Table 1A.
Metabolites of arachidonic acid (AA) in inflammation and pain.
| Animals/tissue/cell type | Effect | Signaling | Experiment | Experimental details | Target | Refs. |
|---|---|---|---|---|---|---|
| 5,6-EET | ||||||
| Cerebral arterioles of tsA-201 cells, CaV3.1 KO and CaV3.2 KO mice, tsA-201 cells | Dilation | Inhibition of T-type calcium channels | In vivo, in vitro | Transfection, electrophysiological recordings, microperfusion of mesenteric resistance arteries | Cav3.1, Cav3.2, Cav3.3 | (Dennis et al., 2011; Cazade et al., 2014) |
| Nude and C57Bl/6 mice, RAW264.7 cells, bone marrow derived macrophages | Proinflammatory | Proinflammatory cytokine production | In vitro, in vivo cupping therapy | Ultra-performance liquid chromatography – tandem mass spectrometry (UPLC-MS/MS), cupping treatment, enzyme-linked immunosorbent assay (ELISA), fluorescence-activated cell sorting (FACS) analysis | (Zhang et al., 2018) | |
| bovine aortic endothelial cells, HUVECs, 3T3-L1 | Activation of PPARγ-regulated transcription | In vitro | Transfection, PPARγ-competition binding assay with [3H]rosiglitazone, plate flow for laminar shear stress experiments, quantitative real-time polymerase chain reaction (qPCR), sEH activity assay, reverse-phase high performance liquid chromatography (HPLC), lipid quantification by Quattro Ultima tandem quadrupole mass spectrometer, immunoblotting analysis | PPARγ | (Liu et al., 2005; Hiesinger et al., 2019) | |
| pulmonary murine microvascular endothelial cells | no | PI3K/Akt pathway activation, proliferation, migration | In vitro | stimulation with EETs/DHETs and quantification with NICI/GC/MS, proliferation assay with [3H]thymidine, transwell migration assay, matrigel-based capillary formation assay, Western Blot, qPCR, in vivo angiogenesis in subcutaneous sponge model, immunofluorescence of tumors from human non-small cell lung cancer cells | (Pozzi et al., 2005) | |
| CHO-K1 cells, BV-2 microglial cells, BALB/c mice brain tissue | Activation of CB2 receptor | In vitro | transfection, preparation of membranes and binding assays with CB1/CB2 agonists, competition binding assays, cAMP inhibition assays, whole-cell metabolism assay, immunoblot, ESI-LC/MS | Human CB2 | (Snider et al., 2009) | |
| C57Bl/6 mice, TRPA1-deficient mice (B6129PF2/J), DRG cultures | Mechanical allodynia | In vivo | licking time, dynamic plantar and hargreaves behavioral studies, injection of 5,6-EET in hindpaw, Ca-imaging, LC-MS/MS, patch-clamp recordings | TRPA1 | (Sisignano et al., 2012) | |
| HEK-293 cells, | pronociceptive | In vitro, | Ca-imaging, patch-clamp | TRPV4 | (Watanabe et al., 2003) | |
| 8,9-EET | ||||||
| human endothelial cell, human coronary artery tissue, vascular smooth muscle cells, bovine aortic endothelial cells | Antiinflammatory | IKκ and NF-κB inhibition | In vitro | qPCR, immunohistochemistry (IHC), reversed-phase HPLC, cell-surface enzyme immunoassay, Western Blot, TNFα stimulation | PPARγ | (Node et al., 1999) |
| DRG neurons, pulmonary murine microvascular endothelial cells |
p38 MAPK, ERK pathway | In vitro, in vivo angiogenesis | stimulation with EETs/DHETs and quantification with NICI/GC/MS, proliferation assay with [3H]thymidine, transwell migration assay, matrigel-based capillary formation assay, Western Blot, qPCR, in vivo angiogenesis in subcutaneous sponge model, immunofluorescence of tumors from human non-small cell lung cancer cells | (Obata and Noguchi, 2004; Pozzi et al., 2005) | ||
| C57BL/6 WT and sEH KO mice, DRG cultures | Mechanical allodynia | Calcium influx | In vivo | injection of lipids or zymosan in hindpaw, Dynamic Plantar behavioral studies, Western Blot analysis, multi-epitope-ligand-cartography (MELC), Ca-Imaging, CGRP-enzyme immunoassay (EIA), LC-MS/MS | TRPA1 | (Brenneis et al., 2011) |
