Enhanced AMPAR-dependent synaptic transmission by S-nitrosylation in the vmPFC contributes to chronic inflammatory pain-induced persistent anxiety in mice.

Chronic pain patients often have anxiety disorders, and some of them suffer from anxiety even after analgesic administration. In this study, we investigated the role of AMPAR-mediated synaptic transmission in the ventromedial prefrontal cortex (vmPFC) in chronic pain-induced persistent anxiety in mice and explored potential drug targets. Chronic inflammatory pain was induced in mice by bilateral injection of complete Freund's adjuvant (CFA) into the planta of the hind paws; anxiety-like behaviours were assessed with behavioural tests; S-nitrosylation and AMPAR-mediated synaptic transmission were examined using biochemical assays and electrophysiological recordings, respectively. We found that CFA induced persistent upregulation of AMPAR membrane expression and function in the vmPFC of anxious mice but not in the vmPFC of non-anxious mice. The anxious mice exhibited higher S-nitrosylation of stargazin (an AMPAR-interacting protein) in the vmPFC. Inhibition of S-nitrosylation by bilaterally infusing an exogenous stargazin (C302S) mutant into the vmPFC rescued the surface expression of GluA1 and AMPAR-mediated synaptic transmission as well as the anxiety-like behaviours in CFA-injected mice, even after ibuprofen treatment. Moreover, administration of ZL006, a small molecular inhibitor disrupting the interaction of nNOS and PSD-95 (20 mg·kg-1·d-1, for 5 days, i.p.), significantly reduced nitric oxide production and S-nitrosylation of AMPAR-interacting proteins in the vmPFC, resulting in anxiolytic-like effects in anxious mice after ibuprofen treatment. We conclude that S-nitrosylation is necessary for AMPAR trafficking and function in the vmPFC under chronic inflammatory pain-induced persistent anxiety conditions, and nNOS-PSD-95 inhibitors could be potential anxiolytics specific for chronic inflammatory pain-induced persistent anxiety after analgesic treatment.

Prediction for pathological and immunohistochemical characteristics of triple-negative invasive breast carcinomas: the performance comparison between quantitative and qualitative sonographic feature analysis.

OBJECTIVE: Sonographic features are associated with pathological and immunohistochemical characteristics of triple-negative breast cancer (TNBC). To predict the biological property of TNBC, the performance using quantitative high-throughput sonographic feature analysis was compared with that using qualitative feature assessment. METHODS: We retrospectively reviewed ultrasound images, clinical, pathological, and immunohistochemical (IHC) data of 252 female TNBC patients. All patients were subgrouped according to the histological grade, Ki67 expression level, and human epidermal growth factor receptor 2 (HER2) score. Qualitative sonographic feature assessment included shape, margin, posterior acoustic pattern, and calcification referring to the Breast Imaging Reporting and Data System (BI-RADS). Quantitative sonographic features were acquired based on the computer-aided radiomics analysis. Breast cancer masses were manually segmented from the surrounding breast tissues. For each ultrasound image, 1688 radiomics features of 7 feature classes were extracted. The principal component analysis (PCA), least absolute shrinkage and selection operator (LASSO), and support vector machine (SVM) were used to determine the high-throughput radiomics features that were highly correlated to biological properties. The performance using both quantitative and qualitative sonographic features to predict biological properties of TNBC was represented by the area under the receiver operating characteristic curve (AUC). RESULTS: In the qualitative assessment, regular tumor shape, no angular or spiculated margin, posterior acoustic enhancement, and no calcification were used as the independent sonographic features for TNBC. Using the combination of these four features to predict the histological grade, Ki67, HER2, axillary lymph node metastasis (ALNM), and lymphovascular invasion (LVI), the AUC was 0.673, 0.680, 0.651, 0.587, and 0.566, respectively. The number of high-throughput features that closely correlated with biological properties was 34 for histological grade (AUC 0.942), 27 for Ki67 (AUC 0.732), 25 for HER2 (AUC 0.730), 34 for ALNM (AUC 0.804), and 34 for LVI (AUC 0.795). CONCLUSION: High-throughput quantitative sonographic features are superior to traditional qualitative ultrasound features in predicting the biological behavior of TNBC. KEY POINTS: • Sonographic appearances of TNBCs showed a great variety in accordance with its biological and clinical characteristics. • Both qualitative and quantitative sonographic features of TNBCs are associated with tumor biological characteristics. • The quantitative high-throughput feature analysis is superior to two-dimensional sonographic feature assessment in predicting tumor biological property.

