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Saeed A, Bartuzi P, Heegsma J, Dekker D, Kloosterhuis N, de Bruin A, Jonker JW, van de Sluis B, Faber KN. Impaired Hepatic Vitamin A Metabolism in NAFLD Mice Leading to Vitamin A Accumulation in Hepatocytes. Cell Mol Gastroenterol Hepatol 2020; 11:309-325.e3. [PMID: 32698042 PMCID: PMC7768561 DOI: 10.1016/j.jcmgh.2020.07.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 07/16/2020] [Accepted: 07/16/2020] [Indexed: 02/06/2023]
Abstract
BACKGROUND & AIMS Systemic retinol (vitamin A) homeostasis is controlled by the liver, involving close collaboration between hepatocytes and hepatic stellate cells (HSCs). Genetic variants in retinol metabolism (PNPLA3 and HSD17B13) are associated with non-alcoholic fatty liver disease (NAFLD) and disease progression. Still, little mechanistic details are known about hepatic vitamin A metabolism in NAFLD, which may affect carbohydrate and lipid metabolism, inflammation, oxidative stress and the development of fibrosis and cancer, e.g. all risk factors of NAFLD. METHODS Here, we analyzed vitamin A metabolism in 2 mouse models of NAFLD; mice fed a high-fat, high-cholesterol (HFC) diet and Leptinob mutant (ob/ob) mice. RESULTS Hepatic retinol and retinol binding protein 4 (RBP4) levels were significantly reduced in both mouse models of NAFLD. In contrast, hepatic retinyl palmitate levels (the vitamin A storage form) were significantly elevated in these mice. Transcriptome analysis revealed a hyperdynamic state of hepatic vitamin A metabolism, with enhanced retinol storage and metabolism (upregulated Lrat, Dgat1, Pnpla3, Raldh's and RAR/RXR-target genes) in fatty livers, in conjunction with induced hepatic inflammation (upregulated Cd68, Tnfα, Nos2, Il1β, Il-6) and fibrosis (upregulated Col1a1, Acta2, Tgfβ, Timp1). Autofluorescence analyses revealed prominent vitamin A accumulation in hepatocytes rather than HSC in HFC-fed mice. Palmitic acid exposure increased Lrat mRNA levels in primary rat hepatocytes and promoted retinyl palmitate accumulation when co-treated with retinol, which was not detected for similarly-treated primary rat HSCs. CONCLUSION NAFLD leads to cell type-specific rearrangements in retinol metabolism leading to vitamin A accumulation in hepatocytes. This may promote disease progression and/or affect therapeutic approaches targeting nuclear receptors.
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Affiliation(s)
- Ali Saeed
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands; Institute of Molecular Biology and Biotechnology, Bahauddin Zakariya University, Multan, Pakistan.
| | - Paulina Bartuzi
- Section of Molecular Genetics, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Janette Heegsma
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands; Laboratory Medicine, Department of Pediatrics, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Daphne Dekker
- Section of Molecular Genetics, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Niels Kloosterhuis
- Section of Molecular Genetics, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Alain de Bruin
- Section of Molecular Genetics, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands; Dutch Molecular Pathology Center, Department of Pathobiology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands
| | - Johan W Jonker
- Section of Molecular Metabolism and Nutrition, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Bart van de Sluis
- Section of Molecular Genetics, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Klaas Nico Faber
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands; Laboratory Medicine, Department of Pediatrics, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
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Berardo C, Siciliano V, Di Pasqua LG, Richelmi P, Vairetti M, Ferrigno A. Comparison between Lipofectamine RNAiMAX and GenMute transfection agents in two cellular models of human hepatoma. Eur J Histochem 2019; 63. [PMID: 31455073 PMCID: PMC6712361 DOI: 10.4081/ejh.2019.3048] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 07/18/2019] [Indexed: 12/27/2022] Open
Abstract
RNA interference is a powerful approach to understand gene function both for therapeutic and experimental purposes. Since the lack of knowledge in the gene silencing of various hepatic cell lines, this work was aimed to compare two transfection agents, the liposome-based Lipofectamine™ RNAiMAX and the HepG2-specific, polymer-based GenMute™, in two cellular models of human hepatoma, HepG2 and Huh7.5. In the first part, we assessed transfection efficiency of a fluorescent Cy3-labeled negative control siRNA by cell imaging analysis; we found that cells treated with GenMute present a higher uptake of the fluorescent negative control siRNA when compared to Lipofectamine RNAiMAX-trasfected cells, both in HepG2 and in Huh7.5 cells. In the second part, we evaluated GAPDH silencing with the two transfection reagents by RT-PCR finding similar GAPDH mRNA expression after each transfection treatment. Finally, we measured cell viability by the MTT assay, observing that cells transfected with GenMute have a higher viability with respect to Lipofectamine RNAiMAXadministered cells. These results suggest that GenMute reagent might be considered the most suitable transfection agent for hepatic gene silencing.
