Functional and structural dissection of glycosyltransferases underlying the glycodiversity of wolfberry-derived bioactive ingredients lycibarbarspermidines.

Lycibarbarspermidines are unusual phenolamide glycosides characterized by a dicaffeoylspermidine core with multiple glycosyl substitutions, and serve as a major class of bioactive ingredients in the wolfberry. So far, little is known about the enzymatic basis of the glycosylation of phenolamides including dicaffeoylspermidine. Here, we identify five lycibarbarspermidine glycosyltransferases, LbUGT1-5, which are the first phenolamide-type glycosyltransferases and catalyze regioselective glycosylation of dicaffeoylspermidines to form structurally diverse lycibarbarspermidines in wolfberry. Notably, LbUGT3 acts as a distinctive enzyme that catalyzes a tandem sugar transfer to the ortho-dihydroxy group on the caffeoyl moiety to form the unusual ortho-diglucosylated product, while LbUGT1 accurately discriminates caffeoyl and dihydrocaffeoyl groups to catalyze a site-selective sugar transfer. Crystal structure analysis of the complexes of LbUGT1 and LbUGT3 with UDP, combined with molecular dynamics simulations, revealed the structural basis of the difference in glycosylation selectivity between LbUGT1 and LbUGT3. Site-directed mutagenesis illuminates a conserved tyrosine residue (Y389 in LbUGT1 and Y390 in LbUGT3) in PSPG box that plays a crucial role in regulating the regioselectivity of LbUGT1 and LbUGT3. Our study thus sheds light on the enzymatic underpinnings of the chemical diversity of lycibarbarspermidines in wolfberry, and expands the repertoire of glycosyltransferases in nature.

Pulpwood holocellulose model transfer based on screening with consistent and stable signals algorithm.

In this study, in order to realize the sharing of the near-infrared analysis model of holocellulose between three spectral instruments of the same type, 84 pulp samples and their content of holocellulose were taken as the research objects. The effects of 10 pre-processing methods, such as 1st derivative (D1st), 2nd derivative (D2nd), multiplicative scatter correction (MSC), standard normal variable transformation (SNV), autoscaling, normalization, mean centering and pairwise combination, on the transfer effect of the stable wavelength selected by screening wavelengths with consistent and stable signals (SWCSS) were discussed. The results showed that the model established by the wavelength selected by the SWCSS algorithm after the autoscaling pre-processing method had the best analysis effect on the two target samples. Root mean square error of prediction (RMSEP) decreased from 2.4769 and 2.3119 before the model transfer to 1.2563 and 1.2384, respectively. Compared with the full-spectrum model, the value of AIC decreased from 3209.83 to 942.82. Therefore, the autoscaling pre-processing method combined with SWCSS algorithm can significantly improve the accuracy and efficiency of model transfer and provide help for the application of SWCSS algorithm in the rapid determination of pulp properties by near-infrared spectroscopy (NIRS).

Bronchial thermoplasty decreases airway remodeling by inhibiting autophagy via the AMPK/mTOR signaling pathway.

Bronchial thermoplasty (BT), an effective treatment for severe asthma, requires heat to reach the airway to reduce the mass of airway smooth muscle cells (ASMCs). Autophagy is involved in the pathological process of airway remodeling in patients with asthma. However, it remains unclear whether autophagy participates in controlling airway remodeling induced by BT. In this study, we aim to elucidate the autophagy-mediated molecular mechanisms in BT. Our study reveal that the number of autophagosomes and the level of alpha-smooth muscle actin (α-SMA) fluorescence are significantly decreased in airway biopsy tissues after BT. As the temperature increased, BT causes a decrease in cell proliferation and a concomitant increase in the apoptosis of human airway smooth muscle cells (HASMCs). Furthermore, increase in temperature significantly downregulates cellular autophagy, autophagosome accumulation, the LC3II/LC3I ratio, and Beclin-1 expression, upregulates p62 expression, and inhibits the AMPK/mTOR pathway. Furthermore, cotreatment with AICAR (an AMPK agonist) or RAPA (an mTOR antagonist) abolishes the inhibition of autophagy and attenuates the increase in the apoptosis rate of HASMCs induced by the thermal effect. Therefore, we conclude that BT decreases airway remodeling by blocking autophagy induced by the AMPK/mTOR signaling pathway in HASMCs.

