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1.
Nature ; 610(7933): 768-774, 2022 10.
Article in English | MEDLINE | ID: mdl-36261532

ABSTRACT

Haem is an iron-containing tetrapyrrole that is critical for a variety of cellular and physiological processes1-3. Haem binding proteins are present in almost all cellular compartments, but the molecular mechanisms that regulate the transport and use of haem within the cell remain poorly understood2,3. Here we show that haem-responsive gene 9 (HRG-9) (also known as transport and Golgi organization 2 (TANGO2)) is an evolutionarily conserved haem chaperone with a crucial role in trafficking haem out of haem storage or synthesis sites in eukaryotic cells. Loss of Caenorhabditis elegans hrg-9 and its paralogue hrg-10 results in the accumulation of haem in lysosome-related organelles, the haem storage site in worms. Similarly, deletion of the hrg-9 homologue TANGO2 in yeast and mammalian cells induces haem overload in mitochondria, the site of haem synthesis. We demonstrate that TANGO2 binds haem and transfers it from cellular membranes to apo-haemoproteins. Notably, homozygous tango2-/- zebrafish larvae develop pleiotropic symptoms including encephalopathy, cardiac arrhythmia and myopathy, and die during early development. These defects partially resemble the symptoms of human TANGO2-related metabolic encephalopathy and arrhythmias, a hereditary disease caused by mutations in TANGO24-8. Thus, the identification of HRG-9 as an intracellular haem chaperone provides a biological basis for exploring the aetiology and treatment of TANGO2-related disorders.


Subject(s)
Caenorhabditis elegans Proteins , Caenorhabditis elegans , Heme , Animals , Humans , Arrhythmias, Cardiac/metabolism , Brain Diseases/metabolism , Caenorhabditis elegans/cytology , Caenorhabditis elegans/metabolism , Caenorhabditis elegans Proteins/metabolism , Heme/metabolism , Mitochondria/metabolism , Molecular Chaperones/metabolism , Zebrafish/genetics , Zebrafish/metabolism
2.
Nature ; 591(7848): 131-136, 2021 03.
Article in English | MEDLINE | ID: mdl-33472215

ABSTRACT

Plasma membrane rupture (PMR) is the final cataclysmic event in lytic cell death. PMR releases intracellular molecules known as damage-associated molecular patterns (DAMPs) that propagate the inflammatory response1-3. The underlying mechanism of PMR, however, is unknown. Here we show that the cell-surface NINJ1 protein4-8, which contains two transmembrane regions, has an essential role in the induction of PMR. A forward-genetic screen of randomly mutagenized mice linked NINJ1 to PMR. Ninj1-/- macrophages exhibited impaired PMR in response to diverse inducers of pyroptotic, necrotic and apoptotic cell death, and were unable to release numerous intracellular proteins including HMGB1 (a known DAMP) and LDH (a standard measure of PMR). Ninj1-/- macrophages died, but with a distinctive and persistent ballooned morphology, attributable to defective disintegration of bubble-like herniations. Ninj1-/- mice were more susceptible than wild-type mice to infection with Citrobacter rodentium, which suggests a role for PMR in anti-bacterial host defence. Mechanistically, NINJ1 used an evolutionarily conserved extracellular domain for oligomerization and subsequent PMR. The discovery of NINJ1 as a mediator of PMR overturns the long-held idea that cell death-related PMR is a passive event.


Subject(s)
Cell Adhesion Molecules, Neuronal/metabolism , Cell Death , Cell Membrane/metabolism , Nerve Growth Factors/metabolism , Animals , Apoptosis , Cell Adhesion Molecules, Neuronal/chemistry , Cell Adhesion Molecules, Neuronal/genetics , Cell Death/genetics , Female , Humans , Macrophages , Male , Mice , Mutation , Necrosis , Nerve Growth Factors/chemistry , Nerve Growth Factors/genetics , Protein Multimerization , Pyroptosis/genetics
3.
Nature ; 587(7833): 275-280, 2020 11.
Article in English | MEDLINE | ID: mdl-32971525

ABSTRACT

Mutations in the death receptor FAS1,2 or its ligand FASL3 cause autoimmune lymphoproliferative syndrome, whereas mutations in caspase-8 or its adaptor FADD-which mediate cell death downstream of FAS and FASL-cause severe immunodeficiency in addition to autoimmune lymphoproliferative syndrome4-6. Mouse models have corroborated a role for FADD-caspase-8 in promoting inflammatory responses7-12, but the mechanisms that underlie immunodeficiency remain undefined. Here we identify NEDD4-binding protein 1 (N4BP1) as a suppressor of cytokine production that is cleaved and inactivated by caspase-8. N4BP1 deletion in mice increased the production of select cytokines upon stimulation of the Toll-like receptor (TLR)1-TLR2 heterodimer (referred to herein as TLR1/2), TLR7 or TLR9, but not upon engagement of TLR3 or TLR4. N4BP1 did not suppress TLR3 or TLR4 responses in wild-type macrophages, owing to TRIF- and caspase-8-dependent cleavage of N4BP1. Notably, the impaired production of cytokines in response to TLR3 and TLR4 stimulation of caspase-8-deficient macrophages13 was largely rescued by co-deletion of N4BP1. Thus, the persistence of intact N4BP1 in caspase-8-deficient macrophages impairs their ability to mount robust cytokine responses. Tumour necrosis factor (TNF), like TLR3 or TLR4 agonists, also induced caspase-8-dependent cleavage of N4BP1, thereby licensing TRIF-independent TLRs to produce higher levels of inflammatory cytokines. Collectively, our results identify N4BP1 as a potent suppressor of cytokine responses; reveal N4BP1 cleavage by caspase-8 as a point of signal integration during inflammation; and offer an explanation for immunodeficiency caused by mutations of FADD and caspase-8.


