The miR-125 family is an important regulator of the expression and maintenance of maternal effect genes during preimplantational embryo development

Space radiation damage rescued by inhibition of key spaceflight associated miRNAs

Our previous research revealed a key microRNA signature that is associated with spaceflight that can be used as a biomarker and to develop countermeasure treatments to mitigate the damage caused by space radiation. Here, we expand on this work to determine the biological factors rescued by the countermeasure treatment. We performed RNA-sequencing and transcriptomic analysis on 3D microvessel cell cultures exposed to simulated deep space radiation (0.5 Gy of Galactic Cosmic Radiation) with and without the antagonists to three microRNAs: miR-16-5p, miR-125b-5p, and let-7a-5p (i.e., antagomirs). Significant reduction of inflammation and DNA double strand breaks (DSBs) activity and rescue of mitochondria functions are observed after antagomir treatment. Using data from astronaut participants in the NASA Twin Study, Inspiration4, and JAXA missions, we reveal the genes and pathways implicated in the action of these antagomirs are altered in humans. Our findings indicate a countermeasure strategy that can potentially be utilized by astronauts in spaceflight missions to mitigate space radiation damage.

MiR-124-3p negatively impacts embryo implantation via suppressing uterine receptivity formation and embryo development

During embryo implantation, blastocyst interacts with the receptivity endometrium and the endometrial epithelium secretes nurturing fluid to support embryonic development. Interferon-λ (IFN-λ) is a novel, non-redundant regulator that participates in the fetal-maternal interaction; however, the precise molecular mechanism underlying its impact on uterine receptivity remains elusive. Here, microarray profiling revealed that 149 specific miRNAs were differentially expressed in the human endometrial cells following IFN-λ treatment. In particular, miR-124-3p expression was significantly reduced after IFN-λ treatment (p < 0.05). An in vivo mouse pregnancy model showed that miR-124-3p overexpression notably decreased embryo implantation rate and led to an aberrant epithelial phenotype. Furthermore, miR-124-3p negatively impacted the migration and proliferation of endometrial cells, and hindered embryonic developmental competence in terms of blastocyst formation and global DNA re-methylation. Downstream analysis showed that LIF, MUC1 and BCL2 are potential target genes for miR-124-3p, which was confirmed using western blotting and immunofluorescence assays. In conclusion, IFN-λ-driven downregulation of miR-124-3p during embryo implantation modulates uterine receptivity. The dual functional role of miR-124-3p suggests a cross-talk model wherein, maternal endometrial miRNA acts as a transcriptomic modifier of the peri-implantation endometrium and embryo development.

Predictive modeling of oocyte maternal mRNA features for five mammalian species reveals potential shared and species-restricted regulators during maturation

Oocyte maturation is accompanied by changes in abundances of thousands of mRNAs, many degraded and many preferentially stabilized. mRNA stability can be regulated by diverse features including GC content, codon bias, and motifs within the 3'-untranslated region (UTR) interacting with RNA binding proteins (RBPs) and miRNAs. Many studies have identified factors participating in mRNA splicing, bulk mRNA storage, and translational recruitment in mammalian oocytes, but the roles of potentially hundreds of expressed factors, how they regulate cohorts of thousands of mRNAs, and to what extent their functions are conserved across species has not been determined. We performed an extensive in silico cross-species analysis of features associated with mRNAs of different stability classes during oocyte maturation (stable, moderately degraded, and highly degraded) for five mammalian species. Using publicly available RNA sequencing data for germinal vesicle (GV) and MII oocyte transcriptomes, we determined that 3'-UTR length and synonymous codon usage are positively associated with stability, while greater GC content is negatively associated with stability. By applying machine learning and feature selection strategies, we identified RBPs and miRNAs that are predictive of mRNA stability, including some across multiple species and others more species-restricted. The results provide new insight into the mechanisms regulating maternal mRNA stabilization or degradation.NEW & NOTEWORTHY Conservation across species of mRNA features regulating maternal mRNA stability during mammalian oocyte maturation was analyzed. 3'-Untranslated region length and synonymous codon usage are positively associated with stability, while GC content is negatively associated. Just three RNA binding protein motifs were predicted to regulate mRNA stability across all five species examined, but associated pathways and functions are shared, indicating oocytes of different species arrive at comparable physiological destinations via different routes.

Combined analysis of mRNA-miRNA from testis tissue in Tibetan sheep with different FecB genotypes

Testis size is important for identifying breeding animals with adequate sperm production. The aim of this study was to survey the expression profile of mRNA and miRNA in testis tissue from rams carrying different FecB genotypes, including the wild-type and heterozygous genotypes in Tibetan sheep. Comparative transcriptome profiles for ovine testes were established for wild-type and heterozygote Tibetan sheep by next-generation sequencing. RNA-seq results identified 3,910 (2,034 up- and 1,876 downregulated) differentially expressed (DE) genes and 243 (158 up- and 85 downregulated) DE microRNAs (miRNAs) in wild-type vs heterozygote sheep, respectively. Combined analysis of mRNA-seq and miRNA-seq revealed that 20 miRNAs interacted with 48 true DE target genes in wild-type testes compared to heterozygous genotype testes. These results provide evidence for a functional series of genes operating in Tibetan sheep testis. In addition, quantitative real-time PCR analysis showed that the expression trends of randomly selected DE genes in testis tissues from different genotypes were consistent with high-throughput sequencing results.

