Hutchinson-Gilford Progeria Syndrome Patients Research Articles

Inhibition of the NLRP3 inflammasome improves lifespan in animal murine model of Hutchinson-Gilford Progeria.

Inflammation is a hallmark of aging and accelerated aging syndromes such as Hutchinson–Gilford progeria syndrome (HGPS). In this study, we present evidence of increased expression of the components of the NLRP3 inflammasome pathway in HGPS skin fibroblasts, an outcome that was associated with morphological changes of the nuclei of the cells. Lymphoblasts from HGPS patients also showed increased basal levels of NLRP3 and caspase 1. Consistent with these results, the expression of caspase 1 and Nlrp3, but not of the other inflammasome receptors was higher in the heart and liver of Zmpste24−/− mice, which phenocopy the human disease. These data were further corroborated in LmnaG609G/G609G mice, another HGPS animal model. We also showed that pharmacological inhibition of the NLRP3 inflammasome by its selective inhibitor, MCC950, improved cellular phenotype, significantly extended the lifespan of progeroid animals, and reduced inflammasome‐dependent inflammation. These findings suggest that inhibition of the NLRP3 inflammasome is a potential therapeutic approach for the treatment of HGPS.

High-Throughput Screen Detects Calcium Signaling Dysfunction in Hutchinson-Gilford Progeria Syndrome.

Hutchinson–Gilford progeria syndrome (HGPS) is a deadly childhood disorder, which is considered a very rare disease. It is caused by an autosomal dominant mutation on the LMNA gene, and it is characterized by accelerated aging. Human cell lines from HGPS patients and healthy parental controls were studied in parallel using next-generation sequencing (NGS) to unravel new non-previously altered molecular pathways. Nine hundred and eleven transcripts were differentially expressed when comparing healthy versus HGPS cell lines from a total of 21,872 transcripts; ITPR1, ITPR3, CACNA2D1, and CAMK2N1 stood out among them due to their links with calcium signaling, and these were validated by Western blot analysis. It was observed that the basal concentration of intracellular Ca2+ was statistically higher in HGPS cell lines compared to healthy ones. The relationship between genes involved in Ca2+ signaling and mitochondria-associated membranes (MAM) was demonstrated through cytosolic calcium handling by means of an automated fluorescent plate reading system (FlexStation 3, Molecular Devices), and apoptosis and mitochondrial ROS production were examined by means of flow cytometry analysis. Altogether, our data suggest that the Ca2+ signaling pathway is altered in HGPS at least in part due to the overproduction of reactive oxygen species (ROS). Our results unravel a new therapeutic window for the treatment of this rare disease and open new strategies to study pathologies involving both accelerated and healthy aging.

Molecular and Cellular Mechanisms Driving Cardiovascular Disease in Hutchinson-Gilford Progeria Syndrome: Lessons Learned from Animal Models.

Hutchinson-Gilford progeria syndrome (HGPS) is a rare genetic disease that recapitulates many symptoms of physiological aging and precipitates death. Patients develop severe vascular alterations, mainly massive vascular smooth muscle cell loss, vessel stiffening, calcification, fibrosis, and generalized atherosclerosis, as well as electrical, structural, and functional anomalies in the heart. As a result, most HGPS patients die of myocardial infarction, heart failure, or stroke typically during the first or second decade of life. No cure exists for HGPS, and therefore it is of the utmost importance to define the mechanisms that control disease progression in order to develop new treatments to improve the life quality of patients and extend their lifespan. Since the discovery of the HGPS-causing mutation, several animal models have been generated to study multiple aspects of the syndrome and to analyze the contribution of different cell types to the acquisition of the HGPS-associated cardiovascular phenotype. This review discusses current knowledge about cardiovascular features in HGPS patients and animal models and the molecular and cellular mechanisms through which progerin causes cardiovascular disease.

