"Fix and Click" for Assay of Sphingolipid Signaling in Single Primary Human Intestinal Epithelial Cells.

Capillary electrophoresis with fluorescence detection (CE-F) is a powerful method to measure enzyme activation in single cells. However, cellular enzymatic assays used in CE-F routinely utilize reporter substrates that possess a bulky fluorophore that may impact enzyme kinetics. To address these challenges, we describe a "fix and click" method utilizing an alkyne-terminated enzyme activation reporter, aldehyde-based fixation, and a click chemistry reaction to attach a fluorophore prior to analysis by single-cell CE-F. The "fix and click" strategy was utilized to investigate sphingolipid signaling in both immortalized cell lines and primary human colonic epithelial cells. When the sphingosine alkyne reporter was loaded into cells, this reporter was metabolized to ceramide (31.6 ± 3.3% peak area) without the production of sphingosine-1-phosphate. In contrast, when the reporter sphingosine fluorescein was introduced into cells, sphingosine fluorescein was converted to sphingosine-1-phosphate and downstream products (32.8 ± 5.7% peak area) without the formation of ceramide. Sphingolipid metabolism was measured in single cells from both differentiated and stem/proliferative human colonic epithelium using "fix and click" paired with CE-F to highlight the diversity of sphingosine metabolism in single cells from primary human colonic epithelium. This novel method will find widespread utility for the performance of single-cell enzyme assays by virtue of its ability to temporally and spatially separate cellular reactions with alkyne-terminated reporters, followed by the assay of enzyme activation at a later time and place.

Asymmetric Total Synthesis of Hetidine-Type C20-Diterpenoid Alkaloids: (+)-Talassimidine and (+)-Talassamine.

Here, we report the first asymmetric total synthesis of (+)-talassimidine and (+)-talassamine, two hetidine-type C20-diterpenoid alkaloids. A highly regio- and diastereoselective 1,3-dipolar cycloaddition of an azomethine ylide yielded a chiral tetracyclic intermediate in high enantiopurity, thus providing the structural basis for asymmetric assembly of the hexacyclic hetidine skeleton. In this key step, the introduction of a single chiral center induces four new continuous chiral centers. Another key transformation is the dearomative cyclopropanation of the benzene ring and subsequent SN2-like ring opening of the resultant cyclopropane ring with water as a nucleophile, which not only establishes the B ring but also precisely installs the difficult-to-achieve equatorial C7-OH group.

Neighboring Hydroxyl Group-Assisted Allylboration and Lewis Acid-Mediated Carbonyl-Ene Reaction for Access to a Hapalindole Cyclohexane Core with Multiple Contiguous Stereogenic Centers.

A neighboring hydroxyl group-assisted allylboration of 3-indolyl ketones with γ,γ-disubstituted allylboronic acids is reported, affording various 3-indolyl-substituted homoallylic alcohols in good yields with excellent diastereoselectivies (up to >20:1 dr). The hydroxyl group not only played a vital role in the challenging allylboration but was elaborated for the subsequent construction of a hapalindole cyclohexane core by a highly diastereoselective Lewis acid-catalyzed carbonyl-ene reaction. In the overall process, four contiguous stereogenic centers including two quaternary stereogenic centers were installed.

Stereoselective Total Synthesis of Hetisine-type C20 -Diterpenoid Alkaloids: Spirasine IV and XI.

The first total synthesis of the architecturally complex hetisine-type heptacyclic C20 -diterpenoid alkaloids (±)-spirasine IV and XI is reported. The A/F/G/C tetracyclic skeleton with the challenging N-C6 and C14-C20 linkages was efficiently constructed by an intramolecular azomethine-ylide-based 1,3-dipolar cycloaddition with unusual regioselectivity. SmI2 -mediated free-radical addition to the arene moiety without prior dearomatization and a stereoselective intramolecular aldol reaction further enabled rapid access to the hetisine core, providing a bicyclo[2.2.2]octane ring with a new oxygen substitution pattern.

Predictive significance of glycolysis-associated lncRNA profiles in colorectal cancer progression.

BACKGROUND: The Warburg effect is a hallmark characteristic of colorectal cancer (CRC). Despite extensive research, the role of long non-coding RNAs (lncRNAs) in influencing the Warburg effect remains incompletely understood. Our study aims to identify lncRNAs that may modulate the Warburg effect by functioning as competing endogenous RNAs (ceRNAs). METHODS: Utilizing bioinformatics approaches, we extracted glycolysis-associated gene data from the Kyoto Encyclopedia of Genes and Genomes (KEGG) and identified 101 glycolysis-related lncRNAs in CRC. We employed Univariable Cox regression, Least Absolute Shrinkage and Selection Operator (LASSO) regression analysis, and Multivariable Cox regression to develop a prognostic model comprising four glycolysis-linked lncRNAs. We then constructed a prognostic nomogram integrating this lncRNA model with other relevant clinical parameters. RESULTS: The prognostic efficacy of our four-lncRNA signature and its associated nomogram was validated in both training and validation cohorts. Functional assays demonstrated significant glycolysis and hexokinase II (HK2) inhibition following the silencing of RUNDC3A - AS1, a key lncRNA in our prognostic signature, highlighting its regulatory importance in the Warburg effect. CONCLUSIONS: Our research illuminates the critical role of glycolysis-centric lncRNAs in CRC. The developed prognostic model and nomogram underscore the pivotal prognostic and regulatory significance of the lncRNA RUNDC3A - AS1 in the Warburg effect in colorectal cancer.

