(-)-Epigallocatechin-3-gallate (EGCG) maintains k-casein in its pre-fibrillar state without redirecting its aggregation pathway

The polyphenol (-)-epigallocatechin-3-gallate (EGCG) has recently attracted much research interest in the field of protein-misfolding diseases because of its potent anti-amyloid activity against amyloid-beta, alpha-synuclein and huntingtin, the amyloid-fibril-forming proteins involved in Alzheimer\u27s, Parkinson\u27s and Huntington\u27s diseases, respectively. EGCG redirects the aggregation of these polypeptides to a disordered off-folding pathway that results in the formation of non-toxic amorphous aggregates. whether this anti-fibril activity is specific to these disease-related target proteins or ismore generic remains to be established. In addition, the mechanism by which EGCG exerts its effects, as with all anti-amyloidogenic polyphenols, remains unclear. To address these aspects, we have investigated the ability of EGCG to inhibit amyloidogenesis of the generic model fibril-forming protein RCMkappa-CN (reduced and carboxymethylated kappa-casein) and thereby protect pheochromocytoma-12 cells from RCMkappa-CN amyloid-induced toxicity. We found that EGCG potently inhibits in vitro fibril formation byRCMkappa-CN [the IC50 for 50 uM RCMkappa-CN is 1 uM]. Biophysical studies reveal that EGCG prevents RCMkappa-CN fibril formation by stabilising RCMkappa-CN in its nativelike state rather than by redirecting its aggregation to the disordered, amorphous aggregation pathway. Thus, while it appears that EGCG is a generic inhibitor of amyloid-fibril formation, the mechanism by which it achieves this inhibition is specific to the target fibril-forming polypeptide. It is proposed that EGCG is directed to the amyloidogenic sheet-turn-sheet motif of monomeric RCMkappa-CN with high affinity by strong non-specific hydrophobic associations. Additional non-covalent pi-pi stacking interactions between the polyphenolic and aromatic residues common to the amyloidogenic sequence are also implicated

(-)-Epigallocatechin-3-gallate (EGCG) maintains k-casein in its pre-fibrillar state without redirecting its aggregation pathway

The polyphenol (-)-epigallocatechin-3-gallate (EGCG) has recently attracted much research interest in the field of protein-misfolding diseases because of its potent anti-amyloid activity against amyloid-beta, alpha-synuclein and huntingtin, the amyloid-fibril-forming proteins involved in Alzheimer\u27s, Parkinson\u27s and Huntington\u27s diseases, respectively. EGCG redirects the aggregation of these polypeptides to a disordered off-folding pathway that results in the formation of non-toxic amorphous aggregates. whether this anti-fibril activity is specific to these disease-related target proteins or ismore generic remains to be established. In addition, the mechanism by which EGCG exerts its effects, as with all anti-amyloidogenic polyphenols, remains unclear. To address these aspects, we have investigated the ability of EGCG to inhibit amyloidogenesis of the generic model fibril-forming protein RCMkappa-CN (reduced and carboxymethylated kappa-casein) and thereby protect pheochromocytoma-12 cells from RCMkappa-CN amyloid-induced toxicity. We found that EGCG potently inhibits in vitro fibril formation byRCMkappa-CN [the IC50 for 50 uM RCMkappa-CN is 1 uM]. Biophysical studies reveal that EGCG prevents RCMkappa-CN fibril formation by stabilising RCMkappa-CN in its nativelike state rather than by redirecting its aggregation to the disordered, amorphous aggregation pathway. Thus, while it appears that EGCG is a generic inhibitor of amyloid-fibril formation, the mechanism by which it achieves this inhibition is specific to the target fibril-forming polypeptide. It is proposed that EGCG is directed to the amyloidogenic sheet-turn-sheet motif of monomeric RCMkappa-CN with high affinity by strong non-specific hydrophobic associations. Additional non-covalent pi-pi stacking interactions between the polyphenolic and aromatic residues common to the amyloidogenic sequence are also implicated

Eukaryotic Cell Toxicity and HSA Binding of [Ru(Me4phen)(bb7)]2+ and the Effect of Encapsulation in Cucurbit[10]uril

