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Amjid U, Aziz U, Habib U, Jabeen I. Biological regulatory network analysis for targeting the mitochondrial calcium uniporter (MCU) mediated calcium (Ca 2+) transport in neurodegenerative disorders. Cell Biochem Funct 2024; 42:e4082. [PMID: 38944766 DOI: 10.1002/cbf.4082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 05/30/2024] [Accepted: 06/18/2024] [Indexed: 07/01/2024]
Abstract
Calcium (Ca2+) has been observed as the most important ion involved in a series of cellular processes and its homeostasis is critical for normal cellular functions. Mitochondrial calcium uniporter (MCU) complex has been recognized as the most important calcium-specific channel located in the inner mitochondrial membrane and is one of the major players in maintaining the Ca2+ homeostasis by transporting Ca2+ across the mitochondrial membrane. Furthermore, dysregulation of the mitochondrial Ca2+ homeostasis has been orchestrated to neurodegenerative response. This necessitates quantitative evaluation of the MCU-dependent mROS production and subsequent cellular responses for more specific therapeutic interventions against neurodegenerative disorders. Towards this goal, here we present a biological regulatory network of MCU to dynamically simulate the MCU-mediated ROS production and its response in neurodegeneration. Previously, ruthenium complex RuRed and its derivatives have been reported to show low nM to high µM potency against MCU to maintain cytosolic Ca2+ (cCa2+) homeostasis by modulating mitochondrial Ca2+ (mCa2+) uptake. Therefore, structural modeling and dynamic simulation of MCU pore-forming subunit is performed to probe the interaction profiling of previously reported Ru265 and its derivatives compounds with MCU. The current study highlighted MCU as a potential drug target in neurodegenerative disorders. Furthermore, ASP261 and GLU264 amino acid residues in DIME motif of MCU pore-forming subunits are identified as crucial for modulating the activity of MCU in neurodegenerative disorders.
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Affiliation(s)
- Umar Amjid
- School of Interdisciplinary Engineering & Sciences (SINES), National University of Sciences & Technology (NUST), Islamabad, Pakistan
- Department of Paediatrics and Child Health, Medical College, Aga Khan University Hospital, Karachi, Pakistan
| | - Ubair Aziz
- School of Interdisciplinary Engineering & Sciences (SINES), National University of Sciences & Technology (NUST), Islamabad, Pakistan
| | - Uzma Habib
- School of Interdisciplinary Engineering & Sciences (SINES), National University of Sciences & Technology (NUST), Islamabad, Pakistan
| | - Ishrat Jabeen
- School of Interdisciplinary Engineering & Sciences (SINES), National University of Sciences & Technology (NUST), Islamabad, Pakistan
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2
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Pumroy RA, De Jesús-Pérez JJ, Protopopova AD, Rocereta JA, Fluck EC, Fricke T, Lee BH, Rohacs T, Leffler A, Moiseenkova-Bell V. Molecular details of ruthenium red pore block in TRPV channels. EMBO Rep 2024; 25:506-523. [PMID: 38225355 PMCID: PMC10897480 DOI: 10.1038/s44319-023-00050-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 12/19/2023] [Accepted: 12/21/2023] [Indexed: 01/17/2024] Open
Abstract
Transient receptor potential vanilloid (TRPV) channels play a critical role in calcium homeostasis, pain sensation, immunological response, and cancer progression. TRPV channels are blocked by ruthenium red (RR), a universal pore blocker for a wide array of cation channels. Here we use cryo-electron microscopy to reveal the molecular details of RR block in TRPV2 and TRPV5, members of the two TRPV subfamilies. In TRPV2 activated by 2-aminoethoxydiphenyl borate, RR is tightly coordinated in the open selectivity filter, blocking ion flow and preventing channel inactivation. In TRPV5 activated by phosphatidylinositol 4,5-bisphosphate, RR blocks the selectivity filter and closes the lower gate through an interaction with polar residues in the pore vestibule. Together, our results provide a detailed understanding of TRPV subfamily pore block, the dynamic nature of the selectivity filter and allosteric communication between the selectivity filter and lower gate.
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Affiliation(s)
- Ruth A Pumroy
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - José J De Jesús-Pérez
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Anna D Protopopova
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Julia A Rocereta
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Edwin C Fluck
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Tabea Fricke
- Institute for Neurophysiology, Hannover Medical School, 30625, Hannover, Germany
| | - Bo-Hyun Lee
- Department of Physiology and Convergence Medical Science, Institute of Health Sciences, Gyeongsang National University Medical School, Jinju, Korea
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers University, Newark, NJ, 07103, USA
| | - Tibor Rohacs
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers University, Newark, NJ, 07103, USA
| | - Andreas Leffler
- Institute for Neurophysiology, Hannover Medical School, 30625, Hannover, Germany
| | - Vera Moiseenkova-Bell
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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3
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Huang Z, Wilson JJ. Structure-Activity Relationships of Metal-Based Inhibitors of the Mitochondrial Calcium Uniporter. ChemMedChem 2023; 18:e202300106. [PMID: 37015871 DOI: 10.1002/cmdc.202300106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 04/01/2023] [Accepted: 04/04/2023] [Indexed: 04/06/2023]
Abstract
The mitochondrial calcium uniporter (MCU) is a transmembrane protein that is responsible for mediating mitochondrial calcium (mCa2+ ) uptake. Given this critical function, the MCU has been implicated as an important target for addressing various human diseases. As such, there has a been growing interest in developing small molecules that can inhibit this protein. To date, metal coordination complexes, particularly multinuclear ruthenium complexes, are the most widely investigated MCU inhibitors due to both their potent inhibitory activities as well as their longstanding use for this application. Recent efforts have expanded the metal-based toolkit for MCU inhibition. This concept paper summarizes the development of new metal-based inhibitors of the MCU and their structure-activity relationships in the context of improving their potential for therapeutic use in managing human diseases related to mCa2+ dysregulation.
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Affiliation(s)
- Zhouyang Huang
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA
| | - Justin J Wilson
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA
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Ribeiro JC, Tölke ED, Demarco D. Secretory Patterns in Colleters of Apocynaceae. PLANTS 2021; 10:plants10122770. [PMID: 34961240 PMCID: PMC8703501 DOI: 10.3390/plants10122770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 10/20/2021] [Accepted: 10/21/2021] [Indexed: 11/16/2022]
Abstract
Colleters of Apocynaceae are glands related to different types of protection of vegetative and floral meristems through the production of mucilage or a mixture of many different compounds. Although several anatomical papers have shown histological and histochemical aspects of colleters of the family, almost nothing is known about their secretory process. In this study, we analyzed two types of colleters in Apocynaceae: one produces mucilage and lipophilic compounds, while the other produces an exclusively mucilaginous secretion. The secretory epidermis of the colleters of Allamanda schottii and Blepharodon bicuspidatum has a dense cytoplasm with organelles responsible for the production of mucilage and lipids. This heterogeneous secretion is released through granulocrine and eccrine mechanisms and is temporarily stored in a subcuticular space before crossing the cuticle. Conversely, colleters of Mandevilla splendens and Peplonia axillaris produce only mucilage and have a very different secretory apparatus. The mechanism of secretion is granulocrine, and the exudate is firstly accumulated in a large periplasmic space and later in an intramural space before crossing the cuticle. Notably, the structure of the cuticle varies according to the secretion composition. Although the colleters of the family are histologically similar, this study demonstrates a metabolic and subcellular variability previously unknown for Apocynaceae.
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Affiliation(s)
- Josiana Cristina Ribeiro
- Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, Sao Paulo 05508-090, Brazil
| | - Elisabeth Dantas Tölke
- Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, Sao Paulo 05508-090, Brazil
| | - Diego Demarco
- Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, Sao Paulo 05508-090, Brazil
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Lavrov AI, Bolshakov FV, Tokina DB, Ereskovsky AV. Fine details of the choanocyte filter apparatus in asconoid calcareous sponges (Porifera: Calcarea) revealed by ruthenium red fixation. ZOOLOGY 2021; 150:125984. [PMID: 34896757 DOI: 10.1016/j.zool.2021.125984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Revised: 12/02/2021] [Accepted: 12/05/2021] [Indexed: 10/19/2022]
Abstract
Sponges (phylum Porifera) are highly specialized filter-feeding metazoans, pumping and filtering water with a network of canals and chambers, the aquiferous system. Most sponges have a leuconoid aquiferous system, characterized by choanocytes organized in small spherical chambers connected with ambient water by a complex net of canals. Such organization requires substantial pressure difference to drive water through an elaborate system of canals, so the choanocytes in leuconoid sponges have several structural features to generate pressure difference. In contrast, it is generally accepted that asconoid and syconoid sponges with long choanocyte tubes or large choanocyte chambers have no similar structures in their choanocytes. The present study is devoted to the detailed ultrastructural analysis of the choanocytes and their filter apparatus in the asconoid calcareous sponge Leucosolenia variabilis. The general structure of L. variabilis choanocytes is similar to that described for other sponge species. However, the fixation with 0.1% ruthenium red allowed us to reveal for the first time a complex of glycocalyx structures (vanes on the flagella, a fine glycocalyx sealing microvilli in the collar, and a glycocalyx strainer, embedding the apical parts of neighboring collars) in the choanocytes of L. variabilis, which are traditionally associated with the pumping and filtration process in leuconoid demosponges. All revealed glycocalyx structures have dimensions and locations similar to those found in the choanocyte chambers of some demosponges. The data suggest that L. variabilis utilizes the principles of water pumping and filtration similar to those in demosponges and revealed glycocalyx structures are potentially crucial for these processes. It seems that sponges from distant phylogenetic lineages and with different body plans rely on common principles of choanoderm organization for effective pumping and filtration of water. However, while some adaptation for effective pumping and filtration of water have possibly arisen before the diversification of Porifera, others have appeared independently in different lineages.
