1
|
Sau A, Sanyal S, Bera K, Sen S, Mitra AK, Pal U, Chakraborty PK, Ganguly S, Satpati B, Das C, Basu S. DNA Damage and Apoptosis Induction in Cancer Cells by Chemically Engineered Thiolated Riboflavin Gold Nanoassembly. ACS APPLIED MATERIALS & INTERFACES 2018; 10:4582-4589. [PMID: 29338178 DOI: 10.1021/acsami.7b18837] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Herein we have engineered a smart nuclear targeting thiol-modified riboflavin-gold nano assembly, RfS@AuNPs, which accumulates selectively in the nucleus without any nuclear-targeting peptides (NLS/RGD) and shows photophysically in vitro DNA intercalation. A theoretical model using Molecular Dynamics has been developed to probe the mechanism of formation and stability as well as dynamics of the RfS@AuNPs in aqueous solution and within the DNA microenvironment. The RfS@AuNPs facilitate the binucleated cell formation that is reflected in the significant increase of DNA damage marker, γ-H2AX as well as the arrest of most of the HeLa cells at the pre-G1 phase indicating cell death. Moreover, a significant upregulation of apoptotic markers confirms that the cell death occurs through the apoptotic pathway. Analyses of the microarray gene expression of RfS@AuNPs treated HeLa cells show significant alterations in vital biological processes necessary for cell survival. Taken together, our study reports a unique nuclear targeting mechanism through targeting the riboflavin receptors, which are upregulated in cancer cells and induce apoptosis in the targeted cells.
Collapse
Affiliation(s)
| | | | | | | | - Amrit Krishna Mitra
- Department of Chemistry, Government General Degree College, Singur, Hooghly, West Bengal 712409, India
| | | | | | | | | | | | | |
Collapse
|
2
|
Griesinger C, Desprez B, Coecke S, Casey W, Zuang V. Validation of Alternative In Vitro Methods to Animal Testing: Concepts, Challenges, Processes and Tools. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 856:65-132. [PMID: 27671720 DOI: 10.1007/978-3-319-33826-2_4] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
This chapter explores the concepts, processes, tools and challenges relating to the validation of alternative methods for toxicity and safety testing. In general terms, validation is the process of assessing the appropriateness and usefulness of a tool for its intended purpose. Validation is routinely used in various contexts in science, technology, the manufacturing and services sectors. It serves to assess the fitness-for-purpose of devices, systems, software up to entire methodologies. In the area of toxicity testing, validation plays an indispensable role: "alternative approaches" are increasingly replacing animal models as predictive tools and it needs to be demonstrated that these novel methods are fit for purpose. Alternative approaches include in vitro test methods, non-testing approaches such as predictive computer models up to entire testing and assessment strategies composed of method suites, data sources and decision-aiding tools. Data generated with alternative approaches are ultimately used for decision-making on public health and the protection of the environment. It is therefore essential that the underlying methods and methodologies are thoroughly characterised, assessed and transparently documented through validation studies involving impartial actors. Importantly, validation serves as a filter to ensure that only test methods able to produce data that help to address legislative requirements (e.g. EU's REACH legislation) are accepted as official testing tools and, owing to the globalisation of markets, recognised on international level (e.g. through inclusion in OECD test guidelines). Since validation creates a credible and transparent evidence base on test methods, it provides a quality stamp, supporting companies developing and marketing alternative methods and creating considerable business opportunities. Validation of alternative methods is conducted through scientific studies assessing two key hypotheses, reliability and relevance of the test method for a given purpose. Relevance encapsulates the scientific basis of the test method, its capacity to predict adverse effects in the "target system" (i.e. human health or the environment) as well as its applicability for the intended purpose. In this chapter we focus on the validation of non-animal in vitro alternative testing methods and review the concepts, challenges, processes and tools fundamental to the validation of in vitro methods intended for hazard testing of chemicals. We explore major challenges and peculiarities of validation in this area. Based on the notion that validation per se is a scientific endeavour that needs to adhere to key scientific principles, namely objectivity and appropriate choice of methodology, we examine basic aspects of study design and management, and provide illustrations of statistical approaches to describe predictive performance of validated test methods as well as their reliability.
Collapse
Affiliation(s)
| | | | - Sandra Coecke
- European Commission, Joint Research Centre (JRC),, Ispra, Italy
| | - Warren Casey
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA.,Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM), Washington, DC, USA
| | - Valérie Zuang
- European Commission, Joint Research Centre (JRC),, Ispra, Italy.
| |
Collapse
|
3
|
Atkin-Smith GK, Tixeira R, Paone S, Mathivanan S, Collins C, Liem M, Goodall KJ, Ravichandran KS, Hulett MD, Poon IK. A novel mechanism of generating extracellular vesicles during apoptosis via a beads-on-a-string membrane structure. Nat Commun 2015; 6:7439. [PMID: 26074490 PMCID: PMC4490561 DOI: 10.1038/ncomms8439] [Citation(s) in RCA: 240] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 05/07/2015] [Indexed: 12/15/2022] Open
Abstract
Disassembly of apoptotic cells into smaller fragments (a form of extracellular vesicle called apoptotic bodies) can facilitate removal of apoptotic debris and intercellular communication. However, the mechanism underpinning this process is unclear. While observing monocytes undergoing apoptosis by time-lapse microscopy, we discovered a new type of membrane protrusion that resembles a 'beads-on-a-string' structure. Strikingly, the 'beads' are frequently sheared off the 'string' to form apoptotic bodies. Generation of apoptotic bodies via this mechanism can facilitate a sorting process and results in the exclusion of nuclear contents from apoptotic bodies. Mechanistically, generation of 'beads-on-a-string' protrusion is controlled by the level of actomyosin contraction and apoptopodia formation. Furthermore, in an unbiased drug screen, we identified the ability of sertraline (an antidepressant) to block the formation of 'beads-on-a-string' protrusions and apoptotic bodies. These data uncover a new mechanism of apoptotic body formation in monocytes and also compounds that can modulate this process.
