The myelination-associated G protein-coupled receptor 37 is regulated by Zfp488, Nkx2.2, and Sox10 during oligodendrocyte differentiation.

Oligodendrocyte differentiation and myelination in the central nervous system are controlled and coordinated by a complex gene regulatory network that contains several transcription factors, including Zfp488 and Nkx2.2. Despite the proven role in oligodendrocyte differentiation little is known about the exact mode of Zfp488 and Nkx2.2 action, including their target genes. Here, we used overexpression of Zfp488 and Nkx2.2 in differentiating CG4 cells to identify aspects of the oligodendroglial expression profile that depend on these transcription factors. Although both transcription factors are primarily described as repressors, the detected changes argue for an additional function as activators. Among the genes activated by both Zfp488 and Nkx2.2 was the G protein-coupled receptor Gpr37 that is important during myelination. In agreement with a positive effect on Gpr37 expression, downregulation of the G protein-coupled receptor was observed in Zfp488- and in Nkx2.2-deficient oligodendrocytes in the mouse. We also identified several potential regulatory regions of the Gpr37 gene. Although Zfp488 and Nkx2.2 both bind to one of the regulatory regions downstream of the Gpr37 gene in vivo, none of the regulatory regions was activated by either transcription factor alone. Increased activation by Zfp488 or Nkx2.2 was only observed in the presence of Sox10, a transcription factor continuously present in oligodendroglial cells. Our results argue that both Zfp488 and Nkx2.2 also act as transcriptional activators during oligodendrocyte differentiation and cooperate with Sox10 to allow the expression of Gpr37 as a modulator of the myelination process.

Human fetal cerebellar cell atlas informs medulloblastoma origin and oncogenesis.

Medulloblastoma (MB) is the most common malignant childhood brain tumour1,2, yet the origin of the most aggressive subgroup-3 form remains elusive, impeding development of effective targeted treatments. Previous analyses of mouse cerebella3-5 have not fully defined the compositional heterogeneity of MBs. Here we undertook single-cell profiling of freshly isolated human fetal cerebella to establish a reference map delineating hierarchical cellular states in MBs. We identified a unique transitional cerebellar progenitor connecting neural stem cells to neuronal lineages in developing fetal cerebella. Intersectional analysis revealed that the transitional progenitors were enriched in aggressive MB subgroups, including group 3 and metastatic tumours. Single-cell multi-omics revealed underlying regulatory networks in the transitional progenitor populations, including transcriptional determinants HNRNPH1 and SOX11, which are correlated with clinical prognosis in group 3 MBs. Genomic and Hi-C profiling identified de novo long-range chromatin loops juxtaposing HNRNPH1/SOX11-targeted super-enhancers to cis-regulatory elements of MYC, an oncogenic driver for group 3 MBs. Targeting the transitional progenitor regulators inhibited MYC expression and MYC-driven group 3 MB growth. Our integrated single-cell atlases of human fetal cerebella and MBs show potential cell populations predisposed to transformation and regulatory circuitries underlying tumour cell states and oncogenesis, highlighting hitherto unrecognized transitional progenitor intermediates predictive of disease prognosis and potential therapeutic vulnerabilities.

Mapping Local Climate Zones in the Urban Environment: The Optimal Combination of Data Source and Classifier.

The novel concept of local climate zones (LCZs) provides a consistent classification framework for studies of the urban thermal environment. However, the development of urban climate science is severely hampered by the lack of high-resolution data to map LCZs. Using Gaofen-6 and Sentinel-1/2 as data sources, this study designed four schemes using convolutional neural network (CNN) and random forest (RF) classifiers, respectively, to demonstrate the potential of high-resolution images in LCZ mapping and evaluate the optimal combination of different data sources and classifiers. The results showed that the combination of GF-6 and CNN (S3) was considered the best LCZ classification scheme for urban areas, with OA and kappa coefficients of 85.9% and 0.842, respectively. The accuracy of urban building categories is above 80%, and the F1 score for each category is the highest, except for LCZ1 and LCZ5, where there is a small amount of confusion. The Sentinel-1/2-based RF classifier (S2) was second only to S3 and superior to the combination of GF-6 and random forest (S1), with OA and kappa coefficients of 64.4% and 0.612, respectively. The Sentinel-1/2 and CNN (S4) combination has the worst classification result, with an OA of only 39.9%. The LCZ classification map based on S3 shows that the urban building categories in Xi'an are mainly distributed within the second ring, while heavy industrial buildings have started to appear in the third ring. The urban periphery is mainly vegetated and bare land. In conclusion, CNN has the best application effect in the LCZ mapping task of high-resolution remote sensing images. In contrast, the random forest algorithm has better robustness in the band-abundant Sentinel data.

[Aerosol Optical Characteristics with Ground-based Measurements via Sun Photometer and Its Relationship with PM Particle Concentration in Chang'an].

