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The decades‐old cholinergic hypothesis of Alzheimer's disease (AD) led to clinical testing and FDA approval of acetylcholinesterase inhibitor drugs. Subsequently, the α7 nicotinic acetylcholine receptor (α7nAChR) was proposed as a new drug target for enhancing cholinergic neurotransmission. Nearly simultaneously, soluble amyloid β1‐42 (Aβ42) was shown to bind α7nAChR with picomolar affinity to activate kinases that hyperphosphorylate tau, the precursor to tau‐containing tangles. Multiple biopharmaceutical companies explored α7nAChR as a drug target for AD, mostly to enhance neurotransmission. Directly targeting α7nAChR proved to be a drug development challenge. The ultra‐high‐affinity interaction between Aβ42 and α7nAChR posed a significant hurdle for direct competition in the AD brain. The receptor rapidly desensitizes, undermining efficacy of agonists. Drug discovery approaches therefore included partial agonists and allosteric modulators of α7nAChR. After substantial effort, numerous drug candidates were abandoned due to lack of efficacy or drug‐related toxicities. As alternatives, proteins interacting with α7nAChR were sought. In 2016, a novel nAChR regulator was identified, but no drug candidates have emerged from this effort. In 2012, the interaction of filamin A with α7nAChR was shown to be critical to Aβ42's toxic signaling via α7nAChR, presenting a new drug target. The novel drug candidate simufilam disrupts the filamin A–α7nAChR interaction, reduces Aβ42's high‐affinity binding to α7nAChR, and suppresses Aβ42's toxic signaling. Early clinical trials of simufilam showed improvements in experimental CSF biomarkers and indications of cognitive improvement in mild AD patients at 1 year. Simufilam is currently in phase 3 clinical trials as a disease‐modifying treatment for AD. [ABSTRACT FROM AUTHOR]

Down syndrome is the most common chromosomal abnormality in humans. Patients with Down syndrome have hematologic disorders, including mild to moderate thrombocytopenia. In case of Down syndrome, thrombocytopenia is not associated with bleeding, and it remains poorly characterized regarding molecular mechanisms. We investigated the effects of overexpression of Dyrk1A, an important factor contributing to some major Down syndrome phenotypes, on platelet number and bleeding in mice. Mice overexpressing Dyrk1A have a decrease in platelet number by 20%. However, bleeding time was found to be reduced by 50%. The thrombocytopenia and the decreased bleeding time observed were not associated to an abnormal platelet receptors expression, to a defect of platelet activation by ADP, thrombin or convulxin, to the presence of activated platelets in the circulation or to an abnormal half‐life of the platelets. To propose molecular mechanisms explaining this discrepancy, we performed a network analysis of Dyrk1A interactome and demonstrated that Dyrk1A, fibronectin and fibrinogen interact indirectly through two distinct clusters of proteins. Moreover, in mice overexpressing Dyrk1A, increased plasma fibronectin and fibrinogen levels were found, linked to an increase of the hepatic fibrinogen production. Our results indicate that overexpression of Dyrk1A in mice induces decreased bleeding consistent with increased plasma fibronectin and fibrinogen levels, revealing a new role of Dyrk1A depending on its indirect interaction with these two proteins. [ABSTRACT FROM AUTHOR]

A‐to‐I RNA editing by ADARs is an abundant epitranscriptomic RNA‐modification in metazoa. In mammals, Flna pre‐mRNA harbours a single conserved A‐to‐I RNA editing site that introduces a Q‐to‐R amino acid change in Ig repeat 22 of the encoded protein. Previously, we showed that FLNA editing regulates smooth muscle contraction in the cardiovascular system and affects cardiac health. The present study investigates how ADAR2‐mediated A‐to‐I RNA editing of Flna affects actin crosslinking, cell mechanics, cellular adhesion and cell migration. Cellular assays and AFM measurements demonstrate that the edited version of FLNA increases cellular stiffness and adhesion but impairs cell migration in both, mouse fibroblasts and human tumour cells. In vitro, edited FLNA leads to increased actin crosslinking, forming actin gels of higher stress resistance. Our study shows that Flna RNA editing is a novel regulator of cytoskeletal organisation, affecting the mechanical property and mechanotransduction of cells. [ABSTRACT FROM AUTHOR]

