SAYP and Bap170, subunits of the SWI/SNF remodeling complex, have the ability to support enhancer-dependent transcription when artificially recruited to the promoter on a transgene. We found that the phenomenon critically depends on two subunits of the Mediator kinase module, Med12 and Med13 but does not require the two other subunits of the module (Cdk8 and CycC) or other subunits of the core part of the complex. A cooperation of the above proteins in active transcription was also observed at endogenous loci, but the contribution of the subunits to the activity of a particular gene differed in different loci. The factors SAYP/Bap170 and Med12/Med13 did not form sufficiently stable interactions in the extract, and their cooperation was apparently local at regulatory elements, the presence of SAYP and Bap170 in a locus being necessary for stable recruitment of Med12 and Med13 to the locus. In addition to the above factors, the Nelf-A protein was found to participate in the process. The cooperation of the factors, independent of enzymatic activities of the complexes they are part of, appears to be a novel mechanism that maintains promoter activity and may be used in many loci of the genome. Extended intrinsically disordered regions of the factors were assumed to sustain the mechanism.
In Drosophila, the 20-hydroxyecdysone (20E) hormone regulates numerous essential biological processes. Here, we studied the contribution of 20E to the activity of immune signaling pathways and antimicrobial activity using the model Drosophila S2 cells. We found that while 20E alone has no essential effect on this system, pretreating S2 cells with 20E followed by incubation with Escherichia coli or Micrococcus luteus stimulates the induction of a limited number of antimicrobial peptide (AMP) genes, such as Diptericin (Dpt) and Drosomycin (Drs). Contrary to this, cells pretreatment with 20E simulates the activity of numerous Bacillus subtilis-induced AMP genes. Interestingly, it also significantly promotes the expression of components of both the Toll (Dif, Dorsal, etc.) and the IMD pathways (Relish, IMD, etc.) in the presence of Bacillus subtilis. Unexpectedly, simultaneous treatment of S2 cells by 20E and all three bacteria shows another pattern of activity and leads to a suppression of Drosocin (Dro) induction, in particular. Our study reveals that the contribution of 20E to immune genes activity varies for different genes and depends on the mode of 20E interplay with the pathogen and the nature of the pathogen itself
SWI/SNF protein complexes are evolutionarily conserved epigenetic regulators described in all eukaryotes. In metameric animals, the complexes are involved in all processes occurring in the nervous system, from neurogenesis to higher brain functions. On the one hand, the range of roles is wide because the SWI/SNF complexes act universally by mobilizing the nucleosomes in a chromatin template at multiple loci throughout the genome. On the other hand, the complexes mediate the action of multiple signaling pathways that control most aspects of neural tissue development and function. The issues are discussed to provide insight into the molecular basis of the multifaceted role of SWI/SNFs in cell cycle regulation, DNA repair, activation of immediate-early genes, neurogenesis, and brain and connectome formation. An overview is additionally provided for the molecular basis of nervous system pathologies associated with the SWI/SNF complexes and their contribution to neuroinflammation and neurodegeneration. Finally, we discuss the idea that SWI/SNFs act as an integration platform to connect multiple signaling and genetic programs.
The IMD and Toll signaling pathways in Drosophila melanogaster mediate the innate immune responses to Gram-negative and Gram-positive bacteria and fungi, respectively. Here we studied the involvement of the NF-κB transcription factor Relish, which is a mediator of the IMD pathway, in the humoral immune response to the Gram-positive bacteria Micrococcus luteus and Bacillus subtilis and the entomopathogenic fungus Metarhizium anisopliae, using D. melanogaster S2 cells as a model. Activation of Relish proteolysis was observed after S2 cell treatment with the control Gram-negative bacterium Escherichia coli. We found that M. luteus had also a noticeable effect on Relish activation, while B. subtilis and M. anisopliae effects were modest. Activation patterns of the genes encoding predominantly the IMD-pathway-dependent antimicrobial peptides (AMPs) and peptidoglycan recognition proteins (PGRPs), as well as the levels of Relish recruitment to the promoters of the genes, were found to be very similar in S2 cells treated with E. coli or M. luteus but were lower and differed in the case of B. subtilis and M. anisopliae. A Relish knockdown (KD) decreased the induction levels observed for all AMP and some PGRP genes in response to M. luteus treatment and the induction levels observed for several AMP genes after M. anisopliae and B. subtilis exposures. Therefore, our findings suggest that Relish plays a critical role in inducing the humoral immune response in Drosophila S2 cells, contributing primarily to the response against M. luteus and, to a lesser extent, to the responses against B. subtilis and M. anisopliae. ### Competing Interest Statement The authors have declared no competing interest.
