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Yong J, Parekh VS, Reilly SM, Nayak J, Chen Z, Lebeaupin C, Jang I, Zhang J, Prakash TP, Sun H, Murray S, Guo S, Ayala JE, Satin LS, Saltiel AR, Kaufman RJ. Chop/ Ddit3 depletion in β cells alleviates ER stress and corrects hepatic steatosis in mice. Sci Transl Med 2021; 13:13/604/eaba9796. [PMID: 34321322 DOI: 10.1126/scitranslmed.aba9796] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 04/07/2021] [Accepted: 06/23/2021] [Indexed: 12/21/2022]
Abstract
Type 2 diabetes (T2D) is a metabolic disorder characterized by hyperglycemia, hyperinsulinemia, and insulin resistance (IR). During the early phase of T2D, insulin synthesis and secretion by pancreatic β cells is enhanced, which can lead to proinsulin misfolding that aggravates endoplasmic reticulum (ER) protein homeostasis in β cells. Moreover, increased circulating insulin may contribute to fatty liver disease. Medical interventions aimed at alleviating ER stress in β cells while maintaining optimal insulin secretion are therefore an attractive therapeutic strategy for T2D. Previously, we demonstrated that germline Chop gene deletion preserved β cells in high-fat diet (HFD)-fed mice and in leptin receptor-deficient db/db mice. In the current study, we further investigated whether targeting Chop/Ddit3 specifically in murine β cells conferred therapeutic benefits. First, we showed that Chop deletion in β cells alleviated β cell ER stress and delayed glucose-stimulated insulin secretion (GSIS) in HFD-fed mice. Second, β cell-specific Chop deletion prevented liver steatosis and hepatomegaly in aged HFD-fed mice without affecting basal glucose homeostasis. Third, we provide mechanistic evidence that Chop depletion reduces ER Ca2+ buffering capacity and modulates glucose-induced islet Ca2+ oscillations, leading to transcriptional changes of ER chaperone profile ("ER remodeling"). Last, we demonstrated that a GLP1-conjugated Chop antisense oligonucleotide strategy recapitulated the reduction in liver triglycerides and pancreatic insulin content. In summary, our results demonstrate that Chop depletion in β cells provides a therapeutic strategy to alleviate dysregulated insulin secretion and consequent fatty liver disease in T2D.
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Affiliation(s)
- Jing Yong
- Division of Metabolism and Endocrinology, Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA. .,Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92037, USA
| | - Vishal S Parekh
- Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92037, USA.,Department of Pharmacology, University of Michigan Medical School, 1000 Wall St., Ann Arbor, MI 48105, USA
| | - Shannon M Reilly
- Department of Pharmacology, University of Michigan Medical School, 1000 Wall St., Ann Arbor, MI 48105, USA.,Division of Metabolism and Endocrinology, Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Jonamani Nayak
- Division of Metabolism and Endocrinology, Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA.,Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92037, USA
| | - Zhouji Chen
- Division of Metabolism and Endocrinology, Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA.,Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92037, USA
| | - Cynthia Lebeaupin
- Division of Metabolism and Endocrinology, Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA.,Department of Pharmacology, University of Michigan Medical School, 1000 Wall St., Ann Arbor, MI 48105, USA.,Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92037, USA.,Division of Metabolism and Endocrinology, Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Insook Jang
- Division of Metabolism and Endocrinology, Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA.,Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92037, USA
| | - Jiangwei Zhang
- Cardiometabolic Phenotyping Core, Sanford-Burnham Medical Research Institute, 6400 Sanger Road, Orlando, FL 32827, USA.,Department of Antisense Drug Discovery, Ionis Pharmaceuticals Inc., 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Thazha P Prakash
- Cardiometabolic Phenotyping Core, Sanford-Burnham Medical Research Institute, 6400 Sanger Road, Orlando, FL 32827, USA.,Department of Antisense Drug Discovery, Ionis Pharmaceuticals Inc., 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Hong Sun
- Cardiometabolic Phenotyping Core, Sanford-Burnham Medical Research Institute, 6400 Sanger Road, Orlando, FL 32827, USA.,Department of Antisense Drug Discovery, Ionis Pharmaceuticals Inc., 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Sue Murray
- Cardiometabolic Phenotyping Core, Sanford-Burnham Medical Research Institute, 6400 Sanger Road, Orlando, FL 32827, USA.,Department of Antisense Drug Discovery, Ionis Pharmaceuticals Inc., 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Shuling Guo
