1
|
Ma Y, Li Y, Yao Y, Huang T, Lan C, Li L. Mechanistic studies on protective effects of total flavonoids from Ilex latifolia Thunb. on UVB-radiated human keratinocyte cell line (HaCaT cells) based on network pharmacology and molecular docking technique. Photochem Photobiol 2024. [PMID: 38644599 DOI: 10.1111/php.13953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 03/28/2024] [Accepted: 03/29/2024] [Indexed: 04/23/2024]
Abstract
The aim of the present research is to investigate anti-UVB radiation activity of total flavonoids from Ilex latifolia Thunb. (namely large-leaved Kuding tea) on human keratinocyte cell line (HaCaT cells) based on network pharmacology and molecular docking technique. Network pharmacology was used to screen target genes of active ingredients from Ilex latifolia Thunb. associated with UVB irradiation. The possible signaling pathways were analyzed by KEGG enrichment and verified by cellular experiments. Molecular docking was used to assess the affinity between the active ingredients and the core targets. The prediction of network pharmacology and molecular docking was identified by series experiment in UVB-irradiated HaCaT cells. Network pharmacology results showed that the active ingredients of Ilex latifolia Thunb. for anti-UVB irradiation were mainly flavonoids, and the possible signaling pathways were involved in PI3K-AKT, apoptosis, MAPKs, NF-κB, and JAK-STAT3. Molecular docking indicated key binding activity between AKT1-Glycitein, STAT3-Formononetin, CASP3-Formononetin, TNF-Kaempferol, CASP3-Luteolin, and AKT1-Quercetin. The total flavonoid pretreatment (0.25-1.0 mg/mL) down-regulated the expression of IL-6, IL-1β, and TNF-α in the cells determined by ELISA. The expression of phosphor PI3K, phosphor AKT, phosphor JAK, phosphor STAT3, phosphor JNK, and phosphor p38 MAPKs and COX-2 proteins in cytosolic and NF-κB p65 protein in nucleus were down-regulated and determined by western blot. It also protected UVB-irradiated cells from apoptosis by reducing apoptosis rate and down-regulating active-caspase 3. In a word, the total flavonoid treatment protected HaCaT cells from UVB injuries effectively, and the potential mechanism involves PI3K-AKT, JAK-STAT3, MAPK, and NF-κB pathway by anti-inflammatory and apoptosis action in cells. The mechanism in vivo experiment needs to be further confirmed in future.
Collapse
Affiliation(s)
- Yunge Ma
- Pharmacy College, Henan University, Kaifeng, China
| | - Yingyan Li
- Pharmacy College, Henan University, Kaifeng, China
| | - Yike Yao
- Pharmacy College, Henan University, Kaifeng, China
| | - Tao Huang
- Medical School, Huanghe Science & Technology University, Zhengzhou, China
| | - Chong Lan
- Medical School, Huanghe Science & Technology University, Zhengzhou, China
- Zhengzhou Key Laboratory of Drug Screening and Activity Evaluation, Huanghe Science & Technology University, Zhengzhou, China
| | - Liyan Li
- Medical School, Huanghe Science & Technology University, Zhengzhou, China
- Zhengzhou Key Laboratory of Drug Screening and Activity Evaluation, Huanghe Science & Technology University, Zhengzhou, China
| |
Collapse
|
2
|
Ding C, Peng X, Yang J, Chen K, Liu X, Zhao Y, Zhang S, Sun S, Zhang J, Ding Q, Liu S, Liu W. Rg3-loaded P407/CS/HA hydrogel inhibits UVB-induced oxidative stress, inflammation and apoptosis in HaCaT cells. Biomed Pharmacother 2023; 165:115177. [PMID: 37467650 DOI: 10.1016/j.biopha.2023.115177] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 06/29/2023] [Accepted: 07/12/2023] [Indexed: 07/21/2023] Open
Abstract
UVB radiation can damage human skin, whereas Ginsenoside Rg3, the active ingredient in red ginseng that is processed from ginseng (Panax ginseng C.A. Meyer), could inhibit UVB induced cell damage through anti-oxidation. Meanwhile, P407/CS/HA hydrogel has significant biomedical applications as carriers of drugs. However, the beneficial effects of Rg3-loaded hydrogel (Rg3-Gel) on human HaCaT keratinocytes induced by UVB have rarely been reported. In our study, Rg3 was loaded into hydrogel and the effect of Rg3-Gel against UVB‑induced Hacat cells damages was determined by measuring its ability to alleviate UVB‑induced elevation of oxidative stress, pro-inflammatory and apoptotic response. We found that the treatment with Rg3-Gel inhibited the generation of intracellular ROS and MDA and upregulated the expression of antioxidant enzymes SOD and GSH-Px which were inhibited by UVB exposure. Increased levels of pro-inflammatory cytokines TNF‑α, COX‑2, iNOS and IL‑1β following UVB irradiation were suppressed by the introduction of Rg3-Gel. Additionally, the level of Bcl-2 was decreased and the expression of Bax and Caspase3 were enhanced by Rg3-Gel treatment. In conclusion, Rg3-Gel equipped with the synergistic effect of Rg3 and hydrogel has an effective inhibitory effect on UVB-induced oxidative stress, inflammatory and apoptosis.
Collapse
Affiliation(s)
- Chuanbo Ding
- Jilin Agricultural Science and Technology College, Jilin, China
| | - Xiaojuan Peng
- Jilin Agricultural University, Changchun, Jilin 130118, China
| | - Jiali Yang
- Jilin Agricultural University, Changchun, Jilin 130118, China
| | - Kecheng Chen
- Starsky Medical Research Center, Siping, Jilin 136001, China
| | - Xinglong Liu
- Jilin Agricultural Science and Technology College, Jilin, China
| | - Yingchun Zhao
- Jilin Agricultural University, Changchun, Jilin 130118, China
| | - Shuai Zhang
- Jilin Agricultural University, Changchun, Jilin 130118, China
| | - Shuwen Sun
- Jilin Agricultural University, Changchun, Jilin 130118, China
| | - Jinping Zhang
- Jilin Agricultural University, Changchun, Jilin 130118, China
| | - Qiteng Ding
- Jilin Agricultural University, Changchun, Jilin 130118, China
| | - Shuang Liu
- Goldenwell Biotech, Inc, 50 West Liberty Street, Suite 880, Reno, NV 89501, USA.
| | - Wencong Liu
- Jilin Agricultural University, Changchun, Jilin 130118, China.
| |
Collapse
|
3
|
Karen-Ng LP, Ahmad US, Gomes L, Hunter KD, Wan H, Hagi-Pavli E, Parkinson EK. Extracellular Prostaglandins E1 and E2 and Inflammatory Cytokines Are Regulated by the Senescence Program in Potentially Premalignant Oral Keratinocytes. Cancers (Basel) 2022; 14:cancers14112636. [PMID: 35681614 PMCID: PMC9179502 DOI: 10.3390/cancers14112636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Revised: 05/03/2022] [Accepted: 05/06/2022] [Indexed: 02/04/2023] Open
Abstract
Simple Summary The early treatment of oral cancer is a high priority, as improvements in this area could lead to greater cure rates and reduced disability due to extensive surgery. Oral cancer is very difficult to detect in over 70% of cases as it develops unseen until quite advanced, sometimes rapidly. It has become apparent that there are at least two types of epithelial cells (keratinocytes) found in oral tissue on the road to cancer (premalignant). One type secretes molecules called prostaglandins but the other does not and the former may stimulate the latter to progress to malignancy, either by stimulating their proliferation or encouraging the influx of blood vessels to feed them. Additionally, we have identified regulators of prostaglandin secretion in premalignant oral cells that could be targeted in future therapies, such as inducers of cellular senescence, drugs which kill senescent cells (senolytics), steroid metabolism, cyclo-oxygenase 2 (COX2) and p38 mitogen-activated protein kinase. Abstract Potentially pre-malignant oral lesions (PPOLs) are composed of keratinocytes that are either mortal (MPPOL) or immortal (IPPOL) in vitro. We report here that MPPOL, but not generally IPPOL, keratinocytes upregulate various extracellular tumor-promoting cytokines (interleukins 6 and 8) and prostaglandins E1 (ePGE1) and E2 (ePGE2) relative to normal oral keratinocytes (NOKs). ePGE upregulation in MPPOL was independent of PGE receptor status and was associated with some but not all markers of cellular senescence. Nevertheless, ePGE upregulation was dependent on the senescence program, cyclo-oxygenase 2 (COX2) and p38 mitogen-activated protein kinase and was partially regulated by hydrocortisone. Following senescence in the absence of p16INK4A, ePGEs accumulated in parallel with a subset of tumor promoting cytokine and metalloproteinase (MMP) transcripts, all of which were ablated by ectopic telomerase. Surprisingly, ataxia telangiectasia mutated (ATM) function was not required for ePGE upregulation and was increased in expression in IPPOL keratinocytes in line with its recently reported role in telomerase function. Only ePGE1 was dependent on p53 function, suggesting that ePGEs 1 and 2 are regulated differently in oral keratinocytes. We show here that ePGE2 stimulates IPPOL keratinocyte proliferation in vitro. Therefore, we propose that MPPOL keratinocytes promote the progression of IPPOL to oral SCC in a pre-cancerous field by supplying PGEs, interleukins and MMPs in a paracrine manner. Our results suggest that the therapeutic targeting of COX-2 might be enhanced by strategies that target keratinocyte senescence.
Collapse
Affiliation(s)
- Lee Peng Karen-Ng
- Center for Oral Immunobiology and Regenerative Medicine, Institute of Dentistry, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Turner Street, London E1 2AD, UK; (L.P.K.-N.); (U.S.A.); (L.G.); (H.W.); (E.H.-P.)
- Oral Cancer Research & Coordinating Center (OCRCC), Faculty of Dentistry, Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Usama Sharif Ahmad
- Center for Oral Immunobiology and Regenerative Medicine, Institute of Dentistry, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Turner Street, London E1 2AD, UK; (L.P.K.-N.); (U.S.A.); (L.G.); (H.W.); (E.H.-P.)
| | - Luis Gomes
- Center for Oral Immunobiology and Regenerative Medicine, Institute of Dentistry, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Turner Street, London E1 2AD, UK; (L.P.K.-N.); (U.S.A.); (L.G.); (H.W.); (E.H.-P.)
| | - Keith David Hunter
- Academic Unit of Oral and Maxillofacial Medicine and Pathology, School of Clinical Dentistry, University of Sheffield, Sheffield S10 2TA, UK;
- Liverpool Head and Neck Centre, Molecular and Clinical Medicine, University of Liverpool, Liverpool L1 8JX, UK
| | - Hong Wan
- Center for Oral Immunobiology and Regenerative Medicine, Institute of Dentistry, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Turner Street, London E1 2AD, UK; (L.P.K.-N.); (U.S.A.); (L.G.); (H.W.); (E.H.-P.)
| | - Eleni Hagi-Pavli
- Center for Oral Immunobiology and Regenerative Medicine, Institute of Dentistry, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Turner Street, London E1 2AD, UK; (L.P.K.-N.); (U.S.A.); (L.G.); (H.W.); (E.H.-P.)
| | - Eric Kenneth Parkinson
- Center for Oral Immunobiology and Regenerative Medicine, Institute of Dentistry, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Turner Street, London E1 2AD, UK; (L.P.K.-N.); (U.S.A.); (L.G.); (H.W.); (E.H.-P.)
