Christina Castellani

Introduction by Dr. Hill.
Christina Castellani, a graduate of Western, shares her academic journey:
- Influenced by strong mentors like Dr. Hill.
- Born and raised in London; pursued an undergrad at Western with a specialization in genetics.
- Developed an interest in genetics after taking cell biology and advanced genetics courses.
- Transitioned to research, completing a Master's under Dr. Shiva Singh and focusing on genomics, especially the changes that occur throughout the lifespan, particularly in identical twins.
- Completed a PhD and a postdoctoral fellowship at Johns Hopkins University.
Currently an assistant professor at Western's Schulich School of Medicine, running a lab focusing on medical bioinformatics.
Teaches computational epigenomics to med sci graduates skilled in genomics and programming.

Mitochondria's Role:
- Known as the powerhouse of the cell, crucial for energy metabolism, cell death pathways, and cellular signaling.
- Bidirectional signals between mitochondrial DNA (mtDNA) and nuclear DNA essential for cell function.
Mitochondrial DNA Characteristics:
- Unique structure: mtDNA is circular, approximately 16kB long, with maternal inheritance only.
- Affected by the cell’s metabolic needs, varying significantly by cell type (e.g., heart vs. liver cells).
Key Metrics:
- Mitochondrial DNA Copy Number: Reflects the quantity of mtDNA in a cell, instrumental in understanding diseases.
- Heteroplasmy: Refers to variations in mtDNA sequences measured as a percentage.
- Haplogroups: Ancestral classification of mitochondrial variations linked to health outcomes.

Aging and Heteroplasmy:
- Increase in heteroplasmy due to accumulated mutations over time.
- Lower mtDNA copy numbers correlate with higher all-cause mortality risk.
Mechanism of Disease Risk:
- Mitochondrial DNA metrics linked to various diseases, including cardiovascular health risks, potentially via perturbed mitochondrial function and energy metabolism issues.
Use of Cohorts:
- The UK Biobank's dataset used to analyze relationships between mtDNA variations and health outcomes.

Environmental Impact on mtDNA:
- Influenced by lifestyle factors such as diet and exercise.
- Research focuses on connections between mtDNA modifications and nuclear epigenome alterations.
- Investigating the effects of various drugs, like statins and acetaminophen, on mtDNA and resulting changes in the epigenome.
Research Hypothesis:
- Investigating whether changes in mitochondrial DNA can influence the nuclear epigenome and disease outcomes.
Notable Experiments:
- Nuclear exchange mice studies show a significant relationship between mtDNA and nuclear gene expression.

Large Scale Human Cohorts:
- Utilization of Canadian Longitudinal Study on Aging (CLSA) and various cohorts for research.
Significant Findings:
- Low mtDNA copy number linked to diseases such as asthma and mini-strokes.
- Association between mtDNA copy number and nuclear DNA methylation observed, indicating potential genetic risk factors.
- Research indicates a direct link between certain diseases and changes in mtDNA.

Developing Cellular Models:
- Laboratory models to explore the effects of reduced mtDNA on nuclear gene expression using CRISPR technology.
- Monitoring consequences of manipulating mtDNA copy numbers on overall cell function, particularly relating to disease mechanisms.
Investigating Environmental Influences:
- Examining how external factors interact with mitochondrial dynamics and lead to epigenetic modifications.

Mitochondrial Transplantation:
- Exploring potential therapeutic avenues like healthy mitochondria injection in treating various conditions.
Future Research Directions:
- Clarifying links between mtDNA variations, epigenetics, and diseases across more diverse populations.
Ethical Considerations:
- Discusses concepts like "three-person babies" and the implications of mitochondrial modification for optimizing health outcomes.