Inhibition Of RNA Polymerase Research Articles

Reciprocal regulation of mTORC1 signaling and ribosomal biosynthesis determines cell cycle progression in activated T cells.

Ribosomal biosynthesis in nucleoli is an energy-demanding process driven by all RNA polymerases and hundreds of auxiliary proteins. We investigated how this process is regulated in activated T lymphocytes by T cell receptor (TCR) signals and the multiprotein complexes mTORC1 and mTORC2, both of which contain the kinase mTOR. Deficiency in mTORC1 slowed the proliferation of T cells, with further delays in each consecutive division, an effect not seen with deficiency in mTORC2. mTORC1 signaling was stimulated by components of conventional TCR signaling, and, reciprocally, TCR sensitivity was decreased by mTORC1 inhibition. The substantial increase in the amount of RNA per cell induced by TCR activation was reduced by 50% by deficiency in mTORC1, but not in mTORC2 or in S6 kinases 1 and 2, which are activated downstream of mTORC1. RNA-seq data showed that mTORC1 deficiency reduced the abundance of all RNA biotypes, although rRNA processing was largely intact in activated T cells. Imaging cytometry with FISH probes for nascent pre-rRNA revealed that deletion of mTORC1, but not that of mTORC2, reduced the number and expansion of nucleolar sites of active transcription. Protein translation was consequently decreased by 50% in the absence of mTORC1. Inhibiting RNA polymerase I blocked not only proliferation but also mTORC1 signaling. Our data show that TCR signaling, mTORC1 activity, and ribosomal biosynthesis in the nucleolus regulate each other during biomass production in clonally expanding T cells.

Revolutionizing Influenza Treatment: A Deep Dive into Targeted Drug Delivery Systems.

Influenza, a highly transmissible respiratory infection caused by influenza viruses A and B, poses a persistent threat to global public health due to its high mutation rate, ability to develop resistance to existing antiviral drugs, and capacity for rapid spread. Current treatment options, including four main classes of antiviral agents-adamantanes, neuraminidase inhibitors, RNA-dependent RNA polymerase inhibitors, and polymerase acidic endonuclease inhibitors- are limited by the emergence of drug-resistant viral strains, non-specific drug distribution, and adverse side effects. Moreover, the effectiveness of traditional vaccines is often compromised by antigenic drift and shift, necessitating the development of alternative therapeutic strategies. This review comprehensively explores the potential of novel targeted drug delivery systems to address these limitations and improve influenza management. Nanotechnology-based platforms, including lipid-based, polymer-based, inorganic, and hybrid nanoparticles, offer enhanced drug delivery through improved bioavailability, targeted action, and controlled release, thus minimizing systemic toxicity and optimizing therapeutic outcomes. Inhalation delivery systems such as dry powder inhalers (DPIs), nebulizers, and nanotechnology-based inhalation formulations provide direct delivery of antiviral agents to the respiratory tract, ensuring rapid onset of action with reduced systemic side effects. Transdermal delivery methods, including microneedle patches and hydrogel-based systems, offer non-invasive alternatives that enhance patient compliance and allow for sustained drug release. Furthermore, this review discusses recent innovations, such as responsive drug delivery systems and multifunctional nanoparticles capable of simultaneous delivery of multiple therapeutic agents, representing a significant advancement in the fight against influenza. These novel approaches promise improved targeting and efficacy and enable personalized treatment strategies, enhancing patient outcomes in both seasonal flu and pandemic scenarios. Integrating these advanced drug delivery systems into clinical practice could revolutionize the management of influenza, offering a promising pathway toward more effective and safer therapies.

Detection and quantification of Amatoxin in wild mushrooms from North-East India using HPLC-PDA method for food safety purposes

