RESUMEN

Genetic factors play a significant role in the pathogenesis of mitral valve diseases, including mitral valve prolapse (MVP) and mitral valve regurgitation. Genes like Fibrillin-1 (FBN1), Filamin A (FLNA), matrix metalloproteinase 2 (MMP2), and SRY-box transcription factor 9 (SOX9) are known to influence mitral valve pathology but knowledge of the exact mechanism is far from clear. Data regarding serum parameters, transesophageal echocardiography, and genetic and histopathologic parameters were investigated in 54 patients who underwent cardiovascular surgery for mitral valve regurgitation. The possible association between Fibrillin-1, Filamin A, MMP2, and SOX9 gene expressions was checked in relationship with the parameters of systemic inflammatory response. The mRNA expression levels (RQ-relative quantification) were categorized into three distinct groups: low (RQ < 1), medium/normal (RQ = 1-2), and high (RQ > 2). Severe fibrosis of the mitral valve was reflected by high expression of FBN1 and low expression of MMP2 (p < 0.05). The myxoid degeneration level was associated with the mRNA expression level for FBN1 and a low lymphocyte-monocyte ratio was associated with an increased mRNA expression of FBN1 (p < 0.05). A high number of monocytes was associated with high values of FBN1 whereas the increase in the number of lymphocytes was associated with high levels of MMP2. In addition, we observed that the risk of severe hyalinization was enhanced by a low mRNA expression of FLNA and/or SOX9. In conclusion, a lower FLNA mRNA expression can reflect the aging process that is highlighted in mitral valve pathology as a higher risk for hyalinization, especially in males, that might be prevented by upregulation of the SOX9 gene. FBN1 and MMP2 influence the inflammation-related fibrotic degeneration of the mitral valve. Understanding the genetic base of mitral valve pathology can provide insights into disease mechanisms, risk stratification, and potential therapeutic targets.

Asunto(s)

Fibrilina-1 , Filaminas , Metaloproteinasa 2 de la Matriz , Válvula Mitral , Factor de Transcripción SOX9 , Humanos , Fibrilina-1/genética , Fibrilina-1/metabolismo , Factor de Transcripción SOX9/metabolismo , Factor de Transcripción SOX9/genética , Filaminas/metabolismo , Filaminas/genética , Masculino , Femenino , Metaloproteinasa 2 de la Matriz/metabolismo , Metaloproteinasa 2 de la Matriz/genética , Persona de Mediana Edad , Válvula Mitral/patología , Válvula Mitral/metabolismo , Anciano , Prolapso de la Válvula Mitral/genética , Prolapso de la Válvula Mitral/metabolismo , Prolapso de la Válvula Mitral/patología , Insuficiencia de la Válvula Mitral/genética , Insuficiencia de la Válvula Mitral/metabolismo , Insuficiencia de la Válvula Mitral/patología , Adipoquinas

RESUMEN

The incidence of intrahepatic cholangiocarcinoma (ICC) is steadily rising, and it is associated with a high mortality rate. Clinical samples were collected to detect the expression of HSPB8 and BAG3 in ICC tissues. ICC cells were cultured and transfected with plasmids that overexpressed or silenced specific genes to investigate the impact of gene expression alterations on cell function. qPCR and Western blot techniques were utilized to measure gene and protein expression levels. A wound healing assay was conducted to assess cell migration ability. The Transwell assay was used to assess cell invasion ability. Co-IP was used to verify the binding relationship between HSPB8 and BAG3. The effects of HSPB8 and BAG3 on lung metastasis of tumors in vivo were verified by constructing a metastatic tumor model. Through the above experiments, we discovered that the expressions of HSPB8 and BAG3 were up-regulated in ICC tissues and cells, and their expressions were positively correlated. The metastatic ability of ICC cells could be promoted or inhibited by upregulating or downregulating the expression of BAG3. Furthermore, the HSPB8-BAG3 chaperone complex resulted in the abnormal degradation of Filamin A by activating autophagy. Increased expression of Filamin A inhibits the migration and invasion of ICC cells. Overexpression of HSPB8 and BAG3 in vivo promoted the lung metastasis ability of ICC cells. The HSPB8-BAG3 chaperone complex promotes ICC cell migration and invasion by regulating CASA-mediated degradation of Filamin A, offering insights for enhancing ICC therapeutic strategies.

