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Salerno S, Viviano M, Baglini E, Poggetti V, Giorgini D, Castagnoli J, Barresi E, Castellano S, Da Settimo F, Taliani S. TSPO Radioligands for Neuroinflammation: An Overview. Molecules 2024; 29:4212. [PMID: 39275061 PMCID: PMC11397380 DOI: 10.3390/molecules29174212] [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: 07/29/2024] [Revised: 08/30/2024] [Accepted: 09/03/2024] [Indexed: 09/16/2024] Open
Abstract
The translocator protein (TSPO) is predominately localized on the outer mitochondrial membrane in steroidogenic cells. In the brain, TSPO expression, low under normal conditions, results upregulated in response to glial cell activation, that occurs in neuroinflammation. As a consequence, TSPO has been extensively studied as a biomarker of such conditions by means of TSPO-targeted radiotracers. Although [11C]-PK11195, the prototypical TSPO radioligand, is still widely used for in vivo studies, it is endowed with severe limitations, mainly low sensitivity and poor amenability to quantification. Consequently, several efforts have been focused on the design of new radiotracers for the in vivo imaging of TSPO. The present review will provide an outlook on the latest advances in TSPO radioligands for neuroinflammation imaging. The final goal is to pave the way for (radio)chemists in the future design and development of novel effective and sensitive radiopharmaceuticals targeting TSPO.
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Affiliation(s)
- Silvia Salerno
- Department of Pharmacy, University of Pisa, Via Bonanno 6, 56126 Pisa, Italy; (S.S.); (E.B.); (V.P.); (J.C.); (S.T.)
| | - Monica Viviano
- Department of Pharmacy, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, Italy; (M.V.); (D.G.); (S.C.)
| | - Emma Baglini
- Department of Pharmacy, University of Pisa, Via Bonanno 6, 56126 Pisa, Italy; (S.S.); (E.B.); (V.P.); (J.C.); (S.T.)
| | - Valeria Poggetti
- Department of Pharmacy, University of Pisa, Via Bonanno 6, 56126 Pisa, Italy; (S.S.); (E.B.); (V.P.); (J.C.); (S.T.)
| | - Doralice Giorgini
- Department of Pharmacy, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, Italy; (M.V.); (D.G.); (S.C.)
| | - Jacopo Castagnoli
- Department of Pharmacy, University of Pisa, Via Bonanno 6, 56126 Pisa, Italy; (S.S.); (E.B.); (V.P.); (J.C.); (S.T.)
| | - Elisabetta Barresi
- Department of Pharmacy, University of Pisa, Via Bonanno 6, 56126 Pisa, Italy; (S.S.); (E.B.); (V.P.); (J.C.); (S.T.)
| | - Sabrina Castellano
- Department of Pharmacy, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, Italy; (M.V.); (D.G.); (S.C.)
| | - Federico Da Settimo
- Department of Pharmacy, University of Pisa, Via Bonanno 6, 56126 Pisa, Italy; (S.S.); (E.B.); (V.P.); (J.C.); (S.T.)
| | - Sabrina Taliani
- Department of Pharmacy, University of Pisa, Via Bonanno 6, 56126 Pisa, Italy; (S.S.); (E.B.); (V.P.); (J.C.); (S.T.)
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2
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Viviano M, Barresi E, Siméon FG, Costa B, Taliani S, Da Settimo F, Pike VW, Castellano S. Essential Principles and Recent Progress in the Development of TSPO PET Ligands for Neuroinflammation Imaging. Curr Med Chem 2022; 29:4862-4890. [PMID: 35352645 PMCID: PMC10080361 DOI: 10.2174/0929867329666220329204054] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 12/21/2021] [Accepted: 01/25/2022] [Indexed: 11/22/2022]
Abstract
The translocator protein 18kDa (TSPO) is expressed in the outer mitochondrial membrane and is implicated in several functions, including cholesterol transport and steroidogenesis. Under normal physiological conditions, TSPO is present in very low concentrations in the human brain but is markedly upregulated in response to brain injury and inflammation. This upregulation is strongly associated with activated microglia. Therefore, TSPO is particularly suited for assessing active gliosis associated with brain lesions following injury or disease. For over three decades, TSPO has been studied as a biomarker. Numerous radioligands for positron emission tomography (PET) that target TSPO have been developed for imaging inflammatory progression in the brain. Although [11C]PK11195, the prototypical first-generation PET radioligand, is still widely used for in vivo studies, mainly now as its single more potent R-enantiomer, it has severe limitations, including low sensitivity and poor amenability to quantification. Second-generation radioligands are characterized by higher TSPO specific signals but suffer from other drawbacks, such as sensitivity to the TSPO single nucleotide polymorphism (SNP) rs6971. Therefore, their applications in human studies have the burden of needing to genotype subjects. Consequently, recent efforts are focused on developing improved radioligands that combine the optimal features of the second generation with the ability to overcome the differences in binding affinities across the population. This review presents essential principles in the design and development of TSPO PET ligands and discusses prominent examples among the main chemotypes.