ARHGAP17 enhances 5-Fluorouracil-induced apoptosis in colon cancer cells by suppressing Rac1.

Colon cancer is a common cause of death in the world, and its main cause of therapy failure is chemoresistance. Apoptosis is de-regulated in colon cancer and is one key mechanism of cancer treatment. We recently reported that reduced expression of ARHGAP17, a Rho GTPase activating protein, correlated with a poor prognosis of colon cancer patients. Here we investigated the role of ARHGAP17 in apoptosis induced by 5-fluorouracil (5-FU) in human colon cancer cells and in mouse xenograft tumor model. We observed a decreased protein level of ARHGAP17 in 5-FU resistant colon cancer cells (HCT116/5-FU and HCT8/5-FU). While ARHGAP17 knockdown attenuated apoptosis upon 5-FU treatment in HCT116 and HCT8, and ARHGAP17 overexpression in HCT116/5-FU and HCT8/5-FU cells increased apoptosis induced by 5-FU. We also found that ARHGAP17 knockdown led to a high level of active Rac1 in HCT116 and HCT8, but ARHGAP17 overexpression reduced active Rac1 in HCT116/5-FU and HCT8/5-FU cells. However, Rac1 inhibitor abolished the effect of ARHGAP17 knockdown, and Rac1 overexpression diminished the effect of ARHGAP17 overexpression on apoptosis induced by 5-FU. Apoptosis was also confirmed by cleaved Caspase-3 and cleaved PARP. Further, we observed that overexpression of ARHGAP17 promoted 5-FU-induced apoptosis and attenuated tumor growth in vivo. Collectively, our data indicate that ARHGAP17 sensitizes chemotherapy-resistant colon cancer cells to apoptosis induced by 5-FU, which is in part through suppressing Rac1.

Validating the Experiences in Close Relationships-Relationship Structures Scale among Chinese Children and Adolescents.

The Experiences in Close Relationships-Relationship Structures (ECR-RS) scale is designed to capture attachment among diverse relational contexts (e.g., parents, friends). Although the ECR-RS has begun to be applied to children and adolescents, its psychometric properties among children and adolescents are not well-known, especially concerning second-order structural validity, measurement invariance, and longitudinal predictive validity. To fill this gap, the current research examined the ECR-RS among 3,184 Chinese students (9- to 18-year old) using cross-sectional and longitudinal (6 months) data. The results demonstrated generally acceptable composite and test-retest reliabilities, and acceptable second-order structural validity. In addition, the measurement invariance of the ECR-RS held across time, relational contexts, and school levels to varying degrees. Furthermore, using a partial invariance model, we depicted the cross-sectional trajectory of attachment scores across relational contexts and school levels. Finally, attachment was associated concurrently with the Big-Five personality traits in theoretically meaningful ways and longitudinally predicted depression, anxiety, stress, and self-esteem after controlling for age, gender, and pretest scores. In conclusion, the Chinese ECR-RS has proven to be a valuable instrument for future research among children and adolescents.

[Psychological and behavioral problems in children and adolescents during the coronavirus disease 2019 epidemic: a Scoping review]. / æ–°åž‹å† çŠ¶ç— æ¯’è‚ºç‚Žæµè¡ŒæœŸé—´å„¿ç«¥å’Œé’å°‘å¹´çš„å¿ƒç†è¡Œä¸ºé—®é¢˜ï¼šScoping综述.

