ABSTRACT
Spinal muscular atrophy (SMA) is an inherited neuromuscular disorder caused by homozygous absence of the survival motor neuron gene (SMN1). All patients have at least one, usually two to four copies of the related SMN2 gene which, however, produce insufficient levels of functional SMN protein due to the exclusion of exon 7 in the majority of SMN2 transcripts. Here, we show that salbutamol, a beta2-adrenoceptor agonist, determines a rapid and significant increase in SMN2-full length mRNA and SMN protein in SMA fibroblasts, predominantly by promoting exon 7 inclusion in SMN2 transcripts. These data, together with previous clinical findings, provide a strong rationale to investigate further the clinical efficacy of salbutamol in SMA patients.
Subject(s)
Adrenergic beta-Agonists/pharmacology , Albuterol/pharmacology , Cyclic AMP Response Element-Binding Protein/metabolism , Fibroblasts/drug effects , Gene Expression Regulation , Nerve Tissue Proteins/metabolism , RNA, Messenger/metabolism , RNA-Binding Proteins/metabolism , Cyclic AMP Response Element-Binding Protein/genetics , Exons/genetics , Fibroblasts/metabolism , Humans , Muscular Atrophy, Spinal/drug therapy , Muscular Atrophy, Spinal/genetics , Muscular Atrophy, Spinal/metabolism , Nerve Tissue Proteins/genetics , RNA Splicing/drug effects , RNA, Messenger/genetics , RNA-Binding Proteins/genetics , SMN Complex Proteins , Survival of Motor Neuron 1 Protein , Survival of Motor Neuron 2 ProteinABSTRACT
Previous studies showed that SMN2 copy number correlates inversely with the disease severity. Our aim was to evaluate SMN2 copy numbers and the Hammersmith functional motor scale in 87 patients with SMA II in order to establish whether, within SMAII, the number of copies correlates with the severity of functional impairment. Our results showed a relative variability of functional scores, but a significant correlation between the number of SMN2 genes and the level of function.
Subject(s)
Cyclic AMP Response Element-Binding Protein/genetics , Gene Dosage/genetics , Nerve Tissue Proteins/genetics , RNA-Binding Proteins/genetics , Severity of Illness Index , Spinal Muscular Atrophies of Childhood/genetics , Child , Child, Preschool , Female , Humans , Male , SMN Complex Proteins , Spinal Muscular Atrophies of Childhood/physiopathology , Statistics as Topic , Survival of Motor Neuron 2 ProteinABSTRACT
OBJECTIVE: To assess the efficacy of phenylbutyrate (PB) in patients with spinal muscular atrophy in a randomized, double-blind, placebo-controlled trial involving 10 Italian centers. METHODS: One hundred seven children were assigned to receive PB (500 mg/kg/day) or matching placebo on an intermittent regimen (7 days on/7 days off) for 13 weeks. The Hammersmith functional motor scale (primary outcome measure), myometry, and forced vital capacity were assessed at baseline and at weeks 5 and 13. RESULTS: Between January and September 2004, 107 patients aged 30 to 154 months were enrolled. PB was well tolerated, with only one child withdrawing because of adverse events. Mean improvement in functional score was 0.60 in the PB arm and 0.73 in placebo arm (p = 0.70). Changes in the secondary endpoints were also similar in the two study arms. CONCLUSIONS: Phenylbutyrate was not effective at the regimen, schedule, and duration used in this study.
Subject(s)
Muscular Atrophy, Spinal/drug therapy , Phenylbutyrates/therapeutic use , Child , Child, Preschool , Double-Blind Method , Female , Humans , Male , Muscular Atrophy, Spinal/epidemiology , Muscular Atrophy, Spinal/physiopathology , Retrospective StudiesABSTRACT
AIMS: The persistent circulation of hepatitis A virus (HAV) in the Mediterranean area suggests the need for monitoring its presence in the environment. A reverse transcriptase-polymerase chain reaction (RT-PCR) was used to detect the presence of HAV in several consecutive raw sewage and final effluent samples, collected over an 8-month period from an activated sludge treatment plant in southern Italy. METHODS AND RESULTS: Two distinct purification protocols, either based on antigen-capture with monoclonal antibody (AC) or RNA extraction, were compared. The possible influence of the antibody used in the AC phase was evaluated in preliminary experiments on HAV-spiked samples, using two different monoclonal antibodies. Hepatitis A virus RNA was detected in all but one sewage environmental sample examined. The contemporary presence of enteroviruses, reoviruses and phages was observed, while HAV growth in cell culture was hampered. CONCLUSIONS: The RT-PCR technique was confirmed to be a valuable tool for the rapid monitoring of HAV in sewage samples. In addition, this study demonstrated that application of different sample purification methods can result in different levels of sensitivity of the assay and that, in the antigen-capture method, the choice of antibody can have a crucial role. SIGNIFICANCE AND IMPACT OF THE STUDY: This work underlines the need for technical uniformity in environmental studies from different laboratories for a correct and useful comparison of the results.
