A Rapid Evolving microRNA Cluster Rewires Its Target Regulatory Networks in Drosophila

New miRNAs are evolutionarily important but their functional evolution remains unclear. Here we report that the evolution of a microRNA cluster, mir-972C rewires its downstream regulatory networks in Drosophila. Genomic analysis reveals that mir-972C originated in the common ancestor of Drosophila where it comprises six old miRNAs. It has subsequently recruited six new members in the melanogaster subgroup after evolving for at least 50 million years. Both the young and the old mir-972C members evolved rapidly in seed and non-seed regions. Combining target prediction and cell transfection experiments, we found that the seed and non-seed changes in individual mir-972C members cause extensive target divergence among D. melanogaster, D. simulans, and D. virilis, consistent with the functional evolution of mir-972C reported recently. Intriguingly, the target pool of the cluster as a whole remains relatively conserved. Our results suggest that clustering of young and old miRNAs broadens the target repertoires by acquiring new targets without losing many old ones. This may facilitate the establishment of new miRNAs in existing regulatory networks.

Transcriptomic, Proteomic, and Metabolic Profiles of Catalpa bungei Tension Wood Reveal New Insight Into Lignin Biosynthesis Involving Transcription Factor Regulation

Lignin is a complex polymer in plant cell walls whose proportion is second only to that of cellulose and plays an important role in the mechanical properties of wood and stress resistance of plants. Here, we induced tension wood (TW) formation in Catalpa bungei by artificial bending and analyzed the lignin metabolism of the TW. LC-MS analysis showed that a significantly higher content of coniferyl aldehyde was observed in the TW cell wall than in the opposite wood (OW) and normal wood (NW) cell walls. TW had significantly lower contents of coniferyl alcohol than OW and NW. Raman spectroscopy results indicated that TW had lower total lignin than OW and NW. The transcription and translation levels of most of the differentially expressed genes (DEGs) involved in lignin monomer biosynthesis indicated upregulation in TW/OW and TW/NW. We found no significant difference in the transcription levels of three collision gases (CADs) between TW and OW or between NW, but their translation levels were significantly downregulated in TW, suggesting post-transcriptional control for CAD. We predicted and analyzed transcription factors that could target DEGs involved in lignin monomer biosynthesis in TW. Based on the analysis of the relationships of targeting and coexpression, we found that NAC (evm.model.group1.695) could potentially target 4CLs and CCoAOMT, that HD-Zip (evm.model.group7.1157) had potential targeting relationships with CCoAOMT, F5H, and CCR, and that their expression levels were significantly positive. It is speculated that the upregulation of NAC and HD-ZIP transcription factors activates the expression of downstream target genes, which leads to a significant increase in coniferyl aldehyde in TW. However, the decrease in total lignin in TW may be caused by the significant downregulation of CAD translation and the significant decrease in precursors (coniferyl alcohol). Whether the expression of CAD genes is regulated by post-transcriptional control and affects TW lignin metabolism needs further study.

Molecular Evolution of Calcium Signaling and Transport in Plant Adaptation to Abiotic Stress

Adaptation to unfavorable abiotic stresses is one of the key processes in the evolution of plants. Calcium (Ca2+) signaling is characterized by the spatiotemporal pattern of Ca2+ distribution and the activities of multi-domain proteins in integrating environmental stimuli and cellular responses, which are crucial early events in abiotic stress responses in plants. However, a comprehensive summary and explanation for evolutionary and functional synergies in Ca2+ signaling remains elusive in green plants. We review mechanisms of Ca2+ membrane transporters and intracellular Ca2+ sensors with evolutionary imprinting and structural clues. These may provide molecular and bioinformatics insights for the functional analysis of some non-model species in the evolutionarily important green plant lineages. We summarize the chronological order, spatial location, and characteristics of Ca2+ functional proteins. Furthermore, we highlight the integral functions of calcium-signaling components in various nodes of the Ca2+ signaling pathway through conserved or variant evolutionary processes. These ultimately bridge the Ca2+ cascade reactions into regulatory networks, particularly in the hormonal signaling pathways. In summary, this review provides new perspectives towards a better understanding of the evolution, interaction and integration of Ca2+ signaling components in green plants, which is likely to benefit future research in agriculture, evolutionary biology, ecology and the environment.

Transcription Factors From Haematococcus pluvialis Involved in the Regulation of Astaxanthin Biosynthesis Under High Light-Sodium Acetate Stress

The microalgae Haematococcus pluvialis attracts attention for its ability to accumulate astaxanthin up to its 4% dry weight under stress conditions, such as high light, salt stress, and nitrogen starvation. Previous researches indicated that the regulation of astaxanthin synthesis might happen at the transcriptional level. However, the transcription regulatory mechanism of astaxanthin synthesis is still unknown in H. pluvialis. Lacking studies on transcription factors (TFs) further hindered from discovering this mechanism. Hence, the transcriptome analysis of H. pluvialis under the high light-sodium acetate stress for 1.5 h was performed in this study, aiming to discover TFs and the regulation on astaxanthin synthesis. In total, 83,869 unigenes were obtained and annotated based on seven databases, including NR, NT, Kyoto Encyclopedia of Genes and Genomes Orthology, SwissProt, Pfam, Eukaryotic Orthologous Groups, and Gene Ontology. Moreover, 476 TFs belonging to 52 families were annotated by blasting against the PlantTFDB database. By comparing with the control group, 4,367 differentially expressed genes composing of 2,050 upregulated unigenes and 2,317 downregulated unigenes were identified. Most of them were involved in metabolic process, catalytic activity, single-organism process, single-organism cellular process, and single-organism metabolic process. Among them, 28 upregulated TFs and 41 downregulated TFs belonging to 27 TF families were found. The transcription analysis showed that TFs had different transcription modules responding to the high light and sodium acetate stress. Interestingly, six TFs belonging to MYB, MYB_related, NF-YC, Nin-like, and C3H families were found to be involved in the transcription regulation of 27 astaxanthin synthesis-related genes according to the regulatory network. Moreover, these TFs might affect astaxanthin synthesis by directly regulating CrtO, showing that CrtO was the hub gene in astaxanthin synthesis. The present study provided new insight into a global view of TFs and their correlations to astaxanthin synthesis in H. pluvialis.

Integrative Analysis Reveals a miRNA-mRNA Regulatory Network and Potential Causative Agents in the Asthmatic Airway Epithelium

Background

During asthma progression, the intricate molecular networks, including microRNA (miRNA) transcriptional regulation in airway epithelium, remain largely undefined. The abnormal expression of miRNAs in asthmatic airway epithelium is a recent and fast-growing area in developing diagnostic and therapeutic targets for asthma.

Material and Methods

Analyses were conducted to compare airway epithelial miRNAs and gene expression between patients with asthma and healthy subjects from three datasets (two for miRNAs expression profiles and one for gene expression profile). The interactions network between differentially expressed (DE)-miRNAs and mRNAs was further identified for functional analysis. To verify the involvement and functions of all the identified miRNAs in asthma, we constructed two cellular models of asthma. The most promising causal miRNA candidate, miR-1246, was examined in an in vitro system to explore its targets and roles in asthma pathophysiology.

Results

Through integrative analysis, we obtained six miRNAs with 31 validated target genes in airway epithelium associated with asthma. Next, we confirmed that these miRNAs were all associated with asthma progression by in vitro functional experiments. They may participate in eosinophilic inflammation (miR-92b-3p, miR-1246, miR-197-3p, and miR-124-5p) or remodeling (miR-197-3p, miR-193a-5p, miR-1246, and miR-92b-3p). Additionally, some other non-screened valuable miRNAs were also examined and identified (miR-21-5p and miR-19b-3p), and some detected in blood correlated with the disease status. Furthermore, we found that miR-1246 could directly target POSTN and influence epithelial-to-mesenchymal transition and fibrosis in airway epithelial cells.

Conclusion

We constructed a preliminary epithelial regulatory network in asthma based on six identified miRNAs and their valuable target genes. Candidate factors in the biological miRNA-mRNA network in airway epithelium may provide further information on the pathogenesis of asthma. Strikingly, among all screened miRNAs, miR-1246, which could interact with POSTN may have multifunctional effects in the course of asthma and be a promising agent for asthma treatment and molecular subtyping.