The simultaneous quantitative investigation of aerosol ground observation data and particle concentration data is important for a better understanding of the vertical distribution characteristics of air pollution and formulating reasonable air pollution control measures in Chang'an, Xi'an. CE-318 measurements from October 2018 to April 2021 were systematically analyzed to reveal the seasonal and yearly variations in atmospheric aerosols in Chang'an. Then, the relationship between AOD and particle concentration in different seasons and different pollution degrees was explored. The obtained results were as follows:① the seasonal variation in AOD in Chang'an was determined, whereby autumn (1.02)>winter (1.00)>summer (0.63)>spring (0.47). Distinct monthly and inter-annual differences in AOD were observed, showing that the annual average of AOD in 2019 was higher than that in 2020. ② Obvious seasonal and monthly differences in aerosol main control modes were observed; the dominant mode of aerosols gradually changed from coarse mode to fine mode from spring to winter. The seasonal variation in the main control mode of aerosols in 2019 was similar to that in the whole observation period. The seasonal aerosol Angstrom wavelength index (Angstrom) was evenly distributed in 2020, and aerosol particles existed in coarse mode form. Generally speaking, the aerosol type in Chang'an was mostly mixed aerosol throughout the whole observation period. ③ Significant seasonal variations in the relationship between AOD and Angstrom was shown, in which the air pollution in spring was dominated by coarse mode aerosol particles. The local pollution in summer was caused by coarse and fine mode aerosol particles, and the fine mode particles were dominant when the pollution was obvious. The characteristic distribution of Angstrom in autumn and winter was similar; in case of local pollution, the coarse mode aerosol particles were dominant, and in case of obvious pollution, the fine mode aerosol particles were dominant. ④ The monthly concentration variation trend of PM2.5 and PM10 in Chang'an consistent with the maximum and minimum values appeared in January and summer, respectively. Seasonal variation in the concentration of PM2.5 and PM10 was apparent, with the highest values in winter. ⑤ A positive correlation between AOD and particulate matter concentration in different seasons and pollution levels was obtained during the observation periods, but the correlation coefficient differed. The specific characteristics were as follows:the correlation between AOD and PM2.5 concentration was greater than that with PM10 concentration; the correlation between AOD and particle concentration in autumn and winter was greater than that in spring and summer; and the correlation between AOD and particulate matter concentration was greater in polluted weather. Particle concentration was the most important determinant of AOD change, followed by relative humidity, which was the meteorological factor with the highest interpretation rate of AOD change in Chang'an. This indicates that a higher correlation between AOD and particle concentration would benefit from a reasonable humidity correction of AOD.

DMD/BMD prenatal diagnosis and treatment expectation in a single centre in China for 15 years.

OBJECTIVE: DMD/BMD prenatal diagnosis for 931 foetuses. BACKGROUND: DMD is the most common fatal X-linked recessive muscular disease. There is no effective clinical treatment method at present. Accurate gene diagnosis and prenatal diagnosis technology are important ways for early detection, early prevention and early treatment. METHODS: A total of 931 prenatal diagnoses were performed for pregnant women with a definite family history of DMD or a history of DMD childbirth between 2005 and 2019. This report may be considered the largest DMD prenatal diagnosis report in a single centre worldwide. Multiple ligation-dependent probe amplification (MLPA) and next-generation sequencing were used in combination. Techniques and short tandem repeat (STR) linkage analysis were used to determine the location of the DMD gene mutation in the pregnant woman and then to detect the DMD gene in the foetuses. RESULTS: There were 872 families in our study. Among all 931 foetuses, 20.73% (193/931) were males expected to develop DMD and 16.33% (152/931) were female carriers. In addition, gonadal mosaicism was observed in 5 mothers, and gene recombination was identified in three foetuses. The results of the prenatal diagnosis were consistent with the results of the CPK analysis, and the results of the prenatal diagnosis were 100% accurate. CONCLUSIONS: MLPA and Sanger sequencing, when combined with STR linkage analyses, can provide an accurate and rapid prenatal diagnosis. Due to the high de novo rate, prenatal diagnosis and genetic counselling should be given great attention.

Genetic analysis of 1051 Chinese families with Duchenne/Becker Muscular Dystrophy.

