Comment

Comment by Dr. Krishna Kumari Challa on January 24, 2025 at 8:33am

Uncovering the role of Y chromosome genes in male fertility in mice

Researchers at the Crick have uncovered which genes on the Y chromosome regulate the development of sperm and impact fertility in male mice. This research could help us understand why some men don't produce enough sperm and are infertile.

Males typically have one copy of the Y chromosome and one copy of the X chromosome, whereas females typically have two X chromosomes. Scientists know that the Y chromosome is essential for male fertility, but which genes are the most important and how they work is less clear till now.

In research published in Science, a research team at the Crick resolved this question by generating 13 different mouse models, each with different Y genes removed, and investigated their fertility.

The researchers studied the ability of these adult mice to reproduce, including looking at the number of offspring, number of sperm produced and the appearance and motility of the sperm.

They found that several Y genes were critical for reproduction. If these genes were removed, the mice couldn't produce young, due to absence or reduced number of sperm, failure to produce a reservoir of sperm stem cells or abnormal sperm shape or movement.

Interestingly, some other genes had no impact when removed individually, but did lead to the production of abnormal sperm when removed together.

This was the case for a group of three genes which model a region of the chromosome called AZFa in humans. AZFa deletions are a common cause of the most severe cases of male infertility, but it has been hard to tell which genes in the region are responsible.

The results suggest that many Y genes play a role in fertility and can compensate for each other if one gene is lost. This also means that some cases of infertility likely result from multiple genes being deleted at the same time.

As well as regulating sperm generation, some Y genes are also active in other organs, like the heart and the brain, where they may be very important. Also, as they age, some men can lose their Y chromosomes in blood due to errors in cell division. 

This loss is associated with conditions like Alzheimer's disease or cancer, so the lab is now aiming to understand what happens in other organs in the mice with Y gene deletions.

Infertility is a big problem, with one in six couples struggling to conceive. In a significant proportion of cases,genetic factors, particularly those involving the Y chromosome, are the cause.

Now that scientists have shed light on the Y genes, it will be important to start sequencing the Y chromosome in more individuals, to potentially uncover unexplained causes of male infertility. With more research, we may be able to one day replace missing genes in the cells that make sperm to help couples have children through IVF.

Jeremie Subrini et al, Systematic identification of Y-chromosome gene functions in mouse spermatogenesis, Science (2025). DOI: 10.1126/science.ads6495. www.science.org/doi/10.1126/science.ads6495

Comment by Dr. Krishna Kumari Challa on January 23, 2025 at 11:43am

Insulin-producing cells avoid immune attack

Gene-edited insulin-producing beta cells have survived for a month after being injected into a man with type 1 di.... These tweaked cells have a protein called CD47 on their surface, which tells the immune system not to destroy them. Only a small number of cells were injected into the man’s arm, but they have produced insulin and avoided his immune system’s crosshairs so far, suggesting that they could become an effective treatment for diabetes.

https://ir.sana.com/news-releases/news-release-details/sana-biotech...

https://www.newscientist.com/article/2463508-gene-edited-cells-that...

Comment by Dr. Krishna Kumari Challa on January 23, 2025 at 9:38am

Silver nanoparticles in packaging can contaminate dry foods, testing shows

A team of research scientists has found evidence of silver nanoparticles embedded in packaging used as an antimicrobial agent seeping into the dry food it is meant to protect. In their paper published in the journal ACS Food Science & Technology, the group describes how they created their own packaging with embedded silver nanoparticles and tested it with various foods, and what they learned by doing so.

Silver has been a known antimicrobial agent for centuries, but it has only recently been made into nanoparticle-sized grains for use in food packaging. Prior research has shown that when such packaging is used for liquid or gelatinous foods or beverages, the nanoparticles can easily seep into and permeate the food. It is still not known if such particles can cause harm to people who consume them—testing is still ongoing, which is why they are banned in many countries. In this new effort, the research team wanted to know if such particles also find their way into dry foods.

