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Kahle ER, Patel N, Sreenivasappa HB, Marcolongo MS, Han L. Targeting cell-matrix interface mechanobiology by integrating AFM with fluorescence microscopy. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2022; 176:67-81. [PMID: 36055517 PMCID: PMC9691605 DOI: 10.1016/j.pbiomolbio.2022.08.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 08/14/2022] [Accepted: 08/18/2022] [Indexed: 06/15/2023]
Abstract
Mechanosensing at the interface of a cell and its surrounding microenvironment is an essential driving force of physiological processes. Understanding molecular activities at the cell-matrix interface has the potential to provide novel targets for improving tissue regeneration and early disease intervention. In the past few decades, the advancement of atomic force microscopy (AFM) has offered a unique platform for probing mechanobiology at this crucial microdomain. In this review, we describe key advances under this topic through the use of an integrated system of AFM (as a biomechanical testing tool) with complementary immunofluorescence (IF) imaging (as an in situ navigation system). We first describe the body of work investigating the micromechanics of the pericellular matrix (PCM), the immediate cell micro-niche, in healthy, diseased, and genetically modified tissues, with a focus on articular cartilage. We then summarize the key findings in understanding cellular biomechanics and mechanotransduction, in which, molecular mechanisms governing transmembrane ion channel-mediated mechanosensing, cytoskeleton remodeling, and nucleus remodeling have been studied in various cell and tissue types. Lastly, we provide an overview of major technical advances that have enabled more in-depth studies of mechanobiology, including the integration of AFM with a side-view microscope, multiple optomicroscopy, a fluorescence recovery after photobleaching (FRAP) module, and a tensile stretching device. The innovations described here have contributed greatly to advancing the fundamental knowledge of extracellular matrix biomechanics and cell mechanobiology for improved understanding, detection, and intervention of various diseases.
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Affiliation(s)
- Elizabeth R Kahle
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA 19104, United States
| | - Neil Patel
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA 19104, United States
| | - Harini B Sreenivasappa
- Cell Imaging Center, Office of Research and Innovation, Drexel University, PA 19104, United States
| | - Michele S Marcolongo
- Department of Mechanical Engineering, Villanova University, Villanova, PA 19085, United States
| | - Lin Han
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA 19104, United States.
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2
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Car J, Krstulović N. Analytical Model for Determination of Size-Distribution of Colloidal Silver Nanoparticles from Surface Plasmon Resonance Wavelength and Dielectric Functions. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:3474. [PMID: 36234602 PMCID: PMC9565655 DOI: 10.3390/nano12193474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 09/28/2022] [Accepted: 09/30/2022] [Indexed: 06/16/2023]
Abstract
In this work it is shown that the size of silver nanoparticles in a colloidal solution can be determined only from the wavelength of the surface plasmon resonance and material and medium dielectric functions. The size dependence of dielectric functions of silver nanoparticles becomes noticeable in nanoparticles which are smaller than 30 nm in size, which is in accordance with Mie scattering theory applicability. The novelty of this work is in the development of an analytical model for the determination of the size of silver nanoparticles derived from applying shift functions to the UV-Vis spectra, resulting in well-known characteristic diameters of log-normal size distribution function. The purpose of these shift functions is the reconstruction of experimental UV-Vis spectra from simulated ones based on the Beer-Lambert law and log-normal distribution function in order to find the mode diameters of colloidal silver nanoparticles. The introduction of Lagrangian analogue of extinction cross section explains the redshift constant characteristic for given nanoparticle material and the size distribution of nanoparticles. Therefore, the size determination of colloidal silver nanoparticles is possible only through UV-Vis spectroscopy.
