MiR-4485-3p expression reduced in spermatozoa of men with idiopathic asthenozoospermia

Low human sperm motility coexists with sperm nuclear DNA damage and oxidative stress in semen

BACKGROUND

Low sperm motility, one of the common causes of male infertility, is associated with abnormal sperm quality. Currently, important sperm/semen biomarkers are sperm chromatin status and oxidation‒reduction potential (ORP) in semen. Because the association between sperm motility and these biomarkers is still not fully clarified, our study was designed to verify the distribution and risk of sperm DNA fragmentation (SDF) and oxidative stress in semen in asthenozoospermic men.

MATERIALS AND METHODS

This study was carried out on discharged sperm cells of asthenozoospermic men (isolated asthenozoospermia or coexisted with reduced sperm number and/or morphology), nonasthenozoospermic men (reduced total sperm count and/or sperm morphology) (experimental groups) and normozoospermic men (proven and presumed fertility) (control group). Basic semen analysis was evaluated according to the 6th edition of the World Health Organization manual guidelines. SDF was assessed using the sperm chromatin dispersion test, while static(s) ORP in semen was measured by means of a MiOXSYS analyser.

RESULTS

The men from the asthenozoospermic group had lower basic semen parameters than those from the control and nonasthenozoospermic groups. In men with poor sperm motility SDF and sORP, prevalence and risk for > 20% SDF (high level of DNA damage) and for > 1.37 sORP (oxidative stress) were significantly higher than those of control and nonasthenozoospermic subjects. The risk for sperm DNA damage and oxidative stress in asthenozoospermic men was over 10-fold higher and almost 6-fold higher than those in control subjects and almost or over 3-fold higher than those in nonasthenozoospermic men.

CONCLUSIONS AND DISCUSSION

Poor human sperm motility coexisted with low basic sperm quality. Sperm DNA damage and oxidative stress in semen were much more frequent in asthenozoospermia. These abnormalities can decrease the sperm fertilizing capability under both natural and medically assisted reproduction conditions. Thus, in asthenozoospermia, the evaluation of sperm chromatin status and oxidation-reduction potential in semen is justified and inevitable, and the appropriate antioxidant therapy can be suggested.

MicroRNAs in Male Fertility

Around 50% of all occurrences of infertility are attributable to the male factor, which is a significant global public health concern. There are numerous circumstances that might interfere with spermatogenesis and cause the body to produce abnormal sperm. While evaluating sperm, the count, the speed at which they migrate, and their appearance are the three primary characteristics that are analyzed. MicroRNAs, also known as miRNAs, are present in all physiological fluids and tissues. They participate in both physiological and pathological processes. Researches have demonstrated that the expression of microRNA genes differs in infertile men. These genes regulate spermatogenesis at various stages and in several male reproductive cells. Hence, microRNAs have the potential to act as useful indicators in the diagnosis and treatment of male infertility and other diseases affecting male reproduction. Despite this, additional research is necessary to determine the precise miRNA regulation mechanisms.

MiR-4461 Inhibits Tumorigenesis of Renal Cell Carcinoma by Targeting PPP1R3C

Background: Renal cell carcinoma (RCC) is one of the most common and malignant tumors in the urinary system. The aim of this research was to investigate the mechanism and clinical significance of miR-4461 in the RCC progression. Materials and Methods: Twenty-eight (28) paired RCC tissue samples and adjacent nontumor tissue samples, as well as RCC cell lines were used to measure the expression of miR-4461 and protein phosphatase 1 regulatory subunit 3C (PPP1R3C) transcript by real-time quantitative PCR. The target relationship between miR-4461 and PPP1R3C was predicted by TargetScan and further verified by dual-luciferase reporter gene assay and RNA pull-down assay. Cell Counting Kit-8 (CCK-8) assay and BrdU ELISA assay were performed to measure RCC cell viability and proliferation. In addition, caspase-3 activity assay and cell adhesion assay were implemented to measure RCC cell apoptosis and adhesion. Results: MiR-4461 was lowly expressed both in RCC tissues and cells, while upregulated PPP1R3C was tested in RCC tissues and cells. In addition, miR-4461 was validated to directly target PPP1R3C, thereby negatively regulating PPP1R3C. Particularly, miR-4461 exerted a clear inhibitory effect on the malignant phenotypes of RCC cells by binding and inhibiting PPP1R3C. Conclusion: MiR-4461, which served as a tumor suppressor, inhibited RCC progression by targeting and downregulating PPP1R3C.

