Thursday, November 22, 2012

Rejuvenating Aged Human Cells w/ Cytokine Growth Factors

A recent collaboration between researchers in Toronto and researchers in Harbin, China, has uncovered the ability to rejuvenate adult mesenchymal stem cells to be used on scaffolds as a healthy replacement for damaged heart tissue -- in heart failure and after massive myocardial infarction.
In the present study, the researchers report a new method to repair damaged hearts that could occur from heart attacks.

Specifically they studied the ability to rejuvenate adult bone marrow cells and embed them into a biodegradable patch which could then be implanted into damaged hearts.

To perform the study, the researchers first created a biodegradable collagen scaffold upon which they coated two growth factors known to promote cell growth, VEGF and bFGF.

Next they seeded human mesenchymal stromal cells from the bone marrow of middle aged (50) and old aged (75 ) donors onto the scaffold.

The scaffolds were then grown in culture and examined for cell growth and function in rats with damaged hearts. They grew patches both with and without the growth factors.

They found that old cells didn’t grow as well into the patches than young cells and the patches were not as effective when implanted in rats.

However adding the rejuvenative cytokines caused the old cells to rejuvenate. After treatment these cells grew in better and the patches performed better.

The researchers determined that the old cells had a different RNA pattern after exposure to the growth agent. In particular a gene called p16 which is expressed in all aged senescent cells was markedly reduced.
This new ability to transform the gene expression of old stem cells to more closely match the gene expression of young stem cells, offers a general promise of rejuvenation to all aging cells -- once scientists discover safer ways of inducing such revitalising transformations.

Restoration of cardiac function was possible with a cytokine-enhanced, tissue-engineered patch that rejuvenated aged cells. Covalent immobilization of 2 proangiogenic cytokines, VEGF and bFGF, onto a collagen scaffold enhanced cell proliferation in vitro and prolonged cell survival and improved angiogenesis to restore ventricular morphology and function in vivo. Of note, the improvement was most obvious with patches seeded with cells from old donors. This novel cytokine-conjugated, sustained-release system provides a practical and promising platform for cardiac repair in elderly survivors of an extensive MI, an important advance in an increasingly aging society _Jn. Am. Coll. Cardiology (PDF) via

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