Characterization of CD90/Thy-1 as a crucial molecular signature for myogenic differentiation in human urine-derived cells through single-cell RNA sequencing.

Human urine-derived cells (UDCs) are primary cultured cells originating from the upper urinary tract and are known to be multipotent. We previously developed MYOD1-transduced UDCs (MYOD1-UDCs) as a model recapitulating the pathogenesis of Duchenne muscular dystrophy (DMD) caused by a lack of dystrophin. MYOD1-UDCs also allow evaluation of the efficacy of exon skipping with antisense oligonucleotides. However, despite the introduction of MYOD1, some MYOD1-UDCs failed to form myotubes, possibly because of heterogeneity among UDCs. Here, we carried out single-cell RNA-sequencing analyses and revealed that CD90/Thy-1 was highly expressed in a limited subpopulation of UDCs with high myogenic potency. Furthermore, CD90-positive MYOD1-UDCs, but not CD90-negative cells, could form myotubes expressing high levels of myosin heavy chain and dystrophin. Notably, overexpression of CD90 in CD90-negative MYOD1-UDCs did not enhance myogenic differentiation, whereas CD90 suppression in CD90-positive UDCs led to decreased myotube formation and decreased myosin heavy chain expression. CD90 may thus contribute to the fusion of single-nucleated MYOD1-UDCs into myotubes but is not crucial for promoting the expression of late muscle regulatory factors. Finally, we confirmed that CD90-positive MYOD1-UDCs derived from patients with DMD were a valuable tool for obtaining a highly reproducible and stable evaluation of exon skipping using antisense oligonucleotide.

Ensemble-Learning and Feature Selection Techniques for Enhanced Antisense Oligonucleotide Efficacy Prediction in Exon Skipping.

Antisense oligonucleotide (ASO)-mediated exon skipping has become a valuable tool for investigating gene function and developing gene therapy. Machine-learning-based computational methods, such as eSkip-Finder, have been developed to predict the efficacy of ASOs via exon skipping. However, these methods are computationally demanding, and the accuracy of predictions remains suboptimal. In this study, we propose a new approach to reduce the computational burden and improve the prediction performance by using feature selection within machine-learning algorithms and ensemble-learning techniques. We evaluated our approach using a dataset of experimentally validated exon-skipping events, dividing it into training and testing sets. Our results demonstrate that using a three-way-voting approach with random forest, gradient boosting, and XGBoost can significantly reduce the computation time to under ten seconds while improving prediction performance, as measured by R2 for both 2'-O-methyl nucleotides (2OMe) and phosphorodiamidate morpholino oligomers (PMOs). Additionally, the feature importance ranking derived from our approach is in good agreement with previously published results. Our findings suggest that our approach has the potential to enhance the accuracy and efficiency of predicting ASO efficacy via exon skipping. It could also facilitate the development of novel therapeutic strategies. This study could contribute to the ongoing efforts to improve ASO design and optimize gene therapy approaches.

Quantitative Evaluation of Exon Skipping in Urine-Derived Cells for Duchenne Muscular Dystrophy.

Antisense oligonucleotide (ASO)-based exon skipping therapy is thought to be promising for Duchenne muscular dystrophy (DMD). For the screening or assessing patient eligibility before administering ASO to patients, in vitro testing using myoblasts derived from each DMD patient is considered crucial. We previously reported state-of-the-art technology to obtain patient primary myoblasts from MYOD1-induced urine-derived cells (UDCs) as a model of DMD. We hypothesize that the myoblasts may potentially reflect specific pathological phenotypes, leading to a path for precision medicine in DMD patients. Here, we describe a detailed protocol for both acquiring MYOD1-induced myoblasts from UDCs and evaluating the correction of DMD mRNA and protein levels after exon-skipping in the cells.

Persistent brain damage in reversible cerebral vasoconstriction syndrome on 99mTc-ethyl cysteinate dimer single-photon emission computed tomography: A long-term observational study.

