Thiophene-fused γ-lactams inhibit the SARS-CoV-2 main protease via reversible covalent acylation.

Enzyme inhibitors working by O-acylation of nucleophilic serine residues are of immense medicinal importance, as exemplified by the ß-lactam antibiotics. By contrast, inhibition of nucleophilic cysteine enzymes by S-acylation has not been widely exploited for medicinal applications. The SARS-CoV-2 main protease (Mpro) is a nucleophilic cysteine protease and a validated therapeutic target for COVID-19 treatment using small-molecule inhibitors. The clinically used Mpro inhibitors nirmatrelvir and simnotrelvir work via reversible covalent reaction of their electrophilic nitrile with the Mpro nucleophilic cysteine (Cys145). We report combined structure activity relationship and mass spectrometric studies revealing that appropriately functionalized γ-lactams can potently inhibit Mpro by reversible covalent reaction with Cys145 of Mpro. The results suggest that γ-lactams have potential as electrophilic warheads for development of covalently reacting small-molecule inhibitors of Mpro and, by implication, other nucleophilic cysteine enzymes.

NAT10, an RNA Cytidine Acetyltransferase, Regulates Ferroptosis in Cancer Cells.

Recently, we reported that N-acetyltransferase 10 (NAT10) regulates fatty acid metabolism through ac4C-dependent RNA modification of key genes in cancer cells. During this work, we noticed ferroptosis as one of the most negatively enriched pathways among other pathways in NAT10-depleted cancer cells. In the current work, we explore the possibility of whether NAT10 acts as an epitranscriptomic regulator of the ferroptosis pathway in cancer cells. Global ac4C levels and expression of NAT10 with other ferroptosis-related genes were assessed via dotblot and RT-qPCR, respectively. Flow cytometry and biochemical analysis were used to assess oxidative stress and ferroptosis features. The ac4C-mediated mRNA stability was conducted using RIP-PCR and mRNA stability assay. Metabolites were profiled using LC-MS/MS. Our results showed significant downregulation in expression of essential genes related to ferroptosis, namely SLC7A11, GCLC, MAP1LC3A, and SLC39A8 in NAT10-depleted cancer cells. Further, we noticed a reduction in cystine uptake and reduced GSH levels, along with elevated ROS, and lipid peroxidation levels in NAT10-depleted cells. Consistently, overproduction of oxPLs, as well as increased mitochondrial depolarization and decreased activities of antioxidant enzymes, support the notion of ferroptosis induction in NAT10-depleted cancer cells. Mechanistically, a reduced ac4C level shortens the half-life of GCLC and SLC7A11 mRNA, resulting in low levels of intracellular cystine and reduced GSH, failing to detoxify ROS, and leading to increased cellular oxPLs, which facilitate ferroptosis induction. Collectively, our findings suggest that NAT10 restrains ferroptosis by stabilizing the SLC7A11 mRNA transcripts in order to avoid oxidative stress that induces oxidation of phospholipids to initiate ferroptosis.

Multi-level interaction between HIF and AHR transcriptional pathways in kidney carcinoma.

Hypoxia-inducible factor (HIF) and aryl hydrocarbon receptor (AHR) are members of the bHLH-PAS family of transcription factors that underpin cellular responses to oxygen and to endogenous and exogenous ligands, respectively, and have central roles in the pathogenesis of renal cancer. Composed of heterodimers, they share a common HIF-1ß/ARNT subunit and similar DNA-binding motifs, raising the possibility of crosstalk between the two transcriptional pathways. Here, we identify both general and locus-specific mechanisms of interaction between HIF and AHR that act both antagonistically and cooperatively. Specifically, we observe competition for the common HIF-1ß/ARNT subunit, in cis synergy for chromatin binding, and overlap in their transcriptional targets. Recently, both HIF and AHR inhibitors have been developed for the treatment of solid tumours. However, inhibition of one pathway may promote the oncogenic effects of the other. Therefore, our work raises important questions as to whether combination therapy targeting both of these pro-tumourigenic pathways might show greater efficacy than targeting each system independently.