Continuous Modeling of T CD4 Lymphocyte Activation and Function

T CD4+ cells are central to the adaptive immune response against pathogens. Their activation is induced by the engagement of the T-cell receptor by antigens, and of co-stimulatory receptors by molecules also expressed on antigen presenting cells. Then, a complex network of intracellular events reinforce, diversify and regulate the initial signals, including dynamic metabolic processes that strongly influence both the activation state and the differentiation to effector cell phenotypes. The regulation of cell metabolism is controlled by the nutrient sensor adenosine monophosphate-activated protein kinase (AMPK), which drives the balance between oxidative phosphorylation (OXPHOS) and glycolysis. Herein, we put forward a 51-node continuous mathematical model that describes the temporal evolution of the early events of activation, integrating a circuit of metabolic regulation into the main routes of signaling. The model simulates the induction of anergy due to defective co-stimulation, the CTLA-4 checkpoint blockade, and the differentiation to effector phenotypes induced by external cytokines. It also describes the adjustment of the OXPHOS-glycolysis equilibrium by the action of AMPK as the effector function of the T cell develops. The development of a transient phase of increased OXPHOS before induction of a sustained glycolytic phase during differentiation to the Th1, Th2 and Th17 phenotypes is shown. In contrast, during Treg differentiation, glycolysis is subsequently reduced as cell metabolism is predominantly polarized towards OXPHOS. These observations are in agreement with experimental data suggesting that OXPHOS produces an ATP reservoir before glycolysis boosts the production of metabolites needed for protein synthesis, cell function, and growth.

Comparative Transcriptome Provides a Systematic Perspective on Epstein-Barr Virus-Associated Gastric Carcinoma Cell Lines

Purpose

Epstein–Barr virus (EBV) is widely recognised to cause various tumours, and EBV-associated gastric carcinoma (EBVaGC) is a special type of GC. It has obviously different clinical features and pathological manifestations from EBV-negative gastric carcinoma, but its progression remains elusive. The underlying cancer progression of viral infection detected by genome-wide transcriptome analysis has been demonstrated in numerous diseases.

Methods

We performed comparative RNA sequencing to identify gene expression signatures between GC and EBVaGC cell lines. The differentially expressed (DE) genes were analysed using gene ontology and pathway enrichment.

Results

A total of 4438 DE mRNAs, 3650 DE long non-coding RNAs (lncRNAs), and 248 DE circular RNAs (circRNAs) were detected in GC cells after EBV infection, most of which were highly related to oncogenesis. Likewise, EBV-coding RNA and non-coding RNA were also well-supplemented in EBVaGC. According to bioinformatics, DE mRNAs may contribute to the completion of EBV-infected host cells and modulate mitosis. Binding to actin and participating in adherens junctions to promote contact between the virus and cells are a potential function of DE lncRNAs. The roles of DE circRNAs were enriched in DNA repair and protein modification, and a typical example of this is acting as an miRNA sponge. The establishment of a circRNA-miRNA-mRNA network helps to determine the key elements in the progression of EBVaGC.

Conclusion

This study is the first to systematically reveal the transcriptome landscape of EBVaGC, which will provide an essential resource for genomic, genetic, and molecular mechanisms in the future.

Proteomic analysis of metabolic mechanisms associated with fatty acid biosynthesis during Styrax tonkinensis kernel development

BACKGROUND

Styrax tonkinensis is a white-flowered tree with considerable potential as a feedstock source for biodiesel production from the oily seed contained within its nutlike drupes. Transcriptome changes during oil accumulation have been previously reported, but not concurrent changes in the proteome.

RESULTS

Using proteomic analysis of samples collected at 50, 70, 100 and 130 days after flowering (DAF), we identified 1472 differentially expressed proteins (DEPs). Based on their expression patterns, we grouped the DEPs into nine clusters and analyzed the pathway enrichment. Proteins related to starch and sucrose metabolism were most abundant at 50 DAF. Proteins involved in fatty acid (FA) biosynthesis were mainly grouped into a cluster that peaked at 70 DAF. Proteins related to protein processing in endoplasmic reticulum had two major patterns, trending either upwards or downwards, while proteins involved in amino acid biosynthesis showed more complex relationships. We identified 42 key enzymes involved in lipid accumulation during kernel development, including the acetyl-CoA carboxylase complex (ACC) and the pyruvate dehydrogenase complex (PDC). One oil body membrane protein, oleosin, continuously increased during kernel development.

CONCLUSION

A regulatory network of oil accumulation processes was built based on protein and available transcriptome expression data, which were in good temporal agreement. This analysis placed ACC and PDC in the center of the network, suggesting that the glycolytic provision of substrate plays a central regulatory role in FA biosynthesis and oil accumulation. © 2021 Society of Chemical Industry.

Light Induced Regulation Pathway of Anthocyanin Biosynthesis in Plants

Anthocyanins are natural pigments with antioxidant effects that exist in various fruits and vegetables. The accumulation of anthocyanins is induced by environmental signals and regulated by transcription factors in plants. Numerous evidence has indicated that among the environmental factors, light is one of the most signal regulatory factors involved in the anthocyanin biosynthesis pathway. However, the signal transduction of light and molecular regulation of anthocyanin synthesis remains to be explored. Here, we focus on the research progress of signal transduction factors for positive and negative regulation in light-dependent and light-independent anthocyanin biosynthesis. In particular, we will discuss light-induced regulatory pathways and related specific regulators of anthocyanin biosynthesis in plants. In addition, an integrated regulatory network of anthocyanin biosynthesis controlled by transcription factors is discussed based on the significant progress.

Uncovering and Engineering a Mini-Regulatory Network of the TetR-Family Regulator SACE_0303 for Yield Improvement of Erythromycin in Saccharopolyspora erythraea

Erythromycins produced by Saccharopolyspora erythraea have broad-spectrum antibacterial activities. Recently, several TetR-family transcriptional regulators (TFRs) were identified to control erythromycin production by multiplex control modes; however, their regulatory network remains poorly understood. In this study, we report a novel TFR, SACE_0303, positively correlated with erythromycin production in Sac. erythraea. It directly represses its adjacent gene SACE_0304 encoding a MarR-family regulator and indirectly stimulates the erythromycin biosynthetic gene eryAI and resistance gene ermE. SACE_0304 negatively regulates erythromycin biosynthesis by directly inhibiting SACE_0303 as well as eryAI and indirectly repressing ermE. Then, the SACE_0303 binding site within the SACE_0303-SACE_0304 intergenic region was defined. Through genome scanning combined with in vivo and in vitro experiments, three additional SACE_0303 target genes (SACE_2467 encoding cation-transporting ATPase, SACE_3156 encoding a large transcriptional regulator, SACE_5222 encoding α-ketoglutarate permease) were identified and proved to negatively affect erythromycin production. Finally, by coupling CRISPRi-based repression of those three targets with SACE_0304 deletion and SACE_0303 overexpression, we performed stepwise engineering of the SACE_0303-mediated mini-regulatory network in a high-yield strain, resulting in enhanced erythromycin production by 67%. In conclusion, the present study uncovered the regulatory network of a novel TFR for control of erythromycin production and provides a multiplex tactic to facilitate the engineering of industrial actinomycetes for yield improvement of antibiotics.

Screening candidate genes related to volatile synthesis in shiitake mushrooms and construction of regulatory networks to effectively improve mushroom aroma

BACKGROUND

Metabolite formation is a physiological stress response during the growth and development of shiitake mushrooms (Lentinula edodes). The characteristic flavor metabolites are important quality components in shiitake mushrooms. To investigate the formation mechanisms of characteristic flavor metabolites, transcriptome analyses were performed on shiitake mushrooms harvested at different growth stages.

RESULTS

In total, 30 genes related to the synthesis of characteristic volatiles of mushrooms were identified via screening. Through KEGG (Kyoto Encyclopedia of Genes and Genomes) enrichment analysis of the selected genes and correlation analyses of gene expressions, the main volatile synthesis pathways were determined as histidine metabolism, glutathione metabolism and biosynthesis of unsaturated fatty acids. Gene cluster and correlation analyses were performed to clarify the combined effects of different genes in the enzymatic reactions. Further, a correlation network of candidate genes was built based on the gene expression levels.

CONCLUSION

The activities of flavor synthases and the content of characteristic flavor metabolites were analyzed; the enzyme activity changes and metabolic product distribution sites were clarified. A synthesis and regulation network was constructed for the candidate genes and characteristic volatiles, and information was obtained for 16 hub genes. Moreover, it was essential to identify and characterize the key genes and synthases involved in the synthesis of the characteristic volatiles of mushrooms. This information provides us with a better understanding of the biosynthesis and regulation of the volatiles, which will lay the foundation for improving the quality of shiitake mushrooms. © 2021 Society of Chemical Industry.