OBJECTIVES: To investigate the psychological and behavioral problems and related influencing factors in children and adolescents during the coronavirus disease 2019 (COVID-19) epidemic. METHODS: China National Knowledge Infrastructure, Wanfang Data, PubMed, and Web of Science were searched using the method of subject search for articles published up to March 31, 2022, and related data were extracted for Scoping review. RESULTS: A total of 3 951 articles were retrieved, and 35 articles from 12 countries were finally included. Most of the articles were from the journals related to pediatrics, psychiatry, psychology, and epidemiology, and cross-sectional survey was the most commonly used research method. Psychological and behavioral problems in children and adolescents mainly included depression/anxiety/stress, sleep disorder, internet behavior problems, traumatic stress disorder, and self-injury/suicide. Influencing factors were analyzed from the three aspects of socio-demographic characteristics, changes in living habits, and ways of coping with COVID-19. CONCLUSIONS: During the COVID-19 epidemic, the psychological and behavioral problems of children and adolescents in China and overseas are severe. In the future, further investigation and research can be carried out based on relevant influencing factors to improve the psychological and behavioral problems.

miR-338-3p inhibits autophagy in a rat model of allergic rhinitis after PM2.5 exposure through AKT/mTOR signaling by targeting UBE2Q1.

Exposure to fine particulate matter (PM2.5) increases the incidence of allergic rhinitis (AR). microRNA (miRNA) can regulate cell proliferation, invasion and apoptosis. However, the mechanism of miR-338-3p in mediating PM2.5-induced autophagy in AR animal models remains unknown. To explore the mechanism of miR-338-3p in PM2.5-induced autophagy in AR, the human nasal epithelium cells and AR model exposed to PM2.5 were deployed. The results showed that miR-338-3p was down-regulated in both nasal mucosa of PM2.5-exacerbated AR rat models and PM2.5-treated RPMI-2650 cells. Forced expression of miR-338-3p could inhibit autophagy in vitro. miR-338-3p specifically bound to UBE2Q1 3'-untranslated region (3' UTR) and negatively regulated its expression. Overexpression of UBE2Q1 attenuated the inhibitory effects of miR-338-3p on PM2.5-induced autophagy of RPMI-2650 cells through AKT/mTOR pathway. Moreover, our in vivo study found that after administration of agomiR-338-3p in AR rats model, the expression of autophagy-related proteins decreased and nasal symptoms alleviated. In conclusion, this study revealed that miR-338-3p acts as an autophagy suppressor in PM2.5-exacerbated AR by directly targeting UBE2Q1 and affecting AKT/mTOR pathway.

Characterization of Patients With Refractory or Unexplained Chronic Cough Participating in a Phase 2 Clinical Trial of the P2X3-Receptor Antagonist Gefapixant.

PURPOSE: This analysis assesses clinical characteristics of patients with refractory chronic cough (RCC) or unexplained chronic cough (UCC) enrolled in a phase 2 study to better understand this patient population. METHODS: Patients with RCC/UCC lasting for ≥ 1 year and cough severity visual analog scale (VAS) score of > 40 mm at screening were eligible. Demographics, clinical characteristics, and medical history were collected at baseline. Cough-related measures included cough severity VAS, Cough Severity Diary (CSD), Leicester Cough Questionnaire (LCQ), and a structured cough-trigger questionnaire. Medication history included all medications 30 days before screening and chronic cough treatments within 1 year before screening. Data were summarized using descriptive statistics. RESULTS: Patients (N = 253; female, 76%; mean age, 60 years) had severe (mean cough severity VAS, 57.5 mm) and long-lasting (median duration, 11 years) cough. The most burdensome self-reported aspects included psychological and social factors (LCQ) and cough frequency and intensity (CSD). Patient-reported triggers were consistent with cough hypersensitivity (e.g., 95% to 96% reported irritation or tickle in throat). Common reported comorbidities included gastroesophageal reflux disease (GERD; 56%), allergic rhinitis (47%), and asthma (30%); 12% of patients had been diagnosed with all 3 conditions. The most common prior medications included inhaled or oral steroids (21%), antihistamines (15%), and antacids (15%). CONCLUSION: Patients with RCC/UCC had severe, long-lasting, and burdensome cough with clinical features of cough hypersensitivity. Many patients had been diagnosed with GERD, allergic rhinitis, and asthma but had a persistent cough despite treatment of these conditions. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02612610; registered November 20, 2015.

