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Updated: Jul 6, 2026
Brain Death Induction in Mice Using Intra-Arterial Blood Pressure Monitoring and Ventilation via Tracheostomy
Published on: April 17, 2020
Inhibition of the complement component C5 and the Toll-like receptor molecule CD14 prevents systemic and local kidney
Tom E Mollnes1,2, Neeltina M Jager3, Petra J Ottens4
1Department of Immunology, Oslo University Hospital and University of Oslo, Oslo, Norway. t.e.mollnes@medisin.uio.no.
Abstract:
Brain death (BD) induces a systemic inflammation impairing donor organ quality. Complement and Toll-like receptors (TLRs), with the key co-receptor CD14 molecule, are key innate recognition immune systems. We hypothesized that dual inhibition of complement (C5) and TLRs (CD14) will prevent BD-mediated innate immune inflammation. BD was induced in mice either untreated, treated with a C5 inhibitor, a CD14 inhibitor, or both. Blood and kidneys were collected after three hours. Cytokines were analyzed using enzyme-immuno assays and qPCR. In plasma, a substantial increase in interleukin-6 (IL-6), KC (IL-8 analogue), IL-12, monocyte chemoattractant protein (MCP-1), macrophage inflammatory protein MIP-1α, MIP-1β, eotaxin, RANTES and G-CSF (median 90-fold increase) were observed in BD animals compared to sham (all p < 0.01). In kidneys, BD substantially induced IL-6, KC, TNF, MCP-1, P-Selectin, and VCAM-1 (all p < 0.01). In plasma, C5 and CD14 inhibition, either single or in combination, virtually abolished all cytokines in the BD animals (> 90% for six cytokines and 70-90% for three) (all p < 0.01). In kidneys, the effect of inhibition was similar (> 90% for IL-6 and KC and 60-80% for TNF and MCP-1 (all p < 0.01). Single and combined inhibition of C5 and CD14 efficiently prevented BD-induced systemic inflammation and reduced local kidney inflammation in a mouse model.
Insights
Dual inhibition of complement C5 and Toll-like receptor CD14 prevents brain death-induced inflammation. This strategy significantly reduces systemic and local cytokine levels, improving donor organ quality in a mouse model.
Area of Science:
- Immunology
- Transplantation Immunology
- Inflammation Research
Background:
- Brain death (BD) triggers systemic inflammation, compromising donor organ viability.
- Innate immune system components, including complement (C5) and Toll-like receptors (TLRs) via CD14, play critical roles in this inflammatory response.
- Targeting these pathways may mitigate BD-induced organ damage.
Purpose of the Study:
- To investigate the efficacy of dual inhibition of complement C5 and CD14 in preventing brain death-mediated innate immune inflammation.
- To assess the impact of C5 and CD14 inhibition on cytokine levels in plasma and kidney tissue following induced brain death in a murine model.
Main Methods:
- Brain death was induced in mice.
- Mice were treated with either a C5 inhibitor, a CD14 inhibitor, or both.
- Plasma and kidney samples were collected, and cytokine levels were analyzed using enzyme-immunoassays and qPCR.
Main Results:
- Brain death significantly elevated multiple pro-inflammatory cytokines in plasma and kidney tissue.
- Single and dual inhibition of C5 and CD14 effectively suppressed the increase in most measured cytokines.
- Inhibition demonstrated >90% reduction for key cytokines like IL-6 and KC in plasma and kidneys.
Conclusions:
- Dual inhibition of C5 and CD14 is a promising strategy to prevent brain death-induced systemic inflammation.
- This approach significantly reduces local kidney inflammation, potentially improving donor organ quality.
- Targeting complement and TLR pathways offers a therapeutic avenue for mitigating organ damage in the context of brain death.
