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Results for “molecular dynamic simulation assay”

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At least 19 recordsLinked to original sources

PubMed2026

Activity of natural single nucleotide variants of human alkyladenine DNA glycosylase AAG R145H, G163S and R197C involved in DNA binding.

Alkyladenine DNA glycosylase (AAG) is a critical enzyme in the base excision repair (BER) pathway that safeguards genome integrity by removing structurally diverse alkylated and deaminated purine lesions from DNA. It serves as a primary defense against alkylation-induced mutations, which are linked to cancer development, chronic inflammation, and neurodegenerative diseases. Single nucleotide variants (SNVs) in the gene coding region have the potential to alter the enzyme's functionality, potentially modulating the repair capacity and affecting response and prognosis following chemoradiotherapy. In our study, we investigated three SNVs that lead to amino acid class changes in regions involved in DNA substrate coordination: R145H, G163S, and R197C using an in vitro approach. Using biochemical assays and molecular dynamics simulations, we evaluated the thermal stability, DNA binding affinity, and glycosylase activity of AAG variants toward hypoxanthine (Hx) and 1,N6-ethenoadenosine (εA) containing substrates. The G163S variant showed reduced thermal stability due to the conformational strain in the β-hairpin loop that intercalates in DNA, but retained εA excision activity comparable to that of wild-type AAG, while losing activity against Hx-containing DNA. The R197C variant had a four-fold reduction in DNA binding affinity for both substrates, and was catalytically inactive, unable to excise either damaged bases. This loss of function correlated with the rearrangement of the 201-210 loop and the reorientation of Arg-201 and Arg-207, which disrupts critical DNA contacts. However, the R145H variant retained near-wild-type thermal stability and activity on both substrates, despite bioinformatic predictions of deleterious effect. Molecular dynamics simulations revealed variant-specific structural disruptions. The data obtained underscore the importance of experimental validation in assessing the functional impact SNVs.

DNA Glycosylases↗

PubMed2023

Structural and functional insights into a novel homozygous missense pathogenic variant in CUL7 identified in consanguineous Pakistani family.

3M syndrome is a rare genetic familial disorder characterized by short stature, growth retardation, facial dysmorphism, skeletal abnormalities, fleshy protruding heels, and normal intelligence, caused by mutations in the CUL7, OBSL1 and CCDC8 genes. In the present study, a novel homozygous missense variant of CUL7 (NP_001161842.1, c.4493T > C, p.L1498P) has been identified in a consanguineous Pakistani family by whole exome sequencing. In silico structural evaluation, molecular docking and simulation studies of mutant CUL7 provides substantial evidence about its crucial role in the progression of discussed ailment. The newly discovered variant significantly altered the protein's three dimensional structure, leading to abnormal interaction with binding proteins. This computational and experimental investigation provides useful information to drug developers for the synthesis of novel therapeutics against the discussed ailment.Communicated by Ramaswamy H. Sarma.

Humans↗

PubMed2026

Targeting EGFR in cancer using Terminalia arjuna: An integrated In Silico, molecular dynamics, experimental validation, and network pharmacology study.

The Epidermal Growth Factor Receptor (EGFR) plays a pivotal role in 20-60% of cancer cases, including glioblastoma, lung adenocarcinoma, and head and neck squamous cell carcinoma, as reported in The Cancer Genome Atlas (TCGA) dataset. The present study employed an integrated in silico and experimental workflow to evaluate EGFR-targeted compounds from Terminalia arjuna. Drug-likeness and ADMET screening were performed, followed by molecular docking and 1000 ns molecular dynamics simulations. In vitro validation was conducted using cancer cell-based assays and network pharmacology to explore the molecular mechanisms associated with the identified compound. Screening shortlisted eight compounds from T. arjuna. Molecular docking identified Arjunaside C (-8.2 kcal/mol), Arjunapthanoloside (-7.7 kcal/mol), and Beta-sitosterol (-7.4 kcal/mol) as potential EGFR inhibitors compared to Erlotinib (-6.6 kcal/mol). Arjunapthanoloside formed more H-bonds and exhibited most stable interactions with EGFR. MD simulations at 1000 ns revealed lower RMSD, RMSF, SASA, and Rg values for the Arjunapthanoloside-EGFR complex, indicating enhanced stability. Direct binding validation was limited by the unavailability of purified Arjunapthanoloside; therefore, Arjuna extract was evaluated, which demonstrated potent cytotoxicity with an IC₅₀ of 9 µg/mL in H357 oral cancer cells. Flow cytometry confirmed apoptosis-mediated cell death by increased early- and late-apoptotic cell populations. Network pharmacology analysis further identified additional targets (MMP3, MMP7, MMP9, and HRAS) that are directly involved in various cancers. Overall, the findings provide new insights into the therapeutic potential of Arjunapthanoloside as a stable compound that interacts with EGFR from T. arjuna, highlighting its significance in EGFR-targeted anticancer research.