Subject(s)
Caspase 8/metabolism , Cytokines/immunology , Immunity, Innate/immunology , Nuclear Proteins/metabolism , RNA-Binding Proteins/metabolism , Adaptor Proteins, Vesicular Transport/metabolism , Animals , Cells, Cultured , Cytokines/antagonists & inhibitors , Humans , Inflammation/immunology , Mice , Mice, Inbred C57BL , Toll-Like Receptor 3/metabolism , Toll-Like Receptor 4/metabolism , Tumor Necrosis Factor-alpha/immunology , Tumor Necrosis Factor-alpha/metabolism
4.
Ann Intern Med ; 2024 Jul 02.
Article in English | MEDLINE | ID: mdl-38950397

ABSTRACT

BACKGROUND: Acupuncture may improve degenerative lumbar spinal stenosis (DLSS), but evidence is insufficient. OBJECTIVE: To investigate the effect of acupuncture for DLSS. DESIGN: Multicenter randomized clinical trial. (ClinicalTrials.gov: NCT03784729). SETTING: 5 hospitals in China. PARTICIPANTS: Patients with DLSS and predominantly neurogenic claudication pain symptoms. INTERVENTION: 18 sessions of acupuncture or sham acupuncture (SA) over 6 weeks, with 24-week follow-up after treatment. MEASUREMENTS: The primary outcome was change from baseline in the modified Roland-Morris Disability Questionnaire ([RMDQ] score range, 0 to 24; minimal clinically important difference [MCID], 2 to 3). Secondary outcomes were the proportion of participants achieving minimal (30% reduction from baseline) and substantial (50% reduction from baseline) clinically meaningful improvement per the modified RMDQ. RESULTS: A total of 196 participants (98 in each group) were enrolled. The mean modified RMDQ score was 12.6 (95% CI, 11.8 to 13.4) in the acupuncture group and 12.7 (CI, 12.0 to 13.3) in the SA group at baseline, and decreased to 8.1 (CI, 7.1 to 9.1) and 9.5 (CI, 8.6 to 10.4) at 6 weeks, with an adjusted difference in mean change of -1.3 (CI, -2.6 to -0.03; P = 0.044), indicating a 43.3% greater improvement compared with SA. The between-group difference in the proportion of participants achieving minimal and substantial clinically meaningful improvement was 16.0% (CI, 1.6% to 30.4%) and 12.6% (CI, -1.0% to 26.2%) at 6 weeks. Three cases of treatment-related adverse events were reported in the acupuncture group, and 3 were reported in the SA group. All events were mild and transient. LIMITATION: The SA could produce physiologic effects. CONCLUSION: Acupuncture may relieve pain-specific disability among patients with DLSS and predominantly neurogenic claudication pain symptoms, although the difference with SA did not reach MCID. The effects may last 24 weeks after 6-week treatment. PRIMARY FUNDING SOURCE: 2019 National Administration of Traditional Chinese Medicine "Project of building evidence-based practice capacity for TCM-Project BEBPC-TCM" (NO. 2019XZZX-ZJ).

5.
Proc Natl Acad Sci U S A ; 119(38): e2123117119, 2022 09 20.
Article in English | MEDLINE | ID: mdl-36099298

ABSTRACT

Acinetobacter baumannii is a clinically important, predominantly health care-associated gram-negative bacterium with high rates of emerging resistance worldwide. Given the urgent need for novel antibacterial therapies against A. baumannii, we focused on inhibiting lipoprotein biosynthesis, a pathway that is essential for envelope biogenesis in gram-negative bacteria. The natural product globomycin, which inhibits the essential type II signal peptidase prolipoprotein signal peptidase (LspA), is ineffective against wild-type A. baumannii clinical isolates due to its poor penetration through the outer membrane. Here, we describe a globomycin analog, G5132, that is more potent against wild-type and clinical A. baumannii isolates. Mutations leading to G5132 resistance in A. baumannii map to the signal peptide of a single hypothetical gene, which we confirm encodes an alanine-rich lipoprotein and have renamed lirL (prolipoprotein signal peptidase inhibitor resistance lipoprotein). LirL is a highly abundant lipoprotein primarily localized to the inner membrane. Deletion of lirL leads to G5132 resistance, inefficient cell division, increased sensitivity to serum, and attenuated virulence. Signal peptide mutations that confer resistance to G5132 lead to the accumulation of diacylglyceryl-modified LirL prolipoprotein in untreated cells without significant loss in cell viability, suggesting that these mutations overcome a block in lipoprotein biosynthetic flux by decreasing LirL prolipoprotein substrate sensitivity to processing by LspA. This study characterizes a lipoprotein that plays a critical role in resistance to LspA inhibitors and validates lipoprotein biosynthesis as a antibacterial target in A. baumannii.


