1
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Peng J, Li H, Tong F, Hu J, Li M, Chen G, Liu D, Liu J, Wang R, Xu H, Li X, Zhong X, Yao J, Cao B. Methylation changes of liver DNA during the formation of gallstones. Epigenomics 2024; 16:529-547. [PMID: 38444389 PMCID: PMC11160444 DOI: 10.2217/epi-2023-0391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 02/20/2024] [Indexed: 03/07/2024] Open
Abstract
Aim: To explore the overall methylation changes in liver tissues during the formation of gallstones, as well as the key pathways and genes involved in the process. Methods: Reduced-representation bisulfite sequencing and RNA sequencing were conducted on the liver tissues of mice with gallstones and control normal mice. Results: A total of 8705 differentially methylated regions in CpG and 1410 differentially expressed genes were identified. The joint analysis indicated that aberrant DNA methylation may be associated with dysregulated gene expression in key pathways such as cholesterol metabolism and bile secretion. Conclusion: We propose for the first time that methylation changes in some key pathway genes in liver tissue may be involved in the formation of gallstones.
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Affiliation(s)
- Junbin Peng
- Medical School of Anhui University Of Science & Technology, Huainan, 232001, Anhui, China
| | - Haojie Li
- Medical School of Anhui University Of Science & Technology, Huainan, 232001, Anhui, China
| | - Fang Tong
- Medical School of Anhui University Of Science & Technology, Huainan, 232001, Anhui, China
| | - Jinlong Hu
- Department of General Surgery, Anhui No.2 Provincial People’s Hospital, Hefei, 230041, Anhui, China
- Anhui Province Key Laboratory of Occupational Health, Anhui No.2 Provincial People’s Hospital, Hefei, 230041, China
| | - Min Li
- Department of General Surgery, Anhui No.2 Provincial People’s Hospital, Hefei, 230041, Anhui, China
| | - Gan Chen
- Department of General Surgery, Anhui No.2 Provincial People’s Hospital, Hefei, 230041, Anhui, China
| | - Dongquan Liu
- Department of General Surgery, Anhui No.2 Provincial People’s Hospital, Hefei, 230041, Anhui, China
| | - Jinshan Liu
- Anhui Medical University, Hefei, 230032, Anhui, China
| | - Rui Wang
- Bengbu Medical College, Bengbu, 233030, Anhui, China
| | - Hongyu Xu
- Anhui Medical University, Hefei, 230032, Anhui, China
| | - Xuanxuan Li
- Bengbu Medical College, Bengbu, 233030, Anhui, China
| | - Xinguo Zhong
- Department of General Surgery, Anhui No.2 Provincial People’s Hospital, Hefei, 230041, Anhui, China
| | - Jiaming Yao
- Department of General Surgery, Anhui No.2 Provincial People’s Hospital, Hefei, 230041, Anhui, China
| | - Baoqiang Cao
- Medical School of Anhui University Of Science & Technology, Huainan, 232001, Anhui, China
- Department of General Surgery, Anhui No.2 Provincial People’s Hospital, Hefei, 230041, Anhui, China
- Anhui Province Key Laboratory of Occupational Health, Anhui No.2 Provincial People’s Hospital, Hefei, 230041, China
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2
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Addadi L, Varsano N, Ben Moshe A. On the Helical Crystals of Cholesterol Monohydrate. Helv Chim Acta 2023. [DOI: 10.1002/hlca.202200173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/05/2023]
Affiliation(s)
- Lia Addadi
- Department of Chemical and Structural Biology Weizmann Institute of Science 7610001 Rehovot Israel
| | - Neta Varsano
- Department of Chemical Research Support Weizmann Institute of Science 7610001 Rehovot Israel
| | - Assaf Ben Moshe
- Department of Chemistry Bar Ilan University 5290002 Ramat Gan Israel
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3
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Nidorf SM. Insights into the evolving nature of atherosclerosis from surveillance of the aortic landscape in-vivo. Atherosclerosis 2022; 352:85-87. [DOI: 10.1016/j.atherosclerosis.2022.05.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 04/28/2022] [Accepted: 05/24/2022] [Indexed: 11/02/2022]
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4
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Shepelenko M, Hirsch A, Varsano N, Beghi F, Addadi L, Kronik L, Leiserowitz L. Polymorphism, Structure, and Nucleation of Cholesterol·H 2O at Aqueous Interfaces and in Pathological Media: Revisited from a Computational Perspective. J Am Chem Soc 2022; 144:5304-5314. [PMID: 35293741 PMCID: PMC8972249 DOI: 10.1021/jacs.1c10563] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
We
revisit the important issues of polymorphism, structure, and
nucleation of cholesterol·H2O using first-principles
calculations based on dispersion-augmented density functional theory.