Mechanism of KDM5A-mediated H3K4me3 modification in the osteogenic differentiation of mesenchymal stem cells in steroid-induced osteonecrosis of the femoral head.

OBJECTIVES: Steroid-induced osteonecrosis of the femoral head (SONFH) is characterized by impaired osteogenesis in bone marrow mesenchymal stem cells (BMSCs). This study investigates the role of lysine-specific demethylase 5A (KDM5A) in SONFH to identify potential therapeutic targets. METHODS: Human BMSCs were isolated and characterized for cell surface markers and differentiation capacity. A SONFH cell model was established using dexamethasone treatment. BMSCs were transfected with KDM5A overexpression vectors or si-KDM5A, and the expression of KDM5A, miR-107, runt-related transcription factor 2 (RUNX2), osteocalcin (OCN), and osteopontin (OPN) was assessed. Alizarin red staining was used to observe mineralization nodules, while alkaline phosphatase activity and cell viability were measured. The enrichment of KDM5A and histone 3 lysine 4 trimethylation (H3K4me3) on the promoters of RUNX2, OCN, and OPN was analyzed. The binding between miR-107 and KDM5A 3'UTR was validated, and the combined effect of miR-107 overexpression and KDM5A overexpression on BMSC osteogenic differentiation was evaluated. RESULTS: KDM5A was upregulated in BMSCs from SONFH. Inhibition of KDM5A promoted osteogenic differentiation of BMSCs, associated with increased RUNX2, OCN, and OPN promoters. KDM5A bound to the promoters of RUNX2, OCN, and OPN, leading to reduced H3K4me3 levels and downregulation of their expression. Overexpression of miR-107 inhibited KDM5A and enhanced BMSC osteogenic differentiation. CONCLUSION: KDM5A negatively regulates BMSC osteogenic differentiation by modulating H3K4me3 levels on the promoters of key osteogenic genes. miR-107 overexpression counteracts the inhibitory effect of KDM5A on osteogenic differentiation. These findings highlight the potential of targeting the KDM5A/miR-107 axis for SONFH therapy.

Photodynamic therapy for treatment of recurrent hemoptysis secondary to pulmonary endometriosis: a case report.

Pulmonary endometriosis (PEM) is rare, and drug therapy remains the primary treatment. However, patients with PEM frequently experience recurrent hemoptysis that is refractory to pharmacological intervention. We herein describe a patient with PEM who developed recurrent hemoptysis and was successfully treated with photodynamic therapy (PDT) after drug withdrawal. The patient was admitted to our hospital because of recurrent hemoptysis despite repeated drug treatments for more than 1 year. Given that PDT targets specific tissues and destroys vascular endothelial cells through the cytotoxic effect produced by the photodynamic reaction of the photosensitizer, we considered that it may effectively control hemoptysis secondary to vascular morphological changes in PEM. Therefore, we performed PDT in this case, and the patient's recurrent hemoptysis regressed. Approximately 2 years following PDT, the patient had recovered well and reported no discomfort. We recommend consideration of PDT as a treatment option for patients with PEM who develop recurrent hemoptysis after drug withdrawal. Notably, the patient's lung lesions should be superficial and limited, and no contraindications should be present.

Research on the effectiveness and safety of bronchial thermoplasty in patients with chronic obstructive pulmonary disease.