Pathogenic variants of the X‐linked FLNA gene encoding filamin A protein have been associated with a wide spectrum of symptoms, including the recently described pulmonary phenotype with childhood‐onset panlobular emphysema. We describe three female patients from two families with novel heterozygous FLNA variants c.5837_2del and c.508C > T. Analysis of immunofluorescence of peripheral blood smears and platelet function was performed for all patients. FLNA‐negative platelets were observed, suggesting that these variants result in the loss of a functional protein product. All three patients also had periventricular nodular heterotopia and panlobular emphysema. However, they had considerably milder symptoms and later age of onset than in the previously reported cases. Therefore, patients with pathogenic FLNA variants should be studied actively for lung involvement even in the absence of pronounced respiratory symptoms. Conversely, any patient with unexplained panlobular emphysema should be analyzed for pathogenic FLNA variants. We also suggest that immunofluorescence analysis is a useful tool for investigating the pathogenicity of novel FLNA variants. [ABSTRACT FROM AUTHOR]

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.

Background: Congenital short‐bowel syndrome (CSBS) is a rare disorder characterized by retardation of intestinal development. However, it is still not well recognized at present. In this study, the etiological, clinical, and genetic characteristics of CSBS in China were analyzed. Methods: Nine infants with CSBS were recruited. Full‐thickness biopsy findings were evaluated by histopathology. Whole‐exome sequencing was performed to identify mutations in patients and their family members. All patients were followed up at >1 year of age. Results: Six of 9 infants had malrotation, and 2 patients had intestinal atresia. The average total small‐bowel length was 51.7 (40–75) cm. Coxsackie and adenovirus receptor‐like membrane protein (CLMP) mutations were found in 5 patients and were related to decreases in ileal goblet cells and mucous secretion. Among these 5 patients, 3 shared the same mutation (c. 206G>A p.R69H), 1 patient had an exon 3–5 deletion, and 1 patient had the C.655T>G, p.Cys219Gly, and C.389‐2A>C. Another case carried a loss‐of‐function mutation in filamin A (FLNA). In the other 3 patients, no pathogenic mutations in genes related to intestinal development were found. The rate of catheter‐related bloodstream infection was 4.3 per 1000 catheter days, and intestinal failure–associated liver disease (IFALD) was 77.8%. The median follow‐up duration was 24.1 months. Eight patients were weaned off parenteral nutrition (PN). Six patients still exhibited malnutrition during follow‐up. Conclusions: Infants with CSBS often need long‐term PN and remain at risk of SBS‐related complications. CLMP and FLNA mutations are associated with CSBS in the Chinese population. [ABSTRACT FROM AUTHOR]

Terminal osseous dysplasia with pigmentary defects (TODPD; MIM #300244) is an extremely rare, X‐linked dominant, in utero male‐lethal disease, characterized by skeletal dysplasia of the limbs, pigmentary defects of the skin, and recurrent digital fibromatosis of childhood. Delayed/abnormal ossification of bones of the hands and feet, joint contractures, and dysmorphic facial features may accompany. A single recurrent mutation (c.5217 G>A) of the FLNA gene which causes cryptic splicing was identified as the cause of the disease. We here present the first TODPD case from Turkey with full‐blown phenotype who exhibit unique additional findings, hypopigmented patch on the lower extremity following Blaschko's lines and smooth muscle hamartoma of the scalp in review of all the previously reported TODPD cases. [ABSTRACT FROM AUTHOR]

