Telomeres, Aging, and Cancer: Molecular Insights

Replicative Cell Senescence

Limited cell divisions due to telomere shortening.

Telomeres

Repetitive DNA sequences at chromosome ends.

Telomerase

Enzyme that synthesizes telomeric sequences.

p53 Activation

Triggers cell cycle arrest due to DNA damage.

Somatic Cells

Non-reproductive cells lacking telomerase expression.

Cancer Cells

Regain telomerase production, enabling proliferation.

Species-Specific Longevity Genes

Genes influencing lifespan across different species.

Oxidative Metabolism

Metabolic process linked to aging damage.

Nuclear DNA Damage

Accumulation of mutations leading to aging.

MMR Enzymes

Repair mechanisms for DNA replication errors.

Reactive Oxygen Species (ROS)

Byproducts of respiration causing cellular damage.

Ataxia-telangiectasia

Neurodegenerative disease from ATM gene mutations.

Double-Stranded Breaks

Severe DNA damage requiring repair mechanisms.

Nucleotide Excision Repair (NER)

Pathway repairing bulky DNA lesions.

Transcription-Coupled Repair

NER subpathway for active gene damage repair.

Global Genome Repair

NER subpathway repairing damage throughout genome.

Telomere Shortening

Progressive loss of TTAGGG repeats with division.

Molecular Clock

Telomere shortening indicates biological aging.

T loops

Telomeric loops formed by G strand overhang.

Germ Cells

Reproductive cells expressing high telomerase levels.

Premature Aging Syndromes

Conditions characterized by short telomeres.

Genomic Instability

Increased mutations leading to cell dysfunction.

Telomere Repeat Binding Factors

Proteins binding to telomere repeats for protection.

Intrinsic Sources of Damage

Internal factors causing DNA mutations.

Extrinsic Sources of Damage

External factors like radiation causing DNA damage.

Bloom Syndrome

Genetic disorder causing short telomeres and cancer.

BLM Gene

Helicase gene associated with Bloom syndrome.

Werner's Syndrome

Premature aging disorder with multiple symptoms.

WRN Gene

Helicase gene linked to Werner's syndrome.

Telomeric Instability

Unstable telomeres leading to premature cell aging.

Dyskeratosis Congenita

Genetic disorder causing decreased telomerase activity.

Terc

Gene encoding RNA component of telomerase.

Dyskerin (DKC1)

Protein that stabilizes Terc in telomerase.

Mitochondrial Theory of Aging

Aging linked to mitochondrial DNA mutations.

mtDNA

Mitochondrial DNA, crucial for cell energy.

Apoptosis

Programmed cell death mechanism.

mtPTP

Mitochondrial permeability transition pore.

Oxidative Damage

Cellular damage from reactive oxygen species.

Haplotype J

mtDNA lineage associated with longevity.

Insulin/IGF-1 Pathway

Hormonal pathway affecting lifespan in organisms.

Indy Gene

Gene linked to extended lifespan in flies.

Sirtuins

Protein family regulating lifespan through deacetylation.

Caloric Restriction

Dietary reduction that may extend lifespan.

ROS Detoxifying Enzymes

Enzymes that neutralize reactive oxygen species.

Mismatch Repair Enzymes

Enzymes correcting DNA replication errors.

RNAi

Gene silencing technique to extend lifespan.

Epigenetic Dysregulation

Altered gene expression patterns during aging.

Oct4, Sox2, Klf4, c-Myc

Factors used for cellular reprogramming to pluripotency.

Cellular Senescence

State where cells stop dividing and function.

Chromatin Regulators

Proteins that maintain chromatin structure and function.

Genome Stability

Integrity of genetic material over time.