- Correspondence: ; Tel.: +44-(0)-2078827185 or +44-(0)-7854046536
| |
Collapse
|
4
|
Zhang C, Lu Y, Ai Y, Xu X, Zhu S, Zhang B, Tang M, Zhang L, He T. Glabridin Liposome Ameliorating UVB-Induced Erythema and Lethery Skin by Suppressing Inflammatory Cytokine Production. J Microbiol Biotechnol 2021; 31:630-636. [PMID: 33526759 PMCID: PMC9706034 DOI: 10.4014/jmb.2011.11006] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 01/26/2021] [Accepted: 02/01/2021] [Indexed: 12/15/2022]
Abstract
Glabridin, a compound of the flavonoid, has shown outstanding skin-whitening and anti-aging properties, but its water insolubility limits its wide application. Therefore, glabridin liposome (GL) has been developed to improve its poor bioavailability, while there are few studies to evaluate its amelioration of UVB- induced photoaging. This study is performed to investigate the amelioration of GL against UVB- induced cutaneous photoaging. The prepared GL has a spheroidal morphology with an average diameter of 200 nm. The GL shows lower cytotoxicity than glabridin, but it has a more effective role in inhibition of melanin. Moreover, the application of GL can effectively relieve UV radiation induced erythema and leathery skin, associated with the down-regulated expression of inflammatory cytokines (TNF-α, IL-6 and IL-10). Taken together, these results demonstrate that GL has potentials as topical therapeutic agents against UVB radiation induced skin damage through inhibiting inflammation.
Collapse
Affiliation(s)
- Chijian Zhang
- Hua An Tang Biotech Group Co., Ltd., Guangzhou 510000, P.R. China
- Guangdong He Ji Biotech Co., Ltd., Guangzhou 510000, P.R. China
| | - Yongjie Lu
- Hua An Tang Biotech Group Co., Ltd., Guangzhou 510000, P.R. China
- Guangdong He Ji Biotech Co., Ltd., Guangzhou 510000, P.R. China
| | - Yong Ai
- Hua An Tang Biotech Group Co., Ltd., Guangzhou 510000, P.R. China
- Guangdong He Ji Biotech Co., Ltd., Guangzhou 510000, P.R. China
| | - Xian Xu
- Hua An Tang Biotech Group Co., Ltd., Guangzhou 510000, P.R. China
| | - Siyang Zhu
- Hua An Tang Biotech Group Co., Ltd., Guangzhou 510000, P.R. China
| | - Bing Zhang
- Guangdong He Ji Biotech Co., Ltd., Guangzhou 510000, P.R. China
| | - Minghui Tang
- Hua An Tang Biotech Group Co., Ltd., Guangzhou 510000, P.R. China
| | - Lanyue Zhang
- School of Biomedical and Pharmaceutical Sciences, Guangdong University of Technology, Guangzhou 510006, P.R. China
| | - Tinggang He
- Hua An Tang Biotech Group Co., Ltd., Guangzhou 510000, P.R. China
| |
Collapse
|
5
|
Chen F, Tang Y, Sun Y, Veeraraghavan VP, Mohan SK, Cui C. 6-shogaol, a active constiuents of ginger prevents UVB radiation mediated inflammation and oxidative stress through modulating NrF2 signaling in human epidermal keratinocytes (HaCaT cells). JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2019; 197:111518. [PMID: 31202076 DOI: 10.1016/j.jphotobiol.2019.111518] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 05/20/2019] [Accepted: 05/30/2019] [Indexed: 11/21/2022]
Abstract
Disclosure of ultraviolet (UV) radiation is the key feature from environment to cause redness of the skin, inflammation, photoaging and skin cancer. 6-Shogaol, a spicy compound secluded from ginger, which shows anti-inflammatory effects. Present study was demonstrated the role of 6-Shogaol on UVB induced oxidative stress and photoaging signaling in human epidermal keratinocytes (HaCaT cells). In this study, UVB-irratiation (180 mJ/cm2) significantly elevated the intracellular ROS levels, depletion of antioxidants resulted in apoptotic HaCaT cells. MAPKs signaling are concerned in oxidative stress; these signaling events are measured as differentiation. We found that 6-shogaol prevents over expression of MAPKs (ERK1, JNK1 & p38), in disclosure of UVB in HaCaT cells. Moreover, 6-shogaol infringed Bax and Bcl-2 in which 20 μg 6-shogaol influenced apoptosis in HaCaT cells by investigating augmented appearance of Bax and condensed appearance of Bcl-2 in contrast to control HaCaT cells. These results suggest that 6-shogaol could be a successful healing agent provides fortification against UVB-induced provocative and oxidative skin reimbursement.
Collapse
Affiliation(s)
- Feng Chen
- Dermatology Department, China-Japan Union Hospital of Jilin University, Changchun 130033, China
| | - Ying Tang
- Department of Respiratory Medicine, the First Hospital of Jilin University, Changchun 130021, China
| | - Yujia Sun
- Department of Operating Room, the Second Hospital of Jilin University, Changchun 130041, China
| | - Vishnu Priya Veeraraghavan
- Department of Biochemistry, Saveetha Dental College, Saveetha Institute of Medical and Technical Sciences,Saveetha University, Chennai 600 077, India
| | - Surapaneni Krishna Mohan
- Department of Medical Biochemistry, College of Applied Medical Sciences - Jubail (CAMSJ), Imam Abdulrahman Bin Faisal University, P.O.Box 4030, Al Ansar Rd, Deffi, Jubail Industrial City, Al Jubail 35816, Saudi Arabia
| | - Chuanxin Cui
- Dermatology Department, China-Japan Union Hospital of Jilin University, Changchun 130033, China.
| |
Collapse
|
6
|
Protein activation mapping of human sun-protected epidermis after an acute dose of erythemic solar simulated light. NPJ Precis Oncol 2017; 1. [PMID: 29167824 PMCID: PMC5695572 DOI: 10.1038/s41698-017-0037-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Ultraviolet radiation is an important etiologic factor in skin cancer and a better understanding of how solar stimulated light (SSL) affects signal transduction pathways in human skin which is needed in further understanding activated networks that could be targeted for skin cancer prevention. We utilized Reverse Phase Protein Microarray Analysis (RPPA), a powerful technology that allows for broad-scale and quantitative measurement of the activation/phosphorylation state of hundreds of key signaling proteins and protein pathways in sun-protected skin after an acute dose of two minimal erythema dose (MED) of SSL. RPPA analysis was used to map the altered cell signaling networks resulting from acute doses of solar simulated radiation (SSL). To that end, we exposed sun-protected skin in volunteers to acute doses of two MED of SSL and collected biopsies pre-SSL and post-SSL irradiation. Frozen biopsies were subjected to laser capture microdissection (LCM) and then assessed by RPPA. The activation/phosphorylation or total levels of 128 key signaling proteins and drug targets were selected for statistical analysis. Coordinate network-based analysis was performed on specific signaling pathways that included the PI3k/Akt/mTOR and Ras/Raf/MEK/ERK pathways. Overall, we found early and sustained activation of the PI3K-AKT-mTOR and MAPK pathways. Cell death and apoptosis-related proteins were activated at 5 and 24 h. Ultimately, expression profile patterns of phosphorylated proteins in the epidermal growth factor receptor(EGFR), AKT, mTOR, and other relevant pathways may be used to determine pharmacodynamic activity of new and selective topical chemoprevention agents administered in a test area exposed to SSL to determine drug-induced attenuation or reversal of skin carcinogenesis pathways. Skin exposure to ultraviolet radiation leads to the activation of proteins involved in carcinogenic pathways. Janine Einspahr and Clara Curiel-Lewandrowski of the Arizona Cancer Center and colleagues in the US exposed normally ultraviolet protected skin of 12 individuals to two times the dose of solar-simulated light needed to induce redness. Skin biopsies were taken before and after exposure and 128 proteins known to be involved in key cancer signaling pathways were examined using ‘reverse phase protein microarray analysis’. They found early and sustained activation of multiple signaling pathways, in addition to activation of cell death and apoptosis-related proteins. The study may serve as a model for investigating the pathways involved in chronic or ultraviolet-induced carcinogenesis, which may ultimately lead to the development of targeted therapies to attenuate or reverse skin cancer pathways.
Collapse
|
7
|
Sample A, Zhao B, Qiang L, He YY. Adaptor protein p62 promotes skin tumor growth and metastasis and is induced by UVA radiation. J Biol Chem 2017; 292:14786-14795. [PMID: 28724634 DOI: 10.1074/jbc.m117.786160] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 07/17/2017] [Indexed: 11/06/2022] Open
Abstract
Skin cancer is the most common cancer, and exposure to ultraviolet (UV) radiation, namely UVA and UVB, is the major risk factor for skin cancer development. UVA is significantly less effective in causing direct DNA damage than UVB, but UVA has been shown to increase skin cancer risk. The mechanism by which UVA contributes to skin cancer remains unclear. Here, using RNA-Seq, we show that UVA induces autophagy and lysosomal gene expression, including the autophagy receptor and substrate p62. We found that UVA activates transcription factor EB (TFEB), a known regulator of autophagy and lysosomal gene expression, which, in turn, induces p62 transcription. Next, we identified a novel relationship between p62 and cyclooxygenase-2 (COX-2), a prostaglandin synthase critical for skin cancer development. COX-2 expression was up-regulated by UVA-induced p62, suggesting that p62 plays a role in UVA-induced skin cancer. Moreover, we found that p62 stabilizes COX-2 protein through the p62 ubiquitin-associated domain and that p62 regulates prostaglandin E2 production in vitro In a syngeneic squamous cell carcinoma mouse model, p62 knockdown inhibited tumor growth and metastasis. Furthermore, p62-deficient tumors exhibited reduced immune cell infiltration and increased cell differentiation. Because prostaglandin E2 is known to promote pro-tumorigenic immune cell infiltration, increase proliferation, and inhibit keratinocyte differentiation in vivo, this work suggests that UVA-induced p62 acts through COX-2 to promote skin tumor growth and progression. These findings expand our understanding of UVA-induced skin tumorigenesis and tumor progression and suggest that targeting p62 can help prevent or treat UVA-associated skin cancer.
Collapse
Affiliation(s)
- Ashley Sample
- From the Department of Medicine, Section of Dermatology, and.,the Committee on Cancer Biology, University of Chicago, Chicago, Illinois 60637 and
| | - Baozhong Zhao
- From the Department of Medicine, Section of Dermatology, and
| | - Lei Qiang
- From the Department of Medicine, Section of Dermatology, and.,the School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing 210008, China
| | - Yu-Ying He
- From the Department of Medicine, Section of Dermatology, and .,the Committee on Cancer Biology, University of Chicago, Chicago, Illinois 60637 and
| |
Collapse
|
8
|
Sample A, He YY. Autophagy in UV Damage Response. Photochem Photobiol 2017; 93:943-955. [PMID: 27935061 PMCID: PMC5466513 DOI: 10.1111/php.12691] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 10/22/2016] [Indexed: 12/14/2022]
Abstract
UV radiation exposure from sunlight and artificial tanning beds is the major risk factor for the development of skin cancer and skin photoaging. UV-induced skin damage can trigger a cascade of DNA damage response signaling pathways, including cell cycle arrest, DNA repair and, if damage is irreparable, apoptosis. Compensatory proliferation replaces the apoptotic cells to maintain skin barrier integrity. Disruption of these processes can be exploited to promote carcinogenesis by allowing the survival and proliferation of damaged cells. UV radiation also induces autophagy, a catabolic process that clears unwanted or damaged proteins, lipids and organelles. The mechanisms by which autophagy is activated following UV exposure, and the functions of autophagy in UV response, are only now being clarified. Here, we summarize the current understanding of the mechanisms governing autophagy regulation by UV, the roles of autophagy in regulating cellular response to UV-induced photodamage and the implications of autophagy modulation in the treatment and prevention of photoaging and skin cancer.
