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Yedla P, Bhamidipati P, Syed R, Amanchy R. Working title: Molecular involvement of p53-MDM2 interactome in gastrointestinal cancers. Cell Biochem Funct 2024; 42:e4075. [PMID: 38924101 DOI: 10.1002/cbf.4075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 05/30/2024] [Accepted: 06/04/2024] [Indexed: 06/28/2024]
Abstract
The interaction between murine double minute 2 (MDM2) and p53, marked by transcriptional induction and feedback inhibition, orchestrates a functional loop dictating cellular fate. The functional loop comprising p53-MDM2 axis is made up of an interactome consisting of approximately 81 proteins, which are spatio-temporally regulated and involved in DNA repair mechanisms. Biochemical and genetic alterations of the interactome result in dysregulation of the p53-mdm2 axis that leads to gastrointestinal (GI) cancers. A large subset of interactome is well known and it consists of proteins that either stabilize p53 or MDM2 and proteins that target the p53-MDM2 complex for ubiquitin-mediated destruction. Upstream signaling events brought about by growth factors and chemical messengers invoke a wide variety of posttranslational modifications in p53-MDM2 axis. Biochemical changes in the transactivation domain of p53 impact the energy landscape, induce conformational switching, alter interaction potential and could change solubility of p53 to redefine its co-localization, translocation and activity. A diverse set of chemical compounds mimic physiological effectors and simulate biochemical modifications of the p53-MDM2 interactome. p53-MDM2 interactome plays a crucial role in DNA damage and repair process. Genetic aberrations in the interactome, have resulted in cancers of GI tract (pancreas, liver, colorectal, gastric, biliary, and esophageal). We present in this article a review of the overall changes in the p53-MDM2 interactors and the effectors that form an epicenter for the development of next-generation molecules for understanding and targeting GI cancers.
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Affiliation(s)
- Poornachandra Yedla
- Division of Applied Biology, CSIR-IICT (Indian Institute of Chemical Technology), Ministry of Science and Technology (GOI), Hyderabad, Telangana, India
- Department of Pharmacogenomics, Institute of Translational Research, Asian Healthcare Foundation, Hyderabad, Telangana, India
| | - Pranav Bhamidipati
- Division of Applied Biology, CSIR-IICT (Indian Institute of Chemical Technology), Ministry of Science and Technology (GOI), Hyderabad, Telangana, India
- Department of Life Sciences, Imperial College London, London, UK
| | - Riyaz Syed
- Division of Applied Biology, CSIR-IICT (Indian Institute of Chemical Technology), Ministry of Science and Technology (GOI), Hyderabad, Telangana, India
| | - Ramars Amanchy
- Division of Applied Biology, CSIR-IICT (Indian Institute of Chemical Technology), Ministry of Science and Technology (GOI), Hyderabad, Telangana, India
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2
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Mao X, Huang L, Li T, Abliz Z, He J, Chen J. Identification of Diagnostic Metabolic Signatures in Thyroid Tumors Using Mass Spectrometry Imaging. Molecules 2023; 28:5791. [PMID: 37570761 PMCID: PMC10421042 DOI: 10.3390/molecules28155791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 07/26/2023] [Accepted: 07/26/2023] [Indexed: 08/13/2023] Open
Abstract
"Gray zone" thyroid follicular tumors are difficult to diagnose, especially when distinguishing between benign follicular thyroid adenoma (FTA) and malignant carcinoma (FTC). Thus, proper classification of thyroid follicular diseases may improve clinical prognosis. In this study, the diagnostic performance of metabolite enzymes was evaluated using imaging mass spectrometry to distinguish FTA from FTC and determine the association between metabolite enzyme expression with thyroid follicular borderline tumor diagnosis. Air flow-assisted desorption electrospray ionization mass spectrometry imaging (AFAIDESI-MSI) was used to build a classification model for thyroid follicular tumor characteristics among 24 samples. We analyzed metabolic enzyme marker expression in an independent validation set of 133 cases and further evaluated the potential biological behavior of 19 thyroid borderline lesions. Phospholipids and fatty acids (FAs) were more abundant in FTA than FTC (p < 0.001). The metabolic enzyme panel, which included FA synthase and Ca2+-independent PLA2, was further validated in follicular thyroid tumors. The marker combination showed optimal performance in the validation group (area under the ROC, sensitivity, and specificity: 73.6%, 82.1%, and 60.6%, respectively). The findings indicate that AFAIDESI-MSI, in combination with low metabolic enzyme expression, could play a role in the diagnosis of thyroid follicular borderline tumors for strict follow-up.
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Affiliation(s)
- Xinxin Mao
- Department of Pathology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China;
| | - Luojiao Huang
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China; (L.H.); (T.L.); (Z.A.)
| | - Tiegang Li
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China; (L.H.); (T.L.); (Z.A.)
| | - Zeper Abliz
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China; (L.H.); (T.L.); (Z.A.)
| | - Jiuming He
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China; (L.H.); (T.L.); (Z.A.)
| | - Jie Chen
- Department of Pathology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China;
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3
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Culp-Hill R, Stevens BM, Jones CL, Pei S, Dzieciatkowska M, Minhajuddin M, Jordan CT, D'Alessandro A. Therapy-Resistant Acute Myeloid Leukemia Stem Cells Are Resensitized to Venetoclax + Azacitidine by Targeting Fatty Acid Desaturases 1 and 2. Metabolites 2023; 13:metabo13040467. [PMID: 37110126 PMCID: PMC10142983 DOI: 10.3390/metabo13040467] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 03/21/2023] [Accepted: 03/22/2023] [Indexed: 04/29/2023] Open
Abstract
Recent advances in targeting leukemic stem cells (LSCs) using venetoclax with azacitidine (ven + aza) has significantly improved outcomes for de novo acute myeloid leukemia (AML) patients. However, patients who relapse after traditional chemotherapy are often venetoclax-resistant and exhibit poor clinical outcomes. We previously described that fatty acid metabolism drives oxidative phosphorylation (OXPHOS) and acts as a mechanism of LSC survival in relapsed/refractory AML. Here, we report that chemotherapy-relapsed primary AML displays aberrant fatty acid and lipid metabolism, as well as increased fatty acid desaturation through the activity of fatty acid desaturases 1 and 2, and that fatty acid desaturases function as a mechanism of recycling NAD+ to drive relapsed LSC survival. When combined with ven + aza, the genetic and pharmacologic inhibition of fatty acid desaturation results in decreased primary AML viability in relapsed AML. This study includes the largest lipidomic profile of LSC-enriched primary AML patient cells to date and indicates that inhibition of fatty acid desaturation is a promising therapeutic target for relapsed AML.
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Affiliation(s)
- Rachel Culp-Hill
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Brett M Stevens
- Division of Hematology, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Courtney L Jones
- Department of Medical Biophysics, University of Toronto Princess Margaret Cancer Center, Toronto, ON M5G 1L7, Canada
| | - Shanshan Pei
- Division of Hematology, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Monika Dzieciatkowska
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Mohammad Minhajuddin
- Division of Hematology, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Craig T Jordan
- Division of Hematology, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Angelo D'Alessandro
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
- Division of Hematology, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
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4
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Andrade A, Poth T, Brobeil A, Merle U, Chamulitrat W. iPLA2β-Null Mice Show HCC Protection by an Induction of Cell-Cycle Arrest after Diethylnitrosamine Treatment. Int J Mol Sci 2022; 23:ijms232213760. [PMID: 36430237 PMCID: PMC9697657 DOI: 10.3390/ijms232213760] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 11/04/2022] [Accepted: 11/08/2022] [Indexed: 11/11/2022] Open
Abstract
Group VIA phospholipase A2 (iPLA2β) play diverse biological functions in epithelial cells and macrophages. Global deletion in iPLA2β-null (KO) mice leads to protection against hepatic steatosis in non-alcoholic fatty liver disease, in part, due to the replenishment of the loss of hepatocellular phospholipids. As the loss of phospholipids also occurs in hepatocellular carcinoma (HCC), we hypothesized that global deletion in KO mice may lead to protection against HCC. Here, HCC induced by diethylnitrosamine (DEN) was chosen because DEN causes direct injury to the hepatocytes. Male wild-type (WT) and KO mice at 3-5 weeks of age (12-13 mice/group) were subjected to a single intraperitoneal treatment with 10 mg/kg DEN, and mice were killed 12 months later. Analyses of histology, plasma cytokines, and gene expression were performed. Due to the low-dose DEN used, we observed a liver nodule in 3 of 13 WT and 2 of 12 KO mice. Only one DEN-treated WT mouse was confirmed to have HCC. DEN-treated KO mice did not show any HCC but showed suppressed hepatic expression of cell-cycle cyclinD2 and BCL2 as well as inflammatory markers IL-1β, IL-10, and VCAM-1. Notably, DEN-treated KO mice showed increased hepatic necrosis and elevated levels of plasma lactate dehydrogenase suggesting an exacerbation of liver injury. Thus, global iPLA2β deficiency in DEN-treated mice rendered HCC protection by an induction of cell-cycle arrest. Our results suggest the role of iPLA2β inhibition in HCC treatment.
