Posts belonging to Category RNA



DNA Origami, The New Revolution To Come For Nanotechnology

For the past few decades, some scientists have known the shape of things to come in nanotechnology is tied to the molecule of life, DNA. This burgeoning field is called “DNA origami.” The moniker is borrowed from the art of conjuring up birds, flowers and other shapes by imaginatively folding a single sheet of paper. Similarly, DNA origami scientists are dreaming up a variety of shapes — at a scale one thousand times smaller than a human hair — that they hope will one day revolutionize computing, electronics and medicine. Now, a team of Arizona State University and Harvard scientists has invented a major new advance in DNA nanotechnology. Dubbed “single-stranded origami” (ssOrigami), their new strategy uses one long noodle-like strand of DNA, or its chemical cousin RNA, that can self-fold — without even a single knot — into the largest, most complex structures to date. And the strands forming these structures can be made inside living cells or using enzymes in a test tube, allowing scientists the potential to plug-and-play with new designs and functions for nanomedicine: picture tiny nanobots playing doctor and delivering drugs within cells at the site of injury.

A DNA origami with an emoji-like smiley face

I think this is an exciting breakthrough, and a great opportunity for synthetic biology as well,” said Hao Yan, a co-inventor of the technology, director of the ASU Biodesign Institute’s Center for Molecular Design and Biomimetics, and the Milton Glick Professor in the School of Molecular Sciences.

We are always inspired by nature’s designs to make information-carrying molecules that can self-fold into the nanoscale shapes we want to make,” he said.

As proof of concept, they’ve pushed the envelope to make 18 shapes, including emoji-like smiley faces, hearts and triangles, that significantly expand the design studio space and material scalability for so-called, “bottom-upnanotechnology.

Source: https://asunow.asu.edu/

Swiss Army Knife NanoVaccine To Fight Tumors

Scientists are using their increasing knowledge of the complex interaction between cancer and the immune system to engineer increasingly potent anti-cancer vaccines.
Now researchers at the National Institute ofBiomedical Imaging and Bioengineering (NIBIB) have developed a synergistic nanovaccine packing DNA and RNA sequences that modulate the immune response, along with anti-tumor antigens, into one smallnanoparticle. The nanovaccine produced an immune response that specifically killed tumor tissue, while simultaneously inhibiting tumor-induced immune suppression. Together this blocked lung tumor growth in a mouse model of metastatic colon cancer.

Large particles (left) containing the DNA and RNA components are coated with electronically charged molecules that shrink the particle. The tumor-specific neoantigen is then complexed with the surface to complete construction of the nanovaccine.
Upper left: electron micrograph of large particle

 

The molecular dance between cancer and the immune system is a complex one and scientists continue to identify the specific molecular pathways that rev up or tamp down the immune system. Biomedical engineers are using this knowledge to create nanoparticles that can carry different molecular agents that target these pathways. The goal is to simultaneously stimulate the immune system to specifically attack the tumor while also inhibiting the suppression of the immune system, which often occurs in cancer patients. The aim is to press on the gas pedal of the immune system while also releasing the emergency brake.

A key hurdle is to design a system to reproducibly and efficiently create a nanoparticle loaded with multiple agents that synergize to mount an enhanced immune attack on the tumor. Engineers at the NIBIB report the development and testing of such a nanovaccine in the journal Nature Communications.

Source: https://www.nibib.nih.gov/

How To Correct Genes That Cause High Cholesterol

U.S. researchers have used nanotechnology plus the powerful CRISPR-Cas9 gene-editing tool to turn off a key cholesterol-related gene in mouse liver cells, an advance that could lead to new ways to correct genes that cause high cholesterol and other liver diseasesNanotechnology is the design and manipulation of materials thousands of times smaller than the width of a human hair.

We’ve shown you can make a nanoparticle that can be used to permanently and specifically edit the DNA in the liver of an adult animal,” said study author Daniel Anderson, an associate professor in chemical engineering at the Massachusetts Institute of Technology.

The study, published  in Nature Biotechnology, holds promise for permanently editing genes such as PCSK9, a cholesterol-regulating gene that is already the target of two drugs made by the biotechnology companies Regeneron Pharmaceuticals and Amgen.

In the study, the scientists were trying to develop a safe and efficient way to deliver the components needed for CRISPR-Cas9, a type of molecular scissors that can selectively trim away defective genes and replace them with new stretches of DNA.

The system consists of a DNA-cutting enzyme called Cas9 and a stretch of RNA that guides the cutting enzyme to the correct spot in the genome. Most teams currently use viruses to deliver CRISPR into cells, an approach that is limited because the immune system can develop antibodies to viruses.

