In silico genome-wide analysis of homeodomain-leucine zipper transcription factors in Cannabis sativa L.

HD-Zip (Homeodomain-Leucine Zipper) is a family of transcription factors unique to higher plants and plays a vital role in plant growth and development. Increasing research results show that HD-Zip transcription factors are widely involved in many life processes in plants. However, the HD-Zip transcription factor for cannabis, a valuable crop, has not yet been identified. The sequence characteristics, chromosome localization, system evolution, conservative motif, gene structure, and gene expression of the HD-Zip transcription factor in the cannabis genome were systematically studied. Real-time quantitative polymerase chain reaction (qRT-PCR) was used to verify its function. The results showed that cannabis contained 33 HD-Zip gene members. The number of amino acids is 136-849aa, the isoelectric point is 4.54-9.04, and the molecular weight is 23264.32-93147.87Da. Many cis-acting elements are corresponding to hormone and abiotic stress in the HD-Zip family promoter area of cannabis. Sequencing of the transcriptome at 5 tissue sites of hemp, stems, leaves, bracts, and seeds showed similar levels of expression of 33 members of the HD-Zip gene family at 5 tissue sites. Bioinformatics results show that HD-Zip expression is tissue-specific and may be influenced by hormones and environmental factors. This lays a foundation for further research on the gene function of HD-Zip.

Effects of clinical nursing pathway on surgical site wound infection in patients undergoing acute appendicitis surgery: A meta-analysis.

This study aimed to explore the impact of clinical nursing pathway applied to acute appendicitis surgery on patients' postoperative wound infections and complications. A computerised search of PubMed, Cochrane Library, Web of Science, EMBASE, Wanfang, Chinese Biomedical Literature Database and China National Knowledge Infrastructure was conducted and supplemented by a manual search, from database inception to October 2023, to collect randomised controlled trials (RCTs) on the application of clinical nursing pathways to acute appendicitis surgery. Literature screening, data extraction and quality assessment of the included literature were carried out independently by two researchers. RevMan 5.4 software was applied for data analysis. Twenty-one RCTs with a total of 2408 patients were finally included. The analysis revealed the implementation of clinical nursing pathway could effectively reduce the incidence of wound infection (OR = 0.26, 95% CI: 0.15-0.46, p < 0.001) and postoperative complications (OR = 0.20, 95% CI: 0.15-0.27, p < 0.001), as well as shorten the hospital length of stay (MD = -3.26, 95% CI: -3.74 to -2.79, p < 0.001) and accelerated the time to first ventilations (MD = -14.85, 95% CI: -21.56 to -8.13, p < 0.001), as well as significantly improved patient satisfaction (OR = 5.52, 95% CI: 3.52-8.65, p < 0.001) in patients undergoing surgery for acute appendicitis. The application of clinical nursing pathway in acute appendicitis surgery can significantly reduce postoperative wound infection and complications, and at the same time can shorten the hospital length of stay as well as improve the satisfaction of patients.

Effect of comprehensive nursing intervention on wound pain and wound complications in patients with tonsillectomy: A meta-analysis.

To systematically evaluate the effects of comprehensive nursing interventions on wound pain and complications in patients after tonsillectomy, with a view to providing a reference basis for future post-tonsillectomy care. According to the developed literature search strategy, PubMed, Web of Science, Cochrane Library, Embase, Wanfang, China Biomedical Literature Database and China National Knowledge Infrastructure database were systematically searched, from database inception to October 2023, for randomised controlled trials (RCTs) of the application of comprehensive nursing interventions in patients undergoing tonsillectomy. Two researchers independently screened the literature, evaluated the risk of bias of the included studies and extracted data in strict accordance with the inclusion and exclusion criteria. RevMan 5.4 software was applied for data analysis. Overall, 18 RCTs involving 1954 patients were included, including 967 in the comprehensive nursing group and 987 in the conventional nursing group. The analyses revealed that compared with conventional nursing, patients who received comprehensive nursing interventions had lower postoperative wound pain scores (standardised mean difference [SMD]: -2.30, 95% confidence interval [CI]: -2.19 to -1.70, p < 0.00001), shorter hospital stays (SMD: -1.95, 95% CI: -2.39 to -1.51, p < 0.00001), incidence of postoperative haemorrhage (1.60% vs. 6.41%, odds ratio [OR]: 0.29, 95% CI: 0.12-0.70, p = 0.006) and complication rates (4.21% vs. 19.01%, OR: 0.19, 95% CI: 0.11-0.32, p < 0.00001) was lower. This study concludes as follows: comprehensive nursing intervention applied to tonsillectomy can significantly reduce patients' postoperative wound pain, shorten hospital stay, reduce postoperative bleeding and postoperative complications, which is worthy of being promoted and applied in the clinic.

