Gene Transcription In Response Research Articles

CDK12/13: A Promising New Therapeutic Target in ALL

Acute lymphoblastic leukemia (ALL) is an aggressive hematologic malignancy in children and young adults. Upfront resistance to glucocorticoids used as first-line treatment in most regimens confers a poor prognosis for patients with ALL. Of patients who relapse, only half achieve long-term survival. Here we demonstrate that inhibition of cyclin dependant kinases 12 and 13 (CDK12 & CDK13), which are modulators of RNA polymerase II, has a robust synergistic anti-leukemia effect with dexamethasone, in both B-ALL and T-ALL cell lines as well as primary B-ALL patient-derived bone marrow samples. To understand the mechanism underlying the steroid resistance in ALL, we first reanalyzed shRNA screen performed by Poulard et al. This revealed that CDK13 silencing sensitized leukemic cells to dexamethasone. CDK12 is located on chromosome 17q12, containing oncogenic features and genetic alterations in various tumors. CDK12/13 inhibitor exhibits efficacy against an Ewing sarcoma tumor growth in a patient-derived xenograft mouse model. It was shown that the inhibition resensitizes HER2+ breast cancers to HER2-tyrosine kinase inhibitors via suppressing PI3K/AKT in patient-derived organoids in vitro and cell-derived xenograft or patient-derived xenograft in vivo. Forgoing research demonstrates that CDK12/13 inhibition silences transcription of DNA damage response (DDR) genes. In our study, however, we haven't observed a rise in γH2AX, a marker of DNA damage, after CDK12/13 inhibition in ALL cell lines. What we did note was a marked enhancement expression of BIM and SGK1, steroid responsive genes and pro-apoptotic factors, after CDK12/13 inhibition (Figure A). ALL cell lines exhibited high susceptibility to CDK12/13 inhibition with two chemically divergent inhibitors, SR-4835 and THZ-531. We also showcased their synergistic interactions with dexamethasone using flow cytometry and synergyfinder ZIP score analysis (Figure B). Moreover, in the GSEA comparison of ALL cell lines with and without synergy between CDK12/13 inhibitors and dexamethasone, our data underscored significant enrichment in cholesterol biosynthesis-related genesets in cell lines manifesting this synergistic effect. On the other hand, we observed resistance to SR-4835 in cell lines with high enrichment scores in NOTCH, a signaling pathway implicated in about 80% of relapsed T cell ALL/LBL cases. Additionally, new data on mice xenotransplanted with B-ALL CNS-derived patient cells, link upregulated cholesterol biosynthetic pathways to nervous system involvement in childhood ALL. Upon administering CDK12/13 inhibitors, we observed a cell cycle phase shift resulting in G1 arrest and increased apoptosis, whereas human peripheral blood mononuclear cells (PBMCs) from healthy individuals remained unaffected by this treatment. As we continue to decode the pathways through which CDK12/13 inhibitors render ALL cells more susceptible to dexamethasone, our next step includes silencing CDK12/13 using short hairpin RNA models in cell lines and consequently their RNA sequencing. This approach may mitigate the influence of secondary pathways, paving the way for enhanced treatment strategies for relapsed ALL by unmasking the underlying molecular events.

RNF2 regulates Wnt/ß-catenin signaling via TCF7L1 destabilization

The Wnt signaling pathway is a crucial regulator of various biological processes, such as development and cancer. The downstream transcription factors in this pathway play a vital role in determining the threshold for signaling induction and the length of the response, which vary depending on the biological context. Among the four transcription factors involved in canonical Wnt/ß-catenin signaling, TCF7L1 is known to possess an inhibitory function; however, the underlying regulatory mechanism remains unclear. In this study, we identified the E3 ligase, RNF2, as a novel positive regulator of the Wnt pathway. Here, we demonstrate that RNF2 promotes the degradation of TCF7L1 through its ubiquitination upon activation of Wnt signaling. Loss-of-function studies have shown that RNF2 consistently destabilizes nuclear TCF7L1 and is required for proper Wnt target gene transcription in response to Wnt activation. Furthermore, our results revealed that RNF2 controls the threshold, persistence, and termination of Wnt signaling by regulating TCF7L1. Overall, our study sheds light on the previously unknown degradation mechanism of TCF7L1 by a specific E3 ligase, RNF2, and provides new insights into the variability in cellular responses to Wnt activation.