Asunto(s)

Proteínas Adaptadoras Transductoras de Señales , Proteínas Reguladoras de la Apoptosis , Neoplasias de los Conductos Biliares , Colangiocarcinoma , Filaminas , Chaperonas Moleculares , Invasividad Neoplásica , Colangiocarcinoma/patología , Colangiocarcinoma/metabolismo , Colangiocarcinoma/genética , Humanos , Filaminas/metabolismo , Filaminas/genética , Chaperonas Moleculares/metabolismo , Chaperonas Moleculares/genética , Animales , Ratones , Proteínas Reguladoras de la Apoptosis/metabolismo , Proteínas Reguladoras de la Apoptosis/genética , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Neoplasias de los Conductos Biliares/patología , Neoplasias de los Conductos Biliares/metabolismo , Neoplasias de los Conductos Biliares/genética , Proteínas de Choque Térmico/metabolismo , Proteínas de Choque Térmico/genética , Movimiento Celular , Línea Celular Tumoral , Masculino , Femenino , Ratones Desnudos , Regulación Neoplásica de la Expresión Génica

RESUMEN

Coordinated cell shape changes are a major driver of tissue morphogenesis, with apical constriction of epithelial cells leading to tissue bending. We previously identified that interplay between the apical-medial actomyosin, which drives apical constriction, and the underlying longitudinal microtubule array has a key role during tube budding of salivary glands in the Drosophila embryo. At this microtubule-actomyosin interface, a hub of proteins accumulates, and we have shown before that this hub includes the microtubule-actin crosslinker Shot and the microtubule minus-end-binding protein Patronin. Here, we identify two actin-crosslinkers, ß-heavy (H)-Spectrin (also known as Karst) and Filamin (also known as Cheerio), and the multi-PDZ-domain protein Big bang as components of the protein hub. We show that tissue-specific degradation of ß-H-Spectrin leads to reduction of apical-medial F-actin, Shot, Patronin and Big bang, as well as concomitant defects in apical constriction, but that residual Patronin is still sufficient to assist microtubule reorganisation. We find that, unlike Patronin and Shot, neither ß-H-Spectrin nor Big bang require microtubules for their localisation. ß-H-Spectrin is instead recruited via binding to apical-medial phosphoinositides, and overexpression of the C-terminal pleckstrin homology domain-containing region of ß-H-Spectrin (ß-H-33) displaces endogenous ß-H-Spectrin and leads to strong morphogenetic defects. This protein hub therefore requires the synergy and coincidence of membrane- and microtubule-associated components for its assembly and function in sustaining apical constriction during tubulogenesis.

Asunto(s)

Actinas , Proteínas de Drosophila , Drosophila melanogaster , Microtúbulos , Morfogénesis , Espectrina , Animales , Proteínas de Drosophila/metabolismo , Proteínas de Drosophila/genética , Espectrina/metabolismo , Espectrina/genética , Microtúbulos/metabolismo , Actinas/metabolismo , Drosophila melanogaster/metabolismo , Proteínas de Microfilamentos/metabolismo , Proteínas de Microfilamentos/genética , Filaminas/metabolismo , Filaminas/genética , Glándulas Salivales/metabolismo , Glándulas Salivales/embriología , Glándulas Salivales/citología , Forma de la Célula , Polaridad Celular , Actomiosina/metabolismo , Proteínas Asociadas a Microtúbulos

RESUMEN

BACKGROUND: Thoracic aortic aneurysm (TAA) is associated with significant morbidity and mortality. Although individuals with family histories of TAA often undergo clinical molecular genetic testing, adults with nonsyndromic TAA are not typically evaluated for genetic causes. We sought to understand the genetic contribution of both germline and somatic mosaic variants in a cohort of adult individuals with nonsyndromic TAA at a single center. METHODS AND RESULTS: One hundred eighty-one consecutive patients <60 years who presented with nonsyndromic TAA at the Massachusetts General Hospital underwent deep (>500×) targeted sequencing across 114 candidate genes associated with TAA and its related functional pathways. Samples from 354 age- and sex-matched individuals without TAA were also sequenced, with a 2:1 matching. We found significant enrichments for germline (odds ratio [OR], 2.44, P=4.6×10-6 [95% CI, 1.67-3.58]) and also somatic mosaic variants (OR, 4.71, P=0.026 [95% CI, 1.20-18.43]) between individuals with and without TAA. Likely genetic causes were present in 24% with nonsyndromic TAA, of which 21% arose from germline variants and 3% from somatic mosaic alleles. The 3 most frequently mutated genes in our cohort were FLNA (encoding Filamin A), NOTCH3 (encoding Notch receptor 3), and FBN1 (encoding Fibrillin-1). There was increased frequency of both missense and loss of function variants in TAA individuals. CONCLUSIONS: Likely contributory dominant acting genetic variants were found in almost one quarter of nonsyndromic adults with TAA. Our findings suggest a more extensive genetic architecture to TAA than expected and that genetic testing may improve the care and clinical management of adults with nonsyndromic TAA.

