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The development of a vaccine specific to severe acute respiratory syndrome coronavirus 2 Omicron has been hampered due to its low immunogenicity. Here, using reverse mutagenesis, we found that a phenylalanine-to-serine mutation at position 375 (F375S) in the spike protein of Omicron to revert it to the sequence found in Delta and other ancestral strains significantly enhanced the immunogenicity of Omicron vaccines. Sequence FAPFFAF at position 371-377 in Omicron spike had a potent inhibitory effect on macrophage uptake of receptor-binding domain (RBD) nanoparticles or spike-pseudovirus particles containing this sequence. Omicron RBD enhanced binding to Siglec-9 on macrophages to impair phagocytosis and antigen presentation and promote immune evasion, which could be abrogated by the F375S mutation. A bivalent F375S Omicron RBD and Delta-RBD nanoparticle vaccine elicited potent and broad nAbs in mice, rabbits and rhesus macaques. Our research suggested that manipulation of the Siglec-9 pathway could be a promising approach to enhance vaccine response.
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COVID-19 , SARS-CoV-2 , Animales , Ratones , Conejos , Anticuerpos Neutralizantes , Anticuerpos Antivirales , Macaca mulatta , Macrófagos , Nanovacunas , Fagocitosis , Lectinas Similares a la Inmunoglobulina de Unión a Ácido SiálicoRESUMEN
Although haemoglobin is a known carrier of oxygen in erythrocytes that functions to transport oxygen over a long range, its physiological roles outside erythrocytes are largely elusive1,2. Here we found that chondrocytes produced massive amounts of haemoglobin to form eosin-positive bodies in their cytoplasm. The haemoglobin body (Hedy) is a membraneless condensate characterized by phase separation. Production of haemoglobin in chondrocytes is controlled by hypoxia and is dependent on KLF1 rather than the HIF1/2α pathway. Deletion of haemoglobin in chondrocytes leads to Hedy loss along with severe hypoxia, enhanced glycolysis and extensive cell death in the centre of cartilaginous tissue, which is attributed to the loss of the Hedy-controlled oxygen supply under hypoxic conditions. These results demonstrate an extra-erythrocyte role of haemoglobin in chondrocytes, and uncover a heretofore unrecognized mechanism in which chondrocytes survive a hypoxic environment through Hedy.
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Adaptación Fisiológica , Hipoxia de la Célula , Condrocitos , Hemoglobinas , Humanos , Cartílago Articular/citología , Cartílago Articular/metabolismo , Muerte Celular , Hipoxia de la Célula/fisiología , Condrocitos/metabolismo , Citoplasma/metabolismo , Eosina Amarillenta-(YS)/metabolismo , Eritrocitos/metabolismo , Glucólisis , Hemoglobinas/deficiencia , Hemoglobinas/genética , Hemoglobinas/metabolismo , Oxígeno/metabolismoRESUMEN
Rett syndrome (RTT) is a devastating neurodevelopmental disorder primarily caused by mutations in the methyl-CpG binding protein 2 (Mecp2) gene. Here, we found that inhibition of Receptor-Interacting Serine/Threonine-Protein Kinase 1 (RIPK1) kinase ameliorated progression of motor dysfunction after onset and prolonged the survival of Mecp2-null mice. Microglia were activated early in myeloid Mecp2-deficient mice, which was inhibited upon inactivation of RIPK1 kinase. RIPK1 inhibition in Mecp2-deficient microglia reduced oxidative stress, cytokines production and induction of SLC7A11, SLC38A1, and GLS, which mediate the release of glutamate. Mecp2-deficient microglia release high levels of glutamate to impair glutamate-mediated excitatory neurotransmission and promote increased levels of GluA1 and GluA2/3 proteins in vivo, which was reduced upon RIPK1 inhibition. Thus, activation of RIPK1 kinase in Mecp2-deficient microglia may be involved both in the onset and progression of RTT.