CARDIAC DIFFERENTIATION OF INDUCED PLURIPOTENT STEM CELLS DERIVED FROM PATIENTS WITH HUTCHINSON-GILFORD PROGERIA SYNDROME

<h3>Background/Objective</h3> Hutchinson-Gilford Progeria Syndrome (HGPS) is caused by a single point mutation in the lamin A gene that leads to the production of a truncated protein, Progerin, and accelerated aging, which culminates in the patient's death mainly due to cardiovascular complications. Since the pathogenesis of HGPS shares some mechanisms with normal aging, it gives an opportunity to understand the cellular and molecular mechanisms of this natural phenomenon. Therefore, the aim of the present study was to generate cardiomyocytes from induced pluripotent stem cells of HGPS patients (HGPS-CM) in order to provide a powerful in vitro platform for the study of age-related cardiac disease. <h3>Methods</h3> Induced pluripotent stem cell line was obtained from the Progeria Research Foundation Cell and Tissue Bank (HGPS-iPSC). HGPS-iPSC pluripotency was characterized by RT-PCR. G-banding patterns were evaluated so as to ensure that these cells have a normal karyotype. For cardiomyocyte differentiation, 2,1 × 10⁵/cm² and 4,2 × 10⁵/cm² HGPS-iPSC were cultured for 30 days in RPMI 1640 medium supplemented with recombinant human albumin and L-ascorbic acid 2-phosphate. Forty-eight hours later (day 0), 5, 6, or 7 µM CHIR99021 was added to induce mesoderm formation. On day 2, 2 µM Wnt-C59 was used to specify in cardiogenic mesoderm. Progerin and SERCA2A expression in HGPS-iPSC and HGPS-CM were analyzed by RT-PCR. Cardiac differentiation efficiency was analyzed by the percentage of positive cells for cardiac troponin T using flow cytometry. Moreover, immunostaining for the same protein was performed to evaluate the contractile structure. <h3>Results</h3> HGPS-iPSC expressed OCT3/4, NANOG, SOX2, KLF4, confirming the pluripotent state and exhibited normal karyotype after fifty passages. After 10 days of differentiation, it was possible to visualize contractile cells only in 5 µM CHIR99021 condition, for both cell concentrations. On the thirtieth day of differentiation, progerin and SERCA2A mRNA were only detected in HGPS-CM and approximately seventy percent were positive to cardiac troponin T. Moreover, the presence of troponin T revealed that HGPS-iPSC derived cardiomyocytes showed a striated pattern, resembling sarcomere structures. <h3>Conclusions</h3> In this work, we established an efficient protocol to obtain cardiomyocytes using iPSC from HGPS patients, which can be used as an important tool for the study of novel mechanisms underlying cardiac aging.

The flavonoid morin alleviates nuclear deformation in aged cells by disrupting progerin-lamin A/C binding

• Progerin showed an abnormal binding affinity to the Ig-like domain of lamin A/C. • Morin significantly reduced the abnormal interaction between progerin and lamin. • Morin treatment of progerin-expressing and HGPS cells alleviated nuclear deformation. Nuclear lamin A/C plays an important role in maintaining the nuclear envelope structure. Hutchinson-Gilford progeria syndrome (HGPS) is a premature aging disease caused by a silent mutation in the lamin A/C gene, leading to the production of a C-terminally truncated protein (progerin). A deformed nuclear shape is a hallmark of HGPS cells, which observed in normal aged cells. A recent study has found that progerin can directly interact with lamin A/C, which leads to nuclear deformation. In this study, we identified natural compounds that can disrupt this progerin-mediated interaction. Similar to the synthetic compound JH4, morin disrupted this progerin-mediated interaction. Treatment with 20 μM morin ameliorated nuclear deformation by more than 50% in progerin-expressing cells. As morin is a naturally occurring substance with anti-oxidative activity, it may be developed as a functional food to improve the lifespan and health of both HGPS patients and normal aging individuals.