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Affiliation(s)
- Clarissa Berardo
- Department of Internal Medicine and Therapeutics, University of Pavia.
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Croce AC, Ferrigno A, Bottiroli G, Vairetti M. Autofluorescence-based optical biopsy: An effective diagnostic tool in hepatology. Liver Int 2018; 38:1160-1174. [PMID: 29624848 DOI: 10.1111/liv.13753] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 03/27/2018] [Indexed: 12/15/2022]
Abstract
Autofluorescence emission of liver tissue depends on the presence of endogenous biomolecules able to fluoresce under suitable light excitation. Overall autofluorescence emission contains much information of diagnostic value because it is the sum of individual autofluorescence contributions from fluorophores involved in metabolism, for example, NAD(P)H, flavins, lipofuscins, retinoids, porphyrins, bilirubin and lipids, or in structural architecture, for example, fibrous proteins, in close relationship with normal, altered or diseased conditions of the liver. Since the 1950s, hepatocytes and liver have been historical models to study NAD(P)H and flavins as in situ, real-time autofluorescence biomarkers of energy metabolism and redox state. Later investigations designed to monitor organ responses to ischaemia/reperfusion were able to predict the risk of dysfunction in surgery and transplantation or support the development of procedures to ameliorate the liver outcome. Subsequently, fluorescent fatty acids, lipofuscin-like lipopigments and collagen were characterized as optical biomarkers of liver steatosis, oxidative stress damage, fibrosis and disease progression. Currently, serum AF is being investigated to improve non-invasive optical diagnosis of liver disease. Validation of endogenous fluorophores and in situ discrimination of cancerous from non-cancerous tissue belong to the few studies on liver in human subjects. These reports along with other optical techniques and the huge work performed on animal models suggest many optically based applications in hepatology. Optical diagnosis is currently offering beneficial outcomes in clinical fields ranging from the respiratory and gastrointestinal tracts, to dermatology and ophthalmology. Accordingly, this review aims to promote an effective bench to bedside transfer in hepatology.