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Affiliation(s)
- Monica Viviano
- Department of Pharmacy, University of Salerno, 84084 Fisciano (SA), Italy
| | | | - Fabrice G. Siméon
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
| | - Barbara Costa
- Department of Pharmacy, University of Pisa, 56126, Pisa, Italy
| | - Sabrina Taliani
- Department of Pharmacy, University of Pisa, 56126, Pisa, Italy
| | | | - Victor W. Pike
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sabrina Castellano
- Department of Pharmacy, University of Salerno, 84084 Fisciano (SA), Italy
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3
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Singh P, Adhikari A, Singh D, Gond C, Tiwari AK. The 18-kDa Translocator Protein PET Tracers as a Diagnostic Marker for Neuroinflammation: Development and Current Standing. ACS OMEGA 2022; 7:14412-14429. [PMID: 35557664 PMCID: PMC9089361 DOI: 10.1021/acsomega.2c00588] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 04/05/2022] [Indexed: 05/13/2023]
Abstract
Translocator protein (TSPO, 18 kDa) is an evolutionary, well-preserved, and tryptophan-rich 169-amino-acid protein which localizes on the contact sites between the outer and inner mitochondrial membranes of steroid-synthesizing cells. This mitochondrial protein is implicated in an extensive range of cellular activities, including steroid synthesis, cholesterol transport, apoptosis, mitochondrial respiration, and cell proliferation. The upregulation of TSPO is well documented in diverse disease conditions including neuroinflammation, cancer, brain injury, and inflammation in peripheral organs. On the basis of these outcomes, TSPO has been assumed to be a fascinating subcellular target for early stage imaging of the diseased state and for therapeutic purposes. The main outline of this Review is to give an update on dealing with the advances made in TSPO PET tracers for neuroinflammation, synchronously emphasizing the approaches applied for the design and advancement of new tracers with reference to their structure-activity relationship (SAR).
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Affiliation(s)
- Priya Singh
- Department
of Chemistry, Babasaheb Bhimrao Ambedkar
University (A Central University), Lucknow, 226025, Uttar Pradesh, India
| | - Anupriya Adhikari
- Department
of Chemistry, Babasaheb Bhimrao Ambedkar
University (A Central University), Lucknow, 226025, Uttar Pradesh, India
| | - Deepika Singh
- Department
of Chemistry, Babasaheb Bhimrao Ambedkar
University (A Central University), Lucknow, 226025, Uttar Pradesh, India
| | - Chandraprakash Gond
- Department
of Chemistry, Babasaheb Bhimrao Ambedkar
University (A Central University), Lucknow, 226025, Uttar Pradesh, India
| | - Anjani Kumar Tiwari
- Department
of Chemistry, Babasaheb Bhimrao Ambedkar
University (A Central University), Lucknow, 226025, Uttar Pradesh, India
- Address:
Department of Chemistry,
Babasaheb Bhimrao Ambedkar University, Lucknow, Uttar Pradesh. Tel.: +91-7503381343. Fax: +91-522-2440821. E-mail:
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4
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Caputo D, Casiello M, Laurenza AG, Fracassi F, Fusco C, Nacci A, D’Accolti L. Preparation of Biowax Esters in Continuous Flow Conditions. ACS OMEGA 2019; 4:12286-12292. [PMID: 31460345 PMCID: PMC6681984 DOI: 10.1021/acsomega.9b00861] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 07/05/2019] [Indexed: 06/10/2023]
Abstract
Biowaxes synthesized from vegetable fatty acids are an alternative to petrochemical paraffins. A simple way of access to these compounds involves Fisher-type esterification of long-chain acids and alcohols under acidic conditions, but long reaction times and harsh conditions are commonly required. In this study, for the first time in the literature, biowax esters are prepared under flow conditions cutting dramatically both reaction times (from 12 h to 30 min) and temperature conditions, with respect to batch procedures (from 90-120 °C to 55 °C). This approach brings substantial improvements to the biowax synthesis process from an economic and environmental point of view, thus making the method up-scalable to the industrial level.
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Affiliation(s)
- Daniela Caputo
- Dipartimento
di Chimica, Università degli Studi
di Bari “A. Moro”, via Orabona 4, 70126 Bari, Italy
- CNR
− Istituto di Chimica dei Composti Organometallici (ICCOM), Bari Section, via Orabona 4, 70126 Bari, Italy
| | - Michele Casiello
- Dipartimento
di Chimica, Università degli Studi
di Bari “A. Moro”, via Orabona 4, 70126 Bari, Italy
| | - Amelita Grazia Laurenza
- Dipartimento
di Chimica, Università degli Studi
di Bari “A. Moro”, via Orabona 4, 70126 Bari, Italy
| | - Francesco Fracassi
- Dipartimento
di Chimica, Università degli Studi
di Bari “A. Moro”, via Orabona 4, 70126 Bari, Italy
| | - Caterina Fusco
- CNR
− Istituto di Chimica dei Composti Organometallici (ICCOM), Bari Section, via Orabona 4, 70126 Bari, Italy
| | - Angelo Nacci
- Dipartimento
di Chimica, Università degli Studi
di Bari “A. Moro”, via Orabona 4, 70126 Bari, Italy
- CNR
− Istituto di Chimica dei Composti Organometallici (ICCOM), Bari Section, via Orabona 4, 70126 Bari, Italy
| | - Lucia D’Accolti
- Dipartimento
di Chimica, Università degli Studi
di Bari “A. Moro”, via Orabona 4, 70126 Bari, Italy
- CNR
− Istituto di Chimica dei Composti Organometallici (ICCOM), Bari Section, via Orabona 4, 70126 Bari, Italy
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5
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Lopalco A, Cutrignelli A, Denora N, Perrone M, Iacobazzi RM, Fanizza E, Lopedota A, Depalo N, de Candia M, Franco M, Laquintana V. Delivery of Proapoptotic Agents in Glioma Cell Lines by TSPO Ligand-Dextran Nanogels. Int J Mol Sci 2018; 19:ijms19041155. [PMID: 29641449 PMCID: PMC5979576 DOI: 10.3390/ijms19041155] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 04/07/2018] [Accepted: 04/08/2018] [Indexed: 12/22/2022] Open
Abstract
Translocator protein 18-kDa (TSPO) is a versatile mitochondrial target for molecular imaging and therapy. Moreover, selective TSPO ligands have been widely investigated for diagnostic purposes and explored to target drug delivery systems directed to cancer cells overexpressing TSPO. Indeed, poly(d,l-lactic-co-glycolic acid (PLGA) polymers and nanocarriers decorated with TSPO ligands are capable of transporting TSPO ligands inside cancer cells, inducing survival inhibition in cancer cells and producing mitochondrial morphology modification. The aim of this work was to prepare nanogels (NGs) made with TSPO ligand dextran conjugates (TSPO-Dex) that are useful as potential delivery systems of two TSPO ligands as apoptotic agents. Synthesis and complete characterization of TSPO–dextran conjugates, an average molecular weights analysis, TSPO ligand release profiles, thermal behaviour and swelling studies were achieved. NG preparation, characterization and in vitro biological studies were also performed. The release of TSPO ligands released from dextran conjugates at 37 °C occurred in human serum at a faster rate than that detected in phosphate buffer. Cytotoxicity studies demonstrated that NGs produced from TSPO ligand–dextran conjugates induce survival inhibition in rat C6 glioma cell lines. Cellular uptake was also proven by fluorescence microscopy.
