GO:0038148 chemokine (C-C motif) ligand 2 signaling pathway: Inflammatory Axis, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0038148 describes the molecular signaling cascade initiated when CCL2 binds its receptor CCR2 on target cells, culminating in downstream cellular responses such as transcription.
• The CCL2-CCR2 axis is a central driver of monocyte/macrophage recruitment and is implicated in chronic inflammatory diseases including COPD, atherosclerosis, and cancer.
• CCL2 signaling activates multiple intracellular pathways, including PI3K-AKT, ERK, and STAT3, depending on cell type and context.
• In cancer, CCL2 produced by tumor cells or cancer-associated fibroblasts recruits tumor-associated macrophages that promote EMT, stemness, and immunosuppression.
• CCL2 signaling contributes to ischemic stroke, inflammatory pain, and cardiovascular pathology, making it a therapeutic target.
• CRISPR-based knockout, knock-in, and overexpression models are essential to dissect causal roles of CCL2 pathway components in disease.
Description
The chemokine (C-C motif) ligand 2 (CCL2) signaling pathway, annotated as GO:0038148, is a biological process that begins with the binding of CCL2 to its receptor on the surface of a target cell and ends with the regulation of downstream cellular processes such as transcription. CCL2, also known as monocyte chemoattractant protein-1 (MCP-1), is a small cytokine that primarily signals through the G protein-coupled receptor CCR2 to orchestrate monocyte and macrophage recruitment during inflammation. This pathway is highly conserved and plays a fundamental role in immune surveillance, tissue repair, and host defense.
chemokine (C-C motif) ligand 2 signaling pathway At A Glance
| GO ID | GO:0038148 |
|---|---|
| GO term | chemokine (C-C motif) ligand 2 signaling pathway |
| Ontology | biological_process |
| Synonym | CCL2 signaling pathway |
| Major function | Mediates monocyte/macrophage chemotaxis and activation, and regulates downstream transcription via PI3K-AKT, ERK, and STAT3 pathways. |
| Key ligand | CCL2 (MCP-1) |
| Primary receptor | CCR2 |
| Downstream effectors | PI3K, AKT, ERK, STAT3, β-catenin |
| Associated diseases | COPD, cardiovascular disease, ischemic stroke, cancer, inflammatory pain |
What Is GO:0038148?
GO:0038148 is defined as the series of molecular signals initiated by the binding of the C-C chemokine CCL2 to its receptor on the surface of a target cell, and ending with the regulation of a downstream cellular process, e.g. transcription. In simpler terms, it is the entire communication cascade triggered when CCL2 docks onto its receptor, leading to changes in gene expression and cell behavior.
Why Is chemokine (C-C motif) ligand 2 signaling pathway Important in Cell Biology?
The CCL2 signaling pathway is critically important because it serves as a master regulator of inflammatory cell recruitment and is dysregulated in a wide range of human diseases, including chronic obstructive pulmonary disease (COPD), atherosclerosis, ischemic stroke, and multiple cancers. Understanding this pathway at the molecular level provides opportunities for therapeutic intervention and biomarker development.
• Drives monocyte and macrophage infiltration into inflamed tissues, a hallmark of chronic inflammatory diseases.
• Promotes cancer progression by recruiting tumor-associated macrophages that enhance epithelial-mesenchymal transition and cancer stem cell properties.
• Contributes to cardiovascular pathology, including atherosclerosis and myocardial infarction.
• Mediates neuroinflammation and ischemic brain injury after stroke.
• Amplifies inflammatory pain through TRPV1 and TRPM8 activation.
• Regulates immunosuppressive tumor microenvironment via STAT3-CCL2 signaling in cancer-associated fibroblasts.
• Serves as a therapeutic target in COPD, where CCL2-CCR2 blockade alleviates macrophage dysfunction.
• Involved in Crohn's disease complicated by atherosclerosis.
• Modulates hepatocellular carcinoma progression through CCR2-ERK signaling.
• Provides a model system for studying chemokine-receptor signaling and G protein-coupled receptor biology.
What Happens During chemokine (C-C motif) ligand 2 signaling pathway?
CCL2 Binding to CCR2
In simple terms: CCL2 acts like a key that fits into the CCR2 lock on the cell surface.
The pathway is initiated when CCL2 binds to its primary receptor CCR2, a seven-transmembrane G protein-coupled receptor expressed on monocytes, macrophages, and other cell types. This binding triggers conformational changes in CCR2 that activate associated heterotrimeric G proteins, leading to downstream signaling.
Activation of PI3K-AKT Signaling
In simple terms: The signal turns on a survival and growth switch inside the cell.
