Skip to main content

Human ageing

Understanding the DNA Damage Theory of Aging: Implications for Longevity and Health

DNA Damage Theory DNA damage by UV rays Image credit: Wikipedia The DNA Damage Theory helps to understand how long we live and our health. As we age genetically our cells become more and more damaged, this can be called as cellular aging The theory shows that  Our DNA can hurt inany ways, from inside our bodies and from outside. Things like environmental factors and Oxidative stress can harm our DNA .  Key takeaways • DNA can be damage by   environmental      exposures and oxidative  stress.  • The DNA damage theory explain how    accumulated genetic damage contribute to     cellular aging and impact overall health • Understanding the mechanism of DNA damage is necessary for developing intervention to extend lifespan.  • Ongoing researches are focusing on DNA damage, cellular senescence, and age related diseases.  • DNA repair and reduce the effect of DNA damage, may promote healthy aging. Understandin...
Post a Comment

Telomere theory of aging

Telomere theory of aging

Telomere theory of aging was proposed by a Russian scientist A.M.Olovnikov in the year 1971.In the year 1961,an american scientist L.Hayflick  discovered that cultured human cells can only divide up to 50 times.On the basis of this discovery and it's data A.M olovnikov studied more and proposed the telomere theory of aging. According to the theory,when the telomeres (tail end of  chromosome) become too short the cells lose their ability to divide,gradually it lose its efficiency and become aged.After each and every cell division telomeres are unable to be fully copied,therefore they become shorter and shorter.The telomere theory was fully confirmed when an enzyme called telomerase was discovered in 1984,telomerase can maintain the length of telomeres in cancer cells and germ cells,these cells are devoid of aging and they are immortal.The telomere theory of aging got more popularity when three geneticists,Elisabeth Blackburn,Carol Greider and Jack Szostak got Nobel prize in the year 2009 for Physiology or medicine.Their work was based on telomere and telomerase enzyme, Elizabeth Black burn discovered that telomere have a peculiar DNA,she and Jack Szostak proved that the DNA present in telomere prevent chromosome from being brocken drown when cell divides in the year 1982,Elizabeth Black burn and Carol Greider discovered the enzyme telomerase in 1984.

telomere
Location of telomere

TELOMERE

 Telomeres are the tail ends of chromosomes,working as protective cap.They consist of same sequence of bases.Generally there are four bases adinine,guanine,thymine and cytosine in human being the sequence is TTAGGG(thymine-thymine-adinine-guanine-guanine-guanine),this sequence repeated over and over.This sequence is repeated approximately 2500-3000 times and can reach up to 11000-15000 base pairs.Base sequence differs in different animals,for examble In the case of Bombix mori(insect) the base sequence is TTAGG,ascaris(round worm) the sequence is TTAGGC,Plasmodium(Protozoa) the sequence is TTAGGG(T/C), Paramesium(Protozoa)the base sequence is TTGGG(T/G) and so on.In human telomeres are consisted of TTAGGG sequence of bases,here I am talking about one strand only,what about the other strand?,as we know thymine (T) always pairs with adenine(A),and guanine(G) with cytosine (C) so if TTAGGG sequence is on one strand the other strand sequence will be AATCCC,so one section is made up of six base pairs.
It is noted that the length of telomere in WBC (white blood cells) of newborn babies is 8000 base pairs approx ,but in adult the data is 3000 base pairs and in elderly people it will be 1500.Each time cell divide telomere loses 30 to 200 base pairs.Telomere do not shorten in heart muscles cells,because it do not divide continually .

Cell division

All the living organisms that start their life with a single cell.For growth and reproduction, the cell division is necessary,each parent cell is divides in to two and later, these cells will divide again and this process will continue. There are two types of cell divisions occurs in our body, mitosis and meiosis.The mitosis is the common type which is the process of making new cells in our body,the other one meiosis which makes egg cells and sperm cells.The mitosis cell division is a very critical process, during this the parent cell split in to two identical daughter cells and this process is controlled by a number of genes,even though he length of telomeres decreased after each cell division.The other one the meiosis cell division reduces chromosome number by half( 46 to 23),unlike mitosis the end product of meiosis is four daughter cells with 23 chromosomes) these daughter cells should be sperm cells or egg cells.

