Optimization of n-butanol synthesis in Lactobacillus brevis via the functional expression of thl, hbd, crt and ter.

N-butanol is an important chemical and can be naturally synthesized by Clostridium species; however, the poor n-butanol tolerance of Clostridium impedes the further improvement in titer. In this study, Lactobacillus brevis, which possesses a higher butanol tolerance, was selected as host for heterologous butanol production. The Clostridium acetobutylicum genes thl, hbd, and crt which encode thiolase, ß-hydroxybutyryl-CoA dehydrogenase, and crotonase, and the Treponema denticola gene ter, which encodes trans-enoyl-CoA reductase were cloned into a single plasmid to express the butanol synthesis pathway in L. brevis. A titer of 40 mg/L n-butanol was initially achieved with plasmid pLY15-opt, in which all pathway genes are codon-optimized. A titer of 450 mg/L of n-butanol was then synthesized when ter was further overexpressed in this pathway. The role of metabolic flux was reinforced with pLY15, in which only the ter gene was codon-optimized, which greatly increased the n-butanol titer to 817 mg/L. Our strategy significantly improved n-butanol synthesis in L. brevis and the final titer is the highest achieved amongst butanol-tolerant lactic acid bacteria.

Discovery and Computational Analyses of Novel Small Molecule Zika Virus Inhibitors.

Zika virus (ZIKV), one of the flaviviruses, has attracted worldwide attention since its large epidemics around Brazil. Association of ZIKV infection with microcephaly and neurological problems such as Guillain-Barré syndrome has prompted intensive pathological investigations. However, there is still a long way to go on the discovery of effective anti-ZIKV therapeutics. In this study, an in silico screening of the National Cancer Institute (NCI) diversity set based on ZIKV NS3 helicase was performed using a molecular docking approach. Selected compounds with drug-like properties were subjected to cell-based antiviral assays resulting in the identification of two novel lead compounds (named Compounds 1 and 2). They inhibited ZIKV infection with IC50 values at the micro-molar level (8.5 µM and 15.2 µM, respectively). Binding mode analysis, absolute binding free energy calculation, and structure-activity relationship studies of these two compounds revealed their possible interactions with ZIKV NS3 helicase, suggesting a mechanistic basis for further optimization. These two novel small molecules may represent new leads for the development of inhibitory drugs against ZIKV.

Endovaginal coil for pelvic high-resolution magnetic resonance imaging of cervical cancer: a preliminary parameter optimization study.

Background: The diagnosis of early-stage cervical cancer through conventional magnetic resonance imaging (MRI) remains challenging, highlighting a greater need for pelvic high-resolution MRI (HR MRI). This study used our research team's endovaginal coil imaging to optimize scanning parameters and aimed to achieve HR MRI of the pelvis and determine its clinical value. Methods: Fifty participants were recruited prospectively for this cross-sectional study conducted at the First Affiliated Hospital of Chongqing Medical University from January 2023 to November 2023. Initially, 10 volunteers requiring pelvic imaging diagnosis underwent pelvic MRI with the endovaginal coil combined with a conventional external array coil to test and optimize the scanning parameters. Subsequently, 40 patients who were highly suspected or diagnosed with cervical cancer were randomly assigned to undergo an initial pelvic scan with an external array coil with subsequent examinations of both the conventional coil and the endovaginal coil. Two experienced radiologists performed quantitative analyses, measuring signals and calculating the signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and contrast (C). They also conducted qualitative analyses, evaluating imaging artifacts, anatomical structures, and overall image quality. The paired sample t-test and Wilcoxon rank-sum test were conducted to compare the statistical differences between the two sets of images, while the intraclass correlation coefficient (ICC) and Kappa consistency tests were used to assess the measurement and scoring consistency between the two radiologists. Results: The optimized endovaginal images had higher mean SNR, CNR, and C values (18.62±7.85, 16.04±7.72, and 0.73±0.11, respectively) compared to the conventional images (6.77±2.36, 4.47±2.05, and 0.47±0.12, respectively). Additionally, the ratings for imaging artifacts, anatomical structures, and overall quality of the endovaginal images were all 4 [interquartile range (IQR) 4, 4]; meanwhile, the conventional images scored lower with ratings of 4 (IQR 3, 4), 3 (IQR 3, 3), and 3 (IQR 3, 3) for SNR, CNR, and C, respectively. All analysis results underwent paired-sample t-tests or Wilcoxon rank-sum tests between the two groups, yielding a P value <0.001. The optimized endovaginal images also showed improved resolution with a reconstructed voxel size of 0.11 mm3, and HR MRI was successfully achieved. The ICC values for the measurements were 0.914, 0.947, and 0.912, respectively, and for the ratings, the measurement was 0.923, indicating excellent consistency between the two physicians (ICC/Kappa value between 0.85 and 1.00). Conclusions: Endovaginal technology, which provides precise clinical information for the diagnosis of cervical cancer, provides straightforward operation and exceptional imaging quality, making it highly suitable for expanded clinical use.

