Path 2: Genomic Instability

Rationale: DNA damage as the root of aging. This path focuses on the accumulation of DNA mutations, strand breaks, and other genomic lesions over time. As repair systems falter, cells suffer loss of genetic information integrity, leading to malfunction or cell death. Many progeroid syndromes are caused by mutations in DNA repair genes and resemble accelerated aging. Mice with deficient DNA repair age rapidly, whereas enhanced repair might extend lifespan.

Prerequisites: Molecular genetics, DNA repair pathways (NER, BER, NHEJ, etc.), genomics.

Dependencies: Connects with Path 1 (evolutionary: why perfect repair didn’t evolve) and with other damage-centric paths (ROS, telomeres cause DNA damage).

Signs of Progress: Creating organisms with enhanced DNA repair fidelity that demonstrably age slower. Developing accurate measurements of DNA damage as biomarkers of aging and seeing them reduced by interventions. Mapping the “mutation burden” with age and linking it causally to functional decline.

BC2.1: DNA Damage & Repair 101

Scope: Master basics of DNA damage types and main repair pathways. Understand how repair efficiency changes with age.

• Lindahl, T. “Instability and decay of the primary structure of DNA.” Nature, 1993. – A classic paper by a Nobel laureate, highlighting how DNA is inherently damage-prone.
• Alberts, B. et al. Molecular Biology of the Cell, 6th ed., Garland Science, 2015 – Chapter on DNA Repair. – Clear diagrams and explanations of each repair mechanism.
• Vijg, Jan & Suh, Y. “Genome instability and aging.” Annu. Rev. Physiol., 2013. – A focused review connecting repair mechanisms to aging phenotypes.

BC2.2: Evidence Linking DNA Damage to Aging

Scope: Study progeroid syndromes and model organisms (Werner syndrome, Cockayne syndrome, HGPS, Ercc1 knockout mouse).

• Hoeijmakers, Jan H. “DNA damage, aging, and cancer.” N Engl J Med, 2009. – Highly cited review by a leader in DNA repair and aging.
• de Magalhães, João Pedro. “Accelerated aging in mice.” Mech. Ageing Dev., 2005. – Summarizes various progeroid mouse models.
• Martin, George M. “Genetic syndromes in man with potential relevance to the pathobiology of aging.” Science, 1978. – Old but gold: first connected human progeroid syndromes to aging research.

BC2.3: Somatic Mutation Accumulation

Scope: Investigate how much mutation actually accumulates in normal aging. Discuss the “error catastrophe” concept.

• Vijg, Jan. Aging of the Genome: The Dual Role of DNA in Life and Death. Oxford Univ. Press, 2007. – Comprehensive book by a leading researcher on genome aging.
• Lu, Ao & Zhang, L. “Single-cell genomic analyses in aging.” Genome Biol., 2019. – Technologies and key discoveries, like increased mosaicism in neurons and stem cells.
• Richter, C. “Oxidative damage to mitochondrial DNA and its relationship to aging.” Int. Rev. Cytol., 1995. – Focus on mitochondrial DNA mutation accumulation.

BC2.4: Therapeutic Targeting of Genomic Instability

Scope: Strategies to enhance DNA repair, selectively remove damaged cells, or prevent damage.

• Schumacher, Björn et al. “Translating DNA damage responses into aging interventions.” Nat. Rev. Mol. Cell Biol., 2021. – State-of-the-art review on using DNA damage knowledge to mitigate aging.
• CERES Workshop Report on DNA Repair and Aging, 2018. – Consensus on promising interventions.
• Gorbunova, Vera et al. “DNA repair in species with extreme lifespan differences.” Nature, 2007. – Compares DNA repair efficiency in short-lived vs long-lived rodents.

Bibliography (Path 2)

• Hoeijmakers, Jan H.J. “DNA Damage, Aging, and Cancer.” N Engl J Med 361(15): 1475–1485, 2009. (Detailed review linking DNA damage accumulation to aging)
• Schumacher, Björn et al. “Translating DNA Repair into an Anti-Aging Therapeutic.” Nat. Rev. Mol. Cell Biol. 22(2): 75–89, 2021. (Strategies to enhance DNA repair as interventions for aging)
• Gorbunova, Vera et al. “Life History Trade-offs Explain the Evolution of Somatic Maintenance and Repair.” Cell 120(4): 466–477, 2005. (Comparative data on DNA repair capacity vs longevity)
• Vijg, Jan & Judith Campisi. “Puzzles, Promises and a Cure for Aging.” Nature 454(7208): 1065–1071, 2008. (Debate on whether genomic instability is a cause of aging or primarily cancer-related)
• Béringue, Vincent et al. “DNA Repair in Aging and Longevity.” J. Intern. Med. 279(5): 523–536, 2016. (How organisms with exceptional longevity often have superior DNA repair)