Critical microRNAs and regulatory motifs in cleft palate identified by a conserved miRNA-TF-gene network approach in humans and mice

Cleft palate (CP) is the second most common congenital birth defect. The etiology of CP is complicated, with involvement of various genetic and environmental factors. To investigate the gene regulatory mechanisms, we designed a powerful regulatory analytical approach to identify the conserved regulatory networks in humans and mice, from which we identified critical microRNAs (miRNAs), target genes and regulatory motifs (miRNA-TF-gene) related to CP. Using our manually curated genes and miRNAs with evidence in CP in humans and mice, we constructed miRNA and transcription factor (TF) co-regulation networks for both humans and mice. A consensus regulatory loop (miR17/miR20a-FOXE1-PDGFRA) and eight miRNAs (miR-140, miR-17, miR-18a, miR-19a, miR-19b, miR-20a, miR-451a and miR-92a) were discovered in both humans and mice. The role of miR-140, which had the strongest association with CP, was investigated in both human and mouse palate cells. The overexpression of miR-140-5p, but not miR-140-3p, significantly inhibited cell proliferation. We further examined whether miR-140 overexpression could suppress the expression of its predicted target genes (BMP2, FGF9, PAX9 and PDGFRA). Our results indicated that miR-140-5p overexpression suppressed the expression of BMP2 and FGF9 in cultured human palate cells and Fgf9 and Pdgfra in cultured mouse palate cells. In summary, our conserved miRNA-TF-gene regulatory network approach is effective in detecting consensus miRNAs, motifs, and regulatory mechanisms in human and mouse CP.

Association of miR-499 Polymorphism and Its Regulatory Networks with Hashimoto Thyroiditis Susceptibility: A Population-Based Case-Control Study

Hashimoto thyroiditis (HT) is a common autoimmune disorder with a strong genetic background. Several genetic factors have been suggested, yet numerous genetic contributors remain to be fully understood in HT pathogenesis. MicroRNAs (miRs) are gene expression regulators critically involved in biological processes, of which polymorphisms can alter their function, leading to pathologic conditions, including autoimmune diseases. We examined whether miR-499 rs3746444 polymorphism is associated with susceptibility to HT in an Iranian subpopulation. Furthermore, we investigated the potential interacting regulatory network of the miR-499. This case-control study included 150 HT patients and 152 healthy subjects. Genotyping of rs3746444 was performed by the PCR-RFLP method. Also, target genomic sites of the polymorphism were predicted using bioinformatics. Our results showed that miR-499 rs3746444 was positively associated with HT risk in heterozygous (OR = 3.32, 95%CI = 2.00–5.53, p < 0.001, CT vs. TT), homozygous (OR = 2.81, 95%CI = 1.30–6.10, p = 0.014, CC vs. TT), dominant (OR = 3.22, 95%CI = 1.97–5.25, p < 0.001, CT + CC vs. TT), overdominant (OR = 2.57, 95%CI = 1.62–4.09, p < 0.001, CC + TT vs. CT), and allelic (OR = 1.92, 95%CI = 1.37–2.69, p < 0.001, C vs. T) models. Mapping predicted target genes of miR-499 on tissue-specific-, co-expression-, and miR-TF networks indicated that main hub-driver nodes are implicated in regulating immune system functions, including immunorecognition and complement activity. We demonstrated that miR-499 rs3746444 is linked to HT susceptibility in our population. However, predicted regulatory networks revealed that this polymorphism is contributing to the regulation of immune system pathways.

The role of RNA m5C modification in cancer metastasis

Epigenetic modification plays a crucial regulatory role in the biological processes of eukaryotic cells. The recent characterization of DNA and RNA methylation is still ongoing. Tumor metastasis has long been an unconquerable feature in the fight against cancer. As an inevitable component of the epigenetic regulatory network, 5-methylcytosine is associated with multifarious cellular processes and systemic diseases, including cell migration and cancer metastasis. Recently, gratifying progress has been achieved in determining the molecular interactions between m⁵C writers (DNMTs and NSUNs), demethylases (TETs), readers (YTHDF2, ALYREF and YBX1) and RNAs. However, the underlying mechanism of RNA m⁵C methylation in cell mobility and metastasis remains unclear. The functions of m⁵C writers and readers are believed to regulate gene expression at the post-transcription level and are involved in cellular metabolism and movement. In this review, we emphatically summarize the recent updates on m⁵C components and related regulatory networks. The content will be focused on writers and readers of the RNA m⁵C modification and potential mechanisms in diseases. We will discuss relevant upstream and downstream interacting molecules and their associations with cell migration and metastasis.

Chromosome-level genome assembly of Gynostemma pentaphyllum provides insights into gypenoside biosynthesis

Gynostemma pentaphyllum (Thunb.) Makino is an economically valuable medicinal plant belonging to the Cucurbitaceae family that produces the bioactive compound gypenoside. Despite several transcriptomes having been generated for G. pentaphyllum, a reference genome is still unavailable, which has limited the understanding of the gypenoside biosynthesis and regulatory mechanism. Here, we report a high-quality G. pentaphyllum genome with a total length of 582 Mb comprising 1,232 contigs and a scaffold N50 of 50.78 Mb. The G. pentaphyllum genome comprised 59.14% repetitive sequences and 25,285 protein-coding genes. Comparative genome analysis revealed that G. pentaphyllum was related to Siraitia grosvenorii, with an estimated divergence time dating to the Paleogene (∼48 million years ago). By combining transcriptome data from seven tissues, we reconstructed the gypenoside biosynthetic pathway and potential regulatory network using tissue-specific gene co-expression network analysis. Four UDP-glucuronosyltransferases (UGTs), belonging to the UGT85 subfamily and forming a gene cluster, were involved in catalyzing glycosylation in leaf-specific gypenoside biosynthesis. Furthermore, candidate biosynthetic genes and transcription factors involved in the gypenoside regulatory network were identified. The genetic information obtained in this study provides insights into gypenoside biosynthesis and lays the foundation for further exploration of the gypenoside regulatory mechanism.

Meis1, Hi1α, and GATA1 are integrated into a hierarchical regulatory network to mediate primitive erythropoiesis

During development, erythroid cells are generated by two waves of hematopoiesis. In zebrafish, primitive erythropoiesis takes place in the intermediate cell mass region, and definitive erythropoiesis arises from the aorta-gonad mesonephros. TALE-homeoproteins Meis1 and Pbx1 function upstream of GATA1 to specify the erythroid lineage. Embryos lacking Meis1 or Pbx1 have weak gata1 expression and fail to produce primitive erythrocytes. Nevertheless, the underlying mechanism of how Meis1 and Pbx1 mediate gata1 transcription in erythrocytes remains unclear. Here we show that Hif1α acts downstream of Meis1 to mediate gata1 expression in zebrafish embryos. Inhibition of Meis1 expression resulted in suppression of hif1a expression and abrogated primitive erythropoiesis, while injection with in vitro-synthesized hif1α mRNA rescued gata1 transcription in Meis1 morphants and recovered their erythropoiesis. Ablation of Hif1α expression either by morpholino knockdown or Crispr-Cas9 knockout suppressed gata1 transcription and abrogated primitive erythropoiesis. Results of chromatin immunoprecipitation assays showed that Hif1α associates with hypoxia-response elements located in the 3'-flanking region of gata1 during development, suggesting that Hif1α regulates gata1 expression in vivo. Together, our results indicate that Meis1, Hif1α, and GATA1 indeed comprise a hierarchical regulatory network in which Hif1α acts downstream of Meis1 to activate gata1 transcription through direct interactions with its cis-acting elements in primitive erythrocytes.

Multiplatform discovery and regulatory function analysis of structural variations in non-small cell lung carcinoma

Non-small cell lung carcinoma (NSCLC), the most common form of lung cancer, is the leading cause of cancer-related death worldwide. We perform whole-genome sequencing (WGS) on samples from 43 primary patients with NSCLC and matched normal samples and analyze their matched open chromatin data and transcriptome data. Our results indicate that next-generation sequencing (NGS) and the Bionano Genomics (BNG) platform should be viewed as complementary technologies in terms of structural variations detection. By creating a framework integrating these two platforms, we detect high-technical-confidence somatic structural variations (SVs) in NSCLC cases, which could aid in the efficient investigation of new candidate oncogenes, such as TRIO and SESTD1. Our findings highlight the impact of somatic SVs on NSCLC oncogenesis and lay a foundation for exploring associations among somatic SVs, gene expression, and regulatory networks in patients with NSCLC.

Transcriptome and Resequencing Analyses Provide Insight into Differences in Organic Acid Accumulation in Two Pear Varieties

Fruit acidity is one of the main determinants of fruit flavor and a target trait in fruit breeding. However, the genomic mechanisms governing acidity variation among different pear varieties remain poorly understood. In this study, two pear varieties with contrasting organic acid levels, ‘Dangshansuli’ (low-acidity) and ‘Amute’ (high-acidity), were selected, and a combination of transcriptome and population genomics analyses were applied to characterize their patterns of gene expression and genetic variation. Based on RNA-seq data analysis, differentially expressed genes (DEGs) involved in organic acid metabolism and accumulation were identified. Weighted correlation network analysis (WGCNA) revealed that nine candidate TCA (tricarboxylic acid)-related DEGs and three acid transporter-related DEGs were located in three key modules. The regulatory networks of the above candidate genes were also predicted. By integrating pear resequencing data, two domestication-related genes were found to be upregulated in ‘Amute’, and this trend was further validated for other pear varieties with high levels of organic acid, suggesting distinct selective sweeps during pear dissemination and domestication. Collectively, this study provides insight into organic acid differences related to expression divergence and domestication in two pear varieties, pinpointing several candidate genes for the genetic manipulation of acidity in pears.

