The RNA-binding domain of DCL3 is required for long-distance RNAi signaling.

Small RNA (sRNA)-mediated RNA silencing (also known as RNA interference, or RNAi) is a conserved mechanism in eukaryotes that includes RNA degradation, DNA methylation, heterochromatin formation and protein translation repression. In plants, sRNAs can move either cell-to-cell or systemically, thereby acting as mobile silencing signals to trigger noncell autonomous silencing. However, whether and what proteins are also involved in noncell autonomous silencing have not been elucidated. In this study, we utilized a previously reported inducible RNAi plant, PDSi, which can induce systemic silencing of the endogenous PDS gene, and we demonstrated that DCL3 is involved in systemic PDS silencing through its RNA binding activity. We confirmed that the C-terminus of DCL3, including the predicted RNA-binding domain, is capable of binding short RNAs. Mutations affecting RNA binding, but not processing activity, reduced systemic PDS silencing, indicating that DCL3 binding to RNAs is required for the induction of systemic silencing. Cucumber mosaic virus infection assays showed that the RNA-binding activity of DCL3 is required for antiviral RNAi in systemically noninoculated leaves. Our findings demonstrate that DCL3 acts as a signaling agent involved in noncell autonomous silencing and an antiviral effect in addition to its previously known function in the generation of 24-nucleotide sRNAs. Supplementary Information: The online version contains supplementary material available at 10.1007/s42994-023-00124-6.

Erratum: Publisher Correction: The RNA-binding domain of DCL3 is required for long-distance RNAi signaling.

[This corrects the article DOI: 10.1007/s42994-023-00124-6.].

Heat transfer and pressure drop characteristic research of sine wavy flying-wing fins.

In recent years, heat transfer enhancement of heat exchange equipment has attracted more and more attention. In this paper, the heat transfer and pressure drop characteristics of sine wavy flying-wing fins are studied by numerical method. The objective is to improve the integrated heat transfer and pressure drop performance of sine wavy flying-wing fins. The degrees of freedom of fin sizes include fin pitch to fin height ratio fp/fh, fin height to fin wavelength ratio fh/W, fin amplitude to fin pitch ratio 2A/fp and fin inclined angle α. The results show that among the calculated 17 flying-wing fins, the optimal values of fp/fh, fh/W, 2A/fp, and α are 0.5, 0.4, 1.9 and 70° respectively. The optimized SWFWF simulation model is established, and the average JF factor is 1.307, which is about 10.9% higher than that of Fin 05 (JF = 1.18). Multiple linear regression is used to obtain the correlations of flow and heat transfer characteristics of flying-wing fins. The average deviation of the correlations for j and f are 0.85% and 4.9% respectively. The correlations can be used for the design and optimization of sine wavy flying-wing fins.

DeSUMOylation of a Verticillium dahliae enolase facilitates virulence by derepressing the expression of the effector VdSCP8.

The soil-borne fungus Verticillium dahliae, the most notorious plant pathogen of the Verticillium genus, causes vascular wilts in a wide variety of economically important crops. The molecular mechanism of V. dahliae pathogenesis remains largely elusive. Here, we identify a small ubiquitin-like modifier (SUMO)-specific protease (VdUlpB) from V. dahliae, and find that VdUlpB facilitates V. dahliae virulence by deconjugating SUMO from V. dahliae enolase (VdEno). We identify five lysine residues (K96, K254, K259, K313 and K434) that mediate VdEno SUMOylation, and SUMOylated VdEno preferentially localized in nucleus where it functions as a transcription repressor to inhibit the expression of an effector VdSCP8. Importantly, VdUlpB mediates deSUMOylation of VdEno facilitates its cytoplasmic distribution, which allows it to function as a glycolytic enzyme. Our study reveals a sophisticated pathogenic mechanism of VdUlpB-mediated enolase deSUMOylation, which fortifies glycolytic pathway for growth and contributes to V. dahliae virulence through derepressing the expression of an effector.

Production, identification, in silico analysis, and cytoprotection on H2O2-induced HUVECs of novel angiotensin-I-converting enzyme inhibitory peptides from Skipjack tuna roes.

