1
|
Cook I, Leyh TS. Sterol-activated amyloid beta fibril formation. J Biol Chem 2023; 299:105445. [PMID: 37949224 PMCID: PMC10704437 DOI: 10.1016/j.jbc.2023.105445] [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: 08/27/2023] [Revised: 10/23/2023] [Accepted: 11/03/2023] [Indexed: 11/12/2023] Open
Abstract
The metabolic processes that link Alzheimer's disease (AD) to elevated cholesterol levels in the brain are not fully defined. Amyloid beta (Aβ) plaque accumulation is believed to begin decades prior to symptoms and to contribute significantly to the disease. Cholesterol and its metabolites accelerate plaque formation through as-yet-undefined mechanisms. Here, the mechanism of cholesterol (CH) and cholesterol 3-sulfate (CS) induced acceleration of Aβ42 fibril formation is examined in quantitative ligand binding, Aβ42 fibril polymerization, and molecular dynamics studies. Equilibrium and pre-steady-state binding studies reveal that monomeric Aβ42•ligand complexes form and dissociate rapidly relative to oligomerization, that the ligand/peptide stoichiometry is 1-to-1, and that the peptide is likely saturated in vivo. Analysis of Aβ42 polymerization progress curves demonstrates that ligands accelerate polymer synthesis by catalyzing the conversion of peptide monomers into dimers that nucleate the polymerization reaction. Nucleation is accelerated ∼49-fold by CH, and ∼13,000-fold by CS - a minor CH metabolite. Polymerization kinetic models predict that at presumed disease-relevant CS and CH concentrations, approximately half of the polymerization nuclei will contain CS, small oligomers of neurotoxic dimensions (∼12-mers) will contain substantial CS, and fibril-formation lag times will decrease 13-fold relative to unliganded Aβ42. Molecular dynamics models, which quantitatively predict all experimental findings, indicate that the acceleration mechanism is rooted in ligand-induced stabilization of the peptide in non-helical conformations that readily form polymerization nuclei.
Collapse
Affiliation(s)
- Ian Cook
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Thomas S Leyh
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA.
| |
Collapse
|
2
|
A Comprehensive Metabolomics Analysis of Fecal Samples from Advanced Adenoma and Colorectal Cancer Patients. Metabolites 2022; 12:metabo12060550. [PMID: 35736483 PMCID: PMC9229737 DOI: 10.3390/metabo12060550] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Revised: 06/08/2022] [Accepted: 06/14/2022] [Indexed: 12/14/2022] Open
Abstract
Accurate diagnosis of colorectal cancer (CRC) still relies on invasive colonoscopy. Noninvasive methods are less sensitive in detecting the disease, particularly in the early stage. In the current work, a metabolomics analysis of fecal samples was carried out by ultra-high-performance liquid chromatography–tandem mass spectroscopy (UPLC-MS/MS). A total of 1380 metabolites were analyzed in a cohort of 120 fecal samples from patients with normal colonoscopy, advanced adenoma (AA) and CRC. Multivariate analysis revealed that metabolic profiles of CRC and AA patients were similar and could be clearly separated from control individuals. Among the 25 significant metabolites, sphingomyelins (SM), lactosylceramides (LacCer), secondary bile acids, polypeptides, formiminoglutamate, heme and cytidine-containing pyrimidines were found to be dysregulated in CRC patients. Supervised random forest (RF) and logistic regression algorithms were employed to build a CRC accurate predicted model consisting of the combination of hemoglobin (Hgb) and bilirubin E,E, lactosyl-N-palmitoyl-sphingosine, glycocholenate sulfate and STLVT with an accuracy, sensitivity and specificity of 91.67% (95% Confidence Interval (CI) 0.7753–0.9825), 0.7 and 1, respectively.
Collapse
|
3
|
Johnson CH, Santidrian AF, LeBoeuf SE, Kurczy ME, Rattray NJW, Rattray Z, Warth B, Ritland M, Hoang LT, Loriot C, Higa J, Hansen JE, Felding BH, Siuzdak G. Metabolomics guided pathway analysis reveals link between cancer metastasis, cholesterol sulfate, and phospholipids. Cancer Metab 2017; 5:9. [PMID: 29093815 PMCID: PMC5663111 DOI: 10.1186/s40170-017-0171-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 10/06/2017] [Indexed: 01/02/2023] Open
Abstract
Background Cancer cells that enter the metastatic cascade require traits that allow them to survive within the circulation and colonize distant organ sites. As disseminating cancer cells adapt to their changing microenvironments, they also modify their metabolism and metabolite production. Methods A mouse xenograft model of spontaneous tumor metastasis was used to determine the metabolic rewiring that occurs between primary cancers and their metastases. An “autonomous” mass spectrometry-based untargeted metabolomic workflow with integrative metabolic pathway analysis revealed a number of differentially regulated metabolites in primary mammary fat pad (MFP) tumors compared to microdissected paired lung metastases. The study was further extended to analyze metabolites in paired normal tissues which determined the potential influence of metabolites from the microenvironment. Results Metabolomic analysis revealed that multiple metabolites were increased in metastases, including cholesterol sulfate and phospholipids (phosphatidylglycerols and phosphatidylethanolamine). Metabolite analysis of normal lung tissue in the mouse model also revealed increased levels of these metabolites compared to tissues from normal MFP and primary MFP tumors, indicating potential extracellular uptake by cancer cells in lung metastases. These results indicate a potential functional importance of cholesterol sulfate and phospholipids in propagating metastasis. In addition, metabolites involved in DNA/RNA synthesis and the TCA cycle were decreased in lung metastases compared to primary MFP tumors. Conclusions Using an integrated metabolomic workflow, this study identified a link between cholesterol sulfate and phospholipids, metabolic characteristics of the metastatic niche, and the capacity of tumor cells to colonize distant sites. Electronic supplementary material The online version of this article (10.1186/s40170-017-0171-2) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Caroline H Johnson