Misidentification and ingestion of poisonous mushrooms pose significant threats to food safety, particularly in Mizoram, India, where over ten fatalities due to mushroom poisoning have been reported in the past decade (2013-2023). This study aimed to address this critical issue by identifying and quantifying the cause of death due to consumption of wild mushroom from Champhai district, Mizoram, India and to test the reliability of HPLC-PDA for detection and quantification of amatoxins. HPLC-PDA confirmed the presence of α-amanitin in Amanita virosa and Amanita bisporigera in the samples. α-amanitin is a water-soluble, heat-stable, and highly toxic cyclic octapeptide present in the genus Amanita, which includes Amanita phalloides, Amanita verna, and Amanita virosa. Amanitin cytotoxicity arises from the inhibition of RNA polymerases, namely RNA polymerase II, which obstructs mRNA production in kidney and liver cells. Validation of the method demonstrated good precision and accuracy, with LOD and LOQ values of 88 ng g-1 and 210 ng g-1, respectively. The method was successfully applied to quantify α-amanitin in ten wild mushroom samples, revealing its presence only in Amanita virosa (1.17 mg g-1) and Amanita bisporigera (1.91 mg g-1) species. These findings underscore the importance of accurate α-amanitin detection methods in ensuring food safety and public health, particularly in regions prone to mushroom poisoning incidents. It is noteworthy that this study marks the initial exploration for detection and quantification of α-amanitin from poisonous mushrooms found in the wild regions of Champhai district in Mizoram, representing the first report of such in the area.

Interaction between Molnupiravir and noble metal substrates in SERS detection: A DFT method and Raman characteristic study

Molnupiravir, a nucleoside analogue (EIDD-2801), is an RNA polymerase inhibitor that effectively treats infections caused by novel coronaviruses and can be administered orally. Therefore, it is necessary to monitor the distribution of Molnupiravir in vivo after oral administration. Surface-enhanced Raman spectroscopy (SERS) is a suitable detection method, so it is necessary to understand the interaction between Molnupiravir and noble metal nanoparticles in the SERS effect. Therefore, we used density functional theory combined with surface-enhanced Raman spectroscopy to investigate the interaction between Molnupiravir and noble metal/composite nanoparticles in the SERS effect. To study the interaction sites of Molnupiravir and the substrate in the SERS effect, the molecular electrostatic potential (MEP) of Molnupiravir was calculated. Considering the significant role of binding energy in studying molecular docking, the binding energy between Molnupiravir and Metal6 (Au6, Ag6, Au3Ag3) atomic clusters was calculated. The calculated results of the frontier orbitals and relevant molecular parameters of Molnupiravir and Molnupiravir-Metal6 complexes reveal the changes in the molecular properties of Molnupiravir in the SERS effect. Finally, the theoretical Raman spectra differences between Molnupiravir and complexes were compared and analyzed, and the adsorption structure of Molnupiravir on the substrate surface was determined based on the surface selection rules of SERS. The research results will provide insights into the interaction between Molnupiravir and the substrate in the SERS effect, and also offer theoretical support for the application of SERS methods in biomedical detection.

Evaluation of A Non-Nucleoside Inhibitor of the RSV RNA-Dependent RNA Polymerase in Translatable Animals Models

Respiratory Syncytial Virus (RSV) causes severe respiratory infections and concomitant disease resulting in significant morbidity and mortality in infants, elderly, and immunocompromised adults. Vaccines, monoclonal antibodies, and small molecule antivirals are now either available, or in development, to prevent and treat RSV infections. Although, rodent and non-rodent preclinical animal models have been used to evaluate these emerging agents there is still a need to improve our understanding of the pharmacokinetic (PK)-pharmacodynamic (PD) relationships, within and between animal models to enable better design of human challenge studies and clinical trials. Herein, we report a PKPD evaluation of MRK-1, a novel small molecule non-nucleoside inhibitor of the RSV L polymerase protein, in the semi-permissive cotton rat and African green monkey models of RSV infection. These studies demonstrate a strong relationship between in vitro activity, in vivo drug exposure, and pharmacodynamic efficacy as well as revealing limitations of the cotton rat RSV model. Additionally, we report unexpected horizontal transmission of human RSV between co-housed African green monkeys, as well as a lack of drug specific resistant mutant generation. Taken together these studies further our understanding of these semi-permissive animal models and offer the potential for expansion of their preclinical utility in evaluating novel RSV therapeutic agents.

Recent Advancements in the Delivery of Therapeutic Agents Targeting RNA-dependent RNA Polymerase of SARS-CoV-2.

