Novel compound heterozygous mutations in DNAH1 cause primary infertility in Han Chinese males with multiple morphological abnormalities of the sperm flagella.

This study aimed to identify genetic causes responsible for multiple morphological abnormalities of the sperm flagella (MMAF) in the Han Chinese population. Three primary infertile males with completely immobile sperm and MMAF were enrolled. Whole-exome sequencing and Sanger sequencing were performed to identify disease-causing genes. Subsequently, morphological and ultrastructural analyses of sperm flagella were investigated. The probable impact of genetic variants on protein function was analyzed by online bioinformatic tools and immunofluorescence assay. Three patients with dynein axonemal heavy chain 1 (DNAH1) gene compound heterozygous variations were identified. DNAH1 c.7435C>T, p.R2479X and c.10757T>C, p.F3586S were identified in the patient from Family 1, c.11726_11727delCT, p.P3909fs and c.12154delC, p.L4052fs were found in the patient from Family 2, and c.10627-3C>G and c.11726_11727delCT, p.P3909fs existed in the patient from Family 3. Four of these variations have not been reported, and all the mutations showed pathogenicity by functional effect predictions. The absence of the center pair and disorganization of the fibrous sheath were present in sperm flagella at the ultrastructural level. Moreover, the expression of DNAH1 was absent in spermatozoa from the participants, validating the pathogenicity of the variants. All three couples have undergone intracytoplasmic sperm injection (ICSI), and two couples of them became pregnant after the treatment. In conclusion, the newly identified DNAH1 mutations can expand the mutational and phenotypic spectrum of MMAF genes and provide a theoretical basis for genetic diagnosis in MMAF patients. It is recommended to conduct genetic screening in male infertility patients with MMAF and provide rational genetic counseling, and ICSI might be an optimal strategy to help with fertilization and conception for patients with DNAH1 mutations.

MiR-3666 serves as a tumor suppressor in ovarian carcinoma by down-regulating AK4 via targeting STAT3.

As a result of metastasis and high recurrence, ovarian carcinoma (OC) is one of the most frequent gynecological carcinomas affecting women up to now. In spite of advances in OC treatments, the molecular mechanisms underlying OC progression are still needed to be deeply understood. MicroRNAs (miRNAs) with aberrant expressions are widely known to regulate target genes so as to mediate diverse biological activities of tumor cells. In the present study, we inspected the expression profile and latent mechanism of miR-3666 in OC. First of all, our research revealed the down-regulated miR-3666 in OC cells. Furthermore, miR-3666 up-regulation could repress cell proliferation and migration as well as induce cell apoptosis in OC. In addition, we unmasked that miR-3666 targeted STAT3 (signal transducer and activator of transcription 3) and further down-regulated STAT3 expression. Moreover, adenylate kinase 4 (AK4) was transcriptionally enhanced by STAT3, and then miR-3666 restrained AK4 expression by mediating STAT3. In the end, rescue experiments depicted that miR-3666 suppressed the development of OC via STAT3-mediated AK4. We uncovered that miR-3666 inhibited the tumorigenesis and even development of OC via suppressing STAT3/AK4 axis, offering a novel biomarker and therapeutic target for OC.

Structural dynamics control the MicroRNA maturation pathway.

MicroRNAs (miRNAs) are crucial gene expression regulators and first-order suspects in the development and progression of many diseases. Comparative analysis of cancer cell expression data highlights many deregulated miRNAs. Low expression of miR-125a was related to poor breast cancer prognosis. Interestingly, a single nucleotide polymorphism (SNP) in miR-125a was located within a minor allele expressed by breast cancer patients. The SNP is not predicted to affect the ground state structure of the primary transcript or precursor, but neither the precursor nor mature product is detected by RT-qPCR. How this SNP modulates the maturation of miR-125a is poorly understood. Here, building upon a model of RNA dynamics derived from nuclear magnetic resonance studies, we developed a quantitative model enabling the visualization and comparison of networks of transient structures. We observed a high correlation between the distances between networks of variants with that of their respective wild types and their relative degrees of maturation to the latter, suggesting an important role of transient structures in miRNA homeostasis. We classified the human miRNAs according to pairwise distances between their networks of transient structures.

Alterations of testis-specific promoter methylation in cell-free seminal deoxyribonucleic acid of idiopathic nonobstructive azoospermic men with different testicular phenotypes.

