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Biochemistry and Biophysics Reports Mar 2020This study examined the effects of microtubule-targeting anticancer drugs (paclitaxel, cabazitaxel, and eribulin) on the expression of drug efflux transporter...
This study examined the effects of microtubule-targeting anticancer drugs (paclitaxel, cabazitaxel, and eribulin) on the expression of drug efflux transporter P-glycoprotein, which is encoded by . Paclitaxel and eribulin induced promoter activity in a concentration-dependent manner, while cabazitaxel had little effect in human intestinal epithelial LS174T cells. Overexpression of the nuclear receptor pregnane X receptor (PXR) gene () enhanced paclitaxel- and eribulin-induced activation, but expression of the nuclear receptor co-repressor silencing mediator for retinoid and thyroid receptors (SMRT) gene () repressed activation. Eribulin increased the mRNA and protein expression of P-glycoprotein in LS174T cells. Cellular uptake of rhodamine 123 and calcein-acetoxymethyl ester (calcein-AM), P-glycoprotein substrates, decreased in paclitaxel- or eribulin-treated LS174T cells. Eribulin also increased promoter activity in human breast cancer MCF7 cells. The results suggest that the microtubule-targeting anticancer drug eribulin can induce the drug efflux transporter P-glycoprotein via PXR in human intestinal and breast cancer cells and thus influence the efficacy of anticancer drugs.
PubMed: 31993509
DOI: 10.1016/j.bbrep.2020.100727 -
Scientific Reports Jan 2022Individual cell types of human tissues have their own CpG site methylation profiles, which might be utilized for the development of methylation markers to denote...
Individual cell types of human tissues have their own CpG site methylation profiles, which might be utilized for the development of methylation markers to denote tumor-infiltrating lymphocytes (TILs). We aimed to develop DNA methylation markers that recapitulate the densities of TILs in gastric carcinoma (GC). Through genome-wide methylation profiling, NCOR2, PARK2, and ZSCAN12 were found to be highly methylated in CD3-positive and CD8-positive cells and rarely methylated in tumor cells. Scores of the three methylation markers were analyzed for their relationship with the overall survival and recurrence-free survival of patients with advanced GC (n = 471). The scores of three methylation markers were closely associated with densities of CD3-positive or CD8-positive cells at the tumor center or invasive front of GCs and found to be a significant prognostic factor in univariate analysis of overall survival and recurrence-free survival. In multivariate analysis, the highest score showed hazard ratios of 0.513 (CI 0.306-0.857) and 0.434 (CI 0.261-0.720) for overall survival and recurrence-free survival, respectively. The findings suggest that methylation markers signifying TILs might be utilized for the recapitulation of TIL density in GCs and serve as biomarkers for predicting prognosis in patients with GC.
Topics: Biomarkers; CD8-Positive T-Lymphocytes; Carcinoma; DNA Methylation; Female; Forecasting; Humans; Kruppel-Like Transcription Factors; Lymphocytes, Tumor-Infiltrating; Male; Middle Aged; Nuclear Receptor Co-Repressor 2; Prognosis; Stomach Neoplasms; Survival Rate; Tumor Microenvironment; Ubiquitin-Protein Ligases
PubMed: 35039565
DOI: 10.1038/s41598-022-04797-9 -
Biochimica Et Biophysica Acta Sep 2016Post-translational modification (PTM) of nuclear receptor superfamily members regulates various aspects of their biology to include sub-cellular localization, the...
