RESUMEN
Delta-secretase, a lysosomal asparagine endopeptidase (AEP), simultaneously cleaves both APP and tau, controlling the onset of pathogenesis of Alzheimer's disease (AD). However, how this protease is post-translationally regulated remains unclear. Here we report that serine-arginine protein kinase 2 (SRPK2) phosphorylates delta-secretase and enhances its enzymatic activity. SRPK2 phosphorylates serine 226 on delta-secretase and accelerates its autocatalytic cleavage, leading to its cytoplasmic translocation and escalated enzymatic activities. Delta-secretase is highly phosphorylated in human AD brains, tightly correlated with SRPK2 activity. Overexpression of a phosphorylation mimetic (S226D) in young 3xTg mice strongly promotes APP and tau fragmentation and facilitates amyloid plaque deposits and neurofibrillary tangle (NFT) formation, resulting in cognitive impairment. Conversely, viral injection of the non-phosphorylatable mutant (S226A) into 5XFAD mice decreases APP and tau proteolytic cleavage, attenuates AD pathologies, and reverses cognitive defects. Our findings support that delta-secretase phosphorylation by SRPK2 plays a critical role in aggravating AD pathogenesis.
Asunto(s)
Enfermedad de Alzheimer/enzimología , Secretasas de la Proteína Precursora del Amiloide/metabolismo , Encéfalo/enzimología , Procesamiento Proteico-Postraduccional , Proteínas Serina-Treonina Quinasas/metabolismo , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/fisiopatología , Enfermedad de Alzheimer/psicología , Secretasas de la Proteína Precursora del Amiloide/genética , Animales , Conducta Animal , Encéfalo/patología , Encéfalo/fisiopatología , Cognición , Modelos Animales de Enfermedad , Predisposición Genética a la Enfermedad , Células HEK293 , Células HeLa , Humanos , Ratones Endogámicos C57BL , Ratones Transgénicos , Mutación , Ovillos Neurofibrilares/metabolismo , Ovillos Neurofibrilares/patología , Fenotipo , Fosforilación , Placa Amiloide , Proteínas Serina-Treonina Quinasas/genética , Transporte de Proteínas , Interferencia de ARN , Serina , Especificidad por Sustrato , Factores de Tiempo , Transfección , Proteínas tau/genética , Proteínas tau/metabolismoRESUMEN
Single-crystal semiconductor-based photocatalysts exposing unique crystallographic facets show promising applications in energy and environmental technologies; however, crystal facet engineering through solid-state synthesis for photocatalytic overall water splitting is still challenging. Herein, we develop a novel crystal facet engineering strategy through solid-state recrystallization to synthesize uniform SrTiO3 single crystals exposing tailored {111} facets. The presynthesized low-crystalline SrTiO3 precursors enable the formation of well-defined single crystals through kinetically improved crystal structure transformation during solid-state recrystallization process. By employing subtle Al3+ ions as surface morphology modulators, the crystal surface orientation can be precisely tuned to a controlled percentage of {111} facets. The photocatalytic overall water splitting activity increases with the exposure percentage of {111} facets. Owing to the outstanding crystallinity and favorable anisotropic surface structure, the SrTiO3 single crystals with 36.6% of {111} facets lead to a 3-fold enhancement of photocatalytic hydrogen evolution rates up to 1.55 mmol·h-1 in a stoichiometric ratio of 2:1 than thermodynamically stable SrTiO3 enclosed with isotropic {100} facets.
RESUMEN
Decreased hippocampal tropomyosin receptor kinase B (TrkB) level is implicated in the pathophysiology of stress-induced mood disorder and cognitive decline. However, how TrkB is modified and mediates behavioral responses to chronic stress remains largely unknown. Here the effects and mechanisms of TrkB cleavage by asparagine endopeptidase (AEP) were examined on a preclinical murine model of chronic restraint stress (CRS)-induced depression. CRS activated IL-1ß-C/EBPß-AEP pathway in mice hippocampus, accompanied by elevated TrkB 1-486 fragment generated by AEP. Specifi.c overexpression or suppression of AEP-TrkB axis in hippocampal CaMKIIα-positive cells aggravated or relieved depressive-like behaviors, respectively. Mechanistically, in addition to facilitating AMPARs internalization, TrkB 1-486 interacted with peroxisome proliferator-activated receptor-δ (PPAR-δ) and sequestered it in cytoplasm, repressing PPAR-δ-mediated transactivation and mitochondrial function. Moreover, co-administration of 7,8-dihydroxyflavone and a peptide disrupting the binding of TrkB 1-486 with PPAR-δ attenuated depression-like symptoms not only in CRS animals, but also in Alzheimer's disease and aged mice. These findings reveal a novel role for TrkB cleavage in promoting depressive-like phenotype.
