過敏性氣喘是一種慢性呼吸道疾病，目前有許多研究指出，局部微環境中的活性氧化物(Reactive oxygen species, ROS)能造成細胞的氧化性傷害，極有可能參與致敏的過程，而且在肺臟發炎過程中，體內氧化劑與抗氧化劑的不平衡，是引發細胞損害的一重要因素。N-Acetylcysteine (NAC)屬於intracellular thiol antioxidants，可以透過增加細胞內glutathione的濃度、降低NF-kB活性或透過直接清除free radical而達到抗氧化的能力。因此我希望利用兩種家塵蟎致敏小鼠的氣喘動物模式：分別是以週邊致敏模式和經呼吸道致敏模式來探討是否可藉NAC去除氧化性傷害，而抑制家塵螨所引發的肺部過敏性發炎反應。
首先在周邊致敏模式中，Der f/Alum致敏小鼠後肺泡沖洗液細胞總數、肺泡巨噬細胞、淋巴球、嗜中性球和嗜酸性球都明顯增加，且產生大量的O2-，顯示小鼠肺部處於慢性發炎反應，小鼠血清中Der f特異性IgG1抗體也明顯增加，表示免疫反應偏向Th2型。致敏小鼠經塵蟎激發後給予NAC會減少肺泡沖洗液中細胞浸潤情形，血液中的嗜酸性球亦減少，但是血清中Der f特異性IgG1抗體以及淋巴球的增生都沒有減少，顯示NAC能抑制Der f所引發的發炎反應，但是無法調控塵蟎的致敏過程。
在呼吸道致敏模式中，Der f同樣也會引起小鼠肺部發炎反應、血液中產生大量O2-和血清中Der f特異性IgG1抗體增加，若持續給予NAC則能抑制小鼠肺部的細胞浸潤情形、減低血液中O2-的產生和肺沖洗液中Nitrite、IL-6、TNF-α的產生。推測NAC可能是藉由改變血液和肺泡環境中活性氧化物濃度，以及IL-6、TNF-α的釋放，來減低小鼠肺部發炎。

Reactive oxygen species (ROS) play a prominent role in the pathogenesis of various inflammatory airway disorders, including asthma. N-acetylcysteine (NAC), a thiol antioxidants and free radical scavenger, can increase the intracellular glutathione concentration and decrease the NF-kB activity. The objective of my study is to clarify the role of ROS in allergic response in house dust mite Dermatophagoides farinae (Der f)-induced asthma models.
The effects of NAC have been tested in two Der f-induced asthma models: a parental sensitization model with Der f in the prescence of Alum, and an airway sensitization model with repetitive Der f intratracheal challenge. The Der f-induced responses were examined and compared between NAC-treated and non-treated mice, including inflammatory mediator production (ROS, cytokine and NO ), BAL cell infiltration, blood eosinophil count, serum antibody concentration, lung lipid peroxidation and airway hyperresponsiveness.
In the parental sensitization model, NAC could decrease total cell numbers, macrophages infiltration and reduce eosinophil counts in blood. In the single Der f challenge model, NAC could decrease total cell numbers, macrophages and lymphocyte infiltration. It also slightly inhibited nitrite, TNF-α and IL-6 contents in BAL fluid and reduced blood superoxide anion production. In the airway sensitization model, NAC suppressed the influx of total cell numbers, macrophages and TNF-α and IL-6 contents in BAL fluid. My results indicated that NAC could suppress lung inflammation of Der f-sensitized mice, probably via the reduction of blood superoxide anion production and inhibition of cytokine release.

