The role of Interleukin-22 in severe acute pancreatitis.

Severe acute pancreatitis (SAP) begins with premature activation of enzymes, promoted by the immune system, triggering a potential systemic inflammatory response that leads to organ failure with increased mortality and a bleak prognosis. Interleukin-22 (IL-22) is a cytokine that may have a significant role in SAP. IL-22, a member of the IL-10 cytokine family, has garnered growing interest owing to its potential tissue-protective properties. Recently, emerging research has revealed its specific effects on pancreatic diseases, particularly SAP. This paper provides a review of the latest knowledge on the role of IL-22 and its viability as a therapeutic target in SAP.

Associations of Intrapancreatic Fat Deposition With Incident Diseases of the Exocrine and Endocrine Pancreas: A UK Biobank Prospective Cohort Study.

INTRODUCTION: To investigate whether increased intrapancreatic fat deposition (IPFD) heightens the risk of diseases of the exocrine and endocrine pancreas. METHODS: A prospective cohort study was conducted using data from the UK Biobank. IPFD was quantified using MRI and a deep learning-based framework called nnUNet. The prevalence of fatty change of the pancreas (FP) was determined using sex- and age-specific thresholds. Associations between IPFD and pancreatic diseases were assessed with multivariate Cox-proportional hazard model adjusted for age, sex, ethnicity, body mass index, smoking and drinking status, central obesity, hypertension, dyslipidemia, liver fat content, and spleen fat content. RESULTS: Of the 42,599 participants included in the analysis, the prevalence of FP was 17.86%. Elevated IPFD levels were associated with an increased risk of acute pancreatitis (hazard ratio [HR] per 1 quintile change 1.513, 95% confidence interval [CI] 1.179-1.941), pancreatic cancer (HR per 1 quintile change 1.365, 95% CI 1.058-1.762) and diabetes mellitus (HR per 1 quintile change 1.221, 95% CI 1.132-1.318). FP was also associated with a higher risk of acute pancreatitis (HR 3.982, 95% CI 2.192-7.234), pancreatic cancer (HR 1.976, 95% CI 1.054-3.704), and diabetes mellitus (HR 1.337, 95% CI 1.122-1.593, P = 0.001). DISCUSSION: FP is a common pancreatic disorder. Fat in the pancreas is an independent risk factor for diseases of both the exocrine pancreas and endocrine pancreas.

Extraordinary Structural Reconstruction of Nanolaminated Ta2FeC MAX Phase for Enhanced Oxygen Evolution Performance.

Renewable energy technologies, such as water splitting, heavily depend on the oxygen evolution reaction (OER). Nanolaminated ternary compounds, referred to as MAX phases, show great promise for creating efficient electrocatalysts for OER. However, their limited intrinsic oxidative resistance hinders the utilization of conductivity in Mn+1Xn layers, leading to reduced activity. In this study, a method is proposed to improve the poor inoxidizability of MAX phases by carefully adjusting the elemental composition between Mn+1Xn layers and single-atom-thick A layers. The resulting Ta2FeC catalyst demonstrates superior performance compared to conventional Fe/C-based catalysts with a remarkable record-low overpotential of 247 mV (@10 mA cm-2) and sustained activity for over 240 h. Notably, during OER processing, the single-atom-thick Fe layer undergoes self-reconstruction and enrichment from the interior of the Ta2FeC MAX phase toward its surface, forming a Ta2FeC@Ta2C@FeOOH heterostructure. Through density functional theory (DFT) calculations, this study has found that the incorporation of Ta2FeC@Ta2C not only enhances the conductivity of FeOOH but also reduces the covalency of Fe─O bonds, thus alleviating the oxidation of Fe3+ and O2-. This implies that the Ta2FeC@Ta2C@FeOOH heterostructure experiences less lattice oxygen loss during the OER process compared to pure FeOOH, leading to significantly improved stability. These results highlight promising avenues for further exploration of MAX phases by strategically engineering M- and A-site engineering through multi-metal substitution, to develop M2AX@M2X@AOOH-based catalysts for oxygen evolution.

Consistent community assembly but contingent species pool effects drive ß-diversity patterns of multiple microbial groups in desert biocrust systems.

