Showing papers by "James L. Kirkland published in 1999"
TL;DR: The quantity of oleate incorporated into TG was found to increase as preadipocytes differentiated into fat cells, and the ratio of unesterified [1-13C]oleate to total stored fatty acids was higher in less differentiated Cells, and declined at later stages of differentiation as cells accumulated fatty acids through de novo synthesis.
Abstract: Oleate is one of the most abundant dietary fatty acids, and much remains to be learned about its metabolism in fat cells. We studied the incorporation of exogenous [1-13C]-oleate into triglycerides (TG) in differentiating 3T3L1 preadipocytes using 13C NMR spectroscopy. The quantity of oleate incorporated into TG was found to increase as preadipocytes differentiated into fat cells. The ratio of unesterified [1-13C]oleate to total stored fatty acids was higher in less differentiated cells, and declined at later stages of differentiation as cells accumulated fatty acids through de novo synthesis. When added as the only exogenous fatty acid, oleate was largely esterified at the sn-2 position. When equimolar unlabeled linoleate was co-provided at the same time, the ratio of [1-13C]oleate esterified at the sn-1,3 position increased, implying competition between linoleate and oleate for esterification, especially at the sn-2 position. When cells pre-enriched with [1-13C]oleate (esterified to TG) were treated with isoproterenol, a lipolytic agent, most of the [1-13C]oleate was still found in TG, despite a high rate of lipolysis determined by measuring glycerol release. This implies extensive re-esterification of the oleate released by lipolysis.
10 citations
Patent•
08 Jun 1999
TL;DR: In this article, the authors provide methods for screening potential therapeutic compounds useful in the treatment of metabolic diseases, e.g., diabetes. In particular, the invention provides methods of identifying compounds which modulate the activity of a mitochondrial anion carrier (MAC) which include contacting assay vesicles of the present invention with test compounds, determining the ability of the test compounds to modulating the transport of a MAC substrate across the lipid bilayer of the vesicle, and identifying the test compound as a modulator of MAC activity.
Abstract: The invention provides methods for screening potential therapeutic compounds useful in the treatment of metabolic diseases, e.g., diabetes. In particular, the invention provides methods of identifying compounds which modulate the activity of a mitochondrial anion carrier (MAC) which include contacting assay vesicles of the present invention with test compounds, determining the ability of the test compounds to modulate the transport of a MAC substrate across the lipid bilayer of the assay vesicle, and identifying the test compound as a modulator of MAC activity. The assay vesicles of the present invention include, for example, one two or three MACs, wherein the activity of at least one MAC is coupled to a detectable readout (e.g., a change in membrane potential and/or pH). The invention also provides novel assay vesicles as well as novel methods of preparing assay vesicles.
9 citations
TL;DR: Age-Related Adipose Tissue mRNA Expression ofADDlISREBPl, PPARy, Lipoprotein Lipase, and GLUT4 Glucose Transporter in Rhesus Monkeys shows that aging is associated with declines in expression of certain transcription factors that regulate preadipocyte differentiation and fat cell function in whole fat tissue from rhesus monkeys.
3 citations