• Anti-tumour necrosis factor alpha therapy improves insulin sensitivity in normal-weight but not in obese patients with rheumatoid arthritis

      Stavropoulos-Kalinoglou, A; Metsios, GS; Panoulas, VF; Nightingale, P; Koutedakis, Y; Kitas, GD (Springer Science and Business Media LLC, 2012-07-05)
      Introduction: Insulin resistance (IR), a risk factor for the development of cardiovascular disease, is common among patients with rheumatoid arthritis (RA). Inflammation, and especially tumour necrosis factor alpha (TNFα), has been associated with IR, and the administration of anti-TNFα agents is suggested to improve insulin sensitivity. However obesity, a potent contributor to IR, may limit the beneficial effects of anti-TNFα medication on IR. The aim of this study is to compare the effects of anti-TNFα therapy on IR between normal-weight and obese patients with RA.Methods: Patients who were normal-weight with IR (N+IR) or obese with IR (O+IR) and had embarked on anti-TNFα treatment, participated. Assessments included body mass index (BMI), insulin sensitivity (Homeostasis Model Assessment of insulin resistance, HOMA and the Quantitative Insulin sensitivity Check Index, QUICKI), and RA disease characteristics before and following six months of anti-TNFα treatment. Their results were compared to matched (for age, gender, BMI, disease duration and smoking status) normal-weight patients without IR (N-IR) and obese without IR (N-IR), respectively. In total, 32 patients were assessed for this study, with 8 in each group.Results: Following six months of treatment, disease activity was significantly reduced in all groups (P < 0.05) to a similar extent (P for differences between groups > 0.05 in all cases). In the total population, changes in HOMA (mean reduction at 6 m = -0.2 ± 0.1; P = 0.088) and QUICKI (mean increase at 6 m = 0.03 ± 0.022; P = 0.092) after treatment were not statistically significant, though a trend towards improvement was observed. However, N+IR patients showed a significant decrease in HOMA (mean reduction at 6 m = -0.54 ± 0.2; P = 0.002) and increase in QUICKI (mean increase at 6 m = 0.046 ± 0.02; P = 0.011). These changes were significantly different compared to the other groups (P < 0.05 in all cases). Multivariable analyses showed that the change in Erythrocyte Sedimentation Rate (ESR), and the change in C-Reactive Protein (CRP) associated with the improvement in HOMA (ESR: F 1-7 = 5.143, P = 0.019; CRP: F 1-7 = 3.122, P = 0.022) and QUICKI (ESR: F 1-7 = 3.814, P = 0.021; CRP: F 1-7 = 2.67; P = 0.041) only in the N+IR group.Conclusions: Anti-TNFα therapy, through controlling inflammation, seems to improve insulin sensitivity in normal-weight RA patients with insulin resistance, but is not sufficient to achieving the same beneficial effect in obese RA patients with insulin resistance. © 2012 Stavropoulos-Kalinoglou et al.; licensee BioMed Central Ltd.
    • Cellular pathology of atherosclerosis: smooth muscle cells promote adhesion of platelets to cocultured endothelial cells.

      Tull, Samantha P.; Anderson, Stephen I.; Hughan, Sascha C.; Watson, Steve P.; Nash, Gerard B.; Rainger, G.E. (American Heart Association, Inc., 2006)
      Although platelets do not ordinarily bind to endothelial cells (EC), pathological interactions between platelets and arterial EC may contribute to the propagation of atheroma. Previously, in an in vitro model of atherogenesis, where leukocyte adhesion to EC cocultured with smooth muscle cells was greatly enhanced, we also observed attachment of platelets to the EC layer. Developing this system to specifically model platelet adhesion, we show that EC cocultured with smooth muscle cells can bind platelets in a process that is dependent on EC activation by tumor necrosis factor (TNF)-alpha and transforming growth factor (TGF)-beta1. Recapitulating the model using EC alone, we found that a combination of TGF-beta1 and TNF-alpha promoted high levels of platelet adhesion compared with either agent used in isolation. Platelet adhesion was inhibited by antibodies against GPIb-IX-V or alpha(IIb)beta3 integrin, indicating that both receptors are required for stable adhesion. Platelet activation during interaction with the EC was also essential, as treatment with prostacyclin or theophylline abolished stable adhesion. Confocal microscopy of the surface of EC activated with TNF-alpha and TGF-beta1 revealed an extensive matrix of von Willebrand factor that was able to support the adhesion of flowing platelets at wall shear rates below 400 s(-1). Thus, we have demonstrated a novel route of EC activation which is relevant to the atherosclerotic microenvironment. EC activated in this manner would therefore be capable of recruiting platelets in the low-shear environments that commonly exist at points of atheroma formation.
    • Molecular and cellular mechanisms implicated in the regulation of cellular PMCA expression during pulmonary arterial hypertension