Using the lineage determinants Olig2 and Sox10 to explore transcriptional regulation of oligodendrocyte development

The transcription factors Olig2 and Sox10 jointly define oligodendroglial identity. Because of their continuous presence during development and in the differentiated state they shape the oligodendroglial regulatory network at all times. In this review, we exploit their eminent role and omnipresence to elaborate the central principles that organize the gene regulatory network in oligodendrocytes in such a way that it preserves its identity, but at the same time allows defined and stimulus-dependent changes that result in an ordered lineage progression, differentiation, and myelination. For this purpose, we outline the multiple functional and physical interactions and intricate cross-regulatory relationships with other transcription factors, such as Hes5, Id, and SoxD proteins, in oligodendrocyte precursors and Tcf7l2, Sip1, Nkx2.2, Zfp24, and Myrf during differentiation and myelination, and interpret them in the context of the regulatory network.

A TIMM17A Regulatory Network Contributing to Breast Cancer

Background

Translocase of inner mitochondrial membrane 17A (TIMM17A) is overexpressed in breast cancer (BRCA), and upregulation can increase the aggressiveness of BRCA cells. This study examined the influence of the TIMM17A gene network on BRCA outcome.

Methods

Expression levels of TIMM17A were compared between normal and tumor tissues from the Oncomine^TM database, and the association with patient survival was analyzed using Kaplan–Meier Plotter. Clinical factors influencing TIMM17A expression were studied by UALCAN. cBioPotal was then used to identify genes interacting with TIMM17A, and network relationships were assessed using the R clusterProfiler package. The association between TIMM17A mutation and mRNA expression in BRCA was examined using the LinkFinder application in LinkedOmics, and coexpressed genes were assessed for functional enrichment using the LinkInterpreter application. Furthermore, TIMM17A expression correlation with cell cycle phase distribution was performed by flow cytometry. Finally, the target networks of kinases, microRNAs (miRNAs), and transcription factors were identified using GeneMANIA. The expression and correlation of potential miRNAs and targets were further validated in BRCA cell lines by qRT-PCR.

Results

Expression of TIMM17A was significantly elevated in BRCA compared with normal tissue (p < 0.05), and overexpression was associated with both poor overall survival (OS) and shorter distant metastasis-free survival (DMFS) (p < 0.05). Expression of TIMM17A was not associated with age, sex, BRCA subclass, clinical stage, or patient ethnicity. The coexpressed TIMM17A network was enriched in genes targeted by cell cycle regulators such as CDK1, miR-331, and E2F family transcription factors (FDR < 0.001). Furthermore, flow cytometry revealed a strong association between higher TIMM17A expression and faster cell cycle progression in these BRCA cell lines. In addition, expression of TIMM17A protein was correlated with CDK1 protein expression in BRCA cell lines as measured by western blotting.

Conclusion

Elevated TIMM17A expression accelerates the progression of BRCA, thereby reducing OS and DMFS. The TIMM17A-associated networks identified here provide clues to the molecular pathogenesis of BRCA and potential targets for BRCA treatment.

Morphological, Physiological, and Molecular Responses of Sweetly Fragrant Luculia gratissima During the Floral Transition Stage Induced by Short-Day Photoperiod

Photoperiod-regulated floral transition is vital to the flowering plant. Luculia gratissima "Xiangfei" is a flowering ornamental plant with high development potential economically and is a short-day woody perennial. However, the genetic regulation of short-day-induced floral transition in L. gratissima is unclear. To systematically research the responses of L. gratissima during this process, dynamic changes in morphology, physiology, and transcript levels were observed and identified in different developmental stages of long-day- and short-day-treated L. gratissima plants. We found that floral transition in L. gratissima occurred 10 d after short-day induction, but flower bud differentiation did not occur at any stage under long-day conditions. A total of 1,226 differentially expressed genes were identified, of which 146 genes were associated with flowering pathways of sugar, phytohormones, photoperiod, ambient temperature, and aging signals, as well as floral integrator and meristem identity genes. The trehalose-6-phosphate signal positively modulated floral transition by interacting with SQUAMOSA PROMOTER-BINDING-LIKE PROTEIN 4 (SPL4) in the aging pathway. Endogenous gibberellin, abscisic acid, cytokinin, and jasmonic acid promoted floral transition, whereas strigolactone inhibited it. In the photoperiod pathway, FD, CONSTANS-LIKE 12, and nuclear factors Y positively controlled floral transition, whereas PSEUDO-RESPONSE REGULATOR 7, FLAVIN-BINDING KELCH REPEAT F-BOX PROTEIN 1, and LUX negatively regulated it. SPL4 and pEARLI1 positively affected floral transition. Suppressor of Overexpression of Constans 1 and AGAMOUSLIKE24 integrated multiple flowering signals to modulate the expression of FRUITFULL/AGL8, AP1, LEAFY, SEPALLATAs, SHORT VEGETATIVE PHASE, and TERMINAL FLOWER 1, thereby regulating floral transition. Finally, we propose a regulatory network model for short-day-induced floral transition in L. gratissima. This study improves our understanding of flowering time regulation in L. gratissima and provides knowledge for its production and commercialization.

Discrete Dynamic Model of the Mammalian Sperm Acrosome Reaction: The Influence of Acrosomal pH and Physiological Heterogeneity

The acrosome reaction (AR) is an exocytotic process essential for mammalian fertilization. It involves diverse physiological changes (biochemical, biophysical, and morphological) that culminate in the release of the acrosomal content to the extracellular medium as well as a reorganization of the plasma membrane (PM) that allows sperm to interact and fuse with the egg. In spite of many efforts, there are still important pending questions regarding the molecular mechanism regulating the AR. Particularly, the contribution of acrosomal alkalinization to AR triggering physiological conditions is not well understood. Also, the dependence of the proportion of sperm capable of undergoing AR on the physiological heterogeneity within a sperm population has not been studied. Here, we present a discrete mathematical model for the human sperm AR based on the physiological interactions among some of the main components of this complex exocytotic process. We show that this model can qualitatively reproduce diverse experimental results, and that it can be used to analyze how acrosomal pH (pH a ) and cell heterogeneity regulate AR. Our results confirm that a pH a increase can on its own trigger AR in a subpopulation of sperm, and furthermore, it indicates that this is a necessary step to trigger acrosomal exocytosis through progesterone, a known natural inducer of AR. Most importantly, we show that the proportion of sperm undergoing AR is directly related to the detailed structure of the population physiological heterogeneity.

The Role and Regulatory Network of the CiaRH Two-Component System in Streptococcal Species

Pathogenic streptococcal species are responsible for a broad spectrum of human diseases ranging from non-invasive and localized infections to more aggressive and life-threatening diseases, which cause great economic losses worldwide. Streptococci possess a dozen two-component systems (TCSs) that play important roles in the response to different environmental changes and adjust the expression of multiple genes to successfully colonize and infect host cells. In this review, we discuss the progress in the study of a conserved TCS named CiaRH in pathogenic or opportunistic streptococci including Streptococcus pneumoniae, Streptococcus pyogenes, Streptococcus agalactiae, Streptococcus mutans, Streptococcus gordonii, Streptococcus sanguinis, and Streptococcus suis, focusing on the function and regulatory networks of CiaRH, which will provide a promising strategy for the exploration of novel antistreptococcal therapies. This review highlights the important role of CiaRH and provides an important basis for the development of antistreptococcal drugs and vaccines.

The LysR-Type Transcriptional Regulator BsrA (PA2121) Controls Vital Metabolic Pathways in Pseudomonas aeruginosa

Pseudomonas aeruginosa, a facultative human pathogen causing nosocomial infections, has complex regulatory systems involving many transcriptional regulators. LTTR (LysR-Type Transcriptional Regulator) family proteins are involved in the regulation of various processes, including stress responses, motility, virulence, and amino acid metabolism. The aim of this study was to characterize the LysR-type protein BsrA (PA2121), previously described as a negative regulator of biofilm formation in P. aeruginosa. Genome wide identification of BsrA binding sites using chromatin immunoprecipitation and sequencing analysis revealed 765 BsrA-bound regions in the P. aeruginosa PAO1161 genome, including 367 sites in intergenic regions. The motif T-N₁₁-A was identified within sequences bound by BsrA. Transcriptomic analysis showed altered expression of 157 genes in response to BsrA excess; of these, 35 had a BsrA binding site within their promoter regions, suggesting a direct influence of BsrA on the transcription of these genes. BsrA-repressed loci included genes encoding proteins engaged in key metabolic pathways such as the tricarboxylic acid cycle. The panel of loci possibly directly activated by BsrA included genes involved in pilus/fimbria assembly, as well as secretion and transport systems. In addition, DNA pull-down and regulatory analyses showed the involvement of PA2551, PA3398, and PA5189 in regulation of bsrA expression, indicating that this gene is part of an intricate regulatory network. Taken together, these findings reveal the existence of a BsrA regulon, which performs important functions in P. aeruginosa.