One of the key goals of ecology is to understand how communities are assembled. The species co-existence theory suggests that community ß-diversity is influenced by species pool and community assembly processes, such as environmental filtering, dispersal events, ecological drift and biotic interactions. However, it remains unclear whether there are similar ß-diversity patterns among different soil microbial groups and whether all these mechanisms play significant roles in mediating ß-diversity patterns. By conducting a broad survey across Chinese deserts, we aimed to address these questions by investing biological soil crusts (biocrusts). Through amplicon-sequencing, we acquired ß-diversity data for multiple microbial groups, that is, soil total bacteria, diazotrophs, phoD-harbouring taxa, and fungi. Our results have shown varying distance decay rates of ß-diversity across microbial groups, with soil total bacteria showing a weaker distance-decay relationship than other groups. The impact of the species pool on community ß-diversity varied across microbial groups, with soil total bacteria and diazotrophs being significantly influenced. While the contributions of specific assembly processes to community ß-diversity patterns varied among different microbial groups, significant effects of local community assembly processes on ß-diversity patterns were consistently observed across all groups. Homogenous selection and dispersal limitation emerged as crucial processes for all groups. Precipitation and soil C:P were the key factors mediating ß-diversity for all groups. This study has substantially advanced our understanding of how the communities of multiple microbial groups are structured in desert biocrust systems.

Isoliquiritigenin limits inflammasome activation of macrophage via docking into Syk to alleviate murine non-alcoholic fatty liver disease.

Isoliquiritigenin (ISL) is a chalcone-type flavonoid derived from the root of licorice with antioxidant, anti-inflammatory, anti-tumour and neuroprotective properties. ISL has been proven to downregulate the productions of IL-1ß, TNF-α and IL-6 by macrophages. However, detailed molecular mechanisms of this modulation remain elusive. Here, ISL suppressed Syk phosphorylation and CD80, CD86, IL-1ß, TNF-α and IL-6 expressions in lipopolysaccharide-stimulated macrophages ex vivo. ApoC3-transgenic (ApoC3TG) mice had more activated macrophages. ISL was also able to downregulate the inflammatory activities of macrophages from ApoC3TG mice. Administration of ISL inhibited Syk activation and inflammatory activities of macrophages in ApoC3TG mice in vivo. The treatment of ISL further alleviated MCD-induced non-alcoholic fatty liver disease (NAFLD) in wild-type and ApoC3TG mice, accompanied by less recruitment and activation of liver macrophages. Due to the inhibition of Syk phosphorylation, ISL-treated macrophages displayed less production of cytoplasmic ROS, NLRP3, cleaved-GSDMD and cleaved-IL-1ß, suggesting less inflammasome activation. Finally, the molecular docking study demonstrated that ISL bound to Syk directly with the Kd of 1.273 × 10-8 M. When the Syk expression was knocked down by its shRNA, the inhibitory effects of ISL on activated macrophages disappeared, indicating that Syk was at least one of key docking-molecules of ISL. Collectively, ISL could alleviate MCD-induced NAFLD in mice involved with the inhibition of macrophage inflammatory activity by the blockade of Syk-induced inflammasome activation.

Immune Cell Infiltration Types as Biomarkers for the Recurrence Diagnosis and Prognosis of Bladder Cancer.

This study aimed to investigate the role of infiltrating immune cell types in diagnosing and predicting bladder cancer recurrence. This study mainly applied some algorithms, including Estimate the Proportion of Immune and Cancer Cells (EPIC), support vector machine-recursive feature elimination (SVM-RFE), random forest out-of-bag (RF-OOB) and least absolute shrinkage and selection operator (LASSO)-Cox regression analysis. We found six immune infiltrating cell types significantly associated with recurrence prognosis and two independent clinical prognostic factors. Infiltrating immune cell types (IICTs) based on the prognostic immune risk score (pIRS) models may provide significant biomarkers for the diagnosis and prognostic prediction of bladder cancer recurrence.

Systemic conversion therapies for initially unresectable hepatocellular carcinoma: a systematic review and meta-analysis.

