1
|
Haslem L, Hays JM, Hays FA. p66Shc in Cardiovascular Pathology. Cells 2022; 11:cells11111855. [PMID: 35681549 PMCID: PMC9180016 DOI: 10.3390/cells11111855] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 05/30/2022] [Accepted: 06/01/2022] [Indexed: 02/06/2023] Open
Abstract
p66Shc is a widely expressed protein that governs a variety of cardiovascular pathologies by generating, and exacerbating, pro-apoptotic ROS signals. Here, we review p66Shc’s connections to reactive oxygen species, expression, localization, and discuss p66Shc signaling and mitochondrial functions. Emphasis is placed on recent p66Shc mitochondrial function discoveries including structure/function relationships, ROS identity and regulation, mechanistic insights, and how p66Shc-cyt c interactions can influence p66Shc mitochondrial function. Based on recent findings, a new p66Shc mitochondrial function model is also put forth wherein p66Shc acts as a rheostat that can promote or antagonize apoptosis. A discussion of how the revised p66Shc model fits previous findings in p66Shc-mediated cardiovascular pathology follows.
Collapse
Affiliation(s)
- Landon Haslem
- Biochemistry and Molecular Biology Department, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (L.H.); (J.M.H.)
| | - Jennifer M. Hays
- Biochemistry and Molecular Biology Department, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (L.H.); (J.M.H.)
| | - Franklin A. Hays
- Biochemistry and Molecular Biology Department, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (L.H.); (J.M.H.)
- Stephenson Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- Correspondence:
| |
Collapse
|
2
|
Jo S, Jung YS, Cho YR, Seo JW, Lim WC, Nam TG, Lim TG, Byun S. Oral Administration of Rosa gallica Prevents UVB-Induced Skin Aging through Targeting the c-Raf Signaling Axis. Antioxidants (Basel) 2021; 10:antiox10111663. [PMID: 34829534 PMCID: PMC8614869 DOI: 10.3390/antiox10111663] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 10/15/2021] [Accepted: 10/19/2021] [Indexed: 12/05/2022] Open
Abstract
Rosa gallica is a widely used Rosa species for medicinal and culinary purposes. Rosa gallica has been reported to display antioxidant, anti−inflammatory, and antibacterial activities. However, the effect of Rosa gallica against skin aging in vivo is unknown and its active components have not been fully understood. Oral administration of Rosa gallica prevented UVB−mediated skin wrinkle formation and loss of collagen/keratin fibers in the dorsal skin of mice. Examination of biomarkers at the molecular level showed that Rosa gallica downregulates UVB−induced COX−2 and MMP−1 expression in the skin. Through a direct comparison of major compounds identified using the UHPLC−MS/MS system, we discovered gallic acid as the primary component contributing to the anti-skin aging effect exhibited by Rosa gallica. Examination of the molecular mechanism revealed that gallic acid can potently and selectively target the c−Raf/MEK/ERK/c−Fos signaling axis. In addition, both gallic acid and MEK inhibitor blocked UVB−induced MMP−1 expression and restored collagen levels in a reconstructed 3D human skin model. Collectively, Rosa gallica could be used as a functional ingredient in the development of nutraceuticals against skin aging.
Collapse
Affiliation(s)
- Seongin Jo
- Department of Biotechnology, Yonsei University, Seoul 03722, Korea; (S.J.); (Y.-R.C.)
| | - Young-Sung Jung
- Korea Food Research Institute, Wanju-gun 55365, Korea; (Y.-S.J.); (W.-C.L.)
| | - Ye-Ryeong Cho
- Department of Biotechnology, Yonsei University, Seoul 03722, Korea; (S.J.); (Y.-R.C.)
| | - Ji-Won Seo
- Department of Agricultural Biotechnology and Research, Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Korea;
| | - Won-Chul Lim
- Korea Food Research Institute, Wanju-gun 55365, Korea; (Y.-S.J.); (W.-C.L.)
| | - Tae-Gyu Nam
- Major of Food Science and Biotechnology, Division of Bio-Convergence, Kyonggi University, Suwon 16227, Korea;
| | - Tae-Gyu Lim
- Korea Food Research Institute, Wanju-gun 55365, Korea; (Y.-S.J.); (W.-C.L.)
- Department of Food Science & Biotechnology, Sejong University, Seoul 05006, Korea
- Correspondence: (T.-G.L.); (S.B.); Tel.: +82-2-3408-3260 (T.-G.L.); +82-2-2123-5896 (S.B.)
| | - Sanguine Byun
- Department of Biotechnology, Yonsei University, Seoul 03722, Korea; (S.J.); (Y.-R.C.)
- Correspondence: (T.-G.L.); (S.B.); Tel.: +82-2-3408-3260 (T.-G.L.); +82-2-2123-5896 (S.B.)
| |
Collapse
|
3
|
ERK: A Double-Edged Sword in Cancer. ERK-Dependent Apoptosis as a Potential Therapeutic Strategy for Cancer. Cells 2021; 10:cells10102509. [PMID: 34685488 PMCID: PMC8533760 DOI: 10.3390/cells10102509] [Citation(s) in RCA: 96] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Revised: 09/16/2021] [Accepted: 09/17/2021] [Indexed: 12/12/2022] Open
Abstract
The RAF/MEK/ERK signaling pathway regulates diverse cellular processes as exemplified by cell proliferation, differentiation, motility, and survival. Activation of ERK1/2 generally promotes cell proliferation, and its deregulated activity is a hallmark of many cancers. Therefore, components and regulators of the ERK pathway are considered potential therapeutic targets for cancer, and inhibitors of this pathway, including some MEK and BRAF inhibitors, are already being used in the clinic. Notably, ERK1/2 kinases also have pro-apoptotic functions under certain conditions and enhanced ERK1/2 signaling can cause tumor cell death. Although the repertoire of the compounds which mediate ERK activation and apoptosis is expanding, and various anti-cancer compounds induce ERK activation while exerting their anti-proliferative effects, the mechanisms underlying ERK1/2-mediated cell death are still vague. Recent studies highlight the importance of dual-specificity phosphatases (DUSPs) in determining the pro- versus anti-apoptotic function of ERK in cancer. In this review, we will summarize the recent major findings in understanding the role of ERK in apoptosis, focusing on the major compounds mediating ERK-dependent apoptosis. Studies that further define the molecular targets of these compounds relevant to cell death will be essential to harnessing these compounds for developing effective cancer treatments.
Collapse
|
4
|
Carazo A, Macáková K, Matoušová K, Krčmová LK, Protti M, Mladěnka P. Vitamin A Update: Forms, Sources, Kinetics, Detection, Function, Deficiency, Therapeutic Use and Toxicity. Nutrients 2021; 13:1703. [PMID: 34069881 PMCID: PMC8157347 DOI: 10.3390/nu13051703] [Citation(s) in RCA: 88] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/07/2021] [Accepted: 05/13/2021] [Indexed: 12/12/2022] Open
Abstract
Vitamin A is a group of vital micronutrients widely present in the human diet. Animal-based products are a rich source of the retinyl ester form of the vitamin, while vegetables and fruits contain carotenoids, most of which are provitamin A. Vitamin A plays a key role in the correct functioning of multiple physiological functions. The human organism can metabolize natural forms of vitamin A and provitamin A into biologically active forms (retinol, retinal, retinoic acid), which interact with multiple molecular targets, including nuclear receptors, opsin in the retina and, according to the latest research, also some enzymes. In this review, we aim to provide a complex view on the present knowledge about vitamin A ranging from its sources through its physiological functions to consequences of its deficiency and metabolic fate up to possible pharmacological administration and potential toxicity. Current analytical methods used for its detection in real samples are included as well.
Collapse
Affiliation(s)
- Alejandro Carazo
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Charles University, Akademika Heyrovského 1203, 500 05 Hradec Králové, Czech Republic;
| | - Kateřina Macáková
- Department of Pharmacognosy, Faculty of Pharmacy, Charles University, Akademika Heyrovského 1203, 500 05 Hradec Králové, Czech Republic;
| | - Kateřina Matoušová
- Department of Clinical Biochemistry and Diagnostics, University Hospital Hradec Králové, Sokolská 581, 500 05 Hradec Králové, Czech Republic; (K.M.); (L.K.K.)
| | - Lenka Kujovská Krčmová
- Department of Clinical Biochemistry and Diagnostics, University Hospital Hradec Králové, Sokolská 581, 500 05 Hradec Králové, Czech Republic; (K.M.); (L.K.K.)