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3
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Review on the applications of atomic force microscopy imaging in proteins. Micron 2022; 159:103293. [DOI: 10.1016/j.micron.2022.103293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 04/22/2022] [Accepted: 05/06/2022] [Indexed: 11/19/2022]
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4
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Abstract
In this study, the limits of the Euler–Bernoulli theory in micromechanics are explored. Raman spectroscopy, which is extremely accurate and reliable, is employed to study the bending of a microbeam of a length of 191 μm. It is found that at the micro-scale, the Euler–Bernoulli theory remains an exact and consistent tool, and, possibly, other elasticity theories (such as micropolar theory, gradient elasticity theory, and couple stress theory) are not always required to study this phenomenon. More specifically, good correlation was achieved between the theoretical and experimental results, the former acquired via the theoretical equations and the latter obtained with the use of atomic force microscopy and Raman spectroscopy. The exact predicted strain of an atomic force microscope microbeam under bending, by Euler–Bernoulli equations is confirmed by Raman spectroscopy.
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Sousa de Almeida M, Susnik E, Drasler B, Taladriz-Blanco P, Petri-Fink A, Rothen-Rutishauser B. Understanding nanoparticle endocytosis to improve targeting strategies in nanomedicine. Chem Soc Rev 2021; 50:5397-5434. [PMID: 33666625 PMCID: PMC8111542 DOI: 10.1039/d0cs01127d] [Citation(s) in RCA: 327] [Impact Index Per Article: 109.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Indexed: 12/19/2022]
Abstract
Nanoparticles (NPs) have attracted considerable attention in various fields, such as cosmetics, the food industry, material design, and nanomedicine. In particular, the fast-moving field of nanomedicine takes advantage of features of NPs for the detection and treatment of different types of cancer, fibrosis, inflammation, arthritis as well as neurodegenerative and gastrointestinal diseases. To this end, a detailed understanding of the NP uptake mechanisms by cells and intracellular localization is essential for safe and efficient therapeutic applications. In the first part of this review, we describe the several endocytic pathways involved in the internalization of NPs and we discuss the impact of the physicochemical properties of NPs on this process. In addition, the potential challenges of using various inhibitors, endocytic markers and genetic approaches to study endocytosis are addressed along with the principal (semi) quantification methods of NP uptake. The second part focuses on synthetic and bio-inspired substances, which can stimulate or decrease the cellular uptake of NPs. This approach could be interesting in nanomedicine where a high accumulation of drugs in the target cells is desirable and clearance by immune cells is to be avoided. This review contributes to an improved understanding of NP endocytic pathways and reveals potential substances, which can be used in nanomedicine to improve NP delivery.
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Affiliation(s)
- Mauro Sousa de Almeida
- Adolphe Merkle Institute, University of FribourgChemin des Verdiers 41700 FribourgSwitzerland
| | - Eva Susnik
- Adolphe Merkle Institute, University of FribourgChemin des Verdiers 41700 FribourgSwitzerland
| | - Barbara Drasler
- Adolphe Merkle Institute, University of FribourgChemin des Verdiers 41700 FribourgSwitzerland
| | | | - Alke Petri-Fink
- Adolphe Merkle Institute, University of FribourgChemin des Verdiers 41700 FribourgSwitzerland
- Department of Chemistry, University of FribourgChemin du Musée 91700 FribourgSwitzerland
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6
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Miranda A, Gómez-Varela AI, Stylianou A, Hirvonen LM, Sánchez H, De Beule PAA. How did correlative atomic force microscopy and super-resolution microscopy evolve in the quest for unravelling enigmas in biology? NANOSCALE 2021; 13:2082-2099. [PMID: 33346312 DOI: 10.1039/d0nr07203f] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
With the invention of the Atomic Force Microscope (AFM) in 1986 and the subsequent developments in liquid imaging and cellular imaging it became possible to study the topography of cellular specimens under nearly physiological conditions with nanometric resolution. The application of AFM to biological research was further expanded with the technological advances in imaging modes where topographical data can be combined with nanomechanical measurements, offering the possibility to retrieve the biophysical properties of tissues, cells, fibrous components and biomolecules. Meanwhile, the quest for breaking the Abbe diffraction limit restricting microscopic resolution led to the development of super-resolution fluorescence microscopy techniques that brought the resolution of the light microscope comparable to the resolution obtained by AFM. The instrumental combination of AFM and optical microscopy techniques has evolved over the last decades from integration of AFM with bright-field and phase-contrast imaging techniques at first to correlative AFM and wide-field fluorescence systems and then further to the combination of AFM and fluorescence based super-resolution microscopy modalities. Motivated by the many developments made over the last decade, we provide here a review on AFM combined with super-resolution fluorescence microscopy techniques and how they can be applied for expanding our understanding of biological processes.