BTYNB, an inhibitor of RNA binding protein IGF2BP1 reduces proliferation and induces differentiation of leukemic cancer cells.

Leukemia is a group of diseases characterized by altered growth and differentiation of lymphoid or myeloid progenitors of blood. The existence of specific clusters of cells with stemness-like characteristics like differentiation, self-renewal, detoxification, and resistance to apoptosis in Leukemia makes them difficult to treat. It was recently reported that an oncofetal RNA binding protein, insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1), maintains leukemic stem cell properties. BTYNB is an inhibitor of IGF2BP1 that was shown to affect the biological functions of IGF2BP1 however, the effect of BTYNB in Leukemia is not properly established. In this study, we assessed the effect of BTYNB on leukemic cell differentiation and proliferation. We performed cell viability assay to assess the effect of BTYNB in leukemic cells. We then assessed cell morphology of the leukemic cells treated with BTYNB. Further, we conducted an apoptosis assay and cell cycle assay. We found the cell viability of leukemic cells was significantly decreased post treatment with BTYNBs. Further, a noticeable morphological change was observed in BTYNB treated leukemic cells. BTYNB treated leukemic cells showed increased cell death and cell cycle arrest at S-phase. Evidence from the upregulation of BAK and p21 further confirmed apoptosis and cycle arrest. The gene expression of differentiation genes such as CD11B, ZFPM1, and KLF5 were significantly upregulated in BTYNB treated leukemic cells, therefore, confirming cell differentiation. Collectively, our study showed inhibition of IGF2BP1 function using BTYNB promotes differentiation in leukemic cells.

Early and accurate detection of melanoma skin cancer using hybrid level set approach.

Digital dermoscopy is used to identify cancer in skin lesions, and sun exposure is one of the leading causes of melanoma. It is crucial to distinguish between healthy skin and malignant lesions when using computerised lesion detection and classification. Lesion segmentation influences categorization accuracy and precision. This study introduces a novel way of classifying lesions. Hair filters, gel, bubbles, and specular reflection are all options. An improved levelling method is employed in an innovative method for detecting and removing cancerous hairs. The lesion is distinguished from the surrounding skin by the adaptive sigmoidal function; this function considers the severity of localised lesions. An improved technique for identifying a lesion from surrounding tissue is proposed in the article, followed by a classifier and available features that resulted in 94.40% accuracy and 93% success. According to research, the best method for selecting features and classifications can produce more accurate predictions before and during treatment. When the recommended strategy is put to the test using the Melanoma Skin Cancer Dataset, the recommended technique outperforms the alternative.

Pan-cancer analysis of tissue and single-cell HIF-pathway activation using a conserved gene signature.

Activation of cellular hypoxia pathways, orchestrated by HIF (hypoxia-inducible factor) transcription factors, is a common feature of multiple tumor types, resulting from microenvironment factors and oncogenic mutation. Although they help drive many of the "hallmarks" of cancer and are associated with poor outcome and resistance to therapy, the transcriptional targets of HIF vary considerably depending on the cell type. By integrating 72 genome-wide assays of HIF binding and transcriptional regulation from multiple cancer types, we define a consensus set of 48 HIF target genes that is highly conserved across cancer types and cell lineages. These genes provide an effective marker of HIF activation in bulk and single-cell transcriptomic analyses across a wide range of cancer types and in malignant and stromal cell types. This allows the tissue-orchestrated responses to the hypoxic tumor microenvironment and to oncogenic HIF activation to be deconvoluted at the tumor and single-cell level.

Complete chloroplast genomes of two mint species (Lamiaceae) from Al-Madinah, Saudi Arabia: phylogenetic and genomic comparative analyses.