Abstract: 4‐amino‐2‐trifluoromethyl‐phenyl retinate (ATPR) was able to induce the G0/G1 phase arrest in gastric cancer SGC‐7901 cells by downregulating 14‐3‐3ε. However, the mechanisms underlying this effect have not been fully elucidated. Because 14‐3‐3ε functions as a molecular chaperone on cell cycle regulation, the interaction between 14‐3‐3ε and the target proteins is worth an in‐depth study. In this study, the use of targeting proteomics identified 352 14‐3‐3ε‐binding proteins in SGC‐7901 cells. Analysis of gene ontology (GO) was performed using PANTHER to annotate the biological processes, protein classes, and pathways of these proteins. In 25 cell cycle‐related proteins, filamin A was reduced following ATPR treatment, and this change was validated by immunoprecipitation. The cell cycle was arrested at the G0/G1 phase following ATPR treatment or filamin A silencing in SGC‐7901 cells. Furthermore, subcellular expression analysis showed that 14‐3‐3ε and filamin A were transferred from the cytoplasm to the nucleus after ATPR treatment. On the other hand, overexpression of 14‐3‐3ε, in SGC‐7901 cells, resulted in an increase in the total cellular level of filamin A and an increase in the subcellular localization of filamin A in the cytoplasm. ATPR treatment of the 14‐3‐3ε overexpression cells decreased the total level of filamin A and redistributed filamin A protein from the cytoplasm to the nucleus. Immunohistochemical analysis showed that the expression levels of 14‐3‐3ε and filamin A in gastric cancer tissues were significantly higher, with a predominant localization in the cytoplasm, compared to the levels in matched tissues. Taken together, our results suggest that ATPR can induce nuclear localization of filamin A by reducing the binding of 14‐3‐3ε and filamin A, which may be the mechanism of ATPR‐induced G0/G1 phase arrest. [ABSTRACT FROM AUTHOR]

The pharmacological therapy of GH‐secreting pituitary tumors is based on somatostatin (SS) analogs that reduce GH secretion and cell proliferation by binding mainly SS receptors type 2 (SST2). Antimigratory effects of SS have been demonstrated in different cell models, but no data on pituitary tumors are available. Aims of our study were to evaluate SST2 effects on migration and invasion of human and rat tumoral somatotrophs, and to elucidate the molecular mechanism involved focusing on the role of cofilin and filamin A (FLNA). Our data revealed that SST2 agonist BIM23120 significantly reduced GH3 cells migration (−22% ± 3.6%, p < 0.001) and invasion on collagen IV (−31.3% ± 12.2%, p < 0.01), both these effects being reproduced by octreotide and pasireotide. Similar results were obtained in primary cultured cells from human GH‐secreting tumors. These inhibitory actions were accompanied by a marked increase in RhoA/ROCK‐dependent cofilin phosphorylation (about 2.7‐fold in GH3 and 2.1‐fold in human primary cells). Accordingly, the anti‐invasive effect of the SS analog was mimicked by the overexpression in GH3 cells of the S3D phosphomimetic cofilin mutant, and abolished by both phosphodeficient S3A cofilin and a specific ROCK inhibitor that prevented cofilin phosphorylation. Moreover, FLNA silencing and FLNA dominant‐negative mutants FLNA19‐20 and FLNA21‐24 transfection demonstrated that FLNA plays a scaffold function for SST2‐mediated cofilin phosphorylation. Accordingly, cofilin recruitment to agonist‐activated SST2 was completely lost in FLNA silenced cells. In conclusion, we demonstrated that SST2 inhibits rat and human tumoral somatotrophs migration and invasion through a molecular mechanism that involves FLNA‐dependent cofilin recruitment and phosphorylation. [ABSTRACT FROM AUTHOR]

Androgenic actions require the proper signal transmission by the androgen receptor (AR), a nuclear transcription factor. This is initially located in the cell cytoplasm and should translocates to the nucleus to interact with DNA. AR functional impairment causes diverse blockage degrees of androgenic steroid action, known as androgen insensitivity syndromes. Filamin A, a protein coded by the FLNA gene, is a co-activator of various cytoplasmic factors, including AR. The mutational inactivation of the FLNA gene induces insufficiency of translocation and activation of AR. Consequently, it causes a developmental disorder of the male gonad and hypogonadism, similar to those observed in partial androgen insensitivity. We report two brothers carrying a loss-of-function mutation of FNLA with gonadal differentiation disorder and hypospadias. Specific staining for AR shows almost an absolute absence of these receptors in the testicular tissue. This association recommends investigating a possible mutational inactivation of the FLNA gene in patients with cryptorchidism and epididymo-testicular dissociation. The study is especially indicated when the family history, more often that of the mother, is suggestive. Likewise, growth and gonadal development of all male patients carrying this genetic trait should be monitored since childhood. [ABSTRACT FROM AUTHOR]