 Medicine available to increase life span
many medicine are available at online for altering telomere's length. For example, TA65®.  This is a patented natural herbal product.The company   Claims "this compound can help to maintain the length of  telomeres by activating telomerase enzyme.It can  slow down and possibly,reverse aging". Another one human telomerase reverse transcriptase(hTERT) which is used to diminish telomere's length,you may wonder why should one diminishes telomere's length?, well this is an effective medicine fort cancer,especially for tumors,you know cancer cells are able to produce excess telomerase so the length of telomere never reduced,they are immortal.hTERT used to diminish telomere's length, and therefore the cells become inactive. This type of medicines manufactured a number of companies in different names and different forms.
Conclusion
Telomere theory of aging is a most popular theory of aging.It is proved that after each and every cell division the length of telomere decreases,it is also noted that telomere shortening is different for every one,when we try to measure,for some people you can see the difference in 3 years and some others it can notice in 5 years depend on health status,stress reduction and healthy habits can help to slow the telomere shortening. 
Special info
our blog is again selected for top 60 aging blog, by feedspot.com,again my sincere thanks to Mr. Anuj Agarwal and his team.  

                                                    Next>
Labels:
Location: India

Comments

Post a Comment

Popular posts from this blog

Cross-linking theory of aging

Old couples Image credit goes to pixabay.com Cellinsight Everything about human ageing and related diseases Cross-linking theory The cross-linking theory of aging was proposed in 1942 by Johan Bjorksten. According to this theory Collagen and other proteins undergoing structural changes due to molecular cross linkage (collagen is an important body proteins comprising 30℅ of body proteins) . In the presence of oxygen glucose molecules binding to to proteins and this cross-linked proteins causing damage to cells and tissues resulting in aging. This theory is also called as glycosylation theory of aging.  # Wrinkle and skin changes The cross-linked skin protein collagen  is responsible for wrinkles and skin changes during aging # Tendon stiffening An increased cross-linked collagen is the reason behind tendon stiffening, tendons are connective tissues which connect muscles to bones. a stiff tendon can pass more mechanical energy from muscles to bone but it lose it's elastic...
Post a Comment
Read more

Neuro endocrine theory(biological clock) of aging

NEURO ENDOCRINE THEORY OF AGING  According to Neuro endocrine theory the aging process is happening in hypothalamus,pituitary,and thyroid or the in regulatory action of these glands.Vladimer Dilman an internationally renowned endocrinologist put forward this theory in 1968.He found that there is considerable decline in the production of hormones in our body with increasing age,the secretion of thyroid,adrenel cortex,testis (males),ovary (females),pituitary (growth hormone) etc will falls.The production of aminoacids, peptides,monoamines enzymes etc also will decrease.it is also noted that the functional decline in neurons, Human endocrine system What are the functions of endocrine glands? Endocrine system is a group of glands,which produce most of all important hormones for our body.These hormones controls our growth development,moods,metabolism,reproduction etc. The glands includes Hypothalamus,pituitary,pineal(these3glands situated in brain),thyroid(neck)...
Post a Comment
Read more

Animals who defeated ageing.

Cellinsight Everything about human ageing and related diseases Immortal animals Nothing is forever in this world, death is certain, one day it will visit us. But there are some creatures that never die by natural aging process. Human cells are capable of dividing only 50 times, later the cells entered the senescence stage, and this is the exact reason for aging. Any animal which is not experiencing senescence can defeat ageing, today I am going to tell about such types of animals and how they live without the fear of ageing 1. Jelly fish (Turritopsis dohrnii)  Immortal jellyfish (Image credit goes to Wikimedia )  Jelly fishes are sea animals, included in the phylum coelenterata (cnideria). Turritopsis dohrnii is a species of jellyfish which is known as immortal jellyfish. Jellyfish reproduce both sexually and asexually.The life cycle consisted of three main stages, planulae,polyps and medusae. fertilized egg give birth to planula. The  Planula is the larval stage...
Post a Comment
Read more