Asunto(s)
Depresión , Hipocampo , Estrés Psicológico , Animales , Hipocampo/metabolismo , Ratones , Depresión/metabolismo , Masculino , Estrés Psicológico/metabolismo , Receptor trkB/metabolismo , Modelos Animales de Enfermedad , Ratones Endogámicos C57BL , Conducta Animal/fisiología , Transducción de Señal/fisiología , Enfermedad de Alzheimer/metabolismo , Glicoproteínas de Membrana/metabolismoRESUMEN
Diabetes is a risk factor for Alzheimer's disease (AD), which is also called type 3 diabetes with insulin reduction and insulin resistance in AD patient brains. However, the molecular mechanism coupling diabetes to AD onset remains incompletely understood. Here we show that inflammation, associated with obesity and diabetes elicited by high-fat diet (HFD), activates neuronal C/EBPß/AEP signaling that drives AD pathologies and cognitive disorders. HFD stimulates diabetes and insulin resistance in neuronal Thy1-C/EBPß transgenic (Tg) mice, accompanied with prominent mouse Aß accumulation and hyperphosphorylated Tau aggregation in the brain, triggering cognitive deficits. These effects are profoundly diminished when AEP is deleted from C/EBPß Tg mice. Chronic treatment with inflammatory lipopolysaccharide (LPS) facilitates AD pathologies and cognitive disorders in C/EBPß Tg but not in wild-type mice, and these deleterious effects were substantially alleviated in C/EBPß Tg/AEP -/- mice. Remarkably, the anti-inflammatory drug aspirin strongly attenuates HFD-induced diabetes and AD pathologies in neuronal C/EBPß Tg mice. Therefore, our findings demonstrate that inflammation-activated neuronal C/EBPß/AEP signaling couples diabetes to AD.
Asunto(s)
Enfermedad de Alzheimer , Diabetes Mellitus , Resistencia a la Insulina , Animales , Ratones , Enfermedad de Alzheimer/metabolismo , Dieta Alta en Grasa/efectos adversos , Resistencia a la Insulina/fisiología , Ratones Transgénicos , Inflamación/metabolismo , Encéfalo/metabolismo , Proteína beta Potenciadora de Unión a CCAAT/metabolismo , Diabetes Mellitus/metabolismo , Modelos Animales de EnfermedadRESUMEN
OBJECTIVE: We aimed to investigate levels of cytokines/chemokines and immune checkpoint molecules in patients with anti-leucine-rich glioma-inactivated 1 (LGI1) encephalitis. METHODS: The study recruited 12 patients with anti-LGI1 encephalitis and six non-inflammatory controls from the Qilu Hospital of Shandong University treated between January 2019 and December 2020. Serum levels of 30 cytokines/chemokines and 10 checkpoint molecules were measured in participants of both the groups. RESULTS: In contrast to those in the control group, 24 cytokines/chemokines and 5 immune checkpoint molecules were differentially expressed in patients with anti-LGI1 encephalitis, with 14 cytokines being upregulated and 10 being downregulated. There were 1033 enriched biological processes and 61 enriched Kyoto Encyclopedia of Genes and Genomes signaling pathways. CONCLUSION: A wide range of cytokines/chemokines and immune checkpoint molecules are implicated in immune regulation in anti-LGI1 encephalitis, indicating that they may serve as important targets in the development and treatment of the disease.
Asunto(s)
Encefalitis , Glioma , Humanos , Leucina , Citocinas , Proteínas de Punto de Control Inmunitario , Péptidos y Proteínas de Señalización Intracelular , Autoanticuerpos , QuimiocinasRESUMEN
Cell death-inducing DFF45-like effector C (CIDEC) is involved in diet-induced adipose inflammation. Whether CIDEC plays a role in diabetic vascular inflammation remains unclear. A type 2 diabetic rat model was induced by high-fat diet and low-dose streptozotocin. We evaluated its characteristics by metabolic tests, Western blot analysis of CIDEC and C1q/tumor necrosis factor-related protein-3 (CTRP3) expression, and histopathological analysis of aortic tissues. The diabetic group exhibited elevated CIDEC expression, aortic inflammation, and remodeling. To further investigate the role of CIDEC in the pathogenesis of aortic inflammation, gene silencing was used. With CIDEC gene silencing, CTRP3 expression was restored, accompanied with amelioration of insulin resistance, aortic inflammation, and remodeling in diabetic rats. Thus, the silencing of CIDEC is potent in mediating the reversal of aortic inflammation and remodeling, indicating that CIDEC may be a potential therapeutic target for vascular complications in diabetes.
