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1.  Longitudinal MRI quantification of muscle degeneration in Duchenne muscular dystrophy 
The aim of this study was to evaluate the usefulness of magnetic resonance imaging (MRI) in detecting the progression of Duchenne muscular dystrophy (DMD) by quantification of fat infiltration (FI) and muscle volume index (MVI, a residual‐to‐total muscle volume ratio).
Twenty‐six patients (baseline age: 5–12 years) with genetically proven DMD were longitudinally analyzed with lower limb 3T MRI, force measurements, and functional tests (Gowers, 10‐m time, North Star Ambulatory Assessment, 6‐min walking test). Five age‐matched controls were also examined, with a total of 85 MRI studies. Semiquantitative (scores) and quantitative MRI (qMRI) analyses (signal intensity ratio – SIR, lower limb MVI, and individual muscle MVI) were carried out. Permutation and regression analyses according to both age and functional test‐outcomes were calculated. Age‐related quantitative reference curves of SIRs and MVIs were generated.
FI was present on glutei and adductor magnus in all patients since the age of 5, with a proximal‐to‐distal progression and selective sparing of sartorius and gracilis. Patients' qMRI measures were significantly different from controls' and among age classes. qMRI were more sensitive than force measurements and functional tests in assessing disease progression, allowing quantification also after loss of ambulation. Age‐related curves with percentile values were calculated for SIRs and MVIs, to provide a reference background for future experimental therapy trials. SIRs and MVIs significantly correlated with all clinical measures, and could reliably predict functional outcomes and loss of ambulation.
qMRI‐based indexes are sensitive measures that can track the progression of DMD and represent a valuable tool for follow‐up and clinical studies.
PMCID: PMC4999593  PMID: 27606343
2.  Intra‐arterial transplantation of HLA‐matched donor mesoangioblasts in Duchenne muscular dystrophy 
EMBO Molecular Medicine  2015;7(12):1513-1528.
Intra‐arterial transplantation of mesoangioblasts proved safe and partially efficacious in preclinical models of muscular dystrophy. We now report the first‐in‐human, exploratory, non‐randomized open‐label phase I–IIa clinical trial of intra‐arterial HLA‐matched donor cell transplantation in 5 Duchenne patients. We administered escalating doses of donor‐derived mesoangioblasts in limb arteries under immunosuppressive therapy (tacrolimus). Four consecutive infusions were performed at 2‐month intervals, preceded and followed by clinical, laboratory, and muscular MRI analyses. Two months after the last infusion, a muscle biopsy was performed. Safety was the primary endpoint. The study was relatively safe: One patient developed a thalamic stroke with no clinical consequences and whose correlation with mesoangioblast infusion remained unclear. MRI documented the progression of the disease in 4/5 patients. Functional measures were transiently stabilized in 2/3 ambulant patients, but no functional improvements were observed. Low level of donor DNA was detected in muscle biopsies of 4/5 patients and donor‐derived dystrophin in 1. Intra‐arterial transplantation of donor mesoangioblasts in human proved to be feasible and relatively safe. Future implementation of the protocol, together with a younger age of patients, will be needed to approach efficacy.
PMCID: PMC4693504  PMID: 26543057
cell therapy; Duchenne; dystrophin; mesoangioblast; MRI; Genetics, Gene Therapy & Genetic Disease; Musculoskeletal System
3.  6 Minute Walk Test in Duchenne MD Patients with Different Mutations: 12 Month Changes 
PLoS ONE  2014;9(1):e83400.
In the last few years some of the therapeutical approaches for Duchenne muscular dystrophy (DMD) are specifically targeting distinct groups of mutations, such as deletions eligible for skipping of individual exons. The aim of this observational study was to establish whether patients with distinct groups of mutations have different profiles of changes on the 6 minute walk test (6MWT) over a 12 month period.
The 6MWT was performed in 191 ambulant DMD boys at baseline and 12 months later. The results were analysed using a test for heterogeneity in order to establish possible differences among different types of mutations (deletions, duplications, point mutations) and among subgroups of deletions eligible to skip individual exons.
At baseline the 6MWD ranged between 180 and 560,80 metres (mean 378,06, SD 74,13). The 12 month changes ranged between −325 and 175 (mean −10.8 meters, SD 69.2). Although boys with duplications had better results than those with the other types of mutations, the difference was not significant.