CCL2-CCR2 engagement activates phosphoinositide 3-kinase (PI3K), which generates PIP3 and recruits AKT to the membrane. AKT phosphorylation then regulates multiple downstream targets involved in cell survival, proliferation, and macrophage function. In COPD, targeting this axis alleviates macrophage dysfunction via the PI3K-AKT pathway.
ERK-Mediated Transcriptional Regulation
In simple terms: The signal travels to the nucleus to change which genes are turned on.
CCL2 signaling activates the extracellular signal-regulated kinase (ERK) cascade, which translocates to the nucleus and regulates transcription factors that control cell proliferation, differentiation, and inflammatory gene expression. In hepatocellular carcinoma, CCL2/CCR2/ERK signaling induced through cancer cell-macrophage interaction contributes to tumor progression.
STAT3 and β-Catenin Pathways
In simple terms: Other internal switches are flipped, promoting immunosuppression and stem-like properties.
CCL2 can activate STAT3 in cancer-associated fibroblasts, promoting an immunosuppressive tumor microenvironment. In triple-negative breast cancer, CCL2/AKT/β-catenin signaling in tumor-associated macrophages promotes epithelial-mesenchymal transition and cancer stem cell properties.
Integration with Pain and Neuronal Signaling
In simple terms: CCL2 can also directly sensitize pain-sensing neurons.
IL-33/ST2 signaling drives inflammatory pain via CCL2, which activates TRPV1 and TRPM8 ion channels on sensory neurons. This demonstrates that CCL2 signaling extends beyond immune cells to directly modulate neuronal excitability.
Key Genes Involved in GO:0038148 chemokine (C-C motif) ligand 2 signaling pathway
The following genes and proteins are central components of the CCL2 signaling pathway and are frequently studied in disease models.
| Gene | Major Role | Research Relevance |
|---|---|---|
| CCL2 | Ligand that initiates signaling by binding CCR2 | Knockout reduces monocyte recruitment in inflammation models |
| CCR2 | Primary receptor for CCL2; mediates chemotaxis and activation | Knockout or antagonist studies block CCL2 signaling in vivo |
| PIK3CA | Catalytic subunit of PI3K; activates AKT | Mutated in cancers; target for pathway inhibition |
| AKT1 | Serine/threonine kinase; promotes survival and proliferation | Phosphorylation readout for CCL2 pathway activation |
| MAPK1 (ERK2) | Kinase in MAPK cascade; regulates transcription | Phospho-ERK used as marker of CCL2-CCR2 activation |
| STAT3 | Transcription factor; drives immunosuppressive gene expression | Activated by CCL2 in cancer-associated fibroblasts |
| CTNNB1 (β-catenin) | Transcriptional co-activator; promotes EMT and stemness | Downstream of CCL2/AKT in breast cancer |
| IL33 | Alarmin that induces CCL2 production | Links inflammation to pain via CCL2 |
| ST2 (IL1RL1) | Receptor for IL-33 | Mediates IL-33-driven CCL2 release |
| TRPV1 | Ion channel; mediates pain sensation | Activated downstream of CCL2 in sensory neurons |
| TRPM8 | Cold-sensing ion channel; contributes to pain | Activated by CCL2 signaling |
| FAP | Fibroblast activation protein; induces STAT3-CCL2 | Target in tumor microenvironment |
| CD68 | Macrophage marker | Used to assess macrophage infiltration in CCL2 studies |
| EMR1 (F4/80) | Mouse macrophage marker | Used in preclinical CCL2 models |
| TGFB1 | Profibrotic cytokine; induced by CCL2 | Contributes to tissue remodeling |
| TNF | Pro-inflammatory cytokine; upregulates CCL2 | Amplifies inflammatory loops |
| IL6 | Cytokine induced by CCL2-STAT3 | Promotes tumor progression |
| VEGFA | Angiogenic factor; modulated by CCL2 | Links inflammation to angiogenesis |
How Is chemokine (C-C motif) ligand 2 signaling pathway Regulated?
CCL2 signaling is regulated at multiple levels. Transcriptional regulation of CCL2 is controlled by NF-κB and STAT3 in response to inflammatory stimuli. Post-translational modifications of CCR2, including phosphorylation and ubiquitination, modulate receptor desensitization and internalization. Negative feedback loops involving regulators of G protein signaling (RGS) proteins attenuate CCL2-CCR2 signaling. In cancer, FAP-positive cancer-associated fibroblasts promote STAT3-dependent CCL2 secretion, creating a feed-forward loop that sustains immunosuppression. Additionally, IL-33/ST2 signaling induces CCL2 production in inflammatory pain.
