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1.
Org Lett ; 2024 Sep 06.
Article in English | MEDLINE | ID: mdl-39240022

ABSTRACT

The use of an earth-abundant and inexpensive iron complex as a catalyst, coupled with near-infrared (NIR) light as the energy source, for radical reactions with alkyl halides has been far less developed. In this study, we report NIR light-mediated iron(I) dimer-catalyzed radical cascade reactions of fluoroalkyl bromides for the synthesis of ring-fused quinazolinones bearing a difluoromethyl group. In this process, the 3-bromo-1,10-phenanthroline ligand facilitates the reactivity of [CpFe(CO)2]2, thereby improving the efficiency of the reaction.

2.
Mol Divers ; 2024 Aug 14.
Article in English | MEDLINE | ID: mdl-39141208

ABSTRACT

A series of novel sulfonyl hydrazide based ß-carboline derivatives (SX1-SX32) were designed and synthesized, and their structures were characterized on NMR and HRMS. Their α-glucosidase inhibitory screening results found that compounds (SX1-SX32) presented potential α-glucosidase inhibitory: IC50 values being 2.12 ± 0.33-19.37 ± 1.49 µM. Compound SX29 with a para-phenyl (IC50: 2.12 ± 0.33 µM) presented the strongest activity and was confirmed as a noncompetitive inhibitor. Fluorescence spectra, CD spectra and molecular docking were conducted to describe the inhibition mechanism of SX29 against α-glucosidase. Cells cytotoxicity indicated SX29 (0-32 µM) had no cytotoxicity on 293T cells. In particular, in vivo experiments revealed that oral administration of SX29 could regulate hyperglycemia and glucose tolerance of diabetic mice. These achieved findings indicated that sulfonyl hydrazide based ß-carboline derivatives bore promising potential for discovering new α-glucosidase inhibitors with hypoglycemic activity.

3.
Article in English | MEDLINE | ID: mdl-39104322

ABSTRACT

Apoptosis, inflammation, and wound healing are critical pathophysiological events associated with various liver diseases. Currently, there is a lack of in vivo approaches to study hepatocyte apoptosis-induced liver injury and repair. To address this critical knowledge gap, we developed a unique genetically modified mouse model, namely, 3xTg-iHAP (3-Transgene with inducible Hepatocyte Apoptosis Phenotype) in this study. The 3xTg-iHAP mice possess three transgenes including Alb-Cre, Rosa26-rtTA, and tetO-Fasl on a B6 background. These mice are phenotypically normal, viable, and fertile. After subcutaneous administration of a single dose of doxycycline (5 mg/kg, Dox) to 3xTg-iHAP mice, we observed a complete histological spectrum of sterile liver wound-healing responses: asymptomatic hepatocyte apoptosis at 8 h, necrotic liver injury and sterile inflammation at 48 h, followed by hepatocyte mitosis and regeneration within 7 days. During the injury phase, the mice exhibited an increase in biomarkers of ALT, CXCL1, and IL-6 in peripheral blood and α-SMA protein in liver tissues. Conversely, the mice displayed a decrease in these markers in the recovery phase. Remarkably, this model shows that the sterile liver injury following elevated hepatocyte apoptosis is associated with an increase in myeloid cells in the liver. Within 7 days post-Dox administration, the liver of Dox-treated 3xTg-iHAP mice displays a normal histological structure, indicating completion of wound-healing. Together, we established a novel mouse model of injury and regeneration induced by hepatocyte apoptosis. This tool provides a robust in vivo platform for studying the pathophysiology of sterile liver inflammation, regeneration, and new therapeutic interventions for liver diseases.

