Serum miR-155 as a potential biomarker of male fertility.

STUDY QUESTION: Are serum levels of micro-RNAs miR-155 and miR-146a associated with male fertility, low-grade systemic inflammation (LGSI) and androgens? SUMMARY ANSWER: miR-155 was associated with male subfertility independent of LGSI or androgens while miR-146a was only weakly associated with subfertility and LGSI. WHAT IS KNOWN ALREADY: Male subfertility has been associated with LGSI as well as with androgen deficiency. miR-155 and miR-146a are central regulators of inflammation and their level in cells and in the serum has been associated with several inflammatory conditions. STUDY DESIGN, SIZE, DURATION: In this case-control study, two independent groups of 60 subjects each (exploratory and confirmatory cohort) were randomly selected from an ongoing study on subfertile men (in total: hypogonadal; n = 40, eugonadal; n = 40 and control group n = 39) at a University Hospital Reproductive Medicine Centre. Individuals were matched for age. PARTICIPANTS/MATERIALS, SETTING, METHODS: Total RNA was isolated from cell-free serum. As internal control a synthetic miRNA, UniSp6, was added to each sample prior to extraction. miRNA expression levels were measured by real-time RT-PCR and presented as fold difference (arbitrary units, U) from control. Sera from these individuals had been previously analyzed for hormone and cytokine levels. MAIN RESULTS AND THE ROLE OF CHANCE: Serum levels of miR-155 were associated with levels of miR-146a (P < 0.0001), but only miR-146a was associated with inflammatory markers. miR-155 was strongly associated with subfertility (for subfertile group 1.88 U, 95% confidence interval (CI) 1.6-2.1 U versus 1.15, 95% CI 1.0-1.2 U in controls; P = 0.001). Receiver operating characteristic curve analysis indicated that miR-155 but not miR-146a can be used as a marker of subfertility. MiR-155 with a cutoff value of 1.77 had 47% sensitivity and 95% specificity for identifying subfertility and a positive predictive value (PPV) and negative predictive value (NPV) of 95 and 47%, respectively. When used in combination with FSH, sensitivity and specificity were 80 and 100%, respectively, while PPV and NPV were 100 and 71%, respectively, those values being higher than for the FSH alone. Repeating the results obtained in the exploratory cohort in an independent confirmatory cohort reduced the risk of a chance finding. LIMITATIONS, REASONS FOR CAUTION: Although the results from the exploratory cohort were confirmed in the confirmatory cohort, studies from other centers are needed to establish the role of miR-155 as a new biomarker of male fertility. Furthermore, the role of this marker in distinguishing between different groups of male subfertility is to be elucidated. WIDER IMPLICATIONS OF THE FINDINGS: Association of the inflammatory miRNA miR-155 with male fertility contributes to our understanding of the pathophysiology of subfertility and suggests a novel biomarker. Serum miR-155 in combination with FSH has higher diagnostic specificity and sensitivity compared with FSH alone. STUDY FUNDING/COMPETING INTERESTS: This work was supported by grants from Swedish Governmental Grant (ALF), Skane county council research and development foundation, Skane University Hospital Fonds and by the EU and Greek funds under the action 'Education and lifelong learning' program THALIS-FAT-VESSEL (No 379527). The authors have no competing interests to disclose.

Association of recurrent venous thromboembolism and circulating microRNAs.

BACKGROUND: Patients with unprovoked first venous thromboembolism (VTE) are at a high risk of recurrence. Although circulating microRNAs (miRNAs) have been found to be associated with VTE and are markers of hypercoagulability, this study is the first to examine whether circulating miRNAs are associated with the risk of VTE recurrence. RESULTS: A nested case-control study design was used where plasma samples were obtained from 78 patients with unprovoked VTE from the Malmö Thrombophilia Study (MATS). A total of 39 VTE patients with recurrent VTE (cases) were matched with 39 VTE patients without recurrent VTE (controls) defined by age and sex (MATS population). Plasma levels of 179 different miRNAs were evaluated in the 78 samples (after anticoagulant treatment was stopped) using qPCR. A total of 110 miRNAs were detected in all samples. Among those, 12 miRNAs (miR-15b-5p, miR-106a-5p, miR-197-3p, miR-652-3p, miR-361-5p, miR-222-3p, miR-26b-5p, miR-532-5p, miR-27b-3p, miR-21-5p, miR-103a-3p, and miR-30c-5p) were found to be associated with recurrent VTE after multiple correction test and conditional logistic regression analysis. A further analysis showed that miR-15b-5p, miR-197-3p, miR-27b-3p, and miR-30c-5p exhibited a trend over time, with a larger difference in miRNA levels between cases and controls for earlier recurrence. Of these 12 miRNAs, 8 miRNAs significantly correlated with circulating transforming growth factor ß1/2 (TGFß1/2). Three of them correlated with platelet count. CONCLUSION: We have identified 12 plasma miRNAs that may have the potential to serve as novel, non-invasive predictive biomarkers for VTE recurrence.

Association of mitochondrial DNA in peripheral blood with depression, anxiety and stress- and adjustment disorders in primary health care patients.