Post-translational modification (PTM) of nuclear receptor superfamily members regulates various aspects of their biology to include sub-cellular localization, the repertoire of protein-binding partners, as well as their stability and mode of degradation. The nuclear receptor pregnane X receptor (PXR, NR1I2) is a master-regulator of the drug-inducible gene expression in liver and intestine. The PXR-mediated gene activation program is primarily recognized to increase drug metabolism, drug transport, and drug efflux pathways in these tissues. The activation of PXR also has important implications in significant human diseases including inflammatory bowel disease and cancer. Our recent investigations reveal that PXR is modified by multiple PTMs to include phosphorylation, SUMOylation, and ubiquitination. Using both primary cultures of hepatocytes and cell-based assays, we show here that PXR is modified through acetylation on lysine residues. Further, we show that increased acetylation of PXR stimulates its increased SUMO-modification to support active transcriptional suppression. Pharmacologic inhibition of lysine de-acetylation using trichostatin A (TSA) alters the sub-cellular localization of PXR in cultured hepatocytes, and also has a profound impact upon PXR transactivation capacity. Both the acetylation and SUMOylation status of the PXR protein is affected by its ability to associate with the lysine de-acetylating enzyme histone de-acetylase (HDAC)3 in a complex with silencing mediator of retinoic acid and thyroid hormone receptor (SMRT). Taken together, our data support a model in which a SUMO-acetyl 'switch' occurs such that acetylation of PXR likely stimulates SUMO-modification of PXR to promote the active repression of PXR-target gene expression. This article is part of a Special Issue entitled: Xenobiotic nuclear receptors: New Tricks for An Old Dog, edited by Dr. Wen Xie.
Topics: Acetylation; Amino Acid Sequence; Animals; Cell Line; Genes, Reporter; Hepatocytes; Histone Deacetylases; Hydroxamic Acids; Luciferases; Lysine; Male; Mice; Mice, Inbred C57BL; Nuclear Receptor Co-Repressor 2; Pregnane X Receptor; Primary Cell Culture; Protein Processing, Post-Translational; Receptors, Steroid; Sumoylation; Transcriptional Activation; Ubiquitination
PubMed: 26883953
DOI: 10.1016/j.bbagrm.2016.02.008 -
BMC Plant Biology Dec 2019Low temperature is one of the main environmental factors that limits crop growth, development, and production. Medicago falcata is an important leguminous herb that is...
BACKGROUND
Low temperature is one of the main environmental factors that limits crop growth, development, and production. Medicago falcata is an important leguminous herb that is widely distributed worldwide. M. falcata is related to alfalfa but is more tolerant to low temperature than alfalfa. Understanding the low temperature tolerance mechanism of M. falcata is important for the genetic improvement of alfalfa.
RESULTS
In this study, we explored the transcriptomic changes in the roots of low-temperature-treated M. falcata plants by combining SMRT sequencing and NGS technologies. A total of 115,153 nonredundant sequences were obtained, and 8849 AS events, 73,149 SSRs, and 4189 lncRNAs were predicted. A total of 111,587 genes from SMRT sequencing were annotated, and 11,369 DEGs involved in plant hormone signal transduction, protein processing in endoplasmic reticulum, carbon metabolism, glycolysis/gluconeogenesis, starch and sucrose metabolism, and endocytosis pathways were identified. We characterized 1538 TF genes into 45 TF gene families, and the most abundant TF family was the WRKY family, followed by the ERF, MYB, bHLH and NAC families. A total of 134 genes, including 101 whose expression was upregulated and 33 whose expression was downregulated, were differentially coexpressed at all five temperature points. PB40804, PB75011, PB110405 and PB108808 were found to play crucial roles in the tolerance of M. falcata to low temperature. WGCNA revealed that the MEbrown module was significantly correlated with low-temperature stress in M. falcata. Electrolyte leakage was correlated with most genetic modules and verified that electrolyte leakage can be used as a direct stress marker in physiological assays to indicate cell membrane damage from low-temperature stress. The consistency between the qRT-PCR results and RNA-seq analyses confirmed the validity of the RNA-seq data and the analysis of the regulatory mechanism of low-temperature stress on the basis of the transcriptome.
CONCLUSIONS
The full-length transcripts generated in this study provide a full characterization of the transcriptome of M. falcata and may be useful for mining new low-temperature stress-related genes specific to M. falcata. These new findings could facilitate the understanding of the low-temperature-tolerance mechanism of M. falcata.
