Development and Validation of CT-Based Clinical-Radiomics Nomogram for Early Stage Extranodal Nasal-Type NK/T Cell Lymphoma: A Multicenter Study

PURPOSE/OBJECTIVE(S)

Most patients with extranodal nasal-type NK/T cell lymphoma (ENKTCL) had a localized disease with extensive primary tumor invasion at diagnosis (70-90%). Several clinical risk indexes, such as nomogram-revised risk index (NRI), international prognostic index (IPI), Korean Prognostic Index (KPI) and prognostic index of natural killer lymphoma (PINK), were used for ENKTCL patient stratification and providing information in clinical decision-making. However, they had low predictive power for early-stage patients with ENKTCL. This is the first study to construct a model with more predictive power through CT-based radiomics signature combined with traditional clinical risk indexes for overall survival (OS) of patients with early-stage ENKTCL.

MATERIALS/METHODS

A total of 196 early stage ENKTCL patients were randomly assigned into the training (n = 147) and interval validation set (n = 49) in a 3:1 ratio. And 83 and 19 early stage ENKTCL patients from other two centers were used for external validation set (n = 62). All patients received radiotherapy after 2-3 cycles of chemotherapy. 1316 CT radiomic features before radiotherapy were extracted and selected to construct the radiomics signature (RS). A CT-based nomogram was established by integrating clinical indexes and radiomics signature in training set and was tested in two validation sets.

RESULTS

With a median follow-up period of 59.9 months, 48 patients (24.1%) died. Compared with other prognostic index, NRI had better power to predict 5-year OS in the training cohort. The radiomics signature constructed by 11 selected radiomic features showed better prognostic performance than NRI for predicting 5-year OS in training set (C-index: 0.75 vs. 0.66), internal validation set (C-index: 0.71 vs. 0.62) and external validation set (C-index: 0.68 vs. 0.60). Patients were stratified into high- and low-risk groups by median radiomic signature. Patients in high-risk group had worse 5-year OS than patients in low-risk group (training set: 92% vs. 65%, P<0.001; internal validation set: 88% vs. 59%, P<0.05; external validation set 90% vs. 60%, P<0.05). The nomogram established by integrating radiomics signature with NRI showed optimal prognostic performance with C-index of 0.77 in training, 0.73 in internal and 0.71 in external validation set. Calibration curves showed good agreement.

CONCLUSION

The clinical-radiomics nomogram integrating CT-based radiomics signature combined with traditional clinical risk index provided an excellent prognostic tool for OS, which could be helpful for personalized risk stratification and treatment in early stage ENKTCL patients.

Metabolomics reveals serum metabolic signatures in H-type hypertension based on mass spectrometry multi-platform

BACKGROUND

H-type hypertension (HHT) is a disease combined with hyperhomocysteinaemia and hypertension (HT). This study aims to find specific metabolic changes and reveal the pathophysiological mechanism of HHT, which provide the theoretical basis for the early prevention and treatment of HHT.

METHODS

Serum samples from three groups including 53 HHT patients, 36 HT patients and 46 healthy controls (HC) were collected. The targeted and untargeted metabolomics analyses were performed to determine the metabolic changes. Based on multivariate statistical analysis, the serum potential metabolites were screened and different metabolic pathways were explored.

RESULTS

Our results demonstrated that there were 28 important potential metabolites for distinguishing HT from HHT patients. Metabolic pathway analysis showed that the different metabolic pathways between HHT and HC group were arginine biosynthesis, arginine and proline metabolism, and tyrosine metabolism. The changed metabolic pathway of HT and HC group included linoleic acid metabolism. The specific metabolic pathways of HT-HHT comparison group had phenylalanine metabolism; phenylalanine, tyrosine and tryptophan biosynthesis; glycine, serine and threonine metabolism.

CONCLUSIONS

Metabolomics analysis by mass spectrometry multi-platform revealed the differences of metabolic profiles between HHT and HT subjects. This work laid the groundwork for understanding the aetiology of HHT, and these findings may provide the useful information for explaining the HHT metabolic alterations and try to prevent HHT.

