Reducing acetylated tau is neuroprotective in brain injury.

Traumatic brain injury (TBI) is the largest non-genetic, non-aging related risk factor for Alzheimer's disease (AD). We report here that TBI induces tau acetylation (ac-tau) at sites acetylated also in human AD brain. This is mediated by S-nitrosylated-GAPDH, which simultaneously inactivates Sirtuin1 deacetylase and activates p300/CBP acetyltransferase, increasing neuronal ac-tau. Subsequent tau mislocalization causes neurodegeneration and neurobehavioral impairment, and ac-tau accumulates in the blood. Blocking GAPDH S-nitrosylation, inhibiting p300/CBP, or stimulating Sirtuin1 all protect mice from neurodegeneration, neurobehavioral impairment, and blood and brain accumulation of ac-tau after TBI. Ac-tau is thus a therapeutic target and potential blood biomarker of TBI that may represent pathologic convergence between TBI and AD. Increased ac-tau in human AD brain is further augmented in AD patients with history of TBI, and patients receiving the p300/CBP inhibitors salsalate or diflunisal exhibit decreased incidence of AD and clinically diagnosed TBI.

Multimodal single-cell/nucleus RNA sequencing data analysis uncovers molecular networks between disease-associated microglia and astrocytes with implications for drug repurposing in Alzheimer's disease.

Because disease-associated microglia (DAM) and disease-associated astrocytes (DAA) are involved in the pathophysiology of Alzheimer's disease (AD), we systematically identified molecular networks between DAM and DAA to uncover novel therapeutic targets for AD. Specifically, we develop a network-based methodology that leverages single-cell/nucleus RNA sequencing data from both transgenic mouse models and AD patient brains, as well as drug-target network, metabolite-enzyme associations, the human protein-protein interactome, and large-scale longitudinal patient data. Through this approach, we find both common and unique gene network regulators between DAM (i.e., PAK1, MAPK14, and CSF1R) and DAA (i.e., NFKB1, FOS, and JUN) that are significantly enriched by neuro-inflammatory pathways and well-known genetic variants (i.e., BIN1). We identify shared immune pathways between DAM and DAA, including Th17 cell differentiation and chemokine signaling. Last, integrative metabolite-enzyme network analyses suggest that fatty acids and amino acids may trigger molecular alterations in DAM and DAA. Combining network-based prediction and retrospective case-control observations with 7.2 million individuals, we identify that usage of fluticasone (an approved glucocorticoid receptor agonist) is significantly associated with a reduced incidence of AD (hazard ratio [HR] = 0.86, 95% confidence interval [CI] 0.83-0.89, P < 1.0 × 10-8). Propensity score-stratified cohort studies reveal that usage of mometasone (a stronger glucocorticoid receptor agonist) is significantly associated with a decreased risk of AD (HR = 0.74, 95% CI 0.68-0.81, P < 1.0 × 10-8) compared to fluticasone after adjusting age, gender, and disease comorbidities. In summary, we present a network-based, multimodal methodology for single-cell/nucleus genomics-informed drug discovery and have identified fluticasone and mometasone as potential treatments in AD.

Versatile Synthesis of Symmetric and Unsymmetric Imines via Photoelectrochemical Catalysis: Application to N-Terminal Modification of Phenylalanine.

A strategy that combines electrochemical synthesis and photoredox catalysis was reported for the efficient synthesis of imines. This approach was demonstrated to be highly versatile in producing various types of imines, including symmetric and unsymmetric imines, by exploring the impact of different substituents on the benzene ring of the arylamine. Additionally, the method was specifically applied to modify N-terminal phenylalanine residues and was found to be successful in the photoelectrochemical cross-coupling reaction between NH2 -Phe-OMe and aryl methylamines, leading to the synthesis of phenylalanine-containing imines. Therefore, this technique would present a convenient and efficient platform for synthesizing imines, with promising applications in chemical biology, drug development, and organic synthesis.

A pharmacovigilance study of pharmacokinetic drug interactions using a translational informatics discovery approach.

