1
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Leinenga G, To XV, Bodea LG, Yousef J, Richter-Stretton G, Palliyaguru T, Chicoteau A, Dagley L, Nasrallah F, Götz J. Scanning ultrasound-mediated memory and functional improvements do not require amyloid-β reduction. Mol Psychiatry 2024:10.1038/s41380-024-02509-5. [PMID: 38499653 DOI: 10.1038/s41380-024-02509-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 02/27/2024] [Accepted: 02/29/2024] [Indexed: 03/20/2024]
Abstract
A prevalent view in treating age-dependent disorders including Alzheimer's disease (AD) is that the underlying amyloid plaque pathology must be targeted for cognitive improvements. In contrast, we report here that repeated scanning ultrasound (SUS) treatment at 1 MHz frequency can ameliorate memory deficits in the APP23 mouse model of AD without reducing amyloid-β (Aβ) burden. Different from previous studies that had shown Aβ clearance as a consequence of blood-brain barrier (BBB) opening, here, the BBB was not opened as no microbubbles were used. Quantitative SWATH proteomics and functional magnetic resonance imaging revealed that ultrasound induced long-lasting functional changes that correlate with the improvement in memory. Intriguingly, the treatment was more effective at a higher frequency (1 MHz) than at a frequency within the range currently explored in clinical trials in AD patients (286 kHz). Together, our data suggest frequency-dependent bio-effects of ultrasound and a dissociation of cognitive improvement and Aβ clearance, with important implications for the design of trials for AD therapies.
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Affiliation(s)
- Gerhard Leinenga
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Xuan Vinh To
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
- Centre for Advanced Imaging, The University of Queensland, Brisbane, QLD, Australia
| | - Liviu-Gabriel Bodea
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Jumana Yousef
- Proteomics Facility, Advanced Technology and Biology Division, The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3052, Australia
| | - Gina Richter-Stretton
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Tishila Palliyaguru
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Antony Chicoteau
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Laura Dagley
- Proteomics Facility, Advanced Technology and Biology Division, The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3052, Australia
| | - Fatima Nasrallah
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
- Centre for Advanced Imaging, The University of Queensland, Brisbane, QLD, Australia
| | - Jürgen Götz
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia.
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2
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Fisher DG, Sharifi KA, Shah IM, Gorick CM, Breza VR, Debski AC, Hoch MR, Cruz T, Samuels JD, Sheehan JP, Schlesinger D, Moore D, Lukens JR, Miller GW, Tvrdik P, Price RJ. Focused Ultrasound Blood-Brain Barrier Opening Arrests the Growth and Formation of Cerebral Cavernous Malformations. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.31.577810. [PMID: 38352349 PMCID: PMC10862920 DOI: 10.1101/2024.01.31.577810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/24/2024]
Abstract
BACKGROUND Cerebral cavernous malformations (CCM) are vascular lesions within the central nervous system, consisting of dilated and hemorrhage-prone capillaries. CCMs can cause debilitating neurological symptoms, and surgical excision or stereotactic radiosurgery are the only current treatment options. Meanwhile, transient blood-brain barrier opening (BBBO) with focused ultrasound (FUS) and microbubbles is now understood to exert potentially beneficial bioeffects, such as stimulation of neurogenesis and clearance of amyloid-β. Here, we tested whether FUS BBBO could be deployed therapeutically to control CCM formation and progression in a clinically-representative murine model. METHODS CCMs were induced in mice by postnatal, endothelial-specific Krit1 ablation. FUS was applied for BBBO with fixed peak-negative pressures (PNPs; 0.2-0.6 MPa) or passive cavitation detection-modulated PNPs. Magnetic resonance imaging (MRI) was used to target FUS treatments, evaluate safety, and measure longitudinal changes in CCM growth after BBBO. RESULTS FUS BBBO elicited gadolinium accumulation primarily at the perilesional boundaries of CCMs, rather than lesion cores. Passive cavitation detection and gadolinium contrast enhancement were comparable in CCM and wild-type mice, indicating that Krit1 ablation does not confer differential sensitivity to FUS BBBO. Acutely, CCMs exposed to FUS BBBO remained structurally stable, with no signs of hemorrhage. Longitudinal MRI revealed that FUS BBBO halted the growth of 94% of CCMs treated in the study. At 1 month, FUS BBBO-treated lesions lost, on average, 9% of their pre-sonication volume. In contrast, non-sonicated control lesions grew to 670% of their initial volume. Lesion control with FUS BBBO was accompanied by a marked reduction in the area and mesenchymal appearance of Krit mutant endothelium. Strikingly, in mice receiving multiple BBBO treatments with fixed PNPs, de novo CCM formation was significantly reduced by 81%. Mock treatment plans on MRIs of patients with surgically inaccessible lesions revealed their lesions are amenable to FUS BBBO with current clinical technology. CONCLUSIONS Our results establish FUS BBBO as a novel, non-invasive modality that can safely arrest murine CCM growth and prevent their de novo formation. As an incisionless, MR image-guided therapy with the ability to target eloquent brain locations, FUS BBBO offers an unparalleled potential to revolutionize the therapeutic experience and enhance the accessibility of treatments for CCM patients.