- Scripps Center for Metabolomics, The Scripps Research Institute, La Jolla, CA USA.,Department of Environmental Health Sciences, Yale School of Public HealthYale School of Medicine, New Haven, CT USA.,Yale Cancer Center, Yale School of Medicine, New Haven, CT USA
| | - Antonio F Santidrian
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA USA.,Current address: Department of Molecular Oncology and Immunotherapies, StemImmune, Inc., San Diego, CA 92122 USA
| | - Sarah E LeBoeuf
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA USA.,Current address: NYU Langone Medical Center, New York, NY 10016 USA
| | - Michael E Kurczy
- Scripps Center for Metabolomics, The Scripps Research Institute, La Jolla, CA USA.,Current address: CVMD IMED AstraZeneca, Gothenburg, Sweden
| | - Nicholas J W Rattray
- Department of Environmental Health Sciences, Yale School of Public HealthYale School of Medicine, New Haven, CT USA
| | - Zahra Rattray
- Department of Therapeutic Radiology, Yale School of Medicine, Yale University, New Haven, CT 06520 USA
| | - Benedikt Warth
- Scripps Center for Metabolomics, The Scripps Research Institute, La Jolla, CA USA
| | - Melissa Ritland
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA USA.,Current address: Active Motif Inc, Carlsbad, CA 92008 USA
| | - Linh T Hoang
- Scripps Center for Metabolomics, The Scripps Research Institute, La Jolla, CA USA
| | - Celine Loriot
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA USA
| | - Jason Higa
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA USA
| | - James E Hansen
- Yale Cancer Center, Yale School of Medicine, New Haven, CT USA.,Department of Therapeutic Radiology, Yale School of Medicine, Yale University, New Haven, CT 06520 USA
| | - Brunhilde H Felding
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA USA
| | - Gary Siuzdak
- Scripps Center for Metabolomics, The Scripps Research Institute, La Jolla, CA USA
| |
Collapse
|
4
|
Lanzini J, Dargère D, Regazzetti A, Tebani A, Laprévote O, Auzeil N. Changing in lipid profile induced by the mutation of Foxn1 gene: A lipidomic analysis of Nude mice skin. Biochimie 2015; 118:234-43. [PMID: 26427556 DOI: 10.1016/j.biochi.2015.09.029] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 09/23/2015] [Indexed: 10/23/2022]
Abstract
Nude mice carry a spontaneous mutation affecting the gene Foxn1 mainly expressed in the epidermis. This gene is involved in several skin functions, especially in the proliferation and the differentiation of keratinocytes which are key cells of epithelial barrier. The skin, a protective barrier for the body, is essentially composed of lipids. Taking into account these factors, we conducted a lipidomic study to search for any changes in lipid composition of skin possibly related to Foxn1 mutation. Lipids were extracted from skin biopsies of Nude and BALB/c mice to be analyzed by liquid chromatography coupled to a high resolution mass spectrometer (HRMS). Multivariate and univariate data analyses were carried out to compare lipid extracts. Identification was performed using HRMS data, retention time and mass spectrometry fragmentation study. These results indicate that mutation of Foxn1 leads to significant modifications in the lipidome in Nude mice skin. An increase in cholesterol sulfate, phospholipids, sphingolipids and fatty acids associated with a decrease in glycerolipids suggest that the lipidome in mice skin is regulated by the Foxn1 gene.
Collapse
Affiliation(s)
- Justine Lanzini
- UMR CNRS 8638, Faculté de Pharmacie, Université Paris Descartes, 4 Avenue de L'Observatoire, 75006 Paris, France
| | - Delphine Dargère
- UMR CNRS 8638, Faculté de Pharmacie, Université Paris Descartes, 4 Avenue de L'Observatoire, 75006 Paris, France
| | - Anne Regazzetti
- UMR CNRS 8638, Faculté de Pharmacie, Université Paris Descartes, 4 Avenue de L'Observatoire, 75006 Paris, France
| | - Abdellah Tebani
- UMR CNRS 8638, Faculté de Pharmacie, Université Paris Descartes, 4 Avenue de L'Observatoire, 75006 Paris, France
| | - Olivier Laprévote
- UMR CNRS 8638, Faculté de Pharmacie, Université Paris Descartes, 4 Avenue de L'Observatoire, 75006 Paris, France; AP-HP, Service de Toxicologie Biologique, Hôpital Lariboisière, 4 Rue Ambroise Paré, 75475 Paris Cedex 10, France
| | - Nicolas Auzeil
- UMR CNRS 8638, Faculté de Pharmacie, Université Paris Descartes, 4 Avenue de L'Observatoire, 75006 Paris, France.
| |
Collapse
|
5
|
Takekoshi S, Kitatani K, Yamamoto Y. Roles of Oxidized Diacylglycerol for Carbon Tetrachloride-induced Liver Injury and Fibrosis in Mouse. Acta Histochem Cytochem 2014; 47:185-94. [PMID: 25861124 PMCID: PMC4387239 DOI: 10.1267/ahc.14030] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 06/20/2014] [Indexed: 01/22/2023] Open
Abstract
Since there is a report that an inhibitor of protein kinase C (PKC) effectively suppresses the development of hepatic fibrosis, it is suggested that the PKC signaling pathway plays an important role in the pathogenesis of hepatic fibrosis. We reported that oxidized diacylglycerol (DAG), which is an activator of PKC, had a remarkably stronger PKC-activating action than un-oxidized DAG. In the present study, we explored the roles of oxidized DAG in hepatic fibrogenesis using mice, the livers of which developed fibrosis by long-term administration of carbon tetrachloride (CCl4). Liver fibrosis models were created by 4- or 8-week repetitive subcutaneous injections of CCl4 to the backs of C57BL/6J mice. The amount of oxidized DAG was significantly increased in the CCl4-treated group. Moreover, it was found that PKCα, βI, βII and δ were activated. In the CCl4-treated group, phosphorylation of ERK and JNK, which are downstream signal transmitters in the PKC pathway, was increased. It was also found in this group that there was an increase in TIMP-1, which is a fibrogenesis-promoting factor whose expression is enhanced by activated JNK, and of TNF-α, an inflammatory cytokine. Analysis by quantitative real-time RT-PCR showed that expressions of αSMA, collagen I, TNF-α and IL-10 were remarkably increased in the 8-week CCl4-treated group. The above results strongly suggested that oxidized DAG, which is increased by augmented oxidative stress, activated PKCα, βI, βII and δ molecular species and that these molecular species in turn stimulated the phosphorylation of MAP kinases including ERK and JNK, resulting in enhancement of hepatic fibrogenesis.