BACKGROUND: Systemic conversion therapy provides patients with initially unresectable hepatocellular carcinoma (HCC) the chance to salvage radical liver resection and superior survival outcomes, but the optimal conversion strategy is unclear. METHODS: A systematic literature search was conducted on PubMed, EMBASE, Web of Science, Scopus, and the Cochrane Library between 2007 and 2024 focusing on studies reporting conversion therapy for HCC. The treatment groups were divided into Tyrosine kinase inhibitors (TKI), TKI plus loco-regional therapy (LRT), TKI plus anti-PD-1 therapy (TKI + PD-1), TKI + PD-1 + LRT, immune checkpoint inhibitors (ICI) plus LRT, and Atezolizumab plus bevacizumab (A + T) groups. The conversion to surgery rate (CSR), objective response rate (ORR), grade ≥ 3 treatment-related adverse events (AEs), overall survival (OS) and progression-free survival (PFS) were analyzed. RESULTS: 38 studies and 4,042 patients were included. The pooled CSR were 8% (95% CI, 5-12%) in TKI group, 13% (95% CI, 8-19%) in TKI + LRT group, 28% (95% CI, 19-37%) in TKI + PD-1 group, 33% (95% CI, 25-41%) in TKI + PD-1 + LRT group, 23% (95% CI, 1-46%) in ICI + LRT group, and 5% (95% CI, 3-8%) in A + T group, respectively. The pooled HR for OS (0.45, 95% CI, 0.35-0.60) and PFS (0.49, 95% CI, 0.35-0.70) favored survival benefit of conversion surgery. Subgroup analysis revealed that lenvatinib + PD-1 + LRT conferred higher CSR of 35% (95% CI, 26-44%) and increased ORR of 70% (95% CI, 56-83%). CONCLUSIONS: The current study indicates that TKI + PD-1 + LRT, especially lenvatinib + PD-1 + LRT, may be the superior conversion therapy with a manageable safety profile for patients with initially unresectable HCC. The successful conversion therapy favors the superior OS and PFS compared with systemic treatment alone. TRIAL REGISTRATION: International prospective register of systematic reviews (PROSPERO) (registration code: CRD 42024495289).

Real-world clinical outcomes of tixagevimab/cilgavimab in the Omicron outbreak in China: baseline characteristics and interim analysis of the CLEAR study.

PURPOSE: This study aimed to investigate the real-world use and clinical outcomes of tixagevimab/cilgavimab in China during the Omicron outbreak in late 2022. METHODS: This observational, real-world study included patients who received tixagevimab/cilgavimab from July 9 to December 30, 2022, in Hainan, China. Here, we report the baseline and characteristics and interim analysis results of the clinical outcomes in those receiving at least one dose of tixagevimab/cilgavimab (300 mg) for pre-exposure prophylaxis. RESULTS: Among 248 subjects who received tixagevimab/cilgavimab, 229 subjects were included in this analysis. Until March 28, 2023, the median follow-up was 95 days. The mean age of the subjects was 44.4 ± 15.9 years, 11.8% were ≥ 65 years, and 41.5% were male. Fifty-eight (25.3%) subjects had comorbidities, 16.2% subjects had key immune compromised conditions. Seventy-two (32.6%) patients had laboratory-confirmed SARS-CoV-2 infection and/or received healthcare within three months; 71/72 (98.6%) had mild disease, and one (1.4%) was moderate. No COVID-19-related intensive care unit (ICU) admissions, extracorporeal membrane oxygenation utilizations, or death occurred. Two (0.9%) patients required hospitalization. One (0.4%) serious adverse event occurred, which was considered unrelated to tixagevimab/cilgavimab. CONCLUSION: Among Chinese patients receiving prophylactic tixagevimab/cilgavimab, the incidence of COVID-19-related hospitalization, ICU admission, or death was low during the Omicron surge. Further randomized controlled trials with larger sample sizes are needed to determine the effectiveness of tixagevimab/cilgavimab in preventing severe COVID-19 outcomes. TRIAL REGISTRATION: The study was registered with clinicaltrial.gov (NCT05917951).

The Role of Endoscopic Ultrasound-guided Fine-needle Aspiration of Pelvic Lesions: A Meta-analysis.

