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Carretta A, Moscardini A, Signore G, Debellis D, Catalano F, Marotta R, Palmieri V, Tedeschi G, Scipioni L, Pozzi D, Caracciolo G, Beltram F, Cardarelli F. The supramolecular processing of liposomal doxorubicin hinders its therapeutic efficacy in cells. MOLECULAR THERAPY. ONCOLOGY 2024; 32:200836. [PMID: 39050990 PMCID: PMC11268116 DOI: 10.1016/j.omton.2024.200836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2024] [Revised: 06/06/2024] [Accepted: 06/13/2024] [Indexed: 07/27/2024]
Abstract
The successful trajectory of liposome-encapsulated doxorubicin (e.g., Doxil, which has been approved by the U.S. Food and Drug Administration) as an anticancer nanodrug in clinical applications is contradicted by in vitro cell viability data that highlight its reduced efficacy in promoting cell death compared with non-encapsulated doxorubicin. No reports to date have provided a mechanistic explanation for this apparently discordant evidence. Taking advantage of doxorubicin intrinsic fluorescence and time-resolved optical microscopy, we analyze the uptake and intracellular processing of liposome-encapsulated doxorubicin (L-DOX) in several in vitro cellular models. Cell entry of L-DOX was found to lead to a rapid (seconds to minutes), energy- and temperature-independent release of crystallized doxorubicin nanorods into the cell cytoplasm, which then disassemble into a pool of fibril-shaped derivatives capable of crossing the cellular membrane while simultaneously releasing active drug monomers. Thus, a steady state is rapidly established in which the continuous supply of crystal nanorods from incoming liposomes is counteracted by a concentration-guided efflux in the extracellular medium of fibril-shaped derivatives and active drug monomers. These results demonstrate that liposome-mediated delivery is constitutively less efficient than isolated drug in establishing favorable conditions for drug retention in the cell. In addition to explaining previous contradictory evidence, present results impose careful rethinking of the synthetic identity of encapsulated anticancer drugs.
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Affiliation(s)
- Annalisa Carretta
- Scuola Normale Superiore, Laboratorio NEST, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - Aldo Moscardini
- Scuola Normale Superiore, Laboratorio NEST, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - Giovanni Signore
- Biochemistry Unit, Department of Biology, University of Pisa, via San Zeno 51, 56123 Pisa, Italy
- Institute of Clinical Physiology, National Research Council, 56124 Pisa, Italy
| | - Doriana Debellis
- Electron Microscopy Facility, Istituto Italiano di Tecnologia (IIT), Via Morego 30, 16163 Genova, Italy
| | - Federico Catalano
- Electron Microscopy Facility, Istituto Italiano di Tecnologia (IIT), Via Morego 30, 16163 Genova, Italy
| | - Roberto Marotta
- Electron Microscopy Facility, Istituto Italiano di Tecnologia (IIT), Via Morego 30, 16163 Genova, Italy
| | - Valentina Palmieri
- Istituto dei Sistemi Complessi ISC CNR, Via dei Taurini 19, 00185 Rome, Italy
| | - Giulia Tedeschi
- Laboratory for Fluorescence Dynamics, Biomedical Engineering Department, University of California, Irvine, Irvine, CA, USA
| | - Lorenzo Scipioni
- Laboratory for Fluorescence Dynamics, Biomedical Engineering Department, University of California, Irvine, Irvine, CA, USA
| | - Daniela Pozzi
- Department of Molecular Medicine, Sapienza University of Rome, Rome, Italy
| | - Giulio Caracciolo
- Department of Molecular Medicine, Sapienza University of Rome, Rome, Italy
| | - Fabio Beltram
- Scuola Normale Superiore, Laboratorio NEST, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - Francesco Cardarelli
- Scuola Normale Superiore, Laboratorio NEST, Piazza San Silvestro 12, 56127 Pisa, Italy
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2
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Todaro B, Pesce L, Cardarelli F, Luin S. Pioglitazone Phases and Metabolic Effects in Nanoparticle-Treated Cells Analyzed via Rapid Visualization of FLIM Images. Molecules 2024; 29:2137. [PMID: 38731628 PMCID: PMC11085555 DOI: 10.3390/molecules29092137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2024] [Revised: 04/30/2024] [Accepted: 05/01/2024] [Indexed: 05/13/2024] Open
Abstract
