Emerging candidate treatment strategies for Hutchinson-Gilford progeria syndrome

Mitophagy defect mediates the aging-associated hallmarks in Hutchinson-Gilford progeria syndrome

Hutchinson-Gilford progeria syndrome (HGPS) is a rare and fatal disease manifested by premature aging and aging-related phenotypes, making it a disease model for aging. The cellular machinery mediating age-associated phenotypes in HGPS remains largely unknown, resulting in limited therapeutic targets for HGPS. In this study, we showed that mitophagy defects impaired mitochondrial function and contributed to cellular markers associated with aging in mesenchymal stem cells derived from HGPS patients (HGPS-MSCs). Mechanistically, we discovered that mitophagy affected the aging-associated phenotypes of HGPS-MSCs by inhibiting the STING-NF-ĸB pathway and the downstream transcription of senescence-associated secretory phenotypes (SASPs). Furthermore, by utilizing UMI-77, an effective mitophagy inducer, we showed that mitophagy induction alleviated aging-associated phenotypes in HGPS and naturally aged mice. Collectively, our results uncovered that mitophagy defects mediated the aging-associated markers in HGPS, highlighted the function of mitochondrial homeostasis in HGPS progression, and suggested mitophagy as an intervention target for HGPS and aging.

Senescence, regulators of alternative splicing and effects of trametinib treatment in progeroid syndromes

Progeroid syndromes such as Hutchinson Gilford Progeroid syndrome (HGPS), Werner syndrome (WS) and Cockayne syndrome (CS), result in severely reduced lifespans and premature ageing. Normal senescent cells show splicing factor dysregulation, which has not yet been investigated in syndromic senescent cells. We sought to investigate the senescence characteristics and splicing factor expression profiles of progeroid dermal fibroblasts. Natural cellular senescence can be reversed by application of the senomorphic drug, trametinib, so we also investigated its ability to reverse senescence characteristics in syndromic cells. We found that progeroid cultures had a higher senescence burden, but did not always have differences in levels of proliferation, DNA damage repair and apoptosis. Splicing factor gene expression appeared dysregulated across the three syndromes. 10 µM trametinib reduced senescent cell load and affected other aspects of the senescence phenotype (including splicing factor expression) in HGPS and Cockayne syndromes. Werner syndrome cells did not demonstrate changes in in senescence following treatment. Splicing factor dysregulation in progeroid cells provides further evidence to support this mechanism as a hallmark of cellular ageing and highlights the use of progeroid syndrome cells in the research of ageing and age-related disease. This study suggests that senomorphic drugs such as trametinib could be a useful adjunct to therapy for progeroid diseases.

Lonafarnib and everolimus reduce pathology in iPSC-derived tissue engineered blood vessel model of Hutchinson-Gilford Progeria Syndrome

Hutchinson-Gilford Progeria Syndrome (HGPS) is a rare, fatal genetic disease that accelerates atherosclerosis. With a limited pool of HGPS patients, clinical trials face unique challenges and require reliable preclinical testing. We previously reported a 3D tissue engineered blood vessel (TEBV) microphysiological system fabricated with iPSC-derived vascular cells from HGPS patients. HGPS TEBVs exhibit features of HGPS atherosclerosis including loss of smooth muscle cells, reduced vasoactivity, excess extracellular matrix (ECM) deposition, inflammatory marker expression, and calcification. We tested the effects of HGPS therapeutics Lonafarnib and Everolimus separately and together, currently in Phase I/II clinical trial, on HGPS TEBVs. Everolimus decreased reactive oxygen species levels, increased proliferation, reduced DNA damage in HGPS vascular cells, and improved vasoconstriction in HGPS TEBVs. Lonafarnib improved shear stress response of HGPS iPSC-derived endothelial cells (viECs) and reduced ECM deposition, inflammation, and calcification in HGPS TEBVs. Combination treatment with Lonafarnib and Everolimus produced additional benefits such as improved endothelial and smooth muscle marker expression and reduced apoptosis, as well as increased TEBV vasoconstriction and vasodilation. These results suggest that a combined trial of both drugs may provide cardiovascular benefits beyond Lonafarnib, if the Everolimus dose can be tolerated.

