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Stem cells

Histological sections of the leg muscles without injury (left) and five days after it (center, right) in a control mouse and a transgenic mouse. It can be seen that the area of ​​the muscle fibers that develop after the injury is smaller in the transgenic mouse, which indicates a disturbance in the differentiation of the stem cells into muscle cells

overcome the damage

Researchers have discovered that two epigenetic events (removing and adding methyl from DNA) lead to the differentiation of stem cells into muscle cells and thus to the regeneration and healing of muscles after their injury
An artificial model of a human embryo in a developmental stage corresponding to day 12. The upper elliptical structure is the part that will become an embryo including the amniotic sac above it; The lower structure is the yolk sac. The interface between the two structures is an essential element for embryonic development in humans. Both parts are surrounded by a layer of cells which will become the placenta

A human embryo without the need for a sperm egg or uterus

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A pregnancy test detected the fetus in the test tube. The artificial models developed from stem cells - without egg, sperm or uterus - and grew in the laboratory until day 14
Illustration: Sally Neve

A breakthrough in the treatment of herniated disc

Tissue engineering offers a solution for the treatment of disc herniations: an implant that combines synthetic hydrogel and living cartilage cells
A "ghost" heart is a pig heart that has been prepared so that it can be transplanted into humans. Provided by Doris Taylor

"Ghost" hearts from a pig and the patient's stem cells will replace the need for heart donations

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Today, patients needing a heart transplant have to join a waiting list, and hearts become available when someone else dies. Because there are not enough hearts, only critically ill patients are put on the waiting list
Damage to the motor nerves in Duchenne patients. Illustration: depositphotos.com

Improving the function of the heart muscle in Duchenne patients

Producing heart cells from skin cells made it possible to discover defects that lead to heart failure
Stem cells. Illustration: depositphotos.com

For the first time, human skin cells can be directly transformed into cells of a placenta

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A research team led by Prof. Yossi Buganim from the School of Medicine of the Hebrew University succeeded in reprogramming human skin cells into functional placental cells so that there is no need to extract stem cells from embryos
Mice. Illustration: depositphotos.com

Mice with two fathers: Scientists create eggs from male cells

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The researchers behind the new study were able to create baby mice with genetic material from two males without any genetic changes. They achieved this by using stem cells to create primordial germ cells (PGCs), which differentiate into sperm and egg.
A discovery by the institute's scientists may make it possible to increase the amount of stem cells in bone marrow transplants - and improve their chances of success You are here Homepage > Publications > Science news in a friendly language > New blood flows Share Tags Idit Shehartai stem cell immunology bone marrow transplant stem cell transplant The blood in our arteries is constantly renewed Thanks to a small and inexhaustible supply of stem cells in the bone marrow that ensure a continuous supply of fresh blood cells. In bone marrow transplants, these stem cells are harvested from donors and transferred to patients who need them, for example leukemia patients or other types of blood cancer. However, the amount of stem cells is not always sufficient and there is currently no way to grow these cells in the laboratory without them losing their unique properties. The scientists of the Weizmann Institute of Science recently discovered a method that may make it possible to increase the amount of stem cells for transplantation, thus improving the chances of success of bone marrow transplants. Prof. Idit Shahar from the Department of Immunology and her group members are researching a receptor called CD74 which is found on the membranes of blood cells. After in a previous study, the scientists discovered that this receptor improves the survival ability of type B white blood cells - they wanted to check if the receptor is also used in a similar way in the stem cells in the bone marrow. To their surprise, it turned out that in the stem cells its action is completely opposite: it initiates a chain of biochemical reactions leading to the death of the cells. From the right: Hadas Levinsky, Dr. Shirley Becker-Herman, Prof. Idit Shahar and Keren David. Down to their bone marrow This fact was revealed after, in one of the experiments, larger than normal amounts of stem cells were found in the bone marrow of genetically modified mice without the CD74 receptor. In other words, disabling the receptor prevented the cells from dying and allowed them to survive for a long time and accumulate. How is it possible that the same receptor performs completely different actions in two types of cells? The reason for this probably lies in the conditions, for example the oxygen levels, or the different environments in which the cells operate - the blood circulation in the case of B cells and the bone marrow in the case of the stem cells. Later, the scientists implanted in bone marrow-deficient mice doses that included identical amounts of normal stem cells and stem cells without CD74. They were amazed to discover that the cells without the receptor were absorbed better, multiplied quickly and in a short time filled the entire bone marrow. In the next step, the scientists conducted a "competition" between the two types of cells - they performed a series of experiments in which they gradually increased the amount of normal stem cells at the expense of the engineered cells. The results were unequivocal: even when the cells without the receptor constituted only one tenth of the total number of cells in the transplanted portion, they were still absorbed better, divided rapidly and were the ones that eventually filled most of the bone marrow. In additional experiments, in mice that underwent chemotherapy treatments - similar to those given to cancer patients - it became clear that mice without CD74 survived and restored their immune system more efficiently than the control mice. "The research may help produce stem cells for transplantation in larger quantities and of higher quality" Finally, the scientists found that an antibody that blocks the active site of the CD74 receptor does indeed cause the stem cells to accumulate in large quantities both in laboratory vessels and in the skeleton of mice. In addition, they showed that blocking CD74 in stem cells taken from humans led to molecular changes similar to those observed in mice. These findings indicate that blocking the receptor may be relevant to bone marrow transplantation in humans. When there is no XNUMX% matching donor for a patient in need of a bone marrow transplant, it is sometimes possible to overcome the lack of a complete match by using huge doses of stem cells. Also, sometimes the source of cells for transplantation is umbilical cord blood, which contains a small amount of these cells. In both cases, increasing the amount of stem cells is essential. "Our research may help produce stem cells for transplantation in larger quantities and of higher quality," concludes Prof. Shahar.

