Skip to main content
NCBI home page
NIHPA Author Manuscripts logoLink to NIHPA Author Manuscripts
. Author manuscript; available in PMC: 2022 Feb 4.
Published in final edited form as: J Dermatol Sci. 2020 Nov 5;101(1):40–48. doi: 10.1016/j.jdermsci.2020.11.001

Ethanol Consumption Synergistically Increases Ultraviolet Radiation Induced Skin Damage and Immune Dysfunction.

Rhonda M Brand 1,2,3,*, John Mark Stottlemyer 1, Melissa C Paglia 1, Cara Donahue Carey 1, Louis D Falo Jr 1,4,5,6,7
PMCID: PMC8815307  NIHMSID: NIHMS1647222  PMID: 33213984

Abstract

Background:

Excessive UV radiation disrupts skin homeostasis by multiple mechanisms that extend beyond the simple erythema associated with sunburns including reduction of antioxidants, increased DNA damage, and impairment of skin immune responses. Recreational UV exposure frequently occurs concurrently with excessive ethanol (EtOH). Epidemiological studies suggest a harmful, dose-dependent impact of EtOH in the setting of high UV exposure, leading to increased severity of sunburns relative to those generated in the absence of ethanol. Furthermore, EtOH consumption and UV radiation have multiple overlapping effects on the skin that could account for the epidemiological association.

Objective:

To elucidate the relationship between excessive EtOH ingestion and UV exposures on early skin damage and downstream immune dysfunction.

Methods:

We examined the impact of UVB on local skin damage, including inflammation, sunburned cells, apoptotic cells, melanin and antioxidant levels, DNA damage and immune dysfunction in the presence or absence of EtOH ingestion by combining standard mouse models of EtOH consumption and UVB exposure models. To confirm that the observed changes in mouse skin were relevant to human skin, we investigated the effects of EtOH on UV-induced skin damage with human skin explants.

Results:

We demonstrated that EtOH consumption and UV exposure act synergistically to increase the severity of local skin damage resulting in impaired melanin responses, reduced antioxidants, greater DNA damage, and immune dysfunction as measured by reduced contact hypersensitivity.

Conclusions:

The results support incorporation of the risks of combined UV exposure and excessive alcohol consumption into public health campaigns.

1. Introduction

Excessive UV exposure disrupts skin homeostasis, overwhelming the skin’s natural antioxidant defenses, generating reactive oxygen species, causing both direct and indirect DNA damage, inducing apoptotic responses and inhibiting contact hypersensitivity responses [1], all of which have been associated with an increased incidence of skin cancer. Reducing UV-induced skin damage thus has become a public health priority with programs that focus on modifications of lifestyle factors including reducing UV exposure, applying sunscreens, and wearing protective clothing [2, 3]. Ethanol (EtOH) ingestion often occurs in tandem with recreational UV exposure, so the combined effects of EtOH ingestion and UV exposure on skin may have important public health implications.

Several studies suggest that simultaneous UV exposure and EtOH consumption produce higher rates of sunburn than would be expected by UV alone [4–6], While this could be solely a result of EtOH-induced behavioral changes, such as spending increasing time in the sun, one study determined that drinking EtOH even without increased sun exposure caused greater sunburn pain, larger sunburned body surface area, and increased risk for developing blisters [7]. Furthermore, EtOH ingestion prior to UV exposure reduced both the minimal erythema dose (MED) and skin concentration of carotenoids [8]. This MED reduction was mitigated by mixing the EtOH with antioxidant rich orange juice [8] or by drinking red wines containing high levels of antioxidant polyphenols [9]. Taken together, these studies support the concept that EtOH ingestion can increase adverse events associated with UV exposure. Elucidating the mechanisms responsible for this relationship has been difficult as confounding factors cannot be excluded [10].

EtOH metabolites and UV radiation (UVB) share several downstream effects that may explain the observed interactions between MED and sunburns. Excessive UV induces extensive skin damage through mechanisms ranging from generation of direct DNA damage, including cyclobutane pyrimidine dimers (CPD), to indirect DNA damage resulting from UV-induced reactive oxygen species (ROS) such as 8-oxoguanine (8-OxoG) [1]. Alcohol consumption generates skin EtOH levels sufficient to impair local barrier function, alter blood flow, induce lipid peroxidation [11], interfere with skin dendritic cell (DC) functionality [12, 13], impede skin wound healing after thermal burns [14] and S. Aureus infections [15], and induce the EtOH metabolizing enzymes EtOH dehydrogenase and aldehyde dehydrogenase [11]. Similar to UVB, the EtOH metabolite acetaldehyde causes DNA damage, including DNA methylation and adduct formation that impacts proteins, causes lipid peroxidation and nucleic acid oxidation, and is strongly immunosuppressive [16]. Travers, et al. demonstrated that the lipid mediator platelet-activating factor (PAF), which facilitates systemic immunosuppression induced by many environmental toxins, is enhanced by the combination of EtOH with UVB or thermal burns [17, 18]. The wide-ranging effects of EtOH ingestion on the skin warrant further investigation to understand relationships in the context of the well- known effects of UVB overexposure.

