MG132 Induces Progerin Clearance and Improves Disease Phenotypes in HGPS-like Patients’ Cells

Progeroid syndromes (PS), including Hutchinson-Gilford Progeria Syndrome (HGPS), are premature and accelerated aging diseases, characterized by clinical features mimicking physiological aging. Most classical HGPS patients carry a de novo point mutation within exon 11 of the LMNA gene encoding A-type lamins. This mutation activates a cryptic splice site, leading to the production of a truncated prelamin A, called prelamin A ∆50 or progerin, that accumulates in HGPS cell nuclei and is a hallmark of the disease. Some patients with PS carry other LMNA mutations and are named “HGPS-like” patients. They produce progerin and/or other truncated prelamin A isoforms (∆35 and ∆90). We previously found that MG132, a proteasome inhibitor, induced progerin clearance in classical HGPS through autophagy activation and splicing regulation. Here, we show that MG132 induces aberrant prelamin A clearance and improves cellular phenotypes in HGPS-like patients’ cells other than those previously described in classical HGPS. These results provide preclinical proof of principle for the use of a promising class of molecules toward a potential therapy for children with HGPS-like or classical HGPS

Contribution to th study of the role of soluble CD146 in angiogenesis and effect pf P2Y12 receptor blockade on endothelial injury during percutaneous coronary intervention

Nous avons montré que la molécule recombinante humaine CD146 soluble (rh-sCD146) a un effet chimiotactique et angiogénique sur les cellules dérivées de progéniteurs endothéliaux (PEC) en augmentant leur capacité à migrer, à proliférer et à former des pseudo-capillaires. Des expériences réalisées in vivo sur un modèle d'ischémie de la patte chez le rat ont montré que des injections locales répétées de rh-sCD146 permettent une diminution significative du taux d'auto-amputation des animaux et une augmentation du taux de perfusion sanguin de la patte et de la densité capillaire. Dans une 2ème partie du travail, nous avons montré que l'angioplastie coronaire induit une hausse significative du nombre de cellules endothéliales circulantes (CEC) 6h après l'intervention (H6). Les lésions endothéliales, évaluées par la mesure de la variation du nombre de CEC (H6-H0), sont plus élevées chez les non-répondeurs par rapport aux bons répondeurs au Clopidogrel et sont corrélées à l'index VASPWe showed that the recombinant human soluble CD146 (rh-sCD146) has a chemotactic and angiogenic effect on endothelial progenitor derived cells (EPC) by increasing their ability to migrate, to proliferate and to form pseudo- capillaries. In an in vivo experiments model of ischemia in the rat by femoral artery ligation we showed that repeated local injections of rh-sCD146 for 12 days allows a significant reduction in the rate of animals self-amputation and an increase in the rate of blood perfusion of the leg and in the capillary density. In a second part of the work, we have shown that percutaneous coronary intervention induced a significant rise in circulating endothelial cells (CEC) levels 6h after the procedure (H6). The endothelial injury, assessed by CEC delta-change between H6 and H0, was significantly higher in the high on-treatment platelet reactivity group compared with the good responders to Clopidogrel and correlated with the Vasodilatator-Stimulated Phosphoprotein inde

Contribution à l'étude du rôle de CD146 soluble dans langiogenèse et de l'effet du blocage du récepteur P2Y12 sur la lésion endothéliale lors d'une angioplastie coronaire