The toxicity (IC50) of a series of mononuclear ruthenium complexes containing bis[4(4′-methyl-2,2′-bipyridyl)]-1,n-alkane (bbn) as a tetradentate ligand against three eukaryotic cell lines—BHK (baby hamster kidney), Caco-2 (heterogeneous human epithelial colorectal adenocarcinoma) and Hep-G2 (liver carcinoma)—have been determined. The results demonstrate that cis-α-[Ru(Me4phen)(bb7)]2+ (designated as α-Me4phen-bb7, where Me4phen = 3,4,7,8-tetramethyl-1,10-phenanthroline) showed little toxicity toward the three cell lines, and was considerably less toxic than cis-α-[Ru(phen)(bb12)]2+ (α-phen-bb12) and the dinuclear complex [{Ru(phen)2}2{μ-bb12}]4+. Fluorescence spectroscopy was used to study the binding of the ruthenium complexes with human serum albumin (HSA). The binding of α-Me4phen-bb7 to the macrocyclic host molecule cucurbit[10]uril (Q[10]) was examined by NMR spectroscopy. Large upfield 1H NMR chemical shift changes observed for the methylene protons in the bb7 ligand upon addition of Q[10], coupled with the observation of several intermolecular ROEs in ROESY spectra, indicated that α-Me4phen-bb7 bound Q[10] with the bb7 methylene carbons within the cavity and the metal center positioned outside one of the portals. Simple molecular modeling confirmed the feasibility of the binding model. An α-Me4phen-bb7-Q[10] binding constant of 9.9 ± 0.2 × 106 M−1 was determined by luminescence spectroscopy. Q[10]-encapsulation decreased the toxicity of α-Me4phen-bb7 against the three eukaryotic cell lines and increased the binding affinity of the ruthenium complex for HSA. Confocal microscopy experiments indicated that the level of accumulation of α-Me4phen-7 in BHK cells is not significantly affected by Q[10]-encapsulation. Taken together, the combined results suggest that α-Me4phen-7 could be a good candidate as a new antimicrobial agent, and Q[10]-encapsulation could be a method to improve the pharmacokinetics of the ruthenium complex

Leukotriene antagonists as first-line or add-on asthma controller therapy

Most randomized trials of treatment for asthma study highly selected patients under idealized conditions. METHODS: We conducted two parallel, multicenter, pragmatic trials to evaluate the real-world effectiveness of a leukotriene-receptor antagonist (LTRA) as compared with either an inhaled glucocorticoid for first-line asthma-controller therapy or a long-acting beta(2)-agonist (LABA) as add-on therapy in patients already receiving inhaled glucocorticoid therapy. Eligible primary care patients 12 to 80 years of age had impaired asthma-related quality of life (Mini Asthma Quality of Life Questionnaire [MiniAQLQ] score =6) or inadequate asthma control (Asthma Control Questionnaire [ACQ] score =1). We randomly assigned patients to 2 years of open-label therapy, under the care of their usual physician, with LTRA (148 patients) or an inhaled glucocorticoid (158 patients) in the first-line controller therapy trial and LTRA (170 patients) or LABA (182 patients) added to an inhaled glucocorticoid in the add-on therapy trial. RESULTS: Mean MiniAQLQ scores increased by 0.8 to 1.0 point over a period of 2 years in both trials. At 2 months, differences in the MiniAQLQ scores between the two treatment groups met our definition of equivalence (95% confidence interval [CI] for an adjusted mean difference, -0.3 to 0.3). At 2 years, mean MiniAQLQ scores approached equivalence, with an adjusted mean difference between treatment groups of -0.11 (95% CI, -0.35 to 0.13) in the first-line controller therapy trial and of -0.11 (95% CI, -0.32 to 0.11) in the add-on therapy trial. Exacerbation rates and ACQ scores did not differ significantly between the two groups. CONCLUSIONS: Study results at 2 months suggest that LTRA was equivalent to an inhaled glucocorticoid as first-line controller therapy and to LABA as add-on therapy for diverse primary care patients. Equivalence was not proved at 2 years. The interpretation of results of pragmatic research may be limited by the crossover between treatment groups and lack of a placebo group