Background: Exceeding 50% tuna catches are regarded as byproducts in the production of cans. Given the high amount of tuna byproducts and their environmental effects induced by disposal and elimination, the valorization of nutritional ingredients from these by-products receives increasing attention. Objective: This study was to identify the angiotensin-I-converting enzyme (ACE) inhibitory (ACEi) peptides from roe hydrolysate of Skipjack tuna (Katsuwonus pelamis) and evaluate their protection functions on H2O2-induced human umbilical vein endothelial cells (HUVECs). Methods: Protein hydrolysate of tuna roes with high ACEi activity was prepared using flavourzyme, and ACEi peptides were isolated from the roe hydrolysate using ultrafiltration and chromatography methods and identified by ESI/MS and Procise Protein/Peptide Sequencer for the N-terminal amino acid sequence. The activity and mechanism of action of isolated ACEi peptides were investigated through molecular docking and cellular experiments. Results: Four ACEi peptides were identified as WGESF (TRP3), IKSW (TRP6), YSHM (TRP9), and WSPGF (TRP12), respectively. The affinity of WGESF (TRP3), IKSW (TRP6), YSHM (TRP9), and WSPGF (TRP12) with ACE was -8.590, -9.703, -9.325, and -8.036 kcal/mol, respectively. The molecular docking experiment elucidated that the significant ACEi ability of WGESF (TRP3), IKSW (TRP6), YSHM (TRP9), and WSPGF (TRP12) was mostly owed to their tight bond with ACE's active sites/pockets via hydrophobic interaction, electrostatic force and hydrogen bonding. Additionally, WGESF (TRP3), IKSW (TRP6), YSHM (TRP9), and WSPGF (TRP12) could dramatically elevate the Nitric Oxide (NO) production and bring down endothelin-1 (ET-1) secretion in HUVECs, but also abolish the opposite impact of norepinephrine (0.5 µM) on the production of NO and ET-1. Moreover, WGESF (TRP3), IKSW (TRP6), YSHM (TRP9), and WSPGF (TRP12) could lower the oxidative damage and apoptosis rate of H2O2-induced HUVECs, and the mechanism indicated that they could increase the content of NO and activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) to decrease the generation of reactive oxygen species (ROS) and malondialdehyde (MDA). Conclusion: WGESF (TRP3), IKSW (TRP6), YSHM (TRP9), and WSPGF (TRP12) are beneficial ingredients for healthy products ameliorating hypertension and cardiovascular diseases.

Noninvasive evaluation of hypoxia in rabbit VX2 lung transplant tumors using spectral CT parameters and texture analysis.

AIM: Noninvasive evaluation of hypoxia in rabbit VX2 lung transplant tumors using spectral CT parameters and texture analysis. MATERIALS AND METHODS: Twenty-five VX2 lung transplant tumors of twenty-two rabbits were included in the study. Contrast-enhanced spectral CT scanning in the arterial phase (AP) and venous phase (VP) was performed. Tumors were divided into strong and weak hypoxic groups by hypoxic probe staining results. Spectral CT image-related parameters [70 keV CT value, normalized iodine concentration (NIC), slope of spectral HU curve (λHU)] were measured and the texture analysis on the monochromatic images was performed. Imaging parameters and texture features between tumors with different hypoxic degrees were compared and their diagnostic efficacies for predicting hypoxia in lung cancers were analyzed using receiver operating characteristic (ROC) curve. RESULTS: NIC in VP and λHU in VP of the strong hypoxic group were significantly higher than those in the weak hypoxic group (p < 0.05). For the texture features, entropy in VP and kurtosis in AP were significantly different between the two hypoxic groups. According to ROC analysis, λHU in VP had a better diagnostic ability for predicting hypoxia in tumors [Area Under Curve (AUC): 0.883, sensitivity: 85.7%, specificity: 100%]. The combination of four features improved AUC to 0.955. CONCLUSION: NIC in VP, λHU in VP, entropy in VP and kurtosis in AP have certain values in predicting tumor hypoxia and a combination of image parameters and texture features improves diagnostic efficiency.

Diffusion-weighted MRI and 18F-FDG PET/CT in assessing the response to neoadjuvant chemoradiotherapy in locally advanced esophageal squamous cell carcinoma.

