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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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Comment by Dr. Krishna Kumari Challa on December 8, 2022 at 11:16am

Scientists confirm smallpox vaccine also teaches T cells to fight mpox

There's even more reason to think a vaccine developed against smallpox can help the body fight against mpox (monkeypox virus disease) as well, according to researchers. A new study, published in Cell Host & Microbe, is the first to provide evidence that the vaccinia vaccine MVA-BN (brand name JYNNEOS) should also train virus-fighting T cells to recognize mpox sequences.

This study gives us confidence that T cell response induced by the JYNNEOS vaccine should be able to also recognize mpox virus.

Although the JYNNEOS vaccine, based on a non-live attenuated orthopox virus called modified vaccine ankara (MVA), is approved to prevent mpox infection and severe disease, researchers don't yet have clinical efficacy data from human trials. Still, researchers know that mpox virus is similar enough to other orthopoxviruses that immunization against an orthopoxvirus called vaccinia (VACV) can also train the immune system to fight mpox.

Mpox (termed "monkeypox" until recently) is a member of the orthopox family of viruses. The deadliest, of course, was variola virus,causing the disease known as smallpox. Smallpox was eradicated worldwide in 1980 thanks to a massive and successful vaccination campaign to administer the Dryvax vaccine, based on VACV.

VACV and variola virus have a lot of immune system targets (called antigens), in common. This means training the body to recognize VACV also taught immune cells to recognize variola virus. But there was a downside—Dryvax (and a newer version called Acambis 2000) had harmful side effects, especially in immunocompromised people.

JYNNEOS was designed to have a better safety profile. While the vaccine performed well in pre-clinical tests, the eradication of smallpox meant scientists couldn't see how JYNNEOS performed in human patients in real-world infection scenarios, such as a smallpox outbreak or possible case of smallpox-based biological warfare.

Part 1

Comment by Dr. Krishna Kumari Challa on December 8, 2022 at 11:06am

Governments and people around the world, please listen: It is risky bet on forests and soils to reach net zero emissions

New research  highlights the risks of countries relying on nature-based solutions to achieve net zero.

National climate strategies set out how countries plan to reduce emissions, for example by phasing out fossil fuel use, to get to net zero in 2050. The study found that once the bulk of emissions have been reduced, countries plan to "cancel out" the leftover difficult-to-decarbonize emissions, such as those from agriculture, by using forests and soils to remove carbon from the atmosphere.

However, this may prove risky because forests and soils are also threatened by a range of impacts, such as fire, disease, changes in farming practices, and deforestation. These threats mean that forests and soils could lose their stored carbon back to the atmosphere.

There is also a risk of being overly optimistic about the amount of carbon that forests and soils can remove to reach net zero, especially if combined with delays to reducing emissions from coal, oil, and gas.

The findings, published in the journal Communications Earth & Environment, show that most of the strategies submitted to the United Nations Framework Convention on Climate Change (UNFCCC) do not quantify the amount of carbon "removals" needed in 2050.

With progress on reducing emissions stalling at COP27, the researchers call for the reporting requirements on long-term national climate plans to be urgently strengthened.

The deployment of carbon dioxide removal is essential to reach global and national net zero emissions targets, but little attention has been paid to its practical deployment by countries. 

Nature-based removals, such as using forests and soils, remain vital to address challenges in biodiversity and climate adaptation, but may be risky if used as the only way to remove carbon. Countries should also explore engineered carbon removal methods. To meet the challenge of net zero, we need both.

'Long-term National Climate Strategies Bet on Forests and Soils to Reach Net-Zero', Communications Earth & Environment (2022).

Comment by Dr. Krishna Kumari Challa on December 8, 2022 at 9:47am

New branch on tree of life includes 'lions of the microbial world'

There's a new branch on the tree of life and it's made up of predators that nibble their prey to death.

These microbial predators fall into two groups, one of which researchers have dubbed "nibblerids" because they, well, nibble chunks off their prey using tooth-like structures. The other group, nebulids, eat their prey whole. And both constitute a new ancient branch on the tree of life called Provora, according to a paper published today in Nature.

Like lions, cheetahs, and more familiar predators, these microbes are numerically rare but important to the ecosystem. Using water samples from marine habitats around the world, including the coral reefs of Curaçao, sediment from the Black and Red seas, and water from the northeast Pacific and Arctic oceans, the researchers discovered new microbes.

Culturing these microbial predators was no mean feat, since they require a mini-ecosystem with their food and their food's food just to survive in the lab.