BACKGROUND: Blood-brain barrier (BBB) breakdown is considered a key step in the pathophysiology of reversible cerebral vasoconstriction syndrome (RCVS); however, its temporal course remains unclear. Based on the characteristics and dynamics of 99mTc-ethyl cysteinate dimer (99mTc-ECD) as a tracer, 99mTc-ECD single-photon emission computed tomography (SPECT) can detect not only hypoperfusion but also BBB breakdown and/or brain tissue damage. Therefore, this study aimed to investigate this course using 99mTc-ECD SPECT. METHODS: Between 2011 and 2019, we enrolled seven patients (one male and six female patients) with RCVS without ischemic or hemorrhagic stroke or posterior reversible encephalopathy syndrome. 99mTc-ECD SPECT was performed repeatedly in each patient. SPECT data were statistically analyzed using an easy Z-score imaging system. RESULTS: Thunderclap headache was the initial symptom in all the patients and was most commonly triggered by bathing (three patients). All the patients exhibited vasoconstriction and reduced cerebral uptake of 99mTc-ECD during the acute stage. Follow-up assessment from 3 to 16 months showed that reduced cerebral uptake persisted in all the patients, even after the vasoconstriction had resolved. CONCLUSION: Reduced cerebral uptake of 99mTc-ECD persisted in the late stage of RCVS, even after vasoconstriction and headache subsided. BBB breakdown and/or brain tissue damage may underlie this phenomenon. 99mTc-ECD SPECT is an effective neuroimaging method to detect brain functional abnormalities, reflecting BBB breakdown or tissue damages, throughout the treatment course of RCVS.

eSkip-Finder: a machine learning-based web application and database to identify the optimal sequences of antisense oligonucleotides for exon skipping.

Exon skipping using antisense oligonucleotides (ASOs) has recently proven to be a powerful tool for mRNA splicing modulation. Several exon-skipping ASOs have been approved to treat genetic diseases worldwide. However, a significant challenge is the difficulty in selecting an optimal sequence for exon skipping. The efficacy of ASOs is often unpredictable, because of the numerous factors involved in exon skipping. To address this gap, we have developed a computational method using machine-learning algorithms that factors in many parameters as well as experimental data to design highly effective ASOs for exon skipping. eSkip-Finder (https://eskip-finder.org) is the first web-based resource for helping researchers identify effective exon skipping ASOs. eSkip-Finder features two sections: (i) a predictor of the exon skipping efficacy of novel ASOs and (ii) a database of exon skipping ASOs. The predictor facilitates rapid analysis of a given set of exon/intron sequences and ASO lengths to identify effective ASOs for exon skipping based on a machine learning model trained by experimental data. We confirmed that predictions correlated well with in vitro skipping efficacy of sequences that were not included in the training data. The database enables users to search for ASOs using queries such as gene name, species, and exon number.

Alternating Amaurosis Fugax in Trousseau Syndrome: A Case Report.

Amaurosis fugax (AmF) is defined as transient monocular visual loss secondary to retinal ischemia. In most patients presenting with AmF, the attack of visual loss occurs in the same eye. A 64-year-old woman experienced transient visual loss in her right eye. Three days after that, an attack happened on the left side. In total, she had 5 episodes of AmF in 2 months. AmF occurred on both sides at different times, and so may be referred to as "Alternating AmF". Diffusion-weighted magnetic resonance imaging showed high-intensity lesions in various parts of brain, and laboratory examination revealed elevated D-dimer and ovarian tumor marker. We suspected Trousseau syndrome and found a giant ovary tumor. After removal of the tumor, no recurrence was observed. When a patient with alternating AmF is encountered, screening for malignancy is essential.

Clinical results of trochanteric fractures treated with the TARGON® proximal femur intramedullary nailing fixation system.

The aim of this study was to investigate the outcome of 352 (71 males) patients with trochanteric fractures that were treated with the TARGON® PF nail. The mean age was 83 years. According to the Jensen classification, there were 35 cases in type 1,94 cases in type 2,75 in type 3,63 in type 4 and 85 in type 5. Postoperative all patients were allowed to fully weight bear from the first postoperative day. Clinical and radiological data were collected at regular time intervals. The average waiting time to surgical reconstruction for the 352 cases was 3.5 days (1-7). The mean length of hospital stay was 14 days (5-22). The operative times ranged from 11 to 125 minutes with an average time of 32 minutes. Fifty percent of the patients regained their mobility to their pre-injury level at the final follow up. Out of 310 patients (88%) who were available for radiographie assessment, all fractures united except one case. 300 (85%) of the lag screws were placed in the inferior area in the anteroposterior view and in the central area in the lateral view (IM), which is regarded as the optimal position. The lag screws back-slided between 0 and 19 mms with an average of 6 mm. Sliding distance of the lag screw for over 10 mm was seen in 42 cases (13%). Varus collapse of the femoral head-and-neck greater than 10° was observed in 6 cases. Postoperative complications developed in 6 cases (1.7%), including wound infection in two cases, and secondary fracture at the subtrochanteric region, nonunion, back-out of the guiding sleeve and medial perforation of the lag screw, each in one case. The presented case series indicates that the TARGON® PF system is an effective and safe internal fixation device for trochanteric proximal femoral fractures. Further, prospective comparative evidence regarding the use of this system is needed to analyse and validate the presented clinical impression of our centre.