Differences in transport of fatty acids and expression of fatty acid transporting proteins in adipose tissue of obese black and white women

Bower, Joseph F.; Davis, Julianne M.; Hao, Enhui; Barakat, Hisham A.

doi:10.1152/ajpendo.00194.2005

Cited by 31 publications

(25 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…γ1 and γ2, PPARγ mRNA levels were found to be similar in subcutaneous and omental adipocytes, in line with results obtained in both whole fat tissue specimens and isolated adipocytes in this study and elsewhere [26][27][28]. This finding is apparently in contrast with the reportedly higher levels of PPARγ found in subcutaneous compared with visceral adipocytes differentiated in vitro in the study by Tchkonia et al [16].…”

Section: Discussionsupporting

confidence: 92%

Fat depot-related differences in gene expression, adiponectin secretion, and insulin action and signalling in human adipocytes differentiated in vitro from precursor stromal cells

et al. 2007

View full text Add to dashboard Cite

Aim/hypothesis The distinct metabolic properties of visceral and subcutaneous adipocytes may be due to inherent characteristics of the cells that are resident in each fat depot. To test this hypothesis, human adipocytes were differentiated in vitro from precursor stromal cells obtained from visceral and subcutaneous fat depots and analysed for genetic, biochemical and metabolic endpoints. Methods Stromal cells were isolated from adipose tissue depots of nondiabetic individuals. mRNA levels of adipocytespecific proteins were determined by real-time RT-PCR.Insulin signalling was evaluated by immunoblotting with specific antibodies. Glucose transport was measured by a 2-deoxy-glucose uptake assay. Adiponectin secretion in the adipocyte-conditioned medium was determined by a specific RIA. Results With cell differentiation, mRNA levels of PPARG, C/EBPα (also known as CEBPA), AP2 (also known as GTF3A), GLUT4 (also known as SLC2A4) were markedly upregulated, whereas GLUT1 (also known as SLC2A1) mRNA did not change. However, expression of C/EBPα, AP2 and adiponectin was higher in subcutaneous than in visceral adipocytes. By contrast, adiponectin was secreted at threefold higher rates by visceral than by subcutaneous adipocytes while visceral adipocytes also showed two-to threefold higher insulin-stimulated glucose uptake. Insulininduced phosphorylation of the insulin receptor, IRS proteins, Akt and extracellular signal-regulated kinase-1/2 was more rapid and tended to decrease at earlier time-points in visceral than in subcutaneous adipocytes. Conclusions/interpretation Subcutaneous and visceral adipocytes, also when differentiated in vitro from precursor stromal cells, retain differences in gene expression, adiponectin secretion, and insulin action and signalling. Thus, the precursor cells that reside in the visceral and subcutaneous fat depots may already possess inherent and specific metabolic characteristics that will be expressed upon completion of the differentiation programme.

show abstract

Section: Discussionsupporting

confidence: 92%

Fat depot-related differences in gene expression, adiponectin secretion, and insulin action and signalling in human adipocytes differentiated in vitro from precursor stromal cells

et al. 2007

View full text Add to dashboard Cite

show abstract

“…Bower et al (11) investigated groups of African-American and Caucasian women, describing that an increase of FATP4 mRNA and protein levels in adipocytes of obese subjects correlates with a higher LCFA uptake rate into this cell type. A separate investigation by Gertow and colleagues (29) was designed to distinguish between influences of genetic and nongenetic parameters on FATP4 gene expression in subcutaneous adipose tissue.…”

