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Austocystin D is a natural compound that induces cytochrome P450 (CYP) monooxygenase-dependent DNA damage and growth inhibition in certain cancer cell lines. Cancer cells exhibiting higher sensitivity to austocystin D often display elevated CYP2J2 expression. However, the essentiality and the role of CYP2J2 for the cytotoxicity of this compound remain unclear. In this study, we demonstrate that CYP2J2 depletion alleviates austocystin D sensitivity and DNA damage induction, while CYP2J2 overexpression enhances them. Moreover, the investigation into genes involved in austocystin D cytotoxicity identified POR and PGRMC1, positive regulators for CYP activity, and KAT7, a histone acetyltransferase. Through genetic manipulation and analysis of multiomics data, we elucidated a role for KAT7 in CYP2J2 transcriptional regulation. These findings strongly suggest that CYP2J2 is crucial for austocystin D metabolism and its subsequent cytotoxic effects. The potential use of austocystin D as a therapeutic prodrug is underscored, particularly in cancers where elevated CYP2J2 expression serves as a biomarker.
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BACKGROUND: Pancreaticoduodenectomy (PD) is considered a challenging surgery for resecting the gastroduodenal artery (GDA), right gastric artery (RGA), and lymph node tumors. In cases of pancreatic head cancer surgery, vascular anastomosis or right gastroepiploic artery (RGEA)/GDA preservation is necessary after postoperative gastric tube reconstruction for esophageal cancer. Therefore, we report for the first time an extremely rare case of PD in a patient with pancreatic head cancer and median arcuate ligament syndrome (MALS) after gastric tube reconstruction following esophageal cancer surgery, in which the entire pancreatic head arcade was preserved. CASE PRESENTATION: The patient was a 76-year-old man who had undergone esophageal cancer surgery after sternal gastric tube reconstruction 7 years ago. He was referred to our hospital because of the suspicion of intraductal papillary mucinous carcinoma (IPMC) owing to an enlarged cystic lesion and a substantial component in the uncinate process of the pancreas. Preoperative three-dimensional computed (3D-CT) tomography angiography showed celiac axis stenosis and pancreatic head arcade dilation. The diagnosis was IPMC without evidence of invasion; therefore, gastric tube blood flow was maintained by preserving the GDA and RGEA. Due to MALS, the GDA blood flow was supplied through the pancreatic head arcade, necessitating its preservation. The GDA-RGEA, right gastroepiploic vein, and anterior superior pancreaticoduodenal artery were taped over the entire pancreatic head for preservation. The inferior pancreaticoduodenal artery (IPDA) was also taped on the dorsal pancreas and the posterior or anterior IPDA, which further bifurcates were taped to preserve them. Subsequently, PD was performed. CONCLUSION: We report a case of PD after gastric tube reconstruction for esophageal cancer with MALS, in which the pancreatic head arcade vessels were successfully preserved using 3D-CT to confirm the operation of the vessels.
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This study investigates the particle size threshold at which the interdigestive migrating motor complex (IMMC) becomes active in gastric emptying for fasted beagle dogs. Enteric-coated granules containing cetirizine dihydrochloride (CET) were prepared in three particle sizes, 200, 660, and 1,200 µm (D50). To mark IMMC timing and water movement from the stomach, enteric-coated aspirin tablets and acetaminophen solution were used. To six fasted beagle dogs with 50 mL of acetaminophen solution was administered each granule size as a multiple-unit and a single enteric-coated aspirin tablet (3-period crossover study). No significant difference in pharmacokinetic parameters of CET after oral administration of different particle sizes was observed. However, the appearance time of CET in plasma with smaller granules (200 and 660 µm) was significantly faster than that of salicylic acid (a major metabolite of aspirin) in all dogs. In the case of the largest granules (1,200 µm), no significant time difference was observed in the appearance of both compounds in plasma. Furthermore, in two dogs, both compounds appeared at the same time, implying IMMC-regulated gastric emptying for the largest CET granules. These results support a particle size threshold between 660 and 1,200 µm for gastric emptying without IMMC action in fasted beagle dogs.
