Juvenile hormone (JH) signaling is realized at the gene regulatory level by receptors of the bHLH-PAS transcription factor family. The sesquiterpenoid hormones and their synthetic mimics are agonist ligands of a unique JH receptor (JHR) protein, methoprene-tolerant (MET). Upon binding an agonist to its PAS-B cavity, MET dissociates from a cytoplasmic chaperone complex including HSP83 and concomitantly switches to a bHLH-PAS partner taiman, forming a nuclear, transcriptionally active JHR heterodimer. This course of events resembles the vertebrate aryl hydrocarbon receptor (AHR), activated by a plethora of endogenous and synthetic compounds. Like in AHR, the pliable PAS-B cavity of MET adjusts to diverse ligands and binds them through similar mechanisms. Despite recent progress, we only begin to discern agonist-induced conformational shifts within the PAS-B domain, with the ultimate goal of understanding how these localized changes stimulate the assembly of the active JHR complex and, thus, fully grasp the mechanism of JHR signaling.

• MeSH
• juvenilní hormony * metabolismus   MeSH
• signální transdukce MeSH
• transkripční faktory bHLH metabolismus   genetika   chemie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

The presence of key hypoxia regulators, namely, hypoxia-inducible factor (HIF)-1α or HIF-2α, in tumors is associated with poor patient prognosis. Hypoxia massively activates several genes, including the one encoding the BCRP transporter that proffers multidrug resistance to cancer cells through the xenobiotic efflux and is a determinant of the side population (SP) associated with cancer stem-like phenotypes. As natural medicine comes to the fore, it is instinctive to look for natural agents possessing powerful features against cancer resistance. Hypericin, a pleiotropic agent found in Hypericum plants, is a good example as it is a BCRP substrate and potential inhibitor, and an SP and HIF modulator. Here, we showed that hypericin efficiently accumulated in hypoxic cancer cells, degraded HIF-1/2α, and decreased BCRP efflux together with hypoxia, thus diminishing the SP population. On the contrary, this seemingly favorable result was accompanied by the stimulated migration of this minor population that preserved the SP phenotype. Because hypoxia unexpectedly decreased the BCRP level and SP fraction, we compared the SP and non-SP proteomes and their changes under hypoxia in the A549 cell line. We identified differences among protein groups connected to the epithelial-mesenchymal transition, although major changes were related to hypoxia, as the upregulation of many proteins, including serpin E1, PLOD2 and LOXL2, that ultimately contribute to the initiation of the metastatic cascade was detected. Altogether, this study helps in clarifying the innate and hypoxia-triggered resistance of cancer cells and highlights the ambivalent role of natural agents in the biology of these cells.

• MeSH
• ABC transportér z rodiny G, člen 2 genetika   metabolismus   MeSH
• faktor 1 indukovatelný hypoxií - podjednotka alfa metabolismus   MeSH
• hypoxie buňky MeSH
• hypoxie MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• nádorové proteiny genetika   metabolismus   MeSH
• nádory * metabolismus   MeSH
• regulace genové exprese u nádorů MeSH
• transkripční faktory bHLH genetika   metabolismus   MeSH
• vedlejší populace buněk * patologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

The tissue distribution and prognostic relevance of subtype-specific proteins (ASCL1, NEUROD1, POU2F3, YAP1) present an evolving area of research in small-cell lung cancer (SCLC). The expression of subtype-specific transcription factors and P53 and RB1 proteins were measured by immunohistochemistry (IHC) in 386 surgically resected SCLC samples. Correlations between subtype-specific proteins and in vitro efficacy of various therapeutic agents were investigated by proteomics and cell viability assays in 26 human SCLC cell lines. Besides SCLC-A (ASCL1-dominant), SCLC-AN (combined ASCL1/NEUROD1), SCLC-N (NEUROD1-dominant), and SCLC-P (POU2F3-dominant), IHC and cluster analyses identified a quadruple-negative SCLC subtype (SCLC-QN). No unique YAP1-subtype was found. The highest overall survival rates were associated with non-neuroendocrine subtypes (SCLC-P and SCLC-QN) and the lowest with neuroendocrine subtypes (SCLC-A, SCLC-N, SCLC-AN). In univariate analyses, high ASCL1 expression was associated with poor prognosis and high POU2F3 expression with good prognosis. Notably, high ASCL1 expression influenced survival outcomes independently of other variables in a multivariate model. High POU2F3 and YAP1 protein abundances correlated with sensitivity and resistance to standard-of-care chemotherapeutics, respectively. Specific correlation patterns were also found between the efficacy of targeted agents and subtype-specific protein abundances. In conclusion, we investigated the clinicopathological relevance of SCLC molecular subtypes in a large cohort of surgically resected specimens. Differential IHC expression of ASCL1, NEUROD1, and POU2F3 defines SCLC subtypes. No YAP1-subtype can be distinguished by IHC. High POU2F3 expression is associated with improved survival in a univariate analysis, whereas elevated ASCL1 expression is an independent negative prognosticator. Proteomic and cell viability assays of human SCLC cell lines revealed distinct vulnerability profiles defined by transcription regulators. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