Infusing new blood

A discovery by the institute's scientists may make it possible to increase the amount of stem cells in bone marrow transplants - and improve their chances of success
Freezing of stem cells that became biological drugs at the Pluristem plant in Haifa, 26/10/214. Photo: Avi Blizovsky

Pluristem treated the first three corona patients in Israel with stem cells as part of compassionate care

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Creating a model of atrial fibrillation in the engineered atrial tissue, and mapping the electrical activity in this model. In the left column, a disturbance resulting from the formation of "rotors" is shown, and in the right column - the cessation of the disturbance and a return to a normal rhythm through the use of existing and new drugs. Photo: Nitzan Zohar, Technion Spokesperson

XNUMXD engineered heart tissue that will be used to personalize drugs and develop new treatments

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Stem cells differentiate into neurons and an unsorted stem cell colony. Prof. Yishai Avior, Hebrew University

Fetal stem cells that are used to treat diseases and in research - may contain cancerous mutations

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Confocal microscope photograph: cross section of the adult fly intestine - stem cells undergoing impaired differentiation. The team of Prof. Amir Orin, the Technion

New aspects of the mechanism that preserves the identity of mature body cells

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The first multicellular animals were created from a collection of cells. Illustration: shutterstock

A new fundamental discovery in evolution: the first multicellular animals evolved from a collection of stem cells and not from sponges

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Mouse hematopoietic stem cells in culture. Right: the cells did not differentiate into blood cells after the activity of Mettl3 was disabled in them. On the left: the non-engineered stem cells differentiated in a short time into mature blood cells of different types

Kill the cancerous blood cells - without harming the healthy stem cells

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Mouse embryonic stem cells were observed using a spinning disk confocal microscope. The levels of the protein that prevents stem cells from differentiating (green) decrease in the presence of high levels of another protein (purple) that causes mitochondria to elongate

The elongation of mitochondria in embryonic stem cells affects the process of differentiation into the various body tissues

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Two-dimensional nanoparticles that interact with stem cells and direct their differentiation into cartilage cells [Courtesy: Texas A&M University College of Engineering]

An innovative medical approach to the treatment of osteoarthritis

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Dr. Michael Miliavsky. Photo: Tel Aviv University spokesperson

Researchers at Tel Aviv University have developed a technology to identify cancer stem cells that cause blood cancer, and found an effective drug against them

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Cancer cells drift in the bloodstream. Illustration: shutterstock

The first blood plants: this year ten people will receive synthetic blood transfusions

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The mini-intestine growing in the plate (cells divide in crypts painted in red, and in green - cells in the niche that support the stem cells)

The ARTS protein is responsible for critical processes in intestinal diseases

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The main cells in the brain: in yellow neurons (nerve cells), in orange: astrocytes, gray: oligodendrocytes, in white, microglia or brain cells. Illustration: shutterstock

Stem Cell Medicines acquires the rights to develop a drug for autism developed at Tel Aviv University

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Division of stem cells in the bone marrow. A fresh supply of billions of cells daily. Photo: Dr. Karin Golan, Weizmann Institute

The production of cells in the bone marrow is affected by the day and night cycles

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Sperm cells. Illustration: shutterstock

Researchers have found a way to grow and produce human sperm cells in culture

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A robot in a biological laboratory. Illustration: shutterstock

The robots that grow human mini-organs in laboratories

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Biotechnological laboratory. Illustration: shutterstock

Cancer treatment succeeds in reprogramming cancer cells and returning them to a pre-cancerous state

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neurons. Illustration: ZEISS Microscopy.

Researchers discovered dopamine-stimulating proteins to treat Parkinson's

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