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Published on: April 23, 2019
Antimicrobial photodynamic therapy reduces gene expression of Candida albicans in biofilms
Cláudia Carolina Jordão1, Tábata Viana de Sousa1, Marlise Inêz Klein1
1Department of Dental Materials and Prosthodontics, School of Dentistry at Araraquara, Univ Estadual Paulista - UNESP, Rua Humaitá, 1680, 14801-903, Araraquara, SP, Brazil.
Abstract:
The present study evaluated whether the oxidative stress caused by antimicrobial photodynamic therapy (aPDT) affects the expression of C. albicans genes related to adhesion and biofilm formation (ALS1 and HPW1) and oxidative stress response (CAP1, CAT1, and SOD1). The aPDT was mediated by two photosensitizing agents (PSs) Photodithazine® (PDZ at 100 and 200 mg/L) or Curcumin (CUR at 40 and 80 μM) and LED (37.5 J/cm2 or 50 J/cm2). The quantification of the expression was performed by Reverse Transcription-Quantitative Polymerase Chain Reaction (RT-qPCR) using specific primers for the target genes. The data were analyzed by Analysis of Variance (α = 0.05), followed by Tukey's post-test. It was observed reduction in the expression of ALS1, HWP1, CAP1, CAT1, and SOD1 when aPDT was performed using 200 mg/L PDZ and 80 μM CUR associated to LED (37.7 and 50 J/cm2, respectively) and using 100 mg/L PDZ and 40 μM CUR with LED of 50 J/cm2 (versus control). Also, the expression of CAP1 and SOD1 genes was reduced after aPDT using 100 mg/L PDZ and LED of 37.5 J/cm2. There was a significant reduction in the expression of genes HWP1, CAP1, and SOD1 after aPDT using 40 μM CUR and 37.5 J/cm2 (versus the control group). The application of LED only at 37.5 and 50 J/cm2 promoted down-regulation of ALS1, CAP1, CAT1, and SOD1 genes (versus the control group). Therefore, aPDT mediated by LED -associated PSs PDZ and CUR promoted a reduction in the expression of the five C. albicans genes evaluated.
Insights
Antimicrobial photodynamic therapy (aPDT) using Photodithazine® (PDZ) or Curcumin (CUR) reduced the expression of key Candida albicans genes. This aPDT approach effectively down-regulates genes involved in adhesion, biofilm formation, and oxidative stress response.
Area of Science:
- Microbiology
- Biochemistry
- Photomedicine
Background:
- Candida albicans is an opportunistic fungal pathogen known for its ability to form biofilms and cause persistent infections.
- Antimicrobial photodynamic therapy (aPDT) is a promising alternative to conventional antimicrobial treatments, utilizing photosensitizers and light to generate reactive oxygen species.
- Understanding the molecular mechanisms of aPDT, particularly its impact on fungal gene expression, is crucial for optimizing its therapeutic efficacy.
Purpose of the Study:
- To investigate the effect of aPDT-induced oxidative stress on the expression of specific Candida albicans genes.
- To evaluate the influence of different photosensitizing agents (Photodithazine® and Curcumin) and light doses on gene expression.
- To assess changes in genes related to adhesion (ALS1, HWP1) and oxidative stress response (CAP1, CAT1, SOD1).
Main Methods:
- aPDT was administered using Photodithazine® (PDZ) or Curcumin (CUR) at varying concentrations combined with LED light.
- Gene expression levels were quantified using Reverse Transcription-Quantitative Polymerase Chain Reaction (RT-qPCR).
- Statistical analysis was performed using Analysis of Variance (ANOVA) and Tukey's post-test.
Main Results:
- aPDT with PDZ (200 mg/L) or CUR (80 μM) significantly reduced the expression of ALS1, HWP1, CAP1, CAT1, and SOD1 genes.
- Lower concentrations of PDZ (100 mg/L) and CUR (40 μM) with specific light doses also led to down-regulation of several target genes.
- LED light alone, without photosensitizers, also induced a reduction in the expression of ALS1, CAP1, CAT1, and SOD1 genes.
Conclusions:
- aPDT mediated by LED-activated PDZ and CUR effectively reduces the expression of key virulence-associated genes in Candida albicans.
- The study demonstrates that aPDT can modulate fungal gene expression, offering a potential strategy to combat C. albicans infections.
- These findings support the potential of aPDT as an adjunctive therapy for managing Candida infections by targeting essential fungal pathways.
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