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Affiliation(s)
- Delaney G Fisher
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA
| | - Khadijeh A Sharifi
- Department of Neuroscience, University of Virginia, Charlottesville, VA
- Department of Neurological Surgery, University of Virginia Health System, Charlottesville, VA
| | - Ishaan M Shah
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA
| | - Catherine M Gorick
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA
| | - Victoria R Breza
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA
| | - Anna C Debski
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA
| | - Matthew R Hoch
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA
| | - Tanya Cruz
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA
| | - Joshua D Samuels
- Department of Neuroscience, University of Virginia, Charlottesville, VA
| | - Jason P Sheehan
- Department of Neurological Surgery, University of Virginia Health System, Charlottesville, VA
| | - David Schlesinger
- Department of Radiation Oncology, University of Virginia Health System, Charlottesville, VA
| | - David Moore
- Focused Ultrasound Foundation, Charlottesville, VA
| | - John R Lukens
- Department of Neuroscience, University of Virginia, Charlottesville, VA
| | - G Wilson Miller
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA
- Department of Radiology & Medical Imaging, University of Virginia, Charlottesville, VA
| | - Petr Tvrdik
- Department of Neuroscience, University of Virginia, Charlottesville, VA
- Department of Neurological Surgery, University of Virginia Health System, Charlottesville, VA
| | - Richard J Price
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA
- Department of Radiology & Medical Imaging, University of Virginia, Charlottesville, VA
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3
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Ma X, Li T, Du L, Han T. Research and progress of focused ultrasound in the treatment of Alzheimer's disease. Front Neurol 2023; 14:1323386. [PMID: 38187144 PMCID: PMC10771294 DOI: 10.3389/fneur.2023.1323386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 11/30/2023] [Indexed: 01/09/2024] Open
Abstract
Alzheimer's disease is one of the most common degenerative diseases of the central nervous system, with progressive cognitive and memory impairment and decreased ability of daily life as the cardinal symptoms, influencing the life quality of patients severely. There are currently approximately 46 million people living with Alzheimer's disease worldwide, and the number is expected to triple by 2050, which will pose a huge challenge for healthcare. At present, the Food and Drug Administration of the United States has approved five main drugs for the clinical treatment of Alzheimer's disease, which are cholinesterase inhibitors tacrine, galantamine, capalatine and donepezil, and N-methyl-d-aspartate receptor antagonist memantine, although these drugs have shown good efficacy in clinical trials, the actual clinical effect is less effective due to the existence of blood brain barrier. With the continuous development of ultrasound technology in recent years, focused ultrasound, as a non-invasive treatment technique, may target ultrasound energy to the deep brain for treatment without damaging the surrounding tissue. For the past few years, some studies could use focused ultrasound combined with microvesicles to induce blood brain barrier opening and targeted drug delivery to treat Alzheimer's disease, providing new opportunities for the treatment of Alzheimer's disease. This article reviews the application research and progress of focused ultrasound in the treatment of Alzheimer's disease, in order to provide new directions and ideas for the treatment of Alzheimer's disease.
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Affiliation(s)
- Xishun Ma
- Department of Ultrasound, Qingdao Hospital, University of Health and Rehabilitation Sciences (Qingdao Municipal Hospital), Qingdao, China
| | - Tongxia Li
- Department of Tuberculosis, Qingdao Chest Hospital, Qingdao, China
| | - Lizhen Du
- Department of Ultrasound, Qingdao Hospital, University of Health and Rehabilitation Sciences (Qingdao Municipal Hospital), Qingdao, China
| | - Tongliang Han
- Department of Ultrasound, Qingdao Hospital, University of Health and Rehabilitation Sciences (Qingdao Municipal Hospital), Qingdao, China
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4
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Grewal S, Gonçalves de Andrade E, Kofoed RH, Matthews PM, Aubert I, Tremblay MÈ, Morse SV. Using focused ultrasound to modulate microglial structure and function. Front Cell Neurosci 2023; 17:1290628. [PMID: 38164436 PMCID: PMC10757935 DOI: 10.3389/fncel.2023.1290628] [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] [Received: 09/07/2023] [Accepted: 10/31/2023] [Indexed: 01/03/2024] Open
Abstract
Transcranial focused ultrasound (FUS) has the unique ability to target regions of the brain with high spatial precision, in a minimally invasive manner. Neuromodulation studies have shown that FUS can excite or inhibit neuronal activity, demonstrating its tremendous potential to improve the outcome of neurological diseases. Recent evidence has also shed light on the emerging promise that FUS has, with and without the use of intravenously injected microbubbles, in modulating the blood-brain barrier and the immune cells of the brain. As the resident immune cells of the central nervous system, microglia are at the forefront of the brain's maintenance and immune defense. Notably, microglia are highly dynamic and continuously survey the brain parenchyma by extending and retracting their processes. This surveillance activity aids microglia in performing key physiological functions required for brain activity and plasticity. In response to stressors, microglia rapidly alter their cellular and molecular profile to help facilitate a return to homeostasis. While the underlying mechanisms by which both FUS and FUS + microbubbles modify microglial structure and function remain largely unknown, several studies in adult mice have reported changes in the expression of the microglia/macrophage marker ionized calcium binding adaptor molecule 1, and in their phagocytosis, notably of protein aggregates, such as amyloid beta. In this review, we discuss the demonstrated and putative biological effects of FUS and FUS + microbubbles in modulating microglial activities, with an emphasis on the key cellular and molecular changes observed in vitro and in vivo across models of brain health and disease. Understanding how this innovative technology can modulate microglia paves the way for future therapeutic strategies aimed to promote beneficial physiological microglial roles, and prevent or treat maladaptive responses.
