Original Article
Copyright ©2013 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Feb 28, 2013; 19(8): 1230-1238
Published online Feb 28, 2013. doi: 10.3748/wjg.v19.i8.1230
Schistosoma japonicum egg antigen up-regulates fibrogenesis and inhibits proliferation in primary hepatic stellate cells in a concentration-dependent manner
Ping Liu, Mi Wang, Xiao-Dan Lu, Shu-Juan Zhang, Wang-Xian Tang
Ping Liu, Mi Wang, Xiao-Dan Lu, Shu-Juan Zhang, Wang-Xian Tang, Institute of Liver Diseases, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China
Author contributions: Liu P performed the majority of the experiments; Wang M, Lu XD and Zhang SJ coordinated the study and provided analytical tools; Liu P and Wang M designed the experiments; Liu P and Tang WX wrote the manuscript.
Supported by Natural Science Foundation of China, No. 81071381
Correspondence to: Wang-Xian Tang, Professor, Institute of Liver Diseases, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jie-Fang Avenue, Wuhan 430030, Hubei Province, China. tangwx@tjh.tjmu.edu.cn
Telephone: +86-27-83662873 Fax: +86-27-83662640
Received: September 14, 2012
Revised: December 27, 2012
Accepted: January 23, 2013
Published online: February 28, 2013
Processing time: 175 Days and 19.8 Hours
Abstract

AIM: To investigate the effects of different concentrations of Schistosoma japonicum (S. japonicum) egg antigen on fibrogenesis and apoptosis in primary hepatic stellate cells (HSCs).

METHODS: A mouse model of schistosomiasis-associated liver fibrosis (SSLF) was established by infecting mice with schistosomal cercaria via the abdomen. HSCs were isolated from SSLF mice by discontinuous density gradient centrifugation, and their identity was confirmed by immunofluorescence double staining of α-smooth muscle actin (α-SMA) and desmin. The growth inhibitory effect and 50% inhibitory concentration (IC50) of S. japonicum egg antigen for primary HSCs (24 h) were determined using a cell counting kit-8 (CCK-8) assay. The expression levels of α-SMA, matrix metalloproteinase-9 (MMOL/LP-9) and tissue inhibitor of metalloproteinases-1 (TIMP-1) in HSCs in response to different concentrations of S. japonicum egg antigen were detected by Western blotting and real-time reverse transcription-polymerase chain reaction. The levels of phospho-P38 (P-P38), phospho-Jun N-terminal kinase (P-JNK) and phospho-Akt (P-AKT) in HSCs were detected by Western blotting.

RESULTS: An SSLF mouse model was established, and primary HSCs were successfully isolated and cultured. S. japonicum egg antigen inhibited HSC proliferation in a concentration-dependent manner. The IC50 of the S. japonicum egg antigen was 244.53 ± 35.26 μg/mL. S. japonicum egg antigen enhanced α-SMA expression at both the mRNA and protein levels and enhanced TIMP-1 expression at the mRNA level in HSCs (P < 0.05), whereas the expression of MMOL/LP-9 was attenuated at both the mRNA and protein levels in a concentration-dependent manner (P < 0.05). A high concentration of S. japonicum egg antigen enhanced P-P38, P-JNK and P-AKT activation (P < 0.05). The changes in α-SMA and MMOL/LP-9 expression induced by S. japonicum egg antigen were closely correlated with P-P38 and P-JNK activation (P < 0.05). The attenuation of MMOL/LP-9 was also correlated with P-AKT activation (P < 0.05), but the increase in α-SMA expression was not. TIMP-1 expression was not correlated with P-P38, P-JNK or P-AKT activation.

CONCLUSION: S. japonicum egg antigen promotes fibrogenesis, activates the P38/JNK mitogen-activated protein kinase and AKT/PI3K signaling pathways and inhibits proliferation in primary HSCs isolated from SSLF mice in a concentration-dependent manner.

Keywords: Schistosomiasis; Liver fibrosis; Hepatic stellate cells; Mitogen-activated protein kinase; Akt