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Affiliation(s)
- Antonio Lopalco
- Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", Via Orabona, St. 4, 70125 Bari, Italy.
| | - Annalisa Cutrignelli
- Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", Via Orabona, St. 4, 70125 Bari, Italy.
| | - Nunzio Denora
- Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", Via Orabona, St. 4, 70125 Bari, Italy.
- Institute for Physical and Chemical Processes (IPCF)-CNR, SS Bari, Via Orabona, St. 4, 70125 Bari, Italy.
| | - Mara Perrone
- Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", Via Orabona, St. 4, 70125 Bari, Italy.
- Istituto tumori IRCCS "Giovanni Paolo II", Flacco, St. 65, 70124 Bari, Italy.
| | | | - Elisabetta Fanizza
- Institute for Physical and Chemical Processes (IPCF)-CNR, SS Bari, Via Orabona, St. 4, 70125 Bari, Italy.
- Department of Chemistry, University of Bari "Aldo Moro", 70125 Bari, Italy.
| | - Angela Lopedota
- Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", Via Orabona, St. 4, 70125 Bari, Italy.
| | - Nicoletta Depalo
- Institute for Physical and Chemical Processes (IPCF)-CNR, SS Bari, Via Orabona, St. 4, 70125 Bari, Italy.
| | - Modesto de Candia
- Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", Via Orabona, St. 4, 70125 Bari, Italy.
| | - Massimo Franco
- Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", Via Orabona, St. 4, 70125 Bari, Italy.
| | - Valentino Laquintana
- Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", Via Orabona, St. 4, 70125 Bari, Italy.
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6
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An Updated View of Translocator Protein (TSPO). Int J Mol Sci 2017; 18:ijms18122640. [PMID: 29211020 PMCID: PMC5751243 DOI: 10.3390/ijms18122640] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 11/13/2017] [Accepted: 12/04/2017] [Indexed: 01/01/2023] Open
Abstract
Decades of study on the role of mitochondria in living cells have evidenced the importance of the 18 kDa mitochondrial translocator protein (TSPO), first discovered in the 1977 as an alternative binding site for the benzodiazepine diazepam in the kidneys. This protein participates in a variety of cellular functions, including cholesterol transport, steroid hormone synthesis, mitochondrial respiration, permeability transition pore opening, apoptosis, and cell proliferation. Thus, TSPO has become an extremely attractive subcellular target for the early detection of disease states that involve the overexpression of this protein and the selective mitochondrial drug delivery. This special issue was programmed with the aim of summarizing the latest findings about the role of TSPO in eukaryotic cells and as a potential subcellular target of diagnostics or therapeutics. A total of 9 papers have been accepted for publication in this issue, in particular, 2 reviews and 7 primary data manuscripts, overall describing the main advances in this field.
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7
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Iacobazzi RM, Lopalco A, Cutrignelli A, Laquintana V, Lopedota A, Franco M, Denora N. Bridging Pharmaceutical Chemistry with Drug and Nanoparticle Targeting to Investigate the Role of the 18-kDa Translocator Protein TSPO. ChemMedChem 2017; 12:1261-1274. [PMID: 28771957 DOI: 10.1002/cmdc.201700322] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Revised: 07/06/2017] [Indexed: 11/10/2022]
Abstract
An interesting mitochondrial biomarker is the 18-kDa mitochondrial translocator protein (TSPO). Decades of study have shown that this protein plays an important role in a wide range of cellular functions, including opening of the mitochondrial permeability transition pore as well as programmed cell death and proliferation. Variations in TSPO expression have been correlated to different diseases, from tumors to endocrine and neurological disorders. TSPO has therefore become an appealing target for both early diagnosis and selective mitochondrial drug delivery. The number of structurally different TSPO ligands examined has increased over time, highlighting the scientific community's growing understanding of the roles of TSPO in normal and pathological conditions. However, only few TSPO ligands are characterized by the presence of groups that are potentially derivatizable; therefore only few such ligands are well suited for the preparation of targeted prodrugs or nanocarriers able to deliver therapeutics and/or diagnostic agents to mitochondria. This review provides an overview of the very few examples of drug delivery systems characterized by moieties that target TSPO.