- Cardiometabolic Phenotyping Core, Sanford-Burnham Medical Research Institute, 6400 Sanger Road, Orlando, FL 32827, USA.,Department of Antisense Drug Discovery, Ionis Pharmaceuticals Inc., 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Julio E Ayala
- Department of Molecular Physiology & Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.,Cardiometabolic Phenotyping Core, Sanford-Burnham Medical Research Institute, 6400 Sanger Road, Orlando, FL 32827, USA.,Department of Molecular Physiology & Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Leslie S Satin
- Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92037, USA.,Department of Pharmacology, University of Michigan Medical School, 1000 Wall St., Ann Arbor, MI 48105, USA
| | - Alan R Saltiel
- Department of Pharmacology, University of Michigan Medical School, 1000 Wall St., Ann Arbor, MI 48105, USA.,Division of Metabolism and Endocrinology, Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA.,Department of Pharmacology, University of California San Diego, La Jolla, CA 92093, USA
| | - Randal J Kaufman
- Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92037, USA.
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Sharma V, Smolin J, Nayak J, Ayala JE, Scott DA, Peterson SN, Freeze HH. Mannose Alters Gut Microbiome, Prevents Diet-Induced Obesity, and Improves Host Metabolism. Cell Rep 2019; 24:3087-3098. [PMID: 30231992 DOI: 10.1016/j.celrep.2018.08.064] [Citation(s) in RCA: 98] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 06/18/2018] [Accepted: 08/22/2018] [Indexed: 12/23/2022] Open
Abstract
Mannose is an important monosaccharide for protein glycosylation in mammals but is an inefficient cellular energy source. Using a C57BL6/J mouse model of diet-induced obesity, we show that mannose supplementation of high-fat-diet-fed mice prevents weight gain, lowers adiposity, reduces liver steatosis, increases endurance and maximal O2 consumption, and improves glucose tolerance. Mannose-supplemented mice have higher fecal energy content, suggesting reduced caloric absorption by the host. Mannose increases the Bacteroidetes to Firmicutes ratio in the gut microbiota, a signature associated with the lean phenotype. These beneficial effects of mannose are observed when supplementation is started early in life. Functional transcriptomic analysis of cecal microbiota revealed profound and coherent changes in microbial energy metabolism induced by mannose that are predicted to lead to reduced energy harvest from complex carbohydrates by gut microbiota. Our results suggest that the gut microbiota contributes to mannose-induced resistance to deleterious effects of a high-fat diet. VIDEO ABSTRACT.
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Affiliation(s)
- Vandana Sharma
- Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA 92037, USA.
| | - Jamie Smolin
- Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Jonamani Nayak
- Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Julio E Ayala
- Sanford-Burnham-Prebys Medical Discovery Institute, Orlando, FL 32827, USA
| | - David A Scott
- Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Scott N Peterson
- Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Hudson H Freeze
- Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
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Singh S, D'Souza SW, Nayak J, Suard E, Chapon L, Senyshyn A, Petricek V, Skourski Y, Nicklas M, Felser C, Chadov S. Room-temperature tetragonal non-collinear Heusler antiferromagnet Pt2MnGa. Nat Commun 2016; 7:12671. [PMID: 27561795 PMCID: PMC5007462 DOI: 10.1038/ncomms12671] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 07/21/2016] [Indexed: 12/04/2022] Open
Abstract
Antiferromagnetic spintronics is a rapidly growing field, which actively introduces new principles of magnetic storage. Despite that, most applications have been suggested for collinear antiferromagnets. In this study, we consider an alternative mechanism based on long-range helical order, which allows for direct manipulation of the helicity vector. As the helicity of long-range homogeneous spirals is typically fixed by the Dzyaloshinskii-Moriya interactions, bi-stable spirals (left- and right-handed) are rare. Here, we report a non-collinear room-temperature antiferromagnet in the tetragonal Heusler group. Neutron diffraction reveals a long-period helix propagating along its tetragonal axis. Ab-initio analysis suggests its pure exchange origin and explains its helical character resulting from a large basal plane magnetocrystalline anisotropy. The actual energy barrier between the left- and right-handed spirals is relatively small and might be easily overcome by magnetic pulse, suggesting Pt2MnGa as a potential candidate for non-volatile magnetic memory.
