BACKGROUND:Unlike linear RNAs,circular RNAs (circRNAs) are a novel type of RNA which can form covalently closed circles and are highly expressed in eukaryotic transcriptomes.In the plenitude of naturally occurring RNAs,circRNAs and their biological role are underestimated for years.Recent studies have discovered thousands of endogenous circRNAs in mammalian cells.OBJECTIVE:To review the formation,properties,and functions of circRNAs,and their potential significance in diseases.METHODS:A computer-based search for literature in CNKI and PubMed databases published from January 2000 to December 2016 was performed using the keywords of "circRNA,miRNA,function,mechanism" in English and Chinese,respectively.Finally,62 eligible articles were included for analysis.RESULTS AND CONCLUSION:CircRNAs are largely generated from exonic or intronic sequences,and reverse complementary sequences or RNA-binding proteins are necessary for circRNA biogenesis.A majority of circRNAs that are conserved across specie are stable and resistant to RNaseR,and often exhibit tissue/developmental-stage-specific expression.Recent research has revealed that circRNAs can function as microRNA sponges,regulators of splicing and transcription,and modifiers of parental gene expression.Emerging evidence indicates that circRNAs might play important roles in atherosclerotic vascular diseases,neurological disorders,prion diseases and cancer;exhibit aberrant expression in colorectal cancer;and serve as diagnostic or predictive biomarkers of some diseases.Similar to microRNAs and long noncoding RNAs,circRNAs are arousing general interest in the field of RNA and widely participate in the life process.

Accidents, Occupational ; statistics & numerical data ; China ; epidemiology ; Humans

OBJECTIVETo investigate the effects of phosphorylated mitogen-activated protein kinases (MAPK), including the phosphorylated extracellular signal-regulated protein kinase 1/2 (p-ERK1/2), the phosphorylated protein p38 (p-p38), the phosphorylated c-Jun N-terminal kinase (p-JNK), on phosgene inhalation-induced lung injury and its relationship with matrix metalloproteinase 9 (MMP-9).

METHODSAccording to the random number table, 30 male Wistar rats were divided into air control group (C), phosgene inhalation group (P), PD98059 (specific inhibitor of ERK1/2) group, SB203580 (specific inhibitor of p38) group, and SP600125 (specific inhibitor of JNK) group, with 6 rats in each group. The number of neutrophils in the bronchoalveolar lavage fluid (BALF) was counted and the lung wet-dry ratio (W/D) was examined. The serum levels of inflammatory factors TNF-α, IL-1β, IL-6, and IL-8 were determined with ELISA. The protein expressions of p-ERK1/2, p-p38, p-JNK, and MMP-9 in lung tissue were detected with Western blotting. The mRNA level of MMP-9 in lung tissue was detected with real-time fluorescence quantitative PCR. Data were processed with one-way analysis of variance (among groups) and SNK method (paired comparison).

RESULTSCompared with those of group C [respectively (2.0 ± 0.7)×10(4) /mL and 3.7 ± 0.6], the number of neutrophils and W/D of group P [respectively (10.7 ± 1.4)×10(4) /mL and 7.6 ± 0.4] were increased. The number of neutrophils in group SB203580 and group SP600125 was respectively (8.3 ± 1.1)×10(4), (7.9 ± 1.3)×10(4)/mL, with W/D respectively 6.1 ± 1.4, 6.1 ± 0.9, all of which decreased as compared with those of group P (with P values all below 0.01). Compared with those of group C, the levels of TNF-a, IL-1β, IL-6, and IL-8 of group P were increased, but decreased in group SB203580 and group SP600125 compared with that of group P, though still higher than those of group C, and the differences were statistically significant (P < 0.05 or P<0.01). Protein quantities of p-p38 and p-JNK were higher in group P (respectively 1.19 ± 0.22 and 1.43 ± 0.14) than in group C (respectively 0.76 ± 0.06 and 0.74 ± 0.05). Compared with those of group P, the protein levels of p-ERK1/2 (0.47 ± 0.05) in group PD98059, p-p38 (0.88 ± 0.07) in group SB203580, and p-JNK (0.91 ± 0.07) in group SP600125 were significantly reduced (P < 0.05 or P < 0.01). The protein and mRNA levels of MMP-9 were higher in group P (respectively 2.23 ± 0.18 and 4.93 ± 0.12) than in group C (respectively 1.26 ± 0.14 and 1.80 ± 0.03). The protein and mRNA levels of MMP-9 in group SB203580 (respectively 1.58 ± 0.14 and 2.96 ± 0.09) and group SP600125 (respectively 1.55 ± 0.30 and 3.00 ± 0.13) were lower than those in group P (P < 0.05 or P < 0.01).

