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MacHado L.R.,University of Leicester | Hardwick R.J.,University of Leicester | Hardwick R.J.,Wellcome Trust Sanger Institute | Bowdrey J.,University of Leicester | And 5 more authors.
American Journal of Human Genetics | Year: 2012

Both sequence variation and copy-number variation (CNV) of the genes encoding receptors for immunoglobulin G (Fcγ receptors) have been genetically and functionally associated with a number of autoimmune diseases. However, the molecular nature and evolutionary context of this variation is unknown. Here, we describe the structure of the CNV, estimate its mutation rate and diversity, and place it in the context of the known functional alloantigen variation of these genes. Deletion of Fcγ receptor IIIB, associated with systemic lupus erythematosus, is a result of independent nonallelic homologous recombination events with a frequency of approximately 0.1%. We also show that pathogen diversity, in particular helminth diversity, has played a critical role in shaping the functional variation at these genes both between mammalian species and between human populations. Positively selected amino acids are involved in the interaction with IgG and include some amino acids that are known polymorphic alloantigens in humans. This supports a genetic contribution to the hygiene hypothesis, which states that past evolution in the context of helminth diversity has left humans with an array of susceptibility alleles for autoimmune disease in the context of a helminth-free environment. This approach shows the link between pathogens and autoimmune disease at the genetic level and provides a strategy for interrogating the genetic variation underlying autoimmune-disease risk and infectious-disease susceptibility. © 2012 by The American Society of Human Genetics. All rights reserved. Source

Losito L.,Scientific Institute IRCCS Eugenio Medea
Journal of child neurology | Year: 2013

The diagnosis of Moebius syndrome, a rare congenital disorder, is primarily based on congenital facial and abducent nerve palsy. Involvement of other cranial nerves is also common. Occasionally the V, X, XI, and XII cranial nerves are involved, resulting in a difficulty to chew, swallow, and cough, which often leads to respiratory complications. Mental retardation and autism have been reported in some cases. Moebius syndrome can be associated with orofacial anomalies and limb malformations. The authors describe a patient with a confirmed diagnosis of Moebius syndrome associated with hydrosyringomyelia. No case of Moebius syndrome involving primarily the spinal cord has been reported so far. This patient did not present with other factors directly linked to syringomyelia. Source

De Palma C.,University of Milan | Perrotta C.,University of Milan | Pellegrino P.,University of Milan | Clementi E.,University of Milan | And 3 more authors.
Frontiers in Aging Neuroscience | Year: 2014

Muscular dystrophies are a group of genetic and heterogeneous neuromuscular disorders characterised by the primary wasting of skeletal muscle. In Duchenne muscular dystrophy (DMD), the most severe form of these diseases, the mutations in the dystrophin gene lead to muscle weakness and wasting, exhaustion of muscular regenerative capacity and chronic local inflammation leading to substitution of myofibres by connective and adipose tissue. DMD patients suffer of continuous and progressive skeletal muscle damage followed by complete paralysis and death, usually by respiratory and/or cardiac failure. No cure is yet available, but several therapeutic approaches aiming at reversing the ongoing degeneration have been investigated in preclinical and clinical settings. The autophagy is an important proteolytic system of the cell and has a crucial role in the removal of proteins, aggregates and organelles. Autophagy is constantly active in skeletal muscle and its role in tissue homeostasis is complex: at high levels it can be detrimental and contribute to muscle wasting; at low levels it can cause weakness and muscle degeneration, due to the unchecked accumulation of damaged proteins and organelles. The causal relationship between DMD pathogenesis and dysfunctional autophagy has been recently investigated. At molecular levels, the Akt axis is one of the key disregulated pathways, although the molecular events are not completely understood. The aim of this review is to describe and discuss the clinical relevance of the recent advances dissecting autophagy and its signalling pathway in DMD. The picture might pave the way for the development of interventions that are able to boost muscle growth and/or prevent muscle wasting. © 2014 De_palma, Perrotta, Pellegrino, Clementi and Cervia. Source

Perrotta C.,University of Milan | Cervia D.,University of Milan | Cervia D.,University of Tuscia | De Palma C.,University of Milan | And 5 more authors.
Apoptosis | Year: 2015

Autophagy, the main intracellular process of cytoplasmic material degradation, is involved in cell survival and death. Autophagy is regulated at various levels and novel modulators of its function are being continuously identified. An intriguing recent observation is that among these modulators is the sphingolipid metabolising enzyme, Acid Sphingomyelinase (A-SMase), already known to play a fundamental role in apoptotic cell death participating in several pathophysiological conditions. In this review we analyse and discuss the relationship between autophagy and A-SMase describing how A-SMase may regulate it and defining, for the first time, the existence of an A-SMase-autophagy axis. The imbalance of this axis plays a role in cancer, nervous system, cardiovascular, and hepatic disorders. © 2015 Springer Science+Business Media. Source

Cazzato D.,University of Milan | Assi E.,University of Milan | Moscheni C.,University of Milan | Brunelli S.,University of Milan Bicocca | And 7 more authors.
Experimental Cell Research | Year: 2014

The muscle-specific variant of neuronal nitric oxide (NO) synthase (NOS-I), is developmentally regulated in mouse suggesting a role of NO during myogenesis. In chick embryo, a good model of development, we found that the expression of NOS-I is up-regulated, but only in the early phase of development. Through a pharmacological intervention in ovo we found that NO signalling plays a relevant role during embryonic development. The inhibition of NOS-I decreased the growth of embryo, in particular of muscle tissue, while the restoring of physiological NO levels, via administration of a NO donor, reversed this effect. We found a selective action of NO, produced by NOS-I, on regulatory factors involved in myogenic differentiation in the early phase of chick embryo development: inhibition of NO generation leads to a decreased expression of the Myocyte enhancer factor 2a (Mef2a), Mef2c, Myogenin and Myosin, which was reversed by the administration of a NO donor. NO had no effects on Myf5 and MyoD, the myogenic regulatory factors necessary for myogenic determination. The action of NO on the myogenic regulatory factors was mediated via generation of cyclic GMP (cGMP) and activation of the cGMP-dependent protein kinase G (PKG). Finally we found in myoblasts in vitro that the activation of Mef2c was the key event mediating the NO-induced modulation of myogenesis.Our results identify NO produced by NOS-I as a key messenger in the early phase of embryonic development of chicken, acting as a critical determinant of myogenesis through its physiological cGMP/PKG pathway. © 2013 Elsevier Inc. Source

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