Collapse
Affiliation(s)
- Ashley Sample
- Department of Medicine, Section of Dermatology, University of Chicago, Chicago, IL
- Committee on Cancer Biology, University of Chicago, Chicago, IL
| | - Yu-Ying He
- Department of Medicine, Section of Dermatology, University of Chicago, Chicago, IL
- Committee on Cancer Biology, University of Chicago, Chicago, IL
| |
Collapse
|
9
|
Gęgotek A, Bielawska K, Biernacki M, Dobrzyńska I, Skrzydlewska E. Time-dependent effect of rutin on skin fibroblasts membrane disruption following UV radiation. Redox Biol 2017; 12:733-744. [PMID: 28412651 PMCID: PMC5393167 DOI: 10.1016/j.redox.2017.04.014] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 04/06/2017] [Accepted: 04/08/2017] [Indexed: 02/07/2023] Open
Abstract
Chronic exposure of the skin to solar UV radiation induces a number of biological alterations, including a redox imbalance; therefore, there is an urgent need for skin cells protective compounds. The aim of this study was to determine the effects of natural, previously extensively examined, polyphenol with antioxidant properties - rutin, on UV-induced skin fibroblasts membrane disruption. Accordingly, fibroblasts exposed to UVA and UVB irradiation were incubated with rutin (12h before and/or up to 24h after irradiation), and the structural and metabolic changes were examined. Rutin penetration through the fibroblast phospholipid bilayer was aided by UVA-induced bilitranslocase activity 2-4h after irradiation, while UVB irradiation led to enhanced phospholipid peroxidation and higher membrane permeability to facilitate the interaction of rutin with phospholipids. Lipidomic analysis revealed that 4h of rutin treatment also partially prevented UVA/B-induced increase in phosphatidylethanolamine and phosphatidylcholine level, as well as their membrane localization, which resulted in an enhanced zeta potential in the cells and liposomes. Moreover, rutin 2h following irradiation, in a various degree, prevented the increased in phospholipase A2 activity and ROS generation, and partially protected against the reduction of arachidonic and linoleic acids level and the lipid peroxidation product 4-hydroxynonenal level increase. Rutin effectively prevented against decrease in glutathione peroxidase, glutathione and vitamins E and C activities/levels, particularly 2h following UVA irradiation. In conclusion, highest skin fibroblasts membrane level of rutin occurred in 2-4h following UVA/B-radiation results in its strongest effect on biomembrane structure and functions and cellular antioxidant system irrespective of the radiation type.
Collapse
Affiliation(s)
- Agnieszka Gęgotek
- Department of Inorganic and Analytical Chemistry, Medical University of Bialystok, Bialystok, Poland
| | - Katarzyna Bielawska
- Department of Inorganic and Analytical Chemistry, Medical University of Bialystok, Bialystok, Poland
| | - Michał Biernacki
- Department of Inorganic and Analytical Chemistry, Medical University of Bialystok, Bialystok, Poland
| | - Izabela Dobrzyńska
- Department of Electrochemistry, University of Bialystok, Bialystok, Poland
| | - Elżbieta Skrzydlewska
- Department of Inorganic and Analytical Chemistry, Medical University of Bialystok, Bialystok, Poland.
| |
Collapse
|
10
|
Bou-Dargham MJ, Khamis ZI, Cognetta AB, Sang QXA. The Role of Interleukin-1 in Inflammatory and Malignant Human Skin Diseases and the Rationale for Targeting Interleukin-1 Alpha. Med Res Rev 2016; 37:180-216. [PMID: 27604144 DOI: 10.1002/med.21406] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Revised: 07/19/2016] [Accepted: 07/23/2016] [Indexed: 12/11/2022]
Abstract
Inflammation plays a major role in the induction and progression of several skin diseases. Overexpression of the major epidermal proinflammatory cytokines interleukin (IL) 1 alpha (IL-1α) and 1 beta (IL-1β) is positively correlated with symptom exacerbation and disease progression in psoriasis, atopic dermatitis, neutrophilic dermatoses, skin phototoxicity, and skin cancer. IL-1β and the interleukin-1 receptor I (IL-1RI) have been used as a therapeutic target for some autoinflammatory skin diseases; yet, their system-wide effects limit their clinical usage. Based on the local effects of extracellular IL-1α and its precursor, pro-IL-1α, we hypothesize that this isoform is a promising drug target for the treatment and prevention of many skin diseases. This review provides an overview on IL-1α and IL-β functions, and their contribution to inflammatory and malignant skin diseases. We also discuss the current treatment regimens, and ongoing clinical trials, demonstrating the potential of targeting IL-1α, and not IL-1β, as a more effective strategy to prevent or treat the onset and progression of various skin diseases.
Collapse
Affiliation(s)
- Mayassa J Bou-Dargham
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, 32306.,Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32306
| | - Zahraa I Khamis
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, 32306.,Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32306.,Department of Chemistry and Biochemistry, Lebanese University, Faculty of Sciences, Hadath-Beirut, Lebanon
| | - Armand B Cognetta
- Dermatology Associates of Tallahassee and Division of Dermatology, Florida State University College of Medicine, Tallahassee, FL, 32308
| | - Qing-Xiang Amy Sang
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, 32306.,Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32306
| |
Collapse
|
11
|
Bermudez Y, Stratton SP, Curiel-Lewandrowski C, Warneke J, Hu C, Bowden GT, Dickinson SE, Dong Z, Bode AM, Saboda K, Brooks CA, Petricoin EF, Hurst CA, Alberts DS, Einspahr JG. Activation of the PI3K/Akt/mTOR and MAPK Signaling Pathways in Response to Acute Solar-Simulated Light Exposure of Human Skin. Cancer Prev Res (Phila) 2015; 8:720-8. [PMID: 26031292 DOI: 10.1158/1940-6207.capr-14-0407] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 05/06/2015] [Indexed: 12/14/2022]
Abstract
The incidence of skin cancer is higher than all other cancers and continues to increase, with an average annual cost over $8 billion in the United States. As a result, identifying molecular pathway alterations that occur with UV exposure to strategize more effective preventive and therapeutic approaches is essential. To that end, we evaluated phosphorylation of proteins within the PI3K/Akt and MAPK pathways by immunohistochemistry in sun-protected skin after acute doses of physiologically relevant solar-simulated ultraviolet light (SSL) in 24 volunteers. Biopsies were performed at baseline, 5 minutes, 1, 5, and 24 hours after SSL irradiation. Within the PI3K/Akt pathway, we found activation of Akt (serine 473) to be significantly increased at 5 hours while mTOR (serine 2448) was strongly activated early and was sustained over 24 hours after SSL. Downstream, we observed a marked and sustained increase in phospho-S6 (serine 235/S236), whereas phospho-4E-BP1 (threonines 37/46) was increased only at 24 hours. Within the MAPK pathway, SSL-induced expression of phospho-p38 (threonine 180/tyrosine 182) peaked at 1 to 5 hours. ERK 1/2 was observed to be immediate and sustained after SSL irradiation. Phosphorylation of histone H3 (serine 10), a core structural protein of the nucleosome, peaked at 5 hours after SSL irradiation. The expression of both p53 and COX-2 was increased at 5 hours and was maximal at 24 hours after SSL irradiation. Apoptosis was significantly increased at 24 hours as expected and indicative of a sunburn-type response to SSL. Understanding the timing of key protein expression changes in response to SSL will aid in development of mechanistic-based approaches for the prevention and control of skin cancers.
Collapse
Affiliation(s)
- Yira Bermudez
- College of Medicine, University of Arizona, Tucson, Arizona. The University of Arizona Cancer Center, Tucson, Arizona
| | - Steven P Stratton
- College of Medicine, University of Arizona, Tucson, Arizona. The University of Arizona Cancer Center, Tucson, Arizona
| | - Clara Curiel-Lewandrowski
- College of Medicine, University of Arizona, Tucson, Arizona. The University of Arizona Cancer Center, Tucson, Arizona
| | - James Warneke
- College of Medicine, University of Arizona, Tucson, Arizona. The University of Arizona Cancer Center, Tucson, Arizona. Department of Surgery, University of Arizona, Tucson, Arizona
| | - Chengcheng Hu
- The University of Arizona Cancer Center, Tucson, Arizona
| | | | | | - Zigang Dong
- The Hormel Institute, University of Minnesota, Austin, Minnesota
| | - Ann M Bode
- The Hormel Institute, University of Minnesota, Austin, Minnesota
| | | | | | | | - Craig A Hurst
- College of Medicine, University of Arizona, Tucson, Arizona. Department of Surgery, University of Arizona, Tucson, Arizona
| | - David S Alberts
- College of Medicine, University of Arizona, Tucson, Arizona. The University of Arizona Cancer Center, Tucson, Arizona
| | - Janine G Einspahr
- College of Medicine, University of Arizona, Tucson, Arizona. The University of Arizona Cancer Center, Tucson, Arizona.
| |
Collapse
|
12
|
|
13
|
Vostalova J, Rajnochova Svobodova A, Galandakova A, Sianska J, Dolezal D, Ulrichova J. Differential modulation of inflammatory markers in plasma and skin after single exposures to UVA or UVB radiation in vivo. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 2013; 157:137-45. [PMID: 23733148 DOI: 10.5507/bp.2013.036] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Accepted: 04/30/2013] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Solar light generates inflammatory responses in exposed skin. These effects are generally attributed to UVB light. However, skin is expose d to a huge quantum of UVA photons as UVA is a predominant part of sunlight and the radiation used in tanning beds. We examined the effects of a single exposure to UVA and UVB wavebands on cytokine levels in skin and plasma, myeloperoxidase (MPO) activity, expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) in skin. METHODS Hairless mice were irradiated with either UVA (10 or 20 J/cm²) or UVB (200 or 800 mJ/cm²). The effects were assessed after 4/24 h. Plasma cytokine levels were evaluated using a Bio-Plex cytokine assay. Cytokine, iNOS and COX-2 levels in skin were determined by Western blot. Skin MPO activity was monitored spectrophotometrically. RESULTS UVB induced up-regulation of interleukin-1β (IL-1β) and interleukin-6 (IL-6) and decrease in interleukin-10 (IL-10) mainly after 4 h. In contrast, UVA caused increase in levels of tumor necrosis factor-alpha (TNF-α) and IL-6 after 4 h and up-regulated IL-10 and interleukin-12 (IL-12) after 24 h. The increase in MPO activity from infiltrated leucocytes was observed only in UVB irradiated animals. iNOS was up-regulated 4 h after UVA and UVB treatment. No significant effect on COX-2 expression was detected. CONCLUSIONS UVA and UVB light affected several inflammatory markers. For individual waveband, changes in plasma parameters did not correlate with those in skin. Thus evaluation of plasma samples cannot simply be replaced by determination in skin specimens and vice versa.
Collapse
Affiliation(s)
- Jitka Vostalova
- Department of Medical Chemistry and Biochemistry, Faculty of Medicine and Dentistry, Palacky University Olomouc, Czech Republic
| | | | | | | | | | | |
Collapse
|
14
|
Lee C, Park GH, Ahn EM, Kim BA, Park CI, Jang JH. Protective effect of Codium fragile against UVB-induced pro-inflammatory and oxidative damages in HaCaT cells and BALB/c mice. Fitoterapia 2013; 86:54-63. [DOI: 10.1016/j.fitote.2013.01.020] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2012] [Revised: 01/15/2013] [Accepted: 01/23/2013] [Indexed: 01/19/2023]
|
15
|
Ghezali L, Leger DY, Limami Y, Cook-Moreau J, Beneytout JL, Liagre B. Cyclopamine and jervine induce COX-2 overexpression in human erythroleukemia cells but only cyclopamine has a pro-apoptotic effect. Exp Cell Res 2013; 319:1043-53. [PMID: 23357584 DOI: 10.1016/j.yexcr.2013.01.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Revised: 01/18/2013] [Accepted: 01/21/2013] [Indexed: 11/17/2022]
Abstract
Erythroleukemia is generally associated with a very poor response and survival to current available therapeutic agents. Cyclooxygenase-2 (COX-2) has been described to play a crucial role in the proliferation and differentiation of leukemia cells, this enzyme seems to play an important role in chemoresistance in different cancer types. Previously, we demonstrated that diosgenin, a plant steroid, induced apoptosis in HEL cells with concomitant COX-2 overexpression. In this study, we investigated the antiproliferative and apoptotic effects of cyclopamine and jervine, two steroidal alkaloids with similar structures, on HEL and TF1a human erythroleukemia cell lines and, for the first time, their effect on COX-2 expression. Cyclopamine, but not jervine, inhibited cell proliferation and induced apoptosis in these cells. Both compounds induced COX-2 overexpression which was responsible for apoptosis resistance. In jervine-treated cells, COX-2 overexpression was NF-κB dependent. Inhibition of NF-κB reduced COX-2 overexpression and induced apoptosis. In addition, cyclopamine induced apoptosis and COX-2 overexpression via PKC activation. Inhibition of the PKC pathway reduced both apoptosis and COX-2 overexpression in both cell lines. Furthermore, we demonstrated that the p38/COX-2 pathway was involved in resistance to cyclopamine-induced apoptosis since p38 inhibition reduced COX-2 overexpression and increased apoptosis in both cell lines.