Fluorescence lifetime imaging microscopy (FLIM) has proven to be a useful method for analyzing various aspects of material science and biology, like the supramolecular organization of (slightly) fluorescent compounds or the metabolic activity in non-labeled cells; in particular, FLIM phasor analysis (phasor-FLIM) has the potential for an intuitive representation of complex fluorescence decays and therefore of the analyzed properties. Here we present and make available tools to fully exploit this potential, in particular by coding via hue, saturation, and intensity the phasor positions and their weights both in the phasor plot and in the microscope image. We apply these tools to analyze FLIM data acquired via two-photon microscopy to visualize: (i) different phases of the drug pioglitazone (PGZ) in solutions and/or crystals, (ii) the position in the phasor plot of non-labelled poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs), and (iii) the effect of PGZ or PGZ-containing NPs on the metabolism of insulinoma (INS-1 E) model cells. PGZ is recognized for its efficacy in addressing insulin resistance and hyperglycemia in type 2 diabetes mellitus, and polymeric nanoparticles offer versatile platforms for drug delivery due to their biocompatibility and controlled release kinetics. This study lays the foundation for a better understanding via phasor-FLIM of the organization and effects of drugs, in particular, PGZ, within NPs, aiming at better control of encapsulation and pharmacokinetics, and potentially at novel anti-diabetics theragnostic nanotools.
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Affiliation(s)
- Biagio Todaro
- NEST Laboratory, Scuola Normale Superiore, Piazza San Silvestro 12, 56127 Pisa, Italy; (L.P.); (F.C.)
| | - Luca Pesce
- NEST Laboratory, Scuola Normale Superiore, Piazza San Silvestro 12, 56127 Pisa, Italy; (L.P.); (F.C.)
| | - Francesco Cardarelli
- NEST Laboratory, Scuola Normale Superiore, Piazza San Silvestro 12, 56127 Pisa, Italy; (L.P.); (F.C.)
| | - Stefano Luin
- NEST Laboratory, Scuola Normale Superiore, Piazza San Silvestro 12, 56127 Pisa, Italy; (L.P.); (F.C.)
- NEST Laboratory, Istituto Nanoscienze-CNR, Piazza San Silvestro 12, 56127 Pisa, Italy
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3
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Saddam Hussain M, Khetan R, Clulow AJ, Ganesan R, MacMillan A, Robinson N, Ahmed-Cox A, Krasowska M, Albrecht H, Blencowe A. Teaching an Old Dog New Tricks: A Global Approach to Enhancing the Cytotoxicity of Drug-Loaded, Non-responsive Micelles Using Oligoelectrolytes. ACS APPLIED MATERIALS & INTERFACES 2024; 16:9736-9748. [PMID: 38349780 DOI: 10.1021/acsami.3c16551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/15/2024]
Abstract
Polymeric micelles have been extensively studied as vectors for the delivery of hydrophobic drugs for the treatment of cancers and other diseases. Despite intensive research, few formulations provide significant benefits, and even fewer have been clinically approved. While many traditional non-responsive micelles have excellent safety profiles, they lack the ability to respond to the intracellular environment and release their cargo in a spatiotemporally defined manner to effectively deliver large doses of cytotoxic drugs into the cytosol of cells that overwhelm efflux pumps. As a novel and adaptable strategy, we hypothesized that well-established non-responsive polymeric micelles could be augmented with a pH-trigger via the co-encapsulation of cytocompatible oligoelectrolytes, which would allow rapid cargo release in the endosome, leading to increased cytotoxicity. Herein, we demonstrate how this strategy can be applied to render non-responsive micelles pH-responsive, resulting in abrupt cargo release at specific and tunable pH values compatible with endosomal delivery, which significantly increased their cytotoxicity up to 3-fold in an ovarian adenocarcinoma (SKOV-3) cell line compared to non-responsive micelles. In comparison, the oligoelectrolyte-loaded micelles were significantly less toxic to healthy 3T3 fibroblasts, indicating a selective cargo release in cancer cell lines. Oligoelectrolytes can be co-encapsulated in the micelles along with drugs at high encapsulation efficiency percentages, which are both ejected from the micelle core upon oligoelectrolyte ionization. Mechanistically, the increase in cytotoxicity appears to also result from the accelerated endosomal escape of the cargo caused by disruption of the endosomal membrane by the simultaneous release of the oligoelectrolytes from the micelles. Furthermore, we show how this approach is broadly applicable to non-responsive micelles regardless of their composition and various classes of hydrophobic chemotherapeutics. The preliminary studies presented here reveal the versatility and wide scope of oligoelectrolyte-mediated, pH-triggered drug release as a compelling and powerful strategy to enhance the cytotoxicity of non-responsive polymeric micelles.