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Affiliation(s)
- Sanjay Singh
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, Dresden D-01187, Germany
| | - S. W. D'Souza
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, Dresden D-01187, Germany
| | - J. Nayak
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, Dresden D-01187, Germany
| | - E. Suard
- Institut Laue-Langevin, BP 156, Grenoble Cedex 9 38042, France
| | - L. Chapon
- Institut Laue-Langevin, BP 156, Grenoble Cedex 9 38042, France
| | - A. Senyshyn
- Forschungsneutronenquelle Heinz Maier-Leibnitz FRM-II, Technische Universität München, Lichtenbergstrasse 1, Garching 85747, Germany
| | - V. Petricek
- Department of Structure Analysis, Institute of Physics ASCR, Na Slovance 2, Praha 18221, Czech Republic
| | - Y. Skourski
- Dresden High Magnetic Field Laboratory (HLD-EMFL), Helmholtz-Zentrum Dresden-Rossendorf, Dresden D-01328, Germany
| | - M. Nicklas
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, Dresden D-01187, Germany
| | - C. Felser
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, Dresden D-01187, Germany
| | - S. Chadov
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, Dresden D-01187, Germany
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4
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Santosh T, Patro M, Nayak J, Behera B. A classical case of Peutz–Jeghers syndrome with brief review of literature. Human Pathology: Case Reports 2016. [DOI: 10.1016/j.ehpc.2015.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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5
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Nizamuddin S, Govindaraj P, Saxena S, Kashyap M, Mishra A, Singh S, Rotti H, Raval R, Nayak J, Bhat BK, Prasanna BV, Dhumal VR, Bhale S, Joshi KS, Dedge AP, Bharadwaj R, Gangadharan GG, Nair S, Gopinath PM, Patwardhan B, Kondaiah P, Satyamoorthy K, Valiathan MS, Thangaraj K. Reply to 'Lack of replication of association of THSD7A with obesity'. Int J Obes (Lond) 2016; 40:727-8. [PMID: 26902698 DOI: 10.1038/ijo.2016.16] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- S Nizamuddin
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | - P Govindaraj
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | - S Saxena
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | - M Kashyap
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | - A Mishra
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | - S Singh
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | - H Rotti
- School of Life Sciences, Manipal University, Manipal, India
| | - R Raval
- School of Life Sciences, Manipal University, Manipal, India
| | - J Nayak
- Shri Dharmasthala Manjunatheshwara College of Ayurveda, Udupi, India
| | - B K Bhat
- Shri Dharmasthala Manjunatheshwara College of Ayurveda, Udupi, India
| | - B V Prasanna
- Shri Dharmasthala Manjunatheshwara College of Ayurveda, Udupi, India
| | - V R Dhumal
- Sinhgad College of Engineering, Pune, India
| | - S Bhale
- Sinhgad College of Engineering, Pune, India
| | - K S Joshi
- Sinhgad College of Engineering, Pune, India
| | - A P Dedge
- Sinhgad College of Engineering, Pune, India
| | - R Bharadwaj
- Foundation for Revitalization of Local Health Traditions, Bengaluru, India
| | - G G Gangadharan
- Foundation for Revitalization of Local Health Traditions, Bengaluru, India
| | - S Nair
- Department of Statistics, Manipal University, Manipal, India
| | - P M Gopinath
- School of Life Sciences, Manipal University, Manipal, India
| | - B Patwardhan
- Interdisciplinary School of Health Sciences, University of Pune, Pune, India
| | - P Kondaiah
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India
| | - K Satyamoorthy
- School of Life Sciences, Manipal University, Manipal, India
| | - M S Valiathan
- School of Life Sciences, Manipal University, Manipal, India
| | - K Thangaraj
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
