A Novel Homozygous Variant in DYSF Gene Is Associated with Autosomal Recessive Limb Girdle Muscular Dystrophy R2/2B

Mutations in the DYSF gene, encoding dysferlin, are responsible for Limb Girdle Muscular Dystrophy type R2/2B (LGMDR2/2B), Miyoshi myopathy (MM), and Distal Myopathy with Anterior Tibialis onset (MDAT). The size of the gene and the reported inter and intra familial phenotypic variability make early diagnosis difficult. Genetic analysis was conducted using Next Gene Sequencing (NGS), with a panel of 40 Muscular Dystrophies associated genes we designed. In the present study, we report a new missense variant c.5033G>A, p.Cys1678Tyr ({"type":"entrez-nucleotide","attrs":{"text":"NM_003494","term_id":"1675063869"}}NM_003494) in the exon 45 of DYSF gene related to Limb Girdle Muscular Dystrophy type R2/2B in a 57-year-old patient affected with LGMD from a consanguineous family of south Italy. Both healthy parents carried this variant in heterozygosity. Genetic analysis extended to two moderately affected sisters of the proband, showed the presence of the variant c.5033G>A in both in homozygosity. These data indicate a probable pathological role of the variant c.5033G>A never reported before in the onset of LGMDR2/2B, pointing at the NGS as powerful tool for identifying LGMD subtypes. Moreover, the collection and the networking of genetic data will increase power of genetic-molecular investigation, the management of at-risk individuals, the development of new therapeutic targets and a personalized medicine.     

The Deubiquitinating Enzyme USP48 Interacts with the Retinal Degeneration-Associated Proteins UNC119a and ARL3

Proteins related to the ubiquitin-proteasome system play an important role during the differentiation and ciliogenesis of photoreceptor cells. Mutations in several genes involved in ubiquitination and proteostasis have been identified as causative of inherited retinal dystrophies (IRDs) and ciliopathies. USP48 is a deubiquitinating enzyme whose role in the retina is still unexplored although previous studies indicate its relevance for neurosensory organs. In this work, we describe that a pool of endogenous USP48 localises to the basal body in retinal cells and provide data that supports the function of USP48 in the photoreceptor cilium. We also demonstrate that USP48 interacts with the IRD-associated proteins ARL3 and UNC119a, and stabilise their protein levels using different mechanisms. Our results suggest that USP48 may act in the regulation/stabilisation of key ciliary proteins for photoreceptor function, in the modulation of intracellular protein transport, and in ciliary trafficking to the photoreceptor outer segment.     

Hydrous oxide formation on gold in base under potential cycling conditions

The formation of hydrous oxide films on gold in base under potential cycling conditions was investigated and found to be less inhibited than the same type of reaction observed when gold is strongly anodized at high potentials under d.c. conditions at high pH. The overall behaviour on cycling is quite similar to that observed with other metals, e.g. platinum. The importance of the lower limit, for instance, again appears to be related to the need under film thickening conditions to significantly reduce the compact oxide layer formed on the metal surface during the anodic sweep. It was noted that the earlier duplex model for this type of system, i.e. an inner compact and an outer dispersed oxide layer, is not always valid. Under certain conditions about six distinct peaks (suggesting six different states of gold oxide hydration, dispersion or polymerization) were observed in cathodic sweeps recorded for the reduction of thick films grown on gold under potential cycling conditions in base.     

Secretion of a bone resorbing factor by chick thyroid glands in organ culture

The ability of the thyroid gland to secrete a bone resorbing factor in vitro was studied using glands obtained from 20-day-old chick embryos. The glands were incubated in a modified BGJ medium containing 1 mg/ml bovine serum albumin under 5% CO2-40% O2 at 37 C. The culture media were assayed in vitro by measuring the stimulation of the release of previously incorporated 45Ca from cultured 19-day fetal rat bone shafts over a 48 h period. The glands secreted a stimulator of bone resorption which did not appear to be parathyroid hormone (PTH). The dose-response curve for the thyroid gland factor was not parallel to that obtained using PTH and secretion was not under calcium control. Neither thyroxine (T4) nor triiodothyronine (T3) produced a marked stimulation of bone resorption over a wide range of doses. Bone resorption stimulated by the thyroid gland factor was inhibited by calcitonin (CT). Concentrations of TH and thyroid gland factor which were minimally effective when tested separately, produced a marked synergistic response when added together. This synergism was not seen when T4, T3, PGE1, or PGE2 were tested with PTH. Media obtained by culturing explants of embryonic chick liver, heart and muscle did not have bone resorbing activity. Secretion of the bone resorbing factor by thyroid glands was blocked by Indomethacin (10(-5)M) but the effects of the factor on bone were not blocked by this agent. These results suggest that the thyroid gland is capable of secreting a stimulator of bone resorption, possibly a prostaglandin, which is capable of synergizing with PTH, and which may represent a tissue factor which under certain circumstances may exert an influence on bone.