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PeerJ 2023Aging is a natural and complex process characterized by the gradual deterioration of tissue and physiological functions in the organism over time. Cell senescence, a...
Aging is a natural and complex process characterized by the gradual deterioration of tissue and physiological functions in the organism over time. Cell senescence, a hallmark of aging, refers to the permanent and irreversible cell cycle arrest of proliferating cells triggered by endogenous stimuli or environmental stresses. Eliminating senescent cells has been shown to extend the healthy lifespan. In this study, we established a progeria mouse model with telomerase deficiency and confirmed the presence of shortened telomere length and increased expression of aging markers and in the organ tissues of G3 mice. We identified fisetin as a potent senolytic drug capable of reversing premature aging signs in telomerase-deficient mice. Fisetin treatment effectively suppressed the upregulation of aging markers and and reduced collagen fiber deposition. Furthermore, we observed a significant elevation in the mRNA level of in G3 mice, which was reduced after fisetin treatment. Stc1 has been implicated in anti-apoptotic processes through the upregulation of the Akt signaling pathway. Our findings reveal that fisetin exerts its anti-aging effect by inhibiting the Akt signaling pathway through the suppression of expression, leading to the apoptosis of senescent cells.
Topics: Animals; Mice; Telomerase; Cyclin-Dependent Kinase Inhibitor p16; Progeria; Proto-Oncogene Proteins c-akt; Telomere Shortening; Telomere; Aging
PubMed: 38107570
DOI: 10.7717/peerj.16463 -
The Journal of Cell Biology Jan 2024Mutations in genes encoding nuclear lamins cause diseases called laminopathies. In this issue, Hasper et al. (https://doi.org/10.1083/jcb.202307049) show that lamin A/C...
Mutations in genes encoding nuclear lamins cause diseases called laminopathies. In this issue, Hasper et al. (https://doi.org/10.1083/jcb.202307049) show that lamin A/C and the prelamin A variant in Hutchinson-Gilford progeria syndrome have relatively long lifetimes in affected tissues.
Topics: Humans; Lamins; Lamin Type A; Nuclear Lamina; Progeria
PubMed: 38078930
DOI: 10.1083/jcb.202311193 -
Nucleus (Austin, Tex.) Dec 2023Several related progeroid disorders are caused by defective post-translational processing of prelamin A, the precursor of the nuclear scaffold protein lamin A, encoded...
Several related progeroid disorders are caused by defective post-translational processing of prelamin A, the precursor of the nuclear scaffold protein lamin A, encoded by . Prelamin A undergoes farnesylation and additional modifications at its C-terminus. Subsequently, the farnesylated C-terminal segment is cleaved off by the zinc metalloprotease ZMPSTE24. The premature aging disorder Hutchinson Gilford progeria syndrome (HGPS) and a related progeroid disease, mandibuloacral dysplasia (MAD-B), are caused by mutations in and , respectively, that result in failure to process the lamin A precursor and accumulate permanently farnesylated forms of prelamin A. The farnesyl transferase inhibitor (FTI) lonafarnib is known to correct the aberrant nuclear morphology of HGPS patient cells and improves lifespan in children with HGPS. Importantly, and in contrast to a previous report, we show here that FTI treatment also improves the aberrant nuclear phenotypes in MAD-B patient cells with mutations in (P248L or L425P). As expected, lonafarnib does not correct nuclear defects for cells with lamin A processing-proficient mutations. We also examine prelamin A processing in fibroblasts from two individuals with a prevalent laminopathy mutation -R644C. Despite the proximity of residue R644 to the prelamin A cleavage site, neither R644C patient cell line shows a prelamin A processing defect, and both have normal nuclear morphology. This work clarifies the prelamin A processing status and role of FTIs in a variety of laminopathy patient cells and supports the FDA-approved indication for the FTI Zokinvy for patients with processing-deficient progeroid laminopathies, but not for patients with processing-proficient laminopathies.
Topics: Child; Humans; Lamin Type A; Progeria; Enzyme Inhibitors; Mutation; Lipodystrophy; Fibroblasts; Transferases; Metalloendopeptidases; Membrane Proteins
PubMed: 38050983
DOI: 10.1080/19491034.2023.2288476 -
Aging Cell Dec 2023The NAD -dependent deacylase family of sirtuin enzymes have been implicated in biological ageing, late-life health and overall lifespan, though of these members, a role...