4.
Front Pharmacol ; 15: 1448381, 2024.
Article in English | MEDLINE | ID: mdl-39185308

ABSTRACT

Background: Artesunate (ART), a natural compound derived from Artemisia annua, has shown promising clinical potentials in the treatment of various tumors, but the exact mechanism is unclear. Choroidal melanoma (CM) is a major malignant ocular tumor in adults, known for its significant malignancy and poor prognosis, with limited efficacy in current treatments. This study explored the anti-CM effects and mechanisms of ART using a combination of network pharmacology, molecular docking and experimental validation. Methods: Potential targets of ART were screened in PubChem, Swiss Target Prediction and Traditional Chinese Medicine Systems Pharmacology (TCMSP) Database Analysis Platform databases, while target genes related to CM prognosis were selected from Online Mendelian Inheritance in Man (OMIM), GeneCards and DisGeNET databases. The intersection of these two groups of datasets yielded the target genes of ART involved in CM. Protein-protein interaction (PPI) network analysis of the intersecting targets, as well as Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses, were conducted to identify core targets and critical pathways. Molecular docking methods were performed to predict the binding interactions between ART and core targets. The effects of ART on CM were evaluated through CCK8, colony formation, transwell, as well as flow cytometry assays to detect apoptosis, cell cycle, reactive oxygen species (ROS). Western blot (WB) assays were conducted to investigate the impact of ART on key proteins and pathways associated with CM. Finally, in vivo assays were conducted to further validate the effects of ART on subcutaneous tumors in nude mice. Results: Research has shown that key pathways and core targets for ART in treating CM were identified through a network pharmacology approach. Molecular docking results verified the strong binding affinity between ART and these core targets. The analysis and predicted results indicated that ART primarily exerted its effects on CM through various tumor-related pathways like apoptosis. The assays in vitro confirmed that ART significantly inhibited the proliferation and migration of CM cells. This was achieved by promoting apoptosis through activation of the p53 signaling pathway, causing cell cycle arrest at the G0/G1 phase by inhibiting the PI3K/AKT/mTOR signaling pathway and increasing the intracellular level of ROS by activating the NRF2/HO-1 signaling pathway. Additionally, the assays in vivo further validated the significant proliferation-inhibitory effect of ART on CM. Conclusion: This study, making the initial exploration, illustrated through network pharmacology combined with molecular docking and in vitro/in vivo assays, confirmed that ART exerted potential anti-cancer effects on CM by promoting apoptosis, inducing cell cycle arrest and increasing intracellular levels of ROS. These findings suggested that ART held significant therapeutic potential for CM.

5.
Front Oncol ; 14: 1441222, 2024.
Article in English | MEDLINE | ID: mdl-39156700

ABSTRACT

Genomic instability stands out as a pivotal hallmark of cancer, and PARP inhibitors (PARPi) emerging as a groundbreaking class of targeted therapy drugs meticulously crafted to inhibit the repair of DNA single-strand breaks(SSB) in tumor cells. Currently, PARPi have been approved for the treatment of ovarian cancer, pancreatic cancer, breast cancer, and prostate cancer characterized by homologous recombination(HR) repair deficiencies due to mutations in BRCA1/2 or other DNA repair associated genes and acquiring the designation of breakthrough therapy. Nonetheless, PARPi exhibit limited efficacy in the majority of HR-proficient BRCA1/2 wild-type cancers. At present, the synergistic approach of combining PARPi with agents that induce HR defects, or with chemotherapy and radiotherapy to induce substantial DNA damage, significantly enhances the efficacy of PARPi in BRCA wild-type or HR-proficient patients, supporting extension the use of PARPi in HR proficient patients. Therefore, we have summarized the effects and mechanisms of the combined use of drugs with PARPi, including the combination of PARPi with HR defect-inducing drugs such as ATRi, CHKi, HR indirectly inducing drugs like VEGFRi, CDKi, immune checkpoint inhibitors and drugs instigating DNA damage such as chemotherapy or radiotherapy. In addition, this review discusses several ongoing clinical trials aimed at analyzing the clinical application potential of these combined treatment strategies.