IMPORTANCE This study shows that BsrA, a LysR-type transcriptional regulator from Pseudomonas aeruginosa, previously identified as a repressor of biofilm synthesis, is part of an intricate global regulatory network. BsrA acts directly and/or indirectly as the repressor and/or activator of genes from vital metabolic pathways (e.g., pyruvate, acetate, and tricarboxylic acid cycle) and is involved in control of transport functions and the formation of surface appendages. Expression of the bsrA gene is increased in the presence of antibiotics, which suggests its induction in response to stress, possibly reflecting the need to redirect metabolism under stressful conditions. This is particularly relevant for the treatment of infections caused by P. aeruginosa. In summary, the findings of this study demonstrate that the BsrA regulator performs important roles in carbon metabolism, biofilm formation, and antibiotic resistance in P. aeruginosa.

Data mining of differentially expressed genes in epithelial ovarian carcinoma: Implications in precise medicine

BACKGROUND

Epithelial ovarian carcinoma (EOC) is a ubiquitous gynecological malignancy with complicated pathogenesis. Genetic risk factors and pathways involved in the prognosis of this cancer are not yet understood completely. Determining genetic markers with diagnostic and prognostic values would pave the way for efficient management of cancer.

OBJECTIVE

This study aimed to investigate the genes and the regulatory networks involved in the occurrence and prognosis of EOC through different bioinformatics analysis tools. In addition, recent advances in using bioinformatic analysis approach based on the genes and regulatory networks, particularly differentially expressed genes (DEGs), in improving the diagnosis and prognosis of EOC are discussed.

METHODS

The gene expression profiles of GSE18520, GSE54388, and GSE27651 were downloaded from the Gene Expression Omnibus (GEO) database and further analyzed with different analyses in R language. Current literature on using bioinformatics based on DEGs and associated regulatory networks to improve the diagnosis and prognosis of EOC were reviewed.

RESULTS

Analyses of the gene expression levels between the malignant tissue against normal tissue unveiled 163 DEGs. Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed on the target genes using clusterProfiler package, and Cytoscape package was employed to assess the protein interaction network of these genes. The protein-protein interaction network was analyzed using the CytoHubba plug-in to identify 20 hub genes. In addition, we analyzed the prognosis of the hub genes using the Kaplan-Meier survival analysis that revealed evident differences in the prognosis of 13 genes. The malignant tissues exhibited a differential expression of 12 genes against healthy tissues, as shown by Gene Expression Profiling Interactive Analysis (GEPIA) analysis.

CONCLUSION

Findings of this study revealed 12 genes to be significantly up-regulated, and the prognosis was significantly different, which could be employed to potentially target EOC in clinical practice.

Comparative Transcriptome Analysis Reveals Regulatory Networks during the Maize Ear Shank Elongation Process

In maize, the ear shank is a short branch that connects the ear to the stalk. The length of the ear shank mainly affects the transportation of photosynthetic products to the ear, and also influences the dehydration of the grain by adjusting the tightness of the husks. However, the molecular mechanisms of maize shank elongation have rarely been described. It has been reported that the maize ear shank length is a quantitative trait, but its genetic basis is still unclear. In this study, RNA-seq was performed to explore the transcriptional dynamics and determine the key genes involved in maize shank elongation at four different developmental stages. A total of 8145 differentially expressed genes (DEGs) were identified, including 729 transcription factors (TFs). Some important genes which participate in shank elongation were detected via function annotation and temporal expression pattern analyses, including genes related to signal transduction hormones (auxin, brassinosteroids, gibberellin, etc.), xyloglucan and xyloglucan xyloglucosyl transferase, and transcription factor families. The results provide insights into the genetic architecture of maize ear shanks and developing new varieties with ideal ear shank lengths, enabling adjustments for mechanized harvesting in the future.

Bioinformatics Analysis of Choriocarcinoma-Related MicroRNA-Transcription Factor-Target Gene Regulatory Networks and Validation of Key miRNAs

Objective

The aim of the current research was to construct a miRNA-transcription factor (TF)-target gene regulatory network in order to investigate the mechanism underlying choriocarcinoma and to verify the network through the overexpression or silencing of hub miRNAs in vitro.

Materials and Methods

A mRNA expression dataset and two miRNA expression datasets were analysed to identify differentially expressed genes (DEGs) and miRNAs (DEMs) between normal cells and choriocarcinoma cells. The top 400 upregulated and downregulated DEGs were identified as candidate DEGs, which were then mapped to construct protein–protein interaction (PPI) networks and select hub genes. Moreover, the DGIdb database was utilized to select candidate drugs for hub genes. Moreover, DEM target genes were predicted through the miRWalk2.0 database and overlaid with candidate DEGs to identify the differentially expressed target genes (DETGs). Furthermore, we established miRNA-TF-target gene regulatory networks and performed functional enrichment analysis of hub DEMs. Finally, we transfected mimics or inhibitors of hub DEMs into choriocarcinoma cells and assessed cell proliferation and migration to verify the vital role of hub DEMs in choriocarcinoma.

Results

A total of 140 DEMs and 400 candidate DEGs were screened from choriocarcinoma cells and normal cells. A PPI network of 400 candidate DEGs was established. Twenty-nine hub genes and 99 associated small molecules were identified to provide potential target drugs for choriocarcinoma treatment. We obtained 70 DETGs of DEMs derived from the intersection between predicted miRNA target genes and candidate DEGs. Subsequently, 3 hub DEMs were selected, and miRNA-TF-target gene regulatory networks containing 4 TFs, 3 TFs and 3 TFs for each network were constructed. The RT-PCR results confirmed that miR-29b-3p was highly expressed and that miR-519c-3p and miR-520a-5p were expressed at low levels in choriocarcinoma cells. The overexpression or silencing results suggested that 3 dysregulated hub DEMs jointly accelerated the proliferation and migration of choriocarcinoma.

Conclusion

Association of miRNA-TF-target gene regulatory networks may help us explore the underlying mechanism and provide potential targets for the diagnosis and treatment of choriocarcinoma.

Corynebacterium glutamicum Regulation beyond Transcription: Organizing Principles and Reconstruction of an Extended Regulatory Network Incorporating Regulations Mediated by Small RNA and Protein-Protein Interactions

Corynebacterium glutamicum is a Gram-positive bacterium found in soil where the condition changes demand plasticity of the regulatory machinery. The study of such machinery at the global scale has been challenged by the lack of data integration. Here, we report three regulatory network models for C. glutamicum: strong (3040 interactions) constructed solely with regulations previously supported by directed experiments; all evidence (4665 interactions) containing the strong network, regulations previously supported by nondirected experiments, and protein-protein interactions with a direct effect on gene transcription; sRNA (5222 interactions) containing the all evidence network and sRNA-mediated regulations. Compared to the previous version (2018), the strong and all evidence networks increased by 75 and 1225 interactions, respectively. We analyzed the system-level components of the three networks to identify how they differ and compared their structures against those for the networks of more than 40 species. The inclusion of the sRNA-mediated regulations changed the proportions of the system-level components and increased the number of modules but decreased their size. The C. glutamicum regulatory structure contrasted with other bacterial regulatory networks. Finally, we used the strong networks of three model organisms to provide insights and future directions of the C.glutamicum regulatory network characterization.

Identification of RNA binding protein interacting with circular RNA and hub candidate network for hepatocellular carcinoma

The interaction between RNA binding protein (RBP) and circular RNA (circRNA) is important for the regulation of tumor progression. This study aimed to identify the RBP-circRNA network in hepatocellular carcinoma (HCC). 22 differentially expressed (DE) circRNAs in HCC were screened out from Gene Expression Omnibus (GEO) database and their binding RBPs were predicted by Circular RNA Interactome. Among them, 17 DERBPs, which were commonly dysregulated in HCC from The Clinical Proteomic Tumor Analysis Consortium (CPTAC), The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) projects, were utilized to construct the RBP-circRNA network. Through survival analysis, we found TARDBP was the only prognostic RBP for HCC in CPTAC, TCGA and ICGC projects. High expression of TARDBP was correlated with high grade, advanced stage and low macrophage infiltration of HCC. Additionally, gene set enrichment analysis showed that dysregulated TARDBP might be involved in some pathways related to the HCC pathogenesis. Therefore, a hub RBP-circRNA network was generated based on TARDBP. RNA immunoprecipitation and RNA pull-down confirmed that hsa_circ_0004913 binds to TARDBP. These findings indicated certain RBP-circRNA regulatory network potentially involved in the pathogenesis of HCC, which provides novel insights into the mechanism study and biomarker identification for HCC.

