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Nakagawa S, Aruga J. Sphingosine 1-Phosphate Signaling Is Involved in Impaired Blood-Brain Barrier Function in Ischemia-Reperfusion Injury. Mol Neurobiol 2019; 57:1594-1606. [PMID: 31802363 DOI: 10.1007/s12035-019-01844-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 11/22/2019] [Indexed: 12/20/2022]
Abstract
Sphingosine 1-phosphate (S1P) is a major bioactive lipid mediator in the vascular and immune system. Here, we have shown that inhibition of S1P signaling prevents blood-brain barrier (BBB) dysfunction after ischemia both in vitro and in vivo. In the in vitro BBB models, oxygen-glucose deprivation and reoxygenation (OGD/R) enhanced the expression of an S1P synthesizing enzyme (Sphk1) and S1P transporters (Abca1, Spns2), increasing S1P in culture media. Inhibitors of Sphk1 (SKI-II) or Abca1 (probucol) attenuated the decrease in transendothelial electrical resistance and the increase in permeability caused by OGD/R. In the middle cerebral artery occlusion and reperfusion (MCAO/R) model of mice, probucol administration after MCAO operation reduced the infarction area and vascular leakage, preserving the integrity of tight junction proteins. Furthermore, MCAO/R caused activation of STAT3, a downstream mediator of S1P signaling, which was suppressed by postoperative probucol administration. Accordingly, S1P activated STAT3, both in cultured vascular endothelial cells and pericytes, and STAT3 signaling inhibitor (Stattic) protected BBB dysfunction in OGD/R-treated in vitro BBB models. These results suggest that inhibition of S1P signaling is a strategy to treat BBB impairment after cerebral ischemia and highlight the potential alternative use of probucol, a classical anti-hyperlipidemic drug, for emergency treatment of stroke.
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Affiliation(s)
- Shinsuke Nakagawa
- Department of Medical Pharmacology, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan.
| | - Jun Aruga
- Department of Medical Pharmacology, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan
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2
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Berntsen NL, Fosby B, Valestrand L, Tan C, Reims HM, Schrumpf E, Karlsen TH, Line PD, Melum E. Establishment of a surgical bile duct injection technique giving direct access to the bile ducts for studies of the murine biliary tree. Am J Physiol Gastrointest Liver Physiol 2018; 314:G349-G359. [PMID: 29212771 DOI: 10.1152/ajpgi.00124.2017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Cholangiopathies are progressive disorders with largely unknown pathoetiology and limited treatment options. We aimed to develop a novel surgical technique with direct access to the bile ducts that would complement existing mouse models of cholestasis, biliary inflammation, and fibrosis and present a new route of administration for testing of potential treatment strategies. We developed a surgical technique to access the murine biliary tree by injection of different solvents through catheterization of the gall bladder with simultaneous clamping of the common bile duct. To demonstrate the applicability of the technique, we injected either phosphate-buffered saline or dimethyl sulfoxide in concentrations of 50 or 65% and compared these groups with sham-operated mice. The surgery was optimized to achieve a mortality rate close to 0. There were no significant changes in pain, activity level, or mortality from the day of the surgery until euthanization for any groups. Injection of phosphate-buffered saline or 50% dimethyl sulfoxide was generally well-tolerated, whereas 65% dimethyl sulfoxide led to higher weight loss, an increase of serum alanine transaminase, and histological portal inflammation. There were no signs of inflammation in the gut. We have developed a bile duct injection technique that is well-tolerated, easily reproducible, and that may complement existing models of cholangiopathies. Direct access to the bile ducts without causing harm to the hepatobiliary or intestinal tissue may be valuable in future studies of normal biliary physiology and different pathophysiological mechanisms of disease and to test novel therapeutic strategies. NEW & NOTEWORTHY To evaluate tolerability of the bile duct to injection of both polar and nonpolar compounds, we established a novel biliary injection technique. This technique is well-tolerated, easily reproducible, and with direct access to the bile ducts for studies of the murine biliary tree. The bile duct injection technique may complement existing animal models and be a valuable tool in future studies of normal biliary physiology or pathophysiology and to test novel therapeutic strategies.
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Affiliation(s)
- Natalie Lie Berntsen
- Norwegian Primary Sclerosing Cholangitis Research Center, Department of Transplantation Medicine, Division of Surgery, Inflammatory Diseases and Transplantation, Oslo University Hospital Rikshospitalet , Oslo , Norway.,Research Institute of Internal Medicine, Division of Surgery, Inflammatory Diseases and Transplantation, Oslo University Hospital , Oslo , Norway.,K.G. Jebsen Inflammation Research Centre, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo , Oslo , Norway
| | - Bjarte Fosby
- Norwegian Primary Sclerosing Cholangitis Research Center, Department of Transplantation Medicine, Division of Surgery, Inflammatory Diseases and Transplantation, Oslo University Hospital Rikshospitalet , Oslo , Norway.,Department of Transplantation Medicine, Division of Surgery, Inflammatory Diseases and Transplantation, Oslo University Hospital Rikshospitalet , Oslo , Norway
| | - Laura Valestrand
- Norwegian Primary Sclerosing Cholangitis Research Center, Department of Transplantation Medicine, Division of Surgery, Inflammatory Diseases and Transplantation, Oslo University Hospital Rikshospitalet , Oslo , Norway.,Research Institute of Internal Medicine, Division of Surgery, Inflammatory Diseases and Transplantation, Oslo University Hospital , Oslo , Norway.,K.G. Jebsen Inflammation Research Centre, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo , Oslo , Norway
| | - Corey Tan
- Norwegian Primary Sclerosing Cholangitis Research Center, Department of Transplantation Medicine, Division of Surgery, Inflammatory Diseases and Transplantation, Oslo University Hospital Rikshospitalet , Oslo , Norway
| | - Henrik M Reims
- Department of Pathology, Oslo University Hospital Rikshospitalet , Oslo , Norway
| | - Elisabeth Schrumpf
- Norwegian Primary Sclerosing Cholangitis Research Center, Department of Transplantation Medicine, Division of Surgery, Inflammatory Diseases and Transplantation, Oslo University Hospital Rikshospitalet , Oslo , Norway.,Research Institute of Internal Medicine, Division of Surgery, Inflammatory Diseases and Transplantation, Oslo University Hospital , Oslo , Norway.,K.G. Jebsen Inflammation Research Centre, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo , Oslo , Norway
| | - Tom Hemming Karlsen
- Norwegian Primary Sclerosing Cholangitis Research Center, Department of Transplantation Medicine, Division of Surgery, Inflammatory Diseases and Transplantation, Oslo University Hospital Rikshospitalet , Oslo , Norway.,Research Institute of Internal Medicine, Division of Surgery, Inflammatory Diseases and Transplantation, Oslo University Hospital , Oslo , Norway.,K.G. Jebsen Inflammation Research Centre, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo , Oslo , Norway.,Section for Gastroenterology, Department of Transplantation Medicine, Division of Surgery, Inflammatory Diseases and Transplantation, Oslo University Hospital Rikshospitalet , Oslo , Norway.,Institute of Clinical Medicine, Faculty of Medicine, University of Oslo , Oslo , Norway
| | - Pål-Dag Line
- Department of Transplantation Medicine, Division of Surgery, Inflammatory Diseases and Transplantation, Oslo University Hospital Rikshospitalet , Oslo , Norway.,Institute of Clinical Medicine, Faculty of Medicine, University of Oslo , Oslo , Norway
| | - Espen Melum
- Norwegian Primary Sclerosing Cholangitis Research Center, Department of Transplantation Medicine, Division of Surgery, Inflammatory Diseases and Transplantation, Oslo University Hospital Rikshospitalet , Oslo , Norway.,Research Institute of Internal Medicine, Division of Surgery, Inflammatory Diseases and Transplantation, Oslo University Hospital , Oslo , Norway.,K.G. Jebsen Inflammation Research Centre, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo , Oslo , Norway.,Section for Gastroenterology, Department of Transplantation Medicine, Division of Surgery, Inflammatory Diseases and Transplantation, Oslo University Hospital Rikshospitalet , Oslo , Norway
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Benbenishty A, Segev-Amzaleg N, Shaashua L, Melamed R, Ben-Eliyahu S, Blinder P. Maintaining unperturbed cerebral blood flow is key in the study of brain metastasis and its interactions with stress and inflammatory responses. Brain Behav Immun 2017; 62:265-276. [PMID: 28219803 PMCID: PMC5420452 DOI: 10.1016/j.bbi.2017.02.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 02/08/2017] [Accepted: 02/16/2017] [Indexed: 12/15/2022] Open
Abstract
Blood-borne brain metastases are associated with poor prognosis, but little is known about the interplay between cerebral blood flow, surgical stress responses, and the metastatic process. The intra-carotid inoculation approach, traditionally used in animal studies, involves permanent occlusion of the common carotid artery (CCA). Herein we introduced a novel intra-carotid inoculation approach that avoids CCA ligation, namely - assisted external carotid artery inoculation (aECAi) - and compared it to the traditional approach in C57/BL6 mice, assessing cerebral blood flow; particle distribution; blood-brain barrier (BBB) integrity; stress, inflammatory and immune responses; and brain tumor retention and growth. Doppler flowmetry and two-photon imaging confirmed that only in the traditional approach regional and capillary cerebral blood flux were significantly reduced. Corticosterone and plasma IL-6 levels were higher in the traditional approach, splenic numbers of NK, CD3+, granulocytes, and dendritic cells were lower, and many of these indices were more profoundly affected by surgical stress in the traditional approach. BBB integrity was unaffected. Administration of spherical beads indicated that CCA ligation significantly limited brain distribution of injected particles, and inoculation of D122-LLC syngeneic tumor cells resulted in 10-fold lower brain tumor-cell retention in the traditional approach. Last, while most of the injected tumor cells were arrested in extra-cranial head areas, our method improved targeting of brain-tissue by 7-fold. This head versus brain distribution difference, commonly overlooked, cannot be detected using in vivo bioluminescent imaging. Overall, it is crucial to maintain unperturbed cerebral blood flow while studying brain metastasis and interactions with stress and inflammatory responses.
