Altered microRNA expression profiles of human spermatozoa in normal fertile men of different ages / 亚洲男科学杂志(英文版)

MicroRNAs (miRNAs) are mediators of the aging process. The purpose of this work was to analyze the miRNA expression profiles of spermatozoa from men of different ages with normal fertility. Twenty-seven donors were divided into three groups by age (Group A, n = 8, age: 20-30 years; Group B, n = 10, age: 31-40 years; and Group C, n = 9, age: 41-55 years) for high-throughput sequencing analysis. Samples from 65 individuals (22, 22, and 21 in Groups A, B, and C, respectively) were used for validation by quantitative real-time polymerase chain reaction (qRT-PCR). A total of 2160 miRNAs were detected: 1223 were known, 937 were newly discovered and unnamed, of which 191 were expressed in all donors. A total of 7, 5, and 17 differentially expressed microRNAs (DEMs) were found in Group A vs B, Group B vs C, and Group A vs C comparisons, respectively. Twenty-two miRNAs were statistically correlated with age. Twelve miRNAs were identified as age-associated miRNAs, including hsa-miR-127-3p, mmu-miR-5100_L+2R-1, efu-miR-9226_L-2_1ss22GA, cgr-miR-1260_L+1, hsa-miR-652-3p_R+1, pal-miR-9993a-3p_L+2R-1, hsa-miR-7977_1ss6AG, hsa-miR-106b-3p_R-1, hsa-miR-186-5p, PC-3p-59611_111, hsa-miR-93-3p_R+1, and aeca-mir-8986a-p5_1ss1GA. There were 9165 target genes of age-associated miRNAs. Gene Ontology (GO) analysis of the target genes identified revealed enrichment of protein binding, membrane, cell cycle, and so on. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of age-related miRNAs for target genes revealed 139 enriched pathways, such as signaling pathways regulating stem cell pluripotency, metabolic pathways, and the Hippo signaling pathway. This suggests that miRNAs play a key role in male fertility changes with increasing age and provides new evidence for the study of the mechanism of age-related male fertility decline.

Y-shaped DNA nanostructures assembled-spherical nucleic acids as target converters to activate CRISPR-Cas12a enabling sensitive ECL biosensing.

Considering the trans-cleavage capabilities, high-specificity and programmability, the CRISPR-Cas system has been recognized as a valuable platform to develop the next-generation diagnostic biosensors. However, due to the natural interaction with nucleic acids, current CRISPR-Cas-based detection mostly applies in nucleic acid analysis rather than non-nucleic acid analysis. By virtue of spherical nucleic acids (SNAs) with programmability and specificity, the Y-shaped DNA nanostructures assembled-SNAs (Y-SNAs) were rationally designed as target converters to achieve the quantitative activation of CRISPR-Cas12a, enabling a highly specific and sensitive electrochemiluminescence (ECL) determination of alpha-methylacyl-CoA racemase (AMACR), a high specific protein biomarker of prostate cancer. Significantly, the Y-shaped DNA nanostructures comprised of assisted DNA (A1), AMACR aptamer and DNA activator of CRISPR-Cas12a were loaded on Au nanoparticles modified Fe3O4 magnetic beads (Au@Fe3O4 MBs) to construct the robust Y-SNAs. In the presence of the target AMACR, the Y-SNAs as target converters could achieve quantitative activation of CRISPR-Cas12a by outputting the DNA activators with a linear relationship to the target. The amplified ECL signals were triggered by the release of the ferrocene-labeled quenching probes (QPs) on the electrode surface due to the trans-cleavage activity of CRISPR-Cas12a, thereby realizing the sensitive ECL determination of AMACR from 10 ng/mL to 100 µg/mL with the detection limit of 1.25 ng/mL. In general, this approach provides novel perspectives on how to design a universal ECL platform of the CRISPR-Cas system to detect the non-nucleic acid targets beyond the traditional methods.

Neonatal apneic phenotype in a murine congenital central hypoventilation syndrome model is induced through non-cell autonomous developmental mechanisms.