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Síndrome de Rett , Animales , Ratones , Ácido Glutámico/metabolismo , Inflamación/genética , Inflamación/metabolismo , Proteína 2 de Unión a Metil-CpG/metabolismo , Ratones Noqueados , Microglía/metabolismo , Síndrome de Rett/metabolismoRESUMEN
BACKGROUND: Abdominal aortic aneurysm (AAA) is a catastrophic disease with little effective therapy, likely due to the limited understanding of the mechanisms underlying AAA development and progression. ATF3 (activating transcription factor 3) has been increasingly recognized as a key regulator of cardiovascular diseases. However, the role of ATF3 in AAA development and progression remains elusive. METHODS: Genome-wide RNA sequencing analysis was performed on the aorta isolated from saline or Ang II (angiotensin II)-induced AAA mice, and ATF3 was identified as the potential key gene for AAA development. To examine the role of ATF3 in AAA development, vascular smooth muscle cell-specific ATF3 knockdown or overexpressed mice by recombinant adeno-associated virus serotype 9 vectors carrying ATF3, or shRNA-ATF3 with SM22α (smooth muscle protein 22-α) promoter were used in Ang II-induced AAA mice. In human and murine vascular smooth muscle cells, gain or loss of function experiments were performed to investigate the role of ATF3 in vascular smooth muscle cell proliferation and apoptosis. RESULTS: In both Ang II-induced AAA mice and patients with AAA, the expression of ATF3 was reduced in aneurysm tissues but increased in aortic lesion tissues. The deficiency of ATF3 in vascular smooth muscle cell promoted AAA formation in Ang II-induced AAA mice. PDGFRB (platelet-derived growth factor receptor ß) was identified as the target of ATF3, which mediated vascular smooth muscle cell proliferation in response to TNF-alpha (tumor necrosis factor-α) at the early stage of AAA. ATF3 suppressed the mitochondria-dependent apoptosis at the advanced stage by upregulating its direct target BCL2. Our chromatin immunoprecipitation results also demonstrated that the recruitment of NFκB1 and P300/BAF/H3K27ac complex to the ATF3 promoter induces ATF3 transcription via enhancer activation. NFKB1 inhibitor (andrographolide) inhibits the expression of ATF3 by blocking the recruiters NFKB1 and ATF3-enhancer to the ATF3-promoter region, ultimately leading to AAA development. CONCLUSIONS: Our results demonstrate a previously unrecognized role of ATF3 in AAA development and progression, and ATF3 may serve as a novel therapeutic and prognostic marker for AAA.
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Factor de Transcripción Activador 3 , Aneurisma de la Aorta Abdominal , Músculo Liso Vascular , Miocitos del Músculo Liso , Factor de Transcripción Activador 3/genética , Factor de Transcripción Activador 3/metabolismo , Animales , Aneurisma de la Aorta Abdominal/metabolismo , Aneurisma de la Aorta Abdominal/patología , Aneurisma de la Aorta Abdominal/genética , Aneurisma de la Aorta Abdominal/inducido químicamente , Humanos , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/patología , Miocitos del Músculo Liso/metabolismo , Miocitos del Músculo Liso/patología , Ratones , Masculino , Ratones Endogámicos C57BL , Apoptosis , Células Cultivadas , Angiotensina II , Proliferación Celular , Aorta Abdominal/patología , Aorta Abdominal/metabolismo , Modelos Animales de EnfermedadRESUMEN
BACKGROUND & AIMS: Apoptosis generates plenty of membrane-bound nanovesicles, the apoptotic vesicles (apoVs), which show promise for biomedical applications. The liver serves as a significant organ for apoptotic material removal. Whether and how the liver metabolizes apoptotic vesicular products and contributes to liver health and disease is unrecognized. METHODS: apoVs were labeled and traced after intravenous infusion. Apoptosis-deficient mice by Fas mutant (Fasmut) and Caspase-3 knockout (Casp3-/-) were used with apoV replenishment to evaluate the physiological apoV function. Combinations of morphologic, biochemical, cellular, and molecular assays were applied to assess the liver while hepatocyte analysis was performed. Partial hepatectomy and acetaminophen liver failure models were established to investigate liver regeneration and disease recovery. RESULTS: We discovered that the liver is a major metabolic organ of circulatory apoVs, in which apoVs undergo endocytosis by hepatocytes via a sugar recognition system. Moreover, apoVs play an indispensable role to counteract hepatocellular injury and liver impairment in apoptosis-deficient mice upon replenishment. Surprisingly, apoVs form a chimeric organelle complex with the hepatocyte Golgi apparatus through the soluble N-ethylmaleimide-sensitive factor attachment protein receptor machinery, which preserves Golgi integrity, promotes microtubule acetylation by regulating α-tubulin N-acetyltransferase 1, and consequently facilitates hepatocyte cytokinesis for liver recovery. The assembly of the apoV-Golgi complex is further revealed to contribute to liver homeostasis, regeneration, and protection against acute liver failure. CONCLUSIONS: These findings establish a previously unrecognized functional and mechanistic framework that apoptosis through vesicular metabolism safeguards liver homeostasis and regeneration, which holds promise for hepatic disease therapeutics.