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Affiliation(s)
- Adriana Andrade
- Department of Internal Medicine IV (Gastroenterology and Infectious Disease), University Hospital Heidelberg, 69120 Heidelberg, Germany
| | - Tanja Poth
- Center for Model System and Comparative Pathology, University Hospital Heidelberg, 69120 Heidelberg, Germany
| | - Alexander Brobeil
- Tissuebank of the NCT, Institute of Pathology, University Hospital Heidelberg, 69120 Heidelberg, Germany
| | - Uta Merle
- Department of Internal Medicine IV (Gastroenterology and Infectious Disease), University Hospital Heidelberg, 69120 Heidelberg, Germany
| | - Walee Chamulitrat
- Department of Internal Medicine IV (Gastroenterology and Infectious Disease), University Hospital Heidelberg, 69120 Heidelberg, Germany
- Correspondence:
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Ovejero S, Soulet C, Kumanski S, Moriel-Carretero M. Coordination between phospholipid pools and DNA damage sensing. Biol Cell 2022; 114:211-219. [PMID: 35524759 DOI: 10.1111/boc.202200007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 04/22/2022] [Accepted: 04/22/2022] [Indexed: 11/27/2022]
Abstract
Both phospholipid synthesis and the detection of DNA damage are coupled to cell cycle progression, yet whether these two aspects crosstalk to each other remains unassessed. We postulate here that shortage of phospholipids, which negatively affects proliferation, may reduce the need for checkpoint activation in response to DNA damage. By exploring the DDR activation in response to seven different genotoxins, in three distinct cell types, and manipulating phospholipid synthesis both pharmacologically and genetically, we point at the DNA damage response kinase ATR as responsible for the coordination between phospholipid levels and DNA damage sensing. Further, our analysis reveals the functional significance of this crosstalk to keep genome homeostasis. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Sara Ovejero
- Institut de Génétique Humaine (IGH), Université de Montpellier-Centre National de la Recherche Scientifique, Montpellier, France.,Department of Biological Hematology, CHU Montpellier, Montpellier, 34295, France
| | - Caroline Soulet
- Centre de Recherche en Biologie cellulaire de Montpellier (CRBM), Université de Montpellier-Centre National de la Recherche Scientifique, Montpellier, France
| | - Sylvain Kumanski
- Centre de Recherche en Biologie cellulaire de Montpellier (CRBM), Université de Montpellier-Centre National de la Recherche Scientifique, Montpellier, France
| | - María Moriel-Carretero
- Centre de Recherche en Biologie cellulaire de Montpellier (CRBM), Université de Montpellier-Centre National de la Recherche Scientifique, Montpellier, France
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6
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Moriel-Carretero M. The Many Faces of Lipids in Genome Stability (and How to Unmask Them). Int J Mol Sci 2021; 22:12930. [PMID: 34884734 PMCID: PMC8657548 DOI: 10.3390/ijms222312930] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 11/12/2021] [Accepted: 11/26/2021] [Indexed: 12/15/2022] Open
Abstract
Deep efforts have been devoted to studying the fundamental mechanisms ruling genome integrity preservation. A strong focus relies on our comprehension of nucleic acid and protein interactions. Comparatively, our exploration of whether lipids contribute to genome homeostasis and, if they do, how, is severely underdeveloped. This disequilibrium may be understood in historical terms, but also relates to the difficulty of applying classical lipid-related techniques to a territory such as a nucleus. The limited research in this domain translates into scarce and rarely gathered information, which with time further discourages new initiatives. In this review, the ways lipids have been demonstrated to, or very likely do, impact nuclear transactions, in general, and genome homeostasis, in particular, are explored. Moreover, a succinct yet exhaustive battery of available techniques is proposed to tackle the study of this topic while keeping in mind the feasibility and habits of "nucleus-centered" researchers.
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Affiliation(s)
- María Moriel-Carretero
- Centre de Recherche en Biologie Cellulaire de Montpellier (CRBM), Université de Montpellier, Centre National de la Recherche Scientifique, CEDEX 5, 34293 Montpellier, France
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7
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Choi JW, Joo JD, In JH, Kim D, Kim Y, Choi ST, Kim JH, Jung HS. The small molecule kobusone can stimulate islet β-cell replication in vivo. J Int Med Res 2021; 49:3000605211032849. [PMID: 34320857 PMCID: PMC8330483 DOI: 10.1177/03000605211032849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
OBJECTIVE To investigate the ability of kobusone to reduce high glucose levels and promote β-cell proliferation. METHODS Four-week-old female db/db mice were assigned to the kobusone (25 mg/kg body weight, intraperitoneally twice a day) or control group (same volume of PBS). Glucose levels and body weight were measured twice a week. After 6 weeks, intraperitoneal glucose tolerance tests and immunohistochemical studies were performed, and insulin levels were determined. The expression of mRNAs involved in cell proliferation, such as PI3K, Akt, cyclin D3 and p57Kip2, was measured by quantitative reverse transcription polymerase chain reaction (RT-qPCR). RESULTS Kobusone reduced blood glucose levels after 3 weeks and more strongly increased serum insulin levels than the vehicle. Immunohistochemistry illustrated that kobusone increased 5-bromo-2'-deoxyuridine incorporation into islet β-cells, suggesting that it can stimulate islet β-cell replication in vivo. RT-qPCR indicated that kobusone upregulated the mRNA expression of PI3K, Akt, and cyclin D3 and downregulated that of p57Kip2. CONCLUSION Our findings suggest that kobusone is a potent pancreatic islet β-cell inducer that has the potential to be developed as an anti-diabetic agent.
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Affiliation(s)
- Jin Woo Choi
- Department of Anesthesiology and Pain Medicine, St. Vincent's Hospital, The Catholic University of Korea, Suwon, Korea
| | - Jin-Deok Joo
- Department of Anesthesiology and Pain Medicine, St. Vincent's Hospital, The Catholic University of Korea, Suwon, Korea
| | - Jang Hyeok In
- Department of Anesthesiology and Pain Medicine, St. Vincent's Hospital, The Catholic University of Korea, Suwon, Korea
| | - Daewoo Kim
- Department of Anesthesiology and Pain Medicine, St. Vincent's Hospital, The Catholic University of Korea, Suwon, Korea
| | - Yongshin Kim
- Department of Anesthesiology and Pain Medicine, St. Vincent's Hospital, The Catholic University of Korea, Suwon, Korea
| | - Seung Tae Choi
- Department of Anesthesiology and Pain Medicine, St. Vincent's Hospital, The Catholic University of Korea, Suwon, Korea
| | - Jung Han Kim
- Department of Anesthesiology and Pain Medicine, St. Vincent's Hospital, The Catholic University of Korea, Suwon, Korea
| | - Hong Soo Jung
- Department of Anesthesiology and Pain Medicine, St. Vincent's Hospital, The Catholic University of Korea, Suwon, Korea
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Rescue of Hepatic Phospholipid Remodeling Defectin iPLA2β-Null Mice Attenuates Obese but Not Non-Obese Fatty Liver. Biomolecules 2020; 10:biom10091332. [PMID: 32957701 PMCID: PMC7565968 DOI: 10.3390/biom10091332] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 09/15/2020] [Accepted: 09/15/2020] [Indexed: 12/19/2022] Open
Abstract
Polymorphisms of group VIA calcium-independent phospholipase A2 (iPLA2β or PLA2G6) are positively associated with adiposity, blood lipids, and Type-2 diabetes. The ubiquitously expressed iPLA2β catalyzes the hydrolysis of phospholipids (PLs) to generate a fatty acid and a lysoPL. We studied the role of iPLA2β on PL metabolism in non-alcoholic fatty liver disease (NAFLD). By using global deletion iPLA2β-null mice, we investigated three NAFLD mouse models; genetic Ob/Ob and long-term high-fat-diet (HFD) feeding (representing obese NAFLD) as well as feeding with methionine- and choline-deficient (MCD) diet (representing non-obese NAFLD). A decrease of hepatic PLs containing monounsaturated- and polyunsaturated fatty acids and a decrease of the ratio between PLs and cholesterol esters were observed in all three NAFLD models. iPLA2β deficiency rescued these decreases in obese, but not in non-obese, NAFLD models. iPLA2β deficiency elicited protection against fatty liver and obesity in the order of Ob/Ob › HFD » MCD. Liver inflammation was not protected in HFD NAFLD, and that liver fibrosis was even exaggerated in non-obese MCD model. Thus, the rescue of hepatic PL remodeling defect observed in iPLA2β-null mice was critical for the protection against NAFLD and obesity. However, iPLA2β deletion in specific cell types such as macrophages may render liver inflammation and fibrosis, independent of steatosis protection.