Asunto(s)

Aneurisma de la Aorta Torácica , Predisposición Genética a la Enfermedad , Mutación de Línea Germinal , Mosaicismo , Humanos , Masculino , Femenino , Aneurisma de la Aorta Torácica/genética , Aneurisma de la Aorta Torácica/diagnóstico , Adulto , Persona de Mediana Edad , Receptor Notch3/genética , Fibrilina-1/genética , Estudios de Casos y Controles , Fenotipo , Filaminas/genética , Factores de Riesgo , Secuenciación de Nucleótidos de Alto Rendimiento , Adipoquinas

RESUMEN

Periventricular nodular heterotopia (PNH), the most common brain malformation diagnosed in adulthood, is characterized by the presence of neuronal nodules along the ventricular walls. PNH is mainly associated with mutations in the FLNA gene - encoding an actin-binding protein - and patients often develop epilepsy. However, the molecular mechanisms underlying the neuronal failure still remain elusive. It has been hypothesized that dysfunctional cortical circuitry, rather than ectopic neurons, may explain the clinical manifestations. To address this issue, we depleted FLNA from cortical pyramidal neurons of a conditional Flnaflox/flox mice by timed in utero electroporation of Cre recombinase. We found that FLNA regulates dendritogenesis and spinogenesis thus promoting an appropriate excitatory/inhibitory inputs balance. We demonstrated that FLNA modulates RAC1 and cofilin activity through its interaction with the Rho-GTPase Activating Protein 24 (ARHGAP24). Collectively, we disclose an uncharacterized role of FLNA and provide strong support for neural circuit dysfunction being a consequence of FLNA mutations.

Asunto(s)

Corteza Cerebral , Filaminas , Proteína de Unión al GTP rac1 , Animales , Ratones , Factores Despolimerizantes de la Actina/metabolismo , Corteza Cerebral/metabolismo , Filaminas/metabolismo , Filaminas/genética , Proteínas Activadoras de GTPasa/metabolismo , Proteínas Activadoras de GTPasa/genética , Ratones Transgénicos , Neurogénesis/fisiología , Neuronas/metabolismo , Neuropéptidos/metabolismo , Neuropéptidos/genética , Heterotopia Nodular Periventricular/genética , Heterotopia Nodular Periventricular/metabolismo , Heterotopia Nodular Periventricular/patología , Células Piramidales/metabolismo , Proteína de Unión al GTP rac1/metabolismo , Proteína de Unión al GTP rac1/genética

RESUMEN

Arrhythmogenic cardiomyopathy (ACM) is an inherited myocardial disease at risk of sudden death. Genetic testing impacts greatly in ACM diagnosis, but gene-disease associations have yet to be determined for the increasing number of genes included in clinical panels. Genetic variants evaluation was undertaken for the most relevant non-desmosomal disease genes. We retrospectively studied 320 unrelated Italian ACM patients, including 243 cases with predominant right-ventricular (ARVC) and 77 cases with predominant left-ventricular (ALVC) involvement, who did not carry pathogenic/likely pathogenic (P/LP) variants in desmosome-coding genes. The aim was to assess rare genetic variants in transmembrane protein 43 (TMEM43), desmin (DES), phospholamban (PLN), filamin c (FLNC), cadherin 2 (CDH2), and tight junction protein 1 (TJP1), based on current adjudication guidelines and reappraisal on reported literature data. Thirty-five rare genetic variants, including 23 (64%) P/LP, were identified in 39 patients (16/243 ARVC; 23/77 ALVC): 22 FLNC, 9 DES, 2 TMEM43, and 2 CDH2. No P/LP variants were found in PLN and TJP1 genes. Gene-based burden analysis, including P/LP variants reported in literature, showed significant enrichment for TMEM43 (3.79-fold), DES (10.31-fold), PLN (117.8-fold) and FLNC (107-fold). A non-desmosomal rare genetic variant is found in a minority of ARVC patients but in about one third of ALVC patients; as such, clinical decision-making should be driven by genes with robust evidence. More than two thirds of non-desmosomal P/LP variants occur in FLNC.