BACKGROUND AND AIMS: Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is a potentially valuable tool for the diagnosis of pelvic lesions. The aim of this meta­analysis was to evaluate the efficacy and feasibility of EUS-FNA in the diagnosis of pelvic lesions. METHODS: We performed a computerized search of PubMed, EMBASE, Cochrane Library, and Science Citation Index, through March 2023. The main outcome measures examined in the meta-analysis were sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy. RESULTS: We evaluated 22 trials that used surgical pathology or imaging follow-up results as the reference standard. The studies comprised 844 patients. The cumulative sensitivity, specificity, PPV, NPV, and accuracy were 94%, 100%, 100%, 89%, and 96%, respectively. In the subgroup analysis, the prospective studies revealed the cumulative sensitivity, specificity, PPV, NPV, and accuracy were 91%, 100%, 100%, 85%, and 93%, respectively. CONCLUSIONS: In conclusion, we provide evidence that EUS-FNA is a qualitative diagnostic technique with high sensitivity, specificity, PPV, and accuracy. However, its NPV is slightly low, which does not exclude the risk of a missed diagnosis, and more randomized controlled trials or prospective studies are still needed in the future. EUS-FNA is effective and feasible for pelvic space-occupying lesions. This technique has high clinical application value for pelvic lesions.

Improving cardiovascular risk prediction with machine learning: a focus on perivascular adipose tissue characteristics.

BACKGROUND: Timely prevention of major adverse cardiovascular events (MACEs) is imperative for reducing cardiovascular diseases-related mortality. Perivascular adipose tissue (PVAT), the adipose tissue surrounding coronary arteries, has attracted increased amounts of attention. Developing a model for predicting the incidence of MACE utilizing machine learning (ML) integrating clinical and PVAT features may facilitate targeted preventive interventions and improve patient outcomes. METHODS: From January 2017 to December 2019, we analyzed a cohort of 1077 individuals who underwent coronary CT scanning at our facility. Clinical features were collected alongside imaging features, such as coronary artery calcium (CAC) scores and perivascular adipose tissue (PVAT) characteristics. Logistic regression (LR), Framingham Risk Score, and ML algorithms were employed for MACE prediction. RESULTS: We screened seven critical features to improve the practicability of the model. MACE patients tended to be older, smokers, and hypertensive. Imaging biomarkers such as CAC scores and PVAT characteristics differed significantly between patients with and without a 3-year MACE risk in a population that did not exhibit disparities in laboratory results. The ensemble model, which leverages multiple ML algorithms, demonstrated superior predictive performance compared with the other models. Finally, the ensemble model was used for risk stratification prediction to explore its clinical application value. CONCLUSIONS: The developed ensemble model effectively predicted MACE incidence based on clinical and imaging features, highlighting the potential of ML algorithms in cardiovascular risk prediction and personalized medicine. Early identification of high-risk patients may facilitate targeted preventive interventions and improve patient outcomes.

Impact of metabolic dysfunction-associated fatty liver disease on the outcomes following laparoscopic hepatectomy for hepatocellular carcinoma.

BACKGROUND: The impact of metabolic dysfunction-associated fatty liver disease (MAFLD) on laparoscopic liver resection (LLR) for hepatocellular carcinoma (HCC) remains unclear. This study aimed to compare the outcomes of LLR for MAFLD-HCC and Non-MAFLD-HCC. METHODS: Patients with HCC who received LLR between October 2017 and July 2021 were enrolled. Inverse probability of treatment weighting (IPTW) was used to generate adjusted comparisons. Both short- and long-term outcomes were evaluated accordingly. RESULTS: A total of 887 patients were enrolled, with 140 in MAFLD group and 747 in Non-MAFLD group. After IPTW adjustment, baseline factors were well matched. The MAFLD group was associated with more blood loss (210 vs 150 ml, p = 0.022), but with similar postoperative hospital stays and complication rates. The 1- and 3-year overall survival rates were 97.4% and 92.5% in MAFLD group, and 97.5% and 88.3% in Non-MAFLD group, respectively (p = 0.14). The 1- and 3-year disease-free survival rates were 84.8% and 62.9% in MAFLD group, and 80.2% and 58.8% in Non-MAFLD group, respectively (p = 0.31). CONCLUSIONS: LLR for MAFLD-HCC was associated with more blood loss but with comparable postoperative recovery and long-term survival compared with Non-MAFLD-HCC patients. LLR is feasible and safe for HCC patients with MAFLD background.

