Cardiovascular pathology in Hutchinson-Gilford progeria: correlation with the vascular pathology of aging

Nuclear envelope components in vascular mechanotransduction: emerging roles in vascular health and disease

The vascular network, uniquely sensitive to mechanical changes, translates biophysical forces into biochemical signals for vessel function. This process relies on the cell's architectural integrity, enabling uniform responses to physical stimuli. Recently, the nuclear envelope (NE) has emerged as a key regulator of vascular cell function. Studies implicate nucleoskeletal elements (e.g. nuclear lamina) and the linker of nucleoskeleton and cytoskeleton (LINC) complex in force transmission, emphasizing nucleo-cytoskeletal communication in mechanotransduction. The nuclear pore complex (NPC) and its component proteins (i.e. nucleoporins) also play roles in cardiovascular disease (CVD) progression. We herein summarize evidence on the roles of nuclear lamina proteins, LINC complex members, and nucleoporins in endothelial and vascular cell mechanotransduction. Numerous studies attribute NE components in cytoskeletal-related cellular behaviors to insinuate dysregulation of nucleocytoskeletal feedback and nucleocytoplasmic transport as a mechanism of endothelial and vascular dysfunction, and hence implications for aging and vascular pathophysiology.

Cardiac phenotypes in LMNA mutations

PURPOSE OF REVIEW

This review highlights the diverse cardiac manifestations of LMNA mutations, focusing on their underlying molecular mechanisms and clinical implications. As LMNA mutations are implicated in cardiomyopathies, such as dilated cardiomyopathy (DCM), arrhythmogenic cardiomyopathy (ARVC), and conduction system diseases, understanding these phenotypes is critical for advancing diagnosis and management strategies.

RECENT FINDINGS

Recent studies reveal that LMNA mutations disrupt nuclear envelope stability, activating the DNA damage response (DDR) and compromising chromatin organization and mechanotransduction. Mouse models have elucidated pathways linking LMNA dysfunction to fibrosis, arrhythmias, and myocardial remodeling. Emerging evidence demonstrates that fibroblasts play a crucial role in cardiac phenotypes. Advances in genetic screening have also underscored the importance of early identification and risk stratification, particularly for arrhythmias and sudden cardiac death.

SUMMARY

The diverse spectrum of LMNA-related cardiac phenotypes, from isolated conduction defects to severe DCM and ARVC, underscores the necessity of personalized care strategies. Bridging insights from molecular studies and clinical research paves the way for targeted therapies to slow disease progression and improve patient outcomes. Future efforts should prioritize translational research on molecular mechanisms with potential in mouse models, alongside a deeper exploration of genotype-phenotype correlations, to refine and implement effective therapeutic interventions.

Insights from autopsy-initiated pathological studies of the pathogenesis and clinical manifestations of atherosclerosis and ischemic heart disease: Part I. Atherosclerosis

CONTEXT

Ischemic heart disease (IHD) due to coronary atherosclerosis constitutes the leading cause of morbidity and mortality worldwide. This review was undertaken to document the historical basis for our contemporary understanding of atherosclerosis-based disease and to provide a rationale for continued support for autopsy-based research to make further progress in reducing the morbidity and mortality from atherosclerosis-related disease.

OBJECTIVES

To analyze the contributions of the autopsy-initiated pathological studies to complement and validate other lines of investigation in determining the pathology and pathogenesis of the leading worldwide cause of morbidity and mortality, namely, atherosclerosis and its major complications of coronary atherosclerosis, ischemic heart disease, coronary thrombosis, acute myocardial infarction, and sudden cardiac death.

DATA SOURCES

Systematic search on PubMed to gather relevant studies concerning autopsy studies and reviews of the pathology and pathogenesis of atherosclerosis, ischemic heart disease, coronary atherosclerosis, coronary thrombosis, myocardial infarction, and sudden cardiac death CONCLUSIONS: Extensive published reports have confirmed the continuing importance of the autopsy as a powerful tool to understand the pathogenesis, clinical features, and therapeutic options for major diseases. This specifically has been shown by the analysis of atherosclerosis and its major manifestation of ischemic heart disease, as presented in this (Part I) and its companion (Part II) review. Autopsy-initiated pathological studies have documented the prevalence and natural history of atherosclerosis in different human populations in relationship to the prevalence of risk factors and established that the clinically silent phase of the disease begins in the first decades of life. Insights from these studies have been essential in developing and evaluating strategies for continued progress in preventing and controlling the disability and death associated with atherosclerotic heart disease.

Impacts of Radiation on Metabolism and Vascular Cell Senescence

Significance: This review investigates how radiation therapy (RT) increases the risk of delayed cardiovascular disease (CVD) in cancer survivors. Understanding the mechanisms underlying radiation-induced CVD is essential for developing targeted therapies to mitigate these effects and improve long-term outcomes for patients with cancer. Recent Advances: Recent studies have primarily focused on metabolic alterations induced by irradiation in various cancer cell types. However, there remains a significant knowledge gap regarding the role of chronic metabolic alterations in normal cells, particularly vascular cells, in the progression of CVD after RT. Critical Issues: This review centers on RT-induced metabolic alterations in vascular cells and their contribution to senescence accumulation and chronic inflammation across the vasculature post-RT. We discuss key metabolic pathways, including glycolysis, the tricarboxylic acid cycle, lipid metabolism, glutamine metabolism, and redox metabolism (nicotinamide adenine dinucleotide/Nicotinamide adenine dinucleotide (NADH) and nicotinamide adenine dinucleotide phosphate (NADP+)/NADPH). We further explore the roles of regulatory proteins such as p53, adenosine monophosphate-activated protein kinase, and mammalian target of rapamycin in driving these metabolic dysregulations. The review emphasizes the impact of immune-vascular crosstalk mediated by the senescence-associated secretory phenotype, which perpetuates metabolic dysfunction, enhances chronic inflammation, drives senescence accumulation, and causes vascular damage, ultimately contributing to cardiovascular pathogenesis. Future Directions: Future research should prioritize identifying therapeutic targets within these metabolic pathways or the immune-vascular interactions influenced by RT. Correcting metabolic dysfunction and reducing chronic inflammation through targeted therapies could significantly improve cardiovascular outcomes in cancer survivors. Antioxid. Redox Signal. 00, 000-000.

Vascular cell types in progeria: victims or villains?

Hutchinson-Gilford progeria syndrome (HGPS) is an ultrarare genetic disease caused by progerin, a broadly expressed mutant variant of lamin A protein that accelerates aging and leads to premature death typically in adolescence. Progerin affects many organs and reproduces many characteristics of physiological aging, with the main cause of death in HGPS being atherosclerotic cardiovascular disease (CVD). Due to the rarity of HGPS, advances in understanding the disease and progress toward new therapeutic approaches are crucially dependent on preclinical models. We discuss recent research developments from a variety of HGPS experimental systems, with a special focus on in vivo studies of the role of vascular smooth muscle cells (VSMCs) and endothelial cells (ECs) that are key players in atherosclerosis.

Intracranial hypertension in a patient with Hutchinson-Gilford progeria syndrome

Hutchinson-Gilford syndrome, also known as progeria, is a rare genetic disorder that causes premature and accelerated ageing from the neonatal period. The disease is caused by de novo mutations in the LMNA gene. Patients present with a range of symptoms, including skin, bone, joint and cardiac disorders, as well as characteristic facial dysmorphia. Intracranial hypertension is not a known symptom of this disease. To the best of our knowledge, no case of a patient with Hutchinson-Gilford syndrome presenting with intracranial hypertension without a traumatic context has been reported in the literature to date. This report presents the case of a child diagnosed with Hutchinson-Gilford syndrome who presented with intracranial hypertension at the age of three years, with no secondary cause identified. Long-term treatment with acetazolamide was required to control the intracranial hypertension. We hypothesise that the intracranial hypertension may be related to vascular abnormalities observed in Hutchinson-Gilford syndrome, which may cause a venous drainage dysfunction. To support the hypothesis of a non-random association between intracranial hypertension and Hutchinson-Gilford syndrome, further reports of similar cases in children with the syndrome are required.