Asunto(s)

Displasia Ventricular Derecha Arritmogénica , Humanos , Displasia Ventricular Derecha Arritmogénica/genética , Femenino , Masculino , Adulto , Persona de Mediana Edad , Proteínas de la Membrana/genética , Cadherinas/genética , Desmosomas/genética , Desmosomas/metabolismo , Predisposición Genética a la Enfermedad , Variación Genética , Filaminas/genética , Estudios Retrospectivos , Italia , Proteínas de Unión al Calcio/genética , Antígenos CD/genética

RESUMEN

BACKGROUND: Clear cell renal cell carcinoma (ccRCC) remains a deadly disease with a poor prognosis. Here, we identified the ETS homologous factor (EHF) and its target Filamin-B (FLNB) as molecules related to immune evasion in ccRCC. We also explored the upstream modifier that manipulates EHF in ccRCC. DESIGN: Cell proliferation and apoptosis assay, wound healing assay, and Transwell assay were designed to analyze the effects of EHF or FLNB knockdown on the biological activity of ccRCC cells. The growth of differently treated ccRCC cells was assessed by orthotopic tumors. ccRCC cells with different treatments were co-cultured with macrophages, and the role of the lysine-specific demethylase 5B (KDM5B)/EHF/FLNB axis on macrophage polarization or ccRCC progression was characterized by detecting the expression of M2 macrophage markers in the co-culture system or tumor tissues of tumor-bearing mice. RESULTS: The expression of EHF and FLNB was higher, while KDM5B was lower in HK2 cells than in ccRCC cells. EHF overexpression inhibited the biological behavior of ccRCC cells and tumor growth in mice. EHF activated FLNB transcription. Knockdown of FLNB supported the biological activity of ccRCC cells and tumor growth and reversed M2 macrophage polarization in tumor tissues of mice in the presence of EHF. KDM5B inhibited EHF expression by H3K4me3 demethylation, and EHF knockdown potentiated M2 macrophage polarization and tumor growth in vivo repressed by KDM5B knockdown. CONCLUSIONS: KDM5B inhibited the expression of EHF by repressing H3K4me3 modification and the transcription of FLNB by EHF to promote immune evasion and progression of ccRCC.

Asunto(s)

Carcinoma de Células Renales , Proliferación Celular , Filaminas , Histona Demetilasas con Dominio de Jumonji , Neoplasias Renales , Factores de Transcripción , Animales , Humanos , Ratones , Apoptosis , Carcinoma de Células Renales/genética , Carcinoma de Células Renales/patología , Carcinoma de Células Renales/metabolismo , Línea Celular Tumoral , Filaminas/metabolismo , Filaminas/genética , Regulación Neoplásica de la Expresión Génica , Histona Demetilasas con Dominio de Jumonji/metabolismo , Histona Demetilasas con Dominio de Jumonji/genética , Neoplasias Renales/genética , Neoplasias Renales/patología , Neoplasias Renales/metabolismo , Macrófagos/metabolismo , Ratones Desnudos , Proteínas Nucleares , Proteínas Represoras , Factores de Transcripción/genética , Factores de Transcripción/metabolismo

RESUMEN

Filamins are mechanosensitive actin crosslinking proteins that organize the actin cytoskeleton in a variety of shapes and tissues. In muscles, filamin crosslinks actin filaments from opposing sarcomeres, the smallest contractile units of muscles. This happens at the Z-disc, the actin-organizing center of sarcomeres. In flies and vertebrates, filamin mutations lead to fragile muscles that appear ruptured, suggesting filamin helps counteract muscle rupturing during muscle contractions by providing elastic support and/or through signaling. An elastic region at the C-terminus of filamin is called the mechanosensitive region and has been proposed to sense and counteract contractile damage. Here we use molecularly defined mutants and microscopy analysis of the Drosophila indirect flight muscles to investigate the molecular details by which filamin provides cohesion to the Z-disc. We made novel filamin mutations affecting the C-terminal region to interrogate the mechanosensitive region and detected three Z-disc phenotypes: dissociation of actin filaments, Z-disc rupture, and Z-disc enlargement. We tested a constitutively closed filamin mutant, which prevents the elastic changes in the mechanosensitive region and results in ruptured Z-discs, and a constitutively open mutant which has the opposite elastic effect on the mechanosensitive region and gives rise to enlarged Z-discs. Finally, we show that muscle contraction is required for Z-disc rupture. We propose that filamin senses myofibril damage by elastic changes in its mechanosensory region, stabilizes the Z-disc, and counteracts contractile damage at the Z-disc.