ErbB Receptors↗

PubMed2025

Structural and thermodynamic impact of oncogenic mutations on the nucleosome core particle.

The nucleosome core particle is essential for chromatin structure and function, serving as the fundamental unit of eukaryotic chromatin. Oncogenic mutations in core histones disrupt chromatin dynamics, altering DNA repair and transcription processes. Here, we investigate the molecular consequences of two mutations-H2BE76K and H4R92T-using 36 μs of all-atom molecular dynamics simulations and experimental biophysical assays. These mutations destabilize the H2B-H4 interface by disrupting critical salt bridges and hydrogen bonds, reducing binding free energy at this interface. Principal-component analysis reveals altered helix conformations and increased interhelical distances in mutant systems. Thermal stability assays and differential scanning calorimetry confirm that these mutations lower the dimer dissociation temperature and reduce enthalpy compared with the wild-type. Taken together, our results elucidate how these mutations compromise nucleosome stability and propose mechanisms through which they could modulate chromatin accessibility and gene dysregulation in cancer.

Nucleosomes↗

PubMed2026

Inhibitory mechanism of phloretin on the AgrA LytTR domain-agr operon complex formation and its application in beef.

Staphylococcus aureus (S. aureus) represents a major foodborne pathogen whose enterotoxin production poses significant challenges to food safety due to its high environmental resistance and limited efficacy of conventional sterilization. Since the expression of enterotoxins is predominantly governed by the agr quorum sensing system, targeting this regulatory pathway has become a strategic choice for virulence control. This study elucidated the mechanism by which phloretin, a potential quorum sensing inhibitor, interferes with the agr system to attenuate virulence. To achieve this, the recombinant AgrA LytTR domain was expressed and purified, and its interaction with phloretin was characterized using thermal shift assays (TSA), electrophoretic mobility shift assays (EMSA), and molecular dynamics (MD) simulations. The results showed that phloretin specifically binds to the AgrA LytTR domain, enhancing its thermal stability and disrupting AgrA LytTR-agr operon binding by reducing the free energy of interaction between them, without causing significant structural rearrangement. Mechanistic analysis indicated that phloretin sterically hinders key β-sheet turn residues (HIS169, ASN201, ARG233), thereby impairing DNA recognition, downregulating RNAIII transcription, and inhibiting agr signaling. In cooked beef, phloretin significantly inhibited the secretion of enterotoxins and α-hemolysin, while delaying lipid oxidation and protein degradation, and maintaining the meat texture. These findings suggested that phloretin is a multifunctional substance with anti-virulence, antioxidant, and preservative properties, demonstrating its potential as a natural food preservative.

Phloretin↗

PubMed2026

Matrine Alleviates Sepsis-Induced Acute Lung Injury by Reinforcing NQO1/SLC7A11/GPX4-Associated Anti-Ferroptotic Defenses and Attenuating NF-κB-Driven Inflammation.

