APR 25, 2018 5:22 AM PDT

Cardiac Development Depends on the "Hippo" Pathway

WRITTEN BY: Kara Marker

The same molecular pathway that is responsible for preventing adult heart cells from regenerating after being damaged - like after a heart attack - has been identified as involved in embryonic development of the mouse heart. Researchers from the Baylor College of Medicine anticipate learning more about this phenomenon could someday improve the treatment of heart disease.

An opened oviduct with an ectopic pregnancy features a 10-millimeter embryo. Credit: Ed Uthman, MD.

In the new study, researchers focused on a population of cells called epicardial cells. They are a type of cardiac progenitor cells, which are virtually halfway between a stem cell and a differentiated cell. Epicardial cells support heart muscle cells, called cardiomyocytes, both during initial development and later during injury, like a heart attack. Researchers wanted to know how the Hippo pathway is involved in the differentiation of epicardial cells.

To find out, researchers created mice genetically altered to be deficient in key parts of the Hippo pathway. How do hearts of these mice develop differently from normal mice? Researchers also analyzed blood vessel structure and more than 18,000 cells isolated from heart tissue in the middle of development.

"This technology allowed us to determine the status of thousands of cells individually,” explained corresponding author Dr. James Martin. “For instance, we learned what genes were turned on and what molecules the cells were expressing. This high level of detail shed light into the cellular and molecular processes leading to an adult heart and how they are coordinated."

Researchers observed that the hearts of genetically Hippo-deficient were smaller than hearts from genetically normal mice. Additionally, blood vessels failed to develop correctly in the genetically altered mice.

They were also able to link specific genes and other molecular pathways surprisingly linked to the Hippo pathway during embryonic development of the mouse heart.

"We found cells suspended in intermediate states and producing factors important for regulating growth and proliferation of vascular endothelial cells," Martin explained. "That was all unexpected."

"We know that the Hippo pathway is involved in regeneration of the adult heart, but also controls the size of the developing heart," Martin concluded. "As the heart grows, more vascular cells need to move into the heart to provide blood vessels to sustain its growth and later support the function of the adult heart. We think that the Hippo pathway can sense the size of the growing heart and, by regulating a number of secreted factors, determine how many cardiac fibroblasts and endothelial cells develop in the heart.”

In the future, Martin and his team will investigate how they can improve blood vessels’ ability to regenerate in the adult heart to improve the treatment of heart disease.

The present study was published in the journal Developmental Cell.

Sources: Cell Signaling Technology, Baylor College of Medicine

About the Author
I am a scientific journalist and enthusiast, especially in the realm of biomedicine. I am passionate about conveying the truth in scientific phenomena and subsequently improving health and public awareness. Sometimes scientific research needs a translator to effectively communicate the scientific jargon present in significant findings. I plan to be that translating communicator, and I hope to decrease the spread of misrepresented scientific phenomena! Check out my science blog: ScienceKara.com.
You May Also Like
MAR 08, 2022
Cardiology
Poor Sleep May Nearly Triple Heart Disease Risk
MAR 08, 2022
Poor Sleep May Nearly Triple Heart Disease Risk
Poor sleep has many negative consequences, including a serious impact on heart health.
MAR 31, 2022
Cancer
New Study Finds No Link between Childhood Obesity and Thyroid Cancer
MAR 31, 2022
New Study Finds No Link between Childhood Obesity and Thyroid Cancer
The incidence of thyroid cancer among children has been increasing over recent decades. Similarly, cases of childhood ob ...
MAY 22, 2022
Drug Discovery & Development
Gout Medication Helps Hospitalized People with Heart Failure
MAY 22, 2022
Gout Medication Helps Hospitalized People with Heart Failure
A research team at the University of Virginia Hospital System found that a regularly-used medication for gout, called co ...
JUN 07, 2022
Cardiology
Overtraining Negatively Impacts Mood and Heart Rate Variability
JUN 07, 2022
Overtraining Negatively Impacts Mood and Heart Rate Variability
Athletes tend to have a worse mood and lower heart rate variability the day after intense training.
JUN 12, 2022
Neuroscience
Multiple Heart-Related Conditions Triples Dementia Risk
JUN 12, 2022
Multiple Heart-Related Conditions Triples Dementia Risk
People who have multiple cardiometabolic conditions have a three times higher dementia risk than those with a high genet ...
AUG 06, 2022
Technology
Wearable Devices More Cost Effective Way to Screen for Atrial Fibrillation
AUG 06, 2022
Wearable Devices More Cost Effective Way to Screen for Atrial Fibrillation
Atrial fibrillation (AF), a condition characterized by abnormal, fast heart beats, affects an estimated five million peo ...
Loading Comments...