Unique progerin C-terminal peptide ameliorates Hutchinson-Gilford progeria syndrome phenotype by rescuing BUBR1

An accumulating body of evidence indicates an association between mitotic defects and the aging process in Hutchinson-Gilford progeria syndrome (HGPS), which is a premature aging disease caused by progerin accumulation. Here, we found that BUBR1, a core component of the spindle assembly checkpoint, was downregulated during HGPS cellular senescence. The remaining BUBR1 was anchored to the nuclear membrane by binding with the C terminus of progerin, thus further limiting the function of BUBR1. Based on this, we established a unique progerin C-terminal peptide (UPCP) that effectively blocked the binding of progerin and BUBR1 and enhanced the expression of BUBR1 by interfering with the interaction between PTBP1 and progerin. Finally, UPCP significantly inhibited HGPS cellular senescence and ameliorated progeroid phenotypes, extending the lifespan of Lmna^G609G/G609G mice. Our findings reveal an essential role for the progerin-PTBP1-BUBR1 axis in HGPS. Therapeutics designed around UPCP may be a beneficial strategy for HGPS treatment.

In vivo stress reporters as early biomarkers of the cellular changes associated with progeria

Age‐related diseases account for a high proportion of the total global burden of disease. Despite recent advances in understanding their molecular basis, there is a lack of suitable early biomarkers to test selected compounds and accelerate their translation to clinical trials. We have investigated the utility of in vivo stress reporter systems as surrogate early biomarkers of the degenerative disease progression. We hypothesized that cellular stress observed in models of human degenerative disease preceded overt cellular damage and at the same time will identify potential cytoprotective pathways. To test this hypothesis, we generated novel accelerated ageing (progeria) reporter mice by crossing the LmnaG609G mice into our oxidative stress/inflammation (Hmox1) and DNA damage (p21) stress reporter models. Histological analysis of reporter expression demonstrated a time‐dependent and tissue‐specific activation of the reporters in tissues directly associated with Progeria, including smooth muscle cells, the vasculature and gastrointestinal tract. Importantly, reporter expression was detected prior to any perceptible deleterious phenotype. Reporter expression can therefore be used as an early marker of progeria pathogenesis and to test therapeutic interventions. This work also demonstrates the potential to use stress reporter approaches to study and find new treatments for other degenerative diseases.

Ageing - Oxidative stress, PTMs and disease

Post-translational modifications (PTMs) have been proposed as a link between the oxidative stress-inflammation-ageing trinity, thereby affecting several hallmarks of ageing. Phosphorylation, acetylation, and ubiquitination cover >90% of all the reported PTMs. Several of the main PTMs are involved in normal "healthy" ageing and in different age-related diseases, for instance neurodegenerative, metabolic, cardiovascular, and bone diseases, as well as cancer and chronic kidney disease. Ultimately, data from human rare progeroid syndromes, but also from long-living animal species, imply that PTMs are critical regulators of the ageing process. Mechanistically, PTMs target epigenetic and non-epigenetic pathways during ageing. In particular, epigenetic histone modification has critical implications for the ageing process and can modulate lifespan. Therefore, PTM-based therapeutics appear to be attractive pharmaceutical candidates to reduce the burden of ageing-related diseases. Several phosphorylation and acetylation inhibitors have already been FDA-approved for the treatment of other diseases and offer a unique potential to investigate both beneficial effects and possible side-effects. As an example, the most well-studied senolytic compounds dasatinib and quercetin, which have already been tested in Phase 1 pilot studies, also act as kinase inhibitors, targeting cellular senescence and increasing lifespan. Future studies need to carefully determine the best PTM-based candidates for the treatment of the "diseasome of ageing".

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.