OBJECTIVES: To investigate the clinical efficacy and safety of bronchial thermoplasty (BT) in treating patients with chronic obstructive pulmonary disease (COPD). METHODS: Clinical data of 57 COPD patients were randomized into the control (n = 29, conventional inhalation therapy) or intervention group (n = 28, conventional inhalation therapy plus BT). Primary outcomes were differences in clinical symptom changes, pulmonary function-related indicators, modified Medical Research Council (mMRC), 6-min walk test (6MWT), COPD assessment test (CAT) score and acute exacerbation incidence from baseline to an average of 3 and 12 months. Safety was assessed by adverse events. RESULTS: FEV1, FEV1(%, predicted) and FVC in both groups improved to varying degrees post-treatment compared with those pre-treatment (P < 0.05). The Intervention group showed greater improving amplitudes of FEV1 (Ftime × between groups = 21.713, P < 0.001) and FEV1(%, predicted) (Ftime × between groups = 31.216, P < 0.001) than the control group, and there was no significant difference in FVC variation trend (Ftime × between groups = 1.705, P = 0.193). mMRC, 6MWT and CAT scores of both groups post-treatment improved to varying degrees (Ps < 0.05), but the improving amplitudes of mMRC (Ftime × between groups = 3.947, P = 0.025), 6MWT (Ftime × between groups = 16.988, P < 0.001) and CAT score (Ftime × between groups = 16.741, P < 0.001) in the intervention group were greater than the control group. According to risk assessment of COPD acute exacerbation, the proportion of high-risk COPD patients with acute exacerbation in the control and intervention groups at 1 year post-treatment (100% vs 65%, 100% vs 28.6%), inpatient proportion (100% vs 62.1%; 100% vs 28.6%), COPD acute exacerbations [3.0 (2.50, 5.0) vs 1.0 (1.0, 2.50); 3.0(3.0, 4.0) vs 0 (0, 1.0)] and hospitalizations [2.0 (2.0, 3.0) vs 1.0 (0, 2.0); 2.0 (2.0, 3.0) vs 0 (0, 1.0)] were significantly lower than those pre-treatment (P < 0.05). Besides, data of the intervention group were significantly lower than the control group at each timepoint after treatment (P < 0.05). CONCLUSIONS: Combined BT therapy is superior to conventional medical treatment in improving lung function and quality of life of COPD patients, and it also significantly reduces the COPD exacerbation risk without causing serious adverse events.

Oxidative aromatization mechanism of ligustilide.

The aromatization mechanisms of ligustilide (1), a versatile monomeric phthalide, were investigated. DFT calculations combined with control experiments prove that the aromatization could result from direct oxidation by triplet oxygen in mild conditions with no catalyst, which is generally thought to be difficult. Moreover, it is predicted that the aromatization could rapidly clear away the harmful-to-organism singlet oxygen, which may be relevant to the general antioxidation activity of phthalides, providing a new point of view to understand the bioactivity from chemical reaction.

Enantioselective synthesis of α,α-diarylketones by sequential visible light photoactivation and phosphoric acid catalysis.

Chiral ketones and their derivatives are useful synthetic intermediates for the synthesis of biologically active natural products and medicinally relevant molecules. Nevertheless, general and broadly applicable methods for enantioenriched acyclic α,α-disubstituted ketones, especially α,α-diarylketones, remain largely underdeveloped, owing to the easy racemization. Here, we report a visible light photoactivation and phosphoric acid-catalyzed alkyne-carbonyl metathesis/transfer hydrogenation one-pot reaction using arylalkyne, benzoquinone, and Hantzsch ester for the expeditious synthesis of α,α-diarylketones with excellent yields and enantioselectivities. In the reaction, three chemical bonds, including C═O, C─C, and C─H, are formed, providing a de novo synthesis reaction for chiral α,α-diarylketones. Moreover, this protocol provides a convenient and practical method to synthesize or modify complex bioactive molecules, including efficient routes to florylpicoxamid and BRL-15572 analogs. Computational mechanistic studies revealed that C-H/π interactions, π-π interaction, and the substituents of Hantzsch ester all play crucial roles in the stereocontrol of the reaction.

Rapid weaning from mechanical ventilation and bronchial thermoplasty for near-fatal asthma: A case report.

