PIWI-Interacting RNAs: A Pivotal Regulator in Neurological Development and Disease.

PIWI-interacting RNAs (piRNAs), a class of small non-coding RNAs (sncRNAs) with 24-32 nucleotides (nt), were initially identified in the reproductive system. Unlike microRNAs (miRNAs) or small interfering RNAs (siRNAs), piRNAs normally guide P-element-induced wimpy testis protein (PIWI) families to slice extensively complementary transposon transcripts without the seed pairing. Numerous studies have shown that piRNAs are abundantly expressed in the brain, and many of them are aberrantly regulated in central neural system (CNS) disorders. However, the role of piRNAs in the related developmental and pathological processes is unclear. The elucidation of piRNAs/PIWI would greatly improve the understanding of CNS development and ultimately lead to novel strategies to treat neural diseases. In this review, we summarized the relevant structure, properties, and databases of piRNAs and their functional roles in neural development and degenerative disorders. We hope that future studies of these piRNAs will facilitate the development of RNA-based therapeutics for CNS disorders.

Fam20c regulates the calpain proteolysis system through phosphorylating Calpasatatin to maintain cell homeostasis.

BACKGROUND: The family with sequence similarity 20-member C (FAM20C) kinase, a Golgi casein kinase, which is responsible for phosphorylating the majority of the extracellular phosphoproteins within S-x-E/pS motifs, and is fundamentally associated with multiple biological processes to maintain cell proliferation, biomineralization, migration, adhesion, and phosphate homeostasis. In dissecting how FAM20C regulates downstream molecules and potential mechanisms, however, there are multiple target molecules of FAM20C, particularly many phenomena remain elusive, such as changes in cell-autonomous behaviors, incompatibility in genotypes and phenotypes, and others. METHODS: Here, assay for transposase-accessible chromatin using sequencing (ATAC-seq), RNA sequencing (RNA-seq), proteomics, and phosphoproteomics were performed in Fam20c-dificient osteoblasts and to facilitate an integrated analysis and determine the impact of chromatin accessibility, genomic expression, protein alterations, signaling pathway, and post translational modifcations. RESULTS: By combining ATAC-seq and RNA-seq, we identified TCF4 and Wnt signaling pathway as the key regulators in Fam20c-dificient cells. Further, we showed Calpastatin/Calpain proteolysis system as a novel target axis for FAM20C to regulate cell migration and F-actin cytoskeleton by integrated analysis of proteomics and phosphoproteomics. Furthermore, Calpastatin/Calpain proteolysis system could negatively regulate the Wnt signaling pathway. CONCLUSION: These observations implied that Fam20c knockout osteoblasts would cause cell homeostatic imbalance, involving changes in multiple signaling pathways in the conduction system.

Integrative epigenome profiling of 47XXY provides insights into whole genomic DNA hypermethylation and active chromatin accessibility.

Klinefelter syndrome (KS, 47XXY) is a disorder characterized by sex chromosomal aneuploidy, which may lead to changes in epigenetic regulations of gene expression. To define epigenetic architectures in 47XXY, we annotated DNA methylation in euploid males (46XY) and females (46XX), and 47XXY individuals using whole genome bisulfite sequencing (WGBS) and integrated chromatin accessbilty, and detected abnormal hypermethylation in 47XXY. Furthermore, we detected altered chromatin accessibility in 47XXY, in particular in chromosome X, using Assay for Transposase-Accessible Chromatin sequencing (ATAC-seq) in cultured amniotic cells. Our results construct the whole genome-wide DNA methylation map in 47XXY, and provide new insights into the early epigenomic dysregulation resulting from an extra chromosome X in 47XXY.

Correlation between plasma glutathione peroxidase 4 and N-acetylneuraminic acid levels with clinical risk stratification and prognosis of patients with acute coronary syndrome.

