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Damuka N, Irmen RE, Krizan I, Miller M, Gollapelli KK, Bhoopal B, Deep O, Bansode A, Lockhart SN, Orr ME, Jadiya P, Bashetti N, Kumar JVS, Mintz A, Whitlow CT, Craft S, Macauley SL, Solingapuram Sai KK. Exploring microtubule dynamics in Alzheimer's disease: Longitudinal assessment using [ 11C]MPC-6827 PET imaging in rodent models of Alzheimer's-related pathology. Alzheimers Dement 2024. [PMID: 38967283 DOI: 10.1002/alz.14083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Revised: 05/28/2024] [Accepted: 05/29/2024] [Indexed: 07/06/2024]
Abstract
INTRODUCTION Microtubule (MT) stability is crucial for proper neuronal function. Understanding MT dysregulation is critical for connecting amyloid beta (Aβ) and tau-based degenerative events and early changes in presymptomatic Alzheimer's disease (AD). Herein we present positron emission tomography (PET) imaging properties of our MT-PET radiotracer, [11C]MPC-6827, in multiple established AD mouse models. METHODS Longitudinal PET, biodistribution, autoradiography, immunohistochemistry, and behavioral studies were conducted at multiple time points in APPswe/PSEN1dE9 (APP/PS1), P301S-PS19 (P301S), 5xFAD, and age-matched control mice. RESULTS Longitudinal [11C]MPC-6827 brain imaging showed significant increases in APP/PS1, P301S, and 5xFAD mice compared to controls. Longitudinal MT-PET correlated positively with biodistribution, autoradiography, and immunohistochemistry results and negatively with behavior data. DISCUSSION Our study demonstrated significant longitudinal [11C]MPC-6827 PET increases in multiple AD mouse models for the first time. Strong correlations between PET and biomarker data underscored the interplay of MT destabilization, amyloid, and tau pathology in AD. These results suggest [11C]MPC-6827 PET as a promising tool for monitoring MT dysregulation early in AD progression. HIGHLIGHTS Longitudinal positron emission tomography (PET) imaging studies using [11C]MPC-6827 in multiple established Alzheimer's disease (AD) mouse models revealed an early onset of microtubule dysregulation, with significant changes in brain radiotracer uptake evident from 2 to 4 months of age. Intra-group analysis showed a progressive increase in microtubule dysregulation with increasing AD burden, supported by significant correlations between PET imaging data and biodistribution, autoradiography, and molecular pathological markers. [11C]MPC-6827 PET imaging demonstrated its efficacy in detecting early microtubule alterations preceding observable behavioral changes in AD mouse models, suggesting its potential for early AD imaging. The inclusion of the 5xFAD mouse model further elucidated the impact of amyloid beta (Aβ) toxicity on inducing tau hyperphosphorylation-mediated microtubule dysregulation, highlighting the versatility of [11C]MPC-6827 in delineating various aspects of AD pathology. Our study provides immediate clarity on high uptake of the microtubule-based radiotracer in AD brains in a longitudinal setting, which directly informs clinical utility in Aβ/tau-based studies.
