Taiyoun Rhim

ADAM33 polymorphism : association with bronchial hyper-responsiveness in Korean asthmatics

Background A disintegrin and metalloprotease 33 (ADAM33) is expressed in the lung by fibroblasts and bronchial smooth muscle cells. Given its structure and cellular provenance, ADAM33 may be associated with airway remodelling and bronchial hyper‐responsiveness. Single nucleotide polymorphisms (SNPs) and haplotypes of the ADAM33 gene have previously been associated with asthma susceptibility in the Caucasian population.

Preparation of budesonide-loaded porous PLGA microparticles and their therapeutic efficacy in a murine asthma model

Inhaling corticosteroids, such as budesonide (BD), is the most common treatment for asthma. However, frequent steroid administration is associated with many side effects. We hypothesized that porous microparticles containing BD could provide an effective treatment method for asthma, as the sustained delivery of corticosteroid and a reduced number of doses could be achieved using porous polymeric microparticles. Porous microparticles were prepared from poly(lactic-co-glycolic acid) (PLGA) by a water-in-oil-in-water double emulsion method with ammonium bicarbonate as the porogen. Varying the porogen concentration controlled the morphology, particle size, and pore size of the PLGA microparticles, with particle size and pore size increasing as the porogen concentration increased. The BD loading efficiency in the porous PLGA microparticles was about 60%, and BD was released from the porous microparticles in a sustained manner for 24h in vitro. Lung uptake efficiency of the porous PLGA microparticles in mice was significantly higher than that of non-porous PLGA microparticles. Budesonide-loaded porous PLGA microparticles were delivered to asthmatic mice, and the numbers of inflammatory cells in bronchoalveolar lavage (BAL) fluid and tissue sections were significantly reduced when the drug was administrated every 3days. We also found significantly reduced bronchial hyperresponsiveness of asthmatic mice after treatment with budesonide-loaded porous PLGA microparticles. This approach to controlling the porous structure of polymeric microparticles, as well as the release behavior of drugs from the microparticles, could have useful applications in the pulmonary delivery of many therapeutic drugs.

Association of angiotensin I‐converting enzyme gene polymorphisms with aspirin intolerance in asthmatics

Background Aspirin‐intolerant asthma (AIA) refers to the development of bronchoconstriction in asthmatic individuals following the ingestion of aspirin or other non‐steroidal anti‐inflammatory drugs (NSAIDs). Angiotensin I‐converting enzyme (ACE), a membrane‐bound peptidase present in the lung, plays a pivotal role in the metabolism of the endogenous peptides involved in the pathogenesis of asthma.

Interleukin 3 (IL3) polymorphisms associated with decreased risk of asthma and atopy.

AbstractCytokines, having central functions in immunological and inflammatory process, are always expected to play important roles in the pathogenesis of various diseases, such as asthma. Genetic polymorphisms of those cytokine and cytokine receptor genes are the focus of genetic association studies. In an effort to identify gene(s) whose variant(s) are involved in the development of asthma, we examined the genetic effects of 19 single nucleotide polymorphisms in eight cytokine and cytokine receptor genes, including IL1A, IL1B, IL2, IL3, IL4, IL8, IL10, and IL5RA, on asthma and atopy. Nineteen single nucleotide polymorphisms in eight cytokine and cytokine receptor genes were genotyped using the single-base extension method in a Korean asthma cohort (n=723). Logistic regression and multiple regressions were used for statistical analyses controlling for smoking, age, and gender as covariables. Genetic association analysis of polymorphisms revealed that one exonic (exon 1), IL3+79T>C (Ser27Pro), showed significant association with the risk of asthma and atopy. The Pro allele had shown dominant and protective effects on development of asthma in nonatopic subjects (P=0.002) and also showed significant association with the risk of atopy in normal control subjects (P=0.007). This information about the genetic association of important genes with asthma might provide valuable insights into strategies for the pathogenesis of asthma and atopy.

