1
|
Doran PR, Fomin-Thunemann N, Tang RP, Balog D, Zimmerman B, Kilic K, Martin EA, Kura S, Fisher HP, Chabbott G, Herbert J, Rauscher BC, Jiang JX, Sakadzic S, Boas DA, Devor A, Chen IA, Thunemann M. Widefield in vivo imaging system with two fluorescence and two reflectance channels, a single sCMOS detector, and shielded illumination. bioRxiv 2024:2023.11.07.566086. [PMID: 37986755 PMCID: PMC10659277 DOI: 10.1101/2023.11.07.566086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
SIGNIFICANCE Widefield microscopy of the entire dorsal part of mouse cerebral cortex enables large-scale (mesoscopic) imaging of neuronal activity with fluorescent indicators as well as hemodynamics via oxy- and deoxyhemoglobin absorption. Versatile and cost-effective imaging systems are needed for large-scale, color-multiplexed imaging of multiple fluorescent and intrinsic contrasts. AIM Develop a system for mesoscopic imaging of two fluorescent and two reflectance channels. APPROACH Excitation of red and green fluorescence is achieved through epi-illumination. Hemoglobin absorption imaging is achieved using 525- and 625nm LEDs positioned around the objective lens. An aluminum hemisphere placed between objective and cranial window provides diffuse illumination of the brain. Signals are recorded sequentially by a single sCMOS detector. RESULTS We demonstrate performance of our imaging system by recording large-scale spontaneous and stimulus-evoked neuronal, cholinergic, and hemodynamic activity in awake head-fixed mice with a curved crystal skull window expressing the red calcium indicator jRGECO1a and the green acetylcholine sensor GRABACh3.0 . Shielding of illumination light through the aluminum hemisphere enables concurrent recording of pupil diameter changes. CONCLUSIONS Our widefield microscope design with single camera can be used to acquire multiple aspects of brain physiology and is compatible with behavioral readouts of pupil diameter.
Collapse
|
2
|
Giblin J, Kura S, Nunuez JLU, Zhang J, Kureli G, Jiang J, Boas DA, Chen IA. High throughput detection of capillary stalling events with Bessel beam two-photon microscopy. Neurophotonics 2023; 10:035009. [PMID: 37705938 PMCID: PMC10495839 DOI: 10.1117/1.nph.10.3.035009] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 08/09/2023] [Accepted: 08/17/2023] [Indexed: 09/15/2023]
Abstract
Significance Brief disruptions in capillary flow, commonly referred to as capillary "stalling," have gained interest recently for their potential role in disrupting cerebral blood flow and oxygen delivery. Approaches to studying this phenomenon have been hindered by limited volumetric imaging rates and cumbersome manual analysis. The ability to precisely and efficiently quantify the dynamics of these events will be key in understanding their potential role in stroke and neurodegenerative diseases, such as Alzheimer's disease. Aim Our study aimed to demonstrate that the fast volumetric imaging rates offered by Bessel beam two-photon microscopy combined with improved data analysis throughput allows for faster and more precise measurement of capillary stall dynamics. Results We found that while our analysis approach was unable to achieve full automation, we were able to cut analysis time in half while also finding stalling events that were missed in traditional blind manual analysis. The resulting data showed that our Bessel beam system was captured more stalling events compared to optical coherence tomography, particularly shorter stalling events. We then compare differences in stall dynamics between a young and old group of mice as well as a demonstrate changes in stalling before and after photothrombotic model of stroke. Finally, we also demonstrate the ability to monitor arteriole dynamics alongside stall dynamics. Conclusions Bessel beam two-photon microscopy combined with high throughput analysis is a powerful tool for studying capillary stalling due to its ability to monitor hundreds of capillaries simultaneously at high frame rates.
Collapse
Affiliation(s)
- John Giblin
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
- Boston University, Neurophotonics Center, Boston, Massachusetts, United States
| | - Sreekanth Kura
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
- Boston University, Neurophotonics Center, Boston, Massachusetts, United States
| | - Juan Luis Ugarte Nunuez
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
- Boston University, Neurophotonics Center, Boston, Massachusetts, United States
| | - Juncheng Zhang
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
- Boston University, Neurophotonics Center, Boston, Massachusetts, United States
| | - Gulce Kureli
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
- Boston University, Neurophotonics Center, Boston, Massachusetts, United States
| | - John Jiang
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
- Boston University, Neurophotonics Center, Boston, Massachusetts, United States
| | - David A. Boas
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
- Boston University, Neurophotonics Center, Boston, Massachusetts, United States
| | - Ichun A. Chen
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
- Boston University, Neurophotonics Center, Boston, Massachusetts, United States
| |
Collapse
|
3
|
Giblin JT, Park SW, Jiang J, Kılıç K, Kura S, Tang J, Boas DA, Chen IA. Measuring capillary flow dynamics using interlaced two-photon volumetric scanning. J Cereb Blood Flow Metab 2023; 43:595-609. [PMID: 36495178 PMCID: PMC10063827 DOI: 10.1177/0271678x221145091] [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] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Two photon microscopy and optical coherence tomography (OCT) are two standard methods for measuring flow speeds of red blood cells in microvessels, particularly in animal models. However, traditional two photon microscopy lacks the depth of field to adequately capture the full volumetric complexity of the cerebral microvasculature and OCT lacks the specificity offered by fluorescent labeling. In addition, the traditional raster scanning technique utilized in both modalities requires a balance of image frame rate and field of view, which severely limits the study of RBC velocities in the microvascular network. Here, we overcome this by using a custom two photon system with an axicon based Bessel beam to obtain volumetric images of the microvascular network with fluorescent specificity. We combine this with a novel scan pattern that generates pairs of frames with short time delay sufficient for tracking red blood cell flow in capillaries. We track RBC flow speeds in 10 or more capillaries simultaneously at 1 Hz in a 237 µm × 237 µm × 120 µm volume and quantified both their spatial and temporal variability in speed. We also demonstrate the ability to track flow speed changes around stalls in capillary flow and measure to 300 µm in depth.
Collapse
Affiliation(s)
- John T Giblin
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Seong-Wook Park
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - John Jiang
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Kıvılcım Kılıç
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Sreekanth Kura
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Jianbo Tang
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, China
| | - David A Boas
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Ichun A Chen
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| |
Collapse
|
4
|
Sunil S, Jiang J, Shah S, Kura S, Kilic K, Erdener SE, Ayata C, Devor A, Boas DA. Neurovascular coupling is preserved in chronic stroke recovery after targeted photothrombosis. Neuroimage Clin 2023; 38:103377. [PMID: 36948140 PMCID: PMC10034641 DOI: 10.1016/j.nicl.2023.103377] [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] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 03/07/2023] [Accepted: 03/09/2023] [Indexed: 03/17/2023]
Abstract
Functional neuroimaging, which measures hemodynamic responses to brain activity, has great potential for monitoring recovery in stroke patients and guiding rehabilitation during recovery. However, hemodynamic responses after stroke are almost always altered relative to responses in healthy subjects and it is still unclear if these alterations reflect the underlying brain physiology or if the alterations are purely due to vascular injury. In other words, we do not know the effect of stroke on neurovascular coupling and are therefore limited in our ability to use functional neuroimaging to accurately interpret stroke pathophysiology. To address this challenge, we simultaneously captured neural activity, through fluorescence calcium imaging, and hemodynamics, through intrinsic optical signal imaging, during longitudinal stroke recovery. Our data suggest that neurovascular coupling was preserved in the chronic phase of recovery (2 weeks and 4 weeks post-stoke) and resembled pre-stroke neurovascular coupling. This indicates that functional neuroimaging faithfully represents the underlying neural activity in chronic stroke. Further, neurovascular coupling in the sub-acute phase of stroke recovery was predictive of long-term behavioral outcomes. Stroke also resulted in increases in global brain oscillations, which showed distinct patterns between neural activity and hemodynamics. Increased neural excitability in the contralesional hemisphere was associated with increased contralesional intrahemispheric connectivity. Additionally, sub-acute increases in hemodynamic oscillations were associated with improved sensorimotor outcomes. Collectively, these results support the use of hemodynamic measures of brain activity post-stroke for predicting functional and behavioral outcomes.
Collapse
Affiliation(s)
- Smrithi Sunil
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA.
| | - John Jiang
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Shashwat Shah
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Sreekanth Kura
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Kivilcim Kilic
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Sefik Evren Erdener
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Cenk Ayata
- Departments of Neurology and Radiology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Anna Devor
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA; Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA 02114, USA
| | - David A Boas
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA.
| |
Collapse
|
5
|
Tucker S, Dubb J, Kura S, von Lühmann A, Franke R, Horschig JM, Powell S, Oostenveld R, Lührs M, Delaire É, Aghajan ZM, Yun H, Yücel MA, Fang Q, Huppert TJ, Frederick BB, Pollonini L, Boas D, Luke R. Introduction to the shared near infrared spectroscopy format. Neurophotonics 2023; 10:013507. [PMID: 36507152 PMCID: PMC9732807 DOI: 10.1117/1.nph.10.1.013507] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 11/23/2022] [Indexed: 05/12/2023]
Abstract
Significance Functional near-infrared spectroscopy (fNIRS) is a popular neuroimaging technique with proliferating hardware platforms, analysis approaches, and software tools. There has not been a standardized file format for storing fNIRS data, which has hindered the sharing of data as well as the adoption and development of software tools. Aim We endeavored to design a file format to facilitate the analysis and sharing of fNIRS data that is flexible enough to meet the community's needs and sufficiently defined to be implemented consistently across various hardware and software platforms. Approach The shared NIRS format (SNIRF) specification was developed in consultation with the academic and commercial fNIRS community and the Society for functional Near Infrared Spectroscopy. Results The SNIRF specification defines a format for fNIRS data acquired using continuous wave, frequency domain, time domain, and diffuse correlation spectroscopy devices. Conclusions We present the SNIRF along with validation software and example datasets. Support for reading and writing SNIRF data has been implemented by major hardware and software platforms, and the format has found widespread use in the fNIRS community.
Collapse
Affiliation(s)
- Stephen Tucker
- Boston University, Neurophotonics Center, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Jay Dubb
- Boston University, Neurophotonics Center, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Sreekanth Kura
- Boston University, Neurophotonics Center, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Alexander von Lühmann
- Boston University, Neurophotonics Center, Department of Biomedical Engineering, Boston, Massachusetts, United States
- NIRx Medical Technologies, Berlin, Germany
| | | | | | - Samuel Powell
- Gowerlabs, London, United Kingdom
- University of Nottingham, Nottingham, United Kingdom
- University College London, London, United Kingdom
| | - Robert Oostenveld
- Radboud University, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
- Karolinska Institutet, NatMEG, Stockholm, Sweden
| | - Michael Lührs
- Maastricht University, Maastricht, The Netherlands
- Brain Innovation B.V., Maastricht, The Netherlands
| | | | | | | | - Meryem A. Yücel
- Boston University, Neurophotonics Center, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Qianqian Fang
- Northeastern University, Department of Bioengineering, Boston, Massachusetts, United States
| | | | - Blaise B. Frederick
- Mclean Hospital, Brain Imaging Center, Belmont, Massachusetts, United States
- Harvard Medical School, Department of Psychiatry, Boston, Massachusetts, United States
| | | | - David Boas
- Boston University, Neurophotonics Center, Department of Biomedical Engineering, Boston, Massachusetts, United States
- Address all correspondence to David Boas,
| | | |
Collapse
|
6
|
Yang J, Chang S, Chen IA, Kura S, Rosen GA, Saltiel NA, Huber BR, Varadarajan D, Balbastre Y, Magnain C, Chen SC, Fischl B, McKee AC, Boas DA, Wang H. Volumetric Characterization of Microvasculature in Ex Vivo Human Brain Samples By Serial Sectioning Optical Coherence Tomography. IEEE Trans Biomed Eng 2022; 69:3645-3656. [PMID: 35560084 PMCID: PMC9888394 DOI: 10.1109/tbme.2022.3175072] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Serial sectioning optical coherence tomography (OCT) enables accurate volumetric reconstruction of several cubic centimeters of human brain samples. We aimed to identify anatomical features of the ex vivo human brain, such as intraparenchymal blood vessels and axonal fiber bundles, from the OCT data in 3D, using intrinsic optical contrast. METHODS We developed an automatic processing pipeline to enable characterization of the intraparenchymal microvascular network in human brain samples. RESULTS We demonstrated the automatic extraction of the vessels down to a 20 μm in diameter using a filtering strategy followed by a graphing representation and characterization of the geometrical properties of microvascular network in 3D. We also showed the ability to extend this processing strategy to extract axonal fiber bundles from the volumetric OCT image. CONCLUSION This method provides a viable tool for quantitative characterization of volumetric microvascular network as well as the axonal bundle properties in normal and pathological tissues of the ex vivo human brain.
