Normospermic Patients Infected With Ureaplasma parvum: Role of Dysregulated miR-122-5p, miR-34c-5, and miR-141-3p

Background

Ureaplasma parvum (UP) is a causative agent of non-gonococcal urethritis, involved in the pathogenesis of prostatitis and epididymitis, and it could impair human fertility. Although UP infection is a frequent cause of male infertility the study evidence assessing their prevalence and the association in patients with infertility is still scarce. The molecular processes leading to defects in spermatozoa quality are not completely investigated. MicroRNAs (miRNAs) have been extensively reported as gene regulatory molecules on post-transcriptional levels involved in various biological processes such as gametogenesis, embryogenesis, and the quality of sperm, oocyte, and embryos.

Methods

Therefore, the study design was to demonstrate that miRNAs in body fluids like sperm could be utilized as non-invasive diagnostic biomarkers for pathological and physiological conditions such as infertility. A post-hoc bioinformatics analysis was carried out to predict the pathways modulated by the miRNAs dysregulated in the differently motile spermatozoa.

Results

Here it is shown that normospermic patients infected by UP had spermatozoa with increased quantity of superoxide anions, reduced expression of miR-122-5p, miR-34c-5, and increased miR-141-3p compared with non-infected normospermic patients. This corresponded to a reduction of sperm motility in normospermic infected patients compared with normospermic non-infected ones. A target gene prediction presumed that an essential role of these miRNAs resided in the regulation of lipid kinase activity, accounting for the changes in the constitution of spermatozoa membrane lipids caused by UP.

Conclusions

Altogether, the data underline the influence of UP on epigenetic mechanisms regulating spermatozoa motility.

Extracellular vesicle-coupled miRNA profiles of chicken seminal plasma and their potential interaction with recipient cells

The presence of EVs in seminal plasma (SPEVs) suggests their involvement on fertility via transmitting information between the original cells and recipient cells. SPEVs-coupled miRNAs have been shown to affect sperm motility, maturation, and capacitation in mammals, but rarely in poultry species. The present study aims to reveal the profile of SPEVs miRNAs and their potential effect on sperm storage and function in poultry. The SPEVs was successfully isolated from 4 different chicken breeds by ultracentrifugation and verified. Deep sequencing of SPEVs small RNA library of each breed identified 1077 miRNAs in total and 563 shared ones. The top 10 abundant miRNAs (such as miR-10-5p, miR-100-5p, and miR-10a-5p etc.) accounted for around 60% of total SPEVs miRNA reads and are highly conserved across species, predisposing their functional significance. Target genes prediction and functional enrichment analysis indicated that the most abundantly expressed miRNAs may regulate pathways like ubiquitin-mediated proteolysis, endocytosis, mitophagy, glycosphingolipid biosynthesis, fatty acid metabolism, and fatty acid elongation. The high abundant SPEVs-coupled miRNAs were found to target 107 and 64 functionally important mRNAs in the potential recipient cells, sperm and sperm storage tubules (SST) cells, respectively. The pathways that enriched by target mRNAs revealed that the SPEVs-coupled miRNA may rule the fertility by affecting the sperm maturation and regulating the female's immune response and lipid metabolism. In summary, this study presents the distinctive repertoire of SPEVs-coupled miRNAs, and extends our understanding about their potential roles in sperm maturation, capacitation, storage, and fertility, and may help to develop new therapeutic strategies for male infertility and sperm storage.

