Decreased Collagen Xii Expression and Increased Reactive Oxygen Species Production in Levofloxacin-Treated Tendon

<i>Background:</i> Levofloxacin (LVFX) is widely used for many respiratory, urinary, and oral infections. Although rare, tendinopathy and tendon rupture have been reported in patients treated with LVFX as adverse effect. However, the exact mechanism is not fully elucidated. In this study, we investigated the effects of LVFX on tendon cells and tendon tissue. <i>Method:</i> Murine tendon cell line TT-D6 cells were treated with LVFX. Total RNA was extracted from the treated cells and quantitative reverse-transcription polymerase chain reaction (RT-PCR). LVFX-treated TT-D6 cells were subjected to cell proliferation assays and reactive oxygen species production assays. In addition, LVFX was administered to rats, and total RNA was extracted from tendon tissue and quantitatively analyzed for mRNA expression using quantitative RT-PCR. <i>Results:</i> Proliferative capacity in TT-D6 cells treated with various concentrations of LVFX showed no significant differences in any of the group comparisons. Quantitative RT-PCR analysis in TT-D6 cells showed that collagen 12a1 (COL12A1) expression was significantly decreased in the LVFX-treated group compared with the control group. The expression of matrix metalloproteinase-2 and tissue inhibitor of metalloproteinase-2 was significantly increased in the LVFX group. On the other hand, there were no significant differences in mRNA expression of decorin, matrix metalloproteinase-9, and Collagen1a1. ROS production was significantly upregulated in LVFX-treated rats, and COL12A1 expression was significantly decreased in LVFX-treated rats compared with controls in tendons collected from LVFX-treated rat models. <i>Conclusions: </i>Taken together, COL12A1 reduction may be involved in tendon injury and tendon rupture in LVFX administration, suggesting that increased ROS production may be involved.