The genus Mentha encompasses mint species cultivated for their essential oils, which are formulated into a vast array of consumer products. However, the systematics of the genus Mentha is very complicated and still uncertain. This is largely because of the presence of frequent interspecific hybridization, variation in chromosome number, cytomixis, polymorphism in morphology and essential oil composition under different environmental conditions, colonial mutant propagation, as well as the occurrence of polyploidy, aneuploidy, and nothomorphs. Here, we present the plastome assemblies for a wilt-resistant Saudi Arabian accession of Mentha longifolia (L.) Huds and an alien hybrid Mentha × verticillata L. which are 152,078 bp and 152,026 bp in length, respectively, and exhibited large single-copy (LSC) and small single-copy (SSC) regions separated by a pair of inverted repeat regions. The chloroplast genome of M. longifolia has 133 annotated genes, including 88 protein-coding genes and 37 tRNAs while M. × verticillata has 133 annotated genes, including 87 protein-coding genes and 38 tRNAs. Both cp genomes have eight rRNA genes. Phylogenetic analysis using a total chloroplast genome DNA sequence of 17 species revealed that M. longifolia sequenced in this study did not form a sister relationship with M. longifolia from another study. This opens a window for further investigations.

NAT10: An RNA cytidine transferase regulates fatty acid metabolism in cancer cells.

BACKGROUND: N-4 cytidine acetylation (ac4C) is an epitranscriptomics modification catalyzed by N-acetyltransferase 10 (NAT10); important for cellular mRNA stability, rRNA biogenesis, cell proliferation and epithelial to mesenchymal transition (EMT). However, whether other crucial pathways are regulated by NAT10-dependent ac4C modification in cancer cells remains unclear. Therefore, in this study, we explored the impact of NAT10 depletion in cancer cells using unbiased RNA-seq. METHODS: High-throughput sequencing of knockdown NAT10 in cancer cells was conducted to identify enriched pathways. Acetylated RNA immunoprecipitation-seq (acRIP-seq) and RIP-PCR were used to map and determine ac4C levels of RNA. Exogenous palmitate uptake assay was conducted to assess NAT10 knockdown cancer cells using Oil Red O staining and lipid content analysis. Gas-chromatography-tandem mass spectroscopy (GC/MS) was used to perform untargeted lipidomics. RESULTS: High-throughput sequencing of NAT10 knockdown in cancer cells revealed fatty acid (FA) metabolism as the top enriched pathway through the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis in differentially downregulated genes. FA metabolic genes such as ELOLV6, ACSL1, ACSL3, ACSL4, ACADSB and ACAT1 were shown to be stabilised via NAT10-dependent ac4C RNA acetylation. Additionally, NAT10 depletion was shown to significantly reduce the levels of overall lipid content, triglycerides and total cholesterol. Further, NAT10 depletion in palmitate-loaded cancer cells showed decrease in ac4C levels across the RNA transcripts of FA metabolic genes. In untargeted lipidomics, 496 out of 2 279 lipids were statistically significant in NAT10 depleted cancer cells, of which pathways associated with FA metabolism are the most enriched. CONCLUSIONS: Conclusively, our results provide novel insights into the impact of NAT10-mediated ac4C modification as a crucial regulatory factor during FA metabolism and showed the benefit of targeting NAT10 for cancer treatment.

Structural-Guided Identification of Small Molecule Inhibitor of UHRF1 Methyltransferase Activity.

Ubiquitin-like containing plant homeodomain Ring Finger 1 (UHRF1) protein is recognized as a cell-cycle-regulated multidomain protein. UHRF1 importantly manifests the maintenance of DNA methylation mediated by the interaction between its SRA (SET and RING associated) domain and DNA methyltransferase-1 (DNMT1)-like epigenetic modulators. However, overexpression of UHRF1 epigenetically responds to the aberrant global methylation and promotes tumorigenesis. To date, no potential molecular inhibitor has been studied against the SRA domain. Therefore, this study focused on identifying the active natural drug-like candidates against the SRA domain. A comprehensive set of in silico approaches including molecular docking, molecular dynamics (MD) simulation, and toxicity analysis was performed to identify potential candidates. A dataset of 709 natural compounds was screened through molecular docking where chicoric acid and nystose have been found showing higher binding affinities to the SRA domain. The MD simulations also showed the protein ligand interaction stability of and in silico toxicity analysis has also showed chicoric acid as a safe and nontoxic drug. In addition, chicoric acid possessed a longer interaction time and higher LD50 of 5000 mg/kg. Moreover, the global methylation level (%5 mC) has been assessed after chicoric acid treatment was in the colorectal cancer cell line (HCT116) at different doses. The result showed that 7.5 µM chicoric acid treatment reduced methylation levels significantly. Thus, the study found chicoric acid can become a possible epidrug-like inhibitor against the SRA domain of UHRF1 protein.