Glucocorticoid exposure modifies the miRNA profile of sperm in the guinea pig: Implications for intergenerational transmission

Approximately 1%-3% of the adult population are treated with synthetic glucocorticoids (sGCs) for a variety of conditions. Studies have demonstrated that adversities experienced by males prior to conception may lead to abnormal neuroendocrine function and behaviors in offspring and that epigenetic factors including microRNA (miRNA) within sperm may be responsible for driving these effects. However, it remains unclear where in the epididymis sperm miRNA changes are occurring. Here, we hypothesized that sGC exposure will alter the miRNA profile of sperm in the epididymis in a region-specific manner. Adult male guinea pigs were exposed to regular drinking water (Ctrl) or water with the sGC dexamethasone (Dex; 3mg/kg) (n = 6/group) every other day for 48 days. Sperms were collected from epididymal seminal fluid in the caput and cauda regions of the epididymis and total RNA was extracted. miRNAs were assessed by miRNA 4.0 microarray; data were processed by TAC 4.0.1 and R. miRNA analysis revealed one miRNA in the caput that was significantly decreased by Dex in sperm. In the cauda, 31 miRNAs were reduced in sperm following Dex-exposure. The findings of this study demonstrate that Dex-exposure influences miRNA profile of sperm in the cauda but not the caput of the epididymis. This suggests that glucocorticoids target the epididymis to modify sperm miRNA and do not modify the miRNA content during spermiation in the testes.

Isolation, characterization, proteome, miRNAome, and the embryotrophic effects of chicken egg yolk nanovesicles (vitellovesicles)

Egg yolk constitutes about a third of the structure of the chicken egg however, the molecular structure and physiological effects of egg yolk-derived lipid membranous vesicles are not clearly understood. In this study, for the first record, the egg yolk nanovesicles (vitellovesicles, VVs) were isolated, characterized, and used as a supplement for porcine embryo culture. Yolks of ten freshly oviposited eggs were filtered and ultracentrifuged at 100,000 × g for 3 h to obtain a pellet. Cryogenic transmission electron microscopy and nanoparticle tracking analysis of the pellet revealed bilipid membranous vesicles. Protein contents of the pellet were analyzed using tandem mass spectrometry and the miRNA content was also profiled through BGISEQ-500 sequencer. VVs were supplemented with the in vitro culture medium of day-7 hatched parthenogenetic blastocysts. After 2 days of blastocyst culture, the embryonic cell count was increased in VVs supplemented embryos in comparison to the non-supplemented embryos. TUNEL assay showed that apoptotic cells were increased in control groups when compared with the VVs supplemented group. Reduced glutathione was increased by 2.5 folds in the VVs supplemented group while reactive oxygen species were increased by 5.3 folds in control groups. Quantitative PCR analysis showed that VVs significantly increased the expression of lipid metabolism-associated genes (monoglyceride lipase and lipase E), anti-apoptotic gene (BCL2), and superoxide dismutase, while significantly reducing apoptotic gene (BAX). Culturing embryos on Matrigel basement membrane matrix indicated that VVs significantly enhanced embryo attachment and embryonic stem cell outgrowths compared to the non-supplemented group. This considers the first report to characterize the molecular bioactive cargo contents of egg yolk nanovesicles to show their embryotrophic effect on mammalian embryos. This effect might be attributed to the protein and miRNA cargo contents of VVs. VVs can be used for the formulation of in vitro culture medium for mammalian embryos including humans.

Expression of microRNA let-7 in cleavage embryos modulates cell fate determination and formation of mouse blastocysts†

After fertilization, the zygote undergoes cell division. Up to the 8-cell stage, the blastomeres of mouse preimplantation embryos are morphologically identical. The first cell differentiation starts in the morula leading to the formation of trophectoderm cells and inner cell mass cells of the blastocyst. The regulation of the differentiation event and the formation of blastocysts are not fully known. Lethal-7 (let-7) is a family of evolutionarily conserved microRNAs. Here, we showed that the expression of let-7a and let-7g decreased drastically from the 1-cell stage to the 2-cell stage, remained low up to the 8-cell stage and slightly increased after the morula stage of mouse embryos. The expression of let-7 in the inner cell mass was higher than that in the trophectoderm. Forced expression of let-7a in embryos at the 1-cell and 4-cell stage inhibited blastocyst formation and downregulated the expression of CDX2 but maintained that of OCT4 in the trophectoderm. Forced expression of other let-7 isoforms exhibited similar inhibitory action on blastulation. On the other hand, inhibition of let-7a at the 4-cell stage and the 8-cell stage enhanced blastocyst formation. Co-injection of green fluorescent protein (GFP) mRNA (lineage tracer) with either precursor of let-7a (pre-let-7a) or scramble control into one blastomere of 2-cell embryos showed that ~75% of the resulting blastocysts possessed GFP+ cells in their inner cell mass only. The biased development towards the inner cell mass with forced expression of let-7 was reproduced in 2-cell chimeric embryos consisting of one wildtype blastomere and one GFP mRNA-injected blastomere from another 2-cell embryo carrying a doxycycline-inducible let-7g gene. Bioinformatics analysis indicated that Tead4 was a potential target of let-7. Let-7 bound to the 3'UTR of Tead4 and let-7 forced expression downregulated the expression of Tead4 in mouse blastocysts. Co-injection of Tead4 mRNA partially nullified the modulatory roles of let-7a in the inner cell mass cell fate. In conclusion, a high level of let-7 at the 2-cell stage favored the formation of the inner cell mass, whereas a low level of let-7 at the 4-cell to 8-cell stage enhanced blastocyst formation. Tead4 mediated the action of let-7 on the inner cell mass cell-fate determination.