CONCLUSIONSThe phosgene inhalation can activate the MAPK signaling protein pathway by increasing expressions of p-p38 and p-JNK, which lead to an up-regulation of MMP-9, and this may contribute to the phosgene inhalation-induced lung injury.

Animals ; Burns, Inhalation ; enzymology ; Cytokines ; metabolism ; Disease Models, Animal ; Flavonoids ; pharmacology ; Imidazoles ; pharmacology ; MAP Kinase Signaling System ; Male ; Matrix Metalloproteinase 9 ; metabolism ; Mitogen-Activated Protein Kinases ; metabolism ; Phosgene ; Phosphorylation ; Pyridines ; pharmacology ; Rats ; Rats, Wistar

OBJECTIVEThis study aimed to investigate the expression and role of the mitogen activated protein kinases (ERK1/2, P38, JNK) in phosgene induced lung injury in rats in vivo.

METHOD30 male wistar rats were randomized into the group as follows, Gas inhalation control group, Phosgene inhalation group, and the following groups of the inhibitors of MAPK, involving SP600125, PD98059 and SB203580, 6 animals in each group, we copy the model of phosgene-induced lung injury, used the directional flow-inhalation device, the air control group inhaled the air, and the intervention groups were given PD98059 (intraperitoneal injection), SB203580 (hypodermic injection), SP600125 (intravenous) respectively before the inhalation of phosgene. The locations and quantities of three subfamilies of MAPKs (ERK1/2, P38, JNK) and p-MAPKs (p-ERK1/2, p-P38, p-JNK) were analyzed by immunohistochemistry and Western Blot analysis respectively; The histopathological changes of lung tissues, the number of neutrophil cells and the W/D were examined.

RESULTThere were rare p-ERK1/2, p-P38 and p-JNK positive expression in alveolar and airway epithelial cells in control group. while the positive cells increased strikingly in phosgene inhalation groups, these cells involved in this process mainly included alveolar epithelial cells, air way epithelial cells, pleural mesothelial cells, infiltrative inflammatory cells, interstitium fibrocytes. After the intervention of the specific inhibitor, the positive cells decreased. As Western Blot analysis show, Protein quantities of p-P38 and p-JNK were higher in phosgene inhalation groups than those in control group, and the differences were significant (P < 0.05). Protein quantities of p-ERK1/2, p-P38 and p-JNK were lower in intervention groups than phosgene inhalation group, and the differences were significant (P < 0.05, P < 0.01). The lung injury in phosgene inhalation groups was more severer compared with the control group, the typical pathological characters of acute lung injury were discovered, the increase of the number of neutrophil cells and W/D. After the intervention of the specific inhibitor SP600125 and SB203580, the number of neutrophil cells and W/D reduced, and the differences were significant (P < 0.05, P < 0.01).

CONCLUSIONPhosgene inhalation may activate the MAPK signaling pathway, and the expression of the phosphorylation of MAPKs increased, especially the P38 ang JNK. The results may contribute to the lung injury induced by phosgene.

Animals ; Inhalation Exposure ; JNK Mitogen-Activated Protein Kinases ; metabolism ; Lung ; metabolism ; pathology ; Lung Injury ; etiology ; metabolism ; MAP Kinase Signaling System ; Male ; Mitogen-Activated Protein Kinase 3 ; metabolism ; Mitogen-Activated Protein Kinases ; metabolism ; Phosgene ; adverse effects ; Rats ; Rats, Wistar ; p38 Mitogen-Activated Protein Kinases ; metabolism

Objective To explore the diagnosis and therapy experience of vascular ring combined with tracheal compression in infants and neonates.Methods Sixteen cases(including 7 boys and 9 girls,aged 1 day to 12 months)with vascular ring combined with tracheal compression hospitalized in Guangdong General Hospital from Jun.2004 to Dec.2009 were enrolled.In these 16 children,13 cases had congenital heart malformations.All children underwent X-ray,echocardiography and spiral computed tomography examination.Nine cases received bronchoscopy study.Fifteen cases performed surgical division of vascular ring with cardiopulmonary bypass and 1 case underwent vascular ring division and tracheoplasty.Eleven cases received management of congenital heart defect simultaneously.Results Vascular ring anomalies included pulmonary artery sling in 5 children,right aortic arch-left ligmentum/aberrant left subclavian artery in 8 cases,double aortic arch in 1 case,innominate artery compression in 1 case,and pulmonary sling combined with right aortic arch-aberrant left subclavian artery in 1 case.There were 2 ring-sling complex cases in this study.The diagnosis of vascular ring were correctly made by echocardiography in 7 children and made by spiral computed tomography in all 16 cases.Two cases combined with tracheal ring died.In the follow-up study of 11 cases,5 cases were still vulnerable to wheezing.Conclusions The common presentation of tracheal compression in infants and neonates associated with vascular ring are tachypea,stridor,and dyspnea.Multi-slices spiral computed tomography is an important imaging modality.Surgical divisions of vascular ring are safe procedure in most cases and tracheal compression can be relieved by this operation.In patients with severe tracheal stenosis,tracheoplasty should be recommended.