In this review, we focus on the role played by the protein partners of ligand-activated extranuclear androgen receptor (AR) in the final effects of hormone action, such as proliferation, migration, and neuritogenesis. The choice of AR partner, at least in part, depends on cell type. Androgen-activated receptor directly associates with cytoplasmic Src tyrosine kinase in epithelial cells, whereas in mesenchymal and neuronal cells, it prevalently interacts with filamin A. In the former, proliferation represents the final hormonal outcome, whereas in the latter, either migration or neuritogenesis, respectively, occurs. Furthermore, AR partner filamin A is replaced with Src when mesenchymal cells are stimulated with very low androgen concentrations. Consequently, the migratory effect is replaced by mitogenesis. Use of peptides that prevent receptor/partner assembly abolishes the effects that are dependent on their association and offers new therapeutic approaches to AR-related diseases. Perturbation of migration is often associated with metastatic spreading in cancer. In turn, cell cycle aberration causes tumors to grow faster, whereas toxic signaling triggers neurodegenerative events in the CNS. Here, we provide examples of new tools that interfere in rapid androgen effects, including migration, proliferation, and neuronal differentiation, together with their potential therapeutic applications in AR-dependent diseases--mainly prostate cancer and neurodegenerative disorders. [ABSTRACT FROM AUTHOR]

Key points Ion channels are transmembrane proteins that are synthesized within the cells but need to be trafficked to the cell membrane for the channels to function., Small-conductance, Ca2+-activated K+ channels (SK, KCa2) are unique subclasses of K+ channels that are regulated by Ca2+ inside the cells; they are expressed in human atrial myocytes and responsible for shaping atrial action potentials., We have previously shown that interacting proteins of SK2 channels are important for channel trafficking to the membrane., Using total internal reflection fluorescence (TIRF) and confocal microscopy, we studied the mechanisms by which the surface membrane localization of SK2 (KCa2.2) channels is regulated by their interacting proteins., Understanding the mechanisms of SK channel trafficking may provide new insights into the regulation controlling the repolarization of atrial myocytes., Abstract The normal function of ion channels depends critically on the precise subcellular localization and the number of channel proteins on the cell surface membrane. Small-conductance, Ca2+-activated K+ channels (SK, KCa2) are expressed in human atrial myocytes and are responsible for shaping atrial action potentials. Understanding the mechanisms of SK channel trafficking may provide new insights into the regulation controlling the repolarization of atrial myocytes. We have previously demonstrated that the C- and N-termini of SK2 channels interact with the actin-binding proteins α-actinin2 and filamin A, respectively. However, the roles of the interacting proteins on SK2 channel trafficking remain incompletely understood. Using total internal reflection fluorescence (TIRF) microscopy, we studied the mechanisms of surface membrane localization of SK2 (KCa2.2) channels. When SK2 channels were co-expressed with filamin A or α-actinin2, the membrane fluorescence intensity of SK2 channels increased significantly. We next tested the effects of primaquine and dynasore on SK2 channels expression. Treatment with primaquine significantly reduced the membrane expression of SK2 channels. In contrast, treatment with dynasore failed to alter the surface membrane expression of SK2 channels. Further investigations using constitutively active or dominant-negative forms of Rab GTPases provided additional insights into the distinct roles of the two cytoskeletal proteins on the recycling processes of SK2 channels from endosomes. α-Actinin2 facilitated recycling of SK2 channels from both early and recycling endosomes while filamin A probably aids the recycling of SK2 channels from recycling endosomes. [ABSTRACT FROM AUTHOR]

Filamin A is an X-linked, ubiquitous actin-binding protein whose mutations are associated to multiple disorders with limited genotype-phenotype correlations. While gain-of-function mutations cause various bone dysplasias, loss-of-function variants are the most common cause of periventricular nodular heterotopias with variable soft connective tissue involvement, as well as X-linked cardiac valvular dystrophy (XCVD). The term 'Ehlers-Danlos syndrome (EDS) with periventricular heterotopias' has been used in females with neurological, cardiovascular, integument and joint manifestations, but this nosology is still a matter of debate. We report the clinical and molecular update of an Italian family with an X-linked recessive soft connective tissue disorder and which was described, in 1975, as the first example of EDS type V of the Berlin nosology. The cutaneous phenotype of the index patient was close to classical EDS and all males died for a lethal cardiac valvular dystrophy. Whole exome sequencing identified the novel c.1829-1G>C splice variation in FLNA in two affected cousins. The nucleotide change was predicted to abolish the canonical splice acceptor site of exon 13 and to activate a cryptic acceptor site 15 bp downstream, leading to in frame deletion of five amino acid residues (p.Phe611_Gly615del). The predicted in frame deletion clusters with all the mutations previously identified in XCVD and falls within the N-terminus rod 1 domain of filamin A. Our findings expand the male-specific phenotype of FLNA mutations that now includes classical-like EDS with lethal cardiac valvular dystrophy, and offer further insights for the genotype-phenotype correlations within this spectrum. © 2016 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