BACKGROUND: Neoadjuvant chemoradiotherapy (nCRT) followed by surgery is a currently widely used strategy for locally advanced esophageal cancer (EC). However, the conventional imaging methods have certain deficiencies in the evaluation and prediction of the efficacy of nCRT. This study aimed to explore the value of functional imaging in predicting the response to neoadjuvant chemoradiotherapy (nCRT) in locally advanced esophageal squamous cell carcinoma (ESCC). METHODS: Fifty-four patients diagnosed with locally advanced ESCC from August 2017 to September 2019 and treated with nCRT were retrospectively analyzed. DW-MRI scanning was performed before nCRT, at 10-15 fractions of radiotherapy, and 4-6 weeks after the completion of nCRT. 18F-FDG PET/CT scans were performed before nCRT and 4-6 weeks after the completion of nCRT. These 18F-FDG PET/CT and DW-MRI parameters and relative changes were compared between patients with pathological complete response (pCR) and non-pCR. RESULTS: A total of 8 of 54 patients (14.8%) were evaluated as disease progression in the preoperative assessment. The remaining forty-six patients underwent operations, and the pathological assessments of the surgical resection specimens demonstrated pathological complete response (pCR) in 10 patients (21.7%) and complete response of primary tumor (pCR-T) in 16 patients (34.8%). The change of metabolic tumor volume (∆MTV) and change of total lesion glycolysis (∆TLG) were significantly different between patients with pCR and non-pCR. The SUVmax-Tpost, MTV-Tpost, and TLG-Tpost of esophageal tumors in 18F-FDG PET/CT scans after neoadjuvant chemoradiotherapy and the ∆ SUVmax-T and ∆MTV-T were significantly different between pCR-T versus non-pCR-T patients. The esophageal tumor apparent diffusion coefficient (ADC) increased after nCRT; the ADCduring, ADCpost and ∆ADCduring were significantly different between pCR-T and non-pCR-T groups. ROC analyses showed that the model that combined ADCduring with TLG-Tpost had the highest AUC (0.914) for pCR-T prediction, with 90.0% and 86.4% sensitivity and specificity, respectively. CONCLUSION: 18F-FDG PET/CT is useful for re-staging after nCRT and for surgical decision. Integrating parameters of 18F-FDG PET/CT and DW-MRI can identify pathological response of primary tumor to nCRT more accurately in ESCC.

Determining the invasiveness of pure ground-glass nodules using dual-energy spectral computed tomography.

BACKGROUND: The present work aimed to investigate the clinical application of using quantitative parameters generated in the unenhanced phase (UP) and venous phase (VP) in dual-energy spectral CT for differentiating the invasiveness of pure ground-glass nodule (pGGN). METHODS: Sixty-two patients with 66 pGGNs who underwent preoperative dual-energy spectral CT in UP and VP were evaluated retrospectively. Nodules were divided into three groups based on pathology: adenocarcinoma in situ (AIS, n=19), minimally invasive adenocarcinoma (MIA, n=22) (both in the preinvasive lesion group) and invasive adenocarcinoma (IA, n=25). The iodine concentration (IC) and water content (WC) in nodules were measured in material decomposition images. The nodule CT numbers and slopes(k) were measured on monochromatic images. All measurements, including the maximum diameter of nodules were statistically compared between the AIS-MIA group and IA group. RESULTS: There were significant differences of WC in VP between AIS-MIA group and IA group (P<0.05). The CT attenuation values of the 40-140 keV monochromatic images in UP and VP were significantly higher for the invasive nodules. Logistic regression analysis showed that the maximum nodule diameter [odd ratio (OR) =1.21, 95% CI: 1.050-1.400, P<0.01] and CT number in 130 keV images in venous phase (OR =1.03, 95% CI: 1.014-1.047, P<0.001) independently predicted histological invasiveness. CONCLUSIONS: The quantitative parameters in dual-energy spectral CT in the unenhanced phase and venous phase provide useful information in differentiating preinvasive lesion group from IA group of pGGN, especially the maximum nodule diameter and CT number in the 130 keV images in the venous phase.

Differentiation of lung cancers from inflammatory masses with dual-energy spectral CT imaging.

RATIONALE AND OBJECTIVES: To investigate the value of dual-energy spectral computed tomography (DESCT) in the quantitative differentiation between pulmonary malignant masses and inflammatory masses. MATERIALS AND METHODS: This study was an institutional review board-approved study, and written informed consent was obtained from all patients. Sixty patients with 35 lung cancers and 25 inflammatory masses underwent DESCT scan during arterial phase (AP) and venous phase (VP). CT numbers of net enhancement in 70 keV monochromatic images in central and peripheral regions of masses and their differences (dCT) were measured. Iodine concentrations in the two regions were measured and normalized to the aorta as normalized iodine concentrations (NICs). The slopes of spectral attenuation curves (λHU) in the two regions were also calculated. The two-sample t test was used to compare quantitative parameters. Receiver operating characteristic (ROC) curves were generated to calculate sensitivity and specificity. RESULTS: CT numbers of net enhancement and NICs in central regions, and λHU values both in the central and peripheral region of lung cancers were significantly lower than those of inflammatory masses during AP and VP. On the other hand, the dCT values of lung cancers were higher than that of inflammatory masses. NIC value in the central regions in VP had the highest sensitivity (86%) and specificity (100%) in differentiating malignant masses from inflammatory masses. CONCLUSIONS: DESCT imaging with quantitative parameters such as CT numbers of 70 keV monochromatic images, NIC, and λHU may be a new method for differentiating lung cancers from inflammatory masses.

