Comment

Comment by Dr. Krishna Kumari Challa on Friday

Cellular assays measured oxidative stress, antioxidant protein expression, nitric oxide bioavailability, endothelin production, and fibrinolytic capacity. Capillary electrophoresis immunoassay and ELISA were used to quantify expression of superoxide dismutase-1 (SOD-1), catalase, endothelial nitric oxide synthase (eNOS), phosphorylated eNOS, endothelin-1 (ET-1), and tissue-type plasminogen activator (t-PA).

Cells exposed to erythritol exhibited a substantial increase in oxidative stress. Reactive oxygen species levels rose by approximately 75% relative to untreated controls. Antioxidant defense markers were also elevated, with SOD-1 expression increasing by approximately 45% and catalase by approximately 25%.

Nitric oxide production declined by nearly 20% in response to erythritol. Although total eNOS expression remained unchanged, phosphorylation at the Ser1177 site, which is associated with enzymatic activation, fell by approximately 33%. In contrast, phosphorylation at the inhibitory Thr495 site increased by approximately 39%.

In another test, t-PA release in response to thrombin stimulation was blunted in erythritol-treated cells, indicating reduced fibrinolytic responsiveness.

The researchers conclude that erythritol exposure disrupts multiple mechanisms vital to maintaining cerebral endothelial health. Although results are limited to acute in vitro conditions, the findings align with prior epidemiological associations between erythritol and elevated stroke risk.

Auburn R. Berry et al, The Non-Nutritive Sweetner Erythritol Adversely Affects Brain Microvascular Endothelial Cell Function, Journal of Applied Physiology (2025). DOI: 10.1152/japplphysiol.00276.2025

Part 2

Comment by Dr. Krishna Kumari Challa on Friday

Major sugar substitute found to impair brain blood vessel cell function, posing potential stroke risk

Erythritol may impair cellular functions essential to maintaining brain blood vessel health, according to researchers. Findings suggest that erythritol increases oxidative stress, disrupts nitric oxide signaling, raises vasoconstrictive peptide production, and diminishes clot-dissolving capacity in human brain microvascular endothelial cells.

Erythritol has become a fixture in the ingredient lists of protein bars, low-calorie beverages, and diabetic-friendly baked goods. Its appeal lies in its sweetness-to-calorie ratio, roughly 60–80% as sweet as sucrose with a tiny fraction of the energy yield, and its negligible effect on blood glucose. Erythritol is also synthesized endogenously from glucose and fructose via the pentose phosphate pathway, leaving baseline levels subject to both dietary and metabolic influences.

Concerns about erythritol's safety have escalated following epidemiological studies linking higher plasma concentrations with increased cardiovascular and cerebrovascular events. Positive associations between circulating erythritol and incidence of heart attack and stroke have been observed in U.S. and European cohorts, independent of known cardiometabolic risk factors. 

In the study, "The Non-Nutritive Sweetener Erythritol Adversely Affects Brain Microvascular Endothelial Cell Function," published in the Journal of Applied Physiology, researchers designed in vitro experiments to test the cellular consequences of erythritol exposure on cerebral endothelial function.

Human cerebral microvascular endothelial cells were cultured and exposed to an amount of erythritol equivalent to consuming a typical beverage. Experimental conditions included five biological replicates per group.

Part 1

Comment by Dr. Krishna Kumari Challa on Friday

New therapeutic strategy designed to help lower cholesterol levels

When the amount of cholesterol in the blood is too high, hypercholesterolemia can develop, causing serious damage to the arteries and cardiovascular health. Now, a study presents a new therapeutic tool capable of regulating blood cholesterol levels and thus opening up new perspectives in the fight against atherosclerosis caused by the accumulation of lipid plaques in the artery walls.

Specifically, the team has designed a strategy to inhibit the expression of PCSK9, a protein that plays a decisive role in modulating plasma levels of low-density lipoprotein cholesterol (LDL-C). The new method, based on the use of molecules known as polypurine hairpins (PPRH), facilitates the uptake of cholesterol by cells and prevents it from accumulating in the arteries without causing the side effects of the most common statin-based medication.

Ester López-Aguilar et al, Inhibition of PCSK9 with polypurine reverse hoogsteen hairpins: A novel gene therapy approach, Biochemical Pharmacology (2025). DOI: 10.1016/j.bcp.2025.116976

Comment by Dr. Krishna Kumari Challa on Thursday

In utero exposure to climate disasters linked to changes in child brain development

Climate disasters may be leaving invisible imprints on developing brains before birth, according to new research.

 Scientists discovered that children whose mothers experienced Superstorm Sandy during pregnancy showed distinct brain differences that could affect their emotional development for years to come.

The study, published in PLOS One, reveals that prenatal exposure to extreme climate events, particularly when combined with extreme heat, appears to rewrite critical emotion regulation centers in the developing brain. We're seeing how climate change may be reshaping the next generation's brains before they even take their first breath. These children's brains bear invisible scars from climate disasters they never personally experienced.