Collapse
Affiliation(s)
- Lamia Ghezali
- Université de Limoges, FR 3503 GEIST, EA 1069 "Laboratoire de Chimie des Substances Naturelles", GDR CNRS 3049, Faculté de Pharmacie, Laboratoire de Biochimie et Biologie Moléculaire, 2 rue du Docteur Marcland, 87025 Limoges Cedex, France
| | | | | | | | | | | |
Collapse
|
16
|
He Z, Cui P, Ye C, Ma WY, Bode A, Dong Z. Analysis of the role of p38 MAP kinase in epidermal growth factor-induced JB6 Cl41 cell transformation by cDNA array. Gene 2012; 497:71-8. [PMID: 22301268 DOI: 10.1016/j.gene.2011.12.054] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2011] [Revised: 11/28/2011] [Accepted: 12/22/2011] [Indexed: 12/01/2022]
Abstract
To further explore the mechanism of p38 MAP kinase in regulation of JB6 Cl41 cell transformation. cDNA array was employed to scan the differential expression genes between DN-p38 cells and CMV-neo JB6 Cl41 cells after EGF stimuli. We found that up-expression genes including oncogenes and tumor suppressor genes, p53-associated protein, transcription repressors, apoptosis-associated genes, and growth arrest and DNA damage-inducible protein 153 were detected in DN-p38 cells, but low expression in CMV-neo JB6 Cl41 cells after EGF treatment. Meanwhile, some proto-oncogenes, such as c-Myc, and signal transducer and activator of transcription 1 (STAT1) were lowly expressed in EGF-stimulated DN-p38 cells, but had relatively high expression level in CMV-neo JB6 Cl41 cells under the same stimuli. Four of the differential expression genes were further confirmed by quantitative RT-PCR analysis. Our results indicate that p38 MAP kinase is involved in EGF-induced JB6 Cl41 cell transformation through effecting on more genes expression levels including transcription factors, proto-oncogene, apoptosis-related genes and growth arrest genes.
Collapse
Affiliation(s)
- Zhiwei He
- China-America Cancer Research Institute, Guangdong Medical College, Dongguan 523808, PR China.
| | | | | | | | | | | |
Collapse
|
17
|
Tyrrell RM. Modulation of gene expression by the oxidative stress generated in human skin cells by UVA radiation and the restoration of redox homeostasis. Photochem Photobiol Sci 2012; 11:135-47. [DOI: 10.1039/c1pp05222e] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
|
18
|
Cyclooxygenase-dependent signaling is causally linked to non-melanoma skin carcinogenesis: pharmacological, genetic, and clinical evidence. Cancer Metastasis Rev 2011; 30:343-61. [DOI: 10.1007/s10555-011-9306-z] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
19
|
Zhang J, Bowden GT. Activation of p38 MAP kinase and JNK pathways by UVA irradiation. Photochem Photobiol Sci 2011; 11:54-61. [PMID: 21858326 DOI: 10.1039/c1pp05133d] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
There are more than two million new cases of non-melanoma skin cancers (NMSCs) diagnosed each year in the United States of America. The clear etiological factor is chronic exposure to solar radiation from the sun. The wavelengths of solar light that reach the earth's surface include UVB (280-320 nm), which accounts for 1-10%, and UVA (320-400 nm), which accounts for 90-99% of the radiation. While most published research has focused on the effects of UVB, little is known concerning UVA-mediated signal transduction pathways, and their role in skin tumor promotion and progression, giving rise to squamous cell carcinomas (SCCs). Here, we focus on UVA-mediated activation of p38 MAP kinase and c-Jun N-terminal kinase (JNK), and their roles in activator protein-1 (AP-1) mediated transcription, cyclooxygenase-2 (COX-2) and Bcl-XL expression. Since p38 MAP kinase and JNK play major roles in the expression of UVA-induced AP-1, COX-2 and Bcl-XL, pharmacological inhibitors of these kinases may be useful in the chemoprevention of SCC skin cancer.
Collapse
Affiliation(s)
- Jack Zhang
- Department of Medical Pharmacology, University of Arizona, Tucson, Arizona, USA
| | | |
Collapse
|
20
|
Wu NL, Fang JY, Chen M, Wu CJ, Huang CC, Hung CF. Chrysin protects epidermal keratinocytes from UVA- and UVB-induced damage. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2011; 59:8391-8400. [PMID: 21699266 DOI: 10.1021/jf200931t] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Chrysin (5,7-dihydroxyflavone), a natural flavonoid occurring in various plants and foods such as propolis and honey, reportedly opposes inflammation and carcinogenesis, but has rarely been applied in skin care. This study, therefore, aimed to explore the roles of chrysin in protection against UV-induced damage in HaCaT keratinocytes. Results showed that chrysin can attenuate apoptosis, reactive oxygen species (ROS) production, and cyclooxygenase 2 (COX-2) expression induced by UVB and UVA. Chrysin predominantly reversed the down-regulation of aquaporin 3 (AQP-3) by UVB. It predominantly reversed JNK activation and also mildly inhibited p38 activation triggered by UVA and UVB. Animal studies revealed that chrysin's topical application demonstrated efficient percutaneous absorption and no skin irritation. Overall, results demonstrated significant benefits of chrysin on the protection of keratinocytes against UVA- and UVB-induced injuries and suggested its potential use in skin photoprotection.
Collapse
Affiliation(s)
- Nan-Lin Wu
- Department of Dermatology, Mackay Memorial Hospital, Hsinchu, Taiwan
| | | | | | | | | | | |
Collapse
|
21
|
Limami Y, Pinon A, Leger DY, Mousseau Y, Cook-Moreau J, Beneytout JL, Delage C, Liagre B, Simon A. HT-29 colorectal cancer cells undergoing apoptosis overexpress COX-2 to delay ursolic acid-induced cell death. Biochimie 2011; 93:749-57. [PMID: 21251952 DOI: 10.1016/j.biochi.2011.01.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2010] [Accepted: 01/06/2011] [Indexed: 01/07/2023]
Abstract
Colorectal cancer is one of the most common cancer types and the third leading cause of cancer-related death in the western world. Generally, colorectal cancers are resistant to anticancer drugs. Several lines of evidence support a critical role for cyclooxygenase-2 (COX-2) during colorectal tumorigenesis and its role in chemoresistance. In this study, we focused our interest on the role played by COX-2 in apoptosis induced in HT-29 human colorectal cancer cells by ursolic acid (UA), a triterpenoid found in a large variety of plants. We showed that UA-induced apoptosis and that COX-2 was overexpressed only in apoptotic cells. We demonstrated that this overexpression was mediated by the p38 MAP kinase pathway as inhibiting its activation using a p38-specific inhibitor, SB 203580, abrogated COX-2 expression. Inhibiting COX-2 expression either by using a p38-specific inhibitor or COX-2-specific siRNA increased apoptosis. These results demonstrated that COX-2 was involved in a resistance mechanism to UA-induced apoptosis in HT-29 cells. Cells undergoing apoptosis were able to trigger a resistance mechanism by overexpressing a protein such as COX-2 to delay their death. Furthermore, we demonstrated that this resistance mechanism was independent of PGE(2) production as the addition of the specific COX-2 activity inhibitor, NS-398, did not affect apoptosis in UA-treated cells.
Collapse
Affiliation(s)
- Youness Limami
- Université de Limoges, Institut GEIST, EA 4021, Biomolécules et thérapies anti-tumorales, Faculté de Pharmacie, Limoges, France
| | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Rouzaud F, Oulmouden A, Kos L. The untranslated side of hair and skin mammalian pigmentation: Beyond coding sequences. IUBMB Life 2010; 62:340-6. [PMID: 20222017 DOI: 10.1002/iub.318] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
For several decades, tremendous advances in studying skin and hair pigmentation of mammals have been made using Mendelian genetics principles. A number of loci and their associated traits have been extensively examined, crossings performed, and phenotypes well documented. Continuously improving PCR techniques allowed the molecular cloning and sequencing of the first pigmentation genes at the end of the 20th century, a period followed by an intense effort to detect and describe polymorphisms in the coding regions and correlate allelic combinations with the observed melanogenic phenotypes. However, a number of phenotypes and biological events could not be elucidated solely by analysis of the coding regions of genes. Messenger RNA isolation, characterization and quantification techniques allowed groups to move ahead and investigate molecular mechanisms whose secrets lay within the noncoding regions of pigmentation genes transcripts such as MC1R, ASIP, or Mitf. The untranslated elements contain specific nucleotidic sequences and structures that dramatically influence the mRNA half-life and processing thus impacting protein translation and melanin production. As we are progressively uncovering the complex processes regulating melanocyte biology, unraveling complete mRNA structures and understanding mechanisms beyond coding regions has become critical.
Collapse
Affiliation(s)
- Francois Rouzaud
- Department of Biological Sciences, Florida International University, Miami, FL, USA
| | | | | |
Collapse
|
23
|
Seo M, Juhnn YS. Gq protein mediates UVB-induced cyclooxygenase-2 expression by stimulating HB-EGF secretion from HaCaT human keratinocytes. Biochem Biophys Res Commun 2010; 393:190-5. [PMID: 20117092 DOI: 10.1016/j.bbrc.2010.01.085] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2010] [Accepted: 01/20/2010] [Indexed: 12/19/2022]
Abstract
Ultraviolet (UV) radiation induces cyclooxygenase-2 expression to produce cellular responses including aging and carcinogenesis in skin. We hypothesised that heterotrimeric G proteins mediate UV-induced COX-2 expression by stimulating secretion of soluble HB-EGF (sHB-EGF). In this study, we aimed to elucidate the role and underlying mechanism of the alpha subunit of Gq protein (Galphaq) in UVB-induced HB-EGF secretion and COX-2 induction. We found that expression of constitutively active Galphaq (GalphaqQL) augmented UVB-induced HB-EGF secretion, which was abolished by knockdown of Galphaq with shRNA in HaCaT human keratinocytes. Galphaq was found to mediate the UVB-induced HB-EGF secretion by sequential activation of phospholipase C (PLC), protein kinase Cdelta (PKCdelta), and matrix metaloprotease-2 (MMP-2). Moreover, GalphaqQL mediated UVB-induced COX-2 expression in an HB-EGF-, EGFR-, and p38-dependent manner. From these results, we concluded that Galphaq mediates UV-induced COX-2 expression through activation of EGFR by HB-EGF, of which ectodomain shedding was stimulated through sequential activation of PLC, PKCdelta and MMP-2 in HaCaT cells.
Collapse
Affiliation(s)
- MiRan Seo
- Department of Biochemistry and Molecular Biology and Cancer Research Institute, Seoul National University College of Medicine, Republic of Korea
| | | |
Collapse
|
24
|
Fernau NS, Fugmann D, Leyendecker M, Reimann K, Grether-Beck S, Galban S, Ale-Agha N, Krutmann J, Klotz LO. Role of HuR and p38MAPK in ultraviolet B-induced post-transcriptional regulation of COX-2 expression in the human keratinocyte cell line HaCaT. J Biol Chem 2009; 285:3896-3904. [PMID: 19917608 DOI: 10.1074/jbc.m109.081430] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
COX-2 (cyclooxygenase-2) is a pivotal player in inflammatory processes, and ultraviolet radiation is a known stimulus for COX-2 expression in skin cells. Here, an induction of COX-2 expression in HaCaT human keratinocytes was observed only upon exposure of cells to UVB (280-320 nm) but not to UVA radiation (320-400 nm), as demonstrated by reverse transcription-PCR and Western blotting. Prostaglandin E(2) levels were elevated in cell culture supernatants of HaCaT cells exposed to UVB. COX-2 mRNA stability was dramatically increased by UVB irradiation. Both the stabilization of COX-2 mRNA and the enhancement of COX-2 steady-state mRNA and protein levels caused by UVB were prevented both by inhibition and small interfering RNA-induced depletion of p38(MAPK), a kinase strongly activated upon exposure to UVB, suggesting p38(MAPK)-dependent mRNA stabilization as a mechanism of UVB-induced COX-2 expression. A dramatic decrease in COX-2 expression induced by UVB was elicited by small interfering RNA-based depletion of a stress-responsive mRNA stabilizing protein regulated by p38(MAPK), i.e. HuR; UVB-induced elevation of COX-2 mRNA and protein levels coincided with an accumulation of HuR in the cytoplasm and was attenuated in cells depleted of HuR. Moreover, UVB-induced generation of prostaglandin E(2) by HaCaT cells was blunted by HuR depletion, suggesting that stress kinases (such as p38(MAPK)) as well as HuR are excellent targets for approaches aiming at interfering with induction of COX-2 expression by UVB.
