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1,106 results on '"Huang, J.‐H."'

201. Functional characterization of hypertrehalosemic hormone receptor in relation to hemolymph trehalose and to oxidative stress in the cockroach Blattella germanica

Author

National Science Council (Taiwan), Consejo Superior de Investigaciones Científicas (España), Ministerio de Ciencia e Innovación (España), Huang. J. H., Bellés, Xavier, Lee, How-Jing, National Science Council (Taiwan), Consejo Superior de Investigaciones Científicas (España), Ministerio de Ciencia e Innovación (España), Huang. J. H., Bellés, Xavier, and Lee, How-Jing

Abstract

Hypertrehalosemic hormone (HTH) is a peptide hormone that belongs to the adipokinetic hormone/red pigment concentrating hormone (AKH/RPCH) family, which exerts pleiotropic actions related to catabolic reaction and stress response. AKH peptides have been demonstrated to participate in stress response including oxidative stress in several insects. In order to study the signaling pathway of HTH involved in anti-oxidative stress, we have characterized a HIH receptor cDNA in Blattella germanica (Blage-HTHR) in structural and in functional terms using RNA interference (RNAi). Blage-HTHR is expressed in various female adult tissues (brain–CC–CA, ventral nerve cord, midgut, fat body, oviduct), but maximal expression is observed in the fat body. RNAi-mediated knockdown of Blage-HTHR expression results in a significantly lower level of hemolymph trehalose, even though HTH is exogenously administered. Paraquat elicits lethal oxidative stress in B. germanica, and co-injection of paraquat and HTH reduces this detrimental effect and extends the median survival time. Interestingly, the “rescue” effect of HTH on mortality caused by paraquat is diminished in specimens with depleted expression of Blage-HTH and Blage-HTHR. Finally, lipid peroxidation in the hemolymph increases 4 h after paraquat treatment, in comparison with control specimens or with HTH-treated specimens. However, lipid peroxidation induced by paraquat was not “rescued” by HTH in Blage-HTH and Blage-HTHR knockdown specimens. Our results demonstrate that HTH acts as a stress hormone mediating anti-oxidative protection in B. germanica, and that its receptor, Blage-HTHR, is essential for this action.

Published
2012

202. Effects of luteolin and quercetin, inhibitors of tyrosine kinase, on cell growth and metastasis-associated properties in A431 cells overexpressing epidermal growth factor receptor

Author

Huang, Y -T, Hwang, J -J, Lee, P -P, Ke, F -C, Huang, J -H, Huang, C -J, Kandaswami, C, Middleton, E, and Lee, M -T

Subjects
Flavonoids, Blotting, Western, DNA Fragmentation, Protein-Tyrosine Kinases, Precipitin Tests, Matrix Metalloproteinases, ErbB Receptors, Papers, Tumor Cells, Cultured, Autoradiography, Humans, Electrophoresis, Polyacrylamide Gel, Quercetin, Enzyme Inhibitors, Neoplasm Metastasis, Phosphorylation, Luteolin, Phosphotyrosine, Cell Division, Densitometry
Abstract

1. Flavonoids display a wide range of pharmacological properties including anti-inflammatory. Anti-mutagenic, anti-carcinogenic and anti-cancer effects. Here, we evaluated the effects of eight flavonoids on the tumour cell proliferation, cellular protein phosphorylation, and matrix metalloproteinase (MMPs) secretion. 2. Of the flavonoids examined, luteolin (Lu) and quercetin (Qu) were the two most potent agents, and significantly inhibited A431 cell proliferation with IC50 values of 19 and 21 micronM, respectively. 3. The epidermal growth factor (EGF) (10 nM) promoted growth of A431 cells (+25+/-4.6%) and mediated epidermal growth factor receptor (EGFR) tyrosine kinase activity and autophosphorylation of EGFR were inhibited by Lu and Qu. At concentration of 20 micronM, both Lu and Qu markedly decreased the levels of phosphorylation of A431 cellular proteins, including EGFR. 4. A431 cells treated with Lu or Qu exhibited protuberant cytoplasmic blebs and progressive shrinkage morphology. Lu and Qu also time-dependently induced the appearance of a ladder pattern of DNA fragmentation, and this effect was abolished by EGF treatment. 5. The addition of EGF only marginally diminished the inhibitory effect of luteolin and quercetin on the growth rate of A431 cells, treatment of cellular proteins with EGF and luteolin or quercetin greatly reduced protein phosphorylation, indicating Lu and Qu may act effectively to inhibit a wide range of protein kinases, including EGFR tyrosine kinase. 6. EGF increased the levels of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9), while Lu and Qu appeared to suppress the secretion of these two MMPs in A431 cells. 7. Examination of the relationship between the chemical structure and inhibitory effects of eight flavonoids reveal that the double bond between C2 and C3 in ring C and the OH groups on C3' and C4' in ring B are critical for the biological activities. 8. This study demonstrates that the inhibitory effects of Lu and Qu, and the stimulatory effects of EGF, on tumour cell proliferation, cellular protein phosphorylation, and MMP secretion may be mediated at least partly through EGFR. This study supports the idea that Lu and Qu may have potential as anti-cancer and anti-metastasis agents.

Published
1999

231. Structural design, process, and reliability of a wafer-level 3D integration scheme with Cu TSVs based on micro-bump/adhesive hybrid wafer bonding

Author

Ko, C. T., primary, Hsiao, Z. C., additional, Chang, Y. J., additional, Chen, P. S., additional, Huang, J. H., additional, Fu, H. C., additional, Huang, Y. J., additional, Chiang, C. W., additional, Lee, C. K., additional, Chang, H. H., additional, Tsai, W. L., additional, Chen, Y. H., additional, Lo, W. C., additional, and Chen, K. N., additional

Published
2012
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