- Department of Analytical Chemistry, Faculty of Pharmacy, Charles University, Akademika Heyrovského 1203, 500 05 Hradec Králové, Czech Republic
| | - Michele Protti
- The Department of Pharmacy and Biotechnology (FaBiT), Alma Mater Studiorum–University of Bologna, Via Belmeloro 6, 40126 Bologna, Italy;
| | - Přemysl Mladěnka
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Charles University, Akademika Heyrovského 1203, 500 05 Hradec Králové, Czech Republic;
| |
Collapse
|
5
|
Kim YK, Hammerling U. The mitochondrial PKCδ/retinol signal complex exerts real-time control on energy homeostasis. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1865:158614. [PMID: 31927141 PMCID: PMC7347429 DOI: 10.1016/j.bbalip.2020.158614] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 01/03/2020] [Accepted: 01/04/2020] [Indexed: 12/17/2022]
Abstract
The review focuses on the role of vitamin A (retinol) in the control of energy homeostasis, and on the manner in which certain retinoids subvert this process, leading potentially to disease. In eukaryotic cells, the pyruvate dehydrogenase complex (PDHC) is negatively regulated by four pyruvate dehydrogenase kinases (PDKs) and two antagonistically acting pyruvate dehydrogenase phosphatases (PDPs). The second isoform, PDK2, is regulated by an autonomous mitochondrial signal cascade that is anchored on protein kinase Cδ (PKCδ), where retinoids play an indispensible co-factor role. Along with its companion proteins p66Shc, cytochrome c, and vitamin A, the PKCδ/retinol complex is located in the intermembrane space of mitochondria. At this site, and in contrast to cytosolic locations, PKCδ is activated by the site-specific oxidation of its cysteine-rich activation domain (CRD) that is configured into a complex RING-finger. Oxidation involves the transfer of electrons from cysteine moieties to oxidized cytochrome c, a step catalyzed by vitamin A. The PKCδ/retinol signalosome monitors the internal cytochrome c redox state that reflects the workload of the respiratory chain. Upon sensing demands for energy PKCδ signals the PDHC to increase glucose-derived fuel flux entering the KREBS cycle. Conversely, if excessive fuel flux surpasses the capacity of the respiratory chain, threatening the release of damaging reactive oxygen species (ROS), the polarity of the cytochrome c redox system is reversed, resulting in the chemical reduction of the PKCδ CRD, restoration of the RING-finger, refolding of PKCδ into the inactive, globular form, and curtailment of PDHC output, thereby constraining the respiratory capacity within safe margins. Several retinoids, notably anhydroretinol and fenretinide, capable of displacing retinol from binding sites on PKCδ, can co-activate PKCδ signaling but, owing to their extended system of conjugated double bonds, are unable to silence PKCδ in a timely manner. Left in the ON position, PKCδ causes chronic overload of the respiratory chain leading to mitochondrial dysfunction. This review explores how defects in the PKCδ signal machinery potentially contribute to metabolic and degenerative diseases.
Collapse
Affiliation(s)
- Youn-Kyung Kim
- Food Science Department, Rutgers Center for Lipid Research and Institute of Food Nutrition and Health, Rutgers University, New Brunswick, NJ, USA
| | - Ulrich Hammerling
- Food Science Department, Rutgers Center for Lipid Research and Institute of Food Nutrition and Health, Rutgers University, New Brunswick, NJ, USA.
| |
Collapse
|
6
|
Zhang Y, Crofton EJ, Smith TES, Koshy S, Li D, Green TA. Manipulation of retinoic acid signaling in the nucleus accumbens shell alters rat emotional behavior. Behav Brain Res 2019; 376:112177. [PMID: 31449909 PMCID: PMC7359447 DOI: 10.1016/j.bbr.2019.112177] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 08/22/2019] [Accepted: 08/22/2019] [Indexed: 01/05/2023]
Abstract
Novel targets for depression and anxiety disorders are necessary for the development of more effective pharmacotherapeutics. Our previous study found that the retinoic acid (RA) signaling pathway is the signaling pathway most enhanced in the nucleus accumbens (NAc) shell, a region important for depression, anxiety, and addiction. Genetic manipulations of RA signaling in the NAc affecting addiction-related behavior prompted our study of the role of retinoic acid signaling in depression-related and anxiety-related behavior using in vivo RNA interference. Knockdown of the retinoic acid degradation enzyme cytochrome p450 family 26 subfamily b member 1 (Cyp26b1) in the nucleus accumbens shell increased depression-related behavior while decreasing anxiety-like behavior. Knockdown of the retinoic acid binding protein, cellular RA binding protein 2 (Crabp2), also increased depression-related behavior. Knockdown of another RA binding partner fatty acid binding protein 5 (Fabp5), did not alter these behaviors. These results further support the contention that RA signaling in the NAc shell can affect emotional behavior and that targeting some components of this pathway could be a promising avenue for developing novel treatments for depression and anxiety.
Collapse
Affiliation(s)
- Yafang Zhang
- Mental Health Research Group, Center for Addiction Research, Mitchell Center for Neurodegenerative Diseases, Dept. of Pharmacology and Toxicology, The University of Texas Medical Branch, Galveston, TX, USA
| | - Elizabeth J Crofton
- Mental Health Research Group, Center for Addiction Research, Mitchell Center for Neurodegenerative Diseases, Dept. of Pharmacology and Toxicology, The University of Texas Medical Branch, Galveston, TX, USA
| | - Tileena E S Smith
- Mental Health Research Group, Center for Addiction Research, Mitchell Center for Neurodegenerative Diseases, Dept. of Pharmacology and Toxicology, The University of Texas Medical Branch, Galveston, TX, USA
| | - Shyny Koshy
- Mental Health Research Group, Center for Addiction Research, Mitchell Center for Neurodegenerative Diseases, Dept. of Pharmacology and Toxicology, The University of Texas Medical Branch, Galveston, TX, USA
| | - Dingge Li
- Mental Health Research Group, Center for Addiction Research, Mitchell Center for Neurodegenerative Diseases, Dept. of Pharmacology and Toxicology, The University of Texas Medical Branch, Galveston, TX, USA
| | - Thomas A Green
- Mental Health Research Group, Center for Addiction Research, Mitchell Center for Neurodegenerative Diseases, Dept. of Pharmacology and Toxicology, The University of Texas Medical Branch, Galveston, TX, USA.
| |
Collapse
|
7
|
Ammar UM, Abdel-Maksoud MS, Oh CH. Recent advances of RAF (rapidly accelerated fibrosarcoma) inhibitors as anti-cancer agents. Eur J Med Chem 2018; 158:144-166. [PMID: 30216849 DOI: 10.1016/j.ejmech.2018.09.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 09/01/2018] [Accepted: 09/03/2018] [Indexed: 12/19/2022]
Abstract
Frequent oncogenic mutations have been identified in MAPK (mitogen-activated protein kinase) signaling pathway components. As a result, MAPK pathway is associated with human cancer initiation, in particular RAF (rapidly accelerated fibrosarcoma) component. The mutation in RAF component leads to auto-activation of MAPK signaling pathway, stimulating the uncontrolled cell growth and proliferation. In last few years, diverse chemical scaffolds have been identified as RAF inhibitors. Most of these scaffolds show potent anti-cancer activity. The present review highlights the recent investigations of RAF inhibitors during the last five years.
Collapse
Affiliation(s)
- Usama M Ammar
- Center for Biomaterials, Korea Institute of Science & Technology (KIST), Seoul, Seongbuk-gu, 02792, Republic of Korea; Department of Biomolecular Science, University of Science & Technology (UST), Daejeon, Yuseong-gu, 34113, Republic of Korea; Pharmaceutical Chemistry Department, Faculty of Pharmacy, Ahram Canadian University, Giza, 12566, Egypt
| | - Mohammed S Abdel-Maksoud
- Medicinal & Pharmaceutical Chemistry Department, Pharmaceutical and Drug Industries Research Division, National Research Centre (NRC), Dokki, Giza, 12622, Egypt
| | - Chang-Hyun Oh
- Center for Biomaterials, Korea Institute of Science & Technology (KIST), Seoul, Seongbuk-gu, 02792, Republic of Korea; Department of Biomolecular Science, University of Science & Technology (UST), Daejeon, Yuseong-gu, 34113, Republic of Korea.
| |
Collapse
|
8
|
Hammerling U. Retinol as electron carrier in redox signaling, a new frontier in vitamin A research. Hepatobiliary Surg Nutr 2016; 5:15-28. [PMID: 26904553 PMCID: PMC4739943 DOI: 10.3978/j.issn.2304-3881.2016.01.02] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 11/06/2015] [Indexed: 01/26/2023]
Abstract
Nature uses carotenoids and retinoids as chromophores for diverse energy conversion processes. The key structural feature enabling the interaction with light and other manifestations of electro-magnetism is the conjugated double-bond system that all members of this superfamily share in common. Among retinoids, retinaldehyde alone was long known as the active chromophore of vision in vertebrates and invertebrates, as well of various light-driven proton and ion pumps in Archaea. Until now, vitamin A (retinol) was solely regarded as a biochemical precursor for bioactive retinoids such as retinaldehyde and retinoic acid (RA), but recent results indicate that this compound has its own physiology. It functions as an electron carrier in mitochondria. By electronically coupling protein kinase Cδ (PCKδ) with cytochrome c, vitamin A enables the redox activation of this enzyme. This review focuses on the biochemistry and biology of the PCKδ signaling system, comprising PKCδ, the adapter protein p66Shc, cytochrome c and retinol. This complex positively regulates the conversion of pyruvate to acetyl-coenzyme A (CoA) by the pyruvate dehydrogenase enzyme. Vitamin A therefore plays a key role in glycolytic energy generation. The emerging paradigm of retinol as electron-transfer agent is potentially transformative, opening new frontiers in retinoid research.