For the lesser known monoclinic polymorph, we obtain a fully extended
H-bonded network in a structure akin to that of hexagonal ice. We
show that the energy of the monoclinic and triclinic polymorphs is
similar, strongly suggesting that kinetic and environmental effects
play a significant role in determining polymorph nucleation. Furthermore,
we find evidence in support of various O–H···O
bonding motifs in both polymorphs that may result in hydroxyl disorder.
We have been able to explain, via computation, why a single cholesterol
bilayer in hydrated membranes always crystallizes in the monoclinic
polymorph. We rationalize what we believe is a single-crystal to single-crystal
transformation of the monoclinic form on increased interlayer growth
beyond that of a single cholesterol bilayer, interleaved by a water
bilayer. We show that the ice-like structure is also relevant to the
related cholestanol·2H2O and stigmasterol·H2O crystals. The structure of stigmasterol hydrate both as
a trilayer film at the air–water interface and as a macroscopic
crystal further assists us in understanding the polymorphic and thermal
behavior of cholesterol·H2O. Finally, we posit a possible
role for one of the sterol esters in the crystallization of cholesterol·H2O in pathological environments, based on a composite of a
crystalline bilayer of cholesteryl palmitate bound epitaxially as
a nucleating agent to the monoclinic cholesterol·H2O form.
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Affiliation(s)
- Margarita Shepelenko
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovoth 7610001, Israel
| | - Anna Hirsch
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovoth 7610001, Israel
| | - Neta Varsano
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovoth 7610001, Israel
| | - Fabio Beghi
- Department of Chemistry, Università degli Studi di Milano, Milano I-20122, Italy
| | - Lia Addadi
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovoth 7610001, Israel
| | - Leeor Kronik
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovoth 7610001, Israel
| | - Leslie Leiserowitz
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovoth 7610001, Israel
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5
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Reinholdt P, Joensen LE, Petersen D, Szomek M, Mularski A, Simonsen AC, Kongsted J, Wüstner D. Photophysical and Structural Characterization of Intrinsically Fluorescent Sterol Aggregates. J Phys Chem B 2021; 125:5838-5852. [PMID: 34061522 DOI: 10.1021/acs.jpcb.1c00628] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Self-association of cholesterol into aggregates and crystals is a hallmark of developing atherosclerosis. Intrinsically fluorescent sterols, such as dehydroergosterol (DHE), can be used to study sterol aggregation by fluorescence spectroscopy and microscopy, but a thorough understanding of DHE's photophysical and structural properties in the aggregated state is missing. Here, we show that DHE forms submicron fluorescent aggregates when evaporated from an ethanol solution. Using atomic force microscopy, we find that DHE, like cholesterol, forms compact oblate-shape aggregates of <100 nm in diameter. DHE's fluorescence is lowered in the aggregate compared to the monomeric form, and characteristic spectral changes accompany the aggregation process. Electronic structure calculations of DHE dimers in water indicate that Frenkel-type exciton coupling contributes to the lowered DHE fluorescence in the aggregates. Using molecular dynamics (MD) simulations, we show that DHE forms compact aggregates on the nanosecond scale and with strong intermolecular attraction, in which a broad range of orientations, and therefore electronic couplings, will take place. Tight packing of DHE in aggregates also lowers the apparent absorption cross section, further reducing the molecular brightness of the aggregates. Our results pave the way for systematic solubility studies of intrinsically fluorescent analogues of biologically relevant sterols.
