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Katz BM, Walton LR, Houston KM, Cerri DH, Shih YYI. Putative neurochemical and cell type contributions to hemodynamic activity in the rodent caudate putamen. J Cereb Blood Flow Metab 2023; 43:481-498. [PMID: 36448509 PMCID: PMC10063835 DOI: 10.1177/0271678x221142533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 09/28/2022] [Accepted: 10/21/2022] [Indexed: 12/02/2022]
Abstract
Functional magnetic resonance imaging (fMRI) is widely used by researchers to noninvasively monitor brain-wide activity. The traditional assumption of a uniform relationship between neuronal and hemodynamic activity throughout the brain has been increasingly challenged. This relationship is now believed to be impacted by heterogeneously distributed cell types and neurochemical signaling. To date, most cell-type- and neurotransmitter-specific influences on hemodynamics have been examined within the cortex and hippocampus of rodent models, where glutamatergic signaling is prominent. However, neurochemical influences on hemodynamics are relatively unknown in largely GABAergic brain regions such as the rodent caudate putamen (CPu). Given the extensive contribution of CPu function and dysfunction to behavior, and the increasing focus on this region in fMRI studies, improved understanding of CPu hemodynamics could have broad impacts. Here we discuss existing findings on neurochemical contributions to hemodynamics as they may relate to the CPu with special consideration for how these contributions could originate from various cell types and circuits. We hope this review can help inform the direction of future studies as well as interpretation of fMRI findings in the CPu.
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Affiliation(s)
- Brittany M Katz
- Neuroscience Curriculum, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Center for Animal MRI, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Lindsay R Walton
- Center for Animal MRI, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Kaiulani M Houston
- Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, USA
| | - Domenic H Cerri
- Center for Animal MRI, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Yen-Yu Ian Shih
- Neuroscience Curriculum, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Center for Animal MRI, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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13-cis-Retinoic Acid Affects Brain Perfusion and Function: In Vivo Study. Mol Imaging 2023. [DOI: 10.1155/2023/7855924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023] Open
Abstract
Purpose. Study the effects of 13-cis-retinoic acid (13-RA), a synthetic analogue of a vitamin A used for the treatment of severe acne, on the blood flow in the rat brain using technetium-99m hexamethyl propylene amine oxime (99mTc-HMPAO) imaging. Methods. A total of 30 adult male Wistar rats were divided into the control (C), low-dose (L), and high-dose (H) groups. The L and H rats were exposed subcutaneously to 0.3 and 0.5 mg, respectively, of 13-RA per kg of body weight for seven days. Brain blood flow imaging was performed using a gamma camera. Then, a region of interest (ROI) around the brain (target, T), a whole-body region (WB), and a background region (BG) was selected and delimited. The net 99mTc-HMPAO brain counts were calculated as the net target counts,
in all groups. At the end of the 99mTc-HMPAO brain blood flow imaging, the brain, heart, kidney, lung, and liver were rapidly removed, and their uptake was determined. Brain histopathological analysis was performed using hematoxylin and eosin stains. In addition, the plasma fatty acids were studied using gas chromatography/mass spectrometry. Results. There were highly significant differences between L and H in comparison to C and across the groups. The 99mTc-HMPAO radioactivity in the brain showed increased uptake in a dose-dependent manner. There were also significant changes in the brain tissues and decreased free fatty acids among the groups compared to C. Conclusion. 13-RA increases 99mTcHMPAO brain perfusion, uptake, and function and reduces fatty acids.