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Affiliation(s)
- Andrey I Lavrov
- Pertsov White Sea Biological Station, Biological Faculty, Lomonosov Moscow State University, 129281, Leninskie gory 1-12, Moscow, Russia.
| | - Fyodor V Bolshakov
- Pertsov White Sea Biological Station, Biological Faculty, Lomonosov Moscow State University, 129281, Leninskie gory 1-12, Moscow, Russia
| | - Daria B Tokina
- Institut Méditerranéen de Biodiversité et d'Ecologie marine et continentale (IMBE), Aix Marseille University, CNRS, IRD, Avignon University, Station Marine d'Endoume, Rue de la Batterie des Lions, 13007, Marseille, France
| | - Alexander V Ereskovsky
- Institut Méditerranéen de Biodiversité et d'Ecologie marine et continentale (IMBE), Aix Marseille University, CNRS, IRD, Avignon University, Station Marine d'Endoume, Rue de la Batterie des Lions, 13007, Marseille, France; Dept. Embryology, Faculty of Biology, Saint-Petersburg State University, Universitetskaya emb. 7/9, 199034, Saint-Petersburg, Russia; Koltzov Institute of Developmental Biology of Russian Academy of Sciences, Moscow, Russia
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6
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Transmission Electron Microscopy Tilt-Series Data from In-Situ Chondrocyte Primary Cilia. DATA 2021. [DOI: 10.3390/data6110118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The primary cilium has recently become the focus of intensive investigations into understanding the physical structure and processes of eukaryotic cells. This paper describes two tilt-series image datasets, acquired by transmission electron microscopy, of in situ chick-embryo sternal-cartilage primary cilia. These data have been released under an open-access licence, and are well suited to tomographic reconstruction and modelling of the cilium.
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7
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Sheng W, Harden SW, Tan Y, Krause EG, Frazier CJ. Dendritic osmosensors modulate activity-induced calcium influx in oxytocinergic magnocellular neurons of the mouse PVN. eLife 2021; 10:e63486. [PMID: 34250900 PMCID: PMC8457833 DOI: 10.7554/elife.63486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 07/11/2021] [Indexed: 11/13/2022] Open
Abstract
Hypothalamic oxytocinergic magnocellular neurons have a fascinating ability to release peptide from both their axon terminals and from their dendrites. Existing data indicates that the relationship between somatic activity and dendritic release is not constant, but the mechanisms through which this relationship can be modulated are not completely understood. Here, we use a combination of electrical and optical recording techniques to quantify activity-induced calcium influx in proximal vs. distal dendrites of oxytocinergic magnocellular neurons located in the paraventricular nucleus of the hypothalamus (OT-MCNs). Results reveal that the dendrites of OT-MCNs are weak conductors of somatic voltage changes; however, activity-induced dendritic calcium influx can be robustly regulated by both osmosensitive and non-osmosensitive ion channels located along the dendritic membrane. Overall, this study reveals that dendritic conductivity is a dynamic and endogenously regulated feature of OT-MCNs that is likely to have substantial functional impact on central oxytocin release.
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Affiliation(s)
- Wanhui Sheng
- Department of Pharmacodynamics, College of Pharmacy, University of FloridaGainesvilleUnited States
| | - Scott W Harden
- Department of Pharmacodynamics, College of Pharmacy, University of FloridaGainesvilleUnited States
| | - Yalun Tan
- Department of Pharmacodynamics, College of Pharmacy, University of FloridaGainesvilleUnited States
- Department of Anesthesiology, School of Medicine, Stanford UniversityStanfordUnited States
| | - Eric G Krause
- Department of Pharmacodynamics, College of Pharmacy, University of FloridaGainesvilleUnited States
- Center for Integrative Cardiovascular and Metabolic Diseases, University of FloridaGainesvilleUnited States
- Evelyn F. and William L. McKnight Brain Institute, University of FloridaGainesvilleUnited States
| | - Charles J Frazier
- Department of Pharmacodynamics, College of Pharmacy, University of FloridaGainesvilleUnited States
- Center for Integrative Cardiovascular and Metabolic Diseases, University of FloridaGainesvilleUnited States
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8
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Burtseva O, Baulina O, Zaytseva A, Fedorenko T, Chekanov K, Lobakova E. In vitro Biofilm Formation by Bioluminescent Bacteria Isolated from the Marine Fish Gut. MICROBIAL ECOLOGY 2021; 81:932-940. [PMID: 33247364 DOI: 10.1007/s00248-020-01652-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 11/24/2020] [Indexed: 06/12/2023]
Abstract
The internal surface of the animal gastrointestinal tract is covered by microbial biofilms. They play an important role in the development and functioning of the host organism and protect it against pathogens. Microbial communities of gastrointestinal biofilms are less elucidated than luminal microbiota. Therefore, the studies of biofilm formation by gastrointestinal microorganisms are a topical issue. For the first time, we report the formation of a biofilm in vitro by the strains of bioluminescent bacteria isolated from the intestines of marine fish. These bacteria exhibit co-aggregation and tend to attach to solid surfaces. The attachment of cells is accompanied by appearance of the pili. Then, we observed the formation of microcolonies and the production of extracellular polymer substances (EPSs) connecting bacterial cells into an integrated system. The presence of acidic polysaccharides is shown in the EPS when using the ruthenium red staining. Acidic polysaccharides in this matrix is a biochemical evidence of microbial biofilms. On the fibers of the polymer matrix, these bacteria form the "mushroom body"-type structures. Matured biofilms exhibit a specific three-dimensional architecture with pores and channels formed by cells and EPS. We also demonstrated the formation of a biofilm by binary culture of the luminous enterobacterium Kosakonia cowanii and a Gram-positive Macrococcus sp. The data obtained help to understand the role of these bacteria in the intestines of fish. They lead to a new study in the field of investigation of the intestinal microbiome of fish.
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Affiliation(s)
- Olga Burtseva
- Department of Bioengineering, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Olga Baulina
- Department of Bioengineering, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Anna Zaytseva
- Department of Bioengineering, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Tatiana Fedorenko
- Department of Bioengineering, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Konstantin Chekanov
- Department of Bioengineering, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia.
- National Research Nuclear University MEPhi, Centre for Humanities Research and Technology, Moscow, Russia.
| | - Elena Lobakova
- Department of Bioengineering, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
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Kublanovskaya A, Baulina O, Chekanov K, Lobakova E. The microalga Haematococcus lacustris (Chlorophyceae) forms natural biofilms in supralittoral White Sea coastal rock ponds. PLANTA 2020; 252:37. [PMID: 32778946 DOI: 10.1007/s00425-020-03438-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 07/29/2020] [Indexed: 06/11/2023]
Abstract
Haematococcus lacustris inhabits supralittoral rock ponds and forms, under natural conditions, biofilms including layered cyanobacterial and fermentative microbial mats. Dry mats, formed under extremely stressful conditions, contained only haematocysts. Under favorable growth conditions, modeled for dry biofilms in vitro, microalgal free-living stages were detected. Haematococcus lacustris is the microalga known for its high potential to survive under a wide range of unfavorable conditions, particularly in the supralittoral temporal rock ponds of the White Sea. Previously, we described microbial communities containing H. lacustris in this region. In many cases, they were organized into systems exhibiting complex three-dimensional structure similar to that of natural biofilms. In this study, for the first time, we clarify structural description and provide microscopic evidence that these communities of H. lacustris and bacteria are assembled into the true biofilms. There are (1) simple single layer biofilms on the surface of rocks and macrophytic algae, (2) floccules (or flocs) not attached to a surface, (3) as well as stratified (layered) biofilms, wet, and dehydrated in nature. Being involved into primary organic production, H. lacustris and cyanobacteria are located exclusively in the upper layers of stratified biofilms, where they are capable to absorb sufficient for photosynthesis amount of light. The presence of acidic polysaccharides in the extracellular matrix revealed by specific staining with ruthenium red in the H. lacustris-containing microbial communities is a biochemical evidence of biofilm formation. Meanwhile, the presence of bacterial L-form is an ultrastructural confirmation of that fact. Under favorable conditions, modeled in vitro, H. lacustris from the dry microbial mats moves to the free-living states represented by vegetative palmelloid cells and motile zoospores. Owing to the fact that inside biofilms cells of microorganisms exist under stable conditions, we consider the biofilm formation as an additional mechanism that contributes to the survival of H. lacustris in the supralittoral zone of the White Sea.
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Affiliation(s)
- Anna Kublanovskaya
- Faculty of Biology, Lomonosov Moscow State University, 1-12 Leninskie Gory, Moscow, 119192, Russia.
| | - Olga Baulina
- Faculty of Biology, Lomonosov Moscow State University, 1-12 Leninskie Gory, Moscow, 119192, Russia
| | - Konstantin Chekanov
- Faculty of Biology, Lomonosov Moscow State University, 1-12 Leninskie Gory, Moscow, 119192, Russia
- Centre for Humanities Research and Technology, National Research Nuclear University MEPhI, 31 Kashirskoye highway, Moscow, 115522, Russia
| | - Elena Lobakova
- Faculty of Biology, Lomonosov Moscow State University, 1-12 Leninskie Gory, Moscow, 119192, Russia
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Woods JJ, Wilson JJ. Inhibitors of the mitochondrial calcium uniporter for the treatment of disease. Curr Opin Chem Biol 2019; 55:9-18. [PMID: 31869674 DOI: 10.1016/j.cbpa.2019.11.006] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 11/12/2019] [Accepted: 11/15/2019] [Indexed: 01/04/2023]
Abstract
The mitochondrial calcium uniporter (MCU) is a protein located in the inner mitochondrial membrane that is responsible for mitochondrial Ca2+ uptake. Under certain pathological conditions, dysregulation of Ca2+ uptake through the MCU results in cellular dysfunction and apoptotic cell death. Given the role of the MCU in human disease, researchers have developed compounds capable of inhibiting mitochondrial calcium uptake as tools for understanding the role of this protein in cell death. In this article, we describe recent findings on the role of the MCU in mediating pathological conditions and the search for small-molecule inhibitors of this protein for potential therapeutic applications.
