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Rikhi R, Schaich CL, Hafzalla GW, Patel NA, Tannenbaum JE, German CA, Polonsky T, Tsai MY, Ahmad MI, Islam T, Chevli PA, Shapiro MD. Small Dense Low-Density Lipoprotein Cholesterol and Coronary Artery Calcification in the Multi-Ethnic Study of Atherosclerosis. Eur J Prev Cardiol 2024:zwae049. [PMID: 38323698 DOI: 10.1093/eurjpc/zwae049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 01/17/2024] [Accepted: 02/05/2024] [Indexed: 02/08/2024]
Abstract
AIM Elevated small dense-LDL-cholesterol (sd-LDL-C) increases atherosclerotic cardiovascular disease (CVD) risk. Although coronary artery calcium (CAC) is widely used for predicting CVD events, few studies have examined the relationship between sd-LDL-C and CAC. METHODS This study included 4672 individuals with directly-measured baseline sd-LDL-C and CAC from the Multi-Ethnic Study of Atherosclerosis (mean [SD] age: 61.9 [10.4] years; 52.5% women; 47.3% with baseline CAC [mean score >0]). We used multivariable general linear models and restricted cubic splines with goodness of fit testing to evaluate the association of sd-LDL-C with the presence of CAC. Odds ratios (OR [95% CI]) were adjusted for demographics and cardiovascular risk factors, including estimated total LDL-C. RESULTS Higher quartiles of sd-LDL-C were associated with presence of CAC, even after accounting for total LDL-C. Compared to the lowest quartile of sd-LDL-C, participants in Quartiles 2, 3 and 4 had higher odds for the presence of baseline CAC (Quartile 2 OR: 1.24 [1.00, 1.53]; Quartile 3 OR: 1.51 [1.19, 1.93]; and Quartile 4 OR 1.59 [1.17, 2.16]). Splines suggested a quadratic curvilinear relationship of continuous sd-LDL-C with CAC after adjustment for demographics and CVD risk factors (quadratic vs. first-order sd-LDL-C terms likelihood ratio test: p=0.015), but not after accounting for total LDL-C (quadratic vs. first-order terms: p=0.156). CONCLUSIONS In a large, multi-ethnic sample without known CVD, higher sd-LDL-C was associated with the presence of CAC, above and beyond total LDL-C. Whether selective direct measurement of sd-LDL-C is indicated to refine cardiovascular risk assessment in primary prevention warrants further investigation.
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Affiliation(s)
- Rishi Rikhi
- Center for Prevention of Cardiovascular Disease, Section on Cardiovascular Medicine, Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
| | - Christopher L Schaich
- Department of Surgery, Hypertension and Vascular Research Centre, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
| | - George W Hafzalla
- Department of Internal Medicine, Loma Linda University Health, Loma Linda, California, USA
| | - Nisha A Patel
- Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
| | - Jordan E Tannenbaum
- Center for Prevention of Cardiovascular Disease, Section on Cardiovascular Medicine, Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
| | - Charles A German
- Department of Internal Medicine, Section of Cardiology, University of Chicago, Chicago, Illinois, USA
| | - Tamar Polonsky
- Department of Internal Medicine, Section of Cardiology, University of Chicago, Chicago, Illinois, USA
| | - Michael Y Tsai
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, Minnesota, USA
| | - Muhammad I Ahmad
- Department of Internal Medicine, Section on Hospital Medicine, Medical College of Wisconsin, Wauwatosa, WI, USA
| | - Tareq Islam
- Department of Medicine, Beth Israel Deaconess Medical Centre, Boston, Massachusetts, USA
| | - Parag A Chevli
- Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
| | - Michael D Shapiro
- Center for Prevention of Cardiovascular Disease, Section on Cardiovascular Medicine, Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
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Wortham M, Liu F, Harrington AR, Fleischman JY, Wallace M, Mulas F, Mallick M, Vinckier NK, Cross BR, Chiou J, Patel NA, Sui Y, McGrail C, Jun Y, Wang G, Jhala US, Schüle R, Shirihai OS, Huising MO, Gaulton KJ, Metallo CM, Sander M. Nutrient regulation of the islet epigenome controls adaptive insulin secretion. J Clin Invest 2023; 133:e165208. [PMID: 36821378 PMCID: PMC10104905 DOI: 10.1172/jci165208] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 02/14/2023] [Indexed: 02/24/2023] Open
Abstract
Adaptation of the islet β cell insulin-secretory response to changing insulin demand is critical for blood glucose homeostasis, yet the mechanisms underlying this adaptation are unknown. Here, we have shown that nutrient-stimulated histone acetylation plays a key role in adapting insulin secretion through regulation of genes involved in β cell nutrient sensing and metabolism. Nutrient regulation of the epigenome occurred at sites occupied by the chromatin-modifying enzyme lysine-specific demethylase 1 (Lsd1) in islets. β Cell-specific deletion of Lsd1 led to insulin hypersecretion, aberrant expression of nutrient-response genes, and histone hyperacetylation. Islets from mice adapted to chronically increased insulin demand exhibited shared epigenetic and transcriptional changes. Moreover, we found that genetic variants associated with type 2 diabetes were enriched at LSD1-bound sites in human islets, suggesting that interpretation of nutrient signals is genetically determined and clinically relevant. Overall, these studies revealed that adaptive insulin secretion involves Lsd1-mediated coupling of nutrient state to regulation of the islet epigenome.
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Affiliation(s)
- Matthew Wortham
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center and
| | - Fenfen Liu
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center and
| | - Austin R. Harrington
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center and
| | - Johanna Y. Fleischman
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center and
| | - Martina Wallace
- Department of Bioengineering, UCSD, La Jolla, California, USA
| | - Francesca Mulas
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center and
| | - Medhavi Mallick
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center and
| | - Nicholas K. Vinckier
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center and
| | - Benjamin R. Cross
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center and
| | - Joshua Chiou
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center and
| | - Nisha A. Patel
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center and
| | - Yinghui Sui
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center and
| | - Carolyn McGrail
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center and
| | - Yesl Jun
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center and
| | - Gaowei Wang
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center and
| | - Ulupi S. Jhala
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center and
| | - Roland Schüle
- Department of Urology, University of Freiburg Medical Center, Freiburg, Germany
| | - Orian S. Shirihai
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
| | - Mark O. Huising
- Department of Neurobiology, Physiology and Behavior, College of Biological Sciences, and Physiology and Membrane Biology, School of Medicine, UCD, Davis, California, USA
| | - Kyle J. Gaulton
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center and
| | | | - Maike Sander
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center and
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Vinckier NK, Patel NA, Geusz RJ, Wang A, Wang J, Matta I, Harrington AR, Wortham M, Wetton N, Wang J, Jhala US, Rosenfeld MG, Benner CW, Shih HP, Sander M. LSD1-mediated enhancer silencing attenuates retinoic acid signalling during pancreatic endocrine cell development. Nat Commun 2020; 11:2082. [PMID: 32350257 PMCID: PMC7190832 DOI: 10.1038/s41467-020-16017-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 04/07/2020] [Indexed: 01/22/2023] Open
Abstract
Developmental progression depends on temporally defined changes in gene expression mediated by transient exposure of lineage intermediates to signals in the progenitor niche. To determine whether cell-intrinsic epigenetic mechanisms contribute to signal-induced transcriptional responses, here we manipulate the signalling environment and activity of the histone demethylase LSD1 during differentiation of hESC-gut tube intermediates into pancreatic endocrine cells. We identify a transient requirement for LSD1 in endocrine cell differentiation spanning a short time-window early in pancreas development, a phenotype we reproduced in mice. Examination of enhancer and transcriptome landscapes revealed that LSD1 silences transiently active retinoic acid (RA)-induced enhancers and their target genes. Furthermore, prolonged RA exposure phenocopies LSD1 inhibition, suggesting that LSD1 regulates endocrine cell differentiation by limiting the duration of RA signalling. Our findings identify LSD1-mediated enhancer silencing as a cell-intrinsic epigenetic feedback mechanism by which the duration of the transcriptional response to a developmental signal is limited.
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Affiliation(s)
- Nicholas K Vinckier
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, Sanford Consortium for Regenerative Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Nisha A Patel
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, Sanford Consortium for Regenerative Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Ryan J Geusz
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, Sanford Consortium for Regenerative Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Allen Wang
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, Sanford Consortium for Regenerative Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Jinzhao Wang
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, Sanford Consortium for Regenerative Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Ileana Matta
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, Sanford Consortium for Regenerative Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Austin R Harrington
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, Sanford Consortium for Regenerative Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Matthew Wortham
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, Sanford Consortium for Regenerative Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Nichole Wetton
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, Sanford Consortium for Regenerative Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Jianxun Wang
- Howard Hughes Medical Institute and Department of Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Ulupi S Jhala
- Department of Pediatrics and Pediatric Diabetes Research Center, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Michael G Rosenfeld
- Howard Hughes Medical Institute and Department of Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Christopher W Benner
- Department of Cellular & Molecular Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Hung-Ping Shih
- Department of Translational Research & Cellular Therapeutics, Diabetes & Metabolism Research Institute, City of Hope, Duarte, CA, 91010, USA
| | - Maike Sander
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, Sanford Consortium for Regenerative Medicine, University of California, San Diego, La Jolla, CA, 92093, USA.
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Guélin M, Patel NA, Bremer M, Cernicharo J, Castro-Carrizo A, Pety J, Fonfría JP, Agúndez M, Santander-García M, Quintana-Lacaci G, Velilla Prieto L, Blundell R, Thaddeus P. IRC +10 216 in 3-D: morphology of a TP-AGB star envelope. Astron Astrophys 2018; 610:A4. [PMID: 29456257 PMCID: PMC5815495 DOI: 10.1051/0004-6361/201731619] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
During their late pulsating phase, AGB stars expel most of their mass in the form of massive dusty envelopes, an event that largely controls the composition of interstellar matter. The envelopes, however, are distant and opaque to visible and NIR radiation: their structure remains poorly known and the mass-loss process poorly understood. Millimeter-wave interferometry, which combines the advantages of longer wavelength, high angular resolution and very high spectral resolution is the optimal investigative tool for this purpose. Mm waves pass through dust with almost no attenuation. Their spectrum is rich in molecular lines and hosts the fundamental lines of the ubiquitous CO molecule, allowing a tomographic reconstruction of the envelope structure. The circumstellar envelope IRC +10 216 and its central star, the C-rich TP-AGB star closest to the Sun, are the best objects for such an investigation. Two years ago, we reported the first detailed study of the CO(2-1) line emission in that envelope, made with the IRAM 30-m telescope. It revealed a series of dense gas shells, expanding at a uniform radial velocity. The limited resolution of the telescope (HPBW 11″) did not allow us to resolve the shell structure. We now report much higher angular resolution observations of CO(2-1), CO(1-0), CN(2-1) and C4H(24-23) made with the SMA, PdB and ALMA interferometers (with synthesized half-power beamwidths of 3″, 1″ and 0.3″, respectively). Although the envelope appears much more intricate at high resolution than with an 11″ beam, its prevailing structure remains a pattern of thin, nearly concentric shells. The average separation between the brightest CO shells is 16″ in the outer envelope, where it appears remarkably constant. Closer to the star (< 40″), the shell pattern is denser and less regular, showing intermediary arcs. Outside the small (r < 0.3″) dust formation zone, the gas appears to expand radially at a constant velocity, 14.5 km s-1, with small turbulent motions. Based on that property, we have reconstructed the 3-D structure of the outer envelope and have derived the gas temperature and density radial profiles in the inner (r < 25″) envelope. The shell-intershell density contrast is found to be typically 3. The over-dense shells have spherical or slightly oblate shapes and typically extend over a few steradians, implying isotropic mass loss. The regular spacing of shells in the outer envelope supports the model of a binary star system with a period of 700 years and a near face-on elliptical orbit. The companion fly-by triggers enhanced episodes of mass loss near periastron. The densification of the shell pattern observed in the central part of the envelope suggests a more complex scenario for the last few thousand years.