The research team analyzed brain imaging data from a group of 8-year-old children whose mothers were pregnant during Superstorm Sandy, which devastated parts of New York and other coastal regions in 2012. The scans revealed that children exposed to the storm in utero had significantly larger volumes in the basal ganglia, deep brain structures involved in emotion regulation.

The combination of storm stress and extreme heat created a perfect neurological storm in developing brains.

The researchers found that while extreme heat alone didn't significantly alter brain volume, when combined with the stress of living through a major storm during pregnancy, it amplified the effects dramatically.

As extreme weather events become more frequent and severe, we need to consider the invisible toll on future generations, the researchers say.

Donato DeIngeniis et al, Prenatal exposure to extreme ambient heat may amplify the adverse impact of Superstorm Sandy on basal ganglia volume among school-aged children, PLOS One (2025). DOI: 10.1371/journal.pone.0324150

Comment by Dr. Krishna Kumari Challa on Thursday

Your gut microbiome could be a calorie 'super harvester'!

In the jungle of microbes living in your gut, there's one oddball that makes methane. This little-known methane-maker might play a role in how many calories you absorb from your food, according to a new study.

The entire ecosystem of microbes is called the microbiome. Some people's gut microbiomes produce a lot of methane, while others produce hardly any.

The study found that people whose gut microbiomes produce a lot of methane are especially good at unlocking extra energy from a high-fiber diet. This may help explain why different individuals get different amounts of calories from food that makes it to the colon.

The researchers note that high-fiber diets are not the villain here. People absorb more calories overall from a Western diet of processed foods, regardless of methane production. On a high-fiber diet, people absorb fewer calories overall—but the amount varies according to methane production.

That difference has important implications for diet interventions. It shows people on the same diet can respond differently. Part of that is due to the composition of their gut microbiome.

The study, published in The ISME Journal, found that methane-producing microbes called methanogens are associated with a more efficient microbiome and higher energy absorption from food.

One of the microbiome's main jobs is helping to digest food. Microbes ferment fiber into short-chain fatty acids, which the body can use for energy. In the process, they produce hydrogen. Too much hydrogen pauses their activity, but other microbes can help keep this process going by using up the hydrogen.

Methanogens are hydrogen-eaters. As they consume hydrogen, they create methane. They are the only microbes to make this chemical compound.

The human body itself doesn't make methane, only the microbes do. So researchers suggested it can be a biomarker that signals efficient microbial production of short-chain fatty acids.

The research suggests that these microbe interactions affect the body's metabolism. The team found that higher methane production was associated with more short-chain fatty acids being made and absorbed in the gut.

Insights from this study could be a foundation for personalized nutrition.

Blake Dirks et al, Methanogenesis associated with altered microbial production of short-chain fatty acids and human-host metabolizable energy, The ISME Journal (2025). DOI: 10.1093/ismejo/wraf103

Comment by Dr. Krishna Kumari Challa on Thursday

Green light activates modified penicillin only where it's needed

To treat bacterial infections, medical professionals prescribe antibiotics. But not all active medicine gets used up by the body. Some of it ends up in wastewater, where antimicrobial-resistant bacteria can develop.

Now, to make a more efficient antibiotic treatment, researchers have modified penicillin, so that it's activated only by green light. In early tests, the approach precisely controlled bacterial growth and improved survival outcomes for infected insects.

Controlling drug activity with light will allow precise and safe treatment of localized infections. Moreover, the fact that light comes in different colors gives us the ability to take the spatial control of drug activity to the next level.

Scientists can add a light-sensitive molecule to drug compounds to keep them inactive in the body until they're needed. When light shines on a modified compound, the extra molecule breaks away and then releases the active drug. This process gives scientists precise control over when and where drugs are activated.

Green-Light-Activatable Penicillin for Light-Dependent Spatial Control of Bacterial Growth, Biofilm Formation, and In Vivo Infection Treatment, ACS Central Science (2025). DOI: 10.1021/acscentsci.5c00437

Comment by Dr. Krishna Kumari Challa on Thursday

The Moon's shiny Glass Beads

The Apollo astronauts didn't know what they'd find when they explored the surface of the moon, but they certainly didn't expect to see drifts of tiny, bright orange and black glass beads glistening among the otherwise monochrome piles of rocks and dust.

The beads, each less than 1 mm across, formed some 3.3 to 3.6 billion years ago during volcanic eruptions on the surface of the then-young satellite. They're some of the most amazing extraterrestrial samples the astronauts brought home.

 "The beads are tiny, pristine capsules of the lunar interior."

Using a variety of microscopic analysis techniques not available when the Apollo astronauts first returned samples from the moon,  a team of researchers have been able to take a close look at the microscopic mineral deposits on the outside of lunar beads. The unprecedented view of the ancient lunar artifacts was published in Icarus. 

The study relied, in part, on the NanoSIMS 50, an instrument at WashU that uses a high-energy ion beam to break apart small samples of material for analysis. WashU researchers have used the device for decades to study interplanetary dust particles, presolar grains in meteorites, and other small bits of debris from our solar system.