Adenine base editing rescues pathogenic phenotypes in tissue engineered vascular model of Hutchinson-Gilford progeria syndrome

The rare, accelerated aging disease Hutchinson-Gilford Progeria Syndrome (HGPS) is commonly caused by a de novo c.1824 C > T point mutation of the LMNA gene that results in the protein progerin. The primary cause of death is a heart attack or stroke arising from atherosclerosis. A characteristic feature of HGPS arteries is loss of smooth muscle cells. An adenine base editor (ABE7.10max) corrected the point mutation and produced significant improvement in HGPS mouse lifespan, vascular smooth muscle cell density, and adventitial fibrosis. To assess whether base editing correction of human HGPS tissue engineered blood vessels (TEBVs) prevents the HGPS vascular phenotype and to identify the minimum fraction of edited smooth muscle cells needed to effect such changes, we transduced HGPS iPSCs with lentivirus containing ABE7.10max. Endothelial cells (viECs) and smooth muscle cells (viSMCs) obtained by differentiation of edited HGPS iPSCs did not express progerin and had double-stranded DNA breaks and reactive oxygen species at the same levels as healthy viSMCs and viECs. Editing HGPSviECs restored a normal response to shear stress. Normal vasodilation and viSMC density were restored in TEBVs made with edited cells. When TEBVs were prepared with at least 50% edited smooth muscle cells, viSMC proliferation and myosin heavy chain levels significantly improved. Sequencing of TEBV cells after perfusion indicated an enrichment of edited cells after 5 weeks of perfusion when they comprised 50% of the initial number of cells in the TEBVs. Thus, base editing correction of a fraction of HGPS vascular cells improves human TEBV phenotype.

Progerin mRNA Is Associated with Smoking and Signs of Increased Microvascular Damage in Patients with Diabetic Macular Edema

The premature aging disease Hutchinson-Gilford Syndrome (HGPS) is caused by defined mutations in the LMNA gene, resulting in the activation of a cryptic splice donor site, which leads to a defective truncated prelamin A protein called progerin. Notably, progerin expression has also been detected in non-mutated healthy individuals, and therefore, its involvement in the physiological aging process has been widely discussed. Since diabetes mellitus is associated with premature aging and increased cardiovascular mortality, we aimed to investigate the role of progerin expression in patients with diabetic retinopathy (DR). mRNA expression of progerin was analyzed in blood samples from 140 patients with DR who received anti-vascular endothelial growth factor (VEGF) therapy. Progerin mRNA levels were significantly lower in female compared to male patients (n = 42 vs. n = 98; 0.67 ± 0.19 vs. 0.89 ± 0.51, p = 0.006) and higher in patients with non-proliferative (NP)DR (n = 87 vs. n = 53; 0.9 ± 0.51 vs. 0.71 ± 0.29, p = 0.013) compared to those with proliferative (P)DR. Additionally, a positive correlation was found between progerin mRNA expression and the number of intravitreal anti-VEGF applications (n = 139, r = 0.21, p = 0.015), central macula thickness (CMT), (n = 137, r = 0.18, p = 0.036) and nicotine consumption (n = 105, r = 0.235, p = 0.002). The nuclear localization and significant upregulation of progerin mRNA and protein levels in dermal fibroblasts from HGPS donors emphasize its role in cellular aging mechanisms. Progerin mRNA levels were higher in patients with NPDR. CMT, number of intravitreal anti-VEGF therapy treatments, and cigarette consumption were positively related to progerin mRNA, suggesting an association with disease progression and premature aging.

J, Draganova L, Anderson G, Jonnalagadda US, Hayward R, Shroff R, Wen WTL, Verhulst A, Foo RSY, Shanahan CM. Mineral Stress Drives Loss of Heterochromatin: An Early Harbinger of Vascular Inflammaging and Calcification

BACKGROUND

Vascular calcification is a detrimental aging pathology markedly accelerated in patients with chronic kidney disease. PLA (prelamin A) is a biomarker of vascular smooth muscle cell aging that accelerates calcification however the mechanisms remain undefined.

METHODS

Vascular smooth muscle cells were transduced with PLA using an adenoviral vector and epigenetic modifications were monitored using immunofluorescence and targeted polymerase chain reaction array. Epigenetic findings were verified in vivo using immunohistochemistry in human vessels, in a mouse model of inducible prelamin A expression, and in a rat model of chronic kidney disease-induced calcification. Transcriptomic and chromatin immunoprecipitation followed by sequencing analyses were used to identify gene targets impacted by changes in the epigenetic landscape. Molecular tools and antibody arrays were used to monitor the effects of mineral dysregulation on heterochromatin, inflammation, aging, and calcification.

RESULTS

Here, we report that depletion of the repressive heterochromatin marks, H3K9me3 (histone H3, lysine 9, trimethylation) and H3K27me3 (histone H3, lysine 27,trimethylation), is an early hallmark of vascular aging induced by both nuclear lamina dysfunction and dysregulated mineral metabolism, which act to modulate the expression of key epigenetic writers and erasers. Global analysis of H3K9me3 and H3K27me3 marks and pathway analysis revealed deregulation of insulin signaling and autophagy pathways as well as cross-talking DNA damage and NF-κB (nuclear factor κB) inflammatory pathways consistent with early activation of the senescence-associated secretory phenotype. Expression of PLA in vivo induced loss of heterochromatin and promoted inflammation and osteogenic differentiation which preceded aging indices, such as DNA damage and senescence. Vessels from children on dialysis and rats with chronic kidney disease showed prelamin A accumulation and accelerated loss of heterochromatin before the onset of calcification.

CONCLUSIONS

Dysregulated mineral metabolism drives changes in the epigenetic landscape and nuclear lamina dysfunction that together promote early induction of inflammaging pathways priming the vasculature for downstream pathological change.

Angiopoietin-2 reverses endothelial cell dysfunction in progeria vasculature

Hutchinson-Gilford progeria syndrome (HGPS) is a rare premature aging disorder in children caused by a point mutation in the lamin A gene, resulting in a toxic form of lamin A called progerin. Accelerated atherosclerosis leading to heart attack and stroke are the major causes of death in these patients. Endothelial cell (EC) dysfunction contributes to the pathogenesis of HGPS related cardiovascular diseases (CVD). Endothelial cell-cell communications are important in the development of the vasculature, and their disruptions contribute to cardiovascular pathology. However, it is unclear how progerin interferes with such communications that lead to vascular dysfunction. An antibody array screening of healthy and HGPS patient EC secretomes identified Angiopoietin-2 (Ang2) as a down-regulated signaling molecule in HGPS ECs. A similar down-regulation of Ang2 mRNA and protein was detected in the aortas from an HGPS mouse model. Addition of Ang2 to HGPS ECs rescues vasculogenesis, normalizes endothelial cell migration and gene expression, and restores nitric oxide bioavailability through eNOS activation. Furthermore, Ang2 addition reverses unfavorable paracrine effects of HGPS ECs on vascular smooth muscle cells. Lastly, by utilizing adenine base editor (ABE)-corrected HGPS ECs and progerin-expressing HUVECs, we demonstrated a negative correlation between progerin and Ang2 expression. Lastly, our results indicated that Ang2 exerts its beneficial effect in ECs through Tie2 receptor binding, activating an Akt-mediated pathway. Together, these results provide molecular insights into EC dysfunction in HGPS and suggest that Ang2 treatment has potential therapeutic effects in HGPS-related CVD.

Endothelial cell-specific progerin expression does not cause cardiovascular alterations and premature death

Hutchinson-Gilford progeria syndrome (HGPS) is a rare genetic disorder caused by a mutation in the LMNA gene that provokes the synthesis of progerin, a mutant version of the nuclear protein lamin A that accelerates aging and precipitates death. The most clinically relevant feature of HGPS is the development of cardiac anomalies and severe vascular alterations, including massive loss of vascular smooth muscle cells, increased fibrosis, and generalized atherosclerosis. However, it is unclear if progerin expression in endothelial cells (ECs) causes the cardiovascular manifestations of HGPS. To tackle this question, we generated atherosclerosis-free mice (LmnaLCS/LCSCdh5-CreERT2) and atheroprone mice (Apoe-/-LmnaLCS/LCSCdh5-CreERT2) with EC-specific progerin expression. Like progerin-free controls, LmnaLCS/LCSCdh5-CreERT2 mice did not develop heart fibrosis or cardiac electrical and functional alterations, and had normal vascular structure, body weight, and lifespan. Similarly, atheroprone Apoe-/-LmnaLCS/LCSCdh5-CreERT2 mice showed no alteration in body weight or lifespan versus Apoe-/-LmnaLCS/LCS controls and did not develop vascular alterations or aggravated atherosclerosis. Our results indicate that progerin expression in ECs is not sufficient to cause the cardiovascular phenotype and premature death associated with progeria.