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Affiliation(s)
- Sarina Grewal
- Department of Bioengineering, Imperial College London, London, United Kingdom
- Department of Brain Sciences, Imperial College London, London, United Kingdom
| | - Elisa Gonçalves de Andrade
- Neuroscience Graduate Program, Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Rikke Hahn Kofoed
- Department of Neurosurgery, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Center for Experimental Neuroscience-CENSE, Department of Neurosurgery, Aarhus University Hospital, Aarhus, Denmark
- Hurvitz Brain Sciences Research Program, Biological Sciences, Sunnybrook Research Institute, Toronto, ON, Canada
| | - Paul M. Matthews
- Department of Brain Sciences, Imperial College London, London, United Kingdom
- UK Dementia Research Institute, Imperial College London, London, United Kingdom
| | - Isabelle Aubert
- Hurvitz Brain Sciences Research Program, Biological Sciences, Sunnybrook Research Institute, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Marie-Ève Tremblay
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Axe Neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec, QC, Canada
- Department of Molecular Medicine, Université Laval, Québec, QC, Canada
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
| | - Sophie V. Morse
- Department of Bioengineering, Imperial College London, London, United Kingdom
- UK Dementia Research Institute, Imperial College London, London, United Kingdom
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5
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Kong C, Ahn JW, Kim S, Park JY, Na YC, Chang JW, Chung S, Chang WS. Long-lasting restoration of memory function and hippocampal synaptic plasticity by focused ultrasound in Alzheimer's disease. Brain Stimul 2023; 16:857-866. [PMID: 37211337 DOI: 10.1016/j.brs.2023.05.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 05/06/2023] [Accepted: 05/17/2023] [Indexed: 05/23/2023] Open
Abstract
BACKGROUND Focused ultrasound (FUS) is a medical technology that non-invasively stimulates the brain and has been applied in thermal ablation, blood-brain barrier (BBB) opening, and neuromodulation. In recent years, numerous experiences and indications for the use of FUS in clinical and preclinical studies have rapidly expanded. Focused ultrasound-mediated BBB opening induces cognitive enhancement and neurogenesis; however, the underlying mechanisms have not been elucidated. METHODS Here, we investigate the effects of FUS-mediated BBB opening on hippocampal long-term potentiation (LTP) and cognitive function in a 5xFAD mouse model of Alzheimer's disease (AD). We applied FUS with microbubble to the hippocampus and LTP was measured 6 weeks after BBB opening using FUS. Field recordings were made with a concentric bipolar electrode positioned in the CA1 region using an extracellular glass pipette filled with artificial cerebrospinal fluid. Morris water maze and Y-maze was performed to test cognitive function. RESULTS Our results demonstrated that FUS-mediated BBB opening has a significant impact on increasing LTP at Schaffer collateral - CA1 synapses and rescues cognitive dysfunction and working memory. These effects persisted for up to 7 weeks post-treatment. Also, FUS-mediated BBB opening in the hippocampus increased PKA phosphorylation. CONCLUSION Therefore, it could be a promising treatment for neurodegenerative diseases as it remarkably increases LTP, thereby improving working memory.
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Affiliation(s)
- Chanho Kong
- Department of Neurosurgery, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Ji Woong Ahn
- Department of Physiology, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Sohyun Kim
- Department of Physiology, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Ji Young Park
- Department of Neurosurgery, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Young Cheol Na
- Department of Neurosurgery, Catholic Kwandong University College of Medicine, International St Mary's Hospital, Incheon, Republic of Korea
| | - Jin Woo Chang
- Department of Neurosurgery, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Seungsoo Chung
- Department of Physiology, Yonsei University College of Medicine, Seoul, Republic of Korea.
| | - Won Seok Chang
- Department of Neurosurgery, Yonsei University College of Medicine, Seoul, Republic of Korea.
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6
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Blackmore DG, Razansky D, Götz J. Ultrasound as a versatile tool for short- and long-term improvement and monitoring of brain function. Neuron 2023; 111:1174-1190. [PMID: 36917978 DOI: 10.1016/j.neuron.2023.02.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 01/19/2023] [Accepted: 02/13/2023] [Indexed: 03/15/2023]
Abstract
Treating the brain with focused ultrasound (FUS) at low intensities elicits diverse responses in neurons, astroglia, and the extracellular matrix. In combination with intravenously injected microbubbles, FUS also opens the blood-brain barrier (BBB) and facilitates focal drug delivery. However, an incompletely understood cellular specificity and a wide parameter space currently limit the optimal application of FUS in preclinical and human studies. In this perspective, we discuss how different FUS modalities can be utilized to achieve short- and long-term improvements, thereby potentially treating brain disorders. We review the ongoing efforts to determine which parameters induce neuronal inhibition versus activation and how mechanoreceptors and signaling cascades are activated to induce long-term changes, including memory improvements. We suggest that optimal FUS treatments may require different FUS modalities and devices, depending on the targeted brain area or local pathology, and will be greatly enhanced by new techniques for monitoring FUS efficacy.
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Affiliation(s)
- Daniel G Blackmore
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Daniel Razansky
- Institute for Biomedical Engineering, Institute of Pharmacology and Toxicology, Faculty of Medicine, University of Zurich, 8057 Zurich, Switzerland; Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, ETH Zurich, 8093 Zurich, Switzerland
| | - Jürgen Götz
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia.
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7
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Preclinical Research on Focused Ultrasound-Mediated Blood-Brain Barrier Opening for Neurological Disorders: A Review. Neurol Int 2023; 15:285-300. [PMID: 36810473 PMCID: PMC9944161 DOI: 10.3390/neurolint15010018] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 02/02/2023] [Accepted: 02/10/2023] [Indexed: 02/17/2023] Open
Abstract
Several therapeutic agents for neurological disorders are usually not delivered to the brain owing to the presence of the blood-brain barrier (BBB), a special structure present in the central nervous system (CNS). Focused ultrasound (FUS) combined with microbubbles can reversibly and temporarily open the BBB, enabling the application of various therapeutic agents in patients with neurological disorders. In the past 20 years, many preclinical studies on drug delivery through FUS-mediated BBB opening have been conducted, and the use of this method in clinical applications has recently gained popularity. As the clinical application of FUS-mediated BBB opening expands, it is crucial to understand the molecular and cellular effects of FUS-induced microenvironmental changes in the brain so that the efficacy of treatment can be ensured, and new treatment strategies established. This review describes the latest research trends in FUS-mediated BBB opening, including the biological effects and applications in representative neurological disorders, and suggests future directions.