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Affiliation(s)
- Amit Benbenishty
- Sagol School of Neuroscience, Tel Aviv University, Israel; Neurobiology Department, George S. Wise Faculty of Life Sciences, Tel Aviv University, Israel; School of Psychological Sciences, Tel Aviv University, Israel
| | - Niva Segev-Amzaleg
- Neurobiology Department, George S. Wise Faculty of Life Sciences, Tel Aviv University, Israel
| | - Lee Shaashua
- School of Psychological Sciences, Tel Aviv University, Israel
| | - Rivka Melamed
- School of Psychological Sciences, Tel Aviv University, Israel
| | - Shamgar Ben-Eliyahu
- Sagol School of Neuroscience, Tel Aviv University, Israel; School of Psychological Sciences, Tel Aviv University, Israel
| | - Pablo Blinder
- Sagol School of Neuroscience, Tel Aviv University, Israel; Neurobiology Department, George S. Wise Faculty of Life Sciences, Tel Aviv University, Israel.
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4
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Bertrand L, Dygert L, Toborek M. Induction of Ischemic Stroke and Ischemia-reperfusion in Mice Using the Middle Artery Occlusion Technique and Visualization of Infarct Area. J Vis Exp 2017. [PMID: 28190061 DOI: 10.3791/54805] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Cerebrovascular disease is highly prevalent in the global population and encompasses several types of conditions, including stroke. To study the impact of stroke on tissue injury and to evaluate the effectiveness of therapeutic interventions, several experimental models in a variety of species were developed. They include complete global cerebral ischemia, incomplete global ischemia, focal cerebral ischemia, and multifocal cerebral ischemia. The model described in this protocol is based on the middle cerebral artery occlusion (MCAO) and is related to the focal ischemia category. This technique produces consistent focal ischemia in a strictly defined region of the hemisphere and is less invasive than other methods. The procedure described is performed on mice, given the availability of several genetic variants and the high number of tests standardized for mice to aid in the behavioral and neurodeficit evaluation.
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Affiliation(s)
- Luc Bertrand
- Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami; Miller School of Medicine, University of Miami
| | - Levi Dygert
- Miller School of Medicine, University of Miami
| | - Michal Toborek
- Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami; Jerzy Kukuczka Academy of Physical Education;
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5
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Leda AR, Dygert L, Bertrand L, Toborek M. Mouse Microsurgery Infusion Technique for Targeted Substance Delivery into the CNS via the Internal Carotid Artery. J Vis Exp 2017. [PMID: 28190068 DOI: 10.3791/54804] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Animal models of central nervous system (CNS) diseases and, consequently, blood-brain barrier disruption diseases, require the delivery of exogenous substances into the brain. These exogenous substances may induce injurious impact or constitute therapeutic strategy. The most common delivery methods of exogenous substances into the brain are based on systemic deliveries, such as subcutaneous or intravenous routes. Although commonly used, these approaches have several limitations, including low delivery efficacy into the brain. In contrast, surgical methods that locally deliver substances into the CNS are more specific and prevent the uptake of the exogenous substances by other organs. Several surgical methods for CNS delivery are available; however, they tend to be very traumatic. Here, we describe a mouse infusion microsurgery technique, which effectively delivers substances into the brain via the internal carotid artery, with minimal trauma and no interference with normal CNS functionality.
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Affiliation(s)
- Ana R Leda
- Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami
| | - Levy Dygert
- Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami
| | - Luc Bertrand
- Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami
| | - Michal Toborek
- Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami; The Jerzy Kukuczka Academy of Physical Education;
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András IE, Leda A, Contreras MG, Bertrand L, Park M, Skowronska M, Toborek M. Extracellular vesicles of the blood-brain barrier: Role in the HIV-1 associated amyloid beta pathology. Mol Cell Neurosci 2016; 79:12-22. [PMID: 28040512 DOI: 10.1016/j.mcn.2016.12.006] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 12/21/2016] [Accepted: 12/27/2016] [Indexed: 11/20/2022] Open
Abstract
HIV-infected brains are characterized by increased amyloid beta (Aβ) deposition. It is believed that the blood-brain barrier (BBB) is critical for Aβ homeostasis and contributes to Aβ accumulation in the brain. Extracellular vesicles (ECV), like exosomes, recently gained a lot of attention as potentially playing a significant role in Aβ pathology. In addition, HIV-1 hijacks the exosomal pathway for budding and release. Therefore, we investigated the involvement of BBB-derived ECV in the HIV-1-induced Aβ pathology in the brain. Our results indicate that HIV-1 increases ECV release from brain endothelial cells as well as elevates their Aβ cargo when compared to controls. Interestingly, brain endothelial cell-derived ECV transferred Aβ to astrocytes and pericytes. Infusion of brain endothelial ECV carrying fluorescent Aβ into the internal carotid artery of mice resulted in Aβ fluorescence associated with brain microvessels and in the brain parenchyma. These results suggest that ECV carrying Aβ can be successfully transferred across the BBB into the brain. Based on these observations, we conclude that HIV-1 facilitates the shedding of brain endothelial ECV carrying Aβ; a process that may increase Aβ exposure of cells of neurovascular unit, and contribute to amyloid deposition in HIV-infected brain.
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Affiliation(s)
- Ibolya E András
- Department of Biochemistry and Molecular Biology, 1011 NW 15th Street, Gautier Building, Room 528, University of Miami School of Medicine, Miami, FL 33136-1019, USA.
| | - Ana Leda
- Department of Biochemistry and Molecular Biology, 1011 NW 15th Street, Gautier Building, Room 528, University of Miami School of Medicine, Miami, FL 33136-1019, USA
| | - Marta Garcia Contreras
- Diabetes Research Institute, 1450 NW 10th Ave, University of Miami School of Medicine, Miami, FL 33136-1011, USA
| | - Luc Bertrand
- Department of Biochemistry and Molecular Biology, 1011 NW 15th Street, Gautier Building, Room 528, University of Miami School of Medicine, Miami, FL 33136-1019, USA
| | - Minseon Park
- Department of Biochemistry and Molecular Biology, 1011 NW 15th Street, Gautier Building, Room 528, University of Miami School of Medicine, Miami, FL 33136-1019, USA
| | - Marta Skowronska
- Department of Biochemistry and Molecular Biology, 1011 NW 15th Street, Gautier Building, Room 528, University of Miami School of Medicine, Miami, FL 33136-1019, USA
| | - Michal Toborek
- Department of Biochemistry and Molecular Biology, 1011 NW 15th Street, Gautier Building, Room 528, University of Miami School of Medicine, Miami, FL 33136-1019, USA.