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Stem Cells as Drug-like Biologics for Mitochondrial Repair in Stroke. Pharmaceutics 2020; 12:pharmaceutics12070615. [PMID: 32630218 PMCID: PMC7407993 DOI: 10.3390/pharmaceutics12070615] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 06/25/2020] [Accepted: 06/26/2020] [Indexed: 01/01/2023] Open
Abstract
Stroke is a devastating condition characterized by widespread cell death after disruption of blood flow to the brain. The poor regenerative capacity of neural cells limits substantial recovery and prolongs disruptive sequelae. Current therapeutic options are limited and do not adequately address the underlying mitochondrial dysfunction caused by the stroke. These same mitochondrial impairments that result from acute cerebral ischemia are also present in retinal ischemia. In both cases, sufficient mitochondrial activity is necessary for cell survival, and while astrocytes are able to transfer mitochondria to damaged tissues to rescue them, they do not have the capacity to completely repair damaged tissues. Therefore, it is essential to investigate this mitochondrial transfer pathway as a target of future therapeutic strategies. In this review, we examine the current literature pertinent to mitochondrial repair in stroke, with an emphasis on stem cells as a source of healthy mitochondria. Stem cells are a compelling cell type to study in this context, as their ability to mitigate stroke-induced damage through non-mitochondrial mechanisms is well established. Thus, we will focus on the latest preclinical research relevant to mitochondria-based mechanisms in the treatment of cerebral and retinal ischemia and consider which stem cells are ideally suited for this purpose.
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Kingsbury C, Heyck M, Bonsack B, Lee JY, Borlongan CV. Stroke gets in your eyes: stroke-induced retinal ischemia and the potential of stem cell therapy. Neural Regen Res 2019; 15:1014-1018. [PMID: 31823871 PMCID: PMC7034271 DOI: 10.4103/1673-5374.270293] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Stroke persists as a global health and economic crisis, yet only two interventions to reduce stroke-induced brain injury exist. In the clinic, many patients who experience an ischemic stroke often further suffer from retinal ischemia, which can inhibit their ability to make a functional recovery and may diminish their overall quality of life. Despite this, no treatments for retinal ischemia have been developed. In both cases, ischemia-induced mitochondrial dysfunction initiates a cell loss cascade and inhibits endogenous brain repair. Stem cells have the ability to transfer healthy and functional mitochondria not only ischemic neurons, but also to similarly endangered retinal cells, replacing their defective mitochondria and thereby reducing cell death. In this review, we encapsulate and assess the relationship between cerebral and retinal ischemia, recent preclinical advancements made using in vitro and in vivo retinal ischemia models, the role of mitochondrial dysfunction in retinal ischemia pathology, and the therapeutic potential of stem cell-mediated mitochondrial transfer. Furthermore, we discuss the pitfalls in classic rodent functional assessments and the potential advantages of laser Doppler as a metric of stroke progression. The studies evaluated in this review highlight stem cell-derived mitochondrial transfer as a novel therapeutic approach to both retinal ischemia and stroke. Furthermore, we posit the immense correlation between cerebral and retinal ischemia as an underserved area of study, warranting exploration with the aim of these treating injuries together.
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Affiliation(s)
- Chase Kingsbury
- Center of Excellence for Aging and Brain Repair, University of South Florida College of Medicine, Tampa, FL, USA
| | - Matt Heyck
- Center of Excellence for Aging and Brain Repair, University of South Florida College of Medicine, Tampa, FL, USA
| | - Brooke Bonsack
- Center of Excellence for Aging and Brain Repair, University of South Florida College of Medicine, Tampa, FL, USA
| | - Jea-Young Lee
- Center of Excellence for Aging and Brain Repair, University of South Florida College of Medicine, Tampa, FL, USA
| | - Cesar V Borlongan
- Center of Excellence for Aging and Brain Repair, University of South Florida College of Medicine, Tampa, FL, USA
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5
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Immunological considerations and concerns as pertinent to whole eye transplantation. Curr Opin Organ Transplant 2019; 24:726-732. [PMID: 31689262 DOI: 10.1097/mot.0000000000000713] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
PURPOSE OF REVIEW The advent of clinical vascularized composite allotransplantation (VCA), offers hope for whole eye transplantation (WET) in patients with devastating vison loss that fails or defies current treatment options. Optic nerve regeneration and reintegration remain the overarching hurdles to WET. However, the realization of WET may indeed be limited by our lack of understanding of the singular immunological features of the eye as pertinent to graft survival and functional vision restoration in the setting of transplantation. RECENT FINDINGS Like other VCA, such as the hand or face, the eye includes multiple tissues with distinct embryonic lineage and differential antigenicity. The ultimate goal of vision restoration through WET requires optimal immune modulation of the graft for successful optic nerve regeneration. Our team is exploring barriers to our understanding of the immunology of the eye in the context of WET including the role of immune privilege and lymphatic drainage on rejection, as well as the effects ischemia, reperfusion injury and rejection on optic nerve regeneration. SUMMARY Elucidation of the unique immunological responses in the eye and adnexa after WET will provide foundational clues that will help inform therapies that prevent immune rejection without hindering optic nerve regeneration or reintegration.