6.
Nano Lett ; 24(34): 10562-10568, 2024 Aug 28.
Article in English | MEDLINE | ID: mdl-39159397

ABSTRACT

MnBi2Te4 is a magnetic topological insulator with layered A-type antiferromagnetic order. It exhibits a rich layer- and magnetic-state dependent topological phase diagram; however, much about the coupling between spin, charge, and lattice remains to be explored. In this work, we report that MnBi2Te4 is an excellent acoustic phonon cavity by realizing phonon frequency combs using picosecond ultrasonics. With the generated acoustic phonon wavepackets, we demonstrate that the timing and phase of acoustic echoes can be used to detect the presence of stacking faults between van der Waals layers buried deep within the crystal. Furthermore, by implementing this nondestructive ultrafast optical measurement in conjunction with time-resolved magneto-optical Kerr effect experiments, we uncover that out-of-plane vibrations in MnBi2Te4 do not couple to the magnetic order, i.e. there is no appreciable magnetostriction. Our work points out how a well-developed technique can probe the structural defects and phonon pulse engineering in layered topological insulators.

7.
Cell Host Microbe ; 2024 Aug 21.
Article in English | MEDLINE | ID: mdl-39214086

ABSTRACT

The pathogenic outcome of enteric virus infections is governed by a complex interplay between the virus, intestinal microbiota, and host immune factors, with metabolites serving as a key mediator. Noroviruses bind bile acid metabolites, which are produced by the host and then modified by commensal bacteria. Paradoxically, bile acids can have both proviral and antiviral roles during norovirus infections. Working in an infant mouse model of norovirus infection, we demonstrate that microbiota and their bile acid metabolites protect from norovirus diarrhea, whereas host bile acids promote disease. We also find that maternal bile acid metabolism determines the susceptibility of newborn mice to norovirus diarrhea during breastfeeding. Finally, targeting maternal and neonatal bile acid metabolism can protect newborn mice from norovirus disease. In summary, neonatal metabolic immaturity and breastmilk bile acids are central determinants of heightened newborn vulnerability to norovirus disease.

8.
Stem Cell Res Ther ; 15(1): 214, 2024 Jul 18.
Article in English | MEDLINE | ID: mdl-39020385

ABSTRACT

Sciatic nerve injury (SNI) is a common type of peripheral nerve injury typically resulting from trauma, such as contusion, sharp force injuries, drug injections, pelvic fractures, or hip dislocations. It leads to both sensory and motor dysfunctions, characterized by pain, numbness, loss of sensation, muscle atrophy, reduced muscle tone, and limb paralysis. These symptoms can significantly diminish a patient's quality of life. Following SNI, Wallerian degeneration occurs, which activates various signaling pathways, inflammatory factors, and epigenetic regulators. Despite the availability of several surgical and nonsurgical treatments, their effectiveness remains suboptimal. Exosomes are extracellular vesicles with diameters ranging from 30 to 150 nm, originating from the endoplasmic reticulum. They play a crucial role in facilitating intercellular communication and have emerged as highly promising vehicles for drug delivery. Increasing evidence supports the significant potential of exosomes in repairing SNI. This review delves into the pathological progression of SNI, techniques for generating exosomes, the molecular mechanisms behind SNI recovery with exosomes, the effectiveness of combining exosomes with other approaches for SNI repair, and the changes and future outlook for utilizing exosomes in SNI recovery.


Subject(s)
Exosomes , Sciatic Nerve , Exosomes/metabolism , Exosomes/transplantation , Humans , Animals , Sciatic Nerve/injuries , Peripheral Nerve Injuries/therapy , Peripheral Nerve Injuries/metabolism , Nerve Regeneration
9.
Sci Rep ; 14(1): 16394, 2024 Jul 16.
Article in English | MEDLINE | ID: mdl-39014016