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Affiliation(s)
- Joshua J Woods
- Robert F. Smith School for Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY 14853, USA; Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, 14583, USA
| | - Justin J Wilson
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, 14583, USA.
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11
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Reyes-Pardo H, Sánchez-Herrera DP. Mechanosensitive ion channel inhibitors promote the stiffening of the plasma membrane of mouse sensory neurons. SOFT MATTER 2019; 15:8320-8328. [PMID: 31565715 DOI: 10.1039/c9sm01230c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The mechanosensitivity of cells depends on the lipid-protein interactions of the plasma membrane. Affectations in the lipid region of the plasma membrane affect the transduction of mechanical forces, and any molecule that modifies the biophysical integrity of the lipid bilayer can alter the mechanical activity of the proteins inside the membrane. To understand whether inhibitors of mechanically activated ion channels affect the mechanical properties of the plasma membrane, we evaluated the rigidity of the membrane of sensory neurons of the DRG of mice using a variant of the scanning ion conductance microscopy method, which allows us to calculate the Young's modulus of individual cells before and after the perfusion of different doses of Gd3+, ruthenium red and GsMTx-4. Our results suggest that these molecules compromise the membrane by increasing the Young's modulus value, which indicates that the membrane becomes more rigid; these compounds act through different mechanisms and by a non-specific manner, each one shows a certain preference for specific cell subpopulations, depending on their cell size and their reactivity to isolectin B4. Our results support the idea that the biophysical properties that result from the interactions that arise in the membranes are part of the mechanotransduction process.
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Affiliation(s)
- Humberto Reyes-Pardo
- Unidad Monterrey, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Apodaca, Nuevo León, Mexico.
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12
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Abstract
Electron microscopy allows for studying bacterial ultrastructure at high resolutions. Two types of electron microscopes are used for this purpose. The transmission electron microscope allows for access to inner bacterial ultrastructure when imaging ultrathin sections as well as cell wall-attached structures by negative staining, whereas scanning electron microscopy allows for the detection of structures on the bacterial cell surface alone or to study the interplay between pneumococci and their host cells. This chapter deals with recommendations for well-adapted methodologies to examine pneumococcal ultrastructure in detail. Especially, we focus on the preservation of the pneumococcal capsular polysaccharide, which represents an important virulence factor of pneumococci. Since capsules are highly hydrated structures, the introduction of a new fixation protocol involving lysine acetate, ruthenium red, and osmium (LRR fixation) results in a very well-preserved capsular structure in such a way that the amount of capsular material bound on the bacterial surface can be compared within different serotypes. In our method, capsular ultrastructure is preserved without the need for serotype-specific antibodies, which have been used in other studies to preserve the pneumococcal capsule. In addition, the new LRR fixation allows for studying the presence or absence of capsular material during adhesion and invasion of pneumococci on epithelial or endothelial host cells in cell culture experiments.
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Abstract
Gallstone disease is caused by multiple pathogenic factors and is common worldwide. Most studies have focused on the significance of the biliary microbiome in gallstone pathogenesis. Areas covered: In this study, the epidemiology of gallstone diseases and the existence, composition, origin, and mechanisms of the biliary microbiota were reviewed. Mechanisms involved in promoting the formation of different types of gallstones were also emphasized. The antibiotic susceptibility of the biliary microbiota is briefly discussed because it may guide clinical strategies. Expert commentary: The biliary microbiome facilitates the formation of brown pigment stones. Although glycoprotein (mucin) may be pivotal for many promoting substances to coagulate and integrate relevant components, new mechanisms involving prostaglandins, oxysterols, oxygen free radicals, and lipopolysaccharides have been discovered. Furthermore, specific bacterial species such as Helicobacter and Salmonella are involved in the pathogenesis of cholesterol gallstones. Recently, metabolomics of the biliary microbiome has been used to determine the detailed mechanisms that promote gallstone formation. Previously, the bacterial effects involved in the pathogenesis of brown pigment stones have not been analyzed in detail. Whether the administration of antibiotics is related to prophylaxis for gallstone formation and gallstone-associated infections remains unclear.
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Affiliation(s)
- Yining Wang
- a Department of Gastroenterology , The First Affiliated Hospital of Nanchang University , Nanchang, Jiangxi , China.,b Joint Programme of Nanchang University and Queen Mary University of London , Nanchang , China
| | - Miao Qi
- a Department of Gastroenterology , The First Affiliated Hospital of Nanchang University , Nanchang, Jiangxi , China.,b Joint Programme of Nanchang University and Queen Mary University of London , Nanchang , China
| | - Cheng Qin
- a Department of Gastroenterology , The First Affiliated Hospital of Nanchang University , Nanchang, Jiangxi , China.,b Joint Programme of Nanchang University and Queen Mary University of London , Nanchang , China
| | - Junbo Hong
- a Department of Gastroenterology , The First Affiliated Hospital of Nanchang University , Nanchang, Jiangxi , China
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14
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First Ultrastructural and Molecular Phylogenetic Evidence from the Blastogregarines, an Early Branching Lineage of Plesiomorphic Apicomplexa. Protist 2018; 169:697-726. [DOI: 10.1016/j.protis.2018.04.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 04/13/2018] [Indexed: 11/20/2022]
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15
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Faccioli CK, Chedid RA, Mori RH, do Amaral AC, Vicentini IBF, Vicentini CA. Cytochemical features of the digestive tract mucosa of Hemisorubim platyrhynchos (Siluriformes: Pimelodidae). JOURNAL OF FISH BIOLOGY 2018; 92:1915-1928. [PMID: 29624674 DOI: 10.1111/jfb.13629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 03/29/2018] [Indexed: 06/08/2023]
Abstract
Membranous organelles, acid glycoconjugates and lipids were characterized in the digestive tract mucosa of Hemisorubim platyrhynchos by cytochemistry techniques. Two types of mucous-secreting cells were observed in the digestive tract epithelium: goblet cells in the oesophagus and intestine and epithelial cells in the stomach. These cells had a Golgi apparatus more developed than the other cell types. The cytochemical analysis revealed that secretory granules are reactive to acid glycoconjugates, varying in reaction intensity according to the region of the digestive tract. Acid glycoconjugate reactions were also observed in oesophageal epithelial cell microridges and in enterocyte microvilli. In the digestive tract, acid glycoconjugates act to protect the epithelial surface, increasing mucous viscosity, which facilitates the passage of food, prevents the binding of parasites and facilitates their removal. Through lipid staining, a coated membrane was observed around each secretory granule of the oesophageal and intestinal goblet cells, while gastric epithelial cells granules were fully reactive. Oxynticopeptic cells of the gastric glands showed lipid droplets in the cytoplasm and also in the mitochondrial matrix, which act as an energy reserve for these cells that have a high energy demand. Enterocytes showed a well-developed smooth endoplasmic reticulum, especially in the apical region of the cell, being related to absorption and resynthesis of lipids.
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Affiliation(s)
- C K Faccioli
- Federal University of Uberlândia - UFU, Institute of Biomedical Sciences, Department of Human Anatomy, 1720 Pará Avenue, 38, 400-902, Uberlândia, MG, Brazil
- São Paulo State University - UNESP, Institute of Biosciences, Letter and Exact Sciences, Post-Graduate Program in Animal Biology, 2265 Cristovão Colombo Street, 15054-000, São José do Rio Preto, SP, Brazil
| | - R A Chedid
- São Paulo State University - UNESP, Aquaculture Center of UNESP - CAUNESP, Post-Graduate Program in Aquaculture, Via de Acesso Professor Paulo Donato Castellane s/n, 14884-900, Jaboticabal, SP, Brazil
| | - R H Mori
- São Paulo State University - UNESP, Aquaculture Center of UNESP - CAUNESP, Post-Graduate Program in Aquaculture, Via de Acesso Professor Paulo Donato Castellane s/n, 14884-900, Jaboticabal, SP, Brazil
| | - A C do Amaral
- São Paulo State University - UNESP, Department of Biological Sciences, School of Sciences, 14-01 Engenheiro Luiz Edmundo Carrijo Coube Avenue, 17033-360, Bauru, SP, Brazil
| | - I B F Vicentini
- São Paulo State University - UNESP, Department of Biological Sciences, School of Sciences, 14-01 Engenheiro Luiz Edmundo Carrijo Coube Avenue, 17033-360, Bauru, SP, Brazil
| | - C A Vicentini
- São Paulo State University - UNESP, Department of Biological Sciences, School of Sciences, 14-01 Engenheiro Luiz Edmundo Carrijo Coube Avenue, 17033-360, Bauru, SP, Brazil
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16
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Jahn H, Oliveira IDES, Gross V, Martin C, Hipp A, Mayer G, Hammel JU. Evaluation of contrasting techniques for X-ray imaging of velvet worms (Onychophora). J Microsc 2018; 270:343-358. [PMID: 29469207 DOI: 10.1111/jmi.12688] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 12/20/2017] [Accepted: 01/29/2018] [Indexed: 01/04/2023]
Abstract
Non-invasive imaging techniques like X-ray computed tomography have become very popular in zoology, as they allow for simultaneous imaging of the internal and external morphology of organisms. Nevertheless, the effect of different staining approaches required for this method on samples lacking mineralized tissues, such as soft-bodied invertebrates, remains understudied. Herein, we used synchrotron radiation-based X-ray micro-computed tomography to compare the effects of commonly used contrasting approaches on onychophorans - soft-bodied invertebrates important for studying animal evolution. Representatives of Euperipatoides rowelli were stained with osmium tetroxide (vapour or solution), ruthenium red, phosphotungstic acid, or iodine. Unstained specimens were imaged using both standard attenuation-based and differential phase-contrast setups to simulate analyses with museum material. Our comparative qualitative analyses of several tissue types demonstrate that osmium tetroxide provides the best overall tissue contrast in onychophorans, whereas the remaining staining agents rather favour the visualisation of specific tissues and/or structures. Quantitative analyses using signal-to-noise ratio measurements show that the level of image noise may vary according to the staining agent and scanning medium selected. Furthermore, box-and-whisker plots revealed substantial overlap in grey values among structures in all datasets, suggesting that a combination of semiautomatic and manual segmentation of structures is required for comprehensive 3D reconstructions of Onychophora, irrespective of the approach selected. Our results show that X-ray micro-computed tomography is a promising technique for studying onychophorans and, despite the benefits and disadvantages of different staining agents for specific tissues/structures, this method retrieves informative data that may eventually help address evolutionary questions long associated with Onychophora.