Collapse
Affiliation(s)
- Susumu Takekoshi
- Department of Cell Biology, Division of Host Defense Mechanism, Tokai University School of Medicine
| | - Kanae Kitatani
- Department of Cell Biology, Division of Host Defense Mechanism, Tokai University School of Medicine
| | - Yorihiro Yamamoto
- School of Bioscience and Biotechnology, Tokyo University of Technology
| |
Collapse
|
6
|
Elias PM, Williams ML, Choi EH, Feingold KR. Role of cholesterol sulfate in epidermal structure and function: lessons from X-linked ichthyosis. Biochim Biophys Acta Mol Cell Biol Lipids 2013; 1841:353-61. [PMID: 24291327 DOI: 10.1016/j.bbalip.2013.11.009] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Revised: 11/13/2013] [Accepted: 11/20/2013] [Indexed: 02/07/2023]
Abstract
X-linked ichthyosis is a relatively common syndromic form of ichthyosis most often due to deletions in the gene encoding the microsomal enzyme, steroid sulfatase, located on the short area of the X chromosome. Syndromic features are mild or unapparent unless contiguous genes are affected. In normal epidermis, cholesterol sulfate is generated by cholesterol sulfotransferase (SULT2B1b), but desulfated in the outer epidermis, together forming a 'cholesterol sulfate cycle' that potently regulates epidermal differentiation, barrier function and desquamation. In XLI, cholesterol sulfate levels my exceed 10% of total lipid mass (≈1% of total weight). Multiple cellular and biochemical processes contribute to the pathogenesis of the barrier abnormality and scaling phenotype in XLI. This article is part of a Special Issue entitled The Important Role of Lipids in the Epidermis and their Role in the Formation and Maintenance of the Cutaneous Barrier. Guest Editors: Kenneth R. Feingold and Peter Elias.
Collapse
Affiliation(s)
- Peter M Elias
- Dermatology Service, Department of Veterans Affairs Medical Center, and Department of Dermatology, University of California, San Francisco, CA USA.
| | - Mary L Williams
- Departments of Dermatology and Pediatrics, University of California, San Francisco, CA USA
| | - Eung-Ho Choi
- Department of Dermatology, Yonsei University, Wonju College of Medicine, Wonju, South Korea
| | - Kenneth R Feingold
- Medical Service, Department of Veterans Affairs Medical Center, and Department of Medicine, University of California, San Francisco, CA, USA
| |
Collapse
|
7
|
The retinoid-related orphan receptor RORα promotes keratinocyte differentiation via FOXN1. PLoS One 2013; 8:e70392. [PMID: 23922987 PMCID: PMC3726659 DOI: 10.1371/journal.pone.0070392] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Accepted: 06/21/2013] [Indexed: 01/16/2023] Open
Abstract
RORα is a retinoid-related orphan nuclear receptor that regulates inflammation, lipid metabolism, and cellular differentiation of several non-epithelial tissues. In spite of its high expression in skin epithelium, its functions in this tissue remain unclear. Using gain- and loss-of-function approaches to alter RORα gene expression in human keratinocytes (HKCs), we have found that this transcription factor functions as a regulator of epidermal differentiation. Among the 4 RORα isoforms, RORα4 is prominently expressed by keratinocytes in a manner that increases with differentiation. In contrast, RORα levels are significantly lower in skin squamous cell carcinoma tumors (SCCs) and cell lines. Increasing the levels of RORα4 in HKCs enhanced the expression of structural proteins associated with early and late differentiation, as well as genes involved in lipid barrier formation. Gene silencing of RORα impaired the ability of keratinocytes to differentiate in an in vivo epidermal cyst model. The pro-differentiation function of RORα is mediated at least in part by FOXN1, a well-known pro-differentiation transcription factor that we establish as a novel direct target of RORα in keratinocytes. Our results point to RORα as a novel node in the keratinocyte differentiation network and further suggest that the identification of RORα ligands may prove useful for treating skin disorders that are associated with abnormal keratinocyte differentiation, including cancer.
Collapse
|
8
|
Huang W, Bansode RR, Xie Y, Rowland L, Mehta M, Davidson NO, Mehta KD. Disruption of the murine protein kinase Cbeta gene promotes gallstone formation and alters biliary lipid and hepatic cholesterol metabolism. J Biol Chem 2011; 286:22795-805. [PMID: 21550971 PMCID: PMC3123047 DOI: 10.1074/jbc.m111.250282] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Revised: 05/04/2011] [Indexed: 12/16/2022] Open
Abstract
The protein kinase C (PKC) family of Ca(2+) and/or lipid-activated serine-threonine protein kinases is implicated in the pathogenesis of obesity and insulin resistance. We recently reported that protein kinase Cβ (PKCβ), a calcium-, diacylglycerol-, and phospholipid-dependent kinase, is critical for maintaining whole body triglyceride homeostasis. We now report that PKCβ deficiency has profound effects on murine hepatic cholesterol metabolism, including hypersensitivity to diet-induced gallstone formation. The incidence of gallstones increased from 9% in control mice to 95% in PKCβ(-/-) mice. Gallstone formation in the mutant mice was accompanied by hyposecretion of bile acids with no alteration in fecal bile acid excretion, increased biliary cholesterol saturation and hydrophobicity indices, as well as hepatic p42/44(MAPK) activation, all of which enhance susceptibility to gallstone formation. Lithogenic diet-fed PKCβ(-/-) mice also displayed decreased expression of hepatic cholesterol-7α-hydroxylase (CYP7A1) and sterol 12α-hydroxylase (CYP8b1). Finally, feeding a modified lithogenic diet supplemented with milk fat, instead of cocoa butter, both increased the severity of and shortened the interval for gallstone formation in PKCβ(-/-) mice and was associated with dramatic increases in cholesterol saturation and hydrophobicity indices. Taken together, the findings reveal a hitherto unrecognized role of PKCβ in fine tuning diet-induced cholesterol and bile acid homeostasis, thus identifying PKCβ as a major physiological regulator of both triglyceride and cholesterol homeostasis.