Effect of Third Interstitial Fluid on Adverse Outcomes in Patients with Severe Pre-eclampsia and Twin Pregnancy: A 5-year Single-center Retrospective Study.

OBJECTIVE: This study aims to identify the effect of third interstitial fluid on adverse outcomes in twin pregnancies with severe pre-eclampsia, and explore the differences in bad ending between twins and singletons. METHODS: The present retrospective cohort study was conducted on patients with severe pre-eclampsia, who delivered in Tongji Hospital, Wuhan, China, between 2017 and 2022. The adverse outcomes in singleton and twin pregnancies with severe pre-eclampsia were initially investigated. Then, the diverse maternal and fetal consequences between singleton and twin pregnancies in patients with severe pre-eclampsia were compared after merging with the third interstitial fluid. RESULTS: A total of 709 patients were included for the present study. Among these patients, 68 patients had twin pregnancies, and 641 patients had singleton pregnancies. The rate of postpartum hemorrhage (2.81% vs. 13.24%, P<0.001), and admission rate to the Neonatal Intensive Care Unit (NICU) after birth (30.73% vs. 63.24%, P=0.011) were significantly higher in twin pregnancies. The neonatal weight of twins was statistically lower than singletons (1964.73±510.61 g vs. 2142.92±731.25 g, P=0.008). For the groups with the third interstitial fluid, the delivery week (P=0.001) and rate of admission to the NICU after birth were significantly advanced in twin pregnancy group, when compared to singleton pregnancy group (P=0.032), and the length of hospital stay was shorter (P=0.044). Furthermore, there was no statistically significant difference between the twin pregnancy group and the singletony pregnancy group without the third interstitial fluid. CONCLUSION: The maternal and fetal adverse outcomes of patients with severe pre-eclampsia increased in twin pregnancies, when compared to singleton pregnancies. Thus, when patients develop the third interstitial fluid, twin pregnancies would more likely lead to adverse fetal outcomes, when compared to singleton pregnancies, and there would be no significant difference in maternal adverse outcomes. More attention should be given to patients who merge with the third interstitial fluid.

Structural basis underlying the synergism of NADase and SLO during group A Streptococcus infection.

Group A Streptococcus (GAS) is a strict human pathogen possessing a unique pathogenic trait that utilizes the cooperative activity of NAD+-glycohydrolase (NADase) and Streptolysin O (SLO) to enhance its virulence. How NADase interacts with SLO to synergistically promote GAS cytotoxicity and intracellular survival is a long-standing question. Here, the structure and dynamic nature of the NADase/SLO complex are elucidated by X-ray crystallography and small-angle scattering, illustrating atomic details of the complex interface and functionally relevant conformations. Structure-guided studies reveal a salt-bridge interaction between NADase and SLO is important to cytotoxicity and resistance to phagocytic killing during GAS infection. Furthermore, the biological significance of the NADase/SLO complex in GAS virulence is demonstrated in a murine infection model. Overall, this work delivers the structure-functional relationship of the NADase/SLO complex and pinpoints the key interacting residues that are central to the coordinated actions of NADase and SLO in the pathogenesis of GAS infection.

The Gain-of-Function Mutation, OsSpl26, Positively Regulates Plant Immunity in Rice.