Endothelial SARS-CoV-2 infection is not the underlying cause of COVID-19-associated vascular pathology in mice

Endothelial damage and vascular pathology have been recognized as major features of COVID-19 since the beginning of the pandemic. Two main theories regarding how severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) damages endothelial cells and causes vascular pathology have been proposed: direct viral infection of endothelial cells or indirect damage mediated by circulating inflammatory molecules and immune mechanisms. However, these proposed mechanisms remain largely untested in vivo. In the present study, we utilized a set of new mouse genetic tools developed in our lab to test both the necessity and sufficiency of endothelial human angiotensin-converting enzyme 2 (hACE2) in COVID-19 pathogenesis. Our results demonstrate that endothelial ACE2 and direct infection of vascular endothelial cells do not contribute significantly to the diverse vascular pathology associated with COVID-19.

[The first imported case of visceral leishmaniasis in Shenzhen City]

A patient with fever, chills, and pancytopenia as major clinical manifestations was presented. To investigate the cause, the patient's peripheral blood was collected for pathogen screening using metagenomic next - generation sequencing (mNGS). The DNA sequence of Leishmania donovani was detected, and Leishmania amastigotes were found in bone marrow smears using microscopy. The case was therefore definitively diagnosed as visceral leishmaniasis, and was cured and discharged from hospital following treatment with liposomal amphotericin B for 14 days. This is the first imported case of visceral leishmaniasis since the founding of Shenzhen City in 1979.

Research on charge induction law and application of coal samples with different fissures

Indoor testing are performed to explore the charge induction law during the uniaxial compression fracture process of coal samples, and the charge time and frequency domain signals of coal samples with different primary fissures are analyzed in the paper. On-site monitoring of charge in different fissures distribution areas of underground coal tunnels, and the charge signals of different drillingdepths in coal seams are analyzed. The results show that the uniaxial compressive strength and elastic modulus of multi-fissured coal samples are less than those of less fissured coal samples, and the Poisson's ratio is greater than those of less fissured coal samples. The charge induction signal intensity during the fracture process of multi-fissured coal samples is relatively low, but it is concentrated at the low frequency of 0-50 Hz in the compacting elasticity stage. The charge signal intensity during the fracture process of coal samples with less fissure is relatively high, and the charge frequency during the reinforcement damage stage is concentrated at a low frequency of 0-50 Hz. Therefore, the sudden appearance of low-frequency charge signals is more suitable as effective precursor information for the instability and failure of less fissured coal bodies. The average charge intensity is small in the multi-fissured area with a drilling depth of 1-4 m in the coal seam, and the average charge intensity of the coal body with less fissures is larger in the 5-12 m region. The on-site charge monitoring results have good consistency with the indoor test results. This study has guiding significance in setting up a charge monitoring warning index of instability failure in different coal body fissures regions.

Effects of Different Primers on the Bond Strength to Properly and Excessively Etched Ceramic-coated Zirconia

PURPOSE

To determine the effects of various primers on the immediate and long-term bond strength of ceramic-coated ultratranslucent zirconia that is properly or excessively etched.

METHODS AND MATERIALS

Ceramic-coated zirconia plates were etched with 9.5% hydrofluoric acid (HF) for 2 or 5 minutes, after which the surface morphology and elemental composition were examined. The etched specimens were treated with different primers including methacryloyloxydecyl dihydrogen phosphate (MDP)-only containing primer, silane-only containing primer, MDP and silane-containing ceramic primer as well as MDP and silane-containing adhesive system. For surface contact angle and shear bond strength (SBS) data, the difference between groups was evaluated by one-way analysis of variance (ANOVA) and three-way ANOVA factorial analysis, respectively. The statistical significance level of 0.05 was set and the Tukey test and the Dunnett-T3 test were used for post-hoc multiple comparisons.