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Affiliation(s)
- Henry Jahn
- Department of Zoology, Institute of Biology, University of Kassel, Kassel, Germany
| | - Ivo DE Sena Oliveira
- Department of Zoology, Institute of Biology, University of Kassel, Kassel, Germany.,Departamento de Zoologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Vladimir Gross
- Department of Zoology, Institute of Biology, University of Kassel, Kassel, Germany
| | - Christine Martin
- Department of Zoology, Institute of Biology, University of Kassel, Kassel, Germany
| | - Alexander Hipp
- Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Geesthacht, Germany
| | - Georg Mayer
- Department of Zoology, Institute of Biology, University of Kassel, Kassel, Germany
| | - Jörg U Hammel
- Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Geesthacht, Germany.,Institut für Spezielle Zoologie und Evolutionsbiologie mit Phyletischem Museum, Friedrich-Schiller-University of Jena, Jena, Germany
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17
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Inokuchi JI, Inamori KI, Kabayama K, Nagafuku M, Uemura S, Go S, Suzuki A, Ohno I, Kanoh H, Shishido F. Biology of GM3 Ganglioside. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2018; 156:151-195. [PMID: 29747813 DOI: 10.1016/bs.pmbts.2017.10.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Since the successful molecular cloning in 1998 of GM3 synthase (GM3S, ST3GAL5), the enzyme responsible for initiating biosynthesis of all complex gangliosides, the efforts of our research group have been focused on clarifying the physiological and pathological implications of gangliosides, particularly GM3. We have identified isoforms of GM3S proteins having distinctive lengths of N-terminal cytoplasmic tails, and found that these cytoplasmic tails define subcellular localization, stability, and in vivo activity of GM3S isoforms. Our studies of the molecular pathogenesis of type 2 diabetes, focused on interaction between insulin receptor and GM3 in membrane microdomains, led to a novel concept: type 2 diabetes and certain other lifestyle-related diseases are membrane microdomain disorders resulting from aberrant expression of gangliosides. This concept has enhanced our understanding of the pathophysiological roles of GM3 and related gangliosides in various diseases involving chronic inflammation, such as insulin resistance, leptin resistance, and T-cell function and immune disorders (e.g., allergic asthma). We also demonstrated an essential role of GM3 in murine and human auditory systems; a common pathological feature of GM3S deficiency is deafness. This is the first direct link reported between gangliosides and auditory functions.
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Affiliation(s)
- Jin-Ichi Inokuchi
- Institute of Molecular Biomembrane and Glycobiology, Tohoku Medical and Pharmaceutical University, Sendai, Miyagi, Japan.
| | - Kei-Ichiro Inamori
- Institute of Molecular Biomembrane and Glycobiology, Tohoku Medical and Pharmaceutical University, Sendai, Miyagi, Japan
| | | | - Masakazu Nagafuku
- Institute of Molecular Biomembrane and Glycobiology, Tohoku Medical and Pharmaceutical University, Sendai, Miyagi, Japan
| | - Satoshi Uemura
- Tohoku Medical and Pharmaceutical University, Sendai, Miyagi, Japan
| | - Shinji Go
- Institute of Molecular Biomembrane and Glycobiology, Tohoku Medical and Pharmaceutical University, Sendai, Miyagi, Japan
| | - Akemi Suzuki
- Institute of Molecular Biomembrane and Glycobiology, Tohoku Medical and Pharmaceutical University, Sendai, Miyagi, Japan
| | - Isao Ohno
- Center for Medical Education, Tohoku Medical and Pharmaceutical University, Sendai, Miyagi, Japan
| | - Hirotaka Kanoh
- Institute of Molecular Biomembrane and Glycobiology, Tohoku Medical and Pharmaceutical University, Sendai, Miyagi, Japan
| | - Fumi Shishido
- Institute of Molecular Biomembrane and Glycobiology, Tohoku Medical and Pharmaceutical University, Sendai, Miyagi, Japan
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18
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Gangliosides and hearing. Biochim Biophys Acta Gen Subj 2017; 1861:2485-2493. [PMID: 28571946 DOI: 10.1016/j.bbagen.2017.05.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 05/25/2017] [Accepted: 05/25/2017] [Indexed: 01/12/2023]
Abstract
Severe auditory impairment observed in GM3 synthase-deficient mice and humans indicates that glycosphingolipids, especially sialic-acid containing gangliosides, are indispensable for hearing. Gangliosides associate with glycoproteins to form membrane microdomains, the composition of which plays a special role in maintaining the structural and functional integrity of hair cells. These microdomains, also called lipid rafts, connect with intracellular signaling and cytoskeletal systems to link cellular responses to environmental cues. During development, ganglioside species are expressed in distinctive spatial and temporal patterns throughout the cochlea. In both mice and humans, blocking particular steps of ganglioside metabolism produces distinctive neurological and auditory phenotypes. Thus each ganglioside species may have specific, non-overlapping functions within the cochlea, central auditory network, and brain.
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Claassen H, Schicht M, Fleiner B, Hillmann R, Hoogeboom S, Tillmann B, Paulsen F. Different Patterns of Cartilage Mineralization Analyzed by Comparison of Human, Porcine, and Bovine Laryngeal Cartilages. J Histochem Cytochem 2017; 65:367-379. [PMID: 28388264 DOI: 10.1369/0022155417703025] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Laryngeal cartilages undergo a slow ossification process during aging, making them an excellent model for studying cartilage mineralization and ossification processes. Pig laryngeal cartilages are similar to their human counterparts in shape and size, also undergo mineralization, facilitating the study of cartilage mineralization. We investigated the processes of cartilage mineralization and ossification and compared these with the known processes in growth plates. Thyroid cartilages from glutaraldehyde-perfused male minipigs and from domestic pigs were used for X-ray, light microscopic, and transmission electron microscopic analyses. We applied different fixation and postfixation solutions to preserve cell shape, proteoglycans, and membranes. In contrast to the ossifying human thyroid cartilage, predominantly cartilage mineralization was observed in minipig and domestic pig thyroid cartilages. The same subset of chondrocytes responsible for growth plate mineralization is also present in thyroid cartilage mineralization. Besides mineralization mediated by matrix vesicles, a second pattern of cartilage mineralization was observed in thyroid cartilage only. Here, the formation and growth of crystals were closely related to collagen fibrils, which served as guide rails for the expansion of mineralization. It is hypothesized that the second pattern of cartilage mineralization may be similar to a maturation of mineralized cartilage after initial matrix vesicles-mediated cartilage mineralization.
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Affiliation(s)
- Horst Claassen
- Institute of Anatomy and Cell Biology, Martin-Luther-University Halle-Wittenberg (MLU), Halle, Germany (HC).,Institute of Anatomy (HC, RH, BT) and Department of Oral and Maxillofacial Surgery (BF), Kiel, Germany
| | - Martin Schicht
- Institute of Anatomy 2, Friedrich-Alexander-University (FAU) Erlangen-Nürnberg, Erlangen, Germany (MS, SH, FP)
| | - Bernd Fleiner
- Institute of Anatomy (HC, RH, BT) and Department of Oral and Maxillofacial Surgery (BF), Kiel, Germany
| | - Ralf Hillmann
- Institute of Anatomy (HC, RH, BT) and Department of Oral and Maxillofacial Surgery (BF), Kiel, Germany
| | - Sebastian Hoogeboom
- Institute of Anatomy 2, Friedrich-Alexander-University (FAU) Erlangen-Nürnberg, Erlangen, Germany (MS, SH, FP)
| | - Bernhard Tillmann
- Institute of Anatomy (HC, RH, BT) and Department of Oral and Maxillofacial Surgery (BF), Kiel, Germany
| | - Friedrich Paulsen
- Institute of Anatomy 2, Friedrich-Alexander-University (FAU) Erlangen-Nürnberg, Erlangen, Germany (MS, SH, FP)
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20
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Shamir ER, Coutinho K, Georgess D, Auer M, Ewald AJ. Twist1-positive epithelial cells retain adhesive and proliferative capacity throughout dissemination. Biol Open 2016; 5:1216-28. [PMID: 27402962 PMCID: PMC5051642 DOI: 10.1242/bio.019703] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Dissemination is the process by which cells detach and migrate away from a multicellular tissue. The epithelial-to-mesenchymal transition (EMT) conceptualizes dissemination in a stepwise fashion, with downregulation of E-cadherin leading to loss of intercellular junctions, induction of motility, and then escape from the epithelium. This gain of migratory activity is proposed to be mutually exclusive with proliferation. We previously developed a dissemination assay based on inducible expression of the transcription factor Twist1 and here utilize it to characterize the timing and dynamics of intercellular adhesion, proliferation and migration during dissemination. Surprisingly, Twist1(+) epithelium displayed extensive intercellular junctions, and Twist1(-) luminal epithelial cells could still adhere to disseminating Twist1(+) cells. Although proteolysis and proliferation were both observed throughout dissemination, neither was absolutely required. Finally, Twist1(+) cells exhibited a hybrid migration mode; their morphology and nuclear deformation were characteristic of amoeboid cells, whereas their dynamic protrusive activity, pericellular proteolysis and migration speeds were more typical of mesenchymal cells. Our data reveal that epithelial cells can disseminate while retaining competence to adhere and proliferate.