This study aimed to undertake a complete evaluation and analysis of all known data on RNA-dependent RNA polymerase (RdRp) inhibitors, concentrating on their safety, efficacy, and current improvements in the delivery of therapeutic drugs targeting RdRp of SARS-CoV-2. The work has attempted to emphasise the necessity for future research into the development of nanocarrier-based targeted drug delivery methods for RdRp inhibitors in the treatment of COVID-19. In December 2019, a novel SARS-- CoV-2 strain was discovered in Wuhan, China. SARS-CoV-2 is transferable among humans and has caused a global pandemic. The rapid global outbreak of SARS-CoV-2 and numerous deaths caused because of coronavirus disease (COVID-19) prompted the World Health Organization to announce a pandemic on March 12, 2020. COVID-19 is becoming a key concern that has a significant impact on an individual's life status. RdRp inhibitors are major pharmaceutical agents used in the treatment of COVID-19, which have various undesirable side effects, a greater risk of recurrence, lower bioavailability, as well as a lack of targeted therapy. Hence, the present article has provided a review on all known data on RdRp inhibitors, safety, and efficacy, and recent advances in the delivery of therapeutic agents targeting RdRp of SARS-CoV-2. An analysis has been done using a scientific data search engine, such as the National Center for Biotechnology Information (NCBI/PubMed), Science Direct, Google Scholar, WIPO, Lens, etc. The information has emphasized the need for more research into the safety, efficacy, and development of nanocarrier-based targeted drug delivery systems for RdRp inhibitors in the treatment of COVID-19.

Bioprospection for antiviral compounds from selected medicinal plants against RNA polymerase of rotavirus A using molecular modelling and density functional theory

Rotavirus A (RVA) infection remains a significant global health challenge, especially in developing countries, causing severe dehydrating diarrhoea in children under five years of age. Despite the availability of four World Health Organization (WHO) pre-qualified vaccines, their availability, particularly in low-income countries, pose significant challenges. Currently, there are no specific anti-rotaviral medications hence, the urgency to develop novel therapeutics against rotavirus infection. Thus, this study explored the potential of secondary metabolites of Spondias mombin, Macaranga barteri and Dicerocaryum eriocarpum as novel inhibitors of the RNA-dependent RNA polymerase (VP1) of rotavirus A using computational techniques. Pharmacokinetics parameters were adopted to screen the top 20 metabolites with high affinity for the target, initially identified through a docking study. Furthermore, the ability of the resulting compounds to modulate the investigated target was assessed using molecular dynamics (MD) simulation, while density functional theory (DFT) calculations were conducted to predict the molecular properties of the top-ranked compounds. Except for ellagic acid hexoside (-33.14 kcal/mol), all the leads had higher binding free energy values relative to sofosbuvir (-36.58 kcal/mol) following a 120 ns MD simulation. Overall, the resulting complexes with the lead compounds demonstrated acceptable stability, reduced flexibility and compactness, with spiraeoside (-51.02 kcal/mol) displaying more favourable thermodynamics metrics, albeit with a lesser binding free energy relative to chrysoeriol 7-glucuronide (-58.36 kcal/mol). The binding free energy and thermodynamic parameters of the top-hit compounds could be attributed to their respective bond interactions and molecular orbital properties except chrysoeriol 7-glucuronide, with a need for additional structural adjustment to enhance its thermodynamic properties. Thus, these findings indicate the potential modulatory ability of the lead compounds against the VP1 protein of RVA, underscoring the importance of further in vitro and in vivo studies to validate the predicted activity, and ongoing efforts are being made to pursue this line of investigation.

In Silico Evaluation of HIV Protease and RNA Polymerase Inhibitors as Potential COVID-19 Therapeutics.

The COVID-19 coronavirus, also known as the acute respiratory syndrome coronavirus, emerged as a significant global health concern. First identified in Wuhan, China, in December 2019, the virus rapidly spread to over 187 countries due to its high transmissibility. Until an effective treatment or vaccine is developed, preventive measures remain the only mandatory strategy to curb person-to-person transmission. The study aimed to explore potential therapeutic options for COVID-19 by repurposing existing drugs. Specifically, the objective was to evaluate a library of clinically approved or investigational antiviral compounds through docking studies to identify candidates with high binding affinity to COVID-19 proteins. The study employed molecular docking techniques using the Maestro interface (Schrodinger Suite, LLC, NY) to assess the interaction of selected compounds with various COVID-19 protein targets. A total of 15 compounds were analyzed for their binding potential to multiple forms of the virus's proteins. The docking studies revealed that several compounds, particularly HIV protease inhibitors and RNA-dependent RNA polymerase inhibitors, demonstrated strong binding affinities to key COVID-19 enzymes. These interactions suggest their potential as therapeutic candidates for COVID-19 treatment. The findings from this drug repurposing study highlight the potential of certain existing antiviral agents in the treatment of COVID-19. The identified compounds could serve as promising candidates for further investigation in the ongoing battle against the coronavirus pandemic.