We hypothesized that the observed correlations between EtOH consumption and severity of UV induced skin damage could be explained by overlapping mechanisms of action. We therefore used well-established mouse models to directly examine the impact of drinking patterns on UV induced skin damage and immune dysfunction. We demonstrated synergism between the two exposures in the impairment of melanin responses and reduction of antioxidants, leading to increased DNA damage and local immune suppression. Understanding the interactions between EtOH ingestion and UV exposure and elucidating mechanistic synergies could have clinical and public health implications, with direct impact on individuals with significant recreational and occupational UV exposures.

2. Materials and methods

2.1. EtOH ingestion

For chronic EtOH consumption, female C57BL/6 mice (6–8 weeks) were pair-fed a nutritionally adequate Lieber-DeCalrli liquid or control diet with EtOH substituted isocalorically with dextrin maltose (Bio-Serve, Frenchtown, NJ). EtOH was introduced gradually by increasing the content from 1% for 2 days to 3 % for 2 days and then 5% (vol/vol) EtOH for the remainder of the experiment. Mice are nocturnal and thus consume most EtOH at night; given its rapid metabolism, serum EtOH levels vary widely throughout the day. This feeding regime produced a non-peak, early morning blood EtOH level of 0.14% [19]. Acute/binge EtOH use was modeled by gavaging mice with 5g/kg EtOH from a 32% solution or water, which generated a peak blood level of approximately 0.25–0.30% at 30 minutes [20].

2.2. UV exposure

All studies used Westinghouse FS72T12/UVB lamps (UV Resources International), which emits approximately 80% UVB (280–320nm) and 20% UVA (320–375 nm) with a peak output at 314 nm [21]. The dose was monitored with a UVB meter (UVB-500C, National Biological Corp).

2.3. Immune suppression studies

Immune suppression was measured by treating chronic, acute/binge EtOH or control mice with a contact hypersensitivity (CHS) protocol designed to study UV-induced immune suppression [22]. For four consecutive days, mice were shaved, and ears were covered with black electrical tape prior to exposure to 100mJ/cm2 UVB. On day five, mice were sensitized by placing 1% of the contact allergen oxazolone (OXA) on the abdomen. Ears were elicited on day ten, with 1% OXA and ear swelling measured 24 hours later. All data were presented as % increase in thickness, determined using the equation ((Treated Thickness – Control Thickness)/ Control Thickness)*100 [23].

2.4. Acute UV-induced damage in mouse skin

Mice were depilated five days prior to gavage with either 5g/kg EtOH or a water control. Thirty minutes after gavage, corresponding to peak EtOH levels [20], mice were treated with a single 100mJ/cm2 UVB or sham radiation.

Inflammation:

Inflammation was determined in H&E stained sections by measuring dermal and epidermal thickening and cellular infiltrate. Five images were taken of each slide, with epidermal thickness (400x) measured from the outer edge to the epidermal-dermal interface or dermal thickness from dermal-epidermal junction to fatty layer (100X) using Image J Software (NIH). Cellular infiltrate was determined by visually counting the number of cells in a 100,000-pixel area (400X) on each of the five images. The five images were averaged to determine a single value for each animal [24].

Melanin:

Total melanin production was measured by solubilizing a punch biopsy in 1 M NaOH, incubating at 37°C for 96 hours, extracting with chloroform, and centrifuging again at 6500 g for 10 min, and the absorption read at 414 m with synthetic melanin as a standard [25].

Sunburned/Apoptotic Cells:

Epidermal cells containing pyknotic nuclei and eosinophilic cytoplasm were counted in H&E stained sections. To confirm the presence of epidermal apoptotic cells, paraffin embedded sections were analyzed by TUNEL assay (DermaTACS, Trevigen, Gaithersburg MD) and counterstained with Nuclear Red (Vector Laboratories, Burlingame CA). The percent of sunburned/apoptotic cells was quantitated by counting five fields at 400X and averaging results to obtain a single value per sample.

Oxidative Stress:

DNA damage was determined by staining sections for 8-oxo and CPD by immunohistochemistry using Polyclonal Goat anti 8-Hydroxyguanosine primary antibody (Abcam, ab10802) and Anti-Thymine Dimer mAb (clone KTM53) and quantitated as described earlier.

Glutathione (GSH) levels in supernatant from skin homogenates were measured using GSH–glo assay kits. (Promega, Madison, WI). For each skin sample, a 6 mm punch biopsy was homogenized in 300 ul of PBS+2mM EDTA and centrifuged at 1000g for 10 minutes and assayed following manufacturer’s instructions [24].

2.5. Acute UV-induced damage in human skin explants

Neonatal foreskins were obtained from circumcisions, divided into four pieces, and assigned to control alone, EtOH alone, control + UV, or EtOH + UV groups. Explants were cultured epidermal-side up, resting on sterile stainless-steel mesh screens placed inside 6 well plates filled with serum-free Aim V medium and cultured overnight at the air/liquid interface [24]. Two hours prior to UV radiation, 50mM EtOH (0.23%) was added to the media, explants were removed from the mesh, exposed to 200mJ/cm2 UVB or sham irradiation, returned to the original culture for 24 hours and then assayed as described for mouse skin.

2.6. Statistical analysis

Data are presented as % control or actual values (mean ± s.e.m). To determine if EtOH + UV generate a synergistic change versus individual components, the “difference of the difference” was calculated by comparing (UV minus Naive) versus (ETOH+UV minus ETOH ) for statistical analysis and by employing unpaired t-tests for mouse studies and paired t-tests for human skin explants. All calculations were performed using GraphPad Prism (GraphPad, La Jolla, CA).

