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1.
J Cardiovasc Dev Dis ; 11(3)2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38535109

RESUMO

Mutations in the LMNA-gene can cause a variety of 'laminopathies'. These laminopathies are associated with a range of phenotypes, including disorders affecting the adipose tissue, peripheral nerves, the heart, such as dilated cardiomyopathy and conduction system abnormalities, and less commonly, progeroid disorders. This case series describes two families in which two novel LMNA-gene variants were identified, and who presented with an atypical progeroid phenotype with primarily premature aortic and mitral valve stenosis. Interestingly, these families exhibited no clear evidence of multisystem involvement, illustrating the complex role of lamins A/C.

2.
Cell Tissue Res ; 394(1): 189-207, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37572165

RESUMO

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 Celular
3.
Front Cardiovasc Med ; 10: 1109008, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37465451

RESUMO

Objective: To characterize the cardiac phenotype associated with the novel pathogenic variant (c.1526del) of LMNA gene, which we identified in a large, six-generation family. Methods and Results: A family tree was constructed. The clinical data of living and deceased family members were collected. DNA samples from 7 family members were analyzed for LMNA mutations using whole-exome high-throughput sequencing technology. The clinical presentation of pathogenic variant carriers was evaluated. In this six-generation family (n = 67), one member experienced sudden death at the age of 40-years-old. Three pathogenic variant carriers were identified to possess a novel heterozygous deletion mutation in LMNA gene (HGVS: NM_170707.4, c.1526del) located at exon 9 of LMNA chr1:156137145, which creates a premature translational stop signal (p.Pro509Leufs*39) in the LMNA gene and results in an mutant lamin A protein product. The main symptoms of the pathogenic variant carriers were palpitation, fatigue, and syncope, which typically occurred around 20-years-old. AV-conduction block and non-sustained ventricular tachycardia were the first signs of disease and would rapidly progress to atrial standstill around 30-years-old. Significant right atrial enlargement and bicuspid aortic valve malformation was also commonly seen in patients who carried this pathogenic variant. Conclusion: The pathogenic variant of c.1526del p.P509Lfs*39 was a frameshift deletion located at exon 9 of LMNA chr1:156137145 and causes severe right atrial enlargement, sick sinus syndrome, atrial standstill, ventricular tachycardia, and bicuspid aortic valve malformation. Our findings expand the phenotypic spectrum of novel LMNA gene mutations.

4.
Cureus ; 15(4): e37824, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37213971

RESUMO

Laminopathy is muscular dystrophy caused by an LMNA gene mutation. It is characterized by cardiac disease such as atrial fibrillation. We report a case of laminopathy in a 49-year-old woman who presented with cardiogenic stroke. She had experienced weakness in her limb-girdle muscles since childhood, atrial fibrillation, cardiomyopathy, and mild contracture of the ankle joints, and had a familial history of heart disease. Gene analysis identified a novel heterozygous variant, c. 1135C>A (p.Leu379Ile), in the LMNA gene. Laminopathy can be an underlying disease in ischemic stroke, especially in young to middle age.

5.
Artigo em Inglês | MEDLINE | ID: mdl-37231758

RESUMO

BACKGROUND: Whole exome sequencing (WES) provides support for clinical diagnosis and treatment of genetically related diseases based on specific probe capture and high-throughput second-generation sequencing technology. Familial partial lipodystrophy 2 (FPLD2; OMIM # 151660) or type 2 Köbberling-Dunnigan syndrome with insulin resistance syndrome is uncommon in mainland China and elsewhere. AIMS: We report the case in order to have a further understanding of FPLD2 or type 2 KobberlingDunnigan syndrome) with the assistance of WES and improve the clinical and genetic understanding and diagnosis of this disease. CASE: A 30-year-old woman was admitted to the cadre department of our hospital at 14:00 on July 11, 2021, because of hyperglycemia, a rapid heart rate, and excessive sweating during pregnancy. An oral glucose tolerance test (OGTT) showed that insulin and C-peptide increased slowly after glucose stimulation, and the peak value was extended backward (Table 1). It was suggested that the patient had developed insulin antibodies, resulting in insulin resistance. Her clinical features and familial inheritance were consistent with FPLD2 (type 2 Kobberling-Dunnigan syndrome). The results of WES indicated that a heterozygous mutation occurred in exon 8 of the LMNA gene, because the base C at position 1444 was mutated into T during transcription. This mutation changed the amino acid position 482 of the encoded protein from Arg to Trp. Type 2 KobberlingDunnigan syndrome is associated with an LMNA gene mutation. According to the patient's clinical manifestations, hypoglycemic and lipid-lowering therapy is recommended. CONCLUSION: WES can assist in the simultaneous clinical investigation or confirmation of FPLD2 and help identify diseases with similar clinical phenotypes. This case demonstrates that familial partial lipodystrophy is associated with an LMNA gene mutation on chromosome 1q21-22. This is one of the few cases of familial partial lipodystrophy diagnosed by WES.