Subject(s)
Acinetobacter baumannii , Anti-Bacterial Agents , Aspartic Acid Endopeptidases , Bacterial Proteins , Drug Resistance, Bacterial , Furans , Gene Deletion , Lipoproteins , Protease Inhibitors , Pyridines , Acinetobacter baumannii/drug effects , Acinetobacter baumannii/enzymology , Acinetobacter baumannii/genetics , Anti-Bacterial Agents/pharmacology , Aspartic Acid Endopeptidases/genetics , Bacterial Proteins/genetics , Drug Resistance, Bacterial/genetics , Furans/pharmacology , Lipoproteins/biosynthesis , Lipoproteins/genetics , Peptides/pharmacology , Protease Inhibitors/pharmacology , Protein Sorting Signals/genetics , Pyridines/pharmacology
6.
Hepatology ; 77(4): 1303-1318, 2023 04 01.
Article in English | MEDLINE | ID: mdl-35788956

ABSTRACT

BACKGROUND AND AIM: Injury to hepatocyte mitochondria is common in metabolic dysfunction-associated fatty liver disease. Here, we investigated whether changes in the content of essential fatty acid-derived lipid autacoids affect hepatocyte mitochondrial bioenergetics and metabolic efficiency. APPROACH AND RESULTS: The study was performed in transgenic mice for the fat-1 gene, which allows the endogenous replacement of the membrane omega-6-polyunsaturated fatty acid (PUFA) composition by omega-3-PUFA. Transmission electron microscopy revealed that hepatocyte mitochondria of fat-1 mice had more abundant intact cristae and higher mitochondrial aspect ratio. Fat-1 mice had increased expression of oxidative phosphorylation complexes I and II and translocases of both inner (translocase of inner mitochondrial membrane 44) and outer (translocase of the outer membrane 20) mitochondrial membranes. Fat-1 mice also showed increased mitofusin-2 and reduced dynamin-like protein 1 phosphorylation, which mediate mitochondrial fusion and fission, respectively. Mitochondria of fat-1 mice exhibited enhanced oxygen consumption rate, fatty acid ß-oxidation, and energy substrate utilization as determined by high-resolution respirometry, [1- 14 C]-oleate oxidation and nicotinamide adenine dinucleotide hydride/dihydroflavine-adenine dinucleotide production, respectively. Untargeted lipidomics identified a rich hepatic omega-3-PUFA composition and a specific docosahexaenoic acid (DHA)-enriched lipid fingerprint in fat-1 mice. Targeted lipidomics uncovered a higher content of DHA-derived lipid autacoids, namely resolvin D1 and maresin 1, which rescued hepatocytes from TNFα-induced mitochondrial dysfunction, and unblocked the tricarboxylic acid cycle flux and metabolic utilization of long-chain acyl-carnitines, amino acids, and carbohydrates. Importantly, fat-1 mice were protected against mitochondrial injury induced by obesogenic and fibrogenic insults. CONCLUSION: Our data uncover the importance of a lipid membrane composition rich in DHA and its lipid autacoid derivatives to have optimal hepatic mitochondrial and metabolic efficiency.


Subject(s)
Fatty Acids, Omega-3 , Non-alcoholic Fatty Liver Disease , Mice , Animals , Conservation of Energy Resources , Fatty Acids, Omega-3/chemistry , Fatty Acids, Omega-3/metabolism , Fatty Acids, Omega-3/pharmacology , Non-alcoholic Fatty Liver Disease/metabolism , Liver/metabolism , Mitochondria/metabolism , Fatty Acids, Omega-6/chemistry , Fatty Acids, Omega-6/metabolism , Fatty Acids, Omega-6/pharmacology , Mice, Transgenic , Fatty Acids/metabolism
7.
FASEB J ; 37(2): e22757, 2023 02.
Article in English | MEDLINE | ID: mdl-36607310

ABSTRACT

Vesicle trafficking is a fundamental cellular process that controls the transport of various proteins and cargos between cellular compartments in eukaryotes. Using a combination of genome-wide CRISPR screening in mammalian cells and RNAi screening in Caenorhabditis elegans, we identify chaperonin containing TCP-1 subunit 4 (CCT4) as a critical regulator of protein secretion and vesicle trafficking. In C. elegans, deficiency of cct-4 as well as other CCT subunits impairs the trafficking of endocytic markers in intestinal cells, and this defect resembles that of dyn-1 RNAi worms. Consistent with these findings, the silencing of CCT4 in human cells leads to defective endosomal trafficking, and this defect can be rescued by the dynamin activator Ryngo 1-23. These results suggest that the cytosolic chaperonin CCT may regulate vesicle trafficking by promoting the folding of dynamin in addition to its known substrate tubulin. Our findings establish an essential role for the CCT chaperonin in regulating vesicle trafficking, and provide new insights into the regulation of vesicle trafficking and the cellular function of the cytosolic chaperonin.


