GO:0006690 icosanoid metabolic process: Lipid Signaling Pathway, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0006690 (icosanoid metabolic process) describes the chemical reactions and pathways involving icosanoids, a group of C20 polyunsaturated fatty acids.
• Icosanoids include prostaglandins, leukotrienes, thromboxanes, lipoxins, resolvins, and protectins, which are derived from arachidonic acid and related C20 fatty acids.
• The pathway is rapidly activated during infection and inflammation, a phenomenon termed the eicosanoid storm.
• Icosanoids are critical mediators of tissue repair, skin wound healing, and resolution of inflammation.
• Dysregulated icosanoid metabolism is implicated in preeclampsia, prostate cancer, and oncogenic PIK3CA-driven metabolic reprogramming.
• CRISPR-based knockout, knock-in, point-mutation, and overexpression models enable causal dissection of icosanoid pathway genes in disease contexts.
Description
Icosanoid metabolic process (GO:0006690) encompasses the chemical reactions and pathways involving icosanoids, which are a group of C20 polyunsaturated fatty acids and their oxygenated derivatives. These lipid mediators include prostaglandins, thromboxanes, leukotrienes, lipoxins, resolvins, and protectins, and they act as local hormones to regulate inflammation, immunity, tissue homeostasis, and repair. The term is a biological_process in the Gene Ontology and is synonymous with eicosanoid metabolic process, eicosanoid metabolism, and icosanoid metabolism. Researchers study this process because icosanoids are rapidly synthesized and released in response to infection or injury, and their dysregulation contributes to a broad spectrum of human diseases, including inflammatory disorders, cancer, and pregnancy-related pathologies.
icosanoid metabolic process At A Glance
| GO ID | GO:0006690 |
|---|---|
| GO term | icosanoid metabolic process |
| Ontology | biological_process |
| Synonym | eicosanoid metabolic process; eicosanoid metabolism; icosanoid metabolism |
| Major function | Biosynthesis and metabolism of C20 polyunsaturated fatty acid-derived lipid mediators |
| Key substrates | Arachidonic acid, eicosapentaenoic acid, docosahexaenoic acid |
| Major enzymes | Cyclooxygenases, lipoxygenases, cytochrome P450 epoxygenases |
| Representative products | Prostaglandins, leukotrienes, thromboxanes, lipoxins, resolvins, protectins |
| Associated diseases | Inflammation, infection, preeclampsia, prostate cancer, metabolic reprogramming in cancer |
What Is GO:0006690?
According to the Gene Ontology, GO:0006690 (icosanoid metabolic process) is defined as the chemical reactions and pathways involving icosanoids, any of a group of C20 polyunsaturated fatty acids. This definition captures both the biosynthesis and the further metabolism of these lipid mediators, including their oxidation, conjugation, and beta-oxidation. The term is classified under biological_process and is often used interchangeably with eicosanoid metabolic process, eicosanoid metabolism, and icosanoid metabolism.
Why Is icosanoid metabolic process Important in Cell Biology?
Icosanoid metabolic process is important because it governs the production of potent lipid mediators that control inflammation, immunity, tissue repair, and vascular tone. The rapid release of icosanoids during infection and inflammation, known as the eicosanoid storm, can determine the outcome of host-pathogen interactions and inflammatory diseases. In tissue repair and skin wound healing, specific icosanoids promote resolution and regeneration, making this pathway a therapeutic target. Moreover, dysregulated icosanoid metabolism is linked to preeclampsia, prostate cancer progression, and oncogenic signaling, underscoring its broad clinical relevance.
• Icosanoids are central mediators of acute and chronic inflammation, including the eicosanoid storm in infection.
• They regulate tissue repair and skin wound healing by promoting resolution and regeneration.
• The pathway is implicated in pregnancy disorders such as preeclampsia.
• Icosanoid metabolism is reprogrammed in prostate cancer and other malignancies.
