miR-34c works downstream of p53 leading to dairy goat male germline stem-cell (mGSCs) apoptosis

Role of miRNAs in assisted reproductive technology

Cellular proteins and the mRNAs that encode them are key factors in oocyte and sperm development, and the mechanisms that regulate their translation and degradation play an important role during early embryogenesis. There is abundant evidence that expression of microRNAs (miRNAs) is crucial for embryo development and are highly involved in regulating translation during oocyte and early embryo development. MiRNAs are a group of short (18-24 nucleotides) non-coding RNA molecules that regulate post-transcriptional gene silencing. The miRNAs are secreted outside the cell by embryos during preimplantation embryo development. Understanding regulatory mechanisms involving miRNAs during gametogenesis and embryogenesis will provide insights into molecular pathways active during gamete formation and early embryo development. This review summarizes recent findings regarding multiple roles of miRNAs in molecular signaling, plus their transport during gametogenesis and embryo preimplantation.

The role of p53 in male infertility

The tumor suppressor p53 is a transcription factor involved in a variety of crucial cellular functions, including cell cycle arrest, DNA repair and apoptosis. Still, a growing number of studies indicate that p53 plays multiple roles in spermatogenesis, as well as in the occurrence and development of male infertility. The representative functions of p53 in spermatogenesis include the proliferation of spermatogonial stem cells (SSCs), spermatogonial differentiation, spontaneous apoptosis, and DNA damage repair. p53 is involved in various male infertility-related diseases. Innovative therapeutic strategies targeting p53 have emerged in recent years. This review focuses on the role of p53 in spermatogenesis and male infertility and analyses the possible underlying mechanism involved. All these conclusions may provide a new perspective on drug intervention targeting p53 for male infertility treatment.

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.

Mouse Pxt1 expression is regulated by Mir6996 miRNA

Mouse Pxt1 gene is expressed exclusively in male germ cells and encodes for a small, cell death inducing protein. However, upon PXT1 interaction with BAG6, cell death is prevented. In transiently transfected cell lines the PXT1 expression triggered massive cell death, thus we ask the question whether the interaction of PXT1 and BAG6 is the only mechanism preventing normal, developing male germ cells from being killed by PXT1. The Pxt1 gene contains a long 3'UTR thus we have hypothesized that Pxt1 can be regulated by miRNA. We have applied Pxt1 knockout and used Pxt1 transgenic mice that overexpressed this gene to shed more light on Pxt1 regulation. Using the ELISA assay we have demonstrated that PXT1 protein is expressed in adult mouse testis, though at low abundance. The application of dual-Glo luciferase assay and the 3'UTR cloned into p-MIR-Glo plasmid showed that Pxt1 is regulated by miRNA. Combining the use of mirDB and the site-directed mutagenesis further demonstrated that Pxt1 translation is suppressed by Mir6996-3p. Considering previous reports and our current results we propose a model for Pxt1 regulation in the mouse male germ cells.

Functions and mechanism of noncoding RNA in regulation and differentiation of male mammalian reproduction

Noncoding RNAs (ncRNAs) are active regulators of a wide range of biological and physiological processes, including the majority of mammalian reproductive events. Knowledge of the biological activities of ncRNAs in the context of mammalian reproduction will allow for a more comprehensive and comparative understanding of male sterility and fertility. In this review, we describe recent advances in ncRNA-mediated control of mammalian reproduction and emphasize the importance of ncRNAs in several aspects of mammalian reproduction, such as germ cell biogenesis and reproductive organ activity. Furthermore, we focus on gene expression regulatory feedback loops including hormones and ncRNA expression to better understand germ cell commitment and reproductive organ function. Finally, this study shows the role of ncRNAs in male reproductive failure and provides suggestions for further research.

A Comprehensive Sequencing Analysis of Testis-Born miRNAs in Immature and Mature Indigenous Wandong Cattle (Bos taurus)

Micro RNAs (miRNAs) have been recognized as important regulators that are indispensable for testicular development and spermatogenesis. miRNAs are endogenous transcriptomic elements and mainly regulate the gene expression at post-transcriptional levels; however, the key role of miRNA in bovine testicular growth is not clearly understood. Thus, supposing to unveil the transcriptomics expression changes in the developmental processes of bovine testes, we selected three immature calves and three sexually mature bulls of the local Wandong breed for testicular-tissue sample collection. The cDNA libraries of experimental animals were established for RNA-sequencing analysis. We detected the miRNA expression in testes by using high-throughput sequencing technology, and bioinformatics analysis followed. The differentially expressed (DE) data showed that 151 miRNAs linked genes were significantly DE between immature and mature bull testes. Further, in detail, 64 were significantly up-regulated and 87 were down-regulated in the immature vs. mature testes (p-value < 0.05). Pathway analyses for miRNA-linked genes were performed and identified JAG2, BCL6, CFAP157, PHC2, TYRO3, SEPTIN6, and BSP3; these genes were involved in biological pathways such as TNF signaling, T cell receptor, PI3KAkt signaling, and functions affecting testes development and spermatogenesis. The DE miRNAs including MIR425, MIR98, MIR34C, MIR184, MIR18A, MIR136, MIR15A, MIR1388 and MIR210 were associated with cattle-bull sexual maturation and sperm production. RT-qPCR validation analysis showed a consistent correlation to the sequencing data findings. The current study provides a good framework for understanding the mechanism of miRNAs in the development of testes and spermatogenesis.

Feline microRNAome in ovary and testis: Exploration of in-silico miRNA-mRNA networks involved in gonadal function and cellular stress response

The aim of the study was to perform the first in-depth analysis of miRNAs in ovarian and testicular tissues of the domestic cat, a critical biomedical model. Specifically, potential miRNA involvement was explored in gonadal function, testis development, and cellular stress response to preservation protocols. We performed miRNA-sequencing on 20 ovarian and 20 testicular samples from 15 cats, including different ages and tissue treatments. Using fresh tissues (n = 15), we confirmed gonadal expression of 183 miRNA precursors and discovered additional 52 novel feline candidate precursors. We integrated the mRNA data from our previous study on the same age and treatment groups to create in-silico miRNA-mRNA networks and their functional enrichment, which allows comprehensive exploration into possible miRNA functions in cat gonads. Clusters of miRNAs united by shared differentially expressed mRNA targets are potentially involved in testicular development and spermatogenesis. MicroRNAs could play a significant role in ovarian tissue response to stress from microwave-assisted dehydration, with smaller roles in cellular response to vitrification in both ovary and testis. This new list of miRNAs with potential function in cat gonads is a major step towards understanding the gonadal biology, as well as optimizing fertility preservation protocols.

Targeting Autophagy for Developing New Therapeutic Strategy in Intervertebral Disc Degeneration

Intervertebral disc degeneration (IVDD) is a prevalent cause of low back pain. IVDD is characterized by abnormal expression of extracellular matrix components such as collagen and aggrecan. In addition, it results in dysfunctional growth, senescence, and death of intervertebral cells. The biological pathways involved in the development and progression of IVDD are not fully understood. Therefore, a better understanding of the molecular mechanisms underlying IVDD could aid in the development of strategies for prevention and treatment. Autophagy is a cellular process that removes damaged proteins and dysfunctional organelles, and its dysfunction is linked to a variety of diseases, including IVDD and osteoarthritis. In this review, we describe recent research findings on the role of autophagy in IVDD pathogenesis and highlight autophagy-targeting molecules which can be exploited to treat IVDD. Many studies exhibit that autophagy protects against and postpones disc degeneration. Further research is needed to determine whether autophagy is required for cell integrity in intervertebral discs and to establish autophagy as a viable therapeutic target for IVDD.