To overcome this, the team chemically modified the CRISPR components to protect them from enzymes in the body that would normally break them down. They then inserted this material into nano-scale fat particles and injected them into mice, where they made their way to liver cells.

In tests targeting the PCSK9 gene, the system proved highly effective, . The PCSK9 protein made by this gene was undetectable in the treated mice, eliminating the gene in more than 80 percent of liver cells, which also experienced a 35 percent drop in total cholesterol, the researchers reported.

High levels of cholesterol can clog arteries, causing reduced blood flow that can lead to a heart attack or stroke.

Source: http://news.mit.edu/

Editing Genes In Human Embryos

Two new CRISPR tools overcome the scariest parts of gene editing.The ability to edit RNA and individual DNA base pairs will make gene editing much more precise. Several years ago, scientists discovered a technique known as CRISPR/Cas9, which allowed them to edit DNA more efficiently than ever before.
Since then, CRISPR science has exploded; it’s become one of the most exciting and fast-moving areas of research, transforming everything from medicine to agriculture and energy. In 2017 alone, more than 14,000 CRISPR studies were published.

But here’s the thing: CRISPR, while a major leap forward in gene editing, can still be a blunt instrument. There have been problems with CRISPR modifying unintended gene targets and making worrisome, and permanent, edits to an organism’s genome. These changes could be passed down through generations, which has raised the stakes of CRISPR experiments — and the twin specters of “designer babies” and genetic performance enhancers — particularly when it comes to editing genes in human embryos.
So while CRISPR science is advancing quickly, scientists are still very much in the throes of tweaking and refining their toolkit. And on Wednesday, researchers at the Broad Institute of MIT and Harvard launched a coordinated blitz with two big reports that move CRISPR in that safer and more precise direction.
In a paper published in Science, researchers described an entirely new CRISPR-based gene editing tool that targets RNA, DNA’s sister, allowing for transient changes to genetic material. In Nature, scientists described how a more refined type of CRISPR gene editing can alter a single bit of DNA without cutting it — increasing the tool’s precision and efficiency.

The first paper, out Wednesday in Science, describes a new gene editing system. This one, from researchers at MIT and Harvard, focuses on tweaking human RNA instead of DNA.

Our cells contain chromosomes made up of chemical strands called DNA, which carry genetic information. Those genes have recipes for proteins that lead to a bunch of different traits. But to carry out the instructions in any one recipe, DNA needs another type of genetic material called RNA to get involved.

RNA is ephemeral: It acts like a middleman, or a messenger. For a gene to become a protein, that gene has to be transcribed into RNA in the cell, and the RNA is then read to make the protein. If the DNA is permanent — the family recipe book passed down through generations — the RNA is like your aunt’s scribbled-out recipe on a Post-It note, turning up only when it’s needed and disappearing again.

With the CRISPR/Cas9 system, researchers are focused on editing DNA. (For more on how that system works, read this Vox explainer.) But the new Science paper describes a novel gene editing tool called REPAIR that’s focused on using a different enzyme, Cas13, to edit that transient genetic material, the RNA, in cells. REPAIR can target specific RNA letters, or nucleosides, that are involved in single-base changes that regularly cause disease in humans.

This is hugely appealing for one big reason: With CRISPR/Cas9, the changes to the genome, or the cell’s recipe book, are permanent. You can’t undo them. With REPAIR, since researchers can target single bits of ephemeral RNA, the changes they make are transient, even reversible. So this system could fix genetic mutations without actually touching the genome (like throwing away your aunt’s Post-It note recipe without adding it to the family recipe book).

Source: https://www.vox.com/

Gene Researchers Have Created Green Mice

These are no Frankenstein mice. Their green feet come courtesy of a fluorescent green jelly fish gene added to their own genome. This allows a team of British scientists to test out gene editing using CRISPR-Cas9 technology.

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“We take what were or would have been green embryos and we make them into non-green embryos, so it’s a really great way of demonstrating the method“, said Dr. Anthony Perry, reproductive biologist at the University of Bath.

The technique uses the ribonucleic acid molecule CRISPR together with the Cas9 protein enzyme. CRISPR guides the Cas9 protein to a defective part of a genome where it acts like molecular scissors to cut out a specific part of the DNA. This could revolutionise how we treat diseases with a genetic component, like sickle cell anaemia. The technique is being pioneered in the U.S.
We now have a technology that allows correction of a sequence that would lead to normally functioning cells. And I think you know the opportunities with this are really exciting and really profound. There are many diseases that are have known genetic causes that we now have in principle a way to cure,“explains Jennifer Doudna, Professor of cell biology at the University of Berkeley.
Last year two teams of U.S. based scientists used CRISPR-Cas9 technology in mice to correct the genetic mutation that causes sickle cell disease. Although researchers aren’t yet close to using CRISPR-Cas9 to edit human embryos for implantation into the womb – some are already warning against it.

