Can human tissue or organs regenerate completely to achieve eternal life?

The factors that understand aging and life expectancy have always been a topic that scientists want to overcome them. From the legend of Qin Shihuang in ancient times, to exploring functional drugs with anti -aging and extended life in modern times, it shows people's interest in eternal life.

With the improvement of medical progress and living conditions, modern people already have a longer life span. Someone will definitely want to ask, if human tissue or organs can be completely regenerated, can we live forever?

Most creatures inevitably experience the elderly and death. If we want to live forever, we need to stop the body aging. There are some magical animals in nature that do not have such distress. We hope to learn from them from them.

How can humans get "longevity"?

Water pupa, vortex and other creatures have extraordinary regeneration methods (Figure 1). They are mainly composed of stem cells, constantly splitting new cells, while replacing aging cells at the same time, and new cells that are constantly generated can keep water.

Figure 1 The vortex can grow new eyes after removing the eyes (picture source: reference materials [1])

But this does not mean that humans can copy the secrets of "becoming young". The water is very small, with a body length of only 10 mm and no organs. This is impossible for humans with abnormally complicated body structures. We cannot simply abandon aging cells as well as water. We need these differential cells to play their functions.

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For example, the neurons in the brain are responsible for transmitting information. We do not want the neurons of these tasks to be replaced by the continuous sources of neural stem cells, otherwise we will lose their memory.

In fact, humans also have stem cells that can be repaired and even regenerate tissue. For example, stem cells in the liver can be proliferated and mature cells can be proliferated without damage. However, the human body is not like water crickets, and it is almost completely composed of stem cells.

This is mainly because humans need to differentiate cells to complete more work. For example, highly specialized liver cells take on many tasks of this organ, including storage vitamins and minerals, removing toxins, and helping to regulate fats and sugar in the blood.

We let cells have a certain function, but the cost of function is that cells can lose the ability to divide, and when cells aging, our body is also aging. Surprisingly, in 2006, Professor Professor of the Nobel Prize in Japan found that the induced multi -energy stem cells (IPSCS) can induce differentiated body cell dewlating, and can also be divided into neurotic cells, myocardial cells, liver cells, etc. , Realize the desire of cells to "return to old".

At present, there are three main methods for promoting tissue regeneration: replenish tissue with exogenous stem cells or ancestral cells; chemical stimulation of in -situ stem cells amplification, differentiation, and/or body cell conversion; Essence In animal models, these methods can alleviate a variety of aging syndrome, including neurodegeneration, vascular degeneration, myocardial infarction, and osteoarthritis.

Progress of stem cell technology can improve the method of repairing body damage. For example, the replacement of myocardial cells in the heart of normal mammals is very slow. In contrast, the fetal heart still has immature myocardial cells, which has considerable regeneration potential.

Based on this, the research and use of YANPU Chen et al. Including transcription factors, including OCT4, SOX2, KLF4, and C-MYC (OSKM) specific induction of adult myocardial cells, giving adult heart regeneration capabilities.

It can be understood in the application of the disease that in the state of disease before the myocardial infarction and the infarction period, the short -term improvement of OSKM factor expression transfers and re -programming techniques induces mammalian myocyte cell regeneration, improve myocardial damage and improve cardiac function (Figure 3) Essence

Figure 3: de -differentiation and re -programming can induce mammalian heart regeneration, blue shows fibrous scar tissue, red shows healthy myocardium (picture source: reference material [3])

In another study, Stamm C et al. Promote the patient's myocardial regeneration by entering the method of entering autologous bone marrow stem cells, and also achieved a certain clinical effect (Figure 4).

Figure 4: Promote patients' myocardial regeneration by entering the method of transplantation of autologous bone marrow stem cells (picture source: reference materials [4])

With the advancement of technology, the treatment strategies of pancreas regeneration and repair have also been further improved. At present, the most advanced technology of creating functional human insulin secretion cells is also the only technology to enter clinical trials, which is derived from the human multi -capable stem cells (Figure 5).

Figure 5: The treatment strategy of pancreatic regeneration and repair (picture source: reference materials [5])

"Changsheng" technical breakthrough and bottleneck

Regenerative medicine is widely used in disease treatment and is known as a weapon to resist aging, but why did stem cell therapy have not been clinically promoted and became a ring in traditional treatment?

First of all, safety is the main problem. After the cell purification, a small amount of pollution -uniminaged cells may remain, and may lead to the formation of teratoma.

Second, the same type of album rejection is a problem that has not been solved. The mechanism of transplantation exclusion reactions, especially the identification mechanism of the same species of antigen and the molecular mechanism of chronic migrant migration, has not yet been fully clarified.

Third, the main reason is that stem cells are live cells. Its customized treatment determines that it cannot have strict clinical trials, standardized processes, and a large number of production as traditional drugs. A big bottleneck. The human body is an organic whole, just like a car. After years of use, a brand -new car has gradually occurred in various parts. If it is not maintained in time, the car will shorten the service life.

Each "parts" have their own use period, and they are also serialized. If human tissues or organs can be completely regenerated, can they replace damaged "tissue parts" like cars to eternal life? The answer may be negative.

Although some animals, such as vortex and water, can theoretically perform endless regeneration cycles, but the health of most animals will gradually decrease and eventually die. In normal human body, the stem cells that have been transplanted or transplanted have the significant ability to update and differentiate themselves. This ability will play a key role in the internal environmental balance and repair after their tissue and organs damage or environmental injury.

However, the transplantation effect varies from person to person. The maintenance and function play after transplantation also needs to be clear. Treatment will affect the effectiveness of cell therapy due to the patient's own conditions. As well as organizational exclusion faced during the transplantation, if the local and circulating factors of the balance between self -renewal and differentiation have changed, transplant cells may not be able to maintain the stability of the tissue and play a role.

In addition, organ regeneration does not solve all medical problems.

Given the biometinity of the cell itself, the complexity of cell therapy is beyond imagination. For patients, there may be problems with some diseases and pathological characteristics of diseases, complicated micro -ring in the lesion area, and unclear impact on cell safety and distribution in specific diseases.

Therefore, regeneration medicine may not be able to solve all the health problems of the patient, which also means that it cannot solve all problems by transplantation of a single cell. It must also be matched with other treatment methods. Like cancer treatment, in addition to surgical resection, chemotherapy, target targets, target targets may also be combined with chemotherapy and targets. Treatment and immunotherapy can overcome the disease.

However, scientists are also trying to find a way to improve improvement. By combining genetic engineering technology, cell gene modification and editing can improve the ability of cells to apply to tissue repair and disease treatment.

In the end, we must admit it, and I hope that readers can keep in mind that regeneration medicine is only one of many disease treatment methods and cannot cure all diseases. When you encounter a scam that boasts of regeneration medicine, you must stay away!

Produced: Popular Science China

Author: Liu Boan

Producer: China Science Popularization Expo

Edit: Wang Tingting

The China Science Popularization Expo is the Science Popular Science Platform of the Chinese Academy of Sciences. It is sponsored by the Computer Network Information Center of the Chinese Academy of Sciences. Relying on the high -end scientific resources of the Chinese Academy of Sciences, it is committed to spreading cutting -edge scientific knowledge and providing fun science and education services.

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