Vitamin B₁, also known as thiamine, is crucial for our health.
It helps keep our cells functioning, but our bodies can’t make it on their own. Instead, we need to get it from foods like salmon, legumes, and brown rice.
Without enough Vitamin B₁, we could face serious health issues, including problems with our heart and nervous system, which could lead to disability or even death.
Sometimes, even when our blood shows normal levels of Vitamin B₁, it might not be reaching important organs like the brain.
This can happen as a side effect of some medications, making it difficult to detect until it’s too late.
To better understand this hidden problem, scientists from EMBL Hamburg and the VIB-VUB Center for Structural Biology studied how Vitamin B₁ moves through the body.
Their research, published in Nature Communications, focused on how Vitamin B₁ passes through various barriers to reach tissues and organs, especially the brain.
These barriers, like the gut wall and blood-brain barrier, prevent harmful substances from entering but also make it harder for essential nutrients, like Vitamin B₁, to get through.
Special molecules called transporters help Vitamin B₁ cross these barriers. Two key transporters for Vitamin B₁ are SLC19A2 and SLC19A3. The research focused on SLC19A3, which is responsible for helping Vitamin B₁ pass through the gut and into the brain.
To see how the SLC19A3 transporter works, scientists used a technique called cryo-electron microscopy (cryo-EM) to create a detailed “molecular movie” showing how the transporter recognizes and moves Vitamin B₁ across cell membranes.
This discovery helps explain how certain mutations can prevent Vitamin B₁ from reaching the brain, causing severe neurological problems.
These findings are important because some rare diseases caused by transporter mutations can result in serious brain conditions. While these diseases can be treated with high doses of Vitamin B₁, some patients still experience symptoms, and the condition can be fatal for others.
The researchers also discovered that certain medications, such as antidepressants, antibiotics, and cancer drugs, can block the SLC19A3 transporter.
This can lead to hidden Vitamin B₁ deficiencies in specific organs, particularly the brain, even when blood levels appear normal. These deficiencies can quietly cause serious health issues, including brain dysfunction.
The study’s findings may help doctors monitor patients taking these medications more closely and guide the development of new drugs that avoid these side effects.
By better understanding how these transporters work, future drugs might be designed to reach target organs more effectively, helping protect patients from hidden deficiencies.