Nous avons montré que la molécule recombinante humaine CD146 soluble (rh-sCD146) a un effet chimiotactique et angiogénique sur les cellules dérivées de progéniteurs endothéliaux (PEC) en augmentant leur capacité à migrer, à proliférer et à former des pseudo-capillaires. Des expériences réalisées in vivo sur un modèle d'ischémie de la patte chez le rat ont montré que des injections locales répétées de rh-sCD146 permettent une diminution significative du taux d'auto-amputation des animaux et une augmentation du taux de perfusion sanguin de la patte et de la densité capillaire. Dans une 2ème partie du travail, nous avons montré que l'angioplastie coronaire induit une hausse significative du nombre de cellules endothéliales circulantes (CEC) 6h après l'intervention (H6). Les lésions endothéliales, évaluées par la mesure de la variation du nombre de CEC (H6-H0), sont plus élevées chez les non-répondeurs par rapport aux bons répondeurs au Clopidogrel et sont corrélées à l'index VASPWe showed that the recombinant human soluble CD146 (rh-sCD146) has a chemotactic and angiogenic effect on endothelial progenitor derived cells (EPC) by increasing their ability to migrate, to proliferate and to form pseudo- capillaries. In an in vivo experiments model of ischemia in the rat by femoral artery ligation we showed that repeated local injections of rh-sCD146 for 12 days allows a significant reduction in the rate of animals self-amputation and an increase in the rate of blood perfusion of the leg and in the capillary density. In a second part of the work, we have shown that percutaneous coronary intervention induced a significant rise in circulating endothelial cells (CEC) levels 6h after the procedure (H6). The endothelial injury, assessed by CEC delta-change between H6 and H0, was significantly higher in the high on-treatment platelet reactivity group compared with the good responders to Clopidogrel and correlated with the Vasodilatator-Stimulated Phosphoprotein indexAIX-MARSEILLE2-Bib.electronique (130559901) / SudocSudocFranceF

Antisense-Based Progerin Downregulation in HGPS-Like Patients’ Cells

International audienceProgeroid laminopathies, including Hutchinson-Gilford Progeria Syndrome (HGPS, OMIM #176670), are premature and accelerated aging diseases caused by defects in nuclear A-type Lamins. Most HGPS patients carry a de novo point mutation within exon 11 of the LMNA gene encoding A-type Lamins. This mutation activates a cryptic splice site leading to the deletion of 50 amino acids at its carboxy-terminal domain, resulting in a truncated and permanently farnesylated Prelamin A called Prelamin A ∆50 or Progerin. Some patients carry other LMNA mutations affecting exon 11 splicing and are named " HGPS-like " patients. They also produce Progerin and/or other truncated Prelamin A isoforms (∆35 and ∆90) at the transcriptional and/or protein level. The results we present show that morpholino antisense oligonucleotides (AON) prevent pathogenic LMNA splicing, markedly reducing the accumulation of Progerin and/or other truncated Prelamin A isoforms (Prelamin A ∆35, Prelamin A ∆90) in HGPS-like patients' cells. Finally, a patient affected with Mandibuloacral Dysplasia type B (MAD-B, carrying a homozygous mutation in ZMPSTE24, encoding an enzyme involved in Prelamin A maturation, leading to accumulation of wild type farnesylated Prelamin A), was also included in this study. These results provide preclinical proof of principle for the use of a personalized antisense approach in HGPS-like and MAD-B patients, who may therefore be eligible for inclusion in a therapeutic trial based on this approach, together with classical HGPS patients

An overview of treatment strategies for Hutchinson-Gilford Progeria Syndrome

International audienc

MicroRNAs in hereditary and sporadic premature aging syndromes and other laminopathies

International audienceHereditary and sporadic laminopathies are caused by mutations in genes encoding lamins, their partners, or the metalloprotease ZMPSTE24/FACE1. Depending on the clinical phenotype, they are classified as tissue-specific or systemic diseases. The latter mostly manifest with several accelerated aging features, as in Hutchinson-Gil-ford progeria syndrome (HGPS) and other progeroid syndromes. MicroRNAs are small noncoding RNAs described as powerful regulators of gene expression, mainly by degrading target mRNAs or by inhibiting their translation. In recent years, the role of these small RNAs has become an object of study in laminopathies using in vitro or in vivo murine models as well as cells/tissues of patients. To date, few miRNAs have been reported to exert protective effects in laminopathies, including miR-9, which prevents progerin accumulation in HGPS neurons. The recent literature has described the potential implication of several other miRNAs in the patho-physiology of laminopathies, mostly by exerting deleterious effects. This review provides an overview of the current knowledge of the functional relevance and molecular insights of miRNAs in laminopathies. Furthermore, we discuss how these discoveries could help to better understand these diseases at the molecular level and could pave the way toward identifying new potential therapeutic targets and strategies based on miRNA modulation

