- Copper complexes containing thiosemicarbazones derived from 6-nitropiperonal: Antimicrobial and biophysical properties. [Journal Article]
- SASpectrochim Acta A Mol Biomol Spectrosc 2017 Apr 20; 183:158-171
- A series of four thiosemicarbazones from 6-nitropiperonal along with the corresponding copper complexes were synthesized. The biophysical characteristics of the complexes were investigated by the bin...
A series of four thiosemicarbazones from 6-nitropiperonal along with the corresponding copper complexes were synthesized. The biophysical characteristics of the complexes were investigated by the binding to DNA and human serum albumin. The binding to DNA is moderate; the binding constants run from (0.49-7.50)×10(4)M(-1). In relation to HSA, the complexes interact strongly with binding constants on the order of 10(5)M(-1). The complexes also display antioxidant behavior as determined by the ability to scavenge diphenylpicrylhydrazyl (dpph) and nitric oxide radicals. The antimicrobial profiles of the compounds, tested against a panel of microbes including five of the ESKAPE pathogens (Staphylococcus aureus, MRSA, Escherichia coli, Klebsiella pneumoniae, MDR, Acinetobacter baumannii, Pseudomonas aeruginosa) and two yeasts (Candida albicans and Cryptococcus neoformans var. grubii), are also described. The compounds contain a core moiety that is similar to oxolinic acid, a quinolone antibiotic that targets DNA gyrase and topoisomerase (IV). The binding interaction between the complexes and these important antibacterial targets were studied by computational methods, chiefly docking studies. The calculated dissociation constants for the interaction with DNA gyrase B (from Staphylococcus aureus) range from 4.32 to 24.65μM; the binding was much stronger to topoisomerase IV, with dissociation constants ranging from 0.37 to 1.27μM.
- Construction of three-dimensional vascularized functional human liver tissue using a layer-by-layer cell coating technique. [Journal Article]
- BBiomaterials 2017 Feb 28; 133:263-274
- The creation of artificial liver tissue is an active area of research due to the shortage of donors for liver transplantation. Here we investigated whether a simple and efficient cell coating techniq...
The creation of artificial liver tissue is an active area of research due to the shortage of donors for liver transplantation. Here we investigated whether a simple and efficient cell coating technique developed in our laboratory could be used to generate functional vascularized liver tissue. This technique creates three-dimensional tissue by loading cells sterically onto other cells that have been coated with layer-by-layer (LbL) nanofilms of fibronectin and gelatin, two extracellular matrix proteins. We used this technique to construct homogenous, dense, well-vascularized liver tissue from cryopreserved human primary hepatocytes, human umbilical vein endothelial cells, and normal human dermal fibroblasts. Using LbL cell coating technique resulted in higher cellular function in terms of human albumin production (P < 0.01) and cytochrome P450 activity (P < 0.01) in vitro. Furthermore, after being transplanted subcutaneously into NOD/SCID mice, the vascularized liver tissue showed greater albumin production in the early stage than non-vascularized tissue or a hepatocyte suspension (P < 0.01). Histological examination demonstrated that compare to non-vascularized tissue, there were many less-morphologically changed and intact hepatocytes in the vascularized tissue. This cell coating technique would be applicable to the generation of vascularized functional liver tissue for regenerative medicine in the future.
- Advanced glycation end products‑induced mitochondrial energy metabolism dysfunction alters proliferation of human umbilical vein endothelial cells. [Journal Article]
- MMMol Med Rep 2017 Mar 10
- Advanced glycation end products (AGEs) restrain the proliferation of endothelial cells, which is an important determinant of diabetic vasculopathy. Mitochondrial biogenesis serves an essential role i...
Advanced glycation end products (AGEs) restrain the proliferation of endothelial cells, which is an important determinant of diabetic vasculopathy. Mitochondrial biogenesis serves an essential role in cellular adaptation and repair. The current study aimed to investigate alterations in mitochondrial energy metabolism in human umbilical vein endothelial cells (HUVECs) and the latent mechanism regulated by AGEs. The proliferation of cultured HUVECs stimulated with AGEs was detected using an MTT assay and a real‑time cell analyzer (RTCA). Mitochondrial energy metabolism was measured using a Seahorse metabolic flux analyzer. Mitochondrial membrane potential was detected under fluorescence microscopy following staining with tetraethylrhodamine and MitoTracker Red. Respiratory chain complexes I‑V were detected using western blotting. MTT and RTCA assays demonstrated that AGEs treatment significantly inhibited the viability and proliferation of HUVECs when compared with bovine serum albumin treatment. Results from the Seahorse metabolic flux analyzer indicated that mitochondrial aerobic respiration and glycolysis declined following AGEs treatment. In addition, mitochondrial membrane potential and the expression of mitochondrial respiration chain complexes I/II/III/IV/V notably decreased in the presence of AGEs. In conclusion, the results of the present study indicated that AGEs exhibited an inhibitory effect on the proliferation in HUVECs potentially by mediating the dysfunction of mitochondrial energy metabolism and glycolysis. This may provide a new consideration for therapeutic methods in diabetic vascular complications.