OBJECTIVES: To investigate the correlation between plasma glutathione peroxidase 4 (GPX4) and N-acetyl-neuraminic acid (Neu5Ac) with clinical risk stratification and outcomes of acute coronary syndrome (ACS) patients. METHODS: Between October 2018 and July 2019, 413 patients that were scheduled for coronary angiography were enrolled in this prospective study at the First Affiliated Hospital of Bengbu Medical College, Bengbu, China. Patients were divided into control and ACS groups. Patients with ACS were divided into 3 risk levels based on their thrombolysis in myocardial infarction risk score. After discharge, ACS patients were followed for the incidence of major adverse cardiac events (MACEs). For the analysis of cumulative endpoint event occurrences, the Kaplan-Meier method was applied. RESULTS: The ACS group had lower plasma GPX4 but higher Neu5Ac levels than the control group. There was a greater increase in plasma Neu5Ac in the high-risk group when compared with the medium-risk and low-risk groups, while GPX4 levels were higher in the low-risk group. The MACEs group had higher plasma Neu5Ac but lower GPX4 levels than the non-MACEs group. The plasma Neu5Ac was an independent risk factor but GPX4 was a protective factor for MACEs. CONCLUSION: Glutathione peroxidase 4 and Neu5Ac levels in plasma can be used to diagnose, stratify risks, and predict long-term outcomes in patients with ACS.

Characterization of plasma exosomal microRNAs in responding to radiotherapy of human esophageal squamous cell carcinoma.

Radiotherapy is one of the main treatment methods for esophageal squamous cell carcinoma (ESCC). Previous research has shown that plasma exosomal microRNAs (miRNAs) can predict therapeutic outcome. In the present study, to identify potential exosomal miRNAs that respond to radiotherapy, plasma exosomal miRNAs from ESCC patients undergoing radiotherapy were isolated and sequenced. Upregulated and downregulated miRNAs were detected from patients pre­ and post­radiotherapy, and it was found that they play distinct roles in DNA damage process and endosomal mediated transport. Based on wound healing and Cell Counting Kit­8 assays in TE­1 human esophageal cancer cells, it was identified that representative miRNA miR­652 and miR­30a alter migration but not proliferation. The present findings identified differentially expressed miRNAs in responding to radiotherapy, and added a reference to explore non­invasive plasma biomarkers to evaluate therapeutic effects in ESCC.

Transcriptional responses of fluxapyroxad-induced dysfunctional heart in zebrafish (Danio rerio) embryos.

Fluxapyroxad (FLU) is a succinate dehydrogenase inhibitor (SDHI) fungicide used in controlling crop diseases. Potential toxicity to aquatic organisms is not known. We exposed zebrafish to 1, 2, and 4 µM FLU for 3 days. The embryonic zebrafish showed developmental cardiac defects, including heart malformation, pericardial edema, and heart rate reduction. Compared with the controls, cardiac-specific transcription factors (nkx2.5, myh7, myl7, and myh6) exhibited dysregulated expression patterns after FLU treatment. We next used transcriptome and qRT-PCR analyses to explore the molecular mechanism of FLU cardiotoxicity. The transcriptome analysis and interaction network showed that the downregulated genes were enriched in calcium signaling pathways, adrenergic signaling in cardiomyocytes, and cardiac muscle contraction. FLU exposure repressed the cardio-related calcium signaling pathway, associated with apoptosis in the heart and other manifestations of cardiotoxicity. Thus, the findings provide valuable evidence that FLU exposure causes disruption of cardiac development in zebrafish embryos. Our findings will help to promote a better understanding of the toxicity mechanisms of FLU and act as a reference to explore the rational use and safety of FLU in agriculture.

Single-Cell Transcriptomics of Cultured Amniotic Fluid Cells Reveals Complex Gene Expression Alterations in Human Fetuses With Trisomy 18.

Trisomy 18, commonly known as Edwards syndrome, is the second most common autosomal trisomy among live born neonates. Multiple tissues including cardiac, abdominal, and nervous systems are affected by an extra chromosome 18. To delineate the complexity of anomalies of trisomy 18, we analyzed cultured amniotic fluid cells from two euploid and three trisomy 18 samples using single-cell transcriptomics. We identified 6 cell groups, which function in development of major tissues such as kidney, vasculature and smooth muscle, and display significant alterations in gene expression as detected by single-cell RNA-sequencing. Moreover, we demonstrated significant gene expression changes in previously proposed trisomy 18 critical regions, and identified three new regions such as 18p11.32, 18q11 and 18q21.32, which are likely associated with trisomy 18 phenotypes. Our results indicate complexity of trisomy 18 at the gene expression level and reveal genetic reasoning of diverse phenotypes in trisomy 18 patients.