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Affiliation(s)
- Adelaide Miranda
- International Iberian Nanotechnology Laboratory, Avenida Mestre José Veiga s/n, Braga, Portugal.
| | - Ana I Gómez-Varela
- International Iberian Nanotechnology Laboratory, Avenida Mestre José Veiga s/n, Braga, Portugal. and Department of Applied Physics, University of Santiago de Compostela, E-15782, Santiago de Compostela, Spain.
| | - Andreas Stylianou
- Cancer Biophysics Laboratory, University of Cyprus, Nicosia, Cyprus and School of Sciences, European University Cyprus, Nicosia, Cyprus
| | - Liisa M Hirvonen
- Centre for Microscopy, Characterisation and Analysis (CMCA), The University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia
| | - Humberto Sánchez
- Faculty of Applied Sciences, Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, 2629 HZ, Delft, The Netherlands
| | - Pieter A A De Beule
- International Iberian Nanotechnology Laboratory, Avenida Mestre José Veiga s/n, Braga, Portugal.
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7
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Yadav S, Ta HT, Nguyen N. Mechanobiology in cardiology: Micro‐ and nanotechnologies to probe mechanosignaling. VIEW 2021. [DOI: 10.1002/viw.20200080] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Affiliation(s)
- Sharda Yadav
- Queensland Micro‐ and Nanotechnology Centre Griffith University Nathan Queensland Australia
| | - Hang T. Ta
- Queensland Micro‐ and Nanotechnology Centre Griffith University Nathan Queensland Australia
- School of Environment and Science Griffith University Nathan Queensland Australia
| | - Nam‐Trung Nguyen
- Queensland Micro‐ and Nanotechnology Centre Griffith University Nathan Queensland Australia
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8
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Hu J, Gao M, Wang Z, Chen Y, Song Z, Xu H. Direct imaging of antigen-antibody binding by atomic force microscopy. APPLIED NANOSCIENCE 2020; 11:293-300. [PMID: 32989412 PMCID: PMC7511526 DOI: 10.1007/s13204-020-01558-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Accepted: 09/15/2020] [Indexed: 11/06/2022]
Abstract
Direct observation of antigen–antibody binding at the nanoscale has always been a considerable challenging problem, and researchers have made tremendous efforts on it. In this study, the morphology of biotinylated antibody-specific Immunoglobulin E (IgE) immune complexes has been successfully imaged by atomic force microscopy (AFM) in the tapping-mode. The AFM images indicated that the individual immune complex was composed of an IgE and a biotinylated antibody. Excitingly, it is the first time that we have actually seen the IgE binding to biotinylated antibody. Alternatively, information on the length of IgE, biotinylated antibodies and biotinylated antibody-specific IgE immune complexes were also obtained, respectively. These results indicate the versatility of AFM technology in the identification of antigen–antibody binding. This work not only lays the basis for the direct imaging of the biotinylated antibody-IgE by AFM, but also offers valuable information for studying the targeted therapy and vaccine development in the future.
