GO:0031665 negative regulation of lipopolysaccharide-mediated signaling pathway: Mechanism, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0031665 describes any process that stops, prevents, or reduces signaling triggered by lipopolysaccharide (LPS) detection.
• Negative regulators such as MKP-1 (DUSP1) directly dephosphorylate JNK to dampen LPS-induced inflammatory signaling in macrophages.
• Adaptor proteins like LAB and Rho-GDIα modulate LPS responses through tyrosine phosphorylation-independent and cytoskeletal mechanisms, respectively.
• Pellino proteins differentially regulate TLR2-mediated signaling induced by Helicobacter pylori LPS, showing pathogen-specific control.
• Dysregulation of this pathway contributes to sepsis, atherosclerosis, and renal injury, making it a therapeutic target.
• CRISPR knockout, knock-in, and overexpression models are essential to dissect causal roles of negative regulators in LPS signaling.
Description
The lipopolysaccharide (LPS)-mediated signaling pathway is a critical arm of innate immunity that detects Gram-negative bacterial infections and triggers inflammatory responses. However, uncontrolled activation of this pathway can lead to tissue damage and chronic inflammatory diseases. GO:0031665, negative regulation of lipopolysaccharide-mediated signaling pathway, encompasses the cellular processes that restrain or terminate LPS-induced signals. Understanding these negative regulatory mechanisms is vital for developing therapies against sepsis, atherosclerosis, and other inflammatory conditions. This article synthesizes authoritative QuickGO data and verified PubMed literature to provide a research-grade overview of the genes, mechanisms, and experimental models central to GO:0031665.
negative regulation of lipopolysaccharide-mediated signaling pathway At A Glance
| GO ID | GO:0031665 |
|---|---|
| GO term | negative regulation of lipopolysaccharide-mediated signaling pathway |
| Ontology | biological_process |
| Synonym | down regulation of lipopolysaccharide-mediated signaling pathway; inhibition of lipopolysaccharide-mediated signaling pathway; negative regulation of LPS-mediated signaling pathway |
| Major function | Dampening or terminating LPS-induced inflammatory signaling to prevent excessive immune activation |
| Key negative regulators | DUSP1 (MKP-1), LAB, Rho-GDIα, Pellino proteins, miR-410-5p |
| Associated diseases | Sepsis, atherosclerosis, renal injury, fetal-maternal immunotolerance disorders |
| Research methods | CRISPR knockout/knock-in, RNA-seq, proteomics, phospho-specific flow cytometry |
What Is GO:0031665?
GO:0031665 refers to any biological process that stops, prevents, or reduces the frequency, rate, or extent of signaling in response to detection of lipopolysaccharide (LPS). It includes mechanisms that downregulate or inhibit the LPS-mediated signaling cascade, such as phosphatases, adaptor proteins, and microRNAs that target key signaling intermediates.
Why Is negative regulation of lipopolysaccharide-mediated signaling pathway Important in Cell Biology?
Negative regulation of LPS-mediated signaling is essential to prevent runaway inflammation while maintaining effective pathogen clearance. Dysregulation of this process is implicated in sepsis, chronic inflammatory diseases, and autoimmune disorders, making it a high-priority target for therapeutic intervention.
• Prevents septic shock by limiting excessive cytokine production in response to LPS.
• Modulates atherosclerosis progression by controlling inflammatory responses in plaques.
• Protects against renal injury by dampening LPS-induced podocyte damage.
• Regulates fetal-maternal immunotolerance through miR-410-5p targeting of STAT1.
• Controls Helicobacter pylori-induced inflammation via Pellino proteins.
• Influences neuroinflammation by regulating iNOS expression through ceramide.
• Provides targets for anti-inflammatory drug development, such as RhuDex.
• Helps maintain immune homeostasis and prevent autoimmunity.
• Critical for understanding host-pathogen interactions and bacterial evasion strategies.
• Enables precision medicine approaches by identifying patient-specific regulatory defects.
What Happens During negative regulation of lipopolysaccharide-mediated signaling pathway?
Initiation of LPS Detection and Early Negative Feedback
In simple terms: When LPS is detected, the cell quickly starts putting brakes on the alarm to avoid overreaction.
LPS binding to TLR4 triggers a signaling cascade that activates NF-κB and MAP kinases. Negative regulation begins with early feedback mechanisms, including the induction of phosphatases like MKP-1 (DUSP1), which dephosphorylate and inactivate JNK, thereby reducing inflammatory gene expression. Additionally, adaptor proteins such as LAB can modulate LPS responses independently of tyrosine phosphorylation, fine-tuning the signal strength.
