The Effect of Indocyanine Green Antimicrobial Photothermal/Photodynamic Therapy on the Expression of BCL-2 and BAX Messenger RNA Levels in Human Gingival Fibroblast Cells

Abstract

Background: Antimicrobial photothermal/photodynamic therapy (PTT/PDT) with indocyanine green (ICG) is an adjuvant therapeutic approach in the treatment of periodontitis. To explore whether PTT/PDT with ICG causes cell death by apoptosis in human gingival fibroblast (HGF) cells, BAX and BCL-2 genes expression as key events for apoptosis were evaluated in this study. Materials and methods: HGF cells were treated with: 1) different concentrations (500–2000 µg/mL) of ICG alone, 2) Diode laser irradiation alone with a fluency of 39.06 J/cm2; 3) PTT/PDT combined different concentrations (500–2000 µg/mL) of ICG with an 808 nm diode laser with a fluency of 39.06 J/cm2, and 4) controls (untreated cells). After that, BAX and BCL-2 messenger RNA levels were evaluated by real-time quantitative reverse transcription PCR. Results: PTT/PDT with 500 µg/mL of ICG caused significant increases in the expression of the BAX gene, with an 8.5-fold increase, which was approximately 7- and 8.5-fold higher than PTT/PDT with ICG for 1500 and 2000 µg/mL of ICG, respectively, indicating induction of apoptosis in HGF cells. ICG (in different test concentrations), diode laser, and PTT/PDT with ICG (1500 and 2000 µg/mL of ICG) treatment displayed insignificant increases in expression levels of BAX (all p>0.05). Our experiments showed an insignificant increase (1.1–1.6-fold) in the expression of BCL-2 after ICG, diode laser, and PTT/PDT with ICG treatment (all p>0.05). Conclusions: This study suggests that various concentration of ICG can be the diverse expression of BAX responses to PTT/PDT on HGF cells.

Photodynamic therapy in periodontitis: A narrative review

“…Gharesi et al 50 found that exposing to a diode laser for 60 s with ICG (1000 μg/mL) induced the expression of BAX, the marker of apoptosis on HGF. Similarly, Pourhajibagher et al 51 also found that antimicrobial photothermal/PDT with ICG (500 μg/mL) increases the expression of BAX.…”

Injectable hydrogel nanoarchitectonics with near-infrared controlled drug delivery for in situ photothermal/endocrine synergistic endometriosis therapy

“…Dong et al considered that PTT can convert light into heat under light irradiation, or generate ROS, to promote necrosis or apoptosis of rheumatoid arthritis inflammatory cells [ 47 ]. Pourhajibaghe et al demonstrated that apoptosis caused by PTT led to human gingival fibroblast cells death by verifying increased expression of apoptosis-related BAX messenger RNA levels [ 48 ]. Like above non-tumor cells, endometriosis cells could send out signals after receiving mild photothermal stimulation for a short period of time, causing a series of events such as intracellular heat stress, mitochondrial damage, oxidative stress, DNA damage and caspase activation, thereby triggering cell apoptosis in response to environmental changes.…”