Discovery of an EP300 Inhibitor using Structure-based Virtual Screening and Bioactivity Evaluation.

BACKGROUND: EP300 (E1A binding protein p300) played a significant role in serial diseases such as cancer, neurodegenerative disease. Therefore, it became a significant target. METHODS: Targeting EP300 discovery of a novel drug to alleviate these diseases. In this paper, 17 candidate compounds were obtained using a structure-based virtual screening approach, 4449-0460, with an IC50 of 5.89 ± 2.08 uM, which was identified by the EP300 bioactivity test. 4449-0460 consisted of three rings. The middle benzene ring connected the 5-ethylideneimidazolidine-2,4-dione group and the 3-F-Phenylmethoxy group. RESULTS: Furthermore, the interaction mechanism between 4449-0460 and EP300 was explored by combining molecular dynamics (MD) simulations and binding free energy calculation methods. CONCLUSION: The binding free energy of EP300 with 4449-0460 was -10.93 kcal/mol, and mainly came from the nonpolar energy term (ΔGnonpolar). Pro1074, Phe1075, Val1079, Leu1084, and Val1138 were the key residues in EP300/4449-0460 binding with more -1 kcal/mol energy contribution. 4449-0460 was a promising inhibitor targeting EP300, which had implications for the development of drugs for EP300-related diseases.

A high-throughput UHPLC-MS/MS method for the determination of eight anti-tumor drugs in plasma.

Rapidly developing UHPLC-MS/MS bioassays with high throughput and quality are challenging yet desired in routine clinics. METHODS & RESULTS: A high-throughput UHPLC-MS/MS bioassay has been built for simultaneously quantifying gefitinib, ruxolitinib, dasatinib, imatinib, ibrutinib, methotrexate, cyclophosphamide and paclitaxel. After the protein precipitation with methanol, samples were separated on an Acquity BEH C18 column following a gradient elution system with methanol and 2 mM ammonium acetate in water at 40 °C with a run time of 3 min (flow rate 0.4 mL/min). Mass quantification in the positive ion SRM mode was then performed with electrospray ionization. The method of specificity, linearity, accuracy, precision, matrix effects, recovery, stability, dilution integrity and carryover were all validated as per the guideline of the China Food and Drug Administration whose values met the admissible limits. Application of the bioassay to therapeutic drug monitoring revealed important variability in the studied anti-tumour drugs. CONCLUSION: This validated approach was shown to be reliable and effective in clinical management, being a valuable support in therapeutic drug monitoring and subsequent individualized dosing optimization.

Tanshinone IIA ameliorates experimental diabetic cardiomyopathy by inhibiting endoplasmic reticulum stress in cardiomyocytes via SIRT1.

Diabetic cardiomyopathy (DCM) is a common complication in patients with diabetes, and ultimately leads to heart failure. Endoplasmic reticulum stress (ERS) induced by abnormal glycolipid metabolism is a critical factor that affects the occurrence and development of DCM. Additionally, the upregulation/activation of silent information regulation 2 homolog-1 (SIRT1) has been shown to protect against DCM. Tanshinone II A (Tan IIA), the main active component of Salviae miltiorrhizae radix et rhizome (a valuable Chinese medicine), has protective effects against cardiovascular disease and diabetes. However, its role and mechanisms in diabetes-induced cardiac dysfunction remain unclear. Therefore, we explored whether Tan IIA alleviates ERS-mediated DCM via SIRT1 and elucidated the underlying mechanism. The results suggested that Tan IIA alleviated the pathological changes in the hearts of diabetic mice, ameliorated the cytopathological morphology of cardiomyocytes, reduced the cell death rate, and inhibited the expression of ERS-related proteins and mRNA. The SIRT1 agonist inhibited the activities of glucose-regulated protein 78 (GRP78). Furthermore, the opposite results under the SIRT1 inhibitor. SIRT1 knockdown was induced by siRNA-SIRT1 transfection, and the degree of GRP78 acetylation was increased. Cumulatively, Tan IIA ameliorated DCM by inhibiting ERS and upregulating SIRT1 expression.

Rapid visual detection of Micropterus salmoides rhabdovirus using recombinase polymerase amplification combined with lateral flow dipsticks.

Largemouth bass (Micropterus salmoides) is an important freshwater-cultured species in China. Recently, a lethal and epidemic disease caused by Micropterus salmoides rhabdovirus (MSRV) results in huge economic losses to the largemouth bass industry. Current diagnostics for detecting MSRV are limited in sensitivity and speed and are inconvenient to be used for non-laboratory detection. In this study, three rapid and convenient detection assays of MSRV by recombinase polymerase amplification (RPA) and lateral flow dipsticks (LFD), targeting the conserved sequences of the MSRV-SS N gene, are described. With these RPA methods, the detection could achieve within 50 min at 38°C. Both methods of RPA-AGE and RPA-LFD could detect the viral DNA as low as 170 copies/µl of the MSRV standard plasmid and were 100-fold more sensitive than that in the method of routine PCR. Meanwhile, these RPA methods were highly specific for the detection of MSRV and can be feasibly applied to the diagnostic of MSRV infection. In brief, RPA-AGE, RPA-LFD and RT-RPA-LFD provide convenient, rapid, sensitive and reliable methods that could improve field diagnosis of MSRV with limited machine resources, and would enhance the production of largemouth bass.

Transcriptomic and proteomic analyses reveal new insights into the regulation of immune pathways during cyprinid herpesvirus 2 infection in vitro.

Carassius auratus gibelio is susceptible to the herpesviral hematopoietic necrosis (HVHN) disease caused by cyprinid herpesvirus 2 (CyHV-2) infection during the breeding process. Nevertheless, the report on biological response of CyHV-2 with C. auratus gibelio was limited, especially in vitro. In this study, host gene expression profiling was mostly analyzed in caudal fin cells of Carassius auratus gibelio (GiCF) underlying CyHV-2 infection. Transcriptomics and proteomics were employed to study the differential expression gene and revealed the host genes involved in pathway during the CyHV-2 infection. Transcriptome analysis revealed that compared with the control group, there were 11 335 and 19 421 differentially expressed unigenes at 48 h and at 96 h, respectively. Furthermore, proteome analysis showed that there were a total of 9008 proteins, among which 169 proteins were differential expression in the 48 h group and 502 proteins in the 96 h group. Notably, 10 and 158 differentially co-expressed genes at mRNA and protein levels (cDEGs) were reliably quantified at 48 h and 96 h, respectively. Interestingly, significantly different expressed genes both in the transcriptome and the proteome were identified, including GNG7, Hsp90a, THBS1 and RRM2. The result suggested that PI3k-AKT pathway was activated, but the p53 signaling pathway was suppressed. The above result will lay the foundation for understanding the mechanisms of host defense virus invasion during CyHV-2 infection.