- An EThcD-Based Method for Discrimination of Leucine and Isoleucine Residues in Tryptic Peptides. [Journal Article]
- JAJ Am Soc Mass Spectrom 2017 Apr 26
- An EThcD-based approach for the reliable discrimination of isomeric leucine and isoleucine residues in peptide de novo sequencing procedure has been proposed. A multistage fragmentation of peptide io...
An EThcD-based approach for the reliable discrimination of isomeric leucine and isoleucine residues in peptide de novo sequencing procedure has been proposed. A multistage fragmentation of peptide ions was performed with Orbitrap Elite mass spectrometer in electrospray ionization mode. At the first stage, z-ions were produced by ETD or ETcaD fragmentation of doubly or triply charged peptide precursor ions. These primary ions were further fragmented by HCD with broad-band ion isolation, and the resulting w-ions showed different mass for leucine and isoleucine residues. The procedure did not require manual isolation of specific z-ions prior to HCD stage. Forty-three tryptic peptides (3 to 27 residues) obtained by trypsinolysis of human serum albumin (HSA) and gp188 protein were analyzed. To demonstrate a proper solution for radical site migration problem, three non-tryptic peptides were also analyzed. A total of 93 leucine and isoleucine residues were considered and 83 of them were correctly identified. The developed approach can be a reasonable substitution for additional Edman degradation procedure, which is still used in peptide sequencing for leucine and isoleucine discrimination. Graphical Abstract ᅟ.
- Absence of Decline of Kidney Function in Human Immunodeficiency Virus-Infected Patients Under Routine Clinical Management. [Journal Article]
- NNephron 2017 Apr 26; 136(3)
- CONCLUSIONS: Decline in kidney function is limited under routine clinical management with monitoring of renal function and interventions including decision to continue or discontinue TDF.
- Economic evaluation of human albumin use in patients with nephrotic syndrome in four Brazilian public hospitals: pharmacoeconomic study. [Journal Article]
- SPSao Paulo Med J 2017 Apr 20; :0
- CONCLUSIONS: The economic analyses of this study demonstrated that there were greater cost benefits for patients whose treatment followed the guidelines.
- Absorption, distribution, metabolism and excretion of the oral prostaglandin D2 receptor 2 (DP2) antagonist fevipiprant (QAW039) in healthy volunteers and in vitro. [Journal Article]
- DMDrug Metab Dispos 2017 Apr 25
- Fevipiprant is a novel oral prostaglandin D2 receptor 2 (DP2; also known as CRTh2) antagonist, which is currently in development for the treatment of severe asthma and atopic dermatitis. We investiga...
Fevipiprant is a novel oral prostaglandin D2 receptor 2 (DP2; also known as CRTh2) antagonist, which is currently in development for the treatment of severe asthma and atopic dermatitis. We investigated the absorption, distribution, metabolism, and excretion properties of fevipiprant in healthy subjects after a single 200 mg oral dose of [(14)C]-radiolabeled fevipiprant. Fevipiprant and metabolites were analyzed by liquid chromatography coupled to tandem mass spectrometry and radioactivity measurements, and mechanistic in vitro studies were performed to investigate clearance pathways and covalent plasma protein binding. Biotransformation of fevipiprant involved predominantly an inactive acyl glucuronide (AG) metabolite, which was detected in plasma and excreta, representing 28% of excreted drug-related material. The AG metabolite was found to covalently bind to human plasma proteins, likely albumin; however, in vitro covalent binding to liver protein was negligible. Excretion was predominantly as unchanged fevipiprant in urine and feces, indicating clearance by renal and possibly biliary excretion. Fevipiprant was found to be a substrate of transporters organic anion transporter 3 (OAT3; renal uptake), multi-drug resistance gene 1 (MDR1; possible biliary excretion), and organic anion-transporting polypeptide 1B3 (OATP1B3; hepatic uptake). Elimination of fevipiprant occurs via glucuronidation by several uridine 5'-diphospho glucuronosyltransferase (UGT) enzymes, as well as direct excretion. These parallel elimination pathways result in a low risk of major drug-drug interactions or pharmacogenetic/ethnic variability for this compound.
