Synthesis,Biological Evaluation,and Molecular Modeling Studies of New 1,3,4-Thiadiazole Derivatives as Potent Antimicrobial Agents

In this work, the synthesis, characterization, and biological activities of a new series of 1,3,4-thiadiazole derivatives were investigated. The structures of final compounds were identified using ¹H-NMR, ¹³C-NMR, elemental analysis, and HRMS. All the new synthesized compounds were then screened for their antimicrobial activity against four types of pathogenic bacteria and one fungal strain, by application of the MIC assays, using Ampicilin, Gentamycin, Vancomycin, and Fluconazole as standards. Among the compounds, the MIC values of 4 and 8 μg/mL of the compounds 3f and 3g , respectively, are remarkable and indicate that these compounds are good candidates for antifungal activity. The docking experiments were used to identify the binding forms of produced ligands with sterol 14-demethylase to acquire insight into relevant proteins. The MD performed about 100 ns simulations to validate selected compounds’ theoretical studies. Finally, using density functional theory (DFT) to predict reactivity, the chemical characteristics and quantum factors of synthesized compounds were computed. These results were then correlated with the experimental data. Furthermore, computational estimation was performed to predict the ADME properties of the most active compound 3f .     

Design,Synthesis, and Biological Evaluation of Novel Indanone Derivatives as Cholinesterase Inhibitors for Potential Use in Alzheimer's Disease

Indanone derivatives containing meta/para-substituted aminopropoxy benzyl/benzylidene moieties were designed based on the structures of donepezil and ebselen analogs as the cholinesterase inhibitors. The designed compounds were synthesized and their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities were measured. Inhibitory potencies (IC₅₀ values) for the synthesized compounds ranged from 0.12 to 11.92 μM and 0.04 to 24.36 μM against AChE and BChE, respectively. Compound 5 c showed the highest AChE inhibitory potency with IC₅₀ value of 0.12 μM, whereas the highest BChE inhibition was achieved by structure 7 b (IC₅₀=0.04 μM). Structure-activity relationship (SAR) analysis revealed that there is no significant difference between meta and para-substituted derivatives in AChE and BChE inhibition. However, the most potent AChE inhibitor 5 c belongs to meta-substituted compounds, while the most active BChE inhibitor is para-substituted derivative 7 b . The order of enzyme inhibition potency based on the substituted amine group is dimethyl amine>piperidine>morpholine. Compounds containing C=C linkage are more potent AChE inhibitors than the corresponding saturated structures. Molecular docking studies indicated that 5 c interacts with AChE in a very similar way to that observed experimentally for donepezil. The introduced indanone-aminopropoxy benzylidenes could be used in drug-discovery against Alzheimer's disease.     

Expression of a human cytomegalovirus gp58 antigenic domain fused to the hepatitis B virus nucleocapsid protein

Abstract Hepatitis B virus core antigen (HBcAg) has been used as a carrier for expression and presentation of a variety of heterologous viral epitopes in particulate form. The aim of this study was to produce hybrid antigens comprising HBcAg and an immunogenic epitope of human cytomegalovirus (HCMV). A direct comparison was made of amino and carboxyl terminal fusions in order to investigate the influence of position of the foreign epitope on hybrid core particle formation, antigenicity and immunogenicity. HCMV DNA encoding a neutralising epitope of the surface glycoprotein gp58 was either inserted at the amino terminus or fused to the truncated carboxyl terminus of HBcAg and expressed in Escherichia coli . The carboxyl terminal fusion (HBc_3–144-HCMV) was expressed at high levels and assembled into core like particles resembling native HBcAg. Protein with a similar fusion at the amino terminus (HCMV-HBc_1–183) could not be purified or characterised immunologically, although it formed core like particles. HBc_3–144-HCMV displayed HBc antigenicity but HCMV antigenicity could not be detected by radioimmunoassay or western blotting using anti-HCMV monoclonal antibody 7–17 or an anti-HCMV human polyclonal antiserum. Following immunisation of rabbits with HBc_3–144-HCMV, a high titre of anti-HBc specific antibody was produced along with lower titres of HCMV/gp58 specific antibody.     