3. Results

3.1. Alcohol ingestion augments UV-related immune suppression

To better understand the impact of EtOH drinking patterns on interactions with UVB-related immune suppression, mice received either chronic or acute/binge EtOH. The studies began by pair feeding mice with chronic 5% EtOH, for 6 days [26], to model people who drink throughout the UV exposure period and then continue drinking after they have moved indoors. Once a chronic level of EtOH was established, the CHS protocol described in section 2.3 was implemented. Ear thickness measured 24 hours after elicitation directly reflected the level of immune responsiveness [22]. As observed in Figure 1a, no significant differences in ear thickness were observed between the naïve control and EtOH-fed animals never exposed to OXA (Naive and EtOH). EtOH ingestion and UV exposure significantly impaired CHS responses as determined by ear swelling compared to control diet (OXA versus EtOH OXA, OXA versus UV OXA). Combined UV exposure and EtOH ingestion resulted in significant reductions of CHS compared to either alone (UV OXA or EtOH OXA versus EtOH+UV OXA) To determine if combined exposure inhibits CHS in an additive or synergistic manner, the “difference of the difference” was calculated by comparing (EtOH-UV OXA) to (EtOH- EtOH+UV OXA). In the case of an additive response, similar values were expected, however a synergistic response would generate significantly different values. The observation of significantly different responses supportedthe conclusion that the combination of UV and EtOH exposure increased immune suppression severity in a synergistic manner (Figure 1a).

Figure 1-. CHS inhibition by UV is augmented in the setting of alcohol consumption.

Figure 1-

Open in a new tab

CHS response to topically applied OXA +/− UV exposure, +/− EtOH ingestion, or both was determined. Mice were exposed to 100mJ/ daily for 4 days where indicated and were sensitized 1 day later with 1% OXA. CHS responses were determined when alcohol was given (a) continuously, beginning 1 week before UV, (b) by gavage 30 min prior to UV exposure on days 1–4 to mimic binge drinking during UV exposure, or (c) by gavage 30 min prior to UV exposure on day 1 only. Synergism was determined by comparing (EtOH OXA minus UV OXA) versus (EtOH OXA minus (EtOH+UV) OXA). Significance was determined using an unpaired t-test (n=5–10).

To expand these studies to represent people drinking primarily during sun exposure, EtOH was provided only during the UV exposure period. Mice were gavaged 30 minutes prior to each UV treatment and CHS protocol was similarly evaluated (Figure 1b). Both EtOH and UV individually inhibited CHS. As with the continuous diet, the combination demonstrated a significantly greater immune suppression than the individual components, again supporting synergistic interactions. Next, to determine whether EtOH must be present throughout the entire UV exposure period to trigger immune suppression, EtOH was provided only on the first day of UV exposure. Both EtOH and UV alone groups exhibited immune suppression and a significant synergistic reaction between EtOH consumption and UV occurred under these conditions (Figure 1c). Thus, ingestion of EtOH early in the UV exposure process is sufficient to increase UV-related immune suppression.

3.2. ETOH consumption enhances UV-induced inflammation

The skin responds to excessive UV radiation with epidermal hyperplasia, edema, and an inflammatory cell infiltrate [27]. To determine if EtOH consumption augmented these UV effects, epidermal and dermal thickening, and inflammatory infiltrates in H&E stained sections were measured 24 hours after UV exposure as described earlier (Figures 2a (100x) & 3a (400x)) [24]. UV alone significantly increased each parameter, whereas EtOH alone showed minor increases (Figures 2b–d). Combining UV and EtOH-feeding synergistically increased inflammatory changes beyond those observed with UV alone.

Figure 2-. ETOH consumption augments UV-induced inflammation.

Figure 2-

Open in a new tab

Mice were gavaged with 5g/kg EtOH or water 30 minutes prior to 100mJ/cm2 UVB. Representative H&E stained sections (100X) from skin sampled 24 hours after treatment are provided (a). Five measurements were taken per field and five fields were counted per sample. Results were averaged to obtain a single value per slide. Epidermal thickness was measured at 400x (fig 2a, 3a visual) and quantitated in (b) Dermal thickness measured at (100X) (a) was summarized in (c). Infiltrating cells ( figure 2a & 3a) were counted in five fields (400X) (figure 2a, 3a) per section and averaged to a single value (d). Synergism was determined by comparing (UV minus naive) versus (EtOH+UV minus EtOH). Significance was determined using an unpaired t-test (n=4–5).

Figure 3-. Apoptosis induced by UV radiation is increased after EtOH consumption.

Figure 3-

Open in a new tab

Mice were gavaged with 5g/kg ETOH or water 30 minutes prior to 100mJ/cm2 UVB. After 24 hours, the percentage of epidermal sunburned cells with pyknotic nuclei (a) in H&E stained sections were determined (400X). Insert contains expanded epidermal section to emphasize pyknotic nuclei. Representative TUNEL positive staining with apoptotic (blue) cells (400X) are presented in (b). Five 400x fields were counted per sample and results were averaged to obtain a single value per slide. Data are presented either % sunburn (c) or TUNEL (d) positive cells. Melanin levels (e) were quantitated by spectroscopy 24 hours after UV exposure in mice were depilated 5 days prior to treatment with 5 g/kg ETOH given via gavage 30 minutes prior to UVB (100mJ/cm2). Synergism was determined by comparing the direct effect of UV as a function of EtOH exposure by comparing (UV minus Naive) versus (ETOH+UV minus ETOH). Significance was determined using an unpaired t-test (n=4–6).