Dr David King, Director of  Human Genetics Alert, comments: “It will immediately create this new form of what we call consumer eugenics, that’s to say eugenics driven by the free market and consumer preferences in which people choose the cosmetic characteristics and the abilities of their children and try to basically enhance their children to perform better than other people’s children.” Other potential applications of the technology could be to make food crops and livestock animal species disease-resistant. The British team say CRISPR-Cas9 presents a golden opportunity to prevent genetic disease.

Source: http://www.reuters.com/
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How To Fix Duchenne Muscular Dystrophy

Scientists at the University of California, Berkeley, have engineered a new way to deliver CRISPR-Cas9 gene-editing technology inside cells and have demonstrated in mice that the technology can repair the mutation that causes Duchenne muscular dystrophy, a severe muscle-wasting disease. A new study shows that a single injection of CRISPR-Gold, as the new delivery system is called, into mice with Duchenne muscular dystrophy led to an 18-times-higher correction rate and a two-fold increase in a strength and agility test compared to control groups.

Since 2012, when study co-author Jennifer Doudna, a professor of molecular and cell biology and of chemistry at UC Berkeley, and colleague Emmanuelle Charpentier, of the Max Planck Institute for Infection Biology, repurposed the Cas9 protein to create a cheap, precise and easy-to-use gene editor, researchers have hoped that therapies based on CRISPR-Cas9 would one day revolutionize the treatment of genetic diseases. Yet developing treatments for genetic diseases remains a big challenge in medicine. This is because most genetic diseases can be cured only if the disease-causing gene mutation is corrected back to the normal sequence, and this is impossible to do with conventional therapeutics.

CRISPR/Cas9, however, can correct gene mutations by cutting the mutated DNA and triggering homology-directed DNA repair. However, strategies for safely delivering the necessary components (Cas9, guide RNA that directs Cas9 to a specific gene, and donor DNA) into cells need to be developed before the potential of CRISPR-Cas9-based therapeutics can be realized. A common technique to deliver CRISPR-Cas9 into cells employs viruses, but that technique has a number of complications. CRISPR-Gold does not need viruses.

In the new study, research lead by the laboratories of Berkeley bioengineering professors Niren Murthy and Irina Conboy demonstrated that their novel approach, called CRISPR-Gold because gold nanoparticles are a key component, can deliver Cas9 – the protein that binds and cuts DNA – along with guide RNA and donor DNA into the cells of a living organism to fix a gene mutation.

CRISPR-Gold is the first example of a delivery vehicle that can deliver all of the CRISPR components needed to correct gene mutations, without the use of viruses,” Murthy said.

The study was published in the journal Nature Biomedical Engineering.

Source: http://news.berkeley.edu/

Nanogels For Heart Attack Patients

Heart disease and heart-related illnesses are a leading cause of death around the world, but treatment options are limited. Now, one group reports in ACS Nano that encapsulating stem cells in a nanogel could help repair damage to the heart.

Myocardial infarction, also known as a heart attack, causes damage to the muscular walls of the heart. Scientists have tried different methods to repair this damage. For example, one method involves directly implanting stem cells in the heart wall, but the cells often don’t take hold, and sometimes they trigger an immune reaction. Another treatment option being explored is injectable hydrogels, substances that are composed of water and a polymer. Naturally occurring polymers such as keratin and collagen have been used but they are expensive, and their composition can vary between batches. So Ke Cheng, Hu Zhang, Jinying Zhang and colleagues wanted to see whether placing stem cells in inexpensive hydrogels with designed tiny pores that are made in the laboratory would work.

The team encapsulated stem cells in nanogels, which are initially liquid but then turn into a soft gel when at body temperature. The nanogel didn’t adversely affect stem cell growth or function, and the encased stem cells didn’t trigger a rejection response. When these enveloped cells were injected into mouse and pig hearts, the researchers observed increased cell retention and regeneration compared to directly injecting just the stem cells. In addition, the heart walls were strengthened. Finally, the group successfully tested the encapsulated stem cells in mouse and pig models of myocardial infarction.