We further evaluated a previously reported family with an apparently undescribed X-linked syndrome involving joint contractures, keloids, an increased optic cup-to-disc ratio, and renal stones to elucidate the genetic cause. To do this, we obtained medical histories and performed physical examination on 14 individuals in the family, five of whom are affected males and three are obligate carrier females. Linkage analysis was performed on all but one individual and chromosome X-exome sequencing was done on two affected males. The analysis localized the putative gene to Xq27-qter and chromosome X-exome sequencing revealed a mutation in exon 28 (c.4726G>A) of the filamin A ( FLNA) gene, predicting that a conserved glycine had been replaced by arginine at amino acid 1576 (p.G1576R). Segregation analysis demonstrated that all known carrier females tested were heterozygous (G/A), all affected males were hemizygous for the mutation (A allele) and all normal males were hemizygous for the normal G allele. The data and the bioinformatic analysis indicate that the G1576R mutation in the FLNA gene is very likely pathogenic in this family. The syndrome affecting the family shares phenotypic overlap with other syndromes caused by FLNA mutations, but appears to be a distinct phenotype, likely representing a unique genetic syndrome. © 2016 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Otopalatodigital spectrum disorders ( OPDSD) include OPD syndromes types 1 and type 2 ( OPD1, OPD2), Melnick-Needles syndrome ( MNS), and frontometaphyseal dysplasia ( FMD). These conditions are clinically characterized by variable skeletal dysplasia associated in males, with extra-skeletal features including brain malformations, cleft palate, cardiac anomalies, omphalocele and obstructive uropathy. Mutations in the FLNA gene have been reported in most FMD and OPD2 cases and in all instances of typical OPD1 and MNS. Here, we report a series of 10 fetuses and a neonatally deceased newborn displaying a multiple congenital anomalies syndrome suggestive of OPDSD and in whom we performed FLNA analysis. We found a global mutation rate of 44%. This series allows expanding the clinical and FLNA mutational spectrum in OPDSD. However, we emphasize difficulties to correctly discriminate OPDSD based on clinical criteria in fetuses due to the major overlap between these conditions. Molecular analyses may help pathologists to refine clinical diagnosis according to the type and the location of FLNA mutations. Discriminating the type of OPDSD is of importance in order to improve the genetic counseling to provide to families. [ABSTRACT FROM AUTHOR]

Terminal osseous dysplasia with pigmentary defects (TODPD) is a rare, X-linked syndrome classically characterized by distal limb anomalies, pigmented skin defects of the face, and recurrent digital fibromas. X-inactivation plays a major role in determining the range of phenotypic expression. Thus, patients can demonstrate a wide spectrum of disease severity, making accurate diagnosis more challenging. Recent studies have identified a FLNA c.5217G>A mutation as the cause of TODPD, allowing for diagnostic genetic testing. We present a case of molecularly confirmed TODPD in a girl with the 47,XXX chromosomal complement and deformities of the hands and feet, craniofacial abnormalities, and discolored, linear facial lesions. Skin biopsy of the patient's facial lesion revealed absent papillary dermal elastic fibers, consistent with anetoderma, which contrasts with the dermal hypoplasia described in the only other such facial biopsy reported in the literature. The finding of absent elastic fibers in the skin lesions suggests that mutated filamin A, in part, exerts its effects through dysregulated elastin biology, which may explain the nature of many connective tissue pleotropic effects in FLNA-related disorders. © 2015 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Frontometaphyseal dysplasia (FMD) is a distinctive sclerosing skeletal dysplasia associated with a number of non-skeletal manifestations including hearing loss, cardiac malformations, and stenosis, particularly of the upper airway and urinary tract. Some, but not all, patients have mutations in FLNA causing the condition. Consonant with the X chromosomal location of FLNA males are generally more severely affected than females. FLNA mutations can be detected in 82% of affected males. We describe seven patients (one male, six females) all of whom have the major clinical and radiological features of FMD, but without detectable mutations in FLNA. The females in our cohort are affected to a similar degree as is usually found in males. In addition, all patients have marked keloid formation at various body sites, including the eye, from an early age. Other features that may indicate a different etiology in these patients are the increased frequency of cleft palate, Robin sequence, tracheal stenosis, and mild intellectual disability, which all occur in three of more patients in the present group. All patients are isolated. We hypothesize that the presently reported patients represent further evidence that phenotypes strongly resembling FMD exist that are not accounted for by mutations in FLNA. Since the frequency of several of the manifestations, their sporadic presentations, and the presence of keloid formation differ from the X-linked form of this condition we propose de novo autosomal dominant acting mutations in a gene functionally related to FLNA, underpin this disorder. © 2015 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Terminal osseous dysplasia with pigmentary defects ( TODPD) is an X-linked dominant syndrome with distal limb anomalies, pigmentary skin defects, digital fibromas, and generalized bone involvement due to a recurrent mutation in the filamin A ( FLNA) gene. We here report the mutation c.5217G>A in FLNA in three families with TODPD and we found possible germline and somatic mosaicism in two out of the three families. The occurrence of somatic and germline mosaicism for TODPD indicates that caution should be taken in counseling recurrence risks for these conditions upon presentation of an isolated case. [ABSTRACT FROM AUTHOR]

