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Khalenkow D, Tormo AD, De Meyst A, Van Der Meeren L, Verduijn J, Rybarczyk J, Vanrompay D, Le Thomas N, Skirtach AG. Chlamydia psittaci infected cell studies by 4Pi Raman and atomic force microscopy. Microscopy (Oxf) 2024; 73:335-342. [PMID: 38527311 DOI: 10.1093/jmicro/dfae011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 12/22/2023] [Accepted: 02/15/2024] [Indexed: 03/27/2024] Open
Abstract
Chlamydia psittaci is an avian bacterial pathogen that can cause atypical pneumonia in humans via zoonotic transmission. It is a Gram-negative intracellular bacterium that proliferates inside membrane bound inclusions in the cytoplasm of living eukaryotic cells. The study of such cells with C. psittaci inside without destroying them poses a significant challenge. We demonstrated in this work the utility of a combined multitool approach to analyze such complex samples. Atomic force microscopy was applied to obtain high-resolution images of the surface of infected cells upon entrance of bacteria. Atomic force microscopy scans revealed the morphological changes of the cell membrane of Chlamydia infected cells such as changes in roughness of cell membrane and the presence of micro vesicles. 4Pi Raman microscopy was used to image and probe the molecular composition of intracellular bacteria inside intact cells. Information about the structure of the inclusion produced by C. psittaci was obtained and it was found to have a similar molecular fingerprint as that of an intracellular lipid droplet but with less proteins and unsaturated lipids. The presented approach demonstrates complementarity of various microscopy-based approaches and might be useful for characterization of intracellular bacteria.
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Affiliation(s)
- Dmitry Khalenkow
- Department of Biotechnology, Faculty of Bioscience Engineering, Ghent University, Ghent 9000, Belgium
| | - Alejandro Diaz Tormo
- Photonics Research Group, Department of Information Technology, IMEC & Center for Nano-and Biophotonics, Ghent University, Ghent 9000, Belgium
| | - Anne De Meyst
- Department of Animal Sciences and Aquatic Ecology, Faculty of Bioscience Engineering, Ghent University, Ghent 9000, Belgium
| | - Louis Van Der Meeren
- Department of Biotechnology, Faculty of Bioscience Engineering, Ghent University, Ghent 9000, Belgium
| | - Joost Verduijn
- Department of Biotechnology, Faculty of Bioscience Engineering, Ghent University, Ghent 9000, Belgium
| | - Joanna Rybarczyk
- Department of Animal Sciences and Aquatic Ecology, Faculty of Bioscience Engineering, Ghent University, Ghent 9000, Belgium
| | - Daisy Vanrompay
- Department of Animal Sciences and Aquatic Ecology, Faculty of Bioscience Engineering, Ghent University, Ghent 9000, Belgium
| | - Nicolas Le Thomas
- Photonics Research Group, Department of Information Technology, IMEC & Center for Nano-and Biophotonics, Ghent University, Ghent 9000, Belgium
| | - Andre G Skirtach
- Department of Biotechnology, Faculty of Bioscience Engineering, Ghent University, Ghent 9000, Belgium
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Martins C, Magalhães S, Almeida I, Neto V, Rebelo S, Nunes A. Metabolomics to Study Human Aging: A Review. Curr Mol Med 2024; 24:457-477. [PMID: 37026499 DOI: 10.2174/1566524023666230407123727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 02/17/2023] [Accepted: 02/17/2023] [Indexed: 04/08/2023]
Abstract
In the last years, with the increase in the average life expectancy, the world's population is progressively aging, which entails social, health and economic problems. In this sense, the need to better understand the physiology of the aging process becomes an urgent need. Since the study of aging in humans is challenging, cellular and animal models are widely used as alternatives. Omics, namely metabolomics, have emerged in the study of aging, with the aim of biomarker discovering, which may help to uncomplicate this complex process. This paper aims to summarize different models used for aging studies with their advantages and limitations. Also, this review gathers the published articles referring to biomarkers of aging already discovered using metabolomics approaches, comparing the results obtained in the different studies. Finally, the most frequently used senescence biomarkers are described, along with their importance in understanding aging.
