Showing papers by "Frank Buttgereit published in 2013"

EULAR evidence-based and consensus-based recommendations on the management of medium to high-dose glucocorticoid therapy in rheumatic diseases

Abstract: To develop recommendations for the management of medium to high-dose (ie, >7.5 mg but ≤100 mg prednisone equivalent daily) systemic glucocorticoid (GC) therapy in rheumatic diseases. A multidisciplinary EULAR task force was formed, including rheumatic patients. After discussing the results of a general initial search on risks of GC therapy, each participant contributed 10 propositions on key clinical topics concerning the safe use of medium to high-dose GCs. The final recommendations were selected via a Delphi consensus approach. A systematic literature search of PubMed, EMBASE and Cochrane Library was used to identify evidence concerning each of the propositions. The strength of recommendation was given according to research evidence, clinical expertise and patient preference. The 10 propositions regarded patient education and informing general practitioners, preventive measures for osteoporosis, optimal GC starting dosages, risk-benefit ratio of GC treatment, GC sparing therapy, screening for comorbidity, and monitoring for adverse effects. In general, evidence supporting the recommendations proved to be surprisingly weak. One of the recommendations was rejected, because of conflicting literature data. Nine final recommendations for the management of medium to high-dose systemic GC therapy in rheumatic diseases were selected and evaluated with their strengths of recommendations. Robust evidence was often lacking; a research agenda was created.

Induction therapy with adalimumab plus methotrexate for 24 weeks followed by methotrexate monotherapy up to week 48 versus methotrexate therapy alone for DMARD-naïve patients with early rheumatoid arthritis: HIT HARD, an investigator-initiated study

Abstract: Objective To investigate the long-term effects of induction therapy with adalimumab (ADA) plus methotrexate (MTX) in comparison with placebo (PBO) plus MTX in DMARD-naive patients with active early rheumatoid arthritis (RA). Methods Patients with active early RA (disease duration of ≤12 months) were randomly assigned to receive 40 mg ADA subcutaneously every other week (eow) plus MTX 15 mg/week subcutaneously or PBO plus MTX subcutaneously at 15 mg/week over 24 weeks. Thereafter, all patients received MTX monotherapy up to week 48. The primary outcome was the Disease Activity Score 28 (DAS28) at week 48. Secondary outcomes included proportions of patients in remission (DAS28<2.6), ACR responses, Health Assessment Questionnaire (HAQ) score and radiographic progression. Results 87 patients were assigned to ADA/MTX and 85 patients to PBO/MTX. At baseline, DAS28 was 6.2 ±0.8 in the ADA/MTX and 6.3±0.9 in the PBO/MTX groups. At week 24, treatment with ADA/MTX compared with PBO/MTX resulted in a greater

Low-dose prednisone chronotherapy for rheumatoid arthritis: a randomised clinical trial (CAPRA-2)

Abstract: Objective To assess the effi cacy and safety of low-dose prednisone chronotherapy using a new modifi ed-release (MR) formulation for the treatment of rheumatoid arthritis (RA) Methods In this 12-week, double-blind, placebocontrolled study, patients with active RA (n=350) were randomised 2:1 to receive MR prednisone 5 mg or placebo once daily in the evening in addition to their existing RA disease-modifying antirheumatic drug (DMARD) treatment The primary end point was the percentage of patients achieving a 20% improvement in RA signs and symptoms according to American College of Rheumatology criteria (ie, an ACR20 response) at week 12 Changes in morning pain, duration of morning stiffness, 28-joint Disease Activity Score and healthrelated quality of life were also assessed Results MR prednisone plus DMARD treatment produced higher response rates for ACR20 (48% vs 29%, p<0001) and ACR50 (22% vs 10%, p<0006) and a greater median relative reduction from baseline in morning stiffness (55% vs 35%, p<0002) at week 12 than placebo plus DMARD treatment Signifi cantly greater reductions in severity of RA (Disease Activity Score 28) (p<0001) and fatigue (Functional Assessment of Chronic Illness Therapy-Fatigue score) (p=0003) as well as a greater improvement in physical function (36-item ShortForm Health Survey score) (p<0001) were seen at week 12 for MR prednisone versus placebo The incidence of adverse events was similar for MR prednisone (43%) and placebo (49%) Conclusion Low-dose MR prednisone added to existing DMARD treatment produced rapid and relevant improvements in RA signs and symptoms ClinicalTrialsgov, number NCT00650078

Osteoarthritis synovial fluid activates pro-inflammatory cytokines in primary human chondrocytes

Abstract: Purpose Two of the most common joint diseases are rheumatoid arthritis (RA) and osteoarthritis (OA). Cartilage degradation and erosions are important pathogenetic mechanisms in both joint diseases and have presently gained increasing interest. The aim of the present study was to investigate the effects of the synovial fluid environment of OA patients in comparison with synovial fluids of RA patients on human chondrocytes in vitro.