BACKGROUND: Sepsis triggers dysregulated systemic inflammation and multiple-organ dysfunction, with the lungs being particularly susceptible to injury. Sepsis-induced acute respiratory distress syndrome (ARDS) is mainly driven by TLR4/NF-κB-mediated hyperinflammation and alveolar macrophage activation. Matrine, a bioactive alkaloid derived from Sophora flavescens, has been reported to modulate redox homeostasis and ferroptosis-associated lipid peroxidation. However, the target-specific mechanisms underlying its effects on ferroptosis and inflammatory signaling in sepsis-induced acute lung injury (SALI) remain incompletely understood. PURPOSE: This study aimed to evaluate the therapeutic effects of matrine in a cecal ligation and puncture (CLP)-induced SALI model and to determine whether its protective effects involve reinforcement of NQO1/SLC7A11/GPX4-associated anti-ferroptotic defenses and suppression of NF-κB-driven inflammation. METHODS: We analyzed the single-cell RNA-sequencing (scRNA-seq) dataset GSE273924 to characterize CD45-enriched pulmonary immune-cell subsets in sham mice and mice with intratracheal Escherichia coli-induced pneumonia. Network pharmacology and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed to predict Kushen (KS)-related targets and pathways associated with SALI. Differential expression analysis and weighted gene co-expression network analysis (WGCNA) of GSE245013 were used to identify candidate targets. Matrine-NQO1 binding and intracellular target engagement were evaluated using molecular docking, molecular dynamics simulations, surface plasmon resonance (SPR), and the cellular thermal shift assay (CETSA). The therapeutic effects of matrine were assessed in mice with CLP-induced SALI and in lipopolysaccharide (LPS)-stimulated MH-S cells. Lung histopathology, inflammatory cytokine production, target protein expression, ferroptosis-associated indicators, and NF-κB activation were evaluated using molecular, biochemical, and histological assays. The functional contribution of NQO1 was further examined using the NQO1 inhibitor ES936. RESULTS: scRNA-seq analysis of GSE273924 revealed substantial remodeling of the CD45-enriched pulmonary immune-cell landscape in mice with intratracheal E. coli-induced pneumonia, including macrophage transcriptional programs associated with ferroptosis and inflammatory signaling. Integrated network pharmacology and bioinformatics analyses prioritized NQO1 as a candidate target of matrine and identified NF-κB signaling as a potentially relevant pathway. Molecular docking, molecular dynamics simulations, SPR, and CETSA supported matrine-NQO1 binding and intracellular target engagement. Functionally, matrine improved survival, attenuated lung injury, reinforced NQO1/SLC7A11/GPX4-associated anti-ferroptotic defenses, and suppressed NF-κB activation in CLP mice. Similar protective effects were observed in LPS-stimulated MH-S cells. ES936 partially attenuated the matrine-mediated improvements in cell viability, redox homeostasis, ferroptosis-associated indicators, and NF-κB p65 phosphorylation, supporting a functional contribution of NQO1 to the protective effects of matrine. CONCLUSION: Matrine alleviates SALI by reinforcing NQO1/SLC7A11/GPX4-associated anti-ferroptotic defenses and attenuating NF-κB-driven inflammation.

Animals↗

PubMed2026

Integrated dual transcriptome sequencing and experimental validation reveal potential mechanisms of baicalin against pneumocystis pneumonia in immunosuppressed rats.

BACKGROUND: Pneumocystis pneumonia (PCP) remains a major cause of morbidity and mortality in immunocompromised individuals. Although baicalin (Ba), a natural bioactive flavonoid, has demonstrated protective and therapeutic effects against PCP, its molecular mechanisms remain undefined. We employed dual RNA sequencing (dual RNA-seq) to characterize host and pathogen transcriptional responses to Ba treatment in an immunosuppressed rat model of PCP. METHODS: Comparative transcriptomic analyses identified differentially expressed genes in both the host and Pneumocystis, followed by Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and gene set enrichment analyses. Candidate targets were further investigated using network pharmacology, protein-protein interaction analysis, molecular docking, and molecular dynamics simulations. Key findings were validated by immunohistochemistry, enzyme-linked immunosorbent assay, and quantitative PCR. RESULTS: Ba markedly remodeled host and pathogen transcriptomes. Host transcriptomic analyses showed that Ba attenuated inflammatory and oxidative stress responses by modulating immune-related pathways, including Toll-like receptor, NF-κB, cytokine-cytokine receptor interaction, chemokine signaling, Th17 cell differentiation, and antigen processing and presentation. Experimental validation demonstrated that Ba reduced pulmonary expression of indoleamine 2,3-dioxygenase 1 (IDO1), Toll-like receptor 2 (TLR2), and TLR4 while increasing nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream antioxidant enzyme heme oxygenase-1 (HO-1). Pathogen transcriptomic analysis identified Pneumocystis Rtt109 (PcRtt109), a fungal histone acetyltransferase, as a potential pathogen-specific target that was significantly downregulated after Ba treatment. Molecular docking and molecular dynamics simulations supported stable interactions between Ba and IDO1, Nrf2, TLR2, TLR4, and PcRtt109, with the strongest predicted binding observed for PcRtt109. CONCLUSION: Dual RNA-seq revealed that Ba exerts anti-PCP activity through coordinated modulation of host and pathogen molecular networks. Its therapeutic effects are associated with suppression of inflammatory signaling, enhancement of antioxidant defenses, and inhibition of a fungal virulence-associated target. These findings provide mechanistic insights into host-pathogen interactions during PCP and support Ba as a potential therapeutic candidate for PCP.