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Huang J, Wang Q, Qi Z, Zhou S, Zhou M, Wang Z. Lipidomic Profiling for Serum Biomarkers in Mice Exposed to Ionizing Radiation. Dose Response 2020; 18:1559325820914209. [PMID: 32362795 PMCID: PMC7180312 DOI: 10.1177/1559325820914209] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 01/06/2020] [Accepted: 02/24/2020] [Indexed: 12/23/2022] Open
Abstract
Radiation biodosimeters are required urgently for fast and accurate evaluation of
absorbed dose for irradiated individuals. Lipidomics has appeared as a credible
technique for identification and quantification of lipid for researching
biomarker of diseases. We performed a lipidomic profile on mice serum at time
points of 6, 24, and 72 hours after 0, 2, 5.5, 7, and 8 Gy irradiation to select
radiation-responsive lipids and conducted Kyoto Encyclopedia of Genes and Genome
pathway enrichment analysis to recognize the pathways and network changes. Then,
Pearson correlation analysis was performed to evaluate the feasibility of
radiation-responsive lipids to estimate radiation dose. Seven
radiation-responsive lipids including PC (18:2/18:2), PC (18:0/18:2), Lyso PC
18:1, PC (18:0/20:4), SM (D18:0/24:1), PC (16:0/18:1), and Lyso PC 18:2 were
identified in which glycerophospholipid metabolism presented as the most
significant pathway, and they all presented good linear correlation with the
irradiated dose. This study identified 7 radiation-responsive lipids in mice
serum and certificate their feasibility of dose estimation as biodosimeters.
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Affiliation(s)
- Jinfeng Huang
- Department of Radiation Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, People's Republic of China
| | - Qi Wang
- Department of Radiobiology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, People's Republic of China
| | - Zhenhua Qi
- Department of Radiobiology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, People's Republic of China
| | - Shixiang Zhou
- Department of Radiobiology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, People's Republic of China
| | - Meijuan Zhou
- Department of Radiation Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, People's Republic of China
| | - Zhidong Wang
- Department of Radiobiology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, People's Republic of China
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Ishikawa T, Suwanai H, Shikuma J, Suzuki R, Yamanaka T, Odawara M, Inazu M. Protein kinase C promotes choline transporter‑like protein 1 function via improved cell surface expression in immortalized human hepatic cells. Mol Med Rep 2019; 21:777-785. [PMID: 31974614 PMCID: PMC6947888 DOI: 10.3892/mmr.2019.10894] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Accepted: 10/16/2019] [Indexed: 12/30/2022] Open
Abstract
Choline is used to synthesize phospholipids and a lack of choline induces a number of liver-related diseases, including non-alcoholic steatohepatitis. The current study characterized the choline uptake system, at molecular and functional levels, in the immortalized human hepatic cell line, Fa2N-4, to identify the specific choline transporter involved in choline uptake. The present study also assesed whether choline deficiency or the inhibited choline uptake affected cell viability and apoptosis. Reverse transcription-quantitative polymerase chain reaction (PCR) revealed choline transporter-like protein 1 (CTL1) and CTL2 mRNA and protein expression in Fa2N-4 cells. [Methyl-3H]choline studies revealed choline uptake was saturable and mediated by a single transport system that functioned in a Na+-independent but pH-dependent manner, which was similar to CTL1. Hemicholinium-3 (HC-3), which is a choline uptake inhibitor, and choline deficiency inhibited cell viability, increased caspase-3 and −7 activities, and increased fluorescein isothiocyanate-Annexin V immunofluorescent staining indicated apoptosis. Immunofluorescent staining also revealed CTL1 and CTL2 localized in plasma and mitochondrial membranes, respectively. [Methyl-3H]choline uptake was enhanced by a protein kinase C (PKC) activator, phorbol-12-myristate 13-acetate (PMA). Immunofluorescence staining and western blot analysis demonstrated increased CTL1 expression on the cell membrane following PMA treatment. The results of current study indicated that extracellular choline is primarily transported via CTL1, relying on a direct H+ gradient that functions as a driving force in Fa2N-4 cells. Furthermore, it was hypothesized that CTL1 and the choline uptake system are strongly associated with cell survival, and that the choline uptake system is modulated by PKC signaling via increased CTL1 expression on the cell surface. These findings provide further insights into the pathogenesis of liver disease involving choline metabolism.
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Affiliation(s)
- Takuya Ishikawa
- Department of Diabetes, Metabolism and Endocrinology, Tokyo Medical University, Tokyo 160‑0023, Japan
| | - Hirotsugu Suwanai
- Department of Diabetes, Metabolism and Endocrinology, Tokyo Medical University, Tokyo 160‑0023, Japan
| | - Junpei Shikuma
- Department of Diabetes, Metabolism and Endocrinology, Tokyo Medical University, Tokyo 160‑0023, Japan
| | - Ryo Suzuki
- Department of Diabetes, Metabolism and Endocrinology, Tokyo Medical University, Tokyo 160‑0023, Japan
| | - Tsuyoshi Yamanaka
- Department of Molecular Preventive Medicine, Tokyo Medical University, Tokyo 160‑8402, Japan
| | - Masato Odawara
- Department of Diabetes, Metabolism and Endocrinology, Tokyo Medical University, Tokyo 160‑0023, Japan
| | - Masato Inazu
- Department of Molecular Preventive Medicine, Tokyo Medical University, Tokyo 160‑8402, Japan
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Abstract
DNA repair proteins have been found to localize to the centrosomes and defects in these proteins cause centrosome abnormality. Centrobin is a centriole-associated protein that is required for centriole duplication and microtubule stability. A recent study revealed that centrobin is a candidate substrate for ATM/ATR kinases. However, whether centrobin is involved in DNA damage response (DDR) remains unexplored. Here we show that centrobin is phosphorylated after UV exposure and that the phosphorylation is detected exclusively in the detergent/DNase I-resistant nuclear matrix. UV-induced phosphorylation of centrobin is largely dependent on ATR activity. Centrobin-depleted cells show impaired DNA damage-induced microtubule stabilization and increased sensitivity to UV radiation. Interestingly, depletion of centrobin leads to defective homologous recombination (HR) repair, which is reversed by expression of wild-type centrobin. Taken together, these results strongly suggest that centrobin plays an important role in DDR.
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Affiliation(s)
- Na Mi Ryu
- Department of Pharmacology, Chonnam National University Medical School , Jellanamdo , Republic of Korea
| | - Jung Min Kim
- Department of Pharmacology, Chonnam National University Medical School , Jellanamdo , Republic of Korea
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12
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Dymond MK. Mammalian phospholipid homeostasis: evidence that membrane curvature elastic stress drives homeoviscous adaptation in vivo. J R Soc Interface 2017; 13:rsif.2016.0228. [PMID: 27534697 DOI: 10.1098/rsif.2016.0228] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 07/25/2016] [Indexed: 12/23/2022] Open
Abstract
Several theories of phospholipid homeostasis have postulated that cells regulate the molecular composition of their bilayer membranes, such that a common biophysical membrane parameter is under homeostatic control. Two commonly cited theories are the intrinsic curvature hypothesis, which states that cells control membrane curvature elastic stress, and the theory of homeoviscous adaptation, which postulates cells control acyl chain packing order (membrane order). In this paper, we present evidence from data-driven modelling studies that these two theories correlate in vivo. We estimate the curvature elastic stress of mammalian cells to be 4-7 × 10(-12) N, a value high enough to suggest that in mammalian cells the preservation of membrane order arises through a mechanism where membrane curvature elastic stress is controlled. These results emerge from analysing the molecular contribution of individual phospholipids to both membrane order and curvature elastic stress in nearly 500 cellular compositionally diverse lipidomes. Our model suggests that the de novo synthesis of lipids is the dominant mechanism by which cells control curvature elastic stress and hence membrane order in vivo These results also suggest that cells can increase membrane curvature elastic stress disproportionately to membrane order by incorporating polyunsaturated fatty acids into lipids.