6.
Yi Chuan ; 44(10): 913-925, 2022 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-36384727

RESUMO

Lipodystrophy syndrome caused by LMNA gene mutation is a group of autosomal dominant monogenic diseases, characterized by selective fat loss and metabolic abnormalities with insulin resistance. In this review, we summarize the clinical manifestations caused by multiple pathogenic LMNA mutations reported so far, including metabolic complications, cardiovascular abnormalities, gonadal axis disorders, myopathy, and renal abnormalities. Meanwhile, we also clarify the possible pathogenic mechanism, diagnosis, and treatment, in order to improve the understanding of the disease and to provide a reference for basic research and clinical diagnosis and treatment of this disease.


Assuntos
Resistência à Insulina , Lipodistrofia , Humanos , Lipodistrofia/genética , Lipodistrofia/metabolismo , Mutação , Resistência à Insulina/genética , Lamina Tipo A/genética
7.
Artigo em Inglês | MEDLINE | ID: mdl-36816159

RESUMO

Genetic mutations can present with cardiomyopathies and ventricular arrhythmias in young population in the absence of other cardiac risk factors. LMNA genetic mutation is one of the causes of dilated cardiomyopathy (DCM) which can present with conduction abnormalities and arrhythmias. We present a case of LMNA genetic mutation in an African American male who presented with ventricular tachycardia in the absence of dilated cardiomyopathy initially mimicking cardiac sarcoidosis. Diagnostic challenges included initial impression of cardiac sarcoidosis as suggested by cardiac MRI, but negative tissue pathology on endomyocardial biopsy and negative activity on FDG PET scan. Treatment involved initiation of beta blocker and an implantable cardiac defibrillator placement for secondary prevention.

8.
Front Cell Dev Biol ; 9: 761469, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34722546

RESUMO

A-type lamins are the main structural components of the nucleus, which are mainly localized at the nucleus periphery. First of all, A-type lamins, together with B-type lamins and proteins of the inner nuclear membrane, form a stiff structure-the nuclear lamina. Besides maintaining the nucleus cell shape, A-type lamins play a critical role in many cellular events, such as gene transcription and epigenetic regulation. Nowadays it is clear that lamins play a very important role in determining cell fate decisions. Various mutations in genes encoding A-type lamins lead to damages of different types of tissues in humans, collectively known as laminopathies, and it is clear that A-type lamins are involved in the regulation of cell differentiation and stemness. However, the mechanisms of this regulation remain unclear. In this review, we discuss how A-type lamins can execute their regulatory role in determining the differentiation status of a cell. We have summarized recent data focused on lamin A/C action mechanisms in regulation of cell differentiation and identity development of stem cells of different origin. We also discuss how this knowledge can promote further research toward a deeper understanding of the role of lamin A/C mutations in laminopathies.

9.
Recent Pat Biotechnol ; 15(4): 266-285, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34602042

RESUMO

BACKGROUND: Hutchinson-Gilford progeria syndrome (HGPS), also known as progeria of childhood or progeria is a rare, rapid, autosomal dominant genetic disorder characterized by premature aging which occurs shortly after birth. HGPS occurs as a result of de novo point mutation in the gene recognized as LMNA gene that encodes two proteins, Lamin A protein and Lamin C protein which are the structural components of the nuclear envelope. Mutations in the gene trigger abnormal splicing and induce internal deletion of 50 amino acids leading to the development of a truncated form of Lamin A protein known as Progerin. Progerin generation can be considered the crucial step in HGPS since the protein is highly toxic to human cells, permanently farnesylated, and exhibits variation in several biochemical and structural properties within the individual. HGPS also produces complications such as skin alterations, growth failure, atherosclerosis, hair and fat loss, and bone and joint diseases. We have also revised all relevant patents relating to Hutchinson-Gilford progeria syndrome and its therapy in the current article. METHODS: The goal of the present review article is to provide information about Hutchinson- Gilford progeria syndrome (HGPS) and the use of CRISPR/Cas technology as a promising treatment approach in the treatment of the disease. The review also discusses about different pharmacological and non-pharmacological methods of treatment currently used for HGPS. RESULTS: The main limitation associated with progeria is the lack of a definitive cure. The existing treatment modality provides only symptomatic relief. Therefore, it is high time to develop a therapeutic method that hastens premature aging in such patients. CONCLUSION: CRISPR/Cas technology is a novel gene-editing tool that allows genome editing at specific loci and is found to be a promising therapeutic approach for the treatment of genetic disorders such as HGPS where dominant-negative mutations take place.


