B(C6F5)3/CPA-Catalyzed Aza-Diels-Alder Reaction of 3,3-Difluoro-2-Aryl-3H-indoles and Unactivated Dienes.

Here we report B(C6F5)3/CPA-catalyzed enantioselective aza-Diels-Alder reaction of 3,3-difluoro-2-Aryl-3H-indoles with unactivated dienes to access chiral 10,10-difluoro-tetrahydropyrido[1,2-a]indoles. This protocol allows the formation of pyrazole-based C2-quaternary indolin-3-ones with high enantioselectivities and regioselectivities. Moreover, gram-scale synthesis of the 10,10-difluoro-tetrahydropyrido[1,2-a]indole skeleton was successfully achieved without any reduction in both yield and enantioselectivity.

Longitudinal multi-omics analysis uncovers the altered landscape of gut microbiota and plasma metabolome in response to high altitude.

BACKGROUND: Gut microbiota is significantly influenced by altitude. However, the dynamics of gut microbiota in relation to altitude remains undisclosed. METHODS: In this study, we investigated the microbiome profile of 610 healthy young men from three different places in China, grouped by altitude, duration of residence, and ethnicity. We conducted widely targeted metabolomic profiling and clinical testing to explore metabolic characteristics. RESULTS: Our findings revealed that as the Han individuals migrated from low altitude to high latitude, the gut microbiota gradually converged towards that of the Tibetan populations but reversed upon returning to lower altitude. Across different cohorts, we identified 51 species specifically enriched during acclimatization and 57 species enriched during deacclimatization to high altitude. Notably, Prevotella copri was found to be the most enriched taxon in both Tibetan and Han populations after ascending to high altitude. Furthermore, significant variations in host plasma metabolome and clinical indices at high altitude could be largely explained by changes in gut microbiota composition. Similar to Tibetans, 41 plasma metabolites, such as lactic acid, sphingosine-1-phosphate, taurine, and inositol, were significantly elevated in Han populations after ascending to high altitude. Germ-free animal experiments demonstrated that certain species, such as Escherichia coli and Klebsiella pneumoniae, which exhibited altitude-dependent variations in human populations, might play crucial roles in host purine metabolism. CONCLUSIONS: This study provides insights into the dynamics of gut microbiota and host plasma metabolome with respect to altitude changes, indicating that their dynamics may have implications for host health at high altitude and contribute to host adaptation. Video Abstract.

Experimental validation and comprehensive analysis of m6A methylation regulators in intervertebral disc degeneration subpopulation classification.

Intervertebral disc degeneration (IVDD) is one of the most prevalent causes of chronic low back pain. The role of m6A methylation modification in disc degeneration (IVDD) remains unclear. We investigated immune-related m6A methylation regulators as IVDD biomarkers through comprehensive analysis and experimental validation of m6A methylation regulators in disc degeneration. The training dataset was downloaded from the GEO database and analysed for differentially expressed m6A methylation regulators and immunological features, the differentially regulators were subsequently validated by a rat IVDD model and RT-qPCR. Further screening of key m6A methylation regulators based on machine learning and LASSO regression analysis. Thereafter, a predictive model based on key m6A methylation regulators was constructed for training sets, which was validated by validation set. IVDD patients were then clustered based on the expression of key m6A regulators, and the expression of key m6A regulators and immune infiltrates between clusters was investigated to determine immune markers in IVDD. Finally, we investigated the potential role of the immune marker in IVDD through enrichment analysis, protein-to-protein network analysis, and molecular prediction. By analysising of the training set, we revealed significant differences in gene expression of five methylation regulators including RBM15, YTHDC1, YTHDF3, HNRNPA2B1 and ALKBH5, while finding characteristic immune infiltration of differentially expressed genes, the result was validated by PCR. We then screen the differential m6A regulators in the training set and identified RBM15 and YTHDC1 as key m6A regulators. We then used RBM15 and YTHDC1 to construct a predictive model for IVDD and successfully validated it in the training set. Next, we clustered IVDD patients based on the expression of RBM15 and YTHDC1 and explored the immune infiltration characteristics between clusters as well as the expression of RBM15 and YTHDC1 in the clusters. YTHDC1 was finally identified as an immune biomarker for IVDD. We finally found that YTHDC1 may influence the immune microenvironment of IVDD through ABL1 and TXK. In summary, our results suggest that YTHDC1 is a potential biomarker for the development of IVDD and may provide new insights for the precise prevention and treatment of IVDD.

