GO:0036102 leukotriene B4 metabolic process: Inflammatory Lipid Mediator Pathway, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0036102 (leukotriene B4 metabolic process) describes the chemical reactions and pathways involving leukotriene B4 (LTB4), a potent lipid mediator derived from arachidonic acid.
• LTB4 is synthesized from leukotriene A4 (LTA4) by LTA4 hydrolase and is released from activated human polymorphonuclear leukocytes.
• LTB4 is metabolized by omega-oxidation and beta-oxidation, with the liver playing a major role in its uptake and metabolic disposition.
• LTB4 metabolism is relevant to inflammatory diseases, including myocardial infarction and non-alcoholic fatty liver disease (NAFLD).
• Neutrophil interactions with bacteria such as Salmonella typhimurium can modulate leukotriene synthesis and LTB4 omega-hydroxylation.
• Key enzymes in LTB4 metabolism include ALOX5, LTA4H, CYP4F3, and PTGR1, which are targets for CRISPR-based functional studies.
Description
Leukotriene B4 (LTB4) is a potent lipid mediator of inflammation that is derived from arachidonic acid through the 5-lipoxygenase pathway. The Gene Ontology term GO:0036102, leukotriene B4 metabolic process, encompasses the chemical reactions and pathways involving LTB4, including its synthesis, conversion, and degradation. This process is critical for understanding how inflammatory responses are initiated and resolved, and it has been implicated in a wide range of human diseases, from cardiovascular disorders to metabolic liver disease. Researchers studying inflammation, lipid signaling, and immune cell function require a detailed understanding of LTB4 metabolism to identify therapeutic targets and biomarkers. The pathway is highly regulated and involves multiple enzymes, transporters, and receptors that can be interrogated using modern genetic and biochemical tools.
leukotriene B4 metabolic process At A Glance
| GO ID | GO:0036102 |
|---|---|
| GO term | leukotriene B4 metabolic process |
| Ontology | biological_process |
| Synonym | LTB4 metabolism |
| Definition | The chemical reactions and pathways involving leukotriene B4, a leukotriene composed of (6Z,8E,10E,14Z)-eicosatetraenoic acid having (5S)- and (12R)-hydroxy substituents. |
| Major function | Synthesis, conversion, and degradation of leukotriene B4, a potent inflammatory lipid mediator. |
| Key enzymes | ALOX5, ALOX5AP, LTA4H, CYP4F3, PTGR1 |
| Subcellular location | Cytosol, endoplasmic reticulum, and extracellular space |
| Related pathways | Arachidonic acid metabolism, inflammatory response, neutrophil chemotaxis |
What Is GO:0036102?
According to the Gene Ontology, GO:0036102 (leukotriene B4 metabolic process) is defined as the chemical reactions and pathways involving leukotriene B4, a leukotriene composed of (6Z,8E,10E,14Z)-eicosatetraenoic acid having (5S)- and (12R)-hydroxy substituents. In simpler terms, it is the set of biochemical steps by which cells produce, modify, and break down LTB4, a key signaling molecule in inflammation.
Why Is leukotriene B4 metabolic process Important in Cell Biology?
LTB4 metabolic process is important because LTB4 is one of the most potent chemotactic agents for neutrophils and plays a central role in acute and chronic inflammation. Dysregulation of LTB4 synthesis or degradation contributes to the pathogenesis of inflammatory diseases, including myocardial infarction, non-alcoholic fatty liver disease, and bacterial infections. Understanding the enzymes and regulatory mechanisms involved in LTB4 metabolism can reveal new therapeutic targets and help researchers design experiments to modulate inflammatory responses.
• LTB4 is a key mediator of neutrophil recruitment and activation during inflammation.
• The balance between LTB4 synthesis and degradation determines the intensity and duration of inflammatory responses.
• Hepatic uptake and metabolism of LTB4 are critical for clearing this mediator from circulation.