The NAD -dependent deacylase family of sirtuin enzymes have been implicated in biological ageing, late-life health and overall lifespan, though of these members, a role for sirtuin-2 (SIRT2) is less clear. Transgenic overexpression of SIRT2 in the BubR1 hypomorph model of progeria can rescue many aspects of health and increase overall lifespan, due to a specific interaction between SIRT2 and BubR1 that improves the stability of this protein. It is less clear whether SIRT2 is relevant to biological ageing outside of a model where BubR1 is under-expressed. Here, we sought to test whether SIRT2 over-expression would impact the overall health and lifespan of mice on a nonprogeroid, wild-type background. While we previously found that SIRT2 transgenic overexpression prolonged female fertility, here, we did not observe any additional impact on health or lifespan, which was measured in both male and female mice on standard chow diets, and in males challenged with a high-fat diet. At the biochemical level, NMR studies revealed an increase in total levels of a number of metabolites in the brain of SIRT2-Tg animals, pointing to a potential impact in cell composition; however, this did not translate into functional differences. Overall, we conclude that strategies to enhance SIRT2 protein levels may not lead to increased longevity.
Topics: Animals; Female; Male; Mice; Aging; Animals, Genetically Modified; Brain; Longevity; Sirtuin 2
PubMed: 38009412
DOI: 10.1111/acel.14027 -
Journal of Developmental Biology Oct 2023The presence of farnesylated proteins at the inner nuclear membrane (INM), such as the Lamins or Kugelkern in , leads to specific changes in the nuclear morphology and...
The presence of farnesylated proteins at the inner nuclear membrane (INM), such as the Lamins or Kugelkern in , 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 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 lifespan assays demonstrated the applicability of the experimental system: treating adult with the FTI ABT-100 reversed the nuclear phenotypes and extended the lifespan of experimentally induced short-lived flies. Since -expressing flies have a significantly shorter average lifespan, half the time is needed for testing substances in the lifespan assay.
PubMed: 37987370
DOI: 10.3390/jdb11040040 -
Bioorganic Chemistry Jan 2024Hutchinson-Gilford progeria syndrome (HGPS) or progeria is a rare genetic disease that causes premature aging, leading to a drastic reduction in the life expectancy of...
Hutchinson-Gilford progeria syndrome (HGPS) or progeria is a rare genetic disease that causes premature aging, leading to a drastic reduction in the life expectancy of patients. Progeria is mainly caused by the intracellular accumulation of a defective protein called progerin, generated from a mutation in the LMNA gene. Currently, there is only one approved drug for the treatment of progeria, which has limited efficacy. It is believed that progerin levels are the most important biomarker related to the severity of the disease. However, there is a lack of effective tools to directly visualize progerin in the native cellular models, since the commercially available antibodies are not well suited for the direct visualization of progerin in cells from the mouse model of the disease. In this context, an alternative option for the visualization of a protein relies on the use of fluorescent chemical probes, molecules with affinity and specificity towards a protein. In this work we report the synthesis and characterization of a new fluorescent probe (UCM-23079) that allows for the direct visualization of progerin in cells from the most widely used progeroid mouse model. Thus, UCM-23079 is a new tool compound that could help prioritize potential preclinical therapies towards the final goal of finding a definitive cure for progeria.
Topics: Mice; Animals; Humans; Progeria; Fluorescent Dyes; Mutation
PubMed: 37979321
DOI: 10.1016/j.bioorg.2023.106967 -
Proceedings of the National Academy of... Nov 2023Patients with Hutchinson-Gilford progeria syndrome (HGPS) present with a number of premature aging phenotypes, including DNA damage accumulation, and many of them die of...
Patients with Hutchinson-Gilford progeria syndrome (HGPS) present with a number of premature aging phenotypes, including DNA damage accumulation, and many of them die of cardiovascular complications. Although vascular pathologies have been reported, whether HGPS patients exhibit cardiac dysfunction and its underlying mechanism is unclear, rendering limited options for treating HGPS-related cardiomyopathy. In this study, we reported a cardiac atrophy phenotype in the mice (hereafter, HGPS mice). Using a GFP-based reporter system, we demonstrated that the efficiency of nonhomologous end joining (NHEJ) declined by 50% in HGPS cardiomyocytes in vivo, due to the attenuated interaction between γH2AX and Progerin, the causative factor of HGPS. As a result, genomic instability in cardiomyocytes led to an increase of CHK2 protein level, promoting the LKB1-AMPKα interaction and AMPKα phosphorylation, which further led to the activation of FOXO3A-mediated transcription of atrophy-related genes. Moreover, inhibiting AMPK enlarged cardiomyocyte sizes both in vitro and in vivo. Most importantly, our proof-of-concept study indicated that isoproterenol treatment significantly reduced AMPKα and FOXO3A phosphorylation in the heart, attenuated the atrophy phenotype, and extended the mean lifespan of HGPS mice by ~21%, implying that targeting cardiac atrophy may be an approach to HGPS treatment.
Topics: Humans; Mice; Animals; Progeria; Aging, Premature; Heart; DNA Damage; Genomic Instability; AMP-Activated Protein Kinases; Lamin Type A
PubMed: 37967221
DOI: 10.1073/pnas.2309200120 -
Long lifetime and tissue-specific accumulation of lamin A/C in Hutchinson-Gilford progeria syndrome.The Journal of Cell Biology Jan 2024LMNA mutations cause laminopathies that afflict the cardiovascular system and include Hutchinson-Gilford progeria syndrome. The origins of tissue specificity in these...
LMNA mutations cause laminopathies that afflict the cardiovascular system and include Hutchinson-Gilford progeria syndrome. The origins of tissue specificity in these diseases are unclear as the lamin A/C proteins are broadly expressed. We show that LMNA transcript levels are not predictive of lamin A/C protein levels across tissues and use quantitative proteomics to discover that tissue context and disease mutation each influence lamin A/C protein's lifetime. Lamin A/C's lifetime is an order of magnitude longer in the aorta, heart, and fat, where laminopathy pathology is apparent, than in the liver and intestine, which are spared from the disease. Lamin A/C is especially insoluble in cardiovascular tissues, which may limit degradation and promote protein stability. Progerin is even more long lived than lamin A/C in the cardiovascular system and accumulates there over time. Progerin accumulation is associated with impaired turnover of hundreds of abundant proteins in progeroid tissues. These findings identify impaired lamin A/C protein turnover as a novel feature of laminopathy syndromes.
Topics: Humans; Lamin Type A; Mutation; Progeria; Proteomics
PubMed: 37966721
DOI: 10.1083/jcb.202307049 -
Nature Aging Nov 2023The stem cell theory of aging dictates that a decline in the number and/or function of stem cells causes tissue degeneration and aging; however, it still lacks...
The stem cell theory of aging dictates that a decline in the number and/or function of stem cells causes tissue degeneration and aging; however, it still lacks unequivocal experimental support. Here, using lineage tracing and single-cell transcriptomics, we identify a population of CD133 bone marrow-derived endothelial-like cells (ELCs) as potential endothelial progenitor cells, which contribute to tubular structures in vitro and neovascularization in vivo. We demonstrate that supplementation with wild-type and young ELCs respectively restores neovascularization and extends lifespan in progeric and naturally aged mice. Mechanistically, we identify an upregulation of farnesyl diphosphate synthase (FDPS) in aged CD133 ELCs-a key enzyme in isoprenoid biosynthesis. Overexpression of FDPS compromises the neovascularization capacity of CD133 ELCs, whereas FDPS inhibition by pamidronate enhances neovascularization, improves health measures and extends lifespan in aged mice. These findings highlight stem cell-based strategies for the treatment of progeria and age-related pathologies.
Topics: Mice; Animals; Endothelial Progenitor Cells; Longevity; Neovascularization, Pathologic; Stem Cells
PubMed: 37946040
DOI: 10.1038/s43587-023-00512-z -
Heliyon Oct 2023Hutchinson-Gilford progeria syndrome (HGPS) is an extremely rare disease characterized by appearance of premature aging, including the skin, bones, heart, and blood...
An infant with congenital micrognathia and upper airway obstruction was diagnosed as Hutchinson-Gilford progeria syndrome caused by a novel LMNA mutation: Case report and literature review.
Hutchinson-Gilford progeria syndrome (HGPS) is an extremely rare disease characterized by appearance of premature aging, including the skin, bones, heart, and blood vessels caused by LMNA mutation. In this study, the patient presented with congenital micrognathia and progressively aggravated upper airway obstruction as the initial symptom, which required bilateral mandibular distraction osteogenesis (MDO) surgery intervention. This was not commonly described in the literature, and the primary clinical diagnosis of Pierre Robin sequence (PRS) was made. However, other clinical features included sclerotic skin, dry skin, growth failure, lipoatrophy, joint stiffness, prominent scalp veins, small ear lobes, hair loss, and craniofacial disproportion gradually emerged, the diagnosis of HGPS was preferred when the patient was 5 months old. The genetic testing result with a novel and de novo LMNA mutation (c.1968 + 3_1968+6delGAGT) further confirmed the diagnosis and expanded the clinical and mutational spectrum of HGPS. During the 12-month follow-up period after surgery, the patient no longer suffered dyspnea. Complications of other organs and systems have not happened at the moment. In addition, the pathogenesis, the role of LMNA gene mutation, the progress in clinical treatment, and breakthrough studies about genetic treatment in animals of HGPS are described in the literature review.
PubMed: 37916118
DOI: 10.1016/j.heliyon.2023.e20857