LMNA-related cardiomyopathy: From molecular pathology to cardiac gene therapy

BACKGROUND

The genetic variants of LMNA cause an array of diseases that often affect the heart. LMNA-related cardiomyopathy exhibits high-penetrance and early-onset phenotypes that lead to late-stage heart failure or lethal arrhythmia. As a subtype of dilated cardiomyopathy and arrhythmogenic cardiomyopathy, LMNA-related cardiac dysfunction is resistant to existing cardiac therapeutic strategies, leaving a major unmet clinical need in cardiomyopathy management.

AIM OF REVIEW

Here we comprehensively summarize current knowledge about the genetic basis, disease models and pathological mechanisms of LMNA-related cardiomyopathy. Recent translational studies were highlighted to indicate new therapeutic modalities such as gene supplementation, gene silencing and genome editing therapy, which offer potential opportunities to overcome the difficulties in the development of specific drugs for this disease.

KEY SCIENTIFIC CONCEPTS OF REVIEW

LMNA-related cardiomyopathy involves many diverse disease mechanisms that preclude small-molecule drugs that target only a small fraction of the mechanisms. Agreeing to this notion, the first-in-human clinical trial for this disease recently reported futility. By contrast, gene therapy offers the new hope to directly intervene LMNA variants and demonstrates a tremendous potential for breakthrough therapy for this disease. Concepts in this review are also applicable to studies of other genetic diseases that lack effective therapeutics.

A Review of Telomere Attrition in Cancer and Aging: Current Molecular Insights and Future Therapeutic Approaches

BACKGROUND/OBJECTIVES

As cells divide, telomeres shorten through a phenomenon known as telomere attrition, which leads to unavoidable senescence of cells. Unprotected DNA exponentially increases the odds of mutations, which can evolve into premature aging disorders and tumorigenesis. There has been growing academic and clinical interest in exploring this duality and developing optimal therapeutic strategies to combat telomere attrition in aging and cellular immortality in cancer. The purpose of this review is to provide an updated overview of telomere biology and therapeutic tactics to address aging and cancer.

METHODS

We used the Rayyan platform to review the PubMed database and examined the ClinicalTrial.gov registry to gain insight into clinical trials and their results.

RESULTS

Cancer cells activate telomerase or utilize alternative lengthening of telomeres to escape telomere shortening, leading to near immortality. Contrarily, normal cells experience telomeric erosion, contributing to premature aging disorders, such as Werner syndrome and Hutchinson-Gilford Progeria, and (2) aging-related diseases, such as neurodegenerative and cardiovascular diseases.

CONCLUSIONS

The literature presents several promising therapeutic approaches to potentially balance telomere maintenance in aging and shortening in cancer. This review highlights gaps in knowledge and points to the potential of these optimal interventions in preclinical and clinical studies to inform future research in cancer and aging.

Angiopoietin-2: A Therapeutic Target for Vascular Protection in Hutchinson-Gilford Progeria Syndrome

Hutchinson-Gilford progeria syndrome (HGPS) is a pediatric condition characterized by clinical features that resemble accelerated aging. The abnormal accumulation of a toxic form of the lamin A protein known as progerin disrupts cellular functions, leading to various complications, including growth retardation, loss of subcutaneous fat, abnormal skin, alopecia, osteoporosis, and progressive joint contractures. Death primarily occurs as the result of complications from progressive atherosclerosis, especially from cardiac disease, such as myocardial infarction or heart failure, or cerebrovascular disease like stroke. Despite the availability of lonafarnib, the only US Food and Drug Administration-approved treatment for HGPS, cardiovascular complications remain the leading cause of morbidity and mortality in affected patients. Defective angiogenesis-the process of forming new blood vessels from existing ones-plays a crucial role in the development of cardiovascular disease. A recent study suggests that Angiopoietin-2 (Ang2), a pro-angiogenic growth factor that regulates angiogenesis and vascular stability, may offer therapeutic potential for the treatment of HGPS. In this review, we describe the clinical features and key cellular processes impacted by progerin and discuss the therapeutic potential of Ang2 in addressing these challenges.

3D confinement alters smooth muscle cell responses to chemical and mechanical cues

Smooth muscle cell (SMC) phenotypic switching is a hallmark of many vascular diseases. Although prior work has established that chemical and mechanical cues contribute to SMC phenotypic switching, the impact of three-dimensional (3D) confinement on this process remains elusive. Yet, in vivo, arterial SMCs reside within confined environments. In this study, we designed a microfluidic assay to investigate the interplay between 3D confinement and different environmental stimuli in SMC function. Our results show that tightly, but not moderately, confined SMCs acquire a contractile phenotype when exposed to collagen I. Elevated compressive forces induced by hydrostatic pressure abolish this upregulation of the contractile phenotype and compromise SMC survival, particularly in tightly confined spaces. Transforming growth factor beta 1, which promotes the contractile state in moderate confinement, fails to enhance the contractility of tightly confined cells. Fibronectin and engagement of cadherin 2 suppress the contractile phenotype of SMCs regardless of the degree of confinement. In contrast, homophilic engagement of cadherin 11 upregulates SMC-specific genes and enhances contractility in both moderately and tightly confined cells. Overall, our work introduces 3D confinement as a regulator of SMC phenotypic responses to chemical and mechanical signals.

Endothelial-to-Mesenchymal Transition Contributes to Accelerated Atherosclerosis in Hutchinson-Gilford Progeria Syndrome

BACKGROUND

Atherosclerosis is the main medical problem in Hutchinson-Gilford progeria syndrome, a rare premature aging disorder caused by the mutant lamin-A protein progerin. Recently, we found that limiting progerin expression to vascular smooth muscle cells (VSMCs) is sufficient to hasten atherosclerosis and death in Apoe-deficient mice. However, the impact of progerin-driven VSMC defects on endothelial cells (ECs) remained unclear.

METHODS

Apoe- or Ldlr-deficient C57BL/6J mice with ubiquitous, VSMC-, EC- or myeloid-specific progerin expression fed a normal or high-fat diet were used to study endothelial phenotype during Hutchinson-Gilford progeria syndrome-associated atherosclerosis. Endothelial permeability to low-density lipoproteins was assessed by intravenous injection of fluorescently labeled human low-density lipoprotein and confocal microscopy analysis of the aorta. Leukocyte recruitment to the aortic wall was evaluated by en face immunofluorescence. Endothelial-to-mesenchymal transition (EndMT) was assessed by quantitative polymerase chain reaction and RNA sequencing in the aortic intima and by immunofluorescence in aortic root sections. TGFβ (transforming growth factor β) signaling was analyzed by multiplex immunoassay in serum, by Western blot in the aorta, and by immunofluorescence in aortic root sections. The therapeutic benefit of TGFβ1/SMAD3 pathway inhibition was evaluated in mice by intraperitoneal injection of SIS3 (specific inhibitor of SMAD3), and vascular phenotype was assessed by Oil Red O staining, histology, and immunofluorescence in the aorta and the aortic root.

RESULTS

Both ubiquitous and VSMC-specific progerin expression in Apoe-null mice provoked alterations in aortic ECs, including increased permeability to low-density lipoprotein and leukocyte recruitment. Atherosclerotic lesions in these progeroid mouse models, but not in EC- and myeloid-specific progeria models, contained abundant cells combining endothelial and mesenchymal features, indicating extensive EndMT triggered by dysfunctional VSMCs. Accordingly, the intima of ubiquitous and VSMC-specific progeroid models at the onset of atherosclerosis presented increased expression of EndMT-linked genes, especially those specific to fibroblasts and extracellular matrix. Aorta in both models showed activation of the TGFβ1/SMAD3 pathway, a major trigger of EndMT, and treatment of VSMC-specific progeroid mice with SIS3 alleviated the aortic phenotype.

CONCLUSIONS

Progerin-induced VSMC alterations promote EC dysfunction and EndMT through TGFβ1/SMAD3, identifying this process as a candidate target for Hutchinson-Gilford progeria syndrome treatment. These findings also provide insight into the complex role of EndMT during atherogenesis.