Collapse
|
7
|
Aykan SA, Xie H, Zheng Y, Chung DY, Kura S, Han Lai J, Erdogan TD, Morais A, Tamim I, Yagmur D, Ishikawa H, Arai K, Abbas Yaseen M, Boas DA, Sakadzic S, Ayata C. Rho-Kinase Inhibition Improves the Outcome of Focal Subcortical White Matter Lesions. Stroke 2022; 53:2369-2376. [PMID: 35656825 DOI: 10.1161/strokeaha.121.037358] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Subcortical white matter lesions are exceedingly common in cerebral small vessel disease and lead to significant cumulative disability without an available treatment. Here, we tested a rho-kinase inhibitor on functional recovery after focal white matter injury. METHODS A focal corpus callosum lesion was induced by stereotactic injection of N5-(1-iminoethyl)-L-ornithine in mice. Fasudil (10 mg/kg) or vehicle was administered daily for 2 weeks, starting one day after lesion induction. Resting-state functional connectivity and grid walk performance were studied longitudinally, and lesion volumes were determined at one month. RESULTS Resting-state interhemispheric functional connectivity significantly recovered between days 1 and 14 in the fasudil group (P<0.001), despite worse initial connectivity loss than vehicle before treatment onset. Grid walk test revealed an increased number of foot faults in the vehicle group compared with baseline, which persisted for at least 4 weeks. In contrast, the fasudil arm did not show an increase in foot faults and had smaller lesions at 4 weeks. Immunohistochemical examination of reactive astrocytosis, synaptic density, and mature oligodendrocytes did not reveal a significant difference between treatment arms. CONCLUSIONS These data show that delayed fasudil posttreatment improves functional outcomes after a focal subcortical white matter lesion in mice. Future work will aim to elucidate the mechanisms.
Collapse
Affiliation(s)
- Sanem A Aykan
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Charlestown (S.A.A., H.X., Y.Z., D.Y.C., J.H.L., T.D.E., A.M., I.T., D.Y., C.A.)
| | - Hongyu Xie
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Charlestown (S.A.A., H.X., Y.Z., D.Y.C., J.H.L., T.D.E., A.M., I.T., D.Y., C.A.).,Department of Rehabilitation, Huashan Hospital, Fudan University, Shanghai, China (H.X.)
| | - Yi Zheng
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Charlestown (S.A.A., H.X., Y.Z., D.Y.C., J.H.L., T.D.E., A.M., I.T., D.Y., C.A.)
| | - David Y Chung
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Charlestown (S.A.A., H.X., Y.Z., D.Y.C., J.H.L., T.D.E., A.M., I.T., D.Y., C.A.).,Stroke Service, Department of Neurology, Massachusetts General Hospital, Charlestown, MA. (C.A., D.Y.C.)
| | - Sreekanth Kura
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, MA (S.K., D.A.B.)
| | - James Han Lai
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Charlestown (S.A.A., H.X., Y.Z., D.Y.C., J.H.L., T.D.E., A.M., I.T., D.Y., C.A.)
| | - Taylan D Erdogan
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Charlestown (S.A.A., H.X., Y.Z., D.Y.C., J.H.L., T.D.E., A.M., I.T., D.Y., C.A.)
| | - Andreia Morais
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Charlestown (S.A.A., H.X., Y.Z., D.Y.C., J.H.L., T.D.E., A.M., I.T., D.Y., C.A.)
| | - Isra Tamim
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Charlestown (S.A.A., H.X., Y.Z., D.Y.C., J.H.L., T.D.E., A.M., I.T., D.Y., C.A.)
| | - Damla Yagmur
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Charlestown (S.A.A., H.X., Y.Z., D.Y.C., J.H.L., T.D.E., A.M., I.T., D.Y., C.A.)
| | - Hidehiro Ishikawa
- Neuroprotection Research Laboratory, Department of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown. (H.I., K.A.)
| | - Ken Arai
- Neuroprotection Research Laboratory, Department of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown. (H.I., K.A.)
| | - M Abbas Yaseen
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA. (D.A.B., M.A.Y., S.S.)
| | - David A Boas
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, MA (S.K., D.A.B.).,Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA. (D.A.B., M.A.Y., S.S.)
| | - Sava Sakadzic
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA. (D.A.B., M.A.Y., S.S.)
| | - Cenk Ayata
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Charlestown (S.A.A., H.X., Y.Z., D.Y.C., J.H.L., T.D.E., A.M., I.T., D.Y., C.A.).,Stroke Service, Department of Neurology, Massachusetts General Hospital, Charlestown, MA. (C.A., D.Y.C.)
| |
Collapse
|
8
|
Şencan İ, Esipova T, Kılıç K, Li B, Desjardins M, Yaseen MA, Wang H, Porter JE, Kura S, Fu B, Secomb TW, Boas DA, Vinogradov SA, Devor A, Sakadžić S. Optical measurement of microvascular oxygenation and blood flow responses in awake mouse cortex during functional activation. J Cereb Blood Flow Metab 2022; 42:510-525. [PMID: 32515672 PMCID: PMC8985437 DOI: 10.1177/0271678x20928011] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The cerebral cortex has a number of conserved morphological and functional characteristics across brain regions and species. Among them, the laminar differences in microvascular density and mitochondrial cytochrome c oxidase staining suggest potential laminar variability in the baseline O2 metabolism and/or laminar variability in both O2 demand and hemodynamic response. Here, we investigate the laminar profile of stimulus-induced intravascular partial pressure of O2 (pO2) transients to stimulus-induced neuronal activation in fully awake mice using two-photon phosphorescence lifetime microscopy. Our results demonstrate that stimulus-induced changes in intravascular pO2 are conserved across cortical layers I-IV, suggesting a tightly controlled neurovascular response to provide adequate O2 supply across cortical depth. In addition, we observed a larger change in venular O2 saturation (ΔsO2) compared to arterioles, a gradual increase in venular ΔsO2 response towards the cortical surface, and absence of the intravascular "initial dip" previously reported under anesthesia. This study paves the way for quantification of layer-specific cerebral O2 metabolic responses, facilitating investigation of brain energetics in health and disease and informed interpretation of laminar blood oxygen level dependent functional magnetic resonance imaging signals.
Collapse
Affiliation(s)
- İkbal Şencan
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Tatiana Esipova
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA, USA
| | - Kıvılcım Kılıç
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Baoqiang Li
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Michèle Desjardins
- Department of Physics, Engineering Physics and Optics, Université Laval, QC, Canada
| | - Mohammad A Yaseen
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Hui Wang
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Jason E Porter
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Sreekanth Kura
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Buyin Fu
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Timothy W Secomb
- Department of Physiology, University of Arizona, Tucson, AZ, USA
| | - David A Boas
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Sergei A Vinogradov
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA, USA
| | - Anna Devor
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA.,Department of Biomedical Engineering, Boston University, Boston, MA, USA.,Department of Neurosciences, University of California San Diego, La Jolla, CA, USA.,Department of Radiology, University of California San Diego, La Jolla, CA, USA
| | - Sava Sakadžić
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| |
Collapse
|
9
|
Chang S, Varadarajan D, Yang J, Chen IA, Kura S, Magnain C, Augustinack JC, Fischl B, Greve DN, Boas DA, Wang H. Scalable mapping of myelin and neuron density in the human brain with micrometer resolution. Sci Rep 2022; 12:363. [PMID: 35013441 PMCID: PMC8748995 DOI: 10.1038/s41598-021-04093-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 12/03/2021] [Indexed: 12/23/2022] Open
Abstract
Optical coherence tomography (OCT) is an emerging 3D imaging technique that allows quantification of intrinsic optical properties such as scattering coefficient and back-scattering coefficient, and has proved useful in distinguishing delicate microstructures in the human brain. The origins of scattering in brain tissues are contributed by the myelin content, neuron size and density primarily; however, no quantitative relationships between them have been reported, which hampers the use of OCT in fundamental studies of architectonic areas in the human brain and the pathological evaluations of diseases. Here, we built a generalized linear model based on Mie scattering theory that quantitatively links tissue scattering to myelin content and neuron density in the human brain. We report a strong linear relationship between scattering coefficient and the myelin content that is retained across different regions of the brain. Neuronal cell body turns out to be a secondary contribution to the overall scattering. The optical property of OCT provides a label-free solution for quantifying volumetric myelin content and neuron cells in the human brain.
Collapse
Affiliation(s)
- Shuaibin Chang
- Department of Electrical and Computer Engineering, Boston University, 8 St Mary's St, Boston, 02215, USA
| | - Divya Varadarajan
- Department of Radiology, Massachusetts General Hospital, A.A. Martinos Center for Biomedical Imaging, 13th Street, Boston, 02129, USA
| | - Jiarui Yang
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, 02215, USA
| | - Ichun Anderson Chen
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, 02215, USA
| | - Sreekanth Kura
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, 02215, USA
| | - Caroline Magnain
- Department of Radiology, Massachusetts General Hospital, A.A. Martinos Center for Biomedical Imaging, 13th Street, Boston, 02129, USA
| | - Jean C Augustinack
- Department of Radiology, Massachusetts General Hospital, A.A. Martinos Center for Biomedical Imaging, 13th Street, Boston, 02129, USA
| | - Bruce Fischl
- Department of Radiology, Massachusetts General Hospital, A.A. Martinos Center for Biomedical Imaging, 13th Street, Boston, 02129, USA
| | - Douglas N Greve
- Department of Radiology, Massachusetts General Hospital, A.A. Martinos Center for Biomedical Imaging, 13th Street, Boston, 02129, USA
| | - David A Boas
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, 02215, USA
- Department of Electrical and Computer Engineering, Boston University, 8 St Mary's St, Boston, 02215, USA
| | - Hui Wang
- Department of Radiology, Massachusetts General Hospital, A.A. Martinos Center for Biomedical Imaging, 13th Street, Boston, 02129, USA.
| |
Collapse
|
10
|
Anzabi M, Li B, Wang H, Kura S, Sakadžić S, Boas D, Østergaard L, Ayata C. Optical coherence tomography of arteriolar diameter and capillary perfusion during spreading depolarizations. J Cereb Blood Flow Metab 2021; 41:2256-2263. [PMID: 33593116 PMCID: PMC8393288 DOI: 10.1177/0271678x21994013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 09/13/2020] [Revised: 12/21/2020] [Accepted: 01/08/2021] [Indexed: 11/17/2022]
Abstract
Spreading depolarization (SD) is associated with profound oligemia and reduced oxygen availability in the mouse cortex during the depolarization phase. Coincident pial arteriolar constriction has been implicated as the primary mechanism for the oligemia. However, where in the vascular bed the hemodynamic response starts has been unclear. To resolve the origin of the hemodynamic response, we used optical coherence tomography (OCT) to simultaneously monitor changes in the vascular tree from capillary bed to pial arteries in mice during two consecutive SDs 15 minutes apart. We found that capillary flow dropped several seconds before pial arteriolar constriction. Moreover, penetrating arterioles constricted before pial arteries suggesting upstream propagation of constriction. Smaller caliber distal pial arteries constricted stronger than larger caliber proximal arterioles, suggesting that the farther the constriction propagates, the weaker it gets. Altogether, our data indicate that the hemodynamic response to cortical SD originates in the capillary bed.
