Lipidomic analysis of lipid mediators derived from cyclooxygenase‐1 and ‐2 pathways reveals their new implications in skeletal muscle

Resolution of inflammation is an active phenomenon to switch off the inflammatory processes andfacilitate the return to homeostasis. Increasing the levels of pro-resolving lipid mediators topromote the resolution of inflammation is emerging as a novel therapeutic approach. Arachidonicacid (AA) and docosahexaenoic acid (DHA) are substrates to produce the pro-resolving lipidmediators lipoxin A4 (LXA4) and resolvin D1 (RvD1), respectively. However, it is unknown if thesemediators can ameliorate dysfunction in arteries from hypertensive animals. Therefore, wehypothesized that pro-resolving lipid mediators decrease acetylcholine-induced contractions inarteries from spontaneously hypertensive rats (SHR). Mesenteric resistance arteries from maleSHR and Wistar Kyoto (WKY) (14-weeks old, n=6-8) were used for vascular function via wiremyograph. MRA were incubated with either RvD1 or LXA4 (10 nM, 1 hour) or vehicle prior toconcentration response curves to acetylcholine or phenylephrine (1 nM - 3 μM). We alsoperformed lipidomic analysis on plasma from WKY and SHR. As expected, low concentrations (≤100 nM) of acetylcholine induced relaxation in arteries from both groups, however highconcentrations (≥ 1 μM) of acetylcholine induced contraction in arteries from SHR, but not in WKY[Relaxation to acetylcholine [Area Under the curve (AUC)]: WKY: 396.6 ± 17.7 vs. SHR-control:296.0 ± 26.7*, t-test *vs. WKY, p=0.03). Treatment with the mediators did not change relaxationin arteries from WKY (AUC: Vehicle: 396.6 ±17.7 vs. RvD1: 402.8 ± 18.0; LXA4: 399.0 ± 18.4,p>0.05). However, incubation with RvD1 or LXA4 reduced acetylcholine induced-contraction inarteries from SHR (AUC: Vehicle: 296.0 ± 26.7 vs. RvD1: 372.5 ± 18.5*; LXA4: 376.8 ± 23.6*, t-test *vs. vehicle, p<0.05). Lipidomic analysis showed that precursors for pro-resolving lipidmediators are decreased in SHR [DHA (pmol/mL): WKY: 5637.5 ± 275.3 vs. SHR: 4509.2 ±453.9*, AA: WKY:16018.3 ± 351.3 vs. SHR: 13928.5 ± 959.5 *vs. WKY, p<0.05]. Overall, theseresults suggest that resolution of inflammation and the pro-resolving lipid mediators, RvD1 orLXA4, may be used as a new therapeutic tool to improve vascular function in hypertension.

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Molecular Circuits of Resolution in the Eye

The Scientific World JOURNAL ◽

10.1100/tsw.2010.99 ◽

2010 ◽

Vol 10 ◽

pp. 1029-1047 ◽

Cited By ~ 13

Author(s):

Elvira L. Liclican ◽

Karsten Gronert

Keyword(s):

Vascular Tone ◽

Inflammatory Responses ◽

Protective Action ◽

Lipid Mediators ◽

Dietary Manipulation ◽

Immune Functions ◽

Visual Axis ◽

Lipidomic Analysis ◽

Pathological Angiogenesis ◽

Successful Execution

Lipid autacoids have well-established key roles in physiology and pathophysiology. Eicosanoids derived from ω-6 arachidonic acid (AA) have long been recognized for their roles in cardiovascular and renal functions, and vascular tone, as well as regulating inflammatory and immune functions. It is now appreciated that AA is a substrate for generating lipid mediators with anti-inflammatory and proresolving properties, namely lipoxins (i.e., LXA4), which are an integral component for the successful execution of beneficial and essential acute inflammatory responses. In addition to AA, the ω-3 polyunsaturated fatty acids (PUFAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) also serve as substrates to generate potent and protective autacoids, such as resolvins and neuroprotectin (i.e., NPD1), respectively. These ω-3–derived signals may mediate the remarkable protective action of essential dietary ω-3 PUFAs. Formation and bioactivity of lipid mediators in the eye are relatively unexplored and of considerable interest, as the eye contains highly specialized tissues, including the transparent avascular and immune-privileged cornea, and the neuro-retina. A rapidly emerging field has identified key biosynthetic enzymes, receptors, and temporally defined endogenous formation of ω-3– and ω-6–derived protective lipid circuits in the eye. Protective endogenous roles of LXA4 and NPD1 have been established utilizing lipidomic analysis, knockout mice, and pharmacological, genetic, and dietary manipulation, providing compelling evidence that these intrinsic lipid autacoid circuits play essential roles in restraining inflammation, promoting wound healing, inhibiting pathological angiogenesis, and providing neuroprotection in the delicate visual axis.

