Kvantifisering av Cerebral Vascular Architecture ved hjelp av to-foton mikroskopi i en musemodell for HIV-indusert nevroinflammasjon
Summary
This paper describes a method by which the vascular architecture in the brain can be quantified using in vivo and ex vivo two-photon microscopy.
Abstract
Human Immunodeficiency Virus 1 (HIV-1) infection frequently results in HIV-1 Associated Neurocognitive Disorders (HAND), and is characterized by a chronic neuroinflammatory state within the central nervous system (CNS), thought to be driven principally by virally-mediated activation of microglia and brain resident macrophages. HIV-1 infection is also accompanied by changes in cerebrovascular blood flow (CBF), raising the possibility that HIV-associated chronic neuroinflammation may lead to changes in CBF and/or in cerebral vascular architecture. To address this question, we have used a mouse model for HIV-induced neuroinflammation, and we have tested whether long-term exposure to this inflammatory environment may damage brain vasculature and result in rarefaction of capillary networks. In this paper we describe a method to quantify changes in cortical capillary density in a mouse model of neuroinflammatory disease (HIV-1 Tat transgenic mice). This generalizable approach employs in vivo two-photon imaging of cortical capillaries through a thin-skull cortical window, as well as ex vivo two-photon imaging of cortical capillaries in mouse brain sections. These procedures produce images and z-stack files of capillary networks, respectively, which can be then subjected to quantitative analysis in order to assess changes in cerebral vascular architecture.
Introduction
Humant immunsviktvirus 1 (HIV-1) invaderer hjernen under den akutte fasen av virusinfeksjon, og produktivt infiserer både mikroglia og hjernen bosatt makrofager, som fører til aktivering deres – og utgivelsen av både vert-avledet inflammatoriske mediatorer og løselig HIV-1 virotoxins som Tat og gp120 (anmeldt i 1,2). Som en konsekvens av dette, blir en kronisk neuroinflammatoriske tilstand etableres i CNS, som antas å bidra til patogenesen av HIV-1-Associated nevropsykologiske forstyrrelser (for hånd) 3-5.
Kronisk overekspresjon av HIV-1 Tat eller interleukin (IL) -17A i CNS hos mus har vist seg å resultere i mikrovaskulær vakuum, 6,7. Dette øker muligheten for at kronisk nevroinflammasjon kan bidra til patogenesen av HAND gjennom effekter på hjernens blodforsyning. For ytterligere å undersøke dette spørsmålet, har vi utviklet metoder for å kvantifisere cerebral vaskulær struksteder.
Dette dokumentet beskriver en fremgangsmåte for å kvantifisere antall kapillære noder, kapillar-segmenter, betyr segmentlengde, total segmentlengde, betyr kapillær diameter, og total kapillær volum ved hjelp av in vivo avbildning av kapillære nettverk gjennom en tynn skull kortikal vindu (modifisert fra tidligere beskrevne protokoller) 8,9, samt ex vivo avbildning av hjernen seksjoner, ved hjelp av to-foton mikroskopi. Denne kombinerte metode gir en helhetlig kvantifisering av cerebrale vaskulære parametere, ettersom in vivo tynne skalle cortical vindu gjør det mulig for bevaring av cerebral miljø, mens ex vivo avbildning av kapillære nettverk i hjerneskiver muliggjør rekonstruksjon av fullstendige, tredimensjonale kapillær nettverk – som deretter kan kvantifiseres ved hjelp av kommersielt tilgjengelig programvare.
Protocol
Representative Results
Discussion
Metoden som beskrives her kan brukes til å analysere hjernen mikrovaskulære strukturer i et bredt spekter av eksperimentelle modeller / innstillinger. For å lykkes med denne metoden, må mestres tre kritiske trinn. For det første må den tynne skallen vinduet ikke skade kraniet eller underliggende hjernen. Det er lett å punktere skallen under tynning, eller føre til varme indusert vaskulær lekkasje. Dette kan forstyrre avbildning som det fluorescerende fargestoff vil lekke inn i fokusplanet og overskygge de kapil…
Divulgazioni
The authors have nothing to disclose.
Acknowledgements
We thank Maria Jepson, Dr. Paivi Jordan, and Dr. Linda Callahan at the University of Rochester Multiphoton Core for technical advice throughout the completion of this protocol. We also thank Dr. Changyong Feng for expert statistical advice, and Dr. Maiken Nedergaard at the University of Rochester Medical Center for the headplate design used in this paper. This work was supported in part by grants T32GM007356 and R01DA026325 from the National Institutes of Health (NIH); and by the University of Rochester Center for AIDS Research grant P30AI078498 (NIH).