Human immune cells' behavior and survival under bioenergetically restricted conditions in an in vitro fracture hematoma model

Abstract: The initial inflammatory phase of bone fracture healing represents a critical step for the outcome of the healing process. However, both the mechanisms initiating this inflammatory phase and the function of immune cells present at the fracture site are poorly understood. In order to study the early events within a fracture hematoma, we established an in vitro fracture hematoma model: we cultured hematomas forming during an osteotomy (artificial bone fracture) of the femur during total hip arthroplasty (THA) in vitro under bioenergetically controlled conditions. This model allowed us to monitor immune cell populations, cell survival and cytokine expression during the early phase following a fracture. Moreover, this model enabled us to change the bioenergetical conditions in order to mimic the in vivo situation, which is assumed to be characterized by hypoxia and restricted amounts of nutrients. Using this model, we found that immune cells adapt to hypoxia via the expression of angiogenic factors, chemoattractants and pro-inflammatory molecules. In addition, combined restriction of oxygen and nutrient supply enhanced the selective survival of lymphocytes in comparison with that of myeloid derived cells (i.e., neutrophils). Of note, non-restricted bioenergetical conditions did not show any similar effects regarding cytokine expression and/or different survival rates of immune cell subsets. In conclusion, we found that the bioenergetical conditions are among the crucial factors inducing the initial inflammatory phase of fracture healing and are thus a critical step for influencing survival and function of immune cells in the early fracture hematoma.

Pathophysiological hypoxia affects the redox state and IL-2 signalling of human CD4+ T cells and concomitantly impairs survival and proliferation

Abstract: Inflamed areas are characterized by infiltration of immune cells, local hypoxia and alterations of cellular redox states. We investigated the impact of hypoxia on survival, proliferation, cytokine secretion, intracellular energy and redox state of human CD4+ T cells. We found that pathophysiological hypoxia (<2% O2) significantly decreased CD4+ T-cell survival after mitogenic stimulation. This effect was not due to an increased caspase-3/7-mediated apoptosis or adenosine-5′-triphosphate (ATP) consumption/depletion. However, the ability of stimulated T cells to proliferate was reduced under hypoxic conditions, despite increased expression of CD25. Pathophysiological hypoxia was also found to modify intracellular ROS (iROS) levels in stimulated T cells over time as compared with levels found in normoxia. Physiological hypoxia (5% O2) did not decrease CD4+ T-cell survival and proliferation or modify iROS levels as compared with normoxia. We conclude that pathophysiological hypoxia affects T-cell proliferation and viability via disturbed IL-2R signalling downstream of STAT5a phosphorylation, but not as a result of impaired cellular energy homeostasis. We suggest iROS links early events in T-cell stimulation to the inhibition of the lymphoproliferative response under pathophysiological hypoxic conditions. The level of iROS may therefore act as a mediator of immune functions leading to down-regulation of long-term T-cell activity in inflamed tissues.

Delayed-release prednisone – a new approach to an old therapy

Abstract: Introduction: Despite the widespread use of glucocorticoid (GC) treatment for inflammatory conditions, there remains a need to optimize use by improving efficacy and/or reducing adverse consequences. The most advanced approach, already licensed for clinical use, is delayed-release prednisone. Areas covered: Delayed-release prednisone consists of an inert outer coat containing an inner core of active drug (1, 2, or 5 mg) taken at bedtime (approximately 22:00 h). After a lag time of 4 – 6 h, the coat opens to release prednisone, at the appropriate time to counteract elevated nocturnal levels of pro-inflammatory cytokines associated with the circadian pattern of symptoms seen in rheumatoid arthritis (RA) and other inflammatory conditions. Clinical trials in RA have demonstrated the improved efficacy of delayed-release prednisone with respect to morning stiffness compared with conventional immediate-release prednisone tablets taken in the morning and compared with placebo in patients on disease-modifying anti...

Gene expression of catalytic proteasome subunits and resistance toward proteasome inhibition of B lymphocytes from patients with primary sjogren syndrome.

