發炎反應是對抗細菌入侵的重要免疫作用之一，而細菌感染所引發的過度發炎，導致腦部的受損，稱為敗血性腦炎 (septic encephalopathy) 。核轉錄因子κB (NF-κB) 是先天性免疫與發炎反應之間的重要調節者。為了想直接在生物體上觀察由細菌引起敗血性腦炎的發炎位置與強度，我們將A群鏈球菌以皮下注射方式，感染先前已建立的冷光報導 NF-κB 活化之小鼠，並之後藉由活體影像系統 (In Vivo Imaging System, IVIS) 觀察宿主發炎情形。結果發現相對於未感染組別在感染48小時之後，除了感染部位有明顯的冷光訊號外，在腦部的位置發現有很強的 NF-κB 活化的冷光訊號。為了進一步了解敗血性腦炎中腦部的病變，如認知、記憶與發燒，所以我們特別將腦部區分出皮質、海馬迴及視丘，並觀測產冷光情形。結果發現，在感染之後這三個區塊都有很強的冷光訊號，並且 NF-κB 所調控的基因，如 TNF-α, IL-1β, KC 與 iNOS ，在感染後都明顯地上升。此外，利用即時聚合酶連鎖反應 (Real-time PCR) 和螢光免疫染色，發現在這三個腦區裡，活化的小神經膠質細胞 (Microglia) 數量上有增加， 但是，活化的星狀神經膠細胞 (Astrocyte) 只有在視丘上增多。同時，各腦區也發現有細胞凋亡的情形出現。在感染之後給予顯性失活 TNF (dominant negative TNF) ，在所有腦區中其 IL-1β 表現會顯著降低且細胞凋亡的細胞數目減少。綜合上述，此研究證實A群鏈球菌所引起的敗血性腦炎，腦部會有 NF-κB 活化、 IL-1β 表現增加、細胞凋亡的細胞數量上升，但是藉由周邊給予 DN-TNF ，則可降低 IL-1β 表現量，並減少腦中細胞凋亡的現象，因此，本篇暗示著細菌感染造成中樞發炎可能是藉由周邊的TNF-α 所引起，並可提供另一個治療人類敗血性腦炎的替代方法。

The inflammation is the pivotal immune responses against bacterial infection. The exaggerated inflammation induced by bacterial infection leads to a severe brain dysfunction, named as septic encephalopathy. Nuclear factor κB (NF-κB) is a critical regulator of innate immunity and inflammatory responses. To directly address the inflammatory state on the spatial and temporal pattern in vivo, we induced septic encephalopathy with group A streptococcus subcutaneously on a previously generated NF-κB-dependent luciferase reporter mouse model. The host-inflammatory reporter signals was examined by the in vivo imaging system (IVIS). Compared to noninfected control mice, the photon intensity of NF-κB activation was emitted in the infected site and reached the peak levels in the brain around 48 h postinfection. To better understand the dysfunction of brain in septic encephalopathy, such as cognitive ability, memory and fever. The brain was separated into three regions, cortex, hippocampus and thalamus, and imaged ex vivo. We found the NF-κB activation signal was emitted in all region. NF-κB-regulated genes, such as TNF-α ,IL-1β, KC and iNOS, were significant elevated in these three brain regions. Using real-time PCR analysis and immunofluorescence staining, the number of activated microglia was also increased in this three brain regions. The activation of astrocyte was found in thalamus especially. Apoptosis monitored by activated-caspoase-3 was found in these three brain regions. After treatment with dominant negative tumor necrosis factor (DN-TNF) together with streptococcal infection, the IL-1β expression was significantly blockage and activated-caspoase-3 positive cells were decreased in three brain region. Taken together, our findings demonstrated that subcutaneous streptococcal infection induced septic encephalopathy through brain NF-κB activation, IL-1β expression, and following increased apoptotic cell in brain. Meanwhile, these central inflammatory responses and streptococcal-induced death can be blocked by peripheral injected DN-TNF, implicating that bacterial infection may activate central NF-κB via circulating TNF-α and provide an alternative therapeutic strategy for human septic encephalopathy.

1.Kawai T, Akira S., Innate immune recognition of viral infection. Nature Immunology 7 (2), 131–7 (2006).
