Synthesis and biological evaluation of 1H-pyrrolo[3,2-g]isoquinolines

A structure-activity relationship study performed on 1H-pyrrolo[3,2-g]isoquinoline scaffold identified new haspin inhibitors with nanomolar potencies and selectivity indices (SI) over 6 (inhibitory potency evaluated against 8 protein kinases). Compound 22 was the most active of the series (haspin IC50 = 76 nM). Cellular evaluation of 22 confirmed its activity for endogenous haspin in U-2 OS cells and its anti-proliferative activity against various cell lines. In addition, the binding mode of analog 22 in complex with haspin was determined by X-ray crystallography.

A review of microbial responses to biochar addition in anaerobic digestion system: Community, cellular and genetic level findings

The biochar is a well-developed porous material with various excellent properties, that has been proven with excellent ability in anaerobic digestion (AD) efficiency promotion. Current research is usually focused on the macro effects of biochar on AD, while the systematic review about the mechanisms of biochar on microbial behavior are still lacking. This review summarizes the effects and potential mechanisms of biochar on microorganisms in AD systems, and found that biochar addition can provide habitats for microbial colonization, alleviate toxins stress, supply essential nutrients, and accelerate interspecies electron transferring. Moreover, it also improves microbial community diversity, facilitates EPS secretion, enhances functional enzyme activity, promotes functional genes expression, and inhibits the antibiotic resistance genes transformation. Future research directions including biochar targeted design, in-depth microbial mechanisms revelation, and modified model development were suggested, which could promote the widely practical application of of biochar-amended AD technology.

Design, synthesis, and STING-agonistic activity of benzo[b]thiophene-2-carboxamide derivatives

STING is an important immune-associated protein that localizes in the endoplasmic reticulum membrane. Upon being activated by its agonists, STING triggers the IRF and NF-κB pathways, which generates type I interferons and proinflammatory cytokines, and ultimately primes the innate immune responses to achieve valid antitumor efficacy. We designed and synthesized a series of benzo[b]thiophene-2-carboxamide derivatives. Through STING-agonistic activity evaluation, compounds 12d and 12e exhibited marginal human STING-activating activities. Western blot analysis demonstrated that both 12d and 12e treatment increased the phosphorylation of the downstream signaling molecules (TBK1 and IRF3) of STING. The proposed binding mode of 12d/12e and STING protein displayed that two canonical hydrogen bonds, a π-π stacking interaction, as well as a π-cation interaction formed between the agonist and the CDN-binding domain of STING protein.

Prediction of osteoporotic degradation of tibia human bone at trabecular scale

A theoretical numerical model is proposed to predict patient dependent osteoporotic bone degradation. The model parameters are identified through a particle swarm optimization algorithm and based on individual patient high resolution peripherical quantitative computer tomography (HRpQCT) scan data. The degradation model is based on cellular activity initiated by the elastic strain energy developed in the bone microstructure through patient's body weight. The macro (organ scale) and meso (trabecular scale) scale analyses are carried out and predicted bone volume fraction and microstructure evolution are compared with in-vivo experimental bone degradation for four elderly women over a period of 10 years. A significant correlation (r > 0.9) is observed between the model predictions and in-vivo experiments in all cases with an average deviation error of 1.46%. The model can easily be extended to other patients and provide good predictions for different population categories such as ethnicity, gender, age, etc.

An economic approach to energy budgets: HOW many resources should living organisms spare?

Ramsey's economic theory of saving (RTS) estimates how much of its commodities a nation should save to safeguard the well-being of future generations. Since RTS retains many attractive qualities such as simplicity, strength, breadth and generality, here we ask if it would be useful to investigate biophysical issues. Specifically, we focus on a biological topic that lends itself as a backdrop for the study of the imbalance between intake and expenditure, i.e., the evaluation of the multicellular living organisms' energetic requirements and constraints. Our problem is to find at each time the optimum distribution and the right balance of the cellular energy budget between consumption and storage: how much must a living organism spare to increase its chances of survival over long periods? To give an operational example, we discuss the ATP requirements in the central nervous system during the spontaneous and the evoked activity of the brain, showing that the experimentally detected values of energetic expenditure during neural computations match well with the estimations provided by RTS. Suggesting how to find the optimum allocation of the available energy between expenditure and saving at each time, RTS approaches to biological energy budgets may have a wide range of experimental applications, such as: a) optimization of the long-term survival chances of either immortalized cell cultures, or beneficial bacterial colonies and exogenous probiotic mixtures; b) eradication of detrimental biofilms, such as, e.g., heart valves' Streptococcus colonies; c) novel anti-stress and anti-ageing strategies.

