Comparative Transcriptomic and Proteomic Analysis of Exopalaemon carinicauda in Response to Alkalinity Stress

Saline-alkaline waters are stressful environments where most aquatic animals can’t survive normally, and alkalinity is one of the key limited environmental factors. Due to strong adaptability to environment, the ridgetail white prawn Exopalaemon carinicauda is a potential good species suitable for large-scale culture in saline-alkaline waters. Exploring its alkaline adaptability mechanism will help to guide more marine crustaceans to saline-alkaline culture. In this study, an integrative analysis of the gill-specific transcriptome and proteome at 0, 12, and 36 h after alkalinity stress was performed to identify important regulators and pathways involved in alkalinity adaption of E. carinicauda. A total of 3,157 differentially expressed genes (DEGs) and 443 differentially expressed proteins (DEPs) were identified at 12 and 36 h compared with 0 h. Base on the transcriptome analysis, the Gene Ontology (GO) enriched terms were mainly related to ion transport, including “calcium-transporting ATPase activity,” “ATPase coupled ion transmembrane transporter activity,” “divalent inorganic cation transmembrane transporter activity,” etc., and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways mainly refer to the processes of endocrine system at both 12, and 36 h. Based on the proteomic analysis, KEGG pathways related to lipolysis and amino acids metabolism were significantly enriched at 12 h, and carbohydrate metabolism and immune response were significantly enriched at 36 h. There were significantly up-regulated expressions of ion transport related genes including aquaporin, carbonic anhydrase, ammonium transporter Rh type A-like, Na+/H+-exchanger, etc., as well as ion transport proteins including V-type proton ATPase 116 kDa subunit a-like isoform X1, sodium-potassium ATPase beta, vesicle associated membrane protein, etc. after alkalinity exposure, which indicating their important roles in response to alkalinity stress. The results of integrated analysis between proteome and transcriptome showed that up-regulated DEG/DEP (aldehyde dehydrogenase) was significantly enriched at 12 h and the up-regulated DEG/DEP (peptidylglycine alpha) was significantly enriched at 36 h, suggesting the two molecules may be critical in response to alkalinity change. This study reveals the first time-course, gill-specific, combined transcriptomic and proteomic profiling associated with alkalinity adaption of E. carinicauda and provides new insights into the mechanisms underlying the molecular response to alkalinity stress in shrimp.

Loss-of-function mutations in the histone methyltransferase EZH2 promote chemotherapy resistance in AML

Chemotherapy resistance is the main impediment in the treatment of acute myeloid leukaemia (AML). Despite rapid advances, the various mechanisms inducing resistance development remain to be defined in detail. Here we report that loss-of-function mutations (LOF) in the histone methyltransferase EZH2 have the potential to confer resistance against the chemotherapeutic agent cytarabine. We identify seven distinct EZH2 mutations leading to loss of H3K27 trimethylation via multiple mechanisms. Analysis of matched diagnosis and relapse samples reveal a heterogenous regulation of EZH2 and a loss of EZH2 in 50% of patients. We confirm that loss of EZH2 induces resistance against cytarabine in the cell lines HEK293T and K562 as well as in a patient-derived xenograft model. Proteomics and transcriptomics analysis reveal that resistance is conferred by upregulation of multiple direct and indirect EZH2 target genes that are involved in apoptosis evasion, augmentation of proliferation and alteration of transmembrane transporter function. Our data indicate that loss of EZH2 results in upregulation of its target genes, providing the cell with a selective growth advantage, which mediates chemotherapy resistance.

Construction of a ceRNA network combining transcription factors in eutopic endometrial tissue of tubal factor infertility and endometriosis-related infertility

