### CDH8 Gene Summary

**Gene Symbol**: CDH8  
**Gene Description**: The CDH8 gene encodes a type II classical cadherin belonging to the cadherin superfamily, which are integral membrane proteins crucial for calcium-dependent cell-cell adhesion. The structure of mature CDH8 protein features a large N-terminal extracellular domain, a single transmembrane domain, and a small, conserved C-terminal cytoplasmic domain. Its extracellular domain consists of five subdomains with cadherin motifs, influencing its homophilic adhesion properties. CDH8 is predominantly expressed in the brain and is suggested to play important roles in synaptic adhesion, as well as nerve cell processes like axon outgrowth and guidance.

### 1. Gene Associations

While the summaries provided do not list specific gene interactions, CDH8 is often studied in conjunction with other cadherins and neural adhesion molecules, including:
- **CDH2**: Neuronal cadherin involved in synaptic adhesion.
- **CDH5**: Endothelial cadherin important for vascular development and integrity.
- **CDH11**: A cadherin known for its role in mesenchymal processes and osteoblast differentiation.
- **SHANK proteins**: Interacting protein families involved in synaptic signaling and scaffolding.

### 2. Aging and Age-Related Diseases

Current research linking CDH8 to aging or age-related diseases remains limited. However:
- Alterations in cadherin expression, including type II cadherins like CDH8, have been implicated in neurodegenerative diseases such as Alzheimer's, where impaired cell-cell adhesion can affect synaptic integrity and neuron communication.
- Changes in synaptic adhesion molecules like CDH8 during aging may contribute to cognitive decline and synaptic dysfunction, suggesting a putative role in age-related neurodegeneration.

### 3. Drug Interactions

There are no specific drugs or drug classes directly known to interact with the CDH8 gene itself. However, some drugs that modulate calcium pathways or function as modulators of cellular adhesion (e.g., certain anti-cancer agents targeting cell adhesion and migration) might indirectly influence cadherin function, which includes CDH8.

### 4. Pathways and Biological Processes

CDH8 is involved in several biological processes and pathways, including:
- **Cell Adhesion**: Crucial for maintaining tissue architecture and facilitating communication between cells.
- **Neural Development**: Plays roles in axon guidance and synaptic connections during brain development.
- **Wnt Signaling Pathway**: Cadherins can interact with Wnt signaling, a pathway important for various cellular processes, including cell fate determination and polarity.
- **Neuronal Synapse Formation**: Essential for the formation and maintenance of synapses in the nervous system.

**Conclusion**: The CDH8 gene is integral in neuronal development and function, impacting cell adhesion in the brain. Its association with aging and neurodegeneration, although not extensively characterized, indicates its potential significance in research on age-related conditions. Further studies may reveal therapeutic targets linked to CDH8 in neurological diseases.