Potential Function of Testicular MicroRNAs in Heat-Stress-Induced Spermatogenesis Disorders

Spermatogenesis is temperature-dependent, and the increase in testicular temperature seriously affects mammalian spermatogenesis and semen quality. In this study, the testicular heat stress model of mice was made with a 43 °C water bath for 25 min, and the effects of heat stress on semen quality and spermatogenesis-related regulators were analyzed. On the 7th day after heat stress, testis weight shrank to 68.45% and sperm density dropped to 33.20%. High-throughput sequencing analysis showed that 98 microRNAs (miRNAs) and 369 mRNAs were down-regulated, while 77 miRNAs and 1424 mRNAs were up-regulated after heat stress. Through gene ontology (GO) analysis of differentially expressed genes and miRNA-mRNA co-expression networks, it was found that heat stress may be involved in the regulation of testicular atrophy and spermatogenesis disorders by affecting cell meiosis process and cell cycle. In addition, through functional enrichment analysis, co-expression regulatory network, correlation analysis and in vitro experiment, it was found that miR-143-3p may be a representative potential key regulatory factor affecting spermatogenesis under heat stress. In summary, our results enrich the understanding of miRNAs in testicular heat stress and provide a reference for the prevention and treatment of heat-stress-induced spermatogenesis disorders.

Further Insights on RNA Expression and Sperm Motility

Asthenozoospermia is one of the main causes of male infertility and it is characterized by reduced sperm motility. Several mutations in genes that code for structural or functional constituents of the sperm have already been identified as known causes of asthenozoospermia. In contrast, the role of sperm RNA in regulating sperm motility is still not fully understood. Consequently, here we aim to contribute to the knowledge regarding the expression of sperm RNA, and ultimately, to provide further insights into its relationship with sperm motility. We investigated the expression of a group of mRNAs by using real-time PCR (CATSPER3, CFAP44, CRHR1, HIP1, IQCG KRT34, LRRC6, QRICH2, RSPH6A, SPATA33 and TEKT2) and the highest score corresponding to the target miRNA for each mRNA in asthenozoospermic and normozoospermic individuals. We observed a reduced expression of all mRNAs and miRNAs in asthenozoospermic patients compared to controls, with a more accentuated reduction in patients with progressive sperm motility lower than 15%. Our work provides further insights regarding the role of RNA in regulating sperm motility. Further studies are required to determine how these genes and their corresponding miRNA act regarding sperm motility, particularly KRT34 and CRHR1, which have not previously been seen to play a significant role in regulating sperm motility.

Placental expression of RNU44, RNU48 and miR-16-5p: stability and relations with fetoplacental growth

BACKGROUND/OBJECTIVES

The current study aimed to identify suitable reference miRNA for placental miRNA expression analysis in a set of well-characterized and fetal-sex balanced small- (SGA) and appropriate- (AGA) for gestational age full-term singleton pregnancies.

SUBJECTS/METHODS

In this retrospective study, placental samples (n = 106) from 35 SGA (19 male and 16 female) and 71 AGA (30 male and 41 female) full-term singleton pregnancies were utilized. Placental transcript abundance of three widely used reference miRNAs [miR-16-5p and Small nucleolar RNAs (snoRNAs) RNU44 and RNU48] were assessed by real-time quantitative PCR. Raw cycle threshold (C_t) analysis and RefFinder tool analysis were conducted for evaluating stability of expression of these miRNAs.

RESULTS

Raw C_t values of miR-16-5p were similar between SGA and AGA births (P = 0.140) and between male and female births within SGA (P = 0.159) and AGA (P = 0.060) births while that of RNU44 and RNU48 were higher in SGA births (P = 0.008 and 0.006 respectively) and in male births within the SGA group (P = 0.005) for RNU44 and in female births within the AGA group (P = 0.048) for RNU48. Across all 106 samples tested using the RefFinder tool, miR-16-5p and RNU44 were equally stable reference miRNAs.

CONCLUSION

We recommend miR-16-5p and RNU44 as suitable reference miRNAs for placental samples from settings similar to our study.

