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Comment by Dr. Krishna Kumari Challa on November 21, 2024 at 9:51am

Weight-loss drug found to shrink heart muscle in mice and human cells

Trendy weight-loss drugs making headlines for shrinking waistlines may also be shrinking the human heart and other muscles, according to a new  study in JACC: Basic to Translational Science. The authors say the research should serve as a "cautionary tale" about possible long-term health effects of these drugs.

Researchers set out to study why a reported side-effect of the leading weight-loss drug Ozempic is the loss of skeletal muscle.

Ozempic, known medically as semaglutide, was originally designed to help adult patients with type 2 diabetes control their blood sugar. However, this drug—and a host of others in this class of medication—are also being touted for their effectiveness as an anti-obesity medication.

Using mice for the study, the researchers found that heart muscle also decreased in both obese and lean mice. The systemic effect observed in mice was then confirmed in cultured human heart cells.

 Matthew D. Martens et al, Semaglutide Reduces Cardiomyocyte Size and Cardiac Mass in Lean and Obese Mice, JACC: Basic to Translational Science (2024). DOI: 10.1016/j.jacbts.2024.07.006

Comment by Dr. Krishna Kumari Challa on November 21, 2024 at 9:43am

Scientists discover the molecular composition of potentially deadly venomous fish

New research in FEBS Open Bio reveals insights into the venom of two of the most venomous fish species on Earth: the estuarine stonefish (Synanceia horrida) and the reef stonefish (Synanceia verrucosa), which are typically found in the warm and shallow regions of the Indo-Pacific region, the Persian Gulf, and the Red Sea.

Through multiple analytical techniques, investigators discovered the presence of three neurotransmitters new to stonefish venom, namely gamma-aminobutyric acid (GABA), choline, and 0-acetylcholine.

Although these molecules have been previously found in venoms from other species, such as hornets and spiders, this is the first report of a fish venom that contains GABA, which is capable of modulating cardiovascular function with a range of effects including increased heart rate and low blood pressure.

Characterization of the specific composition of each of these fish species' venom not only provides us with a better understanding of envenomation mechanisms, which are needed for the development of targeted treatments against venom effects, but may also aid in the exploration and development of venom-derived compounds in drug discovery.

Silvia Luiza Saggiomo et al, Interrogating stonefish venom: small molecules present in envenomation caused by Synanceia spp., FEBS Open Bio (2024). DOI: 10.1002/2211-5463.13926

Comment by Dr. Krishna Kumari Challa on November 21, 2024 at 9:33am

Ethiopian wolves seen feeding on nectar of red hot poker flowers

Strange things happen in nature!

New findings, published in the journal Ecology, describe a newly documented behavior of Ethiopian wolves (Canis simensis).

Researchers observed Ethiopian wolves foraging for the nectar of the Ethiopian red hot poker (Kniphofia foliosa) flower. Some individuals would visit as many as 30 blooms in a single trip, with multiple wolves from different packs exploiting this resource. There is also some evidence of social learning, with juveniles being brought to the flower fields along with adults.

In doing so, the wolves' muzzles become covered in pollen, which they could potentially transfer from flower to flower as they feed. This novel behavior is perhaps the first known plant-pollinator interaction involving a large predator, as well as the only large meat-eating predator ever to be observed feeding on nectar.

Sandra Lai et al, Canids as pollinators? Nectar foraging by Ethiopian wolves may contribute to the pollination of Kniphofia foliosa, Ecology (2024). DOI: 10.1002/ecy.4470

Comment by Dr. Krishna Kumari Challa on November 21, 2024 at 9:18am

'Flame-Throwing' Guitar Nebula

Comment by Dr. Krishna Kumari Challa on November 21, 2024 at 8:51am

Astronauts found to process some tasks slower in space, but no signs of permanent cognitive decline

A stay in space exerts extreme pressures on the human body. Astronauts' bodies and brains are impacted by radiation, altered gravity, challenging working conditions, and sleep loss—all of which could compromise cognitive functioning. At the same time, they are required to perform complex tasks, and minor mistakes can have devastating consequences.

Working with 25 astronauts who spent an average of six months on the International Space Station (ISS), researchers  have examined changes in a wide range of cognitive performance domains. This dataset makes up the largest sample of cognitive performance data from professional astronauts published to date.