Nrf2↗

PubMed2026

Investigating the mechanisms of PhIP-induced colorectal cancer through network toxicology, machine learning, and molecular dynamics simulation.

BACKGROUND: Over the past few years, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)- a compound from grilled or processed meats-has emerged as a major player in cancer development, especially colorectal cancer (CRC). This work dives into its potential links to CRC and uncovers the key genes that bridge this connection. METHODS: We tapped into various databases to pinpoint target genes tied to PhIP and CRC, then ran protein-protein interaction (PPI) analyses for visualization. Next, we explored underlying mechanisms through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment. To nail down predictions, we tested 107 machine learning pipelines and picked the best one, validating its accuracy and the core genes' prognostic value across datasets. Next, molecular docking and dynamics simulations probed the interactions between these genes and PhIP. Finally, cell proliferation was assessed using Cell Counting Kit-8 (CCK-8) and 5-ethynyl-2'-deoxyuridine (EdU) assays, and polymerase chain reaction (PCR) was performed to validate the expression levels of the hub genes. RESULTS: Our analysis identified 39 overlapping genes, from which a machine learning model (glmBoost + Enet) identified six candidate targets: CDK4, CEBPB, COMT, SOX9, TIMP1, and TOP2A. To prioritize these, a hierarchical screening framework was applied. Molecular docking and dynamics simulations identified CDK4, COMT, and TIMP1 as the most stable interactors with PhIP. Functional assays confirmed that PhIP treatment significantly enhanced the proliferation of CRC cells. Crucially, quantitative PCR (qPCR) validation in multiple CRC cell lines identified TIMP1 as the primary target, showing the most consistent and significant upregulation upon PhIP exposure. CONCLUSIONS: In essence, these genes drive PhIP is role in CRC, offering novel insights into its molecular pathways. This could reshape how we tackle food-related pollutants, paving the way for better prevention and targeted therapies.

Colorectal cancer (CRC)↗

PubMed2026

Integrated computational and experimental benchmarking of Bacillus phage endolysins reveals the relationship between peptidoglycan-fragment recognition descriptors and antibacterial performance.

Protein-based antibacterials such as bacteriophage endolysins offer a targeted therapeutic strategy against Gram-positive pathogens. However, prioritizing the most effective candidates from the large sequence diversity available remains a significant challenge. Here we present a standardized computational-experimental benchmarking framework that evaluates seven phage-derived endolysin variants (E1, E2, E3, E7, E10, E12, and E15) identified from Bacillus genomes. We combined molecular docking and residue-level interaction mapping against muramyl dipeptide (MDP), a minimal conserved peptidoglycan motif, with 1000-ns molecular dynamics simulations, MM/PBSA binding free-energy estimation, and matched functional inhibition assays against Staphylococcus aureus and Micrococcus luteus. Computational analyses revealed generally favorable MDP recognition across variants, albeit with notable differences in contact patterns and complex stability profiles. Experimental screening identified E2 as the most potent antibacterial agent against both species, while E7 and E1 performed strongly in selected computational metrics. Integrated analysis showed only modest correlations between computational descriptors of fragment recognition/stability and observed antibacterial performance. This study establishes a practical comparative benchmarking platform for endolysin candidate prioritization, nominates E2 and E7 as promising candidates for further development, and highlights E1 as a potential structural scaffold for rational engineering, while explicitly demonstrating both the utility and the current limitations of using minimal peptidoglycan fragments as proxies for full cell-wall recognition in lysin benchmarking.

Endopeptidases↗

PubMed2026

Novel environmental contaminant 6PPD-quinone promotes malignant phenotypes in colorectal cancer cells and identifies candidate response-associated genes.