Enhanced Activity of Exportin-1/CRM1 in Neurons Contributes to Autophagy Dysfunction and Senescent Features in Old Mouse Brain.

Brain aging is characterized by dysfunctional autophagy and cellular senescence, among other features. While autophagy can either promote or suppress cellular senescence in proliferating cells, in postmitotic cells, such as neurons, autophagy impairment promotes cellular senescence. CRM1 (exportin-1/XPO1) exports hundreds of nuclear proteins into the cytoplasm, including the transcription factors TFEB (the main inducer of autophagy and lysosomal biogenesis genes) and STAT3, another autophagy modulator. It appears that CRM1 is a modulator of aging-associated senescence and autophagy, because pharmacological inhibition of CRM1 improved autophagic degradation in flies, by increasing nuclear TFEB levels, and because enhanced CRM1 activity is mechanistically linked to senescence in fibroblasts from Hutchinson–Gilford progeria syndrome patients and old healthy individuals; furthermore, the exogenous overexpression of CRM1 induced senescence in normal fibroblasts. In this work, we tested the hypothesis that impaired autophagic flux during brain aging occurs due to CRM1 accumulation in the brain. We found that CRM1 levels and activity increased in the hippocampus and cortex during physiological aging, which resulted in a decrease of nuclear TFEB and STAT3. Consistent with an autophagic flux impairment, we observed accumulation of the autophagic receptor p62/SQSTM1 in neurons of old mice, which correlated with increased neuronal senescence. Using an in vitro model of neuronal senescence, we demonstrate that CRM1 inhibition improved autophagy flux and reduced SA-β-gal activity by restoring TFEB nuclear localization. Collectively, our data suggest that enhanced CRM1-mediated export of proteins during brain aging perturbs neuronal homeostasis, contributing to autophagy impairment, and neuronal senescence.

Farnesyltransferase inhibition in HGPS

The ultra-rare, pediatric premature aging disorder Hutchinson-Gilford progeria syndrome (HGPS) is caused by mutation of LMNA, encoding the nuclear architectural protein lamin A. Patients develop atherosclerosis and typically die of heart failure in their teens. FDA-approved Zokinvy prevents farnesylation of lamin A, reduces vascular stiffness, and extends survival in HGPS patients. To view this Bench to Bedside, open or download the PDF.

ESCRT-III controls nuclear envelope deformation induced by progerin

Hutchinson-Gilford progeria syndrome (HGPS) is a premature aging disorder, caused by mutation in the gene encoding lamin A/C, which produces a truncated protein called progerin. In cells from HGPS patients, progerin accumulates at the nuclear membrane (NM), where it causes NM deformations. In this study, we investigated whether progerin-induced NM deformation involved ESCRT-III, a protein complex that remodels nuclear and cytoplasmic membranes. The ESCRT-III protein CHMP4B was recruited to sites of aberrant NM proliferation in human cells ectopically expressing progerin and in patient-derived HGPS fibroblasts. Derepression of NM deformation in these cells was observed following depletion of CHMP4B or an ESCRT-III adaptor, ALIX. Treatment with rapamycin (which induce autophagic clearance of progerin and reverse progerin-induced cellular phenotypes) down-regulated progerin-induced NM deformation, whereas treatment with bafilomycin A1 (an inhibitor of autophagy and lysosome-based degradation) or CHMP4B depletion antagonized the effects of rapamycin. These results indicate that the ALIX-mediated ESCRT-III pathway plays a suppressive role in progerin-induced NM deformation and suggest that autophagy down-regulates progerin-induced NM deformation in a manner dependent on ESCRT-III machinery.

Premature Vascular Aging with Features of Plaque Vulnerability in an Atheroprone Mouse Model of Hutchinson-Gilford Progeria Syndrome with Ldlr Deficiency.