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7
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Wrobel JK, Wolff G, Xiao R, Power RF, Toborek M. Dietary Selenium Supplementation Modulates Growth of Brain Metastatic Tumors and Changes the Expression of Adhesion Molecules in Brain Microvessels. Biol Trace Elem Res 2016; 172:395-407. [PMID: 26706037 PMCID: PMC4930949 DOI: 10.1007/s12011-015-0595-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2015] [Accepted: 12/14/2015] [Indexed: 12/26/2022]
Abstract
Various dietary agents can modulate tumor invasiveness. The current study explored whether selenoglycoproteins (SeGPs) extracted from selenium-enriched yeast affect tumor cell homing and growth in the brain. Mice were fed diets enriched with specific SeGPs (SeGP40 or SeGP65, 1 mg/kg Se each), glycoproteins (GP40 or GP65, 0.2-0.3 mg/kg Se each) or a control diet (0.2-0.3 mg/kg Se) for 12 weeks. Then, murine Lewis lung carcinoma cells were infused into the brain circulation. Analyses were performed at early (48 h) and late stages (3 weeks) post tumor cell infusion. Imaging of tumor progression in the brain revealed that mice fed SeGP65-enriched diet displayed diminished metastatic tumor growth, fewer extravasating tumor cells and smaller metastatic lesions. While administration of tumor cells resulted in a significant upregulation of adhesion molecules in the early stage of tumor progression, overexpression of VCAM-1 (vascular call adhesion molecule-1) and ALCAM (activated leukocyte cell adhesion molecule) messenger RNA (mRNA) was diminished in SeGP65 supplemented mice. Additionally, mice fed SeGP65 showed decreased expression of acetylated NF-κB p65, 48 h post tumor cell infusion. The results indicate that tumor progression in the brain can be modulated by specific SeGPs. Selenium-containing compounds were more effective than their glycoprotein controls, implicating selenium as a potential negative regulator of metastatic process.
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Affiliation(s)
- Jagoda K Wrobel
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
| | - Gretchen Wolff
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
| | - Rijin Xiao
- Nutrigenomics Research Center, Alltech, Nicholasville, KY, 40356, USA
| | - Ronan F Power
- Nutrigenomics Research Center, Alltech, Nicholasville, KY, 40356, USA
| | - Michal Toborek
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, 33136, USA.
- Jerzy Kukuczka Academy of Physical Education, Katowice, 40-065, Poland.
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Figueiredo G, Fiebig T, Kirschner S, Nikoubashman O, Kabelitz L, Othman A, Nonn A, Kramer M, Brockmann MA. Minimally Invasive Monitoring of Chronic Central Venous Catheter Patency in Mice Using Digital Subtraction Angiography (DSA). PLoS One 2015; 10:e0130661. [PMID: 26098622 PMCID: PMC4476576 DOI: 10.1371/journal.pone.0130661] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 05/24/2015] [Indexed: 11/18/2022] Open
Abstract
Background Repetitive administration of medication or contrast agents is frequently performed in mice. The introduction of vascular access mini-ports (VAMP) for mice allows long-term vascular catheterization, hereby eliminating the need for repeated vessel puncture. With catheter occlusion being the most commonly reported complication of chronic jugular vein catheterization, we tested whether digital subtraction angiography (DSA) can be utilized to evaluate VAMP patency in mice. Methods Twenty-three mice underwent catheterization of the jugular vein and subcutaneous implantation of a VAMP. The VAMP was flushed every second day with 50 μL of heparinized saline solution (25 IU/ml). DSA was performed during injection of 100 μL of an iodine based contrast agent using an industrial X-ray inspection system intraoperatively, as well as 7±2 and 14±2 days post implantation. Results DSA allowed localization of catheter tip position, to rule out dislocation, kinking or occlusion of a microcatheter, and to evaluate parent vessel patency. In addition, we observed different ante- and retrograde collateral flow patterns in case of jugular vein occlusion. More exactly, 30% of animals showed parent vessel occlusion after 7±2 days in our setting. At this time point, nevertheless, all VAMPs verified intravascular contrast administration. After 14±2 days, intravascular contrast injection was verified in 70% of the implanted VAMPs, whereas at this point of time 5 animals had died or were sacrificed and in 2 mice parent vessel occlusion hampered intravascular contrast injection. Notably, no occlusion of the catheter itself was observed. Conclusion From our observations we conclude DSA to be a fast and valuable minimally invasive tool for investigation of catheter and parent vessel patency and for anatomical studies of collateral blood flow in animals as small as mice.
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Affiliation(s)
- Giovanna Figueiredo
- Department of Diagnostic and Interventional Neuroradiology, University Hospital of the RWTH Aachen, Aachen, Germany
- Department of Neuroradiology, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Teresa Fiebig
- Department of Neuroradiology, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Stefanie Kirschner
- Department of Neuroradiology, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Omid Nikoubashman
- Department of Diagnostic and Interventional Neuroradiology, University Hospital of the RWTH Aachen, Aachen, Germany
| | - Lisa Kabelitz
- Department of Diagnostic and Interventional Neuroradiology, University Hospital of the RWTH Aachen, Aachen, Germany
| | - Ahmed Othman
- Department of Diagnostic and Interventional Neuroradiology, University Hospital of the RWTH Aachen, Aachen, Germany
| | - Andrea Nonn
- Department of Diagnostic and Interventional Neuroradiology, University Hospital of the RWTH Aachen, Aachen, Germany
| | - Martin Kramer
- Department of Veterinary Clinical Sciences, Small Animal Clinic, Justus-Liebig-University, Giessen, Germany
| | - Marc A. Brockmann
- Department of Diagnostic and Interventional Neuroradiology, University Hospital of the RWTH Aachen, Aachen, Germany
- Department of Neuroradiology, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- * E-mail:
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9
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Wolff G, Davidson SJ, Wrobel JK, Toborek M. Exercise maintains blood-brain barrier integrity during early stages of brain metastasis formation. Biochem Biophys Res Commun 2015; 463:811-7. [PMID: 26056010 DOI: 10.1016/j.bbrc.2015.04.153] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Accepted: 04/24/2015] [Indexed: 10/23/2022]
Abstract
Tumor cell extravasation into the brain requires passage through the blood-brain barrier, which is a highly protected microvascular environment fortified with tight junction (TJ) proteins. TJ integrity can be regulated under physiological and pathophysiological conditions. There is evidence that exercise can modulate oxidation status within the brain microvasculature and protect against tumor cell extravasation and metastasis formation. In order to study these events, mature male mice were given access to voluntary exercise on a running wheel (exercise) or access to a locked wheel (sedentary) for five weeks. The average running distance was 9.0 ± 0.2 km/day. Highly metastatic tumor cells (murine Lewis lung carcinoma) were then infused into the brain microvasculature through the internal carotid artery. Analyses were performed at early stage (48 h) and late stage (3 weeks) post tumor cell infusion. Immunohistochemical analysis revealed fewer isolated tumor cells extravasating into the brain at both 48 h and 3 weeks post surgery in exercised mice. Occludin protein levels were reduced in the sedentary tumor group, but maintained in the exercised tumor group at 48 h post tumor cell infusion. These results indicate that voluntary exercise may participate in modulating blood-brain barrier integrity thereby protecting the brain during metastatic progression.
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Affiliation(s)
- Gretchen Wolff
- Department of Biochemistry and Molecular Biology, University of Miami, Miller School of Medicine, 1011 NW 15th, St., Miami, FL 33136, USA.
| | - Sarah J Davidson
- Department of Biochemistry and Molecular Biology, University of Miami, Miller School of Medicine, 1011 NW 15th, St., Miami, FL 33136, USA.
| | - Jagoda K Wrobel
- Department of Biochemistry and Molecular Biology, University of Miami, Miller School of Medicine, 1011 NW 15th, St., Miami, FL 33136, USA.
| | - Michal Toborek
- Department of Biochemistry and Molecular Biology, University of Miami, Miller School of Medicine, 1011 NW 15th, St., Miami, FL 33136, USA; Jerzy Kukuczka Academy of Physical Education, ul. Mikołowska 72a, Katowice 40-065, Poland.
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10
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Cai Q, Chen Z, Kong DK, Wang J, Xu Z, Liu B, Chen Q, Zhou J. Novel microcatheter-based intracarotid delivery approach for MCAO/R mice. Neurosci Lett 2015; 597:127-31. [PMID: 25899778 DOI: 10.1016/j.neulet.2015.04.029] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Revised: 04/15/2015] [Accepted: 04/17/2015] [Indexed: 10/23/2022]
Abstract
The intra-arterial (IA) model by microcatheter administration was an effective way to deliver drugs or cells to the brain. All of these models were carried out introduced in rat rather than mice for the difficult and technically challenging due to their small caliber. In 2014, Alejandro Santillan first introduced this model in mice and we found that most of the operational steps were similar with the middle cerebral artery occlusion and reperfusion (MCAO/R) model. We attempted to combine these two techniques into a single model in mice and discovered that this technique was indeed possible. In our work, 12C57Bl/6J male mice were carried on middle cerebral artery occlusion for 60min and then the intra-arterial microcatheter was placed into the internal carotid artery (ICA) from the external carotid artery (ECA). GFP-Luc-Pro labeled mNSCs were infused through the microcatheter and then the blood flow perfusion was reestablished subsequently. The results showed that all 12 mice were carried on successfully the model of middle cerebral artery occlusion, and the placement of the microcatheter and the mNSCs perfusion were completed smoothly without exception. Which means that it is logical to combine the two models into one in order to facilitate studying of stroke. Meanwhile, during the dissection, we found the variation of occipital artery (OA) was noticeable and we classified first time this variation into four categories to attempt to protect the OA.
