Guang-Yuh Hwang

Identification and expression of scavenger receptor SR-BI in endothelial cells and smooth muscle cells of rat aorta in vitro and in vivo

In this study, we used immunoelectron microscopy to investigate the subcellular localization of scavenger receptor class B type I (SR-BI) in the arterial walls of rats. The expression of SR-BI in cultured endothelial and smooth muscle cells of rat aorta after exposure to high-density lipoprotein (HDL) was also investigated by immunofluorescence microscopy and immunoblotting analysis. A peptide containing residues 495-509 from mouse SR-BI (mSR-BI) plus an NH2-terminal cysteine was coupled to hemocyanin to generate mSR-BI antiserum in rabbits. Reactivity of antiserum against the synthetic peptides was confirmed with an enzyme-linked immunosorbent assay (ELISA). The results showed that SR-BI was specifically localized on the surface of the endothelial cells and smooth muscle cells. SR-BI was also observed in the cytoplasm of smooth muscle cells. Immunoblotting analysis indicated that SR-BI was expressed in the cell membrane. The levels of SR-BI increased gradually from 1 to 3 h and decreased at 24 and 48 h after cholesterol-loaded cells were incubated in the culture medium containing HDL. We conclude that SR-BI, a functional receptor for HDL, is expressed in the aortic endothelial cells as well as in smooth muscle cells. This receptor also responds to the presence of HDL in the culture medium.

Taiwanofungus, a polypore new genus

Taiwanofungus Sheng H. Wu, Z.H. Yu, Y.C. Dai & C.H. Su is proposed as a new genus of lignicolous polypore, and Ganoderma comphoratum M. Zang & C.H. Su is designated as its generic type. New combinations for two species of Taiwanofungus are presented: T. camphoratus (M. Zang & C.H. Su) Sheng H. Wu, Z.H. Yu, Y.C. Dai & C.H. Su, and T. salmoneus (T.T. Chang & W.N. Chou) Sheng H. Wu, Z.H. Yu, Y.C. Dai & C.H. Su. Taiwanofungus camphoratus is known in Taiwan as “niu-chang-chih”. Taiwanofungus shares many common charaters with Antrodia and Antrodiella. Phylogenetic analysis based on sequence data derived from LSU rDNA indicates that Taiwanofungus camphoratus neither clusters with Antrodia, nor with Antrodiella. Taiwanofungus camphoratus is known only occurring in Taiwan and on trunk of Cinnamomum kanehirai Hay. This fungus is well known by its medicinal uses and high economic value. Taiwanofungus camphoratus was first named Ganoderma comphoratum in 1990. Antrodia cinnamomea T.T. Chang & W.N. Chou was presented for the same species in 1995. Antrodia camphorata (Zang & Su) Sheng H. Wu, Ryvarden & T.T. Chang, new combination proposed in 1997 based on Ganoderma comphoratum, has been widely applied to this fingus.

Overexpression, Purification, and Characterization of the Recombinant Leucine Aminopeptidase II of Bacillus stearothermophilus

For expression of Bacillus stearothermophilus NCIB 8924 leucine aminopeptidase II (LAP II) in Escherichia coli regulated by a T5 promoter, the gene was amplified by polymerase chain reaction and cloned into expression vector pQE-32 to generate pQE-LAPII. The His6-tagged enzyme was overexpressed in IPTG-induced E. coli M15 (pQE-LAPII) as a soluble protein and was purified to homogeneity by nickel-chelate chromatography to a specific activity of 425 U/mg protein with a final yield of 76%. The subunit molecular mass of the purified protein was estimated to be 44.5 kDa by SDS-PAGE. The temperature and pH optima for the purified protein were 60°C and 8.0, respectively. Under optimal condition, the purified enzyme showed a marked preference for Leu-p-nitroanilide, followed by Arg- and Lys-derivatives. The His6-tagged enzyme was stimulated by Co2+ ions, but was strongly inhibited by Cu2+ and Hg2+ and by the chelating agents, DTT and EDTA. The EDTA-treated enzyme could be reactivated with Co2+ ions, indicating that it is a cobalt-dependent exopeptidase. Taking the biochemical characteristics together, we found that the recombinant LAP II exhibits no important differences from those properties described for the native enzyme.

Oxidative stress in nonallergic nasal polyps associated with bronchial hyperresponsiveness

Background:  Nasal polyposis (NP) is a chronic inflammatory disease of upper airway with unknown etiology. NP is frequently associated with asthma; the interaction between these comorbidities remains interesting. Oxidative stress has been implicated in the pathophysiology of NP and asthma. The aim of this study is to investigate the significance of oxidative stress in sinonasal microenvironments by evaluating its association with clinopathological parameters and its impacts on the pathogenesis of bronchial hyperresponsiveness (BHR) in NP.

Sensitization to Per a 2 of the American cockroach correlates with more clinical severity among airway allergic patients in Taiwan.