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The influence of acute resistance exercise on cyclooxygenase-1 and -2 activity and protein levels in human skeletal muscle

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00593.2012 ◽

2013 ◽

Vol 305 (1) ◽

pp. R24-R30 ◽

Cited By ~ 15

Author(s):

Chad C. Carroll ◽

Devin T. O'Connor ◽

Robert Steinmeyer ◽

Jonathon D. Del Mundo ◽

David R. McMullan ◽

...

Keyword(s):

Skeletal Muscle ◽

Resistance Exercise ◽

Total Protein ◽

Human Skeletal Muscle ◽

Vastus Lateralis ◽

Knee Extensor ◽

Protein Levels ◽

Cyclooxygenase 1 ◽

Cox 2 ◽

Cox 1

This study evaluated the activity and content of cyclooxygenase (COX)-1 and -2 in response to acute resistance exercise (RE) in human skeletal muscle. Previous work suggests that COX-1, but not COX-2, is the primary COX isoform elevated with resistance exercise in human skeletal muscle. COX activity, however, has not been assessed after resistance exercise in humans. It was hypothesized that RE would increase COX-1 but not COX-2 activity. Muscle biopsies were taken from the vastus lateralis of nine young men (25 ± 1 yr) at baseline (preexercise), 4, and 24 h after a single bout of knee extensor RE (three sets of 10 repetitions at 70% of maximum). Tissue lysate was assayed for COX-1 and COX-2 activity. COX-1 and COX-2 protein levels were measured via Western blot analysis. COX-1 activity increased at 4 h ( P < 0.05) compared with preexercise, but returned to baseline at 24 h (PRE: 60 ± 10, 4 h: 106 ± 22, 24 h: 72 ± 8 nmol PGH2·g total protein−1·min−1). COX-2 activity was elevated at 4 and 24 h after RE ( P < 0.05, PRE: 51 ± 7, 4 h: 100 ± 19, 24 h: 98 ± 14 nmol PGH2·g total protein−1·min−1). The protein level of COX-1 was not altered ( P > 0.05) with acute RE. In contrast, COX-2 protein levels were nearly 3-fold greater ( P > 0.05) at 4 h and 5-fold greater ( P = 0.06) at 24 h, compared with preexercise. In conclusion, COX-1 activity increases transiently with exercise independent of COX-1 protein levels. In contrast, both COX-2 activity and protein levels were elevated with exercise, and this elevation persisted to at least 24 h after RE.

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Lipidomic Analysis of Endocannabinoid Signaling: Targeted Metabolite Identification and Quantification

Neural Plasticity ◽

10.1155/2016/2426398 ◽

2016 ◽

Vol 2016 ◽

pp. 1-13 ◽

Cited By ~ 12

Author(s):

Jantana Keereetaweep ◽

Kent D. Chapman

Keyword(s):

Mass Spectrometry ◽

G Protein ◽

Tissue Damage ◽

Cannabinoid Receptors ◽

Metabolite Identification ◽

Lipid Mediators ◽

Biologically Active ◽

Lipidomic Analysis ◽

Pathological Conditions ◽

G Protein Coupled

The endocannabinoidsN-arachidonoylethanolamide (or anandamide, AEA) and 2-arachidonoylglycerol (2-AG) belong to the larger groups ofN-acylethanolamines (NAEs) and monoacylglycerol (MAG) lipid classes, respectively. They are biologically active lipid molecules that activate G-protein-coupled cannabinoid receptors found in various organisms. After AEA and 2-AG were discovered in the 1990s, they have been extensively documented to have a broad range of physiological functions. Along with AEA, several NAEs, for example,N-palmitoylethanolamine (PEA),N-stearoylethanolamine (SEA), andN-oleoylethanolamine (OEA) are also present in tissues, usually at much larger concentrations than AEA. Any perturbation that involves the endocannabinoid pathway may subsequently alter basal level or metabolism of these lipid mediators. Further, the altered levels of these molecules often reflect pathological conditions associated with tissue damage. Robust and sensitive methodologies to analyze these lipid mediators are essential to understanding how they act as endocannabinoids. The recent advances in mass spectrometry allow researchers to develop lipidomics approaches and several methodologies have been proposed to quantify endocannabinoids in various biological systems.

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