretion of estradiol and progesterone. Moreover, both recombinant PTX3 protein and PTX3 secreted by granulosa cells (GCs) promoted the secretion of inflammatory cytokines IL-1β, IL-6, and TNF-α by M1 macrophages via the JAK pathway, which impaired the function of granulosa cells. This study may advance the understanding of cell-cell interactions in follicles and the inflammatory factors that contribute to PCOS pathophysiology.

The Circadian Rhythm Regulates the Hepato-ovarian Axis Linking Polycystic Ovary Syndrome and Non-alcoholic Fatty Liver Disease

This study aimed to identify shared gene expression related to circadian rhythm disruption in polycystic ovary syndrome (PCOS) and non-alcoholic fatty liver disease (NAFLD) to discover common diagnostic biomarkers. Visceral fat RNA samples were collected from 12 PCOS and 14 non-PCOS patients, a sample size representing the clinical situation and sufficient to capture PCOS gene expression profiles. Along with liver transcriptome profiles from NAFLD patients, these data were analyzed to identify crosstalk circadian rhythm-related genes (CRRGs) between the diseases. Single-sample and single-gene gene set enrichment analyses explored immune infiltration and pathways associated with CRRGs. Diagnostic biomarkers were identified using a random forest algorithm and validated through nomograms and a mouse model. Seven crosstalk CRRGs (FOS, ACHE, FOSB, EGR1, NR4A1, DUSP1, and EGR3) were associated with clinical features, immunoinflammatory microenvironment, and metabolic pathways in both diseases. EGR1, DUSP1, and NR4A1 were identified as diagnostic biomarkers, exhibiting robust diagnostic capacity (AUC = 0.7679 for PCOS, AUG = 0.9981 for NAFLD). Nomogram validation showed excellent calibration, and independent datasets confirmed their discriminatory ability (AUC = 0.6528 for PCOS, AUC = 0.8275 for NAFLD). Additionally, ceRNA networks and androgen receptor binding sites were identified, suggesting their regulatory roles. Mouse model validation confirmed significant downregulation of EGR1, DUSP1, and NR4A1 in liver tissues, consistent with sequencing data. This study identifies crosstalk CRRGs and diagnostic biomarkers shared between PCOS and NAFLD, highlighting their roles in immune and metabolic dysregulation. These biomarkers offer the potential for improving diagnosis and guiding targeted treatments for both diseases.

Altered Immune Cell Profiles in the Follicular Fluid of Patients with Poor Ovarian Response According to the POSEIDON Criteria

Objective

This study aims to investigate alterations in immune cell counts within preovulatory follicles of patients with poor ovarian response (POR) during assisted reproductive technology (ART), classified according to the POSEIDON criteria.

Methods

This single-centre cross-sectional study included 543 women undergoing IVF/ICSI treatment, selected based on specific inclusion and exclusion criteria: 292 with normal ovarian response and 251 with poor response. Follicular fluid (FF) was collected on the day of oocyte retrieval and analysed by flow cytometry to determine the proportions of macrophages (Mφs), M1 and M2 Mφs, T cells (CD4 and CD8 T cells), dendritic cells (DCs), including type 1 conventional dendritic cells (cDC1) and type 2 conventional dendritic cells (cDC2), and neutrophils. Multivariable logistic regression assessed the relationship between immune cell counts and POR, Pearson correlation determined associations with the number of retrieved oocytes, and receiver operating characteristic (ROC) curves evaluated the predictive power of immune cell counts for POR.

Results

Immune cells accounted for 52.57% (±23.90%) of the total cell population in the follicular microenvironment, which was approximately equal to that of granulosa cells, with Mφs being the most abundant, followed sequentially by T cells, DCs, and neutrophils. In patients with POR, overall Mφs infiltration in the follicular microenvironment decreased, whereas M1 and M2 polarization increased. T cell infiltration increased, with a decrease in the CD4/CD8 ratio. Both cDC1 and cDC2 were significantly elevated. Moreover, multivariable logistic regression revealed that the total macrophage count, CD4 T cell count, and cDC2 count were independent predictors of POR. Notably, cDC2 showed the largest area under the ROC curve, suggesting its strong potential as a biomarker for predicting POR.