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Affiliation(s)
- Anna Cleta Croce
- Institute of Molecular Genetics, Italian National Research Council (CNR), Pavia, Italy.,Department of Biology & Biotechnology, University of Pavia, Pavia, Italy
| | - Andrea Ferrigno
- Internal Medicine and Therapy Department, University of Pavia, Pavia, Italy
| | - Giovanni Bottiroli
- Institute of Molecular Genetics, Italian National Research Council (CNR), Pavia, Italy.,Department of Biology & Biotechnology, University of Pavia, Pavia, Italy
| | - Mariapia Vairetti
- Internal Medicine and Therapy Department, University of Pavia, Pavia, Italy
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Fabila-Bustos DA, Arroyo-Camarena ÚD, López-Vancell MD, Durán-Padilla MA, Azuceno-García I, Stolik-Isakina S, Valor-Reed A, Ibarra-Coronado E, Hernández-Quintanar LF, Escobedo G, de la Rosa-Vázquez JM. Fluorescence Spectroscopy as a Tool for the Assessment of Liver Samples with Several Stages of Fibrosis. Photomed Laser Surg 2018; 36:151-161. [DOI: 10.1089/pho.2017.4301] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Affiliation(s)
- Diego A. Fabila-Bustos
- Laboratorio de Espectroscopía, UPIIH, Instituto Politécnico Nacional, Ciudad del Conocimiento y la Cultura, San Agustín Tlaxiaca, Hidalgo, México
- Laboratorio de Biofotónica, ESIME ZAC, Instituto Politécnico Nacional, Ciudad de México, México
| | - Úrsula D. Arroyo-Camarena
- Unidad de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Hospital General de México “Dr. Eduardo Liceaga,” Ciudad de México, México
| | - María D. López-Vancell
- Servicio de Patología, Hospital General de México “Dr. Eduardo Liceaga,” Ciudad de México, México
| | - Marco A. Durán-Padilla
- Servicio de Patología, Hospital General de México “Dr. Eduardo Liceaga,” Ciudad de México, México
| | - Itzel Azuceno-García
- Unidad de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Hospital General de México “Dr. Eduardo Liceaga,” Ciudad de México, México
| | - Suren Stolik-Isakina
- Laboratorio de Biofotónica, ESIME ZAC, Instituto Politécnico Nacional, Ciudad de México, México
| | - Alma Valor-Reed
- Laboratorio de Biofotónica, ESIME ZAC, Instituto Politécnico Nacional, Ciudad de México, México
| | - Elizabeth Ibarra-Coronado
- Departamento de Inmunología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, Ciudad de México, México
| | - Luis F. Hernández-Quintanar
- Laboratorio de Biofotónica, ESIME ZAC, Instituto Politécnico Nacional, Ciudad de México, México
- Universidad Tecnológica de México-UNITEC MEXICO—Campus Sur, Ciudad de México, México
| | - Galileo Escobedo
- Unidad de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Hospital General de México “Dr. Eduardo Liceaga,” Ciudad de México, México
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Ranjit S, Dvornikov A, Dobrinskikh E, Wang X, Luo Y, Levi M, Gratton E. Measuring the effect of a Western diet on liver tissue architecture by FLIM autofluorescence and harmonic generation microscopy. BIOMEDICAL OPTICS EXPRESS 2017; 8:3143-3154. [PMID: 28717559 PMCID: PMC5508820 DOI: 10.1364/boe.8.003143] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 05/13/2017] [Accepted: 05/19/2017] [Indexed: 05/12/2023]
Abstract
The phasor approach to auto-fluorescence lifetime imaging was used to identify and characterize a long lifetime species (LLS) (~7.8 ns) in livers of mice fed with a Western diet. The size of the areas containing this LLS species depends on the type of diet and the size distribution shows Western diet has much larger LLS sizes. Combination of third harmonic generation images with FLIM identified the LLS species with fat droplets and the droplet size distribution was estimated. Second harmonic generation microscopy combined with phasor FLIM shows that there is an increase in fibrosis with a Western diet. A new decomposition in three components of the phasor plot shows that a Western diet is correlated with a higher fraction of free NADH, signifying more reducing condition and more glycolytic condition. Multiparametric analysis of phasor distribution shows that from the distribution of phasor points, a Western diet fed versus a low fat diet fed samples of mice livers can be separated. The phasor approach for the analysis of FLIM images of autofluorescence in liver specimens can result in discovery of new fluorescent species and then these new fluorescent species can help assess tissue architecture. Finally integrating FLIM and second and third harmonic analysis provides a measure of the advancement of fibrosis as an effect of diet.