Asunto(s)

Proteínas de Drosophila , Drosophila melanogaster , Filaminas , Contracción Muscular , Mutación , Miofibrillas , Animales , Citoesqueleto de Actina/metabolismo , Citoesqueleto de Actina/genética , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Filaminas/metabolismo , Filaminas/genética , Mecanotransducción Celular/genética , Contracción Muscular/genética , Contracción Muscular/fisiología , Miofibrillas/metabolismo , Miofibrillas/genética , Fenotipo , Sarcómeros/metabolismo , Sarcómeros/genética

RESUMEN

Disulfidptosis, a newly recognized cell death triggered by disulfide stress, has garnered attention for its potential role in osteoporosis (OP) pathogenesis. Although sulfide-related proteins are reported to regulate the balance of bone metabolism in OP, the precise involvement of disulfidptosis regulators remains elusive. Herein, leveraging the GSE56815 dataset, we conducted an analysis to delineate disulfidptosis-associated diagnostic clusters and immune landscapes in OP. Subsequently, vertebral bone tissues obtained from OP patients and controls were subjected to RNA sequencing (RNA-seq) for the validation of key disulfidptosis gene expression. Our analysis unveiled seven significant disulfidptosis regulators, including FLNA, ACTB, PRDX1, SLC7A11, NUBPL, OXSM, and RAC1, distinguishing OP samples from controls. Furthermore, employing a random forest model, we identified four diagnostic disulfidptosis regulators including FLNA, SLC7A11, NUBPL, and RAC1 potentially predictive of OP risk. A nomogram model integrating these four regulators was constructed and validated using the GSE35956 dataset, demonstrating promising utility in clinical decision-making, as affirmed by decision curve analysis. Subsequent consensus clustering analysis stratified OP samples into two different disulfidptosis subgroups (clusters A and B) using significant disulfidptosis regulators, with cluster B exhibiting higher disulfidptosis scores and implicating monocyte immunity, closely linked to osteoclastogenesis. Notably, RNA-seq analysis corroborated the expression patterns of two disulfidptosis modulators, PRDX1 and OXSM, consistent with bioinformatics predictions. Collectively, our study sheds light on disulfidptosis patterns, offering potential markers and immunotherapeutic avenues for future OP management.

Asunto(s)

Osteoporosis , Análisis de Secuencia de ARN , Proteína de Unión al GTP rac1 , Humanos , Osteoporosis/genética , Osteoporosis/inmunología , Proteína de Unión al GTP rac1/genética , Proteína de Unión al GTP rac1/metabolismo , Filaminas/genética , Femenino , Sistema de Transporte de Aminoácidos y+/genética , Sistema de Transporte de Aminoácidos y+/metabolismo , Nomogramas , Masculino , Peroxirredoxinas

RESUMEN

BACKGROUND: Many cardiomyopathy-associated FLNC pathogenic variants are heterozygous truncations, and FLNC pathogenic variants are associated with arrhythmias. Arrhythmia triggers in filaminopathy are incompletely understood. METHODS AND RESULTS: We describe an individual with biallelic FLNC pathogenic variants, p.Arg650X and c.970-4A>G, with peripartum cardiomyopathy and ventricular arrhythmias. We also describe clinical findings in probands with FLNC variants including Val2715fs87X, Glu2458Serfs71X, Phe106Leu, and c.970-4A>G with hypertrophic and dilated cardiomyopathy, atrial fibrillation, and ventricular tachycardia. Induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) were generated. The FLNC truncation, Arg650X/c.970-4A>G, showed a marked reduction in filamin C protein consistent with biallelic loss of function mutations. To assess loss of filamin C, gene editing of a healthy control iPSC line was used to generate a homozygous FLNC disruption in the actin binding domain. Because filamin C has been linked to protein quality control, we assessed the necessity of filamin C in iPSC-CMs for response to the proteasome inhibitor bortezomib. After exposure to low-dose bortezomib, FLNC-null iPSC-CMs showed an increase in the chaperone proteins BAG3, HSP70 (heat shock protein 70), and HSPB8 (small heat shock protein B8) and in the autophagy marker LC3I/II. FLNC null iPSC-CMs had prolonged electric field potential, which was further prolonged in the presence of low-dose bortezomib. FLNC null engineered heart tissues had impaired function after low-dose bortezomib. CONCLUSIONS: FLNC pathogenic variants associate with a predisposition to arrhythmias, which can be modeled in iPSC-CMs. Reduction of filamin C prolonged field potential, a surrogate for action potential, and with bortezomib-induced proteasome inhibition, reduced filamin C led to greater arrhythmia potential and impaired function.

