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Bitew MA, Gaete PS, Swale C, Maru P, Contreras JE, Saeij JPJ. Two Toxoplasma gondii putative pore-forming proteins, GRA47 and GRA72, influence small molecule permeability of the parasitophorous vacuole. mBio 2024; 15:e0308123. [PMID: 38380952 PMCID: PMC10936148 DOI: 10.1128/mbio.03081-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 02/01/2024] [Indexed: 02/22/2024] Open
Abstract
Toxoplasma gondii, a medically important intracellular parasite, uses GRA proteins secreted from dense granule organelles to mediate nutrient flux across the parasitophorous vacuole membrane (PVM). GRA17 and GRA23 are known pore-forming proteins on the PVM involved in this process, but the roles of additional proteins have remained largely uncharacterized. We recently identified GRA72 as synthetically lethal with GRA17. Deleting GRA72 produced similar phenotypes to Δgra17 parasites, and computational predictions suggested it forms a pore. To understand how GRA72 functions, we performed immunoprecipitation experiments and identified GRA47 as an interactor of GRA72. Deletion of GRA47 resulted in an aberrant "bubble vacuole" morphology with reduced small molecule permeability, mirroring the phenotype observed in GRA17 and GRA72 knockouts. Structural predictions indicated that GRA47 and GRA72 form heptameric and hexameric pores, respectively, with conserved histidine residues lining the pore. Mutational analysis highlighted the critical role of these histidines for protein functionality. Validation through electrophysiology confirmed alterations in membrane conductance, corroborating their pore-forming capabilities. Furthermore, Δgra47 parasites and parasites expressing GRA47 with a histidine mutation had reduced in vitro proliferation and attenuated virulence in mice. Our findings show the important roles of GRA47 and GRA72 in regulating PVM permeability, thereby expanding the repertoire of potential therapeutic targets against Toxoplasma infections. IMPORTANCE Toxoplasma gondii is a parasite that poses significant health risks to those with impaired immunity. It replicates inside host cells shielded by the PVM, which controls nutrient and waste exchange with the host. GRA72, previously identified as essential in the absence of the GRA17 nutrient channel, is implicated in forming an alternative nutrient channel. Here we found that GRA47 associates with GRA72 and is also important for the PVM's permeability to small molecules. Removal of GRA47 leads to distorted vacuoles and impairs small molecule transport across the PVM, resembling the effects of GRA17 and GRA72 deletions. Structural models suggest GRA47 and GRA72 form distinct pore structures, with a pore-lining histidine critical to their function. Toxoplasma strains lacking GRA47 or those with a histidine mutation have impaired growth and reduced virulence in mice, highlighting these proteins as potential targets for new treatments against toxoplasmosis.
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Affiliation(s)
- Mebratu A. Bitew
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, California, USA
| | - Pablo S. Gaete
- Department of Physiology and Membrane Biology, University of California, Davis, California, USA
| | - Christopher Swale
- Team Host-Pathogen Interactions and Immunity to Infection, Institute for Advanced Biosciences (IAB), INSERM U1209, CNRS UMR5309, University Grenoble Alpes, Grenoble, France
| | - Parag Maru
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, California, USA
| | - Jorge E. Contreras
- Department of Physiology and Membrane Biology, University of California, Davis, California, USA
| | - Jeroen P. J. Saeij
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, California, USA
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Son JY, Lee KY, Lee SH, Choi CH. Effects of Oxidized Metal Powders on Pore Defects in Powder-Fed Direct Energy Deposition. Micromachines (Basel) 2024; 15:243. [PMID: 38398972 PMCID: PMC10893081 DOI: 10.3390/mi15020243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 01/29/2024] [Accepted: 01/31/2024] [Indexed: 02/25/2024]
Abstract
Laser-based additive manufacturing processes, particularly direct energy deposition (DED), have gained prominence for fabricating complex, functionally graded, or customized parts. DED employs a high-powered heat source to melt metallic powder or wire, enabling precise control of grain structures and the production of high-strength objects. However, common defects, such as a lack of fusion and pores between layers or beads, can compromise the mechanical properties of the printed components. This study focuses on investigating the recurrent causes of pore defects in the powder-fed DED process, with a specific emphasis on the influence of oxidized metal powders. This research explores the impact of intentionally oxidizing metal powders of hot work tool steel H13 by exposing them to regulated humidity and temperature conditions. Scanning electron microscopy images and energy-dispersive X-ray spectroscopy results demonstrate the clumping of powders and the deposition of iron oxides in the oxidized powders at elevated temperatures (70 °C for 72 h). Multi-layered depositions of the oxidized H13 powders on STD61 substrate do not show significant differences in cross sections among specimens, suggesting that oxidation does not visibly form large pores. However, fine pores, detected through CT scanning, are observed in depositions of oxidized powders at higher temperatures. These fine pores, typically less than 250 µm in diameter, are irregularly distributed throughout the deposition, indicating a potential degradation in mechanical properties. The findings highlight the need for careful consideration of oxidation effects in optimizing process parameters for enhanced additive manufacturing quality.
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Affiliation(s)
- Jong-Youn Son
- Department of Mechanical Engineering, Stevens Institute of Technology, Castle Point on Hudson, Hoboken, NJ 07030, USA;
| | - Ki-Yong Lee
- Automotive Materials & Components R&D Group, Korea Institute of Industrial Technology, 9, Cheomdanventure-ro 108beon-gil, Buk-gu, Gwangju 61007, Republic of Korea;
| | - Seung Hwan Lee
- School of Mechanical Engineering, Hanyang University, 222 Wangsimni-ro, SeongDong-Gu, Seoul 04763, Republic of Korea;
| | - Chang-Hwan Choi
- Department of Mechanical Engineering, Stevens Institute of Technology, Castle Point on Hudson, Hoboken, NJ 07030, USA;
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Lu J, Dreyer I, Dickinson MS, Panzer S, Jaślan D, Navarro-Retamal C, Geiger D, Terpitz U, Becker D, Stroud RM, Marten I, Hedrich R. Vicia faba SV channel VfTPC1 is a hyperexcitable variant of plant vacuole Two Pore Channels. eLife 2023; 12:e86384. [PMID: 37991833 PMCID: PMC10665017 DOI: 10.7554/elife.86384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 10/12/2023] [Indexed: 11/23/2023] Open
Abstract
To fire action-potential-like electrical signals, the vacuole membrane requires the two-pore channel TPC1, formerly called SV channel. The TPC1/SV channel functions as a depolarization-stimulated, non-selective cation channel that is inhibited by luminal Ca2+. In our search for species-dependent functional TPC1 channel variants with different luminal Ca2+ sensitivity, we found in total three acidic residues present in Ca2+ sensor sites 2 and 3 of the Ca2+-sensitive AtTPC1 channel from Arabidopsis thaliana that were neutral in its Vicia faba ortholog and also in those of many other Fabaceae. When expressed in the Arabidopsis AtTPC1-loss-of-function background, wild-type VfTPC1 was hypersensitive to vacuole depolarization and only weakly sensitive to blocking luminal Ca2+. When AtTPC1 was mutated for these VfTPC1-homologous polymorphic residues, two neutral substitutions in Ca2+ sensor site 3 alone were already sufficient for the Arabidopsis At-VfTPC1 channel mutant to gain VfTPC1-like voltage and luminal Ca2+ sensitivity that together rendered vacuoles hyperexcitable. Thus, natural TPC1 channel variants exist in plant families which may fine-tune vacuole excitability and adapt it to environmental settings of the particular ecological niche.
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Affiliation(s)
- Jinping Lu
- Julius-Maximilians-Universität (JMU), Biocenter, Department of Molecular Plant Physiology and BiophysicsWürzburgGermany
- School of Life Sciences, Zhengzhou UniversityZhengzhouChina
| | - Ingo Dreyer
- Universidad de Talca, Faculty of Engineering, Center of Bioinformatics, Simulation and ModelingTalcaChile
| | - Miles Sasha Dickinson
- University of California San Francisco, Department of Biochemistry and BiophysicsSan FranciscoUnited States
| | - Sabine Panzer
- Julius-Maximilians-Universität (JMU), Biocenter, Theodor-Boveri-Institute, Department of Biotechnology and BiophysicsWürzburgGermany
| | - Dawid Jaślan
- Julius-Maximilians-Universität (JMU), Biocenter, Department of Molecular Plant Physiology and BiophysicsWürzburgGermany
- Ludwig Maximilians-Universität, Faculty of Medicine, Walther Straub Institute of Pharmacology and ToxicologyMunichGermany
| | - Carlos Navarro-Retamal
- Universidad de Talca, Faculty of Engineering, Center of Bioinformatics, Simulation and ModelingTalcaChile
- Department of Cell Biology and Molecular Genetics, University of MarylandCollege ParkUnited States
| | - Dietmar Geiger
- Julius-Maximilians-Universität (JMU), Biocenter, Department of Molecular Plant Physiology and BiophysicsWürzburgGermany
| | - Ulrich Terpitz
- Julius-Maximilians-Universität (JMU), Biocenter, Theodor-Boveri-Institute, Department of Biotechnology and BiophysicsWürzburgGermany
| | - Dirk Becker
- Julius-Maximilians-Universität (JMU), Biocenter, Department of Molecular Plant Physiology and BiophysicsWürzburgGermany
| | - Robert M Stroud
- University of California San Francisco, Department of Biochemistry and BiophysicsSan FranciscoUnited States
| | - Irene Marten
- Julius-Maximilians-Universität (JMU), Biocenter, Department of Molecular Plant Physiology and BiophysicsWürzburgGermany
| | - Rainer Hedrich
- Julius-Maximilians-Universität (JMU), Biocenter, Department of Molecular Plant Physiology and BiophysicsWürzburgGermany
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Peng Y, Zhuang Y, Liu Y, Le H, Li D, Zhang M, Liu K, Zhang Y, Zuo J, Ding J. Bioinspired gradient scaffolds for osteochondral tissue engineering. Exploration (Beijing) 2023; 3:20210043. [PMID: 37933242 PMCID: PMC10624381 DOI: 10.1002/exp.20210043] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 01/05/2023] [Indexed: 11/08/2023]
Abstract
Repairing articular osteochondral defects present considerable challenges in self-repair due to the complex tissue structure and low proliferation of chondrocytes. Conventional clinical therapies have not shown significant efficacy, including microfracture, autologous/allograft osteochondral transplantation, and cell-based techniques. Therefore, tissue engineering has been widely explored in repairing osteochondral defects by leveraging the natural regenerative potential of biomaterials to control cell functions. However, osteochondral tissue is a gradient structure with a smooth transition from the cartilage to subchondral bone, involving changes in chondrocyte morphologies and phenotypes, extracellular matrix components, collagen type and orientation, and cytokines. Bioinspired scaffolds have been developed by simulating gradient characteristics in heterogeneous tissues, such as the pores, components, and osteochondrogenesis-inducing factors, to satisfy the anisotropic features of osteochondral matrices. Bioinspired gradient scaffolds repair osteochondral defects by altering the microenvironments of cell growth to induce osteochondrogenesis and promote the formation of osteochondral interfaces compared with homogeneous scaffolds. This review outlines the meaningful strategies for repairing osteochondral defects by tissue engineering based on gradient scaffolds and predicts the pros and cons of prospective translation into clinical practice.
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Affiliation(s)
- Yachen Peng
- Department of OrthopedicsChina‐Japan Union Hospital of Jilin UniversityChangchunP. R. China
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchunP. R. China
| | - Yaling Zhuang
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchunP. R. China
| | - Yang Liu
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchunP. R. China
- Institute of BioengineeringÉcole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
| | - Hanxiang Le
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchunP. R. China
| | - Di Li
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchunP. R. China
| | - Mingran Zhang
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchunP. R. China
| | - Kai Liu
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchunP. R. China
| | - Yanbo Zhang
- Department of OrthopedicsChina‐Japan Union Hospital of Jilin UniversityChangchunP. R. China
| | - Jianlin Zuo
- Department of OrthopedicsChina‐Japan Union Hospital of Jilin UniversityChangchunP. R. China
| | - Jianxun Ding
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchunP. R. China
- School of Applied Chemistry and EngineeringUniversity of Science and Technology of ChinaHefeiP. R. China
- Jilin Biomedical Polymers Engineering Laboratory, Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchunP. R. China
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Colombini M, Liu P, Dee C. Triplin: Mechanistic Basis for Voltage Gating. Int J Mol Sci 2023; 24:11473. [PMID: 37511231 PMCID: PMC10380799 DOI: 10.3390/ijms241411473] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 07/05/2023] [Accepted: 07/12/2023] [Indexed: 07/30/2023] Open
Abstract
The outer membrane of Gram-negative bacteria contains a variety of pore-forming structures collectively referred to as porins. Some of these are voltage dependent, but weakly so, closing at high voltages. Triplin, a novel bacterial pore-former, is a three-pore structure, highly voltage dependent, with a complex gating process. The three pores close sequentially: pore 1 at positive potentials, 2 at negative and 3 at positive. A positive domain containing 14 positive charges (the voltage sensor) translocates through the membrane during the closing process, and the translocation is proposed to take place by the domain entering the pore and thus blocking it, resulting in the closed conformation. This mechanism of pore closure is supported by kinetic measurements that show that in the closing process the voltage sensor travels through most of the transmembrane voltage before reaching the energy barrier. Voltage-dependent blockage of the pores by polyarginine, but not by a 500-fold higher concentrations of polylysine, is consistent with the model of pore closure, with the sensor consisting mainly of arginine residues, and with the presence, in each pore, of a complementary surface that serves as a binding site for the sensor.
