Anti-inflammatory ω-3 endocannabinoid epoxides.

Clinical studies suggest that diets rich in ω-3 polyunsaturated fatty acids (PUFAs) provide beneficial anti-inflammatory effects, in part through their conversion to bioactive metabolites. Here we report on the endogenous production of a previously unknown class of ω-3 PUFA-derived lipid metabolites that originate from the crosstalk between endocannabinoid and cytochrome P450 (CYP) epoxygenase metabolic pathways. The ω-3 endocannabinoid epoxides are derived from docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) to form epoxyeicosatetraenoic acid-ethanolamide (EEQ-EA) and epoxydocosapentaenoic acid-ethanolamide (EDP-EA), respectively. Both EEQ-EAs and EDP-EAs are endogenously present in rat brain and peripheral organs as determined via targeted lipidomics methods. These metabolites were directly produced by direct epoxygenation of the ω-3 endocannabinoids, docosahexanoyl ethanolamide (DHEA) and eicosapentaenoyl ethanolamide (EPEA) by activated BV-2 microglial cells, and by human CYP2J2. Neuroinflammation studies revealed that the terminal epoxides 17,18-EEQ-EA and 19,20-EDP-EA dose-dependently abated proinflammatory IL-6 cytokines while increasing anti-inflammatory IL-10 cytokines, in part through cannabinoid receptor-2 activation. Furthermore the ω-3 endocannabinoid epoxides 17,18-EEQ-EA and 19,20-EDP-EA exerted antiangiogenic effects in human microvascular endothelial cells (HMVEC) and vasodilatory actions on bovine coronary arteries and reciprocally regulated platelet aggregation in washed human platelets. Taken together, the ω-3 endocannabinoid epoxides' physiological effects are mediated through both endocannabinoid and epoxyeicosanoid signaling pathways. In summary, the ω-3 endocannabinoid epoxides are found at concentrations comparable to those of other endocannabinoids and are expected to play critical roles during inflammation in vivo; thus their identification may aid in the development of therapeutics for neuroinflammatory and cerebrovascular diseases.

Recent advances in nanodisc technology for membrane protein studies (2012-2017).

Historically, the main barrier to membrane protein investigations has been the tendency of membrane proteins to aggregate (due to their hydrophobic nature), in aqueous solution as well as on surfaces. The introduction of biomembrane mimetics has since stimulated momentum in the field. One such mimetic, the nanodisc (ND) system, has proved to be an exceptional system for solubilizing membrane proteins. Herein, we critically evaluate the advantages and imperfections of employing nanodiscs in biophysical and biochemical studies. Specifically, we examine the techniques that have been modified to study membrane proteins in nanodiscs. Techniques discussed here include fluorescence microscopy, solution-state/solid-state nuclear magnetic resonance, electron microscopy, small-angle X-ray scattering, and several mass spectroscopy methods. Newer techniques such as SPR, charge-sensitive optical detection, and scintillation proximity assays are also reviewed. Lastly, we cover how nanodiscs are advancing nanotechnology through nanoplasmonic biosensing, lipoprotein-nanoplatelets, and sortase-mediated labeling of nanodiscs.