      Armesilla, Angel; Ihugba, Jude C; Research Institute in Healthcare Science, Faculty of Science and Engineering (University of Wolverhampton, 2022)
      Pulmonary arterial hypertension (PAH) is a rare, life-threatening disorder typified by elevated pulmonary vascular resistance, right ventricular hypertrophy, right heart failure and ultimately death. This disease has no current cure and available therapies alleviate vasoconstriction but do not address the disorder associated vascular remodelling. Amplified activity of pro-inflammatory cytokines has been linked to PAH development and progression. The aberrant re-modelling of the vasculature is in part dependent on the altered immune response driven by elevated synthesis of cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β and interleukin (IL)-6 which are known inducers of PAH. Furthermore, the apoptotic pathway driven by TNF-α has been shown to be calcium dependent, and several studies have confirmed the increased concentration of cytosolic calcium as a key molecular influence in cell mediated vasoconstriction and proliferation. This necessitates the need for determination of the activity of calcium ion regulators. The Plasma Membrane Calcium ATPase (PMCA) proteins are high affinity pumps which extrude calcium ions extracellularly. Four PMCA Genes have been characterized (PMCA 1, 2, 3 and 4). PMCA 1 and 4 are highly expressed in the vasculature particularly, in endothelial and smooth muscle cells. In this study, the contributory role of the PMCA genes to the development of PAH was determined. The results show that pro-inflammatory inducers of PAH elicited a significant time and dose dependent reduction (~ 40-50% reduction) of PMCA4 in human pulmonary artery endothelial cells at the mRNA and protein level. Further data obtained equally show that the silencing of PMCA4 in pulmonary artery endothelial cells (PAEC) sensitized PAEC to TNF-α induced apoptosis; approximately 30% more apoptotic cells were noted in PMCA4 silenced PAEC in the presence of TNF-α. This suggests that PMCA4 shields PAEC to apoptosis in the vasculature. The results obtained demonstrate that PMCA4 contributes to initial apoptosis driven loss of endothelial cells which is regarded as an important feature in the development of PAH through yet to be elucidated mechanisms.
    • New resting energy expenditure prediction equations for patients with rheumatoid arthritis

      Metsios, Giorgos S.; Stavropoulos-Kalinoglou, Antonios; Panoulas, Vasileios F.; Koutedakis, Yiannis; Nevill, Alan M.; Douglas, Karen M. J.; Kita, Marina D.; Kitas, George D. (Oxford University Press, 2008)
      OBJECTIVES: Resting energy expenditure (REE), one of the main components of total energy expenditure, can be measured via indirect calorimetry and/or predicted from equations. The latter may be misleading in RA, as they do not take into account the metabolic alterations occurring in RA. The objectives of this study are to evaluate the accuracy of widely used REE-predictive equations in RA patients against measured REE and to develop RA-specific equations. METHODS: We assessed REE (via indirect calorimetry and several predictive equations), fat-free mass (FFM; via bioelectrical impedance) and disease activity (CRP) in RA patients and healthy controls. Data from 60 RA patients (experimental group) were used to assess the accuracy of existing REE equations and to develop new equations. The new equations were validated in an independent cross-validation group of 22 RA patients. These two groups were merged and two final equations were developed. RESULTS: All equations significantly under-predicted measured REE (from 15% to 18.2%, all at P < 0.001) in the RA experimental group, but not in the control group. After both equations demonstrated a high validity in the cross-validation group, the new final REE prediction equations developed from the total RA sample (n = 82) were: Model 1: REE (kcal/day) = 126.1 x FFM(0.638) x CRP(0.045) (R(2) = 0.70) and Model 2: REE (kcal/day) = 598.8 x weight(0.47) x age(-0.29) x CRP(0.066) (R(2) = 0.62). CONCLUSION: The new equations provide an accurate prediction of REE in RA patients and could be used for clinical monitoring of resting metabolism of these patients without the requirement for specialized personnel.
    • Prospective study of immunological factors in non-inflammatory bowel disease enterocutaneous fistulas