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8
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Abstract
This review deals with an unwelcome reality about several forms of dementia, including Alzheimer's disease- that these dementias are caused, in part or whole, by the aging of the vasculature. Since the vasculature ages in us all, dementia is our fate, sealed by the realit!ies of the circulation; it is not a disease with a cure pending. Empirically, cognitive impairment before our 7th decade is uncommon and considered early, while a diagnosis in our 11th decade is late but common in that cohort (>40%). Projections from earlier ages suggest that the prevalence of dementia in people surviving into their 12th decade exceeds 80%. We address the question why so few of many interventions known to delay dementia are recognized as therapy; and we try to resolve this few-and-many paradox, identifying opportunities for better treatment, especially pre-diagnosis. The idea of dementia as a fate is resisted, we argue, because it negates the hope of a cure. But the price of that hope is lost opportunity. An approach more in line with the evidence, and more likely to limit suffering, is to understand the damage that accumulates with age in the cerebral vasculature and therefore in the brain, and which eventually gives rise to cognitive symptoms in late life, too often leading to dementia. We argue that hope should be redirected to delaying that damage and with it the onset of cognitive loss; and, for each individual, it should be redirected to a life-long defense of their brain.
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Affiliation(s)
- Marcus J Andersson
- Faculty of Medicine and Health, University of Sydney, Camperdown, NSW, Australia
| | - Jonathan Stone
- School of Medical Sciences and Faculty of Medicine and Health, University of Sydney, Camperdown, NSW, Australia
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9
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Bok J, Ha J, Ahn BJ, Jang Y. Disease-Modifying Effects of Non-Invasive Electroceuticals on β-Amyloid Plaques and Tau Tangles for Alzheimer's Disease. Int J Mol Sci 2022; 24:ijms24010679. [PMID: 36614120 PMCID: PMC9821138 DOI: 10.3390/ijms24010679] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/22/2022] [Accepted: 12/27/2022] [Indexed: 01/04/2023] Open
Abstract
Electroceuticals refer to various forms of electronic neurostimulators used for therapy. Interdisciplinary advances in medical engineering and science have led to the development of the electroceutical approach, which involves therapeutic agents that specifically target neural circuits, to realize precision therapy for Alzheimer's disease (AD). To date, extensive studies have attempted to elucidate the disease-modifying effects of electroceuticals on areas in the brain of a patient with AD by the use of various physical stimuli, including electric, magnetic, and electromagnetic waves as well as ultrasound. Herein, we review non-invasive stimulatory systems and their effects on β-amyloid plaques and tau tangles, which are pathological molecular markers of AD. Therefore, this review will aid in better understanding the recent technological developments, applicable methods, and therapeutic effects of electronic stimulatory systems, including transcranial direct current stimulation, 40-Hz gamma oscillations, transcranial magnetic stimulation, electromagnetic field stimulation, infrared light stimulation and ionizing radiation therapy, and focused ultrasound for AD.
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Affiliation(s)
- Junsoo Bok
- Department of Medical and Digital Engineering, College of Engineering, Hanyang University, Seoul 04736, Republic of Korea
| | - Juchan Ha
- Department of Biomedical Engineering, College of Engineering, Hanyang University, Seoul 04736, Republic of Korea
| | - Bum Ju Ahn
- Department of Pharmacology, College of Medicine, Hanyang University, Seoul 04736, Republic of Korea
| | - Yongwoo Jang
- Department of Medical and Digital Engineering, College of Engineering, Hanyang University, Seoul 04736, Republic of Korea
- Department of Pharmacology, College of Medicine, Hanyang University, Seoul 04736, Republic of Korea
- Correspondence: ; Tel.: +82-2-2220-0655
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10
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Gorick CM, Breza VR, Nowak KM, Cheng VWT, Fisher DG, Debski AC, Hoch MR, Demir ZEF, Tran NM, Schwartz MR, Sheybani ND, Price RJ. Applications of focused ultrasound-mediated blood-brain barrier opening. Adv Drug Deliv Rev 2022; 191:114583. [PMID: 36272635 PMCID: PMC9712235 DOI: 10.1016/j.addr.2022.114583] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 09/01/2022] [Accepted: 10/14/2022] [Indexed: 01/25/2023]
Abstract
The blood brain barrier (BBB) plays a critically important role in the regulation of central nervous system (CNS) homeostasis, but also represents a major limitation to treatments of brain pathologies. In recent years, focused ultrasound (FUS) in conjunction with gas-filled microbubble contrast agents has emerged as a powerful tool for transiently and non-invasively disrupting the BBB in a targeted and image-guided manner, allowing for localized delivery of drugs, genes, or other therapeutic agents. Beyond the delivery of known therapeutics, FUS-mediated BBB opening also demonstrates the potential for use in neuromodulation and the stimulation of a range of cell- and tissue-level physiological responses that may prove beneficial in disease contexts. Clinical trials investigating the safety and efficacy of FUS-mediated BBB opening are well underway, and offer promising non-surgical approaches to treatment of devastating pathologies. This article reviews a range of pre-clinical and clinical studies demonstrating the tremendous potential of FUS to fundamentally change the paradigm of treatment for CNS diseases.
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Affiliation(s)
- Catherine M Gorick
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22908, USA
| | - Victoria R Breza
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22908, USA
| | - Katherine M Nowak
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA 22908, USA
| | - Vinton W T Cheng
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22908, USA; Leeds Institute of Medical Research, University of Leeds, Leeds, UK
| | - Delaney G Fisher
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22908, USA
| | - Anna C Debski
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22908, USA
| | - Matthew R Hoch
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22908, USA
| | - Zehra E F Demir
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22908, USA
| | - Nghi M Tran
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22908, USA
| | - Mark R Schwartz
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22908, USA
| | - Natasha D Sheybani
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22908, USA
| | - Richard J Price
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22908, USA.
