| Summary: | 碩士 === 國立陽明大學 === 生物化學研究所 === 91 === Resistin and adiponectin are two hormones which were discovered recently. They are secreted by adipose tissue instead of traditional endocrine organs. Adipose tissue is not simply a tissue of excess energy storage, but also secrets a variety of proteins into circulating blood that influence systemics metabolism. From the aspect of its secreted protein that potentially alter the metabolic states of individuals, adipose tissue turns out to be acting as endocrine and secretory organ. Proteins secreted by adipose tissue are collectively known as adipocytokines or adipokines. Up to date, at least 14 proteins have been identified. Some are secreted specifically by adipocytes, while others might also be released from other tissues. The functions of some of these adipokines might be involved in the regulation of energy balance, and the others are involved in immune response, according to previous reports.
In this thesis, the changes in resistin and adiponectin gene expression patterns in 3T3-L1 adipocytes in response to substances mimicking insulin resistance were analyzed and also the secreted proteins profiles was characterized by utilizing proteomics. Pretreatments of those substances in serum-free medium for 8h have shown that resistin mRNA is down-regulated by 10 nM endothelin-1 and 1μM isoproterenol. The amount of adiponectin mRNA was decreased by 50 ng/ ml TNF-α. While in the other experiments instead of KRH buffer has shown that 30 mM glucose has more inhibition effect than the experiment in DMEM medium.
Pretreatments of various fatty acids for 4d have shown that resistin mRNA is down-regulated by oleic acid and linoleic acid. Linolenic acid and arachidonic acid have similar results. The results of adiponectin mRNA expression are similar to resistin except arachidonic acid. The effect of oleic acid on two proteins is almost the same that up-regulate gene expression at 8h. Thapsigargin has stronger inhibition effect than EGTA in two proteins and more early.
High insulin might inhibit total proteins secretion as showed by 2-D electrophoresis and sliver staining. The spots of interest were analyzed by proteomics but the results were opaque.
In the summary, the effects of substances mimicking insulin resistance on the expression of resistin and adiponectin mRNA are similar.
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