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Affiliation(s)
- Qiang Cai
- Department of Neurosurgery, Renmin Hospital of Wuhan University, Wuhan City, Hubei Province, 430060, China; Department of Neurosurgery, Yale University, 333 Cedar Street, FMB 410, New Haven, CT 06520, USA
| | - Zhibiao Chen
- Department of Neurosurgery, Renmin Hospital of Wuhan University, Wuhan City, Hubei Province, 430060, China
| | - Derek Kai Kong
- Department of Neurosurgery, Yale University, 333 Cedar Street, FMB 410, New Haven, CT 06520, USA
| | - Jun Wang
- Department of Neurosurgery, Renmin Hospital of Wuhan University, Wuhan City, Hubei Province, 430060, China
| | - Zhou Xu
- Department of Neurosurgery, Renmin Hospital of Wuhan University, Wuhan City, Hubei Province, 430060, China
| | - Baohui Liu
- Department of Neurosurgery, Renmin Hospital of Wuhan University, Wuhan City, Hubei Province, 430060, China
| | - Qianxue Chen
- Department of Neurosurgery, Renmin Hospital of Wuhan University, Wuhan City, Hubei Province, 430060, China.
| | - Jiangbing Zhou
- Department of Neurosurgery, Yale University, 333 Cedar Street, FMB 410, New Haven, CT 06520, USA
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11
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Foley CP, Rubin DG, Santillan A, Sondhi D, Dyke JP, Crystal RG, Gobin YP, Ballon DJ. Intra-arterial delivery of AAV vectors to the mouse brain after mannitol mediated blood brain barrier disruption. J Control Release 2014; 196:71-78. [PMID: 25270115 PMCID: PMC4268109 DOI: 10.1016/j.jconrel.2014.09.018] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2014] [Revised: 09/13/2014] [Accepted: 09/20/2014] [Indexed: 11/17/2022]
Abstract
The delivery of therapeutics to neural tissue is greatly hindered by the blood brain barrier (BBB). Direct local delivery via diffusive release from degradable implants or direct intra-cerebral injection can bypass the BBB and obtain high concentrations of the therapeutic in the targeted tissue, however the total volume of tissue that can be treated using these techniques is limited. One treatment modality that can potentially access large volumes of neural tissue in a single treatment is intra-arterial (IA) injection after osmotic blood brain barrier disruption. In this technique, the therapeutic of interest is injected directly into the arteries that feed the target tissue after the blood brain barrier has been disrupted by exposure to a hyperosmolar mannitol solution, permitting the transluminal transport of the therapy. In this work we used contrast enhanced magnetic resonance imaging (MRI) studies of IA injections in mice to establish parameters that allow for extensive and reproducible BBB disruption. We found that the volume but not the flow rate of the mannitol injection has a significant effect on the degree of disruption. To determine whether the degree of disruption that we observed with this method was sufficient for delivery of nanoscale therapeutics, we performed IA injections of an adeno-associated viral vector containing the CLN2 gene (AAVrh.10CLN2), which is mutated in the lysosomal storage disorder Late Infantile Neuronal Ceroid Lipofuscinosis (LINCL). We demonstrated that IA injection of AAVrh.10CLN2 after BBB disruption can achieve widespread transgene production in the mouse brain after a single administration. Further, we showed that there exists a minimum threshold of BBB disruption necessary to permit the AAV.rh10 vector to pass into the brain parenchyma from the vascular system. These results suggest that IA administration may be used to obtain widespread delivery of nanoscale therapeutics throughout the murine brain after a single administration.
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Affiliation(s)
- Conor P. Foley
- Department of Radiology, Weill Cornell Medical College, 516 E 72nd Street, New York, NY 10021, USA
| | - David G. Rubin
- Department of Neurosurgery, Weill Cornell Medical College, 525 East 68 Street, New York, NY 10065, USA
| | - Alejandro Santillan
- Department of Neurosurgery, Weill Cornell Medical College, 525 East 68 Street, New York, NY 10065, USA
| | - Dolan Sondhi
- Department of Genetic Medicine, Weill Cornell Medical College, 1305 York Avenue, New York, NY 10021, USA
| | - Jonathan P. Dyke
- Department of Radiology, Weill Cornell Medical College, 516 E 72nd Street, New York, NY 10021, USA
| | - Ronald G. Crystal
- Department of Genetic Medicine, Weill Cornell Medical College, 1305 York Avenue, New York, NY 10021, USA
| | - Y. Pierre Gobin
- Department of Neurosurgery, Weill Cornell Medical College, 525 East 68 Street, New York, NY 10065, USA
| | - Douglas J. Ballon
- Department of Radiology, Weill Cornell Medical College, 516 E 72nd Street, New York, NY 10021, USA
- Department of Genetic Medicine, Weill Cornell Medical College, 1305 York Avenue, New York, NY 10021, USA
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Maniskas M, Bix G, Fraser J. Selective intra-arterial drug administration in a model of large vessel ischemia. J Neurosci Methods 2014; 240:22-7. [PMID: 25445249 DOI: 10.1016/j.jneumeth.2014.10.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 10/21/2014] [Accepted: 10/22/2014] [Indexed: 10/24/2022]
Abstract
With continuing disconnect between laboratory stroke treatment models and clinical stroke therapy, we propose a novel experimental model to study stroke and vessel recanalization that mirrors acute management of large vessel stroke, with concomitant directed pharmacotherapy. Using the tandem transient ipsilateral common carotid/middle cerebral artery occlusion (MCAO) model to induce stroke in mice we then added selective intra-arterial (IA) drug administration for directed pharmacotherapy. The IA model uses micro-angio tubing placed at the bifurcation of the CCA to selectively administer the drug to the internal carotid distribution. We have shown that delivery of pharmacotherapy agents selectively through an IA injection is feasible in a mouse model, which will permit studies involving pharmacotherapy, transgenic modification, and/or a combination. Our IA model has similarities to previously published models of IA injection but differs in that we do not leave an indwelling micro-port or catheter in our animals, which is not clinically relevant as it does not reflect the human condition or current clinical management. Furthermore, we optimized our model to selectively direct therapy to the ipsilateral, stroke affected hemisphere. By developing an IA drug delivery model that mirrors clinical conditions, we are bridging the gap between basic stroke research and what is standard practice in acute ischemic stroke intervention. The IA model of drug delivery can target agents directly to the site of injury while blunting systemic effects, dose penetration issues, and administration delay that have plagued the intraperitoneal and oral drug administration models.
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Affiliation(s)
- Michael Maniskas
- Department of Anatomy & Neurobiology, University of Kentucky, Lexington, KY, United States; Sanders Brown Center on Aging, University of Kentucky, Lexington, KY, United States
| | - Gregory Bix
- Department of Anatomy & Neurobiology, University of Kentucky, Lexington, KY, United States; Sanders Brown Center on Aging, University of Kentucky, Lexington, KY, United States; Department of Neurology, University of Kentucky, Lexington, KY, United States.
| | - Justin Fraser
- Department of Anatomy & Neurobiology, University of Kentucky, Lexington, KY, United States; Department of Neurosurgery, University of Kentucky, Lexington, KY, United States; Department of Neurology, University of Kentucky, Lexington, KY, United States; Department of Radiology, University of Kentucky, Lexington, KY, United States.