6PPD-quinone (6PPDQ), an oxidative transformation product of the widely used tire antioxidant 6PPD, is a ubiquitous environmental contaminant with bioaccumulation potential and widespread human exposure. Recent epidemiological evidence indicates a positive association between urinary 6PPDQ levels and colorectal cancer (CRC) risk; however, its biological effects on CRC-related phenotypes and associated molecular responses remain unclear. We integrated bioinformatics analysis, prognostic modeling, molecular docking and dynamics simulations, and in vitro experiments to investigate cellular and molecular responses to 6PPDQ in CRC models. Predicted 6PPDQ targets were intersected with CRC prognosis-related genes from The Cancer Genome Atlas, followed by functional enrichment and LASSO regression to construct a prognostic risk model, with 1-, 3-, and 5-year AUC values of 0.727, 0.754, and 0.778, respectively. Molecular docking and 100-ns molecular dynamics simulations suggested interactions between 6PPDQ and candidate proteins, including CPT2, SHC2, SRMS, and STK35. Functional assays showed that 6PPDQ exposure altered proliferation, wound-closure capacity, and invasion in Caco-2 and HCT116 cells across the nanomolar concentration range, with non-monotonic and cell-line-dependent responses. In contrast, NCM460 cells showed no increase in EdU incorporation at 10 or 100 nM, whereas reduced proliferation at higher concentrations was accompanied by increased LDH release. 6PPDQ also altered the expression of several prognosis-associated candidate genes. These findings identify cellular phenotypes and candidate molecular responses associated with 6PPDQ exposure under the tested in vitro conditions, but do not establish their causal roles or in vivo relevance. Further mechanistic and in vivo studies are required.

Humans↗

PubMed2026

Proteomic regulation of anti-proliferative and anti-migratory activity by potent phytochemicals from Pistacia integerrima J.L. Steward Ex Brandis via PI3K, AKT1, and KRAS for Lung Cancer.

BACKGROUND: Non-small cell lung cancer (NSCLC) is the leading cause of mortality worldwide and remains a major therapeutic challenge due to high metastasis, drug resistance and limited treatments. Pistacia integerrima J.L. Steward Ex Brandis (PI) consists of flavonoids, steroids, terpenoids and phenolic compounds reported for pharmacological activities. The efficacy of potent bioactives from P. integerrima may be ascertained employing cytotoxic, antiproliferative, anti-migratory, and anti-metastatic evaluations in A549 NSCLC cells with proteomic profiling, molecular docking, and dynamics simulation study. METHODS AND RESULTS: PI EtAc produced significant dose-dependent cytotoxicity in A549 cells (100 µg/mL, p < 0.0001 in the MTT assay. There was a pronounced decrease in colony formation after treatment with EtAc, with 18.41% (p < 0.002), and markedly. Furthermore. PI EtAC markedly inhibited cell migration emphasized by wound healing and Transwell migration (p < 0.01) assays, indicating reduced metastatic migratory potential. Proteomic analysis demonstrated significant downregulation of Endoglin (CD105), KLK5 and MMP-2, indicating suppression of angiogenic and metastatic signalling pathways in the Human XL Oncology protein array. The interaction of major PI phytochemicals with key NSCLC-associated targets was recorded in Molecular docking, revealing favourable binding affinities of kaempferol, β- sitosterol, luteolin, and quercetin towards several oncogenic targets, including AKT1(- 7.6 kcal/mol), PI3K(- 9.4 kcal/mol), KRAS (- 8.5 kcal/mol) and MMP9 (- 8.1 kcal/mol). Molecular dynamics simulation confirmed the structural stability of the kaempferol -AKT1 complex throughout the 100 ns simulation. CONCLUSION: Pistacia integerrima bioactives exhibited significant anti-proliferative, anti-migratory, and anti-metastatic activities in vitro, which may provide scientific rationale identifying newer promising candidates for NSCLC.

Humans↗

PubMed2026

Visual Detection and Stratification of Pathogenic mtDNA SNV Heteroplasmy by Balancing FnCas12a Signal Output and Allelic Discrimination.