Assuntos
Progéria , Sistemas CRISPR-Cas , Terapia Genética , Humanos , Patentes como Assunto , Progéria/genética , Tecnologia
11.
Eur J Paediatr Neurol ; 32: 115-121, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33940562

RESUMO

LMNA-related congenital muscular dystrophy (L-CMD) is the most severe phenotypic form of skeletal muscle laminopathies. This paper reports clinical presentation of the disease in 15 Polish patients from 13 families with genetically confirmed skeletal muscle laminopathy. In all these patients floppy infant syndrome was the first manifestation of the disease. The genetic diagnosis was established by next generation sequencing (targeted panel or exome; 11 patients) or classic Sanger sequencing (4 patients). In addition to known pathogenic LMNA variants: c.116A > G (p.Asn39Ser), c.745C > T (p.Arg249Trp), c.746G > A (p.Arg249Gln), c.1072G > A (p.Glu358Lys), c.1147G > A (p.Glu383Lys), c.1163G > C (p.Arg388Pro), c.1357C > T (p.Arg453Trp), c.1583C > G (p.Thr528Arg), we have identified three novel ones: c.121C > G (p.Arg41Gly), c.1127A > G (p.Tyr376Cys) and c.1160T > C (p.Leu387Pro). Eleven patients had de novo mutations, 4 - familial. In one family we observed intrafamilial variability of clinical course: severe L-CMD in the male proband, intermediate form in his sister and asymptomatic in their mother. One asymptomatic father had somatic mosaicism. L-CMD should be suspected in children with hypotonia in infancy and delayed motor development, who have poor head control, severe hyperlordosis and unstable and awkward gait. Serum creatine kinase may be high (~1000IU/l). Progression of muscle weakness is fast, leading to early immobilization. In some patients with L-CMD joint contractures can develop with time. MRI shows that the most frequently affected muscles are the serratus anterior, lumbar paraspinal, gluteus, vastus, adductor magnus, hamstrings, medial head of gastrocnemius and soleus. Ultra-rare laminopathies can be a relatively common cause of generalized hypotonia in children. Introduction of wide genome sequencing methods was a breakthrough in diagnostics of diseases with great clinical and genetic variability and allowed approach "from genotype do phenotype". However target sequencing of LMNA gene could be considered in selected patients with clinical picture suggestive for laminopathy.


Assuntos
Lamina Tipo A/genética , Hipotonia Muscular/genética , Distrofias Musculares/complicações , Distrofias Musculares/genética , Adolescente , Criança , Pré-Escolar , Feminino , Genótipo , Humanos , Imageamento por Ressonância Magnética , Masculino , Mutação , Linhagem , Fenótipo
12.
Front Endocrinol (Lausanne) ; 12: 675096, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33953703

RESUMO

Purpose: Familial partial lipodystrophy type 2 (FPLD2) patients generally develop a wide variety of severe metabolic complications. However, they are not usually affected by primary cardiomyopathy and conduction system disturbances, although a few cases of FPLD2 and cardiomyopathy have been reported in the literature. These were all due to amino-terminal heterozygous lamin A/C mutations, which are considered as new forms of overlapping syndromes. Methods and Results: Here we report the identification of a female patient with FPLD2 due to a heterozygous missense variant c.604G>A in the exon 3 of the LMNA gene, leading to amino acid substitution (p.Glu202Lys) in the central alpha-helical rod domain of lamin A/C with a high propensity to form coiled-coil dimers. The patient's cardiac evaluations that followed the genetic diagnosis revealed cardiac rhythm disturbances which were promptly treated pharmacologically. Conclusions: This report supports the idea that there are "atypical forms" of FPLD2 with cardiomyopathy, especially when a pathogenic variant affects the lamin A/C head or alpha-helical rod domain. It also highlights how increased understanding of the genotype-phenotype correlation could help clinicians to schedule personalized monitoring of the lipodystrophic patient, in order to prevent uncommon but possible devastating manifestations, including arrhythmias and sudden death.