Electrochemical-induced solvent-tuned selective C(sp3)-H bond activation towards the synthesis of C3-functionalized chromone derivatives.

An unprecedented solvent-tuned electrochemical method for selective C(sp3)-H bond activation towards the synthesis of C3 functionalized chromone derivatives has been developed. This electrosynthesis protocol provides an efficient and green way to access various C3-functionalized chromones by avoiding traditionally employed transition metals and high temperatures. The swappable chemoselectivity was controlled mainly by altering the solvent and the current. A plausible reaction mechanism has been proposed with the help of radical capture and cyclic voltammetry experiments.

TolDC Restores the Balance of Th17/Treg via Aryl Hydrocarbon Receptor to Attenuate Colitis.

BACKGROUND: Tolerogenic dendritic cells (TolDCs) have been evidenced to trigger regulatory T cell's (Treg's) differentiation and be involved in the pathogenesis of Crohn's disease (CD). Aryl hydrocarbon receptor (AhR) plays a crucial role in the differentiation of TolDCs, although the mechanism remains vague. This study aimed to evaluate the role of AhR in TolDCs formation, which may affect Th17/Treg balance in CD. METHODS: Colon biopsy specimens were obtained from healthy controls and patients with CD. Wild type (WT) and AhR-/- mice were induced colitis by drinking dextran sulphate sodium (DSS) with or without 6-formylindolo 3,2-b carbazole (FICZ) treatment. Wild type and AhR-/- bone marrow-derived cells (BMDCs) were cultured under TolDCs polarization condition. Ratios of DCs surface markers were determined by flow cytometry. Enzyme-linked immunosorbent assay (ELISA) was performed to quantify the levels of interleukin (IL)-1ß, transforming growth factor (TGF)-ß and IL-10. Tolerogenic dendritic cells differentiated from BMDCs of WT or AhR-/- mice were adoptively transferred to DSS-induced WT colitis mice. RESULTS: Patients with CD showed less AhR expression and activation in their inflamed colon regions. Compared with WT mice, AhR-/- mice experienced more severe colitis. Tolerogenic dendritic cells and Tregs were both decreased in the colon of AhR-/- colitis mice, while Th17 cells were upregulated. In vitro, compared with WT DCs, AhR-deficient DCs led to less TolDC formation. Furthermore, intestinal inflammation in WT colitis mice, which transferred with AhR-/- TolDCs, showed no obvious improvement compared with those transferred with WT TolDCs, as evidenced by no rescues of Th17/Treg balance. CONCLUSIONS: Activation of AhR attenuates experimental colitis by modulating the balance of TolDCs and Th17/Treg. The AhR modulation of TolDCs may be a viable therapeutic approach for CD.

Deletion of AhR aggravated colitis in mice, while AhR activation ameliorated colitis by promoting TolDCs formation which in turn restored Th17/Treg balance in colons. Thus, induction of TolDCs via regulating AhR may supply a therapeutic target for CD.

Neoadjuvant chemoradiotherapy combined with sequential perioperative toripalimab in locally advanced esophageal squamous cell cancer.

