Transcriptional and Proteomic Characterization of Telomere-Induced Senescence in a Human Alveolar Epithelial Cell Line

Cellular senescence due to telomere dysfunction has been hypothesized to play a role in age-associated diseases including idiopathic pulmonary fibrosis (IPF). It has been postulated that paracrine mediators originating from senescent alveolar epithelia signal to surrounding mesenchymal cells and contribute to disease pathogenesis. However, murine models of telomere-induced alveolar epithelial senescence fail to display the canonical senescence-associated secretory phenotype (SASP) that is observed in senescent human cells. In an effort to understand human-specific responses to telomere dysfunction, we modeled telomere dysfunction-induced senescence in a human alveolar epithelial cell line. We hypothesized that this system would enable us to probe for differences in transcriptional and proteomic senescence pathways in vitro and to identify novel secreted protein (secretome) changes that potentially contribute to the pathogenesis of IPF. Following induction of telomere dysfunction, a robust senescence phenotype was observed. RNA-seq analysis of the senescent cells revealed the SASP and comparisons to previous murine data highlighted differences in response to telomere dysfunction. We conducted a proteomic analysis of the senescent cells using a novel biotin ligase capable of labeling secreted proteins. Candidate biomarkers selected from our transcriptional and secretome data were then evaluated in IPF and control patient plasma. Four novel proteins were found to be differentially expressed between the patient groups: stanniocalcin-1, contactin-1, tenascin C, and total inhibin. Our data show that human telomere-induced, alveolar epithelial senescence results in a transcriptional SASP that is distinct from that seen in analogous murine cells. Our findings suggest that studies in animal models should be carefully validated given the possibility of species-specific responses to telomere dysfunction. We also describe a pragmatic approach for the study of the consequences of telomere-induced alveolar epithelial cell senescence in humans.

A 21-Year-Old Immune-Competent Man With Recurrent Cough

CASE PRESENTATION

A 21-year-old Chinese man presented with a nonproductive cough for the past 5 months. He denied fevers, chills, night sweats, chest pain, dyspnea, hemoptysis, or weight loss. He was an undergraduate with an unremarkable medical history. He denied any sick contacts and he never smoked. Laboratory tests showed a leukocyte count of 11,200/μL (normal range, 3,500-9,500/μL) with a high neutrophil count and a raised erythrocyte sedimentation rate of 81 mm/h. The purified protein derivative skin test result was positive, and a TB test (T.SPOT.TB; Oxford Immunotec) produced a positive result. The HIV test result was negative. The lung window of the patient's thoracic CT scan showed mottled, patchy opacification in the right lower lobe, and enlarged mediastinal and right hilar lymph nodes (Fig 1A). Bronchoscopy showed mucosal swelling and congestion (Fig 1B). A lymph node (station 11R) biopsy, obtained by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) (Fig 1C), showed nonspecific necrosis. An acid-fast bacillus smear of bronchial secretion produced negative results. He was administered empiric anti-TB therapy (ethambutol, isoniazid, pyrazinamide, and rifapentine). But his cough had not improved by 4 months later. Thus he came to our hospital for a second opinion.

Intestinal epithelium-derived BATF3 promotes colitis-associated colon cancer through facilitating CXCL5-mediated neutrophils recruitment

Inflammation is a critical player in the development and progression of colon cancer. Basic leucine zipper transcription factor ATF-like 3 (BATF3) plays an important role in infection and tumor immunity through regulating the development of conventional type 1 dendritic cells (cDC1s). However, the function of BATF3 in colitis and colitis-associated colon cancer (CAC) remains unclear. Here, BATF3 wild-type and knockout mice were used to construct an AOM/DSS-induced CAC model. In addition, DSS-induced chronic colitis, bone marrow cross-transfusion (BMT), neutrophil knockout, and other animal models were used for in-depth research. We found that BATF3 deficiency in intestinal epithelial cells rather than in cDC1s inhibited CAC, which was depended on inflammatory stimulation. Mechanistically, BATF3 directly promoted transcription of CXCL5 by forming a heterodimer with JunD, and accelerated the recruitment of neutrophils through the CXCL5-CXCR2 axis, ultimately increasing the occurrence and development of CAC. Tissue microarray and TCGA data also indicated that high expression of BATF3 was positively correlated with poor prognosis of colorectal cancer and other inflammation-related tumors. In summary, our results demonstrate that intestinal epithelial-derived BATF3 relies on inflammatory stimulation to promote CAC, and BATF3 is expected to be a novel diagnostic indicator for colitis and CAC.