Topics: Acclimatization; Cold Temperature; Gene Expression Profiling; Medicago; Plant Roots; Transcriptome
PubMed: 31864302
DOI: 10.1186/s12870-019-2192-1 -
Nucleic Acids Research Oct 2019In the absence of ligands, the nuclear receptor PPARβ/δ recruits the NCOR and SMRT corepressors, which form complexes with HDAC3, to canonical target genes. Agonistic...
In the absence of ligands, the nuclear receptor PPARβ/δ recruits the NCOR and SMRT corepressors, which form complexes with HDAC3, to canonical target genes. Agonistic ligands cause dissociation of corepressors and enable enhanced transcription. Vice versa, synthetic inverse agonists augment corepressor recruitment and repression. Both basal repression of the target gene ANGPTL4 and reinforced repression elicited by inverse agonists are partially insensitive to HDAC inhibition. This raises the question how PPARβ/δ represses transcription mechanistically. We show that the PPARβ/δ inverse agonist PT-S264 impairs transcription initiation by decreasing recruitment of activating Mediator subunits, RNA polymerase II, and TFIIB, but not of TFIIA, to the ANGPTL4 promoter. Mass spectrometry identifies NCOR as the main PT-S264-dependent interactor of PPARβ/δ. Reconstitution of knockout cells with PPARβ/δ mutants deficient in basal repression results in diminished recruitment of NCOR, SMRT, and HDAC3 to PPAR target genes, while occupancy by RNA polymerase II is increased. PT-S264 restores binding of NCOR, SMRT, and HDAC3 to the mutants, resulting in reduced polymerase II occupancy. Our findings corroborate deacetylase-dependent and -independent repressive functions of HDAC3-containing complexes, which act in parallel to downregulate transcription.
Topics: Angiopoietin-Like Protein 4; Cell Line; Histone Deacetylases; Humans; Ligands; Mass Spectrometry; Multiprotein Complexes; Nuclear Receptor Co-Repressor 1; Nuclear Receptor Co-Repressor 2; PPAR-beta; Promoter Regions, Genetic; RNA Polymerase II; Transcription Factor TFIIB; Transcription Factors; Transcription, Genetic
PubMed: 31428774
DOI: 10.1093/nar/gkz685 -
Scientific Reports Sep 2022Ecologically, Halophila beccarii Asch. is considered as a colonizing or a pioneer seagrass species and a "tiny but mighty" seagrass species, since it may recover quickly...
Ecologically, Halophila beccarii Asch. is considered as a colonizing or a pioneer seagrass species and a "tiny but mighty" seagrass species, since it may recover quickly from disturbance generally. The use of transcriptome technology can provide a better understanding of the physiological processes of seagrasses. To date, little is known about the genome and transcriptome information of H. beccarii. In this study, we used single molecule real-time (SMRT) sequencing to obtain full-length transcriptome data and characterize the transcriptome structure. A total of 11,773 of the 15,348 transcripts were successfully annotated in seven databases. In addition, 1573 long non-coding RNAs, 8402 simple sequence repeats and 2567 transcription factors were predicted in all the transcripts. A GO analysis showed that 5843 transcripts were divided into three categories, including biological process (BP), cellular component (CC) and molecular function (MF). In these three categories, metabolic process (1603 transcripts), protein-containing complex (515 transcripts) and binding (3233 transcripts) were the primary terms in BP, CC, and MF, respectively. The major types of transcription factors were involved in MYB-related and NF-YB families. To the best of our knowledge, this is the first report of the transcriptome of H. beccarii using SMRT sequencing technology.
Topics: Gene Expression Profiling; High-Throughput Nucleotide Sequencing; Humans; Hydrocharitaceae; Microsatellite Repeats; Molecular Sequence Annotation; Transcription Factors; Transcriptome
PubMed: 36180578
DOI: 10.1038/s41598-022-20988-w -
Cells Mar 2019Chicken ovalbumin upstream promoter-transcription factor I (COUP-TFI) is an orphan receptor and member of the nuclear receptor superfamily. Among a series of methylene...