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Apoptosis , Hepatocitos , Homeostasis , Regeneración Hepática , Hígado , Ratones Noqueados , Animales , Hepatocitos/metabolismo , Hepatocitos/patología , Hígado/metabolismo , Hígado/patología , Caspasa 3/metabolismo , Ratones , Hepatectomía , Modelos Animales de Enfermedad , Receptor fas/metabolismo , Receptor fas/genética , Aparato de Golgi/metabolismo , Endocitosis , Enfermedad Hepática Inducida por Sustancias y Drogas/patología , Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Enfermedad Hepática Inducida por Sustancias y Drogas/genética , Ratones Endogámicos C57BL , Acetaminofén , MasculinoRESUMEN
The dysregulation of N6-methyladenosine (m6A) RNA modification is widely recognized for its crucial roles in various diseases, including pulmonary hypertension (PH). Prior studies have highlighted the significant role of methyltransferase-like 3 (METTL3) in the pathogenesis of PH. Nevertheless, the potential and underlying mechanisms of METTL3 and its inhibitors as targets for PH treatment require further elucidation. In this study, we observed increased levels of METTL3 in various rodent models of PH. In vitro studies revealed that METTL3 silencing or treatment with STM2457, a specific METTL3 inhibitor, attenuated the proliferation and migration of pulmonary artery smooth muscle cells stimulated by platelet-derived growth factor-BB or hypoxia. Moreover, in vivo experiments using adeno-associated virus 9-mediated METTL3 silencing or STM2457 inhibition demonstrated improvement in SU5416/hypoxia-induced PH in mice. Additionally, m6A RNA immunoprecipitation analysis identified RBPJ as a gene regulated by METTL3 in rodent models of PH. Loss-of-function studies showed that silencing RBPJ could attenuate the changes in the proliferation and migration of pulmonary artery smooth muscle cells induced by platelet-derived growth factor-BB or hypoxia. Further studies indicated that METTL3 and YTHDF1 regulate RBPJ mRNA expression in an m6A-dependent manner. These findings indicated that targeting METTL3 may be a promising therapeutic strategy for treating PH, and modulation of RBPJ could offer a potential intervention mechanism.
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Dysregulation of lipid homeostasis is a precipitating event in the pathogenesis and progression of hepatosteatosis and metabolic syndrome. These conditions are highly prevalent in developed societies and currently have limited options for diagnostic and therapeutic intervention. Here, using a proteomic and lipidomic-wide systems genetic approach, we interrogated lipid regulatory networks in 107 genetically distinct mouse strains to reveal key insights into the control and network structure of mammalian lipid metabolism. These include the identification of plasma lipid signatures that predict pathological lipid abundance in the liver of mice and humans, defining subcellular localization and functionality of lipid-related proteins, and revealing functional protein and genetic variants that are predicted to modulate lipid abundance. Trans-omic analyses using these datasets facilitated the identification and validation of PSMD9 as a previously unknown lipid regulatory protein. Collectively, our study serves as a rich resource for probing mammalian lipid metabolism and provides opportunities for the discovery of therapeutic agents and biomarkers in the setting of hepatic lipotoxicity.