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Heyck M, Bonsack B, Zhang H, Sadanandan N, Cozene B, Kingsbury C, Lee JY, Borlongan CV. The brain and eye: Treating cerebral and retinal ischemia through mitochondrial transfer. Exp Biol Med (Maywood) 2019; 244:1485-1492. [PMID: 31604382 DOI: 10.1177/1535370219881623] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Stroke remains a devastating disease with limited treatment options, despite our growing understanding of its pathology. While ischemic stroke is traditionally characterized by a blockage of blood flow to the brain, this may coincide with reduced blood circulation to the eye, resulting in retinal ischemia, which may in turn lead to visual impairment. Although effective treatment options for retinal ischemia are similarly scarce, new evidence suggests that deleterious changes to mitochondrial structure and function play a major role in both cerebral and retinal ischemia pathologies. Prior studies establish that astrocytes transfer healthy mitochondria to ischemic neurons following stroke; however, this alone is not enough to significantly mitigate the damage caused by primary and secondary cell death. Thus, stem cell-based regenerative medicine targeting amelioration of ischemia-induced mitochondrial dysfunction via the transfer of functional mitochondria to injured neural cells represents a promising approach to improve stroke outcomes for both cerebral and retinal ischemia. In this review, we evaluate recent laboratory evidence supporting the remedial capabilities of mitochondrial transfer as an innovative stroke treatment. In particular, we examine exogenous stem cell transplants in their potential role as suppliers of healthy mitochondria to neurons, brain endothelial cells, and retinal cells.Impact statementStroke constitutes a global health crisis, yet potent, applicable therapeutic options remain effectively inaccessible for many patients. To this end, stem cell transplants stand as a promising stroke treatment and as an emerging subject of research for cell-based regenerative medicine. This is the first review to synthesize the implications of stem cell-derived mitochondrial transfer in both the brain and the eye. As such, this report carries fresh insight into the commonalities between the two stroke-affected organs. We present the findings of this developing area of research inquiry with the hope that our evaluation may advance the use of stem cell transplants as viable therapeutic alternatives for ischemic stroke and related disorders characterized by mitochondrial dysfunction. Such lab-to-clinic translational advancement has the potential to save and improve the ever increasing millions of lives affected by stroke.
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Affiliation(s)
- Matt Heyck
- Center of Excellence for Aging and Brain Repair University of South Florida College of Medicine, Tampa, FL 33612, USA
| | - Brooke Bonsack
- Center of Excellence for Aging and Brain Repair University of South Florida College of Medicine, Tampa, FL 33612, USA
| | - Henry Zhang
- Center of Excellence for Aging and Brain Repair University of South Florida College of Medicine, Tampa, FL 33612, USA
| | - Nadia Sadanandan
- Center of Excellence for Aging and Brain Repair University of South Florida College of Medicine, Tampa, FL 33612, USA
| | - Blaise Cozene
- Center of Excellence for Aging and Brain Repair University of South Florida College of Medicine, Tampa, FL 33612, USA
| | - Chase Kingsbury
- Center of Excellence for Aging and Brain Repair University of South Florida College of Medicine, Tampa, FL 33612, USA
| | - Jea-Young Lee
- Center of Excellence for Aging and Brain Repair University of South Florida College of Medicine, Tampa, FL 33612, USA
| | - Cesar V Borlongan
- Center of Excellence for Aging and Brain Repair University of South Florida College of Medicine, Tampa, FL 33612, USA