Nuclear matrix, nuclear envelope and premature aging syndromes in a translational research perspective

International audienceLamin A-related progeroid syndromes are genetically determined, extremely rare and severe. In the past ten years, our knowledge and perspectives for these diseases has widely progressed, through the progressive dissection of their pathophysiological mechanisms leading to precocious and accelerated aging, from the genes mutations discovery until therapeutic trials in affected children. A-type lamins are major actors in several structural and functional activities at the nuclear periphery, as they are major components of the nuclear lamina. However, while this is usually poorly considered, they also play a key role within the rest of the nucleoplasm, whose defects are related to cell senescence. Although nuclear shape and nuclear envelope deformities are obvious and visible events, nuclear matrix disorganization and abnormal composition certainly represent the most important causes of cell defects with dramatic pathological consequences. Therefore, lamin-associated diseases should be better referred as laminopathies instead of envelopathies, this later being too restrictive, considering neither the key structural and functional roles of soluble lamins in the entire nucleoplasm, nor the nuclear matrix contribution to the pathophysiology of lamin-associated disorders and in particular in defective lamin A processing-associated aging diseases. Based on both our understanding of pathophysiological mechanisms and the biological and clinical consequences of progeria and related diseases, therapeutic trials have been conducted in patients and were terminated less than 10 years after the gene discovery, a quite fast issue for a genetic disease. Pharmacological drugs have been repurposed and used to decrease the toxicity of the accumulated, unprocessed and truncated prelaminA in progeria. To date, none of them may be considered as a cure for progeria and these clinical strategies were essentially designed toward reducing a subset of the most dramatic and morbid features associated to progeria. New therapeutic strategies under study, in particular targeting the protein expression pathway at the mRNA level, have shown a remarkable efficacy both in vitro in cells and in vivo in mice models. Strategies intending to clear the toxic accumulated proteins from the nucleus are also under evaluation. However, although exceedingly rare, improving our knowledge of genetic progeroid syndromes and searching for innovative and efficient therapies in these syndromes is of paramount importance as, even before they can be used to save lives, they may significantly (i) expand the affected childrens' lifespan and preserve their quality of life; (ii) improve our understanding of aging-related disorders and other more common diseases; and (iii) expand our fundamental knowledge of physiological aging and its links with major physiological processes such as those involved in oncogenesis

MG132-induced progerin clearance is mediated by autophagy activation and splicing regulation

International audienceHutchinson-Gilford progeria syndrome (HGPS) is a lethal premature and accelerated aging disease caused by a de novo point mutation in LMNA encoding A-type lamins. Progerin, a truncated and toxic prelamin A issued from aberrant splicing, accumulates in HGPS cells' nuclei and is a hallmark of the disease. Small amounts of progerin are also produced during normal aging. We show that progerin is sequestered into abnormally shaped promyelocytic nuclear bodies, identified as novel biomarkers in late passage HGPS cell lines. We found that the proteasome inhibitor MG132 induces progerin degradation through macroautophagy and strongly reduces progerin production through downregulation of SRSF-1 and SRSF-5 accumulation, controlling prelamin A mRNA aberrant splicing. MG132 treatment improves cellular HGPS phenotypes. MG132 injection in skeletal muscle of LmnaG609G/G609G mice locally reduces SRSF-1 expression and progerin levels. Altogether, we demonstrate progerin reduction based on MG132 dual action and shed light on a promising class of molecules toward a potential therapy for children with HGPS