• MeSH
• lidé MeSH
• malobuněčný karcinom plic * genetika   metabolismus   chirurgie   MeSH
• nádorové buněčné linie MeSH
• nádory plic * genetika   metabolismus   chirurgie   MeSH
• prognóza MeSH
• proteomika MeSH
• regulace genové exprese u nádorů MeSH
• transkripční faktory bHLH genetika   metabolismus   MeSH
• transkripční faktory genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• multicentrická studie MeSH
• práce podpořená grantem MeSH

The nine-amino-acid activation domain (9aaTAD) is defined by a short amino acid pattern including two hydrophobic regions (positions p3-4 and p6-7). The KIX domain of mediator transcription CBP interacts with the 9aaTAD domains of transcription factors MLL, E2A, NF-kB, and p53. In this study, we analyzed the 9aaTADs-KIX interactions by nuclear magnetic resonance. The positions of three KIX helixes α1-α2-α3 are influenced by sterically-associated hydrophobic I611, L628, and I660 residues that are exposed to solvent. The positions of two rigid KIX helixes α1 and α2 generate conditions for structural folding in the flexible KIX-L12-G2 regions localized between them. The three KIX I611, L628, and I660 residues interact with two 9aaTAD hydrophobic residues in positions p3 and p4 and together build a hydrophobic core of five residues (5R). Numerous residues in 9aaTAD position p3 and p4 could provide this interaction. Following binding of the 9aaTAD to KIX, the hydrophobic I611, L628, and I660 residues are no longer exposed to solvent and their position changes inside the hydrophobic core together with position of KIX α1-α2-α3 helixes. The new positions of the KIX helixes α1 and α2 allow the KIX-L12-G2 enhanced formation. The second hydrophobic region of the 9aaTAD (positions p6 and p7) provides strong binding with the KIX-L12-G2 region. Similarly, multiple residues in 9aaTAD position p6 and p7 could provide this interaction. In conclusion, both 9aaTAD regions p3, p4 and p6, p7 provide co-operative and highly universal binding to mediator KIX. The hydrophobic core 5R formation allows new positions of the rigid KIX α-helixes and enables the enhanced formation of the KIX-L12-G2 region. This contributes to free energy and is the key for the KIX-9aaTAD binding. Therefore, the 9aaTAD-KIX interactions do not operate under the rigid key-and-lock mechanism what explains the 9aaTAD natural variability.