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Affiliation(s)
- Peter Reinholdt
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Lütje E Joensen
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Daniel Petersen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Maria Szomek
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Anna Mularski
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Adam Cohen Simonsen
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Jacob Kongsted
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Daniel Wüstner
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
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6
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Ma GJ, Zhdanov VP, Park S, Sut TN, Cho NJ. Mechanistic Aspects of the Evolution of 3D Cholesterol Crystallites in a Supported Lipid Membrane via a Quartz Crystal Microbalance with Dissipation Monitoring. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:4562-4570. [PMID: 33834785 DOI: 10.1021/acs.langmuir.1c00174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The irreversible formation of cholesterol monohydrate crystals within biological membranes is the leading cause of various diseases, including atherosclerosis. Understanding the process of cholesterol crystallization is fundamentally important and could also lead to the development of improved therapeutic strategies. This has driven several studies investigating the effect of the environmental parameters on the induction of cholesterol crystallite growth and the structure of the cholesterol crystallites, while the kinetics and mechanistic aspects of the crystallite formation process within lipid membranes remain poorly understood. Herein, we fabricated cholesterol crystallites within a supported lipid bilayer (SLB) by adsorbing a cholesterol-rich bicellar mixture onto a glass and silica surface and investigated the real-time kinetics of cholesterol crystallite nucleation and growth using epifluorescence microscopy and quartz crystal microbalance with dissipation (QCM-D) monitoring. Microscopic imaging showed the evolution of the morphology of cholesterol crystallites from nanorod- and plate-shaped habits during the initial stage to mostly large, micron-sized three-dimensional (3D) plate-shaped crystallites in the end, which was likened to Ostwald ripening. QCM-D kinetics revealed unique signal responses during the later stage of the growth process, characterized by simultaneous positive frequency shifts, nonmonotonous energy dissipation shifts, and significant overtone dependence. Based on the optically observed changes in crystallite morphology, we discussed the physical background of these unique QCM-D signal responses and the mechanistic aspects of Ostwald ripening in this system. Together, our findings revealed mechanistic details of the cholesterol crystallite growth kinetics, which may be useful in biointerfacial sensing and bioanalytical applications.
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Affiliation(s)
- Gamaliel Junren Ma
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore
| | - Vladimir P Zhdanov
- Boreskov Institute of Catalysis, Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - Soohyun Park
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore
| | - Tun Naw Sut
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore
| | - Nam-Joon Cho
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore
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7
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Al-Handawi MB, Commins P, Karothu DP, Raj G, Li L, Naumov P. Mechanical and Crystallographic Analysis of Cholesterol Crystals Puncturing Biological Membranes. Chemistry 2018; 24:11493-11497. [PMID: 29877594 DOI: 10.1002/chem.201802251] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Indexed: 12/31/2022]
Abstract
Ischemic heart disease often leads to myocardial infarction and remains the most common cause for death in humans. Although the exact impetus for the infarction remains elusive, a mechanism has been proposed that relates the disease to the observed high cholesterol levels in the body. The mechanism claims that cholesterol crystallizes inside the arterial plaque into needle-shaped crystals. The crystals puncture the fibrous cap of the plaque, whereby the necrotic contents of the plaque are spilled, subsequently clotting the blood vessels. This hypothesis has not been given sufficient attention partly due to the purported softness of the organic crystals and the common platy habit of the known crystal forms of cholesterol. In this work it is shown that, from hydrophobic solutions that attempt to emulate the plaque contents, a new solid form of cholesterol crystallizes as prisms with mucronate tips, and they are sufficiently strong to puncture a lamb pericardium, which mimics the plaque cap. The properties of the crystals were assessed by mechanical, structural, and crystallographic analyses. The results support the hypothesis that the cholesterol crystals can be considered, at least within the framework of the proposed mechanism, a possible cause of myocardial infarction.