BACKGROUND: Duchenne Muscular Dystrophy (DMD) is the most common muscle disease in children, and there are no effective therapies for DMD or Becker Muscular Dystrophy (BMD). Currently, targeted gene therapy treatments have emerged. As a result, genetic diagnosis is the basis of treatment. In addition, genetic and prenatal diagnosis significantly reduces their incidence rates. This study combines the application of multiplex ligation-dependent probe amplification technology (MLPA) and "next-generation" sequencing technology (NGS) as the most economical and efficient method of diagnosis. Therefore, in the diagnosis of DMD/BMD, patients' MLPA data are first used to detect DMD gene deletions or duplications, and NGS and Sanger sequencing are then applied to exclude MLPA-negative samples. Meanwhile, polymerase chain reaction (PCR) is used to detect single exon deletions to exclude false-positives in MLPA caused by point mutations. METHODS: In this study, we recruited 1051 proband families of DMD from 2016 to 2018 and had access to information that could identify individual participants during or after data collection. Patients who were diagnosed with DMD were first tested by MLPA. MLPA results with single exon deletions were validated with PCR amplification and Sanger sequencing. The negative results of MLPA were further analysed with NGS and validated by Sanger sequencing. For novel missense mutations, phenotype-genotype correlations were analysed using PolyPhen2 and mutation taster. All methods were performed in accordance with the relevant guidelines and regulations. RESULTS: DMD mutations were identified in 1029 families (97.91%, 1029/1051). Large deletions, duplications, and small mutations accounted for 70.41% (740/1051), 8.28% (87/1051), and 19.12% (201/1051) of all cases, respectively. There were 205 small mutation types, 53 of which were novel. The rate of de novo mutations was 39.45% (187/474) and was higher in large duplications (49.53%, 157/317). Among 68 asymptomatic patients (< 3 years old) with unexplained persistent hyperCKaemia upon conventional physical examination, 63 were diagnosed as DMD/BMD according to genetic diagnosis. CONCLUSION: Our results expand the spectrum of DMD mutations, which could contribute to the treatment of DMD/BMD and provide an effective diagnosis method. Thus, the combination of MLPA, NGS and Sanger sequencing is of great significance for family analysis, gene diagnosis and gene therapy.

[Genetic testing of chorionic villi from abortuses during early pregnancy].

OBJECTIVE: To explore the prevalence and characteristics of chromosomal abnormalities in abortuses during early pregnancy with single nucleotide polymorphism microarray (SNP-array). METHODS: For 520 abortuses, copy number variations (CNVs) in chorionic villi were analyzed with SNP-array. RESULTS: In 510 (98.1%) of the samples, the analysis was successful. Among these, 57.6% (294/510) of the samples were found to harbor clinically significant chromosomal abnormalities. 38.8% of the samples (198/510) had a normal result. 2.4% (12/510) of the samples harbored benign CNVs, and 1.2% (6/510) harbored variants of uncertain significance (VOUS). Aneuploidies, polyploidies, pathogenic CNVs and uniparental disomies (UPD) had accounted for 75.2% (221/294), 13.9% (41/294), 8.2% (24/294), and 2.7% (8/294) of the samples, respectively. 45,XO was the most common finding, which was followed by trisomy 16 and trisomy 22. 69,XXY was the most common polyploidy. CONCLUSION: Chromosomal abnormalities are the main cause for early miscarriage, among which aneuploidies are most common. The prevalence of aneuploidies is significantly increased among women over 35. SNP-array analysis has the advantage of high success rate, high resolution and great accuracy, but the clinical significance of microdeletions/microduplications found by SNP-array can be difficult for interpretation.

Exploring the cause of early miscarriage with SNP-array analysis and karyotyping.

OBJECTIVE: The aim of this study is to explore the cause of miscarriage, providing risk assessment to guide the next pregnancy. METHODS: Four hundred eighty-four products-of-conception (POC) samples were analyzed by single nucleotide polymorphism (SNP) array, and peripheral blood samples of couples were collected for karyotyping or fluorescence in situ hybridization (FISH) analysis. RESULTS: Four hundred sixty-eight of the 484 (96.7%) fresh POC samples were successfully analyzed using SNP-array. The rate of clinically significant chromosomal abnormalities were 58.3% (274/468), in which rates of aneuploidy, polyploidy, partial aneuploidy, uniparental isodisomy (isoUPD), and pathogenic microdeletion/microduplication were 43.4% (203/468), 8.8% (41/468), 3.6% (17/468), 1.9% (9/48), and 0.9% (4/468), respectively. The percentage of embryonic chromosomal abnormalities significantly increased with maternal age of patients older than 35 years old. Among 468 couples, 12 major chromosomal rearrangements were detected by G-banding, including nine reciprocal translocations, two Robertsonian translocations, and one superfemale. CONCLUSIONS: Chromosome abnormality is the main causes of early miscarriage, and aneuploidies are the most common type of chromosomal abnormalities. Application of SNP array and karyotyping in early miscarriage can provide more genetic information about miscarriage, providing risk assessment to guide the next pregnancy.

Generation of ZZUi008-A, a transgene-free, induced pluripotent stem cell line derived from chorionic villi cells of a fetus with Duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) is a common X-linked recessive disorder for which there is no present cure. In this paper, we reported the generation of ZZUi008-A, an induced pluripotent stem cell(iPSC) line derived from chorionic villus(CV) cells of a fetus with a deletion mutation in exon 33 of the dystrophin gene (DMD). The cell line was generated using feeder-free and virus-free conditions, and the established cell line retains the original DMD mutation, a normal karyotype, expresses pluripotency markers, able to differentiate into three lineages. This ZZUi008-A cell line could provide a promising tool to study this complex disease.