Epigenetic regulation of cardiovascular diseases induced by behavioral and environmental risk factors: Mechanistic, diagnostic, and therapeutic insights

Behavioral and environmental risk factors are critical in the development and progression of cardiovascular disease (CVD). Understanding the molecular mechanisms underlying these risk factors will offer valuable insights for targeted preventive and therapeutic strategies. Epigenetic modifications, including DNA methylation, histone modifications, chromatin remodeling, noncoding RNA (ncRNA) expression, and epitranscriptomic modifications, have emerged as key mediators connecting behavioral and environmental risk factors to CVD risk and progression. These epigenetic alterations can profoundly impact on cardiovascular health and susceptibility to CVD by influencing cellular processes, development, and disease risk over an individual's lifetime and potentially across generations. This review examines how behavioral and environmental risk factors affect CVD risk and health outcomes through epigenetic regulation. We review the epigenetic effects of major behavioral risk factors (such as smoking, alcohol consumption, physical inactivity, unhealthy diet, and obesity) and environmental risk factors (including air and noise pollution) in the context of CVD pathogenesis. Additionally, we explore epigenetic biomarkers, considering their role as causal or surrogate indicators, and discuss epigenetic therapeutics targeting the mechanisms through which these risk factors contribute to CVD. We also address future research directions and challenges in leveraging epigenetic insights to reduce the burden of CVD related to behavioral and environmental factors and improve public health outcomes. This review aims to provide a comprehensive understanding of behavioral and environmental epigenetics in CVD and offer valuable strategies for therapeutic intervention.

Validation of metaxin-2 deficient C. elegans as a model for MandibuloAcral Dysplasia associated to mtx-2 (MADaM) syndrome

MandibuloAcral Dysplasia associated to MTX2 gene (MADaM) is a recently described progeroid syndrome (accelerated aging disease) whose clinical manifestations include skin abnormalities, growth retardation, and cardiovascular diseases. We previously proposed that mtx-2-deficient C. elegans could be used as a model for MADaM and to support this, we present here our comprehensive phenotypic characterization of these worms using atomic force microscopy (AFM), transcriptomic, and oxygen consumption rate analyses. AFM analysis showed that young mtx-2-less worms had a significantly rougher, less elastic cuticle which becomes significantly rougher and less elastic as they age, and abnormal mitochondrial morphology. mtx-2 C. elegans displayed slightly delayed development, decreased pharyngeal pumping, significantly reduced mitochondrial respiratory capacities, and transcriptomic analysis identified perturbations in the aging, TOR, and WNT-signaling pathways. The phenotypic characteristics of mtx-2 worms shown here are analogous to many of the human clinical presentations of MADaM and we believe this validates their use as a model which will allow us to uncover the molecular details of the disease and develop new therapeutics and treatments.

The syntaxin-binding protein STXBP5 regulates progerin expression

Hutchinson-Gilfor progeria syndrome (HGPS) is caused by a mutation in Lamin A resulting in the production of a protein called progerin. The accumulation of progerin induces inflammation, cellular senescence and activation of the P53 pathway. In this study, through public dataset analysis, we identified Syntaxin Binding Protein 5 (STXBP5) as an influencing factor of progerin expression. STXBP5 overexpression accelerated the onset of senescence, while STXBP5 deletion suppressed progerin expression, delayed senility, and decreased the expression of senescence-related factors. STXBP5 and progerin have synergistic effects and a protein-protein interaction. Through bioinformatics analysis, we found that STXBP5 affects ageing-related signalling pathways such as the mitogen-activated protein kinase (MAPK) pathway, the hippo pathway and the interleukin 17 (IL17) signalling pathway in progerin-expressing cells. In addition, STXBP5 overexpression induced changes in transposable elements (TEs), such as the human endogenous retrovirus H internal coding sequence (HERVH-int) changes. Our protein coimmunoprecipitation (Co-IP) results indicated that STXBP5 bound directly to progerin. Therefore, decreasing STXBP5 expression is a potential new therapeutic strategy for treating ageing-related phenotypes in patients with HGPS.

Inhibition of poly(ADP-Ribosyl)ation reduced vascular smooth muscle cells loss and improves aortic disease in a mouse model of human accelerated aging syndrome

Hutchinson-Gilford progeria syndrome (HGPS) is an extremely rare genetic disorder associated with features of accelerated aging. HGPS is an autosomal dominant disease caused by a de novo mutation of LMNA gene, encoding A-type lamins, resulting in the truncated form of pre-lamin A called progerin. While asymptomatic at birth, patients develop symptoms within the first year of life when they begin to display accelerated aging and suffer from growth retardation, and severe cardiovascular complications including loss of vascular smooth muscle cells (VSMCs). Recent works reported the loss of VSMCs as a major factor triggering atherosclerosis in HGPS. Here, we investigated the mechanisms by which progerin expression leads to massive VSMCs loss. Using aorta tissue and primary cultures of murine VSMCs from a mouse model of HGPS, we showed increased VSMCs death associated with increased poly(ADP-Ribosyl)ation. Poly(ADP-Ribosyl)ation is recognized as a post-translational protein modification that coordinates the repair at DNA damage sites. Poly-ADP-ribose polymerase (PARP) catalyzes protein poly(ADP-Ribosyl)ation by utilizing nicotinamide adenine dinucleotide (NAD+). Our results provided the first demonstration linking progerin accumulation, augmented poly(ADP-Ribosyl)ation and decreased nicotinamide adenine dinucleotide (NAD+) level in VSMCs. Using high-throughput screening on VSMCs differentiated from iPSCs from HGPS patients, we identified a new compound, trifluridine able to increase NAD+ levels through decrease of PARP-1 activity. Lastly, we demonstrate that trifluridine treatment in vivo was able to alleviate aortic VSMCs loss and clinical sign of progeria, suggesting a novel therapeutic approach of cardiovascular disease in progeria.

Endothelial YAP/TAZ activation promotes atherosclerosis in a mouse model of Hutchinson-Gilford progeria syndrome

Hutchinson-Gilford progeria syndrome (HGPS) is an extremely rare disease caused by the expression of progerin, an aberrant protein produced by a point mutation in the LMNA gene. HGPS patients show accelerated aging and die prematurely mainly from complications of atherosclerosis such as myocardial infarction, heart failure, or stroke. However, the mechanisms underlying HGPS vascular pathology remain ill-defined. We used single-cell RNA sequencing to characterize the aorta in progerin-expressing LmnaG609G/G609G mice and wild-type controls, with a special focus on endothelial cells (ECs). HGPS ECs showed gene expression changes associated with extracellular matrix alterations, increased leukocyte extravasation, and activation of the yes-associated protein 1/transcriptional activator with PDZ-binding domain (YAP/TAZ) mechanosensing pathway, all validated by different techniques. Atomic force microscopy experiments demonstrated stiffer subendothelial extracellular matrix in progeroid aortae, and ultrasound assessment of live HGPS mice revealed disturbed aortic blood flow, both key inducers of the YAP/TAZ pathway in ECs. YAP/TAZ inhibition with verteporfin reduced leukocyte accumulation in the aortic intimal layer and decreased atherosclerosis burden in progeroid mice. Our findings identify endothelial YAP/TAZ signaling as a key mechanism of HGPS vascular disease and open a new avenue for the development of YAP/TAZ-targeting drugs to ameliorate progerin-induced atherosclerosis.

Cardiac and skeletal muscle manifestations in the G608G mouse model of Hutchinson-Gilford progeria syndrome

Hutchinson-Gilford progeria syndrome (HGPS) is a rare premature aging disorder resulting from de novo mutations in the lamin A gene. Children with HGPS typically pass away in their teenage years due to cardiovascular diseases such as atherosclerosis, myocardial infarction, heart failure, and stroke. In this study, we characterized the G608G HGPS mouse model and explored cardiac and skeletal muscle function, along with senescence-associated phenotypes in fibroblasts. Homozygous G608G HGPS mice exhibited cardiac dysfunction, including decreased cardiac output and stroke volume, and impaired left ventricle relaxation. Additionally, skeletal muscle exhibited decreased isometric tetanic torque, muscle atrophy, and increased fibrosis. HGPS fibroblasts showed nuclear abnormalities, decreased proliferation, and increased expression of senescence markers. These findings provide insights into the pathophysiology of the G608G HGPS mouse model and inform potential therapeutic strategies for HGPS.

Hutchinson-Gilford progeria syndrome mice display accelerated arterial thrombus formation and increased platelet reactivity

INTRODUCTION

Hutchinson-Gilford Progeria Syndrome (HGPS) is an ultra-rare premature aging genetic disorder caused by a point mutation in the lamin A gene, LMNA. Children with HGPS display short lifespans and typically die due to myocardial infarction or ischemic stroke, both acute cardiovascular events that are tightly linked to arterial thrombosis. Despite this fact, the effect of the classic HGPS LMNA gene mutation on arterial thrombosis remains unknown.

