Measurements of All-Particle Energy Spectrum and Mean Logarithmic Mass of Cosmic Rays from 0.3 to 30 PeV with LHAASO-KM2A

We present the measurements of all-particle energy spectrum and mean logarithmic mass of cosmic rays in the energy range of 0.3-30 PeV using data collected from LHAASO-KM2A between September 2021 and December 2022, which is based on a nearly composition-independent energy reconstruction method, achieving unprecedented accuracy. Our analysis reveals the position of the knee at 3.67±0.05±0.15  PeV. Below the knee, the spectral index is found to be -2.7413±0.0004±0.0050, while above the knee, it is -3.128±0.005±0.027, with the sharpness of the transition measured with a statistical error of 2%. The mean logarithmic mass of cosmic rays is almost heavier than helium in the whole measured energy range. It decreases from 1.7 at 0.3 PeV to 1.3 at 3 PeV, representing a 24% decline following a power law with an index of -0.1200±0.0003±0.0341. This is equivalent to an increase in abundance of light components. Above the knee, the mean logarithmic mass exhibits a power law trend towards heavier components, which is reversal to the behavior observed in the all-particle energy spectrum. Additionally, the knee position and the change in power-law index are approximately the same. These findings suggest that the knee observed in the all-particle spectrum corresponds to the knee of the light component, rather than the medium-heavy components.

[Effects of nasal valve on subjective nasal patency and nasal resistance: a correlation study on numerical simulation of nasal airflow]

Objective: To investigate the correlations between subjective nasal patency, nasal valve area size and aerodynamic parameters in normal nasal cavity by means of numerical simulation, and to explore the effect of nasal valve on nasal subjective sensation and nasal airflow regulation. Methods: A total of 52 healthy participants (31 males and 21 females) with the average age of 37.8 years, were recruited from the outpatient Department of Otorhinolaryngology Head and Neck Surgery, the Ninth People's Hospital Affiliated to the Medical College of Shanghai Jiao Tong University between January and August 2023. Visual Analog Scale (VAS) scores for unilateral nasal subjective sensation were obtained from all participants. Additionally, the aerodynamic characteristics of inspiratory airflow were simulated. A correlation matrix analysis was conducted to identify the correlation strength between these subjective and objective parameters. Results: VAS scores showed negative correlations with unilateral nasal valve cross-sectional area (r=-0.85, P<0.01) and unilateral intranasal airflow (r=-0.57, P<0.01), and was a positive correlation with unilateral nasal resistance (NR) at the front-end of inferior turbinate (r=0.61, P<0.01). The average cross-sectional area of unilateral nasal valve was (0.85±0.35) cm2. The cross-sectional area of unilateral nasal valve was negatively correlated with unilateral NR (r=-0.50, P<0.01), and positively correlated with unilateral nasal airflow (r=0.61, P<0.01). The NR at the nasal valve area accounted for (40.41±23.54)% of the total unilateral NR. Nearly half of the unilateral NR [(46.74±21.38)%] and air warming [(49.96±10.02)%] occurring before the front end of inferior turbinate were achieved. Conclusions: The nasal valve area plays a crucial role in influencing nasal NR, unilateral nasal airflow, and changes in nasal airflow temperature. Moreover, it is associated with subjective perception of nasal patency.

SARS-CoV-2 and oncolytic EV-D68-encoded proteases differentially regulate pyroptosis

Pyroptosis, a pro-inflammatory programmed cell death, has been implicated in the pathogenesis of coronavirus disease 2019 and other viral diseases. Gasdermin family proteins (GSDMs), including GSDMD and GSDME, are key regulators of pyroptotic cell death. However, the mechanisms by which virus infection modulates pyroptosis remain unclear. Here, we employed a mCherry-GSDMD fluorescent reporter assay to screen for viral proteins that impede the localization and function of GSDMD in living cells. Our data indicated that the main protease NSP5 of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) blocked GSDMD-mediated pyroptosis via cleaving residues Q29 and Q193 of GSDMD. While another SARS-CoV-2 protease, NSP3, cleaved GSDME at residue G370 but activated GSDME-mediated pyroptosis. Interestingly, respiratory enterovirus EV-D68-encoded proteases 3C and 2A also exhibit similar differential regulation on the functions of GSDMs by inactivating GSDMD but initiating GSDME-mediated pyroptosis. EV-D68 infection exerted oncolytic effects on human cancer cells by inducing pyroptotic cell death. Our findings provide insights into how respiratory viruses manipulate host cell pyroptosis and suggest potential targets for antiviral therapy as well as cancer treatment.IMPORTANCEPyroptosis plays a crucial role in the pathogenesis of coronavirus disease 2019, and comprehending its function may facilitate the development of novel therapeutic strategies. This study aims to explore how viral-encoded proteases modulate pyroptosis. We investigated the impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and respiratory enterovirus D68 (EV-D68) proteases on host cell pyroptosis. We found that SARS-CoV-2-encoded proteases NSP5 and NSP3 inactivate gasdermin D (GSDMD) but initiate gasdermin E (GSDME)-mediated pyroptosis, respectively. We also discovered that another respiratory virus EV-D68 encodes two distinct proteases 2A and 3C that selectively trigger GSDME-mediated pyroptosis while suppressing the function of GSDMD. Based on these findings, we further noted that EV-D68 infection triggers pyroptosis and produces oncolytic effects in human carcinoma cells. Our study provides new insights into the molecular mechanisms underlying virus-modulated pyroptosis and identifies potential targets for the development of antiviral and cancer therapeutics.

SARS-CoV-2 Nsp8 suppresses MDA5 antiviral immune responses by impairing TRIM4-mediated K63-linked polyubiquitination

Melanoma differentiation-associated gene-5 (MDA5) acts as a cytoplasmic RNA sensor to detect viral dsRNA and mediates antiviral innate immune responses to infection by RNA viruses. Upon recognition of viral dsRNA, MDA5 is activated with K63-linked polyubiquitination and then triggers the recruitment of MAVS and activation of TBK1 and IKKα/β, subsequently leading to IRF3 and NF-κB phosphorylation. However, the specific E3 ubiquitin ligase for MDA5 K63-polyubiquitination has not been well characterized. Great numbers of symptomatic and severe infections of SARS-CoV-2 are spreading worldwide, and the poor efficacy of treatment with type I interferon and antiviral immune agents indicates that SARS-CoV-2 escapes from antiviral immune responses via several unknown mechanisms. Here, we report that SARS-CoV-2 nonstructural protein 8 (nsp8) acts as a suppressor of antiviral innate immune and inflammatory responses to promote infection of SARS-CoV-2. It downregulates the expression of type I interferon, IFN-stimulated genes and proinflammatory cytokines by binding to MDA5 and TRIM4 and impairing TRIM4-mediated MDA5 K63-linked polyubiquitination. Our findings reveal that nsp8 mediates innate immune evasion during SARS-CoV-2 infection and may serve as a potential target for future therapeutics for SARS-CoV-2 infectious diseases.

Measurement of Ultra-High-Energy Diffuse Gamma-Ray Emission of the Galactic Plane from 10 TeV to 1 PeV with LHAASO-KM2A

The diffuse Galactic γ-ray emission, mainly produced via interactions between cosmic rays and the interstellar medium and/or radiation field, is a very important probe of the distribution, propagation, and interaction of cosmic rays in the Milky Way. In this Letter, we report the measurements of diffuse γ rays from the Galactic plane between 10 TeV and 1 PeV energies, with the square kilometer array of the Large High Altitude Air Shower Observatory (LHAASO). Diffuse emissions from the inner (15°10  TeV). The energy spectrum in the inner Galaxy regions can be described by a power-law function with an index of -2.99±0.04, which is different from the curved spectrum as expected from hadronic interactions between locally measured cosmic rays and the line-of-sight integrated gas content. Furthermore, the measured flux is higher by a factor of ∼3 than the prediction. A similar spectrum with an index of -2.99±0.07 is found in the outer Galaxy region, and the absolute flux for 10≲E≲60  TeV is again higher than the prediction for hadronic cosmic ray interactions. The latitude distributions of the diffuse emission are consistent with the gas distribution, while the longitude distributions show clear deviation from the gas distribution. The LHAASO measurements imply that either additional emission sources exist or cosmic ray intensities have spatial variations.