Assessment of pathogenic mitochondrial DNA (mtDNA) single-nucleotide variant (SNV) heteroplasmy is important for molecular diagnostics, yet rapid visual profiling remains analytically challenging because an assay must combine single-nucleotide allelic discrimination, mutant-fraction-associated readout, and suitable target access. Herein, we report VISTA (visual identification and stratification of targeted mtDNA alleles), a broad-PAM FnCas12a assay that rebalances trans-cleavage signal output and mutant-wild-type discrimination for visual mtDNA SNV heteroplasmy analysis. VISTA uses unmodified FnCas12a with relaxed TTN PAM recognition and integrates crRNA spacer-length engineering with PEG8000/acBSA reaction tuning to improve the practical signal-discrimination balance without nuclease engineering. At the m.3243A>G model locus, spacer truncation enhanced mutant-wild-type discrimination, while molecular-dynamics simulations identified spacer-dependent differences between matched and mismatched complexes at the crRNA-DNA interface. The optimized assay resolved defined synthetic m.3243A>G heteroplasmy gradients by fluorescence imaging and was further adapted to lateral-flow detection. In locus-specific analyses of a deidentified collection of 74 peripheral-blood samples, fluorescence and lateral-flow readouts achieved ROC AUC values above 0.9 for mutant-allele classification after target-region amplification. Fluorescence supported heteroplasmy-associated profiling, whereas lateral flow provided a visual, semiquantitative readout for relative ranking based on the T/C ratio rather than absolute heteroplasmy measurement. VISTA therefore provides an accessible dual-readout analytical strategy for visual detection and heteroplasmy-associated profiling by tuning the FnCas12a signal output and allelic discrimination.

DNA, Mitochondrial↗

PubMed2026

Resveratrol Attenuates Gemcitabine Resistance in Hepatocellular Carcinoma Cells by Inhibiting Thymidylate Synthase.

BACKGROUND: Hepatocellular carcinoma (HCC) is a leading cause of cancer death worldwide. Gemcitabine (Gem) is a commonly used drug against HCC, but its efficacy is limited by the development of resistance. Resveratrol (Res), a natural polyphenol with antitumor activity, may reverse Gem resistance in HCC, although the mechanism remains unclear. METHODS: The effects of Res on the proliferation, apoptosis, cell cycle, and invasion of Hep3B and HuH-7 cells were assessed via cell counting kit-8 (CCK-8), clonogenic, flow cytometry, and Transwell assays, respectively. Potential Res targets were predicted by network pharmacology, and markers of HCC prognosis were identified from the cancer genome atlas (TCGA) data. The interaction between Res and thymidylate synthase (TYMS) was validated by molecular docking and dynamics simulation. A Gem-resistant HuH-7 cell line (HuH-7/GR) was established, and when these cells were treated with Res combined with Gem, the effect on Gem sensitivity was detected by CCK-8 assay, clonogenic assay, and flow cytometry. Finally, a subcutaneous nude mouse model of HCC was used to evaluate the in vivo effects of Res combined with Gem. RESULTS: Res inhibited HCC cell proliferation, induced apoptosis and G2/M arrest, and suppressed invasion in a concentration-dependent manner. Network pharmacology and TCGA analysis identified TYMS as an important target gene for Res. TYMS was highly expressed in HCC tissues and correlated with poor prognosis. Res treatment reduced TYMS expression, while molecular docking and simulation showed stable binding of Res to TYMS. TYMS levels were elevated in HuH-7/GR resistant cells. Res combined with Gem was found to reverse drug resistance, inhibit proliferation and colony formation, and induce apoptosis. The Res + Gem combination group showed the smallest tumor volume in the in vivo model. CONCLUSION: By attenuating Gem resistance through TYMS inhibition, Res holds promise as a clinically viable adjunct to Gem-based chemotherapy, offering a potential strategy to improve outcomes in HCC patients.

Resveratrol↗

PubMed2026

Identification and validation of an alternatively spliced novel isoform of maspin that modulate genes involved in inflammatory and apoptotic pathways.

