5-aminolevulinic acid photodynamic therapy protects against UVB-induced skin photoaging: A DNA-repairing mechanism involving the BER signalling pathway.

Low-dose 5-aminolevulinic acid photodynamic therapy (ALA-PDT) has been used to cope with skin photoaging, and is thought to involve DNA damage repair responses. However, it is still unknown how low-dose ALA-PDT regulates DNA damage repair to curb skin photoaging. We established a photoaging model using human dermal fibroblasts (HDFs) and rat skin. RNA-sequencing (RNA-seq) analysis was conducted to identify differentially expressed genes (DEGs) in HDFs before and after low-dose ALA-PDT treatment, followed by bioinformatics analysis. Senescence-associated ß-galactosidase (SA-ß-gal) staining was employed to assess skin aging-related manifestations and Western blotting to evaluate the expression of associated proteins. A comet assay was used to detect cellular DNA damage, while immunofluorescence to examine the expression of 8-hydroxy-2'-deoxyguanosine (8-oxo-dG) in cells and skin tissues. In both in vivo and in vitro models, low-dose ALA-PDT alleviated the manifestations of ultraviolet B (UVB)-induced skin photoaging. Low-dose ALA-PDT significantly reduced DNA damage in photoaged HDFs. Furthermore, low-dose ALA-PDT accelerated the clearance of the photoproduct 8-oxo-dG in photoaged HDFs and superficial dermis of photoaged rat skin. RNA-seq analysis suggested that low-dose ALA-PDT upregulated the expression of key genes in the base excision repair (BER) pathway. Further functional validation showed that inhibition on BER expression by using UPF1069 significantly suppressed SA-ß-gal activity, G2/M phase ratio, expression of aging-associated proteins P16, P21, P53, and MUTYH proteins, as well as clearance of the photoproduct 8-oxo-dG in photoaged HDFs. Low-dose ALA-PDT exerts anti-photoaging effects by activating the BER signalling pathway.

Protective autophagy enhances antistress ability through AMPK/ULK1 signaling pathway in human immortalized keratinocytes.

Keratinocytes, located in the outermost layer of human skin, are pivotal cells to resist environmental damage. Cellular autophagy plays a critical role in eliminating damaged organelles and maintaining skin cell homeostasis. Low-dose 5-Aminolevulinic acid photodynamic therapy (ALA-PDT) has been demonstrated to enhance skin's antistress ability; however, the regulatory mechanisms of autophagy in keratinocytes remain unclear. In this study, we treated immortalized human keratinocytes (HaCaT cells) with low-dose ALA-PDT (0.5 mmol/L, 3 J/cm2). Through RNA-sequencing analysis, we identified that low-dose ALA-PDT modulated autophagy-related pathways in keratinocytes and pinpointed Unc-51-like kinase 1 (ULK1) as a key gene involved. Western blot results revealed that low-dose ALA-PDT treatment upregulated the expression of autophagy-related proteins Beclin-1 and LC3-II/LC3-I ratio. Notably, low-dose ALA-PDT regulated autophagy by inducing an appropriate level of reactive oxygen species (ROS), transiently reducing mitochondrial membrane potential, and decreasing adenosine triphosphate production; all these processes functioned on the AMP-activated protein kinase (AMPK)/ULK1 pathway to activate autophagy. Finally, we simulated external environmental damage using ultraviolet B (UVB) at a dose of 60 mJ/cm2 and observed that low-dose ALA-PDT mitigated UVB-induced cell apoptosis; however, this protective effect was reversed when using the autophagy inhibitor 3-methyladenine. Overall, these findings highlight how low-dose ALA-PDT enhances antistress ability in HaCaT cells through controlling ROS generation and activating the AMPK/ULK1 pathway to arouse cellular autophagy.

Peripheral blood CD4+ T cell count predicts recurrence of condyloma acuminatum after photodynamic therapy in HIV-positive patients.