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Affiliation(s)
- Marco Colombini
- Department of Biology, University of Maryland, College Park, MD 20842, USA
| | - Patrick Liu
- Department of Biology, University of Maryland, College Park, MD 20842, USA
| | - Chase Dee
- Department of Biology, University of Maryland, College Park, MD 20842, USA
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6
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Guerle-Cavero R, Balfagón-Costa A. Study of Elastin, Hydrolyzed Collagen and Collagen-like Products in a Tri-Layered Chitosan Membrane to Test Anti-Aging Skin Properties. Int J Mol Sci 2023; 24:11016. [PMID: 37446192 DOI: 10.3390/ijms241311016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 06/25/2023] [Accepted: 06/28/2023] [Indexed: 07/15/2023] Open
Abstract
The use of animal testing in the cosmetic industry is already prohibited in more than 40 countries, including those of the EU. The pressure for it to be banned worldwide in the future is increasing, so the need for animal alternatives is of great interest today. In addition, using animals and humans in scientific research is ethically reprehensible. This study aimed to prove some of the anti-aging properties of elastin (EL), hydrolyzed collagen (HC), and two vegan collagen-like products (Veg Col) in a tri-layered chitosan membrane that was ionically crosslinked with sodium tripolyphosphate (TPP). In the first approach, as a way of representing different layers of a biological system, such as the epidermis and the two dermis sublayers, EL, HC, or Veg Col were independently introduced into the two inner layers (2L(i+b)). Their effects were compared with those of their introduction into three layers (3L). Different experiments were performed on the membrane to test its elasticity, hydration, moisture retention, and pore reduction at different concentrations of EL, HC, and Veg Col, and the results were normalized vs. a blank membrane. This new alternative to animal or human testing can be suitable for proving certain efficacy claims for active ingredients or products in the pharmaceutical, nutritional, and cosmetic fields.
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Affiliation(s)
- Rocío Guerle-Cavero
- Pharmaceutical Chemistry Research Group, Institut Químic de Sarrià, Universitat Ramon Llull, 08017 Barcelona, Spain
| | - Albert Balfagón-Costa
- Pharmaceutical Chemistry Research Group, Institut Químic de Sarrià, Universitat Ramon Llull, 08017 Barcelona, Spain
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7
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Abstract
According to the endosymbiotic theory, most of the DNA of the original bacterial endosymbiont has been lost or transferred to the nucleus, leaving a much smaller (∼16 kb in mammals), circular molecule that is the present-day mitochondrial DNA (mtDNA). The ability of mtDNA to escape mitochondria and integrate into the nuclear genome was discovered in budding yeast, along with genes that regulate this process. Mitochondria have emerged as key regulators of innate immunity, and it is now recognized that mtDNA released into the cytoplasm, outside of the cell, or into circulation activates multiple innate immune signaling pathways. Here, we first review the mechanisms through which mtDNA is released into the cytoplasm, including several inducible mitochondrial pores and defective mitophagy or autophagy. Next, we cover how the different forms of released mtDNA activate specific innate immune nucleic acid sensors and inflammasomes. Finally, we discuss how intracellular and extracellular mtDNA release, including circulating cell-free mtDNA that promotes systemic inflammation, are implicated in human diseases, bacterial and viral infections, senescence and aging.
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Affiliation(s)
- Laura E Newman
- Salk Institute for Biological Studies, La Jolla, California, USA;
| | - Gerald S Shadel
- Salk Institute for Biological Studies, La Jolla, California, USA;
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Wang N, Liu Q, Xia Y, Li J, Lu Z, Xu Y, Zhong W, Lin Y. Physical Properties and Hydration Characteristics of Low-Heat Portland Cement at High-Altitude. Materials (Basel) 2023; 16:3110. [PMID: 37109945 PMCID: PMC10141411 DOI: 10.3390/ma16083110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 03/30/2023] [Accepted: 04/12/2023] [Indexed: 06/19/2023]
Abstract
High-altitude environments are characterized by low air pressures and temperature variations. Low-heat Portland cement (PLH) is a more energy-efficient alternative to ordinary Portland cement (OPC); however, the hydration properties of PLH at high altitudes have not been previously investigated. Therefore, in this study, the mechanical strengths and levels of the drying shrinkage of PLH mortars under standard, low-air-pressure (LP), and low-air-pressure and variable-temperature (LPT) conditions were evaluated and compared. In addition, the hydration characteristics, pore size distributions, and C-S-H Ca/Si ratio of the PLH pastes under different curing conditions were explored using X-ray diffraction (XRD), thermogravimetric analysis (TG), scanning electron microscopy (SEM), and mercury intrusion porosimetry (MIP). Compared with that of the PLH mortar cured under the standard conditions, the compressive strength of the PLH mortar cured under the LPT conditions was higher at an early curing stage but lower at a later curing stage. In addition, drying shrinkage under the LPT conditions developed rapidly at an early stage but slowly at a later stage. Moreover, the characteristic peaks of ettringite (AFt) were not observed in the XRD pattern after curing for 28 d, and AFt transformed into AFm under the LPT conditions. The pore size distribution characteristics of the specimens cured under the LPT conditions deteriorated, which was related to water evaporation and micro-crack formation at low air pressures. The low pressure hindered the reaction between belite and water, which contributed to a significant change in the C-S-H Ca/Si ratio in the early curing stage in the LPT environment.
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Affiliation(s)
- Ning Wang
- State Key Laboratory of Environment-Friendly Energy Materials, Department of Materials, Southwest University of Science and Technology, Mianyang 621010, China
- Jiahua Special Cement Co., Ltd., Leshan 614003, China
| | - Qiang Liu
- Jiahua Special Cement Co., Ltd., Leshan 614003, China
| | - Yanqing Xia
- State Key Laboratory of Environment-Friendly Energy Materials, Department of Materials, Southwest University of Science and Technology, Mianyang 621010, China
- Jiahua Special Cement Co., Ltd., Leshan 614003, China
| | - Jun Li
- State Key Laboratory of Environment-Friendly Energy Materials, Department of Materials, Southwest University of Science and Technology, Mianyang 621010, China
| | - Zhongyuan Lu
- State Key Laboratory of Environment-Friendly Energy Materials, Department of Materials, Southwest University of Science and Technology, Mianyang 621010, China
| | - Yigang Xu
- Jiahua Special Cement Co., Ltd., Leshan 614003, China
| | - Wen Zhong
- Jiahua Special Cement Co., Ltd., Leshan 614003, China
| | - Yan Lin
- Jiahua Special Cement Co., Ltd., Leshan 614003, China
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Gong H, Zeng Z, Tessier L, Guzman L, Yuan Z, Li S, Zheng W, Chen Y, Qi L. Survival on land: A dark-grown seedling searching for path. Front Plant Sci 2023; 14:1110521. [PMID: 36818829 PMCID: PMC9932276 DOI: 10.3389/fpls.2023.1110521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 01/24/2023] [Indexed: 06/18/2023]
Abstract
To initiate its development into a plant, a small dark-grown seedling (prior to its emergence from the ground) must penetrate through the growth media. The path that the seedling takes during this journey has yet to be explained. As such, we conducted non-destructive tests using CT scans to observe the growth of dark-grown seedlings in soil over time; we also developed a model to simulate the dynamics of an emerging seedling, and to examine effects of various growth medium conditions, including Lunar soil. It was previously postulated that, with gravitropism in a terrestrial growth medium, a dark-grown seedling would grow directly upright. However, our CT scan results showed that dark-grown soybean seedlings departed from the vertical path in soil, as far as a lateral distance of approximately 10 mm. The phenomenon of the non-straight path was also demonstrated by the model results. Through simulations, we found that an emerging seedling naturally weaves through the particles of growth medium, in search for the path of least resistance. As a result, the seedling ends up travelling a longer distance. Compared with a seedling that was artificially forced to take a straight path in a growth media, the seedling taking the natural path encountered significantly lower resistances (20% lower) from the growth medium, while travelled 12% longer distance during the emergence process. A seedling encountered a much higher impedance in Lunar soil. Our results suggest that taking the path of least resistance, in addition to shaping and orientating itself for mechanical advantage, are strategies evolved by plant species that have contributed to its vast success. An understanding of plant behavior and survival strategies on Earth lay the foundation for future research in agriculture in novel environments, including on celestial bodies.
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Affiliation(s)
- Hao Gong
- College of Engineering, South China Agricultural University, Guangzhou, Guangdong, China
- Department of Biosystems Engineering, University of Manitoba, Winnipeg, MB, Canada
| | - Zhiwei Zeng
- Department of Agricultural Engineering Technology, University of Wisconsin-River Falls, WI, River Falls, United States
| | - Léa Tessier
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Leno Guzman
- Department of Biosystems Engineering, University of Manitoba, Winnipeg, MB, Canada
| | - Zihao Yuan
- College of Engineering, South China Agricultural University, Guangzhou, Guangdong, China
| | - Shuai Li
- College of Engineering, South China Agricultural University, Guangzhou, Guangdong, China
| | - Wenhan Zheng
- College of Engineering, South China Agricultural University, Guangzhou, Guangdong, China
| | - Ying Chen
- Department of Biosystems Engineering, University of Manitoba, Winnipeg, MB, Canada
| | - Long Qi
- College of Engineering, South China Agricultural University, Guangzhou, Guangdong, China
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Miyamoto K, Inoue Y, Yan X, Yagi S, Suda S, Furue M. Significant Reversal of Facial Wrinkle, Pigmented Spot and Roughness by Daily Application of Galactomyces Ferment Filtrate-Containing Skin Products for 12 Months-An 11-Year Longitudinal Skin Aging Rejuvenation Study. J Clin Med 2023; 12. [PMID: 36769815 DOI: 10.3390/jcm12031168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 01/18/2023] [Accepted: 01/24/2023] [Indexed: 02/05/2023] Open
Abstract
Facial skin aging is an important psychophysical and social concern, especially in women. We compared facial parameters reflecting aging of the skin in 1999 and 2010 in 86 female volunteers. Then, all subjects applied three Galactomyces ferment filtrate-containing skin care products (G3 products; SK-II Facial Treatment Essence, SK-II Cellumination Essence, and SK-II Skin Signature Cream) twice daily for 12 months (M), with the skin parameters being measured at 2 M, 8 M, and 12 M during this period. Facial skin aging parameters such as wrinkles, hyperpigmented spots, and roughness significantly deteriorated during the 11-year interval. This 11-year aging process was associated with reduced hydration and increased transepidermal water loss (TEWL). Notably, treatment with G3 products significantly and cumulatively increased skin hydration with a correlated reduction of TEWL during the 12 M treatment period. Such treatment also significantly and cumulatively reversed the 11-year facial skin aging in the three parameters of wrinkles, spots, and roughness. These results suggest that facial skin retains the potential to recover from the aging process when it is applied with appropriate cosmetic agents.
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Rando C, Grasso G, Sarkar D, Sciacca MFM, Cucci LM, Cosentino A, Forte G, Pannuzzo M, Satriano C, Bhunia A, La Rosa C. GxxxG Motif Stabilize Ion-Channel like Pores through C α-H···O Interaction in Aβ (1-40). Int J Mol Sci 2023; 24:ijms24032192. [PMID: 36768518 PMCID: PMC9917128 DOI: 10.3390/ijms24032192] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 01/18/2023] [Accepted: 01/19/2023] [Indexed: 01/24/2023] Open
Abstract
Aβ (1-40) can transfer from the aqueous phase to the bilayer and thus form stable ion-channel-like pores where the protein has alpha-helical conformation. The stability of the pores is due to the presence of the GXXXG motif. It has been reported that these ion-channel-like pores are stabilized by a Cα-H···O hydrogen bond that is established between a glycine of the GXXXG sequence of an alpha-helix and another amino acid of a vicinal alpha-helix. However, conflicting data are reported in the literature. Some authors have suggested that hydrogen bonding does not have a stabilizing function. Here we synthesized pentapeptides having a GXXXG motif to explore its role in pore stability. We used molecular dynamics simulations, quantum mechanics, and experimental biophysical techniques to determine whether hydrogen bonding was formed and had a stabilizing function in ion-channel-like structures. Starting from our previous molecular dynamics data, molecular quantum mechanics simulations, and ATR data showed that a stable ion-channel-like pore formed and a band centered at 2910 cm-1 was attributed to the interaction between Gly 7 of an alpha-helix and Asp 23 of a vicinal alpha-helix.
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Affiliation(s)
- Carola Rando
- Dipartimento di Scienze Chimiche, Università degli Studi di Catania, Viale A. Doria 6, 95125 Catania, Italy
| | - Giuseppe Grasso
- Dipartimento di Scienze Chimiche, Università degli Studi di Catania, Viale A. Doria 6, 95125 Catania, Italy
| | - Dibakar Sarkar
- Department of Biophysics Bose Institute, Unified Academic Campus, Bidhan Nagar, EN 80, Kolkata 700091, India
| | | | - Lorena Maria Cucci
- Dipartimento di Scienze Chimiche, Università degli Studi di Catania, Viale A. Doria 6, 95125 Catania, Italy
| | - Alessia Cosentino
- Dipartimento di Scienze Chimiche, Università degli Studi di Catania, Viale A. Doria 6, 95125 Catania, Italy
| | - Giuseppe Forte
- Dipartimento di Scienze del Farmaco e della Salute, Università degli Studi di Catania, Viale A. Doria 6, 95125 Catania, Italy
| | - Martina Pannuzzo
- Laboratory of Nanotechnology for Precision Medicine, Fondazione Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
| | - Cristina Satriano
- Dipartimento di Scienze Chimiche, Università degli Studi di Catania, Viale A. Doria 6, 95125 Catania, Italy
| | - Anirban Bhunia
- Department of Biophysics Bose Institute, Unified Academic Campus, Bidhan Nagar, EN 80, Kolkata 700091, India
| | - Carmelo La Rosa
- Dipartimento di Scienze Chimiche, Università degli Studi di Catania, Viale A. Doria 6, 95125 Catania, Italy
- Correspondence:
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12
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Abstract
Porous scaffolds have been widely explored for tissue regeneration and engineering in vitro three-dimensional models. In this review, a comprehensive literature analysis is conducted to identify the steps involved in their generation. The advantages and disadvantages of the available techniques are discussed, highlighting the importance of considering pore geometrical parameters such as curvature and size, and summarizing the requirements to generate the porous scaffold according to the desired application. This paper considers the available design tools, mathematical models, materials, fabrication techniques, cell seeding methodologies, assessment methods, and the status of pore scaffolds in clinical applications. This review compiles the relevant research in the field in the past years. The trends, challenges, and future research directions are discussed in the search for the generation of a porous scaffold with improved mechanical and biological properties that can be reproducible, viable for long-term studies, and closer to being used in the clinical field.