Defining and unpacking the core concepts of pharmacology education

Pharmacology education currently lacks a research-based consensus on which core concepts all graduates should know and understand, as well as a valid and reliable means to assess core conceptual learning. The Core Concepts in Pharmacology Expert Group (CC-PEG) from Australia and New Zealand recently identified a set of core concepts of pharmacology education as a first step toward developing a concept inventory—a valid and reliable tool to assess learner attainment of concepts. In the current study, CC-PEG used established methodologies to define each concept and then unpack its key components. Expert working groups of three to seven educators were formed to unpack concepts within specific conceptual groupings: what the body does to the drug (pharmacokinetics); what the drug does to the body (pharmacodynamics); and system integration and modification of drug–response. First, a one-sentence definition was developed for each core concept. Next, sub-concepts were established for each core concept. These twenty core concepts, along with their respective definitions and sub-concepts, can provide pharmacology educators with a resource to guide the development of new curricula and the evaluation of existing curricula. The unpacking and articulation of these core concepts will also inform the development of a pharmacology concept inventory. We anticipate that these resources will advance further collaboration across the international pharmacology education community to improve curricula, teaching, assessment, and learning.Marina Santiago, Elizabeth A. Davis, Tina Hinton, Thomas A. Angelo, Alison Shield, Anna-Marie Babey, Barbara Kemp-Harper, Gregg Maynard, Hesham S. Al-Sallami, Ian F. Musgrave, Lynette B. Fernandes, Suong N. T. Ngo, Arthur Christopoulos, Paul J. Whit

Myoblast sensitivity and fibroblast insensitivity to osteogenic conversion by BMP-2 correlates with the expression of Bmpr-1a

<p>Abstract</p> <p>Background</p> <p>Osteoblasts are considered to primarily arise from osseous progenitors within the periosteum or bone marrow. We have speculated that cells from local soft tissues may also take on an osteogenic phenotype. Myoblasts are known to adopt a bone gene program upon treatment with the osteogenic bone morphogenetic proteins (BMP-2,-4,-6,-7,-9), but their osteogenic capacity relative to other progenitor types is unclear. We further hypothesized that the sensitivity of cells to BMP-2 would correlate with BMP receptor expression.</p> <p>Methods</p> <p>We directly compared the BMP-2 sensitivity of myoblastic murine cell lines and primary cells with osteoprogenitors from osseous tissues and fibroblasts. Fibroblasts forced to undergo myogenic conversion by transduction with a MyoD-expressing lentiviral vector (LV-MyoD) were also examined. Outcome measures included alkaline phosphatase expression, matrix mineralization, and expression of osteogenic genes <it>(alkaline phosphatase, osteocalcin </it>and <it>bone morphogenetic protein receptor-1A) </it>as measured by quantitative PCR.</p> <p>Results</p> <p>BMP-2 induced a rapid and robust osteogenic response in myoblasts and osteoprogenitors, but not in fibroblasts. Myoblasts and osteoprogenitors grown in osteogenic media rapidly upregulated <it>Bmpr-1a </it>expression. Chronic BMP-2 treatment resulted in peak <it>Bmpr-1a </it>expression at day 6 before declining, suggestive of a negative feedback mechanism. In contrast, fibroblasts expressed low levels of <it>Bmpr-1a </it>that was only weakly up-regulated by BMP-2 treatment. Bioinformatics analysis confirmed the presence of myogenic responsive elements in the proximal promoter region of human and murine <it>BMPR-1A/Bmpr-1a</it>. Forced myogenic gene expression in fibroblasts was associated with a significant increase in <it>Bmpr-1a </it>expression and a synergistic increase in the osteogenic response to BMP-2.</p> <p>Conclusion</p> <p>These data demonstrate the osteogenic sensitivity of muscle progenitors and provide a mechanistic insight into the variable response of different cell lineages to BMP-2.</p

Defining and unpacking the core concepts of pharmacology education

Pharmacology education currently lacks a research-based consensus on which core concepts all graduates should know and understand, as well as a valid and reliable means to assess core conceptual learning. The Core Concepts in Pharmacology Expert Group (CC-PEG) from Australia and New Zealand recently identified a set of core concepts of pharmacology education as a first step toward developing a concept inventory—a valid and reliable tool to assess learner attainment of concepts. In the current study, CC-PEG used established methodologies to define each concept and then unpack its key components. Expert working groups of three to seven educators were formed to unpack concepts within specific conceptual groupings: what the body does to the drug (pharmacokinetics); what the drug does to the body (pharmacodynamics); and system integration and modification of drug–response. First, a one-sentence definition was developed for each core concept. Next, sub-concepts were established for each core concept. These twenty core concepts, along with their respective definitions and sub-concepts, can provide pharmacology educators with a resource to guide the development of new curricula and the evaluation of existing curricula. The unpacking and articulation of these core concepts will also inform the development of a pharmacology concept inventory. We anticipate that these resources will advance further collaboration across the international pharmacology education community to improve curricula, teaching, assessment, and learning