Endothelial cell-specific progerin expression does not cause cardiovascular alterations and premature death

Area of Science:

• Genetics
• Molecular Biology
• Cardiovascular Research

Background:

• Hutchinson-Gilford progeria syndrome (HGPS) is a rare genetic disorder linked to the LMNA gene mutation, leading to progerin production and accelerated aging.
• Cardiovascular anomalies, including vascular smooth muscle cell loss, fibrosis, and atherosclerosis, are key features of HGPS.
• The role of progerin specifically in endothelial cells (ECs) regarding HGPS cardiovascular manifestations remains unclear.

Purpose of the Study:

• To investigate whether progerin expression in endothelial cells is sufficient to induce the cardiovascular pathology observed in Hutchinson-Gilford progeria syndrome.
• To determine the impact of EC-specific progerin expression on vascular structure, cardiac function, and overall lifespan in both atherosclerosis-free and atheroprone mouse models.

Main Methods:

• Generated EC-specific progerin-expressing mouse models: atherosclerosis-free (Lmna^LCS/LCSCdh5-CreERT2) and atheroprone (Apoe^-/-Lmna^LCS/LCSCdh5-CreERT2).
• Compared these models to respective progerin-free controls, assessing cardiac fibrosis, electrical/functional alterations, vascular integrity, atherosclerosis, body weight, and lifespan.

Main Results:

• Mice with EC-specific progerin expression (Lmna^LCS/LCSCdh5-CreERT2) showed no cardiac fibrosis, electrical/functional issues, vascular abnormalities, or changes in lifespan compared to controls.
• Atheroprone mice with EC-specific progerin expression (Apoe^-/-Lmna^LCS/LCSCdh5-CreERT2) did not exhibit aggravated atherosclerosis, vascular alterations, or altered lifespan compared to controls.

Conclusions:

• Progerin expression within endothelial cells is not sufficient to cause the premature aging, cardiovascular dysfunction, or mortality characteristic of Hutchinson-Gilford progeria syndrome.
• These findings suggest that other cell types or mechanisms are primarily responsible for the severe cardiovascular pathology in HGPS.