Objective To study the association of maternal calcium supplementation and dietary calcium intake with the preterm birth so that to provide scientific basis for effective intervention of preterm birth. Methods Normal pregnant women who were followed up all through to childbirth in Gansu Provincial Maternity and Child Care Hospital were selected. Multivariate logistic regression was used to evaluate the associ-ation of calcium supplementation and intake with preterm birth. Results After confounding factors were adjus-ted, pregnant women who took calcium supplement for more than 3 months before and/or during pregnancy had the risk of preterm birth reduced by 14% which was dose-responding ( OR=0. 86, 95% CI=0. 77-0. 96, P<0. 05). Through stratifying by trimesters of pregnancy, it was found that calcium supplement in the third trimes-ter was a protective factor for preterm birth and especially significant in early and very early pregnancy ( OR=0. 75, 95% CI=0. 62-0. 92, P<0. 05). Through stratifying by dietary calcium intake, pregnant women who took dietary calcium more than 465. 55 mg/d had the risk of preterm birth significantly reduced which was shown by the reduction of preterm birth of different degrees, controlled preterm labor and spontaneous premature dilivery (OR=0. 66, 95% CI=0. 53-0. 82, P<0. 05). Conclusion Appropriate calcium supplementation or dietary calcium intake before and during pregnancy can reduce the risk of preterm birth, which is especially sig-nificant in late pregnancy.

BACKGROUND: The effect of extracellular matrix on stem cells is the focus of tissue engineering. However, there are few reports about the synthesis and secretion of extracellular matrix as well as its effects on cells. OBJECTIVE: To isolate, culture and identify rabbit bone marrow mesenchymal stem cells (BMSCs), and to explore the changes of extracellular matrix and whole structure under the intervention of ascorbic acid. METHODS: Rabbit BMSCs were isolated by differential adherent method of the bone marrow, and the expression of CD44, CD45 and CD31 was identified by flow cytometry. The BMSCs were cultured in the culture medium containing 20 mg/L ascorbic acid. Then the cell morphology, gross structure, ultrastructure, and histological changes of BMSCs were observed. The expression of extracellular matrix related genes was detected by RT-PCR. RESULTS AND CONCLUSION: Over 95% passage 2 BMSCs could express CD44, but the expression levels of CD45 and CD31 were extremely low. Intervention with ascorbic acid enhanced the proliferation of BMMSCs with unclear cell boundaries. A cell-sheet structure formed at 10-14 days after intervention. Hematoxylin-eosin staining results showed a layered cell arrangement, and Masson staining findings showed a large amount of extracellular matrix composition. Abundant endoplasmic reticula and vesicle-like structure were observed under the transmission electron microscope. RT-PCR findings showed that ascorbic acid significantly increased the expression of fibronectin mRNA in the BMSCs (P < 0.05), but slightly increased the mRNA expression of collagen type I. All these findings indicate that ascorbic acid not only increases the proliferation and transformation of rabbit BMSCs, but also promotes the synthesis and secretion of extracellular matrix, which has great potential in tissue engineering applications.

The qualitative and quantitative analysis on traditional Chinese medicine and formula components can be made by chemical and instrumental analysis methods. Of both, the instrumental analysis methods play a dominant role, including HPLC, HPLC-MS, HPLC-NMR, GC, GC-MS, biochemical and biological effect. But because traditional Chinese medicines and formula have complicated components, chemical methods are so unspecific that they shall be used less or with caution. While instrumental analysis methods are so specific that they are appropriate for analyzing complicated single component. The analysis techniques for multiple components of traditional Chinese medicines and formula focus on fingerprints, but all of these analysis techniques are limited by the pre-requisite of separation and the lack of general-purpose detectors and therefore being hard to realize the determination of all components of traditional Chinese medicines and formula. In the natural world, however, organisms identify native and alien components through specificity and non-specificity of clusters decided by antigens and antibodies. For example, components of traditional Chinese medicines are directly or indirectly synthesized into antigens and injected into animals, in order to generate specific antibodies and then collect cross reaction information of these components to specific antibodies. As for components without cross reaction, their contents shall be directly read out on the basis of the inhibition rate curve of competitive reaction for specificity of antigens and antibodies. Besides, a cross inhibition rate matrix shall be established first, and them a multiple regression linear equation between cross component concentration or concentration logarithm and inhibition rate by labeling the immunity competitive reaction between antibodies and haptens of traditional Chinese medicine and compound components, and then solved to obtain concentration of each component. The two results are combined to establish the synthetic immunity chip method for traditional Chinese medicine and formula components.
Animals ; Chemistry, Pharmaceutical ; Drugs, Chinese Herbal ; chemistry ; High-Throughput Screening Assays ; methods ; Humans ; Immunohistochemistry ; methods ; Vaccines, Synthetic ; chemistry