Targeting POLRMT by IMT1 inhibits colorectal cancer cell growth

This study investigates the potential anti-colorectal cancer (CRC) activity of IMT1, a novel specific inhibitor of mitochondrial RNA polymerase (POLRMT). Single-cell RNA sequencing data reveal that POLRMT is overexpressed in CRC cells. Additionally, elevated POLRMT expression was observed in local CRC tissues and cells, while its expression remained relatively low in colon epithelial tissues and cells. IMT1 significantly inhibited colony formation, cell viability, proliferation, cell cycle progression, and migration in both primary and immortalized CRC cells. Furthermore, IMT1 induced apoptosis and cell death in CRC cells. The inhibition of POLRMT by IMT1 disrupted mitochondrial functions in CRC cells, leading to mitochondrial depolarization, oxidative damage, and decreased ATP levels. Using targeted shRNA to silence POLRMT closely mirrored the effects of IMT1, showing robust anti-CRC cell activity. Crucially, the efficacy of IMT1 was diminished in CRC cells with silenced POLRMT. Contrarily, boosting POLRMT expression externally by a lentiviral construct promoted the proliferation and migration of CRC cells. Importantly, treatment with IMT1 or silencing POLRMT in primary colon cancer cells decreased the phosphorylation of Akt1-S6K1, whereas overexpression of POLRMT had the opposite effect. In nude mice, orally administering IMT1 potently restrained primary colon cancer xenograft growth. IMT1 suppressed POLRMT activity, disrupted mitochondrial function, hindered Akt-mTOR activation, and prompted apoptosis within the xenograft tissues. In addition, IMT1 administration suppressed lung metastasis of primary colon cancer cells in nude mice. These combined results highlight the robust anti-CRC activity of IMT1 by specifically targeting POLRMT.

Design of novel and highly selective SARS-CoV-2 main protease inhibitors.

We have synthesized a novel and highly selective severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) main protease peptide mimetic inhibitor mimicking the replicase 1ab recognition sequence -Val-Leu-Gln- and utilizing a cysteine selective acyloxymethyl ketone as the electrophilic warhead to target the active site Cys145. Utilizing a constrained cyclic peptide that locks the conformation between the P3 (Val) and P2 (Leu) residues, we identified a highly selective inhibitor that fills the P2 pocket occupied by the leucine residue sidechain of PF-00835231 and the dimethyl-3-azabicyclo-hexane motif in nirmatrelvir (PF-07321332). This strategy resulted in potent and highly selective Mpro inhibitors without inhibiting essential host cathepsin cysteine or serine proteases. The lead prototype compound 1 (MPro IC50 = 230 ± 18 nM) also inhibits the replication of multiple SARS-CoV-2 variants in vitro, including SARS-CoV-2 variants of concern, and can synergize at lower concentrations with the viral RNA polymerase inhibitor, remdesivir, to inhibit replication. It also reduces SARS-CoV-2 replication in SARS-CoV-2 Omicron-infected Syrian golden hamsters without obvious toxicities, demonstrating in vivo efficacy. This novel lead structure provides the basis for optimization of improved agents targeting evolving SARS-CoV-2 drug resistance that can selectively act on Mpro versus host proteases and are less likely to have off-target effects due to non-specific targeting. Developing inhibitors against the active site of the main protease (Mpro), which is highly conserved across coronaviruses, is expected to impart a higher genetic barrier to evolving SARS-CoV-2 drug resistance. Drugs that selectively inhibit the viral Mpro are less likely to have off-target effects warranting efforts to improve this therapy.

Design of RNA Polymerase Inhibitors as Therapeutics for Tuberculous Meningitis.