Kinetic and structural investigations of novel inhibitors of human epithelial 15-lipoxygenase-2

Human epithelial 15-lipoxygenase-2 (h15-LOX-2, ALOX15B) is expressed in many tissues and has been implicated in atherosclerosis, cystic fibrosis and ferroptosis. However, there are few reported potent/selective inhibitors that are active ex vivo. In the current work, we report newly discovered molecules that are more potent and structurally distinct from our previous inhibitors, MLS000545091 and MLS000536924 (Jameson et al, PLoS One, 2014, 9, e104094), in that they contain a central imidazole ring, which is substituted at the 1-position with a phenyl moiety and with a benzylthio moiety at the 2-position. The initial three molecules were mixed-type, non-reductive inhibitors, with IC₅₀ values of 0.34 ± 0.05 μM for MLS000327069, 0.53 ± 0.04 μM for MLS000327186 and 0.87 ± 0.06 μM for MLS000327206 and greater than 50-fold selectivity versus h5-LOX, h12-LOX, h15-LOX-1, COX-1 and COX-2. A small set of focused analogs was synthesized to demonstrate the validity of the hits. In addition, a binding model was developed for the three imidazole inhibitors based on computational docking and a co-structure of h15-LOX-2 with MLS000536924. Hydrogen/deuterium exchange (HDX) results indicate a similar binding mode between MLS000536924 and MLS000327069, however, the latter restricts protein motion of helix-α2 more, consistent with its greater potency. Given these results, we designed, docked, and synthesized novel inhibitors of the imidazole scaffold and confirmed our binding mode hypothesis. Importantly, four of the five inhibitors mentioned above are active in an h15-LOX-2/HEK293 cell assay and thus they could be important tool compounds in gaining a better understanding of h15-LOX-2's role in human biology. As such, a suite of similar pharmacophores that target h15-LOX-2 both in vitro and ex vivo are presented in the hope of developing them as therapeutic agents.

Anti-chronic myeloid leukemia activity and quantitative structure-activity relationship of novel thiazole aminobenzamide derivatives

The anti-chronic myeloid leukemia activity of thiazole aminobenzamide derivatives in vitro was tested by a methanethiosulfonate (MTS)-based viability assay method, and the result showed that some compounds exhibited good inhibitory activities against human chronic myeloid leukemia cell line K562, imatinib-resistant strain K562/R and T135I mutant cell line BaF₃-ABL-BCR-T315I. Comparative molecular field analysis (CoMFA) and comparative molecular similarity index analysis (CoMSIA) methods were used to analyze the relationship between the structure of thiazole aminobenzamide derivatives and the inhibition of K562/R cell activity. In CoMFA, Q² was 0.899 and R² was 0.963; in CoMSIA, Q² and R² were 0.840 and 0.903, respectively. These data indicated that the selected test set showed suitable external predictive ability. Combined with the contour map results, we further analyzed the three-dimensional quantitative structure (3D-QSAR) model. The results demonstrated that in the backbone of the thiazole aminobenzamide derivative, the substitution of a small group at R¹ position, or the introduction of a hydrophilic group at R² position, or the introduction of a large-volume amino acid at R³ position may be beneficial to improve the anti-CML activity of the compound.

Cytotoxicity and biocompatibility of high mol% yttria containing zirconia

Objectives

Yttria-stabilized tetragonal phase zirconia has been used as a dental restorative material for over a decade. While it is still the strongest and toughest ceramic, its translucency remains as a significant drawback. To overcome this, stabilizing the translucency zirconia to a significant cubic crystalline phase by increasing the yttria content to more than 8 mol% (8YTZP). However, the biocompatibility of a high amount of yttria is still an important topic that needs to be investigated.

Materials and Methods

Commercially available 8YTZP plates were used. To enhance cell adhesion, proliferation, and differentiation, the surface of the 8YTZP is sequentially polished with a SiC-coated abrasive paper and surface coating with type I collagen. Fibroblast-like cells L929 used for cell adherence and cell proliferation analysis, and mouse bone marrow-derived mesenchymal stem cells (BMSC) used for cell differentiation analysis.

Results

The results revealed that all samples, regardless of the surface treatment, are hydrophilic and showed a strong affinity for water. Even the cell culture results indicate that simple surface polishing and coating can affect cellular behavior by enhancing cell adhesion and proliferation. Both L929 cells and BMSC were nicely adhered to and proliferated in all conditions.

Conclusions

The results demonstrate the biocompatibility of the cubic phase zirconia with 8 mol% yttria and suggest that yttria with a higher zirconia content are not toxic to the cells, support a strong adhesion of cells on their surfaces, and promote cell proliferation and differentiation. All these confirm its potential use in tissue engineering.

Analytical Method for Diacylglycerol Kinase ζ Activity in Cells Using Protein Myristoylation and Liquid Chromatography-Tandem Mass Spectrometry

Specific inhibitors of diacylglycerol kinase (DGK) ζ can be promising anticancer medications via the activation of cancer immunity. Although the detection of cellular activities of target enzymes is essential for drug screening in addition to in vitro assays, it is difficult to detect the activity of DGKζ in cells. In the present study, we generated AcGFP-DGKζ cDNA with a consensus N-myristoylation sequence at the 5' end (Myr-AcGFP-DGKζ) to target DGKζ to membranes. Using liquid chromatography (LC)-tandem mass spectrometry (MS/MS) (LC-MS/MS), we showed that Myr-AcGFP-DGKζ, but not AcGFP-DGKζ without the myristoylation sequence, substantially augmented the levels of several phosphatidic acid (PtdOH) species. In contrast to Myr-AcGFP-DGKζ, its inactive mutant did not exhibit an increase in PtdOH production, indicating that the increase in PtdOH production was DGK activity-dependent. This method will be useful in chemical compound selection for the development of drugs targeting DGKζ and can be applicable to various soluble (nonmembrane bound) lipid-metabolizing enzymes, including other DGK isozymes.