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Metabolismo de los Lípidos/genética , Lípidos/análisis , Lípidos/genética , Proteómica , Animales , Células HEK293 , Humanos , Metabolismo de los Lípidos/fisiología , Lípidos/sangre , Lípidos/clasificación , Hígado/química , Hígado/metabolismo , Hígado/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos DBA , Obesidad/genética , Obesidad/metabolismo , Complejo de la Endopetidasa Proteasomal/química , Complejo de la Endopetidasa Proteasomal/genética , Complejo de la Endopetidasa Proteasomal/metabolismoRESUMEN
The microcephaly-capillary malformation (MIC-CAP) syndrome is a life-threatening disease caused by biallelic mutations of the STAMBP gene, which encodes an endosomal deubiquitinating enzyme. To establish a suitable preclinical animal model for clinical therapeutic practice, we generated a central nervous system (CNS)-specific Stambp knockout mouse model (Stambp Sox1-cKO) that phenocopies Stambp null mice including progressive microcephaly, postnatal growth retardation and complete penetrance of preweaning death. In this MIC-CAP syndrome mouse model, early-onset neuronal death occurs specifically in the hippocampus and cortex, accompanied by aggregation of ubiquitinated proteins, and massive neuroinflammation. Importantly, neonatal AAV9-mediated gene supplementation of Stambp in the brain could significantly improve neurological defects, sustain growth, and prolong the lifespan of StambpSox1-cKO mice. Together, our findings reveal a central role of brain defects in the pathogenesis of STAMBP deficiency and provide preclinical evidence that postnatal gene replacement is an effective approach to cure the disease.
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Systemic Lupus Erythematosus (SLE) is an autoimmune sickness with unclear pathogenesis. The goal of this research was to reveal the heterogeneity of immune cells in SLE patients of Han and Zang nationality by single-cell RNA sequencing (scRNA-seq) and bioinformatics profiling. METHODS: A total of 94,102 peripheral blood mononuclear cells (PBMCs) from six volunteers with SLE (3 Zang, 3 Han) and six healthy controls were first conducted through scRNA-seq analysis. The immune cell subsets in the pathogenesis of SLE were analyzed as well. Real-time quantitative PCR (RT-qPCR) was applied to confirm the results of sc-RNA seq analysis. RESULTS: For the Tibetan samples, the ratios of Naïve CD4 RPS4Y1 cells, Naïve CD4 cells, Memory BC CD24 and Memory BC differed significantly between the SLE and control samples, while that of CD8 CTL MAL cells was significantly different between the two groups in Han nationality samples. Variable differentiation states of CD8 CTL MAL cells, CD8 CTL GZMK cells, and Naïve CD4 cells were detected through pseudotime analysis. Moreover, T-cell receptor (TCR) abundance was notably higher in Tibetan SLE specimens than that in controls, while B-cell receptor (BCR) abundance in Tibetan and Han samples was higher than in control groups. CONCLUSIONS: In summary, the immune cellular heterogeneity of SLE patients both Han and Zang nationality was explored based on various bioinformatics approaches, providing new perspectives for immunological characteristics of SLE among different ethnic groups.