Maspin regulates cellular adhesion, migration, apoptosis, angiogenesis, and tumor suppression in a tissue and context-dependent manner. Its functional diversity is governed largely thorough extracellular matrix interactions, subcellular localization, and the reactive center loop (RCL), although the structural details are not well understood. To examine whether alternative splicing contributes to this heterogeneity, we analysed the SERPINB5 gene using a computational genomics approach and identified a novel 80 bp coding exon upstream of the first coding exon (E1). The alternatively spliced transcript was validated in human skin and esophagus by semi-nested touchdown PCR, quantitative real-time PCR, and Sanger sequencing. Recombinant B5N displayed a red-shifted fluorescence emission spectrum, indicating a more solvent-exposed conformation, which was supported by molecular dynamics simulations showing greater exposure of the nuclear localization signal (NLS) and the reactive center loop. Enzyme kinetic assays demonstrated concentration-dependent enhancement of tissue plasminogen activator (tPA) activity by both isoforms. In HaCaT cells, wildtype maspin produced stronger antiproliferative and anti-migratory effects, whereas B5N was only mildly antiproliferative. Annexin V/7-AAD staining revealed that wildtype maspin induced higher early apoptosis and cell death, while B5N produced lower overall cell death but a greater proportion of late apoptotic cells. RNA-seq of transfected HaCaT cells identified differentially expressed genes enriched in inflammatory, antiviral, and apoptotic pathways, which was validated by qPCR, and several of these were markedly upregulated in SARS-CoV-2 infected A549 cells. Thus, a novel N-terminally extended maspin isoform with differentially regulated gene profile is identified and validated in this study.

Apoptosis↗

PubMed2025

TENT5C functions as a corepressor in the ligand-bound glucocorticoid receptor and estrogen receptor α complexes.

Terminal nucleotidyltransferase 5C (TENT5C) is a noncanonical poly(A) polymerase that promotes cancer suppression. TENT5C has been proposed to mediate the susceptibility of multiple myeloma to treatment with dexamethasone, a steroid hormone analog that binds to the glucocorticoid receptor (GR). However, the relationship between TENT5C and nuclear receptor (NR) signaling remains unclear. In this study, we investigate the regulatory role of TENT5C in the GR and estrogen receptor α (ERα) ligand complexes. We find that TENT5C acts as a corepressor of both GR and ERα. Molecular dynamics simulations indicate that the third TENT5C LXXLL motif directly interacts with ERα, but not GR. The physical interaction of TENT5C and ERα is supported by co-immunoprecipitation assays. Reporter assays show that mutations to the third TENT5C LXXLL motif disrupt TENT5C-mediated repression of ERα but do not affect the repression of the GR complex. In addition, the disruption of TENT5C poly(A) polymerase activity does not appear to affect TENT5C repression of ERα in the cell lines studied. Taken together, our findings highlight a role of TENT5C as an NR corepressor, differentially modulating GR- and ERα-induced transcriptional activity.

Receptors, Glucocorticoid↗

PubMed2026

A Computational Workflow for Prioritizing Microbial Metabolite-Associated Host Genes in Constipation-Predominant Irritable Bowel Syndrome.

No standardized computational pipeline exists for systematically prioritizing microbial metabolite-associated host genes and protein-ligand complexes from publicly available chemical, genomic, and structural databases. This article describes an eight-stage workflow that accepts a user-defined set of gut microbiota-derived metabolites and produces a ranked shortlist of candidate metabolite-associated host genes, enriched biological pathways, and structurally prioritized protein-ligand complexes for experimental follow-up. The pipeline integrates (i) chemoinformatic metabolite profiling; (ii) multi-database candidate target prediction using protein-chemical interaction and ligand-based target-prediction tool and a molecular docking program; (iii) differential gene expression analysis of publicly available transcriptomic data; (iv) target-differentially expressed gene overlap; (v) protein-protein interaction network construction and pathway enrichment; (vi) molecular docking with a molecular docking program; (vii) 200 ns molecular dynamics simulation using a molecular dynamics engine with a protein force field used for molecular dynamics simulations; and (viii) MM-PBSA binding free-energy estimation. As a worked example, nine gut microbiota-derived or microbiota-modified metabolites representing short-chain fatty acids, bile acids, tryptophan-derived metabolites, and urolithin A were processed using the public IBS-C rectal mucosal transcriptomic dataset GSE36701. The workflow ranked 17 unique predicted metabolite-associated genes that were differentially expressed in this dataset. Docking, molecular dynamics simulation, and MM-PBSA analyses structurally prioritized five metabolite-protein complexes: lithocholic acid-VDR, lithocholic acid-NR1H4/FXR, ursodeoxycholic acid-NR1H4/FXR, tryptamine-HTR2A (simulated in an explicit 1-Palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) lipid bilayer), and urolithin A-CASP3. The protocol is designed to be adaptable to other metabolite sets, disease transcriptomic datasets, and target classes; all outputs are hypothesis-generating computational predictions that require independent transcriptomic replication, protein-level validation, and functional ligand-response assays before causal or therapeutic conclusions can be drawn.