BACKGROUND: Programmed death 1 (PD-1) inhibitor demonstrated durable antitumor activity in advanced esophageal squamous cell carcinoma (ESCC), but the clinical benefit of perioperative immunotherapy in ESCC remains unclear. This study evaluated the efficacy and safety of neoadjuvant chemoradiotherapy (nCRT) combined with the PD-1 inhibitor toripalimab in patients with resectable ESCC. METHODS: From July 2020 to July 2022, 21 patients with histopathologically confirmed thoracic ESCC and clinical staged as cT1-4aN1-2M0/cT3-4aN0M0 were enrolled. Eligible patients received radiotherapy (23 fractions of 1.8 Gy, 5 fractions a week) with concurrent chemotherapy of paclitaxel/cisplatin (paclitaxel 45 mg/m2 and cisplatin 25 mg/m2) on days 1, 8, 15, 22, 29 and two cycles of toripalimab 240 mg every 3 weeks after nCRT for neoadjuvant therapy before surgery, four cycles of toripalimab 240 mg every 3 weeks for adjuvant therapy after surgery. The primary endpoint was the major pathological response (MPR) rate. The secondary endpoints were safety and survival outcomes. RESULTS: A total of 21 patients were included, of whom 20 patients underwent surgery, 1 patient refused surgery and another patient was confirmed adenocarcinoma after surgery. The MPR and pathological complete response (pCR) rates were 78.9% (15/19) and 47.4% (9/19) for surgery ESCC patients. 21 patients (100.0%) had any-grade treatment-related adverse events, with the most common being lymphopenia (100.0%), leukopenia (85.7%), neutropenia (52.4%). 14 patients (66.7%) had adverse events of grade 3 with the most common being lymphopenia (66.7%). The maximum standardized uptake value and total lesion glycolysis of positron emission tomography/CT after neoadjuvant therapy well predicted the pathological response. The peripheral CD4+%, CD3+HLA-DR+/CD3+%, CD8+HLA-DR+/CD8+%, and IL-6 were significant differences between pCR and non-pCR groups at different times during neoadjuvant therapy. Three patients had tumor relapse and patients with MPR have longer disease-free survival than non-MPR patients. CONCLUSIONS: nCRT combined with perioperative toripalimab is effective and safe for locally advanced resectable ESCC. Long-term survival outcomes remain to be determined. TRIAL REGISTRATION NUMBER: NCT04437212.

Electrochemical multicomponent [2+2+1] cascade cyclization of enaminones and primary amines towards the synthesis of 4-acylimidazoles.

An electrochemical multicomponent [2+2+1] cascade cyclization of enaminones and primary amines towards the synthesis of 4-acylimidazoles has been developed. In an undivided cell, enaminones and primary amines can smoothly participate in this reaction to provide a series of 1,2-disubstituted 4-acylimidazoles at room temperature. The reaction avoids the use of both transition-metal catalysts and oxidation reagents, which makes it more sustainable and renewable.

Impact of army morale on suicidal ideation: The mediating role of grit and the moderating role of social support in a Chinese Navy population.

This study constructed a moderated mediation model to examine whether increased army morale could reduce suicidal ideation. The mediating role of grit and the moderating role of social support were also examined. A total of 1029 male navy cadets in China were recruited to complete the survey. The measures used in the study included the Army Morale Scale, Grit Scale, Social Support Scale, and Self-rated Idea of Suicide Scale. The results indicated that: increased army morale could significantly reduce suicidal ideation; the impact of army morale on suicidal ideation could be partially mediated by grit; and social support moderated the impact of army morale on suicidal ideation. Specifically, relatively higher levels of social support could reduce suicidal ideation among individuals with lower levels of army morale, but the effect is not significant when the morale is at a high level. The study revealed that increased army morale could reduce suicidal ideation. Moreover, the mediating role of grit and the moderating role of social support were also revealed.

Asymmetric Organocatalyzed Cyclization Cascade Reactions of 3,3-Difluoro-2-aryl-3H-indoles and Enamides.

The direct functionalization of ß-C(sp2)-H bonds in enamides has garnered increasing attention within the realm of organic synthesis. However, these remarkable advancements are predominantly dependent on transition metals; limited success has been achieved via organocatalytic catalysis. Herein, we report a CPA-catalyzed ß-C(sp2)-H functionalization of enamides cascade intramolecular cyclization to synthesize the chiral dihydropyrimido[1,6-a]indoles bearing gem-difluoromethylene. Moreover, this methodology enables the synthesis of diverse chiral dihydropyrimido[1,6-a]indoles with outstanding enantioselectivities in moderate to high yields.

Electrochemical-Induced C-N Bond Formation: A New Method to Synthesis (Z)-Quinazolinone Oximes Using Primary Amines and Quinazolin-4(3H)-one.