3.3. EtOH ingestion increases apoptosis after UV exposure

To confirm the observation that drinking EtOH with concurrent sun exposure leads to more severe sunburns [4–6], we examined H&E sections from mice 24 hours after UV+/−EtOH for classic sunburned cells. Tissue sections were quantitated as described earlier, revealing that ETOH+UV acted synergistically to increase sunburned cells to a greater extent than either UV or ETOH alone (Figure 3a,c). Sunburned cells are keratinocytes dying apoptotically after UV exposure [28]. Therefore, to confirm that classic sunburned cells reflect apoptotic cells, skin sections were stained for TUNEL positive cells, and the sections were quantitated as described earlier. Consistent with the H&E stained sections, EtOH consumption synergistically increased TUNEL positive cells (Figure 3b,d).

Increased apoptosis induced by EtOH ingestion is consistent with the concept that ETOH augments UV-induced DNA damage. Melanin is a photo protector that decreases UV-triggered DNA damage [1]; inhibition of melanogenesis is a possible mechanism by which EtOH consumption increases UV-induced DNA damage. To determine skin melanin levels in individual and combined exposure to UVB and EtOH, total melanin levels were spectrophotometrically quantitated [25]. Melanin increased 24 hours after UVB exposure, however high levels of EtOH in the bloodstream, concurrent with UVB exposure, interfered with normal melanin induction (Figure 3e). Inhibition of melanin synthesis by EtOH exposure likely contributed to the enhanced UV-related skin damage upon combined exposure.

3.4. DNA damage is augmented, and DNA repair is decreased after combined UVB and EtOH exposure

Both DNA damage and impaired DNA repair contribute to UV-related immune dysfunction, with CPD considered the key trigger for this immune suppression [29]. Therefore, a time course of CPD at 0.5, 6 and 24 hours post UV with EtOH ingestion was measured in mouse skin. Increased CPD positive cells in stained sections demonstrated that EtOH ingestion impaired normal DNA recovery (Figures 4a,c). In addition to direct DNA damage, ROS generated by UV produce multiple types of DNA damage. The major DNA oxidative lesion, 8-oxoG, pairs with adenine as well as cytosine during DNA replication, causing GC-TA transversion mutations that have been linked to carcinogenesis [30]. Therefore, skin samples were stained for 8-oxoG and quantitated as described earlier. EtOH increased 8-oxoG levels synergistically beyond those induced by UV alone (Figure 4b,d).

Figure 4-. DNA damage is augmented, and DNA repair is decreased after combined UVB and EtOH consumption.

Figure 4-

Open in a new tab

Mice were gavaged with 5g/kg EtOH or water 30 minutes prior to 100mJ/cm2 UVB. Skin samples were obtained 0.5, 6 or 24 hours post treatment. Sections were stained for DNA damage with antibodies to either CPD (a,c) or 8-oxoG (b,d). Five 400x fields were counted per sample and results were averaged to obtain a single value per slide. Data are presented as % positive cells. GSH (d) levels were determined in skin homogenates obtained 24 hours after UV exposure. GSH results are presented as % control. GSH synergism between EtOH ingestion and UV is by comparing (Naïve minus UV) versus (EtOH minus EtOH UV). Significance was determined with an unpaired t-test (n=3–8).

Since oxidative stress is responsible for the increased level of 8-oxoG DNA lesions, skin antioxidant levels after UVB and EtOH exposure were also determined. As glutathione is among the most abundant antioxidants present in the skin [24], this model antioxidant was used to further study the combined effects of UV and EtOH consumption on oxidative stress. GSH levels were reduced after UVB exposure; EtOH further augmented this loss in a synergistic manner (Fig 4c). Thus, combined EtOH and UVB exposure amplified direct and indirect DNA damage while simultaneously depleting antioxidant levels.

3.5. Joint ETOH and UV exposure increases DNA damage and decreases melanin production in human skin explants

Differences between murine and human skin dictate the need for further investigation of EtOH’s effects on UV-induced skin damage in human skin. Human foreskin was used as the skin source since it is easy to obtain and, since foreskins have never been previously exposed to UV radiation, they do not have any preexisting UV-related damage. Foreskin were place in culture at the air-liquid interface (+/− EtoH) for 2 hours, prior to UV irradiation. The resulting sunburned cells were quantitated using H&E stained slides from skin 24 hours post UV exposure (Figure 5a,c), while measurement of the apoptotic cells used the TUNEL stained slides (Figure b d). Combined EtOH and UV significantly increased direct DNA damage and oxidative stress as determined by CPD (Figure 5e) and 8-OxoG (Figure 5f), respectively, in human skin explants versus UV alone. Thus, as observed with mouse studies, both measurements of apoptosis indicated that EtOH and UV act synergistically.

Figure 5-. UV-related apoptosis and DNA damage are increased, while melanin production is decreased in the presence of EtOH in human skin explants.