Exogenous gonadotropin-releasing hormone counteracts the adverse effect of scrotal insulation on testicular functions in bucks

This study determined the effects of scrotal insulation on testicular functions in bucks and evaluated the impact of exogenous gonadotropin-releasing hormone (GnRH) administration before scrotal insulation on sperm production and testicular vascular dynamics. Twelve bucks were randomly divided into three groups: scrotal-insulated animals without GnRH treatment (INS), scrotal-insulated animals treated previously with GnRH (GnRH + INS), and animals without insulation as controls (CON). Doppler ultrasonography was used to evaluate testicular vascular changes, and semen samples were collected to assess seminal parameters. Testicular samples were collected from slaughtered bucks at the end of the experiment for histological investigations and immunohistochemical analysis for caspase 3 (apoptotic marker), and a vascular endothelial growth factor (VEGF; hypoxic marker) evaluation. Sperm motility drastically decreased (33%) in the INS group on day 8 compared with those in the GnRH + INS and CON groups (58% and 85%, respectively). Testicular blood flow significantly decreased for 3 and 2 weeks in the INS and GnRH + INS groups, respectively. The pulsatility index (PI) reached pretreatment values at 5 and 4 weeks after insulation in the INS and GnRH + INS groups, respectively. The resistance index (RI) values increased in both insulated groups for the first 2 weeks and decreased to control values 4 weeks after insulation. However, the maximum velocity (VP) started to increase reaching pretreatment values by the 5th and 3rd weeks after insulation in the INS and GnRH + INS groups, respectively. Histological investigations showed a marked reduction in lipid inclusions in Sertoli cells in the GnRH + INS group compared with those in the INS group. The distributions of both caspase 3 and VEGF decreased in the GnRH + INS group compared with those in the INS group. This study showed that the administration of a single dose of GnRH delayed the negative effects of scrotal insulation on different seminal traits and revealed the pivotal role of GnRH in compensating testicular insulation in bucks.

miR-122-5p targets GREM2 to protect against glucocorticoid-induced endothelial damage through the BMP signaling pathway

Glucocorticoid (GC)-induced osteonecrosis of the femoral head (ONFH) accounts for a big portion of non-traumatic ONFH; nevertheless, the pathogenesis has not yet been fully understood. GC-induced endothelial dysfunction might be a major contributor to ONFH progression. The Gene Expression Omnibus (GEO) dataset was analyzed to identify deregulated miRNAs in ONFH; among deregulated miRNAs, the physiological functions of miR-122-5p on ONFH and endothelial dysfunction remain unclear. In the present study, miR-122-5p showed to be under-expressed within GC-induced ONFH femoral head tissues and GC-stimulated bone microvascular endothelial cells (BMECs). In human umbilical vein endothelial cells (HUVECs) and BMECs, GC stimulation significantly repressed cell viability, promoted cell apoptosis and increased the mRNA expression of proinflammatory cytokines, such as TNF-α, IL-1β, and IFN-γ. After overexpressing miR-122-5p, GC-induced endothelial injuries were attenuated, as manifested by rescued cell viability, cell migration, and tube formation capacity. Regarding the BMP signaling, GC decreased the protein levels of BMP-2/6/7 and SMAD-1/5/8, whereas miR-122-5p overexpression significantly attenuated the inhibitory effects of GC on these proteins. Online tool and experimental analyses revealed the direct binding between miR-122-5p and GREM2, a specific antagonist of BMP-2. In contrast to miR-122-5p overexpression, GREM2 overexpression aggravated GC-induced endothelial injury; GREM2 silencing partially eliminated the effects of miR-122-5p inhibition on GC-stimulated HUVECs and BMECs. Finally, GREM2 silencing reversed the suppressive effects of GC on BMP-2/6/7 and SMAD-1/5/8, and attenuated the effects of miR-122-5p inhibition on these proteins upon GC stimulation. Conclusively, the present study demonstrates a miR-122-5p/GREM2 axis modulating the GC-induced endothelial damage via the BMP/SMAD signaling. Considering the critical role of endothelial function in ONFH pathogenesis, the in vivo role and clinical application of the miR-122-5p/GREM2 axis is worthy of further investigation.

Roles of Noncoding RNA in Reproduction

The World Health Organization predicts that infertility will be the third major health threat after cancer and cardiovascular disease, and will become a hot topic in medical research. Studies have shown that epigenetic changes are an important component of gametogenesis and related reproductive diseases. Epigenetic regulation of noncoding RNA (ncRNA) is appropriate and is a research hotspot in the biomedical field; these include long noncoding RNA (lncRNA), microRNA (miRNA), and PIWI-interacting RNA (piRNA). As vital members of the intracellular gene regulatory network, they affect various life activities of cells. LncRNA functions as a molecular bait, molecular signal and molecular scaffold in the body through molecular guidance. miRNAs are critical regulators of gene expression; they mainly control the stability or translation of their target mRNA after transcription. piRNA functions mainly through silencing genomic transposable elements and the post-transcriptional regulation of mRNAs in animal germ cells. Current studies have shown that these ncRNAs also play significant roles in the reproductive system and are involved in the regulation of essential cellular events in spermatogenesis and follicular development. The abnormal expression of ncRNA is closely linked to testicular germ cell tumors, poly cystic ovary syndrome and other diseases. This paper briefly presents the research on the reproductive process and reproductive diseases involving ncRNAs.

MicroRNAs: Potential biomarkers for reproduction, diagnosis, prognosis, and therapeutic in domestic animals

MicroRNA (miRNAs) are small non-coding RNA molecules involved in a wide range of biological processes through the post-transcriptional regulation of gene expression. Most studies evaluated microRNA expression in human, and despite fewer studies in veterinary medicine, this topic is one of the most exciting areas of modern veterinary medicine. miRNAs showed to be part of the pathogenesis of diseases and reproduction physiology in animals, making them biomarkers candidates. This review provides an overview of the current knowledge regarding miRNAs' role in reproduction and animal diseases, diagnostic and therapy.

Sperm miR-34c-5p Transcript Content and Its Association with Sperm Parameters in Unexplained Infertile Men

MicroRNAs (miRNAs) play an essential role in regulatory functions during gametogenesis. There is evidence that dysregulation of miR-34c-5p is implicated in the pathogenesis of male infertility. Whether miR-34c-5p expression could represent the semen quality and be useful in prediction of the fertilizing ability in normozoospermic men was examined in this study. Normozoospermic infertile patients (n = 15) and fertile men (n = 15) were recruited from the Infertility Clinic of Ahvaz, Iran. Sperm contents of miR-34c-5p transcript in were assessed using real-time polymerase chain reaction. No significant differences were seen in semen characteristics between patients and fertile men. Infertile patients showed significant (p = 0.019) lower contents of sperm miR-34c-5p than fertile controls. Men with lower transcript contents of miR-34c-5p exhibit lower sperm motility and normal morphology. Sperm miR-34c-5p transcript with a relatively good diagnostic power discriminated unexplained infertile men (AUC = 0.751, 95% CI: 0.568-0.934; p = 0.019). Our findings show that sperm contents of miR-34c-5p transcript could reflect the quality of spermatozoa in etiology of unexplained male infertility and be helpful in predicting a successful pregnancy.

