FOXJ2 controls meiosis during spermatogenesis in male mice

Genome-wide variation study and inter-tissue communication analysis unveil regulatory mechanisms of egg-laying performance in chickens

Egg-laying performance is of great economic importance in poultry, but the underlying genetic mechanisms are still elusive. In this work, we conduct a multi-omics and multi-tissue integrative study in hens with distinct egg production, to detect the hub candidate genes and construct hub molecular networks contributing to egg-laying phenotypic differences. We identifiy three hub candidate genes as egg-laying facilitators: TFPI2, which promotes the GnRH secretion in hypothalamic neuron cells; CAMK2D, which promotes the FSHβ and LHβ secretion in pituitary cells; and OSTN, which promotes granulosa cell proliferation and the synthesis of sex steroid hormones. We reveal key endocrine factors involving egg production by inter-tissue crosstalk analysis, and demonstrate that both a hepatokine, APOA4, and an adipokine, ANGPTL2, could increase egg production by inter-tissue communication with hypothalamic-pituitary-ovarian axis. Together, These results reveal the molecular mechanisms of multi-tissue coordinative regulation of chicken egg-laying performance and provide key insights to avian reproductive regulation.

Comprehensive bioinformatics analysis and molecular validation of lncRNAs-mediated ceRNAs network in schizophrenia

AIMS

The present study aimed to investigate how Schizophrenia (SCZ)-specific long non-coding RNAs (lncRNAs) served as competing endogenous RNAs (ceRNAs) to modulate the biological functions and pathways involved in the pathogenesis of SCZ.

MAIN METHODS

Microarray dataset (GSE54913) was obtained from Gene Expression Omnibus (GEO) database. Differently expressed (DE) lncRNAs and mRNAs were identified by "limma" package. The binding miRNAs of lncRNAs and target mRNAs of shared miRNAs were predicted by miRcode, miRDB, miRTarbase and targetscan databases. Following the ceRNAs theory, interaction network was established and visualized with the cytoscape. Functional enrichment analysis uncovered the concentrated functions and signaling pathways that may be associated with SCZ progression. Protein-protein interaction (PPI) analysis was utilized to determine hub genes. Quantitative real-time PCR (qRT-PCR) and receiver operating characteristic curve (ROC) were performed to evaluate the expression and diagnostic value of ceRNAs members, respectively.

KEY FINDINGS

DElncRNAs and DEmRNAs were initially screened from GSE54913 to construct the SCZ-related ceRNAs network with 42 nodes and 53 edges. Functional enrichment analysis revealed that ceRNAs members appeared to be highly correlated with transcription factor activation, cell replication and tumor-related pathways. Once validated, a significant ceRNAs subnetwork was proposed as being implicated in the pathogenesis of SCZ. ROC analysis indicated that SCZ-related ceRNAs members may be sensitive diagnostic biomarkers for SCZ.

SIGNIFICANCE

The significant SCZ-related ceRNAs subnetworks (lncRNA-C2orf48A/hsa-miR-20b-5p,-17-5p/KIF23, FOXJ2) may represent promising predictive and diagnostic biomarkers and provide novel insights into the mechanism by which lncRNAs act as microRNA sponges and contribute to the pathogenesis of SCZ.

Germline FOXJ2 overexpression causes male infertility via aberrant autophagy activation by LAMP2A upregulation

