Hirschsprung disease (HSCR), one of several neurocristopathies in children, is characterized by nerve loss in the large intestine and is mainly treated by surgery, which causes severe complications. Enteric neural crest-derived cell (ENCC) transplantation is a potential therapeutic strategy; however, so far with poor efficacy. Here, we assessed whether and how fecal microbiota transplantation (FMT) could improve ENCC transplantation in a rat model of hypoganglionosis; a condition similar to HSCR, with less intestinal innervation. We found that the hypoganglionosis intestinal microenvironment negatively influenced the ENCC functional phenotype in vitro and in vivo. Combining 16S rDNA sequencing and targeted mass spectrometry revealed microbial dysbiosis and reduced short-chain fatty acid (SCFA) production in the hypoganglionic gut. FMT increased the abundance of Bacteroides and Clostridium, SCFA production, and improved outcomes following ENCC transplantation. SCFAs alone stimulated ENCC proliferation, migration, and supported ENCC transplantation. Transcriptomewide mRNA sequencing identified MAPK signaling as the top differentially regulated pathway in response to SCFA exposure, and inhibition of MEK1/2 signaling abrogated the SCFA-mediated effects on ENCC. This study demonstrates that FMT improves cell therapy for hypoganglionosis via short-chain fatty acid metabolisminduced MEK1/2 signaling.
New Findings What is the central question of this study?Long non‐coding RNAs (lncRNAs) are widely involved in the progression of Hirschsprung's disease (HSCR), but the role of actin filament associated protein 1 antisense RNA1 (AFAP1‐AS1), an lncRNA, in HSCR has not been explored before. What is the main finding and its importance?Downregulation of AFAP1‐AS1 blocks enteric neural crest stem cell proliferation, differentiation, migration and invasion and promotes the occurrence of HSCR via the miR‐195/E2F3 axis, indicating thatAFAP1‐AS might be a potential biomarker for HSCR patients. Abstract Long non‐coding RNAs (lncRNAs) are involved in several human disorders. Nevertheless, it remains unclear whether they are implicated in the phenotypes of enteric neural crest stem cells (ENCSCs) in Hirschsprung's disease (HSCR). Therefore, we designed this study to explore the pathogenicity of AFAP1‐AS1 for HSCR. Microarray analysis and bioinformatic tools were used to screen out the differentially lncRNAs and microRNAs (miRNAs) in patients with HSCR. Small interference RNA transfection was applied to carry out functional experiments in ENCSCs. Cellular activities were detected by cell counting kit‐8, 5‐ethynyl‐2′‐deoxyuridine, Transwell assays and flow cytometry. Finally, rescue experiments were performed to examine the cofunction of AFAP1‐AS1 and miR‐195 and of miR‐195 and E2F transcription factor 3 (E2F3). AFAP1‐AS1 was reduced in HSCR patients. Meanwhile, knockdown of AFAP1‐AS1 reduced the cell migratory and proliferative capacities and facilitated cell apoptosis along with G0/G1 phase arrest. E2F3 was diminished when miR‐195 was upregulated, and AFAP1‐AS1 inhibition reduced its ability to bind to miR‐195. Altogether, AFAP1‐AS1 silencing acts as an endogenous RNA by interacting with miR‐195 to alter E2F3 expression, thus conferring repressive effects on ENCSC activity and promoting HSCR progression.
ObjectiveHirschsprung disease (HSCR) is one of the common neurocristopathies in children, which is associated with at least 20 genes and involves a complex regulatory mechanism. Transcriptional regulatory network (TRN) has been commonly reported in regulating gene expression and enteric nervous system development but remains to be investigated in HSCR. This study aimed to identify the potential TRN implicated in the pathogenesis and diagnosis of HSCR.MethodsBased on three microarray datasets from the Gene Expression Omnibus database, the multiMiR package was used to investigate the microRNA (miRNA)–target interactions, followed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. Then, we collected transcription factors (TFs) from the TransmiR database to construct the TF–miRNA–mRNA regulatory network and used cytoHubba to identify the key modules. Finally, the receiver operating characteristic (ROC) curve was determined and the integrated diagnostic models were established based on machine learning by the support vector machine method.ResultsWe identified 58 hub differentially expressed microRNAs (DEMis) and 16 differentially expressed mRNAs (DEMs). The robust target genes of DEMis and DEMs mainly enriched in several GO/KEGG terms, including neurogenesis, cell–substrate adhesion, PI3K–Akt, Ras/mitogen-activated protein kinase and Rho/ROCK signaling. Moreover, 2 TFs (TP53andTWIST1), 4 miRNAs (has-miR-107,has-miR-10b-5p,has-miR-659-3p, andhas-miR-371a-5p), and 4 mRNAs (PIM3,CHUK,F2RL1, andCA1) were identified to construct the TF–miRNA–mRNA regulatory network. ROC analysis revealed a strong diagnostic value of the key TRN regulons (all area under the curve values were more than 0.8).ConclusionThis study suggests a potential role of the TF–miRNA–mRNA network that can help enrich the connotation of HSCR pathogenesis and diagnosis and provide new horizons for treatment.