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Leucocitos Mononucleares , Lupus Eritematoso Sistémico , Humanos , Diferenciación Celular , Etnicidad , Lupus Eritematoso Sistémico/genética , Análisis de Secuencia de ARNRESUMEN
We report herein chemical and electrochemical ammonia oxidation (AO) catalyzed by a Ru complex, [RuII(H2L)(pic)2]2+ [1, H2L = 6,6'-di(1H-pyrazol-3-yl)-2,2'-bipyridine, pic = 4-picoline], where H2L is a tetradentate ligand with a bipyridyl unit connected to two pyrazoles. 1 functions as an efficient electrocatalyst for the oxidation of NH3 to N2, with a low overpotential of 0.51 V vs Fc+/0 and a Faradaic efficiency of 96%. 1 also undergoes catalytic chemical AO using (4-BrPh)3Nâ¢+ as an oxidant, with a turnover number for N2 reaching 41. A novel binuclear complex, [RuIII(L)(pic)2(N2)RuIII(L)(pic)2]4+ (2), was isolated and structurally characterized in the catalytic chemical AO by 1. Complex 2 possesses a zigzag dianionic µ-hexazene unit where the N2 derived from ammonia oxidation is bonded to the pyrazoles, with an NN2-NN2 bond length of 1.3091(70) Å. 2 readily releases N2 upon treating with NH3. Based on experimental and DFT studies, in chemical AO the formation of an N-N bond is proposed to occur via bimolecular coupling of a ruthenium pyrazole imido intermediate to give 2; while in electrochemical AO the N-N bond is formed by nucleophilic attack of NH3 on the intermediate.
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Mycophenolate mofetil (MMF) is one of the most used immunosuppressive drugs in organ transplantation, but frequent gastrointestinal (GI) side effects through unknown mechanisms limit its clinical use. Gut microbiota and its metabolites were recently reported to play a vital role in MMF-induced GI toxicity, but the specific mechanism of how they interact with the human body is still unclear. Here, we found that secondary bile acids (BAs), as bacterial metabolites, were significantly reduced by MMF administration in the gut of mice. Microbiome data and fecal microbiota transfer model supported a microbiota-dependent effect on the reduction of secondary BAs. Supplementation of the secondary BA lithocholic acid alleviated MMF-induced weight loss, colonic inflammation, and oxidative phosphorylation damage. Genetic deletion of the vitamin D3 receptor (VDR), which serves as a primary colonic BA receptor, in colonic epithelial cells (VDRΔIEC) abolished the therapeutic effect of lithocholic acid on MMF-induced GI toxicity. Impressively, we discovered that paricalcitol, a Food and Drug Administration-approved VDR agonist that has been used in clinics for years, could effectively alleviate MMF-induced GI toxicity. Our study reveals a previously unrecognized mechanism of gut microbiota, BAs, and VDR signaling in MMF-induced GI side effects, offering potential therapeutic strategies for clinics.
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Ácidos y Sales Biliares , Microbioma Gastrointestinal , Ácido Micofenólico , Receptores de Calcitriol , Animales , Ácido Micofenólico/farmacología , Ratones , Microbioma Gastrointestinal/efectos de los fármacos , Receptores de Calcitriol/metabolismo , Ácidos y Sales Biliares/metabolismo , Inmunosupresores , Ratones Endogámicos C57BL , Masculino , Enfermedades Gastrointestinales/inducido químicamente , Ácido Litocólico , HumanosRESUMEN
Lactobacillus is an important member of the probiotic bacterial family for regulating human intestinal microflora and preserving its normalcy, and it has been widely used in infant formula. An appropriate and feasible method to quantify viable Lactobacilli cells is urgently required to evaluate the quality of probiotic-fortified infant formula. This study presents a rapid and accurate method to count viable Lactobacilli cells in infant formula using flow cytometry (FCM). First, Lactobacillus cells were specifically and rapidly stained by oligonucleotide probes based on a signal-enhanced fluorescence in situ hybridization (SEFISH) technique. A DNA-binding fluorescent probe, propidium monoazide (PMA), was then used to accurately recognize viable Lactobacillus cells. The entire process of this newly developed PMA-SEFISH-FCM method was accomplished within 2.5 h, which included pretreatment, dual staining, and FCM analysis; thus, this method showed considerably shorter time-to-results than other rapid methods. This method also demonstrated a good linear correlation (R2 = 0.9994) with the traditional plate-based method with a bacterial recovery rate of 91.24%. To the best of our knowledge, the present study is the first report of FCM combined with PMA and FISH for the specific detection of viable bacterial cells.