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Affiliation(s)
- Eliah R Shamir
- Departments of Cell Biology and Oncology, Center for Cell Dynamics, Johns Hopkins University School of Medicine, 855 N. Wolfe St, Baltimore, MD 21205, USA
| | - Kester Coutinho
- Departments of Cell Biology and Oncology, Center for Cell Dynamics, Johns Hopkins University School of Medicine, 855 N. Wolfe St, Baltimore, MD 21205, USA Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, MS Donner, Berkeley, CA 94720, USA
| | - Dan Georgess
- Departments of Cell Biology and Oncology, Center for Cell Dynamics, Johns Hopkins University School of Medicine, 855 N. Wolfe St, Baltimore, MD 21205, USA
| | - Manfred Auer
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, MS Donner, Berkeley, CA 94720, USA
| | - Andrew J Ewald
- Departments of Cell Biology and Oncology, Center for Cell Dynamics, Johns Hopkins University School of Medicine, 855 N. Wolfe St, Baltimore, MD 21205, USA
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21
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Denninger AR, Breglio A, Maheras KJ, LeDuc G, Cristiglio V, Demé B, Gow A, Kirschner DA. Claudin-11 Tight Junctions in Myelin Are a Barrier to Diffusion and Lack Strong Adhesive Properties. Biophys J 2016; 109:1387-97. [PMID: 26445439 DOI: 10.1016/j.bpj.2015.08.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 07/20/2015] [Accepted: 08/11/2015] [Indexed: 10/23/2022] Open
Abstract
The radial component is a network of interlamellar tight junctions (TJs) unique to central nervous system myelin. Ablation of claudin-11, a TJ protein, results in the absence of the radial component and compromises the passive electrical properties of myelin. Although TJs are known to regulate paracellular diffusion, this barrier function has not been directly demonstrated for the radial component, and some evidence suggests that the radial component may also mediate adhesion between myelin membranes. To investigate the physical properties of claudin-11 TJs, we compared fresh, unfixed Claudin 11-null and control nerves using x-ray and neutron diffraction. In Claudin 11-null tissue, we detected no changes in myelin structure, stability, or membrane interactions, which argues against the notion that myelin TJs exhibit significant adhesive properties. Moreover, our osmotic stressing and D2O-H2O exchange experiments demonstrate that myelin lacking claudin-11 is more permeable to water and small osmolytes. Thus, our data indicate that the radial component serves primarily as a diffusion barrier and elucidate the mechanism by which TJs govern myelin function.
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Affiliation(s)
| | - Andrew Breglio
- Biology Department, Boston College, Chestnut Hill, Massachusetts
| | - Kathleen J Maheras
- Department of Neurology, Wayne State University School of Medicine, Detroit, Michigan
| | | | | | - Bruno Demé
- Institut Laue-Langevin, Grenoble, France
| | - Alexander Gow
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, Michigan; Carman and Ann Adams Department of Pediatrics, Wayne State University School of Medicine, Detroit, Michigan; Department of Neurology, Wayne State University School of Medicine, Detroit, Michigan
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22
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Enders GC, Friend DS. Detection of anionic sites on the cytoplasmic surface of the guinea pig acrosomal membrane. ACTA ACUST UNITED AC 2016; 173:241-56. [PMID: 20726123 DOI: 10.1002/aja.1001730402] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The sperm acrosome reaction is an example of exocytosis, accomplished through the fusion of the acrosomal and plasma membranes. As in other examples of exocytosis, the acrosome reaction is initiated by an influx of Ca++, which may promote fusion by binding to anionic sites on adjacent bilayers. In this study we used ruthenium red (RR) and cationic ferritin (CF) to detect anionic sites on the surfaces of acrosomal and plasma membranes of guinea pig spermatozoa. These probes indicate a dense concentration of anionic sites on the cytoplasmic surface of the acrosomal membrane. Higher concentrations of salt (NaCl) were required to inhibit cationic probe labeling of the cytoplasmic surface of the acrosomal membrane compared to the concentration needed to inhibit the plasma membrane binding. The added NaCl also increased the separation of the plasma from the acrosomal membrane. Low-pH buffers stop cationic probe labeling of both membranes. Sections tangential to the acrosomal membrane revealed that the cation probes bound in a linear pattern, similar to the periodicity and distribution of intramembraneous particles observed in freeze-fracture replicas. Following fusion of the plasma and acrosomal membrane during the acrosome reaction, we could no longer detect a dense concentration of anionic sites on the cytoplasmic surface of the fused vesicles. The results indicate that the dense concentrations of anionic sites are either masked or lost following fusion with the overlying plasma membrane.
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23
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Yoshikawa M, Go S, Suzuki SI, Suzuki A, Katori Y, Morlet T, Gottlieb SM, Fujiwara M, Iwasaki K, Strauss KA, Inokuchi JI. Ganglioside GM3 is essential for the structural integrity and function of cochlear hair cells. Hum Mol Genet 2015; 24:2796-807. [PMID: 25652401 DOI: 10.1093/hmg/ddv041] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 02/02/2015] [Indexed: 01/18/2023] Open
Abstract
GM3 synthase (ST3GAL5) is the first biosynthetic enzyme of a- and b-series gangliosides. Patients with GM3 synthase deficiency suffer severe neurological disability and deafness. Eight children (ages 4.1 ± 2.3 years) homozygous for ST3GAL5 c.694C>T had no detectable GM3 (a-series) or GD3 (b-series) in plasma. Their auditory function was characterized by the absence of middle ear muscle reflexes, distortion product otoacoustic emissions and cochlear microphonics, as well as abnormal auditory brainstem responses and cortical auditory-evoked potentials. In St3gal5(-/-) mice, stereocilia of outer hair cells showed signs of degeneration as early as postnatal Day 3 (P3); thereafter, blebs devoid of actin or tubulin appeared at the region of vestigial kinocilia, suggesting impaired vesicular trafficking. Stereocilia of St3gal5(-/-) inner hair cells were fused by P17, and protein tyrosine phosphatase receptor Q, normally linked to myosin VI at the tapered base of stereocilia, was maldistributed along the cell membrane. B4galnt1(-/-) (GM2 synthase-deficient) mice expressing only GM3 and GD3 gangliosides had normal auditory structure and function. Thus, GM3-dependent membrane microdomains might be essential for the proper organization and maintenance of stereocilia in auditory hair cells.
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Affiliation(s)
- Misato Yoshikawa
- Division of Glycopathology, Institute of Molecular Biomembranes and Glycobiology, Tohoku Pharmaceutical University, 4-4-1 Aoba-ku, Sendai, Miyagi 981-8558, Japan, Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka 814-0180, Japan
| | - Shinji Go
- Division of Glycopathology, Institute of Molecular Biomembranes and Glycobiology, Tohoku Pharmaceutical University, 4-4-1 Aoba-ku, Sendai, Miyagi 981-8558, Japan
| | - Shun-ichi Suzuki
- Division of Glycopathology, Institute of Molecular Biomembranes and Glycobiology, Tohoku Pharmaceutical University, 4-4-1 Aoba-ku, Sendai, Miyagi 981-8558, Japan
| | - Akemi Suzuki
- Institute of Glycoscience, Tokai University, Kanagawa 259-1292, Japan
| | - Yukio Katori
- Department of Otorhinolaryngology, Head and Neck Surgery, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, SendaiCity, Miyagi 980-8574, Japan
| | - Thierry Morlet
- Department of Biomedical Research, Nemours, Wilmington, DE 19803, USA
| | - Steven M Gottlieb
- Division of Pediatric Neurology, Nemours Alfred I. DuPont Hospital for Children, Wilimington, DE 19803, USA
| | - Michihiro Fujiwara
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka 814-0180, Japan
| | - Katsunori Iwasaki
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka 814-0180, Japan
| | - Kevin A Strauss
- Clinic for Special Children, Strasburg, PA 17579, USA, Biological Foundations of Behavior Program, Franklin and Marshall College, Lancaster, PA 17602, USA and Lancaster General Hospital, Lancaster, PA 17602, USA
| | - Jin-ichi Inokuchi
- Division of Glycopathology, Institute of Molecular Biomembranes and Glycobiology, Tohoku Pharmaceutical University, 4-4-1 Aoba-ku, Sendai, Miyagi 981-8558, Japan,
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24
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Gillies AR, Bushong EA, Deerinck TJ, Ellisman MH, Lieber RL. Three-dimensional reconstruction of skeletal muscle extracellular matrix ultrastructure. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2014; 20:1835-40. [PMID: 25275291 PMCID: PMC4267978 DOI: 10.1017/s1431927614013300] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The skeletal muscle extracellular matrix (ECM) supports muscle's passive mechanical function and provides a unique environment for extracellular tissues such as nerves, blood vessels, and a cadre of mononuclear cells. Within muscle ECM, collagen is thought to be the primary load-bearing protein, yet its structure and organization with respect to muscle fibers, tendon, and mononuclear cells is unknown. Detailed examination of extracellular collagen morphology requires high-resolution electron microscopy performed over relatively long distances because multinucleated muscle cells are very long and extend from several millimeters to several centimeters. Unfortunately, there is no tool currently available for high resolution ECM analysis that extends over such distances relevant to muscle fibers. Serial block face scanning electron microscopy is reported here to examine skeletal muscle ECM ultrastructure over hundreds of microns. Ruthenium red staining was implemented to enhance contrast and utilization of variable pressure imaging reduced electron charging artifacts, allowing continuous imaging over a large ECM volume. This approach revealed previously unappreciated perimysial collagen structures that were reconstructed via both manual and semi-automated segmentation methods. Perimysial collagen structures in the ECM may provide a target for clinical therapies aimed at reducing skeletal muscle fibrosis and stiffness.