Collapse
Affiliation(s)
- Maryam Anzabi
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, USA
- Center of Functionally Integrative Neuroscience (CFIN) and MINDLab, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Baoqiang Li
- Brain Cognition and Brain Disease Institute, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences
| | - Hui Wang
- Shenzhen-Hong Kong Institute of Brain Science, Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - Sreekanth Kura
- Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, USA
| | - Sava Sakadžić
- Shenzhen-Hong Kong Institute of Brain Science, Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - David Boas
- Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, USA
| | - Leif Østergaard
- Center of Functionally Integrative Neuroscience (CFIN) and MINDLab, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Cenk Ayata
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, USA
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, USA
| |
Collapse
|
11
|
Oka F, Sadeghian H, Yaseen MA, Fu B, Kura S, Qin T, Sakadžić S, Sugimoto K, Inoue T, Ishihara H, Nomura S, Suzuki M, Ayata C. Intracranial pressure spikes trigger spreading depolarizations. Brain 2021; 145:194-207. [PMID: 34245240 PMCID: PMC9126007 DOI: 10.1093/brain/awab256] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [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: 12/07/2020] [Revised: 05/29/2021] [Accepted: 06/17/2021] [Indexed: 01/09/2023] Open
Abstract
Spreading depolarizations are highly prevalent and spatiotemporally punctuated events worsening the outcome of brain injury. Trigger factors are poorly understood but may be linked to sudden worsening in supply-demand mismatch in compromised tissue. Sustained or transient elevations in intracranial pressure are also prevalent in the injured brain. Here, using a mouse model of large hemispheric ischaemic stroke, we show that mild and brief intracranial pressure elevations (20 or 30 mmHg for just 3 min) potently trigger spreading depolarizations in ischaemic penumbra (4-fold increase in spreading depolarization occurrence). We also show that 30 mmHg intracranial pressure spikes as brief as 30 s are equally effective. In contrast, sustained intracranial pressure elevations to the same level for 30 min do not significantly increase the spreading depolarization rate, suggesting that an abrupt disturbance in the steady state equilibrium is required to trigger a spreading depolarization. Laser speckle flowmetry consistently showed a reduction in tissue perfusion, and two-photon pO2 microscopy revealed a drop in venous pO2 during the intracranial pressure spikes suggesting increased oxygen extraction fraction, and therefore, worsening supply-demand mismatch. These haemodynamic changes during intracranial pressure spikes were associated with highly reproducible increases in extracellular potassium levels in penumbra. Consistent with the experimental data, a higher rate of intracranial pressure spikes was associated with spreading depolarization clusters in a retrospective series of patients with aneurysmal subarachnoid haemorrhage with strong temporal correspondence. Altogether, our data show that intracranial pressure spikes, even when mild and brief, are capable of triggering spreading depolarizations. Aggressive prevention of intracranial pressure spikes may help reduce spreading depolarization occurrence and improve outcomes after brain injury.
Collapse
Affiliation(s)
- Fumiaki Oka
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02129, USA,Department of Neurosurgery, Yamaguchi Graduate School of Medicine, Ube, Yamaguchi, 755-8505, Japan,Correspondence to: Fumiaki Oka, MD, PhD Department of Neurosurgery, Yamaguchi Graduate School of Medicine 1-1-1, Minami-Kogushi, Ube, Yamaguchi, 755-8505, Japan E-mail:
| | - Homa Sadeghian
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02129, USA
| | - Mohammad A Yaseen
- Optics Division, MGH/MIT/HMS Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02129, USA
| | - Buyin Fu
- Optics Division, MGH/MIT/HMS Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02129, USA
| | - Sreekanth Kura
- Optics Division, MGH/MIT/HMS Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02129, USA
| | - Tao Qin
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02129, USA
| | - Sava Sakadžić
- Optics Division, MGH/MIT/HMS Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02129, USA
| | - Kazutaka Sugimoto
- Department of Neurosurgery, Yamaguchi Graduate School of Medicine, Ube, Yamaguchi, 755-8505, Japan
| | - Takao Inoue
- Department of Advanced ThermoNeuroBiology, Yamaguchi Graduate School of Medicine, Ube, Yamaguchi, 755-8505, Japan
| | - Hideyuki Ishihara
- Department of Neurosurgery, Yamaguchi Graduate School of Medicine, Ube, Yamaguchi, 755-8505, Japan
| | - Sadahiro Nomura
- Department of Neurosurgery, Yamaguchi Graduate School of Medicine, Ube, Yamaguchi, 755-8505, Japan
| | - Michiyasu Suzuki
- Department of Advanced ThermoNeuroBiology, Yamaguchi Graduate School of Medicine, Ube, Yamaguchi, 755-8505, Japan
| | - Cenk Ayata
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02129, USA,Stroke Service, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02129, USA,Correspondence may also be addressed to: Cenk Ayata, MD, PhD Massachusetts General Hospital, 149 13th street, Room 6408, Charlestown, MA 02129, USA E-mail:
| |
Collapse
|
12
|
Aykan SA, Xie H, Lai JH, Zheng Y, Chung DY, Kura S, Anzabi M, Sugimoto K, McAllister LM, Yaseen MA, Boas DA, Whalen MJ, Sakadzic S, Ayata C. Focal Subcortical White Matter Lesions Disrupt Resting State Cortical Interhemispheric Functional Connectivity in Mice. Cereb Cortex 2021; 31:4958-4969. [PMID: 34037216 PMCID: PMC8491690 DOI: 10.1093/cercor/bhab134] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 04/24/2021] [Accepted: 04/25/2021] [Indexed: 02/07/2023] Open
Abstract
The corpus callosum is the largest white matter tract and critical for interhemispheric connectivity. Unfortunately, neurocognitive deficits after experimental white matter lesions are subtle and variable, limiting their translational utility. We examined resting state functional connectivity (RSFC) as a surrogate after a focal lesion in the lateral corpus callosum induced by stereotaxic injection of L-NIO in mice. RSFC was performed via optical intrinsic signal imaging through intact skull before and on days 1 and 14 after injection, using interhemispheric homotopic and seed-based temporal correlation maps. We measured the lesion volumes at 1 month in the same cohort. L-NIO induced focal lesions in the corpus callosum. Interhemispheric homotopic connectivity decreased by up to 50% 24 h after L-NIO, partially sparing the visual cortex. All seeds showed loss of connectivity to the contralateral hemisphere. Moreover, ipsilesional motor and visual cortices lost connectivity within the same hemisphere. Sham-operated mice did not show any lesion or connectivity changes. RSFC imaging reliably detects acute disruption of long interhemispheric and intrahemispheric connectivity after a corpus callosum lesion in mice. This noninvasive method can be a functional surrogate to complement neurocognitive testing in both therapeutic and recovery studies after white matter injury.
Collapse
Affiliation(s)
- Sanem A Aykan
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston 02129, USA
| | - Hongyu Xie
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston 02129, USA.,Department of Rehabilitation, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - James Han Lai
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston 02129, USA
| | - Yi Zheng
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston 02129, USA
| | - David Y Chung
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston 02129, USA.,Division of Neurocritical Care, Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Sreekanth Kura
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Maryam Anzabi
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston 02129, USA
| | - Kazutaka Sugimoto
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston 02129, USA
| | - Lauren M McAllister
- Department of Pediatric Neurology, Yale New Haven Hospital, Connecticut 06510, USA
| | - M Abbas Yaseen
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA
| | - David A Boas
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA.,Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Michael J Whalen
- Neuroscience Center, Massachusetts General Hospital, Charlestown, MA 02129, USA
| | - Sava Sakadzic
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Cenk Ayata
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston 02129, USA.,Stroke Service, Department of Neurology, Massachusetts General Hospital, Boston, MA 02215, USA
| |
Collapse
|
13
|
Chung DY, Oka F, Jin G, Harriott A, Kura S, Aykan SA, Qin T, Edmiston WJ, Lee H, Yaseen MA, Sakadžić S, Boas DA, Whalen MJ, Ayata C. Subarachnoid hemorrhage leads to early and persistent functional connectivity and behavioral changes in mice. J Cereb Blood Flow Metab 2021; 41:975-985. [PMID: 32936728 PMCID: PMC8054726 DOI: 10.1177/0271678x20940152] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Aneurysmal subarachnoid hemorrhage (SAH) leads to significant long-term cognitive deficits, which can be associated with alterations in resting state functional connectivity (RSFC). However, modalities such as fMRI-which is commonly used to assess RSFC in humans-have practical limitations in small animals. Therefore, we used non-invasive optical intrinsic signal imaging to determine the effect of SAH on RSFC in mice up to three months after prechiasmatic blood injection. We assessed Morris water maze (MWM), open field test (OFT), Y-maze, and rotarod performance from approximately two weeks to three months after SAH. Compared to sham, we found that SAH reduced motor, retrosplenial, and visual seed-based connectivity indices. These deficits persisted in retrosplenial and visual cortex seeds at three months. Seed-to-seed analysis confirmed early attenuation of correlation coefficients in SAH mice, which persisted in predominantly posterior network connections at later time points. Seed-independent global and interhemispheric indices of connectivity revealed decreased correlations following SAH for at least one month. SAH led to MWM hidden platform and OFT deficits at two weeks, and Y-maze deficits for at least three months, without altering rotarod performance. In conclusion, experimental SAH leads to early and persistent alterations both in hemodynamically derived measures of RSFC and in cognitive performance.
Collapse
Affiliation(s)
- David Y Chung
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA.,Division of Neurocritical Care, Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
| | - Fumiaki Oka
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA.,Department of Neurosurgery, Yamaguchi University School of Medicine, Ube, Japan
| | - Gina Jin
- Department of Pediatrics, Massachusetts General Hospital, Boston, MA, USA
| | - Andrea Harriott
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA.,Stroke Service, Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
| | - Sreekanth Kura
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Sanem A Aykan
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Tao Qin
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA
| | - William J Edmiston
- Department of Pediatrics, Massachusetts General Hospital, Boston, MA, USA
| | - Hang Lee
- Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Mohammad A Yaseen
- Department of Bioengineering, Northeastern University, Boston, MA, USA.,Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Sava Sakadžić
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA
| | - David A Boas
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Michael J Whalen
- Department of Pediatrics, Massachusetts General Hospital, Boston, MA, USA
| | - Cenk Ayata
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA.,Stroke Service, Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
| |
Collapse
|
14
|
Hartung G, Badr S, Mihelic S, Dunn A, Cheng X, Kura S, Boas DA, Kleinfeld D, Alaraj A, Linninger AA. Mathematical synthesis of the cortical circulation for the whole mouse brain-part II: Microcirculatory closure. Microcirculation 2021; 28:e12687. [PMID: 33615601 DOI: 10.1111/micc.12687] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [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: 10/30/2020] [Revised: 12/23/2020] [Accepted: 02/10/2021] [Indexed: 11/29/2022]
Abstract
Recent advancements in multiphoton imaging and vascular reconstruction algorithms have increased the amount of data on cerebrovascular circulation for statistical analysis and hemodynamic simulations. Experimental observations offer fundamental insights into capillary network topology but mainly within a narrow field of view typically spanning a small fraction of the cortical surface (less than 2%). In contrast, larger-resolution imaging modalities, such as computed tomography (CT) or magnetic resonance imaging (MRI), have whole-brain coverage but capture only larger blood vessels, overlooking the microscopic capillary bed. To integrate data acquired at multiple length scales with different neuroimaging modalities and to reconcile brain-wide macroscale information with microscale multiphoton data, we developed a method for synthesizing hemodynamically equivalent vascular networks for the entire cerebral circulation. This computational approach is intended to aid in the quantification of patterns of cerebral blood flow and metabolism for the entire brain. In part I, we described the mathematical framework for image-guided generation of synthetic vascular networks covering the large cerebral arteries from the circle of Willis through the pial surface network leading back to the venous sinuses. Here in part II, we introduce novel procedures for creating microcirculatory closure that mimics a realistic capillary bed. We demonstrate our capability to synthesize synthetic vascular networks whose morphometrics match empirical network graphs from three independent state-of-the-art imaging laboratories using different image acquisition and reconstruction protocols. We also successfully synthesized twelve vascular networks of a complete mouse brain hemisphere suitable for performing whole-brain blood flow simulations. Synthetic arterial and venous networks with microvascular closure allow whole-brain hemodynamic predictions. Simulations across all length scales will potentially illuminate organ-wide supply and metabolic functions that are inaccessible to models reconstructed from image data with limited spatial coverage.