• Oncogenic PIK3CA mutations enhance arachidonic acid-derived eicosanoid production, linking metabolism to cancer signaling.
• Protectins and other specialized pro-resolving mediators are synthesized through this pathway.
• Beta-oxidation of eicosanoids represents a catabolic arm that controls mediator clearance.
• Targeting icosanoid enzymes is a strategy for anti-inflammatory and anticancer drug development.
• CRISPR screens can identify novel regulators of icosanoid metabolism in disease models.
• Biomarkers of icosanoid metabolism may aid diagnosis and patient stratification.
What Happens During icosanoid metabolic process?
Release of C20 polyunsaturated fatty acids
In simple terms: The process starts when C20 fatty acids are freed from cell membranes.
Icosanoid metabolic process begins with the release of C20 polyunsaturated fatty acids, primarily arachidonic acid, from membrane phospholipids by phospholipases. These fatty acids serve as substrates for downstream oxygenation reactions. The availability of free arachidonic acid is a rate-limiting step in eicosanoid biosynthesis, and its release is tightly coupled to inflammatory and homeostatic signals.
Oxygenation by cyclooxygenases, lipoxygenases, and cytochrome P450
In simple terms: Enzymes add oxygen to the fatty acids to create different signaling molecules.
Once released, arachidonic acid is oxygenated by three major enzyme families: cyclooxygenases (COX-1 and COX-2), lipoxygenases (LOX), and cytochrome P450 epoxygenases. These enzymes produce prostaglandins, thromboxanes, leukotrienes, lipoxins, and epoxyeicosatrienoic acids. The specific enzyme profile of a cell determines which icosanoids are generated, shaping the inflammatory or resolving outcome.
Synthesis of specialized pro-resolving mediators
In simple terms: Some icosanoids actively shut down inflammation and help tissues heal.
Beyond classical prostaglandins and leukotrienes, the pathway produces specialized pro-resolving mediators such as resolvins, protectins, and maresins. The biosynthetic pathways of protectins, for example, involve lipoxygenase-mediated reactions from docosahexaenoic acid. These mediators promote the resolution of inflammation and tissue repair, and their production is a key homeostatic function of icosanoid metabolism.
Catabolism and beta-oxidation of icosanoids
In simple terms: The body breaks down these signaling molecules to stop their effects.
Icosanoids are inactivated through enzymatic degradation, including beta-oxidation, which shortens the fatty acid chain and reduces biological activity. This catabolic arm is essential for terminating inflammatory signals and preventing chronic inflammation. The balance between synthesis and degradation determines the local concentration and duration of action of each icosanoid.
Eicosanoid storm in infection and inflammation
In simple terms: During severe infection, the body releases a flood of these molecules.
In response to infection or severe inflammation, there is a massive and rapid release of icosanoids, termed the eicosanoid storm. This storm can amplify inflammation and contribute to tissue damage, but it also coordinates immune cell recruitment and pathogen clearance. Understanding the triggers and consequences of the eicosanoid storm is a major research focus in immunology and infectious disease.
Key Genes Involved in GO:0006690 icosanoid metabolic process
The following genes and enzymes are central to icosanoid metabolic process and are frequently studied in inflammation, cancer, and tissue repair research.