Hutchinson–Gilford progeria syndrome (HGPS) is among the most devastating of the laminopathies, rare genetic diseases caused by mutations in genes encoding nuclear lamina proteins. HGPS patients age prematurely and die in adolescence, typically of atherosclerosis-associated complications. The mechanisms of HGPS-related atherosclerosis are not fully understood due to the scarcity of patient-derived samples and the availability of only one atheroprone mouse model of the disease. Here, we generated a new atherosusceptible model of HGPS by crossing progeroid LmnaG609G/G609G mice, which carry a disease-causing mutation in the Lmna gene, with Ldlr−/− mice, a commonly used preclinical atherosclerosis model. Ldlr−/−LmnaG609G/G609G mice aged prematurely and had reduced body weight and survival. Compared with control mice, Ldlr−/−LmnaG609G/G609G mouse aortas showed a higher atherosclerosis burden and structural abnormalities typical of HGPS patients, including vascular smooth muscle cell depletion in the media, adventitial thickening, and elastin structure alterations. Atheromas of Ldlr−/−LmnaG609G/G609G mice had features of unstable plaques, including the presence of erythrocytes and iron deposits and reduced smooth muscle cell and collagen content. Ldlr−/−LmnaG609G/G609G mice faithfully recapitulate vascular features found in patients and thus provide a new tool for studying the mechanisms of HGPS-related atherosclerosis and for testing therapies.

Abstract 19: Targeting Delta133p53 isoform with small-molecule compounds to modulate cellular senescence

Abstract Cellular senescence (CS) and senescence-associated secretory phenotype (SASP) contribute to aging and age-related diseases. Mechanistically, the stress sensor p53 plays a pivotal role in the initiation and maintenance of CS. In humans, TP53 is expressed as 12 isoforms that contribute to the fine-tuning of p53 activity. Delta133p53 is generated from an alternative promoter located in intron 4 and is therefore devoid of both the transactivation domain and part of the DNA binding domain. Delta133p53 is predominantly located in the nucleus and is largely regulated at the protein level through chaperone-assisted selective autophagic degradation. Delta133p53 counteracts p53-mediated replicative CS and reduces the secretion of SASP cytokines. Delta133p53 is expressed in most normal tissues, but its expression is deregulated in age-associated diseases such as cancer, neurodegenerative diseases, and premature aging disorders. Delta133p53 is downregulated in exhausted CD8+ T cells, nearly senescent fibroblasts from Hutchinson-Gilford progeria syndrome patients, and astrocytes from irradiated brains and Alzheimer’s disease and amyotrophic lateral sclerosis patients. Delta133p53 overexpression extends the replicative lifespan in normal cells but does not cause immortalization or malignant transformation. Hence, delta133p53 appears to be a safe, novel therapeutic target to regulate CS. The present study aims at identifying small-molecule compounds that stabilize or prevent the degradation of delta133p53 protein and inhibit CS. To screen for activators of delta133p53, we developed two cell-based high-throughput screening (HTS) assays using an inducible vector for the expression of an eGFP-tag recombinant protein, and a luminescent peptide tag (HiBiT) appended onto the endogenous gene. The biologic activity of the fusion proteins was confirmed by evaluating the i) nuclear localization, ii) autophagic degradation during CS, and iii) ability to delay replicative CS. In collaboration with the National Center for Advancing Translational Sciences (NCATS), we screened a collection of ~8,350 compounds that includes all drugs that have been approved for use by the US Food and Drug Administration. Selected compounds were then screened in a secondary assay to evaluate their efficacy at reducing SASP cytokines secretion. Several candidate compounds are currently being investigated to confirm their effect on endogenous delta133p53 expression and CS. We have established robust cell-based HTS assays to screen for activators of delta133p53 and identified candidate compounds that could potentially develop into novel therapeutic leads to treat major life-threatening diseases. Citation Format: Delphine Lissa, Kyra Ungerleider, Izumi Horikawa, Patricia Dranchak, Erin Oliphan, Jessica Beck, Sebastien Jo, James Inglese, Curtis C. Harris. Targeting Delta133p53 isoform with small-molecule compounds to modulate cellular senescence [abstract]. In: Proceedings of the AACR Special Conference on Advancing Precision Medicine Drug Development: Incorporation of Real-World Data and Other Novel Strategies; Jan 9-12, 2020; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(12_Suppl_1):Abstract nr 19.