Asunto(s)
Diabetes Mellitus Experimental , Resistencia a la Insulina , Animales , Muerte Celular , Diabetes Mellitus Experimental/complicaciones , Diabetes Mellitus Experimental/genética , Inflamación/genética , Proteínas/genética , Proteínas/metabolismo , RatasRESUMEN
OBJECTIVES: Although injury of myocardium after percutaneous coronary intervention (PCI) has been reported, the mechanism and effect of exogenous phosphocreatine (PCr) supplementation on the injury are yet to be elucidated. Biomarkers, such as interleukin-6 (IL-6) and variations in white blood cells for inflammation, and serum cardiac troponin I (cTnI) for myocardial injury are examined. METHODS: A total of 105 patients undergoing PCI were included and randomly divided into two groups: control (treated with routine hydration therapy) and PCr (treated with additional intravenous infusion of exogenous PCr). The serum levels of biomarkers were detected at administration and 4, 12, 24, and 48 h after PCI, with natural logarithmic (loge) transformation of data when modeling assumptions were not fulfilled. RESULTS: The level of loge-transformed IL-6 increased in both groups, especially at 12 and 24 h after the operation, and that of PCr group was less than the control group at 48 h. The content of loge-transformed cTnI was significantly increased in both groups, while that of the PCr group was markedly lower than the control group at all time points after PCI. Moreover, the ratio of neutrophils was elevated at all time points after PCI, while that of the PCr group was lower at 48 h, and the variations in the ratio of lymphocytes showed opposite results. CONCLUSIONS: Exogenous phosphocreatine reduces stent implantation, triggers inflammation manifested as decreased serum levels of IL-6 and the aggregation of neutrophils, and protects the myocardium of the patients undergoing PCI. These findings provided the potential mechanism and treatment for myocardial injury associated with PCI.
Asunto(s)
Inflamación , Intervención Coronaria Percutánea , Fosfocreatina , Biomarcadores , Humanos , Inflamación/prevención & control , Interleucina-6 , Miocardio , Intervención Coronaria Percutánea/efectos adversos , Fosfocreatina/uso terapéutico , Troponina IRESUMEN
Cell death-inducing DFFA-like effector C (CIDEC) is responsible for metabolic disturbance and insulin resistance, which are considered to be important triggers in the development of diabetic cardiomyopathy (DCM). To investigate whether CIDEC plays a critical role in DCM, DCM rat model was induced by a high-fat diet and a single injection of low-dose streptozotocin (27.5 mg/kg). DCM rats showed severe metabolic disturbance, insulin resistance, myocardial hypertrophy, interstitial fibrosis, ectopic lipid deposition, inflammation and cardiac dysfunction, accompanied by CIDEC elevation. With CIDEC gene silencing, the above pathophysiological characteristics were significantly ameliorated accompanied by significant improvements in cardiac function in DCM rats. Enhanced AMP-activated protein kinase (AMPK) α activation was involved in the underlying pathophysiological molecular mechanisms. To further explore the underlying mechanisms that CIDEC facilitated collagen syntheses in vitro, insulin-resistant cardiac fibroblast (CF) model was induced by high glucose (15.5 mmol/L) and high insulin (104 µU/mL). We observed that insulin-resistant stimulation dramatically raised CIDEC expression and promoted CIDEC nuclear translocation in CFs. Meanwhile, AMPKα2 was observed to distribute almost completely inside CF nucleus. The results further proved that CIDEC biochemically interacted and co-localized with AMPKα2 rather than AMPKα1 in CF nucleus, which provided a novel mechanism of CIDEC in promoting collagen syntheses. This study suggested that CIDEC gene silencing alleviates DCM via AMPKα signaling both in vivo and in vitro, implicating CIDEC may be a promising target for treatment of human DCM.
Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Diabetes Mellitus Experimental/complicaciones , Diabetes Mellitus Tipo 2/complicaciones , Cardiomiopatías Diabéticas/prevención & control , Regulación de la Expresión Génica , Silenciador del Gen , Proteínas/antagonistas & inhibidores , Animales , Cardiomiopatías Diabéticas/etiología , Cardiomiopatías Diabéticas/metabolismo , Cardiomiopatías Diabéticas/patología , Resistencia a la Insulina , Masculino , Fosforilación , Proteínas/genética , Proteínas/metabolismo , Ratas , Ratas Sprague-DawleyRESUMEN
Neurotrophins promote neuronal survival and synaptic plasticity via activating the tropomyosin receptor kinases. BDNF and its high-affinity receptor TrkB are reduced in Alzheimer's disease (AD), contributing to progressive cognitive decline. However, how the signaling mediates AD pathologies remains incompletely understood. Here we show that the TrkB receptor binds and phosphorylates APP, reducing amyloid-ß production, which are abrogated by δ-secretase cleavage of TrkB in AD. Remarkably, BDNF stimulates TrkB to phosphorylate APP Y687 residue that accumulates APP in the TGN (Trans-Golgi Network) and diminishes its amyloidogenic cleavage. Delta-secretase cleaves TrkB at N365 and N486/489 residues and abolishes its neurotrophic activity, decreasing p-APP Y687 and altering its subcellular trafficking. Notably, both TrkB and APP are robustly cleaved by δ-secretase in AD brains, accompanied by mitigated TrkB signaling and reduced p-Y687. Blockade of TrkB cleavage attenuates AD pathologies in 5xFAD mice, rescuing the learning and memory. Viral expression of TrkB 1-486 fragment in the hippocampus of APP/PS1 mice facilitates amyloid pathology and mitigates cognitive functions. Hence, δ-secretase cleaves TrkB and blunts its phosphorylation of APP, facilitating AD pathogenesis.
Asunto(s)
Enfermedad de Alzheimer , Secretasas de la Proteína Precursora del Amiloide/metabolismo , Péptidos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animales , Glicoproteínas de Membrana , Ratones , Fosforilación , Proteínas Tirosina Quinasas , Receptor trkB/metabolismoRESUMEN
The apolipoprotein E ε4 (APOE4) allele is a major genetic risk factor for Alzheimer's disease (AD), and its protein product, ApoE4, exerts its deleterious effects mainly by influencing amyloid-ß (Aß) and Tau (neurofibrillary tangles, NFTs) deposition in the brain. However, the molecular mechanism dictating its expression during ageing and in AD remains incompletely clear. Here we show that C/EBPß acts as a pivotal transcription factor for APOE and mediates its mRNA levels in an age-dependent manner. C/EBPß binds the promoter of APOE and escalates its expression in the brain. Knockout of C/EBPß in AD mouse models diminishes ApoE expression and Aß pathologies, whereas overexpression of C/EBPß accelerates AD pathologies, which can be attenuated by anti-ApoE monoclonal antibody or deletion of ApoE via its specific shRNA. Remarkably, C/EBPß selectively promotes more ApoE4 expression versus ApoE3 in human neurons, correlating with higher activation of C/EBPß in human AD brains with ApoE4/4 compared to ApoE3/3. Therefore, our data support that C/EBPß is a crucial transcription factor for temporally regulating APOE gene expression, modulating ApoE4's role in AD pathogenesis.
Asunto(s)
Enfermedad de Alzheimer , Apolipoproteína E4 , Enfermedad de Alzheimer/genética , Péptidos beta-Amiloides/metabolismo , Animales , Apolipoproteína E4/genética , Apolipoproteínas E , Encéfalo/metabolismo , Proteína beta Potenciadora de Unión a CCAAT/genética , Ratones , Ratones NoqueadosRESUMEN
δ-Secretase, an age-dependent asparagine protease, cleaves both amyloid precursor protein (APP) and Tau and is required for amyloid plaque and neurofibrillary tangle pathologies in Alzheimer's disease (AD). However, whether δ-secretase activation is sufficient to trigger AD pathogenesis remains unknown. Here we show that the fragments of δ-secretase-cleavage, APP (586-695) and Tau(1-368), additively drive AD pathogenesis and cognitive dysfunctions. Tau(1-368) strongly augments BACE1 expression and Aß generation in the presence of APP. The Tau(1-368) fragment is more robust than full-length Tau in binding active STAT1, a BACE1 transcription factor, and promotes its nuclear translocation, upregulating BACE1 and Aß production. Notably, Aß-activated SGK1 or JAK2 kinase phosphorylates STAT1 and induces its association with Tau(1-368). Inhibition of these kinases diminishes stimulatory effect of Tau(1-368). Knockout of STAT1 abolishes AD pathologies induced by δ-secretase-generated APP and Tau fragments. Thus, we show that Tau may not only be a downstream effector of Aß in the amyloid hypothesis, but also act as a driving force for Aß, when cleaved by δ-secretase.