Laparoscopic liver resection or enucleation for giant hepatic hemangioma: how to choose?

BACKGROUND: Laparoscopic treatment has been increasingly adopted for giant hepatic hemangioma (HH), but the role of liver resection or enucleation remains uncertain. The aim of this study is to compare the laparoscopic resection (LR) with laparoscopic enucleation (LE) for HH, and to provide evidence on how to choose the most suitable approach for HH. METHODS: A retrospective analysis of HH patients underwent laparoscopic treatment between March 2015 and August 2022 was performed. Perioperative outcomes were compared based on the surgical approaches, and risk factors for increased blood loss was calculated by logistic regression analysis. RESULTS: A total of 127 patients in LR group and 287 patients in LE group were enrolled in this study. The median blood loss (300 vs. 200 mL, P < 0.001) was higher in LE group than that in LR group. Independent risk factors for blood loss higher than 400 mL were tumor size ≥ 10 cm, tumor adjacent to major vessels, tumor occupying right liver or caudate lobe, and the portal phase enhancement ratio (PER) ≥ 38.9%, respectively. Subgroup analysis showed that LR was associated with less blood loss (155 vs. 400 mL, P < 0.001) than LE procedure in patients with high PER value. Both LR and LE approaches exhibited similar perioperative outcomes in patients with low PER value. CONCLUSIONS: Laparoscopic treatment for HH could be feasibly and safely performed by both LE and LR. For patients with PER higher than 38.9%, the LR approach is recommended.

Interleukin-22 Alleviates Caerulein-Induced Acute Pancreatitis by Activating AKT/mTOR Pathway.

BACKGROUND: Acute pancreatitis (AP) is one of the most common acute abdominal disorders; due to the lack of specific treatment, the treatment of acute pancreatitis, especially serious acute pancreatitis (SAP), is difficult and challenging. We will observe the changes of Interleukin -22 levels in acute pancreatitis animal models, and explore the mechanism of Interleukin -22 in acute pancreatitis. OBJECTIVE: This study aims to assess the potential protective effect of Interleukin -22 on caerulein-induced acute pancreatitis and to explore its mechanism. METHODS: Blood levels of amylase and lipase and Interleukin -22 were assessed in mice with acute pancreatitis. In animal model and cell model of caerulein-induced acute pancreatitis, the mRNA levels of P62 and Beclin-1 were determined using PCR, and the protein expression of P62, LC3-II, mTOR, AKT, p-mTOR, and p-AKT were evaluated through Western blot analysis. RESULTS: Interleukin -22 administration reduced blood amylase and lipase levels and mitigated tissue damage in acute pancreatitis mice model. Interleukin -22 inhibited the relative mRNA levels of P62 and Beclin-1, and the Interleukin -22 group showed a decreased protein expression of LC3-II and P62 and the phosphorylation of the AKT/mTOR pathway. Furthermore, we obtained similar results in the cell model of acute pancreatitis. CONCLUSION: This study suggests that Interleukin -22 administration could alleviate pancreatic damage in caerulein-induced acute pancreatitis. This effect may result from the activation of the AKT/mTOR pathway, leading to the inhibition of autophagy. Consequently, Interleukin -22 shows potential as a treatment.

Calcium signaling regulates the accumulation of phenolic acids in response to UV-B stress in Rhododendron chrysanthum Pall.