Assuntos
Estudos de Associação Genética , Lamina Tipo A/genética , Laminas/genética , Lipodistrofia Parcial Familiar/patologia , Mutação de Sentido Incorreto , Adulto , Feminino , Humanos , Lipodistrofia Parcial Familiar/genética , Prognóstico
13.
J Neuromuscul Dis ; 8(3): 419-439, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33682723

RESUMO

BACKGROUND: Variants in the LMNA gene, encoding lamins A/C, are responsible for a growing number of diseases, all of which complying with the definition of rare diseases. LMNA-related disorders have a varied phenotypic expression with more than 15 syndromes described, belonging to five phenotypic groups: Muscular Dystrophies, Neuropathies, Cardiomyopathies, Lipodystrophies and Progeroid Syndromes. Overlapping phenotypes are also reported. Linking gene and variants with phenotypic expression, disease mechanisms, and corresponding treatments is particularly challenging in laminopathies. Treatment recommendations are limited, and very few are variant-based. OBJECTIVE: The Treatabolome initiative aims to provide a shareable dataset of existing variant-specific treatment for rare diseases within the Solve-RD EU project. As part of this project, we gathered evidence of specific treatments for laminopathies via a systematic literature review adopting the FAIR (Findable, Accessible, Interoperable, and Reusable) guidelines for scientific data production. METHODS: Treatments for LMNA-related conditions were systematically collected from MEDLINE and Embase bibliographic databases and clinical trial registries (Cochrane Central Registry of Controlled Trials, clinicaltrial.gov and EudraCT). Two investigators extracted and analyzed the literature data independently. The included papers were assessed using the Oxford Centre for Evidence-Based Medicine 2011 Levels of Evidence. RESULTS: From the 4783 selected articles by a systematic approach, we identified 78 papers for our final analysis that corresponded to the profile of data defined in the inclusion and exclusion criteria. These papers include 2 guidelines/consensus papers, 4 meta-analyses, 14 single-arm trials, 15 case series, 13 cohort studies, 21 case reports, 8 expert reviews and 1 expert opinion. The treatments were summarized electronically according to significant phenome-genome associations. The specificity of treatments according to the different laminopathic phenotypical presentations is variable. CONCLUSIONS: We have extracted Treatabolome-worthy treatment recommendations for patients with different forms of laminopathies based on significant phenome-genome parings. This dataset will be available on the Treatabolome website and, through interoperability, on genetic diagnosis and treatment support tools like the RD-Connect's Genome Phenome Analysis Platform.


Assuntos
Laminopatias/tratamento farmacológico , Cardiomiopatias/tratamento farmacológico , Humanos , Lamina Tipo A , Lipodistrofia/tratamento farmacológico , Distrofias Musculares/tratamento farmacológico , Fenótipo , Doenças Raras
14.
Neurol India ; 69(6): 1835-1837, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34979702

RESUMO

BACKGROUND: Laminopathies are a group of diseases caused by mutations in the LMNA gene. Congenital dystrophy of the LMN is a rare disease, with less than 100 cases described in the literature. OBJECTIVES AND MATERIALS AND METHODS: We present the clinical case of a patient with congenital muscular dystrophy associated with an undescribed mutation in the LMNA gene. RESULTS: The patient presented progressive motor delay from 10 months with a physical examination consisting of global hypotonia, bilateral winged scapula, areflexia, hip and knee flexion posture, and positive Gowers. The patient developed progressive weakness with neck tone loss, functional impairment, and loss of gait at 5 years. CONCLUSIONS: To date, more than 20 mutations associated with congenital LMNA muscular dystrophy have been identified, most due to a single amino acid change (aa), few due to the gain or loss of several aa as in our patient.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala , Distrofias Musculares , Humanos , Lamina Tipo A/genética , Distrofias Musculares/diagnóstico , Distrofias Musculares/genética , Mutação/genética , Fenótipo
15.
Echocardiography ; 37(11): 1864-1868, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33070394

RESUMO

A 35-year-old man with history of recurrent arrhythmias presented for pulmonary vein isolation. He underwent pre-procedural screening for thromboembolism risk with transesophageal echocardiogram. He had an incidental finding of a rare fenestrated membrane overlying his left atrial appendage. Additional workup throughout his clinical course revealed genetic mutations in the LMNA and SNTA1 genes. There have been no previous reported genetic mutations reported in cases with LAA membranes.


