Upregulation of CCL7, CCL20, CXCL2, IL-1ß, IL-6 and MMP-9 in Skin Samples of PCB Exposed Individuals-A Preliminary Study.

Polychlorinated biphenyls (PCBs) are well known immunotoxic and carcinogenic compounds. Although cutaneous symptoms are the hallmark of exposure to these compounds, exact pathophysiologic mechanisms are not well understood. We took skin biopsies from moderately high PCB exposed workers (n = 25) after an informed consent and investigated the expression of immunological markers such as CCL-7, CCL-20, CXCL2, IL-1ß and IL-6, as well as the matrix metalloproteinase MMP-9, EPGN and NRF2 by RT-qPCR, and compared expression levels with plasma PCB levels. Statistical analyses showed a significant correlation between CCL-20, CXCL2, IL-6, IL-1ß, CCL-7 and MMP-9 and PCB serum levels. EPGN and NRF2 were not correlated to PCB levels in the blood. We found a significant correlation of genes involved in autoimmune, auto-inflammatory and carcinogenesis in skin samples of PCB exposed individuals with elevated plasma PCB levels. Confirmation of these findings needs to be performed in bigger study groups and larger gen-sets, including multiple housekeeping genes. Further study needs to be performed to see whether a chronical exposure to these and similar compounds can cause higher incidence of malignancies and inflammatory disease.

Biological Effects of Hyaluronic Acid-Based Dermal Fillers and Laser Therapy on Human Skin Models.

Injection of dermal fillers is one of the most frequently performed aesthetic procedures. The aim of the present study was to investigate the biological effects of different stabilized hyaluronan (HA) and poly-l-lactic acid fillers with and without subsequent additional fractional laser co-treatment on skin morphology and gene expression. Intradermal injection resulted in a significant enhancement of epidermal thickness detected by histological analysis. Combining HA fillers with ablative fractional CO2- or Er:YAG laser irradiation enhanced this effect. Gene expression profiling revealed an upregulation of modulators of tissue remodeling (eg TIMP3, SERPIN E1) and collagens (COL11A1). On the other hand, we detected a downregulation of differentiation markers (eg FLG, LOR, KRT1) and proinflammatory cytokines (eg IL-36, IL-1β). Interestingly, HA-based fillers revealed a specific upregulation pattern of chemokines such as CXCL5 andCCL20 suggesting a secondary effect of these fillers on the immune cells of the skin, especially monocytes and macrophages. Taken together, our data show enhancing effects of dermal fillers on epidermal thickness and prove the proliferating effects of these products on epidermal cells on the molecular level. Moreover, our findings reveal synergistic effects of fractional ablative laser treatment and HA dermal filler injection suggesting a combination of both treatments. J Drugs Dermatol. 2020;19(9):897-899. doi:10.36849/JDD.2020.4856.

Bifonazole Exerts Anti-Inflammatory Effects in Human Three-Dimensional Skin Equivalents after UVB or Histamine Challenge.

BACKGROUND: In addition to its role as a broad-spectrum imidazole antifungal drug, data from animal models as well as human clinical trials also demonstrated an anti-inflammatory efficacy of bifonazole (BFZ). In the histamine wheal test and after UV radiation, BFZ showed antiphlogistic effects that were comparable to those of hydrocortisone. However, the underlying molecular mechanisms of the anti-inflam-matory properties of BFZ are poorly understood. METHODS: Performing an in vitro study we used full-thickness three-dimensional (3D) skin models containing macrophages as mediators of inflammation. We conducted two sets of experiments. In a first set we exposed our models to UVB irradiation to provoke an inflammation. A second approach used the addition of histamine into the culture medium. In both approaches, models were treated topically with a BFZ-containing ointment or a placebo ointment for 24 h, and then the effects were examined histologically as well as with microarray and quantitative real-time PCR analyses. RESULTS: Histological examination showed that the BFZ-containing ointment reconstituted UVB- and histamine-mediated disorders within the skin models. Performing gene expression profiling in models that were treated with the BFZ-containing ointment after UVB irradiation, we detected an upregu-lation of differentiation markers (fillagrin, loricrin, and keratin 1), antimicrobial peptides (DEFB103A), and members of the cytochrome P450 family (CYP1A1 and CYP1B1) as well as a downregulation of genes that are involved in immune response (CCL22, CXCL12, CCL7, IRF1, ICAM1, TLR3, and RARRES3) and matrix metalloproteinases (MMP12 and MMP7). Models that were treated with the BFZ-containing ointment after histamine application showed an upregulation of members of the cytochrome P450 family (CAP1A1, CYP1B1, and CYP24A1) and a downregulation of immune response-associated genes (CXCL6, CXCL12, CCL8, IL6, and IL32). CONCLUSION: We present the first in vitro study showing anti-inflammatory effects of BFZ in human 3D skin models. To our knowledge, this is the first time that these effects could be translated from human clinical trials into an in vitro test system, allowing a more detailed examination of molecular mechanisms that were regulated by BFZ.

Altered Gene Expression in Dioxin-Like and Non-Dioxin-Like PCB Exposed Peripheral Blood Mononuclear Cells.