Collapse
Affiliation(s)
- Grant Hartung
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Shoale Badr
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Samuel Mihelic
- Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas, USA
| | - Andrew Dunn
- Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas, USA
| | - Xiaojun Cheng
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, USA
| | - Sreekanth Kura
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, USA
| | - David A Boas
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, USA
| | - David Kleinfeld
- Department of Physics, University of California San Diego, San Diego, California, USA
| | - Ali Alaraj
- Department of Neurosurgery, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Andreas A Linninger
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois, USA.,Department of Neurosurgery, University of Illinois at Chicago, Chicago, Illinois, USA
| |
Collapse
|
15
|
Erdener ŞE, Tang J, Kılıç K, Postnov D, Giblin JT, Kura S, Chen ICA, Vayisoğlu T, Sakadžić S, Schaffer CB, Boas DA. Dynamic capillary stalls in reperfused ischemic penumbra contribute to injury: A hyperacute role for neutrophils in persistent traffic jams. J Cereb Blood Flow Metab 2021; 41:236-252. [PMID: 32237951 PMCID: PMC8370003 DOI: 10.1177/0271678x20914179] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Ever since the introduction of thrombolysis and the subsequent expansion of endovascular treatments for acute ischemic stroke, it remains to be identified why the actual outcomes are less favorable despite recanalization. Here, by high spatio-temporal resolution imaging of capillary circulation in mice, we introduce the pathological phenomenon of dynamic flow stalls in cerebral capillaries, occurring persistently in salvageable penumbra after reperfusion. These stalls, which are different from permanent cellular plugs of no-reflow, were temporarily and repetitively occurring in the capillary network, impairing the overall circulation like small focal traffic jams. In vivo microscopy in the ischemic penumbra revealed leukocytes traveling slowly through capillary lumen or getting stuck, while red blood cell flow was being disturbed in the neighboring segments under reperfused conditions. Stall dynamics could be modulated, by injection of an anti-Ly6G antibody specifically targeting neutrophils. Decreased number and duration of stalls were associated with improvement in penumbral blood flow within 2-24 h after reperfusion along with increased capillary oxygenation, decreased cellular damage and improved functional outcome. Thereby, dynamic microcirculatory stall phenomenon can be a contributing factor to ongoing penumbral injury and is a potential hyperacute mechanism adding on previous observations of detrimental effects of activated neutrophils in ischemic stroke.
Collapse
Affiliation(s)
- Şefik E Erdener
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA.,Optics Division, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Jianbo Tang
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA.,Optics Division, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Kıvılcım Kılıç
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Dmitry Postnov
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA.,Institute of Biomedical Sciences, Faculty of Health and Medical Sciences, Copenhagen University, Copenhagen, Denmark
| | - John T Giblin
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Sreekanth Kura
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - I-Chun A Chen
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Tuğberk Vayisoğlu
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Sava Sakadžić
- Optics Division, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Chris B Schaffer
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - David A Boas
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| |
Collapse
|
16
|
Tahir W, Kura S, Zhu J, Cheng X, Damseh R, Tadesse F, Seibel A, Lee BS, Lesage F, Sakadžic S, Boas DA, Tian L. Anatomical Modeling of Brain Vasculature in Two-Photon Microscopy by Generalizable Deep Learning. BME Frontiers 2021. [DOI: 10.34133/2021/8620932] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Objective and Impact Statement. Segmentation of blood vessels from two-photon microscopy (2PM) angiograms of brains has important applications in hemodynamic analysis and disease diagnosis. Here, we develop a generalizable deep learning technique for accurate 2PM vascular segmentation of sizable regions in mouse brains acquired from multiple 2PM setups. The technique is computationally efficient, thus ideal for large-scale neurovascular analysis. Introduction. Vascular segmentation from 2PM angiograms is an important first step in hemodynamic modeling of brain vasculature. Existing segmentation methods based on deep learning either lack the ability to generalize to data from different imaging systems or are computationally infeasible for large-scale angiograms. In this work, we overcome both these limitations by a method that is generalizable to various imaging systems and is able to segment large-scale angiograms. Methods. We employ a computationally efficient deep learning framework with a loss function that incorporates a balanced binary-cross-entropy loss and total variation regularization on the network’s output. Its effectiveness is demonstrated on experimentally acquired in vivo angiograms from mouse brains of dimensions up to 808×808×702 μm. Results. To demonstrate the superior generalizability of our framework, we train on data from only one 2PM microscope and demonstrate high-quality segmentation on data from a different microscope without any network tuning. Overall, our method demonstrates 10× faster computation in terms of voxels-segmented-per-second and 3× larger depth compared to the state-of-the-art. Conclusion. Our work provides a generalizable and computationally efficient anatomical modeling framework for brain vasculature, which consists of deep learning-based vascular segmentation followed by graphing. It paves the way for future modeling and analysis of hemodynamic response at much greater scales that were inaccessible before.
Collapse
Affiliation(s)
- Waleed Tahir
- Department of Electrical and Computer Engineering, Boston University, Boston, MA, USA
| | - Sreekanth Kura
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Jiabei Zhu
- Department of Electrical and Computer Engineering, Boston University, Boston, MA, USA
| | - Xiaojun Cheng
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Rafat Damseh
- Biomedical Engineering Institute, École Polytechnique de Montréal, Montréal, QC, Canada
| | - Fetsum Tadesse
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Alex Seibel
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Blaire S. Lee
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Frédéric Lesage
- Biomedical Engineering Institute, École Polytechnique de Montréal, Montréal, QC, Canada
| | - Sava Sakadžic
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, USA
| | - David A. Boas
- Department of Electrical and Computer Engineering, Boston University, Boston, MA, USA
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
- Neurophotonics Center, Boston University, Boston, MA, USA
| | - Lei Tian
- Department of Electrical and Computer Engineering, Boston University, Boston, MA, USA
- Neurophotonics Center, Boston University, Boston, MA, USA
| |
Collapse
|
17
|
Sunil S, Evren Erdener S, Cheng X, Kura S, Tang J, Jiang J, Karrobi K, Kılıç K, Roblyer D, Boas DA. Stroke core revealed by tissue scattering using spatial frequency domain imaging. Neuroimage Clin 2020; 29:102539. [PMID: 33385882 PMCID: PMC7779322 DOI: 10.1016/j.nicl.2020.102539] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 12/14/2020] [Accepted: 12/15/2020] [Indexed: 12/26/2022]
Abstract
We present OCT and SFDI as methods to measure the spatial extent of stroke in mice. OCT was a reliable predictor of the stroke core in a photothrombosis stroke model. SFDI scattering coefficient spatially overlaps with OCT attenuation after stroke. Scattering increases following stroke reliably predict ischemic injury. SFDI provides a wide-field optical approach to map the stroke core.
Ischemic stroke leads to a reduction or complete loss of blood supply causing injury to brain tissue, which ultimately leads to behavioral impairment. Optical techniques are widely used to study the structural and functional changes that result as a consequence of ischemic stroke both in the acute and chronic phases of stroke recovery. It is currently a challenge to accurately estimate the spatial extent of the infarct without the use of histological parameters however, and in order to follow recovery mechanisms longitudinally at the mesoscopic scale it is essential to know the spatial extent of the stroke core. In this paper we first establish optical coherence tomography (OCT) as a reliable indicator of the stroke core by analyzing signal attenuation and spatially correlating it with the infarct, determined by staining with triphenyl-tetrazolium chloride (TTC). We then introduce spatial frequency domain imaging (SFDI) as a mesoscopic optical technique that can be used to accurately measure the infarct spatial extent by exploiting changes in optical scattering that occur as a consequence of ischemic stroke. Additionally, we follow the progression of ischemia through the acute and sub-acute phases of stroke recovery using both OCT and SFDI and show a consistently high spatial overlap in estimating infarct location. The use of SFDI in assessing infarct location will allow longitudinal studies targeted at following functional recovery mechanisms on a mesoscopic level without having to sacrifice the mouse acutely.
Collapse
Affiliation(s)
- Smrithi Sunil
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA.
| | - Sefik Evren Erdener
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA; Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Xiaojun Cheng
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Sreekanth Kura
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Jianbo Tang
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - John Jiang
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Kavon Karrobi
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Kıvılcım Kılıç
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Darren Roblyer
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA; Department of Electrical and Computer Engineering, Boston University, Boston, MA 02215, USA
| | - David A Boas
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA; Department of Electrical and Computer Engineering, Boston University, Boston, MA 02215, USA
| |
Collapse
|
18
|
Tahir W, Kura S, Zhu J, Cheng X, Damseh R, Tadesse F, Seibel A, Lee BS, Lesage F, Sakadžic S, Boas DA, Tian L. Anatomical Modeling of Brain Vasculature in Two-Photon Microscopy by Generalizable Deep Learning. BME Front 2020; 2020:8620932. [PMID: 37849965 PMCID: PMC10521669 DOI: 10.34133/2020/8620932] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Accepted: 11/12/2020] [Indexed: 10/19/2023] Open
Abstract
Objective and Impact Statement. Segmentation of blood vessels from two-photon microscopy (2PM) angiograms of brains has important applications in hemodynamic analysis and disease diagnosis. Here, we develop a generalizable deep learning technique for accurate 2PM vascular segmentation of sizable regions in mouse brains acquired from multiple 2PM setups. The technique is computationally efficient, thus ideal for large-scale neurovascular analysis. Introduction. Vascular segmentation from 2PM angiograms is an important first step in hemodynamic modeling of brain vasculature. Existing segmentation methods based on deep learning either lack the ability to generalize to data from different imaging systems or are computationally infeasible for large-scale angiograms. In this work, we overcome both these limitations by a method that is generalizable to various imaging systems and is able to segment large-scale angiograms. Methods. We employ a computationally efficient deep learning framework with a loss function that incorporates a balanced binary-cross-entropy loss and total variation regularization on the network's output. Its effectiveness is demonstrated on experimentally acquired in vivo angiograms from mouse brains of dimensions up to 808 × 808 × 702 μ m . Results. To demonstrate the superior generalizability of our framework, we train on data from only one 2PM microscope and demonstrate high-quality segmentation on data from a different microscope without any network tuning. Overall, our method demonstrates 10× faster computation in terms of voxels-segmented-per-second and 3× larger depth compared to the state-of-the-art. Conclusion. Our work provides a generalizable and computationally efficient anatomical modeling framework for brain vasculature, which consists of deep learning-based vascular segmentation followed by graphing. It paves the way for future modeling and analysis of hemodynamic response at much greater scales that were inaccessible before.