Chicken ovalbumin upstream promoter-transcription factor I (COUP-TFI) is an orphan receptor and member of the nuclear receptor superfamily. Among a series of methylene substituted diindolylmethanes (C-DIMs) containing substituted phenyl and heteroaromatic groups, we identified 1,1-bis(3'-indolyl)-1-(4-pyridyl)-methane (DIM-C-Pyr-4) as an activator of COUP-TFI. Structure activity studies with structurally diverse heteroaromatic C-DIMs showed that the pyridyl substituted compound was active and the 4-pyridyl substituent was more potent than the 2- or 3-pyridyl analogs in transactivation assays in breast cancer cells. The DIM-C-Pyr-4 activated chimeric GAL4-COUP-TFI constructs containing full length, C- or N-terminal deletions, and transactivation was inhibited by phosphatidylinositol-3-kinase and protein kinase A inhibitors. However, DIM-C-Pyr-4 also induced transactivation and interactions of COUP-TFI and steroid receptor coactivators-1 and -2 in mammalian two-hybrid assays, and ligand-induced interactions of the C-terminal region of COUP-TFI were not affected by kinase inhibitors. We also showed that DIM-C-Pyr-4 activated COUP-TFI-dependent early growth response 1 (Egr-1) expression and this response primarily involved COUP-TFI interactions with Sp3 and to a lesser extent Sp1 bound to the proximal region of the Egr-1 promoter. Modeling studies showed interactions of DIM-C-Pyr-4 within the ligand binding domain of COUP-TFI. This report is the first to identify a COUP-TFI agonist and demonstrate activation of COUP-TFI-dependent Egr-1 expression.
Topics: Animals; COUP Transcription Factor I; Cell Line, Tumor; Early Growth Response Protein 1; Humans; Indoles; Ligands; Mice; Models, Molecular; Nuclear Receptor Co-Repressor 2; Sp Transcription Factors
PubMed: 30866413
DOI: 10.3390/cells8030220 -
Heliyon Feb 2023Common vetch is an important leguminous forage for both livestock fodder and green manure and has a tremendous latent capacity in a sustainable agroecosystem. In the...
Common vetch is an important leguminous forage for both livestock fodder and green manure and has a tremendous latent capacity in a sustainable agroecosystem. In the present study, a comprehensive transcriptome analysis of the aboveground leaves and underground roots of common vetch under multiple abiotic stress treatments, including NaCl, drought, cold, and cold drought, was performed using hybrid-sequencing technology, i. e. single-molecule real-time sequencing technology (SMRT) and supplemented by next-generation sequencing (NGS) technology. A total of 485,038 reads of insert (ROIs) with a mean length of 2606 bp and 228,261 full-length nonchimeric (FLNC) reads were generated. After deduplication, 39,709 transcripts were generated. Of these transcripts, we identified 1059 alternative splicing (AS) events, 17,227 simple sequence repeats (SSRs), and 1647 putative transcription factors (TFs). Furthermore, 640 candidates long noncoding RNAs (lncRNAs) and 28,256 complete coding sequences (CDSs) were identified. In gene annotation analyses, a total of 38,826 transcripts (97.78%) were annotated in eight public databases. Finally, seven multiple abiotic stress-responsive candidate genes were obtained through gene expression, annotation information, and protein-protein interaction (PPI) networks. Our research not only enriched the structural information of FL transcripts in common vetch, but also provided useful information for exploring the molecular mechanism of multiple abiotic stress tolerance between aboveground and underground tissues in common vetch and related legumes.
PubMed: 36816321
DOI: 10.1016/j.heliyon.2023.e13536 -
PloS One 2012The signaling pathways associated with the Toll-like receptors (TLRs) and nuclear factor-kappaB (NF-κB) are essential to pro-inflammatory cytokine and chemokine...