Small-extracellular vesicles and their microRNA cargo from porcine follicular fluids: the potential association with oocyte quality

Background

Ovarian follicular fluids (FFs) contain several kinds of regulatory factors that maintain a suitable microenvironment for oocyte development. Extracellular vesicles (EVs) are among the factors that play essential roles in regulating follicle and oocyte development through their cargo molecules that include microRNAs (miRNAs). This study aimed to investigate small-EV (s-EV) miRNAs in porcine FFs and their potential association with oocyte quality.

Methods

Individual aspirated oocytes were stained with lissamine green B stain (LB), a vital stain for oocyte quality, and each oocyte was classified as high-quality (unstained; HQ) or low-quality (stained; LQ). FFs corresponding to oocytes were pooled together into HQ and LQ groups. Small-EVs were isolated from FFs, characterized, and their miRNA cargo was identified using the Illumina NovaSeq sequencing platform. Additionally, s-EVs from the HQ and LQ groups were utilized to investigate their effect on oocyte development after co-incubation during in vitro maturation.

Results

A total of 19 miRNAs (including miR-125b, miR-193a-5p, and miR-320) were significantly upregulated, while 23 (including miR-9, miR-206, and miR-6516) were downregulated in the HQ compared to the LQ group. Apoptosis, p53 signaling, and cAMP signaling were among the top pathways targeted by the elevated miRNAs in the HQ group while oocyte meiosis, gap junction, and TGF-beta signaling were among the top pathways targeted by the elevated miRNAs in the LQ group. The supplementation of small-EVs during maturation does not affect the oocyte developmental rates. However, LQ s-EVs increase the proportion of oocytes with homogeneous mitochondrial distribution and decrease the proportion of heterogeneous distribution.

Conclusion

Our findings indicated that FF-EVs contain different miRNA cargos associated with oocyte quality and could affect the mitochondrial distribution patterns during oocyte maturation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40104-022-00723-1.

Role of miRNAs in preimplantation embryo development and their potential as embryo selection biomarkers

CONTEXT

MicroRNAs (miRNAs) play different roles in oocyte fertilisation, degradation of maternal transcripts, embryo development, and implantation. During in vitro fertilisation (IVF), different miRNAs are released from embryos into the spent culture media (SCM) that can potentially reflect the status of the embryo.

AIMS

This study is the assessment of miRNAs, which secreted in SCM during the IVF cycles can be used as noninvasive biomarkers to predict an embryo's ability to form a blastocyst, implant, and give live birth.

METHODS

Systematic literature search was conducted to review all recent studies about miRNAs as potential non-invasive biomarkers for selecting the best embryos in the assisted reproductive technology (ART) cycle.

KEY RESULTS

Studies have shown that levels of some miRNAs in the SCM have an association with the implantation potential and pregnancy outcome of the embryo.

CONCLUSIONS

Embryo-secreted miRNAs can be used as potential non-invasive biomarkers for selecting the best embryos in the ART cycle. Unfortunately, few human studies evaluated the association between ART outcomes and miRNAs in SCM.

IMPLICATIONS

This review can pave the way for further miRNAs transcriptomic studies on human embryo culture media and introducing a specific miRNA profile as a multivariable prediction model for embryo selection in IVF cycles.

Fyn and argonaute 2 participate in maternal-mRNA degradation during mouse oocyte maturation

Fertilization triggers physiological degradation of maternal-mRNAs, which are then replaced by embryonic transcripts. Ample evidence suggests that Argonaut 2 (AGO2) is a possible post-fertilization regulator of maternal-mRNAs degradation; but its role in degradation of maternal-mRNAs during oocyte maturation remains obscure. Fyn, a member of the Src family kinases (SFKs), and an essential factor in oocyte maturation, was reported to inhibit AGO2 activity in oligodendrocytes. Our aim was to examine the role of Fyn and AGO2 in degradation of maternal-mRNAs during oocyte maturation by either suppressing their activity with SU6656 - an SFKs inhibitor; or by microinjecting DN-Fyn RNA for suppression of Fyn and BCl-137 for suppression of AGO2. Batches of fifteen mouse oocytes or embryos were analyzed by qPCR to measure the expression level of nine maternal-mRNAs that were selected for their known role in oocyte growth, maturation and early embryogenesis. We found that Fyn/SFKs are involved in maintaining the stability of at least four pre-transcribed mRNAs in oocytes at the germinal vesicle (GV) stage, whereas AGO2 had no role at this stage. During in-vivo oocyte maturation, eight maternal-mRNAs were significantly degraded. Inhibition of AGO2 prevented the degreadation of at least five maternal-mRNAs, whereas inhibition of Fyn/SFK prevented degradation of at least five Fyn maternal-mRNAs and two SFKs maternal-mRNAs; pointing at their role in promoting the physiological degradation which occurs during in-vivo oocyte maturation. Our findings imply the involvement of Fyn/SFKs in stabilization of maternal-mRNA at the GV stage and the involvement of Fyn, SFKs and AGO2 in degradation of maternal mRNAs during oocyte maturation.

lncRNA ROR and miR-125b Predict the Prognosis in Heart Failure Combined Acute Renal Failure

Objective

To elucidate the correlation between expression levels of long noncoding RNA (lncRNA) ROR and microRNA-125b (miR-125b) with the prognosis in heart failure (HF) patients combined acute renal failure (ARF).