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Affiliation(s)
- Claudia Martins
- Department of Medical Sciences, iBiMED: Institute of Biomedicine, University of Aveiro, Agra do Crasto, Aveiro 3810-193, Portugal
| | - Sandra Magalhães
- Department of Surgery and Physiology, Faculty of Medicine, UnIC@RISE, Cardiovascular Research & Development Centre, University of Porto, Alameda Prof. Hernâni Monteiro, Porto 4200-319, Portugal
| | - Idália Almeida
- Department of Medical Sciences, iBiMED: Institute of Biomedicine, University of Aveiro, Agra do Crasto, Aveiro 3810-193, Portugal
- CICECO: Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, Campus Universitário de Santiago, Aveiro 3810-193, Portugal
| | - Vanessa Neto
- Department of Medical Sciences, iBiMED: Institute of Biomedicine, University of Aveiro, Agra do Crasto, Aveiro 3810-193, Portugal
| | - Sandra Rebelo
- Department of Medical Sciences, iBiMED: Institute of Biomedicine, University of Aveiro, Agra do Crasto, Aveiro 3810-193, Portugal
| | - Alexandra Nunes
- Department of Medical Sciences, iBiMED: Institute of Biomedicine, University of Aveiro, Agra do Crasto, Aveiro 3810-193, Portugal
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3
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Wilkins JM, Gakh O, Guo Y, Popescu B, Staff NP, Lucchinetti CF. Biomolecular alterations detected in multiple sclerosis skin fibroblasts using Fourier transform infrared spectroscopy. Front Cell Neurosci 2023; 17:1223912. [PMID: 37744877 PMCID: PMC10512183 DOI: 10.3389/fncel.2023.1223912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 08/14/2023] [Indexed: 09/26/2023] Open
Abstract
Multiple sclerosis (MS) is the leading cause of non-traumatic disability in young adults. New avenues are needed to help predict individuals at risk for developing MS and aid in diagnosis, prognosis, and outcome of therapeutic treatments. Previously, we showed that skin fibroblasts derived from patients with MS have altered signatures of cell stress and bioenergetics, which likely reflects changes in their protein, lipid, and biochemical profiles. Here, we used Fourier transform infrared (FTIR) spectroscopy to determine if the biochemical landscape of MS skin fibroblasts were altered when compared to age- and sex-matched controls (CTRL). More so, we sought to determine if FTIR spectroscopic signatures detected in MS skin fibroblasts are disease specific by comparing them to amyotrophic lateral sclerosis (ALS) skin fibroblasts. Spectral profiling of skin fibroblasts from MS individuals suggests significant alterations in lipid and protein organization and homeostasis, which may be affecting metabolic processes, cellular organization, and oxidation status. Sparse partial least squares-discriminant analysis of spectral profiles show that CTRL skin fibroblasts segregate well from diseased cells and that changes in MS and ALS may be unique. Differential changes in the spectral profile of CTRL, MS, and ALS cells support the development of FTIR spectroscopy to detect biomolecular modifications in patient-derived skin fibroblasts, which may eventually help establish novel peripheral biomarkers.
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Affiliation(s)
| | - Oleksandr Gakh
- Department of Neurology, Mayo Clinic, Rochester, MN, United States
| | - Yong Guo
- Department of Neurology, Mayo Clinic, Rochester, MN, United States
| | - Bogdan Popescu
- Department of Anatomy, Physiology, and Pharmacology, University of Saskatchewan, Saskatoon, SK, Canada
- Cameco MS Neuroscience Research Center, University of Saskatchewan, Saskatoon, SK, Canada
| | - Nathan P. Staff
- Department of Neurology, Mayo Clinic, Rochester, MN, United States
| | - Claudia F. Lucchinetti
- Department of Neurology, Mayo Clinic, Rochester, MN, United States
- Center for Multiple Sclerosis and Autoimmune Neurology, Mayo Clinic, Rochester, MN, United States
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4