BACKGROUND: While the pharmacokinetic (PK) mechanisms for many drug interactions (DDIs) have been established, pharmacovigilance studies related to these PK DDIs are limited. Using a large surveillance database, a translational informatics approach can systematically screen adverse drug events (ADEs) for many DDIs with known PK mechanisms. METHODS: We collected a set of substrates and inhibitors related to the cytochrome P450 (CYP) isoforms, as recommended by the United States Food and Drug Administration (FDA) and Drug Interactions Flockhart table™. The FDA's Adverse Events Reporting System (FAERS) was used to obtain ADE reports from 2004 to 2018. The substrate and inhibitor information were used to form PK DDI pairs for each of the CYP isoforms and Medical Dictionary for Regulatory Activities (MedDRA) preferred terms used for ADEs in FAERS. A shrinkage observed-to-expected ratio (Ω) analysis was performed to screen for potential PK DDI and ADE associations. RESULTS: We identified 149 CYP substrates and 62 CYP inhibitors from the FDA and Flockhart tables. Using FAERS data, only those DDI-ADE associations were considered that met the disproportionality threshold of Ω > 0 for a CYP substrate when paired with at least two inhibitors. In total, 590 ADEs were associated with 2085 PK DDI pairs and 38 individual substrates, with ADEs overlapping across different CYP substrates. More importantly, we were able to find clinical and experimental evidence for the paclitaxel-clopidogrel interaction associated with peripheral neuropathy in our study. CONCLUSION: In this study, we utilized a translational informatics approach to discover potentially novel CYP-related substrate-inhibitor and ADE associations using FAERS. Future clinical, population-based and experimental studies are needed to confirm our findings.

Comparative assessment of manual chart review and ICD claims data in evaluating immunotherapy-related adverse events.

BACKGROUND: The aim of this retrospective study was to demonstrate that irAEs, specifically gastrointestinal and pulmonary, examined through International Classification of Disease (ICD) data leads to underrepresentation of true irAEs and overrepresentation of false irAEs, thereby concluding that ICD claims data are a poor approach to electronic health record (EHR) data mining for irAEs in immunotherapy clinical research. METHODS: This retrospective analysis was conducted in 1,063 cancer patients who received ICIs between 2011 and 2017. We identified irAEs by manual review of medical records to determine the incidence of each of our endpoints, namely colitis, hepatitis, pneumonitis, other irAE, or no irAE. We then performed a secondary analysis utilizing ICD claims data alone using a broad range of symptom and disease-specific ICD codes representative of irAEs. RESULTS: 16% (n = 174/1,063) of the total study population was initially found to have either pneumonitis 3% (n = 37), colitis 7% (n = 81) or hepatitis 5% (n = 56) on manual review. Of these patients, 46% (n = 80/174) did not have ICD code evidence in the EHR reflecting their irAE. Of the total patients not found to have any irAEs during manual review, 61% (n = 459/748) of patients had ICD codes suggestive of possible irAE, yet were not identified as having an irAE during manual review. DISCUSSION: Examining gastrointestinal and pulmonary irAEs through the International Classification of Disease (ICD) data leads to underrepresentation of true irAEs and overrepresentation of false irAEs.

Electrooxidation Enables Selective Dehydrogenative [4+2] Annulation between Indole Derivatives.

Dearomative annulation of indoles has emerged as a powerful tool for the preparation of polycyclic indoline-based alkaloids. Compared with well-established methods towards five-membered-ring-fused indolines, the six-membered-ring-fused indolines are rarely accessed under thermal conditions. Herein, a dearomative [4+2] annulation between different indoles is developed through an electrochemical pathway. This transformation offers a remarkably regio- and stereoselective route to highly functionalized pyrimido[5,4-b]indoles under oxidant- and metal-free conditions. Notably, this electrochemical approach maintains excellent functional-group tolerance and can be extended as a modification tactic for pharmaceutical research. Preliminary mechanism studies indicate that the electrooxidation annulation proceeds through radical-radical cross-coupling between an indole radical cation and an N-centered radical generated in situ.