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11
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Opportunities and challenges in delivering biologics for Alzheimer's disease by low-intensity ultrasound. Adv Drug Deliv Rev 2022; 189:114517. [PMID: 36030018 DOI: 10.1016/j.addr.2022.114517] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 08/15/2022] [Accepted: 08/19/2022] [Indexed: 01/24/2023]
Abstract
Low-intensity ultrasound combined with intravenously injected microbubbles (US+MB) is a novel treatment modality for brain disorders, including Alzheimer's disease (AD), safely and transiently allowing therapeutic agents to overcome the blood-brain barrier (BBB) that constitutes a major barrier for therapeutic agents. Here, we first provide an update on immunotherapies in AD and how US+MB has been applied to AD mouse models and in clinical trials, considering the ultrasound and microbubble parameter space. In the second half of the review, we compare different in vitro BBB models and discuss strategies for combining US+MB with BBB modulators (targeting molecules such as claudin-5), and highlight the insight provided by super-resolution microscopy. Finally, we conclude with a short discussion on how in vitro findings can inform the design of animal studies, and how the insight gained may aid treatment optimization in the clinical ultrasound space.
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12
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Ultrasound-Mediated Bioeffects in Senescent Mice and Alzheimer's Mouse Models. Brain Sci 2022; 12:brainsci12060775. [PMID: 35741660 PMCID: PMC9221310 DOI: 10.3390/brainsci12060775] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Revised: 06/09/2022] [Accepted: 06/10/2022] [Indexed: 02/01/2023] Open
Abstract
Ultrasound is routinely used for a wide range of diagnostic imaging applications. However, given that ultrasound can operate over a wide range of parameters that can all be modulated, its applicability extends far beyond the bioimaging field. In fact, the modality has emerged as a hybrid technology that effectively assists drug delivery by transiently opening the blood–brain barrier (BBB) when combined with intravenously injected microbubbles, and facilitates neuromodulation. Studies in aged mice contributed to an insight into how low-intensity ultrasound brings about its neuromodulatory effects, including increased synaptic plasticity and improved cognitive functions, with a potential role for neurogenesis and the modulation of NMDA receptor-mediated neuronal signalling. This work is complemented by studies in mouse models of Alzheimer’s disease (AD), a form of pathological ageing. Here, ultrasound was mainly employed as a BBB-opening tool that clears protein aggregates via microglial activation and neuronal autophagy, thereby restoring cognition. We discuss the currently available ultrasound approaches and how studies in senescent mice are relevant for AD and can accelerate the application of low-intensity ultrasound in the clinic.
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Blood-brain barrier leakage in Alzheimer's disease: From discovery to clinical relevance. Pharmacol Ther 2022; 234:108119. [PMID: 35108575 PMCID: PMC9107516 DOI: 10.1016/j.pharmthera.2022.108119] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/14/2022] [Accepted: 01/18/2022] [Indexed: 12/16/2022]
Abstract
Alzheimer's disease (AD) is the most common form of dementia. AD brain pathology starts decades before the onset of clinical symptoms. One early pathological hallmark is blood-brain barrier dysfunction characterized by barrier leakage and associated with cognitive decline. In this review, we summarize the existing literature on the extent and clinical relevance of barrier leakage in AD. First, we focus on AD animal models and their susceptibility to barrier leakage based on age and genetic background. Second, we re-examine barrier dysfunction in clinical and postmortem studies, summarize changes that lead to barrier leakage in patients and highlight the clinical relevance of barrier leakage in AD. Third, we summarize signaling mechanisms that link barrier leakage to neurodegeneration and cognitive decline in AD. Finally, we discuss clinical relevance and potential therapeutic strategies and provide future perspectives on investigating barrier leakage in AD. Identifying mechanistic steps underlying barrier leakage has the potential to unravel new targets that can be used to develop novel therapeutic strategies to repair barrier leakage and slow cognitive decline in AD and AD-related dementias.
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Leinenga G, Bodea L, Schröder J, Sun G, Zhou Y, Song J, Grubman A, Polo JM, Götz J. Transcriptional signature in microglia isolated from an Alzheimer's disease mouse model treated with scanning ultrasound. Bioeng Transl Med 2022; 8:e10329. [PMID: 36684089 PMCID: PMC9842024 DOI: 10.1002/btm2.10329] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 03/18/2022] [Accepted: 04/04/2022] [Indexed: 01/25/2023] Open
Abstract
Transcranial scanning ultrasound combined with intravenously injected microbubbles (SUS+MB) has been shown to transiently open the blood-brain barrier and reduce the amyloid-β (Aβ) pathology in the APP23 mouse model of Alzheimer's disease (AD). This has been accomplished through the activation of microglial cells; however, their response to the SUS treatment is incompletely understood. Here, wild-type (WT) and APP23 mice were subjected to SUS+MB, using nonsonicated mice as sham controls. After 48 h, the APP23 mice were injected with methoxy-XO4 to label Aβ aggregates, followed by microglial isolation into XO4+ and XO4- populations using flow cytometry. Both XO4+ and XO4- cells were subjected to RNA sequencing and transcriptome profiling. The analysis of the microglial cells revealed a clear segregation depending on genotype (AD model vs. WT mice) and Aβ internalization (XO4+ vs. XO4- microglia), but interestingly, no differences were found between SUS+MB and sham in WT mice. Differential gene expression analysis in APP23 mice detected 278 genes that were significantly changed by SUS+MB in the XO4+ cells (248 up/30 down) and 242 in XO- cells (225 up/17 down). Pathway analysis highlighted differential expression of genes related to the phagosome pathway and marked upregulation of cell cycle-related transcripts in XO4+ and XO4- microglia isolated from SUS+MB-treated APP23 mice. Together, this highlights the complexity of the microglial response to transcranial ultrasound, with potential applications for the treatment of AD.