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Affiliation(s)
| | - Antonio Lopalco
- Dipartimento di Farmacia-Scienze del Farmaco, Università degli Studi di Bari Aldo Moro, Via Orabona 4, 70125, Bari, Italy
| | - Annalisa Cutrignelli
- Dipartimento di Farmacia-Scienze del Farmaco, Università degli Studi di Bari Aldo Moro, Via Orabona 4, 70125, Bari, Italy
| | - Valentino Laquintana
- Dipartimento di Farmacia-Scienze del Farmaco, Università degli Studi di Bari Aldo Moro, Via Orabona 4, 70125, Bari, Italy
| | - Angela Lopedota
- Dipartimento di Farmacia-Scienze del Farmaco, Università degli Studi di Bari Aldo Moro, Via Orabona 4, 70125, Bari, Italy
| | - Massimo Franco
- Dipartimento di Farmacia-Scienze del Farmaco, Università degli Studi di Bari Aldo Moro, Via Orabona 4, 70125, Bari, Italy
| | - Nunzio Denora
- Dipartimento di Farmacia-Scienze del Farmaco, Università degli Studi di Bari Aldo Moro, Via Orabona 4, 70125, Bari, Italy
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8
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Alam MM, Lee J, Lee SY. Recent Progress in the Development of TSPO PET Ligands for Neuroinflammation Imaging in Neurological Diseases. Nucl Med Mol Imaging 2017; 51:283-296. [PMID: 29242722 DOI: 10.1007/s13139-017-0475-8] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 12/08/2016] [Accepted: 02/06/2017] [Indexed: 12/13/2022] Open
Abstract
Neuroinflammation is heavily associated with various neurological diseases including Alzheimer's disease, Parkinson's disease, multiple sclerosis, and stroke. It is strongly characterized by the activation of microglia which can be visualized using position emission tomography (PET). Traditionally, translocator protein 18 kDa (TSPO) has been the preferred target for imaging the inflammatory progression of the microglial component. TSPO is expressed in the outer mitochondrial membrane and present in very low concentrations in the healthy human brain, but is markedly upregulated in response to brain injury and inflammation. Due to its value as a marker of microglial activation and subsequent utility for evaluating neuroinflammation in CNS disorders, several classes of TSPO radioligands have been developed and evaluated. However, the application of these second-generation TSPO radiotracers has been subject to several limiting factors, including a polymorphism that affects TSPO binding. This review focuses on recent developments in TSPO imaging, as well as current limitations and suggestions for future directions from a medical imaging perspective.
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Affiliation(s)
- Md Maqusood Alam
- Neuroscience Research Institute, Gachon University, Incheon, 20565 South Korea
| | - Jihye Lee
- Neuroscience Research Institute, Gachon University, Incheon, 20565 South Korea
| | - Sang-Yoon Lee
- Neuroscience Research Institute, Gachon University, Incheon, 20565 South Korea.,Department of Neuroscience, College of Medicine, Gachon University, Incheon, 21936 South Korea
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In Vivo Detection of Age- and Disease-Related Increases in Neuroinflammation by 18F-GE180 TSPO MicroPET Imaging in Wild-Type and Alzheimer's Transgenic Mice. J Neurosci 2016; 35:15716-30. [PMID: 26609163 DOI: 10.1523/jneurosci.0996-15.2015] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
UNLABELLED Alzheimer's disease (AD) is the most common cause of dementia. Neuroinflammation appears to play an important role in AD pathogenesis. Ligands of the 18 kDa translocator protein (TSPO), a marker for activated microglia, have been used as positron emission tomography (PET) tracers to reflect neuroinflammation in humans and mouse models. Here, we used the novel TSPO-targeted PET tracer (18)F-GE180 (flutriciclamide) to investigate differences in neuroinflammation between young and old WT and APP/PS1dE9 transgenic (Tg) mice. In vivo PET scans revealed an overt age-dependent elevation in whole-brain uptake of (18)F-GE180 in both WT and Tg mice, and a significant increase in whole-brain uptake of (18)F-GE180 (peak-uptake and retention) in old Tg mice compared with young Tg mice and all WT mice. Similarly, the (18)F-GE180 binding potential in hippocampus was highest to lowest in old Tg > old WT > young Tg > young WT mice using MRI coregistration. Ex vivo PET and autoradiography analysis further confirmed our in vivo PET results: enhanced uptake and specific binding (SUV75%) of (18)F-GE180 in hippocampus and cortex was highest in old Tg mice followed by old WT, young Tg, and finally young WT mice. (18)F-GE180 specificity was confirmed by an in vivo cold tracer competition study. We also examined (18)F-GE180 metabolites in 4-month-old WT mice and found that, although total radioactivity declined over 2 h, of the remaining radioactivity, ∼90% was due to parent (18)F-GE180. In conclusion, (18)F-GE180 PET scans may be useful for longitudinal monitoring of neuroinflammation during AD progression and treatment. SIGNIFICANCE STATEMENT Microglial activation, a player in Alzheimer's disease (AD) pathogenesis, is thought to reflect neuroinflammation. Using in vivo microPET imaging with a novel TSPO radioligand, (18)F-GE180, we detected significantly enhanced neuroinflammation during normal aging in WT mice and in response to AD-associated pathology in APP/PS1dE9 Tg mice, an AD mouse model. Increased uptake and specific binding of (18)F-GE180 in whole brain and hippocampus were confirmed by ex vivo PET and autoradiography. The binding specificity and stability of (18)F-GE180 was further confirmed by a cold tracer competition study and a metabolite study, respectively. Therefore, (18)F-GE180 PET imaging may be useful for longitudinal monitoring of neuroinflammation during AD progression and treatment and may also be useful for other neurodegenerative diseases.