chemokine (C-C motif) ligand 2 signaling pathway and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| CCL2 | COPD, atherosclerosis, ischemic stroke | CCL2 knockout mice; macrophage-specific overexpression |
| CCR2 | Cardiovascular disease, cancer | CCR2 knockout mice; CCR2 antagonist treatment |
| STAT3 | Cancer immunosuppression | STAT3 knockout cancer-associated fibroblasts |
| AKT1 | Breast cancer EMT and stemness | AKT1 knockout or knockdown in macrophages |
| IL33 | Inflammatory pain | IL33 knockout mice; ST2 blockade |
CCL2 Signaling in Chronic Inflammatory Diseases
In chronic obstructive pulmonary disease (COPD), CCL2-CCR2 signaling drives macrophage dysfunction through the PI3K-AKT axis, and targeting this pathway alleviates disease features. In Crohn's disease complicated by atherosclerosis, network pharmacology and experimental validation identified CCL2 signaling as a key mediator. These studies highlight CCL2 as a therapeutic target in chronic inflammatory conditions.
CCL2 Signaling in Cancer
CCL2 promotes tumor progression by recruiting tumor-associated macrophages that enhance epithelial-mesenchymal transition and cancer stem cell properties in triple-negative breast cancer through CCL2/AKT/β-catenin signaling. In hepatocellular carcinoma, CCL2/CCR2/ERK signaling induced by cancer cell-macrophage interaction contributes to progression. Cancer-associated fibroblasts promote immunosuppression via STAT3-CCL2 signaling.
CCL2 Signaling in Cardiovascular and Neurological Disorders
The CCL2-CCR2 axis plays a pathogenic role in cardiovascular disease, including atherosclerosis and myocardial infarction. In ischemic stroke, upregulated CCL2 promotes injury via chemokine signaling pathways. Additionally, IL-33/ST2 drives inflammatory pain via CCL2 signaling and activation of TRPV1 and TRPM8.
From chemokine (C-C motif) ligand 2 signaling pathway-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does CCL2 drive macrophage recruitment in COPD? | CCL2 knockout mouse model of COPD |
| Is CCR2 required for hepatocellular carcinoma progression? | CCR2 knockout mice with orthotopic HCC |
| Does CCL2/AKT/β-catenin signaling promote breast cancer stemness? | Macrophage-specific AKT1 knockout in TNBC model |
| What is the role of STAT3-CCL2 in tumor immunosuppression? | STAT3 conditional knockout in cancer-associated fibroblasts |
| Does CCL2 mediate inflammatory pain via TRPV1? | CCL2 knockout mice with IL-33-induced pain |
| Can CCL2 signaling be targeted in atherosclerosis? | ApoE knockout mice treated with CCR2 antagonist |
How to Study the chemokine (C-C motif) ligand 2 signaling pathway Process
| Method | What It Measures | Typical Application |
|---|---|---|
| RNA-seq | Gene expression changes | Identify CCL2-regulated transcripts |
| Phospho-ERK immunoblot | ERK activation | Confirm CCL2-CCR2 signaling |
| Flow cytometry | Macrophage surface markers | Quantify monocyte recruitment |
| Immunohistochemistry | Tissue localization of CCL2 and macrophages | Assess inflammation in situ |
| CRISPR knockout screen | Gene essentiality for CCL2 signaling | Discover novel pathway regulators |
| ELISA | Secreted CCL2 levels | Measure ligand production |
| Calcium flux assay | GPCR activation | Measure CCR2 signaling |
| Transwell migration | Cell chemotaxis | Assess functional monocyte recruitment |
Transcriptomic Analysis
RNA-seq can quantify CCL2 and CCR2 expression and identify downstream transcriptional changes upon pathway activation or inhibition. This method is useful for discovering novel target genes regulated by CCL2 signaling in disease models.
Phosphoproteomics
Phosphoproteomic profiling can map the activation status of PI3K-AKT, ERK, and STAT3 pathways following CCL2 stimulation, providing a global view of signaling dynamics.
Flow Cytometry and Immunohistochemistry
Flow cytometry can quantify macrophage infiltration and CCR2 surface expression, while immunohistochemistry can localize CCL2 and CD68-positive macrophages in tissues.
CRISPR Screening
Genome-wide CRISPR knockout screens can identify genes that modulate CCL2 signaling or CCL2-induced phenotypes, such as macrophage chemotaxis or cancer cell proliferation.
How CRISPR Can Be Used to Study GO:0038148 chemokine (C-C motif) ligand 2 signaling pathway
Knockout
CRISPR knockout of CCL2 or CCR2 in cell lines or animal models can abolish pathway activation and is used to test causality in disease models such as COPD and cancer. Knockout of downstream effectors like AKT1 or STAT3 can dissect specific branches of the pathway.
Point Mutation
Introducing point mutations in CCR2 (e.g., phosphorylation sites) or CCL2 (e.g., receptor-binding residues) can reveal structure-function relationships and identify critical signaling residues.