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Affiliation(s)
- Marcus K Dymond
- Division of Chemistry, School of Pharmacy and Biological Sciences, University of Brighton, Brighton BN2 4GL, UK
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13
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Jiao L, Gan-Schreier H, Zhu X, Wei W, Tuma-Kellner S, Liebisch G, Stremmel W, Chamulitrat W. Ageing sensitized by iPLA 2β deficiency induces liver fibrosis and intestinal atrophy involving suppression of homeostatic genes and alteration of intestinal lipids and bile acids. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1862:1520-1533. [PMID: 28888832 DOI: 10.1016/j.bbalip.2017.09.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 08/28/2017] [Accepted: 09/05/2017] [Indexed: 01/06/2023]
Abstract
Ageing is a major risk factor for various forms of liver and gastrointestinal (GI) disease and genetic background may contribute to the pathogenesis of these diseases. Group VIA phospholipase A2 or iPLA2β is a homeostatic PLA2 by playing a role in phospholipid metabolism and remodeling. Global iPLA2β-/- mice exhibit aged-dependent phenotypes with body weight loss and abnormalities in the bone and brain. We have previously reported the abnormalities in these mutant mice showing susceptibility for chemical-induced liver injury and colitis. We hypothesize that iPLA2β deficiency may sensitize with ageing for an induction of GI injury. Male wild-type and iPLA2β-/- mice at 4 and 20-22months of age were studied. Aged, but not young, iPLA2β-/-mice showed increased hepatic fibrosis and biliary ductular expansion as well as severe intestinal atrophy associated with increased apoptosis, pro-inflammation, disrupted tight junction, and reduced number of mucin-containing globlet cells. This damage was associated with decreased expression of intestinal endoplasmic stress XBP1 and its regulator HNF1α, FATP4, ACSL5, bile-acid transport genes as well as nuclear receptors LXRα and FXR. By LC/MS-MS profiling, iPLA2β deficiency in aged mice caused an increase of intestinal arachidonate-containing phospholipids concomitant with a decrease in ceramides. By the suppression of intestinal FXR/FGF-15 signaling, hepatic bile-acid synthesis gene expression was increased leading to an elevation of secondary and hydrophobic bile acids in liver, bile, and intestine. In conclusions, ageing sensitized by iPLA2β deficiency caused a decline of key intestinal homeostatic genes resulting in the development of GI disease in a gut-to-liver manner.
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Affiliation(s)
- Li Jiao
- Department of Internal Medicine IV, University of Heidelberg Hospital, Heidelberg, Germany; Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming, Yunnan 650118, China
| | - Hongying Gan-Schreier
- Department of Internal Medicine IV, University of Heidelberg Hospital, Heidelberg, Germany
| | - Xingya Zhu
- Department of Internal Medicine IV, University of Heidelberg Hospital, Heidelberg, Germany
| | - Wang Wei
- Department of Internal Medicine IV, University of Heidelberg Hospital, Heidelberg, Germany
| | - Sabine Tuma-Kellner
- Department of Internal Medicine IV, University of Heidelberg Hospital, Heidelberg, Germany
| | - Gerhard Liebisch
- Institute of Clinical Chemistry and Laboratory Medicine, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany
| | - Wolfgang Stremmel
- Department of Internal Medicine IV, University of Heidelberg Hospital, Heidelberg, Germany
| | - Walee Chamulitrat
- Department of Internal Medicine IV, University of Heidelberg Hospital, Heidelberg, Germany.
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Festarini A, Shultz C, Stuart M, Kim SB, Ferreri C. CELLULAR RESPONSES TO TRITIUM EXPOSURE IN RAINBOW TROUT: HTO- AND OBT-SPIKED FEED EXPOSURE EXPERIMENTS. CNL NUCLEAR REVIEW 2016. [DOI: 10.12943/cnr.2015.00059] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Biological effects were evaluated in rainbow trout (Oncorhynchus mykiss) exposed to tritiated water (HTO) or food spiked with organically bound tritium (OBT). An HTO exposure study was conducted using a tritium activity concentration of 7000 Bq/L, and an OBT exposure study was conducted using a tritium activity concentration of 30 000 Bq/L. Following 140 days of in vivo HTO exposure, liver, heart, spleen, kidney, and brain cells did not show statistically significant differences in viability; kidney, liver, and spleen cells did not show significant differences in DNA double-strand break repair activity compared with control cells. Membrane fatty acid composition analysis was conducted on liver cells and no effects of HTO exposure could be detected. Following 140 days of in vivo OBT exposure, viability and DNA double-strand break repair activity were not statistically different from controls in liver, heart, spleen, kidney, and brain cells. Changes, however, were noted in the fatty acid composition of liver and muscle tissues. For both studies, all measurements were performed on each tissue and on a fraction of the same tissue that was exposed to a gamma 4 Gy dose in vitro to test for adaptive responses, and no effects were observed except for fatty acid composition. The findings demonstrated that membrane fatty acid composition is a sensitive marker and that microscopic evaluation of gamma-H2AX foci is more sensitive than the flow cytometric approach. These studies are the first to correlate uptake and depuration with biological health indicators in edible fish for tritium exposures within worldwide drinking water guidelines.
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Affiliation(s)
- Amy Festarini
- Canadian Nuclear Laboratories, Chalk River, ON K0J 1J0, Canada
| | - Carmen Shultz
- Canadian Nuclear Laboratories, Chalk River, ON K0J 1J0, Canada
| | - Marilyne Stuart
- Canadian Nuclear Laboratories, Chalk River, ON K0J 1J0, Canada
| | - Sang Bog Kim
- Canadian Nuclear Laboratories, Chalk River, ON K0J 1J0, Canada
| | - Carla Ferreri
- Department of Chemical Sciences and Materials Technologies of the National Research Council of Italy, Bologna, Italy
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15
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Abstract
ATR (Ataxia Telangiectasia and Rad3-related) is a member of the Phosphatidylinositol 3-kinase-related kinases (PIKKs) family, amongst six other vertebrate proteins known so far. ATR is indispensable for cell survival and its essential role is in sensing DNA damage and initiating appropriate repair responses. In this review we highlight emerging and recent observations connecting ATR to alternative roles in controlling the nuclear envelope, nucleolus, centrosome and other organelles in response to both internal and external stress conditions. We propose that ATR functions control cell plasticity by sensing structural deformations of different cellular components, including DNA and initiating appropriate repair responses, most of which are yet to be understood completely.
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Affiliation(s)
- Gururaj Rao Kidiyoor
- Istituto FIRC di Oncologia Molecolare, Milan, Italy; University of Milan, Milan, Italy
| | - Amit Kumar
- Developmental Toxicology Laboratory, Systems Toxicology and Health Risk Assessment Group, CSIR-Indian Institute of Toxicology Research, M.G. Marg, Lucknow 226001, India; Academy of Scientific and Innovative Research (AcSIR), India
| | - Marco Foiani
- Istituto FIRC di Oncologia Molecolare, Milan, Italy; University of Milan, Milan, Italy.
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Deng X, Wang J, Jiao L, Utaipan T, Tuma-Kellner S, Schmitz G, Liebisch G, Stremmel W, Chamulitrat W. iPLA2β deficiency attenuates obesity and hepatic steatosis in ob/ob mice through hepatic fatty-acyl phospholipid remodeling. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:449-61. [PMID: 26873633 DOI: 10.1016/j.bbalip.2016.02.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 02/01/2016] [Accepted: 02/06/2016] [Indexed: 01/12/2023]
Abstract
PLA2G6 or GVIA calcium-independent PLA2 (iPLA2β) is identified as one of the NAFLD modifier genes in humans, and thought to be a target for NAFLD therapy. iPLA2β is known to play a house-keeping role in phospholipid metabolism and remodeling. However, its role in NAFLD pathogenesis has not been supported by results obtained from high-fat feeding of iPLA2β-null (PKO) mice. Unlike livers of human NAFLD and genetically obese rodents, fatty liver induced by high-fat diet is not associated with depletion of hepatic phospholipids. We therefore tested whether iPLA2β could regulate obesity and hepatic steatosis in leptin-deficient mice by cross-breeding PKO with ob/ob mice to generate ob/ob-PKO mice. Here we observed an improvement in ob/ob-PKO mice with significant reduction in serum enzymes, lipids, glucose, insulin as well as improved glucose tolerance, and reduction in islet hyperplasia. The improvement in hepatic steatosis measured by liver triglycerides, fatty acids and cholesterol esters was associated with decreased expression of PPARγ and de novo lipogenesis genes, and the reversal of β-oxidation gene expression. Notably, ob/ob livers contained depleted levels of lysophospholipids and phospholipids, and iPLA2β deficiency in ob/ob-PKO livers lowers the former, but replenished the latter particularly phosphatidylethanolamine (PE) and phosphatidylcholine (PC) that contained arachidonic (AA) and docosahexaenoic (DHA) acids. Compared with WT livers, PKO livers also contained increased PE and PC containing AA and DHA. Thus, iPLA2β deficiency protected against obesity and ob/ob fatty liver which was associated with hepatic fatty-acyl phospholipid remodeling. Our results support the deleterious role of iPLA2β in severe obesity associated NAFLD.
