Differential expression of microRNAs in TM3 Leydig cells of mice treated with brain-derived neurotrophic factor

Role of miR-300-3p in Leydig cell function and differentiation: A therapeutic target for obesity-related testosterone deficiency

MicroRNAs (miRNAs) regulate various cellular functions, but their specific roles in the regulation of Leydig cells (LCs) have yet to be fully understood. Here, we found that the expression of miR-300-3p varied significantly during the differentiation from progenitor LCs (PLCs) to adult LCs (ALCs). High expression of miR-300-3p in PLCs inhibited testosterone production and promoted PLC proliferation by targeting the steroidogenic factor-1 (Sf-1) and transcription factor forkhead box O1 (FoxO1) genes, respectively. As PLCs differentiated into ALCs, the miR-300-3p expression level significantly decreased, which promoted testosterone biosynthesis and suppressed proliferation of ALCs by upregulating SF-1 and FoxO1 expression. The LH/METTL3/SMURF2/SMAD2 cascade pathway controlled miR-300-3p expression, in which luteinizing hormone (LH) upregulated SMAD-specific E3 ubiquitin protein ligase 2 (SMURF2) expression through methyltransferase like 3 (METTL3)-mediated Smurf2 N6-methyladenosine modification. The Smurf2 then suppressed miR-300 transcription by inhibiting SMAD family member 2 (SMAD2) binding to the promoter of miR-300. Notably, miR-300-3p was associated with an obesity-related testosterone deficiency in men and the inhibition of miR-300-3p effectively rescued testosterone deficiency in obese mice. These findings suggested that miR-300-3p plays a pivotal role in LC differentiation and function, and could be a promising diagnostic or therapeutic target for obesity-related testosterone deficiency.

Identification of ceRNA network to explain the mechanism of cognitive dysfunctions induced by PS NPs in mice

Plastics breaking down of larger plastics into smaller ones (microplastics and nanoplastic) as potential threats to the ecosystem. Previous studies demonstrate that the central nervous system (CNS) is a vulnerable target of nanoplastics. However, the potentially epigenetic biomarkers of nanoplastic neurotoxicity in rodent models are still unknown. The present research aimed to determine the role of competing endogenous RNA (ceRNA) in the process of polystyrene nanoplastics (PS NPs) exposure-induced nerve injury. The study was designed to investigate whether 25 nm PS NPs could cause learning dysfunction and to elucidate the underlying mechanisms in mice. A total of 40 mice were divided into 4 groups and were exposed to PS NPs (0, 10, 25, 50 mg/kg). Chronic toxicity was introduced in mice by administration of oral gavage for 6 months. The evaluation included assessment of their behavior, pathological investigation and determination of the levels of reactive oxygen species (ROS) and DNA damage. RNA-Seq was performed to detect the expression levels of circRNAs, miRNAs and mRNAs in PFC samples of mice treated with 0 and 50 mg/kg PS NPs. The results indicated that exposure of mice to PS NPs caused a dose-dependent cognitive decline. ROS levels and DNA damage were increased in the PFC following exposure of the mice to PS NPs. A total of 987 mRNAs, 29 miRNAs and 67 circRNAs demonstrated significant differences between the 0 and 50 mg/kg PS NPs groups. Functional enrichment analyses indicated that PS NPs may induce major injury in the synaptic function. A total of 96 mRNAs, which were associated with synaptic dysfunction were identified. A competing endogenous RNA (ceRNA) network containing 27 circRNAs, 19 miRNAs and 35 synaptic dysfunction-related mRNAs was constructed. The present study provided insight into the molecular events associated with nanoplastic toxicity and induction of cognitive dysfunction.

Altered White Matter and microRNA Expression in a Murine Model Related to Williams Syndrome Suggests That miR-34b/c Affects Brain Development via Ptpru and Dcx Modulation

Williams syndrome (WS) is a multisystem neurodevelopmental disorder caused by a de novo hemizygous deletion of ~26 genes from chromosome 7q11.23, among them the general transcription factor II-I (GTF2I). By studying a novel murine model for the hypersociability phenotype associated with WS, we previously revealed surprising aberrations in myelination and cell differentiation properties in the cortices of mutant mice compared to controls. These mutant mice had selective deletion of Gtf2i in the excitatory neurons of the forebrain. Here, we applied diffusion magnetic resonance imaging and fiber tracking, which showed a reduction in the number of streamlines in limbic outputs such as the fimbria/fornix fibers and the stria terminalis, as well as the corpus callosum of these mutant mice compared to controls. Furthermore, we utilized next-generation sequencing (NGS) analysis of cortical small RNAs' expression (RNA-Seq) levels to identify altered expression of microRNAs (miRNAs), including two from the miR-34 cluster, known to be involved in prominent processes in the developing nervous system. Luciferase reporter assay confirmed the direct binding of miR-34c-5p to the 3'UTR of PTPRU-a gene involved in neural development that was elevated in the cortices of mutant mice relative to controls. Moreover, we found an age-dependent variation in the expression levels of doublecortin (Dcx)-a verified miR-34 target. Thus, we demonstrate the substantial effect a single gene deletion can exert on miRNA regulation and brain structure, and advance our understanding and, hopefully, treatment of WS.

