### S1PR4 Gene Overview

**Gene Symbol**: S1PR4

**Gene Family**: S1PR4 is a member of the endothelial differentiation, G-protein-coupled receptor (EDG) family. These receptors primarily bind lysophospholipids, particularly sphingosine 1-phosphate (S1P), and are involved in various cellular signaling processes.

**Function**: The S1PR4 gene encodes a receptor that plays a significant role in immune responses and lymphocyte migration. It is functionally coupled to several intracellular signaling pathways through G-proteins, influencing cellular processes such as growth, survival, and movement.

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### 1. Associated Genes

While specific gene associations for S1PR4 are not typically detailed in the summaries provided, S1PR4 may interact with or is associated with:

- **S1PR1, S1PR2, S1PR3, and S1PR5**: Other members of the S1P receptor family involved in similar signaling pathways.
- **CD4 and CD8**: Genes that encode for markers on T lymphocytes which may be influenced by S1P signaling.
- **CXCR4**: A receptor that also plays a role in immune cell migration and may have overlapping functions in lymphocyte trafficking.

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### 2. Aging and Age-Related Diseases

- **Aging**: There is some evidence suggesting that lysophospholipid signaling, including S1P, may have roles in age-related processes, such as inflammation and immune senescence. Changes in the expression of S1PR4 might affect lymphocyte trafficking and function in aging organisms.
- **Age-Related Diseases**: S1PR4 may be implicated in diseases like cancer and autoimmune disorders, as pathways involving sphingosine 1-phosphate are critical in regulating immune responses. Research indicates that dysregulated S1P signaling could contribute to age-related decline in immune function, increasing susceptibility to infections and possibly impacting tumor immunology.

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### 3. Drug Interactions

S1PR4 interacts with several drug classes, particularly those that target sphingosine 1-phosphate receptors:

- **Sphingosine 1-phosphate receptor modulators**: Drugs like Fingolimod (Gilenya), which is used for multiple sclerosis, affect S1PRs and modulate immune responses.
- **Antagonists**: There are specific S1P receptor antagonists explored in the context of autoimmune diseases, but specific antagonists or modulators selectively targeting S1PR4 as opposed to other S1PRs may still be under investigation.
- **Potential implications in cancer therapies** due to the role of S1P in tumor microenvironments and metastasis.

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### 4. Pathways and Biological Processes

S1PR4 is involved in several key signaling pathways and biological processes:

- **Immune System Pathways**: Regulation of lymphocyte migration and homing, which is crucial for effective immune responses.
- **G-protein Coupled Receptor Signaling**: Initiates intracellular signaling cascades upon ligand binding, leading to various cellular outcomes.
- **Cell Migration and Adhesion**: Critical for the movement of lymphocytes to sites of inflammation or infection.
- **Apoptosis and Survival Signals**: Influences the balance between cell survival and death, especially in lymphocytes.
- **Inflammatory Response Pathways**: Potentially modulating the inflammatory environment, relevant in autoimmune diseases and chronic inflammation.

S1PR4 thus represents an important target not just for understanding basic lymphocyte biology but also for therapeutic interventions in various diseases linked to immune regulation and inflammation.