The effect and mechanism of gene Fam20a on the development and function of salivary glands in mice.

OBJECTIVE: The influence of the knockout of gene Fam20a on mice salivary glands was studied in this research, to provide a potential gene therapeutic target for salivary gland dysfunction. DESIGN: The control group with genotype Fam20af/f and conditional knockout (cKO) group with Fam20af/f;K14-Cre were constructed with Cre-Loxp. The influence of Fam20a on the salivary glands was studied in terms of morphology, functionality and molecular mechanism. RESULTS: In terms of morphology, the cross-sectional area ratio of ductal to the total was reduced in the cKO mice, while that of extracellular matrix to the total was increased. At the sub-microscopic level, the knockout of Fam20a led to abnormal sub-microscopic structure of the duct cells. Functionally, saliva flow rate was significantly reduced in cKO mice. The result was consistent with the change of acinar cell marker Aquaporin 5 which was abnormally diffusely expressed in the cytoplasm of acinar cells. Meanwhile, the expression of ductal cell markers Cytokeratin 7 and nerve growth factor ß were significantly decreased, suggesting the abnormal development and function of the duct cells. The research on the mechanism reveals that the loss of Fam20a led to the decreased expression and varied localization of bone morphogenetic protein 4 (BMP4), and a significant decrease of the proportion of phosphorylated extracellular signal-regulated protein1/2 (ERK1/2) to total ERK1/2. These changes suggested that the loss of Fam20a attenuated the activity of the BMP/ERK signaling pathway. CONCLUSIONS: Fam20a affects the morphology and function of salivary glands, probably by attenuating the activity of the BMP/ERK signaling pathway.

Correlation of serum N-Acetylneuraminic acid with the risk and prognosis of acute coronary syndrome: a prospective cohort study.

BACKGROUND: N-acetylneuraminic acid (Neu5Ac) is a functional metabolite involved in coronary artery disease (CAD). We aimed to evaluate the relationship between serum Neu5Ac and the risk and prognosis of acute coronary syndrome (ACS) in a real-world prospective study. METHODS: Patients with suspected ACS who underwent coronary angiography were included. Serum Neu5Ac was measured at admission. Coronary lesion severity was evaluated by Gensini Score. GRACE risk stratification was performed at admission. Major adverse cardiac events (MACEs) were recorded during follow-up. RESULTS: A total of 766 patients, including 537 with unstable angina (UAP), 100 with myocardial infarction (MI), and 129 without CAD were included. The circulating Neu5Ac level was significantly higher in patients with MI (median [1QR]: 297[220, 374] ng/ml) than in those with UAP (227 [114, 312] ng/ml) or without CAD (207 [114, 276] ng/ml; both p < 0.001). Serum level of Neu5Ac was positively correlated with age, hypertension, serum uric acid, creatinine, MB isoform of creatine kinase (CK-MB), and Gensini score (all p < 0.05). Receiver operating characteristic curve analysis showed that a higher serum Neu5Ac was potentially associated with MI and high-risk GRACE stratification in ACS patients. Logistic analysis identified only elevated serum Neu5Ac as an independent predictor of MACEs in these patients (odds ratio [OR]: 1.003, 95% confidence interval [CI]: 1.002-1.005, p < 0.001). CONCLUSIONS: Serum Neu5Ac is associated with myocardial injury, GRACE risk category, and prognosis in ACS patients.

Differential expression of microRNAs in the human fetal left and right cerebral cortex.

Human brain is anatomically and functionally asymmetric. How brain asymmetry is initiated and established during fetal development is poorly understood. Accumulating evidence has shown that microRNAs (miRNAs) play crucial roles in brain development and function. In this study, we investigate miRNA expression profiles in left and right hemispheres of human fetal brains at 12 weeks post conception (PC), and identify 42 miRNAs showing differential expression between two hemispheres using Affymetrix microarray analyses. Target genes for left- and right-biased miRNAs are largely involved in developmental and functional regulations in the cortex such as axon guidance, GABAergic synapse and dopaminergic synapse pathways. Moreover, we find that predicted targets associated with canonical and non-canonical WNT signaling pathway show variations and differential expression between two hemispheres in response to left- and right-biased miRNAs. Our results highlight a potential role of miRNAs in regulating asymmetric development of human fetal brains.