A tera-electron volt afterglow from a narrow jet in an extremely bright gamma-ray burst

Some gamma-ray bursts (GRBs) have a tera-electron volt (TeV) afterglow, but the early onset of this has not been observed. We report observations with the Large High Altitude Air Shower Observatory of the bright GRB 221009A, which serendipitously occurred within the instrument field of view. More than 64,000 photons >0.2 TeV were detected within the first 3000 seconds. The TeV flux began several minutes after the GRB trigger, then rose to a peak about 10 seconds later. This was followed by a decay phase, which became more rapid ~650 seconds after the peak. We interpret the emission using a model of a relativistic jet with half-opening angle ~0.8°. This is consistent with the core of a structured jet and could explain the high isotropic energy of this GRB.

SARS-CoV-2 NSP8 suppresses type I and III IFN responses by modulating the RIG-I/MDA5, TRIF, and STING signaling pathways

SARS-CoV-2 has developed a variety of approaches to counteract host innate antiviral immunity to facilitate its infection, replication and pathogenesis, but the molecular mechanisms that it employs are still not been fully understood. Here, we found that SARS-CoV-2 NSP8 inhibited the production of type I and III IFNs by acting on RIG-I/MDA5 and the signaling molecules TRIF and STING. Overexpression of NSP8 downregulated the expression of type I and III IFNs stimulated by poly (I:C) transfection and infection with SeV and SARS-CoV-2. In addition, NSP8 impaired IFN expression triggered by overexpression of the signaling molecules RIG-I, MDA5, and MAVS, instead of TBK1 and IRF3-5D, an active form of IRF3. From a mechanistic view, NSP8 interacts with RIG-I and MDA5, and thereby prevents the assembly of the RIG-I/MDA5-MAVS signalosome, resulting in the impaired phosphorylation and nuclear translocation of IRF3. NSP8 also suppressed the TRIF- and STING- induced IFN expression by directly interacting with them. Moreover, ectopic expression of NSP8 promoted virus replications. Taken together, SARS-CoV-2 NSP8 suppresses type I and III IFN responses by disturbing the RIG-I/MDA5-MAVS complex formation and targeting TRIF and STING signaling transduction. These results provide new insights into the pathogenesis of COVID-19. This article is protected by copyright. All rights reserved.

[Study on static parameters of internal nasal valve in 3-dimensional model of nasal cavity space]

Objective: To identify the internal nasal valve (INV) and to evaluate its key parameters in the established 3D models of nasal cavity space via Mimics from CT images, in order to provide evidence for quantitative diagnosis of nasal valve compromise. Methods: A total of 32 Han adults without nasal diseases who underwent maxillofacial CT test in Shanghai Ninth People's Hospital from January 2015 to December 2018 were retrospectively recruited, including 16 males and 16 females, with the age ranged from 20 to 80 years (50% age<50 years old). Maxillofacial CT images were used to create 3D model of nasal cavity space. The INV was identified and the following parameters were measured: the angle between the INV and the nasal bone (θ_INV-B), unilateral cross-sectional area of the INV (A_INV-R, A_INV-L), total cross-sectional area of the INV (A_INV), unilateral height of the INV (H_INV-R, H_INV-L), unilateral nasal valve angle (α_INV-R, α_INV-L), and the sum of nasal valve angle (α_INV). The A_INV in our study was compared with the results of the previously adopted planes (Plane_C, perpendicular to the hard palate and Plane_B, plane perpendicular to the nasal bone). The parameters above were compared among genders, age and race groups. SPSS 26 and GraphPad Prism 9 software were used for statistical analysis and mapping of data. Results: The A_INV in our study was (214.87±52.94) mm², which was significantly less than that of Plane_C (254.97±47.80) mm² and Plane_B (226.07±57.36) mm². The measured parameters were as follows: θ_INV-B was (82.07±7.06)°; A_INV-R was (112.66±31.39) mm²; A_INV-L was (102.21±27.14) mm²; A_INV was (214.87±52.94) mm²; H_INV-R was (24.87±4.62) mm; H_INV-L was (24.35±4.86) mm; α_INV-R was (20.48±2.99)°; α_INV-L was (19.65±3.82)°; α_INV was (40.13±6.24)°. The A_INV-R was larger than A_INV-L (t=2.33, P<0.05); The H_INV, A_INV-R, A_INV-L and A_INV of males were more than those of females (t value was 5.77, 3.21, 2.91 and 3.52, respectively, all P<0.01). The A_INV of the young group (<50 years) was larger than that of the old group (t=2.83, P<0.01); The θ_INV-B was different between the Han people and the Caucasian (t=2.92,P<0.01). The α_INV of the Han people was larger than that of Caucasians (Z=-6.92, P<0.01), but the H_INV was smaller (Z=-3.89, P<0.01). Conclusion: The A_INV carried out in 3D models of nasal cavity space is significantly smaller than that obtained by the previous methods of CT evaluation. INV static parameters differ among genders, age and race groups.

Ectopic expression of SARS-CoV-2 S and ORF-9B proteins alters metabolic profiles and impairs contractile function in cardiomyocytes

Coronavirus disease 2019 (COVID-19) is associated with adverse impacts in the cardiovascular system, but the mechanisms driving this response remain unclear. In this study, we conducted "pseudoviral infection" of SARS-CoV-2 subunits to evaluate their toxic effects in cardiomyocytes (CMs), that were derived from human induced pluripotent stem cells (hiPSCs). We found that the ectopic expression of S and ORF-9B subunits significantly impaired the contractile function and altered the metabolic profiles in human cardiomyocytes. Further mechanistic study has shown that the mitochondrial oxidative phosphorylation (OXPHOS), membrane potential, and ATP production were significantly decreased two days after the overexpression of S and ORF-9B subunits, while S subunits induced higher level of reactive oxygen species (ROS). Two weeks after overexpression, glycolysis was elevated in the ORF-9B group. Based on the transcriptomic analysis, both S and ORF-9B subunits dysregulated signaling pathways associated with metabolism and cardiomyopathy, including upregulated genes involved in HIF-signaling and downregulated genes involved in cholesterol biosynthetic processes. The ORF-9B subunit also enhanced glycolysis in the CMs. Our results collectively provide an insight into the molecular mechanisms underlying SARS-CoV-2 subunits-induced metabolic alterations and cardiac dysfunctions in the hearts of COVID-19 patients.

SARS-CoV-2 NSP7 inhibits type I and III IFN production by targeting the RIG-I/MDA5, TRIF, and STING signaling pathways

SARS-CoV-2 is a poor inducer of innate antiviral immunity, and the underlying mechanism still needs further investigation. Here, we reported that SARS-CoV-2 NSP7 inhibited the production of type I and III IFNs by targeting the RIG-I/MDA5, TLR3-TRIF, and cGAS-STING signaling pathways. SARS-CoV-2 NSP7 suppressed the expression of IFNs and IFN-stimulated genes induced by poly (I:C) transfection and infection with Sendai virus or SARS-CoV-2 virus-like particles. NSP7 impaired type I and III IFN production activated by components of the cytosolic dsRNA-sensing pathway, including RIG-I, MDA5, and MAVS, but not TBK1, IKKε, and IRF3-5D, an active form of IRF3. In addition, NSP7 also suppressed TRIF- and STING-induced IFN responses. Mechanistically, NSP7 associated with RIG-I and MDA5 prevented the formation of the RIG-I/MDA5-MAVS signalosome and interacted with TRIF and STING to inhibit TRIF-TBK1 and STING-TBK1 complex formation, thus reducing the subsequent IRF3 phosphorylation and nuclear translocation that are essential for IFN induction. In addition, ectopic expression of NSP7 impeded innate immune activation and facilitated virus replication. Taken together, SARS-CoV-2 NSP7 dampens type I and III IFN responses via disruption of the signal transduction of the RIG-I/MDA5-MAVS, TLR3-TRIF, and cGAS-STING signaling pathways, thus providing novel insights into the interactions between SARS-CoV-2 and innate antiviral immunity. This article is protected by copyright. All rights reserved.