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Affiliation(s)
| | | | | | - Gijo Raj
- New York University Abu Dhabi, Abu Dhabi, UAE
| | - Liang Li
- New York University Abu Dhabi, Abu Dhabi, UAE
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8
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Varsano N, Dadosh T, Kapishnikov S, Pereiro E, Shimoni E, Jin X, Kruth HS, Leiserowitz L, Addadi L. Development of Correlative Cryo-soft X-ray Tomography and Stochastic Reconstruction Microscopy. A Study of Cholesterol Crystal Early Formation in Cells. J Am Chem Soc 2016; 138:14931-14940. [PMID: 27934213 DOI: 10.1021/jacs.6b07584] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
We have developed a high resolution correlative method involving cryo-soft X-ray tomography (cryo-SXT) and stochastic optical reconstruction microscopy (STORM), which provides information in three dimensions on large cellular volumes at 70 nm resolution. Cryo-SXT morphologically identified and localized aggregations of carbon-rich materials. STORM identified specific markers on the desired epitopes, enabling colocalization between the identified objects, in this case cholesterol crystals, and the cellular environment. The samples were studied under ambient and cryogenic conditions without dehydration or heavy metal staining. The early events of cholesterol crystal development were investigated in relation to atherosclerosis, using as model macrophage cell cultures enriched with LDL particles. Atherosclerotic plaques build up in arteries in a slow process involving cholesterol crystal accumulation. Cholesterol crystal deposition is a crucial stage in the pathological cascade. Our results show that cholesterol crystals can be identified and imaged at a very early stage on the cell plasma membrane and in intracellular locations. This technique can in principle be applied to other biological samples where specific molecular identification is required in conjunction with high resolution 3D-imaging.
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Affiliation(s)
| | | | - Sergey Kapishnikov
- Soft Matter and Functional Materials, Helmholtz-Zentrum Berlin , Albert-Einstein-Strasse 15, D-12489 Berlin, Germany
| | - Eva Pereiro
- ALBA Synchrotron Light Source, MISTRAL Beamline-Experiments Division, 08290 Cerdanyola del Valles, Barcelona, Spain
| | | | - Xueting Jin
- Experimental Atherosclerosis Section, National Heart, Lung, and Blood Institute, National Institutes of Health , Bethesda, Maryland 20892-1422, United States
| | - Howard S Kruth
- Experimental Atherosclerosis Section, National Heart, Lung, and Blood Institute, National Institutes of Health , Bethesda, Maryland 20892-1422, United States
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9
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Varsano N, Fargion I, Wolf SG, Leiserowitz L, Addadi L. Formation of 3D Cholesterol Crystals from 2D Nucleation Sites in Lipid Bilayer Membranes: Implications for Atherosclerosis. J Am Chem Soc 2015; 137:1601-7. [DOI: 10.1021/ja511642t] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Neta Varsano
- Department
of Structural Biology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Iael Fargion
- Department
of Structural Biology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Sharon G. Wolf
- Department
of Chemical Research Support, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Leslie Leiserowitz
- Department
of Materials and Interfaces, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Lia Addadi
- Department
of Structural Biology, Weizmann Institute of Science, Rehovot 76100, Israel
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10
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Losensky L, Chiantia S, Holland G, Laue M, Petran A, Liebscher J, Arbuzova A. Self-assembly of a cholesteryl-modified nucleoside into tubular structures from giant unilamellar vesicles. RSC Adv 2015. [DOI: 10.1039/c4ra11289j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Phosphatidylcholine-assisted self-assembly of cholesterylaminouridine into hollow needle-like structures was observed at room temperature.
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Affiliation(s)
- Luisa Losensky
- Humboldt-Universität zu Berlin
- Institut für Biologie
- 10115 Berlin
- Germany
| | | | | | | | - Anca Petran
- National Institute of Research and Development for Isotopic and Molecular Technologies
- RO-400293 Cluj-Napoca
- Romania
| | - Jürgen Liebscher
- National Institute of Research and Development for Isotopic and Molecular Technologies
- RO-400293 Cluj-Napoca
- Romania
| | - Anna Arbuzova
- Humboldt-Universität zu Berlin
- Institut für Biologie
- 10115 Berlin
- Germany
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11
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Yu JK, Pan H, Huang SM, Huang NL, Yao CC, Hsiao KM, Wu CW. Calcium content of different compositions of gallstones and pathogenesis of calcium carbonate gallstones. Asian J Surg 2012; 36:26-35. [PMID: 23270822 DOI: 10.1016/j.asjsur.2012.06.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Revised: 05/02/2012] [Accepted: 05/31/2012] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND/OBJECTIVES Our aim was to investigate the calcium content of different gallstone compositions and the pathogenic mechanisms of calcium carbonate gallstones. METHODS Between August 2001 and July 2007, gallstones from 481 patients, including 68 calcium carbonate gallstones, were analyzed for total calcium content. Gallbladder bile samples from 33 cases and six controls were analyzed for pH, carbonate anion level, free-ionized calcium concentration and saturation index for calcium carbonate. RESULTS Total calcium content averaged 75.6 %, 11.8 %, and 4.2 % for calcium carbonate, calcium bilirubinate and cholesterol gallstones. In 29.4 % of patients, chronic and/or intermittent cystic duct obstructions were caused by polypoid lesions in the neck region and 70.6 % were caused by stones. A total of 82 % of patients had chronic low-grade inflammation of the gallbladder wall and 18.0 % had acute inflammatory exacerbations. In the bile, we found the mean pH, mean carbonate anion, free-ionized calcium concentrations, and mean saturation index for calcium carbonate to be elevated in comparison to controls. CONCLUSION From our study, we found chronic and/or intermittent cystic duct obstructions and low-grade GB wall inflammation lead to GB epithelium hydrogen secretion dysfunction. Increased calcium ion efflux into the GB lumen combined with increased carbonate anion presence increases SI_CaCO(3) from 1 to 22.4. Thus, in an alkaline milieu with pH 7.8, calcium carbonate begins to aggregate and precipitate.