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Affiliation(s)
- Suman Ranjit
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California, Irvine, CA, USA
| | - Alexander Dvornikov
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California, Irvine, CA, USA
| | - Evgenia Dobrinskikh
- Departments of Medicine, University of Colorado-Anschutz Medical Campus, Aurora, Colorado, USA
| | - Xiaoxin Wang
- Departments of Medicine, University of Colorado-Anschutz Medical Campus, Aurora, Colorado, USA
| | - Yuhuan Luo
- Departments of Medicine, University of Colorado-Anschutz Medical Campus, Aurora, Colorado, USA
| | - Moshe Levi
- Departments of Medicine, University of Colorado-Anschutz Medical Campus, Aurora, Colorado, USA
| | - Enrico Gratton
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California, Irvine, CA, USA
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Croce AC, Bottiroli G. Lipids: Evergreen autofluorescent biomarkers for the liver functional profiling. Eur J Histochem 2017; 61:2808. [PMID: 28735528 PMCID: PMC5460376 DOI: 10.4081/ejh.2017.2808] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 05/25/2017] [Accepted: 05/25/2017] [Indexed: 02/07/2023] Open
Abstract
Depending on their chemical nature, lipids can be classified in two main categories: hydrophilic, greatly contributing to membrane composition and subcellular organelle compartmentalization, and hydrophobic, mostly triglycerides, greatly enrolled in the storage and production of energy. In both cases, some lipid molecules can be involved as signaling agents in the regulation of metabolism and protective or damaging pathways in responses to harmful stimuli. These events could affect in particular the liver, because of its central role in the maintenance of lipid homeostasis. Lipids have been demonstrated to fluoresce, contributing to the overall emission signal of the liver tissue along with other endogenous fluorophores, relatable to energy metabolism and oxidative events. The mere estimation of the fluorescing lipid fraction in parallel with the other endogenous fluorophores, and with the common biochemical and histochemical biomarkers of tissue injury has been exploited to investigate the liver morpho- functional conditions in experimental hepatology. More interestingly, the fluorescing lipid fraction is greatly relatable to free fatty acids such as arachidonic, linoleic and linolenic acid, which are deserving increasing attention as precursors of products involved in several and complex signaling pathways. On these bases, the ability of autofluorescence to detect directly arachidonic acid and its balance with other unsaturated fatty acids may be exploited in the diagnosis and follow-up of fatty livers, helping to improve the personalization of the metabolic/ lipidomic profiling. This could also contribute to elucidate the role of the injuring factors in the choice of suitable donors, and in the set-up of preservation procedures in liver transplantation.
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Ferrigno A, Di Pasqua LG, Berardo C, Siciliano V, Richelmi P, Vairetti M. Oxygen tension-independent protection against hypoxic cell killing in rat liver by low sodium. Eur J Histochem 2017; 61:2798. [PMID: 28735525 PMCID: PMC5452633 DOI: 10.4081/ejh.2017.2798] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 05/12/2017] [Accepted: 05/13/2017] [Indexed: 12/02/2022] Open
Abstract
The role of Na+ in hypoxic injury was evaluated by a time-course analysis of damage in isolated livers perfused with N2-saturated buffer containing standard (143 mM) or low (25 mM) Na+ levels. Trypan blue uptake was used to detect non-viable cells. Under hypoxia with standard-Na+, trypan blue uptake began at the border between pericentral areas and periportal regions and increased in the latter zone; using a low-Na+ buffer, no trypan blue zonation occurred but a homogenous distribution of dye was found associated with sinusoidal endothelial cell (SEC) staining. A decrease in hyaluronic acid (HA) uptake, index of SEC damage, was observed using a low-Na+ buffer. A time dependent injury was confirmed by an increase in LDH and TBARS levels with standard-Na+ buffer. Using low-Na+ buffer, SEC susceptibility appears elevated under hypoxia and hepatocytes was protected, in an oxygen independent manner.
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Affiliation(s)
- Andrea Ferrigno
- University of Pavia, Department of Internal Medicine and Therapeutics.
