Advances in healthcare has led to an increasing lifespan. Over time, our bodies gradually accumulate damage to the cells and tissues and results in physiological ageing. Physiological aging differs from chronological age because it considers factors such as genetics, lifestyle, nutrition, and diseases.
Recently, the process of physiological ageing has been looked at as a disease, and we are just beginning to target ageing to expand our healthspan.
A recent article written by Peter Diamandis explores how genome sequencing and editing, and new classes of anti-ageing drugs are augmenting human biology to extend our healthy lives, a summary of which can be found below.
Genome sequencing and editing
Recent advances have enabled cheap, cost effective sequencing and the cost continues to fall. Sequencing giant, Illumina, has stated that the process will soon cost around $100 and take an hour to complete.
Many decisions can be made using a person’s genetic information, including choosing the perfect drug when someone is sick, the perfect diet for optimal health, a patient’s optimal gut flora and what diseases a patient is more likely to develop and take precautions to prevent onset.
Likewise, scientists are increasingly able to edit the human genome using CRISPR/Cas9. CRISPR is cheap, quick and easy to use and 2018 was filled with CRISPR breakthroughs.
CRISPR-edited immune cells have shown to successfully kill cancer cells in human patients and researchers have discovered ways to use the gene-editing technology to better understand Alzheimer’s disease progression.
Despite the the scientific advances, this has not come without concerns over data privacy, eugenics and ethical issues over what this information can, and cannot, be used for. In 2015, Chinese scientists came under a global fire of controversy when they edited human embryo cells to modify genes that would make the child resistant to smallpox, HIV and cholera. Three years later, a Chinese researcher called He Jiankui released that the first set of CRISPR-engineered twins were born, who were engineered to resist HIV infections. To do this, Jiankui deleted a region of a receptor on the surface of white blood cells called CCR5, which makes it more difficult for HIV to infect white blood cells. However, Jiankui was found to have forged his ethical review documents and misled doctors, resulting in a three year prison sentence and a $429,000 fine.
Programmed cell death
Cells in the human body divide until they reach the Hayflick limit, the number of times a normal cell population divides before cell divisions stop. For humans, this is typically about 50 divisions, and then the cell either undergoes programmed cell death or is destroyed by the immune system. A very small number of cells can evade this fate, which secrete molecules that triggers chronic inflammation, damages the surrounding tissue and changes the behaviour of nearby cells.
Senescent cells appear to be one of the root causes of ageing. Scientists have begun to work on senolytic therapies to selectively destroy senescent cells.
In recent years, researchers have identified or designed compounds that can curb ageing by regulating senescent cells. Two drugs that have gained interest include:
Rapamycin acts on the m-TOR pathway to selectively block a protein that facilitates cell division. Rapamycin derivatives are used for immunosuppression in organ and bone marrow transplants, but research also suggests that use can result in a prolonged lifespan and enhanced cognitive and immune function.
Metformin is a widely-used generic drug for mitigating liver sugar production in Type 2 Diabetes patients. However, researchers have also found that metformin reduces oxidative stress and inflammation, which increases with ageing. There is strong evidence that metformin can increase cellular regeneration and mitigate cellular senescence by reducing oxidative stress and inflammation.
Overall, as healthcare becomes more personalised and our understanding of ageing factors expands, we are likely to see an increase in not only how long humans live, but how long they stay well.
Age 100 could become the new 60, thanks to advances in genetics, genomics, and technology!
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