Detection, production, modification, and application of arylsulfatases.

Arylsulfatase is a subset of sulfatase which catalyzes the hydrolysis of aryl sulfate ester. Arylsulfatase is widely distributed among microorganisms, mammals and green algae, but the arylsulfatase-encoding gene has not yet been found in the genomes of higher plants so far. Arylsulfatase plays an important role in the sulfur flows between nature and organisms. In this review, we present the maturation and catalytic mechanism of arylsulfatase, and the recent literature on the expression and production of arylsulfatase in wild-type and engineered microorganisms, as well as the modification of arylsulfatase by genetic engineering are summarized. We focus on arylsulfatases from microbial origin and give an overview of different assays and substrates used to determine the arylsulfatase activity. Furthermore, the researches about arylsulfatase application on the field of agar desulfation, soil sulfur cycle and soil evaluation are also discussed. Finally, the perspectives concerning the future research on arylsulfatase are prospected.

HOXA10 Expressing UCMSCs Transplantation Improved Endometrial Receptivity on Endometrial Injury.

BACKGROUND: Endometrial injury is considered the major cause of female infertility. Traditional therapies such as estrogen substitution therapy are not satisfactory due to individual variation in response to treatment, thereby warranting the use of alternative strategies such as stem cell therapy. Transplantation of stem cells, such as umbilical cord mesenchymal stem cells (UCMSCs), has been shown to improve endometrial healing. However, due to the effect of the intrauterine environment, the therapeutic effect of UCMSCs is limited, and its efficacy is unstable. HOXA10, encoded by the HOXA10 gene, plays an important role in endometrium morphology maintenance, proliferation, differentiation, and embryo implantation. Moreover, UCMSCs do not show HOXA10 expression. OBJECTIVE: Our study aimed to evaluate the therapeutic effects of HOXA10-transfected UCMSCs on endometrial injury repair in vivo. METHODS: First, we established T10-UCMSCs (UCMSCs transfected with HOXA10) for transplantation. To establish the endometrial injury model, we injected 95% ethanol into the uterine cavity and transplanted T10-UCMSCs into the uterine cavity from the cornua uteri. Fourteen days later, uteri were collected for histological and biochemical analysis of endometrial growth and receptivity. RESULTS: Our results showed the endometrial receptivity was better in T10-UCMSCs group than in UCMSCs group, suggesting that HOXA10 could enhance the repairing ability of UCMSCs in the endometrium injury repair. More importantly, the fertility test showed that more embryos were implanted in the T10- UCMSCs group. CONCLUSION: Our results suggest that UCMSCs with HOXA10 expression could improve the therapeutic effects on endometrial injury repairing.

The CRTC-CREB axis functions as a transcriptional sensor to protect against proteotoxic stress in Drosophila.

