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Weizmann Institute

genetic editing. CRISPR/CAS9. Illustration: depositphotos.com

Corrective editing

A natural editing mechanism of RNA molecules may make it possible to cure genetic diseases
The hourglass of the fetus - a proposal for a hypothesis submitted by the scientists to the scientific journal Cell. "A deep understanding of embryonic development requires consideration of the time dimension." Courtesy of the Weizmann Institute

cell film

The wonderful world where the first embryonic cells are formed is now more accessible to us than ever before
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
Six cyclones at the south pole of Jupiter, as captured by the infrared lens of the Juno probe in February 2017. Beautifully arranged and shaped like a rose cake. Source: NASA

The mystery of Jupiter's cyclones

They are powerful, they are the size of Australia and no one imagined them until a few years ago - what is the secret of the storms at the poles of the largest planet in the solar system?
A section of the digestive system of a Crohn's patient. Illustration: depositphotos.com

The secret is in the texture

Changes in the intercellular texture may predict inflammatory bowel disease
The hollow crystals under a scanning electron microscope

Crystals that eat crystals

From the creator of yo-yo crystals, now comes the next generation - hollow crystals
neural network. Illustration: depositphotos.com

Neurons search for meaning

A new research approach makes it possible to document how the brain learns new rules
neurological disease. Illustration: depositphotos.com

Death on the bypass

Weizmann Institute of Science scientists have uncovered an unusual mechanism of cell death. The findings may lead to new treatments for various diseases
Ovules in early stages of development in the ovary segment of the fruit fly. In green - mitochondrial organelles that are not active, in yellow-red - active organelles

Bacteria are fueled

Weizmann Institute scientists have revealed an effect of the gut bacteria on the body's systems mediated through the supply of essential compounds for energy production in the mitochondria
The Israeli delegation (from right to left): Yara Shulman, Tamar Farr, Nega Friedman and Nicole Grossman. Photo: Future Scientists Center

European Mathematics Champions

Students trained at the Weizmann Institute won the gold and silver medals in the European Mathematics Olympiad for Girls
The triple strategy of the corona: 1. A general decrease in the translation products in the cell; 2. Breakdown of messenger RNA molecules of the cell; 3. Preventing the exit of messenger RNA molecules from the nucleus

The triple of the corona

The scientists of the Weizmann Institute of Science, in partnership with the scientists of the Biological Institute in Nes Ziona, revealed how a unique combination of three mechanisms allows the corona virus to escape the immune system
Fruit bat. Photo: depositphotos.com

Navigate in a big way

A new neural code for navigating large spaces was revealed in the "bat tunnel" at the Weizmann Institute of Science
A XNUMXD model of a network of photosynthetic membranes in a plant, based on electron microscope photographs. Thylakoids (in yellow) are surrounded by parking garage-like structures, consisting of ramps curving to the left (in purple) and to the right (in blue)

Park with minimal effort

How parking lot-like structures are organized that are used to transport substances within the cell
Avocado. Photo: depositphotos.com

A natural food supplement may act as an anti-anxiety agent

Weizmann Institute of Science scientists have shown that the herbal supplement reduces anxiety levels in mice without significant side effects
Mouse brain section. The parts illuminated in red - communication pathways between nerve cells that express the mosquito protein. In blue - the cell nuclei

Mosquito on the head

Weizmann Institute of Science scientists have developed a research tool that will shed new light on communication pathways between nerve cells in the brain
The genetically engineered wild tomatoes grown by Dr. Kazachkova in greenhouses at the Weizmann Institute. "These were the most delicious bitter tomatoes I have ever tasted in my life"

A brief history of the tomato

From the right: Prof. Eli Waxman and Prof. Avishai Gal-Yam

A star dies, a particle is born

Is the origin of a particle that landed at the South Pole in a cosmic event 700 million years old?
Measuring heart muscle cell beats for a few minutes (left) does indeed reveal deviations from the ideal beat rhythm - a beat every second - but when this is done over several hours (right) a new pattern is revealed: slower or faster than average beats that appear in clusters of 10 to 30 minutes

The strange dance of the heart

Scientists at the Weizmann Institute and the Technion have discovered clues to the existence of a slow regulatory mechanism in heart muscle cells designed to regulate the rhythm of their beats, and to ensure that it is as close as possible to a cycle of one beat per second
4D structure of the stemalnotide drug molecule (pink) and calcium ion (green) in the binding pocket of the MCXNUMX receptor

The Hunger Games: the mechanism of action of the switch in the brain responsible for the feeling of satiety

Understanding the mechanism is expected to help in the development of new anti-obesity drugs
Neurons of a mouse under a microscope. An inhibitory neuron (right) and an excitatory neuron (left)

Keep a balanced mind

Networks of nerve cells grown in the laboratory revealed a new regulatory mechanism that maintains a balance between activation and suppression of brain activity
DNA molecule. Image: depositphotos.com

The loom of evolution

A new method makes it possible to locate points of similarity between gene control molecules of different species - from lizards to humans - and thus reveal essential sections that have been preserved throughout evolution
Micro-reservoirs of lipid assemblies (liposomes) dispersed in the bulk of the gel - the diameter of the smallest ones is about 100 nanometers

Inspirational cartilage

Weizmann Institute scientists have created innovative materials inspired by the lubrication model of our joints. The result may be real news for the biomedical industry
On January 3, 2020, smoke from wildfires in southeastern Australia was captured in satellite images of the Pacific Ocean as it moved eastward. Photo: Suomi National Polar-orbiting Partnership

Around the world in 14 days: this is how the haze from the fires in Australia surrounded the world

A mouse fetus grown six days outside the womb. His developing organs were marked with fluorescent genes

Weizmann Institute scientists grew mouse embryos outside the womb

For seven years, through trial and error, fine-tuning and repeated tests, in the laboratory of Prof. Hana, who specializes in embryonic stem cells, they developed a two-stage method that makes it possible to grow normal mouse embryos outside the womb from the initial stages of pregnancy in order to study the different stages of development of the embryo, Something that was not possible in mammals until now
Imaging of a ring-shaped malaria parasite that lives inside a red blood cell and secretes vesicles carrying the S20 proteasome (colorful barrel-like structures)

kills them softly

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