Polychlorinated biphenyls (PCBs) are well known carcinogenic persistent environmental pollutants and endocrine disruptors. Our aim was to identify the possible dysregulation of genes in PCB exposed peripheral blood mononuclear cells (PBMCs) in order to give more insight into the differential pathophysiological effects of PCB congeners and mixtures, with an emphasis on immunological effects and oxidative stress. The PBMCs of a healthy volunteer (male, 56 years old) were exposed to a mixture of dioxin-like (DL)-PCBs (PCB 77, 81, 105, 114, 118, 123, 126, 156, 157, 167, 169, and 189, 250 µg/L resp.) or non-dioxin-like (NDL)-PCBs (PCB 28, 52, 101, 138, 153, 180, 250 µg/L resp.) or single PCB congener (no.28, 138, 153, 180, 250 µg/L resp.). After an incubation period of 24 h, a microarray gene expression screening was performed, and the results were compared to gene expression in control samples (PBMCs treated with the vehicle iso-octane). Treatment of PBMCs with the DL-PCB mixture resulted in the largest number of differentially regulated genes (181 upregulated genes >2-fold, 173 downregulated >2-fold). Treatment with the NDL-PCB mix resulted in 32 upregulated genes >2-fold and 12 downregulated genes >2-fold. A gene set enrichment analysis (GSEA) on DL-PCB treated PBMCs resulted in an upregulation of 125 gene sets and a downregulation of 76 gene sets. Predominantly downregulated gene sets were involved in immunological pathways (such as response to virus, innate immune response, defense response). An upregulation of pathways related to oxidative stress could be observed for all PCB congeners except PCB-28; the latter congener dysregulated the least number of genes. Our experiment augments the information known about immunological and cellular stress responses following DL- as well as NDL-PCB exposure and provides new information on PCB 28. Further studies should be performed to evaluate how disruption of these pathways contributes to the development of autoimmune diseases and cancer.

Expression of CYP1A1, CYP1B1 and IL-1ß in PBMCs and skin samples of PCB exposed individuals.

Polychlorinated biphenyls (PCBs) are well- known man-made persistent environmental pollutants and endocrine disruptors. As a result of mass production in the past, background levels of these compounds can be measured in human blood worldwide. In 2010 high internal levels of PCBs were discovered in workers of a transformer-recycling company in Germany. Our aim was to measure, whether the expression of CYP1A1, CYP1B1, and IL-1ß is dysregulated in peripheral blood mononuclear cells (PBMCs) of the exposed individuals (n = max 308). Further, we measured the regulation of CYP1A1, CYP1B1, AHRR (aromatic hydrocarbon receptor repressor) and IL-1ß in skin samples of 25 workers with elevated plasma PCB levels using quantitative PCR (q-RT-PCR). We found a significant correlation between the regulation of IL-1ß in skin samples and lipid adjusted PCB levels. In the PBMCs, the expression levels of CYP1A1, CYP1B1 and IL-1ß decreased over time with decreasing PCB plasma levels. The upregulation of the cytokine IL-1ß in exposed individuals with higher PCB plasma levels warrants further investigation in order to examine its role in the pathophysiology of autoimmune disorders and tumor promotion.

Macrophage migration inhibitory factor protects from nonmelanoma epidermal tumors by regulating the number of antigen-presenting cells in skin.

The response of the skin to harmful environmental agents is shaped decisively by the status of the immune system. Keratinocytes constitutively express and secrete the chemokine-like mediator, macrophage migration inhibitory factor (MIF), more strongly than dermal fibroblasts, thereby creating a MIF gradient in skin. By using global and epidermis-restricted Mif-knockout (Mif-/- and K14-Cre+/tg; Miffl/fl) mice, we found that MIF both recruits and maintains antigen-presenting cells in the dermis/epidermis. The reduced presence of antigen-presenting cells in the absence of MIF was associated with accelerated and increased formation of nonmelanoma skin tumors during chemical carcinogenesis. Our results demonstrate that MIF is essential for maintaining innate immunity in skin. Loss of keratinocyte-derived MIF leads to a loss of control of epithelial skin tumor formation in chemical skin carcinogenesis, which highlights an unexpected tumor-suppressive activity of MIF in murine skin.-Brocks, T., Fedorchenko, O., Schliermann, N., Stein, A., Moll, U. M., Seegobin, S., Dewor, M., Hallek, M., Marquardt, Y., Fietkau, K., Heise, R., Huth, S., Pfister, H., Bernhagen, J., Bucala, R., Baron, J. M., Fingerle-Rowson, G. Macrophage migration inhibitory factor protects from nonmelanoma epidermal tumors by regulating the number of antigen-presenting cells in skin.

Synthesis of a Sulfonimidamide-Based Analog of Tasisulam and Its Biological Evaluation in the Melanoma Cell Lines SKMel23 and A375.

Tasisulam is a promising antitumor agent with complex pharmacology, which is used as an antiproliferative agent in patients with metastatic melanoma and other solid tumors. Phase 2 melanoma studies showed promising results but had to be stopped because of insufficient tasisulam clearance leading to toxic side effects. To reduce the negative effects of tasisulam, we synthesized a novel sulfonimidamide-based analog to evaluate its antiproliferative effects in comparison to the original compound by performing a cell proliferation assay in melanoma cell lines SKMel23 and A375. The results revealed that the analog had inhibitory effects on the proliferation comparable to tasisulam in both investigated cell lines. These results could contribute to a reduced toxicity of tasisulam and lead to further clinical trials in metastatic melanoma.