Collapse
|
9
|
Abstract
For the past century, vitamin A has been considered to serve as a precursor for retinoids that facilitate vision or as a precursor for retinoic acid (RA), a signaling molecule that modulates gene expression. However, vitamin A circulates in plasma at levels that far exceed the amount needed for vision or the synthesis of nanomolar levels of RA, and this suggests that vitamin A alcohol (i.e. retinol) may possess additional biological activity. We have pursued this question for the last 20 years, and in this chapter, we unfold the story of our quest and the data that support a novel and distinct role for vitamin A (alcohol) action. Our current model supports direct binding of vitamin A to the activation domains of serine/threonine kinases, such as protein kinase C (PKC) and Raf isoforms, where it is involved in redox activation of these proteins. Redox activation of PKCs was first described by the founders of the PKC field, but several hurdles needed to be overcome before a detailed understanding of the biochemistry could be provided. Two discoveries moved the field forward. First, was the discovery that the PKCδ isoform was activated by cytochrome c, a protein with oxidoreduction activity in mitochondria. Second, was the revelation that both PKCδ and cytochrome c are tethered to p66Shc, an adapter protein that brings the PKC zinc-finger substrate into close proximity with its oxidizing partner. Detailed characterization of the PKCδ signalosome complex was made possible by the work of many investigators. Our contribution was determining that vitamin A is a vital co-factor required to support an unprecedented redox-activation mechanism. This unique function of vitamin A is the first example of a general system that connects the one-electron redox chemistry of a heme protein (cytochrome c) with the two-electron chemistry of a classical phosphoprotein (PKCδ). Furthermore, contributions to the regulation of mitochondrial energetics attest to biological significance of vitamin A alcohol action.
Collapse
Affiliation(s)
- Ulrich Hammerling
- Member Emeritus, Immunology Program, Sloan-Kettering Institute for Cancer Research, 10065, New York, NY, USA.
| |
Collapse
|
10
|
All-Trans Retinoic Acid Induces Proliferation, Survival, and Migration in A549 Lung Cancer Cells by Activating the ERK Signaling Pathway through a Transcription-Independent Mechanism. BIOMED RESEARCH INTERNATIONAL 2015; 2015:404368. [PMID: 26557664 PMCID: PMC4628773 DOI: 10.1155/2015/404368] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 03/02/2015] [Indexed: 12/20/2022]
Abstract
All-trans retinoic acid (ATRA) has been used as an antineoplastic because of its ability to promote proliferation, inhibition, and differentiation, primarily in leukemia; however, in other types of cancer, such as lung cancer, treatment with ATRA is restricted because not all the patients experience the same results. The ERK signaling pathway is dysregulated in cancer cells, including lung cancer, and this dysregulation promotes proliferation and cell invasion. In this study, we demonstrate that treatment with ATRA can activate the ERK signaling pathway by a transcription-independent mechanism through a signaling cascade that involves RARα and PI3K, promoting growth, survival, and migration in lung cancer cells. Until now, this mechanism was unknown in lung cancer cells. The inhibition of the ERK signaling pathway restores the beneficial effects of ATRA, reduces proliferation, increases apoptosis, and blocks the cell migration process in lung cancer cells. In conclusion, our results suggest that the combination of ATRA with ERK inhibitor in clinical trials for lung cancer is warranted.
Collapse
|
11
|
Singh M, Suman S, Shukla Y. New Enlightenment of Skin Cancer Chemoprevention through Phytochemicals: In Vitro and In Vivo Studies and the Underlying Mechanisms. BIOMED RESEARCH INTERNATIONAL 2014; 2014:243452. [PMID: 24757666 PMCID: PMC3976810 DOI: 10.1155/2014/243452] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 12/05/2013] [Accepted: 12/05/2013] [Indexed: 02/08/2023]
Abstract
Skin cancer is still a major cause of morbidity and mortality worldwide. Skin overexposure to ultraviolet irradiations, chemicals, and several viruses has a capability to cause severe skin-related disorders including immunosuppression and skin cancer. These factors act in sequence at various steps of skin carcinogenesis via initiation, promotion, and/or progression. These days cancer chemoprevention is recognized as the most hopeful and novel approach to prevent, inhibit, or reverse the processes of carcinogenesis by intervention with natural products. Phytochemicals have antioxidant, antimutagenic, anticarcinogenic, and carcinogen detoxification capabilities thereby considered as efficient chemopreventive agents. Considerable efforts have been done to identify the phytochemicals which may possibly act on one or several molecular targets that modulate cellular processes such as inflammation, immunity, cell cycle progression, and apoptosis. Till date several phytochemicals in the light of chemoprevention have been studied by using suitable skin carcinogenic in vitro and in vivo models and proven as beneficial for prevention of skin cancer. This revision presents a comprehensive knowledge and the main molecular mechanisms of actions of various phytochemicals in the chemoprevention of skin cancer.
Collapse
Affiliation(s)
- Madhulika Singh
- Proteomics Laboratory, Council of Scientific & Industrial Research, Indian Institute of Toxicology Research, P.O. Box 80, M. G. Marg, Lucknow 226001, India
| | - Shankar Suman
- Proteomics Laboratory, Council of Scientific & Industrial Research, Indian Institute of Toxicology Research, P.O. Box 80, M. G. Marg, Lucknow 226001, India
| | - Yogeshwer Shukla
- Proteomics Laboratory, Council of Scientific & Industrial Research, Indian Institute of Toxicology Research, P.O. Box 80, M. G. Marg, Lucknow 226001, India
| |
Collapse
|
12
|
El-Nassan HB. Recent progress in the identification of BRAF inhibitors as anti-cancer agents. Eur J Med Chem 2014; 72:170-205. [DOI: 10.1016/j.ejmech.2013.11.018] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Revised: 11/05/2013] [Accepted: 11/18/2013] [Indexed: 12/26/2022]
|
13
|
Bunaciu RP, Yen A. 6-Formylindolo (3,2-b)carbazole (FICZ) enhances retinoic acid (RA)-induced differentiation of HL-60 myeloblastic leukemia cells. Mol Cancer 2013; 12:39. [PMID: 23656719 PMCID: PMC3693992 DOI: 10.1186/1476-4598-12-39] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Accepted: 05/07/2013] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND The aryl hydrocarbon receptor (AhR) ligand 6-Formylindolo(3,2-b)carbazole (FICZ) has received increasing attention since its identification as an endogenous AhR ligand and a photoproduct of tryptophan. FICZ and its metabolites have been detected in human fluids. We recently reported that AhR promotes retinoic acid (RA)-induced granulocytic differentiation of HL-60 myeloblastic leukemia cells by restricting the nuclear abundance of the stem cell associated transcription factor Oct4. The standard clinical management of acute promyelocytic leukemia (APL) is differentiation induction therapy using RA. But RA is not effective for other myeloid leukemias, making the mechanism of RA-induced differentiation observed in a non-APL myeloid leukemia of interest. To our knowledge, this is the first study regarding the influence of FICZ on RA-induced differentiation in any type of leukemic blasts. METHODS Using flow cytometry and Western blotting assays, we determined the effects of FICZ on RA-induced differentiation of HL-60 human leukemia cells. All experiments were performed in triplicate. The groups RA and FICZ + RA were compared using the Paired-Samples T-Test. Western blot figures present the typical blots. RESULTS We demonstrate that FICZ enhances RA-induced differentiation, assessed by the expression of the membrane differentiation marker CD11b; cell cycle arrest; and the functional differentiation marker, inducible-oxidative metabolism. FICZ causes changes in signaling events that are known to drive differentiation, and notably augments the RA-induced sustained activation of the RAF/MEK/ERK axis of the mitogen-activated protein kinase (MAPK) cascade. FICZ also augments expression of the known MAPK signaling regulatory molecules c-Cbl, VAV1, pY458 p85 PI3K, Src-family kinases (SFKs), and IRF-1, a transcription factor associated with this putative signalsome that promotes RA-induced differentiation. Moreover, FICZ in combination with RA also increases expression of AhR and even more so of both Cyp1A2 and p47phox, which are known to be transcriptionally regulated by AhR. pY1021 PDGFRβ, a marker associated with retinoic acid syndrome was also increased. CONCLUSIONS Our data suggest that FICZ modulates intracellular signaling pathways and enhances RA-induced differentiation.
Collapse
Affiliation(s)
- Rodica P Bunaciu
- Department of Biomedical Sciences, Cornell University, Ithaca, NY 14853, USA
| | | |
Collapse
|
14
|
Kang NJ, Jung SK, Lee KW, Lee HJ. Myricetin is a potent chemopreventive phytochemical in skin carcinogenesis. Ann N Y Acad Sci 2011; 1229:124-32. [PMID: 21793847 DOI: 10.1111/j.1749-6632.2011.06122.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Myricetin is a widely distributed flavonol that is found in many plants, including tea, berries, fruits, vegetables, and medicinal herbs. Abundant sources provide interesting insights into the multiple mechanisms by which myricetin mediates chemopreventive effects on skin cancer. Myricetin strongly inhibited tumor promoter-induced neoplastic cell transformation by inhibiting MEK, JAK1, Akt, and MKK4 kinase activity directly. In a mouse skin model, myricetin attenuated the ultraviolet B (UVB)-induced COX-2 expression and skin tumor formation by regulating Fyn. Myricetin-mediated inactivation of Akt in the UVB response plays a role in regulating UVB-induced carcinogenesis. Recently, myricetin was found to inhibit UVB-induced angiogenesis by targeting PI3-K in an SKH-1 hairless mouse skin tumorigenesis model. Raf kinase is a critical target for myricetin in inhibiting the UVB-induced formation of wrinkles and suppression of type I procollagen and collagen levels in mouse skin. Accumulated data suggest that myricetin acts as a promising agent for the chemoprevention of skin cancer.
