Involvement of mitochondrial signalling pathway in HGFs/S. mitiscoculture response to TEGDMA treatment

Abstract

Although triethylene glycol dimethacrylate (TEGDMA), a resin monomer widely used in dental practice, has been shown to have cytotoxic effects on eukaryotic cells, little is known about how the oral environment influences the cytotoxicity of this biomaterial. The aim of this study was to evaluate eukaryotic cell reaction to TEGDMA in terms of the production of reactive oxygen species (ROS), the expression of Bax, the disturbance of mitochondrial membrane potential (MMP), and the occurrence of apoptosis in an in vitro coculture model of human gingival fibroblasts (HGFs) and Streptococcus mitis strain in presence of saliva. We found that S. mitis and saliva reduced the production of ROS (from 2.2 to 1.8 fold), the occurrence of apoptosis (from 11.3 to 4.7%), and the decrease of MMP (from 0.75 to 0.9 fold) induced by TEGDMA treatment. Addition of N-acetylcysteine, a well known antioxidant, improved cell viability in all experimental conditions. The results obtained in this study suggest that the presence of S. mitis and saliva in the periodontal environment could protect cells against TEGDMA toxicity. These results, shedding more light on the biological and molecular events that occur in conjuction with TEGDMA treatment in vitro in a coculture model that mimics the environment of the oral cavity, confirm the key role played by oral bacteria and saliva in preventing toxic events that can occur in vivo in HGFs.

A dual role for β1 integrin in an in vitro Streptococcus mitis/human gingival fibroblasts co‐culture model in response to TEGDMA

“…Gallorini et al . () reported a parallel trend for ROS‐COX‐2 levels leading to the hypothesis of a ROS‐mediated pathway involvement in COX‐2 activation .…”

“…It has already been demonstrated that reactive oxygen species (ROS) play a role in COX-2 activation (Li et al 2013) in different experimental models. Gallorini et al (2013) reported a parallel trend for ROS-COX-2 levels leading to the hypothesis of a ROS-mediated pathway involvement in COX-2 activation.…”

Cytotoxicity and apoptosis induction by e-cigarette fluids in human gingival fibroblasts

“…Surprisingly, also, the nicotine-free fluids induced an increased ROS production after 24 h, indicating a role for the fluid itself in triggering the oxidative stress in HGFs. Basing on Bax recruitment and activation, involved in triggering the oxidative stress [31], we studied Bax expression, which is higher after 24 h both in nicotine-containing and in nicotine-free fluids. The nicotine seems to exert a time-dependent effect, while the nicotinefree fluid's toxicity may be milder because after 48 h, nicotine-free fluid-mediated Bax expression is similar to the control.…”

Adhesion of human gingival fibroblasts/Streptococcus mitis co-culture on the nanocomposite system Chitlac-nAg

“…Human gingival fibroblasts (HGFs) were obtained at the Dental Clinic of the Department of Medical, Oral and Biotechnological Sciences of the University G. d’Annunzio. The tissue fragments were treated as previously described [ 25 ]. Signed informed consent was obtained from the donors.…”

“…Pooled unstimulated saliva was obtained from laboratory healthy staff (after no drinking or eating for two hours) by spitting method in polypropylene tube. The saliva was treated as previously described [ 25 ].…”