Identification of prognostic biomarkers for antibiotic associated nephrotoxicity in cystic fibrosis

BackgroundOur objective was to discover novel urinary biomarkers of antibiotic-associated nephrotoxicity using an ex-vivo human microphysiological system (MPS) and to translate these findings to a prospectively enrolled cystic fibrosis (CF) population receiving aminoglycosides and/or polymyxin E (colistin) for a pulmonary exacerbation. MethodsWe populated the MPS with primary human kidney proximal tubule epithelial cells (PTECs) from three donors and modeled nephrotoxin injury through exposure to 50 µg/mL polymyxin E for 72 h. We analyzed gene transcriptional responses by RNAseq and tested MPS effluents. We translated candidate biomarkers to a CF cohort via analysis of urine collected prior to, during and two weeks after antibiotics and patients were followed for a median of 3 years after antibiotic use. ResultsPolymyxin E treatment resulted in a statistically significant increase in the pro-apoptotic Fas gene relative to control in RNAseq of MPS: fold-change = 1.63, FDR q-value = 7.29 × 10−5. Effluent analysis demonstrated an acute rise of soluble Fas (sFas) concentrations that correlated with cellular injury. In 16 patients with CF, urinary sFas concentrations were significantly elevated during antibiotic treatment, regardless of development of AKI. Over a median of three years of follow up, we identified seven cases of incident chronic kidney disease (CKD). Urinary sFas concentrations during antibiotic treatment were significantly associated with subsequent development of incident CKD (unadjusted relative risk = 2.02 per doubling of urinary sFas, 95 % CI = 1.40, 2.90, p < 0.001). ConclusionsUsing an ex-vivo MPS, we identified a novel biomarker of proximal tubule epithelial cell injury, sFas, and translated these findings to a clinical cohort of patients with CF.

Constitutive activation of ABA receptors in Arabidopsis reveals unique regulatory circuitries.

Abscisic acid (ABA) is best known for regulating the responses to abiotic stressors. Thus, applications of ABA signaling pathways are considered promising targets for securing yield under stress. ABA levels rise in response to abiotic stress, mounting physiological and metabolic responses that promote plant survival under unfavorable conditions. ABA elicits its effects by binding to a family of soluble receptors found in monomeric and dimeric states, differing in their affinity to ABA and co-receptors. However, the in vivo significance of the biochemical differences between these receptors remains unclear. We took a gain-of-function approach to study receptor-specific functionality. First, we introduced activating mutations that enforce active ABA-bound receptor conformation. We then transformed Arabidopsis ABA-deficient mutants with the constitutive receptors and monitored suppression of the ABA deficiency phenotype. Our findings suggest that PYL4 and PYL5, monomeric ABA receptors, have differential activity in regulating transpiration and transcription of ABA biosynthesis and stress response genes. Through genetic and metabolic data, we demonstrate that PYR1, but not PYL5, is sufficient to activate the ABA positive feedback mechanism. We propose that ABA signaling - from perception to response - flows differently when triggered by different PYLs, due to tissue and transcription barriers, thus resulting in distinct circuitries.