Methods

HF patients combined ARF (n = 90) and healthy controls (n = 90) in the same period were included in our hospital from April 2016 to December 2018. Every subject was followed up for 24 months. Serum levels of lncRNA ROR and miR-125b were detected, and their expression correlation was analyzed by Pearson correlation test. Receiver operating characteristic (ROC) curves were depicted for assessing the sensitivity and specificity of lncRNA ROR and miR-125b in diagnosing HF combined ARF.

Results

lncRNA ROR was upregulated in serum of HF patients combined ARF, and its level was positively correlated to NYHA classification. miR-125b displayed an opposite trend. In serum samples of HF combined ARF, expression level of lncRNA ROR was negatively related to that of miR-125b. Diagnostic potentials of lncRNA ROR and miR-125b in HF combined ARF were confirmed by ROC curve analyses (lncRNA ROR: AUC = 0.9199, cutoff value = 5.595, sensitivity = 92.22%, and specificity = 73.33%; miR-125b: AUC = 0.8509, cutoff value = 2.290, sensitivity = 81.11%, and specificity = 74.44%). After 2-year follow-up, 16 cases were dead. Higher incidences of death and rehospitalization were observed in HF combined ARF cases expressing higher serum level of lncRNA ROR or lower level of miR-125b.

Conclusions

Serum level of lncRNA ROR is upregulated, and miR-125b is downregulated in HF patients combined ARF. Their levels are linked to NYHA classification, which can be utilized as prognostic biomarkers in HF combined ARF.

Knockdown of lncRNA BDNF-AS inhibited the progression of multiple myeloma by targeting the miR-125a/b-5p-BCL2 axis

Purpose

This study aimed to explore the role of long non-coding RNA (lncRNA) BDNF-AS in the progression of multiple myeloma (MM).

Methods

The expression of BDNF-AS, miR-125a-5p, and miR-125b-5p in MM serum and cell lines were detected by quantitative reverse transcriptase PCR (qRT-PCR). The binding relationships between miR-125a/b-5p and BDNF-AS or Bcl-2 were predicted by Starbase and verified by luciferase reporter assay and RNA immunoprecipitation (RIP) assay. Cell proliferation was evaluated by Cell Counting Kit-8 (CCK-8) assay and 5-ethynyl-2′-deoxyuridine (EdU) staining assay. Cell migration was evaluated by wound healing assay. The expression levels of apoptosis-related proteins were evaluated by Western blot analysis. The role of BDNF-AS was also investigated in a xenograft tumor model in vivo.

Results

BDNF-AS was significantly upregulated, while miR-125a-5p and miR-125b-5p were downregulated in MM serum and corresponding cancer cell lines. Knockdown of BDNF-AS effectively inhibited the proliferation and migration of MM.1S and U266 cells, and co-transfection of miR-125a-5p or miR-125b-5p inhibitor and sh-BDNF-AS enhanced cell proliferation and migration compared with that in sh-BDNF-AS group. Knockdown of miR-125a-5p or miR-125b-5p significantly enhanced the proliferation and migration of MM.1S and U266 cells, and co-transfection of sh-Bcl-2 and miR-125a/b-5p inhibitor inhibited cell proliferation compared with that in miR-125a/b-5p inhibitor group. Moreover, knockdown of BDNF-AS increased the expression levels of apoptosis-related proteins (cleaved caspase 3 and cleaved PARP), while knockdown of miR-125a-5p or miR-125b-5p reduced the expression levels of these apoptosis-related proteins compared with knockdown of BDNF-AS. Furthermore, knockdown of BDNF-AS effectively suppressed MM tumor growth in vivo.

Conclusion

Our findings revealed that knockdown of BDNF-AS inhibited the progression of MM by targeting the miR-125a/b-5p-Bcl-2 axis, indicating that BDNF-AS might serve as a novel drug target for MM.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12979-021-00258-5.

MiR-125 Family in Cardiovascular and Cerebrovascular Diseases

Cardiovascular and cerebrovascular diseases are a serious threaten to the health of modern people. Understanding the mechanism of occurrence and development of cardiovascular and cerebrovascular diseases, as well as reasonable prevention and treatment of them, is a huge challenge that we are currently facing. The miR-125 family consists of hsa-miR-125a, hsa-miR-125b-1 and hsa-miR-125b-2. It is a kind of miRNA family that is highly conserved among different species. A large amount of literature shows that the lack of miR-125 can cause abnormal development of the cardiovascular system in the embryonic period. At the same time, the miR-125 family participates in the occurrence and development of a variety of cardiovascular and cerebrovascular diseases, including myocardial ischemia, atherosclerosis, ischemia-reperfusion injury, ischemic stroke, and heart failure directly or indirectly. In this article, we summarized the role of the miR-125 family in the development and maturation of cardiovascular system, the occurrence and development of cardiovascular and cerebrovascular diseases, and its important value in the current fiery stem cell therapy. In addition, we presented this in the form of table and diagrams. We also discussed the difficulties and challenges faced by the miR-125 family in clinical applications.

