RESUMO
In mammals, the most remarkable T cell variations with aging are the shrinking of the naïve T cell pool and the enlargement of the memory T cell pool, which are partially caused by thymic involution. However, the mechanism underlying the relationship between T-cell changes and aging remains unclear. In this study, we find that T-cell-specific Rip1 KO mice show similar age-related T cell changes and exhibit signs of accelerated aging-like phenotypes, including inflammation, multiple age-related diseases, and a shorter lifespan. Mechanistically, Rip1-deficient T cells undergo excessive apoptosis and promote chronic inflammation. Consistent with this, blocking apoptosis by co-deletion of Fadd in Rip1-deficient T cells significantly rescues lymphopenia, the imbalance between naïve and memory T cells, and aging-like phenotypes, and prolongs life span in T-cell-specific Rip1 KO mice. These results suggest that the reduction and hyperactivation of T cells can have a significant impact on organismal health and lifespan, underscoring the importance of maintaining T cell homeostasis for healthy aging and prevention or treatment of age-related diseases.
Assuntos
Senilidade Prematura , Linfócitos T , Animais , Camundongos , Envelhecimento/genética , Senilidade Prematura/genética , Apoptose , Inflamação , MamíferosRESUMO
Type 2 diabetes (T2D) constitutes a major public health problem, and despite prevention efforts, this pandemic disease is one of the deadliest diseases in the world. In 2022, 6.7 million patients with T2D died prematurely from vascular complications. Indeed, diabetes increases the risk of myocardial infarction or stroke eightfold. The identification of the molecular factors involved in the occurrence of cardiovascular complications and their prevention are therefore major axes. Our hypothesis is that factors brought into play during physiological aging appear prematurely with diabetes progression. Our study focused on the aging of the extracellular matrix (ECM), a major element in the maintenance of vascular homeostasis. We characterized the morphological and functional aspects of aorta, with a focus on the collagen and elastic fibers of diabetic mice aged from 6 mo to nondiabetic mice aged 6 mo and 20 mo. The comparison with the two nondiabetic models (young and old) highlighted an exacerbated activity of proteases, which could explain a disturbance in the collagen accumulation and an excessive degradation of elastic fibers. Moreover, the generation of circulating elastin-derived peptides reflects premature aging of the ECM. These extracellular elements contribute to the appearance of vascular rigidity, often the origin of pathologies such as hypertension and atherosclerosis. In conclusion, we show that diabetic mice aged 6 mo present the same characteristics of ECM wear as those observed in mice aged 20 mo. This accelerated aortic wall remodeling could then explain the early onset of cardiovascular diseases and, therefore, the premature death of patients with T2D.NEW & NOTEWORTHY Aortic elastic fibers of young (6-mo old) individuals with diabetes degrade prematurely and exhibit an appearance like that found in aged (20-mo old) nondiabetic mice. Exacerbated elastolysis and elastin-derived peptide production are characteristic elements, contributing to early aortic wall rigidity and hypertension development. Therefore, limiting this early aging could be a judicious therapeutic approach to reduce cardiovascular complications and premature death in patients with diabetes.
Assuntos
Aorta , Tecido Elástico , Matriz Extracelular , Síndrome Metabólica , Camundongos Endogâmicos C57BL , Rigidez Vascular , Animais , Tecido Elástico/metabolismo , Tecido Elástico/patologia , Rigidez Vascular/fisiologia , Camundongos , Aorta/metabolismo , Aorta/patologia , Aorta/fisiopatologia , Matriz Extracelular/metabolismo , Matriz Extracelular/patologia , Masculino , Síndrome Metabólica/metabolismo , Síndrome Metabólica/patologia , Síndrome Metabólica/fisiopatologia , Elastina/metabolismo , Colágeno/metabolismo , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Experimental/fisiopatologia , Envelhecimento/patologia , Envelhecimento/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patologia , Diabetes Mellitus Tipo 2/fisiopatologia , Senilidade Prematura/metabolismo , Senilidade Prematura/patologia , Senilidade Prematura/fisiopatologiaRESUMO
Barrier-to-autointegration factor (BAF/BANF) is a nuclear lamina protein essential for nuclear integrity, chromatin structure, and genome stability. Whereas complete loss of BAF causes lethality in multiple organisms, the A12T missense mutation of the BANF1 gene in humans causes a premature aging syndrome, called Néstor-Guillermo Progeria Syndrome (NGPS). Here, we report the first in vivo animal investigation of progeroid BAF, using CRISPR editing to introduce the NGPS mutation into the endogenous Drosophila baf gene. Progeroid BAF adults are born at expected frequencies, demonstrating that this BAF variant retains some function. However, tissue homeostasis is affected, supported by studies of the ovary, a tissue that depends upon BAF for stem cell survival and continuous oocyte production. We find that progeroid BAF causes defects in germline stem cell mitosis that delay anaphase progression and compromise chromosome segregation. We link these defects to decreased recruitment of centromeric proteins of the kinetochore, indicating dysfunction of cenBAF, a localized pool of dephosphorylated BAF produced by Protein Phosphatase PP4. We show that DNA damage increases in progenitor germ cells, which causes germ cell death due to activation of the DNA damage transducer kinase Chk2. Mitotic defects appear widespread, as aberrant chromosome segregation and increased apoptosis occur in another tissue. Together, these data highlight the importance of BAF in establishing centromeric structures critical for mitosis. Further, these studies link defects in cenBAF function to activation of a checkpoint that depletes progenitor reserves critical for tissue homeostasis, aligning with phenotypes of NGPS patients.
Assuntos
Drosophila , Progéria , Animais , Feminino , Humanos , Drosophila/metabolismo , Progéria/genética , Progéria/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas Nucleares/metabolismo , Centrômero/metabolismo , Homeostase/genéticaRESUMO
Hypoxia-induced intrauterine growth restriction increases the risk for cardiovascular, renal, and other chronic diseases in adults, representing thus a major public health problem. Still, not much is known about the fetal mechanisms that predispose these individuals to disease. Using a previously validated mouse model of fetal hypoxia and bottom-up proteomics, we characterize the response of the fetal kidney to chronic hypoxic stress. Fetal kidneys exhibit a dichotomous response to chronic hypoxia, comprising on the one hand cellular adaptations that promote survival (glycolysis, autophagy, and reduced DNA and protein synthesis), but on the other processes that induce a senescence-like phenotype (infiltration of inflammatory cells, DNA damage, and reduced proliferation). Importantly, chronic hypoxia also reduces the expression of the antiaging proteins klotho and Sirt6, a mechanism that is evolutionary conserved between mice and humans. Taken together, we uncover that predetermined aging during fetal development is a key event in chronic hypoxia, establishing a solid foundation for Barker's hypothesis of fetal programming of adult diseases. This phenotype is associated with a characteristic biomarker profile in tissue and serum samples, exploitable for detecting and targeting accelerated aging in chronic hypoxic human diseases.
Assuntos
Hipóxia Fetal , Sirtuínas , Envelhecimento , Animais , Desenvolvimento Fetal , Hipóxia , Camundongos , FenótipoRESUMO
The main objective of the study was to assess the occurrence of non-aids-related comorbidities typical of aging in people living with HIV diagnosis 20 years ago or more and under treatment with antiretroviral drugs for a long time. The associations between the same age group in people living with HIV with reported ART use 20 + years and people living with HIV with reported ART use between two and five years in relation to the risk of comorbidities studied, there was a predominance of metabolic alterations in the 50-60 and 60 + age groups (p < 0.003). The conclusion was that exists a higher risk of comorbidities associated with people living with HIV for more than 20 years, but the length of treatment did not necessarily influence this risk.
Assuntos
Envelhecimento , Comorbidade , Infecções por HIV , Humanos , Infecções por HIV/epidemiologia , Infecções por HIV/tratamento farmacológico , Pessoa de Meia-Idade , Masculino , Feminino , Adulto , Idoso , Fármacos Anti-HIV/uso terapêutico , Fatores de RiscoRESUMO
BACKGROUND: AI medical image analysis shows potential applications in research on premature aging and skin. The purpose of this study was to explore the mechanism of the Zuogui pill based on artificial intelligence medical image analysis on ovarian function enhancement and skin elasticity repair in rats with premature aging. MATERIALS AND METHODS: The premature aging rat model was established by using an experimental animal model. Then Zuogui pills were injected into the rats with premature aging, and the images were detected by an optical microscope. Then, through the analysis of artificial intelligence medical images, the image data is analyzed to evaluate the indicators of ovarian function. RESULTS: Through optical microscope image detection, we observed that the Zuogui pill played an active role in repairing ovarian tissue structure and increasing the number of follicles in mice, and Zuogui pill also significantly increased the level of progesterone in the blood of mice. CONCLUSION: Most of the ZGP-induced outcomes are significantly dose-dependent.
Assuntos
Senilidade Prematura , Inteligência Artificial , Medicamentos de Ervas Chinesas , Animais , Feminino , Ratos , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/administração & dosagem , Camundongos , Ovário/efeitos dos fármacos , Ovário/diagnóstico por imagem , Ratos Sprague-Dawley , Envelhecimento da Pele/efeitos dos fármacos , Modelos Animais de Doenças , Pele/efeitos dos fármacos , Pele/diagnóstico por imagem , Elasticidade/efeitos dos fármacos , Progesterona/sangue , Progesterona/farmacologia , Processamento de Imagem Assistida por Computador/métodosRESUMO
BACKGROUND: Individuals with Down syndrome (DS) experience premature aging. Whether accelerated aging involves changes in body composition parameters and is associated with early development of sarcopenia is unclear. AIMS: To compare parameters of body composition and the prevalence of sarcopenia between adults with DS and the general population. METHODS: Body composition was assessed by whole-body dual-energy X-ray absorptiometry (DXA). Fat mass (FMI) and skeletal mass indices (SMI) were calculated as the ratio between total body fat mass and appendicular lean mass and the square of height, respectively. Fat mass distribution was assessed by the android/gynoid fat ratio (A/G). Sarcopenia was defined according to the criteria and cut-points recommended by the European Working Group on Sarcopenia in Older People 2 (EWGSOP2). Data on age- and sex-matched non-DS controls were retrieved from the 2001-2002 National Health and Nutrition Examination Survey (NHANES) population. RESULTS: Sixty-four DS adults (mean age 37.2 ± 12.0 years, 20.3% women) were enrolled and compared with age- and sex-matched NHANES participants (n = 256), in a 1:4 ratio. FMI (7.96 ± 3.18 kg/m2 vs. 8.92 ± 4.83 kg/m2, p = 0.135), SMI (7.38 ± 1.01 kg/m2 vs. 7.46 ± 2.77 kg/m2, p = 0.825) and A/G (0.98 ± 0.17 vs. 1.01 ± 0.22, p = 0.115) were not significantly different between DS and control participants. When the sample was stratified by sex, women with DS had a higher FMI compared with their NHANES controls (10.16 ± 4.35 kg/m2 vs. 8.11 ± 4.29 kg/m2, p < 0.001), while men with DS had lower A/G ratio (1.04 ± 0.16 vs. 1.11 ± 0.22, p = 0.002). Sarcopenia was more frequent in individuals with DS than in controls (35.6% vs. 19.9%, p = 0.007). This association was stronger in men 40 years and older. CONCLUSIONS: Adults with DS have a higher prevalence of sarcopenia compared with the general population. This finding suggests that DS is associated with early muscle aging and calls for the design of interventions targeting the skeletal muscle to prevent or treat sarcopenia.
Assuntos
Síndrome de Down , Sarcopenia , Masculino , Humanos , Feminino , Idoso , Sarcopenia/complicações , Sarcopenia/epidemiologia , Sarcopenia/diagnóstico , Inquéritos Nutricionais , Estudos de Casos e Controles , Síndrome de Down/complicações , Índice de Massa Corporal , Composição Corporal , Absorciometria de FótonRESUMO
It is widely known that in economically developed countries there is an increase in the proportion of older people. However, the problem of the influence of territorial features of economic development on the rate of population aging is not sufficiently covered. The goal was to study the impact of economic development indicators (EDI) on the processes of premature aging of the population. The materials were statistical collections of the Ministry of Health of Russia and Russian Statistics Service for 2011-2019. The highest incidence was characteristic of cataracts and glaucoma. A direct correlation has been established between the EDI and the age-specific incidence index (ASII) of cataracts (r=0,31; p=0,00436). A group of regions with a high level of economic development was characterized by a higher value of ASII, which, as a rule, corresponds to the later development of the disease.
Assuntos
Senilidade Prematura , Humanos , Federação Russa/epidemiologia , Senilidade Prematura/epidemiologia , Senilidade Prematura/etiologia , Idoso , Catarata/epidemiologia , Catarata/diagnóstico , Incidência , Feminino , Masculino , Glaucoma/epidemiologia , Glaucoma/diagnóstico , Desenvolvimento Econômico/estatística & dados numéricos , Pessoa de Meia-IdadeRESUMO
From the age of 25-30, the likelihood of developing pathological processes associated with aging begins to increase. Age-associated diseases (AAD) are a heterogeneous group of pathologies that are more likely to develop as they age. Clinically, the early development of AAD is identical to premature aging with all the ensuing consequences. Timely targeted detection of AAD will slow down age-related processes. In order to study the peculiarities of age-related morbidity (by circulation), age-associated pathology, the study included 5 600 people with a newly diagnosed diagnosis who applied to the municipal polyclinic of St. Petersburg in 2017-2023. During the study, heterogeneity of the timing of the manifestation of AAD at the population level was found. In addition, the median age of patients was comparable to the value of the developed age-specific incidence index, which serves as a basis for continuing research in order to comprehensively assess the properties and limitations of the considered indicator.
Assuntos
Envelhecimento , Humanos , Federação Russa/epidemiologia , Incidência , Feminino , Masculino , Pessoa de Meia-Idade , Adulto , Idoso , Envelhecimento/fisiologia , Fatores Etários , Idoso de 80 Anos ou maisRESUMO
Metabolic syndrome is a group of disorders that are closely related to both the risk of developing type 2 diabetes mellitus and cardiovascular diseases, and generally leading to the phenomenon of premature aging of the body. Excessive accumulation of adipose tissue contributes to the development of chronic immune inflammation and oxidative stress, which are both precursors to various disorders, such as insulin resistance, arterial hypertension and dyslipidemia, but also trigger inflammatory processes in patients. An increasing number of studies support the importance of chronic immune inflammation in the pathogenesis of metabolic syndrome, as pro-inflammatory markers such as TNF-α, IL-1ß, IL-6, monocyte chemotactic protein-1 and growth of vascular endothelium. Among a wide range of cytokines, monocyte chemotactic protein-1 is considered one of the most important chemokines, which activates monocytes and other immune cells actively involved in inflammation. Another important point of chronic immune inflammation is its impact on the mental health of patients with metabolic syndrome. Increased levels of anxiety and depression are associated with levels of pro-inflammatory cytokines produced by adipose tissue, which ultimately has an adverse effect on the cognitive status of patients.
Assuntos
Biomarcadores , Inflamação , Síndrome Metabólica , Humanos , Síndrome Metabólica/metabolismo , Síndrome Metabólica/psicologia , Síndrome Metabólica/imunologia , Síndrome Metabólica/fisiopatologia , Inflamação/metabolismo , Inflamação/imunologia , Inflamação/psicologia , Biomarcadores/metabolismo , Biomarcadores/sangue , Idoso , Citocinas/metabolismo , Citocinas/sangue , Pessoa de Meia-Idade , Envelhecimento/psicologia , Envelhecimento/imunologia , Estresse Oxidativo/fisiologiaRESUMO
MAIN CONCLUSION: Rpf107 is involved in the infection process of rhizobia and the maintenance of symbiotic nitrogen fixation in black locust root nodules. The LURP-one related (LOR) protein family plays a pivotal role in mediating plant defense responses against both biotic and abiotic stresses. However, our understanding of its function in the symbiotic interaction between legumes and rhizobia remains limited. Here, Rpf107, a homolog of LOR, was identified in Robinia pseudoacacia (black locust). The subcellular localization of Rpf107 was analyzed, and its function was investigated using RNA interference (RNAi) and overexpression techniques. The subcellular localization assay revealed that Rpf107 was mainly distributed in the plasma membrane and nucleus. Rpf107 silencing prevented rhizobial infection and hampered plant growth. The number of infected cells in the nitrogen fixation zone of the Rpf107-RNAi nodules was also noticeably lower than that in the control nodules. Notably, Rpf107 silencing resulted in bacteroid degradation and the premature aging of nodules. In contrast, the overexpression of Rpf107 delayed the senescence of nodules and prolonged the nitrogen-fixing ability of nodules. These results demonstrate that Rpf107 was involved in the infection of rhizobia and the maintenance of symbiotic nitrogen fixation in black locust root nodules. The findings reveal that a member of the LOR protein family plays a role in leguminous root nodule symbiosis, which is helpful to clarify the functions of plant LOR protein family and fully understand the molecular mechanisms underlying legume-rhizobium symbiosis.
Assuntos
Fabaceae , Rhizobium , Robinia , Robinia/genética , Nódulos Radiculares de Plantas/metabolismo , Simbiose/genética , Genes vif , Fixação de Nitrogênio/genética , Rhizobium/fisiologia , Fabaceae/genética , Proteínas de Plantas/metabolismoRESUMO
Cardiovascular diseases, atherosclerosis, and strokes are the most common causes of death in patients with Hutchinson-Gilford progeria syndrome (HGPS). The LMNA variant c.1824C > T accounts for ~ 90% of HGPS cases. The detailed molecular mechanisms of Lamin A in the heart remain elusive due to the lack of appropriate in vitro models. We hypothesize that HGPS patient's induced pluripotent stem cell (iPSC)-derived cardiomyocytes (iCMCs) will provide a model platform to study the cardio-pathologic mechanisms associated with HGPS. To elucidate the effects of progerin in cardiomyocytes, we first obtained skin fibroblasts (SFs) from a de-identified HGPS patient (hPGP1, proband) and both parents from the Progeria Research Foundation. Through Sanger sequencing and restriction fragment length polymorphism, with the enzyme EciI, targeting Lamin A, we characterized hPGP1-SFs as heterozygous mutants for the LMNA variant c.1824 C > T. Additionally, we performed LMNA exon 11 bisulfite sequencing to analyze the methylation status of the progeria cells. Furthermore, we reprogrammed the three SFs into iPSCs and differentiated them into iCMCs, which gained a beating on day 7. Through particle image velocimetry analysis, we found that hPGP1-iCMCs had an irregular contractile function and decreased cardiac-specific gene and protein expressions by qRT-PCR and Western blot. Our progeria-patient-derived iCMCs were found to be functionally and structurally defective when compared to normal iCMCs. This in vitro model will help in elucidating the role of Lamin A in cardiac diseases and the cardio-pathologic mechanisms associated with progeria. It provides a new platform for researchers to study novel treatment approaches for progeria-associated cardiac diseases.
Assuntos
Cardiopatias , Progéria , Humanos , Progéria/genética , Progéria/metabolismo , Progéria/patologia , Lamina Tipo A/genética , Lamina Tipo A/metabolismo , Miócitos Cardíacos/metabolismo , Diferenciação CelularRESUMO
BACKGROUND: Difficulty performing basic daily activities such as bathing and dressing ("functional impairment") affects more than 15% of middle-aged people, and this proportion is increasing. Little is known about the experiences and needs of individuals who develop functional impairment in middle age. OBJECTIVE: To examine the experiences and needs of adults who developed functional impairment in middle age. DESIGN: Qualitative study using semi-structured interviews. PARTICIPANTS: Forty patients aged 50-64 years who developed functional impairment in middle age, recruited from four primary care clinics in San Francisco. APPROACH: Interviews included open-ended questions about participants' daily life, ability to perform activities of daily living (ADLs), and needs related to functional impairment. We analyzed interviews using qualitative thematic analysis. KEY RESULTS: Interviews revealed several themes related to the psychosocial and physical impacts of developing functional impairment in middle age. Participants noted that losses associated with functional impairment, such as loss of independence, control, and social roles, caused conflict in their sense of identity. To cope with these losses, participants used strategies including acceptance, social comparison, adjusting standards, and engaging in valued life activities. Participants reflected on the intersection of their functional impairment with the aging process, noting that their impairments seemed premature compared to the more "natural" aging process in older adults. In terms of physical impacts, participants described how a lack of accommodations in the built environment exacerbated their impairments. While participants used behavioral strategies to overcome these challenges, unmet needs remained, resulting in downstream physical and psychological impacts including safety risks, falls, frustration, and fear. CONCLUSIONS: Unmet psychosocial and physical needs were common among middle-aged adults with functional impairment and led to negative downstream effects. Eliciting and addressing unmet needs may help mitigate downstream health consequences for this growing population, optimizing function and quality of life.
Assuntos
Atividades Cotidianas , Pessoas com Deficiência , Pessoa de Meia-Idade , Humanos , Idoso , Qualidade de Vida/psicologia , São FranciscoRESUMO
Senescence is a complex cell state characterized by stable cell cycle arrest and a unique secretory pattern known as the senescence-associated secretory phenotype (SASP). The SASP factors, which are heterogeneous and tissue specific, normally include chemokines, cytokines, growth factors, adhesion molecules, and lipid components that can lead to multiple age-associated disorders by eliciting local and systemic consequences. The skeleton is a highly dynamic organ that changes constantly in shape and composition. Senescent cells in bone and bone marrow produce diverse SASP factors that induce alterations of the skeleton through paracrine effects. Herein, we refer to bone cell-associated SASP as "bone-SASP." In this review, we describe current knowledge of cellular senescence and SASP, focusing on the role of senescent cells in mediating bone pathologies during natural aging and premature aging syndromes. We also summarize the role of cellular senescence and the bone-SASP in glucocorticoids-induced bone damage. In addition, we discuss the role of bone-SASP in the development of osteoarthritis, highlighting the mechanisms by which bone-SASP drives subchondral bone changes in metabolic syndrome-associated osteoarthritis.
Assuntos
Osso e Ossos , Senescência Celular , Osso e Ossos/metabolismo , Osteócitos/metabolismo , Citocinas/metabolismo , FenótipoRESUMO
Atypical progeroid syndromes (APS) are premature aging syndromes caused by pathogenic LMNA missense variants, associated with unaltered expression levels of lamins A and C, without accumulation of wild-type or deleted prelamin A isoforms, as observed in Hutchinson-Gilford progeria syndrome (HGPS) or HGPS-like syndromes. A specific LMNA missense variant, (p.Thr528Met), was previously identified in a compound heterozygous state in patients affected by APS and severe familial partial lipodystrophy, whereas heterozygosity was recently identified in patients affected by Type 2 familial partial lipodystrophy. Here, we report four unrelated boys harboring homozygosity for the p.Thr528Met, variant who presented with strikingly homogeneous APS clinical features, including osteolysis of mandibles, distal clavicles and phalanges, congenital muscular dystrophy with elevated creatine kinase levels, and major skeletal deformities. Immunofluorescence analyses of patient-derived primary fibroblasts showed a high percentage of dysmorphic nuclei with nuclear blebs and typical honeycomb patterns devoid of lamin B1. Interestingly, in some protrusions emerin or LAP2α formed aberrant aggregates, suggesting pathophysiology-associated clues. These four cases further confirm that a specific LMNA variant can lead to the development of strikingly homogeneous clinical phenotypes, in these particular cases a premature aging phenotype with major musculoskeletal involvement linked to the homozygous p.Thr528Met variant.
Assuntos
Senilidade Prematura , Disostoses , Lipodistrofia Parcial Familiar , Distrofias Musculares , Progéria , Humanos , Síndrome , Lipodistrofia Parcial Familiar/complicações , Clavícula/metabolismo , Clavícula/patologia , Mutação , Progéria/patologia , Disostoses/complicações , Lamina Tipo A/genéticaRESUMO
As the limits of fetal viability have increased over the past 30 years, there has been a growing body of evidence supporting the idea that chronic disease should be taken into greater consideration in addition to survival after preterm birth. Accumulating evidence also suggests there is early onset of biologic aging after preterm birth. Similarly, chronic kidney disease (CKD) is also associated with a phenotype of advanced biologic age which exceeds chronologic age. Yet, significant knowledge gaps remain regarding the link between premature biologic age after preterm birth and kidney disease. This review summarizes the four broad pillars of aging, the evidence of premature aging following preterm birth, and in the setting of CKD. The aim is to provide additional plausible biologic mechanisms to explore the link between preterm birth and CKD. There is a need for more research to further elucidate the biologic mechanisms of the premature aging paradigm and kidney disease after preterm birth. Given the emerging research on therapies for premature aging, this paradigm could create pathways for prevention of advanced CKD.
RESUMO
Penttinen type of premature aging syndrome is an autosomal-dominant disorder that can be caused by the c.1994T>A pVal665Ala pathogenic variant in platelet-derived growth factor receptor-B (PDGFRB). Imatinib, a receptor tyrosine kinase (RTK) inhibitor, has been used in Penttinen syndrome (PS) patients with good results. A 21-year-old male presented shortly after birth with a prematurely aged appearance with distinctive facial features and cutaneous atrophy with hypertrophic scar-like lesions. Generalized brachydactyly with acro-osteolysis was observed. Flexion contractures limited his daily activities. Cognitive impairment was not present. Genetic testing found a heterozygous variant c.1994T>A pVal665Ala in exon 14 of PDGFRB. A diagnosis of PS was made and imatinib treatment was started with partial response. After lack of further improvement, in vitro molecular studies with imatinib and dasatinib showed that the Val665Ala variant had greater sensitivity to dasatinib than imatinib. This was seen examining levels of P-PDGFRB directly and on downstream ligands P-AKT and P-STAT. Improved clinical response was observed after treatment with dasatinib. We report a new case of PS with clinical and molecular response to dasatinib after incomplete response to imatinib. Our work provides further molecular and clinical evidence of RTK inhibitors' efficacy in this rare disorder.
Assuntos
Acro-Osteólise , Anormalidades da Pele , Acro-Osteólise/genética , Dasatinibe/uso terapêutico , Humanos , Mesilato de Imatinib/uso terapêutico , Deformidades Congênitas dos Membros , Masculino , Progéria , Inibidores de Proteínas Quinases/uso terapêutico , Receptor beta de Fator de Crescimento Derivado de Plaquetas/genética , Adulto JovemRESUMO
Werner syndrome (WS) is an extremely rare, autosomal recessive segmental progeroid disorder caused by biallelic pathogenic variants in the WRN, which encodes a multifunctional nuclear protein that belongs to the RecQ family of DNA helicases. Despite extensive research on WS in the last years, the population-specific mutational spectrum still needs to be elucidated. Moreover, there is an evident lack of detailed clinical descriptions accompanied with photographs of affected individuals. Here, we report a consanguineous Lebanese family in whom we identified a pathogenic homozygous nonsense variant c.1111G>T, p.Glu371* in the WRN. The index individual, at the age of 54 years, was suspected to have WS due to a history of early-onset cataracts, premature hair loss and graying, chronic nonhealing leg ulcers, Achilles' tendon calcifications, type 2 diabetes mellitus, dyslipidemia, hypothyroidism, and premature coronary artery disease. His four sisters, three of which deceased in the fifth decade, had clinical signs suggestive of WS. Moreover, his daughter, aged 23 years, had short stature, hair loss and flat feet. Taken together, we report a detailed clinical course of disease in several affected members of a consanguineous family, which is additionally documented by photographs.
Assuntos
Diabetes Mellitus Tipo 2 , Síndrome de Werner , Alopecia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , RecQ Helicases/genética , Síndrome de Werner/diagnóstico , Síndrome de Werner/genética , Síndrome de Werner/metabolismo , Helicase da Síndrome de Werner/genética , Helicase da Síndrome de Werner/metabolismo , Adulto JovemRESUMO
Down syndrome (DS) induces a variable phenotype including intellectual disabilities and early development of Alzheimer's disease (AD). Moreover, individuals with DS display accelerated aging that affects diverse organs, among them the brain. The Ts65Dn mouse is the most widely used model to study DS. Progressive loss of cholinergic neurons is one of the hallmarks of AD present in DS and in the Ts65Dn model. In this study, we quantify the number of cholinergic neurons in control and Ts65Dn mice, observing a general reduction in their number with age but in particular, a greater loss in old Ts65Dn mice. Increased expression of the m1 muscarinic receptor in the hippocampus counteracts this loss. Cholinergic neurons in the Ts65Dn mice display overexpression of the early expression gene c-fos and an increase in the expression of ß-galactosidase, a marker of senescence. A possible mechanism for senescence induction could be phosphorylation of the transcription factor FOXO1 and its retention in the cytoplasm, which we are able to confirm in the Ts65Dn model. In our study, using Ts65Dn mice, we observe increased cholinergic activity, which induces a process of early senescence that culminates in the loss of these neurons.
Assuntos
Doença de Alzheimer , Síndrome de Down , Doença de Alzheimer/metabolismo , Animais , Colinérgicos , Modelos Animais de Doenças , Camundongos , Camundongos TransgênicosRESUMO
Human RecQ helicases play diverse roles in the maintenance of genomic stability. Inactivating mutations in 3 of the 5 human RecQ helicases are responsible for the pathogenesis of Werner syndrome (WS), Bloom syndrome (BS), Rothmund-Thomson syndrome (RTS), RAPADILINO, and Baller-Gerold syndrome (BGS). WS, BS, and RTS patients are at increased risk for developing many age-associated diseases including cancer. Mutations in RecQL1 and RecQL5 have not yet been associated with any human diseases so far. In terms of disease outcome, RecQL4 deserves special attention because mutations in RecQL4 result in 3 autosomal recessive syndromes (RTS type II, RAPADILINO, and BGS). RecQL4, like other human RecQ helicases, has been demonstrated to play a crucial role in the maintenance of genomic stability through participation in diverse DNA metabolic activities. Increased incidence of osteosarcoma in RecQL4-mutated RTS patients and elevated expression of RecQL4 in sporadic cancers including osteosarcoma suggest that loss or gain of RecQL4 expression is linked with cancer susceptibility. In this review, current and future perspectives are discussed on the potential use of RecQL4 as a novel cancer therapeutic target.