Increased TMEM16A Involved in Alveolar Fluid Clearance After Lipopolysaccharide Stimulation
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Transmembrane protein 16A (TMEM16A) regulates a wide variety of cellular activities, including epithelial fluid secretion and maintenance of ion homeostasis. Lipopolysaccharide (LPS), an outer membrane component of Gram-negative bacteria, is one of the major causes of acute lung injury (ALI). In this study, we investigated the effects of LPS on the expression of TMEM16A in LA795 cells and mouse lung tissue and the potential mechanism. Result: We detected the expression of TMEM16A in LA795 cells and mouse lung tissue by RT-PCR, Western blot, and RNA interference techniques. TMEM16A expression was significantly increased by LPS stimulation in LA795 cells and in mouse lung tissue. Moreover, the LPS-induced TMEM16A expression enhancement in lung tissue was much more prominent in the alveolar epithelial region than in bigger airway epithelial cells. The typical TMEM16A current was recorded, and LPS treatment significantly enhances the current amplitude in LA795 cells. TMEM16A shRNA or TMEM16A inhibitor (T16Ainh-A01) did not affect alveolar fluid clearance (AFC), while co-application of T16Ainh-A01 induced a stronger AFC inhibition than LPS alone. LPS notably and synchronously enhanced Akt phosphorylation (p-Akt) and TMEM16A expression in a time-dependent manner in LA795 cells. Taken together, our results suggest that TMEM16A maybe plays an important role in pathological conditions of LPS-induced ALI as a protective protein.
KEY WORDSTMEM16A lipopolysaccharide alveolar fluid clearance acute lung injury p-Akt
Transmembrane protein 16A
Acute lung injury
Alveolar fluid clearance
We thank technicians Bin Li M.D. Ph.D. and Ping Xue M.D. for their technical assistance and Prof. Yi Zhang M.D. Ph.D. and Prof. Hailin Zhang M.D. Ph.D. for providing valuable suggestions.
Compliance with Ethical Standards
The use of wild-type C57BL/6 mice was approved by the Animal Care and Ethics Committee of Hebei Medical University.
Conflict of Interest
The authors declare that they have no conflicts of interest.
This work was supported by the National Nature Science Foundation of China (grant no. 81170063) and the Nature Science Foundation of Hebei Province, China (grant no H2012206110).
- 7.Ruffin, M., M. Voland, S. Marie, M. Bonora, E. Blanchard, S. Blouquit-Laye, E. Naline, P. Puyo, P. Le Rouzic, L. Guillot, H. Corvol, A. Clement, and O. Tabary. 2013. Anoctamin 1 dysregulation alters bronchial epithelial repair in cystic fibrosis. Biochimica et Biophysica Acta 1832: 2340–2351.CrossRefPubMedGoogle Scholar
- 9.Liu, B., J.E. Linley, X. Du, X. Zhang, L. Ooi, H. Zhang, and N. Gamper. 2010. The acute nociceptive signals induced by bradykinin in rat sensory neurons are mediated by inhibition of M-type K+ channels and activation of Ca2+-activated Cl- channels. Journal of Clinical Investigation 120: 1240–1252.CrossRefPubMedPubMedCentralGoogle Scholar
- 11.Huang, F., J.R. Rock, B.D. Harfe, T. Cheng, X. Huang, Y.N. Jan, and L.Y. Jan. 2009. Studies on expression and function of the TMEM16A calcium-activated chloride channel. Proceedings of the National Academy of Sciences of the United States of America 106: 21413–21418.CrossRefPubMedPubMedCentralGoogle Scholar