| Gene | Major Role | Research Relevance |
|---|---|---|
| PLA2G4A | Phospholipase A2 that releases arachidonic acid from membranes | Rate-limiting step in eicosanoid biosynthesis; target in inflammation |
| PTGS1 | Cyclooxygenase-1, constitutive prostaglandin synthesis | Housekeeping eicosanoid production; studied in tissue homeostasis |
| PTGS2 | Cyclooxygenase-2, inducible prostaglandin synthesis | Key inflammatory enzyme; target of NSAIDs and cancer research |
| ALOX5 | 5-lipoxygenase, leukotriene biosynthesis | Leukotriene production in asthma and inflammation |
| ALOX12 | 12-lipoxygenase, produces 12-HETE | Implicated in cancer and platelet function |
| ALOX15 | 15-lipoxygenase, produces 15-HETE and lipoxins | Role in resolution of inflammation and protectins |
| CYP2C8 | Cytochrome P450 epoxygenase, produces EETs | Vascular and inflammatory signaling |
| CYP2J2 | Cytochrome P450 epoxygenase, produces EETs | Cardiovascular and cancer biology |
| PTGIS | Prostacyclin synthase, produces prostacyclin | Vascular tone and platelet inhibition |
| TBXAS1 | Thromboxane synthase, produces thromboxane A2 | Platelet aggregation and thrombosis |
| HPGD | 15-hydroxyprostaglandin dehydrogenase, degrades prostaglandins | Catabolic control of prostaglandin levels |
| PTGES | Prostaglandin E synthase, produces PGE2 | Inflammation and cancer progression |
| PTGDS | Prostaglandin D synthase, produces PGD2 | Allergic and sleep regulation |
| ALOX5AP | 5-lipoxygenase activating protein | Leukotriene pathway regulation |
| LTC4S | Leukotriene C4 synthase | Cysteinyl leukotriene production |
| PLA2G2A | Secretory phospholipase A2 | Inflammatory eicosanoid release |
| EPHX2 | Soluble epoxide hydrolase, degrades EETs | Vascular and inflammatory regulation |
| PIK3CA | Oncogenic kinase that enhances arachidonic acid-derived eicosanoids | Links oncogenic signaling to eicosanoid metabolism |
How Is icosanoid metabolic process Regulated?
Icosanoid metabolic process is regulated at multiple levels, including substrate availability, enzyme expression, and post-translational modifications. Inflammatory stimuli induce PTGS2 and ALOX5 expression, while oncogenic PIK3CA signaling can reprogram arachidonic acid metabolism to enhance eicosanoid production. The pathway is also controlled by the balance between synthetic enzymes and catabolic enzymes such as HPGD, which terminates prostaglandin signaling. Specialized pro-resolving mediators are regulated by specific lipoxygenases and their subcellular localization, ensuring resolution of inflammation.
icosanoid metabolic process and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| PTGS2 | Inflammation and cancer | Knockout and overexpression cell lines |
| ALOX5 | Asthma and inflammatory diseases | Point-mutation models to alter catalytic activity |
| PIK3CA | Oncogenic metabolic reprogramming | Knock-in of mutant PIK3CA in cancer cells |
| HPGD | Prostaglandin degradation and cancer | Knockout to assess prostaglandin accumulation |
| ALOX15 | Resolution of inflammation and protectins | Overexpression for mediator production |
Icosanoids in infection and inflammation
The eicosanoid storm is a hallmark of severe infection and systemic inflammation, where massive release of prostaglandins and leukotrienes can drive fever, vasodilation, and tissue damage. Dysregulated icosanoid metabolism contributes to chronic inflammatory diseases, and targeting key enzymes such as PTGS2 and ALOX5 is a therapeutic strategy.
Icosanoids in tissue repair and skin wound healing
Icosanoids play dual roles in tissue repair, with some prostaglandins promoting early inflammation and others, such as lipoxins and protectins, facilitating resolution and wound closure. In skin wound healing, specific eicosanoids regulate keratinocyte migration and angiogenesis, making the pathway a target for regenerative medicine.
Icosanoids in preeclampsia
Preeclampsia is associated with altered eicosanoid metabolism, including imbalances in thromboxane and prostacyclin that affect placental blood flow and maternal vascular function. Research has focused on measuring eicosanoid profiles as biomarkers and on understanding how their dysregulation contributes to disease pathogenesis.
Icosanoids in prostate cancer and oncogenic signaling
Prostate cancer cells often exhibit enhanced arachidonic acid metabolism, leading to increased prostaglandin and leukotriene production that supports proliferation and survival. Oncogenic PIK3CA mutations further link phosphoinositide 3-kinase signaling to enhanced eicosanoid synthesis, revealing a metabolic vulnerability.
