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...
Cellinsight Everything about human ageing and related diseases
Lipids
Lipids are organic compounds, basically hydro carbons. They are non-polar ( means they don't have negatively or positively charged ends) so they are not soluble in Water, but easily soluble in organic solvents such as chloroform, acetone, benzene,alcohol etc. Fats, oil, wax etc, are the examples of lipids. Lipids are necessary to make cell membranes, the outer most two layers of cell membrane is made up of phospholipids, which protect cell from surroundings and also helps cell more strong and flexible. Energy storage ( excess energy stored in adipose tissue in our body and used when ever needed), they used to transmit nerve impulses, and many more..
Lipid metabolism
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Endocrine system in our body, releasing hormones which control growth and metabolism. According to their chemical structure hormones are classified into Lipids derived hormones, Amino-acids derived hormones, and peptides derived hormones. When we examine the Lipids-hormones in our body, most of them are steroid based ending in '-ol' or '-one'. The '-ol' group stands for alcohol and '-one' group for the representation of ketone.
Examples:
Testrone - male sex hormone
Estardiol - female sex hormone
Aldosterone - produced by adrenal gland, used to regulate salt and water in our body.
Cortisol - stress hormone, produced by the adrenal gland
How Lipids related to ageing?
Body fat increases with aging, because of decreased lipid metabolism.Lipid metabolism means the production or degradation of lipids. Lipid metabolism play a major role in ageing process. Lipids are the immediate sources of energy, lipids metabolism can release more energy than carbohydrates or proteins metabolism (lipids_9kcl/g, proteins_4kcl/g, carbohydrates_4kcl/g). Our body obtained the lipids from diet and also in our body the liver produced Cholesterol and Phospholipids in large quantities.
The fat oxidation process consisted of two stages, the release of fatty acids from adipose tissue and it's oxidation process in the respiring tissues. The fatty acids released from adipose tissue in older people are comparatively larger than younger people, still the oxidation rate is low! Why this happened? Fat free mass is more metabolically active than fatty tissues, in the case of older people most of their tissues and organs filled with fats. Another reason may be the reduced quantities of enzymes needed for lipids oxidation. The enzymes involved in lipids catabolism are Canitine, Palmitoy transferase1, Acetyl-coA Carboxylase, Fatty acid synthase and 3-hydroxy-3-methyl glutaryl co enzyme.
Elovl2 (elongation of very long chain fatty acids-like 2) is a gene which regulates the lipid metabolism in the body. Elovl2 Catalyzed the production of very long chain of polyunsaturated fatty acids like omega-3 and omega-6 which are very important for many vital biological activities in the body. Experiments on mouse shows that aging of retina and the resultant visual deficiency is linked with the expression of
Elovl2 gene. Methylation of Elovl2 gene altered it's expression, after testing the percent of methylation on Elov2 one can predict the chronological age of a particular organism.
Human blood contain lipids in the form of triglycerides (fatty acids) and cholesterol (sterols) , both are lipids but they are different in their structure and function. Cholesterol is used to make some hormones and building cells, while triglycerides are reserved energy molecules which provides imminent energy to the needed tissues and cells. Lipids are hydrophobic ( not soluble in In water) in nature, then how it circulated in our blood?. Proteins and lipids combined to form a special substance, it is actually a biological assembly, the product is Spherical in shape and is known as Lipoprotein, so it can circulate through blood stream. There are four type of lipoproteins, VLDL (Very low density lipoprotein), LDL(low density lipoprotein), HDL(high density lipoprotein) and Chylomicron( used to transport very long chain of triglycerides).
Triglycerides are very important and necessary, but it is harmful if it's level increased in the blood, it cause obesity and heart diseases. It's level should be below 150 , in your lipid profile test. When we talk about cholesterol LDL that is bad cholesterol it sometimes block the arteries, and it Should not be above 100 level. HDL is the good cholesterol it can be 40 or heigher. Many scientific experiments proved that a perticular lipid profile can increase your lifespan considerably.
Old age diseases linked with lipid
An impaired lipid metabolism can donate us many diseases such as Gaucher disease, Tay_ sachs disease, Niemen-pick disease.Liver diseases, kidney disease, Acid lipase disease, high cholesterol, neural lipid storage disease and many more. Most of the above mentioned diseases are hereditary, but we are discussing lipids and old age diseases, ok let us check what are those diseases?
# cardio vascular diseases
Because of decreased lipid degradation, during ageing triglycerides and cholesterol sharply increased in blood, by the age of 40 we have cholesterol deposit in our arteries and in the case of women it will be 55 and above. This condition is called asthero Sclerosis, it affect the stiffness of arteries and overall performance of the blood pumping system.
#type_2 diabetes
Type 2 diabetes is generally seen in adult, but it can be in childhood if there is insulin deficiency in their body. High blood sugar, high triglyceride level and low high density cholesterol (HDL) are the symptoms of diabetes. This may happened because of two reasons,the body is resisting the insulin or the pancreas is not producing sufficient insulin.
#Alsheimer's disease
Alsheimer's disease caused by the deposit of Amylase protein and mis folded Tau proteins. Amylase proteins are mis folded proteins or damaged proteins and are not active in biological activities actually they are wastes. Where as Tau protein mostly present in Central nervous system which give stability to micro tubules in axon. Damaged tau protein also deposit on neuron and obstructing the neural functions.
But several new studies suggest that a defective lipid metabolism in brain is an important reason for Alsheimer's disease and other neurodegenerative diseases. As we know that the rate of lipid metabolism decreased, and making many errors in the metabolic process in older people
#arthritis
Elderly people who suffering from rheumatoid arthritis have lower high density lipoprotein cholesterol (HDL_C) in their lipid profile test, and apolipoprotein A-1( the primery protein component of HDL) also found low.
#cancer
Defective cellular and intercellular membranes are considered as one of the characteristics in the case of canser as well as aging. Now a days replacement of lipid membranes can be possible. The medicine used for this purpose is an oral supplement containing a mixture of membrane glycerol phospholipids, fructo oligosaccharides and antioxidants. It is saying that this therapy can restore cell membranes and mitochondrial functions. That means your are getting some sort of relief from both cancer and aging.
Conclusion
# Lipids are very important organic compounds necessary for our body
# Lipids are as important as proteins
# Lipids are immediate source of energy in our body.
# Lipids metabolism ( catabolism) can yield more energy than carbohydrates Or proteins
# Lipid metabolism rate falling as we get old
# Lipid metabolism play a vital role in aging.
# Impaired Lipid metabolism is causing many diseases
# It is scientifically proved that a specific lipid profile can increase a person's life span considerably.
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