Knock-in
Knock-in of tagged CCL2 or CCR2 (e.g., fluorescent or epitope tags) enables real-time tracking of ligand-receptor dynamics and downstream signaling in live cells.
Overexpression
Overexpression of CCL2 or CCR2 in cell lines or transgenic mice can amplify pathway activity and model disease states characterized by elevated CCL2, such as cancer and chronic inflammation.
How EDITGENE Supports chemokine (C-C motif) ligand 2 signaling pathway Research
Researchers studying chemokine (C-C motif) ligand 2 signaling pathway-related genes often need to determine whether a candidate gene is causally involved in pathway activation or disease progression. EDITGENE provides comprehensive CRISPR-based services to generate precisely engineered cell and animal models for such investigations.
Contact EDITGENE today to design your custom CRISPR model for chemokine (C-C motif) ligand 2 signaling pathway research.
Frequently Asked Questions About chemokine (C-C motif) ligand 2 signaling pathway
What is the chemokine (C-C motif) ligand 2 signaling pathway?
It is the molecular cascade triggered when CCL2 binds its receptor CCR2, leading to downstream cellular responses such as transcription.
What genes are involved in CCL2 signaling?
Key genes include CCL2, CCR2, PIK3CA, AKT1, MAPK1, STAT3, and CTNNB1.
What diseases are associated with CCL2 signaling?
COPD, cardiovascular disease, ischemic stroke, cancer, and inflammatory pain.
How does CCL2 signaling promote cancer?
It recruits tumor-associated macrophages that enhance EMT, stemness, and immunosuppression.
What is the role of CCR2 in CCL2 signaling?
CCR2 is the primary receptor that mediates CCL2-induced chemotaxis and activation.
How is CCL2 signaling regulated?
It is regulated by NF-κB and STAT3 transcription, receptor desensitization, and negative feedback loops.
What experimental models are used to study CCL2 signaling?
Knockout mice, CRISPR knockout cell lines, and overexpression models.
Can CCL2 signaling be targeted therapeutically?
Yes, targeting CCL2-CCR2 alleviates macrophage dysfunction in COPD and reduces tumor progression.
What methods measure CCL2 signaling activity?
RNA-seq, phospho-ERK immunoblot, flow cytometry, and ELISA.
What is the GO ID for CCL2 signaling pathway?
GO:0038148.
Conclusion
The chemokine (C-C motif) ligand 2 signaling pathway (GO:0038148) is a central mediator of inflammation and immune cell recruitment with broad implications for human disease. Understanding its molecular mechanisms through CRISPR-based models and advanced omics approaches can accelerate the development of targeted therapies. EDITGENE provides the tools and expertise to dissect this pathway in any experimental context.
References
- 1. Dong Y et al.. 2024. Targeting CCL2-CCR2 signaling pathway alleviates macrophage dysfunction in COPD via PI3K-AKT axis.. Cell Commun Signal 22(1):364 PMID: 39014433
- 2. Zhang H et al.. 2022. Role of the CCL2-CCR2 axis in cardiovascular disease: Pathogenesis and clinical implications.. Front Immunol 13:975367 PMID: 36110847
- 3. Li L et al.. 2020. Upregulated C-C Motif Chemokine Ligand 2 Promotes Ischemic Stroke via Chemokine Signaling Pathway.. Ann Vasc Surg 68:476-486 PMID: 32422289
- 4. Ishihara N et al.. 2025. Chemokine (C-C Motif) Ligand 2/CCR2/Extracellular Signal-Regulated Kinase Signal Induced through Cancer Cell-Macrophage Interaction Contributes to Hepatocellular Carcinoma Progression.. Am J Pathol 195(3):589-608 PMID: 39756577
- 5. Wu D et al.. 2024. Mechanism of Xue-Jie-San treating Crohn's disease complicated by atherosclerosis: Network pharmacology, molecular docking and experimental validation.. Phytomedicine 135:156169 PMID: 39488873
- 6. Wang L et al.. 2025. IL-33/ST2 drives inflammatory pain via CCL2 signaling and activation of TRPV1 and TRPM8.. Commun Biol 8(1):724 PMID: 40348921
- 7. Yang X et al.. 2016. FAP Promotes Immunosuppression by Cancer-Associated Fibroblasts in the Tumor Microenvironment via STAT3-CCL2 Signaling.. Cancer Res 76(14):4124-35 PMID: 27216177
- 8. Chen X et al.. 2022. Tumor-associated macrophages promote epithelial-mesenchymal transition and the cancer stem cell properties in triple-negative breast cancer through CCL2/AKT/β-catenin signaling.. Cell Commun Signal 20(1):92 PMID: 35715860