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Affiliation(s)
- Ji-Kuen Yu
- Division of General Surgery, Department of Surgery, Taichung Metroharbor Tung's Memorial Hospital, Wuchi Town, Taichung County, Taiwan, ROC
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12
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Abstract
Abstract
GDIS is a freely available chemical visualization program for displaying molecules, periodic structures, and crystal morphologies. A key feature of the package is the mechanism for constructing and manipulating arbitrary crystal surfaces. This enables GDIS to offer a powerful tool set for computing surface and interfacial properties and predicting crystal morphologies. Also included are modules for computing powder diffraction patterns, generating molecular surfaces, and analyzing dynamics trajectories. Further, the program may be used as a graphical interface to simplify the construction of input files for the command line codes: GULP, GAMESS(US), and SIESTA.
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13
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Cromie SRT, Ballone P. Structural motifs of cholesterol nanoparticles. J Chem Phys 2009; 131:034906. [DOI: 10.1063/1.3179683] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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14
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Jaya Prakash M, Raghavaiah P, Krishna Y, Radhakrishnan T. Growing Molecular Crystals on Inorganic Crystals: Polar Structure Induced by Noncentrosymmetric Templates. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200704031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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15
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Jayaâ
Prakash M, Raghavaiah P, Krishna Y, Radhakrishnan T. Growing Molecular Crystals on Inorganic Crystals: Polar Structure Induced by Noncentrosymmetric Templates. Angew Chem Int Ed Engl 2008; 47:3969-72. [DOI: 10.1002/anie.200704031] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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16
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Uskoković V. Insights into morphological nature of precipitation of cholesterol. Steroids 2008; 73:356-69. [PMID: 18215404 DOI: 10.1016/j.steroids.2007.12.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2007] [Revised: 11/09/2007] [Accepted: 12/06/2007] [Indexed: 10/22/2022]
Abstract
Additional effects on the previously reported procedure of precipitation of narrowly dispersed and well-defined, brick-shaped cholesterol particles, including non-solvent addition rate, temperature, solvent purity, aging treatments, ultrasound agitation and fine mechanical effects were investigated. Based on the presented results, significant morphological sensitivity of cholesterol precipitation processes upon variations from the standard established procedure of crystallization is induced. However, the tendency of cholesterol to crystallize in the form of biaxially grown particles was evidenced as dominating the precipitation processes, irrespective of any modifications of experimental parameters involved in the preparation procedure investigated hereby. Prolonged aging time and temperature effects lead to "face-to-face" aggregation of particles, promoted by the discrepancy in surface charges between particle sides and faces. In light of these observations, the mechanism of precipitation of cholesterol is further discussed.
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Affiliation(s)
- Vuk Uskoković
- Center for Advanced Materials Processing, Clarkson University, Potsdam, NY 13699, USA.
