Decoding the Epigenetics of Infertility: Mechanisms, Environmental Influences, and Therapeutic Strategies.

Infertility is a complex condition caused by a combination of genetic, environmental, and lifestyle factors. Recent advances in epigenetics have highlighted the importance of epigenetic changes in fertility regulation. This review aims to provide a comprehensive overview of the epigenetic mechanisms involved in infertility, with a focus on DNA methylation, histone modification, and non-coding RNAs. We investigate the specific epigenetic events that occur during gametogenesis, with a focus on spermatogenesis and oogenesis as distinct processes. Furthermore, we investigate how environmental factors such as diet, stress, and toxin exposure can influence these epigenetic changes, potentially leading to infertility. The second part of the review explores epigenetic changes as therapeutic targets for infertility. Emerging therapies that modulate epigenetic marks present promising opportunities for fertility restoration, particularly in spermatogenesis. By summarizing current research findings, this review emphasizes the importance of understanding epigenetic contributions to infertility. Our discussion aims to lay the groundwork for future research directions and clinical applications in reproductive health.

Non-genetic physicians' knowledge, attitudes and behavior towards medical genetics.

To examine the knowledge, behavior, and attitudes toward medical genetics among obstetrics and gynecology, pediatrics, and neurology residents and specialists, who encounter the highest number of patients with specific genetic disorders, in their everyday practice. The cross-sectional study involved 182 nongenetic residents and specialists in the Republic of Croatia, who completed a validated online questionnaire anonymously and voluntarily. The questionnaire consisted of five groups of questions: general information, knowledge, behavior in practice, attitude toward genetic testing, and additional education in medical genetics. The median score for overall knowledge of medical genetics was 70.2% among obstetrician-gynecologists, 80.5% among pediatricians, and 76.7% among neurologists (P < 0.001, lowest median in obstetrician-gynecologists). When asked about their behavior in daily practice, around 90% of respondents admitted the possibility of not recognizing patients with genetic disorders, which is why more than 90% emphasized the need for additional education in medical genetics. In addition, the respondents showed a positive attitude toward genetic testing, but they did not feel educated enough to interpret the results of genetic testing. The results highlight the need for further genetic education of non-genetic health professionals, which would lead to greater confidence and ability to recognize patients with genetic disorders, select the appropriate genetic testing method and achieve more efficient communication with patients.

An association between PPARα-L162V polymorphism and increased plasma LDL cholesterol levels after risperidone treatment.

Peroxisome proliferator-activated receptor alpha (PPARα) and antipsychotic medications both influence polyunsaturated fatty acids (PUFA) homeostasis, and thus PPARα polymorphism may be linked to antipsychotic treatment response. Here we investigated whether the functional leucine 162 valine (L162V) polymorphism in PPARα influenced antipsychotic treatment in a group of psychosis patients (N = 186), as well as in a patient subgroup with risperidone, paliperidone, or combination treatment (N = 65). Antipsychotic-naïve first-episode patients and nonadherent chronic individuals were genotyped by polymerase chain reaction analysis. At baseline, and after 8 weeks of treatment with various antipsychotic medications, we assessed the patients' Positive and Negative Syndrome Scale (PANSS) scores; PANSS factors; and metabolic syndrome-related parameters, including fasting plasma lipid and glucose levels, and body mass index. In the total patient group, PPARα polymorphism did not affect PANSS psychopathology or metabolic parameters. However, in the subgroup of patients with risperidone, paliperidone, or combination treatment, PPARα polymorphism influenced changes in plasma LDL cholesterol. Specifically, compared to PPARα-L162L homozygous patients, PPARα-L162V heterozygous individuals exhibited significantly higher increases of LDL cholesterol levels after antipsychotic treatment. The PPARα polymorphism had a strong effect size, but a relatively weak contribution to LDL cholesterol level variations (∼12.8 %).

Association between Insertion-Deletion Polymorphism of the Angiotensin-Converting Enzyme Gene and Treatment Response to Antipsychotic Medications: A Study of Antipsychotic-Naïve First-Episode Psychosis Patients and Nonadherent Chronic Psychosis Patients.