A method identifying key optimisation points for aircraft seat comfort.

Seating is the overriding factor influencing aircraft cabin comfort. To efficiently enhance seat comfort, this paper proposes a method to identify key optimisation points for seat comfort. Seat discomfort indicators are recognised based on a comparison of perceived performance with expectation. Confirmatory factor analysis is used to explore the latent variables of discomfort indicators, and a structural model was used to analyse correlations between latent variables. Finally, the most important latent variable influencing seat comfort was clarified. Analysis results of survey data from narrow-body aircraft show that seat discomfort indicators centre on the physical performance of the seat and include four latent variables: support performance, personal space, contact surface features, and safety and stability. Support performance determines body posture while travelling and is the overriding latent variable influencing seat comfort. This research establishes aircraft seat discomfort indicators, latent variables formed through the mutual linkage of discomfort indicators, and the structural relations between latent variables. The results can assist in the formulation of comfort optimisation procedures for aircraft seats. Practitioner summary: A method identifying the key points of aircraft seat comfort optimisation was proposed, which includes three steps: recognising discomfort indicators, exploring the relationship between discomfort indicators, and confirming the most important variable influencing seat comfort. Results provide guidance for aircraft seat optimisation. Abbreviations: SEM: structural equation modelling; EFA: exploratory factor analysis; CFA: confirmatory factor analysis; PA-OV: path analysis with observed variables; CR: construct reliability; AVE: average variance extracted; CMIN: likelihood-ratio chi-square; DF: degrees of freedom; GFI: goodness-of -fit index; AGFI: adjusted goodness-of -fit index; RMSEA: root mean square error of approximation; NNFI: non-normed fit index; RFI: relative fit index; CFI: comparative fit index; CN: critical N.

Gefapixant in two randomised dose-escalation studies in chronic cough.

BACKGROUND AND OBJECTIVES: Gefapixant has previously demonstrated efficacy in the treatment of refractory chronic cough at a high daily dose. The current investigations explore efficacy and tolerability of gefapixant, a P2X3 receptor antagonist, for the treatment of chronic cough using a dose-escalation approach. MATERIALS AND METHODS: Two randomised, double-blind, placebo-controlled, crossover, dose-escalation studies recruited participants with refractory chronic cough. Patients were assigned to receive ascending doses of gefapixant (study 1: 50-200 mg, study 2: 7.5-50 mg) or placebo for 16 days, then crossed-over after washout. The primary end-point was awake cough frequency assessed using a 24-h ambulatory cough monitor at baseline and on day 4 of each dose. Patient-reported outcomes included a cough severity visual analogue scale and the cough severity diary. RESULTS: In clinical studies, gefapixant doses ≥30 mg produced maximal improvements in cough frequency compared with placebo (p<0.05); reported cough severity measures improved at similar doses. Taste disturbance exhibited a different relationship with dose, apparently maximal at doses ≥150 mg. CONCLUSIONS: P2X3 antagonism with gefapixant demonstrates anti-tussive efficacy and improved tolerability at lower doses than previously investigated. Studies of longer duration are warranted.

Experimental Investigation of State Distinguishability in Parity-Time Symmetric Quantum Dynamics.