A novel and highly selective electrochemical method for the synthesis of diverse quinazolinone oximes via direct electrooxidation of primary amines/C(sp2)-H functionalization of oximes has been developed. The reaction is conducted in an undivided cell under constant current conditions and is oxidant-free, open-air, and eco-friendly. Notably, the protocol shows good functional group tolerance, providing versatile quinazolinone oximes in good yields. Moreover, the mechanism is investigated through control experiments and cyclic voltammogram (CV) experiments.

In-situ registration subtraction image segmentation algorithm for spatiotemporal visualization of copper adsorption onto corn stalk-derived pellet biochar by micro-computed tomography.

The non-homogeneous structure and high-density ash composition of biochar matrix pose significant challenges in characterizing the dynamic changes of heavy metal adsorption onto biochar with micro-computed tomography (Micro-CT). A novel in-situ registration subtraction image segmentation method (IRS) was developed to enhance micro-CT characterization accuracy. The kinetics of Cu(II) adsorption onto pellet biochar derived from corn stalks were tested. Respectively, the IRS and traditional K-means algorithms were used for image segmentation to the in-situ three-dimensional (3D) visual characterization of the Cu(II) adsorption onto biochar. The results indicated that the IRS algorithm reduced interference from high-density biochar composition, and thus achieved more precise results (R2 = 0.95) than that of K-means (R2 = 0.72). The visualized dynamic migration of Cu(II) from surface adsorption to intraparticle diffusion reflexed the complex mechanism of heavy metal adsorption. The developed Micro-CT method with high generalizability has great potential for studying the process and mechanism of biochar heavy metal adsorption.

High-Level Biosynthesis of Chlorogenic Acid from Mixed Carbon Sources of Xylose and Glucose through a Rationally Refactored Pathway Network.

Chlorogenic acid (CGA) has incredible potential for various pharmaceutical, nutraceutical, and agricultural applications. However, the traditional extraction approach from plants is time-consuming, further limiting its production. Herein, we design and construct the de novo biosynthesis pathway of CGA using modular coculture engineering in Escherichia coli, which is composed of MG09 and BD07 strains. To accomplish this, the phenylalanine-deficient MG09 strain was engineered to utilize xylose preferentially and to overproduce precursor caffeic acid, while the tyrosine-deficient BD07 strain was constructed to consume glucose exclusively to enhance another precursor quinic acid availability for the biosynthesis of CGA. Further pathway modularization and balancing in the context of syntrophic cocultures resulted in additional production improvement. The coculture strategy avoids metabolic flux competition in the biosynthesis of two CGA precursors, caffeic acid and quinic acid, and allows for production improvement by balancing module proportions. Finally, the optimized coculture based on the aforementioned efforts produced 131.31 ± 7.89 mg/L CGA. Overall, the modular coculture engineering strategy in this study provides a reference for constructing microbial cell factories that can efficiently biomanufacture complex natural products.

KIF2C: An important factor involved in signaling pathways, immune infiltration, and DNA damage repair in tumorigenesis.

BACKGROUNDS: Poorly regulated mitosis and chromosomal instability are common characteristics in malignant tumor cells. Kinesin family member 2 C (KIF2C), also known as mitotic centromere-associated kinesin (MCAK) is an essential component during mitotic regulation. In recent years, KIF2C was shown to be dysregulated in several tumors and was involved in many aspects of tumor self-regulation. Research on KIF2C may be a new direction and target for anti-tumor therapy. OBJECT: The article aims at reviewing current literatures and summarizing the research status of KIF2C in malignant tumors as well as the oncogenic signaling pathways associated with KIF2C and its role in immune infiltration. RESULT: In this review, we summarize the KIF2C mechanisms and signaling pathways in different malignant tumors, and briefly describe its involvement in pathways related to classical chemotherapeutic drug resistance, such as MEK/ERK, mTOR, Wnt/ß-catenin, P53 and TGF-ß1/Smad pathways. KIF2C upregulation was shown to promote tumor cell migration, invasion, chemotherapy resistance and inhibit DNA damage repair. It was also highly correlated with microRNAs, and CD4 +T cell and CD8 +T cell tumor immune infiltration. CONCLUSION: This review shows that KIF2C may function as a new anticancer drug target with great potential for malignant tumor treatment and the mitigation of chemotherapy resistance.