Development of a new drug for progeria syndrome; Past, Present and Future

Hutchinson-Gilford progeria syndrome (HGPS) is the best characterized genetic disorder with premature aging features. Classic HGPS is very rare, sporadic orphan disease, inherited in an autosomal dominant manner without gender or ethnic differences. Children with HGPS appear normal at birth, but begin to develop segmental progeroid symptoms within the first years of life. Patients suffer from sarcopenia, lipodystrophy, diabetes, cataracts, atherosclerosis but not cancer and neurodegenerative diseases. Genetic factors that are associated with this syndrome have been identified, mouse models of disease have been developed, and clinical studies have been conducted for many years. Although many medical and treatment approaches were implemented and showed some efficacy, these therapies could not be considered as a complete cure, and more effective therapeutic approaches were needed for HGPS patients. This report introduces a novel drug called progerinin, which is a binding inhibitor of lamin A and progerin, for patients affected with HGPS.

Progerin Expression Induces Inflammation, Oxidative Stress and Senescence in Human Coronary Endothelial Cells.

Hutchinson–Gilford progeria syndrome (HGPS) is a rare premature aging disorder notably characterized by precocious and deadly atherosclerosis. Almost 90% of HGPS patients carry a LMNA p.G608G splice variant that leads to the expression of a permanently farnesylated abnormal form of prelamin-A, referred to as progerin. Endothelial dysfunction is a key determinant of atherosclerosis, notably during aging. Previous studies have shown that progerin accumulates in HGPS patients’ endothelial cells but also during vascular physiological aging. However, whether progerin expression in human endothelial cells can recapitulate features of endothelial dysfunction is currently unknown. Herein, we evaluated the direct impact of exogenously expressed progerin and wild-type lamin-A on human endothelial cell function and senescence. Our data demonstrate that progerin, but not wild-type lamin-A, overexpression induces endothelial cell dysfunction, characterized by increased inflammation and oxidative stress together with persistent DNA damage, increased cell cycle arrest protein expression and cellular senescence. Inhibition of progerin prenylation using a pravastatin–zoledronate combination partly prevents these defects. Our data suggest a direct proatherogenic role of progerin in human endothelial cells, which could contribute to HGPS-associated early atherosclerosis and also potentially be involved in physiological endothelial aging participating to age-related cardiometabolic diseases.

Accumulation of prelamin A induces premature aging through mTOR overactivation.

Hutchinson-Gilford progeria syndrome (HGPS) arises when a truncated form of farnesylated prelamin A accumulates at the nuclear envelope, leading to misshapen nuclei. Previous studies of adult Zmpste24-deficient mice, a mouse model of progeria, have reported a metabolic response involving inhibition of the mTOR (mammalian target of rapamycin) kinase and activation of autophagy. However, exactly how mTOR or autophagy is involved in progeria remains unclear. Here, we investigate this question by crossing Zmpste24+/- mice with mice hypomorphic in mTOR (mTOR△/+ ), or mice heterozygous in autophagy-related gene 7 (Atg7+/- ). We find that accumulation of prelamin A induces premature aging through mTOR overactivation and impaired autophagy in newborn Zmpste24-/- mice. Zmpste24-/- mice with genetically reduced mTOR activity, but not heterozygosity in Atg7, show extended lifespan. Moreover, mTOR inhibition partially restores autophagy and S6K1 activity. We also show that progerin interacts with the Akt phosphatase to promote full activation of the Akt/mTOR signaling pathway. Finally, although we find that genetic reduction of mTOR postpones premature aging in Zmpste24 KO mice, frequent embryonic lethality occurs. Together, our findings show that over-activated mTOR contributes to premature aging in Zmpste24-/- mice, and suggest a potential strategy in treating HGPS patients with mTOR inhibitors.