Moving beyond the Tip of the Iceberg: DJ-1 Implications in Cancer Metabolism

DJ-1, also called Parkinson’s protein 7 (PARK7), is ubiquitously expressed and plays multiple actions in different physiological and, especially, pathophysiological processes, as evidenced by its identification in neurodegenerative diseases and its high expression in different types of cancer. To date, the exact activity of DJ-1 in carcinogenesis has not been fully elucidated, however several recent studies disclosed its involvement in regulating fundamental pathways involved in cancer onset, development, and metastatization. At this purpose, we have dissected the role of DJ-1 in maintaining the transformed phenotype, survival, drug resistance, metastasis formation, and differentiation in cancer cells. Moreover, we have discussed the role of DJ-1 in controlling the redox status in cancer cells, along with the ability to attenuate reactive oxygen species (ROS)-dependent cell death, as well as to mediate ferropotosis. Finally, a mention to the development of therapeutic strategies targeting DJ-1 has been done. We have reported the most recent studies, aiming to shed light on the role played by DJ-1 in different cancer aspects and create the foundation for moving beyond the tip of the iceberg.

Using microRNAs as molecular biomarkers for the evaluation of male infertility

Infertility is a multiplex disorder in the reproductive system, and men are responsible for more than half of the cases. Nowadays, semen analysis has been considered the critical assessment test to diagnose infertile men; however, it has limitations so that the cause behind infertility in 40% of infertile men is unrevealed. Weaknesses of semen assessment indicate a global need for novel and better diagnostic tools and biomarkers. MicroRNAs are short (about 18-22 nucleotide length) non-coding RNAs that control most (>60%) of our protein-coding genes post-transcriptionally. These molecules are aberrant in the body fluids, and abnormal alterations in their expression level can signify a specific disease such as infertility. Therefore, microRNAs can be novel candidate biomarkers that can diagnose different types of male infertility, including azoospermia, oligozoospermia, asthenozoospermia and teratozoospermia. This narrative review aimed to collect and sum up new papers published about the significant role of microRNAs in different male infertility categories.

All you need to know about sperm RNAs

BACKGROUND

Spermatogenesis generates a small and highly specialised type of cell that is apparently incapable of transcription and translation. For many years, this dogma was supported by the assumption that (i) the compact sperm nucleus, resulting from the substitution of histones by protamine during spermatogenesis, renders the genome inaccessible to the transcriptional machinery; and (ii) the loss of most organelles, including endoplasmic reticulum and ribosomes, limits or prevents translational activity. Despite these observations, several types of coding and non-coding RNAs have been identified in human sperm. Their functional roles, particularly during fertilisation and embryonic development, are only now becoming apparent.

OBJECTIVE AND RATIONALE

This review aimed to summarise current knowledge of the origin, types and functional roles of sperm RNAs, and to evaluate the clinical benefits of employing these transcripts as biomarkers of male fertility and reproductive outcomes. The possible contribution of sperm RNAs to intergenerational or transgenerational phenotypic inheritance is also addressed.

SEARCH METHODS

A comprehensive literature search on PubMed was conducted using the search terms 'sperm' AND 'RNA'. Searches focussed upon articles written in English and published prior to August 2020.

OUTCOMES

The development of more sensitive and accurate RNA technologies, including RNA sequencing, has enabled the identification and characterisation of numerous transcripts in human sperm. Though a majority of these RNAs likely arise during spermatogenesis, other data support an epididymal origin of RNA transmitted to maturing sperm by extracellular vesicles. A minority may also be synthesised by de novo transcription in mature sperm, since a small portion of the sperm genome remains packed by histones. This complex RNA population has important roles in paternal chromatin packaging, sperm maturation and capacitation, fertilisation, early embryogenesis and developmental maintenance. In recent years, additional lines of evidence from animal models support a role for sperm RNAs in intergenerational or transgenerational inheritance, modulating both the genotype and phenotype of progeny. Importantly, several reports indicate that the sperm RNA content of fertile and infertile men differs considerably and is strongly modulated by the environment, lifestyle and pathological states.

WIDER IMPLICATIONS

Transcriptional profiling has considerable potential for the discovery of fertility biomarkers. Understanding the role of sperm transcripts and comparing the sperm RNA fingerprint of fertile and infertile men could help to elucidate the regulatory pathways contributing to male factor infertility. Such data might also provide a molecular explanation for several causes of idiopathic male fertility. Ultimately, transcriptional profiling may be employed to optimise ART procedures and overcome some of the underlying causes of male infertility, ensuring the birth of healthy children.