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Fórmulas Infantiles , Lactobacillus , Propidio/análogos & derivados , Humanos , Lactobacillus/genética , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Citometría de Flujo/métodos , Hibridación Fluorescente in Situ , Azidas , Bacterias , Viabilidad MicrobianaRESUMEN
Phosphorus (P) is a crucial macronutrient for plant growth, development, and reproduction. The effects of low P (LP) stress on leaf senescence and the role of PHR1 in LP-induced leaf senescence are still unknown. Here, we report that PHR1 plays a crucial role in LP-induced leaf senescence, showing delayed leaf senescence in phr1 mutant and accelerated leaf senescence in 35S:PHR1 transgenic Arabidopsis under LP stress. The transcriptional profiles indicate that 763 differentially expressed SAGs (DE-SAGs) were upregulated and 134 DE-SAGs were downregulated by LP stress. Of the 405 DE-SAGs regulated by PHR1, 27 DE-SAGs were involved in P metabolism and transport. PHR1 could bind to the promoters of six DE-SAGs (RNS1, PAP17, SAG113, NPC5, PLDζ2, and Pht1;5), and modulate them in LP-induced senescing leaves. The analysis of RNA content, phospholipase activity, acid phosphatase activity, total P and phosphate content also revealed that PHR1 promotes P liberation from senescing leaves and transport to young tissues under LP stress. Our results indicated that PHR1 is one of the crucial modulators for P recycling and redistribution under LP stress, and the drastic decline of P level is at least one of the causes of early senescence in P-deficient leaves.
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Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Fósforo/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Senescencia de la Planta , Factores de Transcripción/metabolismo , Fosfatos/metabolismo , Hojas de la Planta/metabolismo , Homeostasis , Regulación de la Expresión Génica de las PlantasRESUMEN
BACKGROUND: Extrachromosomal circular DNAs (eccDNAs) have been reported to play a key role in the occurrence and development of various diseases. However, the characterization and role of eccDNAs in pulmonary arterial hypertension (PAH) remain unclear. METHODS: In the discovery cohort, we first explored eccDNA expression profiles by Circle-sequencing analysis. The candidate eccDNAs were validated by routine polymerase chain reaction (PCR), TOPO-TA cloning and Sanger sequencing. In the validation cohort, 30 patients with PAH and 10 healthy controls were recruited for qPCR amplification to detect the candidate eccDNAs. Datas at the baseline were collected, including clinical background, biochemical variables, echocardiography and hemodynamic factors. Receiver operating characteristic curve was used to investigate the diagnostic effect of the eccDNA. RESULTS: We identified a total of 21,741 eccDNAs in plasma samples of 3 IPAH patients and 3 individuals in good health, and the expression frequency, GC content, length distribution, and genome distribution of the eccDNAs were thoroughly characterized and analyzed. In the validation cohort, 687 eccDNAs were differentially expressed in patients with IPAH compared with healthy controls (screening threshold: |FC|≥2 and P < 0.05). Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that the specific eccDNAs in IPAH were significantly enriched in calcium channel activity, the mitogen-activated protein kinase pathway, and the wnt signaling pathway. Verification queue found that the expression of eccDNA-chr2:131208878-131,424,362 in PAH was considerably higher than that in healthy controls and exhibited a high level of accuracy in predicting PAH with a sensitivity of 86.67% and a specificity of 90%. Furthermore, correlation analysis disclosed a significant association between serum eccDNA-chr2:131208878-131,424,362 and mean pulmonary artery pressure (mPAP) (r = 0.396, P = 0.03), 6 min walking distance (6MWD) (r = -0.399, P = 0.029), N-terminal pro-B-type natriuretic peptide (NT-proBNP) (r = 0.685, P < 0.001) and cardiac index (CI) (r = - 0.419, P = 0.021). CONCLUSIONS: This is the first study to identify and characterize eccDNAs in patients with PAH. We revealed that serum eccDNA-chr2:131208878-131,424,362 is significantly overexpressed and can be used in the diagnosis of PAH, indicating its potential as a novel non-invasive biomarker.