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17
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Uskoković V. Composites comprising cholesterol and carboxymethyl cellulose. Colloids Surf B Biointerfaces 2008; 61:250-61. [DOI: 10.1016/j.colsurfb.2007.08.014] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2007] [Revised: 08/29/2007] [Accepted: 08/30/2007] [Indexed: 11/15/2022]
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18
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Uskoković V, Matijević E. Uniform particles of pure and silica-coated cholesterol. J Colloid Interface Sci 2007; 315:500-11. [PMID: 17673225 DOI: 10.1016/j.jcis.2007.07.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2007] [Revised: 07/03/2007] [Accepted: 07/05/2007] [Indexed: 11/18/2022]
Abstract
Uniform crystalline colloidal cholesterol particles of narrow size distribution were obtained by precipitation. The method consisted of adding a miscible non-solvent (water) into cholesterol solutions of different alcohols and acetone, without any additives. The properties of the resulting particles depended in a sensitive way on the concentration of all reactants, temperature, pH, ionic strength, and aging time. The major observed effects were due to the solubility of cholesterol, which was strongly affected by the solvent mixture and temperature. Precipitation in 1-propanol/water system yielded stable dispersions of well-defined particles, which were used to evaluate the effects of different experimental parameters on their properties. Aging of stable dispersions resulted in multi-layered aggregation of the primary platelets, the degree and rate of which process was strongly affected by temperature. Finally, it was shown that the colloidal cholesterol particles could be coated with homogeneous silica layers in order to alter their surface characteristics.
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Affiliation(s)
- Vuk Uskoković
- Center for Advanced Materials Processing, Clarkson University, Potsdam, NY 13699-5814, USA
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19
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Usher CR, Baltrusaitis J, Grassian VH. Spatially resolved product formation in the reaction of formic acid with calcium carbonate (1014): the role of step density and adsorbed water-assisted ion mobility. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:7039-45. [PMID: 17500573 DOI: 10.1021/la062866+] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The reaction of calcium carbonate (1014) single-crystal surfaces with formic acid (HCOOH) vapor was investigated using atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). AFM images indicate the reaction produces rather well-defined crystallites, preferentially at step edges and at distinct angles to one another and mirroring the rhombohedral structure of the calcite surface, while exposing unreacted carbonate surface. The size and surface density of the crystallites depend upon substrate step density, exposure time, and relative humidity. XPS data confirmed the crystallite composition as the expected calcium formate product. The AFM images show erosion and pit formation of the calcite surface in the vicinity of the product crystallites, clearly providing the spatially resolved characterization of the source of Ca ions. AFM experiments exploring the effects of water vapor on the reacted surface show that the calcium formate crystallites are mobile under conditions of high relative humidity, combining to form larger crystallites and nanometer-sized crystals with an orthorhombohedral habit consistent with the alpha form, as confirmed by X-ray diffraction. The implications for the reactions described here are discussed.
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Affiliation(s)
- Courtney R Usher
- Department of Chemistry and the Central Microscopy Research Facility, University of Iowa, Iowa City, IA 52242, USA
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20
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Liao X, Wiedmann TS. Formation of Cholesterol Crystals at a Mucin Coated Substrate. Pharm Res 2006; 23:2413-6. [PMID: 16927188 DOI: 10.1007/s11095-006-9004-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2005] [Accepted: 02/28/2006] [Indexed: 11/29/2022]
Abstract
PURPOSE High-resolution, tapping-mode atomic force microscopy (AFM) was used to monitor the early stage of the formation of cholesterol crystals under simulated conditions of the gallbladder environment. METHODS AFM images of phosphatidylcholine/cholesterol vesicles were obtained using a mucin-coated mica substrate. RESULTS The vesicles appeared flattened with diameters from 100 to 300 nm and heights that varied from 10 to 100 nm. Phosphatidylcholine/cholesterol vesicles were mixed with bile salt solutions to yield supersaturated (with respect to cholesterol) dispersions, which were then placed onto mica, silanized mica, and mucin-covered mica substrates. After equilibration, sub-micron sized, plate-like structures were observed at the mica and mucin covered surface, but none were seen at the silanized surface. The morphology was characterized as it pertains to the relative growth rates of the crystal faces. CONCLUSION The comparison of these results with literature reports of cholesterol crystals grown in solution suggests that the physical chemical properties of the surface have an important influence in determining the nucleation and subsequent crystal growth of cholesterol.