Long Non-coding RNAs and MicroRNAs Interplay in Osteogenic Differentiation of Mesenchymal Stem Cells

Long non-coding RNAs (lncRNAs) have gained great attention as epigenetic regulators of gene expression in many tissues. Increasing evidence indicates that lncRNAs, together with microRNAs (miRNAs), play a pivotal role in osteogenesis. While miRNA action mechanism relies mainly on miRNA-mRNA interaction, resulting in suppressed expression, lncRNAs affect mRNA functionality through different activities, including interaction with miRNAs. Recent advances in RNA sequencing technology have improved knowledge into the molecular pathways regulated by the interaction of lncRNAs and miRNAs. This review reports on the recent knowledge of lncRNAs and miRNAs roles as key regulators of osteogenic differentiation. Specifically, we described herein the recent discoveries on lncRNA-miRNA crosstalk during the osteogenic differentiation of mesenchymal stem cells (MSCs) derived from bone marrow (BM), as well as from different other anatomical regions. The deep understanding of the connection between miRNAs and lncRNAs during the osteogenic differentiation will strongly improve knowledge into the molecular mechanisms of bone growth and development, ultimately leading to discover innovative diagnostic and therapeutic tools for osteogenic disorders and bone diseases.

MicroRNA-targeting in spermatogenesis: Over-expressions of microRNA-23a/b-3p and its affected targeting of the genes ODF2 and UBQLN3 in spermatozoa of patients with oligoasthenozoospermia

BACKGROUND

Male infertility is a multifactorial syndrome with diverse phenotypic representations. MicroRNAs (miRNAs) are small, non-coding RNAs that are involved in the post-transcriptional regulation of gene expression. Altered abundance levels of ODF2 and UBQLN3 have been reported in patients with different spermatogenic impairments. However, the transcriptional regulation of these two genes by miR-23a/b-3p is still unclear.

OBJECTIVES

To investigate experimentally whether miR-23a/b-3p targets the genes ODF2 and UBQLN3 and whether this targeting impacts abundance levels of ODF2 and UBQLN3 in patients with oligoasthenozoospermia.

MATERIALS AND METHODS

A total of 92 men attending a fertility clinic were included in the study, including 46 oligoasthenozoospermic men and 46 age-matched normozoospermic volunteers who served as controls. Reverse transcription-quantitative PCR (RT-qPCR), Western blot, and dual-luciferase (Firefly-Renilla) assays were used to validate the miRNAs and their target genes.

RESULTS

RT-qPCR revealed that miR-23a/b-3p was more abundant and ODF2 and UBQLN3 targets were less abundant in men with impaired spermatogenesis. Besides, Western blot shows that ODF2 and UBQLN3 protein levels were reduced in men with impaired spermatogenesis. In silico prediction and dual-luciferase assays revealed that potential links exist between the higher abundance level of miR-23a/b-3p and the lower abundance level of ODF2 and UBQLN3 targets. Mutations in the miR-23a/b-3p-binding site within the 3'UTRs (3'untranslated regions) of ODF2 and UBQLN3 genes resulted in abrogated responsiveness to miR-23a/b-3p. Correlation analysis showed that sperm count, motility, and morphology were negatively correlated with miR-23a/b-3p and positively correlated with the lower abundance level of UBQLN3, while ODF lower abundance level was positively correlated with sperm motility.

CONCLUSION

Findings indicate that the higher abundance level of miR-23a/b-3p and the lower abundance level of ODF2 and UBQLN3 targets are associated with oligoasthenozoospermia and male subfertility.

Non-Coding RNAs as Biomarkers and Therapeutic Targets for Diabetic Kidney Disease

Diabetic kidney disease (DKD) is the most common diabetic complication and is a leading cause of end-stage kidney disease. Increasing evidence shows that DKD is regulated not only by many classical signaling pathways but also by epigenetic mechanisms involving chromatin histone modifications, DNA methylation, and non-coding RNA (ncRNAs). In this review, we focus on our current understanding of the role and mechanisms of ncRNAs, including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) in the pathogenesis of DKD. Of them, the regulatory role of TGF-β/Smad3-dependent miRNAs and lncRNAs in DKD is highlighted. Importantly, miRNAs and lncRNAs as biomarkers and therapeutic targets for DKD are also described, and the perspective of ncRNAs as a novel therapeutic approach for combating diabetic nephropathy is also discussed.