| HUVECs, HCaECs, HaoSMCs, BCAECs, HEK-293, INS-1 832/13 | Calcium influx | In vitro | transfection of GPCRs, [Ca2+] assay with fluorescence, radioligand binding assay, qPCR, immunoblotting, Western Blot, isometric tension measurement, whole-cell patch-clamp | GPR40, GPR120 | (Park et al., 2018) | |
| 11,12-EET | ||||||
| small bovine coronary arteries, coronary arterial endothelial cells, vascular smooth muscle cells TRVP4 KO mice, second branch order mesenteric resistance arteries |
dilation, hyperpolarization | Stimulation of endogenous ADP-ribosylation through GSα, activation of TRPV4-like currents | in vitro | vasodilation/-constriction experiments, Patch-clamp electrophysiology | TRPV4, KCa | (Li et al., 1999; Earley et al., 2009) |
| Sprague-Dawley rats, mononuclear cells | attenuation of PGE2 | In vitro | LPS-stimulation of monocytes, PGE2 assay in supernatant of monocytes, Western Blot of COX-2 protein, COX-2 activity assay with [14C]AA | (Kozak et al., 2003) | ||
| wound tissue of naked SKH-1 mice | Proinflammatory | VEGF and TGFβ expression | In vivo | ischemia of the mouse ear, wound creating by circular punch, treatment of wound with different EETs, direct visualization of epithelialization, IHC | (Sommer et al., 2019) | |
| bovine aortic endothelial cells, HUVECs, human coronary artery tissue, vascular smooth muscle cells, Sprague-Dawley rats, RPAECs | Antiinflammatory | Inhibition of p38, degradation IκBα and inhibition of NF-κB, LOX-1 receptor suppression, inhibition of COX-2 | In vitro | qPCR, IHC, reversed-phase HPLC, cell-surface enzyme immunoassay, TNFα stimulation experiments Immunofluorescence, Cell viability via MTT, extraction of cytosolic and nuclear fractions, Western Blot, ELISA |
(Node et al., 1999; Liu et al., 2005) (Jiang et al., 2014; Sommer et al., 2019) | |
| HUVECs, HCaECs, HaoSMCs, BCAECs, HEK-293, INS-1 832/13 | Proinflammatory | Calcium influx, ERK phosphorylation, COX-2 expression, gab junction, disassembly, cAMP increase | In vitro, in vivo | transfection of GPRs, [Ca2+] assay with fluorescence, radioligand binding assay, qPCR, immunoblotting, Western Blot, whole-cell patch-clamp | GPR40 | (Thompson and Hammock, 2007; Morisseau et al., 2010; Park et al., 2018) |
| Hippocampus of C57Bl/6 mice | Antinocicpetive | Reduced excitatory transmission | In vitro | IHC of brain tissue, electrophysiology | GIRK1/4 | (Mule et al., 2017) |
| 14,15-EET | ||||||
| Nude and C57Bl/6 mice, RAW264.7 cells, bone marrow derived macrophages | Antiinflmmatory | NF-κB inhibition, decrease TNFα expression, decrease IL-6, | in vitro, in vivo cupping therapy | UPLC-MS/MS, cupping treatment, ELISA, FACS analysis | (Zhang et al., 2018) | |
| porcine thoracic aortic smooth muscle cells (SMC) from SJL mice, brain microvessel, human lung tissue, bronchial ring, Spraque-Dawley rats, BKCa KO mice, EP3 KO mice, guinea pigs, TRPV4 KO mice, conduit smooth muscle rings and nonvascular smooth muscle strips | Antiinflammatory | Inhibition of PGH synthase, reduction of PGE2, vasodilation, inhibition of NF-κB induced transcription | In vitro | radiolabelled EETs and AA treatment of cells, revers-phase HPLC, PGE2 radioimmunoassay, mRNA analysis by sequential hybridization, Western Blot, DNA synthesis analysis by using [3H]thymidine, treatment of bronchial rings with TNFα, EET and AUDA, isometric tension measurements, qPCR, tissue relaxation and contraction experiments, platelet aggregation, competition binding assay, selectivity profile of EET and DHET and human TP receptor and GPRs, ion channels and transporters |
TP, EP2 | (Fang et al., 1998; Morin et al., 2008; Behm et al., 2009) |