Parkinson Disease Protein 7 (PARK7) Is Related to the Ability of Mammalian Sperm to Undergo In Vitro Capacitation

Parkinson disease protein 7 (PARK7) is a multifunctional protein known to be involved in the regulation of sperm motility, mitochondrial function, and oxidative stress response in mammalian sperm. While ROS generation is needed to activate the downstream signaling pathways required for sperm to undergo capacitation, oxidative stress has detrimental effects for sperm cells and a precise balance between ROS levels and antioxidant activity is needed. Considering the putative antioxidant role of PARK7, the present work sought to determine whether this protein is related to the sperm ability to withstand in vitro capacitation. To this end, and using the pig as a model, semen samples were incubated in capacitation medium for 300 min; the acrosomal exocytosis was triggered by the addition of progesterone after 240 min of incubation. At each relevant time point (0, 120, 240, 250, and 300 min), sperm motility, acrosome and plasma membrane integrity, membrane lipid disorder, mitochondrial membrane potential, intracellular calcium and ROS were evaluated. In addition, localization and protein levels of PARK7 were also assessed through immunofluorescence and immunoblotting. Based on the relative content of PARK7, two groups of samples were set. As early as 120 min of incubation, sperm samples with larger PARK7 content showed higher percentages of viable and acrosome-intact sperm, lipid disorder and superoxide levels, and lower intracellular calcium levels when compared to sperm samples with lower PARK7. These data suggest that PARK7 could play a role in preventing sperm from undergoing premature capacitation, maintaining sperm viability and providing a better ability to keep ROS homeostasis, which is needed to elicit sperm capacitation. Further studies are required to elucidate the antioxidant properties of PARK7 during in vitro capacitation and acrosomal exocytosis of mammalian sperm, and the relationship between PARK7 and sperm motility.

Transcriptome-wide m6A profiling reveals mRNA post-transcriptional modification of boar sperm during cryopreservation

Background

Cryopreservation induces transcriptomic and epigenetic modifications that strongly impairs sperm quality and function, and thus decrease reproductive performance. N⁶-methyladenosine (m⁶A) RNA methylation varies in response to stress and has been implicated in multiple important biological processes, including post-transcriptional fate of mRNA, metabolism, and apoptosis. This study aimed to explore whether cryopreservation induces m⁶A modification of mRNAs associated with sperm energy metabolism, cryoinjuries, and freezability.

Results

The mRNA and protein expression of m⁶A modification enzymes were significantly dysregulated in sperm after cryopreservation. Furthermore, m⁶A peaks were mainly enriched in coding regions and near stop codons with classical RRACH motifs. The mRNAs containing highly methylated m⁶A peaks (fts vs. fs) were significantly associated with metabolism and gene expression, while the genes with less methylated m⁶A peaks were primarily involved in processes regulating RNA metabolism and transcription. Furthermore, the joint analysis of DMMGs and differentially expressed genes indicated that both of these play a vital role in sperm energy metabolism and apoptosis.

Conclusions

Our study is the first to reveal the dynamic m⁶A modification of mRNAs in boar sperm during cryopreservation. These epigenetic modifications may affect mRNA expression and are closely related to sperm motility, apoptosis, and metabolism, which will provide novel insights into understanding of the cryoinjuries or freezability of boar sperm during cryopreservation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-021-07904-8.

TRPM2-AS Promotes Bladder Cancer by Targeting miR-22-3p and Regulating GINS2 mRNA Expression

Background

Bladder cancer (BLCA) refers to the malignancy growth that spreads from the bladder linings to the bladder muscles. However, the impact of miR-22-3p and lncRNA TRPM2-AS on this tumor has generated divergent views in the literature. This research aimed to study the effects of lncRNA TRPM2-AS on BLCA and its interaction with miR-22-3p and GINS2 mRNA.

Methods

qRT-PCR was employed to measure the expression of TRPM2-AS, miR-22-3p and GINS2 mRNA in bladder tissues and cells. The subcellular localization of TRPM2-AS in T24 and 5637 cell lines was identified using a cell fractionation system. Luciferase assay, RIP assay and RNA pull-down assay were later performed to validate the direct binding relationship between TRPM2-AS, miR-22-3p and GINS2 mRNA. Several experiments were conducted to determine the viability, proliferation, colony formation and apoptosis of the cell lines.

