1
|
Segawa S, Wu J, Kwok RTK, Wong TTW, He X, Tang BZ. Co-aggregation as A Simple Strategy for Preparing Fluorogenic Tetrazine Probes with On-Demand Fluorogen Selection. Angew Chem Int Ed Engl 2024; 63:e202313930. [PMID: 38055202 DOI: 10.1002/anie.202313930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 11/22/2023] [Accepted: 12/01/2023] [Indexed: 12/07/2023]
Abstract
Life science has progressed with applications of fluorescent probes-fluorophores linked to functional units responding to biological events. To meet the varied demands across experiments, simple organic reactions to connect fluorophores and functional units have been developed, enabling the on-demand selection of fluorophore-functional unit combinations. However, organic synthesis requires professional equipment and skills, standing as a daunting task for life scientists. In this study, we present a simple, fast, and convenient strategy for probe preparation: co-aggregation of hydrophobic molecules. We focused on tetrazine-a difficult-to-prepare yet useful functional unit that provides effective bioorthogonal reactivity and strong fluorogenicity. Simply mixing the tetrazine molecules and aggregation-induced emission (AIE) luminogens in water, co-aggregation is induced, and the emission of AIE luminogens is quenched. Subsequent click reaction bioorthogonally turns on the emission, identifying these coaggregates as fluorogenic probes. Thanks to this bioorthogonal fluorogenicity, we established a new time-gated fluorescence bioimaging technique to distinguish overlapping emission signals, enabling multi-organelle imaging with two same-color fluorophores. Our study showcases the potential of this co-aggregation method for the on-demand preparation of fluorescent probes as well as protocols and molecular design principles in this approach, offering an effective solution to evolving needs in life science research.
Collapse
Affiliation(s)
- Shinsuke Segawa
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Institute for Advanced Study, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, 999077, China
- Translational and Advanced Bioimaging Laboratory, Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, 999077, China
| | - Jiajie Wu
- Translational and Advanced Bioimaging Laboratory, Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, 999077, China
| | - Ryan T K Kwok
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Institute for Advanced Study, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, 999077, China
| | - Terence T W Wong
- Translational and Advanced Bioimaging Laboratory, Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, 999077, China
| | - Xuewen He
- The Key Lab of Health Chemistry and Molecular Diagnosis of Suzhou, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren'ai Road, Suzhou, Jiangsu, 215123, China
| | - Ben Zhong Tang
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Institute for Advanced Study, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, 999077, China
- School of Science and Engineering, Shenzhen Institute of Aggregate Science and Technology, The Chinese University of Hong Kong, Shenzhen, Guangdong, 518172, China
| |
Collapse
|
2
|
Gunasekara H, Perera T, Chao CJ, Bruno J, Saed B, Anderson J, Zhao Z, Hu YS. Quantitative Superresolution Imaging of F-Actin in the Cell Body and Cytoskeletal Protrusions Using Phalloidin-Based Single-Molecule Labeling and Localization Microscopy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.04.583337. [PMID: 38496456 PMCID: PMC10942307 DOI: 10.1101/2024.03.04.583337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
We present single-molecule labeling and localization microscopy (SMLLM) using dye-conjugated phalloidin to achieve enhanced superresolution imaging of filamentous actin (F-actin). We demonstrate that the intrinsic phalloidin dissociation enables SMLLM in an imaging buffer containing low concentrations of dye-conjugated phalloidin. We further show enhanced single-molecule labeling by chemically promoting phalloidin dissociation. Two benefits of phalloidin-based SMLLM are better preservation of cellular structures sensitive to mechanical and shear forces during standard sample preparation and more consistent F-actin quantification at the nanoscale. In a proof-of-concept study, we employed SMLLM to super-resolve F-actin structures in U2OS and dendritic cells (DCs) and demonstrate more consistent F-actin quantification in the cell body and structurally delicate cytoskeletal proportions, which we termed membrane fibers, of DCs compared to direct stochastic optical reconstruction microscopy (dSTORM). Using DC2.4 mouse dendritic cells as the model system, we show F-actin redistribution from podosomes to actin filaments and altered prevalence of F-actin-associated membrane fibers on the culture glass surface after lipopolysaccharide exposure. While our work demonstrates SMLLM for F-actin, the concept opens new possibilities for protein-specific single-molecule labeling and localization in the same step using commercially available reagents.
Collapse
Affiliation(s)
- Hirushi Gunasekara
- Department of Chemistry, College of Liberal Arts and Sciences, University of Illinois Chicago, Chicago, IL, 60607, USA
| | - Thilini Perera
- Department of Chemistry, College of Liberal Arts and Sciences, University of Illinois Chicago, Chicago, IL, 60607, USA
| | - Chih-Jia Chao
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Illinois Chicago, Chicago, IL, 60612, USA
| | - Joshua Bruno
- Department of Biological Sciences, College of Liberal Arts and Sciences, University of Illinois Chicago, Chicago, IL, 60607, USA
| | - Badeia Saed
- Department of Chemistry, College of Liberal Arts and Sciences, University of Illinois Chicago, Chicago, IL, 60607, USA
| | - Jesse Anderson
- Department of Chemical Engineering, College of Engineering, University of Illinois Chicago, Chicago, IL, 60607, USA
| | - Zongmin Zhao
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Illinois Chicago, Chicago, IL, 60612, USA
| | - Ying S. Hu
- Department of Chemistry, College of Liberal Arts and Sciences, University of Illinois Chicago, Chicago, IL, 60607, USA
| |
Collapse
|
3
|
Zhao F, Zhang X, Bai F, Lei S, He G, Huang P, Lin J. Maximum Emission Peak Over 1500 nm of Organic Assembly for Blood-Brain Barrier-Crossing NIR-IIb Phototheranostics of Orthotopic Glioblastoma. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2208097. [PMID: 36893436 DOI: 10.1002/adma.202208097] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 02/11/2023] [Indexed: 06/02/2023]
Abstract
The development of blood-brain barrier (BBB)-crossing phototheranostic agents in second near-infrared window (NIR-II), especially in the range of 1500-1700 nm (NIR-IIb), affords great opportunities for glioblastoma (GBM) management. Herein, an organic assembly (denoted as LET-12) with the maximum absorption peak at 1400 nm and emission peak at 1512 nm with trailing over 1700 nm through the self-assembly of organic small molecule IR-1064 is designed and subsequently decorated with choline and acetylcholine analogs. The LET-12 can effectively cross BBB through the brain's choline-like receptors-mediated transcytosis and accumulated in tumor tissues, thus achieving fluorescence/photoacoustic (FL/PA) duplex imaging of orthotopic GBM with ≈3.0 mm depth and a superior tumor-to-normal tissue signal ratio (20.93 ± 0.59 for FL imaging and 32.63 ± 1.16 for PA imaging, respectively). Owing to its good photothermal conversion ability, the LET-12 also can serve as a photothermal conversion agent, achieving obvious tumor repression of orthotopic murine GBM model after once treatment. The findings indicate that the LET-12 holds great potential for BBB-crossing NIR-IIb phototheranostics of orthotopic GBM. This self-assembly strategy of organic small molecules opens a new avenue for the construction of NIR-IIb phototheranostics.
Collapse
Affiliation(s)
- Feng Zhao
- Marshall Laboratory of Biomedical Engineering, International Cancer Center, Laboratory of Evolutionary Theranostics (LET), School of Biomedical Engineering, Shenzhen University Medical School, Shenzhen, 518060, China
| | - Xinming Zhang
- Marshall Laboratory of Biomedical Engineering, International Cancer Center, Laboratory of Evolutionary Theranostics (LET), School of Biomedical Engineering, Shenzhen University Medical School, Shenzhen, 518060, China
| | - Fang Bai
- Marshall Laboratory of Biomedical Engineering, International Cancer Center, Laboratory of Evolutionary Theranostics (LET), School of Biomedical Engineering, Shenzhen University Medical School, Shenzhen, 518060, China
| | - Shan Lei
- Marshall Laboratory of Biomedical Engineering, International Cancer Center, Laboratory of Evolutionary Theranostics (LET), School of Biomedical Engineering, Shenzhen University Medical School, Shenzhen, 518060, China
| | - Gang He
- Marshall Laboratory of Biomedical Engineering, International Cancer Center, Laboratory of Evolutionary Theranostics (LET), School of Biomedical Engineering, Shenzhen University Medical School, Shenzhen, 518060, China
| | - Peng Huang
- Marshall Laboratory of Biomedical Engineering, International Cancer Center, Laboratory of Evolutionary Theranostics (LET), School of Biomedical Engineering, Shenzhen University Medical School, Shenzhen, 518060, China
| | - Jing Lin
- Marshall Laboratory of Biomedical Engineering, International Cancer Center, Laboratory of Evolutionary Theranostics (LET), School of Biomedical Engineering, Shenzhen University Medical School, Shenzhen, 518060, China
| |
Collapse
|
4
|
Flores-Muñoz C, García-Rojas F, Pérez MA, Santander O, Mery E, Ordenes S, Illanes-González J, López-Espíndola D, González-Jamett AM, Fuenzalida M, Martínez AD, Ardiles ÁO. The Long-Term Pannexin 1 Ablation Produces Structural and Functional Modifications in Hippocampal Neurons. Cells 2022; 11:cells11223646. [PMID: 36429074 PMCID: PMC9688914 DOI: 10.3390/cells11223646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 10/29/2022] [Accepted: 11/10/2022] [Indexed: 11/19/2022] Open
Abstract
Enhanced activity and overexpression of Pannexin 1 (Panx1) channels contribute to neuronal pathologies such as epilepsy and Alzheimer's disease (AD). The Panx1 channel ablation alters the hippocampus's glutamatergic neurotransmission, synaptic plasticity, and memory flexibility. Nevertheless, Panx1-knockout (Panx1-KO) mice still retain the ability to learn, suggesting that compensatory mechanisms stabilize their neuronal activity. Here, we show that the absence of Panx1 in the adult brain promotes a series of structural and functional modifications in the Panx1-KO hippocampal synapses, preserving spontaneous activity. Compared to the wild-type (WT) condition, the adult hippocampal neurons of Panx1-KO mice exhibit enhanced excitability, a more complex dendritic branching, enhanced spine maturation, and an increased proportion of multiple synaptic contacts. These modifications seem to rely on the actin-cytoskeleton dynamics as an increase in the actin polymerization and an imbalance between the Rac1 and the RhoA GTPase activities were observed in Panx1-KO brain tissues. Our findings highlight a novel interaction between Panx1 channels, actin, and Rho GTPases, which appear to be relevant for synapse stability.
Collapse
Affiliation(s)
- Carolina Flores-Muñoz
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
- Centro de Neurología Traslacional, Facultad de Medicina, Universidad de Valparaíso, Valparaíso 2341386, Chile
- Programa de Doctorado en Ciencias, Mención Neurociencia, Universidad de Valparaíso, Valparaíso 2340000, Chile
| | - Francisca García-Rojas
- Programa de Doctorado en Ciencias, Mención Neurociencia, Universidad de Valparaíso, Valparaíso 2340000, Chile
- Centro de Neurobiología y Fisiopatología integrativa, CENFI, Instituto de Fisiología, Universidad de Valparaíso, Valparaíso 2340000, Chile
| | - Miguel A. Pérez
- Centro de Neurobiología y Fisiopatología integrativa, CENFI, Instituto de Fisiología, Universidad de Valparaíso, Valparaíso 2340000, Chile
- Escuela de Ciencias de la Salud, Universidad de Viña del Mar, Viña del Mar 2572007, Chile
| | - Odra Santander
- Programa de Doctorado en Ciencias, Mención Neurociencia, Universidad de Valparaíso, Valparaíso 2340000, Chile
- Centro de Neurobiología y Fisiopatología integrativa, CENFI, Instituto de Fisiología, Universidad de Valparaíso, Valparaíso 2340000, Chile
| | - Elena Mery
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
- Centro de Neurología Traslacional, Facultad de Medicina, Universidad de Valparaíso, Valparaíso 2341386, Chile
| | - Stefany Ordenes
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
- Centro de Neurología Traslacional, Facultad de Medicina, Universidad de Valparaíso, Valparaíso 2341386, Chile
- Programa de Doctorado en Ciencias, Mención Neurociencia, Universidad de Valparaíso, Valparaíso 2340000, Chile
| | - Javiera Illanes-González
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
- Centro de Neurología Traslacional, Facultad de Medicina, Universidad de Valparaíso, Valparaíso 2341386, Chile
- Programa de Doctorado en Ciencias, Mención Neurociencia, Universidad de Valparaíso, Valparaíso 2340000, Chile
| | - Daniela López-Espíndola
- Escuela de Tecnología Médica, Facultad de Medicina, Universidad de Valparaíso, Valparaíso 2529002, Chile
- Centro de Investigaciones Biomédicas, Escuela de Medicina, Facultad de Medicina, Universidad de Valparaíso, Viña del Mar 2529002, Chile
| | - Arlek M. González-Jamett
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
- Escuela de Química y Farmacia, Facultad de Farmacia, Universidad de Valparaíso, Valparaíso 2360102, Chile
| | - Marco Fuenzalida
- Centro de Neurobiología y Fisiopatología integrativa, CENFI, Instituto de Fisiología, Universidad de Valparaíso, Valparaíso 2340000, Chile
- Correspondence: (M.F.); (A.D.M.); (Á.O.A.)
