Roles of Mesp1 gene

Researchers at the Université libre de Bruxelles and University of Cambridge identified the role of key gene Mesp1 in the earliest step of cardiovascular lineage segregation. This discovery may help to better understand congenital heart defects. The heart is the first organ that forms during development and contains four regions (ventricles and atria), which contain cells that perform specialized functions: the beating cardiomyocytes ensure the pumping activity, vascular cells represent the inner lining and blood vessels, and the pacemaker cells regulate the heartbeat.

Unless the progenitor cells are specified at the correct time, migrate to the correct location, and differentiate into the correct cell types, severe malformations of the heart occur. In human patients, these are recognized as congenital heart diseases, which represent the most common cause of severe birth defects in newborn babies. Previous studies had shown that a diverse range of heart progenitor cells arises from different pools of cells expressing the Mesp1 gene. However, it remained unclear how the various progenitors can be distinguished at the molecular level, and what molecular mechanisms promote specification into a particular heart region or cardiac lineage.

Researchers led by Pr. Cédric Blanpain, Laboratory of Stem Cells and Cancer, Université libre de Bruxelles, Belgium, and Pr. Berthold Göttgens, the University of Cambridge, identified the role of Mesp1 in the earliest step of cardiovascular lineage segregation by single cell molecular profiling and lineage tracking. Fabienne Lescroart and colleagues isolated Mesp1 expressing cells at different stages of embryonic development and performed single cell transcriptomic analysis of these early cardiac progenitors to identify the molecular features associated with regional and cell type identity of cardiac progenitors.

They demonstrated that the different populations of cardiac progenitors are molecularly distinct. To determine the role of the transcription factor Mesp1 in regulating the cardiovascular differentiation program and the heterogeneity of early cardiovascular progenitors, they also performed single cell molecular profiling of these early progenitors in a Mesp1 deficient context. These experiments showed that Mesp1 is required for the exit from the pluripotent state and the induction of the cardiovascular gene expression program.

Bioinformatic analysis identified, among these early Mesp1 progenitors, distinct populations of cells corresponding to progenitors committed to different cell lineages and regions of the heart, identifying the molecular features associated with early lineage restriction and regional segregation of the heart. While progenitor cells are not yet differentiated, this new analysis shows that cardiovascular progenitors are already "primed" or pre-specified to give rise to cardiac muscle cells or vascular cells. The researchers found that these different populations are also born at different time points and are located at specific locations at this early stage of development.

The researchers have identified the earliest branching point between the cardiac and vascular lineages, and shown that Notch1 marks the early progenitor committed to the vascular lineage during early embryonic development. Understanding the molecular features associated with early cardiovascular lineage commitment and heart regions will be important to design new strategies to instruct cardiovascular progenitors to adopt cardiac or vascular identity from different heart regions that can be used for cellular therapy of cardiac diseases.
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Aspiring not effective for stroke prevention in atrial fibrillation patients

Atrial fibrillation (A-fib) is a condition of irregular heartbeat, it can leads to cardiovascular events like: stroke, blood clots and heart failure.

The most common treatment for A-fib patients is prescribing anticoagulants, or blood thinners. Some people with A-fib may also have a catheter ablation - a medical procedure that uses energy to damage a small part of heart tissue, thus stopping abnormal electrical signals from traveling through the heart.

Some of the risks associated with cardiac catheter ablation include bleeding or blood vessel damage.

However, as Dr. Jared Bunch - the lead author of the new research - explains, when patients with A-fib have had an ablation and also have a low risk of stroke, physicians prefer to treat them with aspirin instead of blood thinners in order to further reduce the risk of stroke.

In the new study, Dr. Bunch and his colleagues examined the effect of long-term aspirin use on patients with A-fib who underwent an ablation.

Putting their new research into perspective, Dr. Bunch explains, "What was unknown was if aspirin was a safe and effective stroke prevention treatment after an ablation in lower-risk AF [atrial fibrillation] patients.

Aspirin has no benefit for stroke prevention in patients with A- fib. The study examined 4,124 patients with A-fib over a period of 3 years. The participants had a low risk of stroke, and they had undergone catheter ablation.

Dr Bunch and colleagues discovered that patients that used aspiring were significantly more likely to have gastrointestinal and genitourinary bleeding than those who took anticoagulants such as warfarin, or compared with those who did not receive any treatment.

Huge women at risk of Atrial fibrillation

Atrial fibrillation is an irregular heartbeat that can lead to blood clots, stroke and heart failure.

Annika Rosengren, professor of internal medicine at Sahlegrenska Academy investigated the effects of body size on atrial fibrillation risk in women.

The study examined 1,522,358 women who had their first pregnancy at an average age of 28 years. Clinical data on height, age, pregnancy, history of diabetes, high blood pressure and smoking were considered during the study.

During follow-up, 7,000 women were hospitalized with atrial fibrillation, their average age was 49, the researchers calculated the women's body surface area BSA in square meters.

The women were divided into four groups based on their BSA and discovered that bigger women, older women and those with bigger atrium are at risk of atrial fibrillation.

Potassium as good as sodium for healthy blood pressure

Potassium is a mineral that is needed for human body to function properly, it helps muscles to contract and promotes regular heartbeat.

Diet rich in potassium regulates harmful effects of too much salt in the body, excess consumption of sodium can cause hypertension, eating foods rich in potassium can reduce the blood pressure to normal. Foods rich in potassium are: Carrot, Banana, Sweet potato, Dark leafy greens,  Fish, and Avocado.

According to Dr Alicia McDonough of University of California, eating foods high in potassium is equivalent to taking a substance that increases production of urine and reduce sodium in the body.

High intake of potassium leads to excretion of more salt and water and decreases potassium excretion, this will put the blood pressure under control.

Researchers established the link between diet and blood pressure after accessing rodents and discovered that the body does a balancing act to control potassium in the body by using sodium.