NormiRazor: tool applying GPU-accelerated computing for determination of internal references in microRNA transcription studies

BACKGROUND

Multi-gene expression assays are an attractive tool in revealing complex regulatory mechanisms in living organisms. Normalization is an indispensable step of data analysis in all those studies, since it removes unwanted, non-biological variability from data. In targeted qPCR assays it is typically performed with respect to prespecified reference genes, but the lack of robust strategy of their selection is reported in literature, especially in studies concerning circulating microRNAs (miRNA). Unfortunately, this problem impedes translation of scientific discoveries on miRNA biomarkers into widely available laboratory assays. Previous studies concluded that averaged expressions of multi-miRNA combinations are more stable references than single genes. However, due to the number of such combinations the computational load is considerable and may be hindering for objective reference selection in large datasets. Existing implementations of normalization algorithms (geNorm, NormFinder and BestKeeper) have poor performance and may require days to compute stability values for all potential reference as the evaluation is performed sequentially.

RESULTS

We designed NormiRazor - an integrative tool which implements those methods in a parallel manner on a graphics processing unit (GPU) using CUDA platform. We tested our approach on publicly available miRNA expression datasets. As a result, the times of executions on 8 datasets containing from 50 to 400 miRNAs (subsets of GSE68314) decreased 18.7 ±0.6 (mean ±SD), 104.7 ±4.2 and 76.5 ±2.2 times for geNorm, BestKeeper and NormFinder with respect to previous Python implementation. To allow for easy access to normalization pipeline for biomedical researchers we implemented NormiRazor as an online platform where a user could normalize their datasets based on the automatically selected references. It is available at norm.btm.umed.pl, together with instruction manual and exemplary datasets.

CONCLUSIONS

NormiRazor allows for an easy, informed choice of reference genes for qPCR transcriptomic studies. As such it can improve comparability and repeatability of experiments and in longer perspective help translate newly discovered biomarkers into readily available assays.

Male reproductive dysfunction in Solea senegalensis: new insights into an unsolved question

Senegalese sole (Solea senegalensis) is a species with a high commercial value that exhibits a reproductive dysfunction in males born and raised in captivity (F1) that hinders their sustainable culture. The present study evaluates the sperm quality and dopaminergic pathway of males born in the wild environment and of F1 males. Traditional sperm analyses were performed, finding only significant differences in curvilinear velocity (VCL) and no significant differences in viability and total motility. No differences in global sperm methylation were observed either in spermatozoa or brain between the two groups (F1 and wild-born males). However, our results point to a different sperm molecular signature between wild fish and fish born in captivity, specifically the differential expression in miR-let7-d and miR-200a-5p between these two groups. miR-let7-d has been correlated with spermatogenesis and sex preferences, whereas the miR-200 family is implied in target innervation of dopaminergic neurons in zebrafish. When we analysed the dopaminergic pathway, no differences were found in terms of different mRNA expression of dopaminergic markers. However, some differences were detected in terms of tyrosine hydroxylase protein expression by western blot analysis, thus suggesting an altered post-transcriptional regulation in F1 males. The results of this study suggest that an altered sperm miRNA signature in F1 males could be one possible mode of transmission of reproductive dysfunction to the progeny.

Expression of miRNA-371a-3p in seminal plasma and ejaculate is associated with sperm concentration

BACKGROUND

The microRNAs of the miR-371-3 cluster are novel serum markers for testicular germ cell tumors. Sporadic reports suggested the expression of this miRNA in semen.

OBJECTIVES

To verify the expression of miR-371a-3p in seminal plasma and unprocessed ejaculate; to compare seminal plasma miRNA levels in germ cell tumors patients with those of controls; to look for an association of miRNA levels with semen quality.

MATERIALS AND METHODS

The miR-371a-3p expression was analyzed with qPCR. The study population consisted of 100 participants: seminal plasma samples from 20 germ cell tumors patients and 30 controls, serum samples from 12 healthy men, ejaculate samples from 38 men undergoing fertility testing.