ABSTRACT

Solid nitrogen exhibits a panoply of phenomena ranging from complex molecular crystalline configurations to polymerization and closing band gap at higher densities. Among the elemental molecular solids, nitrogen stands apart for having phases, which can only be stabilized following particular pressure-temperature pathways, indicative of metastability and kinetic barriers. Here, through the combination of Raman spectroscopy and dynamic compression techniques, we find that the appearance of the whole nitrogen phase diagram is determined by the P-T paths taken below 2 GPa. We reveal the existence of the path- and phase-dependent triple point between the ß - N 2 , δ loc - N 2 and γ - or ϵ - N 2 . We further show that the ß - N 2 towards γ - N 2 path below the triple point, that evades δ ( δ loc )- N 2 , results in the formation of γ - N 2 , which in turn becomes a dominant phase. We then demonstrate, that the ß - N 2 through δ ( δ loc )- N 2 above the triple point path leads to the formation of ϵ - N 2 and the "well-established" phase diagram. An additional pathway, which by-passes the rotationally inhibited modifications δ ( δ loc )- N 2 , via rapid compression is found to produce γ - N 2 at higher temperatures. We argue that the pathway and phase sensitive triple point and the compression rate dependent phase formation challenge our understanding of this archetypal dense molecular solid.

10.
Acta Histochem ; 126(5-7): 152174, 2024 Jul 07.
Article in English | MEDLINE | ID: mdl-38976933

ABSTRACT

Choroidal melanoma (CM), a highly metastatic eye tumor, exhibits vasculogenic mimicry (VM) facilitated by hypoxia-induced angiogenesis. This study explored the inhibitory impact of the anti-malarial drug Artesunate (ART) on CM VM through modulation of the HIF-1α/VEGF/PDGF pathway. Immunohistochemistry (IHC) confirmed VM in CM with elevated VEGF and PDGF expression. Hypoxia promoted CM proliferation, upregulating HIF-1α, VEGF and PDGF. VEGF and PDGF enhanced CM migration, invasion and VM, with HIF-1α playing a crucial role. ART mitigated VM formation by suppressing the HIF-1α/VEGF/PDGF pathway, highlighting its potential as an anti-tumor agent in CM.

11.
Environ Res ; 259: 119576, 2024 Oct 15.
Article in English | MEDLINE | ID: mdl-38996958

ABSTRACT

The interaction between extracellular polymeric substances (EPS) in municipal sludge and antibiotics in wastewater is critical in wastewater treatment, resource recovery, and sludge management. Therefore, it is increasingly urgent to investigate the distribution coefficient (Log K) of sulfonamide antibiotics (SAs) in EPS, particularly in sludge-derived dissolved organic carbon (DOC) and aqueous phase systems. Herein, through balance experiments, the concentrations of SAs were determined using alkaline extraction EPS (AEPS) and alginate-like extracellular polymer (ALE) systems, and the Log KDOC values were determined. The results showed that the Log KDOC of AEPS was higher than that of ALE, which exhibited a negative KDOC value, indicating an inhibitory effect on dissolution. For the three SAs studied, the Log KDOC values were in the following order: sulfamethoxazole > sulfapyridine > sulfadiazine. This order can be attributed to the differing physicochemical properties, such as polarity, of the SAs. Three-dimensional excitation-emission matrix fluorescence spectra and fitting results indicated a lack of aromatic proteins dominated by tryptophan and humus-like substances in ALE. Meanwhile, the hydrophobic interaction of aromatic proteins dominated by tryptophan was the main driving force in the binding process between AEPS and SAs.


Subject(s)
Anti-Bacterial Agents , Extracellular Polymeric Substance Matrix , Sewage , Sulfonamides , Water Pollutants, Chemical , Sewage/chemistry , Anti-Bacterial Agents/analysis , Anti-Bacterial Agents/chemistry , Sulfonamides/analysis , Sulfonamides/chemistry , Extracellular Polymeric Substance Matrix/chemistry , Water Pollutants, Chemical/analysis , Water Pollutants, Chemical/chemistry , Waste Disposal, Fluid/methods
12.
Org Lett ; 26(31): 6658-6663, 2024 Aug 09.
Article in English | MEDLINE | ID: mdl-39083395

ABSTRACT

The regiocontrol in constructing benzo-fused five-membered rings by C-H cyclization remains an important challenge. We report a highly general and regioselective methodology to access such heterocycles and indenones, where under the catalysis of CoBr2/bipyridine, aryl titanates, alkynes and EX2 (E = NR, S(O), RP(O), R2Si, CO, etc.) were assembled to various heterocycles and indenones in a modular manner. Unprecedented 1,2-Co/Ti heterobimetallic arylene and benzotitanole intermediates have played crucial roles in these syntheses.