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Affiliation(s)
- Allison R Gillies
- 1Department of Bioengineering,University of California San Diego,9500 Gilman Drive,La Jolla,CA,92093-0863,USA
| | - Eric A Bushong
- 2National Center for Microscopy and Imaging Research,University of California San Diego,9500 Gilman Drive,La Jolla,CA,92093-0608,USA
| | - Thomas J Deerinck
- 2National Center for Microscopy and Imaging Research,University of California San Diego,9500 Gilman Drive,La Jolla,CA,92093-0608,USA
| | - Mark H Ellisman
- 2National Center for Microscopy and Imaging Research,University of California San Diego,9500 Gilman Drive,La Jolla,CA,92093-0608,USA
| | - Richard L Lieber
- 1Department of Bioengineering,University of California San Diego,9500 Gilman Drive,La Jolla,CA,92093-0863,USA
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25
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Hunziker EB, Lippuner K, Shintani N. How best to preserve and reveal the structural intricacies of cartilaginous tissue. Matrix Biol 2014; 39:33-43. [PMID: 25173436 DOI: 10.1016/j.matbio.2014.08.010] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
No single processing technique is capable of optimally preserving each and all of the structural entities of cartilaginous tissue. Hence, the choice of methodology must necessarily be governed by the nature of the component that is targeted for analysis, for example, fibrillar collagens or proteoglycans within the extracellular matrix, or the chondrocytes themselves. This article affords an insight into the pitfalls that are to be encountered when implementing the available techniques and how best to circumvent them. Adult articular cartilage is taken as a representative pars pro toto of the different bodily types. In mammals, this layer of tissue is a component of the synovial joints, wherein it fulfills crucial and diverse biomechanical functions. The biomechanical functions of articular cartilage have their structural and molecular correlates. During the natural course of postnatal development and after the onset of pathological disease processes, such as osteoarthritis, the tissue undergoes structural changes which are intimately reflected in biomechanical modulations. The fine structural intricacies that subserve the changes in tissue function can be accurately assessed only if they are faithfully preserved at the molecular level. For this reason, a careful consideration of the tissue-processing technique is indispensable. Since, as aforementioned, no single methodological tool is capable of optimally preserving all constituents, the approach must be pre-selected with a targeted structure in view. Guidance in this choice is offered.
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Affiliation(s)
- Ernst B Hunziker
- Departments of Osteoporosis, Orthopaedic Surgery and Clinical Research, Inselspital, University of Bern, Murtenstrasse 35, P.O. Box 54, 3010 Bern, Switzerland.
| | - Kurt Lippuner
- Departments of Osteoporosis, Orthopaedic Surgery and Clinical Research, Inselspital, University of Bern, Murtenstrasse 35, P.O. Box 54, 3010 Bern, Switzerland
| | - Nahoko Shintani
- Departments of Osteoporosis, Orthopaedic Surgery and Clinical Research, Inselspital, University of Bern, Murtenstrasse 35, P.O. Box 54, 3010 Bern, Switzerland
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26
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Solomonov I, Talmi-Frank D, Milstein Y, Addadi S, Aloshin A, Sagi I. Introduction of correlative light and airSEM™ microscopy imaging for tissue research under ambient conditions. Sci Rep 2014; 4:5987. [PMID: 25100357 PMCID: PMC5154511 DOI: 10.1038/srep05987] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Accepted: 07/22/2014] [Indexed: 11/09/2022] Open
Abstract
A complete fingerprint of a tissue sample requires a detailed description of its cellular and extracellular components while minimizing artifacts. We introduce the application of a novel scanning electron microscope (airSEM™) in conjunction with light microscopy for functional analysis of tissue preparations at nanometric resolution (<10 nm) and under ambient conditions. Our metal-staining protocols enable easy and detailed visualization of tissues and their extracellular scaffolds. A multimodality imaging setup, featuring airSEM™ and a light microscope on the same platform, provides a convenient and easy-to-use system for obtaining structural and functional correlative data. The airSEM™ imaging station complements other existing imaging solutions and shows great potential for studies of complex biological systems.
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Affiliation(s)
- Inna Solomonov
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot 76100, Israel
- These authors contributed equally to this work
| | - Dalit Talmi-Frank
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot 76100, Israel
- These authors contributed equally to this work
| | | | | | - Anna Aloshin
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Irit Sagi
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot 76100, Israel
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Quagio-Grassiotto I, Wildner DD, Guimarães-Bassoli ACD. A cytochemical approach to describe oocyte development in the freshwater ostariophysan, Serrasalmus maculatus (Characiformes). Micron 2014; 60:18-28. [DOI: 10.1016/j.micron.2014.01.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 12/17/2013] [Accepted: 01/05/2014] [Indexed: 12/15/2022]
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Bubencíkova T, Cholujová D, Messingerová L, Mislovicova D, Seres M, Breier A, Sulova Z. Detection of glycomic alterations induced by overexpression of p-glycoprotein on the surfaces of L1210 cells using sialic acid binding lectins. Int J Mol Sci 2012. [PMID: 23203118 PMCID: PMC3509634 DOI: 10.3390/ijms131115177] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
P-glycoprotein (P-gp) overexpression is the most frequently observed cause of multidrug resistance in neoplastic cells. In our experiments, P-gp was expressed in L1210 mice leukemia cells (S cells) by selection with vincristine (R cells) or transfection with the gene encoding human P-gp (T cells). Remodeling of cell surface sugars is associated with P-gp expression in L1210 cells as a secondary cellular response. In this study, we monitored the alteration of cell surface saccharides by Sambucus nigra agglutinin (SNA), wheat germ agglutinin (WGA) and Maackia amurensis agglutinin (MAA). Sialic acid is predominantly linked to the surface of S, R and T cells via α-2,6 branched sugars that tightly bind SNA. The presence of sialic acid linked to the cell surface via α-2,3 branched sugars was negligible, and the binding of MAA (recognizing this branch) was much less pronounced than SNA. WGA induced greater cell death than SNA, which was bound to the cell surface and agglutinated all three L1210 cell-variants more effectively than WGA. Thus, the ability of lectins to induce cell death did not correlate with their binding efficiency and agglutination potency. Compared to S cells, P-gp positive R and T cells contain a higher amount of N-acetyl-glucosamine on their cell surface, which is associated with improved WGA binding. Both P-gp positive variants of L1210 cells are strongly resistant to vincristine as P-gp prototypical drug. This resistance could not be altered by liberalization of terminal sialyl residues from the cell surface by sialidase.
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Affiliation(s)
- Tatiana Bubencíkova
- Institute of Molecular Physiology and Genetics, Center of Excellence of the Slovak Research and Development Agency “BIOMEMBRANES2008”, Slovak Academy of Sciences, Vlarska 5, Bratislava 83334, Slovakia; E-Mails: (T.B.); (L.M.); (M.S.)
| | - Dana Cholujová
- Cancer Research Institute, Slovak Academy of Sciences, Vlarska 7, Bratislava 83391, Slovakia; E-Mail:dana.cholujova @savba.sk
| | - Lucia Messingerová
- Institute of Molecular Physiology and Genetics, Center of Excellence of the Slovak Research and Development Agency “BIOMEMBRANES2008”, Slovak Academy of Sciences, Vlarska 5, Bratislava 83334, Slovakia; E-Mails: (T.B.); (L.M.); (M.S.)
| | - Danica Mislovicova
- Institute of Chemistry, Slovak Academy of Sciences, Dubravska cesta 9, Bratislava 84538, Slovakia; E-Mail:
| | - Mario Seres
- Institute of Molecular Physiology and Genetics, Center of Excellence of the Slovak Research and Development Agency “BIOMEMBRANES2008”, Slovak Academy of Sciences, Vlarska 5, Bratislava 83334, Slovakia; E-Mails: (T.B.); (L.M.); (M.S.)
| | - Albert Breier
- Institute of Molecular Physiology and Genetics, Center of Excellence of the Slovak Research and Development Agency “BIOMEMBRANES2008”, Slovak Academy of Sciences, Vlarska 5, Bratislava 83334, Slovakia; E-Mails: (T.B.); (L.M.); (M.S.)
- Authors to whom correspondence should be addressed: E-Mails: (A.B.); (Z.S.); Tel.: +421-903-472606 (A.B.); +421-903-246360 (Z.S.); Fax: +421-2-54773666 (A.B.); +421-2-54773666 (Z.S.)
| | - Zdena Sulova
- Institute of Molecular Physiology and Genetics, Center of Excellence of the Slovak Research and Development Agency “BIOMEMBRANES2008”, Slovak Academy of Sciences, Vlarska 5, Bratislava 83334, Slovakia; E-Mails: (T.B.); (L.M.); (M.S.)
- Authors to whom correspondence should be addressed: E-Mails: (A.B.); (Z.S.); Tel.: +421-903-472606 (A.B.); +421-903-246360 (Z.S.); Fax: +421-2-54773666 (A.B.); +421-2-54773666 (Z.S.)
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Paes-de-Oliveira VT, Roat TC, Berger B, Da Cruz-Landim C. Cytochemistry of fat body trophocytes and ovaries of workers and queens of Melipona quadrifasciata anthidioides (Hymenoptera: Apidae: Meliponini) during vitellogenesis. Microsc Res Tech 2012; 75:1623-31. [PMID: 22833289 DOI: 10.1002/jemt.22107] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Accepted: 06/28/2012] [Indexed: 11/06/2022]
Abstract
The fat body (FB) of insects is where yolk proteins are synthesized. Therefore, relationships between the FB and oogenesis were studied in nurse workers, virgins, and physogastric queens of Melipona quadrifasciata anthidioides, a stingless bee in which the workers produce and lay eggs while provisioning brood cells. The relationships between FB and oogenesis, as well as the routes of materials from hemolymph to the oocytes, were studied through the cytochemical detection of lipids by osmium imidazole (OI), carbohydrates by ruthenium red (RR) and basic proteins by ammoniacal silver (AS). The results show differences in the presence of the studied materials in FB trophocytes and ovary of the classes of females studied and oogenesis phases. Material that tested positive for the treatments was detected among the classes of individuals studied in both, trophocytes and oocytes, and in the route of those materials from hemolymph to the oocytes. The differences found among the individual classes indicate relationships with the nutrition and adaptation to the parsimonious use of nutrients in the metabolism of reproduction.
