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Comment by Dr. Krishna Kumari Challa on December 11, 2022 at 6:46am

The researchers knew that worm hatchlings contain aPSCs, so reasoned they must be made during embryogenesis. Ricci used transgenesis to create a line that caused embryo cells to glow in fluorescent green due to the introduction of the protein Kaede into the cell. Kaede is photo-convertible, which means shining a laser beam with a very specific wavelength on the green will convert it to a red color. You can then zap the cells with a laser to turn individual green cells of the embryo into a red color.

Using transgenic animals with photo-conversion is a very new twist the researchers devised in the lab to figure out the fates of embryonic cells.

 They followed the embryo's development as it split from single cell to multiple cells. Early division of these cells is marked by stereotyped cleavage, which means embryo to embryo cells divide in the exact same pattern such that cells can be named and studied consistently. This raised the possibility that perhaps every single cell has a unique purpose. For instance, at the eight-cell stage it's possible the top, left corner cell makes a certain tissue, while the bottom, right cell makes another tissue.

To determine the function of each cell, they systematically performed photo-conversion for each of the cells of the early embryo, creating a full fate map at the eight-cell stage. They then tracked the cells as the worm grew into an adult that still carried the red labeling. The repetitious process of following each individual cell again and again across many embryos made it possible for them to trace where each cell was working.

At the sixteen-cell stage embryo they found a very specific pair of cells that gave rise to cells that looked to be the neoblasts.

To be certain, the researchers put this particular set of cells, called 3a/3b in H. miamia, on trial. In order to be the neoblasts the cells must satisfy all of the known properties of stem cells. Are the progeny of those cells making new tissue during regeneration? The researchers found that yes, the progeny of only those cells made new tissue during regeneration.

Part 2

Comment by Dr. Krishna Kumari Challa on December 11, 2022 at 6:43am

Researchers discover embryonic origins of adult pluripotent stem cells

Stem cells are a biological wonder. They can repair, restore, replace, and regenerate cells. In most animals and humans these cells are limited to regenerating only the cell type they are assigned to. So, hair stem cells will only make hair. Intestine stem cells will only make intestines. But, many distantly-related invertebrates have stem cell populations that are pluripotent in adult animals, which means they can regenerate virtually any missing cell type, a process called whole-body regeneration.

Even though these adult pluripotent stem cells (aPSCs) are found in many different types of animals (such as sponges, hydras, planarian flatworms, acoel worms, and some sea squirts) the mechanism of how they are made is not known in any species.

In a new study in Cell researchers  have identified the cellular mechanism and molecular trajectory for the formation of aPSCs in the acoel worm, Hofstenia miamia.

H. miamia, also known as the three-banded panther worm, is a species that can fully regenerate using aPSCs called "neoblasts." Chop H. miamia into pieces and each piece will grow a new body including everything from a mouth to the brain.

 Researchers developed a protocol for transgenesis in H. miamia. Transgenesis is a process that introduces something into the genome of an organism that is not normally part of that genome. This method allowed the researchers to pursue this question of how these stem cells are made.

One common characteristic among animals that can regenerate is the presence of pluripotent stem cells in the adult body. These cells are responsible for re-making missing body parts when the animal is injured. By understanding how animals like H. miamia make these stem cells, they felt they could better understand what gives certain animals regenerative abilities.

There are some unifying features of these stem cell populations in adult animals such as the expression of a gene called Piwi.

Part 1

Comment by Dr. Krishna Kumari Challa on December 11, 2022 at 6:33am

Do You Flush With The Lid Up? You Won't After Watching This

New research shows the impact of flushing the toilet in a whole new light. Using bright green lasers and camera equipment, a team of  engineers ran an experiment to reveal how tiny water droplets, invisible to the naked eye, are rapidly ejected into the air when a lid-less, public restroom toilet is flushed. These aerosolized particles are known to transport pathogens and could pose an exposure risk to public bathroom patrons. This visualization method, however, provides experts in plumbing and public health with a consistent way to test improved plumbing design and disinfection and ventilation strategies, in order to reduce exposure risk to pathogens in public restrooms.

Comment by Dr. Krishna Kumari Challa on December 10, 2022 at 10:17am

A surprising discovery: The female locust has superhero-like abilities

A new Tel Aviv University study has discovered that the female locust has superpowers. The findings of the study reveal that the female locust's central nervous system has elastic properties, allowing her to stretch up to two or three times her original length when laying her eggs in the ground, without causing any irreparable damage.

We are not aware of a similar ability in almost any living creature. Nerves in the human nervous system, for example, can stretch only up to 30% without tearing or being permanently damaged. In the future, these findings may contribute to new developments in the field of regenerative medicine, as a basis for nerve restoration and the development of synthetic tissues.