MiRNA-34c Regulates Bovine Sertoli Cell Proliferation, Gene Expression, and Apoptosis by Targeting the AXL Gene

Simple Summary

Fertility is one of the essential reproduction traits of bulls, and accurate prediction of fertility potential using a semen sample from a donor bull for artificial insemination is crucial to achieve consistently high reproductive efficiency. Somatic cells, such as Sertoli cells and Leydig cells, are important in testis formation and provide a nurturing and regulatory environment for spermatogenesis. Furthermore, it was suggested that non-coding RNAs, such as microRNAs, long non-coding RNAs, circular RNAs, and Piwi-interacting RNA, function as important regulators of gene expression at post-transcriptional level in spermatogenesis. In this study, microRNA-34c was verified to specifically regulate the AXL gene by targeting a sequence in the 3’ UTR; miRNA-34c can also influence the proliferation, apoptosis, and relative abundance of the transcript of male-reproduction-related genes. Therefore, microRNA-34c can be considered an essential regulator in the process of bull spermatogenesis. These results identify a key microRNA and functional genes in the process of cattle male reproduction, providing useful information for future marker-assisted selection of bulls with excellent sperm quality.

Abstract

MicroRNAs (miRNAs) play significant roles in mammalian spermatogenesis. Sertoli cells can provide a stable microenvironment and nutritional factors for germ cells, thus playing a vital role in spermatogenesis. However, few studies elucidate the regulation of bovine testicular Sertoli cells by miRNAs. Here, we have reported that miRNA-34c (miR-34c) regulates proliferation, apoptosis, and relative transcripts abundance gene in bovine Sertoli cells. In bovine Sertoli cells, overexpression of miR-34c inhibited proliferation and relative abundance of gene transcripts while promoting apoptosis of Sertoli cells, and the effects were the opposite when miR-34c was knocked down. Receptor tyrosine kinase (AXL) was identified as a direct target gene of miR-34c in Sertoli cells, validated by analysis of the relative abundance of AXL transcript and dual-luciferase reporter assay. The relative abundance of the transcript of genes related to male reproduction in Sertoli cells was changed after the AXL gene was overexpressed, as demonstrated by the RT2 Profiler PCR Array results. In summary, miR-34c specifically regulated the AXL gene by targeting a sequence in the 3′-UTR, which could influence proliferation, apoptosis, and relative abundance of the transcript of male reproduction-related genes. Therefore, miR-34c could be considered an essential regulator in the process of bull spermatogenesis.

Differentially Expressed MiRNAs of Goat Submandibular Glands Among Three Developmental Stages Are Involved in Immune Functions

Submandibular glands (SMGs) are one of the primary components of salivary glands in goats. The proteins and biologically active substances secreted by the SMGs change with growth and development. Our previous studies showed that most of the differentially expressed genes in the SMGs of goats at different developmental stages are involved in immune-related signaling pathways, but the miRNA expression patterns in the same tissues are unknown. The aim of this study was to reveal the expression profile of miRNAs at three different developmental stages, detect differentially expressed miRNAs (DE miRNAs) and predict disease-related DE miRNAs. SMG tissue samples were collected from groups of 1-month-old kids, 12-month-old maiden goats and 24-month-old adult goats (three samples from each group), and high-throughout transcriptome sequencing was conducted. A total of 178, 241 and 7 DE miRNAs were discovered between 1-month-old kids and 12-month-old maiden goats, between 1-month-old kids and 24-month-old adult goats, and between 12-month-old maiden goats and 24-month-old adult goats, respectively. Among these DE miRNAs, 88 DE miRNAs with medium or high expression levels (TPM ≥50) were classified into five expression pattern clusters. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses indicated that some of the predicted target genes of the DE miRNAs in the five clusters were enriched in disease-related GO terms and pathways. MiRNA target genes in significant pathways were significantly enriched in Hepatitis B (FDR = 9.03E-10) and Pathways in cancer (FDR = 4.2E-10). Further analysis was performed with a PPI network, and 10 miRNAs were predicted to play an important role in the occurrence and prevention of diseases during the growth and development of goats.

Mir-34c affects the proliferation and pluripotency of porcine induced pluripotent stem cell (piPSC)-like cells by targeting c-Myc

MicroRNAs are important regulators in stem cells, which involve in gene regulation, including cell proliferation, differentiation and apoptosis. As an important one, miR-34c participates in various processes by targeting protein-coding genes. It is generally considered as a tumor suppressor and cell adhesion inhibitor. However, whether miR-34c has effects on pluripotent stem cells is not clear. Here, by mir-34c mimics transfection, the function of miR-34c on porcine induced pluripotent stem cell (piPSC)-like cells was investigated. Bioinformatics analyses showed that c-Myc is miR-34c's candidate target, which was confirmed by dual Luciferase assay. The knockout of miR-34c indicated that mir-34c affects the proliferation and pluripotency of piPSC-like cells by targeting c-Myc. Our study explored the regulatory mechanism of miR-34c on piPSC-like cells, providing a reference for the establishment of true porcine PSCs.

Novel biomarkers for the diagnosis and prognosis of gallbladder cancer

Gallbladder cancer (GBC) is the most common form of biliary tract malignancy with a dismal prognosis. A poor outcome in patients with GBC is related to the aggressive nature of the tumor, delayed diagnosis, and a lack of reliable biomarkers and effective treatment. Therefore, early diagnosis and accurate disease assessment are crucial to prolonging the patient survival. Identification of novel prognostic and diagnostic biomarkers may help improve the early diagnostic rate and develop specific targeted treatments for patients with GBC. We herein review the novel biomarkers that may be associated with the diagnosis and prognosis in GBC and their potential clinical significance in the management of GBC.

The epigenetic alterations of human sperm cells caused by heroin use disorder

The molecular mechanisms of drug use on sexual health are largely unknown. We investigated, the relationship between heroin use disorder and epigenetic factors influencing histone acetylation in sperm cells. The volunteers included twenty-four 20- to 50-year-old men with a normal spermogram who did not consume any drugs and twenty-four age- to BMI-matched men who consume only the drug heroin for more than last four months. HDAC1 and HDAC11 mRNA expression levels in spermatozoa and miR-34c-5p and miR-125b-5p expression levels in seminal plasma were measured. The heroin-user group showed significantly increased white blood cell counts and decreased sperm motility and survival rates (8.61 ± 1.73, 21.50 ± 3.11, 69.90 ± 4.69 respectively) as compared to the control group (1.49 ± 0.32, 38.82 ± 3.05, 87.50 ± 0.99 respectively) (p ≤ .001). An increase in DNA fragmentation index (DFI) (heroin-user group: 41.93 ± 6.59% and control group: 10.14 ± 1.43%, p = .003), a change in frequency of HDAC1 (heroin-user group: 1.69 ± 0.55 and control group: 0.45 ± 0.14, p = .045) and HDAC11 (heroin-user group: 0.29 ± 0.13 and control group: 2.36 ± 0.76, p = .019) in spermatozoa and a significant decrease in seminal miR-125b-5p abundance (heroin-user group: 0.37 ± 0.11 and control group: 1.59 ± 0.47, p = .028) were reported in heroin consumers. Heroin use can lead to male infertility by causing leukocytospermia, asthenozoospermia, DFI elevation in sperm cells and alterations in seminal RNA profile.