MicroRNA-125a-5p modulates the proliferation and apoptosis of TM4 Sertoli cells by targeting RAB3D and regulating the PI3K/AKT signaling pathway

Sertoli cells are cells that provide protection and nutrition for developing sperm. Each stage of sperm development occurs on the surface of Sertoli cells. MicroRNA (MiR)-125a-5p is involved in male reproduction. The current research aimed to probe the role of miR-125a-5p in Sertoli cell function. Functionally, miR-125a-5p knockdown facilitated Sertoli cell proliferation, while miR-125a-5p overexpression suppressed Sertoli cell proliferation, as evidenced by 5-ethynyl-20-deoxyuridine incorporation assay. Additionally, miR-125a-5p knockdown inhibited Sertoli cell apoptosis, while miR-125a-5p upregulation facilitated Sertoli cell apoptosis, as evidenced by flow cytometry analysis. Computationally, we identified four predicted mRNA targets of miR-125a-5p. Based on the results of luciferase reporter assay, miR-125a-5p was confirmed to bind to the predicted sequence in the Ras-related protein Rab-3D (RAB3D) 3'UTR. Rescue experiments showed that miR-125a-5p suppressed the proliferative ability of TM4 Sertoli cells and facilitated their apoptosis by targeting RAB3D. Finally, our data confirmed that miR-125a-5p and RAB3D modulated activation of the PI3K/AKT pathway. In conclusion, our data showed that miR-125a-5p regulated Sertoli cell proliferation and apoptosis by targeting RAB3D and regulating the PI3K/AKT pathway.

Brain-derived neurotrophic factor (BDNF) expression and function in the mammalian reproductive Tract

BACKGROUND

Neurotrophins of the nerve growth factor family are soluble polypeptides that are best known for their role in nerve growth, survival and differentiation in the central nervous system. A growing body of literature shows that neurotrophins and their receptors are also expressed throughout the reproductive tract.

OBJECTIVE AND RATIONALE

Neurotrophins are key regulatory proteins in reproductive physiology during development and throughout adult life. Of the neurotrophins, the literature describing the expression and function of brain-derived neurotrophic factor (BDNF) and its high-affinity receptor, neurotrophin receptor kinase-2 (NTRK2), has been expanding rapidly. We therefore conducted a systematic inductive qualitative review of the literature to better define the role of the BDNF in the reproductive tract. We postulate that BDNF and NTRK2 are central regulatory proteins throughout the reproductive system.

SEARCH METHODS

An electronic search of Medline (PubMed) and Web of Science for articles relating to BDNF and the reproductive system was carried out between January 2018 and February 2019.

OUTCOMES

In the ovary, BDNF expression and levels have been linked with follicle organisation during ovarian development, follicle recruitment and growth and oocyte maturation. In the endometrium, BDNF is involved in cell proliferation and neurogenesis. In contrast, literature describing the role of BDNF in other reproductive tissues is sparse and BDNF-NTRK2 signalling in the male reproductive tract has been largely overlooked. Whilst estradiol appears to be the primary regulator of BDNF expression, we also identified reports describing binding sites for glucocorticoid and myocyte enhancer factor-2, a calcium-response element through activation of an N-methyl-D-aspartate (NMDA) receptor, and aryl hydrocarbon receptor nuclear transporter protein-4 (ARNT) response elements in promoter regions of the BDNF gene. Expression is also regulated by multiple microRNAs and post-translational processing of precursor proteins and intracellular shuttling. BDNF-NTRK2 signalling is modulated through tissue specific receptor expression of either the full-length or truncated NTRK2 receptor; however, the functional importance remains to be elucidated. Dysregulation of BDNF expression and circulating concentrations have been implicated in several reproductive disorders including premature ovarian failure, endometriosis, pre-eclampsia, intra-uterine growth restriction (IUGR) and several reproductive cancers.

WIDER IMPLICATIONS

We conclude that BDNF and its receptors are key regulatory proteins central to gonadal development, ovarian regulation and uterine physiology, as well as embryo and placenta development. Furthermore, dysregulation of BDNF-NTRK2 in reproductive diseases suggests their potential role as candidate clinical markers of disease and potential therapeutic targets.