- Protein-Nanocellulose Interactions in Paper Filters for Advanced Separation Applications. [Journal Article]
- LLangmuir 2017 Apr 26
- Protein-based pharmaceutics are widely explored for healthcare applications, and six out of ten best selling drugs today are biologicals. The goal of this work was to evaluate the protein nanocellulo...
Protein-based pharmaceutics are widely explored for healthcare applications, and six out of ten best selling drugs today are biologicals. The goal of this work was to evaluate the protein nanocellulose interactions in paper filter for advanced separation applications such as virus removal filtration and bioprocessing. The protein recovery was measured for bovine serum albumin (BSA), γ-Globulin and Lysozyme using biuret total protein reagent and polyacrylamide gel electrophoresis (SDS-PAGE), and the throughput was characterized in terms of flux values from fixed volume filtrations at various protein concentrations and under worst-case experimental conditions. The affinity of cellulose to bind various proteins, such as BSA, lysozyme, γ-globulin, and human IgG, was quantified using a quartz crystal microbalance (QCMB) by developing a new method of fixing the cellulose fibers to the electrode surface without cellulose dissolution-precipitation. It was shown that the mille-feuille filter exhibits high protein recovery, i.e. ~ 99% for both BSA and Lysozyme. However γ-globulin does not pass through the membrane, due to its the large size. It was concluded that the mille-feuille paper filter does not cause protein aggregation. The SDS-PAGE data show no change in the amount of dimers and trimers before and after filtration. QCMB analysis supported the low affinity between the nanocellulose surface and proteins. The results are highly valuable for future development of non-woven nanocellulose-based filters for advanced separation applications such as upstream and downstream protein processing.
- Molecular interaction of 2,4-diacetylphloroglucinol (DAPG) with human serum albumin (HSA): The spectroscopic, calorimetric and computational investigation. [Journal Article]
- SASpectrochim Acta A Mol Biomol Spectrosc 2017 Apr 18; 183:90-102
- Drug molecule interaction with human serum albumin (HSA) affects the distribution and elimination of the drug. The compound, 2,4-diacetylphloroglucinol (DAPG) has been known for its antimicrobial, an...
Drug molecule interaction with human serum albumin (HSA) affects the distribution and elimination of the drug. The compound, 2,4-diacetylphloroglucinol (DAPG) has been known for its antimicrobial, antiviral, antihelminthic and anticancer properties. However, its interaction with HSA is not yet reported. In this study, the interaction between HSA and DAPG was investigated through steady-state fluorescence, time-resolved fluorescence (TRF), circular dichroism (CD), Fourier transform infrared (FT-IR) spectroscopy, isothermal titration calorimetry (ITC), molecular docking and molecular dynamics simulation (MDS). Fluorescence spectroscopy results showed the strong quenching of intrinsic fluorescence of HSA due to interaction with DAPG, through dynamic quenching mechanism. The compound bound to HSA with reversible and moderate affinity which explained its easy diffusion from circulatory system to target tissue. The thermodynamic parameters from fluorescence spectroscopic data clearly revealed the contribution of hydrophobic forces but, the role of hydrogen bonds was not negligible according to the ITC studies. The interaction was exothermic and spontaneous in nature. Binding with DAPG reduced the helical content of protein suggesting the unfolding of HSA. Site marker fluorescence experiments revealed the change in binding constant of DAPG in the presence of site I (warfarin) but not site II marker (ibuprofen) which confirmed that the DAPG bound to site I. ITC experiments also supported this as site I marker could not bind to HSA-DAPG complex while site II marker was accommodated in the complex. In silico studies further showed the lowest binding affinity and more stability of DAPG in site I than in site II. Thus the data presented in this study confirms the binding of DAPG to the site I of HSA which may help in further understanding of pharmacokinetic properties of DAPG.
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- Glycated albumin is stable in plasma when exposed to common laboratory conditions and comparable when drawn from venous or capillary sites. [Journal Article]
- JCJ Clin Lab Anal 2017 Apr 25
- CONCLUSIONS: Glycated albumin in plasma appears relatively stable when exposed to common laboratory conditions, reducing a potential confounder to its use as a marker of blood glucose control. The glycated albumin (%) in samples from capillary and venous sites was comparable, suggesting the potential of rapid or portable assessment devices that require a finger prick.