Showing papers by "Mirella Filocamo published in 2017"

Perturbations in cell signaling elicit early cardiac defects in mucopolysaccharidosis type II.

Abstract: Morphogens release and activity can be negatively affected by an impaired glycosaminoglycans (GAGs) turnover and proteoglycans assembly in the extracellular matrix, leading to altered tissue morphogenesis. In this work, we show that loss of Iduronate-2-sulfatase (IDS) activity, affecting GAGs catabolism and responsible for a life-threatening valvulopathy in mucopolysaccharidosis type II (MPSII), triggers early Sonic Hedgehog (Shh) and Wnt/β-catenin signaling defects, leading to aberrant heart development and atrioventricular valve formation in a zebrafish model. In addition, we consistently found impaired Shh signaling activity and cardiac electrophysiological abnormalities in IDS knockout mice at postnatal stages before any evident massive GAGs accumulation. These results suggest that IDS activity substantially affect cardiac morphogenesis through impaired Shh signaling and document an unexplored role of the enzyme in the fine-tuning of cell signaling pathways.

Norrbottnian clinical variant of Gaucher disease in Southern Italy.

Abstract: The Norrbottnian type of Gaucher disease (GD), as described many years ago, is due to a unique neuronopathic variant (c.1448T>G; L444P) that may have appeared during or before the sixteenth century in northern Sweden. It is a well-defined nosological entity with a characteristic course of clinical manifestations. In particular, Norrbottnian patients described in Sweden and Poland seem to share identical clinical histories characterized by the early onset of significant hepatosplenomegaly, often requiring splenectomy at an early age. Neurological involvement generally appears during the first or second decade of life, and includes horizontal gaze palsy, epilepsy, myoclonic movements, ataxia, dementia and cognitive impairment. Osteopenia occurs primarily in the spine, causing a severe and progressive thoracic kyphosis, although the involvement of other skeletal sites cannot be excluded. Here, we report on four Gaucher type 3 patients with Southern Italian ancestry presenting with clinical features and disease progression comparable to those of the ‘Norrbottnian’ Swedish phenotype, particularly regarding skeletal involvement with poor responsiveness to any therapeutical approach. Although a common ancestry among Southern Italian and Swedish Norrbottnian GD patients could not be investigated, the genotype [L444P]+[L444P] is the most frequently encountered in Southern Italy.

Biobanking for Genetic Diseases

Abstract: Biobanks are bioresources of human samples linked to relevant personal and health data of the participants, which are collected, processed and stored in an organised system. Their primary purpose is to provide biospecimens for researchers to help improve knowledge on human health and diseases, while appropriately protecting the interests, rights and privacy of the participants. The biobanking community poses a variety of legal, ethical, social and regulatory challenges, particularly involved in genetic diseases, to be overcome because of the sensitive data they store. A crucial avenue for a biobank to build and maintain public trust is therefore through the development of governance mechanisms ensuring that, in pursuing its remit, the biobank acts in compliance with the applicable laws and regulations of the country in which it is located, as well as the international regulations in order to ease the cross-border sample exchange and the international cooperation of biobanks. Key Concepts Biobanks are collections of human samples linked to relevant personal and health data of the participants, organised and managed in a systematic way. Primary purpose of biobanks is to help improve knowledge on human health and diseases. Biobanking poses a variety of challenges including ethical, legal and social issues (ELSI). Because of the preciousness of the samples and the sensitive nature of the data stored in biobanks, proper governance is essential to protecting confidentiality, choices and rights of participants. As critical components in the field of clinical practice and basic research, biobanks develop standard operating procedures devoted to collect, process, store, retrieve and transfer to researchers a set of biospecimens and associated information. In the field of rare diseases (RDs), collectively affecting 6–8% of the population, international cooperation among RD-biobanks is fundamental for sharing and achieving a critical mass of samples and data for basic, translational and clinical research. To ease an international cooperation, biobanks also need to act in compliance with international regulations. Keywords: biobanking; rare genetic diseases; networking; harmonisation and standardisation; ethical, legal and social issues (ELSI); IT structure; genetic data; privacy protection; governance; sustainability

In vitro recapitulation of the site-specific editing (to wild-type) of mutant IDS mRNA transcripts, and the characterization of IDS protein translated from the edited mRNAs

Abstract: The transfer of genomic information into the primary RNA sequence can be altered by RNA editing. We have previously shown that genomic variants can be RNA-edited to wild-type. The presence of distinct “edited” iduronate 2-sulfatase (IDS) mRNA transcripts ex vivo evidenced the correction of a nonsense and frameshift variant, respectively, in three unrelated Hunter syndrome patients. This phenomenon was confirmed in various patient samples by a variety of techniques, and was quantified by single-nucleotide primer extension. Western blotting also confirmed the presence of IDS protein similar in size to the wild-type. Since preliminary experimental evidence suggested that the “corrected” IDS proteins produced by the patients were similar in molecular weight and net charge to their wild-type counterparts, an in vitro system employing different cell types was established to recapitulate the site-specific editing of IDS RNA (uridine to cytidine conversion and uridine deletion), and to confirm the findings previously observed ex vivo in the three patients. In addition, confocal microscopy and flow cytometry analyses demonstrated the expression and lysosomal localization in HEK293 cells of GFP-labeled proteins translated from edited IDS mRNAs. Confocal high-content analysis of the two patients’ cells expressing wild-type or mutated IDS confirmed lysosomal localization and showed no accumulation in the Golgi or early endosomes.