METHODS

Heterozygous LmnaG609G knock-in (LmnaG609G/+) mice, yielding an equivalent classic mutation observed in HGPS patients (c.1824C>T; pG608G mutation in the human LMNA gene) and corresponding wild-type (WT) control littermates underwent photochemically laser-induced carotid injury to trigger thrombosis. Coagulation and fibrinolytic factors were measured. Furthermore, platelet activation and reactivity were investigated.

RESULTS

LmnaG609G/+ mice displayed accelerated arterial thrombus formation, as underlined by shortened time to occlusion compared to WT littermates. Levels of factors involved in the coagulation and fibrinolytic system were comparable between groups, while LmnaG609G/+ animals showed higher plasma levels of thrombin-antithrombin complex and lower levels of antithrombin. Bone marrow analysis showed larger megakaryocytes in progeric mice. Lastly, enhanced platelet activation upon adenosine diphosphate, collagen-related peptide, and thrombin stimulation was observed in LmnaG609G/+ animals compared to the WT group, indicating a higher platelet reactivity in progeric animals.

CONCLUSIONS

LMNA mutation in HGPS mice accelerates arterial thrombus formation, which is mediated, at least in part, by enhanced platelet reactivity, which consequently augments thrombin generation. Given the wide spectrum of antiplatelet agents available clinically, further investigation is warranted to consider the most suitable antiplatelet regimen for children with HGPS to mitigate disease mortality and morbidity.

Senescent endothelial cells promote pathogenic neutrophil trafficking in inflamed tissues

Cellular senescence is a hallmark of advanced age and a major instigator of numerous inflammatory pathologies. While endothelial cell (EC) senescence is aligned with defective vascular functionality, its impact on fundamental inflammatory responses in vivo at single-cell level remain unclear. To directly investigate the role of EC senescence on dynamics of neutrophil-venular wall interactions, we applied high resolution confocal intravital microscopy to inflamed tissues of an EC-specific progeroid mouse model, characterized by profound indicators of EC senescence. Progerin-expressing ECs supported prolonged neutrophil adhesion and crawling in a cell autonomous manner that additionally mediated neutrophil-dependent microvascular leakage. Transcriptomic and immunofluorescence analysis of inflamed tissues identified elevated levels of EC CXCL1 on progerin-expressing ECs and functional blockade of CXCL1 suppressed the dysregulated neutrophil responses elicited by senescent ECs. Similarly, cultured progerin-expressing human ECs exhibited a senescent phenotype, were pro-inflammatory and prompted increased neutrophil attachment and activation. Collectively, our findings support the concept that senescent ECs drive excessive inflammation and provide new insights into the mode, dynamics, and mechanisms of this response at single-cell level.

Progerin mRNA expression in non-HGPS patients is correlated with widespread shifts in transcript isoforms

Hutchinson-Gilford Progeria Syndrome (HGPS) is a premature aging disease caused primarily by a C1824T mutation in LMNA. This mutation activates a cryptic splice donor site, producing a lamin variant called progerin. Interestingly, progerin has also been detected in cells and tissues of non-HGPS patients. Here, we investigated progerin expression using publicly available RNA-seq data from non-HGPS patients in the GTEx project. We found that progerin expression is present across all tissue types in non-HGPS patients and correlated with telomere shortening in the skin. Transcriptome-wide correlation analyses suggest that the level of progerin expression is correlated with switches in gene isoform expression patterns. Differential expression analyses show that progerin expression is correlated with significant changes in genes involved in splicing regulation and mitochondrial function. Interestingly, 5' splice sites whose use is correlated with progerin expression have significantly altered frequencies of consensus trinucleotides within the core 5' splice site. Furthermore, introns whose alternative splicing correlates with progerin have reduced GC content. Our study suggests that progerin expression in non-HGPS patients is part of a global shift in splicing patterns.

Inflammation and Fibrosis in Progeria: Organ-Specific Responses in an HGPS Mouse Model

Hutchinson-Gilford Progeria Syndrome (HGPS) is an extremely rare genetic disorder that causes accelerated aging, due to a pathogenic variant in the LMNA gene. This pathogenic results in the production of progerin, a defective protein that disrupts the nuclear lamina's structure. In our study, we conducted a histopathological analysis of various organs in the LmnaG609G/G609G mouse model, which is commonly used to study HGPS. The objective of this study was to show that progerin accumulation drives systemic but organ-specific tissue damage and accelerated aging phenotypes. Our findings show significant fibrosis, inflammation, and dysfunction in multiple organ systems, including the skin, cardiovascular system, muscles, lungs, liver, kidneys, spleen, thymus, and heart. Specifically, we observed severe vascular fibrosis, reduced muscle regeneration, lung tissue remodeling, depletion of fat in the liver, and disruptions in immune structures. These results underscore the systemic nature of the disease and suggest that chronic inflammation and fibrosis play crucial roles in the accelerated aging seen in HGPS. Additionally, our study highlights that each organ responds differently to the toxic effects of progerin, indicating that there are distinct mechanisms of tissue-specific damage.

Lipodystrophic Laminopathies: From Dunnigan Disease to Progeroid Syndromes

Lipodystrophic laminopathies are a group of ultra-rare disorders characterised by the presence of pathogenic variants in the same gene (LMNA) and other related genes, along with an impaired adipose tissue pattern and other features that are specific of each of these disorders. The most fascinating traits include their complex genotype-phenotype associations and clinical heterogeneity, ranging from Dunnigan disease, in which the most relevant feature is precisely adipose tissue dysfunction and lipodystrophy, to the other laminopathies affecting adipose tissue, which are also characterised by the presence of signs of premature ageing (Hutchinson Gilford-progeria syndrome, LMNA-atypical progeroid syndrome, mandibuloacral dysplasia types A and B, Nestor-Guillermo progeria syndrome, LMNA-associated cardiocutaneous progeria). This raises several questions when it comes to understanding how variants in the same gene can lead to similar adipose tissue disturbances and, at the same time, to such heterogeneous phenotypes and variable degrees of metabolic abnormalities. The present review aims to gather the molecular basis of adipose tissue impairment in lipodystrophic laminopathies, their main clinical aspects and recent therapeutic strategies. In addition, it also summarises the key aspects for their differential diagnosis.

Mechanotransduction of the vasculature in Hutchinson-Gilford Progeria Syndrome

Hutchinson-Gilford Progeria Syndrome (HGPS) is a premature aging disorder that causes severe cardiovascular disease, resulting in the death of patients in their teenage years. The disease pathology is caused by the accumulation of progerin, a mutated form of the nuclear lamina protein, lamin A. Progerin binds to the inner nuclear membrane, disrupting nuclear integrity, and causes severe nuclear abnormalities and changes in gene expression. This results in increased cellular inflammation, senescence, and overall dysfunction. The molecular mechanisms by which progerin induces the disease pathology are not fully understood. Progerin's detrimental impact on nuclear mechanics and the role of the nucleus as a mechanosensor suggests dysfunctional mechanotransduction could play a role in HGPS. This is especially relevant in cells exposed to dynamic, continuous mechanical stimuli, like those of the vasculature. The endothelial (ECs) and smooth muscle cells (SMCs) within arteries rely on physical forces produced by blood flow to maintain function and homeostasis. Certain regions within arteries produce disturbed flow, leading to an impaired transduction of mechanical signals, and a reduction in cellular function, which also occurs in HGPS. In this review, we discuss the mechanics of nuclear mechanotransduction, how this is disrupted in HGPS, and what effect this has on cell health and function. We also address healthy responses of ECs and SMCs to physiological mechanical stimuli and how these responses are impaired by progerin accumulation.

Anesthetic Management of Cardiopulmonary Bypass in Hutchinson-Gilford Progeria Syndrome: A Case Report

Hutchinson-Gilford Progeria Syndrome (HGPS) is an ultrarare disorder of segmental premature aging that is associated with the development of advanced atherosclerosis and significant cardiovascular and cerebrovascular disease. Treatment with lonafarnib has improved survival in patients with HGPS; however, in extended longitudinal follow-up, there has been an increase in the prevalence of rapidly progressive calcific aortic stenosis. The evolving course of HGPS has prompted reconsideration of conservative management and led to the development of strategies for anatomic treatment. In this case report, we describe the anesthetic management of patients with HGPS undergoing surgical management of aortic stenosis with cardiopulmonary bypass.