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Biomarcadores , ADN Circular , Humanos , Masculino , Femenino , Persona de Mediana Edad , Adulto , Biomarcadores/sangre , ADN Circular/sangre , ADN Circular/genética , ADN Circular/análisis , Hipertensión Arterial Pulmonar/sangre , Hipertensión Arterial Pulmonar/genética , Hipertensión Arterial Pulmonar/diagnóstico , Estudios de Cohortes , Estudios de Casos y ControlesRESUMEN
Ubiquitin fold modifier 1 is a small ubiquitin-like protein modifier that is essential for embryonic development of metazoans. Although UFMylation has been connected to endoplasmic reticulum homeostasis, the underlying mechanisms and the relevant cellular targets are largely unknown. Here, we show that HRD1, a ubiquitin ligase of ER-associated protein degradation (ERAD), is a novel substrate of UFM1 conjugation. HRD1 interacts with UFMylation components UFL1 and DDRGK1 and is UFMylated at Lys610 residue. In UFL1-depleted cells, the stability of HRD1 is increased and its ubiquitination modification is reduced. In the event of ER stress, the UFMylation and ubiquitination modification of HRD1 is gradually inhibited over time. Alteration of HRD1 Lys610 residue to arginine impairs its ability to degrade unfolded or misfolded proteins to disturb protein processing in ER. These results suggest that UFMylation of HRD1 facilitates ERAD function to maintain ER homeostasis.
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Estrés del Retículo Endoplásmico , Ubiquitina-Proteína Ligasas , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismo , Estrés del Retículo Endoplásmico/fisiología , Proteínas/metabolismo , Retículo Endoplásmico/metabolismo , Ubiquitina/metabolismo , Homeostasis , Degradación Asociada con el Retículo EndoplásmicoRESUMEN
AIM: Acyl-coenzyme A dehydrogenase family member 10 (ACAD10) is a mitochondrial protein purported to be involved in the fatty acid oxidation pathway. Metformin is the most prescribed therapy for type 2 diabetes; however, its precise mechanisms of action(s) are still being uncovered. Upregulation of ACAD10 is a requirement for metformin's ability to inhibit growth in cancer cells and extend lifespan in Caenorhabditis elegans. However, it is unknown whether ACAD10 plays a role in metformin's metabolic actions. MATERIALS AND METHODS: We assessed the role for ACAD10 on whole-body metabolism and metformin action by generating ACAD10KO mice on a C57BL/6J background via CRISPR-Cas9 technology. In-depth metabolic phenotyping was conducted in both sexes on a normal chow and high fat-high sucrose diet. RESULTS: Compared with wildtype mice, we detected no difference in body composition, energy expenditure or glucose tolerance in male or female ACAD10KO mice, on a chow diet or high-fat, high-sucrose diet (p ≥ .05). Hepatic mitochondrial function and insulin signalling was not different between genotypes under basal or insulin-stimulated conditions (p ≥ .05). Glucose excursions following acute administration of metformin before a glucose tolerance test were not different between genotypes nor was body composition or energy expenditure altered after 4 weeks of daily metformin treatment (p ≥ .05). Despite the lack of a metabolic phenotype, liver lipidomic analysis suggests ACAD10 depletion influences the abundance of specific ceramide species containing very long chain fatty acids, while metformin treatment altered clusters of cholesterol ester, plasmalogen, phosphatidylcholine and ceramide species. CONCLUSIONS: Loss of ACAD10 does not alter whole-body metabolism or impact the acute or chronic metabolic actions of metformin in this model.
