[Circular RNA expression profiles and circRNA-miRNA-mRNA crosstalk in pre-eclamptic placenta]

Objective: To identify the expression profile of circular RNA (circRNA) in placenta of pre-eclampsia (PE) pregnant women by high-throughput sequencing, and to construct the circRNA-microRNA (miRNA)-messenger RNA (mRNA) interaction network, so as to reveal the related pathways and regulatory mechanisms of PE. Methods: The clinical data and placentas of 42 women with PE (PE group) and 30 normal pregnant women (control group) who delivered in West China Second University Hospital from November 2019 to June 2021 were collected. (1) High-throughput sequencing was used to establish the differentially expressed circRNA profiles in placental tissues of 5 pairs of PE group and the control group. (2) Real-time quantitative PCR (qRT-PCR) was used to verify the expression levels of 6 differentially expressed circRNAs in placental tissues of PE group and control group. (3) Bioinformatics analysis was used to predict the target miRNA and analyze the co-expressed mRNA to construct a competitive endogenous RNA (ceRNA) network. The differentially expressed circRNAs were analyzed by Gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) pathways. (4) Logistic regression analysis, Pearson correlation and Kendall's tau-b correlation analysis were used to test the correlation between the three differentially expressed circRNAs and the risk of PE and clinical characteristics. (5) circRNA_05393 was selected for subsequent functional study. Small interfering RNA (siRNA) and overexpression plasmid were used to knock down or increase the expression level of circRNA_05393 in trophoblast cell line HTR-8/SVneo cells, respectively. Transwell assay was used to detect the migration and invasion ability of the trophoblasts in vitro. Cell counting kit-8 assay was used to detect the proliferation ability of the trophoblasts. Results: (1) Seventy-two differentially expressed circRNAs were identified by high-throughput sequencing, of which 35 were up-regulated and 37 were down-regulated. (2) qRT-PCR showed that compared with the control group, circRNA_00673 (1.306±0.168 vs 2.059±0.242; t=2.356, P=0.021) and circRNA_07796 (1.275±0.232 vs 1.954±0.230; t=2.018, P=0.047) were significantly increased, while circRNA_05393 (1.846±0.377 vs 0.790±0.094; t=3.138, P=0.002) was significantly decreased. (3) The circRNA-miRNA-mRNA interaction network contained 3 circRNAs, 8 miRNAs and 53 mRNAs. GO functional annotation analysis showed that the biological process was mainly enriched in iron ion homeostasis, membrane depolarization during action potential and neuronal action potential. In terms of cellular components, they were mainly enriched in cytoskeleton and membrane components. In terms of molecular function, they were mainly enriched in the activity of voltage-gated sodium channel and basic amino acid transmembrane transporter. KEGG pathway enrichment analysis showed that mRNAs in the interaction network were mainly enriched in complement and coagulation cascade, glycine, serine and threonine metabolism, p53 signaling pathway and peroxisome proliferators-activated receptors (PPAR) signaling pathway. (4) Logistic regression analysis showed that down-regulation of circRNA_05393 expression was a risk factor for PE (OR=0.044, 95%CI: 0.003-0.596; P=0.019). Correlation analysis showed that circRNA_05393 was significantly correlated with systolic blood pressure and diastolic blood pressure in PE pregnant women (both P<0.05). (5) Knock down or overexpression of circRNA_05393 significantly reduced or increased the migration and invasion abilities of HTR-8/SVneo cells (all P<0.05), but had no significant effect on the ability of tube formation and proliferation (all P>0.05). Conclusions: The construction of circRNA expression profile in placenta and the exploration of circRNA-miRNA-mRNA interaction network provide the possibility to reveal the regulatory mechanism of specific circRNA involved in PE. Inhibition of circRNA_05393 may induce the progression of PE by reducing the migration and invasion of trophoblasts.