XANES/EPR Evidence of the Oxidation of Nickel(II) Quinolinylpropioamide and Its Application in Csp3 -H Functionalization.

An in situ generated oxidation species of nickel quinolinylpropioamide intermediate was produced. Characterization by X-ray absorption near edge structure (XANES) and EPR provides complementary insights into this oxidized nickel species. With aliphatic amides and isocyanides as substrates, a nickel-catalyzed facile synthesis of structurally diverse five-membered lactams could be achieved.

Microbiota and gastrointestinal cancer.

Gut microbiota plays important roles in many diseases, including cancer. It may promote carcinogenesis by inducing oxidative stress, genotoxicity, host immune response disturbance, and chronic inflammation. Colorectal cancer, hepatocellular carcinoma, and gastric cancer are the major gastrointestinal tract cancers in Taiwan. The microbiota detected in patients with tubular adenoma and villous/tubulovillous polyps is different from that in healthy controls and patients with hyperplastic polyps. Normalization of the microbiota is observed in patients after colorectal cancer treatment. Furthermore, the liver is exposed to microbiota-associated molecular patterns (MAMPs), bacterial metabolites, and toxins, as it is anatomically connected to the gut via the portal vein. Patients with cirrhosis have significantly higher plasma endotoxin levels than healthy controls. Helicobacter pylori is a well-established risk factor for gastric cancer. Some nitrosating bacteria convert nitrogen compounds in gastric fluid to potentially carcinogenic N-nitroso compounds, which also contribute to gastric cancer development. Growing evidence demonstrates that gut microbiota promotes carcinogenesis. In this review, we discuss the mechanisms and types of microbiota changes involved in these gastrointestinal cancers and the future treatment choices.

Visible-Light-Induced [4+2] Annulation of Thiophenes and Alkynes to Construct Benzene Rings.

The [4+2] annulation represents an elegant and versatile synthetic protocol for the construction of benzene rings. Herein, a strategy for visible-light induced [4+2] annulation of thiophenes and alkynes, to afford benzene rings, is presented. Under simple and mild reaction conditions, the ready availability and structural diversity of thiophenes and alkynes permit the facile synthesis of several substituted aromatic rings. Valuable drugs and amino acids are also well tolerated. Moreover, DFT calculations explain the high regioselectivity of the reaction.

Mixture drug-count response model for the high-dimensional drug combinatory effect on myopathy.

Drug-drug interactions (DDIs) are a common cause of adverse drug events (ADEs). The electronic medical record (EMR) database and the FDA's adverse event reporting system (FAERS) database are the major data sources for mining and testing the ADE associated DDI signals. Most DDI data mining methods focus on pair-wise drug interactions, and methods to detect high-dimensional DDIs in medical databases are lacking. In this paper, we propose 2 novel mixture drug-count response models for detecting high-dimensional drug combinations that induce myopathy. The "count" indicates the number of drugs in a combination. One model is called fixed probability mixture drug-count response model with a maximum risk threshold (FMDRM-MRT). The other model is called count-dependent probability mixture drug-count response model with a maximum risk threshold (CMDRM-MRT), in which the mixture probability is count dependent. Compared with the previous mixture drug-count response model (MDRM) developed by our group, these 2 new models show a better likelihood in detecting high-dimensional drug combinatory effects on myopathy. CMDRM-MRT identified and validated (54; 374; 637; 442; 131) 2-way to 6-way drug interactions, respectively, which induce myopathy in both EMR and FAERS databases. We further demonstrate FAERS data capture much higher maximum myopathy risk than EMR data do. The consistency of 2 mixture models' parameters and local false discovery rate estimates are evaluated through statistical simulation studies.

External Oxidant-Free Dehydrogenative Lactonization of 2-Arylbenzoic Acids via Visible-Light Photocatalysis.