More stories to tell: NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1, a salicylic acid receptor

Salicylic acid (SA) plays pivotal role in plant defense against biotrophic and hemibiotrophic pathogens. Tremendous progress has been made in the field of SA biosynthesis and SA signaling pathways over the past three decades. Among the key immune players in SA signaling pathway, NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 (NPR1) functions as a master regulator of SA-mediated plant defense. The function of NPR1 as an SA receptor has been controversial; however, after years of arguments among several laboratories, NPR1 has finally been proven as one of the SA receptors. The function of NPR1 is strictly regulated via post-translational modifications and transcriptional regulation that were recently found. More recent advances in NPR1 biology, including novel functions of NPR1 and the structure of SA receptor proteins, have brought this field forward immensely. Therefore, based on these recent discoveries, this review acts to provide a full picture of how NPR1 functions in plant immunity and how NPR1 gene and NPR1 protein are regulated at multiple levels. Finally, we also discuss potential challenges in future studies of SA signaling pathway.

IBD Systems Biology Is Here to Stay

BACKGROUND

Systems biology is a rapidly advancing field of science that allows us to look into disease mechanisms, patient diagnosis and stratification, and drug development in a completely new light. It is based on the utilization of unbiased computational systems free of the traditional experimental approaches based on personal choices of what is important and what select experiments should be performed to obtain the expected results.

METHODS

Systems biology can be applied to inflammatory bowel disease (IBD) by learning basic concepts of omes and omics and how omics-derived "big data" can be integrated to discover the biological networks underlying highly complex diseases like IBD. Once these biological networks (interactomes) are identified, then the molecules controlling the disease network can be singled out and specific blockers developed.

RESULTS

The field of systems biology in IBD is just emerging, and there is still limited information on how to best utilize its power to advance our understanding of Crohn disease and ulcerative colitis to develop novel therapeutic strategies. Few centers have embraced systems biology in IBD, but the creation of international consortia and large biobanks will make biosamples available to basic and clinical IBD investigators for further research studies.

CONCLUSIONS

The implementation of systems biology is indispensable and unavoidable, and the patient and medical communities will both benefit immensely from what it will offer in the near future.

Gene Expression Correlation Analysis Reveals MYC-NAC Regulatory Network in Cotton Pigment Gland Development

Plant NAC (NAM, ATAF1/2, and CUC2) family is involved in various development processes including Programmed Cell Death (PCD) associated development. However, the relationship between NAC family and PCD-associated cotton pigment gland development is largely unknown. In this study, we identified 150, 153 and 299 NAC genes in newly updated genome sequences of G. arboreum, G. raimondii and G. hirsutum, respectively. All NAC genes were divided into 8 groups by the phylogenetic analysis and most of them were conserved during cotton evolution. Using the vital regulator of gland formation GhMYC2-like as bait, expression correlation analysis screened out 6 NAC genes which were low-expressed in glandless cotton and high-expressed in glanded cotton. These 6 NAC genes acted downstream of GhMYC2-like and were induced by MeJA. Silencing CGF1(Cotton Gland Formation1), another MYC-coding gene, caused almost glandless phenotype and down-regulated expression of GhMYC2-like and the 6 NAC genes, indicating a MYC-NAC regulatory network in gland development. In addition, predicted regulatory mechanism showed that the 6&nbsp;NAC genes were possibly regulated by light, various phytohormones and transcription factors as well as miRNAs. The interaction network and DNA binding sites of the 6 NAC transcription factors were also predicted. These results laid the foundation for further study of gland-related genes and gland development regulatory network.

NEM-Tar: A Probabilistic Graphical Model for Cancer Regulatory Network Inference and Prioritization of Potential Therapeutic Targets From Multi-Omics Data

Targeted therapy has been widely adopted as an effective treatment strategy to battle against cancer. However, cancers are not single disease entities, but comprising multiple molecularly distinct subtypes, and the heterogeneity nature prevents precise selection of patients for optimized therapy. Dissecting cancer subtype-specific signaling pathways is crucial to pinpointing dysregulated genes for the prioritization of novel therapeutic targets. Nested effects models (NEMs) are a group of graphical models that encode subset relations between observed downstream effects under perturbations to upstream signaling genes, providing a prototype for mapping the inner workings of the cell. In this study, we developed NEM-Tar, which extends the original NEMs to predict drug targets by incorporating causal information of (epi)genetic aberrations for signaling pathway inference. An information theory-based score, weighted information gain (WIG), was proposed to assess the impact of signaling genes on a specific downstream biological process of interest. Subsequently, we conducted simulation studies to compare three inference methods and found that the greedy hill-climbing algorithm demonstrated the highest accuracy and robustness to noise. Furthermore, two case studies were conducted using multi-omics data for colorectal cancer (CRC) and gastric cancer (GC) in the TCGA database. Using NEM-Tar, we inferred signaling networks driving the poor-prognosis subtypes of CRC and GC, respectively. Our model prioritized not only potential individual drug targets such as HER2, for which FDA-approved inhibitors are available but also the combinations of multiple targets potentially useful for the design of combination therapies.

Alternative splicing perturbation landscape identifies RNA binding proteins as potential therapeutic targets in cancer

Alternative splicing (AS) plays an important role in gene regulation, and AS perturbations are frequently observed in cancer. RNA binding protein (RBP) is one of the molecular determinants of AS, and perturbations in RBP-gene network activity are causally associated with cancer development. Here, we performed a systematic analysis to characterize the perturbations in AS events across 18 cancer types. We showed that AS alterations were prevalent in cancer and involved in cancer-related pathways. Given that the extent of AS perturbation was associated with disease severity, we proposed a computational pipeline to identify RBP regulators. Pan-cancer analysis identified a number of conserved RBP regulators, which play important roles in regulating AS of genes involved in cancer hallmark pathways. Our application analysis revealed that the expression of 68 RBP regulators helped in cancer subtyping. Specifically, we identified four subtypes of kidney cancer with differences in cancer hallmark pathway activities and prognosis. Finally, we identified the small molecules that can potentially target the RBP genes and suggested potential candidates for cancer therapy. In summary, our comprehensive AS perturbation landscape analysis identified RBPs as potential therapeutic targets in cancer and provided novel insights into the regulatory functions of RBPs in cancer.

P53 long noncoding RNA regulatory network in cancer development

The protein p53 as a transcription factor with strong tumor-suppressive activities is known to trigger apoptosis via multiple pathways and is directly involved in the recognition of DNA damage and DNA repair processes. P53 alteration is now recognized as a common event in the pathogenesis of many types of human malignancies. Deregulation of tumor suppressor p53 pathways plays an important role in the activation of cell proliferation or inactivation of apoptotic cell death during carcinogenesis and tumor progression. Mounting evidence indicates that the p53 status of tumors and also the regulatory functions of p53 may be relevant to the long noncoding RNAs (lncRNA)-dependent gene regulation programs. Besides coding genes, lncRNAs that do not encode for proteins are induced or suppressed by p53 transcriptional response and thus control cancer progression. LncRNAs also have emerged as key regulators that impinge on the p53 signaling network orchestrating global gene-expression profile. Studies have suggested that aberrant expression of lncRNAs as a molecular-genomic signature may play important roles in cancer biology. Accordingly, it is important to elucidate the mechanisms by which the crosstalk between lncRNAs and p53 occurs in the development of numerous cancers. Here, we review how several classes of lncRNAs and p53 pathways are linked together in controlling the cell cycle and apoptosis in various cancer cells in both human and mouse model systems.

Prognostic alternative splicing regulatory network of RBM25 in hepatocellular carcinoma

RNA-binding motif protein 25 (RBM25) is a poorly characterized RNA-binding protein that is involved in several biological processes and regulates the proliferation and metastasis of tumor cells. The regulatory role of RBM25 in hepatocellular carcinoma (HCC) is unknown. Here, RBM25 expression and outcomes in HCC patients were evaluated using The Cancer Genome Atlas database. RBM25 was overexpressed in HCC patients compared with the healthy group. The high expression of RBM25 in tumor tissues was significantly related to poor overall survival (P<0.001). Overexpression of RBM25 significantly contributed to poorer survival in male patients and N0 stage patients (P<0.001). Spearman analysis and weighted gene co-expression network analysis identified 694 RBM25-related genes. Protein-protein interaction network analysis revealed the Cluster with the highest score, which positively correlated with RBM25. CDCA5 and INCENP were identified as the core functional genes related to RBM25. The overexpression of CDCA5 and INCENP in HCC patients was examined using the Human Protein Atlas database. The findings collectively indicated that RBM25 may interact with CDCA5 and INCENP to regulate HCC. Our detailed characterization of RBM25 protein interactions and related core functional genes provides a basis for further studies aimed at identifying molecular regulatory pathways or splicing events.