Collapse
Affiliation(s)
- Nam Joo Kang
- School of Food Science and Biotechnology, Kyungpook National University, Daegu, Republic of Korea
| | | | | | | |
Collapse
|
15
|
Brigelius-Flohé R, Flohé L. Basic principles and emerging concepts in the redox control of transcription factors. Antioxid Redox Signal 2011; 15:2335-81. [PMID: 21194351 PMCID: PMC3166203 DOI: 10.1089/ars.2010.3534] [Citation(s) in RCA: 416] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Convincing concepts of redox control of gene transcription have been worked out for prokaryotes and lower eukaryotes, whereas the knowledge on complex mammalian systems still resembles a patchwork of poorly connected findings. The article, therefore, reviews principles of redox regulation with special emphasis on chemical feasibility, kinetic requirements, specificity, and physiological context, taking well investigated mammalian transcription factor systems, nuclear transcription factor of bone marrow-derived lymphocytes (NF-κB), and kelch-like ECH-associated protein-1 (Keap1)/Nrf2, as paradigms. Major conclusions are that (i) direct signaling by free radicals is restricted to O(2)•- and •NO and can be excluded for fast reacting radicals such as •OH, •OR, or Cl•; (ii) oxidant signals are H(2)O(2), enzymatically generated lipid hydroperoxides, and peroxynitrite; (iii) free radical damage is sensed via generation of Michael acceptors; (iv) protein thiol oxidation/alkylation is the prominent mechanism to modulate function; (v) redox sensors must be thiol peroxidases by themselves or proteins with similarly reactive cysteine or selenocysteine (Sec) residues to kinetically compete with glutathione peroxidase (GPx)- and peroxiredoxin (Prx)-type peroxidases or glutathione-S-transferases, respectively, a postulate that still has to be verified for putative mammalian sensors. S-transferases and Prxs are considered for system complementation. The impact of NF-κB and Nrf2 on hormesis, management of inflammatory diseases, and cancer prevention is critically discussed.
Collapse
Affiliation(s)
- Regina Brigelius-Flohé
- Department Biochemistry of Micronutrients, German Institute of Human Nutrition Potsdam-Rehbruecke, Arthur-Scheunert-Allee 114-116, Nuthetal, Germany.
| | | |
Collapse
|
16
|
|
17
|
Hiding in plain sight: uncovering a new function of vitamin A in redox signaling. Biochim Biophys Acta Mol Cell Biol Lipids 2011; 1821:241-7. [PMID: 21763457 DOI: 10.1016/j.bbalip.2011.06.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 05/27/2011] [Accepted: 06/15/2011] [Indexed: 01/05/2023]
Abstract
The protein kinase Cδ signalosome modulates the generation of acetyl-Coenzyme A from glycolytic sources. This module is composed of four interlinked components: PKCδ, the signal adapter p66Shc, cytochrome c, and vitamin A. It resides in the intermembrane space of mitochondria, and is at the center of a feedback loop that senses upstream the redox balance between oxidized and reduced cytochrome c as a measure of the workload of the respiratory chain, and transmits a forward signal to the pyruvate dehydrogenase complex to adjust the flux of fuel entering the tricarboxylic acid cycle. The novel role of vitamin A as co-activator and potential electron carrier, required for redox activation of PKCδ, is discussed. This article is part of a Special Issue entitled Retinoid and Lipid Metabolism.
Collapse
|
18
|
Little PJ, Bhattacharya R, Moreyra AE, Korichneva IL. Zinc and cardiovascular disease. Nutrition 2011; 26:1050-7. [PMID: 20950764 DOI: 10.1016/j.nut.2010.03.007] [Citation(s) in RCA: 138] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2010] [Revised: 03/13/2010] [Accepted: 03/13/2010] [Indexed: 02/07/2023]
Abstract
Zinc is a vital element in maintaining the normal structure and physiology of cells. The fact that it has an important role in states of cardiovascular diseases has been studied and described by several research groups. It appears to have protective effects in coronary artery disease and cardiomyopathy. Intracellular zinc plays a critical role in the redox signaling pathway, whereby certain triggers such as ischemia and infarction lead to release of zinc from proteins and cause myocardial damage. In such states, replenishing with zinc has been shown to improve cardiac function and prevent further damage. Thus, the area of zinc homeostasis is emerging in cardiovascular disease research. The goal of this report is to review the current knowledge and suggest further avenues of research.
Collapse
Affiliation(s)
- Peter J Little
- Diabetes and Cell Biology Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | | | | | | |
Collapse
|
19
|
Leonarduzzi G, Sottero B, Poli G. Targeting tissue oxidative damage by means of cell signaling modulators: The antioxidant concept revisited. Pharmacol Ther 2010; 128:336-74. [DOI: 10.1016/j.pharmthera.2010.08.003] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Accepted: 08/02/2010] [Indexed: 12/25/2022]
|
20
|
Acin-Perez R, Hoyos B, Gong J, Vinogradov V, Fischman DA, Leitges M, Borhan B, Starkov A, Manfredi G, Hammerling U. Regulation of intermediary metabolism by the PKCdelta signalosome in mitochondria. FASEB J 2010; 24:5033-42. [PMID: 20798245 DOI: 10.1096/fj.10-166934] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PKCδ has emerged as a novel regulatory molecule of oxidative phosphorylation by targeting the pyruvate dehydrogenase complex (PDHC). We showed that activation of PKCδ leads to the dephosphorylation of pyruvate dehydrogenase kinase 2 (PDK2), thereby decreasing PDK2 activity and increasing PDH activity, accelerating oxygen consumption, and augmenting ATP synthesis. However, the molecular components that mediate PKCδ signaling in mitochondria have remained elusive so far. Here, we identify for the first time a functional complex, which includes cytochrome c as the upstream driver of PKCδ, and uses the adapter protein p66Shc as a platform with vitamin A (retinol) as a fourth partner. All four components are necessary for the activation of the PKCδ signal chain. Genetic ablation of any one of the three proteins, or retinol depletion, silences signaling. Furthermore, mutations that disrupt the interaction of cytochrome c with p66Shc, of p66Shc with PKCδ, or the deletion of the retinol-binding pocket on PKCδ, attenuate signaling. In cytochrome c-deficient cells, reintroduction of cytochrome c Fe(3+) protein restores PKCδ signaling. Taken together, these results indicate that oxidation of PKCδ is key to the activation of the pathway. The PKCδ/p66Shc/cytochrome c signalosome might have evolved to effect site-directed oxidation of zinc-finger structures of PKCδ, which harbor the activation centers and the vitamin A binding sites. Our findings define the molecular mechanisms underlying the signaling function of PKCδ in mitochondria.
Collapse
Affiliation(s)
- Rebeca Acin-Perez
- Department of Neurology and Neurobiology, Weill-Cornell Medical School, New York, New York, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Acin-Perez R, Hoyos B, Gong J, Vinogradov V, Fischman DA, Leitges M, Borhan B, Starkov A, Manfredi G, Hammerling U. Regulation of intermediary metabolism by the PKCδ signalosome in mitochondria. FASEB J 2010. [DOI: 10.1096/fj.10.166934] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Rebeca Acin-Perez
- Department of Neurology and NeurobiologyWeill‐Cornell Medical School New York New York USA
| | - Beatrice Hoyos
- Immunology Program, Sloan‐Kettering Institute for Cancer Research New York New York USA
| | - Jianli Gong
- Immunology Program, Sloan‐Kettering Institute for Cancer Research New York New York USA
| | - Valerie Vinogradov
- Immunology Program, Sloan‐Kettering Institute for Cancer Research New York New York USA
| | - Donald A. Fischman
- Department of Cell and Developmental BiologyWeill‐Cornell Medical School New York New York USA
| | - Michael Leitges
- The Biotechnology Centre of Oslo, University of Oslo Oslo Norway
| | - Babak Borhan
- Department of ChemistryMichigan State University East Lansing Michigan USA
| | - Anatoly Starkov
- Department of Neurology and NeurobiologyWeill‐Cornell Medical School New York New York USA
| | - Giovanni Manfredi
- Department of Neurology and NeurobiologyWeill‐Cornell Medical School New York New York USA
| | - Ulrich Hammerling
- Department of Cell and Developmental BiologyWeill‐Cornell Medical School New York New York USA
| |
Collapse
|
22
|
Acin-Perez R, Hoyos B, Zhao F, Vinogradov V, Fischman DA, Harris RA, Leitges M, Wongsiriroj N, Blaner WS, Manfredi G, Hammerling U. Control of oxidative phosphorylation by vitamin A illuminates a fundamental role in mitochondrial energy homoeostasis. FASEB J 2010; 24:627-36. [PMID: 19812372 PMCID: PMC2812036 DOI: 10.1096/fj.09-142281] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2009] [Accepted: 09/17/2009] [Indexed: 12/31/2022]
Abstract
The physiology of two metabolites of vitamin A is understood in substantial detail: retinaldehyde functions as the universal chromophore in the vertebrate and invertebrate eye; retinoic acid regulates a set of vertebrate transcription factors, the retinoic acid receptor superfamily. The third member of this retinoid triumvirate is retinol. While functioning as the precursor of retinaldehyde and retinoic acid, a growing body of evidence suggests a far more fundamental role for retinol in signal transduction. Here we show that retinol is essential for the metabolic fitness of mitochondria. When cells were deprived of retinol, respiration and ATP synthesis defaulted to basal levels. They recovered to significantly higher energy output as soon as retinol was restored to physiological concentration, without the need for metabolic conversion to other retinoids. Retinol emerged as an essential cofactor of protein kinase Cdelta (PKCdelta), without which this enzyme failed to be activated in mitochondria. Furthermore, retinol needed to physically bind PKCdelta, because mutation of the retinol binding site rendered PKCdelta unresponsive to Rol, while retaining responsiveness to phorbol ester. The PKCdelta/retinol complex signaled the pyruvate dehydrogenase complex for enhanced flux of pyruvate into the Krebs cycle. The baseline response was reduced in vitamin A-deficient lecithin:retinol acyl transferase-knockout mice, but this was corrected within 3 h by intraperitoneal injection of vitamin A; this suggests that vitamin A is physiologically important. These results illuminate a hitherto unsuspected role of vitamin A in mitochondrial bioenergetics of mammals, acting as a nutritional sensor. As such, retinol is of fundamental importance for energy homeostasis. The data provide a mechanistic explanation to the nearly 100-yr-old question of why vitamin A deficiency causes so many pathologies that are independent of retinoic acid action.
