Preclinical study defines spleen-heart connection in heart repair
Update: 24 Aug 2021 08:27 STI
Washington [US], Aug 24 (ANI): A preclinical study conducted by researchers at the University of South Florida (USF Health) analyzed the interactions of the lipid mediator sphingosine-1-phosphate (S1P) in the spleen and heart during the transition from acute phase to acute phase. Chronic heart failure.
The study was published in the American Journal of Physiology-Heart and Circulation.
Although we may survive without a spleen, evidence continues to mount that this abdominal organ plays a more valuable role in our physiological defenses than previously thought.
Using a mouse model of heart failure, researchers discovered new mechanisms to help define how the spleen and heart coordinate physiological inflammation in cardiac repair.
“The spleen contains a whole army of immune cells and signaling molecules that can be quickly mobilized to respond whenever a major injury like a heart attack or viral invasion occurs,” said Ganesh Halade, PhD, professor. associate of cardiovascular sciences at the University of Health of South Florida (USF Health) Morsani College of Medicine.
Dr Halade led a new preclinical study that analyzed the interactions of the lipid mediator sphingosine-1-phosphate (S1P) in the spleen and heart during the transition from acute heart failure to chronic heart failure. Researchers have discovered new heart repair mechanisms to help shed light on the spleen-heart coordination of physiological inflammation in a mouse model of heart failure.
“Simply put, we have shown that the spleen and heart work together via S1P for cardiac repair,” said lead researcher Dr. Halade, a member of the USF Health Heart Institute. “Our study also suggests that early detection of low or zero levels of S1P after a heart attack and targeted activation of this bioactive lipid mediator may provide cardioprotective therapy for patients at high risk for heart failure.”
Dr Halade and his colleagues have defined links between fatty acids, dysfunctional control of inflammation and heart failure. His lab is focused on finding ways to prevent, delay, or treat unresolved inflammation after a heart attack. In this latest study, the researchers turned their attention to where S1P is produced and its role in cardiac repair.
S1P is a deregulated lipid mediator during inflammatory responses, including heart failure. In addition, several groups have demonstrated the potential importance of this signaling molecule as a therapeutic target for heart failure triggered by heart attack and ischemia-reperfusion injury.
The USF Health study captured the time-dependent movement of S1P from the spleen through blood plasma flowing to the heart. The work was the first to quantify the interactions between S1P and the S1P 1 receptor (S1PR1) during the progression of acute to chronic heart failure, said Dr Halade.
The researchers defined S1P / S1PR1 signaling in mice and humans with heart failure after a heart attack. The otherwise young and healthy “safe” mice did not exhibit any variable cardiovascular risk factors such as obesity, diabetes, hypertension, and aging commonly seen in clinical settings. The researchers correlated the physiological data from the experiments on the mouse model of cardiac repair with what they observed in pathologically failing human hearts.
Among their main conclusions:
1. Heart-specific S1P and S1PR1 levels were reduced in patients with ischemic heart failure.
2. In safe mice, physiological cardiac repair was facilitated by activation of S1P in the heart and spleen. S1P / S1PR1 signaling increased in both organs from acute heart failure to chronic heart failure, helping to promote heart repair after a heart attack.
3. An increase in plasma S1P indicates cardiac repair in the acute phase of heart failure.
4. Selective activation of the S1P receptor in macrophages (immune cells that help clear inflammation and guide tissue repair) suppressed inflammation biomarkers and accelerated cardiac healing biomarkers in cardiac cells. mouse.
“This study provides another example that the spleen should not be underestimated, as it contributes to the foundation of our immune health as well as the root cause of inflammatory diseases, including cardiovascular disease,” said Dr Halade. .
The research was funded by grants from the National Institutes of Health and the US Department of Veterans Affairs. The USF Health team worked with collaborators from the University of Alabama in Birmingham and the University of Hokkaido, Japan. (ANI)