Reversed the ageing process in mice – now for humans....
It a claim to be a step closer to reversing the ageing process after rejuvenating worn out organs in elderly mice. The experimental treatment developed by researchers at the Dana-Farber Cancer Institute, Harvard Medical School, turned weak and feeble old mice into healthy animals by regenerating their aged bodies.
The surprise recovery of the animals has raised hopes, that it may be possible to achieve a similar feat in humans – or at least to slow down the ageing process.
"This could lead to strategies that enhance the regenerative potential of organs as individuals age and so increase their quality of life. Whether it serves to increase longevity is a question we are not yet in a position to answer."
The ageing process is poorly understood, but it is known , it is caused by many factors. Highly reactive particles called free radicals are made naturally in the body and cause damage to cells, while smoking, ultraviolet light and other environmental factors contribute to ageing.
There is a process called telomere shortening. Most cells in the body contain 23 pairs of chromosomes, which carry our DNA. At the ends of each chromosome is a protective cap called a telomere. Each time a cell divides, the telomeres are snipped shorter, until eventually they stop working and the cell dies or goes into a suspended state called "senescence". The process is behind much of the wear and tear associated with ageing.
A genetically manipulated mice that lacked an enzyme called telomerase that stops telomeres getting shorter. Without the enzyme, the mice aged prematurely and suffered ailments, including a poor sense of smell, smaller brain size, infertility and damaged intestines and spleens. But when the mice was injections to reactivate the enzyme, it repaired the damaged tissues and reversed the signs of ageing.
"These were severely aged animals, but after a month of treatment they showed a substantial restoration, including the growth of new neurons in their brains,"
Repeating the trick in humans will be more difficult. Mice make telomerase throughout their lives, but the enzyme is switched off in adult humans, an evolutionary compromise that stops cells growing out of control and turning into cancer. Raising levels of telomerase in people might slow the ageing process, but it makes the risk of cancer soar.
DePinho, a scientist in HARVARD MEDICAL SCHOOL said the treatment might be safe in humans if it were given periodically and only to younger people who do not have tiny clumps of cancer cells already living, unnoticed, in their bodies.
David Kipling, who studies ageing at Cardiff University, said: "The goal for human tissue 'rejuvenation' would be to remove senescent cells, or else compensate for the deleterious effects they have on tissues and organs. Although this is a fascinating study, it must be remembered that mice are not little men, particularly with regard to their telomeres, and it remains unclear whether a similar telomerase reactivation in adult humans would lead to the removal of senescent cells."
It is seen that none of mice developed cancer after the treatment. so it has been a big query, whether it extends the lifespan of mice or enables them to live healthier lives into old age.
"The key question is what might this mean for human therapies against age-related diseases? While there is some evidence that telomere erosion contributes to age-associated human pathology, it is surely not the only, or even dominant, cause, as it appears to be in mice engineered to lack telomerase. Furthermore, there is the ever-present anxiety that telomerase reactivation is a hallmark of most human cancers." .....
It a claim to be a step closer to reversing the ageing process after rejuvenating worn out organs in elderly mice. The experimental treatment developed by researchers at the Dana-Farber Cancer Institute, Harvard Medical School, turned weak and feeble old mice into healthy animals by regenerating their aged bodies.
The surprise recovery of the animals has raised hopes, that it may be possible to achieve a similar feat in humans – or at least to slow down the ageing process.
"This could lead to strategies that enhance the regenerative potential of organs as individuals age and so increase their quality of life. Whether it serves to increase longevity is a question we are not yet in a position to answer."
The ageing process is poorly understood, but it is known , it is caused by many factors. Highly reactive particles called free radicals are made naturally in the body and cause damage to cells, while smoking, ultraviolet light and other environmental factors contribute to ageing.
There is a process called telomere shortening. Most cells in the body contain 23 pairs of chromosomes, which carry our DNA. At the ends of each chromosome is a protective cap called a telomere. Each time a cell divides, the telomeres are snipped shorter, until eventually they stop working and the cell dies or goes into a suspended state called "senescence". The process is behind much of the wear and tear associated with ageing.
A genetically manipulated mice that lacked an enzyme called telomerase that stops telomeres getting shorter. Without the enzyme, the mice aged prematurely and suffered ailments, including a poor sense of smell, smaller brain size, infertility and damaged intestines and spleens. But when the mice was injections to reactivate the enzyme, it repaired the damaged tissues and reversed the signs of ageing.
"These were severely aged animals, but after a month of treatment they showed a substantial restoration, including the growth of new neurons in their brains,"
Repeating the trick in humans will be more difficult. Mice make telomerase throughout their lives, but the enzyme is switched off in adult humans, an evolutionary compromise that stops cells growing out of control and turning into cancer. Raising levels of telomerase in people might slow the ageing process, but it makes the risk of cancer soar.
DePinho, a scientist in HARVARD MEDICAL SCHOOL said the treatment might be safe in humans if it were given periodically and only to younger people who do not have tiny clumps of cancer cells already living, unnoticed, in their bodies.
David Kipling, who studies ageing at Cardiff University, said: "The goal for human tissue 'rejuvenation' would be to remove senescent cells, or else compensate for the deleterious effects they have on tissues and organs. Although this is a fascinating study, it must be remembered that mice are not little men, particularly with regard to their telomeres, and it remains unclear whether a similar telomerase reactivation in adult humans would lead to the removal of senescent cells."
It is seen that none of mice developed cancer after the treatment. so it has been a big query, whether it extends the lifespan of mice or enables them to live healthier lives into old age.
"The key question is what might this mean for human therapies against age-related diseases? While there is some evidence that telomere erosion contributes to age-associated human pathology, it is surely not the only, or even dominant, cause, as it appears to be in mice engineered to lack telomerase. Furthermore, there is the ever-present anxiety that telomerase reactivation is a hallmark of most human cancers." .....
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