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Affiliation(s)
- Xiuling Deng
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 430022 Wuhan, China
| | - Jiliang Wang
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Li Jiao
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Tanyarath Utaipan
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Sabine Tuma-Kellner
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Gerd Schmitz
- Institute of Clinical Chemistry and Laboratory Medicine, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany
| | - Gerhard Liebisch
- Institute of Clinical Chemistry and Laboratory Medicine, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany
| | - Wolfgang Stremmel
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Walee Chamulitrat
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany.
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17
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Ramanadham S, Ali T, Ashley JW, Bone RN, Hancock WD, Lei X. Calcium-independent phospholipases A2 and their roles in biological processes and diseases. J Lipid Res 2015; 56:1643-68. [PMID: 26023050 DOI: 10.1194/jlr.r058701] [Citation(s) in RCA: 135] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Indexed: 12/24/2022] Open
Abstract
Among the family of phospholipases A2 (PLA2s) are the Ca(2+)-independent PLA2s (iPLA2s) and they are designated group VI iPLA2s. In relation to secretory and cytosolic PLA2s, the iPLA2s are more recently described and details of their expression and roles in biological functions are rapidly emerging. The iPLA2s or patatin-like phospholipases (PNPLAs) are intracellular enzymes that do not require Ca(2+) for activity, and contain lipase (GXSXG) and nucleotide-binding (GXGXXG) consensus sequences. Though nine PNPLAs have been recognized, PNPLA8 (membrane-associated iPLA2γ) and PNPLA9 (cytosol-associated iPLA2β) are the most widely studied and understood. The iPLA2s manifest a variety of activities in addition to phospholipase, are ubiquitously expressed, and participate in a multitude of biological processes, including fat catabolism, cell differentiation, maintenance of mitochondrial integrity, phospholipid remodeling, cell proliferation, signal transduction, and cell death. As might be expected, increased or decreased expression of iPLA2s can have profound effects on the metabolic state, CNS function, cardiovascular performance, and cell survival; therefore, dysregulation of iPLA2s can be a critical factor in the development of many diseases. This review is aimed at providing a general framework of the current understanding of the iPLA2s and discussion of the potential mechanisms of action of the iPLA2s and related involved lipid mediators.
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Affiliation(s)
- Sasanka Ramanadham
- Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294 Comprehensive Diabetes Center, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Tomader Ali
- Undergraduate Research Office, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Jason W Ashley
- Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA 19104
| | - Robert N Bone
- Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294 Comprehensive Diabetes Center, University of Alabama at Birmingham, Birmingham, AL 35294
| | - William D Hancock
- Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294 Comprehensive Diabetes Center, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Xiaoyong Lei
- Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294 Comprehensive Diabetes Center, University of Alabama at Birmingham, Birmingham, AL 35294
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18
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Kumar A, Mazzanti M, Mistrik M, Kosar M, Beznoussenko GV, Mironov AA, Garrè M, Parazzoli D, Shivashankar GV, Scita G, Bartek J, Foiani M. ATR mediates a checkpoint at the nuclear envelope in response to mechanical stress. Cell 2015; 158:633-46. [PMID: 25083873 PMCID: PMC4121522 DOI: 10.1016/j.cell.2014.05.046] [Citation(s) in RCA: 155] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2013] [Revised: 04/14/2014] [Accepted: 05/28/2014] [Indexed: 11/16/2022]
Abstract
ATR controls chromosome integrity and chromatin dynamics. We have previously shown that yeast Mec1/ATR promotes chromatin detachment from the nuclear envelope to counteract aberrant topological transitions during DNA replication. Here, we provide evidence that ATR activity at the nuclear envelope responds to mechanical stress. Human ATR associates with the nuclear envelope during S phase and prophase, and both osmotic stress and mechanical stretching relocalize ATR to nuclear membranes throughout the cell cycle. The ATR-mediated mechanical response occurs within the range of physiological forces, is reversible, and is independent of DNA damage signaling. ATR-defective cells exhibit aberrant chromatin condensation and nuclear envelope breakdown. We propose that mechanical forces derived from chromosome dynamics and torsional stress on nuclear membranes activate ATR to modulate nuclear envelope plasticity and chromatin association to the nuclear envelope, thus enabling cells to cope with the mechanical strain imposed by these molecular processes. ATR localizes at the nuclear envelope in S phase and prophase ATR responds to mechanical stress by relocalizing to the nuclear envelope The ATR mechanical response is fast and reversible ATR coordinates chromatin condensation and nuclear envelope breakdown
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Affiliation(s)
- Amit Kumar
- Fondazione Istituto FIRC di Oncologia Molecolare (IFOM), Via Adamello 16, 20139 Milan, Italy
| | | | - Martin Mistrik
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University, 77115 Olomouc, Czech Republic
| | - Martin Kosar
- Danish Cancer Society Research Center, 2100 Copenhagen, Denmark; Institute of Molecular Genetics, v.v.i., Academy of Sciences of the Czech Republic, 14220 Prague, Czech Republic
| | - Galina V Beznoussenko
- Fondazione Istituto FIRC di Oncologia Molecolare (IFOM), Via Adamello 16, 20139 Milan, Italy
| | - Alexandre A Mironov
- Fondazione Istituto FIRC di Oncologia Molecolare (IFOM), Via Adamello 16, 20139 Milan, Italy
| | - Massimiliano Garrè
- Fondazione Istituto FIRC di Oncologia Molecolare (IFOM), Via Adamello 16, 20139 Milan, Italy
| | - Dario Parazzoli
- Fondazione Istituto FIRC di Oncologia Molecolare (IFOM), Via Adamello 16, 20139 Milan, Italy
| | - G V Shivashankar
- Mechanobiology Institute and Department of Biological Sciences, National University of Singapore, 117411 Singapore, Singapore
| | - Giorgio Scita
- Fondazione Istituto FIRC di Oncologia Molecolare (IFOM), Via Adamello 16, 20139 Milan, Italy; Università degli Studi di Milano, 20122 Milan, Italy
| | - Jiri Bartek
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University, 77115 Olomouc, Czech Republic; Danish Cancer Society Research Center, 2100 Copenhagen, Denmark; Institute of Molecular Genetics, v.v.i., Academy of Sciences of the Czech Republic, 14220 Prague, Czech Republic.
| | - Marco Foiani
- Fondazione Istituto FIRC di Oncologia Molecolare (IFOM), Via Adamello 16, 20139 Milan, Italy; Università degli Studi di Milano, 20122 Milan, Italy.
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19
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Lacroix M, Linares LK, Le Cam L. Rôle du suppresseur de tumeurs p53 dans le contrôle du métabolisme. Med Sci (Paris) 2013; 29:1125-30. [DOI: 10.1051/medsci/20132912016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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20
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Ridgway ND. The role of phosphatidylcholine and choline metabolites to cell proliferation and survival. Crit Rev Biochem Mol Biol 2013; 48:20-38. [PMID: 23350810 DOI: 10.3109/10409238.2012.735643] [Citation(s) in RCA: 206] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The reorganization of metabolic pathways in cancer facilitates the flux of carbon and reducing equivalents into anabolic pathways at the expense of oxidative phosphorylation. This provides rapidly dividing cells with the necessary precursors for membrane, protein and nucleic acid synthesis. A fundamental metabolic perturbation in cancer is the enhanced synthesis of fatty acids by channeling glucose and/or glutamine into cytosolic acetyl-CoA and upregulation of key biosynthetic genes. This lipogenic phenotype also extends to the production of complex lipids involved in membrane synthesis and lipid-based signaling. Cancer cells display sensitivity to ablation of fatty acid synthesis possibly as a result of diminished capacity to synthesize complex lipids involved in signaling or growth pathways. Evidence has accrued that phosphatidylcholine, the major phospholipid component of eukaryotic membranes, as well as choline metabolites derived from its synthesis and catabolism, contribute to both proliferative growth and programmed cell death. This review will detail our current understanding of how coordinated changes in substrate availability, gene expression and enzyme activity lead to altered phosphatidylcholine synthesis in cancer, and how these changes contribute directly or indirectly to malignant growth. Conversely, apoptosis targets key steps in phosphatidylcholine synthesis and degradation that are linked to disruption of cell cycle regulation, reinforcing the central role that phosphatidylcholine and its metabolites in determining cell fate.