Source: https://www.acs.org/
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https://global.ncsu.edu/

New Treatment To Kill Cancer

Raise your hand if you haven’t been touched by cancer,” says Mylisa Parette to a roomful of strangers. Parette, the research manager for Keystone Nano (KN), has occasional opportunities to present her company’s technologies to business groups and wants to emphasize the scope of the problem that still confronts society. “It’s easier to see the effects of cancer when nobody raises their hand,” she says. Despite 40 years of the War on Cancer, one in two men and one in three women will be diagnosed with the disease at some point in their lifetime. Parette and her Keystone Nano colleagues are working on a new approach to cancer treatment. The company was formed from the collaboration of two Penn State faculty members who realized that the nanoparticle research that the one was undertaking could be used to solve the drug delivery problems that the other was facing.

Mark Kester, a pharmacologist at Penn State College of Medicine in Hershey, was working with a new drug that showed real promise as a cancer therapy but that could be dangerous if injected directly into the bloodstream. Jim Adair, a materials scientist in University Park, was creating nontoxic nanoparticles that could enclose drugs that might normally be toxic or hydrophobic and were small enough to be taken up by cells.

The two combined their efforts and, licensing the resulting technology from Penn State, they joined with entrepreneur Jeff Davidson, founder of the Biotechnology Institute and the Pennsylvania Biotechnology Association, to form Keystone Nano. The new company’s first hire was Parette, whose job is to translate the lab-scale technology into something that can be ramped up to an industrial scale, and to prepare that technology for FDA approval leading to clinical trials.

Davidson, Parette, and KN’s research team work out of the Zetachron building, a long, one-story science incubator a mile from Penn State’s University Park campus. Operated by the Centre County Industrial Development Corporation, the building was originally the home of the successful Penn State spin-out company that gave it its name. A second Keystone Nano lab was recently opened in the Hershey Center for Applied Research, a biotech incubator adjacent to Penn State College of Medicine.

Our excitement is that we think our technology has shown efficacy in a whole range of animal models,” Davidson, Keystone CEO, remarks during a recent meeting in the shared conference room at Zetachron. “We understand the method of action, the active ingredient. We think it has every chance of being useful in treating disease. Our question is, how do we push this forward from where we are today to determining, one way or another, that it really does work?

Keystone Nano is pioneering two approaches to cancer therapy, both of which rely on advances in nanotechnology to infiltrate tumors and deliver a therapeutic agent. The approach nearest to clinical trials is a ceramide nanoliposome, or what Davidson calls a “nano fat ball around an active ingredient.” Kester, in whose lab the approach was developed, thinks of it as a basketball with a thick bilayer coating that contains 30 percent active ceramide and a hollow interior that can hold another cancer drug.

Source: http://news.psu.edu/

Brain Cells Found To Control Aging

Scientists at Albert Einstein College of Medicine have found that stem cells in the brain’s hypothalamus govern how fast aging occurs in the body. The finding, made in mice, could lead to new strategies for warding off age-related diseases and extending lifespan. The hypothalamus was known to regulate important processes including growth, development, reproduction and metabolism. In a 2013 Nature paper, Einstein researchers made the surprising finding that the hypothalamus also regulates aging throughout the body. Now, the scientists have pinpointed the cells in the hypothalamus that control aging: a tiny population of adult neural stem cells, which were known to be responsible for forming new brain neurons.

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Our research shows that the number of hypothalamic neural stem cells naturally declines over the life of the animal, and this decline accelerates aging,” says senior author Dongsheng Cai, M.D., Ph.D., professor of molecular pharmacology at Einstein. “But we also found that the effects of this loss are not irreversible. By replenishing these stem cells or the molecules they produce, it’s possible to slow and even reverse various aspects of aging throughout the body.”

The findings have been published online in Nature.

Source: http://www.einstein.yu.edu/
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http://www.reuters.com/

How To Generate Any Cell Within The Patient’s Own Body

Researchers at The Ohio State University Wexner Medical Center and Ohio State’s College of Engineering have developed a new technology, Tissue Nanotransfection (TNT), that can generate any cell type of interest for treatment within the patient’s own body. This technology may be used to repair injured tissue or restore function of aging tissue, including organs, blood vessels and nerve cells.

By using our novel nanochip technology (nanocomputer), injured or compromised organs can be replaced. We have shown that skin is a fertile land where we can grow the elements of any organ that is declining,” said Dr. Chandan Sen, director of Ohio State’s Center for Regenerative Medicine & Cell Based Therapies, who co-led the study with L. James Lee, professor of chemical and biomolecular engineering with Ohio State’s College of Engineering in collaboration with Ohio State’s Nanoscale Science and Engineering Center.