Mitochondrial dysfunction may result in a variety of diseases. The objectives here were to examine possible differences in mtDNA copy number between healthy controls and patients with depression, anxiety or stress- and adjustment disorders; the association between mtDNA copy number and disease severity at baseline; and the association between mtDNA copy number and response after an 8-week treatment (mindfulness, cognitive based therapy). A total of 179 patients in primary health care (age 20-64 years) with depression, anxiety and stress- and adjustment disorders, and 320 healthy controls (aged 19-70 years) were included in the study. Relative mtDNA copy number was measured using quantitative real-time PCR on peripheral blood samples. We found that the mean mtDNA copy number was significantly higher in patients compared to controls (84.9 vs 75.9, p<0.0001) at baseline. The difference in mtDNA copy number between patients and controls remained significant after controlling for age and sex (ß=8.13, p<0.0001; linear regression analysis). The mtDNA copy number was significantly associated with Patient Health Questionnaire (PHQ-9) scores (ß=0.57, p=0.02) at baseline. After treatment, the change in mtDNA copy number was significantly associated with the treatment response, i.e., change in Hospital Anxiety and Depression Scale (HADS-D) and PHQ-9 scores (ß=1.00, p=0.03 and ß=0.65, p=0.04, respectively), after controlling for baseline scores, age, sex, BMI, smoking status, alcohol drinking and medication. Our findings show that mtDNA copy number is associated with symptoms of depression, anxiety and stress- and adjustment disorders and treatment response in these disorders.

Polymorphic variation in the androgen receptor gene: association with risk of testicular germ cell cancer and metastatic disease.

Increasing incidence of testicular germ cell cancer (TGCC) is most probably related to environment and lifestyle. However, an underlying genetic predisposition may play a role and since sex steroids are assumed to be important for the rise and progression of TGCC, a study of androgen receptor (AR) gene polymorphisms in relation to the risk, histological type and progression of TGCC was undertaken. In 367 TGCC cases and 214 controls, AR CAG and GGN repeat lengths were determined and 11 haplotype-tagging single nucleotide polymorphisms (SNPs) were genotyped. By binary logistic regression, odds ratios (ORs) and 95% confidence intervals (95% CI) were calculated for the risk of TGCC, non-seminoma versus seminoma and metastatic versus localised (stage I) disease. For the non-coding SNP, rs12014709, the minor genotype (G) was found in 10% of the cases and in 5.1% of the controls, conferring an OR of 2.07 (95% CI: 1.03-4.15) for having TGCC. Furthermore, short GGN (<23) was associated with an increased risk of metastatic disease (OR: 2.15; 95% CI: 1.04-4.45). The AR polymorphisms found by us might be involved in gene-environment interaction by increasing the susceptibility to the effect of endocrine disruptors. From a biological point of view, our findings strengthen the hypothesis of the importance of androgen action in the aetiology and pathogenesis of testicular malignancy. Future studies should focus on the impact of sex hormones on foetal germ cell development and the interaction between environmental factors and androgen receptor variants in relation to the risk of testicular malignancy.

Polymorphisms in the protein C inhibitor gene in in vitro fertilization failure.

The aim of this study was to determine whether total fertilization failure in human IVF can be partially explained by alterations in the gene that codes for protein C inhibitor. Forty-six men had IVF total fertilization failure and 51 controls with normal fertilization were screened for mutations in the protein C inhibitor gene by direct sequencing. The main finding was that in men involved in total fertilization failure, a heterozygous adenosine/guanine (A/G) base combination in position 1389 (rs2069990) (exon 6) in the protein C inhibitor gene was significantly more common compared with controls (10.9% vs. 0).

Emotional disorders in testicular cancer survivors in relation to hypogonadism, androgen receptor polymorphism and treatment modality.

PURPOSE: It has been documented that testicular germ cell cancer (TGCC) patients may be at increased risk of developing emotional distress (EMD). Hence, the aim of the present study was to investigate whether EMD is related to the presence of hypogonadism, androgen receptor (AR) polymorphism and/or treatment intensity. PATIENTS AND METHODS: Three to five years after treatment, testosterone and luteinizing hormone (LH) levels were measured in 165 TGCC patients. These patients also completed a questionnaire concerning mental health. EMD was measured by the Hospital Anxiety and Depression Scale (HADS). The androgen receptor (AR) gene has two polymorphic regions in exon I; glutamine encoding CAG and glycine encoding GGN repeats. Association between emotional disorders and AR polymorphisms as well as type of treatment was assessed. RESULTS: Neither anxiety (OR 1.0; 95% CI 0.40-2.4) nor depression (OR 1.1; 95% CI 0.20-6.4) were overrepresented in biochemically hypogonadal TGCC patients and no association between AR polymorphisms and EMD was found. Patients treated with >or=5 cycles of cisplatinum based chemotherapy due to refractory or relapsed disease were more prone to experiencing symptoms of anxiety (p=0.006), but not depression (p=0.38). CONCLUSIONS: Biochemical hypogonadism and AR polymorphism do not seem to be risk factors for EMD in TGCC patients. Patients with refractory or relapsed disease receiving >or=5 cycles of cisplatinum based chemotherapy may, to a higher degree than patients receiving less intense therapy, suffer from anxiety.