Collapse
Affiliation(s)
- Waleed Tahir
- Department of Electrical and Computer Engineering, Boston University, Boston, MA, USA
| | - Sreekanth Kura
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Jiabei Zhu
- Department of Electrical and Computer Engineering, Boston University, Boston, MA, USA
| | - Xiaojun Cheng
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Rafat Damseh
- Biomedical Engineering Institute, École Polytechnique de Montréal, Montréal, QC, Canada
| | - Fetsum Tadesse
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Alex Seibel
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Blaire S. Lee
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Frédéric Lesage
- Biomedical Engineering Institute, École Polytechnique de Montréal, Montréal, QC, Canada
| | - Sava Sakadžic
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, USA
| | - David A. Boas
- Department of Electrical and Computer Engineering, Boston University, Boston, MA, USA
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
- Neurophotonics Center, Boston University, Boston, MA, USA
| | - Lei Tian
- Department of Electrical and Computer Engineering, Boston University, Boston, MA, USA
- Neurophotonics Center, Boston University, Boston, MA, USA
| |
Collapse
|
19
|
Bordoni L, Li B, Kura S, Boas DA, Sakadžić S, Østergaard L, Frische S, Gutiérrez-Jiménez E. Quantification of Capillary Perfusion in an Animal Model of Acute Intracranial Hypertension. J Neurotrauma 2020; 38:446-454. [PMID: 32998634 DOI: 10.1089/neu.2019.6901] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Intracranial hypertension (IH) is a common feature of many pathologies, including brain edema. In the brain, the extended network of capillaries ensures blood flow to meet local metabolic demands. Capillary circulation may be severely affected by IH, but no studies have quantified the effect of intracranial pressure (ICP) and cerebral perfusion pressure (CPP) on capillary perfusion during the development of brain edema. We used optical coherence tomography angiography to quantify relative changes of fractional perfused volume (FPV) in cortical capillaries and simultaneously monitored ICP and blood pressure (BP) in anesthetized male C57Bl/6NTac mice during development of brain edema induced by water intoxication (WI) within 30 min. WI induced severe IH and brain herniation. ICP and CPP reached 90.2 mm Hg and 38.4 mm Hg, respectively. FPV was significantly affected already at normal ICP (ICP <15 mm Hg, slope ≈ -1.46, p < 0.001) and, at the onset of IH (ICP = 20-22 mm Hg), FPV was 17.9 ± 13.3% lower than baseline. A decreasing trend was observed until the ICP peak (Δ%FPV = -43.6 ± 19.2%). In the ICP range of 7-42 mm Hg, relative changes in FPV were significantly correlated with ICP, BP, and CPP (p < 0.001), with ICP and CPP being the best predictors. In conclusion, elevated ICP induces a gradual collapse of the cerebral microvasculature, which is initiated before the clinical threshold of IH. In summary, the estimate of capillary perfusion might be essential in patients with IH to assess the state of the brain microcirculation and to improve the availability of oxygen and nutrients to the brain.
Collapse
Affiliation(s)
- Luca Bordoni
- Institute of Biomedicine, Aarhus University, Aarhus C, Denmark
| | - Baoqiang Li
- Brain Cognition and Brain Disease Institute, Chinese Academy of Sciences, Shenzhen, China.,Shenzhen-Hong Kong Institute of Brain Science, Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - Sreekanth Kura
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, USA
| | - David A Boas
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, USA.,Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Sava Sakadžić
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Leif Østergaard
- Department of Clinical Medicine, Aarhus University, Aarhus C, Denmark.,Department of Neuroradiology, Aarhus University Hospital, Aarhus C, Denmark
| | | | | |
Collapse
|
20
|
Xie H, Chung DY, Kura S, Sugimoto K, Aykan SA, Wu Y, Sakadžić S, Yaseen MA, Boas DA, Ayata C. Differential effects of anesthetics on resting state functional connectivity in the mouse. J Cereb Blood Flow Metab 2020; 40:875-884. [PMID: 31092086 PMCID: PMC7168791 DOI: 10.1177/0271678x19847123] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [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: 02/15/2019] [Revised: 03/26/2019] [Accepted: 03/29/2019] [Indexed: 02/05/2023]
Abstract
Blood oxygen level-dependent (BOLD) functional MRI (fMRI) is a standard approach to examine resting state functional connectivity (RSFC), but fMRI in animal models is challenging. Recently, functional optical intrinsic signal imaging-which relies on the same hemodynamic signal underlying BOLD fMRI-has been developed as a complementary approach to assess RSFC in mice. Since it is difficult to ensure that an animal is in a truly resting state while awake, RSFC measurements under anesthesia remain an important approach. Therefore, we systematically examined measures of RSFC using non-invasive, widefield optical intrinsic signal imaging under five different anesthetics in male C57BL/6J mice. We find excellent seed-based, global, and interhemispheric connectivity using tribromoethanol (Avertin) and ketamine-xylazine, comparable to results in the literature including awake animals. Urethane anesthesia yielded intermediate results, while chloral hydrate and isoflurane were both associated with poor RSFC. Furthermore, we found a correspondence between the strength of RSFC and the power of low-frequency hemodynamic fluctuations. In conclusion, Avertin and ketamine-xylazine provide robust and reproducible measures of RSFC in mice, whereas chloral hydrate and isoflurane do not.
Collapse
Affiliation(s)
- Hongyu Xie
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA
- Department of Rehabilitation, Huashan Hospital, Fudan University, Shanghai, China
| | - David Y Chung
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA
- Division of Neurocritical Care, Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
| | - Sreekanth Kura
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Kazutaka Sugimoto
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA
- Department of Neurosurgery, Yamaguchi University School of Medicine, Ube, Japan
| | - Sanem A Aykan
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Yi Wu
- Department of Rehabilitation, Huashan Hospital, Fudan University, Shanghai, China
| | - Sava Sakadžić
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Mohammad A Yaseen
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA
| | - David A Boas
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Cenk Ayata
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA
- Stroke Service, Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
| |
Collapse
|
21
|
Sunil S, Erdener SE, Lee BS, Postnov D, Tang J, Kura S, Cheng X, Chen IA, Boas DA, Kılıç K. Awake chronic mouse model of targeted pial vessel occlusion via photothrombosis. Neurophotonics 2020; 7:015005. [PMID: 32042854 PMCID: PMC6992450 DOI: 10.1117/1.nph.7.1.015005] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 01/02/2020] [Indexed: 05/09/2023]
Abstract
Animal models of stroke are used extensively to study the mechanisms involved in the acute and chronic phases of recovery following stroke. A translatable animal model that closely mimics the mechanisms of a human stroke is essential in understanding recovery processes as well as developing therapies that improve functional outcomes. We describe a photothrombosis stroke model that is capable of targeting a single distal pial branch of the middle cerebral artery with minimal damage to the surrounding parenchyma in awake head-fixed mice. Mice are implanted with chronic cranial windows above one hemisphere of the brain that allow optical access to study recovery mechanisms for over a month following occlusion. Additionally, we study the effect of laser spot size used for occlusion and demonstrate that a spot size with small axial and lateral resolution has the advantage of minimizing unwanted photodamage while still monitoring macroscopic changes to cerebral blood flow during photothrombosis. We show that temporally guiding illumination using real-time feedback of blood flow dynamics also minimized unwanted photodamage to the vascular network. Finally, through quantifiable behavior deficits and chronic imaging we show that this model can be used to study recovery mechanisms or the effects of therapeutics longitudinally.
Collapse
Affiliation(s)
- Smrithi Sunil
- Boston University, Neurophotonics Center, Department of Biomedical Engineering, Boston, Massachusetts, United States
- Address all correspondence to Smrithi Sunil, E-mail:
| | - Sefik Evren Erdener
- Boston University, Neurophotonics Center, Department of Biomedical Engineering, Boston, Massachusetts, United States
- Hacettepe University, Institute of Neurological Sciences and Psychiatry, Ankara, Turkey
| | - Blaire S. Lee
- Boston University, Neurophotonics Center, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Dmitry Postnov
- Boston University, Neurophotonics Center, Department of Biomedical Engineering, Boston, Massachusetts, United States
- Copenhagen University, Department of Biomedical Sciences, Copenhagen, Denmark
| | - Jianbo Tang
- Boston University, Neurophotonics Center, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Sreekanth Kura
- Boston University, Neurophotonics Center, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Xiaojun Cheng
- Boston University, Neurophotonics Center, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Ichun Anderson Chen
- Boston University, Neurophotonics Center, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - David A. Boas
- Boston University, Neurophotonics Center, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Kıvılcım Kılıç
- Boston University, Neurophotonics Center, Department of Biomedical Engineering, Boston, Massachusetts, United States
| |
Collapse
|
22
|
Li B, Esipova TV, Sencan I, Kılıç K, Fu B, Desjardins M, Moeini M, Kura S, Yaseen MA, Lesage F, Østergaard L, Devor A, Boas DA, Vinogradov SA, Sakadžić S. More homogeneous capillary flow and oxygenation in deeper cortical layers correlate with increased oxygen extraction. eLife 2019; 8:42299. [PMID: 31305237 PMCID: PMC6636997 DOI: 10.7554/elife.42299] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 07/01/2019] [Indexed: 01/01/2023] Open
Abstract
Our understanding of how capillary blood flow and oxygen distribute across cortical layers to meet the local metabolic demand is incomplete. We addressed this question by using two-photon imaging of resting-state microvascular oxygen partial pressure (PO2) and flow in the whisker barrel cortex in awake mice. Our measurements in layers I-V show that the capillary red-blood-cell flux and oxygenation heterogeneity, and the intracapillary resistance to oxygen delivery, all decrease with depth, reaching a minimum around layer IV, while the depth-dependent oxygen extraction fraction is increased in layer IV, where oxygen demand is presumably the highest. Our findings suggest that more homogeneous distribution of the physiological observables relevant to oxygen transport to tissue is an important part of the microvascular network adaptation to local brain metabolism. These results will inform the biophysical models of layer-specific cerebral oxygen delivery and consumption and improve our understanding of the diseases that affect cerebral microcirculation.
Collapse
Affiliation(s)
- Baoqiang Li
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Tatiana V Esipova
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, United States.,Department of Chemistry, University of Pennsylvania, Philadelphia, United States
| | - Ikbal Sencan
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Kıvılcım Kılıç
- Department of Neurosciences, University of California, San Diego, La Jolla, United States
| | - Buyin Fu
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Michele Desjardins
- Department of Radiology, University of California, San Diego, La Jolla, United States
| | - Mohammad Moeini
- Institute of Biomedical Engineering, École Polytechnique de Montréal, Montréal, Canada.,Research Centre, Montreal Heart Institute, Montréal, Canada
| | - Sreekanth Kura
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Mohammad A Yaseen
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Frederic Lesage
- Institute of Biomedical Engineering, École Polytechnique de Montréal, Montréal, Canada.,Research Centre, Montreal Heart Institute, Montréal, Canada
| | - Leif Østergaard
- Center of Functionally Integrative Neuroscience and MINDLab, Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Anna Devor
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States.,Department of Neurosciences, University of California, San Diego, La Jolla, United States.,Department of Radiology, University of California, San Diego, La Jolla, United States
| | - David A Boas
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States.,Department of Biomedical Engineering, Boston University, Boston, United States
| | - Sergei A Vinogradov
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, United States.,Department of Chemistry, University of Pennsylvania, Philadelphia, United States
| | - Sava Sakadžić
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| |
Collapse
|
23
|
Erdener ŞE, Tang J, Sajjadi A, Kılıç K, Kura S, Schaffer CB, Boas DA. Spatio-temporal dynamics of cerebral capillary segments with stalling red blood cells. J Cereb Blood Flow Metab 2019; 39:886-900. [PMID: 29168661 PMCID: PMC6501506 DOI: 10.1177/0271678x17743877] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Optical coherence tomography (OCT) allows label-free imaging of red blood cell (RBC) flux within capillaries with high spatio-temporal resolution. In this study, we utilized time-series OCT-angiography to demonstrate interruptions in capillary RBC flux in mouse brain in vivo. We noticed ∼7.5% of ∼200 capillaries had at least one stall in awake mice with chronic windows during a 9-min recording. At any instant, ∼0.45% of capillaries were stalled. Average stall duration was ∼15 s but could last over 1 min. Stalls were more frequent and longer lasting in acute window preparations. Further, isoflurane anesthesia in chronic preparations caused an increase in the number of stalls. In repeated imaging, the same segments had a tendency to stall again over a period of one month. In awake animals, functional stimulation decreased the observance of stalling events. Stalling segments were located distally, away from the first couple of arteriolar-side capillary branches and their average RBC and plasma velocities were lower than nonstalling capillaries within the same region. This first systematic analysis of capillary RBC stalls in the brain, enabled by rapid and continuous volumetric imaging of capillaries with OCT-angiography, will lead to future investigations of the potential role of stalling events in cerebral pathologies.