Comprehensive study on parity-time (PT) symmetric systems demonstrates the novel properties and innovative application of non-Hermitian physics in recent years. In the quantum regime, PT symmetric physics exhibits unique quantum dynamical behaviors such as spontaneous state-distinguishability oscillation. However, the construction and control of a PT symmetric quantum system are still challenging, that and restrict the experimental investigation of PT symmetric quantum nature and application. In this Letter, we propose and construct a recycling-structure PT symmetric quantum simulator for the first time, which can effectively simulate the discrete-time dynamical process of a PT symmetric quantum system in both unbroken and broken phases, to be different from our previous work [J.-S. Tang, et al., Nat. Photonics 10, 642 (2016)]. We investigate the dynamical features of quantum state distinguishability based on the PT symmetric simulator. Our results demonstrate the novel PT symmetric quantum dynamics characterized by the periodical oscillation of state distinguishability in the unbroken phase, and the monotonic decay of that in the broken phase. This work also provides a practical experimental platform for the future intensive study of PT symmetric quantum dynamics.

Experimental Investigation of Quantum PT-Enhanced Sensor.

PT-symmetric theory is developed to extend quantum mechanics to a complex region, but it wins its great success first in classical systems, for example, optical waveguides and electric circuits, etc., because there are so many counterintuitive phenomena and striking applications, including unidirectional light transport, PT-enhanced sensors (one kind of exceptional-point-based sensor), and wireless power transfer. However, these phenomena and applications are mostly based on the ability to approach a PT-symmetric broken region, which makes it difficult to transfer them to the quantum regime, since the broken quantum PT-symmetric system has not been constructed effectively, until recently several methods have been raised. Here, we construct a quantum PT-symmetric system assisted by weak measurement, which can effectively transit from the unbroken region to the broken region. The full energy spectrum including the real and imaginary parts is directly measured using weak values. Furthermore, based on the ability of approaching a broken region, we for the first time translate the previously mentioned PT-enhanced sensor into the quantum version, and investigate its various features that are associated to the optimal conditions for sensitivity enhancement. In this experiment, we obtain an enhancement of 8.856 times over the conventional Hermitian sensor. Moreover, by separately detecting the real and imaginary parts of energy splitting, we can derive the additional information of the direction of perturbations. Our work paves the way of leading classical interesting PT phenomena and applications to their quantum counterparts. More generally, since the PT system is a subset of non-Hermitian systems, our work will be also helpful in the studies of general exception point in the quantum regime.

Experimental Observation of Coherent-Information Superadditivity in a Dephrasure Channel.

We present an experimental approach to construct a dephrasure channel that contains both dephasing and erasure noises and can be used as an efficient tool to study the superadditivity of coherent information. Using a three-fold dephrasure channel, the superadditivity of coherent information is observed, and a substantial gap is found between the zero single-letter coherent information and zero quantum capacity. Particularly, we find that, when the coherent information of n channel uses is zero, with a larger number of channel uses the quantum capacity becomes positive. These phenomena exhibit a more obvious superadditivity of coherent information than previous works and demonstrate a higher threshold for nonzero quantum capacity. Such novel channels built in our experiment also can provide a useful platform to study the nonadditive properties of coherent information and quantum channel capacity.

Daphnetin protects hippocampal neurons from oxygen-glucose deprivation-induced injury.

Daphnetin, a coumarin derivative extracted from Daphne odora var., was reported to possess a neuroprotective effect. Recently, it has been demonstrated that daphnetin attenuates ischemia/reperfusion (I/R) injury. However, the role of daphnetin in cerebral I/R injury and the potential mechanism have not been fully understood. The present study aimed to explore the regulatory roles of daphnetin on oxygen-glucose deprivation/reoxygenation (OGD/R)-induced cell injury in a model of hippocampal neurons. Our results demonstrated that daphnetin improved cell viability and reduced the lactate dehydrogenase leakage in OGD/R-stimulated hippocampal neurons. In addition, daphnetin inhibited oxidative stress and cell apoptosis in hippocampal neurons after OGD/R stimulation. Furthermore, daphnetin significantly enhanced the nuclear translocation of the nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) expression in hippocampal neurons exposed to OGD/R. Knockdown of Nrf2 blocked the protective effect of daphnetin on OGD/R-induced hippocampal neurons. In conclusion, these findings demonstrated that daphnetin attenuated oxidative stress and neuronal apoptosis after OGD/R injury through the activation of the Nrf2/HO-1 signaling pathway in hippocampal neurons. Thus, daphnetin may be a novel therapeutic agent for cerebral I/R injury.