| | - Agustín D. Martínez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
- Correspondence: (M.F.); (A.D.M.); (Á.O.A.)
| | - Álvaro O. Ardiles
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
- Centro de Neurología Traslacional, Facultad de Medicina, Universidad de Valparaíso, Valparaíso 2341386, Chile
- Centro Interdisciplinario de estudios en salud, Escuela de Medicina, Facultad de Medicina, Universidad de Valparaíso, Viña del Mar 2572007, Chile
- Correspondence: (M.F.); (A.D.M.); (Á.O.A.)
| |
Collapse
|
5
|
Shrivastava S, Sarkar P, Preira P, Salomé L, Chattopadhyay A. Cholesterol-Dependent Dynamics of the Serotonin 1A Receptor Utilizing Single Particle Tracking: Analysis of Diffusion Modes. J Phys Chem B 2022; 126:6682-6690. [PMID: 35973070 DOI: 10.1021/acs.jpcb.2c03941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
G protein-coupled receptors (GPCRs) are signaling hubs in cell membranes that regulate a wide range of physiological processes and are popular drug targets. Serotonin1A receptors are important members of the GPCR family and are implicated in neuropsychiatric disorders. Cholesterol is a key constituent of higher eukaryotic membranes and is believed to contribute to the segregated distribution of membrane constituents into domains. To explore the role of cholesterol in lateral dynamics of GPCRs, we utilized single particle tracking (SPT) to monitor diffusion of serotonin1A receptors under acute and chronic cholesterol-depleted conditions. Our results show that the short-term diffusion coefficient of the receptor decreases upon cholesterol depletion, irrespective of the method of cholesterol depletion. Analysis of SPT trajectories revealed that relative populations of receptors undergoing various modes of diffusion change upon cholesterol depletion. Notably, in cholesterol-depleted cells, we observed an increase in the confined population of the receptor accompanied by a reduction in diffusion coefficient for chronic cholesterol depletion. These results are supported by our recent work and present observations that show polymerization of G-actin in response to chronic cholesterol depletion. Taken together, our results bring out the interdependence of cholesterol and actin cytoskeleton in regulating diffusion of GPCRs in membranes.
Collapse
Affiliation(s)
- Sandeep Shrivastava
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India
| | - Parijat Sarkar
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India
| | - Pascal Preira
- Institut de Pharmacologie et de Biologie Structurale, CNRS, Université de Toulouse (UPS), 31 077 Toulouse, France
| | - Laurence Salomé
- Institut de Pharmacologie et de Biologie Structurale, CNRS, Université de Toulouse (UPS), 31 077 Toulouse, France
| | | |
Collapse
|
6
|
Wu RS, Lin YS, Nain A, Unnikrishnan B, Lin YF, Yang CR, Chen TH, Huang YF, Huang CC, Chang HT. Evaluation of chemotherapeutic response in living cells using subcellular Organelle‒Selective amphipathic carbon dots. Biosens Bioelectron 2022; 211:114362. [PMID: 35617797 DOI: 10.1016/j.bios.2022.114362] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 04/04/2022] [Accepted: 05/09/2022] [Indexed: 01/03/2023]
Abstract
Monitoring of structural changes in subcellular organelles is critical to evaluate the chemotherapeutic response of cells. However, commercial organelle selective fluorophores are easily photobleached, and thus are unsuitable for real-time and long-term observation. We have developed photostable carbon-dot liposomes (CDsomes)-based fluorophores for organellar and suborganellar imaging to circumvent these issues. The CDs synthesized through a mild pyrolysis/hydrolysis process exhibit amphipathic nature and underwent self-assembly to form liposome-like structures (CDsomes). The controlled hydrophilicity or hydrophobicity-guided preparation of CDsomes are used to selectively and rapidly (<1 min) stain nucleolus, cytoplasm, and membrane. In addition, the CDsomes offer universal high-contrast staining not only in fixed cells but also in living cells, allowing real-time observation and morphological identification in the specimen. The as-prepared CDsomes exhibit excitation-dependent fluorescence, and are much more stable under photoirradiation (e.g., ultraviolet light) than traditional subcellular dyes. Interestingly, the CDsomes can be transferred to daughter cells by diluting the particles, enabling multigenerational tracking of suborganelle for up to six generations, without interrupting the staining pattern. Therefore, we believe that the ultra-photostable CDsomes with high biocompatibility, and long-term suborganellar imaging capabilities, hold a great potential for screening and evaluating therapeutic performance of various chemotherapeutic drugs.
Collapse
Affiliation(s)
- Ren-Siang Wu
- Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan
| | - Yu-Syuan Lin
- Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan
| | - Amit Nain
- Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan
| | - Binesh Unnikrishnan
- Department of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung, 20224, Taiwan
| | - Yu-Feng Lin
- Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan
| | - Cheng-Ruei Yang
- Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan
| | - Tzu-Heng Chen
- Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan
| | - Yu-Fen Huang
- Institute of Analytical and Environmental Sciences, National Tsing Hua University, Hsinchu, 30013, Taiwan; Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, 30013, Taiwan; School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Kaohsiung, 80708, Taiwan.
| | - Chih-Ching Huang
- Department of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung, 20224, Taiwan; School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Kaohsiung, 80708, Taiwan; Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung, 20224, Taiwan
| | - Huan-Tsung Chang
- Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan.
| |
Collapse
|
7
|
Sarkar P, Kumar GA, Shrivastava S, Chattopadhyay A. Chronic cholesterol depletion increases F-actin levels and induces cytoskeletal reorganization via a dual mechanism. J Lipid Res 2022; 63:100206. [PMID: 35390404 PMCID: PMC9096963 DOI: 10.1016/j.jlr.2022.100206] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 03/22/2022] [Accepted: 03/28/2022] [Indexed: 12/24/2022] Open
Abstract
Previous work from us and others has suggested that cholesterol is an important lipid in the context of the organization of the actin cytoskeleton. However, reorganization of the actin cytoskeleton upon modulation of membrane cholesterol is rarely addressed in the literature. In this work, we explored the signaling crosstalk between cholesterol and the actin cytoskeleton by using a high-resolution confocal microscopic approach to quantitatively measure changes in F-actin content upon cholesterol depletion. Our results show that F-actin content significantly increases upon chronic cholesterol depletion, but not during acute cholesterol depletion. In addition, utilizing inhibitors targeting the cholesterol biosynthetic pathway at different steps, we show that reorganization of the actin cytoskeleton could occur due to the synergistic effect of multiple pathways, including prenylated Rho GTPases and availability of membrane phosphatidylinositol 4,5-bisphosphate. These results constitute one of the first comprehensive dissections of the mechanistic basis underlying the interplay between cellular actin levels and cholesterol biosynthesis. We envision these results will be relevant for future understating of the remodeling of the actin cytoskeleton in pathological conditions with altered cholesterol.
Collapse
Affiliation(s)
- Parijat Sarkar
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | - G Aditya Kumar
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | | | | |
Collapse
|
8
|
Taninaka A, Ugajin S, Kurokawa H, Nagoshi Y, Kamiyanagi M, Takeuchi O, Matsui H, Shigekawa H. Direct analysis of the actin-filament formation effect in photodynamic therapy. RSC Adv 2022; 12:5878-5889. [PMID: 35424553 PMCID: PMC8981521 DOI: 10.1039/d1ra09291j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 02/11/2022] [Indexed: 11/30/2022] Open
Abstract
Photodynamic therapy (PDT) is a method in which a photosensitizer is administered in vivo and irradiated with light to generate reactive oxygen species (ROS), thereby causing the selective death of cancer cells. Since PDT is a noninvasive cancer treatment method with few adverse effects, it has attracted considerable attention and is increasingly used. In PDT, there are two dominant processes based on the actin filament (A-filament) formation effect: the destruction of cells by necrosis and vascular shutdown. Despite the importance of its fine control, the mechanism of the reaction process from the generation of reactive oxygen by photoinduction inducing the formation of A-filament and its polymerization to form stress fibers (S-fibers) has not yet been clarified because, for example, it has been difficult to directly observe and quantify such processes in living cells by conventional methods. Here, we have combined atomic force microscopy (AFM) with other techniques to reveal the mechanism of the A-filament and S-fiber formation processes that underlie the cell death process due to PDT. First, it was confirmed that activation of the small G protein RhoA, which is a signal that induces an increase in A-filament production, begins immediately after PDT treatment. The production of A-filament did not increase with increasing light intensity when the amount of light was large. Namely, the activation of RhoA reached an equilibrium state in about 1 min: however, the production of A-filament and its polymerization continued. The observed process corresponds well with the change in the amount of phosphorylated myosin-light chains, which induce A-filament polymerization. The increase in the elastic modulus of cells following the formation of S-fiber was confirmed by AFM for the first time. The distribution of generated A-filament and S-fiber was consistent with the photosensitizer distribution. PDT increases A-filament production, and when the ROS concentration is high, blebbing occurs and cells die, but when it is low, cell death does not occur and S-fiber is formed. That is, it is expected that vascular shutdown can be controlled efficiently by adjusting the amount of photosensitizer and the light intensity. We have combined atomic force microscopy with other techniques to reveal the mechanism of the actin filament and stress fibers formation processes that underlies the cell death process due to photodynamic therapy.![]()
Collapse
Affiliation(s)
- Atsushi Taninaka
- Faculty of Pure and Applied Sciences, University of Tsukuba 305-8573 Ibaraki Japan .,TAKANO Co., LTD. Miyada-mura, Kamiina-gun Nagano 399-4301 Japan
| | - Shunta Ugajin
- Faculty of Pure and Applied Sciences, University of Tsukuba 305-8573 Ibaraki Japan
| | - Hiromi Kurokawa
- Faculty of Medicine, University of Tsukuba 305-8575 Ibaraki Japan
| | - Yu Nagoshi
- Faculty of Pure and Applied Sciences, University of Tsukuba 305-8573 Ibaraki Japan
| | - Mayuka Kamiyanagi
- Faculty of Pure and Applied Sciences, University of Tsukuba 305-8573 Ibaraki Japan
| | - Osamu Takeuchi
- Faculty of Pure and Applied Sciences, University of Tsukuba 305-8573 Ibaraki Japan
| | - Hirofumi Matsui
- Faculty of Medicine, University of Tsukuba 305-8575 Ibaraki Japan
| | - Hidemi Shigekawa
- Faculty of Pure and Applied Sciences, University of Tsukuba 305-8573 Ibaraki Japan
| |
Collapse
|
9
|
Tang H, Shi X, Zhu P, Guo W, Li J, Yan B, Zhang S. Melatonin inhibits gallbladder cancer cell migration and invasion via ERK-mediated induction of epithelial-to-mesenchymal transition. Oncol Lett 2021; 22:609. [PMID: 34188711 PMCID: PMC8227585 DOI: 10.3892/ol.2021.12870] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 05/19/2021] [Indexed: 12/13/2022] Open
Abstract
Melatonin is a naturally occurring molecule secreted by the pineal gland that exhibits antitumor properties and prevents the development of human cancer. However, little is known regarding the effects of melatonin on gallbladder cancer (GBC) cells. The present study aimed to investigate the role of melatonin on the prevention of GBC cell invasion. The GBC cell line, GBC-SD, was treated with different concentrations of melatonin for different time periods, and the data indicated that melatonin markedly inhibited the invasion of GBC cells. Following treatment of GBC cells with melatonin, the protein levels of the epithelial marker, E-cadherin, significantly increased, while the expression levels of the mesenchymal markers, N-cadherin, Snail and vimentin, notably decreased. In addition, melatonin inhibited the phosphorylation of ERK1/2. Following treatment of the cells with the ERK activator, tert-Butylhydroquinone, the anti-invasive effects of melatonin were reversed by rescuing epithelial-to-mesenchymal transition in GBC cells. Taken together, these results suggest that melatonin inhibits GBC invasiveness by blocking the ERK signaling pathway. Thus, melatonin may be used as a potential novel cancer therapeutic drug for the treatment of GBC.