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Lecler A, Bailleux J, Carsin B, Adle-Biassette H, Baloglu S, Bogey C, Bonneville F, Calvier E, Comby PO, Cottier JP, Cotton F, Deschamps R, Diard-Detoeuf C, Ducray F, Duron L, Drissi C, Elmaleh M, Farras J, Garcia JA, Gerardin E, Grand S, Jianu DC, Kremer S, Magne N, Mejdoubi M, Moulignier A, Ollivier M, Nagi S, Rodallec M, Sadik JC, Shor N, Tourdias T, Vandendries C, Broquet V, Savatovsky J. Multinodular and Vacuolating Posterior Fossa Lesions of Unknown Significance. AJNR Am J Neuroradiol 2019; 40:1689-1694. [PMID: 31558497 DOI: 10.3174/ajnr.a6223] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 07/27/2019] [Indexed: 12/15/2022]
Abstract
Multinodular and vacuolating neuronal tumor of the cerebrum is a rare supratentorial brain tumor described for the first time in 2013. Here, we report 11 cases of infratentorial lesions showing similar striking imaging features consisting of a cluster of low T1-weighted imaging and high T2-FLAIR signal intensity nodules, which we referred to as multinodular and vacuolating posterior fossa lesions of unknown significance. No relationship was found between the location of the lesion and clinical symptoms. A T2-FLAIR hypointense central dot sign was present in images of 9/11 (82%) patients. Cortical involvement was present in 2/11 (18%) of patients. Only 1 nodule of 1 multinodular and vacuolating posterior fossa lesion of unknown significance showed enhancement on postcontrast T1WI. DWI, SWI, MRS, and PWI showed no malignant pattern. Lesions did not change in size or signal during a median follow-up of 3 years, suggesting that multinodular and vacuolating posterior fossa lesions of unknown significance are benign malformative lesions that do not require surgical intervention or removal.
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Affiliation(s)
- A Lecler
- From the Departments of Neuroradiology (A.L., J.B., L.D., J.-C.S., C.V., V.B., J.S.)
| | - J Bailleux
- From the Departments of Neuroradiology (A.L., J.B., L.D., J.-C.S., C.V., V.B., J.S.)
| | - B Carsin
- Department of Radiology (B.C., J.S.), Centre Hospitalier Régional Universitaire de Rennes, Rennes, France
| | - H Adle-Biassette
- Department of Pathology (H.A.-B.), Lariboisière Hospital, Paris Diderot, Paris-Cité-Sorbonne University, Paris, France
| | - S Baloglu
- Department of Radiology (S.B., S.K.), University Hospital of Strasbourg, Strasbourg, France
| | - C Bogey
- Department of Neuroradiology (C.B.), Centre Hospitalier Universitaire Limoges, Limoges, France
| | - F Bonneville
- Department of Neuroradiology (F.B.), Hôpital Pierre-Paul-Riquet, Centre Hospitalier Universitaire Purpan, Toulouse, France
| | - E Calvier
- Neurology Department (E.C., J.A.G.), Hôpital René et Guillaume-Laënnec, Centre Hospitalier Universitaire de Nantes, Saint-Herblain, France
| | - P-O Comby
- Department of Vascular and Interventional Radiology (P.-O.C.), Image-Guided Therapy Center, François-Mitterrand University Hospital, Dijon Cedex, France
| | - J-P Cottier
- Department of Radiology (J.-P.C.), Centre Hospitalier Régional Universitaire de Tours, Tours, France.,Brain and Imaging Laboratory (J.-P.C.), UMR U930, National Institute for Health and Medical Research, François-Rabelais University, Tours, France
| | - F Cotton
- Service de Radiologie (F.C.), Centre Hospitalier Lyon-Sud, Hospices Civils de Lyon, University Claude Bernard Lyon 1, Lyon, France.,Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS) (F.C.), National Institute for Health and Medical Research U1044/Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR) 5220, Lyon, France
| | - R Deschamps
- Neurology (R.D., A.M.), Fondation Ophtalmologique A. Rothschild, Paris, France
| | - C Diard-Detoeuf
- Department of Neurology (C.D.-D.), CH Sainte-Périne, Paris, France
| | - F Ducray
- Department of Neuro-Oncology (F.D.), Lyon French Reference Center of Paraneoplastic Neurological Syndrome, Hospices Civils de Lyon, Hôpital Neurologique, Bron Cedex, France.,Synatac Team (F.D.), NeuroMyoGene Institut, National Institute for Health and Medical Research U1217/Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR) 5310, Lyon, France.,University Claude Bernard Lyon 1 (F.D.), Lyon, France
| | - L Duron
- From the Departments of Neuroradiology (A.L., J.B., L.D., J.-C.S., C.V., V.B., J.S.)