Small but powerful: The role of HSP in bacterial infectious disease pathogenesis- A mini-review of recent findings

Heat Shock Proteins (Hsp) are evolutionarily conserved ubiquitous molecular chaperones usually produced when cells are exposed to temperatures beyond their normal growth temperature. They are a group of ATP-independent chaperons pivotal for cell survival and proliferation. This group of proteins has been well studied over the years. However, recent investigations leveraging the available Whole Genome Sequencing (WGS) approach are beginning to shed more light on how this protein interacts with other intracellular proteins to modulate bacterial virulence and pathogenesis. Bacteria cells that manufacture HSPs can survive at higher temperatures. Certain heat-shock proteins have a refolding or degradation action that can save the bacterial cell even in extreme stress demands and even help some bacteria transition from being commensal to a pathogen. Certain HSPs are virulence factors, while others modulate bacterial pathogenesis increasing bacterial resistance to host immunological attack. Interestingly, others also influence certain virulence gene expressions. Several mechanisms govern heat shock response. Moreover, the employment of specific regulatory proteins that exert a positive or negative effect on the initiation of transcription by the RNA polymerase enzyme is successful and efficient in controlling heat-shock gene transcription. Interestingly, most pathogens use several approaches to reprogram gene transcription in response to diverse stress rapidly. In this mini-review, we tactfully discussed the recent update on HSP in bacteria virulence and how these proteins could serve as potential drug targets. Moreover, we provided an overview of how HSPs are regulated in bacterial pathogens favouring bacterial survival in diverse cellular niches.

Membrane-proximal motifs encode differences in signaling strength between type I and III interferon receptors.

Interferons (IFNs) play crucial roles in antiviral defenses. Despite using the same Janus-activated kinase (JAK)-signal transducer and activator of transcription (STAT) signaling cascade, type I and III IFN receptors differ in the magnitude and dynamics of their signaling in terms of STAT phosphorylation, gene transcription, and antiviral responses. These differences are not due to ligand-binding affinity and receptor abundance. Here, we investigated the ability of the intracellular domains (ICDs) of IFN receptors to differentiate between type I and III IFN signaling. We engineered synthetic, heterodimeric type I and III IFN receptors that were stably expressed at similar amounts in human cells and responded to a common ligand. We found that our synthetic type I IFN receptors stimulated STAT phosphorylation and gene expression to greater extents than did the corresponding type III IFN receptors. Furthermore, we identified short "box motifs" within ICDs that bind to JAK1 that were sufficient to encode differences between the type I and III IFN receptors. Together, our results indicate that specific regions within the ICDs of IFN receptor subunits encode different downstream signaling strengths that enable type I and III IFN receptors to produce distinct signaling outcomes.

The Androgen Receptor Does Not Directly Regulate the Transcription of DNA Damage Response Genes.

Our data indicate that the clinical benefit of combining ADT with RT is not due to direct AR regulation of DDR gene transcription, and that the field needs to consider alternative mechanisms for this clinical benefit.

Milk fat globule membrane protects Bifidobacterium longum ssp. infantis ATCC 15697 against bile stress by modifying global transcriptional responses

The milk fat globule membrane (MFGM) can protect probiotic bacteria from bile stress. However, its potential mechanism has not been reported. In this study, the viability, morphology and gene transcriptional response of Bifidobacterium longum ssp. infantis ATCC 15697 (BI_15697) stressed by bile salts with or without MFGM were investigated. It was shown that MFGM alleviated the reduction in BI_15697 population induced by 0.2% porcine bile stress and restored the population to the control levels. MFGM ameliorated the shrunken, fragmented appearance and irregular morphology of BI_15697 and maintained cell integrity disrupted by bile stress. RNA-sequencing results showed that MFGM increased transport of glucose and raffinose and decreased that of branched-chain amino acids (BCAA) in the presence of bile salts. MFGM stimulated the expression of genes involved in the synthesis of raffinose in galactose metabolism and the metabolism of BCAA, suggesting that MFGM stimulated the accumulation of raffinose and BCAA in the presence of bile. In addition, MFGM stimulated the expression of 2 bile efflux transporters under bile stress. Together, the multifactorial response helps BI_15697 excrete bile salts and maintain cellular integrity in response to bile stress. This study proposes a mechanism for the protection of BI_15697 against bile salt stress by MFGM, thereby providing a molecular basis for its application in incorporation of probiotics.

Nucleoside diphosphate kinases 1 and 2 regulate a protective liver response to a high-fat diet.

