Liver X receptor agonist T0901317 inhibits TGF-β1-induced α-SMA expression in normal human lung fibroblasts / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of liver X receptor agonist T0901317 on transforming growth factor-β1 (TGF-β1)-induced expression of α-smooth muscle actin (α-SMA) in normal human lung fibroblasts.</p><p><b>METHODS</b>Primary normal human lung fibroblast isolated from the lung specimens of lung cancer patients by explant culture technique were identified with immunostaining for vimentin and keratin. The cells in passages 4 to 10 were treated with T0901317 and/or TGF-β1, and RT-PCR, Western blotting and immunofluorescence assay were used to detect α-SMA expression in the fibroblasts.</p><p><b>RESULTS</b>Lung fibroblast expressed vimentin but not keratin. The results of RT-PCR, Western blotting and immunofluorescence assay all showed that normal human lung fibroblasts constitutively expressed α-SMA under baseline condition, and TGF-β1 at 5 ng/ml induced a significant upregulation of α-SMA both at the mRNA and protein levels. Liver X receptor agonist T0901317 (5 µg/ml) significantly inhibited TGF-β1-induced upregulation of α-SMA expression.</p><p><b>CONCLUSION</b>Liver X receptor agonist T0901317 can inhibit the upregulation of α-SMA in normal human lung fibroblasts induced by TGF-β1, suggesting the potential value of liver X receptor agonist in the treatment of lung fibrosis.</p>

Change of IL-22R1 expression in human airway smooth muscle cells in response to different stimulating agents / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the effects of serum of asthmatic patients, dexamethasone, interleukin-4 (IL-4), interferon-gamma (IFN-γ) and transforming growth factor-β (TGF-β) on the expression of interleukin-22 receptor 1 (IL-22R1) mRNA and protein in HASMCs in vitro.</p><p><b>METHODS</b>IL-22R1 mRNA and protein expressions in HASMCs treated with different stimulating agents were measured by real-time PCR and Western blotting, respectively.</p><p><b>RESULTS</b>IL-22R1 mRNA and protein expressions in HASMCs were significantly increased after stimulation by serum from asthmatic patients, but decreased after co-stimulation with dexamethasone. IL-22R1 mRNA and protein expressions in the cells both increased after stimulation by IL-4, IFN-γ and TGF-β.</p><p><b>CONCLUSION</b>IL-22R1 in HASMCs might be involved in the pathogenesis of asthma, and the therapeutic effect of dexamethasone on asthma is mediated, at least partially, by IL-22R1. The effects of IFN-γ, IL-4, and TGF-β on asthma may also be attributed to their actions on HASMCs.</p>

Shikonin inhibits the proliferation of human airway smooth muscle cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the inhibitory effect of shikonin on the proliferation of human airway smooth muscle cells (HASMCs) in vitro.</p><p><b>METHODS</b>HASMCs from the trachea were obtained by primary culture of the tissue explants and adherent culture. The HASMCs were exposed to shikonin at 0 (control group), 0.5, 1, 2, 5, 10, 20, and 40 micromol/L for 12, 24, and 48 h, after which the cell proliferation was assessed by 3-(4,5-carboxymethoxypheny1)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) colorimetric assay. Flow cytometry was used for cell cycle analysis of the HASMCs exposed to shikonin at 40, 20, 10, 5 micromol/L and 0 micromol/L (control group) for 24 h. Immunocytochemistry with SP method was performed to detect the expression of proliferating cell nuclear antigen (PCNA) in the HASMCs treated with shikonin at 20 micromol/L and 0 micromol/L (control group) for 24 h.</p><p><b>RESULTS</b>Shikonin at the concentrations of 20 and 40 micromol/L significantly inhibited the proliferation of the cells (P<0.05), and the effect was especially obvious after 48 h of cell exposure, with inhibition rates of 30.1% and 42.9%, respectively. No significant difference was found between the two concentrations for their cell growth inhibition effects (P>0.05). Shikonin at the concentrations of 20 and 40 micromol/L caused significant cell cycle arrest in G(0)/G(1) phase (P<0.05), the effect of which, however, was not concentration-dependent (P>0.05). Shikohin at 20 micromol/L significantly down-regulated the expression of PCNA in the cells (P<0.05).</p><p><b>CONCLUSION</b>Shikonin can inhibit the proliferation of HASMCs in vitro.</p>

Rho-kinase signaling pathway participates in endothelin-1-induced human airway smooth muscle cell migration and cytoskeletal reorganization / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the role of Rho-kinase signaling pathway in human airway smooth muscle cell (ASMCs) migration and cytoskeletal reorganization induced by endothelin-1 (ET-1).</p><p><b>METHODS</b>Primary cultured human ASMCs obtained by tracheal explant culture method were examined for cell migration in response to ET-1 treatment using modified Boyden chambers. The changes in actin cytoskeletal reorganization were observed under confocal laser scanning microscope, and the phosphorylation of myosin-phosphatase target 1 (p-MYPT1) was examined using Western blot analysis.</p><p><b>RESULTS</b>At the concentration of 0.1, 1, 10, and 100 nmol/L, ET-1 induced migration of the ASMCs, and 10 nmol/L ET-1 produced the most obvious effect (P<0.01). Rho-kinase inhibitor Y-27632 showed a dose-dependent inhibitory effect on ET-1-induced ASMC migration, and in cells exposed to 10 nmol/L ET-1, Y-27632 at 10 micromol/L significantly blocked ASMC migration (P<0.01). ET-1 (10 nmol/L) exposure resulted in reorganization of actin cytoskeleton and formation of stress fibers in the ASMCs, which were obviously inhibited by Y-27632. Compared with the control group, the AMSCs showed significant enhancement of p-MYPT1 protein expression after ET-1 exposure for 15 and 30 min (P<0.01), but prolonged exposure failed to result in the expression enhancement (P>0.05).</p><p><b>CONCLUSION</b>Rho-kinase signaling pathway may play an important role in ET-1-induced ASMC migration and reorganization of actin cytoskeleton.</p>