Effect of 1800 MHz radiofrequency field exposure on cytokine and signal transduction protein expression in differentiated THP-1 cells.

PURPOSE: To evaluate the effects of 1800 MHz continuous wave (CW) and global system for mobile communications (GSM) modulated radiofrequency electromagnetic field (RFEMF) exposures on signal transduction (ST) protein and cytokine expression in differentiated human-derived monocytic THP-1 cells. MATERIALS AND METHODS: THP-1 cells were differentiated into adherent macrophage-like cells using phorbol 12-myristate 13-acetate (PMA). Following differentiation, cells were exposed to 1800 MHz CW or GSM modulated RFEMF for 0.5, 4, or 24 h at a specific absorption rate (SAR) of 0 (sham) or 2.0 W/kg. Concurrent positive controls (lipopolysaccharide for cytokines; anisomycin for ST proteins) and negative controls were included in each experiment. The expression levels of cytokines (GM-CSF, IFN-γ, IL-1ß, IL-6, IL-10, TNF-α) from culture media and phosphorylated and total ST proteins (CREB, JNK, NF-κB, p38, ERK1/2, Akt, p70S6k, STAT3, STAT5) from cell lysates were assessed using Milliplex magnetic bead array panels. RESULTS: No consistent effect of RFEMF exposure was observed in differentiated THP-1 cells. A statistically significant effect of overall exposure condition was observed for IL-6 with GSM modulation (P = 0.042), but no difference between RFEMF and sham for any exposure condition remained following adjustment for multiple comparisons (P ≥ 0.128). No statistically significant effect of exposure condition was detected for any other cytokine evaluated with either of the RFEMF modulations (P ≥ 0.078). There were no statistically significant changes in expression levels for any of the ST proteins under any studied exposure condition (P ≥ 0.320). CONCLUSIONS: In this study, no evidence of changes were observed in differentiated human derived THP-1 cells following exposure of up to 24 h to 1800 MHz RFEMF at SARs of 0 and 2.0 W/kg on the expression of ST proteins or cytokines.

Transcriptome analysis in mouse skin after exposure to ultraviolet radiation from a canopy sunbed.

Exposure to ultraviolet radiation (UV-R), from both natural and artificial tanning, heightens the risk of skin cancer by inducing molecular changes in cells and tissues. Despite established transcriptional alterations at a molecular level due to UV-R exposure, uncertainties persist regarding UV radiation characterization and subsequent genomic changes. Our study aimed to mechanistically explore dose- and time-dependent gene expression changes, that may drive short-term (e.g., sunburn) and long-term actinic (e.g., skin cancer) consequences. Using C57BL/6N mouse skin, we analyzed transcriptomic expression following exposure to five erythemally weighted UV-R doses (0, 5, 10, 20, and 40 mJ/cm2) emitted by a UV-R tanning device. At 96 h post-exposure, 5 mJ/cm2 induced 116 statistically significant differentially expressed genes (DEGs) associated with structural changes from UV-R damage. The highest number of significant gene expression changes occurred at 6 and 48 h post-exposure in the 20 and 40 mJ/cm2 dose groups. Notably, at 40 mJ/cm2, 13 DEGs related to skin barrier homeostasis were consistently perturbed across all timepoints. UV-R exposure activated pathways involving oxidative stress, P53 signaling, inflammation, biotransformation, skin barrier maintenance, and innate immunity. This in vivo study's transcriptional data offers mechanistic insights into both short-term and potential non-threshold-dependent long-term health effects of UV-R tanning.

Novel identification of matrix proteins involved in calcitic biomineralization.

Calcitic biomineralization is essential for otoconia formation in vertebrates. This process is characterized by protein-crystal interactions that modulate crystal growth on an extracellular matrix. An excellent model for the study of calcitic biomineralization is the avian eggshell, the fastest known biomineralization process. The objective of this study is to identify and characterize matrix proteins associated with the eggshell mammillary cones, which are hypothesized to regulate the earliest stage of eggshell calcification. Mammillary cones were isolated from 2 models, fertilized and unfertilized, and the released proteins were identified by RP-nanoLC and ES-MS/MS proteomics. Proteomics analysis identified 49 proteins associated with the eggshell membrane fibers and, importantly, 18 mammillary cone-specific proteins with an additional 18 proteins identified as enriched in the mammillary cones. Among the most promising candidates for modulating protein-crystal interactions were extracellular matrix proteins, including ABI family member 3 (NESH) binding protein (ABI3BP), tiarin-like, hyaluronan and proteoglycan link protein 3 (HAPLN3), collagen alpha-1(X), collagen alpha-1(II) and fibronectin, in addition to the calcium binding proteins calumenin, EGF-like repeats and discoidin 1-like domains 3 (EDIL3), nucleobindin-2 and SPARC. In conclusion, we identified several cone-resident proteins that are candidates to regulate initiation of eggshell calcification. Further study of these proteins will determine their roles in modulating calcitic biomineralization and lead to insight into the process of otoconia formation/regeneration. BIOLOGICAL SIGNIFICANCE: Biomineralization is essential for the development of hard tissues in vertebrates, which includes both calcium phosphate and calcium carbonate structures. Calcitic mineralization by calcium carbonate is an important process in the formation of otoconia, which are gravity receptor organs located in the inner ear and are responsible for balance and for sensing linear acceleration. Deficiencies in the regulation of their biomineralization can lead to otoconia degeneration and eventually benign paroxysmal position vertigo (BPPV), which is the main cause of vertigo in humans. Eggshell formation in chicken is one of the fastest known biomineralization processes and is an excellent model for the study of calcitic biomineralization. Cross-analysis of proteomic data from two mineralized models, fertilized and unfertilized chicken eggshells, identified proteins associated with the mammillary cones that are the sites of initiation of eggshell formation. We hypothesize that these proteins regulate the earliest stages of eggshell calcification. The human homologs of these proteins are therefore potential candidates to play a role in otoconia biomineralization.