1
|
Bork PAR, Hauglund NL, Mori Y, Møllgård K, Hjorth PG, Nedergaard M. Modeling of brain efflux: Constraints of brain surfaces. Proc Natl Acad Sci U S A 2024; 121:e2318444121. [PMID: 38598340 PMCID: PMC11032467 DOI: 10.1073/pnas.2318444121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 03/04/2024] [Indexed: 04/12/2024] Open
Abstract
Fluid efflux from the brain plays an important role in solute waste clearance. Current experimental approaches provide little spatial information, and data collection is limited due to short duration or low frequency of sampling. One approach shows tracer efflux to be independent of molecular size, indicating bulk flow, yet also decelerating like simple membrane diffusion. In an apparent contradiction to this report, other studies point to tracer efflux acceleration. We here develop a one-dimensional advection-diffusion model to gain insight into brain efflux principles. The model is characterized by nine physiological constants and three efflux parameters for which we quantify prior uncertainty. Using Bayes' rule and the two efflux studies, we validate the model and calculate data-informed parameter distributions. The apparent contradictions in the efflux studies are resolved by brain surface boundaries being bottlenecks for efflux. To critically test the model, a custom MRI efflux assay measuring solute dispersion in tissue and release to cerebrospinal fluid was employed. The model passed the test with tissue bulk flow velocities in the range 60 to 190 [Formula: see text]m/h. Dimensional analysis identified three principal determinants of efflux, highlighting brain surfaces as a restricting factor for metabolite solute clearance.
Collapse
Affiliation(s)
- Peter A. R. Bork
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen2200Denmark
| | - Natalie L. Hauglund
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen2200Denmark
| | - Yuki Mori
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen2200Denmark
| | - Kjeld Møllgård
- Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen2200Denmark
| | - Poul G. Hjorth
- Department of Applied Mathematics and Computer Science, Technical University of Denmark, Lyngby2800Denmark
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen2200Denmark
| |
Collapse
|
2
|
Sigurdsson B, Hauglund NL, Lilius TO, Mogensen FLH, Mortensen KN, Beschorner N, Klinger L, Bærentzen SL, Rosenholm MP, Shalgunov V, Herth M, Mori Y, Nedergaard M. A SPECT-based method for dynamic imaging of the glymphatic system in rats. J Cereb Blood Flow Metab 2023; 43:1153-1165. [PMID: 36809165 PMCID: PMC10291457 DOI: 10.1177/0271678x231156982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 11/17/2022] [Accepted: 12/07/2022] [Indexed: 02/23/2023]
Abstract
The glymphatic system is a brain-wide waste drainage system that promotes cerebrospinal fluid circulation through the brain to remove waste metabolites. Currently, the most common methods for assessing glymphatic function are ex vivo fluorescence microscopy of brain slices, macroscopic cortical imaging, and MRI. While all these methods have been crucial for expanding our understanding of the glymphatic system, new techniques are required to overcome their specific drawbacks. Here, we evaluate SPECT/CT imaging as a tool to assess glymphatic function in different anesthesia-induced brain states using two radiolabeled tracers, [111In]-DTPA and [99mTc]-NanoScan. Using SPECT, we confirmed the existence of brain state-dependent differences in glymphatic flow and we show brain state-dependent differences of CSF flow kinetics and CSF egress to the lymph nodes. We compare SPECT and MRI for imaging glymphatic flow and find that the two imaging modalities show the same overall pattern of CSF flow, but that SPECT was specific across a greater range of tracer concentrations than MRI. Overall, we find that SPECT imaging is a promising tool for imaging the glymphatic system, and that qualities such as high sensitivity and the variety of available tracers make SPECT imaging a good alternative for glymphatic research.
