A FRET method for investigating dimer/monomer status and conformation of the UVR8 photoreceptor

The photoreceptor UVR8 has a pivotal role in mediating plant responses to UV-B wavelengths. Dimeric UVR8 dissociates into monomers following UV-B photoreception, and there is evidence that this process is accompanied by conformational changes that may facilitate interaction of UVR8 with other proteins to initiate signaling. Hence monitoring UVR8 dimer/monomer status and conformation is key to understanding UVR8 action. Here we have used Fluorescence Resonance Energy Transfer (FRET) to study these processes in both wild-type and mutant UVR8 proteins in vivo. UVR8 was fused to GFP and mCherry at the C- and N-termini, respectively and both the FRET efficiency and loss of GFP fluorescence after photobleaching were measured. In addition, measurements were made for UVR8 fused to either GFP or mCherry to eliminate intra-molecular FRET signals. The results indicate that dissociation of UVR8 dimer to monomer principally accounts for the loss of FRET signal for wild-type UVR8 and there is little evidence of a contribution from conformational change in vivo. Examination of plants expressing UVR8W285F and UVR8D96N,D107N are consistent with these mutant proteins being constitutively dimeric and monomeric, respectively. The methods employed here will be valuable for monitoring UVR8 dimer/monomer status in vivo in relation to signaling, and will facilitate characterization of dimer/monomer status and conformation of further UVR8 mutants

A dynamic model of UVR8 photoreceptor signaling in UV-B acclimated Arabidopsis

The photoreceptor UVR8 mediates numerous photomorphogenic responses of plants to UV‐B wavelengths by regulating transcription. Studies with purified UVR8 and seedlings not previously exposed to UV‐B have generated a model for UVR8 action in which dimeric UVR8 rapidly monomerises in response to UV‐B exposure to initiate signaling. However, the mechanism of UVR8 action in UV‐B‐acclimated plants growing under photoperiodic conditions, where UVR8 exists in a dimer/monomer photo‐equilibrium, is poorly understood. We examined UVR8 dimer/monomer status, gene expression responses, amounts of key UVR8 signaling proteins and their interactions with UVR8 in UV‐B‐acclimated Arabidopsis. We show that in UV‐B‐acclimated plants UVR8 can mediate a response to a 15‐fold increase in UV‐B without any increase in abundance of UVR8 monomer. Following transfer to elevated UV‐B, monomers show increased interaction with both COP1, to initiate signaling, and RUP2, to maintain the photo‐equilibrium when the dimer/monomer cycling rate increases. Native RUP1 is present in low abundance compared with RUP2. We present a model for UVR8 action in UV‐B‐acclimated plants growing in photoperiodic conditions that incorporates dimer and monomer photoreception, dimer/monomer cycling, abundance of native COP1 and RUP proteins, and interactions of the monomer population with COP1, RUP2 and potentially other proteins

CT radiomics model combined with clinical and radiographic features for discriminating peripheral small cell lung cancer from peripheral lung adenocarcinoma

PurposeExploring a non-invasive method to accurately differentiate peripheral small cell lung cancer (PSCLC) and peripheral lung adenocarcinoma (PADC) could improve clinical decision-making and prognosis.MethodsThis retrospective study reviewed the clinicopathological and imaging data of lung cancer patients between October 2017 and March 2022. A total of 240 patients were enrolled in this study, including 80 cases diagnosed with PSCLC and 160 with PADC. All patients were randomized in a seven-to-three ratio into the training and validation datasets (170 vs. 70, respectively). The least absolute shrinkage and selection operator regression was employed to generate radiomics features and univariate analysis, followed by multivariate logistic regression to select significant clinical and radiographic factors to generate four models: clinical, radiomics, clinical-radiographic, and clinical-radiographic-radiomics (comprehensive). The Delong test was to compare areas under the receiver operating characteristic curves (AUCs) in the models.ResultsFive clinical-radiographic features and twenty-three selected radiomics features differed significantly in the identification of PSCLC and PADC. The clinical, radiomics, clinical-radiographic and comprehensive models demonstrated AUCs of 0.8960, 0.8356, 0.9396, and 0.9671 in the validation set, with the comprehensive model having better discernment than the clinical model (P=0.036), the radiomics model (P=0.006) and the clinical–radiographic model (P=0.049).ConclusionsThe proposed model combining clinical data, radiographic characteristics and radiomics features could accurately distinguish PSCLC from PADC, thus providing a potential non-invasive method to help clinicians improve treatment decisions