Vascular Smooth Muscle Cell-Specific Progerin Expression Provokes Contractile Impairment in a Mouse Model of Hutchinson-Gilford Progeria Syndrome that Is Ameliorated by Nitrite Treatment.

Cardiovascular disease (CVD) is the main cause of death worldwide, and aging is its leading risk factor. Aging is much accelerated in Hutchinson–Gilford progeria syndrome (HGPS), an ultra-rare genetic disorder provoked by the ubiquitous expression of a mutant protein called progerin. HGPS patients die in their teens, primarily due to cardiovascular complications. The primary causes of age-associated CVD are endothelial dysfunction and dysregulated vascular tone; however, their contribution to progerin-induced CVD remains poorly characterized. In the present study, we found that progeroid LmnaG609G/G609G mice with ubiquitous progerin expression show both endothelial dysfunction and severe contractile impairment. To assess the relative contribution of specific vascular cell types to these anomalies, we examined LmnaLCS/LCSTie2Cretg/+ and LmnaLCS/LCSSm22αCretg/+ mice, which express progerin specifically in endothelial cells (ECs) and vascular smooth muscle cells (VSMCs), respectively. Whereas vessel contraction was impaired in mice with VSMC-specific progerin expression, we observed no endothelial dysfunction in mice with progerin expression restricted to VSMCs or ECs. Vascular tone regulation in progeroid mice was ameliorated by dietary sodium nitrite supplementation. Our results identify VSMCs as the main cell type causing contractile impairment in a mouse model of HGPS that is ameliorated by nitrite treatment.

Metabolic Dysfunction in Hutchinson–Gilford Progeria Syndrome

Hutchinson–Gilford Progeria Syndrome (HGPS) is a segmental premature aging disease causing patient death by early teenage years from cardiovascular dysfunction. Although HGPS does not totally recapitulate normal aging, it does harbor many similarities to the normal aging process, with patients also developing cardiovascular disease, alopecia, bone and joint abnormalities, and adipose changes. It is unsurprising, then, that as physicians and scientists have searched for treatments for HGPS, they have targeted many pathways known to be involved in normal aging, including inflammation, DNA damage, epigenetic changes, and stem cell exhaustion. Although less studied at a mechanistic level, severe metabolic problems are observed in HGPS patients. Interestingly, new research in animal models of HGPS has demonstrated impressive lifespan improvements secondary to metabolic interventions. As such, further understanding metabolism, its contribution to HGPS, and its therapeutic potential has far-reaching ramifications for this disease still lacking a robust treatment strategy.

IPSC-Derived Endothelial Cells Affect Vascular Function in a Tissue-Engineered Blood Vessel Model of Hutchinson-Gilford Progeria Syndrome.

SummaryHutchinson-Gilford progeria syndrome (HGPS) is a rare disorder caused by a point mutation in the Lamin A gene that produces the protein progerin. Progerin toxicity leads to accelerated aging and death from cardiovascular disease. To elucidate the effects of progerin on endothelial cells, we prepared tissue-engineered blood vessels (viTEBVs) using induced pluripotent stem cell-derived smooth muscle cells (viSMCs) and endothelial cells (viECs) from HGPS patients. HGPS viECs aligned with flow but exhibited reduced flow-responsive gene expression and altered NOS3 levels. Relative to viTEBVs with healthy cells, HGPS viTEBVs showed reduced function and exhibited markers of cardiovascular disease associated with endothelium. HGPS viTEBVs exhibited a reduction in both vasoconstriction and vasodilation. Preparing viTEBVs with HGPS viECs and healthy viSMCs only reduced vasodilation. Furthermore, HGPS viECs produced VCAM1 and E-selectin protein in TEBVs with healthy or HGPS viSMCs. In summary, the viTEBV model has identified a role of the endothelium in HGPS.