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Pattnaik SK, Ray B, Nayak J, Prusty A, Sinha S. Code blue protocol: observation and analysis of results over last 3 years in a new tertiary care hospital. Intensive Care Med Exp 2015. [PMCID: PMC4798034 DOI: 10.1186/2197-425x-3-s1-a205] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Pattnaik SK, Nayak J, Choudhary S, Pati JP. ENDOTRACHEAL INTUBATION IN INTENSIVE CARE UNIT: A PROSPECTIVE STUDY OF CLINICAL PRACTICE AND ADVERSE EVENTS. Intensive Care Med Exp 2015. [PMCID: PMC4798110 DOI: 10.1186/2197-425x-3-s1-a940] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023] Open
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8
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Mahadik M, Shinde S, Mohite V, Kumbhar S, Moholkar A, Rajpure K, Ganesan V, Nayak J, Barman S, Bhosale C. Visible light catalysis of rhodamine B using nanostructured Fe2O3, TiO2 and TiO2/Fe2O3 thin films. Journal of Photochemistry and Photobiology B: Biology 2014; 133:90-8. [DOI: 10.1016/j.jphotobiol.2014.01.017] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2013] [Revised: 12/26/2013] [Accepted: 01/28/2014] [Indexed: 11/15/2022]
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Sharma V, Nayak J, DeRossi C, Charbono A, Ichikawa M, Ng BG, Grajales-Esquivel E, Srivastava A, Wang L, He P, Scott DA, Russell J, Contreras E, Guess CM, Krajewski S, Del Rio-Tsonis K, Freeze HH. Mannose supplements induce embryonic lethality and blindness in phosphomannose isomerase hypomorphic mice. FASEB J 2014; 28:1854-69. [PMID: 24421398 DOI: 10.1096/fj.13-245514] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Patients with congenital disorder of glycosylation (CDG), type Ib (MPI-CDG or CDG-Ib) have mutations in phosphomannose isomerase (MPI) that impair glycosylation and lead to stunted growth, liver dysfunction, coagulopathy, hypoglycemia, and intestinal abnormalities. Mannose supplements correct hypoglycosylation and most symptoms by providing mannose-6-P (Man-6-P) via hexokinase. We generated viable Mpi hypomorphic mice with residual enzymatic activity comparable to that of patients, but surprisingly, these mice appeared completely normal except for modest (~15%) embryonic lethality. To overcome this lethality, pregnant dams were provided 1-2% mannose in their drinking water. However, mannose further reduced litter size and survival to weaning by 40 and 66%, respectively. Moreover, ~50% of survivors developed eye defects beginning around midgestation. Mannose started at birth also led to eye defects but had no effect when started after eye development was complete. Man-6-P and related metabolites accumulated in the affected adult eye and in developing embryos and placentas. Our results demonstrate that disturbing mannose metabolic flux in mice, especially during embryonic development, induces a highly specific, unanticipated pathological state. It is unknown whether mannose is harmful to human fetuses during gestation; however, mothers who are at risk for having MPI-CDG children and who consume mannose during pregnancy hoping to benefit an affected fetus in utero should be cautious.
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Affiliation(s)
- Vandana Sharma
- 2Sanford-Burnham Medical Research Institute (SBMRI), 10901 North Torrey Pines Road, La Jolla, CA 92037, USA.
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Singh S, Nayak J, Rai A, Rajput P, Hill AH, Barman SR, Pandey D. (3 + 1)D superspace description of the incommensurate modulation in the premartensite phase of Ni2MnGa: a high resolution synchrotron x-ray powder diffraction study. J Phys Condens Matter 2013; 25:212203. [PMID: 23656722 DOI: 10.1088/0953-8984/25/21/212203] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Le Bail and Rietveld analysis of high resolution synchrotron x-ray powder diffraction (SXRPD) data shows unambiguous signatures of the failure of the commensurate 3M modulation model. Using (3 + 1) dimensional superspace group formalism, we have not only confirmed the incommensurate modulation in the premartensite phase with a modulation wavevector of q = 0.337 61(5)c* but also determined the superspace group (Immm(00γ)s00), atomic positions and amplitude of modulations for the incommensurate premartensite phase of Ni2MnGa for the first time. Our results may have important implications in the understanding of the martensitic transition and hence the magnetic field induced strains.