Collapse
Affiliation(s)
- Björn Sigurdsson
- Center for Translational Neuromedicine, University of Copenhagen, Denmark
| | - Natalie L Hauglund
- Center for Translational Neuromedicine, University of Copenhagen, Denmark
| | - Tuomas O Lilius
- Center for Translational Neuromedicine, University of Copenhagen, Denmark
- INDIVIDRUG Research Program, University of Helsinki, Finland
- Department of Pharmacology, University of Helsinki, Finland
- Department of Emergency Medicine and Services, Helsinki University Hospital and University of Helsinki, Finland
| | - Frida L-H Mogensen
- Center for Translational Neuromedicine, University of Copenhagen, Denmark
- Neuro-Immunology Group, Department of Cancer Research, Luxembourg Institute of Health, Luxembourg, Luxembourg
- Doctoral School of Science and Technology, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | | | - Natalie Beschorner
- Center for Translational Neuromedicine, University of Copenhagen, Denmark
| | - Laura Klinger
- Center for Translational Neuromedicine, University of Copenhagen, Denmark
| | - Simone L Bærentzen
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Nuclear Medicine and PET Center, Aarhus University Hospital, Aarhus, Denmark
| | - Marko P Rosenholm
- Center for Translational Neuromedicine, University of Copenhagen, Denmark
| | - Vladimir Shalgunov
- Department of Drug Design and Pharmacology, University of Copenhagen, Denmark
| | - Matthias Herth
- Department of Drug Design and Pharmacology, University of Copenhagen, Denmark
- Department of Clinical Physiology, Copenhagen University Hospital, Denmark
| | - Yuki Mori
- Center for Translational Neuromedicine, University of Copenhagen, Denmark
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, University of Copenhagen, Denmark
- Center for Translational Neuromedicine, University of Rochester Medical Center, USA
| |
Collapse
|
3
|
Mathiesen BK, Miyakoshi LM, Cederroth CR, Tserga E, Versteegh C, Bork PAR, Hauglund NL, Gomolka RS, Mori Y, Edvall NK, Rouse S, Møllgård K, Holt JR, Nedergaard M, Canlon B. Delivery of gene therapy through a cerebrospinal fluid conduit to rescue hearing in adult mice. Sci Transl Med 2023; 15:eabq3916. [PMID: 37379370 DOI: 10.1126/scitranslmed.abq3916] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 06/09/2023] [Indexed: 06/30/2023]
Abstract
Inner ear gene therapy has recently effectively restored hearing in neonatal mice, but it is complicated in adulthood by the structural inaccessibility of the cochlea, which is embedded within the temporal bone. Alternative delivery routes may advance auditory research and also prove useful when translated to humans with progressive genetic-mediated hearing loss. Cerebrospinal fluid flow via the glymphatic system is emerging as a new approach for brain-wide drug delivery in rodents as well as humans. The cerebrospinal fluid and the fluid of the inner ear are connected via a bony channel called the cochlear aqueduct, but previous studies have not explored the possibility of delivering gene therapy via the cerebrospinal fluid to restore hearing in adult deaf mice. Here, we showed that the cochlear aqueduct in mice exhibits lymphatic-like characteristics. In vivo time-lapse magnetic resonance imaging, computed tomography, and optical fluorescence microscopy showed that large-particle tracers injected into the cerebrospinal fluid reached the inner ear by dispersive transport via the cochlear aqueduct in adult mice. A single intracisternal injection of adeno-associated virus carrying solute carrier family 17, member 8 (Slc17A8), which encodes vesicular glutamate transporter-3 (VGLUT3), rescued hearing in adult deaf Slc17A8-/- mice by restoring VGLUT3 protein expression in inner hair cells, with minimal ectopic expression in the brain and none in the liver. Our findings demonstrate that cerebrospinal fluid transport comprises an accessible route for gene delivery to the adult inner ear and may represent an important step toward using gene therapy to restore hearing in humans.
Collapse
Affiliation(s)
- Barbara K Mathiesen
- Center for Translational Neuromedicine, Division of Glial Disease and Therapeutics, Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Denmark
| | - Leo M Miyakoshi
- Center for Translational Neuromedicine, Division of Glial Disease and Therapeutics, Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Denmark
| | - Christopher R Cederroth
- Department of Physiology and Pharmacology, Karolinska Institutet, Solnavägen 9, Biomedicum, 171 65 Stockholm, Sweden
- Translational Hearing Research, Tübingen Hearing Research Center, Department of Otolaryngology, Head and Neck Surgery, University of Tübingen, Tübingen, Germany
| | - Evangelia Tserga
- Department of Physiology and Pharmacology, Karolinska Institutet, Solnavägen 9, Biomedicum, 171 65 Stockholm, Sweden
| | - Corstiaen Versteegh
- Department of Physiology and Pharmacology, Karolinska Institutet, Solnavägen 9, Biomedicum, 171 65 Stockholm, Sweden
| | - Peter A R Bork
- Center for Translational Neuromedicine, Division of Glial Disease and Therapeutics, Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Denmark
| | - Natalie L Hauglund
- Center for Translational Neuromedicine, Division of Glial Disease and Therapeutics, Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Denmark
| | - Ryszard Stefan Gomolka
- Center for Translational Neuromedicine, Division of Glial Disease and Therapeutics, Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Denmark
| | - Yuki Mori
- Center for Translational Neuromedicine, Division of Glial Disease and Therapeutics, Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Denmark
| | - Niklas K Edvall
- Department of Physiology and Pharmacology, Karolinska Institutet, Solnavägen 9, Biomedicum, 171 65 Stockholm, Sweden
| | - Stephanie Rouse
- Department of Otolaryngology and Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Kjeld Møllgård
- Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen; Copenhagen, 2200, Denmark
| | - Jeffrey R Holt
- Department of Otolaryngology and Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, Division of Glial Disease and Therapeutics, Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Denmark
- Center for Translational Neuromedicine, Division of Glial Disease and Therapeutics, University of Rochester Medical Center; Rochester, NY 14642, USA
| | - Barbara Canlon
- Department of Physiology and Pharmacology, Karolinska Institutet, Solnavägen 9, Biomedicum, 171 65 Stockholm, Sweden
| |
Collapse
|
4
|