Titanium dioxide particle – induced goblet cell hyperplasia : association with mast cells and IL-13

BackgroundInhalation of particles aggravates respiratory symptoms including mucus hypersecretion in patients with chronic airway disease and induces goblet cell hyperplasia (GCH) in experimental animal models. However, the underlying mechanisms remain poorly understood.MethodsTo understand this, the numbers of goblet cells, Muc5ac (+) expressing epithelial cells and IL-13 expressing mast cells were measured in the trachea of sham or TiO2 particles – treated rats using periodic acid-Schiff, toluidine blue and immunohistochemical staining. RT-PCR for Muc-1, 2 and 5ac gene transcripts was done using RNA extracted from the trachea. Differential cell count and IL-13 levels were measured in bronchoalveolar lavage (BAL) fluid. In pretreatment groups, cyclophosphamide (CPA) or dexamethasone (DEX) was given before instillation of TiO2. TiO2 treatment markedly increased Muc5ac mRNA expression, and Muc5ac (+) or PAS (+) epithelial cells 48 h following treatment.ResultsThe concentration of IL-13 in BAL fluids was higher in TiO2 treated – rats when compared to those in sham rats (p < 0.05). Pretreatment with cyclophosphamide (CPA) decreased the number of neutrophils and eosinophils in BAL fluid of TiO2 treated – rats (p < 0.05), but affected neither the percentage of PAS (+) cells, nor IL-13 levels in the BAL fluids (p > 0.05). In contrast, pretreatment with dexamethasone (DEX) diminished the percentage of PAS (+) cells and the levels of IL-13 (p < 0.05). TiO2 treatment increased the IL-13 (+) mast cells (p < 0.05) in the trachea, which was suppressed by DEX (p < 0.05), but not by CPA pretreatment (p > 0.05). In addition there were significant correlations of IL-13 (+) rate of mast cells in the trachea with IL-13 concentration in BAL fluid (p < 0.01) and with the percentage of Muc5ac (+) cells in the sham and TiO2 treated rats (p < 0.05).ConclusionIn conclusion, TiO2 instillation induces GCH and Muc5ac expression, and this process may be associated with increased production of IL-13 by mast cells.

T cell-specific siRNA delivery using antibody-conjugated chitosan nanoparticles.

The intracellular delivery of small interfering RNA (siRNA) plays a key role in RNA interference (RNAi) and provides an emerging technique to treat various diseases, including infectious diseases. Chitosan has frequently been used in gene delivery applications, including siRNA delivery. However, studies regarding the modification of chitosan with antibodies specifically targeting T cells are lacking. We hypothesized that chitosan nanoparticles modified with T cell-specific antibodies would be useful for delivering siRNA to T cells. CD7-specific single-chain antibody (scFvCD7) was chemically conjugated to chitosan by carbodiimide chemistry, and nanoparticles were prepared by a complex coacervation method in the presence of siRNA. The mean diameter and zeta potential of the scFvCD7-chitosan/siRNA nanoparticles were approximately 320 nm and +17 mV, respectively, and were not significantly influenced by the coupling of antibody to chitosan. The cellular association of antibody-conjugated nanoparticles to CD4+ T cell lines as well as gene silencing efficiency in the cells was significantly improved compared to nonmodified chitosan nanoparticles. This approach to introducing T cell-specific antibody to chitosan nanoparticles may find useful applications for the treatment of various infectious diseases.

Association of IL-17RB Gene Polymorphism With Asthma

BACKGROUND Interleukin (IL)-17E is a member of the IL-17 family, which induces IL-4, IL-5, IL-13, and eotaxin in experimental animals via IL-17 receptor B (IL-17RB). The activation of IL-17RB amplifies allergic-type inflammatory responses by inducing Jun kinase (or JNK), p38 mitogen-activated protein kinase (or MAPK), and nuclear factor-kappaB. OBJECTIVES We examined the association of polymorphisms in the IL-17RB gene with asthma susceptibility and investigated the effects of those polymorphisms on the transcription of various IL-17RB isoforms. METHODS In total, 954 asthmatic patients or 265 healthy control subjects were screened for polymorphisms in IL-17RB by single-base extension. The messenger RNA expression IL-17RB in B-cell lines derived from patients was also measured by reverse transcription-polymerase chain reaction. RESULTS Direct sequencing of 24 unrelated Korean DNA samples revealed 18 genetic variants, including four insertion/deletions and 14 single-nucleotide polymorphisms (SNPs). Six of the SNPs (-1465G>A, +5661G>A, +6297T>C [Y123Y], +13797C>T, +18661C>T, and +18965G>A) were used to screen a larger group of subjects. Intronic polymorphism +5661G>A was significantly associated with the development of asthma (p = 0.001); moreover, a minor allele of IL-17RB +5661G>A appeared at a lower frequency in the asthmatic patients than in the healthy control subjects (0.13 vs 0.19, respectively). The IL-17RB messenger RNA expression in B cells homozygous for IL-17RB+ 5661GG was significantly higher than that in B cells homozygous for IL-17RB+5661AA (p = 0.002). CONCLUSIONS A rare allele of IL-17RB +5661G>A may have a protective role against the development of asthma via regulation at the level of transcription. The SNPs identified in this study may be used to develop markers to assess the risk of asthma.