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Affiliation(s)
- Jing Hu
- Ministry of Education Key Laboratory for Cross-Scale Micro and Nano Manufacturing, Changchun University of Science and Technology, Changchun, 130022 China.,International Research Centre for Nano Handling and Manufacturing of China, Changchun University of Science and Technology, Changchun, 130022 China
| | - Mingyan Gao
- Ministry of Education Key Laboratory for Cross-Scale Micro and Nano Manufacturing, Changchun University of Science and Technology, Changchun, 130022 China.,International Research Centre for Nano Handling and Manufacturing of China, Changchun University of Science and Technology, Changchun, 130022 China
| | - Zuobin Wang
- Ministry of Education Key Laboratory for Cross-Scale Micro and Nano Manufacturing, Changchun University of Science and Technology, Changchun, 130022 China.,International Research Centre for Nano Handling and Manufacturing of China, Changchun University of Science and Technology, Changchun, 130022 China.,JR3CN and IRAC, University of Bedfordshire, Luton, LU1 3JU UK
| | - Yujuan Chen
- Ministry of Education Key Laboratory for Cross-Scale Micro and Nano Manufacturing, Changchun University of Science and Technology, Changchun, 130022 China.,International Research Centre for Nano Handling and Manufacturing of China, Changchun University of Science and Technology, Changchun, 130022 China.,School of Life Sciences, Changchun University of Science and Technology, Changchun, 130022 China
| | - Zhengxun Song
- Ministry of Education Key Laboratory for Cross-Scale Micro and Nano Manufacturing, Changchun University of Science and Technology, Changchun, 130022 China.,International Research Centre for Nano Handling and Manufacturing of China, Changchun University of Science and Technology, Changchun, 130022 China
| | - Hongmei Xu
- Ministry of Education Key Laboratory for Cross-Scale Micro and Nano Manufacturing, Changchun University of Science and Technology, Changchun, 130022 China.,International Research Centre for Nano Handling and Manufacturing of China, Changchun University of Science and Technology, Changchun, 130022 China
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9
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Kiio TM, Park S. Nano-scientific Application of Atomic Force Microscopy in Pathology: from Molecules to Tissues. Int J Med Sci 2020; 17:844-858. [PMID: 32308537 PMCID: PMC7163363 DOI: 10.7150/ijms.41805] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 02/26/2020] [Indexed: 12/28/2022] Open
Abstract
The advantages of atomic force microscopy (AFM) in biological research are its high imaging resolution, sensitivity, and ability to operate in physiological conditions. Over the past decades, rigorous studies have been performed to determine the potential applications of AFM techniques in disease diagnosis and prognosis. Many pathological conditions are accompanied by alterations in the morphology, adhesion properties, mechanical compliances, and molecular composition of cells and tissues. The accurate determination of such alterations can be utilized as a diagnostic and prognostic marker. Alteration in cell morphology represents changes in cell structure and membrane proteins induced by pathologic progression of diseases. Mechanical compliances are also modulated by the active rearrangements of cytoskeleton or extracellular matrix triggered by disease pathogenesis. In addition, adhesion is a critical step in the progression of many diseases including infectious and neurodegenerative diseases. Recent advances in AFM techniques have demonstrated their ability to obtain molecular composition as well as topographic information. The quantitative characterization of molecular alteration in biological specimens in terms of disease progression provides a new avenue to understand the underlying mechanisms of disease onset and progression. In this review, we have highlighted the application of diverse AFM techniques in pathological investigations.
