- Use of Serum Transthyretin as a Prognostic Indicator and Predictor of Outcome in Cardiac Amyloid Disease Associated With Wild-Type Transthyretin. [Journal Article]
- CHCirc Heart Fail 2018; 11(2):e004000
- CONCLUSIONS: In this series of biopsy-proven ATTRwt, lower baseline serum TTR concentration was associated with shorter survival as an independent predictor of outcome. Longitudinal analysis demonstrated that decreasing TTR corresponded to worsening cardiac function. These data suggest that TTR may be a useful prognostic marker and predictor of outcome in ATTRwt.
- Amyloid deposition in a mouse model humanized at the transthyretin and retinol-binding protein 4 loci. [Journal Article]
- LILab Invest 2018 Jan 12
- Familial amyloidotic polyneuropathy is an autosomal dominant disorder caused by a point mutation in the transthyretin (TTR) gene. The process of TTR amyloidogenesis begins with rate-limiting dissocia...
Familial amyloidotic polyneuropathy is an autosomal dominant disorder caused by a point mutation in the transthyretin (TTR) gene. The process of TTR amyloidogenesis begins with rate-limiting dissociation of the TTR tetramer. Thus, the TTR stabilizers, such as Tafamidis and Diflunisal, are now in clinical trials. Mouse models will be useful to testing the efficacy of these drugs. Although several mouse models have been generated, they all express mouse Rbp4. Thus, human TTR associates with mouse RBP4, resulting in different kinetic and thermodynamic stability profiles of TTR tetramers. To overcome this problem, we previously produced humanized mouse strains at both the TTR and Rbp4 loci (TtrhTTRVal30, TtrhTTRMet30, and Rbp4hRBP4). By mating these mice, we produced double-humanized mouse strains, TtrhTTRVal30/hTTRVal30:Rbp4hRBP4/hRBP4and TtrhTTRVal30/Met30:Rbp4hRBP4/hRBP4. We used conventional transgenic mouse strains on a wild-type (Ttr+/+:Tg[6.0hTTRMet30]) or knockout Ttr background (Ttr-/-:Tg[6.0hTTRMet30]) as reference strains. The double-humanized mouse showed 1/25 of serum hTTR and 1/40 of serum hRBP4 levels. However, amyloid deposition was more pronounced in TtrhTTRVal30/Met30:Rbp4hRBP4/hRBP4than in conventional transgenic mouse strains. In addition, a similar amount of amyloid deposition was also observed in TtrhTTRVal30/ hTTRVal30:Rbp4hRBP4/ hRBP4mice that carried the wild-type human TTR gene. Furthermore, amyloid deposition was first observed in the sciatic nerve without any additional genetic change. In all strains, anti-TTR antibody-positive deposits were found in earlier age and at higher percentage than amyloid fibril deposition. In double-humanized mice, gel filtration analysis of serum revealed that most hTTR was free of hRBP4, suggesting importance of free TTR for amyloid deposition.
- Incidence of diabetes mellitus and factors associated with its development in HIV-positive patients over the age of 50. [Journal Article]
- BOBMJ Open Diabetes Res Care 2017; 5(1):e000457
- CONCLUSIONS: Among PLWH aged ≥50 years, the incidence of DM was 1.39 times higher than men in the general Canadian population of similar age. ART initiated in the early years of the epidemic and exposure to older ART appeared to be the main drivers of the development of DM.
- Supramolecular nano-engineered lipidic carriers based on diflunisal-phospholipid complex for transdermal delivery: QbD based optimization, characterization and preclinical investigations for management of rheumatoid arthritis. [Journal Article]
- IJInt J Pharm 2017 Nov 25; 533(1):206-224
- Diflunisal (DIF) is used for treatment of rheumatoid arthritis, osteoarthritis etc. DIF-phospholipid complex (DIF-PL complex) was prepared by solvent-evaporation method and characterized by molecular...