Manipulation of innate immune signaling pathways by SARS-CoV-2 non-structural proteins

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of the current coronavirus disease 2019 (COVID-19) pandemic, induces an unbalanced immune response in the host. For instance, the production of type I interferon (IFN) and the response to it, which act as a front-line defense against virus invasion, are inhibited during SARS-CoV-2 infection. In addition, tumor necrosis factor alpha (TNF-α), a proinflammatory cytokine, is upregulated in COVID-19 patients with severe symptoms. Studies on the closely related betacoronavirus, SARS-CoV, showed that viral proteins such as Nsp1, Orf6 and nucleocapsid protein inhibit IFN-β production and responses at multiple steps. Given the conservation of these proteins between SARS-CoV and SARS-CoV-2, it is not surprising that SARS-CoV-2 deploys similar immune evasion strategies. Here, we carried out a screen to examine the role of individual SARS-CoV-2 proteins in regulating innate immune signaling, such as the activation of transcription factors IRF3 and NF-κB and the response to type I and type II IFN. In addition to established roles of SARS-CoV-2 proteins, we report that SARS-CoV-2 proteins Nsp6 and Orf8 inhibit the type I IFN response but at different stages. Orf6 blocks the translocation of STAT1 and STAT2 into the nucleus, whereas ORF8 inhibits the pathway in the nucleus after STAT1/2 translocation. SARS-CoV-2 Orf6 also suppresses IRF3 activation and TNF-α-induced NF-κB activation.

SARS-CoV-2 ORF3a induces RETREG1/FAM134B-dependent reticulophagy and triggers sequential ER stress and inflammatory responses during SARS-CoV-2 infection

SARS-CoV-2 infections have resulted in a very large number of severe cases of COVID-19 and deaths worldwide. However, knowledge of SARS-CoV-2 infection, pathogenesis and therapy remains limited, emphasizing the urgent need for fundamental studies and drug development. Studies have shown that induction of macroautophagy/autophagy and hijacking of the autophagic machinery are essential for the infection and replication of SARS-CoV-2; however, the mechanism of this manipulation and the function of autophagy during SARS-CoV-2 infection remain unclear. In the present study, we identified ORF3a as an inducer of autophagy (in particular reticulophagy) and revealed that ORF3a localizes to the ER and induces RETREG1/FAM134B-related reticulophagy through the HMGB1-BECN1 (beclin 1) pathway. As a consequence, ORF3a induces ER stress and inflammatory responses through reticulophagy and then sensitizes cells to the acquisition of an ER stress-related early apoptotic phenotype and facilitates SARS-CoV-2 infection, suggesting that SARS-CoV-2 ORF3a hijacks reticulophagy and then disrupts ER homeostasis to induce ER stress and inflammatory responses during SARS-CoV-2 infection. These findings reveal the sequential induction of reticulophagy, ER stress and acute inflammatory responses during SARS-CoV-2 infection and imply the therapeutic potential of reticulophagy and ER stress-related drugs for COVID-19.Abbreviations: CQ: chloroquine; DEGs: differentially expressed genes; ER: endoplasmic reticulum; GSEA: gene set enrichment analysis; HMGB1: high mobility group box 1; HMOX1: heme oxygenase 1; MERS-CoV: Middle East respiratory syndrome coronavirus; RETREG1/FAM134B: reticulophagy regulator 1; RTN4: reticulon 4; SARS-CoV-2: severe acute respiratory syndrome coronavirus 2; TN: tunicamycin.

An antibody-based proximity labeling protocol to identify biotinylated interactors of SARS-CoV-2

Elucidating the molecular interactions between virus and host is fundamental to understanding the mechanism of viral pathogenesis. Here, we present a protocol to screen SARS-CoV-2 protein interactors using an antibody-based TurboID proximity labeling approach. This technique directly identifies biotinylated peptides labeled by the TurboID-tagged viral proteins. We describe the steps to prepare biotinylated peptide samples for mass spectrometry analysis and a stringent workflow to identify biotinylated high-confidence interactors of the virus by filtering out non-specific co-purified proteins.

For complete details on the use and execution of this protocol, please refer to Zhang et al. (2022).

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Proximity labeling to identify high-confidence SARS-CoV-2 interactors

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Enrichment of biotinylated proteins by TurboID using anti-biotin antibody

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A stringent proteomics workflow to filter non-specific co-purified proteins

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Protocol can be applied to other viral-host protein interaction studies

Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics.

SARS-CoV-2 NSP5 and N protein counteract the RIG-I signaling pathway by suppressing the formation of stress granules

As a highly pathogenic human coronavirus, SARS-CoV-2 has to counteract an intricate network of antiviral host responses to establish infection and spread. The nucleic acid-induced stress response is an essential component of antiviral defense and is closely related to antiviral innate immunity. However, whether SARS-CoV-2 regulates the stress response pathway to achieve immune evasion remains elusive. In this study, SARS-CoV-2 NSP5 and N protein were found to attenuate antiviral stress granule (avSG) formation. Moreover, NSP5 and N suppressed IFN expression induced by infection of Sendai virus or transfection of a synthetic mimic of dsRNA, poly (I:C), inhibiting TBK1 and IRF3 phosphorylation, and restraining the nuclear translocalization of IRF3. Furthermore, HEK293T cells with ectopic expression of NSP5 or N protein were less resistant to vesicular stomatitis virus infection. Mechanistically, NSP5 suppressed avSG formation and disrupted RIG-I-MAVS complex to attenuate the RIG-I-mediated antiviral immunity. In contrast to the multiple targets of NSP5, the N protein specifically targeted cofactors upstream of RIG-I. The N protein interacted with G3BP1 to prevent avSG formation and to keep the cofactors G3BP1 and PACT from activating RIG-I. Additionally, the N protein also affected the recognition of dsRNA by RIG-I. This study revealed the intimate correlation between SARS-CoV-2, the stress response, and innate antiviral immunity, shedding light on the pathogenic mechanism of COVID-19.

An antibody-based proximity labeling map reveals mechanisms of SARS-CoV-2 inhibition of antiviral immunity

The global epidemic caused by the coronavirus severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has resulted in the infection of over 200 million people. To extend the knowledge of interactions between SARS-CoV-2 and humans, we systematically investigate the interactome of 29 viral proteins in human cells by using an antibody-based TurboID assay. In total, 1,388 high-confidence human proximal proteins with biotinylated sites are identified. Notably, we find that SARS-CoV-2 manipulates the antiviral and immune responses. We validate that the membrane protein ITGB1 associates angiotensin-converting enzyme 2 (ACE2) to mediate SARS-CoV-2 entry. Moreover, we reveal that SARS-CoV-2 proteins inhibit activation of the interferon pathway through the mitochondrial protein mitochondrial antiviral-signaling protein (MAVS) and the methyltransferase SET domain containing 2, histone lysine methyltransferase (SETD2). We propose 111 potential drugs for the clinical treatment of coronavirus disease 2019 (COVID-19) and identify three compounds that significantly inhibit the replication of SARS-CoV-2. The proximity labeling map of SARS-CoV-2 and humans provides a resource for elucidating the mechanisms of viral infection and developing drugs for COVID-19 treatment.