Targeting the HIF1A and NF-kappa B pathways with pharmacological inhibitors or small interfering RNAs is one of the most promising aspects of cancer stem cell therapy. However, the influence of HIF1A and NF-kappa B modulators on downstream targets such as components of the Wnt/beta-catenin and Hedgehog pathways and EMT is still poorly understood. HeLa cells were treated with 10 and 50 mu M curcumin for 24 h, and the function of the Wnt/beta-catenin and Hedgehog pathways and EMT transcription factors were subsequently assessed using 14 RNAs expression qPCR-based analysis. We also applied siRNA-dependent HIF1A and RELA knockdown to investigate the influence of these pathways on the expression of the above RNAs along and in combination with curcumin treatment. At the higher concentration under basal conditions, curcumin suppressed most of the targets studied, while causing a significant increase in SNAI1 expression. Knockdown of HIF1A and RELA reduced the expression of Hedgehog pathway targets. In contrast to basal conditions, the expression of EMT transcription factors appeared to be increased after knockdown in response to 50 mu M curcumin. Curcumin significantly inhibited Wnt/beta-catenin, Hedgehog pathways and EMT transcription factor, while inducing an increase in SNAI1 gene expression, which may be part of cell adaptation systems. Knockdown of HIF1A and RELA revealed the strong dependence of Hedgehog target expression on HIF1A and NF-kappa B pathways. The activation status of HIF1A and NF-kappa B pathways determines the expression pattern of EMT transcription factors in HeLa cells.
Endoplasmic reticulum (ER) stress induction is a promising approach in anti-cancer technologies, and homocysteine may serve as an effective agent. Its usage, however, may only be possible following thorough testing for signaling side-effects. In three independent experiments, HeLa cells were treated with two concentrations of homocysteine (1 mM and 3 mM) or vehicle for 24 h to assess the expression of XBP1 transcript variants and functioning of the NFE2L2/ AP-1 and NF kappa B pathways. Homocysteine showed dose-dependent effectiveness in inducing ER stress and depleting total cellular thiols. The substance increased SESN2 expression when applied in the higher concentration. FTH1 expression differed between the two treatment groups. Surprisingly, no significant NF kappa B-associated effects were observed. Concluding on the results of the study, homocysteine can be used to effectively induce and manipulate ER stress and deplete cellular thiols. These effects are not necessarily accompanied by adverse effects in NF kappa B signaling.
In vivo studies involving humans have shown that the major beet root betaine trimethylglycine has cancer -preventing and cancer-suppressing effects in various malignancies. Yet, the molecular basis underlying these effects has been poorly studied.In this study, HeLa cells were treated with two concentrations of betaine (10 and 30 mg/mL) for 24 h, with subsequent assessment of functioning of the NFE2L2/AP-1, NFicB and HIF1A pathways using 22 RNAs expression qPCR-based analysis. Along this, we measured glucose import rate, mitochondrial function, cellular ROS, thiols and lipids content using flow cytometry.At the higher concentration, betaine disrupted (but not actually suppressed) the NFicB and HIF1A pathways functioning, while had no effect on the NFE2L2/AP-1 pathway. Among the net physiological effects, a slight increase in cellular phospholipids and a moderate decrease in mitochondrial function were observed under the higher concentration treatment conditions. Glucose import rate, triglycerides and thiols content, and ROS gen-eration were not affected.To conclude, betaine significantly deregulated NFicB and HIF1A pathways, while having only a modest in-fluence on metabolic parameters of the cells reflecting limited outcome of signaling disruption of the NFicB and HIF1A pathways. Additionally, challenges related to betaine dosing and side-effects accounting in clinical practice are worth considering. Generally, betaine properties render it a low-priority new era anti-cancer signaling agent, despite some human volunteers data existing and the revealed and confirmed MYC down -regulation.
Probiotics development for animal farming implies thorough testing of a vast variety of properties, including adhesion, toxicity, host cells signaling modulation, and immune effects. Being diverse, these properties are often tested individually and using separate biological models, with great emphasis on the host organism. Although being precise, this approach is cost-ineffective, limits the probiotics screening throughput and lacks informativeness due to the 'one model - one test - one property' principle. There is а solution coming from human-derived cells and in vitro systems, an extraordinary example of human models serving animal research. In the present review, we focus on the current outlooks of employing human-derived in vitro biological models in probiotics development for animal applications, examples of such studies and the analysis of concordance between these models and host-derived in vivo data. In our opinion, human-cells derived screening systems allow to test several probiotic properties at once with reasonable precision, great informativeness and less expenses and labor effort.