Construction of Bispirooxindole Heterocycles via Palladium-Catalyzed Ring-Opening Formal [3 + 2]-Cycloaddition of Spirovinylcyclopropyl Oxindole and 3-Oxindole Derivatives.

A palladium-catalyzed ring-opening oxo-formal [3 + 2]-cycloaddition reaction of novel donor-acceptor spirovinylcyclopropyl oxindole with 3-oxindole is described. The developed protocol provides facile access to oxo-bispirooxindole derivatives in good yields (up to 82% yield) with excellent diastereoselectivities (up to 20:1 dr).

Analysis of Passivation Techniques in InP HEMTs and Implementation of an Analytical Model of fT Based on the Small Signal Equivalent Circuit.

This paper analyses, the influence of Si3N4-PECVD and Al2O3-ALD surface passivation on the DC and RF characteristics of InP HEMTs with different gate lengths 0.08 µm, 0.1 µm, 0.12 µm, and 0.15 µm. A significant improvement in maximum drain current IDS, MAX, transconductance gm, MAX and oscillation frequency fmax, MAX is obtained by scaling the thickness of the passivation layers An increase in gm, MAX and fmax, MAX, fT, MAX is observed by reducing parasitic capacitance w.r.t. the decrease in gate length. In addition, an analytical model of fT based on a small-signal equivalent circuit is developed, which consist of extrinsic parameters Rs, Rd, Cgs_ext and Cgd_ext and intrinsic parameters Cgsi, Cgdi, gmi and goi. The carrier transport is improved by increasing gmi, thus the transit time τt , the parasitic charging delay τext and the τpar are reduced by lowering the extrinsic capacitances. An excellent fitting between measured and simulated fT is achieved, which inturn leads a realistic way for further improvement in fT.

Improved Characterization and Accurate Modelling of Drain Current Derivatives of InP Based High Electron Mobility Transistors Devices.

InP based HEMTs are of great importance, due to their enormous potential in a high-speed modern microwave circuit, power amplifier, and low noise amplifier applications. Therefore, an accurate non-linear equivalent circuit model of HEMTs is very important for an accurate circuit design. This paper presents improved characterization and accurate modelling of drain current derivatives of InP based HEMTs devices. The proposed model is simple, easy to extract, and suitable for implementation in simulation tools. The Ψ function is extended to increase the flexibility of the proposed model. A gate-drain dependent current source is added to increase the S-parameter fitting. A one-dimensional intrinsic multi-bias capacitances model is introduced to avoid convergence failure. The fitting results of the I-V characteristics and its high order derivatives show high accuracy. In addition, S-parameters and Pout for the proposed model are compared with the original Angelov model. The proposed model shows better accuracy.

How Medic-Patient Communication and Relationship Influence Chinese Patients' Treatment Adherence.

The deterioration of medic-patient relation in China raises the question about its impact on patients' adherence to medical instructions. This study focuses on how the quantity and quality of medic-patient communication influences their relationship, and how the perceived relationship at individual level, institution level, and society level influences patients' treatment adherence, through a survey conducted in a city of Southern China (N = 597, Response rate = 66%). The results of path analysis show that consulting time is positively associated with patients' relationship with individual doctors and the whole medical system, as well as their satisfaction with hospital. Unpleasant experience of having disputes with medical workers is negatively associated with the medic-patient relationship at all of the three levels and causes conditional nonadherence. The more positive medic-patient relationship perceived by the patients, the more likely they will display unconditional adherence.