Highlights: [•] Neuropilin-1 (Nrp1) bound filamin A (FlnA) directly. [•] Endothelial cells (ECs) expressing Nrp1 lacking a cytoplasmic domain migrated slower than wild type ECs. [•] Focal adhesion (FA) turnover in ECs expressing truncated Nrp1 was slower than in wild type ECs. [ABSTRACT FROM AUTHOR]

ABSTRACT Mutations in FLNA (Filamin A, OMIM 300017) cause X-linked periventricular nodular heterotopia (XL-PNH). XL-PNH-associated mutations are considered lethal in hemizygous males. However, a few males with unusual mutations (including distal truncating and hypomorphic missense mutations), and somatic mosaicism have been reported to survive past infancy. Two brothers had an atypical presentation with failure to thrive and distinct facial appearance including hypertelorism. Evaluations of these brothers and their affected cousin showed systemic involvement including severe intestinal malfunction, malrotation, congenital short bowel, PNH, pyloric stenosis, wandering spleen, patent ductus arteriosus, atrial septal defect, inguinal hernia, and vesicoureteral reflux. The unanticipated finding of PNH led to FLNA testing and subsequent identification of a novel no-stop FLNA mutation (c.7941_7942delCT, p.(*2648Serext*100)). Western blotting and qRT-PCR of patients' fibroblasts showed diminished levels of protein and mRNA. This FLNA mutation, the most distal reported so far, causes in females classical XL-PNH, but in males an unusual, multi-organ phenotype, providing a unique insight into the FLNA-associated phenotypes. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Periventricular nodular heterotopia (PNH) is a developmental disorder of the central nervous system, characterized by heterotopic nodules of gray matter resulting from disturbed neuronal migration. The most common form of bilateral PNH is X-linked dominant inherited, caused by mutations in the Filamin A gene ( FLNA) and associated with a wide variety of other clinical findings including congenital heart disease. The typical patient with FLNA-associated PNH is female and presents with difficult to treat seizures. In contrast, hemizygous FLNA loss of function mutations in males are reported to be perinatally lethal. In X-linked dominant traits like FLNA-associated PNH the causal mutation is commonly inherited from the mother. Here, we present an exceptional family with paternal transmission of classic bilateral FLNA-associated PNH from a mildly affected father with somatic and germline mosaicism for a c.5686G>A FLNA splice mutation to both daughters with strikingly variable clinical manifestation and PNH extent in cerebral MR imaging. Our observations emphasize the importance to consider in genetic counseling and risk assessment the rare genetic constellation of paternal transmission for families with X-linked dominant inherited FLNA-associated PNH. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Periventricular heterotopia (PH) is a disorder of neuronal migration during fetal development that is characterized by morphologically normal neurons being located in an anatomically abnormal position in the mature brain. PH is usually diagnosed in patients presenting with a seizure disorder, when neuroimaging demonstrates the ectopically placed nodules of neurons. PH is a genetically and phenotypically heterogeneous disorder. The most commonly identified genetic cause is the X-linked dominant inheritance of mutations in the Filamin A ( FLNA) gene. Multiple lines of evidence support the contribution of genetic factors in dyslexia. As dyslexia does not show a single-gene pattern of inheritance, it is classified as a complex genetic disorder. We have recently identified a specific reading fluency deficit in a variable group of patients with PH, in the context of normal intelligence. Here, we present a study of a mother-daughter pair who share bilateral widespread gray matter heterotopia caused by a novel mutation in FLNA and the same pattern of X-chromosome inactivation but who exhibit divergent reading and cognitive profiles. This novel observation highlights the uncertainty of using heterotopia anatomy in clinical practice to predict behavioral outcome. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Podosomes and invadopodia are actin-based structures at the ventral cell membrane, which have a role in cell adhesion, migration and invasion. Little is known about the differences and dynamics underlying these structures. We studied podosome-like structures of oral squamous carcinoma cells and invadopodia of their invasive variant that has undergone a spontaneous epithelial-mesenchymal transition (EMT). In 3D imaging, podosomes were relatively large structures that enlarged in time, whereas invadopodia of invasive cells remained small, but were more numerous, degraded more extracellular matrix (ECM) and were morphologically strikingly different from podosomes. In live-cell imaging, highly dynamic, invadopodia-embedded actin tails were frequently released and rocketed through the cytoplasm. Resembling invadopodia, we found new club-ended cell extensions in EMT-experienced cells, which contained actin, cortactin, vinculin and MT1-matrix metalloproteinase. These dynamic cell extensions degraded ECM and, in field emission scanning electron microscopy, protruded from the dorsal cell membrane. Plectin, αII-spectrin, talin and focal adhesion kinase immunoreactivities were detected in podosome rings, whereas they were absent from invadopodia. Tensin potentially replaced talin in invadopodia. Integrin α3β1 surrounded both podosomes and invadopodia, whereas integrin αvβ5 localized only to invadopodia heads. Pacsin 2, in conjunction with filamin A, was detected early in podosomes, whereas pacsin 2 was not found in invadopodia and filamin A showed delayed accumulation. Fluorescence recovery after photobleaching indicated faster reorganization of actin, cortactin and filamin A in podosomes compared to invadopodia. In conclusion, EMT affects the invasion machinery of oral squamous carcinoma cells. Non-invasive squamous carcinoma cells constitutively organize podosomes, whereas invasive cells form invadopodia. The club-ended cell extensions, or externalized invadopodia, are involved in ECM degradation and maintenance of contact to adhesion substrate and surrounding cells during invasion. [ABSTRACT FROM AUTHOR]