Systematic Development of Solid Lipid Nanoparticles of Abiraterone Acetate with Improved Oral Bioavailability and Anticancer Activity for Prostate Carcinoma Treatment.

In the present work, an attempt was undertaken to improve the oral bioavailability and anticancer activity of abiraterone acetate. Solid lipid nanoparticles (SLNs) were developed using the quality by design (QbD) principles and evaluated through in vitro, ex vivo, and in vivo studies. Solid lipid suitability was evaluated by equilibrium solubility study, while surfactant and cosurfactant were screened based on the ability to form microemulsion with the selected lipid. SLNs were prepared by emulsion/solvent evaporation method using glyceryl monostearate, Tween 80, and Poloxamer 407 as the solid lipid, surfactant, and cosurfactant, respectively. Box-Behnken design was applied for optimization of material attributes and evaluating their impact on particle size, polydispersity index, zeta potential, and entrapment efficiency of the SLNs. In vitro drug release study was evaluated in simulated gastric and intestinal fluids. Cell culture studies on PC-3 cells were performed to evaluate the cytotoxicity of the drug-loaded SLNs in comparison to the free drug suspension. Qualitative uptake was evaluated for Rhodamine B-loaded SLNs and compared with free dye solution. Ex vivo permeability was evaluated on Wistar rat intestine and in vivo pharmacokinetic evaluation on Wistar rats for SLNs and free drug suspension. Concisely, the SLNs showed potential for significant improvement in the biopharmaceutical performance of the selected drug candidate over the existing formulations of abiraterone acetate.

Exosome-Mediated Response to Cancer Therapy: Modulation of Epigenetic Machinery.

Exosomes, the extracellular vesicles produced in the endosomal compartments, facilitate the transportation of proteins as well as nucleic acids. Epigenetic modifications are now considered important for fine-tuning the response of cancer cells to various therapies, and the acquired resistance against targeted therapies often involves dysregulated epigenetic modifications. Depending on the constitution of their cargo, exosomes can affect several epigenetic events, thus impacting post-transcriptional regulations. Thus, a role of exosomes as facilitators of epigenetic modifications has come under increased scrutiny in recent years. Exosomes can deliver methyltransferases to recipient cells and, more importantly, non-coding RNAs, particularly microRNAs (miRNAs), represent an important exosome cargo that can affect the expression of several oncogenes and tumor suppressors, with a resulting impact on cancer therapy resistance. Exosomes often harbor other non-coding RNAs, such as long non-coding RNAs and circular RNAs that support resistance. The exosome-mediated transfer of all this cargo between cancer cells and their surrounding cells, especially tumor-associated macrophages and cancer-associated fibroblasts, has a profound effect on the sensitivity of cancer cells to several chemotherapeutics. This review focuses on the exosome-induced modulation of epigenetic events with resulting impact on sensitivity of cancer cells to various therapies, such as, tamoxifen, cisplatin, gemcitabine and tyrosine kinase inhibitors. A better understanding of the mechanisms by which exosomes can modulate response to therapy in cancer cells is critical for the development of novel therapeutic strategies to target cancer drug resistance.

Profiling the Effect of Targeting Wild Isocitrate Dehydrogenase 1 (IDH1) on the Cellular Metabolome of Leukemic Cells.