Tuberculosis is an infectious disease caused by Mycobacterium tuber-culosis. The current treatment protocols for pulmonary tuberculosis are quite effective, even though the treatment requires 3-6 months. The current treatment protocols for extrapulmonary tuberculosis are based on the same drugs that are used for pulmonary tuberculosis. However, the success rates are much lower for certain types of extrapulmonary tuberculosis, such as tubercu-lous meningitis. Tuberculous meningitis is one of the very few diseases attributable to bacteria that have a very high short-term mortality rate among diagnosed patients, even after treatment with antibiotics that are effective for pulmonary tuberculosis. For example, rifampicin is highly effective for the treatment of pulmonary tuberculosis, but its effectiveness for the treatment of tuberculous meningitis is much lower. The reason for the lower effectiveness of rifampicin against tuberculous meningitis is that it has low Blood-Brain Barrier (BBB) permeability, which results in lower concentrations of the drug at the required sites in the central nervous system. In this work, ligands having increased BBB permeability and pharmacokinetic and pharmacodynamic properties, either similar to or better than that of rifampicin, have been de-signed. The BBB permeability of the designed molecules was assessed by using pkCSM, a ma-chine-learning model. Pharmacokinetic properties, drug-likeness, and synthesizability were as-sessed by using SWISS-MODEL. The binding affinity of the designed drugs was assessed by using AutoDock Vina. A customized scoring function, StWN score, was used for a quantitative weighted assessment of all the properties of interest to rank the designed molecules. In this study, drug-like ligands have been designed that have been predicted to have high BBB permeability as well as high affinity for RNA polymerase  ofMycobacterium tuberculosis. The best ligands generated by the tools employed were selected as potential drugs to address the current need for better options for the treatment of tuberculous meningitis.

Application of seven tools for evaluation of greenness of chromatographic methods for Remdesivir analysis

Green analytical chemistry is concerned with making analytical techniques more secure and environmentally friendly. A crucial aspect of this approach is the assessment of the greenness of analytical methods. Remdesivir, a SARS-CoV-2 nucleotide analog RNA polymerase inhibitor, has been authorized by USFDA as the initial course of therapy for hospitalized COVID-19 patients. The proposed study evaluates greenness of several reported chromatographic methods for estimation of Remdesivir using seven different tools namely ComplexGAPI, BAGI, AGREE, AGREEprep, AMGS, ChlorTox and RGBfast.

Release of mitochondrial dsRNA into the cytosol is a key driver of the inflammatory phenotype of senescent cells

The escape of mitochondrial double-stranded dsRNA (mt-dsRNA) into the cytosol has been recently linked to a number of inflammatory diseases. Here, we report that the release of mt-dsRNA into the cytosol is a general feature of senescent cells and a critical driver of their inflammatory secretome, known as senescence-associated secretory phenotype (SASP). Inhibition of the mitochondrial RNA polymerase, the dsRNA sensors RIGI and MDA5, or the master inflammatory signaling protein MAVS, all result in reduced expression of the SASP, while broadly preserving other hallmarks of senescence. Moreover, senescent cells are hypersensitized to mt-dsRNA-driven inflammation due to their reduced levels of PNPT1 and ADAR1, two proteins critical for mitigating the accumulation of mt-dsRNA and the inflammatory potency of dsRNA, respectively. We find that mitofusin MFN1, but not MFN2, is important for the activation of the mt-dsRNA/MAVS/SASP axis and, accordingly, genetic or pharmacologic MFN1 inhibition attenuates the SASP. Finally, we report that senescent cells within fibrotic and aged tissues present dsRNA foci, and inhibition of mitochondrial RNA polymerase reduces systemic inflammation associated to senescence. In conclusion, we uncover the mt-dsRNA/MAVS/MFN1 axis as a key driver of the SASP and we identify novel therapeutic strategies for senescence-associated diseases.

Etravirine Prevents West Nile Virus and Chikungunya Virus Infection Both In Vitro and In Vivo by Inhibiting Viral Replication.

Diseases transmitted by arthropod-borne viruses such as West Nile virus (WNV) and chikungunya virus (CHIKV) pose threat to global public health. Unfortunately, to date, there is no available approved drug for severe symptoms caused by both viruses. It has been reported that reverse transcriptase inhibitors can effectively inhibit RNA polymerase activity of RNA viruses. We screened the anti-WNV activity of the FDA-approved reverse transcriptase inhibitor library and found that 4 out of 27 compounds showed significant antiviral activity. Among the candidates, etravirine markedly inhibited WNV infection in both Huh 7 and SH-SY5Y cells. Further assays revealed that etravirine inhibited the infection of multiple arboviruses, including yellow fever virus (YFV), tick-borne encephalitis virus (TBEV), and CHIKV. A deeper study at the phase of action showed that the drug works primarily during the viral replication process. This was supported by the strong interaction potential between etravirine and the RNA-dependent RNA polymerase (RdRp) of WNV and alphaviruses, as evaluated using molecular docking. In vivo, etravirine significantly rescued mice from WNV infection-induced weight loss, severe neurological symptoms, and death, as well as reduced the viral load and inflammatory cytokines in target tissues. Etravirine showed antiviral effects in both arthrophlogosis and lethal mouse models of CHIKV infection. This study revealed that etravirine is an effective anti-WNV and CHIKV arbovirus agent both in vitro and in vivo due to the inhibition of viral replication, providing promising candidates for clinical application.