We investigated whether a functional insertion/deletion (I/D) polymorphism of angiotensin-converting enzyme (ACE) influenced antipsychotic treatment. At baseline, and after 8 weeks of treatment with various antipsychotic medications, we assessed patients' Positive and Negative Syndrome Scale (PANSS) scores, PANSS factors, and metabolic-syndrome-related parameters (fasting plasma lipid and glucose levels, and body mass index). A total of 186 antipsychotic-naïve first-episode psychosis patients or nonadherent chronic psychosis individuals (99 males and 87 females) were genotyped by polymerase chain reaction analysis. The ACE-I/D polymorphism was significantly associated with changes in PANSS psychopathology only (p < 0.05). Compared to ACE-II homozygous males, ACE-DD homozygous and ACE-ID heterozygous males manifested significantly greater decreases in PANSS positive score, PANSS excitement factor, and PANSS cognitive factor. ACE-DD homozygous females manifested higher decreases in PANSS depression factor compared to ACE-II homozygous and ACE-ID heterozygous females. The polymorphism's effect size was estimated as moderate to strong, while its contribution to the PANSS psychopathology ranged from ~5.4 to 8.7%, with the lowest contribution observed for PANSS positive score changes and the highest for PANSS depressive factor changes. Our results indicate that ACE-I/D polymorphism had a statistically significant but weak gender-specific impact on psychopathology data, and showed no association between ACE-I/D polymorphism and metabolic-syndrome-related parameters.

Genes for anti-Müllerian hormone and androgen receptor are underexpressed in human cumulus cells surrounding morphologically highly graded oocytes.

OBJECTIVES: The aim of this study was to investigate the expression of genes crucial for the quality of the oocyte and whether expression levels of these genes in cumulus cells can be biological markers for the quality of the oocyte, zygote or embryo, or even for achievement of pregnancy after the assisted reproductive technology procedure. We examined the expression profile of the anti-Müllerian hormone (AMH) gene and its respective receptors: anti-Müllerian hormone receptor type 2 (AMHR2), follicle-stimulating hormone receptor (FSHR) and androgen receptor (AR) in cumulus cells (CCs) surrounding the oocyte, as well as AMH concentrations in follicular fluid of the associated follicle. The obtained gene expression levels were correlated with the morphological quality of the associated oocyte, zygote and embryo as well as with assisted reproductive technology outcome following the intracytoplasmic sperm injection procedure. METHODS: This study involved 129 cumulus cells and 35 follicular fluid samples, taken from 58 patients undergoing the intracytoplasmic sperm injection procedure. Oocytes, zygotes and embryos were assessed for morphological quality. The relative gene expression of AMH, AMHR2, FSHR and AR was calculated using the delta-delta Ct method. Anti-Müllerian hormone concentrations in follicular fluids were measured by enzyme-linked immunosorbent assay. RESULTS: The results yielded suggest a relationship between AMH, AR and oocyte morphology: AMH and AR gene expression levels in CCs surrounding morphologically optimal oocytes were significantly lower than in CCs surrounding oocytes with suboptimal morphology (p = 0.011 and p = 0.008, respectively). Statistically significant positive correlation was found between mRNA expression levels of AMH and FSHR (p < 0.001), AMH and AR (p = 0.001), AMHR2 and FSHR (p < 0.001), AMHR2 and AR (p < 0.001), as well as between FSHR and AR (p < 0.001). CONCLUSION: Assessed results point to AMH and AR relation with oocyte maturity, but not with its fertilization potential, or with embryo quality.

Matrix metalloproteinase and tissue inhibitors of metalloproteinases gene polymorphisms in disorders that influence fertility and pregnancy complications: A systematic review and meta-analysis.

Matrix metalloproteinase (MMP) and tissue inhibitors of metalloproteinase (TIMP) gene polymorphisms have been extensively evaluated as predisposing factors to human reproductive disorders. However, the evidence available is inconsistent. Therefore, we performed a systematic review and meta-analysis to provide the first comprehensive synopsis of case-control studies that investigated the association of MMP and TIMP gene polymorphisms with disorders that influence fertility and pregnancy complications. Literature search was performed using PubMed and Scopus databases. We included 42 case-control studies in the systematic review for the following disorders: adenomyosis, endometriosis, hypertensive disorders of pregnancy, preterm birth and recurrent spontaneous abortion. Although a large number of MMP and TIMP gene polymorphisms were tested, no exclusive and unambiguous risk factors were identified for any of the disorders. The majority of statistically significant associations were confirmed in just one study. Additionally, we performed two meta-analyses for MMP9 rs3918242 polymorphism in endometriosis/adenomyosis and preeclampsia but found no association with either disorder. Considering the modest associations and conflicting results between individual case-control studies, new data is needed for further research of this subject.