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Affiliation(s)
- Gerhard Leinenga
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of QueenslandBrisbane (St Lucia Campus)QueenslandAustralia
| | - Liviu‐Gabriel Bodea
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of QueenslandBrisbane (St Lucia Campus)QueenslandAustralia
| | - Jan Schröder
- Department of Anatomy & Developmental Biology and the Australian Regenerative Medicine InstituteMonash UniversityMelbourneVictoriaAustralia
| | - Giuzhi Sun
- Department of Anatomy & Developmental Biology and the Australian Regenerative Medicine InstituteMonash UniversityMelbourneVictoriaAustralia
| | - Yichen Zhou
- Department of Anatomy & Developmental Biology and the Australian Regenerative Medicine InstituteMonash UniversityMelbourneVictoriaAustralia
| | - Jae Song
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of QueenslandBrisbane (St Lucia Campus)QueenslandAustralia
| | - Alexandra Grubman
- Department of Anatomy & Developmental Biology and the Australian Regenerative Medicine InstituteMonash UniversityMelbourneVictoriaAustralia
| | - Jose M. Polo
- Department of Anatomy & Developmental Biology and the Australian Regenerative Medicine InstituteMonash UniversityMelbourneVictoriaAustralia
| | - Jürgen Götz
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of QueenslandBrisbane (St Lucia Campus)QueenslandAustralia
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Liu X, Naomi SSM, Sharon WL, Russell EJ. The Applications of Focused Ultrasound (FUS) in Alzheimer's Disease Treatment: A Systematic Review on Both Animal and Human Studies. Aging Dis 2021; 12:1977-2002. [PMID: 34881081 PMCID: PMC8612615 DOI: 10.14336/ad.2021.0510] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 05/10/2021] [Indexed: 12/11/2022] Open
Abstract
Alzheimer's disease (AD) affects the basic ability to function and has imposed an immense burden on the community and health care system. Focused ultrasound (FUS) has recently been proposed as a novel noninvasive therapeutic approach for AD. However, systematic reviews on the FUS application in AD treatment have not been forthcoming. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria to summarize the techniques associated with safety and efficacy, as well as possible underlying mechanisms of FUS effects on AD in animal and human studies. Animal studies demonstrated FUS with microbubbles (FUS-MB) induced blood-brain-barrier (BBB) opening that could facilitate various therapeutic agents entering the brain. Repeated FUS-MB and FUS stimulation can relieve AD pathology and improve cognitive and memory function. Human studies showed repeated FUS-MB are well tolerated with few adverse events and FUS stimulation could enhance local perfusion and neural function, which correlated with cognitive improvement. We conclude that FUS is a feasible and safe therapeutic and drug delivery strategy for AD. However, FUS treatment on humans is still in the early stages and requires further optimization and standardization.
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Affiliation(s)
- Xiaodan Liu
- Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA, USA
| | - S. Sta Maria Naomi
- Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA, USA
| | - Wu Lin Sharon
- Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA, USA
| | - E. Jacobs Russell
- Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA, USA
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Pouliopoulos AN, Kwon N, Jensen G, Meaney A, Niimi Y, Burgess MT, Ji R, McLuckie AJ, Munoz FA, Kamimura HAS, Teich AF, Ferrera VP, Konofagou EE. Safety evaluation of a clinical focused ultrasound system for neuronavigation guided blood-brain barrier opening in non-human primates. Sci Rep 2021; 11:15043. [PMID: 34294761 PMCID: PMC8298475 DOI: 10.1038/s41598-021-94188-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 07/06/2021] [Indexed: 02/06/2023] Open
Abstract
An emerging approach with potential in improving the treatment of neurodegenerative diseases and brain tumors is the use of focused ultrasound (FUS) to bypass the blood-brain barrier (BBB) in a non-invasive and localized manner. A large body of pre-clinical work has paved the way for the gradual clinical implementation of FUS-induced BBB opening. Even though the safety profile of FUS treatments in rodents has been extensively studied, the histological and behavioral effects of clinically relevant BBB opening in large animals are relatively understudied. Here, we examine the histological and behavioral safety profile following localized BBB opening in non-human primates (NHPs), using a neuronavigation-guided clinical system prototype. We show that FUS treatment triggers a short-lived immune response within the targeted region without exacerbating the touch accuracy or reaction time in visual-motor cognitive tasks. Our experiments were designed using a multiple-case-study approach, in order to maximize the acquired data and support translation of the FUS system into human studies. Four NHPs underwent a single session of FUS-mediated BBB opening in the prefrontal cortex. Two NHPs were treated bilaterally at different pressures, sacrificed on day 2 and 18 post-FUS, respectively, and their brains were histologically processed. In separate experiments, two NHPs that were earlier trained in a behavioral task were exposed to FUS unilaterally, and their performance was tracked for at least 3 weeks after BBB opening. An increased microglia density around blood vessels was detected on day 2, but was resolved by day 18. We also detected signs of enhanced immature neuron presence within areas that underwent BBB opening, compared to regions with an intact BBB, confirming previous rodent studies. Logistic regression analysis showed that the NHP cognitive performance did not deteriorate following BBB opening. These preliminary results demonstrate that neuronavigation-guided FUS with a single-element transducer is a non-invasive method capable of reversibly opening the BBB, without substantial histological or behavioral impact in an animal model closely resembling humans. Future work should confirm the observations of this multiple-case-study work across animals, species and tasks.