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Affiliation(s)
- M Guélin
- Institut de Radioastronomie Millimétrique, 300 rue de la Piscine, 38406 Saint Martin d'Hères, France
- LERMA, Observatoire de Paris, PSL Research University, CNRS, UMR 8112, F-75014, Paris, France
| | - N A Patel
- Center for Astrophysics, 60 Garden street, Cambridge, MA USA
| | - M Bremer
- Institut de Radioastronomie Millimétrique, 300 rue de la Piscine, 38406 Saint Martin d'Hères, France
| | - J Cernicharo
- ICMM. CSIC. Group of Molecular Astrophysics. C/ Sor Juana Inés de la Cruz 3. Cantoblanco, E-28049 Madrid, Spain
| | - A Castro-Carrizo
- Institut de Radioastronomie Millimétrique, 300 rue de la Piscine, 38406 Saint Martin d'Hères, France
| | - J Pety
- Institut de Radioastronomie Millimétrique, 300 rue de la Piscine, 38406 Saint Martin d'Hères, France
| | - J P Fonfría
- ICMM. CSIC. Group of Molecular Astrophysics. C/ Sor Juana Inés de la Cruz 3. Cantoblanco, E-28049 Madrid, Spain
| | - M Agúndez
- ICMM. CSIC. Group of Molecular Astrophysics. C/ Sor Juana Inés de la Cruz 3. Cantoblanco, E-28049 Madrid, Spain
| | - M Santander-García
- ICMM. CSIC. Group of Molecular Astrophysics. C/ Sor Juana Inés de la Cruz 3. Cantoblanco, E-28049 Madrid, Spain
| | - G Quintana-Lacaci
- ICMM. CSIC. Group of Molecular Astrophysics. C/ Sor Juana Inés de la Cruz 3. Cantoblanco, E-28049 Madrid, Spain
| | - L Velilla Prieto
- ICMM. CSIC. Group of Molecular Astrophysics. C/ Sor Juana Inés de la Cruz 3. Cantoblanco, E-28049 Madrid, Spain
| | - R Blundell
- Center for Astrophysics, 60 Garden street, Cambridge, MA USA
| | - P Thaddeus
- Center for Astrophysics, 60 Garden street, Cambridge, MA USA
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5
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Kyrieleis OJP, McIntosh PB, Webb SR, Calder LJ, Lloyd J, Patel NA, Martin SR, Robinson CV, Rosenthal PB, Smerdon SJ. Three-Dimensional Architecture of the Human BRCA1-A Histone Deubiquitinase Core Complex. Cell Rep 2017; 17:3099-3106. [PMID: 28009280 PMCID: PMC5199339 DOI: 10.1016/j.celrep.2016.11.063] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 11/10/2016] [Accepted: 11/21/2016] [Indexed: 12/31/2022] Open
Abstract
BRCA1 is a tumor suppressor found to be mutated in hereditary breast and ovarian cancer and plays key roles in the maintenance of genomic stability by homologous recombination repair. It is recruited to damaged chromatin as a component of the BRCA1-A deubiquitinase, which cleaves K63-linked ubiquitin chains attached to histone H2A and H2AX. BRCA1-A contributes to checkpoint regulation, repair pathway choice, and HR repair efficiency through molecular mechanisms that remain largely obscure. The structure of an active core complex comprising two Abraxas/BRCC36/BRCC45/MERIT40 tetramers determined by negative-stain electron microscopy (EM) reveals a distorted V-shape architecture in which a dimer of Abraxas/BRCC36 heterodimers sits at the base, with BRCC45/Merit40 pairs occupying each arm. The location and ubiquitin-binding activity of BRCC45 suggest that it may provide accessory interactions with nucleosome-linked ubiquitin chains that contribute to their efficient processing. Our data also suggest how ataxia telangiectasia mutated (ATM)-dependent BRCA1 dimerization may stabilize self-association of the entire BRCA1-A complex.
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Affiliation(s)
- Otto J P Kyrieleis
- Structural Biology of DNA-Damage Signalling Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Pauline B McIntosh
- Structural Biology of Cells and Viruses Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Sarah R Webb
- Structural Biology of DNA-Damage Signalling Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Lesley J Calder
- Structural Biology of Cells and Viruses Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Janette Lloyd
- Structural Biology of DNA-Damage Signalling Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Nisha A Patel
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, OX1 3QZ Oxford, UK
| | - Stephen R Martin
- Structural Biology Technology Platform, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Carol V Robinson
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, OX1 3QZ Oxford, UK
| | - Peter B Rosenthal
- Structural Biology of Cells and Viruses Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK.
| | - Stephen J Smerdon
- Structural Biology of DNA-Damage Signalling Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK.
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Agúndez M, Cernicharo J, Quintana-Lacaci G, Castro-Carrizo A, Velilla Prieto L, Marcelino N, Guélin M, Joblin C, Martín-Gago JA, Gottlieb CA, Patel NA, McCarthy MC. The growth of carbon chains in IRC +10216 mapped with ALMA. Astron Astrophys 2017; 601:A4. [PMID: 28469283 PMCID: PMC5405872 DOI: 10.1051/0004-6361/201630274] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Linear carbon chains are common in various types of astronomical molecular sources. Possible formation mechanisms involve both bottom-up and top-down routes. We have carried out a combined observational and modeling study of the formation of carbon chains in the C-star envelope IRC +10216, where the polymerization of acetylene and hydrogen cyanide induced by ultraviolet photons can drive the formation of linear carbon chains of increasing length. We have used ALMA to map the emission of λ 3 mm rotational lines of the hydrocarbon radicals C2H, C4H, and C6H, and the CN-containing species CN, C3N, HC3N, and HC5N with an angular resolution of ~1″. The spatial distribution of all these species is a hollow, 5-10″ wide, spherical shell located at a radius of 10-20″ from the star, with no appreciable emission close to the star. Our observations resolve the broad shell of carbon chains into thinner sub-shells which are 1-2″ wide and not fully concentric, indicating that the mass loss process has been discontinuous and not fully isotropic. The radial distributions of the species mapped reveal subtle differences: while the hydrocarbon radicals have very similar radial distributions, the CN-containing species show more diverse distributions, with HC3N appearing earlier in the expansion and the radical CN extending later than the rest of the species. The observed morphology can be rationalized by a chemical model in which the growth of polyynes is mainly produced by rapid gas-phase chemical reactions of C2H and C4H radicals with unsaturated hydrocarbons, while cyanopolyynes are mainly formed from polyynes in gas-phase reactions with CN and C3N radicals.
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Affiliation(s)
- M Agúndez
- Instituto de Ciencia de Materiales de Madrid, CSIC, C/ Sor Juana Inés de la Cruz 3, 28049 Cantoblanco, Spain
| | - J Cernicharo
- Instituto de Ciencia de Materiales de Madrid, CSIC, C/ Sor Juana Inés de la Cruz 3, 28049 Cantoblanco, Spain
| | - G Quintana-Lacaci
- Instituto de Ciencia de Materiales de Madrid, CSIC, C/ Sor Juana Inés de la Cruz 3, 28049 Cantoblanco, Spain
| | - A Castro-Carrizo
- Institut de Radioastronomie Millimétrique, 300 rue de la Piscine, 38406 St. Martin d'Héres, France
| | - L Velilla Prieto
- Instituto de Ciencia de Materiales de Madrid, CSIC, C/ Sor Juana Inés de la Cruz 3, 28049 Cantoblanco, Spain
| | - N Marcelino
- Instituto de Ciencia de Materiales de Madrid, CSIC, C/ Sor Juana Inés de la Cruz 3, 28049 Cantoblanco, Spain
| | - M Guélin
- Institut de Radioastronomie Millimétrique, 300 rue de la Piscine, 38406 St. Martin d'Héres, France
| | - C Joblin
- Université de Toulouse, UPS-OMS, IRAP, 31000 Toulouse, France
- CNRS, IRAP, 9 Av. Colonel Roche, BP 44346, 31028 Toulouse Cedex 4, France
| | - J A Martín-Gago
- Instituto de Ciencia de Materiales de Madrid, CSIC, C/ Sor Juana Inés de la Cruz 3, 28049 Cantoblanco, Spain
| | - C A Gottlieb
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
| | - N A Patel
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
| | - M C McCarthy
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
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7
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Lai AL, Clerico EM, Blackburn ME, Patel NA, Robinson CV, Borbat PP, Freed JH, Gierasch LM. Key features of an Hsp70 chaperone allosteric landscape revealed by ion-mobility native mass spectrometry and double electron-electron resonance. J Biol Chem 2017; 292:8773-8785. [PMID: 28428246 PMCID: PMC5448104 DOI: 10.1074/jbc.m116.770404] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 04/12/2017] [Indexed: 11/06/2022] Open
Abstract
Proteins are dynamic entities that populate conformational ensembles, and most functions of proteins depend on their dynamic character. Allostery, in particular, relies on ligand-modulated shifts in these conformational ensembles. Hsp70s are allosteric molecular chaperones with conformational landscapes that involve large rearrangements of their two domains (viz. the nucleotide-binding domain and substrate-binding domain) in response to adenine nucleotides and substrates. However, it remains unclear how the Hsp70 conformational ensemble is populated at each point of the allosteric cycle and how ligands control these populations. We have mapped the conformational species present under different ligand-binding conditions throughout the allosteric cycle of the Escherichia coli Hsp70 DnaK by two complementary methods, ion-mobility mass spectrometry and double electron-electron resonance. Our results obtained under biologically relevant ligand-bound conditions confirm the current picture derived from NMR and crystallographic data of domain docking upon ATP binding and undocking in response to ADP and substrate. Additionally, we find that the helical lid of DnaK is a highly dynamic unit of the structure in all ligand-bound states. Importantly, we demonstrate that DnaK populates a partially docked state in the presence of ATP and substrate and that this state represents an energy minimum on the DnaK allosteric landscape. Because Hsp70s are emerging as potential drug targets for many diseases, fully mapping an allosteric landscape of a molecular chaperone like DnaK will facilitate the development of small molecules that modulate Hsp70 function via allosteric mechanisms.