Allosteric inhibition of SARS-CoV-2 3CL protease by colloidal bismuth subcitrate

The SARS-CoV-2 3-chymotrypsin-like protease (3CLpro or Mpro) is a key cysteine protease for viral replication and transcription, making it an attractive target for antiviral therapies to combat the COVID-19 disease. Here, we demonstrate that bismuth drug colloidal bismuth subcitrate (CBS) is a potent inhibitor for 3CLpro in vitro and in cellulo. Rather than targeting the cysteine residue at the catalytic site, CBS binds to an allosteric site and results in dissociation of the 3CLpro dimer and proteolytic dysfunction. Our work provides direct evidence that CBS is an allosteric inhibitor of SARS-CoV-2 3CLpro.

Colloidal bismuth subcitrate (CBS) is an allosteric inhibitor of 3-chymotrypsin-like protease (3CLpro) in SARS-CoV-2. CBS binding causes dimeric 3CLpro dissociation and proteolytic dysfunction, leading to the suppression of SARS-CoV-2 replication.

Mechanical activation of spike fosters SARS-CoV-2 viral infection

The outbreak of SARS-CoV-2 (SARS2) has caused a global COVID-19 pandemic. The spike protein of SARS2 (SARS2-S) recognizes host receptors, including ACE2, to initiate viral entry in a complex biomechanical environment. Here, we reveal that tensile force, generated by bending of the host cell membrane, strengthens spike recognition of ACE2 and accelerates the detachment of spike's S1 subunit from the S2 subunit to rapidly prime the viral fusion machinery. Mechanistically, such mechano-activation is fulfilled by force-induced opening and rotation of spike's receptor-binding domain to prolong the bond lifetime of spike/ACE2 binding, up to 4 times longer than that of SARS-S binding with ACE2 under 10 pN force application, and subsequently by force-accelerated S1/S2 detachment which is up to ~10³ times faster than that in the no-force condition. Interestingly, the SARS2-S D614G mutant, a more infectious variant, shows 3-time stronger force-dependent ACE2 binding and 35-time faster force-induced S1/S2 detachment. We also reveal that an anti-S1/S2 non-RBD-blocking antibody that was derived from convalescent COVID-19 patients with potent neutralizing capability can reduce S1/S2 detachment by 3 × 10⁶ times under force. Our study sheds light on the mechano-chemistry of spike activation and on developing a non-RBD-blocking but S1/S2-locking therapeutic strategy to prevent SARS2 invasion.

SARS-CoV-2 NSP12 Protein Is Not an Interferon-β Antagonist

The coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is bringing an unprecedented health crisis to the world. To date, our understanding of the interaction between SARS-CoV-2 and host innate immunity is still limited. Previous studies reported that SARS-CoV-2 nonstructural protein 12 (NSP12) was able to suppress interferon-β (IFN-β) activation in IFN-β promoter luciferase reporter assays, which provided insights into the pathogenesis of COVID-19. In this study, we demonstrated that IFN-β promoter-mediated luciferase activity was reduced during coexpression of NSP12. However, we could show NSP12 did not affect IRF3 or NF-κB activation. Moreover, IFN-β production induced by Sendai virus (SeV) infection or other stimulus was not affected by NSP12 at mRNA or protein level. Additionally, the type I IFN signaling pathway was not affected by NSP12, as demonstrated by the expression of interferon-stimulated genes (ISGs). Further experiments revealed that different experiment systems, including protein tags and plasmid backbones, could affect the readouts of IFN-β promoter luciferase assays. In conclusion, unlike as previously reported, our study showed SARS-CoV-2 NSP12 protein is not an IFN-β antagonist. It also rings the alarm on the general usage of luciferase reporter assays in studying SARS-CoV-2. IMPORTANCE Previous studies investigated the interaction between SARS-CoV-2 viral proteins and interferon signaling and proposed that several SARS-CoV-2 viral proteins, including NSP12, could suppress IFN-β activation. However, most of these results were generated from IFN-β promoter luciferase reporter assay and have not been validated functionally. In our study, we found that, although NSP12 could suppress IFN-β promoter luciferase activity, it showed no inhibitory effect on IFN-β production or its downstream signaling. Further study revealed that contradictory results could be generated from different experiment systems. On one hand, we demonstrated that SARS-CoV-2 NSP12 could not suppress IFN-β signaling. On the other hand, our study suggests that caution needs to be taken with the interpretation of SARS-CoV-2-related luciferase assays.

Generation of WAe001-A-58 human embryonic stem cell line with inducible expression of the SARS-CoV-2 nucleocapsid protein

Excessive prostaglandin E₂ (PGE₂) is the key pathological basis for COVID-19 and a Celebrex treatment of hospitalized COVID-19 patients with comorbidities led to 100% discharged rate and zero death (Hong et al. 2020). It is also suggested that SARS-CoV-2 infected multiple organs and the SARS-CoV nucleocapsid (N) protein transcriptionally drives the expression of the host COX-2 gene. In order to test whether SARS-CoV-2 N protein activates COX-2 transcription in multiple human relevant cell types, an expression inducible human embryonic stem cell line was generated by piggyBac transposon system. This cell line maintained its pluripotency, differentiation potentials, normal morphology and karyotype.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) membrane (M) protein inhibits type I and III interferon production by targeting RIG-I/MDA-5 signaling

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has quickly spread worldwide and has affected more than 10 million individuals. A typical feature of COVID-19 is the suppression of type I and III interferon (IFN)-mediated antiviral immunity. However, the molecular mechanism by which SARS-CoV-2 evades antiviral immunity remains elusive. Here, we reported that the SARS-CoV-2 membrane (M) protein inhibits the production of type I and III IFNs induced by the cytosolic dsRNA-sensing pathway mediated by RIG-I/MDA-5-MAVS signaling. In addition, the SARS-CoV-2 M protein suppresses type I and III IFN induction stimulated by SeV infection or poly (I:C) transfection. Mechanistically, the SARS-CoV-2 M protein interacts with RIG-I, MAVS, and TBK1, thus preventing the formation of the multiprotein complex containing RIG-I, MAVS, TRAF3, and TBK1 and subsequently impeding the phosphorylation, nuclear translocation, and activation of IRF3. Consequently, ectopic expression of the SARS-CoV-2 M protein facilitates the replication of vesicular stomatitis virus. Taken together, these results indicate that the SARS-CoV-2 M protein antagonizes type I and III IFN production by targeting RIG-I/MDA-5 signaling, which subsequently attenuates antiviral immunity and enhances viral replication. This study provides insight into the interpretation of SARS-CoV-2-induced antiviral immune suppression and illuminates the pathogenic mechanism of COVID-19.

[MRI histogram texture analysis of lateral pterygoid muscle in patients with temporomandibular disorders]