MiR-290 family maintains developmental potential by targeting p21 in mouse pre-implantation embryos

The miR-290 family is a mouse-specific microRNA cluster, which maintains mouse embryonic stem cells (ESCs) pluripotency by increasing OCT3/4 and C-MYC expression. However, its functions in mouse pre-implantation embryos remain unclear, especially during zygotic genome activation (ZGA). In this study, miR-290 family expression increased from the two-cell embryo stage through the blastocyst stage. Inhibition of miR-294-3p/5p did not affect ZGA initiation or embryo development, whereas pri-miR-290 knockdown decreased ZGA gene expression and slowed embryonic development. In addition, pluripotency decreased in ESCs derived from pri-miR-290 knockdown blastocysts. To clarify the mechanism of action, 33 candidate miR-294-3p target genes were screened from three databases, and miR-294-3p directly targeted the 3'-untranslated region of Cdkn1a (p21) mRNA. Similar to pri-miR-290 knockdown, P21 overexpression impeded embryonic development, whereas simultaneous overexpression of P21 and pri-miR-290 partially rescued embryonic development. The results indicate that the miR-290 family participates in promoting ZGA process and maintaining developmental potency in embryos by targeting p21.

miR-125a-5p increases cellular DNA damage of aging males and perturbs stage-specific embryo development via Rbm38-p53 signaling

An increasing number of men are fathering children at an older age than in the past. While advanced maternal age has long been recognized as a risk factor for adverse reproductive outcomes, the influence of paternal age on reproduction is incompletely comprehended. Herein, we found that miR‐125a‐5p was upregulated in the sperm of aging males and was related to inferior sperm DNA integrity as an adverse predictor. Moreover, we demonstrated that miR‐125a‐5p suppressed mitochondrial function and increased cellular DNA damage in GC2 cells. We also found that miR‐125a‐5p perturbed embryo development at specific morula/blastocyst stages. Mechanistically, we confirmed that miR‐125a‐5p disturbed the mitochondrial function by targeting Rbm38 and activating the p53 damage response pathway, and induced a developmental delay in a p21‐dependent manner. Our study revealed an important role of miR‐125a‐5p in sperm function and early embryo development of aging males, and provided a fresh view to comprehend the aging process in sperm.

The Biological Function of Extracellular Vesicles during Fertilization, Early Embryo-Maternal Crosstalk and Their Involvement in Reproduction: Review and Overview

Secretory extracellular vesicles (EVs) are membrane-enclosed microparticles that mediate cell to cell communication in proximity to, or distant from, the cell of origin. Cells release a heterogeneous spectrum of EVs depending on their physiologic and metabolic state. Extracellular vesicles are generally classified as either exosomes or microvesicles depending on their size and biogenesis. Extracellular vesicles mediate temporal and spatial interaction during many events in sexual reproduction and supporting embryo-maternal dialogue. Although many omic technologies provide detailed understanding of the molecular cargo of EVs, the difficulty in obtaining populations of homogeneous EVs makes difficult to interpret the molecular profile of the molecules derived from a miscellaneous EV population. Notwithstanding, molecular characterization of EVs isolated in physiological and pathological conditions may increase our understanding of reproductive and obstetric diseases and assist the search for potential non-invasive biomarkers. Moreover, a more precise vision of the cocktail of biomolecules inside the EVs mediating communication between the embryo and mother could provide new insights to optimize the therapeutic action and safety of EV use.

lncRNA CERS6-AS1 as ceRNA promote cell proliferation of breast cancer by sponging miR-125a-5p to upregulate BAP1 expression

Long noncoding RNAs (lncRNAs) can act as oncogene and tumor suppressor genes in many types of cancers including breast cancer (BC). Our previous study has indicated microRNA (miR)-125a-5p was downregulated and function as a tumor suppressor in BC. However, its upstream regulation mechanism is still unclear. In this study, we used bioinformatics algorithms, RNA pulldown assay, and dual-luciferase reports assay to predict and confirm lncRNA CERS6-AS1 interacted with miR-125a-5p. Then we found CERS6-AS1 was upregulated in BC tissues. Experimental results of tumor growth in nude mice show that CERS6-AS1 promotes tumor growth. Furthermore, CERS6-AS1 regulated BC susceptibility gene 1-associated protein 1 (BAP1) expression via sponging miR-125a-5p via Western blot analysis and quantitative polymerase chain reaction arrays. Finally, we showed that miR-125a-5p had opposing effects to those of CERS6-AS1 on BC cells, demonstrating that CERS6-AS1 may promote cell proliferation and inhibit cell apoptosis via sponging miR-125a-5p. Our results indicated CERS6-AS1 promote BC cell proliferation and inhibit cell apoptosis via sponging miR-125a-5p to upregulate BAP1 expression.

Distinct expression patterns of seven crucial microRNAs during early embryonic development in medaka (Oryzias latipes)

MicroRNAs (i.e. miRNAs) are small non-coding RNAs that play essential modulation roles in embryonic development in vertebrates. Paternal and maternal miRNAs contribute to the development of post-fertilization embryo and zygotic genome activation. The pattern of expression and their roles in embryonic development of medaka are not clearly understood. The present study, therefore, examined a temporal expression of seven miRNAs, ola-let-7a, ola-miR-202-3p, ola-miR-126-3p, ola-miR-122, ola-miR-92a, ola-miR-125a-3p and ola-miR-430a in sperm, oocytes, and embryos during early developmental stages. Three unique expression patterns of miRNAs were observed. ola-let7a, ola-miR-202-3p and ola-miR-126-3p showed both paternal and maternal expression, and ola-miR-122, ola-miR-92a, ola-miR-125a-3p showed maternal expression only. The expression of six out of seven miRNAs significantly decreased after maternal-zygotic transition (MZT), whereas ola-miR-430a expression initiated only after MZT. The temporal dynamic expression of these miRNAs suggests their potential roles in early embryogenesis and genome-zygotic activation in medaka.