To find out, the team created samples of silver nanoparticles and embedded them in polyethylene film wraps, which could hold various types of food items. They tested wheat flour, slices of cheese, ground rice and spinach leaves. They then stored the packages in ways normal to consumers' homes.

The team then brought the packages into their lab for testing with mass spectrometry. In so doing, they found that the nanoparticles had made their way to all the foods, though to varying degrees. They found, for example, that there was far more contamination of the cheese than there was with the spinach leaves. They noted that the more surface contact between the food and the packaging, the more contamination. They also noted that most of the contamination was confined to the surface of the food, which meant that most of it could be easily rinsed away.

 Laxmi Adhikari et al, Silver Migrates to Solid Foods and Abiotic Surfaces from Model Plastic Packaging Containing Silver Nanoparticles, ACS Food Science & Technology (2025). DOI: 10.1021/acsfoodscitech.4c00813

Comment by Dr. Krishna Kumari Challa on January 23, 2025 at 8:51am

Fighting experience plays key role in brain chemical's control of male aggression

Like humans, mice will compete over territory and mates, and show increased confidence in their fighting skills the more they win. At first, a brain chemical called dopamine is essential for young males to master this behavior. But as they gain experience, the chemical grows less important in promoting aggression, a new study shows.

Dopamine has been linked to male aggression for decades. How past experiences might influence this relationship, however, had until now been unclear.

In experiments in rodents, a team led by researchers at NYU Langone Health boosted activity in dopamine-releasing cells in a part of the brain called the ventral tegmental area. The findings revealed that in inexperienced male fighters, this led the animals to attack for twice as long as they would have fought naturally. When the cells were blocked, the novice mice would not fight at all.

By contrast, this pattern did not hold true in males that had extensive fighting experience. Whether or not dopamine-releasing cells were boosted or blocked, the duration of the attack did not change. Notably, though, the more clashes a mouse won, the more fights it would start in the future.

These findings show that while aggression is an innate behaviour, dopamine—and fighting experience—is essential for its maturation during adulthood.

A report on the findings was published online Jan. 22 in the journal Nature.

Dayu Lin, Experience-dependent dopamine modulation of male aggression, Nature (2025). DOI: 10.1038/s41586-024-08459-w. www.nature.com/articles/s41586-024-08459-w

Comment by Dr. Krishna Kumari Challa on January 23, 2025 at 8:47am

The survey collected sociodemographic data, self-reported social media usage, and measures of irritability. Participants completed the Brief Irritability Test (BITe), which consists of five statements evaluating irritability symptoms over the previous two weeks. Scores range from 5 to 30, with higher scores indicating higher levels of irritability. The analysis also included depression and anxiety metrics to account for overlapping psychological symptoms.

Social media use was categorized based on frequency: never, less than once per week, once per week, several times per week, once per day, several times per day, or most of the day. Platforms analyzed included Facebook, Instagram, TikTok, and Twitter/X. Frequency of active posting, political engagement, and political affiliation were also examined to identify potential confounding factors.

Participants had a mean age of 46 years, with 58.5% identifying as women, 40.4% as men, and 1.1% as nonbinary. Among respondents, 78.2% reported daily use of at least one social media platform. Frequent social media use correlated with higher irritability scores, even after adjusting for anxiety and depression.

For example, participants using social media most of the day scored 3.37 points higher on the BITe in unadjusted models. After adjusting for anxiety and depression, the increase remained significant at 1.55 points.

Platform-specific analyses revealed a dose-response relationship between posting frequency and irritability. Posting multiple times per day was associated with the highest irritability levels across all platforms, with TikTok users showing the largest increase (1.94 points; 95% CI, 1.57-2.32 points).

Political engagement variables, such as frequent political posting or consuming political news, were associated with increased irritability. Political engagement did not diminish the observed relationship between social media use and irritability, though following political news "not very closely" was associated with a slight decrease.

High social media engagement levels, particularly frequent posting, were associated with greater irritability in US adults. While the study could not establish direct causation, findings suggest a potential feedback loop relationship, where irritability may both influence a desire to engage and increase irritation from social media use.