Asunto(s)

Filaminas , Proteostasis , Filaminas/genética , Filaminas/metabolismo , Humanos , Femenino , Células Madre Pluripotentes Inducidas/metabolismo , Arritmias Cardíacas/genética , Arritmias Cardíacas/metabolismo , Arritmias Cardíacas/fisiopatología , Arritmias Cardíacas/etiología , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , Cardiomiopatías/genética , Cardiomiopatías/metabolismo , Cardiomiopatías/fisiopatología , Masculino , Adulto , Mutación , Bortezomib/farmacología

RESUMEN

OBJECTIVES: Genetic disorders involved in skeleton system arise due to the disturbance in skeletal development, growth and homeostasis. Filamin B is an actin binding protein which is large dimeric protein which cross link actin cytoskeleton filaments into dynamic structure. A single nucleotide changes in the FLNB gene causes spondylocarpotarsal synostosis syndrome, a rare bone disorder due to which the fusion of carpels and tarsals synostosis occurred along with fused vertebrae. In the current study we investigated a family residing in north-western areas of Pakistan. METHODS: The whole exome sequencing of proband was performed followed by Sanger sequencing of all family members of the subject to validate the variant segregation within the family. Bioinformatics tools were utilized to assess the pathogenicity of the variant. RESULTS: Whole Exome Sequencing revealed a novel variant (NM_001457: c.209C>T and p.Pro70Leu) in the FLNB gene which was homozygous missense mutation in the FLNB gene. The variant was further validated and visualized by Sanger sequencing and protein structure studies respectively as mentioned before. CONCLUSIONS: The findings have highlighted the importance of the molecular diagnosis in SCT (spondylocarpotarsal synostosis syndrome) for genetic risk counselling in consanguineous families.

Asunto(s)

Secuenciación del Exoma , Filaminas , Sinostosis , Humanos , Sinostosis/genética , Filaminas/genética , Masculino , Femenino , Linaje , Escoliosis/genética , Escoliosis/congénito , Anomalías Múltiples/genética , Mutación Missense , Pakistán , Homocigoto , Vértebras Lumbares/anomalías , Enfermedades Musculoesqueléticas , Vértebras Torácicas/anomalías

Asunto(s)

Filaminas , Miopatías Nemalínicas , Humanos , Masculino , Filaminas/genética , Filaminas/metabolismo , Músculo Esquelético/metabolismo , Músculo Esquelético/patología , Mutación , Miopatías Nemalínicas/genética , Miopatías Nemalínicas/patología , Anciano

RESUMEN

OBJECTIVE: To analyze the clinical phenotype and genetic basis of a Chinese pedigree affected with Otopalatodigital syndrome type 1 (OPD1). METHODS: A pedigree which was evaluated at the Department of Endocrinology, General Hospital of the Central Theater Command on December 3, 2020 was selected as the study subject. Clinical phenotype and genetic features of the proband were analyzed. Whole exome sequencing was employed to screen for genetic variants in the proband, and Sanger sequencing was used to verify the candidate variants in the proband's mother, uncle, maternal aunt, and paternal aunt. Pathogenicity analysis was also conducted for the candidate variants. RESULTS: The proband, a 16-year-old male, had shown distinctive facial features including mildly prominent eyebrows, down-slanting palpebral fissures, hypertelorism, and depressed nasal bridge. Additionally, he had clubbing of bilateral thumbs and big toes, and central type diabetes insipidus. Genetic sequencing revealed that he has harbored a heterozygous c.586C>T (p.R196W) missense variant of the FLNA gene (NM_001110556.2), which was also carried by his mother and uncle. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), this variant was classified as likely pathogenic (PM1+PM2_Supporting+PP2+PP3+PS4 Supporting). CONCLUSION: The heterozygous c.586C>T (p.R196W) variant of the FLNA gene probably underlay the pathogenesis in this OPD1 family. The central type diabetes insipidus in the proband may represent a newly discovered phenotype of OPD1. Above finding has contributed crucial information for the comprehensive understanding of the clinical manifestations and pathogenic mechanisms of OPD1.

Asunto(s)

Filaminas , Linaje , Fenotipo , Adolescente , Femenino , Humanos , Masculino , China , Pueblos del Este de Asia/genética , Secuenciación del Exoma , Filaminas/genética , Mutación Missense

RESUMEN

Filamin C (FLNC) is a highly important actin crosslinker and multi-adaptor protein in striated skeletal and cardiac muscle. Mutations have been linked to a range of cardiomyopathy types. Here, we generated induced pluripotent stem cells (iPSC) from a patient with dilated cardiomyopathy (DCM) harboring a new, unique heterozygous FLNC mutation p.R2187P. From this patient-specific iPSC line, a corresponding isogenic control line was created by CRISPR/Cas9 genome editing. Both, the patient-specific and isogenic-control iPSC maintained full pluripotency, genomic integrity, and in vitro differentiation capacity. All iPSC lines differentiate into iPSC-cardiomyocytes, hence providing the possibility to study the pathogenesis of FLNC-mediated DCM further.