Collapse
Affiliation(s)
- Hongwei Tang
- ZhengZhou Engineering Laboratory of Organ Transplantation Technique and Application, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China.,Henan Engineering Technology Research Center of Organ Transplantation, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China
| | - Xiaoyi Shi
- Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China
| | - Pengfei Zhu
- Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China
| | - Wenzhi Guo
- Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China
| | - Jie Li
- Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China
| | - Bing Yan
- ZhengZhou Engineering Laboratory of Organ Transplantation Technique and Application, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China.,Henan Engineering Technology Research Center of Organ Transplantation, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China
| | - Shuijun Zhang
- ZhengZhou Engineering Laboratory of Organ Transplantation Technique and Application, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China.,Henan Engineering Technology Research Center of Organ Transplantation, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China.,Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China
| |
Collapse
|
10
|
Panseri S, Montesi M, Hautcoeur D, Dozio SM, Chamary S, De Barra E, Tampieri A, Leriche A. Bone-like ceramic scaffolds designed with bioinspired porosity induce a different stem cell response. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2021; 32:3. [PMID: 33471246 PMCID: PMC7817586 DOI: 10.1007/s10856-020-06486-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 12/18/2020] [Indexed: 05/12/2023]
Abstract
Biomaterial science increasingly seeks more biomimetic scaffolds that functionally augment the native bone tissue. In this paper, a new concept of a structural scaffold design is presented where the physiological multi-scale architecture is fully incorporated in a single-scaffold solution. Hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) bioceramic scaffolds with different bioinspired porosity, mimicking the spongy and cortical bone tissue, were studied. In vitro experiments, looking at the mesenchymal stem cells behaviour, were conducted in a perfusion bioreactor that mimics the physiological conditions in terms of interstitial fluid flow and associated induced shear stress. All the biomaterials enhanced cell adhesion and cell viability. Cortical bone scaffolds, with an aligned architecture, induced an overexpression of several late stage genes involved in the process of osteogenic differentiation compared to the spongy bone scaffolds. This study reveals the exciting prospect of bioinspired porous designed ceramic scaffolds that combines both cortical and cancellous bone in a single ceramic bone graft. It is prospected that dual core shell scaffold could significantly modulate osteogenic processes, once implanted in patients, rapidly forming mature bone tissue at the tissue interface, followed by subsequent bone maturation in the inner spongy structure.
Collapse
Affiliation(s)
- Silvia Panseri
- Institute of Science and Technology for Ceramics, National Research Council, Faenza, Italy.
| | - Monica Montesi
- Institute of Science and Technology for Ceramics, National Research Council, Faenza, Italy
| | - Dominique Hautcoeur
- Belgian Ceramic Research Centre, Avenue Gouverneur Cornez 4, B-7000, Mons, Belgium
| | - Samuele M Dozio
- Institute of Science and Technology for Ceramics, National Research Council, Faenza, Italy
| | - Shaan Chamary
- Université Polytechnique Hauts-de-France, Laboratoire des Matériaux Céramiques et Procédés Associés, 59313, Valenciennes, France
| | - Eamonn De Barra
- University of Limerick, Bernal Institute, Limerick, V94 T9PX, Ireland
| | - Anna Tampieri
- Institute of Science and Technology for Ceramics, National Research Council, Faenza, Italy
| | - Anne Leriche
- Université Polytechnique Hauts-de-France, Laboratoire des Matériaux Céramiques et Procédés Associés, 59313, Valenciennes, France
| |
Collapse
|
11
|
Jiang L, Hu LG. Serpin peptidase inhibitor clade A member 1-overexpression in gastric cancer promotes tumor progression in vitro and is associated with poor prognosis. Oncol Lett 2020; 20:278. [PMID: 33014156 PMCID: PMC7520747 DOI: 10.3892/ol.2020.12141] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 07/01/2020] [Indexed: 12/14/2022] Open
Abstract
Gastric cancer is the second most common cause of cancer-associated death in Asia. The incidence and mortality rates of gastric cancer have markedly increased in the past few decades. Therefore, the identification of novel gastric cancer biomarkers are needed to determine prognosis. The role of serpin peptidase inhibitor clade A member 1 (SERPINA1) has been studied in several types of cancer; however, little is known about its mechanism in gastric cancer. The present study aimed to evaluate SERPINA1 as a potential prognostic biomarker in gastric cancer and to identify the possible mechanisms underlying its action. The expression levels of SERPINA1 in several gastric cancer datasets were assessed, and it was identified that high expression of SERPINA1 was associated to poor clinical outcomes. Furthermore, using histochemical analysis, western blotting, apoptotic analysis, gap closure and invasion assays in cell lines, it was reported that silencing of SERPINA1 inhibited the formation of cellular pseudopodia and did not affect apoptosis, but promoted cell cycle S-phase entry. In addition, overexpression of SERPINA1 increased the migration and invasion of gastric cancer cells, whereas knockdown of SERPINA1 decreased these functions. Moreover, SERPINA1 overexpression increased the protein levels of SMAD4, which is a key regulator of the transforming growth factor (TGF)-β signaling pathway. Taken together, the present data demonstrated that SERPINA1 promotes gastric cancer progression through TGF-β signaling, and suggested that SERPINA1 may be a novel prognostic biomarker from tumor tissue biopsy in gastric cancer.
Collapse
Affiliation(s)
- Longchang Jiang
- Translational Safety and Bioanalytical Sciences, Amgen Research, Amgen Asia Research and Development Center, Shanghai 201210, P.R. China
| | - Liangbiao George Hu
- Translational Safety and Bioanalytical Sciences, Amgen Research, Amgen Asia Research and Development Center, Shanghai 201210, P.R. China
| |
Collapse
|
12
|
Yu JG, Isaksson A, Rova A, Tegner Y, Eriksson A, Malm C. Potential effects of long-term abuse of anabolic androgen steroids on human skeletal muscle. J Sports Med Phys Fitness 2020; 60:1040-1048. [DOI: 10.23736/s0022-4707.20.10443-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
13
|
Tampieri A, Ruffini A, Ballardini A, Montesi M, Panseri S, Salamanna F, Fini M, Sprio S. Heterogeneous chemistry in the 3-D state: an original approach to generate bioactive, mechanically-competent bone scaffolds. Biomater Sci 2019; 7:307-321. [PMID: 30468436 DOI: 10.1039/c8bm01145a] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The present work investigates heterogeneous gas-solid reactions involved in the biomorphic transformation of natural wood into large 3-D hydroxyapatite (HA) scaffolds recapitulating physico-chemical, morphological and mechanical features typical of natural bone. In particular, we found that the use of a reactive CO2/H2O gas mixture, under supercritical conditions at high pressure, permits to control heterogeneous CaO-CO2 reactions throughout the whole bulk and to direct the nucleation-growth of CaCO3 at a relatively low temperature, thus obtaining a highly reactive 3-D precursor enabling the formation of a large biomorphic HA scaffold preserving fine nanostructure by a hydrothermal process. To the best of our knowledge, the application of heterogeneous chemical reactions in the 3-D state is an original way to generate large HA scaffolds maintaining bio-relevant ionic substitutions, with specific regard to Mg2+, Sr2+ and CO32- ions, conferring a superior ability to guide cell fate. We hypothesize that the original nanostructure of the final 3-D HA scaffold, not achievable by the classic sintering procedure, and the multi-scale hierarchical organization inherited by the original template, account for its high compression strength with damage-tolerant mechanical behaviour. The ability of the new scaffold to induce bone regeneration is attested by the overexpression of genes, early and late markers of the osteogenic differentiation pathway, and by the in vivo osteoinductivity. We hypothesize that the unique association of bioactive chemical composition, nanostructure and multi-scale hierarchy can synergistically act as instructing signals for cells to generate new bone tissue with organized 3-D architecture. These results point to its great applicative potential for the regeneration of large bone defects, which is a still unmet clinical need.
Collapse
Affiliation(s)
- Anna Tampieri
- Institute of Science and Technology for Ceramics, National Research Council, Via Granarolo 64, 48018 Faenza, Italy.
| | | | | | | | | | | | | | | |
Collapse
|
14
|
Fabbri A, Travaglione S, Maroccia Z, Guidotti M, Pierri CL, Primiano G, Servidei S, Loizzo S, Fiorentini C. The Bacterial Protein CNF1 as a Potential Therapeutic Strategy against Mitochondrial Diseases: A Pilot Study. Int J Mol Sci 2018; 19:E1825. [PMID: 29933571 PMCID: PMC6073533 DOI: 10.3390/ijms19071825] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 06/18/2018] [Indexed: 02/07/2023] Open
Abstract
The Escherichia coli protein toxin cytotoxic necrotizing factor 1 (CNF1), which acts on the Rho GTPases that are key regulators of the actin cytoskeleton, is emerging as a potential therapeutic tool against certain neurological diseases characterized by cellular energy homeostasis impairment. In this brief communication, we show explorative results on the toxin’s effect on fibroblasts derived from a patient affected by myoclonic epilepsy with ragged-red fibers (MERRF) that carries a mutation in the m.8344A>G gene of mitochondrial DNA. We found that, in the patient’s cells, besides rescuing the wild-type-like mitochondrial morphology, CNF1 administration is able to trigger a significant increase in cellular content of ATP and of the mitochondrial outer membrane marker Tom20. These results were accompanied by a profound F-actin reorganization in MERRF fibroblasts, which is a typical CNF1-induced effect on cell cytoskeleton. These results point at a possible role of the actin organization in preventing or limiting the cell damage due to mitochondrial impairment and at CNF1 treatment as a possible novel strategy against mitochondrial diseases still without cure.
Collapse
Affiliation(s)
- Alessia Fabbri
- Italian Center for Global Health, Istituto Superiore di Sanità, Viale Regina Elena, 299, 00161 Rome, Italy.
| | - Sara Travaglione
- Italian Center for Global Health, Istituto Superiore di Sanità, Viale Regina Elena, 299, 00161 Rome, Italy.
| | - Zaira Maroccia
- Italian Center for Global Health, Istituto Superiore di Sanità, Viale Regina Elena, 299, 00161 Rome, Italy.
| | - Marco Guidotti
- Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità, Viale Regina Elena, 299, 00161 Rome, Italy.
| | - Ciro Leonardo Pierri
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, via Orabona, 4, 70124 Bari, Italy.
| | - Guido Primiano
- Unità di Neurofisiopatologia, Area Neuroscienze, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Largo Agostino Gemelli, 8, 00168 Rome, Italy.
| | - Serenella Servidei
- Unità di Neurofisiopatologia, Area Neuroscienze, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Largo Agostino Gemelli, 8, 00168 Rome, Italy.
| | - Stefano Loizzo
- Italian Center for Global Health, Istituto Superiore di Sanità, Viale Regina Elena, 299, 00161 Rome, Italy.
| | - Carla Fiorentini
- Italian Center for Global Health, Istituto Superiore di Sanità, Viale Regina Elena, 299, 00161 Rome, Italy.
| |
Collapse
|
15
|
Combined VEGF/PDGF inhibition using axitinib induces αSMA expression and a pro-fibrotic phenotype in human pericytes. Graefes Arch Clin Exp Ophthalmol 2018; 256:1141-1149. [PMID: 29721663 DOI: 10.1007/s00417-018-3987-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 03/06/2018] [Accepted: 04/11/2018] [Indexed: 01/08/2023] Open
Abstract
PURPOSE Large trials on anti-VEGF/PDGF (vascular endothelial/platelet-derived growth factor) combination therapy have been established to improve management of neovascular activity in age-related macular degeneration. Targeting pericytes, PDGF is thought to induce vessel regression and reduce fibrovascular scarring. The fate of pericytes exposed to anti-VEGF/PDGF combination therapy is not clear. Therefore, this study was designed to study the influence of anti-VEGF/PDGF on pericyte phenotype and cellular behavior. METHODS Human pericytes from placenta (hPC-PL) were treated with axitinib, a tyrosine kinase inhibitor targeting VEGFR1-3 and PDGFR. Toxic effects were excluded using live/dead staining. Phenotypic changes were evaluated using phalloidin staining for actin cytoskeleton and the expression of stress fibers. MRNA and protein expression levels of α-smooth muscle actin (αSMA) as a marker of proto-myofibroblastic transition were evaluated with real-time PCR and Western blotting. Influences of fibrotic cellular mechanisms were evaluated with a scratch wound migration and a collagen gel contraction assay. RESULTS Treatment with 0.5, 1, and 2.5 μg/ml axitinib strongly induced a proto-myofibroblast-like actin cytoskeleton with a marked increase in stress fibers. Quantitative real-time PCR and Western blotting revealed these changes to be linked to dose-dependent increases in αSMA mRNA and protein expression. However, fibrotic cellular mechanisms were significantly reduced in the presence of axitinib (scratch wound closure: up to - 78.4%, collagen gel contraction: up to - 37.4%). CONCLUSIONS Combined anti-VEGF/PDGF inhibition seems to induce a proto-myofibroblast-like phenotype in human pericytes in vitro, but reduce profibrotic cellular mechanisms due to prolonged anti-PDGF inhibition.