BACKGROUND In Taiwan, 57.5% of asthmatic patients are allergic to cockroaches, which are a major indoor allergen for immunoglobulin E (IgE)-mediated respiratory diseases. OBJECTIVE To determine whether sensitization to different cockroach allergenic components correlates with different clinical manifestations and severities. METHODS The complementary DNAs (cDNAs) encoding for Per a 1 through 7 and Per a 9 were generated by reverse transcription polymerase chain reaction and cloned into the Escherichia coli expression system. Sixty-four subjects were divided into 3 groups based on the clinical severity of their allergic reaction: those with persistent asthma and rhinitis (AS), those with allergic rhinitis only (AR), and the nonallergic controls (NA). Serum levels of interleukin-8 (IL-8), monocyte chemotactic protein-1 (MCP-1), chemokine (C-C motif) ligand 20 (CCL-20), and granulocyte macrophage colony-stimulating factor (GM-CSF) were measured, and the binding frequencies to each recombinant allergen were examined. RESULTS Serum levels of IL-8, MCP-1, and CCL-20 were significantly higher in the AS group than in the AR and NA groups. The numbers of IgE-binding allergens did not correlate with the clinical severity of airway allergy to cockroaches. However, 81% in the AS group had IgE-binding activity to Per a 2, which was significantly higher than that of the AR group (45%, P < .05). In contrast, 80% of AR patients had IgE-binding activity to Per a 9 compared with only 28.5% of AS patients (P < .01). CONCLUSION Allergens from American cockroaches do not have equal importance in terms of pathogenicity. Sensitization to Per a 2 correlates with more severe airway allergy and elevated proinflammatory chemokines. This may help in selecting target allergens for component resolved diagnosis and immunotherapeutic agents.

Hypersensitivity to Forcipomyia taiwana (biting midge): clinical analysis and identification of major For t 1, For t 2 and For t 3 allergens.

Background:  Forcipomyia taiwana is a tiny, blood‐sucking midge that cause intense pruritis and swelling in sensitive individuals. It is distributed island‐wide in rural Taiwan and Southern China.

Altered Expression Profile of Superoxide Dismutase Isoforms in Nasal Polyps from Nonallergic Patients

Objective/Hypothesis: Nasal polyposis (NP) is a chronic inflammatory disease of the upper respiratory tract. The pathophysiology is unknown but has been shown to be multifactorial. Free radical‐mediated damage has been implicated in the pathogenesis of NP. Superoxide dismutases (SODs) are the first and the most important line of antioxidant enzyme defense against reactive oxygen species. Moreover, isozymes of the SOD family are critical for modulating the activity of nitric oxide, a gaseous free radical that is believed to play roles in the physiology and pathology of respiratory tracts. However, the expression profile of SOD isoforms in NP remains unclear. We aimed to investigate the expression profile of the SOD isoforms in nasal polyps from nonallergic patients.

Effects of Hepatitis B Virus X Protein (HBx) on Cell-Growth Inhibition in a CCL13-HBx Stable Cell Line

Objective: The known function of hepatitis B virus X protein (HBx) is to determine the fate of cells by modulating various signaling pathways. In our previous study, we demonstrated that HBx inhibits tumor formation in nude mice injected with CCL13-HBx stable cell lines; however, the mechanism underlying this inhibition is unclear. Methods: To investigate the possible mechanisms underlying HBx involvement in CCL13-HBx cells, gene profiles were initially analyzed by DNA microarray technology and subsequently confirmed by performing semiquantitative RT-PCR and Western blotting. Furthermore, the phenomenon of cell death via apoptosis was detected via DNA fragmentation, TUNEL staining, caspase-3 activity assay, and propidium iodide (PI) staining. Results: The results indicated that HBx induction downregulated Wnt-3 and β-catenin that are involved in cell proliferation. Moreover, HBx induction repressed cell growth and downregulated the expressions of cyclin D1, CDK4, cyclin E, CDK2, and cyclin B1. Furthermore, HBx induction triggered cell death via apoptosis, as determined by DNA fragmentation, TUNEL staining, caspase-3 activity assay, and PI staining. Conclusion: Most importantly, our results indicated that HBx induction in the CCL13-HBx stable cell line downregulated Wnt-3/β-catenin expression and suppressed cell growth by repressing cell proliferation or triggering cell apoptosis.

Pregnancy-induced Hemophagocytic Lymphohistiocytosis Combined with Autoimmune Hemolytic Anemia

Hemophagocytic lymphohistiocytosis (HLH), presenting with fever, cytopenia, liver dysfunction, hepatosplenomegaly, hypertriglyceridemia, and hyperferritinemia, is associated with various etiologies, including infections, collagen vascular diseases, and malignancies. The present report describes a 28-year-old woman who developed HLH combined with autoimmune hemolytic anemia (AIHA) at 23 weeks of gestation. Without response to corticosteroid, the patient completely recovered from both HLH and AIHA after termination of the pregnancy. Pregnancy-induced immune dysregulation and cytokine overproduction in genetically susceptible women may play critical roles in HLH. The differential diagnosis of pregnant women with fever and cytopenia should include HLH. Pregnancy termination should be considered when pregnancy-induced HLH is refractory to medical treatment.

Identification of Hevamine and Hev b 1 as Major Latex Allergens in Taiwan

Background: Proteins from latex gloves have been documented to trigger occupational latex allergy among health care workers. Allergen characterization of latex glove extract has never been studied in Taiwan. This study aimed to identify allergenic proteins from latex gloves. Methods: Crude extracts of latex gloves were prepared with phosphate-buffered saline and 20 medical workers with a history of latex allergy were enrolled in this study. The specific IgE antibody was determined by the Pharmacia CAP system and in-house enzyme-linked immunoassay and immunoblotting. The target proteins were excised from two-dimensional PAGE and analyzed by electrospray ionization tandem mass spectrometry. Results: Immunoblotting of glove extracts revealed three IgE-binding proteins at a molecular mass of 45, 30 and 14 kDa. Peptide mass fingerprinting revealed that the protein at 45 kDa, which was recognized by 10% (2/20) of atopic sera tested, was an allergenic lipolytic esterase from Hevea brasiliensis (Hev b 13). The 30- and 14-kDa proteins, which were recognized by 55% (11/20) and 85% (17/20) of patients’ sera, were found to be hevamine and rubber elongation factor (Hev b 1), respectively. Conclusions: Our results indicated that hevamine and Hev b 1 are the major allergens from latex gloves in Taiwan, which differs from the reports in Western countries.