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Exploring potential targets and molecular mechanisms of traumatic brain injury exacerbated by Benzo(a)pyrene via network toxicology and molecular dynamics simulation.

Benzo(a)pyrene (BaP) is a common environmental pollutant from combustion sources that promotes oxidative stress, neuroinflammation and disruption of blood-brain barrier (BBB). However, its contribution to worsening traumatic brain injury (TBI) remains unclear. In this study, we aimed to assess the contribution of BaP to secondary injury in TBI. By integrating data from e.g., the Comparative Toxicogenomics Database, GeneCards, and Online Mendelian Inheritance in Man, 121 overlapping core targets were identified between BaP and TBI. Enrichment analyses via Gene Ontology and Kyoto Encyclopedia of Genes and Genomes, combined with protein-protein interaction networks and topological algorithms (degree, closeness centrality, betweenness centrality, average shortest path length, topological coefficient and partner of multi-edged node pairs), highlighted five hub genes (TP53, EGFR, AKT1, ACTB, and TNF) implicated in mitogen-activated protein kinase signaling, oxidative stress, and neuroinflammation. Molecular docking showed strong binding affinities of BaP to these hub proteins, with energies from -9.3 to -12.1&#xa0;kcal/mol, tighter than co-crystal ligands and existing protein-binding drugs. Molecular dynamics simulations confirmed interaction stability through low root-mean-square deviation (<&#x2009;0.5&#xa0;nm), fluctuation, and radius of gyration values. Calculation of binding free energies using MM-PBSA validated the strong binding affinity between BaP and binding pockets of each hub genes. Toxicity prediction analysis revealed an oral LD50 of 316&#xa0;mg/kg for BaP, with high probabilities for neurotoxicity, BBB permeability, carcinogenicity, and mutagenicity, associated with aryl hydrocarbon receptor activation. These findings reveal a "neurovascular homeostasis disruption" network underlying BaP-exacerbated TBI pathology and highlight potential targets to reduce pollution-related risks in TBI management.

Benzo(a)pyrene

Molecular profiling of pancreatic acinar cell carcinoma and amphicrine-like carcinoma: high frequency of homologous recombination deficiency and molecular heterogeneity.

BACKGROUND: The 6th edition of the WHO Classification of Digestive System Tumours distinguishes amphicrine-like carcinomas (ALCs) from mixed neuroendocrine-non-neuroendocrine neoplasms (MiNENs). Acinar cell carcinomas (ACCs) with an intimately admixed and not separated neuroendocrine component comprising >30% of the tumour are classified as amphicrine-like ACCs (AL-ACCs). We characterised the genomic landscape of pancreatic ACCs and AL-ACCs to validate current classification and identify therapeutic targets. METHODS: Among 2,151 pancreatic biopsy and resection cases that underwent targeted next-generation sequencing using the OncoPanel AMC v4.3 or v4.5 (DNA-based hybrid capture, targeting 323 genes (v4.3) or 343 genes (v4.5)), eight ACCs, seven AL-ACCs originally diagnosed as MiNENs under the 5th edition of the WHO classification scheme, and four neuroendocrine tumours (NETs) were identified, diagnosed between 2020 and 2026. RESULTS: Homologous recombination deficiency (HRD)-associated alterations, involving BRCA1/2, ATM and FANCD2, were identified in 87.5% (7/8) of ACCs and 29% of AL-ACCs. One ACC had an ATRX nonsense mutation. Genomic heterogeneity was observed in molecular profiling of AL-ACCs; two demonstrated a 'true hybrid' signature with co-occurrence of lineage-specific drivers: MEN1 deletion and splice site mutation (neuroendocrine-associated), APC, SMAD4 and CTNNB1 alterations (exocrine-associated). Two others exhibited 'ACC-like' signatures, including missense BRCA1 and nonsense TP53 mutations and MDM4 and AKT3 amplifications, located on chromosome 1q, despite their neuroendocrine differentiation. CONCLUSIONS: Pancreatic ACCs frequently harbour HRD-related alterations, suggesting potential for PARP-inhibitor therapy. AL-ACCs comprise molecularly heterogeneous groups, including true hybrid and ACC-like patterns. Larger studies are required to elucidate the molecular distinction between true hybrid AL-ACCs and those with single-lineage alterations to refine their classification.

acinar

Characterization of human high molecular weight kininogen. Procoagulant activity associated with the light chain of kinin-free high molecular weight kininogen.

Human high molecular weight (HMW) kininogen has been isolated and was found to be a single chain protein of approximately equal to 120,000 daltons. Upon digestion with plasma kallikrein bradykinin is generated, and SDS gel electrophoresis of the kinin-free protein reveals an apparent loss in size of 15,000 daltons. The kinin-free kininogen retains full activity as a coagulation factor and consists of two chains: a heavy chain of approximately equal to 66,000 daltons disulfide-linked to a light chain of 37,000 daltons. The heavy chain of HMW kininogen shares antigenic determinants with LMW kininogen and possesses no detectable coagulant activity. The isolated light chain is shown to be responsible for the coagulant activity of HMW kininogen and contains a unique antigenic determinant that distinguishes HMW kininogen from low molecular weight kininogen.

Blood Coagulation Factors

Molecular forms of Electrophorus acetylcholinesterase. Molecular weight and composition.