Texture analysis applied in T1 maps and extracellular volume obtained using cardiac MRI in the diagnosis of hypertrophic cardiomyopathy and hypertensive heart disease compared with normal controls

AIM

To assess the potential of texture analysis (TA) applied in T1 maps and extracellular volume (ECV) obtained using cardiac magnetic resonance (CMR) in the diagnosis of hypertrophic cardiomyopathy (HCM) and hypertensive heart disease (HHD) compared with normal controls (NC). Strain parameters were analysed to compare with final TA models.

MATERIALS AND METHODS

This retrospective study included 66 HCM patients, 39 HHD patients, and 41 NC. Step-wise dimension reduction and feature selection were performed by reproducibility, machine learning, collinearity, and multivariable regression analysis to select the texture features that enable diagnosis of and differentiation between HCM and HHD. Strain parameters were calculated by short-axis and three long-axis cine sequences.

RESULTS

Independent features in T1 maps and ECV analysis allowed for the differentiation between patients (HCM and HHD) and NC. Of the best-calculated model, the areas under the receiver operating curve (AUCs) were as follows: 0.969 for T1 map and 0.964 for ECV. To distinguish HCM from HHD, two independent features were screened out for both T1 and ECV maps. The AUCs were as follows: 0.793 for T1 map and 0.894 for ECV. Radial, circumferential, and longitudinal strain parameters could differentiate patients from NC, but only longitudinal strain parameters was significantly different between HCM and HHD.

CONCLUSIONS

Texture analysis of T1 maps and ECV shows high accuracy in differentiating hypertrophic myocardium from NC, and HCM from HHD. Strain parameters are able to demonstrate the difference between patients and NC, but were less impressive in differentiating HCM and HHD.

Phenotypic Diversity Caused by Differential Expression of SFTPC-Cre-Transgenic Alleles

Type II alveolar epithelial cells (AEC2s) play an essential role in the function and maintenance of the pulmonary epithelium. Several transgenic mice have been developed to study the function of these cells in vivo by using the human SFTPC promoter to drive expression of Cre recombinase. The precise activity of each of these transgenic alleles has not been studied, and previous reports suggest that their activity can depend on breeding strategies. We bred mice with a conditional allele of the essential telomere capping protein TRF2 with two different SFTPC-Cre-transgenic strains and observed opposite phenotypes (100% lethality vs. 100% viability). We characterized the Cre recombinase activity in these two transgenic lines and found that the contrasting phenotypes were driven by difference in embryonic expression of the two transgenes, likely due to position effects or differences in the transgenic constructs. We also tested if SFTPC-Cre activity was dependent on maternal or paternal inheritance. When paternally inherited, both SFTPC-Cre alleles produced offspring with constitutive reporter activity independent of the inheritance of the Cre allele, suggesting that Cre recombinase was expressed in the male germline before meiosis. Immunohistochemical analysis of the testis showed reporter activity during spermatogenesis. Analysis of single-cell RNA sequencing data from murine and human testis demonstrated SFTPC expression uniquely during human spermatogenesis, suggesting that use of the human promoter in these constructs is responsible for male germline activity. Our data highlight the importance of careful analysis of transgenic allele activity and identify an SFTPC-Cre allele that is useful for panepithelial targeting in the mouse.

von Willebrand factor promotes platelet-induced metastasis of osteosarcoma through activation of the VWF-GPIb axis

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Immunohistochemistry results directly show VWF is increased during tumor progression.

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VWF is expressed as low molecular weight multimer in OS cell line SAOS2.