Subject(s)
Caenorhabditis elegans , Chaperonin Containing TCP-1 , Animals , Humans , Chaperonin Containing TCP-1/genetics , Chaperonin Containing TCP-1/metabolism , Caenorhabditis elegans/genetics , Caenorhabditis elegans/metabolism , Clustered Regularly Interspaced Short Palindromic Repeats , Chaperonins/genetics , Chaperonins/metabolism , Tubulin/metabolism , Cytosol/metabolism , Protein Folding , Mammals/metabolism
8.
Mol Psychiatry ; 28(10): 4421-4437, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37604976

ABSTRACT

Spouses of Alzheimer's disease (AD) patients are at a higher risk of developing incidental dementia. However, the causes and underlying mechanism of this clinical observation remain largely unknown. One possible explanation is linked to microbiota dysbiosis, a condition that has been associated with AD. However, it remains unclear whether gut microbiota dysbiosis can be transmitted from AD individuals to non-AD individuals and contribute to the development of AD pathogenesis and cognitive impairment. We, therefore, set out to perform both animal studies and clinical investigation by co-housing wild-type mice and AD transgenic mice, analyzing microbiota via 16S rRNA gene sequencing, measuring short-chain fatty acid amounts, and employing behavioral test, mass spectrometry, site-mutations and other methods. The present study revealed that co-housing between wild-type mice and AD transgenic mice or administrating feces of AD transgenic mice to wild-type mice resulted in AD-associated gut microbiota dysbiosis, Tau phosphorylation, and cognitive impairment in the wild-type mice. Gavage with Lactobacillus and Bifidobacterium restored these changes in the wild-type mice. The oral and gut microbiota of AD patient partners resembled that of AD patients but differed from healthy controls, indicating the transmission of microbiota. The underlying mechanism of these findings includes that the butyric acid-mediated acetylation of GSK3ß at lysine 15 regulated its phosphorylation at serine 9, consequently impacting Tau phosphorylation. Pending confirmative studies, these results provide insight into a potential link between the transmission of AD-associated microbiota dysbiosis and development of cognitive impairment, which underscore the need for further research in this area.


Subject(s)
Alzheimer Disease , Cognitive Dysfunction , Gastrointestinal Microbiome , Humans , Mice , Animals , Alzheimer Disease/genetics , Dysbiosis , RNA, Ribosomal, 16S/genetics , Cognition , Mice, Transgenic , Gastrointestinal Microbiome/genetics
9.
Epilepsia ; 65(1): 204-217, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37746768

ABSTRACT

OBJECTIVE: γ-Aminobutyric acid type A (GABAA ) receptor subunit gene mutations are major causes of various epilepsy syndromes, including severe kinds such as Dravet syndrome. Although the GABAA receptor is a major target for antiseizure medications, treating GABAA receptor mutations with receptor channel modulators is ineffective. Here, we determined the effect of a novel treatment with 4-phenylbutyrate (PBA) in Gabrg2+/Q390X knockin mice associated with Dravet syndrome. METHODS: We used biochemistry in conjunction with differential tagging of the wild-type and the mutant alleles, live brain slice surface biotinylation, microsome isolation, patch-clamp whole-cell recordings, and video-monitoring synchronized electroencephalographic (EEG) recordings in Gabrg2+/Q390X mice to determine the effect of PBA in vitro with recombinant GABAA receptors and in vivo with knockin mice. RESULTS: We found that PBA reduced the mutant γ2(Q390X) subunit protein aggregates, enhanced the wild-type GABAA receptor subunits' trafficking, and increased the membrane expression of the wild-type receptors. PBA increased the current amplitude of GABA-evoked current in human embryonic kidney 293T cells and the neurons bearing the γ2(Q390X) subunit protein. PBA also proved to reduce endoplasmic reticulum (ER) stress caused by the mutant γ2(Q390X) subunit protein, as well as mitigating seizures and EEG abnormalities in the Gabrg2+/Q390X mice. SIGNIFICANCE: This research has unveiled a promising and innovative approach for treating epilepsy linked to GABAA receptor mutations through an unconventional antiseizure mechanism. Rather than directly modulating the affected mutant channel, PBA facilitates the folding and transportation of wild-type receptor subunits to the cell membrane and synapse. Combining these findings with our previous study, which demonstrated PBA's efficacy in restoring GABA transporter 1 (encoded by SLC6A1) function, we propose that PBA holds significant potential for a wide range of genetic epilepsies. Its ability to target shared molecular pathways involving mutant protein ER retention and impaired protein membrane trafficking suggests broad application in treating such conditions.