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Affiliation(s)
- Neale D Ridgway
- Departments of Pediatrics and Biochemistry & Molecular Biology, The Atlantic Research Centre, Dalhousie University, Halifax, Nova Scotia Canada.
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21
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Kehler AK, Andersen C, Andreasen JR, Vohra R, Junker N, Poulsen KA, Kolko M. Interaction between VEGF and Calcium-Independent Phospholipase A2in Proliferation and Migration of Retinal Pigment Epithelium. Curr Eye Res 2012; 37:500-7. [DOI: 10.3109/02713683.2012.663855] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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22
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Zhao Z, Choi J, Zhao C, Ma ZA. FTY720 normalizes hyperglycemia by stimulating β-cell in vivo regeneration in db/db mice through regulation of cyclin D3 and p57(KIP2). J Biol Chem 2011; 287:5562-73. [PMID: 22194608 DOI: 10.1074/jbc.m111.305359] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Loss of insulin-producing β-cell mass is a hallmark of type 2 diabetes in humans and diabetic db/db mice. Pancreatic β-cells can modulate their mass in response to a variety of physiological and pathophysiological cues. There are currently few effective therapeutic approaches targeting β-cell regeneration although some anti-diabetic drugs may positively affect β-cell mass. Here we show that oral administration of FTY720, a sphingosine 1-phosphate (S1P) receptor modulator, to db/db mice normalizes fasting blood glucose by increasing β-cell mass and blood insulin levels without affecting insulin sensitivity. Fasting blood glucose remained normal in the mice even after the drug was withdrawn after 23 weeks of treatment. The islet area in the pancreases of the FTY720-treated db/db mice was more than 2-fold larger than that of the untreated mice after 6 weeks of treatment. Furthermore, BrdU incorporation assays and Ki67 staining demonstrated cell proliferation in the islets and pancreatic duct areas. Finally, islets from the treated mice exhibited a significant decrease in the level of cyclin-dependent kinase inhibitor p57(KIP2) and an increase in the level of cyclin D3 as compared with those of untreated mice, which could be reversed by the inhibition of phosphatidylinositol 3-kinase (PI3K). Our findings reveal a novel network that controls β-cell regeneration in the obesity-diabetes setting by regulating cyclin D3 and p57(KIP2) expression through the S1P signaling pathway. Therapeutic strategies targeting this network may promote in vivo regeneration of β-cells in patients and prevent and/or cure type 2 diabetes.
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Affiliation(s)
- Zhengshan Zhao
- Division of Experimental Diabetes and Aging, Department of Geriatrics and Palliative Medicine, Mount Sinai School of Medicine, New York, New York 10029, USA
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Zieger MAJ, Gupta MP, Wang M. Proteomic analysis of endothelial cold-adaptation. BMC Genomics 2011; 12:630. [PMID: 22192797 PMCID: PMC3270058 DOI: 10.1186/1471-2164-12-630] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Accepted: 12/22/2011] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Understanding how human cells in tissue culture adapt to hypothermia may aid in developing new clinical procedures for improved ischemic and hypothermic protection. Human coronary artery endothelial cells grown to confluence at 37°C and then transferred to 25°C become resistant over time to oxidative stress and injury induced by 0°C storage and rewarming. This protection correlates with an increase in intracellular glutathione at 25°C. To help understand the molecular basis of endothelial cold-adaptation, isolated proteins from cold-adapted (25°C/72 h) and pre-adapted cells were analyzed by quantitative proteomic methods and differentially expressed proteins were categorized using the DAVID Bioinformatics Resource. RESULTS Cells adapted to 25°C expressed changes in the abundance of 219 unique proteins representing a broad range of categories such as translation, glycolysis, biosynthetic (anabolic) processes, NAD, cytoskeletal organization, RNA processing, oxidoreductase activity, response-to-stress and cell redox homeostasis. The number of proteins that decreased significantly with cold-adaptation exceeded the number that increased by 2:1. Almost half of the decreases were associated with protein metabolic processes and a third were related to anabolic processes including protein, DNA and fatty acid synthesis. Changes consistent with the suppression of cytoskeletal dynamics provided further evidence that cold-adapted cells are in an energy conserving state. Among the specific changes were increases in the abundance and activity of redox proteins glutathione S-transferase, thioredoxin and thioredoxin reductase, which correlated with a decrease in oxidative stress, an increase in protein glutathionylation, and a recovery of reduced protein thiols during rewarming from 0°C. Increases in S-adenosylhomocysteine hydrolase and nicotinamide phosphoribosyltransferase implicate a central role for the methionine-cysteine transulfuration pathway in increasing glutathione levels and the NAD salvage pathway in increasing the reducing capacity of cold-adapted cells. CONCLUSIONS Endothelial adaptation to mild-moderate hypothermia down-regulates anabolic processes and increases the reducing capacity of cells to enhance their resistance to oxidation and injury associated with 0°C storage and rewarming. Inducing these characteristics in a clinical setting could potentially limit the damaging effects of energy insufficiency due to ischemia and prevent the disruption of integrated metabolism at low temperatures.
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Affiliation(s)
- Michael A J Zieger
- Methodist Research Institute, Indiana University Health, Indianapolis, IN 46202, USA.
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Komizu Y, Ueoka H, Goto K, Ueoka R. Remarkable inhibitory effects of hybrid liposomes on growth of human colon cancer cells through induction of cell cycle arrest along with apoptosis. Int J Nanomedicine 2011; 6:1913-20. [PMID: 21931486 PMCID: PMC3173053 DOI: 10.2147/ijn.s24160] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Background Hybrid liposomes can be prepared by simply sonicating a mixture of vesicular and micellar molecules in buffer solutions. In this study, we investigated the effects of hybrid liposomes on the growth of human colon cancer cells in vitro. Methods Hybrid liposomes (HL-n, n = 21, 23, 25) composed of L-α-dimyristoylphosphatidylcholine (DMPC) and polyoxyethylene(n) dodecyl ethers (C12(EO)n, n = 21, 23, 25) were prepared by the sonication method and their inhibitory effects on growth of human colon cancer HCT116 cells were examined in vitro. Results Significant growth inhibition of HCT116 cells was observed in the presence of HL-n. The fifty percent inhibitory concentration (IC50) of HL-n was less than half that of DMPC liposomes. Furthermore, fluorescence microscopic and flow cytometric analyses indicated that the markedly inhibitory effects of HL-n on the growth of HCT116 cells could be attained through the induction of cell cycle arrest at the G0/G1 phase along with apoptotic cell death. Conclusion It was found for the first time that HL-n can induce both cell cycle arrest and apoptosis in colon cancer cells. The findings in this study should contribute to novel chemotherapy for colon cancer.
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Affiliation(s)
- Yuji Komizu
- Division of Applied Life Science, Graduate School of Engineering, Sojo University, Ikeda, Kumamoto, Japan
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Kim YM, Lee YM, Park SY, Pyo H. Ataxia Telangiectasia and Rad3-Related Overexpressing Cancer Cells Induce Prolonged G2 Arrest and Develop Resistance to Ionizing Radiation. DNA Cell Biol 2011; 30:219-27. [DOI: 10.1089/dna.2010.1141] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Affiliation(s)
- Young-Mee Kim
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
- Research Institute and Hospital, National Cancer Center, Goyang, Gyeonggi, Republic of Korea
| | - Yeo Myoung Lee
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
- Research Institute and Hospital, National Cancer Center, Goyang, Gyeonggi, Republic of Korea
| | - Soo-Yeon Park
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
- Research Institute and Hospital, National Cancer Center, Goyang, Gyeonggi, Republic of Korea
| | - Hongryull Pyo
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
- Research Institute and Hospital, National Cancer Center, Goyang, Gyeonggi, Republic of Korea
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ATR (ataxia telangiectasia mutated- and Rad3-related kinase) is activated by mild hypothermia in mammalian cells and subsequently activates p53. Biochem J 2011; 435:499-508. [DOI: 10.1042/bj20101303] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In vitro cultured mammalian cells respond to mild hypothermia (27–33 °C) by attenuating cellular processes and slowing and arresting the cell cycle. The slowing of the cell cycle at the upper range (31–33 °C) and its complete arrest at the lower range (27–28 °C) of mild hypothermia is effected by the activation of p53 and subsequent expression of p21. However, the mechanism by which cold is perceived in mammalian cells with the subsequent activation of p53 has remained undetermined. In the present paper, we report that the exposure of Chinese-hamster ovary-K1 cells to mildly hypothermic conditions activates the ATR (ataxia telangiectasia mutated- and Rad3-related kinase)–p53–p21 signalling pathway and is thus a key pathway involved in p53 activation upon mild hypothermia. In addition, we show that although p38MAPK (p38 mitogen-activated protein kinase) is also involved in activation of p53 upon mild hypothermia, this is probably the result of activation of p38MAPK by ATR. Furthermore, we show that cold-induced changes in cell membrane lipid composition are correlated with the activation of the ATR–p53–p21 pathway. Therefore we provide the first mechanistic detail of cell sensing and signalling upon mild hypothermia in mammalian cells leading to p53 and p21 activation, which is known to lead to cell cycle arrest.
