Mauo Ying Bien

Osthole inhibits the invasive ability of human lung adenocarcinoma cells via suppression of NF-κB-mediated matrix metalloproteinase-9 expression.

The induction of matrix metalloproteinase (MMP)-9 is particularly important for the invasiveness of various cancer cells. Osthole, a natural coumarin derivative extracted from traditional Chinese medicines, is known to inhibit the proliferation of a variety of tumor cells, but the effect of osthole on the invasiveness of tumor cells is largely unknown. This study determines whether and by what mechanism osthole inhibits invasion in CL1-5 human lung adenocarcinoma cells. Herein, we found that osthole effectively inhibited the migratory and invasive abilities of CL1-5 cells. A zymographic assay showed that osthole inhibited the proteolytic activity of MMP-9 in CL1-5 cells. Inhibition of migration, invasion, and MMP2 and/or MMP-9 proteolytic activities was also observed in other lung adenocarcinoma cell lines (H1299 and A549). We further found that osthole inhibited MMP-9 expression at the messenger RNA and protein levels. Moreover, a chromatin immunoprecipitation assay showed that osthole inhibited the transcriptional activity of MMP-9 by suppressing the DNA binding activity of nuclear factor (NF)-κB in the MMP-9 promoter. Using reporter assays with point-mutated promoter constructs further confirmed that the inhibitory effect of osthole requires an NF-κB binding site on the MMP-9 promoter. Western blot and immunofluorescence assays demonstrated that osthole inhibited NF-κB activity by inhibiting IκB-α degradation and NF-κB p65 nuclear translocation. In conclusion, we demonstrated that osthole inhibits NF-κB-mediated MMP-9 expression, resulting in suppression of lung cancer cell invasion and migration, and osthole might be a potential agent for preventing the invasion and metastasis of lung cancer.

Systemic human orbital fat-derived stem/stromal cell transplantation ameliorates acute inflammation in lipopolysaccharide-induced acute lung injury

Objective:Acute lung injury results in acute respiratory distress syndrome. There is no standard therapy for acute respiratory distress syndrome but supportive care. Stem cells offer a new therapeutic potential for tissue regeneration as a result of their self-renewal, multipotency, and paracrine capabilities. The objective of this study is to investigate the effects and the mechanisms of systemic human orbital fat-derived stem/stromal cell transplantation on lipopolysaccharide-induced acute lung injury. Design:Prospective, randomized, controlled study. Setting:University-affiliated research institute. Subjects:Male BALB/c mice. Interventions:Twenty-five micrograms lipopolysaccharide in 50 &mgr;L sterile saline or 50 &mgr;L of sterile saline was delivered through intratracheal injection. Twenty mins later, the animals were further randomized into subgroups that received either a tail vein injection of 3 × 105 orbital fat-derived stem/stromal cells in 50 &mgr;L phosphate-buffered saline or 50 &mgr;L phosphate-buffered saline. Measurements and Main Results:Low immunogenicity and immune-tolerated of orbital fat-derived stem/stromal cells were observed in this xenotransplanted model. Orbital fat-derived stem/stromal cells significantly reduced lipopolysaccharide-induced pulmonary inflammation, which was evidenced by a decrease in total protein concentration and neutrophil counts in alveolar fluid through bronchoalveolar lavage, reduced endothelial and alveolar epithelial permeability as well as neutrophil (Ly6G-expressing cells) and macrophage (CD68-expressing cells) infiltration. Lipopolysaccharide-induced expression of CD14, inducible nitric oxide synthase, and transforming growth factor-&bgr; in lung tissue was significantly inhibited by orbital fat-derived stem/stromal cells. Orbital fat-derived stem/stromal cells not only reduced the circulation numbers of macrophages and neutrophils (CD11b-expressing cells), but also decreased systemic proinflammatory chemokine levels such as macrophage inflammatory protein-1-&ggr;, B-lymphocyte chemoattractant, interleukin-12, and subsequent circulation helper T cell (CD4-expressing cells) numbers. Furthermore, few human orbital fat-derived stem/stromal cells were detectable in the recipient lung after acute inflammation subsided. Conclusions:Systemic orbital fat-derived stem/stromal cell transplantation was effective in modulating inflammation during acute lung injury. The therapeutic effect was attributed to the inhibition of acute inflammatory responses. (Crit Care Med 2012; 40:–1253)

Thrombin-induced NF-κB activation and IL-8/CXCL8 release is mediated by c-Src-dependent Shc, Raf-1, and ERK pathways in lung epithelial cells