From icosanoid metabolic process-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of PTGS2 reduce prostaglandin production? | PTGS2 knockout cell line |
| Does a specific point mutation alter ALOX5 catalytic activity? | ALOX5 point-mutation knock-in |
| Can overexpression of ALOX15 enhance protectin synthesis? | ALOX15 overexpression cell model |
| Does mutant PIK3CA increase arachidonic acid-derived eicosanoids? | PIK3CA mutant knock-in |
| What is the role of HPGD in prostaglandin clearance? | HPGD knockout or knockdown |
| Can tagging endogenous COX-2 reveal its subcellular localization? | Tagged knock-in of PTGS2 |
How to Study the icosanoid metabolic process Process
| Method | What It Measures | Typical Application |
|---|---|---|
| LC-MS/MS lipidomics | Quantification of icosanoid species | Profiling prostaglandins and leukotrienes |
| RNA-seq | Expression of icosanoid enzymes | Pathway gene expression analysis |
| Western blot | Protein levels of COX-2, LOX, etc. | Validation of knockout or overexpression |
| Enzyme activity assay | Catalytic activity of COX/LOX | Functional validation of point mutants |
| CRISPR screen | Genes regulating eicosanoid levels | Discovery of novel pathway regulators |
| Immunofluorescence | Subcellular localization of enzymes | Tagged knock-in studies |
| Prostaglandin E2 ELISA | PGE2 concentration | Inflammation and cancer models |
| Beta-oxidation assay | Catabolism of eicosanoids | Studying mediator clearance |
Lipidomics and mass spectrometry
Mass spectrometry-based lipidomics is the primary method to quantify icosanoids in cells and tissues. It enables profiling of prostaglandins, leukotrienes, and specialized pro-resolving mediators, and has been used to link oncogenic PIK3CA to enhanced arachidonic acid-derived eicosanoids. This approach is essential for validating CRISPR models of icosanoid metabolic genes.
Transcriptomics and RNA-seq
RNA sequencing measures the expression of icosanoid biosynthetic and catabolic enzymes, providing a snapshot of pathway activity. It is often combined with lipidomics to correlate gene expression with mediator production in inflammatory or cancer models.
Enzyme activity assays
Enzymatic assays for cyclooxygenases, lipoxygenases, and cytochrome P450 epoxygenases measure the catalytic capacity of specific pathway enzymes. These assays are used to validate point mutations and to screen for inhibitors.
CRISPR screening and functional genomics
Genome-wide CRISPR screens can identify genes that regulate icosanoid production or mediate sensitivity to eicosanoid pathway inhibitors. Such screens have revealed metabolic dependencies in cancer and inflammation models.
How CRISPR Can Be Used to Study GO:0006690 icosanoid metabolic process
Knockout
CRISPR knockout of icosanoid pathway genes such as PTGS2, ALOX5, or HPGD allows researchers to determine their causal role in mediator production and disease phenotypes. Knockout cell lines are widely used to validate targets in inflammation and cancer.
Point Mutation
Point-mutation knock-in can mimic disease-associated variants or alter catalytic residues in enzymes like ALOX5 or PTGS2. These models help dissect the specific contribution of enzymatic activity versus scaffolding functions.
Knock-in
Knock-in of reporter tags or disease mutations, such as mutant PIK3CA, enables tracking of enzyme localization and signaling. This approach has been used to link oncogenic PIK3CA to enhanced eicosanoid synthesis.
Overexpression
Overexpression of biosynthetic enzymes like ALOX15 or PTGES can boost specific icosanoid production, facilitating studies of their biological effects. Overexpression models are valuable for testing whether a mediator is sufficient to drive a phenotype.
How EDITGENE Supports icosanoid metabolic process Research
Researchers studying icosanoid metabolic process-related genes often need to determine whether a candidate gene is causally involved in mediator production, inflammation, or cancer progression. EDITGENE provides a comprehensive suite of CRISPR services to generate precisely engineered cell models that answer these questions.
