Objectives: Sepsis causes very high mortality and morbidity rates and remains one of the biggest medical challenges. This study investigates whether plasma levels of both matrix metalloproteinase 8 and tumor necrosis factor receptor 1 are associated with sepsis severity and also investigates the therapeutic applicability of simultaneous inhibition of the two molecules in sepsis.
Design: Observational human pilot study-prospective controlled animal study.
Setting: University hospital and research laboratory.
Subjects: Sepsis patients and C57BL/6 mice deficient for matrix metalloproteinase 8 and/or tumor necrosis factor receptor 1.
Intervention: Plasma and whole blood RNA were collected from 13 sepsis patients for 7 consecutive days and within 24 hours of admission to ICU. Matrix metalloproteinase 8 and tumor necrosis factor receptor 1 plasma and expression levels were determined in these patients. Mice deficient for both matrix metalloproteinase 8 and tumor necrosis factor receptor 1 were generated and subjected to endotoxemia and cecal ligation and puncture. Additionally, a bispecific Nanobody that simultaneously blocks matrix metalloproteinase 8 and tumor necrosis factor receptor 1 was created.
Measurements and main results: Plasma levels of matrix metalloproteinase 8 and tumor necrosis factor receptor 1 were positively correlated with the Sequential Organ Failure Assessment score (r, 0.51 and 0.58) and interleukin 6 levels (r, 0.59 and 0.52) in 13 sepsis patients. Combined elimination of tumor necrosis factor receptor 1 and matrix metalloproteinase 8 in double knockout mice resulted in superior survival in endotoxemia and CLP compared with single knockouts and wild-type mice. Cotreatment with our bispecific Nanobody in CLP resulted in improved survival rates (28% vs 19%) compared with untreated mice.
Conclusions: Inhibition of matrix metalloproteinase 8 and tumor necrosis factor receptor 1 might have therapeutic potential to treat sepsis and proof-of-principle was provided as therapeutics that inhibit both tumor necrosis factor receptor 1 and matrix metalloproteinase 8 are effective in CLP.