Collapse
Affiliation(s)
- Wei Huang
- From the Department of Molecular and Cellular Biochemistry, The Dorothy M. Davis Heart and Lung Research Institute, and
| | - Rishipal R. Bansode
- From the Department of Molecular and Cellular Biochemistry, The Dorothy M. Davis Heart and Lung Research Institute, and
| | - Yan Xie
- the Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Leslie Rowland
- From the Department of Molecular and Cellular Biochemistry, The Dorothy M. Davis Heart and Lung Research Institute, and
| | - Madhu Mehta
- the Department of Medicine, The Ohio State University College of Medicine, Columbus, Ohio 43210 and
| | - Nicholas O. Davidson
- the Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Kamal D. Mehta
- From the Department of Molecular and Cellular Biochemistry, The Dorothy M. Davis Heart and Lung Research Institute, and
| |
Collapse
|
9
|
Desorption electrospray ionization mass spectrometry for lipid characterization and biological tissue imaging. Biochim Biophys Acta Mol Cell Biol Lipids 2011; 1811:946-60. [PMID: 21645635 DOI: 10.1016/j.bbalip.2011.05.006] [Citation(s) in RCA: 188] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2011] [Revised: 04/29/2011] [Accepted: 05/13/2011] [Indexed: 01/08/2023]
Abstract
Desorption electrospray ionization mass spectrometry (DESI-MS) imaging of biological samples allows untargeted analysis and structural characterization of lipids ionized from the near-surface region of a sample under ambient conditions. DESI is a powerful and sensitive MS ionization method for 2D and 3D imaging of lipids from direct and unmodified complex biological samples. This review describes the strengths and limitations of DESI-MS for lipid characterization and imaging together with the technical workflow and a survey of applications. Included are discussions of lipid mapping and biomarker discovery as well as a perspective on the future of DESI imaging.
Collapse
|
10
|
Cooks RG, Manicke NE, Dill AL, Ifa DR, Eberlin LS, Costa AB, Wang H, Huang G, Ouyang Z. New ionization methods and miniature mass spectrometers for biomedicine: DESI imaging for cancer diagnostics and paper spray ionization for therapeutic drug monitoring. Faraday Discuss 2011; 149:247-67; discussion 333-56. [PMID: 21413184 PMCID: PMC10712017 DOI: 10.1039/c005327a] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023]
Abstract
The state-of-the-art in two new ambient ionization methods for mass spectrometry, desorption electrospray ionization (DESI) and paper spray (PS), is described and their utility is illustrated with new studies on tissue imaging and biofluid analysis. DESI is an ambient ionization method that can be performed on untreated histological sections of biological tissue in the open lab environment to image lipids, fatty acids, hormones and other compounds. Paper spray is performed in the open lab too; it involves electrospraying dry blood spots or biofluid deposits from a porous medium. PS is characterized by extreme simplicity and speed: a spot of whole blood or other biofluid is analyzed directly from paper, simply by applying a high voltage to the moist paper. Both methods are being developed for use in diagnostics as a means to inform therapy. DESI imaging is applied to create molecular maps of tissue sections without prior labeling or other sample preparation. Like other methods of mass spectrometry imaging (MSI), it combines the chemical speciation of multiple analytes with information on spatial distributions. DESI imaging provides valuable information which correlates with the disease state of tissue as determined by standard histochemical methods. Positive-ion data are presented which complement previously reported negative-ion data on paired human bladder cancerous and adjacent normal tissue sections from 20 patients. These data add to the evidence already in the literature demonstrating that differences in the distributions of particular lipids contain disease-diagnostic information. Multivariate statistical analysis using principal component analysis (PCA) is used to analyze the imaging MS data, and so confirm differences between the lipid profiles of diseased and healthy tissue types. As more such data is acquired, DESI imaging has the potential to be a diagnostic tool for future cancer detection in situ; this suggests a potential role in guiding therapy in parallel with standard histochemical and immunohistological methods. The PS methodology is aimed at high-throughput clinical measurement of quantitative levels of particular therapeutic agents in blood and other biofluids. The experiment allows individual drugs to be quantified at therapeutic levels and data is presented showing quantitative drug analysis from mixtures of therapeutic drugs in whole blood. Data on cholesterol sulfate, a new possible prostate biomarker seen at elevated levels in diseased prostate tissue, but not in healthy prostate tissue in serum are reported using paper spray ionization.
Collapse
Affiliation(s)
- R Graham Cooks
- Department of Chemistry and Center for Analytical Instrumentation Development, Purdue University, West Lafayette, IN 47907, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Nakae H, Hiroi H, Momoeda M, Koizumi M, Iwamori M, Taketani Y. Inhibition of cell invasion and protease activity by cholesterol sulfate. Fertil Steril 2010; 94:2455-7. [DOI: 10.1016/j.fertnstert.2010.02.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2009] [Revised: 02/02/2010] [Accepted: 02/02/2010] [Indexed: 11/28/2022]
|
12
|
Eberlin LS, Dill AL, Costa AB, Ifa DR, Cheng L, Masterson T, Koch M, Ratliff TL, Cooks RG. Cholesterol sulfate imaging in human prostate cancer tissue by desorption electrospray ionization mass spectrometry. Anal Chem 2010; 82:3430-4. [PMID: 20373810 DOI: 10.1021/ac9029482] [Citation(s) in RCA: 137] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Development of methods for rapid distinction between cancerous and non-neoplastic tissues is an important goal in disease diagnosis. To this end, desorption electrospray ionization mass spectrometry (DESI-MS) imaging was applied to analyze the lipid profiles of thin tissue sections of 68 samples of human prostate cancer and normal tissue. The disease state of the tissue sections was determined by independent histopathological examination. Cholesterol sulfate was identified as a differentiating compound, found almost exclusively in cancerous tissues including tissue containing precancerous lesions. The presence of cholesterol sulfate in prostate tissues might serve as a tool for prostate cancer diagnosis although confirmation through larger and more diverse cohorts and correlations with clinical outcome data is needed.
Collapse
Affiliation(s)
- Livia S Eberlin
- Department of Chemistry and Center for Analytical Instrumentation Development, Purdue University, West Lafayette, Indiana 47907, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Radford DJ, Wang K, McNelis JC, Taylor AE, Hechenberger G, Hofmann J, Chahal H, Arlt W, Lord JM. Dehydroepiandrosterone sulfate directly activates protein kinase C-beta to increase human neutrophil superoxide generation. Mol Endocrinol 2010; 24:813-21. [PMID: 20172962 PMCID: PMC5417533 DOI: 10.1210/me.2009-0390] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2009] [Accepted: 01/07/2010] [Indexed: 01/03/2023] Open
Abstract
Dehydroepiandrosterone sulfate (DHEAS) is the most abundant steroid in the human circulation and is secreted by the adrenals in an age-dependent fashion, with maximum levels during the third decade and very low levels in old age. DHEAS is considered an inactive metabolite, whereas cleavage of the sulfate group generates dehydroepiandrosterone (DHEA), a crucial sex steroid precursor. However, here we show that DHEAS, but not DHEA, increases superoxide generation in primed human neutrophils in a dose-dependent fashion, thereby impacting on a key bactericidal mechanism. This effect was not prevented by coincubation with androgen and estrogen receptor antagonists but was reversed by the protein kinase C inhibitor Bisindolylmaleimide 1. Moreover, we found that neutrophils are unique among leukocytes in expressing an organic anion-transporting polypeptide D, able to mediate active DHEAS influx transport whereas they did not express steroid sulfatase that activates DHEAS to DHEA. A specific receptor for DHEAS has not yet been identified, but we show that DHEAS directly activated recombinant protein kinase C-beta (PKC-beta) in a cell-free assay. Enhanced PKC-beta activation by DHEAS resulted in increased phosphorylation of p47(phox), a crucial component of the active reduced nicotinamide adenine dinucleotide phosphate complex responsible for neutrophil superoxide generation. Our results demonstrate that PKC-beta acts as an intracellular receptor for DHEAS in human neutrophils, a signaling mechanism entirely distinct from the role of DHEA as sex steroid precursor and with important implications for immunesenescence, which includes reduced neutrophil superoxide generation in response to pathogens.