[Expression and significance of microRNA-125b in tongue squamous cell carcinoma]

OBJECTIVE

The expression of microRNA-125b in tongue squamous cell carcinoma (TSCC) was detected and analyzed for its relationship with the clinicopathological features of TSCC.

METHODS

Real time fluorescence-quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of microRNA-125b in 35 TSCC tissues and adjacent normal tissues from 35 TSCC cases. The relationship between the expression of microRNA-125b in TSCC tissues and the clinicopathological features of patients with TSCC was analyzed. In situ hybridization (ISH) was used to detect the expression level of microRNA-125b gene in the TSCC tissues and adjacent normal tissues.

RESULTS

RT-qPCR results showed that the relative expression levels of microRNA-125b in the TSCC issues was 2.32±0.69, and that of normal tissues was 0.87±0.32. The statistical results showed that the expression level of microRNA-125b was significantly higher in the TSCC tissues than in the normal tissues (P<0.001). The expression level of microRNA-125b in the TSCC tissues was not significantly correlated with age, gender, pathological grade, and lymph node metastasis but was positively correlated with TNM stage. Patients with high TNM stage had high microRNA-125b expression levels (P<0.05). The ISH results showed that the expression levels of microRNA-125b in the TSCC tissues were 0.010±0.003, and that of normal tissues was 0.004±0.001. The expression levels of microRNA-125b in the 35 TSCC tissues were significantly higher than those in the normal tissues (P<0.05).

CONCLUSIONS

MicroRNA-125b is highly expressed in TSCC and associated with TNM stage, suggesting that high microRNA-125b expression may be involved in the development of TSCC.

Phosphoribosyl-pyrophosphate synthetase 2 (PRPS2) depletion regulates spermatogenic cell apoptosis and is correlated with hypospermatogenesis

Phosphoribosyl-pyrophosphate synthetase 2 (PRPS2) is a rate-limiting enzyme and plays an important role in purine and pyrimidine nucleotide synthesis. Recent studies report that PRPS2 is involved in male infertility. However, the role of PRPS2 in hypospermatogenesis is unknown. In this study, the relationship of PRPS2 with hypospermatogenesis and spermatogenic cell apoptosis was investigated. The results showed that PRPS2 depletion increased the number of apoptotic spermatogenic cells in vitro. PRPS2 was downregulated in a mouse model of hypospermatogenesis. When PRPS2 expression was knocked down in mouse testes, hypospermatogenesis and accelerated apoptosis of spermatogenic cells were noted. E2F transcription factor 1 (E2F1) was confirmed as the target gene of PRPS2 and played a key role in cell apoptosis by regulating the P53/Bcl-xl/Bcl-2/Caspase 6/Caspase 9 apoptosis pathway. Therefore, these data indicate that PRPS2 depletion contributes to the apoptosis of spermatogenic cells and is associated with hypospermatogenesis, which may be helpful for the diagnosis of male infertility.

Sperm miR-15a and miR-29b are associated with bull fertility

MicroRNAs modulate male fertility by regulating gene expression. In this study, dynamics of sperm miR-15a, miR-29b and miR-34a from high fertility (HF) and low fertility (LF) bulls using RT-qPCR were evaluated. Bioinformatic tools were employed to ascertain genes of interest of the sperm miRNAs. The expression levels of p53, BCL2, BAX and DNMT1 in bull spermatozoa were determined by immunoblotting. MicroRNA levels of miR-15a and miR-29 were higher in LF sires when compared with those present in HF bulls. Expression levels of miR-34a did not differ between the two groups. We found an inverse correlation between miR-15a and bull fertility. MiR29-b was also negatively associated with fertility scores. BCL2 and DNMT1 were higher in HF bulls while BAX was higher in the LF group. Our data showed a positive correlation between BCL2 and bull fertility. In addition, DNMT1 was positively associated with bull fertility. Furthermore, levels of BAX were negatively linked with bull fertility scores. Identification of miRNAs found in the spermatozoa of sires with different in vivo fertility helps understand the alterations in the fertilising capacity from cattle and other mammals. These potential biomarkers can be used in reproductive biotechnology as fertility markers to assess semen quality and predict male fertility.

Downregulation of microRNA-3934-5p induces apoptosis and inhibits the proliferation of neuroblastoma cells by targeting TP53INP1

Neuroblastoma is the most common pediatric extracranial solid tumour in the world. miRNAs are a group of endogenous small non-coding RNAs that act on target genes to serve critical roles in many biological processes. Presently, the expression and role of miR-3934-5p in neuroblastoma remains unclear. Therefore, the aim of the present study was to investigate the expression of miR-3934-5p in neuroblastoma tissues and cell lines and to assess the role of miR-3934-5p in neuroblastoma. In the current study, the results revealed that miR-3934-5p was significantly upregulated in neuroblastoma tissues and cell lines. The data also identified TP53INP1 as a direct target gene of miR-3934-5p, which was negatively regulated by miR-3934-5p. The present study further demonstrated that TP53INP1 was downregulated in both neuroblastoma tissues and cell lines. Furthermore, the results of the current study indicate that miR-3934-5p downregulation may induce apoptosis and inhibit neuroblastoma cell viability. However, these effects were reversed via TP53INP1-siRNA. Data from the current study indicates that the miR-3934-5p/TP53INP1 axis may be a novel therapeutic target for neuroblastoma treatment.

miR-34a Inhibits Cell Proliferation by Targeting SATB2 in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common type of malignancy of the liver and has been reported as the third most frequent cause of cancer associated death worldwide. Accumulating evidence showed that the expression of miR-34a was abnormal in HCC patients; however, the role of miR-34a in HCC is not clear. In this study, we have observed low expression of the miR-34a in both HCC tissues and hepatoma cell line as compared to normal control. Further to investigate the role of miR-34a in HCC development, HepG2 cells were transfected with miR-34a mimic. Following transfection, miR-34a expression was significantly increased, which further repressed proliferation of HepG2 cells. Bioinformatics, Luciferase Reporter, RT-qPCR, and western blotting assays indicated that special AT-rich sequence-binding protein-2 (SATB2) is a direct target of miR-34a in HCC cells. There was a negative correlation between the expression levels of SATB2 and miR-34a. Investigation into the molecular mechanism indicated that miR-34a regulated cell proliferation through inhibiting SATB2. Therefore, the results of the present study may improve understanding regarding the role of miR-34a in regulating cell proliferation and contribute to the development of novel therapy of HCC.

miRNA-31-5p Mediates the Proliferation and Apoptosis of Human Spermatogonial Stem Cells via Targeting JAZF1 and Cyclin A2

