Joanne Stocks

Improved biocompatibility and pharmacokinetics of silica nanoparticles by means of a lipid coating: a multimodality investigation

Silica is a promising carrier material for nanoparticle-facilitated drug delivery, gene therapy, and molecular imaging. Understanding of their pharmacokinetics is important to resolve bioapplicability issues. Here we report an extensive study on bare and lipid-coated silica nanoparticles in mice. Results obtained by use of a wide variety of techniques (fluorescence imaging, inductively coupled plasma mass spectrometry, magnetic resonance imaging, confocal laser scanning microscopy, and transmission electron microscopy) showed that the lipid coating, which enables straightforward functionalization and introduction of multiple properties, increases bioapplicability and improves pharmacokinetics.

Human airway smooth muscle cells secrete vascular endothelial growth factor: up-regulation by bradykinin via a protein kinase C and prostanoid-dependent mechanism

Bronchial vascular remodeling is an important feature of the pathology of chronic asthma, but the responsible mechanisms and main sources of an‐giogenic factors are unclear. Here we report that human airway smooth muscle cells express vascular endo‐thelial growth factor (VEGF)121,165,189,206 splice variants and secrete VEGF protein constitutively. VEGF protein secretion was increased by the proinflammatory asthma mediator bradykinin through post‐transcrip‐tional mechanisms. Bradykinin‐induced VEGF secretion was dependent on the B2 bradykinin receptor activation of protein kinase C and generation of endogenous prostanoids. This is the first report that bradykinin can increase VEGF secretion in any biological system and the first to show that airway smooth muscle cells produce VEGF. Our results suggest a novel role for human airway smooth muscle in contributing to bronchial mucosal angiogenesis in chronic asthma by secretion of VEGF and suggest a wider role for mesen‐chymal cell products in mediating angiogenesis in inflammatory and allergic diseases.—Knox, A. J., Corbett, L., Stocks, J., Holland, E., Zhu, Y. M., Pang, L. Human airway smooth muscle cells secrete vascular endothelial growth factor: up‐regulation by bradykinin via a protein kinase C and prostanoid‐dependent mechanism. FASEB J. 15, 2480–2488 (2001)

Vascular Endothelial Growth Factor Induction by Prostaglandin E2 in Human Airway Smooth Muscle Cells Is Mediated by E Prostanoid EP2/EP4 Receptors and SP-1 Transcription Factor Binding Sites

Prostaglandin E2 (PGE2) can increase thelial vascular endogrowth factor A (VEGF-A) production but the mechanisms involved are unclear. Here we characterized the transcriptional mechanisms involved in human airway smooth muscle cells (HASMC). PGE2 increased VEGF-A mRNA and protein but not mRNA stability. PGE2 stimulated the activity of a transiently transfected 2068-bp (–2018 to +50) VEGF-A promoter-driven luciferase construct. Functional 5′ deletional analysis mapped the PGE2 response element to the 135-bp sequence (–85/ +50) of the human VEGF-A promoter. PGE2-induced luciferase activity was reduced in cells transfected with a 135-bp VEGF promoter fragment containing mutated Sp-1 binding sites but not in cells transfected with a construct containing mutated EGR-1 binding sites. Electrophoretic mobility shift assay and chromatin immunoprecipitation assay confirmed binding of Sp-1 to the VEGF promoter. PGE2 increased phosphorylation of Sp-1 and luciferase activity of a transfected Sp-1 reporter construct. PGE receptor agonists EP2 (ONO-AE1 259) and EP4 (ONO-AE1 329) mimicked the effect of PGE2, and reverse transcription-PCR, Western blotting, and flow cytometry confirmed the presence of EP2 and EP4 receptors. VEGF protein release and Sp-1 reporter activity were increased by forskolin and isoproterenol, which increase cytosolic cAMP, and the cAMP analogue, 8-bromoadenosine-3′,5′-cyclophosphoric acid. These studies suggest that PGE2 increases VEGF transcriptionally and involves the Sp-1 binding site via a cAMP-dependent mechanism involving EP2 and EP4 receptors.

The effect of proactively identifying smokers and offering smoking cessation support in primary care populations: a cluster-randomized trial.