Collapse
Affiliation(s)
- David J Radford
- Medical Research Council Centre for Immune Regulation, School of Immunity & Infection, University of Birmingham, Birmingham, United Kingdom
| | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Mikami M, Harasawa M, Sugiyama T, Nishijima Y, Goto Y, Hirasawa T, Muramatsu T, Iwamori M. Induction of the differentiation of cultured endometrial carcinoma cells by type I collagen: Relevance of sulfolipids. Oncol Lett 2010; 1:113-117. [PMID: 22966267 DOI: 10.3892/ol_00000021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2009] [Accepted: 06/09/2009] [Indexed: 11/06/2022] Open
Abstract
This study aimed to promote gland formation in cells derived from endometrial cancer, and assess the relevance of sulfolipids by performing culture with type I collagen. Tumors were developed in nude mice using cultured cell lines, gland formation was induced by culture with type I collagen and the composition of tumor cell sulfolipids was analyzed. Results showed that after culturing the cells on type I collagen gel, the gel was floated. Another layer of gel was placed on top so that the cells were sandwiched between two layers. Using this method, it was possible to induce gland formation in cells that formed only poorly differentiated tumors in nude mice. Mucous staining and electron microscopy demonstrated polarity of the glands. The cell lines that showed gland formation expressed sulfolipids, but not cholesterol sulfate. In conclusion, type I collagen and sulfolipids are involved in the process of gland formation in endometrioid adenocarcinoma.
Collapse
Affiliation(s)
- Mikio Mikami
- Department of Obstetrics and Gynecology, Tokai University School of Medicine, Kanagawa
| | | | | | | | | | | | | | | |
Collapse
|
15
|
Regulation of sulfotransferase and UDP-glucuronosyltransferase gene expression by the PPARs. PPAR Res 2009; 2009:728941. [PMID: 19680455 PMCID: PMC2724710 DOI: 10.1155/2009/728941] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2009] [Accepted: 04/14/2009] [Indexed: 01/12/2023] Open
Abstract
During phase II metabolism, a substrate is rendered more hydrophilic through the covalent attachment of an endogenous molecule. The cytosolic sulfotransferase (SULT) and UDP-glucuronosyltransferase (UGT) families of enzymes account for the majority of phase II metabolism in humans and animals. In general, phase II metabolism is considered to be a detoxication process, as sulfate and glucuronide conjugates are more amenable to excretion and elimination than are the parent substrates. However, certain products of phase II metabolism (e.g., unstable sulfate conjugates) are genotoxic. Members of the nuclear receptor superfamily are particularly important regulators of SULT and UGT gene transcription. In metabolically active tissues, increasing evidence supports a major role for lipid-sensing transcription factors, such as peroxisome proliferator-activated receptors (PPARs), in the regulation of rodent and human SULT and UGT gene expression. This review summarizes current information regarding the regulation of these two major classes of phase II metabolizing enzyme by PPARs.
Collapse
|
16
|
Shimada M, Matsuda T, Sato A, Akase T, Matsubara T, Nagata K, Yamazoe Y. Expression of a skin cholesterol sulfotransferase, St2b2, is a trigger of epidermal cell differentiation. Xenobiotica 2009; 38:1487-99. [PMID: 18979284 DOI: 10.1080/00498250802488593] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
1. St2b2, a mouse cytosolic sulfotransferase, predominantly catalyses epidermal cholesterol sulfation. St2b2 was found in the basement layer by immunohistochemical analysis of normal mouse skin. The highest expression level was detected in epidermis from 3-day-old mice and then decreased before maturation. There was a good correlation between expression levels of skin St2b2 and a differentiation marker, involucrin. 2. To understand the role of St2b2 in epidermal cell differentiation, recombinant St2b2 was expressed in primary epidermal cells. The expression of St2b2 enhanced the involucrin expression with an increase of cholesterol sulfate. Furthermore, by down-regulation of the St2b2 gene expression, involucrin was decreased in dorsal skin of 1-3-day-old mice by 67% of the control. 3. These results strongly suggest a possibility that St2b2 expression plays a trigger of epidermal cell differentiation by controlling cholesterol sulfate level in the cells.
Collapse
Affiliation(s)
- M Shimada
- Division of Drug Metabolism and Molecular Toxicology, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba-ku, Sendai, Japan.
| | | | | | | | | | | | | |
Collapse
|
17
|
Abstract
The combined effects of cholesterol, a major cell membrane component, and the lipid second messenger diacylglycerol on the activity of protein kinase C (PK-C) and the structure of phosphatidylcholine/phosphatidylserine bilayers were investigated using specific PK-C assays and (2)H NMR. Whereas the classical activation of PK-C was observed as an effect of diacylglycerol, in the absence of this second messenger, cholesterol did not affect PK-C activity. A novel effect of amplified PK-C activation was observed in the presence of both cholesterol and diacylglycerol concentrations within the physiological range of each of these components. (2)H NMR results suggest that this phenomenon is due to cholesterol- and diacylglycerol-induced increased propensity of the lipids to adopt nonbilayer phases, effectively destabilizing the bilayer structure. The magnitude of the effect was a function of cholesterol concentration, implying that laterally separated cell membrane domains with distinct cholesterol concentrations have the capacity to differ in their sensitivity to extracellular stimuli.