Research Note: Effects of polysaccharide-enriched Acanthopanax senticosus extract on growth performance, immune function, antioxidation, and ileal microbial populations in broiler chickens

Acanthopanax senticosus (AS) is a well-known, highly effective traditional Chinese herbal medicine. Polysaccharides extracted from AS (ASPS) have multiple pharmacologic and biological activities with potential use as additives in broiler chicken feed. This trial evaluated the effects of dietary ASPS on growth performance, immune function, antioxidation, and ileal microbial populations in broiler chickens. A total of 240 1-day-old Arbor Acres male broiler chicks were randomly divided into 4 groups, with 10 replicates of 6 chicks and fed a corn- and soybean-based diet supplemented with 0, 1, 2, or 4 g/kg ASPS. Compared with the control group, supplementation with 1 g/kg ASPS increased ADG and ADFI in the finisher and overall periods and decreased the feed conversion ratio in the finisher period (both P < 0.05). Serum IgA and IgM were significantly increased by supplementation with 1 and 2 g/kg of ASPS (P < 0.05). Superoxide dismutase and glutathione peroxidase activities were increased and malondialdehyde concentration was decreased in birds fed ASPS-supplemented diets compared with those in the control group (P < 0.05). Polysaccharides extracted from AS supplementation increased Lactobacillus and decreased Escherichia coli and Salmonella counts in the ileal contents compared with the control diet (both P < 0.05). The results show that dietary ASPS improved growth performance, immune status, and antioxidant capacity and stimulated the growth of beneficial gut bacteria in broiler chickens. In conclusion, ASPS was effective as a natural additive in broiler chicken feed; 1 g/kg can be considered as the optimum dosage.

[Clinical analysis of two cases of imported children Zika virus infection in China]

OBJECTIVE

To analyze the clinical characteristics, outcome and diagnosis of two cases of imported children Zika virus infection in China.

METHOD

A retrospective analysis was performed on clinical characteristics, treatment and outcome of two cases of imported children with Zika virus infection in February 2016 in Enping People's Hospital of Guangdong.

RESULT

Two cases of children with imported Zika virus infection resided in an affected area of Venezuela, 8-year-old girl and her 6 year-old brother. The main findings on physical examination included the following manifestations: fever, rash, and conjunctivitis. The rash was first limited to the abdomen, but extended to the torso, neck and face, and faded after 3-4 d. The total number of white blood cells was not high and liver function was normal. The diagnosis of two cases of Zika virus infection was confirmed by the expert group of Guangdong Provincial Center for Disease Control and Prevention, according to the epidemiological history, clinical manifestations and Zika virus nucleic acid detection results.Treatment of Zika virus infection involves supportive care. Two Zika virus infection children had a relatively benign outcome.

CONCLUSION

At present, Zika virus infection in children is an imported disease in China. No specific therapy is available for this disease. Information on long-term outcomes among infants and children with Zika virus disease is limited, routine pediatric care is advised for these infants and children.

Increased expression of high mobility group box 1 (HMGB1) in the cytoplasm of placental syncytiotrophoblast from preeclamptic placentae

BACKGROUND

Preeclampsia is a pregnancy-specific disorder characterised by an inappropriate maternal inflammatory response during pregnancy. High mobility group box 1 (HMGB1) was originally characterised as a nuclear protein but when released into the extracellular environment following necrotic cell death, it is proinflammatory. HMGB1 is expressed in the syncytiotrophoblast of human placenta. Higher levels of uric acid are reported in preeclampsia. The aim of this study was to investigate whether the expression of HMGB1differed between early onset and late onset preeclampsia or severe and mild preeclampsia and whether its expression correlated with the levels of uric acid.

METHODS

74 preeclamptic placentae and 110 normotensive placentae were included in this study. The levels of uric acid in women with preeclampsia were measured. The expression of HMGB1 in preeclamptic placentae or in first trimester and term placentae that had been treated with uric acid was measured.

RESULTS

HMGB1 was expressed predominantly in the syncytiotrophoblast of the placenta and the expression of HMGB1 in the cytoplasm of the syncytiotrophoblast was significantly increased in both severe preeclampsia and early onset preeclampsia compared to normotensive pregnancies. The circulating levels of uric acid were significantly increased in preeclampsia and correlated with the expression of HMGB1. Increased levels of HMGB1 were significantly correlated with the severity and the time of onset of preeclampsia, but pathologic levels of uric acid did not increase the expression of HMGB1.

CONCLUSION

Our data provides a better understanding of the function of HMGB1, a danger molecule in the pathogenesis of preeclampsia.