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Affiliation(s)
- Alex L Lai
- From the Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-2703
| | | | - Mandy E Blackburn
- the School of Environmental, Physical, and Applied Sciences, University of Central Missouri, Warrensburg, Missouri 64093, and
| | - Nisha A Patel
- the Physical and Theoretical Chemistry Laboratory, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Carol V Robinson
- the Physical and Theoretical Chemistry Laboratory, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Peter P Borbat
- From the Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-2703
| | - Jack H Freed
- From the Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-2703
| | - Lila M Gierasch
- the Departments of Biochemistry and Molecular Biology and .,Chemistry, University of Massachusetts, Amherst, Massachusetts 01003
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8
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Aguilar-Gurrieri C, Larabi A, Vinayachandran V, Patel NA, Yen K, Reja R, Ebong IO, Schoehn G, Robinson CV, Pugh BF, Panne D. Structural evidence for Nap1-dependent H2A-H2B deposition and nucleosome assembly. EMBO J 2016; 35:1465-82. [PMID: 27225933 PMCID: PMC4931181 DOI: 10.15252/embj.201694105] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 04/21/2016] [Indexed: 11/25/2022] Open
Abstract
Nap1 is a histone chaperone involved in the nuclear import of H2A–H2B and nucleosome assembly. Here, we report the crystal structure of Nap1 bound to H2A–H2B together with in vitro and in vivo functional studies that elucidate the principles underlying Nap1‐mediated H2A–H2B chaperoning and nucleosome assembly. A Nap1 dimer provides an acidic binding surface and asymmetrically engages a single H2A–H2B heterodimer. Oligomerization of the Nap1–H2A–H2B complex results in burial of surfaces required for deposition of H2A–H2B into nucleosomes. Chromatin immunoprecipitation‐exonuclease (ChIP‐exo) analysis shows that Nap1 is required for H2A–H2B deposition across the genome. Mutants that interfere with Nap1 oligomerization exhibit severe nucleosome assembly defects showing that oligomerization is essential for the chaperone function. These findings establish the molecular basis for Nap1‐mediated H2A–H2B deposition and nucleosome assembly.
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Affiliation(s)
- Carmen Aguilar-Gurrieri
- European Molecular Biology Laboratory, Grenoble, France Unit for Virus Host-Cell Interactions, Univ. Grenoble Alpes-EMBL-CNRS, Grenoble, France
| | - Amédé Larabi
- European Molecular Biology Laboratory, Grenoble, France Unit for Virus Host-Cell Interactions, Univ. Grenoble Alpes-EMBL-CNRS, Grenoble, France
| | - Vinesh Vinayachandran
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA
| | - Nisha A Patel
- Department of Chemistry, University of Oxford, Oxford, UK
| | - Kuangyu Yen
- Department of Cell Biology, Southern Medical University, Guangzhou, China
| | - Rohit Reja
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA
| | - Ima-O Ebong
- Department of Chemistry, University of Oxford, Oxford, UK
| | - Guy Schoehn
- Unit for Virus Host-Cell Interactions, Univ. Grenoble Alpes-EMBL-CNRS, Grenoble, France Université Grenoble-Alpes, Grenoble, France Centre National de la Recherche Scientifique (CNRS) IBS, Grenoble, France CEA, IBS, Grenoble, France
| | | | - B Franklin Pugh
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA
| | - Daniel Panne
- European Molecular Biology Laboratory, Grenoble, France Unit for Virus Host-Cell Interactions, Univ. Grenoble Alpes-EMBL-CNRS, Grenoble, France
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9
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Wang A, Yue F, Li Y, Xie R, Harper T, Patel NA, Muth K, Palmer J, Qiu Y, Wang J, Lam DK, Raum JC, Stoffers DA, Ren B, Sander M. Epigenetic priming of enhancers predicts developmental competence of hESC-derived endodermal lineage intermediates. Cell Stem Cell 2016; 16:386-99. [PMID: 25842977 DOI: 10.1016/j.stem.2015.02.013] [Citation(s) in RCA: 166] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2014] [Revised: 11/23/2014] [Accepted: 02/17/2015] [Indexed: 01/09/2023]
Abstract
Embryonic development relies on the capacity of progenitor cells to appropriately respond to inductive cues, a cellular property known as developmental competence. Here, we report that epigenetic priming of enhancers signifies developmental competence during endodermal lineage diversification. Chromatin mapping during pancreatic and hepatic differentiation of human embryonic stem cells revealed the en masse acquisition of a poised chromatin state at enhancers specific to endoderm-derived cell lineages in gut tube intermediates. Experimentally, the acquisition of this poised enhancer state predicts the ability of endodermal intermediates to respond to inductive signals. Furthermore, these enhancers are first recognized by the pioneer transcription factors FOXA1 and FOXA2 when competence is acquired, while subsequent recruitment of lineage-inductive transcription factors, such as PDX1, leads to enhancer and target gene activation. Together, our results identify the acquisition of a poised chromatin state at enhancers as a mechanism by which progenitor cells acquire developmental competence.
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Affiliation(s)
- Allen Wang
- Pediatric Diabetes Research Center, Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093-0983, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA
| | - Feng Yue
- Department of Biochemistry and Molecular Biology, College of Medicine, The Pennsylvania State University, Hershey, PA 17033, USA
| | - Yan Li
- Ludwig Institute for Cancer Research, La Jolla, CA 92093-0653, USA
| | - Ruiyu Xie
- Pediatric Diabetes Research Center, Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093-0983, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA
| | - Thomas Harper
- Pediatric Diabetes Research Center, Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093-0983, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA
| | - Nisha A Patel
- Pediatric Diabetes Research Center, Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093-0983, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA
| | - Kayla Muth
- Pediatric Diabetes Research Center, Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093-0983, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA
| | - Jeffrey Palmer
- Pediatric Diabetes Research Center, Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093-0983, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA
| | - Yunjiang Qiu
- Ludwig Institute for Cancer Research, La Jolla, CA 92093-0653, USA
| | - Jinzhao Wang
- Pediatric Diabetes Research Center, Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093-0983, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA
| | - Dieter K Lam
- Pediatric Diabetes Research Center, Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093-0983, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA
| | - Jeffrey C Raum
- Division of Endocrinology, Diabetes, and Metabolism, Institute for Diabetes, Obesity and Metabolism, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Doris A Stoffers
- Division of Endocrinology, Diabetes, and Metabolism, Institute for Diabetes, Obesity and Metabolism, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Bing Ren
- Ludwig Institute for Cancer Research, La Jolla, CA 92093-0653, USA; Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093-0651, USA; Institute of Genomic Medicine, University of California, San Diego, La Jolla, CA 92093-0761, USA; Moores Cancer Center, University of California San Diego, La Jolla, CA 92093-0653, USA.
| | - Maike Sander
- Pediatric Diabetes Research Center, Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093-0983, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA; Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093-0651, USA; Institute of Genomic Medicine, University of California, San Diego, La Jolla, CA 92093-0761, USA; Moores Cancer Center, University of California San Diego, La Jolla, CA 92093-0653, USA.
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10
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Lercher L, Raj R, Patel NA, Price J, Mohammed S, Robinson CV, Schofield CJ, Davis BG. Generation of a synthetic GlcNAcylated nucleosome reveals regulation of stability by H2A-Thr101 GlcNAcylation. Nat Commun 2015; 6:7978. [PMID: 26305776 PMCID: PMC4560749 DOI: 10.1038/ncomms8978] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 07/02/2015] [Indexed: 02/06/2023] Open
Abstract
O-GlcNAcylation is a newly discovered histone modification implicated in transcriptional regulation, but no structural information on the physical effect of GlcNAcylation on chromatin exists. Here, we generate synthetic, pure GlcNAcylated histones and nucleosomes and reveal that GlcNAcylation can modulate structure through direct destabilization of H2A/H2B dimers in the nucleosome, thus promoting an 'open' chromatin state. The results suggest that a plausible molecular basis for one role of histone O-GlcNAcylation in epigenetic regulation is to lower the barrier for RNA polymerase passage and hence increase transcription.
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Affiliation(s)
- Lukas Lercher
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford OX1 3TA, UK
| | - Ritu Raj
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford OX1 3TA, UK
| | - Nisha A. Patel
- Department of Chemistry, University of Oxford, Physical and Theoretical Chemistry Laboratory, South Parks Road, Oxford OX1 3QZ, UK
| | - Joshua Price
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford OX1 3TA, UK
| | - Shabaz Mohammed
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford OX1 3TA, UK
| | - Carol V. Robinson
- Department of Chemistry, University of Oxford, Physical and Theoretical Chemistry Laboratory, South Parks Road, Oxford OX1 3QZ, UK
| | - Christopher J. Schofield
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford OX1 3TA, UK
| | - Benjamin G. Davis
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford OX1 3TA, UK
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11
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Cernicharo J, McCarthy MC, Gottlieb CA, Agúndez M, Velilla Prieto L, Baraban JH, Changala PB, Guélin M, Kahane C, Martin-Drumel MA, Patel NA, Reilly NJ, Stanton JF, Quintana-Lacaci G, Thorwirth S, Young KH. Discovery of SiCSi in IRC +10216: A missing link between gas and dust carriers of Si-C bonds. Astrophys J Lett 2015; 806:L3. [PMID: 26722621 PMCID: PMC4693961 DOI: 10.1088/2041-8205/806/1/l3] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We report the discovery in space of a disilicon species, SiCSi, from observations between 80 and 350 GHz with the IRAM 30m radio telescope. Owing to the close coordination between laboratory experiments and astrophysics, 112 lines have now been detected in the carbon-rich star CW Leo. The derived frequencies yield improved rotational and centrifugal distortion constants up to sixth order. From the line profiles and interferometric maps with the Submillimeter Array, the bulk of the SiCSi emission arises from a region of 6″ in radius. The derived abundance is comparable to that of SiC2. As expected from chemical equilibrium calculations, SiCSi and SiC2 are the most abundant species harboring a Si-C bond in the dust formation zone and certainly both play a key role in the formation of SiC dust grains.