• MeSH
• aminokyselinové motivy MeSH
• histonlysin-N-methyltransferasa chemie   metabolismus   MeSH
• interakční proteinové domény a motivy MeSH
• lidé MeSH
• nádorový supresorový protein p53 chemie   metabolismus   MeSH
• NF-kappa B chemie   metabolismus   MeSH
• protein vázající CREB chemie   metabolismus   MeSH
• protoonkogenní protein MLL chemie   metabolismus   MeSH
• transkripční faktory bHLH chemie   metabolismus   MeSH
• transkripční faktory chemie   metabolismus   MeSH
• vazba proteinů MeSH
• vazebná místa MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Diabetes is a metabolic disease that involves the death or dysfunction of the insulin-secreting β cells in the pancreas. Consequently, most diabetes research is aimed at understanding the molecular and cellular bases of pancreatic development, islet formation, β-cell survival, and insulin secretion. Complex interactions of signaling pathways and transcription factor networks regulate the specification, growth, and differentiation of cell types in the developing pancreas. Many of the same regulators continue to modulate gene expression and cell fate of the adult pancreas. The transcription factor NEUROD1 is essential for the maturation of β cells and the expansion of the pancreatic islet cell mass. Mutations of the Neurod1 gene cause diabetes in humans and mice. However, the different aspects of the requirement of NEUROD1 for pancreas development are not fully understood. In this study, we investigated the role of NEUROD1 during the primary and secondary transitions of mouse pancreas development. We determined that the elimination of Neurod1 impairs the expression of key transcription factors for α- and β-cell differentiation, β-cell proliferation, insulin production, and islets of Langerhans formation. These findings demonstrate that the Neurod1 deletion altered the properties of α and β endocrine cells, resulting in severe neonatal diabetes, and thus, NEUROD1 is required for proper activation of the transcriptional network and differentiation of functional α and β cells.

• MeSH
• beta-buňky cytologie   metabolismus   MeSH
• buněčná diferenciace MeSH
• buněčný rodokmen MeSH
• diabetes mellitus genetika   MeSH
• inzulin metabolismus   MeSH
• Langerhansovy ostrůvky cytologie   metabolismus   ultrastruktura   MeSH
• myši inbrední C57BL MeSH
• myši transgenní MeSH
• novorozená zvířata MeSH
• pankreas cytologie   embryologie   MeSH
• proliferace buněk MeSH
• transkripční faktory bHLH genetika   metabolismus   MeSH
• vývojová regulace genové exprese MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

We review the molecular basis of several transcription factors (Eya1, Sox2), including the three related genes coding basic helix-loop-helix (bHLH; see abbreviations) proteins (Neurog1, Neurod1, Atoh1) during the development of spiral ganglia, cochlear nuclei, and cochlear hair cells. Neuronal development requires Neurog1, followed by its downstream target Neurod1, to cross-regulate Atoh1 expression. In contrast, hair cells and cochlear nuclei critically depend on Atoh1 and require Neurod1 expression for interactions with Atoh1. Upregulation of Atoh1 following Neurod1 loss changes some vestibular neurons' fate into "hair cells", highlighting the significant interplay between the bHLH genes. Further work showed that replacing Atoh1 by Neurog1 rescues some hair cells from complete absence observed in Atoh1 null mutants, suggesting that bHLH genes can partially replace one another. The inhibition of Atoh1 by Neurod1 is essential for proper neuronal cell fate, and in the absence of Neurod1, Atoh1 is upregulated, resulting in the formation of "intraganglionic" HCs. Additional genes, such as Eya1/Six1, Sox2, Pax2, Gata3, Fgfr2b, Foxg1, and Lmx1a/b, play a role in the auditory system. Finally, both Lmx1a and Lmx1b genes are essential for the cochlear organ of Corti, spiral ganglion neuron, and cochlear nuclei formation. We integrate the mammalian auditory system development to provide comprehensive insights beyond the limited perception driven by singular investigations of cochlear neurons, cochlear hair cells, and cochlear nuclei. A detailed analysis of gene expression is needed to understand better how upstream regulators facilitate gene interactions and mammalian auditory system development.

• MeSH
• kochlea cytologie   metabolismus   MeSH
• lidé MeSH
• neurogeneze genetika   fyziologie   MeSH
• transkripční faktory bHLH genetika   metabolismus   MeSH
• transkripční faktory genetika   metabolismus   MeSH
• vláskové buňky metabolismus   MeSH
• vývojová regulace genové exprese MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

