People have searched for years for a Fountain of Youth. If it were possible to reverse aging, many diseases such as cancer, neurodegenerative disorders and cardiovascular diseases could be avoided, including cancer, neurodegeneration disorders and cardiovascular issues.
Researchers have already made remarkable strides toward slowing and even reversing animal aging processes. One group led by scientist Shinya Yamanaka has even managed to turn back older cells back to their embryonic states.
Biological Mechanisms of Aging
The biological mechanisms of aging describe the physiological changes that take place as we get older, making us increasingly susceptible to disease and an increase in mortality risk with each passing year. For this reason, understanding these processes of aging is imperative for optimal living.
There are various theories regarding the biological mechanisms of aging. While some focus on damage accumulation, others pinpoint natural decline in function with age; still other theories highlight “programmed aging”, where internal processes (such as DNA maintenance) cause gradual aging processes to take effect over time.
Researcher have long explored the biological mechanisms underlying aging, making great strides toward understanding this process and creating effective antiaging therapies.
At first glance, one of the clearest physical indicators of aging is loss of mobility and strength due to deterioration of body’s structural systems such as bones and muscles. Furthermore, as we age our endocrine and cardiovascular systems become less active, resulting in decreased quality of life overall.
Studies have demonstrated the essential role that cellular senescence plays in biological aging processes. Senescence occurs due to the progressive loss of telomeres – repetitive segments of DNA found at the ends of chromosomes. As each time a cell divides, its telomeres become shorter until reaching a critical length that no longer allows its division; then entering a state of senescence before eventually dying off.
Many other cellular processes also play a vital role in biological aging, including DNA damage, mitochondrial dysfunction and impaired autophagy. These pathways may interact in complex ways to produce different results in specific cases – for instance damaged genes can trigger apoptosis or senescence while the mTOR/S6K pathway determines whether to promote growth or autophagy.
Over recent years, scientists have developed methods for measuring biomarkers of aging. These measurements offer useful ways of assessing an individual’s state of health and detecting any potential problems; one such index, called Frailty Index, which measures aggregate deficits across systems to predict mortality accurately correlates with biological aging.
Reversing Aging in Animals
Scientists have spent decades attempting to increase the lifespan of various organisms like worms and fruit flies as well as lab mainstays such as mice. Drugs and diet-restricted diets have shown promise in lengthening life span and even slowing aging processes.
Recently, US scientists conducted an experiment that may slow muscle cell aging by administering a compound that mimics natural proteins found in our bodies and restore their ability to regenerate themselves. While this was only conducted as a laboratory experiment and not a human trial, these results could pave the way for new anti-ageing therapies in humans.
However, the journey towards reversing human aging will be longer and more complex. Scientists will need to learn what causes cellular-level aging processes before devising methods of manipulation that won’t have unintended side effects.
Stem cell research has proven particularly promising. Stem cells serve as precursors for most of our body’s different cell types and scientists have discovered ways to “jump-start” them, leading them to regenerate faster and look younger. Chemical cocktails have even been used as “booster shots”, encouraging these cells to regenerate quicker and look healthier than ever.
One team of researchers is conducting studies to produce HSCs (hematopoietic stem cells), the master cells responsible for making blood and bone marrow, that are younger versions of themselves and can then be transplanted into patients to extend life expectancies while decreasing the risk of leukemia or other diseases that often arise with older HSCs being used.
Recent experiments by the team focus on Yamanaka factors, chemicals which convert adult cells back into stem cells and have shown promise in mice studies; now the team must assess which combinations of chemicals work for human skin cells as well as for how long.
Reversing Aging in Humans
Researchers are exploring methods of delaying human aging through genetic manipulation. By intermittently stimulating genes to turn cells back into young ones, researchers hope to one day use these techniques as targeted therapies against specific age-related diseases.
Scientists had only ever been able to slow the aging process through genetic engineering of mice until recently; this recent breakthrough marks a significant achievement and could eventually lead to drugs that can reverse human aging.
Scientists have developed an innovative method for rejuvenating ageing or damaged cells in human bodies – for the first time ever successfully applied in human cells. Their research may help prevent or even treat many age-related diseases like heart disease, cancer, Alzheimer’s, Parkinson’s and more.
The new technique employs a cocktail of chemicals to revive muscle and tissue cells while not completely altering their identity, providing added protection from becoming cancerous cells. Furthermore, these cocktails do not damage DNA or reduce cell function significantly.
Scientists are also exploring other means of rejuvenating older cells into younger ones, including using RNA to increase protein production that supports youth. One study involved injecting RNA directly into young mice’s bloodstreams to increase levels of the protein known as PF4. This led to improved brain function and cognition as a result.
Reprogramming factors may provide another method for combatting aging; these are genes designed to induce an anti-ageing response in cells. Although it has shown promise in mouse studies, its efficacy remains uncertain in humans. Scientists are working towards the creation of targeted therapies using these reprogramming factors that treat specific age-related diseases.
Potocsnak Longevity Institute at Northwestern University Feinberg School of Medicine is currently recruiting volunteers for an 18-month longitudinal study that will analyze the relationship between biological and chronological aging. Participants will undergo extensive assessments of their health and wellness as well as an in-depth molecular profiling analysis on all cells in their bodies.
Conclusions
Over the last 30 years, genetics and molecular biology have shed much light on fundamental cellular mechanisms and processes, including embryonic development and cell growth control. Furthermore, researchers have identified numerous genes supposedly implicated in human aging processes; however, none of these studies have shown they can alter rates or life expectancies significantly in humans – perhaps this is because long-term interventions require stringent experimental designs with duration requirements which make long-term intervention efforts very challenging to execute.
Reversing human aging through the reversal of senescent cells is unlikely, given their accumulation of genetic damage that renders them incapable of division. To overcome this limitation, researchers must devise ways of eliminating their presence without leading to uncontrollable cell growth or tumorigenesis.
One of the most promising approaches involves the use of small molecule compounds to trigger reprogramming, where old fibroblasts are transformed into iPSCs that can then differentiate to restore youthful phenotypes. Unfortunately, however, this approach has yet to be successful at increasing life span in animals.
Gene editing technologies offer another promising approach for reprogramming cells into younger phenotypes, but their use remains highly contentious due to the risk that cancerous cells could result from this process.
Gene editing technology has not been successfully translated to clinical practice among humans for several reasons, the main one being ethical considerations associated with its use on living subjects; these concerns center around who should benefit and their effects on society as a whole.
Scientists remain hopeful of their ability to extend human lifespan in the near future, even with setbacks like these. Recently, for instance, researchers reported being able to rejuvenate monkeys using reprogramming technology that erases their senescent phenotype. Furthermore, one recent study demonstrated how exercise and young blood transfusion can significantly slow down the aging process in mice by years or decades.