Strain design optimization using reinforcement learning

Engineered microbial cells present a sustainable alternative to fossil-based synthesis of chemicals and fuels. Cellular synthesis routes are readily assembled and introduced into microbial strains using state-of-the-art synthetic biology tools. However, the optimization of the strains required to reach industrially feasible production levels is far less efficient. It typically relies on trial-and-error leading into high uncertainty in total duration and cost. New techniques that can cope with the complexity and limited mechanistic knowledge of the cellular regulation are called for guiding the strain optimization.In this paper, we put forward a multi-agent reinforcement learning (MARL) approach that learns from experiments to tune the metabolic enzyme levels so that the production is improved. Our method is model-free and does not assume prior knowledge of the microbe’s metabolic network or its regulation. The multi-agent approach is well-suited to make use of parallel experiments such as multi-well plates commonly used for screening microbial strains.We demonstrate the method’s capabilities using the genome-scale kinetic model of Escherichia coli, k-ecoli457, as a surrogate for an in vivo cell behaviour in cultivation experiments. We investigate the method’s performance relevant for practical applicability in strain engineering i.e. the speed of convergence towards the optimum response, noise tolerance, and the statistical stability of the solutions found. We further evaluate the proposed MARL approach in improving L-tryptophan production by yeast Saccharomyces cerevisiae, using publicly available experimental data on the performance of a combinatorial strain library.Overall, our results show that multi-agent reinforcement learning is a promising approach for guiding the strain optimization beyond mechanistic knowledge, with the goal of faster and more reliably obtaining industrially attractive production levels.     

Comparative Evaluation of Cardiac Markers in Differentiated Cells from Menstrual Blood and Bone Marrow-Derived Stem Cells In Vitro

In recent years, menstrual blood-derived stem cells (MenSCs) have been introduced as easily accessible and refreshing stem cell source without ethical considerations in the field of regenerative medicine. The aim of this study was to investigate in vitro cardiac differentiation capacity of MenSCs compared to bone marrow-derived stem cells (BMSCs) under two protocols using 5-aza-2′-deoxycytidine (5-aza) and basic fibroblast growth factor (bFGF). Our data revealed that differentiated MenSCs and BMSCs acquired some features of cardiomyocytes; however, degree of differentiation was dependent on the protocol. In a similar manner with BMSCs, differentiated MenSCs showed upper levels of mRNA/protein of late-stage cardiac markers under 5-aza stimulation and continuous treatment with bFGF (protocol 2) compared to those induced by 5-aza alone (protocol 1) evidencing the key role of bFGF in cardiac development of stem cells. Compared to corresponding undifferentiated cells differentiated MenSCs under protocol 2 showed remarkable expression of connexin-43 and TNNT2 at both gene and protein levels, whereas developed BMSCs under the same condition only expressed connextin-43 at the higher level. Superiority of protocol 2 over protocol 1 was confirmed by assessment of LDH and cTnI production by differentiated cells. Based on the accumulative data, our study provided convincing evidence that MenSCs have relatively higher capability to be differentiated toward cardiomyocyte compared with BMSCs. Furthermore, usage of bFGF and 5-aza to induce in vitro cardiac differentiation of MenSCs is highly recommended.     