• LTB4 metabolism is implicated in cardiovascular diseases such as myocardial infarction.
• Dysregulated LTB4 signaling contributes to non-alcoholic fatty liver disease (NAFLD) in obesity.
• Bacterial pathogens can manipulate neutrophil LTB4 synthesis and omega-hydroxylation.
• Enzymes like LTA4H and CYP4F3 are potential drug targets for anti-inflammatory therapies.
• Studying LTB4 metabolism helps explain inter-individual differences in inflammatory disease susceptibility.
• CRISPR-based models enable precise dissection of LTB4 metabolic gene functions.
• LTB4 metabolic pathways are conserved across species, facilitating translational research.
What Happens During leukotriene B4 metabolic process?
Synthesis of leukotriene B4 from arachidonic acid
In simple terms: Cells convert a common fat molecule into an inflammatory signal called LTB4.
LTB4 is synthesized from arachidonic acid through the action of 5-lipoxygenase (ALOX5) and 5-lipoxygenase-activating protein (ALOX5AP), which together convert arachidonic acid to leukotriene A4 (LTA4). LTA4 is then converted to LTB4 by LTA4 hydrolase (LTA4H). This step is critical because LTB4 is the major leukotriene released by activated human polymorphonuclear leukocytes. The synthesis process is tightly regulated and occurs primarily in myeloid cells such as neutrophils and macrophages.
Release and extracellular signaling
In simple terms: Once made, LTB4 leaves the cell to attract immune cells to sites of injury or infection.
After synthesis, LTB4 is released from cells into the extracellular space, where it acts as a chemoattractant for neutrophils and other immune cells. The release of LTB4 versus its precursor LTA4 from human polymorphonuclear leukocytes has been characterized, showing that LTB4 is the predominant product under most conditions. This extracellular signaling is essential for mounting an effective inflammatory response.
Omega-oxidation and inactivation
In simple terms: The body inactivates LTB4 by adding oxygen atoms to it, making it less active.
LTB4 is inactivated primarily through omega-oxidation, catalyzed by cytochrome P450 enzymes such as CYP4F3, which converts LTB4 to 20-hydroxy-LTB4 and further metabolites. This process is important for terminating the inflammatory signal. Neutrophil interactions with bacteria like Salmonella typhimurium can modulate omega-hydroxylation of LTB4, affecting the resolution of inflammation.
Beta-oxidation and chain shortening
In simple terms: After omega-oxidation, the molecule is further broken down by removing carbon units.
Following omega-oxidation, LTB4 metabolites undergo beta-oxidation, leading to chain shortening and eventual excretion. This step is part of the complete catabolic pathway that clears LTB4 from the body. The liver plays a major role in the uptake and metabolic disposition of LTB4, as shown in rat studies.
Hepatic uptake and clearance
In simple terms: The liver removes LTB4 from the blood and processes it for elimination.
The liver is a key organ for LTB4 clearance. Studies in rats have demonstrated that the liver takes up LTB4 and metabolizes it through omega- and beta-oxidation pathways. This hepatic clearance is essential for maintaining systemic levels of LTB4 and preventing excessive inflammation. Hepatocyte LTB4 receptor 1 (BLT1) has been shown to promote NAFLD development in obesity, linking hepatic LTB4 metabolism to metabolic disease.
Key Genes Involved in GO:0036102 leukotriene B4 metabolic process
The following genes encode enzymes, receptors, and transporters that are directly involved in leukotriene B4 metabolic process.
