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Comment by Dr. Krishna Kumari Challa on September 28, 2022 at 11:51am

Tiny Robots Have Successfully Cleared Pneumonia From The Lungs of Mice

Scientists have been able to direct a swarm of microscopic swimming robots to clear out pneumonia microbes in the lungs of mice, raising hopes that a similar treatment could be developed to treat deadly bacterial pneumonia in humans.

The microbots are made from algae cells and covered with a layer of antibiotic nanoparticles. The algae provide movement through the lungs, which is key to the treatment being targeted and effective.

In experiments, the infections in the mice treated with the algae bots all cleared up, whereas the mice that weren't treated all died within three days.

The technology is still at a proof-of-concept stage, but the early signs are very promising. Based on this mouse data, researchers see that the microrobots could potentially improve antibiotic penetration to kill bacterial pathogens and save more patients' lives.

The nanoparticles on the algae cells are made of tiny polymer spheres coated with the membranes of neutrophils, a type of white blood cell. These membranes neutralize inflammatory molecules produced by bacteria and the body's own immune system, and both the nanoparticles and the algae degrade naturally.

Harmful inflammation is reduced, improving the fight against infection, and the swimming microbots are able to deliver their treatment right where it's needed – it's the precision that makes this approach work so well.

The researchers also established that the microbot treatment was more effective than an intravenous injection of antibiotics – in fact, the injection dose had to be 3,000 times higher than the one loaded on to the algae cells to achieve the same effect in the mice.

These results show how targeted drug delivery combined with active movement from the microalgae improves therapeutic efficacy.

https://www.nature.com/articles/s41563-022-01360-9

Comment by Dr. Krishna Kumari Challa on September 28, 2022 at 11:27am

Scientists develop novel technique to grow meat in the lab using magnetic field

Scientist  have found a novel way of growing cell-based meat by zapping animal cells with a magnet. This new technique simplifies the production process of cell-based meat by reducing reliance on animal products, and it is also greener, cleaner, safer and more cost-effective.

Cultured meat is an alternative to animal farming with advantages such as reducing carbon footprint and the risk of transmitting diseases in animals. However, the current method of producing cultured meat involves using other animal products, which largely defeats the purpose, or drugs to stimulate the growth of the meat.

To cultivate cell-based meat, animal cells are fed animal serum—usually fetal bovine serum (FBS), which is a mixture harvested from the blood of fetuses excised from pregnant cows slaughtered in the dairy or meat industries—to help them grow and proliferate. This is a critical, yet cruel and expensive, step in the current cell-based meat production process. Ironically, many of these molecules come from the muscles within the slaughtered animal, but scientists did not know how to stimulate their release in production scale bioreactors. Other methods to promote cell growth are using drugs or relying on genetic engineering.

The complex production process for cell-based meat increases cost, limits the manufacturing scale and undermines the commercial viability of cell-based meat.

To help address this challenge, a multidisciplinary research team  came up with an unconventional method of using magnetic pulses to stimulate the growth of cell-based meat.

Growing cell-based meat with the help of a magnet
The new technique uses a delicately tuned pulsed magnetic field developed by the team to culture myogenic stem cells, which are found in skeletal muscle and bone marrow tissue.

In response to a short 10-minute exposure to the magnetic fields, the cells release a myriad of molecules that have regenerative, metabolic, anti-inflammatory and immunity-boosting properties. These substances are part of what is known as the muscle 'secretome' (for secreted factors) and are necessary for the growth, survival and development of cells into tissues. We are very excited about the possibility that magnetically-stimulated secretome release may one day replace the need for FBS in the production of cultured meat.

The growth-inducing secretomes can be harvested in the lab safely and conveniently, and also at low cost. This way, the myogenic stem cells will act as a sustainable and green bioreactor to produce the nutrients-rich secretomes for growing cell-based meat at scale for consumption. The muscle knows how to produce what it needs to grow and develop—it simply needs a little bit of encouragement when it is outside its owner. This is what the magnetic fields can provide.

Applications in regenerative medicine
The harvested secretomes can also be used for regenerative medicine. The  team used the secreted proteins to treat unhealthy cells and found that they help to accelerate the recovery and growth of the unhealthy cells. Therefore, this method can potentially help to cure injured cells and speed up a patient's recovery.

Craig Jun Kit Wong et al, Brief exposure to directionally-specific pulsed electromagnetic fields stimulates extracellular vesicle release and is antagonized by streptomycin: A potential regenerative medicine and food industry paradigm, Biomaterials (2022). DOI: 10.1016/j.biomaterials.2022.121658

Comment by Dr. Krishna Kumari Challa on September 28, 2022 at 9:02am

Researchers reconstruct the genome of the common ancestor of all mammals

Every modern mammal, from a platypus to a blue whale, is descended from a common ancestor that lived about 180 million years ago. We don't know a great deal about this animal, but the organization of its genome has now been computationally reconstructed by an international team of researchers. The work is published Sept. 30 in Proceedings of the National Academy of Sciences.