Leukemia is one of the most common primary malignancies of the hematologic system in both children and adults and remains a largely incurable or relapsing disease. The elucidation of disease subtypes based on mutational profiling has not improved clinical outcomes. IDH1/2 are critical enzymes of the TCA cycle that produces α-ketoglutarate (αKG). However, their mutated version is well reported in various cancer types, including leukemia, which produces D-2 hydroxyglutarate (D-2HG), an oncometabolite. Recently, some studies have shown that wild-type IDH1 is highly expressed in non-small cell lung carcinoma (NSCLC), primary glioblastomas (GBM), and several hematological malignancies and is correlated with disease progression. This work shows that the treatment of wild-type IDH1 leukemia cells with a specific IDH1 inhibitor shifted leukemic cells toward glycolysis from the oxidative phosphorylation (OXPHOS) phenotype. We also noticed a reduction in αKG in treated cells, possibly suggesting the inhibition of IDH1 enzymatic activity. Furthermore, we found that IDH1 inhibition reduced the metabolites related to one-carbon metabolism, which is essential for maintaining global methylation in leukemic cells. Finally, we observed that metabolic alteration in IDH1 inhibitor-treated leukemic cells promoted reactive oxygen species (ROS) formation and the loss of mitochondrial membrane potential, leading to apoptosis in leukemic cells. We showed that targeting wild-type IDH1 leukemic cells promotes metabolic alterations that can be exploited for combination therapies for a better outcome.

Exosomal miRNAs as a Promising Source of Biomarkers in Colorectal Cancer Progression.

Colorectal cancer (CRC) is the third most common type of cancer worldwide amongst males and females. CRC treatment is multidisciplinary, often including surgery, chemotherapy, and radiotherapy. Early diagnosis of CRC can lead to treatment initiation at an earlier stage. Blood biomarkers are currently used to detect CRC, but because of their low sensitivity and specificity, they are considered inadequate diagnostic tools and are used mainly for following up patients for recurrence. It is necessary to detect novel, noninvasive, specific, and sensitive biomarkers for the screening and diagnosis of CRC at earlier stages. The tumor microenvironment (TME) has an essential role in tumorigenesis; for example, extracellular vesicles (EVs) such as exosomes can play a crucial role in communication between cancer cells and different components of TME, thereby inducing tumor progression. The importance of miRNAs that are sorted into exosomes has recently attracted scientists' attention. Some unique sequences of miRNAs are favorably packaged into exosomes, and it has been illustrated that particular miRNAs can be directed into exosomes by special mechanisms that occur inside the cells. This review illustrates and discusses the sorted and transported exosomal miRNAs in the CRC microenvironment and their impact on CRC progression as well as their potential use as biomarkers.

Hispolon-Loaded Liquid Crystalline Nanoparticles: Development, Stability, In Vitro Delivery Profile, and Assessment of Hepatoprotective Activity in Hepatocellular Carcinoma.

The present work describes the development and characterization of liquid crystalline nanoparticles of hispolon (HP-LCNPs) for treating hepatocellular carcinoma. HP-LCNPs were prepared by a top-down method utilizing GMO as the lipid and Pluronic F-127 as the polymeric stabilizer. The prepared formulations (HP1-HP8) were tested for long-term stability, where HP5 showed good stability with a particle size of 172.5 ± 0.3 nm, a polydispersity index (PDI) of 0.38 ± 0.31 nm, a zeta potential of -10.12 mV ± 0.05, an entrapment efficiency of 86.81 ± 2.5%, and a drug loading capacity of 12.51 ± 1.12%. Optical photomicrography and transmission electron microscopy images demonstrated a consistent, low degree of aggregation and a spherical shape of LCNPs. The effect of temperature and pH on the optimized formulation (HP5) indicated good stability at 45 °C and at pH between 2 and 5. In vitro gastrointestinal stability indicated no significant change in the particle size, PDI, and entrapment efficiency of the drug. The drug release study exhibited a biphasic pattern in simulated gastric fluid (pH 1.2) for 2 h and simulated intestinal fluid (pH 7.4) for up to 24 h, while the best fitting of the profile was observed with the Higuchi model, indicating the Fickian diffusion mechanism. The in vivo pharmacokinetic study demonstrated nearly 4.8-fold higher bioavailability from HP5 (AUC: 1774.3 ± 0.41 µg* h/mL) than from the HP suspension (AUC: 369.11 ± 0.11 µg* h/mL). The anticancer activity evaluation revealed a significant improvement in antioxidant parameters and serum hepatic biomarkers (SGOT, SGPT, ALP, total bilirubin, and GGT) in the diethyl nitrosamine-treated group of rats with the optimized LCNP formulation (HP5) vis-à-vis HP suspension.