RESULTS

Excessive etching (9.5% HF for 5 minutes) led to overconsumption of the glass layer and exposure of zirconia substrate compared to proper etching (9.5% HF for 2 minutes). Among different primers, the surface contact angle of the silane-only containing primer group was the lowest. The silane-only containing primer and MDP and silane-containing ceramic primer produced higher shear bond strength of properly and excessively etched ceramic-coated zirconia, respectively, both before and after thermal aging.

CONCLUSIONS

The silane-only containing primer and MDP and silane-containing primer can obtain better immediate and long-term shear bond strength for properly and excessively etched ceramic-coated zirconia, respectively.

Endothelial SARS-CoV-2 infection is not the underlying cause of COVID19-associated vascular pathology in mice

Endothelial damage and vascular pathology have been recognized as major features of COVID-19 since the beginning of the pandemic. Two main theories regarding how Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) damages endothelial cells and causes vascular pathology have been proposed: direct viral infection of endothelial cells or indirect damage mediated by circulating inflammatory molecules and immune mechanisms. However, these proposed mechanisms remain largely untested in vivo. Here, we utilized a set of new mouse genetic tools 1 developed in our lab to test both the necessity and sufficiency of endothelial human angiotensin-converting enzyme 2 (hACE2) in COVID19 pathogenesis. Our results demonstrate that endothelial ACE2 and direct infection of vascular endothelial cells does not contribute significantly to the diverse vascular pathology associated with COVID-19.

[Effect of Porphyromonas gingivalis infection on IFNGR1 palmitoylation in esophageal cancer cells]

OBJECTIVE

To investigate the effect of Porphyromonas gingivalis (Pg) infection on IFNGR1 palmitoylation and biological behaviors of esophageal squamous cell carcinoma (ESCC) cells and the clinical implications.

METHODS

The expression levels of IFNGR1 protein in ESCC cell lines KYSE30 and KYSE70 were detected using Western blotting at 24 and 48 h after Pg infection, and 2-BP was used to detect IFNGR1 palmitoylation in the cells. KYSE70 cells with wild-type IFNGR1 (IFNGR1-WT cells) and with IFNGR1-C122A palmitoylation site mutation induced by site-specific mutagenesis (IFNGR1-C122A cells) were both infected with Pg, and the changes in palmitoylation of IFNGR1-C122A were analyzed using immunofluorescence and Click-iT assays. The changes in proliferation, migration and invasion ability of the infected cells were evaluated using plate cloning assay, scratch assay and Transwell assay, and IFNGR1 co-localization with lysosomal marker LAMP2 was dected using immunofluorescence assay. Immunohistochemistry was used to detect Pg infection and IFNGR1 protein expression in 50 ESCC tissues, and their correlation with the clinicopathological characteristics and survival outcomes of the patients was analyzed.

RESULTS

Pg infection down-regulated the protein expression of IFNGR1 in ESCC and promoted IFNGR1 palmitoylation at site 122. In IFNGR1-WT cells, Pg infection significantly enhanced cell proliferation, migration and invasion (P < 0.05). Similarly, Pg also significantly promoted proliferation, migration and invasion of IFNGR1-C122A cells, but to a lesser extent as compared with the wild-type cells (P < 0.05). Immunofluorescence assay showed that Pg and ZDHHC3 promoted IFNGR1 degradation within the lysosome. Immunohistochemical studies of the ESCC tissue samples showed a negative correlation between IFNGR1 and Pg expression, and a reduced IFNGR1 expression was correlated with a poorer survival outcome of the patient.

CONCLUSION

Pg infection enhances IFNGR1 palmitoylation to promote progression of ESCC, and elimination of Pg and inhibiting IFNGR1 palmitoylation may effectively control ESCC progression.

[Oligonucleotide drugs and their progress in stomatology]

Oligonucleotide drugs have the characteristics of targeting, modifiability and high biosafety. Recent studies have shown that oligonucleotide can be used to make biosensors, vaccine adjuvants, and has the functions of inhibiting alveolar bone resorption, promoting jaw and alveolar bone regeneration, anti-tumor, destroying plaque biofilm, and precise control of drug release. Therefore, it has a broad application prospect in the field of stomatology. This article reviews the classification, action mechanism and research status of oligonucleotide in stomatology. The aim is to provide ideas for further research and application of oligonucleotide.