 Roy H. Perlis et al, Irritability and Social Media Use in US Adults, JAMA Network Open (2025). DOI: 10.1001/jamanetworkopen.2024.52807

Part 2

**

Comment by Dr. Krishna Kumari Challa on January 23, 2025 at 8:46am

Frequent social media use tied to higher levels of irritability

A survey led by researchers has analyzed the association between self-reported social media use and irritability among US adults. Frequent social media use, especially among active posters, was correlated with higher levels of irritability.

Existing studies on social media and mental health predominantly focus on depressive symptoms, with limited attention to other negative emotions such as irritability. Irritability, defined as a tendency toward anger and frustration, has been linked to functional impairments, poorer mental health outcomes, and suicidal behaviours.

While prior research has established connections between social media use and depressive symptoms, the extent to which social media engagement is associated with irritability or its influence on depression and anxiety has remained uncertain.

In the study, "Irritability and Social Media Use in US Adults," published in JAMA Network Open, the research team used data from two waves of the COVID States Project, a nationwide nonprobability web-based survey conducted between November 2, 2023, and January 8, 2024, which included questions about social media use and irritability.

Researchers evaluated the relationship between social media use and irritability by analyzing responses from 42,597 participants using multiple linear regression models.

Part 1

Comment by Dr. Krishna Kumari Challa on January 22, 2025 at 12:18pm

Paralysed man flies virtual drone using brain implant

Device that links neural signals to fine movements provides unprecedented control over speed and direction in a video-game obstacle course.

Paralysed man flies virtual drone
Researchers have developed a device that let a 69-year-old man with paralysis fly a virtual drone using only his thoughts. The brain–computer interface (BCI) decoded the man’s brain activity as he imagined moving three groups of digits in real time. By associating neural signals with the movements of multiple fingers, the work builds on previous BCI research, most of which has focused on moving a single computer cursor or whole virtual hand.

https://www.nature.com/articles/d41586-025-00167-3?utm_source=Live+...

Comment by Dr. Krishna Kumari Challa on January 22, 2025 at 11:59am

However, the only aldolase A inhibitor currently available has so far only been tested experimentally and is not approved as a drug. The Heidelberg team is now testing the substance for its potential in cancer therapy.

It is important to note that even a slight reduction in the activity of aldolase A could be enough to drive cancer cells into the energy trap.

Normal cells should tolerate this because they take up smaller amounts of glucose and produce less energy-rich fructose bisphosphate. The Warburg effect is therefore a weak point of cancer cells that makes them more sensitive to a blockade of aldolase A.

The results show how a deeper understanding of tumor metabolism can enable innovative approaches to cancer treatment. These findings could pave the way for new, highly specific therapies that target the weaknesses of cancer metabolism while sparing healthy cells.

Marteinn T. Snaebjornsson et al, Targeting aldolase A in hepatocellular carcinoma leads to imbalanced glycolysis and energy stress due to uncontrolled FBP accumulation, Nature Metabolism (2025). DOI: 10.1038/s42255-024-01201-w

Part 2

Comment by Dr. Krishna Kumari Challa on January 22, 2025 at 11:58am

An energy trap for tumor cells: Researchers find enzyme blockade halts liver cancer growth

Glycolysis is a central metabolic pathway by which cells obtain energy from sugar. Cancer cells in particular have long been thought to depend on the energy obtained through glycolysis, a phenomenon known as the Warburg effect. Today we know that cancer cells can use energy sources more flexibly than previously thought. Even when glycolysis is blocked, they survive by obtaining their energy through the respiratory chain.

This makes results published by Almut Schulze and colleagues from the German Cancer Research Center (DKFZ) all the more surprising: When the researchers blocked the enzyme aldolase A, which catalyzes an important step in glycolysis, liver cancer cells experienced "energy stress" and ceased their division activity. The team demonstrated this both in mouse liver cancer cells and in several human cancer cell lines.