Rice spotted-leaf mutants are ideal materials to study the molecular mechanism underlying programmed cell death and disease resistance in plants. LOC_Os07g04820 has previously been identified as the candidate gene responsible for the spotted-leaf phenotype in rice Spotted-leaf 26 (Spl26) mutant. Here, we cloned and validated that LOC_Os07g04820 is the locus controlling the spotted-leaf phenotype of Spl26 by reverse functional complementation and CRISPR/Cas9-mediated knockout of the mutant allele. The recessive wild-type spl26 allele (Oryza sativa spotted-leaf 26, Osspl26) is highly conservative in grass species and encodes a putative G-type lectin S-receptor-like serine/threonine protein kinase with 444 amino acid residuals. OsSPL26 localizes to the plasma membrane and can be detected constitutively in roots, stems, leaves, sheaths and panicles. The single base substitution from T to A at position 293 leads to phenylalanine/tyrosine replacement at position 98 in the encoded protein in the mutant and induces excessive accumulation of H2O2, leading to oxidative damage to cells, and finally, formation of the spotted-leaf phenotype in Spl26. The formation of lesions not only affects the growth and development of the plants but also activates the defense response and enhances the resistance to the bacterial blight pathogen, Xanthomonas oryzae pv. oryzae. Our results indicate that the gain-of-function by the mutant allele OsSpl26 positively regulates cell death and immunity in rice.

Unraveling the Uncharacterized Domain of Carocin S2: A Ribonuclease Pectobacterium carotovorum subsp. carotovorum Bacteriocin.

Carocin S2 is a bacteriocin with a low molecular weight generated by Pectobacterium carotovorum subsp. carotovorum 3F3 strain. The caroS2K gene, which is found in the genomic DNA alongside the caroS2I gene, which codes for an immunity protein, encodes this bacteriocin. We explored the residues responsible for Carocin S2's cytotoxic or RNA-se activity using a structure-based mutagenesis approach. The minimal antibiotic functional region starts at Lys691 and ends at Arg783, according to mutational research. Two residues in the identified region, Phe760 and Ser762, however, are unable to demonstrate this activity, suggesting that these sites may interact with another domain. Small modifications in the secondary structure of mutant caroS2K were revealed by circular dichroism (CD) spectroscopy and intrinsic tryptophan fluorescence (ITF), showing ribosomal RNA cleavage in the active site. A co-immunoprecipitation test indicated that the immunity protein CaroS2I binds to CaroS2K's C-terminus, while a region under the uncharacterized Domain III inhibits association of N-terminally truncated CaroS2K from interacting with CaroS2I. Carocin S2, a ribosomal ribonuclease bacteriocin, is the first to be identified with a domain III that encodes the cytotoxic residues as well as the binding sites between its immunity and killer proteins.

A Novel Allele Encoding 7-Hydroxymethyl Chlorophyll a Reductase Confers Bacterial Blight Resistance in Rice.

Rice spotted leaf mutants are helpful to investigate programmed cell death (PCD) and defense response pathways in plants. Using a map-based cloning strategy, we characterized novel rice spotted leaf mutation splHM143 that encodes a 7-hydroxymethyl chlorophyll a reductase (OsHCAR). The wild-type (WT) allele could rescue the mutant phenotype, as evidenced by complementation analysis. OsHCAR was constitutively expressed at all rice tissues tested and its expression products localized to chloroplasts. The mutant exhibited PCD and leaf senescence with increased H2O2 (hydrogen peroxide) accumulation, increased of ROS (reactive oxygen species) scavenging enzymes activities and TUNEL (terminal deoxyribonucleotidyl transferase-mediated dUTP nick-end labeling) -positive nuclei, upregulation of PCD related genes, decreased chlorophyll (Chl) contents, downregulation of photosynthesis-related genes, and upregulation of senescence-associated genes. Besides, the mutant exhibited enhanced bacterial blight resistance with significant upregulation of defense response genes. Knockout lines of OsHCAR exhibited spotted leaf phenotype, cell death, leaf senescence, and showed increased resistance to the bacterial pathogen Xanthomonas oryzae pv. oryzae (Xoo) coupled with upregulation of five pathogenesis-related marker genes. The overexpression of OsHCAR resulted in increased susceptibility to Xoo with decreased expression of pathogenesis-related marker genes. Altogether, our findings revealed that OsHCAR is involved in regulating cell death and defense response against bacterial blight pathogen in rice.

PREMATURE SENESCENCE LEAF 50 Promotes Heat Stress Tolerance in Rice (Oryza sativa L.).