Cardiomyocyte-specific loss of diacylglycerol acyltransferase 1 (DGAT1) reproduces the abnormalities in lipids found in severe heart failure

Diacylglycerol acyltransferase 1 (DGAT1) catalyzes the final step in triglyceride synthesis, the conversion of diacylglycerol (DAG) to triglyceride. Dgat1(-/-) mice exhibit a number of beneficial metabolic effects including reduced obesity and improved insulin sensitivity and no known cardiac dysfunction. In contrast, failing human hearts have severely reduced DGAT1 expression associated with accumulation of DAGs and ceramides. To test whether DGAT1 loss alone affects heart function, we created cardiomyocyte-specific DGAT1 knock-out (hDgat1(-/-)) mice. hDgat1(-/-) mouse hearts had 95% increased DAG and 85% increased ceramides compared with floxed controls. 50% of these mice died by 9 months of age. The heart failure marker brain natriuretic peptide increased 5-fold in hDgat1(-/-) hearts, and fractional shortening (FS) was reduced. This was associated with increased expression of peroxisome proliferator-activated receptor α and cluster of differentiation 36. We crossed hDgat1(-/-) mice with previously described enterocyte-specific Dgat1 knock-out mice (hiDgat1(-/-)). This corrected the early mortality, improved FS, and reduced cardiac ceramide and DAG content. Treatment of hDgat1(-/-) mice with the glucagon-like peptide 1 receptor agonist exenatide also improved FS and reduced heart DAG and ceramide content. Increased fatty acid uptake into hDgat1(-/-) hearts was normalized by exenatide. Reduced activation of protein kinase Cα (PKCα), which is increased by DAG and ceramides, paralleled the reductions in these lipids. Our mouse studies show that loss of DGAT1 reproduces the lipid abnormalities seen in severe human heart failure.

A large-scale gene discovery for the red palm weevil Rhynchophorus ferrugineus (Coleoptera: Curculionidae)

The red palm weevil (RPW; Rhynchophorus ferrugineus) is a devastating pest of palms, prevalent in the Middle East as well as many other regions of the world. Here, we report a large-scale de novo complementary DNA (cDNA) sequencing effort that acquired ∼5 million reads and assembled them into 26 765 contigs from 12 libraries made from samples of different RPW developmental stages based on the Roche/454 GS FLX platform. We annotated these contigs based on the publically available known insect genes and the Tribolium castaneum genome assembly. We find that over 80% of coding sequences (CDS) from the RPW contigs have high-identity homologs to known proteins with complete CDS. Gene expression analysis shows that the pupa and larval stages have the highest and lowest expression levels, respectively. In addition, we also identified more than 60 000 single nucleotide polymorphisms and 1 200 simple sequence repeat markers. This study provides the first large-scale cDNA dataset for RPW, a much-needed resource for future molecular studies.

Heat shock protein 27: a potential biomarker of peritoneal metastasis in epithelial ovarian cancer?

Ovarian cancer is the major gynaecologic malignancy and the leading cause of death in gynaecological cancer. Heat shock proteins (HSPs) are highly expressed in many malignant cancers and involved in metastasis including ovarian cancer. The early detection of peritoneal metastases in epithelial ovarian cancer may be more important in clinical care. HSP27, a small heat shock protein, is correlated with peritoneal metastases in epithelial ovarian cancer tissues. In this study, we investigated whether the levels of total HSP27 were detectable in serum and whether it could be a predictive biomarker for peritoneal metastases in epithelial ovarian cancer. Serum samples from 48 patients with epithelial ovarian cancer, 35 patients with benign ovarian tumours and 24 healthy women were included in this study. The serum levels of total HSP27 were measured by enzyme-linked immunosorbent assay (ELISA). There was no difference in the serum levels of total HSP27 between women with benign ovarian tumours and healthy women. However, the serum levels of total HSP27 were significantly increased in patients with epithelial ovarian cancer. The increased serum levels of total HSP27 were only seen in patients with peritoneal metastases. Furthermore, increased serum levels of total HSP27 were significantly reduced after the combination chemotherapies in patients with peritoneal metastases. These data suggest that circulating HSP27 levels were increased in epithelial ovarian cancer and correlated with peritoneal metastases. The measurement of serum HSP27 levels may be used as a potential additional indicator for peritoneal metastases in epithelial ovarian cancer and response to treatment.