Collapse
Affiliation(s)
- Niklas S Fernau
- From the Leibniz-Institut für Umweltmedizinische Forschung, D-40225 Düsseldorf, Germany
| | - Dominik Fugmann
- From the Leibniz-Institut für Umweltmedizinische Forschung, D-40225 Düsseldorf, Germany
| | - Martin Leyendecker
- From the Leibniz-Institut für Umweltmedizinische Forschung, D-40225 Düsseldorf, Germany
| | - Kerstin Reimann
- From the Leibniz-Institut für Umweltmedizinische Forschung, D-40225 Düsseldorf, Germany
| | - Susanne Grether-Beck
- From the Leibniz-Institut für Umweltmedizinische Forschung, D-40225 Düsseldorf, Germany
| | - Stefanie Galban
- From the Leibniz-Institut für Umweltmedizinische Forschung, D-40225 Düsseldorf, Germany
| | - Niloofar Ale-Agha
- From the Leibniz-Institut für Umweltmedizinische Forschung, D-40225 Düsseldorf, Germany
| | - Jean Krutmann
- From the Leibniz-Institut für Umweltmedizinische Forschung, D-40225 Düsseldorf, Germany
| | - Lars-Oliver Klotz
- From the Leibniz-Institut für Umweltmedizinische Forschung, D-40225 Düsseldorf, Germany.
| |
Collapse
|
25
|
Ridley AJ, Whiteside JR, McMillan TJ, Allinson SL. Cellular and sub-cellular responses to UVA in relation to carcinogenesis. Int J Radiat Biol 2009; 85:177-95. [PMID: 19296341 DOI: 10.1080/09553000902740150] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
PURPOSE UVA radiation (315-400 nm) contributes to skin aging and carcinogenesis. The aim of this review is to consider the mechanisms that underlie UVA-induced cellular damage, how this damage may be prevented or repaired and the signal transduction processes that are elicited in response to it. RESULTS Exposure to ultraviolet (UV) light is well-established as the causative factor in skin cancer. Until recently, most work on the mechanisms that underlie skin carcinogenesis focused on shorter wavelength UVB radiation (280-315 nm), however in recent years there has been increased interest in the contribution made by UVA. UVA is able to cause a range of damage to cellular biomolecules including lipid peroxidation, oxidized protein and DNA damage, such as 8-oxoguanine and cyclobutane pyrimidine dimers. Such damage is strongly implicated in both cell death and malignant transformation and cells have a number of mechanisms in place to mitigate the effects of UVA exposure, including antioxidants, DNA repair, and stress signalling pathways. CONCLUSIONS The past decade has seen a surge of interest in the biological effects of UVA exposure as its significance to the process of photo-carcinogenesis has become increasingly evident. However, unpicking the unique complexity of the cellular response to UVA, which is only now becoming apparent, will be a major challenge for the field of photobiology in the 21st century.
Collapse
Affiliation(s)
- Andrew J Ridley
- Division of Biomedical and Life Sciences, School of Health and Medicine, Lancaster University, UK.
| | | | | | | |
Collapse
|
26
|
The role of translational regulation in ultraviolet C light-induced cyclooxygenase-2 expression. Life Sci 2009; 85:70-6. [PMID: 19422838 DOI: 10.1016/j.lfs.2009.04.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2009] [Revised: 04/15/2009] [Accepted: 04/28/2009] [Indexed: 12/24/2022]
Abstract
AIMS The role of ultraviolet C light (UVC)-induced phosphorylation of the eukaryotic initiation factor 2 (eIF2) in the regulation of cyclooxygenase-2 (COX-2) expression at both transcriptional and translational levels is investigated. MAIN METHODS Western analysis was used to determine COX expressions. Immunoprecipitation after [(35)S]-Met/Cys metabolic labeling was used to determine the rate for COX-2 synthesis and turnover. Quantitative real-time PCR was used to determine COX-2 mRNA levels. Ingenuity Pathways Analysis 6 was used for mapping COX-2 activation network. KEY FINDINGS UVC induces COX-2 expression in wild-type mouse embryo fibroblasts (MEF(S/S)) and that the inducibility is reduced in MEF(A/A) cells in which the phosphorylation site, Ser-51 in the eIF2alpha, is replaced with a nonphosphorylatable Ala (S51A). UVC-induced transcription of COX-2 is delayed in MEF(A/A) cells, which correlates with NF-kappaB activation as previously reported (Wu, S, Tan, M, Hu, Y, Wang, JL, Scheuner, D, Kaufman, RJ, Ultraviolet light activates NFkappaB through translational inhibition of IkappaBalpha synthesis. The Journal of Biological Chemistry, 279, 34898-34902, 2004). The translational efficiency of COX-2 is higher in MEF(A/A) cells than in MEF(S/S) cells at 4 h, but not at 24 h post-UVC. The translation efficiency is correlated to the ratio of activated COX-2 binding protein HuR/TIAR. In addition, the newly synthesized COX-2 protein is more stable in MEF(A/A) cells than in MEF(S/S) cells. The results demonstrated a complex and dynamic regulation of COX-2 expression. SIGNIFICANCE UVC induces a prolonged expression of COX-2. While transcriptional regulation of COX-2 expression is intensively studied, the role of translational regulation of COX-2 synthesis upon UVC-irradiation is not yet clear. This study elucidated a novel eIF2alpha phosphorylation-centered network for the regulation of COX-2 expression after UVC-irradiation.
Collapse
|
27
|
Zhang J, Bowden GT. UVB irradiation regulates Cox-2 mRNA stability through AMPK and HuR in human keratinocytes. Mol Carcinog 2008; 47:974-83. [PMID: 18449856 DOI: 10.1002/mc.20450] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Considerable evidence has demonstrated that UVB irradiation is a strong carcinogen for nonmelanoma skin cancer. Up-regulation of cyclooxygenase-2 (Cox-2) has been shown to be a crucial event in human keratinocytes in their responses to UVB irradiation. To further understand the molecular mechanisms governing Cox-2 regulation, we found that UVB irradiation significantly increased Cox-2 mRNA stability by inducing cytoplasmic localization and protein abundance of human antigen R (HuR). We also found that AMP-activated kinase (AMPK) mediates these events and that UVB reduces AMPK activity by down-regulating LKB1 kinase. Finally, we propose a novel model in which UVB regulates Cox-2 mRNA stability through the LKB1/AMPK pathway.
Collapse
Affiliation(s)
- Jack Zhang
- Arizona Cancer Center, Tucson, Arizona 85724, USA
| | | |
Collapse
|
28
|
McMillan TJ, Leatherman E, Ridley A, Shorrocks J, Tobi SE, Whiteside JR. Cellular effects of long wavelength UV light (UVA) in mammalian cells. J Pharm Pharmacol 2008; 60:969-76. [PMID: 18644190 DOI: 10.1211/jpp.60.8.0004] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
UVA should receive significant consideration as a human health risk as it is a large proportion of the solar spectrum that reaches the earth's surface and because of its ability to penetrate human skin. It is only relatively recently that this has been recognized and this previously under-researched part of the UV spectrum is becoming increasingly well characterized at doses that are quite low in relation to those experienced by humans. Absorption of UVA in a cell leads to the production of reactive oxygen and nitrogen species that can damage major biomolecules including DNA and membrane lipids. Various types of damage induced in these molecules lead to significant biological effects including cytotoxicity, mutations and alterations in cell signalling pathways. Longer-term effects such as persistent genomic instability and bystander effects have also been observed following UVA treatment of mammalian cells and, as with ionizing radiation, this changes some of the fundamental thinking around tissue effects of irradiation. Antioxidants have been assessed extensively for their ability to protect against the biological effects of UVA and a number have been shown to be successful at least in-vitro, for example vitamin E and epigallocatechin-3-gallate. Other potential targets for protection are suggested through the increased understanding of some of the signalling mechanisms activated following treatment, for example the inhibition of NADPH oxidase is seen to reduce a bystander effect. The search for appropriate and successful photoprotective agents remains an important area of research.
Collapse
Affiliation(s)
- T J McMillan
- Biomedical Sciences Unit, Department of Biological Sciences, Lancaster University Lancaster, LA1 4YQ, UK.
| | | | | | | | | | | |
Collapse
|
29
|
Sun H, Xu B, Inoue H, Chen QM. p38 MAPK mediates COX-2 gene expression by corticosterone in cardiomyocytes. Cell Signal 2008; 20:1952-9. [DOI: 10.1016/j.cellsig.2008.07.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2008] [Revised: 06/19/2008] [Accepted: 07/03/2008] [Indexed: 01/09/2023]
|
30
|
Kim SC, Park SS, Lee YJ. Effect of UV irradiation on colorectal cancer cells with acquired TRAIL resistance. J Cell Biochem 2008; 104:1172-80. [PMID: 18247342 DOI: 10.1002/jcb.21682] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a member of the TNF superfamily. TRAIL shows strong cytotoxicity to many cancer cells but minimal cytotoxicity to most normal cells. Interestingly, our recent studies have demonstrated that pretreatment with TRAIL induces acquired resistance to TRAIL (Song et al. 2007 J Biol Chem 282: 319). Acquired TRAIL resistance develops within 1 day and gradually decays within 5 days after TRAIL treatment. In our current study, we examined whether human colorectal carcinoma CX-1 cells with acquired TRAIL resistance are resistant to UV irradiation as well. CX-1 cells were treated with 200 ng/ml TRAIL for 6 h and incubated various times (0.25-5 days) and then challenged to UV irradiation. Unexpectedly, we observed an increase in apoptosis in acquired TRAIL resistant cells after UVC as well as UVB exposure. This was due to an increase in caspase activation which was mediated through cytochrome c release. These results suggest that cells with acquired TRAIL resistance are sensitive to UV irradiation.