Irritable Bowel Syndrome↗

PubMed2026

Sanguinarine as a multi-target therapeutic candidate for laryngeal cancer: insights from network pharmacology, molecular dynamics and in vitro validation.

OBJECTIVE: To identify the core targets and elucidate the potential molecular mechanisms of sanguinarine (SA) against laryngeal squamous cell carcinoma (LSCC), and to validate its antitumor effects in vitro. METHODS: Potential targets of SA were predicted using SwissTargetPrediction, TargetNet, and SuperPred and intersected with LSCC-related targets obtained from the GeneCards, OMIM, and DISEASES databases. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed. A protein-protein interaction (PPI) network was constructed using the STRING database (combined score > 0.900), and topological parameters including degree centrality (DC), betweenness centrality (BC), closeness centrality (CC), eigenvector centrality (EC), and local average connectivity (LAC) were calculated in Cytoscape to identify core genes based on median thresholds. Molecular docking and 100-ns molecular dynamics (MD) simulations were conducted for epidermal growth factor receptor (EGFR), Phosphatidylinositide-3-kinase catalytic subunit alpha (PIK3CA), phosphatidylinositol-4,5-biphosphate 3-kinase catalytic subunit β (PIK3CB), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit delta (PIK3CD), and Non-Receptor Tyrosine Kinase (SRC). The effects of SA on LSCC were evaluated using CCK-8, colony formation, Transwell migration, and wound-healing assays in TU177 cells and TU212. RESULTS: A total of 213 common targets were identified, which were significantly enriched in PI3K-Akt signaling, EGFR tyrosine kinase inhibitor resistance, and adhesion- and migration-related pathways. The PPI network comprised 259 nodes and 259 edges, from which five core genes-PIK3CA, PIK3CB, PIK3CD, EGFR, and SRC-were identified. Molecular docking revealed strong binding affinities between SA and the PI3K family proteins (- 9.79 to - 10.96 kcal/mol), as well as EGFR (- 8.58 kcal/mol) and SRC (- 6.77 kcal/mol). MD simulations indicated greater stability of SA complexes with EGFR and PI3K family members compared with SRC. In vitro assays demonstrated that SA significantly inhibited TU177 cell and TU212 cell proliferation, colony formation, and migration. CONCLUSION: SA may exert anti-laryngeal cancer effects through synergistic multi-target inhibition centered on the EGFR/SRC/PI3K signaling axis, highlighting its potential as a promising therapeutic candidate for LSCC.

Humans↗

PubMed2026

A two-factor authentication mechanism licenses pilins for pilus assembly in gram-positive bacteria.

Gram-positive bacteria display virulence-associated pili that facilitate adhesion and biofilm formation. These pili are covalently polymerized by class C sortase enzymes, which selectively recognize their cognate pilin substrates amid numerous cell wall sorting signal (CWSS)-bearing proteins. The molecular basis for this stringent substrate specificity has remained unclear. Here, we develop a rapid, quantitative fluorescence-activated cell sorting assay to monitor pilus assembly in Corynebacterium diphtheriae, enabling high-throughput analysis of SpaA pilin and SrtA sortase variants. Using this platform, together with molecular modeling and dynamics simulations, we show that SrtA engages nearly the entire SpaA CWSS to form a membrane-embedded complex that incorporates not only the LPXTG motif but also its connector and transmembrane helix elements. Formation of this interface displaces an inhibitory active-site lid and activates the enzyme to load the pilin substrate. Systematic CWSS swapping experiments and deep mutational scanning further support this model, demonstrating that noncognate pilins are excluded because they fail to form the required interface. Conversely, SrtA variants with an artificially unlatched lid bypass the need for this interface, indicating that membrane-driven complex formation is important for substrate licensing. Together, these findings define a "two-factor authentication" mechanism for pilus assembly in gram-positive bacteria: class C sortases first verify pilin identity by forming a membrane-embedded interface that activates the enzyme, then they recognize the LPXTG motif to initiate loading and crosslinking. This work provides a unified molecular framework for selective pilin incorporation in gram-positive bacteria and identifies potential vulnerabilities in the licensing machinery that may be exploited therapeutically.

Fimbriae, Bacterial↗