Withaferin A Alters Intermediate Filament Organization, Cell Shape and Behavior

Withaferin A (WFA) is a steroidal lactone present in Withania somnifera which has been shown in vitro to bind to the intermediate filament protein, vimentin. Based upon its affinity for vimentin, it has been proposed that WFA can be used as an anti-tumor agent to target metastatic cells which up-regulate vimentin expression. We show that WFA treatment of human fibroblasts rapidly reorganizes vimentin intermediate filaments (VIF) into a perinuclear aggregate. This reorganization is dose dependent and is accompanied by a change in cell shape, decreased motility and an increase in vimentin phosphorylation at serine-38. Furthermore, vimentin lacking cysteine-328, the proposed WFA binding site, remains sensitive to WFA demonstrating that this site is not required for its cellular effects. Using analytical ultracentrifugation, viscometry, electron microscopy and sedimentation assays we show that WFA has no effect on VIF assembly in vitro. Furthermore, WFA is not specific for vimentin as it disrupts the cellular organization and induces perinuclear aggregates of several other IF networks comprised of peripherin, neurofilament-triplet protein, and keratin. In cells co-expressing keratin IF and VIF, the former are significantly less sensitive to WFA with respect to inducing perinuclear aggregates. The organization of microtubules and actin/microfilaments is also affected by WFA. Microtubules become wavier and sparser and the number of stress fibers appears to increase. Following 24 hrs of exposure to doses of WFA that alter VIF organization and motility, cells undergo apoptosis. Lower doses of the drug do not kill cells but cause them to senesce. In light of our findings that WFA affects multiple IF systems, which are expressed in many tissues of the body, caution is warranted in its use as an anti-cancer agent, since it may have debilitating organism-wide effects

Mathematical models for immunology:current state of the art and future research directions

The advances in genetics and biochemistry that have taken place over the last 10 years led to significant advances in experimental and clinical immunology. In turn, this has led to the development of new mathematical models to investigate qualitatively and quantitatively various open questions in immunology. In this study we present a review of some research areas in mathematical immunology that evolved over the last 10 years. To this end, we take a step-by-step approach in discussing a range of models derived to study the dynamics of both the innate and immune responses at the molecular, cellular and tissue scales. To emphasise the use of mathematics in modelling in this area, we also review some of the mathematical tools used to investigate these models. Finally, we discuss some future trends in both experimental immunology and mathematical immunology for the upcoming years

Neuronal Chemokines: Versatile Messengers In Central Nervous System Cell Interaction

Whereas chemokines are well known for their ability to induce cell migration, only recently it became evident that chemokines also control a variety of other cell functions and are versatile messengers in the interaction between a diversity of cell types. In the central nervous system (CNS), chemokines are generally found under both physiological and pathological conditions. Whereas many reports describe chemokine expression in astrocytes and microglia and their role in the migration of leukocytes into the CNS, only few studies describe chemokine expression in neurons. Nevertheless, the expression of neuronal chemokines and the corresponding chemokine receptors in CNS cells under physiological and pathological conditions indicates that neuronal chemokines contribute to CNS cell interaction. In this study, we review recent studies describing neuronal chemokine expression and discuss potential roles of neuronal chemokines in neuron–astrocyte, neuron–microglia, and neuron–neuron interaction

Measuring 129Xe transfer across the blood‐brain barrier using MR spectroscopy

Purpose This study develops a tracer kinetic model of xenon uptake in the human brain to determine the transfer rate of inhaled hyperpolarized 129Xe from cerebral blood to gray matter that accounts for the effects of cerebral physiology, perfusion and magnetization dynamics. The 129Xe transfer rate is expressed using a tracer transfer coefficient, which estimates the quantity of hyperpolarized 129Xe dissolved in cerebral blood under exchange with depolarized 129Xe dissolved in gray matter under equilibrium of concentration. Theory and Methods Time‐resolved MR spectra of hyperpolarized 129Xe dissolved in the human brain were acquired from three healthy volunteers. Acquired spectra were numerically fitted with five Lorentzian peaks in accordance with known 129Xe brain spectral peaks. The signal dynamics of spectral peaks for gray matter and red blood cells were quantified, and correction for the 129Xe T1 dependence upon blood oxygenation was applied. 129Xe transfer dynamics determined from the ratio of the peaks for gray matter and red blood cells was numerically fitted with the developed tracer kinetic model. Results For all the acquired NMR spectra, the developed tracer kinetic model fitted the data with tracer transfer coefficients between 0.1 and 0.14. Conclusion In this study, a tracer kinetic model was developed and validated that estimates the transfer rate of HP 129Xe from cerebral blood to gray matter in the human brain

