Endothelial Acyl-CoA Synthetase 1 Is Not Required for Inflammatory and Apoptotic Effects of a Saturated Fatty Acid-Rich Environment

Saturated fatty acids, such as palmitic and stearic acid, cause detrimental effects in endothelial cells (ECs) and have been suggested to contribute to macrophage accumulation in adipose tissue and the vascular wall in states of obesity and insulin resistance. Long-chain fatty acids are believed to require conversion into acyl-CoA derivatives to exert most of their detrimental effects, a reaction catalyzed by acyl-CoA synthetases (ACSL). The objective of this study was to investigate the role of ACSL1, an ACSL isoform previously shown to mediate inflammatory effects in myeloid cells, in regulating EC responses to a saturated fatty acid-rich environment in vitro and in vivo

Diabetes promotes an inflammatory macrophage phenotype and atherosclerosis through acyl-CoA synthetase 1

Author contributions: J.E.K., L.B., C.N.S., and K.E.B. designed research; J.E.K., F.K., S.B., M.M.A., A.V.-G., T.V., L.O.L., L.B., K.R.B., and S.P.-P. performed research; W.Y., A.C., S.S., T.N.W., J.W.H., and R.A.C. contributed new reagents/analytic tools; J.E.K., L.B., S.S., S.P., and K.E.B. analyzed data; and J.E.K. and K.E.B. wrote the paper

Metabolomic Profiling Reveals a Role for Androgen in Activating Amino Acid Metabolism and Methylation in Prostate Cancer Cells

Prostate cancer is the second leading cause of cancer related death in American men. Development and progression of clinically localized prostate cancer is highly dependent on androgen signaling. Metastatic tumors are initially responsive to anti-androgen therapy, however become resistant to this regimen upon progression. Genomic and proteomic studies have implicated a role for androgen in regulating metabolic processes in prostate cancer. However, there have been no metabolomic profiling studies conducted thus far that have examined androgen-regulated biochemical processes in prostate cancer. Here, we have used unbiased metabolomic profiling coupled with enrichment-based bioprocess mapping to obtain insights into the biochemical alterations mediated by androgen in prostate cancer cell lines. Our findings indicate that androgen exposure results in elevation of amino acid metabolism and alteration of methylation potential in prostate cancer cells. Further, metabolic phenotyping studies confirm higher flux through pathways associated with amino acid metabolism in prostate cancer cells treated with androgen. These findings provide insight into the potential biochemical processes regulated by androgen signaling in prostate cancer. Clinically, if validated, these pathways could be exploited to develop therapeutic strategies that supplement current androgen ablative treatments while the observed androgen-regulated metabolic signatures could be employed as biomarkers that presage the development of castrate-resistant prostate cancer

Establishing 3-nitrotyrosine as a biomarker for the vasculopathy of Fabry disease

The endothelial dysfunction of Fabry disease results from α-galactosidase A deficiency leading to the accumulation of globotriaosylceramide. Vasculopathy in the α-galactosidase A null mouse is manifested as oxidant-induced thrombosis, accelerated atherogenesis, and impaired arterial reactivity. To better understand the pathogenesis of Fabry disease in humans, we generated a human cell model by using RNA interference. Hybrid endothelial cells were transiently transfected with small interfering RNA (siRNA) specifically directed against α-galactosidase A. Knockdown of α-galactosidase A was confirmed using immunoblotting and globotriaosylceramide accumulation. Endothelial nitric oxide synthase (eNOS) activity was correspondingly decreased by >60%. Levels of 3-nitrotyrosine (3NT), a specific marker for reactive nitrogen species and quantified using mass spectrometry, increased by 40- to 120-fold without corresponding changes in other oxidized amino acids, consistent with eNOS-derived reactive nitrogen species as the source of the reactive oxygen species. eNOS uncoupling was confirmed by the observed increase in free plasma and protein-bound aortic 3NT levels in the α-galactosidase A knockout mice. Finally, 3NT levels, assayed in biobanked plasma samples from patients with classical Fabry disease, were over sixfold elevated compared with age- and gender-matched controls. Thus, 3NT may serve as a biomarker for the vascular involvement in Fabry diseas