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Affiliation(s)
- Mariana S Flores-Jiménez
- Escuela de Ingeniería y Ciencias, Tecnologico de Monterrey Campus Guadalajara, Av. Gral. Ramon Corona No 2514, Colonia Nuevo México, 45121Zapopan, Jalisco, México
| | - Alejandro Garcia-Gonzalez
- Escuela de Medicina, Tecnologico de Monterrey Campus Guadalajara, Av. Gral. Ramon Corona No 2514, Colonia Nuevo México, 45121Zapopan, Jalisco, México
| | - Rita Q Fuentes-Aguilar
- Institute of Advanced Materials and Sustainable Manufacturing, Tecnologico de Monterrey Campus Guadalajara, Av. Gral. Ramon Corona No 2514, Colonia Nuevo México, 45121Zapopan, Jalisco, México
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13
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Leung CLA, Luczyniec D, Guo E, Marussi S, Atwood RC, Meisnar M, Saunders B, Lee PD. Quantification of Interdependent Dynamics during Laser Additive Manufacturing Using X-Ray Imaging Informed Multi-Physics and Multiphase Simulation. Adv Sci (Weinh) 2022; 9:e2203546. [PMID: 36316220 PMCID: PMC9798986 DOI: 10.1002/advs.202203546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Revised: 09/28/2022] [Indexed: 06/16/2023]
Abstract
Laser powder bed fusion (LPBF) can produce high-value metallic components for many industries; however, its adoption for safety-critical applications is hampered by the presence of imperfections. The interdependency between imperfections and processing parameters remains unclear. Here, the evolution of porosity and humps during LPBF using X-ray and electron imaging, and a high-fidelity multiphase process simulation, is quantified. The pore and keyhole formation mechanisms are driven by the mixing of high temperatures and high metal vapor concentrations in the keyhole is revealed. The irregular pores are formed via keyhole collapse, pore coalescence, and then pore entrapment by the solidification front. The mixing of the fast-moving vapor plume and molten pool induces a Kelvin-Helmholtz instability at the melt track surface, forming humps. X-ray imaging and a high-fidelity model are used to quantify the pore evolution kinetics, pore size distribution, waviness, surface roughness, and melt volume under single layer conditions. This work provides insights on key criteria that govern the formation of imperfections in LPBF and suggest ways to improve process reliability.
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Affiliation(s)
- Chu Lun Alex Leung
- Department of Mechanical EngineeringUniversity College LondonTorrington PlaceLondonWC1E 7JEUK
- Research Complex at HarwellScience & Technology Facilities CouncilRutherford Appleton LaboratoryOxfordshireOX11 0QXUK
| | | | - Enyu Guo
- Key Laboratory of Solidification Control and Digital Preparation Technology (Liaoning Province)School of Materials Science and EngineeringDalian University of TechnologyDalian116024China
| | - Sebastian Marussi
- Department of Mechanical EngineeringUniversity College LondonTorrington PlaceLondonWC1E 7JEUK
- Research Complex at HarwellScience & Technology Facilities CouncilRutherford Appleton LaboratoryOxfordshireOX11 0QXUK
| | - Robert C. Atwood
- Diamond Light Source LtdHarwell Science & Innovation CampusOxfordshireOX11 0DEUK
| | - Martina Meisnar
- European Space AgencyESA‐RAL Advanced Manufacturing LaboratoryHarwell‐Oxford CampusFermi AvenueDidcotOX110FDUK
| | - Ben Saunders
- Rolls Royce plcElton Road Site, North BlockDerbyDE24 8BJUK
| | - Peter D. Lee
- Department of Mechanical EngineeringUniversity College LondonTorrington PlaceLondonWC1E 7JEUK
- Research Complex at HarwellScience & Technology Facilities CouncilRutherford Appleton LaboratoryOxfordshireOX11 0QXUK
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14
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Han J, Zhu H, Lu Y, Yang S, Yang M, Shi E, Qi Y. Microstructural Analysis of Organic-Rich Shales: Insights from an Electron Microscopic Study by Application of FIBSEM and TEM. Nanomaterials (Basel) 2022; 12:4135. [PMID: 36500762 PMCID: PMC9739040 DOI: 10.3390/nano12234135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 11/17/2022] [Accepted: 11/21/2022] [Indexed: 06/17/2023]
Abstract
Matrix-related pores play a significant role in controlling hydrocarbon production in organic-rich shales. Multiple matrix-related pore types of typical marine shales in the Sichuan Basin have been visually investigated and identified by transmission electron microscopy (TEM) on ultra-thin sections and by focused ion beam-scanning electron microscopy (FIBSEM) on polished sections. OM-hosted pores seem universal and range in sizes from below 1 nm to hundreds of nanometers and they are not homogeneously developed and distributed, which is mainly determined by thermal maturity and OM composition. Mineral-hosted pores are defined by mineral frameworks and occur in open spaces related to ductile or rigid grain fabric. The four porous mineral types that occur are clay intrapores, carbonate solvopores, pyrite interpores, and quartz interpores, and they range in size from less than 1 nm to more than several microns. Aggregate-hosted pores are predominantly associated with clay-organic aggregates, pyrite-organic aggregates, clay-pyrite aggregates, and clay-organic-pyrite aggregates. The most common aggregate-hosted pore networks are defined by clay-organic aggregates, and the pores are largely developed between the clay and organic layers and may be the important adsorption spaces for methane. Fracture-related pores include microchannels and microfractures of various sizes and shapes and they could play a key role in providing hydrocarbon migration pathways. FIBSEM and TEM show direct evidence that OM-hosted pores and fracture-related pores contribute more to the effective pore network and the excellent reservoir quality, whereas poor reservoir quality may come from aggregate-hosted pores.
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Affiliation(s)
- Jinxuan Han
- School of Vehicle and Energy, Yanshan University, Qinhuangdao 066000, China
| | - Hongjian Zhu
- School of Vehicle and Energy, Yanshan University, Qinhuangdao 066000, China
- State Key Laboratory of Continental Dynamics, Northwest University, Xi’an 710069, China
| | - Yanjun Lu
- School of Vehicle and Energy, Yanshan University, Qinhuangdao 066000, China
| | - Su Yang
- Petroleum Engineering Technology Research Institute, Sinopec Southwest Oil and Gas Company, Deyang 618000, China
| | - Manping Yang
- School of Vehicle and Energy, Yanshan University, Qinhuangdao 066000, China
| | - Erxiu Shi
- School of Vehicle and Energy, Yanshan University, Qinhuangdao 066000, China
| | - Yu Qi
- School of Vehicle and Energy, Yanshan University, Qinhuangdao 066000, China
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15
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Colombini M, Barnes K, Chang KT, Younis MH, Aguilella VM. Triplin: Functional Probing of Its Structure and the Dynamics of the Voltage-Gating Process. Int J Mol Sci 2022; 23. [PMID: 36430243 DOI: 10.3390/ijms232213765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Revised: 11/05/2022] [Accepted: 11/07/2022] [Indexed: 11/11/2022] Open
Abstract
Gram-negative bacteria have a large variety of channel-forming proteins in their outer membrane, generally referred to as porins. Some display weak voltage dependence. A similar trimeric channel former, named Triplin, displays very steep voltage dependence, rivaling that responsible for the electrical excitability of mammals, and high inter-subunit cooperativity. We report detailed insights into the molecular basis for these very unusual properties explored at the single-molecule level. By using chemical modification to reduce the charge on the voltage sensors, they were shown to be positively charged structures. Trypsin cleavage of the sensor eliminates voltage gating by cleaving the sensor. From asymmetrical addition of these reagents, the positively charged voltage sensors translocate across the membrane and are, thus, responsible energetically for the steep voltage dependence. A mechanism underlying the cooperativity was also identified. Theoretical calculations indicate that the charge on the voltage sensor can explain the rectification of the current flowing through the open pores if it is located near the pore mouth in the open state. All results support the hypothesis that one of the three subunits is oriented in a direction opposite to that of the other two. These properties make Triplin perhaps the most complex pore-forming molecular machine described to date.
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16
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Zhang Y, An B, Wang W, Zhang B, He C, Luo H, Wang Q. Actin-bundling protein fimbrin regulates pathogenicity via organizing F-actin dynamics during appressorium development in Colletotrichum gloeosporioides. Mol Plant Pathol 2022; 23:1472-1486. [PMID: 35791045 PMCID: PMC9452767 DOI: 10.1111/mpp.13242] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 06/12/2022] [Accepted: 06/14/2022] [Indexed: 06/15/2023]
Abstract
Anthracnose caused by Colletotrichum gloeosporioides leads to serious economic loss to rubber tree yield and other tropical crops. The appressorium, a specialized dome-shaped infection structure, plays a crucial role in the pathogenesis of C. gloeosporioides. However, the mechanism of how actin cytoskeleton dynamics regulate appressorium formation and penetration remains poorly defined in C. gloeosporioides. In this study, an actin cross-linking protein fimbrin homologue (CgFim1) was identified in C. gloeosporioides, and the knockout of CgFim1 led to impairment in vegetative growth, conidiation, and pathogenicity. We then investigated the roles of CgFim1 in the dynamic organization of the actin cytoskeleton. We observed that actin patches and cables localized at the apical and subapical regions of the hyphal tip, and showed a disc-to-ring dynamic around the pore during appressorium development. CgFim1 showed a similar distribution pattern to the actin cytoskeleton. Moreover, knockout of CgFim1 affected the polarity of the actin cytoskeleton in the hyphal tip and disrupted the actin dynamics and ring structure formation in the appressorium, which prevented polar growth and appressorium development. The CgFim1 mutant also interfered with the septin structure formation. This caused defects in pore wall overlay formation, pore contraction, and the extension of the penetration peg. These results reveal the mechanism by which CgFim1 regulates the growth and pathogenicity of C. gloeosporioides by organizing the actin cytoskeleton.
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Affiliation(s)
- Yi Zhang
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresource, Key Laboratory of Biotechnology of Salt Tolerant Crops of Hainan ProvinceCollege of Tropical Crops, Hainan UniversityHaikouChina
- Sanya Nanfan Research Institute of Hainan University, Hainan Yazhou Bay Seed LaboratorySanyaChina
| | - Bang An
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresource, Key Laboratory of Biotechnology of Salt Tolerant Crops of Hainan ProvinceCollege of Tropical Crops, Hainan UniversityHaikouChina
- Sanya Nanfan Research Institute of Hainan University, Hainan Yazhou Bay Seed LaboratorySanyaChina
| | - Wenfeng Wang
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresource, Key Laboratory of Biotechnology of Salt Tolerant Crops of Hainan ProvinceCollege of Tropical Crops, Hainan UniversityHaikouChina
| | - Bei Zhang
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresource, Key Laboratory of Biotechnology of Salt Tolerant Crops of Hainan ProvinceCollege of Tropical Crops, Hainan UniversityHaikouChina
- Sanya Nanfan Research Institute of Hainan University, Hainan Yazhou Bay Seed LaboratorySanyaChina
| | - Chaozu He
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresource, Key Laboratory of Biotechnology of Salt Tolerant Crops of Hainan ProvinceCollege of Tropical Crops, Hainan UniversityHaikouChina
- Sanya Nanfan Research Institute of Hainan University, Hainan Yazhou Bay Seed LaboratorySanyaChina
| | - Hongli Luo
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresource, Key Laboratory of Biotechnology of Salt Tolerant Crops of Hainan ProvinceCollege of Tropical Crops, Hainan UniversityHaikouChina
- Sanya Nanfan Research Institute of Hainan University, Hainan Yazhou Bay Seed LaboratorySanyaChina
| | - Qiannan Wang
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresource, Key Laboratory of Biotechnology of Salt Tolerant Crops of Hainan ProvinceCollege of Tropical Crops, Hainan UniversityHaikouChina
- Sanya Nanfan Research Institute of Hainan University, Hainan Yazhou Bay Seed LaboratorySanyaChina
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17
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He S, Singh D, Helfield B. An Overview of Cell Membrane Perforation and Resealing Mechanisms for Localized Drug Delivery. Pharmaceutics 2022; 14:886. [PMID: 35456718 DOI: 10.3390/pharmaceutics14040886] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 04/09/2022] [Accepted: 04/14/2022] [Indexed: 01/04/2023] Open
Abstract
Localized and reversible plasma membrane disruption is a promising technique employed for the targeted deposition of exogenous therapeutic compounds for the treatment of disease. Indeed, the plasma membrane represents a significant barrier to successful delivery, and various physical methods using light, sound, and electrical energy have been developed to generate cell membrane perforations to circumvent this issue. To restore homeostasis and preserve viability, localized cellular repair mechanisms are subsequently triggered to initiate a rapid restoration of plasma membrane integrity. Here, we summarize the known emergency membrane repair responses, detailing the salient membrane sealing proteins as well as the underlying cytoskeletal remodeling that follows the physical induction of a localized plasma membrane pore, and we present an overview of potential modulation strategies that may improve targeted drug delivery approaches.
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18
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Ramli MII, Salleh MAAM, Abdullah MMAB, Aziz IH, Ying TC, Shahedan NF, Kockelmann W, Fedrigo A, Sandu AV, Vizureanu P, Chaiprapa J, Burduhos Nergis DD. The Influence of Sintering Temperature on the Pore Structure of an Alkali-Activated Kaolin-Based Geopolymer Ceramic. Materials (Basel) 2022; 15:2667. [PMID: 35408007 DOI: 10.3390/ma15072667] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 03/30/2022] [Accepted: 04/02/2022] [Indexed: 12/04/2022]
Abstract
Geopolymer materials are used as construction materials due to their lower carbon dioxide (CO2) emissions compared with conventional cementitious materials. An example of a geopolymer material is alkali-activated kaolin, which is a viable alternative for producing high-strength ceramics. Producing high-performing kaolin ceramics using the conventional method requires a high processing temperature (over 1200 °C). However, properties such as pore size and distribution are affected at high sintering temperatures. Therefore, knowledge regarding the sintering process and related pore structures on alkali-activated kaolin geopolymer ceramic is crucial for optimizing the properties of the aforementioned materials. Pore size was analyzed using neutron tomography, while pore distribution was observed using synchrotron micro-XRF. This study elucidated the pore structure of alkali-activated kaolin at various sintering temperatures. The experiments showed the presence of open pores and closed pores in alkali-activated kaolin geopolymer ceramic samples. The distributions of the main elements within the geopolymer ceramic edifice were found with Si and Al maps, allowing for the identification of the kaolin geopolymer. The results also confirmed that increasing the sintering temperature to 1100 °C resulted in the alkali-activated kaolin geopolymer ceramic samples having large pores, with an average size of ~80 µm3 and a layered porosity distribution.