Integrative Analysis of Gene Expression and miRNAs Reveal Biological Pathways Associated with Bud Paradormancy and Endodormancy in Grapevine

Transition of grapevine buds from paradormancy to endodormancy is coordinated by changes in gene expression, phytohormones, transcription factors, and other molecular regulators, but the mechanisms involved in transcriptional and post-transcriptional regulation of dormancy stages are not well delineated. To identify potential regulatory targets, an integrative analysis of differential gene expression profiles and their inverse relationships with miRNA abundance was performed in paradormant (long day (LD) 15 h) or endodormant (short day (SD), 13 h) Vitis riparia buds. There were 400 up- and 936 downregulated differentially expressed genes in SD relative to LD budsGene set and gene ontology enrichment analysis indicated that hormone signaling and cell cycling genes were downregulated in SD relative to LD buds. miRNA abundance and inverse expression analyses of miRNA target genes indicated increased abundance of miRNAs that negatively regulate genes involved with cell cycle and meristem development in endodormant buds and miRNAs targeting starch metabolism related genes in paradormant buds. Analysis of interactions between abundant miRNAs and transcription factors identified a network with coinciding regulation of cell cycle and epigenetic regulation related genes in SD buds. This network provides evidence for cross regulation occurring between miRNA and transcription factors both upstream and downstream of MYB3R1.

Genome-Wide Analyses of Prognostic and Therapeutic Alternative Splicing Signatures in Bladder Urothelial Carcinoma

Background

Alternative splicing (AS) is an indispensable post-transcriptional modification applied during the maturation of mRNA, and AS defects have been associated with many cancers. This study was designed to thoroughly analyze AS events in bladder urothelial carcinoma (BLCA) at the genome-wide level.

Methods

We adopted a gap analysis to screen for significant differential AS events (DASEs) associated with BLCA. DASEs with prognostic value for OS and the disease-free interval (DFI) were identified by Cox analysis. In addition, a differential AS network and AS clusters were identified using unsupervised cluster analysis. We examined differences in the sensitivity to chemotherapy and immunotherapy between BLCA patients with high and low overall survival (OS) risk.

Results

An extensive number of DASEs (296) were found to be clinically relevant in BLCA. A prognosis model was established based prognostic value of OS and DFI. CUGBP elav-like family member 2 (CELF2) was identified as a hub splicing factor for AS networks. We also identified AS clusters associated with OS using unsupervised cluster analysis, and we predicted that the effects of cisplatin and gemcitabine chemotherapy would be different between high- and low-risk groups based on OS prognosis.

Conclusion

We completed a comprehensive analysis of AS events in BLCA at the genome-wide level. The present findings revealed that DASEs and splicing factors tended to impact BLCA patient survival and sensitivity to chemotherapy drugs, which may provide novel prospects for BLCA therapies.

The Potential Regulatory Network of Glutamate Metabolic Pathway Disturbance in Chinese Han Withdrawal Methamphetamine Abusers

Objects

To explore the long-term influence of methamphetamine abuse on metabolomics character, with gas chromatography-mass spectrometry (GS-MS) technology, and the potential regulatory network using the bioinformatics method.

Methods

Forty withdrawal methamphetamine abusers (WMA) were recruited from Shanghai Gaojing Forced Isolation Detoxification Institute. Forty healthy controls (HC) were recruited from society. GS-MS technology was used to detect metabolic products in serum. A bioinformatics method was used to build a regulatory network. Q-PCR was used to detect the candidate gene expressions, and ELISA was used to detect the regulatory enzyme expressions.

Results

Four pathways were significantly changed in the MA compared to the HC: (1) the arginine synthesis pathway, (2) alanine, aspartic acid and glutamate metabolic pathway, (3) cysteine and methionine metabolic pathway, and (4) the ascorbate and aldarate pathway (enrichment analysis p < 0.05, Impactor factor > 0.2). When focusing on the ‘Alanine, aspartate, and glutamate metabolism’ pathway, a regulatory network was established, and the expression of candidate regulatory genes and enzymes was verified. It was found that the expression of DLG2 (Discs large MAGUK scaffold protein 2), PLA2G4 (Phospholipase A2 group IVE), PDE4D (Phosphodiesterase 4D), PDE4B (Phosphodiesterase 4B), and EPHB2 (Ephrin type-B receptor 2) were significantly different between the two groups (p < 0.05), However, after adjusting for age and BMI, only DLG2, PLA2G4, and EPHB2 remained significant (p < 0.05). The expression of enzymes was not significantly different (p > 0.05).

Conclusion

Methamphetamine abuse influences the metabolic process in the long term, and DLG2, PLA2G4, and EPHB2 may regulate the glutamate metabolism pathway.

The WRKY transcription factor AaGSW2 promotes glandular trichome initiation in Artemisia annua

Glandular secreting trichomes (GSTs) synthesize and secrete large quantities of secondary metabolites, some of which have well-established commercial value. An example is the anti-malarial compound artemisinin, which is synthesized in the GSTs of Artemisia annua. Accordingly, there is considerable interest in understanding the processes that regulate GST density as a strategy to increase artemisinin production. In this study, we identified a GST-specific WRKY transcription factor from A. annua, AaGSW2, which is positively regulated by the direct binding of the homeodomain proteins AaHD1 and AaHD8 to the L1-box of the AaGSW2 promoter. Overexpression of AaGSW2 in A. annua significantly increased GST density, while AaGSW2 knockdown lines showed impaired GST initiation. Ectopic expression of AaGSW2 homologs from two mint cultivars, Mentha spicata and Mentha haplocalyx, in A. annua also induced GST formation. These results reveal a molecular mechanism involving homeodomain and WRKY proteins that controls glandular trichome initiation, at least part of which is shared by A. annua and mint.

Analysis and Validation of circRNA-miRNA Network in Regulating m6A RNA Methylation Modulators Reveals CircMAP2K4/miR-139-5p/YTHDF1 Axis Involving the Proliferation of Hepatocellular Carcinoma

The m⁶A RNA methylation modulators play a crucial role in regulating hepatocellular carcinoma (HCC) progression. The circular RNA (circRNA) regulatory network in regulating m⁶A RNA methylation modulators in HCC remains largely unknown. In this study, 5 prognostic m⁶A RNA methylation modulators in HCC were identified from The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) projects. The differentially expressed microRNAs (DEmiRNAs) and circRNAs (DEcircRNAs) between paired tumor and normal tissues were screened out from TCGA and or Gene Expression Omnibus (GEO) database to construct the circRNA-miRNA- m⁶A RNA methylation modulator regulatory network, which included three m⁶A RNA methylation modulators (HNRNPC, YTHDF1, and YTHDF2), 11 DEmiRNAs, and eight DEcircRNAs. Among the network, hsa-miR-139-5p expression was negatively correlated with YTHDF1. Hsa-miR-139-5p low or YTHDF1 high expression was correlated with high pathological grade, advanced stage and poor survival of HCC. Additionally, cell cycle, base excision repair, and homologous recombination were enriched in YTHDF1 high expression group by GSEA. A hub circRNA regulatory network was constructed based on hsa-miR-139-5p/YTHDF1 axis. Furthermore, hsa_circ_0007456(circMAP2K4) was validated to promote HCC cell proliferation by binding with hsa-miR-139-5p to promote YTHDF1 expression. Taken together, we identified certain circRNA regulatory network related to m⁶A RNA methylation modulators and provided clues for mechanism study and therapeutic targets for HCC.

Bioinformatics Analysis of Key micro-RNAs and mRNAs under the Hand, Foot, and Mouth Disease Virus Infection

To clarify crucial key micro-RNAs and mRNAs associated with hand, foot, and mouth disease (HFMD) virus infection, we conducted this bioinformatics analysis from four GEO datasets. The following datasets were used for the analysis: GSE85829, GSE94551, GSE52780, and GSE45589. Differentially expressed genes (DEGs) were acquired, and the analysis of functional and pathway enrichment and the relative regulatory network were conducted. After screening common differentially expressed miRNAs (DE-miRNAs), five key miRNAs were acquired: miR-100-3p, miR-125a-3p, miR-1273g-3p, miR-5585-3p, and miR-671-5p. There were three common enriched GO terms between miRNA-derived prediction and mRNA-derived analysis: biosynthetic process, cytosol, and nucleoplasm. There was one common KEGG pathway, i.e., cell cycle shared between miRNA-based and mRNA-based enrichment. Using TarBase V8 in DIANA tools, we acquired 1,520 potential targets (mRNA) from the five key DE-miRNAs, among which the159 DE-mRNAs also included 11 DEGs. These common DEGs showed a PPI network mainly connected by SMC1A, SMARCC1, SF3B3, LIG1, and BRMS1L. Together, changes in five key miRNAs and 11 key mRNAs may play crucial roles in HFMD progression. A combination of these roles may benefit the early diagnosis and treatment of HFMD.