Diflunisal (DIF) is used for treatment of rheumatoid arthritis, osteoarthritis etc. DIF-phospholipid complex (DIF-PL complex) was prepared by solvent-evaporation method and characterized by molecular docking studies, SEM, FTIR, DSC, PXRD studies. Further, the DIF-PL complex was incorporated into supramolecular nano-engineered lipidic carriers (SNLCs) for transdermal delivery. The optimization exercise was done using Face centered cubic design (FCCD) after screening of variables by L8 Taguchi orthogonal array design. The optimized SNLC formulation depicted average particle size (188.1nm), degree of entrapment (86.77±3.33%), permeation flux (5.47±0.48μg/cm2/h) and skin retention (17.72±0.68μg/cm2). The dermatokinetic studies revealed the higher concentration of DIF in dermis. The Confocal laser scanning microscopy (CSLM) studies revealed penetration of SNLCs into the deeper layers of skin. The results of mice ear edema depicted significant inhibition of ear edema (76.37±12.52%; p<0.05). In CFA induced rheumatoid arthritis model, the inhibition of paw edema was significantly higher (73.85±14.5%). The levels of TNF-α were reduced in synovial fluid (146.74±1.69pg/mL) and serum (132.43±2.70pg/mL). Furthermore, the licking and biting time was reduced in formalin induced hyperalgesia model. Hence, it can be concluded that dual formulation strategy based SNLCs were promising in treatment of pain and inflammation associated with rheumatoid arthritis.
- Diflunisal inhibits prestin by chloride-dependent mechanism. [Journal Article]
- PlosPLoS One 2017; 12(8):e0183046
- The motor protein prestin is a member of the SLC26 family of anion antiporters and is essential to the electromotility of cochlear outer hair cells and for hearing. The only direct inhibitor of elect...
The motor protein prestin is a member of the SLC26 family of anion antiporters and is essential to the electromotility of cochlear outer hair cells and for hearing. The only direct inhibitor of electromotility and the associated charge transfer is salicylate, possibly through direct interaction with an anion-binding site on prestin. In a screen to identify other inhibitors of prestin activity, we explored the effect of the non-steroid anti-inflammatory drug diflunisal, which is a derivative of salicylate. We recorded prestin activity by whole-cell patch clamping HEK cells transiently expressing prestin and mouse outer hair cells. We monitored the impact of diflunisal on the prestin-dependent non-linear capacitance and electromotility. We found that diflunisal triggers two prestin-associated effects: a chloride independent increase in the surface area and the specific capacitance of the membrane, and a chloride dependent inhibition of the charge transfer and the electromotility in outer hair cells. We conclude that diflunisal affects the cell membrane organization and inhibits prestin-associated charge transfer and electromotility at physiological chloride concentrations. The inhibitory effects on hair cell function are noteworthy given the proposed use of diflunisal to treat neurodegenerative diseases.
- Nonsteroidal Anti-inflammatory Drugs (NSAIDS) Inhibit the Growth and Reproduction of Chaetomium globosum and Other Fungi Associated with Water-Damaged Buildings. [Journal Article]
- MMycopathologia 2017; 182(11-12):1025-1036
- Indoor mold due to water damage causes serious human respiratory disorders, and the remediation to homes, schools, and businesses is a major expense. Prevention of mold infestation of building materi...
Indoor mold due to water damage causes serious human respiratory disorders, and the remediation to homes, schools, and businesses is a major expense. Prevention of mold infestation of building materials would reduce health problems and building remediation costs. Nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit yeasts and a limited number of filamentous fungi. The purpose of this research was to determine the possible inhibitory activity of nonsteroidal anti-inflammatory drugs (NSAIDs) on germination, fungal growth, and reproduction of Chaetomium globosum and other important filamentous fungi that occur in water-damaged buildings. Several NSAIDs were found to inhibit C. globosum germination, growth, and reproduction. The most effective NSAIDs inhibiting C. globosum were ibuprofen, diflunisal, and diclofenac. Fusarium oxysporum, Fusarium solani, Aspergillus niger, and Stachybotrys atra were also tested on the various media with similar results obtained. However, F. oxysporum and A. niger exhibited a higher level of resistance to aspirin and NaSAL when compared to the C. globosum isolates. The inhibition exhibited by NSAIDs was variable depending on growth media and stage of fungal development. These compounds have a great potential of inhibiting fungal growth on building materials such as gypsum board. Formulations of sprays or building materials with NSAID-like chemical treatments may hold promise in reducing mold in homes and buildings.
- Peptide Half-Life Extension: Divalent, Small-Molecule Albumin Interactions Direct the Systemic Properties of Glucagon-Like Peptide 1 (GLP-1) Analogues. [Journal Article]
- JMJ Med Chem 2017 Sep 14; 60(17):7434-7446
- Noncovalent binding of biopharmaceuticals to human serum albumin protects against enzymatic degradation and renal clearance. Herein, we investigated the effect of mono- or divalent small-molecule alb...