Results

Findings indicated that TRPM2-AS was significantly upregulated in BLCA tissues and cell lines. Apart from that, it was observed that TRPM2-AS knockdown significantly inhibited the viability, proliferation and colony formation of BCLA cells, but it promoted the apoptosis of the BCLA cells. A significant downstream target of TRPM2-AS, miR-22-3p was found to show a lower expression level in BLCA tissues and cell lines. However, the inhibition of miR-22-3p considerably enhanced BLCA cell phenotypes. As well as discovering that GINS2 mRNA was a downstream target of miR-22-3p and was significantly upregulated in BLCA, experimental results also indicated that the knockdown of GINS2 suppressed BLCA cell phenotypes.

Conclusion

This research confirmed that TRPM2-AS could promote BCLA by binding to miR-22-3p to increase GINS2 expression. This novel interactome in BLCA cell lines might provide more insights into BLCA therapy.

Screening, identification and interaction analysis of key MicroRNAs and genes in Asthenozoospermia

Background: Asthenozoospermia, one of the most common causes of male infertility, is a complicate multifactorial pathological condition that genetic factors are involved in. However, the epigenetic signature and mechanism of asthenozoospermia still remain limited. Our study aimed to confirm the key microRNAs (miRNAs) and genes in asthenozoospermia and demonstrate the underlying epigenetic regulatory mechanisms. Methods: We screened out and pooled previous studies to extracted potential differentially expressed miRNAs (DEMs). GSE22331 and a published profile dataset were integrated to identify differentially expressed genes (DEGs). Pathway and gene ontology analysis were performed using DAVID. A protein-protein network (PPI) was constructed using STRING. The target genes of DEMs were predicted using TargetScan and the miRNA-mRNA network was built. Results: We reported 3 DEMs and 423 DEGs by pooling included dataset and published studies. Pathway analysis showed that these DEGs might participate in signaling pathways regulating pluripotency of stem cells, Wnt signaling pathway and Notch signaling pathway. 25 hub genes were identified, and the most significant gene was BDNF. We screened out the overlapped DEGs between the predicted target genes of 3 DEMs and the 423 DEGs. Finally, a potential miRNA-mRNA regulatory network was constructed. Conclusion: This study firstly pooled several published studies and a GEO dataset to determine the significance of potential miRNAs and genes, such as miR-374b, miR-193a, miR-34b, BDNF, NTRK2, HNRNPD and EFTUD2 in regulating asthenozoospermia and underscore their interactions in the pathophysiological mechanism. Our results provided theoretical basis and new clues for potential therapeutic treatment in asthenozoospermia. Validations in vivo and in vitro are required in future studies.

Yishentongluo decoction in treatment of idiopathic asthenozoospermia infertility: Study protocol for a randomized controlled trial

BACKGROUND

The reproductive dilemma faced by men has always been the focus of the whole society. Idiopathic asthenozoospermia (AZS), as one of the common causes of male infertility, lack of specific treatment. Traditional Chinese medicine has shown potential benefits in the management of male infertility. Yishentongluo decoction (YSTL) is a representative Chinese herbal formula; however, there is still no rigorous clinical trial supporting its application. Therefore, we designed a randomized controlled trial to evaluate the efficacy and safety of YSTL for patients with idiopathic AZS and explain the possible action mechanisms of YSTL in improving sperm motility.

METHODS

In this randomized controlled study, a total of 160 eligible patients will be assigned to YSTL group or the Levocarnitine oral solution group in a 1:1 ratio. The treatment period will be 12 weeks and the follow-up period will last 4 weeks. The primary outcome will be the the progressive (motility), sperm rate (%). Secondary outcomes will include the progressive (motility) + non-progressive (motility) sperm rate(%), total effective sperm count, inner mitochondrial membrane potential (MMP) in spermatozoa, and spouse pregnancy rate (%). Safety outcomes will cover electrocardiogram , blood tests (including blood routine test, hepatic function, and renal function), urine routine test, and stool routine test. The semen parameters, sperm MMP test, and all the safety outcomes will be performed at the baseline, 4th, 8th and 12th week. The pregnancy outcome will be evaluated at 4 weeks after treatment.

DISCUSSION

This study will provide initial evidence regarding the efficacy and safety of YSTL in the treatment of idiopathic AZS with kidney deficiency and blood stasis pattern. In addition, potential mechanisms of YSTL in improving sperm motility will be explored based on sperm MMP test.

TRIAL REGISTRATION

Chinese Clinical Trials Register identifier, ChiCTR2000033290, registered on 26 May 2020.