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Affiliation(s)
- Vagner Tadeu Paes-de-Oliveira
- Departamento de Biologia, Instituto de Biociências de Rio Claro, UNESP-Univ. Estadual Paulista, Bela Vista, 13.506-900 Rio Claro, SP, Brazil
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Sorokina AY, Chernousova EY, Dubinina GA. Hoeflea siderophila sp. nov., a new neutrophilic iron-oxidizing bacterium. Microbiology (Reading) 2012. [DOI: 10.1134/s0026261712010146] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Cidadāo AJ, David-Ferreira JF. A method for TEM visualization of the extracellular matrix three-dimensional organization in tissues. J Microsc 2011. [DOI: 10.1111/j.1365-2818.1986.tb02736.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Rothe BH, Schmidt-Rhaesa A, Kieneke A. The nervous system of Neodasys chaetonotoideus (Gastrotricha: Neodasys) revealed by combining confocal laserscanning and transmission electron microscopy: evolutionary comparison of neuroanatomy within the Gastrotricha and basal Protostomia. ZOOMORPHOLOGY 2011. [DOI: 10.1007/s00435-011-0123-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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33
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Suzina NE, Esikova TZ, Akimov VN, Abashina TN, Dmitriev VV, Polivtseva VN, Duda VI, Boronin AM. Study of ectoparasitism of ultramicrobacteria of the genus Kaistia, strains NF1 and NF3 by electron and fluorescence microscopy. Microbiology (Reading) 2011. [DOI: 10.1134/s0026261708010074] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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34
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Peachey LD, Franzini‐Armstrong C. Structure and Function of Membrane Systems of Skeletal Muscle Cells. Compr Physiol 2011. [DOI: 10.1002/cphy.cp100102] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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35
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Regal DS. Experimentelle Untersuchungen zur extraossären Verkalkung bei der Hypervitaminose D3. ACTA ACUST UNITED AC 2010. [DOI: 10.1111/j.1439-0442.1982.tb01826.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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36
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Benaroch P, Billard E, Gaudin R, Schindler M, Jouve M. HIV-1 assembly in macrophages. Retrovirology 2010; 7:29. [PMID: 20374631 PMCID: PMC2861634 DOI: 10.1186/1742-4690-7-29] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2009] [Accepted: 04/07/2010] [Indexed: 12/31/2022] Open
Abstract
The molecular mechanisms involved in the assembly of newly synthesized Human Immunodeficiency Virus (HIV) particles are poorly understood. Most of the work on HIV-1 assembly has been performed in T cells in which viral particle budding and assembly take place at the plasma membrane. In contrast, few studies have been performed on macrophages, the other major target of HIV-1. Infected macrophages represent a viral reservoir and probably play a key role in HIV-1 physiopathology. Indeed macrophages retain infectious particles for long periods of time, keeping them protected from anti-viral immune response or drug treatments. Here, we present an overview of what is known about HIV-1 assembly in macrophages as compared to T lymphocytes or cell lines. Early electron microscopy studies suggested that viral assembly takes place at the limiting membrane of an intracellular compartment in macrophages and not at the plasma membrane as in T cells. This was first considered as a late endosomal compartment in which viral budding seems to be similar to the process of vesicle release into multi-vesicular bodies. This view was notably supported by a large body of evidence involving the ESCRT (Endosomal Sorting Complex Required for Transport) machinery in HIV-1 budding, the observation of viral budding profiles in such compartments by immuno-electron microscopy, and the presence of late endosomal markers associated with macrophage-derived virions. However, this model needs to be revisited as recent data indicate that the viral compartment has a neutral pH and can be connected to the plasma membrane via very thin micro-channels. To date, the exact nature and biogenesis of the HIV assembly compartment in macrophages remains elusive. Many cellular proteins potentially involved in the late phases of HIV-1 cycle have been identified; and, recently, the list has grown rapidly with the publication of four independent genome-wide screens. However, their respective roles in infected cells and especially in macrophages remain to be characterized. In summary, the complete process of HIV-1 assembly is still poorly understood and will undoubtedly benefit from the ongoing explosion of new imaging techniques allowing better time-lapse and quantitative studies.
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Affiliation(s)
- Philippe Benaroch
- Institut Curie, Centre de Recherche, Paris, F-75248 France; INSERM U932, Paris, F-75248 France.
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Holman DW, Kurtcuoglu V, Grzybowski DM. Cerebrospinal fluid dynamics in the human cranial subarachnoid space: an overlooked mediator of cerebral disease. II. In vitro arachnoid outflow model. J R Soc Interface 2010; 7:1205-18. [PMID: 20335192 DOI: 10.1098/rsif.2010.0032] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The arachnoid membrane (AM) and granulations (AGs) are important in cerebrospinal fluid (CSF) homeostasis, regulating intracranial pressure in health and disease. We offer a functional perspective of the human AM's transport mechanism to clarify the role of AM in the movement of CSF and metabolites. Using cultures of human AG cells and a specialized perfusion system, we have shown that this in vitro model mimics the in vivo characteristics of unidirectional fluid transport and we present the first report of serum-free permeability values (92.5 microl min(-1) mm Hg(-1) cm(-2)), which in turn are in agreement with the CSF outflow rates derived from a dynamic, in vivo magnetic resonance imaging-based computational model of the subarachnoid cranial space (130.9 microl min(-1) mm Hg(-1) cm(-2)). Lucifer yellow permeability experiments have verified the maintenance of tight junctions by the arachnoidal cells with a peak occurring around 21 days post-seeding, which is when all perfusion experiments were conducted. Addition of ruthenium red to the perfusate, and subsequent analysis of its distribution post-perfusion, has verified the passage of perfusate via both paracellular and transcellular mechanisms with intracellular vacuoles of approximately 1 microm in diameter being the predominant transport mechanism. The comparison of the computational and in vitro models is the first report to measure human CSF dynamics functionally and structurally, enabling the development of innovative approaches to modify CSF outflow and will change concepts and management of neurodegenerative diseases resulting from CSF stagnation.
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Affiliation(s)
- David W Holman
- Biomedical Engineering Department, Ohio State University, 915 Olentangy River Road, Columbus, OH 43212, USA
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Silveira-Lacerda EDP, Vilanova-Costa CAST, Pereira FDC, Hamaguchi A, Pavanin LA, Goulart LR, Homsi-Brandenburgo MI, Soares AM, dos Santos WB, Nomizo A. The ruthenium complex cis-(Dichloro)Tetraammineruthenium(III) chloride presents immune stimulatory activity on human peripheral blood mononuclear cells. Biol Trace Elem Res 2010; 133:270-83. [PMID: 19590831 DOI: 10.1007/s12011-009-8440-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2009] [Accepted: 06/22/2009] [Indexed: 11/28/2022]
Abstract
Ruthenium compounds in general are well suited for medicinal applications. They have been investigated as immunosuppressants, nitric oxide scavengers, antimicrobial agents, and antimalarials. The aim of this study is to evaluate the immunomodulatory activity of cis-(dichloro)tetraammineruthenium(III) chloride (cis-[RuCl(2)(NH(3))(4)]Cl) on human peripheral blood mononuclear cells (PBMC). The cytotoxic studies performed here revealed that the ruthenium(III) complex presents a cytotoxic activity towards normal human PBMC, only at very high concentration. Results also showed that cis-[RuCl(2)(NH(3))(4)]Cl presents a dual role on PBMC stimulating proliferation and interleukin-2 (IL-2) production at low concentration and inducing cytotoxicity, inability to proliferate, and inhibiting IL-2 production at high concentration. The noncytotoxic activity of cis-[RuCl(2)(NH(3))(4)]Cl at low concentration towards PBMC, which correlates with the small number of annexin V positive cells and also the absence of DNA fragmentation, suggest that this compound does not induce apoptosis on PBMC. For the first time, we show that, at low concentration (10-100 microg L(-1)), the cis-[RuCl(2)(NH(3))(4)]Cl compound induces peripheral blood lymphocytes proliferation and also stimulates them to IL-2 production. These results open a new potential applicability of ruthenium(III) complexes as a possible immune regulatory compound acting as immune suppressor at high concentration and as immune stimulator at low concentration.
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Affiliation(s)
- Elisângela de Paula Silveira-Lacerda
- Laboratório de Genética Molecular e Citogenética, Instituto de Ciências Biológicas (ICB I), Universidade Federal de Goiás, Sala 200, Campus Samambaia (Campus II), Cx. Postal: 131, Goiânia, Goiás, Brazil.
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Kurth T, Berger J, Wilsch-Bräuninger M, Kretschmar S, Cerny R, Schwarz H, Löfberg J, Piendl T, Epperlein HH. Electron Microscopy of the Amphibian Model Systems Xenopus laevis and Ambystoma mexicanum. Methods Cell Biol 2010; 96:395-423. [DOI: 10.1016/s0091-679x(10)96017-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Abstract
For almost 100 years, insects have been favorable "model systems" in biology. Just to mention a few examples: fruit flies in genetics and developmental biology; bugs and caterpillars in hormone research; houseflies, blowflies, and locusts in neurobiology; silk moths in pheromone research; honeybees and crickets in neuroethology. For more than 50 years the electron microscope (EM) has been a valuable tool in analyzing the structure of cells and organs of these creatures. However, progress in specimen preparation was relatively slow compared with mammalian material and, in 1970, it was taken for granted that insects were much more difficult to fix than mammals. Since then, methods have dramatically improved, and satisfactory results can now be obtained routinely with chemical as well as cryofixation. In this chapter we briefly demonstrate what can be achieved with insect material, and help the researcher to find the most appropriate method for her/his systems and scientific questions.