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Zhang W, Karagiannidis I, Van Vliet EDS, Yao R, Beswick EJ, Zhou A. Granulocyte colony-stimulating factor promotes an aggressive phenotype of colon and breast cancer cells with biochemical changes investigated by single-cell Raman microspectroscopy and machine learning analysis. Analyst 2021; 146:6124-6131. [PMID: 34543367 PMCID: PMC8631005 DOI: 10.1039/d1an00938a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Granulocyte colony-stimulating factor (G-CSF) is produced at high levels in several cancers and is directly linked with metastasis in gastrointestinal (GI) cancers. In order to further understand the alteration of molecular compositions and biochemical features triggered by G-CSF treatment at molecular and cell levels, we sought to investigate the long term treatment of G-CSF on colon and breast cancer cells measured by label-free, non-invasive single-cell Raman microspectroscopy. Raman spectrum captures the molecule-specific spectral signatures ("fingerprints") of different biomolecules presented on cells. In this work, mouse breast cancer line 4T1 and mouse colon cancer line CT26 were treated with G-CSF for 7 weeks and subsequently analyzed by machine learning based Raman spectroscopy and gene/cytokine expression. The principal component analysis (PCA) identified the Raman bands that most significantly changed between the control and G-CSF treated cells. Notably, here we proposed the concept of aggressiveness score, which can be derived from the posterior probability of linear discriminant analysis (LDA), for quantitative spectral analysis of tumorigenic cells. The aggressiveness score was effectively applied to analyze and differentiate the overall cell biochemical changes of G-CSF-treated two model cancer cells. All these tumorigenic progressions suggested by Raman analysis were confirmed by pro-tumorigenic cytokine and gene analysis. A high correlation between gene expression data and Raman spectra highlights that the machine learning based non-invasive Raman spectroscopy offers emerging and powerful tools to better understand the regulation mechanism of cytokines in the tumor microenvironment that could lead to the discovery of new targets for cancer therapy.
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Affiliation(s)
- Wei Zhang
- Department of Biological Engineering, Utah State University, Logan, UT 84322, USA.
| | - Ioannis Karagiannidis
- Department of Internal Medicine, Division of Gastroenterology, University of Utah School of Medicine, Salt Lake City, UT84132, USA.
| | - Eliane De Santana Van Vliet
- Department of Internal Medicine, Division of Gastroenterology, University of Utah School of Medicine, Salt Lake City, UT84132, USA.
| | - Ruoxin Yao
- Department of Internal Medicine, Division of Gastroenterology, University of Utah School of Medicine, Salt Lake City, UT84132, USA.
| | - Ellen J Beswick
- Department of Internal Medicine, Division of Gastroenterology, University of Utah School of Medicine, Salt Lake City, UT84132, USA.
| | - Anhong Zhou
- Department of Biological Engineering, Utah State University, Logan, UT 84322, USA.
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Ogrodnik M. Cellular aging beyond cellular senescence: Markers of senescence prior to cell cycle arrest in vitro and in vivo. Aging Cell 2021; 20:e13338. [PMID: 33711211 PMCID: PMC8045927 DOI: 10.1111/acel.13338] [Citation(s) in RCA: 118] [Impact Index Per Article: 39.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 02/09/2021] [Accepted: 02/19/2021] [Indexed: 12/14/2022] Open
Abstract
The field of research on cellular senescence experienced a rapid expansion from being primarily focused on in vitro aspects of aging to the vast territories of animal and clinical research. Cellular senescence is defined by a set of markers, many of which are present and accumulate in a gradual manner prior to senescence induction or are found outside of the context of cellular senescence. These markers are now used to measure the impact of cellular senescence on aging and disease as well as outcomes of anti-senescence interventions, many of which are at the stage of clinical trials. It is thus of primary importance to discuss their specificity as well as their role in the establishment of senescence. Here, the presence and role of senescence markers are described in cells prior to cell cycle arrest, especially in the context of replicative aging and in vivo conditions. Specifically, this review article seeks to describe the process of "cellular aging": the progression of internal changes occurring in primary cells leading to the induction of cellular senescence and culminating in cell death. Phenotypic changes associated with aging prior to senescence induction will be characterized, as well as their effect on the induction of cell senescence and the final fate of cells reviewed. Using published datasets on assessments of senescence markers in vivo, it will be described how disparities between quantifications can be explained by the concept of cellular aging. Finally, throughout the article the applicational value of broadening cellular senescence paradigm will be discussed.