The researchers drew on high-quality genome sequences from 32 living species representing 23 of the 26 known orders of mammals. They included humans and chimps, wombats and rabbits, manatees, domestic cattle, rhinos, bats and pangolins. The analysis also included the chicken and Chinese alligator genomes as comparison groups. Some of these genomes are being produced as part of the Earth BioGenome Project and other large-scale biodiversity genome sequencing efforts. 

The reconstruction shows that the mammal ancestor had 19 autosomal chromosomes, which control the inheritance of an organism's characteristics outside of those controlled by sex-linked chromosomes (these are paired in most cells, making 38 in total), plus two sex chromosomes.

Scientists  identified 1,215 blocks of genes that consistently occur on the same chromosome in the same order across all 32 genomes. These building blocks of all mammal genomes contain genes that are critical to developing a normal embryo.

The researchers found nine whole chromosomes or chromosome fragments in the mammal ancestor, whose order of genes is the same in modern birds' chromosomes.

This remarkable finding shows the evolutionary stability of the order and orientation of genes on chromosomes over an extended evolutionary timeframe of more than 320 million years.

In contrast, regions between these conserved blocks contained more repetitive sequences and were more prone to breakages, rearrangements and sequence duplications, which are major drivers of genome evolution.

The researchers were able to follow the ancestral chromosomes forward in time from the common ancestor. They found that the rate of chromosome rearrangement differed between mammal lineages.

Joana Damas et al, Evolution of the ancestral mammalian karyotype and syntenic regions, Proceedings of the National Academy of Sciences (2022). DOI: 10.1073/pnas.2209139119

Comment by Dr. Krishna Kumari Challa on September 27, 2022 at 8:20am

New study shows transmission of epigenetic memory across multiple generations

Without altering the genetic code in the DNA, epigenetic modifications can change how genes are expressed, affecting an organism's health and development. The once radical idea that such changes in gene expression can be inherited now has a growing body of evidence behind it, but the mechanisms involved remain poorly understood.

A new study by researchers  shows how a common type of epigenetic modification can be transmitted via sperm not only from parents to offspring, but to the next generation ("grandoffspring") as well. This is called "transgenerational epigenetic inheritance," and it may explain how a person's health and development could be influenced by the experiences of his or her parents and grandparents.

The study, published the week of September 26 in the Proceedings of the National Academy of Sciences (PNAS), focused on a particular modification of a histone protein that changes the way DNA is packaged in the chromosomes. This widely studied epigenetic mark (called H3K27me3) is known to turn off or "repress" the affected genes and is found in all multicellular animals—from humans to the nematode worm C. elegans used in this study.

These results establish a cause-and-effect relationship between sperm-transmitted histone marks and gene expression and development in offspring and grandoffspring.

Sperm-inherited H3K27me3 epialleles are transmitted transgenerationally in cis, Proceedings of the National Academy of Sciences (2022). DOI: 10.1073/pnas.2209471119

Comment by Dr. Krishna Kumari Challa on September 27, 2022 at 8:15am

Disarming the immune system's lethal lung response

Neutrophils, the most abundant type of white blood cell, are the body's first line of defense against infection. Foreign pathogens can stress the body and activate neutrophils. When activated, neutrophils employ various weapons to protect the body. But if overactivated, these weapons can damage the body's own tissues. Lung tissue is saturated with blood vessels, making them very susceptible to neutrophil attacks. If severe enough, acute lung injuries can lead to acute respiratory distress syndrome (ARDS), the leading cause of death due to COVID-19.

Researchers have found a drug candidate that can prevent lethal lung inflammation in mice by inhibiting a protein called PTP1B. Their discovery may help develop better treatments for severe inflammatory conditions like sepsis and COVID-19.

They investigated whether using a PTP1B inhibitor drug candidate could dampen the lethal consequences of overactive neutrophils in mice. They found that pretreating mice with the PTP1B inhibitor reduced lung tissue damage. When untreated, less than half of the mice survived acute lung injuries and ARDS. But when pretreated, they all survived.

The researchers exploited a natural process, called neutrophil aging, that the body uses to control the immune cell's lifespan. As they age, neutrophils become less dangerous. They discovered PTP1B inhibition speeds up neutrophil aging. An aged neutrophil is like a soldier without a weapon. So regardless of how many neutrophils flood an area, they won't be able to do serious damage.

Dongyan Song et al, PTP1B inhibitors protect against acute lung injury and regulate CXCR4 signaling in neutrophils, JCI Insight (2022). DOI: 10.1172/jci.insight.158199

Comment by Dr. Krishna Kumari Challa on September 24, 2022 at 11:07am

Scientists use modified silk proteins to create new nonstick surfaces

Researchers at Tufts University have developed a method to make silk-based materials that refuse to stick to water, or almost anything else containing water for that matter. In fact, the modified silk, which can be molded into forms like plastic, or coated onto surfaces as a film, has non-stick properties that surpass those of nonstick surfaces typically used on cookware, and it could see applications that extend into a wide range of consumer products, as well as medicine.

Comment by Dr. Krishna Kumari Challa on September 24, 2022 at 10:23am

Graphic on NASA's DART mission to crash a small spacecraft into a mini-asteroid to change its trajectory as a test for any potentially dangerous asteroids in the future.

