Keratinocyte growth factor protects against elastase-induced pulmonary emphysema in mice

Abstract

Pulmonary emphysema is characterized by persistent inflammation and progressive alveolar destruction. The keratinocyte growth factor (KGF) favorably influences alveolar maintenance and repair and possesses anti-inflammatory properties. We aimed to determine whether exogenous KGF prevented or corrected elastase-induced pulmonary emphysema in vivo. Treatment with 5 mg x kg(-1) x day(-1) KGF before elastase instillation prevented pulmonary emphysema. This effect was associated with 1) a sharp reduction in bronchoalveolar lavage fluid total protein and inflammatory cell recruitment, 2) a reduction in the pulmonary expression of the chemokines CCL2 (or monocyte chemoattractant protein-1) and CXCL2 (or macrophage inflammatory protein-2alpha) and of the adhesion molecules ICAM-1 and VCAM-1, 3) a reduction in matrix metalloproteinase (MMP)-2 and MMP-9 activity at day 3, and 4) a major reduction in DNA damage detected by terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL) in alveolar cells at day 7. Treatment with KGF after elastase instillation had no effect on elastase-induced emphysema despite the conserved expression of the KGF receptor in the lungs of elastase-instilled animals as determined by immunohistochemistry. In vitro, KGF abolished the elastase-induced increase in CCL2, CXCL2, and ICAM-1 mRNA in the MLE-12 murine alveolar epithelial cell line. We conclude that KGF pretreatment protected against elastase-induced pulmonary inflammation, activation of MMPs, alveolar cell DNA damage, and subsequent emphysema in mice.

Role of nitric oxide synthases in elastase-induced emphysema

“…11 In some experiments, iNOS À/À and eNOS À/À animals were used, with wild-type C57BL/6 mice as controls (Jackson Laboratory, Bar Harbor, ME, USA). In other experiments, wild-type mice (Janvier, Le Genest Saint-Isle, France) were treated subcutaneously with two injections of 10 mg/kg (20 mg/kg/ day) N-3-aminomethyl-benzyl-acetamidine-dihydrochloride (1400W, Cayman Chemical, Ann Arbor, MI, USA), a specific iNOS inhibitor, 12 from the day before tracheal instillation to the day they were killed, whereas control mice received saline injections.…”

“…The sequences of primers are indicated in Supplementary Table 1. Normalization was achieved by quantification of the expression of either CXXC1 or ribosomal protein 13 mRNA (RPL13) as described previously, 11 chosen as control housekeeping genes (HKG) among four HKG tested because of their stable expression in the different conditions of the experiment (KO iNOS and 1400W-treated mice with or without tracheal instillation of elastase), and/or their adequate expression level as compared with the considered target gene. All PCR conditions were adjusted in order to obtain equivalent optimal amplification efficiency between the different assays.…”

“…Gelatin zymography was performed on BALF as described previously. 11 To explore the effect of iNOS inactivation on the mechanisms driving lung inflammation in this model, we quantified the expression of CCL2, CXCL2, tumor necrosis factor-a (TNFa), and interleukin-6 (IL6) mRNAs normalized by CXXC1 mRNA, as described above. The sequences of primers are indicated in Supplementary Table 1.…”

Longitudinal and noninvasive assessment of emphysema evolution in a murine model using proton MRI

“…The trachea was surgically exposed, and 5 U in 50 mL of porcine pancreatic elastase (purchased from Elastin Products, Owensville, MO) was injected intratracheally in nine mice (elastase-instilled group), whereas the rest of the animals (N ¼ 5) were instilled with 50 mL of saline (control group; Ref. 15). All animals survived the instillation protocol.…”

Bronchopulmonary dysplasia and emphysema: in search of common therapeutic targets

“…antichemokine or receptor blockade in hyperoxia-exposed rats [17,65] pentoxyfilline in VLBW infants [64] No adverse effects observed inhibitory peptide in mouse model [43] curcumin [66], simvastatin [67], lovastatin [68], or HO-1 [69] Retinoids RA in hyperoxic model in rats [82] RA in angiogenic inhibition in mice [83] vitamin A in premature baboons [86] RA in rats and mice with or without inhibited alveolar septation [77,81] RA in mouse models [85] Growth factor supplementation VEGF [54] or FGF7 [98] in hyperoxia-exposed rats HGF [99] or EPO [83] in mouse models VEGF injurious in mouse prenatal lung [51] FGF7 in mouse model, preventive [101] HGF in rats [100] FGF7 in mouse model, curative [101] …”