Spermatogenesis is a complex biological process that produces haploid spermatozoa and requires precise regulation by many tissue-specific factors. In this study, we explored the role and mechanism of Fork head box J2 (FOXJ2, which is highly expressed in spermatocytes) in the regulation of spermatogenesis using a germline-specific conditional Foxj2 knock-in mouse model (Stra8-Cre; Foxj2 ^tg/tg mouse). Foxj2 overexpression in mouse testes led to spermatogenesis failure, which started at the initiation of meiosis, and resulted in male infertility. Lysosomes and autophagy-related genes were upregulated in Stra8-cre; Foxj2 ^tg/tg mouse testes and the number of autolysosomes in the spermatocytes in Stra8-cre; Foxj2 ^tg/tg mice was increased. Chromatin immunoprecipitation-PCR and Dual-luciferase reporter assays showed that Lamp2 (encoding lysosome-associated membrane protein-2) was a target of FOXJ2. Foxj2 overexpression increased the expression levels of Lamp2a and Hsc70 (70-kDa cytoplasmic heat shock protein) in the Stra8-cre; Foxj2 ^tg/tg mouse testes. Our results suggested that Foxj2 overexpression in the germ cells of mouse testes affects chaperone-mediated autophagy by upregulating LAMP2A, leading to spermatogenesis failure at the initiation of meiosis, thus resulting in male infertility. Our findings provide a new insight into the function of FOXJ2 in spermatogenesis and the significance of autophagy regulation in spermatogenesis.

A comprehensive study of arthropod and onychophoran Fox gene expression patterns

Fox genes represent an evolutionary old class of transcription factor encoding genes that evolved in the last common ancestor of fungi and animals. They represent key-components of multiple gene regulatory networks (GRNs) that are essential for embryonic development. Most of our knowledge about the function of Fox genes comes from vertebrate research, and for arthropods the only comprehensive gene expression analysis is that of the fly Drosophila melanogaster. For other arthropods, only selected Fox genes have been investigated. In this study, we provide the first comprehensive gene expression analysis of arthropod Fox genes including representative species of all main groups of arthropods, Pancrustacea, Myriapoda and Chelicerata. We also provide the first comprehensive analysis of Fox gene expression in an onychophoran species. Our data show that many of the Fox genes likely retained their function during panarthropod evolution highlighting their importance in development. Comparison with published data from other groups of animals shows that this high degree of evolutionary conservation often dates back beyond the last common ancestor of Panarthropoda.

Identification of Critical Genes and Signaling Pathways in Human Monocytes Following High-Intensity Exercise

BACKGROUND

Monocytes are critical components, not only for innate immunity, but also for the activation of the adaptive immune system. Many studies in animals and humans have demonstrated that monocytes may be closely associated with chronic inflammatory diseases and be proved to be pivotal in the association between high-intensity exercise and anti-inflammation response. However, the underlying molecular mechanisms driving this are barely understood. The present study aimed to screen for potential hub genes and candidate signaling pathways associated with the effects of high-intensity exercise on human monocytes through bioinformatics analysis.

MATERIALS AND METHODS

The GSE51835 gene expression dataset was downloaded from the Gene Expression Omnibus database. The dataset consists of 12 monocyte samples from two groups of pre-exercise and post-exercise individuals. Identifying differentially expressed genes (DEGs) with R software, and functional annotation and pathway analyses were then performed with related web databases. Subsequently, a protein-protein interaction (PPI) network which discovers key functional protein and a transcription factors-DEGs network which predicts upstream regulators were constructed.

RESULTS

A total of 146 differentially expressed genes were identified, including 95 upregulated and 51 downregulated genes. Gene Ontology analysis indicated that in the biological process functional group, these DEGs were mainly involved in cellular response to hydrogen peroxide, response to unfolded protein, negative regulation of cell proliferation, cellular response to laminar fluid shear stress, and positive regulation of protein metabolic process. The top five enrichment pathways in a Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were the FoxO signaling pathway, protein processing in the endoplasmic reticulum, influenza A, the ErbB signaling pathway, and the MAPK signaling pathway. TNF, DUSP1, ATF3, CXCR4, NR4A1, BHLHE40, CDKN1B, SOCS3, TNFAIP3, and MCL1 were the top 10 potential hub genes. The most important modules obtained in the PPI network were performed KEGG pathway analysis, which showed that these genes were mainly involved in the MAPK signaling pathway, the IL-17 signaling pathway, the TNF signaling pathway, osteoclast differentiation, and apoptosis. A transcription factor (TF) target network illustrated that FOXJ2 was a critical regulatory factor.