Researchers studied mice and pigs in these experiments. In the study, researchers were able to reprogram skin cells to become vascular cells in badly injured legs that lacked blood flow. Within one week, active blood vessels appeared in the injured leg, and by the second week, the leg was saved. In lab tests, this technology was also shown to reprogram skin cells in the live body into nerve cells that were injected into brain-injured mice to help them recover from stroke.

This is difficult to imagine, but it is achievable, successfully working about 98 percent of the time. With this technology, we can convert skin cells into elements of any organ with just one touch. This process only takes less than a second and is non-invasive, and then you’re off. The chip does not stay with you, and the reprogramming of the cell starts. Our technology keeps the cells in the body under immune surveillance, so immune suppression is not necessary,” said Sen, who also is executive director of Ohio State’s Comprehensive Wound Center.

Results of the regenerative medicine study have been published in the journal  Nature Nanotechnology.

Source: https://news.osu.edu/

Faulty DNA Linked To Fatal Heart Condition Removed From Embryo

Scientists have modified human embryos to remove genetic mutations that cause heart failure in otherwise healthy young people in a landmark demonstration of the controversial procedure. It is the first time that human embryos have had their genomes edited outside China, where researchers have performed a handful of small studies to see whether the approach could prevent inherited diseases from being passed on from one generation to the next.

While none of the research so far has created babies from modified embryos, a move that would be illegal in many countries, the work represents a milestone in scientists’ efforts to master the technique and brings the prospect of human clinical trials one step closer. The work focused on an inherited form of heart disease, but scientists believe the same approach could work for other conditions caused by single gene mutations, such as cystic fibrosis and certain kinds of breast cancer.

This embryo gene correction method, if proven safe, can potentially be used to prevent transmission of genetic disease to future generations,” said Paula Amato, a fertility specialist involved in the US-Korean study at Oregon Health and Science University.

The scientists used a powerful gene editing tool called Crispr-Cas9 to fix mutations in embryos made with the sperm of a man who inherited a heart condition known as hypertrophic cardiomyopathy, or HCM. The disease, which leads to a thickening of the heart’s muscular wall, affects one in 500 people and is a common cause of sudden cardiac arrest in young people. Humans have two copies of every gene, but some diseases are caused by a mutation in only one of the copies. For the study, the scientists recruited a man who carried a single mutant copy of a gene called MYBPC3 which causes HCM.

Source: https://www.theguardian.com/

Cancer: A Giant Step For Immunotherapy

A Food and Drug Administration (FDA) panel opened a new era in medicine, unanimously recommending that the agency approve the first-ever treatment that genetically alters a patient’s own cells to fight cancer, transforming them into what scientists call “a living drug” that powerfully bolsters the immune system to shut down the disease.

If the F.D.A. accepts the recommendation, which is likely, the treatment will be the first gene therapy ever to reach the market. Others are expected: Researchers and drug companies have been engaged in intense competition for decades to reach this milestone. Novartis is now poised to be the first. Its treatment is for a type of leukemia, and it is working on similar types of treatments in hundreds of patients for another form of the disease, as well as multiple myeloma and an aggressive brain tumor.

To use the technique, a separate treatment must be created for each patient — their cells removed at an approved medical center, frozen, shipped to a Novartis plant for thawing and processing, frozen again and shipped back to the treatment center.

A single dose of the resulting product has brought long remissions, and possibly cures, to scores of patients in studies who were facing death because every other treatment had failed. The panel recommended approving the treatment for B-cell acute lymphoblastic leukemia that has resisted treatment, or relapsed, in children and young adults aged 3 to 25.

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We believe that when this treatment is approved it will save thousands of children’s lives around the world,” Emily’s father, Tom Whitehead, told the panel. “I hope that someday all of you on the advisory committee can tell your families for generations that you were part of the process that ended the use of toxic treatments like chemotherapy and radiation as standard treatment, and turned blood cancers into a treatable disease that even after relapse most people survive.”

The main evidence that Novartis presented to the F.D.A. came from a study of 63 patients who received the treatment from April 2015 to August 2016. Fifty-two of them, or 82.5 percent, went into remission — a high rate for such a severe disease. Eleven others died.

It’s a new world, an exciting therapy,” said Dr. Gwen Nichols, the chief medical officer of the Leukemia and Lymphoma Society, which paid for some of the research that led to the treatment. The next step, she said, will be to determine “what we can combine it with and is there a way to use it in the future to treat patients with less disease, so that the immune system is in better shape and really able to fight.” She added, “This is the beginning of something big.”

Source: http://www.chop.edu/
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