The research shows that there is no evidence of any significant cognitive impairment or neurodegenerative decline in astronauts spending six months on the ISS. Living and working in space was not associated with widespread cognitive impairment that would be suggestive of significant brain damage.

The results showed that responses to tasks assessing processing speed, working memory, and attention were slower than on Earth, but they were no less accurate. These changes, however, did not persist equally long.

Slowed performance on attention, for example, was only observed early during the mission, while slowed performance on processing speed did not return to baseline levels until after the mission ended and the crew were back on Earth.

Overall, astronauts' cognitive performance was stable, and the researchers did not find evidence that would suggest damage to the central nervous system during a six-month space mission.

Cognitive Performance in ISS Astronauts on 6-month Low Earth Orbit Missions, Frontiers in Physiology (2024). DOI: 10.3389/fphys.2024.1451269

Comment by Dr. Krishna Kumari Challa on November 21, 2024 at 8:31am

These networks shared a common feature: Each molecular network had two forms of "memory" storage that captured information learned from the environment. One memory decayed much faster than the other -- a form of memory loss necessary for habituation, the researchers noted. This finding suggests that single cells process and remember information over different time spans.

Studying habituation in single cells could help propel understanding of how learning in general works, the researchers said. The findings also cast the humble single-cell creatures in a new, more tantalizing light: They are not merely molecular machines packed in microscopic bodies, but they are also agents that can learn.

Practical applications of this work:

One daring idea would be to apply the concept of habituation to the relationship between cancer and immunity.

Tumors are notoriously good evaders of immune surveillance because they trick immune cells into viewing them as innocent bystanders. In other words, the immune cells responsible for recognizing cancer may get somehow habituated to the presence of a cancer cell -- the immune cell gets used to the stimulus and no longer responds to it.

If we knew how these false perceptions get encoded in immune cells, we may be able to re-engineer them so that immune cells begin to perceive their environments correctly, the tumor becomes visible as malign, and they get to work.

Lina Eckert, Maria Sol Vidal-Saez, Ziyuan Zhao, Jordi Garcia-Ojalvo, Rosa Martinez-Corral, Jeremy Gunawardena. Biochemically plausible models of habituation for single-cell learning. Current Biology, 2024; DOI: 10.1016/j.cub.2024.10.041

Part 2

Comment by Dr. Krishna Kumari Challa on November 21, 2024 at 8:31am

Research reveals even single-cell organisms exhibit habituation, a simple form of learning

Up until recently, habituation -- a simple form of learning -- was deemed the exclusive domain of complex organisms with brains and nervous systems, such as worms, insects, birds, and mammals. But a new study offers compelling evidence that even tiny single-cell creatures such as ciliates and amoebae, as well as the cells in our own bodies, could exhibit habituation akin to that seen in more complex organisms with brains.

A dog learns to sit on command, a person hears and eventually tunes out the hum of a washing machine while reading … The capacity to learn and adapt is central to evolution and, indeed, survival.

Habituation involves the lessening response to a stimulus after repeated exposure. Think of the need for a third espresso to maintain the same level of concentration you once achieved with a single shot.

Up until recently, habituation -- a simple form of learning -- was deemed the exclusive domain of complex organisms with brains and nervous systems, such as worms, insects, birds, and mammals.

But a new study, published Nov. 19 in Current Biology, offers compelling evidence that even tiny single-cell creatures such as ciliates and amoebae, as well as the cells in our own bodies, could exhibit habituation akin to that seen in more complex organisms with brains.

This finding opens up an exciting new mystery for us: How do cells without brains manage something so complex?

The results add to a small but growing body of work on this subject. Earlier work led by Gunawardena found that a single-cell ciliate showed avoidance behavior, not unlike the actions observed in animals that encounter unpleasant stimuli.

Instead of studying cells in a lab dish, the scientists used advanced computer modeling to analyze how molecular networks inside ciliate and mammalian cells respond to different patterns of stimulation. They found four networks that exhibit hallmarks of habituation present in animal brains.

Part1

Comment by Dr. Krishna Kumari Challa on November 21, 2024 at 8:30am

Above a certain cell density, synNotch exerted a weaker effect and didn't produce the same patterns. Further complicating matters, cell density constantly shifted as cells proliferated at ever changing rates—interacting in complex ways with the synNotch genetic circuit.