Objective: To evaluate the functional changes of lateral pterygoid muscle (LPM) in the patients with temporomandibular disorders (TMD) using histogram texture analysis. Methods: A total of 28 TMD patients, including 15 males and 13 females, aged (26.2±12.1) years (15-62 years), were enrolled in the outpatient clinic of Department of Radiology, Hainan Hospital of Chinese PLA General Hospital from May 2016 to April 2020. At the same time, 13 volunteers with normal temporomandibular joint [6 males and 7 females, aged (23.5±3.3) years (20-30) years] were recruited. All participants were performed with temporomandibular joint MRI scan, and the subjects were classified into 3 groups according to the disc displacement: TMD with disc without displacement (TMD-DwoD), TMD with disc displacement without reduction (TMD-DDwoR) and NC with disc displacement without reduction (NC-DwoD) for each temporomandibular joint. The area, signal intensity, coefficient of variation (CV) of mean signal intensity and histogram texture of the superior belly of LPM (SBLPM) and inferior belly of LPM (IBLPM) were measured using regions of interests. Results: The area of SILPM presented significantly smaller in TMD-DwoD [(67.36±30.23) mm²] compared with that in NC-DwoD [(91.42±45.01) mm²] (P<0.05) and in TMD-DDwoR group [(72.27±37.53) mm²] (P>0.05). The mean signal intensity of SBLPM was identified significantly higher in TMD-DwoD (304.20±29.90) and TMD-DDwoR (315.06±40.20) compared with that in NC-DwoD (269.79±25.54) (P<0.05). The CV of mean signal intensity of SBLPM presented significantly higher in TMD-DwoD (8.89±2.60) compared with that in NC-DwoD (6.76±1.82) and TMD-DDwoR (7.63±1.62) (P<0.05). The skew and kurtosis showed no significantly differences among three groups for SBLPM (P>0.05). The mean signal intensity and CV for IBLPM presented significantly higher in TMD-DwoD (286.69±23.48 and 9.96±2.24, respectively) and TMD-DDwoR (275.98±30.55 and 10.25±1.96, respectively) compared with that in NC-DwoD (243.56±17.04 and 8.49±1.94, respectively) (P<0.05). The skewness showed significantly lower in TMD-DwoD (0.90±0.94) and TMD-DDwoR (0.73±0.97) compared with that in NC-DwoD (1.40±1.03) (P<0.05). The area and kurtosis for IBLPM showed no significant differences among three groups (P>0.05). Conclusions: The MR histogram texture analysis could primarily be considered as a tool to evaluate the LPM function in TMD patients.

Lung Cancer Cell-Derived Secretome Mediates Paraneoplastic Inflammation and Fibrosis in Kidney in Mice

Simple Summary

Paraneoplastic nephrotic syndrome is a complication arising in lung cancer patients. In the present study, we established an LLC1 cell orthotopic xenograft C57BL/6 mice model to translation paraneoplastic nephrotic syndrome (PNS). The pathological aspects of PNS were characterized in TGF-β signaling-engaged renal fibrosis, and renal inflammation with IL-6 expression in kidney. To reveal how the lung cancer cells remotely drive pathogenic progression, secretome derived from LLC1 cells and A549 cells were proteomically profiled. Additionally, the secretome profiling was subjected to diseases and biofunctions assessment by Ingenuity Pathway analysis (IPA). As matter of secretome profiling and IPA prediction, the Fibronectin, C1r, and C1s are potential of nephrotoxicity linked to paraneoplastic effects on glomerular pathogenesis in these lung cancer mice.

Abstract

Kidney failure is a possible but rare complication in lung cancer patients that may be caused by massive tumor lysis or a paraneoplastic effect. Clinical case reports have documented pathological characteristics of paraneoplastic syndrome in glomeruli, but are short of molecular details. When Lewis lung carcinoma 1 (LLC1) cells were implanted in mice lungs to establish lung cancer, renal failure was frequently observed two weeks post orthotopic xenograft. The high urinary albumin-to-creatinine ratio (ACR) was diagnosed as paraneoplastic nephrotic syndrome in those lung cancer mice. Profiling the secretome of the lung cancer cells revealed that the secretory proteins were potentially nephrotoxic. The nephrotoxicity of lung cancer-derived secretory proteins was tested by examining the pathogenic effects of 1 × 10⁶, 2 × 10⁶, and 5 × 10⁶ LLC1 cell xenografts on the pathogenic progression in kidneys. Severe albuminuria was present in the mice that received 5 × 10⁶ LLC1 cells implantation, whereas 10⁶ cell and 2 × 10⁶ cell-implanted mice have slightly increased albuminuria. Pathological examinations revealed that the glomeruli had capillary loop collapse, tumor antigen deposition in glomeruli, and renal intratubular casts. Since IL-6 and MCP-1 are pathologic markers of glomerulopathy, their distributions were examined in the kidneys of the lung cancer mice. Moderate to severe inflammation in the kidneys was correlated with increases in the number of cells implanted in the mice, which was reflected by renal IL-6 and MCP-1 levels, and urine ACR. TGF-β signaling-engaged renal fibrosis was validated in the lung cancer mice. These results indicated that lung cancer cells could provoke inflammation and activate renal fibrosis.

Increasing host cellular receptor-angiotensin-converting enzyme 2 expression by coronavirus may facilitate 2019-nCoV (or SARS-CoV-2) infection

The ongoing outbreak of a new coronavirus (2019-nCoV, or severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2]) has caused an epidemic of the acute respiratory syndrome known as coronavirus disease (COVID-19) in humans. SARS-CoV-2 rapidly spread to multiple regions of China and multiple other countries, posing a serious threat to public health. The spike (S) proteins of SARS-CoV-1 and SARS-CoV-2 may use the same host cellular receptor, angiotensin-converting enzyme 2 (ACE2), for entering host cells. The affinity between ACE2 and the SARS-CoV-2 S protein is much higher than that of ACE2 binding to the SARS-CoV S protein, explaining why SARS-CoV-2 seems to be more readily transmitted from human to human. Here, we report that ACE2 can be significantly upregulated after infection of various viruses, including SARS-CoV-1 and SARS-CoV-2, or by the stimulation with inflammatory cytokines such as interferons. We propose that SARS-CoV-2 may positively induce its cellular entry receptor, ACE2, to accelerate its replication and spread; high inflammatory cytokine levels increase ACE2 expression and act as high-risk factors for developing COVID-19, and the infection of other viruses may increase the risk of SARS-CoV-2 infection. Therefore, drugs targeting ACE2 may be developed for the future emerging infectious diseases caused by this cluster of coronaviruses.

[Evaluation of histological changes of retrodisc attached tissue in patients with temporomandibular disorders by texture analysis: a pilot study]

Objective: To evaluate the histological changes of the retrodiscal tissue in the patients with temporomandibular disorders (TMD). Methods: Thirty-three TMD patients were performed with temporomandibular joint (TMJ) MRI examinations from April 2018 to April 2020 in TMD clinic, Hainan Hospital of General Hospital of Chinese PLA. The patients groups were classified according to the disc position as follows: normal position (NP) (29 TMJ), disk displacement with reduction (DDwR) (14 TMJ) and disk displacement without reduction (DDwoR) (23 TMJ). The gray-level co-occurrence matrix (GLCM) analysis was applied with the retrodiscal tissue on the open oblique sagittal proton weighted images. The texture parameters included as follows: angular second moment (ASM), contrast, correlation, inverse difference moment (IDM) and entropy. The statistical methods mainly included Kruskal-Wallis H test, one-way analysis of variance and receiver operating characteristic curve (ROC), to analyze the texture characteristic parameters of the retrodiscal tissue are statistically significant. Results: There was no significant difference of the retrodiscal tissue's ASM, contrast, correlation and IDM among 3 groups (P>0.05). The entropy in NP group (3.98±0.44) and DDwR group (4.20±0.52) presented significant higher than that in DDwoR group (3.70±0.38) (P<0.05). ROC analysis for the entropy demonstrated that the area under the curve was 0.70 when differentiating NP and DDwR (cut-off value 0.38, sensitivity 82.61%, specificity 55.17%), and was 0.79 when differentiating DDwR and DDwoR (cut-off value 0.47, sensitivity 82.61%, specificity 64.29%). Conclusions: Texture entropy could be primarily used to evaluate the histological and pathological changes of the retrodiscal tissue in the TMD patients.