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Affiliation(s)
- J Cernicharo
- Group of Molecular Astrophysics. ICMM. CSIC. C/Sor Juana Inés de La Cruz N3. E-28049, Madrid. Spain
| | - M C McCarthy
- Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, and School of Engineering & Applied Sciences, Harvard University, Cambridge, MA 02138
| | - C A Gottlieb
- Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, and School of Engineering & Applied Sciences, Harvard University, Cambridge, MA 02138
| | - M Agúndez
- Group of Molecular Astrophysics. ICMM. CSIC. C/Sor Juana Inés de La Cruz N3. E-28049, Madrid. Spain
| | - L Velilla Prieto
- Group of Molecular Astrophysics. ICMM. CSIC. C/Sor Juana Inés de La Cruz N3. E-28049, Madrid. Spain
| | - J H Baraban
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO 80309
| | - P B Changala
- JILA, National Institute of Standards and Technology and University of Colorado, and Department of Physics, University of Colorado, Boulder, CO 80309
| | - M Guélin
- Institut de Radioastronomie Millimétrique, 300 rue de la Piscine, F-38406, St-Martin d'Hères, France
| | - C Kahane
- Universit Grenoble Alpes, IPAG, F-38000 Grenoble, France; CNRS, IPAG, F-38000 Grenoble, France
| | - M A Martin-Drumel
- Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, and School of Engineering & Applied Sciences, Harvard University, Cambridge, MA 02138
| | - N A Patel
- Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, and School of Engineering & Applied Sciences, Harvard University, Cambridge, MA 02138
| | - N J Reilly
- Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, and School of Engineering & Applied Sciences, Harvard University, Cambridge, MA 02138
| | - J F Stanton
- Institute for Theoretical Chemistry, Department of Chemistry, The University of Texas at Austin, Austin, TX 78712
| | - G Quintana-Lacaci
- Group of Molecular Astrophysics. ICMM. CSIC. C/Sor Juana Inés de La Cruz N3. E-28049, Madrid. Spain
| | - S Thorwirth
- I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany
| | - K H Young
- Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, and School of Engineering & Applied Sciences, Harvard University, Cambridge, MA 02138
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12
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Urnavicius L, Zhang K, Diamant AG, Motz C, Schlager MA, Yu M, Patel NA, Robinson CV, Carter AP. The structure of the dynactin complex and its interaction with dynein. Science 2015; 347:1441-1446. [PMID: 25814576 DOI: 10.1126/science.aaa4080] [Citation(s) in RCA: 267] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Dynactin is an essential cofactor for the microtubule motor cytoplasmic dynein-1. We report the structure of the 23-subunit dynactin complex by cryo-electron microscopy to 4.0 angstroms. Our reconstruction reveals how dynactin is built around a filament containing eight copies of the actin-related protein Arp1 and one of β-actin. The filament is capped at each end by distinct protein complexes, and its length is defined by elongated peptides that emerge from the α-helical shoulder domain. A further 8.2 angstrom structure of the complex between dynein, dynactin, and the motility-inducing cargo adaptor Bicaudal-D2 shows how the translational symmetry of the dynein tail matches that of the dynactin filament. The Bicaudal-D2 coiled coil runs between dynein and dynactin to stabilize the mutually dependent interactions between all three components.
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Affiliation(s)
- Linas Urnavicius
- Medical Research Council Laboratory of Molecular Biology, Division of Structural Studies, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Kai Zhang
- Medical Research Council Laboratory of Molecular Biology, Division of Structural Studies, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Aristides G Diamant
- Medical Research Council Laboratory of Molecular Biology, Division of Structural Studies, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Carina Motz
- Medical Research Council Laboratory of Molecular Biology, Division of Structural Studies, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Max A Schlager
- Medical Research Council Laboratory of Molecular Biology, Division of Structural Studies, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Minmin Yu
- Medical Research Council Laboratory of Molecular Biology, Division of Structural Studies, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Nisha A Patel
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, UK
| | - Carol V Robinson
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, UK
| | - Andrew P Carter
- Medical Research Council Laboratory of Molecular Biology, Division of Structural Studies, Francis Crick Avenue, Cambridge, CB2 0QH, UK
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13
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Puno MR, Patel NA, Møller SG, Robinson CV, Moody PCE, Odell M. Structure of Cu(I)-bound DJ-1 reveals a biscysteinate metal binding site at the homodimer interface: insights into mutational inactivation of DJ-1 in Parkinsonism. J Am Chem Soc 2013; 135:15974-7. [PMID: 24144264 DOI: 10.1021/ja406010m] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The Parkinsonism-associated protein DJ-1 has been suggested to activate the Cu-Zn superoxide dismutase (SOD1) by providing its copper cofactor. The structural and chemical means by which DJ-1 could support this function is unknown. In this study, we characterize the molecular interaction of DJ-1 with Cu(I). Mass spectrometric analysis indicates binding of one Cu(I) ion per DJ-1 homodimer. The crystal structure of DJ-1 bound to Cu(I) confirms metal coordination through a docking accessible biscysteinate site formed by juxtaposed cysteine residues at the homodimer interface. Spectroscopy in crystallo validates the identity and oxidation state of the bound metal. The measured subfemtomolar dissociation constant (Kd = 6.41 × 10(-16) M) of DJ-1 for Cu(I) supports the physiological retention of the metal ion. Our results highlight the requirement of a stable homodimer for copper binding by DJ-1. Parkinsonism-linked mutations that weaken homodimer interactions will compromise this capability.
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Affiliation(s)
- M Rhyan Puno
- Department of Molecular and Applied Biosciences, University of Westminster , 115 New Cavendish Street, London W1W 6UW, United Kingdom
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14
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Beale K, Gardiner JV, Bewick GA, Hostomska K, Patel NA, Hussain SS, Jayasena CN, Ebling FJP, Jethwa PH, Prosser HM, Lattanzi R, Negri L, Ghatei MA, Bloom SR, Dhillo WS. Peripheral administration of prokineticin 2 potently reduces food intake and body weight in mice via the brainstem. Br J Pharmacol 2013; 168:403-10. [PMID: 22935107 DOI: 10.1111/j.1476-5381.2012.02191.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Revised: 08/02/2012] [Accepted: 08/06/2012] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND AND PURPOSE Prokineticin 2 (PK2) has recently been shown to acutely reduce food intake in rodents. We aimed to determine the CNS sites and receptors that mediate the anorectic effects of peripherally administered PK2 and its chronic effects on glucose and energy homeostasis. EXPERIMENTAL APPROACH We investigated neuronal activation following i.p. administration of PK2 using c-Fos-like immunoreactivity (CFL-IR). The anorectic effect of PK2 was examined in mice with targeted deletion of either prokineticin receptor 1 (PKR1) or prokineticin receptor 2 (PKR2), and in wild-type mice following administration of the PKR1 antagonist, PC1. The effect of IP PK2 administration on glucose homeostasis was investigated. Finally, the effect of long-term administration of PK2 on glucose and energy homeostasis in diet-induced obese (DIO) mice was determined. KEY RESULTS I.p. PK2 administration significantly increased CFL-IR in the dorsal motor vagal nucleus of the brainstem. The anorectic effect of PK2 was maintained in mice lacking the PKR2 but abolished in mice lacking PKR1 and in wild-type mice pre-treated with PC1. DIO mice treated chronically with PK2 had no changes in glucose levels but significantly reduced food intake and body weight compared to controls. CONCLUSIONS AND IMPLICATIONS Together, our data suggest that the anorectic effects of peripherally administered PK2 are mediated via the brainstem and this effect requires PKR1 but not PKR2 signalling. Chronic administration of PK2 reduces food intake and body weight in a mouse model of human obesity, suggesting that PKR1-selective agonists have potential to be novel therapeutics for the treatment of obesity.
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Affiliation(s)
- Kel Beale
- Section of Investigative Medicine, Imperial College London, London, UK
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15
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Xie R, Everett LJ, Lim HW, Patel NA, Schug J, Kroon E, Kelly OG, Wang A, D'Amour KA, Robins AJ, Won KJ, Kaestner KH, Sander M. Dynamic chromatin remodeling mediated by polycomb proteins orchestrates pancreatic differentiation of human embryonic stem cells. Cell Stem Cell 2013; 12:224-37. [PMID: 23318056 DOI: 10.1016/j.stem.2012.11.023] [Citation(s) in RCA: 183] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Revised: 10/30/2012] [Accepted: 11/30/2012] [Indexed: 02/06/2023]
Abstract
Embryonic development is characterized by dynamic changes in gene expression, yet the role of chromatin remodeling in these cellular transitions remains elusive. To address this question, we profiled the transcriptome and select chromatin modifications at defined stages during pancreatic endocrine differentiation of human embryonic stem cells. We identify removal of Polycomb group (PcG)-mediated repression on stage-specific genes as a key mechanism for the induction of developmental regulators. Furthermore, we discover that silencing of transitory genes during lineage progression associates with reinstatement of PcG-dependent repression. Significantly, in vivo- but not in vitro-differentiated endocrine cells exhibit close similarity to primary human islets in regard to transcriptome and chromatin structure. We further demonstrate that endocrine cells produced in vitro do not fully eliminate PcG-mediated repression on endocrine-specific genes, probably contributing to their malfunction. These studies reveal dynamic chromatin remodeling during developmental lineage progression and identify possible strategies for improving cell differentiation in culture.
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Affiliation(s)
- Ruiyu Xie
- Department of Pediatrics and Cellular & Molecular Medicine, University of California San Diego, La Jolla, CA 92093-0695, USA
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16
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Patel NA, Crombie A, Slade SE, Thalassinos K, Hughes C, Connolly JB, Langridge J, Murrell JC, Scrivens JH. Comparison of One- and Two-dimensional Liquid Chromatography Approaches in the Label-free Quantitative Analysis of Methylocella silvestris. J Proteome Res 2012; 11:4755-63. [DOI: 10.1021/pr300253s] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Nisha A. Patel
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Andrew Crombie
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Susan E. Slade
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom
| | | | - Chris Hughes
- Waters Corporation, Atlas Park, Simonsway, Manchester, M22 5PP, United Kingdom
| | - Joanne B. Connolly
- Waters Corporation, Atlas Park, Simonsway, Manchester, M22 5PP, United Kingdom
| | - James Langridge
- Waters Corporation, Atlas Park, Simonsway, Manchester, M22 5PP, United Kingdom
| | - J. Colin Murrell
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - James H. Scrivens
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom
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17
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Seymour PA, Shih HP, Patel NA, Freude KK, Xie R, Lim CJ, Sander M. A Sox9/Fgf feed-forward loop maintains pancreatic organ identity. Development 2012; 139:3363-72. [PMID: 22874919 DOI: 10.1242/dev.078733] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
All mature pancreatic cell types arise from organ-specific multipotent progenitor cells. Although previous studies have identified cell-intrinsic and -extrinsic cues for progenitor cell expansion, it is unclear how these cues are integrated within the niche of the developing organ. Here, we present genetic evidence in mice that the transcription factor Sox9 forms the centerpiece of a gene regulatory network that is crucial for proper organ growth and maintenance of organ identity. We show that pancreatic progenitor-specific ablation of Sox9 during early pancreas development causes pancreas-to-liver cell fate conversion. Sox9 deficiency results in cell-autonomous loss of the fibroblast growth factor receptor (Fgfr) 2b, which is required for transducing mesenchymal Fgf10 signals. Likewise, Fgf10 is required to maintain expression of Sox9 and Fgfr2 in epithelial progenitors, showing that Sox9, Fgfr2 and Fgf10 form a feed-forward expression loop in the early pancreatic organ niche. Mirroring Sox9 deficiency, perturbation of Fgfr signaling in pancreatic explants or genetic inactivation of Fgf10 also result in hepatic cell fate conversion. Combined with previous findings that Fgfr2b or Fgf10 are necessary for pancreatic progenitor cell proliferation, our results demonstrate that organ fate commitment and progenitor cell expansion are coordinately controlled by the activity of a Sox9/Fgf10/Fgfr2b feed-forward loop in the pancreatic niche. This self-promoting Sox9/Fgf10/Fgfr2b loop may regulate cell identity and organ size in a broad spectrum of developmental and regenerative contexts.