Assuntos
Apêndice Atrial , Fibrilação Atrial , Veias Pulmonares , Tromboembolia , Adulto , Apêndice Atrial/diagnóstico por imagem , Fibrilação Atrial/complicações , Ecocardiografia Transesofagiana , Humanos , Masculino , Tromboembolia/diagnóstico por imagem
16.
BMC Med Genet ; 21(1): 152, 2020 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-32698886

RESUMO

BACKGROUND: Intermediate filament proteins that construct the nuclear lamina of a cell include the Lamin A/C proteins encoded by the LMNA gene, and are implicated in fundamental processes such as nuclear structure, gene expression, and signal transduction. LMNA mutations predominantly affect mesoderm-derived cell lineages in diseases collectively termed as laminopathies that include dilated cardiomyopathy with conduction defects, different forms of muscular dystrophies, and premature aging syndromes as Hutchinson-Gilford Progeria Syndrome. At present, our understanding of the molecular mechanisms regulating tissue-specific manifestations of laminopathies are still limited. METHODS: To gain deeper insight into the molecular mechanism of a novel LMNA splice-site mutation (c.357-2A > G) in an affected family with cardiac disease, we conducted deep RNA sequencing and pathway analysis for nine fibroblast samples obtained from three patients with cardiomyopathy, three unaffected family members, and three unrelated, unaffected individuals. We validated our findings by quantitative PCR and protein studies. RESULTS: We identified eight significantly differentially expressed genes between the mutant and non-mutant fibroblasts, that included downregulated insulin growth factor binding factor protein 5 (IGFBP5) in patient samples. Pathway analysis showed involvement of the ERK/MAPK signaling pathway consistent with previous studies. We found no significant differences in gene expression for Lamin A/C and B-type lamins between the groups. In mutant fibroblasts, RNA-seq confirmed that only the LMNA wild type allele predominately was expressed, and Western Blot showed normal Lamin A/C protein levels. CONCLUSIONS: IGFBP5 may contribute in maintaining signaling pathway homeostasis, which may lead to the absence of notable molecular and structural abnormalities in unaffected tissues such as fibroblasts. Compensatory mechanisms from other nuclear membrane proteins were not found. Our results also demonstrate that only one copy of the wild type allele is sufficient for normal levels of Lamin A/C protein to maintain physiological function in an unaffected cell type. This suggests that affected cell types such as cardiac tissues may be more sensitive to haploinsufficiency of Lamin A/C. These results provide insight into the molecular mechanism of disease with a possible explanation for the tissue specificity of LMNA-related dilated cardiomyopathy.


Assuntos
Cardiomiopatias/genética , Fibroblastos/metabolismo , Fibroblastos/patologia , Perfilação da Expressão Gênica , Lamina Tipo A/genética , Transdução de Sinais/genética , Sequência de Bases , Família , Regulação da Expressão Gênica , Humanos , Sistema de Sinalização das MAP Quinases/genética , Lâmina Nuclear/metabolismo
17.
Front Physiol ; 11: 761, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32719615

RESUMO

Mutations of Lamin A/C gene (LMNA) cause laminopathies, a group of disorders associated with a wide spectrum of clinically distinct phenotypes, affecting different tissues and organs. Heart involvement is frequent and leads to cardiolaminopathy LMNA-dependent cardiomyopathy (LMNA-CMP), a form of dilated cardiomyopathy (DCM) typically associated with conduction disorders and arrhythmias, that can manifest either as an isolated event or as part of a multisystem phenotype. Despite the recent clinical and molecular developments in the field, there is still lack of knowledge linking specific LMNA gene mutations to the distinct clinical manifestations. Indeed, the severity and progression of the disease have marked interindividual variability, even amongst members of the same family. Studies conducted so far have described Lamin A/C proteins involved in diverse biological processes, that span from a structural role in the nucleus to the regulation of response to mechanical stress and gene expression, proposing various mechanistic hypotheses. However, none of those is per se able to fully justify functional and clinical phenotypes of LMNA-CMP; therefore, the role of Lamin A/C in cardiac pathophysiology still represents an open question. In this review we provide an update on the state-of-the-art studies on cardiolaminopathy, in the attempt to draw a line connecting molecular mechanisms to clinical manifestations. While investigators in this field still wonder about a clear genotype/phenotype correlation in LMNA-CMP, our intent here is to recapitulate common mechanistic hypotheses that link different mutations to similar clinical presentations.