Collapse
Affiliation(s)
- Seong C Kim
- Department of Surgery and Pharmacology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
| | | | | |
Collapse
|
31
|
Einspahr JG, Timothy Bowden G, Alberts DS, McKenzie N, Saboda K, Warneke J, Salasche S, Ranger-Moore J, Curiel-Lewandrowski C, Nagle RB, Nickoloff BJ, Brooks C, Dong Z, Stratton SP. Cross-validation of Murine UV Signal Transduction Pathways in Human Skin. Photochem Photobiol 2008; 84:463-76. [DOI: 10.1111/j.1751-1097.2007.00287.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
|
32
|
Chêne G, Dubourdeau M, Balard P, Escoubet-Lozach L, Orfila C, Berry A, Bernad J, Aries MF, Charveron M, Pipy B. n-3 and n-6 polyunsaturated fatty acids induce the expression of COX-2 via PPARgamma activation in human keratinocyte HaCaT cells. Biochim Biophys Acta Mol Cell Biol Lipids 2007; 1771:576-89. [PMID: 17459764 DOI: 10.1016/j.bbalip.2007.02.014] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2006] [Revised: 12/31/2006] [Accepted: 02/21/2007] [Indexed: 01/22/2023]
Abstract
Polyunsaturated fatty acids (PUFA) n-3 inhibit inflammation, in vivo and in vitro in keratinocytes. We examined in HaCaT keratinocyte cell line whether eicosapentaenoic acid (EPA) a n-3 PUFA, gamma-linoleic acid (GLA) a n-6 PUFA, and arachidic acid a saturated fatty acid, modulate expression of cyclooxygenase-2 (COX-2), an enzyme pivotal to skin inflammation and reparation. We demonstrate that only treatment of HaCaT with GLA and EPA or a PPARgamma ligand (roziglitazone), induced COX-2 expression (protein and mRNA). Moreover stimulation of COX-2 promoter activity was increased by those PUFAs or rosiglitazone. The inhibitory effects of GW9662 and T0070907 (PPARgamma antagonists), on COX-2 expression and on stimulation of COX-2 promoter activity by EPA and GLA suggest that PPARgamma is implicated in COX-2 induction. Finally, PLA2 inhibitor methyl arachidonyl fluorophosphonate blocked the PUFA effects on COX-2 induction, promoter activity and arachidonic acid mobilization suggesting involvement of AA metabolites in PPAR activation. These findings demonstrate that n-3 and n-6 PUFA increased PPARgamma activity is necessary for the COX-2 induction in HaCaT human keratinocyte cells. Given the anti-inflammatory properties of EPA, we suggest that induction of COX-2 in keratinocytes may be important in the anti-inflammatory and protective mechanism of action of PUFAs n-3 or n-6.
Collapse
Affiliation(s)
- Gérald Chêne
- Macrophages, Mediateurs de l'Inflammation et Interactions Cellulaires, Université Paul Sabatier, EA 2405- INSERM IFR 31, Institut Louis Bugnard, BP 84225, 31432 Toulouse CEDEX 4, France
| | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Jinlian L, Yingbin Z, Chunbo W. p38 MAPK in regulating cellular responses to ultraviolet radiation. J Biomed Sci 2007; 14:303-12. [PMID: 17334833 DOI: 10.1007/s11373-007-9148-4] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2006] [Accepted: 12/26/2006] [Indexed: 11/28/2022] Open
Abstract
Solar ultraviolet (UV) radiation is a major environmental factor that causes DNA damage, inflammation, erythema, sunburn, immunosuppression, photoaging, gene mutations, and skin cancer. p38 mitogen activated protein kinase (MAPK) are strongly activated by UV radiation, and play important roles in regulating cellular responses to UV. In this review, we examine the role played by p38 MAPK in mediating UV-induced cell cycle, apoptosis, inflammation, and skin tanning response. We review the role played by p38 MAPK in transcriptional regulation of key downstream genes that have been implicated in the regulation of cellular responses to UV radiation. Understanding this will undoubtedly help in the prevention and control of UV-induced damage and the development of novel therapeutic strategies.
Collapse
Affiliation(s)
- Li Jinlian
- Medical College, Qingdao University, 422 Room, Boya Building, 308 Ningxia Road, Qingdao, 266071, China.
| | | | | |
Collapse
|
34
|
Boswell SA, Ongusaha PP, Nghiem P, Lee SW. The protective role of a small GTPase RhoE against UVB-induced DNA damage in keratinocytes. J Biol Chem 2006; 282:4850-4858. [PMID: 17170105 DOI: 10.1074/jbc.m610532200] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
RhoE, a p53 target gene, was identified as a critical factor for the survival of human keratinocytes in response to UVB. The Rho family of GTPases regulates many aspects of cellular behavior through alterations to the actin cytoskeleton, acting as molecular switches cycling between the active, GTP-bound and the inactive, GDP-bound conformations. Unlike typical Rho family proteins, RhoE (also known as Rnd3) is GTPase-deficient and thus expected to be constitutively active. In this study, we investigated the response of cultured human keratinocyte cells to UVB irradiation. RhoE protein levels increase upon exposure to UVB, and ablation of RhoE induction through small interfering RNA resulted in a significant increase in apoptosis and a reduction in the levels of the pro-survival targets p21, Cox-2, and cyclin D1, as well as an increase of reactive oxygen species levels when compared with control cells. These data indicate that RhoE is a pro-survival factor acting upstream of p38, JNK, p21, and cyclin D1. HaCat cells expressing small interfering RNA to p53 indicate that RhoE functions independently of its known associates, p53 and Rho-associated kinase I (ROCK I). Targeted expression of RhoE in epidermis using skin-specific transgenic mouse model resulted in a significant reduction in the number of apoptotic cells following UVB irradiation. Thus, RhoE induction counteracts UVB-induced apoptosis and may serve as a novel target for the prevention of UVB-induced photodamage regardless of p53 status.
Collapse
Affiliation(s)
- Sarah A Boswell
- Dermatology Division, University of Washington, Seattle, Washington 98109
| | - Pat P Ongusaha
- Cutaneous Biology Research Center (CBRC), Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129 and the
| | - Paul Nghiem
- Dermatology Division, University of Washington, Seattle, Washington 98109
| | - Sam W Lee
- Cutaneous Biology Research Center (CBRC), Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129 and the.
| |
Collapse
|
35
|
Tong X, Van Dross RT, Abu-Yousif A, Morrison AR, Pelling JC. Apigenin prevents UVB-induced cyclooxygenase 2 expression: coupled mRNA stabilization and translational inhibition. Mol Cell Biol 2006; 27:283-96. [PMID: 17074806 PMCID: PMC1800648 DOI: 10.1128/mcb.01282-06] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cyclooxygenase 2 (COX-2) is a key enzyme in the conversion of arachidonic acid to prostaglandins, and COX-2 overexpression plays an important role in carcinogenesis. Exposure to UVB strongly increased COX-2 protein expression in mouse 308 keratinocytes, and this induction was inhibited by apigenin, a nonmutagenic bioflavonoid that has been shown to prevent mouse skin carcinogenesis induced by both chemical carcinogens and UV exposure. Our previous study suggested that one pathway by which apigenin inhibits UV-induced and basal COX-2 expression is through modulation of USF transcriptional activity in the 5' upstream region of the COX-2 gene. Here, we found that apigenin treatment also increased COX-2 mRNA stability, and the inhibitory effect of apigenin on UVB-induced luciferase reporter gene activity was dependent on the AU-rich element of the COX-2 3'-untranslated region. Furthermore, we identified two RNA-binding proteins, HuR and the T-cell-restricted intracellular antigen 1-related protein (TIAR), which were associated with endogenous COX-2 mRNA in 308 keratinocytes, and apigenin treatment increased their localization to cell cytoplasm. More importantly, reduction of HuR levels by small interfering RNA inhibited apigenin-mediated stabilization of COX-2 mRNA. Cells expressing reduced TIAR showed marked resistance to apigenin's ability to inhibit UVB-induced COX-2 expression. Taken together, these results indicate that in addition to transcriptional regulation, another mechanism by which apigenin prevents COX-2 expression is through mediating TIAR suppression of translation.
Collapse
Affiliation(s)
- Xin Tong
- Department of Pathology, Northwestern University, 303 E. Superior Street, Chicago, IL 60611, USA
| | | | | | | | | |
Collapse
|
36
|
Millán O, Rico D, Peinado H, Zarich N, Stamatakis K, Pérez-Sala D, Rojas JM, Cano A, Boscá L. Potentiation of tumor formation by topical administration of 15-deoxy-delta12,14-prostaglandin J2 in a model of skin carcinogenesis. Carcinogenesis 2006; 27:328-36. [PMID: 16113051 DOI: 10.1093/carcin/bgi213] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The effect of prostaglandins on the development of papillomas has been investigated in mice receiving prostaglandins E2 (PGE2) or the cyclopentenone 15-deoxy-delta(12,14)-PGJ2 (15dPGJ2) topically, using the 7,12-dimethylbenz[a]anthracene (DMBA)-induced tetradecanoylphorbol acetate (TPA)-promoted model of skin carcinogenesis. The presence of 15dPGJ2 during DMBA and TPA treatment inhibited apoptosis and increased the rate, number, size and vascularization of the papillomas, some of them progressing into carcinomas. Moreover, skin sections from mice treated for one week with DMBA and 15dPGJ2 showed a much reduced rate of apoptotic cells, and an enhanced expression of vascular epithelial growth factor when compared with animals receiving DMBA, with or without PGE2. The analysis of molecular events in the MCA3D keratinocyte cell line showed that 15dPGJ2 activated Ras and improved cell viability by inhibiting DMBA-dependent apoptosis. In addition to this, cell adhesion was impaired in MCA3D keratinocytes co-treated with 15dPGJ2 and DMBA, at the same time when the expression of cyclooxygenase-2 (COX-2) was observed under these conditions. These effects mediated by 15dPGJ2 might contribute to understand the role of COX-2 metabolites in carcinogenesis, leading to an increase of cell viability after mutagenic injury and therefore in the progression of tumors.
Collapse
Affiliation(s)
- Olga Millán
- Instituto de Bioquímica, CSIC-UCM, 28040 Madrid, Spain
| | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Degner SC, Kemp MQ, Bowden GT, Romagnolo DF. Conjugated linoleic acid attenuates cyclooxygenase-2 transcriptional activity via an anti-AP-1 mechanism in MCF-7 breast cancer cells. J Nutr 2006; 136:421-7. [PMID: 16424122 DOI: 10.1093/jn/136.2.421] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Overexpression of cyclooxygenase-2 (COX-2) is regarded as a causative factor in the onset of tumorigenesis of the breast. In this study, we investigated the effects of conjugated linoleic acid (CLA) on COX-2 transcription in MCF-7 breast cancer cells. Results of transient transfection studies revealed that treatment with a CLA mix or selected isomers (c9, t11-CLA; t10, c12-CLA) at concentrations ranging from 20 to 80 micromol/L, attenuated COX-2 transcription induced by the proinflammatory agent 12-O-tetradecanoylphorbol-13-acetate (TPA). In addition, the CLA mix inhibited TPA-induced activity of the collagenase-1 promoter. Using electrophoretic mobility shift assays, we found that the CLA mix reduced TPA-induced recruitment of nuclear proteins to a cAMP response element (CRE) in the COX-2 promoter and a consensus TPA-responsive element (TRE) in the collagenase-1 promoter. Both CRE and TRE are binding sites for activator protein-1 (AP-1). Binding studies revealed that the t10, c12-CLA isomer was more effective than the CLA mix or c9, t11-CLA in reducing binding of cJun to either the COX-2 CRE or collagenase-1 TRE, whereas linoleic acid increased binding to both elements. Overexpression of the AP-1 member, c-Jun, reversed the inhibitory effects of the CLA mix on COX-2 transcription, and restored binding of nuclear proteins to the CRE and TRE. Collectively, these results suggest that CLA represses AP-1-mediated activation of COX-2 transcription.
Collapse
Affiliation(s)
- Stephanie C Degner
- Department of Nutritional Sciences, Arizona Cancer Center, The University of Arizona, Tucson, AZ 85721, USA
| | | | | | | |
Collapse
|
38
|
Wondrak GT, Jacobson MK, Jacobson EL. Endogenous UVA-photosensitizers: mediators of skin photodamage and novel targets for skin photoprotection. Photochem Photobiol Sci 2006; 5:215-37. [PMID: 16465308 DOI: 10.1039/b504573h] [Citation(s) in RCA: 273] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Endogenous chromophores in human skin serve as photosensitizers involved in skin photocarcinogenesis and photoaging. Absorption of solar photons, particularly in the UVA region, induces the formation of photoexcited states of skin photosensitizers with subsequent generation of reactive oxygen species (ROS), organic free radicals and other toxic photoproducts that mediate skin photooxidative stress. The complexity of endogenous skin photosensitizers with regard to molecular structure, pathways of formation, mechanisms of action, and the diversity of relevant skin targets has hampered progress in this area of photobiology and most likely contributed to an underestimation of the importance of endogenous sensitizers in skin photodamage. Recently, UVA-fluorophores in extracellular matrix proteins formed posttranslationally as a consequence of enzymatic maturation or spontaneous chemical damage during chronological and actinic aging have been identified as an abundant source of light-driven ROS formation in skin upstream of photooxidative cellular stress. Importantly, sensitized skin cell photodamage by this bystander mechanism occurs after photoexcitation of sensitizers contained in skin structural proteins without direct cellular photon absorption thereby enhancing the potency and range of phototoxic UVA action in deeper layers of skin. The causative role of photoexcited states in skin photodamage suggests that direct molecular antagonism of photosensitization reactions using physical quenchers of photoexcited states offers a novel chemopreventive opportunity for skin photoprotection.
