SummaryTuberous sclerosis complex (TSC) is a disease featuring devastating and therapeutically challenging neurological abnormalities. However, there is a lack of specific neural progenitor cell models for TSC. Here, the pathology of TSC was studied using primitive neural stem cells (pNSCs) from a patient presenting a c.1444-2A>C mutation in TSC2. We found that TSC2 pNSCs had higher proliferative activity and increased PAX6 expression compared with those of control pNSCs. Neurons differentiated from TSC2 pNSCs showed enlargement of the soma, perturbed neurite outgrowth, and abnormal connections among cells. TSC2 astrocytes had increased saturation density and higher proliferative activity. Moreover, the activity of the mTOR pathway was enhanced in pNSCs and induced in neurons and astrocytes. Thus, our results suggested that TSC2 heterozygosity caused neurological malformations in pNSCs, indicating that its heterozygosity might be sufficient for the development of neurological abnormalities in patients.

Stem cell therapy is a promising approach for treating Duchenne muscular dystrophy (DMD); however, its application is hindered by poor cell engraftment. There have been no reports to date describing the efficient generation of myogenic progenitors from adipose-derived stem cells (ADSCs) that can contribute to muscle regeneration. In this study, we examined the in vivo myogenic potential of progenitors differentiated from ADSCs using forskolin, basic fibroblast growth factor, the glycogen synthase kinase 3β inhibitor 6-bromoindirubin-3'-oxime as well as the supernatant of ADSC cultures. The results indicate that a proliferative population of myogenic progenitors can be derived from ADSCs that have characteristics similar to muscle satellite cells and are capable of terminal differentiation into multinucleated myotubes. When transplanted into DMD model mdx mice either by intramuscular injection or systemic delivery, progenitors were successfully engrafted in skeletal muscle for up to 12 weeks, and generated new muscle fibers, restored dystrophin expression and contributed to the satellite cell compartment. These findings highlight the potential application of myogenic progenitors derived from ADSCs to the treatment of muscular dystrophy.

Here, we investigated correlations between serum creatinine (SCRN) levels and clinical phenotypes of dystrophinopathy in young patients. Sixty-eight patients with dystrophinopathy at the Neuromuscular Clinic, The First Affiliated Hospital, Sun Yat-sen University, were selected for this study. The diagnosis of dystrophinopathy was based on clinical manifestation, biochemical changes, and molecular analysis. Some patients underwent muscle biopsies; SCRN levels were tested when patients were ≤3 years old, and reading frame changes were analyzed. Each patient was followed up, and motor function and clinical phenotype were assessed when the same patients were ≥4 years old. Our findings indicated that in young patients, lower SCRN levels were associated with increased disease severity (p < 0.01) and that SCRN levels were the highest in patients exhibiting mild Becker muscular dystrophy (BMD) (p < 0.001) and the lowest in patients with Duchenne muscular dystrophy (DMD) (p < 0.01) and were significantly higher in patients carrying in-frame mutations than in patients carrying out-of-frame mutations (p < 0.001). SCRN level cutoff values for identifying mild BMD [18 µmol/L; area under the curve (AUC): 0.947; p < 0.001] and DMD (17 µmol/L; AUC: 0.837; p < 0.001) were established. These results suggest that SCRN might be a valuable biomarker for distinguishing DMD from BMD in patients aged ≤3 years and could assist in the selection of appropriate treatment strategies.

Background: Duchenne muscular dystrophy (DMD) is a fatal, X-linked recessive muscle disorder characterized by heterogeneous progression and severity. We aimed to study the effects of single nucleotide polymorphisms (SNPs) in SPP1 and LTBP4 on DMD progression in Chinese patients. Methods: We genotyped LTBP4 haplotypes and the SPP1 promoter SNPs rs28357094, rs11730582, and rs17524488 in 326 patients registered in the neuromuscular database of The First Affiliated Hospital of Sun Yat-sen University. Kaplan-Meier curves and log-rank tests were used to estimate and compare median age at loss of ambulation, while Cox proportional hazard regression models were used as to analyze the effects of glucocorticoids treatments, DMD genotype, and SPP1 / LTBP4 SNPs on loss of ambulation. Results: The CC/CT genotype at rs11730582 was associated with a 1.33-year delay in ambulation loss ( p = 0.006), with hazard ratio 0.63 ( p = 0.008), in patients with truncated DMD genotype and undergoing steroid treatment. On the other hand, rs17524488 in SPP1 and the IAAM/IAAM haplotype in LTBP4 were not associated with time to ambulation loss. Conclusions: SPP1 rs11730582 is a genetic modifier of the long-term effects of steroid treatment in Chinese DMD patients. Thus, any future clinical study in DMD should adjust for glucocorticoids use, DMD genotype, and SPP1 polymorphisms.