The synthesis of fatty acids from acetyl-coenzyme A (AcCoA) is deregulated in diverse pathologies, including cancer. Here, we report that fatty acid accumulation is negatively regulated by nucleoside diphosphate kinases 1 and 2 (NME1/2), housekeeping enzymes involved in nucleotide homeostasis that were recently found to bind CoA. We show that NME1 additionally binds AcCoA and that ligand recognition involves a unique binding mode dependent on the CoA/AcCoA 3' phosphate. We report that Nme2 knockout mice fed a high-fat diet (HFD) exhibit excessive triglyceride synthesis and liver steatosis. In liver cells, NME2 mediates a gene transcriptional response to HFD leading to the repression of fatty acid accumulation and activation of a protective gene expression program via targeted histone acetylation. Our findings implicate NME1/2 in the epigenetic regulation of a protective liver response to HFD and suggest a potential role in controlling AcCoA usage between the competing paths of histone acetylation and fatty acid synthesis.

Cellular Stress: Modulator of Regulated Cell Death.

Cellular stress response activates a complex program of an adaptive response called integrated stress response (ISR) that can allow a cell to survive in the presence of stressors. ISR reprograms gene expression to increase the transcription and translation of stress response genes while repressing the translation of most proteins to reduce the metabolic burden. In some cases, ISR activation can lead to the assembly of a cytoplasmic membraneless compartment called stress granules (SGs). ISR and SGs can inhibit apoptosis, pyroptosis, and necroptosis, suggesting that they guard against uncontrolled regulated cell death (RCD) to promote organismal homeostasis. However, ISR and SGs also allow cancer cells to survive in stressful environments, including hypoxia and during chemotherapy. Therefore, there is a great need to understand the molecular mechanism of the crosstalk between ISR and RCD. This is an active area of research and is expected to be relevant to a range of human diseases. In this review, we provided an overview of the interplay between different cellular stress responses and RCD pathways and their modulation in health and disease.

Host Derivation of Sindbis Virus Influences Mammalian Type I Interferon Response to Infection.

Arboviruses are defined by their ability to replicate in both mosquito vectors and mammalian hosts. There is good evidence that arboviruses "prime" their progeny for infection of the next host, such as via differential glycosylation of their outer glycoproteins or packaging of host ribosomal subunits. We and others have previously shown that mosquito-derived viruses more efficiently infect mammalian cells than mammalian-derived viruses. These observations are consistent with arboviruses acquiring host-specific adaptations, and we hypothesized that a virus derived from either the mammalian host or mosquito vector elicits different responses when infecting the mammalian host. Here, we perform an RNA-sequencing analysis of the transcriptional response of Human Embryonic Kidney 293 (HEK-293) cells to infection with either mosquito (Aedes albopictus, C7/10)- or mammalian (Baby Hamster Kidney, BHK-21)-derived Sindbis virus (SINV). We show that the C7/10-derived virus infection leads to a more robust transcriptional response in HEK-293s compared to infection with the BHK-derived virus. Surprisingly, despite more efficient infection, we found an increase in interferon-β (IFN-β) and interferon-stimulated gene (ISG) transcripts in response to the C7/10-derived virus infection versus the BHK-derived virus infection. However, translation of interferon-stimulated genes was lower in HEK-293s infected with the C7/10-derived virus, starkly contrasting with the transcriptional response. This inhibition of ISG translation is reflective of a more rapid overall shut-off of host cell translation following infection with the C7/10-derived virus. Finally, we show that the C7/10-derived virus infection of HEK-293 cells leads to elevated levels of phosphorylated eukaryotic translation elongation factor-2 (eEF2), identifying a potential mechanism leading to the more rapid shut-off of host translation. We postulate that the rapid shut-off of host translation in mammalian cells infected with the mosquito-derived virus acts to counter the IFN-β-stimulated transcriptional response.