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Affiliation(s)
- Thomas A Keil
- Department Molecular Structural Biology, Max-Planck-Institute for Biochemistry, D-82152 Martinsried, Germany
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Ormiston ML, Slaughter GRD, Deng Y, Stewart DJ, Courtman DW. The enzymatic degradation of hyaluronan is associated with disease progression in experimental pulmonary hypertension. Am J Physiol Lung Cell Mol Physiol 2009; 298:L148-57. [PMID: 19915162 DOI: 10.1152/ajplung.00097.2009] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hyaluronan (HA) degradation fragments have been linked to inflammation in a wide range of lung diseases. In idiopathic pulmonary arterial hypertension, HA accumulation has been associated with advanced disease. In this study, we investigated the potential role of HA degradation in the early stages of disease by examining HA distribution, molecular mass, synthesis, and enzymatic degradation at different stages of disease progression in a rat model of monocrotaline (MCT)-induced pulmonary hypertension (PH). At 28 days post-MCT, severe PH was associated with increased total lung HA (P = 0.04). In contrast, a significant decrease in total lung HA was observed on day 10, before the onset of PH (P = 0.02). Molecular mass analysis revealed a loss of high molecular mass (HMM) HA at 10 and 24 days post-MCT, followed by an increase in HMM HA at 28 days. Expression of HA synthase 2 (HAS2) was elevated in MCT-challenged animals at 24 and 28 days, consistent with increased synthesis of HMM HA. Analysis by Morgan Elson assay and zymography demonstrated increased hyaluronidase-1 activity in the lungs of MCT-challenged rats, indicating that the observed increases in HAS2 expression and HA synthesis were counterbalanced, in part, by enhanced degradation. The present data demonstrate that, in the MCT model, early-stage PH is associated with enhanced hyaluronidase-1 activity, while both degradation and synthesis are increased at later stages. Thus an early increase in the generation of proinflammatory HA fragments may play a role in the onset and progression of pulmonary arterial hypertension.
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Affiliation(s)
- Mark L Ormiston
- Terrence Donnelly Cardiovascular Research Laboratories, Rm. 8-038, Queen Wing, St. Michael's Hospital, 30 Bond St., Toronto, Ontario, M5B 1W8 Canada
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Zylberberg L, Meunier FJ. Evidence of denticles and attachment fibres in the superficial layer of scales in two fishes: Carassius auratus and Cyprinus carpio (Cyprinidae, Teleostei). J Zool (1987) 2009. [DOI: 10.1111/j.1469-7998.1981.tb03478.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Proposal of Spirillum winogradskyi sp. nov., a novel microaerophilic species, an emended description of the genus Spirillum and Request for an Opinion regarding the status of the species Spirillum volutans Ehrenberg 1832. Int J Syst Evol Microbiol 2009; 59:2916-20. [DOI: 10.1099/ijs.0.009605-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Góes RM, Nader HB, Porcionatto MA, Haddad A, Laicine EM. Chondroitin Sulfate Proteoglycans Are Structural Renewable Constituents of the Rabbit Vitreous Body. Curr Eye Res 2009; 30:405-13. [PMID: 16020271 DOI: 10.1080/02713680590934148] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
PURPOSE To characterize the vitreous intrinsic proteoglycans, investigate their dynamics, and examine their role in the supramolecular organization of the vitreous. METHODS Vitreous from normal rabbits was collected and processed for observation with the transmission electron microscope after treatment with glycosidases. Also, rabbits were injected intravitreally with [35S]-sodium sulfate and sacrificed at several time intervals after the injection. Proteoglycans (PGs) were assayed in the vitreous supernatant or in whole samples extracted with guanidine hydrochloride by polyacrylamide or agarose gel electrophoresis, followed respectively by fluorography or autoradiography, and ion-exchange chromatography and gel-filtration chromatography, combined with glycolytic treatment of the samples. The sulfated glycosaminoglycans (GAGs) were characterized by agarose gel electrophoresis after treating vitreous samples with protease and specific glycosidases. RESULTS The electron microscopic study revealed a network with hyaluronic acid (HA) as thin threads coating and connecting collagen fibrils. The elimination of the HA coat showed chondroitin sulfate granules (8-25 nm) arranged at regular intervals on the fibril surface. The chondroitinase ABC digestion, besides removing the granules, also caused the formation of thicker bundles of the collagen fibrils. The PG and GAG analysis indicated that there are three renewable PGs in the vitreous (e.g., one heparan- and two chondroitin-sulfate ones). CONCLUSIONS At least one of the chondroitin sulfate PGs is involved in the interactions that occur in the vitreous structure, mainly by providing adequate spacing between the collagen fibrils, a condition that is probably required for the transparency of the vitreous.
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Affiliation(s)
- Rejane M Góes
- Departamento de Biologia, UNESP, São José do Rio Preto, Brazil
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Abstract
Scanning electron microscopy of human cadaver corneas revealed a selective binding of ruthenium red-osmium tetroxide to some substance coating the posterior endothelial surface. A coating material was not found on autolyzed cells, on denuded areas of the membrane of Descemet, or on the anterior surface of endothelial cells. Partial digestion of the coating material by urokinase and trypsin suggests the presence of at least three different structural or chemical elements.
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Handley KM, Turner SJ, Campbell KA, Mountain BW. Silicifying biofilm exopolymers on a hot-spring microstromatolite: templating nanometer-thick laminae. ASTROBIOLOGY 2008; 8:747-770. [PMID: 18781887 DOI: 10.1089/ast.2007.0172] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Exopolymeric substances (EPS) are an integral component of microbial biofilms; however, few studies have addressed their silicification and preservation in hot-spring deposits. Through comparative analyses with the use of a range of microscopy techniques, we identified abundant EPS significant to the textural development of spicular, microstromatolitic, siliceous sinter at Champagne Pool, Waiotapu, New Zealand. Examination of biofilms coating sinter surfaces by confocal laser scanning microscopy (CLSM), environmental scanning electron microscopy (ESEM), cryo-scanning electron microscopy (cryo-SEM), and transmission electron microscopy (TEM) revealed contraction of the gelatinous EPS matrix into films (approximately 10 nm thick) or fibrillar structures, which is common in conventional SEM analyses and analogous to products of naturally occurring desiccation. Silicification of fibrillar EPS contributed to the formation of filamentous sinter. Matrix surfaces or dehydrated films templated sinter laminae (nanometers to microns thick) that, in places, preserved fenestral voids beneath. Laminae of similar thickness are, in general, common to spicular geyserites. This is the first report to demonstrate EPS templation of siliceous stromatolite laminae. Considering the ubiquity of biofilms on surfaces in hot-spring environments, EPS silicification studies are likely to be important to a better understanding of the origins of laminae in other modern and ancient stromatolitic sinters, and EPS potentially may serve as biosignatures in extraterrestrial rocks.
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Affiliation(s)
- Kim M Handley
- School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Manchester, United Kingdom
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Goldman RD, Berg G, Bushnell A, Chang CM, Dickerman L, Hopkins N, Miller ML, Pollack R, Wang E. Fibrillar systems in cell motility. CIBA FOUNDATION SYMPOSIUM 2008; 14:83-107. [PMID: 4130536 DOI: 10.1002/9780470719978.ch5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Karpel RL, Shirley MS, Holt SR. Interaction of the ruthenium red cation with nucleic acid double helices. Biophys Chem 2008; 13:151-65. [PMID: 17000164 DOI: 10.1016/0301-4622(81)80014-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/1980] [Indexed: 11/16/2022]
Abstract
The hexapositive complex cation ruthenium red very effectively stabilizes DNA and RNA double helices against thermal denaturation. In the presence of nucleic acid helices, this symmetric cation acquires an extrinsic CD spectrum near the wavelength of the dye's maximum absorbance. Competition experiments with single-stranded polyd(T) show this induced CD to be the result of selective binding to helical sites. The preferential affinity of ruthenium red for double helical binding sites is so great that it brings about biphasic absorbance- temperature profiles of polyd(A-T) at low [cation]: [polynucleotide phosphate]. The visible CD signal and fraction of helix melting at the upper transition increases with ruthenium red concentration until approximate charge neutrality is reached. These interactions, which have been studied in detail with the poly(U-U) helix as well as polyd(A-T), are likely largely electrostatic, since sufficient [NaCl] eliminates the bipliasic melting of polyd(A-T), renders the ultraviolet absorbance of poly (U) insensitive to ruthenium red, and abolishes the induced CD effects. The bipliasic melting of polyd(A-T) at intermediate [dye] is attributed to saturation of remaining double helical segments by cation migration from newly melted regions- Furthermore, virtually no change was observed in the induced CD upon melting through the first transition, whereas the effect is destroyed upon inciting through the second transition. A quantitative treatment of the data is used to obtain binding site size and association constant for the complex. The induced effect may prove useful in the exploration of exposed nucleic acid helical structure in such complex particles as nucleosomes or ribosomes.
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Affiliation(s)
- R L Karpel
- Department of Chemistry, University of Maryland Baltimore County, Calonsville, Maryland 21228, USA
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Identification of the bacterial symbiont Entotheonella sp. in the mesohyl of the marine sponge Discodermia sp. ISME JOURNAL 2008; 2:335-9. [PMID: 18256706 DOI: 10.1038/ismej.2007.91] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The lithistid sponge Discodermia dissoluta (family Theonellidae), is found in deep-waters throughout the Caribbean sea and is the source of discodermolide, a natural product with potential anticancer properties, and other secondary metabolites. As with other sponges, large numbers of microbes are harbored in the sponge mesohyl. The microbial population of the sponge mesohyl shows an abundance of large filamentous microbes. Fractionation of the dissociated sponge allowed enrichment of this microbe, which was then identified by analysis of the 16S rRNA genes. Its identity was confirmed through the use of fluorescent in situ hybridization. These studies have allowed the identification of this eubacterial microbe as belonging to the genus Entotheonella.
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