Need for NAD+: Focus on Striated Muscle Laminopathies

Laminopathies are a heterogeneous group of rare diseases caused by genetic mutations in the LMNA gene, encoding A-type lamins. A-type lamins are nuclear envelope proteins which associate with B-type lamins to form the nuclear lamina, a meshwork underlying the inner nuclear envelope of differentiated cells. The laminopathies include lipodystrophies, progeroid phenotypes and striated muscle diseases. Research on striated muscle laminopathies in the recent years has provided novel perspectives on the role of the nuclear lamina and has shed light on the pathological consequences of altered nuclear lamina. The role of altered nicotinamide adenine dinucleotide (NAD⁺) in the physiopathology of striated muscle laminopathies has been recently highlighted. Here, we have summarized these findings and reviewed the current knowledge about NAD⁺ alteration in striated muscle laminopathies, providing potential therapeutic approaches.

Progerin accelerates atherosclerosis by inducing endoplasmic reticulum stress in vascular smooth muscle cells

Hutchinson–Gilford progeria syndrome (HGPS) is a rare genetic disorder caused by progerin, a mutant lamin A variant. HGPS patients display accelerated aging and die prematurely, typically from atherosclerosis complications. Recently, we demonstrated that progerin‐driven vascular smooth muscle cell (VSMC) loss accelerates atherosclerosis leading to premature death in apolipoprotein E‐deficient mice. However, the molecular mechanism underlying this process remains unknown. Using a transcriptomic approach, we identify here endoplasmic reticulum stress (ER) and the unfolded protein responses as drivers of VSMC death in two mouse models of HGPS exhibiting ubiquitous and VSMC‐specific progerin expression. This stress pathway was also activated in HGPS patient‐derived cells. Targeting ER stress response with a chemical chaperone delayed medial VSMC loss and inhibited atherosclerosis in both progeria models, and extended lifespan in the VSMC‐specific model. Our results identify a mechanism underlying cardiovascular disease in HGPS that could be targeted in patients. Moreover, these findings may help to understand other vascular diseases associated with VSMC death, and provide insight into aging‐dependent vascular damage related to accumulation of unprocessed toxic forms of lamin A.

Identification of hub genes, key pathways, and therapeutic agents in Hutchinson-Gilford Progeria syndrome using bioinformatics analysis

BACKGROUND

Hutchinson-Gilford Progeria syndrome (HGPS) is a rare lethal premature and accelerated aging disease caused by mutations in the lamin A/C gene. Nevertheless, the mechanisms of cellular damage, senescence, and accelerated aging in HGPS are not fully understood. Therefore, we aimed to screen potential key genes, pathways, and therapeutic agents of HGPS by using bioinformatics methods in this study.

METHODS

The gene expression profile of GSE113648 and GSE41751 were retrieved from the gene expression omnibus database and analyzed to identify the differentially expressed genes (DEGs) between HGPS and normal controls. Then, gene ontology and the Kyoto encyclopedia of genes and genomes pathway enrichment analysis were carried out. To construct the protein-protein interaction (PPI) network, we used STRING and Cytoscape to make module analysis of these DEGs. Besides, the connectivity map (cMAP) tool was used as well to predict potential drugs.

RESULTS

As a result, 180 upregulated DEGs and 345 downregulated DEGs were identified, which were significantly enriched in pathways in cancer and PI3K-Akt signaling pathway. The top centrality hub genes fibroblast growth factor 2, decorin, matrix metallopeptidase2, and Fos proto-oncogene, AP-1 transcription factor subunit were screened out as the critical genes among the DEGs from the PPI network. Dexibuprofen and parthenolide were predicted to be the possible agents for the treatment of HGPS by cMAP analysis.

CONCLUSION

This study identified key genes, signal pathways and therapeutic agents, which might help us improve our understanding of the mechanisms of HGPS and identify some new therapeutic agents for HGPS.