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Affiliation(s)
- Md Saddam Hussain
- Applied Chemistry and Translational Biomaterials (ACTB) Group, Centre for Pharmaceutical Innovation (CPI), UniSA CHS, University of South Australia, Adelaide, South Australia 5000, Australia
| | - Riya Khetan
- Centre for Pharmaceutical Innovation (CPI), UniSA CHS, University of South Australia, Adelaide, South Australia 5000, Australia
| | - Andrew J Clulow
- Australian Synchrotron, Australian Nuclear Science and Technology Organisation (ANSTO), 800 Blackburn Road, Clayton, Victoria 3168, Australia
- Drug Delivery, Disposition & Dynamics, Monash Institute of Pharmaceutical Sciences, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Raja Ganesan
- Centre for Cancer Biology, UniSA CHS, University of South Australia, Adelaide, South Australia 5000, Australia
| | - Alexander MacMillan
- Katharina Gaus Light Microscopy Facility, Mark Wainwright Analytical Centre, University of New South Wales, Sydney, New South Wales 2033, Australia
| | - Nirmal Robinson
- Centre for Cancer Biology, UniSA CHS, University of South Australia, Adelaide, South Australia 5000, Australia
| | - Aria Ahmed-Cox
- Katharina Gaus Light Microscopy Facility, Mark Wainwright Analytical Centre, University of New South Wales, Sydney, New South Wales 2033, Australia
- Children's Cancer Institute, Lowy Cancer Research Centre, University of New South Wales, Sydney, New South Wales 2750, Australia
- Australian Centre for Nanomedicine, Faculty of Engineering, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Marta Krasowska
- Surface Interactions and Soft Matter (SISM) Group, Future Industries Institute, UniSA STEM, University of South Australia, Mawson Lakes, South Australia 5095, Australia
| | - Hugo Albrecht
- Centre for Pharmaceutical Innovation (CPI), UniSA CHS, University of South Australia, Adelaide, South Australia 5000, Australia
| | - Anton Blencowe
- Applied Chemistry and Translational Biomaterials (ACTB) Group, Centre for Pharmaceutical Innovation (CPI), UniSA CHS, University of South Australia, Adelaide, South Australia 5000, Australia
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Bernardi M, Cardarelli F. Phasor identifier: A cloud-based analysis of phasor-FLIM data on Python notebooks. BIOPHYSICAL REPORTS 2023; 3:100135. [PMID: 38053971 PMCID: PMC10694583 DOI: 10.1016/j.bpr.2023.100135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 11/03/2023] [Indexed: 12/07/2023]
Abstract
This paper introduces an innovative approach utilizing Google Colaboratory for the versatile analysis of phasor fluorescence lifetime imaging microscopy (FLIM) data collected from various samples (e.g., cuvette, cells, tissues) and in various input file formats. In fact, phasor-FLIM widespread adoption has been hampered by complex instrumentation and data analysis requirements. We mean to make advanced FLIM analysis more accessible to researchers through a cloud-based solution that 1) harnesses robust computational resources, 2) eliminates hardware limitations, and 3) supports both CPU and GPU processing. We envision a paradigm shift in FLIM data accessibility and potential, aligning with the evolving field of artificial intelligence-driven FLIM analysis. This approach simplifies FLIM data handling and opens doors for diverse applications, from studying cellular metabolism to investigating drug encapsulation, benefiting researchers across multiple domains. The comparative analysis of freely distributed FLIM tools highlights the unique advantages of this approach in terms of adaptability, scalability, and open-source nature.