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Affiliation(s)
- Antonios N. Pouliopoulos
- grid.21729.3f0000000419368729Department of Biomedical Engineering, Columbia University, New York City, NY 10032 USA
| | - Nancy Kwon
- grid.21729.3f0000000419368729Department of Biomedical Engineering, Columbia University, New York City, NY 10032 USA
| | - Greg Jensen
- grid.21729.3f0000000419368729Department of Neuroscience, Columbia University, New York City, NY 10032 USA
| | - Anna Meaney
- grid.21729.3f0000000419368729Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York City, NY 10027 USA
| | - Yusuke Niimi
- grid.21729.3f0000000419368729Department of Biomedical Engineering, Columbia University, New York City, NY 10032 USA
| | - Mark T. Burgess
- grid.21729.3f0000000419368729Department of Biomedical Engineering, Columbia University, New York City, NY 10032 USA
| | - Robin Ji
- grid.21729.3f0000000419368729Department of Biomedical Engineering, Columbia University, New York City, NY 10032 USA
| | - Alicia J. McLuckie
- grid.21729.3f0000000419368729Institute of Comparative Medicine, Columbia University, New York City, NY 10032 USA
| | - Fabian A. Munoz
- grid.21729.3f0000000419368729Department of Neuroscience, Columbia University, New York City, NY 10032 USA ,grid.21729.3f0000000419368729Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York City, NY 10027 USA
| | - Hermes A. S. Kamimura
- grid.21729.3f0000000419368729Department of Biomedical Engineering, Columbia University, New York City, NY 10032 USA
| | - Andrew F. Teich
- grid.21729.3f0000000419368729Department of Pathology and Cell Biology, Columbia University, New York City, NY 10032 USA
| | - Vincent P. Ferrera
- grid.21729.3f0000000419368729Department of Neuroscience, Columbia University, New York City, NY 10032 USA ,grid.21729.3f0000000419368729Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York City, NY 10027 USA ,grid.21729.3f0000000419368729Department of Psychiatry, Columbia University, New York City, NY
10032
USA
| | - Elisa E. Konofagou
- grid.21729.3f0000000419368729Department of Biomedical Engineering, Columbia University, New York City, NY 10032 USA ,grid.21729.3f0000000419368729Department of Radiology, Columbia University, New York City, NY 10032 USA
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Therapeutic Ultrasound as a Treatment Modality for Physiological and Pathological Ageing Including Alzheimer's Disease. Pharmaceutics 2021; 13:pharmaceutics13071002. [PMID: 34371696 PMCID: PMC8309087 DOI: 10.3390/pharmaceutics13071002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 06/29/2021] [Accepted: 06/29/2021] [Indexed: 01/09/2023] Open
Abstract
Physiological and pathological ageing (as exemplified by Alzheimer's disease, AD) are characterized by a progressive decline that also includes cognition. How this decline can be slowed or even reversed is a critical question. Here, we discuss therapeutic ultrasound as a novel modality to achieve this goal. In our studies, we explored three fundamental strategies, (i) scanning ultrasound on its own (SUSonly), (ii) therapeutic ultrasound in concert with intravenously injected microbubbles (which transiently opens the blood-brain barrier, SUS+MB), and (iii) SUS+MB in combination with therapeutic antibodies (SUS+MB+mAb). These studies show SUS+MB effectively clears amyloid and restores memory in amyloid-depositing mice and partially clears Tau and ameliorates memory impairments in Tau transgenic mice, with additional improvements found in combination trials (SUS+MB+mAb). Interestingly, both SUSonly and SUS+MB restored the induction of long-term potentiation (LTP, electrophysiological correlate of memory) in senescent wild-type mice. Both lead to increased neurogenesis, and SUSonly, in particular, resulted in improved spatial memory. We discuss these findings side-by-side with our findings obtained in AD mouse models. We conclude that therapeutic ultrasound is a non-invasive, pleiotropic modality that may present a treatment option not only for AD but also for enhancing cognition in physiological ageing.
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Leinenga G, Koh WK, Götz J. A comparative study of the effects of Aducanumab and scanning ultrasound on amyloid plaques and behavior in the APP23 mouse model of Alzheimer disease. ALZHEIMERS RESEARCH & THERAPY 2021; 13:76. [PMID: 33836798 PMCID: PMC8035770 DOI: 10.1186/s13195-021-00809-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 03/15/2021] [Indexed: 12/12/2022]
Abstract
BACKGROUND Aducanumab is an anti-amyloid-β (Aβ) antibody that achieved reduced amyloid pathology in Alzheimer's disease (AD) trials; however, it is controversial whether it also improved cognition, which has been suggested would require a sufficiently high cumulative dose of the antibody in the brain. Therapeutic ultrasound, in contrast, has only begun to be investigated in human AD clinical trials. We have previously shown that scanning ultrasound in combination with intravenously injected microbubbles (SUS), which temporarily and safely opens the blood-brain barrier (BBB), removes amyloid and restores cognition in APP23 mice. However, there has been no direct testing of how the effects of SUS compare to immunotherapy or whether a combination therapy is more effective. METHODS In a study comprising four treatment arms, we tested the efficacy of an Aducanumab analog, Adu, both in comparison to SUS, and as a combination therapy, in APP23 mice (aged 13-22 months), using sham as a control. The active place avoidance (APA) test was used to test spatial memory, and histology and ELISA were used to measure amyloid. Brain antibody levels were also determined. RESULTS We found that both Adu and SUS reduced the total plaque area in the hippocampus with no additive effect observed with the combination treatment (SUS + Adu). Whereas in the cortex where there was a trend towards reducing the total plaque area from either Adu or SUS, only the combination treatment yielded a statistically significant decrease in total plaque area compared to sham. Only the SUS and SUS + Adu groups included animals that had their plaque load reduced to below 1% from above 10%. There was a robust improvement in spatial memory for the SUS + Adu group only, and in this group the level of Adu, when measured 3 days post-treatment, was 5-fold higher compared to those mice that received Adu on its own. Together, these findings suggest that SUS should be considered as a treatment option for AD. Alternatively, a combination trial using Aducanumab together with ultrasound to increase brain levels of the antibody may be warranted.
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Affiliation(s)
- Gerhard Leinenga
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Wee Kiat Koh
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Jürgen Götz
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia.
