Hypoxia increases atorvastatin-induced decay-accelerating factor expression

<p><b>Copyright information:</b></p><p>Taken from "Statin-induced expression of CD59 on vascular endothelium in hypoxia: a potential mechanism for the anti-inflammatory actions of statins in rheumatoid arthritis"</p><p>Arthritis Research & Therapy 2006;8(4):R130-R130.</p><p>Published online 21 Jul 2006</p><p>PMCID:PMC1779384.</p><p></p> Analysis of decay-accelerating factor expression on human umbilical vein endothelial cells (HUVEC) following 48 hours culture in 21% O(open bars) or 1% O(filled bars) in the presence or absence of atorvastatin (0.25 μM). and HUVEC were treated with increasing concentrations of atorvastatin for 48 hours in the presence (filled bars) or absence (open bars) of (b) cobalt chloride (CoCl) (100 μM) or (c) desferrioxamine (DFO) (100 μM). Decay-accelerating factor expression was measured by flow cytometry using the mAb 1H4. Bars represent the mean ± standard error of the mean (= 4). *< 0.05, **< 0.01 compared with untreated controls

Atorvastatin-induced CD59 and decay-accelerating factor in hypoxia enhance endothelial cell cytoprotection

<p><b>Copyright information:</b></p><p>Taken from "Statin-induced expression of CD59 on vascular endothelium in hypoxia: a potential mechanism for the anti-inflammatory actions of statins in rheumatoid arthritis"</p><p>Arthritis Research & Therapy 2006;8(4):R130-R130.</p><p>Published online 21 Jul 2006</p><p>PMCID:PMC1779384.</p><p></p> Human umbilical vein endothelial cells (HUVEC) were cultured under normoxic or hypoxic conditions with and without atorvastatin (0.25 μM) for 48 hours followed by 3 hours reoxygenation. Harvested endothelial cells (EC) were incubated with 20% C5-deficient (C5 D) serum (filled bars) or heat-inactivated (HI) normal human serum (NHS) (open bars) for 2 hours. C3 binding was analysed by flow cytometry and results are expressed as the percentage of C3 binding relative to that on EC exposed to C5 D in normoxia (shown as 100%). *< 0.05 (= 4), difference between levels of cell surface C3 deposition on EC cultured under hypoxic conditions in the presence or absence of atorvastatin HUVEC were cultured under normoxic or hypoxic conditions with and without atorvastatin (0.5 μM) for 48 hours followed by 3 hours of reoxygenation. C9 binding was analysed by flow cytometry following incubation with 20% NHS (filled bars) or HI serum (open bars). Results are expressed as the percentage of C9 binding relative to that on EC exposed to NHS in normoxia (shown as 100%). *< 0.05 (= 4), difference between statin-treated and untreated EC in hypoxia.HUVEC were incubated in 1% Owith or without atorvastatin (At) 0.5 μM for 48 hours followed by 3 hours of reoxygenation. EC were preincubated with the inhibitory mAbs Bric229 (CD59) and 1H4 (decay-accelerating factor) (20 μg/ml) or veronal buffered saline + 1% gelatin at 4°C. EC were then incubated with 20% rabbit serum or 20% HI rabbit serum at 37°C for 1 hour and propidium iodide (PI) was added prior to analysis by flow cytometry. The percentage EC lysis was calculated as the number of PI-positive cells expressed as a percentage of the total number of cells. **< 0.001 (= 4), difference between statin-treated and untreated EC