Collapse
Affiliation(s)
- Georg T Wondrak
- Department of Pharmacology and Toxicology, College of Pharmacy, Arizona Cancer Center, University of Arizona, 1515 North Campbell Avenue, Tucson, AZ, USA
| | | | | |
Collapse
|
39
|
Assefa Z, Van Laethem A, Garmyn M, Agostinis P. Ultraviolet radiation-induced apoptosis in keratinocytes: on the role of cytosolic factors. Biochim Biophys Acta Rev Cancer 2005; 1755:90-106. [PMID: 15964692 DOI: 10.1016/j.bbcan.2005.04.001] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2004] [Revised: 04/04/2005] [Accepted: 04/19/2005] [Indexed: 01/14/2023]
Abstract
Epidemiological and experimental evidences have established solar ultraviolet (UV) radiation as the leading cause of skin cancers. Specifically, the frequency of non-melanoma skin cancer, one of the malignancies with the most rapidly increasing incidence, is directly related to the total exposure to solar UV light. As part of a general effort to elucidate the components of cellular signal transduction pathways, the mechanisms of cellular responses to UV radiation have received considerable attention over the last few years. These efforts were driven mainly by the conviction that understanding how normal cells respond to extracellular stimuli such as exposure to UV radiation will undoubtedly help in deciphering what goes wrong in a variety of clinical disorders including skin cancers and will assist in the development of novel therapeutic strategies. Studies over the last decade have established that UV radiation induces a bewildering array of signal transduction pathways, some of which could lead to apoptotic cell death. UV-induced cell death by apoptosis is considered to be a natural protective mechanism that removes damaged keratinocytes and circumvents the risk of malignant transformation. In this review, we summarize some of the most important findings regarding the response and role of mitogen-activated protein kinases in UVA and UVB radiation-induced signaling to apoptosis in keratinocytes. We will also briefly discuss what is known about the role of the BCL-2 family of proteins, the emerging role of lysosomal proteases and other important cytosolic signaling proteins in UV-induced apoptosis.
Collapse
Affiliation(s)
- Zerihun Assefa
- Department of Molecular Cell Biology, Division of Physiology, Faculty of Medicine, Katholieke Universiteit Leuven, Leuven, Belgium.
| | | | | | | |
Collapse
|
40
|
Bachelor MA, Bowden GT. Ultraviolet A-induced modulation of Bcl-XL by p38 MAPK in human keratinocytes: post-transcriptional regulation through the 3'-untranslated region. J Biol Chem 2004; 279:42658-68. [PMID: 15292226 DOI: 10.1074/jbc.m406626200] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
We examined the effect of inhibiting p38 MAPK on UVA-irradiated HaCaT cells, a spontaneously immortalized human keratinocyte cell line. Recent work from our laboratory has shown that UVA (250 kJ/m2) induces a rapid phosphorylation of p38 MAPK in the HaCaT cell line. Inhibition of p38 MAPK activity through the use of a specific inhibitor, SB202190, in combination with UVA treatment induced a rapid cleavage of caspase-9, caspase-8, and caspase-3, whereas UVA irradiation alone had no effect. Similarly, cleavage of the caspase substrate poly(ADP-ribose) polymerase was observed in UVA-irradiated HaCaT cells treated with SB202190 or in cells expressing a dominant-negative p38 MAPK. No effect of p38 MAPK inhibition upon caspase cleavage was observed in mock-irradiated HaCaT cells. In addition, increases in apoptosis were observed in UVA-irradiated cells treated with SB202190 by morphological analysis with no significant apoptosis occurring from UVA irradiation alone. Similar results were obtained by using normal human epidermal keratinocytes. UVA induced expression of the anti-apoptotic Bcl-2 family member, Bcl-XL, with abrogation of expression by using the p38 MAPK inhibitor SB202190. Overexpression of Bcl-XL prevented poly(ADP-ribose) polymerase cleavage induced by the combination of UVA and p38 MAPK inhibition. UVA enhanced the stability of Bcl-XL mRNA through increases in p38 MAPK activity. We determined that increases in UVA-induced expression of Bcl-XL occur through a posttranscriptional mechanism mediated by the 3'-untranslated region (UTR). We used Bcl-XL 3'-UTR luciferase constructs to determine the mechanism by which UVA increased Bcl-XL mRNA stability. Additionally, RNA binding studies indicate that UVA increases the binding of RNA-binding proteins to Bcl-XL 3'-UTR mRNA, which can be decreased by using SB202190. In conclusion, p38 MAPK and Bcl-XL expression play critical roles in the survival of UVA-irradiated HaCaT cells.
Collapse
Affiliation(s)
- Michael A Bachelor
- Department of Cell Biology and Anatomy, Arizona Cancer Center, the University of Arizona, Tucson, Arizona 85724, USA
| | | |
Collapse
|
41
|
Nicolaou A, Estdale SE, Tsatmali M, Herrero DP, Thody AJ. Prostaglandin production by melanocytic cells and the effect of α-melanocyte stimulating hormone. FEBS Lett 2004; 570:223-6. [PMID: 15251468 DOI: 10.1016/j.febslet.2004.06.041] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2004] [Revised: 06/18/2004] [Accepted: 06/21/2004] [Indexed: 10/26/2022]
Abstract
Prostaglandins are potent mediators of the inflammatory response and are also involved in cancer development. In this study, we show that human melanocytes and FM55 melanoma cells express cyclooxygenase-1 and -2 (COX-1 and -2) and thus have the capability to produce prostaglandins. The FM55 cells produced predominantly PGE2 and PGF2alpha, whereas the HaCaT keratinocyte cell line produced mainly PGE2. The anti-inflammatory peptide, alpha-melanocyte stimulating hormone (alpha-MSH), reduced prostaglandin production in FM55 and HaCaT cells and reversed the effect of the pro-inflammatory cytokine TNF-alpha in the former. These results indicate that melanocytes produce prostaglandins and that alpha-MSH, by inhibiting this response, may play an important role in regulating inflammatory responses in the skin.
Collapse
Affiliation(s)
- Anna Nicolaou
- School of Pharmacy, University of Bradford, Bradford BD7 1DP, UK.
| | | | | | | | | |
Collapse
|
42
|
Wondrak GT, Roberts MJ, Jacobson MK, Jacobson EL. 3-hydroxypyridine chromophores are endogenous sensitizers of photooxidative stress in human skin cells. J Biol Chem 2004; 279:30009-20. [PMID: 15133022 DOI: 10.1074/jbc.m404379200] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Photocarcinogenesis and photoaging are established consequences of chronic exposure of human skin to solar irradiation. Accumulating evidence supports a causative involvement of UVA irradiation in skin photo-damage. UVA photodamage has been attributed to photosensitization by endogenous skin chromophores leading to the formation of reactive oxygen species and organic free radicals as key mediators of cellular photooxidative stress. In this study, 3-hydroxypyridine derivatives contained in human skin have been identified as a novel class of potential endogenous photosensitizers. A structure-activity relationship study of skin cell photosensitization by endogenous pyridinium derivatives (pyridinoline, desmosine, pyridoxine, pyridoxamine, pyridoxal, pyridoxal-5'-phosphate) and various synthetic hydroxypyridine isomers identified 3-hydroxypyridine and N-alkyl-3-hydroxypyridinium cation as minimum phototoxic chromophores sufficient to effect skin cell sensitization toward UVB and UVA, respectively. Photosensitization of cultured human skin keratinocytes (HaCaT) and fibroblasts (CF3) by endogenous and synthetic 3-hydroxypyridine derivatives led to a dose-dependent inhibition of proliferation, cell cycle arrest in G2/M, and induction of apoptosis, all of which were reversible by thiol antioxidant intervention. Enhancement of UVA-induced intracellular peroxide formation and p38 mitogen-activated protein kinase-dependent stress signaling suggest a photooxidative mechanism of skin cell photosensitization by 3-hydroxypyridine derivatives. 3-hydroxypyridine derivatives were potent photosensitizers of macromolecular damage, effecting protein (RNase A) photocross-linking and peptide (melittin) photooxidation with incorporation of molecular oxygen. Based on these results, we conclude that 3-hydroxypyridine derivatives comprising a wide range of skin biomolecules, such as enzymatic collagen cross-links, B6 vitamers, and probably advanced glycation end products in chronologically aged skin constitute a novel class of UVA photosensitizers, capable of skin photooxidative damage.
Collapse
Affiliation(s)
- Georg T Wondrak
- Department of Pharmacology and Toxicology, College of Pharmacy, Arizona Cancer Center, University of Arizona, Tucson, Arizona 85724, USA
| | | | | | | |
Collapse
|
43
|
Silvers AL, Bachelor MA, Bowden GT. The role of JNK and p38 MAPK activities in UVA-induced signaling pathways leading to AP-1 activation and c-Fos expression. Neoplasia 2004; 5:319-29. [PMID: 14511403 PMCID: PMC1502419 DOI: 10.1016/s1476-5586(03)80025-8] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
To further delineate ultraviolet A (UVA) signaling pathways in the human keratinocyte cell line HaCaT, we examined the potential role of mitogen-activated protein kinases (MAPKs) in UVA-induced activator protein-1 (AP-1) transactivation and c-Fos expression. UVA-induced phosphorylation of p38 and c-Jun N-terminal kinase (JNK) proteins was detected immediately after irradiation and disappeared after approximately 2 hours. Conversely, phosphorylation of extracellular signal-regulated kinase was significantly inhibited for up to 1 hour post-UVA irradiation. To examine the role of p38 and JNK MAPKs in UVA-induced AP-1 and c-fos transactivations, the selective pharmacologic MAPK inhibitors, SB202190 (p38 inhibitor) and SP600125 (JNK inhibitor), were used to independently treat stably transfected HaCaT cells in luciferase reporter assays. Both SB202190 and SP600125 dose-dependently inhibited UVA-induced AP-1 and c-fos transactivations. SB202190 (0.25-0.5 microM) and SP600125 (62-125 nM) treatments also primarily inhibited UVA-induced c-Fos expression. These results demonstrated that activation of both JNK and p38 play critical role in UVA-mediated AP-1 transactivation and c-Fos expression in these human keratinocyte cells. Targeted inhibition of these MAPKs with their selective pharmacologic inhibitors may be effective chemopreventive strategies for UVA-induced nonmelanoma skin cancer.
Collapse
Affiliation(s)
- Amy L Silvers
- Department of Radiation Oncology, Arizona Cancer Center, The University of Arizona, Tucson, AZ, USA
| | | | | |
Collapse
|
44
|
Bachelor MA, Bowden GT. UVA-mediated activation of signaling pathways involved in skin tumor promotion and progression. Semin Cancer Biol 2004; 14:131-8. [PMID: 15018897 DOI: 10.1016/j.semcancer.2003.09.017] [Citation(s) in RCA: 185] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Each year more than 1,000,000 cases of non-melanoma skin cancer (NMSC) are diagnosed in the Unites States. Solar radiation has been described as an important etiological factor in the development of NMSC. UVA comprises the largest portion of solar radiation reaching the surface of the earth (90-99%) and has been described to lead to benign tumor formation as well as malignant cancers, squamous cell carcinomas (SCCs). While much research has focused upon the effects of UVB radiation, little is known about UVA-induced signaling pathways and their role in tumor promotion. Here we focus on UVA-mediated activation of mitogen-activated protein kinase (MAPK) pathways and their role in activator protein-1 (AP-1) mediated transcription and cyclooxygenase-2 (COX-2) expression. AP-1 and COX-2 have been found to play a role in angiogenesis in other tissues. We propose UVA-mediated increases in AP-1 and COX-2 may play a role in tumor promotion through increases in interleukin-8 (IL-8) and vascular endothelial growth factor (VEGF). Since MAPKs, specifically p38 and JNK, appear to play a major role in the expression of UVA-induced AP-1 and COX-2, pharmacological inhibitors may be of benefit in the chemoprevention of non-melanoma skin cancer.