| Gene | Major Role | Research Relevance |
|---|---|---|
| ALOX5 | Converts arachidonic acid to 5-HPETE and then to LTA4 | Rate-limiting enzyme in LTB4 synthesis; target for anti-inflammatory drugs |
| ALOX5AP | Activates ALOX5 and facilitates LTA4 production | Essential for LTB4 synthesis; genetic variants linked to inflammatory diseases |
| LTA4H | Converts LTA4 to LTB4 | Key enzyme for LTB4 production; target for inhibitors |
| CYP4F3 | Omega-hydroxylates LTB4 to 20-hydroxy-LTB4 | Major inactivation enzyme; regulates LTB4 levels |
| PTGR1 | Reduces LTB4 to 12-oxo-LTB4 and further metabolites | Involved in LTB4 catabolism |
| BLT1 (LTB4R) | High-affinity receptor for LTB4 | Mediates chemotaxis and inflammatory signaling |
| BLT2 (LTB4R2) | Low-affinity receptor for LTB4 | Modulates inflammatory responses |
| PLA2G4A | Releases arachidonic acid from membrane phospholipids | Upstream of LTB4 synthesis |
| PTGS1/PTGS2 | Prostaglandin-endoperoxide synthases; can influence arachidonic acid availability | Cross-talk with LTB4 pathway |
| ABCC1 | Transports LTB4 and its metabolites | Affects LTB4 export and clearance |
| SLC22A8 | Organic anion transporter involved in LTB4 uptake | Hepatic clearance |
| CYP4F2 | Omega-hydroxylase for LTB4 | Alternative inactivation pathway |
| CYP4F22 | Omega-hydroxylase for LTB4 | Skin-specific LTB4 metabolism |
| GGT1 | Gamma-glutamyl transpeptidase; may process LTB4 metabolites | Indirect role in LTB4 metabolism |
| DPEP1 | Dipeptidase; may inactivate LTB4 metabolites | Potential role in LTB4 catabolism |
| ALOX15 | 15-lipoxygenase; can modulate LTB4 synthesis | Cross-talk with other lipid mediators |
| LTC4S | Converts LTA4 to LTC4 | Competes with LTA4H for LTA4 |
| MGST2 | Microsomal glutathione S-transferase; involved in LTC4 synthesis | Indirect regulation of LTB4 production |
How Is leukotriene B4 metabolic process Regulated?
LTB4 metabolic process is regulated at multiple levels. The synthesis of LTB4 is controlled by the availability of arachidonic acid, the activity of ALOX5 and ALOX5AP, and the expression of LTA4H. Inactivation is regulated by the expression and activity of omega-hydroxylases such as CYP4F3, which can be induced by inflammatory stimuli. Hepatic uptake and clearance are mediated by transporters and receptors, including BLT1 on hepatocytes. Additionally, bacterial interactions can modulate neutrophil LTB4 synthesis and omega-hydroxylation, as shown with Salmonella typhimurium. These regulatory mechanisms ensure that LTB4 levels are tightly controlled to prevent excessive inflammation.
leukotriene B4 metabolic process and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| ALOX5 | Inflammatory diseases, asthma | Knockout mice, point mutation cell lines |
| LTA4H | Cardiovascular disease, inflammation | Knock-in mice, overexpression cell models |
| CYP4F3 | Inflammatory resolution, infection | Knockout cell lines, CRISPR point mutations |
| BLT1 (LTB4R) | NAFLD, obesity | Hepatocyte-specific knockout mice |
| PTGR1 | Metabolic disorders | Overexpression and knockout cell models |
Leukotriene B4 metabolism in cardiovascular disease
LTB4 is a potent mediator of inflammation that contributes to myocardial infarction. A recent study showed that arachidonic acid fuels inflammation by unlocking macrophage protein phosphatase 5 after myocardial infarction, implicating LTB4 metabolic pathways in cardiac injury and repair. Targeting LTB4 synthesis or signaling may offer therapeutic benefits in cardiovascular disease.
Leukotriene B4 metabolism in non-alcoholic fatty liver disease (NAFLD)
Hepatocyte leukotriene B4 receptor 1 (BLT1) promotes NAFLD development in obesity. This suggests that LTB4 signaling in the liver contributes to lipid accumulation and inflammation. Modulating LTB4 metabolism could be a strategy for treating NAFLD.