KEY MESSAGE: This study, using multi-omics combined with physiologic assays, found that calcium-ion signaling can regulate phenolic acid accumulation in R. chrysanthum leaves in response to UV-B stress. UV-B stress is a severe abiotic stress capable of destroying cellular structures and affecting plant growth. Rhododendron chrysanthum Pall. (R. chrysanthum) is a plant that has been exposed to high levels of UV-B radiation for an extended period, leading to the development of adaptive responses to mitigate UV-B stress. As such, it serves as a valuable experimental material for studying plant resilience to UV-B stress. We utilized R. chrysanthum as the experimental material and subjected it to UV-B stress. We conducted a comprehensive analysis of the changes in R. chrysanthum under both control and UV-B stress conditions using multi-omic and physiologic assays. Our aim was to investigate the molecular mechanism underlying R. chrysanthum's resistance to UV-B stress, with a focus on calcium-ion signaling. UV-B stress was found to impact the photosynthesis of R. chrysanthum by decreasing the maximum photosynthetic efficiency of photosystem II, reducing Fm, and increasing F0. In addition, the composition of numerous phenolic acid compounds was significantly altered. Genes and proteins related to calcium signaling showed significant differences, with some proteins (CML, CPK1, CRK3, ATP2C, ERG3, CAR7) being modified by acetylation. The correlation between genes and proteins involved in calcium signaling and phenolic compounds suggested that calcium signaling may play a role in regulating the accumulation of phenolic compounds under UV-B stress to help R. chrysanthum adapt. This study examines the impact of calcium-ion signaling on the accumulation of phenolic acid compounds, offering insights for future research on the molecular mechanisms underlying plant resilience to UV-B stress.

Multiparameter MRI-based radiomics nomogram for preoperative prediction of brain invasion in atypical meningioma:a multicentre study.

OBJECTIVE: To develop a nomogram based on tumor and peritumoral edema (PE) radiomics features extracted from preoperative multiparameter MRI for predicting brain invasion (BI) in atypical meningioma (AM). METHODS: In this retrospective study, according to the 2021 WHO classification criteria, a total of 469 patients with pathologically confirmed AM from three medical centres were enrolled and divided into training (n = 273), internal validation (n = 117) and external validation (n = 79) cohorts. BI was diagnosed based on the histopathological examination. Preoperative contrast-enhanced T1-weighted MR images (T1C) and T2-weighted MR images (T2) for extracting meningioma features and T2-fluid attenuated inversion recovery (FLAIR) sequences for extracting meningioma and PE features were obtained. The multiple logistic regression was applied to develop separate multiparameter radiomics models for comparison. A nomogram was developed by combining radiomics features and clinical risk factors, and the clinical usefulness of the nomogram was verified using decision curve analysis. RESULTS: Among the clinical factors, PE volume and PE/tumor volume ratio are the risk of BI in AM. The combined nomogram based on multiparameter MRI radiomics features of meningioma and PE and clinical indicators achieved the best performance in predicting BI in AM, with area under the curve values of 0.862 (95% CI, 0.819-0.905) in the training cohort, 0.834 (95% CI, 0.780-0.908) in the internal validation cohort and 0.867 (95% CI, 0.785-0.950) in the external validation cohort, respectively. CONCLUSIONS: The nomogram based on tumor and PE radiomics features extracted from preoperative multiparameter MRI and clinical factors can predict the risk of BI in patients with AM.

Acetylation proteomics and metabolomics analyses reveal the involvement of starch synthase undergoing acetylation modification during UV-B stress resistance in Rhododendron Chrysanthum Pall.

BACKGROUND: Rhododendron chrysanthum Pall. (R. chrysanthum) is a plant that lives in high mountain with strong UV-B radiation, so R. chrysanthum possess resistance to UV-B radiation. The process of stress resistance in plants is closely related to metabolism. Lysine acetylation is an important post-translational modification, and this modification process is involved in a variety of biological processes, and affected the expression of enzymes in metabolic processes. However, little is known about acetylation proteomics during UV-B stress resistance in R. chrysanthum. RESULTS: In this study, R. chrysanthum OJIP curves indicated that UV-B stress damaged the receptor side of the PSII reaction center, with a decrease in photosynthesis, a decrease in sucrose content and an increase in starch content. A total of 807 differentially expressed proteins, 685 differentially acetylated proteins and 945 acetylation sites were identified by quantitative proteomic and acetylation modification histological analysis. According to COG and subcellular location analyses, DEPs with post-translational modification of proteins and carbohydrate metabolism had important roles in resistance to UV-B stress and DEPs were concentrated in chloroplasts. KEGG analyses showed that DEPs were enriched in starch and sucrose metabolic pathways. Analysis of acetylation modification histology showed that the enzymes in the starch and sucrose metabolic pathways underwent acetylation modification and the modification levels were up-regulated. Further analysis showed that only GBSS and SSGBSS changed to DEPs after undergoing acetylation modification. Metabolomics analyses showed that the metabolite content of starch and sucrose metabolism in R. chrysanthum under UV-B stress. CONCLUSIONS: Decreased photosynthesis in R. chrysanthum under UV-B stress, which in turn affects starch and sucrose metabolism. In starch synthesis, GBSS undergoes acetylation modification and the level is upregulated, promotes starch synthesis, making R. chrysanthum resistant to UV-B stress.