- 15.Huang, F., H. Zhang, M. Wu, H. Yang, M. Kudo, C.J. Peters, P.G. Woodruff, O.D. Solberg, M.L. Donne, X. Huang, D. Sheppard, J.V. Fahy, P.J. Wolters, B.L. Hogan, W.E. Finkbeiner, M. Li, Y.N. Jan, L.Y. Jan, and J.R. Rock. 2012. Calcium-activated chloride channel TMEM16A modulates mucin secretion and airway smooth muscle contraction. Proceedings of the National Academy of Sciences of the United States of America 109: 16354–16359.CrossRefPubMedPubMedCentralGoogle Scholar
- 17.Veit, G., F. Bossard, J. Goepp, A.S. Verkman, L.J. Galietta, J.W. Hanrahan, and G.L. Lukacs. 2012. Proinflammatory cytokine secretion is suppressed by TMEM16A or CFTR channel activity in human cystic fibrosis bronchial epithelia. Molecular Biology of the Cell 23: 4188–4202.CrossRefPubMedPubMedCentralGoogle Scholar
- 18.Forrest, A.S., T.C. Joyce, M.L. Huebner, R.J. Ayon, M. Wiwchar, J. Joyce, N. Freitas, A.J. Davis, L. Ye, D.D. Duan, C.A. Singer, M.L. Valencik, I.A. Greenwood, and N. Leblanc. 2012. Increased TMEM16A-encoded calcium-activated chloride channel activity is associated with pulmonary hypertension. American Journal of Physiology. Cell Physiology 303: C1229–C1243.CrossRefPubMedPubMedCentralGoogle Scholar
- 21.Y. Yang, Y. Cheng, Q.Q. Lian, L. Yang, W. Qi, D.R. Wu, X. Zheng, Y.J. Liu, W.J. Li, S.W. Jin, and F.G. Smith, Contribution of CFTR to alveolar fluid clearance by lipoxin A4 via PI3K/Akt pathway in LPS-induced acute lung injury. Mediators of Inflammation (2013) 862628.Google Scholar
- 22.Mutlu, G.M., Y. Adir, M. Jameel, A.T. Akhmedov, L. Welch, V. Dumasius, F.J. Meng, J. Zabner, C. Koenig, E.R. Lewis, R. Balagani, G. Traver, J.I. Sznajder, and P. Factor. 2005. Interdependency of beta-adrenergic receptors and CFTR in regulation of alveolar active Na+ transport. Circulation Research 96: 999–1005.CrossRefPubMedGoogle Scholar
- 23.Factor, P., G.M. Mutlu, L. Chen, J. Mohameed, A.T. Akhmedov, F.J. Meng, T. Jilling, E.R. Lewis, M.D. Johnson, A. Xu, D. Kass, J.M. Martino, A. Bellmeyer, J.S. Albazi, C. Emala, H.T. Lee, L.G. Dobbs, and S. Matalon. 2007. Adenosine regulation of alveolar fluid clearance. Proceedings of the National Academy of Sciences of the United States of America 104: 4083–4088.CrossRefPubMedPubMedCentralGoogle Scholar
- 24.Suda, K., M. Tsuruta, J. Eom, C. Or, T. Mui, J.E. Jaw, Y. Li, N. Bai, J. Kim, J. Man, D. Ngan, J. Lee, S. Hansen, S.W. Lee, S. Tam, S.P. Man, S. Van Eeden, and D.D. Sin. 2011. Acute lung injury induces cardiovascular dysfunction: effects of IL-6 and budesonide/formoterol. American Journal of Respiratory Cell and Molecular Biology 45: 510–516.CrossRefPubMedGoogle Scholar
- 25.Buyck JM1, Verriere V, Benmahdi R, Higgins G, Guery B, Matran R, Harvey BJ, Faure K, Urbach V, P. aeruginosa LPS stimulates calcium signaling and chloride secretion via CFTR in human bronchial epithelial cells. Journal of Cystic Fibrosis 12 (2013)60-7.Google Scholar
- 26.Wilson, A.A., L.W. Kwok, E.L. Porter, J.G. Payne, G.S. McElroy, S.J. Ohle, S.R. Greenhill, M.T. Blahna, K. Yamamoto, J.C. Jean, J.P. Mizgerd, and D.N. Kotton. 2013. Lentiviral delivery of RNAi for in vivo lineage-specific modulation of gene expression in mouse lung macrophages. Molecular Therapy 21: 825–833.CrossRefPubMedPubMedCentralGoogle Scholar
- 31.Berger, G., J. Guetta, G. Klorin, R. Badarneh, E. Braun, V. Brod, N.A. Saleh, A. Katz, H. Bitterman, and Z.S. Azzam. 2011. Sepsis impairs alveolar epithelial function by downregulating Na-K-ATPase pump. American Journal of Physiology - Lung Cellular and Molecular Physiology 301: L23–L30.CrossRefPubMedGoogle Scholar