Multi-omics reveals changed energy metabolism of liver and muscle by caffeine after mice swimming.

In recent years, numerous studies have investigated the effects of caffeine on exercise, and provide convincing evidence for its ergogenic effects on exercise performance. However, the precise mechanisms underlying these ergogenic effects remain unclear. In this study, an exercise swimming model was conducted to investigate the effects of orally administered with caffeine before swimming on the alterations of proteome and energy metabolome of liver and muscle after swimming. We found proteins in liver, such as S100a8, S100a9, Gabpa, Igfbp1 and Sdc4, were significantly up-regulated, while Rbp4 and Tf decreased after swimming were further down-regulated in caffeine group. The glycolysis and pentose phosphate pathways in liver and muscle were both significantly down-regulated in caffeine group. The pyruvate carboxylase and amino acid levels in liver, including cysteine, serine and tyrosine, were markedly up-regulated in caffeine group, exhibiting a strong correlation with the increased pyruvic acid and oxaloacetate levels in muscle. Moreover, caffeine significantly decreased the lactate levels in both liver and muscle after swimming, potentially benefiting exercise performance.

Structural and functional changes in the brain after chronic complete thoracic spinal cord injury.

This study aimed to investigate whether brain anatomical structures and functional network connectivity are altered after chronic complete thoracic spinal cord injury (cctSCI) and to determine how these changes impact clinical outcomes. Structural and resting-state functional MRI was performed for 19 cctSCI patients (18 for final statistics) and 19 healthy controls. Voxel-based morphometry (VBM) was used to assess gray matter volume (GMV) with differences between cctSCI patients and controls. VBM results were used as seeds for whole-brain functional connectivity (FC) analysis. The relationship between brain changes and clinical variables was investigated. Compared with those of the control group, the left triangular inferior frontal gyrus, middle frontal gyrus, orbital inferior frontal gyrus, precuneus and parietal superior gyrus volumes of SCI patients decreased, while the left superior frontal gyrus and supplementary motor area volumes increased. Additionally, when the regions with increased GMV were used as seeds, the FC of the parahippocampus and thalamus increased. Subsequent partial correlation analysis showed a positive correlation between FC and total sensorimotor score based on the ASIA criteria (p = 0.001, r = 0.746). Overall, the structural and functional changes in the brain after cctSCI occurred in some visual and cognitive areas and sensory or motor control areas. These findings aid in improving our understanding of the underlying brain injury mechanisms and the subsequent structural and functional reorganization to reveal potential therapeutic targets and track treatment outcomes.

Identification of an association between coronary heart disease and ITGB2 methylation in peripheral blood by a case-control study.

BACKGROUND: Blood DNA methylation was associated with coronary heart disease (CHD) risk in Caucasians. We investigated the association between DNA methylation in peripheral blood at the reported loci and CHD in the Chinese population. METHODS: The integrin subunit beta 2 (ITGB2) gene was identified in 196 CHD cases and 184 controls, and its methylation level was determined by mass spectrometry. Logistic regression was used to assess the association. RESULTS: Hypomethylation of ITGB2 was significantly associated with heart failure CHD and NYHA Ⅰ&Ⅱ CHD patients with minor to medium cardiac function impairment (ITGB2_CpG_11/cg08422803, OR per -10 % methylation = 1.15 and 1.16; p = 0.012 and 0.018 by Bonferroni correction, respectively). Hypomethylation of ITGB2_CpG_11/cg08422803 was a risk factor for CHD in people < 65 years and males (p < 0.05 after Bonferroni correction). The combination of ITGB2 methylation and conventional CHD risk factors could efficiently discriminate CHD, heart failure CHD, NYHA I&II CHD, and myocardial infarction CHD patients from controls (AUC = 0.78, 0.81, 0.80, and 0.81, respectively). CONCLUSION: Blood-based ITGB2 methylation has the potential as a biomarker for CHD. The combination of ITGB2 methylation and conventional CHD risk factors may improve the risk assessment and detection of CHD.