Collapse
Affiliation(s)
- Şefik Evren Erdener
- 1 Optics Division, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Jianbo Tang
- 1 Optics Division, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Amir Sajjadi
- 1 Optics Division, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Kıvılcım Kılıç
- 2 Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Sreekanth Kura
- 1 Optics Division, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Chris B Schaffer
- 3 Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - David A Boas
- 1 Optics Division, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA.,2 Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| |
Collapse
|
24
|
Kura S, Xie H, Fu B, Ayata C, Boas DA, Sakadžić S. Intrinsic optical signal imaging of the blood volume changes is sufficient for mapping the resting state functional connectivity in the rodent cortex. J Neural Eng 2018; 15:035003. [PMID: 29451130 DOI: 10.1088/1741-2552/aaafe4] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
OBJECTIVE Resting state functional connectivity (RSFC) allows the study of functional organization in normal and diseased brain by measuring the spontaneous brain activity generated under resting conditions. Intrinsic optical signal imaging (IOSI) based on multiple illumination wavelengths has been used successfully to compute RSFC maps in animal studies. The IOSI setup complexity would be greatly reduced if only a single wavelength can be used to obtain comparable RSFC maps. APPROACH We used anesthetized mice and performed various comparisons between the RSFC maps based on single wavelength as well as oxy-, deoxy- and total hemoglobin concentration changes. MAIN RESULTS The RSFC maps based on IOSI at a single wavelength selected for sensitivity to the blood volume changes are quantitatively comparable to the RSFC maps based on oxy- and total hemoglobin concentration changes obtained by the more complex IOSI setups. Moreover, RSFC maps do not require CCD cameras with very high frame acquisition rates, since our results demonstrate that they can be computed from the data obtained at frame rates as low as 5 Hz. SIGNIFICANCE Our results will have general utility for guiding future RSFC studies based on IOSI and making decisions about the IOSI system designs.
Collapse
Affiliation(s)
- Sreekanth Kura
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, MGH/HMS/MIT Athinoula A Martinos Center for Biomedical Imaging, 149 13th Street, Charlestown, MA 02129, United States of America. Department of Biomedical Engineering, Neurophotonics Center, Boston University, 44 Cummington Mall, Boston, MA 02215, United States of America
| | | | | | | | | | | |
Collapse
|
25
|
von Bornstädt D, Houben T, Seidel JL, Zheng Y, Dilekoz E, Qin T, Sandow N, Kura S, Eikermann-Haerter K, Endres M, Boas DA, Moskowitz MA, Lo EH, Dreier JP, Woitzik J, Sakadžić S, Ayata C. Supply-demand mismatch transients in susceptible peri-infarct hot zones explain the origins of spreading injury depolarizations. Neuron 2015; 85:1117-31. [PMID: 25741731 DOI: 10.1016/j.neuron.2015.02.007] [Citation(s) in RCA: 135] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 11/01/2014] [Accepted: 01/23/2015] [Indexed: 11/28/2022]
Abstract
UNLABELLED Peri-infarct depolarizations (PIDs) are seemingly spontaneous spreading depression-like waves that negatively impact tissue outcome in both experimental and human stroke. Factors triggering PIDs are unknown. Here, we show that somatosensory activation of peri-infarct cortex triggers PIDs when the activated cortex is within a critical range of ischemia. We show that the mechanism involves increased oxygen utilization within the activated cortex, worsening the supply-demand mismatch. We support the concept by clinical data showing that mismatch predisposes stroke patients to PIDs as well. Conversely, transient worsening of mismatch by episodic hypoxemia or hypotension also reproducibly triggers PIDs. Therefore, PIDs are triggered upon supply-demand mismatch transients in metastable peri-infarct hot zones due to increased demand or reduced supply. Based on the data, we propose that minimizing sensory stimulation and hypoxic or hypotensive transients in stroke and brain injury would reduce PID incidence and their adverse impact on outcome. VIDEO ABSTRACT
Collapse
Affiliation(s)
- Daniel von Bornstädt
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 13(th) Street, 6408, Charlestown, MA 02129, USA; Department of Neurology, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany; Center for Stroke Research, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Thijs Houben
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 13(th) Street, 6408, Charlestown, MA 02129, USA; Department of Neurology, Leiden University Medical Center, Albinusdreef 2, 2300 RC Leiden, the Netherlands
| | - Jessica L Seidel
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 13(th) Street, 6408, Charlestown, MA 02129, USA
| | - Yi Zheng
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 13(th) Street, 6408, Charlestown, MA 02129, USA
| | - Ergin Dilekoz
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 13(th) Street, 6408, Charlestown, MA 02129, USA; Department of Pharmacology, Gazi University Faculty of Medicine, Besevler Campus, 06560 Ankara, Turkey
| | - Tao Qin
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 13(th) Street, 6408, Charlestown, MA 02129, USA
| | - Nora Sandow
- Department of Neurosurgery, Charité - Universitätsmedizin Augustenburger Platz 1, 13353 Berlin, Germany; Center for Stroke Research, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Sreekanth Kura
- Optics Division, MHG/MIT/HMS Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 13(th) Street, 6408, Charlestown, MA 02129, USA
| | - Katharina Eikermann-Haerter
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 13(th) Street, 6408, Charlestown, MA 02129, USA
| | - Matthias Endres
- Department of Neurology, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany; Center for Stroke Research, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany; German Center for Neurodegenerative Diseases (DZNE), Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany; German Centre for Cardiovascular Research (DZHK), Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - David A Boas
- Optics Division, MHG/MIT/HMS Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 13(th) Street, 6408, Charlestown, MA 02129, USA
| | - Michael A Moskowitz
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 13(th) Street, 6408, Charlestown, MA 02129, USA
| | - Eng H Lo
- Neuroprotection Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 13(th) Street, 6408, Charlestown, MA 02129, USA
| | - Jens P Dreier
- Department of Neurology, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany; Center for Stroke Research, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany; Department of Experimental Neurology, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Johannes Woitzik
- Department of Neurosurgery, Charité - Universitätsmedizin Augustenburger Platz 1, 13353 Berlin, Germany; Center for Stroke Research, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Sava Sakadžić
- Optics Division, MHG/MIT/HMS Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 13(th) Street, 6408, Charlestown, MA 02129, USA
| | - Cenk Ayata
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 13(th) Street, 6408, Charlestown, MA 02129, USA; Stroke Service and Neuroscience Intensive Care Unit, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, MA 02114, USA.
| |
Collapse
|
26
|
Kil KE, Zhu A, Zhang Z, Choi JK, Kura S, Gong C, Brownell AL. Development of [(123)I]IPEB and [(123)I]IMPEB as SPECT Radioligands for Metabotropic Glutamate Receptor Subtype 5. ACS Med Chem Lett 2014; 5:652-6. [PMID: 24944738 DOI: 10.1021/ml500007z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [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: 01/06/2014] [Accepted: 04/06/2014] [Indexed: 12/17/2022] Open
Abstract
mGlu5 play an important role in physiology and pathology to various central nervous system (CNS) diseases. Several positron emission tomography (PET) radiotracers have been developed to explore the role of mGlu5 in brain disorders. However, there are no single photon emission computed tomography (SPECT) radioligands for mGlu5. Here we report development of [(123)I]IPEB ([(123)I]1) and [(123)I]IMPEB ([(123)I]2) as mGlu5 radioligands for SPECT. [(123)I]1 and [(123)I]2 were produced by copper(I) mediated aromatic halide displacement reactions. The SPECT imaging using mouse models demonstrated that [(123)I]1 readily entered the brain and accumulated specifically in mGlu5-rich regions of the brain such as striatum and hippocampus. However, in comparison to the corresponding PET tracer [(18)F]FPEB, [(123)I]1 showed faster washout from the brain. The binding ratios of the striatum and the hippocampus compared to the cerebellum for [(123)I]1 and [(18)F]FPEB were similar despite unfavorable pharmacokinetics of [(123)I]1. Further structural optimization of 1 may lead to more viable SPECT radiotracers for the imaging of mGlu5.
Collapse
Affiliation(s)
- Kun-Eek Kil
- Athinoula A. Martinos Center
for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, Massachusetts 02129, United States
| | - Aijun Zhu
- Athinoula A. Martinos Center
for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, Massachusetts 02129, United States
| | - Zhaoda Zhang
- Athinoula A. Martinos Center
for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, Massachusetts 02129, United States
| | - Ji-Kyung Choi
- Athinoula A. Martinos Center
for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, Massachusetts 02129, United States
| | - Sreekanth Kura
- Athinoula A. Martinos Center
for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, Massachusetts 02129, United States
| | - Chunyu Gong
- Athinoula A. Martinos Center
for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, Massachusetts 02129, United States
| | - Anna-Liisa Brownell
- Athinoula A. Martinos Center
for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, Massachusetts 02129, United States
| |
Collapse
|
27
|
Guo Y, Yuan H, Claudio NM, Kura S, Shakerdge N, Mempel TR, Bacskai BJ, Josephson L. PEG-like nanoprobes: multimodal, pharmacokinetically and optically tunable nanomaterials. PLoS One 2014; 9:e95406. [PMID: 24781778 PMCID: PMC4004541 DOI: 10.1371/journal.pone.0095406] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 03/25/2014] [Indexed: 11/21/2022] Open
Abstract
“PEG-like Nanoprobes” (PN’s) are pharmacokinetically and optically tunable nanomaterials whose disposition in biological systems can be determined by fluorescence or radioactivity. PN’s feature a unique design where a single PEG polymer surrounds a short fluorochrome and radiometal bearing peptide, and endows the resulting nanoprobe with pharmacokinetic control (based on molecular weight of the PEG selected) and optical tunability (based on the fluorochrome selected), while the chelate provides a radiolabeling option. PN’s were used to image brain capillary angiography (intravital 2-photon microscopy), tumor capillary permeability (intravital fluorescent microscopy), and the tumor enhanced permeability and retention (EPR) effect (111In-PN and SPECT). Clinical applications of PN’s include use as long blood half-life fluorochromes for intraoperative angiography, for measurements of capillary permeability in breast cancer lesions, and to image EPR by SPECT, for stratifying patient candidates for long-circulating nanomedicines that may utilize the EPR mechanism.
Collapse
Affiliation(s)
- Yanyan Guo
- Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
| | - Hushan Yuan
- Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
| | - Natalie M. Claudio
- Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
| | - Sreekanth Kura
- Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
| | - Naomi Shakerdge
- Alzheimer Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, United States of America
| | - Thorsten R. Mempel
- Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
| | - Brian J. Bacskai
- Alzheimer Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, United States of America
| | - Lee Josephson
- Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
- Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
- * E-mail:
| |
Collapse
|
28
|
Ay I, Blasi F, Rietz TA, Rotile NJ, Kura S, Brownell AL, Day H, Oliveira BL, Looby RJ, Caravan P. In vivo molecular imaging of thrombosis and thrombolysis using a fibrin-binding positron emission tomographic probe. Circ Cardiovasc Imaging 2014; 7:697-705. [PMID: 24777937 DOI: 10.1161/circimaging.113.001806] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND Fibrin is a major component of arterial and venous thrombi and represents an ideal candidate for molecular imaging of thrombosis. Here, we describe imaging properties and target uptake of a new fibrin-specific positron emission tomographic probe for thrombus detection and therapy monitoring in 2 rat thrombosis models. METHODS AND RESULTS The fibrin-binding probe FBP7 was synthesized by conjugation of a known short cyclic peptide to a cross-bridged chelator (CB-TE2A), followed by labeling with copper-64. Adult male Wistar rats (n=26) underwent either carotid crush injury (mural thrombosis model) or embolic stroke (occlusive thrombosis model) followed by recombinant tissue-type plasminogen activator treatment (10 mg/kg, IV). FBP7 detected thrombus location in both animal models with a high positron emission tomographic target-to-background ratio that increased over time (>5-fold at 30-90 minutes, >15-fold at 240-285 minutes). In the carotid crush injury animals, biodistribution analysis confirmed high probe uptake in the thrombotic artery (≈0.5%ID/g; >5-fold greater than blood and other tissues of the head and thorax). Similar results were obtained from ex vivo autoradiography of the ipsilateral versus contralateral carotid arteries. In embolic stroke animals, positron emission tomographic-computed tomographic imaging localized the clot in the internal carotid/middle cerebral artery segment of all rats. Time-dependent reduction of activity at the level of the thrombus was detected in recombinant tissue-type plasminogen activator-treated rats but not in vehicle-injected animals. Brain autoradiography confirmed clot dissolution in recombinant tissue-type plasminogen activator-treated animals, but enduring high thrombus activity in control rats. CONCLUSIONS We demonstrated that FBP7 is suitable for molecular imaging of thrombosis and thrombolysis in vivo and represents a promising candidate for bench-to-bedside translation.