Collapse
|
16
|
Tee JY, Sutharsan R, Fan Y, Mackay-Sim A. Cell migration in schizophrenia: Patient-derived cells do not regulate motility in response to extracellular matrix. Mol Cell Neurosci 2017; 80:111-122. [PMID: 28286248 DOI: 10.1016/j.mcn.2017.03.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 01/30/2017] [Accepted: 03/06/2017] [Indexed: 01/22/2023] Open
Abstract
Schizophrenia is a highly heritable psychiatric disorder linked to a large number of risk genes. The function of these genes in disease etiology is not fully understood but pathway analyses of genomic data suggest developmental dysregulation of cellular processes such as neuronal migration and axon guidance. Previous studies of patient-derived olfactory cells show them to be more motile than control-derived cells when grown on a fibronectin substrate, motility that is dependent on focal adhesion kinase signaling. The aim of this study was to investigate whether schizophrenia patient-derived cells are responsive to other extracellular matrix (ECM) proteins that bind integrin receptors. Olfactory neurosphere-derived cells from nine patients and nine matched controls were grown on ECM protein substrates at increasing concentrations and their movement was tracked for 24h using automated high-throughput imaging. Control-derived cells increased their motility as the ECM substrate concentration increased, whereas patient-derived cell motility was little affected by ECM proteins. Patient and control cells had appropriate integrin receptors for these ECM substrates and detected them as shown by increases in focal adhesion number and size in response to ECM proteins, which also induced changes in cell morphology and cytoskeleton. These observations indicate that patient cells failed to translate the detection of ECM proteins into appropriate changes in cell motility. In a sense, patient cells act like a moving car whose accelerator is jammed, moving at the same speed without regard to the external environment. This focuses attention on cell motility regulation rather than speed as key to impairment of neuronal migration in the developing brain in schizophrenia.
Collapse
Affiliation(s)
- Jing Yang Tee
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, Queensland, Australia
| | - Ratneswary Sutharsan
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, Queensland, Australia
| | - Yongjun Fan
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, Queensland, Australia
| | - Alan Mackay-Sim
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, Queensland, Australia.
| |
Collapse
|
17
|
Campodoni E, Adamiano A, Dozio SM, Panseri S, Montesi M, Sprio S, Tampieri A, Sandri M. Development of innovative hybrid and intrinsically magnetic nanobeads as a drug delivery system. Nanomedicine (Lond) 2016; 11:2119-30. [DOI: 10.2217/nnm-2016-0101] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Aim: Synthesis of superparamagnetic hybrid nanobeads (MHNs) made of iron-substituted hydroxyapatite nanophase mineralizing a self-assembling alginate (Alg) matrix to be used as drug carriers, with ability of remote activation by magnetic signaling. Materials & methods: Iron-doped apatite was heterogeneously nucleated on the self-assembling Alg matrix by a bioinspired mineralization process and MHNs are formed by a subsequent emulsification by oil-in-water technique. Results: The obtained MHNs exhibited biomimetic composition, adequate swelling properties in physiological-like environment and superparamagnetic properties. The assembling of Alg induced the egg-like rearrangement of the mineralized composite that was then stabilized through cross-linking reaction with calcium ions. Conclusion: The new MHNs can be considered as a promising biocompatible and bio-resorbable drug delivery system with magnetic properties, thus opening to smart applications in nanomedicine.
Collapse
Affiliation(s)
- Elisabetta Campodoni
- Institute of Science & Technology for Ceramics, National Research Council of Italy, ISTEC-CNR, Faenza, Italy
| | - Alessio Adamiano
- Institute of Science & Technology for Ceramics, National Research Council of Italy, ISTEC-CNR, Faenza, Italy
| | - Samuele M Dozio
- Institute of Science & Technology for Ceramics, National Research Council of Italy, ISTEC-CNR, Faenza, Italy
- University “Gabriele D'Annunzio” of Chieti-Pescara, Chieti, Italy
| | - Silvia Panseri
- Institute of Science & Technology for Ceramics, National Research Council of Italy, ISTEC-CNR, Faenza, Italy
| | - Monica Montesi
- Institute of Science & Technology for Ceramics, National Research Council of Italy, ISTEC-CNR, Faenza, Italy
| | - Simone Sprio
- Institute of Science & Technology for Ceramics, National Research Council of Italy, ISTEC-CNR, Faenza, Italy
| | - Anna Tampieri
- Institute of Science & Technology for Ceramics, National Research Council of Italy, ISTEC-CNR, Faenza, Italy
| | - Monica Sandri
- Institute of Science & Technology for Ceramics, National Research Council of Italy, ISTEC-CNR, Faenza, Italy
| |
Collapse
|
18
|
Bianchi M, Gambardella A, Berni M, Panseri S, Montesi M, Lopomo N, Tampieri A, Marcacci M, Russo A. Surface morphology, tribological properties and in vitro biocompatibility of nanostructured zirconia thin films. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2016; 27:96. [PMID: 27003838 DOI: 10.1007/s10856-016-5707-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 03/14/2016] [Indexed: 06/05/2023]
Abstract
Deposition of nanostructured and low-wear zirconia (ZrO2) thin films on the metallic component of a total joint implant is envisaged to reduce wear of the soft ultra-high molecular weight polyethylene (UHMWPE) counterpart. In this work, morphological surface features, wear resistance and in vitro-biocompatibility of zirconia thin films deposited by the novel Pulsed Plasma Deposition (PPD) method have been investigated. Film thickness, roughness and wettability were found to be strongly dependent on deposition gas pressure. Interestingly, wear rate of UHMWPE disks coupled to zirconia-coated titanium spheres was only poorly correlated to the contact angle values, while film roughness and thickness seemed not to affect it. Furthermore, wear of UHMWPE, when coupled with zirconia coated-titanium spheres, significantly decreased with respect to uncoated spheres under dry or NaCl-lubricated conditions; besides, when using bovine serum, similar results were obtained for coated and uncoated spheres. Finally, suitable mesenchymal stem and osteoblast cells adhesion, proliferation and viability were observed, suggesting good biocompatibility of the nanostructured zirconia films. Taken together, the results shown in this work indicate that zirconia thin films deposited by the PPD method deserve further investigations as low-wear materials for biomedical applications such as total joint replacement.
Collapse
Affiliation(s)
- M Bianchi
- Istituto Ortopedico Rizzoli, Laboratorio di NanoBiotecnologie (NaBi), via di Barbiano 1/10, 40136, Bologna, Italy.
| | - A Gambardella
- Istituto Ortopedico Rizzoli, Laboratorio di NanoBiotecnologie (NaBi), via di Barbiano 1/10, 40136, Bologna, Italy
| | - M Berni
- Istituto Ortopedico Rizzoli, Laboratorio di NanoBiotecnologie (NaBi), via di Barbiano 1/10, 40136, Bologna, Italy
| | - S Panseri
- Institute of Science and Technology for Ceramics, National Research Council of Italy, via Granarolo 64, 48018, Faenza, Italy
| | - M Montesi
- Institute of Science and Technology for Ceramics, National Research Council of Italy, via Granarolo 64, 48018, Faenza, Italy
| | - N Lopomo
- Dipartimento di Ingegneria dell'Informazione, Università degli Studi di Brescia, via Branze 38, Brescia, Italy
| | - A Tampieri
- Institute of Science and Technology for Ceramics, National Research Council of Italy, via Granarolo 64, 48018, Faenza, Italy
| | - M Marcacci
- Istituto Ortopedico Rizzoli, Laboratorio di Biomeccanica e Innovazione Tecnologica, via di Barbiano 1/10, 40136, Bologna, Italy
- Dipartimento di Scienze Biomediche e Neuromotorie-DIBINEM, Università di Bologna, via Zamboni 33, 40126, Bologna, Italy
| | - A Russo
- Istituto Ortopedico Rizzoli, Laboratorio di NanoBiotecnologie (NaBi), via di Barbiano 1/10, 40136, Bologna, Italy
| |
Collapse
|
19
|
Boanini E, Panseri S, Arroyo F, Montesi M, Rubini K, Tampieri A, Covarrubias C, Bigi A. Alendronate Functionalized Mesoporous Bioactive Glass Nanospheres. MATERIALS 2016; 9:ma9030135. [PMID: 28773259 PMCID: PMC5456651 DOI: 10.3390/ma9030135] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 02/11/2016] [Accepted: 02/18/2016] [Indexed: 11/16/2022]
Abstract
In this work we synthesized mesoporous bioactive glass nanospheres (nMBG) with the aim to utilize them as substrates for loading one of the most potent amino-bisphosphonates, alendronate (AL). The results of the chemical and structural characterization show that the nMBG display a relatively high surface area (528 m²/g) and a mean pore volume of 0.63 cm³/g, both of which decrease on increasing alendronate content. It is possible to modulate the amount of AL loaded into the nanospheres up to a maximum value of about 17 wt %. In vitro tests were performed using a human osteosarcoma cell line (MG63) and a murine monocyte/macrophage cell line as osteoclast model (RAW 264.7). The results indicate that even the lower concentration of alendronate provokes decreased tumor cell viability, and that osteoclast activity exhibits an alendronate dose-dependent inhibition. The data suggest that nMBG can act as a suitable support for the local delivery of alendronate, and that the antiresorptive and antitumor properties of the functionalized mesoporous nanospheres can be modulated by varying the amount of alendronate loading.
Collapse
Affiliation(s)
- Elisa Boanini
- Department of Chemistry "G. Ciamician", University of Bologna, Via Selmi 2, Bologna 40126, Italy.
| | - Silvia Panseri
- Institute of Science and Technology for Ceramics, National Research Council of Italy, Via Granarolo 64, Faenza 48018, Italy.
| | - Fabiola Arroyo
- Laboratory of Nanobiomaterials, Institute for Research in Dental Sciences, Faculty of Dentistry, University of Chile, Santiago 8380492, Chile.
| | - Monica Montesi
- Institute of Science and Technology for Ceramics, National Research Council of Italy, Via Granarolo 64, Faenza 48018, Italy.
| | - Katia Rubini
- Department of Chemistry "G. Ciamician", University of Bologna, Via Selmi 2, Bologna 40126, Italy.
| | - Anna Tampieri
- Institute of Science and Technology for Ceramics, National Research Council of Italy, Via Granarolo 64, Faenza 48018, Italy.
| | - Cristian Covarrubias
- Laboratory of Nanobiomaterials, Institute for Research in Dental Sciences, Faculty of Dentistry, University of Chile, Santiago 8380492, Chile.
| | - Adriana Bigi
- Department of Chemistry "G. Ciamician", University of Bologna, Via Selmi 2, Bologna 40126, Italy.
| |
Collapse
|
20
|
Ndishabandi D, Duquette C, Billah GEM, Reyes M, Duquette M, Lawler J, Kazerounian S. Thrombospondin-1 Modulates Actin Filament Remodeling and Cell Motility in Mouse Mammary Tumor cells in Vitro. ACTA ACUST UNITED AC 2014; 2. [PMID: 26273699 PMCID: PMC4532438 DOI: 10.15190/d.2014.23] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
It is well established that the secretion of thrombospondin-1 (TSP-1) by activated stromal cells and its accumulation in the tumor microenvironment during dysplasia inhibits primary tumor growth through inhibition of angiogenesis. This inhibitory function of TSP-1 is actuated either by inhibiting MMP9 activation and the release of VEGF from extracellular matrix or by an interaction with CD36 on the surface of endothelial cells resulting in an increase in apoptosis. In contrast, several published articles have also shown that as tumor cells become more invasive and enter the early stage of carcinoma, they up-regulate TSP-1 expression, which may promote invasion and migration. In our in vivo studies using the polyoma middle T antigen (PyT) transgenic mouse model of breast cancer, we observed that the absence of TSP-1 significantly increased the growth of primary tumors, but delayed metastasis to the lungs. In this study, we propose a mechanism for the promigratory function of TSP-1 in mouse mammary tumor cells in vitro. We demonstrate the correlations between expression of TSP-1 and its receptor integrin α3β1, which is considered a promigratory protein in cancer cells. In addition we propose that binding of TSP-1 to integrin α3β1 is important for mediating actin filament polymerization and therefore, cell motility. These findings can help explain the dual functionality of TSP-1 in cancer progression.