Background: The action mechanism of bronchial thermoplasty (BT) is poorly understood. Generally, patients with severe asthma who are in desperate need of treatment have relatively low baseline values. In this paper, we describe the case of an asthmatic patient who was saved by a combination of therapy and bronchial thermoplasty. Case information: A patient with near-fatal asthma was initially treated in our hospital with conventional medication, but his condition did not improve. The patient was next subjected to invasive mechanical ventilation, which did not provide significant relief. Additionally, he was treated with BT in conjunction with mechanical ventilation, which promptly reversed his status asthmaticus and stabilized his condition. Conclusion: Patients with near-fatal asthma who do not react effectively to aggressive therapy may benefit from BT.

Dietary selection of metabolically distinct microorganisms drives hydrogen metabolism in ruminants.

Ruminants are important for global food security but emit the greenhouse gas methane. Rumen microorganisms break down complex carbohydrates to produce volatile fatty acids and molecular hydrogen. This hydrogen is mainly converted into methane by archaea, but can also be used by hydrogenotrophic acetogenic and respiratory bacteria to produce useful metabolites. A better mechanistic understanding is needed on how dietary carbohydrates influence hydrogen metabolism and methanogenesis. We profiled the composition, metabolic pathways, and activities of rumen microbiota in 24 beef cattle adapted to either fiber-rich or starch-rich diets. The fiber-rich diet selected for fibrolytic bacteria and methanogens resulting in increased fiber utilization, while the starch-rich diet selected for amylolytic bacteria and lactate utilizers, allowing the maintenance of a healthy rumen and decreasing methane production (p < 0.05). Furthermore, the fiber-rich diet enriched for hydrogenotrophic methanogens and acetogens leading to increased electron-bifurcating [FeFe]-hydrogenases, methanogenic [NiFe]- and [Fe]-hydrogenases and acetyl-CoA synthase, with lower dissolved hydrogen (42%, p < 0.001). In contrast, the starch-rich diet enriched for respiratory hydrogenotrophs with greater hydrogen-producing group B [FeFe]-hydrogenases and respiratory group 1d [NiFe]-hydrogenases. Parallel in vitro experiments showed that the fiber-rich selected microbiome enhanced acetate and butyrate production while decreasing methane production (p < 0.05), suggesting that the enriched hydrogenotrophic acetogens converted some hydrogen that would otherwise be used by methanogenesis. These insights into hydrogen metabolism and methanogenesis improve understanding of energy harvesting strategies, healthy rumen maintenance, and methane mitigation in ruminants.

[Characteristics and Dfferences of Dissolved Oxygen Stratification in Different Tributaries of Three Gorges Reservoir During Impoundment Period].

Taking the Xiaojiang and Xiangxi Rivers, two typical tributaries of the Three Gorges Reservoir, as examples, this study analyzed and compared the hydrodynamic, thermal stratification, and temporal and spatial differences in dissolved oxygen (DO) and their responses to the water storage process in the two tributaries through field monitoring at different stages of the 2020 impoundment period. The results showed that:① at the initial stage of water storage, the DO in the surface layer of the Xiaojiang River was higher (7.00-13.00 mg·L-1) due to atmospheric reoxygenation and phytoplankton photosynthesis, and the oxycline appeared in the water depth of 3-5 m. A large area of anoxia (DO<2.00 mg·L-1) or even an anaerobic sublayer occurred in the water below 5 m. The DO in the Xiangxi River could be divided into three layers vertically:oxygen-rich surface water (8.00-12.00 mg·L-1), middle water (6.00-8.00 mg·L-1), and low-oxygen bottom water (4.00-6.00 mg·L-1). ② Thermal stratification provided a stable physical environment, whereas the upstream inflow and vegetation decomposition in the water-level fluctuation zone increased the content of organic matter, which likely increased the oxygen consumption which was conducive to the formation of an anaerobic bottom layer. In the Xiangxi River, the risk of hypoxia in the bottom water body was low because of the oxygen replenishment from the long-term downslope-bottom density current.③ Continuous monitoring also showed that the storage of the reservoir played a significant role in the replenishment of DO in tributaries, which effectively and rapidly improved the anaerobic phenomenon in the Xiaojiang River. In the Three Gorges Reservoir, it is feasible to ameliorate the water ecological problems such as anoxia and anaerobic conditions in the tributaries via reservoir operation. This study aids understanding of the characteristics and differences of DO stratification in different tributaries of the Three Gorges Reservoir, which can provide theoretical and technical support for reservoir ecological operation.