Mechanisms involved in atorvastatin-induced decay-accelerating factor expression

<p><b>Copyright information:</b></p><p>Taken from "Statin-induced expression of CD59 on vascular endothelium in hypoxia: a potential mechanism for the anti-inflammatory actions of statins in rheumatoid arthritis"</p><p>Arthritis Research & Therapy 2006;8(4):R130-R130.</p><p>Published online 21 Jul 2006</p><p>PMCID:PMC1779384.</p><p></p> Human umbilical vein endothelial cells (HUVEC) were cultured for 48 hours under hypoxia (1% O) and were treated with atorvastatin (At) (0.5 μM) in the presence or absence of mevalonate (200 μM), -monomethyl-L-arginine (L-NMMA) (500 μM), -nitro-L-arginine methyl ester (L-NAME) (100 μM) and geranylgeraniol (GGOH) (20 μM). Endothelial cell CD59 expression was measured by flow cytometry using the mAb BRIC 229. Results are expressed as the percentage increase in relative fluorescence intensity above the hypoxic control (US) (= 4). *< 0.5, **< 0.01 compared with untreated controls

Sensitivities to Hypoxia for Individual Participants

<p>Results are shown in terms of the number of (normal control group) standard deviations by which each participant's response differed from the mean response of the normal control participants. The patients with CP were significantly different from the normal control group in their ventilatory and pulmonary vascular responses to both mild and moderate hypoxia, and in their heart rate responses to mild hypoxia. BP, blood pressure.</p

Aldolase C and <i>VEGF</i> mRNA Expression at Different Oxygen Tensions

<p>Lymphocytes were isolated from venous blood taken from CP patients and normal control participants, and incubated at eight different levels of oxygen tension prior to RNA isolation. Gene expression is shown relative to a standard calibrator sample. Basal gene expression at 20% oxygen was significantly higher in CP patients for both <i>Aldolase C</i> (A) and <i>VEGF</i> (B) ( <i>p</i> < 0.05). Both genes were induced by hypoxia, and at the lowest oxygen tension (0.1%) expression was no longer significantly different for either gene. Values are mean ± standard error of the mean. Asterisks indicate <i>p</i> < 0.05 (unpaired <i>t</i>-test). </p

End-Tidal Gas Control, Ventilatory, and Pulmonary Vascular Responses to Mild and Moderate Hypoxia

<div><p>(A and B) End-tidal gas control. </p><p>Pet_O₂</p> and Pet_CO₂ were well controlled. <p>Pet_O₂</p> was well matched between all groups. Pet_CO₂ was lower in the CP patient group, reflecting this group's lower baseline air-breathing Pet_CO₂. <p></p> <p>(C and D) Ventilation, given at body temperature and pressure, saturated with water vapour. Mild hypoxia provoked an increase in ventilation of 4.4 l/min in the CP patients versus 1.6 l/min in normal controls ( <i>p</i> < 0.05), while moderate hypoxia induced increases of 24.5 versus 10.0 l/min in these two groups, respectively ( <i>p</i> < 0.05). </p> <p>(E and F) Pulmonary vascular tone. This was assessed using Doppler echocardiography to determine ΔP_max, a standard non-invasive index of pulmonary vascular tone. With mild hypoxia, ΔP_max increased by 11.5 mm Hg in the CP patient group compared with only 1.1 mm Hg in the normal control group ( <i>p</i> < 0.05). Moderate hypoxia stimulated a rise in ΔP_max of 35.3 mm Hg compared with 6.1 mm Hg in these two groups, respectively ( <i>p</i> < 0.001). </p> <p>All responses are shown during mild (A, C, and E) and moderate (B, D, and F) hypoxia. Values are mean ± standard error of the mean.</p></div

Systemic Vascular Responses to Mild and Moderate Hypoxia

<div><p>(A and B) Heart rate. Mild hypoxia provoked a rise of 11.7 beats/min in the CP patient group, compared with 3.6 beats/min in normal control participants ( <i>p</i> < 0.05). No other statistically significant differences in systemic vascular responses were detected between these two groups. </p> <p>(C and D) Blood pressure, showing systolic pressure (upper plot) and diastolic pressure (lower plot).</p> <p>(E and F) Cardiac output, assessed non-invasively using Doppler echocardiography.</p> <p>All responses are shown during mild (A, C, and E) and moderate (B, D, and F) hypoxia. Values are mean ± standard error of the mean.</p></div