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Background: Stent is widely regarded as the main treatment for curing cardiovascular diseases such as stenosis. Previous research has revealed that the damage of endothelial cells (EC), i.e., the components of endothelium, during stent implantation, could lead to severe complications, such as restenosis. To prevent restenosis, enhancements have been made to surface biocompatibility to accelerate the stent endothelialization process. Anodization on the Ni-Ti is a simple and efficient surface modification method to improve the biocompatibility of the Ni-Ti stent surfaces by enhancing the surface hydrophilicity, leading to an increase in the EC activities. The EC activity is known to be affected by the blood flow. Flow change by stent structure may result in EC dysfunctions, thereby leading to restenosis. It is thus essential to investigate the EC activities resulting from the anodization on the Ni-Ti surface under flow conditions. Objective: To study the influence of the endothelialization process on the Ni-Ti stent surface through anodization. The EC attachment and morphology on the anodized stent strut were observed under both with and without the flow conditions. Method: A parallel plate flow chamber was designed to generate a constant wall shear stress (WSS) to study the flow effect on the EC behavior. The hydrophilicity of the Ni-Ti stent strut surface was enhanced by a TiO2 layer fabricated via anodization. The EC distribution on the surface of the anodized nitinol stent strut was observed after 24â h of static (without flow) and flow exposure (with flow) experiment. Results: Under the static condition, the EC density on the surface of the anodized Ni-Ti stent strut was higher compared with the control. Under the flow condition, the enhancement of the EC density on the surface of the stent strut with anodization was reduced. The EC demonstrates a long and thin spindle-shaped morphology under the flow condition. Conclusion: Unlike the static condition, the EC is demonstrating a long and thin morphology in response to the flow under the flow condition. By improving the surface hydrophilicity, the anodization could enhance the EC migration onto the strut surface, and subsequently, accelerate the Ni-Ti stent endothelialization process. The improvement of the surface hydrophilicity is lower under the flow conditions when compared with the static conditions.
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PURPOSE: In drug discovery, rats are widely used for pharmacological and toxicological studies. We previously reported that a mechanism-based oral absorption model, the gastrointestinal unified theoretical framework (GUT framework), can appropriately predict the fraction of a dose absorbed (Fa) in humans and dogs. However, there are large species differences between humans and rats. The purpose of the present study was to evaluate the predictability of the GUT framework for rat Fa. METHOD: The Fa values of 20 model drugs (a total of 39 Fa data) were predicted in a bottom-up manner. Based on the literature survey, the bile acid concentration (Cbile) and the intestinal fluid volume were set to 15 mM and 4 mL/kg, respectively, five and two times higher than in humans. LogP, pKa, molecular weight, intrinsic solubility, bile micelle partition coefficients, and Caco-2 permeability were used as input data. RESULTS: The Fa values were appropriately predicted for highly soluble drugs (absolute average fold error (AAFE) = 1.65, 18 Fa data) and poorly soluble drugs (AAFE = 1.57, 21 Fa data). When the species difference in Cbile was ignored, Fa was over- and under-predicted for permeability and solubility limited cases, respectively. High Cbile in rats reduces the free fraction of drug molecules available for epithelial membrane permeation while increasing the solubility of poorly soluble drugs. CONCLUSION: The Fa values in rats were appropriately predicted by the GUT framework. This result would be of great help for a better understanding of species differences and model-informed preclinical formulation development.
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Bile , Absorção Intestinal , Humanos , Ratos , Animais , Cães , Administração Oral , Células CACO-2 , Descoberta de Drogas , Solubilidade , PermeabilidadeRESUMO
The vascular endothelial cells constitute the innermost layer. The cells are exposed to mechanical stress by the flow, causing them to express their functions. To elucidate the functions, methods involving seeding endothelial cells as a layer in a chamber were studied. The chambers are known as parallel plate, T-chamber, step, cone plate, and stretch. The stimulated functions or signals from endothelial cells by flows are extensively connected to other outer layers of arteries or organs. The coculture layer was developed in a chamber to investigate the interaction between smooth muscle cells in the middle layer of the blood vessel wall in vascular physiology and pathology. Additionally, the microfabrication technology used to create a chamber for a microfluidic device involves both mechanical and chemical stimulation of cells to show their dynamics in in vivo microenvironments. The purpose of this study is to summarize the blood flow (flow inducing) for the functions connecting to endothelial cells and blood vessels, and to find directions for future chamber and device developments for further understanding and application of vascular functions. The relationship between chamber design flow, cell layers, and microfluidics was studied.
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The purpose of the present study was to characterize current biopharmaceutics modeling and simulation software regarding the prediction of the fraction of a dose absorbed (Fa) in humans. As commercial software products, GastroPlus™ and Simcyp® were used. In addition, the gastrointestinal unified theoretical framework, a simple and publicly accessible model, was used as a benchmark. The Fa prediction characteristics for a total of 96 clinical Fa data of 27 model drugs were systematically evaluated using the default settings of each software product. The molecular weight, dissociation constant, octanol-water partition coefficient, solubility in biorelevant media, dose, and particle size of model drugs were used as input data. Although the same input parameters were used, GastroPlus™, Simcyp®, and the gastrointestinal unified theoretical framework showed different Fa prediction characteristics depending on the rate-limiting steps of oral drug absorption. The results of the present study would be of great help for the overall progression of physiologically based absorption models.