In addition to its functions in thrombosis and hemostasis, thrombin also plays an important role in lung inflammation. Our previous report showed that thrombin activates the protein kinase C (PKC)α/c-Src and Gβγ/Rac1/PI3K/Akt signaling pathways to induce IκB kinase α/β (IKKα/β) activation, NF-κB transactivation, and IL-8/CXCL8 expressions in human lung epithelial cells (ECs). In this study, we further investigated the mechanism of c-Src-dependent Shc, Raf-1, and extracellular signal-regulated kinase (ERK) signaling pathways involved in thrombin-induced NF-κB activation and IL-8/CXCL8 release. Thrombin-induced increases in IL-8/CXCL8 release and κB-luciferase activity were inhibited by the Shc small interfering RNA (siRNA), p66Shc siRNA, GW 5074 (a Raf-1 inhibitor), and PD98059 (a mitogen-activated protein kinase (MAPK) kinase (MEK) inhibitor). Treatment of A549 cells with thrombin increased p66Shc and p46/p52Shc phosphorylation at Tyr239/240 and Tyr317, which was inhibited by cell transfection with the dominant negative mutant of c-Src (c-Src DN). Thrombin caused time-dependent phosphorylation of Raf-1 and ERK, which was attenuated by the c-Src DN. Thrombin-induced IKKα/β phosphorylation was inhibited by GW 5074 and PD98059. Treatment of cells with thrombin induced Gβγ, c-Src, and p66Shc complex formation in a time-dependent manner. Taken together, these results show for the first time that thrombin activates Shc, Raf-1, and ERK through Gβγ, c-Src, and Shc complex formation to induce IKKα/β phosphorylation, NF-κB activation, and IL-8/CXCL8 release in human lung ECs.

Apoptosis signal-regulating kinase 1 mediates denbinobin-induced apoptosis in human lung adenocarcinoma cells

In the present study, we explore the role of apoptosis signal-regulating kinase 1 (ASK1) in denbinobin-induced apoptosis in human lung adenocarcinoma (A549) cells. Denbinobin-induced cell apoptosis was attenuated by an ASK1 dominant-negative mutant (ASK1DN), two antioxidants (N-acetyl-L-cysteine (NAC) and glutathione (GSH)), a c-Jun N-terminal kinase (JNK) inhibitor (SP600125), and an activator protein-1 (AP-1) inhibitor (curcumin). Treatment of A549 cells with denbinobin caused increases in ASK1 activity and reactive oxygen species (ROS) production, and these effects were inhibited by NAC and GSH. Stimulation of A549 cells with denbinobin caused JNK activation; this effect was markedly inhibited by NAC, GSH, and ASK1DN. Denbinobin induced c-Jun phosphorylation, the formation of an AP-1-specific DNA-protein complex, and Bim expression. Bim knockdown using a bim short interfering RNA strategy also reduced denbinobin-induced A549 cell apoptosis. The denbinobin-mediated increases in c-Jun phosphorylation and Bim expression were inhibited by NAC, GSH, SP600125, ASK1DN, JNK1DN, and JNK2DN. These results suggest that denbinobin might activate ASK1 through ROS production to cause JNK/AP-1 activation, which in turn induces Bim expression, and ultimately results in A549 cell apoptosis.

CXCL12 induces connective tissue growth factor expression in human lung fibroblasts through the Rac1/ERK, JNK, and AP-1 pathways

CXCL12 (stromal cell-derived factor-1, SDF-1) is a potent chemokine for homing of CXCR4+ fibrocytes to injury sites of lung tissue, which contributes to pulmonary fibrosis. Overexpression of connective tissue growth factor (CTGF) plays a critical role in pulmonary fibrosis. In this study, we investigated the roles of Rac1, extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and activator protein-1 (AP-1) in CXCL12-induced CTGF expression in human lung fibroblasts. CXCL12 caused concentration- and time-dependent increases in CTGF expression and CTGF-luciferase activity. CXCL12-induced CTGF expression was inhibited by a CXCR4 antagonist (AMD3100), small interfering RNA of CXCR4 (CXCR4 siRNA), a dominant negative mutant of Rac1 (RacN17), a mitogen-activated protein kinase (MAPK) kinase (MEK) inhibitor (PD98059), a JNK inhibitor (SP600125), a p21-activated kinase inhibitor (PAK18), c-Jun siRNA, and an AP-1 inhibitor (curcumin). Treatment of cells with CXCL12 caused activations of Rac1, Rho, ERK, and c-Jun. The CXCL12-induced increase in ERK phosphorylation was inhibited by RacN17. Treatment of cells with PD98059 and SP600125 both inhibited CXCL12-induced c-Jun phosphorylation. CXCL12 caused the recruitment of c-Jun and c-Fos binding to the CTGF promoter. Furthermore, CXCL12 induced an increase in α-smooth muscle actin (α-SMA) expression, a myofibroblastic phenotype, and actin stress fiber formation. CXCL12-induced actin stress fiber formation and α-SMA expression were respectively inhibited by AMD3100 and CTGF siRNA. Taken together, our results suggest that CXCL12, acting through CXCR4, activates the Rac/ERK and JNK signaling pathways, which in turn initiates c-Jun phosphorylation, and recruits c-Jun and c-Fos to the CTGF promoter and ultimately induces CTGF expression in human lung fibroblasts. Moreover, overexpression of CTGF mediates CXCL12-induced α-SMA expression.