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Affiliation(s)
- Sanjay Singh
- UGC-DAE Consortium for Scientific Research, Indore, India
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Virpari P, Nayak J, Brahmbhatt M, Thaker H. Study on isolation, molecular detection of virulence gene and antibiotic sensitivity pattern of Escherichia coli isolated from milk and milk products. Vet World 2013. [DOI: 10.5455/vetworld.2013.541-545] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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Thaker H, Brahmbhatt M, Nayak J. Isolation and identification of Staphylococcus aureus from milk and milk products and their drug resistance patterns in Anand, Gujarat. Vet World 2013. [DOI: 10.5455/vetworld.2013.10-13] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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13
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Nayak J, Maniraj M, Rai A, Singh S, Rajput P, Gloskovskii A, Zegenhagen J, Schlagel DL, Lograsso TA, Horn K, Barman SR. Bulk electronic structure of quasicrystals. Phys Rev Lett 2012; 109:216403. [PMID: 23215602 DOI: 10.1103/physrevlett.109.216403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Revised: 09/26/2012] [Indexed: 06/01/2023]
Abstract
We use hard x-ray photoemission to resolve a controversial issue regarding the mechanism for the formation of quasicrystalline solids, i.e., the existence of a pseudogap at the Fermi level. Our data from icosahedral fivefold Al-Pd-Mn and Al-Cu-Fe quasicrystals demonstrate the presence of a pseudogap, which is not observed in surface sensitive low energy photoemission because the spectrum is affected by a metallic phase near the surface. In contrast to Al-Pd-Mn, we find that in Al-Cu-Fe the pseudogap is fully formed; i.e., the density of states reaches zero at E(F) indicating that it is close to the metal-insulator phase boundary.
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Affiliation(s)
- J Nayak
- UGC-DAE Consortium for Scientific Research, Khandwa Road, Indore 452001, India
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Nayak J, Prabakar K, Park J, Kim H. Effect of synthesis temperature on structure, optical and photovoltaic properties of TiO2 nanorod thin films. Electrochim Acta 2012. [DOI: 10.1016/j.electacta.2012.01.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Thaker H, Brahmbhatt M, Nayak J. Study on occurrence and antibiogram pattern of Escherichia coli from raw milk samples in Anand, Gujarat, India. Vet World 2012. [DOI: 10.5455/vetworld.2012.556-559] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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16
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Maniraj M, D'Souza SW, Nayak J, Rai A, Singh S, Sekhar BNR, Barman SR. High energy resolution bandpass photon detector for inverse photoemission spectroscopy. Rev Sci Instrum 2011; 82:093901. [PMID: 21974594 DOI: 10.1063/1.3630948] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We report a bandpass ultraviolet photon detector for inverse photoemission spectroscopy with energy resolution of 82 ± 2 meV. The detector (Sr(0.7)Ca(0.3)F(2)/acetone) consists of Sr(0.7)Ca(0.3)F(2) entrance window with energy transmission cutoff of 9.85 eV and acetone as detection gas with 9.7 eV photoionization threshold. The response function of the detector, measured using synchrotron radiation, has a nearly Gaussian shape. The n = 1 image potential state of Cu(100) and the Fermi edge of silver have been measured to demonstrate the improvement in resolution compared to the CaF(2)/acetone detector. To show the advantage of improved resolution of the Sr(0.7)Ca(0.3)F(2)/acetone detector, the metal to semiconductor transition in Sn has been studied. The pseudogap in the semiconducting phase of Sn could be identified, which is not possible with the CaF(2)/acetone detector because of its worse resolution.