1.告別氣喘與過敏:蔡肇基的免疫力治療 /蔡肇基 時報文化, 2003 [民92]
ISBN 957-13-3900-8
2. Hewitt CRA. Mite allergens: significance of enzymatic activity.Allergy 53(Suppl
48):60-3 (1998)
3. Seiji K., et al. 16:a novel gelsolin-related molecule identified as an allergen from the house dust mite, Dermatophagoides farinae. FEBS Letters 516:234-238 (2002)
4. Shakib F, Schulz O, and Sewell H. A mite subversive: cleavage of CD23 and
CD25 by Der p 1 enhances allergenicity. Immunol Today 19:313-6 (1998)
5. Pamela BD. Intruder in the dust: Why are the dust mite such effective allergens? Am. J Respi Cell Mo Bio 12:367-8 (1995)
6. Yu CK, Shieh CM, Lei HY. Repeated intratracheal inoculation of house dust mite
( Dermatophagoides farinae ) induces pulmonary eosinophilic inflammation and IgE antibody production in mice. J Allergy Clin Immunol 104: 228-36 (1999)
7 .Chen CL, Lee CT, Liu YC, et al. Houst dust mite Dermatophagoides farinae augment proinflammatory mediator productions and accessory function of alveolar macrophages: implications for allergic sensitization and inflammation. The Journal of Immunology 170: 528-536 (2003)
8. Kay AB. Asthma and inflammation. J Allergy Clin Immunol 87:893-910 (1991)
9. Doucet C, Brouty-Boye D, Pottin-Clemenceau C, et al. IL-4 and IL-13 specifically increase adhesion molecule and inflammatory cytokine expression in human lung fibroblasts. Int Immunol 10(10): 1421-1433 (1998)
10.Busse WW, Lemanske RF. Asthma. N Engl J Med 344(5): 350-362 (2001)
11.Shi HZ, Deng JM, Xu Hui, et al. Effect of inhaled interleukin-4 on airway hyperreactivity in asthmatics. Am J Respir Crit Care Med 157 (6): 1818-1821 (1998)
12.Azzawi M, Bradley B, Jeffrey PK, et al. Identification of activated T lymphocytes and eosinophils in bronchial biopsies in stable atopic asthma. Am Rev Respir Dis 142: 1407-1413 (1990)
13.Maestrelli P, Occari P, Turato G, et al. Expression of interleukin (IL)-4 and IL-5 protein in asthma induced by toluene diisocyanate (TDI). Clin Exp Allergy 27(11): 1292-1298 (1997)
14.Coyle AJ, Le Gros G, Bertrand C, et al. Interleukin-4 is required for the induction of lung Th2 mucosal immunity. Am J Respir Cell Mol Biol 13(1): 54-59 (1995)
15.Wills-Karp M, Luyimbazi J, Xu X, et al. Interleukin-13: central mediator of allergic asthma. Science 282: 2258-2261 (1998)
16.Rothenberg ME. Eosinophilia. N Engl J Med 338(22): 1592-1600 (1998)
17.Crapo JD, Barry BE, Gehr P, Bachofen M, and Weibel ER. Cell number and characteristics of the normal human lung. Am Rev Respir Dis 125:332-37 (1982)
18.Thepen T, Kraal G, and Holt PG. The role of alveolar macrophages in regulation of lung inflammation. Annals of New York Academy of Sciences 725: 200-206 (1994)
19.Holt PG. Inhibitory activity of unstimulated alveolar macrophages on T-lymphocyte blastogenic response. Am Rev Respir Dis 118:791-3 (1978)
20. Holt PG, Oliver J, Bilyk N, McMenamin C, McMenamin PG, Kraal G, and Thepen T. Downregulation of the antigen presenting cell function(s) of pulmonary dendritic cell in vivo by resident alveolar macrophages. J Exp Med 177:397-407 (1993)
21.Bousquet J, Jeffery P, Busse W, et al. Asthma: from bronchoconstriction to airways inflammation and remodeling. Am J Respir Crit Care Med 161: 1720-1745 (2000)
22.Rahman I and MacNee W. Role of oxidant/antioxidants in smoking-induced lung disease. Free Radical Biol Med 21: 669-681 (1996)
23.Rahman I and MacNee W. Role of transcription factors in inflammatory lung disease. Thorax 53: 601-612 (1998)
24.Guyton KZ, Liu Y, Gorospe M, Xu Q and Holbrook NJ. Activation of mitogen-activated protein kinase by H2O2: role in cell survival following oxidant injury. J Biol Chem 271: 4138-4142 (1996)