Supplementary Materials

2 supplementary figures and 1 table to go with published manuscript.Abstract OBJECTIVES: Patients with systemic lupus erythematosus (SLE) have a striking increase in atherothromboticcardiovascular disease (CVD), not explained by the Framingham risk equation. In vitrostudies indicate that type-I Interferons (IFNs) may play prominent roles in increased CV risk in SLE. However, the in vivo relevance of these findings, with regards to the development of CVD, has not been characterized. We examinedthe role of type-I IFNs in endothelial dysfunction, aberrant vascular repair, and atherothrombosis in murine models of lupus and atherosclerosis. METHODS: Lupus-prone New Zealand Mixed-2328 mice (NZM) and atherosclerosis-prone Apolipoprotein-E-knockout mice (ApoE-/-) were compared to mice lacking type-I IFN-receptor (INZM and ApoEIFNR-/-, respectively) in their endothelial vasodilatory function, endothelial progenitor cell (EPC)function, in vivoneoangiogenesis, plaque development and occlusive thrombosis. Similar experiments were performed when NZM and ApoE-/- received an IFN-α-containing or an empty adenovirus. RESULTS: Loss of type I-IFN-receptor signaling improves endothelium-dependent vasorelaxation, lipoprotein parameters, EPC numbers and function and neoangiogenesis in lupus-prone mice, independent of disease activity or gender. Further, acute exposure to IFN-α impairs endothelial vasorelaxation and EPC function in lupus-prone and non-lupus-prone mice. ApoEIFNR-/- mice have decreased atherosclerosis severity and arterialinflammatory infiltratesand increased neoangiogenesis, compared to ApoE-/- mice, whileNZM and ApoE(-/-) mice exposed to IFN-αdevelop accelerated thrombosis and platelet activation. CONCLUSIONS: These results support the hypothesis that type I-IFNs play key roles in the development of premature CVD in SLE and, potentially, in the general population, through pleiotropic deleterious effects on the vasculature. Copyright © 2012 by the American College of RheumatologyPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/92474/1/Kaplan_Supplements Arth & Rheum 2012 Thacker et al.pd

Angiotensin II type 1A receptors in vascular smooth muscle cells do not influence aortic remodeling in hypertension

10.1161/HYPERTENSIONAHA.110.165274Hypertension573 PART 2577-585HPRT

Inflammatory Stimuli Induce Acyl-CoA Thioesterase 7 and Remodeling of Phospholipids Containing Unsaturated Long ( 65C20)-Acyl Chains in Macrophages

Acyl-CoA thioesterase 7 (ACOT7) is an intracellular enzyme that converts acyl-CoAs to free fatty acids. ACOT7 is induced by lipopolysaccharide (LPS), thus we investigated downstream effects of LPS-induced induction of ACOT7 and its role in inflammatory settings in myeloid cells. Enzymatic thioesterase activity assays in wildtype and ACOT7-deficient macrophage lysates indicated that endogenous ACOT7 contributes a significant fraction of total acyl-CoA thioesterase activity towards C20:4-CoA, C20:5-CoA and C22:6-CoA, but contributes little activity towards shorter acyl-CoA species. Lipidomic analyses revealed that LPS causes a dramatic increase primarily in bis(monoacylglycero)phosphate species containing long ( 65C20) polyunsaturated acyl-chains in macrophages, and that the limited effect observed by ACOT7-deficiency is restricted to glycerophospholipids containing 20-carbon unsaturated acyl-chains. Furthermore, ACOT7-deficiency did not detectably alter the ability of LPS to induce cytokines or prostaglandin E2 production in macrophages. Consistently, although ACOT7 was induced in macrophages from diabetic mice, hematopoietic ACOT7-deficiency did not alter the stimulatory effect of diabetes on systemic inflammation or atherosclerosis in LDL receptor-deficient mice. Thus, inflammatory stimuli induce ACOT7 and remodeling of phospholipids containing unsaturated long ( 65C20)-acyl chains in macrophages, and though ACOT7 has preferential thioesterase activity toward these lipid species, loss of ACOT7 has no major detrimental effect on macrophage inflammatory phenotypes

Endothelial Acyl-CoA Synthetase 1 Is Not Required for Inflammatory and Apoptotic Effects of a Saturated Fatty Acid-Rich Environment

OBJECTIVE: Saturated fatty acids, such as palmitic and stearic acid, cause detrimental effects in endothelial cells (ECs) and have been suggested to contribute to macrophage accumulation in adipose tissue and the vascular wall in states of obesity and insulin resistance. Long-chain fatty acids are believed to require conversion into acyl-CoA derivatives to exert most of their detrimental effects, a reaction catalyzed by acyl-CoA synthetases (ACSL). The objective of this study was to investigate the role of ACSL1, an ACSL isoform previously shown to mediate inflammatory effects in myeloid cells, in regulating EC responses to a saturated fatty acid-rich environment in vitro and in vivo. METHODS AND RESULTS: Saturated fatty acids caused increased inflammatory activation, ER stress, and apoptosis in mouse microvascular ECs. Forced ACSL1 overexpression exacerbated the effects of saturated fatty acids on apoptosis and ER stress. However, endothelial ACSL1-deficiency did not protect against the effects of saturated fatty acids in vitro, nor did it protect insulin resistant mice fed a saturated fatty acid-rich diet from macrophage adipose tissue accumulation or increased aortic adhesion molecule expression. CONCLUSION: Endothelial ACSL1 is not required for inflammatory and apoptotic effects of a saturated fatty acid-rich environment