Discovery of D8-03 as an Inhibitor of Intracellular Growth of Francisella tularensis.

Francisella tularensis is a Gram-negative facultative intracellular bacterial pathogen that is classified by the Centers for Disease Control and Prevention as a Tier 1 Select Agent. F. tularensis infection causes the disease tularemia, also known as rabbit fever. Treatment of tularemia is limited to few effective antibiotics which are associated with high relapse rates, toxicity, and potential emergence of antibiotic-resistant strains. Consequently, new therapeutic options for tularemia are needed. Through screening a focused chemical library and subsequent structure-activity relationship studies, we have discovered a new and potent inhibitor of intracellular growth of Francisella tularensis, D8-03. Importantly, D8-03 effectively reduces bacterial burden in mice infected with F. tularensis. Preliminary mechanistic investigations suggest that D8-03 works through a potentially novel host-dependent mechanism and serves as a promising lead compound for further development.

Mendelian randomization supports causality between gut microbiota and chronic hepatitis B.

Background: Observational studies have provided evidence of a close association between gut microbiota and the progression of chronic hepatitis B (CHB). However, establishing a causal relationship between gut microbiota and CHB remains a subject of investigation. Methods: Genome-wide association study (GWAS) summary data of gut microbiota came from the MiBioGen consortium, while the GWAS summary data of CHB came from the Medical Research Council Integrative Epidemiology Unit (IEU) Open GWAS project. Based on the maximum likelihood (ML), Mendelian randomization (MR)-Egger regression, inverse variance weighted (IVW), MR Pleiotropy RESidual Sum and Outlier (MR-PRESSO), and weighted-mode and weighted-median methods, we conducted a bidirectional, two-sample, MR analysis to explore the causal relationship between the gut microbiota and CHB. Additionally, we evaluated the genetic associations between individual gut microbes and CHB using the Linkage disequilibrium score regression (LDSC) program. Results: According to the IVW method estimates, genetically predicted class Alphaproteobacteria (odds ratio [OR] = 0.57; 95% confidence interval [CI], 0.34-0.96; false discovery rate [FDR] = 0.046), genus Family XIII AD3011 group (OR = 0.60; 95% CI, 0.39-0.91; FDR = 0.026), genus Prevotella 7 (OR = 0.73; 95% CI, 0.56-0.94; FDR = 0.022) exhibited a protective effect against CHB. On the other hand, family Family XIII (OR = 1.79; 95% CI, 1.03-3.12; FDR = 0.061), genus Eggerthella group (OR = 1.34; 95% CI, 1.04-1.74; FDR = 0.043), genus Eubacterium ventriosum group (OR = 1.59; 95% CI, 1.01-2.51; FDR = 0.056), genus Holdemania (OR = 1.35; 95% CI, 1.00-1.82; FDR = 0.049), and genus Ruminococcus gauvreauii group (OR = 1.69; 95% CI, 1.10-2.61; FDR = 0.076) were associated with an increased risk of CHB. The results from LDSC also indicated a significant genetic correlation between most of the aforementioned gut microbiota and CHB. Our reverse MR analysis demonstrated no causal relationship between genetically predicted CHB and gut microbiota, and we observed no significant horizontal pleiotropy or heterogeneity of instrumental variables (IVs). Conclusion: In this study, we identified three types of gut microbiota with a protective effect on CHB and five types with an adverse impact on CHB. We postulate that this information will facilitate the clinical prevention and treatment of CHB through fecal microbiota transplantation.

Metabolism-Related Prognostic Biomarkers, Purine Metabolism and Anti-Tumor Immunity in Colon Adenocarcinoma.