BACKGROUND: Heat stress is a major environmental factor that could induce premature leaf senescence in plants. So far, a few rice premature senescent leaf mutants have been reported to involve in heat tolerance. FINDINGS: We identified a premature senescence leaf 50 (psl50) mutant that exhibited a higher heat susceptibility with decreased survival rate, over-accumulated hydrogen peroxide (H2O2) content and increased cell death under heat stress compared with the wild-type. The causal gene PREMATURE SENESCENCE LEAF 50 (PSL50) was isolated by using initial map-based resequencing (IMBR) approach, and we found that PSL50 promoted heat tolerance probably by acting as a modulator of H2O2 signaling in response to heat stress in rice (Oryza sativa L.). CONCLUSIONS: PSL50 negatively regulates heat-induced premature leaf senescence in rice.

OsNAC109 regulates senescence, growth and development by altering the expression of senescence- and phytohormone-associated genes in rice.

KEY MESSAGE: We demonstrate that OsNAC109 regulates senescence, growth and development via binding to the cis-element CNTCSSNNSCAVG and altering the expression of multiple senescence- and hormone-associated genes in rice. The NAC family is one of the largest transcripton factor families in plants and plays an essential role in plant development, leaf senescence and responses to biotic/abiotic stresses through modulating the expression of numerous genes. Here, we isolated and characterized a novel yellow leaf 3 (yl3) mutant exhibiting arrested-growth, increased accumulation of reactive oxygen species (ROS), decreased level of soluble proteins, increased level of malondialdehyde (MDA), reduced activities of ROS scavenging enzymes, altered expression of photosynthesis and senescence/hormone-associated genes. The yellow leaf and arrested-growth trait was controlled by a single recessive gene located to chromosome 9. A single nucleotide substitution was detected in the mutant allele leading to premature termination of its coding protein. Genetic complementation could rescue the mutant phenotype while the YL3 knockout lines displayed similar phenotype to WT. YL3 was expressed in all tissues tested and predicted to encode a transcriptional factor OsNAC109 which localizes to the nucleus. It was confirmed that OsNAC109 could directly regulate the expression of OsNAP, OsNYC3, OsEATB, OsAMTR1, OsZFP185, OsMPS and OsGA2ox3 by targeting to the highly conserved cis-element CNTCSSNNSCAVG except OsSAMS1. Our results demonstrated that OsNAC109 is essential to rice leaf senescence, growth and development through regulating the expression of senescence- and phytohormone-associated genes in rice.

Characterization of a novel allele encoding pheophorbide a oxygenase in rice.

We identified a rapid cell death 2 (rcd2) mutant from an indica cultivar Zhongjian100 mutant bank. The red-brown lesions appeared firstly on young seedling leaves, then gradually merged and the leaves completely withered at the late tillering stage. rcd2 displayed apparent cell death at/around the lesions, accumulation of superoxide anion (O2-) and disturbed ROS scavenging system, impaired photosynthetic capacity with significantly reduced chlorophyll content. The lesion formation was controlled by a single recessive nuclear gene and induced by natural light as well as mechanical wounding. A single base mutation (A1726T) at the 6th exon of OsMH_03G0040800 resulted in I576F substitution in the encoding protein, pheophorbide a oxygenase (PAO). Functional complementation could rescue the mutant phenotype and PAO-knockout lines exhibited the similar phenotype to rcd2. The activity of PAO decreased significantly while the content of PAO substrate, pheophorbide a, increased apparently in rcd2. The expression of chlorophyll synthesis/degradation-related genes and the contents of metabolic intermediates were largely changed. Furthermore, the level of chlorophyllide a, the product of chlorophyllase, increased significantly, indicating chlorophyllase might play a role in chlorophyll degradation in rice. Our results suggested that the I576F substitution disrupted PAO function, leading to O2- accumulation and chlorophyll degradation breakdown in rice.

Chloroplast SRP54s are Essential for Chloroplast Development in Rice.