The plant-specific receptor-like cytoplasmic kinases (RLCKs) form a large, poorly characterized family. Members of the RLCK VI_A class of dicots have a unique characteristic: their activity is regulated by Rho-of-plants (ROP) GTPases. The biological function of one of these kinases was investigated using a T-DNA insertion mutant and RNA interference. Loss of RLCK VI_A2 function resulted in restricted cell expansion and seedling growth. Although these phenotypes could be rescued by exogenous gibberellin, the mutant did not exhibit lower levels of active gibberellins nor decreased gibberellin sensitivity. Transcriptome analysis confirmed that gibberellin is not the direct target of the kinase; its absence rather affected the metabolism and signalling of other hormones such as auxin. It is hypothesized that gibberellins and the RLCK VI_A2 kinase act in parallel to regulate cell expansion and plant growth. Gene expression studies also indicated that the kinase might have an overlapping role with the transcription factor circuit (PIF4-BZR1-ARF6) controlling skotomorphogenesis-related hypocotyl/cotyledon elongation. Furthermore, the transcriptomic changes revealed that the loss of RLCK VI_A2 function alters cellular processes that are associated with cell membranes, take place at the cell periphery or in the apoplast, and are related to cellular transport and/or cell wall reorganisation.

• MeSH
• Arabidopsis účinky léků   enzymologie   genetika   růst a vývoj   MeSH
• DNA bakterií genetika   metabolismus   MeSH
• DNA vazebné proteiny genetika   metabolismus   MeSH
• geneticky modifikované rostliny MeSH
• gibereliny metabolismus   farmakologie   MeSH
• hypokotyl účinky léků   enzymologie   genetika   růst a vývoj   MeSH
• inzerční mutageneze MeSH
• kotyledon účinky léků   enzymologie   genetika   růst a vývoj   MeSH
• kyseliny indoloctové metabolismus   farmakologie   MeSH
• protein-serin-threoninkinasy genetika   metabolismus   MeSH
• proteiny huseníčku genetika   metabolismus   MeSH
• regulace genové exprese u rostlin * MeSH
• regulátory růstu rostlin farmakologie   MeSH
• semenáček účinky léků   enzymologie   genetika   růst a vývoj   MeSH
• stanovení celkové genové exprese MeSH
• transkripční faktory bHLH genetika   metabolismus   MeSH
• transkripční faktory genetika   metabolismus   MeSH
• transkriptom MeSH
• vývojová regulace genové exprese MeSH
• Publikační typ
• časopisecké články MeSH

Ear development requires the transcription factors ATOH1 for hair cell differentiation and NEUROD1 for sensory neuron development. In addition, NEUROD1 negatively regulates Atoh1 gene expression. As we previously showed that deletion of the Neurod1 gene in the cochlea results in axon guidance defects and excessive peripheral innervation of the sensory epithelium, we hypothesized that some of the innervation defects may be a result of abnormalities in NEUROD1 and ATOH1 interactions. To characterize the interdependency of ATOH1 and NEUROD1 in inner ear development, we generated a new Atoh1/Neurod1 double null conditional deletion mutant. Through careful comparison of the effects of single Atoh1 or Neurod1 gene deletion with combined double Atoh1 and Neurod1 deletion, we demonstrate that NEUROD1-ATOH1 interactions are not important for the Neurod1 null innervation phenotype. We report that neurons lacking Neurod1 can innervate the flat epithelium without any sensory hair cells or supporting cells left after Atoh1 deletion, indicating that neurons with Neurod1 deletion do not require the presence of hair cells for axon growth. Moreover, transcriptome analysis identified genes encoding axon guidance and neurite growth molecules that are dysregulated in the Neurod1 deletion mutant. Taken together, we demonstrate that much of the projections of NEUROD1-deprived inner ear sensory neurons are regulated cell-autonomously.