Contact EDITGENE today to design your custom CRISPR model for icosanoid metabolic process research.
Frequently Asked Questions About icosanoid metabolic process
What is icosanoid metabolic process?
Icosanoid metabolic process (GO:0006690) is the set of chemical reactions and pathways involving icosanoids, a group of C20 polyunsaturated fatty acids and their oxygenated derivatives.
What genes are involved in icosanoid metabolic process?
Key genes include PLA2G4A, PTGS1, PTGS2, ALOX5, ALOX12, ALOX15, CYP2C8, CYP2J2, PTGIS, TBXAS1, HPGD, PTGES, and PIK3CA.
What are icosanoids?
Icosanoids are C20 polyunsaturated fatty acid-derived lipid mediators, including prostaglandins, leukotrienes, thromboxanes, lipoxins, resolvins, and protectins.
How are icosanoids synthesized?
They are synthesized from arachidonic acid released from membranes, then oxygenated by cyclooxygenases, lipoxygenases, and cytochrome P450 enzymes.
What is the eicosanoid storm?
The eicosanoid storm is a massive release of icosanoids during severe infection or inflammation, which can amplify tissue damage and immune responses.
What diseases are linked to icosanoid metabolism?
Diseases include inflammatory disorders, preeclampsia, prostate cancer, and cancers with oncogenic PIK3CA mutations.
How are icosanoids degraded?
Icosanoids are degraded by beta-oxidation and other catabolic enzymes such as HPGD, which terminate their signaling.
What are specialized pro-resolving mediators?
They are icosanoids like resolvins and protectins that actively resolve inflammation and promote tissue repair.
How can CRISPR help study icosanoid metabolism?
CRISPR knockout, knock-in, point mutation, and overexpression models allow causal testing of icosanoid pathway genes in disease models.
What methods measure icosanoid levels?
LC-MS/MS lipidomics, ELISA, and enzyme activity assays are commonly used to quantify icosanoids and enzyme activity.
Conclusion
Icosanoid metabolic process (GO:0006690) is a fundamental biological pathway that produces potent lipid mediators controlling inflammation, immunity, tissue repair, and cancer progression. Its dysregulation is implicated in diverse diseases, from preeclampsia to prostate cancer, making it a rich area for therapeutic targeting. Advances in CRISPR gene editing and lipidomics now enable precise causal dissection of this pathway, accelerating the development of new treatments.
References
- 1. Dennis EA et al.. 2015. Eicosanoid storm in infection and inflammation.. Nat Rev Immunol 15(8):511-23 PMID: 26139350
- 2. Koundouros N et al.. 2020. Metabolic Fingerprinting Links Oncogenic PIK3CA with Enhanced Arachidonic Acid-Derived Eicosanoids.. Cell 181(7):1596-1611.e27 PMID: 32559461
- 3. Esser-von Bieren J. 2019. Eicosanoids in tissue repair.. Immunol Cell Biol 97(3):279-288 PMID: 30680784
- 4. Diczfalusy U. 1994. Beta-oxidation of eicosanoids.. Prog Lipid Res 33(4):403-28 PMID: 7870740
- 5. Yasukawa K et al.. 2020. Eicosanoids in Skin Wound Healing.. Int J Mol Sci 21(22) PMID: 33182690
- 6. Stenvik Haatveit Å et al.. 2023. The biosynthetic pathways of the protectins.. Prostaglandins Other Lipid Mediat 169:106787 PMID: 37806439
- 7. Walsh SW. 2004. Eicosanoids in preeclampsia.. Prostaglandins Leukot Essent Fatty Acids 70(2):223-32 PMID: 14683695
- 8. Panagiotopoulos AA et al.. 2018. Eicosanoids in prostate cancer.. Cancer Metastasis Rev 37(2-3):237-243 PMID: 30078159
