Adrecizumab, a non-neutralizing anti-adrenomedullin antibody, improves haemodynamics and attenuates myocardial oxidative stress in septic rats

Abstract

Background: Sepsis still represents a major health issue, with persistent high morbidity and mortality rates. Cardiovascular dysfunction occurs frequently during sepsis. Adrenomedullin has been identified as a key mediator in vascular tone regulation. A non-neutralizing anti-adrenomedullin antibody, Adrecizumab, may improve haemodynamic dysfunction during caecal ligation and puncture-induced septic shock in a murine model. Our objective was to determine the role of Adrecizumab on haemodynamics in a rat model of sepsis.

Methods: For the induction of sepsis, caecal ligation and puncture were performed in Wistar male rats. Single blinded administration of Adrecizumab (2 mg/kg) or placebo was injected i.v. 24 h after the surgery, and norepinephrine was infused as the standard of care. There were > 7 animals per group. Invasive blood pressure and cardiac function (by echocardiography) were assessed until 3 h after Adrecizumab injection.

Results: A single therapeutic injection of Adrecizumab in septic rats induced rapid haemodynamic benefits with an increase in systolic blood pressure in septic-Adrecizumab rats versus untreated-septic rats (p = 0.049). The shortening fraction did not differ between the untreated-septic and septic-Adrecizumab groups. However, cardiac output increased during the 3 h after a single dose of Adrecizumab compared to untreated septic rats (p = 0.006). A single dose of Adrecizumab resulted in similar haemodynamics to the continuous administration of norepinephrine. Three hours after a single injection of Adrecizumab, there was no change in the inflammatory phenotype (TNFα, IL-10) in the hearts of the septic rats. By contrast, 3 h after a single Adrecizumab injection, free-radical production decreased in the hearts of septic-Adrecizumab vs untreated septic rats (p < 0.05).

Conclusions: In a rat model of sepsis, a single therapeutic injection of Adrecizumab rapidly restored haemodynamic parameters and blunted myocardial oxidative stress. Currently, a proof-of-concept and dose-finding phase II trial (Adrenoss-2) is ongoing in patients with septic shock and elevated concentrations of circulating bio-adrenomedullin.

Fig. 1

Experimentation protocol

Fig. 2

Haemodynamic parameters after sepsis induction, until 3 h after the injection of Adrecizumab or placebo. Haemodynamic parameters measured 24 h after sepsis induction by CLP and then 60, 120, and 180 min after the injection of Adrecizumab or placebo. CLP rats are represented by the black line, CLP-Adrecizumab rats by the red line, and CLP-NE rats by the grey line. Two-way ANOVA was used. *p < 0.05

Fig. 3

Effect of Adrecizumab on the adrenomedullin pathway. a Adrenomedullin plasma level (pg / mL). b–d Expression of adrenomedullin (ADM) mRNA and its receptors (CRLR, RAMP 1 and 2) in the heart, lungs, kidneys, and adrenals. These measurements were performed 3 h after the Adrecizumab injection and 24 h after the induction of sepsis. Kruskal-Wallis test followed by Dunn’s multiple comparison test was used. *p < 0.05 and ***p < 0.001

Fig. 4

Activation of the survival pathway in septic rats treated with Adrecizumab. Western blot analyses of cardiac P-Akt/Akt and p62. Kruskal-Wallis test followed by Dunn’s multiple comparison test was used. *p < 0.05

Fig. 5

Adrecizumab decreases ROS production. Adrecizumab decreased ROS production in the septic myocardium within 3 h. Dihydroethidium (DHE; Sigma-Aldrich) staining was used to evaluate the in situ levels of superoxide anion in the myocardium. Data are expressed as a percentage of region of interest (percent of ROI). Kruskal-Wallis test followed by Dunn’s multiple comparison test was used. *p < 0.05 and ***p < 0.001