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Affiliation(s)
- Xiangmin Liao
- Department of Pharmaceutics, University of Minnesota, 308 Harvard St., SE Minneapolis, Minnesota 55455, USA
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Laird DF, Mucalo MR, Yokogawa Y. Growth of calcium hydroxyapatite (Ca-HAp) on cholesterol and cholestanol crystals from a simulated body fluid: A possible insight into the pathological calcifications associated with atherosclerosis. J Colloid Interface Sci 2006; 295:348-63. [PMID: 16229855 DOI: 10.1016/j.jcis.2005.09.013] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2005] [Revised: 08/05/2005] [Accepted: 09/04/2005] [Indexed: 11/21/2022]
Abstract
An experimental study into calcium phosphate (CP) nucleation and growth on cholesterol and cholestanol surfaces from a supersaturated simulated body fluid (SBF) is presented with the overall aim of gaining some fundamental insights into the pathological calcifications associated with atherosclerosis. Soaking of pressed cholesterol disks at physiological temperature in SBF solutions was found to lead to CP nucleation and growth if the disks were surface roughened and if an SBF with concentrations of the calcium and hydrogen phosphate ions at 2.25x physiological concentrations was used. The CP phase deposited was shown via SEM micrographs to possess a florette type morphology akin to that observed in earlier reported studies. The use of recrystallised cholesterol and cholestanol microcrystals as substrates for soaking in SBF facilitated the observation of CP deposition. In general, cholesterol recrystallised from polar solvents like 95% ethanol as a cholesterol monohydrate phase which was a better substrate for CP growth than cholesterol recrystallised from more non-polar solvents (e.g., benzene) which produced anhydrous cholesterol phases. CP was also observed to form on recrystallised cholestanol microcrystals, a molecule closely related to cholesterol. Inductively coupled plasma optical emission spectrometry (ICP-OES) data gave confirmation that Ca:P mole ratios of the grown CP were 1.3-1.5 suggesting a mixed phase of octacalcium phosphate (OCP) and Ca-deficient HAp and that the CP coating grows (with time of soaking) on the substrates after nucleation in the SBF growth medium. Infrared (IR) spectra of the extracted coatings from the cholesterol substrates confirmed that the CP phase deposited is a semi crystalline HAp with either carbonate substituted into its structure or else co-deposited as calcium carbonate. Soaking experiments involving modified cholesterol substrates in which the OH group in the molecule was replaced with the oleiyl or phosphonate group showed no CP nucleation and growth. This observation illustrates the importance of the known epitaxial relationship between cholesterol and HAp (which theoretically predicts favourable deposition of one phase upon the other) and the consequences of its destruction (by chemical modification of the cholesterol). In the case of the phosphorylated cholesterol, failure of this substrate to nucleate CP phases may have also been caused by the reduction in concentration of free solution Ca2+ in the SBF medium by complexation with the phosphonate groups on the phosphorylated cholesterol. This would have reduced the ion product of Ca2+ and inorganic phosphate and lowered the degree of supersaturation in the SBF medium.
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Affiliation(s)
- Dougal F Laird
- Chemistry Department, University of Waikato, Private Bag 3105, Hamilton 2020, New Zealand
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Frincu MC, Fogarty CE, Swift JA. Epitaxial relationships between uric acid crystals and mineral surfaces: a factor in urinary stone formation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:6524-6529. [PMID: 15274547 DOI: 10.1021/la049091u] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Uric acid (C5H4N4O3) is one of the final products of purine metabolism. Its concentration balance is maintained in the kidneys, but compromised kidney function can result in its crystallization either in the renal tract or in the interstitial fluid of joints. In physiological deposits, crystalline uric acid is most frequently found either in a protonated state (anhydrous or dihydrate phases) or as a deprotonated urate ion (sodium or ammonium salts). Often these precipitates are found in association with a number of mineral phases (e.g., calcium oxalates, calcium phosphates, and magnesium phosphates). Their frequent and common coexistence suggests that synergistic relationships between these crystalline phases may exist. A comprehensive list of different heterogeneous uric acid/uric acid and uric acid/mineral interfaces that are epitaxially matched was generated with the lattice-matching program EpiCalc. Two hundred twenty-five coincident epitaxial matches and four commensurate epitaxial matches were identified using this screening procedure.
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Affiliation(s)
- M Crina Frincu
- Department of Chemistry, Georgetown University, 37th and "O" Streets NW, Washington, D.C. 20057-1227, USA
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