Anoctamin 1 is Apically Expressed on Thyroid Follicular Cells and Contributes to ATP- and Calcium-Activated Iodide Efflux

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Mutant MYO1F alters the mitochondrial network and induces tumor proliferation in thyroid cancer

Familial aggregation is a significant risk factor for the development of thyroid cancer and Familial Non-Medullary Thyroid Cancer (FNMTC) accounts for 5-7% of all NMTC. Whole Exome Sequencing analysis in the family affected by FNMTC with oncocytic features where our group previously identified a predisposing locus on chromosome 19p13.2, revealed a novel heterozygous mutation (c.400G>A, NM_012335; p.Gly134Ser) in exon 5 of MYO1F, mapping to the linkage locus. In the thyroid FRTL-5 cell model stably expressing the mutant MYO1F p.Gly134Ser protein we observed an altered mitochondrial network, with increased mitochondrial mass and a significant increase of both intracellular and extracellular Reactive Oxygen Species, compared to cells expressing the wild-type protein or carrying the empty vector. The mutation conferred a significant advantage in colony formation, invasion and anchorage independent growth. These data were corroborated by in vivo studies in zebrafish, since we demonstrated that the mutant MYO1F p.Gly134Ser, when overexpressed, can induce proliferation in whole vertebrate embryos, compared to the wild-type one. MYO1F screening in additional 192 FNMTC families identified another variant in exon 7, which leads to exon skipping, and is predicted to alter the ATP-binding domain in MYO1F. Our study identified for the first time a role for MYO1F in NMTC. This article is protected by copyright. All rights reserved

Neural and neuropeptide control of airway smooth muscle in vitro

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Seronegative celiac disease: Shedding light on an obscure clinical entity

Background Although serological tests are useful for identifying celiac disease, it is well established that a minority of celiacs are seronegative. Aim To define the prevalence and features of seronegative compared to seropositive celiac disease, and to establish whether celiac disease is a common cause of seronegative villous atrophy. Methods Starting from 810 celiac disease diagnoses, seronegative patients were retrospectively characterized for clinical, histological and laboratory findings. Results Of the 810 patients, fourteen fulfilled the diagnostic criteria for seronegative celiac disease based on antibody negativity, villous atrophy, HLA-DQ2/-DQ8 positivity and clinical/histological improvement after gluten free diet. Compared to seropositive, seronegative celiac disease showed a significantly higher median age at diagnosis and a higher prevalence of classical phenotype (i.e., malabsorption), autoimmune disorders and severe villous atrophy. The most frequent diagnosis in the 31 cases with seronegative flat mucosa was celiac disease (45%), whereas other diagnoses were Giardiasis (20%), common variable immunodeficiency (16%) and autoimmune enteropathy (10%). Conclusions Although rare seronegative celiac disease can be regarded as the most frequent cause of seronegative villous atrophy being characterized by a high median age at diagnosis; a close association with malabsorption and flat mucosa; and a high prevalence of autoimmune disorders

Features and Progression of Potential Celiac Disease in Adults

Background & Aims: Individuals with potential celiac disease have serologic and genetic markers of the disease with little or no damage to the small intestinal mucosa. We performed a prospective study to learn more about disease progression in these people. Methods: We collected data from 77 adults (59 female; median age, 33 years) diagnosed with potential celiac disease (on the basis of serology and HLA type) at Bologna University in Italy from 2004 through 2013. The subjects had normal or slight inflammation of the small intestinal mucosa. Clinical, laboratory, and histologic parameters were evaluated at diagnosis and during a 3-year follow-up period. Results: Sixty-one patients (46 female; median age, 36 years) showed intestinal and extraintestinal symptoms, whereas the remaining 16 (13 female; median age, 21 years) were completely asymptomatic at diagnosis. All subjects tested positive for immunoglobulin A endomysial antibody and tissue transglutaminase antibody, except for 1 patient with immunoglobulin A deficiency; 95% of patients were carriers of HLA-DQ2. Duodenal biopsies from 26% patients had a Marsh score of 0, and 74% had a Marsh score of 1. A higher proportion of symptomatic patients had autoimmune disorders (36%) and antinuclear antibodies (41%) than asymptomatic patients (5% and 12.5%, respectively), and symptomatic patients were of older age at diagnosis (P <.05). Gluten withdrawal led to significant clinical improvement in all 61 symptomatic patients. The 16 asymptomatic patients continued on gluten-containing diets, and only 1 developed mucosal flattening; levels of anti-endomysial and tissue transglutaminase antibodies fluctuated in 5 of these patients or became undetectable. Conclusions: In a 3-year study of adults with potential celiac disease, we found most to have symptoms, but these improved on gluten withdrawal. Conversely, we do not recommend a gluten-free diet for asymptomatic adults with potential celiac disease because they do not tend to develop villous atrophy

Cell-based imaging of sodium iodide symporter activity with the yellow fluorescent protein variant YFP-H148Q/I152L

The sodium iodide symporter (NIS) mediates iodide (I(-)) transport in the thyroid gland and other tissues and is of increasing importance as a therapeutic target and nuclear imaging reporter. NIS activity in vitro is currently measured with radiotracers and electrophysiological techniques. We report on the development of a novel live cell imaging assay of NIS activity using the I(-)-sensitive and genetically encodable yellow fluorescent protein (YFP) variant YFP-H148Q/I152L. In FRTL-5 thyrocytes stably expressing YFP-H148Q/I152L, I(-) induced a rapid and reversible decrease in cellular fluorescence characterized by 1) high affinity for extracellular I(-) (35 muM), 2) inhibition by the NIS inhibitor perchlorate, 3) extracellular Na(+) dependence, and 4) TSH dependence, suggesting that fluorescence changes are due to I(-) influx via NIS. Individual cells within a population of FRTL-5 cells exhibited a 3.5-fold variation in the rate of NIS-mediated I(-) influx, illustrating the utility of YFP-H148Q/I152L to detect cell-to-cell difference in NIS activity. I(-) also caused a perchlorate-sensitive decrease in YFP-H148Q/I152L fluorescence in COS-7 cells expressing NIS but not in cells lacking NIS. These results demonstrate that YFP-H148Q/I152L is a sensitive biosensor of NIS-mediated I(-) uptake in thyroid cells and in nonthyroidal cells following gene transfer and suggest that fluorescence detection of cellular I(-) may be a useful tool by which to study the pathophysiology and pharmacology of NIS

Molecular pathology of thyroid tumours of follicular cells: a review of genetic alterations and their clinicopathological relevance

Thyroid cancer is the most common endocrine malignancy. Knowledge of the molecular pathology of thyroid tumours originating from follicular cells has greatly advanced in the past several years. Common molecular alterations, such as BRAF p.V600E, RAS point mutations, and fusion oncogenes (RET-PTC being the prototypical example), have been, respectively, associated with conventional papillary carcinoma, follicular-patterned tumours (follicular adenoma, follicular carcinoma, and the follicular variant of papillary carcinoma/non-invasive follicular thyroid neoplasm with papillary-like nuclear features), and with papillary carcinomas from young patients and arising after exposure to ionising radiation, respectively. The remarkable correlation between genotype and phenotype shows how specific, mutually exclusive molecular changes can promote tumour development and initiate a multistep tumorigenic process that is characterised by aberrant activation of mitogen-activated protein kinase and phosphoinositide 3-kinase/PTEN/AKT signalling. Molecular alterations are becoming useful biomarkers for diagnosis and risk stratification, and as potential treatment targets for aggressive forms of thyroid carcinoma. What follows is a review of the principal genetic alterations of thyroid tumours originating from follicular cells and of their clinicopathological relevance