Alpha or beta human chorionic gonadotropin knockdown decrease BeWo cell fusion by down-regulating PKA and CREB activation

• Published in: Scientific reports Vol. 5; no. 1; p. 11210
• Main Authors: Saryu Malhotra, Sudha, Suman, Pankaj, Kumar Gupta, Satish
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 08.06.2015; Nature Publishing Group
• Subjects: 13; 13/109; 14/63; 38/77; 631/45; 631/80/86; 82; 82/29; Androgens; beta Catenin - metabolism; Cell Fusion; Cell lines; Chorionic gonadotropin; Chorionic Gonadotropin, beta Subunit, Human - genetics; Colforsin - pharmacology; Cyclic AMP response element-binding protein; Cyclic AMP Response Element-Binding Protein - metabolism; Cyclic AMP-Dependent Protein Kinases - antagonists & inhibitors; Cyclic AMP-Dependent Protein Kinases - metabolism; Down-Regulation; Enzyme Activation - genetics; Extracellular Signal-Regulated MAP Kinases - metabolism; Forskolin; Gene Products, env - biosynthesis; Glycoprotein Hormones, alpha Subunit - genetics; Gonadotropins; Humanities and Social Sciences; Humans; Immunofluorescence; Isoquinolines - pharmacology; Kinases; multidisciplinary; p38 Mitogen-Activated Protein Kinases - metabolism; Phosphorylation; Phosphorylation - genetics; Pituitary (anterior); Polymerase chain reaction; Pregnancy Proteins - biosynthesis; Protein kinase A; Protein Kinase Inhibitors - pharmacology; RNA Interference; RNA, Small Interfering - genetics; Science; Sulfonamides - pharmacology; Syncytin; Syndecan; Syndecan-1 - biosynthesis; Trophoblasts - physiology; Western blotting; Wnt protein; β-Catenin
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep11210

The aim of the present study is to delineate the role of human chorionic gonadotropin (hCG) in trophoblast fusion. In this direction, using shRNA lentiviral particles, α- and β-hCG silenced ‘BeWo’ cell lines were generated. Treatment of both α- and β-hCG silenced BeWo cells with either forskolin or exogenous hCG showed a significant reduction in cell fusion as compared with control shRNA treated cells. Studies by qRT-PCR, Western blotting and immunofluorescence revealed down-regulation of fusion-associated proteins such as syncytin-1 and syndecan-1 in the α- and β-hCG silenced cells. Delineation of downstream signaling pathways revealed that phosphorylation of PKA and CREB were compromised in the silenced cells whereas, no significant changes in p38MAPK and ERK1/2 phosphorylation were observed. Moreover, β-catenin activation was unaffected by either α- or β-hCG silencing. Further, inhibition of PKA by H89 inhibitor led to a significant decrease in BeWo cell fusion but had no effect on β-catenin activation suggesting the absence of non-canonical β-catenin stabilization via PKA. Interestingly, canonical activation of β-catenin was associated with the up-regulation of Wnt 10b expression. In summary, this study establishes the significance of hCG in the fusion of trophoblastic BeWo cells, but there may be additional factors involved in this process.