[Association between coagulation function indicators and placental abruption among preeclampsia-eclampsia pregnant women]

Objective: To explore the association between coagulation function indicators and placental abruption (PA) in different trimesters of pregnancy among preeclampsia-eclampsia pregnant women. Methods: From February 2018 to December 2020, pregnant women who participated in the China birth cohort study and were diagnosed with preeclampsia, eclampsia and chronic hypertension with superimposed preeclampsia in Beijing Obstetrics and Gynecology Hospital were enrolled in this study. The baseline and follow-up information were collected by questionnaire survey, and the coagulation function indicators in the first and third trimesters were obtained through medical records. The Cox proportional hazards model was used to analyze the association between the coagulation function indicators and PA. A restrictive cubic spline curve was used to draw the dose-response curve between the relevant coagulation function indicators and PA. Results: A total of 1 340 participants were included in this study. The age was (32.50±4.24) and the incidence of PA was 4.4% (59/1 340). After adjusting for relevant factors, Cox proportional hazards model showed that compared with the high-level classification of fibrinogen (FIB), participants within the middle-(HR=3.28, 95%CI: 1.27-8.48) and low-level (HR=3.84, 95%CI: 1.40-10.53) classification during the first trimester and within the low-level classification (HR=4.18, 95%CI: 1.68-10.39) during the third trimester were more likely to experience PA. Compared with the middle-level classification of pro-thrombin time (PT), the risk of PA in the participants within the low-level classification (HR=2.67, 95%CI: 1.48-4.82) was significantly higher in the third trimester. The restrictive cubic spline analysis showed a linear negative association between FIB and PA in the first and third trimesters, while PT and PA showed an approximately L-shaped association. Conclusion: Among pregnant women diagnosed with preeclampsia-eclampsia, the middle-and low-level classification of FIB in the first and third trimesters and the low-level classification of PT in the third trimester could increase the risk of PA.

[Progress in researches on cardiovascular health behaviors and factors in perinatal women]

The cardiovascular health index (CVH) is a composite index consisting of 7 CVH metrics (CVHM) to evaluate the cardiovascular health status in the population. CVH has been proven to be closely related to a variety of health outcomes and widely used in the prevention of many diseases and the evaluation of intervention effectiveness. This review summarizes the recent distribution of CVH and CVHM in pregnant women and the relationship between CVH and CVHM with adverse health outcomes, which aims to explore the application of CVH and CVHM in preventing pregnancy-related diseases and improving the long-term health level of perinatal women and their offspring.

[Analysis of incidence and associated factors of preterm birth based on pre-pregnancy body mass index stratification]