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VWF promotes platelet-induced metastasis of OS through VWF-GPIb pathway.

von Willebrand factor (VWF) is exclusively expressed in endothelial cells (ECs) and megakaryocytes, which plays a crucial role in the initiation of arterial thrombosis. Recent studies have shown that VWF is also expressed in osteosarcoma (OS) cells and participates in adhesion of cancer cells to platelets, thus promoting metastasis of OS cells. However, it is unclear how OS cell-derived VWF-platelet interaction contributes to the metastasis of OS. We hypothesized that the interaction is mediated by the binding between VWF A1 and GPIbα of platelets, a molecular mechanism similar to that of thrombosis. The increased expression of VWF in SAOS2 cells may contribute to the enhancement of platelet adhesion through the VWF-GPIb pathway, which could promote the migration and invasion capacities of SAOS2 cells in vitro. Antibodies that block the pathway could significantly inhibit the platelet-induced metastasis of OS cells. Our results suggest a theoretical basis for the development of new anti-OS metastasis drugs, and further enrich the mechanism of OS metastasis.

Influence of Silver Diamine Fluoride Treatment on the Microtensile Bond Strength of Glass Ionomer Cement to Sound and Carious Dentin

CLINICAL RELEVANCE

This study provides valuable information about the influence of silver diamine fluoride (SDF) treatment on the microtensile bond strength of glass ionomer cement (GIC) to dentin.

SUMMARY

Objectives: To investigate the influence of silver diamine fluoride (SDF) treatment on the microtensile bond strength (mTBS) of glass ionomer cement (GIC) to sound and artificial carious dentin.Methods: Thirty dentin blocks prepared from 30 noncarious human molars were randomly allocated into either the sound (Gp1) or artificial carious dentin (Gp2) groups. A microbiological method was adopted to create artificial dentin caries lesions in Gp2 specimens. Each dentin block was sectioned into two halves perpendicularly, and each pair of block halves was randomly assigned to two subgroups to receive topical application of SDF (Gp1-SDF, Gp2-SDF) or water as control (Gp1-water, Gp2-water). An encapsulated GIC was bonded to the exposed dentin surfaces 14 days after the SDF/water application. After immersion for 7 days in artificial saliva, the GIC-dentin specimens were sectioned into beams for mTBS testing. Failure mode was examined after the mTBS test.Results: There was no significant difference in the mean mTBS values between the SDF and control subgroups (Gp1-SDF vs Gp1-water, 10.57±1.6 MPa vs 10.20±1.8 MPa; Gp2-SDF vs Gp2-water, 6.14±2.2 MPa vs 5.97±2.3 MPa; paired t-test, p>0.05). However, the mean mTBS value of the sound dentin group was significantly higher than that of the carious dentin group, irrespective of whether SDF was applied prior to GIC bonding (independent t-test, p<0.001). Proportionally more cohesive failures occurred in the sound dentin groups (Gp1-SDF, 48.4%; Gp1-water, 42.9%) compared with the carious dentin groups (Gp2-SDF, 15.6%; Gp2-water, 9.8%; p<0.05).Conclusions: SDF treatment had no significant influence on the mTBS of GIC to dentin. Compared with sound dentin, dentin with caries had lower mTBS to GIC.

Exosomes: Carriers of Pro-Fibrotic Signals and Therapeutic Targets in Fibrosis

Exosomes are nano-sized extracellular vesicles that are released by a variety of cells. Exosomes contain cargo from cells they derived, including lipids, proteins and nucleic acids. The bilayer lipid membrane structure of exosomes protects these contents from degradation, allowing them for intercellular communication. The role of exosomes in fibrotic diseases is increasingly being valued. Exosomes, as carriers of profibrotic signals, are involved in the development of fibrotic diseases, and also regulate fibrosis by transmitting signals that inhibit fibrosis or inflammation. Exosomes mobilize and activate a range of effector cells by targeted delivery of bioactive information. Exosomes can also reflect the condition of cells, tissues and organisms, and thus become potential biomarkers of fibrotic diseases. Exosomes from bone marrow stem cells support biological signaling that regulates and inhibits fibrosis and thus initially used in the treatment of fibrotic diseases. This article briefly summarizes the role of exosomes in the pathogenesis and treatment of fibrotic diseases and raises some issues that remain to be resolved.