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Bernardi M, Vernizzi M, Baraldi L, Balog S, Bassanetti I, Sgarbi E, Fornasari L, Arrigoni C, Cardarelli F. Phasor-FLIM-guided unraveling of ATRA supramolecular organization in liposomal nanoformulations. NANOSCALE 2023; 15:19085-19090. [PMID: 37991853 DOI: 10.1039/d3nr03420h] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2023]
Abstract
Here we use fluorescence lifetime imaging microscopy (FLIM) to study the supramolecular organization of nanoencapsulated liposomal all-trans retinoic acid (ATRA), exploiting ATRA's intrinsic fluorescence as a source of signal and phasor transformation as a fit-free analytical approach to lifetime data. Our non-invasive method is suitable for checking for the presence of a fraction of ATRA molecules interacting with liposomal membranes. The results are validated by independent small-angle X-ray scattering (SAXS) and nano-differential scanning calorimetry (NanoDSC) measurements, probing ATRA's putative position on the membrane and effect on membrane organization. Besides the insights on the specific case-study proposed, the present results confirm the effectiveness of Phasor-FLIM analysis in elucidating the nanoscale supramolecular organization of fluorescent drugs in pharmaceutical formulations. This underscores the importance of leveraging advanced imaging techniques to deepen our understanding and optimize drugs' performance in delivery applications.
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Affiliation(s)
- Mario Bernardi
- Laboratorio NEST, Scuola Normale Superiore, Pisa, Italy.
| | | | - Laura Baraldi
- Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università di Parma, 43124 Parma, Italy
| | - Sandor Balog
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
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Gottlieb D, Asadipour B, Kostina P, Ung TPL, Stringari C. FLUTE: A Python GUI for interactive phasor analysis of FLIM data. BIOLOGICAL IMAGING 2023; 3:e21. [PMID: 38487690 PMCID: PMC10936343 DOI: 10.1017/s2633903x23000211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 09/16/2023] [Accepted: 10/25/2023] [Indexed: 03/17/2024]
Abstract
Fluorescence lifetime imaging microscopy (FLIM) is a powerful technique used to probe the local environment of fluorophores. The fit-free phasor approach to FLIM data is increasingly being used due to its ease of interpretation. To date, no open-source graphical user interface (GUI) for phasor analysis of FLIM data is available in Python, thus limiting the widespread use of phasor analysis in biomedical research. Here, we present Fluorescence Lifetime Ultimate Explorer (FLUTE), a Python GUI that is designed to fill this gap. FLUTE simplifies and automates many aspects of the analysis of FLIM data acquired in the time domain, such as calibrating the FLIM data, performing interactive exploration of the phasor plot, displaying phasor plots and FLIM images with different lifetime contrasts simultaneously, and calculating the distance from known molecular species. After applying desired filters and thresholds, the final edited datasets can be exported for further user-specific analysis. FLUTE has been tested using several FLIM datasets including autofluorescence of zebrafish embryos and in vitro cells. In summary, our user-friendly GUI extends the advantages of phasor plotting by making the data visualization and analysis easy and interactive, allows for analysis of large FLIM datasets, and accelerates FLIM analysis for non-specialized labs.