| | - C Drissi
- Institut National de Neurologie (C.D., S.N.), Service de Neuroradiologie, Université de Tunis El Manar, Faculté de Médecine de Tunis, Tunis, Tunisia
| | - M Elmaleh
- Pediatric Radiology Department (M.E.), Robert Debré Hospital, Paris, France
| | - J Farras
- Jordi Radiologia C/de la Roda (J.F.), Andorra la Vella, Andorra
| | - J A Garcia
- Neurology Department (E.C., J.A.G.), Hôpital René et Guillaume-Laënnec, Centre Hospitalier Universitaire de Nantes, Saint-Herblain, France
| | - E Gerardin
- Department of Neuroradiology and MRI (E.G., N.M.), Rouen University Hospital, Rouen, France
| | - S Grand
- Neuroradiologie Diagnostique et Interventionnelle et IRM Nord (S.G.), Centre Hospitalier et Universitaire de Alpes Grenoble, Grenoble, France
| | - D C Jianu
- Department of Neurology (D.C.J.), Victor Babes University of Medicine and Pharmacy, Timisoara, Romania
| | - S Kremer
- Department of Radiology (S.B., S.K.), University Hospital of Strasbourg, Strasbourg, France
| | - N Magne
- Department of Neuroradiology and MRI (E.G., N.M.), Rouen University Hospital, Rouen, France
| | - M Mejdoubi
- Department of Neuroradiology (M.M.), University Hospital of Martinique, Fort-de-France, Martinique, France
| | - A Moulignier
- Neurology (R.D., A.M.), Fondation Ophtalmologique A. Rothschild, Paris, France
| | - M Ollivier
- Groupe Hospitalier Pellegrin (M.O.), Bordeaux, France
| | - S Nagi
- Institut National de Neurologie (C.D., S.N.), Service de Neuroradiologie, Université de Tunis El Manar, Faculté de Médecine de Tunis, Tunis, Tunisia.,Clinique les Berges du Lac (S.N.), les Berges du Lac, Tunis, Tunisia
| | - M Rodallec
- Centre d'Imagerie Centre Cardiologique du Nord (M.R.), CCN, Saint-Denis, France
| | - J-C Sadik
- From the Departments of Neuroradiology (A.L., J.B., L.D., J.-C.S., C.V., V.B., J.S.)
| | - N Shor
- Department of Neuroradiology (N.S.), Pitié-Salpêtrière Hospital, Paris, France
| | - T Tourdias
- Service de Neuroimagerie Diagnostique et Thérapeutique (T.T.), Centre Hospitalier Universitaire de Bordeaux et National Institute for Health and Medical Research U1215, Université de Bordeaux, Bordeaux, France
| | - C Vandendries
- From the Departments of Neuroradiology (A.L., J.B., L.D., J.-C.S., C.V., V.B., J.S.).,Centre d'Imagerie Médicale Paris 15ème (C.V.), RMX, Paris, France
| | - V Broquet
- Department of Neuroradiology (V.B.), Centre Hospitalier Universitaire Lille, Lille, France
| | - J Savatovsky
- From the Departments of Neuroradiology (A.L., J.B., L.D., J.-C.S., C.V., V.B., J.S.).,Department of Radiology (B.C., J.S.), Centre Hospitalier Régional Universitaire de Rennes, Rennes, France.,Imagerie Paris 13 (J.S.), Paris, France
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Demonstration of technical feasibility and viability of whole eye transplantation in a rodent model. J Plast Reconstr Aesthet Surg 2019; 72:1640-1650. [PMID: 31377202 DOI: 10.1016/j.bjps.2019.05.042] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 04/17/2019] [Accepted: 05/02/2019] [Indexed: 11/22/2022]
Abstract