Collapse
Affiliation(s)
- Rebeca Acin-Perez
- Department of Neurology and Neurobiology Weill-Cornell Medical School, New York, New York, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Cagnol S, Chambard JC. ERK and cell death: mechanisms of ERK-induced cell death--apoptosis, autophagy and senescence. FEBS J 2009; 277:2-21. [PMID: 19843174 DOI: 10.1111/j.1742-4658.2009.07366.x] [Citation(s) in RCA: 976] [Impact Index Per Article: 65.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The Ras/Raf/extracellular signal-regulated kinase (ERK) signaling pathway plays a crucial role in almost all cell functions and therefore requires exquisite control of its spatiotemporal activity. Depending on the cell type and stimulus, ERK activity will mediate different antiproliferative events, such as apoptosis, autophagy and senescence in vitro and in vivo. ERK activity can promote either intrinsic or extrinsic apoptotic pathways by induction of mitochondrial cytochrome c release or caspase-8 activation, permanent cell cycle arrest or autophagic vacuolization. These unusual effects require sustained ERK activity in specific subcellular compartments and could depend on the presence of reactive oxygen species. We will summarize the mechanisms involved in Ras/Raf/ERK antiproliferative functions.
Collapse
Affiliation(s)
- Sebastien Cagnol
- Department of Anatomy and Cellular Biology, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, Quebec, Canada.
| | | |
Collapse
|
24
|
Chiu HJ, Fischman DA, Hammerling U. Vitamin A depletion causes oxidative stress, mitochondrial dysfunction, and PARP-1-dependent energy deprivation. FASEB J 2008; 22:3878-87. [PMID: 18676402 DOI: 10.1096/fj.08-112375] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A significant unresolved question is how vitamin A deprivation causes, and why retinoic acid fails to reverse, immunodeficiency. When depleted of vitamin A, T cells undergo programmed cell death (PCD), which is enhanced by the natural competitor of retinol, anhydroretinol. PCD does not happen by apoptosis, despite the occurrence of shared early events, including mitochondrial membrane depolarization, permeability transition pore opening, and cytochrome c release. It also lacks caspase-3 activation, chromatin condensation, and endonuclease-mediated DNA degradation, hallmarks of apoptosis. PCD following vitamin A deprivation exhibits increased production of reactive oxygen species (ROS), drastic reductions in ATP and NAD(+) levels, and activation of poly-(ADP-ribose) polymerase (PARP) -1. These latter steps are causative because neutralizing ROS, imposing hypoxic conditions, or inhibiting PARP-1 by genetic or pharmacologic approaches prevents energy depletion and PCD. The data highlight a novel regulatory role of vitamin A in mitochondrial energy homeostasis.
Collapse
Affiliation(s)
- Haw-Jyh Chiu
- Ulrich Hammerling, Memorial Sloan-Kettering Cancer Center, Immunology Program, 1275 York Ave., New York, NY 10065, USA
| | | | | |
Collapse
|
25
|
Wilhelm J, Smistík Z, Mahelková G, Vytásek R. Redox regulation of proliferation of lens epithelial cells in culture. Cell Biochem Funct 2007; 25:317-21. [PMID: 17191273 DOI: 10.1002/cbf.1390] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Both oxidants and antioxidants have been shown to modulate cell proliferation. We studied the effects of hydrogen peroxide and two antioxidants on the rate of proliferation of lens epithelial cells in culture. Hydrogen peroxide at concentrations higher than 32 microM caused a significant inhibition of proliferation. However, in the concentration range of 0.01-0.5 microM, hydrogen peroxide stimulated the rate of proliferation. The effect of hydrogen peroxide was dependent on the amount of cells in an individual culture well, indicating decomposition of hydrogen peroxide by cellular enzymes. In order to eliminate the possibility of decomposition of the dose of hydrogen peroxide given as a bolus, we induced continual production of hydrogen peroxide by adding glucose oxidase to the incubation medium. We found that hydrogen peroxide, generated by 1-50 microU x ml(-1) of glucose oxidase significantly increased the rate of cell proliferation. This effect was most apparent at the beginning of the exponential phase of cellular growth. Glucose oxidase alone (100-500 microU x ml(-1)) did not produce any effect. The effects of pro-oxidative hydrogen peroxide were compared with the effects of two biologically important antioxidants, alpha-tocopherol and retinol. Both antioxidants completely inhibited proliferation at concentrations of 30 microM and higher. In contrast to retinol, the effect of alpha-tocopherol was dependent on the amount of cells, indicating cellular decomposition of alpha-tocopherol. The results document the possibility of redox regulation of cellular proliferation at physiologically relevant reactant concentrations.
Collapse
Affiliation(s)
- J Wilhelm
- Department of Medical Chemistry and Biochemistry, 2nd Medical School, Charles University and Center for Experimental Cardiovascular Research, Prague, Czech Republic.
| | | | | | | |
Collapse
|
26
|
Altucci L, Leibowitz MD, Ogilvie KM, de Lera AR, Gronemeyer H. RAR and RXR modulation in cancer and metabolic disease. Nat Rev Drug Discov 2007; 6:793-810. [PMID: 17906642 DOI: 10.1038/nrd2397] [Citation(s) in RCA: 397] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Retinoic acid receptors (RARs) are ligand-controlled transcription factors that function as heterodimers with retinoid X receptors (RXRs) to regulate cell growth and survival. The success of RAR modulation in the treatment of acute promyelocytic leukaemia (APL) has stimulated considerable interest in the development of RAR and RXR modulators. This has been aided by recent advances in the understanding of the biological role of RARs and RXRs and in the design of selective receptor modulators that might overcome the limitations of current drugs. Here, we discuss the challenges and opportunities for therapeutic strategies based on RXR and RAR modulators, with a focus on cancer and metabolic diseases such as diabetes and obesity.
Collapse
Affiliation(s)
- Lucia Altucci
- Dipartimento di Patologia Generale, Seconda Università degli Studi di Napoli, Vico Luigi de Crecchio 7, 80138 Napoli, Italy
| | | | | | | | | |
Collapse
|
27
|
Genestra M. Oxyl radicals, redox-sensitive signalling cascades and antioxidants. Cell Signal 2007; 19:1807-19. [PMID: 17570640 DOI: 10.1016/j.cellsig.2007.04.009] [Citation(s) in RCA: 361] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2007] [Accepted: 04/23/2007] [Indexed: 01/20/2023]
Abstract
Oxidative stress is an increase in the reduction potential or a large decrease in the reducing capacity of the cellular redox couples. A particularly destructive aspect of oxidative stress is the production of reactive oxygen species (ROS), which include free radicals and peroxides. Some of the less reactive of these species can be converted by oxidoreduction reactions with transition metals into more aggressive radical species that can cause extensive cellular damage. In animals, ROS may influence cell proliferation, cell death (either apoptosis or necrosis) and the expression of genes, and may be involved in the activation of several signalling pathways, activating cell signalling cascades, such as those involving mitogen-activated protein kinases. Most of these oxygen-derived species are produced at a low level by normal aerobic metabolism and the damage they cause to cells is constantly repaired. The cellular redox environment is preserved by enzymes and antioxidants that maintain the reduced state through a constant input of metabolic energy. This review summarizes current studies that have been regarding the production of ROS and the general redox-sensitive targets of cell signalling cascades.
Collapse
Affiliation(s)
- Marcelo Genestra
- Department of Immunology, Oswaldo Cruz Institute/FIOCRUZ, Avenida Brasil, 4365-Manguinhos, Rio de Janeiro, CEP 21045-900, RJ-Brazil.
| |
Collapse
|
28
|
Fu PP, Xia Q, Boudreau MD, Howard PC, Tolleson WH, Wamer WG. Physiological Role of Retinyl Palmitate in the Skin. VITAMIN A 2007; 75:223-56. [PMID: 17368318 DOI: 10.1016/s0083-6729(06)75009-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The skin is similar to other organs in how it absorbs, stores, and metabolizes vitamin A. However, because of the anatomical location of skin and the specialized physiological roles it plays, there are ways in which the skin is rather unique. The stratified structure of the epidermis results from the orchestration of retinoid-influenced cellular division and differentiation. Similarly, many of the physiological responses of the skin, such as dermal aging, immune defense, and wound healing, are significantly affected by retinoids. While much is known about the molecular events through which retinoids affect the skin's responses, more remains to be learned. Interest in the effects of retinol, retinyl palmitate, and other retinoids on the skin, fueled in part by the promise of improved dermatologic and cosmetic products, will undoubtedly make the effects of retinoids on skin a subject for continued intense investigation.