Leukotriene B4 metabolism in bacterial infections
Neutrophil interactions with Salmonella typhimurium can manipulate LTB4 synthesis and omega-hydroxylation, affecting neutrophil swarming and bacterial clearance. This highlights the role of LTB4 metabolism in host-pathogen interactions and the potential for bacteria to evade immune responses by altering LTB4 levels.
From leukotriene B4 metabolic process-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does ALOX5 knockout reduce LTB4 synthesis? | ALOX5 knockout cell line (e.g., HL-60 or primary neutrophils) |
| Does LTA4H point mutation affect LTB4 production? | CRISPR point mutation knock-in in HEK293 or neutrophil-like cells |
| Does CYP4F3 overexpression enhance LTB4 inactivation? | CYP4F3 overexpression cell model |
| Does BLT1 knockout protect against NAFLD? | Hepatocyte-specific BLT1 knockout mice |
| Does PTGR1 knockout alter LTB4 metabolite profile? | PTGR1 knockout cell line followed by LC-MS/MS |
| Does Salmonella infection modulate LTB4 omega-hydroxylation? | Co-culture of neutrophils with Salmonella typhimurium |
How to Study the leukotriene B4 metabolic process Process
| Method | What It Measures | Typical Application |
|---|---|---|
| LC-MS/MS | LTB4 and metabolite levels | Quantification in cell culture and tissues |
| Enzyme activity assay | Conversion of LTA4 to LTB4 or LTB4 to 20-OH-LTB4 | Kinetic studies and inhibitor screening |
| CRISPR knockout | Loss-of-function effects on LTB4 metabolism | Target validation |
| CRISPR point mutation | Specific amino acid changes in metabolic enzymes | Structure-function studies |
| CRISPR knock-in | Tagged or reporter alleles | Live-cell imaging of LTB4 dynamics |
| Overexpression | Gain-of-function effects | Enzyme overproduction and pathway flux |
| Neutrophil chemotaxis | Cell migration in response to LTB4 | Inflammation and infection studies |
| RNA-seq | Transcriptional changes in LTB4 metabolic genes | Pathway regulation analysis |
LC-MS/MS for LTB4 and metabolite quantification
Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is the gold standard for measuring LTB4 and its metabolites in biological samples. This method allows precise quantification of LTB4, 20-hydroxy-LTB4, and other oxidation products, enabling researchers to assess the activity of metabolic enzymes.
Enzyme activity assays
Enzyme activity assays using recombinant LTA4H, CYP4F3, or PTGR1 can measure the conversion of substrates to products. These assays are useful for screening inhibitors and studying kinetic parameters of LTB4 metabolic enzymes.
CRISPR-based gene editing
CRISPR-Cas9 knockout, point mutation, and knock-in models allow researchers to dissect the specific roles of genes in LTB4 metabolism. For example, knockout of ALOX5 or LTA4H can confirm their essential roles in LTB4 synthesis.
Neutrophil functional assays
Neutrophil chemotaxis and swarming assays can measure the biological effects of LTB4 and its metabolites. These assays are particularly useful for studying host-pathogen interactions and the impact of LTB4 metabolism on immune cell recruitment.
How CRISPR Can Be Used to Study GO:0036102 leukotriene B4 metabolic process
Knockout
CRISPR knockout of genes such as ALOX5, LTA4H, or CYP4F3 can abolish or drastically reduce LTB4 synthesis or degradation, providing causal evidence for their roles. Knockout cell lines and mice are valuable for studying the impact of LTB4 metabolism on inflammation and disease.
Point Mutation
CRISPR point mutations can introduce specific amino acid substitutions in enzymes like LTA4H or CYP4F3 to study catalytic mechanisms and substrate specificity. These models are useful for understanding how genetic variants affect LTB4 metabolism.
Knock-in
Knock-in of tagged or reporter alleles (e.g., GFP-LTA4H) allows real-time visualization of enzyme localization and dynamics in living cells. This approach can reveal spatiotemporal regulation of LTB4 metabolism.
