Biological roles of KGF, CTGF and TGF-β in cyclosporine-A- and phenytoin- induced gingival overgrowth: A comparative experimental animal study

Improvement of drug-induced gingival overgrowth and cerebrovascular related dementia after dental treatments

Drug-induced gingival overgrowth can occur as a side effect of specific drugs and lead to poor oral function. Appropriate dental management of the overgrowth may improve oral function and improve cognitive deficits after cerebrovascular accidents.

Cyclosporine-Induced Gingival Hyperplasia in a Patient With Lichen Planopilaris: Misfortunes Never Come Singly!

Cyclosporine A constitutes an immunosuppressive medication administered against various autoimmune and autoinflammatory disorders as well as against graft versus host disease. Its most well-known oral adverse effect is gingival hyperplasia. The aim of this study is to report a persistent case of a patient with lichen planopilaris with alopecia treated with cyclosporine leading to the manifestation of gingival hypertrophy. A female patient aged 38 years old was referred to the Department of Oral Medicine/Pathology, Dental School, Aristotle University of Thessaloniki, Greece complaining about gum bleeding, halitosis, and a persistent gingival enlargement, which appeared two months ago. According to her medical history, lichen planopilaris was diagnosed six months ago and was initially treated for 40 days with methylprednisolone 16 mg twice per day without improvement, and was replaced by cyclosporine A 200 mg per day. The clinical oral examination revealed gingival enlargement at areas #34-43, 22-23, and 25-27 without any lesion of lichen planus. The level of oral hygiene was satisfactory, with a limited amount of tartar and plaque. Bleeding on probing was also noticed, and pseudopockets of 5 mm were observed. The serum levels of cyclosporine were 473,60 μg/L, with a normal range, regarding repercussions in the oral cavity, up to 200 μg/L. A decrease of cyclosporine dosage to 150 mg was performed. After 15 days, the clinical appearance significantly improved, and a biopsy was done. The microscopic findings showed mild ulceration and inflammatory infiltrates, together with the abundant presence of collagen stroma, without any sign of malignancy. According to the literature, the high dosage of cyclosporine, its relevant high serum levels, and the presence of plaque were responsible for the manifestation of gingival hypertrophy.

Cyclosporine-induced gingival overgrowth-Review

Drug-induced gingival overgrowth (DIGO) is an undesirable effect resulting from the therapy of one of the three groups of drugs: phenytoin, calcium channel blockers, and cyclosporine A (CsA). It is caused by a fibrous overgrowth leading to gingivitis, periodontitis, and even tooth loss. Possible consequences include tooth decay worsening, pain and difficulty in eating, bleeding gums, and bad breath. The pathomechanism of the hypertrophy is unknown, but there is a correlation between insufficient oral hygiene and the severity of this phenomenon. The gender and age predilection of gingival hyperplasia as a result of CsA therapy is also noticeable. It is most common in children and adolescents of the male sex. The beneficial effect of the removal of tartar and local irritants in reducing the above symptoms has been demonstrated. One of the treatments for DIGO is conventional gingivectomy. The paper is a review article about cyclosporine-induced gingival hyperplasia.

The role of nuclear receptor 4A1 (NR4A1) in drug-induced gingival overgrowth

Drug-induced gingival overgrowth (DIGO) is a side effect of cyclosporine A (CsA), nifedipine (NIF), and phenytoin (PHT). Nuclear receptor 4A1 (NR4A1) plays a role in fibrosis in multiple organs. However, the relationship between NR4A1 and DIGO remains unclear. We herein investigated the involvement of NR4A1 in DIGO. In the DIGO mouse model, CsA inhibited the up-regulation of Nr4a1 expression induced by periodontal disease (PD) in gingival tissue, but not that of Col1a1 and Pai1. We detected gingival overgrowth (GO) in Nr4a1 knock out (KO) mice with PD. A NR4A1 agonist inhibited the development of GO in DIGO model mice. TGF-β increased Col1a1 and Pai1 expression levels in KO mouse gingival fibroblasts (mGF) than in wild-type mice, while the overexpression of NR4A1 in KO mGF suppressed the levels. NR4A1 expression levels in gingival tissue were significantly lower in DIGO patients than in PD patients. We also investigated the relationship between nuclear factor of activated T cells (NFAT) and NR4A1. NFATc3 siRNA suppressed the TGF-β-induced up-regulation of NR4A1 mRNA expression in human gingival fibroblasts (hGF). CsA suppressed the TGF-β-induced translocation of NFATc3 into the nuclei of hGF. Furthermore, NIF and PHT also decreased NR4A1 mRNA expression levels and suppressed the translocation of NFATc3 in hGF. We confirmed that CsA, NIF, and PHT reduced cytosolic calcium levels increased by TGF-β, while CaCl₂ enhanced the TGF-β-up-regulated NR4A1 expression. We propose that the suppression of the calcium-NFATc3-NR4A1 cascade by these three drugs plays a role in the development of DIGO.

Drug-Induced Gingival Overgrowth: A Pilot Study on the Effect of Diphenylhydantoin and Gabapentin on Human Gingival Fibroblasts

INTRODUCTION

The administration of several classes of drugs can lead to the onset of gingival overgrowth: anticonvulsants, immunosuppressants, and calcium channel blockers. Among the anticonvulsants, the main drug associated with gingival overgrowth is diphenylhydantoin.

MATERIALS AND METHODS

In this study, we compared the effects of diphenylhydantoin and gabapentin on 57 genes belonging to the "Extracellular Matrix and Adhesion Molecule" pathway, present in human fibroblasts of healthy volunteers.

RESULTS

Both molecules induce the same gene expression profile in fibroblasts as well as a significant upregulation of genes involved in extracellular matrix deposition like COL4A1, ITGA7, and LAMB3. The two treatments also induced a significant downregulation of genes involved in the expression of extracellular matrix metalloproteases like MMP11, MMP15, MMP16, MMP24, and transmembrane receptor ITGB4.

CONCLUSIONS

Data recorded in our study confirmed the hypothesis of a direct action of these drugs at the periodontium level, inducing an increase in matrix production, a reduction in its degradation, and consequently resulting in gingival hyperplasia.

Human gingiva transcriptome during wound healing

OBJECTIVES

To investigate the gene expression profile of human gingiva following surgical wounding.

METHODS

Ten volunteers had one side of the palate wounded. Five days later, biopsies were harvested from both wounded (healing gingiva) and contra-lateral site (normal gingiva). Tissue samples were processed for gene expression (RNA-Seq, real-time PCR) and immunohistochemistry. Gene set enrichment/pathway analysis was also performed.

RESULTS

Seven hundred genes were significantly differentially expressed in healing gingiva. Among genes with >twofold change (FC) in expression, 399 genes were up-regulated and 88 down-regulated, several not previously reported expressed in gingiva. Most increased in expression (≥30-FC) were MMP1, CCL18, SPP1, MUC21, CTHRC1, MMP10, and SERPINE1; most decreased (≥7-FC) were COCH, SIAH3, MT4, IGFL3, KY, and SYT16. Real-time PCR confirmed significantly changed mRNA levels for selective genes tested. Gene set enrichment analysis revealed several significantly enriched biological pathways. Immunohistochemistry confirmed protein expression of MUC21, CTHRC1, CTGF, and SYT16 in normal and healing gingiva.

CONCLUSIONS

This first comprehensive analysis of the human gingival transcriptome during surgical wound healing offers novel insights into the participating molecular and biological mechanisms. The present results could serve as basis for future investigations into gingival wound healing following surgical, traumatic, or other type of injury.