Several lines of evidence highlight the important application of human spermatogonial stem cells (SSCs) in translational medicine. The fate decisions of SSCs are mainly mediated by genetic and epigenetic factors. We have recently demonstrated that PAK1 regulates the proliferation, DNA synthesis, and early apoptosis of human SSCs through the PDK1/KDR/ZNF367 and ERK1/2 and AKT pathway. However, the underlying epigenetic mechanism of PAK1 in human SSCs remains unknown. In this study, we found that the level of miRNA-31-5p was elevated by PAK1 knockdown. CCK-8, PCNA, and 5-ethynyl-2′-deoxyuridine (EDU) assays revealed that miRNA-31-5p mimics inhibited cell proliferation and DNA synthesis of human SSCs. Annexin V/propidium iodide (PI) staining and flow cytometry showed that miRNA-31-5p increased the early and late apoptosis of human SSCs. Furthermore, JAZF1 was predicted and verified as a target of miRNA-31-5p, and the three-dimensional (3D) structure model of JAZF1 protein was illustrated. JAZF1 silencing led to a reduction of cell proliferation and DNA synthesis as well as an enhancement of the early and late apoptosis of human SSCs. Finally, miRNA-31-5p mimics decreased the level of cyclin A2 rather than cyclin D1 or cyclin E1, and JAZF1 knockdown led to the reduction of cyclin A2 in human SSCs. Collectively, miRNA-31-5p regulates the proliferation, DNA synthesis, and apoptosis of human SSCs by the PAK1-JAZF1-cyclin A2 pathway. This study thus offers a novel insight into the molecular mechanisms underlying the fate determinations of human SSCs and might provide novel targets for molecular therapy of male infertility.

miR-34 regulates reproduction by inhibiting the expression of MIH, CHH, EcR, and FAMeT genes in mud crab Scylla paramamosain

Mud crab Scylla paramamosain is a commercially important species widely cultured in China. It is well known that the eyestalk regulates reproductive activities in crustaceans. In our previous research, we found that the miR-34 expression level in male eyestalk was significantly higher than that in females. Thus, we assumed that it may play an important role in regulating reproduction. In this study, we used bioinformatic tools to identify the target genes of miR-34 in eyestalk. Six reproduction-related genes with an intact 3'-untranslated region (UTR), including molt-inhibiting hormone (MIH), crustacean hyperglycemic hormone (CHH), vitellogenesis-inhibiting hormone, red pigment concentrating hormone, ecdysone receptor (EcR), and farnesoic acid methyltransferase (FAMeT) were identified. When the 3'-UTR plasmid vectors of the six genes were cotransfected with miR-34 mimics into 293FT cells, respectively, the luciferase activities of four genes (MIH, CHH, EcR, and FAMeT) were significantly decreased compared with that in the control group; on the contrary, when the six plasmid vectors were cotransfected with the miR-34 inhibitor respectively, the luciferase activities of four genes (MIH, CHH, EcR, and FAMeT) were significantly higher than that in the control group. When agomiR-34 and antagomiR-34 were injected into the eyestalk respectively in vivo, the expression levels of the MIH, CHH, EcR, and FAMeT genes were detected by a quantitative real-time polymerase chain reaction. The results showed that agomiR-34 suppressed the expression of the four genes, whereas antagomiR-34 enhanced their expression. These experimental results confirmed our hypothesis that miR-34 may indirectly regulate reproduction via binding to the 3'-UTRs of MIH, CHH, EcR, and FAMeT genes and suppressing their expression.

Serum miR-542-3p as a prognostic biomarker in osteosarcoma

OBJECTIVE

Emerging evidence has suggested that circulating microRNAs (miRNAs) in body fluids have novel diagnostic and prognostic significance for patients with malignant diseases. The lack of useful biomarkers is a crucial problem of osteosarcoma (OS); Previous study has reported that miR-542-3p was significantly upregulated in osteosarcoma tissues and miR-542-3p may be as an oncogene in osteosarcoma pathogenesis. In our study, we investigated the circulating miR-542-3p and its clinical relevance in osteosarcoma.

METHODS

Serum MiR-542-3p levels were determined by quantitative real-time PCR assays (qRT-PCR) in 76 patients with OS and 76 healthy volunteers. Patient survival analyses were performed by Kaplan-Meier analyses and Cox regression models. All statistical tests were two-sided.

RESULTS

It was observed that the serum levels of miR-542-3p was significantly higher in patients with OS compared with the control groups (P< 0.01). High serum of miR-542-3p was significantly associated with advanced tumor stage and shorter survival (P< 0.01). ROC curve analysis calculated the ideal miR-542-3p cut-off value of 0.84 in prediction of OS, with a sensitivity of 53.8%, specificity of 93.6%, positive predictive value of 87.3% and negative predictive value of 63.7%.

CONCLUSIONS

The results showed that serum miR-542-3p levels could serve as a non-invasive blood biomarker for tumor monitoring and prognostic prediction in osteosarcoma patients.

MiR-302 enhances the viability and stemness of male germline stem cells

MicroRNAs were reported to be able to regulate mGSCs' self-renewal through post-transcriptional inhibition of gene expression. miR-302 worked as one important microRNA family existed mainly in human ESCs, and its role in mGSCs has not been reported yet. To elucidate the role of miR-302 in dairy goat mGSCs, the expression profile of miR-302 was explored through qPCR and FISH. Furthermore, to detect the function of miR-302, the expression vector containing miR-302 was transfected into mGSCs, and then, the cell cycle, the cell apoptosis and the genes associated with mGSCs' self-renewal and differentiation were examined. The results showed that miR-302 expressed in testis moderately and located on the basement of seminiferous tubes which shared the same location as mGSCs. Transfection of the vector containing miR-302 fragment into the immortalized mGSCs obviously enhanced the cell proliferation ability and the attachment ability, also, promoted the expression level of CD49f and OCT4. Also, miR-302 reduced the cell apoptosis and downregulated the expression of P21. miR-302 sustained mGSCs' proliferation in vitro.

MicroRNA-381 reduces inflammation and infiltration of macrophages in polymyositis via downregulating HMGB1

The downregulation of microRNA (miR)-381 has been detected in various diseases. The present study aimed to investigate the effects, and underlying mechanisms of miR-381 on inflammation and macrophage infiltration in polymyositis (PM). A mouse model of experimental autoimmune myositis (EAM) was generated in this study. Hematoxylin and eosin staining was conducted to detect the inflammation of muscle tissues. In addition, ELISA and immunohistochemistry were performed to determine the expression levels of associated factors, and reverse transcription-quantitative polymerase chain reaction and western blotting were used to detect the expression levels of related mRNAs and proteins. A luciferase activity assay was used to confirm the binding of miR-381 and high mobility group box 1 (HMGB1) 3' untranslated region. Transwell assays were also performed to assess the migratory ability of macrophages. The results demonstrated that serum creatine kinase (s-CK), HMGB1 and cluster of differentiation (CD)163 expression in patients with PM were increased compared within healthy controls. Conversely, the expression levels of miR-381 were downregulated in patients with PM. Furthermore, high HMGB1 expression was associated with poor survival rate in patients with PM. In the mouse studies, muscle inflammation and CD163 expression were decreased in the anti-IL-17 and anti-HMGB1 groups, compared with in the EAM model group. The expression levels of s-CK, HMGB1, IL-17 and intercellular adhesion molecule (ICAM)-1 were also downregulated in response to anti-IL-17 and anti-HMGB1. These findings indicated that HMGB1 was closely associated with inflammatory responses. In addition, the present study indicated that transfection of macrophages with miR-381 mimics reduced the migration of inflammatory macrophages, and the expression levels of HMGB1, IL-17 and ICAM-1. Conversely, miR-381 inhibition exerted the opposite effects. The effects of miR-381 inhibitors were reversed by HMGB1 small interfering RNA. In conclusion, miR-381 may reduce inflammation and the infiltration of macrophages; these effects were closely associated with the downregulation of HMGB1.