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Affiliation(s)
| | - Soyeun Park
- College of Pharmacy, Keimyung University, 1095 Dalgubeoldaero, Daegu 42601, Republic of Korea
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10
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Haase K, Pelling AE. Investigating cell mechanics with atomic force microscopy. J R Soc Interface 2015; 12:20140970. [PMID: 25589563 PMCID: PMC4345470 DOI: 10.1098/rsif.2014.0970] [Citation(s) in RCA: 216] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 12/18/2014] [Indexed: 12/12/2022] Open
Abstract
Transmission of mechanical force is crucial for normal cell development and functioning. However, the process of mechanotransduction cannot be studied in isolation from cell mechanics. Thus, in order to understand how cells 'feel', we must first understand how they deform and recover from physical perturbations. Owing to its versatility, atomic force microscopy (AFM) has become a popular tool to study intrinsic cellular mechanical properties. Used to directly manipulate and examine whole and subcellular reactions, AFM allows for top-down and reconstitutive approaches to mechanical characterization. These studies show that the responses of cells and their components are complex, and largely depend on the magnitude and time scale of loading. In this review, we generally describe the mechanotransductive process through discussion of well-known mechanosensors. We then focus on discussion of recent examples where AFM is used to specifically probe the elastic and inelastic responses of single cells undergoing deformation. We present a brief overview of classical and current models often used to characterize observed cellular phenomena in response to force. Both simple mechanistic models and complex nonlinear models have been used to describe the observed cellular behaviours, however a unifying description of cell mechanics has not yet been resolved.
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Affiliation(s)
- Kristina Haase
- Department of Physics, Centre for Interdisciplinary NanoPhysics, MacDonald Hall, University of Ottawa, 150 Louis Pasteur, Ottawa, Ontario, Canada
| | - Andrew E Pelling
- Department of Physics, Centre for Interdisciplinary NanoPhysics, MacDonald Hall, University of Ottawa, 150 Louis Pasteur, Ottawa, Ontario, Canada Department of Biology, Gendron Hall, 30 Marie Curie, University of Ottawa, Ottawa, Ontario, Canada Institute for Science Society and Policy, Desmarais Building, 55 Laurier Ave. East, University of Ottawa, Ottawa, Ontario, Canada K1N 6N5
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11
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Measurement of cationic and intracellular modulation of integrin binding affinity by AFM-based nanorobot. Biophys J 2014; 105:40-7. [PMID: 23823222 DOI: 10.1016/j.bpj.2013.05.052] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Revised: 05/12/2013] [Accepted: 05/30/2013] [Indexed: 11/23/2022] Open
Abstract
Integrins are dynamic transmembrane cation-dependent heterodimers that both anchor cells in position and transduce signals into and out of cells. We used an atomic force microscope (AFM)-based nanorobotic system to measure integrin-binding forces in intact human intestinal epithelial Caco-2 cells. The AFM-based nanorobot enables human-directed, high-accuracy probe positioning and site-specific investigations. Functionalizing the AFM probe with an arginine-glycine-aspartate (RGD)-containing sequence (consensus binding sequence for integrins) allowed us to detect a series of peptide-cell membrane interactions with a median binding force of 115.1 ± 4.9 pN that were not detected in control interactions. Chelating divalent cations from the culture medium abolished these interactions, as did inhibiting intracellular focal adhesion kinase (FAK) using Y15. Adding 1 mM Mg(2+) to the medium caused a rightward shift in the force-binding curve. Adding 1 mM Ca(2+) virtually abolished the RGD-membrane specific interactions and blocked the Mg(2+) effects. Cell adhesion assays demonstrated parallel effects of divalent cations and the FAK inhibitor on cell adhesion. These results demonstrate direct modulation of integrin-binding affinity by both divalent cations and intracellular signal inhibition. Additionally, three binding states (nonspecific, specific inactivated, and specific activated) were delineated from affinity measurements. Although other research has assumed that this process of integrin conformational change causes altered ligand binding, in this work we directly measured these three states in individual integrins in a physiologically based study.