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Affiliation(s)
- Naresh Damuka
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Riley E Irmen
- Department of Physiology, University of Kentucky, Lexington, Kentucky, USA
| | - Ivan Krizan
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Mack Miller
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Krishna K Gollapelli
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Bhuvanachandra Bhoopal
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Ojasvi Deep
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Avinash Bansode
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Samuel N Lockhart
- Department of Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Miranda E Orr
- Department of Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Pooja Jadiya
- Department of Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Nagaraju Bashetti
- Department of Chemistry, Koneru Lakshmaiah Education Foundation, Vijayawada, Andhra Pradesh, India
| | - J V Shanmukha Kumar
- Department of Chemistry, Koneru Lakshmaiah Education Foundation, Vijayawada, Andhra Pradesh, India
| | - Akiva Mintz
- Department of Radiology, Columbia University Medical Center, New York, New York, USA
| | - Christopher T Whitlow
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Suzanne Craft
- Department of Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Shannon L Macauley
- Department of Physiology, University of Kentucky, Lexington, Kentucky, USA
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Bansode AH, Damuka N, Bashetti N, Gollapelli KK, Krizan I, Bhoopal B, Miller M, Jv SK, Whitlow CT, McClain D, Ma T, Jorgensen MJ, Solingapuram Sai KK. First GPR119 PET Imaging Ligand: Synthesis, Radiochemistry, and Preliminary Evaluations. J Med Chem 2023; 66:9120-9129. [PMID: 37315328 PMCID: PMC10999001 DOI: 10.1021/acs.jmedchem.3c00720] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
G-protein-coupled receptor 119 (GPR119) has emerged as a promising target for treating type 2 diabetes mellitus. Activating GPR119 improves glucose homeostasis, while suppressing appetite and weight gain. Measuring GPR119 levels in vivo could significantly advance GPR119-based drug development strategies including target engagement, occupancy, and distribution studies. To date, no positron emission tomography (PET) ligands are available to image GPR119. In this paper, we report the synthesis, radiolabeling, and preliminary biological evaluations of a novel PET radiotracer [18F]KSS3 to image GPR119. PET imaging will provide information on GPR119 changes with diabetic glycemic loads and the efficacy of GPR119 agonists as antidiabetic drugs. Our results demonstrate [18F]KSS3's high radiochemical purity, specific activity, cellular uptake, and in vivo and ex vivo uptake in pancreas, liver, and gut regions, with high GPR119 expression. Cell pretreatment with nonradioactive KSS3, rodent PET imaging, biodistribution, and autoradiography studies showed significant blocking in the pancreas showing [18F]KSS3's high specificity.
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Affiliation(s)
- Avinash H Bansode
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157, United States
| | - Naresh Damuka
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157, United States
| | - Nagaraju Bashetti
- Department of Chemistry, Koneru Lakshmaiah Education Foundation, Vijayawada, 522302 Andhra Pradesh, India
| | - Krishna Kumar Gollapelli
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157, United States
| | - Ivan Krizan
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157, United States
| | - Bhuvanachandra Bhoopal
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157, United States
| | - Mack Miller
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157, United States
| | - Shanmukha Kumar Jv
- Department of Chemistry, Koneru Lakshmaiah Education Foundation, Vijayawada, 522302 Andhra Pradesh, India
| | - Christopher T Whitlow
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157, United States
| | - Donald McClain
- Department of Endocrinology, Wake Forest School of Medicine, Winston Salem, North Carolina 27157, United States
| | - Tao Ma
- Department of Internal Medicine-Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston Salem, North Carolina 27157, United States
| | - Matthew J Jorgensen
- Department of Comparative Medicine, Wake Forest School of Medicine, Winston Salem, North Carolina 27157, United States
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Bansode AH, Bhoopal B, Gollapelli KK, Damuka N, Krizan I, Miller M, Craft S, Mintz A, Solingapuram Sai KK. Binding Parameters of [ 11C]MPC-6827, a Microtubule-Imaging PET Radiopharmaceutical in Rodents. Pharmaceuticals (Basel) 2023; 16:495. [PMID: 37111252 PMCID: PMC10140836 DOI: 10.3390/ph16040495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 03/18/2023] [Accepted: 03/21/2023] [Indexed: 03/29/2023] Open
Abstract
Impairment and/or destabilization of neuronal microtubules (MTs) resulting from hyper-phosphorylation of the tau proteins is implicated in many pathologies, including Alzheimer's disease (AD), Parkinson's disease and other neurological disorders. Increasing scientific evidence indicates that MT-stabilizing agents protect against the deleterious effects of neurodegeneration in treating AD. To quantify these protective benefits, we developed the first brain-penetrant PET radiopharmaceutical, [11C]MPC-6827, for in vivo quantification of MTs in rodent and nonhuman primate models of AD. Mechanistic insights revealed from recently reported studies confirm the radiopharmaceutical's high selectivity for destabilized MTs. To further translate it to clinical settings, its metabolic stability and pharmacokinetic parameters must be determined. Here, we report in vivo plasma and brain metabolism studies establishing the radiopharmaceutical-binding constants of [11C]MPC-6827. Binding constants were extrapolated from autoradiography experiments; pretreatment with a nonradioactive MPC-6827 decreased the brain uptake >70%. It exhibited ideal binding characteristics (typical of a CNS radiopharmaceutical) including LogP (2.9), Kd (15.59 nM), and Bmax (11.86 fmol/mg). Most important, [11C]MPC-6827 showed high serum and metabolic stability (>95%) in rat plasma and brain samples.