INTRODUCTION Whole eye transplantation (WET) holds promise for vision restoration in devastating/disabling visual loss (congenital or traumatic) not amenable to surgical or neuroprosthetic treatment options. The eye includes multiple tissues with distinct embryonic lineage and differential antigenicity. Anatomically and immunologically, the eye is unique due to its avascular (cornea) and highly vascular (retina) components. Our goal was to establish technical feasibility, demonstrate graft viability, and evaluate histologic changes in ocular tissues/adnexae in a novel experimental model of WET that included globe, adnexal, optic nerve (ON), and periorbital soft tissues. METHODS Outbred Sprague-Dawley rats (n = 5) received heterotopic vascularized WET from donors. Each WET included the entire globe, adnexa, ON, and periorbital soft tissues supplied by the common carotid artery and external jugular vein. Viability and perfusion were confirmed by clinical examination, angiography and magnetic resonance imaging (MRI). Globe, adnexal, and periorbital tissues were analyzed for histopathologic changes, and the ON was examined for neuro-regeneration at study endpoint (30 days) or Banff Grade 3 rejection in the periorbital skin (whichever was earlier). RESULTS Gross examination confirmed transplant viability and corneal transparency. Average operative duration was 64.0 ± 5.8 min. Average ischemia time was 26.0 ± 4.2 min. MRI revealed loss of globe volume by 36.0 ± 2.8% after transplantation. Histopathology of globe and adnexal tissues showed unique and differential patterns of inflammatory cell infiltration. The ON revealed a neurodegeneration pattern. CONCLUSION The present study is the first in the literature to establish an experimental model of WET. This model holds significant potential in investigating mechanistic pathways, monitoring strategies or developing management approaches involving ocular viability, immune rejection, and ON regeneration after WET.
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9
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Abstract
Supplemental Digital Content is available in the text. Retinal ischemia is a major cause of visual impairment in stroke patients, but our incomplete understanding of its pathology may contribute to a lack of effective treatment. Here, we investigated the role of mitochondrial dysfunction in retinal ischemia and probed the potential of mesenchymal stem cells (MSCs) in mitochondrial repair under such pathological condition.
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Affiliation(s)
- Hung Nguyen
- From the Center of Excellence for Aging and Brain Repair, University of South Florida Morsani College of Medicine, Tampa (H.N., J.Y.L., P.R.S., C.V.B.)
| | - Jea Young Lee
- From the Center of Excellence for Aging and Brain Repair, University of South Florida Morsani College of Medicine, Tampa (H.N., J.Y.L., P.R.S., C.V.B.)
| | - Paul R Sanberg
- From the Center of Excellence for Aging and Brain Repair, University of South Florida Morsani College of Medicine, Tampa (H.N., J.Y.L., P.R.S., C.V.B.)
| | - Eleonora Napoli
- Department of Molecular Biosciences, University of California Davis (E.N.)
| | - Cesar V Borlongan
- From the Center of Excellence for Aging and Brain Repair, University of South Florida Morsani College of Medicine, Tampa (H.N., J.Y.L., P.R.S., C.V.B.)
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10
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Urtti A. Retinal bioavailability of liposomal minocycline after sub-conjunctival administration is low. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2019; 18:427. [PMID: 30664945 DOI: 10.1016/j.nano.2018.12.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 12/19/2018] [Indexed: 10/27/2022]
Affiliation(s)
- Arto Urtti
- Laboratory of Biohybrid Technologies (Russian Mega-Grant 14.W03.031.0025), Institute of Chemistry, Saint-Petersburg State University, Russian Federation; Faculty of Pharmacy, University of Helsinki, Finland; School of Pharmacy, University of Eastern Finland, Kuopio, Finland.