Subject(s)
Epilepsies, Myoclonic , Epilepsy , Phenylbutyrates , Mice , Humans , Animals , Receptors, GABA-A/genetics , Receptors, GABA-A/metabolism , Receptors, GABA/metabolism , Epilepsies, Myoclonic/drug therapy , Epilepsies, Myoclonic/genetics , Epilepsies, Myoclonic/complications , Seizures/complications , Epilepsy/genetics , gamma-Aminobutyric Acid , Endoplasmic Reticulum Stress/genetics
10.
Bioorg Med Chem Lett ; 102: 129678, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38408514

ABSTRACT

The dopamine transporter (DAT) is closely related to a variety of neurological disorders including Parkinson's disease (PD) and other neurodegenerative diseases. In vivo imaging of DAT with radio-labelled tracers has become a powerful technique in related disorders. The radioiodine-labelled tropane derivative [123I]FP-CIT ([123I]1a) is widely used in clinical single photon emission computed tomography (SPECT) imaging as a DAT imaging agent. To develop more metabolically stable DAT radioligands for accurate imaging, this work compared two novel deuterated tropane derivatives ([131I]1c-d) with non-deuterated tropane derivatives ([131I]1a-b). [131I]1a-d were obtained in high radiochemical purity (RCP) above 99 % with molar activities of 7.0-10.0 GBq/µmol. The [131I]1a and [131I]1c exhibited relatively higher affinity to DAT (Ki: 2.0-3.12 nM) than [131I]1b and [131I]1d. Biodistribution results showed that [131I]1c consistently exhibited a higher ratio of the target to non-target (striatum/cerebellum) than [131I]1a. Furthermore, metabolism studies indicated that the in vivo metabolic stability of [131I]1c was superior to that of [131I]1a. Ex vivo autoradiography showed that [131I]1c selectively localized on DAT-rich striatal regions and the specific signal could be blocked by DAT inhibitor. These results indicated that [131I]1c might be a potential probe for DAT SPECT imaging in the brain.


Subject(s)
Dopamine Plasma Membrane Transport Proteins , Iodine Radioisotopes , Dopamine Plasma Membrane Transport Proteins/metabolism , Iodine Radioisotopes/metabolism , Tissue Distribution , Tropanes , Tomography, Emission-Computed, Single-Photon/methods
11.
Brain ; 146(12): 5198-5208, 2023 12 01.
Article in English | MEDLINE | ID: mdl-37647852

ABSTRACT

Genetic variants in the SLC6A1 gene can cause a broad phenotypic disease spectrum by altering the protein function. Thus, systematically curated clinically relevant genotype-phenotype associations are needed to understand the disease mechanism and improve therapeutic decision-making. We aggregated genetic and clinical data from 172 individuals with likely pathogenic/pathogenic (lp/p) SLC6A1 variants and functional data for 184 variants (14.1% lp/p). Clinical and functional data were available for a subset of 126 individuals. We explored the potential associations of variant positions on the GAT1 3D structure with variant pathogenicity, altered molecular function and phenotype severity using bioinformatic approaches. The GAT1 transmembrane domains 1, 6 and extracellular loop 4 (EL4) were enriched for patient over population variants. Across functionally tested missense variants (n = 156), the spatial proximity from the ligand was associated with loss-of-function in the GAT1 transporter activity. For variants with complete loss of in vitro GABA uptake, we found a 4.6-fold enrichment in patients having severe disease versus non-severe disease (P = 2.9 × 10-3, 95% confidence interval: 1.5-15.3). In summary, we delineated associations between the 3D structure and variant pathogenicity, variant function and phenotype in SLC6A1-related disorders. This knowledge supports biology-informed variant interpretation and research on GAT1 function. All our data can be interactively explored in the SLC6A1 portal (https://slc6a1-portal.broadinstitute.org/).


Subject(s)
GABA Plasma Membrane Transport Proteins , Genetic Association Studies , Mutation, Missense , Humans , GABA Plasma Membrane Transport Proteins/genetics , GABA Plasma Membrane Transport Proteins/metabolism , Phenotype
12.
Nature ; 561(7722): 189-194, 2018 09.
Article in English | MEDLINE | ID: mdl-30209367

ABSTRACT

Multidrug-resistant bacteria are spreading at alarming rates, and despite extensive efforts no new class of antibiotic with activity against Gram-negative bacteria has been approved in over fifty years. Natural products and their derivatives have a key role in combating Gram-negative pathogens. Here we report chemical optimization of the arylomycins-a class of natural products with weak activity and limited spectrum-to obtain G0775, a molecule with potent, broad-spectrum activity against Gram-negative bacteria. G0775 inhibits the essential bacterial type I signal peptidase, a new antibiotic target, through an unprecedented molecular mechanism. It circumvents existing antibiotic resistance mechanisms and retains activity against contemporary multidrug-resistant Gram-negative clinical isolates in vitro and in several in vivo infection models. These findings demonstrate that optimized arylomycin analogues such as G0775 could translate into new therapies to address the growing threat of multidrug-resistant Gram-negative infections.


Subject(s)
Anti-Bacterial Agents/classification , Anti-Bacterial Agents/pharmacology , Gram-Negative Bacteria/drug effects , Peptides, Cyclic/pharmacology , Biocatalysis/drug effects , Biological Products/classification , Biological Products/pharmacology , Drug Resistance, Multiple, Bacterial/drug effects , Escherichia coli/enzymology , Gram-Negative Bacteria/enzymology , Gram-Negative Bacteria/pathogenicity , Gram-Negative Bacterial Infections/drug therapy , Gram-Negative Bacterial Infections/microbiology , Klebsiella pneumoniae/drug effects , Klebsiella pneumoniae/enzymology , Klebsiella pneumoniae/pathogenicity , Lysine/metabolism , Membrane Proteins/antagonists & inhibitors , Microbial Sensitivity Tests , Peptides, Cyclic/chemistry , Porins , Protein Binding , Protein Domains , Serine Endopeptidases , Substrate Specificity
13.
J Clin Periodontol ; 2024 May 27.
Article in English | MEDLINE | ID: mdl-38802320