Collapse
|
18
|
Elias PM, Williams ML, Holleran WM, Jiang YJ, Schmuth M. Pathogenesis of permeability barrier abnormalities in the ichthyoses: inherited disorders of lipid metabolism. J Lipid Res 2008; 49:697-714. [PMID: 18245815 DOI: 10.1194/jlr.r800002-jlr200] [Citation(s) in RCA: 142] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Many of the ichthyoses are associated with inherited disorders of lipid metabolism. These disorders have provided unique models to dissect physiologic processes in normal epidermis and the pathophysiology of more common scaling conditions. In most of these disorders, a permeability barrier abnormality "drives" pathophysiology through stimulation of epidermal hyperplasia. Among primary abnormalities of nonpolar lipid metabolism, triglyceride accumulation in neutral lipid storage disease as a result of a lipase mutation provokes a barrier abnormality via lamellar/nonlamellar phase separation within the extracellular matrix of the stratum corneum (SC). Similar mechanisms account for the barrier abnormalities (and subsequent ichthyosis) in inherited disorders of polar lipid metabolism. For example, in recessive X-linked ichthyosis (RXLI), cholesterol sulfate (CSO(4)) accumulation also produces a permeability barrier defect through lamellar/nonlamellar phase separation. However, in RXLI, the desquamation abnormality is in part attributable to the plurifunctional roles of CSO(4) as a regulator of both epidermal differentiation and corneodesmosome degradation. Phase separation also occurs in type II Gaucher disease (GD; from accumulation of glucosylceramides as a result of to beta-glucocerebrosidase deficiency). Finally, failure to assemble both lipids and desquamatory enzymes into nascent epidermal lamellar bodies (LBs) accounts for both the permeability barrier and desquamation abnormalities in Harlequin ichthyosis (HI). The barrier abnormality provokes the clinical phenotype in these disorders not only by stimulating epidermal proliferation, but also by inducing inflammation.
Collapse
Affiliation(s)
- Peter M Elias
- Dermatology Services, Veterans Affairs Medical Center, University of California, San Francisco, CA, USA.
| | | | | | | | | |
Collapse
|
19
|
Aziz MH, Manoharan HT, Sand JM, Verma AK. Protein kinase Cepsilon interacts with Stat3 and regulates its activation that is essential for the development of skin cancer. Mol Carcinog 2007; 46:646-53. [PMID: 17583567 DOI: 10.1002/mc.20356] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Protein kinase C (PKC) represents a large family of phosphatidylserine (PS)-dependent serine/threonine protein kinases. At least six PKC isoforms (alpha, delta, epsilon, eta, micro, and zeta) are expressed in epidermis. PKC is a major intracellular receptor for 12-O-tetradecanoylphorbol-13-acetate (TPA) and is also activated by a variety of stress factors including ultraviolet radiation (UVR). PKC isozymes (alpha, delta, epsilon, and eta), exhibit specificities to the development of skin cancer. PKCepsilon, a calcium-insensitive PKC isoform, is linked to the development of squamous cell carcinoma (SCC) elicited either by the 7,12-Dimethylbenzanthracene (DMBA)-TPA protocol or by repeated exposures to UVR. PKCepsilon overexpressing transgenic mice, when treated either with TPA or exposed to UVR, elicit similar responses such as inhibition of apoptosis, promotion of cell survival, and development of SCC. PKCepsilon overexpression increases Stat3 activation after either TPA treatment or UVR exposure. Both PKCepsilon and signal transducers and activators of transcription-3 (Stat3) are implicated in the development of SCC. However, the link between PKCepsilon and Stat3 remains elusive. We found that PKCepsilon interacts with Stat3. PKCepsilon interaction with Stat3 was dependent upon UVR treatment. In reciprocal immunoprecipitation/blotting experiments, Stat3 coimmunoprecipitated with PKCepsilon. Colocalization of PKCepsilon with Stat3 was confirmed by double immunofluorescence staining. PKCepsilon interaction with Stat3 was PKCepsilon isoform specific and was not observed with other protein kinases. As observed in vitro with immunocomplex kinase assay with immunopurified PKCepsilon and Stat3, PKCepsilon phosphorylated Stat3 at the serine 727 residue. PKCepsilon depletion prevented Stat3Ser727 phosphorylation, Stat3 DNA binding, and transcriptional activity. The results presented indicate that PKCepsilon mediates Stat3 activation.
Collapse
Affiliation(s)
- Moammir H Aziz
- Department of Human Oncology, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin 53792, USA
| | | | | | | |
Collapse
|
20
|
Breitkreutz D, Braiman-Wiksman L, Daum N, Denning MF, Tennenbaum T. Protein kinase C family: on the crossroads of cell signaling in skin and tumor epithelium. J Cancer Res Clin Oncol 2007; 133:793-808. [PMID: 17661083 DOI: 10.1007/s00432-007-0280-3] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2006] [Accepted: 07/03/2007] [Indexed: 12/28/2022]
Abstract
The protein kinase C (PKC) family represents a large group of phospholipid dependent enzymes catalyzing the covalent transfer of phosphate from ATP to serine and threonine residues of proteins. Phosphorylation of the substrate proteins induces a conformational change resulting in modification of their functional properties. The PKC family consists of at least ten members, divided into three subgroups: classical PKCs (alpha, betaI, betaII, gamma), novel PKCs (delta, epsilon, eta, theta), and atypical PKCs (zeta, iota/lambda). The specific cofactor requirements, tissue distribution, and cellular compartmentalization suggest differential functions and fine tuning of specific signaling cascades for each isoform. Thus, specific stimuli can lead to differential responses via isoform specific PKC signaling regulated by their expression, localization, and phosphorylation status in particular biological settings. PKC isoforms are activated by a variety of extracellular signals and, in turn, modify the activities of cellular proteins including receptors, enzymes, cytoskeletal proteins, and transcription factors. Accordingly, the PKC family plays a central role in cellular signal processing. Accumulating data suggest that various PKC isoforms participate in the regulation of cell proliferation, differentiation, survival and death. These findings have enabled identification of abnormalities in PKC isoform function, as they occur in several cancers. Specifically, the initiation of squamous cell carcinoma formation and progression to the malignant phenotype was found to be associated with distinct changes in PKC expression, activation, distribution, and phosphorylation. These studies were recently further extended to transgenic and knockout animals, which allowed a more direct analysis of individual PKC functions. Accordingly, this review is focused on the involvement of PKC in physiology and pathology of the skin.