Phosphatase-Mediated Inactivation of MAP Kinases
In simple terms: Enzymes called phosphatases remove phosphate groups from signaling proteins to turn them off.
MKP-1 is a critical negative regulator that specifically dephosphorylates JNK in macrophages, limiting LPS-induced c-Jun N-terminal kinase activation. This phosphatase activity is essential for preventing prolonged inflammatory signaling and is a key node in GO:0031665.
Regulation by MicroRNAs and Adaptor Proteins
In simple terms: Small RNA molecules and adaptor proteins can block or dampen the LPS signal.
MicroRNAs such as miR-410-5p target STAT1 signaling to induce M2 macrophage polarization and immunotolerance, indirectly negatively regulating LPS-mediated pathways. Adaptor proteins like LAB and Rho-GDIα also play roles; Rho-GDIα loss sensitizes podocytes to LPS injury, indicating its protective function in negative regulation.
Pathogen-Specific Modulation by Pellino Proteins
In simple terms: Different bacteria can tweak the brakes on LPS signaling in unique ways.
Pellino proteins differentially modulate TLR2 signaling induced by Helicobacter pylori LPS, demonstrating that negative regulation can be pathogen-specific and involve E3 ubiquitin ligase-like activities. This adds a layer of complexity to GO:0031665, where host factors interact with bacterial components to shape the inflammatory outcome.
Key Genes Involved in GO:0031665 negative regulation of lipopolysaccharide-mediated signaling pathway
The following genes and proteins are experimentally validated participants in the negative regulation of LPS-mediated signaling.
| Gene | Major Role | Research Relevance |
|---|---|---|
| DUSP1 (MKP-1) | Dephosphorylates JNK to terminate LPS-induced MAPK signaling | Knockout mice show prolonged inflammation; target for anti-inflammatory drugs |
| LAB (LAT2) | Transmembrane adaptor that modulates LPS responses independently of tyrosine phosphorylation | Regulates B cell and macrophage signaling; potential autoimmune target |
| ARHGDIA (Rho-GDIα) | Protects podocytes from LPS-induced injury by regulating Rho GTPases | Loss sensitizes to renal injury; model for kidney inflammation |
| PELI1/2/3 | Differential modulation of TLR2 signaling by H. pylori LPS | Pathogen-specific regulation; targets for gastric inflammation |
| STAT1 | Target of miR-410-5p; negatively regulates M2 polarization | Role in fetal-maternal immunotolerance; cancer immunotherapy target |
| SMPD1 (nSMase) | Produces ceramide involved in LPS-mediated iNOS expression | Neuroinflammation model; target for neurodegenerative diseases |
| CD80 (B7-1) | Inhibited by RhuDex to reduce LPS-mediated inflammation | Atherosclerosis and autoimmune disease target |
| NFKB1 | Central transcription factor in LPS signaling; negative regulators act upstream | Broad inflammatory diseases; drug target |
| MAPK8 (JNK1) | Substrate of MKP-1; mediates LPS-induced apoptosis | Sepsis and neuroinflammation models |
| TLR4 | Primary receptor for LPS; negative regulators modulate its signaling | Sepsis and atherosclerosis models |
| MYD88 | Adaptor in TLR4 signaling; negative regulators interfere | Innate immunity studies |
| TICAM1 (TRIF) | Alternative adaptor; negative regulation less characterized | Viral and bacterial infection models |
| IRAK1 | Kinase in LPS signaling; targeted by negative regulators | Inflammatory disease models |
| TRAF6 | E3 ligase in LPS signaling; modulated by Pellino proteins | Cancer and inflammation |
| miR-410-5p | Targets STAT1 to induce M2 polarization | Fetal-maternal interface research |
| RIPK1 | Regulates NF-κB and cell death in LPS responses | Sepsis and IBD models |
| TNFAIP3 (A20) | Ubiquitin-editing enzyme that terminates LPS signaling | Autoimmunity and lymphoma |
| SOCS1 | Suppressor of cytokine signaling; inhibits LPS-induced pathways | Sepsis and cancer |
How Is negative regulation of lipopolysaccharide-mediated signaling pathway Regulated?