Coronavirus disease 2019: a clinical review

In December 2019, an outbreak of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was reported in Wuhan, China, and it subsequently spread in many countries around the world. Many efforts have been applied to control and prevent the spread of COVID-19, and many scientific studies have been conducted in a short period of time. Here we present an overview of the viral structure, pathogenesis, diagnosis, and clinical features of COVID-19 based on the current state of knowledge, and we compare its clinical characteristics with SARS and Middle East Respiratory Syndrome (MERS). Current researches on potentially effective treatment alternatives are discussed. We hope this review can help medical workers and researchers around the world contain the current COVID-19 pandemic.

Search for Electron Antineutrino Appearance in a Long-Baseline Muon Antineutrino Beam

Electron antineutrino appearance is measured by the T2K experiment in an accelerator-produced antineutrino beam, using additional neutrino beam operation to constrain parameters of the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) mixing matrix. T2K observes 15 candidate electron antineutrino events with a background expectation of 9.3 events. Including information from the kinematic distribution of observed events, the hypothesis of no electron antineutrino appearance is disfavored with a significance of 2.40σ and no discrepancy between data and PMNS predictions is found. A complementary analysis that introduces an additional free parameter which allows non-PMNS values of electron neutrino and antineutrino appearance also finds no discrepancy between data and PMNS predictions.

COVID-19 in a patient with long-term use of glucocorticoids: A study of a familial cluster

Clusters of patients with novel coronavirus disease 2019 (COVID-19) have been successively reported globally. Studies show clear person-to-person transmission. The average incubation period is 2–14 days, and mostly 3–7 days. However, in some patients, this period may be longer. Here, we report a familial cluster of COVID-19 where a 47-year-old woman with long-term use of glucocorticoids did not develop any symptoms within the 14-day quarantine period but was confirmed with COVID-19 by tested positive of antibody on day 40 after she left Wuhan. Almost at the same time, her father and sister were diagnosed with COVID-19. The results suggest that the long-term use of glucocorticoids might cause atypical infections, a long incubation period, and extra transmission of COVID-19.

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We report a familial cluster of COVID-19 outside of Wuhan, including 3 confirmed cases out of 5 family members.

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The index patient, who had been taking glucocorticoids for 16 years, initially developed atypical symptoms of COVID-19.

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The incubation period and shedding time were extremely long in this familial case.

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Our results suggest a longer quarantine time for patients with long-term glucocorticoid use.

Effects of stacking periodicity on the electronic and optical properties of GaAs/AlAs superlattice: a first-principles study

The effects of stacking periodicity on the electronic and optical properties of GaAs/AlAs superlattice have been explored by density functional theory calculations. Among the (GaAs)m/(AlAs)m, (GaAs)1/(AlAs)m and (GaAs)m/(AlAs)1 (m = 1 to 5) superlattices, the band gaps of (GaAs)m/(AlAs)1 superlattices decrease significantly as the layer of GaAs increases, and the cut-off wavelengths are found to locate in the near infrared region. For (GaAs)m/(AlAs)1 SLs, the conduction bands shift toward Fermi level, resulting in the smaller band gap, while conduction bands of (GaAs)1/(AlAs)n SLs slightly shift to higher energy, which lead to comparable band gaps. The layer number of GaAs shows negligible effects on the reflectivity spectra of superlattice structures, while the absorption coefficient shows a red-shift with the increasing layer of GaAs, which is beneficial for the application of GaAs/AlAs superlattice in the field of near infrared detector. These results demonstrate that controlling the number of GaAs layers is a good method to engineer the optoelectronic properties of GaAs/AlAs superlattice.

Clinical features and endemic trend of histoplasmosis in China: A retrospective analysis and literature review

INTRODUCTION

Histoplasmosis is a rare mycosis with nonspecific clinical manifestation and a high misdiagnosis rate, which is an epidemic disease that occurred in several endemic areas. Cases of histoplasmosis were sporadic in China.

