About Us
Founded in 1944, the American Committee for the Weizmann Institute of Science develops philanthropic support for the Weizmann Institute in Israel, and advances its mission of science for the benefit of humanity.
https://weizmann-usa.org/news-media/in-the-news/no-cell-left-behind-mapping-the-human-body/
Jul 11, 2017... Imagine walking into the doctor’s office, preparing for the worst. The doctor brings up surgery, vaguely motions to a chart on the wall, and points to certain printed organs. But what if he could show you which cells needed removal, what they looked like, and even why they caused your condition? Scientists may now have the means to determine the precise cellular structure of human organs, which could improve researchers’, doctors’, and patients’ understanding of human diseases.Researchers at the Weizmann institute in Israel, led by Ido Amit and Shalev Itzkovitz, reconstructed the cellular structure of the liver in a Nature article published in February 2017. Their research team is a part of the Human Cell Atlas project, whose mission is to “create comprehensive reference maps of all human cells.” These maps, which organize cells by their genomes, will help researchers and medical professionals to better understand how and why cellular structures lead to organ functions.While researchers have long been interested in cellular maps, the ability to determine the locations of cells and their genomic blueprints has been limited by available molecular biology techniques. Sequencing DNA, the alphabet of our genes, has traditionally been expensive and time-consuming. The cells must be extracted from the body before DNA can be harvested, destroying the spatial location of the cell.Researchers also want to know the RNA profile of different cell types, which would reveal which genes are expressed as proteins. Ultimately, they would like to determine the proteome, or the entire set of expressed proteins, of each type of cell. However, this is still an emerging research field. Determining the levels of just 50 proteins in a cell is already a cumbersome task, let alone of the thousands of proteins actually present. The RNA profile serves as a simpler proxy for the proteome because modern advances in molecular biology, such as Next Generation Sequencing, have allowed researchers to quickly determine the DNA and RNA content of a cell. However, this process still requires the isolation of each cell prior to sequencing and sacrifices the cell’s spatial context in exchange for its genomic content.The researchers at the Weizmann Institute were able to overcome this problem by combining the RNA sequencing results from Next Generation Sequencing with cellular locations determined by fluorescence. They then used computer algorithms to determine which RNA profile corresponded to which cellular location.To do this, the researchers first determined the locations of several different cell types in the liver. One of the largest organs in the body, the liver is responsible for digesting nutrients and detoxifying dangerous substances. The cells in a subunit of the liver are differentiated into layers expanding radially from a central vein, and those closest to the vein are most accessible to the nutrients and oxygen carried in the bloodstream. The cells in each layer express a set of different genes, so the RNA profiles, which tell us which genes are expressed, differ between each layer.They then identified six “landmark” genes that are known to be expressed differently in each layer. They designed probes that would bind to each gene’s specific mRNA, a type of RNA that is translated into protein. With a technique called single molecule fluorescent in situ hybridization, the researchers determined which cells in each layer expressed which genes. “Each little dot corresponds to an mRNA,” said Thomas Pollard, a professor of Molecular, Cellular and Developmental Biology at Yale. A brighter dot signifies more copies of that gene’s mRNA. The Weizmann researchers now had data on six of the thousands of genes expressed in liver cells.The next step was to find the entire RNA expression profile—the complete collection of different RNAs—for each layer. They turned to single cell-RNA sequencing to quickly identify the thousands of different RNAs within each cell. In this technique, RNA from each cell is harvested and amplified many times to allow it to be sequenced. Armed with this knowledge, the researchers compared the RNA expression levels of the six genes measured earlier. Since they knew the approximate expression levels of six of the genes from the previous experiment, they could match the RNA profiles to each cellular location from these six genes. For example, if landmark gene A was expressed highly in one RNA profile, then it would have to had come from a cell from a layer that fluoresced brightly for gene A’s mRNA.Their maps showed that of the 7,277 genes expressed in liver cells, 3,496 of