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Croce AC, Bottiroli G. Autofluorescence Spectroscopy for Monitoring Metabolism in Animal Cells and Tissues. Methods Mol Biol 2017; 1560:15-43. [PMID: 28155143 DOI: 10.1007/978-1-4939-6788-9_2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Excitation of biological substrates with light at a suitable wavelength can give rise to a light emission in the ultraviolet (UV)-visible, near-infrared (IR) spectral range, called autofluorescence (AF). This is a widespread phenomenon, ascribable to the general presence of biomolecules acting as endogenous fluorophores (EFs) in the organisms of the whole life kingdom. In cytochemistry and histochemistry, AF is often an unwanted signal enhancing the background and affecting in particular the detection of low signals or rare positive labeling spots of exogenous markers. Conversely, AF is increasingly considered as a powerful diagnostic tool because of its role as an intrinsic biomarker directly dependent on the nature, amount, and microenvironment of the EFs, in a strict relationship with metabolic processes and structural organization of cells and tissues. As a consequence, AF carries multiple information that can be decrypted by a proper analysis of the overall emission signal, allowing the characterization and monitoring of cell metabolism in situ, in real time and in the absence of perturbation from exogenous markers. In the animal kingdom, AF studies at the cellular level take advantage of the essential presence of NAD(P)H and flavins, primarily acting as coenzymes at multiple steps of common metabolic pathways for energy production, reductive biosynthesis and antioxidant defense. Additional EFs such as vitamin A, porphyrins, lipofuscins, proteins, and neuromediators can be detected in different kinds of cells and bulk tissues, and can be exploited as photophysical biomarkers of specific normal or altered morphofunctional properties, from the retinoid storage in the liver to aging processes, metabolic disorders or cell transformation processes. The AF phenomenon involves all living system, and literature reports numerous investigations and diagnostic applications of AF, taking advantage of continuously developing self-assembled or commercial instrumentation and measuring procedures, making almost impossible to provide their comprehensive description. Therefore a brief summary of the history of AF observations and of the development of measuring systems is provided, along with a description of the most common EFs and their metabolic significance. From our direct experience, examples of AF imaging and microspectrofluorometric procedures performed under a single excitation in the near-UV range for cell and tissue metabolism studies are then reported.
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Affiliation(s)
- Anna C Croce
- Institute of Molecular Genetics (IGM) - CNR, via Abbiategrasso, 207, 27100, Pavia, Italy.
| | - Giovanni Bottiroli
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Pavia, Italy
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Croce AC, Ferrigno A, Di Pasqua LG, Berardo C, Piccolini VM, Bertone V, Bottiroli G, Vairetti M. Autofluorescence discrimination of metabolic fingerprint in nutritional and genetic fatty liver models. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2016; 164:13-20. [DOI: 10.1016/j.jphotobiol.2016.09.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 09/09/2016] [Accepted: 09/10/2016] [Indexed: 12/21/2022]
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Croce AC, Bottiroli G. Autofluorescence spectroscopy and imaging: a tool for biomedical research and diagnosis. Eur J Histochem 2014; 58:2461. [PMID: 25578980 PMCID: PMC4289852 DOI: 10.4081/ejh.2014.2461] [Citation(s) in RCA: 303] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 12/04/2014] [Indexed: 12/18/2022] Open
Abstract
Native fluorescence, or autofluorescence (AF), consists in the emission of light in the UV-visible, near-IR spectral range when biological substrates are excited with light at suitable wavelength. This is a well-known phenomenon, and the strict relationship of many endogenous fluorophores with morphofunctional properties of the living systems, influencing their AF emission features, offers an extremely powerful resource for directly monitoring the biological substrate condition. Starting from the last century, the technological progresses in microscopy and spectrofluorometry were convoying attention of the scientific community to this phenomenon. In the future, the interest in the autofluorescence will certainly continue. Current instrumentation and analytical procedures will likely be overcome by the unceasing progress in new devices for AF detection and data interpretation, while a progress is expected in the search and characterization of endogenous fluorophores and their roles as intrinsic biomarkers.
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Affiliation(s)
- A C Croce
- Institute of Molecular Genetics of the National Research Council, University of Pavia.
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Croce AC, Ferrigno A, Santin G, Vairetti M, Bottiroli G. Bilirubin: an autofluorescence bile biomarker for liver functionality monitoring. JOURNAL OF BIOPHOTONICS 2014; 7:810-817. [PMID: 23616471 DOI: 10.1002/jbio.201300039] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 03/27/2013] [Accepted: 04/04/2013] [Indexed: 06/02/2023]
Abstract
Excitation at 366-465 nm of bilirubin in aqueous solution with solubilizing agents results in emission spectra composed by two main bands. The variation of their relative contributions as shown by changes in the spectral shape are consistent with the bilirubin bichromophore nature. This latter accounts for an exciton-coupling phenomenon, intramolecular interchromophore energy transfer efficiency being affected by microenvironment. Excitation at 366 nm, despite the poor absorption of bilirubin, gives rise to appreciable emission signals from both pure compounds and bile - collected from functionally altered rat livers - favouring the spectral shape response to environment and molecular conformation changes. As compared to the merely bile flow estimation, real-time detection of fluorescence, revealing composition variations, improves near-UV optical-biopsy diagnostic potential in hepatology.
