New Research Helps To Regenerate Heart Tissue After A Heart Attack

This research advances the possibility of reviving the heart’s regenerative capacities using microRNAs. 

Heart Attack
Heart Attack

Research publish in the journal Nature Communications, shows that delivering two microRNAs to mice helps their hearts regenerate after a heart attack.

United States-Heart disease is the leading cause of death and responsible for almost 1 in 4 deaths in the nation.

An adverse cardiovascular occasion, such as a heart attack, typically damages the cells that make up the heart muscle.

These cells are called cardiomyocytes, and losing them puts individuals at risk of heart failure — a condition wherein the heart cannot pump blood viably to the rest of the body.

The scientific consensus is that adult hearts can never again create new cardiomyocytes. This inability is the reason the heart cannot regenerate itself after a heart attack when gigantic numbers of cardiomyocytes are lost.

New research, nonetheless, renews any expectation of protecting damaged heart tissue by using small molecules called microRNAs.

Why microRNAs are important for the heart?

MicroRNAs control gene function and they can be found in abundance when the heart is developing.

Past research has identified a cluster of microRNAs called miR-17-92 that controls how cardiomyocytes proliferate. Ph.D., a cardiology researcher at Boston Children’s Hospital and a professor of pediatrics at Harvard Medical School in Boston, MA, led this previous research, Da-Zhi Wang.

Presently, Prof. Da-Zhi Wang and his colleagues have zoomed in on two members of this microRNA family: miR-19a and miR-19b.

In the new study, Professor Da-Zhi Wang and his colleagues show how these two microRNA molecules can drive heart regeneration after myocardial infarction.

Heart Attack
Heart Attack

The research could help forestall heart failure following a heart attack, which is, according to the researchers, “the leading cause of mortality and morbidity in humans.”

The short-and long haul impact of microRNAs

Prof. Da-Zhi Wang and his team used a mouse model of a heart attack and delivered the microRNAs in two different ways.

Firstly, they administered the lipid-coated molecules directly to the mice. Secondly, the researchers placed the microRNAs in an adeno-associated virus — that is, a gene therapy vector that targeted the heart.

With both delivery methods, the results were promising, both in the long haul and in the short term.

Namely, in the first 10 days after a heart attack, the microRNAs reduced cell death and stopped the inflammatory reaction that typically damages the heart muscle during a heart attack.

The researchers also carried out a genome-wide transcriptome analysis that revealed how miR-19a/19b repressed the genes that controlled the inflammatory response and acute cell death.

After some time, the hearts of the mice that received the molecules had progressively healthy tissue, less damaged tissue, better heart muscle contractility, and reduced dilated cardiomyopathy — a condition in which the heart muscle thins, which, ultimately, weakens the heart.

“The initial purpose is to rescue and shield the heart from long haul damage,” explains Professor Da-Zhi Wang “In the second phase, we trust microRNAs help with cardiomyocyte proliferation.”

The advantages of microRNA therapy

The researchers proceed to explain the benefits of microRNA therapy. In contrast to gene therapy, they say, the microRNA molecules do not stay in the heart after they have fulfilled their purpose.

“They go in exceptionally fast and do not last long, however they have a lasting impact in repairing damaged hearts,” explains one of the corresponding authors of the study, Dr.Jinghai Chenadds

“We gave mice just a single shot when the heart needed the most help, at that point we continued checking expression level of miRNA19a or miRNA19b post-injection,” Dr.Jinghai Chenadds said. “After one week, expression decreased to a normal level, however the security lasted for over one year.”

“MicroRNAs hold tremendous promise to turn out to be incredible assets to battle cardiovascular disease,” compose the researchers, who are next planning to test the treatment in a larger mammal before moving on to human studies. Prof. Da-Zhi Wang and colleagues conclude:

“MiR-19a/19b-mediated early cardiac assurance could open a window to the development of successful therapy for heart attack and bring great benefits to heart failure patients.”

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