Aging Lecture Flashcards

Flashcards about aging lecture

What factors influence the lifespan differences between worker and queen ants?

Differences in lifespan are seen between worker and queen ants due to differences in genome, hormones, stress, nutrition, and environment.

What are the main theories of aging discussed in the lecture?

Hormones, Hayflick limit, Genetic diseases, Oxidative damage, Mitochondria, Toxin Accumulation, Repair systems, and "Tear and Wear".

What are the problems associated with chronically elevated glucocorticoid levels?

Increased hepatic gluconeogenesis, decreased glucose utilization, increased proteolysis and lipolysis, decreased immune defense, muscular degeneration, hypertonia and osteoporosis.

What is the "Hayflick limit"?

Maximal population doublings for a given cell.

What are telomeres?

Functionless DNA at the ends of chromosomes that shorten with each replication cycle.

Who won the 2009 Nobel Prize in Physiology or Medicine for the discovery of how chromosomes are protected by telomeres and telomerase?

Elizabeth H. Blackburn, Carol W. Greider, and Jack W. Szostak

What is Dyskeratosis congenita caused by?

Mutations in the DKC1 gene, affecting the telomerase complex.

What are the symptoms of Dyskeratosis congenita?

Hair loss, skin lesions, nail dystrophy, lung fibrosis, intestinal diseases, thrombocytopenia, anemia.

Name some progeroid syndromes.

Hutchinson-Gilford Syndrome, Werner Syndrome, and Seip-Berardinelli Syndrome.

What causes Werner syndrome?

Mutations in the RECQL3 gene, encoding a human homolog of E.coli RecQ helicase.

What are the characteristics of Seip-Berardinelli Syndrome?

Pronounced loss of adipose tissue, insulin resistance, diabetes, hypertriglyceridemia, liver steatosis, high appetite.

What are the endogenous sources of ROS?

Mitochondria, Peroxisomes, Lipoxygenase, NADPH oxidase, Cytochrome P-450

What are the exogenous sources of ROS?

UV-light, Radiation, Chemotherapy, Toxins

What are the antioxidants that help resolve oxidative damage?

Antioxidants such as SOD (Superoxide Dismutase), catalase, GPx (Glutathione Peroxidase), Glutathione, Vitamin E, and Vitamin C help resolve oxidative damage by neutralizing free radicals and reducing oxidative stress.

What is GPx (Glutathione Peroxidase)?

GPx (Glutathione Peroxidase) is an enzyme that reduces hydrogen peroxide and lipid peroxides, protecting cells from oxidative damage.

What is SOD (Superoxide Dismutase)?

SOD (Superoxide Dismutase) is an enzyme that catalyzes the dismutation of superoxide into oxygen and hydrogen peroxide, helping to reduce oxidative stress.

What is Catalase?

Catalase is an enzyme that catalyzes the decomposition of hydrogen peroxide to water and oxygen, thereby neutralizing its harmful effects in the body.

What is Glutathione?

Glutathione is an antioxidant that acts as a free radical scavenger, helping to neutralize harmful free radicals and protect cells from damage.

What is Vitamin E?

Vitamin E is an antioxidant that acts as a free radical scavenger, protecting cell membranes from oxidative damage.

What is Vitamin C?

Vitamin C is an antioxidant that acts as a free radical scavenger, helping to neutralize free radicals and protect cells from oxidative damage. It also helps regenerate other antioxidants, like Vitamin E.

Why is mitochondrial damage significant in aging?

Mitochondrial DNA mutation rate is 10-fold higher than in nuclear DNA because mtDNA repair is inefficient.

What leads to Advance Glycation Endproducts (AGE) ?

Glycation, Maillard Reaction

What is Lipofuscin, the age pigment, a result of?

Oxidative Degradation of mitochondria and/or lysosomes.

What are 'Scavenger' Receptors?

Scavenger Receptors are proteins found on cell surfaces that identify, bind, and remove unwanted or modified molecules. For example, they remove oxidized Low-Density Lipoprotein (LDL) from the body, which helps in clearing harmful substances. These receptors play a critical role in maintaining cellular health and preventing disease by clearing debris and modified molecules.

Give two examples of 'Scavenger' Receptors

CD36, CD163

According to Stroo E et al's research from 2017, what cellular functions are reduced in aging cells?

Protein Quality Control (Chaperones, Proteosomes, Lysosomes)

What are the characteristics of Seip-Berardinelli Syndrome?

Pronounced loss of adipose tissue, insulin resistance, diabetes, hypertriglyceridemia, liver steatosis, high appetite.

What is Seip-Berardinelli Syndrome Type I?

Linked to AGPAT2 mutations; presents generalized lipodystrophy, affecting both subcutaneous and visceral fat.

What is Seip-Berardinelli Syndrome Type II?

Caused by mutations in the BSCL2 gene; associated with neurological complications in addition to lipodystrophy.

What is Non-enzymatic glycation?

Non-enzymatic glycation is a process where reducing sugars, like glucose, react with proteins, lipids, or DNA without the involvement of enzymes. This process forms advanced glycation end products (AGEs), which can accumulate over time and contribute to aging and various age-related diseases.

What is the medical relevance of glycation?

Glycation plays a role in several diseases:

• Diabetes: AGEs increase insulin resistance and cause diabetic complications.
• Cardiovascular Diseases: AGEs promote atherosclerosis and vascular dysfunction by modifying LDL and other proteins.
• Neurodegenerative Diseases: AGEs contribute to the formation of amyloid plaques in Alzheimer's.
• Aging: AGEs accumulate in tissues like collagen and α-Cristallin, leading to decreased elasticity, cataracts, and cellular dysfunction. Oxidants and carbohydrates like glucose, galactose, fructose, deoxyglucose, ribose, and deoxyribose can accelerate glycation processes.

What are Advanced Glycation End Products (AGEs)?

AGEs are harmful compounds that form when sugars bind to proteins or fats in your body through a process called glycation. This process is sped up by things like high blood sugar and oxidative stress and can contribute to aging and diseases.