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Affiliation(s)
- Dale Gottlieb
- Laboratory for Optics and Biosciences, École Polytechnique, CNRS, INSERM, Institut Polytechnique de Paris, 91128 Palaiseau, France
| | - Bahar Asadipour
- Laboratory for Optics and Biosciences, École Polytechnique, CNRS, INSERM, Institut Polytechnique de Paris, 91128 Palaiseau, France
| | - Polina Kostina
- Laboratory for Optics and Biosciences, École Polytechnique, CNRS, INSERM, Institut Polytechnique de Paris, 91128 Palaiseau, France
| | - Thi Phuong Lien Ung
- Laboratory for Optics and Biosciences, École Polytechnique, CNRS, INSERM, Institut Polytechnique de Paris, 91128 Palaiseau, France
| | - Chiara Stringari
- Laboratory for Optics and Biosciences, École Polytechnique, CNRS, INSERM, Institut Polytechnique de Paris, 91128 Palaiseau, France
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7
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Bernardi M, Signore G, Moscardini A, Pugliese LA, Pesce L, Beltram F, Cardarelli F. Fluorescence Lifetime Nanoscopy of Liposomal Irinotecan Onivyde: From Manufacturing to Intracellular Processing. ACS APPLIED BIO MATERIALS 2023; 6:4277-4289. [PMID: 37699572 PMCID: PMC10583229 DOI: 10.1021/acsabm.3c00478] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 08/27/2023] [Indexed: 09/14/2023]
Abstract
Onivyde was approved by the Food and Drug Administration (FDA) in 2015 for the treatment of solid tumors, including metastatic pancreatic cancer. It is designed to encapsulate irinotecan at high concentration, increase its blood-circulation lifetime, and deliver it to cells where it is enzymatically converted into SN-38, a metabolite with 100- to 1000-fold higher anticancer activity. Despite a rewarding clinical path, little is known about the physical state of encapsulated irinotecan within Onivyde and how this synthetic identity changes throughout the process from manufacturing to intracellular processing. Herein, we exploit irinotecan intrinsic fluorescence and fluorescence lifetime imaging microscopy (FLIM) to selectively probe the supramolecular organization of the drug. FLIM analysis on the manufacturer's formulation reveals the presence of two coexisting physical states within Onivyde liposomes: (i) gelated/precipitated irinotecan and (ii) liposome-membrane-associated irinotecan, the presence of which is not inferable from the manufacturer's indications. FLIM in combination with high-performance liquid chromatography (HPLC) and a membrane-impermeable dynamic quencher of irinotecan reveals rapid (within minutes) and complete chemical dissolution of the gelated/precipitated phase upon Onivyde dilution in standard cell-culturing medium with extensive leakage of the prodrug from liposomes. Indeed, confocal imaging and cell-proliferation assays show that encapsulated and nonencapsulated irinotecan formulations are similar in terms of cell-uptake mechanism and cell-division inhibition. Finally, 2-channel FLIM analysis discriminates the signature of irinotecan from that of its red-shifted SN-38 metabolite, demonstrating the appearance of the latter as a result of Onivyde intracellular processing. The findings presented in this study offer fresh insights into the synthetic identity of Onivyde and its transformation from production to in vitro administration. Moreover, these results serve as another validation of the effectiveness of FLIM analysis in elucidating the supramolecular organization of encapsulated fluorescent drugs. This research underscores the importance of leveraging advanced imaging techniques to deepen our understanding of drug formulations and optimize their performance in delivery applications.
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Affiliation(s)
- Mario Bernardi
- Scuola
Normale Superiore, Laboratorio NEST, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - Giovanni Signore
- Biochemistry
Unit, Department of Biology, University
of Pisa, via San Zeno
51, 56123 Pisa, Italy
- Institute
of Clinical Physiology, National Research
Council, 56124 Pisa, Italy
| | - Aldo Moscardini
- Scuola
Normale Superiore, Laboratorio NEST, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - Licia Anna Pugliese
- Scuola
Normale Superiore, Laboratorio NEST, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - Luca Pesce
- Scuola
Normale Superiore, Laboratorio NEST, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - Fabio Beltram
- Scuola
Normale Superiore, Laboratorio NEST, Piazza San Silvestro 12, 56127 Pisa, Italy
- NEST,
Istituto Nanoscienze-CNR, Piazza S. Silvestro, 12, I-56127 Pisa, Italy
| | - Francesco Cardarelli
- Scuola
