In the 1970 of the 20th century, scientists discovered DNA to copy each round, will lose a DNA fragment at the end, this is the Telomere, it looks like a helmet through "sacrifice" to ensure the integrity of the DNA sequence.But if there is no compensation, after thousands of copies of DNA will eventually shorten or even disappeared, resulting in two things – aging and cancer.Scientists have discovered something called "telomerase" material in the area of Telomere Length even extended play a decisive role.

Recently, Taiwan University, Nankai University and scientists at the University of Michigan by somatic cell nuclear transfer method, successfully from the loss of heterozygosity of telomerase in somatic cells of mice to get telomerase extension and has real growth potential of pluripotent stem cells.This results from both experimental and theoretical levels show that humans "second childhood" is no longer a dream.

From ancient Emperor of not old Elixir, to modern people of raised yan prescriptions, youth or immortality has been is human everlasting not variable of pursuit, on even scientists also spare no effort to to research with "to days again take 500 years" of method, in these research in the we always can see stem cell of figure, so stem cell and aging what has what relationship, it whether is opened inverse growth of a put key does?

Mysteries of aging

Stem cells with age reduced activity and regeneration

What is aging?What is the nature of aging?Aging is the eternal rhythm of life.Hair white, tooth loss, wrinkles appear ... ... This is what we can see, senility, and internal organ function recession, slow reaction, poor memory, resistance weakened ... ... This is the age we can't see.Aging the degeneration of tissue and organ structure and function decrease, its essence is the attenuation of cells and cell decay caused by attenuation of stem cells.So the national stem cell Engineering Research Center said Han Zhongchao, Director: "the nature of aging is the attenuation of the stem cells. ”

People can live to be 100 years old or more, a single cells tend to have longer life span, for example, epithelial cell-28 days to replace once every 27 days, and intestinal mucosal cells is once every 2-3 days.Mature body cells will die due to age or injury, alternatives to them whenever you want, which is the source of these alternatives.They are in the process of human development, will keep their immature State and differentiation potential, when subject to specific chemical stimulation, will perk up, began to proliferation and differentiation into cell types of the body needs to play its due role.This is hidden in some into the crowd of children, usually stay there quietly, once your body needs, you can quickly change, grow up, become adults, as with other adults.

Introduced Han Zhongchao, proliferation and differentiation of stem cells in their ability to totipotency, and versatile stem cells and pluripotent stem cells, with few able to stem cells and stem cells;According to their source organization can be divided into perinatal embryonic stem cells and placenta the umbilical cord stem cells, bone marrow stem cells, stem cell, adipose-derived stem cells and other tissue stem cells;According to its physiological functions can be divided into hematopoietic stem cells, neural stem cells, blood vessels, skin stem cells, and so on.

In an ideal case, which needs to maintain our lives.But the reality is cruel, Chief Scientist Li Yukui that human stem cell research Institute in Ningxia, through years of research in the field of stem cell research consensus is to increase as people age, activity and regeneration of many types of stem cells in the human body is also reduced.Inadequate newborn cells, cells cannot be replaced in a timely manner, resulting in decreased function of all systems of the body.

Rejuvenation

Take the stem cells to save the aging

"If we can avoid recession, correction or delayed stem cell process, in theory, can expect improvements to the aging process. ”Li Yukui said.It seems to want to "rejuvenate" still in stem cells was "seen" anti-aging is using stem cells with their own stem cells is to use someone else's stem cells.

Using someone else's stem cells their aging resistance, the main problems of immune rejection. “Like many Korean dramas have plots, character with leukemia need a bone marrow transplant, but it's hard to find the right match. ”Li Yukui said "crowd are hard to find in exactly matches the immunity of two people, including our loved ones, whether parents, children, brothers and sisters.So a person's cells are usually not directly to another person, except when using drugs to suppress immune rejection, but in that case it's more complicated in clinical. ”

If you borrow someone else's stem cells is difficult to achieve in time, then ask for help rather than cry, from the point of view of Immunology, Autologous stem cells would not be rejected, can survive and play their natural features, using Autologous stem-cell anti-aging natural is best.But Han Zhongchao pointed out that, dang people into old period, its body stem cell of number and function are will reduced, so old Shi from body stem cell, like fat in the of stem cell with left in fat organization long fat, than from extraction out, for other organization of regeneration repair, like injection to face Shang, may will improved facial aging, but this for against human overall of aging somewhat robbing Peter to pay Paul of means, and also seems to somewhat bucket.

