Contents

• What is ageing?

• Ageing in plants and animals

• Different factors involved in the ageing process

• Enzymes involved in the ageing process of plants

• Enzymes involved in the ageing process of animals

• Concept about anti-ageing

• Conclusion

• References

Aging • “Aging should refer to changes that

occur with time and therefore will embrace the time based processes of growth and differentiation as well as maturity ,senescence and mortality .” Howard Thomas(2012)

• Reactive oxygen-based cell death theories of plant senescence come

into this category. Van Breusegem & Dat,2006; De Pinto et al., (2011).

Plants and animals aging differences

• Particular significance for ageing is the body plan, which in plants, is continuously expanding by the repetitive proliferation of structural units.

• Differ in some fundamentals of organisation and development - for example, there is no differentiation into germline and soma in plants

• Plants clearly have fundamentally different responses to telomere disruption, probably as a consequence of contrasting developmental and genomic architecturesMcKnight & Shippen (2004) pointed out that. plants have ‘an amazing capacity to withstand raging genomic instability

• In animals continuous expanding by proliferation is done only in clonal animals.

• there may or may not be separation between germline and soma .

• Animals respond to dysfunctional telomeres in such a fundamentally different way because they, unlike plants, have recourse to cell elimination via p53-mediated cell death pathways

• Plants may not be ‘social’ in the animal sense, but they may cluster with their kin due to localized seed dispersal and clonal propagation

• Plant growth is limited by cell division, which depends on water turgor and mineral availability

• DISPERSAL PATTERNS AND FACILITATIVE INTERACTIONS EXTEND LIFE SPAN AS SOCIAL ANIMALS

• Dietary restriction, involving decreased nutritional intake, has been reported to improve health and result in longer life span in animals

THEORIES OF AGING1] Stochastic theories:

‘Changes result from damage due to environmental hazards or accumulation of random events.’

Egs.:

• Free radicals theory – free radicals cause cellular damage; the cumulative effects cause cellular dysfunction, and result in aging.

• ‘Wear and tear’ theory – accumulated damage to vital parts of the cell lead to aging and death.

2] Programmed change theories:

‘Changes that occur with aging are genetically programmed.’

Eg.:

• Involution of the thymus gland gradually impairs the immune system.

THEORIES OF AGING

Factors affecting the ageing process

There are different

Factors that affects

Ageing

• Environmental

• Hereditary

• Extrinsic and intrinsic

• stocastic

• Premature ageing and attitude

• Ageing,smoking and drinking

• Age, Sun, Cold, and Moisture

• Aging and Diet• Aging and Weight• Aging and Choices• Aging and Stress

Environmental factors

• Studies shows that Sugary soft drinks may be linked to accelerated DNA ageing .

• Research finds that people who reported drinking 350ml of fizzy drink per day had DNA changes typical of cells 4.6 years older

©Jeff Chiu/AP(2014)

Pu-erh teas of all varieties, shapes, and cultivation can be aged to improve their flavour, but the tea's physical properties will affect the speed of aging as well as its quality.

by Roc, (2011)

Catalase • the importance of catalase in oxidation protection during accelerated

ageing and repair during subsequent priming treatment of sunflower (Helianthus annuus L.) seeds

• catalase plays a key role in protection and repair systems during ageing. Ageing was associated with H2O2 accumulation as showed by biochemical quantification and CeCl3 staining. Catalase was reduced at the level of gene expression, protein content and affinity.ElsevierIreland,(2011)

Chlorophyllase

• Chlorophyll (Chl) is the most abundant plant pigment found on earth imparting a distinct color to the plant.

• Amongst the biological processes,degradation of Chl is very important and highly regulated as it prevents cellular damage by the photodynamic action of free Chl and any of its degradation products formed in the course of breakdown.

GlutathioneS-Transferase/Glutathione Peroxidase

Methionine sulfoxide reductases

• One of the major targets of reactive oxygen species (ROS), where it is oxidized to methionine sulfoxide (MetO).

• Oxidative damage to proteins is considered to be one of the major causes of aging and age-related diseases.

• Other possible targets for methionine oxidation are proteins that are involved in the regulation of various signal transduction pathways.

• For example,IBa-MetO regulates the release of (NF)-jB; but uncontrolled modifications of IjBa (like MetO) may cause a compromised immune system. Such an event may also cause hyper-sensitivity to environmental stresses, including ROS, which may lead to the development of aging associated diseases.

Telomerase • The enzyme telomerase is responsible for maintaining the integrity of

telomeres.

• The length of telomeres faces gradual decline. This shortening of telomeres is seen as cell damage due to the inability of the cell to double the cause.

• A studyof giant redwood (Sequoiadendron giganteum) showed the DNA of juvenile-phase tissues to be 23% methylated, compared with < 14% for clonally identical adult tissues (Monteuuis et al., 2008).

• Li et al. (2010) showed that phase change in maize is associated with heritable silencing of the MuDR transposable element by the naturally occurring derivative of MuDR,Mukiller (Muk)

• Animals with dysfunctional telomeres develop features of premature deteriorative ageing caused by the activation of cell death pathways (Sharpless & DePinho, 2007).

• Chromosomal fusions and rearrangements become so frequent that the cell is diverted from division into the pathway leading to senescence and death (Forsyth et al., 2002).

• Telomerase is a ribonucleoprotein complex that extends the ends of telomeres after replication through the activity of telomerase reverse transcriptase (TERT; Watson & Riha, 2010).