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Affiliation(s)
- Avinash H. Bansode
- Department of Radiology, Wake Forest School of Medicine, Winston Salem, NC 27157, USA
| | | | | | - Naresh Damuka
- Department of Radiology, Wake Forest School of Medicine, Winston Salem, NC 27157, USA
| | - Ivan Krizan
- Department of Radiology, Wake Forest School of Medicine, Winston Salem, NC 27157, USA
| | - Mack Miller
- Department of Radiology, Wake Forest School of Medicine, Winston Salem, NC 27157, USA
| | - Suzanne Craft
- Department of Gerontology, Wake Forest School of Medicine, Winston Salem, NC 27157, USA
| | - Akiva Mintz
- Department of Radiology, Columbia Medical Center, New York, NY 10032, USA
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Maracaja L, Khanna AK, Murphy SV, Maracaja DL, Lane MR, Khoury O, Tan J, Damuka N, Crawford FF, Bottoms JA, Miller MD, Kaczka DW, Jordam JE, Sai KKS. Positron Emission Tomography-Computed Tomography Imaging of Selective Lobar Delivery of Stem Cells in Ex Vivo Lung Model of Mechanical Ventilation. J Aerosol Med Pulm Drug Deliv 2023; 36:20-26. [PMID: 36594924 PMCID: PMC9942179 DOI: 10.1089/jamp.2022.0013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Introduction: The delivery of cell therapies may be an important frontier to treat different respiratory diseases in the near future. However, the cell size, delivery conditions, cell viability, and effect in the pulmonary function are critical factors. We performed a proof-of-concept experiment using ex vivo lungs and novel subglottic airway device that allows for selective lobar isolation and administration of drugs and biologics in liquid solution deep into the lung tissues, while simultaneously ventilating the rest of the lung lobes. Methods: We used radiolabeled cells and positron emission tomography-computed tomography (PET-CT) imaging to demonstrate the feasibility of high-yield cell delivery to a specifically targeted lobe. This study proposes an alternative delivery method of live cells labeled with radioactive isotope into the lung parenchyma and tracks the cell delivery using PET-CT imaging. The technique combines selective lobar isolation and lobar infusion to carry large particles distal to the trachea, subtending bronchial segments and reaching alveoli in targeted regions. Results: The solution with cells and carrier achieved a complete and homogeneous lobar distribution. An increase in tissue density was shown on the computed tomography (CT) scan, and the PET-CT imaging demonstrated retention of the activity at central, peripheral lung parenchyma, and pleural surface. The increase in CT density and metabolic activity of the isotope was restricted to the desired lobe only without leak to other lobes. Conclusion: The selective lobe delivery is targeted and imaging-guided by bronchoscopy and CT to a specific diseased lobe during mechanical ventilation. The feasibility of high-yield cell delivery demonstrated in this study will lead to the development of potential novel therapies that contribute to lung health.