AIMS To establish whether proactively identifying all smokers in primary care populations and offering smoking cessation support is effective in increasing long-term abstinence from smoking. DESIGN Cluster randomized controlled trial. SETTING Twenty-four general practices in Nottinghamshire, randomized by practice to active or control intervention. PARTICIPANTS All adult patients registered with the practices who returned a questionnaire confirming that they were current smokers (n = 6856). INTERVENTION Participants were offered smoking cessation support by letter and those interested in receiving it were contacted and referred into National Health Service (NHS) stop smoking services if required. MEASUREMENTS Validated abstinence from smoking, use of smoking cessation services and number of quit attempts in continuing smokers at 6 months. FINDINGS Smokers in the intervention group were more likely than controls to report that they had used local cessation services during the study period [16.6% and 8.9%, respectively, adjusted odds ratio (OR) 2.09, 95% confidence interval (CI) 1.57-2.78], and continuing smokers (in the intervention group) were more likely to have made a quit attempt in the last 6 months (37.4% and 33.3%, respectively, adjusted OR 1.23, 95% CI 1.01-1.51). Validated point prevalence abstinence from smoking at 6 months was higher in the intervention than the control groups (3.5% and 2.5%, respectively) but the difference was not statistically significant (adjusted OR controlling for covariates: 1.64, 95% CI 0.92-2.89). CONCLUSIONS Proactively identifying smokers who want to quit in primary care populations, and referring them to a cessation service, increased contacts with cessation services and the number of quit attempts. We were unable to detect a significant effect on long-term cessation rates, but the study was not powered to detect the kind of difference that might be expected.

Cytokines upregulate vascular endothelial growth factor secretion by human airway smooth muscle cells: Role of endogenous prostanoids

Here, we report that vascular endothelial growth factor (VEGF)‐A secretion by human airway smooth muscle cells was increased by interleukin 1 beta (IL‐1β) and transforming growth factor beta (TGFβ). IL‐1β and TGFβ induced cyclo‐oxygenase (COX)‐2 protein and increased prostaglandin E2 (PGE2). Both IL‐1β and TGFβ increased VEGF‐A165 mRNA and VEGF promoter luciferase construct activity, in addition VEGF‐A protein was inhibited by actinomycin D suggesting transcriptional regulation. The COX inhibitors indomethacin and NS398 inhibited IL‐1β but not TGFβ mediated VEGF‐A production. Furthermore, the effect of the COX inhibitors was overcome by adding exogenous PGE2. In conclusion, IL‐1β increases VEGF‐A secretion by COX‐2 derived PGE2 production whereas TGFβ uses COX‐independent pathways.

β-Adrenergic receptor activation induces internalization of cardiac Cav1.2 channel complexes through a β-arrestin 1-mediated pathway

Voltage-dependent calcium channels (VDCCs) play a pivotal role in normal excitation-contraction coupling in cardiac myocytes. These channels can be modulated through activation of β-adrenergic receptors (β-ARs), which leads to an increase in calcium current (ICa-L) density through cardiac Cav1 channels as a result of phosphorylation by cAMP-dependent protein kinase A. Changes in ICa-L density and kinetics in heart failure often occur in the absence of changes in Cav1 channel expression, arguing for the importance of post-translational modification of these channels in heart disease. The precise molecular mechanisms that govern the regulation of VDCCs and their cell surface localization remain unknown. Our data show that sustained β-AR activation induces internalization of a cardiac macromolecular complex involving VDCC and β-arrestin 1 (β-Arr1) into clathrin-coated vesicles. Pretreatment of myocytes with pertussis toxin prevents the internalization of VDCCs, suggesting that Gi/o mediates this response. A peptide that selectively disrupts the interaction between CaV1.2 and β-Arr1 and tyrosine kinase inhibitors readily prevent agonist-induced VDCC internalization. These observations suggest that VDCC trafficking is mediated by G protein switching to Gi of the β-AR, which plays a prominent role in various cardiac pathologies associated with a hyperadrenergic state, such as hypertrophy and heart failure.

Angiogenesis and vascular endothelial growth factor in COPD

A possible role for VEGF in the pathology of asthma and COPD It has been recognised for several hundred years that the bronchial vasculature is an extensive one with early descriptions by Ruysch and possibly Da Vinci.1 However, its function and regulation in health and in disease remain poorly understood. Studies a number of years ago suggested an increased number of bronchial vessels in asthma where increased collagen IV staining, a marker of new vessels, was seen in bronchial biopsies of asthmatic airways compared with controls.2 Subsequent studies by the same group and by Salvato and colleagues have confirmed the presence of angiogenesis in the bronchial circulation in asthma.3,4 There are a number of candidate angiogenic factors for these changes, perhaps the most important of which are vascular endothelial growth factor (VEGF) and the angiopoietins which are distinct molecules that act together at different stages of angiogenic processes in several biological systems.5,6,7,8,9,10,11 Other molecules with angiogenic potential are fibroblast growth factor,9 angiogenin,9 and chemokines such as interleukin (IL)-812 and eotaxin.13 Interestingly, angiogenesis seems to be a feature of inflammatory diseases at a number of sites in the body including the joints14 and the gut.15 The study published in this issue of Thorax by Kranenburg and colleagues16 suggests that bronchial vascular changes may also occur in chronic obstructive …

SAT0670 The prevalence of neuropathic pain-like symptoms and associated risk factors in the nottingham community: a cross-sectional study

