Cardiovascular manifestations of Hutchinson–Gilford progeria syndrome

Cardiovascular complications are the most frequent cause of death in patients with the Hutchinson–Gilford progeria syndrome. However, due to its rarity, studying the course of cardiac abnormalities has been a challenge. The cardiovascular phenotype helps to provide greater insight into the natural history of these abnormalities.

Lonafarnib improves cardiovascular function and survival in a mouse model of Hutchinson-Gilford Progeria Syndrome

Clinical trials have demonstrated that lonafarnib, a farnesyltransferase inhibitor, extends lifespan in patients afflicted by Hutchinson-Gilford progeria syndrome, a devastating condition that accelerates many characteristics of aging and results in premature death due to cardiovascular sequelae. The US Food and Drug Administration approved ZokinvyTM (lonafarnib) in November 2020 for treating these patients, yet a detailed examination of drug-associated effects on cardiovascular structure, properties, and function has remained wanting. In this paper, we report encouraging outcomes of daily post-weaning treatment with lonafarnib on the composition and biomechanical phenotype of elastic and muscular arteries as well as associated cardiac function in a well-accepted mouse model of progeria that exhibits severe end-stage cardiovascular disease. Lonafarnib resulted in 100% survival of the treated progeria mice to the study end-point (time of 50% survival of untreated mice), with associated improvements in arterial structure and function working together to significantly reduce pulse wave velocity and improve left ventricular diastolic function. By contrast, dual treatment with lonafarnib and rapamycin did not improve outcomes over that achieved with lonafarnib monotherapy.

Efficacy of Cord Blood Cell Therapy for Hutchinson–Gilford Progeria Syndrome—A Case Report

Hutchinson–Gilford progeria syndrome (HGPS) is an extremely rare premature aging disorder characterized by short stature and atherosclerosis-induced death within teenage years. A 13-year-old male diagnosed with HGPS was administered three intravenous infusions of allogeneic cord blood (CB) cells from unrelated donors at four-month intervals to evaluate the safety and its therapeutic efficacy. Adverse events were monitored in addition to height, weight, laboratory blood tests, joint range of motion (ROM), and carotid Doppler. Cytokine and receptor assays were also performed. The patient exhibited an increase in growth rate for both height and weight. One year after therapy initiation, evident amelioration in pulse wave velocity, bilateral maximal intima-media thickness, and dyslipidemic status were observed, which were in abrupt aggravation prior to treatment. Further, an increase in flexibility occurred in some joints of the upper extremities. No serious adverse events were observed throughout the study period and one year beyond. A molecular assay revealed downregulation of proinflammatory and atherosclerosis, representing cytokine expressions following the administration of CB cells. This is the first reported case of an allogeneic CB trial in a patient with HGPS showing therapeutic effects of CB with improvements in anthropometric measures, joint ROM with amelioration of atherosclerosis, and dyslipidemia induced by anti-inflammatory and anti-atherosclerotic responses.

Abolishing the prelamin A ZMPSTE24 cleavage site leads to progeroid phenotypes with near-normal longevity in mice

Prelamin A is a farnesylated precursor of lamin A, a nuclear lamina protein. Accumulation of the farnesylated prelamin A variant progerin, with an internal deletion including its processing site, causes Hutchinson-Gilford progeria syndrome. Loss of function mutations in ZMPSTE24, which encodes the prelamin A processing enzyme, lead to accumulation of full-length farnesylated prelamin A and cause related progeroid disorders. Some data suggest that prelamin A also accumulates with physiological aging. Zmpste24-/- mice die young, at ~20 weeks. Because ZMPSTE24 has functions in addition to prelamin A processing, we generated a mouse model to examine effects solely due to the presence of permanently farnesylated prelamin A. These mice have an L648R amino acid substitution in prelamin A that blocks ZMPSTE24-catalyzed processing to lamin A. The LmnaL648R/L648R mice express only prelamin and no mature protein. Notably, nearly all survive to 65-70 weeks, with approximately 40% of male and 75% of female LmnaL648R/L648R having near-normal lifespans of almost 2 years. Starting at ~10 weeks of age, LmnaL648R/L648R mice of both sexes have lower body masses and body fat than controls. By ~20-30 weeks of age, they exhibit detectable cranial, mandibular and dental defects similar to those observed in Zmpste24-/- mice, and have decreased vertebral bone density compared to age- and sex-matched controls. Cultured embryonic fibroblasts from LmnaL648R/L648R mice have aberrant nuclear morphology that is reversible by treatment with a protein farnesyltransferase inhibitor. These novel mice provide a robust model to study the effects of farnesylated prelamin A during physiological aging.

Targeting SerpinE1 reverses cellular features of Hutchinson-Gilford progeria syndrome

Hutchinson-Gilford progeria syndrome (HGPS) is a rare, fatal disease caused by Lamin A mutation, leading to altered nuclear architecture, loss of perinuclear heterochromatin and deregulated gene expression. HGPS patients eventually die by coronary artery disease and cardiovascular alterations. However, how deregulated transcriptional networks at the cellular level impact on the systemic disease phenotype is currently unclear. We have performed a longitudinal genome-wide analysis of gene expression in primary HGPS fibroblasts from patients at two sequential stages of disease that revealed a progressive activation of Rho signaling and SerpinE1, also known as Plasminogen Activator Inhibitor (PAI-1). siRNA-mediated downregulation or pharmacological inhibition of SerpinE1 by TM5441 could revert key pathological features of HGPS in patient-derived fibroblasts, including re-activation of cell cycle progression, reduced DNA damage signaling, decreased expression of pro-fibrotic genes and recovery of mitochondrial defects. These effects were accompanied by reduced levels of Progerin and correction of nuclear abnormalities. These data point to SerpinE1 as a novel potential effector of HGPS pathogenesis and target for therapeutic interventions.

Hutchinson–Gilford Progeria Syndrome (Hgps) And Application Of Gene Therapy Based Crispr/Cas Technology As A Promising Innovative Treatment Approach

Background: Hutchinson–Gilford progeria syndrome (HGPS) also known as progeria of childhood or progeria is a rare, rapid, autosomal dominant genetic disorder characterized by premature aging which occurs shortly after birth. HGPS occurs as a result of de novo point mutation in the gene recognized as LMNA gene that encodes two proteins Lamin A protein and Lamin C protein which are the structural components of the nuclear envelope. Mutations in the gene trigger abnormal splicing and induce internal deletion of 50 amino acids leading to the development of a truncated form of Lamin A protein known as Progerin. Progerin generation can be considered as the crucial step in HGPS since the protein is highly toxic to human cells, permanently farnesylated, and exhibits variation in several biochemical and structural properties within the individual. HGPS also produces complications such as skin alterations, growth failure, atherosclerosis, hair and fat loss, and bone and joint diseases. We have also revised all relevant patents relating to Hutchinson-gilford progeria syndrome and its therapy in the current article. Method: The goal of the present review article is to provide information about Hutchinson–Gilford progeria syndrome (HGPS) and the use of CRISPR/Cas technology as a promising treatment approach in the treatment of the disease. The review also discusses about different pharmacological and non-pharmacological methods of treatment currently used for HGPS. Results : The main limitation associated with progeria is the lack of a definitive cure. The existing treatment modality provides only symptomatic relief. Therefore, it is high time to develop a therapeutic method that hastens premature aging in such patients. Conclusion: CRISPR/Cas technology is a novel gene-editing tool that allows genome editing at specific loci, and is found to be a promising therapeutic approach for the treatment of genetic disorders such as HGPS where dominant-negative mutations take place.

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.