CDK9 inhibition constrains multiple oncogenic transcriptional and epigenetic pathways in prostate cancer

BackgroundCyclin-dependent kinase 9 (CDK9) stimulates oncogenic transcriptional pathways in cancer and CDK9 inhibitors have emerged as promising therapeutic candidates.MethodsThe activity of an orally bioavailable CDK9 inhibitor, CDKI-73, was evaluated in prostate cancer cell lines, a xenograft mouse model, and patient-derived tumor explants and organoids. Expression of CDK9 was evaluated in clinical specimens by mining public datasets and immunohistochemistry. Effects of CDKI-73 on prostate cancer cells were determined by cell-based assays, molecular profiling and transcriptomic/epigenomic approaches.ResultsCDKI-73 inhibited proliferation and enhanced cell death in diverse in vitro and in vivo models of androgen receptor (AR)-driven and AR-independent models. Mechanistically, CDKI-73-mediated inhibition of RNA polymerase II serine 2 phosphorylation resulted in reduced expression of BCL-2 anti-apoptotic factors and transcriptional defects. Transcriptomic and epigenomic approaches revealed that CDKI-73 suppressed signaling pathways regulated by AR, MYC, and BRD4, key drivers of dysregulated transcription in prostate cancer, and reprogrammed cancer-associated super-enhancers. These latter findings prompted the evaluation of CDKI-73 with the BRD4 inhibitor AZD5153, a combination that was synergistic in patient-derived organoids and in vivo.ConclusionOur work demonstrates that CDK9 inhibition disrupts multiple oncogenic pathways and positions CDKI-73 as a promising therapeutic agent for prostate cancer, particularly aggressive, therapy-resistant subtypes.

CX-5461 ameliorates disease in lupus-prone mice by triggering B-cell ferroptosis via p53-SLC7A11-ALOX12 pathway

CX-5461, a first-in-class compound, is widely recognized as a selective inhibitor of RNA polymerase I. Recently, it has been reported to possess novel immunosuppressive properties with significant therapeutic effects in transplantation immune rejection. However, the potential use of CX-5461 for Systemic Lupus Erythematosus (SLE) treatment remains unknown. In this study, we elucidated the mechanism underlying the therapeutic efficacy of CX-5461 in lupus. Our findings demonstrated that CX-5461 selectively targets B cells and effectively reduces the proportions of B cells, germinal center B cells, and plasma cells in MRL/MPJ-Faslpr and Resiquimod (R848)-induced lupus mice. Molecular studies revealed that CX-5461 modulates CD36-Acyl-CoA Synthetase Long Chain Family Member 4 (ACSL4)-mediated glycerolipid metabolism in B cells, triggering ferroptosis through the p53- Solute Carrier Family 7 Member 11 (SLC7A11)- Arachidonate 12-Lipoxygenase (ALOX12) pathway, thereby decreasing IgG and Anti-Double-Stranded Deoxyribonucleic Acid (dsDNA) antibody levels and attenuating lupus. Collectively, these results suggest that CX-5461 holds promise as an effective candidate for targeted therapy against lupus.

Abstract Tu109: Sirt1 inhibits the Sub1-induced RNA polymerase II recruitment to metabolic gene promoters during pressure overload

