Progerin, a mutant protein associated with both premature and normal ageing, acts by interfering with human mesenchymal stem cells (hMSCs). A study published online in Nature Cell Biology provides a mechanism by which this protein contributes to the premature ageing disease Hutchinson-Gilford Progeria Syndrome (HGPS), and implications for our understanding of normal ageing.
Progerin, an abnormal form of the nuclear protein lamin A, is the causal agent of HGPS. However, progerin is also produced in normal individuals, and its presence in healthy cells has been linked to normal ageing.
Paola Scaffidi and colleagues have found that high levels of progerin alter the identity of the stem cells, resulting in abnormal osteogenesis and adipogenesis, consistent with the defects seen in the HGPS disease. They also see that proteins in the Notch signalling pathway -- known to be important for stem cell differentiation -- are more active when progerin is present; blocking the Notch pathway can partly rescue the problems in the stem cells' fate. The Notch pathway also seems to be affected in HSPS patient cells.
While providing a possible mechanism by which progerin contributes to the HGPS disease, these findings also have implications for our understanding of normal ageing and suggest that progerin effects on Notch signalling might similarly affect healthy hMSCs, and reduce potential for tissue homeostasis during ageing.
Paola Scaffidi (National Cancer Institute, NIH, Bethesda, Maryland, USA)
Abstract available online.
(C) Nature Cell Biology press release.
Message posted by: Trevor M. D'Souza