An external oxidant-free C-H functionalization/C-O bond formation reaction for constructing benzo-3,4-coumarins accompanied by quantitative H2 evolution has been developed. High functional group tolerance and excellent reaction efficiency are shown in this transformation. Meanwhile, the substrates containing heterocyclic substituents such as thienyl-, pyridinyl-, and pyrrolylbenzoic acids displayed good performance. Importantly, this reaction can be performed with good efficiency on a gram scale. A cyclic voltammetry study and density functional theory calculations could provide insight into the mechanism of this reaction.

Furans Accessed through Visible-Light-Mediated Oxidative [3+2] Cycloaddition of Enols and Alkynes.

Visible-light-mediated formation of furans though direct oxidative [3+2] cycloaddition of 1,3-diones and alkynes is described. This protocol provides a simple and mild route to poly-substituted furans in moderate-to-good yields. Preliminary mechanistic studies suggest that this reaction likely follows a radical addition/cyclization pathway.

From Anilines to Quinolines: Iodide- and Silver-Mediated Aerobic Double C-H Oxidative Annulation-Aromatization.

Quinoline synthesis from easily accessible raw materials such as anilines is a valuable and meaningful task. Herein, we communicate an iodide- and silver-mediated C-H/C-H oxidative annulation-aromatization between anilines and allyl alcohols. This protocol provides a direct route to the synthesis of quinoline derivatives from inexpensive commodities. Various kinds of anilines, even heterocyclic anilines, were shown to be workable substrates, generating the corresponding multi-substituted quinolines in good yields.

Markovnikov-Selective Radical Addition of S-Nucleophiles to Terminal Alkynes through a Photoredox Process.

Direct radical additions to terminal alkynes have been widely employed in organic synthesis, providing credible access to the anti-Markovnikov products. Because of the Kharasch effect, regioselective control for the formation of Markovnikov products still remains a great challenge. Herein, we develop a transition-metal-free, visible light-mediated radical addition of S-nucleophiles to terminal alkynes, furnishing a wide array of α-substituted vinyl sulfones with exclusive Markovnikov regioselectivity. Mechanistic investigations demonstrated that radical/radical cross-coupling might be the key step in this transformation. This radical Markovnikov addition protocol also provides an opportunity to facilitate the synthesis of other valuable α-substituted vinyl compounds.

Anti-Markovnikov Oxidation of ß-Alkyl Styrenes with H2O as the Terminal Oxidant.

Oxygenation of alkenes is one of the most straightforward routes for the construction of carbonyl compounds. Wacker oxidation provides a broadly useful strategy to convert the mineral oil into higher value-added carbonyl chemicals. However, the conventional Wacker chemistry remains problematic, such as the poor activity for internal alkenes, the lack of anti-Markovnikov regioselectivity, and the high cost and chemical waste resulted from noble metal catalysts and stoichiometric oxidant. Here, we describe an unprecedented dehydrogenative oxygenation of ß-alkyl styrenes and their derivatives with water under external-oxidant-free conditions by utilizing the synergistic effect of photocatalysis and proton-reduction catalysis that can address these challenges. This dual catalytic system possesses the single anti-Markovnikov selectivity due to the property of the visible-light-induced alkene radical cation intermediate.

Catalyst-Free Difunctionalization of Activated Alkenes in Water: Efficient Synthesis of ß-Keto Sulfides and Sulfones.

Difunctionalization of activated alkenes, a powerful strategy in chemical synthesis, has been accomplished for direct synthesis of a series of ß-keto sulfides and ß-keto sulfones. The transformation, mediated by O2 , proceeds smoothly in water and without any catalyst. Prominent advantages of this method include mild reaction conditions, purification simplicity, and gram-scale synthesis, underlining the practical utility of this methodology.

Spectroscopic and Theoretical Study of Spin-Dependent Electron Transfer in an Iron(III) Superoxo Complex.