2.DiCarlo EF, Kahn LB., Inflammatory diseases of the bones and joints. Semin Diagn Pathol 28(1), 53-64 (2011)
3.Becker J, Delayre-Orthez C, Frossard N, Pons F., Regulation of inflammation by PPARs: a future approach to treat lung inflammatory diseases? Fundam Clin Pharmacol 20(5), 429-47 (2006)
4.Swierkot J, Szechiński J., Methotrexate in rheumatoid arthritis. Pharmacol Rep 58(4), 473-92(2006)
5.Pytel P, Alexander JJ., Pathogenesis of septic encephalopathy. Curr Opin Neurol 22(3),283-7(2009)
6.Davies, D.C., Blood–brain barrier breakdown in septic encephalopathy and brain tumours. J. Anat 200, 639 (2002)
7.Boos, L., Szalai, A.J., Barnum, S.R., C3a expressed in the central nervous system protects against LPS-induced shock. Neurosci. Lett 387, 68 (2005)
8.Bartynski, W.S., Boardman, J.F., Zeigler, Z.R., Shadduck, R.K., Lister, J., Posterior reversible encephalopathy syndrome in infection, sepsis, and shock. AJNR Am. J.Neuroradiol 27, 2179 (2006)
9.Gardenfors, A., Nilsson, F., Skagerberg, G., Ungerstedt, U., Nordstrom, C.H., Cerebral physiological and biochemical changes during vasogenic brain oedema induced by intrathecal injection of bacterial lipopolysaccharides in piglets. Acta Neurochir. 144, 601.(2002)
10.Girvin AM, Gordon KB, Welsh CJ, Clipstone NA, Miller SD., Differential abilities of central nervous system resident endothelial cells and astrocytes to serve as inducible antigen-presenting cells.Blood 15;99(10), 3692-701 (2002)
11.Ebersoldt, M., Sharshar, T., Annane, D., Sepsis-associated delirium. Intensive Care Med 33, 941 (2007)
12.Alexander JJ, Jacob A, Cunningham P, Hensley L, Quigg RJ., TNF is a key mediator of septic encephalopathy acting through its receptor, TNF receptor-1. Neurochem Int 52(3), 447-56 (2008)
13.Gabrielian L, Willshire L, Helps S, van den Heuvel C, Mathias J, Vink R., Intracranial Pressure Changes Following Traumatic Brain Injury in Rats: Lack of Significant Change in the Absence of Mass Lesions or Hypoxia. J Neurotrauma (2011)
14.Imamura Y, Wang H, Matsumoto N, Muroya T, Shimazaki J, Ogura H, Shimazu T., Interleukin-1β causes long-term potentiation deficiency in a mouse model of septic encephalopathy. Neuroscience 28,187:63-9 (2011)
15.Hallsworth MP, Soh CP, Lane SJ, Arm JP, Lee TH., Selective enhancement of GM-CSF, TNF-alpha, IL-1 beta and IL-8 production by monocytes and macrophages of asthmatic subjects. Eur Respir J 7(6), 1096-102 (1994)
16.Rossi S, Furlan R, Chiara VD, Muzio L, Musella A, Motta C, Studer V, Cavasinni F, Bernardi G, Martino G, Cravatt BF, Lutz B, Maccarrone M, Centonze D., Cannabinoid CB1 receptors regulate neuronal TNF-α effects in experimental autoimmune encephalomyelitis. Brain Behav Immun. 2011
17.Galeazzi M, Gasbarrini G, Ghirardello A, Grandemange S, Hoffman HM, Manna R, Podswiadek M, Punzi L, Sebastiani GD, Touitou I, Doria A., Autoinflammatory syndromes. Clin Exp Rheumatol 24, 79-85 (2006)
18.Hatano E., Tumor necrosis factor signaling in hepatocyte apoptosis. J Gastroenterol Hepatol 1:S43-4 (2007)
19.Holoch PA, Griffith TS., TNF-related apoptosis-inducing ligand (TRAIL): a new path to anti-cancer therapies. Eur J Pharmacol 25;625(1-3),63-72 (2009)
20.Roy D, Sarkar S, Felty Q., Levels of IL-1 beta control stimulatory/inhibitory growth of cancer cells. Front Biosci 1;11, 889-98 (2006)