Abiotic Stress-Responsive miRNA and Transcription Factor-Mediated Gene Regulatory Network in Oryza sativa: Construction and Structural Measure Study

Climate changes and environmental stresses have a consequential association with crop plant growth and yield, meaning it is necessary to cultivate crops that have tolerance toward the changing climate and environmental disturbances such as water stress, temperature fluctuation, and salt toxicity. Recent studies have shown that trans-acting regulatory elements, including microRNAs (miRNAs) and transcription factors (TFs), are emerging as promising tools for engineering naive improved crop varieties with tolerance for multiple environmental stresses and enhanced quality as well as yield. However, the interwoven complex regulatory function of TFs and miRNAs at transcriptional and post-transcriptional levels is unexplored in Oryza sativa. To this end, we have constructed a multiple abiotic stress responsive TF-miRNA-gene regulatory network for O. sativa using a transcriptome and degradome sequencing data meta-analysis approach. The theoretical network approach has shown the networks to be dense, scale-free, and small-world, which makes the network stable. They are also invariant to scale change where an efficient, quick transmission of biological signals occurs within the network on extrinsic hindrance. The analysis also deciphered the existence of communities (cluster of TF, miRNA, and genes) working together to help plants in acclimatizing to multiple stresses. It highlighted that genes, TFs, and miRNAs shared by multiple stress conditions that work as hubs or bottlenecks for signal propagation, for example, during the interaction between stress-responsive genes (TFs/miRNAs/other genes) and genes involved in floral development pathways under multiple environmental stresses. This study further highlights how the fine-tuning feedback mechanism works for balancing stress tolerance and how timely flowering enable crops to survive in adverse conditions. This study developed the abiotic stress-responsive regulatory network, APRegNet database (http://lms.snu.edu.in/APRegNet), which may help researchers studying the roles of miRNAs and TFs. Furthermore, it advances current understanding of multiple abiotic stress tolerance mechanisms.

Portrait of Cancer Stem Cells on Colorectal Cancer: Molecular Biomarkers, Signaling Pathways and miRNAome

Colorectal cancer (CRC) is a leading cause of cancer death worldwide, and about 20% is metastatic at diagnosis and untreatable. Increasing evidence suggests that the heterogeneous nature of CRC is related to colorectal cancer stem cells (CCSCs), a small cells population with stemness behaviors and responsible for tumor progression, recurrence, and therapy resistance. Growing knowledge of stem cells (SCs) biology has rapidly improved uncovering the molecular mechanisms and possible crosstalk/feedback loops between signaling pathways that directly influence intestinal homeostasis and tumorigenesis. The generation of CCSCs is probably connected to genetic changes in members of signaling pathways, which control self-renewal and pluripotency in SCs and then establish function and phenotype of CCSCs. Particularly, various deregulated CCSC-related miRNAs have been reported to modulate stemness features, controlling CCSCs functions such as regulation of cell cycle genes expression, epithelial-mesenchymal transition, metastasization, and drug-resistance mechanisms. Primarily, CCSC-related miRNAs work by regulating mainly signal pathways known to be involved in CCSCs biology. This review intends to summarize the epigenetic findings linked to miRNAome in the maintenance and regulation of CCSCs, including their relationships with different signaling pathways, which should help to identify specific diagnostic, prognostic, and predictive biomarkers for CRC, but also develop innovative CCSCs-targeted therapies.

Screening of Therapeutic Candidate Genes of Quercetin for Cervical Cancer and Analysis of Their Regulatory Network

Purpose

To explore the therapeutic targets and regulatory mechanisms of the antitumor drug quercetin in the treatment of cervical cancer.

Methods

Cervical cancer (HeLa) cells were treated with quercetin and subjected to RNA sequencing using the BGISEQ-500 platform. By combined analysis of GEO database and RNA-seq results, the differentially expressed genes (DEGs) (namely, the genes in the GEO database that were upregulated/downregulated in cervical cancer compared with normal cervix and downregulated/upregulated after quercetin treatment) were identified. Functional enrichment and protein–protein interaction analyses were carried out for the DEGs. The candidate genes were identified using the Gentiscape2.2 and MCODE plug-ins for Cytoscape software, and the upstream miRNAs, lncRNAs, and circRNAs of the candidate genes were predicted using the online tools MirDIP, TarBase, and ENCORI. Finally, the regulatory network was constructed using Cytoscape software.

Results

Quercetin significantly inhibited the proliferation of cervical cancer cells. The combined analyses of the GEO database and RNA-seq results obtained 74 DEGs, and the functional enrichment analysis of the DEGs identified 861 biological processes, 32 cellular components, 50 molecular functions, and 56 KEGG pathways. Five therapeutic candidate genes, including EGFR, JUN, AR, CD44, and MUC1, were selected, and 10 miRNAs, 1 lncRNA, and 71 circRNAs upstream of these genes were identified. Finally, a lncRNA/circRNA-miRNA-mRNA-pathway regulatory network was constructed.

Conclusion

In this study, data mining was used to identify candidate genes and their regulatory network for the treatment of cervical cancer to provide a theoretical basis for targeted therapy of cervical cancer.

Transcriptomic analysis reveals the regulation network of BmKrüppel homolog 1 in the oocyte development of Bombyx mori

Krüppel homolog 1 (Kr-h1), a zinc finger transcription factor, is involved in the metamorphosis and adult reproduction of insects. However, the role of Kr-h1 in reproduction of holometabolic insects remains to be elucidated. The regulation network of Kr-h1-associated genes in the reproduction in Bombyx mori was investigated in this study. The higher expression level of BmKr-h1 in the ovaries was detected during the late pupal stage and adults. RNA interference (RNAi)-mediated depletion of BmKr-h1 in the female at day 6 of pupae resulted in abnormal oocytes at 48 h post-double-stranded RNA treatment, which showed less yolk protein deposition and partially transparent chorion. RNA-seq and subsequent differentially expressed transcripts analysis showed that knockdown of BmKr-h1 caused a decrease in the expression of 2882 genes and an increase in the expression of 2565 genes in the oocytes at day 8 of pupae. Totally, 27 genes coding for transcription factors were down-regulated, while six genes coding for other transcription factors were up-regulated. BmKr-h1 bound to the Kr-h1 binding site of the transcription factors AP-1 (activating protein-1) and FOXG1 to increase their messenger RNA transcripts in the BmN cells, respectively. Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analyses of that positively co-expressed with AP-1 and FOXG1 transcripts showed mainly enrichment in the metabolic-related pathways, the nutrient absorption and the yolk protein absorption processes. These data suggested that BmKr-h1 might directly regulate the metabolic-related pathways, the nutrient absorption and the yolk protein absorption processes or probably through AP-1 and /or FOXG1 to regulate oocyte development.

The land plant-specific MIXTA-MYB lineage is implicated in the early evolution of the plant cuticle and the colonization of land

The evolution of a lipid-based cuticle on aerial plant surfaces that protects against dehydration is considered a fundamental innovation in the colonization of the land by the green plants. However, key evolutionary steps in the early regulation of cuticle synthesis are still poorly understood, owing to limited studies in early-diverging land plant lineages. Here, we characterize a land plant specific subgroup 9 R2R3 MYB transcription factor MpSBG9, in the early-diverging land plant model Marchantia polymorpha, that is homologous to MIXTA proteins in vascular plants. The MpSBG9 functions as a key regulator of cuticle biosynthesis by preferentially regulating expression of orthologous genes for cutin formation, but not wax biosynthesis genes. The MpSBG9 also promotes the formation of papillate cells on the adaxial surface of M. polymorpha, which is consisitent with its canonical role in vascular plants. Our observations imply conserved MYB transcriptional regulation in the control of the cutin biosynthesis pathway as a core genetic network in the common ancestor of all land plants, implicating the land plant-specific MIXTA MYB lineage in the early origin and evolution of the cuticle.

Generating Ensembles of Gene Regulatory Networks to Assess Robustness of Disease Modules

The use of biological networks such as protein-protein interaction and transcriptional regulatory networks is becoming an integral part of genomics research. However, these networks are not static, and during phenotypic transitions like disease onset, they can acquire new "communities" (or highly interacting groups) of genes that carry out cellular processes. Disease communities can be detected by maximizing a modularity-based score, but since biological systems and network inference algorithms are inherently noisy, it remains a challenge to determine whether these changes represent real cellular responses or whether they appeared by random chance. Here, we introduce Constrained Random Alteration of Network Edges (CRANE), a method for randomizing networks with fixed node strengths. CRANE can be used to generate a null distribution of gene regulatory networks that can in turn be used to rank the most significant changes in candidate disease communities. Compared to other approaches, such as consensus clustering or commonly used generative models, CRANE emulates biologically realistic networks and recovers simulated disease modules with higher accuracy. When applied to breast and ovarian cancer networks, CRANE improves the identification of cancer-relevant GO terms while reducing the signal from non-specific housekeeping processes.