scholarly journals Ultraviolet B, melanin and mitochondrial DNA: Photo-damage in human epidermal keratinocytes and melanocytes modulated by alpha-melanocyte-stimulating hormone

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 881 ◽  
Author(s):  
Markus Böhm ◽  
Helene Z. Hill
Keyword(s):  
Mitochondrial Dna ◽  
Copy Number ◽  
Cell Types ◽  
Ultraviolet B ◽  
Epidermal Keratinocytes ◽  
Human Epidermal Keratinocytes ◽  
Mtdna Damage ◽  
Melanocyte Stimulating Hormone ◽  
Copy Numbers ◽  
Stimulating Hormone

Alpha-melanocyte-stimulating hormone (alpha-MSH) increases melanogenesis and protects from UV-induced DNA damage. However, its effect on mitochondrial DNA (mtDNA) damage is unknown. We have addressed this issue in a pilot study using human epidermal keratinocytes and melanocytes incubated with alpha-MSH and irradiated with UVB. Real-time touchdown PCR was used to quantify total and deleted mtDNA. The deletion detected encompassed the common deletion but was more sensitive to detection. There were 4.4 times more mtDNA copies in keratinocytes than in melanocytes. Irradiation alone did not affect copy numbers. Alpha-MSH slightly increased copy numbers in both cell types in the absence of UVB and caused a similar small decrease in copy number with dose in both cell types. Deleted copies were nearly twice as frequent in keratinocytes as in melanocytes. Alpha-MSH reduced the frequency of deleted copies by half in keratinocytes but not in melanocytes. UVB dose dependently led to an increase in the deleted copy number in alpha-MSH-treated melanocytes. UVB irradiation had little effect on deleted copy number in alpha-MSH-treated keratinocytes. In summary, alpha-MSH enhances mtDNA damage in melanocytes presumably by increased melanogenesis, while α-MSH is protective in keratinocytes, the more so in the absence of irradiation.

scholarly journals Mitochondrial DNA Heteroplasmy as an Informational Reservoir Dynamically Linked to Metabolic and Immunological Processes Associated with COVID-19 Neurological Disorders

2021 ◽  
Author(s):  
George B. Stefano ◽  
Richard M. Kream
Keyword(s):  
Mitochondrial Dna ◽  
Mitochondrial Function ◽  
Neurological Disorders ◽  
Nuclear Dna ◽  
Mitochondrial Dynamics ◽  
Cell Types ◽  
Tissue Specific ◽  
Copy Numbers ◽  
The Central Nervous System ◽  
Mitochondrial Dna Heteroplasmy

AbstractMitochondrial DNA (mtDNA) heteroplasmy is the dynamically determined co-expression of wild type (WT) inherited polymorphisms and collective time-dependent somatic mutations within individual mtDNA genomes. The temporal expression and distribution of cell-specific and tissue-specific mtDNA heteroplasmy in healthy individuals may be functionally associated with intracellular mitochondrial signaling pathways and nuclear DNA gene expression. The maintenance of endogenously regulated tissue-specific copy numbers of heteroplasmic mtDNA may represent a sensitive biomarker of homeostasis of mitochondrial dynamics, metabolic integrity, and immune competence. Myeloid cells, monocytes, macrophages, and antigen-presenting dendritic cells undergo programmed changes in mitochondrial metabolism according to innate and adaptive immunological processes. In the central nervous system (CNS), the polarization of activated microglial cells is dependent on strategically programmed changes in mitochondrial function. Therefore, variations in heteroplasmic mtDNA copy numbers may have functional consequences in metabolically competent mitochondria in innate and adaptive immune processes involving the CNS. Recently, altered mitochondrial function has been demonstrated in the progression of coronavirus disease 2019 (COVID-19) due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Accordingly, our review is organized to present convergent lines of empirical evidence that potentially link expression of mtDNA heteroplasmy by functionally interactive CNS cell types to the extent and severity of acute and chronic post-COVID-19 neurological disorders.

scholarly journals Impact on Autophagy and Ultraviolet B Induced Responses of Treatment with the MTOR Inhibitors Rapamycin, Everolimus, Torin 1, and pp242 in Human Keratinocytes