Objective: To analyze the incidence of preterm birth based on pre-pregnancy body mass index (BMI) stratification and explore the associated factors of preterm birth among pregnant women at different BMI stratifications. Methods: From February 2018 to December 2020, pregnant women who participated in China Birth Cohort Study (CBCS) and gave birth at Beijing Obstetrics and Gynecology Hospital were enrolled as the study subjects. Electronic Data Capture System and standard structured questionnaires were used to collect data related to pre-pregnancy, pregnancy, and delivery for pregnant women. Pregnant women were divided into the low-weight group, normal-weight group and overweight group based on their pre-pregnancy BMI. A Cox proportional hazards model was used to analyze the associated factors of preterm birth among pregnant women with different BMI before pregnancy. Results: A total of 27 195 singleton pregnant women were included, with a preterm birth rate of 5.08% (1 381/27 195). The preterm birth rates in the low-weight group, normal-weight group and overweight group were 4.29% (138/3 219), 4.63% (852/18 390) and 7.00% (391/5 586) respectively (P<0.001). After adjusting for relevant factors, the Cox proportional hazards model showed that the risk of preterm birth in the overweight group was 1.457 times higher than that in the normal-weight group (95%CI: 1.292-1.643). Preeclampsia-eclampsia (HR=2.701, 95%CI: 1.318-5.537) was the associated factor for preterm birth in the low-weight group. Advanced maternal age (HR=1.232, 95%CI: 1.054-1.441), history of preterm birth (HR=4.647, 95%CI: 3.314-6.515), vaginal bleeding in early pregnancy (HR=1.613, 95%CI: 1.380-1.884), and preeclampsia-eclampsia (HR=3.553, 95%CI: 2.866-4.404) were associated factors for preterm birth in the normal-weight group. Advanced maternal age (HR=1.473, 95%CI: 1.193-1.818), history of preterm birth (HR=3.209, 95%CI: 1.960-5.253), vaginal bleeding in early pregnancy (HR=1.636, 95%CI: 1.301-2.058), preeclampsia-eclampsia (HR=2.873, 95%CI:2.265-3.643), and pre-gestational diabetes mellitus (HR=1.867, 95%CI: 1.283-2.717) were associated factors for preterm birth in the overweight group. Conclusion: Pre-pregnancy overweight is an associated factor for preterm birth, and there are significant differences in the associated factors of preterm birth among pregnant women with different BMI before pregnancy.

[Oligonucleotide drugs and their progress in stomatology]

Oligonucleotide drugs have the characteristics of targeting, modifiability and high biosafety. Recent studies have shown that oligonucleotide can be used to make biosensors, vaccine adjuvants, and has the functions of inhibiting alveolar bone resorption, promoting jaw and alveolar bone regeneration, anti-tumor, destroying plaque biofilm, and precise control of drug release. Therefore, it has a broad application prospect in the field of stomatology. This article reviews the classification, action mechanism and research status of oligonucleotide in stomatology. The aim is to provide ideas for further research and application of oligonucleotide.

TRAmHap: accurate prediction of transcriptional activity from DNA methylation haplotypes in bisulfite-sequencing data

Deoxyribonucleic acid (DNA) methylation (DNAm) is an important epigenetic mechanism that plays a role in chromatin structure and transcriptional regulation. Elucidating the relationship between DNAm and gene expression is of great importance for understanding its role in transcriptional regulation. The conventional approach is to construct machine-learning-based methods to predict gene expression based on mean methylation signals in promoter regions. However, this type of strategy only explains about 25% of gene expression variation, and hence is inadequate in elucidating the relationship between DNAm and transcriptional activity. In addition, using mean methylation as input features neglects the heterogeneity of cell populations that can be reflected by DNAm haplotypes. We here developed TRAmaHap, a novel deep-learning framework that predicts gene expression by utilizing the characteristics of DNAm haplotypes in proximal promoters and distal enhancers. Using benchmark data of human and mouse normal tissues, TRAmHap shows much higher accuracy than existing machine-learning based methods, by explaining 60~80% of gene expression variation across tissue types and disease conditions. Our model demonstrated that gene expression can be accurately predicted by DNAm patterns in promoters and long-range enhancers as far as 25 kb away from transcription start site, especially in the presence of intra-gene chromatin interactions.

[Comparison of diagnostic performance of Clear Cell Likelihood Score v1.0 and v2.0 for clear renal cell carcinoma]

OBJECTIVE

To compare the performance of Clear Cell Likelihood Score (ccLS) v1.0 and v2.0 in diagnosing clear cell renal cell carcinoma (ccRCC) from small renal masses (SRM).

