u-0126 and Airway-Remodeling

To explore the role of IL-33 in asthmatic airway remodeling.. Male BALB/c mice were randomly divided into 3 groups: a control group, an ovalbumin (OVA) group, and an anti-IL-33 antibody combined with OVA group. The airway remodeling features in mice were observed by HE staining. In addition, the expressions of IL-33, alpha smooth muscle actin (α-SMA), and type 1 collagen (Col1) in the airway of mice were detected by immunohistochemistry and Western blotting. Finally, Western blotting was used to determine the activation of extracellular signal-regulated kinase 1/2 (ERK1/2) and mitogen- and stress-activated protein kinase 1 (MSK1) in the lungs of mice. In vitro, human lung fibroblasts (HLF-1) were pretreated with the ERK1/2 inhibitor U0126 or the MSK1 inhibitor H89 respectively, and then treated with the human recombinant IL-33 (rIL-33). Then real-time quantitative PCR and Western blotting were used to test the expressions of α-SMA and Col1. Immunofluorescence cytochemistry and Western blotting were also used to observe the phosphorylation of ERK1/2 and MSK1 in HLF-1 cells.. The pre-treatment with the ERK1/2 inhibitor U0126 or anti-IL-33 antibody significantly abolished the OVA-induced airway remodeling, increased expressions of IL-33, α-SMA, Col1, and phosphorylation of ERK1/2 and MSK1 in the airway of mice. In vitro, the increased expressions of α-SMA and Col1 and the phosphorylation of ERK1/2 and MSK1 induced by rIL-33 in HLF-1 cells were markedly inhibited by the pre-treatment with U0126 or H89.. IL-33 promotes airway remodeling in asthmatic mice via the ERK1/2-MSK1 signaling pathway.

Topics: Airway Remodeling; Animals; Asthma; Butadienes; Disease Models, Animal; Humans; Interleukin-33; Male; MAP Kinase Signaling System; Mice; Mice, Inbred BALB C; Nitriles; Ribosomal Protein S6 Kinases, 90-kDa

Airway smooth muscle cells (ASMCs) play a key role in the process of asthma airway remodeling. Urotensin II (UII) and transforming growth factor (TGF)-β are potent mitogens for ASMCs proliferation. The study was aimed to determine whether UII-upregulated TGF-β-mediated ASMCs proliferation and extracellular signal-regulated kinase (ERK) was required for such an effect. OVA-sensitized rats were challenged to induce asthma. Lung morphology and airway dynamic parameters were monitored. ASMCs from control and asthma rats were purified for the measurement of UII and TGF-β1 expression. In vitro experiments were conducted to determine the direct effect of UII on TGF-β1 expression by ASMCs. Finally, U0126, an ERK inhibitor was used to examine the role of ERK pathway in UII mediated TGF-β1 upregulation. We found that both UII and TGF-β1 were upregulated in asthma lung tissues. In vitro study on ASMCs further revealed that UII may render its effect on ASMCs cells through the upregulation of TGF-β1. Data also supported the conclusion that ERK pathway was required, but not sufficient in UII-induced TGF-β1 upregulation. The current study provides new evidence that UII is involved in the TGF-β mediated mitogenic effect on ASMCs. UII, at least partially, uses ERK pathway to render such effect.

Topics: Airway Remodeling; Animals; Asthma; Butadienes; Cell Proliferation; Extracellular Signal-Regulated MAP Kinases; Gene Expression Regulation; Humans; Lung; Male; MAP Kinase Signaling System; Myocytes, Smooth Muscle; Nitriles; Ovalbumin; Rats; Rats, Sprague-Dawley; Transforming Growth Factor beta1; Urotensins