13.
Front Pharmacol ; 15: 1380098, 2024.
Article in English | MEDLINE | ID: mdl-38881875

ABSTRACT

Rheumatoid arthritis is a chronic immunological disease leading to the progressive bone and joint destruction. Angiogenesis, accompanied by synovial hyperplasia and inflammation underlies joint destruction. Delaying or even blocking synovial angiogenesis has emerged as an important target of RA treatment. Natural medicines has a long history of treating RA, and numerous reports have suggested that natural medicines have a strong inhibitory activity on synovial angiogenesis, thereby improving the progression of RA. Natural medicines could regulate the following signaling pathways: HIF/VEGF/ANG, PI3K/Akt pathway, MAPKs pathway, NF-κB pathway, PPARγ pathway, JAK2/STAT3 pathway, etc., thereby inhibiting angiogenesis. Tripterygium wilfordii Hook. f. (TwHF), sinomenine, and total glucoside of Paeonia lactiflora Pall. Are currently the most representative of all natural products worthy of development and utilization. In this paper, the main factors affecting angiogenesis were discussed and different types of natural medicines that inhibit angiogenesis were systematically summarized. Their specific anti-angiogenesis mechanisms are also reviewed which aiming to provide new perspective and options for the management of RA by targeting angiogenesis.

14.
Bioresour Technol ; 406: 131044, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38936679

ABSTRACT

The recovery of biopolymers, particularly alginate-like extracellular polymers, from municipal sludge represents a promising step toward sustainable sludge treatment practices. Originating from wastewater plants in complexly polluted environments, alginate-like extracellular polymers carry potential environmental risks concerning their reuse. This study employs ultrahigh-performance liquid chromatography-tandem mass spectrometry to investigate the distribution coefficients and occurrence of alginate-like extracellular polymers and sulfamethoxazole. Results demonstrate a negative distribution coefficient, suggesting an inhibitory effect on sulfamethoxazole dissolution. The ethanol-extracted alginate-like extracellular polymers exhibits higher sulfamethoxazole levels (approximately 52%) than those obtained via dialysis extraction. Three-dimensional excitation-emission matrix analysis and adsorption studies indicate the absence of tyrosine-like substances in the alginate-like extracellular polymers, unlike in other extracellular polymeric substances. This absence diminishes hydrophobic interactions, highlighting that electrostatic interactions play a more important role. These insights are crucial for understanding the adsorption behavior of alginate-like extracellular polymers and optimizing their large-scale extraction processes.


Subject(s)
Alginates , Sewage , Sulfamethoxazole , Alginates/chemistry , Sewage/chemistry , Adsorption , Glucuronic Acid/chemistry , Chromatography, High Pressure Liquid , Extracellular Polymeric Substance Matrix/chemistry , Extracellular Polymeric Substance Matrix/metabolism , Polymers/chemistry , Tandem Mass Spectrometry
15.
Eur J Med Chem ; 275: 116595, 2024 Sep 05.
Article in English | MEDLINE | ID: mdl-38875808

ABSTRACT

In the quest for potent α-glucosidase inhibitors to combat diabetes, a series of novel thiosemicarbazide-based ß-carboline derivatives (CTL1∼36) were synthesized and evaluated. CTL1∼36 exhibited remarkable inhibitory effects against α-glucosidase, with IC50 values ranging from 2.81 to 12.40 µM, significantly surpassing the positive control acarbose (IC50 = 564.28 µM). Notably, CTL26 demonstrated the most potent inhibition (IC50 = 2.81 µM) and was characterized as a non-competitive inhibitor. Through a combination assay with fluorescence quenching, 3D fluorescence spectra, CD spectra, and molecular docking, we elucidated that CTL26 formed a complex with α-glucosidase via hydrogen bondings and hydrophobic interactions, leading to α-glucosidase conformation changes that impaired enzymatic activity. In vivo studies revealed that oral administration of CTL26 (25 and 50 mg/kg/d) reduced fasting blood glucose levels, enhanced glucose tolerance, and ameliorated lipid abnormalities in diabetic mice. These findings positioned CTL26 as a promising candidate for the development of α-glucosidase inhibitors with anti-diabetic potential.