Plasma endothelial cell-specific molecule-1 (ESM-1) in management of community-acquired pneumonia

Abstract Background: Endothelial cell-specific molecule (ESM)-1 is a soluble proteoglycan expressed by the vascular endothelium and which also circulates in the bloodstream. Inflammatory cytokines and proangiogenic growth factors increase its expression, and increased serum levels are found in immunocompetent patients with sepsis. The aim of this study was to investigate differential changes in plasma levels of ESM-1 before and after antibiotic treatment in hospitalized adult patients with community-acquired pneumonia (CAP). Methods: Plasma ESM-1 levels were measured in 82 adult patients with CAP and 82 healthy controls using a commercial enzyme-linked immunosorbent assay (ELISA). Upon initial hospitalization, Acute Physiology and Chronic Health Evaluation II (APACHE II), CURB-65, and Pneumonia Severity Index (PSI) scores were determined to assess CAP severity in these patients. Results: Results showed a decline in the number of white blood cells (WBCs) and neutrophils, and decreases in the concentrations of C-reactive protein (CRP) and ESM-1 after antibiotic treatment. The plasma concentration of ESM-1, but not CRP or the WBC count, was correlated with the severity of CAP based on the PSI (r=0.554, p<0.001), CURB-65 (r=0.510, p<0.001), and APACHE II scores (r=0.447, p<0.001). Conclusions: Plasma levels of ESM-1 may be able to play a role in the diagnosis and clinical assessment of the severity of CAP, which could potentially guide the development of treatment strategies.

Thrombin induces inducible nitric oxide synthase expression via the MAPK, MSK1, and NF-κB signaling pathways in alveolar macrophages

In this study, we investigated the roles of mitogen activated protein kinase (MAPK), mitogen stress-activated protein kinase 1 (MSK1), and nuclear factor-κB (NF-κB) signaling pathways in thrombin-induced inducible nitric oxide synthase (iNOS) expression in alveolar macrophages (NR8383). Treatment of NR8383 cells with thrombin caused an increase in iNOS expression in a concentration- and time-dependent manner. Treatment of NR8383 cells with SB203580 (4-(4-Fluorophenyl)-2-[4-(methylsulfinyl)phenyl]-5-(4-pyridyl)-1H-imidazole, a p38 MAPK inhibitor), PD98059 (2-amino-3-methoxyflavone, a MAPK kinase (MEK) inhibitor), and SP600125 (anthra[1-9-cd]pyrazol-6(2H)-one, a JNK inhibitor) all inhibited thrombin-induced iNOS expression. Stimulation of cells with thrombin caused an increase in p38 MAPK, ERK, and JNK phosphorylation. Treatment of cells with Ro 31-8220 (an MSK1 inhibitor) and MSK1 small interfering RNA (MSK1 siRNA) both inhibited thrombin-induced iNOS expression. Thrombin caused time-dependent activation of MSK1 Ser531 phosphorylation, which was inhibited by SB203580 and PD98059, but not by SP600125. Treatment of cells with pyrrolidine dithiocarbamate (PDTC, an NF-κB inhibitor) inhibited thrombin-induced iNOS expression in a concentration-dependent manner. Treatment of NR8383 cells with thrombin induced κB-luciferase activity and p65 Ser276 phosphorylation. Thrombin-induced increases in p65 Ser276 phosphorylation and κB-luciferase activity were inhibited by SB203580, PD98059, Ro 31-8220, and MSK1 siRNA. Taken together, these results suggest that the signaling pathways of MAPK, MSK1, and NF-κB play important roles in thrombin-induced iNOS expression in alveolar macrophages.