BACKGROUND: Few studies have reported postoperative relapse of condyloma acuminatum (CA) after 5-aminolevulinic acid photodynamic therapy (ALA-PDT) in human immunodeficiency virus (HIV) positive patients. METHODS: The clinical data of HIV-positive CA patients treated with ALA-PDT from October 2018 to December 2019 were analyzed retrospectively. Univariate and multivariate Cox regression was used to analyze the variables related to postoperative recurrence. Pearson correlation test was employed to analyze the correlation between CD4+ T cell count and postoperative recurrence rate. Kaplan-Meier method was used to compare the CA recurrence after ALA-PDT in low CD4 group and high CD4 group. RESULTS: A total of 38 HIV-positive patients with CA were included in the study. Among them, 26 patients experienced CA recurrence within 6 months, and the recurrence rate was 68.4%. CD4+ T cell count was 187.0 (79.0-596.0) cells/µl in relapsed patients and 406.0 (89.0-612.0) cells/µl in non-relapsed patients, showing a statistically significant difference (p = .005). Pearson correlation coefficient analysis revealed a negative correlation between CD4+ T cell count and postoperative recurrence rate (p = .005, r = -.443). Univariate regression analysis showed that CD4+ T cell count was correlated with postoperative recurrence, hazard ratio (HR) was 0.99 [95% Confidence interval (CI) = 0.99-1.0, p = .012]. Multivariate Cox regression analysis showed that with the low CD4+ T cell count as the reference, the high CD4+ T cell count was negatively correlated with postoperative recurrence (HR = 0.09, 95% CI 0.01-0.87, p = .038). CONCLUSIONS: Peripheral blood CD4+ T cell count can predict the CA recurrence rate after ALA-PDT in HIV-positive patients.

A novel nomogram based on a retrospective study of 346 patients to predict the recurrence risk of condyloma acuminatum after 5-aminolevulinic acid photodynamic therapy.

Condyloma acuminatum (CA) is a sexually transmitted disease caused by human papillomavirus (HPV) often with high recurrence rate after treatment. This study aimed to construct and evaluate a nomogram model containing three clinical parameters to predict the recurrence risk of CA after 5-aminolevulinic acid photodynamic therapy (ALA-PDT). A predictive model was established based on a training cohort of 346 CA patients treated with ALA-PDT between January 2013 and July 2018. A validation cohort of 123 CA patients was recruited from August 2018 to December 2019. The least absolute shrinkage and selection operator (LASSO) regression model was used to optimize the clinical feature selection. A nomogram predicting the recurrence of CA after ALA-PDT was constructed based on the predictors identified by LASSO regression. C-index and area under the curve (AUC) values were used to evaluate the discrimination. Calibration was evaluated with a calibration curve. The net benefit was performed via decision curve analysis (DCA). In the training cohort, 55 (15.89%) patients experienced recurrences after ALA-PDT. Predictors selected by LASSO regression were concomitant human immunodeficiency virus (HIV) infection [Hazard ratio (HR) = 4.4; 95% confidence interval (CI), 2.5-7.9; p < 0.001], skin and mucosa as affected area (HR = 1.7; 95% CI, 0.9-3.1; p = 0.109), and more than one time of CO2 laser therapy (HR = 6.3; 95% CI, 2.8-13.9; p < 0.001). The nomogram showed a good performance in predicting recurrence as the C-indexes were 0.843 (95% CI, 0.799-0.887) in the training cohort, and 0.831 (95% CI, 0.727-0.934) in the validation cohort. The AUCs of the nomogram were 0.85 in training and 0.8 in validation. DCA confirmed the nomogram was clinically useful when the intervention was determined at the non-adherence possibility threshold of 5%. This nomogram can provide individualized prediction for the recurrence risk of CA in patients treated by ALA-PDT.

Multiple-type HPV infection predicting condyloma acuminatum recurrence after aminolevulinic acid photodynamic therapy.

BACKGROUND: Aminolevulinic acid photodynamic therapy (ALA-PDT) has been widely used in the treatment of condyloma acuminatum (CA), but there is a lack of reports on clinical factors related to CA relapse after photodynamic therapy. METHODS: The clinical data of patients with CA treated with ALA-PDT from April 2018 to December 2019 were retrospectively analyzed, including HPV type, follow-up time and recurrence within 6 months after treatment. The patients were classified into single-type HPV infection and multiple-type HPV infection groups. Besides, the patients were also classified into high-risk HPV infection, low-risk HPV infection, and low + high-risk HPV infection groups. Univariate and multivariate COX regression was performed to analyze whether HPV type was related with CA relapse after photodynamic therapy. RESULTS: A total of 161 CA patients who underwent ALA-PDT were analyzed in this study. CA recurred in 20 patients within 6 months after treatment, with a recurrence rate of 12.4%. Of them, the patients with multiple-type HPV infection made up 85%. Multivariate COX regression analysis revealed that multiple-type HPV infection was associated with CA recurrence (HR:5.0; 95% CI: 1.1-21.4; P = 0.032). Of the patients with CA recurrence, 70% developed low + high-risk infections, a proportion significantly higher than that in patients without CA relapse (16.3%, P < 0.001). Using low-risk infection as a reference, low + high-risk infection was positively correlated with postoperative recurrence (HR: 6.7; 95% CI: 1.6-26.2; P = 0.006). CONCLUSION: Multiple-type HPV infection were closely associated with CA recurrence after photodynamic therapy.