Abstract: Objective. Dysregulation of proteasome subunit β1i expression has been shown in total blood mononuclear cells (PBMC) from patients with primary Sjogren syndrome (pSS), a B cell-driven systemic autoimmune disorder. Methods. Proteasome activation was investigated in sorted blood cells from patients with pSS and controls by measuring transcript levels of constitutive (β1/β2/β5) and corresponding immunoproteasome catalytic subunits (β1i/β2i/β5i) using real-time PCR. At protein level, β1i protein expression was analyzed by immunoblotting. Functional effects of proteasome inhibition on proteolytic activity and induction of apoptosis were also evaluated in cellular subsets. Results. The proteasome was found to be activated in pSS, with upregulation of gene expression of catalytic proteasome subunits. Western blot analysis revealed decreased β1i protein expression in pSS B lymphocytes, with decreased protein despite increased messenger RNA (mRNA) levels. After proteasome inhibition in vitro , proteolytic activity was less reduced and resistance to apoptosis was increased in B lymphocytes compared to other cells. Conclusion. In pSS, catalytic subunits of the proteasome are upregulated at the mRNA level, while dysregulation of subunit β1i is attributed to B lymphocytes. B cell resistance after proteasome inhibition differs from the classical concept of increased susceptibility toward inhibition in activated cells, supporting the novel notion that susceptibility depends on cellular intrinsic factors and on proteasome activation.

High-Sensitivity Immunofluorescence Staining: A Comparison of the Liposome Procedure and the FASER Technique on mGR Detection

Abstract: Flow cytometry has become a widely-used and powerful tool for the characterization of cells according to their expression of specific proteins. However, sensitivity of this method is still limited since conventionally labeled antibodies can be conjugated with at maximum 1–10 dye molecules. This fact resulted in the need to develop new techniques in order to identify molecules which are expressed in very low but functionally relevant amounts. In the past, we have successfully used a liposome-based high-sensitivity immunofluorescence technique to measure the expression of low abundant membrane bound glucocorticoid receptors (mGR) on different cell types. The use of this technique allows the detection of as few as 50–100 antigen molecules per cell which is due to a 100-fold to 1000-fold increase in fluorescence signal intensity compared with conventional methods. The higher sensitivity is achieved since thousands of dye molecules can be enclosed in liposomes. Another modern high-sensitivity immunofluorescence staining method is the purchasable Fluorescence Amplification by Sequential Employment of Reagents (FASER) procedure. Here, we aimed at comparing sensitivity and specificity of these two techniques for the detection of the mGR. Our data demonstrate the FASER technique to be more sensitive and also more specific for the detection of mGR as compared to the liposome technique. However, both methods have advantages and disadvantages which are discussed in detail.

OP0145 Induction therapy with adalimumab plus methotrexate versus methotrexate monotherapy in recent onset rheumatoid arthritis (RA) – an investigator initiated randomized controlled trial

Abstract: Background To study the prolonged effect on disease activity by an early induction therapy with adalimumab (ADA) plus methotrexate (MTX) versus MTX alone in DMARD naive patients (pts) with early RA (designated HIT HARD, funded by the German Ministry of Science). Methods In a double-blind randomized controlled trial, RA pts (disease duration of ≤12 months, ≥6 swollen, ≥6 tender joints, and CRP≥10 mg/l) were randomized into two groups: placebo (PBO) plus MTX (n=85), given s.c. at 15 mg/week (w) versus MTX 15 mg/w s.c. plus 40 mg ADA s.c. eow over 24w (n=87). After w24, both groups were treated only with MTX up to w48. The primary outcome measure was the DAS28-response at w48. Secondary outcomes was the pts in remission (DAS28 Results Mean disease duration at BL was 1.7 years, 91 (53%) were ACPA positive and 114 (63%) IgM RF positive. DAS28 was 6.2±0.8 (ADA/MTX) and 6.3±0.9 (PBO/MTX) (p=0.60). Outcome parameters at w24 and w48 are presented in tables 1. During the induction phase, ADA/MTX reduced disease activity to a significantly greater extent than PBO/MTX (Table 1). After termination of ADA or PBO and continuation with MTX alone, the differences between both groups in clinical outcome parameters (DAS28, remission, ACR50 response, HAQ, SF36 mental score) decreased at w24/48 and did not reach statistical significance at w48. Nevertheless, combination therapy significantly reduced radiographic progression as demonstrated by the Sharp vdH erosion score (p=0.010) as compared to the combination group, joint space narrowing score (p=0.035) and Sharp vdH total score (p=0.003); Ratingen score (p=0.012) compared to MTX alone when analyzed after w48. Conclusions Superiority in reduction of radiographic progression after initial combination therapy with ADA and MTX was seen at w 48, even after discontinuation of ADA treatment at w 24. Such a sustained effect was not found regarding the primary endpoint (DAS28 reduction). Disclosure of Interest J. Detert Grant/Research support from: Abbott & Co GmbH, Speakers Bureau: Abbott & Co GmbH, H. Bastian Speakers Bureau: Abbott & Co GmbH, J. Listing: None Declared, A. Weiss: None Declared, S. Wassenberg: None Declared, A. Liebhaber: None Declared, K. Rockwitz: None Declared, R. Alten: None Declared, K. Kruger: None Declared, R. Rau: None Declared, C. Simon: None Declared, E. Gremmelsbacher: None Declared, T. Braun: None Declared, B. Marsmann: None Declared, V. Hohne-Zimmer: None Declared, K. Egerer: None Declared, F. Buttgereit: None Declared, G.-R. Burmester Grant/Research support from: Abbott & Co GmbH, Consultant for: Abbott & Co GmbH, Speakers Bureau: Abbott & Co GmbH

