Multilateralismus im Hohen Norden: Die Ukrainekrise droht, die Arktisdiplomatie zu versicherheitlichen

Im April dieses Jahres übergab Kanada den Vorsitz des Arktischen Rates an die USA; in der Arktis waren diese bislang kein starker Akteur. Doch gerade jetzt gefährdet die Ukrainekrise die bisher gut funktionierende internationale Zusammenarbeit mit Russland in der Arktis. Gleichzeitig ist angesichts signifikanter umweltpolitischer Herausforderungen und der steigenden wirtschaftlichen Relevanz des Hohen Nordens multilaterale Zusammenarbeit in der Region wichtiger denn je - es gilt sicherzustellen, dass diplomatische Lösungen auch in Zukunft möglich sein werden

Functional characterization of sEpoR.

<p><b>3a.</b> Western blot showing increasedphospho-Stat-5 in the presence of increasing erythropoietin (25 to 5000 mU/ml) in BaF3/EpoR cell lysates. <b>3b</b>. Representative western blot showing total phospho-Stat-5 and Stat-5 in the presence of erythropoietin 5000 mU/ml and varying concentrations of recombinant sEpoR-Fc (50 -5000 ng/ml). Phospho-Stat-5 decreases with increasing recombinant sEpoR. <b>3c</b>. Quantification of sEpoR-Fc inhibition of phospho-Stat 5 (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0009246#pone-0009246-g003" target="_blank">Figure 3b</a>). Ratios of phospho/total Stat-5 (mean ± SD, n = 3) represented as a percentage of control (Epo alone). *represents p<0.05. <b>3d</b>. Serum from patients with high sEpoR blocks erythropoietin mediated Stat-5 phosphorylation. Shown is the ratio of phospho-Stat-5 to Stat-5 as measured by densitometry. Serum starved BaF3/EpoR cells were exposed to vehicle (negative control), erythropoietin at 50 mU/ml (positive control) and erythropoietin plus 10% serum with Low sEpoR (≤62.5 pg/ml) or serum with high sEpoR (≥4000 pg/ml) for 10 minutes. Cells were lysed in RIPA buffer and 10 ug protein/lane was run on a 4-12% denaturing gel. Gels were transferred and blotted with anti-Stat-5 and anti-phospho-Stat 5. <b>3e</b>. Quantification of western data (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0009246#pone-0009246-g003" target="_blank">Figure 3d</a>). Ratios of phospho/total Stat-5 (mean ± SD, n = 5 individual patient samples each for low sEpoR and high sEpoR) represented as a percentage of control (Epo alone). *represents p<0.05.</p

sEpoR characterization in uremic serum.

<p><b>1a</b>. Soluble EpoR is detectable in serum from dialysis patients by western blot. Human serum was subjected to immunoprecipitation with goat anti-human erythropoietin receptor antibody (R&D Systems, AF-322-PB) followed by western blotting with mouse monoclonal anti-human erythropoietin receptor (R&D Systems, MAB307). Both antibodies recognize the extracellular domain of the receptor. Lanes 1–6 are serum from 6 representative dialysis patients, lane 7 is blank and lane 8 is recombinant sEpoR (Sigma Aldrich E0643, Saint Louis MI). Shown in the serum samples is a band of expected molecular weight of approximately 27 kDa. The control sEpoR with Fc tag is consistent with the manufacturers reported molecular weight of 32 kDa. <b>1b</b>. Soluble EpoR is also detected using the same dialysis patient serum samples by performing immunoprecipitation in reverse order. In this experiment immunoprecipitation was done with mouse monoclonal anti-human erythropoietin receptor (R&D Systems, MAB307) followed by western blotting with goat anti-human erythropoietin receptor (R&D Systems, AF-322-PB). Lanes 1 to 3 are serum from 3 dialysis patients, and lane 4 is recombinant sEpoR-Fc (Sigma, 307) as positive control.</p

sEpoR is regulated by proinflammatory cytokines.

<p><b>4a.</b> IL-6, TNF-α and PMA increase sEpoR in the supernatant of K562 cells. K562 were plated in serum free media and exposed for 48 h to vehicle, PMA, IL-6 and TNF-α. At the end of the incubation cells were pelleted and the supernatant subjected to ELISA for sEpoR. sEpoR measurements were corrected for total protein concentration. * represents p value of <0.05 when compared to the control group. <b>4b.</b> Mean IL-6 levels in subjects with low (n = 32) and high sEpoR (n = 32) are shown. * represents p value of <0.05 when compared to low sEpoR group.</p

Average estimated glomerular filtration rate in patients during and after telaprevir therapy, by baseline kidney function.

<p>3a. Baseline eGFR ≥ 90 mL/min/1.73m² 3b. Baseline eGFR < 90 mL/min/1.73m². Mean eGFR (solid gray circle) and one-standard deviation error bars are shown with shading at baseline, on treatment (nadir), 12 weeks after finishing telaprevir, while still on PegIFN and RBV, and then one year after completing telaprevir, off all treatment. P < 0.01 for changes between baseline eGFR and eGFR while on telaprevir in both groups. There is no signficant difference between baseline eGFR and eGFR 12 weeks or one year post telaprevir. Fig 3a shows patients with baseline eGFR ≥ 90mL/min/1.73m². (N = 44). 3b.) Includes patients with baseline eGFR < 90mL/min/1.73m² (N = 34). Values that fell outside of one standard deviation are shown with hollow gray circles. eGFR = estimated glomerular filtration rate.</p

Peak rise in serum creatinine during telaprevir therapy.

<p>Bar graphs represent the numbers of patients who experienced a maximum rise in serum creatinine in the above ranges. The majority (55%) of patients experienced a small (< 0.2mg/dl) rise in creatinine during telaprevir therapy. However, thirty-one percent developed significant creatinine rise ≥ 0.3mg/dl, shown by a dashed vertical line.</p

Univariate and multivariable linear regression model predicting change in eGFR over one year follow-up.

<p>^{Abbreviations: HIV = human immunodeficiency virus, eGFR = estimated glomerular filtration rate}</p><p>Univariate and multivariable linear regression model predicting change in eGFR over one year follow-up.</p

Timeline of Triple Therapy, Short and Long-term Follow-up.

<p>Patients were prescribed triple therapy (telaprevir, Peg-IFN, and ribavirin) for twelve weeks. Based on clinical characteristics and at the providers discretion patients then continue Peg-IFN and ribavirin for a total of 24–48 weeks. Short-term follow-up was obtained 12 weeks after telaprevir was discontinued (at week 24). Long-term follow-up was obtained 12 months after telaprevir was discontinued (at week 62).</p

Symptoms contributing to the discontinuation of telaprevir (n = 25).

<p>^{Twenty-five patients discontinued telaprevir therapy. Numbers may add up to more than total N if combinations of multiple symptoms led to discontinuation.}</p><p>^{<b>ϕ -</b> Significant at the level of P < 0.05}</p><p>^{*Other reasons for discontinuation that each affected one patient included fever and noncomplicance.}</p><p>Symptoms contributing to the discontinuation of telaprevir (n = 25).</p

Univariate and multivariable logistic regression model predicting development of significant creatinine rise during therapy with telaprevir.

<p>^{Abbreviations: HIV = human immunodeficiency virus, eGFR = estimated glomerular filtration rate}</p><p>Univariate and multivariable logistic regression model predicting development of significant creatinine rise during therapy with telaprevir.</p