OBJECTIVE

We detected the clinical characteristics and endemic trend of histoplasmosis to understand it more profoundly.

METHOD

The clinical data of 34 cases of histoplasmosis hospitalized in Xiangya Hospital of Central South University from 2003 to 2016 were analyzed retrospectively. The relevant literature were reviewed roundly which were about histoplasmosis from 2001 to 2019 reported in the Chinese mainland.

RESULTS

Thirty-four patients were included in the study, male predominance. About 44.1% were combined with underlying disease and HIV infection was observed in eight patients. Common clinical manifestations were fever (94.1%), followed by lymphadenopathy (70.6%) and anemia (67.6%). Organ involvement included lungs (52.9%), oral cavity (5.9%) and intestine (5.9%). Patients were diagnosed by bone marrow smears (44.1%), lymph node biopsy (41.1%), lung tissue biopsy (8.8%) and intestinal tissue biopsy (5.9%). About 70.6% received amphotericin B, while 38.2% received itraconazole therapy and 79.4% were improved. About 611 cases of histoplasmosis in the Chinese mainland were obtained in the study from the related literature, with 217 (37.0%) cases occurred in Yunnan province, 69 (11.9%) cases in Hunan province and 67 (11.6%) cases in Hubei province. All of them were high incidence area of histoplasmosis.

CONCLUSION

Histoplasmosis is a rare mycosis with high diagnosis rate and has a prominent geographical distribution in China, which should be considered highly in clinical work.

Clinical features and prognosis analysis of 57 patients with primary tracheal tumors

Background

Primary tracheal tumor (PTT) is a rare disease with poor prognosis. Its clinical features are variable. Treatment strategies for patients with PTTs are not standardized. The purpose of this study was to explore the clinical features, management and prognosis of PTT.

Methods

From 2009 to 2019, 57 patients were diagnosed with PTTs at Xiangya Hospital, China. A retrospective review of their medical records was performed.

Results

Among the 57 patients, 8 (14.0%) had benign tumors and 49 (86.0%) had malignant. Squamous cell carcinoma (SCC) (n=20, 40.8%) and adenoid cystic carcinoma (ACC) (n=10, 20.4%) were the most common histologic types. Seven (87.5%) of the benign PTT patients underwent bronchoscopic intervention and had no further complications. The 5-year survival rate for malignant PTTs was 13.8%. Patients who had ACC tended to have better survival rates than those with SCC, although the difference was not statistically significant (P=0.104). Compared with tumors located in upper third of the trachea, tumors located in the lower portion showed worse survival (P=0.0003). Patients who underwent complete surgical resection had significantly better survival compared to non-surgical therapies (P=0.016). The combination of chemoradiotherapy and bronchoscopic intervention was better than chemoradiotherapy alone (P=0.028).

Conclusions

Histologic type, tumor location and treatment approaches likely influence clinical outcomes. Within the cohort described here, complete surgical resection was the optimal therapy for PTTs. For unresectable malignant PTTS, chemoradiotherapy with bronchoscopic intervention was a superior modality. Given the poor 5-year survival of PTT, larger-scale, multi-center studies are warranted to validate our findings and identify optimal therapeutic interventions.

Evaluating Plasma Skimming with Whole Blood in Small Gap Region Imitating Clearance of Blood Pumps