Figure 5-

Open in a new tab

Neonatal foreskins were divided and exposed to +/− 50mM ETOH for 2 hours prior to UV exposure (200mJ/cm2 UVB) and were sampled 24 hours later. The percentage of epidermal sunburned cells with pyknotic nuclei (a,c) were determined in H&E sections from 24 hours post-UV exposure, while apoptotic cells (blue) were measured with TUNEL staining taken at 24 hours post-UV exposure (b,d). DNA damage was confirmed with antibodies to either CPD (e) or 8-oxoG (f). Five 400x fields were counted per sample and results were averaged to obtain a single value per slide. GSH (g) and melanin (h) levels were determined in skin homogenates obtained 24 hours after UV exposure. Significance was determined with an unpaired t-test (n=3–10).

The impact of combined UVB and EtOH treatments on skin defense mechanisms in human skin was consistent with results from mouse skin, as the protective antioxidant GSH was depleted after joint exposure versus UV alone (Figure 5g). Given the species differences between mice, where melanin is principally located in hair and hair follicles, and humans where melanin is also found in the basal epidermis, human skin explants provided an important secondary model to evaluate the impact of EtOH exposure on UV-induced DNA damage. The presence of 50mM (0.2%) EtOH in the culture media for 2 hours prior to UV exposure inhibited melanin induction. As for mouse skin, UV alone significantly increased melanin in human skin explants, while EtOH in the culture media prior to UV impaired this induction (Figure 5h). The data suggest that impaired melanin synthesis may be responsible for the clinically observed reduction in suntans in favor of increased sunburns when one consumes alcohol while outdoors [7].

4. Discussion

This study investigated the nature of the interrelationship between UVB and alcohol consumption by combining carefully-controlled, well-established mouse models for EtOH ingestion, UV-induced skin damage and CHS responses. EtOH ingestion patterns can vary greatly depending on social situations; thus, valuable information was revealed by studying the interactions between UVB and EtOH with chronic, daily binging, and single binging models. The resulting immune suppression was greater than would be expected if the two factors were independent, demonstrating synergistic interactions. This synergism was maintained in skin responses to UVB exposure including inflammation, DNA damage, antioxidant depletion, and the development of sunburned cells. The data suggest that upon UV exposure, ETOH and its metabolite acetaldehyde can increase DNA damage by impairing DNA repair and interfering with protective mechanisms such as melanin and antioxidants.

The skin has evolved protective mechanisms to prevent extensive damage from UV-radiation. Several chromophores, including DNA, trans UCA, membrane phospholipids, 7-dehydrcholesterol, tryptophan, and melanin present within the skin serve as the first line of defense against UV radiation, with DNA being the most abundant chromophore in the epidermis [31]. This study revealed that early melanin responses to UVB are impaired by EtOH consumption, thereby interfering with the skin’s ability to safely absorb UV. Excessive UV radiation leads to direct DNA damage with the generation of CPD and 6–4 photoproducts as well as oxidative stress. The accumulating ROS deplete the skin’s innate antioxidant capacity and when sufficient ROS cannot be neutralized, DNA oxidation, as characterized by 8-oxoG results [24]. After UVB generates DNA damage, the induction of DNA repair enzymes is critical, as unrepaired UV-induced DNA mutations are an important step in the induction skin damage [1, 32, 33]. Induced 8-oxoG lesions and impaired CPD repair, synergistically increased apoptotic cells, and reduced GSH levels after combined EtOH and UV exposure support the concept of ETOH-related excessive DNA damage.

The field of Photoimmunology established that UV exposure activates immune suppressor pathways instead of effector pathways upon antigen exposure leading to immune system dysfunction [32, 34, 35]. This immune suppression occurs with the photoisomerization of the chromophore trans-UCA to its cis-isomer (Cis-UCA) upon UV exposure [36]. Cis-UCA then binds to the 5HT-2A serotonin receptor [35], leading to intracellular ROS generation and oxidative DNA damage, PAF, histamine, PGE2, altered cytokine release, induction of apoptosis, cell growth arrest, antigen presentation impairment, stimulation of neuropeptides, and mast cell degranulation [31]. Similarly, skin membrane phospholipids also act as photoreceptors which, upon activation by both UV and EtOH, lead to PAF release UV [37, 38]. PAF and cis-UCA impair DNA repair through the nucleotide excision repair pathway (NER) [29], and studies with XPA and PAFR-deficient mice demonstrate that PAF contributes to both early proinflammatory and immunosuppressive responses to UVB [17, 39]. Furthermore, UV-induced infiltrating leukocytes, especially CD11b+ cells and tolerance inducing class II MHC+CD11b+ monocyte/macrophages contribute to immunosuppression via induction of the immunosuppressive cytokine IL-10 [40]. The synergistic induction of inflammatory cells observed after combined UV and EtOH are thus supportive of the synergistic reduction in CHS responses Both ingested EtOH and UVB generate local and systemic immune impairment, as evidenced by CHS inhibition, when antigen is applied to UV exposed and non-exposed sites [34]. UVB induces antigen specific immunotolerance, mediated through UVB-induced Treg that switch DC from a stimulatory to regulatory phenotype, contributing to UV-induced immunosuppression [41]. Similarly, EtOH exposures interferes with both the quantity and function of multiple skin T cell phenotypes [42, 43] and both the numbers and migration capacity of skin DCs [13, 31, 44], demonstrating that both UV exposure and EtOH generate skin immune dysfunction.

