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Proteinase 3 contributes to endothelial dysfunction in an experimental model of sepsis
Eric K Patterson1, Carolina Gillio-Meina2, Claudio M Martin1,3
1Centre for Critical Illness Research, 151158Lawson Health Research Institute, Lawson Health Research Institute, London, N6A 5W9, Canada.
Abstract:
In sepsis-induced inflammation, polymorphonuclear neutrophils (PMNs) contribute to vascular dysfunction. The serine proteases proteinase 3 (PR3) and human leukocyte elastase (HLE) are abundant in PMNs and are released upon degranulation. While HLE's role in inflammation-induced endothelial dysfunction is well studied, PR3's role is largely uninvestigated. We hypothesized that PR3, similarly to HLE, contributes to vascular barrier dysfunction in sepsis. Plasma PR3 and HLE concentrations and their leukocyte mRNA levels were measured by ELISA and qPCR, respectively, in sepsis patients and controls. Exogenous PR3 or HLE was applied to human umbilical vein endothelial cells (HUVECs) and HUVEC dysfunction was assessed by FITC-dextran permeability and electrical resistance. Both PR3 and HLE protein and mRNA levels were significantly increased in sepsis patients (P < 0.0001 and P < 0.05, respectively). Additionally, each enzyme independently increased HUVEC monolayer FITC-dextran permeability (P < 0.01), and decreased electrical resistance in a time- and dose-dependent manner (P < 0.001), an effect that could be ameliorated by novel treatment with carbon monoxide-releasing molecule 3 (CORM-3). The serine protease PR3, in addition to HLE, lead to vascular dysfunction and increased endothelial permeability, a hallmark pathological consequence of sepsis-induced inflammation. CORMs may offer a new strategy to reduce serine protease-induced vascular dysfunction.
Insights
Proteinase 3 (PR3), a serine protease abundant in neutrophils, exacerbates sepsis-induced vascular dysfunction and endothelial permeability, similar to human leukocyte elastase (HLE). Carbon monoxide-releasing molecules (CORMs) may mitigate this damage.
Area of Science:
- Vascular Biology
- Inflammation Research
- Sepsis Pathophysiology
Background:
- Sepsis-induced inflammation involves polymorphonuclear neutrophils (PMNs) contributing to vascular dysfunction.
- Serine proteases proteinase 3 (PR3) and human leukocyte elastase (HLE) are released by PMNs.
- While HLE's role is known, PR3's contribution to endothelial dysfunction in sepsis is uninvestigated.
Purpose of the Study:
- To investigate the role of PR3 in sepsis-induced vascular barrier dysfunction.
- To compare the effects of PR3 and HLE on endothelial cells.
- To explore potential therapeutic strategies using carbon monoxide-releasing molecules (CORMs).
Main Methods:
- Measured plasma PR3 and HLE concentrations and leukocyte mRNA levels in sepsis patients and controls using ELISA and qPCR.
- Applied exogenous PR3 or HLE to human umbilical vein endothelial cells (HUVECs) in vitro.
- Assessed HUVEC dysfunction via FITC-dextran permeability and electrical resistance measurements.
Main Results:
- Both PR3 and HLE protein and mRNA levels were significantly elevated in sepsis patients.
- Exogenous PR3 and HLE independently increased HUVEC monolayer permeability and decreased electrical resistance.
- The detrimental effects of PR3 and HLE on HUVECs were ameliorated by treatment with CORM-3.
Conclusions:
- The serine protease PR3 contributes to vascular dysfunction and increased endothelial permeability in sepsis, similar to HLE.
- PR3 and HLE induce endothelial barrier dysfunction independently.
- CORMs represent a potential therapeutic strategy to reduce serine protease-mediated vascular damage in sepsis.
