Inhibition of Leukocyte Elastase, Polymorphonuclear Chemoinvasion, and Inflammation-Triggered Pulmonary Fibrosis by a 4-Alkyliden-β-lactam with a Galloyl Moiety

Abstract

␤-Lactams, a well known class of antibiotics, have been investigated as inhibitors of the disruptive protease released by inflammatory cells, leukocyte elastase (LE). We have synthesized a new ␤-lactam with an N-linked galloyl moiety, the latter identified as strategic in conferring anti-LE properties to some flavonols. This N-galloyl-derivative ␤-lactam inhibits the LE activity with a K i of 0.7 M, whereas it exerts weak activity against cathepsin G and protease-3 (IC 50 Ͼ 100 M), and matrix metalloproteinase (MMP)-2 and MMP-9. Without affecting chemotactic response and viability of polymorphonuclear (PMN) leukocytes, the compound efficiently restrains their chemoinvasion (IC 50 of 1-2 M) blocking the LE-triggered activation of pro-MMP-9, instrumental to extravasation. Daily i.p. injection of compound enhances resolution in a pulmonary inflammation model, significantly reducing consequent fibrosis. These results indicate that the new ␤-lactam is a potent anti-inflammatory compound with therapeutic potential.

Inflammation, inflammatory cells and angiogenesis: decisions and indecisions

“…For example, components known to inhibit inflammation and angiogenesis effectively target neutrophils in vitro and in vivo [48][49][50]. In contrast, angiostatin, an angiogenesis inhibitor identified in vivo [51] has been found to effectively target monocytes, macrophages, neutrophils and related cells in vitro and in vivo [30,32,[52][53][54][55].…”

3-(2,4-Dichlorophenyl)-4-(1-methyl-1H-indol-3-yl)-1H-pyrrole-2,5-dione (SB216763), a Glycogen Synthase Kinase-3 Inhibitor, Displays Therapeutic Properties in a Mouse Model of Pulmonary Inflammation and Fibrosis

“…Immunostaining was visualized with diaminobenzidine and then counterstained with hematoxylin and mounted using Poly-Mount medium (Polysciences, Warrington, PA) Determination of Hydroxyproline. The hydroxyproline content of mouse lung was determined by standard methods as described previously (Dell'Aica et al, 2006). In brief, after rinsing with PBS, the lung was defatted, dried, weighed, and hydrolyzed for 22 h at 110°C in 6 N HCl.…”

“…Absorbance was measured at 561 nm, and the amount of hydroxyproline was determined against a standard curve. Results were expressed as percentage of collagen content (weight/weight) relative to dry weight of the tissue sample, considering that OH-Pro accounts for approximately 11.8% of the amino acid content (Dell'Aica et al, 2006). TUNEL Assay.…”

Overexpression of SERPIN B3 promotes epithelial proliferation and lung fibrosis in mice

“…24 Briefly, after rinsing with PBS, the lung was defatted, dried, weighed and hydrolyzed for 22 h at 110 1C in 6 N HCl. Aliquots were then assayed by adding chloramine T solution for 20 min, 3.15 M perchloric acid for 5 min, and Erlich's reagent at 60 1C for 20 min.…”