Detect accessible chromatin using ATAC-sequencing, from principle to applications.

BACKGROUND: Chromatin accessibility is crucial for gene expression regulation in specific cells and in multiple biological processes. Assay for Transposase Accessible Chromatin with high-throughput sequencing (ATAC-seq) is an effective way to reveal chromatin accessibility at a genome-wide level. Through ATAC-seq, produced reads from a small number of cells reflect accessible regions that correspond to nucleosome positioning and transcription factor binding sites, due to probing hyperactive Tn5 transposase to DNA sequence. CONCLUSION: In this review, we summarize both principle and features of ATAC-seq, highlight its applications in basic and clinical research. ATAC-seq has generated comprehensive chromatin accessible maps, and is becoming a powerful tool to understand dynamic gene expression regulation in stem cells, early embryos and tumors.

Clinical characteristics of patients with premature acute coronary syndrome and adverse cardiovascular events after PCI.

Few studies have compared the clinical manifestations of patients with premature acute coronary syndrome (ACS) and late-onset ACS as well as the adverse cardiovascular events following percutaneous coronary intervention (PCI). To investigate the clinicopathological characteristics of patients with premature ACS and adverse cardiovascular events following PCI, a total of 726 patients with ACS undergoing PCI were divided into two groups: A premature ACS group and a late-onset ACS group. Following discharge, all patients were followed-up for an average of 23.5±5.3 months. Clinical characteristics, Gensini scores, vascular lesions and adverse cardiovascular events were compared between the two groups. There were no significant differences in smoking, diabetes, ACS composition ratio, baseline treatment of coronary heart disease, high-density lipoprotein level and C-reactive protein levels between the two groups. Sex and hypertriglyceridemia were determined to be independent risk factors of premature ACS, while age, hypertension and a high Gensini score were independent risk factors for adverse cardiovascular events in patients with ACS following PCI. Furthermore, the prevalence of premature ACS was significantly higher in females. Although serum levels of fasting blood glucose, total cholesterol, triglycerides and low-density lipoprotein were also significantly higher in patients with premature ACS compared with patients with late-onset ACS, patients with premature ACS exhibited fewer vascular lesions compared with patients with late-onset ACS. Furthermore, the incidence of adverse cardiovascular events in patients with ACS following PCI did not differ significantly between premature and late-onset ACS groups. Taken together, these results suggest that female patients should be closely observed for early risk factors of premature ACS to prevent and reduce the occurrence of adverse cardiovascular events in patients with ACS following PCI.

Loss of Fam20c causes defects in the acinar and duct structure of salivary glands in mice.

Family with sequence similarity 20­member C (FAM20C), a recently characterized Golgi kinase, performs numerous biological functions by phosphorylating more than 100 secreted proteins. However, the role of FAM20C in the salivary glands remains undefined. The present study demonstrated that FAM20C is mainly located in the cytoplasm of duct epithelial cells in the salivary glands. Fam20cf/f; Mmtv­Cre mice were created in which Fam20c was inactivated in the salivary gland cells and observed that the number of ducts and the ductal cross­sectional area increased significantly, while the number of acinar cells was reduced. The granular convoluted tubules (GCTs) exhibited an accumulation of aberrant secretory granules, along with a reduced expression and altered distribution patterns of ß nerve growth factor, α­amylase and bone morphogenetic protein (BMP) 4. This abnormality suggested that the GCT cells were immature and exhibited defects in developmental and secretory functions. In accordance with the morphological alterations and the reduced number of acinar cells, FAM20C deficiency in the salivary glands significantly decreased the salivary flow rate. The Na+, Cl- and K+ concentrations in the saliva were all significantly increased due to dysfunction of the ducts. Furthermore, Fam20c deficiency significantly increased BMP2 and BMP7 expression, decreased BMP4 expression, and attenuated the canonical and noncanonical BMP signaling pathways in the salivary glands. Collectively, the results of the present study demonstrate that FAM20C is a key regulator of acinar and duct structure and duct maturation and provide a novel avenue for investigating novel therapeutic targets for oral diseases including xerostomia.

Revealing cellular and molecular complexity of the central nervous system using single cell sequencing.