RESULTS

The seminal plasma miR-371a-3p levels of germ cell tumors patients were not different from controls. The miRNA expression was very low in serum but much higher in seminal plasma. In ejaculate samples, the miRNA expression significantly correlated with sperm concentration and the total sperm count.

DISCUSSION

miR-371-a-3p is present in sperm-containing fluids. Seminal plasma levels cannot be used to distinguish germ cell tumors from controls. The correlation with sperm concentration in ejaculate samples suggests the spermatozoa as possible source of miR-371a-3p production.

CONCLUSION

The miR-371a-3p levels in ejaculate could represent a novel biomarker for the non-invasive evaluation of male infertility.

LncRNA-Gm2044 is transcriptionally activated by A-MYB and regulates Sycp1 expression as a miR-335-3p sponge in mouse spermatocyte-derived GC-2spd(ts) cells

Long noncoding RNAs (lncRNAs) have been shown to execute key roles in spermatogenesis. However, little is known about how lncRNAs gene expression is itself regulated in the germ cells of testis. We previously demonstrated that high expression of lncRNA-Gm2044 exists in spermatocytes and can regulate male germ cell proliferation. Here, the transcriptional regulation of lnRNA-Gm2044 expression in spermatocytes and the downstream signaling were further explored. A bioinformatics assessment predicted two potential binding-sites for the spermatocyte-specific transcription factor A-MYB in the promoter region of lncRNA-Gm2044. Our results proved that the transcription factor A-MYB promotes the expression of lncRNA-Gm2044 in mouse spermatocyte-derived GC-2spd(ts) cells. ChIP and luciferase assays verified that A-MYB mainly binds to the distal promoter region (-819 bp relative to the transcription start site) of lncRNA-Gm2044 and regulates lncRNA-Gm2044 expression through the -819 bp binding-site. In addition, we confirmed that lncRNA-Gm2044 functions as a miR-335-3p sponge to enhance the levels of miR-335-3p's direct target protein, Sycp1. Furthermore, A-MYB can up-regulate Sycp1 expression and down-regulate GC-2spd(ts) cell proliferation by activating its target, lncRNA-Gm2044. Overexpression of lncRNA-Gm2044 or knockdown of miR-335-3p can, at least partially, rescue the effects of A-MYB on Sycp1 expression and GC-2spd(ts) cell proliferation.Taken together, our results provide new information on the mechanistic roles of lncRNA-miRNA in transcription factor A-MYB regulation of spermatocyte function.

Sperm microRNA pairs: new perspectives in the search for male fertility biomarkers

OBJECTIVE

To identify candidates of fertility biomarkers among pairs of human sperm microRNAs.

DESIGN

Expression data of 736 sperm microRNAs from fertile and infertile individuals characterized in previous published studies by means of TaqMan quantitative polymerase chain reaction (PCR) were reexamined. A set of microRNA pairs with the best biomarker potential were selected and validated by means of quantitative real-time (qRT) PCR in an independent cohort.

SETTING

University laboratory.

PATIENT(S)

Semen samples were obtained from fertile (n = 10) and infertile (asthenozoospermia, n = 10; teratozoospermia, n = 10; oligozoospermia, n = 10; unexplained male infertility [UMI], n = 8) individuals. The validation cohort included 9 fertile donors and 14 infertile patients with different seminal alterations.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Spearman test was used to select microRNA pairs with a correlated expression in fertile individuals and a noncorrelated expression in each infertile group. The biomarker potential of these pairs was determined with the use of receiver operating characteristic curves. The differential relative expression of each pair in fertile and infertile populations was verified (Mann-Whitney test). Those pairs with best results were validated by qRT-PCR.