The scientists then built a computational model that could predict and clarify this complex and dynamic cell behaviour. It helped guide them to think about how the cell density, proliferation rate, signaling, and all these different things conspire.

Guided by the computational model, the scientists were able to use cell density to generate a variety of predictable fluorescent patterns that developed over specific timeframes.

To understand how cell density was exerting these effects, the scientists conducted a series of experiments that yielded a surprising discovery. Greater cell density induces stress that leads to a quicker breakdown of not only synNotch in particular, but also cell surface sensors in general.

This means that cell density is a broadly applicable tool for guiding both engineered and naturally occurring cells to build a vast array of structures, tissues, and organs.

Nature has relied on cell density in conjunction with genetic circuits to generate the remarkable diversity of multicellular structures, tissues, and organs.

Now we can co-opt this same strategy to advance our efforts to build synthetic multicellular structures—and eventually tissues and organs—for regenerative medicine, say the scientists.

Nature Communications (2024). DOI: 10.1038/s41467-024-53078-8

Part 2

Comment by Dr. Krishna Kumari Challa on November 21, 2024 at 8:30am

By exerting 'crowd control' over mouse cells, scientists make progress towards engineering tissues
Genes aren't the sole driver instructing cells to build multicellular structures, tissues, and organs. In a paper published in Nature Communications, scientists characterize the influence of another important developmental driver: cell density, or how loosely or tightly cells are packed into a given space.

In both computational models and laboratory experiments, the team of scientists used cell density as an effective tool for controlling how mouse cells pattern themselves into complex structures.

This paper represents progress towards their big picture goal of engineering synthetic tissues. Synthetic tissues could have endless medical applications, ranging from testing potential drugs or therapies to providing grafts or transplants for patients.

The study used two types of mouse cells—connective tissue cells and stem cells—engineered to carry a synthetic cellular communication system or "genetic circuit. This circuit is based on something they developed called "synNotch," which is a protein that scientists genetically engineer into a cell to serve as a "sensor."

Located on a cell's surface, this protein-based sensor recognizes an external signal that triggers the cell to respond—usually by turning on a user-defined gene.

For this particular series of experiments, the scientists used synNotch to turn on a circuit that includes green fluorescence and a way to propagate the signal further—although it could be used to turn on any gene. The fluorescence made it easy to observe cells as they formed patterns. For example, in a field of cells, scientists could create a pattern of green fluorescent rings emanating from a central point.

While conducting these experiments, the scientists noticed that genetically identical cells did not always produce the same patterns.

So that was puzzling at the beginning. When the researchers looked at it more carefully, they started seeing that there was a gradient of cell density that seemed to correlate with differences in patterning.

Part 1

Comment by Dr. Krishna Kumari Challa on November 21, 2024 at 8:30am

High exposure to everyday chemicals linked to asthma risk in children

A new study by researchers at Kumamoto University sheds light on a potential link between exposure to certain everyday chemicals during pregnancy and the development of asthma in children. The study analyzed data from over 3,500 mother-child pairs as part of the Japan Environment and Children's Study (JECS), a large-scale nationwide research project.

researchers measured 24 types of phenols in urine samples collected from pregnant women. They then tracked the health of their children until the age of four.

The study is published in the journal Environmental Pollution.

High levels of butylparaben, a chemical commonly used in personal care products like lotions and shampoos, during early pregnanacy were associated with a 1.54-fold increase in the odds of asthma development in children (Odds Ratio: 1.54).

Exposure to 4-nonylphenol, a chemical found in some cleaning products and plastics, showed a striking gender-specific effect. Boys born to mothers exposed to this chemical had 2.09 times higher odds of developing asthma, while no such association was observed in girls.

Phenols, including parabens and alkylphenols, are widely used in consumer products for their preservative and antimicrobial properties. While their use is considered safe in small amounts, their potential as endocrine disruptors raises concerns about long-term health effects, such as the recent increase in allergenic diseases such as asthma, particularly during sensitive periods like pregnancy.

The findings highlight the importance of understanding how everyday chemical exposures might contribute to respiratory and allergic conditions in children.

Shohei Kuraoka et al, Association of phenol exposure during pregnancy and asthma development in children: The Japan Environment and Children's study, Environmental Pollution (2024). DOI: 10.1016/j.envpol.2024.124801

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