### HMGN3 Gene Overview

**Gene Symbol:** HMGN3  
**Location:** Chromosome 17  
**Protein Family:** High-mobility group nucleosome-binding proteins

#### 1. Associated Genes:
HMGN3 is known to have regulatory roles that can affect various genes, although specifics beyond those mentioned in the summaries can be less well-documented. However, some interactions include:
- **PDX1** (Pancreatic and duodenal homeobox 1): A pancreatic transcription factor involved in insulin gene regulation.
- **SLC2A2** (Solute carrier family 2 member 2): A key glucose transporter for glucose uptake in pancreatic beta cells.
- **SLC6A9** (Solute carrier family 6 member 9): Involved in glycine transport in neurons.
  
Interactions with transcription factors and chromatin structure imply upstream regulatory roles affecting numerous genes involved in metabolism, transcription regulation, and possibly developmental processes.

#### 2. Aging and Age-Related Diseases:
Although specific studies focusing on HMGN3 alone in the context of aging are limited, its role in chromatin remodeling and gene regulation can have implications for regenerative processes, cellular responses to oxidative stress, and overall cellular aging. Alterations in chromatin structure and gene expression have been correlated with age-related diseases, including:
- **Diabetes Mellitus**: Due to its role in insulin and glucose regulation.
- **Neurodegenerative Diseases**: Given involvement in neuronal glycine transport, any dysregulation might affect synaptic function and cellular health in aging brains.

In general, genes involved in chromatin structure, like HMGN3, may play a role in longevity and cellular senescence owing to their extensive influence on gene expression profiles related to metabolism and repair mechanisms.

#### 3. Drug Interactions:
Currently, specific drugs or drug classes directly targeting HMGN3 are not widely documented. However, compounds affecting thyroid hormone activity could indirectly impact pathways involving HMGN3 due to its interaction with the thyroid hormone receptor beta. Additionally, drugs that affect diabetes (e.g., metformin or insulin analogs) could modify pathways wherein HMGN3 is active:

- **Thyroid Hormone Modulators**: Drugs that influence thyroid hormone signaling.
- **Antidiabetic Agents**: Excess signaling through insulin pathways may intersect with HMGN3-regulated expressions.

#### 4. Pathways and Biological Processes:
HMGN3 participates in several significant biological processes, including:
- **Chromatin Remodeling**: It binds to nucleosomes, facilitating structural adjustments that promote transcription, DNA replication, and repair.
- **Regulation of Gene Expression**: By interacting with promoter regions of various target genes (like SLC2A2 and SLC6A9).
- **Insulin Secretion and Glucose Homeostasis**: Direct implications in pancreatic function and glucose regulation.
- **Developmental Processes**: Highlighted by its possible involvement in ocular development and astrocyte function in the CNS.

**Pathways:** It may be implicated in:
- **Nuclear Hormone Receptor Signaling Pathway**: Related to its binding with thyroid hormone receptor.
- **Insulin/Glucose Regulation Pathway**: Through modulation of pancreatic gene expression linked to glucose metabolism.

#### Summary
HMGN3 is a multifunctional protein with implications in chromatin structure modification, transcription regulation, and regulation of insulin and glucose metabolism, which are critical for processes related to aging and metabolism. Further research is essential to elucidate its role in specific age-related diseases and its potential as a therapeutic target.