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Wolff G, Balke JE, Andras IE, Park M, Toborek M. Exercise modulates redox-sensitive small GTPase activity in the brain microvasculature in a model of brain metastasis formation. PLoS One 2014; 9:e97033. [PMID: 24804765 PMCID: PMC4013134 DOI: 10.1371/journal.pone.0097033] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 04/14/2014] [Indexed: 12/26/2022] Open
Abstract
Tumor cell extravasation into the brain requires passage through the blood-brain barrier (BBB). There is evidence that exercise can alter the oxidation status of the brain microvasculature and protect against tumor cell invasion into the brain, although the mechanisms are not well understood. In the current study, we focused on the role of microenvironment generated by exercise and metastasizing tumor cells at the levels of brain microvessels, influencing oxidative stress-mediated responses and activation of redox-sensitive small GTPases. Mature male mice were exercised for four weeks using a running wheel with the average voluntary running distance 9.0 ± 0.3 km/day. Mice were then infused with 1.0 × 10(6) D122 (murine Lewis lung carcinoma) cells into the brain microvasculature, and euthanized either 48 hours (in short-term studies) or 2-3 weeks (in long-term studies) post tumor cell administration. A significant increase in the level of reactive oxygen species was observed following 48 hours or 3 weeks of tumor cells growth, which was accompanied by a reduction in MnSOD expression in the exercised mice. Activation of the small GTPase Rho was negatively correlated with running distance in the tumor cell infused mice. Together, these data suggest that exercise may play a significant role during aggressive metastatic invasion, especially at higher intensities in pre-trained individuals.
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Affiliation(s)
- Gretchen Wolff
- Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, Miami, Florida, United States of America
| | - Jordan E. Balke
- Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, Miami, Florida, United States of America
| | - Ibolya E. Andras
- Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, Miami, Florida, United States of America
| | - Minseon Park
- Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, Miami, Florida, United States of America
| | - Michal Toborek
- Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, Miami, Florida, United States of America
- Jerzy Kukuczka Academy of Physical Education, Katowice, Poland
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PPAR agonist-mediated protection against HIV Tat-induced cerebrovascular toxicity is enhanced in MMP-9-deficient mice. J Cereb Blood Flow Metab 2014; 34:646-53. [PMID: 24424383 PMCID: PMC3982084 DOI: 10.1038/jcbfm.2013.240] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 11/15/2013] [Accepted: 11/25/2013] [Indexed: 12/19/2022]
Abstract
The strategies to protect against the disrupted blood-brain barrier (BBB) in HIV-1 infection are not well developed. Therefore, we investigated the potential of peroxisome proliferator-activated receptor (PPAR) agonists to prevent enhanced BBB permeability induced by HIV-1-specific protein Tat. Exposure to Tat via the internal carotid artery (ICA) disrupted permeability across the BBB; however, this effect was attenuated in mice treated with fenofibrate (PPARα agonist) or rosiglitazone (PPARγ agonist). In contrast, exposure to GW9662 (PPARγ antagonist) exacerbated Tat-induced disruption of the BBB integrity. Increased BBB permeability was associated with decreased tight junction (TJ) protein expression and activation of ERK1/2 and Akt in brain microvessels; these effects were attenuated by cotreatment with fenofibrate but not with rosiglitazone. Importantly, both PPAR agonists also protected against Tat-induced astrogliosis and neuronal loss. Because disruption of TJ integrity has been linked to matrix metalloproteinase (MMP) activity, we also evaluated Tat-induced effects in MMP-9-deficient mice. Tat-induced cerebrovascular toxicity, astrogliosis, and neuronal loss were less pronounced in MMP-9-deficient mice as compared with wild-type controls and were further attenuated by PPAR agonists. These results indicate that enhancing PPAR activity combined with targeting MMPs may provide effective therapeutic strategies in brain infection by HIV-1.
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Toborek M, Seelbach MJ, Rashid CS, András IE, Chen L, Park M, Esser KA. Voluntary exercise protects against methamphetamine-induced oxidative stress in brain microvasculature and disruption of the blood-brain barrier. Mol Neurodegener 2013; 8:22. [PMID: 23799892 PMCID: PMC3698182 DOI: 10.1186/1750-1326-8-22] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 06/14/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND There is no effective therapeutic intervention developed targeting cerebrovascular toxicity of drugs of abuse, including methamphetamine (METH). We hypothesize that exercise protects against METH-induced disruption of the blood-brain barrier (BBB) by enhancing the antioxidant capacity of cerebral microvessels and modulating caveolae-associated signaling. Mice were subjected to voluntary wheel running for 5 weeks resembling the voluntary pattern of human exercise, followed by injection with METH (10 mg/kg). The frequency, duration, and intensity of each running session were monitored for each mouse via a direct data link to a computer and the running data are analyzed by Clock lab™ Analysis software. Controls included mice sedentary that did not have access to running wheels and/or injections with saline. RESULTS METH induced oxidative stress in brain microvessels, resulting in up regulation of caveolae-associated NAD(P)H oxidase subunits, and phosphorylation of mitochondrial protein 66Shc. Treatment with METH disrupted also the expression and colocalization of tight junction proteins. Importantly, exercise markedly attenuated these effects and protected against METH-induced disruption of the BBB integrity. CONCLUSIONS The obtained results indicate that exercise is an important modifiable behavioral factor that can protect against METH-induced cerebrovascular toxicity. These findings may provide new strategies in preventing the toxicity of drug of abuse.
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A Low Cost Metal-Free Vascular Access Mini-Port for Artifact Free Imaging and Repeated Injections in Mice. PLoS One 2013; 8:e65939. [PMID: 23824056 PMCID: PMC3688803 DOI: 10.1371/journal.pone.0065939] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 05/01/2013] [Indexed: 11/19/2022] Open
Abstract
PURPOSE Small injection ports for mice are increasingly used for drug testing or when administering contrast agents. Commercially available mini-ports are expensive single-use items that cause imaging-artifacts. We developed and tested an artifact-free, low-cost, vascular access mini-port (VAMP) for mice. PROCEDURES Leakage testing of the VAMP was conducted with high speed bolus injections of different contrast agents. VAMP-induced artifacts were assessed using a micro-CT and a small animal MRI (9.4T) scanner ex vivo. Repeated contrast administration was performed in vivo. RESULTS With the VAMP there was no evidence of leakage with repeated punctures, high speed bolus contrast injections, and drawing of blood samples. In contrast to the tested commercially available ports, the VAMP did not cause artifacts with MRI or CT imaging. CONCLUSIONS The VAMP is an alternative to commercially available mini-ports and has useful applications in animal research involving imaging procedures and contrast agent testing.
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TLR4 signaling is involved in brain vascular toxicity of PCB153 bound to nanoparticles. PLoS One 2013; 8:e63159. [PMID: 23690990 PMCID: PMC3653967 DOI: 10.1371/journal.pone.0063159] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Accepted: 03/29/2013] [Indexed: 11/26/2022] Open
Abstract
PCBs bind to environmental particles; however, potential toxicity exhibited by such complexes is not well understood. The aim of the present study is to study the hypothesis that assembling onto nanoparticles can influence the PCB153-induced brain endothelial toxicity via interaction with the toll-like receptor 4 (TLR4). To address this hypothesis, TLR4-deficient and wild type control mice (males, 10 week old) were exposed to PCB153 (5 ng/g body weight) bound to chemically inert silica nanoparticles (PCB153-NPs), PCB153 alone, silica nanoparticles (NPs; diameter, 20 nm), or vehicle. Selected animals were also subjected to 40 min ischemia, followed by a 24 h reperfusion. As compared to exposure to PCB153 alone, treatment with PCB153-NP potentiated the brain infarct volume in control mice. Importantly, this effect was attenuated in TLR4-deficient mice. Similarly, PCB153-NP-induced proinflammatory responses and disruption of tight junction integrity were less pronounced in TLR4-deficient mice as compared to control animals. Additional in vitro experiments revealed that TLR4 mediates toxicity of PCB153-NP via recruitment of tumor necrosis factor-associated factor 6 (TRAF6). The results of current study indicate that binding to seemingly inert nanoparticles increase cerebrovascular toxicity of PCBs and suggest that targeting the TLR4/TRAF6 signaling may protect against these effects.
