THU0024 INHIBITION OF CELL PROLIFERATION AND PROMOTION OF INTERLEUKIN-8 PRODUCTION BY T-614 IN CULTURED HUMAN AORTIC ADVENTITIAL FIBROBLASTS
Authors: Weiping Ci, Tian Wang
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background</h3> Takayasu's arteritis (TA) is an inflammatory fibrosing arteritis that affects predominantly the aorta and its main branches. Recently, growing evidence supports that adventitial fibroblasts play an essential role in vascular inflammation [1].Tumor necrosis factor-α (TNF-α) can reportedly induce inflammation of vascular adventitial fibroblasts[2]. T-614(iguratimod), a novel disease-modifying antirheumatic drug, has been widely used in rheumatoid arthritis in China and Japan [3]. However, the effect and mechanism of T-614 on TA have received little attention. <h3>Objectives</h3> We report the effects of T-614 on cell proliferation and interleukin-8 (IL-8) production in cultured human aortic adventitial fibroblasts (HAAF), and explored its possible effect on the treatment of TA. <h3>Methods</h3> HAAF were cultured with 0, 5, 50, 100, or 250 μg/ml T-614 in the absence or presence of 10 ng/ml TNF-α in vitro. Cell viability of HAAF was determined by a modified MTT assay. Supernatant IL-8 level was measured by enzyme linked immunosorbent assay. <h3>Results</h3> (1)After subculture, HAAF were polygonal or spindle-shaped under the microscope (Figure 1A, B).(2)In the presence of TNF-α, compared with the contrast group, cell viability of HAAF significantly decreased in 50, 100, and 250 μg/ml T-614 treatment groups (OD value: <i>P</i>&lt;0.01, <i>P</i>&lt;0.001, <i>P</i>&lt;0.001, respectively; survival fraction (SF): <i>P</i>&lt;0.05, <i>P</i>&lt;0.001, <i>P</i>&lt;0.001, respectively) (Table I, Figure 2). However, there was no significant difference in cell viability between TNF-α stimulated and unstimulated groups at the same concentration of T-614. In the absence and presence of TNF-α, T-614 suppressed HAAF cell viability dose-dependently (OD value: <i>r</i> = -0.915, <i>P</i> =0.000 and<i> r</i> = -0.926, <i>P</i> =0.000, respectively; SF: <i>r</i> = -0.897,<i> P</i> =0.000; <i>r</i> = -0.885,<i> P</i> =0.000, respectively). (3)In the absence of TNF-α, compared with the contrast group, IL-8 level in 5 and 100 μg/ml T-614 treated groups were significantly higher(<i>P</i>&lt;0.05); in the presence of TNF-α, IL-8 level in 5, 50, and 100 μg/ml T-614 treated groups were significantly higher (<i>P</i>&lt;0.001, <i>P</i>&lt;0.001, <i>P</i>&lt;0.01, respectively); (Figure 3). There was a negative correlation between supernatant IL-8 level and the concentration of T-614 in groups stimulated with TNF-α (<i>r</i> = -0.670, <i>P</i> =0.000). TNF-α increased IL-8 level in the control group and various concentrations of T-614 treated groups (all <i>P</i>&lt;0.001). TNF-α, tumor necrosis factor-α; HAAF, human aortic adventitial fibroblasts. Data are shown as mean ± SD of 3 independent experiments, each in triplicate. <sup>***</sup><i>P</i> &lt; 0.001, <sup>**</sup><i>P</i> &lt; 0.01 vs. control group(0μg/ml T-614) within each group alone. <h3>Conclusion</h3> T-614 can inhibit the proliferation of HAAF and promote IL-8 production; therefore, it may provide a new immunotherapeutic intervention for TA. <h3>References</h3> [1] Maiellaro, K. and W.R. Taylor, The role of the adventitia in vascular inflammation. Cardiovasc Res, 2007. 75(4): p. 640-8. [2] He, Y., et al., SIRT6 inhibits TNF-alpha-induced inflammation of vascular adventitial fibroblasts through ROS and Akt signaling pathway. Exp Cell Res, 2017. 357(1): p. 88-97. [3] Wei, Y., et al., Inhibitory Effect of a Novel Antirheumatic Drug T-614 on the IL-6-Induced RANKL/OPG, IL-17, and MMP-3 Expression in Synovial Fibroblasts from Rheumatoid Arthritis Patients. Biomed Res Int, 2015. 2015: p. 214683. <h3>Acknowledgement</h3> Funding: This project was supported by grants from China International Medical Foundation(Z-2014-06-2-1636).The sponsors had no role in the study design, data collection and analysis, decision to publish, or preparation. <h3>Disclosure of Interests</h3> None declared