The negative regulation of LPS-mediated signaling is itself tightly regulated. MKP-1 expression is induced by LPS via NF-κB, creating a negative feedback loop. MicroRNAs such as miR-410-5p can post-transcriptionally suppress STAT1, adding another layer of control. Additionally, Pellino proteins are regulated by phosphorylation and ubiquitination, affecting their ability to modulate TLR signaling.
negative regulation of lipopolysaccharide-mediated signaling pathway and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| DUSP1 | Sepsis, inflammation | Knockout mice, macrophage cell lines |
| CD80 | Atherosclerosis | Human atherosclerotic plaque explants, ApoE-/- mice |
| ARHGDIA | Renal injury | Podocyte-specific knockout mice |
| STAT1 | Fetal-maternal immunotolerance | Trophoblast cell lines, miR-410-5p mimics |
| PELI1 | Gastric inflammation | H. pylori infection models, TLR2 reporter cells |
Sepsis and Systemic Inflammation
Impaired negative regulation of LPS signaling leads to excessive cytokine release and septic shock. Dachengqi Decoction has been shown to alleviate sepsis by modulating LPS-mediated pathways, highlighting the therapeutic potential of targeting GO:0031665. MKP-1 deficiency exacerbates LPS-induced JNK activation, contributing to organ damage.
Atherosclerosis
Chronic LPS exposure promotes atherosclerotic plaque inflammation. Inhibition of CD80 by RhuDex reduces LPS-mediated inflammation in human atherosclerotic lesions, demonstrating that negative regulators can be therapeutically exploited.
Renal Injury
Loss of Rho-GDIα sensitizes podocytes to LPS-mediated injury, linking negative regulation to kidney disease progression. This suggests that enhancing Rho-GDIα activity could protect against renal inflammation.
Fetal-Maternal Immunotolerance
Trophoblast-derived miR-410-5p induces M2 macrophage polarization by targeting STAT1, thereby contributing to immunotolerance at the fetal-maternal interface. This represents a specialized role of negative regulation in reproductive biology.
From negative regulation of lipopolysaccharide-mediated signaling pathway-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does DUSP1 knockout enhance LPS-induced JNK activation? | DUSP1 knockout macrophages |
| Can point mutation in LAB alter LPS response? | LAB point-mutant knock-in mice |
| Does Rho-GDIα overexpression protect podocytes from LPS? | Rho-GDIα overexpression in podocyte cell lines |
| What is the effect of miR-410-5p on STAT1 signaling? | miR-410-5p mimic/inhibitor in trophoblasts |
| Can CRISPR knock-in of tagged MKP-1 reveal its interactome? | Tagged knock-in HEK293T cells |
| Does Pellino knockout affect H. pylori LPS signaling? | Pellino KO macrophages |
How to Study the negative regulation of lipopolysaccharide-mediated signaling pathway Process
| Method | What It Measures | Typical Application |
|---|---|---|
| RNA-seq | Global gene expression changes | Identify LPS-induced genes in KO cells |
| Phosphoproteomics | Phosphorylation of signaling proteins | Quantify JNK/STAT1 phosphorylation |
| CRISPR screen | Genes whose loss alters LPS response | Discover novel negative regulators |
| Flow cytometry | Single-cell protein phosphorylation | Measure p-JNK in macrophages |
| Western blot | Protein levels and phosphorylation | Validate MKP-1 expression |
| ELISA | Cytokine secretion | Measure TNF-α and IL-6 after LPS |
| Luciferase reporter | NF-κB transcriptional activity | Screen for regulators |
| Co-IP | Protein-protein interactions | Identify MKP-1 substrates |
Transcriptomic Profiling
RNA-seq can identify global changes in gene expression upon LPS stimulation in cells with CRISPR knockout of negative regulators, revealing pathways controlled by GO:0031665.
Phosphoproteomics
Mass spectrometry-based phosphoproteomics quantifies changes in phosphorylation of signaling intermediates like JNK and STAT1, directly measuring the impact of negative regulators.
CRISPR Screening
Genome-wide CRISPR knockout screens can identify novel negative regulators of LPS signaling by selecting for cells with enhanced NF-κB activation upon LPS treatment.
Imaging and Flow Cytometry
Phospho-specific flow cytometry and live-cell imaging allow single-cell analysis of LPS signaling dynamics and the effect of negative regulators on NF-κB translocation.
How CRISPR Can Be Used to Study GO:0031665 negative regulation of lipopolysaccharide-mediated signaling pathway
Knockout
CRISPR knockout of DUSP1 or other negative regulators in macrophage cell lines can confirm their role in dampening LPS-induced JNK activation, as shown by prolonged phosphorylation.
Point Mutation
Introducing point mutations in the catalytic domain of MKP-1 can dissect phosphatase-dependent versus independent functions in LPS signaling.
Knock-in
Knock-in of epitope tags (e.g., FLAG) into endogenous DUSP1 allows for proteomic identification of interacting partners during LPS stimulation.
Overexpression
Overexpression of Rho-GDIα in podocytes can protect against LPS-induced injury, validating its negative regulatory role.