Noncovalent binding of biopharmaceuticals to human serum albumin protects against enzymatic degradation and renal clearance. Herein, we investigated the effect of mono- or divalent small-molecule albumin binders for half-life extension of peptides. For proof-of-principle, the clinically relevant glucagon-like peptide 1 (GLP-1) was functionalized with diflunisal, indomethacin, or both. In vitro, all GLP-1 analogues had subnanomolar GLP-1 receptor potency. Surface plasmon resonance revealed that both small molecules were able to confer albumin affinity to GLP-1 and indicated that affinity is increased for divalent analogues. In lean mice, the divalent GLP-1 analogues were superior to monovalent analogues with respect to control of glucose homeostasis and suppression of food intake. Importantly, divalent GLP-1 analogues showed efficacy comparable to liraglutide, an antidiabetic GLP-1 analogue that carries a long-chain fatty acid. Finally, pharmacokinetic investigations of a divalent GLP-1 analogue demonstrated a promising gain in circulatory half-life and absorption time compared to its monovalent equivalent.
- Therapeutic Strategies Targeting Inherited Cardiomyopathies. [Review]
- CHCurr Heart Fail Rep 2017; 14(4):321-330
- Cardiomyopathies due to genetic mutations are a heterogeneous group of disorders that comprise diseases of contractility, myocardial relaxation, and arrhythmias. Our goal here is to discuss a limited...
Cardiomyopathies due to genetic mutations are a heterogeneous group of disorders that comprise diseases of contractility, myocardial relaxation, and arrhythmias. Our goal here is to discuss a limited list of genetically inherited cardiomyopathies and the specific therapeutic strategies used to treat them.
- Targeting the β-clamp in Helicobacter pylori with FDA-approved drugs reveals micromolar inhibition by diflunisal. [Letter]
- FLFEBS Lett 2017; 591(15):2311-2322
- The β-clamp is the processivity-promoting factor for most of the enzymes in prokaryotic DNA replication; hence, it is a crucial drug target. In the present study, we investigated the β-clamp from Hel...
The β-clamp is the processivity-promoting factor for most of the enzymes in prokaryotic DNA replication; hence, it is a crucial drug target. In the present study, we investigated the β-clamp from Helicobacter pylori, aiming to seek potential drug molecules against this gastric-cancer-causing bacterium. An in silico screening of Food and Drug Administration (FDA) approved drugs against the H. pylori β-clamp, followed by its in vitro inhibition using a surface competition approach, yielded the drug diflunisal as a positive initial hit. Diflunisal inhibits the growth of H. pylori in the micromolar range. We determined the structure of diflunisal in complex with the β-clamp to show that the drug binds at subsite I, which is a protein-protein interaction site. Successful identification of FDA-approved molecules against H. pylori may lead to better and faster drug development.
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- Characterization of a Francisella tularensis-Caenorhabditis elegans Pathosystem for the Evaluation of Therapeutic Compounds. [Journal Article]
- AAAntimicrob Agents Chemother 2017; 61(9)
- Francisella tularensisis a highly infectious Gram-negative intracellular pathogen that causes tularemia. Because of its potential as a bioterrorism agent, there is a need for new ...
Francisella tularensisis a highly infectious Gram-negative intracellular pathogen that causes tularemia. Because of its potential as a bioterrorism agent, there is a need for new therapeutic agents. We therefore developed a whole-animalCaenorhabditis elegans-F. tularensispathosystem for high-throughput screening to identify and characterize potential therapeutic compounds. We found that theC. elegansp38 mitogen-activate protein (MAP) kinase cascade is involved in the immune response toF. tularensis, and we developed a robustF. tularensis-mediatedC. eleganskilling assay with a Z' factor consistently of >0.5, which was then utilized to screen a library of FDA-approved compounds that included 1,760 small molecules. In addition to clinically used antibiotics, five FDA-approved drugs were also identified as potential hits, including the anti-inflammatory drug diflunisal that showed anti-F. tularensisactivityin vitroMoreover, the nonsteroidal anti-inflammatory drug (NSAID) diflunisal, at 4× MIC, blocked the replication of anF. tularensislive vaccine strain (LVS) in primary human macrophages and nonphagocytic cells. Diflunisal was nontoxic to human erythrocytes and HepG2 human liver cells at concentrations of ≥32 μg/ml. Finally, diflunisal exhibited synergetic activity with the antibiotic ciprofloxacin in both a checkerboard assay and a macrophage infection assay. In conclusion, the liquidC. elegans-F. tularensisLVS assay described here allows screening for anti-F. tularensiscompounds and suggests that diflunisal could potentially be repurposed for the management of tularemia.