Mono (S) hydroxy fatty acids: novel ligands for cytosolic actin

Abstract

The ubiquitous hydroxylated fatty acids derived from arachidonic acid (HETEs) or linoleic acid (HODEs) exhibit diverse biological effects including chemotaxis, cell proliferation, and modulation of several enzymatic pathways, including the 5-lipoxygenase leading to the inflammatory leukotrienes. It was observed that 12(S)-and 15(S)-HETE and 13(S)-HODE (12-and 15-lipoxygenase-derived metabolites, respectively) inhibited the 5-lipoxygenase present in rat basophilic leukemia (RBL -1) cell homogenates whereas the 15(R) chiral enantiomer and the nonhydroxylated linoleic, oleic, and stearic acids were either less potent or ineffective. In examining the mechanism of this inhibition, the relative effectiveness of several fatty acids in displacing [ 3 H]15-HETE bound to cytosol preparations were compared and the results indicated that these (S) hydroxy fatty acids and 5(S)-HETE were significantly more potent than either the 15(R) enantiomer, 15(S)-HETE methyl ester, arachidonic acid, or prostaglandin F 2 ␣ . In order to identify the protein(s) that specifically binds HETEs, 15(S)-HETE biotin hydrazide was used as a probe to detect any HETEprotein complexes as this compound both inhibited the 5lipoxygenase and interfered with the binding of [ 3 H]15-HETE to cytosol preparations. SDS-PAGE analysis and chemiluminescent detection revealed that the major cytosolic proteins that bound this biotinylated probe had molecular masses of 43 and 51 kD. Fatty acid competition experiments indicated that the order of effectiveness in displacing this probe from these proteins was 13(S)-HODE Ͼ 5(S)-HETE Ϸ 15(S)-HETE Ͼ Ͼ stearic acid Ϸ arachidonic acid Ϸ 15(R)-HETE. Amino acid sequence analysis showed that the 43 kD protein was actin. These findings suggest the possibility that actin may play a major role in the biological effects of monohydroxylated metabolites derived from cellular 5-, 12-, and 15-lipoxygenases.-Kang, L-T., and J. Y. Vanderhoek. Mono (S) hydroxy fatty acids: novel ligands for cytosolic actin.

Eicosanoids participate in the regulation of cardiac glucose transport by contribution to a rearrangement of actin cytoskeletal elements

“…In the present investigation using ventricular cardiomyocytes, attempts have been made to correlate the activity of the 12-LO pathway with the organization of actin cytoskeletal elements, and to discover potential implications for GLUT4 trafficking and cardiac glucose uptake. This approach was based on (1) the recent demonstration that actin filaments participate in the exocytotic movement of GLUT4 [3], and (2) data showing that actin fibres might represent possible target proteins for eicosanoid metabolites of the LO pathway [7,8]. We report here a complete inhibition of insulin-induced glucose uptake by cytochalasin D in adult ventricular cardiomyocytes.…”

“…12-LO did not co-localise to the actin network. However, the 12-LO metabolite 12(S)-HETE was recently shown by Vanderhoek and co-workers [7,8] to be a ligand for actin cytoskeletal elements. Interestingly, the 12-LO pathway is stimulated in the myocardium by hypoxia or ischaemia [19,20,34].…”

“…Recent studies have focused on the involvement of hydroxyeicosatetraenoic acid (HETE) in the regulation of actin network organization. These eicosanoid metabolites of the lipoxygenase (LO) pathway have been shown to bind selectively to actin fibres [7,8]. Other groups have demonstrated that 12(S)-HETE, the product of 12-lipoxygenation of arachidonic acid, induces Abbreviations used : Cy3, indocarbocyanine ; 2-DOG, 2-deoxy-D-glucose ; ECL2 (Amersham), enhanced chemiluminescence ; FITC, fluorescein isothiocyanate ; GLUT4, glucose transporter isofom 4 ; HETE, hydroxyeicosatetraenoic acid ; IRS, insulin receptor substrate ; NHS-LC, Nhydroxysuccinimido-long chain ; LO, lipoxygenase ; NDGA, nordihydroguaiaretic acid ; PI 3-kinase, phosphatidylinositol 3-kinase.…”

Proteomic Analysis of Human Small Cell Lung Cancer Tissues: Up-Regulation of Coactosin-Like Protein-1

“…COTL-1 activates 5-lipoxygenase, an enzyme that converts arachidonic acid to LTA 4 and is involved in inflammatory disease, cancer development, and cell survival. In addition, actin binds to 5-lipoxygenase and associates with lipoxygenase metabolites to inhibit lipoxygenase. , Pharmacological inhibitors of lipoxygenase suppress carcinogenesis and tumor metastasis . Taken together, COTL-1 expression may interact with actin and 5-lipoxygenase to play a central role in SCLC.…”

“…In addition, actin binds to 5-lipoxygenase and associates with lipoxygenase metabolites to inhibit lipoxygenase. 37,38 Pharmacological inhibitors of lipoxygenase suppress carcinogenesis and tumor metastasis. 39 Taken together, COTL-1 expression may interact with actin and 5-lipoxygenase to play a central role in SCLC.…”