Toxic Effects of Urethane Dimethacrylate on Macrophages Through Caspase Activation, Mitochondrial Dysfunction, and Reactive Oxygen Species Generation

Abstract

Urethane dimethacrylate (UDMA) is a dimethacrylate-based resin monomer that can react with other related monomers and inorganic particles, causing hydrophobic polymerization through cross-linking upon light activation. UDMA polymers are commonly used for the reconstruction and reinforcement of teeth and bones. UDMA can become unbound and be released from light-cured polymer resins. Thus far, no evidence exists on the toxic effects of UDMA and its related working mechanisms for macrophages. Therefore, in the present study, we investigated the cytotoxicity, mode of cell death, DNA damage, caspase activities, mitochondrial dysfunction, and reactive oxygen species (ROS) generation in RAW264.7 macrophages treated with UDMA using the lactate dehydrogenase (LDH) assay kit, Annexin V-FITC and PI assays, micronucleus formation and comet assay, caspase fluorometric assay, JC-1 assay, and 2ʹ,7ʹ-dichlorofluorescin diacetate (DCFH-DA) assay, respectively. Our results show that UDMA induced cytotoxicity; apoptosis and necrosis; genotoxicity, which is also called DNA damage; increased caspase-3, -8, and -9 activities; mitochondrial dysfunction; and intracellular ROS generation in a concentration-dependent manner in RAW264.7 macrophages. Thus, based on the observed inhibited concentration parallel trends, we concluded that UDMA induces toxic effects in macrophages. Furthermore, UDMA-induced intracellular ROS generation, cytotoxicity, and DNA damage were reduced by N-acetyl-L-cysteine.

1‐Nitropyrene Induced Reactive Oxygen Species–Mediated Apoptosis in Macrophages through AIF Nuclear Translocation and AMPK/Nrf‐2/HO‐1 Pathway Activation

“…Mitochondrial dysfunction is a critical factor in macrophage apoptosis [20,35]. During mitochondrial dysfunction, the dissipation of mitochondrial membrane potential and loss of mitochondrial membrane integrity were observed in macrophages after exposure to apoptotic stimuli [20,35].…”

“…Mitochondrial dysfunction is a critical factor in macrophage apoptosis [20,35]. During mitochondrial dysfunction, the dissipation of mitochondrial membrane potential and loss of mitochondrial membrane integrity were observed in macrophages after exposure to apoptotic stimuli [20,35]. AIF, a mammalian-soluble protein containing flavin adenine dinucleotide, is a nicotinamide adenine dinucleotidedependent oxidoreductase located in the mitochondrial intermembrane space [36].…”

“…All cells were grown as monolayer cultures at 37°C in 5% CO 2 using DMEM supplemented with 1% penicillin, streptomycin, fungizone, and 10% FBS. Cell passaging was conducted using 0.05% trypsin with 0.53 mM EDTA [20]. After seeding, the cells were incubated with 1-NP at the concentrations of 0, 3, 10, 30, and 50 μM for 6, 12, 24, and 48 h for cell viability assay.…”

“…Mitochondrial disruption plays a key role in macrophage apoptosis [14,17]. Several molecular mechanisms participate in mitochondrial disruption which include the expression of the Bcl-2 family; translocations of apoptosis-inducing factor (AIF) and cytochrome c; and depletion of antioxidative enzymes (AOEs), such as glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD), and heme oxygenase-1 (HO-1) [14,[18][19][20]. Recently, we have reported that cytotoxicity and genotoxicity were induced by 1-NP by poly (ADP-ribose) polymerase-1 (PARP-1) cleavage via caspase-3 and -9 activation through cytochrome c release from mitochondria and its upstream p53-dependent pathway in macrophages [21].…”

Biodegradation of Dental Resin-Based Composite—A Potential Factor Affecting the Bonding Effect: A Narrative Review

“…TEGDMA and UDMA, monomers released from the resin, also have specific cytotoxicity. One effect of TEGDMA and UDMA on cells is that they can reduce the level of glutathione (GSH), a natural free radical scavenger that protects cells from ROS damage, and thus accelerate cell apoptosis [ 91 , 92 ]. Similar to Bis-GMA, they can also activate Caspase-3, 8 and 9, causing apoptosis in dental pulp cells [ 93 , 94 ].…”