Congenital central hypoventilation syndrome (CCHS) represents a rare genetic disorder usually caused by mutations in the homeodomain transcription factor PHOX2B. Some CCHS patients suffer mainly from deficiencies in CO2 and/or O2 respiratory chemoreflex, whereas other patients present with full apnea shortly after birth. Our goal was to identify the neuropathological mechanisms of apneic presentations in CCHS. In the developing murine neuroepithelium, Phox2b is expressed in three discrete progenitor domains across the dorsal-ventral axis, with different domains responsible for producing unique autonomic or visceral motor neurons. Restricting the expression of mutant Phox2b to the ventral visceral motor neuron domain induces marked newborn apnea together with a significant loss of visceral motor neurons, RTN ablation, and preBötzinger complex dysfunction. This finding suggests that the observed apnea develops through non-cell autonomous developmental mechanisms. Mutant Phox2b expression in dorsal rhombencephalic neurons did not generate significant respiratory dysfunction, but did result in subtle metabolic thermoregulatory deficiencies. We confirm the expression of a novel murine Phox2b splice variant which shares exons 1 and 2 with the more widely studied Phox2b splice variant, but which differs in exon 3 where most CCHS mutations occur. We also show that mutant Phox2b expression in the visceral motor neuron progenitor domain increases cell proliferation at the expense of visceral motor neuron development. We propose that visceral motor neurons may function as organizers of brainstem respiratory neuron development, and that disruptions in their development result in secondary/non-cell autonomous maldevelopment of key brainstem respiratory neurons.

Quality Evaluation of Tremella fuciformis Polysaccharides from Different Sources / 中国实验方剂学杂志

Objective:To establish a method for the determination of polysaccharide and monosaccharide composition of Tremella fuciformis, and to analyze the difference of polysaccharide content in T. fuciformis from different sources and cultivation methods, so as to provide reference for the quality determination.Method:High performance size exclusion chromatography coupled with multi-angle laser light scattering and refractive index detection (HPSEC-MALLS-RID) was employed to determine the content and relative molecular weight distribution of T. fuciformis polysaccharides. The monosaccharide types and proportions of T. fuciformis polysaccharides were analyzed by 1-phenyl-3-methyl-5-pyrazolone (PMP) precolumn derivative high performance liquid chromatography (HPLC).Result:The weight-average relative molecular weight (Mw) and the content of polysaccharides in T. fuciformis cultivated by cut-log from different sources were distributed in 2.618×106-3.503×106 Da and 307.12-609.06 g·kg-1, respectively. These two parameters of polysaccharides in T. fuciformis with substitute cultivation from different sources were 2.723×106-3.886×106 Da and 366.38-647.37 g·kg-1, respectively. The T. fuciformis polysaccharides mainly consisted of mannose, glucuronic acid, glucose, galactose, xylose and fucose, their ratios in samples with cut-log and substitute cultivation were 4.4∶0.7∶1.0∶0.2∶1.4∶1.6 and 4.4∶0.8∶1.0∶0.1∶1.5∶1.5, respectively. The contents of the above six monosaccharides in 39 batches of T. fuciformis from different sources were mannose of 36.71-191.31 g·kg-1, glucose of 10.46-76.10 g·kg-1, galactose of 1.00-6.72 g·kg-1, xylose of 16.73-70.54 g·kg-1, glucuronic acid of 9.74-32.12 g·kg-1, fucose of 17.16-68.20 g·kg-1.Conclusion:The content of polysaccharides in T. fuciformis from different sources has a certain difference, the developed method can be used as a routine method for the quality evaluation of polysaccharides in T. fuciformis.

Development of a Novel FIJI-Based Method to Investigate Neuronal Circuitry in Neonatal Mice.

The emergence of systems neuroscience tools requires parallel generation of objective analytical workflows for experimental neuropathology. We developed an objective analytical workflow that we used to determine how specific autonomic neural lineages change during postnatal development. While a wealth of knowledge exists regarding postnatal alterations in respiratory neural function, how these neural circuits change and develop in the weeks following birth remains less clear. In this study, we developed our workflow by combining genetic mouse modeling and quantitative immunofluorescent confocal microscopy and used this to examine the postnatal development of neural circuits derived from the transcription factors NKX2.2 and OLIG3 into three medullary respiratory nuclei. Our automated FIJI-based image analysis workflow rapidly and objectively quantified synaptic puncta in user-defined anatomic regions. Using our objective workflow, we found that the density and estimated total number of Nkx2.2-derived afferents into the pre-Bötzinger Complex significantly decreased with postnatal age during the first three weeks of postnatal life. These data indicate that Nkx2.2-derived structures differentially influence pre-Bötzinger Complex respiratory oscillations at different stages of postnatal development.