Collapse
Affiliation(s)
- D Breitkreutz
- Division of Differentiation and Carcinogenesis (A080/A110), German Cancer Research Center (DKFZ), POB 101949, Im Neuenheimer Feld 280, 69009, Heidelberg, Germany.
| | | | | | | | | |
Collapse
|
21
|
Lentz MR, Stevens SM, Raynes J, Elkhoury N. A phosphorylation map of the bovine papillomavirus E1 helicase. Virol J 2006; 3:13. [PMID: 16524476 PMCID: PMC1450263 DOI: 10.1186/1743-422x-3-13] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2005] [Accepted: 03/08/2006] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Papillomaviruses undergo a complex life cycle requiring regulated DNA replication. The papillomavirus E1 helicase is essential for viral DNA replication and plays a key role in controlling viral genome copy number. The E1 helicase is regulated at least in part by protein phosphorylation, however no systematic approach to phosphate site mapping has been attempted. We have utilized mass spectrometry of purified bovine papillomavirus E1 protein to identify and characterize new sites of phosphorylation. RESULTS Mass spectrometry and in silico sequence analysis were used to identify phosphate sites on the BPV E1 protein and kinases that may recognize these sites. Five new and two previously known phosphorylation sites were identified. A phosphate site map was created and used to develop a general model for the role of phosphorylation in E1 function. CONCLUSION Mass spectrometric analysis identified seven phosphorylated amino acids on the BPV E1 protein. Taken with three previously identified sites, there are at least ten phosphoamino acids on BPV E1. A number of kinases were identified by sequence analysis that could potentially phosphorylate E1 at the identified positions. Several of these kinases have known roles in regulating cell cycle progression. A BPV E1 phosphate map and a discussion of the possible role of phosphorylation in E1 function are presented.
Collapse
Affiliation(s)
- Michael R Lentz
- Department of Biology, University of North Florida, 4567 St. Johns Bluff Rd., S., Jacksonville, FL 32224, USA
| | - Stanley M Stevens
- Proteomics Core, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, FL 32610, USA
| | - Joshua Raynes
- Department of Biology, University of North Florida, 4567 St. Johns Bluff Rd., S., Jacksonville, FL 32224, USA
| | - Nancy Elkhoury
- Department of Biology, University of North Florida, 4567 St. Johns Bluff Rd., S., Jacksonville, FL 32224, USA
| |
Collapse
|
22
|
Efimova T, Broome AM, Eckert RL. Protein kinase Cdelta regulates keratinocyte death and survival by regulating activity and subcellular localization of a p38delta-extracellular signal-regulated kinase 1/2 complex. Mol Cell Biol 2004; 24:8167-83. [PMID: 15340077 PMCID: PMC515052 DOI: 10.1128/mcb.24.18.8167-8183.2004] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Protein kinase Cdelta (PKCdelta) is an important regulator of apoptosis in epidermal keratinocytes. However, little information is available regarding the downstream kinases that mediate PKCdelta-dependent keratinocyte death. This study implicates p38delta mitogen-activated protein kinase (MAPK) as a downstream carrier of the PKCdelta-dependent death signal. We show that coexpression of PKCdelta with p38delta produces profound apoptosis-like morphological changes. These morphological changes are associated with increased sub-G(1) cell population, cytochrome c release, loss of mitochondrial membrane potential, caspase activation, and PARP cleavage. This death response is specific for the combination of PKCdelta and p38delta and is not produced by replacing PKCdelta with PKCalpha or p38delta with p38alpha. A constitutively active form of MEK6, an upstream activator of p38delta, can also produce cell death when coupled with p38delta. In addition, concurrent p38delta activation and extracellular signal-regulated kinase 1/2 (ERK1/2) inactivation are required for apoptosis. Regarding this inverse regulation, we describe a p38delta-ERK1/2 complex that may coordinate these changes in activity. We further show that this p38delta-ERK1/2 complex relocates into the nucleus in response to PKCdelta expression. This regulation appears to be physiological, since H(2)O(2), a known inducer of keratinocyte apoptosis, promotes identical PKCdelta and p38delta-ERK1/2 activity changes, leading to similar morphological changes.
Collapse
Affiliation(s)
- Tatiana Efimova
- Department of Physiology, Case Western Reserve University School of Medicine, 2109 Adelbert Rd., Cleveland, OH 44106-4970, USA
| | | | | |
Collapse
|
23
|
Okano M, Yokoyama T, Miyanaga T, Ohtsuki K. Activation of C-Kinase .ETA. through Its Cholesterol-3-sulfate-Dependent Phosphorylation by Casein Kinase I in Vitro. Biol Pharm Bull 2004; 27:109-12. [PMID: 14709910 DOI: 10.1248/bpb.27.109] [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: 11/22/2022]
Abstract
The physiological correlation between casein kinase I (CK-I) and an isoform eta of protein kinase C (C-kinase eta) was investigated in vitro, since it has been reported that (i) cholesterol-3-sulfate (CH-3S) effectively activates C-kinase eta rather than the other isoforms (C-kinase epsilon and C-kinase delta) in vitro; and (ii) CK-I efficiently phosphorylates CH-3S-binding proteins, such as high mobility group protein 1 (HMG1), in the presence of CH-3S in vitro. We found that (i) CK-I phosphorylated Thr in preference to Ser on recombinant human C-kinase isoform eta (rhC-kinase eta) in the presence of CH-3S; (ii) this phosphorylation was selectively inhibited by CK-I-7 (a CK-I inhibitor); and (iii) the activity (phosphorylation of protamine sulfate) of rhC-kinase eta was approx. 3.2-fold stimulated by its full phosphorylation by CK-I in the presence of 3 microM CH-3S. These results suggest that CK-I is a protein kinase responsible for the activation of rhC-kinase eta in the presence of CH-3S in vitro.
Collapse
Affiliation(s)
- Maiko Okano
- Laboratory of Genetical Biochemistry and Signal Biology, Graduate School of Medical Sciences, Kitasato University, 1-15-1 Kitasato, Sagamihara 228-8555, Japan
| | | | | | | |
Collapse
|
24
|
Lee KA, Fuda H, Lee YC, Negishi M, Strott CA, Pedersen LC. Crystal structure of human cholesterol sulfotransferase (SULT2B1b) in the presence of pregnenolone and 3'-phosphoadenosine 5'-phosphate. Rationale for specificity differences between prototypical SULT2A1 and the SULT2BG1 isoforms. J Biol Chem 2003; 278:44593-9. [PMID: 12923182 DOI: 10.1074/jbc.m308312200] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The gene for human hydroxysteroid sulfotransferase (SULT2B1) encodes two peptides, SULT2B1a and SULT2B1b, that differ only at their amino termini. SULT2B1b has a predilection for cholesterol but is also capable of sulfonating pregnenolone, whereas SULT2B1a preferentially sulfonates pregnenolone and only minimally sulfonates cholesterol. We have determined the crystal structure of SULT2B1a and SULT2B1b bound to the substrate donor product 3'-phosphoadenosine 5'-phosphate at 2.9 and 2.4 A, respectively, as well as SULT2B1b in the presence of the acceptor substrate pregnenolone at 2.3 A. These structures reveal a different catalytic binding orientation for the substrate from a previously determined structure of hydroxysteroid sulfotransferase (SULT2A1) binding dehydroepiandrosterone. In addition, the amino-terminal helix comprising residues Asp19 to Lys26, which determines the specificity difference between the SULT2B1 isoforms, becomes ordered upon pregnenolone binding, covering the substrate binding pocket.