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10
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Fanizza E, Iacobazzi RM, Laquintana V, Valente G, Caliandro G, Striccoli M, Agostiano A, Cutrignelli A, Lopedota A, Curri ML, Franco M, Depalo N, Denora N. Highly selective luminescent nanostructures for mitochondrial imaging and targeting. NANOSCALE 2016; 8:3350-3361. [PMID: 26763470 DOI: 10.1039/c5nr08139d] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Here a luminescent hybrid nanostructure based on functionalized quantum dots (QDs) is used as a fluorescent imaging agent able to target selectively mitochondria thanks to the molecular recognition of the translocator protein (TSPO). The selective targeting of such an 18 kDa protein mainly located in the outer mitochondrial membrane and overexpressed in several pathological states including neurodegenerative diseases and cancers may provide valuable information for the early diagnosis and therapy of human disorders. In particular, the rational design of amino functionalized luminescent silica coated QD nanoparticles (QD@SiO2 NPs) provides a versatile nanoplatform to anchor a potent and selective TSPO ligand, characterized by a 2-phenyl-imidazo[1,2-a]pyridine acetamide structure along with a derivatizable carboxylic end group, useful to conjugate the TSPO ligand and achieve TSPO-QD@SiO2 NPs by means of a covalent amide bond. The colloidal stability and optical properties of the proposed nanomaterials are comprehensively investigated and their potential as mitochondrial imaging agents is fully assessed. Sub-cellular fractionation, together with confocal laser scanning fluorescence microscopy and co-localization analysis of targeted TSPO-QD@SiO2 NPs in C6 glioma cells overexpressing the TSPO, proves the great potential of these multifunctional nanosystems as in vitro selective mitochondrial imaging agents.
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Affiliation(s)
- E Fanizza
- Dipartimento di Chimica, Università degli Studi di Bari "Aldo Moro", Via Orabona 4, 70126 Bari, Italy
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11
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A Novel PET Imaging Probe for the Detection and Monitoring of Translocator Protein 18 kDa Expression in Pathological Disorders. Sci Rep 2016; 6:20422. [PMID: 26853260 PMCID: PMC4745082 DOI: 10.1038/srep20422] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 01/04/2016] [Indexed: 11/16/2022] Open
Abstract
A new fluorine-substituted ligand, compound 1 (CB251), with a very high affinity (Ki = 0.27 ± 0.09 nM) and selectivity for the 18-kDa translocator protein (TSPO), is presented as an attractive biomarker for the diagnosis of neuroinflammation, neurodegeneration and tumour progression. To test compound 1 as a TSPO PET imaging agent in vivo, 2-(2-(4-(2-[18F]fluoroethoxy)phenyl)-6,8-dichloroimidazo[1,2-a]pyridin-3-yl)-N,N-dipropylacetamide ([18F]1; [18F]CB251) was synthesized by nucleophilic aliphatic substitution in a single-step radiolabelling procedure with a 11.1 ± 3.5% (n = 14, decay corrected) radiochemical yield and over 99% radiochemical purity. In animal PET imaging studies, [18F]CB251 provided a clearly visible image of the inflammatory lesion with the binding potential of the specifically bound radioligand relative to the non-displaceable radioligand in tissue (BPND 1.83 ± 0.18), in a neuroinflammation rat model based on the unilateral stereotaxic injection of lipopolysaccharide (LPS), comparable to that of [11C]PBR28 (BPND 1.55 ± 0.41). [18F]CB251 showed moderate tumour uptake (1.96 ± 0.11%ID/g at 1 h post injection) in human glioblastoma U87-MG xenografts. These results suggest that [18F]CB251 is a promising TSPO PET imaging agent for neuroinflammation and TSPO-rich cancers.
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12
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Damont A, Médran-Navarrete V, Cacheux F, Kuhnast B, Pottier G, Bernards N, Marguet F, Puech F, Boisgard R, Dollé F. Novel Pyrazolo[1,5-a]pyrimidines as Translocator Protein 18 kDa (TSPO) Ligands: Synthesis, in Vitro Biological Evaluation, [(18)F]-Labeling, and in Vivo Neuroinflammation PET Images. J Med Chem 2015; 58:7449-64. [PMID: 26280386 DOI: 10.1021/acs.jmedchem.5b00932] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
A series of novel pyrazolo[1,5-a]pyrimidines, closely related to N,N-diethyl-2-(2-(4-(2-fluoroethoxy)phenyl)-5,7-dimethylpyrazolo[1,5-a]pyrimidin-3-yl)acetamide (2, DPA-714), were synthesized and biologically in vitro evaluated for their potential to bind the translocator protein 18 kDa (TSPO), a protein today recognized as an early biomarker of neuroinflammatory processes. This series is composed of fluoroalkyl- and fluoroalkynyl- analogues, prepared from a common iodinated intermediate via Sonogashira coupling reactions. All derivatives displayed subnanomolar affinity for the TSPO (0.37 to 0.86 nM), comparable to that of 2 (0.91 nM). Two of them were radiolabeled with fluorine-18, and their biodistribution was investigated by in vitro autoradiography and positron emission tomography (PET) imaging on a rodent model of neuroinflammation. Brain uptake and local accumulation of both compounds in the AMPA-mediated lesion confirm their potential as in vivo PET-radiotracers. In particular, [(18)F]23 exhibited a significantly higher ipsi- to contralateral ratio at 60 min than the parent molecule [(18)F]2 in vivo.
