Use of the MS-MLPA assay in prenatal diagnosis of Prader-Willi syndrome with mosaic trisomy 15.

OBJECTIVE: We present a prenatal diagnosis strategy of using Methylation-Specific Multiplex Ligation-Dependent Probe Amplification (MS-MLPA) for the detection of maternal uniparental disomy 15/trisomy 15 (UPD(15) mat/T15) mosaicism. CASE REPORT: A 43-year-old woman underwent amniocentesis at 19 weeks of gestation due to a high risk of trisomy 15 (T15) as indicated by non-invasive prenatal testing (NIPT). Cytogenetic analysis revealed a karyotype of 46, XX of cultured amniocytes. Further analysis using copy number variation sequencing (CNV-seq) analysis showed 55 % T15 mosaicism. The second amniocentesis was performed and showed a karyotype of 46, XX and 26 % T15 mosaicism by interphase fluorescence in situ hybridization (FISH). MS-MLPA analysis of uncultured amniocytes showed that the copy number ratio of 15q11-13 ranged from 1.3 to 1.5, and the percentage of methylation was between 70 % and 100 %. MS-MLPA assay of cultured amniocytes showed a copy number ratio of 1 and a methylation percentage of 100 %. Therefore, this fetus was identified to be an UPD(15) mat/T15 mosaicism. The parents decided to terminate the pregnancy. CONCLUSION: MS-MLPA can be used in combination with karyotype and CNV-seq for prenatal diagnosis of NIPT high-risk T15 to avoid missed diagnosis of UPD(15) mat/T15 mosaicism.

Loss of UCP2 causes mitochondrial fragmentation by OMA1-dependent proteolytic processing of OPA1 in podocytes.

Mitochondrial dysfunction plays an important role in the onset and progression of podocyte injury and proteinuria. However, the process by which the change in the podocyte mitochondria occurs is not well understood. Uncoupling protein 2 (UCP2) is a mitochondrial anion carrier protein, which is located in the mitochondrial inner membrane. Here, we reported that mice with podocyte-specific Ucp2 deficiency developed podocytopathy with proteinuria with aging. Furthermore, those mice exhibited increased proteinuria in experimental models evoked by Adriamycin. Our findings suggest that UCP2 mediates mitochondrial dysfunction by regulating mitochondrial dynamic balance. Ucp2-deleted podocytes exhibited increased mitochondrial fission and deficient in ATP production. Mechanistically, opacity protein 1 (OPA1), a key protein in fusion of mitochondrial inner membrane, was regulated by UCP2. Ucp2 deficiency promoted proteolysis of OPA1 by activation OMA1 which belongs to mitochondrial inner membrane zinc metalloprotease. Those finding demonstrate the role of UCP2 in mitochondrial dynamics in podocytes and provide new insights into pathogenesis associated with podocyte injury and proteinuria.

UCP2 deficiency impairs podocyte autophagy in diabetic nephropathy.

OBJECTIVE: Podocytes have been indicated to be a critical factor for the development of diabetic kidney disease. Podocyte loss leads to irreversible glomerular injury and proteinuria in animal models. As terminal differentiated cells, autophagy is crucial for maintaining podocyte homeostasis. Previous studies have shown that Uncoupling proteins 2 (UCP2) regulate fatty acid metabolism, mitochondrial calcium uptake and reactive oxygen species (ROS) production. This study aimed to investigate whether UCP2 promote autophagy in podocyte and further explore the regulation mechanism of UCP2. METHODS: For podocyte-specific UCP2-KO mice, we cross bred UCP2fl/fl mouse strain with the podocin-Cre mice. Diabetic mice were obtained by daily intraperitoneally injections of 40 mg/kg streptozotocin for 3 days. After 6 weeks, mice were scarified, and kidney tissues were analyzed by histological stain, Western blot, Immunofluorescence, and immunohistochemistry. Also, urine samples were collected for protein quantification. For in vitro study, podocytes were primary cultured from UCP2fl/fl mouse or transfected with adeno-associated virus (AAV)-UCP2. RESULTS: Diabetic kidney showed elevated expression of UCP2 and specific ablation of UCP2 in podocyte aggravates diabetes-induced albuminuria and glomerulopathy. UCP2 protects hyperglycemia-induced podocyte injury by promoting autophagy in vivo and in vitro. Rapamycin treatment significantly ameliorates streptozotocin (STZ)-induced podocyte injury in UCP2-/- mice. CONCLUSION: UCP2 expression in podocyte increased under diabetic condition and appeared to be an initial compensatory response. UCP2 deficiency in podocyte impaired autophagy and exacerbates podocyte injury and proteinuria in diabetic nephropathy.

[SNP microarray analysis of retention abortion chorionic villus].

OBJECTIVE: To compare villus cell culture and karyotype analysis with single nucleotide polymorphism (SNP) microarray technology for the detection of chorionic villus chromosome in patients with retention of abortion. METHODS: Forty cases were analyzed with the two methods. RESULTS: Chorionic villus culturing was successful in 29 cases, among which 10 were found to have an abnormal karyotypes. For the SNP microarray analysis, all 40 cases were successful, among which 16 were shown to have an abnormal molecular karyotype. CONCLUSION: SNP microarray technology is highly accurate and specific, which is particularly suitable for the detection of chromosomal deletions or duplications, uniparental disomy, low-percentage mosaicism and other chromosomal abnormalities. It has provided an effective supplement to the conventional chorionic villus culture and karyotype analysis.

[A mutation in TGF beta1 gene encoding the latency-associated peptide in a Chinese patient with Camurati-Engelmann disease].

OBJECTIVE: To identify the mutation in transforming growth factor-beta1 gene (TGF beta1) in a Chinese patient with Camurati-Engelmann disease(CED). METHODS: Denaturing high-performance liquid chromatography (DHPLC) analysis was performed on the whole seven coding exons and exon-intron boundaries, then the mutation was identified by direct sequencing. RESULTS: Mutation screening of TGF beta1 in this patient revealed a heterozygous missense mutation R218H in exon 4. CONCLUSION: The identification of the mutation could provide essential data for subsequent therapy and genetic counseling.

Identification of a novel testis-specific gene mtLR1, which is expressed at specific stages of mouse spermatogenesis.

A novel testis-specific gene termed mtLR1 was identified by digital differential display. Sequence analyses revealed that mtLR1 protein contains an amino terminus leucine-rich repeat domain and shows 33% similarities to PIDD which functions in p53-mediated apoptosis. Northern blot analysis showed that mtLR1 mRNA was specifically expressed in adult mouse testis, and RT-PCR results also showed that mtLR1 was exclusively expressed in adult testis and not in spermatogonial cells. The expression of mtLR1 mRNA was developmentally upregulated in the testes during sexual maturation and was, conversely, downregulated by experimental cryptorchidism in vivo. We also showed that the expression of mtLR1 mRNA was relatively highly sensitive to heat stress in vitro. The green fluorescent protein produced by pEGFP-C3/mtLR1 was only detected in the cytoplasm of spermatogonia cell line GC-1 after 24 h posttransfection. Immunohistochemical analysis revealed that the protein is most abundant in the cytoplasm of spermatocytes and round spermatids within seminiferous tubules of the adult testis. The time-dependent expression pattern of mtLR1 in postnatal mouse testes suggested that mtLR1 gene might be involved in the regulation of spermatogenesis and sperm maturation.