Møllgård K, Beinlich FRM, Kusk P, Miyakoshi LM, Delle C, Plá V, Hauglund NL, Esmail T, Rasmussen MK, Gomolka RS, Mori Y, Nedergaard M. A mesothelium divides the subarachnoid space into functional compartments. Science 2023; 379:84-88. [PMID: 36603070 DOI: 10.1126/science.adc8810] [Citation(s) in RCA: 65] [Impact Index Per Article: 65.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The central nervous system is lined by meninges, classically known as dura, arachnoid, and pia mater. We show the existence of a fourth meningeal layer that compartmentalizes the subarachnoid space in the mouse and human brain, designated the subarachnoid lymphatic-like membrane (SLYM). SLYM is morpho- and immunophenotypically similar to the mesothelial membrane lining of peripheral organs and body cavities, and it encases blood vessels and harbors immune cells. Functionally, the close apposition of SLYM with the endothelial lining of the meningeal venous sinus permits direct exchange of small solutes between cerebrospinal fluid and venous blood, thus representing the mouse equivalent of the arachnoid granulations. The functional characterization of SLYM provides fundamental insights into brain immune barriers and fluid transport.
Collapse
Affiliation(s)
- Kjeld Møllgård
- Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Felix R M Beinlich
- Division of Glial Disease and Therapeutics, Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Peter Kusk
- Division of Glial Disease and Therapeutics, Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Leo M Miyakoshi
- Division of Glial Disease and Therapeutics, Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Christine Delle
- Division of Glial Disease and Therapeutics, Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Virginia Plá
- Division of Glial Disease and Therapeutics, Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Natalie L Hauglund
- Division of Glial Disease and Therapeutics, Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Tina Esmail
- Division of Glial Disease and Therapeutics, Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Martin K Rasmussen
- Division of Glial Disease and Therapeutics, Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Ryszard S Gomolka
- Division of Glial Disease and Therapeutics, Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Yuki Mori
- Division of Glial Disease and Therapeutics, Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Maiken Nedergaard
- Division of Glial Disease and Therapeutics, Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY 14642, USA
| |
Collapse
|
5
|
Lilius TO, Rosenholm M, Klinger L, Mortensen KN, Sigurdsson B, Mogensen FLH, Hauglund NL, Nielsen MSN, Rantamäki T, Nedergaard M. SPECT/CT imaging reveals CNS-wide modulation of glymphatic cerebrospinal fluid flow by systemic hypertonic saline. iScience 2022; 25:105250. [PMID: 36274948 PMCID: PMC9579504 DOI: 10.1016/j.isci.2022.105250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 09/04/2022] [Accepted: 09/27/2022] [Indexed: 11/18/2022] Open
Abstract
Intrathecal administration enables central nervous system delivery of drugs that do not bypass the blood-brain barrier. Systemic administration of hypertonic saline (HTS) enhances delivery of intrathecal therapeutics into the neuropil, but its effect on solute clearance from the brain remains unknown. Here, we developed a dynamic in vivo single-photon emission computed tomography (SPECT)/computed tomography (CT) imaging platform to study the effects of HTS on whole-body distribution of the radiolabeled tracer 99mTc-diethylenetriaminepentaacetic acid (DTPA) administered through intracisternal, intrastriatal, or intravenous route in anesthetized rats. Co-administration of systemic HTS increased intracranial exposure to intracisternal 99mTc-DTPA by ∼80% during imaging. In contrast, HTS had minimal effects on brain clearance of intrastriatal 99mTc-DTPA. In sum, SPECT/CT imaging presents a valuable approach to study glymphatic drug delivery. Using this methodology, we show that systemic HTS increases intracranial availability of cerebrospinal fluid-administered tracer, but has marginal effects on brain clearance, thus substantiating a simple, yet effective strategy for enhancing intrathecal drug delivery to the brain. We established a SPECT/CT platform for imaging glymphatic drug delivery in vivo Hypertonic saline (HTS) elevates intracranial availability of CSF-infused 99mTc-DTPA HTS triples the availability of 99mTc-DTPA in several deep brain regions HTS has negligible effects on clearance of intrastriatally infused DTPA
Collapse
Affiliation(s)
- Tuomas O. Lilius
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Individualized Drug Therapy Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Department of Emergency Medicine and Services, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Marko Rosenholm
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Individualized Drug Therapy Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Laura Klinger
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Kristian Nygaard Mortensen
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Björn Sigurdsson
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Frida Lind-Holm Mogensen
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Neuro-immunology Group, Department of Cancer Research, Luxembourg Institute of Health, Luxembourg, Luxembourg
- Doctoral School of Science and Technology, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Natalie L. Hauglund
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Tomi Rantamäki
- Laboratory of Neurotherapeutics, Doctoral Program in Drug Research, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
- SleepWell Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Center for Translational Neuromedicine, Department of Neurosurgery, University of Rochester Medical Center, 601 Elmwood Avenue, Box 645, Rochester, NY 14642, USA
- Corresponding author
| |
Collapse
|
6
|
Monai H, Koketsu S, Shinohara Y, Ueki T, Kusk P, Hauglund NL, Samson AJ, Nedergaard M, Hirase H. Author Correction: Adrenergic inhibition facilitates normalization of extracellular potassium after cortical spreading depolarization. Sci Rep 2022; 12:4741. [PMID: 35304562 PMCID: PMC8933480 DOI: 10.1038/s41598-022-08615-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Affiliation(s)
- Hiromu Monai
- Laboratory for Neuron-Glia Circuitry, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan. .,Faculty of Core Research Natural Science Division, Ochanomizu University, Bunkyo-Ku, Tokyo, 112-8610, Japan.