Comment by Dr. Krishna Kumari Challa on September 24, 2022 at 10:22am

NASA gears up to deflect asteroid, in key test of planetary defense

NASA on Monday will attempt a feat humanity has never before accomplished: deliberately smacking a spacecraft into an asteroid to slightly deflect its orbit, in a key test of our ability to stop cosmic objects from devastating life on Earth.

The Double Asteroid Redirection Test (DART) spaceship launched from California last November and is fast approaching its target, which it will strike at roughly 14,000 miles per hour (23,000 kph).

To be sure, neither the asteroid moonlet Dimorphos, nor the big brother it orbits, called Didymos, pose any threat as the pair loop the Sun, passing some seven million miles from Earth at nearest approach.

But the experiment is one NASA has deemed important to carry out before an actual need is discovered.

If all goes to plan, impact between the car-sized spacecraft, and the 530-foot (160 meters, or two Statues of Liberty) asteroid should take place on September 26 

By striking Dimorphos head on, NASA hopes to push it into a smaller orbit, shaving ten minutes off the time it takes to encircle Didymos, which is currently 11 hours and 55 minutes—a change that will be detected by ground telescopes in the days that follow.

The proof-of-concept experiment will make a reality what has before only been attempted in science fiction

Comment by Dr. Krishna Kumari Challa on September 23, 2022 at 11:48am

Discovery explains cancer chemotherapy resistance, offers solution

Researchers have uncovered a novel pathway that explains how cancer cells become resistant to chemotherapies, which in turn offers a potential solution for preventing chemo-resistance.

Experimental DNA fibers with fluorescence were used to reveal the speed of DNA replication forks.

The research describes for the first time how a type of enzyme -- previously known for its roles in DNA repair -- prevents DNA damage in cancer cells, making them tolerant to chemotherapy drugs. It provides scientists tools to manipulate and then break chemo-resistance in cancer cells. 

Many anti-cancer drugs work by creating blocks on the DNA of cancer cells as they replicate. During replication, DNA strands entwined in a double helix separate into two individual strands so each strand can be copied, eventually leading to two new double helixes. The junction where this separation and copying occurs is called a replication fork, which unzips down the double helix.

If these replication forks were cars on a road, chemotherapy drugs can be imagined as obstacles that interfere with the flow of the cars, thus stopping replication and breaking DNA. But cancer cells have a way of slowing down these forks, which allows them to avoid such collisions and protect their DNA, leading to drug tolerance.

This study reports, for the first time, how a kinase (enzyme) called DNA-PKcs acts as a sensor when a fork is stressed due to blocks, and promotes slowing of the fork and chemo-resistance. DNA-PKcs has been known for its role in DNA repair related to immune system antibody generation and resistance to radiation. But this is the first time the kinase has been associated with slowing a replication fork, a process called fork reversal.

The results open the door to new cancer treatments, as DNA-PKcs inhibitors already exist and are being used for clinical trials in tandem with radiation therapies.

Diego Dibitetto, Shannon Marshall, Andrea Sanchi, Martin Liptay, Jumana Badar, Massimo Lopes, Sven Rottenberg, Marcus B. Smolka. DNA-PKcs promotes fork reversal and chemoresistance. Molecular Cell, 2022; DOI: 10.1016/j.molcel.2022.08.028

Comment by Dr. Krishna Kumari Challa on September 23, 2022 at 6:48am

More than one-tenth of the world's terrestrial genetic diversity may already be lost, study says

Climate change and habitat destruction may have already caused the loss of more than one-tenth of the world's terrestrial genetic diversity, according to new research published in Science. This means that it may already be too late to meet the United Nations' proposed target, announced last year, of protecting 90 percent of genetic diversity for every species by 2030, and that we have to act fast to prevent further losses.

Several hundred species of animals and plants have gone extinct in the industrialized age and human activity has impacted or shrunk half of Earth's ecosystems, affecting millions of species. The partial loss of geographic range diminishes population size and can geographically prevent populations of the same species from interacting with each other. This has serious implications for an animal or plant's genetic richness and their ability to meet the coming challenges of climate change.

When you take away or fundamentally alter swaths of a species' habitat, you restrict the genetic richness available to help those plants and animals adapt to shifting conditions. Until recently, this important component has been overlooked when setting goals for preserving biodiversity, but without a diverse pool of natural genetic mutations on which to draw, species will be limited in their ability to survive alterations to their geographic range.

In popular culture, mutations convey super powers that defy the laws of physics. But in reality, mutations represent small, random natural variations in the genetic code that could positively or negatively affect an individual organism's ability to survive and reproduce, passing down the positive traits down to future generations.

As a result, the greater the pool of mutations upon which a species is able to draw, the greater the chances of stumbling upon that lucky blend that will help a species thrive despite the pressures created by habitat loss, as well as shifting temperature and precipitation patterns.

Moises Exposito-Alonso, Genetic diversity loss in the Anthropocene, Science (2022). DOI: 10.1126/science.abn5642. www.science.org/doi/10.1126/science.abn5642

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