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Zhao Z, Zhang X, Zhao C, Choi J, Shi J, Song K, Turk J, Ma ZA. Protection of pancreatic beta-cells by group VIA phospholipase A(2)-mediated repair of mitochondrial membrane peroxidation. Endocrinology 2010; 151:3038-48. [PMID: 20463052 PMCID: PMC2903934 DOI: 10.1210/en.2010-0016] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Mitochondrial production of reactive oxygen species and oxidation of cardiolipin are key events in initiating apoptosis. We reported that group VIA Ca(2+)-independent phospholipase A(2) (iPLA(2)beta) localizes in and protects beta-cell mitochondria from oxidative damage during staurosporine-induced apoptosis. Here, we used iPLA(2)beta-null (iPLA(2)beta(-/-)) mice to investigate the role of iPLA(2)beta in the repair of mitochondrial membranes. We show that islets isolated from iPLA(2)beta(-/-) mice are more sensitive to staurosporine-induced apoptosis than those from wild-type littermates and that 2 wk of daily ip administration of staurosporine to iPLA(2)beta(-/-) mice impairs both the animals' glucose tolerance and glucose-stimulated insulin secretion by their pancreatic islets. Moreover, the iPLA(2)beta inhibitor bromoenol lactone caused mitochondrial membrane peroxidation and cytochrome c release, and these effects were reversed by N-acetyl cysteine. The mitochondrial antioxidant N-t-butyl hydroxylamine blocked staurosporine-induced cytochrome c release and caspase-3 activation in iPLA(2)beta(-/-) islets. Furthermore, the collapse of mitochondrial membrane potential in INS-1 insulinoma cells caused by high glucose and fatty acid levels was attenuated by overexpressing iPLA(2)beta. Interestingly, iPLA(2)beta was expressed only at low levels in islet beta-cells from obesity- and diabetes-prone db/db mice. These findings support the hypothesis that iPLA(2)beta is important in repairing oxidized mitochondrial membrane components (e.g. cardiolipin) and that this prevents cytochrome c release in response to stimuli that otherwise induce apoptosis. The low iPLA(2)beta expression level in db/db mouse beta-cells may render them vulnerable to injury by reactive oxygen species.
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Affiliation(s)
- Zhengshan Zhao
- Division of Experimental Diabetes and Aging, Department of Geriatrics and Adult Development, One Gustave L. Levy Place, Mount Sinai School of Medicine, New York, NY 10029, USA
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Sun B, Zhang X, Yonz C, Cummings BS. Inhibition of calcium-independent phospholipase A2 activates p38 MAPK signaling pathways during cytostasis in prostate cancer cells. Biochem Pharmacol 2010; 79:1727-35. [PMID: 20171194 DOI: 10.1016/j.bcp.2010.02.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2009] [Revised: 02/03/2010] [Accepted: 02/05/2010] [Indexed: 11/19/2022]
Abstract
The p38 mitogen-activated protein kinase (MAPK) signaling pathways activated during cytostasis induced by Ca(2+)-independent phospholipase A2 (iPLA2) inhibition in prostate cancer cells were investigated. iPLA2 inhibition using siRNA, or the selective inhibitor bromoenol lactone (BEL) and it's enantiomers, decreased growth in LNCaP (p53 positive) and PC-3 (p53 negative) human prostate cancer cells. Decreased cell growth correlated to time- and concentration-dependent activation of the mitogen-activated protein kinase p38 in both cell lines. Inhibition of cytosolic iPLA(2)beta using S-BEL, induced significantly higher levels of P-p53, p53, p21 and P-p38 expression than inhibition of microsomal iPLA2 gamma using R-BEL. Inhibition of p38 using SB202190 or SB203580 inhibited BEL-induced increases in P-p53 (ser15), p53 and p21, and altered the number of cells in G1 in LNCaP cells, and S-phase in PC-3 cells. BEL treatment also induced reactive species in PC-3 and LNCaP cells, which was partially reversed by pretreatment with N-acetyl-cysteine (NAC). NAC subsequently inhibited BEL-induced activation of p38 and p53 in LNCaP cells. In addition, treatment of cells with NAC partially reversed the effect of BEL on cell growth and preserved cell morphology. Collectively, these data demonstrate the novel findings that iPLA2 inhibition activates p38 by inducing reactive species, and further suggest that this signaling kinase is involved in p53 activation, cell cycle arrest and cytostasis.
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Affiliation(s)
- Bin Sun
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, GA 30602, United States
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Abdel-Malek ZA, Kadekaro AL, Swope VB. Stepping up melanocytes to the challenge of UV exposure. Pigment Cell Melanoma Res 2010; 23:171-86. [PMID: 20128873 DOI: 10.1111/j.1755-148x.2010.00679.x] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Exposure to solar ultraviolet radiation (UV) is the main etiological factor for skin cancer, including melanoma. Cutaneous pigmentation, particularly eumelanin, afforded by melanocytes is the main photoprotective mechanism, as it prevents UV-induced DNA damage in the epidermis. Therefore, maintaining genomic stability of melanocytes is crucial for prevention of melanoma, as well as keratinocyte-derived basal and squamous cell carcinoma. A critical independent factor for preventing melanoma is DNA repair capacity. The response of melanocytes to UV is mediated mainly by a network of paracrine factors that not only activate melanogenesis, but also DNA repair, anti-oxidant, and survival pathways that are pivotal for maintenance of genomic stability and prevention of malignant transformation or apoptosis. However, little is known about the stress response of melanocytes to UV and the regulation of DNA repair pathways in melanocytes. Unraveling these mechanisms might lead to strategies to prevent melanoma, as well as non-melanoma skin cancer.
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Affiliation(s)
- Zalfa A Abdel-Malek
- Department of Dermatology, University of Cincinnati Collage of Medicine, Cincinnati, OH, USA.
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Lei X, Barbour SE, Ramanadham S. Group VIA Ca2+-independent phospholipase A2 (iPLA2beta) and its role in beta-cell programmed cell death. Biochimie 2010; 92:627-37. [PMID: 20083151 DOI: 10.1016/j.biochi.2010.01.005] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2009] [Accepted: 01/11/2010] [Indexed: 01/09/2023]
Abstract
Activation of phospholipases A(2) (PLA(2)s) leads to the generation of biologically active lipid mediators that can affect numerous cellular events. The Group VIA Ca(2+)-independent PLA(2), designated iPLA(2)beta, is active in the absence of Ca(2+), activated by ATP, and inhibited by the bromoenol lactone suicide inhibitor (BEL). Over the past 10-15 years, studies using BEL have demonstrated that iPLA(2)beta participates in various biological processes and the recent availability of mice in which iPLA(2)beta expression levels have been genetically-modified are extending these findings. Work in our laboratory suggests that iPLA(2)beta activates a unique signaling cascade that promotes beta-cell apoptosis. This pathway involves iPLA(2)beta dependent induction of neutral sphingomyelinase, production of ceramide, and activation of the intrinsic pathway of apoptosis. There is a growing body of literature supporting beta-cell apoptosis as a major contributor to the loss of beta-cell mass associated with the onset and progression of Type 1 and Type 2 diabetes mellitus. This underscores a need to gain a better understanding of the molecular mechanisms underlying beta-cell apoptosis so that improved treatments can be developed to prevent or delay the onset and progression of diabetes mellitus. Herein, we offer a general review of Group VIA Ca(2+)-independent PLA(2) (iPLA(2)beta) followed by a more focused discussion of its participation in beta-cell apoptosis. We suggest that iPLA(2)beta-derived products trigger pathways which can lead to beta-cell apoptosis during the development of diabetes.