Collapse
Affiliation(s)
- Peter P Fu
- National Center for Toxicological Research, Food and Drug Administration, Jefferson, Arkansas 72079, USA
| | | | | | | | | | | |
Collapse
|
29
|
Park EY, Dillard A, Williams EA, Wilder ET, Pepper MR, Lane MA. Retinol inhibits the growth of all-trans-retinoic acid-sensitive and all-trans-retinoic acid-resistant colon cancer cells through a retinoic acid receptor-independent mechanism. Cancer Res 2005; 65:9923-33. [PMID: 16267017 DOI: 10.1158/0008-5472.can-05-1604] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Retinol (vitamin A) is thought to exert its effects through the actions of its metabolite, all-trans-retinoic acid (ATRA), on gene transcription mediated by retinoic acid receptors (RAR) and retinoic acid response elements (RARE). However, retinoic acid resistance limits the chemotherapeutic potential of ATRA. We examined the ability of retinol to inhibit the growth of ATRA-sensitive (HCT-15) and ATRA-resistant (HCT-116, SW620, and WiDR) human colon cancer cell lines. Retinol inhibited cell growth in a dose-responsive manner. Retinol was not metabolized to ATRA or any bioactive retinoid in two of the cell lines examined. HCT-116 and WiDR cells converted a small amount of retinol to ATRA; however, this amount of ATRA was unable to inhibit cell growth. To show that retinol was not inducing RARE-mediated transcription, each cell line was transfected with pRARE-chloramphenicol acetyltransferase (CAT) and treated with ATRA and retinol. Although treatment with ATRA increased CAT activity 5-fold in ATRA-sensitive cells, retinol treatment did not increase CAT activity in any cell line examined. To show that growth inhibition due to retinol was ATRA, RAR, and RARE independent, a pan-RAR antagonist was used to block RAR signaling. Retinol-induced growth inhibition was not alleviated by the RAR antagonist in any cell line, but the antagonist alleviated ATRA-induced growth inhibition of HCT-15 cells. Retinol did not induce apoptosis, differentiation or necrosis, but affected cell cycle progression. Our data show that retinol acts through a novel, RAR-independent mechanism to inhibit colon cancer cell growth.
Collapse
Affiliation(s)
- Eun Young Park
- Institute for Cell and Molecular Biology and Division of Nutritional Sciences, Department of Human Ecology, University of Texas at Austin, Austin, Texas 78712, USA
| | | | | | | | | | | |
Collapse
|
30
|
Rogge B, Itagaki Y, Fishkin N, Levi E, Rühl R, Yi SS, Nakanishi K, Hammerling U. Retinoylserine and retinoylalanine, natural products of the moth Trichoplusia ni. JOURNAL OF NATURAL PRODUCTS 2005; 68:1536-40. [PMID: 16252921 PMCID: PMC2532592 DOI: 10.1021/np0496791] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Insect cells convert vitamin A into a number of retinoids that are evolutionarily conserved with those of mammalian cells. However, insect cells also produce additional natural retinoids. Namely, two retinoic acid peptides, N-trans-retinoylserine (1) and N-trans-retinoylalanine (2), have been isolated from a cell line of the common cabbage looper, Trichoplusia ni. These are the first examples of naturally occurring retinoic acid linked to amino acids through an amide bond; the amino acid moieties are depicted in the more common l-configuration, although the absolute configuration was not determined due to the minuscule sample amount.
Collapse
Affiliation(s)
- Barbara Rogge
- Immunology Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA
| | | | | | | | | | | | | | | |
Collapse
|
31
|
Beeram M, Patnaik A, Rowinsky EK. Raf: A Strategic Target for Therapeutic Development Against Cancer. J Clin Oncol 2005; 23:6771-90. [PMID: 16170185 DOI: 10.1200/jco.2005.08.036] [Citation(s) in RCA: 199] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The mitogen-activated protein kinase (MAPK) signaling pathway plays a critical role in transmitting proliferative signals generated by cell surface receptors and cytoplasmic signaling elements to the nucleus. Several important signaling elements of the MAPK pathway, particularly Ras and Raf, are encoded by oncogenes, and as such, their structures and functions can be modified, rendering them constitutively active. Because the MAPK pathway is dysregulated in a notable proportion of human malignancies, many of its aberrant and critical components represent strategic targets for therapeutic development against cancer. Raf, which is an essential serine/threonine kinase constituent of the MAPK pathway and a downstream effector of the central signal transduction mediator Ras, is activated in a wide range of human malignancies by aberrant signaling upstream of the protein (eg, growth factor receptors and mutant Ras) and activating mutations of the protein itself, both of which confer a proliferative advantage. Three isoforms of Raf have been identified, and therapeutics targeting Raf, including small-molecule inhibitors and antisense oligodeoxyribonucleotides (ASON), are undergoing clinical evaluation. The outcomes of these investigations may have far-reaching implications in the management of many types of human cancer. This review outlines the structure and diverse functions of Raf, the rationale for targeting Raf as a therapeutic strategy against cancer, and the present status of various therapeutic approaches including ASONs and small molecules, particularly sorafenib (BAY 43-9006).
Collapse
Affiliation(s)
- Muralidhar Beeram
- University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | | | | |
Collapse
|
32
|
Lefebvre P, Martin PJ, Flajollet S, Dedieu S, Billaut X, Lefebvre B. Transcriptional activities of retinoic acid receptors. VITAMINS AND HORMONES 2005; 70:199-264. [PMID: 15727806 DOI: 10.1016/s0083-6729(05)70007-8] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Vitamin A derivatives plays a crucial role in embryonic development, as demonstrated by the teratogenic effect of either an excess or a deficiency in vitamin A. Retinoid effects extend however beyond embryonic development, and tissue homeostasis, lipid metabolism, cellular differentiation and proliferation are in part controlled through the retinoid signaling pathway. Retinoids are also therapeutically effective in the treatment of skin diseases (acne, psoriasis and photoaging) and of some cancers. Most of these effects are the consequences of retinoic acid receptors activation, which triggers transcriptional events leading either to transcriptional activation or repression of retinoid-controlled genes. Synthetic molecules are able to mimic part of the biological effects of the natural retinoic acid receptors, all-trans retinoic acid. Therefore, retinoic acid receptors are considered as highly valuable therapeutic targets and limiting unwanted secondary effects due to retinoid treatment requires a molecular knowledge of retinoic acid receptors biology. In this review, we will examine experimental evidence which provide a molecular basis for the pleiotropic effects of retinoids, and emphasize the crucial roles of coregulators of retinoic acid receptors, providing a conceptual framework to identify novel therapeutic targets.
Collapse
Affiliation(s)
- Philippe Lefebvre
- INSERM U459 and Ligue Nationale Contre le Cancer, Faculté de Médecine de Lille, 59045 Lille cedex, France
| | | | | | | | | | | |
Collapse
|
33
|
Haney CJ, Grass G, Franke S, Rensing C. New developments in the understanding of the cation diffusion facilitator family. J Ind Microbiol Biotechnol 2005; 32:215-26. [PMID: 15889311 DOI: 10.1007/s10295-005-0224-3] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2004] [Accepted: 03/19/2005] [Indexed: 11/28/2022]
Abstract
Cation diffusion facilitator (CDF) proteins are a phylogenetically ubiquitous family of intermembrane transporters generally believed to play a role in the homeostasis of a wide range divalent metal cations. CDFs are found in a host of membranes, including the bacterial cell membrane, the vacuolar membrane of both plants and yeast, and the golgi apparatus of animals. As such, they are potentially useful in the engineering of hyperaccumulative phytoremediation systems. While not yet sufficient for reliable biotechnological manipulation, characterization of this family is proceeding briskly. Experimental data suggests that CDFs are generally homodimers that use proton antiport to drive substrate translocation across a membrane. This translocation of both substrate and protons is likely mediated by a combination of histidines, aspartates, and glutamates. Functional data has suggested that CDFs are not limited to metal homeostasis roles, as some appear to be determinants in the operation of high-volume metal resistance systems, and others may facilitate cation-donation as a means of signal transduction. This review seeks to give an overview of the data prompting these conclusions, while presenting additional data whose interpretation is still contentious.
Collapse
Affiliation(s)
- Christopher J Haney
- Department of Soil, Water, and Environmental Science, University of Arizona, Shantz Bld number 38 Rm 424, Tucson, AZ 85721, USA
| | | | | | | |
Collapse
|
34
|
Hoyos B, Jiang S, Hammerling U. Location and Functional Significance of Retinol-binding Sites on the Serine/Threonine Kinase, c-Raf. J Biol Chem 2005; 280:6872-8. [PMID: 15591313 DOI: 10.1074/jbc.m412695200] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Redox activations of serine/threonine kinases represent alternate pathways in which vitamin A plays a crucial co-factor role. Vitamin A binds the zinc finger domain of c-Raf with nanomolar affinity. The retinoid-binding site has been mapped within this structure by scanning mutagenesis. The deduced contact sites were found anchored on Phe-8, counting from the 1st conserved histidine of the zinc finger. These sites agreed with contact amino acids identified by computational docking. The boundaries of a related binding pocket were identified by mutagenesis and partially confirmed by docking trials in the protein kinase C-alpha C1A zinc finger. They comprised Phe-7, Phe-8, and Trp-22. This trio was absent from the alphaC1B domain, explaining why the latter did not bind retinol. Reconfiguring at a minimum the two corresponding amino acids of alphaC1B, Thr-7 and Tyr-22, to conform to alphaC1A converted this domain to a binder. Deletion of the predicted retinoid-binding site in the full-length molecule created a mutant c-Raf that was deficient in retinol-dependent redox activation but fully responsive to epidermal growth factor. Our findings indicate that ligation of retinol to a specific site embedded in the regulatory domain is an important feature of c-Raf regulation in the redox pathway.