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Affiliation(s)
- Anna C Croce
- Histochemistry and Cytometry Unit, IGM-CNR, Biology and Biotechnology Department, University of Pavia, Via Ferrata 9, Palazzo Botta 2, 27100, Italy.
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Integrated autofluorescence characterization of a modified-diet liver model with accumulation of lipids and oxidative stress. BIOMED RESEARCH INTERNATIONAL 2014; 2014:803491. [PMID: 25006587 PMCID: PMC4070497 DOI: 10.1155/2014/803491] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Revised: 05/09/2014] [Accepted: 05/09/2014] [Indexed: 01/16/2023]
Abstract
Oxidative stress in fatty livers is mainly generated by impaired mitochondrial β-oxidation, inducing tissue damages and disease progression. Under suitable excitation, light liver endogenous fluorophores can give rise to autofluorescence (AF) emission, the properties of which depend on the organ morphofunctional state. In this work, we characterized the AF properties of a rat liver model of lipid accumulation and oxidative stress, induced by a 1–9-week hypercaloric methionine-choline deficient (MCD) diet administration. The AF analysis (excitation at 366 nm) was performed in vivo, via fiber optic probe, or ex vivo. The contribution of endogenous fluorophores involved in redox reactions and in tissue organization was estimated through spectral curve fitting analysis, and AF results were validated by means of different histochemical and biochemical assays (lipids, collagen, vitamin A, ROS, peroxidised proteins, and lipid peroxidation -TBARS-, GSH, and ATP). In comparison with the control, AF spectra changes found already at 1 week of MCD diet reflect alterations both in tissue composition and organization (proteins, lipopigments, and vitamin A) and in oxidoreductive pathway engagement (NAD(P)H, flavins), with a subsequent attempt to recover redox homeostasis. These data confirm the AF analysis potential to provide a comprehensive diagnostic information on negative effects of oxidative metabolism alteration.
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Sauvage VR, Levene AP, Nguyen HT, Wood TC, Kudo H, Concas D, Thomas HC, Thursz MR, Goldin RD, Anstee QM, Elson DS. Multi-excitation fluorescence spectroscopy for analysis of non-alcoholic fatty liver disease. Lasers Surg Med 2012; 43:392-400. [PMID: 21674544 DOI: 10.1002/lsm.21064] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND AND OBJECTIVES The increasing incidence of non-alcoholic fatty liver diseases (NAFLD) and the consequent progression to cirrhosis is expected to become a major cause of liver transplantation. This will exacerbate the organ donor shortage and mean that 'marginal' fatty liver grafts are more frequently used. Autofluorescence spectroscopy is a fast, objective, and non-destructive method to detect change in the endogenous fluorophores distribution and could prove to be a valuable tool for NAFLD diagnosis and transplant graft assessment. MATERIALS AND METHODS A system was constructed consisting of a fibre probe with two laser diodes that provided excitation light at 375 and 405 nm, and an imaging spectrograph system. This was used to distinguish fluorescence spectra acquired from the harvested livers from mice with NAFLD of differing severity (healthy, mild steatotic and steatohepatitic). The fluorescence data were entered into a sparse multiclass probabilistic algorithm for disease classification. Histopathology, thiobarbituric acid reactive substances (TBARS) and alanine transaminase (ALT) assays were conducted in addition to the fluorescence measurements RESULTS TBARS and ALT assays enabled differentiation of the steatohepatitic group from the mild steatosis and control groups (P ≤ 0.028) but failed to separate the mild steatotic group from the control group. The three groups were all clearly differentiated from each other using fluorescence spectroscopy, and classification accuracy was found to be 95%. CONCLUSION Fluorescence spectroscopy appears to be a promising approach for the analysis of diseased liver tissue.