Molecular Mechanism of Exogenous ABA to Enhance UV-B Resistance in Rhododendron chrysanthum Pall. by Modulating Flavonoid Accumulation.

With the depletion of the ozone layer, the intensity of ultraviolet B (UV-B) radiation reaching the Earth's surface increases, which in turn causes significant stress to plants and affects all aspects of plant growth and development. The aim of this study was to investigate the mechanism of response to UV-B radiation in the endemic species of Rhododendron chrysanthum Pall. (R. chrysanthum) in the Changbai Mountains and to study how exogenous ABA regulates the response of R. chrysanthum to UV-B stress. The results of chlorophyll fluorescence images and OJIP kinetic curves showed that UV-B radiation damaged the PSII photosystem of R. chrysanthum, and exogenous ABA could alleviate this damage to some extent. A total of 2148 metabolites were detected by metabolomics, of which flavonoids accounted for the highest number (487, or 22.67%). KEGG enrichment analysis of flavonoids that showed differential accumulation by UV-B radiation and exogenous ABA revealed that flavonoid biosynthesis and flavone and flavonol biosynthesis were significantly altered. GO analysis showed that most of the DEGs produced after UV-B radiation and exogenous ABA were distributed in the cellular process, cellular anatomical entity, and catalytic activity. Network analysis of key DFs and DEGs associated with flavonoid synthesis identified key flavonoids (isorhamnetin-3-O-gallate and dihydromyricetin) and genes (TRINITY_DN2213_c0_g1_i4-A1) that promote the resistance of R. chrysanthum to UV-B stress. In addition, multiple transcription factor families were found to be involved in the regulation of the flavonoid synthesis pathway under UV-B stress. Overall, R. chrysanthum actively responded to UV-B stress by regulating changes in flavonoids, especially flavones and flavonols, while exogenous ABA further enhanced its resistance to UV-B stress. The experimental results not only provide a new perspective for understanding the molecular mechanism of the response to UV-B stress in the R. chrysanthum, but also provide a valuable theoretical basis for future research and application in improving plant adversity tolerance.

Abscisic Acid Affects Phenolic Acid Content to Increase Tolerance to UV-B Stress in Rhododendron chrysanthum Pall.

The presence of the ozone hole increases the amount of UV radiation reaching a plant's surface, and UV-B radiation is an abiotic stress capable of affecting plant growth. Rhododendron chrysanthum Pall. (R. chrysanthum) grows in alpine regions, where strong UV-B radiation is present, and has been able to adapt to strong UV-B radiation over a long period of evolution. We investigated the response of R. chrysanthum leaves to UV-B radiation using widely targeted metabolomics and transcriptomics. Although phytohormones have been studied for many years in plant growth and development and adaptation to environmental stresses, this paper is innovative in terms of the species studied and the methods used. Using unique species and the latest research methods, this paper was able to add information to this topic for the species R. chrysanthum. We treated R. chrysanthum grown in a simulated alpine environment, with group M receiving no UV-B radiation and groups N and Q (externally applied abscisic acid treatment) receiving UV-B radiation for 2 days (8 h per day). The results of the MN group showed significant changes in phenolic acid accumulation and differential expression of genes related to phenolic acid synthesis in leaves of R. chrysanthum after UV-B radiation. We combined transcriptomics and metabolomics data to map the metabolic regulatory network of phenolic acids under UV-B stress in order to investigate the response of such secondary metabolites to stress. L-phenylalanine, L-tyrosine and phenylpyruvic acid contents in R. chrysanthum were significantly increased after UV-B radiation. Simultaneously, the levels of 3-hydroxyphenylacetic acid, 2-phenylethanol, anthranilate, 2-hydroxycinnamic acid, 3-hydroxycinnamic acid, α-hydroxycinnamic acid and 2-hydroxy-3-phenylpropanoic acid in this pathway were elevated in response to UV-B stress. In contrast, the study in the NQ group found that externally applied abscisic acid (ABA) in R. chrysanthum had greater tolerance to UV-B radiation, and phenolic acid accumulation under the influence of ABA also showed greater differences. The contents of 2-phenylethanol, 1-o-p-coumaroyl-ß-d-glucose, 2-hydroxy-3-phenylpropanoic acid, 3-(4-hydroxyphenyl)-propionic acid and 3-o-feruloylquinic ac-id-o-glucoside were significantly elevated in R. chrysanthum after external application of ABA to protect against UV-B stress. Taken together, these studies of the three groups indicated that ABA can influence phenolic acid production to promote the response of R. chrysanthum to UV-B stress, which provided a theoretical reference for the study of its complex molecular regulatory mechanism.