21.Okamoto M, Ono M, Baba M., Potent inhibition of HIV type 1 replication by an antiinflammatory alkaloid, cepharanthine, in chronically infected monocytic cells. AIDS Res Hum Retroviruses 20;14(14), 1239-45 (1998)
22.Solerte SB, Cravello L, Ferrari E, Fioravanti M., Overproduction of IFN-gamma and TNF-alpha from natural killer (NK) cells is associated with abnormal NK reactivity and cognitive derangement in Alzheimer's disease. Ann N Y Acad Sci 917, 331-40 (2000)
23.Leirisalo-Repo M, Paimela L, Jäättelä M, Koskimies S, Repo H., Production of TNF by monocytes of patients with early rheumatoid arthritis is increased. Scand J Rheumatol 24(6), 366-71 (1995)
24.Bel Hadj Jrad B, Chatti A, Laatiri A, Ahmed SB, Romdhane A, Ajimi S, Chouchane L., Tumor necrosis factor promoter gene polymorphism associated with increased susceptibility to non-Hodgkin's lymphomas. Eur J Haematol 78(2), 117-22 (2007)
25.Kast RE, Altschuler EL., Anti-apoptosis function of TNF-alpha in chronic lymphocytic leukemia: lessons from Crohn's disease and the therapeutic potential of bupropion to lower TNF-alpha. Arch Immunol Ther Exp (Warsz) 53(2),143-7 (2005).
26.Nishioku T, Matsumoto J, Dohgu S, Sumi N, Miyao K, Takata F, Shuto H, Yamauchi A, Kataoka Y., Tumor necrosis factor-alpha mediates the blood-brain barrier dysfunction induced by activated microglia in mouse brain microvascular endothelial cells. J Pharmacol Sci 112(2), 251-4 (2010)
27.Montgomery SL, Bowers WJ., Tumor Necrosis Factor-alpha and the Roles it Plays in Homeostatic and Degenerative Processes Within the Central Nervous System. J Neuroimmune Pharmacol 2011
28.Fawcett JW, Asher RA. The glial scar and central nervous system repair. Brain Res Bull 49(6), 377-91 (1999)
29.Meeks JP, Mennerick S., Feeding hungry neurons: astrocytes deliver food for thought. Neuron 37(2), 187-9 (2003)
30.Eng LF, Ghirnikar RS, Lee YL., Glial fibrillary acidic protein: GFAP-thirty-one years Neurochem. Res 25, 1439–1451 (2000)
31.Eng LF, Yu AC, Lee YL., Astrocytic response to injury. Prog. Brain Res 94, 353–365 (1992)
32.Askalan R, Deveber G, Ho M, Ma J, Hawkins C., Astrocyticinducible nitric oxide synthase in the ischemic developing human brain. Pediatr. Res 60, 687–692 (2006)
33.Enkhbaatar P, Cox R, Traber LD, Maybauer MO, Maybauer DM, Nakano YY, Hawkins H, Schmalstieg F, Herndon D, Traber D., Role of inducible nitric oxide synthase in septic shock. FASEB. J 20, A1391 (2006)
34.Hawkins RD, Son H, Arancio O., Nitric oxide as a retrograde messenger during long-term potentiation in hippocampus. Nitric Oxide Brain Dev. Plast. Dis 118, 155–172 (1998)
35.Rao KV, Jayakumar AR, Reddy PV, Tong X, Curtis KM, Norenberg MD., Aquaporin-4 in manganese-treated cultured astrocytes. Glia 58(12), 1490-9 (2010)
36.Dubin A, Murias G, Sottile JP., Effects of levosimendan and dobutamine in experimental acute endotoxemia: a preliminary controlled study. Intensive Care Med 33, 485–494(2007)
37.Levy RJ, Deutschman CS., Cytochrome c oxidase dysfunction in sepsis. Crit Care Med 35,S468–S475 (2007)
38.Baumgart K, Simkova V, Wagner F., Effect of SOD-1 over-expression on myocardial function during resuscitated murine septic shock. Intensive Care Med 35:344–349 (2009).