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Affiliation(s)
- Annelaure Damont
- CEA, I2BM, Service Hospitalier Frédéric Joliot, Orsay, France.,Inserm/CEA/Université Paris Sud, UMR 1023-ERL 9218 CNRS, IMIV, Orsay, France
| | - Vincent Médran-Navarrete
- CEA, I2BM, Service Hospitalier Frédéric Joliot, Orsay, France.,Inserm/CEA/Université Paris Sud, UMR 1023-ERL 9218 CNRS, IMIV, Orsay, France
| | - Fanny Cacheux
- CEA, I2BM, Service Hospitalier Frédéric Joliot, Orsay, France.,Inserm/CEA/Université Paris Sud, UMR 1023-ERL 9218 CNRS, IMIV, Orsay, France
| | - Bertrand Kuhnast
- CEA, I2BM, Service Hospitalier Frédéric Joliot, Orsay, France.,Inserm/CEA/Université Paris Sud, UMR 1023-ERL 9218 CNRS, IMIV, Orsay, France
| | - Géraldine Pottier
- CEA, I2BM, Service Hospitalier Frédéric Joliot, Orsay, France.,Inserm/CEA/Université Paris Sud, UMR 1023-ERL 9218 CNRS, IMIV, Orsay, France
| | - Nicholas Bernards
- CEA, I2BM, Service Hospitalier Frédéric Joliot, Orsay, France.,Inserm/CEA/Université Paris Sud, UMR 1023-ERL 9218 CNRS, IMIV, Orsay, France
| | | | | | - Raphaël Boisgard
- CEA, I2BM, Service Hospitalier Frédéric Joliot, Orsay, France.,Inserm/CEA/Université Paris Sud, UMR 1023-ERL 9218 CNRS, IMIV, Orsay, France
| | - Frédéric Dollé
- CEA, I2BM, Service Hospitalier Frédéric Joliot, Orsay, France.,Inserm/CEA/Université Paris Sud, UMR 1023-ERL 9218 CNRS, IMIV, Orsay, France
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13
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The translocator protein as a potential molecular target for improved treatment efficacy in photodynamic therapy. Future Med Chem 2015; 6:775-92. [PMID: 24941872 DOI: 10.4155/fmc.14.37] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Since its serendipitous discovery over 30 years ago, the translocator protein (18 kDa) has been demonstrated to play an important role in a multitude of critical biological processes. Although implemented as a novel therapeutic and diagnostic tool for a variety of disease states, its most promising role is as a molecular target for anticancer treatments such as photodynamic therapy (PDT). This review gives an overview of the attempts made by researchers to design porphyrin-based photosensitizers for use as anticancer therapeutics in PDT as well as improved imaging agents for diagnostic purposes. With a better understanding of the structure and function of the translocator protein, the synthesis of porphyrins for use in PDT with optimum binding affinities will become ever more possible.
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Hatano K, Sekimata K, Yamada T, Abe J, Ito K, Ogawa M, Magata Y, Toyohara J, Ishiwata K, Biggio G, Serra M, Laquintana V, Denora N, Latrofa A, Trapani G, Liso G, Suzuki H, Sawada M, Nomura M, Toyama H. Radiosynthesis and in vivo evaluation of two imidazopyridineacetamides, [(11)C]CB184 and [ (11)C]CB190, as a PET tracer for 18 kDa translocator protein: direct comparison with [ (11)C](R)-PK11195. Ann Nucl Med 2015; 29:325-35. [PMID: 25616581 PMCID: PMC4835529 DOI: 10.1007/s12149-015-0948-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 01/14/2015] [Indexed: 10/31/2022]
Abstract
OBJECTIVE We report synthesis of two carbon-11 labeled imidazopyridines TSPO ligands, [(11)C]CB184 and [(11)C]CB190, for PET imaging of inflammatory process along with neurodegeneration, ischemia or brain tumor. Biodistribution of these compounds was compared with that of [(11)C]CB148 and [(11)C](R)-PK11195. METHODS Both [(11)C]CB184 and [(11)C]CB190 having (11)C-methoxyl group on an aromatic ring were readily prepared using [(11)C]methyl triflate. Biodistribution and metabolism of the compounds were examined with normal mice. An animal PET study using 6-hydroxydopamine treated rats as a model of neurodegeneration was pursued for proper estimation of feasibility of the radioligands to determine neuroinflammation process. RESULTS [(11)C]CB184 and [(11)C]CB190 were obtained via O-methylation of corresponding desmethyl precursor using [(11)C]methyl triflate in radiochemical yield of 73 % (decay-corrected). In vivo validation as a TSPO radioligand was carried out using normal mice and lesioned rats. In mice, [(11)C]CB184 showed more uptake and specific binding than [(11)C]CB190. Metabolism studies showed that 36 % and 25 % of radioactivity in plasma remained unchanged 30 min after intravenous injection of [(11)C]CB184 and [(11)C]CB190, respectively. In the PET study using rats, lesioned side of the brain showed significantly higher uptake than contralateral side after i.v. injection of either [(11)C]CB184 or [(11)C](R)-PK11195. Indirect Logan plot analysis revealed distribution volume ratio (DVR) between the two sides which might indicate lesion-related elevation of TSPO binding. The DVR was 1.15 ± 0.10 for [(11)C](R)-PK11195 and was 1.15 ± 0.09 for [(11)C]CB184. CONCLUSION The sensitivity to detect neuroinflammation activity was similar for [(11)C]CB184 and [(11)C](R)-PK11195.