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Affiliation(s)
- M Maniraj
- UGC-DAE Consortium for Scientific Research, Khandwa Road, Indore, 452001, Madhya Pradesh, India
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Rabindra Singh K, Hikmat N, Smyth A, Nayak J. Surgical repair of submucous cleft palate: speech outcome at 1year. Br J Oral Maxillofac Surg 2011. [DOI: 10.1016/j.bjoms.2011.04.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Srikrishna G, Nayak J, Weigle B, Temme A, Foell D, Hazelwood L, Olsson A, Volkmann N, Hanein D, Freeze HH. Erratum: Carboxylated N-glycans on RAGE promote S100A12 binding and signaling, in Journal of Cellular Biochemistry, by Srikrishna et al. J Cell Biochem 2010. [DOI: 10.1002/jcb.22746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Srikrishna G, Nayak J, Weigle B, Temme A, Foell D, Hazelwood L, Olsson A, Volkmann N, Hanein D, Freeze HH. Carboxylated N-glycans on RAGE promote S100A12 binding and signaling. J Cell Biochem 2010; 110:645-59. [PMID: 20512925 DOI: 10.1002/jcb.22575] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The receptor for advanced glycation end products (RAGE) is a signaling receptor protein of the immunoglobulin superfamily implicated in multiple pathologies. It binds a diverse repertoire of ligands, but the structural basis for the interaction of different ligands is not well understood. We earlier showed that carboxylated glycans on the V-domain of RAGE promote the binding of HMGB1 and S100A8/A9. Here we study the role of these glycans on the binding and intracellular signaling mediated by another RAGE ligand, S100A12. S100A12 binds carboxylated glycans, and a subpopulation of RAGE enriched for carboxylated glycans shows more than 10-fold higher binding potential for S100A12 than total RAGE. When expressed in mammalian cells, RAGE is modified by complex glycans predominantly at the first glycosylation site (N25IT) that retains S100A12 binding. Glycosylation of RAGE and maximum binding sites for S100A12 on RAGE are also cell type dependent. Carboxylated glycan-enriched population of RAGE forms higher order multimeric complexes with S100A12, and this ability to multimerize is reduced upon deglycosylation or by using non-glycosylated sRAGE expressed in E. coli. mAbGB3.1, an antibody against carboxylated glycans, blocks S100A12-mediated NF-kappaB signaling in HeLa cells expressing full-length RAGE. These results demonstrate that carboxylated N-glycans on RAGE enhance binding potential and promote receptor clustering and subsequent signaling events following oligomeric S100A12 binding.
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Affiliation(s)
- Geetha Srikrishna
- Sanford Children's Health Research Center, Sanford-Burnham Medical Research Institute, La Jolla, California 92037, USA.
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Dhaka RS, Shukla AK, Maniraj M, D'Souza SW, Nayak J, Barman SR. An ultrahigh vacuum compatible sample holder for studying complex metal surfaces. Rev Sci Instrum 2010; 81:043907. [PMID: 20441350 DOI: 10.1063/1.3367302] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We present a design of a compact and versatile sample holder meant for studying complex (ternary) metallic crystals that require sputtering and annealing to high temperatures under ultrahigh vacuum (10(-10) mbar range) for obtaining the clean, ordered and stoichiometric surface. A resistive heater is fixed to the sample holder and not to the sample plate, and thus can be thoroughly degassed initially to high temperatures without heating the sample. The heater, which is mounted vertically on the sample holder frame, slides into the sample plate of rectangular cross-section during sample transfer. For efficient cooling that is required for adlayer deposition, Cu braids can be pressed on the sample plate from both sides through a screw mechanism. The sample holder has 5 degrees of freedom including a tilt rotation. The sample holder has been used to study different metal surfaces such as ferromagnetic shape memory alloys, alkali metal and Mn adlayers on Al-Pd-Mn quasicrystal, aluminum metal, and Al-Mn alloys. Here, our recent results on temperature dependent low energy electron diffraction study of Ni(2)MnGa(100) are presented.