Collapse
Affiliation(s)
- Beatrice Hoyos
- Immunology Program, Memorial Sloan Kettering Cancer, New York, New York, 10021, USA.
| | | | | |
Collapse
|
35
|
Kang J, Chen J, Shi Y, Jia J, Wang Z. Histone hypoacetylation is involved in 1,10-phenanthroline?Cu2+-induced human hepatoma cell apoptosis. J Biol Inorg Chem 2005; 10:190-8. [PMID: 15818509 DOI: 10.1007/s00775-004-0623-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2004] [Accepted: 12/21/2004] [Indexed: 10/25/2022]
Abstract
The 1,10-orthophenanthroline (OP)-Cu(2+) combination, one generally used reactive oxygen species (ROS) generation system, is known to induce cell apoptosis, but the mechanism of ROS generation in this process remains unclear. Here we found that in the presence of 5 microM Cu(2+), OP inhibited histone acetyltransferase (HAT) activity, resulting in decreased acetylation in both histone H3 and H4. This inhibition of histone acetylation and HAT activity was significantly attenuated by preventing or scavenging ROS generation with the Cu(2+) chelator of bathocuproine disulfonate, or the antioxidants of N-acetyl-cysteine and mannitol, respectively, indicating the involvement of ROS generation in OP-Cu(2+) -induced histone hypoacetylation. At the same time, this ROS generation is found to be involved in OP-Cu(2+) -induced apoptosis in human hepatoma Hep3B cells. The important role of histone hypoacetylation in the induction of apoptosis was also proven by the marked diminution of apoptosis by 100 nM trichostatin A, a specific inhibitor of histone deacetylase, or the overexpression of p300, an HAT protein. Collectively, these observations suggest that histone hypoacetylation represents one unrevealed mechanism involved in the in vivo function of OP-Cu(2+) -generated ROS, at least in their induction of cell apoptosis.
Collapse
Affiliation(s)
- Jiuhong Kang
- School of Life Science, Lanzhou University, China.
| | | | | | | | | |
Collapse
|
36
|
Abstract
Thiol-disulfide interconversions play a crucial role in the chemistry of biological systems. They participate in the major systems that control the cellular redox potential and prevent oxidative damage. In addition, thiol-disulfide exchange reactions serve as molecular switches in a growing number of redox-regulated proteins. We developed a differential thiol-trapping technique combined with two-dimensional gel analysis, which in combination with genetic studies, allowed us to obtain a snapshot of the in vivo thiol status of cellular proteins. We determined the redox potential of protein thiols in vivo, identified and dissected the in vivo substrate proteins of the major cellular thiol-disulfide oxidoreductases, and discovered proteins that undergo thiol modifications during oxidative stress. Under normal growth conditions most cytosolic proteins had reduced cysteines, confirming existing dogmas. Among the few partly oxidized cytosolic proteins that we detected were proteins that are known to form disulfide bond intermediates transiently during their catalytic cycle (e.g., dihydrolipoyl transacetylase and lipoamide dehydrogenase). Most proteins with highly oxidized thiols were periplasmic proteins and were found to be in vivo substrates of the disulfide-bond-forming protein DsbA. We discovered a substantial number of redox-sensitive cytoplasmic proteins, whose thiol groups were significantly oxidized in strains lacking thioredoxin A. These included detoxifying enzymes as well as many metabolic enzymes with active-site cysteines that were not known to be substrates for thioredoxin. H2O2-induced oxidative stress resulted in the specific oxidation of thiols of proteins involved in detoxification of H2O2 and of enzymes of cofactor and amino acid biosynthesis pathways such as thiolperoxidase, GTP-cyclohydrolase I, and the cobalamin-independent methionine synthase MetE. Remarkably, a number of these proteins were previously or are now shown to be redox regulated. A differential thiol-trapping technique combined with two- dimensional gel analysis has been developed and used to visualize thiol-disulfide exchange reactions, which act as switches in redox-regulated proteins
Collapse
Affiliation(s)
- Lars I Leichert
- 1Department of Molecular, Cellular, and Developmental Biology, University of MichiganAnn Arbor, MichiganUnited States of America
| | - Ursula Jakob
- 1Department of Molecular, Cellular, and Developmental Biology, University of MichiganAnn Arbor, MichiganUnited States of America
| |
Collapse
|
37
|
Smit N, Vicanova J, Cramers P, Vrolijk H, Pavel S. The Combined Effects of Extracts Containing Carotenoids and Vitamins E and C on Growth and Pigmentation of Cultured Human Melanocytes. Skin Pharmacol Physiol 2004; 17:238-45. [PMID: 15452410 DOI: 10.1159/000080217] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2003] [Accepted: 05/11/2004] [Indexed: 11/19/2022]
Abstract
In the present study, we investigated the effects of tomato extract (TE) containing lycopene and palm fruit extract (PE) rich in carotenoids on the growth and pigmentation of melanocyte cultures of Caucasian origin. The extracts were tested at different concentrations and in combination with vitamins E and C. Melanocytes with basic and increased (tyrosine-induced) pigmentation were treated in short-term and long-term experiments. Prevention of UVA-induced DNA damage was studied by using the comet assay. Melanocytes with stimulated melanin production showed reduced growth. Incubation of the cells with TE/PE (20/4 microg/ml) in combination with 35 microM vitamin E and 100 microM vitamin C (COMB 20/4) reduced this growth inhibition, especially in the long-term cultures. Increased production of melanin pigment was obtained when the cells were treated with 2.5 x and 10 x higher concentrations of the TE/PE and the same concentration of vitamins E and C (COMB 50/10 and 200/40). Reduced DNA damage was found after UVA irradiation in cells preincubated with COMB 50/10. The results indicate that the presence of carotenoids from TE and PE in combination with vitamins E and C may influence growth and pigmentation in melanocyte monocultures. Depending on the concentration of the carotenoid mixtures, their presence may provide some protection against the melanogenic intermediates and/or exogenous DNA damage.
Collapse
Affiliation(s)
- N Smit
- Department of Clinical Chemistry, Leiden University Medical Centre, Leiden, The Netherlands.
| | | | | | | | | |
Collapse
|
38
|
Chang TS, Jeong W, Lee DY, Cho CS, Rhee SG. The RING-H2-finger protein APC11 as a target of hydrogen peroxide. Free Radic Biol Med 2004; 37:521-30. [PMID: 15256223 DOI: 10.1016/j.freeradbiomed.2004.05.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2003] [Revised: 04/30/2004] [Accepted: 05/07/2004] [Indexed: 12/18/2022]
Abstract
The anaphase-promoting complex (APC) is a ubiquitin-protein ligase (E3) that targets cell cycle regulators such as cyclin B and securin for degradation. The APC11 subunit functions as the catalytic core of this complex and mediates the transfer of ubiquitin from a ubiquitin-conjugating enzyme (E2) to the substrate. APC11 contains a RING-H2-finger domain, which includes one histidine and seven cysteine residues that coordinate two Zn(2+) ions. We now show that exposure of purified APC11 to H(2)O(2) (0.1 to 1 mM) induced the release of bound zinc as a result of the oxidation of cysteine residues. It also impaired the physical interaction between APC11 and the E2 enzyme Ubc4 as well as inhibited the ubiquitination of cyclin B1 by APC11. The release of HeLa cells from metaphase arrest in the presence of exogenous H(2)O(2) inhibited the ubiquitination of cyclin B1 as well as the degradation of cyclin B1 and securin that were apparent in the absence of H(2)O(2). The presence of H(2)O(2) also blocked the co-immunoprecipitation of Ubc4 with APC11 and delayed the exit of cells from mitosis. Inhibition of APC11 function by H(2)O(2) thus likely contributes to the delay in cell cycle progression through mitosis that is characteristic of cells subjected to oxidative stress.
Collapse
Affiliation(s)
- Tong-Shin Chang
- Laboratory of Cell Signaling, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | | | | | | | | |
Collapse
|
39
|
Spencer ML, Theodosiou M, Noonan DJ. NPDC-1, a novel regulator of neuronal proliferation, is degraded by the ubiquitin/proteasome system through a PEST degradation motif. J Biol Chem 2004; 279:37069-78. [PMID: 15229225 DOI: 10.1074/jbc.m402507200] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Neural proliferation and differentiation control protein-1 (NPDC-1) is a protein expressed primarily in brain and lung and whose expression can be correlated with the regulation of cellular proliferation and differentiation. Embryonic differentiation in brain and lung has classically been linked to retinoid signaling, and we have recently characterized NPDC-1 as a regulator of retinoic acid-mediated events. Regulators of differentiation and development are themselves highly regulated and usually through multiple mechanisms. One such mechanism, protein degradation via the ubiquitin/proteasome degradation pathway, has been linked to the expression of a number of proteins involved in control of proliferation or differentiation, including cyclin D1 and E2F-1. The data presented here demonstrate that NPDC-1 is likewise degraded by the ubiquitin/proteasome system. MG-132, a proteasome inhibitor, stabilized the expression of NPDC-1 and allowed detection of ubiquitinated NPDC-1 in vivo. A PEST motif (rich in proline, glutamine, serine, and threonine) located in the carboxyl terminus of NPDC-1 was shown to target the protein for degradation. Deletion of the PEST motif increased NPDC-1 protein stability and NPDC-1 inhibitory effect on retinoic acid-mediated transcription. NPDC-1 was phosphorylated by several kinases, including extracellular signal-regulated kinase. Phosphorylation of NPDC-1 increased the in vitro rate of NPDC-1 ubiquitination. The MEK inhibitor, PD-98059, an inhibitor of extracellular signal-regulated activation, also inhibited the formation of ubiquitinated NPDC-1 in vivo. Together these results suggest that retinoic acid signaling can be modulated by the presence of NPDC-1 and that the protein level and activity of NPDC-1 can be regulated by phosphorylation-mediated proteasomal degradation.