Correlation of Activation Site and Number with the Clinical Response to Bronchial Thermoplasty.

Objective: To investigate the relation of activation site and number with clinical response to bronchial thermoplasty (BT) in refractory asthma patients. Methods: This work included 106 consecutive refractory asthma patients completing three BT sessions in our hospital from May 2016 to May 2019. Procedure details included recording delivery sites and those in BT. Asthma Control Questionnaire (ACQ) scores and spirometric measurements were recorded 1-day before treatment and 6 months post-treatment to explore the effects of BT activation number and site on clinical response. Results: ACQ score (3.19±1.14 vs 1.26±0.63), forced expiratory volume in 1 sec (FEV1)% predicted (55.53±21.66 vs 66.19±22.50), FEV1 (1.53±0.74 vs 1.93±0.82), and forced vital capacity (FVC) (2.49±0.86 vs 2.92±0.94) significantly increased after three BT sessions compared with pre-session. Major bronchial ablation did not significantly improve BT response in asthma patients. Multivariate logistic regression identified baseline ACQ score and baseline FEV1% predicted as independent factors affecting the clinical response to BT. Correlation and regression analysis revealed a significant linear relationship between baseline ACQ and ACQ improvement, as well as a linear relationship between the third session activation number and ACQ improvement. Based on subgroup analysis of activation number, cohort C (activations ≥ 200) had better lung function, lower non-responding rate, and better long-term effectiveness than the other two cohorts. The activation number in the third BT session showed the strongest predictive ability compared with the first two sessions. Conclusion: Main bronchial ablation did not markedly affect clinical response to BT. Baseline ACQ and baseline FEV1% predicted were independent factors affecting clinical response to BT. Increasing the activation number might promote the therapeutic efficacy of BT, and the activation number in the third BT session correlated with and predicted the BT response.

A Novel Aurora Kinase Inhibitor Attenuates Leukemic Cell Proliferation Induced by Mesenchymal Stem Cells.

Acute myeloid leukemia (AML) mesenchymal stem cells (MSCs) play an essential role in protecting leukemic cells from chemotherapeutic agents through activating a wide range of adhesion molecules and cytokines. Thus, more attention should be paid to attenuate the protection of leukemic cells by MSCs. By examining the gene expression files of MSCs from healthy donors and AML patients through high-throughput microarrays, we found that interleukin (IL)-6 was an important cytokine secreted by AML MSCs to protect leukemic cells, contributing to disease progression. Strikingly, Aurora A (AURKA) was activated by IL-6, offering a new target to interfere with leukemia. Importantly, a novel AURKA inhibitor, PW21, showed excellent AURKA kinase inhibitory activities and attenuated the interaction of leukemic cells and the microenvironment. PW21 inhibited MSC-induced cell proliferation, colony formation, and migration, and it induced cell apoptosis. Mechanically, PW21 could inhibit IL-6 secreted by MSCs. Moreover, we found that PW21 displayed a strong anti-leukemia effect on non-obese diabetic (NOD)-severe combined immunodeficiency (SCID) and murine MLL-AF9 leukemic models. PW21 significantly prolonged the survival of leukemic mice and eliminated the leukemic progenitor cells. AURKA inhibitor PW21 could provide a new approach for treatment of leukemia through blocking the protection by the leukemic microenvironment in clinical application.

Synthesis of the impurity F of salbutamol.

First synthesis of the diastereomeric mixture of salbutamol impurity F is described in seven steps by using 4-hydroxyacetophenone as starting material, with 15.2% total yield. The synthesis provides access to multi-gram quantities of impurity F with good purity for reference supplies and further analytical and toxicology investigations. [Formula: see text].

Aurora kinase inhibitor restrains STAT5-activated leukemic cell proliferation by inducing mitochondrial impairment.