METHODS

We retrospectively analyzed the clinical data and MR images of patients with pathologically confirmed solid SRM from the First Medical Center of the Chinese PLA General Hospital between January 1, 2018, and December 31, 2021, and from Beijing Friendship Hospital of Capital Medical University and Peking University First Hospital between January 1, 2019 and May 17, 2021. Six abdominal radiologists were trained for use of the ccLS algorithm and scored independently using ccLS v1.0 and ccLS v2.0. Random- effects logistic regression modeling was used to generate plot receiver operating characteristic curves (ROC) to evaluate the diagnostic performance of ccLS v1.0 and ccLS v2.0 for ccRCC, and the area under curve (AUC) of these two scoring systems were compared using the DeLong's test. Weighted Kappa test was used to evaluate the interobserver agreement of the ccLS score, and differences in the weighted Kappa coefficients was compared using the Gwet consistency coefficient.

RESULTS

In total, 691 patients (491 males, 200 females; mean age, 54 ± 12 years) with 700 renal masses were included in this study. The pooled accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of ccLS v1.0 for diagnosing ccRCC were 77.1%, 76.8%, 77.7%, 90.2%, and 55.7%, as compared with 80.9%, 79.3%, 85.1%, 93.4%, 60.6% with ccLS v2.0, respectively. The AUC of ccLS v2.0 was significantly higher than that of ccLS v1.0 for diagnosis of ccRCC (0.897 vs 0.859; P < 0.01). The interobserver agreement did not differ significantly between ccLS v1.0 and ccLS v2.0 (0.56 vs 0.60; P > 0.05).

CONCLUSION

ccLS v2.0 has better performance for diagnosing ccRCC than ccLS v1.0 and can be considered for use to assist radiologists with their routine diagnostic tasks.

[Comparison of the predictive value of Padua and the IMPEDE assessment scores for venous thromboembolism in patients with newly diagnosed multiple myeloma: A single institution experience]

Objective: To compare the predictive efficacy of the two thrombosis risk assessment scores (Padua and IMPEDE scores) in venous thromboembolism (VTE) within 6 months in patients with newly diagnosed multiple myeloma (NDMM) in China. Methods: This study reviewed the clinical data of 421 patients with NDMM hospitalized in Beijing Jishuitan Hospital from April 2014 to February 2022. The sensitivity, specificity, accuracy, and Youden index of the two scores were calculated to quantify the thrombus risk assessment of VTE by the Padua and IMPEDE scores. The receiver operating characteristics curves of the two evaluation scores were drawn. Results: The incidence of VTE was 14.73%. The sensitivity, specificity, accuracy, and Youden index of the Padua score were 100%, 0%, 14.7%, and 0% and that of the IMPEDE score was 79%, 44%, 49.2%, and 23%, respectively. The areas under the curve of Padua and IMPEDE risk assessment scores were 0.591 and 0.722, respectively. Conclusion: IMPEDE score is suitable for predicting VTE within 6 months in patients with NDMM.

Mineral protection controls soil organic carbon stability in permafrost wetlands

Mineral protection can slow the effect of warming on the mineralization of organic carbon (OC) in permafrost wetlands, which has an important impact on the dynamics of soil OC. However, the response mechanisms of wetland mineral soil to warming in permafrost areas are unclear. In this study, the soil of the southern edge of the Eurasian permafrost area was selected, and bulk and heavy fraction (HF) soil was subjected to indoor warming incubation experiments using physical fractionation. The results showed that the HF accounted for 51.25 % of the total OC mineralization in the bulk soil, and the δ¹³C value of the CO₂ that was emitted in the HF soil was higher than that of the bulk soil. This indicates the potential availability of mineral soil and that the mineralized OC in the HF was the more stable component. Additionally, the mineralization of the mineral subsoil after warming by 10 °C was only about half of the increase in the organic topsoil, and the temperature sensitivity was significantly negatively correlated with the Fe/Al oxides to OC ratio. The results indicate that under conditions of permafrost degradation, the physical protection of mineral soil at high latitudes is essential for the stability of OC, which may slow the trend of permafrost wetlands becoming carbon sources.

