Herstel van het hart

Nieuws | de redactie

14 juni 2011 | Britse wetenschappers hebben een doorbraak bereikt in het onderzoek naar hartfalen. Een team rond Paul Riley van het University College London Institute of Health voerde tests uit met het injecteren van muizen met een proteine cocktail. Dat leidde ertoe dat verschilende cellen zich konden omzetten in hartspiercellen en daarmee de schade van infacten konden helpen repareren.

A group of British researchers successfully tested a cure to heart damage. With these insights, clinicaltests with humans are set to start with the goal to develop a pillor injection that can heal so far incurable heart damage. Togetherwith his team, Paul Riley injected mice every day for a week with aprotein called thymosin ß4 (Tß4). Subsequently, they caused themice artificial heart strokes that resulted in permanent damage totheir heart muscle cells (cardiomyocytes).

After two days, the scientists observed that so called heartprogenitor cells started turning themselves into cardiomyocytesamassing around the heart’s outer layer. Within two weeks, thesenew cells moved to the inner layers and substituted those cellsthat were irreparably damaged through the earlier stroke. Thechoice for Tß4 fell as this protein was part of earlier studies.These studies showed that Tß4 activates heart progenitor cells withthe ability to turn them into blood vessels.

Epigenetic Effect?

How exactly Tß4 triggered these cells to transform is notcompletely clear. Much points towards the interaction between Tß4and a gene from the progenitor cell. “We studied the activity of agene called Wt1, because we know that embryonic stem cellsexpressing Wt1 can become cardiomyocytes, but Wt1 is switched offin adults,” states Riley. The protein Tß4 would then chemicallychange the DNA of the cell and activate the sequencing of thisgenetic information, which is referred to as an epigeneticeffect.

Maurice van den Hoff, cardiac biologist at the Heart FailureResearch Center Amsterdam, commented on the study saying earlierattempts to regenerate cardiomyocytes involved lipid or bone-marrowstem cells. These stem cells, however, did not turn into perfectheart cell substitutes and could therefore offer no long-term curefor patients.

The approach from Riley’s team, by contrast, appeared moresuccessful and will now be followed up by clinical trials. Alas,until it is possible to take pills to recover from a stroke, muchtime will pass. New pharmaceuticals usually take between 10 and 15years to be approved.