Overexpression
Overexpression of LTB4 metabolic enzymes such as CYP4F3 or PTGR1 can enhance LTB4 inactivation and reduce inflammatory responses. Overexpression models are useful for gain-of-function studies and for testing therapeutic strategies.
How EDITGENE Supports leukotriene B4 metabolic process Research
Researchers studying leukotriene B4 metabolic process-related genes often need to determine whether a candidate gene is causally involved in LTB4 synthesis, degradation, or signaling. EDITGENE provides a comprehensive suite of CRISPR-based services to accelerate this research, from knockout and point mutation to knock-in and overexpression models, as well as library screening and bioinformatics support.
Contact EDITGENE today to design your custom CRISPR model for leukotriene B4 metabolic process research.
Frequently Asked Questions About leukotriene B4 metabolic process
What is leukotriene B4 metabolic process?
It is the set of biochemical reactions that produce, modify, and degrade leukotriene B4 (LTB4), a potent inflammatory lipid mediator.
What genes are involved in leukotriene B4 metabolic process?
Key genes include ALOX5, ALOX5AP, LTA4H, CYP4F3, PTGR1, and BLT1 (LTB4R).
How is leukotriene B4 synthesized?
LTB4 is synthesized from arachidonic acid via 5-lipoxygenase (ALOX5) and LTA4 hydrolase (LTA4H).
How is leukotriene B4 inactivated?
LTB4 is inactivated by omega-oxidation, primarily via CYP4F3, followed by beta-oxidation.
What diseases are associated with leukotriene B4 metabolism?
It is linked to cardiovascular disease, NAFLD, and bacterial infections.
What is the role of the liver in leukotriene B4 metabolism?
The liver takes up and metabolizes LTB4, contributing to its clearance from circulation.
Can CRISPR be used to study leukotriene B4 metabolism?
Yes, CRISPR knockout, point mutation, and knock-in models are powerful tools for dissecting gene function in this pathway.
What methods measure leukotriene B4 levels?
LC-MS/MS is the most sensitive and specific method for quantifying LTB4 and its metabolites.
What is the GO ID for leukotriene B4 metabolic process?
The GO ID is GO:0036102.
Why is leukotriene B4 metabolism important for inflammation?
LTB4 is a potent chemoattractant for neutrophils, and its metabolism controls the duration and intensity of inflammatory responses.
Conclusion
Leukotriene B4 metabolic process (GO:0036102) is a critical biological pathway that governs the synthesis, signaling, and degradation of a key inflammatory mediator. Understanding its enzymes and regulatory mechanisms provides insights into diseases such as myocardial infarction, NAFLD, and bacterial infections. CRISPR-based models and advanced analytical methods are essential for dissecting this pathway and developing new therapeutic strategies. EDITGENE offers comprehensive services to support research on LTB4 metabolism and related genes.
References
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- 3. Hammarström S et al.. 1985. Metabolism of leukotrienes.. Mol Cell Biochem 69(1):7-16 PMID: 3001504
- 4. Hagmann W et al.. 1990. Hepatic uptake and metabolic disposition of leukotriene B4 in rats.. Biochem J 267(2):467-70 PMID: 2159284
- 6. Sala A et al.. 1996. Release of leukotriene A4 versus leukotriene B4 from human polymorphonuclear leukocytes.. J Biol Chem 271(30):17944-8 PMID: 8663438
- 7. Golenkina EA et al.. 2025. Sulfur compounds navigate redox processes, leukotriene synthesis, and ω-hydroxylation of leukotriene B4 in neutrophil interaction with the bacteria Salmonella typhimurium: the way to manipulate neutrophil swarming.. Front Immunol 16:1606408 PMID: 41169377
- 8. Liu X et al.. 2023. Hepatocyte leukotriene B4 receptor 1 promotes NAFLD development in obesity.. Hepatology 78(2):562-577 PMID: 35931467