39.Cunningham MW., Pathogenesis of group A streptococcal infections and their sequelae. Adv Exp Med Biol 609:29-42 (2008)
40.Cunningham MW., Pathogenesis of group A streptococcal infections. Clin Microbiol Rev 3(3),470-511 (2000)
41.Yoshizawa N, Yamakami K, Fujino M, Oda T, Tamura K, Matsumoto K, Sugisaki T, Boyle MD., Nephritis-associated plasmin receptor and acute poststreptococcal glomerulonephritis: characterization of the antigen and associated immune response. J Am Soc Nephrol 15(7), 1785-93(2004)
42.Dale RC., Post-streptococcal autoimmune disorders of the central nervous system. Dev Med Child Neurol 47, 785-91 (2005)
43.Lynch NE, Deiratany S, Webb DW, McMenamin JB., PANDAS (Paediatric Autoimmune Neuropsychiatric Disorder Associated with Streptococcal Infection). Ir Med J 99(5), 155 (2006)
44.Majcherczyk PA, Langen H, Heumann D, Fountoulakis M, Glauser MP, Moreillon P., Digestion of Streptococcus pneumoniae cell walls with its major peptidoglycan hydrolase releases branched stem peptides carrying proinflammatory activity. J Biol Chem 30;274(18), 12537-43 (1999)
45.Tsao N, Hsu HP, Wu CM, Liu CC, Lei HY., Tumour necrosis factor-alpha causes an increase in blood-brain barrier permeability during sepsis. J Med Microbiol 50(9), 812-21(2001)
46.Young GB,Bolton CF,Austin TW., The encephalopathy associated with septic illness. Clin Invest Med 13(6), 297-304 (1990)
47.Zauner C,Gendo A,Kramer L., Impaired subcortical and cortical sensory evoked potential pathways in septic patients. Crit Care Med 30(5), 1136-1139 (2002)
48.Szatmári S, Végh T, Antek C., Sepsis-associated encephalopathy. Orv Hetil 151(33), 1340-1346 (2010)
49.Henkel JS, Beers DR, Zhao W, Appel SH., Microglia in ALS: the good, the bad, and the resting. J Neuroimmune Pharmacol 4(4), 389-98 (2009)
50.Sorce S, Krause KH., NOX enzymes in the central nervous system: from signaling to disease. Antioxid Redox Signal 11(10), 2481-504 (2009)
51.Tsai, P.J., Chen, Y.H., Hsueh, C.H., Hsieh, C.H., Liu, Y.H., Wu, J.J. and Tsou, C.C., Streptococcus pyogenes induces epithelial inflammatory responses through NF-kB/MAPK signaling pathways. Microbes & Infect 8,1440-1449 (2006)
52.Schröder NW, Morath S, Alexander C, Hamann L, Hartung T, Zähringer U, Göbel UB, Weber JR, Schumann RR., Lipoteichoic acid (LTA) of Streptococcus pneumoniae and Staphylococcus aureus activates immune cells via Toll-like receptor (TLR)-2, lipopolysaccharide-binding protein (LBP), and CD14, whereas TLR-4 and MD-2 are not involved. J Biol Chem 2;278(18), 15587-94 (2003)
53.Chang YC, Huang CC, Wang ST, Liu CC, Tsai JJ., Risk factors analysis for early fatality in children with acute bacterial meningitis. Pediatr Neurol 18(3), 213-7 (1998)
54.Liu CC, Chen JS, Lin CH, Chen YJ, Huang CC., Bacterial meningitis in infants and children in southern Taiwan: emphasis on Haemophilus influenzae type B infection. J Formos Med Assoc 92(10), 884-8 (1993)
55.J. Emerit, M. Edeas, F. Bricaire., Neurodegenerative diseases and oxidative stress. Biomedicine & Pharmacotherapy 58, 39–46(2004)
56.Apkarian AV, Lavarello S, Randolf A, Berra HH, Chialvo DR, Besedovsky HO, del Rey A., Expression of IL-1beta in supraspinal brain regions in rats with neuropathic pain. Neurosci Lett 23;407(2), 176-81 (2006)
57.Depuydt B , Van Loo G, Vandenabeele P., Induction of apoptosis by TNF receptor 2 in a T2cell hybridoma is FADD dependent and blocked by caspase 8 inhibitors. J Cell Sci 118, 497-504 (2005)