Extracellular vesicles: Multi-signal messengers in the gametes/embryo-oviduct cross-talk

Extracellular vesicles (EVs) have emerged as novel cell-to-cell communication mediators in physiological and pathological scenarios. Their ability to transfer their molecular cargo (RNAs, proteins and lipids) from one cell to another, in the vicinity or far from the cell of origin, together with their capacity of exerting a functional impact on the target cell make them valuable diagnostic tools as well as therapeutic vectors in a variety of diseases. In the reproductive field, there is a growing interest in the role of EVs in gamete/embryo-maternal communication and their potential implications in the reproductive success. In this review, we provide current knowledge of EVs secreted by the oviduct (oEVs) and embryos (eEVs), since both have been proposed as key players in the crucial two-way dialogue between the oviduct (lining epithelium and secretions) and the embryo that ensures successful pregnancy. Both oEVs and eEVs molecular cargos and their potential role as multi-signal messengers in the gametes/embryo-oviduct cross-talk and in the embryo-to-embryo communication in different species are also addressed. Eventually, a comparative analysis between oEVs and eEVs has been performed to shed some light on common and specific cargos responsible for their functions supporting the early reproductive events and as prime candidate molecules for improving fertility and assisted reproductive technologies outcomes.

Transfection of exogenous DNA complexed to cationic dendrimer induces alterations of bovine sperm microRNAome

MicroRNAs have been hypothesized to be involved in the regulation of male fertility potential. The primary aim of our study was to demonstrate the effects of transfection with dendrimer nanostructure on the parameters of bovine sperm quality and to investigate whether the microRNA profile could be disturbed after cationic dendrimer-mediated exogenous DNA transfection of bovine spermatozoa. The binding of exogenous DNA was significantly increased when dendrimer-based transfection was implemented. However, cationic dendrimer transfection induced detrimental changes in the kinetics and sperm quality parameters, such as membrane integrity, acrosome reaction, and mitochondrial membrane potential, when compared to the control group. Sperm microRNA sequencing revealed 218 known and 106 novel microRNAs in the sperm samples, among which nine were dysregulated after transfection (one was upregulated and eight were downregulated), in comparison to the non-transfected sperm. All the dysregulated microRNAs were related to sperm quality and embryonic development. These results suggest that the transfection process using the dendrimer nanostructure has an impact on the quality and microRNA profile of bovine sperm.

MicroRNA-451 is downregulated in the follicular fluid of women with endometriosis and influences mouse and human embryonic potential

BACKGROUND

Previous work demonstrated that there are numerous miRNAs in human follicular fluids, some of which are associated with reproductive diseases. In the current study, we sought to determine whether microRNAs (miRNAs) in the follicular fluid (FF) are differentially expressed between women with and without endometriosis and to uncover the association of miRNAs with the oocyte and embryonic development potential.

METHODS

FF was harvested from 30 women with endometriosis and 30 women without who underwent in vitro fertilization treatment at the University Hospital between February and December 2016. The FF samples were subjected to miRNA profiling and validation via quantitative reverse transcription polymerase chain reaction analysis. Mouse/human metaphase-I (MI) oocytes were harvested and micro-injected with an miR-451 inhibitor, and the effects of miR-451 knockdown on Wnt/WNT signalling genes were investigated.

RESULTS

Oocyte number, fertilization rate, and number of available embryos were decreased significantly in women with endometriosis relative to those without endometriosis. Hsa-miR-451 in FF was downregulated in endometriosis patients relative to control subjects (P < 0.01). Moreover, the proportions of mouse/human MI oocytes that developed into 2-pronuclei (2PN), 2-cell, 8-10-cell and blastocyst-stage embryos were affected by miR-451 knockdown in mouse/human oocytes. Components of the Wnt signalling pathway were aberrantly expressed in the mouse/human oocytes and embryos in the miR-451 inhibitor-injected group.

CONCLUSIONS

miR-451 was downregulated in FF samples from endometriosis patients and was modestly effective in distinguishing endometriosis patients from non-endometriosis patients. miR-451 downregulation in mouse and human oocytes affected pre-implantation embryogenesis by suppressing the Wnt signalling pathway. This miRNA might serve as a novel biomarker of oocyte and embryo quality in assisted reproductive treatment.

Oxygen tension modulates extracellular vesicles and its miRNA contents in bovine embryo culture medium

The biotechnology for in vitro embryo production is becoming increasingly popular, being applied to humans and domestic animals. Embryo development can be achieved with either 20% or 5% oxygen tension. The extracellular vesicles (EVs) are secreted by different cell types and carry bioactive materials. Our objective was to determine the secretion pattern and micro RNA (miRNA) contents of EVs released in the bovine embryo culture environment-embryo and cumulus cell monolayer-on Days 3 and 7 of in vitro culture under two different oxygen tensions: High (20%) and low (5%). The EVs were isolated from the medium and analyzed to determine size, concentration, and miRNA levels. EVs concentration in low oxygen tension increased on Day 3 and decreased on Day 7. Additionally, altered EV miRNAs derived from the embryo-cumulus culture medium were predicted to regulate survival and proliferation-related pathways on Days 3 and 7. Moreover, miR-210 levels decreased in EVs isolated from the culture medium under high oxygen tension suggesting that this miRNA can be used as a marker for normoxia since it is associated with low oxygen tension. In summary, this study provides knowledge of the oxygen tension effects on EVs release and content, and potentially, on cell-to-cell communication during in vitro bovine embryo production.

microRNA expression profile in porcine oocytes with different developmental competence derived from large or small follicles