Untargeted Metabolomics Showed Accumulation of One-Carbon Metabolites to Facilitate DNA Methylation during Extracellular Matrix Detachment of Cancer Cells.

Tumor cells detached from the extracellular matrix (ECM) undergo anoikis resistance and metabolic reprogramming to facilitate cancer cell survival and promote metastasis. During ECM detachment, cancer cells utilize genomic methylation to regulate transcriptional events. One-carbon (1C) metabolism is a well-known contributor of SAM, a global substrate for methylation reactions, especially DNA methylation. DNA methylation-mediated repression of NK cell ligands MICA and MICB during ECM detachment has been overlooked. In the current work, we quantitated the impact of ECM detachment on one-carbon metabolites, expression of 1C regulatory pathway genes, and total methylation levels. Our results showed that ECM detachment promotes the accumulation of one-carbon metabolites and induces regulatory pathway genes and total DNA methylation. Furthermore, we measured the expression of well-known targets of DNA methylation in NK cell ligands in cancer cells, namely, MICA/B, during ECM detachment and observed low expression compared to ECM-attached cancer cells. Finally, we treated the ECM-detached cancer cells with vitamin C (a global methylation inhibitor) and observed a reduction in the promoter methylation of NK cell ligands, resulting in MICA/B re-expression. Treatment with vitamin C was also found to reduce global DNA methylation levels in ECM-detached cancer cells.

Venetoclax-Resistant MV4-11 Leukemic Cells Activate PI3K/AKT Pathway for Metabolic Reprogramming and Redox Adaptation for Survival.

Venetoclax (ABT199) is a selective B-cell lymphoma 2 (BCL-2) inhibitor. The US FDA recently approved it to be used in combination with low-dose cytarabine or hypomethylating agents in acute myeloid leukemia (AML) or elderly patients non-eligible for chemotherapy. However, acquiring resistance to venetoclax in AML patients is the primary cause of treatment failure. To understand the molecular mechanisms inherent in the resistance to BCL-2 inhibitors, we generated a venetoclax-resistant cell line model and assessed the consequences of this resistance on its metabolic pathways. Untargeted metabolomics data displayed a notable impact of resistance on the PI3K/AKT pathway, the Warburg effect, glycolysis, the TCA cycle, and redox metabolism. The resistant cells showed increased NADPH and reduced glutathione levels, switching their energy metabolism towards glycolysis. PI3K/AKT pathway inhibition shifted resistant cells towards oxidative phosphorylation (OXPHOS). Our results provide a metabolic map of resistant cells that can be used to design novel metabolic targets to challenge venetoclax resistance in AML.

The Histone H3K27me3 Demethylases KDM6A/B Resist Anoikis and Transcriptionally Regulate Stemness-Related Genes.