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Affiliation(s)
- Philip A Seymour
- Departments of Pediatrics and Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA 92093-0695, USA
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18
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Dubois CL, Shih HP, Seymour PA, Patel NA, Behrmann JM, Ngo V, Sander M. Sox9-haploinsufficiency causes glucose intolerance in mice. PLoS One 2011; 6:e23131. [PMID: 21829703 PMCID: PMC3149078 DOI: 10.1371/journal.pone.0023131] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Accepted: 07/07/2011] [Indexed: 01/08/2023] Open
Abstract
The HMG box transcription factor Sox9 plays a critical role in progenitor cell expansion during pancreas organogenesis and is required for proper endocrine cell development in the embryo. Based on in vitro studies it has been suggested that Sox9 controls expression of a network of important developmental regulators, including Tcf2/MODY5, Hnf6, and Foxa2, in pancreatic progenitor cells. Here, we sought to: 1) determine whether Sox9 regulates this transcriptional network in vivo and 2) investigate whether reduced Sox9 gene dosage leads to impaired glucose homeostasis in adult mice. Employing two genetic models of temporally-controlled Sox9 inactivation in pancreatic progenitor cells, we demonstrate that contrary to in vitro findings, Sox9 is not required for Tcf2, Hnf6, or Foxa2 expression in vivo. Moreover, our analysis revealed a novel role for Sox9 in maintaining the expression of Pdx1/MODY4, which is an important transcriptional regulator of beta-cell development. We further show that reduced beta-cell mass in Sox9-haploinsufficient mice leads to glucose intolerance during adulthood. Sox9-haploinsufficient mice displayed 50% reduced beta-cell mass at birth, which recovered partially via a compensatory increase in beta-cell proliferation early postnatally. Endocrine islets from mice with reduced Sox9 gene dosage exhibited normal glucose stimulated insulin secretion. Our findings show Sox9 plays an important role in endocrine development by maintaining Ngn3 and Pdx1 expression. Glucose intolerance in Sox9-haploinsufficient mice suggests that mutations in Sox9 could play a role in diabetes in humans.
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Affiliation(s)
- Claire L. Dubois
- Department of Pediatrics and Cellular & Molecular Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Hung Ping Shih
- Department of Pediatrics and Cellular & Molecular Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Philip A. Seymour
- Department of Pediatrics and Cellular & Molecular Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Nisha A. Patel
- Department of Pediatrics and Cellular & Molecular Medicine, University of California San Diego, La Jolla, California, United States of America
| | - James M. Behrmann
- Department of Pediatrics and Cellular & Molecular Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Victoria Ngo
- Department of Pediatrics and Cellular & Molecular Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Maike Sander
- Department of Pediatrics and Cellular & Molecular Medicine, University of California San Diego, La Jolla, California, United States of America
- * E-mail:
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19
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Gardiner JV, Beale KE, Roy D, Boughton CK, Bataveljic A, Campbell DC, Bewick GA, Patel NA, Patterson M, Leavy EM, Ghatei MA, Bloom SR, Dhillo WS. Cerebellin1 is a novel orexigenic peptide. Diabetes Obes Metab 2010; 12:883-90. [PMID: 20920041 DOI: 10.1111/j.1463-1326.2010.01247.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
AIM Cerebellin1 (Cbln1) is highly expressed in the hypothalamus, a region of the brain involved in appetite regulation. However, the effects of Cbn1 on food intake are not known. The present study aimed to investigate the effect of Cbln1 on appetite regulation in rats. METHODS We determined the effect of (i) intracerebroventricular (ICV) injection of Cbln1 on food intake, behaviour and plasma pituitary hormone levels in male Wistar rats; (ii) Cbln1 on the release of hypothalamic neuropeptides known to modulate food intake from hypothalamic explants and (iii) fasting on hypothalamic Cbln1 mRNA expression. RESULTS (i) ICV administration of Cbln1 significantly increased food intake in rats and caused no adverse behaviours. ICV administration of Cbln1 significantly reduced plasma thyroid stimulating hormone (TSH) levels 10 min postinjection in rats. (ii) Cbln1 significantly increased the release of neuropeptide Y (NPY) from hypothalamic explants. (iii) Cbln1 mRNA expression levels were increased in the ventromedial nucleus of the hypothalamus in fasted rats. CONCLUSIONS These data suggest that Cbln1 is a novel orexigenic peptide, which may mediate its effects via hypothalamic NPY.
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Affiliation(s)
- J V Gardiner
- Department of Investigative Medicine, Hammersmith Hospital, Imperial College London, London, UK
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20
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Patel NA, Patel NJ, Patel RP. Comparative development and evaluation of topical gel and cream formulations of psoralen. Drug Discov Ther 2009; 3:234-242. [PMID: 22495634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The aim of the present investigation is to develop topical gel and cream formulations of psoralen for enhancing its transport through the skin, with the goal to shorten the delay between drug application and UVA irradiation. In our first studies, oil-in-water (O/W) creams of psoralen (0.05% concentration) were prepared using Apifil (PEG-8 Beeswax) and Plurol Stearique WL 1009 as emulsifying agents and aqueous cream (British Pharmaceutical Codex) as the cream base material. In our second studies, hydroalcoholic transparent gel formulations of this drug in a 0.05% concentration were prepared using hydroxypropylcellulose (HPC) as the gelling agent. The physicochemical compatibility between psoralen and formulation excipients used in the cream and gel formulations was confirmed by using differential scanning calorimetry and Fourier transform infrared spectroscopy. All prepared cream and gel formulations were evaluated for drug content uniformity, viscosity, pH, stability, and limpidity. The release of psoralen from all formulations via dialysis through a cellulose membrane into phosphate buffer pH 6.8 at 37°C was studied. The penetration enhancing effect of menthol (0-12.5%, w/w) on the percutaneous flux of psoralen through excised rat epidermis from gel and cream formulations was also investigated. The release profile of psoralen from gel formulations was higher than that from cream formulations. The percutaneous flux and enhancement ratio of psoralen across rat epidermis was significantly enhanced by the addition of menthol in both gel and cream formulations as compared to gel and cream formulations prepared without menthol (p < 0.05).
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Affiliation(s)
- N A Patel
- S. K. Patel College of Pharmaceutical Education and Research, Ganpat University, Gujarat, India
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21
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Kleiman E, Carter G, Ghansah T, Patel NA, Cooper DR. Developmentally spliced PKCbetaII provides a possible link between mTORC2 and Akt kinase to regulate 3T3-L1 adipocyte insulin-stimulated glucose transport. Biochem Biophys Res Commun 2009; 388:554-9. [PMID: 19686698 DOI: 10.1016/j.bbrc.2009.08.063] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2009] [Accepted: 08/07/2009] [Indexed: 12/22/2022]
Abstract
Functional adipocyte glucose disposal is a key component of global glucose homeostasis. PKCbetaII is involved in rat skeletal muscle cell ISGT. Western blot analysis and real-time PCR revealed 3T3-L1 cells developmentally regulated PKCbeta splicing such that PKCbetaI was downregulated and PKCbetaII was upregulated during the course of differentiation. An initial glucose uptake screen using PKC inhibitor LY379196 pointed to a PKC isozyme other than PKCzeta mediating 3T3-L1 adipocyte ISGT. Subsequent use of PKCbetaII inhibitor CGP53353 pointed to a role for PKCbetaII in ISGT. Western blot analysis showed that CGP53353 specifically inhibited phosphorylation of PKCbetaII Serine 660. Subcellular fractionation and immunofluorescence demonstrated that PKCbetaII regulates GLUT4 translocation. Further Western blot, immunofluorescence and co-immunoprecipitation analysis reveal that PKCbetaII inhibition does not affect mTORC2 activity yet abrogates phosphorylation of Akt Serine 473. PKCbetaII regulates GLUT4 translocation by regulating Akt phosphorylation and thus activity.
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Affiliation(s)
- E Kleiman
- Department of Molecular Medicine, College of Medicine, University of South Florida, The Research Service, James A. Haley Veterans Hospital, Tampa, FL 33612, USA
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22
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Dhillo WS, Bewick GA, White NE, Gardiner JV, Thompson EL, Bataveljic A, Murphy KG, Roy D, Patel NA, Scutt JN, Armstrong A, Ghatei MA, Bloom SR. The thyroid hormone derivative 3-iodothyronamine increases food intake in rodents. Diabetes Obes Metab 2009; 11:251-60. [PMID: 18671794 DOI: 10.1111/j.1463-1326.2008.00935.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND The thyroid hormone derivative 3-iodothyronamine (T(1)AM), an endogenous biogenic amine, is a potent agonist of the G protein-coupled trace amine-associated receptor 1 (TAAR1). T(1)AM is present in rat brain, and TAAR1 is expressed in hypothalamic nuclei associated with the regulation of energy homeostasis. AIM The aim of this study was to determine the effects of T(1)AM on food intake in rodents. METHODS We determined the effect of (i) intraperitoneal (i.p.) administration of T(1)AM on food intake, oxygen consumption (VO(2)) and locomotor activity in mice; (ii) intracerebroventricular (ICV) injection of T(1)AM on food intake in male rats; (iii) c-fos expression following ventricular administration of T(1)AM in male rats; and (iv) direct injection of T(1)AM into the arcuate nucleus (ARC) of male rats on food intake. RESULTS (i) T(1)AM (4 nmol/kg) significantly increased food intake following i.p. injection in mice but had no effect on VO(2) or locomotor activity. (ii) ICV administration of T(1)AM (1.2 nmol/kg) significantly increased food intake in male rats. (iii) Intraventricular administration of T(1)AM significantly increased c-fos expression in the ARC of male rats. (iv) Direct administration of T(1)AM (0.12, 0.4 and 1.2 nmol/kg) into the ARC of male rats significantly increased food intake. CONCLUSION These data suggest that T(1)AM is an orexigenic factor that may act through the ARC to increase food intake in rodents.