Similarly, boys eligible for skipping of the exon 44 had better baseline results and less drastic changes than those eligible for skipping exon 45 or 53, but the difference was not significant.
even if there are some differences among subgroups, the mean 12 month changes in each subgroup were all within a narrow Range: from the mean of the whole DMD cohort. This information will be of help at the time of designing clinical trials with small numbers of eligible patients.
PMCID: PMC3885414  PMID: 24421885
5.  Importance of SPP1 genotype as a covariate in clinical trials in Duchenne muscular dystrophy 
Neurology  2012;79(2):159-162.
To test the effect of the single nucleotide polymorphism −66 T>G (rs28357094) in the osteopontin gene (SPP1) on functional measures over 12 months in Duchenne muscular dystrophy (DMD).
This study was conducted on a cohort of ambulatory patients with DMD from a network of Italian neuromuscular centers, evaluated longitudinally with the North Star Ambulatory Assessment (NSAA) and the 6-Minute Walk Test (6MWT) at study entry and after 12 months. Genotype at rs28357094 was determined after completion of the clinical evaluations. Patients were stratified in 2 groups according to a dominant model (TT homozygotes vs TG heterozygotes and GG homozygotes) and clinical data were retrospectively compared between groups.
Eighty patients were selected (age 4.1–19.3 years; mean 8.3 ± 2.7 SD). There were no differences in age or steroid treatment between the 2 subgroups. Paired t test showed a significant difference in both NSAA (p = 0.013) and 6MWT (p = 0.03) between baseline and follow-up after 12 months in patients with DMD carrying the G allele. The difference was not significant in the T subgroup. The analysis of covariance using age and baseline values as covariate and SPP1 genotype as fixed effect showed that these parameters are significantly correlated with the 12-month values.
These data provide evidence of the role of SPP1 genotype as a disease modifier in DMD and support its relevance in the selection of homogeneous groups of patients for future clinical trials.
PMCID: PMC3390537  PMID: 22744661
7.  Evolutionary principles of modular gene regulation in yeasts 
eLife  2013;2:e00603.
Divergence in gene regulation can play a major role in evolution. Here, we used a phylogenetic framework to measure mRNA profiles in 15 yeast species from the phylum Ascomycota and reconstruct the evolution of their modular regulatory programs along a time course of growth on glucose over 300 million years. We found that modules have diverged proportionally to phylogenetic distance, with prominent changes in gene regulation accompanying changes in lifestyle and ploidy, especially in carbon metabolism. Paralogs have significantly contributed to regulatory divergence, typically within a very short window from their duplication. Paralogs from a whole genome duplication (WGD) event have a uniquely substantial contribution that extends over a longer span. Similar patterns occur when considering the evolution of the heat shock regulatory program measured in eight of the species, suggesting that these are general evolutionary principles.
eLife digest
The incredible diversity of living creatures belies the fact that their genes are quite similar. In the 1970s Mary-Claire King and Allan Wilson proposed that a process called gene regulation—which determines when, where and how genes are expressed as proteins—is responsible for this diversity. Four decades later, the central role of gene regulation in evolution has been confirmed in a wide range of species including bacteria, fungi, flies and mammals, although the details remain poorly understood. In recent years it has been suggested that the duplication of genes—and sometimes the duplication of whole genomes—has had a crucial influence on the part played by gene regulation in the evolution of many different species.
Ascomycota fungi are uniquely suited to the study of genetics and evolution because of their diversity—they include C. albicans, a fungus that is found in the human mouth and gut, and various species of yeast—and because many of their genomes have already been sequenced. Moreover, their genomes are relatively small, which simplifies the task of working out how it has changed over the course of evolution. It is also known that species in this branch of the tree of life diverged before and after an event in which a whole genome was duplicated.
Ascomycota fungi use glucose as a source of carbon in different ways during aerobic growth. Most, including C. albicans, are respiratory and rely on oxidative phosphorylation processes to produce energy. However, a small number—including S. cerevisiae and S. pombe, two types of yeast that are widely used as model organisms—prefer to ferment glucose, even when oxygen is available. Species that favor the latter respiro-fermentative lifestyle have evolved independently at least twice: once after the whole genome duplication event that lead to S. cerevisiae, and once when S. pombe and the other fission yeasts evolved.
Thompson et al. have measured mRNA profiles in 15 different species of yeast and reconstructed how the regulation of groups of genes (modules) have evolved over a period of more than 300 million years. They found that modules have diverged proportionally to evolutionary time, with prominent changes in gene regulation being associated with changes in lifestyle (especially changes in carbon metabolism) and a whole genome duplication event.