58.Grech AP, Gardam S, Chan T, Quinn R, Gonzales R, Basten A, Brink R., Tumor necrosis factor receptor 2 (TNFR2) signaling is negatively regulated by a novel, carboxyl-terminal TNFR-associated factor 2 (TRAF2)-binding site. J Biol Chem 280(36), 31572-81 (2005)
59.GEORGR PAXINOS 撰 The Mouse Brain 2001 ISBN: 0-12-547637-X
60.吳佩樺 撰, 研究A群鏈球菌引發中樞 NF-B 活化所媒介之發炎反應 國立成功大學 微生物暨免疫學研究所碩士論文 中華民國九十九年七月
61.Lefkowitz DL, Lefkowitz SS., Microglia and myeloperoxidase: a deadly partnership in neurodegenerative disease. Free Radic Biol Med 1;45(5), 726-31 (2008)
62.Green PS, Mendez AJ, Jacob JS, Crowley JR, Growdon W, Hyman BT, Heinecke JW., Neuronal expression of myeloperoxidase is increased in Alzheimer's disease. J Neurochem 90(3), 724-33 (2004)
63.Argaw AT, Zhang Y, Snyder BJ, Zhao ML, Kopp N, Lee SC, Raine CS, Brosnan CF, John GR., IL-1beta regulates blood-brain barrier permeability via reactivation of the hypoxia-angiogenesis program. J Immunol 15;177(8),5574-84 (2006)
64.Ferrer I, Bernet E, Soriano E, del Rio T, Fonseca M., Naturally occurring cell death in the cerebral cortex of the rat and removal of dead cells by transitory phagocytes. Neuroscience 39(2):451-8 (1990)
65.Gehrmann J, Matsumoto Y, Kreutzberg GW., Microglia: intrinsic immuneffector cell of the brain. Brain Res Brain Res Rev 20(3), 269-87 (1995)
66.Ritter MR, Banin E, Moreno SK, Aguilar E, Dorrell MI, Friedlander M., Myeloid progenitors differentiate into microglia and promote vascular repair in a model of ischemic retinopathy. J Clin Invest 116(12), 3266-76 (2006)
67.Figley CR, Stroman PW., The role(s) of astrocytes and astrocyte activity in neurometabolism, neurovascular coupling, and the production of functional neuroimaging signals. Eur J Neurosci 33(4), 577-88 (2011)
68.Persidsky Y, Ramirez SH, Haorah J, Kanmogne GD., Blood-brain barrier: structural components and function under physiologic and pathologic conditions. J Neuroimmune Pharmacol 1(3), 223-36 (2006)
69.Nilsson M, Pekny M., Enriched environment and astrocytes in central nervous system regeneration. J Rehabil Med. 39(5), 345-52 (2007)
70.Moore CS, Abdullah SL, Brown A, Arulpragasam A, Crocker SJ., How factors secreted from astrocytes impact myelin repair. J Neurosci Res 89, 13-21 (2011)
71.Parri HR, Crunelli V. Astrocytes, spontaneity, and the developing thalamus. J Physiol Paris 96(3-4):221-30 (2002)
72.Aliev G, Palacios HH, Lipsitt AE, Fischbach K, Lamb BT, Obrenovich ME, Morales L, Gasimov E, Bragin V., Nitric oxide as an initiator of brain lesions during the development of Alzheimer disease. Neurotox Res 16(3), 293-305 (2009)
73.Mahr S, Neumayer N, Gerhard M, Classen M, Prinz C., IL-1beta-induced apoptosis in rat gastric enterochromaffin-like cells is mediated by iNOS, NF-kappaB, and Bax protein. Gastroenterology 118(3), 515-24 (2000)
74.Palin K, Verrier D, Tridon V, Hurst J, Perry VH, Dantzer R, Lestage J., Influence of the course of brain inflammation on the endogenous IL-1beta/IL-1Ra balance in the model of brain delayed-type hypersensitivity response to bacillus Calmette-Guérin in Lewis rats. J Neuroimmunol 149(1-2):22-30 (2004)
75.Mouihate A, Chen X, Pittman QJ., Interleukin-1beta fever in rats: gender difference and estrous cycle influence. Am J Physiol 275(52), 1450-4 (1998)