[Numerical simulation of intranasal airflow in nasal numerical models with nasal septum perforations of different locations and sizes]

Objective: To investigate the effect of nasal septum perforation (SP) with different locations and sizes on nasal airflow by means of numerical simulation. Methods: Two healthy persons with normal nasal anatomy were enrolled in this study, including a 45 years old male (case 1) and a 36 years old female (case 2). Nasal CT data was used as the basis to create nasal airway numerical models of nasal SP with different locations (anterior caudal, central caudal, posterior caudal and anterior cranial) and sizes (diameter of 10 mm and 5 mm respectively). The inspiratory airflow characteristics (nasal cavity volume, nasal cavity wall area, pressure, nasal resistance, temperature, airflow velocity, wall shear stress, airflow-rate partitioning and vortex) of these nasal airway numerical models were simulated and analyzed. Pearson correlation analysis was performed between nasal resistances, airflow temperature and nasal cavity wall area. Results: In terms of pressure and nose resistance, the anterior caudal and larger size SP lead to more obvious variation of pressure distribution, and increased nasal resistance was especially found in the nasal cavity with anterior and medium caudal SP. In terms of temperature, the anterior (caudal and cranial) and larger size SP had significant effect on local temperature gradient as same as the anterior cranial and smaller size SP. Nasal heating efficiency was lower in nasal model with the anterior and larger size SP than that in the normal model. The temperature difference from the nostril to the end of nasal septum had positive correlation with nasal cavity wall area (R(2) value of case 1 and case 2 was 0.69, 0.41, respectively, all P<0.01). In terms of airflow velocity, the anterior caudal and cranial SP had more significant effect on the average airflow velocity in the nasal cavity. The anterior and medium caudal SP could make the airflow distribution in the asymmetric bilateral nasal cavity more unbalanced compared to the bilateral symmetrical nasal models. The anterior and medium SP resulted in a more pronounced vortex distribution than the posterior SP. Conclusions: The effect of SP on nasal cavity is related to its location and size. The anterior and larger size SP shows more negative influence on intranasal pressure, nasal resistance, heat transmission efficiency, airflow-rate partitioning than the posterior and smaller size SP.

Increasing host cellular receptor-angiotensin-converting enzyme 2 expression by coronavirus may facilitate 2019-nCoV (or SARS-CoV-2) infection

The ongoing outbreak of a new coronavirus (2019‐nCoV, or severe acute respiratory syndrome coronavirus 2 [SARS‐CoV‐2]) has caused an epidemic of the acute respiratory syndrome known as coronavirus disease (COVID‐19) in humans. SARS‐CoV‐2 rapidly spread to multiple regions of China and multiple other countries, posing a serious threat to public health. The spike (S) proteins of SARS‐CoV‐1 and SARS‐CoV‐2 may use the same host cellular receptor, angiotensin‐converting enzyme 2 (ACE2), for entering host cells. The affinity between ACE2 and the SARS‐CoV‐2 S protein is much higher than that of ACE2 binding to the SARS‐CoV S protein, explaining why SARS‐CoV‐2 seems to be more readily transmitted from human to human. Here, we report that ACE2 can be significantly upregulated after infection of various viruses, including SARS‐CoV‐1 and SARS‐CoV‐2, or by the stimulation with inflammatory cytokines such as interferons. We propose that SARS‐CoV‐2 may positively induce its cellular entry receptor, ACE2, to accelerate its replication and spread; high inflammatory cytokine levels increase ACE2 expression and act as high‐risk factors for developing COVID‐19, and the infection of other viruses may increase the risk of SARS‐CoV‐2 infection. Therefore, drugs targeting ACE2 may be developed for the future emerging infectious diseases caused by this cluster of coronaviruses.

Virus infection and inflammatory cytokines can stimulate angiotensin‐converting enzyme 2 (ACE2) expression. ACE2 is upregulated by the activation of RNA‐sensing pathways. ACE2 is a novel interferon‐stimulated gene (ISG). The increase in ACE2 induced by various viruses and inflammatory cytokines may facilitate severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection and spreading.

Long-term coexistence of SARS-CoV-2 with antibody response in COVID-19 patients

Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection causing coronavirus disease 2019 (COVID‐19) has spread worldwide. Whether antibodies are important for the adaptive immune responses against SARS‐CoV‐2 infection needs to be determined. Here, 26 cases of COVID‐19 in Jinan, China, were examined and shown to be mild or with common clinical symptoms, and no case of severe symptoms was found among these patients. Strikingly, a subset of these patients had SARS‐CoV‐2 and virus‐specific IgG coexist for an unexpectedly long time, with two cases for up to 50 days. One COVID‐19 patient who did not produce any SARS‐CoV‐2–bound IgG successfully cleared SARS‐CoV‐2 after 46 days of illness, revealing that without antibody‐mediated adaptive immunity, innate immunity alone may still be powerful enough to eliminate SARS‐CoV‐2. This report may provide a basis for further analysis of both innate and adaptive immunity in SARS‐CoV‐2 clearance, especially in nonsevere cases.

1.

SARS‐CoV‐2 could exist in patients who have virus‐specific IgG for an unexpectedly long time (36‐50 days).

2.

One COVID‐19 patient who did not produce any SARS‐CoV‐2–specific IgG successfully cleared SARS‐CoV‐2 after 46 days of illness.

3.

Innate immunity might be powerful enough to eliminate SARS‐CoV‐2.

Pin1 coordinates HDAC6 upregulation with cell migration in lung cancer cells

Histone deacetylase 6 (HDAC6) controls many cellular processes via its catalyzing deacetylation of downstream substrates or interacting with its partner proteins. Dysregulation of HDAC6 signaling links to many diseases. Our previous study has been reported peptidyl-prolyl cis/trans isomerase, and NIMA-interacting 1 (Pin1) involving in HDAC6-mediated cell motility. To gain insight into precisely coordination of HDAC6 and Pin1 in cell migration, shRNA-mediated gene silencing and ectopic expression were applied to manipulate protein expression level to evaluate relationship between HDAC6 and Pin1 expression. Quantitative RT-PCR and the cycloheximide (CHX) chase assay resulted in HDAC6 expression is correlated with Pin1 level in H1299 cells. It hints that the Pin1 increases HDAC6 expression through increased transcripts and posttranslational stabilization. Furthermore, wound healing assay and transwell invasion assay evidenced the contribution of Pin1 on cell motility in H1299 cells. Our data suggest that Pin1 acts as an important regulator to manage HDAC6 expression for cell motility in lung cancer cells.

A novel transcript isoform of STING that sequesters cGAMP and dominantly inhibits innate nucleic acid sensing

STING is a core adaptor in innate nucleic acid sensing in mammalian cells, on which different sensing pathways converge to induce type I interferon (IFN) production. Particularly, STING is activated by 2'3'-cGAMP, a cyclic dinucleotide containing mixed phosphodiester linkages and produced by cytoplasmic DNA sensor cGAS. Here, we reported on a novel transcript isoform of STING designated STING-β that dominantly inhibits innate nucleic acid sensing. STING-β without transmembrane domains was widely expressed at low levels in various human tissues and viral induction of STING-β correlated inversely with IFN-β production. The expression of STING-β declined in patients with lupus, in which type I IFNs are commonly overproduced. STING-β suppressed the induction of IFNs, IFN-stimulated genes and other cytokines by various immunostimulatory agents including cyclic dinucleotides, DNA, RNA and viruses, whereas depletion of STING-β showed the opposite effect. STING-β interacted with STING-α and antagonized its antiviral function. STING-β also interacted with TBK1 and prevented it from binding with STING-α, TRIF or other transducers. In addition, STING-β bound to 2'3'-cGAMP and impeded its binding with and activation of STING-α, leading to suppression of IFN-β production. Taken together, STING-β sequesters 2'3'-cGAMP second messenger and other transducer molecules to inhibit innate nucleic acid sensing dominantly.

[Application on the clinical effect of immediate repair of part helix defect with flap on post aurem and mastoid region]

Objective: To investigate the clinical effect of the flap on post aurem and mastoid region on immediate repair of part helix defect. Method: Fifteen patients with part helix defect were immediately repaired using the flap on post aurem and mastoid region. Firstly, the skin tissue above the defect of the helix was used as the pedicle. The flap was drawn toward the post aurem and mastoid region closing to the auriculocephalic angle. The flap was generally 3-4 cm long and at least 1 cm wide. Secondly, the flap was lifted on the perichondrium, and the structure of the helix was formed by upward rotation of the flap to repair the defect of the helix. Finally, the flap was sutured to repair the helix defect. Result: Fifteen cases were applied with this method to repair immediately the defect in the emergency environment. The sizes of helix contour were satisfactory and the auriculocephalic angles had not changed. The ear shape was stable after 1 to 3 months of followup. Conclusion: The flap on post aurem and mastoid region could immediately repair the part helix defect. It has the advantages of simple operation, high flap survival rate and one-time satisfactory shape..

