Cardiovascular Progerin Suppression and Lamin A Restoration Rescue Hutchinson-Gilford Progeria Syndrome

Abstract

Background: Hutchinson-Gilford progeria syndrome (HGPS) is a rare disorder characterized by premature aging and death mainly due to myocardial infarction, stroke, or heart failure. The disease is provoked by progerin, a variant of lamin A expressed in most differentiated cells. Patients look healthy at birth, and symptoms typically emerge in the first or second year of life. Assessing the reversibility of progerin-induced damage and the relative contribution of specific cell types is critical to determining the potential benefits of late treatment and to developing new therapies. Methods: We used CRISPR/Cas9 technology to generate Lmna HGPSrev/HGPSrev (HGPSrev) mice engineered to ubiquitously express progerin while lacking lamin A and allowing progerin suppression and lamin A restoration in a time- and cell-type-specific manner upon Cre recombinase activation. We characterized the phenotype of HGPSrev mice and crossed them with Cre transgenic lines to assess the effects of suppressing progerin and restoring lamin A ubiquitously at different disease stages as well as specifically in vascular smooth muscle cells (VSMCs) and cardiomyocytes. Results: Like HGPS patients, HGPSrev mice appear healthy at birth and progressively develop HGPS symptoms, including failure to thrive, lipodystrophy, VSMC loss, vascular fibrosis, electrocardiographic anomalies, and precocious death (median lifespan of 15 months versus 26 months in wild-type controls, p<0.0001). Ubiquitous progerin suppression and lamin A restoration significantly extended lifespan when induced in 6-month-old mildly symptomatic mice and even in severely ill animals aged 13 months, although the benefit was much more pronounced upon early intervention (84.5% lifespan extension in mildly symptomatic mice, p<0.0001, and 6.7% in severely ill mice, p<0.01). Remarkably, major vascular alterations were prevented and lifespan normalized in HGPSrev mice when progerin suppression and lamin A restoration were restricted to VSMCs and cardiomyocytes. Conclusions: HGPSrev mice constitute a new experimental model for advancing knowledge of HGPS. Our findings suggest that it is never too late to treat HGPS, although benefit is much more pronounced when progerin is targeted in mice with mild symptoms. Despite the broad expression pattern of progerin and its deleterious effects in many organs, restricting its suppression to VSMCs and cardiomyocytes is sufficient to prevent vascular disease and normalize lifespan.

Progerin triggers a phenotypic switch in vascular smooth muscle cells that causes replication stress and an aging-associated secretory signature

“…Interestingly, there is also a robust loss of VSMC in the medial layer, visualized by a decrease in the number of nuclei in the Hematoxylin-Eosin (H&E) staining (Figure 4C). This massive loss of VSMC in progeria mice has been reported by other investigators (Del Campo et al, 2019; Hamczyk et al, 2018; Sánchez-López et al, 2021). We find that in Lmna G609G/G609G mice fed a HFD, which live longer, the loss of VSMC, the thickening of the adventitia, and the overall increased fibrosis in the aorta is more dramatic than in progeria mice on a regular diet.…”

“…Vascular abnormalities in HGPS include atherosclerosis and Vascular Smooth Muscle Cells (VSMC) loss in the aortic media, suggesting a causal connection between VSMC loss and cardiovascular malfunction (Hamczyk et al, 2018; Nevado et al, 2020) Interestingly, the severity of atherosclerosis and VSMC loss correlates with a concomitant increase of Extracellular Matrix (ECM) deposition, leading to vessel stiffening and CVD (Hamczyk et al, 2018). A recent publication demonstrated with a genetic approach, that restoring lamin A ubiquitously in VSMC, ameliorates CVD, indicating that the progerin-induced alteration of VSMC biology is a key contributor to vascular disease in HGPS (Sánchez-López et al, 2021). Moreover, different pharmacological strategies have proved successful in reducing VSMC loss in HGPS mice and improving vascular disease.…”

Cellular Biomechanic Impairment in Cardiomyocytes Carrying the Progeria Mutation: An Atomic Force Microscopy Investigation

“…In a recent gene-edited mice model of HGPS (HGPSrev), the mice appeared healthy at birth and, like humans, progressively developed HGPS symptoms, including vascular smooth muscle cell loss, vascular fibrosis, electrocardiographic anomalies, and precocious death. Remarkably, progerin suppression and lamin A restoration significantly improved the phenotype and increased the lifespan of this HGPS mice model . Although an altered cardiomyocyte structure has been described in laminopathies, − they are less understood in progeria.…”

Quantification of Farnesylated Progerin in Hutchinson-Gilford Progeria Patient Cells by Mass Spectrometry

“…Until very recently, direct MS-based analysis of endogenous prenylation has been confined to the simple mass measurement by matrix-assisted laser desorption/ionization (MALDI)-MS of farnesylated peptides from progerin [ 25 ] and guanine nucleotide-binding protein α-2 subunit [ 26 ] without unambiguous demonstration, based on MS/MS data, of the sequence and PTMs of the corresponding farnesylated peptides. Building on our recent finding that endogenous lamin A and progerin can be measured by MS [ 7 ], we demonstrate here that immune-based approaches could be replaced with a LC-MS/MS-based method for the quantification of lamin A and post-translationally farnesylated progerin in cells from HGPS patients.…”

“…Approximately 90% of HGPS patients have a de novo heterozygous synonymous mutation at codon 608 (c.1824C>T; p.G608G) in the LMNA gene that activates the use of an internal 5′ splicing site in exon 11 and results in the synthesis of progerin, an unprocessed, farnesylated form of prelamin A ( Figure 1 ) [ 3 , 4 ]. Farnesylated progerin exerts a dominant-negative effect in cells and animal models of HGPS [ 5 ], and there is increasing evidence that disease severity and lifespan in progeria are largely determined by the total amount of farnesylated progerin and the ratio of progerin to mature lamin A [ 6 , 7 ]. While these findings paved the way to clinical trials with farnesyl transferase inhibitors (FTIs) [ 2 , 8 , 9 ], to date there have been no reports of reliable standardized methods for the quantification of the different lamin A proteoforms.…”