Subject(s)
Carbolines , Diabetes Mellitus, Experimental , Glycoside Hydrolase Inhibitors , Semicarbazides , alpha-Glucosidases , Glycoside Hydrolase Inhibitors/pharmacology , Glycoside Hydrolase Inhibitors/chemical synthesis , Glycoside Hydrolase Inhibitors/chemistry , Animals , alpha-Glucosidases/metabolism , Carbolines/pharmacology , Carbolines/chemistry , Carbolines/chemical synthesis , Semicarbazides/pharmacology , Semicarbazides/chemistry , Semicarbazides/chemical synthesis , Mice , Structure-Activity Relationship , Diabetes Mellitus, Experimental/drug therapy , Hypoglycemic Agents/pharmacology , Hypoglycemic Agents/chemical synthesis , Hypoglycemic Agents/chemistry , Molecular Structure , Molecular Docking Simulation , Dose-Response Relationship, Drug , Male , Blood Glucose/drug effects , Blood Glucose/metabolism , Blood Glucose/analysis , Humans
16.
Nat Microbiol ; 9(8): 1979-1992, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38862603

ABSTRACT

Dimethylsulfoniopropionate (DMSP) is an abundant marine organosulfur compound with roles in stress protection, chemotaxis, nutrient and sulfur cycling and climate regulation. Here we report the discovery of a bifunctional DMSP biosynthesis enzyme, DsyGD, in the transamination pathway of the rhizobacterium Gynuella sunshinyii and some filamentous cyanobacteria not previously known to produce DMSP. DsyGD produces DMSP through its N-terminal DsyG methylthiohydroxybutyrate S-methyltransferase and C-terminal DsyD dimethylsulfoniohydroxybutyrate decarboxylase domains. Phylogenetically distinct DsyG-like proteins, termed DSYE, with methylthiohydroxybutyrate S-methyltransferase activity were found in diverse and environmentally abundant algae, comprising a mix of low, high and previously unknown DMSP producers. Algae containing DSYE, particularly bloom-forming Pelagophyceae species, were globally more abundant DMSP producers than those with previously described DMSP synthesis genes. This work greatly increases the number and diversity of predicted DMSP-producing organisms and highlights the importance of Pelagophyceae and other DSYE-containing algae in global DMSP production and sulfur cycling.


Subject(s)
Phylogeny , Sulfonium Compounds , Sulfonium Compounds/metabolism , Cyanobacteria/genetics , Cyanobacteria/metabolism , Cyanobacteria/enzymology , Methyltransferases/metabolism , Methyltransferases/genetics , Bacterial Proteins/metabolism , Bacterial Proteins/genetics , Biosynthetic Pathways/genetics
17.
Sci Rep ; 14(1): 12718, 2024 06 03.
Article in English | MEDLINE | ID: mdl-38830921