Dysfunction of iPSC-derived endothelial cells in human Hutchinson–Gilford progeria syndrome

ABSTRACT Children with Hutchinson–Gilford progeria syndrome (HGPS) succumb to myocardial infarction and stroke in their teen years. Endothelial dysfunction is an early event in more common forms of atherosclerosis. Endothelial pathobiology may contribute to HGPS, but a comprehensive characterization of endothelial function in HGPS has not been performed. iPSCs derived from fibroblasts of HGPS patients or unaffected relatives were differentiated into endothelial cells (ECs). Immunofluorescent signal of the pluripotent stem cell markers SSEA4, Oct4, Sox2 and TRAI-60 was similar in HGPS or control iPSCs. Following the differentiation, FACS analysis and immunocytochemistry for CD31 and CD144 revealed a smaller percentage of ECs from HGPS iPSCs. Immunostaining for Lamin A revealed nuclear dysmorphology in HGPS iPSC-ECs. Furthermore, these cells were significantly larger and rounded, and they proliferated less, features which are typical of senescent endothelial cells. HGPS iPSC-ECs manifested less Dil-Ac-LDL uptake; less DAF-2DA staining for nitric oxide generation and formed fewer networks in matrigel in vitro. In immunodeficient mice injected with iPSC-ECs, HGPS iPSC-ECs generated a sparser vascular network compared to the control, with reduced capillary number. Telomere length (T/S ratio) of HGPS iPSC-EC was reduced as assessed by mmqPCR. iPSC-ECs derived from HGPS patients have dysmorphic appearance, abnormal nuclear morphology, shortened telomeres, reduced replicative capacity and impaired functions in vitro and in vivo. Targeting the endothelial abnormality in patients with HGPS may provide a new therapeutic avenue for the treatment of this condition. Abbreviations: HGPS: Hutchinson–Gilford progeria syndrome; ZMPSTE24: Zinc metallopeptidase STE24; FTI: Farnesyltransferase inhibitors; VSMCs: Vascular smooth muscle cells; iPSC: Induced pluripotent stem cells; EC: Endothelial cells; hTERT: Human telomerase reverse transcriptase; VEGF: vascular endothelial growth factor; DAF-FM DA: 3-Amino, 4-aminomethyl-2’,7’-difluorofluorescein diacetate; BMP4: Bone Morphogenetic Protein 4; mmqPCR: mono chrome multiplex PCR; SCG: single-copy gene; CSI: Cell shape index.

Metabolomic profiling suggests systemic signatures of premature aging induced by Hutchinson-Gilford progeria syndrome.

Hutchinson-Gilford Progeria Syndrome (HGPS) is an extremely rare genetic disorder. HGPS children present a high incidence of cardiovascular complications along with altered metabolic processes and an accelerated aging process. No metabolic biomarker is known and the mechanisms underlying premature aging are not fully understood. The present work aims to evaluate the metabolic alterations in HGPS using high resolution mass spectrometry. The present study analyzed plasma from six HGPS patients of both sexes (7.7 ± 1.4years old; mean ± SD) and eight controls (8.6 ± 2.3years old) by LC-MS/MS in high-resolution non-targeted metabolomics (Q-Exactive Plus). Targeted metabolomics was used to validate some of the metabolites identified by the non-targeted method in a triple quadrupole (TSQ-Quantiva). We found several endogenous metabolites with statistical differences between control and HGPS children. Multivariate statistical analysis showed a clear separation between groups. Potential novel metabolic biomarkers were identified using the multivariate area under ROC curve (AUROC) based analysis, showing an AUC value higher than 0.80 using only two metabolites, and tending to 1.00 when increasing the number of metabolites in the AUROC model. Taken together, changed metabolic pathways involve sphingolipids, amino acids, and oxidation of fatty acids, among others. Our data show significant alterations in cellular energy use and availability, in signal transduction, and lipid metabolites, adding new insights on metabolic alterations associated with premature aging and suggesting novel putative biomarkers.