Collapse
Affiliation(s)
- Ilknur Ay
- From the Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA
| | - Francesco Blasi
- From the Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA
| | - Tyson A Rietz
- From the Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA
| | - Nicholas J Rotile
- From the Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA
| | - Sreekanth Kura
- From the Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA
| | - Anna Liisa Brownell
- From the Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA
| | - Helen Day
- From the Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA
| | - Bruno L Oliveira
- From the Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA
| | - Richard J Looby
- From the Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA
| | - Peter Caravan
- From the Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA.
| |
Collapse
|
29
|
Arsenault D, Zhu A, Gong C, Kil KE, Kura S, Choi JK, Brownell AL. Hypo-anxious phenotype of adolescent offspring prenatally exposed to LPS is associated with reduced mGluR5 expression in hippocampus. ACTA ACUST UNITED AC 2014; 3:202-211. [PMID: 25419490 DOI: 10.4236/ojmp.2014.33022] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Many studies have reported long-term modulation of metabotropic glutamate receptor 5 (mGluR5) by inflammatory processes and a pharmacological modulation of mGluR5 is known to regulate anxiety level. However, it is not known if non-pharmacological modulation of mGluR5 by inflammation impaired the unconditional level of anxiety. In this study, we investigated this relation in LPS prenatal immune challenge (120μg/kg, 3x i.p. injection in late gestation), a developmental model of neuroinflammation in which some studies have reported hypo-anxious phenotype. Using positron emission tomographic imaging (PET) approaches, we have demonstrated a decrease in the binding potential of [18F]fluoro-5-(2-pyridinylethynyl)benzonitrile ([18F]FPEB, a radioligand for mGluR5) in hippocampus of adolescent offspring prenatally exposed to LPS, without significant change in the binding of [11C]peripheral benzodiazepine receptor 28 ([11C]PBR28), an inflammatory marker. In addition, dark-light box emergence test revealed a lower level of anxiety in LPS-exposed offspring and this behavioural phenotype was associated with the binding potential of [18F]FPEB in hippocampus. These results confirm that neuroinflammation during developmental phase modulates the physiology of mGluR5 and this alteration can be associated with behavioural phenotype related to anxiety. In addition, this study supports a hypotheses that mGluR5 could be used as a diagnostic target in anxiety.
Collapse
Affiliation(s)
- Dany Arsenault
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 13 Street, Charlestown, Massachusetts 02129, USA
| | - Aijun Zhu
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 13 Street, Charlestown, Massachusetts 02129, USA
| | - Chunyu Gong
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 13 Street, Charlestown, Massachusetts 02129, USA
| | - Kun-Eek Kil
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 13 Street, Charlestown, Massachusetts 02129, USA
| | - Sreekanth Kura
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 13 Street, Charlestown, Massachusetts 02129, USA
| | - Ji-Kyung Choi
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 13 Street, Charlestown, Massachusetts 02129, USA
| | - Anna-Liisa Brownell
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 13 Street, Charlestown, Massachusetts 02129, USA
| |
Collapse
|
30
|
Kil KE, Zhang Z, Jokivarsi K, Gong C, Choi JK, Kura S, Brownell AL. Radiosynthesis of N-(4-chloro-3-[(11)C]methoxyphenyl)-2-picolinamide ([(11)C]ML128) as a PET radiotracer for metabotropic glutamate receptor subtype 4 (mGlu4). Bioorg Med Chem 2013; 21:5955-62. [PMID: 23978356 DOI: 10.1016/j.bmc.2013.07.046] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Revised: 07/17/2013] [Accepted: 07/27/2013] [Indexed: 11/18/2022]
Abstract
N-(Chloro-3-methoxyphenyl)-2-picolinamide (3, ML128, VU0361737) is an mGlu4 positive allosteric modulator (PAM), which is potent and centrally penetrating. 3 is also the first mGlu4 PAM to show efficacy in a preclinical Parkinson disease model upon systemic dosing. As a noninvasive medical imaging technique and a powerful tool in neurological research, positron emission tomography (PET) offers a possibility to investigate mGlu4 expression in vivo under physiologic and pathological conditions. We synthesized a carbon-11 labeled ML128 ([(11)C]3) as a PET radiotracer for mGlu4, and characterized its biological properties in Sprague Dawley rats. [(11)C]3 was synthesized from N-(4-chloro-3-hydroxyphenyl)-2-picolinamide (2) using [(11)C]CH3I. Total synthesis time was 38±2.2min (n=7) from the end of bombardment to the formulation. The radioligand [(11)C]3 was obtained in 27.7±5.3% (n=5) decay corrected radiochemical yield based on the radioactivity of [(11)C]CO2. The radiochemical purity of [(11)C]3 was >99%. Specific activity was 188.7±88.8GBq/mol (n=4) at the end of synthesis (EOS). PET images were conducted in 20 normal male Sprague Dawley rats including 11 control studies, 6 studies blocking with an mGlu4 modulator (4) to investigate specificity and 3 studies blocking with an mGlu5 modulator (MTEP) to investigate selectivity. These studies showed fast accumulation of [(11)C]3 (peak activity between 1-3min) in several brain areas including striatum, thalamus, hippocampus, cerebellum, and olfactory bulb following with fast washout. Blocking studies with the mGlu4 modulator 4 showed 22-28% decrease of [(11)C]3 accumulation while studies of selectivity showed only minor decrease supporting good selectivity over mGlu5. Biodistribution studies and blood analyses support fast metabolism. Altogether this is the first PET imaging ligand for mGlu4, in which the labeled ML128 was used for imaging its in vivo distribution and pharmacokinetics in brain.
Collapse
Affiliation(s)
- Kun-Eek Kil
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA 02129, United States
| | | | | | | | | | | | | |
Collapse
|
31
|
Sagata N, Iwaki A, Aramaki T, Takao K, Kura S, Tsuzuki T, Kawakami R, Ito I, Kitamura T, Sugiyama H, Miyakawa T, Fukumaki Y. Comprehensive behavioural study of GluR4 knockout mice: implication in cognitive function. Genes Brain Behav 2011; 9:899-909. [PMID: 20662939 DOI: 10.1111/j.1601-183x.2010.00629.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Fast excitatory transmission in the mammalian central nervous system is mediated by AMPA-type glutamate receptors. The tetrameric AMPA receptor complexes are composed of four subunits, GluR1-4. The GluR4 subunit is highly expressed in the cerebellum and the early postnatal hippocampus and is thought to be involved in synaptic plasticity and the development of functional neural circuitry through the recruitment of other AMPA receptor subunits. Previously, we reported an association of the human GluR4 gene (GRIA4) with schizophrenia. To examine the role of the GluR4 subunit in the higher brain function, we generated GluR4 knockout mice and conducted electrophysiological and behavioural analyses. The mutant mice showed normal long-term potentiation (LTP) in the CA1 region of the hippocampus. The GluR4 knockout mice showed mildly improved spatial working memory in the T-maze test. Although the retention of spatial reference memory was intact in the mutant mice, the acquisition of spatial reference memory was impaired in the Barnes circular maze test. The GluR4 knockout mice showed impaired prepulse inhibition. These results suggest the involvement of the GluR4 subunit in cognitive function.
Collapse
Affiliation(s)
- N Sagata
- Division of Human Molecular Genetics, Research Center for Genetic Information, Medical Institute of Bioregulation, Kyushu University, Higashi-ku, Fukuoka, Japan
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Haiping Z, Takayama K, Uchino J, Harada A, Adachi Y, Kura S, Caicun Z, Tsuzuki T, Nakanishi Y. Prevention of radiation-induced pneumonitis by recombinant adenovirus-mediated transferring of soluble TGF-β type II receptor gene. Cancer Gene Ther 2006; 13:864-72. [PMID: 16710346 DOI: 10.1038/sj.cgt.7700959] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
To investigate whether radiation-induced pneumonitis in the mouse-irradiated lung could be prevented by recombinant adenovirus-mediated soluble transforming growth factor-beta (TGF-beta) type II receptor gene therapy. Radiation fibrosis-prone mice (C57BL/6J) were randomly divided into four groups consisting of a (1) control group (sham-irradiated); (2) radiation (RT)-alone group; (3) RT+AdCMVsTbetaR group and (4) RT+AdCMVluc group. The RT-alone and sham-irradiated mice were killed at several time points after thoracic irradiation with a single dose of 9 Gy, and then the TGF-beta1 concentrations in serum and broncho-alveolar lavage fluid (BALF) were quantified by enzyme-linked immunosorbent assay (ELISA). We used an adenoviral vector expressing a soluble TGF-beta type II receptor (AdCMVsTbetaR), which can bind to TGF-beta and then block the TGF-beta receptor-mediated signal transduction. The C57BL/6J mice were intraperitoneally (i.p.) injected with either 5 x 10(8) plaque-forming units of AdCMVsTbetaR or AdCMVluc, a control adenovirus-expressing luciferase, a week preceding and a week following the X-ray thoracic irradiation. Four weeks after irradiation, the mice were killed and the concentration of TGF-beta1 in the serum and BALF were then measured using ELISA and the lung tissue specimens were examined histopathologically. Following thoracic irradiation with a single dose of 9 Gy, radiation-induced TGF-beta1 release in the serum reached the first peak concentration at 12 h and then declined. It reached a maximal value at 2 weeks after irradiation. In the BALF, the TGF-beta1 concentration was appreciable within the first hour and thereafter declined. It reached a maximal value at 3 days after irradiation. A one-time i.p. injection of AdCMVsTbetaR 1 week before irradiation could not completely suppress the two peaks of the radiation-induced TGF-beta1 increase, whereas an injection a week preceding and a week following thoracic irradiation was able to suppress those two peaks thoroughly. The TGF-beta1 was completely suppressed in the AdCMVsTbetaR-treated mouse serum and BALF; however, no statistical difference was observed in the serum and BALF between the AdCMVluc-infected mice and the control mice at 4 weeks after irradiation (P < 0.05). A histopathological examination showed only mild radiation pneumonitis in the irradiated lungs of AdCMVsTbetaR-treated mice in comparison to the AdCMVluc-infected and RT-alone mice. Our results demonstrated that TGF-beta1 plays an important role in radiation pneumonitis, thus suggesting that the adenovirus-mediated overexpression in soluble TGF-beta type II receptor gene therapy may be a potentially feasible and effective strategy for the prevention of radiation pneumonitis.