Asunto(s)
Enfermedad de Alzheimer , Secretasas de la Proteína Precursora del Amiloide , Enfermedad de Alzheimer/genética , Secretasas de la Proteína Precursora del Amiloide/genética , Secretasas de la Proteína Precursora del Amiloide/metabolismo , Péptidos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Ácido Aspártico Endopeptidasas/genética , Ácido Aspártico Endopeptidasas/metabolismo , Humanos , Ovillos Neurofibrilares , Factor de Transcripción STAT1 , Proteínas tau/metabolismoRESUMEN
Respiratory chain complex I deficiency elicits mitochondrial dysfunction and reactive oxidative species (ROS), which plays a crucial role in Parkinson's disease (PD) pathogenesis. However, it remains unclear whether the impairment in other complexes in the mitochondrial oxidative phosphorylation chain is also sufficient to trigger PD onset. Here we show that inhibition of Complex II or III in the electron transport chain (ETC) induces the motor disorder and PD pathologies in neuronal Thy1-C/EBPß transgenic mice. Through a cell-based screening of mitochondrial respiratory chain inhibitors, we identified TTFA (complex II inhibitor) and Atovaquone (complex III inhibitor), which robustly block the oxidative phosphorylation functions, strongly escalate ROS, and activate C/EBPß/AEP pathway that triggers dopaminergic neuronal cell death. Oral administration of these inhibitors to Thy1-C/EBPß mice elicits constipation and motor defects, associated with Lewy body-like inclusions. Deletion of SDHD (Succinate dehydrogenase) gene from the complex II in the Substantia Nigra of Thy1-C/EBPß mice triggers ROS and PD pathologies, resulting in motor disorders. Hence, our findings demonstrate that mitochondrial ETC inactivation triggers PD pathogenesis via activating C/EBPß/AEP pathway.
Asunto(s)
Enfermedad de Parkinson , Animales , Neuronas Dopaminérgicas/metabolismo , Ratones , Ratones Transgénicos , Mitocondrias/metabolismo , Estrés Oxidativo/fisiología , Enfermedad de Parkinson/metabolismo , Sustancia Negra/metabolismo , Sustancia Negra/patologíaRESUMEN
OBJECTIVE: Sepsis-associated encephalopathy (SAE) is a severe and common complication of sepsis and can induce cognitive dysfunction and apoptosis of neurons and neuroinflammation. Emodin has been confirmed to have anti-inflammatory effects. Thus, we sought to investigate the role of Emodin in SAE. METHODS: The cecal ligation and puncture (CLP) method was used for the establishment of SAE in mice model. For treatment of Emodin, intraperitoneal injection of 20 mg/kg Emodin was performed before the surgery. The Morris water maze and open field tests were carried for measurement of cognitive dysfunction. Hematoxylin and eosin staining was for histological analysis of hippocampus. Cell apoptosis of hippocampus neurons was measured by TUNEL staining. Pro-inflammatory and anti-inflammatory cytokines in hippocampus tissue homogenate were evaluated by ELISA. BDNF/TrkB signaling-related proteins (TrkB, p-TrkB, and BDNF), autophagy-related proteins (LC3 II/I and Beclin-1), and apoptosis-related proteins (Bax, Bcl-2, and cleaved caspase-3) were detected by Western blotting. RESULTS: Emodin significantly inhibited apoptosis and induced autophagy in hippocampal neurons of CLP-treated mice. In addition, Emodin significantly ameliorated CLP-induced cognitive dysfunction and pathological injury in mice. Meanwhile, Emodin notably inhibited CLP-induced inflammatory responses in mice via upregulation of BDNF/TrkB signaling, while the effect of Emodin was partially reversed in the presence of K252a (BDNF/TrkB signaling inhibitor). CONCLUSION: Emodin significantly inhibited the progression of SAE via mediation of BDNF/TrkB signaling. Thus, Emodin might serve as a new agent for SAE treatment.