      Rahbour, G; Hart, AL; Al-Hassi, Hafid Omar; Ullah, MR; Gabe, SM; Knight, SC; Warusavitarne, J; Vaizey, CJ; Colorectal and Intestinal Failure Surgery, St, Mark's Hospital and Academic Institute Watford Road, Harrow, Middlesex, HA1 3UJ, UK. g.rahbour10@imperial.ac.uk (Springer Science and Business Media LLC, 2011-05-27)
      Background: Enterocutaneous fistulas (ECF) are debilitating and usually result following complex abdominal surgery. While there is an association with inflammatory bowel disease (IBD), a large number of fistulas occur after surgery not related to IBD. The consequences of ECF include short bowel syndrome and the need for long term parenteral nutrition. ECF can heal spontaneously and in the case of IBD can be cured by medical therapy in some instances. Those that do not resolve spontaneously have to be cured by surgery which is complex and associated with a high morbidity. It is not considered traditional treatment to use the same medical therapy as in IBD to cure ECF caused by other conditions. A small case series has reported three patients with persistent ECF not related to IBD to have healed following use of Infliximab which is the treatment commonly used for ECF caused by IBD. Infliximab acts by inhibiting the activity of the inflammatory cytokine TNF- alpha. It is not known if this cytokine is present in ECF tissue in the absence of IBD. The aim of this study is to demonstrate the presence of inflammatory markers in tissue surrounding non-IBD ECF and in particular to quantify the presence of the cytokine TNF- alpha. We hypothesise that TNF - alpha levels are raised in non-IBD ECF. Methods/Design. Tissue and serum from ECF of IBD and non-IBD patients will be prospectively collected at St. Mark's Hospital Intestinal Failure Unit. The control group will consist of patients undergoing colonoscopy for bowel cancer screening, with normal findings. Biopsies of the terminal ileum will be obtained from this group during colonoscopy. The fistula tract and serum cytokine profiles of interleukins (IL)-1a, IL-1b, IL-2, IL-4, IL-6, IL-8, IL-10, TNF- alpha, IFN-y, MCP-1, EGF and VEGF will be assessed. Discussion. This study aims to assess the presence or absence of TNF- alpha expression in the ECF tissue in non-IBD origin. If our hypothesis is correct we would then be able to study the use of the TNF- alpha inhibitor Infliximab as a therapeutic option in the treatment of non-IBD ECF. Secondary aims include assessing the spectrum of inflammatory cytokines and markers present in tissue and serum of non-IBD ECF when compared with IBD ECF and normal controls. © 2011 Rahbour et al; licensee BioMed Central Ltd.
    • Sexual dimorphism in the acute effects of secondhand smoke on thyroid hormone secretion, inflammatory markers and vascular function.

      Flouris, Andreas D.; Metsios, Giorgos S.; Jamurtas, Athanasios Z.; Koutedakis, Yiannis (American Physiological Society, 2008)
      Experimental evidence for the physiological effects of secondhand smoke (SHS) is limited, although it affects millions of people globally and its prevalence is increasing, despite currently adopted antismoking measures. Also, scarce evidence suggests that the effects of SHS may be more pronounced in men. We conducted a randomized single-blind crossover study to investigate the sex-specific SHS effects in a controlled simulated bar/restaurant environment on gonadal and thyroid hormones, inflammatory cytokines, and vascular function. Twenty-eight (women = 14) nonsmoking adults underwent a 1-h exposure to moderate SHS and a 1-h control trial. Serum and urine cotinine, gonadal and thyroid hormones, inflammatory cytokines, heart rate, and arterial blood pressure were assessed before exposure and immediately after in both trials. Results showed that testosterone (P = 0.019) and progesterone (P < 0.001) in men and 17beta-estradiol (P = 0.001) and progesterone (P < 0.001) in women were significantly decreased after SHS. In men, SHS was accompanied by increased free thyroxine (P < 0.001), triiodothyronine (P = 0.020), and decreased the triiodothyronine-to-free thyroxine ratio (P = 0.033). In women, significant SHS-induced change was observed only in free thyroxine (P = 0.010), with considerable sex variation in free thyroxine and triiodothyronine and a decrease in luteinizing hormone (P = 0.026) and follicle-stimulating hormone (P < 0.001). After SHS, IL-1beta (P = 0.001) and systolic blood pressure (P = 0.040) were increased in men but not women. We concluded that a 1-h SHS exposure at bar/restaurant levels is accompanied by decrements in gonadal hormones in both sexes and marked increases in thyroid hormone secretion, IL-1beta production, and systolic blood pressure in men.
    • The hepatitis B virus X protein activates nuclear factor of activated T cells (NF-AT) by a cyclosporin A-sensitive pathway.

      Lara-Pezzi, Enrique; Armesilla, Angel; Majano, Pedro L.; Redondo, Juan Miguel; López-Cabrera, Manuel (Nature Publishing Group, 1998-12-01)
      The X gene product of the human hepatitis B virus (HBx) is a transcriptional activator of various viral and cellular genes. We recently have determined that the production of tumor necrosis factor-alpha (TNF-alpha) by HBV-infected hepatocytes is transcriptionally up-regulated by HBx, involving nuclear factor of activated T cells (NF-AT)-dependent activation of the TNF-alpha gene promoter. Here we show that HBx activates NF-AT by a cyclosporin A-sensitive mechanism involving dephosphorylation and nuclear translocation of the transcription factor. Luciferase gene expression assays demonstrated that HBx transactivates transcription through NF-AT-binding sites and activates a Gal4-NF-AT chimeric protein. DNA-protein interaction assays revealed that HBx induces the formation of NF-AT-containing DNA-binding complexes. Immunofluorescence analysis demonstrated that HBx induces the nuclear translocation of NF-AT, which can be blocked by the immunosuppressive drug cyclosporin A. Furthermore, immunoblot analysis showed that the HBx-induced activation and translocation of NF-AT are associated with its dephosphorylation. Thus, HBx may play a relevant role in the intrahepatic inflammatory processes by inducing locally the expression of cytokines that are regulated by NF-AT.