scholarly journals Molecular Mapping of Hydrogen Sulfide Targets in Normal Human Keratinocytes

2020 ◽  
Vol 21 (13) ◽  
pp. 4648
Author(s):  
Olivia Gross-Amat ◽  
Marine Guillen ◽  
Jean-Pascal Gimeno ◽  
Michel Salzet ◽  
Nicolas Lebonvallet ◽  
...  
Keyword(s):  
Molecular Mapping ◽  
Interleukin 1 ◽  
Human Keratinocytes ◽  
Thermal Waters ◽  
Cell Sheets ◽  
Experimental Conditions ◽  
Normal Human Keratinocytes ◽  
Global Mapping ◽  
Normal Human ◽  
Molecular Effects

Although sulfur-rich thermal waters have ancestrally been used in the context of dermatological conditions, a global mapping of the molecular effects exerted by H2S on human keratinocytes is still lacking. To fill this knowledge gap, we subjected cultured human keratinocytes to distinct amounts of the non-gaseous hydrogen sulfur donor NaHS. We first checked that H2S accumulated in the cytoplasm of keratinocytes under our experimental conditions andused a combination of proteomics, genomics and biochemical approaches to unravel functionally relevant H2S targets in human keratinocytes. We found that the identified targets fall into two main categories: (i) the oxidative stress response molecules superoxide dismutase 2 (SOD2), NAD(P)H quinone dehydrogenase 1 (NQO1) and culin 3 (CUL3) and (ii) the chemokines interleukin-8 (IL-8) and CXCL2. Interestingly, NaHS also stimulated the caspase-1 inflammasome pathway, leading to increased secretion of the pro-inflammatory molecule interleukin-18 (IL-18). Interestingly, the secretion of interleukin-1 beta (IL-1β) was only modestly impacted by NaHS exposure despite a significant accumulation of IL-1β pro-form. Finally, we observed that NaHS significantly hampered the growth of human keratinocyte progenitors and stem cells cultured under clonogenic conditions or as epidermal cell sheets. We conclude that H2S exerts specific molecular effects on normal human keratinocytes.

scholarly journals Human keratinocytes contain mRNA indistinguishable from monocyte interleukin 1 alpha and beta mRNA. Keratinocyte epidermal cell-derived thymocyte-activating factor is identical to interleukin 1.

1986 ◽  
Vol 164 (6) ◽  
pp. 2095-2100 ◽  
Author(s):  
T S Kupper ◽  
D W Ballard ◽  
A O Chua ◽  
J S McGuire ◽  
P M Flood ◽  
...  
Keyword(s):  
Epidermal Cell ◽  
Human Peripheral Blood ◽  
Interleukin 1 ◽  
Human Keratinocytes ◽  
Blood Monocytes ◽  
Peripheral Blood Monocytes ◽  
S1 Nuclease ◽  
Normal Human Keratinocytes ◽  
Nuclease Protection Assay ◽  
Normal Human

Keratinocytes produce an IL-1 like factor termed epidermal cell-derived thymocyte-activating factor (ETAF). In this study, we show that ETAF and IL-1 are identical by the following criteria: Both normal and malignant human keratinocytes contain mRNAs identical to monocytic IL-1 alpha and IL-1 beta mRNA, as determined by an S1 nuclease protection assay; and IL-1 activity in medium conditioned by these cells can be neutralized by antibodies specific for human IL-1. The IL-1 alpha and IL-1 beta mRNAs can be identified in cultured human keratinocytes in the absence of identifiable stimulation; this basal level of mRNA can be further induced to accumulate with certain defined stimuli. Cultured normal human keratinocytes (HFKs) contain 2-4 times more IL-1 alpha than IL-1 beta mRNA; in contrast, human peripheral blood monocytes contain 10-20 times more IL-1 beta than IL-1 alpha mRNA. The IL-1 activity released by these HFK can be neutralized by an antibody that neutralizes both alpha and beta IL-1, but not by an antibody that neutralizes only IL-1 beta. While human monocytes produce a large excess of IL-1 beta after appropriate stimulation, these data suggest that IL-1 alpha is a major (and may be the predominant) form of IL-1 produced by human keratinocytes.

scholarly journals UVB-mediated activation of p38 mitogen-activated protein kinase enhances resistance of normal human keratinocytes to apoptosis by stabilizing cytoplasmic p53

2002 ◽  
Vol 365 (1) ◽  
pp. 133-145 ◽  
Author(s):  
Nadine CHOUINARD ◽  
Kristoffer VALERIE ◽  
Mahmoud ROUABHIA ◽  
Jacques HUOT
Keyword(s):  
Adaptive Response ◽  
Human Keratinocytes ◽  
Dominant Negative ◽  
Mitogen Activated Protein Kinase ◽  
Dominant Negative Mutant ◽  
Normal Human Keratinocytes ◽  
Mitogen Activated Protein ◽  
Normal Human ◽  
Induced Apoptosis ◽  
Negative Mutant

Human keratinocytes respond to UV rays by developing a fast adaptive response that contributes to maintaining their functions and survival. We investigated the role of the mitogen-activated protein kinase pathways in transducing the UV signals in normal human keratinocytes. We found that UVA, UVB or UVC induced a marked and persistent activation of p38, whereas c-Jun N-terminal kinase or extracellular signal-regulated kinase were less or not activated respectively. Inhibition of p38 activity by expression of a dominant-negative mutant of p38 or with SB203580 impaired cell viability and led to an increase in UVB-induced apoptosis. This sensitization to apoptosis was independent of caspase activities. Inhibition of p38 did not sensitize transformed HaCaT keratinocytes to UVB-induced apoptosis. In normal keratinocytes, expression of a dominant-negative mutant of p53 increased UVB-induced cell death, pointing to a role for p53. In these cells, UVB triggered a p38-dependent phosphorylation of p53 on Ser-15. This phosphorylation was associated with an SB203580-sensitive accumulation of p53, even in the presence of a serine phosphatase inhibitor. Accumulated p53 was localized mainly in the cytoplasm, independently of CRM1 nuclear export. In HaCaT cells, p53 was localized exclusively in the nucleus and its distribution and level were not affected by UVB or p38 inhibition. However, UVB induced an SB203580-insensitive phosphorylation on Ser-15 of mutated p53. Overall, our results suggest that, in normal human keratinocytes, protection against UVB depends on p38-mediated phosphorylation and stabilization of p53 and is tightly associated with the cytoplasmic sequestration of wild-type p53. We conclude that the p38/p53 pathway plays a key role in the adaptive response of normal human keratinocytes against UV stress.

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