ABSTRACT

AIM: This prospective cohort study investigated the association between periodontal diseases (PDs) and all-cause and cause-specific mortality. MATERIALS AND METHODS: We utilized adult participants recruited from six National Health and Nutrition Examination Survey cycles (1999-2014) and linked mortality data from the National Death Index up to December 2019. Baseline clinical periodontal examinations were performed by trained and calibrated examiners. All-cause and cause-specific mortality was modelled through multivariable Cox proportional hazards and Fine-Gray models to account for competing risks. All models were adjusted for demographic and lifestyle variables, clinical measurements and comorbidities. RESULTS: Overall, 15,030 participants were included, with a median length of follow-up of 9 years. Risk of all-cause mortality was 22% greater in people with PD than the control group (adjusted hazard ratio [HR]: 1.22, 95% confidence interval [CI]: 1.12-1.31). Risks of mortality by cardiovascular diseases (CVD), respiratory disease and diabetes were highest in participants with severe PD (CVD-sub-distribution HR [SHR]: 1.38, 95% CI: 1.16-1.64; respiratory-SHR: 1.62, 95% CI: 1.07-2.45; diabetes-SHR: 1.68, 95% CI: 1.12-2.53). CONCLUSIONS: Severe PD is associated with all-cause and cause-specific mortality among US adults after multivariable adjustment.

14.
J Chem Phys ; 160(16)2024 Apr 28.
Article in English | MEDLINE | ID: mdl-38661199

ABSTRACT

Nanoconfined water plays an important role in broad fields of science and engineering. Classical molecular dynamics (MD) simulations have been widely used to investigate water phases under nanoconfinement. The key ingredient of MD is the force field. In this study, we systematically investigated the performance of a recently introduced family of globally optimal water models, OPC and OPC3, and TIP4P/2005 in describing nanoconfined two-dimensional (2D) water ice. Our studies show that the melting points of the monolayer square ice (MSI) of all three water models are higher than the melting points of the corresponding bulk ice Ih. Under the same conditions, the melting points of MSI of OPC and TIP4P/2005 are the same and are ∼90 K lower than that of the OPC3 water model. In addition, we show that OPC and TIP4P/2005 water models are able to form a bilayer AA-stacked structure and a trilayer AAA-stacked structure, which are not the cases for the OPC3 model. Considering the available experimental data and first-principles simulations, we consider the OPC water model as a potential water model for 2D water ice MD studies.

15.
Int J Mol Sci ; 25(9)2024 Apr 23.
Article in English | MEDLINE | ID: mdl-38731820

ABSTRACT

A significant number of patients with genetic epilepsy do not obtain seizure freedom, despite developments in new antiseizure drugs, suggesting a need for novel therapeutic approaches. Many genetic epilepsies are associated with misfolded mutant proteins, including GABRG2(Q390X)-associated Dravet syndrome, which we have previously shown to result in intracellular accumulation of mutant GABAA receptor γ2(Q390X) subunit protein. Thus, a potentially promising therapeutic approach is modulation of proteostasis, such as increasing endoplasmic reticulum (ER)-associated degradation (ERAD). To that end, we have here identified an ERAD-associated E3 ubiquitin ligase, HRD1, among other ubiquitin ligases, as a strong modulator of wildtype and mutant γ2 subunit expression. Overexpressing HRD1 or knockdown of HRD1 dose-dependently reduced the γ2(Q390X) subunit. Additionally, we show that zonisamide (ZNS)-an antiseizure drug reported to upregulate HRD1-reduces seizures in the Gabrg2+/Q390X mouse. We propose that a possible mechanism for this effect is a partial rescue of surface trafficking of GABAA receptors, which are otherwise sequestered in the ER due to the dominant-negative effect of the γ2(Q390X) subunit. Furthermore, this partial rescue was not due to changes in ER chaperones BiP and calnexin, as total expression of these chaperones was unchanged in γ2(Q390X) models. Our results here suggest that leveraging the endogenous ERAD pathway may present a potential method to degrade neurotoxic mutant proteins like the γ2(Q390X) subunit. We also demonstrate a pharmacological means of regulating proteostasis, as ZNS alters protein trafficking, providing further support for the use of proteostasis regulators for the treatment of genetic epilepsies.