EULAR evidence-based recommendations on the management of medium to high dose systemic glucocorticoid therapy in rheumatic diseases

Abstract: Objectives To develop recommendations for the management of medium to high dose systemic glucocorticoid (GC) therapy in rheumatic diseases. Methods A multidisciplinary EULAR task force was formed, comprising of 8 rheumatologists, 1 endocrinologist, 1 rheumatologist–epidemiologist, 4 patients and 2 research fellows from 7 European countries. Each participant contributed 10 propositions describing key clinical points concerning the safe use of medium to high dose GCs. The final recommendations were developed using a Delphi consensus approach and the wording was improved by a native speaker. A systematic literature search of PUBMED, EMBASE and Cochrane Library was used to identify the best available research evidence to support each of the propositions. The strength of recommendation was given according to research evidence, clinical expertise and patient preference. Results The 10 final propositions included the topics patient education and informing general practitioners, preventive measures for osteoporosis, optimal GC starting dosages, risk-benefit ratio of GC treatment, GC sparing therapy, screening for co morbidity, and monitoring for adverse events. Most of the propositions were only indirectly supported by evidence from literature. The strength of each recommendation differed according to the level of evidence and clinical expertise, but was generally low because available literature on medium to high dose GC therapy was limited. Conclusions Ten recommendations for the management of medium to high dose systemic GC therapy in rheumatic diseases were formulated, and strengths of recommendation were provided. Robust evidence was often lacking and items in need for further research were defined. Disclosure of Interest None Declared