Molecular weights for the series of six Electrophorus acetylcholinesterase forms have been determined either by the sedimentation-diffusion equilibrium method or, particularly in the case of the very scarce G' and G inches forms, from their Stokes radius and sedimentation coefficient values. Both methods are in excellent agreement. The results provide good evidence for the model previously proposed, G inches, G' and G containing one, two and four subunits, whereas A, C and D possess, in addition to respectively one, two and three tetrameric sets of such subunits, a structural element, the tail. Although the amino acid composition of 'tailed' and globular forms did not reveal any significant feature of this element, its mass, about 100 000 daltons, could be deduced from a comparison of molecular weights for the two classes of acetylcholinesterase forms. This value is in close agreement with electron microscopic data. The tail is thought to consist of three 30 000-dalton strands.

Acetylcholinesterase

Conversion of high molecular weight human epidermal growth factor (hEGF)/urogastrone (UG) to small molecular weight hEGF/UG by mouse EGF-associated arginine esterase.

Human epidermal growth factor (hEGF) has previously been isolated from urine and appears to be identical to beta-urogastrone (UG), an inhibitor of stimulated gastric acid secretion. A high molecular weight (HMW) form of hEGF/UG has recently been found in human urine which is fully immunoreactive but is less bioactive as measured by receptor binding activity. A specific arginine esterase, the EGF-binding protein from mouse submandibular glands, was capable of cleaving HMW-hEGF to yield a small molecular weight (SMW)-hEGF with full immunoreactivity and bioactivity, whereas trypsin produced a SMW-hEGF with much less bioactivity. SMW-hEGF produced by the arginine esterase appeared to be immunologically, biologically (both by receptor binding and mitogenic activity) and chromatographically similar to highly purified hEGF. These data suggest that HMW-hEGF may play a precursor role in the biosynthesis of hEGF/UG in man.

Animals

[Molecular weight of human alpha2-H-ferroglobulin subunits. Comparison with molecular weight of ferritin subunits].

alpha2 H globulin, a glycoferroprotein, was first demonstrated in the sera of patients with malignant diseases. This protein was isolated from cancerous human liver, and compared with ferritin, a ferroprotein showing some identical properties (presence of iron, high molecular weight, common antigenic determinants). However, physicochemical differences were observed between these two proteins. The study of protein dissociation was performed by polyacrylamide gel electrophoresis in sodium dodecyl sulfate after reduction by mercaptoethanol. A similar molecular weight of 19 000 is obtained for subunits of these two proteins. This value agrees well with the results obtained by other authors for ferritin.

Ferritins

Plasma high molecular weight kininogen concentration in health and in chosen impairments of haemostasis. Evidence that plasmin uncovers a new antigenic site in high molecular weight kininogen.

High molecular weight kininogen (HMW-kininogen) concentration was measured in the plasma of healthy blood donors, patients with haemophilia A, idiopathic thrombocytopoenic purpura, deep vein thrombosis treated with oral anticoagulants and patients treated with streptokinase (SK). The concentration of HMW-kininogen in the plasma of healthy subjects was 92 +/- 15 micrograms/ml. The values obtained in patients' plasma were not different statistically. In the plasma of patients treated with repeated infusion of SK, a significant increase of HMW-kininogen antigen activity was noted after each injection of the drug. Similar results were obtained when SK was added to plasma "in vitro" or when a purified preparation of HMW-kininogen was treated with plasmin. These and additional data obtained suggest that plasmin uncovers in the HMW-kininogen molecule a new antigenic site(s) common to HMW-kininogen and low molecular weight kininogen and new antigenic site(s) specific only for HMW-kininogen.

Absorption

Molecular weights and molecular-weight distributions from ultracentrifugation of nonideal solutions.

Ultracentrifugation, membrane osmometry and capillary viscometry experiments have been performed on two dextran samples, which have molecular-weight distributions (MWDs) similar to those of dextrans used as blood plasma extenders. The manufacturer reported values of Mn and MW, determined by end group analysis and by light scattering, respectively. Our values of Mn, determined by osmometry, and MW, calculated from ultracentrifugal and viscometry experiments, agreed quite well with the manufacturer's results. Good agreement was obtained with values of MW and BLS (the light scattering second virial coefficient) obtained from sedimentation equilibrium experiments at different speeds using sector or nonsector-shaped centerpieces. Several ways of obtaining MW, MZ and BLS from sedimentation equilibrium experiments are presented. We have also shown how to obtain the speed-dependent term of the sedimentation equilibrium second virial coefficient. Both BLS and the speed-dependent nonideal terms could be used to correct the sedimentation equilibrium data, so that ideal values of d in c/d(r2) or dc/d(r2) could be estimated and used to obtain the MWDs of the dextran samples. Both Donnelly's and Scholte's methods were used with the sedimentation equilibrium data. With both methods, unimodal MWDs were encountered, which gave good agreement with the manufacturer's MWDs, obtained by a combination of analytical gel chromatography and light scattering. Uncorrected sedimentation equilibrium data gave MWDs quite different from the manufacturer's results. The MWD calculated from the differential distribution of sedimentation coefficients also gave a unimodal MWD, but this MWD did not give a good agreement with the sedimentation equilibrium results or with the manufacturer's results.

Dextrans