Abstract: Substantial actin remodelling occurs prior to mitosis as cells alter their shape in preparation for cytokinesis. In mammalian cells, mitosis is initiated by a heterodimer of cyclin B1 and the cyclin dependent kinase 1 (Cdk1) serine/threonine kinase. In this report. we show that human cyclin B1 binds the actin cross-linking protein Filamin-A (FLNa). The proteins co-immunoprecipitate and co-localize in mitotic human cells. We find that cyclin B1/Cdk1 can phosphorylate FLNa in vitro and reduce its ability to gelate actin. We have also identified serine 1436 as one FLNa residue phosphorylated by cyclin B1/Cdk1 in vitro. Our results suggest a role for cyclin B1/Cdk1 in FLNa-dependent actin remodelling. [Copyright &y& Elsevier]

Abstract: Filamin plays an important role in actin cytoskeleton organization, membrane stabilization, and anchoring of transmembrane proteins. Using short interfering RNA (siRNA) to selectively target the filamin A gene and silence its expression, we studied the role of filamin A in G protein coupled receptor (GPCR) signaling. Silencing of filamin A protein expression was determined by immunoblotting and immunofluorescence. Functional consequences of filamin A gene silencing were measured by studying its role in MAPK signaling pathways activated by the Ca2+-sensing receptor. This work defines filamin A involvement in GPCR signaling pathways and describes an additional method for studying its function. [Copyright &y& Elsevier]

The article presents a case study of a 5 month-old boy who was hospitalized for left hemiplegia and right hemianopsia. In scan imaging it was revealed that he had a thrombosis in the right sylvian artery. Also, a diagnosis of myelomonoblastic leukaemia with severe diffuse intravascular coagulopathy was made. The boy was given palliative care thereafter. He died 2 months after the admission.