Plasma long pentraxin 3 (PTX3) concentration is a novel marker of disease activity in patients with community-acquired pneumonia

Abstract Background: Long pentraxin 3 (PTX3) is an acute-phase protein secreted by various cells, including leukocytes and endothelial cells. Like C-reactive protein (CRP), it belongs to the pentraxin superfamily. The aim of this study was to investigate the differential changes in plasma levels of PTX3 between before and after antibiotic treatment in hospitalized adult patients with community-acquired pneumonia (CAP). Methods: Plasma PTX3 levels were measured in 61 adult patients with CAP and 60 healthy controls using a commercial enzyme-linked immunosorbent assay (ELISA). Upon initial hospitalization, APACHE II, CURB-65, and pneumonia severity index (PSI) scores were determined to assess CAP severity in patients. Results: The results showed a decline in the number of white blood cells (WBCs) and neutrophils, and decreases in the concentrations of CRP and PTX3 observed after antibiotic treatment. The plasma concentration of PTX3, but not CRP, was correlated with the severity of CAP based on the PSI (r=0.290, p=0.023), CURB-65 (r=0.312, p=0.015), and APACHE II scores (r=0.427, p=0.001). The PTX3 level also exhibited a significant correlation with the length of hospital stay (r=0.500, p<0.0001). Conclusions: PTX3 may be able to play a role in the diagnosis and clinical assessment of the severity of CAP, which could potentially guide the development of treatment strategies.

Involvement of phosphatidylcholine-phospholipase C and protein kinase C in peptidoglycan-induced nuclear factor-κB activation and cyclooxygenase-2 expression in RAW 264.7 macrophages

In this study, we examined the role of phosphatidylcholine-phospholipase C (PC-PLC) and protein kinase C (PKC) in peptidoglycan (PGN)-induced nuclear factor-kappaB (NF-kappaB) activation and cyclooxygenase-2 (COX-2) expression in RAW 264.7 macrophages. PGN-induced COX-2 expression was attenuated by a PC-PLC inhibitor (D609) and by PKC inhibitors (Go 6976 and Ro 31-8220), but not by a phosphatidylinositol-PLC (PI-PLC) inhibitor (U-73122). PGN caused an increase in PKC activity, and this effect was inhibited by D609, Go 6976, and Ro 31-8220, but not by U-73122. Furthermore, the PGN-mediated increases in kappaB-luciferase activity were also inhibited by D609 and Ro 31-8220. Our data demonstrate that PGN activates PC-PLC which induces PKC activation; this in turn initiates NF-kappaB activation, and ultimately induces COX-2 expression in RAW 264.7 macrophages.

Thrombin-Induced CCAAT/Enhancer-Binding Protein β Activation and IL-8/CXCL8 Expression via MEKK1, ERK, and p90 Ribosomal S6 Kinase 1 in Lung Epithelial Cells

Thrombin, a serine protease, is a well-known coagulation factor generated during vascular injury and plays an important role in lung inflammation. We previously showed that the c-Src– and Rac/PI3K/Akt-dependent NF-κB pathways are involved in thrombin-induced IL-8/CXCL8 expression in human lung epithelial cells (A549). In this study, we investigated the role of the MEK kinase (MEKK)1/ERK/p90 ribosomal S6 kinase (RSK)1–dependent C/EBPβ signaling pathway in thrombin-induced IL-8/CXCL8 expression. Thrombin-induced IL-8/CXCL8 release and IL-8/CXCL8-luciferase activity were attenuated by small interfering RNA (siRNA) of C/EBPβ and by cells transfected with the C/EBPβ site mutation of the IL-8/CXCL8 construct. Moreover, thrombin-induced κB-luciferase activity was also inhibited by C/EBPβ siRNA. The thrombin-induced increases in IL-8/CXCL8 release and IL-8/CXCL8-luciferase were also inhibited by MEKK1 siRNA, PD98059 (an MEK inhibitor), U0126 (an ERK inhibitor), and RSK1 siRNA. Treatment of cells with thrombin caused an increase in C/EBPβ phosphorylation at Thr235, C/EBPβ-luciferase activity, recruitment of C/EBPβ to the IL-8/CXCL8 promoter, and C/EBPβ-specific DNA complex formation. Furthermore, thrombin-mediated C/EBPβ phosphorylation and C/EBPβ-luciferase activity were inhibited by MEKK1 siRNA, PD98059, and RSK1 siRNA. Stimulation of cells with thrombin resulted in an increase in RSK1 phosphorylation at Thr359/Ser363, and this effect was inhibited by MEKK1 siRNA and PD98059. The thrombin-induced increase in ERK activation was inhibited by MEKK1 siRNA. These results imply that thrombin activates the MEKK1/ERK/RSK1 signaling pathway, which in turn initiates C/EBPβ activation, recruitment of C/EBPβ to the IL-8/CXCL8 promoter, and C/EBPβ-specific DNA complex formation, and ultimately induces IL-8/CXCL8 expression and release in lung epithelial cells.