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12
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Ke C, Jin H, Cai J. AFM studied the effect of celastrol on β1 integrin-mediated HUVEC adhesion and migration. SCANNING 2013; 35:316-326. [PMID: 23239560 DOI: 10.1002/sca.21070] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 11/13/2012] [Accepted: 11/14/2012] [Indexed: 06/01/2023]
Abstract
Integrin-mediated human umbilical vein endothelial cells (HUVECs) adhesion to the extracellular matrix plays a fundamental role in tumor-induced angiogenesis. Celastrol, a traditional Chinese medicine plant, has possessed anticancer and suppressed angiogenesis activities. Here, the mechanism underling the antiangiogenesis capacity of celastrol was investigated by exploring the effect of celastrol on β1(CD29) integrin-mediated cell adhesion and migration. Flow cytometry results showed that the HUVECs highly expressed CD29 and cell adhesion assay indicated that celastrol specifically inhibited the adhesion of HUVECs to fibronectin (FN) without affecting nonspecific adhesion to poly-L-lysine (PLL). After cell FN adhesion being inhibited, the cell surface nanoscale structure and adhesion force were detected by atomic force microscope (AFM). High-resolution imaging revealed that cell morphology and ultrastructure changed a lot after being treated with celastrol. The membrane average roughness (Ra) and the major forces were decreased from 31.34 ± 4.56 nm, 519.60 ± 82.86 pN of 0 μg/ml celastrol to 18.47 ± 6.53 nm, 417.79 ± 53.35 pN of 4.0 μg/ml celastrol, 10.54 ± 2.85 nm, 258.95 ± 38.98 pN of 8.0 μg/ml celastrol, respectively. Accompanying with the decrease of adhesion force, the actin cytoskeleton in the cells was obviously disturbed by the celastrol. All of these changes influenced the migration of HUVECs from the wound-healing migration assay. Taken together, our results suggest that celastrol can be as an inhibitor of HUVEC adhesion to FN. This work provides a novel approach to inhibition of tumor angiogenesis and tumor growth.
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Affiliation(s)
- Changhong Ke
- Department of Chemistry, College of Life Science and Technology, Jinan University, Guangzhou, China
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Jiang J, Jin H, Liu L, Pi J, Yang F, Cai J. Curcumin disturbed cell-cycle distribution of HepG2 cells via cytoskeletal arrangement. SCANNING 2013; 35:253-260. [PMID: 23070725 DOI: 10.1002/sca.21058] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Revised: 09/05/2012] [Accepted: 09/05/2012] [Indexed: 06/01/2023]
Abstract
Due to its extensive antitumor activity, curcumin has been focused on by more researchers. But, its antiproliferative mechanisms are still unknown. Here we studied the antiproliferative activity of curcumin in human liver cancer HepG2 cells. In order to analyze the cytotoxic activity and anticancer mechanisms of curcumin, we carried out cytotoxicity tests using 3-[4,5-dimethyl-2-thiazolyl]-2,5 diphenyltetrazolium bromide (MTT) assay. The HepG2 cell cycle distribution and the expression of tubulin were detected by flow cytometry. Alterations in morphological and cytoskeletal properties of HepG2 cells were investigated using atomic force microscopy (AFM). Simultaneously, the effects of curcumin on the growth and proliferation of HepG2 cells were also assayed by MTT method. Cells were incubated with different doses of curcumin (0-80 μmol/l) for 24 h, the cell viability decreased from 91.10 ± 3.2% to 10.84 ± 4.0%, and the 50% inhibiting concentration (IC50 ) was 23.15 ± 0.37 μmol/l. Moreover, flow cytometry quantitatively detected that curcumin treatment resulted in a dose-dependent accumulation of HepG2 cells in G2/M phase with concomitant losses from G0/G1 phase, so curcumin caused cell-cycle arrest at G2/M phase. Furthermore, we discovered that curcumin was able to upregulate the expression of tubulin in HepG2 cells. In addition, AFM analysis including cell-membrane structure and cytoskeleton networks is helpful to explain the relationship between the changes of cells and external pharmacologic stimulation.