When the female locust is ready to lay her eggs, she digs a hole in the ground that will offer them protection and optimal conditions for hatching. For this purpose, she is equipped with a unique digging apparatus, consisting of two pairs of digging valves which are located at the tip of the abdomen, on either side of the ovipositor (a tube-like organ used for laying eggs).

"As she digs, the female extends her body, until sensors located along its length signal that she has reached a suitable point for depositing her eggs. Thus, an adult female, whose body length is about four to five centimeters, may, for the purpose of laying her eggs, stretch her body to a length of 10–15 centimeters, then quickly return to her normal length, and then extend again for the next egg-laying.

The superpower of the locust is almost something out of science fiction. There are only two other known examples in nature of a similar phenomenon: the tongue of the sperm whale, and a certain type of sea snail whose nervous systems are able to extend significantly due to an accordion-like mechanism they have. Scientists sought to identify the biomechanical mechanism that gives the female locust its wonderful ability.

In the study, the researchers removed the central nervous systems from female locusts and placed them in a liquid simulating their natural environment, under physiological conditions similar to those inside the body. Using highly sensitive measuring instruments, they measured the forces needed to extend the nervous system.

Contrary to previous hypotheses and examples we are familiar with, they did not find any accordion-like mechanism. They discovered that the nervous system of the female locust has elastic properties, which enable it to elongate and then return by itself to its original state, ready for reuse, without any damage caused to the tissue. This finding is almost incomprehensible from a biomechanical and morphological point of view.

The researchers hope that in the future their findings will help to develop synthetic tissues with a high level of flexibility, and to restore nerves in regenerative medicine therapies.

https://www.sciencedirect.com/science/article/pii/S258900422201567X

Comment by Dr. Krishna Kumari Challa on December 10, 2022 at 10:10am

Scientists shed new light on genetic changes that turn 'on' cancer genes

Cancer, caused by abnormal overgrowth of cells, is the second-leading cause of death in the world. Researchers  have zeroed in on specific mechanisms that activate oncogenes, which are altered genes that can cause normal cells to become cancer cells.

Cancer can be caused by genetic mutations, yet the impact of specific types such as structural variants that break and rejoin DNA, can vary widely. The findings, published in Nature on December 7, 2022, show that the activity of those mutations depends on the distance between a particular gene and the sequences that regulate the gene, as well as on the level of activity of the regulatory sequences involved.

This work advances the ability to predict and interpret which genetic mutations found in cancer genomes are causing the disease.

Most genetic mutations have no impact on a cancer and the molecular incidents that lead to oncogene activation are relatively rare.

Using CRISPR-Cas9 gene editing, the researchers introduced genetic mutations by cutting DNA in certain locations of the genome. They found that some of the variants they created had major impacts on the expression of nearby genes, and could ultimately cause cancer, but that most had essentially no impact. Some genes appeared to go haywire when they were brought into environments with novel regulatory sequences, and others were not affected at all. The type of sequence that was introduced appeared to have a huge impact on whether or not the cell became cancerous.

Their next move is to test whether there are other factors in the genome that contribute to the activation of oncogene.

Zhichao Xu, Dong-Sung Lee, Sahaana Chandran, Victoria T. Le, Rosalind Bump, Jean Yasis, Sofia Dallarda, Samantha Marcotte, Benjamin Clock, Nicholas Haghani, Chae Yun Cho, Kadir C. Akdemir, Selene Tyndale, P. Andrew Futreal, Graham McVicker, Geoffrey M. Wahl, Jesse R. Dixon. Structural variants drive context-dependent oncogene activation in cancer. Nature, 2022; DOI: 10.1038/s41586-022-05504-4

Comment by Dr. Krishna Kumari Challa on December 10, 2022 at 9:39am

Aging is driven by unbalanced genes, finds AI analysis of multiple species

Researchers have discovered a previously unknown mechanism that drives aging.

In a new study, researchers used artificial intelligence to analyze data from a wide variety of tissues, collected from humans, mice, rats and killifish. They discovered that the length of genes can explain most molecular-level changes that occur during aging.

All cells must balance the activity of long and short genes. The researchers found that longer genes are linked to longer lifespans, and shorter genes are linked to shorter lifespans. They also found that aging genes change their activity according to length. More specifically, aging is accompanied by a shift in activity toward short genes. This causes the gene activity in cells to become unbalanced.

Surprisingly, this finding was near universal. The researchers uncovered this pattern across several animals, including humans, and across many tissues (blood, muscle, bone and organs, including liver, heart, intestines, brain and lungs) analyzed in the study.

The new finding potentially could lead to interventions designed to slow the pace of—or even reverse—aging.

Aging is associated with a systemic length-associated transcriptome imbalance, Nature Aging (2022).

https://phys.org/news/2022-12-aging-driven-unbalanced-genes-ai.html...