Accumulation of Progerin Affects the Symmetry of Cell Division and Is Associated with Impaired Wnt Signaling and the Mislocalization of Nuclear Envelope Proteins

Hutchinson-Gilford progeria syndrome (HGPS) is the result of a defective form of the lamin A protein called progerin. While progerin is known to disrupt the properties of the nuclear lamina, the underlying mechanisms responsible for the pathophysiology of HGPS remain less clear. Previous studies in our laboratory have shown that progerin expression in murine epidermal basal cells results in impaired stratification and halted development of the skin. Stratification and differentiation of the epidermis is regulated by asymmetric stem cell division. Here, we show that expression of progerin impairs the ability of stem cells to maintain tissue homeostasis as a result of altered cell division. Quantification of basal skin cells showed an increase in symmetric cell division that correlated with progerin accumulation in HGPS mice. Investigation of the mechanisms underlying this phenomenon revealed a putative role of Wnt/β-catenin signaling. Further analysis suggested an alteration in the nuclear translocation of β-catenin involving the inner and outer nuclear membrane proteins, emerin and nesprin-2. Taken together, our results suggest a direct involvement of progerin in the transmission of Wnt signaling and normal stem cell division. These insights into the molecular mechanisms of progerin may help develop new treatment strategies for HGPS.

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.

NRF2 and the Hallmarks of Cancer

The transcription factor NRF2 is the master regulator of the cellular antioxidant response. Though recognized originally as a target of chemopreventive compounds that help prevent cancer and other maladies, accumulating evidence has established the NRF2 pathway as a driver of cancer progression, metastasis, and resistance to therapy. Recent studies have identified new functions for NRF2 in the regulation of metabolism and other essential cellular functions, establishing NRF2 as a truly pleiotropic transcription factor. In this review, we explore the roles of NRF2 in the hallmarks of cancer, indicating both tumor suppressive and tumor-promoting effects.

Association of Lonafarnib Treatment vs No Treatment With Mortality Rate in Patients With Hutchinson-Gilford Progeria Syndrome

IMPORTANCE

Hutchinson-Gilford progeria syndrome (HGPS) is an extremely rare fatal premature aging disease. There is no approved treatment.

OBJECTIVE

To evaluate the association of monotherapy using the protein farnesyltransferase inhibitor lonafarnib with mortality rate in children with HGPS.

DESIGN, SETTING, AND PARTICIPANTS

Cohort study comparing contemporaneous (birth date ≥1991) untreated patients with HGPS matched with treated patients by age, sex, and continent of residency using conditional Cox proportional hazards regression. Treatment cohorts included patients from 2 single-group, single-site clinical trials (ProLon1 [n = 27; completed] and ProLon2 [n = 36; ongoing]). Untreated patients originated from a separate natural history study (n = 103). The cutoff date for patient follow-up was January 1, 2018.

EXPOSURE

Treated patients received oral lonafarnib (150 mg/m2) twice daily. Untreated patients received no clinical trial medications.

MAIN OUTCOMES AND MEASURES

The primary outcome was mortality. The primary analysis compared treated patients from the first lonafarnib trial with matched untreated patients. A secondary analysis compared the combined cohorts from both lonafarnib trials with matched untreated patients.

RESULTS

Among untreated and treated patients (n = 258) from 6 continents, 123 (47.7%) were female; 141 (54.7%) had a known genotype, of which 125 (88.7%) were classic (c.1824C>T in LMNA). When identified (n = 73), the primary cause of death was heart failure (79.4%). The median treatment duration was 2.2 years. Median age at start of follow-up was 8.4 (interquartile range [IQR], 4.8-9.5) years in the first trial cohort and 6.5 (IQR, 3.7-9.0) years in the combined cohort. There was 1 death (3.7%) among 27 patients in the first trial group and there were 9 deaths (33.3%) among 27 patients in the matched untreated group. Treatment was associated with a lower mortality rate (hazard ratio, 0.12; 95% CI, 0.01-0.93; P = .04). In the combined cohort, there were 4 deaths (6.3%) among 63 patients in the treated group and 17 deaths (27.0%) among 63 patients in the matched untreated group (hazard ratio, 0.23; 95% CI, 0.06-0.90; P = .04).

CONCLUSIONS AND RELEVANCE

Among patients with HGPS, lonafarnib monotherapy, compared with no treatment, was associated with a lower mortality rate after 2.2 years of follow-up. Study interpretation is limited by its observational design.