The study combined a variety of techniques—atom probe tomography, scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray spectroscopy—at other institutions to get a closer look at the surface of the beads.

Each glass bead tells its own story of the moon's past. The beads—some shiny orange, some glossy black—formed when lunar volcanoes shot material from the interior to the surface, where each drop of lava solidified instantly in the cold vacuum that surrounds the moon.

The very existence of these beads tells us the moon had explosive eruptions.

The minerals (including zinc sulfides) and isotopic composition of the bead surfaces serve as probes into the different pressure, temperature and chemical environment of lunar eruptions 3.5 billion years ago. Analyses of orange and black lunar beads have shown that the style of volcanic eruptions changed over time.

T.A. Williams et al, Lunar volcanic gas cloud chemistry: Constraints from glass bead surface sublimates, Icarus (2025). DOI: 10.1016/j.icarus.2025.116607

Comment by Dr. Krishna Kumari Challa on June 10, 2025 at 11:57am

How can we use this knowledge with regard to humans?
One surprising thing about the bat study, the researchers said, is that bats do not have a natural barrier to cancer. Their cells can transform into cancer with only two "hits"—and yet because bats possess the other robust tumor-suppressor mechanisms described above, they survive.

Importantly, the authors said, they confirmed that increased activity of the p53 gene is a good defense against cancer by eliminating cancer or slowing its growth. Several anti-cancer drugs already target p53 activity and more are being studied.
Safely increasing the telomerase enzyme might also be a way to apply their findings to humans with cancer.

Fathima Athar et al, Limited cell-autonomous anticancer mechanisms in long-lived bats, Nature Communications (2025). DOI: 10.1038/s41467-025-59403-z

Part 2

Comment by Dr. Krishna Kumari Challa on June 10, 2025 at 11:54am

Why don't bats get cancer? Researchers discover protection from genes and strong immune systems

A study to look at why long-lived bats do not get cancer has broken new ground about the biological defenses that resist the disease.

Reporting in the journal Nature Communications, a  research team has found that four common species of bats have superpowers allowing them to live up to 35 years, which is equal to about 180 human years, without cancer.

Their key discoveries about how bats prevent cancer include:
Bats and humans have a gene called p53, a tumor-suppressor that can shut down cancer. (Mutations in p53, limiting its ability to act properly, occur in about half of all human cancers.) A species known as the "little brown" bat—found in Rochester and upstate New York—contains two copies of p53 and has elevated p53 activity compared to humans. High levels of p53 in the body can kill cancer cells before they become harmful in a process known as apoptosis. If levels of p53 are too high, however, this is bad because it eliminates too many cells. But bats have an enhanced system that balances apoptosis effectively.
An enzyme, telomerase, is inherently active in bats, which allows their cells to proliferate indefinitely. This is an advantage in aging because it supports tissue regeneration during aging and injury. If cells divide uncontrollably, though, the higher p53 activity in bats compensates and can remove cancerous cells that may arise.
Bats have an extremely efficient immune system, knocking out multiple deadly pathogens. This also contributes to bats' anti-cancer abilities by recognizing and wiping out cancer cells. As humans age, the immune system slows, and people tend to get more inflammation (in joints and other organs), but bats are good at controlling inflammation, too. This intricate system allows them to stave off viruses and age-related diseases.

Part 1

Comment by Dr. Krishna Kumari Challa on June 10, 2025 at 11:48am

Sexual selection: Human odor-based mating preferences do not guarantee gamete-level compatibility

A recent study  explored sexual selection in humans by investigating whether female odor-based mating preferences could predict how compatible male and female gametes are.

Major histocompatibility complex (MHC) genes are known to mediate sexual selection both at the individual and gamete level. Previous studies have shown that perceived body odor attractiveness is strongly affected by these genes. However, it has remained unclear whether MHC-based mating preferences are consistent prior and after copulation.

To study this, the researchers performed a full-factorial experiment where 10 women first ranked the attractiveness and intensity of body odor samples collected from 11 men, followed by an analysis of whether female body odor preferences in these same 110 male–female combinations predicted sperm performance in the presence of follicular fluid. The results are published in the journal Heredity.

An analysis of the total MHC similarity—including both classical and non-classical MHC genes—of the male-female combinations showed that women preferred the body odors of MHC-similar men, but that sperm motility was positively affected by the MHC dissimilarity of the male–female combinations.

Women showed a preference for the body odors of MHC-similar men. However, sperm from MHC-dissimilar men exhibited higher motility when exposed to female follicular fluid, suggesting that the most attractive males may not necessarily always be the most optimal partners in terms of fertilization success.

The results indicate that individual and gamete-level mate choice processes may in fact act in opposing directions, and that gamete-mediated mate choice may have a definitive role in disfavoring genetically incompatible partners from fertilizing oocytes.

 Annalaura Jokiniemi et al, Female-mediated selective sperm activation may remodel major histocompatibility complex-based mate choice decisions in humans, Heredity (2025). DOI: 10.1038/s41437-025-00759-9

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