CONCLUSIONS

This study identified the essential genes and pathways associated with exercise and monocytes. Among these, four essential genes (TNF, DUSP1, CXCR4, and NR4A1) and the FoxO signaling pathway play vital roles in the immune function of monocytes. High-intensity exercise may improve the resistance of chronic inflammatory diseases by regulating the expression of these genes.

Histone Post-Translational Modifications and CircRNAs in Mouse and Human Spermatozoa: Potential Epigenetic Marks to Assess Human Sperm Quality

Spermatozoa (SPZ) are motile cells, characterized by a cargo of epigenetic information including histone post-translational modifications (histone PTMs) and non-coding RNAs. Specific histone PTMs are present in developing germ cells, with a key role in spermatogenic events such as self-renewal and commitment of spermatogonia (SPG), meiotic recombination, nuclear condensation in spermatids (SPT). Nuclear condensation is related to chromatin remodeling events and requires a massive histone-to-protamine exchange. After this event a small percentage of chromatin is condensed by histones and SPZ contain nucleoprotamines and a small fraction of nucleohistone chromatin carrying a landascape of histone PTMs. Circular RNAs (circRNAs), a new class of non-coding RNAs, characterized by a nonlinear back-spliced junction, able to play as microRNA (miRNA) sponges, protein scaffolds and translation templates, have been recently characterized in both human and mouse SPZ. Since their abundance in eukaryote tissues, it is challenging to deepen their biological function, especially in the field of reproduction. Here we review the critical role of histone PTMs in male germ cells and the profile of circRNAs in mouse and human SPZ. Furthermore, we discuss their suggested role as novel epigenetic biomarkers to assess sperm quality and improve artificial insemination procedure.

Genome-Wide Identification and Characterization of Fox Genes in the Honeybee, Apis cerana, and Comparative Analysis with Other Bee Fox Genes

The forkhead box (Fox) gene family, one of the most important families of transcription factors, participates in various biological processes. However, Fox genes in Hymenoptera are still poorly known. In this study, 14 Fox genes were identified in the genome of Apis cerana. In addition, 16 (Apis mellifera), 13 (Apis dorsata), 16 (Apis florea), 17 (Bombus terrestris), 16 (Bombus impatiens), and 18 (Megachile rotundata) Fox genes were identified in their genomes, respectively. Phylogenetic analyses suggest that FoxA is absent in the genome of A. dorsata genome. Similarly, FoxG is missing in the genomes A. cerana and A. dorsata. Temporal expression profiles obtained by quantitative real-time PCR revealed that Fox genes have distinct expression patterns in A. cerana, especially for three genes ACSNU03719T0 (AcFoxN4), ACSNU05765T0 (AcFoxB), and ACSNU07465T0 (AcFoxL2), which displayed high expression at the egg stage. Tissue expression patterns showed that FoxJ1 is significantly higher in the antennae of A. cerana and A. mellifera compared to other tissues. These results may facilitate a better understanding of the potential physiological functions of the Fox gene family in A. cerana and provide valuable information for a comprehensive functional analysis of the Fox gene family in Hymenopterans.

Different expression patterns of sperm motility-related genes in testis of diploid and tetraploid cyprinid fish†

Sperm motility is an important standard to measure the fertility of male. In our previous study, we found that the diploid spermatozoa from allotetraploid hybrid (4nAT) had longer durations of rapid and slow progressive motility than haploid spermatozoa from common carp (COC). In this study, to explore sperm motility-related molecular mechanisms, we compared the testis tissues transcriptomes from 2-year-old male COC and 4nAT. The RNA-seq data revealed that 2985 genes were differentially expressed between COC and 4nAT, including 2216 upregulated and 769 downregulated genes in 4nAT. Some differentially expressed genes, such as tubulin genes, dynein, axonemal, heavy chain(dnah) genes, mitogen-activated protein kinase(mapk) genes, tektin 4, FOX transcription factors, proteasome genes, and ubiquitin carboxyl-terminal hydrolase(uchl) genes, are involved in the regulation of cell division, flagellar and ciliary motility, gene transcription, cytoskeleton, energy metabolism, and the ubiquitin–proteasome system, suggesting that these genes were related to sperm motility of the 4nAT. We confirmed the differential expression of 12 such genes in 4nAT by quantitative PCR. By western blotting, we also confirmed increased expression of Uchl3 in 4nAT testis. In addition, we identified 1915 and 2551 predicted long noncoding RNA (lncRNA) transcripts from testis tissue transcriptomes of COC and 4nAT, respectively. Of these, 1575 lncRNAs were specifically expressed in 4nAT and 939 were specifically expressed in COC. This study provides insights into the transcriptome profile of testis tissues from diploid and tetraploid, which are useful for research on regulatory mechanisms behind sperm motility in male polyploidy.