Cracking the code of the cardiovascular enigma: hPSC-derived endothelial cells unveil the secrets of endothelial dysfunction

Endothelial dysfunction is a central contributor to the development of most cardiovascular diseases and is characterised by the reduced synthesis or bioavailability of the vasodilator nitric oxide together with other abnormalities such as inflammation, senescence, and oxidative stress. The use of patient-specific and genome-edited human pluripotent stem cell-derived endothelial cells (hPSC-ECs) has shed novel insights into the role of endothelial dysfunction in cardiovascular diseases with strong genetic components such as genetic cardiomyopathies and pulmonary arterial hypertension. However, their utility in studying complex multifactorial diseases such as atherosclerosis, metabolic syndrome and heart failure poses notable challenges. In this review, we provide an overview of the different methods used to generate and characterise hPSC-ECs before comprehensively assessing their effectiveness in cardiovascular disease modelling and high-throughput drug screening. Furthermore, we explore current obstacles that will need to be overcome to unleash the full potential of hPSC-ECs in facilitating patient-specific precision medicine. Addressing these challenges holds great promise in advancing our understanding of intricate cardiovascular diseases and in tailoring personalised therapeutic strategies.

Progeria-based vascular model identifies networks associated with cardiovascular aging and disease

Hutchinson-Gilford Progeria syndrome (HGPS) is a lethal premature aging disorder caused by a de novo heterozygous mutation that leads to the accumulation of a splicing isoform of Lamin A termed progerin. Progerin expression deregulates the organization of the nuclear lamina and the epigenetic landscape. Progerin has also been observed to accumulate at low levels during normal aging in cardiovascular cells of adults that do not carry genetic mutations linked with HGPS. Therefore, the molecular mechanisms that lead to vascular dysfunction in HGPS may also play a role in vascular aging-associated diseases, such as myocardial infarction and stroke. Here, we show that HGPS patient-derived vascular smooth muscle cells (VSMCs) recapitulate HGPS molecular hallmarks. Transcriptional profiling revealed cardiovascular disease remodeling and reactive oxidative stress response activation in HGPS VSMCs. Proteomic analyses identified abnormal acetylation programs in HGPS VSMC replication fork complexes, resulting in reduced H4K16 acetylation. Analysis of acetylation kinetics revealed both upregulation of K16 deacetylation and downregulation of K16 acetylation. This correlates with abnormal accumulation of error-prone nonhomologous end joining (NHEJ) repair proteins on newly replicated chromatin. The knockdown of the histone acetyltransferase MOF recapitulates preferential engagement of NHEJ repair activity in control VSMCs. Additionally, we find that primary donor-derived coronary artery vascular smooth muscle cells from aged individuals show similar defects to HGPS VSMCs, including loss of H4K16 acetylation. Altogether, we provide insight into the molecular mechanisms underlying vascular complications associated with HGPS patients and normative aging.

Manufacturing and validation of small-diameter vascular grafts: A mini review

The field of small-diameter vascular grafts remains a challenge for biomaterials scientists. While decades of research have brought us much closer to developing biomimetic materials for regenerating tissues and organs, the physiological challenges involved in manufacturing small conduits that can transport blood while not inducing an immune response or promoting blood clots continue to limit progress in this area. In this short review, we present some of the most recent methods and advancements made by researchers working in the field of small-diameter vascular grafts. We also discuss some of the most critical aspects biomaterials scientists should consider when developing lab-made small-diameter vascular grafts.

What Causes Premature Coronary Artery Disease?

PURPOSE OF REVIEW

This review provides an overview of genetic and non-genetic causes of premature coronary artery disease (pCAD).

RECENT FINDINGS

pCAD refers to coronary artery disease (CAD) occurring before the age of 65 years in women and 55 years in men. Both genetic and non-genetic risk factors may contribute to the onset of pCAD. Recent advances in the genetic epidemiology of pCAD have revealed the importance of both monogenic and polygenic contributions to pCAD. Familial hypercholesterolemia (FH) is the most common monogenic disorder associated with atherosclerotic pCAD. However, clinical overreliance on monogenic genes can result in overlooked genetic causes of pCAD, especially polygenic contributions. Non-genetic factors, notably smoking and drug use, are also important contributors to pCAD. Cigarette smoking has been observed in 25.5% of pCAD patients relative to 12.2% of non-pCAD patients. Finally, myocardial infarction (MI) associated with spontaneous coronary artery dissection (SCAD) may result in similar clinical presentations as atherosclerotic pCAD. Recognizing the genetic and non-genetic causes underlying pCAD is important for appropriate prevention and treatment. Despite recent progress, pCAD remains incompletely understood, highlighting the need for both awareness and research.

Determinants of Chromatin Organization in Aging and Cancer-Emerging Opportunities for Epigenetic Therapies and AI Technology

This review article critically examines the pivotal role of chromatin organization in gene regulation, cellular differentiation, disease progression and aging. It explores the dynamic between the euchromatin and heterochromatin, coded by a complex array of histone modifications that orchestrate essential cellular processes. We discuss the pathological impacts of chromatin state misregulation, particularly in cancer and accelerated aging conditions such as progeroid syndromes, and highlight the innovative role of epigenetic therapies and artificial intelligence (AI) in comprehending and harnessing the histone code toward personalized medicine. In the context of aging, this review explores the use of AI and advanced machine learning (ML) algorithms to parse vast biological datasets, leading to the development of predictive models for epigenetic modifications and providing a framework for understanding complex regulatory mechanisms, such as those governing cell identity genes. It supports innovative platforms like CEFCIG for high-accuracy predictions and tools like GridGO for tailored ChIP-Seq analysis, which are vital for deciphering the epigenetic landscape. The review also casts a vision on the prospects of AI and ML in oncology, particularly in the personalization of cancer therapy, including early diagnostics and treatment optimization for diseases like head and neck and colorectal cancers by harnessing computational methods, AI advancements and integrated clinical data for a transformative impact on healthcare outcomes.

Life at the crossroads: the nuclear LINC complex and vascular mechanotransduction

Vascular endothelial cells line the inner surface of all blood vessels, where they are exposed to polarized mechanical forces throughout their lifespan. Both basal substrate interactions and apical blood flow-induced shear stress regulate blood vessel development, remodeling, and maintenance of vascular homeostasis. Disruption of these interactions leads to dysfunction and vascular pathologies, although how forces are sensed and integrated to affect endothelial cell behaviors is incompletely understood. Recently the endothelial cell nucleus has emerged as a prominent force-transducing organelle that participates in vascular mechanotransduction, via communication to and from cell-cell and cell-matrix junctions. The LINC complex, composed of SUN and nesprin proteins, spans the nuclear membranes and connects the nuclear lamina, the nuclear envelope, and the cytoskeleton. Here we review LINC complex involvement in endothelial cell mechanotransduction, describe unique and overlapping functions of each LINC complex component, and consider emerging evidence that two major SUN proteins, SUN1 and SUN2, orchestrate a complex interplay that extends outward to cell-cell and cell-matrix junctions and inward to interactions within the nucleus and chromatin. We discuss these findings in relation to vascular pathologies such as Hutchinson-Gilford progeria syndrome, a premature aging disorder with cardiovascular impairment. More knowledge of LINC complex regulation and function will help to understand how the nucleus participates in endothelial cell force sensing and how dysfunction leads to cardiovascular disease.

Intervention for critical aortic stenosis in Hutchinson-Gilford progeria syndrome

Hutchinson-Gilford Progeria Syndrome (HGPS) is an ultra-rare genetic premature aging disease that is historically fatal in teenage years, secondary to severe accelerated atherosclerosis. The only approved treatment is the farnesyltransferase inhibitor lonafarnib, which improves vascular structure and function, extending average untreated lifespan of 14.5 years by 4.3 years (30%). With this longer lifespan, calcific aortic stenosis (AS) was identified as an emerging critical risk factor for cardiac death in older patients. Intervention to relieve critical AS has the potential for immediate improvement in healthspan and lifespan. However, HGPS patient-device size mismatch, pervasive peripheral arterial disease, skin and bone abnormalities, and lifelong failure to thrive present unique challenges to intervention. An international group of experts in HGPS, pediatric and adult cardiology, cardiac surgery, and pediatric critical care convened to identify strategies for successful treatment. Candidate procedures were evaluated by in-depth examination of 4 cases that typify HGPS clinical pathology. Modified transcatheter aortic valve replacement (TAVR) and left ventricular Apico-Aortic Conduit (AAC) placement were deemed high risk but viable options. Two cases received TAVR and 2 received AAC post-summit. Three were successful and 1 patient died perioperatively due to cardiovascular disease severity, highlighting the importance of intervention timing and comparative risk stratification. These breakthrough interventions for treating critical aortic stenosis in HGPS patients could rewrite the current clinical perspective on disease course by greatly improving late-stage quality of life and increasing lifespan. Expanding worldwide medical and surgical competency for this ultra-rare disease through expert information-sharing could have high impact on treatment success.