| | - Shinnosuke Koketsu
- Department of Integrative Anatomy, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, 467-8601, Japan
| | - Yoshiaki Shinohara
- Department of Integrative Anatomy, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, 467-8601, Japan.,Division of Histology and Cell Biology, Department of Anatomy, Jichi Medical University, Shimotsuke, Tochigi, 329-0498, Japan
| | - Takatoshi Ueki
- Department of Integrative Anatomy, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, 467-8601, Japan
| | - Peter Kusk
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Natalie L Hauglund
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Andrew J Samson
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark.,Center for Translational Neuromedicine, University of Rochester Medical Center, Elmwood Avenue 601, Rochester, NY, 14642, USA
| | - Hajime Hirase
- Laboratory for Neuron-Glia Circuitry, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan. .,Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark.
| |
Collapse
|
7
|
Hauglund NL, Pavan C, Nedergaard M. Cleaning the sleeping brain – the potential restorative function of the glymphatic system. Current Opinion in Physiology 2020. [DOI: 10.1016/j.cophys.2019.10.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
8
|
Lilius TO, Blomqvist K, Hauglund NL, Liu G, Stæger FF, Bærentzen S, Du T, Ahlström F, Backman JT, Kalso EA, Rauhala PV, Nedergaard M. Dexmedetomidine enhances glymphatic brain delivery of intrathecally administered drugs. J Control Release 2019; 304:29-38. [PMID: 31067483 DOI: 10.1016/j.jconrel.2019.05.005] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 04/28/2019] [Accepted: 05/03/2019] [Indexed: 11/30/2022]
Abstract
Drug delivery to the central nervous system remains a major problem due to biological barriers. The blood-brain-barrier can be bypassed by administering drugs intrathecally directly to the cerebrospinal fluid (CSF). The glymphatic system, a network of perivascular spaces promoting fluid exchange between CSF and interstitial space, could be utilized to enhance convective drug delivery from the CSF to the parenchyma. Glymphatic flow is highest during sleep and anesthesia regimens that induce a slow-wave sleep-like state. Here, using mass spectrometry and fluorescent imaging techniques, we show that the clinically used α2-adrenergic agonist dexmedetomidine that enhances EEG slow-wave activity, increases brain and spinal cord drug exposure of intrathecally administered drugs in mice and rats. Using oxycodone, naloxone, and an IgG-sized antibody as relevant model drugs we demonstrate that modulation of glymphatic flow has a distinct impact on the distribution of intrathecally administered therapeutics. These findings can be exploited in the clinic to improve the efficacy and safety of intrathecally administered therapeutics.
Collapse
Affiliation(s)
- Tuomas O Lilius
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland; Department of Clinical Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki University Hospital, Helsinki, Finland; Individualized Drug Therapy Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
| | - Kim Blomqvist
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland; Individualized Drug Therapy Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Natalie L Hauglund
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Guojun Liu
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, USA
| | - Frederik Filip Stæger
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Simone Bærentzen
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ting Du
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, USA
| | - Fredrik Ahlström
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland; Individualized Drug Therapy Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Janne T Backman
- Department of Clinical Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki University Hospital, Helsinki, Finland; Individualized Drug Therapy Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Eija A Kalso
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland; Department of Anaesthesiology, Intensive Care Medicine, and Pain Medicine, Helsinki University Hospital, University of Helsinki, Finland
| | - Pekka V Rauhala
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland; Individualized Drug Therapy Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, USA
| |
Collapse
|