Subject(s)
Endoplasmic Reticulum , Epilepsies, Myoclonic , Proteolysis , Receptors, GABA-A , Epilepsies, Myoclonic/metabolism , Epilepsies, Myoclonic/genetics , Receptors, GABA-A/metabolism , Receptors, GABA-A/genetics , Animals , Endoplasmic Reticulum/metabolism , Mice , Humans , Seizures, Febrile/metabolism , Seizures, Febrile/genetics , Endoplasmic Reticulum-Associated Degradation , Ubiquitin-Protein Ligases/metabolism , Ubiquitin-Protein Ligases/genetics , Molecular Chaperones/metabolism , Molecular Chaperones/genetics , Mutation , HEK293 Cells , Endoplasmic Reticulum Chaperone BiP/metabolism
16.
FASEB J ; 36(6): e22312, 2022 06.
Article in English | MEDLINE | ID: mdl-35532744

ABSTRACT

Myopia is increasing worldwide and its preventable measure should urgently be pursued. N-3 polyunsaturated fatty acids (PUFAs) have been reported to have various effects such as vasodilative and anti-inflammatory, which myopia may be involved in. This study is to investigate the inhibitory effect of PUFAs on myopia progression. A lens-induced myopia (LIM) model was prepared using C57B L6/J 3-week-old mice, which were equipped with a -30 diopter lens to the right eye. Chows containing two different ratios of n-3/n-6 PUFA were administered to the mice, and myopic shifts were confirmed in choroidal thickness, refraction, and axial length in the n-3 PUFA-enriched chow group after 5 weeks. To exclude the possibility that the other ingredients in the chow may have taken the suppressive effect, fat-1 transgenic mice, which can produce n-3 PUFAs endogenously, demonstrated significant suppression of myopia. To identify what elements in n-3 PUFAs took effects on myopia suppression, enucleated eyes were used for targeted lipidomic analysis, and eicosapentaenoic acid (EPA) were characteristically distributed. Administration of EPA to the LIM model confirmed the inhibitory effect on choroidal thinning and myopia progression. Subsequently, to identify the elements and the metabolites of fatty acids effective on myopia suppression, targeted lipidomic analysis was performed and it demonstrated that metabolites of EPA were involved in myopia suppression, whereas prostaglandin E2 and 14,15-dihydrotestosterone were associated with progression of myopia. In conclusion, EPA and its metabolites are related to myopia suppression and inhibition of choroidal thinning.


Subject(s)
Fatty Acids, Omega-3 , Myopia , Animals , Choroid/metabolism , Eicosapentaenoic Acid/pharmacology , Fatty Acids, Omega-3/metabolism , Fatty Acids, Omega-3/pharmacology , Lipidomics , Mice , Mice, Transgenic , Myopia/metabolism , Myopia/prevention & control
17.
Virol J ; 20(1): 292, 2023 Dec 10.
Article in English | MEDLINE | ID: mdl-38072961

ABSTRACT

BACKGROUND: In the era of antiretroviral therapy (ART), central nervous system (CNS) complications in patients with human immunodeficiency virus (HIV) infection are sometimes associated with cerebrospinal fluid (CSF) viral escape. Here, we reported a case of persistent CNS viral escape with recurrent symptomatic encephalitis, which had ultimate stabilization achieved by a combination of ART adjustment and corticosteroids. CASE PRESENTATION: A 27-year-old man with HIV infection complained of recurrent headaches during the last year. His magnetic resonance imaging (MRI) presented diffused bilateral white matter lesions, and laboratory tests confirmed elevated CSF protein level, lymphocytic pleocytosis, and detectable CSF HIV RNA (774 copies/mL). Plasma HIV RNA was well suppressed with tenofovir, lamivudine, and lopinavir/ritonavir. Prednisone 60 mg once daily was initiated to reduce intracranial inflammation, followed by a good clinical response, with CSF HIV RNA still detectable (31.1 copies/mL). During the gradual tapering of prednisone, his headache relapsed, and booming viral loads were detected in both CSF (4580 copies/mL) and plasma (340 copies/mL) with consistent drug-resistant mutations. Thereupon, prednisone was resumed and the ART regimen was switched to zidovudine, lamivudine, and dolutegravir according to drug resistance tests. Persistent clinical recovery of symptoms, neuroimaging, and laboratory abnormalities were observed in the follow-up visits. CONCLUSION: CSF and plasma HIV RNA and further drug resistance tests should be monitored in HIV-infected patients with neurologic symptoms, as opportunistic infections or tumors can be ruled out. ART optimization using a sensitive regimen may be crucial for addressing CSF viral escape and the related encephalitis.


Subject(s)
Anti-HIV Agents , Encephalitis , HIV Infections , Adult , Humans , Male , Anti-HIV Agents/pharmacology , Cerebrospinal Fluid , Encephalitis/complications , Encephalitis/drug therapy , HIV Infections/complications , HIV Infections/drug therapy , Lamivudine/therapeutic use , Prednisone/therapeutic use , RNA , RNA, Viral/genetics , Viral Load
18.
Epilepsia ; 64(4): 1061-1073, 2023 04.
Article in English | MEDLINE | ID: mdl-36495145

