Hematopoietic stem cell differentiation

One of the most important ways to treat leukemia is to transplant hematopoietic stem cells, mainly because hematopoietic stem cells have hematopoietic functions and can help the human body reconstruct hematopoietic and immune functions. Many leukemia patients are given new life in this way. So how many types of cells can hematopoietic stem cells differentiate into? This article briefly explains the issues related to hematopoietic stem cell differentiation, hoping to be helpful to patients and friends.

1. What types of cells do hematopoietic stem cells differentiate into?

Hematopoietic stem cells have the potential to self-regenerate and differentiate into various mature blood cells for a long time. They are adult stem cells in the blood system and a heterogeneous group. Hematopoietic stem cells need to replenish the various mature cell components of the blood system in a timely manner according to the body's physiological needs. At the same time, under stress conditions such as injury and inflammation, hematopoietic stem cells also play a role in regulating and maintaining the physiological balance of various cellular components of the blood system in the body.

Hematopoietic stem cells can differentiate into bone marrow stem cells, lymphoid stem cells and pluripotent stem cells. Bone marrow stem cells contain colonies of erythrocytes, megakaryocytes, and macrophages (granulocyte and monocytic cells). Lymphoid stem cells are the common ancestor cells of T and B cells. Unipotent stem cells are a type of stem cells that have the ability to differentiate into specific cell lineages, also known as progenitor cells. For example, spleen colonies cannot be formed during in vivo transplantation, but in the presence of certain hematopoietic factors, they can be cultured in vitro and form cell colonies containing mature daughter cells.

2. Source of hematopoietic stem cells

Hematopoietic stem cells come from bone marrow, peripheral blood, and umbilical cord blood. Compared with the first two, umbilical cord blood hematopoietic stem cells are easier to collect and have abundant sources, making them a valuable life resource. Umbilical cord blood hematopoietic stem cells have been used in clinical treatment for more than 20 years. It has been clinically proven that they can rebuild the hematopoietic system and immune system and treat a variety of diseases. Moreover, self-stored umbilical cord blood has a better therapeutic effect than autologous transplantation. Self-stored umbilical cord blood does not require matching and can be taken out at any time. Because it is stored and used by the patient himself and there is no rejection reaction, the treatment success rate is high. At the same time, self-stored umbilical cord blood generally comes with medical insurance, which not only gains treatment time but also reduces financial pressure.

3. How many hematopoietic stem cells can save lives?

Bone marrow transplantation requires hematopoietic stem cells in the human body. The bone marrow of an adult weighs about 3 kilograms. A donor providing 10 grams of bone marrow hematopoietic stem cells can save the life of a leukemia patient. The human body has a strong regenerative capacity for hematopoietic stem cells. Under normal circumstances, various cells in the human body are constantly metabolizing every day, undergoing a cycle of generation, aging, and death. After blood loss or donation of hematopoietic stem cells, the bone marrow can be stimulated to accelerate hematopoiesis, and within 1-2 weeks, various blood cells in the blood return to their original levels. Therefore, donating hematopoietic stem cells will not affect your health.

Classification of hematopoietic stem cell transplantation

1. There are many classification methods for hematopoietic stem cell transplantation. Hematopoietic stem cells come from oneself or others, which are called autologous hematopoietic stem cell transplantation and allogeneic (also known as allogeneic) hematopoietic stem cell transplantation. Among them, allogeneic hematopoietic stem cell transplantation is divided into blood-related donor hematopoietic stem cell transplantation and unrelated donor hematopoietic stem cell transplantation (i.e. unrelated transplantation) according to whether the donor and the patient are related. It is divided into peripheral blood hematopoietic stem cell transplantation, bone marrow transplantation and umbilical cord blood hematopoietic stem cell transplantation according to the type of graft.

2. In autologous hematopoietic stem cell transplantation, the hematopoietic stem cells are derived from the patient's own body, so graft rejection and graft-versus-host disease will not occur, there are few transplantation complications, and there is no restriction on donor sources. The transplantation-related mortality rate is low, and the quality of life after transplantation is good. However, due to the lack of graft-anti-tumor effect and the possibility of residual tumor cells mixed in the graft, the recurrence rate is high.

3. In allogeneic hematopoietic stem cell transplantation , hematopoietic stem cells are derived from normal donors, are not contaminated by tumor cells, and the graft has an immune anti-tumor effect. Therefore, the recurrence rate is low, the long-term disease-free survival rate (which can also be understood as the cure rate) is high, and the indications are wide. It is even the only cure for some diseases. However, the donor source is limited, graft-versus-host disease is prone to occur, and there are many transplantation complications, resulting in a high transplant-related mortality rate. Patients need to use immunosuppressants for a long time, and the quality of life of long-term survivors may be poor.

The role of hematopoietic stem cells

1. Hematopoietic stem cells have two important characteristics: high self-renewal or self-replication ability , and the ability to differentiate into all types of blood cells. Hematopoietic stem cells divide asymmetrically: one cell divides into two cells. One of the cells still retains all the biological characteristics of stem cells, thereby keeping the number of stem cells in the body relatively stable. This is stem cell self-renewal. The other one further proliferates and differentiates into various blood cells, precursor cells and mature blood cells, and is released into the peripheral blood to perform their respective tasks until they age and die. This process continues continuously.

2. Hematopoietic stem cells are progenitor cells that can self-renew, have strong differentiation, development and regeneration capabilities, and can produce various types of blood cells. Hematopoietic stem cells originate from red bone marrow and can migrate to the peripheral blood circulation through the bloodstream. The hematopoietic function will not be damaged by blood donation and hematopoietic stem cell donation.

3. Use bone marrow transplantation to treat blood system diseases by transplanting the donor's hematopoietic stem cells into the recipient's body to restore the recipient's normal hematopoietic and immune functions.