It was shown previously (J. Am. Chem. Soc. 2014, 136, 10846) that bubbling of O2 into a solution of Fe(II)(BDPP) (H2BDPP = 2,6-bis[[(S)-2-(diphenylhydroxymethyl)-1-pyrrolidinyl]methyl]pyridine) in tetrahydrofuran at -80 °C generates a high-spin (SFe = (5)/2) iron(III) superoxo adduct, 1. Mössbauer studies revealed that 1 is an exchange-coupled system, [Formula: see text], where SR = (1)/2 is the spin of the superoxo radical, of which the spectra were not well enough resolved to determine whether the coupling was ferromagnetic (S = 3 ground state) or antiferromagnetic (S = 2). The glass-forming 2-methyltetrahydrofuran solvent yields highly resolved Mössbauer spectra from which the following data have been extracted: (i) the ground state of 1 has S = 3 (J < 0); (ii) |J| > 15 cm(-1); (iii) the zero-field-splitting parameters are D = -1.1 cm(-1) and E/D = 0.02; (iv) the major component of the electric-field-gradient tensor is tilted ≈7° relative to the easy axis of magnetization determined by the MS = ±3 and ±2 doublets. The excited-state MS = ±2 doublet yields a narrow parallel-mode electron paramagnetic resonance signal at g = 8.03, which was used to probe the magnetic hyperfine splitting of (17)O-enriched O2. A theoretical model that considers spin-dependent electron transfer for the cases where the doubly occupied π* orbital of the superoxo ligand is either "in" or "out" of the plane defined by the bent Fe-OO moiety correctly predicts that 1 has an S = 3 ground state, in contrast to the density functional theory calculations for 1, which give a ground state with both the wrong spin and orbital configuration. This failure has been traced to a basis set superposition error in the interactions between the superoxo moiety and the adjacent five-membered rings of the BDPP ligand and signals a fundamental problem in the quantum chemistry of O2 activation.

Characterization of a paramagnetic mononuclear nonheme iron-superoxo complex.

O2 bubbling into a THF solution of Fe(II)(BDPP) (1) at -80 °C generates a reversible bright yellow adduct 2. Characterization by resonance Raman and Mössbauer spectroscopy provides complementary insights into the nature of 2. The former shows a resonance-enhanced vibration at 1125 cm(-1), which can be assigned to the ν(O-O) of a bound superoxide, while the latter reveals the presence of a high-spin iron(III) center that is exchange-coupled to the superoxo ligand, like the Fe(III)-O2(-) pair found for the O2 adduct of 4-nitrocatechol-bound homoprotocatechuate 2,3-dioxygenase. Lastly, 2 oxidizes dihydroanthracene to anthracene, supporting the notion that Fe(III)-O2(-) species can carry out H atom abstraction from a C-H bond to initiate the 4-electron oxidation of substrates proposed for some nonheme iron enzymes.

Synthesis and characterization of Ni(III)N3S2 complexes as active site models for the oxidized form of nickel superoxide dismutase.

Nickel complexes, [Ni(H2BA(R)TPP)](ClO4)2 (R = Ph for 1 or iPr for 2), supported by a pentadentate ligand H2BA(R)TPP were synthesized and oxidized to form Ni(III) species having a N3S2 coordination environment to mimic the active site of the oxidized form of nickel superoxide dismutase (NiSODox). The Ni(III) species 2(+) exhibited a rhombic signal with g values at 2.15, 2.12 and 2.02 similar to that of NiSODox. DFT calculations revealed that 2(+) has an unpaired electron primarily located in the dz2 orbital of the Ni(III) center, which strongly overlaps with the pz orbital of the axial pyridine nitrogen of H2BA(Pr)TPP.

Advancements in Understanding and Preventing Obesity-Related Colon Cancer.

ABSTRACT: Obesity and colorectal cancer are global public health issues, with the prevalence of both conditions increasing over the last 4 decades. In the United States alone, the prevalence of obesity is greater than 40%, and this percentage is projected to increase past 50% by 2030. This review focuses on understanding the association between obesity and the risk of colorectal cancer while also highlighting hypotheses about molecular mechanisms underlying the link between these disease processes. We also consider whether those linkages can be disrupted via weight loss therapies, including lifestyle modifications, pharmacotherapy, bariatric surgery, and endobariatrics.