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Absorção Intestinal , Preparações Farmacêuticas , Administração Oral , Simulação por Computador , Humanos , Modelos Biológicos , Permeabilidade , Software , SolubilidadeRESUMO
The purpose of the present study was to harmonize the protocol of equilibrium solubility measurements for poorly water-soluble drugs to lower inter-laboratory variance. The "mandatory" and "recommended" procedures for the shake-flask method were harmonized based on the knowledge and experiences of each company and information from the literature. The solubility of model drugs was measured by the harmonized protocol (HP) and the non-harmonized proprietary protocol of each company (nonHP). Albendazole, griseofulvin, dipyridamole, and glibenclamide were used as model drugs. When using the nonHP, the solubility values showed large inter-laboratory variance. In contrast, inter-laboratory variance was markedly reduced when using the HP.
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Eukaryotic structural maintenance of chromosome proteins (SMC) are major components of cohesin and condensins that regulate chromosome structure and dynamics during cell cycle. We here determine the crystal structure of human condensin SMC hinge heterodimer with ~30 residues of coiled coils. The structure, in conjunction with the hydrogen exchange mass spectrometry analyses, revealed the structural basis for the specific heterodimer formation of eukaryotic SMC and that the coiled coils from two different hinges protrude in the same direction, providing a unique binding surface conducive for binding to single-stranded DNA. The characteristic hydrogen exchange profiles of peptides constituted regions especially across the hinge-hinge dimerization interface, further suggesting the structural alterations upon single-stranded DNA binding and the presence of a half-opened state of hinge heterodimer. This structural change potentially relates to the DNA loading mechanism of SMC, in which the hinge domain functions as an entrance gate as previously proposed for cohesin. Our results, however, indicated that this is not the case for condensins based on the fact that the coiled coils are still interacting with each other, even when DNA binding induces structural changes in the hinge region, suggesting the functional differences of SMC hinge domain between condensins and cohesin in DNA recognition.
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Adenosina Trifosfatases/química , Proteínas de Transporte/química , Proteínas Cromossômicas não Histona/química , DNA de Cadeia Simples/química , Proteínas de Ligação a DNA/química , Complexos Multiproteicos/química , Proteínas Nucleares/química , Sequência de Aminoácidos , Animais , Área Sob a Curva , Bacillus , Sítios de Ligação , Calorimetria , Proteínas de Ciclo Celular/química , Clonagem Molecular , Cristalografia por Raios X , DNA/química , Análise Mutacional de DNA , Humanos , Hidrogênio/química , Espectrometria de Massas , Camundongos , Dados de Sequência Molecular , Ligação Proteica , Multimerização Proteica , Pyrococcus , Saccharomyces cerevisiae , CoesinasRESUMO
In higher eukaryotes, the condensin complex, which mainly consists of two structural maintenance of chromosomes (SMC) subunits, SMC2 (CAP-E) and SMC4 (CAP-C), plays a critical role in the formation of higher order chromosome structures during mitosis. Biochemical and electron-microscopic studies have revealed that the SMC2 and SMC4 subunits dimerize through the interaction of their hinge domains, forming a characteristic V-shaped heterodimer. However, the details of their function are still not fully understood owing to a lack of structural information at the atomic level. In this study, the human SMC2 hinge domain with short coiled coils was cloned, expressed, purified and crystallized in the orthorhombic space group C222 in native and SeMet-derivatized forms. Because of the poor diffraction properties of these crystals, the mutant Leu68-->SeMet was designed and crystallized in order to obtain the experimental phases. The SeMet-derivatized crystals of the mutant belonged to space group P3(2)12, with unit-cell parameters a=b=128.8, c=91.4 A. The diffraction data obtained from a crystal that diffracted to 2.4 A resolution were suitable for SAD phasing.
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Adenosina Trifosfatases/química , Proteínas de Ligação a DNA/química , Complexos Multiproteicos/química , Clonagem Molecular , Cristalização , Cristalografia por Raios X , Expressão Gênica , Humanos , Estrutura Secundária de ProteínaRESUMO
We describe a consanguineous family that had progressive myopathy with rimmed vacuole (RV) formation and amyloid deposition. Patient 1 is a 71-year-old woman with muscle atrophy in the lumbar girdle and lower extremities. Patient 2 is a 40-year-old man (the son of Patient 1) with fatty changes in the biceps femoris muscles. Muscle biopsies revealed myopathic and neurogenic degeneration with RV, necrotic fibers, and interstitial amyloid deposition. Amyloid deposition was detected only in the muscle tissue.