The mammalian central nervous system (CNS) is one of the most complex systems, with thousands of cell types and subtypes with distinct and unique morphology and gene expression profiles. Based on classic histological methods and conventional cellular and molecular approaches, single cell sequencing is becoming a powerful tool to uncover the complexity of the CNS. In this review, we summarize the principle of single cell sequencing and highlight its use for studying the development of neural stem cells, neural progenitors, and distinct neurons. By revealing transcriptomes in each individual cell using single cell sequencing, we are now able to dissect the cellular heterogeneity of a hundred billion cells in the CNS and comprehensively investigate mechanisms of brain development and function at the cellular and molecular levels.

Aspirin promotes osteogenic differentiation of human dental pulp stem cells.

Human dental pulp stem cells (hDPSCs) possess self­renewal and osteogenic differentiation properties, and have been used for orofacial bone regeneration and periodontal treatment. Aspirin has been demonstrated to enhance the regeneration of bone marrow mesenchymal stem cells (MSCs); however, the impact of aspirin on the osteogenic differentiation of hDPSCs remains unknown. In the present study, hDPSCs were characterized by flow cytometry, while their clonogenic potential and multipotency were assessed using alizarin red, Oil red O and alcian blue staining. The effect of aspirin on hDPSC viability was assessed using Cell Counting Kit­8 assay. Osteogenic capacity was examined by alkaline phosphatase activity, alizarin red staining, reverse transcription­polymerase chain reaction and western blotting. Furthermore, in vivo cranial defects were established in Sprague­Dawley rats to evaluate the effect of aspirin on hDPSC­based bone regeneration. Anorganic bovine bone was used as a bone replacement material and as the carrier for hDPSCs. New bone formation was observed through radiographic and histological analysis. The study demonstrated that hDPSCs expressed MSC markers and possessed multipotency in vitro. Aspirin was non­toxic to hDPSCs at a concentration of ≤100 µg/ml and enhanced the osteogenesis of hDPSCs in vitro. Aspirin significantly increased hDPSC­based bone formation in the rat cranial defect model at 8 or 12 weeks post­implantation (P<0.05). The data suggested that aspirin promotes the osteogenic potential of hDPSCs in vitro and in vivo. Overall, the present study indicated that aspirin improves the bone regeneration capacity of hDPSCs.

Opposite Roles of Wnt7a and Sfrp1 in Modulating Proper Development of Neural Progenitors in the Mouse Cerebral Cortex.

The Wingless (Wnt)-mediated signals are involved in many important aspects of development of the mammalian cerebral cortex. How Wnts interact with their modulators in cortical development is still unclear. Here, we show that Wnt7a and secreted frizzled-related protein 1 (Sfrp1), a soluble modulator of Wnts, are co-expressed in mouse embryonic cortical neural progenitors (NPs). Knockout of Wnt7a in mice causes microcephaly due to reduced NP population and neurogenesis, and Sfrp1 has an opposing effect compared to Wnt7a. Similar to Dkk1, Sfrp1 decreases the Wnt1 and Wnt7a activity in vitro. Our results suggest that Wnt7a and Sfrp1 play opposite roles to ensure proper NP progeny in the developing cortex.

Long noncoding RNA Sox2ot and transcription factor YY1 co-regulate the differentiation of cortical neural progenitors by repressing Sox2.

Long noncoding RNAs (lncRNAs) are emerging as key regulators of crucial cellular processes. However, the molecular mechanisms of many lncRNA functions remain uncharacterized. Sox2ot is an evolutionarily conserved lncRNA that transcriptionally overlaps the pluripotency gene Sox2, which maintains the stemness of embryonic stem cells and tissue-specific stem cells. Here, we show that Sox2ot is expressed in the developing mouse cerebral cortex, where it represses neural progenitor (NP) proliferation and promotes neuronal differentiation. Sox2ot negatively regulates self-renewal of neural stem cells, and is predominately expressed in the nucleus and inhibits Sox2 levels. Sox2ot forms a physical interaction with a multifunctional transcriptional regulator YY1, which binds several CpG islands in the Sox2 locus in a Sox2ot-dependent manner. Similar to Sox2ot, YY1 represses NP expansion in vivo. These results demonstrate a regulatory role of Sox2ot in promoting cortical neurogenesis, possibly by repressing Sox2 expression in NPs, through interacting with YY1.

Hippocampal MicroRNAs Respond to Administration of Antidepressant Fluoxetine in Adult Mice.

