BACKGROUND/AIMS: Diesel exhaust particles (DEPs) lead to elevation of reactive oxygen species, which can activate the nucleotide-binding oligomerization domain-like receptor (NLR) family members containing the pyrin domain 3 (NLRP3)-inf lammasome. In this study, we elucidated whether NLRP3 -inf lammasome is activated by DEPs and whether antioxidants (N-acetylcysteine [NAC]) could inhibit such activation. METHODS: RAW 264.7 cells and ex vivo lung tissues explants obtained from elastase-induced emphysema animal models were stimulated with cigarette smoking extract (CSE), DEPs, and lipopolysaccharide, and levels of interleukin-1β (IL-1β), caspase-1 and nucleotide-binding oligomerization domain-like receptor (NLR) family members containing the pyrin domain (NLRP3)-inflammasome were assessed by Western blotting and immunohistochemistry. RESULTS: NAC and caspase-1 inhibitor suppressed CSE- and DEP-induced secretion of IL-1β in RAW 264.7 cells. The expression levels of the NLRP3-inflammasome and caspase-1 were upregulated in RAW 264.7 cells by stimulation with CSE and DEPs and were inhibited by NAC. CSE and DEPs increased the secretion of IL-1β in lung tissues from both the normal and elastase-induced emphysema groups. The secretion of IL-1β by CSE and DEPs was increased in the elastin-induced emphysema group more than that in the normal group (CSE: 309 ± 19 pg/mL vs. 151 ± 13 pg/mL, respectively, p < 0.05; DEP: 350 ± 24 pg/mL vs. 281 ± 15 pg/mL, respectively, p < 0.05). NAC inhibited CSE- and DEP-induced IL-1β secretion in both the normal and elastase-induced emphysema groups. NLRP3-inflammasome expression as determined by immunohistochemistry was increased by CSE and DEPs in both the normal and elastin-induced emphysema groups, and was suppressed by NAC. CONCLUSIONS: The NLRP3-inf lammasome is activated by DEPs in ex vivo tissue explants from elastase-induced emphysema animal model, and this activation is inhibited by NAC.
Antioxidants ; Blotting, Western ; Emphysema* ; Humans ; Immunohistochemistry ; Lung* ; Models, Animal ; Pancreatic Elastase ; Pulmonary Disease, Chronic Obstructive ; RAW 264.7 Cells* ; Reactive Oxygen Species ; Smoking ; Vehicle Emissions*

It has been well known that mesalazine can cause the interstitial lung disease, such as Bronchiolitis obliterans with organizing pneumonia (BOOP), Non-Specific Interstitial Pneumonia (NSIP), or eosinophilic pneumonia. 5-Aminosalicylic acid (5-ASA), mesalazine, and sulfasalazine are important drugs for treating inflammatory bowel disease. Topical products of these limited systemic absorption and have less frequent side effects, therefore suppository form of these drugs have been used more than systemic drug. Most cases of measalzine-induced lung toxicity develop from systemic use of the drug. A 30-year-old woman had an interstitial lung disease after using mesalazine suppository because of ulcerative colitis. The lung biopsy demonstrated eosinophilic pneumonia combined with BOOP. She was recovered after stopping of mesalazine suppository and treatment with systemic steroid.
Absorption, Physiological ; Adult ; Biopsy ; Bronchiolitis Obliterans ; Colitis, Ulcerative ; Cryptogenic Organizing Pneumonia ; Eosinophils ; Female ; Humans ; Inflammatory Bowel Diseases ; Lung ; Lung Diseases, Interstitial ; Mesalamine ; Pneumonia ; Pulmonary Eosinophilia ; Sulfasalazine

Pruritus (itching) is classically defined as an unpleasant cutaneous sensation that leads to scratching behavior. Although the scientific criteria of classification for pruritic diseases are not clear, it can be divided as acute or chronic by duration of symptoms. In this study, we investigated whether skin injury caused by chemical (contact hypersensitivity, CHS) or physical (skin-scratching stimulation, SSS) stimuli causes initial pruritus and analyzed gene expression profiles systemically to determine how changes in skin gene expression in the affected area are related to itching. In both CHS and SSS, we ranked the Gene Ontology Biological Process terms that are generally associated with changes. The factors associated with upregulation were keratinization, inflammatory response and neutrophil chemotaxis. The Kyoto Encyclopedia of Genes and Genomes pathway shows the difference of immune system, cell growth and death, signaling molecules and interactions, and signal transduction pathways. Il1a , Il1b and Il22 were upregulated in the CHS, and Tnf, Tnfrsf1b, Il1b, Il1r1 and Il6 were upregulated in the SSS. Trpc1 channel genes were observed in representative itching-related candidate genes. By comparing and analyzing RNA-sequencing data obtained from the skin tissue of each animal model in these characteristic stages, it is possible to find useful diagnostic markers for the treatment of itching, to diagnose itching causes and to apply customized treatment.
Animals ; Biological Processes ; Chemotaxis ; Classification ; Cytokines ; Dermatitis, Contact* ; Gene Expression ; Gene Ontology ; Genome ; Hypersensitivity ; Immune System ; Interleukin-6 ; Mice* ; Models, Animal ; Neutrophils ; Pruritus* ; RNA* ; Sensation ; Sequence Analysis, RNA* ; Signal Transduction ; Skin* ; Transcriptome ; Transient Receptor Potential Channels ; Up-Regulation ; Wound Healing