2017 ◽  
Vol 2017 ◽  
pp. 1-21 ◽  
Author(s):  
Song Xu ◽  
Li Li ◽  
Min Li ◽  
Mengli Zhang ◽  
Mei Ju ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Cellular Response ◽  
Mtor Inhibitors ◽  
Mtor Signaling ◽  
Ultraviolet B ◽  
Epidermal Keratinocytes ◽  
Human Epidermal Keratinocytes ◽  
Mtor Inhibition ◽  
The Impact ◽  
Uva Radiation

The mechanistic target of Rapamycin (MTOR) protein is a crucial signaling regulator in mammalian cells that is extensively involved in cellular biology. The function of MTOR signaling in keratinocytes remains unclear. In this study, we detected the MTOR signaling and autophagy response in the human keratinocyte cell line HaCaT and human epidermal keratinocytes treated with MTOR inhibitors. Moreover, we detected the impact of MTOR inhibitors on keratinocytes exposed to the common carcinogenic stressors ultraviolet B (UVB) and UVA radiation. As a result, keratinocytes were sensitive to the MTOR inhibitors Rapamycin, everolimus, Torin 1, and pp242, but the regulation of MTOR downstream signaling was distinct. Next, autophagy induction only was observed in HaCaT cells treated with Rapamycin. Furthermore, we found that MTOR signaling was insensitive to UVB but sensitive to UVA radiation. UVB treatment also had no impact on the inhibition of MTOR signaling by MTOR inhibitors. Finally, MTOR inhibition by Rapamycin, everolimus, or pp242 did not affect the series of biological events in keratinocytes exposed to UVB, including the downregulation of BiP and PERK, activation of Histone H2A and JNK, and cleavage of caspase-3 and PARP. Our study demonstrated that MTOR inhibition in keratinocytes cannot always induce autophagy, and the MTOR pathway does not play a central role in the UVB triggered cellular response.

Effects of Sulfur Mustard on Cytokines Released from Cultured Human Epidermal Keratinocytes

1998 ◽  
Vol 17 (3) ◽  
pp. 223-229 ◽  
Author(s):  
Elien M. Kurt ◽  
Robert J. Schafer ◽  
Carmen M. Arroyo
Keyword(s):  
Sulfur Mustard ◽  
Cell Types ◽  
Epidermal Keratinocytes ◽  
Cytokine Release ◽  
Experimental Conditions ◽  
Human Epidermal Keratinocytes ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Cytokine Levels ◽  
Factor Alpha

The release of the cytokines interleukin (IL)-1α, IL-1β, IL-6, IL-8, and tumor necrosis factor alpha (TNF-α was measured from epiderm alkeratinocytes in an attempt to characterize the immunologic response in keratinocytes following exposure to bis (2-chloroethyl)sulfide (sulfur mustard, HD). Enzyme-linked immunosorbentassay (ELISA) was used to measure cytokine levels in adult and neonatal culture human epidermal keratinocytes (HEK) 3 h after exposure to 0.50 and 1.0 m M HD. A two-way analysis of variance was carried out for cell type and HD concentration. That analysis showed significant differences between cell types for IL-1α and IL-1β(p =.001 and p =.015, respectively). In both of these cytokines, release in neonatal HEK decreased less than in adult HEK. A significant effectof HD concentration was shown only for IL-1β (P <.001), with cytokine release decreasing with increasing HD dose. In addition, a significant cell donor type by HD concentration interaction effect was found for IL-1β under the experimental conditions described in materials and methods. With increasing HD concentration, the relative decrease in cytokine release was much greater for adult than for neonatal HEK.

Dichotomous effect of ultraviolet B on the expression of corneodesmosomal enzymes in human epidermal keratinocytes

2009 ◽  
Vol 54 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Megumi Nin ◽  
Norito Katoh ◽  
Satoshi Kokura ◽  
Osamu Handa ◽  
Toshikazu Yoshikawa ◽  
...  
Keyword(s):  
Ultraviolet B ◽  
Epidermal Keratinocytes ◽  
Human Epidermal Keratinocytes
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