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Affiliation(s)
- Jinhuan Jiang
- Department of Chemistry, College of Life Science and Technology, Jinan University, Guangzhou, China
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14
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Andolfi L, Trevisan E, Zweyer M, Prato S, Troian B, Vita F, Borelli V, Soranzo MR, Melato M, Zabucchi G. The crocidolite fibres interaction with human mesothelial cells as investigated by combining electron microscopy, atomic force and scanning near-field optical microscopy. J Microsc 2013; 249:173-83. [PMID: 23305229 DOI: 10.1111/jmi.12006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In this study, we have performed a morphological analysis of crocidolite fibres interaction with mesothelial cells (MET5A) by combining conventional electron microscopy with atomic force (AFM) and scanning near-field optical microscopy (SNOM). After 6-h exposure at a crocidolite dose of 5 μg cm(-2), 90% of MET5A cells interact with fibres that under these conditions have a low cytotoxic effect. SEM images point out that fibres can be either engulfed by the cells that lose their typical morphology or they can accumulate over or partially inside the cells, which preserve their typical spread morphology. By using AFM we are able to directly visualize the entry-site of nanometric-sized fibres at the plasma membrane of the spread mesothelial cells. More importantly, the crocidolite fibres that are observed to penetrate the plasma membrane in SNOM topography can be simultaneously followed beneath the cell surface in the SNOM optical images. The analysis of SNOM data demonstrates the entrance of crocidolite fibres in proximity of nuclear compartment, as observed also in the TEM images. Our findings indicate that the combination of conventional electron microscopy with novel nanoscopic techniques can be considered a promising approach to achieve a comprehensive morphological description of the interaction between asbestos fibres and mesothelial cells that represents the early event in fibre pathogenesis.
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Affiliation(s)
- Laura Andolfi
- Clinical Department of Medical, Chirurgical and Healthy Science, University of Trieste, Trieste 34127, Italy
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15
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Schoewel V, Marg A, Kunz S, Overkamp T, Siegert Carrazedo R, Zacharias U, Daniel PT, Spuler S. Dysferlin-peptides reallocate mutated dysferlin thereby restoring function. PLoS One 2012. [PMID: 23185377 PMCID: PMC3502493 DOI: 10.1371/journal.pone.0049603] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mutations in the dysferlin gene cause the most frequent adult-onset limb girdle muscular dystrophy, LGMD2B. There is no therapy. Dysferlin is a membrane protein comprised of seven, beta-sheet enriched, C2 domains and is involved in Ca2+dependent sarcolemmal repair after minute wounding. On the protein level, point mutations in DYSF lead to misfolding, aggregation within the endoplasmic reticulum, and amyloidogenesis. We aimed to restore functionality by relocating mutant dysferlin. Therefore, we designed short peptides derived from dysferlin itself and labeled them to the cell penetrating peptide TAT. By tracking fluorescently labeled short peptides we show that these dysferlin-peptides localize in the endoplasmic reticulum. There, they are capable of reducing unfolded protein response stress. We demonstrate that the mutant dysferlin regains function in membrane repair in primary human myotubes derived from patients’ myoblasts by the laser wounding assay and a novel technique to investigate membrane repair: the interventional atomic force microscopy. Mutant dysferlin abuts to the sarcolemma after peptide treatment. The peptide-mediated approach has not been taken before in the field of muscular dystrophies. Our results could redirect treatment efforts for this condition.
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Affiliation(s)
- Verena Schoewel
- Muscle Research Unit, Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Andreas Marg
- Muscle Research Unit, Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Severine Kunz
- Muscle Research Unit, Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Tim Overkamp
- Clinical and Molecular Oncology, University Medical Center Charité, Campus Berlin-Buch, Berlin, Germany
| | - Romy Siegert Carrazedo
- Muscle Research Unit, Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Ute Zacharias
- Muscle Research Unit, Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Peter T. Daniel
- Clinical and Molecular Oncology, University Medical Center Charité, Campus Berlin-Buch, Berlin, Germany
| | - Simone Spuler
- Muscle Research Unit, Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and Max Delbrück Center for Molecular Medicine, Berlin, Germany
- * E-mail:
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