Inflammasome activation and Th17 responses

Immune sensing of exogenous molecules from microbes (e.g., pathogen-associated molecular patterns) and nonmicrobial molecules (e.g., asbestos, alum, and silica), as well as endogenous damage-associated molecular patterns (e.g., ATP, uric acid crystals, and amyloid A) activates innate immunity by inducing immune-related genes, including proinflammatory cytokines, which further facilitate the development of adaptive immunity. The roles of transcriptional responses downstream of immune sensing have been widely characterized in informing adaptive immunity; however, few studies focus on the effect of post-translational responses on the modulation of adaptive immune responses. Inflammasomes activated by the previously described endo- and exogenous stimuli autocatalytically induce intracellular pro-caspase-1, which cleaves the inactive precursors of interleukin-1β (IL-1β) and IL-18 into bioactive proinflammatory cytokines. IL-1β and IL-18 not only contribute to the host defense against infections by activating phagocytes, such as monocytes, macrophages, dendritic cells, and neutrophils, but also induce T-helper 17 (Th17)- and Th1-mediated adaptive immune responses. In synergy with IL-6 and IL-23, IL-1β activates IL-1 receptor (IL-1R) signaling to drive the differentiation of IL-17-producing Th17 cells, which not only play critical roles in host protective immunity to infections of bacteria, fungi, and certain viruses but also participate in the pathology of inflammatory disorders and tumorigenesis. Consequently, targeting inflammasomes and IL-1/IL-1R signaling may effectively improve the treatment of Th17-associated disorders, such as autoinflammatory diseases and cancers, thereby providing novel insights into drug development.

Inhibition of FAK Signaling Elicits Lamin A/C-Associated Nuclear Deformity and Cellular Senescence

Focal adhesion kinase (FAK) is a non-receptor kinase that facilitates tumor aggressiveness. The effects of FAK inhibition include arresting proliferation, limiting metastasis, and inhibiting angiogenesis. PF-573228 is an ATP-competitive inhibitor of FAK. Treating lung cancer cells with PF-573228 resulted in FAK inactivation and changes in the expressions of lamin A/C and nuclear deformity. Since lamin A/C downregulation or deficiency was associated with cellular senescence, the senescence-associated β-galactosidase (SA-β-gal) assay was used to investigate whether PF-573228 treatment drove cellular senescence, which showed more SA-β-gal-positive cells in culture. p53 is known to play a pivotal role in mediating the progression of cellular senescence, and the PF-573228-treated lung cancer cells resulted in a higher p53 expression level. Subsequently, the FAK depletion in lung cancer cells was employed to confirm the role of FAK inhibition on cellular senescence. FAK depletion and pharmacological inhibition of lung cancer cells elicited similar patterns of cellular senescence, lamin A/C downregulation, and p53 upregulation, implying that FAK signaling is associated with the expression of p53 and the maintenance of lamin A/C levels to shape regular nuclear morphology and manage anti-senescence. Conversely, FAK inactivation led to p53 upregulation, disorganization of the nuclear matrix, and consequently cellular senescence. Our data suggest a new FAK signaling pathway, in that abolishing FAK signaling can activate the senescence program in cells. Triggering cellular senescence could be a new therapeutic approach to limit tumor growth.

The Interplay Between Pattern Recognition Receptors and Autophagy in Inflammation

Pattern recognition receptors (PRRs) are sensors of exogenous and endogenous "danger" signals from pathogen-associated molecular patterns (PAMPs), and damage associated molecular patterns (DAMPs), while autophagy can respond to these signals to control homeostasis. Almost all PRRs can induce autophagy directly or indirectly. Toll-like receptors (TLRs), Nod-like receptors (NLRs), retinoic acid-inducible gene-I-like receptors (RLRs), and cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS)-stimulator of interferon genes (STING) pathway can induce autophagy directly through Beclin-1 or LC3-dependent pathway, while the interactions with the receptor for advanced glycation end products (RAGE)/high mobility group box 1 (HMGB1), CD91/Calreticulin, and TLRs/HSPs are achieved by protein, Ca2⁺, and mitochondrial homeostasis. Autophagy presents antigens to PRRs and helps to clean the pathogens. In addition, the induced autophagy can form a negative feedback regulation of PRRs-mediated inflammation in cell/disease-specific manner to maintain homeostasis and prevent excessive inflammation. Understanding the interaction between PRRs and autophagy in a specific disease will promote drug development for immunotherapy. Here, we focus on the interactions between PRRs and autophagy and how they affect the inflammatory response.

Pin1 Is Involved in HDAC6-mediated Cancer Cell Motility

Histone deacetylase 6 (HDAC6), a member of the HDAC enzymes, has been reported to play substantial roles in many cellular processes. Evidence shows that deregulation of HDAC6 may be involved in the progression of some cancers, neurodegenerative diseases, and inflammatory disorders. However, little is known regarding the effect of post-translational modification of HDAC6 on cellular localization and biological functions. In the present study, we identified four phosphorylation sites on HDAC6 under normal conditions by mass spectrometry analysis. Two phosphorylation sites, pSer22 and pSer412, are recognized as Pin1 (peptidyl-prolyl cis/trans isomerase NIMA-interacting 1) substrates. Pin1 can interact with HDAC6 and be involved in HDAC6-mediated cell motility. Pin1 depletion abrogates HDAC6-induced cell migration and invasion in H1299 lung cancer cells. The findings of this study suggest that Pin1 might regulate HDAC6-mediated cell motility through alteration of protein conformation and function. Our results indicate the complexity of activity regulation between HDAC6 and Pin1, expanding knowledge regarding the multifunctional roles of Pin1 in tumorigenesis and cancer progression.

Inhibition of AIM2 inflammasome activation by a novel transcript isoform of IFI16

Mouse p202 is a disease locus for lupus and a dominant-negative inhibitor of AIM2 inflammasome activation. A human homolog of p202 has not been identified so far. Here, we report a novel transcript isoform of human IFI16-designated IFI16-β, which has a domain architecture similar to that of mouse p202. Like p202, IFI16-β contains two HIN domains, but lacks the pyrin domain. IFI16-β is ubiquitously expressed in various human tissues and cells. Its mRNA levels are also elevated in leukocytes of patients with lupus, virus-infected cells, and cells treated with interferon-β or phorbol ester. IFI16-β co-localizes with AIM2 in the cytoplasm, whereas IFI16-α is predominantly found in the nucleus. IFI16-β interacts with AIM2 to impede the formation of a functional AIM2-ASC complex. In addition, IFI16-β sequesters cytoplasmic dsDNA and renders it unavailable for AIM2 sensing. Enforced expression of IFI16-β inhibits the activation of AIM2 inflammasome, whereas knockdown of IFI16-β augments interleukin-1β secretion triggered by dsDNA but not dsRNA Thus, cytoplasm-localized IFI16-β is functionally equivalent to mouse p202 that exerts an inhibitory effect on AIM2 inflammasome.