ABSTRACT

OBJECTIVE: Infantile spasms is an epileptic encephalopathy of childhood, and its pathophysiology is largely unknown. We generated a heterozygous knock-in mouse with the human infantile spasms-associated de novo mutation GABRB3 (c.A328G, p.N110D) to investigate its molecular mechanisms and to establish the Gabrb3+/N110D knock-in mouse as a model of infantile spasms syndrome. METHODS: We used electroencephalography (EEG) and video monitoring to characterize seizure types, and a suite of behavioral tests to identify neurological and behavioral impairment in Gabrb3+/N110D knock-in mice. Miniature inhibitory postsynaptic currents (mIPSCs) were recorded from layer V/VI pyramidal neurons in somatosensory cortex, and extracellular multi-unit recordings from the ventral basal nucleus of the thalamus in a horizontal thalamocortical slice were used to assess spontaneous thalamocortical oscillations. RESULTS: The infantile spasms-associated human de novo mutation GABRB3 (c.A328G, p.N110D) caused epileptic spasms early in development and multiple seizure types in adult Gabrb3+/N110D knock-in mice. Signs of neurological impairment, anxiety, hyperactivity, social impairment, and deficits in spatial learning and memory were also observed. Gabrb3+/N110D mice had reduced cortical mIPSCs and increased duration of spontaneous oscillatory firing in the somatosensory thalamocortical circuit. SIGNIFICANCE: The Gabrb3+/N110D knock-in mouse has epileptic spasms, seizures, and other neurological impairments that are consistent with infantile spasms syndrome in patients. Multiple seizure types and abnormal behaviors indicative of neurological impairment both early and late in development suggest that Gabrb3+/N110D mice can be used to study the pathophysiology of infantile spasms. Reduced cortical inhibition and increased duration of thalamocortical oscillatory firing suggest perturbations in thalamocortical circuits.


Subject(s)
Spasms, Infantile , Humans , Mice , Animals , Spasms, Infantile/genetics , Receptors, GABA-A/genetics , Seizures , Pyramidal Cells , Electroencephalography , Syndrome , Spasm
19.
Inorg Chem ; 62(12): 4990-4998, 2023 Mar 27.
Article in English | MEDLINE | ID: mdl-36921355

ABSTRACT

Photochromic viologen-based materials have emerged as one of the most promising candidates for the development of X-ray light detection applications, including medical diagnosis and treatment, environmental radiation inspection, and industrial crack detection. However, the design and construction of low-dose X-ray-sensitive complexes remains an immense challenge, especially for the in-depth dissection of their response mechanisms. Herein, by using N,N'-4,4'-bipyridiniodipropionate (CV) as functional sensitive structural units and cadmium as heavy atoms, two cadmium-viologen complexes with one-dimensional chained structures, namely, [Cd2Cl4(CV)(H2O)2]n (1) and [CdBr2(CV)]n (2), have been constructed, which exhibit a remarkable and selective photochromic response to low-dose X-ray radiation detection. Compound 1 is visually sensitive to both X-ray and UV light due to the more accessible photoinduced electron transfer (ET) pathways, while compound 2 only shows a slight color-changing process in response to UV light, in conformity with UV-vis absorbance analyses and kinetic studies. Surprisingly, compound 2 has longer ET pathways than 1, but not in response to high-energy X-ray light, seeming to contradict the previous phenomena. On further analysis, the key point in achieving X-ray-sensitive behavior should be a good balance among the electron donor-acceptor distance, intermolecular interaction, and X-ray absorbing capacity, as verified by density functional theory (DFT) and X-ray absorption strength calculations, X-ray photoelectron spectra, electron paramagnetic resonance measurements, and independent gradient model analysis. In particular, compound 1 is unprecedentedly sensitive to soft X-ray radiation, accompanied by an X-ray detection limit of as low as 2.91 Gy. These findings push forward the further development of low-dose X-ray sensing materials.

20.
Environ Sci Technol ; 57(16): 6723-6732, 2023 04 25.
Article in English | MEDLINE | ID: mdl-37043741

ABSTRACT

Identifying reactive species in advanced oxidation process (AOP) is an essential and intriguing topic that is also challenging and requires continuous efforts. In this study, we exploited a novel AOP technology involving peracetic acid (PAA) activation mediated by a MnII-nitrilotriacetic acid (NTA) complex, which outperformed iron- and cobalt-based PAA activation processes for rapidly degrading phenolic and aniline contaminants from water. The proposed MnII/NTA/PAA system exhibited non-radical oxidation features and could stoichiometrically oxidize sulfoxide probes to the corresponding sulfone products. More importantly, we traced the origin of O atoms from the sulfone products by 18O isotope-tracing experiments and found that PAA was the only oxygen-donor, which is different from the oxidation process mediated by high-valence manganese-oxo intermediates. According to the results of theoretical calculations, we proposed that NTA could tune the coordination circumstance of the MnII center to elongate the O-O bond of the complexed PAA. Additionally, the NTA-MnII-PAA* molecular cluster presented a lower energy gap than the MnII-PAA complex, indicating that the MnII-peroxy complex was more reactive in the presence of NTA. Thus, the NTA-MnII-PAA* complex exhibited a stronger oxidation potential than PAA, which could rapidly oxidize organic contaminants from water. Further, we generalized our findings to the CoII/PAA oxidation process and highlighted that the CoII-PAA* complex might be the overlooked reactive cobalt species. The significance of this work lies in discovering that sometimes the metal-peroxy complex could directly oxidize the contaminants without the further generation of high-valence metal-oxo intermediates and/or radical species through interspecies oxygen and/or electron transfer.


Subject(s)
Coordination Complexes , Water Pollutants, Chemical , Peracetic Acid , Oxygen , Metals , Coordination Complexes/chemistry , Cobalt , Oxidation-Reduction , Water , Hydrogen Peroxide
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