Combined C5 and CD14 inhibition balances immunological miRNA responses after multiple trauma in pigs
Rald V M Groven1, Ümit Mert2, Johannes Greven3
1Department of Cell Biology-Inspired Tissue Engineering, MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, Universiteitssingel 40, Maastricht 6229 ER, the Netherlands; Division of Trauma Surgery, Department of Surgery, Maastricht University Medical Center+, P. Debyelaan 25, Maastricht 6229 HX, the Netherlands; Experimental Orthopaedics and Trauma surgery, Department of Orthopaedic, Trauma and Reconstructive Surgery, RWTH Aachen University Hospital, Pauwelsstraße 30, Aachen 52074, Germany.
Background:
Combined inhibition of complement-component C5 and Toll-Like Receptor CD14 is a promising therapeutic strategy to attenuate post-traumatic inflammatory-complications. The effect of this inhibition on miRNA expression at the fracture site and in systemic circulation was assessed in a porcine multiple-trauma model. Expression of the mRNA targets of deregulated miRNAs was determined at the fracture site and in lung and liver.
Methods:
Two experimental groups, intramedullary nailing (control; n = 8) and intramedullary nailing with combined C5/CD14 inhibition (n = 4), were compared using an established porcine multiple-trauma model. Fracture hematoma, fractured bone, unfractured control bone, lung, and liver samples were collected. Extracellular-vesicles (EVs) were isolated from plasma at 1.5, 2.5, 24, and 72 h post-trauma. MiRNA qPCR array analyses were performed on pooled fxH, fX, CB, and EV samples. In silico mRNA target prediction and mRNA qPCR analyses were conducted on all samples.
Results:
The fracture site miRNA signature in the C5/CD14 inhibition group was anti-inflammatory compared to intramedullary nailing alone, based on miRNA and mRNA qPCR analyses, with downregulation of anti-osteogenic miRNAs. Furthermore, C5/CD14 inhibition reduced pro-inflammatory and pro-fibrotic EV-carried miRNA expression in systemic circulation and their downstream mRNA targets in lung and liver.
Conclusions:
Anti-inflammatory miRNA and mRNA expression were upregulated at the injury site in the C5/CD14 inhibition group, while pro-osteogenic pathways were preserved by downregulating anti-osteogenic miRNAs. Systemically, C5/CD14 inhibition reduced EV-carried inflammatory miRNA expression, consistent with mRNA target analyses in lung and liver. Thus, C5/CD14 inhibition may be a novel therapeutic to modulate post-traumatic immune responses and decrease systemic effects of surgical trauma.
Insights
Combined inhibition of complement C5 and Toll-Like Receptor CD14 reduces post-traumatic inflammation. This therapy modulates miRNA and mRNA expression at fracture sites and systemically, preserving bone healing while decreasing lung and liver inflammation.
Area of Science:
- Immunology
- Molecular Biology
- Trauma Surgery
Background:
- Combined inhibition of complement C5 and Toll-Like Receptor CD14 is a potential strategy for post-traumatic inflammatory complications.
- The study investigated the impact of this inhibition on miRNA expression in a porcine multiple-trauma model.
Purpose of the Study:
- To assess the effect of combined C5/CD14 inhibition on miRNA and mRNA expression at fracture sites and in systemic circulation.
- To determine if this inhibition can attenuate post-traumatic inflammation and its systemic effects.
Main Methods:
- A porcine multiple-trauma model was used, comparing intramedullary nailing (control) with combined C5/CD14 inhibition.
- Samples from fracture hematoma, bone, lung, liver, and plasma-derived extracellular vesicles (EVs) were analyzed for miRNA and mRNA expression.
- MiRNA qPCR arrays and in silico mRNA target prediction were employed.
Main Results:
- C5/CD14 inhibition resulted in an anti-inflammatory miRNA signature at the fracture site, with downregulation of anti-osteogenic miRNAs.
- Systemic administration of C5/CD14 inhibition reduced pro-inflammatory and pro-fibrotic EV-carried miRNAs and their mRNA targets in the lung and liver.
- Anti-inflammatory and anti-fibrotic pathways were modulated by this combined inhibition.
Conclusions:
- Combined C5/CD14 inhibition upregulates anti-inflammatory miRNA/mRNA expression at the injury site, preserving pro-osteogenic pathways.
- Systemically, this inhibition decreases inflammatory EV-carried miRNAs, mitigating downstream effects in organs like the lung and liver.
- C5/CD14 inhibition represents a novel therapeutic approach to modulate post-traumatic immune responses and reduce surgical trauma's systemic impact.