Purpose Although tubal factor infertility (TFI) and endometriosis-related infertility all can result in female infertility, the pathogenesis of TFI and endometriosis-related infertility were different. The pathophysiologic mechanisms of TFI and endometriosis-related infertility have not been investigated thoroughly. Thus, the aim of the study is to identify the potential crucial genes, pathways, transcription factors (TFs) and long non-coding RNAs (lncRNAs) associated with TFI and endometriosis-related infertility, and further analyze the molecular mechanism implicated in genes.Methods 3 patients with TFI and 3 patients with endometriosis-related infertility were recruited, and microarray hybridization of the eutopic endometrial tissue during the window of implantation (WOI) was performed to examine the expression of mRNAs and lncRNAs. First, differentially expressed genes (DEGs) and differentially expressed lncRNAs (DELs) were screened out based on P < 0.05 and fold change (FC) ≧ 2. Second, gene ontology, pathway and TFs enrichment analyses and PPI network construction of DEGs were performed. Then, important modules and Hub genes of PPI network were further analysed and a ceRNA network combining TFs based on DEGs and DELs was constructed. Finally, we selected the lapping genes of the important modules, Hub genes and the ceRNA network as potential key genes associated with TFI and endometriosis-related infertility and constructed a new ceRNA network on the base of potential key genes.Results 508 DEGs and 576 DELs were screened out. The gene ontology and pathway of DEGs were mainly enriched in transmembrane transporter activity and the immune system (eg, passive transmembrane transporter activity, Intestinal immune network for IgA production and so on). In addition, a ceRNA network (based on potential key genes) combining TFs including 2 mRNAs (PLAU and LDLR), 5 miRNAs (hsa-miR-301b-3p, hsa-miR-27a-3p, hsa-miR-20b-5p, hsa-miR-193a-3p and hsa-miR-17-5p), 8 lncRNAs (eg. LMO7-AS1, ITFG3 and MGST1, etc.) and 10 TFs (eg. SRF, FOX, which target to mRNA and eg. POU3F2, HNF1A, which target to miRNA) was successfully built.Conclusions In conclusion, pathophysiologic mechanisms of TFI and endometriosis related infertility may be related to the transmembrane transporter activity and the immune system. These potential key RNAs and TFs might have clinical utility for the diagnosis and prognosis prediction in TFI and endometriosis-related infertility. The results of the current study might lay the foundation for future basic and clinical research.

Gene-Specific Predictability of Protein Levels from mRNA Data in Humans

Transcriptomic data are widely available, and the extent to which they are predictive of protein abundances remains debated. Using multiple public databases, we calculate mRNA and mRNA-to-protein ratio variability across human tissues to quantify and classify genes for protein abundance predictability confidence. We propose that such predictability is best understood as a spectrum. A gene-specific, tissue-independent mRNA-to-protein ratio plus mRNA levels explains ∼80% of protein abundance variance for more predictable genes, as compared to ∼55% for less predictable genes. Protein abundance predictability is consistent with independent mRNA and protein data from two disparate cell lines, and mRNA-to-protein ratios estimated from publicly-available databases have predictive power in these independent datasets. Genes with higher predictability are enriched for metabolic function, tissue development/cell differentiation roles, and transmembrane transporter activity. Genes with lower predictability are associated with cell adhesion, motility and organization, the immune system, and the cytoskeleton. Surprisingly, many genes that regulate mRNA-to-protein ratios are constitutively expressed but also exhibit ratio variability, suggesting a general autoregulation mechanism whereby protein expression profile changes can be implemented quickly, or homeostatic sensing stabilizes protein abundances under fluctuating conditions. Gene classifications and their mRNA-to-protein ratios are provided as a resource to facilitate protein abundance predictions by others.

Putative transmembrane transporter modulates higher-level aggression in Drosophila

By selection of winners of dyadic fights for 35 generations, we have generated a hyperaggressive Bully line of flies that almost always win fights against the parental wild-type Canton-S stock. Maintenance of the Bully phenotype is temperature dependent during development, with the phenotype lost when flies are reared at 19 °C. No similar effect is seen with the parent line. This difference allowed us to carry out RNA-seq experiments and identify a limited number of genes that are differentially expressed by twofold or greater in the Bullies; one of these was a putative transmembrane transporter, CG13646, which showed consistent and reproducible twofold down-regulation in Bullies. We examined the causal effect of this gene on the phenotype with a mutant line for CG13646, and with an RNAi approach. In all cases, reduction in expression of CG13646 by approximately half led to a hyperaggressive phenotype partially resembling that seen in the Bully flies. This gene is a member of a very interesting family of solute carrier proteins (SLCs), some of which have been suggested as being involved in glutamine/glutamate and GABA cycles of metabolism in excitatory and inhibitory nerve terminals in mammalian systems.