Collapse
Affiliation(s)
- Georgia K. Atkin-Smith
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia
| | - Rochelle Tixeira
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia
| | - Stephanie Paone
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia
| | - Suresh Mathivanan
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia
| | - Christine Collins
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia
| | - Michael Liem
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia
| | - Katharine J. Goodall
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia
| | - Kodi S. Ravichandran
- Department of Microbiology, Center for Cell Clearance, University of Virginia, Charlottesville, Virginia 22908, USA
| | - Mark D. Hulett
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia
| | - Ivan K.H. Poon
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia
| |
Collapse
|
4
|
Lee H, Kim GM, Choi JH, Lee JK, Bae JS, Jin HK. Highly reproducible quantification of apoptotic cells using micropatterned culture of neurons. Anal Biochem 2015; 469:65-70. [PMID: 25277814 DOI: 10.1016/j.ab.2014.09.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2014] [Revised: 09/11/2014] [Accepted: 09/22/2014] [Indexed: 10/24/2022]
Abstract
The quantification of apoptotic cells is an integral component of many cell-based assays in biological studies. However, current methods for quantifying apoptotic cells using conventional random cultures have shown great limitations, especially for the quantification of primary neurons. Randomly distributed neurons under primary culture conditions can lead to biased estimates, and vastly different estimates of cell numbers can be produced within the same experiment. In this study, we developed a simple, accurate, and reliable technique for quantifying apoptotic neurons by means of micropatterned cell cultures. A polydimethylsiloxane (PDMS) microstencil was used as a physical mask for micropatterning cell cultures, and primary granular neurons (GNs) were successfully cultured within the micropattern-confined regions and homogeneously distributed over the entire field of each pattern. As compared with the conventional method based on random cultures, the micropatterned culture method allowed for highly reproducible quantification of apoptotic cells. These results were also confirmed by using GNs derived from mice with neurodegeneration. We hope that this micropatterning method based on the use of a PDMS microstencil can overcome the technical obstacles existing in current biological studies and will serve as a powerful tool for facilitating the study of apoptosis-involved diseases.
Collapse
Affiliation(s)
- Hyun Lee
- Stem Cell Neuroplasticity Research Group, Kyungpook National University, Daegu 702-701, South Korea; Department of Laboratory Animal Medicine, Cell and Matrix Research Institute, College of Veterinary Medicine, Kyungpook National University, Daegu 702-701, South Korea
| | - Gyu Man Kim
- School of Mechanical Engineering, Kyungpook National University, Daegu 702-701, South Korea
| | - Jin Ho Choi
- School of Mechanical Engineering, Kyungpook National University, Daegu 702-701, South Korea
| | - Jong Kil Lee
- Stem Cell Neuroplasticity Research Group, Kyungpook National University, Daegu 702-701, South Korea; Department of Physiology, Cell and Matrix Research Institute, School of Medicine, Kyungpook National University, Daegu 700-842, South Korea; Department of Biomedical Science, BK21 Plus KNU Biomedical Convergence Program, Kyungpook National University, Daegu 700-842, South Korea
| | - Jae-Sung Bae
- Stem Cell Neuroplasticity Research Group, Kyungpook National University, Daegu 702-701, South Korea; Department of Physiology, Cell and Matrix Research Institute, School of Medicine, Kyungpook National University, Daegu 700-842, South Korea; Department of Biomedical Science, BK21 Plus KNU Biomedical Convergence Program, Kyungpook National University, Daegu 700-842, South Korea.
| | - Hee Kyung Jin
- Stem Cell Neuroplasticity Research Group, Kyungpook National University, Daegu 702-701, South Korea; Department of Laboratory Animal Medicine, Cell and Matrix Research Institute, College of Veterinary Medicine, Kyungpook National University, Daegu 702-701, South Korea.
| |
Collapse
|
5
|
Effects on channel properties and induction of cell death induced by c-terminal truncations of pannexin1 depend on domain length. J Membr Biol 2015; 248:285-94. [PMID: 25567359 DOI: 10.1007/s00232-014-9767-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 12/22/2014] [Indexed: 10/24/2022]
Abstract
Pannexin1 (Panx1) is an integral membrane protein and known to form multifunctional hexameric channels. Recently, Panx1 was identified to be responsible for the release of ATP and UTP from apoptotic cells after site-specific proteolysis by caspases 3/7. Cleavage at the carboxy-terminal (CT) position aa 376-379 irreversibly opens human Panx1 channels and leads to the release of the respective nucleotides resulting in recruitment of macrophages and in subsequent activation of the immunologic response. The fact that cleavage of the CT at this particular residues terminates in a permanently open channel raised the issue of functional relevance of the CT of Panx1 for regulating channel properties. To analyze the impact of the CT on channel gating, we generated 14 truncated versions of rat Panx1 cleaved at different positions in the C-terminus. This allowed elaboration of the influence of defined residues on channel formation, voltage-dependent gating, execution of cell mortality, and susceptibility to the Panx1 inhibitor carbenoxolone. We demonstrate that expression of Panx1 proteins, which were truncated to lengths between 370 and 393 residues, induces differential effects after expression in Xenopus laevis oocytes as well as in Neuro2A cells with strongest impact downstream the caspase 3/7 cleavage site.
Collapse
|
6
|
Adler EM. Of volume regulation, arterial constriction, and apoptotic breakdown. J Gen Physiol 2014; 143:525-6. [PMID: 24778427 PMCID: PMC4003187 DOI: 10.1085/jgp.201411205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
|