BACKGROUND: The chloroplast signal recognition particle 54 (cpSRP54) is known for targeting the light-harvesting complex proteins to thylakoids and plays a critical role for chloroplast development in Arabidopsis, but little is known in rice. Here, we reported two homologous cpSRP54s that affect chloroplast development and plant survival in rice. RESULTS: Two rice cpSRP54 homologues, OscpSRP54a and OscpSRP54b, were identified in present study. The defective OscpSRP54a (LOC_Os11g05552) was responsible for the pale green leaf phenotype of the viable pale green leaf 14 (pgl14) mutant. A single nucleotide substitution from G to A at the position 278, the first intron splicing site, was detected in LOC_Os11g05552 in pgl14. The wild type allele could rescue the mutant phenotype. Knockout lines of OscpSRP54b (LOC_Os11g05556) exhibited similar pale green phenotype to pgl14 with reduced chlorophyll contents and impaired chloroplast development, but showed apparently arrested-growth and died within 3 weeks. Both OscpSRP54a and OscpSRP54b were constitutively expressed mainly in shoots and leaves at the vegetative growth stage. Subcellular location indicated that both OscpSRP54a and OscpSRP54b were chloroplast-localized. Both OscpSRP54a and OscpSRP54b were able to interact with OscpSRP43, respectively. The transcript level of OscpSRP43 was significantly reduced while the transcript level of OscpSRP54b was apparently increased in pgl14. In contrast, the transcript levels of OscpSRP54a, OscpSRP43 and OscpSRP54b were all significantly decreased in OscpSRP54b knockout lines. CONCLUSION: Our study demonstrated that both OscpSRP54a and OscpSRP54b were essential for normal chloroplast development by interacting with OscpSRP43 in rice. OscpSRP54a and OscpSRP54b might play distinct roles in transporting different chloroplast proteins into thylakoids through cpSRP-mediated pathway.

The OsABCI7 Transporter Interacts with OsHCF222 to Stabilize the Thylakoid Membrane in Rice.

The thylakoid membrane is a highly complex membrane system in plants and plays crucial roles in the biogenesis of the photosynthetic apparatus and plant development. However, the genetic factors involved in chloroplast development and its relationship with intracellular metabolites are largely unknown. Here, a rice (Oryza sativa) chlorotic and necrotic leaf1 (cnl1) mutant was identified and map-based cloning revealed that a single base substitution followed by a 6-bp deletion in the ATP-binding cassette transporter I family member7 (OsABCI7) resulted in chlorotic and necrotic leaves with thylakoid membrane degradation, chlorophyll breakdown, photosynthesis impairment, and cell death in cnl1 Furthermore, the expression of OsABCI7 was inducible under lower temperatures, which severely affected cnl1 chloroplast development, and etiolated cnl1 seedlings were unable to recover to a normal green state under light conditions. Functional complementation and overexpression showed that OsABCI7 could rescue the cnl1 chlorotic and necrotic phenotype. OsABCI7 interacted with HIGH CHLOROPHYLL FLUORESCENCE222 (OsHCF222) to regulate cellular reactive oxygen species (ROS) homeostasis for thylakoid membrane stability. OsABCI7 localized to thylakoid membranes, while OsHCF222 targeted to endoplasmic reticulum and chloroplasts. Exogenous application of ascorbic acid eased the yellowish leaf phenotype by increasing chlorophyll content and alleviating ROS stress in cnl1 Unlike cnl1, the CRISPR/Cas9-mediated OsHCF222 knockout lines showed chlorotic leaves but were seedling lethal. Our results provide insight into the functions of ABC transporters in rice, especially within the relationship between ROS homeostasis and stability of thylakoid membranes.

[Encircling needling is superior to "Bangci"(focal center-side needling) in promoting wound healing in diabetic mice].