Asunto(s)
Emodina , Encefalopatía Asociada a la Sepsis , Animales , Apoptosis , Autofagia/fisiología , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Factor Neurotrófico Derivado del Encéfalo/farmacología , Emodina/metabolismo , Emodina/farmacología , Hipocampo/metabolismo , Humanos , Ratones , Ratones Endogámicos C57BL , Receptor trkB/metabolismo , Encefalopatía Asociada a la Sepsis/tratamiento farmacológico , Encefalopatía Asociada a la Sepsis/metabolismoRESUMEN
Amyloid-ß precursor protein (APP) is sequentially cleaved by secretases and generates amyloid-ß, the major components in senile plaques in Alzheimer's disease. APP is upregulated in human Alzheimer's disease brains. However, the molecular mechanism of how APP contributes to Alzheimer's disease pathogenesis remains incompletely understood. Here we show that truncated APP C586-695 fragment generated by δ-secretase directly binds to CCAAT/enhancer-binding protein beta (CEBPB), an inflammatory transcription factor, and enhances its transcriptional activity, escalating Alzheimer's disease-related gene expression and pathogenesis. The APP C586-695 fragment, but not full-length APP, strongly associates with CEBPB and elicits its nuclear translocation and augments the transcriptional activities on APP itself, MAPT (microtubule-associated protein tau), δ-secretase and inflammatory cytokine mRNA expression, finally triggering Alzheimer's disease pathology and cognitive disorder in a viral overexpression mouse model. Blockade of δ-secretase cleavage of APP by mutating the cleavage sites reduces its stimulatory effect on CEBPB, alleviating amyloid pathology and cognitive dysfunctions. Clearance of APP C586-695 from 5xFAD mice by antibody administration mitigates Alzheimer's disease pathologies and restores cognitive functions. Thus, in addition to the sequestration of amyloid-ß, APP implicates in Alzheimer's disease pathology by activating CEBPB upon δ-secretase cleavage.
Asunto(s)
Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/patología , Precursor de Proteína beta-Amiloide/metabolismo , Proteína beta Potenciadora de Unión a CCAAT/metabolismo , Regulación de la Expresión Génica/fisiología , Anciano , Animales , Cisteína Endopeptidasas/metabolismo , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Persona de Mediana EdadRESUMEN
BACKGROUND/AIMS: Renal calculi represent a prevalent disorder associated with mineral deposition in renal calyces and the pelvis. Aberrant microRNA (miRNA) expression is implicated in renal injury. This study investigated the mechanism of miR-141-3p in calcium oxalate (CaOx) crystal-induced renal tubular epithelial cell (RTEC) injury. METHODS: Human RTECs HK-2 cells were treated with CaOx crystals to induce RTEC injury. Cell viability was evaluated using Cell Counting Kit-8 assay, and apoptosis was measured using flow cytometry. The contents of lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD), interleukin (IL)-1ß, and IL-18 were measured using enzyme-linked immunosorbent assay kits. The expressions of NLRP3, cleaved caspase-1, and GSDMD-N were detected using Western blot. miR-141-3p and NLRP3 expressions were determined using reverse transcription quantitative polymerase chain reaction. The binding of miR-141-3p and NLRP3 was validated using a dual-luciferase assay. The role of NLRP3 in the protection of miR-141-3p on RTEC injury was verified using functional rescue experiments. RESULTS: CaOx crystals induced RTEC injury, manifested as attenuated cell viability, enhanced apoptosis, elevated intracellular LDH and MDA levels, and decreased SOD level. Pyroptosis of RTECs was enhanced by CaOx crystal induction, evidenced by elevated expressions of cleaved caspase-1, GSDMD-N, IL-1ß, and IL-18. miR-141-3p expression was reduced in CaOx crystal-induced RTECs. miR-141-3p overexpression alleviated CaOx crystal-induced RTEC injury and suppressed pyroptosis of RTECs. miR-141-3p bound to NLRP3 and thereby repressed NLRP3 expression. NLRP3 overexpression reversed the protective effect of miR-141-3p overexpression on RTECs. CONCLUSION: miR-141-3p repressed NLRP3-mediated pyroptosis by suppressing NLRP3 expression, thus protecting CaOx crystal-induced RTEC injury.