Collapse
Affiliation(s)
- Dorothy Ndishabandi
- Department of Pathology, Division of Experimental Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA
| | - Cameron Duquette
- Department of Pathology, Division of Experimental Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA
| | - Ghita El-Moatassim Billah
- Department of Pathology, Division of Experimental Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA
| | - Millys Reyes
- Department of Pathology, Division of Experimental Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA
| | - Mark Duquette
- Department of Pathology, Division of Experimental Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA
| | - Jack Lawler
- Department of Pathology, Division of Experimental Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA
| | - Shideh Kazerounian
- Department Pediatrics, Division of Genetics, Boston Children's Hospital and Harvard Medical School Boston, MA
| |
Collapse
|
21
|
Bassani P, Panseri S, Ruffini A, Montesi M, Ghetti M, Zanotti C, Tampieri A, Tuissi A. Porous NiTi shape memory alloys produced by SHS: microstructure and biocompatibility in comparison with Ti2Ni and TiNi3. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2014; 25:2277-2285. [PMID: 24928669 DOI: 10.1007/s10856-014-5253-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 06/03/2014] [Indexed: 06/03/2023]
Abstract
Shape memory alloys based on NiTi have found their main applications in manufacturing of new biomedical devices mainly in surgery tools, stents and orthopedics. Porous NiTi can exhibit an engineering elastic modulus comparable to that of cortical bone (12-17 GPa). This condition, combined with proper pore size, allows good osteointegration. Open cells porous NiTi was produced by self propagating high temperature synthesis (SHS), starting from Ni and Ti mixed powders. The main NiTi phase is formed during SHS together with other Ni-Ti compounds. The biocompatibility of such material was investigated by single culture experiment and ionic release on small specimen. In particular, NiTi and porous NiTi were evaluated together with elemental Ti and Ni reference metals and the two intermetallic TiNi3, Ti2Ni phases. This approach permitted to clearly identify the influence of secondary phases in porous NiTi materials and relation with Ni-ion release. The results indicated, apart the well-known high toxicity of Ni, also toxicity of TiNi3, whilst phases with higher Ti content showed high biocompatibility. A slightly reduced biocompatibility of porous NiTi was ascribed to combined effect of TiNi3 presence and topography that requires higher effort for the cells to adapt to the surface.
Collapse
Affiliation(s)
- Paola Bassani
- Unit of Lecco, Institute for Energetics and Interphases, National Research Council of Italy - IENI-CNR, Corso Promessi Sposi 29, 23900, Lecco, Italy,
| | | | | | | | | | | | | | | |
Collapse
|
22
|
Wertheimer C, Liegl R, Kernt M, Docheva D, Kampik A, Eibl-Lindner KH. EGFR-blockade with erlotinib reduces EGF and TGF-β2 expression and the actin-cytoskeleton which influences different aspects of cellular migration in lens epithelial cells. Curr Eye Res 2014; 39:1000-12. [PMID: 24588338 DOI: 10.3109/02713683.2014.888453] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
INTRODUCTION After cataract surgery, residual lens epithelial cells migrate and proliferate within the capsular bag resulting in posterior capsule opacification (PCO). The up-regulation of TGF-β2, EGF and FGF-2 has been identified as a key factor in PCO pathogenesis leading to actin fiber assembly and alterations in the migration pattern. In this in vitro study, the influence of Erlotinib as a selective EGFR inhibitor is investigated on the cellular features indicated, which might promote a future clinical application. METHODS Expression of EGF, FGF-2 and TGF-β2 was measured using RT-PCR and ELISA in human lens epithelial cells (HLEC). Computational data of an in vitro time lapse microscopy assay were used for statistical analysis of single cell migration with a particular focus on cell-cell interaction; cell velocity distribution; and displacement before, during and after mitosis. The effect of Erlotinib on the actin-cytoskeleton was evaluated using Alexa Fluor 488 Phalloidin and epifluorescence microscopy. RESULTS EGF and TGF-β2 mRNA expression and protein levels are reduced by Erlotinib, while FGF-2 expression remained stable. Overall fluidity of cell-cell interaction is less in the presence of Erlotinib compared to the control and the velocity distribution across all cells becomes less uniform within the cell cluster. After mitosis, HLEC move significantly faster without EGFR inhibition, which can be completely blocked by Erlotinib. Furthermore, Erlotinib diminishes the amount of actin stress fibers and the stress fiber diameter. CONCLUSION As a novel effect of Erlotinib on HLEC, we describe the down-regulation of EGF and TGF-β2 expression, both are crucial factors for PCO development. Cellular movement displays complex alterations under EGFR inhibition, which is partly explained by actin fiber depletion. These findings further underline the role of Erlotinib in pharmacologic PCO prophylaxis.
Collapse
Affiliation(s)
- C Wertheimer
- Cell- and Molecular Biology Laboratory, Department of Ophthalmology, Ludwig-Maximilians-University , Munich , Germany and
| | | | | | | | | | | |
Collapse
|
23
|
Allard-Chamard H, Haroun S, de Brum-Fernandes AJ. Secreted phospholipase A2 type II is present in Paget's disease of bone and modulates osteoclastogenesis, apoptosis and bone resorption of human osteoclasts independently of its catalytic activity in vitro. Prostaglandins Leukot Essent Fatty Acids 2014; 90:39-45. [PMID: 24411720 DOI: 10.1016/j.plefa.2013.12.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Revised: 12/16/2013] [Accepted: 12/17/2013] [Indexed: 10/25/2022]
Abstract
OBJECTIVES To study the role of secreted phospholipase A2 (sPLA2) in the pathophysiology of human osteoclasts (OCs). METHODS Immunohistochemistry and sPLA2 inhibitors were to determine the localization of sPLA2 and its role in OCs biology. RESULTS sPLA2 is expressed by OCs from healthy fetal bone and OCs from Paget's disease but not in normal bone. Inhibition of sPLA2 greatly reduces in vitro osteoclastogenesis. DISCUSSION The decrease in OCs formed could be attributed to a decline in the viability of CD14(+) OC precursors as well as a reduced viability of mature OCs. Inhibition of sPLA2 strongly decreases bone resorption by OCs independently of actin cytoskeleton remodeling, probably also by reducing OCs viability. CONCLUSION High amounts of this enzyme are present in fetal and Pagetic bone samples. Inhibition of sPLA2in vitro decreases osteoclastogenesis and OC activity and might constitute an interesting pharmacologic target for diseases with high bone turnover.
Collapse
Affiliation(s)
- Hugues Allard-Chamard
- Division of Rheumatology, Faculté de médecine et des sciences de la santé, Centre de Recherche Clinique Étienne-Le Bel, Université de Sherbrooke, 3001-12e Avenue Nord, Sherbrooke, Québec, Canada J1H 5N4
| | - Sonia Haroun
- Division of Rheumatology, Faculté de médecine et des sciences de la santé, Centre de Recherche Clinique Étienne-Le Bel, Université de Sherbrooke, 3001-12e Avenue Nord, Sherbrooke, Québec, Canada J1H 5N4
| | - Artur J de Brum-Fernandes
- Division of Rheumatology, Faculté de médecine et des sciences de la santé, Centre de Recherche Clinique Étienne-Le Bel, Université de Sherbrooke, 3001-12e Avenue Nord, Sherbrooke, Québec, Canada J1H 5N4.
| |
Collapse
|
24
|
Adamo A, Arione A, Sharei A, Jensen KF. Flow-through comb electroporation device for delivery of macromolecules. Anal Chem 2013; 85:1637-41. [PMID: 23259401 DOI: 10.1021/ac302887a] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We present a microfluidic electroporation device with a comb electrode layout fabricated in polydimethylsiloxane (PMDS) and glass. Characterization experiments with HeLa cells and fluorescent dextran show efficient delivery (∼95%) with low toxicity (cell viability ∼85%) as well as rapid pore closure after electroporation. The activity of delivered molecules is also verified by silencing RNA (siRNA) studies that demonstrate gene knockdown in GFP expressing cells. This simple, scalable approach to microfluidic, flow-through electroporation could facilitate the integration of electroporation modules within cell analysis devices that perform multiple operations.
Collapse
Affiliation(s)
- Andrea Adamo
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue Cambridge, Massachusetts 02139, United States
| | | | | | | |
Collapse
|
25
|
Improved penile histology by phalloidin stain: circular and longitudinal cavernous smooth muscles, dual-endothelium arteries, and erectile dysfunction-associated changes. Urology 2011; 78:970.e1-8. [PMID: 21840580 DOI: 10.1016/j.urology.2011.06.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Revised: 05/17/2011] [Accepted: 06/06/2011] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To investigate whether fluorochrome-conjugated phalloidin can delineate cavernous smooth muscle (CSM) cells and whether it can be combined with immunofluorescence (IF) staining to quantify erectile dysfunction (ED)-associated changes. METHODS ED was induced by cavernous nerve crush in rats. Penile tissues of control and ED rats were stained with Alexa-488-conjugated phalloidin and/or with antibodies against rat endothelial cell antigen (RECA), CD31, neuronal nitric oxide synthase (nNOS), and collagen-IV (Col-IV). RESULTS Phalloidin was able to delineate CSM as composed of a circular and a longitudinal compartment. When combined with IF stain for CD31 or RECA, it helped the identification of the helicine arteries as covered by endothelial cells on both sides of the smooth muscle layer. When combined with IF stain for nNOS, it helped the identification that nNOS-positive nerves were primarily localized within the dorsal nerves and in the adventitia of dorsal arteries. When combined with IF stain for Col-IV, it helped identify that Col-IV was localized around smooth muscles and beneath the endothelium. Phalloidin also facilitated the quantitative analysis of ED-related changes in the penis. In rats with cavernous nerve injury, RECA or Col-IV expression did not change significantly, but CSM and nNOS nerve contents decreased significantly. CONCLUSION Phalloidin stain improved penile histology, enabling the visualization of the circular and longitudinal compartments in the CSM. It also worked synergistically with IF stain, permitting the visualization of the dual endothelial covering in helicine arteries, and facilitating the quantification of ED-related histologic changes.
Collapse
|
26
|
Nieuwoudt M, Wiggett S, Malfeld S, van der Merwe SW. Imaging glucose metabolism in perfluorocarbon-perfused hepatocyte bioreactors using positron emission tomography. J Artif Organs 2009; 12:247-57. [PMID: 20035398 DOI: 10.1007/s10047-009-0480-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2009] [Accepted: 10/19/2009] [Indexed: 10/20/2022]
Abstract
In vitro hepatocyte bioreactor functionality depends particularly on maintaining appropriate oxygen levels and exposure to nonparenchymal cells. An attractive solution without immunological consequences to the patient is incorporating a perfluorocarbon oxygen carrier in the circulating medium and co-culturing hepatocytes with stellate cells. Since bioreactors are normally sealed sterile units, demonstrating metabolic functionality is hindered by limited access to the cells after their aggregation in the matrix. A novel possibility is to use positron emission tomography (PET) to image cellular radioactive glucose uptake under O(2)-limited conditions. In this study, primary cell isolation procedures were carried out on eight pigs. Pairs of cell-seeded and cell-free (control) bioreactors with and without perfluorocarbon were cultured under identical conditions and were oxygenated using hypoxic (5% O(2)) and ambient (20% O(2)) gas mixes. Sixteen PET scans were conducted 24 h after cell isolation, the same timescale as that involved in treating a liver failure patient with a primary-cell bioreactor. In all cases, cell-seeded bioreactors without perfluorocarbon were more radioactive, i.e., were more glycolytic, than those with perfluorocarbon. This difference was significant in the hypoxic pair of bioreactors but not in the ambient pair of bioreactors. Additionally, in the same hypoxic bioreactors, circulating extracellular steady-state glucose levels were significantly lower and lactate levels were higher than those in the ambient bioreactors. Similar findings have been made in other in vitro hepatocyte studies investigating the effects of perfluorocarbons. PET is attractive for studying in situ O(2)-dependent bioreactor metabolism because of its visual and numerically quantifiable outputs. Longer-term metabolic studies (e.g., 5-10 days) investigating the effect of perfluorocarbon on bioreactor longevity will complement these findings in the future.