OBJECTIVE: To compare the therapeutic effects of "Bangci"(focal center-side needling) and encircling needling in promoting skin wound healing and local blood perfusion in diabetic mice. METHODS: Thirty-two male C57BL/6N mice were randomized into normal, diabetic model, focal center-side needling and encircling needling groups (n=8 in each group). The skin wound model was prepared by cutting a piece of full-thickness skin at the mouse's back by using a puncher. One hour after modeling, two acupuncture needles were respectively inserted into the center of the wound and the spot at the normal skin about 0.5 cm away from the edge of the wound for mice of the focal center-side needling group, followed by EA (0.5 mA, 0.5 Hz) for 30 min. For mice of the encircling needling group, 4 acupuncture needles were respectively inserted into the upper, lower, left and right normal marginal skin around the wound, followed by EA stimulation with the same parameters as those of the center-side needling group. The wound conditions, diameter and area of the wound were monitored, and the wound blood perfusion volume was measured by using a laser speckle flowmeter. RESULTS: The wound shrinkage rates were significantly higher at the time-points of 3, 5, 7, 9 and 11 d after modeling in both focal center-side needling and encircling needling groups than in the model group (P<0.05), and on day 3, 5, 7 and 9 in the encircling needling group than in the focal center-side needling group (P<0.05). The wound healing time was obviously earlier in both focal center-side needling and encircling needling groups than in the model group (P<0.05), and in the encircling needling group than in the focal center-side needling group (P<0.05). Following modeling, the volume of wound blood perfusion was considerably higher from day 1 to 9 and markedly lower on day 11 in the model group than in the normal group (P<0.01), and after the intervention, the blood perfusion volume was considerably decreased on day 3, 5, 7 and 9 in both the focal center-side needling and encircling needling groups(P<0.05, P<0.01), and obviously increased on day 11 in the encircling needling group relevant to the model group (P<0.01).Comparison between post- and pre-EA stimulation showed that the immediate blood perfusion volume was significantly increased from day 1 to 11 after EA stimulation in both the focal center-side needling and encircling needling groups (P<0.01, P<0.05). The therapeutic effect of the encircling needling group was significantly superior to that of the focal center-side needling group in lowering blood perfusion volume from day 3 to 7, and in increasing blood perfusion volume on day 9 and 11 (P<0.01). Under the naked eyes, the conditions of exudation and inflammatory reaction, and the scar and granulation tissue were relatively milder and better respectively in both the center-side needling and encircling needling groups than in the model group. CONCLUSION: Both focal center-side needling and encircling needling can promote the skin wound healing by increasing the blood perfusion in diabetic mice, and the therapeutic effect of the encircling needling method was significantly superior to that of the focal center-side needling method.

Experience of Clinical Management for Pregnant Women and Newborns with Novel Coronavirus Pneumonia in Tongji Hospital, China.

Based on the New Diagnosis and Treatment Scheme for Novel Coronavirus Infected Pneumonia (Trial Edition 5), combined with our current clinical treatment experience, we recently proposed a revision of the first edition of "Guidance for maternal and fetal management during pneumonia epidemics of novel coronavirus infection in the Wuhan Tongji Hospital". This article focused on the issues of greatest concern of pregnant women including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection diagnostic criteria, inspection precautions, drug treatment options, indications and methods of termination of pregnancy, postpartum fever, breastfeeding considerations, mode of mother-to-child transmission, neonatal isolation and advice on neonatal nursing, to provide valuable experience for better management of SARS-CoV-2 infection in pregnant women and newborns.

Characterization of a Novel Rice Dynamic Narrow-Rolled Leaf Mutant with Deficiencies in Aromatic Amino Acids.

The leaf blade is the main photosynthetic organ and its morphology is related to light energy capture and conversion efficiency. We isolated a novel rice Dynamic Narrow-Rolled Leaf 1 (dnrl1) mutant showing reduced width of leaf blades, rolled leaves and lower chlorophyll content. The narrow-rolled leaf phenotype resulted from the reduced number of small longitudinal veins per leaf, smaller size and irregular arrangement of bulliform cells compared with the wild-type. DNRL1 was mapped to chromosome 7 and encoded a putative 3-deoxy-7-phosphoheptulonate synthase (DAHPS) which catalyzes the conversion of phosphoenolpyruvate and D-erythrose 4-phosphate to DAHP and phosphate. Sequence analysis revealed that a single base substitution (T-A) was detected in dnrl1, leading to a single amino acid change (L376H) in the coding protein. The mutation led to a lower expression level of DNRL1 as well as the lower activity of DAHPS in the mutant compared with the wild type. Genetic complementation and over-expression of DNRL1 could rescue the narrow-rolled phenotype. DNRL1 was constitutively expressed in all tested organs and exhibited different expression patterns from other narrow-rolled leaf genes. DNRL1-GFP located to chloroplasts. The lower level of chlorophyll in dnrl1 was associated with the downregulation of the genes responsible for chlorophyll biosynthesis and photosynthesis. Furthermore, dnrl1 showed significantly reduced levels of aromatic amino acids including Trp, Phe and Tyr. We conclude that OsDAHPS, encoded by DNRL1, plays a critical role in leaf morphogenesis by mediating the biosynthesis of amino acids in rice.