25.Cortijo J, Marti-Cabrera M, de la Asuncion JG, et al. Contraction of human airways by oxidative stress protection by N-acetylcysteine. Free Radical Biol Med 27: 392-400 (1999)
26.Seltzer J, Bigby BG, Stulbarg M, et al. O3-induced change in brochial reactivity to methacholine and airway inflammation in human. J Appl Physiol 60: 1321-1326 (1986)
27.Hulsmann AR, Raatgeep HR, den Hollander JC, et al. Oxidative epithelial damage produces hyperresponsiveness of human peripheral airways. Am J Respir Crit Care Med 149: 519-525 (1994)
28.Krishna MT, Madden J, Teran LM, et al. Effects of 0.2 ppm ozone on biomarkers of inflammation in bronchoalveolar lavage fluid and bronchial mucisa of healthy subjects. Eur Respir J 11: 1294-1300 (1998)
29.Hisada T, Adcock I, I M, Nasuhara Y, Salmon M, Huang TJ, Barnes PJ and Chung KF. Inhibition of ozone-induced lung neutrophilia and nuclear factor-kappa B binding activity by vitamin A in rat. Eur J Pharmacol 14: 63-68 (1999)
30.Samet JM, Hatch GE, Horstman D, Steck-Scott S, Arab L, Bromberg PA, Levine M, Mcdonnell WF and Devlin RB. Effect of antioxidant supplementation on ozone-induced lung injury in human subjects. Am J Respir Crit Care Med 164: 819-825 (2001)
31.Bulger EM, Helton WS, Clinton CM. Enteral vitamin E supplementation inhibits the cytokine response to endotoxin. Arch Surg 132: 1337-1341 (1997)
32.Rahman I, Morrison D, Donaldson K and MacNee W. Systemic oxidative stress in asthma, COPD, and smokers. Am J Respir Crit Care Med 154: 1055-1060 (1996)
33. Rahman I and MacNee W. Oxidative stress and regulation of glutathione in lung inflammation. Eur Respir J 16: 534-554 (2000)
34.Ziment I. Acetylcysteine: a drug with an interesting past and a fascinating future. Respiration 50: 26-30 (1986)
35.Walsh TS and Lee A. N-acetylcysteine administration in the critically ill. Intensive Care Med 25: 432-434 (1999)
36.Victor VM and De la Fuente M. N-acetylcysteine improves in vitro the function of macrophages from mice with endotoxin-induced oxidative stress. Free radic Res
36:33-45 (2002)
37.Whitekus MJ, Li N, Zhang M, Wang M, Horwitz MA, Nelson SK, Horwitz LD, Brechun N, Diaz-Sanchez D, and Nel AE. Thiol antioxidants inhibit the adjuvant effects of aerosolized doesel exhaust particles in a murine model for ovalbumin sensitization. J Immunology 168:2560-2567 (2002)
38.Gillissen A, Nowak D. Characterization of N-acetylcysteine and ambroxol in anti-oxidant therapy. Respir Med. 92: 609-623 (1998)
39.Roy C and Wayne Mitzner. Expression of airway hyperreactivity to acetylcholine as a simple autosomal recessive trait in mice. FASEB J 2: 2605-2608 (1988)
40.Corry DB, Folkesson HG, Warnock ML, et al. Interleukin 4, but not interleukin 5 or eosinophils, is required in a murine model of acute airway hyperreactivity. J Exp Med 183: 109-117 (1996)
41.Robinson D, Hamid Q, Bentley A, Ying S, Kay AB, and Durham SR. Activation of CD4+ T cells, increased Th2-type cytokine mRNA expression, and eosinophil recruitment in bronchoalveolar lavage after allergen inhalation challenge in patients with atopic asthma. J Allergy Clin Immunol 92:313-324 (1993)
42.Serrano-Mollar A, Closa D, Cortijo J, Morcillo EJ, Prats N, Gironella M, Panes J, Rosello-Catafau J, Bulbena O. P-selectin upregulation in bleomycin induced lung injury in rats: effect of N-acetyl-L-cysteine. Thorax 57: 629-634 (2002)
43.Chong IW, Lin SR, Hwang JJ, Huang MS, Wang TH, Hung JY, Paulauskis JD. Expression and regulation of the macrophage inflammatory protein-1 alpha gene by nicotine in rat alveolar macrophages. European Cytokine Network. 13(2): 242-249 (2002)