Susana Gonzalo, Ph.D., published a paper in Cell Reports detailing her lab’s studies on Hutchinson-Gilford Progeria Syndrome (HGPS), which is caused by a single mutation in the LMNA gene that encodes the lamin A protein. Children with HGPS age rapidly and show changes typical to older age, such as hair loss, joint pains, and aging of skin, as well as an increased risk of atherosclerosis.
The mutated, shortened form of lamin A produced by the mutated gene is called progerin. The Gonzalo lab found that progerin accumulates in the nucleus of cells, leading to replication stress and stalling, as well as preventing protection of newly replicated DNA. They also found that degraded DNA that has leaked outside of the cell can cause inflammatory responses through an interferon pathway.
Their studies also uncovered a way to improve cell fitness, by treatment with vitamin D and other compounds that reduce replication stress and inflammatory response. They saw a marked reduction in toxicity from progerin after these treatments, which could lead to new therapies for HGPS.
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An IFN-like response in HGPS fbroblasts is repressed by calcitriol.
Untreated NFs and HGPS cells treated with calcitriol or vehicle for 4 days were subjected to subcellular fractionation to monitor localization of P-STAT1Y701 and IRFs. Note the nuclear accumulation of P-STAT1 and IRF3 in HGPS cells and how calcitriol reduces their nuclear levels (red square).