Drug screening on Hutchinson Gilford progeria pluripotent stem cells reveals aminopyrimidines as new modulators of farnesylation

Abstract

Hutchinson-Gilford progeria syndrome (HGPS) is a rare genetic disorder characterized by a dramatic appearance of premature aging. HGPS is due to a single-base substitution in exon 11 of the LMNA gene (c.1824C>T) leading to the production of a toxic form of the prelamin A protein called progerin. Because farnesylation process had been shown to control progerin toxicity, in this study we have developed a screening method permitting to identify new pharmacological inhibitors of farnesylation. For this, we have used the unique potential of pluripotent stem cells to have access to an unlimited and relevant biological resource and test 21 608 small molecules. This study identified several compounds, called monoaminopyrimidines, which target two key enzymes of the farnesylation process, farnesyl pyrophosphate synthase and farnesyl transferase, and rescue in vitro phenotypes associated with HGPS. Our results opens up new therapeutic possibilities for the treatment of HGPS by identifying a new family of protein farnesylation inhibitors, and which may also be applicable to cancers and diseases associated with mutations that involve farnesylated proteins.

A High Throughput Phenotypic Screening reveals compounds that counteract premature osteogenic differentiation of HGPS iPS-derived mesenchymal stem cells

“…It has not been possible, to our knowledge, to produce the large cell banks required for such an approach from prematurely senescent HGPS primary cells. In order to overcome this problem, two complementary cellular models have been designed, one of which involves overexpressing an inducible progerin in healthy cells 19 and the other, the reprogramming of patient cells into induced pluripotent stem cells (iPSCs) 20 .…”

High-Throughput Imaging for the Discovery of Cellular Mechanisms of Disease

“…The effect of retinoids is mostly liked due to the presence of a retinoic acid response element in the promoter of the LMNA gene, resulting in repression of progerin expression in the presence of retinoids [59]. HGPS MSC cells were also used in an HTI-based drug screen for the discovery of novel farnesyl transferase inhibitors (FTI) [60], the first class of compounds under clinical trial evaluation for HGPS [61]. A high-throughput antibody-based assay using these cells identified a validated set of 11 active compounds, including 6 containing one or more aminopyrimidine (AP) groups, in a screen of 21,608 small molecules [60].…”

“…HGPS MSC cells were also used in an HTI-based drug screen for the discovery of novel farnesyl transferase inhibitors (FTI) [60], the first class of compounds under clinical trial evaluation for HGPS [61]. A high-throughput antibody-based assay using these cells identified a validated set of 11 active compounds, including 6 containing one or more aminopyrimidine (AP) groups, in a screen of 21,608 small molecules [60]. Using the previously reported premature osteogenic differentiation of HGPS cells as an assay [58], and an HTI assay measuring nuclear morphological defects in HGPS MSC cells, mono-aminopyrimidines (Mono-AP’s) acted as particularly potent suppressors of HGPS phenotypes, possibly by directly binding and inhibiting farnesyltransferase (FT) and farnesyl pyrophosphate synthase (FFPS), two enzymes involved in prelamin A farnesylation.…”

“…iPS cells can be obtained from reprogramming of patient cells, are genomically stable, can be propagated indefinitely, and can be differentiated in a variety of cell lineages to model disease in relevant cell types. In addition to the previously mentioned HGPS-iPS cells [58,60], iPS cells obtained from patients affected by sporadic amyotrophic lateral sclerosis (sALS) were differentiated into motor neurons and used in an endpoint assay to screen 1,757 bioactive compounds by measuring aggregation of the RNA binding protein TDP-43 in the nucleus via HTI [67]. A similar approach using embryonic stem cells (ESC) derived motor neurons and microglia was used to screen for compounds protecting from neurodegeneration associated with microglial activation [68], or X-linked Fragile Mental Retardation (FMR) patient-derived reprogrammed iPS cells to identify small molecules relieving the epigenetic silencing of the FMRP protein [69].…”

Nuclear envelopathies: a complex LINC between nuclear envelope and pathology

“…Recently, a drug screening approach on iPS cell lines derived from HGPS patients identified mono-aminipyrimidines (mono-APs) as a family of molecules capable to restore HGPS cellular phenotype. Mono-APs act at two different levels: they inhibit both farnesyl pyrophosphate synthase and farnesyl transferase [ 78 ]. The same way, a drug testing approach on HGPS patient fibroblasts led to the discovery of a small molecule, called by the authors “remodelin”, able to improve nuclear architecture in these cells.…”