Effects of Baicalin on the Gene Expression of Surfactant Protein A (SP-A) in Lung Adenocarcinoma Cell Line H441

Abstract

Pulmonary surfactant, a complex lipoprotein, is secreted by alveolar type II cells. It lies at the alveolar air-fluid interface and prevents alveolar collapse by reducing surface tension. The high incidence of respiratory distress syndrome (RDS) in premature infants results principally from a deficiency of pulmonary surfactant. Surfactant protein A (SP-A) is the most abundant surfactant protein and reduces surface tension at the alveolar air-liquid interface in lung cells. In this study, RT-PCR and Western blot analyses of SP-A were performed to evaluate the biological activity of baicalin, a Chinese medicine prescribed extensively for preventing miscarriage. In in vitro experiments, lung adenocarcinoma cell line H441 was cultured with baicalin in varying concentrations and for varying lengths of time. The results show that the expression of SP-A gene was positively affected by baicalin in dose-dependent and time-course manners. The maximal expression of the SP-A gene, 1.7-fold greater than control, is induced at 150 nM of baicalin treated for 48 h.

Abbreviations

SP:surfactant protein

RDS:respiratory distress syndrome

IFN-γ:insulin, interferon gamma

TGF-β1:transforming growth factor β1

db-cAMP:dibutyryl adenosine 3′,5′-monophosphate

RT-PCR:reverse transcription-polymerase chain reaction

Key words

Scutellaria baicalensis - Lamiaceae - surfactant protein A - baicalin - traditional Chinese medicine - gene expression

References

• 1 Rooney S A, Young S L, Mendelson C R. Molecular and cellular processing of lung surfactant.  FASEB J. 1994;  8 957-67
• 2 Schagat T L, Wofford J A, Wright J R. Surfactant protein A enhances alveolar macrophage phagocytosis of apoptotic neutrophils.  J of Immunol. 2001;  166 2727-33
• 3 Khubchandani K R, Snyer J M. Surfactant protein A (SP-A): the alveolus and beyond.  FASEB J. 2001;  15 59-69
• 4 Saitoh H, Shimura S, Fushimi T, Okayama H, Shirato K. Detection of surfactant protein-A gene transcript in the cells from pleural effusion for the diagnosis of lung adenocarcinoma.  Am J Med. 1997;  103 400-4
• 5 Beers M F, Solarin K O, Guttentag S H, Rosenbloom J, Kormilli A, Gonzales L W, Ballard P L. TGF-β1 inhibits surfactant component expression and epithelial cell maturation in cultured human fetal lung.  Am J Physiol. 1998;  275 L950-60
• 6 Ballard P L, Liley H G, Gonzales L W, Odom M W, Ammann A J, Benson B, White R T, Williams M C. Interferon-gamma and synthesis of surfactant components by cultured human fetal lung.  American Journal of Respiratory and Cell Mol Biol. 1990;  2 137-43
• 7 Odom M J, Snyder J M, Boggaram V, Mendlson C R. Glucocorticoid regulation of the major surfactant associated protein (SP-A) and its messenger ribonucleic acid and of morphological development of human fetal lung in vitro .  Endocrinology. 1988;  123 1712-20
• 8 O’Reilly M A, Gazdar A F, Morris R E, Whitsett J A. Differential effects of glucocorticoid on expression of surfactant proteins in a human lung adenocarcinoma cell line.  Biochim Biophys Acta. 1988;  970 194-204
• 9 Scavo L M, Ertsey R, Gao B Q. Human surfactant proteins A1 and A2 are differentially regulated during development and by soluble factors.  Am J Physiol. 1998;  275 L653-69
• 10 Hoover R R, Thomas K H, Floros J. Glucocorticoid inhibition of human SP-A1 promoter activity in NCI-H441 cells.  Biochem J. 1999;  340 69-76
• 11 Crowley P A. Antenatal corticosteroid therapy: a meta-analysis of the randomized trials, 1972 - 1994.  Am J Obstet Gynecol. 1995;  173 322-35
• 12 Murphy B P, Inder T E, Huppi P S, Warfield S, Zientara G P, Kikinis R, Jolesz F A, Volpe J J. Impaired cerebal cortical gray matter growth after treatment with dexamethasone for neonatal chronic lung disease.  Pediatrics. 2001;  107 217-21
• 13 Shinwell E S, Karplus M, Reich D, Weintraub Z, Blazer S, Bader D, Yurman S, Dolfin T, Kogan A, Dollberg S, Arbel E, Goldberg M, Gur I, Naor N, Sirota L, Mogilne S, Zaritsky A, Barak M, Gottfried E. Early postnatal dexamethasone treatment and increased incidence of cerebral palsy.  Arch Dis Child Fetal Neonatal Ed. 2000;  83 F177-81
• 14 Chung C P, Park J B, Bae K H. Pharmacological effects of methanolic extract from the root of Scutellaria baicalensis and its flavonoids on human gingival fibroblast.  Planta Medica. 1995;  61 150-3
• 15 Huang K C. The Pharmacology of Chinese Herbs. 2nd edition Florida; CRC Press 1999: pp. 385-6
• 16 Motoo Y, Sawabu N. Antitumor effects of saikosaponins, baicalin and baicalein, on human hepatoma cell lines.  Cancer Lett.. 1994;  86 91-5
• 17 Ikezoe T, Chen S S, Heber D, Taguchi H, Koeffler H P. Baicalin is a major component of PC-SPES which inhibits the proliferation of human cancer cells via apoptosis and cell cycle arrest.  Prostate. 2001;  49 285-92
• 18 Kumar A R, Snyder J M. Differential regulation of SP-A1 and SP-A2 genes by cAMP, glucocorticoids, and insulin.  Am J Physiol. 1998;  274 L177-85
• 19 Gao E, Wang Y, Alcorn J L, Mendelson C R. The basic helix-loop-helix-zipper transcription factor USF1 regulates expression of the surfactant protein-A gene.  J Biol Chem. 1997;  272 23 398-406
• 20 Bry K, Lappalainen U. Intra-amniotic endotoxin accelerates lung maturation in fetal rabbits.  Acta Pediatrics. 2001;  90 74-80