OP0086 Alterations of immune cellular circadian rhythms in rheumatoid arthritis

Abstract: Background The circadian variation of clinical symptoms and the underlying variation of cytokine and hormone levels in rheumatoid arthritis (RA) are well described and have already led to the successful application of chronotherapy with prednisone (Buttgereit et al., Lancet, 2008). Much less is known about the circadian rhythms of different immune cell populations in RA. Objectives In this pilot study we investigated molecular, cellular and humoral circadian parameters in postmenopausal female RA patients in comparison to healthy control subjects. Methods Blood samples from postmenopausal female patients with active RA (DAS 28 ≥4.2) (n=5) and postmenopausal female healthy controls (n=5) were collected every 2 hours for 24 hours and analysed by flow cytometry and multiplex suspension array of 28 cytokines. Clock gene expression of isolated CD14+ monocytes was analysed by quantitative RT-PCR. Endogenous circadian rhythm dynamics of macrophages were determined by means of a Bmal1 -promotor driven luciferase reporter construct. COSINOR analysis was used for statistical analysis of the groups. Results Expression of the clock gene RevErbα in CD14+ monocytes showed a significant circadian expression pattern in both RA patients and healthy controls subjects, whereas the clock genes Per2 and Per3 were not expressed in a circadian manner in RA patients but in healthy controls only. The amplitude of the endogenous circadian rhythm of macrophages tended to be lower in RA patients than in healthy controls, whereas period length was not altered. In flow cytometric analysis of surface marker expression of blood cells we found a significant circadian rhythm in RA patients and healthy subjects for the frequency of CD3-CD56+ natural killer (NK) cells, Interleukin-8 Receptor (IL-8R) expressing CD4+ T helper and CD8+ cytotoxic T cells , and CXCR4 expressing CD4+ T helper and CD8+ cytotoxic cells . A significant circadian rhythm was not detectable in RA patients but in healthy controls only for CD3+CD56+ NK T cells . In contrast, a significant circadian expression of IL-8R+ monocytes was found in RA patients only but not in healthy subjects. Of note, CCR7 did not at all show a circadian expression. A significant circadian cytokine expression was detected only for MCP-1 in healthy controls. Conclusions This is the first indication of alterations of clock gene expression and endogenous circadian rhythms in immune cells of RA patients. Traffic of peripheral blood cells shows circadian variation in RA patients and healthy controls with characteristic peak phases, especially in NK cells and chemokine receptor expressing cells. NKT and other cells may lose their normal circadian rhythm in RA, whereas IL-8R expression on monocytes may be established as new “inflammatory” circadian rhythm in RA patients. These findings provide new aspects of RA chronobiology and may have therapeutic implications. Disclosure of Interest C. Spies: None Declared, T. Gaber: None Declared, P. Hoff: None Declared, J. Mazuch: None Declared, B. Maier: None Declared, M. Hahne: None Declared, C. Strehl: None Declared, C. Tran: None Declared, N. Soboleva: None Declared, A. Stoehr: None Declared, M. Wagegg: None Declared, M. Fangradt: None Declared, M. Jakstadt: None Declared, D. Huscher: None Declared, G.-R. Burmester: None Declared, J. Detert: None Declared, A. Kramer: None Declared, F. Buttgereit Grant/Research support from: This study was supported by Horizon Pharma AG, Reinach, Switzerland and Merck KGaA, Darmstadt, Germany. Dr. Buttgereit reports receiving consultancy fees, honoraria and travel expenses from Merck Serono, Horizon Pharma (formerly Nitec Pharma) Mundipharma Int Ltd and grant support from Merck Serono and Horizon Pharma., Consultant for: see above, Speakers Bureau: see above

and Fyn Rapid immunosuppressive effects of glucocorticoids mediated through Lck

Abstract: Glucocorticoids (GCs) are effective immunosuppressive agents and mediate well-defined transcriptional effects via GC-receptors. There is increasing evidence that GCs also initiate rapid nongenomic signaling events. Employing activated human CD4 + lymphocytes and a peptide array containing 1176 different kinase consensus substrates, we generated a comprehensive profile of GC-induced rapid effects on signal transduction. The results show marked early differences in phosphorylation between GC-pretreated cells and control cells including impaired phosphorylation of Lck/Fyn-consensus substrates. Immunoprecipitation and in vitro kinase assays reveal rapid GC-induced down-modulation of Lck and Fyn kinases employing SAM68 as a substrate. Additionally, immunoprecipitation-experiments revealed reduced Lck-CD4 and Fyn-CD3 associations suggesting GC inhibited recruitment of these kinases to the T cell receptor complex. Western blot analysis revealed reduced phosphorylation of a series of downstream signaling intermediates following GC-treatment, including PKB, PKC and MAPKs. Experiments with GC-receptor negative Jurkat cells and a pharmacological GC-receptor ligand (RU486)indicated that rapid inhibition of Lck and Fyn kinases is GC-receptor dependent. Parallelexperiments conducted following the application of GCs in healthy individuals confirmed suppression of Lck/ Fyn in T cells within 1 hr

FRI0541 Influence of rheumatoid arthritis-related morning stiffness on productivity at work: results from a survey in 11 european countries