Exceptional piezocatalytic H2 production of nitrogen-doped TiO2@carbon nanosheets induced by engineered piezoelectricity.

Piezocatalytic hydrogen evolution is a promising strategy to generate sustainable energy. In this report, nitrogen-doped (N-doped) TiO2@ carbon nanosheets (N-TiO2@C NSs) was successfully synthesized using C3N4 as a multifunctional template. During the synthesis, the two-dimensional (2D) architecture of C3N4 nanosheets directed the synthesis of TiO2 nanosheets. In addition, nitrogens of C3N4 were doped into the TiO2 lattice. Simultaneously, C3N4 was transformed into N-doped carbon nanosheets. N doping broke the crystal symmetry of TiO2, which endowed TiO2 with promising piezoelectric properties. The N-doped carbon nanosheets derived from C3N4 improved charge carrier separation efficiency and served as a flexible support to inhibit structural damage under sonication. Therefore, the N-TiO2@C NSs exhibited highly efficient activity for piezocatalytic H2 production (6.4 mmol·g-1·h-1) in the presence of methanol, much higher than those of the previously reported piezocatalysts. Our method is hoped to provide a new strategy for designing highly efficient piezocatalysts.

Integrated multi-omics profiling to dissect the spatiotemporal evolution of metastatic hepatocellular carcinoma.

Comprehensive molecular analyses of metastatic hepatocellular carcinoma (HCC) are lacking. Here, we generate multi-omic profiling of 257 primary and 176 metastatic regions from 182 HCC patients. Primary tumors rich in hypoxia signatures facilitated polyclonal dissemination. Genomic divergence between primary and metastatic HCC is high, and early dissemination is prevalent. The remarkable neoantigen intratumor heterogeneity observed in metastases is associated with decreased T cell reactivity, resulting from disruptions to neoantigen presentation. We identify somatic copy number alterations as highly selected events driving metastasis. Subclones without Wnt mutations show a stronger selective advantage for metastasis than those with Wnt mutations and are characterized by a microenvironment rich in activated fibroblasts favoring a pro-metastatic phenotype. Finally, metastases without Wnt mutations exhibit higher enrichment of immunosuppressive B cells that mediate terminal exhaustion of CD8+ T cells via HLA-E:CD94-NKG2A checkpoint axis. Collectively, our results provide a multi-dimensional dissection of the complex evolutionary process of metastasis.

Structural variants involved in high-altitude adaptation detected using single-molecule long-read sequencing.

Structural variants (SVs), accounting for a larger fraction of the genome than SNPs/InDels, are an important pool of genetic variation, enabling environmental adaptations. Here, we perform long-read sequencing data of 320 Tibetan and Han samples and show that SVs are highly involved in high-altitude adaptation. We expand the landscape of global SVs, apply robust models of selection and population differentiation combining SVs, SNPs and InDels, and use epigenomic analyses to predict enhancers, target genes and biological functions. We reveal diverse Tibetan-specific SVs affecting the regulatory circuitry of biological functions, including the hypoxia response, energy metabolism and pulmonary function. We find a Tibetan-specific deletion disrupts a super-enhancer and downregulates EPAS1 using enhancer reporter, cellular knock-out and DNA pull-down assays. Our study expands the global SV landscape, reveals the role of gene-regulatory circuitry rewiring in human adaptation, and illustrates the diverse functional roles of SVs in human biology.

Highly Enantioselective Synthesis of 3a-Fluorofuro[3,2-b]indolines via Organocatalytic Aza-Friedel-Crafts Reaction/Selective C-F Bond Activation.

Fluoroalkylated compounds are of high interest in drug discovery and have inspired the evolution of diverse C-F bond activation methodologies. However, the selective activation of polyfluorinated compounds remains challenging. Herein, we describe an unprecedented strategy for synthesizing enantioenriched fluorofuro[3,2-b]indolines through the organocatalytic aza-Friedel-Crafts reaction coupled with selective C-F bond activation. These reactions feature excellent enantioselectivities (≤96% ee) and yields (≤96%) as well as good functional group compatibility. Mechanistic investigations by means of 19F nuclear magnetic resonance experiments provided sufficient support for silica gel as the key medium in this transformation.