Salusin-α attenuates inflammatory responses in vascular endothelial cells

Atherosclerosis accounts for numerous cardiovascular diseases, and cytokines have a critical role in acceleration or suppression of disease. Salusin-α presents a new class of bioactive peptides that can have anti-atherogenic properties. Therefore, the effects of salusin-α on the expression of some pro- and anti-inflammatory cytokines and on TNF-α-induced inflammatory responses in human umbilical vein endothelial cells (HUVECs) were examined. The involvement of the NF-κB pathway in effects of salusin-α in HUVECs was checked using Bay 11-7082 as an NF-κB inhibitor. The mRNA expression of pro-inflammatory cytokines including IL-6, IL-8, and IL-18 and anti-inflammatory cytokine IL-1Ra was assessed by real-time PCR. The protein levels of cytokines were measured by the ELISA method. Salusin-α suppressed both mRNA and protein expression of pro-inflammatory cytokines and induced mRNA and protein expression of IL-1Ra in HUVECs. Salusin-α suppressed TNF-α-induced inflammatory responses in HUVECs. The down-regulatory or up-regulatory effects of salusin-α on expression of cytokines could not be influenced by Bay 11-7082 pretreatment. Our findings indicate anti-inflammatory effects of salusin-α and suggest a novel peptide-based therapeutic strategy for atherosclerosis.     

Is miR-144 an effective inhibitor of PTEN mRNA: a controversy in breast cancer

Breast cancer is the first common cancer among women worldwide. One of the major signaling pathways playing a role in the onset and progression of this disease is PI3K/Akt/mTOR, which can be inhibited by PTEN. miRNAs are small non-coding molecules that regulate the expression of their targets by inhibition or suppression, and thus, their dysregulated expression results in the development of cancer. Using various software applications predicting miRNAs and evaluating GEO microarray data, miR-144 was selected as an inhibitor of PTEN. The expression of miR-144 and PTEN was evaluated in 18 triple negative breast cancer (TNBC) clinical samples and cell lines including 4T1, MDA-MB-231, MDA-MB-468, SK-BR-3, and MCF-7 in comparison with normal cells. PTEN and miR-144 expression analysis revealed their elevated expression in MCF-7 cells. MDA-MB-468, SK-BR-3, and MDA-MB-231 cells showed decreased levels of PTEN and increased levels of miR-144. In contrast, 4T1 cells had an increased expression of PTEN and decreased expression of miR-144. In clinical samples, miR-144 was up-regulated in 22% of the cases and PTEN was down-regulated in 78% of the cases. The results showed that the expression of PTEN and miR-144 was inversely correlated in metastatic breast cancer cell lines. However, in TNBC clinical samples, there was no correlation between the expression of miR-144 and PTEN. Literature shows that there are other influencing factors affecting the expression of miRNAs. Therefore, care should be taken in interpreting the results of gene expression studies and its relation with cancer diagnosis/prognosis.     

Reversal of coenzyme specificity of 2,3‐butanediol dehydrogenase from Saccharomyces cerevisae and in vivo functional analysis

Saccharomyces cerevisiae NAD(H)‐dependent 2,3‐butanediol dehydrogenase (Bdh1), a medium chain dehydrogenase/reductase is the main enzyme catalyzing the reduction of acetoin to 2,3‐butanediol. In this work we focused on altering the coenzyme specificity of Bdh1 from NAD(H) to NADP(H). Based on homology studies and the crystal structure of the NADP(H)‐dependent yeast alcohol dehydrogenase Adh6, three adjacent residues (Glu²²¹, Ile²²², and Ala²²³) were predicted to be involved in the coenzyme specificity of Bdh1 and were altered by site‐directed mutagenesis. Coenzyme reversal of Bdh1 was obtained with double Glu221Ser/Ile222Arg and triple Glu221Ser/Ile222Arg/Ala223Ser mutants. The performance of the triple mutant for NADPH was close to that of native Bdh1 for NADH. The three engineered mutants were able to restore the growth of a phosphoglucose isomerase deficient strain (pgi), which cannot grow on glucose unless an alternative NADPH oxidizing system is provided, thus demonstrating their in vivo functionality. These mutants are interesting tools to reduce the excess of acetoin produced by engineered brewing or wine yeasts overproducing glycerol. In addition, they represent promising tools for the manipulation of the NADP(H) metabolism and for the development of a powerful catalyst in biotransformations requiring NADPH regeneration. Biotechnol. Bioeng. 2009; 104: 381–389 © 2009 Wiley Periodicals, Inc.