Identification and characterization of microRNAs in the pituitary of pubescent goats

BACKGROUND

Puberty is the period during a female mammal's life when it enters estrus and ovulates for the first time; this indicates that a mammal is capable of reproduction. The onset of puberty is a complex and tightly coordinated biological event; it has been reported that microRNAs (miRNAs) are involved in regulating the initiation of puberty.

METHODS

We performed miRNA sequencing on pituitary tissue from prepubescent and pubescent goats to investigate differences in miRNA expression during the onset of puberty in female goats. The target genes of these miRNAs were evaluated by GO enrichment and KEGG pathway analysis to identify critical pathways regulated by these miRNAs during puberty in goats. Finally, we selected four known miRNA and one novel miRNAs to evaluate expression patterns in two samples via qRT-PCR to validate the RNA-seq data.

RESULTS

In this study, 476 miRNAs were detected in goat pituitary tissue; 13 of these were specifically expressed in the pituitary of prepubescent goats, and 17 were unique to the pituitary of pubescent goats. Additionally, 73 novel miRNAs were predicted in these two libraries. 20 differentially expressed miRNAs were identified in this study. KEGG pathway enrichment analysis revealed that the differentially expressed miRNA target genes were enriched in pathways related to ovary development during puberty, including the GABAergic synapse, oxytocin signaling pathway, the cAMP signaling pathway, progesterone-mediated oocyte maturation. In this study, differential miRNA expression in the pituitary tissue of prepubescent and pubescent goats were identified and characterized.

CONCLUSION

These results provide important information regarding the potential regulation of the onset of goat puberty by miRNAs, and contribute to the elucidation of miRNA regulated processes during maturation and reproduction.

MiR-138-5p affects insulin resistance to regulate type 2 diabetes progression through inducing autophagy in HepG2 cells by regulating SIRT1

Insulin resistance (IR) is considered as a major factor of type 2 diabetes (T2D), which is seriously detrimental to human health. In our present study, we found that the expression of miR-138-5p was increased in the insulin-resistant HepG2 cells induced by TNF-α. Therefore, we hypothesized that miR-138-5p might play a regulatory role in the IR. To examine this hypothesis, HepG2 cells were transfected with miR-138-5p inhibitor. Silencing of miR-138-5p increased glucose uptake and glycogen synthesis of TNF-α-stimulated HepG2 cells and decreased glucose concentration in medium, suggesting that downregulation of miR-138-5p suppressed IR in HepG2 cells. Besides that, we found that sirtuin 1 (SIRT1) was the target gene of the miR-138-5p. Moreover, co-transfection with SIRT1-siRNA and miR-138-5p inhibitor suppressed glucose uptake and glycogen synthesis of HepG2 cells compared with miR-138-5p inhibitor-transfected group, indicating that downregulation of SIRT1 weakened the inhibitory effect of miR-138-5p inhibitor on IR. In addition, overexpressed SIRT1 increased Beclin1, LC3 II/I level, and the number of GFP-LC3 dots and decreased p62 level, whereas downregulation of SIRT1 had the opposite effects. Our results demonstrated that overexpressed SIRT1 activated autophagy in HepG2 cells. Moreover, we observed that 3-methyladenine (an inhibitor of autophagy) treatment decreased the high glucose uptake and glycogen synthesis of miR-138-5p inhibitor-transfected HepG2 cells, suggesting that the inhibition of autophagy abolished the inhibitory effect of miR-138-5p inhibitor on IR in HepG2 cells. Taken together, this study suggested that miR-138-5p contributed to the TNF-α-induced IR, possibly through inducing autophagy in HepG2 cells by regulating SIRT1. MiR-138-5p might be a potential and promising target for the treatment of IR.

An miR-200 Cluster on Chromosome 23 Regulates Sperm Motility in Zebrafish

Besides its well-documented roles in cell proliferation, apoptosis, and carcinogenesis, the function of the p53-microRNA axis has been recently revealed in the reproductive system. Recent studies indicated that miR-200 family members are dysregulated in nonobstructive azoospermia patients, whereas their functions remain poorly documented. The aim of this study was to investigate the function of the miR-200 family on zebrafish testis development and sperm activity. There was no substantial difference in testis morphology and histology between wild-type (WT) and knockout zebrafish with deletion of miR-200 cluster on chromosome 6 (chr6-miR-200-KO) or on chromosome 23 (chr23-miR-200-KO). Interestingly, compared with WT zebrafish, the chr6-miR-200-KO zebrafish had no difference on sperm motility, whereas chr23-miR-200-KO zebrafish showed significantly improved sperm motility. Consistently, ectopic expression of miR-429a, miR-200a, and miR-200b, which are located in the miR-200 cluster on chromosome 23, significantly reduced motility traits of sperm. Several sperm motility-related genes, such as amh, wt1a, and srd5a2b have been confirmed as direct targets of miR-200s on chr23. 17α-ethynylestradiol (EE2) exposure resulted in upregulated expression of p53 and miR-429a in testis and impairment of sperm motility. Strikingly, in p53 mutant zebrafish testis, the expression levels of miR-200s on chr23 were significantly reduced and accompanied by a stimulation of sperm motility. Moreover, the upregulation of miR-429a associated with EE2 treatment was abolished in testis with p53 mutation. And the impairment of sperm activity by EE2 treatment was also eliminated when p53 was mutated. Together, our results reveal that miR-200 cluster on chromosome 23 controls sperm motility in a p53-dependent manner.

Integrated analysis miRNA and mRNA profiling in patients with severe oligozoospermia reveals miR-34c-3p downregulates PLCXD3 expression

Our previous research suggested that an integrated analysis of microRNA (miRNA) and messenger RNA (mRNA) expression is helpful to explore miRNA-mRNA interactions and to uncover the molecular mechanisms of male infertility. In this study, microarrays were used to compare the differences in the miRNA and mRNA expression profiles in the testicular tissues of severe oligozoospermia (SO) patients with obstructive azoospermia (OA) controls with normal spermatogenesis. Four miRNAs (miR-1246, miR-375, miR-410, and miR-758) and six mRNAs (SLC1A3, PRKAR2B, HYDIN, WDR65, PRDX1, and ADATMS5) were selected to validate the microarray data using quantitative real-time PCR. Using statistical calculations and bioinformatics predictions, we identified 33 differentially expressed miRNAs and 1,239 differentially expressed mRNAs, among which one potential miRNA-target gene pair, miR-34c-3p and PLCXD3 (Phosphatidylinositol-Specific Phospholipase C, X Domain Containing 3), was identified. Immunohistochemical analysis indicated that PLCXD3 was located within the germ cells of the mouse and human testis. Moreover, we found that miR-34c-3p was able to decrease PLCXD3 expression in mouse (GC-1 and TM4) and human (NCM460) cell lines, presumably indicating the possibility that miR-34c-3p acts as an intracellular mediator in germinal lineage differentiation. Notably, we reported the expression of the PLCXD3 protein in a man with normal spermatogenesis and the lack of the PLCXD3 protein in a man with SO. Therefore, the identified miRNA and mRNA may represent a potentially novel molecular regulatory network and therapeutic targets for the study or treatment of SO, which might provide a better understanding of the molecular basis of spermatogenesis dysfunction.