18.
Cells ; 9(3)2020 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-32235738

RESUMO

A type lamins are fundamental components of the nuclear lamina. Changes in lamin A expression correlate with malignant transformation in several cancers. However, the role of lamin A has not been explored in osteosarcoma (OS). Here, we wanted to investigate the role of lamin A in normal osteoblasts (OBs) and OS cells. Thus, we studied the expression of lamin A/C in OS cells compared to OBs and evaluated the effects of lamin A overexpression in OS cell lines. We show that, while lamin A expression increases during osteoblast differentiation, all examined OS cell lines express lower lamin A levels relative to differentiated OBs. The condition of low LMNA expression confers to OS cells a significant increase in migration potential, while overexpression of lamin A reduces migration ability of OS cells. Moreover, overexpression of unprocessable prelamin A also reduces cell migration. In agreement with the latter finding, OS cells which accumulate the highest prelamin A levels upon inhibition of lamin A maturation by statins, had significantly reduced migration ability. Importantly, OS cells subjected to statin treatment underwent apoptotic cell death in a RAS-independent, lamin A-dependent manner. Our results show that pro-apoptotic effects of statins and statin inhibitory effect on OS cell migration are comparable to those obtained by prelamin A accumulation and further suggest that modulation of lamin A expression and post-translational processing can be a tool to decrease migration potential in OS cells.


Assuntos
Movimento Celular , Lamina Tipo A/metabolismo , Osteossarcoma/metabolismo , Osteossarcoma/patologia , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Humanos , Lovastatina/farmacologia , Osteoblastos/efeitos dos fármacos , Osteoblastos/metabolismo , Osteoblastos/patologia
19.
Endocr J ; 67(2): 211-218, 2020 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-31708526

RESUMO

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 Tratamento
20.
Endocr J ; 66(11): 961-969, 2019 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-31270292

RESUMO

Werner syndrome (WS) is a rare, adult-onset progeroid syndrome. Classic WS is caused by WRN mutation and partial atypical WS (AWS) is caused by LMNA mutation. A 19-year-old female patient with irregular menstruation and hyperglycemia was admitted. Physical examination revealed characteristic faces of progeria, graying and thinning of the hair scalp, thinner and atrophic skin over the hands and feet, as well as lipoatrophy of the extremities, undeveloped breasts at Tanner stage 3, and short stature. The patient also suffered from severe insulin-resistant diabetes mellitus, hyperlipidemia, fatty liver, and polycystic ovarian morphology. Possible WS was considered and both WRN and LMNA genes were analyzed. A novel missense mutation p.L140Q (c.419T>A) in the LMNA gene was identified and confirmed the diagnosis of AWS. Her father was a carrier of the same mutation. We carried out therapy for lowering blood glucose and lipid and improving insulin resistance, et al. The fasting glucose, postprandial glucose and triglyceride level was improved after treatment for 9 days. Literature review of AWS was performed to identify characteristics of the disease. Diabetes mellitus is one of the clinical manifestations of WS and attention must give to the differential diagnosis. Gene analysis is critical in the diagnosis of WS. According to the literature, classic and atypical WS differ in incidence, pathogenic gene, and clinical manifestations. Characteristic dermatological pathology may be significantly more important for the initial identification of AWS. Early detection, appropriate treatments, and regular follow-up may improve prognosis and survival of WS patients.


Assuntos
Diabetes Mellitus/metabolismo , Hipogonadismo/fisiopatologia , Síndrome de Werner/fisiopatologia , Diabetes Mellitus/etiologia , Diabetes Mellitus/genética , Feminino , Humanos , Hipogonadismo/etiologia , Hipogonadismo/genética , Hipogonadismo/metabolismo , Lamina Tipo A/genética , Síndrome de Werner/complicações , Síndrome de Werner/genética , Adulto Jovem
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