Circ_0063517 acts as ceRNA, targeting the miR-31-5p-ETBR axis to regulate angiogenesis of vascular endothelial cells in preeclampsia.

AIMS: Accumulated evidence indicates that the dysregulation of circular RNAs (circRNAs) plays pivotal roles in many human diseases including preeclampsia (PE). Circ_0063517 has been verified to be down-regulated in PE. But the role of circ_0063517 in PE is still unclear. This research aims to probe into the effect of circ_0063517 on angiogenesis in PE development. MAIN METHODS: The expression of circ_0063517, endothelin receptor type B (ETBR) and miR-31-5p was assessed by quantitative reverse transcription polymerase chain reaction (RT-qPCR). MTT assay, colony formation assay, scratch assay, transwell assay, and tube formation assay were performed to detect proliferation, migration, and angiogenesis, respectively. Dual luciferase reporter system and RNA immunoprecipitation (RIP) assay were carried out to determine the interaction between miR-31-5p and circ_0063517(or ETBR). ETBR, VEGFRA, and VEGFR2 levels were detected by western blot analysis. The effect of circ_0063517 and ETBR on angiogenesis was evaluated in N-nitro-L-arginine methyl ester hydrochloride (L-NAME)-induced PE in vivo. KEY FINDINGS: The levels of circ_0063517 and ETBR were down-regulated in the placenta tissue of PE patients. Conversely, the level of miR-31-5p was up-regulated in PE. Overexpression of circ_0063517 or knockdown of miR-31-5p facilitated growth, migration, and angiogenesis of vascular endothelial cells. Circ_0063517 knockdown-induced repression of the expression of ETBR, VEGFA, and VEGFR2 was partly counteracted by ETBR overexpression. Mechanistically, circ_0063517 sponged miR-31-5p to regulate ETBR expression. Finally, circ_0063517 promoted angiogenesis via enhancing ETBR expression in PE in vivo. SIGNIFICANCE: Our findings suggest that circ_0063517-miR-31-5p-ETBR axis regulates angiogenesis during the pathological process of PE.

HIF-1α regulates angiogenesis via Notch1/STAT3/ETBR pathway in trophoblastic cells.

Background: Preeclampsia is a pregnancy-related complication and the major cause to maternal and fetal mortality. Despite extensive studies, the pathogenesis of this disease still remains unknown. Here we explored the roles of HIF-1α and Notch1/ETBR in preeclampsia.Methods: Immunohistochemistry, RT-qPCR and western blot were used to measure levels of Notch1 and ETBR in placentas of preeclampsia patients. Transwell invasion assay and in vitro Matrigel assay were used to test the functions of Notch1, HIF-1α and ETBR in invasion and angiogenesis of trophoblast cells. In addition, we used reduced uterine perfusion pressure (RUPP) rat model to study preeclampsia in vivo.Results: We found that Notch1 and ETBR were down-regulated in the placenta of patients with preeclampsia. Hypoxia promoted invasion and angiogenesis of trophoblast cells, and up-regulated expressions of HIF-1α, Notch1/ETBR. Overexpression of Notch1 facilitated invasion and angiogenesis of trophoblast cells while HIF-1α inhibitor suppressed. Furthermore, Notch1 or ETBR could promote angiogenesis of trophoblast cells in RUPP rats.Conclusions: Our study reveals that HIF-1α and Notch1/ETBR play important roles in preeclampsia. Hypoxia-induced HIF-1αregulated Notch1/ETBR signaling, thereby modulating invasion and angiogenesis of trophoblast cells. These results shed light on molecular mechanisms of preeclampsia and provide potential targets for preeclampsia therapy.