Exogenous abscisic acid increases antioxidant enzymes and related gene expression in pepper (Capsicum annuum) leaves subjected to chilling stress

To elucidate how physiological and biochemical mechanisms of chilling stress are regulated by abscisic acid (ABA) pretreatment, pepper variety (cv. 'P70') seedlings were pretreated with 0.57 mM ABA for 72 h and then subjected to chilling stress at 10°/6°C (day/night). Chilling stress caused severe necrotic lesions on the leaves and increased malondialdehyde and H(2)O(2) levels. Activities of monodehydroascorbate reductase (DHAR), dehydroascorbate reductase, glutathione reductase, guaiacol peroxidase, ascorbate peroxidase, ascorbate, and glutathione increased due to chilling stress during the 72 h, while superoxide dismutase and catalase activities decreased during 24 h, suggesting that chilling stress activates the AsA-GSH cycle under catalase deactivation in pepper leaves. ABA pretreatment induced significant increases in the above-mentioned enzyme activities and progressive decreases in ascorbate and glutathione levels. On the other hand, ABA-pretreated seedlings under chilling stress increased superoxide dismutase and guaiacol peroxidase activities and lowered concentrations of other antioxidants compared with untreated chilling-stressed plants. These seedlings showed concomitant decreases in foliage damage symptoms, and levels of malondialdehyde and H(2)O(2). Induction of Mn-SOD and POD was observed in chilling-stressed plants treated with ABA. The expression of DHAR1 and DHAR2 was altered by chilling stress, but it was higher in the presence than in the absence of ABA at 24 h. Overall, the results indicate that exogenous application of ABA increases tolerance of plants to chilling-induced oxidative damage, mainly by enhancing superoxide dismutase and guaiacol peroxidase activities and related gene expression.

A central role for chromosome breakage in gene amplification, deletion formation, and amplicon integration

A CHO cell line with a single copy of the DHFR locus on chromosome Z2 was used to analyze the structure of the amplification target and products subsequent to the initial amplification event. Dramatic diversity in the number and cytogenetic characteristics of DHFR amplicons was observed as soon as eight to nine cell doublings following the initial event. Two amplicon classes were noted at this early time: Small extrachromosomal elements and closely spaced chromosomal amplicons were detected in 30-40% of metaphases in six of nine clones, whereas three of nine clones contained huge amplicons spanning greater than 50 megabases. In contrast, the incidence of metaphases containing extrachromosomal amplicons fell to 1-2% in cells analyzed at 30-35 cell doublings, and most amplicons localized to rearranged or broken derivatives of chromosome Z2 at this time. Breakage of the Z2 chromosome near the DHFR gene, and deletion of the DHFR gene and flanking DNA was also observed in cells that had undergone the amplification process. To account for these diverse cytogenetic and molecular consequences of gene amplification, we propose that chromosome breakage plays a central role in the amplification process by (1) generating intermediates that are initially acentric and lead to copy number increase primarily by unequal segregation, (2) creating atelomeric ends that are either incompletely replicated or resected by exonucleases to generate deletions, and (3) producing recombinogenic ends that provide preferred sites for amplicon relocalization.

[Fibronectin in gastrointestinal tumors and its relation to biological characteristics of tumor]

Through immunohistochemical technique, distribution of FN in normal mucosa, benign and malignant tumors of human gastrointestinal tract were studied. In normal and adenoma tissues, FN was found in both basement membrane (BN) and interstitial tissue. While in cancer tissue, there was a consistent decrease of BM FN content around the tumor nests particularly more apparently in cases of invading carcinoma. Statistical analysis showed that the reduction of BM FN was correlated with the degree of tumor dedifferentiation but not with the incidence of regional metastases. No association was noticed between the stroma FN and tumor behaviors. Since small blood vessels were usually delineated clearly by the staining for FN, FN might be considered as a marker in identifying the invasion of blood vessel wall by tumor cells. It is suggested that lack of BM FN in tumor tissues might be mainly due to decrease of FN synthesis by the tumor cells.