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Affiliation(s)
- Luiz Maracaja
- Department of Anesthesiology, Wake Forest Baptist Medical Center–Wake Forest School of Medicine, Winston-Salem, North Carolina, USA.,Address correspondence to: Luiz Maracaja, MD, Wake Forest Baptist Medical Center, Winston-Salem, NC 27157-0001, USA
| | - Ashish K. Khanna
- Department of Anesthesiology, Wake Forest Baptist Medical Center–Wake Forest School of Medicine, Winston-Salem, North Carolina, USA.,Outcomes Research Consortium, Cleveland, Ohio, USA
| | - Sean V. Murphy
- Wake Forest Institute for Regenerative Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Danielle L.V. Maracaja
- Department of Pathology, Wake Forest Baptist Medical Center–Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Magan R. Lane
- Department of Cardiothoracic Surgery, Wake Forest Baptist Medical Center–Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Oula Khoury
- Wake Forest Institute for Regenerative Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Josh Tan
- Department of Radiology, Wake Forest Baptist Medical Center–Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Naresh Damuka
- Department of Radiology, Wake Forest Baptist Medical Center–Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Freda F. Crawford
- Department of Radiology, Wake Forest Baptist Medical Center–Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Joseph A. Bottoms
- Department of Radiology, Wake Forest Baptist Medical Center–Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Mack D. Miller
- Department of Radiology, Wake Forest Baptist Medical Center–Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - David W. Kaczka
- Department of Anesthesia, The University of Iowa Hospital and Clinics, The University of Iowa, Iowa City, Iowa, USA
| | - James Eric Jordam
- Department of Cardiothoracic Surgery, Wake Forest Baptist Medical Center–Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Kiran Kumar Solingapuram Sai
- Department of Radiology, Wake Forest Baptist Medical Center–Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
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Damuka N, Bashetti N, Mintz A, Bansode AH, Miller M, Krizan I, Furdui C, Bhoopal B, Gollapelli KK, Shanmukha Kumar JV, Deep G, Dugan G, Cline M, Solingapuram Sai KK. [ 18F]KS1, a novel ascorbate-based ligand images ROS in tumor models of rodents and nonhuman primates. Biomed Pharmacother 2022; 156:113937. [PMID: 36411624 PMCID: PMC11017304 DOI: 10.1016/j.biopha.2022.113937] [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: 08/29/2022] [Revised: 10/24/2022] [Accepted: 10/26/2022] [Indexed: 11/20/2022] Open
Abstract
Over production of reactive oxygen species (ROS) caused by altered redox regulation of signaling pathways is common in many types of cancers. While PET imaging is recognized as the standard tool for cancer imaging, there are no clinically-approved PET radiotracers for ROS-imaging in cancer diagnosis and treatment. An ascorbate-based radio ligand promises to meet this urgent need. Our laboratory recently synthesized [18F] KS1, a fluoroethoxy furanose ring-containing ascorbate derivative, to track ROS in prostate tumor-bearing mice. Here we report cell uptake assays of [18F]KS1 with different ROS-regulating agents, PET imaging in head and neck squamous cell carcinoma (HNSCC) mice, and doxorubicin-induced rats; PET imaging in healthy and irradiated hepatic tumor-bearing rhesus to demonstrate its translational potential. Our preliminary evaluations demonstrated that KS1 do not generate ROS in tumor cells at tracer-level concentrations and tumor-killing properties at pharmacologic doses. [18F]KS1 uptake was low in HNSCC pretreated with ROS blockers, and high with ROS inducers. Tumors in high ROS-expressing SCC-61 took up significantly more [18F]KS1 than rSCC-61 (low-ROS expressing HNSCC); high uptake in doxorubicin-treated rats compared to saline-treated controls. Rodent biodistribution and PET imaging of [18F]KS1 in healthy rhesus monkeys demonstrated its favorable safety, pharmacokinetic properties with excellent washout profile, within 3.0 h of radiotracer administration. High uptake of [18F]KS1 in liver tumor tissues of the irradiated hepatic tumor-bearing monkey showed target selectivity. Our strong data in vitro, in vivo, and ex vivo here supports the high translational utility of [18F]KS1 to image ROS.
