Metalloproteinase inhibition reduces lung injury and improves survival after cecal ligation and puncture in rats.
BACKGROUND
Neutrophil activation with concomitant matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) release has been implicated in the development of sepsis-induced acute lung injury. We hypothesized that COL-3, a chemically modified tetracycline known to inhibit MMP-2 and MMP-9, would reduce lung injury and improve survival in rats following cecal ligation and puncture (CLP).


METHODS
Sprague-Dawley rats were separated into five groups: 1) sham CLP+ carboxymethylcellulose (CMC; vehicle for COL-3, n = 6); 2) sham CLP + COL-3 (n = 6); 3) CLP + CMC (n = 10); 4) CLP + single-dose (SD) COL-3 administered concomitant with CLP (n = 9); and 5) CLP + multiple-dose (MD) COL-3 administered concomitant with CLP and at 24 h after CLP (n = 15). Rats were sacrificed at 168 h (7 days) or immediately after death, with survival defined as hours after CLP. Histological lung assessment was made based on neutrophil infiltration, alveolar wall thickening, and intraalveolar edema fluid. Lung MMP-2 and MMP-9 levels were assessed by immunohistochemistry. MMP-2 and MMP-9 levels were correlated with survival by simple regression analysis.


RESULTS
The mortality of rats in the cecal ligation and puncture without treatment group (CLP + CMC) was 70% at 168 h. A single dose of COL-3 in the CLP + COL-3 (SD) group significantly reduced mortality to 54%. Furthermore, with a repeat dose of COL-3 at 24 h after CLP, mortality was significantly reduced to 33%. Pathologic lung changes seen histologically in the CLP + CMC group were significantly reduced by COL-3. A significant reduction in lung tissue levels of MMP-2 and MMP-9 was noted in both groups treated with COL-3. Reduction of MMP-2 and MMP-9 levels correlated with improved survival.


CONCLUSIONS
Inhibition of MMP-2 and MMP-9 by COL-3 in a clinically relevant model of sepsis-induced acute lung injury reduces pulmonary injury and improves survival in a dose-dependent fashion. Our results suggest that prophylactic treatment with COL-3 in high-risk patients may reduce the morbidity and mortality associated with sepsis-induced acute respiratory distress syndrome.
Steinberg
Jay
J
Department of Surgery, SUNY Upsate Medical University, Syracuse, NY 13210, USA. steinbja@uptate.edu
Halter
Jeffrey
J
Schiller
Henry J
HJ
Dasilva
Monica
M
Landas
Steve
S
Gatto
Louis A
LA
Maisi
Paivi
P
Sorsa
Timo
T
Rajamaki
Minna
M
Lee
Hsi-Ming
HM
Nieman
Gary F
GF
D000818:Animals; D002432:Cecum; D002851:Chromatography, High Pressure Liquid; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000627:therapeutic use*; D008026:Ligation; D008168:Lung / Q000201:enzymology / Q000473:pathology; D008171:Lung Diseases / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000032:analysis / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000032:analysis / Q000378:metabolism; D061965:Matrix Metalloproteinase Inhibitors; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors*; D011677:Punctures; D051381:Rats; D017207:Rats, Sprague-Dawley; D012128:Respiratory Distress Syndrome / Q000209:etiology / Q000517:prevention & control; D018805:Sepsis / Q000150:complications* / Q000209:etiology; D013752:Tetracycline / Q000627:therapeutic use; D013754:Tetracyclines
D004791:Enzyme Inhibitors; D061965:Matrix Metalloproteinase Inhibitors; D013754:Tetracyclines; C117155:tetracycline CMT-3; D008666:Metalloendopeptidases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; D013752:Tetracycline