CD40 plays an important role in the pathogenesis of Graves' disease (GD). Inhibition of CD40 expression may be a promising treatment for GD. In this study, we used an animal model to investigate whether lentivirus expressing siRNA for CD40 (LV-CD40-siRNA) could be useful for the therapy of GD. BALB/c mice were injected with PBS alone (PBS group), negative lentivirus (control siRNA group), or LV-CD40-siRNA (CD40 siRNA group), 3 days before being treated with adenovirus expressing human TSHR A subunit (Ad-TSHR289) three times at 3-week intervals to induce GD model. Sera thyroxine (T4) levels were assayed by RIA. The expression of CD40 was detected at the mRNA level by real-time PCR and protein level by flow cytometry. The expression of CD40, CD80, and CD86 was significantly decreased in the CD40 siRNA group (P<0.05), while FOXP3 expression was increased compared to the control siRNA group (P=0.05). Mean T4 levels were decreased 14% in the CD40 siRNA group compared to the control siRNA group. The rate of disease induction was similar among the three groups injected with Ad-TSHR289. LV-CD40-siRNA is a useful tool to inhibit the expression of CD40 in vivo, but it cannot decrease the incidence of hyperthyroidism in a limited period of time.
Feng Ye, Bingyin Shi, Xiaoyan Wu, Peng Hou, Lei Gao, Xiaodan Ma, Li Xu and Liping Wu
Yue Yu, Rui Guo, Yunjin Zhang, Hongbo Shi, Haoran Sun, Xia Chu, Xiaoyan Wu, Huimin Lu and Changhao Sun
Chronic exposure of pancreatic β-cells to saturated fatty acid (palmitic or stearic acid) is a leading cause of impaired insulin secretion. However, the molecular mechanisms underlying stearic-acid-induced β-cell dysfunction remain poorly understood. Emerging evidence indicates that miRNAs are involved in various biological functions. The aim of this study was to explore the differential expression of miRNAs and mRNAs, specifically in stearic-acid-treated- relative to palmitic-acid-treated β-cells, and to establish their co-expression networks. β-TC-6 cells were treated with stearic acid, palmitic acid or normal medium for 24 h. Differentially expressed miRNAs and mRNAs were identified by high-throughput sequencing and bioinformatic analysis. Co-expression network, gene ontology (GO) and pathway analyses were then conducted. Changes in the expression of selected miRNAs and mRNAs were verified in β-TC-6 cells and mouse islets. Sequencing analysis detected 656 known and 1729 novel miRNAs. miRNA-mRNA network and Venn-diagram analysis yielded two differentially expressed miRNAs and 63 mRNAs exclusively in the stearic-acid group. miR-374c-5p was up-regulated by a 1.801 log2(fold-change) and miR-297b-5p was down-regulated by a −4.669 log2(fold-change). We found that miR-297b-5p and miR-374c-5p were involved in stearic-acid-induced lipotoxicity to β-TC-6 cells. Moreover, the effects of miR-297b-5p and miR-374c-5p on the alterations of candidate mRNAs expressions were verified. This study indicates that expression changes of specific miRNAs and mRNAs may contribute to stearic-acid-induced β-cell dysfunction, which provides a preliminary basis for further functional and molecular mechanism studies of stearic-acid-induced β-cell dysfunction in the development of type 2 diabetes.