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19
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Michels PAM, Gualdrón-López M. Biogenesis and metabolic homeostasis of trypanosomatid glycosomes: new insights and new questions. J Eukaryot Microbiol 2022; 69:e12897. [PMID: 35175680 DOI: 10.1111/jeu.12897] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 02/14/2022] [Accepted: 02/14/2022] [Indexed: 11/28/2022]
Abstract
Kinetoplastea and Diplonemea possess peroxisome-related organelles that, uniquely, contain most of the enzymes of the glycolytic pathway and are hence called glycosomes. Enzymes of several other core metabolic pathways have also been located in glycosomes, in addition to some characteristic peroxisomal systems such as pathways of lipid metabolism. A considerable amount of research has been performed on glycosomes of trypanosomes since their discovery four decades ago. Not only the role of the glycosomal enzyme systems in the overall cell metabolism appeared to be unique, but the organelles display also remarkable features regarding their biogenesis and structural properties. These features are similar to those of the well-studied peroxisomes of mammalian and plant cells and yeasts yet exhibit also differences reflecting the large evolutionary distance between these protists and the representatives of other major eukaryotic lineages. Despite all research performed, many questions remain about various properties and the biological roles of glycosomes and peroxisomes. Here we review the current knowledge about glycosomes, often comparing it with information about peroxisomes. Furthermore, we highlight particularly many questions that remain about the biogenesis, and the heterogeneity in structure and content of these enigmatic organelles, and the properties of their boundary membrane.
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Affiliation(s)
- Paul A M Michels
- Centre for Immunity, Infection and Evolution and Centre for Translational and Chemical Biology, The University of Edinburgh, Edinburgh, United Kingdom
| | - Melisa Gualdrón-López
- Instituto Salud Global, Hospital Clinic-Universitat de Barcelona, and Institute for Health Sciences Trias i Pujol, Barcelona, Spain
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20
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Volynsky PE, Smirnova AI, Akimov SA, Sokolov SS, Severin FF. The Membrane-Water Partition Coefficients of Antifungal, but Not Antibacterial, Membrane-Active Compounds Are Similar. Front Microbiol 2021; 12:756408. [PMID: 34803981 PMCID: PMC8602886 DOI: 10.3389/fmicb.2021.756408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 10/12/2021] [Indexed: 11/13/2022] Open
Affiliation(s)
- Pavel E. Volynsky
- Laboratory of Biomolecular Modeling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences (RAS), Moscow, Russia
| | - Alexandra I. Smirnova
- Department of Molecular Energetics of Microorganisms, Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russia
| | - Sergey A. Akimov
- Laboratory of Bioelectrochemistry, A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences (RAS), Moscow, Russia
| | - Svyatoslav S. Sokolov
- Department of Molecular Energetics of Microorganisms, Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Fedor F. Severin
- Department of Molecular Energetics of Microorganisms, Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
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21
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Smolyanskii AS, Politova ED, Koshkina OA, Arsentyev MA, Kusch PP, Moskvitin LV, Slesarenko SV, Kiryukhin DP, Trakhtenberg LI. Structure of Polytetrafluoroethylene Modified by the Combined Action of γ-Radiation and High Temperatures. Polymers (Basel) 2021; 13:3678. [PMID: 34771235 DOI: 10.3390/polym13213678] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 10/11/2021] [Accepted: 10/12/2021] [Indexed: 01/26/2023] Open
Abstract
By means of X-ray computed microtomography (XCMT), the existence of a developed porous structure with an average pore diameter of ~3.5 μm and pore content of ~1.1 vol.% has been revealed in unirradiated polytetrafluoroethylene (PTFE). It has been found that the combined action of gamma radiation (absorbed dose per PTFE of ~170 kGy) and high temperatures (327–350 °C) leads to the disappearance of the porous structure and the formation of several large pores with sizes from 30 to 50 μm in the bulk of thermal-radiation modified PTFE (TRM-PTFE). It has been established by X-ray diffraction (XRD) analysis that the thermal-radiation modification of PTFE leads to an increase in the interplanar spacings, the degree of crystallinity and the volume of the unit cell, as well as to a decrease in the size of crystals and the X-ray density of the crystalline phase in comparison with the initial polymer. It is assumed that the previously-established effect of improving the deformation-strength and tribological properties of the TRM-PTFE can be due not only to the radiation cross-linking of polymer chains but also to the disappearance of the pore system and to the ordering of the crystalline phase of PTFE.
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22
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Saponaro A, Bauer D, Giese MH, Swuec P, Porro A, Gasparri F, Sharifzadeh AS, Chaves-Sanjuan A, Alberio L, Parisi G, Cerutti G, Clarke OB, Hamacher K, Colecraft HM, Mancia F, Hendrickson WA, Siegelbaum SA, DiFrancesco D, Bolognesi M, Thiel G, Santoro B, Moroni A. Gating movements and ion permeation in HCN4 pacemaker channels. Mol Cell 2021; 81:2929-2943.e6. [PMID: 34166608 PMCID: PMC8294335 DOI: 10.1016/j.molcel.2021.05.033] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 04/12/2021] [Accepted: 05/27/2021] [Indexed: 10/31/2022]
Abstract
The HCN1-4 channel family is responsible for the hyperpolarization-activated cation current If/Ih that controls automaticity in cardiac and neuronal pacemaker cells. We present cryoelectron microscopy (cryo-EM) structures of HCN4 in the presence or absence of bound cAMP, displaying the pore domain in closed and open conformations. Analysis of cAMP-bound and -unbound structures sheds light on how ligand-induced transitions in the channel cytosolic portion mediate the effect of cAMP on channel gating and highlights the regulatory role of a Mg2+ coordination site formed between the C-linker and the S4-S5 linker. Comparison of open/closed pore states shows that the cytosolic gate opens through concerted movements of the S5 and S6 transmembrane helices. Furthermore, in combination with molecular dynamics analyses, the open pore structures provide insights into the mechanisms of K+/Na+ permeation. Our results contribute mechanistic understanding on HCN channel gating, cyclic nucleotide-dependent modulation, and ion permeation.
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Affiliation(s)
- Andrea Saponaro
- Department of Biosciences, University of Milan, Milan, Italy
| | - Daniel Bauer
- Department of Biology, TU-Darmstadt, Darmstadt, Germany
| | - M Hunter Giese
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY, USA
| | - Paolo Swuec
- Department of Biosciences, University of Milan, Milan, Italy; Pediatric Research Center "Romeo ed Enrica Invernizzi," University of Milan, Milan, Italy
| | | | | | | | - Antonio Chaves-Sanjuan
- Department of Biosciences, University of Milan, Milan, Italy; Pediatric Research Center "Romeo ed Enrica Invernizzi," University of Milan, Milan, Italy
| | - Laura Alberio
- Department of Biosciences, University of Milan, Milan, Italy; Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Giacomo Parisi
- Center for Life Nano Science, Istituto Italiano di Tecnologia, Rome, Italy
| | - Gabriele Cerutti
- Department of Biochemical Sciences, Sapienza University of Rome, Rome, Italy
| | - Oliver B Clarke
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY, USA; Department of Anesthesiology, Columbia University, New York, NY, USA
| | - Kay Hamacher
- Department of Biology, TU-Darmstadt, Darmstadt, Germany
| | - Henry M Colecraft
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY, USA
| | - Filippo Mancia
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY, USA
| | - Wayne A Hendrickson
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY, USA; Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Steven A Siegelbaum
- Department of Neuroscience, Zuckerman Institute, Columbia University, New York, NY, USA
| | - Dario DiFrancesco
- Department of Biosciences, University of Milan, Milan, Italy; Institute of Biophysics-Milano, Consiglio Nazionale delle Ricerche, Rome, Italy
| | - Martino Bolognesi
- Department of Biosciences, University of Milan, Milan, Italy; Pediatric Research Center "Romeo ed Enrica Invernizzi," University of Milan, Milan, Italy
| | - Gerhard Thiel
- Department of Biology, TU-Darmstadt, Darmstadt, Germany
| | - Bina Santoro
- Department of Neuroscience, Zuckerman Institute, Columbia University, New York, NY, USA.
| | - Anna Moroni
- Department of Biosciences, University of Milan, Milan, Italy; Institute of Biophysics-Milano, Consiglio Nazionale delle Ricerche, Rome, Italy.
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23
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Hojjatzadeh SMH, Guo Q, Parab ND, Qu M, Escano LI, Fezzaa K, Everhart W, Sun T, Chen L. In-Situ Characterization of Pore Formation Dynamics in Pulsed Wave Laser Powder Bed Fusion. Materials (Basel) 2021; 14:ma14112936. [PMID: 34072400 PMCID: PMC8198083 DOI: 10.3390/ma14112936] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 05/24/2021] [Accepted: 05/25/2021] [Indexed: 02/05/2023]
Abstract
Laser powder bed fusion (LPBF) is an additive manufacturing technology with the capability of printing complex metal parts directly from digital models. Between two available emission modes employed in LPBF printing systems, pulsed wave (PW) emission provides more control over the heat input compared to continuous wave (CW) emission, which is highly beneficial for printing parts with intricate features. However, parts printed with pulsed wave LPBF (PW-LPBF) commonly contain pores, which degrade their mechanical properties. In this study, we reveal pore formation mechanisms during PW-LPBF in real time by using an in-situ high-speed synchrotron x-ray imaging technique. We found that vapor depression collapse proceeds when the laser irradiation stops within one pulse, resulting in occasional pore formation during PW-LPBF. We also revealed that the melt ejection and rapid melt pool solidification during pulsed-wave laser melting resulted in cavity formation and subsequent formation of a pore pattern in the melted track. The pore formation dynamics revealed here may provide guidance on developing pore elimination approaches.
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Affiliation(s)
- Seyed Mohammad H. Hojjatzadeh
- Department of Mechanical Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA; (S.M.H.H.); (Q.G.); (M.Q.); (L.I.E.)
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Qilin Guo
- Department of Mechanical Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA; (S.M.H.H.); (Q.G.); (M.Q.); (L.I.E.)
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Niranjan D. Parab
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, IL 60439, USA; (N.D.P.); (K.F.)
| | - Minglei Qu
- Department of Mechanical Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA; (S.M.H.H.); (Q.G.); (M.Q.); (L.I.E.)
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Luis I. Escano
- Department of Mechanical Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA; (S.M.H.H.); (Q.G.); (M.Q.); (L.I.E.)
| | - Kamel Fezzaa
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, IL 60439, USA; (N.D.P.); (K.F.)
| | - Wes Everhart
- Department of Energy’s Kansas City National Security Campus Managed by Honeywell FM&T, Kansas City, MO 64147, USA;
| | - Tao Sun
- Department of Materials Science and Engineering, University of Virginia, Charlottesville, VA 22904, USA
- Correspondence: (T.S.); (L.C.)
| | - Lianyi Chen
- Department of Mechanical Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA; (S.M.H.H.); (Q.G.); (M.Q.); (L.I.E.)
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA
- Correspondence: (T.S.); (L.C.)
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Hemmatian T, Lee H, Kim J. Bacteria Adhesion of Textiles Influenced by Wettability and Pore Characteristics of Fibrous Substrates. Polymers (Basel) 2021; 13:E223. [PMID: 33440678 PMCID: PMC7827894 DOI: 10.3390/polym13020223] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 01/05/2021] [Accepted: 01/08/2021] [Indexed: 11/16/2022] Open
Abstract
Bacteria adhesion on the surface is an initial step to create biofouling, which may lead to a severe infection of living organisms and humans. This study is concerned with investigating the textile properties including wettability, porosity, total pore volume, and pore size in association with bacteria adhesion. As model bacteria, Gram-negative, rod-shaped Escherichia coli and the Gram-positive, spherical-shaped Staphylococcus aureus were used to analyze the adhesion tendency. Electrospun webs made from polystyrene and poly(lactic acid) were used as substrates, with modification of wettability by the plasma process using either O2 or C4F8 gas. The pore and morphological characteristics of fibrous webs were analyzed by the capillary flow porometer and scanning electron microscopy. The substrate's wettability appeared to be the primary factor influencing the cell adhesion, where the hydrophilic surface resulted in considerably higher adhesion. The pore volume and the pore size, rather than the porosity itself, were other important factors affecting the bacteria adherence and retention. In addition, the compact spatial distribution of fibers limited the cell intrusion into the pores, reducing the total amount of adherence. Thus, superhydrophobic textiles with the reduced total pore volume and smaller pore size would circumvent the adhesion. The findings of this study provide informative discussion on the characteristics of fibrous webs affecting the bacteria adhesion, which can be used as a fundamental design guide of anti-biofouling textiles.
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Affiliation(s)
- Tahmineh Hemmatian
- Department of Textiles, Merchandising and Fashion Design, Seoul National University, Seoul 08826, Korea; (T.H.); (H.L.)
| | - Halim Lee
- Department of Textiles, Merchandising and Fashion Design, Seoul National University, Seoul 08826, Korea; (T.H.); (H.L.)
| | - Jooyoun Kim
- Department of Textiles, Merchandising and Fashion Design, Seoul National University, Seoul 08826, Korea; (T.H.); (H.L.)
- Research Institute of Human Ecology, Seoul National University, Seoul 08826, Korea
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25
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Jamshidi M, Falamaki C. Image analysis method for heterogeneity and porosity characterization of biomimetic hydrogels. F1000Res 2020; 9:1461. [PMID: 34276966 PMCID: PMC8256190 DOI: 10.12688/f1000research.27372.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/31/2021] [Indexed: 11/20/2022] Open
Abstract
This work presents an image processing procedure for characterization of porosity and heterogeneity of hydrogels network mainly based on the analysis of cryogenic scanning electron microscopy (cryo-SEM) images and can be extended to any other type of microscopy images of hydrogel porous network. An algorithm consisting of different filtering, morphological transformation, and thresholding steps to denoise the image whilst emphasizing the edges of the hydrogel walls for extracting either the pores or hydrogel walls features is explained. Finally, the information of hydrogel porosity and heterogeneity is presented in form of pore size distribution, spatial contours maps and kernel density dot plots. The obtained results reveal that a non-parametric kernel density plot effectively determines the spatial heterogeneity and porosity of the hydrogel.