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Wrobel JK, Seelbach MJ, Chen L, Power RF, Toborek M. Supplementation with Selenium-Enriched Yeast Attenuates Brain Metastatic Growth. Nutr Cancer 2013; 65:563-70. [DOI: 10.1080/01635581.2013.775315] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Davidson DC, Hirschman MP, Sun A, Singh MV, Kasischke K, Maggirwar SB. Excess soluble CD40L contributes to blood brain barrier permeability in vivo: implications for HIV-associated neurocognitive disorders. PLoS One 2012; 7:e51793. [PMID: 23251626 PMCID: PMC3520914 DOI: 10.1371/journal.pone.0051793] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Accepted: 11/08/2012] [Indexed: 02/03/2023] Open
Abstract
Despite the use of anti-retroviral therapies, a majority of HIV-infected individuals still develop HIV-Associated Neurocognitive Disorders (HAND), indicating that host inflammatory mediators, in addition to viral proteins, may be contributing to these disorders. Consistently, we have previously shown that levels of the inflammatory mediator soluble CD40L (sCD40L) are elevated in the circulation of HIV-infected, cognitively impaired individuals as compared to their infected, non-impaired counterparts. Recent studies from our group suggest a role for the CD40/CD40L dyad in blood brain barrier (BBB) permeability and interestingly, sCD40L is thought to regulate BBB permeability in other inflammatory disorders of the CNS. Using complementary multiphoton microscopy and quantitative analyses in wild-type and CD40L deficient mice, we now reveal that the HIV transactivator of transcription (Tat) can induce BBB permeability in a CD40L-dependent manner. This permeability of the BBB was found to be the result of aberrant platelet activation induced by Tat, since depletion of platelets prior to treatment reversed Tat-induced BBB permeability. Furthermore, Tat treatment led to an increase in granulocyte antigen 1 (Gr1) positive monocytes, indicating an expansion of the inflammatory subset of cells in these mice, which were found to adhere more readily to the brain microvasculature in Tat treated animals. Exploring the mechanisms by which the BBB becomes compromised during HIV infection has the potential to reveal novel therapeutic targets, thereby aiding in the development of adjunct therapies for the management of HAND, which are currently lacking.
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Affiliation(s)
- Donna C. Davidson
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, Rochester, New York, United States of America
| | - Michael P. Hirschman
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, Rochester, New York, United States of America
| | - Anita Sun
- Department of Neurology, University of Rochester School of Medicine and Dentistry, Rochester, New York, United States of America
| | - Meera V. Singh
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, Rochester, New York, United States of America
| | - Karl Kasischke
- Department of Neurology, University of Rochester School of Medicine and Dentistry, Rochester, New York, United States of America
- Department of Neurology, University of Ulm Medical Center, Ulm, Germany
| | - Sanjay B. Maggirwar
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, Rochester, New York, United States of America
- * E-mail:
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Cerebrovascular toxicity of PCB153 is enhanced by binding to silica nanoparticles. J Neuroimmune Pharmacol 2012; 7:991-1001. [PMID: 23081707 DOI: 10.1007/s11481-012-9403-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Accepted: 09/09/2012] [Indexed: 12/25/2022]
Abstract
Environmental polychlorinated biphenyls (PCBs) are frequently bound onto nanoparticles (NPs). However, the toxicity and health effects of PCBs assembled onto nanoparticles are unknown. The aim of this study was to study the hypothesis that binding PCBs to silica NPs potentiates PCB-induced cerebrovascular toxicity and brain damage in an experimental stroke model. Mice (C57BL/6, males, 12-week-old) were exposed to PCB153 bound to NPs (PCB153-NPs), PCB153, or vehicle. PCB153 was administered in the amount of 5 ng/g body weight. A group of treated animals was subjected to a 40 min ischemia, followed by a 24 h reperfusion. The blood-brain barrier (BBB) permeability, brain infarct volume, expression of tight junction (TJ) proteins, and inflammatory mediators were assessed. As compared to controls, a 24 h exposure to PCB153-NPs injected into cerebral vasculature resulted in significant elevation of the BBB permeability, disruption of TJ protein expression, increased proinflammatory responses, and enhanced monocyte transmigration in mouse brain capillaries. Importantly, exposure to PCB153-NPs increased stroke volume and potentiated brain damage in mice subjected to ischemia/reperfusion. A long-term (30 days) oral exposure to PCB153-NPs resulted in a higher PCB153 content in the abdominal adipose tissue and amplified adhesion of leukocytes to the brain endothelium as compared to treatment with PCB153 alone. This study provides the first evidence that binding to NPs increases cerebrovascular toxicity of environmental toxicants, such as PCB153.
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Choi JJ, Choi YJ, Chen L, Zhang B, Eum SY, Abreu MT, Toborek M. Lipopolysaccharide potentiates polychlorinated biphenyl-induced disruption of the blood-brain barrier via TLR4/IRF-3 signaling. Toxicology 2012; 302:212-20. [PMID: 22906770 DOI: 10.1016/j.tox.2012.08.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Revised: 07/27/2012] [Accepted: 08/01/2012] [Indexed: 01/22/2023]
Abstract
Exposure to polychlorinated biphenyls (PCBs) is associated with numerous adverse health effects. Although the main route of exposure to PCBs is through the gastrointestinal tract, little is known about the contribution of the gut to the health effects of PCBs. We hypothesize that PCBs can disrupt intestinal integrity, causing lipopolysaccharide (LPS) translocation into the bloodstream and potentiation of the systemic toxicity of PCBs. C57BL/6 mice were exposed to individual PCB congeners by oral gavage, followed by the assessment of small intestine morphology and plasma levels of proinflammatory mediators. In addition, mice and human brain endothelial cells were exposed to PCB118 in the presence or absence of LPS to evaluate the contribution of LPS to PCB-induced toxicity at the blood-brain barrier (BBB) level. Oral administration of PCB153, PCB118, or PCB126 disrupted intestinal morphology and increased plasma levels of LPS and proinflammatory cytokines. Direct injection of LPS and PCB118 into the cerebral microvasculature resulted in synergistic disruption of BBB integrity and decreased expression of tight junction proteins in brain microvessels. In vitro experiments confirmed these effects and indicated that stimulation of the toll-like receptor 4 (TLR4) pathway can be responsible for these effects via activation of interferon regulatory factor-3 (IRF-3). These results indicate that LPS may be a contributing factor in PCB-induced dysfunction of the brain endothelium via stimulation of the TLR4/IRF-3 pathway.
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Affiliation(s)
- Jeong June Choi
- Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, Miami, FL 33136, USA
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22
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Autophagy is involved in nanoalumina-induced cerebrovascular toxicity. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2012; 9:212-21. [PMID: 22687898 DOI: 10.1016/j.nano.2012.05.017] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2011] [Revised: 03/09/2012] [Accepted: 05/31/2012] [Indexed: 11/22/2022]
Abstract
UNLABELLED The current study focused on blood-brain barrier disruption and neurovascular damage induced by engineered nanomaterials. Exposure to nanoalumina, but not to nanocarbon, induced a dose-dependent mitochondrial potential collapse, increased autophagy of brain endothelial cells, and decreased expression of the tight-junction proteins occludin and claudin-5. Inhibition of autophagy by pretreatment with Wortmannin attenuated the effects of nanoalumina on decreased claudin-5 expression; however, it did not affect the disruption of occludin. These findings were confirmed in mice by administration of nanoalumina into the cerebral circulation. Systemic treatment with nanoalumina elevated autophagy-related genes and autophagic activity in the brain, decreased tight-junction protein expression, and elevated blood-brain barrier permeability. Finally, exposure to nanoalumina, but not to nanocarbon, increased brain infarct volume in mice subjected to a focal ischemic stroke model. Overall, our study reveals that autophagy constitutes an important mechanism involved in nanoalumina-induced neurovascular toxicity in the central nervous system. FROM THE CLINICAL EDITOR In this paper, the effects of nanoalumina on the permeability of the blood-brain barrier is reported, suggesting that autophagy is an important mechanism in nanoalumina-induced neurovascular toxicity.