Comment by Dr. Krishna Kumari Challa on December 10, 2022 at 9:12am

Scientists identify gene that controls scarring in damaged hearts

Scientists  have identified a gene that controls the behaviour of a specific type of cardiac macrophage responsible for excessive scarring during the early phases of common heart diseases or cardiomyopathies. When the gene, called WWP2, is blocked, heart function is improved and scar tissue formation is slowed, delaying the progression to heart failure.

Scarring or fibrosis of the heart, as in non-ischemic cardiomyopathies, is a progressive condition and global health concern. In its earliest stages, it is characterized by an inflammatory phase, so intervening at that point could significantly delay disease progression.

Researchers had been studying the function of WWP2 in fibrotic diseases for several years, first discovering that it is a significant driver of scaring when it is expressed in fibroblasts—the cells that make scar tissue. In their latest findings, published in Nature Communications, his team turned their attention to the early stage of the disease.

Using single cell RNA sequencing, the team found when fibrosis is triggered, a wide range of different macrophages—immune cells that clear foreign material in the body—are activated in a preclinical model of heart disease. While macrophages are mostly known for their role in removing cancer cells, microbes and cellular debris, they also help with the regeneration of healthy muscle cells.

However, a subset of these cardiac macrophages are controlled by WWP2. These WWP2-expressing macrophages actively promote scarring by triggering local cardiac cells (fibroblasts) to produce collagen in an uncontrolled manner, fuelling scar tissue formation.

In this latest study, researchers focused on the 'cross-talk' that happens between macrophages and fibroblasts in the early stages of fibrogenesis. They  found that when WWP2 is expressed in macrophages, these cells 'irritate' fibroblasts which leads to uncontrolled scarring. 

When macrophages did not express WWP2, on the other hand, the team observed reduced infiltration of pro-fibrotic macrophages into the heart, and the action of repair macrophages was better sustained with clear beneficial effects on cardiac tissue and function during the later stages of the disease.

Blocking WWP2's function in this subset of cardiac macrophages is enough to slow—or even stop—the scarring. The team is developing a small molecule inhibitor against WWP2 that can achieve just that.

Huimei Chen et al, The E3 ubiquitin ligase WWP2 regulates pro-fibrogenic monocyte infiltration and activity in heart fibrosis, Nature Communications (2022). DOI: 10.1038/s41467-022-34971-6

Comment by Dr. Krishna Kumari Challa on December 10, 2022 at 8:59am

Now just a light beam can detect malaria

A fast, needle-free malaria detection tool developed by research team could help save hundreds of thousands of lives annually.

Malaria is usually detected by a blood test, but scientists have devised a method using a device that shines a beam of harmless infrared light on a person's ear or finger for five-to-10 seconds, it collects an infrared signature that is processed by a computer algorithm.

The technique is chemical-free, needle-free and detects malaria through the skin using infrared-light—it's literally just a flash on a person's skin and it's done.

"The device is smart-phone operated, so results are acquired in real time."

The researchers think the technology is the first step to eliminating malaria.

The technology could also help tackle other diseases. Because the researchers have successfully used this technology on mosquitoes to non-invasively detect infections such as malaria, Zika and dengue.

Gabriela A Garcia et al, Malaria absorption peaks acquired through the skin of patients with infrared light can detect patients with varying parasitemia, PNAS Nexus (2022). DOI: 10.1093/pnasnexus/pgac272

Comment by Dr. Krishna Kumari Challa on December 10, 2022 at 8:54am

Paper-thin solar cell can turn any surface into a power source

Comment by Dr. Krishna Kumari Challa on December 8, 2022 at 11:19am

For the new study, researchers set out to study if the viral proteins known to be targeted by T cells induced by VACV vaccination, would also be conserved in JYNNEOS and in mpox.

While antibodies are key for vaccine efficacy and preventing reinfections, T cells are essential for both preventing severe infections and "remembering" past infections.

By recognizing infected cells, T cells are able to limit how much viruses can spread inside the body modulate disease severity, and ultimately terminate the infection. T cell responses also tend to be long lasting, and resilient to viral mutations to escape immune recognition. What we have seen in the context of SARS-CoV-2 is that even if the virus mutates somewhat, T cells reactivity is still largely preserved.

The researchers demonstrated that the known targets of T cell responses seen in the VACV proven -efficacy vaccine, are also found in JYNNEOS and mpox, suggesting that the JYNNEOS vaccine can indeed trigger an effective T cell response against mpox infection. The initial test of their hypothesis was based on developing viral peptide "megapools," or reagents designed to detect T cell reactivity to mpox antigens. The experiments further showed that these megapools can be used to accurately detect specific T cells.

Vaccines such as JYNNEOS should be able to induce T cells that also recognize mpox and can provide protection from severe disease. 

 Alba Grifoni et al, Defining antigen targets to dissect vaccinia virus and monkeypox virus-specific T cell responses in humans, Cell Host & Microbe (2022). DOI: 10.1016/j.chom.2022.11.003

Part 2

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