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Affiliation(s)
- Maryam Jamshidi
- Chemical Engineering Department, Amirkabir University of Technology, P.O. Box 15875-4413, Tehran, Iran
| | - Cavus Falamaki
- Chemical Engineering Department, Amirkabir University of Technology, P.O. Box 15875-4413, Tehran, Iran
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Roh S, Song M, Lee K, Park K, Kim J. Experimental and Computational Investigation of Intra- and Interlayer Space for Enhanced Depth Filtration and Reduced Pressure Drop. ACS Appl Mater Interfaces 2020; 12:46804-46815. [PMID: 32990419 DOI: 10.1021/acsami.0c14958] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The buildup of pressure drop with mass loading of particles aggravates the breathing resistance and energy consumption of filters. This study investigated the role of intra- and interlayer space of filter media on the pressure drop development with continued particle loading. Five basic morphologies, including microfibers, nanofibers, microbeads-on-strings, and a mix of those morphologies were fabricated via electrospinning. Then the variations of layered constructions were made, to include a total 14 different filter structures. For a single layer filter media, the pore size rather than the percent porosity had a major impact on the pressure drop. For dual layers, the space between the layers and the placement order of webs were important factors affecting the pressure drop and depth loading of particles. Computational modeling was used to interpret the role of the interlayer space on the pressure drop, by monitoring the air flow and particle movement within the filter constructions, where the computational prediction corresponded to the tendency of the experimental findings. The novelty of this study lies in the combined approach of the experimental and computational work to understand the particle capture phenomenon during the mass loading.
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Affiliation(s)
- Sanghyun Roh
- Department of Textiles, Merchandising and Fashion Design, Seoul National University, Seoul 08826, Korea
| | - Minwoo Song
- Reliability Assessment Center, FITI Testing & Research Institute, Seoul 07791, Korea
| | - Kyeongeun Lee
- Department of Textiles, Merchandising and Fashion Design, Seoul National University, Seoul 08826, Korea
- Reliability Assessment Center, FITI Testing & Research Institute, Seoul 07791, Korea
| | - Kangsoo Park
- R&D Center, Satrec Initiative Company, Limited, Daejeon 34054, Korea
| | - Jooyoun Kim
- Department of Textiles, Merchandising and Fashion Design, Seoul National University, Seoul 08826, Korea
- Research Institute of Human Ecology, Seoul National University, Seoul 08826, Korea
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Waldherr L, Tiffner A, Mishra D, Sallinger M, Schober R, Frischauf I, Schmidt T, Handl V, Sagmeister P, Köckinger M, Derler I, Üçal M, Bonhenry D, Patz S, Schindl R. Blockage of Store-Operated Ca 2+ Influx by Synta66 is Mediated by Direct Inhibition of the Ca 2+ Selective Orai1 Pore. Cancers (Basel) 2020; 12:E2876. [PMID: 33036292 PMCID: PMC7600887 DOI: 10.3390/cancers12102876] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 09/29/2020] [Accepted: 09/30/2020] [Indexed: 12/14/2022] Open
Abstract
The Ca2+ sensor STIM1 and the Ca2+ channel Orai1 that form the store-operated Ca2+ (SOC) channel complex are key targets for drug development. Selective SOC inhibitors are currently undergoing clinical evaluation for the treatment of auto-immune and inflammatory responses and are also deemed promising anti-neoplastic agents since SOC channels are linked with enhanced cancer cell progression. Here, we describe an investigation of the site of binding of the selective inhibitor Synta66 to the SOC channel Orai1 using docking and molecular dynamics simulations, and live cell recordings. Synta66 binding was localized to the extracellular site close to the transmembrane (TM)1 and TM3 helices and the extracellular loop segments, which, importantly, are adjacent to the Orai1-selectivity filter. Synta66-sensitivity of the Orai1 pore was, in fact, diminished by both Orai1 mutations affecting Ca2+ selectivity and permeation of Na+ in the absence of Ca2+. Synta66 also efficiently blocked SOC in three glioblastoma cell lines but failed to interfere with cell viability, division and migration. These experiments provide new structural and functional insights into selective drug inhibition of the Orai1 Ca2+ channel by a high-affinity pore blocker.
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Affiliation(s)
- Linda Waldherr
- Gottfried Schatz Research Centre, Medical University of Graz, A-8010 Graz, Austria; (L.W.); (R.S.); (T.S.)
| | - Adela Tiffner
- Institute of Biophysics, JKU Life Science Centre, Johannes Kepler University Linz, A-4020 Linz, Austria; (A.T.); (M.S.); (I.F.); (I.D.)
| | - Deepti Mishra
- Centre for Nanobiology and Structural Biology, Academy of Sciences of the Czech Republic, 373 33 Nové Hrady, Czech Republic;
| | - Matthias Sallinger
- Institute of Biophysics, JKU Life Science Centre, Johannes Kepler University Linz, A-4020 Linz, Austria; (A.T.); (M.S.); (I.F.); (I.D.)
| | - Romana Schober
- Gottfried Schatz Research Centre, Medical University of Graz, A-8010 Graz, Austria; (L.W.); (R.S.); (T.S.)
- Institute of Biophysics, JKU Life Science Centre, Johannes Kepler University Linz, A-4020 Linz, Austria; (A.T.); (M.S.); (I.F.); (I.D.)
| | - Irene Frischauf
- Institute of Biophysics, JKU Life Science Centre, Johannes Kepler University Linz, A-4020 Linz, Austria; (A.T.); (M.S.); (I.F.); (I.D.)
| | - Tony Schmidt
- Gottfried Schatz Research Centre, Medical University of Graz, A-8010 Graz, Austria; (L.W.); (R.S.); (T.S.)
| | - Verena Handl
- Department of Neurosurgery, Medical University of Graz, A-8010 Graz, Austria; (V.H.); (M.Ü.)
| | - Peter Sagmeister
- Institute of Chemistry, University of Graz, Heinrichstraße 28, A-8010 Graz, Austria; (P.S.); (M.K.)
| | - Manuel Köckinger
- Institute of Chemistry, University of Graz, Heinrichstraße 28, A-8010 Graz, Austria; (P.S.); (M.K.)
| | - Isabella Derler
- Institute of Biophysics, JKU Life Science Centre, Johannes Kepler University Linz, A-4020 Linz, Austria; (A.T.); (M.S.); (I.F.); (I.D.)
| | - Muammer Üçal
- Department of Neurosurgery, Medical University of Graz, A-8010 Graz, Austria; (V.H.); (M.Ü.)
| | - Daniel Bonhenry
- Centre for Nanobiology and Structural Biology, Academy of Sciences of the Czech Republic, 373 33 Nové Hrady, Czech Republic;
| | - Silke Patz
- Department of Neurosurgery, Medical University of Graz, A-8010 Graz, Austria; (V.H.); (M.Ü.)
| | - Rainer Schindl
- Gottfried Schatz Research Centre, Medical University of Graz, A-8010 Graz, Austria; (L.W.); (R.S.); (T.S.)
- Institute of Biophysics, JKU Life Science Centre, Johannes Kepler University Linz, A-4020 Linz, Austria; (A.T.); (M.S.); (I.F.); (I.D.)
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Su J, Marrink SJ, Melo MN. Localization Preference of Antimicrobial Peptides on Liquid-Disordered Membrane Domains. Front Cell Dev Biol 2020; 8:350. [PMID: 32509780 PMCID: PMC7248343 DOI: 10.3389/fcell.2020.00350] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 04/20/2020] [Indexed: 01/14/2023] Open
Abstract
We performed coarse-grained simulations of the antimicrobial peptides Magainin-2, BP100, MSI-103, and MSI-78 on a phase-separated membrane to study their preference for the different domains. All the peptides displayed a clear preference for the liquid-disordered (Ld) phase over the liquid-ordered (Lo) one. For BP100, MSI-103, and MSI-78 there was a further preference of the peptides for the domain interface. The peptides' preference toward the disordered phase was shown to reflect a penalization of lipid-lipid interaction enthalpy in the Lo phase, when in the vicinity of peptides. Similar results were observed at the two studied concentrations, although Ld phase saturation at the higher concentration drove some of the peptide excess to the Lo phase. Magainin-2 and MSI-103 were found to dimerize, in agreement with available experimental data. Interestingly, at high concentrations of Magainin-2 toroidal pores spontaneously formed in the Ld phase. We performed additional simulations to characterize this phenomenon, which is likely related to Magainin-2's membranolytic action.
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Affiliation(s)
- Juanjuan Su
- Molecular Dynamics Group, Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials, University of Groningen, Groningen, Netherlands
| | - Siewert J. Marrink
- Molecular Dynamics Group, Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials, University of Groningen, Groningen, Netherlands
| | - Manuel N. Melo
- Multiscale Modeling Lab, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
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29
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Rauter MT, Galteland O, Erdős M, Moultos OA, Vlugt TJH, Schnell SK, Bedeaux D, Kjelstrup S. Two-Phase Equilibrium Conditions in Nano pores. Nanomaterials (Basel) 2020; 10:nano10040608. [PMID: 32224924 PMCID: PMC7221961 DOI: 10.3390/nano10040608] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 03/20/2020] [Accepted: 03/21/2020] [Indexed: 11/16/2022]
Abstract
It is known that thermodynamic properties of a system change upon confinement. To know how, is important for modelling of porous media. We propose to use Hill's systematic thermodynamic analysis of confined systems to describe two-phase equilibrium in a nanopore. The integral pressure, as defined by the compression energy of a small volume, is then central. We show that the integral pressure is constant along a slit pore with a liquid and vapor in equilibrium, when Young and Young-Laplace's laws apply. The integral pressure of a bulk fluid in a slit pore at mechanical equilibrium can be understood as the average tangential pressure inside the pore. The pressure at mechanical equilibrium, now named differential pressure, is the average of the trace of the mechanical pressure tensor divided by three as before. Using molecular dynamics simulations, we computed the integral and differential pressures, p ^ and p, respectively, analysing the data with a growing-core methodology. The value of the bulk pressure was confirmed by Gibbs ensemble Monte Carlo simulations. The pressure difference times the volume, V, is the subdivision potential of Hill, ( p - p ^ ) V = ϵ . The combined simulation results confirm that the integral pressure is constant along the pore, and that ϵ / V scales with the inverse pore width. This scaling law will be useful for prediction of thermodynamic properties of confined systems in more complicated geometries.
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Affiliation(s)
- Michael T. Rauter
- PoreLab, Department of Chemistry, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway; (O.G.); (D.B.); (S.K.)
- Correspondence:
| | - Olav Galteland
- PoreLab, Department of Chemistry, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway; (O.G.); (D.B.); (S.K.)
| | - Máté Erdős
- Engineering Thermodynamics, Process and Energy Department, Delft University of Technology, Leeghwaterstraat 39, 2628CB Delft, The Netherlands; (M.E.); (O.A.M.); (T.J.H.V.)
| | - Othonas A. Moultos
- Engineering Thermodynamics, Process and Energy Department, Delft University of Technology, Leeghwaterstraat 39, 2628CB Delft, The Netherlands; (M.E.); (O.A.M.); (T.J.H.V.)
| | - Thijs J. H. Vlugt
- Engineering Thermodynamics, Process and Energy Department, Delft University of Technology, Leeghwaterstraat 39, 2628CB Delft, The Netherlands; (M.E.); (O.A.M.); (T.J.H.V.)
| | - Sondre K. Schnell
- Department of Materials Science and Engineering, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway;
| | - Dick Bedeaux
- PoreLab, Department of Chemistry, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway; (O.G.); (D.B.); (S.K.)
| | - Signe Kjelstrup
- PoreLab, Department of Chemistry, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway; (O.G.); (D.B.); (S.K.)
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30
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Leem S, Chang J, Kim Y, Shin JG, Song HJ, Lee SG, Yoo S, Lee J, Myoung J, Park SG, Kang NG. Repeated measurements of facial skin characteristics using the Janus-Ⅲ measurement system. Skin Res Technol 2019; 26:362-368. [PMID: 31859440 DOI: 10.1111/srt.12811] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 09/08/2019] [Accepted: 11/09/2019] [Indexed: 01/07/2023]
Abstract
BACKGROUND For personalized skin care, noninvasive quantitative methods to evaluate facial skin characteristics are important. Janus-III is one of the most widely used imaging analysis devices in the skin care industry in Korea. Janus-III generates values for a range of skin characteristics. Due to the convenience of obtaining results for a variety of skin characteristics in a single measurement, the use of Janus-III in cosmetic stores and research institutes has been recently increasing. However, the consistency of skin measurements of Janus-III has not been elucidated yet. MATERIALS AND METHODS In this study, we repeated skin measurements three times for 70 different subjects and compared each numerical value in order to assess the consistency of the Janus-III. For this purpose, we compared between-sample distances and within-sample distances. RESULTS We found important patterns for future analyses in terms of consistency. First, the average values of skin measurement categories were more reliable than individual part values of facial segments. Second, center part values such as forehead and nose were more reliable than side part values such as left and right part segments. CONCLUSION If researchers who use Janus-III for studies of facial characteristics analyze average and center part values first, they can obtain relatively reliable patterns of facial skin characteristics.
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Affiliation(s)
- Sangseob Leem
- R&D Center, LG Household and Health Care, Ltd., Seoul, Korea
| | - Junghwa Chang
- R&D Center, LG Household and Health Care, Ltd., Seoul, Korea
| | - Yunkwan Kim
- R&D Center, LG Household and Health Care, Ltd., Seoul, Korea
| | - Joong-Gon Shin
- R&D Center, LG Household and Health Care, Ltd., Seoul, Korea
| | - Hae Jung Song
- R&D Center, LG Household and Health Care, Ltd., Seoul, Korea
| | - Seo-Gyeong Lee
- R&D Center, LG Household and Health Care, Ltd., Seoul, Korea
| | - Suji Yoo
- R&D Center, LG Household and Health Care, Ltd., Seoul, Korea
| | - Jinyong Lee
- R&D Center, LG Household and Health Care, Ltd., Seoul, Korea
| | - Joonoh Myoung
- R&D Center, LG Household and Health Care, Ltd., Seoul, Korea
| | - Sun Gyoo Park
- R&D Center, LG Household and Health Care, Ltd., Seoul, Korea
| | - Nae Gyu Kang
- R&D Center, LG Household and Health Care, Ltd., Seoul, Korea
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31
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Mikkola R, Andersson M, Kharechkina E, Kruglova S, Kruglov A. Fusaricidin-Type Compounds Create Pores in Mitochondrial and Plasma Membranes of Mammalian Cells. Biomolecules 2019; 9:biom9090433. [PMID: 31480526 PMCID: PMC6770722 DOI: 10.3390/biom9090433] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Revised: 08/29/2019] [Accepted: 08/29/2019] [Indexed: 12/12/2022] Open
Abstract
Fusaricidins and related LI-F compounds are effective bactericides and fungicides. Recently, we have found that they are highly toxic to mammalian cells. Here, we studied the effect of fusaricidin-type compounds (FTCs) on the membranes of mammalian cells. Ethanol extracts from Paenibacillus polymyxa strains, RS10 and I/Sim, were fractionated and analyzed by HPLC and mass spectrometry. The effects of FTCs on mitochondrial functions and integrity were studied by standard methods: measurements of swelling, membrane potential (ΔΨm), respiration rate, cytochrome c release, and pore sizes. Superoxide flashes were registered by 3,7-dihydro-2-methyl-6-(4-methoxyphenyl)imidazol[1,2-a]pyrazine-3-one (MCLA). Plasma membrane permeability was assessed by propidium iodide (PI) staining and ATP release. FTCs caused the permeabilization of the inner mitochondria membrane (IMM) to ions and low-molecular-weight (~750 Da) solutes. The permeabilization did not depend on the permeability transition pore (mPTP) but was strongly dependent on ΔΨm. Fusaricidins A plus B, LI-F05a, and LI-F05b-LI-F07b permeabilized IMM with comparable efficiency. They created pores and affected mitochondrial functions and integrity similarly to mPTP opening. They permeabilized the sperm cell plasma membrane to ATP and PI. Thus, the formation of pores in polarized membranes underlays the toxicity of FTCs to mammals. Besides, FTCs appeared to be superior reference compounds for mPTP studies.