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Affiliation(s)
- Mikolaj Ogrodnik
- Ludwig Boltzmann Research Group Senescence and Healing of Wounds Vienna Austria
- Ludwig Boltzmann Institute for Experimental and Clinical Traumatology in AUVA Research Center Vienna Austria
- Austrian Cluster for Tissue Regeneration Vienna Austria
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6
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González-Gualda E, Baker AG, Fruk L, Muñoz-Espín D. A guide to assessing cellular senescence in vitro and in vivo. FEBS J 2021; 288:56-80. [PMID: 32961620 DOI: 10.1111/febs.15570] [Citation(s) in RCA: 267] [Impact Index Per Article: 89.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 09/09/2020] [Accepted: 09/15/2020] [Indexed: 12/15/2022]
Abstract
Cellular senescence is a physiological mechanism whereby a proliferating cell undergoes a stable cell cycle arrest upon damage or stress and elicits a secretory phenotype. This highly dynamic and regulated cellular state plays beneficial roles in physiology, such as during embryonic development and wound healing, but it can also result in antagonistic effects in age-related pathologies, degenerative disorders, ageing and cancer. In an effort to better identify this complex state, and given that a universal marker has yet to be identified, a general set of hallmarks describing senescence has been established. However, as the senescent programme becomes more defined, further complexities, including phenotype heterogeneity, have emerged. This significantly complicates the recognition and evaluation of cellular senescence, especially within complex tissues and living organisms. To address these challenges, substantial efforts are currently being made towards the discovery of novel and more specific biomarkers, optimized combinatorial strategies and the development of emerging detection techniques. Here, we compile such advances and present a multifactorial guide to identify and assess cellular senescence in cell cultures, tissues and living organisms. The reliable assessment and identification of senescence is not only crucial for better understanding its underlying biology, but also imperative for the development of diagnostic and therapeutic strategies aimed at targeting senescence in the clinic.
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Affiliation(s)
- Estela González-Gualda
- CRUK Cambridge Centre Early Detection Programme, Department of Oncology, Hutchison/MRC Research Centre, University of Cambridge, Cambridge, UK
| | - Andrew G Baker
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK
| | - Ljiljana Fruk
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK
| | - Daniel Muñoz-Espín
- CRUK Cambridge Centre Early Detection Programme, Department of Oncology, Hutchison/MRC Research Centre, University of Cambridge, Cambridge, UK
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7
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Kolesnik DL, Pyaskovskaya ON, Gnatyuk OP, Cherepanov VV, Karakhim SO, Polovii IO, Posudievsky OY, Konoshchuk NV, Strelchuk VV, Nikolenko AS, Dovbeshko GI, Solyanik GI. The effect of 2D tungsten disulfide nanoparticles on Lewis lung carcinoma cells in vitro. RSC Adv 2021; 11:16142-16150. [PMID: 35479162 PMCID: PMC9030634 DOI: 10.1039/d1ra01469b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 04/09/2021] [Indexed: 11/21/2022] Open
Abstract
The unique physicochemical properties of modern two-dimensional (2D) nanomaterials with graphene-like structures make them promising candidates for biology and medicine purposes. In this article, we investigate the influence of the two-dimensional tungsten disulfide (2D WS2) water suspension nanoparticles obtained by an improved mechanochemical method from powdered WS2 on morphological and structural characteristics of Lewis lung carcinoma cells using FT-IR, Raman spectroscopy, and confocal microscopy. The characterization of the 2D WS2 nanoparticles by different physical methods is given also. We have highlighted that 2D WS2 does not exert cytotoxic activity in the case of 1 day incubation with tumor