Current chemotherapy regimens on acute myeloid leukemia (AML) still have some drawbacks, such as intolerance and drug resistance, which calls need for the development of targeted therapy. Signal transducer and activator of transcription 5 (STAT5) is often overexpressed or abnormally activated in leukemia and involved in cell self-renewal, proliferation, and stress adaptation. Overexpressed Aurora A (AURKA) is associated with poor prognosis in tumors, and inhibitors against AURKA are already in clinical trials. However, it has rarely been reported whether AURKA inhibitors restrain STAT5-activated leukemia cells. In this study, we constructed STAT5 constitutively activated (cS5) cells and found that STAT5 promoted cell proliferation and colony formation. Moreover, cS5 cells showed elevated reactive oxygen species (ROS) and adenosine triphosphate (ATP) levels, which indicated higher mitochondrial metabolism in cS5 cells. A novel AURKA inhibitor AKI604 was synthesized and showed significant inhibitory effects to the proliferation and colony formation in both STAT5 constitutively activated and nonactivated AML cells. AKI604 induced mitochondrial impairment, leading to the disruption of mitochondrial membrane potential and the elevation of ROS as well as cellular calcium (Ca2+ ) levels. AKI604 could also decline basal oxygen consumption rate and ATP biosynthesis, indicating the damage of oxidative phosphorylation. Furthermore, AKI604 exhibited significant antitumor effect in the HL-60 cS5 xenograft model of the BALB/c nude mice without an obvious influence on mice body weight and other healthy indicators. This study suggested that AKI604 was a potential strategy to overcome STAT5-induced leukemic proliferation in AML treatment by inducing mitochondrial impairment.

Molecular method for rapid detection of the red tide dinoflagellate Karenia mikimotoi in the coastal region of Xiangshan Bay, China.

The species Karenia mikimotoi is a common nearshore red tide alga that can secrete hemolytic exotoxin and ichthyotoxin, which can induce the death of fish and shellfish, causing severe economic losses. In this study, loop-mediated isothermal amplification (LAMP) was employed in combination with the lateral flow dipstick (LFD) visual detection method to establish the LAMP-LFD rapid detection method for K. mikimotoi. The internal transcribed spacer ITS1-5.8S-ITS2 of K. mikimotoi was used as the target sequence and was amplified with specific primers designed in this study. The results indicated that the amplification optimal reaction conditions for LAMP in this paper were for 20 min at 65 °C. Moreover, LAMP had excellent specificity, showing negative results for other common red tide causing algal species. In field samples, we successfully reduced the total time, with only 23 min needed from LAMP amplification to LFD result display, which was shorter than that of conventional PCR. Consequently, LAMP-LFD should be useful for rapid field detection of low-density K. mikimotoi and for the early prevention of red tide induced by such algae.

[Spatial Distribution Characteristics of Chlorophyll-a and Nutrient Salts in Tributaries of Different River Sections in the Three Gorges Reservoir Area During the Flood Season].

The construction of the Three Gorges Reservoir has had certain effects on the ecological environment of the water and serious phytoplankton blooms have occurred in its tributary embayment. To explore the spatial distribution of nitrogen and phosphorus nutrients and chlorophyll-a in different tributaries of the Three Gorges Reservoir, a water quality study (June 2018) was conducted in the Xiangxi River, Shengnongxi River, and Daning River of the Three Gorges Reservoir. The results showed that the average TN in the three tributaries was 1.86 mg·L-1, 1.90 mg·L-1, and 1.43 mg·L-1, respectively, and average TP was 0.09 mg·L-1, 0.07 mg·L-1, and 0.05 mg·L-1, respectively. Single-factor ANOVA analysis showed that the spatial difference in TN was significant and occurred in the following order:Shennongxi River > Xiangxi River > Daning River. There were significant differences in the spatial distribution of TP, which were in the order off Xiangxi River > Shennongxi River > Daning River. The mean concentrations of chlorophyll-a in the three tributaries was 6.41 µg·L-1, 21.39 µg·L-1, and 9.85µg·L-1, respectively. The results from the Pearson correlation analysis, showed that chlorophyll-a concentrations were closely related to TP distribution in all tributaries, but Zeu/Zmix was also correlated with the distribution of chlorophyll-a in the Shennongxi River and Daning River. The ratio of TN and TP concentrations was 22.36, 26.76, and 28.6, respectively, which revealed that TP is a critical and limiting factor affecting phytoplankton growth in its tributary embayment.