ABSTRACT

This study evaluated retinal and choroidal microvascular changes in night shift medical workers and its correlation with melatonin level. Night shift medical workers (group A, 25 workers) and non-night shift workers (group B, 25 workers) were recruited. The images of macula and optic nerve head were obtained by swept-source OCT-angiography. Vessel density of retina, choriocapillaris (CC), choriocapillaris flow deficit (CC FD), choroidal thickness (CT) and choroidal vascularity index (CVI) were measured. 6-sulfatoxymelatonin concentration was analyzed from the morning urine. CC FD and CVI were significantly decreased and CT was significantly increased in group A (all P < 0.05). 6-sulfatoxymelatonin concentration was significantly lower in group A (P < 0.05), which was significantly positively correlated with CC FD size (r = 0.318, P = 0.024) and CVI of the most regions (maximum r-value was 0.482, P < 0.001), and was significantly negatively associated with CT of all regions (maximum r-value was - 0.477, P < 0.001). In night shift medical workers, the reduction of melatonin was significantly correlated with CT thickening, CVI reduction and CC FD reduction, which suggested that they might have a higher risk of eye diseases. CC FD could be a sensitive and accurate indicator to reflect CC perfusion.


Subject(s)
Choroid , Melatonin , Microvessels , Retinal Vessels , Tomography, Optical Coherence , Humans , Choroid/blood supply , Choroid/diagnostic imaging , Tomography, Optical Coherence/methods , Male , Adult , Female , Melatonin/urine , Melatonin/analogs & derivatives , Microvessels/diagnostic imaging , Retinal Vessels/diagnostic imaging , Middle Aged , Shift Work Schedule/adverse effects , Angiography/methods , Retina/diagnostic imaging
18.
Nature ; 630(8016): 329-334, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38867129

ABSTRACT

Artificial Kitaev chains can be used to engineer Majorana bound states (MBSs) in superconductor-semiconductor hybrids1-4. In this work, we realize a two-site Kitaev chain in a two-dimensional electron gas by coupling two quantum dots through a region proximitized by a superconductor. We demonstrate systematic control over inter-dot couplings through in-plane rotations of the magnetic field and via electrostatic gating of the proximitized region. This allows us to tune the system to sweet spots in parameter space, where robust correlated zero-bias conductance peaks are observed in tunnelling spectroscopy. To study the extent of hybridization between localized MBSs, we probe the evolution of the energy spectrum with magnetic field and estimate the Majorana polarization, an important metric for Majorana-based qubits5,6. The implementation of a Kitaev chain on a scalable and flexible two-dimensional platform provides a realistic path towards more advanced experiments that require manipulation and readout of multiple MBSs.

19.
J Virol ; 98(7): e0045824, 2024 Jul 23.
Article in English | MEDLINE | ID: mdl-38814067

ABSTRACT

Tryptophan metabolism plays a crucial role in facilitating various cellular processes essential for maintaining normal cellular function. Indoleamine 2,3-dioxygenase 1 (IDO1) catalyzes the conversion of tryptophan (Trp) into kynurenine (Kyn), thereby initiating the degradation of Trp. The resulting Kyn metabolites have been implicated in the modulation of immune responses. Currently, the role of IDO1-mediated tryptophan metabolism in the process of viral infection remains relatively unknown. In this study, we discovered that classical swine fever virus (CSFV) infection of PK-15 cells can induce the expression of IDO1, thereby promoting tryptophan metabolism. IDO1 can negatively regulate the NF-κB signaling by mediating tryptophan metabolism, thereby facilitating CSFV replication. We found that silencing the IDO1 gene enhances the expression of IFN-α, IFN-ß, and IL-6 by activating the NF-κB signaling pathway. Furthermore, our observations indicate that both silencing the IDO1 gene and administering exogenous tryptophan can inhibit CSFV replication by counteracting the cellular autophagy induced by Rapamycin. This study reveals a novel mechanism of IDO1-mediated tryptophan metabolism in CSFV infection, providing new insights and a theoretical basis for the treatment and control of CSFV.IMPORTANCEIt is well known that due to the widespread use of vaccines, the prevalence of classical swine fever (CSF) is shifting towards atypical and invisible infections. CSF can disrupt host metabolism, leading to persistent immune suppression in the host and causing significant harm when co-infected with other diseases. Changes in the host's metabolic profiles, such as increased catabolic metabolism of amino acids and the production of immunoregulatory metabolites and their derivatives, can also influence virus replication. Mammals utilize various pathways to modulate immune responses through amino acid utilization, including increased catabolic metabolism of amino acids and the production of immunoregulatory metabolites and their derivatives, thereby limiting viral replication. Therefore, this study proposes that targeting the modulation of tryptophan metabolism may represent an effective approach to control the progression of CSF.


