Fig. 1
PBMCs’ mitochondrial mass, metabolic activity, mortality, and mtDNA quantification after UVR exposure. a, b Mitochondria mass (n = 8, 8 PBMC donors) determined by the mean fluorescence intensity values (MFI) of mitochondria labelled with MitoTracker® Green. a 1 h culture after exposure and 30’of MitoTracker® Green incubation. b 18 h culture and 30’of MitoTracker® Green incubation. Analysis, the sample/control-average transformation was used, Anderson-Darling normality test was applied. Un-paired, ANOVA test and Student’s t-test are shown in the figure with an alpha-value of 0.05 (*p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001) to observe statistically significant differences. c, d Metabolic activity measured by MTT (n = 5, 5 PBMC donors). Mean absorbance values (MAV) were measured by spectrophotometry of PBMCs treated with MTT after UVR exposure. c After 2 h incubation with MTT. d After 18 h in culture and 2 h incubation with MTT. Analysis: the sample/control-average transformation was used, Anderson-Darling normality test was applied. Un-paired, ANOVA test and Student’s t-test are shown in the figure with an alpha-value of 0.05 (*p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001) to observe statistically significant differences. e, f Determination of the effects on the mtDNA sequence of PBMCs after the exposure to UVR by qPCR (n = 8, 8 PBMC donors). The qPCR 2-ΔCT fold method was used. Primers: HB2M as the housekeeping gene sequence (Human B2M Beta-2-microglobulin, NCBI AH002619.1.), and HMito (designed for the mitochondrial genome, between positions 241 and 390, NCBI NC_012920.1) from Ajaz et al.(2015) [18] e 1 h culture after exposure. f After 18 h culture. Analysis: Un-paired, ANOVA test and Student’s t-test are shown in the figure with an alpha-value of 0.05 (*p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001) to observe statistically significant differences. g, h Mortality of PBMCs induced by UVR (n = 7, 7 PBMC donors). The percentage of dead cells was estimated by counting those positive for Trypan Blue staining and then dividing them by the total; non-labelled viable cells were considered as well. g 1 h culture after exposure. h After 18 h culture. Statistical analysis: Un-paired, ANOVA test and Student’s t-test are shown in the figure with an alpha-value of 0.05 (*p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001) to observe statistically significant differences