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Affiliation(s)
- Raimo Mikkola
- Department of Civil Engineering, School of Engineering, Aalto University, 00076 Aalto, Finland
| | - Maria Andersson
- Department of Civil Engineering, School of Engineering, Aalto University, 00076 Aalto, Finland
| | - Ekaterina Kharechkina
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, 142292 Moscow Region, Russia
| | - Svetlana Kruglova
- Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, 142292 Moscow Region, Russia
| | - Alexey Kruglov
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, 142292 Moscow Region, Russia.
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Cáceres B, Ramirez A, Carrillo E, Jimenez G, Griñán-Lisón C, López-Ruiz E, Jiménez-Martínez Y, Marchal JA, Boulaiz H. Deciphering the Mechanism of Action Involved in Enhanced Suicide Gene Colon Cancer Cell Killer Effect Mediated by Gef and Apoptin. Cancers (Basel) 2019; 11:cancers11020264. [PMID: 30813432 PMCID: PMC6406936 DOI: 10.3390/cancers11020264] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 02/20/2019] [Accepted: 02/20/2019] [Indexed: 12/24/2022] Open
Abstract
Despite the great advances in cancer treatment, colorectal cancer has emerged as the second highest cause of death from cancer worldwide. For this type of tumor, the use of suicide gene therapy could represent a novel therapy. We recently demonstrated that co-expression of gef and apoptin dramatically inhibits proliferation of the DLD-1 colon cell line. In the present manuscript, we try to establish the mechanism underlying the enhanced induction of apoptosis by triggering both gef and apoptin expression in colon tumor cells. Scanning microscopy reveals that simultaneous expression of gef and apoptin induces the apparition of many "pores" in the cytoplasmic membrane not detected in control cell lines. The formation of pores induced by the gef gene and accentuated by apoptin results in cell death by necrosis. Moreover, we observed the presence of apoptotic cells. Performing protein expression analysis using western blot, we revealed an activation of mitochondrial apoptosis (increased expression of Pp53, cytochrome c, Bax, and caspase 9) and also the involvement of the extrinsic pathway through caspase 8activation. In conclusion, in this manuscript we demonstrate for the first time that the extrinsic pathway of apoptosis and pore formation is also involved in the cell death caused by the co-expression of the gef and apoptin genes. Our results suggest that co-expression of gef and apoptin genes induces an increase in post-apoptotic necrotic cell death and could be a valuable tool in the design of new antitumor strategies focused on the enhancement of the immune response against cancer cell death.
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Affiliation(s)
- Blanca Cáceres
- Motril Health Center, Hospital Santa Ana, Motril, 18600 Granada, Spain.
| | - Alberto Ramirez
- Biopathology and Medicine Regenerative Institute (IBIMER), University of Granada, 18016 Granada, Spain.
- Biosanitary Institute of Granada (ibs. GRANADA), SAS-Universidad de Granada, 18016 Granada, Spain.
| | - Esmeralda Carrillo
- Biopathology and Medicine Regenerative Institute (IBIMER), University of Granada, 18016 Granada, Spain.
- Biosanitary Institute of Granada (ibs. GRANADA), SAS-Universidad de Granada, 18016 Granada, Spain.
- Department of Human Anatomy and Embryology, University of Granada, 18016 Granada, Spain.
- Research Unit "Modeling Nature" (MNat), University of Granada, 18016 Granada, Spain.
| | - Gema Jimenez
- Biopathology and Medicine Regenerative Institute (IBIMER), University of Granada, 18016 Granada, Spain.
- Biosanitary Institute of Granada (ibs. GRANADA), SAS-Universidad de Granada, 18016 Granada, Spain.
- Research Unit "Modeling Nature" (MNat), University of Granada, 18016 Granada, Spain.
| | - Carmen Griñán-Lisón
- Biopathology and Medicine Regenerative Institute (IBIMER), University of Granada, 18016 Granada, Spain.
- Biosanitary Institute of Granada (ibs. GRANADA), SAS-Universidad de Granada, 18016 Granada, Spain.
- Research Unit "Modeling Nature" (MNat), University of Granada, 18016 Granada, Spain.
| | - Elena López-Ruiz
- Biopathology and Medicine Regenerative Institute (IBIMER), University of Granada, 18016 Granada, Spain.
- Biosanitary Institute of Granada (ibs. GRANADA), SAS-Universidad de Granada, 18016 Granada, Spain.
- Research Unit "Modeling Nature" (MNat), University of Granada, 18016 Granada, Spain.
- Department of Health Sciences, University of Jaén, E-23071 Jaén, Spain.
| | - Yaiza Jiménez-Martínez
- Biopathology and Medicine Regenerative Institute (IBIMER), University of Granada, 18016 Granada, Spain.
- Biosanitary Institute of Granada (ibs. GRANADA), SAS-Universidad de Granada, 18016 Granada, Spain.
- Research Unit "Modeling Nature" (MNat), University of Granada, 18016 Granada, Spain.
| | - Juan A Marchal
- Biopathology and Medicine Regenerative Institute (IBIMER), University of Granada, 18016 Granada, Spain.
- Biosanitary Institute of Granada (ibs. GRANADA), SAS-Universidad de Granada, 18016 Granada, Spain.
- Department of Human Anatomy and Embryology, University of Granada, 18016 Granada, Spain.
- Research Unit "Modeling Nature" (MNat), University of Granada, 18016 Granada, Spain.
| | - Houria Boulaiz
- Biopathology and Medicine Regenerative Institute (IBIMER), University of Granada, 18016 Granada, Spain.
- Biosanitary Institute of Granada (ibs. GRANADA), SAS-Universidad de Granada, 18016 Granada, Spain.
- Department of Human Anatomy and Embryology, University of Granada, 18016 Granada, Spain.
- Research Unit "Modeling Nature" (MNat), University of Granada, 18016 Granada, Spain.
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Fonseca BB, Silva PLAPA, Silva ACA, Dantas NO, de Paula AT, Olivieri OCL, Beletti ME, Rossi DA, Goulart LR. Nanocomposite of Ag-Doped ZnO and AgO Nanocrystals as a Preventive Measure to Control Biofilm Formation in Eggshell and Salmonella spp. Entry Into Eggs. Front Microbiol 2019; 10:217. [PMID: 30837963 PMCID: PMC6389690 DOI: 10.3389/fmicb.2019.00217] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Accepted: 01/25/2019] [Indexed: 01/24/2023] Open
Abstract
Salmonella spp. is an important foodborne agent of salmonellosis, whose sources in humans often include products of avian origin. The control of this bacterium is difficult especially when Salmonella spp. is organized into biofilms. We hypothesized that the novel nanocomposites of ZnO nanocrystals doped with silver (Ag) and silver oxide (AgO) nanocrystals (ZnO:Ag-AgO) synthesized by the coprecipitation method could control or prevent the formation of Salmonella Enteritidis (SE) and Salmonella Heidelberg (SH) biofilm and its entry into turkey eggs. The diffraction characteristics of ZnO and AgO showed sizes of 28 and 30 nm, respectively. The Zn to Ag substitution into the ZnO crystalline structure was evidenced by the ionic radius of Ag+2 (1.26 Å), which is greater than Zn+2 (0.74 Å). For the SE analyses post-biofilm formation, the ZnO:Ag-AgO was not able to eliminate the biofilm, but the bacterial load was lower than that of the control group. Additionally, SE was able to infiltrate into the eggs and was found in both albumen and yolk. For the SH analyses applied onto the eggshells before biofilm formation, the ZnO:Ag-AgO treatment prevented biofilm formation, and although the bacterium infiltration into the eggs was observed in all treated groups, it was significantly smaller in ZnO:Ag-AgO pre-treated eggs, and SH could not reach the yolk. There was no difference in pore size between groups; therefore, the inhibition of biofilm formation and the prevention of bacterium entry into the egg were attributable to the use of ZnO:Ag-AgO, which was not influenced by the egg structure. Although the amount of Ag and Zn in the shell of the ZnO:Ag-AgO group was greater in relation to the control, this difference was not detected in the other egg components. In the search for new measures that are effective, safe and viable for controlling microorganisms in poultry farming, the application of a nanocomposite of Ag-doped ZnO and AgO nanocrystals appears as an alternative of great potential to prevent Salmonella sp biofilms in eggshells and other surfaces.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Luiz Ricardo Goulart
- Institute of Biotechnology, Federal University of Uberlândia, Uberlândia, Brazil
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34
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Xu W, Lin K, Ye D, Jiang X, Liu J, Chen Y. Performance of Toluene Removal in a Nonthermal Plasma Catalysis System over Flake-Like HZSM-5 Zeolite with Tunable Pore Size and Evaluation of Its Byproducts. Nanomaterials (Basel) 2019; 9:E290. [PMID: 30791415 DOI: 10.3390/nano9020290] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 02/10/2019] [Accepted: 02/13/2019] [Indexed: 11/18/2022]
Abstract
In this study, a series of HZSM-5 catalysts were prepared by the chemical liquid-phase deposition method, and low concentration toluene degradation was carried out in an atmospheric pressure dielectric barrier discharge (DBD) reactor. The catalysts were characterized by X-ray powder diffraction (XRD), SEM, TEM, and N2 adsorption analysis techniques. In addition, several organic contaminants were used to evaluate the adsorption performance of the prepared catalysts, and the effect of pore size on the removal efficiency of toluene and byproduct formation was also investigated. The unmodified HZSM-5 zeolite (Z0) exhibited good performance in toluene removal and CO2 selectivity due to the diffusion resistance of ozone and the amounts of active species (OH• and O•). Meanwhile, the time of flight mass spectrometry (TOF-MS) result showed that there were more byproducts of the benzene ring in the gas phase under the action of small micropore size catalysts. Moreover, the surface byproducts were detected by gas chromatography–mass spectrometry (GC-MS).
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35
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Zhao Q, Zhou H, Li X, Xiao B. The mechanosensitive Piezo1 channel: a three-bladed propeller-like structure and a lever-like mechanogating mechanism. FEBS J 2018; 286:2461-2470. [PMID: 30500111 DOI: 10.1111/febs.14711] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 11/27/2018] [Indexed: 01/24/2023]
Abstract
The evolutionarily conserved Piezo proteins, including Piezo1 and Piezo2, constitute a bona fide class of mechanosensitive (MS) cation channels, which play critical roles in various mammalian physiologies, including sensation of touch, proprioception and regulation of vascular development, and blood pressure. Furthermore, mutations in Piezos have been linked to various human genetic diseases, validating their potential as therapeutic targets. Thus, it is pivotal to understand how Piezo channels effectively convert mechanical force into selective cation permeation, and therefore precisely control the various mechanotransduction processes. On the basis of our recently determined cryoelectron microscopy structures of the full-length 2547-residue mouse Piezo1, structure-guided mutagenesis, and electrophysiological and pharmacological characterizations, here we focus on reviewing the key structural features and functional components that enable Piezo1 to employ a lever-like mechanogating mechanism to function as a sophisticated mechanotransduction channel.
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Affiliation(s)
- Qiancheng Zhao
- State Key Laboratory of Membrane Biology, School of Pharmaceutical Sciences, Tsinghua University, Beijing, China.,Tsinghua-Peking Joint Center for Life Sciences, School of Pharmaceutical Sciences, Tsinghua University, Beijing, China.,IDG/McGovern Institute for Brain Research, School of Pharmaceutical Sciences or Life Sciences, Tsinghua University, Beijing, China
| | - Heng Zhou
- Tsinghua-Peking Joint Center for Life Sciences, School of Pharmaceutical Sciences, Tsinghua University, Beijing, China
| | - Xueming Li
- Tsinghua-Peking Joint Center for Life Sciences, School of Pharmaceutical Sciences, Tsinghua University, Beijing, China
| | - Bailong Xiao
- State Key Laboratory of Membrane Biology, School of Pharmaceutical Sciences, Tsinghua University, Beijing, China.,Tsinghua-Peking Joint Center for Life Sciences, School of Pharmaceutical Sciences, Tsinghua University, Beijing, China.,IDG/McGovern Institute for Brain Research, School of Pharmaceutical Sciences or Life Sciences, Tsinghua University, Beijing, China
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36
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Abstract
Dialyzers were initially developed for diffusive clearance of uraemic toxins. Diffusion most effectively clears small uncharged solutes from plasma water, such as urea. Sessional urea clearance targets have been shown to be important for short-term patient survival, but over the longer term, although low-flux dialysis can prolong patient survival, accumulation of middle-sized uraemic toxins, such as β2 microglobulin can lead to disabling arthropathy. Although the introduction of high-flux dialyzers, designed to increase β2 microglobulin clearance, has reduced the prevalence of arthropathy; this has not been translated into a demonstrable significant improvement in patient survival. However, analysis of individual patients recruited into trials of haemo-diafiltration reported that greater convective clearance was associated with better survival, although the individual trials reported mixed outcomes. Most haemodiafiltration trials were not designed to study the effect of convective dose, so although reported patient survival was greater for those receiving greater convective volume exchange, these results could potentially be confounded by patient or center effects. An alternative approach to increasing middle-sized solute clearances would be to use more permeable dialyzers, but as yet there are no trials reporting survival with larger cutoff dialyzers. As such, although there is increasing evidence that increasing middle-sized molecular uraemic solute clearance is associated with improved patient survival, further prospective trials are required to determine whether as with Kt/Vurea there is a threshold effect of how much convective or middle-sized solute clearance is required to improve patient survival.