Asunto(s)

Sistemas CRISPR-Cas , Cardiomiopatía Dilatada , Filaminas , Células Madre Pluripotentes Inducidas , Humanos , Cardiomiopatía Dilatada/genética , Cardiomiopatía Dilatada/patología , Sistemas CRISPR-Cas/genética , Células Madre Pluripotentes Inducidas/metabolismo , Filaminas/genética , Filaminas/metabolismo , Mutación , Diferenciación Celular , Línea Celular , Masculino

RESUMEN

Forensic pathologists are frequently asked to investigate cases of sudden death (SD), and identifying the cause of death can be of particular importance, especially where it may be necessary to perform family screening among the relatives of the victim. A multidisciplinary approach inclusive of genetic analysis is therefore strongly recommended. According to forensic practice, arrhythmogenic cardiomyopathy (ACM) is a well-known cause of SD. However, cases of SD caused by a left ventricular pattern of ACM diagnosed at autopsy are rarely reported in the literature. We present the case of an apparently healthy, 37-year-old male found dead at his home. At autopsy, multiple foci of epicardial and mid-wall fibrous and fibro-adipose tissue were observed within the left ventricle and, to a lesser extent, within the interventricular septum. Toxicology was negative, whereas a filamin C truncating mutation was detected through genetic analysis. To our knowledge, this is the first instance of arrhythmogenic left ventricular cardiomyopathy being diagnosed at autopsy.

Asunto(s)

Filaminas , Mutación , Humanos , Masculino , Adulto , Filaminas/genética , Autopsia , Displasia Ventricular Derecha Arritmogénica/genética , Ventrículos Cardíacos/patología , Patologia Forense/métodos , Muerte Súbita Cardíaca/etiología

RESUMEN

OBJECTIVE: The contribution of somatic variants to epilepsy has recently been demonstrated, particularly in the etiology of malformations of cortical development. The aim of this study was to determine the diagnostic yield of somatic variants in genes that have been previously associated with a somatic or germline epilepsy model, ascertained from resected brain tissue from patients with multidrug-resistant focal epilepsy. METHODS: Forty-two patients were recruited across three categories: (1) malformations of cortical development, (2) mesial temporal lobe epilepsy with hippocampal sclerosis, and (3) nonlesional focal epilepsy. Participants were subdivided based on histopathology of the resected brain. Paired blood- and brain-derived DNA samples were sequenced using high-coverage targeted next generation sequencing to high depth (585× and 1360×, respectively). Variants were identified using Genome Analysis ToolKit (GATK4) MuTect-2 and confirmed using high-coverage Amplicon-EZ sequencing. RESULTS: Sequence data on 41 patients passed quality control. Four somatic variants were validated following amplicon sequencing: within CBL, ALG13, MTOR, and FLNA. The diagnostic yield across 41 patients was 10%, 9% in mesial temporal lobe epilepsy with hippocampal sclerosis and 20% in malformations of cortical development. SIGNIFICANCE: This study provides novel insights into the etiology of mesial temporal lobe epilepsy with hippocampal sclerosis, highlighting a potential pathogenic role of somatic variants in CBL and ALG13. We also report candidate diagnostic somatic variants in FLNA in focal cortical dysplasia, while providing further insight into the importance of MTOR and related genes in focal cortical dysplasia. This work demonstrates the potential molecular diagnostic value of variants in both germline and somatic epilepsy genes.

Asunto(s)

Epilepsia Refractaria , Epilepsia del Lóbulo Temporal , Esclerosis del Hipocampo , Adolescente , Adulto , Niño , Preescolar , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven , Epilepsia Refractaria/genética , Epilepsia Refractaria/etiología , Epilepsia Refractaria/patología , Epilepsia del Lóbulo Temporal/genética , Epilepsia del Lóbulo Temporal/patología , Filaminas/genética , Variación Genética , Esclerosis del Hipocampo/genética , Esclerosis del Hipocampo/patología , Malformaciones del Desarrollo Cortical/genética , Malformaciones del Desarrollo Cortical/complicaciones , Malformaciones del Desarrollo Cortical/patología

RESUMEN

A late adolescent primigravida was found to have a fetus with a cystic hygroma and significant shortening of the limbs on first-trimester ultrasound. She underwent chorionic villus sampling with normal microarray result. In the early second trimester, the fetus was found to have the absence of all four limbs and a thorough skeletal dysplasia workup was pursued, identifying a variant in the FLNB gene (c.62C>G). The patient underwent termination of pregnancy. The care of this patient was expedited by first-trimester sonographic evidence of limb abnormalities enabling timely clinical management.