Genome editing with natural and engineered CjCas9 orthologs

CjCas9 is one of the smallest CRISPR-associated (Cas9) nucleases for mammalian genome editing. However, it requires a long N4RYAC (R = A or G; Y = C or T) protospacer-adjacent motif (PAM), limiting its DNA targeting scope. In this study, we investigated the PAMs of three CjCas9 orthologs, including Hsp1Cas9, Hsp2Cas9, and CcuCas9, by performing a GFP-activation assay. Interestingly, Hsp1Cas9 and CcuCas9 recognized unique N4RAA and N4CNA PAMs, respectively. We further generated an Hsp1Cas9-Hsp2Cas9 chimeric Cas9 (Hsp1-Hsp2Cas9), which recognized a simple N4CY PAM. Genome-wide off-target analysis revealed that Hsp1-Hsp2Cas9 has very few off-targets compared to SpCas9. By analyzing the crystal structure of CjCas9, we identified eight mutations that can improve the specificity and generate a high-fidelity Hsp1-Hsp2Cas9-Y. Hsp1-Hsp2Cas9-Y enables the knockout of B4GALNT2 and CMAH in porcine fetal fibroblasts (PFFs). Moreover, we developed a high-fidelity Hsp1-Hsp2Cas9-KY which displayed undetectable off-targets revealed by GUIDE-seq at four tested loci. These natural and engineered Cas9 nucleases enabled efficient genome editing in multiple mammalian cells, expanding the DNA targeting scope.

Cell-autonomous requirement for ACE2 across organs in lethal mouse SARS-CoV-2 infection

Angiotensin-converting enzyme 2 (ACE2) is the cell-surface receptor for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). While its central role in Coronavirus Disease 2019 (COVID-19) pathogenesis is indisputable, there remains significant debate regarding the role of this transmembrane carboxypeptidase in the disease course. These include the role of soluble versus membrane-bound ACE2, as well as ACE2-independent mechanisms that may contribute to viral spread. Testing these roles requires in vivo models. Here, we report humanized ACE2-floxed mice in which hACE2 is expressed from the mouse Ace2 locus in a manner that confers lethal disease and permits cell-specific, Cre-mediated loss of function, and LSL-hACE2 mice in which hACE2 is expressed from the Rosa26 locus enabling cell-specific, Cre-mediated gain of function. Following exposure to SARS-CoV-2, hACE2-floxed mice experienced lethal cachexia, pulmonary infiltrates, intravascular thrombosis and hypoxemia-hallmarks of severe COVID-19. Cre-mediated loss and gain of hACE2 demonstrate that neuronal infection confers lethal cachexia, hypoxemia, and respiratory failure in the absence of lung epithelial infection. In this series of genetic experiments, we demonstrate that ACE2 is absolutely and cell-autonomously required for SARS-CoV-2 infection in the olfactory epithelium, brain, and lung across diverse cell types. Therapies inhibiting or blocking ACE2 at these different sites are likely to be an effective strategy towards preventing severe COVID-19.

Alterations in hepatic transcriptome and cecum microbiota underlying potential ways to prevent early fatty liver in laying hens

Fatty liver syndrome (FLS) is a kind of nutritional metabolic disease in laying hens. Revealing FLS pathogenesis during the early period is what really makes sense for the prevention or nutritional regulation strategies. In the study, 9 healthy or naturally occurring early FLS birds were screened based on visual inspection, liver index and morphologic analysis. Liver and fresh cecal content samples were collected. Then transcriptomic and 16S rRNA technologies are applied to investigate hepatic transcriptome and cecum microbiota composition. Unpaired Student t test and some omics methods were used for statistical analysis. Results showed higher liver weight and index were found in FLS group; morphologic analysis indicated that there existed more lipid droplets in the liver of birds with FLS. Based on DESeq2 analysis, there were 229 up- and 487 down-regulated genes in the FLS group, among which most genes related to de novo fatty acid synthesis were up-regulated such as acetyl-CoA carboxylase, fatty acid synthase, stearoyl-CoA desaturase, and ELOVL fatty acid elongase 6 (ELOVL6). Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis indicated that pathways associated with lipid metabolism and liver damage were affected. 16S rRNA sequencing analysis of cecum microbiota showed that there was a significant difference between the Con and FLS groups. LEfSe analysis revealed that the relative abundance of Coprococcus, Odoribacter, Collinsella, Turicibacter, YRC22, Enterococcus, Shigella, and Bifidobacterium were down-regulated in the FLS group, whereas the abundance of Bacteroides, Mucispirillum, Butyricicoccus, Campylobacter, Akkermansia, and Clostridium were up-regulated. The KEGG enrichment from differential microbiota suggested that some metabolism-related functions were altered to some extent. Taken together, during the developmental of early fatty liver of laying hens, lipogenesis was enhanced, whereas abnormal metabolism occurs not only in lipid transportation but also in hydrolysis, which caused structural damage to the liver organ. Moreover, the dysbiosis of the cecum microbiota occurred. All of these serve as targets or provide theoretical references for the development of probiotics for fatty liver prevention in laying hens.