[Effect of dentin proteoglycans on the stability of resin-dentin bonds against artificial saliva storage]

Objective: To investigate the potential effect of proteoglycans (PG) and glycosaminoglycans (GAG) on the stability of resin-dentin bonds against artificial saliva storage. Methods: Seventy-two extracted molars were used to obtain standard dentin bonding surface, and the specimens were etched for 15 s with 37% phosphoric acid and divided into three groups using a table of random number. Then the three groups undergone different incubating procedures as follow: specimens in chondroitinase ABC (C-ABC) group were incubated with C-ABC, specimens in trypsin (TRY) group were incubated with trypsin, and specimens in the control group were incubated with deionized water. All specimens were incubated at 37 ℃ for 48 h in the oscillators. Then specimens in each group were randomly assigned into three subgroups (n=8) as follows: immediate control subgroup, aging subgroups with artificial saliva storage for 6 months and 12 months. Microtensile bond strength (μTBS), fracture mode, bonding interface morphology and nanoleakage were evaluated. Results: Immediately and with artificial saliva storage for 6 months and 12 mouths, the μTBS of TRY group ([49.04±3.57], [37.01±3.21] and [35.27±3.56] MPa) were significantly higher than those in the control group ([40.71±3.32], [28.87±2.34] and [24.20±2.07] MPa) (P<0.05). The immediate μTBS of C-ABC group ([32.94±2.45] MPa) was significantly lower than that of the control group (P<0.05). While with artificial saliva storage for 6 months and 12 mouths, the μTBS of C-ABC group ([26.46±2.45] and [22.50±2.58] MPa) were no differences with those of the control group (P>0.05). The ratio of cohesive fracture increased with the extension of aging time. Some narrow gaps were found in hybrid layer of the control group with artificial saliva storage for 6 months and 12 mouths. Conclusions: Removal of PG increased the μTBS and durable bonds to dentin, while removal of GAG decreased the μTBS, however, it can be of help to create more durable bonds to dentin.

[Advances in therapy of auricular keloid]

Auricularis keloids are the keloids locating on the earlobe and helix which often caused by ear piercing, burn wound and skin injury. Because of its high recurrence, the treatment of auricularis keloids is troublesome to ENT doctors. In the past, clinicians harvested some achievements by combining surgical therapy, drug therapy and physical therapy. Keloid therapies were reviewed in this article.

Investigation on the nasal airflow characteristics of anterior nasal cavity stenosis

We used a computational fluid dynamics (CFD) model to study the inspiratory airflow profiles of patients with anterior nasal cavity stenosis who underwent curative surgery, by comparing pre- and postoperative airflow characteristics. Twenty patients with severe anterior nasal cavity stenosis, including one case of bilateral stenosis, underwent computed tomography (CT) scans for CFD modelling. The pre- and postoperative airflow characteristics of the nasal cavity were simulated and analyzed. The narrowest area of the nasal cavity in all 20 patients was located within the nasal valve area, and the mean cross-sectional area increased from 0.39 cm² preoperative to 0.78 cm² postoperative (P<0.01). Meanwhile, the mean airflow velocity in the nasal valve area decreased from 6.19 m/s to 2.88 m/s (P<0.01). Surgical restoration of the nasal symmetry in the bilateral nasal cavity reduced nasal resistance in the narrow sides from 0.24 Pa^.s/mL to 0.11 Pa^.s/mL (P<0.01). Numerical simulation of the nasal cavity in patients with anterior nasal cavity stenosis revealed structural changes and the resultant patterns of nasal airflow. Surgery achieved balanced bilateral nasal ventilation and decreased nasal resistance in the narrow region of the nasal cavity. The correction of nasal valve stenosis is not only indispensable for reducing nasal resistance, but also the key to obtain satisfactory curative effect.

Novel remodeling of the mouse heart mitochondrial proteome in response to acute insulin stimulation

BACKGROUND AND AIM

Mitochondrial dysfunction contributes to the pathophysiology of diabetic cardiomyopathy. The aim of this study was to investigate the acute changes in the mitochondrial proteome in response to insulin stimulation.

METHODS AND RESULTS

Cardiac mitochondria from C57BL/6 mice after insulin stimulation were analyzed using two-dimensional fluorescence difference gel electrophoresis. MALDI-TOF MS/MS was utilized to identify differences. Two enzymes involved in metabolism and four structural proteins were identified. Succinyl-CoA ligase [ADP forming] subunit beta was identified as one of the differentially regulated proteins. Upon insulin stimulation, a relatively more acidic isoform of this protein was increased by 53% and its functional activity was decreased by ∼32%.

CONCLUSIONS

This proteomic remodeling in response to insulin stimulation may play an important role in the normal and diabetic heart.

Suppression of type I and type III IFN signalling by NSs protein of severe fever with thrombocytopenia syndrome virus through inhibition of STAT1 phosphorylation and activation

Severe fever with thrombocytopenia syndrome virus (SFTSV) is an emerging tick-borne pathogen causing significant morbidity and mortality in Asia. NSs protein of SFTSV is known to perturb type I IFN induction and signalling, but the mechanism remains to be fully understood. Here, we showed the suppression of both type I and type III IFN signalling by SFTSV NSs protein is mediated through inhibition of STAT1 phosphorylation and activation. Infection with live SFTSV or expression of NSs potently suppressed IFN-stimulated genes but not NFkB activation. NSs was capable of counteracting the activity of IFN-α1, IFN-β, IFN-λ1 and IFN-λ2. Mechanistically, NSs associated with STAT1 and STAT2, mitigated IFN-β-induced phosphorylation of STAT1 at S727, and reduced the expression and activity of STAT1 protein in IFN-β-treated cells, resulting in the inhibition of STAT1 and STAT2 recruitment to IFNstimulated promoters. Taken together, SFTSV NSs protein is an IFN antagonist that suppresses phosphorylation and activation of STAT1.

Five in one therapy for graded treatment of haemophilic arthritis

INTRODUCTION

Haemophilic arthritis is the most universal clinical appearance of haemophilia. Treatment of this disease has become an important and difficult issue worldwide until recently.

OBJECTIVE

To investigate the efficacy and safety of five in one therapy for graded treatment of haemophilic arthritis.

METHODS

Haemophilic arthritis was classified into grades I-IV according to severity and the standards of De Palma and Cotler. Under no application of FVIII/FIX replacement therapy state, the effect of five in one therapy (intra-articular cavity drug injection, oral drug preparation, physiotherapy, and prevention of haemorrhage and infection evoked by puncture) was observed in 1527 affected joints of 750 cases of haemophilic arthritis.

RESULTS

After 20 days treatment, all grade I and II, 94.98% of grade III and 56.16% of grade IV affected joints were completely relieved; 5.02% of grade III and 41.47% of grade IV affected joints were basically relieved; and 2.38% of grade IV were partially relieved. This resulted in short-term complete and basic relief of 98.56% (1505/1527) of all affected joints. After follow-up of 1-6 years, 86.97% of the affected joints were completely relieved, without any adverse reaction or complication.

CONCLUSION

The results suggest that five in one therapy is safe and effective for treatment of haemophilic arthritis, and provides a convenient, cost-effective way of preventing and treating deformity caused by haemophilic arthritis.

Nucleic acid-induced antiviral immunity in invertebrates: an evolutionary perspective

Nucleic acids derived from viral pathogens are typical pathogen associated molecular patterns (PAMPs). In mammals, the recognition of viral nucleic acids by pattern recognition receptors (PRRs), which include Toll-like receptors (TLRs) and retinoic acid-inducible gene (RIG)-I-like receptors (RLRs), induces the release of inflammatory cytokines and type I interferons (IFNs) through the activation of nuclear factor κB (NF-κB) and interferon regulatory factor (IRF) 3/7 pathways, triggering the host antiviral state. However, whether nucleic acids can induce similar antiviral immunity in invertebrates remains ambiguous. Several studies have reported that nucleic acid mimics, especially dsRNA mimic poly(I:C), can strongly induce non-specific antiviral immune responses in insects, shrimp, and oyster. This behavior shows multiple similarities to the hallmarks of mammalian IFN responses. In this review, we highlight the current understanding of nucleic acid-induced antiviral immunity in invertebrates. We also discuss the potential recognition and regulatory mechanisms that confer non-specific antiviral immunity on invertebrate hosts.