Collapse
Affiliation(s)
- Z Haiping
- Research Institute for Diseases of the Chest, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Qiao H, Hisatomi T, Sonoda KH, Kura S, Sassa Y, Kinoshita S, Nakamura T, Sakamoto T, Ishibashi T. The characterisation of hyalocytes: the origin, phenotype, and turnover. Br J Ophthalmol 2005; 89:513-7. [PMID: 15774935 PMCID: PMC1772586 DOI: 10.1136/bjo.2004.050658] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIM To determine the characterisation of hyalocytes: the origin, phenotype, and turnover in the rodent. METHODS To characterise the ultrastructure and distribution of hyalocytes, transmission and scanning electron microscopy was performed in rat eyes. Immunophenotypical analysis was performed by either anti-ED1 or ED2 antibodies. To examine the origin of the hyalocytes, the chimeric mice were created and were used to transplant the bone marrow (BM) cells from enhanced green fluorescent protein (EGFP) transgenic mice. The turnover of hyalocytes was examined at 0, 4, 6, 7, and 12 months after BM transplantation. RESULTS Hyalocytes were distributed especially in the vitreous cortex and had an irregular shape with a spherical granule. Immunophenotypical studies demonstrated that most of the hyalocytes in rat eyes expressed ED2 but not ED1. In the chimeric mice, the hyalocytes were GFP negative right after BM transplantation. Interestingly, more than 60% of hyalocytes were replaced within 4 months and approximately 90% within 7 months after BM transplantation. CONCLUSIONS The rodent hyalocytes were shown to express tissue macrophage marker, were derived from BM, and totally replaced within 7 months. These data provide the characterisation of hyalocytes in physiological conditions, especially their origin, distribution, and turnover, and may contribute to the better understanding of the pathogenesis of vitreoretinal disease.
Collapse
Affiliation(s)
- H Qiao
- Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Iga F, Tsubota M, Sawada M, Huang HB, Kura S, Takemura M, Yaji K, Nagira M, Kimura A, Jo T, Takabatake T, Namatame H, Taniguchi M. Determination of the orbital polarization in YTiO3 by using soft X-ray linear dichroism. Phys Rev Lett 2004; 93:257207. [PMID: 15697937 DOI: 10.1103/physrevlett.93.257207] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2004] [Indexed: 05/24/2023]
Abstract
We report measurements of linear dichroism in x-ray absorption at Ti L(2,3) edges of a Mott-insulating ferromagnet YTiO3, where orbital ordering occurs in the triply degenerate Ti 3d t(2g) states. Dichroic spectra and their integrated intensities are obtained for the incident electric field with polarizations parallel to a, b, and c axes. The comparison of the spectra with atomic multiplet calculations removes the ambiguity about the orbital polarization, i.e., the relative weights of |xy>, |yz>, and |zx> orbits, which are crucial for the origin of ferromagnetism. The result is consistent with the previous analysis of nuclear magnetic resonance in the Mizokawa-Fujimori scheme.
Collapse
Affiliation(s)
- F Iga
- Department of Quantum Matter, ADSM, Hiroshima University, Higashi-Hiroshima, 739-8530, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Tsuzuki T, Egashira A, Igarashi H, Iwakuma T, Nakatsuru Y, Tominaga Y, Kawate H, Nakao K, Nakamura K, Ide F, Kura S, Nakabeppu Y, Katsuki M, Ishikawa T, Sekiguchi M. Spontaneous tumorigenesis in mice defective in the MTH1 gene encoding 8-oxo-dGTPase. Proc Natl Acad Sci U S A 2001; 98:11456-61. [PMID: 11572992 PMCID: PMC58751 DOI: 10.1073/pnas.191086798] [Citation(s) in RCA: 232] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Oxygen radicals, which can be produced through normal cellular metabolism, are thought to play an important role in mutagenesis and tumorigenesis. Among various classes of oxidative DNA damage, 8-oxo-7,8-dihydroguanine (8-oxoG) is most important because of its abundance and mutagenicity. The MTH1 gene encodes an enzyme that hydrolyzes 8-oxo-dGTP to monophosphate in the nucleotide pool, thereby preventing occurrence of transversion mutations. By means of gene targeting, we have established MTH1 gene-knockout cell lines and mice. When examined 18 months after birth, a greater number of tumors were formed in the lungs, livers, and stomachs of MTH1-deficient mice, as compared with wild-type mice. The MTH1-deficient mouse will provide a useful model for investigating the role of the MTH1 protein in normal conditions and under oxidative stress.
Collapse
Affiliation(s)
- T Tsuzuki
- Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Abstract
Oxidative DNA damage is thought to contribute to carcinogenesis, ageing, and neurological degeneration. Further, the cumulative risk of cancer increases dramatically with age in humans. In general terms, cancer can be regarded as a degenerative disease of ageing. There is evidence for the accumulation of oxidative DNA damage with age based on studies mainly measuring an increase in 8-oxoguanine. 8-Oxo-7,8-dihydro-2'-deoxyguanosine 5'-triphosphate (8-oxo-dGTP) is formed in the nucleotide pool of a cell during normal cellular metabolism. When 8-oxoguanine is incorporated into DNA causes mutation. Organisms possess 8-oxo-dGTPase, an enzyme that specifically degrades 8-oxo-dGTP to 8-oxo-dGMP. To analyze the function of MTH1 with 8-oxo-dGTPase activity in vivo, we generated a mouse line carrying a mutant MTH1 allele created by targeted gene disruption. MTH1 homozygous mutant mice were found to have a physically normal appearance, but seemed to have lost 8-oxo-dGTPase activity in liver extracts. When we examined the susceptibility of the mutant mice to spontaneous tumorigenesis, no significant difference was observed in survival rate of MTH1+/+ and MTH1-/- mice. However, pathological examination revealed a statistically significant difference in the incidence of tumors. More tumors were formed in lungs, livers, and stomachs of MTH1-/- mice than in those of the wild type mice. These studies with MTH1-null mutant mice provided an important insight into the role of this nucleotide sanitization enzyme in terms of the spontaneous tumorigenesis as well as mutagenesis caused by the oxygen-induced DNA damage.
Collapse
Affiliation(s)
- T Tsuzuki
- Department of Medical Biophysics and Radiation Biology, Faculty of Medical Sciences, Graduate Schools, Kyushu University, 812-8582, Fukuoka, Japan.
| | | | | |
Collapse
|
37
|
Zhu WG, Antoku S, Kura S, Aramaki R, Nakamura K, Sasaki H. Enhancement of hyperthermic killing in L5178Y cells by protease inhibitors. Cancer Res 1995; 55:739-42. [PMID: 7850783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We have investigated the effect of protease inhibitors on hyperthermic cell killing using cultured mammalian cells (L5178Y) and found that protease inhibitors were potent hyperthermia sensitizers. At 37 degrees C, phenylmethylsulfonyl fluoride (PMSF), a serine protease inhibitor, was not cytotoxic at the concentration of 400 micrograms/ml for up to 6 h. When cells were exposed to PMSF (200-400 micrograms/ml) during heating at 43 degrees C, significant potentiation of hyperthermic cell killing was observed. Other protease inhibitors, such as chymostatin and diisopropylfluorophosphate (both are serine protease inhibitors); (2S,3S)-trans-epoxy-succinyl-L-leucylamido-3-methylbutane ethyl ester (cysteine protease inhibitor) and pepstatin-A (aspartate protease inhibitor) showed similar effects. However, when cells were heated at 43 degrees C in the presence of cycloheximide (a protein synthesis inhibitor) together with PMSF, hyperthermic enhancement by PMSF decreased markedly. A decrease in potentiating the effect of PMSF was also noted with thermotolerant cells. These facts suggest that protease inhibitors may exert their hyperthermic cell killing by inhibiting proteases and ubiquitin, which are necessary to degrade denatured proteins induced by heat.
Collapse
Affiliation(s)
- W G Zhu
- Department of Experimental Radiology, Faculty of Medicine, Kyushu University, Fukuoka, Japan
| | | | | | | | | | | |
Collapse
|
38
|
Antoku S, Kura S. Enhancement of radiosensitivity of cultured mammalian cells by neocarzinostatin. II. Fixation of potentially lethal damage. Int J Radiat Biol 1990; 58:623-32. [PMID: 1976723 DOI: 10.1080/09553009014551981] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The effects of neocarzinostatin (NCS), an anti-tumour drug, on the repair of potentially lethal damage (PLD) were studied using cultured Chinese hamster V79, malignant human melanoma and mouse lymphoma L5178Y cells in the stationary phase. The repair of PLD was observed in the melanoma and L5178Y cells but no such repair was observed in the V79 cells, when studied by delayed plating. NCS added to the culture medium immediately after X-irradiation evoked fixation of PLD within 10 min of the addition of NCS. The ratios of D0 values of the survival curves of the cells treated with NCS to those plated immediately after X-irradiation were 0.78, 0.88 and 0.85 for V79, melanoma and L5178Y cells, respectively. The extent of the fixation by NCS was similar to that caused by 0.5 M NaCl solution. The results in the present study and the inhibition of sublethal damage (SLD) by NCS reported previously, suggest that NCS might react with the DNA damage induced by radiation and modify it to lethal damage. The study indicates that SLD and PLD appear to be closely related to one another.
Collapse
Affiliation(s)
- S Antoku
- Department of Experimental Radiology, Faculty of Medicine, Kyushu University, Fukuoka, Japan
| | | |
Collapse
|
39
|
Antoku S, Kura S. Enhancement of radiosensitivity of cultured mammalian cells by neocarzinostatin. I. Inhibition of the repair of sublethal damage. Int J Radiat Biol 1990; 58:613-22. [PMID: 1976722 DOI: 10.1080/09553009014551971] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The enhancement of radiosensitivity by neocarzinostatin (NCS), an antitumour drug, was studied using three strains of cultured mammalian cells with different repair capabilities for sublethal damage. NCS enhanced the radiosensitivity of the cells when applied both during and after X-irradiation under aerobic conditions. The enhancement ratios of NCS during X-irradiation were 1.25, 1.27 and 1.38 for mouse lymphoma L5178Y, Chinese hamster V79 and mouse mammary tumour FM 3A cells, respectively. The corresponding ratios after X-irradiation were 1.18, 1.27 and 1.38, respectively. These ratios were proportional to the repair capabilities of the cells for sublethal damage. NCS completely inhibited the repair of sublethal damage regardless of the repair capabilities of the cells for sublethal damage. NCS was equally effective for hypoxic cells. These results suggested that NCS enhanced the radiosensitivity of the cells probably by interacting with the residual damage after X-irradiation, thereby converting the sublethal damage or potentially lethal damage into lethal damage.
Collapse
Affiliation(s)
- S Antoku
- Department of Experimental Radiology, Faculty of Medicine, Kyushu University, Fukuoka, Japan
| | | |
Collapse
|
40
|
Sasaki H, Yoshinaga H, Kura S. Binucleate Cell Formation Correlates to Loss of Colony-Forming Ability in X-Irradiated Cultured Mammalian Cells. Radiat Res 1986. [DOI: 10.2307/3576922] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
41
|
Sasaki H, Yoshinaga H, Kura S. Binucleate cell formation correlates to loss of colony-forming ability in X-irradiated cultured mammalian cells. Radiat Res 1986; 108:348-53. [PMID: 3797640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The relationship between binucleate cell formation and the loss of colony-forming ability was examined in several cultured mammalian cell lines irradiated with X rays. The maximum fraction of binucleate cells after X irradiation increased dose-dependently within the range in which reproductive cell death might predominate over interphase cell death. When the logarithm of percentage survival was plotted against the percentage binucleate cells, a similar correlation was found for all cell lines tested, with the exception of mouse leukemia L5178Y cells, the most radiosensitive cells used. These observations suggest that the fraction of binucleate cells in the cell population can serve as a measure of cellular radiation damage.
Collapse
|
42
|
Kura S. [Binucleate cell formation after fast neutron and alpha-particle irradiation (author's transl)]. Fukuoka Igaku Zasshi 1980; 71:593-99. [PMID: 7239415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
|
43
|
Kura S, Yoshida J, Yoshinaga H. [The basic test of two types of tritium survey meter (author's transl)]. Radioisotopes 1979; 28:642-4. [PMID: 531245 DOI: 10.3769/radioisotopes.28.10_642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
44
|
|
45
|
Kura S, Sasaki H, Aramaki R, Yoshinaga H. Binucleate cell formation induced by X irradiation. Radiat Res 1978; 76:83-94. [PMID: 734051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|