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Affiliation(s)
- Naresh Damuka
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Nagaraju Bashetti
- Department of Chemistry, Koneru Lakshmaiah Education Foundation, Andhra Pradesh, India
| | - Akiva Mintz
- Department of Radiology, Columbia University, New York, NY, United States
| | - Avinash H Bansode
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Mack Miller
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Ivan Krizan
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Cristina Furdui
- Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Bhuvanachandra Bhoopal
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | | | - J V Shanmukha Kumar
- Department of Chemistry, Koneru Lakshmaiah Education Foundation, Andhra Pradesh, India
| | - Gagan Deep
- Department of Cancer Biology, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Greg Dugan
- Department of Comparative Medicine, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Mark Cline
- Department of Comparative Medicine, Wake Forest School of Medicine, Winston-Salem, NC, United States
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Damuka N, Orr ME, Bansode AH, Krizan I, Miller M, Lee J, Macauley SL, Whitlow CT, Mintz A, Craft S, Solingapuram Sai KK. Preliminary mechanistic insights of a brain-penetrant microtubule imaging PET ligand in a tau-knockout mouse model. EJNMMI Res 2022; 12:41. [PMID: 35881263 PMCID: PMC9325934 DOI: 10.1186/s13550-022-00912-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 06/29/2022] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Microtubules (MTs) are critical for cell structure, function, and survival. MT instability may contribute to Alzheimer's disease (AD) pathogenesis as evidenced by persistent negative regulation (phosphorylation) of the neuronal microtubule-associated protein tau. Hyperphosphorylated tau, not bound to MTs, forms intraneuronal pathology that correlates with dementia and can be tracked using positron emission tomography (PET) imaging. The contribution of MT instability in AD remains unknown, though it may be more proximal to neuronal dysfunction than tau accumulation. Our lab reported the first brain-penetrant MT-based PET ligand, [11C]MPC-6827, and its PET imaging with this ligand in normal rodents and non-human primates demonstrated high brain uptake and excellent pharmacokinetics. Target engagement and mechanism of action using in vitro, in vivo, and ex vivo methods were evaluated here. METHODS In vitro cell uptake assay was performed in SH-SY5Y neuronal cells with [11C]MPC-6827, with various MT stabilizing and destabilizing agents. To validate the in vitro results, wild type (WT) mice (n = 4) treated with a brain-penetrant MT stabilizing drug (EpoD) underwent microPET/CT brain imaging with [11C]MPC-6827. To determine the influence of tau protein on radiotracer binding in the absence of protein accumulation, we utilized tau knockout (KO) mice. In vivo microPET imaging, ex vivo biodistribution, and autoradiography studies were performed in tau KO and WT mice (n = 6/group) with [11C]MPC-6827. Additionally, α, β, and acetylated tubulin levels in both brain samples were determined using commercially available cytoskeleton-based MT kit and capillary electrophoresis immunoblotting assays. RESULTS Cell uptake demonstrated higher radioactive uptake with MT destabilizing agents and lower uptake with stabilizing agents compared to untreated cells. Similarly, acute treatment with EpoD in WT mice decreased [11C]MPC-6827 brain uptake, assessed with microPET/CT imaging. Compared to WT mice, tau KO mice expressed significantly lower β tubulin, which contains the MPC-6827 binding domain, and modestly lower levels of acetylated α tubulin, indicative of unstable MTs. In vivo imaging revealed significantly higher [11C]MPC-6827 uptake in tau KOs than WT, particularly in AD-relevant brain regions known to express high levels of tau. Ex vivo post-PET biodistribution and autoradiography confirmed the in vivo results. CONCLUSIONS Collectively, our data indicate that [11C]MPC-6827 uptake inversely correlates with MT stability and may better reflect the absence of tau than total tubulin levels. Given the radiotracer binding does not require the presence of aggregated tau, we hypothesize that [11C]MPC-6827 may be particularly useful in preclinical stages of AD prior to tau deposition. Our study provides immediate clarity on high uptake of the MT-based radiotracer in AD brains, which directly informs clinical utility in MT/tau-based PET imaging studies.