Production of Hepatitis E Virus capsid protein by high cell density culture in recombinant E. coli has been studied in 10L and 30L fermentors. The effects of different factors on growth and producing recombinant protein of E. coli have been studied by batch culture, such as different media, the ratio of phosphate and Magnesium sulfate. Comparison of fermentation performance for recombinant E. coli in different fed-methods culture has been investigated by fed-batch culture. The effects of inducing at different stages of growth and time of inducing on growth and producing recombinant protein, also obtained by fed-batch culture. At last, the solubility of inclusion body in different urea concentrations also has been obtained by fed-batch culture. The results show that the concentration of phosphate and Magnesium sulfate in the optimal media is 80mmol/L and 20mmol/L in batch culture respectively, that induction with 1.0mmol/L IPTG at mid log phase (about 45 OD at 600nm) is suitable for growth and recombinant protein expression, the cells were approaching stationary growth phase and the maximum cell OD at 600nm of 80 was achieved in 5h of fed-batch culture, and the expression level is 29.74%. The results also indicate that the solubility of inclusion body in 4mol/L urea solution induced at 37 degrees C reaches 14mg/mL, over 80% inclusion body was resolved. The culture process achieved in 10L fermentor could be successfully scaled up to 30L fenmentor with good reproducibility.
Bioreactors ; microbiology ; Colony Count, Microbial ; Escherichia coli ; genetics ; metabolism ; Hepatitis E virus ; genetics ; Nucleocapsid Proteins ; biosynthesis ; genetics ; Protein Engineering ; methods ; Recombinant Fusion Proteins ; biosynthesis ; genetics

Hepatitis E is a main cause of acute viral hepatitis in developing countries where it occurs as sporadic cases and in epidemics form. The causative agent, hepatitis E virus, is transmitted primarily by the fecal-oral route. The approximately 7.5 kb positive-sense single-strand RNA genome includes three open reading frames (ORFs), one of which (ORF2) is postulated to encode the major viral capsid protein (pORF2) of 660 amino acid residues. We earlier showed that a bacterially expressed peptide, designated as NE2, located from amino acid residues 394 to 606 of ORF2, was found to aggregate into homodimer to at least hexamer. To understand the interface domains within this peptide vital for dimerization and formation of major neutralizing epitopes, NE2 protein underwent terminal-truncated and site-directed mutation. The hydrophobic region, ORF2 aa597-aa602 (AVAVLA), played a key role in oligomerization. Any amino acid residue of this region replaced with glutamic acid residue, the peptide can not refold as homodimer and/or oligomer. The immunoreactivities of these mutant peptides, blotted with anti-HEV neutralizing monoclonal antibody (8C11) and convalescent human sera, show associated to the formation of homodimer. The intermolecular contact region on homodimer was investigated by chemical cross-linking of two site-directed cysteines. When the alanine on aa597 site mutated with cysteine, two different homodimers were found in SDS-PAGE analysis. One (42kD) can be disassociated with 8mol/L urea, which is postulated to form by virtue of hydrophobic interaction, and the other (60kD) falls apart with the reductant DTT present. The exact conformation, generating the cross-linking reaction of cysteines, was further investigated by induced-oxidation on monomer and hydrophobic homodimer of A597C protein with GSH/GSSG. And the results revealed, it is the conformation of hydrophobic homodimer that induces the disulfide bond come into being, instead of the one of monomer. So the aa597 site was verified to be located on interface domain of hydrophobically interacting homodimeric complex. To evaluate the biological significance of hydrophobicity of interface domain, we searched natural variations as to the region on all available databases with NCBI blast program. All variations on these amino acid residues kept higher hydrophobicity, which suggests that the hydrophobic domain is critical for the assemblage and propagation of HEV. NE2 N-terminal deletions up to aa458 had no effect on dimerization and took no exact part in formation of major neutralizing epitopes, but the fragment may act as helper for the formation of major neutralizing epitopes on NE2. Interestingly, the C-terminus aa605-aa660 of ORF2 can also act as helper instead of the N-terminus of NE2. This study suggests an interface domain of NE2 might be vital for HEV capsomer assembly and formation of major neutralizing epitopes. These results may offer clues to the rational design of recombinant anti-HEV vaccine.
Capsid Proteins ; chemistry ; Hepatitis E virus ; chemistry ; Hydrophobic and Hydrophilic Interactions ; Protein Multimerization ; Protein Structure, Tertiary ; Virus Assembly