Neuroblastoma, a malignant tumor of the sympathetic nervous system, is an aggressive extracranial tumor in childhood. Long noncoding RNAs (lncRNAs) have been discovered to play a key role in the eukaryotic regulatory gene network and be involved in a wide variety of biological processes. We observed that the expression of lncRNA nuclear-enriched abundant transcript-1 (NEAT1) was significantly decreased in human neuroblastoma tissues and cell lines, compared with the normal. We observed cell proliferation, migration, and invasion with Cell Counting Kit-8 assay, colony formation assay, and Transwell assay to investigate the effects of NEAT1, miR-183-5p, or FOXP1 on neuroblastoma cells. And we also used StarBase and luciferase reporter gene assay to predict and confirm the interaction of NEAT1, miR-183-5p, and FOXP1 in neuroblastoma cells. First, overexpression of NEAT1 suppressed cell proliferation and played a key role in cell migration and invasion. In addition, NEAT1 was demonstrated to directly interact with miR-183-5p and exerted its antioncogenic role in neuroblastoma by negatively regulating miR-183-5p expression. miR-183-5p suppressed the expression of FOXP1 and regulated cell proliferation and migration by directly targeting FOXP1 mRNA 3′-untranslated region. Moreover, FOXP1 antagonized the effect of miR-183-5p on the phosphorylation of extracellular-regulated kinase/protein kinase B (ERK/AKT), while FOXP1 siRNA increased the reduced phosphorylation of ERK/AKT caused by miR-183-5p inhibitor in neuroblastoma cells. Taken together, these data showed that NEAT1 negatively regulated cell proliferation and migration of neuroblastoma by the miR-183-5p/FOXP1 axis via suppression of the ERK/AKT pathway. Our findings may provide a new target for the study of pathogenesis and treatment of neuroblastoma.
Background Hirschsprung's disease (HSCR) is a congenital gastrointestinal disorder, characterized by enteric ganglia absence in part or entire of the colon, due to abnormal colonization and migration of enteric neural crest cells (ENCCs) during development. Currently, besides surgery which is the main therapy for HSCR, the potential of stem cell‐based transplantation was investigated as an alternative option. Although promising, it has limitations, including poor survival, differentiation, and migration of the grafted cells. We hypothesized that modulation of extracellular factors during transplantation could promote ENCCs proliferation and migration, leading to increased transplantation efficiency. Considering that the RhoA/ROCK pathway is highly involved in cytoskeletal dynamics and neurite growth, our study explored the effect of inhibition of this pathway to improve the success of ENCCs transplantation. Methods Enteric neural crest cells were isolated from rat embryos and labeled with a GFP‐tag. Cell viability, apoptosis, differentiation, and migration assays were performed with and without RhoA/ROCK inhibition. Labeled ENCCs were transplanted into the muscle layer of an induced hypoganglionic rat model followed by intraperitoneal injections of ROCK inhibitor. The transplanted segments were collected 3 weeks after for histological analysis. Key Results Our results showed that inhibition of ROCK increased viable cell number, differentiation, and migration of ENCCs in vitro. Moreover, transplantation of labeled ENCCs into the hypoganglionic model showed enhanced distribution of grafted ENCCs, upon treatment with ROCK inhibitor. Conclusions and Inferences ROCK inhibitors influence ENCCs growth and migration in vitro and in vivo, and should be considered to improve the efficiency of ENCCs transplantation.
Background: Angiocidin plays a key role in angiogenesis and tumor progression. High angiocidin expression is detected in some kind of solid tumors and tumor vascular endothelial cells. Several reports have shown the inhibition of angiogenesis and tumor growth caused by angiocidin. However, the role of angiocidin in liver cancers growth is still unclear. Objectives: To examine angiocidin expression in SMMC-7221 and HepG2 cells and the role of angiocidin in liver cancer cell growth. Methods: RT-PCR and western blot are used in this study to detect angiocidin expression. SiRNA and MTT experiments are used in exploring the role of angiocidin in tumor cell growth. Results: Our study showed high angiocidin expression in two kinds of liver cancer cells. Angiocidin protein production in HepG2 cells were reduced significantly by siRNA. When HepG2 cells were transfected with siRNA-angiocidin, these cells showed very low proliferation activity compared with control cells. Our study suggests that reduction of angiocidin may contribute to decreased proliferation activity in liver cancer cells. Conclusion: Angiocidin is highly expressed in liver cancer cells, and it may play a key role in tumor growth of liver cancers.
In this paper, a phase-shifted full-bridge converter based on an adjustable current auxiliary circuit is proposed. The converter's switches achieve ZVS with the help of the parallel current provided by the auxiliary circuit. The conduction loss of the parallel current is reduced since the magnitude of the current can be adjusted by the variable inductor. Since there is no additional series inductor, the duty cycle loss of the proposed converter is minimal. Moreover, the oscillating voltage on the secondary side decays quickly, indicating that the energy involved in the oscillation is small, which is beneficial to reduce the loss of the RCD. The experimental platform is built. On this basis, theoretical analysis and experimental verification are carried out in this paper.duty cycle loss, parallel current, phase-shifted full-bridge (PSFB), variable inductor, zerovoltage switching (ZVS) | INTRODUCTIONPhase shifted full bridge converters are widely used in communication, aerospace, and other fields because of their simple structure, ZVS characteristics, high reliability, and other advantages. However, the lagging-leg switches of conventional phase-shifted full-bridge converters cannot realize ZVS under light load, which will reduce the efficiency and cause electromagnetic interference. And the conduction loss of the primary side circulating current increases with the phase shift angle. Moreover, the voltage oscillation on the secondary side diode increases its voltage stress. These disadvantages limit the higher efficiency and higher power density of the PSFB converter.The PSFB converter first proposed in Steigerwald and Ngo 1 has a simple structure, including a full bridge, transformer, rectifier diode, and LC filter. At present, many improved topologies have been proposed to eliminate the above disadvantages. The common method is to increase the inductance in series with the transformer, which can be realized by adding a series inductor or increasing the leakage inductance of the transformer. 2,3 This method can broaden the ZVS range of switches; that is, the switches can realize ZVS under light load. However, the commutation of the primary side current is slow due to the increase of the series inductance, which leads to a large duty cycle loss under heavy load.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.