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Oxalato de Calcio , Cálculos Renales , MicroARNs , Proteína con Dominio Pirina 3 de la Familia NLR , Oxalato de Calcio/metabolismo , Caspasa 1/metabolismo , Células Epiteliales/metabolismo , Células Epiteliales/patología , Humanos , Interleucina-18/metabolismo , Cálculos Renales/metabolismo , Cálculos Renales/patología , Masculino , MicroARNs/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Piroptosis , Superóxido Dismutasa/metabolismoRESUMEN
BACKGROUND: Venous thromboembolism (VTE) is a major global health problem with high incidence and mortality. Vein endothelial cell (VEC) dysfunction is the primary cause of VTE. MicroRNAs (miRNAs) assist in the regulation of VEC functional pathways. Our objective was to identify potential miRNA target genes associated with VTE. MATERIALS AND METHODS: To explore the association between mRNAs and miRNAs in VTE, we performed an mRNA or miRNA microarray analysis and experiments in vitro. In addition, five online bioinformatics tools identified the target genes of differentially expressed miRNAs, and a miRNA-gene network was constructed. As a result, hub miRNA and mRNA were confirmed. Finally, wound healing assay and transwell migration assay were performed to elucidate the effect of hub miRNA in VEC. Luciferase reporter assay and real-time quantitative polymerase chain reaction (RT-qPCR) were performed to decide the role of miRNA in the expression of hub mRNA. RESULTS: Screening identified eight overlapping dysregulated genes in patients with VTE, three of which demonstrated a significantly decreased expression of miR-200a-5p. Low expression miR-200a-5p in VTE patients is confirmed by a receiver operating characteristic analysis (AUC = 0.800, P = 0.023) and binary logistic regression (OR = 0.359, 95% confidence interval: 0.605-0.995). RT-qPCR results showed that the miR-200a-5p level was decreased in hypoxia VEC (P = 0.038). MiR-200a-5p significantly promoted the migration ability of VEC. The result of Dual-luciferase reporter assay showed that cytochrome coxidase â ¦c (COX7C) directly inhibit the miR-200a-5p expression by binding 5'UTR of miR-200a-5p (P = 0.011). CONCLUSIONS: We anticipate that the miR-200a-5p-COX7C pair might be involved in the progression of VTE. Moreover, miR-200a-5p might be a therapeutic target for VTE.
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MicroARNs/genética , Tromboembolia Venosa , Biomarcadores , Biología Computacional , Humanos , MicroARNs/metabolismo , ARN Mensajero , Resultado del Tratamiento , Tromboembolia Venosa/diagnóstico , Tromboembolia Venosa/genéticaRESUMEN
BDNF, an essential trophic factor implicated in synaptic plasticity and neuronal survival, is reduced in Alzheimer's disease (AD). BDNF deficiency's association with Tau pathology in AD is well documented. However, the molecular mechanisms accounting for these events remain incompletely understood. Here we show that BDNF deprivation triggers Tau proteolytic cleavage by activating δ-secretase [i.e., asparagine endopeptidase (AEP)], and the resultant Tau N368 fragment binds TrkB receptors and blocks its neurotrophic signals, inducing neuronal cell death. Knockout of BDNF or TrkB receptors provokes δ-secretase activation via reducing T322 phosphorylation by Akt and subsequent Tau N368 cleavage, inducing AD-like pathology and cognitive dysfunction, which can be restored by expression of uncleavable Tau N255A/N368A mutant. Blocking the Tau N368-TrkB complex using Tau repeat-domain 1 peptide reverses this pathology. Thus, our findings support that BDNF reduction mediates Tau pathology via activating δ-secretase in AD.
Asunto(s)
Secretasas de la Proteína Precursora del Amiloide/metabolismo , Receptor trkB/antagonistas & inhibidores , Proteínas tau/metabolismo , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/fisiopatología , Péptidos beta-Amiloides/metabolismo , Animales , Encéfalo/metabolismo , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Línea Celular , Cognición/fisiología , Disfunción Cognitiva/metabolismo , Cisteína Endopeptidasas/metabolismo , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Ovillos Neurofibrilares/metabolismo , Neuronas/metabolismo , Fosforilación , Cultivo Primario de Células , Proteínas Proto-Oncogénicas c-akt/metabolismo , Receptor trkB/metabolismo , Transducción de SeñalRESUMEN
OBJECTIVES: To explore the influencing factors of the horizontal distance of bodies in the high falling scene and the feasibility of inferring the falling mode based on it. METHODS: A total of 614 high falling deaths and 15 cases of corpse dumping from high altitudes were collected. The relationship between the horizontal distance and the falling height, as well as the sex, age and manner of death (suicide, accident and corpse dumping) were observed. RESULTS: The horizontal distance increased with the increase of falling height, and the difference among the height groups was statistically significant. The horizontal distance decreased with the increase of the age of the deceased, in each height group, the difference between the group over 60 years old and other age groups was statistically significant (P<0.05). The horizontal distance of male deceased was (1.99±0.27) m, which was greater than that of female deceased (1.88±0.19) m, and the difference was statistically significant in partial height groups (P<0.05). Roof falls had a greater horizontal movement distance than window falls. Except for the >20-30 m group, there was no significant difference in horizontal distance between suicide high falls and accidental high falls in other height groups. CONCLUSIONS: The horizontal distance is affected by the falling height, the sex and age of the victim, and the spatial characteristics of the falling starting point.