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Affiliation(s)
- R S Dhaka
- UGC-DAE Consortium for Scientific Research, Khandwa Road, Indore, 452001 Madhya Pradesh, India
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Turovskaya O, Foell D, Sinha P, Vogl T, Newlin R, Nayak J, Nguyen M, Olsson A, Nawroth PP, Bierhaus A, Varki N, Kronenberg M, Freeze HH, Srikrishna G. RAGE, carboxylated glycans and S100A8/A9 play essential roles in colitis-associated carcinogenesis. Carcinogenesis 2008; 29:2035-43. [PMID: 18689872 PMCID: PMC2556970 DOI: 10.1093/carcin/bgn188] [Citation(s) in RCA: 228] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Patients with inflammatory bowel diseases are at increased risk for colorectal cancer, but the molecular mechanisms linking inflammation and cancer are not well defined. We earlier showed that carboxylated N-glycans expressed on receptor for advanced glycation end products (RAGE) and other glycoproteins mediate colitis through activation of nuclear factor kappa B (NF-κB). Because NF-κB signaling plays a critical role in the molecular pathogenesis of colitis-associated cancer (CAC), we reasoned that carboxylated glycans, RAGE and its ligands might promote CAC. Carboxylated glycans are expressed on a subpopulation of RAGE on colon cancer cells and mediate S100A8/A9 binding to RAGE. Colon tumor cells express binding sites for S100A8/A9 and binding leads to activation of NF-κB and tumor cell proliferation. Binding, downstream signaling and tumor cell proliferation are blocked by mAbGB3.1, an anti-carboxylate glycan antibody, and by anti-RAGE. In human colon tumor tissues and in a mouse model of CAC, we found that myeloid progenitors expressing S100A8 and S100A9 infiltrate regions of dysplasia and adenoma. mAbGB3.1 administration markedly reduces chronic inflammation and tumorigenesis in the mouse model of CAC and RAGE-deficient mice are resistant to the onset of CAC. These findings show that RAGE, carboxylated glycans and S100A8/A9 play essential roles in tumor–stromal interactions, leading to inflammation-associated colon carcinogenesis.
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Affiliation(s)
- Olga Turovskaya
- Division of Developmental Immunology, La Jolla Institute for Allergy and Immunology, La Jolla, CA, USA
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Nayak J, Bose R. Making sense, talking sexuality: India reaches out to its youth. SIECUS Rep 1997; 25:19-21. [PMID: 12347729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
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Abstract
Cranial nerve VII (facial) motorneurons begin extending axons through rhombomeres 4 and 5 (R4 and R5) in the chick hindbrain on the second day of incubation. Without crossing the midline, facial motorneuron axons extend laterally from a ventromedial cell body location. All facial motorneuron axons leave the hindbrain through a discrete exit site in R4. To examine the importance of the exit site in R4 on motorneuron pathfinding, we ablated R4 before motorneuron axonogenesis. We find that mechanisms intrinsic to R5 direct the initial lateral orientation of R5 motorneuron axons. Upon reaching a particular lateral position, all R5 motorneuron axons must turn. In normal embryos the axons all turn rostrally to reach the nerve exit in R4. In embryos with R4 ablated, sometimes the axons turn rostrally and sometimes they turn caudally. A model combining permissive fields and chemotropic cues is presented to account for our observations.
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Affiliation(s)
- S Chang
- Department of Anatomy, University of Pennsylvania School of Medicine, Philadelphia 19104
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Nayak J. Acquired haemophilia A. J Assoc Physicians India 1990; 38:891-3. [PMID: 2128937] [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: 12/30/2022]
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Das KC, Nayak J, Mohanty D, Garewal G. Comments to the paper by Rani et al. Chronic myelogenous leukaemia in infancy and childhood. Acta Haematol 1983; 69:212. [PMID: 6404108 DOI: 10.1159/000206892] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Das KC, Nayak J, Mohanty D, Garewal G. Cytology and cytogenetics in chronic myelogenous leukaemias. Indian J Med Res 1978; 68:148-63. [PMID: 279492] [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: 12/14/2022] Open
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