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Affiliation(s)
- Andrew Davenport
- UCL Centre for Nephrology, Royal Free Hospital, University College London Medical School, London, United Kingdom
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37
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Abstract
In the last three decades, all efforts in bone tissue engineering were driven by the dogma that the ideal pore size in bone substitutes lies between 0.3 and 0.5 mm in diameter. Newly developed additive manufacturing methodologies for ceramics facilitate the total control over pore size, pore distribution, bottleneck size, and bottleneck distribution. Therefore, this appears to be the method of choice with which to test the aforementioned characteristics of an ideal bone substitute. To this end, we produced a library of 15 scaffolds with diverse defined pore/bottleneck dimensions and distributions, tested them in vivo in a calvarial bone defect model in rabbits, and assessed the clinically most relevant parameters: defect bridging and bony regenerated area. Our in vivo data revealed that the ideal pore/bottleneck dimension for bone substitutes is in the range of 0.7-1.2 mm, and appears therefore to be twofold to fourfold more extended than previously thought. Pore/bottleneck dimensions of 1.5 and 1.7 mm perform significantly worse and appear unsuitable in bone substitutes. Thus, our results set the ideal range of pore/bottleneck dimensions and are likely to have a significant impact on the microarchitectural design of future bone substitutes for use in orthopedic, trauma, cranio-maxillofacial and oral surgery.
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Affiliation(s)
- Chafik Ghayor
- Oral Biotechnology and Bioengineering, Department of Cranio-Maxillofacial and Oral Surgery, Center for Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Franz E. Weber
- Oral Biotechnology and Bioengineering, Department of Cranio-Maxillofacial and Oral Surgery, Center for Dental Medicine, University of Zurich, Zurich, Switzerland
- Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
- Center for Applied Biotechnology and Molecular Medicine, University of Zurich, Zurich, Switzerland
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Wu J, Young M, Lewis AH, Martfeld AN, Kalmeta B, Grandl J. Inactivation of Mechanically Activated Piezo1 Ion Channels Is Determined by the C-Terminal Extracellular Domain and the Inner Pore Helix. Cell Rep 2018; 21:2357-2366. [PMID: 29186675 PMCID: PMC5938756 DOI: 10.1016/j.celrep.2017.10.120] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 10/07/2017] [Accepted: 10/30/2017] [Indexed: 12/19/2022] Open
Abstract
Piezo proteins form mechanically activated ion channels that are responsible for our sense of light touch, proprioception, and vascular blood flow. Upon activation by mechanical stimuli, Piezo channels rapidly inactivate in a voltage-dependent manner through an unknown mechanism. Inactivation of Piezo channels is physiologically important, as it modulates overall mechanical sensitivity, gives rise to frequency filtering of repetitive mechanical stimuli, and is itself the target of numerous human disease-related channelopathies that are not well understood mechanistically. Here, we identify the globular C-terminal extracellular domain as a structure that is sufficient to confer the time course of inactivation and a single positively charged lysine residue at the adjacent inner pore helix as being required for its voltage dependence. Our results are consistent with a mechanism for inactivation that is mediated through voltage-dependent conformations of the inner pore helix and allosteric coupling with the C-terminal extracellular domain.
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Affiliation(s)
- Jason Wu
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Michael Young
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Amanda H Lewis
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Ashley N Martfeld
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Breanna Kalmeta
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Jörg Grandl
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA.
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Shi S, Mutchler SM, Blobner BM, Kashlan OB, Kleyman TR. Pore-lining residues of MEC-4 and MEC-10 channel subunits tune the Caenorhabditis elegans degenerin channel's response to shear stress. J Biol Chem 2018; 293:10757-10766. [PMID: 29743244 DOI: 10.1074/jbc.ra118.002499] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 05/08/2018] [Indexed: 12/20/2022] Open
Abstract
The Caenorhabditis elegans MEC-4/MEC-10 channel mediates the worm's response to gentle body touch and is activated by laminar shear stress (LSS) when expressed in Xenopus oocytes. Substitutions at multiple sites within the second transmembrane domain (TM2) of MEC-4 or MEC-10 abolish the gentle touch response in worms, but the roles of these residues in mechanosensing are unclear. The present study therefore examined the role of specific MEC-4 and MEC-10 TM2 residues in the channel's response to LSS. We found that introducing mutations within the TM2 of MEC-4 or MEC-10 not only altered channel activity, but also affected the channel's response to LSS. This response was enhanced by Cys substitutions at selected MEC-4 sites (Phe715, Gly716, Gln718, and Leu719) between the degenerin and the putative amiloride-binding sites in this subunit. In contrast, the LSS response was largely blunted in MEC-10 variants bearing single Cys substitutions in the regions preceding and following the amiloride-binding site (Gly677-Leu681), as well as with four MEC-10 touch-deficient mutations that introduced charged residues into the TM2 domain. An enhanced response to LSS was observed with a MEC-10 mutation in the putative selectivity filter. Overall, MEC-4 or MEC-10 mutants that altered the channel's LSS response are primarily clustered between the degenerin site and the selectivity filter, a region that probably forms the narrowest portion of the channel pore. Our results suggest that pore-lining residues of MEC-4 and MEC-10 have important yet different roles in tuning the channel's response to mechanical forces.
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Affiliation(s)
- Shujie Shi
- From the Renal-Electrolyte Division, Department of Medicine
| | - Stephanie M Mutchler
- From the Renal-Electrolyte Division, Department of Medicine.,Department of Pharmacology and Chemical Biology, and
| | | | - Ossama B Kashlan
- From the Renal-Electrolyte Division, Department of Medicine.,Department of Computational and Systems Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
| | - Thomas R Kleyman
- From the Renal-Electrolyte Division, Department of Medicine, .,Department of Pharmacology and Chemical Biology, and.,Department of Cell Biology
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40
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Wang X, Shu X, Li Z, Huo W, Zou L, Tang Y, Li L. Comparison of two kinds of skin imaging analysis software: VISIA ® from Canfield and IPP ® from Media Cybernetics. Skin Res Technol 2018; 24:379-385. [PMID: 29377397 DOI: 10.1111/srt.12440] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/04/2018] [Indexed: 02/05/2023]
Abstract
BACKGROUND Skin imaging analysis, acting as a supplement to noninvasive bioengineering devices, has been widely used in medical cosmetology and cosmetic product evaluation. The main aim of this study is to assess the differences and correlations in measuring skin spots, wrinkles, vascular features, porphyrin, and pore between two commercially available image analysis software. MATERIALS AND METHODS Seventy healthy women were included in the study. Before taking pictures, the dermatologist evaluated subjects' skin conditions. Test sites included the forehead, cheek, and periorbital skin. A 2 × 2 cm cardboard was used to make a mark on the skin surface. Pictures were taken using VISIA® under three kinds light conditions and analyzed using VISIA® and IPP® respectively. RESULTS (1) Skin pore, red area, ultraviolet spot, brown spot, porphyrin, and wrinkle measured with VISIA® were correlated with those measured with IPP® (P < .01). (2) Spot, wrinkle, fine line, brown spot, and red area analyzed with VISIA® were correlated with age on the forehead and periorbital skin (P < .05). L-value, Crow's feet, ultraviolet spot, brown spot, and red area analyzed with IPP® were correlated with age on the periorbital skin (P < .05). (3) L-value, spot, wrinkle, fine line, porphyrin, red area, and pore analyzed with VISIA® and IPP® showed correlations with the subjective evaluation scores (P < .05). CONCLUSIONS VISIA® and IPP® showed acceptable correlation in measuring various skin conditions. VISIA® showed a high sensibility when measured on the forehead skin. IPP® is available as an alternative software program to evaluate skin features.
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Affiliation(s)
- X Wang
- Department of Dermatology, West China Hospital, Sichuan University, Chengdu, China
| | - X Shu
- Cosmetics Evaluation Center, West China Hospital, Sichuan University, Chengdu, China
| | - Z Li
- Cosmetics Evaluation Center, West China Hospital, Sichuan University, Chengdu, China
| | - W Huo
- Cosmetics Evaluation Center, West China Hospital, Sichuan University, Chengdu, China
| | - L Zou
- Cosmetics Evaluation Center, West China Hospital, Sichuan University, Chengdu, China
| | - Y Tang
- Cosmetics Evaluation Center, West China Hospital, Sichuan University, Chengdu, China
| | - L Li
- Department of Dermatology, West China Hospital, Sichuan University, Chengdu, China
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41
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Zondervan NA, van Dam JCJ, Schaap PJ, Martins Dos Santos VAP, Suarez-Diez M. Regulation of Three Virulence Strategies of Mycobacterium tuberculosis: A Success Story. Int J Mol Sci 2018; 19:E347. [PMID: 29364195 PMCID: PMC5855569 DOI: 10.3390/ijms19020347] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 01/19/2018] [Accepted: 01/21/2018] [Indexed: 12/28/2022] Open
Abstract
Tuberculosis remains one of the deadliest diseases. Emergence of drug-resistant and multidrug-resistant M. tuberculosis strains makes treating tuberculosis increasingly challenging. In order to develop novel intervention strategies, detailed understanding of the molecular mechanisms behind the success of this pathogen is required. Here, we review recent literature to provide a systems level overview of the molecular and cellular components involved in divalent metal homeostasis and their role in regulating the three main virulence strategies of M. tuberculosis: immune modulation, dormancy and phagosomal rupture. We provide a visual and modular overview of these components and their regulation. Our analysis identified a single regulatory cascade for these three virulence strategies that respond to limited availability of divalent metals in the phagosome.
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Affiliation(s)
- Niels A Zondervan
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
| | - Jesse C J van Dam
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
| | - Peter J Schaap
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
| | - Vitor A P Martins Dos Santos
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
- LifeGlimmer GmbH, Markelstrasse 38, 12163 Berlin, Germany.
| | - Maria Suarez-Diez
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
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42
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Braun S, Pokorná Š, Šachl R, Hof M, Heerklotz H, Hoernke M. Biomembrane Permeabilization: Statistics of Individual Leakage Events Harmonize the Interpretation of Vesicle Leakage. ACS Nano 2018; 12:813-819. [PMID: 29244483 DOI: 10.1021/acsnano.7b08184] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The mode of action of membrane-active molecules, such as antimicrobial, anticancer, cell penetrating, and fusion peptides and their synthetic mimics, transfection agents, drug permeation enhancers, and biological signaling molecules (e.g., quorum sensing), involves either the general or local destabilization of the target membrane or the formation of defined, rather stable pores. Some effects aim at killing the cell, while others need to be limited in space and time to avoid serious damage. Biological tests reveal translocation of compounds and cell death but do not provide a detailed, mechanistic, and quantitative understanding of the modes of action and their molecular basis. Model membrane studies of membrane leakage have been used for decades to tackle this issue, but their interpretation in terms of biology has remained challenging and often quite limited. Here we compare two recent, powerful protocols to study model membrane leakage: the microscopic detection of dye influx into giant liposomes and time-correlated single photon counting experiments to characterize dye efflux from large unilamellar vesicles. A statistical treatment of both data sets does not only harmonize apparent discrepancies but also makes us aware of principal issues that have been confusing the interpretation of model membrane leakage data so far. Moreover, our study reveals a fundamental difference between nano- and microscale systems that needs to be taken into account when conclusions about microscale objects, such as cells, are drawn from nanoscale models.
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Affiliation(s)
- Stefan Braun
- Department of Pharmaceutical Technology and Biopharmacy, University of Freiburg , 79104 Freiburg im Breisgau, Germany
| | - Šárka Pokorná
- Department of Biophysical Chemistry, J. Heyrovský Institute of Physical Chemistry of the Academy of Sciences of the Czech Republic , 182 23 Prague, Czech Republic
| | - Radek Šachl
- Department of Biophysical Chemistry, J. Heyrovský Institute of Physical Chemistry of the Academy of Sciences of the Czech Republic , 182 23 Prague, Czech Republic
| | - Martin Hof
- Department of Biophysical Chemistry, J. Heyrovský Institute of Physical Chemistry of the Academy of Sciences of the Czech Republic , 182 23 Prague, Czech Republic
| | - Heiko Heerklotz
- Department of Pharmaceutical Technology and Biopharmacy, University of Freiburg , 79104 Freiburg im Breisgau, Germany
- BIOSS Centre for Biological Signalling Studies, University of Freiburg , 79104 Freiburg im Breisgau, Germany
- Leslie Dan Faculty of Pharmacy, University of Toronto , 144 College St., Toronto, Ontario M5S 3M2, Canada
| | - Maria Hoernke
- Department of Pharmaceutical Technology and Biopharmacy, University of Freiburg , 79104 Freiburg im Breisgau, Germany
- BIOSS Centre for Biological Signalling Studies, University of Freiburg , 79104 Freiburg im Breisgau, Germany
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Steinberg X, Kasimova MA, Cabezas-Bratesco D, Galpin JD, Ladron-de-Guevara E, Villa F, Carnevale V, Islas L, Ahern CA, Brauchi SE. Conformational dynamics in TRPV1 channels reported by an encoded coumarin amino acid. eLife 2017; 6:e28626. [PMID: 29206105 PMCID: PMC5716661 DOI: 10.7554/elife.28626] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 10/22/2017] [Indexed: 11/13/2022] Open
Abstract
TRPV1 channels support the detection of noxious and nociceptive input. Currently available functional and structural data suggest that TRPV1 channels have two gates within their permeation pathway: one formed by a 'bundle-crossing' at the intracellular entrance and a second constriction at the selectivity filter. To describe conformational changes associated with channel gating, the fluorescent non-canonical amino acid coumarin-tyrosine was genetically encoded at Y671, a residue proximal to the selectivity filter. Total internal reflection fluorescence microscopy was performed to image the conformational dynamics of the channels in live cells. Photon counts and optical fluctuations from coumarin encoded within TRPV1 tetramers correlates with channel activation by capsaicin, providing an optical marker of conformational dynamics at the selectivity filter. In agreement with the fluorescence data, molecular dynamics simulations display alternating solvent exposure of Y671 in the closed and open states. Overall, the data point to a dynamic selectivity filter that may serve as a gate for permeation.