Asunto(s)
Homicidio , Suicidio , Estatura , Cadáver , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
The oxidative metabolism of dopamine and consequent oxidative stress are implicated in dopaminergic neuronal loss, mediating the pathogenesis of Parkinson's disease (PD). The inducible detoxifying antioxidative enzyme Quinone oxidoreductase (NQO1) (NAD(P)H: quinone oxidoreductase 1), neuroprotective to counteract reactive oxidative species, is most prominent in the active stage of the disease and virtually absent at the end stage of the disease. However, the molecular mechanism dictating NQO1 expression oscillation remains unclear. Here we show that Akt phosphorylates NQO1 at T128 residues and triggers its polyubiquitination and proteasomal degradation, abrogating its antioxidative effects in PD. Akt binds NQO1 in a phosphorylation-dependent manner. Interestingly, Akt, but not PINK1, provokes NQO1 phosphorylation and polyubiquitination with Parkin as an E3 ligase. Unphosphorylatable NQO1 mutant displays more robust neuroprotective activity than WT NQO1 in suppressing reactive oxidative species and against MPTP-induced dopaminergic cell death, rescuing the motor disorders in both α-synuclein transgenic transgenic male and female mice elicited by the neurotoxin. Thus, our findings demonstrate that blockade of Akt-mediated NQO1 degradation may ameliorate PD pathogenesis.SIGNIFICANCE STATEMENT Dopaminergic neurodegeneration in Parkinson's disease (PD) is associated with the imbalance of oxidative metabolism of dopamine. Quinone oxidoreductase (NQO1), a potent antioxidant system, its expression levels are prominently increased in the early and intermediate stages of PD and disappeared in the end-stage PD. The molecular modification behavior of NQO1 after it is upregulated by oxidative stress in the early stage of PD, however, remains unclear. This study shows that Akt binds and phosphorylates NQO1 at T128 residue and promotes its ubiquitination and degradation, and Parkin acts as an E3 ligase in this process, which affects the antioxidant capacity of NQO1. This finding provides a novel molecular mechanism for NQO1 oscillation in PD pathogenesis.
Asunto(s)
Antioxidantes/metabolismo , NAD(P)H Deshidrogenasa (Quinona)/metabolismo , Estrés Oxidativo/fisiología , Trastornos Parkinsonianos/metabolismo , Proteolisis , Proteínas Proto-Oncogénicas c-akt/metabolismo , Animales , Línea Celular Tumoral , Células HEK293 , Humanos , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , NAD(P)H Deshidrogenasa (Quinona)/genética , Trastornos Parkinsonianos/genética , Fosforilación/fisiologíaRESUMEN
The mechanisms responsible for platelet activation, the prothrombotic state, in non-valvular atrial fibrillation (NVAF) are still obscure. Microvesicles (MVs) can transfer various messages to target cells and may be helpful for exploring the detailed mechanisms. We aimed to investigate the possible mechanisms by which proatherogenic factors of NVAF contribute to platelet activation. Two hundred and ten patients with NVAF were stratified as being at 'low to moderate risk' or 'high risk' for stroke according to the CHADS2 score. Levels of platelet-derived MVs (PMVs) and platelet activation were examined. CD36-positive or CD36-deficient human platelets were stimulated by MVs isolated from NVAF patients with or without various inhibitors in vitro. Levels of PMVs and platelet activation markers enhanced significantly in high-risk patients. The MVs isolated from plasma of NVAF patients bound to platelet CD36 and activated platelets by phosphorylating the mitogen-activated protein kinase 4/Jun N-terminal kinase 2 (MKK4/JNK2) pathways. However, CD36 deficiency protected against MV-induced activation of platelets. We reveal a possible mechanism of platelet activation in NVAF and suggest that the platelet CD36 might be an effective target in preventing the prothrombotic state in NVAF.