Collapse
Affiliation(s)
- Martin Nieuwoudt
- Bioengineering Unit, Hepatology Research Laboratory, University of Pretoria, Prinshof Campus, Dr Savage road, Pretoria, South Africa.
| | | | | | | |
Collapse
|
27
|
Akundi RS, Rivkees SA. Hypoxia alters cell cycle regulatory protein expression and induces premature maturation of oligodendrocyte precursor cells. PLoS One 2009; 4:e4739. [PMID: 19270736 PMCID: PMC2649433 DOI: 10.1371/journal.pone.0004739] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2008] [Accepted: 02/08/2009] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Periventricular white matter injury (PWMI) is a common form of brain injury sustained by preterm infants. A major factor that predisposes to PWMI is hypoxia. Because oligodendrocytes (OLs) are responsible for myelination of axons, abnormal OL development or function may affect brain myelination. At present our understanding of the influences of hypoxia on OL development is limited. To examine isolated effects of hypoxia on OLs, we examined the influences of hypoxia on OL development in vitro. METHODOLOGY/FINDINGS Cultures of oligodendrocyte precursor cells (OPCs) were prepared from mixed glial cultures and were 99% pure. OPCs were maintained at 21% O(2) or hypoxia (1% or 4% O(2)) for up to 7 days. We observed that 1% O(2) lead to an increase in the proportion of myelin basic protein (MBP)-positive OLs after 1 week in culture, and a decrease in the proportion of platelet-derived growth factor receptor alpha (PDGFRalpha)-positive cells suggesting premature OL maturation. Increased expression of the cell cycle regulatory proteins p27(Kip1) and phospho-cdc2, which play a role in OL differentiation, was seen as well. CONCLUSIONS These results show that hypoxia interferes with the normal process of OL differentiation by inducing premature OPC maturation.
Collapse
Affiliation(s)
- Ravi Shankar Akundi
- Yale Child Health Research Center, Section of Developmental Biology & Endocrinology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Scott A. Rivkees
- Yale Child Health Research Center, Section of Developmental Biology & Endocrinology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| |
Collapse
|
28
|
Liu JX, Höglund AS, Karlsson P, Lindblad J, Qaisar R, Aare S, Bengtsson E, Larsson L. Myonuclear domain size and myosin isoform expression in muscle fibres from mammals representing a 100 000-fold difference in body size. Exp Physiol 2008; 94:117-29. [DOI: 10.1113/expphysiol.2008.043877] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
29
|
Jackaman C, Nowak KJ, Ravenscroft G, Lim EM, Clément S, Laing NG. Novel application of flow cytometry: determination of muscle fiber types and protein levels in whole murine skeletal muscles and heart. ACTA ACUST UNITED AC 2008; 64:914-25. [PMID: 17922482 DOI: 10.1002/cm.20239] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Conventional methods for measuring proteins within muscle samples such as immunohistochemistry and western blot analysis can be time consuming, labor intensive and subject to sampling errors. We have developed flow cytometry techniques to detect proteins in whole murine heart and skeletal muscle. Flow cytometry and immunohistochemistry were performed on quadriceps and soleus muscles from male C57BL/6J, BALB/c, CBA and mdx mice. Proteins including actins, myosins, tropomyosin and alpha-actinin were detected via single staining flow cytometric analysis. This correlated with immunohistochemistry using the same antibodies. Muscle fiber types could be determined by dual labeled flow cytometry for skeletal muscle actin and different myosins. This showed similar results to immunohistochemistry for I, IIA and IIB myosins. Flow cytometry of heart samples from C57BL/6J and BALB/c mice dual labeled with cardiac and skeletal muscle actin antibodies demonstrated the known increase in skeletal actin protein in BALB/c hearts. The membrane-associated proteins alpha-sarcoglycan and dystrophin could be detected in C57BL/6J mice, but were decreased or absent in mdx mice. With the ability to label whole muscle samples simultaneously with multiple antibodies, flow cytometry may have advantages over conventional methods for certain applications, including assessing the efficacy of potential therapies for muscle diseases.
Collapse
Affiliation(s)
- Connie Jackaman
- Centre for Medical Research, University of Western Australia, Western Australian Institute for Medical Research, Nedlands, Western Australia 6009, Australia.
| | | | | | | | | | | |
Collapse
|
30
|
Xu J, Lecanu L, Tan M, Yao W, Greeson J, Papadopoulos V. The benzamide derivative N-[1-(7-tert-Butyl-1H-indol-3-ylmethyl)-2-(4-cyclopropanecarbonyl-3-methyl-piperazin-1-yl)-2-oxo-ethyl]-4-nitro-benzamide (SP-10) reduces HIV-1 infectivity in vitro by modifying actin dynamics. Antivir Chem Chemother 2007; 17:331-42. [PMID: 17249247 DOI: 10.1177/095632020601700603] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Current treatments for patients infected with HIV are suboptimal. There is a need for new HIV therapies that act through different mechanisms than current treatments. We investigated the in vitro efficacy, safety and mechanism of action of the benzamide derivative N-[1-(7-tert-Butyl-1H-indol-3-ylmethyl)-2-(4-cyclopropanecarbonyl-3-methyl-piperazin-1-yl)-2-oxo-ethyl]-4-nitro-benzamide (SP-10), a potential new HIV treatment. When HIV-1-responsive engineered HeLa cells were pre-incubated for 48 h with either SP-10 or zidovudine (AZT), SP-10 was able to inhibit viral replication at much lower concentrations (IC50 = 0.036 nM) than AZT (IC50 = 27.4 nM). In contrast to AZT, SP-10 also inhibited replication of the multidrug-resistant HIV-1 strain MDR-769 in the HeLa cell model. In co-incubation experiments, SP-10 also inhibited the CCR5-sensitive HIV-1 BaL virus replication in human peripheral blood mononuclear cells. SP-10 displayed very low toxicity compared with current antiviral treatments. Confocal laser scanning microscopy and immunoprecipitation studies showed that SP-10 reduced the expression of CD4 and CCR5 on the surface of the host cell. SP-10 also reduced the level of gp120 binding to the cell surface. Confocal laser scanning microscopy studies showed that SP-10 blocked the formation of actin filaments (F-actin) and altered actin accumulation near the cell surface. These promising results suggest that SP-10 has a novel mechanism of action that enables effective inhibition of HIV-1 binding and cell entry. Further development of SP-10 as a new HIV treatment appears warranted.
Collapse
Affiliation(s)
- Jing Xu
- Department of Biochemistry, Georgetown University Medical Center, Washington, DC, USA
| | | | | | | | | | | |
Collapse
|
31
|
Abstract
Sperm motility is a must for natural fertilization to occur. During their travel through the epididymis, mammalian spermatozoa gradually acquire the ability to move. This is accomplished through a sliding movement of the outer doublet microtubules of the axoneme which is energized by the dynein ATPase. Within its complex structure, the mammalian sperm flagellum contains F-actin and thus, we decided to test in the guinea pig sperm flagellum the role of F-actin in motility. During maturation, capacitation, and the acrosome reaction, a gradual decrease of the relative concentration of F-actin was observed. Motility increased as spermatozoa became able to fertilize. Gelsolin, phalloidin, and KI inhibited sperm motility. Gelsolin canceled sperm motility within 20 min of treatment while 0.6 M KI had immediate effects. Phalloidin diminished hyperactive sperm motility slightly. All three compounds significantly increased the relative concentration of F-actin. Latrunculins are conventional drugs that destabilize the F-actin cytoskeleton. Latrunculin A (LAT A) did not affect sperm motility; but significantly increased F-actin relative concentration. The results suggested that in guinea pig spermatozoa, randomly severing F-actin filaments inhibits flagellar motility; while end filament alteration does not. Thus, specific filament regions seem to be important for sperm motility.
Collapse
Affiliation(s)
- Yenia Azamar
- Departamento de Biología Celular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV), México DF, México
| | | | | |
Collapse
|
32
|
Petrov A, Hooge M, Tyler S. Comparative morphology of the bursal nozzles in acoels (Acoela, Acoelomorpha). J Morphol 2006; 267:634-48. [PMID: 16485278 DOI: 10.1002/jmor.10428] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Systematics of the Acoela is particularly difficult because of the paucity of readily discernible morphological features. In other soft-bodied worms, sclerotized structures, such as copulatory stylets, provide important characters that can be seen in whole mounts, but acoels generally lack such features. Among the few sclerotized structures in acoels are bursal nozzles-tubiform outlets on the seminal bursae that are believed to be conduits (spermatic ducts) through which allosperm are transported to the oocytes. Early classifications of the Acoela used features of the female reproductive system, including bursal nozzles, for distinguishing major groups, but the current system essentially ignores them as too plastic to provide higher-level distinctions. We used confocal and electron microscopy to further characterize bursal nozzles in five acoel species, and found all composed of actin-reinforced extensions of stacked, flat mesenchymal cells. In Notocelis gullmarensis, Aphanostoma bruscai, and Daku woorimensis, the nozzle is a stiffened region of the same cells forming the wall of the bursa. By contrast, in Wulguru cuspidata cells forming the nozzle are distinct from those of the bursa. The so-called bursal cap of A. bruscai and D. woorimensis has small sclerotized disjunct units within it, also composed of stacked, flat, actin-reinforced cells. The nozzle of W. cuspidata, prominent like that of other convolutid acoels, is relatively complex, its actin-reinforced cells sandwiched with secretory cells and its base bearing a "sorting apparatus" of egg-shaped cells that send narrow processes inside the spermatic duct. Cases of sperm inside the nozzle corroborate its assumed role in reproduction. Whereas most nozzles sit at the end of the bursa facing the ovary, in species of Pseudmecynostomum and purportedly in a few other acoels, they sit between the female pore and the bursa, constituting what we call a vaginal nozzle. All bursal nozzles of acoels show a common ground pattern indicating common ancestry, but certain features discerned through electron and confocal microscopy show promise of providing synapomorphies for grouping some species.
Collapse
Affiliation(s)
- Anatoly Petrov
- Department of Biological Sciences, University of Maine, Orono, Maine 04469-5751, USA
| | | | | |
Collapse
|
33
|
Ouyang Y, Wong M, Capani F, Rensing N, Lee CS, Liu Q, Neusch C, Martone ME, Wu JY, Yamada K, Ellisman MH, Choi DW. Transient decrease in F-actin may be necessary for translocation of proteins into dendritic spines. Eur J Neurosci 2006; 22:2995-3005. [PMID: 16367766 PMCID: PMC2286827 DOI: 10.1111/j.1460-9568.2005.04521.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
It remains poorly understood as to how newly synthesized proteins that are required to act at specific synapses are translocated into only selected subsets of potentiated dendritic spines. Here, we report that F-actin, a major component of the skeletal structure of dendritic spines, may contribute to the regulation of synaptic specificity of protein translocation. We found that the stabilization of F-actin blocked the translocation of GFP-CaMKII and inhibited the diffusion of 3-kDa dextran into spines (in 2-3 weeks cultures). Neuronal activation in hippocampal slices and cultured neurons led to an increase in the activation (decrease in the phosphorylation) of the actin depolymerization factor, cofilin, and a decrease in F-actin. Furthermore, the induction of long-term potentiation by tetanic stimulation induced local transient depolymerization of F-actin both in vivo and in hippocampal slices (8-10 weeks), and this local F-actin depolymerization was blocked by APV, a N-methyl-D-aspartate (NMDA) receptor antagonist. These results suggest that F-actin may play a role in synaptic specificity by allowing protein translocation into only potentiated spines, gated through its depolymerization, which is probably triggered by the activation of NMDA receptors.
Collapse
Affiliation(s)
- Yannan Ouyang
- Department of Neurology 8111, Washington University School of Medicine, 660 South Euclid, St. Louis, MO 63110, USA.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Cao W, Tan P, Lee CH, Zhang H, Lu J. A transforming growth factor-beta-induced protein stimulates endocytosis and is up-regulated in immature dendritic cells. Blood 2005; 107:2777-85. [PMID: 16368891 DOI: 10.1182/blood-2005-05-1803] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Dendritic cells (DCs) exhibit distinct functional properties at immature and mature states. To identify genes preferentially regulated in monocyte-derived immature DCs (imDCs), 13 000-element microarrays were hybridized with RNA isolated from imDCs, mature DCs (mDCs), monocytes, and macrophages and a TGF-beta-induced protein (betaig-h3) was identified as being most prominently up-regulated in imDCs. By polymerase chain reaction (PCR), little betaig-h3 mRNA was detected in monocytes and macrophages, but it was abundant in imDCs. On DC activation with LPS, betaig-h3 mRNA became diminished, and in tissues, betaig-h3 mRNA was abundantly expressed in lymphoid-rich tissues such as the spleen, bone marrow, small intestines, and colon. betaig-h3 was expressed in 293T cells and purified as a 70-kDa protein and, by Western blotting, betaig-h3 was predominantly detected in the medium of imDCs. We demonstrate that betaig-h3 binds to macrophages and imDCs but not to mDCs and activates the Rac GTPase in macrophages, stimulating macrophage membrane ruffling and enhancing macrophage endocytosis. imDC endocytosis was also inhibited by purified anti-betaig-h3 antibodies. Therefore, betaig-h3 appears to be selectively up-regulated in imDCs to regulate antigen uptake through endocytosis.