cells. Prolongation of the incubation period up to 2 days has caused a statistically significant (p < 0.05) concentration-dependent decrease of the number of viable cells by more than 30% with the maximum cytotoxic effect at concentrations of 2D WS2 close to 2 μg ml−1. In the Raman spectra of 2D WS2 treated cells the bands centered at 354 cm−1 and 419 cm−1, which are assigned to characteristics and modes of WS2 nanoparticles were observed. The obtained data indicate, that the cytotoxic effect of 2D WS2 on tumor cells in the case of long-term incubation is realized particularly through the ability of 2D WS2 to enter tumor cells and/or accumulate on their surface, which gives a rationale to conduct further studies of their antitumor efficacy in vitro and in vivo when combined with chemotherapeutic drugs. WS2 2D nanoparticles show no cytotoxic and/or cytostatic effect on Lewis lung carcinoma cells after one day incubation. Only after two days incubation we registered cytotoxic effect. Cells incubated with 2D WS2 nanoparticles have luminescence in the blue spectral region.![]()
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Affiliation(s)
- D. L. Kolesnik
- R. E. Kavetsky Institute of Experimental Pathology, Oncology and Radiobiology
- National Academy of Sciences of Ukraine
- Kyiv
- Ukraine
| | - O. N. Pyaskovskaya
- R. E. Kavetsky Institute of Experimental Pathology, Oncology and Radiobiology
- National Academy of Sciences of Ukraine
- Kyiv
- Ukraine
| | - O. P. Gnatyuk
- Department of Physics of Biological Systems
- Institute of Physics of the National Academy of Sciences of Ukraine
- Kyiv 03028
- Ukraine
| | - V. V. Cherepanov
- Department of Physics of Biological Systems
- Institute of Physics of the National Academy of Sciences of Ukraine
- Kyiv 03028
- Ukraine
| | - S. O. Karakhim
- Palladin Institute of Biochemistry of the National Academy of Sciences of Ukraine
- Kyiv 01601
- Ukraine
| | - I. O. Polovii
- Department of Physics of Biological Systems
- Institute of Physics of the National Academy of Sciences of Ukraine
- Kyiv 03028
- Ukraine
| | - O. Yu. Posudievsky
- L. V. Pisarzhevsky Institute of Physical Chemistry of the National Academy of Sciences of Ukraine
- Kyiv 03028
- Ukraine
| | - N. V. Konoshchuk
- L. V. Pisarzhevsky Institute of Physical Chemistry of the National Academy of Sciences of Ukraine
- Kyiv 03028
- Ukraine
| | - V. V. Strelchuk
- V. E. Lashkaryev Institute of Semiconductor Physics of the National Academy of Sciences of Ukraine
- Kyiv 03028
- Ukraine
| | - A. S. Nikolenko
- V. E. Lashkaryev Institute of Semiconductor Physics of the National Academy of Sciences of Ukraine
- Kyiv 03028
- Ukraine
| | - G. I. Dovbeshko
- Department of Physics of Biological Systems
- Institute of Physics of the National Academy of Sciences of Ukraine
- Kyiv 03028
- Ukraine
| | - G. I. Solyanik
- R. E. Kavetsky Institute of Experimental Pathology, Oncology and Radiobiology
- National Academy of Sciences of Ukraine
- Kyiv
- Ukraine
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Alraies A, Canetta E, Waddington RJ, Moseley R, Sloan AJ. Discrimination of Dental Pulp Stem Cell Regenerative Heterogeneity by Single-Cell Raman Spectroscopy. Tissue Eng Part C Methods 2020; 25:489-499. [PMID: 31337281 DOI: 10.1089/ten.tec.2019.0129] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
IMPACT STATEMENT This study is the first to investigate and confirm the effectiveness of single-cell Raman spectroscopy (SCRM), in its ability to discriminate between dental pulp stem cells (DPSCs) with contrasting proliferative and differentiation capabilities. The findings show that SCRM can rapidly and noninvasively distinguish and identify DPSC subpopulations in vitro with superior proliferative and multipotency properties, versus lesser quality DPSCs, thereby overcoming the significant heterogeneity issues surrounding DPSC ex vivo expansion and differentiation capabilities. Such findings support further SCRM assessment for the selective screening/isolation of superior quality DPSCs from whole dental pulp tissues, for more effective in vitro evaluation and therapy development.