How EDITGENE Supports negative regulation of lipopolysaccharide-mediated signaling pathway Research
Researchers studying negative regulation of lipopolysaccharide-mediated signaling pathway-related genes often need to determine whether a candidate gene is causally involved in dampening LPS responses. EDITGENE provides comprehensive CRISPR-based services to accelerate this discovery.
Contact EDITGENE today to design your custom CRISPR model for negative regulation of lipopolysaccharide-mediated signaling pathway research.
Frequently Asked Questions About negative regulation of lipopolysaccharide-mediated signaling pathway
What is GO:0031665?
GO:0031665 is the Gene Ontology term for negative regulation of lipopolysaccharide-mediated signaling pathway, describing processes that stop or reduce LPS-induced signaling.
What genes are involved in negative regulation of LPS signaling?
Key genes include DUSP1 (MKP-1), LAB, Rho-GDIα, Pellino proteins, and miR-410-5p, among others.
How does MKP-1 negatively regulate LPS signaling?
MKP-1 dephosphorylates JNK, thereby inactivating it and reducing LPS-induced inflammatory gene expression.
What diseases are associated with defective negative regulation of LPS signaling?
Sepsis, atherosclerosis, renal injury, and fetal-maternal immunotolerance disorders are linked to dysregulation of this pathway.
What experimental models are used to study GO:0031665?
CRISPR knockout mice, macrophage cell lines, and podocyte models are commonly used.
How can CRISPR screening identify new negative regulators?
Genome-wide knockout screens can select for cells with enhanced NF-κB activation upon LPS, revealing novel regulators.
What is the role of Pellino proteins in LPS signaling?
Pellino proteins differentially modulate TLR2 signaling induced by H. pylori LPS, affecting inflammatory outcomes.
Can miR-410-5p regulate LPS-mediated signaling?
Yes, miR-410-5p targets STAT1 to induce M2 macrophage polarization and immunotolerance, indirectly negatively regulating LPS pathways.
What is the impact of Rho-GDIα on LPS-induced renal injury?
Loss of Rho-GDIα sensitizes podocytes to LPS-mediated injury, indicating its protective role.
How does RhuDex reduce LPS-mediated inflammation?
RhuDex inhibits CD80 (B7-1), leading to reduced LPS-mediated inflammation in atherosclerotic lesions.
Conclusion
GO:0031665 encompasses critical mechanisms that restrain LPS-mediated signaling to prevent inflammatory damage. Key regulators such as MKP-1, LAB, Rho-GDIα, and microRNAs like miR-410-5p have been validated in diverse experimental models. Dysregulation of these pathways contributes to sepsis, atherosclerosis, and renal injury, highlighting their therapeutic potential. CRISPR-based models and multi-omics approaches are indispensable for dissecting these complex networks and identifying new drug targets.
References
- 1. Smith SM et al.. 2017. Differential modulation of Helicobacter pylori lipopolysaccharide-mediated TLR2 signaling by individual Pellino proteins.. Helicobacter 22(1) PMID: 27302665
- 2. Zhu M et al.. 2012. Tyrosine phosphorylation-independent regulation of lipopolysaccharide-mediated response by the transmembrane adaptor protein LAB.. J Immunol 188(6):2733-41 PMID: 22308309
- 3. Robins R et al.. 2015. Loss of Rho-GDIα sensitizes podocytes to lipopolysaccharide-mediated injury.. Am J Physiol Renal Physiol 308(11):F1207-16 PMID: 25503727
- 4. Won JS et al.. 2004. The role of neutral sphingomyelinase produced ceramide in lipopolysaccharide-mediated expression of inducible nitric oxide synthase.. J Neurochem 88(3):583-93 PMID: 14720208
- 5. Doesch AO et al.. 2014. Inhibition of B7-1 (CD80) by RhuDex® reduces lipopolysaccharide-mediated inflammation in human atherosclerotic lesions.. Drug Des Devel Ther 8:447-57 PMID: 24872677
- 6. Matsuguchi T et al.. 2001. A novel mitogen-activated protein kinase phosphatase is an important negative regulator of lipopolysaccharide-mediated c-Jun N-terminal kinase activation in mouse macrophage cell lines.. Mol Cell Biol 21(20):6999-7009 PMID: 11564882
- 7. Yang J et al.. 2024. Trophoblast-derived miR-410-5p induces M2 macrophage polarization and mediates immunotolerance at the fetal-maternal interface by targeting the STAT1 signaling pathway.. J Transl Med 22(1):19 PMID: 38178171
- 8. Fu ZH et al.. 2021. [Mechanism and experimental verification of Dachengqi Decoction in treatment of sepsis based on network pharmacology].. Zhongguo Zhong Yao Za Zhi 46(20):5351-5361 PMID: 34738439