MicroRNA-564 is downregulated in glioblastoma and inhibited proliferation and invasion of glioblastoma cells by targeting TGF-β1

Increasing evidence has indicated that aberrant expression of miRNAs has been shown to be strongly implicated in the initiation and progression of glioblastoma. Here, we identified a novel tumor suppressive miRNA, miR-564, and investigated its role and therapeutic effect for glioblastoma. We showed that miR-564 was down-regulated in human glioblastoma tissues and cell lines. Introduction of miR-564 dramatically inhibited cell growth and invasion in glioblastoma cells. Subsequent experiments revealed that Transforming growth factor-β1 (TGF-β1) was a direct and functional target of miR-564 in glioblastoma cells. Furthermore, overexpression of miR-564 decreased p-SMAD and SMAD4 expression, which are the downstream signaling molecules of TGF-β. Meanwhile, ectopic of miR-564 reduced the messenger RNA (mRNA) and protein expression of epidermal growth factor receptor (EGFR) and MMP9. Furthermore, the upregulation of miR-564 suppressed TGF-β-mediated U87 proliferation and migration. The expression of EGFR and MMP9 was upregulated in glioblastoma tissues compared to their normal tissues. The EGFR and MMP9 expression levels were inverse correlated with the expression of miR-564. miR-564 suppressed the growth of U87-engrafted tumors. These findings reveal that miR-564/TGF-β1 signaling that may be required for glioblastoma development and may consequently serve as a new therapeutic target for the treatment of glioblastoma.

Regulatory Functions of MicroRNAs in Male Reproductive Health: A New Approach to Understanding Male Infertility

MicroRNAs (miRNAs) are a novel class of small noncoding RNAs (ncRNAs) that play critical roles in regulation of gene expression, especially at posttranscriptional level. Over the past decade, the degree to which miRNAs are involved in male infertility has become clear. They are expressed in a cell- or phase-specific manner during spermatogenesis and play crucial role in male reproductive health. Therefore, dysregulation of miRNAs in testicular cells can be considered as a molecular basis for reproductive failure and male infertility. The abnormal expression pattern of miRNAs can be transmitted to the offspring via assisted reproductive techniques (ART) and results in the birth of children with a higher risk of infertility, congenital abnormalities, and morbidity. This review expounds on the miRNAs reported to play essential roles in somatic cells development, germ cells differentiation, steroidogenesis, normal spermatogenesis, sperm maturation, and male infertility, as well as emphasizes their importance as minimally invasive biomarkers of male infertility.

Overexpression of miR‑21 promotes neural stem cell proliferation and neural differentiation via the Wnt/β‑catenin signaling pathway in vitro

The primary aim of the present study was to examine the effects of microRNA‑21 (miR‑21) on the proliferation and differentiation of rat primary neural stem cells (NSCs) in vitro. miR‑21 was overexpressed in NSCs by transfection with a miR‑21 mimic. The effects of miR‑21 overexpression on NSC proliferation were revealed by Cell Counting kit 8 and 5‑ethynyl‑2'‑deoxyuridine incorporation assay, and miR‑21 overexpression was revealed to increase NSC proliferation. miR‑21 overexpression was confirmed using reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR). mRNA and protein expression levels of key molecules (β‑catenin, cyclin D1, p21 and miR‑21) in the Wnt/β‑catenin signaling pathway were studied by RT‑qPCR and western blot analysis. RT‑qPCR and western blot analyses revealed that miR‑21 overexpression increased β‑catenin and cyclin D1 expression, and decreased p21 expression. These results suggested that miR‑21‑induced increase in proliferation was mediated by activation of the Wnt/β‑catenin signaling pathway, since overexpression of miR‑21 increased β‑catenin and cyclin D1 expression and reduced p21 expression. Furthermore, inhibition of the Wnt/β‑catenin pathway with FH535 attenuated the influence of miR‑21 overexpression on NSC proliferation, indicating that the factors activated by miR‑21 overexpression were inhibited by FH535 treatment. Furthermore, overexpression of miR‑21 enhanced the differentiation of NSCs into neurons and inhibited their differentiation into astrocytes. The present study indicated that in primary rat NSCs, overexpression of miR‑21 may promote proliferation and differentiation into neurons via the Wnt/β‑catenin signaling pathway in vitro.

MicroRNAs: new players in cataract

Cataract is the most common cause of blindness worldwide. Multiple factors such as aging, eye injury, diabetes mellitus, ultraviolet exposure, drug use and other ocular diseases are etiologically linked to cataractogenesis. Due to a rapid increase in aging population, age-related cataract has become the leading cause of blindness. Therefore, it is urgent to understand the molecular mechanism underlying cataractogenesis. MicroRNAs (miRNAs) are a group of endogenous, small noncoding RNAs that regulate gene expression at the post-translational level through binding with the 3'-untranslated regions of target mRNAs. Studies have shown that miRNAs play important roles in multiple cellular functions, including apoptosis, cell proliferation, senescence and stress response. Deregulated expression of miRNAs is also linked to the pathogenesis of many diseases, including ocular diseases. In our review, we focus on miRNAs that are involved in cataract development and discuss their potential applications as novel diagnostic markers and therapeutic targets.

Long noncoding RNA MALAT1 promotes cell proliferation through suppressing miR-205 and promoting SMAD4 expression in osteosarcoma

Increasing evidences have indicated that long non-coding RNAs (lncRNAs) play an important role in multiply biological processes including cell development, differentiation, proliferation and invasion. The metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), is a highly conserved nuclear ncRNA and a key regulator of metastasis development in several cancers. However, its role in osteosarcoma progression is not well known. In this study, we sought to determine the clinical and bilogical role of MALAT1 in osteosarcoma progression. RT-qPCR analysis showed that MALAT1 expression was significantly increased in primary osteosarcoma tissues and cell lines. Kaplan-Meier analysis indicated that patients with high expression of MALAT1 was associated with poor overall survival compared with the low expressing patients. Furthermore, the gain and loss function assay showed that miR-205 was suppressed by MALAT1 in osteosarcoma and this interaction between miR-205 and MALAT1 has reciprocal effects. Cell viability assay showed that MALAT1 promoted MG-63 and SAOS-2 cell growth through suppressing miR-205. Subsequently, the downstream gene SMAD4 was identified as a direct functional target of miR-205, and miR-205 suppressed osteosarcoma cell growth through suppressing SMAD4. Finally, we demonstrated that MALAT1 promoted osteosarcoma progression via a miR-205-SMAD4 axis. In conclusion, we revealed that enhanced MALAT1 expression predicted unfavourable outcome in osteosarcoma and promoted cell proliferation through suppressing miR-205 and activating SMAD4 function. Thus, lncRNA MALAT1 may serve as a promising prognostic and therapeutic target for osteosarcoma patients.

The roles of microRNAs in regulation of mammalian spermatogenesis

Mammalian spermatogenesis contains three continuous and organized processes, by which spermatogonia undergo mitosis and differentiate to spermatocytes, follow on meiosis to form haploid spermatids and ultimately transform into spermatozoa. These processes require an accurately, spatially and temporally regulated gene expression patterns. The microRNAs are a novel class of post-transcriptional regulators. Cumulating evidences have demonstrated that microRNAs are expressed in a cell-specific or stage-specific manner during spermatogenesis. In this review, we focus on the roles of microRNAs in spermatogenesis. We highlight that N6-methyladenosine (m6A) is involved in the biogenesis of microRNAs and miRNA regulates the m6A modification on mRNA, and that specific miRNAs have been exploited as potential biomarkers for the male factor infertility, which will provide insightful understanding of microRNA roles in spermatogenesis.