Structural insights into redox signal transduction mechanisms in the control of nitrogen fixation by the NifLA system

NifL is a conformationally dynamic flavoprotein responsible for regulating the activity of the σ54-dependent activator NifA to control the transcription of nitrogen fixation (nif) genes in response to intracellular oxygen, cellular energy, or nitrogen availability. The NifL-NifA two-component system is the master regulatory system for nitrogen fixation. NifL serves as a sensory protein, undergoing signal-dependent conformational changes that modulate its interaction with NifA, forming the NifL-NifA complex, which inhibits NifA activity in conditions unsuitable for nitrogen fixation. While NifL-NifA regulation is well understood, these conformationally flexible proteins have eluded previous attempts at structure determination. In work described here, we advance a structural model of the NifL dimer supported by a combination of scattering techniques and mass spectrometry (MS)-coupled structural analyses that report on the average structure in solution. Using a combination of small angle X-ray scattering-derived electron density maps and MS-coupled surface labeling, we investigate the conformational dynamics responsible for NifL oxygen and energy responses. Our results reveal conformational differences in the structure of NifL under reduced and oxidized conditions that provide the basis for a model for modulating NifLA complex formation in the regulation of nitrogen fixation in response to oxygen in the model diazotroph, Azotobacter vinelandii.

Recycling of bacterial RNA polymerase by the Swi2/Snf2 ATPase RapA

Free-living bacteria have regulatory systems that can quickly reprogram gene transcription in response to changes in the cellular environment. The RapA ATPase, a prokaryotic homolog of the eukaryotic Swi2/Snf2 chromatin remodeling complex, may facilitate such reprogramming, but the mechanisms by which it does so are unclear. We used multiwavelength single-molecule fluorescence microscopy in vitro to examine RapA function in the Escherichia coli transcription cycle. In our experiments, RapA at <5 nM concentration did not appear to alter transcription initiation, elongation, or intrinsic termination. Instead, we directly observed a single RapA molecule bind specifically to the kinetically stable post termination complex (PTC)-consisting of core RNA polymerase (RNAP)-bound sequence nonspecifically to double-stranded DNA-and efficiently remove RNAP from DNA within seconds in an ATP-hydrolysis-dependent reaction. Kinetic analysis elucidates the process through which RapA locates the PTC and the key mechanistic intermediates that bind and hydrolyze ATP. This study defines how RapA participates in the transcription cycle between termination and initiation and suggests that RapA helps set the balance between global RNAP recycling and local transcription reinitiation in proteobacterial genomes.

Ovarian Gene Transcriptional Responses To Antidepressant Drugs (Imipramine And Fluoxetine) In Female Wistar Rats

This study was designed to investigate ovarian gene transcriptional responses to selected antidepressant drugs (imipramine and fluoxetine) in female rats. Fifteen female rats (120 – 140 g) were used for this study. Imipramine (0.71 mg/kg) and fluoxetine (0.57 mg/kg) were given orally for 50 days. The method of RT-PCR was employed to investigate the expressions of FSH-R, p53 and Bcl-2 genes. Graphics were generated as mean +/- SEM using GraphPad Prism version 8.0. Results of the study revealed that the FSH-R, p53 and Bcl-2 expressions were significantly (p&lt;0.05) up-regulated in the imipramine-treated rats relative to their controls. Conclusively, it can be suggested that imipramine induced follicular growth and apoptosis in female Wistar rats.

A protonated cytidine stabilizes the ligand-binding pocket in the preQ1 riboswitch in thermophilic bacteria.

Riboswitches are bacterial mRNA structure elements regulating either transcription or translation of downstream genes in response to high-affinity binding of a low molecular weight ligand. Among this diverse group of RNA structures, the class-I preQ1sensing riboswitches (QSW) stand out since they are the smallest known natural riboswitches. QSW combine ligand sensing and functional control within a single structural domain that adopts a pseudoknot conformation encapsulating both the cognate ligand and the ribosome binding site. QSW also occur in thermophilic bacteria. In these cases, their tertiary structures have to be stable even at temperatures above 60 °C to be functional at the organism's optimal growth temperatures. Despite the available high-resolution structures of these riboswitches, it is not yet understood which tertiary interactions are primarily responsible for their exceptional temperature stability. Here, we show that an intricate three-dimensional network of non-canonical interactions involving various non-neighboring nucleobases is the origin of the riboswitch's thermostability. An essential part of this network is a so far undetected stably protonated cytidine. It is characterized by an exceptional high pKA value of >9.7 and could be unambiguously identified through the application of modern heteronuclear detected NMR experiments.