Plasma skimming is the phenomenon whereby the discharge hematocrit is lower than feed hematocrit naturally occurring in the microvessels with Poiseuille flow. It has been studied in Poiseuille flow extensively. Besides, plasma skimming has also been observed and investigated in blood pumps due to its potential to prevent hemolysis by skimming blood cells out of the small gap. However, whether plasma skimming occurs in blood pumps with whole blood has not been verified. Additionally, the independent influence of rotational speed and gap size has not been clarified. Therefore, in order to lay the foundation of applying plasma skimming to the development of blood pumps and also investigate the influence of rotational speed and gap size on plasma skimming respectively, we designed a simplified geometric device which not only imitates the flow inside clearances of blood pumps, but also provides different rotational speed and gap size conditions. We first conducted the verification tests of plasma skimming using whole blood with an initial hematocrit of 44% and the gap size was varied from 10 μm to 240 μm with 10 μm interval. The plasma skimming was verified occurring when the gap was less than 70 μm at a rotational speed of 800 rpm. Since plasma skimming was confirmed, we employed 30% hematocrit blood and performed the following tests to evaluate the influence of rotational speed of 600 rpm, 700 rpm, and 800 rpm respectively. As a result, the hematocrit of sampled blood declined as the rotational speed increased from 600 rpm to 800 rpm. And there was the lowest hematocrit of 16% when the gap was adjusted to 50 μm gap size at 800 rpm. This study further promotes the possibility of applying plasma skimming to the blood pumps with higher hemocapability.

Thermal Modulation of MOF and Its Application in Lithium-Sulfur Batteries

The applications of metal-organic frameworks (MOFs) as sulfur hosts focus on pristine MOFs and their carbonization products for establishing high-performance lithium-sulfur batteries (LSBs). However, the mechanism that modulates the specific nanostructures and the compositions at different treatment temperatures still needs further exploration. In this work, we modulate the pyrolysis products of UiO-66-NH₂@rGO (U@rGO) at a predetermined specific temperature by thermogravimetric (TG) analysis and systematically investigate their microstructure and chemical characteristic evolution. The composite processed at 300 °C (U@rGO-P300) results in the rearrangement of an octahedral nanophase into an amorphous material while retaining a large number of functional groups of -NH₂ and COO-, which lead to an additional nanostructure interface and a high Brunauer-Emmett-Teller (BET) surface area of 298.4 m² g^-1. Moreover, the newly created abundant suboxidative Zr³⁺ atom sites serve as the polysulfide anchor and transfer mediator active sites. The assembled LSBs could deliver a capacity of 906.1 and retain 801.7 mA h g^-1 after 300 cycles at 1C with a low fading rate of around 0.05% per cycle and an improved rate performance of 619.1 mA h g^-1 at 4C. The Li⁺ diffusion coefficients are significantly increased by 10-60 times. This work provides a simple route to activate the metal sites in the MOF category with a suboxidative state, leading to intriguing and unanticipated properties.

Incorporating non-stomatal limitation improves the performance of leaf and canopy models at high vapour pressure deficit

Vapour pressure deficit (D) is projected to increase in the future as temperature rises. In response to increased D, stomatal conductance (gs) and photosynthesis (A) are reduced, which may result in significant reductions in terrestrial carbon, water and energy fluxes. It is thus important for gas exchange models to capture the observed responses of gs and A with increasing D. We tested a series of coupled A-gs models against leaf gas exchange measurements from the Cumberland Plain Woodland (Australia), where D regularly exceeds 2 kPa and can reach 8 kPa in summer. Two commonly used A-gs models were not able to capture the observed decrease in A and gs with increasing D at the leaf scale. To explain this decrease in A and gs, two alternative hypotheses were tested: hydraulic limitation (i.e., plants reduce gs and/or A due to insufficient water supply) and non-stomatal limitation (i.e., downregulation of photosynthetic capacity). We found that the model that incorporated a non-stomatal limitation captured the observations with high fidelity and required the fewest number of parameters. Whilst the model incorporating hydraulic limitation captured the observed A and gs, it did so via a physical mechanism that is incorrect. We then incorporated a non-stomatal limitation into the stand model, MAESPA, to examine its impact on canopy transpiration and gross primary production. Accounting for a non-stomatal limitation reduced the predicted transpiration by ~19%, improving the correspondence with sap flow measurements, and gross primary production by ~14%. Given the projected global increases in D associated with future warming, these findings suggest that models may need to incorporate non-stomatal limitation to accurately simulate A and gs in the future with high D. Further data on non-stomatal limitation at high D should be a priority, in order to determine the generality of our results and develop a widely applicable model.