Oocyte developmental competence is acquired during folliculogenesis and regulated by complex molecular mechanisms. Several molecules are involved in these mechanisms, including microRNAs (miRNAs) that are essential for oocyte-specific processes throughout the development. The objective of this study was to identify the expression profile of miRNAs in porcine oocytes derived from follicles of different sizes using RNA deep sequencing. Oocytes were aspirated from large (LO; 3-6 mm) or small (SO; 1.5-1.9 mm) follicles and tested for developmental competence and chromatin configurations. Small RNA libraries were constructed from both groups and then sequenced in an Illumina NextSeq. 500. Oocytes from the LO group exhibited higher developmental competence and different chromatin configuration compared with oocytes from the SO group. In total, 167 and 162 known miRNAs were detected in the LO and SO groups, respectively. MiR-205, miR-16, miR-148a-3p, and miR-125b were among the top 10 highly expressed miRNAs in both groups. Eight miRNAs were differentially expressed (DE) between both groups. Target gene prediction and pathway analysis revealed 46 pathways that were enriched with miRNA-target genes. The oocyte meiosis pathway and signaling pathways including FoxO, PI3K-Akt, and cAMP were predictably targeted by DE miRNAs. These results give more insights into the potential role of miRNAs in regulating the oocyte development.

Urinary concentrations of phenols and phthalate metabolites reflect extracellular vesicle microRNA expression in follicular fluid

BACKGROUND

Phenols and phthalates are potential endocrine disrupting chemicals (EDCs) that are associated with adverse health outcomes. These EDCs dysregulate a number of biomolecules and pathways, including microRNAs. MicroRNAs can be carried in transport systems called extracellular vesicles (EVs) that are present in most biofluids. EVs in the follicular fluid, which fills the ovarian follicle and influences oocyte developmental competency, carry microRNAs (EV-miRNAs) that have been associated with In Vitro Fertilization (IVF) outcomes. However, it remains unclear whether EDCs affect EV-miRNAs in follicular fluid.

OBJECTIVES

This study sought to determine whether urinary concentrations of phenols and phthalates biomarkers are associated with EV-miRNAs expression in follicular fluid collected from women undergoing IVF treatment.

METHODS

This cross-sectional study included 130 women recruited between January 2014 and August 2016 in a tertiary university-affiliated hospital. Participants provided urine samples during ovarian stimulation and on the day of oocyte retrieval. We assessed urinary concentrations of five phenols, eight phthalate metabolites, and one phthalate alternative metabolite. EV-miRNAs were isolated from follicular fluid and their expression profiles were measured using the TaqMan Open Array® Human microRNA panel. We fitted multivariable linear regression models and principal component analysis to examine associations between individual and molar sums of exposure biomarkers and EV-miRNAs.

RESULTS

Of 754 miRNAs tested, we detected 133 EV-miRNAs in the microRNA array which expressed in at least 50% of the follicular fluid samples. After adjusting for multiple testing, we identified eight EV-miRNAs associated with individual phenols and phthalate metabolites, as well as molar ΣDEHP that met a q < 0.10 false-discovery rate (FDR) threshold. Hsa-miR-125b, hsa-miR-106b, hsa-miR-374a, and hsa-miR15b was associated with mono(2-ethylhexyl) phthalate concentrations, hsa-let-7c with concentrations mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP), mono-2-ethyl-5-oxohexyl phthalate (MEOHP), mono-2-ethyl-5-carboxypentyl phthalate (MECPP), and the sum of metabolites of di(2-ethylhexyl) phthalate, hsa-miR-24 with mono-n-butyl phthalate concentrations, hsa-miR-19a with cyclohexane-1,2-dicarboxylic acid monohydroxy isononyl ester (MHiNCH), and hsa-miR-375 with ethyl paraben concentrations. Using Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses, gene targets and pathways of these EV-miRNAs were predicted in silico and 17 KEGG FDR-significant pathways related to follicular development and oocyte competence were identified.

CONCLUSIONS

Our results show that urinary concentrations of select phenol and phthalate metabolites are correlated with altered EV-miRNAs expression in follicular fluid. These findings may provide insight regarding the molecular mechanisms underlying adverse effects of phenol and phthalate exposure on female fertility.

MiR-125b-2 Knockout in Testis Is Associated with Targeting to the PAP Gene, Mitochondrial Copy Number, and Impaired Sperm Quality

It has been reported that the miR-125 family plays an important role in regulating embryo development. However, the function of miR-125b-2 in spermatogenesis remains unknown. In this study, we used a model of miR-125b knockout (KO) mice to study the relationship between miR-125b-2 and spermatogenesis. Among the KO mice, the progeny test showed that the litter size decreased significantly (p = 0.0002) and the rate of non-parous females increased significantly from 10% to 38%. At the same time, the testosterone concentration increased significantly (p = 0.007), with a remarkable decrease for estradiol (p = 0.02). Moreover, the sperm count decreased obviously (p = 0.011) and the percentage of abnormal sperm increased significantly (p = 0.0002). The testicular transcriptome sequencing revealed that there were 173 up-regulated genes, including Papolb (PAP), and 151 down-regulated genes in KO mice compared with wild type (WT). The Kyoto Encyclopedia of Genes and Genomes (KEGG) and gene ontology (GO) analysis showed that many of these genes were involved in sperm mitochondrial metabolism and other cellular biological processes. Meanwhile, the sperm mitochondria DNA (mtDNA) copy number increased significantly in the KO mice, but there were no changes observed in the mtDNA integrity and mutations of mt-Cytb, as well as the mt-ATP6 between the WT mice and KO mice. In the top 10 up-regulated genes, PAP, as a testis specific expressing gene, affect the process of spermatogenesis. Western blotting and the Luciferase assay validated that PAP was the target of miR-125b-5p. Intriguingly, we also found that both miR-125b and PAP were only highly expressed in the germ cells (GC) instead of in the Leydig cells (LC) and Sertoli cells (SC). Additionally, miR-125b-5p down regulated the secretion of testosterone in the TM3 cell by targeting PAP (p = 0.021). Our study firstly demonstrated that miR-125b-2 regulated testosterone secretion by directly targeting PAP, and increased the sperm mtDNA copy number to affect semen quality. The study indicated that miR-125b-2 had a positive influence on the reproductive performance of animals by regulating the expression of the PAP gene, and could be a potential drugs and diagnostic target for male infertility.