RESULT(S)

Forty-eight pairs showed significant correlations in the fertile group. The pairs that were uncorrelated in the infertile populations and displayed the best biomarker potential were hsa-miR-942-5p/hsa-miR-1208 (asthenozoospermia), hsa-miR-296-5p/hsa-miR-328-3p (teratozoospermia), hsa-miR-139-5p/hsa-miR-1260a (oligozoospermia), and hsa-miR-34b-3p/hsa-miR-93-3p (UMI). The hsa-miR-942-5p/hsa-miR-1208 pair showed the greatest potential for detecting seminal alterations in the validation cohort (85.71% true positives).

CONCLUSION(S)

The pairs hsa-miR-942-5p/hsa-miR-1208 and hsa-miR-34b-3p/hsa-miR-93-3p have the potential to become new molecular biomarkers that could help to diagnose male infertility, especially in cases of UMI or when seminal parameters are close to the threshold values.

Effect of low sperm quality on progeny: a study on zebrafish as model species

Nowadays a decrease tendency in human sperm quality has been reported mainly in developed countries. Reproductive technologies have been very valuable in achieving successful pregnancies with low quality sperm samples. However, considering that spermatozoa molecular contribution is increasingly important in recent studies, it is crucial to study whether fertilization with low sperm quality could leave a molecular mark on progeny. This study explores the consequences that fertilization with low sperm quality may have on progeny, using zebrafish as a model. Good and bad breeders were established attending to sperm quality analyses and were individually tracked. Significant differences in fertilization and malformation rates were obtained in progenies between high and low quality sperm samples. Moreover an altered miR profile was found in the progenies of bad zebrafish breeders (upregulation of miR-141 and miR -122 in 24 hpf embryos) and as a consequence, some of their targets involved in male sex development such as dmrt1, suffered downregulation. Our results indicate that fertilizing with high sperm quality samples becomes relevant from a new perspective: to avoid molecular alterations in the progeny that could remain masked and therefore produce unexpected consequences in it.

Effect of nut consumption on semen quality and functionality in healthy men consuming a Western-style diet: a randomized controlled trial

BACKGROUND

Human semen quality has declined in industrialized countries. Pollution, smoking, and the consumption of a Western-style diet are all hypothesized as potential causes.

OBJECTIVE

We evaluated the effect of chronic consumption of nuts on changes in conventional semen parameters and the potential mechanisms implicated.

DESIGN

The FERTINUTS study was a 14-wk randomized, controlled, parallel trial. A total of 119 healthy men, aged 18-35 y, were allocated to 1 of 2 intervention groups: one group was fed the usual Western-style diet enriched with 60 g of a mixture of nuts/d (nut group), and the other was fed the usual Western-style diet avoiding nuts (control group). Semen and blood samples were collected at baseline and at the end of the intervention. Dietary information was recorded throughout the trial. Changes in conventional semen parameters (pH, volume, sperm count and concentration, motility, and morphology) were determined as primary outcomes. The effect of nut consumption on sperm DNA fragmentation (SDF), reactive oxygen species (ROS) production, chromosome anomalies (X, Y, and 18), total DNA methylation, and microRNA expression were measured in sperm samples as potential causes of the changes in the seminogram.

RESULTS

Compared with the control group, improvements in total sperm count (P = 0.002) and vitality (P = 0.003), total motility (P = 0.006), progressive motility (P = 0.036), and morphology of sperm (P = 0.008) were observed in the nut group. Participants in the nut group showed an increase in the consumption of total fat, monounsaturated fatty acids, polyunsaturated fatty acids, magnesium, vitamin E, α-linolenic acid, total omega-3 (n-3) and ω-3:ω-6 ratio intake during the intervention. Participants in the nut group showed a significant reduction in SDF (P < 0.001) and in the expression of hsa-miR-34b-3p (P = 0.036). No significant changes in ROS, sperm chromosome anomalies, or DNA methylation were observed between groups.

CONCLUSIONS

The inclusion of nuts in a Western-style diet significantly improves the total sperm count and the vitality, motility, and morphology of the sperm. These findings could be partly explained by a reduction in the sperm DNA fragmentation. This trial was registered at ISRCTN as ISRCTN12857940.