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Sipos E, Chen L, András IE, Wrobel J, Zhang B, Pu H, Park M, Eum SY, Toborek M. Proinflammatory adhesion molecules facilitate polychlorinated biphenyl-mediated enhancement of brain metastasis formation. Toxicol Sci 2012; 126:362-71. [PMID: 22240979 PMCID: PMC3307603 DOI: 10.1093/toxsci/kfr349] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Accepted: 12/20/2011] [Indexed: 11/14/2022] Open
Abstract
Polychlorinated biphenyls (PCBs) are environmental toxicants that cause vascular inflammation and facilitate the development of brain metastases. The crucial event in metastasis formation is adhesion of blood-borne tumor cells to the vascular endothelium, followed by their transcapillary migration. The aim of the present study was to examine the mechanisms of PCB118-induced brain metastasis formation at the blood-brain barrier level with the focus on tumor cell adhesion to the brain endothelium. PCB118 was administered orally to wild-type or intercellular cell adhesion molecule-1 (ICAM-1)-deficient mice, followed by an injection of Lewis lung carcinoma cells into the carotid artery. Treatment with PCB118 resulted in enhanced development of brain metastases. Injection of tumor cells induced overexpression of ICAM-1 and vascular endothelial cell adhesion molecule-1 (VCAM-1) in brain endothelium that was further potentiated in mice exposed to PCB118. PCB118 did not affect the number of adhered and extravasated tumor cells in ICAM-1-deficient mice. Additional in vitro studies indicated that VCAM-1-neutralizing antibody protected against PCB118-induced adhesion of tumor cells to cultured brain endothelial cells. These results indicate that exposure to selected PCB congeners, such as PCB118, induces adhesion and transcapillary migration of tumor cells. This process is facilitated by proinflammatory adhesion molecules and results in potentiation of brain metastasis formation.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Michal Toborek
- To whom correspondence should be addressed at Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, R. Bunn Gautier Building Room 517, 1011 NW 15th Street, Miami, FL 33136. Fax: (305) 243-3955. E-mail:
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Yao H, Buch S. Rodent models of HAND and drug abuse: exogenous administration of viral protein(s) and cocaine. J Neuroimmune Pharmacol 2012; 7:341-51. [PMID: 22447295 DOI: 10.1007/s11481-012-9355-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2011] [Accepted: 03/04/2012] [Indexed: 11/29/2022]
Abstract
Humans and chimpanzees are the natural hosts for HIV. Non-human primate models of SIV/SHIV infection in rhesus, cynomologus and pigtail macaques have been used extensively as excellent model systems for pathogenesis and vaccine studies. However, owing to the variability of disease progression in infected macaques, a phenomenon identical to humans, coupled with their prohibitive costs, there exists a critical need for the development of small-animal models in which to study the untoward effects of HIV-1 infection. Owing to the fact that rodents are not the natural permissive hosts for lentiviral infection, development of small animal models for studying virus infection has used strategies that circumvent the steps of viral entry and infection. Such strategies involve overexpression of toxic viral proteins, SCID mice engrafted with the human PBLs or macrophages, and EcoHIV chimeric virus wherein the gp120 of HIV-1 was replaced with the gp80 of the ecotropic murine leukemia virus. Additional strategy that is often used by investigators to study the toxic effect of viral proteins involves direct stereotactic injection of the viral protein(s) into specific brain regions. The present report is a compilation of the applications of direct administration of Tat into the striatum to mimic the effects of the viral neurotoxin in the CNS. Added advantage of this model is that it is also amenable to repeated intraperitoneal cocaine injections, thereby allowing the study of the additive/synergistic effects of both the viral protein and cocaine. Such a model system recapitulates aspects of HAND in the context of drug abuse.
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Affiliation(s)
- Honghong Yao
- Department of Pharmacology and Experimental Neuroscience, 985880 Nebraska Medical Center, University of Nebraska Medical Center, Omaha, NE 68198-5880, USA
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HIV-1 Tat triggers nuclear localization of ZO-1 via Rho signaling and cAMP response element-binding protein activation. J Neurosci 2012; 32:143-50. [PMID: 22219277 DOI: 10.1523/jneurosci.4266-11.2012] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The human immunodeficiency virus (HIV)-specific protein trans-activator of transcription (Tat) can contribute to the dysfunction of brain endothelial cells and HIV trafficking into the brain by disrupting tight junction (TJ) integrity at the blood-brain barrier (BBB) level. Specific TJ proteins, such as zonula occludens (ZO) proteins, localize not only at the cell-cell borders but are also present in the nuclei. The objective of the present study was to evaluate the mechanisms and significance of Tat-induced nuclear localization of ZO-1. Treatment of a brain endothelial cell line (hCMEC/D3 cells) with Tat resulted in a decrease in total levels of ZO-1 but significantly upregulated ZO-1 protein expression in the nuclei. In addition, exposure to Tat stimulated Rho signaling and induced phosphorylation and activity of transcription factor cAMP response element-binding protein (CREB), binding sites that have been identified in the proximal region of the ZO-1 promoter. Interestingly, inhibition of the Rho cascade protected against Tat-induced upregulation of ZO-1 in the nuclei and activation of CREB. Depletion of CREB by infection of cells with specific shRNA lentiviral particles attenuated both Tat-induced Rho signaling and nuclear targeting of ZO-1. A decrease in CREB levels also attenuated Tat-induced endothelial and BBB hyperpermeability as well as transendothelial migration of monocytic cells. The role of CREB in Tat-mediated alterations of ZO-1 was confirmed in brain microvessels in mice with CREB shRNA lentiviral particles injected into the cerebral circulation. The present results indicate the crucial role of Rho signaling and CREB in modulation of nuclear localization of ZO-1 and maintaining the integrity of endothelial monolayers.
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Platelet-derived growth factor B chain is a novel target gene of cocaine-mediated Notch1 signaling: implications for HIV-associated neurological disorders. J Neurosci 2011; 31:12449-54. [PMID: 21880906 DOI: 10.1523/jneurosci.2330-11.2011] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Neuroinflammation associated with HIV-1 infection is exacerbated in cocaine-abusing, HIV+ individuals. The underlying mechanisms are, in part, attributable to disruption of the blood-brain barrier modulated by cocaine via platelet-derived growth factor B chain (PDGF-B). Since Notch signaling plays a critical role in CNS homeostasis, we hypothesized that it may have a role in cocaine-mediated induction of PDGF-B. The goal of this study was to link Notch signaling with PDGF-B. Using Western blot analysis, we demonstrate the role of Notch1 signaling in cocaine-mediated induction of PDGF-B in human brain microvascular endothelial cells. Exposure of cells to the γ-secretase inhibitor-DAPT or silencing of Notch1 resulted in abrogation of cocaine-mediated induction of PDGF-B. Reciprocally, activation of the Notch1 receptor by exposing cells to the Notch ligand Jagged-1 resulted in upregulation of PDGF-B expression. Furthermore, it was demonstrated that cocaine-mediated activation of Notch1 signaling leading to targeted expression of PDGF-B involved activation of the downstream effector CSL. Functional implication of Notch1 signaling in regulating expression of the vascular permeant PDGF-B was confirmed in vitro using cell permeability assays. In vivo relevance was further corroborated in cocaine-treated mice that demonstrated increased permeability of the endothelial barrier as evidenced by Evans blue and sodium fluorescein extravasation. Specificity of Notch1 signaling in vivo was validated in mice exposed to DAPT, which failed to demonstrate barrier disruption following cocaine exposure. This is the first evidence of involvement of Notch1 activation in cocaine-mediated regulation of PDGF-B expression.
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Shang Y, Chen L, Toborek M, Yu G. Diffuse optical monitoring of repeated cerebral ischemia in mice. OPTICS EXPRESS 2011; 19:20301-15. [PMID: 21997041 PMCID: PMC3495871 DOI: 10.1364/oe.19.020301] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Revised: 09/09/2011] [Accepted: 09/09/2011] [Indexed: 05/18/2023]
Abstract
Occlusions of bilateral common carotid arteries (bi-CCA) in mice are popular models for the investigation of transient forebrain ischemia. Currently available technologies for assessing cerebral blood flow (CBF) and oxygenation in ischemic mice have limitations. This study tests a novel near-infrared diffuse correlation spectroscopy (DCS) flow-oximeter for monitoring both CBF and cerebral oxygenation in mice undergoing repeated transient forebrain ischemia. Concurrent flow measurements in a mouse brain were first conducted for validation purposes; DCS measurement was found highly correlated with laser Doppler measurement (R2 = 0.94) and less susceptible to motion artifacts. With unique designs in experimental protocols and fiber-optic probes, we have demonstrated high sensitivities of DCS flow-oximeter in detecting the regional heterogeneity of CBF responses in different hemispheres and global changes of both CBF and cerebral oxygenation across two hemispheres in mice undergoing repeated 2-minute bi-CCA occlusions over 5 days. More than 75% CBF reductions were found during bi-CCA occlusions in mice, which may be considered as a threshold to determine a successful bi-CCA occlusion. With the progress of repeated 2-minute bi-CCA occlusions over days, a longitudinal decline in the magnitudes of CBF reduction was observed, indicating the brain adaptation to cerebral ischemia through the repeated preconditioning.