Asunto(s)

Enfermedades Fetales , Linfangioma Quístico , Osteocondrodisplasias , Embarazo , Femenino , Adolescente , Humanos , Enfermedades Fetales/genética , Primer Trimestre del Embarazo , Ultrasonografía , Mutación , Ultrasonografía Prenatal , Filaminas/genética

RESUMEN

Truncating mutations in filamin C (FLNC) are associated with dilated cardiomyopathy and arrhythmogenic cardiomyopathy. FLNC is an actin-binding protein and is known to interact with transmembrane and structural proteins; hence, the ablation of FLNC in cardiomyocytes is expected to dysregulate cell adhesion, cytoskeletal organization, sarcomere structural integrity, and likely nuclear function. Our previous study showed that the transcriptional profiles of FLNC homozygous deletions in human pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are highly comparable to the transcriptome profiles of hiPSC-CMs from patients with FLNC truncating mutations. Therefore, in this study, we used CRISPR-Cas-engineered hiPSC-derived FLNC knockout cardiac myocytes as a model of FLNC cardiomyopathy to determine pathogenic mechanisms and to examine structural changes caused by FLNC deficiency. RNA sequencing data indicated the significant upregulation of focal adhesion signaling and the dysregulation of thin filament genes in FLNC-knockout (FLNCKO) hiPSC-CMs compared to isogenic hiPSC-CMs. Furthermore, our findings suggest that the complete loss of FLNC in cardiomyocytes led to cytoskeletal defects and the activation of focal adhesion kinase. Pharmacological inhibition of PDGFRA signaling using crenolanib (an FDA-approved drug) reduced focal adhesion kinase activation and partially normalized the focal adhesion signaling pathway. The findings from this study suggest the opportunity in repurposing FDA-approved drug as a therapeutic strategy to treat FLNC cardiomyopathy.

Asunto(s)

Cardiomiopatías , Filaminas , Células Madre Pluripotentes Inducidas , Humanos , Cardiomiopatías/metabolismo , Filaminas/genética , Filaminas/metabolismo , Proteína-Tirosina Quinasas de Adhesión Focal/metabolismo , Células Madre Pluripotentes Inducidas/metabolismo , Miocitos Cardíacos/metabolismo , Proteínas Tirosina Quinasas Receptoras/metabolismo , Sarcómeros/metabolismo , Transducción de Señal

RESUMEN

Here we introduce the human induced pluripotent stem cell lines (hiPSCs), HIMRi004-A and HIMRi005-A from dermal fibroblasts of a 48-year-old female (HIMRi004-A) carrying missense mutation that translate to the first described filamin C isoform p.W2710X and from a 56-year-old female (HIMRi005-A) carrying a recently described mutation in the same domain p.Y2704X. Both lines are generated via lentiviral expression of OCT4, SOX2, KLF4 and c-MYC. The lines display a typical embryonic stem cell-like morphology, express pluripotency markers, retain a normal karyotype (46, XX) and have the differentiation capacity in all three germ layers. The two lines can be used to elucidate the pathomechanisms of FLNC myofibrillar myopathies and to develop novel therapeutic options.

Asunto(s)

Células Madre Pluripotentes Inducidas , Femenino , Humanos , Persona de Mediana Edad , Diferenciación Celular/genética , Línea Celular , Dimerización , Fibroblastos/metabolismo , Filaminas/genética , Filaminas/metabolismo , Células Madre Pluripotentes Inducidas/metabolismo , Factor 4 Similar a Kruppel , Mutación/genética

RESUMEN

Triple-negative breast cancer is a rare but highly heterogeneous breast cancer subtype with a limited choice of specific treatments. Chemotherapy remains the only efficient treatment, but its side effects and the development of resistance consolidate the urgent need to discover new targets. In TNBC, filamin A expression correlates to grade and TNM stage. Accordingly, this protein could constitute a new target for this BC subtype. Even if most of the data indicates its direct involvement in cancer progression, some contrasting results underline the need to deepen the studies. To elucidate a possible function of this protein as a TNBC marker, we summarized the main characteristic of filamin A and its involvement in physiological and pathological processes such as cancer. Lastly, we scrutinized its actions in triple-negative breast cancer and highlighted the need to increase the number of studies useful to better clarify the role of this versatile protein as a marker and target in TNBC, alone or in "collaboration" with other proteins with a relevant role in this BC subgroup.

Asunto(s)

Neoplasias de la Mama Triple Negativas , Humanos , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Neoplasias de la Mama Triple Negativas/patología , Filaminas/genética