Peptide inhibition of acute lung injury in a novel two-hit rat model

Abstract

Acute lung injury (ALI) often causes severe trauma that may progress to significant morbidity and mortality. ALI results from a combination of the underlying clinical condition of the patient (e.g., inflammation) with a secondary insult such as viral pneumonia or a blood transfusion. While the secondary insult may be variable, the rapidly progressive disease process leading to pulmonary failure is typically mediated by an overwhelming innate immunological or inflammatory reaction driven by excessive complement and neutrophil-mediated inflammatory responses. We recently developed a ‘two-hit’ ALI rat model mediated by lipopolysaccharide followed by transfusion of incompatible human erythrocytes resulting in complement activation, neutrophil-mediated ALI and free DNA in the blood indicative of neutrophil extracellular trap formation. The objective of this study was to evaluate the role of peptide inhibitor of complement C1 (RLS-0071), a classical complement pathway inhibitor and neutrophil modulator in this animal model. Adolescent male Wistar rats were infused with lipopolysaccharide followed by transfusion of incompatible erythrocytes in the presence or absence of RLS-0071. Blood was collected at various time points to assess complement C5a levels, free DNA and cytokines in isolated plasma. Four hours following erythrocyte transfusion, lung tissue was recovered and assayed for ALI by histology. Compared to animals not receiving RLS-0071, lungs of animals treated with a single dose of RLS-0071 showed significant reduction in ALI as well as reduced levels of C5a, free DNA and inflammatory cytokines in the blood. These results demonstrate that RLS-0071 can modulate neutrophil-mediated ALI in this novel rat model.

RLS-0071, a novel anti-inflammatory agent, significantly reduced inflammatory biomarkers in a randomised human evaluation of mechanisms and safety study

“…These results were persistent with a trend towards significance in the natural log transformed sputum percentages of neutrophils at 24 hours post LPS and demonstrate a consistent pattern. These data demonstrate that RLS-0071 can markedly decrease neutrophil infiltration into the lungs after an inflammatory insult and confirm translatability of the animal model of acute lung injury [8].…”

“…There are multiple factors that can influence sputum MPO and NE levels including neutrophil numbers in the lungs, neutrophil activation and release of granule contents and NETosis. Overall, these results suggest a coherent pattern of RLS-0071 modulating neutrophil infiltration into the lungs and multiple neutrophil effectors after inhalation of LPS by humans [4][5][6][7][8].…”

“…RLS-0071 has been evaluated in a single-ascending dose and multiple-ascending dose Phase 1 healthy volunteer study with no clinically significant changes in safety parameters and expected adverse events were similar between active drug and placebo [9]. Additionally, exploratory biomarker and target engagement assays showed classical complement pathway inhibition and MPO binding by RLS-0071, thus verifying target engagement in human subjects that is consistent with the inhibition of complement and neutrophil inflammation in the preclinical acute lung injury model data [8].…”

“…This 2-hit insult induces a rapid inflammatory resulting in significant lung pathogenesis mediated by infiltrating neutrophils [7]. A single intravenous (IV) dose of RLS-0071 in the model results in preservation of normal lung histology, dramatically decreased neutrophil migration into the lungs, and significantly decreased levels of Th-1 and Th-17 proinflammatory cytokines [8]. RLS-0071 has been evaluated in a single-ascending dose and multiple-ascending dose Phase 1 healthy volunteer study with no clinically significant changes in safety parameters and expected adverse events were similar between active drug and placebo [9].…”

The EPICC Family of Anti-Inflammatory Peptides: Next Generation Peptides, Additional Mechanisms of Action, and In Vivo and Ex Vivo Efficacy

“…Additionally, significant increases in inflammatory cytokines (IL-1a, IL-1b, IL-6, IFN-g, IL-17, IL-18, TNFa) and chemokines (MCP-1, MIP-1a and MIP-2) are observed. Animals receiving a single prophylactic dose of 40mg/kg RLS-0071 either two minutes prior to transfusion or single rescue doses at 0.5 minutes and up to 180 minutes after incompatible RBC transfusion exhibited significant decreases in lung damage, C5a, and free DNA levels and reduction of inflammatory cytokines and chemokines compared to the sham animals ( 98 ). A single rescue dose of 10mg/kg was also protective.…”