Conclusion

The proportion of immune cells in preovulatory follicles were significantly altered in patients with POR. These findings suggest that immune cell dynamics in the follicular microenvironment may play a crucial role in determining ovarian response and prognosis, indicating that targeted immunomodulatory strategies could be considered in future therapeutic approaches.

Genetically predicted serum metabolites mediate the association between inflammatory proteins and polycystic ovary syndrome: a Mendelian randomization study

Objective

To investigate the association between polycystic ovary syndrome (PCOS) and inflammatory proteins, and to identify and quantify the role of serum metabolites as potential mediators.

Methods

Utilizing summary-level data from a genome-wide association study (GWAS), we conducted a two-sample Mendelian Randomization (MR) analysis, a genetic approach that uses genetic variants as instrumental variables to assess the causal relationships between risk factors and outcomes. This analysis involved genetically predicted PCOS (1,639 cases and 218,970 controls) and inflammatory proteins (14,824 participants of primarily European descent). Additionally, a two-step MR analysis was performed to quantify the proportion of the effect of serum metabolites-mediated inflammatory proteins on PCOS. The Inverse Variance Weighted (IVW) method, a statistical technique used within MR to combine data from multiple genetic variants, was used to estimate the causal effects.

Results

The IVW method revealed that the inflammatory proteins IFN-γ (p-value = 0.037, OR = 1.396, 95% CI = 1.020-1.910) and CCL7 (p-value = 0.033, OR = 1.294, 95% CI = 1.021-1.641) were associated with an increased risk of PCOS, while IL-6 (p-value = 0.015, OR = 0.678, 95% CI = 0.495-0.929) and MMP-10 (p-value = 0.025, OR = 0.753, 95% CI = 0.587-0.967) were associated with a decreased risk. No significant evidence suggested an effect of genetically predicted PCOS on inflammatory proteins. The serum metabolite X-11444 was found to mediate 5.44% (95% CI: 10.8-0.0383%) of the effect of MMP-10 on PCOS.

Conclusion

This study not only introduces novel causal associations between inflammatory proteins and PCOS but also highlights the mediating role of serum metabolites in these associations. By applying MR, we were able to minimize confounding and reverse causality, offering robust insights into the biological mechanisms underlying PCOS. These findings advance the understanding of PCOS pathogenesis, particularly in relation to inflammatory pathways and serum metabolite interactions, and suggest potential therapeutic targets that could inform future clinical interventions aimed at mitigating inflammation-related PCOS risks.

Correlation between acupuncture dose and pregnancy outcomes in women with polycystic ovary syndrome undergoing in vitro fertilization-embryo transfer: a systematic review

BACKGROUND

Increasing studies focused on the efficacy of acupuncture on pregnancy outcomes in patients with polycystic ovary syndrome (PCOS) undergoing in vitro fertilization-embryo transfer (IVF-ET). However, debatable conclusions have been drawn from different randomized controlled trials (RCTs), which might be related to different doses of acupuncture.

OBJECTIVE

To evaluate whether acupuncture has a dose-dependent effect on pregnancy outcomes in patients with PCOS undergoing IVF-ET in systematically reviewing.

METHODS

Seven electronic databases were searched from inception to October 10th, 2024. The Cochrane Collaboration's tool ROB 2.0 (ROB 2.0) provided an assessment for the risk of bias. The acupuncture dose was extracted, then categorized into high, medium, and low dose according to the scoring system results, the evidence was assessed by Slavin's qualitative best-evidence synthesis approach in a rigours methodological way. Clinical pregnancy rate (CPR) was regarded as the primary outcome.