Collapse
Affiliation(s)
- Michael A Bachelor
- Department of Radiation Oncology, Arizona Cancer Center, College of Medicine, The University of Arizona, 1515 North Campbell Avenue, Tucson, AZ 85724, USA
| | | |
Collapse
|
45
|
Arbiser JL. Molecular regulation of angiogenesis and tumorigenesis by signal transduction pathways: evidence of predictable and reproducible patterns of synergy in diverse neoplasms. Semin Cancer Biol 2004; 14:81-91. [PMID: 15018892 DOI: 10.1016/j.semcancer.2003.09.013] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A large number of oncogenes, tumor suppressor genes, and signal transduction pathways have been described. Currently, a framework that allows prediction of tumor behavior based upon oncogenes, tumor suppressors, and signal transduction pathways is lacking. In 1869, Mendeleev published a periodic table of elements which allowed prediction of properties of elements based upon atomic weights that allowed prediction of chemical and physical properties of elements yet to be discovered. In this paper, I will discuss recurrent patterns of synergy found in the literature and our laboratory between tumor suppressor genes, oncogenes, and signaling pathways that allows one to predict the signaling pathway in a given tumor based upon the inactivation of a tumor suppressor gene. These patterns can be found in multiple different human neoplasms. Conversely, one can predict the inactivation of a tumor suppressor based upon the activation status of a signaling pathway. This knowledge can be used by a clinician or pathologist with access to immunohistochemistry to make predictions based upon simple technologies and determine the signaling pathways involved in a patient's tumor. These strategies may be useful in the design of prevention and treatment strategies for cancer.
Collapse
Affiliation(s)
- Jack L Arbiser
- Department of Dermatology, Emory University School of Medicine, WMB 5309, 1639 Pierce Drive, Atlanta, GA 30322, USA.
| |
Collapse
|
46
|
Sully G, Dean JLE, Wait R, Rawlinson L, Santalucia T, Saklatvala J, Clark AR. Structural and functional dissection of a conserved destabilizing element of cyclo-oxygenase-2 mRNA: evidence against the involvement of AUF-1 [AU-rich element/poly(U)-binding/degradation factor-1], AUF-2, tristetraprolin, HuR (Hu antigen R) or FBP1 (far-upstream-sequence-element-binding protein 1). Biochem J 2004; 377:629-39. [PMID: 14594446 PMCID: PMC1223914 DOI: 10.1042/bj20031484] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2003] [Revised: 10/30/2003] [Accepted: 10/31/2003] [Indexed: 11/17/2022]
Abstract
COX-2 (cyclo-oxygenase-2) mRNA is degraded rapidly in resting cells, but is stabilized by the mitogen-activated protein kinase p38 signalling pathway in response to pro-inflammatory stimuli. A conserved ARE (AU-rich element) of the COX-2 3' untranslated region, CR1 (conserved region 1), acts as a potent instability determinant, and mediates stabilization in response to p38 activation. A detailed structural and functional analysis of this element was performed in an attempt to identify RNA-binding proteins involved in the regulation of COX-2 mRNA stability. Destabilization of a beta-globin reporter mRNA was dependent upon two distinct AREs within CR1, each containing three copies of the sequence AUUUA. CR1 was shown to bind AUF-1 [ARE/poly(U)-binding/degradation factor-1] and/or AUF-2, HuR (Hu antigen R), TTP (tristetraprolin) and FBP1 (far-upstream-sequence-element-binding protein 1), yet these factors did not appear to account for the effects of CR1 upon mRNA stability. Mutant sequences were identified that were incapable of destabilizing a reporter mRNA, yet showed unimpaired binding of FBP1 and AUF-1 and/or -2. TTP was absent from the HeLa cell line used in this analysis. Finally, RNA interference experiments argued against a prominent role for HuR in the CR1-mediated regulation of mRNA stability. We conclude that at least one critical regulator of COX-2 mRNA stability is likely to remain unidentified at present.
Collapse
Affiliation(s)
- Gareth Sully
- Kennedy Institute of Rheumatology Division, Faculty of Medicine, Imperial College London, 1 Aspenlea Road, Hammersmith, London W6 8LH, U.K
| | | | | | | | | | | | | |
Collapse
|
47
|
Afaq F, Ahmad N, Mukhtar H. Suppression of UVB-induced phosphorylation of mitogen-activated protein kinases and nuclear factor kappa B by green tea polyphenol in SKH-1 hairless mice. Oncogene 2004; 22:9254-64. [PMID: 14681684 DOI: 10.1038/sj.onc.1207035] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Studies from our laboratory have shown that epigallocatechin-3-gallate, the major polyphenol present in green tea, inhibits ultraviolet (UV)B-exposure-mediated phosphorylation of mitogen-activated protein kinases (MAPKs) (Toxicol. Appl. Pharmacol. 176: 110-117, 2001) and activation of nuclear factor kappa B (NF-kappaB) (Oncogene 22: 1035-1044, 2003) pathways in normal human epidermal keratinocytes. This study was designed to investigate the relevance of these findings to the in vivo situations in SKH-1 hairless mouse model, which is regarded to have relevance to human situations. SKH-1 hairless mice were topically treated with GTP (5 mg/0.2 ml acetone/mouse) and were exposed to UVB 30 min later (180 mJ/cm2). These treatments were repeated every alternate day for 2 weeks, for a total of seven treatments. The animals were killed 24 h after the last UVB exposure. Topical application of GTP resulted in significant decrease in UVB-induced bifold-skin thickness, skin edema and infiltration of leukocytes. Employing Western blot analysis and immunohistochemical studies, we found that GTP resulted in inhibition of UVB-induced: (i) phosphorylation of extracellular-signal-regulated kinases (ERK1/2), (ii) c-Jun N-terminal kinases, and (iii) p38 protein expression. Since NF-kappaB plays a major role in inflammation and cell proliferation, we assessed the effect of GTP on UVB-mediated modulations in the NF-kappaB pathway. Our data demonstrated that GTP inhibited UVB-induced: (i) activation of NF-kappaB, (ii) activation of IKKalpha, and (iii) phosphorylation and degradation of IkappaBalpha. Our data suggest that GTP protects against the adverse effects of UV radiation via modulations in MAPK and NF-kappaB signaling pathways, and provides molecular basis for the photochemopreventive effect of GTP in an in vivo animal model system.
Collapse
Affiliation(s)
- Farrukh Afaq
- Department of Dermatology, University of Wisconsin, Madison, WI 53706, USA
| | | | | |
Collapse
|
48
|
Mahns A, Wolber R, Stäb F, Klotz LO, Sies H. Contribution of UVB and UVA to UV-dependent stimulation of cyclooxygenase-2 expression in artificial epidermis. Photochem Photobiol Sci 2004; 3:257-62. [PMID: 14993941 DOI: 10.1039/b309067a] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Both UVB (280-320 nm) and UVA (320-400 nm) radiation lead to an enhanced expression of cyclooxygenase-2 (COX-2) in epidermal cells in various in-vitro and in-vivo models. It is demonstrated here that the expression of COX-2 is induced in artificial human epidermis exposed to simulated solar light (>290 nm). Employing filters eliminating specified regions from the simulated solar spectrum, the UVB and UVA-2 (320-350 nm) regions are shown to fully account for induction of COX-2 mRNA and protein as well as the enhanced production of prostaglandin E(2) after irradiation. At the protein level, approximately 70% of the total induction by solar light is due to light in the UVA-2 region. UVA-1 (350-400 nm), visible light and IR radiation are practically ineffective. COX-2 induction by simulated solar light is attenuated in the presence of inhibitors of p38(MAPK) or of c-Jun-N-terminal kinases (JNK), whereas COX-2 induction by UVA is blocked only by inhibition of JNK. UV-induced COX-2 expression is not affected by inhibition of the MEK 1,2/ERK 1,2 pathways.
Collapse
Affiliation(s)
- André Mahns
- Institut fur Biochemie und Molekularbiologie I, Heinrich-Heine-Universitat Dusseldorf, 40225 Dusseldorf, Germany
| | | | | | | | | |
Collapse
|
49
|
De Felice B, Santillo M, Serù R, Damiano S, Matrone G, Wilson RR, Mondola P. Modulation of 3-hydroxy-3-methylglutaryl-CoA reductase gene expression by CuZn superoxide dismutase in human fibroblasts and HepG2 cells. Gene Expr 2004; 12:29-38. [PMID: 15473258 PMCID: PMC6009104 DOI: 10.3727/000000004783992198] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/08/2004] [Indexed: 11/24/2022]
Abstract
The homeostasis of intracellular cholesterol in animal cells is highly regulated by a complex system in which the microsomal rate-limiting enzyme 3-hydroxy-3-methylglutaryl CoA (HMG-CoA) reductase plays a key role in cholesterol synthesis. Substantial evidence has demonstrated that the cytosolic antioxidant enzyme CuZn superoxide dismutase (SOD1) inhibits the HMG-CoA reductase activity in rat hepatocytes and in human fibroblasts by decreasing cholesterol synthesis. Although these data suggest that SOD1 exerts a physiological role in cholesterol metabolism, it is still unclear whether the decrease of HMG-CoA reductase activity is mediated by transcriptional or by posttranscriptional events. The results of the present study, obtained by one-step RT-PCR assay, demonstrated that both SOD1 and the metal-free form of enzyme (Apo SOD1) inhibit HMG-CoA reductase gene expression in hepatocarcinoma HepG2 cells, in normal human fibroblasts, and in fibroblasts of subjects affected by familiar hypercholesterolemia. Accordingly, SOD1 could be used as a potential agent in the treatment of hypercholesterolemia, even in subjects lacking a functional LDL receptor pathway.
Collapse
Affiliation(s)
- Bruna De Felice
- *Department of Life Sciences, University of Naples 2, Via Vivaldi, 43, 81100, Caserta, Italy
| | - Mariarosaria Santillo
- †Department of Neuroscience, Unit of Physiology, University of Naples “Federico II,”Via S. Pansini, 5, 80131, Naples, Italy
| | - Rosalba Serù
- †Department of Neuroscience, Unit of Physiology, University of Naples “Federico II,”Via S. Pansini, 5, 80131, Naples, Italy
| | - Simona Damiano
- †Department of Neuroscience, Unit of Physiology, University of Naples “Federico II,”Via S. Pansini, 5, 80131, Naples, Italy
| | - Gianfranco Matrone
- †Department of Neuroscience, Unit of Physiology, University of Naples “Federico II,”Via S. Pansini, 5, 80131, Naples, Italy
| | | | - Paolo Mondola
- †Department of Neuroscience, Unit of Physiology, University of Naples “Federico II,”Via S. Pansini, 5, 80131, Naples, Italy
| |
Collapse
|
50
|
Clark AR, Dean JLE, Saklatvala J. Post-transcriptional regulation of gene expression by mitogen-activated protein kinase p38. FEBS Lett 2003; 546:37-44. [PMID: 12829234 DOI: 10.1016/s0014-5793(03)00439-3] [Citation(s) in RCA: 161] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The mitogen-activated protein kinase p38 pathway was originally identified as a signalling cascade activated by pro-inflammatory stimuli and cellular stresses, and playing a critical role in the translational regulation of pro-inflammatory cytokine synthesis. In almost a decade since this discovery, a great deal has been learned about the role of the p38 pathway in the post-transcriptional regulation of pro-inflammatory gene expression. However, important questions remain to be answered concerning the specificity and mechanism or mechanisms of action of p38. This review describes recent progress and remaining puzzles in the field of post-transcriptional regulation by p38.
Collapse
Affiliation(s)
- Andrew R Clark
- Kennedy Institute of Rheumatology Division, Faculty of Medicine, Imperial College London, 1 Aspenlea Road, Hammersmith, London W6 8LH, UK.
| | | | | |
Collapse
|