Modulation of miR-185-5p expression by EBV-miR-BART6 contributes to developmental differences in ABCG4 gene expression in human megakaryocytes.
Immune thrombocytopenia (ITP) is an acquired autoimmune disorder characterized by low platelet count and bleeding, and is usually triggered by viral infections. We previously reported that 14 viral microRNAs of megakaryocytes cultured with serum from patients with ITP, including ebv-miR-BART6, are up-regulated. Previous research has reported that ebv-miR-BART6 down-regulated the expression of miR-185-5p. We therefore predicted that the ABCG4 gene, which is highly expressed in megakaryocyte progenitor cells, is a direct target of miR-185-5p. We hypothesized that ebv-miR-BART6 may play a role in development and differentiation of megakaryocytes. First, we verified the negative regulation of ABCG4 by miR-185-5p through luciferase assay analysis. Second, after transfection of ebv-miR-BART6 into megakaryocytes developing from normal cord blood mononuclear cells (MNCs), we found that the level of miR-185-5p in the ebv-miR-BART6 group was reduced to almost a third of that in the control groups, accompanied by up-regulation of ABCG4 at both the mRNA and protein levels. Meanwhile, proliferation of megakaryocytes was significantly repressed in the ebv-miR-BART6 group compared with the blank and negative control groups (14.89%±3.13%, 34.15%±2.42% and 30.96%±4.37%, respectively; P<0.001). Our results further revealed that ebv-miR-BART6 inhibited megakaryocyte colony unit formation, decreased CD41 expression and inhibited megakaryocyte polyploidization. These data suggest a new paradigm to explain the mechanisms underlying ITP, involving the regulation of megakaryocytopoiesis by viral microRNAs through the intronic hsa-microRNA.
Department of Oncology, Shanghai Sixth People's Hospital, Shanghai JiaoTong University, No 600 Yishan Road, Xuhui, Shanghai, 200233, China; Department of Hematology, Zhujiang Hospital, Southern Medical University, No 253 Industrial Avenue, Haizhu, Guangzhou, Guangdong 501282, China.
Lan
L
Deng
Department of Hematology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China; Key Laboratory of Malignant Tumor Gene Regulation and Target Therapy of Guangdong Higher Education Institutes, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, No 170 Yanjiang Road, Yuexiu, Guangzhou, Guangdong 510120, China.
Xiuju
X
Wang
Department of Hematology, Nanfang Hospital, Southern Medical University, No 1838 North of Guangzhou Avenue, Baiyun, Guangzhou 510515, China.
Ling
L
Jiang
Department of Oncology, Shanghai Sixth People's Hospital, Shanghai JiaoTong University, No 600 Yishan Road, Xuhui, Shanghai, 200233, China.
Jilong
J
Yang
Department of Oncology, Shanghai Sixth People's Hospital, Shanghai JiaoTong University, No 600 Yishan Road, Xuhui, Shanghai, 200233, China.
Xuan
X
Zhou
Department of Hematology, Zhujiang Hospital, Southern Medical University, No 253 Industrial Avenue, Haizhu, Guangzhou, Guangdong 501282, China. Electronic address: ZhigangLu_zhujiang@126.com.
Zhigang
Z
Lu
Department of Oncology, Shanghai Sixth People's Hospital, Shanghai JiaoTong University, No 600 Yishan Road, Xuhui, Shanghai, 200233, China. Electronic address: xuri1104@163.com.
Haiyan
H
Hu
D020413:3' Untranslated Regions / Q000235:genetics; D000070996:ATP Binding Cassette Transporter, Subfamily G / Q000235:genetics*; D049109:Cell Proliferation / Q000235:genetics; D015536:Down-Regulation / Q000235:genetics; D005260:Female; D005786:Gene Expression Regulation / Q000235:genetics*; D004854:Herpesvirus 4, Human / Q000235:genetics*; D006801:Humans; D008533:Megakaryocytes / Q000166:cytology* / Q000378:metabolism*; D035683:MicroRNAs / Q000235:genetics*; D011247:Pregnancy; D012367:RNA, Viral / Q000235:genetics*
D020413:3' Untranslated Regions; C439766:ABCG4 protein, human; D000070996:ATP Binding Cassette Transporter, Subfamily G; C552431:MIRN185 microRNA, human; D035683:MicroRNAs; D012367:RNA, Viral
ATP-binding cassette sub-family G member 4; Epstein-Barr virus; Megakaryocyte; MicroRNA; MicroRNA-185-5p