RESULTS

A total of 953 subjects met the eligibility criteria in 12 RCTs were included, among which two studies were low dose, four were medium dose, and six were high dose. The overall quality of included studies was low, 50.00% (6/12) studies were low risk, 16.67% (2/12) studies were some concerns, and 33.33% (4/12) studies were high risk. Comparing the results, the consistent high-dose result among high-quality trials provides strong evidence for a positive correlation between high-dose acupuncture and pregnancy outcomes.

CONCLUSION

A trend indicates that higher acupuncture doses yield better outcomes for PCOS patients undergoing IVF-ET. Further confirmation through direct comparisons of different doses was needed.

TRIAL REGISTRATION

The systematic review has been registered on PROSPERO ( https://www.crd.york.ac.uk/prospero/ ), and the registration number is CRD42023400187.

Analysis of macrophage polarization and regulation characteristics in ovarian tissues of polycystic ovary syndrome

Background

Polycystic ovary syndrome (PCOS) can lead to infertility and increase the risk of endometrial cancer. Analyzing the macrophage polarization characteristics in ovarian tissues of PCOS is crucial for clinical treatment.

Methods

We obtained 13 PCOS and nine control ovarian samples from the CEO database and analyzed differentially expressed genes (DEGs). Macrophage polarization-related genes (MPRGs) were sourced from the GeneCards and MSigDB databases. Intersection of DEGs with MPRGs identified DEGs associated with macrophage polarization (MPRDEGs). Gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Protein-protein interaction (PPI) Network analysis were conducted on MPRDEGs. Moreover, the top 10 genes from three algorithms were identified as the hub genes of MPRGs. In addition, miRNAs, transcription factors (TFs), and drugs were retrieved from relevant databases for regulatory network analysis of mRNA-miRNA, mRNA-TF, and mRNA-Drug interactions. Immune cell composition analysis between the PCOS and control groups was performed using the CIBERSORT algorithm to calculate correlations across 22 immune cell types.

Results

A total of 13 PCOS samples and nine control ovarian samples were obtained in this study. We identified 714 DEGs between the two groups, with 394 up-regulated and 320 down-regulated. Additionally, we identified 774 MPRGs, from which we derived 30 MPRDEGs by intersecting with DEGs, among which 21 exhibited interaction relationships. GO and KEGG analyses revealed the enrichment of MPRDEGs in five biological processes, five cell components, five molecular functions, and three biological pathways. Immune infiltration analysis indicated a strong positive correlation between activated nature killer (NK) cells and memory B cells, while neutrophils and monocytes showed the strongest negative correlation. Further investigation of MPRDEGs identified nine hub genes associated with 41 TFs, 82 miRNAs, and 44 drugs or molecular compounds. Additionally, qRT-PCR results demonstrated overexpression of the CD163, TREM1, and TREM2 genes in ovarian tissues from the PCOS group.

Conclusion

This study elucidated the polarization status and regulatory characteristics of macrophages in ovarian tissues of the PCOS subjects, confirming significant overexpression of CD163, TREM1, and TREM2. These findings contribute to a deeper understanding of the pathogenesis of PCOS.

Use of placental-derived mesenchymal stem cells to restore ovarian function and metabolic profile in a rat model of the polycystic ovarian syndrome

INTRODUCTION

Polycystic ovary syndrome (PCOS) is an endocrine and metabolic disturbance that affects many women worldwide and is characterized by chronic anovulation, hyperandrogenism, and ovarian dysfunction. Placenta-derived mesenchymal stem cells (PDMSCs) are derived from the placenta and have advantages over other sources of MSCs in terms of availability, safety, and immunomodulation.

MATERIALS AND METHODS

In this experimental study, twenty female Wistar rats were assigned to four groups (n = 5) including control, sham, PCOS, and PCOS+PDMSCs groups. Then, PCOS was induced in the rats through administering letrozole for 21 days. PDMSCs (1 × 106 cells) were injected through the tail vein. Fourteen days after the cell infusion, evaluation was performed on the number of healthy follicles, corpus luteum, and cystic follicles as well as the levels of testosterone, follicle-stimulating hormone (FSH), luteinizing hormone (LH), fasting blood glucose, fasting insulin, and insulin resistance. Moreover, the serum levels of cholesterol, triglyceride (TG), high-density lipoprotein (HDL), and low-density lipoprotein (LDL) were measured. Liver function was also determined by the evaluation of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels.