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Zearalenone (ZEA) is a non-steroidal estrogen mycotoxin produced by several Gibberella and Fusarium species. Accumulating evidence has indicated that ZEA strongly stimulates cell proliferation. However the detailed molecular and cellular mechanisms of ZEA-mediated induction of cell proliferation have not yet been completely explained. The aim of this study was to detect the role of miRNAs in ZEA-mediated induction of cell proliferation. The effects of ZEA on cell proliferation were assessed using a cell counting kit assay and xCELLigence system. Micro-RNA sequencing was performed after treatment of TM3 cells with ZEA (0.01 μmol/L) for different time periods (0, 2, 6 and 18 h). Cell function and pathway analysis of the miRNA target genes were performed by Ingenuity Pathway Analysis (IPA). We found that ZEA promotes TM3 cell proliferation at low concentrations. miRNA sequenceing revealed 66 differentially expressed miRNAs in ZEA-treated cells in comparison to the untreated control ( p < 0.05). The miRNA sequencing indicated that compared to control group, there were 66 miRNAs significant change (p < 0.05) in ZEA-treated groups. IPA analysis showed that the predicated miRNAs target gene involved in cell Bio-functions including cell cycle, growth and proliferation, and in signaling pathways including MAPK and RAS-RAF-MEK-ERK pathways. Results from flow cytometry and Western Blot analysis validated the predictions that ZEA can affect cell cycle, and the MAPK signaling pathway. Taking these together, the cell proliferation induced ZEA is regulated by miRNAs. The results shed light on the molecular and cellular mechanisms for the mediation of ZEA to induce proliferation.

Analysis of the miRNA Expression Profiles in the Zearalenone-Exposed TM3 Leydig Cell Line

Zearalenone (ZEN), an important environmental pollutant, can cause serious harm to human and animal health. The aim of our study was to examine the effect of zearalenone (ZEN) on miRNA expression profiles in the mouse Leydig cell line (TM3 Leydig cell line) by miRNA sequencing. The effect of ZEN on the viability of TM3 Leydig cells was verified by Cell Counting Kit-8 (CCK-8). MiRNA sequencing was performed 24 h after the exposure of TM3 Leydig cells with 50 μmol/L of ZEN. Bioinformatics predicted the miRNA target genes, performed Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses, and conducted miRNA-gene-pathway mapping to show the relationship between miRNA, the target gene, and the signalling pathway. The expression levels of miRNA and the miRNA target genes associated with ZEN toxicology were verified by quantitative real-time polymerase chain reaction. The miRNA sequencing revealed a significant change (p < 0.05) in the 197 miRNAs in the ZEN-treated and control groups, among which 86 were up-regulated and 111 were down-regulated. GO analysis of the target genes of these miRNAs indicated various biological functions. KEGG analysis showed that the predicted miRNA target genes were involved in signalling pathways, such as cancer, apoptosis, and oxidation, namely, the Ras signalling pathway, Rap1 signalling pathway, PI3K-AKT signalling pathway, Foxo signalling pathway, and AMPK signalling pathway. These results suggest that ZEN, as an estrogen-like toxin, is regulated by microRNAs. Our results can help to examine the toxicological effects of ZEN-regulated miRNAs on germ cells.

Identification of key genes in cleft lip with or without cleft palate regulated by miR-199a-5p

BACKGROUND

Cleft lip with or without cleft palate (CL/P) is one of the most common congenital defects, which etiology involves both genetic and environmental factors. Previous studies have shown that miR-199a-5p may mediate the occurrence of CL/P. However, the key target genes regulated by miR-199a-5p are not clear. In this study, we employed a systematic bioinformatics analysis of target genes regulated by miR-199a-5p which may be involved in CL/P.

METHODS

The miRBase, Human miRNA tissue atlas, miRecords, miRpathDB, miRWalk, miRTarBase, DIANA-TarBase (v7.0), Literature search, DAVID software, Cytoscape plugin ClueGO + Cluepedia app, MalaCards, TargetScanhuman7.1, Venny 2.1, STRING and GEO databases were comprehensive employed to identify the key genes regulated by miR-199a-5p associated with CL/P.

RESULTS

Total 429 experimentally validated target genes were obtained from five miRNAs related databases. Expressions of miR-199a-5p and its experimentally validated target genes were elevated in bone, brain and skin. KEGG pathway analysis revealed that the target genes were enriched in focal adhesion, microRNAs in cancer and hippo signaling pathway. Biological process categorization revealed that significant portions of the target genes were grouped as transcription, DNA-templated. Total eight intersection genes were identified by using MalaCards and TargetScanhuman7.1. The target gene transforming growth factor alpha (TGFA) of miR-199a-5p involved in CL/P is screened and verified.

CONCLUSION

MiR-199a-5p may mediate CL/P by regulating key target gene TGFA. The study may contribute to a better understanding of the etiology of CL/P.