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Diabetes Mellitus Tipo 2 , Metformina , Masculino , Femenino , Ratones , Animales , Diabetes Mellitus Tipo 2/metabolismo , Ratones Endogámicos C57BL , Metformina/farmacología , Glucosa/metabolismo , Insulina , Ceramidas , Sacarosa , Dieta Alta en Grasa/efectos adversosRESUMEN
Ruthenium-oxo species with high coordination numbers have long been proposed as active intermediates in catalytic oxidation chemistry. By employing a tetradentate bipyridine-bipyrazole ligand, we herein reported the synthesis of a seven-coordinate (CN7) ruthenium(IV) oxo complex, [RuIV(tpz)(pic)2(O)]2+ (RuIVO) (tpz = 6,6'-di(1H-pyrazol-1-yl)-2,2'-bipyridine, pic = 4-picoline), which exhibits high activity toward the oxidation of alkylaromatic hydrocarbons. The large kinetic isotope effects (KIE) for the oxidation of DHA/DHA-d4 (KIE = 10.3 ± 0.1) and xanthene/xanthene-d2 (KIE = 17.2 ± 0.1), as well as the linear relationship between log (rate constants) and bond dissociation energies of alkylaromatics, confirmed a mechanism of hydrogen atom abstraction.
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An in-depth understanding of the immune system of endangered species is crucial for successful conservation efforts. Galectins, as members of the lectin family, play a crucial role in the fish innate immune system. Galectin-9 (Tfgal-9) was cloned from endangered species Trachidermus fasciatus, revealing a cDNA sequence of 1453 bp with an open reading frame of 900 bp encoding a protein of 299 amino acids. Tfgal-9 protein features two repeated carbohydrate-binding domains, each characterized by two conserved galactose-binding sites (H-NPR and WG-EER), and it possesses neither a signal peptide nor a transmembrane domain. The qRT-PCR analysis revealed that Tfgal-9 was widely expressed across all examined tissues, with the highest expression in the intestine, followed by the blood, heart and brain. Expression was notably up-regulated in the blood, skin, liver, stomach, and heart when challenged with LPS. Following induction by the heavy metal solution containing Cu, Pb, Cd, and Hg, the expression Tfgal-9 was dramatically induced to 32 times higher than that of the control group in the brain. The recombinant Tfgal-9 protein exhibits calcium-independent binding and agglutination of selected bacteria and yeast. Antimicrobial activity of recombinant Tfgal-9 protein against Gram positive bacteria Staphylococcus aureus was confirmed using the cylinder-plate method. In vitro antioxidant experiments showed that radical scavenging activity of DPPH was 50.38 % when Tfgal-9 concentration reached 200 µg/mL. These results indicate that Tfgal-9 may play important roles in the immune response against microbial infections and the maintaining of redox homeostasis.
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BACKGROUND: The aim was to assess the knowledge, attitudes, and practices (KAPs) of endoscopy among gastroenterologists in the diagnosis and management of IBD in China. METHODS: A multicenter cross-sectional KAP study was performed. The questionnaire was developed and improved using feedback and opinions from a team of experienced IBD specialist professors and then distributed and collected online. In addition, eight fellow gastroenterologists participated in an IBD endoscopy training program were asked to review endoscopic images, and the consistency of the endoscopic scores before and after training was calculated. RESULTS: A total of 193 participants from 12 provincial-level administrative regions encompassing both the Northern and Southern parts of China completed the study questionnaire. The median age of the participants was 40 (36, 45) years, with the majority being female (70.5%). The median professional experience as gastroenterologists was 11 (7, 17) years, while the median experience as endoscopists was 8 (3, 15) years. The median knowledge score was 8 out of 10 points for single-choice questions; however, most gastroenterologists believed that some concepts in these endoscopic indices were vague, including those regarding deep ulcerations, ulcerated surfaces, affected surfaces and narrowing in open-answer questions. The UCEIS and SES-CD were considered most consistent with clinical activity score in the evaluation of UC and CD, respectively. IBD subspecialists and gastroenterologists who had previously received IBD endoscopy screening training were more likely to use endoscopic indices (p<0.001, p = 0.029, respectively). The Rutgeerts score demonstrated the most significant improvement in consistency before and after training, from 0.407 (95% CI: 0.025-0.999) to 0.909 (95% CI: 0.530-1.000). CONCLUSIONS: We propose the elucidation of ambiguous definitions in endoscopic indices, enhancement of training, and the application of innovative technology to enhance the application of endoscopic evaluation and endoscopic indices in clinical practice.