The findings are published in the journal Nature Metabolism.

However, when the researchers blocked an earlier step in glycolysis, the enzyme glucose-6-phosphate isomerase, this had no effect on the growth of the cancer cells.

The glycolytic enzyme aldolase is essential for liver cancer cells, although the glycolytic pathway itself is apparently dispensable.

At first glance, the result seems surprising, since the enzyme blockade inhibits the sugar degradation pathway in both cases. However, a closer look at the biochemical steps of glycolysis provides clarity: The metabolic pathway, which involves many reactions, is divided into two parts. First, the cell has to invest energy to generate the highly energetic intermediate fructose-bisphosphate.

This is where aldolase A comes in. If it is switched off, fructose bisphosphate accumulates in the cell, and the energy bound in it remains unused, trapped as it is. The cell cannot reap the energy profit from the steps that would normally follow. Glycolysis has reversed from an energy-producing to an energy-consuming process. What's more, the lack of energy further stimulates the production of fructose bisphosphate, creating a vicious circle.

Sooner or later, this leads to energy consumption exceeding energy production. In liver cancer cells, this results in a massive energy deficiency, the cell cycle is stopped and tumor growth is inhibited. The team also demonstrated this in liver cancer-bearing mice: If the animals' aldolase A was genetically switched off, the cancer growth was reduced and the mice survived significantly longer.

By switching off Aldolase A, we can overcome the metabolic plasticity of cancer cells. We not only block energy production through glycolysis, but also prevent the cell from switching to other metabolic pathways, because the energy is trapped in the fructose bisphosphate. Targeted inhibition of aldolase A could therefore be a promising strategy for combating cancer cells.

Part 1

Comment by Dr. Krishna Kumari Challa on January 22, 2025 at 11:40am

New effective treatment for deadly pancreatic cancer may be on its way

Pancreatic cancer is one of the deadliest of all cancers. Only 12% of men diagnosed with pancreatic cancer are alive five years after diagnosis; for women it is 14%.

In pancreatic cancer, symptoms are unclear and often emerge late in its progression. It is difficult to treat once the cancer has spread, as it cannot be removed completely with surgery.

Now researchers  have made significant advances in developing a treatment for pancreatic cancer and a new study published in Science Advances depicts how it is done. The study is based on the ADC (antibody drug conjugates) technique, which is being used to treat other types of cancers.

This study shows promising results with a new type of drug that can fight the cancer on several fronts. The treatment directly kills the cancer cells and the support cells that the cancer uses to grow and shield itself.

By targeting the support cells, the treatment also releases toxins that can kill neighboring cancer cells. Additionally, destroying the support cells weakens the tumor structure, making it easier for the body's immune system to attack and eliminate it.

The ADC consists of three main components: an antibody, a chemical linker that ties the antibody to the drug, and a strong chemotherapeutic drug. Once the ADC has located and entered the cancer cell, the linker decomposes, activating the chemotherapy and killing the cancer cell from the inside. This Trojan horse strategy offers targeted treatment without affecting the healthy cells.

Because ADC treatment is extremely accurate and causes minimal damage to healthy cells, it is a likely candidate for treatment of the more difficult cancers.

As part of the process, the researchers have humanized the ADC antibody, which means that we have changed its structure to resemble antibodies naturally occurring in the human body. This adjustment ensures that the body's immune system does not recognize the antibody as foreign and attack it. Humanization is a critical step in making the treatment both safe and effective for patients and represents a key milestone on the path towards clinical trials.

The researchers are now working to further develop the drug and get it ready for clinical testing on humans with pancreatic cancer.

Virginia Metrangolo et al, Targeting uPAR with an antibody-drug conjugate suppresses tumor growth and reshapes the immune landscape in pancreatic cancer models, Science Advances (2025). DOI: 10.1126/sciadv.adq0513

• ‹ Previous
• 1
• …
• 48
• 49
• 50
• 51
• 52
• …
• 1053
• Next ›
• Page