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Affiliation(s)
- Vincent R Sauvage
- Department of Surgery and Cancer, Imperial College London, London SW72AZ, United Kingdom
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Boreham A, Kim TY, Spahn V, Stein C, Mundhenk L, Gruber AD, Haag R, Welker P, Licha K, Alexiev U. Exploiting Fluorescence Lifetime Plasticity in FLIM: Target Molecule Localization in Cells and Tissues. ACS Med Chem Lett 2011; 2:724-8. [PMID: 24900259 DOI: 10.1021/ml200092m] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Accepted: 08/09/2011] [Indexed: 11/30/2022] Open
Abstract
The mechanisms of drug-receptor interactions and the controlled delivery of drugs via biodegradable and biocompatible nanoparticulate carriers are active research fields in nanomedicine. Many clinically used drugs target G-protein coupled receptors (GPCRs) due to the fact that signaling via GPCRs is crucial in physiological and pathological processes and thus central for the function of biological systems. In this letter, a fast and reliable ratiometric fluorescence lifetime imaging microscopy (rmFLIM) approach is described to analyze the distribution of protein-ligand complexes in the cellular context. Binding of the fluorescently labeled antagonist naloxone to the G-protein coupled μ-opioid receptor is used as an example. To show the broad applicability of the rmFLIM method, we extended this approach to investigate the distribution of polymer-based nanocarriers in histological liver sections.
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Affiliation(s)
- A. Boreham
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany
| | - T.-Y. Kim
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany
| | - V. Spahn
- Klinik für Anästhesiologie, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, 12203 Berlin, Germany
| | - C. Stein
- Klinik für Anästhesiologie, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, 12203 Berlin, Germany
| | - L. Mundhenk
- Institut für Tierpathologie, Freie Universität Berlin, Robert-von-Ostertag-Strasse 15, 14163 Berlin, Germany
| | - A. D. Gruber
- Institut für Tierpathologie, Freie Universität Berlin, Robert-von-Ostertag-Strasse 15, 14163 Berlin, Germany
| | - R. Haag
- Institut für Chemie und Biochemie, Freie Universität Berlin, Takustrasse 3, 14195 Berlin, Germany
| | - P. Welker
- mivenion GmbH, Robert-Koch-Platz 4, 10115 Berlin, Germany
| | - K. Licha
- mivenion GmbH, Robert-Koch-Platz 4, 10115 Berlin, Germany
| | - U. Alexiev
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany
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Croce AC, De Simone U, Freitas I, Boncompagni E, Neri D, Cillo U, Bottiroli G. Human liver autofluorescence: an intrinsic tissue parameter discriminating normal and diseased conditions. Lasers Surg Med 2010; 42:371-8. [PMID: 20583250 DOI: 10.1002/lsm.20923] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
BACKGROUND AND OBJECTIVE Autofluorescence (AF) emission is an intrinsic parameter that can provide real-time information on morpho-functional properties of biological tissue, being strictly related with their biochemical composition and structural organization. The diagnostic potentials of AF-based techniques have been investigated on normal, fibrotic, and steatotic liver tissues, in reference to histological features as evidenced by specific histochemical stainings. MATERIALS AND METHODS AF emission under excitation at 366 nm has been examined on cryostatic tissue sections obtained from biopsies collected during surgical operation, by means of fluorescence imaging and microspectrofluorometric techniques. RESULTS NAD(P)H, collagen, and vitamin A were found to be the endogenous fluorophores characterizing normal, fibrotic, and steatotic liver tissue AF, respectively. The differences of their photo-physical properties, in terms of emission amplitude, spectral shape, and response to irradiation, give rise to modifications of overall AF signal collected from tissues that allow the liver conditions to be distinguished. CONCLUSION The study provides a valid premise for a development of AF-based optical biopsy techniques for a real-time discrimination of liver anatomo-pathological patterns.
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Affiliation(s)
- Anna C Croce
- Histochemistry and Cytometry Section, IGM-CNR, Pavia 27100, Italy
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