Proteomic Identification of Macrophage Migration-inhibitory Factor upon Exposure to TiO2 Particles

Inhalation of particulate matter aggravates respiratory symptoms in patients with chronic airway diseases, but the mechanisms underlying this response remain poorly understood. We used a proteomics approach to examine this phenomenon. Treatment of epithelial cells with BSA-coated titanium dioxide (TiO2) particles altered 20 protein spots on the two-dimensional gel, and these were then analyzed by nano-LC-MS/MS. These proteins included defense-related, cell-activating, and cytoskeletal proteins implicated in the response to oxidative stress. The proteins were classified into four groups according to the time course of their expression patterns. For validation, RT-PCR was performed on extracts of in vitro TiO2-treated cells, and lung issues from TiO2-treated rats were analyzed by immunohistochemical staining and enzyme immunoassay. TiO2 treatment was found to increase the amount of mRNA for macrophage migration-inhibitory factor (MIF). MIF was expressed primarily in epithelium and was elevated in lung tissues and bronchoalveolar lavage fluids of TiO2-treated rats as compared with sham-treated rats. Carbon black and diesel exhaust particles also induced expression of MIF protein in the epithelial cells.

Preparation and characterization of nonaarginine-modified chitosan nanoparticles for siRNA delivery

Chitosan-based nanoparticles have been widely used as a carrier for gene delivery due to their low toxicity and the positively charged amino groups in chitosan. In this study, we hypothesized that introduction of nonaarginine to chitosan could improve its ability to form a complex with siRNA, as well as enhance the cellular uptake and transfection efficiency of chitosan-based nanoparticles. To this end, a peptide with nine repeating arginine residues was chemically coupled to the chitosan backbone, and various characteristics of nonaarginine-chitosan/siRNA nanoparticles were investigated. The mean diameter and zeta potential of the nonaarginine-chitosan/siRNA nanoparticles were dependent on the amount of nonaarginine conjugated to chitosan. Nonaarginine-modified chitosan/siRNA nanoparticles demonstrated enhanced cellular association and transfection efficiency in vitro, while maintaining a low level of cytotoxicity. In conclusion, nonaarginine-modified chitosan should be considered a potential carrier for various gene delivery applications.

Therapeutic Use of Stem Cell Transplantation for Cell Replacement or Cytoprotective Effect of Microvesicle Released from Mesenchymal Stem Cell

Idiopathic pulmonary fibrosis (IPF) is the most common and severe type of idiopathic interstitial pneumonias (IIP), and which is currently no method was developed to restore normal structure and function. There are several reports on therapeutic effects of adult stem cell transplantations in animal models of pulmonary fibrosis. However, little is known about how mesenchymal stem cell (MSC) can repair the IPF. In this study, we try to provide the evidence to show that transplanted mesenchymal stem cells directly replace fibrosis with normal lung cells using IPF model mice. As results, transplanted MSC successfully integrated and differentiated into type II lung cell which express surfactant protein. In the other hand, we examine the therapeutic effects of microvesicle treatment, which were released from mesenchymal stem cells. Though the therapeutic effects of MV treatment is less than that of MSC treatment, MV treat-ment meaningfully reduced the symptom of IPF, such as collagen deposition and inflammation. These data suggest that stem cell transplantation may be an effective strategy for the treatment of pulmonary fibrosis via replacement and cytoprotective effect of microvesicle released from MSCs.