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Affiliation(s)
- Yu Shang
- Center for Biomedical Engineering, University of Kentucky, Lexington, Kentucky 40506,
USA
| | - Lei Chen
- Department of Neurosurgery, University of Kentucky, Lexington, Kentucky 40536,
USA
| | - Michal Toborek
- Department of Neurosurgery, University of Kentucky, Lexington, Kentucky 40536,
USA
| | - Guoqiang Yu
- Center for Biomedical Engineering, University of Kentucky, Lexington, Kentucky 40506,
USA
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Chen L, Choi JJ, Choi YJ, Hennig B, Toborek M. HIV-1 Tat-induced cerebrovascular toxicity is enhanced in mice with amyloid deposits. Neurobiol Aging 2011; 33:1579-90. [PMID: 21764480 DOI: 10.1016/j.neurobiolaging.2011.06.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2010] [Revised: 04/04/2011] [Accepted: 06/04/2011] [Indexed: 01/07/2023]
Abstract
HIV-1-infected brains are characterized by elevated depositions of amyloid beta (Aβ); however, the interactions between Aβ and HIV-1 are poorly understood. In the present study, we administered specific HIV-1 protein Tat into the cerebral vasculature of 50-52-week-old double transgenic (B6C3-Tg) mice that express a chimeric mouse/human amyloid precursor protein (Mo/HuAPP695swe) and a mutant human presenilin 1 (PS1-dE9) and are characterized by increased Aβ depositions in the brain. Exposure to Tat increased permeability across cerebral capillaries, enhanced disruption of zonula occludens (ZO)-1 tight junction protein, and elevated brain expression of matrix metalloproteinase-9 (MMP-9) in B6C3-Tg mice as compared with age-matched littermate controls. These changes were associated with increased leukocyte attachment and their transcapillary migration. The majority of Tat-induced effects were attenuated by treatment with a specific Rho inhibitor, hydroxyfasudil. The results of animal experiments were reproduced in cultured brain endothelial cells exposed to Aβ and/or Tat. The present data indicate that increased brain levels of Aβ can enhance vascular toxicity and proinflammatory responses induced by HIV-1 protein Tat.
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Affiliation(s)
- Lei Chen
- Molecular Neuroscience and Vascular Biology Laboratory, Department of Neurosurgery, University of Kentucky, Lexington, KY 40536, USA
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Cocaine-mediated induction of platelet-derived growth factor: implication for increased vascular permeability. Blood 2010; 117:2538-47. [PMID: 21148086 DOI: 10.1182/blood-2010-10-313593] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Neuroinflammation associated with advanced HIV-1 infection is often exacerbated in cocaine-abusing, HIV-infected patients. The underlying mechanisms could, in part, be attributed to the increased impairment of blood brain barrier integrity in the presence of cocaine. Platelet-derived growth factor (PDGF) has been implicated in several pathologic conditions, specifically attributable to its potent mitogenic effects. Its modulation by drug abuse, however, has received very little attention. In the present study, we demonstrated cocaine-mediated induction of PDGF-BB in human brain microvascular endothelial cells through the binding to its cognate σ receptor. Furthermore, this effect was mediated, with subsequent activation of mitogen-activated protein kinases and Egr-1 pathways, culminating ultimately into increased expression of PDGF-BB. Cocaine exposure resulted in increased permeability of the endothelial barrier, and this effect was abrogated in mice exposed to PDGF-BB neutralizing antibody, thus underscoring its role as a vascular permeant. In vivo relevance of these findings was further corroborated in cocaine-treated mice that were administered neutralizing antibody specific for PDGF-BB as well as in Egr-1(-/-) mice. Understanding the regulation of PDGF-BB expression may provide insights into the development of potential therapeutic targets for neuroinflammation associated with HIV infection and drug abuse.
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Seelbach M, Chen L, Powell A, Choi YJ, Zhang B, Hennig B, Toborek M. Polychlorinated biphenyls disrupt blood-brain barrier integrity and promote brain metastasis formation. ENVIRONMENTAL HEALTH PERSPECTIVES 2010; 118:479-84. [PMID: 20064788 PMCID: PMC2854723 DOI: 10.1289/ehp.0901334] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2009] [Accepted: 10/28/2009] [Indexed: 05/14/2023]
Abstract
BACKGROUND Polychlorinated biphenyls (PCBs) comprise a ubiquitous class of toxic substances associated with carcinogenic and tumor-promoting effects as well as neurotoxic properties in the brain. However, the effects of PCBs on the development of tumor metastases are not fully understood. OBJECTIVE We evaluated the hypothesis that exposure to individual PCB congeners can facilitate the development of brain metastases in immunocompetent mice via the disruption of the integrity of the blood-brain barrier (BBB). METHODS C57/Bl6 mice were exposed to individual PCBs by oral gavage, and 48 hr later they were injected with luciferase-labeled K1735 M2 melanoma cells into the internal carotid artery. The development of metastatic nodules was monitored by bioluminescent imaging. In addition, we evaluated the functional permeability of the BBB by measuring permeability of sodium fluorescein across the brain microvessels. Expression and colocalization of tight junction (TJ) proteins were studied by Western blotting and immunofluorescence microscopy. RESULTS Oral administration of coplanar PCB126, mono-ortho-substituted PCB118, and non-coplanar PCB153 (each at 150 micromol/kg body weight) differentially altered expression of the TJ proteins claudin-5, occludin, and zonula occludens-1 in brain capillaries. These alterations were associated with increased permeability of the BBB. Most importantly, exposure to individual PCB congeners enhanced the rate of formation and progression of brain metastases of luciferase-tagged melanoma cells. CONCLUSIONS Our results show for the first time that exposure to individual PCBs can facilitate the formation of bloodborne metastases via alterations of the integrity of the brain capillary endothelium.
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Affiliation(s)
- Melissa Seelbach
- Molecular Neuroscience and Vascular Biology Laboratory, Department of Neurosurgery, University of Kentucky Medical Center, Lexington, Kentucky, USA
| | - Lei Chen
- Molecular Neuroscience and Vascular Biology Laboratory, Department of Neurosurgery, University of Kentucky Medical Center, Lexington, Kentucky, USA
| | - Anita Powell
- Molecular Neuroscience and Vascular Biology Laboratory, Department of Neurosurgery, University of Kentucky Medical Center, Lexington, Kentucky, USA
| | - Yean Jung Choi
- Molecular Neuroscience and Vascular Biology Laboratory, Department of Neurosurgery, University of Kentucky Medical Center, Lexington, Kentucky, USA
| | - Bei Zhang
- Molecular Neuroscience and Vascular Biology Laboratory, Department of Neurosurgery, University of Kentucky Medical Center, Lexington, Kentucky, USA
| | - Bernhard Hennig
- Molecular and Cell Nutrition Laboratory, College of Agriculture, University of Kentucky, Lexington, Kentucky, USA
| | - Michal Toborek
- Molecular Neuroscience and Vascular Biology Laboratory, Department of Neurosurgery, University of Kentucky Medical Center, Lexington, Kentucky, USA
- Address correspondence to M. Toborek, Department of Neurosurgery, Molecular Neuroscience and Vascular Biology Laboratory, University of Kentucky Medical Center, 593 Wethington Building, 900 South Limestone, Lexington, KY 40536 USA. Telephone: (859) 323-4094. Fax: (859) 323-2705. E-mail:
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Huang W, Rha GB, Chen L, Seelbach MJ, Zhang B, András IE, Bruemmer D, Hennig B, Toborek M. Inhibition of telomerase activity alters tight junction protein expression and induces transendothelial migration of HIV-1-infected cells. Am J Physiol Heart Circ Physiol 2010; 298:H1136-45. [PMID: 20139322 DOI: 10.1152/ajpheart.01126.2009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Telomerase, via its catalytic component telomerase reverse transcriptase (TERT), extends telomeres of eukaryotic chromosomes. The importance of this reaction is related to the fact that telomere shortening is a rate-limiting mechanism for human life span that induces cell senescence and contributes to the development of age-related pathologies. The aim of the present study was to evaluate whether the modulation of telomerase activity can influence human immunodeficiency virus type 1 (HIV-1)-mediated dysfunction of human brain endothelial cells (hCMEC/D3 cells) and transendothelial migration of HIV-1-infected cells. Telomerase activity was modulated in hCMEC/D3 cells via small interfering RNA-targeting human TERT (hTERT) or by using a specific pharmacological inhibitor of telomerase, TAG-6. The inhibition of hTERT resulted in the upregulation of HIV-1-induced overexpression of intercellular adhesion molecule-1 via the nuclear factor-kappaB-regulated mechanism and induced the transendothelial migration of HIV-1-infected monocytic U937 cells. In addition, the blocking of hTERT activity potentiated a HIV-induced downregulation of the expression of tight junction proteins. These results were confirmed in TERT-deficient mice injected with HIV-1-specific protein Tat into the cerebral vasculature. Further studies revealed that the upregulation of matrix metalloproteinase-9 is the underlying mechanisms of disruption of tight junction proteins in hCMEC/D3 cells with inhibited TERT and exposed to HIV-1. These results indicate that the senescence of brain endothelial cells may predispose to the HIV-induced upregulation of inflammatory mediators and the disruption of the barrier function at the level of the brain endothelium.
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Affiliation(s)
- Wen Huang
- Dept. of Neurosurgery, Univ. of Kentucky, Lexington, 40536, USA
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