Differentially expressed genes in early gestational chorionic villi after administration of mifepristone.

To investigate the effect of mifepristone on gene expression of human chorionic villi in early pregnancy, nine women were recruited into a randomised controlled trial. All subjects were healthy women who had regular menstrual cycles and sought termination of pregnancy up to 40 days gestational age. In the test group, gestational sacs were taken by vacuum aspiration of the uterus 24 h after a single dose of 150 mg mifepristone was administered. Chorionic villi were collected and frozen in liquid nitrogen. The control samples were collected using the same method from the women without administration of mifepristone. The gene expressions of villus were monitored by human cDNA microarrays. It is found that the expressions of 262 transcripts were significantly altered in the test group. Gene ontology and pathways analyses were conducted to further analyse these genes. Many of these genes are known to play potentially an important role in the placentation and the molecular regulation of maternal-fetal interface. Therefore, it is suggested that the placental development and microenvironment of the maternal-fetal interface were interfered by administration of mifepristone. These data provide insight into the molecular mechanism about medical abortion induced by mifepristone.

Identification and characterization of a spermatogenesis-related gene Ube1 in rat testis / 生理学报

A gene that could be potentially involved in spermatogenesis was identified and characterized by using suppression subtractive hybridization (SSH) and rapid amplification of cDNA ends (RACE) with total RNA from type A spermatogonia and pachytene spermatocytes of rat. This gene consists of 3 433 base pairs (bp) with a complete open reading frame (ORF) of 3 171 bp and encodes a putative protein containing 1057 amino acids. The nucleotide sequence displays a 93% identity to mouse ubiquitin-activating enzyme E1, Chr Y 1 (Ube1y1) and an 82% identity to human ubiquitin-activating enzyme E1 (UBE1). The putative protein of this gene contains an ubiquitin-activating enzyme signature 1 and an ubiquitin-activating enzyme active site, which are also existed in mouse ubiquitin-activating enzyme E1, human ubiquitin-activating enzyme E1 et al. So we named this gene as Rattus norvegicus ubiquitin-activating enzyme E1 (Ube1). The sequence of Ube1 was submitted to GenBank and the accession number is EF690356. Reverse transcription-polymerase chain reaction (RT-PCR) analysis showed that Ube1 was specifically expressed in testis, while its expression was not detected in heart, brain, spleen, lung, liver, muscle, kidney and ovary. Comparison of the expression of Ube1 in different developmental stages of testis and Sertoli cells (real-time PCR) indicated that Ube1 was expressed more highly in spermatogonia than in spermatocytes, spermatids and Sertoli cells. In conclusion, Ube1 is a gene encoding rat ubiquitin-activating enzyme E1 and specifically expressed in testis, which might play a key role in ubiquitin system and influence spermatogenesis.

Screening differentially expressed genes in human bone marrow stromal cells at defined stage of differentiation / 生理学报

To screen differentially expressed genes involved in osteogenic differentiation of human bone marrow stromal cells (BMSCs) at defined stages, subtractive cDNA library was established by means of suppression subtractive hybridization. The BMSCs cultured for 12 and 21 d were used as driver and tester, respectively. A subtract library was successfully constructed and five positive clones were selected from the library. Sequencing analysis and homology comparison showed that the five clones differentially expressed in BMSCs cultured for 21 d were at least 90% homologous with the known genes in human GenBank. It was interestingly found that the osteogenic BMSCs cultured for 21 d differentially expressed decorin and Bax inhibitor 1. RT-PCR was performed to confirm the differentially expressed genes. The results showed that the expression of Bax inhibitor 1 was significantly higher in the cells of 21-day than that of 12-day, while the expression of decorin was only detected in the cells of 21-day.