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Affiliation(s)
- Xiaoyong Lei
- Department of Medicine, Mass Spectrometry Resource and Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine, St. Louis, MO 63110, USA
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31
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Herbert SP, Odell AF, Ponnambalam S, Walker JH. Activation of cytosolic phospholipase A2-{alpha} as a novel mechanism regulating endothelial cell cycle progression and angiogenesis. J Biol Chem 2009; 284:5784-96. [PMID: 19119141 DOI: 10.1074/jbc.m807282200] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Release of endothelial cells from contact-inhibition and cell cycle re-entry is required for the induction of new blood vessel formation by angiogenesis. Using a combination of chemical inhibition, loss of function, and gain of function approaches, we demonstrate that endothelial cell cycle re-entry, S phase progression, and subsequent angiogenic tubule formation are dependent upon the activity of cytosolic phospholipase A(2)-alpha (cPLA(2)alpha). Inhibition of cPLA(2)alpha activity and small interfering RNA (siRNA)-mediated knockdown of endogenous cPLA(2)alpha reduced endothelial cell proliferation. In the absence of cPLA(2)alpha activity, endothelial cells exhibited retarded progression from G(1) through S phase, displayed reduced cyclin A/cdk2 expression, and generated less arachidonic acid. In quiescent endothelial cells, cPLA(2)alpha is inactivated upon its sequestration at the Golgi apparatus. Upon the stimulation of endothelial cell proliferation, activation of cPLA(2)alpha by release from the Golgi apparatus was critical to the induction of cyclin A expression and efficient cell cycle progression. Consequently, inhibition of cPLA(2)alpha was sufficient to block angiogenic tubule formation in vitro. Furthermore, the siRNA-mediated retardation of endothelial cell cycle re-entry and proliferation was reversed upon overexpression of an siRNA-resistant form of cPLA(2)alpha. Thus, activation of cPLA(2)alpha acts as a novel mechanism for the regulation of endothelial cell cycle re-entry, cell cycle progression, and angiogenesis.
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Affiliation(s)
- Shane P Herbert
- Endothelial Cell Biology Unit, Institute of Molecular and Cellular Biology, Leeds Institute of Genetics, Health, and Therapeutics, University of Leeds, Leeds LS2 9JT, United Kingdom
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Roobol A, Carden MJ, Newsam RJ, Smales CM. Biochemical insights into the mechanisms central to the response of mammalian cells to cold stress and subsequent rewarming. FEBS J 2008; 276:286-302. [PMID: 19054067 DOI: 10.1111/j.1742-4658.2008.06781.x] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Mammalian cells cultured in vitro are able to recover from cold stress. However, the mechanisms activated during cold stress and recovery are still being determined. We here report the effects of hypothermia on cellular architecture, cell cycle progression, mRNA stability, protein synthesis and degradation in three mammalian cell lines. The cellular structures examined were, in general, well maintained during mild hypothermia (27-32 degrees C) but became increasingly disrupted at low temperatures (4-10 degrees C). The degradation rates of all mRNAs and proteins examined were much reduced at 27 degrees C, and overall protein synthesis rates were gradually reduced with temperature down to 20 degrees C. Proteins involved in a range of cellular activities were either upregulated or downregulated at 32 and 27 degrees C during cold stress and recovery. Many of these proteins were molecular chaperones, but they did not include the inducible heat shock protein Hsp72. Further detailed investigation of specific proteins revealed that the responses to cold stress and recovery are at least partially controlled by modulation of p53, Grp75 and eIF3i levels. Furthermore, under conditions of severe cold stress (4 degrees C), lipid-containing structures were observed that appeared to be in the process of being secreted from the cell that were not observed at less severe cold stress temperatures. Our findings shed light on the mechanisms involved and activated in mammalian cells upon cold stress and recovery.
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Affiliation(s)
- Anne Roobol
- Protein Science Group, Department of Biosciences, University of Kent, Canterbury, UK
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Hooks SB, Cummings BS. Role of Ca2+-independent phospholipase A2 in cell growth and signaling. Biochem Pharmacol 2008; 76:1059-67. [PMID: 18775417 DOI: 10.1016/j.bcp.2008.07.044] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2008] [Revised: 07/15/2008] [Accepted: 07/15/2008] [Indexed: 01/25/2023]
Abstract
Phospholipase A(2) (PLA(2)) are esterases that cleave glycerophospholipids to release fatty acids and lysophospholipids. Several studies demonstrate that PLA(2) regulate growth and signaling in several cell types. However, few of these studies have focused on Ca2+-independent phospholipase A(2) (iPLA(2) or Group VI PLA(2)). This class of PLA(2) was originally suggested to mediate phospholipid remodeling in several cell types including macrophages. As such, it was labeled as a housekeeping protein and thought not to play as significant of roles in cell growth as its older counterparts cytosolic PLA(2) (cPLA(2) or Group IV PLA(2)) and secretory PLA(2) (sPLA(2) or Groups I-III, V and IX-XIV PLA(2)). However, several recent studies demonstrate that iPLA(2) mediate cell growth, and do so by participating in signal transduction pathways that include epidermal growth factor receptors (EGFR), mitogen activated protein kinases (MAPK), mdm2, and even the tumor suppressor protein p53 and the cell cycle regulator p21. The exact mechanism by which iPLA(2) mediates these pathways are not known, but likely involve the generation of lipid signals such as arachidonic acid, lysophosphatidic acid (LPA) and lysophosphocholines (LPC). This review discusses the role of iPLA(2) in cell growth with special emphasis placed on their role in cell signaling. The putative lipid signals involved are also discussed.
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Affiliation(s)
- Shelley B Hooks
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, GA 30602, USA
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Zeng L, Wu GZ, Goh KJ, Lee YM, Ng CC, You AB, Wang J, Jia D, Hao A, Yu Q, Li B. Saturated fatty acids modulate cell response to DNA damage: implication for their role in tumorigenesis. PLoS One 2008; 3:e2329. [PMID: 18523653 PMCID: PMC2402972 DOI: 10.1371/journal.pone.0002329] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2007] [Accepted: 04/24/2008] [Indexed: 12/02/2022] Open
Abstract
DNA damage triggers a network of signaling events that leads to cell cycle arrest or apoptosis. This DNA damage response acts as a mechanism to prevent cancer development. It has been reported that fatty acids (FAs) synthesis is increased in many human tumors while inhibition of fatty acid synthase (FASN) could suppress tumor growth. Here we report that saturated fatty acids (SFAs) play a negative role in DNA damage response. Palmitic acid, as well as stearic acid and myristic acid, compromised the induction of p21 and Bax expression in response to double stranded breaks and ssDNA, while inhibition or knockdown of FASN enhanced these cellular events. SFAs appeared to regulate p21 and Bax expression via Atr-p53 dependent and independent pathways. These effects were only observed in primary mouse embryonic fibroblasts and osteoblasts, but not in immortalized murine NIH3T3, or transformed HCT116 and MCF-7 cell lines. Accordingly, SFAs showed some positive effects on proliferation of MEFs in response to DNA damage. These results suggest that SFAs, by negatively regulating the DNA damage response pathway, might promote cell transformation, and that increased synthesis of SFAs in precancer/cancer cells might contribute to tumor progression and drug resistance.
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Affiliation(s)
- Li Zeng
- Cancer and Developmental Biology Division, Institute of Molecular and Cell Biology, Singapore, Republic of Singapore
| | - Guang-Zhi Wu
- Cancer and Developmental Biology Division, Institute of Molecular and Cell Biology, Singapore, Republic of Singapore
- China-Japan Union Hospital, Jilin University, Changchun, Jilin, People's Republic of China
| | - Kim Jee Goh
- Cancer and Developmental Biology Division, Institute of Molecular and Cell Biology, Singapore, Republic of Singapore
| | - Yew Mun Lee
- Cancer and Developmental Biology Division, Institute of Molecular and Cell Biology, Singapore, Republic of Singapore
| | - Chuo Chung Ng
- Cancer and Developmental Biology Division, Institute of Molecular and Cell Biology, Singapore, Republic of Singapore
| | - Ang Ben You
- Cancer and Developmental Biology Division, Institute of Molecular and Cell Biology, Singapore, Republic of Singapore
| | - Jianhe Wang
- Cancer and Developmental Biology Division, Institute of Molecular and Cell Biology, Singapore, Republic of Singapore
| | - Deyong Jia
- The Key Laboratory of Experimental Teratology, Ministry of Education, Faculty of Medicine, Shandong University, Jinan, Shandong, People's Republic of China
| | - Aijun Hao
- The Key Laboratory of Experimental Teratology, Ministry of Education, Faculty of Medicine, Shandong University, Jinan, Shandong, People's Republic of China
| | - Qiang Yu
- Laboratory of Molecular Pharmacology, Genome Institute of Singapore, Singapore, Republic of Singapore
| | - Baojie Li
- Cancer and Developmental Biology Division, Institute of Molecular and Cell Biology, Singapore, Republic of Singapore
- * E-mail:
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