The Phosphodiesterase 4 Inhibitor Roflumilast Protects against Cigarette Smoke Extract-Induced Mitophagy-Dependent Cell Death in Epithelial Cells / 결핵및호흡기질환

BACKGROUND: Recent studies show that mitophagy, the autophagy-dependent turnover of mitochondria, mediates pulmonary epithelial cell death in response to cigarette smoke extract (CSE) exposure and contributes to the development of emphysema in vivo during chronic cigarette smoke (CS) exposure, although the underlying mechanisms remain unclear. METHODS: In this study, we investigated the role of mitophagy in the regulation of CSE-exposed lung bronchial epithelial cell (Beas-2B) death. We also investigated the role of a phosphodiesterase 4 inhibitor, roflumilast, in CSE-induced mitophagy-dependent cell death. RESULTS: Our results demonstrated that CSE induces mitophagy in Beas-2B cells through mitochondrial dysfunction and increased the expression levels of the mitophagy regulator protein, PTEN-induced putative kinase-1 (PINK1), and the mitochondrial fission protein, dynamin-1-like protein (DRP1). CSE-induced epithelial cell death was significantly increased in Beas-2B cells exposed to CSE but was decreased by small interfering RNA-dependent knockdown of DRP1. Treatment with roflumilast in Beas-2B cells inhibited CSE-induced mitochondrial dysfunction and mitophagy by inhibiting the expression of phospho-DRP1 and -PINK1. Roflumilast protected against cell death and increased cell viability, as determined by the lactate dehydrogenase release test and the MTT assay, respectively, in Beas-2B cells exposed to CSE. CONCLUSION: These findings suggest that roflumilast plays a protective role in CS-induced mitophagy-dependent cell death.

Anaphylaxis after consumption of abalone

Abalone is popular seafood in Asia; however, allergy to abalone was rarely reported. We report a case of anaphylaxis after consumption of abalone. A 24-year-old female visited an Emergency Department, complaining of cough, dyspnea, rhinorrhea, generalized urticaria, facial edema, and wheezing that had developed 1 hour after consumption of abalone. She was discharged when her symptoms subsided after antihistamine and dexamethasone were given. One month later, she was referred to our outpatient clinic. We performed skin prick tests, measurement of serum specific IgE antibody level, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) with IgE immunoblotting. Both skin prick and specific IgE antibody tests were positive for abalone crude extract. In SDS-PAGE with IgE immunoblotting, we identified possible antigens sized 55, 100, and 25 kDa, respectively. This is the first case of abalone-induced anaphylaxis in Korea.

Taxonomy of Ganoderma lucidum from Korea Based on rDNA and Partial beta-Tubulin Gene Sequence Analysis

In the present study, a phylogenetic analysis was undertaken based on the internal transcribed spacer (ITS) rDNA and partial beta-tubulin gene sequence of the Ganoderma species. The size of the ITS rDNA regions from different Ganoderma species varied from 625 to 673 bp, and those of the partial beta-tubulin gene sequence were 419 bp. Based on the results, a phylogenetic tree was prepared which revealed that Korean Ganoderma lucidum strains belong in a single group along with a G. lucidum strain from Bangladesh.

Effect of Casing Layer on Growth Promotion of the Edible Mushroom Pleurotus ostreatus

Various bacteria were isolated from the casing layer soil of the culture bed of P. ostreatus and their role in fruiting body induction of the edible mushroom, P. ostreatus, was investigated. Analysis of the bacterial community isolated from the casing layer soil revealed that the composition of genera and number of cultivable bacteria were different for each sterilizing treatment. Bordetella was predominant in the bulk soil whereas Flavobacterium was predominant after sterilization of the casing layer soil. Fluorescent Pseudomonas was predominant in the non-sterilized casing layer soil. Total number of the bacterial genera in the casing layer soil was higher than that in the bulk soil. In particular, an increase in the fluorescent Pseudomonas population was observed in the non-sterilized casing layer accompanied by induction of fruiting body and enhanced mushroom production yield. The results suggested that specific bacterial populations in the casing layer play an important role in the formation of primodia and the development of basidiome in P. ostreatus.