Caregiver burden, productivity loss, and indirect costs associated with caring for patients with poststroke spasticity

Vaidyanathan Ganapathy,1 Glenn D Graham,2 Marco D DiBonaventura,3 Patrick J Gillard,1 Amir Goren,3 Richard D Zorowitz41Allergan, Irvine, CA, USA; 2Department of Veterans Affairs, San Francisco, CA, USA; 3Health Outcomes Practice, Kantar Health, New York, NY, USA; 4Johns Hopkins Bayview Medical Center, Baltimore, MD, USAObjective: Many stroke survivors experience poststroke spasticity and the related inability to perform basic activities, which necessitates patient management and treatment, and exerts a considerable burden on the informal caregiver. The current study aims to estimate burden, productivity loss, and indirect costs for caregivers of stroke survivors with spasticity.Methods: Internet survey data were collected from 153 caregivers of stroke survivors with spasticity including caregiving time and difficulty (Oberst Caregiver Burden Scale), Work Productivity and Activity Impairment measures, and caregiver and patient characteristics. Fractional logit models examined predictors of work-related restriction, and work losses were monetized (2012 median US wages).Results: Mean Oberst Caregiver Burden Scale time and difficulty scores were 46.1 and 32.4, respectively. Employed caregivers (n=71) had overall work restriction (32%), absenteeism (9%), and presenteeism (27%). Caregiver characteristics, lack of nursing home coverage, and stroke survivors’ disability predicted all work restriction outcomes. The mean total lost-productivity cost per employed caregiver was US835 per month (>10,000 per year; 72% attributable to presenteeism).Conclusion: These findings demonstrate the substantial burden of caring for stroke survivors with spasticity illustrating the societal and economic impact of stroke that extends beyond the stroke survivor.Keywords: burden, caregiver, productivity, spasticity, strok

Synthesis and metal(II) ion complexation of pyridine-2, 6-diamides incorporating amino alcohols

Reaction of 2,6-bis(methoxycarbonyl)pyridine with two equivalents of a β-amino alcohol yields pyridine-2,6-diamides C₆H₃N(CONH–CR₁R₂–CHR₃–OH)₂ [(1) R₁ = R₂ = R₃ = H; (2) R₁ = R₂ = H, R₃ = CH₃; (3) R₁ = CH₃, R2 = R₃ = H; (4) R₁ = C₂H₅, R₂ = R₃ = H; (5) R₁ = C₆H₅CH₂, R₂ = R₃ = H; (6) R₁ = O₂NC₆H₄CH(OH), R₂ = R₃ = H; (7) R₁ = R₂ = CH₃, R₃=H] incorporating the amino alcohols, several of which are chiral, whereas the free diamide ligands show no capacity toward deprotonation up to pH > 12. In the presence of metal(II) ions they undergo concomitant deprotonation and complexation to form [M(L-2H)] compounds. Formation constants have been determined for Cu(II), Ni(II), and Zn(II) complexes of the suite of ligands. Determined values for the two observed steps of log β ML-2H and log β ML-3H (where additional alcohol or coordinated water deprotonation occurs) are approximately −10 and −20, respectively. As pKa values of the diamide cannot be determined independently, absolute log KML-2H values for the di-deprotonated complexes cannot be definitively assigned, although estimates are made using predicted pKa values for the diamide. The circular dichroism spectra of optically active complexes were determined and are discussed