Transcriptional and Post-Translational Regulation of Plant bHLH Transcription Factors during the Response to Environmental Stresses.

Over the past decades, extensive research has been conducted to identify and characterize various plant transcription factors involved in abiotic stress responses. Therefore, numerous efforts have been made to improve plant stress tolerance by engineering these transcription factor genes. The plant basic Helix-Loop-Helix (bHLH) transcription factor family represents one of the most prominent gene families and contains a bHLH motif that is highly conserved in eukaryotic organisms. By binding to specific positions in promoters, they activate or repress the transcription of specific response genes and thus affect multiple variables in plant physiology such as the response to abiotic stresses, which include drought, climatic variations, mineral deficiencies, excessive salinity, and water stress. The regulation of bHLH transcription factors is crucial to better control their activity. On the one hand, they are regulated at the transcriptional level by other upstream components; on the other hand, they undergo various modifications such as ubiquitination, phosphorylation, and glycosylation at the post-translational level. Modified bHLH transcription factors can form a complex regulatory network to regulate the expression of stress response genes and thus determine the activation of physiological and metabolic reactions. This review article focuses on the structural characteristics, classification, function, and regulatory mechanism of bHLH transcription factor expression at the transcriptional and post-translational levels during their responses to various abiotic stress conditions.

JAK/STAT Signaling and Cervical Cancer: From the Cell Surface to the Nucleus.

The Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathway constitutes a rapid signaling module from the cell surface to the nucleus, and activates different cellular responses, such as proliferation, survival, migration, invasion, and inflammation. When the JAK/STAT pathway is altered, it contributes to cancer progression and metastasis. STAT proteins play a central role in developing cervical cancer, and inhibiting the JAK/STAT signaling may be necessary to induce tumor cell death. Several cancers show continuous activation of different STATs, including cervical cancer. The constitutive activation of STAT proteins is associated with a poor prognosis and overall survival. The human papillomavirus (HPV) oncoproteins E6 and E7 play an essential role in cervical cancer progression, and they activate the JAK/STAT pathway and other signals that induce proliferation, survival, and migration of cancer cells. Moreover, there is a crosstalk between the JAK/STAT signaling cascade with other signaling pathways, where a plethora of different proteins activate to induce gene transcription and cell responses that contribute to tumor growth. Therefore, inhibition of the JAK/STAT pathway shows promise as a new target in cancer treatment. In this review, we discuss the role of the JAK/STAT pathway components and the role of the HPV oncoproteins associated with cellular malignancy through the JAK/STAT proteins and other signaling pathways to induce tumor growth.

Beyond the reference: gene expression variation and transcriptional response to RNA interference in Caenorhabditis elegans.

Though natural systems harbor genetic and phenotypic variation, research in model organisms is often restricted to a reference strain. Focusing on a reference strain yields a great depth of knowledge but potentially at the cost of breadth of understanding. Furthermore, tools developed in the reference context may introduce bias when applied to other strains, posing challenges to defining the scope of variation within model systems. Here, we evaluate how genetic differences among 5 wild Caenorhabditis elegans strains affect gene expression and its quantification, in general and after induction of the RNA interference (RNAi) response. Across strains, 34% of genes were differentially expressed in the control condition, including 411 genes that were not expressed at all in at least 1 strain; 49 of these were unexpressed in reference strain N2. Reference genome mapping bias caused limited concern: despite hyperdiverse hotspots throughout the genome, 92% of variably expressed genes were robust to mapping issues. The transcriptional response to RNAi was highly strain- and target-gene-specific and did not correlate with RNAi efficiency, as the 2 RNAi-insensitive strains showed more differentially expressed genes following RNAi treatment than the RNAi-sensitive reference strain. We conclude that gene expression, generally and in response to RNAi, differs across C. elegans strains such that the choice of strain may meaningfully influence scientific inferences. Finally, we introduce a resource for querying gene expression variation in this dataset at https://wildworm.biosci.gatech.edu/rnai/.