Integrative Bioinformatics Analysis Reveals Potential Gene Biomarkers and Analysis of Function in Human Degenerative Disc Annulus Fibrosus Cells.

Low back pain is a major cause of disability worldwide. Although numerous potential biomarkers for the early diagnosis or treatment of intervertebral disc degeneration (IDD) have been identified subsequent to the development of molecular biology technologies, the mechanisms of IDD remain unknown. Published studies found the unbalance of anabolism and catabolism of annulus fibrosus (AF) played an important role in it. The present study was aimed to identify the potential targets and signaling pathways of IDD, through the combined analysis of differential expression and based on the Gene Expression Omnibus (GEO) dataset from NCBI. PPI Networks Analysis indicated that MMP2 and AGE-RAGE signaling pathway and estrogen signaling pathway may play important roles in initiation and development of IDD. This study forecasted the pathogenesis molecular mechanism of IDD and the potential prognostic and diagnostic biomarkers, but we need to make further molecular biological experiments to confirm our assumptions.

Structure-based drug design: Synthesis and biological evaluation of quinazolin-4-amine derivatives as selective Aurora A kinase inhibitors.

Aurora kinases play critical roles in the regulation of the cell cycle and mitotic spindle assembly. Aurora A kinase, a member of the Aurora protein family, is frequently highly expressed in tumors, and selective Aurora A inhibition serves as a significant component of anticancer therapy. However, designing highly selective Aurora A inhibitors is difficult because Aurora A and B share high homology and differ only by three residues in their ATP-binding pockets. Through structure-based drug design, we designed and synthesized a series of novel quinazolin-4-amine derivatives. These derivatives act as selective Aurora A kinase inhibitors by exploiting the structural differences between Aurora A and B. The selectivities of most compounds were improved (the best up to >757-fold) when comparing with the lead compound (3-fold). In vitro biochemical and cellular assays revealed that compound 6 potently inhibited Aurora A kinase and most human tumor cells. Furthermore, compound 6 effectively suppressed carcinoma, such as triple-negative breast cancers (TNBC) in an animal model. Therefore, compound 6 might serve as a promising anticancer drug. Moreover, through molecular dynamic (MD) analysis, we have identified that a salt bridge formed in Aurora B is key contributor for the isoform selectivity of the inhibitor. This salt bridge has not been previously detected in the reported crystal structure of Aurora B. These results might provide a crucial basis for the further development of highly potent inhibitors with high selectivity for Aurora A.

A Myb transcription factor represses conidiation and cephalosporin C production in Acremonium chrysogenum.

Acremonium chrysogenum is the industrial producer of cephalosporin C (CPC). We isolated a mutant (AC554) from a T-DNA inserted mutant library of A. chrysogenum. AC554 exhibited a reduced conidiation and lack of CPC production. In consistent with it, the transcription of cephalosporin biosynthetic genes pcbC and cefEF was significantly decreased in AC554. Thermal asymmetric interlaced polymerase chain reaction (TAIL-PCR) was performed and sequence analysis indicated that a T-DNA was inserted upstream of an open reading frame (ORF) which was designated AcmybA. On the basis of sequence analysis, AcmybA encodes a Myb domain containing transcriptional factor. Observation of red fluorescent protein (RFP) tagged AcMybA showed that AcMybA is naturally located in the nucleus of A. chrysogenum. Transcriptional analysis demonstrated that the AcmybA transcription was increased in AC554. In contrast, the AcmybA deleted mutant (ΔAcmybA) overproduced conidia and CPC. To screen the targets of AcmybA, we sequenced and compared the transcriptome of ΔAcmybA, AC554 and the wild-type strain at different developmental stages. Twelve differentially expressed regulatory genes were identified. Taken together, our results indicate that AcMybA negatively regulates conidiation and CPC production in A. chrysogenum.