Preparation of electrospun nanofibers with desired microstructures using a programmed three-dimensional (3D) nanofiber collector

The traditional electrospinning process produces dense two-dimensional (2D) nanofiber (NF) sheets that limit cell infiltration and proliferation. Our previous study demonstrated that 3D NF sheets could be formed on an NF collector surface mounted with multiple movable needles through the corona discharge. In this study, we developed a programmed electrospun 3D NF collector. It can precisely control the moving speed of NF collector during electrospinning; thereby fabricating 3D NFs with desired microstructures (pore size, pore volume, and interconnectivity). Four types of polycaprolactone (PCL) 3D NF matrices with different microstructures can be obtained concurrently on the NF collector surface, which are set by different forward moving speed of the NF collector device: NF-zero (no move, as control), NF-low (0.085 mm/min), NF-mid (0.158 mm/min) and NF-high (0.232 mm/min). A linear increase of the NF sheet thickness (from 0.21 mm to 0.91 mm) was recorded with accelerating collector movement. Quantitative analysis using scanning electron microscopy (SEM), micro-computed tomography (μ-CT), and confocal laser scanning microscopy (CLSM) showed a monotonic increase of pore size and porosity with the increase of collector moving speeds. The collector movement also impacted the crystallinity and mechanical properties of the NFs. When prepared at high collector speed, the NFs showed improved proliferation and differentiation (p < .05) of pre-osteoblastic MC3T3 cells compared to the NFs from the static collector. A programmed NF collector device allows for the reproducible, precise and continuous fabrication of 3D NFs with tailorable geometry and microstructures. This simple, controllable, one-step process could promote the clinical translation of electrospun NFs in tissue engineering and regenerative medicine.

Design, synthesis and biological evaluation of uncharged catechol derivatives as selective inhibitors of PTP1B

Protein tyrosine phosphatases 1B (PTP1B) is a promising and validated therapeutic target to effectively treat T2DM and obesity. However, the development of charged PTP1B inhibitors was restricted due to their low cell permeability and poor bioavailability. Based on active natural products, two series of uncharged catechol derivatives were identified as PTP1B inhibitors by targeting a secondary aryl phosphate-binding site as well as the catalytic site. The most potent inhibitor 22 showed an IC₅₀ of 0.487 μM against PTP1B and strong selectivity (27-fold) over TCPTP. Kinetic studies were also performed that 22 act as a competitive PTP1B inhibitor. The treatment of C2C12 myotubes with 22 markedly increased the phosphorylation levels of IRβ, Akt and IRS1 phosphorylation. The similarity of its action profiling with that produced by insulin suggested its potential as a new non-insulin-dependent drug candidate.

Exposure of Daphnia magna to trichloroethylene (TCE) and vinyl chloride (VC): evaluation of gene transcription, cellular activity, and life-history parameters

Trichloroethylene (TCE) is a ubiquitous contaminant classified as a human carcinogen. Vinyl chloride (VC) is primarily used to manufacture polyvinyl chloride and can also be a degradation product of TCE. Very few data exist on the toxicity of TCE and VC in aquatic organisms particularly at environmentally relevant concentrations. The aim of this study was to evaluate the sub-lethal effects (10 day exposure; 0.1; 1; 10 µg/L) of TCE and VC in Daphnia magna at the gene, cellular, and life-history levels. Results indicated impacts of VC on the regulation of genes related to glutathione-S-transferase (GST), juvenile hormone esterase (JHE), and the vitelline outer layer membrane protein (VMO1). On the cellular level, exposure to 0.1, 1, and 10 µg/L of VC significantly increased the activity of JHE in D. magna and TCE increased the activity of chitinase (at 1 and 10 µg/L). Results for life-history parameters indicated a possible tendency of TCE to affect the number of molts at the individual level in D. magna (p=0.051). Measurement of VG-like proteins using the alkali-labile phosphates (ALP) assay did not show differences between TCE treated organisms and controls. However, semi-quantitative measurement using gradient gel electrophoresis (213-218 kDa) indicated significant decrease in VG-like protein levels following exposure to TCE at all three concentrations. Overall, results indicate effects of TCE and VC on genes and proteins related to metabolism, reproduction, and growth in D. magna.

Design, synthesis and evaluation of 7-azaindazolyl-indolyl-maleimides as glycogen synthase kinase-3β (GSK-3β) inhibitors

A series of 7-azaindazolyl-indolyl-maleimides were designed, synthesized and evaluated for their GSK-3β inhibitory activity. Most compounds exhibited potent activity against GSK-3β. Among them, compounds 17a, 17b, 17g, 17i, 29a and 30 significantly reduced Aβ-induced Tau hyperphosphorylation, showin;g the inhibition of GSK-3β at the cell level. Preliminary structure-activity relationships were discussed based on the experimental data obtained.