OBJECTIVE: To explore the feasibility of quantification of testicular DNA methylation from cell-free seminal DNA (cfsDNA), and analyze promoter methylation alterations in men with idiopathic nonobstructive azoospermia (NOA). DESIGN: Comparison between testicular DNA and paired cfsDNA, and among NOA patients with different testicular phenotypes. SETTING: Academic research institute and andrology practice. PATIENT(S): Eighty-eight idiopathic NOA patients with different testicular phenotypes and 24 normozoospermic men. INTERVENTION(S): Testicular biopsies and semen analysis. MAIN OUTCOME MEASURE(S): Five testis-specific methylated promoters were selected. Promoter methylation was quantified using MethyLight in testicular DNA and paired cfsDNA, and the mRNA level was determined by real-time quantitative polymerase chain reaction. RESULT(S): Correlations of methylation of the selected five promoters between testicular DNA and paired cfsDNA were observed; and promoter methylation was negatively related to the messenger RNA level in testis. The cfsDNA methylation of these promoters showed different dynamic changes among the subtypes of NOA and normozoospermia. Among them, CCNA1 and DMRT1 promoter methylation in the hypospermatogenesis group was higher than in other groups and showed diagnostic potential for the patient with hypospermatogenesis. CONCLUSION(S): Cell-free seminal DNA could be a novel, noninvasive biomarker for the detection of testicular epigenetic aberrations. Epigenetic information in cfsDNA related to spermatogenesis may serve to predict successful testicular sperm retrieval in NOA patients.

Tet-mediated covalent labelling of 5-methylcytosine for its genome-wide detection and sequencing.

5-methylcytosine is an epigenetic mark that affects a broad range of biological functions in mammals. The chemically inert methyl group prevents direct labelling for subsequent affinity purification and detection. Therefore, most current approaches for the analysis of 5-methylcytosine still have limitations of being either density-biased, lacking in robustness and consistency, or incapable of analysing 5-methylcytosine specifically. Here we present an approach, TAmC-Seq, which selectively tags 5-methylcytosine with an azide functionality that can be further labelled with a biotin for affinity purification, detection and genome-wide mapping. Using this covalent labelling approach, we demonstrate high sensitivity and specificity for known methylated loci, as well as increased CpG dinucleotide coverage at lower sequencing depth as compared with antibody-based enrichment, providing an improved efficiency in the 5-methylcytosine enrichment and genome-wide profiling.

Fragile X premutation RNA is sufficient to cause primary ovarian insufficiency in mice.

Spontaneous 46,XX primary ovarian insufficiency (POI), also known as 'premature menopause' or 'premature ovarian failure', refers to ovarian dysfunction that results in a range of abnormalities, from infertility to early menopause as the end stage. The most common known genetic cause of POI is the expansion of a CGG repeat to 55-199 copies (premutation) in the 5' untranslated region in the X-linked fragile X mental retardation 1 (FMR1) gene. POI associated with the FMR1 premutation is referred to as fragile X-associated POI (FXPOI). Here, we characterize a mouse model carrying the human FMR1 premutation allele and show that FMR1 premutation RNA can cause a reduction in the number of growing follicles in ovaries and is sufficient to impair female fertility. Alterations in selective serum hormone levels, including FSH, LH and 17ß-estradiol, are seen in this mouse model, which mimics findings in humans. In addition, we also find that LH-induced ovulation-related gene expression is specifically altered. Finally, we show that the FMR1 premutation allele can lead to reduced phosphorylation of Akt and mTOR proteins. These results together suggest that FMR1 premutation RNA could cause the POI associated with FMR1 premutation carriers, and the Akt/mTOR pathway may serve as a therapeutic target for FXPOI.

Bone marrow mesenchymal stem cells can improve the motor function of a Huntington's disease rat model.

OBJECTIVES: The purpose of this study was to investigate the ability of bone marrow mesenchymal stem cells (BMSCs) to survive in the striatum and improve motor function in the quinolinic acid (QA) lesion rat model of Huntington's disease (HD). METHODS: One week following QA lesioning of the striatum, rats were transplanted with BMSCs that had been expanded in culture and labeled with 4'-6-diamidino-2-phenylindole (DAPI) prior to transplantation. RESULTS: BMSCs survived transplantation into the lesioned striatum and differentiated into both neurons. Moreover, transplantation of BMSCs significantly reduced motor dysfunction observed following striatal QA lesioning. Stereological striatal volume analyses performed on Nissl-stained sections revealed that rats transplanted with BMSCs had a greater striatal volume on the lesioned side compared with rats injected with vehicle. Cultured BMSCs expressed trophic factors, including nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF) and ciliary neurotrophic factor (CNTF). In the striatum of BMSC-treated group, the expression levels of these genes were significantly elevated when compared with those of the control group. CONCLUSION: Our data suggested that striatal transplants of BMSCs elicit behavioral and anatomical recovery in the QA lesion model of HD.