Molecular hallmarks of ageing in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal, severely debilitating and rapidly progressing disorder affecting motor neurons in the brain, brainstem, and spinal cord. Unfortunately, there are few effective treatments, thus there remains a critical need to find novel interventions that can mitigate against its effects. Whilst the aetiology of ALS remains unclear, ageing is the major risk factor. Ageing is a slowly progressive process marked by functional decline of an organism over its lifespan. However, it remains unclear how ageing promotes the risk of ALS. At the molecular and cellular level there are specific hallmarks characteristic of normal ageing. These hallmarks are highly inter-related and overlap significantly with each other. Moreover, whilst ageing is a normal process, there are striking similarities at the molecular level between these factors and neurodegeneration in ALS. Nine ageing hallmarks were originally proposed: genomic instability, loss of telomeres, senescence, epigenetic modifications, dysregulated nutrient sensing, loss of proteostasis, mitochondrial dysfunction, stem cell exhaustion, and altered inter-cellular communication. However, these were recently (2023) expanded to include dysregulation of autophagy, inflammation and dysbiosis. Hence, given the latest updates to these hallmarks, and their close association to disease processes in ALS, a new examination of their relationship to pathophysiology is warranted. In this review, we describe possible mechanisms by which normal ageing impacts on neurodegenerative mechanisms implicated in ALS, and new therapeutic interventions that may arise from this.

Lamin A/C and PI(4,5)P2-A Novel Complex in the Cell Nucleus

Lamins, the nuclear intermediate filaments, are important regulators of nuclear structural integrity as well as nuclear functional processes such as DNA transcription, replication and repair, and epigenetic regulations. A portion of phosphorylated lamin A/C localizes to the nuclear interior in interphase, forming a lamin A/C pool with specific properties and distinct functions. Nucleoplasmic lamin A/C molecular functions are mainly dependent on its binding partners; therefore, revealing new interactions could give us new clues on the lamin A/C mechanism of action. In the present study, we show that lamin A/C interacts with nuclear phosphoinositides (PIPs), and with nuclear myosin I (NM1). Both NM1 and nuclear PIPs have been previously reported as important regulators of gene expression and DNA damage/repair. Furthermore, phosphorylated lamin A/C forms a complex with NM1 in a phosphatidylinositol-4,5-bisphosphate (PI(4,5)P2)-dependent manner in the nuclear interior. Taken together, our study reveals a previously unidentified interaction between phosphorylated lamin A/C, NM1, and PI(4,5)P2 and suggests new possible ways of nucleoplasmic lamin A/C regulation, function, and importance for the formation of functional nuclear microdomains.

Coronary and carotid artery dysfunction and KV7 overexpression in a mouse model of Hutchinson-Gilford progeria syndrome

Hutchinson-Gilford progeria syndrome (HGPS) is an extremely rare genetic disease caused by expression of progerin, a lamin A variant that is also expressed at low levels in non-HGPS individuals. Although HGPS patients die predominantly from myocardial infarction and stroke, the mechanisms that provoke pathological alterations in the coronary and cerebral arteries in HGPS remain ill defined. Here, we assessed vascular function in the coronary arteries (CorAs) and carotid arteries (CarAs) of progerin-expressing LmnaG609G/G609G mice (G609G), both in resting conditions and after hypoxic stimulus. Wire myography, pharmacological screening, and gene expression studies demonstrated vascular atony and stenosis, as well as other functional alterations in progeroid CorAs and CarAs and aorta. These defects were associated with loss of vascular smooth muscle cells and overexpression of the KV7 family of voltage-dependent potassium channels. Compared with wild-type controls, G609G mice showed reduced median survival upon chronic isoproterenol exposure, a baseline state of chronic cardiac hypoxia characterized by overexpression of hypoxia-inducible factor 1α and 3α genes, and increased cardiac vascularization. Our results shed light on the mechanisms underlying progerin-induced coronary and carotid artery disease and identify KV7 channels as a candidate target for the treatment of HGPS.

Hutchinson-Gilford progeria syndrome: unraveling the genetic basis, symptoms, and advancements in therapeutic approaches

Hutchinson-Gilford Progeria syndrome (HGPS) serves as a prominent model for Progeroid syndromes, a group of rare genetic disorders characterized by accelerated aging. This review explores the genetic basis, clinical presentation, and complications of HGPS. HGPS is caused by mutations in the LMNA gene, resulting in the production of a defective structural protein, prelamin A. This protein contains a "CAAX" motif, where C represents cysteine, and its abnormal processing is central to the disease's pathology. HGPS leads to multiple organ systems being affected, including cardiovascular, skeletal, neurological, and dermatological systems, causing severe disability and increased mortality. Cardiovascular issues are particularly significant in HGPS and are crucial for developing therapeutic strategies. Recent advances in treatment modalities offer promise for managing HGPS. Farnesyltransferase inhibitors and genetic interventions, such as CRISPR-Cas9, have shown potential in mitigating progerin-associated symptoms, with encouraging results observed in preclinical and clinical studies. Additionally, emerging therapies such as rapamycin, sulforaphane, and MG132 hold promise in targeting underlying disease mechanisms. Comprehensive management approaches, including growth hormone therapy, retinoids, and dental care, are emphasized to enhance overall patient well-being. Despite progress, further research is essential to unravel the complex pathophysiology of Progeroid syndromes and develop effective treatments. Continued focus on therapies that address progerin accumulation and its downstream effects is vital for improving patient care and outcomes for individuals affected by HGPS and related disorders. This review highlights ongoing efforts to understand and combat Progeroid syndromes, aiming to alleviate the burdens imposed by these debilitating conditions.

Lamin A/C mediates microglial activation by modulating cell proliferation and immune response

Lamin A/C is involved in macrophage activation and premature aging, also known as progeria. As the resident macrophage in brain, overactivation of microglia causes brain inflammation, promoting aging and brain disease. In this study, we investigated the role of Lamin A/C in microglial activation and its impact on progeria using Lmna-/- mice, primary microglia, Lmna knockout (Lmna-KO) and Lmna-knockdown (Lmna-KD) BV2 cell lines. We found that the microglial activation signatures, including cell proliferation, morphology changes, and proinflammatory cytokine secretion (IL-1β, IL-6, and TNF-α), were significantly suppressed in all Lamin A/C-deficient models when stimulated with LPS. TMT-based quantitative proteomic and bioinformatic analysis were further applied to explore the mechanism of Lamin A/C-regulated microglia activation from the proteome level. The results revealed that immune response and phagocytosis were impaired in Lmna-/- microglia. Stat1 was identified as the hub protein in the mechanism by which Lamin A/C regulates microglial activation. Additionally, DNA replication, chromatin organization, and mRNA processing were also altered by Lamin A/C, with Ki67 fulfilling the main hub function. Lamin A/C is a mechanosensitive protein and, the immune- and proliferation-related biological processes are also regulated by mechanotransduction. We speculate that Lamin A/C-mediated mechanotransduction is required for microglial activation. Our study proposes a novel mechanism for microglial activation mediated by Lamin A/C.

Clinical Impact and Mechanisms of Nonatherosclerotic Vascular Aging: The New Kid to Be Blocked

Ischemic cardiovascular disease and stroke remain the leading cause of global morbidity and mortality. During aging, protective mechanisms in the body gradually deteriorate, resulting in functional, structural, and morphologic changes that affect the vascular system. Because atherosclerotic plaques are not always present along with these alterations, we refer to this kind of vascular aging as nonatherosclerotic vascular aging (NAVA). To maintain proper vascular function during NAVA, it is important to preserve intracellular signalling, prevent inflammation, and block the development of senescent cells. Pharmacologic interventions targeting these components are potential therapeutic approaches for NAVA, with a particular emphasis on inflammation and senescence. This review provides an overview of the pathophysiology of vascular aging and explores potential pharmacotherapies that can improve the function of aged vasculature, focusing on NAVA.