| mouse mesenteric arteries, HEK-293 cells, follicular membranes of Xenopus laevis ooytes | In vitro | transfection, cAMP detection assay, oocyte expression system by injection of cRNA, cell surface expression of GPR detection, ERK phosphorylation detection by Western blot luminescence method, PathHunter β-arrestin enzyme fragment complementation assay | EP4, EP2, CXCR4 CMKLR1 | (Liu et al., 2017) | ||
| Hippocampus of C57Bl/6 mice | Antinociceptive | Reduced excitatory transmission | In vitro | IHC of brain tissue, electrophysiology | GIRK1/4 | (Mule et al., 2017) |
| Hippocampus of C57Bl/6 mice | PKA, ERK and CaMKII activation | In vitro | electrophysiological recordings of hippocampus, Western Blot analysis | (Wu et al., 2017) | ||
| Brain of Sprague-Dawley rats | Antinociceptive | Activation of β-endorphin and met-enkephalin | In vivo | Ventrolateral periaqueductal grey matter (vlPAG) microinjection, tail-flick response measurement after radiant heat application, treatment with different drugs, AA or EETs, membrane binding assay of 14,15-EET with μ and δ-opioid receptors | (Terashvili et al., 2008) | |
| Sprague-Dawley rats, primary cortical and sensory neuron culture | Antinociceptive | Axon growth through endogenous 14,15-EET | In vitro | Immunocytochemistry, MTT assay of cell viability, morphometric analyses by staining with Protein Gene Product 9.5 or tau-specific antibody, LC-quantification of EETs | (Abdu et al., 2011) | |
| 14,15-DHET | ||||||
| HepG2 cells, primary hepatocytes of Sprague-Dawley rats, primary cortical neuron culture | Proinflammatory | Inhibition axon growth | In vitro | transactivation assay, liquid chromatography – mass spectrometry (LCMS), gel shift assay, qPCR, immunocytochemistry, MTT assay of cell viability, morphometric analyses by staining with Protein Gene Product 9.5 or tau-specific antibody, LC-quantification of EET | PPARα and γ | (Ng et al., 2007; Abdu et al., 2011) |
CaMKII, Ca2+/calmodulin-dependent protein kinase II; cAMP, cytosolic adenosine monophosphate; Cav3, T-type calcium channel 3; CCL, chemokine ligand; COX, cyclooxygenase; cRNA, Complementary RNA; DHET, Dihydroxyeicosatrienoic acid; DRG, dorsal root ganglion; EET, epoxyeicosatrienoic acid; ELISA, enzyme-linked immunosorbent assay; EP, prostaglandin E receptor; ER, endoplasmatic reticulum; ERK, extracellular-signal regulated kinase; ESI-LC/MS, electrospray ionization interface for liquid chromatography – mass spectrometry; FACS, fluorescence-activated cell sorting; GIRK, G-protein coupled inwardly rectifying potassium channel; GPR, GPCR, G protein-coupled receptor; HPLC, high performance liquid chromatography; IHC, immunohistochemistry; IKκ, inhibitor of nuclear factor kappa-B kinase; IL, interleukin; KO, knock-out; LC-MS, liquid chromatography–mass spectrometry; LOX, lipoxygenase; LPS, lipopolysaccharide; MAPK, mitogen-activated protein kinases; MELC, multi-epitope-ligand-cartography; MTT, 3(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; NF-κB, nuclear factor ‘kappa-light-chain-enhancer’; NICI/GC/MS, negative ion chemical ionization gas chromatography – mass spectrometry; NO, Nitric oxide; PG, prostaglandin; PI3K/Akt, phosphoinositide 3-kinase/protein kinase B; PKA, protein kinase A; PPAR, peroxisome proliferator-activated receptor; qPCR, quantitative real-time polymerase chain reaction; Refs: references; TGF, transforming growth factor; TNF, tumor necrosis factor; TP, thromboxane receptor; TPPU, N-[1-(1-Oxopropyl)-4-piperidinyl]-N’-[4-(trifluoromethoxy)phenyl]urea; TRPA, transient receptor potential ion channel ankyrin subtype; TRPM, transient receptor potential ion channel melastatin subtype; TRPV, transient receptor potential ion channel vanilloid subtype; UPLC-MS/MS, Ultra-performance liquid chromatography–tandem mass spectrometry; VEGF, vascular endothelial growth factor.