The signaling pathways associated with the Toll-like receptors (TLRs) and nuclear factor-kappaB (NF-κB) are essential to pro-inflammatory cytokine and chemokine expression, as well as initiating innate epithelial immune responses. The TLR/NF-κB signaling pathways must be stringently controlled through an intricate network of positive and negative regulatory elements. MicroRNAs (miRNAs) are non-coding small RNAs that regulate the stability and/or translation of protein-coding mRNAs. Herein we report that miR-16 promotes NF-κB-regulated transactivation of the IL-8 gene by suppression of the silencing mediator for retinoid and thyroid hormone receptor (SMRT). LPS stimulation activated miR-16 gene transcription in human monocytes (U937) and biliary epithelial cells (H69) through MAPK-dependent mechanisms. Transfection of cells with the miR-16 precursor promoted LPS-induced production of IL-8, IL-6, and IL-1α, without a significant effect on their RNA stability. Instead, an increase in NF-κB-regulated transactivation of the IL-8 gene was confirmed in cells following transfection of miR-16 precursor. Importantly, miR-16 targeted the 3'-untranslated region of SMRT and caused translational suppression of SMRT. LPS decreased SMRT expression via upregulation of miR-16. Moreover, functional manipulation of SMRT altered NF-κB-regulated transactivation of LPS-induced IL-8 expression. These data suggest that miR-16 targets SMRT and modulates NF-κB-regulated transactivation of the IL-8 gene.
Topics: Anthracenes; Cells, Cultured; Enzyme Inhibitors; Extracellular Signal-Regulated MAP Kinases; Flavonoids; Gene Expression Regulation; Humans; Imidazoles; Interleukin-8; Lipopolysaccharides; MAP Kinase Signaling System; MicroRNAs; NF-kappa B; Nuclear Receptor Co-Repressor 2; Pyridines; Transcription, Genetic; Transcriptional Activation; U937 Cells
PubMed: 22292036
DOI: 10.1371/journal.pone.0030772 -
Frontiers in Bioscience (Landmark... Nov 2021: Tadpole tail develops from the tailbud, an apparently homogenous mass of cells at the posterior of the embryo. While much progress has been made in understanding the...
: Tadpole tail develops from the tailbud, an apparently homogenous mass of cells at the posterior of the embryo. While much progress has been made in understanding the origin and the induction of the tailbud, the subsequent outgrowth and differentiation have received much less attention, particularly with regard to global gene expression changes. : By using RNA-seq with SMRT and further analyses, we report the transcriptome profiles at four key stages of tail development, from a small tailbud to the onset of feeding (S18, S19, S21 and S28) in , an anuran with a number of advantages for developmental and genetic studies. : We obtained 48,826 transcripts and discovered 8807 differentially expressed transcripts (DETs, q < 0.05) among these four developmental stages. We functionally classified these DETs by using GO and KEGG analyses and revealed 110 significantly enriched GO categories and 6 highly enriched KEGG pathways (Protein digestion and absorption; ECM-receptor interaction; Pyruvate metabolism; Fatty acid degradation; Valine, leucine and isoleucine degradation; and Glyoxylate and dicarboxylate metabolism) that are likely critically involved in developmental changes in the tail. In addition, analyses of DETs between any two individual stages demonstrated the involvement of distinct biological pathways/GO terms at different stages of tail development. Furthermore, the most dramatic changes in gene expression profile are those between S28 and any of the other three stages. The upregulated DETs at S28 are highly enriched in "myosin complex" and "potassium channel activity", which are important for muscle contraction, a critical function of the tail that the animal needs by the end of embryogenesis. Additionally, many DETs and enriched pathways discovered here during tail development, such as HDAC1, Hes1 and Hippo signaling pathway, have also been reported to be vital for the tissue/organ regeneration, suggesting conserved functions between development and regeneration. : The present staudy provides a golbal overview of gene expression patterns and new insights into the mechanism involved in anuran tail development and regeneration.
Topics: Animals; Anura; Gene Expression Profiling; Gene Expression Regulation; Hippo Signaling Pathway; Transcriptome
PubMed: 34856748
DOI: 10.52586/5004