• So, scientists have determined that there is a direct connection between telomere length and aging

• cellular aging can be bypassed or put on hold by the introduction of the catalytic component of telomerase (i.e., the fuel added to the gas tank to keep the car running)!

• It has been referred to as a cellular immortalizing enzyme.

Superoxide dismutase

• Superoxide dismutase (SOD) is an enzyme that alternately catalyzes the dismutation (or partitioning) of the superoxide (O2

−) radical into either ordinary molecular (oxygen O2) or hydrogen peroxide (H2O2). Superoxide is produced as a by-product of oxygen metabolism and, if not regulated, causes many types of cell damage.

Digestive enzymes

• Digestive enzymes aren’t just beneficial, they’re essential

• as we age there’s increasing suspicion that digestive problems may result from either low stomach acid or enzyme insufficiency in the elderly, which could be what causes acid reflux.

Longe, Jacqueline L.(2014)

Anti-ageing

• Some animals and plants that reproduce asexually “can in principle achieve essentially eternal life.

• “Continue to grow and reproduce after reaching maturity but show no evidence of senescence. In fact fecundity often increases with increasing age. John C. Guerin (2011) (Hydra species; Credit: Oinari san)

Telomerase enzyme activity in ageless animals

• This is an enzyme that protects DNA

• research has shown that sea squirts rejuvenate themselves by activating the enzyme telomerase(Sköld , 2011)

• in this way extending their chromosomes and protecting their DNA

• The animals that can possibly achieve immortality under ideal conditions, such as sea squirts, certain corals, Hydra, and Turritopsisnutricula (the immortal jellyfish), often activate telomerase

Aldabra, the giant tortoise

• Aldabra, the giant Tortoise

• Calculated life span of 255 years

• Died early in a zoo in India due to liver failure and infection – NOT AGE.

Aldabra, the giant tortoise

• Hypothesis: Don’t age due to reactive oxygen species/ oocyte regeneration/ high telomerase expression

• ROS: “chemically active free radicals” that are formed by metabolic energy production. Animals with slower metabolism have better control of ROS, thus less likely to have DNA damage.

Aldabra, the giant tortoise

• Hypothesis: Don’t age due to reactive oxygen species/ oocyte regeneration/ high telomerase expression

• ROS: “chemically active free radicals” that are formed by metabolic energy production. Animals with slower metabolism have better control of ROS, thus less likely to have DNA damage.

superoxide dismutase (SOD)

• aging due to uncontrolled generation of free radicals causes.(Wiseman and Halliwell1996).

• The key antioxidant that decrease the impact of ROS by their specific mechanism is an enzyme, such as superoxide dismutase (SOD).Peerzada Yasir Yousuf et al.(2011)

Glutathione reductase (GR) enzyme activity in ageless plants• Oxidative stress is associated

with abiotic stresses.

• Glutathione reductase (GR) is one of the potential enzymes of the enzymatic antioxidant system

• It has been used in the transgenics to provide the plants with tolerance against the oxidative stress.

• A high dose of short term exogenous D-galactose administration in young male rats produces symptoms simulating the natural aging process. Haider s. et al.(2015)

• Recent Updates in the Treatment of Neurodegenerative Disorders Using Natural Compounds. Rasool M. et al. Evidence-Based Complementary and Alternative Medicine,Volume 2014 (2014), UOL

References

• Thomas,H.(2012) “Senescence, ageing and death of the whole plant”New Phytologist (2013) 197: 696–711

• Ge,Y.et al.(2016) “Inhibition of cathepsin B by caspase-3 inhibitors blocks programmed cell death in Arabidopsis” Cell Death and Differentiation (2016), 1–9 2016 Macmillan Publishers Limited

• Cai, F., L.-J. Mei, X.-L. An, S. Gao, L. Tang and F. Chen,(2011) “Lipid peroxidation and antioxidant responses during seed germination of Jatropha curcas” Int. J. Agric. Biol., 13: 25–30

• Yan,L.et al.(2004) “Gender-specific proteomic alterations in glycolytic and mitochondrial pathways in aging monkey hearts” Journal of Molecular and Cellular Cardiology 37 (2004) 921–929

References

• Hai-Chun Jing, Jacques Hille and Paul P. Dijkwel Ageing in plants: conserved strategies and novel pathways, Molecular Biology of Plants, Groningen Biomolecular Sciences and Biotechnology Institute,University of Groningen, Kerklaan 30, 9751 NN, Haren, The Netherlands:10-20

• Sampath Kumar,N.S.et.al.(2012) Purification and identification of antioxidant peptides from the skin protein hydrolysate of two marine fishes,horse mackerel (Magalaspis cordyla) and croaker (Otolithesruber); Amino Acids (2012) 42:1641–1649

• http://global.britannica.com/science/aging-life-process

• Richard,C.et.al. Enzyme Induction in Aging & Protein Synthesis-4th

edition.(1974).MSS Information Corporation,125-133

• Arking,R. Evolutionary and comparative aspects og longevity and senescence,Biology of Aging: Observations and Principles-3rd

edition(2006) Oxford University Press,122-135

• https://www.theguardian.com/science/2010/nov/28/scientists-reverse-ageing-mice-humans

• Melov,S. et.al. Extension of life-span with superoxide dismutase/catalase mimetics.(2000).US National Library of Medicine. 1;289(5484):1567-9.

• Tosato,M. et.al. The aging process and potential interventions to extend life expectancy.(2007).US National Library of Medicine. 2(3): 401–412.