them vary non-randomly by spatial location. For example, genes in energy-demanding pathways were expressed the most near the central vein, which provides the cells with oxygen and nutrients. Cells near the vein also strongly expressed genes coding for secreted proteins; their placement near the vein allows cells to efficiently transport their secretory proteins through the vein. This finding confirmed the long-standing biological principle that structure leads to function.Researchers would still like to dig further and determine the proteomes of different cells in addition to RNA profiles. Knowing which proteins are expressed at what levels in each cell would further illustrate the role of each cell in our body. “RNA expression profiles don’t give you protein levels,” Pollard explained. “Sometimes low mRNA levels can give you a lot of proteins, or a lot of mRNA can give you a few proteins. It also depends on the lifespan of the protein.”Scott Holley, another professor of Molecular, Cellular and Developmental Biology at Yale, agrees. “It’s a caveat of the experiment,” Holley said. However, identifying the thousands of proteins in each cell requires thousands of antibodies to recognize and bind to each protein. This can be very difficult because researchers still do not know every protein our cells make. Finding every protein and producing antibodies for each one could take years.Moreover, reference maps for other organs may not prove so easy. The cells in the liver are arranged in concentric circles, allowing the Weizmann researchers to assign cellular locations with as few as six genes. More complex structures, such as the brain, do not have such a simple geometry, making the reference map more complicated.Nevertheless, cell maps will give researchers and medical professionals a new outlook on the human body. Embryo cell lineage mapping, a related technique used since the early 20th century, was a successful predecessor: it revealed the development of each cell in the embryos of various organisms. It has already provided important information about how organs and structures develop and given researchers the ability to manipulate embryonic organisms.The Human Cell Atlas project hopes to continue to empower scientists and medical professionals, especially in cancer treatment. Rather than generalizing cancer to a whole organ, such as breast or lung cancer, this new blueprint may allow doctors and scientists to understand the inherent variation within each tumor. They can then more accurately monitor tumor growth and identify which therapy would be best suited for which cancers.The lab at Weizmann is but one of many groups attempting to provide researchers with detailed maps of where each of the thousands of types of cells is located in the human body. The project is an international effort, with member laboratories in the United States, United Kingdom, Sweden, and Israel. Meanwhile, other mapping projects are also in the works. Cancer Research UK announced last month that a project to create an interactive virtual-reality map of breast cancers would receive up to $25 million. In the United States, the National Institute of Mental Health is preparing to announce grant awards for mapping mouse brains later this year.There is still a long way to go to map out all 37 trillion cells in the human body, but with these advances in sequencing and imaging, it has never been easier to see our cells where they belong.
https://weizmann-usa.org/news-media/in-the-news/the-enzyme-that-sharpens-memories/
Apr 22, 2012...
Imagine never forgetting a single detail of your life — what you got for your 14th birthday, or the phone numbers of every one of your romantic interests. New science from Israel shows that this might be in the realm of possibility. The big question is: Would it be good for us?
The breakthrough Israeli-US research project, for the first time anywhere, has found a compound in the brain to enhance memory. Whether the enzyme responsible could ever be made into a "super pill" (like the one imagined in the science-fiction flick Limitless to boost brainpower) is quite speculative, says Reut Shema from Israel's Weizmann Institute of Science.
https://weizmann-usa.org/news-media/feature-stories/matching-proteins-defeating-disease/
Nov 16, 2016...
Dr. Sarel Fleishman
With dating sites, you can search for a partner who has everything you want, from physical attributes to religious beliefs, education to hobbies, geography to age – and yet finding a mate is challenging for many. Wouldn’t it be nice if the other person could be changed here and there to meet your requirements?
This wish-list technology doesn’t exist yet … for humans. For proteins, it’s another matter, thanks to Dr. Sarel Fleishman at the Weizmann Institute of Science. “I started my career asking, essentially, how do proteins mate?” he says. “They each have knobs and holes that must fit together in a complementary way.”
Aug 02, 2019...