Functional analysis of the UV-B photoreceptor UVR8 in Arabidopsis thaliana

No abstract available

Cysteines have a role in conformation of the UVR8 photoreceptor

The UVR8 photoreceptor mediates plant responses to UV-B wavelengths. The UVR8 dimer dissociates into monomers following UV-B photoreception, a process accompanied by conformational changes that facilitate interaction of UVR8 with proteins that initiate responses. However, the importance of particular amino acids in maintaining UVR8 conformation and modulating protein interactions is poorly understood. Here we examine the roles of cysteine amino acids C231 and C335 in UVR8 structure and function. UVR8C231S,C335S mutant protein forms dimers and monomerises similarly to wild-type UVR8. UVR8C231S,C335S interacts with CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1) in plants to initiate photomorphogenic responses to UV-B, although the interaction is weaker when examined in yeast 2-hybrid assays. Similarly, the interaction of UVR8C231S,C335S with REPRESSOR OF UV-B PHOTOMORPHOGENESIS (RUP) proteins is weaker in both plants and yeast compared to wild-type UVR8. Re-dimerisation of UVR8 in plants, which is mediated by RUP proteins, occurs with reduced efficiency in UVR8C231S,C335S. Fluorescence Resonance Energy Transfer (FRET) analysis indicates that UVR8C231S,C335S has an altered conformation in plants, in that the N- and C-termini appear closer together, which may explain the altered protein interactions

Semantic processing features and schizotypal traits: A test-retest study

Semantic processing abnormalities have been observed across the schizophrenia spectrum. However, it is unclear whether associations between semantic processing measures and schizotypal traits are stable over time. The current study aimed to explore the temporal stability of semantic processing measures and their correlations with schizotypal traits. In this study, we used the Schizotypal Personality Questionnaire (SPQ) to assess schizotypal traits and explored the association between schizotypal traits and semantic processing measures (i.e., N400- a large negativity with a broad scalp distribution, peaking around 400 ms after the presentation of any potentially meaningful stimulus) at baseline (Time 1; n = 63) and 3 months later (Time 2; n = 44). Repeated-measure ANOVA was conducted to examine the stability of the semantic processing measures; the intraclass correlation coefficient (ICC) was used to examine test-retest reliability; Pearson's r was calculated to explore associations between schizotypal traits and semantic processing measures. Results showed that both behavioral (reaction times) and N400 measures showed high reliability but low temporal stability. N400 latency for semantically unrelated stimuli was correlated with the cognitive-perceptual and the disorganized dimensions of schizotypal traits at Time 2. In conclusion, semantic processing measures generally showed good reliability. Schizotypal traits were correlated with N400 latencies in the current sample, but further studies are needed to examine whether this association is stable

Evaluation of Survival Outcomes Among Black and White Patients with Metastatic Castration-resistant Prostate Cancer: A Systematic Review and Meta-analysis

Context: Data on racial disparities among patients with metastatic castration-resistant prostate cancer (mCRPC) are limited and there is no uniform conclusion on differences by race in this setting. Objective: To provide the latest evidence on racial disparities in survival outcomes between Black and White patients receiving systemic therapies for mCRPC. Evidence acquisition: Our study was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. We systematically searched the PubMed, Web of Science, and Cochrane Library databases up to September 2023 to identify potentially relevant studies. Overall survival (OS) and progression-free survival (PFS) were the outcomes of interest. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were evaluated. Evidence synthesis: Nine studies involving 9462 patients with mCRPC (2058 Black and 7404 White men) met the eligibility criteria and were included. Pooled estimates demonstrated significantly better OS for Black than for White men (HR 0.75, 95% CI 0.70–0.80; p < 0.0001). The results were similar in a subgroup of men receiving androgen receptor–targeted therapies (HR 0.72, 95% CI 0.66–0.78; p < 0.0001) and a subgroup of men receiving other treatments (HR 0.79, 95% CI 0.71–0.88; p < 0.0001). Likewise, significantly favorable PFS was observed for Black men receiving ARTs in comparison to their White counterparts (HR 0.84, 95% CI 0.71–0.99; p = 0.0373). Conclusions: Overall, our meta-analysis of survival outcomes for men with mCRPC stratified by race revealed a significant survival benefit for Black men in comparison to their White counterparts, regardless of systemic therapeutic agent. Patient summary: Both biological and nonbiological factors could account for racial differences in the efficacy of systemic treatments for metastatic prostate cancer that is resistant to hormone therapy. Our review provides the latest reliable evidence showing better survival outcomes for Black than for White men. The results will be helpful in further understanding the molecular mechanisms that might explain racial differences in this disease stage and in planning treatment

