What are Sirtuins? – Overview
Sirtuins are a family of NAD-dependent proteins with deacetylase or ADP-ribosyltransferase activity.
They are found in many living organisms, from bacteria to mammals, and regulate essential cellular processes and metabolic pathways.
“Sirtuin” stands for “Silent information regulator proteins”. The name already partly tells us their function; they regulate, hence, turn on and off genes responsible for various processes maintaining homeostasis.
There are 7 sirtuin proteins in the family, named and coded by genes SIRT1 to SIRT7 accordingly.
Proteins SIRT 1,6,7 are found in the cell’s nucleus, 3,4,5 in mitochondria, and only SIRT2 is in the cytoplasm.
Most attention comes to SIRT1 and SIRT6 proteins and their effects on metabolism.
Sirtuins and metabolism
The SIRT1 protein, the first member of the sirtuin family, is involved in various intracellular processes, including those responsible for aging. SIRT1 also deacetylates specific transcription factors and enzymes to influence their activities
It is expressed in most organs, including the brain, liver, heart, skeletal muscle, spleen, kidney, etc. It is responsible for boosting metabolism and is sometimes called the “skinny gene”.
Reductions in SIRT1 levels were observed in different disorders, including obesity. Furthermore, an increase in SIRT1 expression also increases insulin sensitivity in pancreatic beta cells.
SIRT1 activity is responsible for enhanced mitochondrial function, which itself means increased exercise tolerance and thermogenesis, leading to protection against the onset of obesity and associated metabolic dysfunction.
This protein is known to repress glucose and fatty acids storage in adipose tissue.
Another interesting observation is that period of temporary fasting raises the expression and activity of SIRT1.
The body produces a maximum amount of sirtuin during times of stress – for example when you limit the calorie intake of your daily diet.
But, the fewer calories we consume, the higher the expression level of the “skinny gene.”
It is also known that fasting starts cell repair processes, increasing their lifespan.
Intermittent fasting has many beneficial effects on our bodies, but that is a subject for another article.
Sirtuins and Anti-aging
These proteins are also “restorers”, meaning they restore damaged cell DNA (from UV rays, oxidative stress, etc.), increase the rate of regeneration, and improve the healing of injuries and wounds – in other words, they eliminate cell damage and prolong its life.
Sirtuin promotes cell survival by preventing cell apoptosis – so-called programmed cell death.
DNA “breakdowns” are rare in a young organism, and sirtuins actively manage to “repair” them in time.
With age, the damage becomes more, and the family of sirtuins becomes less active.
As a result, they do not have time to repair all the damage, and problems accumulate.
According to the theory of accumulation of damage – one of the generally accepted theories of aging – deficiency and insufficient activity of sirtuins are among the factors in the development of aging processes in the body, including in the skin.
From the Sirtuin family, SIRT6 activity is associated with extending the healthy human lifespan of a cell by maintaining genome integrity.
This activity relates to the SIRT6 function in base excision repair (BER) of single-stranded DNA breaks.
That’s what leads to the development of various SIRT6 activators, the consumption of which has the potential to increase the lifespan.
According to a 2017 PubMed study: “Results from animal models, observations at the cellular level and data obtained from human studies suggest that sirtuins could be considered a key regulator of aging.
The level of these enzymes decreases with age while their up-regulation alleviates the symptoms of aging/cellular senescence”
These “skinny genes” are known to be activated by polyphenols; hence consuming foods that can trigger these genes, such as red wine, chocolate, strawberry, and kale, can potentially boost your metabolism and even have an anti-aging effect.
Those also are the cornerstone products of the sirtfood diet. You probably have heard about the diet since the shocking transformation photos of British singer – Adele resurfaced.
The Sirtfood diet offers foods that stimulate the production of sirtuins; this nutritional strategy is becoming trendy nowadays since it not only actively burns fats but also ensures the correct functioning of all organs and systems of the body.
Although its efficiency in weight loss has not been scientifically proven, Sirtfood Diet Plan is meant to focus on foods that are sirtuin activators.
Sirtuins are a family of proteins that have several beneficial functions for the human body, including:
- Protects the cells of our body from inflammation and destruction
- Promotes DNA stability
- Regulates metabolism
- Increases muscle mass
- Burn fat
- Increase in insulin sensitivity
- Increased exercise tolerance
- Prevents the development of certain chronic disorders like obesity, metabolic syndrome, cardiovascular diseases, and neurodegenerative diseases.
Gvantsa Qvariani is a medical doctor, DTMU graduate, an American MD program based in Georgia. Gvantsa has spent the last 6 years studying and practicing medicine in Georgia and other parts of Europe. She is active in medical researches, scientific conferences, various medical projects and so on. She is specialized in writing medical content based on newest studies from most reliable sources.