Normale Superiore, Laboratorio NEST, Piazza San Silvestro 12, 56127 Pisa, Italy
- NEST,
Istituto Nanoscienze-CNR, Piazza S. Silvestro, 12, I-56127 Pisa, Italy
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Fagihi MA, Premathilaka C, O’Neill T, Garré M, Bhattacharjee S. An Investigation into the Acidity-Induced Insulin Agglomeration: Implications for Drug Delivery and Translation. ACS OMEGA 2023; 8:25279-25287. [PMID: 37483254 PMCID: PMC10357556 DOI: 10.1021/acsomega.3c02482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 06/23/2023] [Indexed: 07/25/2023]
Abstract
Insulin undergoes agglomeration with (subtle) changes in its biochemical environment, including acidity, application of heat, ionic imbalance, and exposure to hydrophobic surfaces. The therapeutic impact of such unwarranted insulin agglomeration is unclear and needs further evaluation. A systematic investigation was conducted on recombinant human insulin-with or without labeling with fluorescein isothiocyanate-while preparing insulin suspensions (0.125, 0.25, and 0.5 mg/mL) at pH 3. The suspensions were incubated (37 °C) and analyzed at different time points (t = 2, 4, 24, 48, and 72 h). Transmission electron microscopy and nanoparticle tracking analysis identified colloidally stable (zeta potential 15 ± 5 mV) spherical agglomerates of unlabeled insulin (100-500 nm). Circular dichroism established the preservation of insulin's secondary structure rich in α-helices despite exposure to an acidic environment (pH 3) for 72 h. Furthermore, fluorescence lifetime imaging microscopy illustrated an acidic core inside these spherical agglomerates, while the acidity gradually lessened toward the periphery. Some of these smaller agglomerates fused to form larger chunks with discrete zones of acidity. The data indicated a primary nucleation-driven mechanism of acid-induced insulin agglomeration under physiologically relevant conditions.
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Affiliation(s)
- Megren
H. A. Fagihi
- School
of Medicine, University College Dublin, Belfield, Dublin 4, Ireland
- Clinical
Laboratory Sciences Department, College of Applied Medical Sciences, Najran University, Najran 55461, Kingdom of Saudi Arabia
| | - Chanaka Premathilaka
- Institute
of Veterinary Medicine and Animal Sciences, Estonian University of Life Sciences, Tartu 51006, Estonia
| | - Tiina O’Neill
- Conway
Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Massimiliano Garré
- Super-Resolution
Imaging Consortium, Royal College of Surgeons
in Ireland University of Medicine and Health Sciences, Dublin D02 YN77, Ireland
| | - Sourav Bhattacharjee
- School of
Veterinary Medicine, University College
Dublin, Belfield, Dublin 4, Ireland
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Azzarello F, Pesce L, De Lorenzi V, Ferri G, Tesi M, Del Guerra S, Marchetti P, Cardarelli F. Single-cell imaging of α and β cell metabolic response to glucose in living human Langerhans islets. Commun Biol 2022; 5:1232. [PMID: 36371562 PMCID: PMC9653440 DOI: 10.1038/s42003-022-04215-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 11/02/2022] [Indexed: 11/13/2022] Open
Abstract
Here we use a combination of two-photon Fluorescence Lifetime Imaging Microscopy (FLIM) of NAD(P)H free/bound ratio in living HIs with post-fixation, immunofluorescence-based, cell-type identification. FLIM allowed to measure variations in the NAD(P)H free/bound ratio induced by glucose; immunofluorescence data allowed to identify single α and β cells; finally, matching of the two datasets allowed to assign metabolic shifts to cell identity. 312 α and 654 β cells from a cohort of 4 healthy donors, 15 total islets, were measured. Both α and β cells display a wide spectrum of responses, towards either an increase or a decrease in NAD(P)H free/bound ratio. Yet, if single-cell data are averaged according to the respective donor and correlated to donor insulin secretion power, a non-random distribution of metabolic shifts emerges: robust average responses of both α and β cells towards an increase of enzyme-bound NAD(P)H belong to the donor with the lowest insulin-secretion power; by contrast, discordant responses, with α cells shifting towards an increase of free NAD(P)H and β cells towards an increase of enzyme-bound NAD(P)H, correspond to the donor with the highest insulin-secretion power. Overall, data reveal neat anti-correlation of tissue metabolic responses with respect to tissue insulin secretion power. A combination of live imaging and immunofluorescence on donor islet cells uncover an anti-correlation of enzyme-bound NAD(P)H and insulin secretion power.
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