Downregulation of genes involved in mitochondrial energy production is a hallmark of heart failure, which associates with inhibition of RNA polymerase II (Pol II) recruitment to the gene promoters. Sirt1 is a protein deacetylase regulating transcription of metabolic genes. However, how Sirt1 regulates metabolic genes in heart failure is controversial. Here we show that Sirt1 promotes pressure overload (PO)-induced downregulation of metabolic genes possibly through inhibition of the Pol II recruitment. Cardiac-specific Sirt1 overexpression in mice (Tg-Sirt1) promoted PO-induced cardiac dysfunction (Ejection fraction (%): wild type (WT) sham 76, WT PO 68, Tg-Sirt1 sham 76, Tg-Sirt1 PO 48*, p<0.05 vs WT PO) and downregulation of metabolic genes, including Idh3a (relative Idh3a mRNA levels; WT Sham 1.0, WT PO 0.55, Tg-Sirt1 0.98, Tg-Sirt1 PO 0.41, p<0.05 vs WT PO). In cultured cardiomyocytes, Sirt1 overexpression suppressed metabolic enzymes, reporter gene activity driven by endogenous metabolic gene promoters, and mitochondrial respiration. Chromatin immunoprecipitation and in vitro DNA binding assays, using 500bp of endogenous Idh3a promoter sequence, showed that Sirt1 inhibits the Pol II recruitment to the promoter. Unbiased screening using mass spectrometry identified Sub1 as a Sirt1 binding protein. Sub1 is an evolutionally conserved DNA binding protein that mediates the Pol II recruitment via the preinitiation complex formation. We confirmed direct binding of Sub1 to the Sirt1 catalytic domain (235-499aa) and Sub1-dependent Sirt1 recruitment to the Idh3a promoter using the in vitro reconstitution system. In vitro DNA binding assays with the Idh3a promoter sequence demonstrated that Sirt1 inhibits preinitiation complex formation, but not Sub1 recruitment. These results suggest that Sirt1 inhibits Sub1-induced preinitiation complex formation, thereby suppressing transcription of metabolic genes in the failing heart.

Development and validation of Mayaro virus with luciferase reporter genes as a tool for antiviral assays

Arboviruses are etiological agents in an extensive group of emerging diseases with great clinical relevance in Brazil, due to the wide distribution of their vectors and the favorable environmental conditions. Among them, the Mayaro virus (MAYV) has drawn attention since its emergence as the etiologic agent of Mayaro fever, a highly debilitating disease. To study viral replication and identify new drug candidates, traditional antiviral assays based on viral antigens and/or plaque assays have been demonstrating low throughput, making it difficult to carry out larger-scale assays. Therefore, we developed and characterized two DNA-launched infectious clones reporter viruses based on the MAYV strain BeAr 20290 containing the reporter genes of firefly luciferase (FLuc) and nanoluciferase (NLuc), designated as MAYV-firefly and MAYV-nanoluc, respectively. The viruses replicated efficiently with similar properties to the parental wild-type MAYV, and luminescence expression levels reflected viral replication. Reporter genes were also preserved during passage in cell culture, remaining stably expressed for one round of passage for MAYV-firefly and three rounds for MAYV-nanoluc. Employing the infectious clone, we described the effect of Rimantadine, an FDA-approved Alzheimer's drug, as a repurposing agent for MAYV but with a broad-spectrum activity against Zika virus infection. Additionally, we validated MAYV-nanoluc as a tool for antiviral drug screening using the compound EIDD-2749 (4′-Fluorouridine), which acts as an inhibitor of alphavirus RNA-dependent RNA polymerase.

Erratum for Balthazar et al., "A laboratory-based predictive pathway for the development of Neisseria gonorrhoeae high-level resistance to corallopyronin A, an inhibitor of bacterial RNA polymerase".

Erratum for Balthazar et al., "A laboratory-based predictive pathway for the development of Neisseria gonorrhoeae high-level resistance to corallopyronin A, an inhibitor of bacterial RNA polymerase".

Covalent Organic Framework-Based Theranostic Platforms for Restricting H1N1 Influenza Virus Infection.

Influenza A (H1N1) virus is a highly contagious respiratory disease that causes severe illness and death. Vaccines and antiviral drugs are limited by viral variation and drug resistance, so developing efficient integrated theranostic options appears significant in anti-influenza virus infection. In this study, we designed and fabricated covalent organic framework (COF) based theranostic platforms (T705@DATA-COF-Pro), which was composed of an RNA polymerase inhibitor (favipiravir, T705), the carboxyl-enriched COF (DATA-COF) nano-carrier and Cy3-labeled single DNA (ssDNA) probe. The multi-porosity COF core provided an excellent micro-environment and smooth delivery for T705. The ssDNA probe coating bound to the nucleic acids of H1N1 selectively, thus controlling drug release and allowing fluorescence imaging. The combination of COF and probe triggered the synergism, promoting drug further therapeutic outcomes. With the aid of T705@DATA-COF-Pro platforms, the H1N1-infected mouse models lightly achieved diagnosis and significantly prolonged survival. This research underscores the distinctive benefits and immense potential of COF materials in nano-preparations for virus infection, offering novel avenues for the detection and treatment of H1N1 virus infection.