If old age using its stem-cell anti-aging is robbing Peter to pay Paul, the bucket, then we can part stored stem cells at a young age until old age against aging?Li Yukui says, this is technically feasible, but a cell type can play a limited role, such as when saving a young, fat stem cells to be injected into the skin in old age, it only makes the skin look better, no effect on other organs;Save when implanted in hematopoietic stem cells, such as old age and younger can make your blood system, also within a certain period of life more exuberant, but if you want to keep that energy needs every six months or one year injection, high cost;In addition, save stem cells cannot substitute for solid visceral organs function.

Han Zhongchao admitted that himself when he was young, fat stem cells and endometrial stem cells save some for future use as a policy, but how to save at present there are still some problems, they conduct research on working now.

Look at it this way, when stem cells are not enough, stem cells do not play when you are young, with stem cell aging appears to be at a dead end, but induced pluripotent stem cells (IPS cells for short) appeared to break out of this quagmire brought a glimmer of hope.Laboratory artificial induction of IPS cells is method of differentiation of cellular reprogramming has been transformed in all respects very close to pluripotent stem cells and embryonic stem cells, is a cellular level "rejuvenated" differentiation of the cells can generate a variety of cells, can develop into a complete individual.

Fog Flower

"Young again" how far is it from us

With IPS cells is that we will "rejuvenate" is very near it?

Li Yukui pointed out that IPS technology is still facing a lot of problems.First will mature of somatic induced into IPS cell this process only in body outside occurred, induced success Hou also is to will these stem cell entered to human internal to works, some parts can directly injection back, like skin Xia, but some parts is cannot directly injection back of, and some parts works not to single cell of form, like heart, it is a full of organ in works, put stem cell implanted in only repair some disease injury.Want the whole function of the heart conditions, can only use their own stem cells to grow a new heart, such as the aging of the heart, then new heart instead.

Secondly, the IPS cells were first Shinya Yamanaka in Japan in 2006, the use of viral vectors 4 transcription factor (Oct4, Sox2, Klf4 and c-Myc) combination of differentiation of cells, to reprogram and find out.If the cell already has a virus, into the human body and of course it is not safe, medical management is not allowed.So people can study in recent years with something else instead of viruses, scientists are trying to use small molecules to replace virus, small molecule metabolism quickly into the body quickly metabolized, so no major safety problems.

But the IPS cells created a security, there is no way to improve this is it has the risk of tumors.Proliferation of IPS cells can be infinitely divided, and it has the potential to generate many different types of cells.The IPS cells into the human body, once the environment it will continue with the split and formation of tumor cells to stop dividing and therefore is more likely to generate IPS cells tumor.So the basic bottom line is that you must turned it into not proliferation of cell types in vitro, these cells can then be implanted.Now scientists are doing work in this area, for example by generating insulin-producing cells.But so far, no one can do this can ensure that the IPS cells into not proliferation of cell types do not have the ability to generate tumors, but also to ensure that no proliferation cells really work.Li Yukui explained said, research personnel do cell not do single of cell, are is Shang million, and do even Shang billion of cell, such on faced a problem: How can guarantee this Shang million, and do even Shang billion of IPS cell each a a are change into has cannot proliferation of cell, whenever has a cell no change, once implanted human it on has may unlimited proliferation became tumor.Because of these technical issues so far have not fully resolved, so it limits the application of IPS cells in clinical practice.

So, in relation to current technology, expected to pass the stem cell technology to "rejuvenate", and is a can't see the end of hope.Li Yukui, if "second childhood" refers to the removal of wrinkles, so is easy to do with stem cells;If the "second childhood" refers to the replacement of one's organs and tissues, to make the human body is young, it needs at least a few decades of time;But if "second childhood" refers to the full range of a person back to a younger State, now seems a long way off.Han Zhongchao says about this, although the use of stem cells fully realized "second childhood" is impossible, but prolong life, improve health and quality of life is possible, and I believe it can be achieved very quickly.