104 Exposure to Environmental Pollutant GenX Chemical Modulates Innate and Adaptive Immunity Genes in Cow Neutrophils

Abstract GenX is an environmental contaminant with wide industrial use and found in drinking water. These chemicals have high bioaccumulation and cause adverse health effects in animals and humans. Previous study has shown that pre GenX perfluoroalkyl/polyfluoroalkyl substances (PFAS) and GenX affect immune cells but there is limited study on their impact on innate immune cells (neutrophils) in livestock, such as cows. This study evaluated the effect of GenX exposure on innate and adaptive immune response gene transcription in bovine neutrophils ex vivo. Whole blood was collected using Acid citrate dextrose as a coagulant from cows (n = 5). Neutrophils were isolated using differential centrifugation and hypotonic lysis of red cells. Isolated neutrophils were treated with GenX (100 ng), or untreated (control group) for hour at 37oC, 5%CO2 and 85% relative humidity. After treatment, total RNA was extracted using Trizol reagent, reverse transcribed to cDNA, and quantitative PCR was performed using the innate and adaptive immunity RT2 profiler array (Qiagen) with 84 genes. The qPCR data were analyzed using Livak’s method to calculate fold change (FC) in gene expression between GenX-treated and control neutrophils, and FC &amp;gt;2, (p &amp;lt; 0.05) was considered significant. Normalization of data was performed with GAPDH and Beta Actin as an internal control. Out of the 84 genes tested, 78 were expressed, 25 were upregulated and4 were downregulated, in response to GenX exposure. Exposure to GenX upregulated the expression of TLR8 (FC = 24.75), NOD2 (FC = 7.65), STAT1 (FC = 49.35), HLA-A (FC = 14.07), and NKB1A (FC = 16.52). Treatment with GenX decreased the expression TICAM1 (FC = -2.30), CD86 (FC = -2.27) and RAG1 (FC = -2.50). These results indicate that GenX exposure can activate and modulate the expression of innate and adaptive immune response genes in cow neutrophils. STAT1 is involved in transcriptional regulation and activation of TLR7/8 shifts neutrophil function from phagocytosis to NETosis. Thus, the mechanism of action of GenX on identified gene targets and their function and possible animal health consequences warrants further study.

Effects of ifosfamide and cisplatin exposure combined with a climate change scenario on the transcriptome responses of the mussel Mytilus galloprovincialis

Coastal ecosystems are currently exposed to pollutants and climate change. Namely, the increasing consumption of antineoplastic drugs and their potential release to aquatic ecosystems are raising concerns. Nevertheless, information regarding the toxicity of these drugs towards non-target species is scarce, especially considering climate change scenarios. Ifosfamide (IF) and cisplatin (CDDP) are among the antineoplastics already detected in aquatic compartments and due to their mode of action (MoA) can negatively affect aquatic organisms. This study evaluates the transcription of 17 selected target genes related to the MoA of IF and CDDP in Mytilus galloprovincialis gills exposed to environmentally relevant and toxicological meaningful concentrations (IF – 10, 100, 500 ng/L; CDDP – 10, 100, 1000 ng/L), under an actual (17 °C) and predicted warming scenario (21 °C). Results showed an upregulation of the cyp4y1 gene when exposed to the highest concentrations of IF, regardless of the temperature. Both drugs upregulated genes related to DNA damage and apoptosis (p53, caspase 8 and gadd45), especially under warmer conditions. Increased temperature also downregulated genes related to stress and immune responses (krs and mydd88). Therefore, the present results showed a gene transcriptional response of mussels to increasing concentrations of antineoplastics and that warmer temperatures modulated those effects.