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19
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Clinically approved IVIg delivered to the hippocampus with focused ultrasound promotes neurogenesis in a model of Alzheimer's disease. Proc Natl Acad Sci U S A 2020; 117:32691-32700. [PMID: 33288687 DOI: 10.1073/pnas.1908658117] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Preclinical and clinical data support the use of focused ultrasound (FUS), in the presence of intravenously injected microbubbles, to safely and transiently increase the permeability of the blood-brain barrier (BBB). FUS-induced BBB permeability has been shown to enhance the bioavailability of administered intravenous therapeutics to the brain. Ideal therapeutics candidates for this mode of delivery are those capable of inducing benefits peripherally following intravenous injection and in the brain at FUS-targeted areas. In Alzheimer's disease, intravenous immunoglobulin (IVIg), a fractionated human blood product containing polyclonal antibodies, act as immunomodulator peripherally and centrally, and it can reduce amyloid pathology in the brain. Using the TgCRND8 mouse model of amyloidosis, we tested whether FUS can improve the delivery of IVIg, administered intravenously (0.4 g/kg), to the hippocampus and reach an effective dose to reduce amyloid plaque pathology and promote neurogenesis. Our results show that FUS-induced BBB permeability is required to deliver a significant amount of IVIg (489 ng/mg) to the targeted hippocampus of TgCRN8 mice. Two IVIg-FUS treatments, administered at days 1 and 8, significantly increased hippocampal neurogenesis by 4-, 3-, and 1.5-fold in comparison to saline, IVIg alone, and FUS alone, respectively. Amyloid plaque pathology was significantly reduced in all treatment groups: IVIg alone, FUS alone, and IVIg-FUS. Putative factors promoting neurogenesis in response to IVIg-FUS include the down-regulation of the proinflammatory cytokine TNF-α in the hippocampus. In summary, FUS was required to deliver an effective dose of IVIg to promote hippocampal neurogenesis and modulate the inflammatory milieu.
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Bobola MS, Chen L, Ezeokeke CK, Olmstead TA, Nguyen C, Sahota A, Williams RG, Mourad PD. Transcranial focused ultrasound, pulsed at 40 Hz, activates microglia acutely and reduces Aβ load chronically, as demonstrated in vivo. Brain Stimul 2020; 13:1014-1023. [PMID: 32388044 DOI: 10.1016/j.brs.2020.03.016] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 02/18/2020] [Accepted: 03/26/2020] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVE Iaccarino et al. (2016) [1] exposed 1 h of light flickering at 40 Hz to awake 5XFAD Alzheimer's Disease (AD) mouse models, generating action potentials at 40 Hz, activating ∼54% of microglia to colocalize with Aβ plaque, acutely, and clearing ∼ 50% of Aβ plaque after seven days, but only in the visual cortex. HYPOTHESIS Transcranially delivered, focused ultrasound (tFUS) can replicate the results of Iaccarino et al. (2016) [1] but throughout its area of application. METHODS We exposed sedated 5XFAD mice to tFUS (2.0 MHz carrier frequency, 40 Hz pulse repetition frequency, 400 μs-long pulses, spatial peak pulse average value of 190 W/cm2). Acute studies targeted tFUS into one hemisphere of brain centered on its hippocampus for 1 h. Chronic studies targeted comparable brain in each hemisphere for 1 h/day for five days. RESULTS Acute application of tFUS activated more microglia that colocalized with Aβ plaque relative to sham ultrasound (36.0 ± 4.6% versus 14.2 ± 2.6% [mean ± standard error], z = 2.45, p < 0.014) and relative to the contralateral hemisphere of treated brain (36.0 ± 4.6% versus 14.3 ± 4.0%, z = 2.61, p < 0.009). Chronic application over five days reduced their Aβ plaque burden by nearly half relative to paired sham animals (47.4 ± 5.8%, z = - 2.79, p < 0.005). CONCLUSION Our results compare to those of Iaccarino et al. (2016) [1] but throughout the area of ultrasound-exposed brain. Our results also compare to those achieved by medications that target Aβ, but over a substantially shorter period of time. The proximity of our ultrasound protocol to those shown safe for non-human primates and humans may motivate its rapid translation to human studies.
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Affiliation(s)
- M S Bobola
- Department of Neurological Surgery, University of Washington, Seattle, WA, USA
| | - L Chen
- Department of Neurological Surgery, University of Washington, Seattle, WA, USA
| | - C K Ezeokeke
- Department of Neurological Surgery, University of Washington, Seattle, WA, USA
| | - T A Olmstead
- Department of Neurological Surgery, University of Washington, Seattle, WA, USA
| | - C Nguyen
- Department of Neurological Surgery, University of Washington, Seattle, WA, USA
| | - A Sahota
- Department of Neurological Surgery, University of Washington, Seattle, WA, USA
| | - R G Williams
- Department of Neurological Surgery, University of Washington, Seattle, WA, USA
| | - P D Mourad
- Department of Neurological Surgery, University of Washington, Seattle, WA, USA; Division of Engineering and Mathematics, University of Washington, Bothell, WA, USA.
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Pandit R, Chen L, Götz J. The blood-brain barrier: Physiology and strategies for drug delivery. Adv Drug Deliv Rev 2019; 165-166:1-14. [PMID: 31790711 DOI: 10.1016/j.addr.2019.11.009] [Citation(s) in RCA: 252] [Impact Index Per Article: 50.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 11/19/2019] [Accepted: 11/24/2019] [Indexed: 12/14/2022]
Abstract
The blood-brain barrier (BBB) is a dynamic structure that functions as a gatekeeper, reflecting the unique requirements of the brain. In this review, following a brief historical overview of how the concepts of the BBB and the neurovascular unit (NVU) developed, we describe its physiology and architecture, which pose a particular challenge to therapeutic intervention. We then discuss how the restrictive nature of this barrier can be overcome for the delivery of therapeutic agents. Alterations to drug formulation offer one option, in part by utilizing distinct transport modes; another is invasive or non-invasive strategies to bypass the BBB. An emerging non-invasive technology for targeted drug delivery is focused ultrasound that allows for the safe and reversible disruption of the BBB. We discuss the underlying mechanisms and provide an outlook, emphasizing the need for more research into the NVU and investment in innovative technologies to overcome the BBB for drug delivery.
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Affiliation(s)
- Rucha Pandit
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Liyu Chen
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Jürgen Götz
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia.
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