Epithelial cancer cells that lose attachment from the extracellular matrix (ECM) to seed in a distant organ often undergo anoikis's specialized form of apoptosis. Recently, KDM3A (H3K9 demethylase) has been identified as a critical effector of anoikis in cancer cells. However, whether other histone demethylases are involved in promoting or resisting anoikis remains elusive. We screened the major histone demethylases and found that both H3K27 histone demethylases, namely, KDM6A/B were highly expressed during ECM detachment. Inhibition of the KDM6A/B activity by using a specific inhibitor results in reduced sphere formation capacity and increased apoptosis. Knockout of KDM6B leads to the loss of stem cell properties in solitary cells. Furthermore, we found that KDM6B maintains stemness by transcriptionally regulating the expression of stemness genes SOX2, SOX9, and CD44 in detached cells. KDM6B occupies the promoter region of both SOX2 and CD44 to regulate their expression epigenetically. We also noticed an increased occupancy of the HIF1α promoter by KDM6B, suggesting its regulatory role in maintaining hypoxia in detached cancer cells. This observation was further strengthened as we found a significant positive association in the expression of both KDM6B and HIF1α in various cancer types. Overall, our results reveal a novel transcriptional program that regulates resistance against anoikis and maintains stemness-like properties.

Structure-Activity Studies Reveal Scope for Optimisation of Ebselen-Type Inhibition of SARS-CoV-2 Main Protease.

The reactive organoselenium compound ebselen is being investigated for treatment of coronavirus disease 2019 (COVID-19) and other diseases. We report structure-activity studies on sulfur analogues of ebselen with the Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) main protease (Mpro ), employing turnover and protein-observed mass spectrometry-based assays. The results reveal scope for optimisation of ebselen/ebselen derivative- mediated inhibition of Mpro , particularly with respect to improved selectivity.

High-throughput screening to identify potential inhibitors of the Zα domain of the adenosine deaminase 1 (ADAR1).

Adenosine deaminases acting on RNA 1 (ADAR1) are enzymes involved in editing adenosine to inosine in the dsRNAs of cells associated with cancer development. The p150 isoform of ADAR1 is the only isoform containing the Zα domain that binds to both Z-DNA and Z-RNA. The Zα domain is suggested to modulate the immune response and could be a suitable target for antiviral treatment and cancer immunotherapy. In this study, we aimed to identify potential inhibitors for ADAR1 protein that bind the Zα domain using molecular docking and simulation tools. Virtual docking and molecular dynamics simulation approaches were used to screen the potential activity of 2115 FDA-approved compounds on the Zα domain of ADAR1 and filtered for to obtain the top-scoring hits. The top three compounds with the best XP Gscore-namely alendronate (-7.045), etidronate (-6.923), and zoledronate (-6.77)-were subjected to 50 ns simulations to characterize complex stability and identify the fundamental interactions that contribute to inhibition of the ADAR1 Zα domain. The three compounds were shown to interact with Lys169, Lys170, Asn173, and Tyr177 of the Zα domain-like helical backbone of Z-RNA. The study provides a comprehensive and novel insights of repurposes drugs for the inhibition of ADAR1 function.

Comparative Analysis of the Impact of Urolithins on the Composition of the Gut Microbiota in Normal-Diet Fed Rats.

The gut microbiota consists of a community of microorganisms that inhabit the large intestine. These microbes play important roles in maintaining gut barrier integrity, inflammation, lipid and carbohydrate metabolism, immunity, and protection against pathogens. However, recent studies have shown that dysfunction in the gut microbiota composition can lead to the development of several diseases. Urolithin A has recently been approved as a functional food ingredient. In this study, we examined the potentials of urolithin A (Uro-A) and B (Uro-B) in improving metabolic functions and their impact on gut microbiota composition under a metabolically unchallenged state in normal rats. Male Wistar rats (n = 18) were randomly segregated into three groups, with Group 1 serving as the control group. Groups 2 and 3 were administered with 2.5 mg/kg Uro-A and Uro-B, respectively, for four weeks. Our results showed that both Uro-A and B improved liver and kidney functions without affecting body weight. Metagenomic analysis revealed that both Uro-A and B induced the growth of Akkermansia. However, Uro-A decreased species diversity and microbial richness and negatively impacted the composition of pathogenic microbes in normal rats. Taken together, this study showed the differential impacts of Uro-A and B on the gut microbiota composition in normal rats and would thus serve as a guide in the choice of these metabolites as a functional food ingredient or prebiotic.