The ever-increasing biomedical application of magnetic nanoparticles (MNPs) implies increasing demand in their scalable and high-throughput production, with finely tuned and well-controlled characteristics. One of the options to meet the demand is microbial production by nanoparticles-synthesizing bacteria. This approach has several benefits over the standard chemical synthesis methods, including improved homogeneity of synthesis, cost-effectiveness, safety and eco-friendliness. There are, however, specific challenges emanating from the nature of the approach that are to be accounted and resolved in each manufacturing instance. Most of the challenges can be resolved by proper selection of the producing organism and optimizing cell culture and nanoparticles extraction conditions. Other issues require development of proper continuous production equipment, medium usage optimization and precursor ions recycling. This mini-review focuses on the related topics in microbial synthesis of MNPs: producing organisms, culturing methods, nanoparticles characteristics tuning, nanoparticles yield and synthesis timeframe considerations, nanoparticles isolation as well as on the respective challenges and possible solutions.
BACKGROUND:Berberine has multitudinous anti-cancer stem cells effects making it a highly promising candidate substance for the next-generation cancer therapy. However, berberine modes of action predispose it to significant side-effects that probably limit its clinical testing and application.MATERIALS AND METHODS:HeLa cells were treated with two concentrations of berberine (30 and 100 µM) for 24 hours to assess the functioning of the NFE2L2/AP-1, NFκB and HIF1A pathways using 22 RNAs expression qPCR-based analysis.RESULTS:Berberine effects appeared to be highly dose-dependent, with the lower concentration being capable of suppressing the NFκB functioning and the higher concentration causing severe signaling side-effects seen in the HIF1A pathway and the NFE2L2 sub-pathways, and especially and more importantly in the AP-1 sub-pathway.CONCLUSION:The results of the study suggest that berberine has clinically valuable anti-NFκB effects however jeopardized by its side effects on the HIF1A and especially NFE2L2/AP-1 pathways, its therapeutic window phenomenon and its cancer type-specificity. These, however, may be ameliorated using the cocktail approach, provided there is enough data on signaling effects of berberine.
Although NFE2L2 transcription factor is considered to make the most significant contribution to the NFE2L2/AP-1-pathway-dependent antioxidants regulation in the human cell, AP-1 has the potential to provide significant backup and even play an equal role in the cell. Considering this, the present study is focused on revealing how JUN, an AP-1 component, and NFE2L2 contribute to regulation of four target genes containing AREs with embedded TREs-SQSTM1, FTH1, HMOX1 and CBR3 and to cellular oxidative status in general in basal conditions and under pro-oxidative influence. NFE2L2 and JUN were down-regulated in HeLa cells using siRNA-mediated knockdown approach. These cells were subsequently exposed to 400 µM hydrogen peroxide in the medium or equal volume of sterile water. They revealed some evidence of both backup functioning and competing between the two factors. Importantly, JUN demonstrated a high level of participation (inc. as a negative regulator) in functioning of the classic NFE2L2 targets and in cellular oxidative status establishment in general. One of the key findings was a dramatic increase in JUN expression following NFE2L2 knockdown in basal conditions. The both AP-1 and NFE2L2 sub-pathways equally determine the outcome of the NFE2L2/AP-1 pathway activation induced by various stimuli, and the outcome is stimulus type- and stimulus-intensity-specific and results from either of the two eventually dominating sub-pathways.
Dihetaryls containing superelectrophilic and π-excessive heterocycles were synthesized by the nucleophilic aromatic substitution and cycloaddition. The structures of the compounds and the mechanism of 1,3- N -oxide tautomerism were studied by NMR spectroscopy, X-ray diffraction, and quantum chemical methods. The ability of these compounds to initiate SOX induction, which is probably due to the in vivo generation of nitrogen( ii ) oxide, was quantified using genetically engineered E. coli -based lux biosensors. 7-(1-Methylpyrrol-3-yl)-4,6-dinitrobenzofuroxan is the most active inducer, which is an order of magnitude more effective than nitroglycerin used as the reference compound. The absence of toxicity was established using the E. coli MG 1655 biosensor (pXen7-lux). The DNA protective effect of this leading compound was confirmed using the E. coli MG 1655 biosensor (pRecA-lux).
According to modern molecular biology concepts, uric acid and homocysteine are activators and participants prooxidant positive feedback loop that also includes xanthine oxidoreductase and NADP∙H-oxidase complexes as direct prooxidant agents. Due to the physiological and biochemical features, the kidney may be the organ that is the most exposed to this contour effects. The present review focuses on nephrological implications of biochemical, physiological and interactomic properties of the circuit and its components.