Collapse
Affiliation(s)
- Michael L Spencer
- Department of Molecular and Cellular Biochemistry, University of Kentucky Medical Center, 800 Rose Street, Lexington, KY 40536, USA
| | | | | |
Collapse
|
40
|
Abstract
The Ras-extracellular signal-regulated kinase (ERK) cascade is a critical intracellular signaling pathway that regulates growth, survival, and differentiation. Previous work established that Ras-GTP binds to, and facilitates the activation of, the protein kinase Raf-1. Recently, it was demonstrated that the cation diffusion facilitator (CDF) proteins are involved in Ras-ERK signaling by use of a Caenorhabditis elegans genetic screen that identified suppressors of activated Ras. In the current work, we demonstrate that CDF proteins may function downstream of Ras, but upstream of Raf-1 in Xenopus oocytes. We also show that the C. elegans protein CDF-1 and its mammalian homologue ZnT-1 bind to the amino-terminal regulatory portion of Raf-1 and promote the biological and enzymatic activity of Raf-1. Furthermore, we show that Zn(2+) inhibits Raf-1 binding to ZnT-1. We propose a model in which CDF protein binding facilitates Raf-1 activation.
Collapse
Affiliation(s)
- Tanawat Jirakulaporn
- Center for Cardiovascular Research, the Department of Medicine, Washington University School of Medicine, St Louis, Missouri 63110, USA
| | | |
Collapse
|
41
|
Graf PCF, Martinez-Yamout M, VanHaerents S, Lilie H, Dyson HJ, Jakob U. Activation of the Redox-regulated Chaperone Hsp33 by Domain Unfolding. J Biol Chem 2004; 279:20529-38. [PMID: 15023991 DOI: 10.1074/jbc.m401764200] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The molecular chaperone Hsp33 in Escherichia coli responds to oxidative stress conditions with the rapid activation of its chaperone function. On its activation pathway, Hsp33 progresses through three major conformations, starting as a reduced, zinc-bound inactive monomer, proceeding through an oxidized zinc-free monomer, and ending as a fully active oxidized dimer. While it is known that Hsp33 senses oxidative stress through its C-terminal four-cysteine zinc center, the nature of the conformational changes in Hsp33 that must take place to accommodate this activation process is largely unknown. To investigate these conformational rearrangements, we constructed constitutively monomeric Hsp33 variants as well as fragments consisting of the redox regulatory C-terminal domain of Hsp33. These proteins were studied by a combination of biochemical and NMR spectroscopic techniques. We found that in the reduced, monomeric conformation, zinc binding stabilizes the C terminus of Hsp33 in a highly compact, alpha-helical structure. This appears to conceal both the substrate-binding site as well as the dimerization interface. Zinc release without formation of the two native disulfide bonds causes the partial unfolding of the C terminus of Hsp33. This is sufficient to unmask the substrate-binding site, but not the dimerization interface, rendering reduced zinc-free Hsp33 partially active yet monomeric. Critical for the dimerization is disulfide bond formation, which causes the further unfolding of the C terminus of Hsp3 and allows the association of two oxidized Hsp33 monomers. This then leads to the formation of active Hsp33 dimers, which are capable of protecting cells against the severe consequences of oxidative heat stress.
Collapse
Affiliation(s)
- Paul C F Graf
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, 830 N. University, Ann Arbor, MI 48109-1048, USA
| | | | | | | | | | | |
Collapse
|
42
|
Abe T, Oue N, Yasui W, Ryoji M. Rapid and preferential induction of ATF3 transcription in response to low doses of UVA light. Biochem Biophys Res Commun 2003; 310:1168-74. [PMID: 14559238 DOI: 10.1016/j.bbrc.2003.09.143] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Long-wavelength UV light (UVA) is known to induce transcription of various genes in the cell and to cause a variety of pathological or protective responses in the skin. To find additional UVA-responsive genes, human skin-derived fibroblasts were exposed to UVA under non- or partially lethal conditions, and the effects of UVA on the transcriptional profile were examined by using DNA microarray and RT-PCR. Transcription of several genes including those already known to be UVA-responsive was induced to a significant extent under 50% lethal conditions of exposure. Among those, ATF3 was the most sensitive and its transcription was increased 10-fold within 1h. Even at a non-lethal dose of UVA (8J/cm(2)), it was increased 8-fold, if cells were cultured for 3h post-exposure. Typical immediate-early genes such as c-fos and c-jun were not affected at this dose. We thus suggest that ATF3 could be a key regulator for a variety of cellular responses in the skin, particularly to low doses of UVA.
Collapse
Affiliation(s)
- Takaya Abe
- Laboratory of Molecular Biology, Department of Bioresources, Hiroshima Prefectural University, 562 Nanatsuka, Shobara, Hiroshima 727-0023, Japan
| | | | | | | |
Collapse
|
43
|
Abstract
Certain synthetic retinoid-related molecules induce apoptosis in cancer cells through a novel mechanism of retinoid action that is independent of the nuclear retinoid receptors. These compounds target protein kinases and protein phosphatases to trigger signal transduction pathways that lead to apoptosis. Whereas retinoid agonists such as CD437 activate stress kinases via inhibition of the phosphatase MKP-1, the retinoid antagonist MX781 inhibits the survival kinase IKK. These retinoid-mediated signaling pathways converge at the mitochondria, where they cause the release of cytochrome c and subsequent Apaf-1-dependent activation of caspases. Identification of the retinoid targets that mediate their apoptotic activity will enhance our understanding of the mechanism of this novel retinoid action, to allow appropriate optimization of currently available compounds to advance into the clinic as novel anticancer agents.
Collapse
Affiliation(s)
- Magnus Pfahl
- Incyte San Diego, Inc, 10835 Altman Row, San Diego, CA 92121, USA.
| | | |
Collapse
|
44
|
Go YM, Gipp JJ, Mulcahy RT, Jones DP. H2O2-dependent activation of GCLC-ARE4 reporter occurs by mitogen-activated protein kinase pathways without oxidation of cellular glutathione or thioredoxin-1. J Biol Chem 2003; 279:5837-45. [PMID: 14638694 DOI: 10.1074/jbc.m307547200] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The gp91phox homologue Nox1 produces H2O2, which induces cell growth, transformation, and tumorigenicity. However, it has not been clear whether H2O2 effects are mediated indirectly via a generally oxidizing cellular environment or whether H2O2 more directly targets specific signaling pathways. Here, we investigated signaling by H2O2 induced by Nox1 overexpression using a luciferase reporter regulated by the antioxidant response element ARE4. Surprisingly, Nox1-derived H2O2 activated the reporter gene 15-fold with no effect on the redox state of the major thiol antioxidant substances, glutathione and thioredoxin. H2O2 signaling to ARE4 was mediated by activation of both the c-Jun N-terminal kinase and ERK1/2 pathways modulated by Ras. Thus, "redox signaling" resulting in kinase signaling pathways is distinct from "oxidative stress," and is mediated by discrete, localized redox circuitry.
Collapse
Affiliation(s)
- Young-Mi Go
- Department of Medicine, Division of Cardiology, School of Medicine, Emory University, Atlanta, Georgia 30322, USA
| | | | | | | |
Collapse
|
45
|
Fu PP, Cheng SH, Coop L, Xia Q, Culp SJ, Tolleson WH, Wamer WG, Howard PC. Photoreaction, phototoxicity, and photocarcinogenicity of retinoids. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART C, ENVIRONMENTAL CARCINOGENESIS & ECOTOXICOLOGY REVIEWS 2003; 21:165-197. [PMID: 15845224 DOI: 10.1081/gnc-120026235] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Sunlight is a human carcinogen. Many retinoid-containing cosmetics are used to protect damages caused by sunlight irradiation. Since retinol is thermally unstable and retinyl palmitate (RP) s relatively more stable, RP is also widely used as an ingredient in cosmetic formulations. In general, little is known about the photodecomposition of retinoids and the toxicity of retinoids and their photodecomposition products on the skin's responses to sunlight. This review focuses on the update information on photoreactions, phototoxicity, and photocarcinogenicity of the natural retinoids including retinol, retinal, retinoid acid (RA), retinyl acetate, and RP.
Collapse
Affiliation(s)
- P P Fu
- National Center for Toxicological Research, US Food and Drug Administration, Jefferson, Arkansas 72079, USA.
| | | | | | | | | | | | | | | |
Collapse
|
46
|
Abstract
Cellular compartments differ dramatically in their redox potentials. This translates directly into variations in the extent of disulfide bond formation within proteins, depending on their cellular localization. It has long been assumed that proteins that are present in the reducing environment of the cytosol do not possess disulfide bonds. The recent discovery of a number of cytosolic proteins that use specific and reversible disulfide bond formation as a functional switch suggests that this view needs to be revised. Oxidative stress-induced disulfide bond formation appears to be the main strategy to adjust the protein activity of the oxidative stress transcription factors Yap1 and OxyR, the molecular chaperone Hsp33, and the anti-sigma factor RsrA. This elegant and rapid regulation allows the cells to respond quickly to environmental changes that manifest themselves in the accumulation of reactive oxygen species.
Collapse
Affiliation(s)
- Katrin Linke
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI 48109-1048, USA
| | | |
Collapse
|