Current antidepressant treatments to anxiety and depression remain inadequate, burdened by a significant percentage of misuse and drug side-effects, due to unclear mechanisms of actions of antidepressants. To better understand the regulatory roles of antidepressant fluoxetine-related drug reactions, we here investigate changes of expression levels of hippocampal microRNAs (miRNAs) after administration of fluoxetine in normal adult mice. We find that 64 miRNAs showed significant changes between fluoxetine treatment and control groups by analyzing 626 mouse miRNAs. Many miRNAs in response to fluoxetine are involved in neural-related signaling pathways by analyzing miRNA-target gene pairs using the Kyoto encyclopedia of genes and genomes (KEGG) and Gene Ontology (GO). Moreover, miRNAs with altered expression are mainly associated with the repression of the dopaminergic synapse signals, which may affect hippocampal function after fluoxetine treatment. Our results demonstrate that a number of miRNAs respond to antidepressants even in normal mice and may affect target gene expression, which supports the safety consideration of inappropriate treatment and off-label use of antidepressant drugs.

Aspirin-induced attenuation of adipogenic differentiation of bone marrow mesenchymal stem cells is accompanied by the disturbed epigenetic modification.

Aspirin has positive effects on bone marrow mesenchymal stem cells (BMSCs) osteogenic differentiation. However, researchers did not give much thought to its effect on BMSCs adipogenic differentiation. Here, we analyzed the effect of aspirin on the BMSCs adipogenic differentiation. To detect whether the effect of aspirin on the adipogenic differentiation of BMSCs is associated with the disturbed epigenetic modification, the expression of histone deacetylases (HDACs), activity of HDACs and HAT, global histone H3 acetylation and H3k9 acetylation alterations were investigated. Moreover, to further explore and understand the binding mode between aspirin and HDACs, an attempt was made to identify the interaction between aspirin and the HDACs with the aid of in silico docking study. The results showed that aspirin could induce inhibition of BMSCs adipogenesis. The level of HDAC activity, global histone H3 acetylation, and H3k9 acetylation were all down regulated during adipogenic differentiation, and aspirin can reverse these decreases. Furthermore, the HDAC isoforms have different expression patterns in those progresses. The expression of HDAC9 was increased in a does-dependent manner when aspirin was introduced during BMSCs adipogenic differentiation. Docking study showed that high affinity of HDAC9 to aspirin was existed, suggesting that HDAC9 may has an important role in the process of aspirin-induced suppression of adipogenesis. Further studies are needed to define the intricate mechanisms of the HDAC isoforms, and all of these enable us to understand aspirin and its efficacy of inhibition of adipogenic differentiation and pave the way to aspirin clinical using for the tissue regenerating.

MTHFR C677T gene polymorphism and the severity of coronary lesions in acute coronary syndrome.

The association between methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism, circulating levels of homocysteine (Hcy), and the severity of coronary lesion in patients with acute coronary syndrome (ACS) remains unknown.Consecutive ACS patients were included. MTHFR C677T polymorphisms were determined via amplification refractory mutation system-polymerase chain reaction (ARMS-PCR). Gensini scores were used to evaluate the severity of coronary lesions.Three hundred ten ACS patients were included, and grouped according to the MTHFR C677T polymorphism variant: CC (n = 78, 25.2%), CT (n = 137, 44.2%), and TT (n = 95, 30.6%) groups. No significant differences were detected with respect to baseline characteristics. Patients in TT group had significantly higher Hcy, and significantly lower folic acid (FA) levels as compared with those in the other 2 groups (P < .05 for both). More importantly, patients with TT had more severe coronary lesions as compared with those from the other 2 groups, as evidenced by higher Gensini scores (P < .05 for both); however, no significant differences were observed with respect to the numbers of affected coronary arteries, or the number, length, and diameter of stents implanted in each group (P > .05 for all). On multivariate logistic regression analysis, presence of a T allele in MTHFR C677T was found to be independently associated with higher circulating Hcy (odds ratio [OR] = 1.06, 95% confidence interval [CI]: 1.01-1.12, P = .024), and higher Gensini scores (OR: 1.01, 95% CI: 1.00-1.02, P = .046).MTHFR C677T TT polymorphism was associated with higher Hcy levels and more severe coronary lesions in patients with ACS.