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Affiliation(s)
- Amr Alraies
- 1Regenerative Biology Group, School of Dentistry, Cardiff Institute of Tissue Engineering and Repair (CITER), College of Biomedical and Life Sciences, Cardiff University, Cardiff, United Kingdom
| | - Elisabetta Canetta
- 2Faculty of Sports, Health and Applied Science, St. Mary's University, London, United Kingdom
| | - Rachel J Waddington
- 1Regenerative Biology Group, School of Dentistry, Cardiff Institute of Tissue Engineering and Repair (CITER), College of Biomedical and Life Sciences, Cardiff University, Cardiff, United Kingdom
| | - Ryan Moseley
- 1Regenerative Biology Group, School of Dentistry, Cardiff Institute of Tissue Engineering and Repair (CITER), College of Biomedical and Life Sciences, Cardiff University, Cardiff, United Kingdom
| | - Alastair J Sloan
- 1Regenerative Biology Group, School of Dentistry, Cardiff Institute of Tissue Engineering and Repair (CITER), College of Biomedical and Life Sciences, Cardiff University, Cardiff, United Kingdom
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Mehta M, Naffa R, Maidment C, Holmes G, Waterland M. RAMAN AND ATR-FTIR SPECTROSCOPY TOWARDS CLASSIFICATION OF WET BLUE BOVINE LEATHER USING RATIOMETRIC AND CHEMOMETRIC ANALYSIS. JOURNAL OF LEATHER SCIENCE AND ENGINEERING 2020. [DOI: 10.1186/s42825-019-0017-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Abstract
There is a substantial loss of value in bovine leather every year due to a leather quality defect known as “looseness”. Data show that 7% of domestic hide production is affected to some degree, with a loss of $35 m in export returns. This investigation is devoted to gaining a better understanding of tight and loose wet blue leather based on vibrational spectroscopy observations of its structural variations caused by physical and chemical changes that also affect the tensile and tear strength. Several regions from the wet blue leather were selected for analysis. Samples of wet blue bovine leather were collected and studied in the sliced form using Raman spectroscopy (using 532 nm excitation laser) and Attenuated Total Reflectance - Fourier Transform InfraRed (ATR-FTIR) spectroscopy. The purpose of this study was to use ATR-FTIR and Raman spectra to classify distal axilla (DA) and official sampling position (OSP) leather samples and then employ univariate or multivariate analysis or both. For univariate analysis, the 1448 cm− 1 (CH2 deformation) band and the 1669 cm− 1 (Amide I) band were used for evaluating the lipid-to-protein ratio from OSP and DA Raman and IR spectra as indicators of leather quality. Curve-fitting by the sums-of-Gaussians method was used to calculate the peak area ratios of 1448 and 1669 cm− 1 band. The ratio values obtained for DA and OSP are 0.57 ± 0.099, 0.73 ± 0.063 for Raman and 0.40 ± 0.06 and 0.50 ± 0.09 for ATR-FTIR. The results provide significant insight into how these regions can be classified. Further, to identify the spectral changes in the secondary structures of collagen, the Amide I region (1600–1700 cm− 1) was investigated and curve-fitted-area ratios were calculated. The 1648:1681 cm− 1 (non-reducing: reducing collagen types) band area ratios were used for Raman and 1632:1650 cm− 1 (triple helix: α-like helix collagen) for IR. The ratios show a significant difference between the two classes. To support this qualitative analysis, logistic regression was performed on the univariate data to classify the samples quantitatively into one of the two groups. Accuracy for Raman data was 90% and for ATR-FTIR data 100%. Both Raman and ATR-FTIR complemented each other very well in differentiating the two groups. As a comparison, and to reconfirm the classification, multivariate analysis was performed using Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA). The results obtained indicate good classification between the two leather groups based on protein and lipid content. Principal component score 2 (PC2) distinguishes OSP and DA by symmetrically grouping samples at positive and negative extremes. The study demonstrates an excellent model for wider research on vibrational spectroscopy for early and rapid diagnosis of leather quality.
Graphical abstract
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10
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Ogrodnik M, Salmonowicz H, Jurk D, Passos JF. Expansion and Cell-Cycle Arrest: Common Denominators of Cellular Senescence. Trends Biochem Sci 2019; 44:996-1008. [PMID: 31345557 DOI: 10.1016/j.tibs.2019.06.011] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 06/24/2019] [Accepted: 06/26/2019] [Indexed: 12/21/2022]
Abstract
Cellular senescence is a major driver of age-related diseases, and senotherapies are being tested in clinical trials. Despite its popularity, cellular senescence is weakly defined and is frequently referred to as irreversible cell-cycle arrest. In this article we hypothesize that cellular senescence is a phenotype that results from the coordination of two processes: cell expansion and cell-cycle arrest. We provide evidence for the compatibility of the proposed model with recent findings showing senescence in postmitotic tissues, wound healing, obesity, and development. We believe our model also explains why some characteristics of senescence can be found in non-senescent cells. Finally, we propose new avenues for research from our model.
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Affiliation(s)
- Mikolaj Ogrodnik
- Department of Physiology and Biochemical Engineering, Mayo Clinic, Rochester, MN, USA.
| | - Hanna Salmonowicz
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK
| | - Diana Jurk
- Department of Physiology and Biochemical Engineering, Mayo Clinic, Rochester, MN, USA; Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK
| | - João F Passos
- Department of Physiology and Biochemical Engineering, Mayo Clinic, Rochester, MN, USA; Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK.
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