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Koustenis A, Harris A, Gross J, Januleviciene I, Shah A, Siesky B. Optical coherence tomography angiography: an overview of the technology and an assessment of applications for clinical research. Br J Ophthalmol 2016; 101:16-20. [PMID: 27707691 DOI: 10.1136/bjophthalmol-2016-309389] [Citation(s) in RCA: 110] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 09/07/2016] [Accepted: 09/17/2016] [Indexed: 12/27/2022]
Abstract
In recent years, ophthalmology has experienced significant developments with respect to imaging modalities. Optical coherence tomography angiography is one such technology that seeks to improve diagnostics for retinal diseases. Using standard structural ocular coherence tomography hardware, optical coherence tomography angiography demonstrates the ability to non-invasively visualise the vasculature in the retina and the choroid with high resolution, allowing greater insight into retinal vascular pathologies. In addition, retinal and choroidal vessel density and blood flow can be quantified, offering potential to assist in the diagnosis of a variety of retinal diseases. To date, numerous retinal diseases, such as open-angle glaucoma, have been found to possess a vascular component. Specifically, ischaemia of the optic nerve head and lamina cribrosa has been theorised as a causative factor in ganglion cell death; however, confirmation of this mechanism has been prohibited by the limitations of currently existing imaging modalities. Optical coherence tomography angiography provides clear imaging of these regions and the possibility to elucidate further understanding of vascular factors that contribute to glaucoma development and progression. Furthermore, this imaging modality may provide insight to neural pathologies with vascular components such as Alzheimer's disease. Herein, the authors discuss the theory of operation for optical coherence tomography angiography and the current findings from pilot studies with a focus on open-angle glaucoma. In addition, speculation is offered for future applications of the technology to study other diseases with microvascular contributions.
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Affiliation(s)
- Andrew Koustenis
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Alon Harris
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Josh Gross
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | | | - Aaditya Shah
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Brent Siesky
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, Indiana, USA
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12
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Abstract
Blood flow is a useful indicator of the metabolic state of the retina. However, accurate measurement of retinal blood flow is difficult to achieve in practice. Most existing optical techniques used for measuring blood flow require complex assumptions and calculations. We describe here a simple and direct method for calculating absolute blood flow in vessels of all sizes in the rat retina. The method relies on ultrafast confocal line scans to track the passage of fluorescently labeled red blood cells (fRBCs). The accuracy of the blood flow measurements was verified by (1) comparing blood flow calculated independently using either flux or velocity combined with diameter measurements, (2) measuring total retinal blood flow in arterioles and venules, (3) measuring blood flow at vessel branch points, and (4) measuring changes in blood flow in response to hyperoxic and hypercapnic challenge. Confocal line scans oriented parallel and diagonal to vessels were used to compute fRBC velocity and to examine velocity profiles across the width of vessels. We demonstrate that these methods provide accurate measures of absolute blood flow and velocity in retinal vessels of all sizes.
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Dynamic perfusion and diffusion MRI of cortical spreading depolarization in photothrombotic ischemia. Neurobiol Dis 2014; 71:131-9. [PMID: 25066776 DOI: 10.1016/j.nbd.2014.07.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Revised: 06/15/2014] [Accepted: 07/16/2014] [Indexed: 11/21/2022] Open
Abstract
Cortical spreading depolarization (CSD) is known to exacerbate ischemic damage, as the number of CSDs correlates with the final infarct volumes and suppressing CSDs improves functional outcomes. To investigate the role of CSD in ischemic damage, we developed a novel rat model of photothrombotic ischemia using a miniature implantable optic fiber that allows lesion induction inside the magnetic resonance imaging (MRI) scanner. We were able to precisely control the location and the size of the ischemic lesion, and continuously monitor dynamic perfusion and diffusion MRI signal changes at high temporal resolution before, during and after the onset of focal ischemia. Our model showed that apparent diffusion coefficient (ADC) and cerebral blood flow (CBF) in the ischemic core dropped immediately after lesion onset by 20±6 and 41±23%, respectively, and continually declined over the next 5h. Meanwhile, CSDs were observed in all animals (n=36) and displayed either a transient decrease of ADC by 17±3% or an increase of CBF by 104±15%. All CSDs were initiated from the rim of the ischemic core, propagated outward, and confined to the ipsilesional cortex. Additionally, we demonstrated that by controlling the size of perfusion-diffusion mismatch (which approximates the penumbra) in our model, the number of CSDs correlated with the mismatch area rather than the final infarct volume. This study introduces a novel platform to study CSDs in real-time with high reproducibility using MRI.
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