CHINESE JOURNAL OF PARASITOLOGY AND PARASITIC DISEASES ›› 2021, Vol. 39 ›› Issue (1): 48-54.doi: 10.12140/j.issn.1000-7423.2021.01.007

• ORIGINAL ARTICLES • Previous Articles     Next Articles

Investigation of differentially expressed genes in liver tissues of patients with alveolar echinococcosis

ZHU Ji-hai1(), CAO De-ping2, ZHAO Jun2, LIU Jun2, SHI Hu-xiang2, LIU Yan2,*()   

  1. 1 Qinghai University Affiliated Hospital, Xining 810001, China
    2 Medical College, Qinghai University, Xining 810001, China
  • Received:2020-07-27 Revised:2020-09-13 Online:2021-02-28 Published:2021-03-10
  • Contact: LIU Yan E-mail:zhujihai@126.com;543394169@qq.com
  • Supported by:
    National Natural Science Foundation of China(81960451);Natural Science Foundation of Qinghai Province Science and Technology Department(2017-ZJ-735)

Abstract:

Objective To investigate the expression profile of differentially expressed genes in liver lesions of alveolar echinococcosis patients, based on the findings that these genes were indentified in mice infected with alveolar metacestode. Methods The gene chip dataset (No. GSE24376) in the high-throughput gene expression database was selected from the gene expression omnibus (GEO), to compare the genes with differential expression between infected and uninfected mice. The differentially expressed genes underwent gene ontology (GO) analysis. Lesion tissues and adjacent tissues 2 cm from the lesion were collected from 6 patients with E. multilocularis cyst infection. Fluorescence quantitative PCR was performed to detect the relative mRNA levels of two highly expressed differential genes. Forty-five paraffin-embedded liver tissue samples from patients with multilocular hydatid infection (29 samples with severe inflammatory response and liver fibrosis, and 16 with relatively normal liver tissue with less inflammatory cell infiltration and liver fibrosis) underwent immunohistochemistry to analyze the expression of the two highly expressed differential genes. Statistical analysis was performed on the data with SPSS 21.0 statistical software. Results As compared to the normal mice, 21 differentially expressed genes were found, including 9 overexpressed genes and 12 downregulated genes in liver tissues of infected mice. The results of GO analysis showed that the differentially expressed genes were expressed in vesicle lumen, cytoplasmic vesicle lumen and extracellular matrix, participated in biological processes of neutrophil degranulation and activation, and possessed CC chemokine receptor binding activity and chemokine activity. The fluorescence quantitative PCR results showed that the mRNA expression levels of CHI3L3 (CHI3L1 in humans) and CCL8, which had higher differential expression, were higher in the liver lesion tissues than in the surrounding tissues of the 6 patients with multilocular hydatid infection (P < 0.01), reaching an utmost 7 and 9 folds, respectively. The results of immunohistochemistry showed that among the 29 lesion samples with severe inflammatory reaction and liver fibrosis, 20 samples (69%) showed high expression of CHI3L1 protein, with staining mainly located in the cytoplasm, and 22 samples showed high levels of CCL8 protein (76%). Of the 16 relatively normal liver tissue samples, only 2 (13%) were positive for CHI3L1 protein, and only 4 were positive for CCL8 protein (33%). In the lesions with severe inflammatory response and liver fibrosis, the positive expression rate of CHI3L1 and CCL8 proteins reached 96% and 97%, respectively, which were higher than 3% and 8% in normal liver tissues (P < 0.01). Conclusion The expression of CHI3L1 and CCL8 was upregulated in the liver tissues of patients with E. multilocularis, suggesting that they play a role in the immune response to parasites.

Key words: Echinococcus multilocularis, Infection, Differentially expressed genes, CHI3L3, CCL8

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