The Effects of Positioning on the Volume/Location of the Internal Jugular Vein Using 2-Dimensional Tracked Ultrasound

© 2019 Objective: To investigate the effects of different positioning on the volume/location of the internal jugular vein (IJV) using 2-dimensional (2D) tracked ultrasound. Design: This was a prospective, observational study. Setting: Local research institute. Participants: Healthy volunteers. Interventions: Twenty healthy volunteers were scanned in the following 6 positions: (1) supine with head neutral, rotated 15 and 30 degrees to the left and (2) 5-, 10-, and 15-degree Trendelenburg position with head neutral. In each position the volunteer\u27s neck was scanned using a 2D ultrasound probe tracked with a magnetic tracker. These spatially tracked 2D images were collected and reconstructed into a 3D volume of the IJV and carotid artery. This 3D ultrasound volume then was segmented to obtain a 3D surface on which measurements and calculations were performed. Measurements and Main Results: The measurements included average cross-section area (CSA), CSA along the length of IJV, and average overlap rate. CSA (mm2) in the supine and 5-, 10-, and 15-degree Trendelenburg positions were as follows: 86.7 ± 44.8, 104.3 ± 54.5, 119.1 ± 58.6, and 133.7 ± 53.3 (p \u3c 0.0001). CSA enlarged with the increase of Trendelenburg degree. Neither Trendelenburg position nor head rotation showed a correlation with overlap rate. Conclusions: Trendelenburg position significantly increased the CSA of the IJV, thus facilitating IJV cannulation. This new 3D reconstruction method permits the creation of a 3D volume through a tracked 2D ultrasound scanning system with image acquisition and integration and may prove useful in providing the user with a “road map” of the vascular anatomy of a patient\u27s neck or other anatomic structures

Integrated Analysis of Gut Microbiome and Adipose Transcriptome Reveals Beneficial Effects of Resistant Dextrin from Wheat Starch on Insulin Resistance in Kunming Mice

Systemic chronic inflammation is recognized as a significant contributor to the development of obesity-related insulin resistance. Previous studies have revealed the physiological benefits of resistant dextrin (RD), including obesity reduction, lower fasting glucose levels, and anti-inflammation. The present study investigated the effects of RD intervention on insulin resistance (IR) in Kunming mice, expounding the mechanisms through the gut microbiome and transcriptome of white adipose. In this eight-week study, we investigated changes in tissue weight, glucose–lipid metabolism levels, serum inflammation levels, and lesions of epididymal white adipose tissue (eWAT) evaluated via Hematoxylin and Eosin (H&E) staining. Moreover, we analyzed the gut microbiota composition and transcriptome of eWAT to assess the potential protective effects of RD intervention. Compared with a high-fat, high-sugar diet (HFHSD) group, the RD intervention significantly enhanced glucose homeostasis (e.g., AUC-OGTT, HOMA-IR, p p p Parabacteroides, Faecalibaculum, and Muribaculum, p Colidextribacter, p < 0.05). Moreover, the RD intervention had a noticeable effect on the gene transcription profile of eWAT, and KEGG enrichment analysis revealed that differential genes were enriched in PI3K/AKT, AMPK, in glucose-lipid metabolism, and in the regulation of lipolysis in adipocytes signaling pathways. The findings demonstrated that RD not only ameliorated IR, but also remodeled the gut microbiota and modified the transcriptome profile of eWAT