Prelamin A and ZMPSTE24 in premature and physiological aging

As human longevity increases, understanding the molecular mechanisms that drive aging becomes ever more critical to promote health and prevent age-related disorders. Premature aging disorders or progeroid syndromes can provide critical insights into aspects of physiological aging. A major cause of progeroid syndromes which result from mutations in the genes LMNA and ZMPSTE24 is disruption of the final posttranslational processing step in the production of the nuclear scaffold protein lamin A. LMNA encodes the lamin A precursor, prelamin A and ZMPSTE24 encodes the prelamin A processing enzyme, the zinc metalloprotease ZMPSTE24. Progeroid syndromes resulting from mutations in these genes include the clinically related disorders Hutchinson-Gilford progeria syndrome (HGPS), mandibuloacral dysplasia-type B, and restrictive dermopathy. These diseases have features that overlap with one another and with some aspects of physiological aging, including bone defects resembling osteoporosis and atherosclerosis (the latter primarily in HGPS). The progeroid syndromes have ignited keen interest in the relationship between defective prelamin A processing and its accumulation in normal physiological aging. In this review, we examine the hypothesis that diminished processing of prelamin A by ZMPSTE24 is a driver of physiological aging. We review features a new mouse (LmnaL648R/L648R) that produces solely unprocessed prelamin A and provides an ideal model for examining the effects of its accumulation during aging. We also discuss existing data on the accumulation of prelamin A or its variants in human physiological aging, which call out for further validation and more rigorous experimental approaches to determine if prelamin A contributes to normal aging.

Hallmarks of cardiovascular ageing

Normal circulatory function is a key determinant of disease-free life expectancy (healthspan). Indeed, pathologies affecting the cardiovascular system, which are growing in prevalence, are the leading cause of global morbidity, disability and mortality, whereas the maintenance of cardiovascular health is necessary to promote both organismal healthspan and lifespan. Therefore, cardiovascular ageing might precede or even underlie body-wide, age-related health deterioration. In this Review, we posit that eight molecular hallmarks are common denominators in cardiovascular ageing, namely disabled macroautophagy, loss of proteostasis, genomic instability (in particular, clonal haematopoiesis of indeterminate potential), epigenetic alterations, mitochondrial dysfunction, cell senescence, dysregulated neurohormonal signalling and inflammation. We also propose a hierarchical order that distinguishes primary (upstream) from antagonistic and integrative (downstream) hallmarks of cardiovascular ageing. Finally, we discuss how targeting each of the eight hallmarks might be therapeutically exploited to attenuate residual cardiovascular risk in older individuals.

Use of Farnesyl Transferase Inhibitors in an Ageing Model in Drosophila

The presence of farnesylated proteins at the inner nuclear membrane (INM), such as the Lamins or Kugelkern in Drosophila, leads to specific changes in the nuclear morphology and accelerated ageing on the organismal level reminiscent of the Hutchinson-Gilford progeria syndrome (HGPS). Farnesyl transferase inhibitors (FTIs) can suppress the phenotypes of the nuclear morphology in cultured fibroblasts from HGPS patients and cultured cells overexpressing farnesylated INM proteins. Similarly, FTIs have been reported to suppress the shortened lifespan in model organisms. Here, we report an experimental system combining cell culture and Drosophila flies for testing the activity of substances on the HGPS-like nuclear morphology and lifespan, with FTIs as an experimental example. Consistent with previous reports, we show that FTIs were able to ameliorate the nuclear phenotypes induced by the farnesylated nuclear proteins Progerin, Kugelkern, or truncated Lamin B in cultured cells. The subsequent validation in Drosophila lifespan assays demonstrated the applicability of the experimental system: treating adult Drosophila with the FTI ABT-100 reversed the nuclear phenotypes and extended the lifespan of experimentally induced short-lived flies. Since kugelkern-expressing flies have a significantly shorter average lifespan, half the time is needed for testing substances in the lifespan assay.

Model Systems to Study the Mechanism of Vascular Aging

Cardiovascular diseases are the leading cause of death globally. Within cardiovascular aging, arterial aging holds significant importance, as it involves structural and functional alterations in arteries that contribute substantially to the overall decline in cardiovascular health during the aging process. As arteries age, their ability to respond to stress and injury diminishes, while their luminal diameter increases. Moreover, they experience intimal and medial thickening, endothelial dysfunction, loss of vascular smooth muscle cells, cellular senescence, extracellular matrix remodeling, and deposition of collagen and calcium. This aging process also leads to overall arterial stiffening and cellular remodeling. The process of genomic instability plays a vital role in accelerating vascular aging. Progeria syndromes, rare genetic disorders causing premature aging, exemplify the impact of genomic instability. Throughout life, our DNA faces constant challenges from environmental radiation, chemicals, and endogenous metabolic products, leading to DNA damage and genome instability as we age. The accumulation of unrepaired damages over time manifests as an aging phenotype. To study vascular aging, various models are available, ranging from in vivo mouse studies to cell culture options, and there are also microfluidic in vitro model systems known as vessels-on-a-chip. Together, these models offer valuable insights into the aging process of blood vessels.

Disrupted Stiffness Ratio Alters Nuclear Mechanosensing

The ability of endothelial cells to sense and respond to dynamic changes in blood flow is critical for vascular homeostasis and cardiovascular health. The mechanical and geometric properties of the nuclear and cytoplasmic compartments affect mechanotransduction. We hypothesized that alterations to these parameters have resulting mechanosensory consequences. Using atomic force microscopy and mathematical modeling, we assessed how the nuclear and cytoplasmic compartment stiffnesses modulate shear stress transfer to the nucleus within aging endothelial cells. Our computational studies revealed that the critical parameter controlling shear transfer is not the individual mechanics of these compartments, but the stiffness ratio between them. Replicatively aged cells had a reduced stiffness ratio, attenuating shear transfer, while the ratio was not altered in a genetic model of accelerated aging. We provide a theoretical framework suggesting that dysregulation of the shear stress response can be uniquely imparted by relative mechanical changes in subcellular compartments.

Nuclear mechanosensing of the aortic endothelium in health and disease

The endothelium, the monolayer of endothelial cells that line blood vessels, is exposed to a number of mechanical forces, including frictional shear flow, pulsatile stretching and changes in stiffness influenced by extracellular matrix composition. These forces are sensed by mechanosensors that facilitate their transduction to drive appropriate adaptation of the endothelium to maintain vascular homeostasis. In the aorta, the unique architecture of the vessel gives rise to changes in the fluid dynamics, which, in turn, shape cellular morphology, nuclear architecture, chromatin dynamics and gene regulation. In this Review, we discuss recent work focusing on how differential mechanical forces exerted on endothelial cells are sensed and transduced to influence their form and function in giving rise to spatial variation to the endothelium of the aorta. We will also discuss recent developments in understanding how nuclear mechanosensing is implicated in diseases of the aorta.

Progerin, an Aberrant Spliced Form of Lamin A, Is a Potential Therapeutic Target for HGPS

Hutchinson-Gilford progeria syndrome (HGPS) is an extremely rare genetic disorder caused by the mutant protein progerin, which is expressed by the abnormal splicing of the LMNA gene. HGPS affects systemic levels, with the exception of cognition or brain development, in children, showing that cellular aging can occur in the short term. Studying progeria could be useful in unraveling the causes of human aging (as well as fatal age-related disorders). Elucidating the clear cause of HGPS or the development of a therapeutic medicine could improve the quality of life and extend the survival of patients. This review aimed to (i) briefly describe how progerin was discovered as the causative agent of HGPS, (ii) elucidate the puzzling observation of the absence of primary neurological disease in HGPS, (iii) present several studies showing the deleterious effects of progerin and the beneficial effects of its inhibition, and (iv) summarize research to develop a therapy for HGPS and introduce clinical trials for its treatment.

Biomechanical and transcriptional evidence that smooth muscle cell death drives an osteochondrogenic phenotype and severe proximal vascular disease in progeria

Hutchinson-Gilford Progeria Syndrome results in rapid aging and severe cardiovascular sequelae that accelerate near end-of-life. We found a progressive disease process in proximal elastic arteries that was less evident in distal muscular arteries. Changes in aortic structure and function were then associated with changes in transcriptomics assessed via both bulk and single cell RNA sequencing, which suggested a novel sequence of progressive aortic disease: adverse extracellular matrix remodeling followed by mechanical stress-induced smooth muscle cell death, leading a subset of remnant smooth muscle cells to an osteochondrogenic phenotype that results in an accumulation of proteoglycans that thickens the aortic wall and increases pulse wave velocity, with late calcification exacerbating these effects. Increased central artery pulse wave velocity is known to drive left ventricular diastolic dysfunction, the primary diagnosis in progeria children. It appears that mechanical stresses above ~ 80 kPa initiate this progressive aortic disease process, explaining why elastic lamellar structures that are organized early in development under low wall stresses appear to be nearly normal whereas other medial constituents worsen progressively in adulthood. Mitigating early mechanical stress-driven smooth muscle cell loss/phenotypic modulation promises to have important cardiovascular implications in progeria patients.