Microarray analysis of miRNAs during hindgut development in rat embryos with ethylenethiourea‑induced anorectal malformations

Anorectal malformations (ARMs) are one of the most common congenital malformations of the digestive tract; however, the pathogenesis of this disease remains to be fully elucidated. MicroRNAs (miRNAs) are important in gastrointestinal development and may be involved in the pathogenesis of ARMs. The present study aimed to profile miRNAs and examine their potential functions in rats with ethylenethiourea (ETU)-induced ARMs. Pregnant Wistar rats (n=36) were divided randomly into ETU-treated and control groups. The rats in the ETU-treated group were gavage-fed 1% ETU (125 mg/kg) on gestational day 10 (GD10), whereas the control group rats received a corresponding dose of saline. Embryos were harvested by cesarean section on GD14, GD15 and GD16. Hindgut tissue was isolated from the fetuses for RNA extraction and microarray analysis, followed by bioinformatics analysis and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) validation. Overall, 38 miRNAs were differentially expressed (all upregulated) on GD14, 49 (32 upregulated and 17 downregulated) on GD15, and 42 (all upregulated) on GD16 in the ARM group compared with the normal group. The top 18 miRNAs with |log₂(fold change)| >4.25 were selected for further bioinformatics analysis. Among these miRNAs, five were differentially expressed at two time-points and were involved in ARM-associated signaling pathways. The RT-qPCR analysis revealed that three miRNA (miR), miR-125b-2-3p, miR-92a-2-5p and miR-99a-5p, were significantly differentially expressed in rats with ARMs compared with the normal group. In conclusion, the results suggested that the differential expression of miR-125b-2-3p, miR-92a-2-5p and miR-99a-5p during key time-points of anorectal formation in rats may have functions in the pathogenesis of ARM.

miRNA-125b-5p Suppresses Hypothyroidism Development by Targeting Signal Transducer and Activator of Transcription 3

Background

A deficiency of maternal thyroid hormones (THs) during pregnancy has severe impacts on fetal brain development. Neural stem cells (NSCs) are major targets of THs and provided a powerful model to explore the underlying mechanism of THs during brain development. Although miRNA-125 might be associated with the NSCs differentiation, the relationship between miR-125 and hypothyroidism (HypoT) development remains unclear.

Material/Methods

In our study, we screened a differentially expressed gene miR-125b-5p from brain between euthyroid (EuT) and HypoT rats. In vitro, we employed anion exchange resin to remove THs to stimulate HypoT. QRT-PCR and Western blot were used to examine the expression of signal transducer and activator of transcription 3 (Stat3). The relationship between miR-125b-5p and Stat3 was detected via a dual-luciferase assay.

Results

QRT-PCR results showed that the level of miR-125b-5p in HypoT rat brains was significantly suppressed, suggesting some relationship between miR-125b-5p and HypoT. In C17.2, miR-125b-5p promoted cell differentiation into neurons by regulating the expression of tubulin beta chain 3 (TUBB3) and glial fibrillary acid protein (GFAP). QRT-PCR and Western blot results revealed that miR-125b-5p mimic modulated the contents of total Stat3 and p-Stat3. A dual-luciferase assay showed that miR-125b-5p negatively regulated the expression of Stat3 by binding with the first site in 3′ UTR of Stat3.

Conclusions

These results revealed Stat3 is a new target of miR-125b-5p and revealed the mechanism of miR-125b-5p suppressing HypoT development. These findings provide a new target for HypoT therapy.

MicroRNA-125b is a key epigenetic regulatory factor that promotes nuclear transfer reprogramming

Somatic cell nuclear transfer (SCNT)-mediated reprogramming is a rapid, efficient, and sophisticated process that reprograms differentiated somatic cells to a pluripotent state. However, many factors in this elaborate reprogramming process remain largely unknown. Here, we report that the microRNA (miR) miR-125b is an important component of SCNT-mediated reprogramming. Luciferase reporter assay, quantitative PCR, and Western blotting demonstrated that miR-125b directly binds the 3'-untranslated region of SUV39H1, encoding the histone-lysine N-methyltransferase SUV39H1, to down-regulate histone H3 lysine-9 tri-methylation (H3K9me3) in SCNT embryos. Furthermore, the miR-125b/SUV39H1 interaction induced loss of SUV39H1-mediated H3K9me3, caused heterochromatin relaxation, and promoted the development of SCNT embryos. Transcriptome analyses of SCNT blastomeres indicated that HNF1 homeobox B (HNF1B), a gene encoding a transcription factor downstream of and controlled by the miR-125b/SUV39H1 axis, is important for conferring developmental competence on preimplantation embryos. We conclude that miR-125b promotes SCNT-mediated nuclear reprogramming by targeting SUV39H1 to decrease the deposition of repressive H3K9me3 modifications.