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Ahowesso C, Black PN, Saini N, Montefusco D, Chekal J, Malosh C, Lindsley CW, Stauffer SR, DiRusso CC. Chemical inhibition of fatty acid absorption and cellular uptake limits lipotoxic cell death. Biochem Pharmacol 2015; 98:167-81. [PMID: 26394026 DOI: 10.1016/j.bcp.2015.09.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 09/03/2015] [Indexed: 12/31/2022]
Abstract
Chronic elevation of plasma free fatty acid (FFA) levels is commonly associated with obesity, type 2 diabetes, cardiovascular disease and some cancers. Experimental evidence indicates FFA and their metabolites contribute to disease development through lipotoxicity. Previously, we identified a specific fatty acid transport inhibitor CB16.2, a.k.a. Lipofermata, using high throughput screening methods. In this study, efficacy of transport inhibition was measured in four cell lines that are models for myocytes (mmC2C12), pancreatic β-cells (rnINS-1E), intestinal epithelial cells (hsCaco-2), and hepatocytes (hsHepG2), as well as primary human adipocytes. The compound was effective in inhibiting uptake with IC50s between 3 and 6μM for all cell lines except human adipocytes (39μM). Inhibition was specific for long and very long chain fatty acids but had no effect on medium chain fatty acids (C6-C10), which are transported by passive diffusion. Derivatives of Lipofermata were evaluated to understand structural contributions to activity. Lipofermata prevented palmitate-mediated oxidative stress, induction of BiP and CHOP, and cell death in a dose-dependent manner in hsHepG2 and rnINS-1E cells, suggesting it will prevent induction of fatty acid-mediated cell death pathways and lipotoxic disease by channeling excess fatty acids to adipose tissue and away from liver and pancreas. Importantly, mice dosed orally with Lipofermata were not able to absorb (13)C-oleate demonstrating utility as an inhibitor of fatty acid absorption from the gut.
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Affiliation(s)
- Constance Ahowesso
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0664, United States
| | - Paul N Black
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0664, United States
| | - Nipun Saini
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0664, United States
| | - David Montefusco
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0664, United States
| | - Jessica Chekal
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0664, United States
| | - Chrysa Malosh
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, United States; Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, TN 37232, United States
| | - Craig W Lindsley
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, United States; Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, TN 37232, United States; Department of Chemistry, Vanderbilt University, Nashville, TN 37232, United States
| | - Shaun R Stauffer
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, United States; Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, TN 37232, United States; Department of Chemistry, Vanderbilt University, Nashville, TN 37232, United States
| | - Concetta C DiRusso
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0664, United States.
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Saini N, Black PN, Montefusco D, DiRusso CC. Fatty acid transport protein-2 inhibitor Grassofermata/CB5 protects cells against lipid accumulation and toxicity. Biochem Biophys Res Commun 2015; 465:534-41. [PMID: 26284975 DOI: 10.1016/j.bbrc.2015.08.055] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 08/12/2015] [Indexed: 01/05/2023]
Abstract
The inhibition of the fatty acid uptake into non-adipose tissues provides an attractive target for prevention of lipotoxicity leading to obesity-associated non-alcoholic fatty liver disease and type 2 diabetes. Fatty acid transport proteins (FATPs) are bifunctional proteins involved in the uptake and activation of fatty acids by esterification with coenzyme A. Here we characterize Grassofermata/CB5, previously identified as a fatty acid uptake inhibitor directed against HsFATP2. The compound was effective in inhibiting the uptake of fatty acids in the low micro-molar range (IC50 8-11 μM) and prevented palmitate-mediated lipid accumulation and cell death in cell lines that are models for intestines, liver, muscle and pancreas. In adipocytes, uptake inhibition was less effective (IC50 58 μM). Inhibition was specific for long chain fatty acids and was ineffective toward medium chain fatty acids, which are transported by diffusion. Kinetic analysis of Grassofermata-dependent FA transport inhibition verified a non-competitive mechanism. By comparison with Grassofermata, several atypical antipsychotic drugs previously implicated as inhibitors of FA uptake were ineffectual. In mice Grassofermata decreased absorption of (13)C-oleate demonstrating its potential as a therapeutic agent.
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