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Affiliation(s)
- Kentaro Hatano
- Department of Clinical and Experimental Neuroimaging, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Obu, Aichi, 474-8522, Japan,
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15
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Bourdier T, Henderson D, Fookes CJ, Lam P, Mattner F, Fulham M, Katsifis A. Synthesis of [11C]PBR170, a novel imidazopyridine, for imaging the translocator protein with PET. Appl Radiat Isot 2014; 90:46-52. [DOI: 10.1016/j.apradiso.2014.03.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 02/26/2014] [Accepted: 03/08/2014] [Indexed: 10/25/2022]
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16
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Laquintana V, Denora N, Lopalco A, Lopedota A, Cutrignelli A, Lasorsa FM, Agostino G, Franco M. Translocator Protein Ligand–PLGA Conjugated Nanoparticles for 5-Fluorouracil Delivery to Glioma Cancer Cells. Mol Pharm 2014; 11:859-71. [DOI: 10.1021/mp400536z] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Valentino Laquintana
- Dipartimento
di Farmacia-Scienze del Farmaco, Università degli Studi di Bari “Aldo Moro”, via Orabona 4, 70125 Bari, Italy
| | - Nunzio Denora
- Dipartimento
di Farmacia-Scienze del Farmaco, Università degli Studi di Bari “Aldo Moro”, via Orabona 4, 70125 Bari, Italy
| | - Antonio Lopalco
- Dipartimento
di Farmacia-Scienze del Farmaco, Università degli Studi di Bari “Aldo Moro”, via Orabona 4, 70125 Bari, Italy
| | - Angela Lopedota
- Dipartimento
di Farmacia-Scienze del Farmaco, Università degli Studi di Bari “Aldo Moro”, via Orabona 4, 70125 Bari, Italy
| | - Annalisa Cutrignelli
- Dipartimento
di Farmacia-Scienze del Farmaco, Università degli Studi di Bari “Aldo Moro”, via Orabona 4, 70125 Bari, Italy
| | | | - Giulia Agostino
- Dipartimento
di Bioscienze, Biotecnologie e Biofarmaceutica, Università degli Studi di Bari “Aldo Moro”, via Orabona 4, 70125 Bari, Italy
| | - Massimo Franco
- Dipartimento
di Farmacia-Scienze del Farmaco, Università degli Studi di Bari “Aldo Moro”, via Orabona 4, 70125 Bari, Italy
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Denora N, Laquintana V, Lopalco A, Iacobazzi RM, Lopedota A, Cutrignelli A, Iacobellis G, Annese C, Cascione M, Leporatti S, Franco M. In vitro targeting and imaging the translocator protein TSPO 18-kDa through G(4)-PAMAM–FITC labeled dendrimer. J Control Release 2013; 172:1111-25. [DOI: 10.1016/j.jconrel.2013.09.024] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 09/15/2013] [Accepted: 09/18/2013] [Indexed: 01/25/2023]
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18
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Trapani A, Palazzo C, de Candia M, Lasorsa FM, Trapani G. Targeting of the Translocator Protein 18 kDa (TSPO): A Valuable Approach for Nuclear and Optical Imaging of Activated Microglia. Bioconjug Chem 2013; 24:1415-28. [DOI: 10.1021/bc300666f] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Adriana Trapani
- Department of Pharmacy and Drug
Sciences, University of Bari, Bari, 70125,
Italy
| | - Claudio Palazzo
- Department of Pharmacy and Drug
Sciences, University of Bari, Bari, 70125,
Italy
| | - Modesto de Candia
- Department of Pharmacy and Drug
Sciences, University of Bari, Bari, 70125,
Italy
| | | | - Giuseppe Trapani
- Department of Pharmacy and Drug
Sciences, University of Bari, Bari, 70125,
Italy
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Denora N, Laquintana V, Trapani A, Suzuki H, Sawada M, Trapani G. New fluorescent probes targeting the mitochondrial-located translocator protein 18 kDa (TSPO) as activated microglia imaging agents. Pharm Res 2011; 28:2820-32. [PMID: 21818711 DOI: 10.1007/s11095-011-0552-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Accepted: 07/28/2011] [Indexed: 11/28/2022]
Abstract
PURPOSE To evaluate the utility of new Translocator protein 18 kDa (TSPO)-targeted fluorescent probes for in vivo molecular imaging of activated microglia. METHODS Compounds 2-4 were synthesized; their stability and affinity for TSPO were determined. Compounds 2-4 were incubated both with Ra2 cells in the presence of LPS, a potent activator of microglia, and with tissue sections of normal and chemically injured brains. Compounds 2-4 were injected into carotid artery or directly in striatum of mice. Cells and tissue sections from these in vitro and in vivo studies were observed by fluorescence microscopy after histochemical treatments. RESULTS Compounds 2-4 are stable in both buffer and physiological medium and showed high affinity for TSPO and were found to stain live Ra2 microglial cells effectively. Double staining with Mito Tracker Red suggested that binding sites of compounds 2 and 3 may exist on mitochondria. In vivo studies showed that compounds 2-4 may penetrate in part into brain; moreover, cells in mouse striatum were stained with compounds 2-4 and microglial marker CD11b. CONCLUSION Compounds 2-4 can fluorescently label activated microglia in vitro and in vivo.
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Affiliation(s)
- Nunzio Denora
- Dipartimento Farmaco-Chimico, Facoltà di Farmacia, Università degli Studi di Bari, Via Orabona 4, 70125 Bari, Italy
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20
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Zhang Y, Sun Y, Xu X, Zhang X, Zhu H, Huang L, Qi Y, Shen YM. Synthesis, biodistribution, and microsingle photon emission computed tomography (SPECT) imaging study of technetium-99m labeled PEGylated dendrimer poly(amidoamine) (PAMAM)-folic acid conjugates. J Med Chem 2010; 53:3262-72. [PMID: 20350006 DOI: 10.1021/jm901910j] [Citation(s) in RCA: 104] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Three conjugates based on dendrimer PAMAM generation five were synthesized and radiolabeled successfully. To investigate their tumor targeting, the in vitro and in vivo stability, cell uptake, in vivo biodistribution, and micro-SPECT imaging were evaluated, respectively. The conjugate of (99m)Tc labeled PEGylated dendrimer PAMAM folic acid conjugate ((99m)Tc-G5-Ac-pegFA-DTPA) shows much higher uptake in KB cancer cells and accumulated more in the tumor area than that of the other two conjugates. The uptake in KB cells depends on the incubation time. The results of in vivo biodistribution agree with the data obtained from micro-SPECT imaging. These studies show that PEGylation of PAMAM dendrimer folic acid conjugate improves the tumor targeting. Folate-conjugated dendrimer maybe developed to be potential radiopharmaceuticals and targeted drug delivery systems.