Experimental Investigation of Spectra of Dynamical Maps and their Relation to non-Markovianity.

The spectral theorem of von Neumann has been widely applied in various areas, such as the characteristic spectral lines of atoms. It has been recently proposed that dynamical evolution also possesses spectral lines. As the most intrinsic property of evolution, the behavior of these spectra can, in principle, exhibit almost every feature of this evolution, among which the most attractive topic is non-Markovianity, i.e., the memory effects during evolution. Here, we develop a method to detect these spectra, and moreover, we experimentally examine the relation between the spectral behavior and non-Markovianity by engineering the environment to prepare dynamical maps with different non-Markovian properties and then detecting the dynamical behavior of the spectral values. These spectra will lead to a witness for essential non-Markovianity. We also experimentally verify another simplified witness method for essential non-Markovianity. Interestingly, in both cases, we observe the sudden transition from essential non-Markovianity to something else. Our work shows the role of the spectra of evolution in the studies of non-Makovianity and provides the alternative methods to characterize non-Markovian behavior.

Efficient resolution of venlafaxine and mechanism study via X-ray crystallography.

Numbers of resolving factors were investigated to improve resolution of venlafaxine 1. An effective resolving agent, O,O'-di-p-toluoyl-(R, R)-tartaric acid 2, was screened using similar method of 'Dutch resolution' from tartaric acid derivatives. The resolution efficiency was up to 88.4%, when the ratio of rac-1 and 2 was 1:0.8 in THF with little water (10:1 v/v). Enantiomerically pure venlafaxine was prepared with 99.1% ee in 82.2% yield. The chiral resolution mechanism was first explained through X-ray crystallographic study. One diastereomeric salt with well solubility forms a columnar supramolecular structure as the acidic salt (R)-1·2, while the other diastereomeric salt with less solubility forms a multilayered sandwich supramolecular structure by enantio-differentiation self-assembly as the neutral salt 2(S)-1·2. The water molecules play a key role in the optical resolution, as indicated by the special structures of the diastereomeric salts.

Expression profiles of circular RNAs in sheep skeletal muscle.

OBJECTIVE: Circular RNAs (circRNAs) are a newfound class of non-coding RNA in animals and plants. Recent studies have revealed that circRNAs play important roles in cell proliferation, differentiation, autophagy and apoptosis during development. However, there are few reports about muscle development-related circRNAs in livestock. METHODS: RNA sequencing analysis was employed to identify and annotate circRNAs from longissimus dorsi of sheep. Reverse transcription followed by real-time quantitative (q) polymerase chain reaction (PCR) analysis verified the presence of these circRNAs. Targetscan7.0 and miRanda were used to analyse the interaction of circRNA-microRNA (miRNA). To investigate the function of circRNAs, an experiment was conducted to perform enrichment analysis hosting genes of circRNAs using gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) pathways. RESULTS: About 75.5 million sequences were obtained from RNA libraries of sheep skeletal muscle. These sequences were mapped to 729 genes in the sheep reference genome. We identified 886 circRNAs, including numerous circular intronic RNAs and exonic circRNAs. Reverse transcription PCR (RT-PCR) and DNA sequencing analysis confirmed the presence of several circRNAs. Real-Time RT-PCR analysis exhibited resistance of sheep circRNAs to RNase R digestion. We found that many circRNAs interacted with muscle-specific miRNAs involved in growth and development of muscle, especially circ776. The GO and KEGG enrichment analysis showed that hosting genes of circRNAs was involved in muscle cell development and signaling pathway. CONCLUSION: The study provides comprehensive expression profiles of circRNAs in sheep skeletal muscle. Our study offers a large number of circRNAs to facilitate a better understanding of their roles in muscle growth. Meanwhile, we suggested that circ776 could be analyzed in future study.