A Testis-Specific Long Non-Coding RNA, lncRNA-Tcam1, Regulates Immune-Related Genes in Mouse Male Germ Cells

Spermatogenesis is precisely controlled by hormones from the hypothalamus-pituitary-gonadal axis and testis-specific genes, but the regulatory mechanism is not fully understood. Recently, a large number of long non-coding RNAs (lncRNAs) are found to be transcribed at each stage of meiosis of male germ cells, and their functions in spermatogenesis have yet to be fully investigated. lncRNA-testicular cell adhesion molecule 1 (lncRNA-Tcam1) is a nuclear lncRNA which is specifically expressed in mouse male germ cells and presumed to play a role in gene regulation during meiosis. Here, we present the identification of potential target genes of lncRNA-Tcam1 using spermatocyte-derived GC-2spd(ts) cells. Initially, 55 target gene candidates were detected by RNA-sequencing of two GC-2spd(ts) cell clones that were stably transfected with transgenes to express lncRNA-Tcam1 at different levels. Expression of 21 genes of the candidates was found to be correlated with lncRNA-Tcam1 at 7-14 postnatal days, when lncRNA-Tcam1 expression was elevated. Subsequently, we examined expression levels of the 21 genes in other two GC-2spd(ts) clones, and 11 genes exhibited the correlation with lncRNA-Tcam1. Induction of lncRNA-Tcam1 transcription using the Tet-off system verified that six genes, Trim30a, Ifit3, Tgtp2, Ifi47, Oas1g, and Gbp3, were upregulated in GC-2spd(ts) cells, indicating that lncRNA-Tcam1 is responsible for the regulation of gene expression of the six genes. In addition, five of the six genes, namely, Ifit3, Tgtp2, Ifi47, Oas1g, and Gbp3, are immune response genes, and Trim30a is a negative regulator of immune response. Altogether, the present study suggests that lncRNA-Tcam1 is responsible for gene regulation for the immune response during spermatogenesis.

Multiple roles of FOXJ3 in spermatogenesis: A lesson from Foxj3 conditional knockout mouse models

The transcription factor FOXJ3 (Forkhead box J3) is highly expressed in spermatogonia and meiotic spermatocytes within mouse testes. Here, we addressed how FOXJ3 might participate in spermatogenesis using two conditional knockout mouse models in which Foxj3 was deleted from either spermatogonia or meiotic spermatocytes. Both models exhibited complete male sterility, but distinct etiologies: Deleting FOXJ3 from spermatogonia using Foxj3^flox/flox , Mvh-Cre mice caused Sertoli-cell-only syndrome in males. Foxj3-deficient spermatogonia were lost as early as postnatal Day 4, partially due to the accumulation of DNA double-stranded breaks. In contrast, loss of FOXJ3 in spermatocytes using Foxj3^flox/flox , Stra8-Cre mice led to meiotic arrest. Indeed, the mRNA abundance of meiotic arrest-related proteins (Rad51, Dmc1, Brca1, Brca2, Brit1, Eif4g3, Hop2, Hormad1, and Rnf212) was significantly reduced in Foxj3^flox/flox , Stra8-Cre spermatocytes. Thus, we conclude that FOXJ3 is required for the survival of spermatogonia and participates in spermatocyte meiosis. Mol. Reprod. Dev. 83: 1060-1069, 2016. © 2016 Wiley Periodicals, Inc.