ABSTRACT
The ClC-3 chloride/proton exchanger is both physiologically and pathologically critical, as it is potentiated by ATP to detect metabolic energy level and point mutations in ClC-3 lead to severe neurodegenerative diseases in human. However, why this exchanger is differentially modulated by ATP, ADP or AMP and how mutations caused gain-of-function remains largely unknow. Here we determine the high-resolution structures of dimeric wildtype ClC-3 in the apo state and in complex with ATP, ADP and AMP, and the disease-causing I607T mutant in the apo and ATP-bounded state by cryo-electron microscopy. In combination with patch-clamp recordings and molecular dynamic simulations, we reveal how the adenine nucleotides binds to ClC-3 and changes in ion occupancy between apo and ATP-bounded state. We further observe I607T mutation induced conformational changes and augments in current. Therefore, our study not only lays the structural basis of adenine nucleotides regulation in ClC-3, but also clearly indicates the target region for drug discovery against ClC-3 mediated neurodegenerative diseases.
Subject(s)
Adenosine Triphosphate , Chloride Channels , Cryoelectron Microscopy , Molecular Dynamics Simulation , Neurodegenerative Diseases , Chloride Channels/metabolism , Chloride Channels/genetics , Chloride Channels/chemistry , Humans , Adenosine Triphosphate/metabolism , Neurodegenerative Diseases/metabolism , Neurodegenerative Diseases/genetics , Neurodegenerative Diseases/pathology , Adenine Nucleotides/metabolism , Patch-Clamp Techniques , Mutation , Adenosine Diphosphate/metabolism , HEK293 Cells , Adenosine Monophosphate/metabolism , Animals , Protein ConformationABSTRACT
Distinguishing arteries from veins in the cerebral cortex is critical for studying hemodynamics under pathophysiological conditions, which plays an important role in the diagnosis and treatment of various vessel-related diseases. However, due to the complexity of the cerebral vascular network, it is challenging to identify arteries and veins in vivo. Here, we demonstrate an artery-vein separation method that employs a combination of multiple scanning modes of two-photon microscopy and a custom-designed stereoscopic fixation device for mice. In this process, we propose a novel method for determining the line scanning direction, which allows us to determine the blood flow directions. The vasculature branches have been identified using an optimized z-stack scanning mode, followed by the separation of blood vessel types according to the directions of blood flow and branching patterns. Using this strategy, the penetrating arterioles and penetrating venules in awake mice could be accurately identified and the type of cerebral thrombus has been also successfully isolated without any empirical knowledge or algorithms. Our research presents a new, more accurate, and efficient method for cortical artery-vein separation in awake mice, providing a useful strategy for the application of two-photon microscopy in the study of cerebrovascular pathophysiology.
ABSTRACT
Plastic waste in the environment causes significant environmental pollution. The potential of using chemical methods for upcycling plastic waste offers a dual solution to ensure resource sustainability and environmental restoration. This article provides a comprehensive overview of the latest technologies driven by solar-driven, electro/photoelectrochemical-catalytic, and microwave-assisted methods for the conversion of plastics into various valuable chemicals. It emphasizes selective conversion during the plastic transformation process, elucidates reaction pathways, and optimizes product selectivity. Finally, the article offers insights into the future developments of chemical upcycling of polyesters.
ABSTRACT
BACKGROUND: Systemic lupus erythematosus (SLE), an autoimmune disease, is characterised by B-cell abnormalities and a loss of tolerance that can produce autoantibody. However, the imperative genes and molecular pathways involved in the change of B cell populations remain unclear. METHODS: The expression of B cell subsets between SLE and healthy controls (HCs) was detected based on micro-array transcriptome data. The Weighted Gene Co-Expression Network Analysis (WGCNA) further revealed the co-expression modules of naïve and memory B cells. Whereafter, we performed the functional enrichment analysis, Protein-protein interaction (PPI) networks construction and feature selection to screen hub genes. Ultimately, we recruited SLE patients and HCs from the Second Hospital of Shanxi Medical University and further verified these genes in transcriptome sequencing samples. RESULTS: Total of 1087 SLE patients and 86 HCs constituted in the study. Compared to HCs, the levels of peripheral naïve B cells of SLE patients decreased, while memory B cells increased. WGCNA identified two modules with the highest correlation for the subsequent analysis. The purple module was primarily in connection with naïve B cells, and the GO analysis indicated that these genes were mainly abundant in B cell activation. The blue module relevant to memory B cells was most significantly enriched in the "defence response to virus" correlation pathway. Then we screened six hub genes by PPI and feature selection. Finally, four biomarkers (IFI27, IFITM1, MX2, IRF7) were identified by transcriptome sequencing verification. CONCLUSION: Our study identified hub genes and key pathways associated with the naïve and memory B cells respectively, which may offer novel insights into the behaviours of B cells and the pathogenesis of SLE.
Subject(s)
B-Lymphocyte Subsets , Lupus Erythematosus, Systemic , Humans , Transcriptome , Gene Expression Profiling , Biomarkers/metabolismABSTRACT
An extensively-drug resistant (XDR) Escherichia coli W60 was isolated from the urine sample of a patient. The genetic basis for its XDR phenotype was investigated, particularly the basis for its resistance toward ß-lactam/BLI (ß-Lactamase Inhibitor) combinations. Following determination of the XDR phenotype, third generation genomic sequencing was performed to identify genetic structures in E. coli W60. Further cloning analysis was performed to identify determinants of ß-lactam/BLI combination resistance. It was found that E. coli W60 is resistant to nearly all of the tested antibiotics including all commonly used ß-lactam/BLI combinations. Analysis of the genomic structures in E. coli W60 showed two novel transferable plasmids are responsible for the resistance phenotypes. Further genetic analysis showed bla NDM-5 leads to high resistance to ß-lactam/BLI combinations, which was enhanced by co-expressing ble MBL. pECW602 harbors a truncated bla TEM that is not functional due to the loss of the N-terminal signal peptide coding region. Research performed in this work leads to several significant conclusions: the XDR phenotype of E. coli W60 can be attributed to the presence of transferable multidrug resistance plasmids; NDM-5 confers high resistance to ß-lactam/BLI combinations; co-expression of ble MBL enhances resistance caused by NDM-5; the signal peptides of TEM type ß-lactamases are essential for their secretion and function. Findings of this work show the danger of transferable multidrug resistance plasmids and metallo-ß-lactamases, both of which should be given more attention in the analysis and treatment of multidrug resistant pathogens.