PDGF-BB is involved in HIF-1α/CXCR4/CXCR7 axis promoting capillarization of hepatic sinusoidal endothelial cells

Background

The activation of HIF-1α/CXCR4 pathway in liver sinusoidal endothelial cells (LSECs) could downregulate CXCR7, leading to the capillarization of LSECs to promote hepatic fibrosis. However, the mechanism between CXCR4 and CXCR7 is still undefined. The aim is to investigate the role of PDGF-BB in the dedifferentiation of LSECs and hepatic stellate cells (HSCs) activation.

Methods

The activation of HIF-1α/CXCR4 pathway in two kinds of liver fibrosis models were observed. The effects of HIF-1α, CXCR4, PDGF-BB on the dedifferentiation of LSECs were investigated by using the inhibitors of HIF-1α, CXCR4 or PDGFR-β separately or transfecting with a CXCR4 knockdown lentiviral vector. In addition, the relationship between LSECs and HSCs was demonstrated by co-culture of LSECs and HSCs using the transwell chamber.

Results

CXCR4 upregulation and CXCR7 downregulation were accompanied by LSECs capillarization and HSCs activation both in CCl₄-induced and BDL-induced fibrotic liver. In vitro, downregulation of HIF-1α significantly descreased CXCR4 and CD31 expression, and enhanced the expressions of CXCR7, CD44 and LYVE1. Downregulation of CXCR4 in LSECs significantly downregulated PDGF-BB, PDGFR-β and CD31, and enhanced CXCR7, CD44 and LYVE1 expression, while the expression of HIF-1α did not change significantly. STI571, a PDGF receptor inhibitor, could significantly downregulate PDGFR-β and increase the expression of CXCR7 to inhibit the dedifferentiation of LSECs. In addition, alleviateion the dedifferentiation of LSECs could decrease the expression of PDGFR-β of HSCs, then inhibiting the activation of HSCs.

Conclusions

This study revealed that HIF-1α/CXCR4/PDGF-BB/CXCR7 axis promoted the dedifferentiation of LSECs, consequently triggering HSCs activation and liver fibrosis.

CYLD deubiquitinates plakoglobin to promote Cx43 membrane targeting and gap junction assembly in the heart

During heart maturation, gap junctions assemble into hemichannels and polarize to the intercalated disc at cell borders to mediate electrical impulse conduction. However, the molecular mechanism underpinning cardiac gap junction assembly remains elusive. Herein, we demonstrate an important role for the deubiquitinating enzyme cylindromatosis (CYLD) in this process. Depletion of CYLD in mice impairs the formation of cardiac gap junctions, accelerates cardiac fibrosis, and increases heart failure. Mechanistically, CYLD interacts with plakoglobin and removes lysine 63-linked polyubiquitin chains from plakoglobin. The deubiquitination of plakoglobin enhances its interaction with the desmoplakin/end-binding protein 1 complex localized at the microtubule plus end, thereby promoting microtubule-dependent transport of connexin 43 (Cx43), a key component of gap junctions, to the cell membrane. These findings establish CYLD as a critical player in regulating gap junction assembly and have important implications in heart development and diseases.