Overexpression of miR-519d in lung adenocarcinoma inhibits cell proliferation and invasion via the association of eIF4H

Lung cancer is one of the deadliest types of cancer worldwide due to its high mortality rate. Adenocarcinoma constitutes 20%-30% of all lung cancers. In recent years, studies on the mechanisms of lung tumorigenesis and development have in part focused on the microRNAs for their crucial role in the progress of different cancers. As for our study, we demonstrated that miR-519d was differently downregulated and eIF4H was significantly overexpressed in lung adenocarcinoma via the detection of quantitative real-time polymerase chain reaction compared with the adjacent normal tissues. Furthermore, Cell Counting Kit-8 assay, colony formation assay, xenograft tumor experiment, Ki67 immunohistochemistry assay and transwell assay were performed to explain that the upregulated miR-519d could inhibit the proliferation and invasion of A549 and H1299 cells. To further advance our understanding of the mechanisms of miR-519d, we performed the bioinformatics analysis and the luciferase report assay. The results from these procedures revealed eIF4H to be one of the targets of miR-519d. Downregulated eIF4H was analogous to the overexpressed miR-519d obtained from miR-519d agomir and si-eIF4H transfection. In summary, it can be concluded that miR-519d targets eIF4H in lung adenocarcinoma to inhibit cell proliferation and invasion. This mechanism may offer new insights into the tumorigenesis and development of lung adenocarcinoma.

Upregulation of MiR-205 transcriptionally suppresses SMAD4 and PTEN and contributes to human ovarian cancer progression

MicroRNAs (miRNAs) function as critical regulators of gene expression and their deregulation is associated with the development and progression of various cancers. This study aimed to investigate the biological role and mechanism of miR-205 in ovarian cancer (OC). MiR-205 was upregulated in OC tissues and cells in comparison to the controls. Meanwhile, overexpression of miR-205 was significantly associated with poor overall survival of OC patients. Functional study indicated that ectopic expression of miR-205 significantly promoted cell proliferation, migration, invasion and chemoresistance of OC cells. SMAD4 and PTEN were identified as direct targets of miR-205 using luciferase reporter assays, real-time PCR (qRT-PCR), and western blot. Most interestingly, in vivo studies indicated that miR-205 markedly promoted the growth and metastasis of tumors and the expression of miR-205 was also found to be inversely correlated with that of SMAD4 and PTEN in nude mice. Overall, we suggest that miR-205 functions as an oncogenic miRNA by directly binding to SMAD4 and PTEN, providing a novel target for the molecular treatment of ovarian cancer.

Lin28a promotes self-renewal and proliferation of dairy goat spermatogonial stem cells (SSCs) through regulation of mTOR and PI3K/AKT

Lin28a is a conserved RNA-binding protein that plays an important role in development, pluripotency, stemness maintenance, proliferation and self-renewal. Early studies showed that Lin28a serves as a marker of spermatogonial stem cells (SSCs) and promotes the proliferation capacity of mouse SSCs. However, there is little information about Lin28a in livestock SSCs. In this study, we cloned Capra hircus Lin28a CDS and found that it is evolutionarily conserved. Lin28a is widely expressed in different tissues of Capra hircus, but is expressed at a high level in the testis. Lin28a is specifically located in the cytoplasm of Capra hircus spermatogonial stem cells and may also be a marker of dairy goat spermatogonial stem cells. Lin28a promoted proliferation and maintained the self-renewal of GmGSCs-I-SB in vivo and in vitro. Lin28a-overexpressing GmGSCs-I-SB showed an enhanced proliferation rate, which might be due to increased PCNA expression. Moreover, Lin28a maintained the self-renewal of GmGSCs-I-SB by up-regulating the expression of OCT4, SOX2, GFRA1, PLZF and ETV5. Furthermore, we found that Lin28a may activate the AKT, ERK, and mTOR signaling pathways to promote the proliferation and maintain the self-renewal of GmGSCs-I-SB.

MicroRNA-665 suppressed the invasion and metastasis of osteosarcoma by directly inhibiting RAB23

MicroRNAs (miRNAs) are small, short and noncoding RNAs that regulate gene expression posttranscriptionally. Increasing evidences have demonstrated that deregulated expression of miRNAs is found in osteosarcoma. In this study, we demonstrated that miR-665 was downregulated in osteosarcoma tissues compared to non-tumorous tissues. The overall survival (OS) of osteosarcoma patients with low miR-665 expression was lower than that of these patients with high miR-665 expression. Ectopic expression of miR-665 suppressed the osteosarcoma cell proliferation, EMT and invasion. We identified Rab23 as a direct target gene of miR-665. Rab23 was downregulated in osteosarcoma tissues and cell lines. The expression of miR-665 was inversely associated with the expression of Rab23 in the osteosarcoma tissues. These results suggested that miR-665 acted as a tumor suppressor gene in the development of osteosarcoma.

MiR-300 suppresses laryngeal squamous cell carcinoma proliferation and metastasis by targeting ROS1

Laryngeal squamous cell carcinoma (LSCC) is a common aggressive head and neck cancer with high mortality and incidence. MicroRNAs (miRNAs) are short, non-coding and endogenous RNAs that posttranscriptionally inhibit gene expression. In this study, we showed that miR-300 expression was downregulated in LSCC tissues compared with adjacent no-tumor tissues. MiR-300 overexpression inhibited Hep-2 cell proliferation, as well as the expression of ki-67 and PCNA. Moreover, overexpression of miR-300 repressed the cell invasion in Hep-2 cells. We identified c-ros oncogene 1 receptor tyrosine kinase (ROS1) as a direct target gene of miR-300 in Hep-2 cell. Furthermore, ROS1 expression was upregulated in LSCC tissues compared with adjacent no-tumor tissues. Interesting, there were an inverse correlation between ROS1 and miR-300 expression in the LSCC tissues. Overexpression of ROS1 increased the Hep-2 cells proliferation and invasion. Overexpression of ROS1 abrogated miR-300 induced cell growth and invasion inhibition. Therefore, our data suggested that miR-300 acted as a tumor suppressive gene in LSCC.

The role of microRNAs in intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) is the second most common primary hepatic malignancy with poor prognosis. Despite improvements in its diagnosis and therapy, the prognosis for ICC patients remains poor. An improved understanding of ICC pathogenesis and consequential identification of novel therapeutic targets would improve the prognosis of ICC patients. MicroRNAs (miRNAs) are a class of highly conserved, endogenous, small non‐coding RNA molecules of 18–23 nucleotides in length, which regulate gene expression through complementary base‐pairing with target messenger RNAs and subsequent gene silencing. Several studies have shown deregulated expression of miRNAs in ICC cell lines and tissues, in which these miRNAs play important roles in ICC apoptosis, cell proliferation, invasion, migration and metastasis. In this review, we illustrate the potential role of miRNA in the pathogenesis of ICC and explore the possibilities of using miRNAs as prognostic and diagnostic markers, as well as therapeutic targets in ICC.