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Affiliation(s)
- W S Dhillo
- Department of Investigative Medicine, Faculty of Medicine, Imperial College London, Hammersmith Hospital, London, UK
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23
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Syed MI, Patel NA, Jan S, Shaikh A, Grunden B, Morar K. Symptomatic refractures after vertebroplasty in patients with steroid-induced osteoporosis. AJNR Am J Neuroradiol 2006; 27:1938-43. [PMID: 17032871 PMCID: PMC7977917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
BACKGROUND AND PURPOSE Refracture after percutaneous vertebroplasty in patients receiving oral glucocorticoid therapy has caused some patients and referring physicians to have negative perceptions concerning the efficacy of the initial vertebroplasty treatment. The purpose of this study was to analyze symptomatic refractures after vertebroplasty in patients on oral steroid therapy. We hypothesized that the higher refracture rate of patients on oral glucocorticoid therapy after percutaneous vertebroplasty is due not to an inadequacy of the procedure but rather to a naturally higher predisposition of these patients to refracture compared with patients with primary osteoporosis. METHODS A retrospective analysis was performed on all osteoporosis patients having initial vertebroplasty from August 1999 to August 2003. The follow-up period was limited to 1 year after initial vertebroplasty session, with the last follow-up date ending in August 2004. Data were collected on 387 osteoporosis patients. RESULTS Of the patients with primary osteoporosis, 20.6% patients refractured whereas 37.8% of the patients with steroid-induced osteoporosis had symptomatic refractures within 1 year of initial vertebroplasty. Relative risk of refracture within 1 year for the patients with steroid-induced osteoporosis was 1.84 compared with the patients with primary osteoporosis. In addition, the patients with steroid-induced osteoporosis were more likely to refracture after their second treatment session (within 1 year of initial vertebroplasty) than those with primary osteoporosis. CONCLUSION Patients presenting on oral steroid therapy at their initial vertebroplasty are almost twice more likely to have symptomatic refractures than primary osteoporosis patients within 1 year of initial vertebroplasty.
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Affiliation(s)
- M I Syed
- Department of Radiology, Mercy Medical Center, Springfield, Ohio, 45501-1380, USA.
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24
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Syed MI, Jan S, Patel NA, Shaikh A, Marsh RA, Stewart RV. Fatal fat embolism after vertebroplasty: identification of the high-risk patient. AJNR Am J Neuroradiol 2006; 27:343-5. [PMID: 16484407 PMCID: PMC8148788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
We report a rare complication of autopsy-proven fat and bone marrow embolization following percutaneous vertebroplasty in a patient who had no evidence of cement leakage. Cement injection was done during one patient encounter, covering 3 vertebral levels by using a unipedicular approach. Patients may have complications even without polymethylmethacrylate leakage.
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Affiliation(s)
- M I Syed
- Department of Radiology, Mercy Medical Center, Springfield, Ohio 45501-1308, USA
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25
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Patel NA, Parekh H, Vasavada DP, Mehta SG, Porecha MM, Shah J. A pictorial essay - imaging in surgical jaundice. Indian J Radiol Imaging 2006. [DOI: 10.4103/0971-3026.29054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Affiliation(s)
- N A Patel
- Department of Radiodiagnosis, M.P.Shah Medical College, Jamnagar, Gujarat, India
| | - H Parekh
- Department of Radiodiagnosis, M.P.Shah Medical College, Jamnagar, Gujarat, India
| | - D P Vasavada
- Department of Radiodiagnosis, M.P.Shah Medical College, Jamnagar, Gujarat, India
| | - S G Mehta
- Department of Radiodiagnosis, M.P.Shah Medical College, Jamnagar, Gujarat, India
| | - M M Porecha
- Department of Radiodiagnosis, M.P.Shah Medical College, Jamnagar, Gujarat, India
| | - J Shah
- Department of Radiodiagnosis, M.P.Shah Medical College, Jamnagar, Gujarat, India
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26
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Piper GL, Patel NA, Patel JA, Malay MB, Julian TB. Neoadjuvant chemotherapy for locally advanced breast cancer results in alterations in preoperative tumor marker status. Am Surg 2004; 70:1103-6. [PMID: 15663054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
Neoadjuvant therapy followed by breast-conserving surgery has become an acceptable option for patients with locally advanced breast cancer. Although a distinct survival benefit has not been demonstrated using this approach, several questions have been raised following such therapy including its effects on receptor status and tumor markers. The current study retrospectively reviews estrogen receptor (ER), progesterone receptor (PR), and HER2-neu status in 55 consecutive patients treated by neoadjuvant chemotherapy. Preoperative and postoperative tumor markers were available for 43 of the 55 patients (78%). The pathologic complete tumor response rate (pCR) for this group was 19 per cent (8/43). Of those patients who did not achieve a pCR (n = 35), a change in tumor markers was seen in 25.7 per cent (9/35) of patients. When compared to a control group not undergoing neoadjuvant therapy, a significantly higher percent change in marker expression was noted in the neoadjuvant group (25.7% vs 5.9%, P = 0.046). ER, PR, and HER2-neu status remain important prognostic indicators for breast cancer. Tumor markers are useful in planning adjuvant therapy regimens. In this review, nearly 19 per cent of patients achieved a pCR. In patients not achieving a pCR, one in four patients had at least one change in tumor marker status. This study demonstrates the importance of establishing receptor and marker status prior to neoadjuvant therapy, as many patients will achieve a pCR and make tumor analysis impossible. Postoperative marker studies should be performed given the possibility of a change in status. The clinical relevance of this data will require further long-term follow-up. Until such data becomes available, caution should be considered when basing adjuvant therapy regimens on preoperative tumor marker studies alone.
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Affiliation(s)
- G L Piper
- Departments of Surgery, Allegheny General Hospital, Pittsburgh, Pennsylvania 15212, USA
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27
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Patel NA, Piper G, Patel JA, Malay MB, Julian TB. Accurate axillary nodal staging can be achieved after neoadjuvant therapy for locally advanced breast cancer. Am Surg 2004; 70:696-9; discussion 699-700. [PMID: 15328803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
Lymph node status remains the most important prognostic indicator for breast cancer. Recent reports have established that the accuracy of assessing lymph node status is proportional to the number of nodes dissected. The accuracy of axillary staging following neoadjuvant chemotherapy has been cited as a technical concern due to limited node retrieval. The current study attempts to evaluate the ability to perform sentinel node biopsy (SNB) and formal axillary node dissection (AND) following neoadjuvant chemotherapy and to compare these results with non-neoadjuvant patients. One hundred sixteen consecutive patients undergoing SNB with simultaneous AND were retrospectively reviewed. Forty-two of these patients were treated with neoadjuvant chemotherapy prior to AND. Overall success rate in performing SNB in the neoadjuvant group was 95 per cent, and no false negatives have been noted to date. The overall SNB success rate in the non-neoadjuvant group was also 95 per cent with a false negative rate of 3 per cent. After AND in each group, a mean of 21 nodes were retrieved in the neoadjuvant group and 17.9 nodes in the non-neoadjuvant group (P = 0.018). In the neoadjuvant group, there were 19 node positive patients (42%) and 21 patients (28%) in the non-neoadjuvant group (P = 0.16). The mean number of positive nodes per patient was also similar between the two groups (2.9 in the neoadjuvant group vs 1.67 in the non-neoadjuvant group, P = 0.10). Following neoadjuvant therapy, accurate evaluation of the axilla is feasible. In this study, the mean number of nodes is significantly different in favor of the neoadjuvant group, but there is no significant difference in the number of node positive patients identified or in the mean number of positive nodes identified per patient. SNB is technically feasible with accuracy similar to that seen in patients with no history of neoadjuvant therapy. Neoadjuvant chemotherapy extends the use of breast-conserving therapy without sacrificing the ability to accurately stage the axilla either by use of standard axillary dissection or SNB.
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Affiliation(s)
- N A Patel
- Department of Surgery, Allegheny General Hospital, Pittsburgh, Pennsylvania 15212, USA
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28
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Rogowska J, Patel NA, Fujimoto JG, Brezinski ME. Optical coherence tomographic elastography technique for measuring deformation and strain of atherosclerotic tissues. Heart 2004; 90:556-62. [PMID: 15084558 PMCID: PMC1768234 DOI: 10.1136/hrt.2003.016956] [Citation(s) in RCA: 178] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVES To evaluate optical coherence tomographic elastography as a method for assessing the elastic properties of atherosclerotic plaque and the parameters that influence interpretation. METHODS Phantoms and aorta were examined in vitro to quantify speckle modulation and measure the displacement and strain maps. A correlation method was used as a speckle tracking technique for measuring axial and lateral displacement vectors and calculation of strain maps. The influence of correlation kernel size on accuracy of the method was evaluated. RESULTS In terms of a percentage error between calculated and measured displacements, the best results for phantoms were obtained with a 41 x 41 kernel (1.88% error). For both phantom and aorta images, it was found that, with the increasing size of cross correlation kernel, the axial and lateral displacement maps are less noisy and the displacement vectors are more clearly defined. However, the large kernels tend to average out the differences in displacements of small particles in phantoms and decrease the ability of speckle tracking to make microstructural assessments. Therefore, it is important to select kernel size carefully, based on the image features. CONCLUSIONS Optical tomographic elastography can be used to assess the microstructural properties of atherosclerotic tissue at micrometre scale resolution, but preselected analysis criteria must be understood in a critical interpretation of the results.
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Affiliation(s)
- J Rogowska
- Orthopedics Department, Brigham and Women's Hospital/Harvard Medical School, 75 Francis Street, Boston, Massachusetts 02115, USA
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29
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Roberts MJ, Adams SB, Patel NA, Stamper DL, Westmore MS, Martin SD, Fujimoto JG, Brezinski ME. A new approach for assessing early osteoarthritis in the rat. Anal Bioanal Chem 2003; 377:1003-6. [PMID: 14564447 DOI: 10.1007/s00216-003-2225-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2003] [Revised: 08/01/2003] [Accepted: 08/13/2003] [Indexed: 10/26/2022]
Abstract
Several animal models have been developed to investigate osteoarthritis and potential disease-modifying therapeutics. However, early disease data from these models are limited by the resolution of current imaging modalities. In this in-vitro study, an optical coherence tomography (OCT) system with an axial resolution of 15 micro m was used to track sequential changes in osteoarthritic rat knees. Osteoarthritis was induced via transection of the medial collateral ligament and an artificial full thickness meniscal tear. Imaging occurred at one, two, and three weeks after surgery. OCT successfully detected early signs of osteoarthritic change, including alteration of the cartilage surface and disruption of the bone-cartilage interface. This study demonstrates that OCT, along with the induction of mechanical injury, provides an excellent model for monitoring the sequential changes of osteoarthritis.