Materials
| Leica Microscope | Leica Inc. | MZ8 | |
| High Intensity Illuminator | Dolan-Jenner | 180 | |
| Heating Pad | Stryker | TP3E | |
| T/PUMP | Gaymar Industries, Inc. | TP-500 | |
| TEC-4 Isoflurane Vaporizer | Datex Ohmeda | 447 | |
| Artificial Tear Gel | Butler AHS | 7312 | |
| Povidone-Iodine solution | Aplicare | 52380-1855-9 | |
| Extra Fine Bonn Scissors | Fine Science Tools | 14084-08 | |
| Dumot #5 Forceps | Fine Science Tools | 11295-10 | |
| Dumont #5/45 Forceps | Fine Science Tools | 11251-35 | |
| Ferric Chloride Solution | Ricca Chemical Company | 3120-16 | |
| Loctite 454 Prism Instant Adhesive Gel | Henkel | 45404 | |
| Dental Cement | Stoelting | 51459 | |
| Microtoruqe II Handpiece Kit | Pearson Dental | R14-0002 | |
| 005 Burr for Micro Drill | Fine Science Tools | 19007-05 | |
| Norland Blade (Dental Microblade) | Salvin Dental | 6900 | |
| Urethane | Sigma-Aldrich | U2500 | Group 2B Carcinogen |
| Braided Suture | Ethicon | 735G | |
| Vannas Spring Scissors | Fine Science Tools | 15000-03 | |
| Arterial Catheter | SAI Infusion Technologies | MAC-01 | The end of the catheter was manually stretched out in order to decrease its diameter. |
| Blood Pressure Moniter | World Precision Intruments | SYS-BP1 | |
| Blood Pressure Transducer and Cable | World Precision Intruments | BLPR2 | |
| RAPIDLab Blood Gas Analyzer | Siemens | 248 | |
| 40 μl Capillary Tube | VWR | 15401-413 | |
| Texas Red-dextran (70,000 MW, 10 mg/kg dissolved in saline) | Invitrogen | D-1830 | |
| Adult Mouse Brain Slicer Matrix | Zivic Instruments | BSMAS001-1 | |
| Olympus Fluoview 1000 AOM-MPM Multiphoton Microscope | Olypmus | FV-1000 MPE | |
| MaiTai HP DeepSee Ti:Sa laser | Spectra-Physics | ||
| ImageJ Software | National Institutes of Health (NIH) | Available at http://rsb.info.nih.gov/ij/download.html | |
| Amira Software | Visage Imaging |
Riferimenti
- Kraft-Terry, S. D., Buch, S. J., Fox, H. S., Gendelman, H. E. A coat of many colors: neuroimmune crosstalk in human immunodeficiency virus infection. Neuron. 64 (1), 133-145 (2009).
- Ghafouri, M., Amini, S., Khalili, K., Sawaya, B. E. HIV-1 associated dementia: symptoms and causes. Retrovirology. 3, 28 (2006).
- Antinori, A., et al. Updated research nosology for HIV-associated neurocognitive disorders. Neurology. 69 (18), 1789-1799 (2007).
- Clifford, D. B., Ances, B. M. HIV-associated neurocognitive disorder. The Lancet. Infectious diseases. 13 (11), 976-986 (2013).
- Lindl, K. A., Marks, D. R., Kolson, D. L., Jordan-Sciutto, K. L. HIV-associated neurocognitive disorder: pathogenesis and therapeutic opportunities. Journal of neuroimmune pharmacology : the official journal of the Society on NeuroImmune Pharmacology. 5 (3), 294-309 (2010).
- Zimmermann, J., et al. CNS-targeted production of IL-17A induces glial activation, microvascular pathology and enhances the neuroinflammatory response to systemic endotoxemia. PloS one. 8 (2), e57307 (2013).
- Silva, J. N., et al. Chronic central nervous system expression of HIV-1 Tat leads to accelerated rarefaction of neocortical capillaries and loss of red blood cell velocity heterogeneity. Microcirculation. 21 (7), 664-676 (2014).
- Marker, D. F., Tremblay, M. E., Lu, S. M., Majewska, A. K., Gelbard, H. A. A thin-skull window technique for chronic two-photon in vivo imaging of murine microglia in models of neuroinflammation. Journal of visualized experiments : JoVE. (43), (2010).
- Kleinfeld, D., Mitra, P. P., Helmchen, F., Denk, W. Fluctuations and stimulus-induced changes in blood flow observed in individual capillaries in layers 2 through 4 of rat neocortex. Proceedings of the National Academy of Sciences of the United States of America. 95 (26), 15741-15746 (1998).
- Bruce-Keller, A. J., et al. Morphine causes rapid increases in glial activation and neuronal injury in the striatum of inducible HIV-1 Tat transgenic mice. Glia. 56 (13), 1414-1427 (2008).
- Zoumi, A., Yeh, A., Tromberg, B. J. Imaging cells and extracellular matrix in vivo by using second-harmonic generation and two-photon excited fluorescence. Proceedings of the National Academy of Sciences of the United States of America. 99 (17), 11014-11019 (2002).
- Silva, J., et al. Transient hypercapnia reveals an underlying cerebrovascular pathology in a murine model for HIV-1 associated neuroinflammation: role of NO-cGMP signaling and normalization by inhibition of cyclic nucleotide phosphodiesterase-5. Journal of neuroinflammation. 9, 253 (2012).
- Farber, N. E., et al. Region-specific and agent-specific dilation of intracerebral microvessels by volatile anesthetics in rat brain slices. Anesthesiology. 87 (5), 1191-1198 (1997).
