Medical Bulletin 11/October/2025

To explore the gene’s function, Professor Miriam Cnop’s team at ULB used stem cells that were differentiated into pancreatic beta cells, those responsible for producing insulin. Using CRISPR gene-editing technology, they demonstrated that when TMEM167A is altered, the beta cells activate stress pathways and eventually die, rendering them unable to produce insulin.

Professor Cnop added, “The ability to generate insulin-producing cells from stem cells has enabled us to study what is dysfunctional in the beta cells of patients with rare forms as well as other types of diabetes. This is an extraordinary model for studying disease mechanisms and testing treatments.”

The research confirms that TMEM167A is critical not only for pancreatic function but also for neurons. The discovery opens new avenues for understanding insulin production and could offer valuable insights into broader diabetes research, a condition affecting nearly 589 million people globally.

Reference: Enrico Virgilio et al, Recessive TMEM167A variants cause neonatal diabetes, microcephaly and epilepsy syndrome, Journal of Clinical Investigation (2025). DOI: 10.1172/jci195756

How PM2.5 Pollutants Reprogram Brown Fat and Raise Diabetes Risk? Study Finds

A new study published in JCI Insights has revealed that long-term exposure to fine air pollution may significantly impair metabolic health, providing fresh insights into how pollutants can trigger insulin resistance and increase the risk of type 2 diabetes. The study highlights how particulate matter known as PM2.5 can disrupt the function of x tissue through complex epigenetic changes.

Researchers exposed laboratory mice to either filtered air or concentrated PM2.5 particles, tiny pollutants less than 2.5 micrometers in diameter for six hours a day, five days a week, over a 24-week period. This experiment was designed to simulate chronic urban pollution exposure in humans. The team focused on brown fat, a specialized form of adipose tissue critical for regulating body heat and glucose metabolism.

After nearly five months, mice exposed to PM2.5 showed clear signs of metabolic dysfunction, including insulin resistance and altered brown fat activity. “In particular, we found that the expression of important genes in brown adipose tissue which regulate its ability to produce heat, process lipids and handle oxidative stress were disturbed,” said Francesco Paneni, professor at the Center for Translational and Experimental Cardiology of the University of Zurich. The affected mice also exhibited increased fat accumulation, tissue damage, and early signs of fibrosis.

To understand the underlying biological mechanisms, the scientists examined changes in gene regulation within brown fat cells. They discovered that air pollution caused significant epigenetic modifications—particularly in DNA methylation and chromatin structure. Two key enzymes, HDAC9 and KDM2B, were found to be responsible for these changes by modifying histone proteins, which affected how genes were activated or silenced.

The findings present new evidence that air pollution can be a driver of metabolic disease by altering gene function in fat cells.

Reference: Palanivel R, Dazard JE, Park B, Costantino S, Moorthy ST, Vergara-Martel A, Cara EA, Edwards-Glenn J, Biswal S, Chen LC, Jain MK. Air pollution modulates brown adipose tissue function through epigenetic regulation by HDAC9 and KDM2B. JCI Insight. 2025 Sep 23;10(18).

Genome Sequencing in Newborns May Identify Life-Threatening Disorders Missed by Traditional Tests

A recent study published in Nature Medicine has revealed that adding genomic sequencing to Australia’s standard newborn blood screening could dramatically improve early diagnosis and treatment for hundreds of severe childhood conditions.

The BabyScreen+ study demonstrated that using genomic sequencing which maps a baby’s entire genetic code, could expand screening to detect hundreds of serious, treatable disorders. The test, using the same blood sample already collected for standard screening, returned results within 14 days.

In the pilot study, 1,000 newborns in Victoria were screened for changes in 605 genes linked to early-onset, severe, and treatable conditions. The genomic testing, conducted separately from the standard screening, required additional parental consent. Researchers found that 16 babies had a high likelihood of a genetic condition, yet only one was identified through the traditional heel-prick test.

One powerful case was that of baby Giselle, diagnosed at seven weeks with the life-threatening immune disorder hemophagocytic lymphohistiocytosis (HLH). “We went from thinking we had a healthy baby to the real possibility she might die,” said her mother, Scarlett. A successful bone marrow transplant, with Scarlett as the donor, saved Giselle’s life.

Lead researcher Professor Zornitza Stark said, “Newborn screening for rare conditions is one of the most effective public health interventions,” emphasizing how genomic screening vastly expands the range of detectable diseases. Associate Professor Sebastian Lunke added that while the technology offers lifelong benefits, it raises concerns around privacy, cost, data storage, and consent.

With 99.5% of parents in the study supporting universal access to the testing, the study's findings pave the way for broader adoption.

Reference: Lunke, S., Downie, L., Caruana, J. et al. Feasibility, acceptability and clinical outcomes of the BabyScreen+ genomic newborn screening study. Nat Med (2025). https://doi.org/10.1038/s41591-025-03986-z