### Overview of EDN3 Gene

- **Gene Symbol:** EDN3
- **Location:** Chromosome 20 (20q13.33)
- **Function:** The EDN3 gene encodes a member of the endothelin family of peptides, which are important vasoconstrictors derived from endothelial cells. The active end product is a 21-amino acid peptide that primarily acts as a ligand for the endothelin receptor type B (EDNRB). 

### 1. Associated Genes

Apart from EDNRB, the EDN3 gene is known to be associated with several other genes notable for their roles in developmental processes and diseases:
- **EDN1 and EDN2:** Other members of the endothelin family that may share functional pathways.
- **SOX10:** A transcription factor critical for neural crest development.
- **RET:** Another gene associated with Hirschsprung disease, involved in neural crest-derived cells signaling.
- **GDNF (Glial cell-derived neurotrophic factor):** Related to RET signaling and has implications in neural crest cell survival.
  
### 2. Aging or Age-Related Diseases

While direct associations between EDN3 and aging or specific age-related diseases might not be extensively characterized, the following points are noteworthy:
- **Tumorigenesis:** Altered expression of EDN3 has been implicated in certain tumors. As tumorigenesis is often associated with aging, dysregulation may relate to age-related oncogenic processes.
- **Neurodegenerative Diseases:** Given its role in neural crest-derived cells, abnormalities in EDN3 expression might impact diseases characterized by neural degeneration and could play a role in aging-related cognitive decline.
- **Cardiovascular Aging:** Endothelins, including EDN3, are involved in vascular function and could be involved in age-related cardiovascular issues given their potent vasoconstriction properties.

### 3. Drugs or Drug Classes Interacting with EDN3

Several drugs and therapeutic agents can interact with the pathways involving EDN3, particularly those influencing the endothelin signaling pathway:
- **Endothelin Receptor Antagonists:** 
  - **Bosentan:** A non-selective antagonist of both EDNRB and endothelin receptor type A (EDNRA), used for treating pulmonary arterial hypertension.
  - **Ambrisentan:** A selective antagonist that primarily targets the EDNRB, used in treating conditions like pulmonary arterial hypertension.
  - **Macitentan:** An orally bioavailable dual endothelin receptor antagonist.
  
These drugs may have implications on clinical conditions related to hypertensive disorders and vascular dynamics.

### 4. Pathways and Biological Processes

The EDN3 gene participates in several important biological processes and signaling pathways:
- **Endothelin signaling pathway:** A key pathway involving vasoconstriction and blood pressure regulation.
- **Neural crest cell development:** Essential for the formation and differentiation of neural crest-derived cells, including melanocytes and enteric neurons.
- **Regulation of Blood Pressure:** Since endothelins serve as vasoconstrictor peptides, EDN3 contributes to cardiovascular regulation.
- **Cell Growth and Proliferation:** Endothelins can influence cell proliferation, and EDN3's altered expression could be involved in both normal physiological and oncogenic cell growth.
- **Regulation of Apoptosis:** Endothelins have been implicated in the modulation of apoptotic pathways, which may be crucial in development and disease processes.

Overall, the EDN3 gene is an essential component in various physiological and pathological processes, with effects ranging from cardiovascular responses to developmental roles in neural crest cell lineage. Further research may continue to elucidate its roles in aging and disease.