RcTRP5 Transcription Factor Mediates the Molecular Mechanism of Lignin Biosynthesis Regulation in R. chrysanthum against UV-B Stress.

UV-B stress destroys the photosynthetic system of Rhododendron chrysanthum Pall. (R. chrysanthum), as manifested by the decrease of photosynthetic efficiency and membrane fluidity, and also promotes the accumulation of lignin. The MYB (v-myb avian myeloblastosis viral oncogene homolog) family of transcription factors can be involved in the response to UV-B stress through the regulation of lignin biosynthesis. This study indicated that both the donor and recipient sides of the R. chrysanthum were significantly damaged based on physiological index measurements made using OJIP curves under UV-B stress. The analysis of bioinformatics data revealed that the RcTRP5 transcription factor exhibits upregulation of acetylation at the K68 site, directly regulating the biosynthesis of lignin. Additionally, there was upregulation of the K43 site and downregulation of the K83 site of the CAD enzyme, as well as upregulation of the K391 site of the PAL enzyme. Based on these findings, we conjectured that the RcTRP5 transcription factor facilitates acetylation modification of both enzymes, thereby indirectly influencing the biosynthesis of lignin. This study demonstrated that lignin accumulation can alleviate the damage caused by UV-B stress to R. chrysanthum, which provides relevant ideas for improving lignin content in plants, and also provides a reference for the study of the metabolic regulation mechanism of other secondary substances.

Single-cell RNA reveals a tumorigenic microenvironment in the interface zone of human breast tumors.

BACKGROUND: The interface zone, area around invasive carcinoma, can be thought of as the actual tissue of the tumor microenvironment with precedent alterations for tumor invasion. However, the heterogeneity and characteristics of the microenvironment in the interface area have not yet been thoroughly explored. METHODS: For in vitro studies, single-cell RNA sequencing (scRNA-seq) was used to characterize the cells from the tumor zone, the normal zone and the interface zone with 5-mm-wide belts between the tumor invasion front and the normal zone. Through scRNA-seq data analysis, we compared the cell types and their transcriptional characteristics in the different zones. Pseudotime, cell-cell communication and pathway analysis were performed to characterize the zone-specific microenvironment. Cell proliferation, wound healing and clone formation experiments explored the function of differentially expressed gene BMPR1B, which were confirmed by tumor models in vivo. RESULTS: After screening, 88,548 high-quality cells were obtained and identified. Regulatory T cells, M2 macrophages, angiogenesis-related mast cells, stem cells with weak DNA repair ability, endothelial cells with angiogenic activity, fibroblasts with collagen synthesis and epithelial cells with proliferative activity form a unique tumorigenic microenvironment in the interface zone. Cell-cell communication analysis revealed that there are special ligand-receptor pairs between different cell types in the interface zone, which protects endothelial cell apoptosis and promotes epithelial cell proliferation and migration, compared to the normal zone. Compared with the normal zone, the highly expressed BMPR1B gene promotes the tumorigenic ability of cancer cells in the interface zone. CONCLUSIONS: Our work identified a unique tumorigenic microenvironment of the interface zone and allowed for deeper insights into the tumor microenvironment of breast cancer that will serve as a helpful resource for advancing breast cancer diagnosis and therapy.