Subject(s)
Classical Swine Fever Virus , Indoleamine-Pyrrole 2,3,-Dioxygenase , NF-kappa B , Signal Transduction , Tryptophan , Virus Replication , Tryptophan/metabolism , Animals , Indoleamine-Pyrrole 2,3,-Dioxygenase/metabolism , Indoleamine-Pyrrole 2,3,-Dioxygenase/genetics , NF-kappa B/metabolism , Swine , Classical Swine Fever Virus/physiology , Cell Line , Kynurenine/metabolism , Classical Swine Fever/virology , Classical Swine Fever/metabolism , Autophagy
20.
Cell Mol Gastroenterol Hepatol ; 18(3): 101364, 2024.
Article in English | MEDLINE | ID: mdl-38788898

ABSTRACT

BACKGROUND & AIMS: Necrotizing enterocolitis (NEC) is a life-threatening disease affecting mostly the ileum of preemies. Intestinal epithelial cell (IEC) apoptosis contributes to NEC pathogenesis. However, how scattered crypt IEC apoptosis leads to NEC with excessive villus epithelial necrosis remains unclear. METHODS: A novel triple-transgenic mouse model, namely, 3xTg-iAPcIEC (inducible apoptosis phenotype in crypt-IEC), was developed to induce IEC-specific overexpression of Fasl transgene using doxycycline (Dox)-inducible tetO-rtTA system and villin-cre technology. The 3-days-old neonatal 3xTg-iAPcIEC mice and their littermate controls were subcutaneously (s.c.) challenged with a single dose of Dox. Intestinal tissues were processed at different time points to examine scattered crypt IEC apoptosis-mediated NEC development. Gene knockout technology, antibody-mediated cell depletion, and antibiotic-facilitated Gram-positive bacteria depletion were used to study mechanisms. RESULTS: Treatment of 3xTg-iAPcIEC mouse pups with Dox induces scattered crypt IEC apoptosis followed by crypt inflammation and excessive villous necrosis resembling NEC. This progression correlated with elevated Ifng, Rip3, CD8+ T cells, and Gram-positive bacteria in the ileum. Mechanistically, IFN-γ and RIP3-activated signals mediate the effect of scattered crypt IEC apoptosis on the induction of intestinal crypt inflammation and villous necrosis. Meanwhile, pathophysiological events of CD8+ T cell infiltration and dysbiosis with Gram-positive bacteria primarily contribute to excessive villous inflammation and necrosis. Notably, blocking any of these events protects against NEC development in 3xTg-iAPcIEC mouse pups, underlining their central roles in NEC pathogenesis. CONCLUSIONS: Scattered crypt IEC apoptosis induces NEC in mouse pups via IFN-γ, RIP3, CD8+ T cells, and Gram-positive bacteria-mediated comprehensive pathophysiological events. Our findings may advance knowledge in the prevention and treatment of NEC.


Subject(s)
Apoptosis , Disease Models, Animal , Enterocolitis, Necrotizing , Fas Ligand Protein , Interferon-gamma , Intestinal Mucosa , Mice, Transgenic , Animals , Enterocolitis, Necrotizing/pathology , Enterocolitis, Necrotizing/metabolism , Mice , Intestinal Mucosa/pathology , Intestinal Mucosa/microbiology , Intestinal Mucosa/immunology , Interferon-gamma/metabolism , Fas Ligand Protein/metabolism , Receptor-Interacting Protein Serine-Threonine Kinases/metabolism , Receptor-Interacting Protein Serine-Threonine Kinases/genetics , Epithelial Cells/pathology , Epithelial Cells/metabolism , CD8-Positive T-Lymphocytes/immunology , Necrosis , Animals, Newborn , Doxycycline/pharmacology , Humans , Ileum/pathology , Ileum/immunology
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