Reverse Aging in Mice
David Sinclair and his team of molecular biologists are using proteins that can turn cells back into stem cells to transform old mice back into young ones, rejuvenating their eyes, brain tissue, and other organs of these aged creatures.
Scientists bred mice that lacked an enzyme called telomerase, which prevents their chromosomes from shortening and contributing to age. After administering injections to restore its activity, organs in these mice became younger as their organs started working normally again.
Improved Eyesight
Researchers claim they have discovered a way to reverse the aging process in mice, moving closer toward finding a medical fountain of youth. Their breakthrough may provide new treatments for diseases like diabetes and Alzheimer’s as well as extend human lifespan.
Scientists used genetic information introduced into cells to reverse time on genes responsible for cell aging and death, ultimately improving health including improvements to vision.
One of the leading causes of aging is DNA damage to telomeres at chromosome ends, known as telomeres. When too little DNA protection remains at these ends, cells eventually stop working properly and start breaking down. To counteract this situation, our bodies have an enzyme called telomerase which works to repair damaged telomeres; but with age comes decreased levels of this natural defense mechanism and consequently shorter DNA fragments which eventually stop functioning normally and eventually leads to cell death.
The team bred genetically modified mice that are lacking key components of telomerase, making it impossible for them to repair their telomeres. After giving these mice injections that reactivated telomerase, after one month of treatment they found that ageing had been reversed – organs had been rejuvenated, brain size had increased, coat hair returned to its healthy sheen and fertility had returned!
Harvard team’s research is grounded on the premise that many diseases and conditions associated with aging stem from its biological process itself. Sinclair and colleagues have previously shown that injecting young mouse blood through veins of older mice will have rejuvenating effects – these mice lived 9% longer than mice who didn’t receive younger blood.
Increased Brain Size
Researchers have developed an innovative solution to reverse mouse aging and rejuvenate their cells, suggesting that reprogramming epigenetic “software glitches” responsible for many age-related diseases could provide a viable anti-ageing treatment option. Led by molecular biologist David Sinclair of Harvard Medical School, they have identified key switches which turn an adult cell back into stem cell form during telomere regeneration — known as telomere regeneration — as well as methods for changing back their genetic code to an earlier version without losing identity – something they believe essential for reverse aging and lengthening lifespan.
Researchers published in Science Advances published their study where they made cuts in lab mice’s DNA to simulate wear-and-tear damage caused by sunlight and cosmic rays, then treated these mice with Yamanaka factors which are known to reverse cell aging.
The gene therapy worked by clearing away thousands of chemical marks that accumulate on DNA sequence and lead to cell decay over time. Mice that received gene injections experienced restored eyesight, increased brain size, muscle growth and organ regeneration (such as kidneys and intestines regenerating faster), as well as living up to 9 percent longer lives than mice that hadn’t received gene therapy injections.
Results may be promising, but replicating this work on humans will be much harder. Mice produce an enzyme known as telomerase to keep their chromosomes from shortening too rapidly; this feature of humans has been turned off as an evolutionary safeguard against cancer; activating this gene would increase our healthy years but make us more prone to cancerous growths.
Even with these challenges, researchers remain optimistic that the next generation of anti-aging drugs will outshone what exists today. Some companies already offering regenerative medicine to delay diseases associated with age such as heart disease and dementia while others target specific illnesses in elderly such as cancer or diabetes.
Rejuvenated Organs
Researchers at Harvard Stem Cell Institute have made failing hearts of elderly mice more like those found in younger healthy mice and increased brain and skeletal muscle function in these aging mice, raising hope that similar treatments could benefit human health and extend human lives.
Biological aging is caused by DNA damage, with one major contributor being cells’ declining capacity to divide. Every time cells divide, their telomeres shorten until they trigger self-destruction of that particular cell or cause its division to cease altogether. Unfortunately, human bodies don’t produce an enzyme called telomerase that could reverse this process; however, scientists have recently developed ways of making telomerase work again!
Professor Ronald A. DePinho of the Dana-Farber Cancer Institute had anticipated just stabilizing cellular aging; instead, his team saw complete reversal of it in mice! By raising levels of telomerase protein they discovered they could rejuvenate worn-out organs by rejuvenating worn-out tissues with rejuvenation therapy.
DePinho and his colleagues conducted a study published in Aging that involved breeding genetically modified mice that produced high levels of telomerase. After administering an activate telomerase drug to these mice, their organs continued to function normally and they lived longer – evidence that DePinho and co. had found a magic formula to delay and reverse aging.
To test their discovery, scientists administered an injection of molecules into the eye of a mouse that had experienced retinal ganglion cell damage. The chemicals converted the damaged cells back into stem cells and reversed cellular aging within its retina – new axons sprouted between retina and brain as well. They have since found that using similar cocktails they can also turn senescent cells back into stem cells in muscles and brain tissue.
But this approach won’t magically restore youth to all of a patient’s cells in their body; adult cells that have been fully converted back to stem cells via Yamanaka factors lose their identity as blood, heart and skin cells and tend not to regenerate well. A better strategy may be giving patients gene therapy with GDF11 turned on as it has shown similar effects to parabiosis in previous studies by Wagers and others.
Regained Fertility
Scientists are inching ever closer to creating the Fountain of Youth after reversing aging in mice by altering their DNA. The team used an enzyme injection that activated their chromosomes to reverse their aging process; their discovery could ultimately be used as a cure for age-related diseases such as arthritis and cardiovascular issues.
Researchers reactivated the telomerase gene in mice, stopping their chromosomes from shortening and protecting them against cancer cells multiplying. While most animals possess this trait normally, humans often turn it off as an evolutionary compromise to reduce cancer cells’ multiplication. Once activated again, their organs were rejuvenated – shrinking brains grew back in size while coat hair returned its vibrant sheen and fertility returned as expected.
Scientists gave mice a compound called nicotinamide mononucleotide (NMN), which acts as a precursor for NAD+ molecules found in low levels throughout their bodies and that become depleted with age. When these scientists infused NMN into the drinking water of mice, this restored NAD+ to youthful levels; eliminating any senescent cells that accumulate in muscles or other tissues while rejuvenating blood vessels, brain, skin, and organs to make them younger-looking overall.
Reactivating telomerase not only helped rejuvenate old tissue, but it also restored fertility to mice. When researchers bred treated mice with male mice they observed more mature egg cells produced. Although further investigation must be performed to ascertain if any new egg cells generated are fertile yet, the research represents an essential first step toward treating humans.
Scientists aim to make rejuvenating treatments more accessible, possibly by offering it in pill or injection form. Caloric restriction could also achieve similar results; caloric restriction involves restricting calories until your body begins using fat for energy instead of glucose; studies have demonstrated this practice can slow aging and extend lifespan in mice and monkeys; human studies will commence later this year.