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Affiliation(s)
- Yuanqing Zhang
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, 2019 Baojia Road, Shanghai 201800, China
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21
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Laquintana V, Trapani A, Denora N, Wang F, Gallo JM, Trapani G. New strategies to deliver anticancer drugs to brain tumors. Expert Opin Drug Deliv 2009; 6:1017-32. [PMID: 19732031 DOI: 10.1517/17425240903167942] [Citation(s) in RCA: 137] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Malignant brain tumors are among the most challenging to treat and at present there are no uniformly successful treatment strategies. Standard treatment regimens consist of maximal surgical resection followed by radiotherapy and chemotherapy. The limited survival advantage attributed to chemotherapy is partially due to low CNS penetration of antineoplastic agents across the blood-brain barrier (BBB). OBJECTIVE The objective of this paper is to review recent approaches to delivering anticancer drugs into primary brain tumors. METHODS Both preclinical and clinical strategies to circumvent the BBB are considered that include chemical modification and colloidal carriers. CONCLUSION Analysis of the available data indicates that new approaches may be useful for CNS delivery, yet an appreciation of pharmacokinetic issues and improved knowledge of tumor biology will be needed to affect significantly drug delivery to the target site.
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Venneti S, Wiley CA, Kofler J. Imaging microglial activation during neuroinflammation and Alzheimer's disease. J Neuroimmune Pharmacol 2009; 4:227-43. [PMID: 19052878 PMCID: PMC2682630 DOI: 10.1007/s11481-008-9142-2] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2008] [Accepted: 11/17/2008] [Indexed: 01/07/2023]
Abstract
Microglial activation is an important pathogenic component of neurodegenerative disease processes. This state of increased inflammation is associated not only with neurotoxic consequences but also neuroprotective effects, e.g., phagocytosis and clearance of amyloid in Alzheimer's disease. In addition, activation of microglia appears to be one of the major mechanisms of amyloid clearance following active or passive immunotherapy. Imaging techniques may provide a minimally invasive tool to elucidate the complexities and dynamics of microglial function and dysfunction in aging and neurodegenerative diseases. Imaging microglia in vivo in live subjects by confocal or two/multiphoton microscopy offers the advantage of studying these cells over time in their native environment. Imaging microglia in human subjects by positron emission tomography scanning with translocator protein-18 kDa ligands can offer a measure of the inflammatory process and a means of detecting progression of disease and efficacy of therapeutics over time.
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Affiliation(s)
- Sriram Venneti
- Department of Pathology and Laboratory Medicine, Hospital of the University of Pennsylvania, 3400 Spruce St, 6.093 Founders Building, Philadelphia, PA 19104, USA e-mail:
| | - Clayton A. Wiley
- Department of Pathology, University of Pittsburgh School of Medicine, 200 Lothrop Street, A-506, Pittsburgh, PA 15213, USA
| | - Julia Kofler
- Department of Pathology, University of Pittsburgh School of Medicine, 200 Lothrop Street, A-506, Pittsburgh, PA 15213, USA
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Laquintana V, Denora N, Musacchio T, Lasorsa M, Latrofa A, Trapani G. Peripheral benzodiazepine receptor ligand-PLGA polymer conjugates potentially useful as delivery systems of apoptotic agents. J Control Release 2009; 137:185-95. [PMID: 19374931 DOI: 10.1016/j.jconrel.2009.04.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2009] [Revised: 04/07/2009] [Accepted: 04/07/2009] [Indexed: 10/20/2022]
Abstract
Poly(d,l-lactic-co-glycolic acid) (PLGA) polymers having different average molecular weights were chemically conjugated to two imidazopyridinacetamides (1 and 2), chosen as model Peripheral Benzodiazepine Receptor (PBR) ligands, via an ester or amide linkage. It is in order to evaluate these conjugates as delivery systems of PBR ligands endowed with apoptosis inducing activity. Various coupling reaction conditions were tested to optimize the conjugation process. After purification by extensive dialysis procedures, the macromolecular conjugates were characterized by FT-IR, UV, (1)H NMR spectroscopy, DSC and the average molecular weights of synthesized conjugates were determined by GPC. PBR ligand released from these conjugates occurred in human serum and in 0.1 N HCl solution at a faster rate than that observed in phosphate buffer, pH 7.4. Moreover, the macromolecular conjugates displayed high affinity and selectivity for PBR. Cytotoxicity studies demonstrated that PBR ligand-PLGA polymer conjugates induce survival inhibition in rat C6 glioma cell line. Fluorescence microscopy studies evidenced the cellular uptake of FITC-conjugated probes 10 and 11 and moreover, the mitochondrial morphology modification induced by compounds 1 and 4a. Therefore, this study demonstrates that this PBR ligand-PLGA combination may provide a new mitochondrial targeted approach useful for improved cancer chemotherapy.
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Affiliation(s)
- Valentino Laquintana
- Pharmaco-Chemistry Department, Faculty of Pharmacy, University of Bari, 70125 Bari, Italy
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Nuclear imaging of neuroinflammation: a comprehensive review of [11C]PK11195 challengers. Eur J Nucl Med Mol Imaging 2008; 35:2304-19. [DOI: 10.1007/s00259-008-0908-9] [Citation(s) in RCA: 324] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2008] [Accepted: 07/17/2008] [Indexed: 12/22/2022]
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