### FABP5 Gene Overview

**Gene Symbol**: FABP5  
**Location**: Chromosome 4q28.2  
**Gene Type**: Protein-coding gene

**Description**:  
FABP5 (Fatty Acid Binding Protein 5) encodes a protein that plays a significant role in the intracellular transport of long-chain fatty acids and other hydrophobic ligands. Initially identified as being upregulated in psoriasis, this gene is part of a broader family of fatty acid-binding proteins involved in various metabolic processes.

### Additional Gene Associations
1. **FABP4** (Fatty Acid Binding Protein 4): Shares structural similarities and is also involved in lipid metabolism. Notably plays a role in adipocyte metabolism and inflammation.
2. **PPARs** (Peroxisome Proliferator-Activated Receptors): These nuclear receptors are regulated by FABP5 by binding to fatty acids which modulate their activity.
3. **NF-kappa-B**: Involved in the inflammatory response that FABP5 regulates.

### Aging and Age-Related Diseases
- **Metabolic Disorders**: Polymorphisms in FABP5 have been associated with the risk of developing type 2 diabetes, a condition that is more prevalent in aging populations.
- **Inflammation**: As aging is associated with chronic inflammation (inflammaging), FABP5's role in modulating inflammation via prostaglandin synthesis may indicate its involvement in age-related inflammatory diseases and conditions.
- **Skin Aging**: Given the gene's involvement in keratinocyte differentiation, it may also play a role in skin aging processes, especially considering its association with psoriasis.

### Drugs and Drug Classes
While there are not many specific drugs directly targeting FABP5, it is important to note:
- **Thiazolidinediones**: These diabetes medications act on PPAR receptors, which are influenced by FABP5 activity. 
- **CB1 antagonists**: Since FABP5 is implicated in endocannabinoid transport and signaling, drugs that modulate cannabinoid pathways may indirectly affect FABP5 functions.

### Pathways and Biological Processes
1. **Fatty Acid Metabolism**: Involved in the uptake, transport, and metabolism of fatty acids and related lipids.
2. **PPAR Signaling Pathway**: FABP5 plays a crucial role in this pathway by delivering fatty acids that activate PPARs, which are involved in lipid metabolism, glucose homeostasis, and inflammation.
3. **Cytokine Production**: Regulates NF-kappa-B signaling, which is a key pathway in immune response and inflammation.
4. **Endocannabinoid Signaling**: Participates in retrograde signaling affecting synaptic activity in the central nervous system.
5. **Keratinocyte Differentiation**: Contributes to epidermal homeostasis and may influence processes related to wound healing and skin integrity.

### Summary
FABP5 is a critical player in lipid metabolism, inflammation, and keratinocyte function. Its interactions with numerous pathways underscore its importance in both metabolic disorders and skin-related conditions, especially those that manifest in aging populations. Continued research may further elucidate its roles and potential therapeutic targets related to metabolic syndrome and inflammatory diseases.