JERUSALEM, Aug. 1 (Xinhua) – Israeli scientists have discovered when and where mistakes occur in the cellular manufacture of proteins, which may help with Alzheimer’s and cancer researches, the Weizmann Institute of Science (WIS) reported Thursday.
The researchers not only succeeded in measuring the rate of such mistakes, but also revealed that the DNA contains a “mistake manual” of sorts that dictates where these mistakes need to be avoided and where they may be tolerated or even welcome.
Apr 23, 2018...
Breast cancer cells in culture form tubelike interconnections. In this image, payloads of molecules (inside blue circles) can be seen moving along these membranous nanotubes and microtubes, illustrating how they might be transmitted to a cell in need of them. Such connections may help cancer cells share their resistance to therapeutic drugs. Ian Smith
When the physician and scientist Emil Lou was an oncology fellow at Memorial Sloan Kettering Cancer Center about a decade ago, he was regularly troubled by the sight of something small but unidentifiable in his cancer-cell cultures. Looking through the microscope, he said, he “kept finding these long, thin translucent lines,” about 50 nanometers wide and 150 to 200 microns long, extending between cells in the culture. He called on the world-class cell biologists in his building to explain these observations, but nobody was sure what they were looking at. Finally, after delving into the literature, Lou realized that the lines matched what Hans-Hermann Gerdes’ group at the University of Heidelberg had described as “nanotubular highways” or “tunneling nanotubes” (TNTs) in a 2004 paper in Science.
May 30, 2015...
Weizmann Institute of Science. (photo credit:MICHAEL JACOBSON/WIKIMEDIA COMMONS)
Researchers from the Weizmann Institute of Science and Tel Aviv University have discovered for the first time how the immune system in bacteria manages to recognize the difference between “foreign” and “self” and fight off invasive viruses called phages.
From single cells to humans, the first challenge of any immune system is to detect this key difference, but it’s far from simple – as viruses, bacteria and all other living things are made of DNA and proteins. Their findings were published online recently in the prestigious journal Nature.
https://weizmann-usa.org/news-media/feature-stories/mother-nature-to-the-rescue/
Apr 30, 2012... Natural molecules that protect the body against disease are finding their way into the treatment of advanced cancer. Prof. Michel Revel of the Department of Molecular Genetics has played a leading role in the discovery and study of two natural molecules now employed as drugs. In the late 1970s, Prof. Revel isolated the gene for interferon-beta, a human protein that fights viral infection in the body and is used as a drug against a variety of ills, including certain types of cancer—particularly glioma and non-small-cell lung carcinoma.
Jan 09, 2019...
Illustration by Jess Rodrigues via Shutterstock.com
Israeli researchers recently made a discovery that could help develop new therapies for anxiety disorders. With up to one in three people around the world at the risk of experiencing severe anxiety, this is big news.
At the heart of the discovery, published in Cell Reports, is a previously unknown biochemical pathway underlying anxiety.
Researchers from the Weizmann Institute of Science biomolecular sciences department studied the role of proteins called importins in the central nervous system (the brain and spinal cord). Importins are found in all cells. Their job is to shuttle molecules into the nucleus.
Feb 25, 2019...
Source: © Shutterstock
‘Since I work on rubisco I’m always giving talks saying that it is the most abundant protein on Earth. Sometimes my audience will ask “Are you really sure?” I can now say “Yes I am”.’ This is how Manajit Hayer-Hartl from the Max Planck Institute of Biochemistry, Germany sums up her thoughts on a new analysis that the global abundance of plants’ carbon dioxide converting enzyme is an order of magnitude higher than thought.
Mar 23, 2020... Dr. Nir London of the Weizmann Institute’s Department of Organic Chemistry explains his lab’s approach to fighting the coronavirus: creating a novel antiviral treatment. After identifying candidates for an antibody, he and his team are designing second-generation compounds that will go to colleagues in Germany and the U.K. for testing against the virus. Dr. London emphasizes the fact that this is open science: research that is freely available to all, for the benefit of everyone.
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