Collapse
Affiliation(s)
- Weiping Cao
- Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Blk MD4, 5 Science Dr 2, Singapore 117597
| | | | | | | | | |
Collapse
|
35
|
Petchprayoon C, Suwanborirux K, Tanaka J, Yan Y, Sakata T, Marriott G. Fluorescent Kabiramides: New Probes to Quantify Actin in Vitro and in Vivo. Bioconjug Chem 2005; 16:1382-9. [PMID: 16287234 DOI: 10.1021/bc050006j] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We present the design, synthesis, and biochemical and spectroscopic characterization of five functional fluorescent conjugates of kabiramide C (KabC), a small molecule biomimetic of gelsolin. The tetramethylrhodamine (TMR), rhodol green (RG), IC5, dapoxyl (DAP), and fluorescein diester (FDE) conjugates of KabC bind specifically to actin at the barbed end in a 1:1 complex. These probes are shown to function in an indistinguishable manner to the unmodified KabC. Various modalities of the fluorescence emission of these KabC probes, including fluorescence anisotropy and fluorescence resonance energy transfer, are used for the development of assays for the rapid determination of G-actin concentration in solution. The TMR-KabC and FDE-KabC probes are cell permeable and provide unique imaging information on the distribution and dynamics of actin filament within living cells.
Collapse
Affiliation(s)
- Chutima Petchprayoon
- Bioactive Marine Natural Products Chemistry Research Unit, Department of Pharmacognosy, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Pathumwan, Bangkok 10330, Thailand
| | | | | | | | | | | |
Collapse
|
36
|
Dumitrescu Pene T, Rosé SD, Lejen T, Marcu MG, Trifaró JM. Expression of various scinderin domains in chromaffin cells indicates that this protein acts as a molecular switch in the control of actin filament dynamics and exocytosis. J Neurochem 2005; 92:780-9. [PMID: 15686479 DOI: 10.1111/j.1471-4159.2004.02907.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Stimulation-induced chromaffin cell cortical F-actin disassembly allows the movement of vesicles towards exocytotic sites. Scinderin (Sc), a Ca2+-dependent protein, controls actin dynamics. Sc six domains have three actin, two PIP2 and two Ca2+-binding sites. F-actin severing activity of Sc is Ca2+-dependent, whereas Sc-evoked actin nucleation is Ca2+-independent. Sc domain role in secretion was studied by co-transfection of human growth hormone (hGH) reporter gene and green fluorescent protein (GFP)-fusion Sc constructs. Cells over-expressing actin severing Sc1-6 or Sc1-2 (first and second actin binding sites) constructs, increased F-actin disassembly and hGH release upon depolarization. Over-expression of nucleating Sc5-6, Sc5 or ScABP3 (third actin site) constructs decreased F-actin disassembly and hGH release upon stimulation. Over-expression of ScL5-6 or ScL5 (lack of third actin site) produced no changes. During secretion, actin sites 1 and 2 are involved in F-actin severing, whereas site 3 is responsible for nucleation (polymerization). Sc functions as a molecular switch in the control of actin (disassembly left arrow over right arrow assembly) and release (facilitation left arrow over right arrow inhibition). The position of the switch (severing left arrow over right arrow nucleation) may be controlled by [Ca2+]i. Thus, increase in [Ca2+]i produced by stimulation-induced Ca2+ entry would increase Sc-evoked cortical F-actin disassembly. Decrease in [Ca2+]i by either organelle sequestration or cell extrusion would favor Sc-evoked actin nucleation.
Collapse
Affiliation(s)
- Teodora Dumitrescu Pene
- Secretory Process Research Program, Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ontario, Canada
| | | | | | | | | |
Collapse
|
37
|
Burnett GR, Rees GD, Steytler DC, Robinson BH. Fluorescence correlation spectroscopy of water-in-oil microemulsions: an application in specific characterisation of droplets containing biomolecules. Colloids Surf A Physicochem Eng Asp 2004. [DOI: 10.1016/j.colsurfa.2004.05.025] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
38
|
Wang Z, Eldstrom JR, Jantzi J, Moore ED, Fedida D. Increased focal Kv4.2 channel expression at the plasma membrane is the result of actin depolymerization. Am J Physiol Heart Circ Physiol 2003; 286:H749-59. [PMID: 14551056 DOI: 10.1152/ajpheart.00398.2003] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Voltage-dependent potassium channel trafficking and localization are regulated by proteins of the cytoskeleton, but the mechanisms by which these occur are still unclear. Using human embryonic kidney (HEK) cells as a heterologous expression system, we tested the role of the actin cytoskeleton in modulating the function of Kv4.2 channels. Pretreatment (>or=1 h) of HEK cells with 5 microM cytochalasin D to disrupt the actin microfilaments greatly augmented whole cell Kv4.2 currents at potentials positive to -20 mV. However, no changes in the voltage dependence of activation and inactivation of macroscopic currents were observed to account for this increase. Similarly, single channel recordings failed to reveal any significant changes in the single channel conductance, open probability, and kinetics. However, the mean patch current was increased from 0.9 +/- 0.2 pA in control to 6.7 +/- 3.0 pA in the presence of cytochalasin D. Imaging experiments revealed a clear increase in the surface expression of the channels and the appearance of "bright spot" features, suggesting that large numbers of channels were being grouped at specific sites. Our data provide clear evidence that increased numbers and altered distribution of Kv4.2 channels at the cell surface are primarily the result of reorganization of the actin cytoskeleton.
Collapse
Affiliation(s)
- Zhuren Wang
- Department of Physiology, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
| | | | | | | | | |
Collapse
|
39
|
Yu JG, Fürst DO, Thornell LE. The mode of myofibril remodelling in human skeletal muscle affected by DOMS induced by eccentric contractions. Histochem Cell Biol 2003; 119:383-93. [PMID: 12712356 DOI: 10.1007/s00418-003-0522-7] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/21/2003] [Indexed: 10/25/2022]
Abstract
Myofibrillar Z-disc streaming and loss of the desmin cytoskeleton are considered the morphological hallmarks of eccentric contraction-induced injury. The latter is contradicted by recent studies where a focal increase of desmin was observed in biopsies taken from human muscles with DOMS. In order to determine the effects of eccentric contraction-induced alterations of the myofibrillar Z-disc, we examined the distribution of alpha-actinin, the Z-disc portion of titin and the nebulin NB2 region in relation to actin and desmin in DOMS biopsies. In biopsies taken 2-3 days and 7-8 days after exercise, we observed a significantly higher number of fibres showing focal areas lacking staining for alpha-actinin, titin and nebulin than in biopsies taken from control or 1 h after exercise. None of these proteins were part of Z-disc streamings but instead they were found in distinct patterns in areas characterised by altered staining for desmin and actin. These were preferentially seen in regions with increased numbers of sarcomeres in parallel myofibrils. We propose that these staining patterns represent different stages of sarcomere formation. These findings therefore support our previous suggestion that muscle fibres subjected to eccentric contractions adapt to unaccustomed activity by the addition of new sarcomeres.
Collapse
Affiliation(s)
- Ji-Guo Yu
- Department of Integrative Medical Biology, Section for Anatomy, Umeå University, Sweden
| | | | | |
Collapse
|
40
|
Tokuraku K, Uyeda TQ. Phalloidin affects the myosin-dependent sliding velocities of actin filaments in a bound-divalent cation dependent manner. J Muscle Res Cell Motil 2002; 22:371-8. [PMID: 11808777 DOI: 10.1023/a:1013120127602] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We examined sliding velocities in vitro of four types of actin filaments, that is, filaments with Ca2+ or Mg2+ bound at the high affinity metal binding site, each with rhodamine phalloidin bound with a high or low stoichiometry. When surfaces coated with a high density of heavy meromyosin (HMM) were used, high stoichiometric concentrations of rhodamine phalloidin reduced sliding velocities of only Ca2+-actin filaments, by 40%. As the HMM density on surfaces was reduced, continuous movement of actin filaments became dependent on the presence of methylcellulose and sliding velocities of all four types became progressively slower. Interestingly, Ca2+-actin filaments with a high stoichiometric concentration of rhodamine phalloidin were the fastest among the four types of filaments on sparse HMM surfaces. In contrast, phalloidin did not affect steady state ATPase activities of HMM in the presence of Ca2+- or Mg2+-actin filaments. We speculate that the reversal of the order of sliding velocities among the four types of actin filaments between high and low densities of HMM relates with different axial elasticity of the actin filaments, so that stiffer filaments move slower on dense HMM surfaces, but faster on sparse surfaces, than elastic ones.
Collapse
Affiliation(s)
- K Tokuraku
- Department of Chemical Science and Engineering, Miyakonojo National College of Technology, Miyazaki, Japan.
| | | |
Collapse
|
41
|
Pfistermüller R, Tyler S. Correlation of fluorescence and electron microscopy of F-actin-containing sensory cells in the epidermis of Convoluta pulchra
(Platyhelminthes: Acoela). ACTA ZOOL-STOCKHOLM 2002. [DOI: 10.1046/j.1463-6395.2002.00095.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
42
|
Makioka A, Kumagai M, Ohtomo H, Kobayashi S, Takeuchi T. Effect of jasplakinolide on the growth, encystation, and actin cytoskeleton of Entamoeba histolytica and Entamoeba invadens. J Parasitol 2001; 87:399-405. [PMID: 11318572 DOI: 10.1645/0022-3395(2001)087[0399:eojotg]2.0.co;2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The effect of jasplakinolide. an actin-polymerizing and filament-stabilizing drug, on the growth, encystation, and actin cytoskeleton of Entamoeba histolytica and Entamoeba invadens was examined. Jasplakinolide inhibited the growth of E. histolytica strain HM-1:IMSS and E. invadens strain IP-1 in a concentration-dependent manner, the latter being more resistant to the drug. The inhibitory effect of jasplakinolide on the growth of E. histolytica trophozoites was reversed by removal of the drug after exposure to 1 microM for 1 day. Encystation of E. invadens as induced in vitro was also inhibited by jasplakinolide. Trophozoites exposed to jasplakinolide in encystation medium for 1 day did not encyst after removal of the drug, whereas those exposed to the drug in growth medium for 7 days did encyst without the drug. The process of cyst maturation was unaffected by jasplakinolide. Large round structures were formed in trophozoites of both amoebae grown with jasplakinolide; these were identified as F-actin aggregates by staining with fluorescent phalloidin. Accumulation in trophozoites of both amoebae of actin aggregates was observed after culture in jasplakinolide. Also, E. invadens cysts formed from trophozoites treated with jasplakinolide contained the actin aggregate. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblot analysis revealed that the jasplakinolide treatment led to an increase in the proportion of F-actin associated with formation of the aggregate. The results suggest that aggregates are formed from the cortical flow of F-actin filaments, and that these filaments would normally be depolymerized but are artificially stabilized by jasplakinolide binding.
Collapse
Affiliation(s)
- A Makioka
- Department of Tropical Medicine, Jikei University School of Medicine, Tokyo, Japan
| | | | | | | | | |
Collapse
|
43
|
Nyitrai M, Hild G, Hartvig N, Belágyi J, Somogyi B. Conformational and dynamic differences between actin filaments polymerized from ATP- or ADP-actin monomers. J Biol Chem 2000; 275:41143-9. [PMID: 11005806 DOI: 10.1074/jbc.m004146200] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Conformational and dynamic properties of actin filaments polymerized from ATP- or ADP-actin monomers were compared by using fluorescence spectroscopic methods. The fluorescence intensity of IAEDANS attached to the Cys(374) residue of actin was smaller in filaments from ADP-actin than in filaments from ATP-actin monomers, which reflected a nucleotide-induced conformational difference in subdomain 1 of the monomer. Radial coordinate calculations revealed that this conformational difference did not modify the distance of Cys(374) from the longitudinal filament axis. Temperature-dependent fluorescence resonance energy transfer measurements between donor and acceptor molecules on Cys(374) of neighboring actin protomers revealed that the inter-monomer flexibility of filaments assembled from ADP-actin monomers were substantially greater than the one of filaments from ATP-actin monomers. Flexibility was reduced by phalloidin in both types of filaments.