Are There Common Mechanisms Between the Hutchinson-Gilford Progeria Syndrome and Natural Aging?

The Hutchinson–Gilford progeria syndrome (HGPS) is a premature aging disease caused by mutations of the LMNA gene leading to increased production of a partially processed form of the nuclear fibrillar protein lamin A – progerin. Progerin acts as a dominant factor that leads to multiple morphological anomalies of cell nuclei and disturbances in heterochromatin organization, mitosis, DNA replication and repair, and gene transcription. Progerin-positive cells are present in primary fibroblast cultures obtained from the skin of normal donors at advanced ages. These cells display HGPS-like defects in nuclear morphology, decreased H3K9me3 and HP1, and increased histone H2AX phosphorylation marks of the DNA damage loci. Inhibition of progerin production in cells of aged non-HGPS donors in vivo increases the proliferative activity, H3K9me3, and HP1, and decreases the senescence markers p21, IGFBP3, and GADD45B to the levels of young donor cells. Thus, progerin-dependent mechanisms act in natural aging. Excessive activity of the same mechanisms may well be the cause of premature aging in HGPS. Telomere attrition is widely regarded to be one of the primary hallmarks of aging. Progerin expression in normal human fibroblasts accelerates the loss of telomeres. Changes in lamina organization may directly affect telomere attrition resulting in accelerated replicative senescence and progeroid phenotypes. The chronological aging in normal individuals and the premature aging in HGPS patients are mediated by similar changes in the activity of signaling pathways, including downregulation of DNA repair and chromatin organization, and upregulation of ERK, mTOR, GH-IGF1, MAPK, TGFβ, and mitochondrial dysfunction. Multiple epigenetic changes are common to premature aging in HGPS and natural aging. Recent studies showed that epigenetic systems could play an active role as drivers of both forms of aging. It may be suggested that these systems translate the effects of various internal and external factors into universal molecular hallmarks, largely common between natural and accelerated forms of aging. Drugs acting at both natural aging and HGPS are likely to exist. For example, vitamin D3 reduces the progerin production and alleviates most HGPS features, and also slows down epigenetic aging in overweight and obese non-HGPS individuals with suboptimal vitamin D status.

Generation and characterization of a novel knockin minipig model of Hutchinson-Gilford progeria syndrome

Hutchinson-Gilford progeria syndrome (HGPS) is an extremely rare genetic disorder for which no cure exists. The disease is characterized by premature aging and inevitable death in adolescence due to cardiovascular complications. Most HGPS patients carry a heterozygous de novo LMNA c.1824C > T mutation, which provokes the expression of a dominant-negative mutant protein called progerin. Therapies proven effective in HGPS-like mouse models have yielded only modest benefit in HGPS clinical trials. To overcome the gap between HGPS mouse models and patients, we have generated by CRISPR-Cas9 gene editing the first large animal model for HGPS, a knockin heterozygous LMNA c.1824C > T Yucatan minipig. Like HGPS patients, HGPS minipigs endogenously co-express progerin and normal lamin A/C, and exhibit severe growth retardation, lipodystrophy, skin and bone alterations, cardiovascular disease, and die around puberty. Remarkably, the HGPS minipigs recapitulate critical cardiovascular alterations seen in patients, such as left ventricular diastolic dysfunction, altered cardiac electrical activity, and loss of vascular smooth muscle cells. Our analysis also revealed reduced myocardial perfusion due to microvascular damage and myocardial interstitial fibrosis, previously undescribed readouts potentially useful for monitoring disease progression in patients. The HGPS minipigs provide an appropriate preclinical model in which to test human-size interventional devices and optimize candidate therapies before advancing to clinical trials, thus accelerating the development of effective applications for HGPS patients.