### CCR2 Gene Overview

**Gene Symbol:** CCR2  
**Chromosomal Location:** Chromosome 3

#### Function
The CCR2 gene encodes the CCR2 protein, a chemokine receptor that plays a critical role in immune response and inflammation. It primarily functions as a receptor for monocyte chemoattractant protein-1 (CCL2), facilitating monocyte chemotaxis, and is implicated in various inflammatory diseases and tumor responses. It can also act as a co-receptor for HIV-1 infection.

### 1. Associated Genes
CCR2 is known to be functionally associated with several other genes beyond those mentioned in the summaries:

- **CCL2 (MCP-1):** The primary ligand for CCR2, involved in monocyte recruitment.
- **CCL7 (MCP-3) and CCL12 (MCP-5):** Other ligands that interact with CCR2, involved in similar immune response mechanisms.
- **CD4:** Acts as a co-receptor in HIV-1 infection, involved with CCR2.
- **S1P1R:** Sphingosine-1-phosphate receptor associated with thymocyte export, where CCR2 may influence its expression.

### 2. Aging and Age-Related Diseases
Research has implicated CCR2 in various aspects of aging and age-related diseases, including:

- **Inflammatory Disorders:** CCR2-mediated monocyte recruitment is involved in chronic inflammatory conditions such as atherosclerosis and rheumatoid arthritis, which can be exacerbated in older populations.
- **Neurodegeneration:** Enhanced CCR2 activity is linked to chronic neuroinflammation observed in age-related neurodegenerative diseases like Alzheimer's, suggesting a role in modulating inflammatory responses in the central nervous system.
- **Aging and Stem Cell Function:** Studies suggest that CCR2 may be involved in the inflammatory milieu influencing stem cell niches and function during aging.

### 3. Drug Interactions
Several drugs or drug classes are known to interact with CCR2 or influence its signaling pathways:

- **CCR2 Antagonists:** These include small molecule antagonists such as ***CCX140-B*** and ***MSC-C1***, which are being investigated for their potential in treating inflammatory conditions and diseases where monocyte infiltration may play a role.
- **Immunomodulatory Drugs:** Certain immunosuppressant and anti-inflammatory medications may indirectly affect CCR2 expression and function in inflammatory pathways.
  
### 4. Pathways and Biological Processes
CCR2 is involved in several signaling pathways and biological processes, including:

- **Chemokine signaling pathway (Reactome R-HSA-6804709):** Essential for leucocyte migration and recruitment during immune responses.
- **Calcium signaling pathway:** Mediates agonist-dependent calcium mobilization.
- **JAK-STAT signaling pathway:** Utilized in various processes including T-cell differentiation and immune response modulation.
- **PI3K-Akt signaling pathway:** Through activation by CCL2, it mediates chemotaxis and cell migration.
- **Neuroinflammatory response:** Role in macrophage and monocyte recruitment after brain injury, influencing recovery processes.

By participating in these pathways and biological processes, CCR2 is critical for regulating immune responses, particularly in the context of inflammation, tissue repair, and pathologies associated with aging.