RESULTS

The number of corpus luteum and primordial, primary, secondary, and antral follicles was significantly elevated in the PCOS+PDMSCs group compared to the PCOS group. However, the number of cystic follicles significantly decreased in the PCOS+PDMSCs group. The LH and testosterone levels also decreased significantly, while FSH levels increased significantly in the PCOS+PDMSCs group. The levels of fasting blood glucose, fasting insulin, and insulin resistance notably decreased in the PCOS+PDMSCs group. Moreover, the lipid profile improved in the PCOS+PDMSCs group along with a significant decrease of cholesterol, LDL, and TG and an increase in HDL. The PCOS+PDMSCs group exhibited marked decreases in the AST and ALT levels as well.

CONCLUSION

The results of this study suggest that PDMSCs are a potential treatment option for PCOS because they can effectively restore folliculogenesis and correct hormonal imbalances, lipid profiles and liver dysfunction in a rat model of PCOS. However, further research is needed to establish the safety and effectiveness of PDMSCs for treating PCOS.

Mesencephalic astrocyte-derived neurotrophic factor ameliorates inflammatory response in polycystic ovary syndrome via inhibiting TLR4-NF-κB-NLRP3 pathway

Polycystic ovary syndrome (PCOS) is a common reproductive endocrine disorder in women of reproductive age, which often leads to female infertility. Chronic inflammation is a significant factor in the development of PCOS. Our study aimed to explore the impact of mesencephalic astrocyte-derived neurotrophic factor (MANF), a scientifically validated anti-inflammatory factor, on 99 diagnosed PCOS patients. We also investigated its effects on PCOS mice induced with dehydroepiandrosterone (DHEA) and KGN cells induced with dihydrotestosterone (DHT). Our findings revealed a decrease in serum MANF levels in PCOS patients, which were negatively associated with serum tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) levels. The administration of recombinant human MANF (rhMANF) in PCOS mice demonstrated a decrease in pro-inflammatory cytokines and monocytes/macrophages in both peripheral blood and ovarian tissues. Furthermore, the inclusion of rhMANF notably ameliorated DHEA-induced ovarian dysfunction and fibrosis by negatively regulating the toll-like receptor 4 (TLR4)-nuclear factor kappa B (NF-κB)-NLR family, pyrin domain containing protein 3 (NLRP3) pathway. Additionally, in vitro experiments showed that the up-regulation of MANF offset DHT-induced inhibition of viability and apoptosis in KGN cells. Collectively, this study highlights the anti-inflammatory properties of MANF in PCOS and suggests its potential as a therapeutic approach for the management of PCOS.

Pulsed Low-Intensity Focused Ultrasound (LIFU) Activation of Ovarian Follicles

Objective: A biological system's internal morphological structure or function can be changed as a result of the mechanical effect of focused ultrasound. Pulsed low-intensity focused ultrasound (LIFU) has mechanical effects that might induce follicle development with less damage to ovarian tissue. The potential development of LIFU as a non-invasive method for the treatment of female infertility is being considered, and this study sought to explore and confirm that LIFU can activate ovarian follicles. Results: We found a 50% increase in ovarian weight and in the number of mature follicles on the ultrasound-stimulated side with pulsed LIFU and intraperitoneal injection of 10 IU PMSG in 10-day-old rats. After ultrasound stimulation, the PCOS-like rats had a decrease in androgen levels, restoration of regular estrous cycle and increase in the number of mature follicles and corpora lutea, and the ratio of M1 and M2 type macrophages was altered in antral follicles of PCOS-like rats, consequently promoting further development and maturation of antral follicles. Conclusion: LIFU treatment could trigger actin changes in ovarian cells, which might disrupt the Hippo signal pathway to promote follicle formation, and the mechanical impact on the ovaries of PCOS-like rats improved antral follicle development.