BACKGROUND: Metabolic reprogramming provides a new perspective for understanding cancer. The targeting of dysregulated metabolic pathways may help to reprogram the immune status of the tumor microenvironment (TME), thereby increasing the effectiveness of immune checkpoint therapy. Colorectal cancer (CRC), especially colon adenocarcinoma (COAD), is associated with poor patient survival. The aim of the present study was to identify novel pathways involved in the development and prognosis of COAD, and to explore whether these pathways could be used as targets to improve the efficacy of immunotherapy. METHODS: Metabolism-related differentially expressed genes (MRDEGs) between tumor and normal tissues were identified using The Cancer Genome Atlas (TCGA) dataset, together with metabolism-related prognostic genes (MRPGs). Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis was performed separately for the MRDEGs and MRPGs. Gene Set Variation Analysis (GSVA) was also performed to explore the role of purine metabolism in COAD tumorigenesis. Consensus clustering of purine metabolism genes with the overall survival (OS) of patients and with anti-tumor immunity was also performed. Pearson correlation analysis was used to identify potential targets that correlated strongly with the expression of immune checkpoints. RESULTS: A 6-gene signature that had independent prognostic significance for COAD was identified, together with a predictive model for risk stratification and prognosis. The most significantly enriched pathway amongst MRDEGs and MRPGs was purine metabolism. Differentially expressed purine metabolism genes could divide patients into two clusters with distinct prognosis and anti-tumor immunity. Further analysis suggested that purine metabolism was involved in anti-tumor immunity. CONCLUSIONS: This study confirmed the importance of metabolism-related pathways and in particular purine metabolism in the tumorigenesis, prognosis and anti-tumor immunity of COAD. We identified a 6-gene prognostic signature comprised of EPHX2, GPX3, PTGDS, NAT2, ACOX1 and CPT2. In addition, four potential immune-metabolic checkpoints (GUCY1A1, GUCY1B1, PDE1A and PDE5A) were identified, which could be used to improve the efficacy of immunotherapy in COAD.

Bis[2-(3-pyridinio)benzimidazolium] di-mu-chloro-bis[trichlorocadmium(II)].

The title compound, (C12H11N3)2[Cd2Cl8], consists of two discrete 2-(3-pyridinio)benzimidazolium cations and one [Cd2Cl8]4- anion. The dimeric [Cd2Cl8]4- anion lies about an inversion centre and consists of two distorted [CdCl5] trigonal bipyramids which share a common edge. The two Cd atoms are each coordinated by two mu-Cl atoms and three terminal Cl atoms, with a Cd...Cd separation of 3.9853 (6) A. The packing displays two-dimensional hydrogen-bonded sheets, which are further linked by C-H...Cl contacts and pi-pi stacking interactions to yield a three-dimensional network.

catena-Poly[[heptakis(dimethylformamide-kappaO)di-mu4-oxo-tetra-mu3-oxo-hexadeca-mu2-oxo-tetraoxolanthanum(III)octamolybdenum(IV)]-mu-sodium(I)].

The title compound, [NaLaMo(8)O(26)(C(3)H(7)NO)(7)](n), contains infinite chains of [Mo(8)O(26)](4-) units supporting dimethylformamide-coordinated La(III) cations and linked by Na(+) cations. The lanthanum center adopts a nine-coordinate geometry and the Na atom is sandwiched between two beta-[Mo(8)O(26)](4-) units.

catena-Poly[[[mu-pyridinium-3-carboxylato-bis[dioxomolybdenum(VI)]]-di-mu3-oxo] monohydrate].

A novel chain molybdenum compound, [[Mo2O6(C6H5NO2)].H2O]n, which was synthesized under hydrothermal conditions, consists of an infinite rail-like chain formed by molybdenum oxide units linked by zwitterionic nicotinic acid ligands. Each Mo atom is coordinated octahedrally by six O atoms and the MoO6 octahedra are linked to one another via edge-sharing to produce a zigzag polymeric chain, with nicotinic acid ligands located, alternately, on each side of the rail-like chain plane.

Structure and properties of a novel 3D straight-channel polyoxovanadate and an unexpected trimeric barbiturate obtained by hydrothermal reactions.

The hydrothermal reaction of NaVO(3).H(2)O, barbituric acid, NH(2)NH(2).2HCl, H(3)PO(4), and H(2)O gave a novel heteropolyoxovanadate Na(6)[(P(V)O(4))V(V)(6)V(IV)(12)O(39)](2).H(3)PO(4).31H(2)O (1) and an unexpected phase Na(2)[C(12)H(6)N(6)O(9)].7H(2)O (2). The basic building blocks in 1 are the six-capped sphere-shaped heteropoly anion [(P(V)O(4))V(V)(6)V(IV)(12)O(39)](3-) with framework similar to that of the reported polyoxovanadates possessing [V(18)O(42)] clusters encapsulating VO(4) or other ions. These heterpoly anionic units are linked via V[bond]O[bond]V bridges into an interesting 3D straight-channel structure. The structure of 2 consists of novel organic anions ([C(12)H(6)N(6)O(9)](2-), 5,5-bis(2',4',6'-trioxopyrimidyl)barbital, representing the first oxidized barbituric acid trimer) linked via sodium ions into 1D hollow tubes with diameter of 4.49 x 6.86 A and further connected into a three-dimensional framework via hydrogen bonds.