Collapse
Affiliation(s)
- Karen A Lee
- Laboratory of Structural Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina 27709, USA
| | | | | | | | | | | |
Collapse
|
25
|
Sintov AC, Krymberk I, Gavrilov V, Gorodischer R. Transdermal delivery of paracetamol for paediatric use: effects of vehicle formulations on the percutaneous penetration. J Pharm Pharmacol 2003; 55:911-9. [PMID: 12906748 DOI: 10.1211/0022357021486] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Paracetamol is a safe and effective analgesic and antipyretic agent, and is one of the most widely used medications for infants and children. The formulations currently available have been designed for oral and rectal administration. However, they are not practical in young patients with vomiting and diarrhoea, or in those who refuse to take the full dose. An alternative route of administration would be a significant contribution to the paediatric pharmacopoeia. The aim of this study was to develop a new transdermal system for optional therapeutic administration of paracetamol in infants and children. In-vivo studies were carried out in animals using a transdermal system of high-loaded, soluble paracetamol in a hydrogel patch, which was also tested in-vitro for 8 h. Although the beneficial contribution of glyceryl oleate to the transdermal penetration of paracetamol seemed to be significant in-vitro, it was shown to be insufficient in-vivo. To improve the penetration of the drug, 4% PEG-40 stearate and 10% ethanol were incorporated as absorption enhancers into the dermal patches. A few hours after application of the improved patches to rats, plasma drug concentrations were elevated to levels comparable with those obtained after oral and subcutaneous administration of a high dose of paracetamol. Since plasma drug concentrations did not reach a constant steady state (as a peak or plateau) during the short-term animal experiments, longer pharmacokinetic studies in conscious animals are necessary.
Collapse
Affiliation(s)
- Amnon C Sintov
- The Institutes for Applied Research, Ben Gurion University of the Negev, Beer Sheva 84105, Israel.
| | | | | | | |
Collapse
|
26
|
Abstract
Cholesterol sulfate is quantitatively the most important known sterol sulfate in human plasma, where it is present in a concentration that overlaps that of the other abundant circulating steroid sulfate, dehydroepiandrosterone (DHEA) sulfate. Although these sulfolipids have similar production and metabolic clearance rates, they arise from distinct sources and are metabolized by different pathways. While the function of DHEA sulfate remains an enigma, cholesterol sulfate has emerged as an important regulatory molecule. Cholesterol sulfate is a component of cell membranes where it has a stabilizing role, e.g., protecting erythrocytes from osmotic lysis and regulating sperm capacitation. It is present in platelet membranes where it supports platelet adhesion. Cholesterol sulfate can regulate the activity of serine proteases, e.g., those involved in blood clotting, fibrinolysis, and epidermal cell adhesion. As a result of its ability to regulate the activity of selective protein kinase C isoforms and modulate the specificity of phosphatidylinositol 3-kinase, cholesterol sulfate is involved in signal transduction. Cholesterol sulfate functions in keratinocyte differentiation, inducing genes that encode for key components involved in development of the barrier. The accumulating evidence demonstrating a regulatory function for cholesterol sulfate appears solid; the challenge now is to work out the molecular mechanisms whereby this interesting molecule carries out its various roles.
Collapse
Affiliation(s)
- Charles A Strott
- Section on Steroid Regulation, Endocrinology and Reproduction Research Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-4510, USA.
| | | |
Collapse
|
27
|
Fuda H, Lee YC, Shimizu C, Javitt NB, Strott CA. Mutational analysis of human hydroxysteroid sulfotransferase SULT2B1 isoforms reveals that exon 1B of the SULT2B1 gene produces cholesterol sulfotransferase, whereas exon 1A yields pregnenolone sulfotransferase. J Biol Chem 2002; 277:36161-6. [PMID: 12145317 DOI: 10.1074/jbc.m207165200] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
As a result of an alternative exon 1, the gene for human hydroxysteroid sulfotransferase (SULTB1) encodes for two peptides differing only at their amino termini. The SULT2B1b isoform preferentially sulfonates cholesterol. Conversely, the SULT2B1a isoform avidly sulfonates pregnenolone but not cholesterol. The outstanding structural feature that distinguishes the SULT2B1 isoforms from the prototypical SULT2A1 isozyme is the presence of extended amino- and carboxyl-terminal ends in the former. Investigating the functional significance of this unique characteristic reveals that removal of 53 amino acids from the relatively long carboxyl-terminal end that is common to both SULT2B1 isoforms has no effect on the catalytic activity of either isoform. On the other hand, removal of 23 amino acids from the amino-terminal end that is unique to SULT2B1b results in loss of cholesterol sulfotransferase activity, whereas removal of 8 amino acids from the amino-terminal end that is unique to SULT2B1a has no effect on pregnenolone sulfotransferase activity. Deletion analysis along with site-directed mutagenesis of SULT2B1b reveal that the amino acid segment 19-23 residues from the amino terminus and particularly isoleucines at positions 21 and 23 are crucial for cholesterol catalysis. In the gene for SULT2B1, exon 1B encodes for only the unique amino-terminal region of SULT2B1b; however, exon 1A encodes for the unique amino-terminal end of SULT2B1a plus an additional 48 amino acids. Thus, if the gene for SULT2B1 employs exon 1B, cholesterol sulfotransferase is synthesized, whereas if exon 1A is used, pregnenolone sulfotransferase is produced.
Collapse
Affiliation(s)
- Hirotoshi Fuda
- Section on Steroid Regulation, Endocrinology and Reproduction Research Branch, NICHD, National Institutes of Health, Bethesda, Maryland 20892-4510, USA
| | | | | | | | | |
Collapse
|