cAMP Responsible Element Binding Protein (CREB) is an evolutionarily conserved transcriptional factor that regulates cell growth, synaptic plasticity and so on. In this study, we unexpectedly found proteasome inhibitors, such as MLN2238, robustly increase CREB activity in adult flies through a large-scale compound screening. Mechanistically, reactive oxidative species (ROS) generated by proteasome inhibition are required and sufficient to promote CREB activity through c-Jun N-terminal kinase (JNK). In 293 T cells, JNK activation by MLN2238 is also required for increase of CREB phosphorylation at Ser133. Meanwhile, transcriptome analysis in fly intestine identified a group of genes involved in redox and proteostatic regulation are augmented by overexpressing CRTC (CREB-regulated transcriptional coactivator). Intriguingly, CRTC overexpression in muscles robustly restores protein folding and proteasomal activity in a fly Huntington's disease (HD) model, and ameliorates HD related pathogenesis, such as protein aggregates, motility, and lifespan. Moreover, CREB activity increases during aging, and further enhances its activity can suppress protein aggregates in aged muscles. Together, our results identified CRTC/CREB downstream ROS/JNK signaling as a conserved sensor to tackle oxidative and proteotoxic stresses. Boosting CRTC/CREB activity is a potential therapeutic strategy to treat aging related protein aggregation diseases.

Trends in application of advancing computational approaches in GPCR ligand discovery.

G protein-coupled receptors (GPCRs) comprise the most important superfamily of protein targets in current ligand discovery and drug development. GPCRs are integral membrane proteins that play key roles in various cellular signaling processes. Therefore, GPCR signaling pathways are closely associated with numerous diseases, including cancer and several neurological, immunological, and hematological disorders. Computer-aided drug design (CADD) can expedite the process of GPCR drug discovery and potentially reduce the actual cost of research and development. Increasing knowledge of biological structures, as well as improvements on computer power and algorithms, have led to unprecedented use of CADD for the discovery of novel GPCR modulators. Similarly, machine learning approaches are now widely applied in various fields of drug target research. This review briefly summarizes the application of rising CADD methodologies, as well as novel machine learning techniques, in GPCR structural studies and bioligand discovery in the past few years. Recent novel computational strategies and feasible workflows are updated, and representative cases addressing challenging issues on olfactory receptors, biased agonism, and drug-induced cardiotoxic effects are highlighted to provide insights into future GPCR drug discovery.

Vibrio natriegens as a pET-Compatible Expression Host Complementary to Escherichia coli.

Efficient and novel recombinant protein expression systems can further reduce the production cost of enzymes. Vibrio natriegens is the fastest growing free-living bacterium with a doubling time of less than 10 min, which makes it highly attractive as a protein expression host. Here, 196 pET plasmids with different genes of interest (GOIs) were electroporated into the V. natriegens strain VnDX, which carries an integrated T7 RNA polymerase expression cassette. As a result, 65 and 75% of the tested GOIs obtained soluble expression in V. natriegens and Escherichia coli, respectively, 20 GOIs of which showed better expression in the former. Furthermore, we have adapted a consensus "what to try first" protocol for V. natriegens based on Terrific Broth medium. Six sampled GOIs encoding biocatalysts enzymes thus achieved 50-128% higher catalytic efficiency under the optimized expression conditions. Our study demonstrated V. natriegens as a pET-compatible expression host with a spectrum of highly expressed GOIs distinct from E. coli and an easy-to-use consensus protocol, solving the problem that some GOIs cannot be expressed well in E. coli.

A new class of α-ketoamide derivatives with potent anticancer and anti-SARS-CoV-2 activities.

Inhibitors of the proteasome have been extensively studied for their applications in the treatment of human diseases such as hematologic malignancies, autoimmune disorders, and viral infections. Many of the proteasome inhibitors reported in the literature target the non-primed site of proteasome's substrate binding pocket. In this study, we designed, synthesized and characterized a series of novel α-keto phenylamide derivatives aimed at both the primed and non-primed sites of the proteasome. In these derivatives, different substituted phenyl groups at the head group targeting the primed site were incorporated in order to investigate their structure-activity relationship and optimize the potency of α-keto phenylamides. In addition, the biological effects of modifications at the cap moiety, P1, P2 and P3 side chain positions were explored. Many derivatives displayed highly potent biological activities in proteasome inhibition and anticancer activity against a panel of six cancer cell lines, which were further rationalized by molecular modeling analyses. Furthermore, a representative α-ketoamide derivative was tested and found to be active in inhibiting the cellular infection of SARS-CoV-2 which causes the COVID-19 pandemic. These results demonstrate that this new class of α-ketoamide derivatives are potent anticancer agents and provide experimental evidence of the anti-SARS-CoV-2 effect by one of them, thus suggesting a possible new lead to develop antiviral therapeutics for COVID-19.