• MeSH
• apoptóza genetika   MeSH
• axony metabolismus   MeSH
• biologické modely MeSH
• buněčná diferenciace genetika   MeSH
• Cortiho orgán patologie   MeSH
• delece genu MeSH
• epitel metabolismus   MeSH
• ganglion spirale metabolismus   MeSH
• mutace genetika   MeSH
• myši knockoutované MeSH
• nervová vlákna metabolismus   MeSH
• proteiny nervové tkáně genetika   metabolismus   MeSH
• regulace genové exprese MeSH
• stanovení celkové genové exprese MeSH
• transkripční faktory bHLH genetika   metabolismus   MeSH
• transkripční faktory SOXB1 metabolismus   MeSH
• vláskové buňky metabolismus   patologie   ultrastruktura   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The efforts for therapeutic targeting of the aryl hydrocarbon receptor (AhR) have emerged in recent years. We investigated the effects of available antimigraine triptan drugs, having an indole core in their structure, on AhR signaling in human hepatic and intestinal cells. Activation of AhR in reporter gene assays was observed for Avitriptan and to a lesser extent for Donitriptan, while other triptans were very weak or no activators of AhR. Using competitive binding assay and by homology docking, we identified Avitriptan as a low-affinity ligand of AhR. Avitriptan triggered nuclear translocation of AhR and increased binding of AhR in CYP1A1 promotor DNA, as revealed by immune-fluorescence microscopy and chromatin immune-precipitation assay, respectively. Strong induction of CYP1A1 mRNA was achieved by Avitriptan in wild type but not in AhR-knockout, immortalized human hepatocytes, implying that induction of CYP1A1 is AhR-dependent. Increased levels of CYP1A1 mRNA by Avitriptan were observed in human colon carcinoma cells LS180 but not in primary cultures of human hepatocytes. Collectively, we show that Avitriptan is a weak ligand and activator of human AhR, which induces the expression of CYP1A1 in a cell-type specific manner. Our data warrant the potential off-label therapeutic application of Avitriptan as an AhR-agonist drug.

• MeSH
• aktivace enzymů účinky léků   MeSH
• cytochrom P-450 CYP1A1 genetika   MeSH
• hepatocyty metabolismus   MeSH
• kultivované buňky MeSH
• lidé MeSH
• ligandy MeSH
• molekulární modely MeSH
• orgánová specificita MeSH
• přehodnocení terapeutických indikací léčivého přípravku MeSH
• promotorové oblasti (genetika) účinky léků   MeSH
• receptory aromatických uhlovodíků agonisté   chemie   metabolismus   MeSH
• simulace molekulového dockingu MeSH
• střevní sliznice metabolismus   MeSH
• sulfonamidy farmakologie   MeSH
• transkripční faktory bHLH agonisté   chemie   metabolismus   MeSH
• tryptaminy farmakologie   MeSH
• upregulace MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

We examined the effects of gut microbial catabolites of tryptophan on the aryl hydrocarbon receptor (AhR). Using a reporter gene assay, we show that all studied catabolites are low-potency agonists of human AhR. The efficacy of catabolites differed substantially, comprising agonists with no or low (i3-propionate, i3-acetate, i3-lactate, i3-aldehyde), medium (i3-ethanol, i3-acrylate, skatole, tryptamine), and high (indole, i3-acetamide, i3-pyruvate) efficacies. We displayed ligand-selective antagonist activities by i3-pyruvate, i3-aldehyde, indole, skatole, and tryptamine. Ligand binding assay identified low affinity (skatole, i3-pyruvate, and i3-acetamide) and very low affinity (i3-acrylate, i3-ethanol, indole) ligands of the murine AhR. Indole, skatole, tryptamine, i3-pyruvate, i3-acrylate, and i3-acetamide induced CYP1A1 mRNA in intestinal LS180 and HT-29 cells, but not in the AhR-knockout HT-29 variant. We observed a similar CYP1A1 induction pattern in primary human hepatocytes. The most AhR-active catabolites (indole, skatole, tryptamine, i3-pyruvate, i3-acrylate, i3-acetamide) elicited nuclear translocation of the AhR, followed by a formation of AhR-ARNT heterodimer and enhanced binding of the AhR to the CYP1A1 gene promoter. Collectively, we comprehensively characterized the interactions of gut microbial tryptophan catabolites with the AhR, which may expand the current understanding of their potential roles in intestinal health and disease.

• MeSH
• cytochrom P-450 CYP1A1 genetika   MeSH
• exprese genu MeSH
• indoly MeSH
• lidé MeSH
• ligandy MeSH
• metabolické sítě a dráhy MeSH
• multimerizace proteinu MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• promotorové oblasti (genetika) MeSH
• receptory aromatických uhlovodíků agonisté   metabolismus   MeSH
• reportérové geny MeSH
• střevní mikroflóra * účinky léků   MeSH
• transkripční faktory bHLH agonisté   metabolismus   MeSH
• tryptofan metabolismus   MeSH
• vazba proteinů MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH