RESUMO
Generalized lipodystrophy is a feature of various hereditary disorders, often leading to a progeroid appearance. In the present study we identified a missense and a frameshift variant in a compound heterozygous state in SUPT7L in a boy with intrauterine growth retardation, generalized lipodystrophy, and additional progeroid features. SUPT7L encodes a component of the transcriptional coactivator complex STAGA. By transcriptome sequencing, we showed the predicted missense variant to cause aberrant splicing, leading to exon truncation and thereby to a complete absence of SUPT7L in dermal fibroblasts. In addition, we found altered expression of genes encoding DNA repair pathway components. This pathway was further investigated and an increased rate of DNA damage was detected in proband-derived fibroblasts and genome-edited HeLa cells. Finally, we performed transient overexpression of wildtype SUPT7L in both cellular systems, which normalizes the number of DNA damage events. Our findings suggest SUPT7L as a novel disease gene and underline the link between genome instability and progeroid phenotypes.
Assuntos
Retardo do Crescimento Fetal , Lipodistrofia Generalizada Congênita , Fatores de Transcrição , Humanos , Masculino , Dano ao DNA , Reparo do DNA/genética , Retardo do Crescimento Fetal/genética , Fibroblastos/metabolismo , Células HeLa , Lipodistrofia/genética , Lipodistrofia Generalizada Congênita/genética , Mutação com Perda de Função , Mutação de Sentido Incorreto , Fatores de Transcrição/genéticaRESUMO
Marbach-Rustad progeroid syndrome is an extremely rare disease caused by a heterozygous variant in the LEMD2 gene. To date, only two patients and one LEMD2 pathogenic variant have been reported in Marbach-Rustad progeroid syndrome. Here we describe the third case of Marbach-Rustad progeroid syndrome worldwide, which is also the first case in China. The proband was affected with premature birth, failed to thrive, facial abnormalities, feeding difficulties, skull defects and delayed motor milestones, but had a normal intelligence and speech. Whole exome sequencing (WES) initially did not find a phenotype-causing variant when the proband was 1 year of age. The reanalysis of WES data 4 years later revealed the proband harbored a de novo heterozygous c.1436C>T(p.Ser479Phe) variant in the LEMD2 gene, which is known responsible for Marbach-Rustad progeroid syndrome. Sanger sequencing confirmed the presence of this variant in the proband and absence in his parents and two elder sisters. Our study provides accurate clinical diagnosis for the proband and adds a new patient with Marbach-Rustad progeroid syndrome. Our study suggests the LEMD2 c.1436C>T(p.Ser479Phe) variant as a hotspot. Our work also indicates reanalysis of WES data of negative cases might identify pathogenic variant and improve diagnostic efficiency.
Assuntos
Proteínas de Membrana , Proteínas Nucleares , Humanos , China , Sequenciamento do Exoma , Heterozigoto , Mutação , Fenótipo , Feminino , LactenteRESUMO
PURPOSE: The differential diagnosis of lipodystrophy involves other disorders characterized by severe fat loss and may be sometimes challenging. Owing to the rarity of lipodystrophy, it is relevant to search for tools and assays that differentiate it from other diseases that may mimic it. We conducted a study on leptin and high molecular weight (HMW) adiponectin serum concentrations in a series of patients diagnosed with lipodystrophy and compared them with those found in anorexia nervosa, one of the illnesses that may be cause of a missed diagnosis of lipodystrophy. METHODS: Leptin and HMW adiponectin serum concentrations were measured in six patients diagnosed with generalized lipodystrophy (GL), six with progeroid syndromes (PS), 13 with familial partial lipodystrophy type 1 (FPLD1, Kobberling syndrome), 10 with familial partial lipodystrophy type 2 (FPLD2, Dunnigan syndrome), 18 with acquired partial lipodystrophy (APL) and 12 affected by anorexia nervosa (AN). Measurements were compared to those obtained in 12 normal weight healthy subjects. RESULTS: Serum leptin concentrations were reduced to a similar degree in GL, PS and AN, proportionally to the extent of fat loss. Serum concentrations of HMW adiponectin were found extremely low in patients with GL and PS, while comparable to normal weight subjects in patients with AN. CONCLUSION: Serum HMW adiponectin can be regarded as a useful tool to discriminate between generalized lipodystrophy syndromes (including PS) and AN.
Assuntos
Adiponectina , Anorexia Nervosa , Leptina , Humanos , Anorexia Nervosa/sangue , Anorexia Nervosa/diagnóstico , Adiponectina/sangue , Feminino , Adulto , Diagnóstico Diferencial , Adolescente , Leptina/sangue , Masculino , Adulto Jovem , Lipodistrofia Generalizada Congênita/sangue , Lipodistrofia Generalizada Congênita/diagnóstico , Lipodistrofia/sangue , Lipodistrofia/diagnóstico , Criança , Biomarcadores/sangue , Pessoa de Meia-Idade , Estudos de Casos e ControlesRESUMO
Until recently, mandibuloacral dysplasia (MAD) with type A and type B lipodystrophy was the first to come to mind in the association of mandibular hypoplasia, lipodystrophy, and acro-osteolysis. However, it has recently been added to the differential diagnosis of MAD, a newly defined syndrome, called MDPS. MDPS is a skeletal dysplasia characterized by postnatal growth retardation, hypotonia, generalized lipodystrophy, skin changes, progeroid traits, and dysmorphic facial features, including prominent eyes, long pinched nose, mandibular hypoplasia, and a small mouth. Biallelic null variants of the MTX2 gene are responsible for this syndrome. We performed whole-exome sequencing (WES) in a 6-year-old patient with skeletal dysplasia. WES revealed a novel homozygous c.543+1G>T splice site variant in the MTX2 gene. We also extracted total RNA from peripheral blood and used reverse transcription-polymerase chain reaction to generate cDNA. Sanger sequencing from cDNA showed that exon 8 of MTX2 was skipped. This study adds to the genetics and phenotype of MDPS and underlines the importance of comprehensive clinical and molecular research.
Assuntos
Acro-Osteólise , Lipodistrofia , Micrognatismo , Humanos , Mutação , Lipodistrofia/diagnóstico , Lipodistrofia/genética , Acro-Osteólise/genética , Homozigoto , Éxons/genética , Micrognatismo/genética , SíndromeRESUMO
Age-related gastrointestinal decline contributes to whole-organism frailty and mortality. Genistein is known to have beneficial effects on age-related diseases, but its precise role in homeostasis of the aging gut remains to be elucidated. Here, wild-type aging mice and Zmpste24-/- progeroid mice were used to investigate the role of genistein in lifespan and homeostasis of the aging gut in mammals. A series of longitudinal, clinically relevant measurements were performed to evaluate the effect of genistein on healthspan. It was found that dietary genistein promoted a healthier and longer life and was associated with a decrease in the levels of systemic inflammatory cytokines in aging mice. Furthermore, dietary genistein ameliorated gut dysfunctions, such as intestinal inflammation, leaky gut, and impaired epithelial regeneration. A distinct genistein-mediated alteration in gut microbiota was observed by increasing Lachnospira abundance and short-chain fatty acid (SCFA) production. Further fecal microbiota transplantation and dirty cage sharing experiments indicated that the gut microbiota from genistein-fed mice rejuvenated the aging gut and extended the lifespan of progeroid mice. It was demonstrated that genistein-associated SCFAs alleviated tumor necrosis factor alpha-induced intestinal organoid damage. Moreover, genistein-associated propionate promoted regulatory T cell-derived interleukin 10 production, which alleviated macrophage-derived inflammation. This study provided the first data, to the authors' knowledge, indicating that dietary genistein modulates homeostasis in the aging gut and extends the healthspan and lifespan of aging mammals. Moreover, the existence of a link between genistein and the gut microbiota provides a rationale for dietary interventions against age-associated frailty.
Assuntos
Fragilidade , Microbioma Gastrointestinal , Camundongos , Animais , Longevidade , Genisteína/farmacologia , Ácidos Graxos Voláteis/farmacologia , Envelhecimento , Inflamação , Homeostase , Camundongos Endogâmicos C57BL , MamíferosRESUMO
PURPOSE: In this study we aimed to identify the molecular genetic cause of a progressive multisystem disease with prominent lipodystrophy. METHODS: In total, 5 affected individuals were investigated using exome sequencing. Dermal fibroblasts were characterized using RNA sequencing, proteomics, immunoblotting, immunostaining, and electron microscopy. Subcellular localization and rescue studies were performed. RESULTS: We identified a lipodystrophy phenotype with a typical facial appearance, corneal clouding, achalasia, progressive hearing loss, and variable severity. Although 3 individuals showed stunted growth, intellectual disability, and died within the first decade of life (A1, A2, and A3), 2 are adults with normal intellectual development (A4 and A5). All individuals harbored an identical homozygous nonsense variant affecting the retention and splicing complex component BUD13. The nucleotide substitution caused alternative splicing of BUD13 leading to a stable truncated protein whose expression positively correlated with disease expression and life expectancy. In dermal fibroblasts, we found elevated intron retention, a global reduction of spliceosomal proteins, and nuclei with multiple invaginations, which were more pronounced in A1, A2, and A3. Overexpression of both BUD13 isoforms normalized the nuclear morphology. CONCLUSION: Our results define a hitherto unknown syndrome and show that the alternative splice product converts a loss-of-function into a hypomorphic allele, thereby probably determining the severity of the disease and the survival of affected individuals.
Assuntos
Processamento Alternativo , Lipodistrofia , Proteínas de Ligação a RNA/genética , Criança , Deficiências do Desenvolvimento/genética , Humanos , Íntrons , Lipodistrofia/genética , Splicing de RNARESUMO
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
We report an individual from Brazil with SHORT syndrome. The term SHORT stands for its common characteristics: short stature (S), hyperextensibility of joints, and/or inguinal hernia (H), ocular depression (O), Rieger anomaly (R), and teething delay (T). In addition to most of the clinical signs previously described in SHORT syndrome, the patient presented here also shows microcephaly and intellectual disability. Diagnosis was confirmed by exome sequencing revealing a novel heterozygous variant c.1456G>A (p.Ala486Thr) at PIK3R1. Human recombinant growth hormone (r-hGH) therapy was administered prior to diagnosis; however, the use of r-hGH may have had a role in anticipating and worsening the glucose metabolic profile in the patient, as previously described. This article contributes to providing a better understanding of the SHORT syndrome genotype and its correlation with the phenotype, by comparing with it other reported cases.
Assuntos
Doenças Metabólicas , Nefrocalcinose , Adulto , Brasil , Classe Ia de Fosfatidilinositol 3-Quinase/genética , Transtornos do Crescimento , Humanos , Hipercalcemia , Nefrocalcinose/diagnóstico , Nefrocalcinose/genética , FenótipoRESUMO
PURPOSE: SARS-CoV-2 infection may cause varying degrees of cardiac injury and the presence of underlying cardiovascular morbidities contributes to the frequency and severity of occurrence of this complication. Lipodystrophy syndromes are frequently characterized by severe metabolic derangements that represent relevant cardiovascular risk factors. Besides causing lipodystrophy, mutations in the lamin A/C (LMNA) gene can lead to a wide spectrum of tissue-specific disorders including cardiac involvement. METHODS AND RESULTS: We herein examine the case of two patients affected by atypical progeroid syndrome and partial lipodystrophy due to a heterozygous missense LMNA mutation c.1045 C > T (p.R349W) who presented initially with mild COVID-19 and developed severe cardiovascular complications within few weeks of SARS-CoV-2 infection. Before being infected with SARS-CoV-2, our patients had cardiovascular morbidities (mild mitral regurgitation in one patient, ischemic heart disease with bifascicular block in the other patient) in adjunct to cardiovascular risk factors, but the SARS-CoV-2 infection contributed to quickly and significantly decompensate their balance. CONCLUSION: These findings warn that patients affected by LMNA p.R349W mutation and likely other LMNA mutations associated with cardiovascular morbidity should be considered at extremely elevated risk of post-acute cardiological manifestations and should therefore undergo a vigilant follow-up after SARS-CoV-2 infection. Both patients developed COVID-19 before the specific vaccination was available to them and this unfortunate situation should remark the importance of vaccination coverage against SARS-CoV-2 infection for all patients affected by lipodystrophy, especially those with underlying comorbidities.
Assuntos
COVID-19 , Lipodistrofia , COVID-19/complicações , Humanos , Lamina Tipo A/genética , Mutação , SARS-CoV-2/genéticaRESUMO
Wiedemann-Rautenstrauch syndrome (WRS), also known as neonatal progeroid syndrome, is a rare disorder of unknown etiology. It has been proposed to be autosomal-recessive and is characterized by variable clinical features, such as intrauterine growth restriction and poor postnatal weight gain, characteristic facial features (triangular appearance to the face, convex nasal profile or pinched nose, and small mouth), widened fontanelles, pseudohydrocephalus, prominent scalp veins, lipodystrophy, and teeth abnormalities. A previous report described a single WRS patient with bi-allelic truncating and splicing variants in POLR3A. Here we present seven additional infants, children, and adults with WRS and bi-allelic truncating and/or splicing variants in POLR3A. POLR3A, the largest subunit of RNA polymerase III, is a DNA-directed RNA polymerase that transcribes many small noncoding RNAs that regulate transcription, RNA processing, and translation. Bi-allelic missense variants in POLR3A have been associated with phenotypes distinct from WRS: hypogonadotropic hypogonadism and hypomyelinating leukodystrophy with or without oligodontia. Our findings confirm the association of bi-allelic POLR3A variants with WRS, expand the clinical phenotype of WRS, and suggest specific POLR3A genotypes associated with WRS and hypomyelinating leukodystrophy.
Assuntos
Retardo do Crescimento Fetal/genética , Variação Genética/genética , Perda de Heterozigosidade/genética , Progéria/genética , RNA Polimerase III/genética , Adolescente , Adulto , Alelos , Pré-Escolar , Feminino , Genótipo , Humanos , Fenótipo , Adulto JovemRESUMO
Progeroid disorders make up a heterogeneous group of very rare hereditary diseases characterized by clinical signs that often mimic physiological aging in a premature manner. Apart from Hutchinson-Gilford progeria syndrome, one of the best-investigated progeroid disorders, a wide spectrum of other premature aging phenotypes exist, which differ significantly in their clinical presentation and molecular pathogenesis. Next-generation sequencing (NGS)-based approaches have made it feasible to determine the molecular diagnosis in the early stages of a disease. Nevertheless, a broad clinical knowledge on these disorders and their associated symptoms is still fundamental for a comprehensive patient management and for the interpretation of variants of unknown significance from NGS data sets. This review provides a detailed overview on characteristic clinical features and underlying molecular genetics of well-known as well as only recently identified premature aging disorders and also highlights novel findings towards future therapeutic options.
Assuntos
Senilidade Prematura/genética , Envelhecimento/genética , Progéria/genética , Envelhecimento/patologia , Senilidade Prematura/diagnóstico , Senilidade Prematura/fisiopatologia , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Patologia Molecular , Fenótipo , Progéria/diagnóstico , Progéria/fisiopatologiaRESUMO
Mandibular hypoplasia, deafness, progeroid feature, and lipodystrophy syndrome (MDPL, MIM# 615381) is an extremely rare and recently recognized early adult onset of progeroid syndrome, with features of generalized lipodystrophy, dysmorphic features, telangiectasia, early onset hearing loss, insulin resistance, and dyslipidemia. Here, we present a 31-year-old Chinese woman with MDPL, harboring the recurrent pathogenic variant p.(Ser605del) in POLD1, illustrating the evolving manifestations of this premature aging disorder from infancy to adulthood.
Assuntos
Anormalidades Múltiplas/genética , DNA Polimerase III/genética , Lipodistrofia Generalizada Congênita/genética , Micrognatismo/genética , Progéria/genética , Adulto , DNA Polimerase III/deficiência , Surdez/genética , Progressão da Doença , Dislipidemias/genética , Feminino , Genes Dominantes , Humanos , Resistência à Insulina/genética , Miopia/genética , Síndrome , Telangiectasia/genética , Magreza/genéticaRESUMO
Several inborn errors of metabolism show cutis laxa as a highly recognizable feature. One group of these metabolic cutis laxa conditions is autosomal recessive cutis laxa type 2 caused by defects in v-ATPase components or the mitochondrial proline cycle. Besides cutis laxa, muscular hypotonia and cardiac abnormalities are hallmarks of autosomal recessive cutis laxa type 2D (ARCL2D) due to pathogenic variants in ATP6V1A encoding subunit A of the v-ATPase. Here, we report on three affected individuals from two families with ARCL2D in whom we performed whole exome and Sanger sequencing. We performed functional studies in fibroblasts from one individual, summarized all known probands' clinical, molecular, and biochemical features and compared them, also to other metabolic forms of cutis laxa. We identified novel missense and the first nonsense variant strongly affecting ATP6V1A expression. All six ARCL2D affected individuals show equally severe cutis laxa and dysmorphism at birth. While for one no information was available, two died in infancy and three are now adolescents with mild or absent intellectual disability. Muscular weakness, ptosis, contractures, and elevated muscle enzymes indicated a persistent myopathy. In cellular studies, a fragmented Golgi compartment, a delayed Brefeldin A-induced retrograde transport and glycosylation abnormalities were present in fibroblasts from two individuals. This is the second and confirmatory report on pathogenic variants in ATP6V1A as the cause of this extremely rare condition and the first to describe a nonsense allele. Our data highlight the tremendous clinical variability of ATP6V1A related phenotypes even within the same family.
Assuntos
Cútis Laxa/genética , Mutação de Sentido Incorreto , ATPases Vacuolares Próton-Translocadoras/genética , Adolescente , Alelos , Estudos de Casos e Controles , Fibroblastos/metabolismo , Complexo de Golgi/metabolismo , Humanos , Lactente , Recém-Nascido , Deficiência Intelectual/genética , Masculino , Linhagem , FenótipoRESUMO
Werner syndrome, also called adult progeria, is a heritable autosomal recessive human disorder characterized by the premature onset of numerous age-related diseases including juvenile cataracts, dyslipidemia, diabetes mellitus (DM), osteoporosis, atherosclerosis, and cancer. Werner syndrome is a segmental progeroid syndrome whose presentation resembles accelerated aging. The most common causes of death for WS patients are atherosclerosis and cancer. A 40-year-old female presented with short stature, bird-like facies, canities with alopecia, scleroderma-like skin changes, and non-healing foot ulcers. The patient reported a history of delayed puberty, abortion, hypertriglyceridemia, and juvenile cataracts. A clinical diagnosis of WS was made and subsequently confirmed. We discovered two WRN gene mutations in the patient, Variant 1 was the most common WRN mutation, nonsense mutation (c.1105C>T:p.R369Ter) in exon 9, which caused a premature termination codon (PTC) at position 369. Variant 2 was a frameshift mutation (c.1134delA:p.E379KfsTer5) in exon 9, which caused a PTC at position 383 and has no published reports describing. Patients with WS can show a wide variety of clinical and biological manifestations in endocrine-metabolic systems (DM, thyroid dysfunction, and hyperlipidemia). Doctors must be cognizant of early manifestations of WS and treatment options.
Assuntos
Doenças Ósseas Metabólicas/fisiopatologia , Diabetes Mellitus Tipo 2/metabolismo , Fígado Gorduroso/fisiopatologia , Hipertrigliceridemia/metabolismo , Hipotireoidismo/metabolismo , Síndrome de Werner/metabolismo , Aborto Habitual/fisiopatologia , Tecido Adiposo/diagnóstico por imagem , Adulto , Alopecia/fisiopatologia , Composição Corporal , Doenças Ósseas Metabólicas/diagnóstico por imagem , Catarata/fisiopatologia , Códon sem Sentido , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/fisiopatologia , Pé Diabético/etiologia , Pé Diabético/fisiopatologia , Fígado Gorduroso/diagnóstico por imagem , Feminino , Mutação da Fase de Leitura , Humanos , Hipotireoidismo/fisiopatologia , Gordura Intra-Abdominal/diagnóstico por imagem , Útero/anormalidades , Síndrome de Werner/diagnóstico , Síndrome de Werner/genética , Síndrome de Werner/fisiopatologia , Helicase da Síndrome de Werner/genéticaRESUMO
A series of simplex cases have been reported under various diagnoses sharing early aging, especially evident in congenitally decreased subcutaneous fat tissue and sparse hair, bone dysplasia of the skull and fingers, a distinctive facial gestalt, and prenatal and postnatal growth retardation. For historical reasons, we suggest naming the entity Fontaine syndrome. Exome sequencing of four unrelated affected individuals showed that all carried the de novo missense variant c.649C>T (p.Arg217Cys) or c.650G>A (p.Arg217His) in SLC25A24, a solute carrier 25 family member coding for calcium-binding mitochondrial carrier protein (SCaMC-1, also known as SLC25A24). SLC25A24 allows an electro-neutral and reversible exchange of ATP-Mg and phosphate between the cytosol and mitochondria, which is required for maintaining optimal adenine nucleotide levels in the mitochondrial matrix. Molecular dynamic simulation studies predict that p.Arg217Cys and p.Arg217His narrow the substrate cavity of the protein and disrupt transporter dynamics. SLC25A24-mutant fibroblasts and cells expressing p.Arg217Cys or p.Arg217His variants showed altered mitochondrial morphology, a decreased proliferation rate, increased mitochondrial membrane potential, and decreased ATP-linked mitochondrial oxygen consumption. The results suggest that the SLC25A24 mutations lead to impaired mitochondrial ATP synthesis and cause hyperpolarization and increased proton leak in association with an impaired energy metabolism. Our findings identify SLC25A24 mutations affecting codon 217 as the underlying genetic cause of human progeroid Fontaine syndrome.
Assuntos
Envelhecimento/genética , Antiporters/genética , Doenças do Desenvolvimento Ósseo/genética , Proteínas de Ligação ao Cálcio/genética , Proteínas Mitocondriais/genética , Mutação/genética , Adenina/metabolismo , Trifosfato de Adenosina/metabolismo , Citosol/metabolismo , Feminino , Morte Fetal , Fibroblastos/metabolismo , Humanos , Lactente , Recém-Nascido , Masculino , Potencial da Membrana Mitocondrial/genética , Mitocôndrias/genética , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Simulação de Dinâmica Molecular , Oxigênio/metabolismo , Fosfatos/metabolismo , SíndromeRESUMO
Mutations in the gene LMNA cause a wide spectrum of diseases that are now referred to laminopathies, such as muscular dystrophies, cardiomyopathies, and progeroid syndromes. Atypical progeroid syndrome (APS) is a type of progeroid syndrome mainly associated with LMNA mutations. Abnormal skeletal features associated with APS, such as osteoporosis and acroosteolysis, are rarely reported, and recurrent fractures have never been documented. We present a 16-year-old Chinese male patient with the typical features of APS, such as progeroid manifestations, cutaneous mottled hyperpigmentation, generalized lipodystrophy, and severe metabolic complications. The patient has also been detected with some rare and severe skeletal features, such as severe osteoporosis, generalized thinning of cortical bone, and recurrent femoral fractures. Genetic mutation detection in the LMNA gene revealed a de novo heterozygous mutation, the c. 29C>T (p. T10I).
Assuntos
Fraturas do Fêmur/diagnóstico , Progéria/complicações , Adolescente , Fraturas do Fêmur/complicações , Fraturas do Fêmur/diagnóstico por imagem , Humanos , Masculino , Progéria/diagnóstico , Recidiva , SíndromeRESUMO
The ageing process is a progressive decrease in physiological function, caused by accruement of damage and misregulation in the cells and tissues of an organism. Human ageing has been the focus of much scientific investigation, but studies have been complicated by the variability of the process between subjects and the slow pace at which it occurs. Although the consequences of ageing on cellular biochemical signalling and metabolism have been well studied, the impact on the mechanical properties of cells and the extracellular matrix - and the mechanotransduction pathways that connect the two - have often been overlooked. In this review we will discuss recent advances in the fields of nuclear and cytoskeletal biophysics, and consider this work in the context of ageing. In particular, we will examine the role of the nucleus in cellular mechanotransduction and in 'age-related diseases/phenomena' such as progeria and cellular senescence. Finally, we will discuss the therapeutic options being explored, drawing attention to a new field of medicine termed 'mechano-medicine' that may prove useful in addressing age-related pathology.
Assuntos
Envelhecimento/metabolismo , Senescência Celular , Mecanotransdução Celular , Progéria/metabolismo , Envelhecimento/genética , Animais , Núcleo Celular/metabolismo , Humanos , Progéria/genética , Progéria/patologiaRESUMO
We herein report a case of a 28-year-old man with generalized lipodystrophy-associated progeroid syndrome treated by leptin replacement. He showed symptoms of generalized lipodystrophy around onset of puberty. His body mass index was 11.9 kg/m2, and he had a short stature, birdlike facies, dental crowding due to micrognathia, partial graying and loss of hair, and a high-pitched voice, all of which are typical features of the progeroid syndrome. Laboratory examinations and abdominal ultrasonography revealed diabetes mellitus, insulin-resistance, dyslipidemia, decreased serum leptin levels (2.2 ng/mL), elevated serum hepatobiliary enzyme levels and fatty liver. Whole exome sequencing revealed de novo heterozygous LMNA p.T10I mutation, indicating generalized lipodystrophy-associated progeroid syndrome, which is a newly identified subtype of atypical progeroid syndrome characterized by severe metabolic abnormalities. Daily injection of metreleptin [1.2 mg (0.04 mg/kg)/day] was started. Metreleptin treatment significantly improved his diabetes from HbA1c 11.0% to 5.4% in six months. It also elevated serum testosterone levels. Elevated serum testosterone levels persisted even 1 year after the initiation of metreleptin treatment. To the best of our knowledge, this is the first Japanese case report of generalized lipodystrophy-associated progeroid syndrome. Furthermore, we evaluated short and long-term effectiveness of leptin replacement on generalized lipodystrophy by monitoring metabolic and endocrine profiles.
Assuntos
Diabetes Mellitus/metabolismo , Dislipidemias/metabolismo , Fígado Gorduroso/metabolismo , Hipogonadismo/metabolismo , Leptina/análogos & derivados , Lipodistrofia Generalizada Congênita/tratamento farmacológico , Progéria/tratamento farmacológico , Adulto , Alanina Transaminase/metabolismo , Aspartato Aminotransferases/metabolismo , Glicemia/metabolismo , Diabetes Mellitus/etiologia , Dislipidemias/etiologia , Fígado Gorduroso/diagnóstico por imagem , Fígado Gorduroso/etiologia , Hemoglobinas Glicadas/metabolismo , Humanos , Hipogonadismo/etiologia , Lamina Tipo A/genética , Leptina/uso terapêutico , Lipase/metabolismo , Lipodistrofia Generalizada Congênita/complicações , Lipodistrofia Generalizada Congênita/genética , Lipodistrofia Generalizada Congênita/metabolismo , Masculino , Progéria/complicações , Progéria/genética , Progéria/metabolismo , Resultado do TratamentoRESUMO
Progeroid syndromes are rare genetic disorders that phenotypically resemble natural aging. Different causal mutations have been identified, but no molecular alterations have been identified that are in common to these diseases. DNA replication timing (RT) is a robust cell type-specific epigenetic feature highly conserved in the same cell types from different individuals but altered in disease. Here, we characterized DNA RT program alterations in Hutchinson-Gilford progeria syndrome (HGPS) and Rothmund-Thomson syndrome (RTS) patients compared with natural aging and cellular senescence. Our results identified a progeroid-specific RT signature that is common to cells from three HGPS and three RTS patients and distinguishes them from healthy individuals across a wide range of ages. Among the RT abnormalities, we identified the tumor protein p63 gene (TP63) as a gene marker for progeroid syndromes. By using the redifferentiation of four patient-derived induced pluripotent stem cells as a model for the onset of progeroid syndromes, we tracked the progression of RT abnormalities during development, revealing altered RT of the TP63 gene as an early event in disease progression of both HGPS and RTS. Moreover, the RT abnormalities in progeroid patients were associated with altered isoform expression of TP63 Our findings demonstrate the value of RT studies to identify biomarkers not detected by other methods, reveal abnormal TP63 RT as an early event in progeroid disease progression, and suggest TP63 gene regulation as a potential therapeutic target.
Assuntos
Período de Replicação do DNA , Progéria/genética , Idoso de 80 Anos ou mais , Biomarcadores , Criança , Fibroblastos/metabolismo , Expressão Gênica , Genômica/métodos , Humanos , Recém-Nascido , Lamina Tipo A/genética , Lamina Tipo A/metabolismo , Progéria/metabolismo , Fatores de Transcrição/genética , Proteínas Supressoras de Tumor/genéticaRESUMO
BACKGROUND: Gorlin-Chaudhry-Moss syndrome (GCMS) and Fontaine-Farriaux syndrome (FFS) are extremely rare genetic disorders that share similar clinical manifestations. Because a de novo missense mutation of the solute carrier family 25 member 24 (SLC25A24) gene was suggested to be the common genetic basis of both syndromes, it has been proposed recently that they be integrated into a single disorder under the name of Fontaine progeroid syndrome (FPS). CASE PRESENTATION: A 9-year-old Korean girl presented with typical clinical features of FPS. She had generalized loose skin with decreased subcutaneous fat, skin wrinkling on the forehead and limbs, skull deformities and a peculiar facial appearance with microphthalmia and midface hypoplasia, anomalies of the digits and nails, a large umbilical hernia and a nearly normal developmental outcome. She exhibited prenatal and postnatal growth retardation together with short stature, and records showed that her height and weight were invariably under - 2.0 SD from birth to the age of 10 years. SLC25A24 analysis revealed a heterozygous mutation reported previously, NM_013386:c.650G > A, p.[Arg217His]. After screening her family for the identified mutation, she was confirmed as being a de novo case of FPS caused by an SLC25A24 mutation. CONCLUSION: We describe a Korean girl with typical clinical findings of FPS and a de novo mutation in SLC25A24, as well as 10 years of clinical follow-up, including growth and developmental achievements.