A polymorphic GGC repeat in the NPAS2 gene and its association with melanoma.

Circadian clock regulation in mammals is controlled by feedback loops of a set of circadian genes. One of these circadian genes, NPAS2, encodes for a member of the bHLH-PAS class of transcription factors and is expressed in the forebrain and in some peripheral organs such as liver and skin. Other biological processes are also regulated by circadian genes. For example, NPAS2 is involved in cell proliferation, DNA damage repair and malignant transformation. Aberrant expression of clock genes has been previously observed in melanoma which led to our effort to sequence the NPAS2 promoter region in this cancer type. The NPAS2 putative promoter and 5' untranslated region of ninety-three melanoma patients and ninety-six control subjects were sequenced and several variants were identified. Among these is a novel microsatellite comprising a GGC repeat with different alleles ranging from 7 to 13 repeats located in the 5' untranslated exon. Homozygosity of an allele with nine repeats (9/9) was more prevalent in melanoma than in control subjects (22.6% and 13.5%, respectively, P: 0.0206) suggesting that some NPAS2 variants might contribute to melanoma susceptibility. Impact statement This report describes a variable microsatellite repeat sequence located in the 5' untranslated exon of NSPAS2, a gene encoding a clock transcription factor. Significantly, this study is the first to show that a variant copy number GGC repeat sequence in the NPAS2 clock gene associates with melanoma risk and which may be useful in the assessment of melanoma predisposition.

Tumor necrosis factor-alpha gene promoter -308 and -238 polymorphisms in patients with lung cancer as a second primary tumor.

BACKGROUND: Lung cancer is the most common second primary cancer. We investigated whether the TNF-alpha-308 and TNF-alpha-238 polymorphisms were associated with the susceptibility and severity of lung cancer as the second primary cancer (LC2). MATERIAL/METHODS: This study included 104 patients from the group LC2. The control subjects included 2 groups. The first control group (LC1) comprised 201 unrelated patients with lung cancer as a first primary cancer. The second control group (HC) comprised 230 healthy blood donors, matched for sex and age to the study group. RESULTS: The frequencies of the TNF-alpha-238 polymorphism GG genotype and the G allele were higher in the LC2 group than in the LC1 group, but the differences did not reach significance (p=0.054 and p=0.057, respectively). Similar differences were found in the TNF-alpha-238 polymorphism GG genotype and G allele between the LC2 group and the HC group (p=0.054 and p=0.057, respectively). In terms of the different types of lung cancer, patients with a second primary NSCLC (non-small cell lung cancer) more frequently had TNF-alpha-238 polymorphism GG genotypes and G alleles than patients with a first primary NSCLC (the differences approached statistical significance: p=0.060, p=0.064, respectively). All (100%) patients of group LC2 (n=104) had the GG genotype and the G allele. GG genotype was exclusive and no A allele was found in group LC2. CONCLUSIONS: TNF-alpha-238 polymorphism GG genotype and the G allele could have a promotional effect on the development of NSCLC in the group of patients with LC2.

Angiotensin-converting enzyme insertion/deletion gene polymorphism in lung cancer patients.

Lung cancer is a complex disease, and many factors, including environmental and occupational exposure, cigarette smoking, and genetics, contribute to its progression. Angiotensin-converting enzyme (ACE) is an important regulator of blood pressure and cardiovascular homeostasis. Plasma levels of ACE depend on an insertion/deletion (I/D) polymorphism in its gene. Current correlation data between lung cancer and the ACE I/D polymorphism are contradictory or insufficient. We investigated whether the ACE I/D polymorphism is associated with a risk for lung cancer development in the Croatian population, representing the first report in a population of Slavic origin. A total of 308 lung cancer patients and 353 control subjects were genotyped for the ACE I/D polymorphism by polymerase chain reaction. The observed distribution of genotypes and alleles showed no significant difference between total patients and controls (p>0.050). However, in a subgroup of nonsmall cell lung cancer patients with squamous cell carcinoma, a significantly higher frequency of the DD genotype (37.7% vs. 27.8%, p=0.030, OR=1.57, 95% CI=1.05-2.36) and D allele was observed compared with the control group (61.3% vs. 52.8%, p=0.015, OR=1.41, 95% CI=1.07-1.87). The DD genotype of ACE may contribute to a higher risk of developing squamous cell carcinoma in the Croatian population.