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Affiliation(s)
- Naresh Damuka
- Department of Radiology, Wake Forest School of Medicine, Winston Salem, NC 27157 USA
| | - Miranda E. Orr
- Department of Gerontology, Wake Forest School of Medicine, Winston Salem, NC 27157 USA
| | - Avinash H. Bansode
- Department of Radiology, Wake Forest School of Medicine, Winston Salem, NC 27157 USA
| | - Ivan Krizan
- Department of Radiology, Wake Forest School of Medicine, Winston Salem, NC 27157 USA
| | - Mack Miller
- Department of Radiology, Wake Forest School of Medicine, Winston Salem, NC 27157 USA
| | - Jillian Lee
- Department of Gerontology, Wake Forest School of Medicine, Winston Salem, NC 27157 USA
| | - Shannon L. Macauley
- Department of Gerontology, Wake Forest School of Medicine, Winston Salem, NC 27157 USA
| | | | - Akiva Mintz
- Department of Radiology, Columbia Medical Center, New York, NY 10032 USA
| | - Suzanne Craft
- Department of Gerontology, Wake Forest School of Medicine, Winston Salem, NC 27157 USA
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Damuka N, Martin TJ, Bansode AH, Krizan I, Martin CW, Miller M, Whitlow CT, Nader MA, Solingapuram Sai KK. Initial Evaluations of the Microtubule-Based PET Radiotracer, [11C]MPC-6827 in a Rodent Model of Cocaine Abuse. Front Med (Lausanne) 2022; 9:817274. [PMID: 35295607 PMCID: PMC8918945 DOI: 10.3389/fmed.2022.817274] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 02/07/2022] [Indexed: 11/13/2022] Open
Abstract
PurposeMicrotubules (MTs) are structural units made of α and β tubulin subunits in the cytoskeleton responsible for axonal transport, information processing, and signaling mechanisms—critical for healthy brain function. Chronic cocaine exposure affects the function, organization, and stability of MTs in the brain, thereby impairing overall neurochemical and cognitive processes. At present, we have no reliable, non-invasive methods to image MTs for cocaine use disorder (CUD). Recently we reported the effect of cocaine in patient-derived neuroblastoma SH-SY5Y cells. Here we report preliminary results of a potential imaging biomarker of CUD using the brain penetrant MT-based radiotracer, [11C]MPC-6827, in an established rodent model of cocaine self-administration (SA).MethodsCell uptake studies were performed with [11C]MPC-6827 in SH-SY5Y cells, treated with or without cocaine (n = 6/group) at 30 and 60 min incubations. MicroPET/CT brain scans were performed in rats at baseline and 35 days after cocaine self-administration and compared with saline-treated rats as controls (n = 4/sex). Whole-body post-PET biodistribution, plasma metabolite assay, and brain autoradiography were performed in the same rats from imaging.ResultsCocaine-treated SH-SY5Y cells demonstrated a ∼26(±4)% decrease in radioactive uptake compared to non-treated controls. Both microPET/CT imaging and biodistribution results showed lower (∼35 ± 3%) [11C]MPC-6827 brain uptake in rats that had a history of cocaine self-administration compared to the saline-treated controls. Plasma metabolite assays demonstrate the stability (≥95%) of the radiotracer in both groups. In vitro autoradiography also demonstrated lower radioactive uptake in cocaine rats compared to the control rats. [11C]MPC-6827’s in vitro SH-SY5Y neuronal cell uptake, in vivo positron emission tomography (PET) imaging, ex vivo biodistribution, and in vitro autoradiography results corroborated well with each other, demonstrating decreased radioactive brain uptake in cocaine self-administered rats versus controls. There were no significant differences either in cocaine intake or in [11C]MPC-6827 uptake between the male and female rats.ConclusionsThis project is the first to validate in vivo imaging of the MT-associations with CUD in a rodent model. Our initial observations suggest that [11C]MPC-6827 uptake decreases in cocaine self-administered rats and that it may selectively bind to destabilized tubulin units in the brain. Further longitudinal studies correlating cocaine intake with [11C]MPC-6827 PET brain measures could potentially establish the MT scaffold as an imaging biomarker for CUD, providing researchers and clinicians with a sensitive tool to better understand the biological underpinnings of CUD and tailor new treatments.
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Affiliation(s)
- Naresh Damuka
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Thomas J. Martin
- Department of Anesthesiology, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Avinash H. Bansode
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Ivan Krizan
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Conner W. Martin
- Department of Anesthesiology, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Mack Miller
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Christopher T. Whitlow
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Michael A. Nader
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Kiran Kumar Solingapuram Sai
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC, United States
- *Correspondence: Kiran Kumar Solingapuram Sai,
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