Denis Tikhonenkov, Microbial predators form a new supergroup of eukaryotes, Nature (2022). DOI: 10.1038/s41586-022-05511-5. www.nature.com/articles/s41586-022-05511-5

Comment by Dr. Krishna Kumari Challa on December 8, 2022 at 9:42am

Discovery of world's oldest DNA breaks record by one million years

Two-million-year-old DNA has been identified for the first time—opening a 'game-changing' new chapter in the history of evolution.

Microscopic fragments of environmental DNA were found in Ice Age sediment in northern Greenland. Using cutting-edge technology, researchers discovered the fragments are one million years older than the previous record for DNA sampled from a Siberian mammoth bone.

The ancient DNA has been used to map a two-million-year-old ecosystem which weathered extreme climate change. Researchers hope the results could help to predict the long-term environmental toll of today's global warming.

Extensive work by 40 researchers from several countries  unlocked the secrets of the fragments of DNA. The process was painstaking—first they needed to establish whether there was DNA hidden in the clay and quartz, and if there was, could they successfully detach the DNA from the sediment to examine it? The answer, eventually, was yes. The researchers compared every single DNA fragment with extensive libraries of DNA collected from present-day animals, plants and microorganisms. A picture began to emerge of the DNA from trees, bushes, birds, animals and microorganisms.

Some of the DNA fragments were easy to classify as predecessors to present-day species, others could only be linked at genus level, and some originated from species impossible to place in the DNA libraries of animals, plants and microorganisms still living in the 21st century.

The two-million-year-old samples also help academics build a picture of a previously unknown stage in the evolution of the DNA of a range of species still in existence today.

Eske Willerslev, A 2-million-year-old ecosystem in Greenland uncovered by environmental DNA, Nature (2022). DOI: 10.1038/s41586-022-05453-y. www.nature.com/articles/s41586-022-05453-y

Comment by Dr. Krishna Kumari Challa on December 7, 2022 at 10:10am

This is what we wanted: EU agrees ban on imports driving deforestation

The European Union reached an agreement yesterday to ban the import of products including coffee, cocoa and soy in cases where they are deemed to contribute to deforestation.

The draft law, which aims to ensure "deforestation-free supply chains" for the 27-nation EU, was hailed by environmental groups as "groundbreaking".

It requires companies importing into the EU to guarantee products are not produced on land that suffered deforestation after December 31, 2020, and that they comply with all laws of the source country.

The scope encompasses palm oil, cattle, soy, coffee, cocoa, timber and rubber as well as derived products such as beef, furniture and chocolate.

Illegal production has spurred massive deforestation in countries such as Brazil, Indonesia, Malaysia, Nigeria, the Democratic Republic of Congo, Ethiopia, Mexico and Guatemala.

The United Nations' Food and Agriculture Organization estimates that an aggregate area of land bigger than the European Union, or some 420 million hectares (more than one billion acres), has been deforested around the world over the past three decades.

The law opened the way for technology such as satellite monitoring and DNA analysis to verify the provenance of targeted imports. The legislation would be reviewed one year after coming into force, to see whether it should be extended to other wooded land. Another review at the two-year mark would have the commission considering whether to expand it to cover other ecosystems and commodities, as well as financial institutions.

WWF, called the agreement "groundbreaking" and "historic".

source: AFP

Comment by Dr. Krishna Kumari Challa on December 6, 2022 at 10:51am

Insulin sensitivity is preserved in mice made obese by feeding a high starch diet

Abstract: Obesity is generally associated with insulin resistance in liver and muscle and increased risk of developing type 2 diabetes, however there is a population of obese people that remain insulin sensitive. Similarly, recent work suggests that mice fed high carbohydrate diets can become obese without apparent glucose intolerance. To investigate this phenomenon further, we fed mice either a high fat (Hi-F) or high starch (Hi-ST) diet and measured adiposity, glucose tolerance, insulin sensitivity, and tissue lipids compared to control mice fed a standard laboratory chow. Both Hi-ST and Hi-F mice accumulated a similar amount of fat and tissue triglyceride compared to chow-fed mice. However, while Hi-F diet mice developed glucose intolerance as well as liver and muscle insulin resistance (assessed via euglycaemic/hyperinsulinaemic clamp), obese Hi-ST mice maintained glucose tolerance and insulin action similar to lean, chow-fed controls. This preservation of insulin action despite obesity in Hi-ST mice was associated with differences in de novo lipogenesis and levels of C22:0 ceramide in liver and C18:0 ceramide in muscle. This indicates that dietary manipulation can influence insulin action independently of the level of adiposity and that the presence of specific ceramide species correlates with these differences.

https://elifesciences.org/articles/79250?utm_source=content_alert&a...

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