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Affiliation(s)
- M J Roberts
- Orthopedics Research, Department of Orthopedic Surgery, Brigham and Women's Hospital and Harvard Medical School, 75 Francis St, Boston, MA, 02115, USA
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30
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Patel NA, Chalfant CE, Watson JE, Wyatt JR, Dean NM, Eichler DC, Cooper DR. Insulin regulates alternative splicing of protein kinase C beta II through a phosphatidylinositol 3-kinase-dependent pathway involving the nuclear serine/arginine-rich splicing factor, SRp40, in skeletal muscle cells. J Biol Chem 2001; 276:22648-54. [PMID: 11283022 DOI: 10.1074/jbc.m101260200] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Insulin regulates the inclusion of the exon encoding protein kinase C (PKC) betaII mRNA. In this report, we show that insulin regulates this exon inclusion (alternative splicing) via the phosphatidylinositol 3-kinase (PI 3-kinase) signaling pathway through the phosphorylation state of SRp40, a factor required for insulin-regulated splice site selection for PKCbetaII mRNA. By taking advantage of a well known inhibitor of PI 3-kinase, LY294002, we demonstrated that pretreatment of L6 myotubes with LY294002 blocked insulin-induced PKCbetaII exon inclusion as well as phosphorylation of SRp40. In the absence of LY294002, overexpression of SRp40 in L6 cells mimicked insulin-induced exon inclusion. When antisense oligonucleotides targeted to a putative SRp40-binding sequence in the betaII-betaI intron were transfected into L6 cells, insulin effects on splicing and glucose uptake were blocked. Taken together, these results demonstrate a role for SRp40 in insulin-mediated alternative splicing independent of changes in SRp40 concentration but dependent on serine phosphorylation of SRp40 via a PI 3-kinase signaling pathway. This switch in PKC isozyme expression is important for increases in the glucose transport effect of insulin. Significantly, insulin regulation of PKCbetaII exon inclusion occurred in the absence of cell growth and differentiation demonstrating that insulin-induced alternative splicing of PKCbetaII mRNA in L6 cells occurs in response to a metabolic change.
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Affiliation(s)
- N A Patel
- Department of Biochemistry and Molecular Biology, University of South Florida, Tampa, Florida 33612, USA
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31
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Patel NA, Patel JA, Stins MF, Kim KS, Chang SL. Dexamethasone affects cytokine-mediated adhesion of HL-60 human promyelocytic leukemia cells to cultured dermal microvascular endothelial cells. Clin Immunol 2001; 99:387-94. [PMID: 11358436 DOI: 10.1006/clim.2001.5029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Leukocyte endothelial adhesion (LEA) is the prelude to a complex cascade of reactions following an immunological challenge. Recently, LEA has been implicated in the molecular basis of several dermatological disorders. While the role of proinflammatory cytokines, such as interleukin-1 beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha), in LEA has been investigated using nondermal models, limited data exist regarding their effects on LEA in dermal models. This study shows that cotreatment of cultured human dermal endothelial cells (CADMEC) with IL-1beta and TNF-alpha resulted in a marked increase in the adherence of human promyelocytic leukemia (HL-60) cells to CADMEC and an increase in expression of intercellular adhesion molecule-1 and E-selectin. Pretreatment of CADMEC with dexamethasone, a long-lasting glucocorticoid, resulted in a decrease in both HL-60 cell adhesion to CADMEC and adhesion molecule expression. Taken together, these data demonstrate that LEA may play a role in inflammatory skin conditions and in the mechanisms underlying the potential use of glucocorticoids as a treatment option.
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Affiliation(s)
- N A Patel
- Department of Biology, Seton Hall University, South Orange, New Jersey 07079, USA
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32
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Torrelles JM, Patel NA, Gómez JF, Ho PT, Rodríguez LF, Anglada G, Garay G, Greenhill L, Curiel S, Cantó J. Spherical episodic ejection of material from a young star. Nature 2001; 411:277-80. [PMID: 11357123 DOI: 10.1038/35077020] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The exact processes by which interstellar matter condenses to form young stars are of great interest, in part because they bear on the formation of planets like our own from the material that fails to become part of the star. Theoretical models suggest that ejection of gas during early phases of stellar evolution is a key mechanism for removing excess angular momentum, thereby allowing material to drift inwards towards the star through an accretion disk. Such ejections also limit the mass that can be accumulated by the stellar core. To date, these ejections have been observed to be bipolar and highly collimated, in agreement with theory. Here we report observations at very high angular resolution of the proper motions of an arc of water-vapour masers near a very young, massive star in Cepheus. We find that the arc of masers can be fitted to a circle with an accuracy of one part in a thousand, and that the structure is expanding. Only a sphere will always produce a circle in projection, so our observations strongly suggest that the perfectly spherical ejection of material from this star took place about 33 years earlier. The spherical symmetry of the ejecta and its episodic nature are very surprising in the light of present theories.
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Affiliation(s)
- J M Torrelles
- Institut d'Estudis Espacials de Catalunya (IEEC/CSIC) and Instituto de Ciencias del Espacio (CSIC), Gran Capità 2, 08034 Barcelona, Spain
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Yamamoto M, Acevedo-Duncan M, Chalfant CE, Patel NA, Watson JE, Cooper DR. Acute glucose-induced downregulation of PKC-betaII accelerates cultured VSMC proliferation. Am J Physiol Cell Physiol 2000; 279:C587-95. [PMID: 10942708 DOI: 10.1152/ajpcell.2000.279.3.c587] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Accelerated vascular smooth muscle cell (VSMC) proliferation contributes to the formation of atherosclerotic lesions. To investigate protein kinase C (PKC)-betaII functions with regard to glucose-induced VSMC proliferation, human VSMC from aorta (AoSMC), a clonal VSMC line of rat aorta (A10), and A10 cells overexpressing PKC-betaI (betaI-A10) and PKC-betaII (betaII-A10) were studied with the use of three techniques to evaluate glucose effects on aspects affecting proliferation. High glucose (25 mM) increased DNA synthesis and accelerated cell proliferation compared with normal glucose (5.5 mM) in AoSMC and A10 cells, but not in betaI-A10 and betaII-A10 cells. The PKC-betaII specific inhibitor CGP-53353 inhibited glucose-induced cell proliferation and DNA synthesis in AoSMC and A10 cells. In flow cytometry analysis, high glucose increased the percentage of A10 cells at 12 h after cell cycle initiation but did not increase the percentage of betaI-A10 or betaII-A10 cells entering S phase. PKC-betaII protein levels decreased before the peak of DNA synthesis, and high glucose further decreased PKC-betaII mRNA and protein levels in AoSMC and A10 cells. These results suggest that high glucose downregulates endogenous PKC-betaII, which then alters the normal inhibitory role of PKC-betaII in cell cycle progression, resulting in the stimulation of VSMC proliferation through acceleration of the cell cycle.
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Affiliation(s)
- M Yamamoto
- Department of Biochemistry and Molecular Biology, University of South Florida, College of Medicine, Tampa, Florida 33612, USA
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Yamamoto M, Patel NA, Taggart J, Sridhar R, Cooper DR. A shift from normal to high glucose levels stimulates cell proliferation in drug sensitive MCF-7 human breast cancer cells but not in multidrug resistant MCF-7/ADR cells which overproduce PKC-betaII. Int J Cancer 1999; 83:98-106. [PMID: 10449615 DOI: 10.1002/(sici)1097-0215(19990924)83:1<98::aid-ijc18>3.0.co;2-v] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Glucose concentration may be an important factor in breast cancer cell proliferation because the prevalence of breast cancer is high in diabetic patients. To determine the role of protein kinase C (PKC)-betaII in regulating MCF-7 cell proliferation at different glucose concentrations, the effects of glucose and a PKC-betaII-specific inhibitor (CGP53353) were examined in cultures of MCF-7 human breast cancer cell line and its multidrug resistant variant (MCF-7/ADR). Cell proliferation and DNA synthesis of MCF-7 were increased when glucose concentration in the culture medium was increased from normal (5.5 mM) to high (25 mM) levels. However, MCF-7/ADR cell proliferation and DNA synthesis were unaffected by the increase in glucose. PKC-betaII protein and the corresponding mRNA levels were 4- to 5-fold higher in MCF-7/ADR than in MCF-7 cells. High glucose-induced decreases of PKC-betaII protein and mRNA levels were observed during the DNA synthesis phase in MCF-7 but not in MCF-7/ADR cells. Decreases in PKC-betaII mRNA and protein levels below a critical threshold in response to high glucose levels may account for glucose-stimulated proliferation of MCF-7 cells. Cultures of multidrug resistant MCF-7/ADR cells reach maximal cell density in medium containing normal (5.5 mM) glucose levels and are not induced to grow further in response to high (25 mM) glucose. Our results demonstrate a link between high glucose-induced PKC-betaII isozyme down-regulation with concomitant acceleration of cell cycle progression in MCF-7 cells.
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Affiliation(s)
- M Yamamoto
- Department of Biochemistry and Molecular Biology, University of South Florida College of Medicine, Tampa, FL, USA
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Patel NA, Chalfant CE, Yamamoto M, Watson JE, Eichler DC, Cooper DR. Acute hyperglycemia regulates transcription and posttranscriptional stability of PKCbetaII mRNA in vascular smooth muscle cells. FASEB J 1999; 13:103-13. [PMID: 9872935 DOI: 10.1096/fasebj.13.1.103] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Acute hyperglycemia may contribute to the progression of atherosclerosis by regulating protein kinase C (PKC) isozymes and by accelerating vascular smooth muscle cell (VSMC) proliferation. We investigated acute glucose regulation of PKCbeta gene expression in A10 cells, a rat aortic smooth muscle cell line. Western blot analysis showed that PKCbetaII protein levels decreased with high glucose (25 mM) compared to normal glucose (5.5 mM), whereas PKCbetaI levels were unaltered. PKCbeta mRNA levels were depleted by 60-75% in hyperglycemic conditions. To elucidate whether high glucose regulated PKCbeta expression via the common promoter for PKCbetaI and PKCbetaII, deletion constructs of the PKCbeta promoter ligated to CAT as reporter gene were transfected into A10 cells. Construct D (-411 to +179CAT) showed quenching in high glucose (25 mM) and suggested the involvement of a carbohydrate response element in the 5' promoter region of the PKCbeta gene. In actinomycin D-treated A10 cells, a 60% decrease in PKCbeta mRNA with high glucose treatment indicated that posttranscriptional destabilization by glucose was also occurring. We have demonstrated that glucose-induced posttranscriptional destabilization of PKCbetaII message is mediated via a nuclease activity present in the cytosol. The specificity of glucose to posttranscriptionally destabilize PKCbetaII mRNA, but not the PKCbetaI mRNA, was confirmed in both A10 cells and primary cultures from human aorta.
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Affiliation(s)
- N A Patel
- Departments of Biochemistry and Molecular Biology, College of Medicine, University of South Florida, Tampa, USA
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Abstract
The findings presented here clearly indicate an association between opioid- and cytokine-dependent systems. Exposure to exogenous opioids can produce profound effects on IL-1-mediated immune responses. Chronic exposure to morphine appears to disrupt the brain-immune axis by desensitizing the IL-1 activation of the HPA axis, and consequently potentiate the LEA response to IL-1. On the other hand, endogeneous IL-1, secreted in response to disease or stress, may alter the endogenous opioid pathway by inducing the expression of opioid receptors in endothelial cells. Clinically, the potential impact on the body's defense mechanisms resulting from the interaction between opioids, such as morphine, and cytokines, such as IL-1, can be substantial. Further investigation of this interaction is essential to understanding the extent of damage in human body caused by drugs of abuse, such as morphine.