Previous studies demonstrated that EtOH ingestion impacted skin barrier function in a dose dependent manner [45]. Therefore, to maximize any potential interactions, these studies used a high peak EtOH dose that represents legal intoxication (0.14–0.3%). A limitation to this work is that dosing experiments resulting in lower peak blood EtOH levels were not performed. The ability of sunscreen to prevent synergism between EtOH and UVB was also not determined. Furthermore, studies only focused on early responses, which are often precursors to skin cancer development. With epidemiological studies suggesting that ethanol (EtOH) consumption, increases the relative risk for both melanoma [46–48] and non-melanoma skin cancers (NMSC) [48–50] in a dose-dependent manner the data presented support future experiments incorporating EtOH ingestion into a UVB induced mouse model of skin cancer.

This work demonstrated that EtOH consumption amplifies the negative impact of UVB on the skin in a synergistic manner. Inhibited melanin synthesis, increased DNA damage, impaired DNA repair, and greater immune suppression may explain the epidemiological correlations between EtOH use and skin cancer. These experimental results provide a basis for developing new tools to be used in educating people about the potentially dangerous implications of consuming excessive alcohol in the setting of UVB exposure.

Highlights:

  • Mouse models containing both EtOH abuse and UV exposure induces synergistic immune suppression.

  • Dual EtOH and UV synergistically amplify immune dysfunction and local skin damage

  • Skin changes induced by UV combined with EtOH are consistent between mice and humans

  • Results support epidemiological correlations between EtOH use and skin cancer.

  • Provides basis for education about dangers of combining excess EtOH and UV exposure.

Acknowledgements:

The authors would like to thank Drs. Patricia Eagan and Jaideep Behari for their insightful discussions about physiological effects of alcohol abuse and Drs. Adrianna Larrengina, Alicia Mathers and Tina Sumpter for their assistance with the dermatological components of the study. This work was supported by NIH 1KO1AA017907 and 3K01AA017907-01S1.

Funding

This work was supported by NIH 1KO1AA017907 and 3K01AA017907-01S1

Footnotes

Author declaration

None

Conflict of Interest

The authors have no conflict of interest to declare.

Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

References

  • [1].Brand RM, Wipf P, Durham A, Epperly MW, Greenberger JS, Falo LD Jr., Targeting Mitochondrial Oxidative Stress to Mitigate UV-Induced Skin Damage, Front Pharmacol 9 (2018) 920. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [2].Kalia S, Kwong YKK, Relationship between sun safety behaviours and modifiable lifestyle cancer risk factors and vitamin D levels, Photodermatol Photoimmunol Photomed 35(6) (2019) 429–435. [DOI] [PubMed] [Google Scholar]
  • [3].Rivers J, A cocktail for skin cancer: why alcohol and sun exposure do not mix, Journal of cutaneous medicine and surgery 18(4) (2014) 217–20. [DOI] [PubMed] [Google Scholar]
  • [4].Mukamal KJ, Alcohol consumption and self-reported sunburn: a cross-sectional, population-based survey, J Am Acad Dermatol 55(4) (2006) 584–9. [DOI] [PubMed] [Google Scholar]
  • [5].Brown TT, Quain RD, Troxel AB, Gelfand JM, The epidemiology of sunburn in the US population in 2003, Journal of the American Academy of Dermatology 55(4) (2006) 577–583. [DOI] [PubMed] [Google Scholar]
  • [6].Holman DM, Berkowitz Z, Guy GP Jr., Hartman AM, Perna FM, The association between demographic and behavioral characteristics and sunburn among U.S. adults - National Health Interview Survey, 2010, Prev Med 63 (2014) 6–12. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [7].Warthan MM, Sewell DS, Marlow RA, Warthan ML, Wagner RF Jr., The economic impact of acute sunburn, Archives of Dermatology 139(8) (2003) 1003–6. [DOI] [PubMed] [Google Scholar]
  • [8].Darvin ME, Sterry W, Lademann J, Patzelt A, Alcohol consumption decreases the protection efficiency of the antioxidant network and increases the risk of sunburn in human skin, Skin Pharmacol Physiol 26(1) (2013) 45–51. [DOI] [PubMed] [Google Scholar]
  • [9].Moehrle M, Dietrich H, Patz CD, Häfner H-M, Sun protection by red wine?, JDDG: Journal der Deutschen Dermatologischen Gesellschaft 7(1) (2009) 29–32. [DOI] [PubMed] [Google Scholar]
  • [10].Rota M, Evidence for an association between alcohol intake and an increased risk of nonmelanoma skin cancer, Br J Dermatol 177(3) (2017) 611–612. [DOI] [PubMed] [Google Scholar]
  • [11].Brand RM, Jendrzejewski JL, Chronic ethanol ingestion alters xenobiotic absorption through the skin: potential role of oxidative stress, Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association 46(6) (2008) 1940–8. [DOI] [PubMed] [Google Scholar]
  • [12].Edsen-Moore MR, Fan J, Ness KJ, Marietta JR, Cook RT, Schlueter AJ, Effects of chronic ethanol feeding on murine dendritic cell numbers, turnover rate, and dendropoiesis, Alcoholism, clinical and experimental research 32(7) (2008) 1309–20. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [13].Parlet CP, Schlueter AJ, Mechanisms by Which Chronic Ethanol Feeding Impairs the Migratory Capacity of Cutaneous Dendritic Cells, Alcoholism: Clinical and Experimental Research 37(12) (2013) 2098–2107. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [14].Fitzgerald DJ, Radek KA, Chaar M, Faunce DE, DiPietro LA, Kovacs EJ, Effects of acute ethanol exposure on the early inflammatory response after excisional injury, Alcohol Clin Exp Res 31(2) (2007) 317–23. [DOI] [PubMed] [Google Scholar]
  • [15].Parlet CP, Kavanaugh JS, Horswill AR, Schlueter AJ, Chronic ethanol feeding increases the severity of Staphylococcus aureus skin infections by altering local host defenses, Journal of Leukocyte Biology (2015). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [16].Ratna A, Mandrekar P, Alcohol and Cancer: Mechanisms and Therapies, Biomolecules 7(3) (2017). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [17].Travers JB, Weyerbacher J, Ocana JA, Borchers C, Rapp CM, Sahu RP, Acute Ethanol Exposure Augments Low-Dose UVB-Mediated Systemic Immunosuppression via Enhanced Production of Platelet-Activating Factor Receptor Agonists, J Invest Dermatol 139(7) (2019) 1619–1622. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [18].Harrison KA, Romer E, Weyerbacher J, Ocana JA, Sahu RP, Murphy RC, Kelly LE, Smith TA, Rapp CM, Borchers C, Cool DR, Li G, Simman R, Travers JB, Enhanced Platelet-Activating Factor Synthesis Facilitates Acute and Delayed Effects of Ethanol-Intoxicated Thermal Burn Injury, J Invest Dermatol 138(11) (2018) 2461–2469. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [19].Brand RM, Stottlemyer JM, Cline RA, Donahue C, Behari J, Falo LD Jr., Skin Immunization Obviates Alcohol-Related Immune Dysfunction, Biomolecules 5(4) (2015) 3009–28. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [20].Carson EJ, Pruett SB, Development and characterization of a binge drinking model in mice for evaluation of the immunological effects of ethanol, Alcoholism, clinical and experimental research 20(1) (1996) 132–8. [DOI] [PubMed] [Google Scholar]
  • [21].Meeran SM, Mantena SK, Katiyar SK, Prevention of ultraviolet radiation-induced immunosuppression by (−)-epigallocatechin-3-gallate in mice is mediated through interleukin 12-dependent DNA repair, Clin Cancer Res 12(7 Pt 1) (2006) 2272–80. [DOI] [PubMed] [Google Scholar]
  • [22].Schwarz A, Maeda A, Kernebeck K, van Steeg H, Beissert S, Schwarz T, Prevention of UV radiation–induced immunosuppression by IL-12 is dependent on DNA repair, The Journal of Experimental Medicine 201(2) (2005) 173–179. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [23].Mathers AR, Tckacheva OA, Janelsins BM, Shufesky WJ, Morelli AE, Larregina AT, In vivo signaling through the neurokinin 1 receptor favors transgene expression by Langerhans cells and promotes the generation of Th1- and Tc1-biased immune responses, J Immunol 178(11) (2007) 7006–17. [DOI] [PubMed] [Google Scholar]
  • [24].Brand RM, Epperly MW, Stottlemyer JM, Skoda EM, Gao X, Li S, Huq S, Wipf P, Kagan VE, Greenberger JS, Falo LD Jr., A Topical Mitochondria-Targeted Redox Cycling Nitroxide Mitigates Oxidative Stress Induced Skin Damage, Journal of Investigative Dermatology (2016). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [25].Alaluf S, Heath A, Carter N, Atkins D, Mahalingam H, Barrett K, Kolb R, Smit N, Variation in melanin content and composition in type V and VI photoexposed and photoprotected human skin: the dominant role of DHI, Pigment cell research / sponsored by the European Society for Pigment Cell Research and the International Pigment Cell Society 14(5) (2001) 337–47. [DOI] [PubMed] [Google Scholar]