Gene duplication events result in gene paralogs—identical genes at different places in the genome—and these have made significant contributions to the evolution of different forms of gene regulation, especially just after the duplication event. Moreover, the paralogs produced in whole genome duplication events have resulted in bigger changes over longer periods of time. Similar patterns were observed in the regulation of the genes involved in the response to heat shock in eight of the species, which suggests that these are general evolutionary principles.
The changes in gene expression associated with the respiro-fermentative lifestyle may also have implications for our understanding of cancer: healthy cells rely on oxidative phosphorylation to produce energy whereas, similar to yeast cells, most cancerous cells rely on respiro-fermentation. Furthermore, yeast cells and cancer cells both support their rapid growth and proliferation by using glucose for biosynthesis to support cell division, although this process is not fully understood. Normal cells, on the other hand, use glucose primarily for energy and tend not to divide rapidly.
Thompson et al. found that the genes encoding enzymes in two biosynthetic pathways—one that produces the nucleotides necessary for DNA replication, and one that synthesizes glycine—are induced in respiro-fermentative yeasts but repressed in respiratory yeast cells. The fact that similar changes are observed in the same two pathways when normal cells become cancer cells suggests that these pathways have an important role in the development of cancer. The framework developed by Thompson et al. could also be used to explore the evolution of gene regulation in other species and biological processes.
PMCID: PMC3687341  PMID: 23795289
regulatory evolution; duplication; divergence; carbon lifestyle; module; gene expression; S. cerevisiae; S. pombe
8.  24 Month Longitudinal Data in Ambulant Boys with Duchenne Muscular Dystrophy 
PLoS ONE  2013;8(1):e52512.
The aim of the study was i) to assess the spectrum of changes over 24 months in ambulant boys affected by Duchenne muscular dystrophy, ii) to establish the difference between the first and the second year results and iii) to identify possible early markers of loss of ambulation.
One hundred and thirteen patients (age range 4.1–17, mean 8.2) fulfilled the inclusion criteria, 67 of the 113 were on daily and 40 on intermittent steroids, while 6 were not on steroids. All were assessed using the 6 Minute Walk Test (6MWT), the North Star Ambulatory Assessment (NSAA) and timed test.
On the 6MWT there was an average overall decline of −22.7 (SD 81.0) in the first year and of −64.7 (SD 123.1) in the second year. On the NSAA the average overall decline was of −1.86 (SD 4.21) in the first year and of −2.98 (SD 5.19) in the second year. Fourteen children lost ambulation, one in the first year and the other 13 in the second year of the study. A distance of at least 330 meters on the 6MWT, or a NSAA score of 18 at baseline reduced significantly the risk of losing ambulation within 2 years.
These results can be of help at the time of using inclusion criteria for a study in ambulant patients in order to minimize the risk of patients who may lose ambulation within the time of the trial.
PMCID: PMC3543414  PMID: 23326337
9.  Quantitative muscle strength assessment in duchenne muscular dystrophy: longitudinal study and correlation with functional measures 
BMC Neurology  2012;12:91.
The aim of this study was to perform a longitudinal assessment using Quantitative Muscle Testing (QMT) in a cohort of ambulant boys affected by Duchenne muscular dystrophy (DMD) and to correlate the results of QMT with functional measures. This study is to date the most thorough long-term evaluation of QMT in a cohort of DMD patients correlated with other measures, such as the North Star Ambulatory Assessment (NSAA) or thee 6-min walk test (6MWT).
This is a single centre, prospective, non-randomised, study assessing QMT using the Kin Com® 125 machine in a study cohort of 28 ambulant DMD boys, aged 5 to 12 years. This cohort was assessed longitudinally over a 12 months period of time with 3 monthly assessments for QMT and with assessment of functional abilities, using the NSAA and the 6MWT at baseline and at 12 months only. QMT was also used in a control group of 13 healthy age-matched boys examined at baseline and at 12 months.
There was an increase in QMT over 12 months in boys below the age of 7.5 years while in boys above the age of 7.5 years, QMT showed a significant decrease. All the average one-year changes were significantly different than those experienced by healthy controls. We also found a good correlation between quantitative tests and the other measures that was more obvious in the stronger children.
Our longitudinal data using QMT in a cohort of DMD patients suggest that this could be used as an additional tool to monitor changes, providing additional information on segmental strength.
PMCID: PMC3482602  PMID: 22974002

Results 1-9 (9)