Collapse
Affiliation(s)
- M Nyitrai
- Research Group for Fluorescence Spectroscopy, University of Pécs, Pécs, Hungary
| | | | | | | | | |
Collapse
|
44
|
Zhukarev V, Sanger JM, Sanger JW, Goldman YE, Shuman H. Distribution and orientation of rhodamine-phalloidin bound to thin filaments in skeletal and cardiac myofibrils. CELL MOTILITY AND THE CYTOSKELETON 2000; 37:363-77. [PMID: 9258508 DOI: 10.1002/(sici)1097-0169(1997)37:4<363::aid-cm7>3.0.co;2-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Phalloidin staining of muscle does not reflect the known disposition of sarcomeric thin filaments. Quantitative image analysis and steady-state fluorescence polarization microscopy are used to measure the local intensity and orientation of tetramethyl rhodamine-labeled phalloidin (TR-phalloidin) in skinned myofibrils. TR-phalloidin staining of isolated skeletal myofibrils labeled while in rigor reveals fluorescence that is brighter at the pointed ends of the thin filaments and Z lines than it is in the middle of the filaments. In cardiac myofibrils, phalloidin staining is uniform along the lengths of the thin filaments in both relaxed and rigor myofibrils, except in 0.2-micron dark areas on either side of the Z line. Extraction of myosin or tropomyosin-troponin molecules does not change the nonuniform staining. To test whether long-term storage in glycerol changes the binding of phalloidin to thin filaments in myofibrils, minimally permeabilized (briefly skinned) myofibrils, or myofibrils stored in glycerol for at least 7 days (glycerol extraction) were compared. TR-phalloidin was well ordered throughout the sarcomere in briefly skinned skeletal and cardiac myofibrils, but TR-phalloidin bound to the Z line and pointed ends of thin filaments was randomly oriented in glycerol-extracted myofibrils, suggesting that the ends of the thin filaments become disordered after glycerol extraction. In relaxed skeletal myofibrils with sarcomere lengths greater than 3.0 microns, staining was nearly uniform all along the actin filaments. Exogeneous bare actin filaments polymerized from the Z line (Sanger et al., 1984: J. Cell Biol. 98:825-833) in and along the myofibril bind rhodamine phalloidin uniformly. Our results support the hypothesis that nebulin can block the binding of phalloidin to actin in skeletal myofibrils and nebulette can block phalloidin binding to cardiac thin filaments.
Collapse
Affiliation(s)
- V Zhukarev
- Department of Physiology, Pennsylvania Muscle Institute, University of Pennsylvania School of Medicine, Philadelphia 19104, USA
| | | | | | | | | |
Collapse
|
45
|
Eisenbraun MD, Tamir A, Miller RA. Altered composition of the immunological synapse in an anergic, age-dependent memory T cell subset. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 164:6105-12. [PMID: 10843659 DOI: 10.4049/jimmunol.164.12.6105] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In young mice, memory CD4 T lymphocytes with high P-glycoprotein activity (P-gp(high)) are unresponsive to TCR stimulation in vitro but can be activated by PMA plus ionomycin. The proportion of these hyporesponsive cells increases considerably with age. The earliest events in T cell activation were studied in P-gp(high) and P-gp(low) CD4 memory cells at the single-cell level using confocal immunofluorescence methods. Recruitment of both linker for activation of T cells (LAT) and protein kinase C-theta to the immunological synapse, i.e., the site of T cell interaction with stimulator cells, was greatly impaired in P-gp(high) cells from both young and old mice. Translocation of NF-AT to the nucleus, CD69 expression, and proliferative capacity were also diminished to a similar extent in P-gp(high) cells under the same activation conditions. In contrast, movement of c-Cbl to the synapse region occurred in a high proportion of CD4 memory T cells regardless of P-gp subset or age. Moreover, although P-gp(low) cells frequently recruited both c-Cbl and LAT to the APC synapse, cells in the less responsive P-gp(high) subset frequently relocated c-Cbl, but not LAT, to the interface region. In some systems, c-Cbl can act as a negative regulator of receptor-dependent tyrosine kinases, and alterations of c-Cbl to LAT ratios in the P-gp(high) subset may thus contribute to the hyporesponsiveness of this age-dependent, anergic memory cell population.
Collapse
MESH Headings
- ATP Binding Cassette Transporter, Subfamily B, Member 1/biosynthesis
- Adaptor Proteins, Signal Transducing
- Aging/immunology
- Animals
- Antigens, CD/biosynthesis
- Antigens, Differentiation, T-Lymphocyte/biosynthesis
- Biological Transport/immunology
- CD4-Positive T-Lymphocytes/enzymology
- CD4-Positive T-Lymphocytes/immunology
- CD4-Positive T-Lymphocytes/metabolism
- Carrier Proteins/metabolism
- Cell Line
- Cell Nucleus/metabolism
- Clonal Anergy
- DNA-Binding Proteins/metabolism
- Immunologic Memory
- Isoenzymes/metabolism
- Lectins, C-Type
- Male
- Membrane Proteins
- Mice
- Mice, Inbred C57BL
- Mice, Inbred CBA
- Models, Immunological
- NFATC Transcription Factors
- Nuclear Proteins
- Phosphoproteins/metabolism
- Protein Kinase C/metabolism
- Protein Kinase C-theta
- Proto-Oncogene Proteins/metabolism
- Proto-Oncogene Proteins c-cbl
- T-Lymphocyte Subsets/enzymology
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/metabolism
- Transcription Factors/metabolism
- Ubiquitin-Protein Ligases
Collapse
Affiliation(s)
- M D Eisenbraun
- Department of Pathology, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA
| | | | | |
Collapse
|
46
|
Oiwa K, Eccleston JF, Anson M, Kikumoto M, Davis CT, Reid GP, Ferenczi MA, Corrie JE, Yamada A, Nakayama H, Trentham DR. Comparative single-molecule and ensemble myosin enzymology: sulfoindocyanine ATP and ADP derivatives. Biophys J 2000; 78:3048-71. [PMID: 10827983 PMCID: PMC1300888 DOI: 10.1016/s0006-3495(00)76843-3] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Single-molecule and macroscopic reactions of fluorescent nucleotides with myosin have been compared. The single-molecule studies serve as paradigms for enzyme-catalyzed reactions and ligand-receptor interactions analyzed as individual stochastic processes. Fluorescent nucleotides, called Cy3-EDA-ATP and Cy5-EDA-ATP, were derived by coupling the dyes Cy3.29.OH and Cy5.29.OH (compounds XI and XIV, respectively, in, Bioconjug. Chem. 4:105-111)) with 2'(3')-O-[N-(2-aminoethyl)carbamoyl]ATP (EDA-ATP). The ATP(ADP) analogs were separated into their respective 2'- and 3'-O-isomers, the interconversion rate of which was 30[OH(-)] s(-1) (0.016 h(-1) at pH 7.1) at 22 degrees C. Macroscopic studies showed that 2'(3')-O-substituted nucleotides had properties similar to those of ATP and ADP in their interactions with myosin, actomyosin, and muscle fibers, although the ATP analogs did not relax muscle as well as ATP did. Significant differences in the fluorescence intensity of Cy3-nucleotide 2'- and 3'-O-isomers in free solution and when they interacted with myosin were evident. Single-molecule studies using total internal reflection fluorescence microscopy showed that reciprocal mean lifetimes of the nucleotide analogs interacting with myosin filaments were one- to severalfold greater than predicted from macroscopic data. Kinetic and equilibrium data of nucleotide-(acto)myosin interactions derived from single-molecule microscopy now have a biochemical and physiological framework. This is important for single-molecule mechanical studies of motor proteins.
Collapse
Affiliation(s)
- K Oiwa
- Kansai Advanced Research Center, Communications Research Laboratory, Kobe 651-2492, Japan
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Jones KA, Perkins WJ, Lorenz RR, Prakash YS, Sieck GC, Warner DO. F-actin stabilization increases tension cost during contraction of permeabilized airway smooth muscle in dogs. J Physiol 1999; 519 Pt 2:527-38. [PMID: 10457068 PMCID: PMC2269509 DOI: 10.1111/j.1469-7793.1999.0527m.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
1. Dynamic actin reorganization involving actin polymerization and depolymerization may play an important functional role in smooth muscle. 2. This study tested the hypothesis that F-actin stabilization by phalloidin increases tension cost (i.e. ATP hydrolysis rate per unit of isometric force) during Ca2+-induced activation of Triton X-100-permeabilized canine tracheal smooth muscle. 3. Adenosine 5'-triphosphate (ATP) hydrolysis rate was quantified using an enzyme-coupled NADH fluorometric technique, regulatory myosin light chain (rMLC) phosphorylation was measured by Western blot analysis, and maximum unloaded shortening velocity (Vmax) was estimated by interpolation of the force-velocity relationship to zero load during isotonic loading. 4. Maximal activation with 10 microM free Ca2+ induced sustained increases in isometric force, stiffness, and rMLC phosphorylation. However, the increase in ATP hydrolysis rate initially reached peak values, but then declined to steady-state levels above that of the unstimulated muscle. Thus, tension cost decreased throughout steady-state isometric force. 5. Following incubation of permeabilized strips with 50 microM phalloidin for 1 h, the increases in isometric force and stiffness were not sustained despite a sustained increase in rMLC phosphorylation. Also, after an initial decline, tension cost increased throughout activation. Phalloidin had no effect on Vmax during steady-state isometric force or on rMLC phosphorylation. 6. These findings suggest that dynamic reorganization of actin is necessary for optimal energy utilization during contraction of permeabilized airway smooth muscle.
Collapse
Affiliation(s)
- K A Jones
- Departments of Anesthesiology, and Physiology and Biophysics, Mayo Clinic and Mayo Foundation, Rochester, MN 55905, USA.
| | | | | | | | | | | |
Collapse
|
48
|
Abstract
The short actin filaments in the erythrocyte's membrane skeleton are shown to be largely oriented tangent to the lipid bilayer. Actin "proto"-filaments have previously been described as junctional centers intertriangulated by spectrin; however, the protofilaments may simultaneously serve as pinning centers between the network and the overlying bilayer. The latter function now seems of particular importance because near-normal network assembly has been reported with transgenic mouse sphero-erythrocytes that lack the primary linkage protein Band 3. To assess possible physical constraints on actin protofilaments in intact membranes, fluorescence polarization microscopy (FPM) has been used to study rhodamine phalloidin-labeled red cell ghosts. A basis for interpreting FPM images of cells is provided by FPM applied to isolated actin filaments. These are labeled with the same rhodamine probes and imaged at various orientations with respect to the polarizers, including filament orientations perpendicular to the image plane. High aperture and fluorophore conjugation effects are found to be minimal, enabling development of a simple, semi-empirical model which indicates that protofilaments are generally within approximately 20 degrees of the membrane tangent plane.
Collapse
Affiliation(s)
- C Picart
- Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6315, USA
| | | |
Collapse
|
49
|
Sawitzky H, Liebe S, Willingale-Theune J, Menzel D. The anti-proliferative agent jasplakinolide rearranges the actin cytoskeleton of plant cells. Eur J Cell Biol 1999; 78:424-33. [PMID: 10430024 DOI: 10.1016/s0171-9335(99)80085-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In the present study, we have characterized the action of the natural cyclodepsipeptide jasplakinolide (JAS) on the cytoplasmic architecture, actin-based cytoplasmic motility, and the organization of the actin cytoskeleton in selected examples of green algae (Acetabularia, Pseudobryopsis and Nitella) and higher plant cells (Allium bulb scale cells and Sinapis root hairs). JAS was capable of influencing the actin cytoskeleton and inhibiting cytoplasmic streaming in a differential, cell type-specific manner. With the exception of Nitella, two consecutive responses were observed upon incubation with 2.5 microM JAS: In the first phase cytoplasmic streaming increased transiently alongside with minor modifications of the actin cytoskeleton in the form of adventitious actin spots and spikes appearing throughout the cell cortex in addition to the normal actin bundle system typical for each cell type. In the second phase, cytoplasmic streaming stopped and the actin cytoskeleton became heavily reorganized into shorter, straight, more and more randomly oriented bundle segments. JAS exerted severe long-term effects on the actin cytoskeleton when treatments exceeded 30min at a concentration of 2.5 microM. An in situ competition assay using equimolar concentrations of JAS and FITC-phalloidin suggested that JAS has a phalloidin-like action. Effects of JAS were significantly different from those of cytochalasin D with respect to the resulting degree of perturbance of cytoplasmic organization, the distribution of actin filaments and the speed of reversibility.
Collapse
Affiliation(s)
- H Sawitzky
- Max-Planck-Institut für Zellbiologie, Rosenhof, Ladenburg, Germany
| | | | | | | |
Collapse
|
50
|
|