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Affiliation(s)
- S L Chang
- Department of Biology, Seton Hall University, South Orange, New Jersey 07079, USA
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Abstract
It is thought that the physiological actions of endogenous cannabinoid arachidonylethanolamide (AEA), as well as exogenous cannabinoids such as Delta9-tetrahydrocannabinol (THC), are mediated by two subtypes of cannabinoid receptors, CB1 and CB2, which have recently been characterized. Injection of AEA leads to alterations in motor behavior and endocrine function. While these phenomena have been well characterized, the neuronal substrate of AEA's actions remains undetermined. In this study, FOS immunoreactivity (FOSir) was used to map rat brain nuclei that are responsive to a single intracerebroventricular injection of AEA. The results showed that FOSir was induced in several nuclei including the bed nucleus of the stria terminalis (BNST), paraventricular nucleus of the hypothalamus (PVN), central nucleus of the amygdala (Ce), periaqueductal gray area (PAG), dentate gyrus in the hippocampus (Dg), paraventricular nucleus of the thalamus (PVA), median preoptic nucleus (MnPO), periventricular nucleus (Pe), caudate putamen (CPU) and the ependymal lining of the ventricles. The pattern of activation identified correlates, in part, with the distribution of CB receptors. At the same time, a new subset of nuclei, without demonstrable CB receptors, have been shown to respond to an AEA challenge. Activation of these nuclei is consistent with the physiological effects of AEA. These findings provide valuable information on the response to AEA at the level of neuronal activation and provide the basis for a broader understanding of the possible role of CB receptors in the modulation of motor and endocrine function associated with the use of exogenous cannabinoids, such as marijuana.
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Affiliation(s)
- N A Patel
- Department of Biology, Seton Hall University, 400 South Orange Avenue, South Orange, NJ 07079, USA
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Yamamoto M, Acevedo-Duncan M, Chalfant CE, Patel NA, Watson JE, Cooper DR. The roles of protein kinase C beta I and beta II in vascular smooth muscle cell proliferation. Exp Cell Res 1998; 240:349-58. [PMID: 9597008 DOI: 10.1006/excr.1998.3999] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The role of protein kinase C (PKC) on proliferation of A10 vascular smooth muscle cells (VSMC) was studied by overexpressing specific PKC-beta I and -beta II isozymes. PKC-beta I and -beta II are derived from alternative splicing of the exon encoding the carboxy-terminal (C-terminal) 50 or 52 amino acids, respectively. The differential functions of the two isozymes with regard to cell proliferation, DNA synthesis, and the cell cycle were investigated in A10 cells, a clonal cell line of VSMC from rat aorta, and in A10 cells overexpressing PKC-beta I and PKC-beta II (beta I-A10 and beta II-A10). PKC levels were increased three- to fourfold in heterogeneous cultures of stably transfected cells. Although doubling time of A10 cells was 36 h, the cell doubling time in beta I-A10 cells decreased by 12 h, and, in contrast, the doubling time of beta II-A10 cells increased by 12 h compared to A10 cells. The increase of [3H]thymidine (TdR) incorporation was accelerated and increased in beta I-A10 cells, but slowed and diminished in beta II-A10 cells compared to A10 and control cells transfected with empty vector. Cell cycle analysis of beta I-A10 cells showed an acceleration of S phase entry while beta II-A10 cells slowed S phase entry. These results suggest that PKC-beta I and PKC-beta II regulate cell proliferation bidirectionally and that PKC-beta I and PKC-beta II may have distinct and opposing functions as cell cycle check point mediators during late G1 phase and may regulate S phase entry in A10 VSMC.
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Affiliation(s)
- M Yamamoto
- Department of Biochemistry and Molecular Biology, University of South Florida College of Medicine, Tampa, USA.
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Abstract
Immunocytokines, such as interleukin-1 (IL-1), have been shown to be involved in the activation and/or induction of a variety of transcription factors which may modulate the expression of genes possessing DNA binding sites on which these transcription factors act. The promoter DNA sequence of the mu opioid receptor gene contains IL-1 response elements such as NF-IL6, and, therefore, the receptor gene may be responsive to IL-1. To investigate the effect of IL-1 on the opioid receptor gene, the in vitro expression of mu opioid receptor mRNA in neural microvascular endothelial cells (NMVEC) was determined before and after IL-1 treatment. PCR analysis revealed that there was virtually no mu opioid receptor expression at basal levels and no increase after either IL-1alpha or IL-1beta treatment. However, simultaneous treatment with both IL-1alpha and IL-1beta increased mu opioid receptor expression. This upregulation of mu opioid receptor expression provides direct evidence of a relationship between opioid and cytokine actions, and suggests that opioid-dependent pathways may be modulated in the disease state.
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MESH Headings
- Cells, Cultured
- DNA Primers
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- Humans
- Interleukin-1/pharmacology
- Polymerase Chain Reaction
- Promoter Regions, Genetic/genetics
- RNA, Messenger/analysis
- Receptors, Opioid, mu/biosynthesis
- Receptors, Opioid, mu/genetics
- Tumor Cells, Cultured
- Up-Regulation/drug effects
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Affiliation(s)
- E L Vidal
- Department of Biology, Seton Hall University, South Orange, NJ 07079, USA
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Chang SL, Patel NA, Romero AA, Thompson J, Zadina JE. FOS expression induced by interleukin-1 or acute morphine treatment in the rat hypothalamus is attenuated by chronic exposure to morphine. Brain Res 1996; 736:227-36. [PMID: 8930328 DOI: 10.1016/0006-8993(96)00698-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Interleukin-1 (IL-1) is a cytokine involved in a variety of biological activities. It has been hypothesized that the immunomodulatory effects of IL-1 are the result of both direct action on immune cells and indirect action on a regulatory cascade mediated through the hypothalamus. Chronic exposure to substances of abuse, such as morphine, appears to modulate immunoresponsiveness by mechanisms not yet defined. The expression of FOS, the protein product of the c-fos proto-oncogene, has been widely used as an anatomical marker for monitoring neuronal activity. We have previously shown that acute treatment with either morphine or IL-1 induces FOS immunoreactivity in the rat brain, including the paraventricular (PVN) and supraoptic (SON) nuclei of the hypothalamus. In this study, using immunocytochemical staining of FOS, we demonstrate that chronic exposure to morphine attenuates the cellular responsiveness to IL-1 and to morphine in the PVN and SON, whereas pretreatment with naloxone, an opiate receptor antagonist, does not reverse the effect of IL-1 on FOS expression. The results not only confirm that the PVN and SON are neuroanatomical sites where the actions of both morphine and IL-1 converge, but also indicate that chronic exposure to morphine may desensitize the cellular response involved in hypothalamic functions through an IL-1-dependent pathway.
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Affiliation(s)
- S L Chang
- Department of Biology, Seton Hall University, South Orange, NJ 07079, USA.
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Abstract
The cytokine, interleukin-1 beta (IL-1 beta), can modulate both immune and neuroendocrine events. Alteration of IL-1 beta expression by exogenous factors, such as morphine, may affect the neuro-endocrine-immune axis. Brain sections from male rats implanted with either morphine or placebo pellets were stained for IL-1 beta immunoreactivity. The results showed pronounced attenuation of IL-1 beta immuno-reactivity in the dentate gyrus and the CA1-CA3 fields of the hippocampus in morphine-implanted rats compared to placebo controls. It has been suggested that the hippocampus is involved in the regulation of hypothalamic activity. Attenuation of IL-1 beta expression in the hippocampus by chronic exposure to morphine may be one of the mechanisms underlying the neuro-endocrine-immune modulatory effects of opiate addiction.
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Affiliation(s)
- N A Patel
- Department of Biology, Seton Hall University, South Orange, NJ 07079, USA
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Abstract
The expression of the Fos proto-oncogene protein has been used as an anatomical marker of activated brain areas. Detection of Fos immunoreactivity can provide information about the sites of action of various stimuli at the level of single cell resolution. Following intraperitoneal injection of ethanol (16% w/v), Fos immunoreactivity was induced in several rat brain areas including the bed nucleus of the stria terminalis, paraventricular hypothalamic nucleus, the central nucleus of amygdala, Edinger-Westphal nucleus, locus coeruleus nucleus and parabrachial nucleus. The induction was dose dependent, and the length of activation time was different in each nucleus. Fos immunoreactivity in the supraoptic nucleus appeared only when a higher concentration of ethanol was injected. Repeated administration of ethanol twice daily for 17 or 24 days resulted in a desensitization of Fos immunoreactivity in these nuclei. These data suggest that induction of Fos immunoreactivity can be used to determine the sites at which ethanol acts on the brain, and may provide important information about the mechanisms underlying the tolerance and physical dependence of alcohol usage.
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Affiliation(s)
- S L Chang
- Department of Biology, Seton Hall University, South Orange, NJ 07079, USA
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Abbas AM, Chandra V, Dongaonkar PP, Goel PK, Kacker P, Patel NA, Shrivastava OP, Thakkar B, Tillotson GS. Ciprofloxacin versus amoxycillin/clavulanic acid in the treatment of urinary tract infections in general practice. J Antimicrob Chemother 1989; 24:235-9. [PMID: 2793646 DOI: 10.1093/jac/24.2.235] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
An open, randomized general practice study was performed to assess the comparative efficacy and tolerability of ciprofloxacin and amoxycillin/clavulanic acid in the treatment of uncomplicated urinary tract infection. One hundred and eighty nine patients were recruited into the study. In comparison of pre- and post-treatment urine cultures and symptomatology, ciprofloxacin was significantly more effective (P less than 0.01) than amoxycillin/clavulanic acid. Both drugs were well tolerated with minimal adverse side effects. Ciprofloxacin is an effective and safe treatment for uncomplicated urinary tract infection in general practice.
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Affiliation(s)
- A M Abbas
- Microbiology Department, Rotherham District General Hospital, Newbury, UK
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Abbas AM, Chandra V, Dongaonkar PP, Goel PK, Kacker P, Patel NA, Shrivastava OP, Thakkar B, Tillotson GS. Ciprofloxacin versus amoxycillin/clavulanic acid in the treatment of urinary tract infections in general practice. J Chemother 1989; 1:858-9. [PMID: 16312672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Affiliation(s)
- A M Abbas
- Rotherham District General Hospital, Moorgate Rd., Rotherham S60 2UD, UK
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Patel NA. "Photoadaptor for ocular photography" a new design. Indian J Ophthalmol 1984; 32:317-9. [PMID: 6545313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023] Open
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Patel JN, Nanavati KJ, Parekh AM, Karnani J, Patel G, Solanki PV, Patel NA, Shah BC. Cavernoma of liver. J Assoc Physicians India 1982; 30:165. [PMID: 7169427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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