  • [26].Starkenburg S, Munroe ME, Waltenbaugh C, Early alteration in leukocyte populations and Th1/Th2 function in ethanol-consuming mice, Alcohol Clin Exp Res 25(8) (2001) 1221–30. [PubMed] [Google Scholar]
  • [27].Brand RM, Jendrzejewski JL, Topical treatment with (−)-epigallocatechin-3-gallate and genistein after a single UV exposure can reduce skin damage, Journal of Dermatological Science 50(1) (2008) 69–72. [DOI] [PubMed] [Google Scholar]
  • [28].Scott TL, Christian PA, Kesler MV, Donohue KM, Shelton B, Wakamatsu K, Ito S, D’Orazio J, Pigment-independent cAMP-mediated epidermal thickening protects against cutaneous UV injury by keratinocyte proliferation, Experimental Dermatology 21(10) (2012) 771–777. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [29].Sreevidya CS, Fukunaga A, Khaskhely NM, Masaki T, Ono R, Nishigori C, Ullrich SE, Agents that Reverse UV-Induced Immune Suppression and Photocarcinogenesis Affect DNA Repair, J Invest Dermatol 130(5) (2010) 1428–1437. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [30].Kunisada M, Kumimoto H, Ishizaki K, Sakumi K, Nakabeppu Y, Nishigori C, Narrow-Band UVB Induces More Carcinogenic Skin Tumors than Broad-Band UVB through the Formation of Cyclobutane Pyrimidine Dimer, J Invest Dermatol 127(12) (2007) 2865–2871. [DOI] [PubMed] [Google Scholar]
  • [31].Gibbs NK, Norval M, Photoimmunosuppression: a brief overview, Photodermatology, Photoimmunology & Photomedicine 29(2) (2013) 57–64. [DOI] [PubMed] [Google Scholar]
  • [32].Vaid M, Singh T, Prasad R, Elmets CA, Xu H, Katiyar SK, Bioactive Grape Proanthocyanidins Enhance Immune Reactivity in UV-Irradiated Skin through Functional Activation of Dendritic Cells in Mice, Cancer Prev Res (Phila) 6(3) (2013) 242–252. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 33.[] Katiyar SK, Vaid M, van Steeg H, Meeran SM, Green Tea Polyphenols Prevent UV-Induced Immunosuppression by Rapid Repair of DNA Damage and Enhancement of Nucleotide Excision Repair Genes, Cancer Prev Res (Phila) 3(2) (2010) 179–189. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [34].Kripke ML, Reflections on the Field of Photoimmunology, J Invest Dermatol 133(1) (2013) 27–30. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [35].Ullrich SE, Byrne SN, The Immunologic Revolution: Photoimmunology, J Invest Dermatol 132(3) (2012) 896–905. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [36].Kaneko K, Smetana-Just U, Matsui M, Young AR, John S, Norval M, Walker SL, cis-Urocanic Acid Initiates Gene Transcription in Primary Human Keratinocytes, The Journal of Immunology 181(1) (2008) 217–224. [DOI] [PubMed] [Google Scholar]
  • [37].Damiani E, Ullrich SE, Understanding the connection between platelet-activating factor, a UV-induced lipid mediator of inflammation, immune suppression and skin cancer, Progress in Lipid Research 63 (2016) 14–27. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [38].Yang L, Latchoumycandane C, McMullen MR, Pratt BT, Zhang R, Papouchado BG, Nagy LE, Feldstein AE, McIntyre TM, Chronic Alcohol Exposure Increases Circulating Bioactive Oxidized Phospholipids, Journal of Biological Chemistry 285(29) (2010) 22211–22220. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [39].Travers JB, Platelet-Activating Factor as an Effector for Environmental Stressors, Handb Exp Pharmacol (2019). [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [40].Katiyar SK, Bergamo BM, Vyalil PK, Elmets CA, Green tea polyphenols: DNA photodamage and photoimmunology, J Photochem Photobiol B 65(2-3) (2001) 109–14. [DOI] [PubMed] [Google Scholar]
  • [41].Schwarz A, Schwarz T, UVR-Induced Regulatory T Cells Switch Antigen-Presenting Cells from a Stimulatory to a Regulatory Phenotype, J Invest Dermatol 130(7) (2010) 1914–1921. [DOI] [PubMed] [Google Scholar]
  • [42].Parlet CP, Schlueter AJ, Mechanisms by Which Chronic Ethanol Feeding Impairs the Migratory Capacity of Cutaneous Dendritic Cells, Alcoholism: Clinical and Experimental Research (2013) n/a-n/a. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [43].Parlet CP, Waldschmidt TJ, Schlueter AJ, Chronic Ethanol Feeding Induces Subset Loss and Hyporesponsiveness in Skin T Cells, Alcoholism: Clinical and Experimental Research 38(5) (2014) 1356–1364. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [44].Ness KJ, Fan J, Wilke WW, Coleman RA, Cook RT, Schlueter AJ, Chronic ethanol consumption decreases murine Langerhans cell numbers and delays migration of Langerhans cells as well as dermal dendritic cells, Alcoholism, clinical and experimental research 32(4) (2008) 657–68. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [45].Brand RM, Jendrzejewski JL, Henery EM, Charron AR, A single oral dose of ethanol can alter transdermal absorption of topically applied chemicals in rats, Toxicol Sci 92(2) (2006) 349–55. [DOI] [PubMed] [Google Scholar]
  • [46].Yang K, Fung TT, Nan H, An Epidemiological Review of Diet and Cutaneous Malignant Melanoma, Cancer Epidemiol Biomarkers Prev 27(10) (2018) 1115–1122. [DOI] [PubMed] [Google Scholar]
  • [47].Rivera A, Nan H, Li T, Qureshi A, Cho E, Alcohol Intake and Risk of Incident Melanoma: A Pooled Analysis of Three Prospective Studies in the United States, Cancer Epidemiol Biomarkers Prev 25(12) (2016) 1550–1558. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [48].Kubo J, Henderson M, Desai M, Wactawski-Wende J, Stefanick M, Tang J, Alcohol consumption and risk of melanoma and non-melanoma skin cancer in the Women’s Health Initiative, Cancer Causes & Control 25(1) (2014) 1–10. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [49].Yen H, Dhana A, Okhovat JP, Qureshi A, Keum N, Cho E, Alcohol intake and risk of nonmelanoma skin cancer: a systematic review and dose-response meta-analysis, Br J Dermatol 177(3) (2017) 696–707. [DOI] [PubMed] [Google Scholar]
  • [50].Siiskonen S, Han J, Li T, Cho E, Nijsten T, Qureshi A, Alcohol Intake is Associated with Increased Risk of Squamous Cell Carcinoma of the Skin: Three US Prospective Cohort Studies, Nutr Cancer 68(4) (2016) 545–53. [DOI] [PMC free article] [PubMed] [Google Scholar]

RESOURCES