Background Knee pain (KP) affects 1 in 4 adults over the age of 50. Aside from structural joint changes, person-specific factors influence the KP experience. Increased central sensitisation of neural pathways due to localised joint pain or ineffective descending inhibitory mechanisms can cause an enhanced pain response and neuropathic pain-like (NP) symptoms. Understanding these person-specific factors and how they modulate the pain experience might help profile different KP and NP phenotypes. Objectives a) To determine the prevalence of NP in a KP community population b) to identify significant risk factors associated with NP and those with both NP and non-NP KP. Methods 9,513 men and women, aged 40+ years, were recruited from the East Midlands region (United Kingdom) via postal questionnaire. The questionnaire included sections on KP severity (numerical rating scale) and type (NP versus nociceptive) using the modified PainDETECT Questionnaire (mPDQ); quality of KP using the intermittent and constant osteoarthritis pain (ICOAP) instrument) as well as other risk factors including age, body mass index (BMI), injury, pain catastrophizing scale (PCS) and mental wellness (Hospital Anxiety and Depression Scale). KP participants were those who reported “knee pain for most days of the past one month” while likely NP was mPDQ scores of ≥13 and definite NP, ≥19. Differences between groups were assessed using t-tests for continuous data and chi2 for categorical data. We used multinomial regression analysis to determine the odds ratios (ORs) of risk factors with 95% confidence intervals (CI) and significance set p<0.05. Results The prevalence of definite NP in the Nottingham Community was 366 (13.62%). There were more women (p=0.04) and higher BMI (p<0.001) in KP vs. non-KP responders but no age difference (p>0.05). When comparing the neuropathic-like KP to non-neuropathic KP responders, significant risk factors after adjustment for age, BMI, gender and pain severity included: anxiety (OR 3.17 (95% CI 2.38;4.23)); depression (OR 2.99 (95% CI 2.14;4.19)); PCS in highest tertile (OR 5.39 (95% CI 2.94;9.88)); fibromyalgia (OR 4.06 (95% CI 2.48;6.66)) and previous knee injury (OR 1.5 (95% CI 1.12;2.00)). When comparing neuropathic-like KP to non-KP responders, anxiety (1.74 (95% CI 1.31; 2.30), depression (2.05 (95% CI 1.40; 3.01), PCS 3.78 (95% CI 2.57; 5.56)), fibromyalgia (OR 1.94 (95% CI 1.10; 3.40)) and previous injury (OR 1.35 (95% CI 1.05; 1.73)) were significant risk factors after adjustment. Conclusions This is the first population based cross-sectional study in the UK to determine prevalence of NP in people with KP. The results suggest that both psychological factors (depression, anxiety, high catastrophising) and peripheral risk factors (injury) associate with NP reporting. These factors can augment pain sensitivity and produce an amplified response via central and peripheral pathways. Phenotypes based on these risk factor profiles may warrant specific management in KP populations. Acknowledgements Arthritis Research UK Grant Refs: 20777, 20194 Disclosure of Interest None declared

Traits associated with central pain augmentation in the Knee Pain in the Community (KPIC) cohort

Abstract This study aimed to identify self-report correlates of central pain augmentation in individuals with knee pain. A subset of participants (n = 420) in the Knee Pain and related health In the Community (KPIC) baseline survey undertook pressure pain detection threshold (PPT) assessments. Items measuring specific traits related to central pain mechanisms were selected from the survey based on expert consensus, face validity, item association with underlying constructs measured by originating host questionnaires, adequate targeting, and PPT correlations. Pain distribution was reported on a body manikin. A “central pain mechanisms” factor was sought by factor analysis. Associations of items, the derived factor, and originating questionnaires with PPTs were compared. Eight self-report items measuring traits of anxiety, depression, catastrophizing, neuropathic-like pain, fatigue, sleep disturbance, pain distribution, and cognitive impact were identified as likely indices of central pain mechanisms. Pressure pain detection thresholds were associated with items representing each trait and with their originating scales. Pain distribution classified as “pain below the waist additional to knee pain” was more strongly associated with low PPT than were alternative classifications of pain distribution. A single factor, interpreted as “central pain mechanisms,” was identified across the 8 selected items and explained variation in PPT (R2 = 0.17) better than did any originating scale (R2 = 0.10-0.13). In conclusion, including representative items within a composite self-report tool might help identify people with centrally augmented knee pain.

New therapeutic targets for osteoarthritis pain

Osteoarthritis (OA), the most common form of arthritis, causes pain and disability, as well as emotional distress. While total joint replacement is one of the most effective treatments available for improving the quality of life in people with severe OA, it is not suitable for all patients and all joints. Current pharmacological analgesics have limited efficacy, and their use is often restricted by adverse events. Medications that might reduce pain by slowing or preventing structural disease remain elusive. Our increasing understanding of the complex mechanisms that underlie OA pain offers a wide range of potential new treatment targets. New drugs for OA pain might come from repurposing those developed for other conditions, as well as novel compounds targeting pain mechanisms specific to the joint. Here we discuss the mechanisms of OA pain and its therapeutic implications. We explore evolving treatment modalities, including combination treatment. We review recent research and patents pointing to future OA therapies. We discuss the potential for biomarkers to facilitate drug development and targeting.