Transforming growth factor-β utilizes a multitude of intracellular signaling pathways in addition to Smads to regulate a wide array of cellular functions. These non-canonical, non-Smad pathways are activated directly...Transforming growth factor-β utilizes a multitude of intracellular signaling pathways in addition to Smads to regulate a wide array of cellular functions. These non-canonical, non-Smad pathways are activated directly by ligandoccupied receptors to reinforce, attenuate, or otherwise modulate downstream cellular responses. These non-Smad pathways include various branches of MAP kinase pathways, Rho-like GTPase signaling pathways, and phosphatidylinositol-3-kinase/AKT pathways. This review focuses on recent advances in the understanding of the molecular and biochemical mechanisms of non-Smad pathways. In addition, functions of these non-Smad pathways are also discussed.展开更多
Background Mucus hypersecretion in the respiratory tract and goblet cell metaplasia in the airway epithelium contribute to the morbidity and mortality associated with airway inflammatory diseases. This study aimed to ...Background Mucus hypersecretion in the respiratory tract and goblet cell metaplasia in the airway epithelium contribute to the morbidity and mortality associated with airway inflammatory diseases. This study aimed to examine the effect and mechanisms of simvastatin on airway mucus hypersecretion in rats treated with lipopolysaccharide （LPS）. Methods Mucus hypersecretion in rat airways was induced by intra-tracheal instillation of LPS. Rats treated with or without LPS were administered intra-peritoneally simvastatin （5 and 20 mg/kg） for 4 days. Expression of Muc5ac, RhoA and mitogen-activated protein kinases （MAPK） p38 in lung were detected by real-time polymerase chain reaction （PCR）, immunohistochemistry or Western blotting. Tumor necrosis factor （TNF）-α and IL-8 in bronchoalveolar lavage fluid （BALF） were assayed by an enzyme-linked lectin assay and enzyme linked immunosorbent assay （ELISA）. Results Simvastatin attenuated LPS-induced goblet cell hyperplasia in bronchial epithelium and Muc5ac hypersecretion at both the gene and protein levels in lung （P 〈0.05）. Moreover, simvastatin inhibited neutrophil accumulation and the increased concentration of TNF-α and IL-8 in BALF follows LPS stimulation （P 〈0.05）. The higher dose of simvastatin was associated with a more significant reduction in Muc5ac mRNA expression, neutrophil accumulation and inflammatory cytokine release. Simultaneously, the increased expression of RhoA and p38 MAPK were observed in LPS-treated lung （P 〈0.05）. Simvastatin inhibited the expression of RhoA and p38 phosphorylation in lung following LPS stimulation （P 〈0.05）. However, the increased expression of p38 protein in LPS-treated lung was not affected by simvastatin administration. Conclusions Simvastatin attenuates airway mucus hypersecretion and pulmonary inflammatory damage induced by LPS. The inhibitory effect of simvastatin on airway mucus hypersecretion may be through, at least in part, the suppression of neutrophil accumulation and 展开更多
文摘Transforming growth factor-β utilizes a multitude of intracellular signaling pathways in addition to Smads to regulate a wide array of cellular functions. These non-canonical, non-Smad pathways are activated directly by ligandoccupied receptors to reinforce, attenuate, or otherwise modulate downstream cellular responses. These non-Smad pathways include various branches of MAP kinase pathways, Rho-like GTPase signaling pathways, and phosphatidylinositol-3-kinase/AKT pathways. This review focuses on recent advances in the understanding of the molecular and biochemical mechanisms of non-Smad pathways. In addition, functions of these non-Smad pathways are also discussed.
基金This study was supported by grants from National Natural Science Foundation of China to Dr. WEN Fu-qing （No. 30425007, 30370627, 30670921） and from China Medical Board of New York to Dr. WEN Fu-qiang （No. 0-722）.
文摘Background Mucus hypersecretion in the respiratory tract and goblet cell metaplasia in the airway epithelium contribute to the morbidity and mortality associated with airway inflammatory diseases. This study aimed to examine the effect and mechanisms of simvastatin on airway mucus hypersecretion in rats treated with lipopolysaccharide （LPS）. Methods Mucus hypersecretion in rat airways was induced by intra-tracheal instillation of LPS. Rats treated with or without LPS were administered intra-peritoneally simvastatin （5 and 20 mg/kg） for 4 days. Expression of Muc5ac, RhoA and mitogen-activated protein kinases （MAPK） p38 in lung were detected by real-time polymerase chain reaction （PCR）, immunohistochemistry or Western blotting. Tumor necrosis factor （TNF）-α and IL-8 in bronchoalveolar lavage fluid （BALF） were assayed by an enzyme-linked lectin assay and enzyme linked immunosorbent assay （ELISA）. Results Simvastatin attenuated LPS-induced goblet cell hyperplasia in bronchial epithelium and Muc5ac hypersecretion at both the gene and protein levels in lung （P 〈0.05）. Moreover, simvastatin inhibited neutrophil accumulation and the increased concentration of TNF-α and IL-8 in BALF follows LPS stimulation （P 〈0.05）. The higher dose of simvastatin was associated with a more significant reduction in Muc5ac mRNA expression, neutrophil accumulation and inflammatory cytokine release. Simultaneously, the increased expression of RhoA and p38 MAPK were observed in LPS-treated lung （P 〈0.05）. Simvastatin inhibited the expression of RhoA and p38 phosphorylation in lung following LPS stimulation （P 〈0.05）. However, the increased expression of p38 protein in LPS-treated lung was not affected by simvastatin administration. Conclusions Simvastatin attenuates airway mucus hypersecretion and pulmonary inflammatory damage induced by LPS. The inhibitory effect of simvastatin on airway mucus hypersecretion may be through, at least in part, the suppression of neutrophil accumulation and