Pulmonary embolism detection and characterization through quantitative iodine-based material decomposition images with spectral computed tomography imaging.

OBJECTIVES: To assess the diagnostic value of pulmonary embolism (PE) detection and characterization through quantitative iodine-based material decomposition images with spectral computed tomography (CT) imaging. MATERIALS AND METHODS: Fifty-three patients underwent CT pulmonary angiography (CTPA) with spectral imaging mode with the simultaneous acquisition of 80 kVp and 140 kVp on a GE Discovery CT750HD scanner to generate monochromatic CTPA and material decomposition images. CTPA images were reviewed for the presence, localization, and degree (occlusive or nonocclusive) of PE. The iodine distribution in the lung parenchyma on the iodine-based material decomposition images was used to identify perfusion defects, which were then correlated to the CTPA findings. The iodine densities for the perfusion defects and the normal lung parenchyma were measured and statistically compared. Twelve PE patients underwent anticoagulation, and the iodine densities for the perfusion defects before and after the treatment were also measured and compared. The receiver operating characteristics curve was generated to assess the differential diagnostic performances of iodine density in distinguishing the presence or absence of PE and the occlusive or nonocclusive PE. RESULTS: A total of 93 clots (51 occlusive and 42 nonocclusive) were found in 19 patients with lobar (26), segmental (54), or subsegmental (13) distribution. CTPA identified 88 clots initially and 5 more retrospectively with the help of iodine mapping. Thirty-three of 34 normal CTPA patients had symmetric iodine distribution. All occlusive clots and 11 nonocclusive clots showed clear evidence of iodine distribution defects. There was a significant difference for the iodine density among normal lung parenchyma (1.89 mg/mL [0.85-3.29 mg/mL]), nonocclusive perfusion defects (0.83 mg/mL [0.44-1.26 mg/mL]), and occlusive perfusion defects (0.27 mg/mL [0.00-0.62 mg/mL]) (P < 0.001). The iodine densities of perfusion defects before and after anticoagulation were significantly different (P < 0.001). Receiver operating characteristics analyses showed high discriminatory power for using the quantification of iodine density in distinguishing the presence or absence of PE and the occlusive or nonocclusive PE. CONCLUSIONS: Spectral CT imaging generated both monochromatic CTPA images for morphologic analysis of PE and material decomposition images for quantitative depiction of pulmonary blood flow and perfusion defects. Quantification of iodine density may be used as a predictor in distinguishing the presence or absence of PE and the severity of PE.

[Gemstone computed tomography in the evaluation of material distribution in pulmonary parenchyma for pulmonary embolism].

OBJECTIVE: To present our initial experiences with pulmonary high-definition multidetector computed tomography (HDCT) in patients with acute venous thromboembolism (AVTE) to evaluate their corresponding clinical manifestations. METHODS: Since December 2009 to March 2010, 23 AVTE patients underwent HDCT at our hospital. Pulmonary embolism (PE) was diagnosed based on the 3D-reconstructed images of computed tomography pulmonary angiography (CTPA). The post processed data were collected by spectral imaging system software to detect the iodine distribution maps. Perfusion defects, calculated as the values of iodine content, were compared with those of normal lung parenchymal perfusion in the absence of PE. RESULTS: Among them, 14 AVTE patients were definitely diagnosed with PE. Prior to anticoagulant therapy, their values of iodine content in defective perfusion area were significantly lower than those in normal perfusion area. After a 3-month anticoagulant therapy, the values of iodine content for the defective perfusion area increased significantly (P < 0.05). There was no significant correlation between the values of iodine content for segmental/subsegmental filling defect area and clinical risk score of DVT (r = 2.68, P > 0.05). But there was a significant negative correlation between the values of iodine content for segmental/subsegmental filling defection area and clinical probability score of PE (r = 0.78, P < 0.05). CONCLUSION: HDCT is a promising modality of visualizing pulmonary microvasculature as a correlative manifestation of regional perfusion. PE results in hypoperfusion with decreased values of iodine content in affected lung parenchyma. Hemodynamic changes in affected areas correlate with the severity of clinical manifestations of PE.