Wing-tai Cheung

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The peroxisome proliferator-activated receptor alpha (PPARalpha) has been implicated as a key control of fatty acid catabolism during the cellular fasting. However, little is known regarding changes of individual fatty acids in hepatic triacylglycerol (TG) and phospholipid (PL) as a result of starvation. In the present work, the effects of 72 h fasting on(More)
In the present study, a phage-displayed random peptide library was used to identify surrogate peptide ligands for orphan GPCR mas. Sequence analysis of the isolated phage clones indicated a selective enrichment of some peptide sequences. Moreover, multiple alignments of the isolated phage clones gave two conserved peptide motifs from which we synthesized(More)
Previous study using Cyp2e1-null mice showed that Cyp2e1 is required in CCl(4)-induced liver injury at 24h, what remains unclear are the temporal changes in liver damage and the spectrum of genes involved in this process. We investigated the time-dependent liver changes that occurred at morphological, histopathological, biochemical and molecular levels in(More)
Bradykinin is a potent vasoactive nonapeptide. It elicits a rise in cytosolic Ca(2+) (Ca(2+))(i) in endothelial cells, resulting in Ca(2+)-dependent synthesis and release of endothelial vasodilators. In the present study, we investigated the mechanism of bradykinin-induced Ca(2+) influx in primary cultured rat aortic endothelial cells and in a mouse heart(More)
The peroxisome proliferator-activated receptor alpha (PPARalpha) has been known to play a pivotal role in maintaining the energy balance during fasting; however, the battery of PPARalpha target genes involved in this metabolic response is still not fully characterized. Here, we report the identification and characterization of Ppsig (for PPARalpha-regulated(More)
Despite heterologous expression of epitope-tagged GPCR is widely adopted for functional characterization, there is lacking of systematic analysis of the impact of expression host and epitope tag on GPCR expression. Angiotensin type II (AT2) receptor displays agonist-dependent and -independent activities, coupling to a spectrum of signaling molecules.(More)
The functional activity of G protein-coupled receptors can be modified by their ability to form oligomeric complexes with G protein-coupled receptors from other receptor families. Emerging evidence suggests that the appetite-regulating hormone ghrelin is a directly acting vasodilator peptide with anti-inflammatory activity, therefore, we have examined the(More)
Millions of candidate clones are commonly obtained following rounds of phage-displayed antibody library panning, and expression of those selected single-chain variable fragment (scFv) is required for secondary functional screening to identify positive clones. Large scale functional screening is often hampered by the time-consuming and labor-intensive(More)
In conclusion, we have applied the fluorescent differential method and the PPAR alpha-null mouse model for the rapid isolation of expression tags of PPAR alpha target genes that are involved in the action of peroxisome proliferators and in the regulation of lipid homeostasis under energy deprivation. Identification of a wide spectrum of PPAR alpha target(More)
DHFR-deficient Chinese hamster ovary (CHO DHFR(-)) cells are the most popular mammalian expression system for inducible amplification of transgene. In order to obtain more stable transfected CHO DHFR(-) cell clones, transfection efficiency of electroporation under different conditions were systemically investigated using plasmid pSV-beta-Gal as reporter(More)