Section: Discussionmentioning

confidence: 99%

Protein-Mediated Fatty Acid Uptake: Novel Insights from In Vivo Models

Doege¹,

2006

View full text Add to dashboard Cite

Long-chain fatty acids (LCFAs) are vital components of our diet and contribute to a plethora of processes including metabolic energy generation and storage, plasma membrane synthesis, and protein anchoring. In addition, LCFAs have hormone-like properties since they can profoundly affect gene expression via nuclear receptors such as HNF4 and the PPAR family (reviewed in Ref. 45), trigger insulin release through activation of the G-protein-coupled receptor (GPCR) GPR40 by ␤-cells (89), affect the innate immune response by modulating toll-like receptor (TLR) signaling in a number of cell types (reviewed in Ref. 53), and suppress food intake by inhibiting the release of neuropeptide Y (NPY) and Agouti-related protein (AgRP) in a subpopulation of hypothalamic neurons (reviewed in Refs. 51, 78). Because of the physiological significance of LCFAs, chronic imbalances in lipid fluxes and metabolism often cause a variety of (metabolic) abnormalities and pathologies, including hyperlipidemia, obesity, Type 2 diabetes mellitus, nonalcoholic fatty liver disease, heart disease, and cancer (16,37,50,54,56,57,64,73).Although in some tissues and cell types LCFAs can signal through GPCRs or TLRs (53, 89), they typically have to first cross the plasma membrane to elicit their effects. In general, the uptake of fatty acids from the circulation into cells include the sequence of 1) localized generation of free fatty acids through hydrolysis of triglyceride (TG)-rich lipoproteins by lipases inside the endothelial lumen and binding of fatty acids to albumin, 2) fatty acid dissociation from albumin followed by binding to plasma membrane proteins or integration into the lipid bilayer, 3) their transport across the plasma membranes, and 4) their intracellular association with fatty acid binding and acyl-CoA binding proteins (FABPs and ACBPs, respectively) (1, 33, 91), as illustrated in FIGURE 1A. The mechanism by which fatty acids cross the plasma membrane has been debated for several years. Because fatty acids are predominantly lipophilic, it was initially proposed that they traverse the lipid bilayer by diffusion (passive flip-flop) without the involvement of protein mediators (35,68). However, many organs and cell types display a rapid, saturable, substrate-specific, and hormonally regulated LCFA uptake mechanism indicative of protein-mediated processes (8,10,83). Although the occurrence of both LCFA uptake processes are now widely accepted, during the past years considerable data have demonstrated that protein-mediated transport accounts for the majority of fatty acid uptake by tissues with high LCFA metabolism and storage such as skeletal muscle (99), adipose tissue (75), liver (22,24,26,82,93,95), and heart (81, 94). Particularly, at physiological concentrations and serum-to-albumin ratios, the concentration of unbound fatty acids is low (7.5 nM) and >90% of LCFA uptake occurs via the protein-mediated pathway (71). The crucial role of proteins for efficient LCFA uptake has been underscored by a number of knockout (KO) model systems...

show abstract

“…With the FATP4 localization in the ER and MAM in various cell types [3,9,10], FATP4 may activate palmitoyl-CoA leading to an alteration in lipid metabolism, ER-stress and subsequently apoptosis. Because FATP4 is broadly distributed in multiple metabolic active tissues such as adipose tissue, FATP4 has been shown to alter the programming from obese mouse mothers to preimplantation embryos [16], and is correlated with insulin resistance [17] and obesity [18]. While FATP4 is a minor FATP in the liver, we had chosen FATP4 as a representative enzyme for other ACSs and FATPs to determine whether it can mediate the typical Pal activation which would lead to apoptosis and well-defined lipid metabolism corresponding to its localization.…”

Section: Introductionmentioning

confidence: 99%

Palmitate activation by fatty acid transport protein 4 as a model system for hepatocellular apoptosis and steatosis

Seeßle¹,

Liebisch

Schmitz

et al. 2015

Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biolog

View full text Add to dashboard Cite

Differences in transport of fatty acids and expression of fatty acid transporting proteins in adipose tissue of obese black and white women

Cited by 31 publications

References 29 publications

Fat depot-related differences in gene expression, adiponectin secretion, and insulin action and signalling in human adipocytes differentiated in vitro from precursor stromal cells

Fat depot-related differences in gene expression, adiponectin secretion, and insulin action and signalling in human adipocytes differentiated in vitro from precursor stromal cells

Protein-Mediated Fatty Acid Uptake: Novel Insights from In Vivo Models

Palmitate activation by fatty acid transport protein 4 as a model system for hepatocellular apoptosis and steatosis

Contact Info

Product

Resources

About