Abstract: Background RA has a substantial societal effect in terms of costs, disability and lost productivity, with much of the costs occurring outside the healthcare system (1,2). However, the calculatedcosts of RA vary considerably depending on countries studied and methods used (3). Objectives The objective of this study wasto evaluate the influence of morning stiffness on productivity at work and to estimate the work-related economic consequences of morning stiffness in 11 European countries. Methods The original sample comprised 1061 RA patients from 11 European countries (Belgium, Denmark, Finland, France, Germany, Italy, Norway, Poland, Spain, Sweden and UK). They had symptoms of morning stiffness for more than six months, three or more times per week. Data were collected by interviews using a structured questionnaire translated into local languages. Women comprised 77.9% of the sample, the average age was 50.4 years and 84.3% had RA diagnosed for more than 2 years. Based on the average working time in EU countries (4) in all time-based cost estimates the numbers of active working hours per year was estimated to be 1568. The annual level of gross income reported by the patients was used to obtain individual time-based cost estimates. Results Overall costs of RA-related morning stiffness was calculated to be 27712€ per patient per year, varying from 4965€ in Spain to 66706€ in Norway. On average 96% (77-99%) of the overall production losses were attributed to early retirement, with a markedly lower level (77%) in Italy than in other countries (p Conclusions Morning stiffness due to RA causes significant production losses and is a significant cost burden throughout Europe. There seem to be notable differences in the impact of morning stiffness on productivity between European countries. References Kobelt G, Jonsson B. The burden of rheumatoid arthritis and access to treatment: outcome and cost-utility of treatments. Eur J Healh Econ 2008;8 (Suppl 2):S95-S106. Merkersdal S, Ruof J, Huelsemann J et al. Development of a matrix of cost domains in economic evaluation of rheumatoid arthritis. J Rheumatol 2001;28:657-661. Lundqkvist J, Kastang F, Kobelt G. The burden of rheumatoid arthritis and access to treatment: health burden and costs. Eur J Health Econ 2008; 8 (Suppl2):S49-S60. Eurostat yearbook 2011. http://epp.eurostat.ec.europa.eu/portal/page/portal/product_details/publication?p_product_code=CH_06_2011 / accessed 25.10.2012. Acknowledgements The survey was conducted by Ipsos MORI and sponsored by an educational grant from Mundipharma International Limited. Disclosure of Interest K. Mattila: None Declared, F. Buttgereit Grant/research support from: Merck Serono & Horizon Pharma, Consultant for: Merck Serono, Horizon Pharma (formerly Nitec Pharma) & Mundipharma International Limited, Speakers bureau: Mundipharma International Limited, R. Tuominen Consultant for: Mundipharma International Limited, Speakers bureau: Mundipharma International Limited

OP0271 Differential regulatory functions of HIF-1α and HIF-2α during angiogenesis of human microvascular endothelial cells (HMECS)

Abstract: Background Hypoxia and angiogenesis are features of inflamed and injured tissues. The transcription factors Hypoxia inducible factor (HIF)-1α and (HIF)-2α control cellular metabolic response to decreased oxygen tension thereby promoting angiogenesis and having implications on the pathogenesis of RA. Objectives We focused on the effects of HIF-1α and HIF-2α on angiogenesis and developed a human microvascular endothelial cells (HMEC) lentiviral based knockdown system for both transcription factors allowing us to analyze angiogenesis of HMECs under hypoxia in the absence of HIF-1α or HIF-2α, respectively. Methods Specific knockdown of HIF-1α or HIF-2α was achieved using lentiviral-based shRNA technology. The reduction of HIF-1α or HIF-2α was confirmed on transcriptional and translational level by realtime RT-PCR and Western blot. Angiogenesis of transduced HMECs in comparison to scrambled cells was studied by investigating both tubuli and node formation under hypoxia ( 2 ). Expression of hypoxia driven genes HIF1A , HIF2A , VEGFA and IL8 was quantified by realtime RT-PCR. Multiplex suspension array technology was used to measure the concentrations of secreted VEGF and IL8. Results The successful knockdown of HIF-1α and HIF-2α was confirmed by demonstrating considerably reduced gene expression levels of HIF1A and HIF2A by up to 71% (p=0.0222) under normoxic and hypoxic conditions. As a consequence, strongly reduced HIF-1α and HIF-2α protein levels were detected by Western blot. Targeting of HIF-1α led to a significantly decreased node formation (1.6-fold change under hypoxia, p=0.0067) with similar effects by trend on tubuli formation. The HIF-2α knockdown also led to a significantly decreased tubuli formation (1.7-fold change, p=0.0444) with similar effects by trend on node formation. Furthermore, HIF-1α targeted cells did not show any significant decrease in the gene expressions of VEGFA and IL8 but surprisingly raised cytokine levels of IL8 under hypoxia (1.4-fold change, p=0.021) compared to the control. In contrast, targeting of HIF-2α gave rise to reduced levels of secreted VEGF and IL8 with a significant suppression of IL8 gene expression under normoxia (2.1-fold change, p=0.0101). Conclusions Our findings show essential and overlapping functions of HIF-1α and HIF-2α with regard to their regulatory potential of angiogenesis in HMECs. Both transcription factors have the same impact on VEGF but differ in their effects on IL8 expression. These findings provide new insights into basic principles of angiogenesis in inflamed tissues and are therefore considered to be of clinical importance. Disclosure of Interest None Declared