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Affiliation(s)
- Ximena Steinberg
- Physiology Department, Faculty of MedicineUniversidad Austral de ChileValdiviaChile
| | - Marina A Kasimova
- Institute for Computational Molecular ScienceTemple UniversityPhiladelphiaUnited States
| | | | - Jason D Galpin
- Department of Molecular Physiology and BiophysicsUniversity of IowaIowa CityUnited States
| | - Ernesto Ladron-de-Guevara
- Departamento de Fisiología, Facultad de MedicinaUniversidad Nacional Autónoma de MéxicoCiudad de MéxicoMexico
| | - Federica Villa
- Dipartimento di Elettronica, Informazione e Bioingegneria (DEIB)Politecnico di Milano (POLIMI)MilanoItaly
| | - Vincenzo Carnevale
- Institute for Computational Molecular ScienceTemple UniversityPhiladelphiaUnited States
| | - Leon Islas
- Departamento de Fisiología, Facultad de MedicinaUniversidad Nacional Autónoma de MéxicoCiudad de MéxicoMexico
| | - Christopher A Ahern
- Department of Molecular Physiology and BiophysicsUniversity of IowaIowa CityUnited States
| | - Sebastian E Brauchi
- Physiology Department, Faculty of MedicineUniversidad Austral de ChileValdiviaChile
- Millennium Nucleus of Ion Channels-associated Diseases (MiNICAD)Iniciativa Cientifica MilenioSantiagoChile
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44
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Rathkey JK, Benson BL, Chirieleison SM, Yang J, Xiao TS, Dubyak GR, Huang AY, Abbott DW. Live-cell visualization of gasdermin D-driven pyroptotic cell death. J Biol Chem 2017; 292:14649-14658. [PMID: 28726636 DOI: 10.1074/jbc.m117.797217] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 07/15/2017] [Indexed: 12/19/2022] Open
Abstract
Pyroptosis is a form of cell death important in defenses against pathogens that can also result in a potent and sometimes pathological inflammatory response. During pyroptosis, GSDMD (gasdermin D), the pore-forming effector protein, is cleaved, forms oligomers, and inserts into the membranes of the cell, resulting in rapid cell death. However, the potent cell death induction caused by GSDMD has complicated our ability to understand the biology of this protein. Studies aimed at visualizing GSDMD have relied on expression of GSDMD fragments in epithelial cell lines that naturally lack GSDMD expression and also lack the proteases necessary to cleave GSDMD. In this work, we performed mutagenesis and molecular modeling to strategically place tags and fluorescent proteins within GSDMD that support native pyroptosis and facilitate live-cell imaging of pyroptotic cell death. Here, we demonstrate that these fusion proteins are cleaved by caspases-1 and -11 at Asp-276. Mutations that disrupted the predicted p30-p20 autoinhibitory interface resulted in GSDMD aggregation, supporting the oligomerizing activity of these mutations. Furthermore, we show that these novel GSDMD fusions execute inflammasome-dependent pyroptotic cell death in response to multiple stimuli and allow for visualization of the morphological changes associated with pyroptotic cell death in real time. This work therefore provides new tools that not only expand the molecular understanding of pyroptosis but also enable its direct visualization.
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Affiliation(s)
| | - Bryan L Benson
- From the Department of Pathology.,the Division of Pediatric Hematology-Oncology, Department of Pediatrics, and
| | | | - Jie Yang
- From the Department of Pathology.,the Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106
| | | | - George R Dubyak
- the Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106
| | - Alex Y Huang
- From the Department of Pathology.,the Division of Pediatric Hematology-Oncology, Department of Pediatrics, and
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45
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Linming F, Wei H, Anqi L, Yuanyu C, Heng X, Sushmita P, Yiming L, Li L. Comparison of two skin imaging analysis instruments: The VISIA ® from Canfield vs the ANTERA 3D ® CS from Miravex. Skin Res Technol 2017; 24:3-8. [PMID: 28585335 DOI: 10.1111/srt.12381] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/18/2017] [Indexed: 02/05/2023]
Abstract
BACKGROUND The skin imaging analysis instruments are widely used to record and measure the surface and subsurface skin conditions. The main aim of this study is to reveal the differences and correlations in measuring wrinkle, skin texture, coloration/evenness, vascular features, and pore between two commercially available instruments. METHODS Twenty-eight subjects were enrolled in the study. A 2*2 cm cardboard was used to make sure the two instruments analyze the same area. Pictures were taken and analyzed by the VISIA® from Canfield and the ANTERA 3D® CS from Miravex, in sequence. RESULTS The spot, ultraviolet spot, brown spot, red area, texture values measured with VISIA® were positively correlated with age, while the pore and wrinkle values showed no significance. The wrinkle, texture, melanin, hemoglobin, pore index, pore volume values measured with ANTERA 3D® had a significantly positive correlation with age. The spot, brown spot values from VISIA® were positively correlated with the melanin value from ANTERA 3D® . Texture value measured with the two instruments revealed positive linear correlation. Strong correlation was found between the red area value from VISIA® and the hemoglobin value from ANTERA 3D® . Ultraviolet spot from VISIA® showed no linear correlation with the melanin value from ANTERA 3D® . Neither of the wrinkle and pore measured with the two instruments showed linear correlation. CONCLUSIONS ANTERA 3D® relies on multidirectional illumination obtained by LEDs of different wavelengths from different directions which make it advanced at the qualitative evaluation of various dermatologic conditions. Compared with VISIA® , ANTERA 3D® is more sensitive in the assessment of wrinkle and it may also be available to evaluate the aging-related enlarged pore.
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Affiliation(s)
- F Linming
- Department of Dermatovenereology, West China Hospital, Sichuan University, Chengdu, China
| | - H Wei
- Department of Dermatovenereology, West China Hospital, Sichuan University, Chengdu, China
| | - L Anqi
- Department of Dermatovenereology, West China Hospital, Sichuan University, Chengdu, China
| | - C Yuanyu
- Department of Dermatovenereology, West China Hospital, Sichuan University, Chengdu, China
| | - X Heng
- Department of Dermatovenereology, West China Hospital, Sichuan University, Chengdu, China
| | - P Sushmita
- Department of Dermatovenereology, West China Hospital, Sichuan University, Chengdu, China
| | - L Yiming
- Department of Dermatovenereology, West China Hospital, Sichuan University, Chengdu, China
| | - L Li
- Department of Dermatovenereology, West China Hospital, Sichuan University, Chengdu, China
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Fernández-Marrero Y, Bleicken S, Das KK, Bachmann D, Kaufmann T, Garcia-Saez AJ. The membrane activity of BOK involves formation of large, stable toroidal pores and is promoted by cBID. FEBS J 2017; 284:711-724. [PMID: 28064468 DOI: 10.1111/febs.14008] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 12/19/2016] [Accepted: 01/06/2017] [Indexed: 12/27/2022]
Abstract
The BCL-2 family members are key regulators of the intrinsic apoptotic pathway, which is defined by permeabilization of the mitochondrial outer membrane by members of the BAX-like subfamily. BOK is classified as a BAX-like protein; however, its (patho-)physiological role remains largely unclear. We therefore assessed the membrane permeabilization potential of C-terminally truncated recombinant BOK, BOK∆C . We show that BOK∆C can permeabilize liposomes mimicking the composition of mitochondrial outer membrane, but not of endoplasmic reticulum, forming large and stable pores over time. Importantly, pore formation was enhanced by the presence of cBID and refractory to the addition of antiapoptotic BCL-XL . However, isolated mitochondria from Bax-/- Bak-/- cells were resistant to BOK-induced cytochrome c release, even in the presence of cBID. Taken together, we show that BOK∆C can permeabilize liposomes, and cooperate with cBID, but its role in directly mediating mitochondrial permeabilization is unclear and may underlie a yet to be determined negative regulation.
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Affiliation(s)
| | | | - Kushal Kumar Das
- Interfaculty Institute of Biochemistry, University of Tübingen, Germany
| | | | | | - Ana J Garcia-Saez
- Interfaculty Institute of Biochemistry, University of Tübingen, Germany
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47
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Abstract
A major characteristic of Alzheimer's disease (AD) is the presence of amyloid-β peptide (Aβ) oligomers and aggregates in the brain. It is known that Aβ oligomers interact with the neuronal membrane and induce perforations that cause an influx of calcium ions and enhance the release of synaptic vesicles leading to a delayed synaptic failure by vesicle depletion. To better understand the mechanism by which Aβ exerts its effect on the plasma membrane, we evaluated three Aβ fragments derived from different regions of Aβ(1-42); Aβ(1-28) from the N-terminal region, Aβ(25-35) from the central region, and Aβ(17-42) from the C-terminal region. The neuronal activities of these fragments were examined with patch clamp, immunofluorescence, transmission electron microscopy, aggregation assays, calcium imaging, and MTT reduction assays. The present results indicate that the fragment Aβ(1-28) contributes to aggregation, an increase in intracellular calcium and synaptotoxicity, but is not involved in membrane perforation; Aβ(25-35) is important for membrane perforation, calcium increase, and synaptotoxicity; and Aβ(17-42) induced mitochondrial toxicity similar to the full length Aβ(1-42), but was unable to induce membrane perforation and calcium increase, supporting the idea that it is less toxic in the non-amyloidogenic pathway.
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48
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Abstract
Secretory proteins are conventionally transported through the endoplasmic reticulum to the Golgi and then to the plasma membrane where they are released into the extracellular space. However, numerous substrates also reach these destinations using unconventional pathways. Unconventional protein secretion (UPS) is complex and comprises cargos without a signal peptide or a transmembrane domain that can translocate across the plasma membrane, and cargos that reach the plasma membrane by bypassing the Golgi despite entering the endoplasmic reticulum (ER). With a few exceptions, unconventional secretion is largely triggered by stress. Here I review new results and concepts that are beginning to define these pathways.
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Affiliation(s)
- Catherine Rabouille
- Hubrecht Institute of the KNAW and UMC Utrecht, Utrecht, The Netherlands; Department of Cell Biology, UMC Utrecht, Utrecht, The Netherlands; Department of Cell Biology, UMC Groningen, Groningen, The Netherlands.
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49
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Bode DC, Baker MD, Viles JH. Ion Channel Formation by Amyloid-β42 Oligomers but Not Amyloid-β40 in Cellular Membranes. J Biol Chem 2016; 292:1404-1413. [PMID: 27927987 DOI: 10.1074/jbc.m116.762526] [Citation(s) in RCA: 138] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 11/24/2016] [Indexed: 12/23/2022] Open
Abstract
A central hallmark of Alzheimer's disease is the presence of extracellular amyloid plaques chiefly consisting of amyloid-β (Aβ) peptides in the brain interstitium. Aβ largely exists in two isoforms, 40 and 42 amino acids long, but a large body of evidence points to Aβ(1-42) rather than Aβ(1-40) as the cytotoxic form. One proposed mechanism by which Aβ exerts toxicity is the formation of ion channel pores that disrupt intracellular Ca2+ homeostasis. However, previous studies using membrane mimetics have not identified any notable difference in the channel forming properties between Aβ(1-40) and Aβ(1-42). Here, we tested whether a more physiological environment, membranes excised from HEK293 cells of neuronal origin, would reveal differences in the relative channel forming ability of monomeric, oligomeric, and fibrillar forms of both Aβ(1-40) and Aβ(1-42). Aβ preparations were characterized with transmission electron microscopy and thioflavin T fluorescence. Aβ was then exposed to the extracellular face of excised membranes, and transmembrane currents were monitored using patch clamp. Our data indicated that Aβ(1-42) assemblies in oligomeric preparations form voltage-independent, non-selective ion channels. In contrast, Aβ(1-40) oligomers, fibers, and monomers did not form channels. Ion channel conductance results suggested that Aβ(1-42) oligomers, but not monomers and fibers, formed three distinct pore structures with 1.7-, 2.1-, and 2.4-nm pore diameters. Our findings demonstrate that only Aβ(1-42) contains unique structural features that facilitate membrane insertion and channel formation, now aligning ion channel formation with the differential neurotoxic effect of Aβ(1-40) and Aβ(1-42) in Alzheimer's disease.
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Affiliation(s)
- David C Bode
- From the School of Biological and Chemical Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS, United Kingdom and
| | - Mark D Baker
- the Blizard Institute, Centre for Neuroscience and Trauma, Barts and The London School of Medicine and Dentistry, Queen Mary, University of London, 4 Newark Street, London E1 2AT, United Kingdom
| | - John H Viles
- From the School of Biological and Chemical Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS, United Kingdom and
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50
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Jimah JR, Salinas ND, Sala-Rabanal M, Jones NG, Sibley LD, Nichols CG, Schlesinger PH, Tolia NH. Malaria parasite CelTOS targets the inner leaflet of cell membranes for pore-dependent disruption. eLife 2016; 5. [PMID: 27906127 PMCID: PMC5132341 DOI: 10.7554/elife.20621] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2016] [Accepted: 11/14/2016] [Indexed: 01/02/2023] Open
Abstract
Apicomplexan parasites contain a conserved protein CelTOS that, in malaria parasites, is essential for traversal of cells within the mammalian host and arthropod vector. However, the molecular role of CelTOS is unknown because it lacks sequence similarity to proteins of known function. Here, we determined the crystal structure of CelTOS and discovered CelTOS resembles proteins that bind to and disrupt membranes. In contrast to known membrane disruptors, CelTOS has a distinct architecture, specifically binds phosphatidic acid commonly present within the inner leaflet of plasma membranes, and potently disrupts liposomes composed of phosphatidic acid by forming pores. Microinjection of CelTOS into cells resulted in observable membrane damage. Therefore, CelTOS is unique as it achieves nearly universal inner leaflet cellular activity to enable the exit of parasites from cells during traversal. By providing novel molecular insight into cell traversal by apicomplexan parasites, our work facilitates the design of therapeutics against global pathogens.
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Affiliation(s)
- John R Jimah
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, United States
| | - Nichole D Salinas
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, United States
| | - Monica Sala-Rabanal
- Department of Cell Biology and Physiology, Washington University School of Medicine, Saint Louis, United States.,Center for the Investigation of Membrane Excitability Diseases, Washington University School of Medicine, Saint Louis, United States
| | - Nathaniel G Jones
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, United States
| | - L David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, United States
| | - Colin G Nichols
- Department of Cell Biology and Physiology, Washington University School of Medicine, Saint Louis, United States.,Center for the Investigation of Membrane Excitability Diseases, Washington University School of Medicine, Saint Louis, United States
| | - Paul H Schlesinger
- Department of Cell Biology and Physiology, Washington University School of Medicine, Saint Louis, United States
| | - Niraj H Tolia
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, United States.,Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, United States
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