Funding informationSelf-funded project Cyclosporine induces overgrowth of human gingiva. Previously we have shown (i) cyclosporine-inducing ER stress in human gingival fibroblasts (HGF), (ii) increased matrix protein expression, and (iii) interference with mitochondrial pro-and anti-apoptotic factors.This study was undertaken to assess the effects of melatonin (an antioxidant), 4PBA (an ER stress inhibitor), and simvastatin on the expression of ER Stress markers as well as on matrix and mitochondrial markers. HGF incubated with cyclosporine, or without melatonin/4PBA/ statin. After 24 hr of incubation, mRNA expression of ER stress markers (GRP78, CHOP, XBP1, and XBPs) and matrix protein markers (like α-SMA, VEGF, TGF-β, CTGF), and mitochondrial apoptosis markers estimated and compared with housekeeping gene GAPDH.Compared to the control cyclosporine significantly augmented ER Stress and matrix proteins, which decreased significantly with the use of melatonin, 4PBA, and simvastatin. The mitochondrial proapoptotic molecule cyclophilin D, as well as Bcl2 expression also decreased after PBA treatment, paralleling an increase in cytochrome c expression. The effect of 4PBA was much more pronounced than the influence of other two. In conclusion, 4PBA could be a viable therapeutic option for drug-induced gingival overgrowth.
K E Y W O R D Scyclosporine, ER stress, gingiva, 4PBA
| INTRODUCTIONCyclosporine has increased the survival rate of patients who have undergone transplantations, but the same cannot be said about improving the quality of life of those patients. Through its calcineurin blocking property, cyclosporine induces significant immunosuppression property. However, akin to other immune suppressants cyclosporine also induces toxicity and one common side effect of cyclosporine is gingival overgrowth (cyclosporine induced gingival overgrowth (Boltchi, Rees, & Iacopino, 1999) which compromises aesthetics and masticatory function. The overgrowth according to some authors is vascular (Kataoka, Kido, Shinohara, & Nagata, 2005).Though many researchers have observed fibrosis markers like α smooth muscle actin (αSMA), (Chen, Yang, Yu, Yu, & Gong, 2016) transforming growth factor β (TGFβ) and connective tissue growth factor (CTGF) (Yang, Deng, Hsieh, Wu, & Kuo, 2015), etc. At the cellular level, cyclosporine is notoriously anti-apoptotic in gingival fibroblast (Jung, Jeong, Jeong, Chung, & Kim, 2008). Many theories have proposed for the overgrowth and the most acceptable by many researchers is the concept of fibroblast heterogeneity (Tipton, Stricklin, & Dabbous, 1991). Apart from cyclosporine, phenytoin, and nifedipine also induce gingival overgrowth, but histopathological they are quite a fibrosis.In addition to gingiva, cyclosporine induces many systemic side effects, the most common being renal fibrosis. One of the significant observation in cyclosporine triggered renal fibrosis is the generation of oxidative stress (O'Connell, Tuite, Slattery, Ryan, & McMorrow, 2012), and the drug demonstrated a tendency to indu...