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Horizontal gene transfer is a key driver of bacterial evolution, but it also presents severe risks to bacteria by introducing invasive mobile genetic elements. To counter these threats, bacteria have developed various defense systems, including prokaryotic Argonautes (pAgos) and the DNA defense module DdmDE system. Through biochemical analysis, structural determination, and in vivo plasmid clearance assays, we elucidate the assembly and activation mechanisms of DdmDE, which eliminates small, multicopy plasmids. We demonstrate that DdmE, a pAgo-like protein, acts as a catalytically inactive, DNA-guided, DNA-targeting defense module. In the presence of guide DNA, DdmE targets plasmids and recruits a dimeric DdmD, which contains nuclease and helicase domains. Upon binding to DNA substrates, DdmD transitions from an autoinhibited dimer to an active monomer, which then translocates along and cleaves the plasmids. Together, our findings reveal the intricate mechanisms underlying DdmDE-mediated plasmid clearance, offering fundamental insights into bacterial defense systems against plasmid invasions.
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Horizontal gene transfer is a key driver of bacterial evolution, but it also presents severe risks to bacteria by introducing invasive mobile genetic elements. To counter these threats, bacteria have developed various defense systems, including prokaryotic Argonautes (pAgo) and the D NA D efense M odule DdmDE system. Through biochemical analysis, structural determination, and in vivo plasmid clearance assays, we elucidate the assembly and activation mechanisms of DdmDE, which eliminates small, multicopy plasmids. We demonstrate that DdmE, a pAgo-like protein, acts as a catalytically inactive, DNA-guided, DNA-targeting defense module. In the presence of guide DNA, DdmE targets plasmids and recruits a dimeric DdmD, which contains nuclease and helicase domains. Upon binding to DNA substrates, DdmD transitions from an autoinhibited dimer to an active monomer, which then translocates along and cleaves the plasmids. Together, our findings reveal the intricate mechanisms underlying DdmDE-mediated plasmid clearance, offering fundamental insights into bacterial defense systems against plasmid invasions.
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As one of the most prevalent anti-phage defense systems in prokaryotes, Gabija consists of a Gabija protein A (GajA) and a Gabija protein B (GajB). The assembly and function of the Gabija system remain unclear. Here we present cryo-EM structures of Bacillus cereus GajA and GajAB complex, revealing tetrameric and octameric assemblies, respectively. In the center of the complex, GajA assembles into a tetramer, which recruits two sets of GajB dimer at opposite sides of the complex, resulting in a 4:4 GajAB supramolecular complex for anti-phage defense. Further biochemical analysis showed that GajA alone is sufficient to cut double-stranded DNA and plasmid DNA, which can be inhibited by ATP. Unexpectedly, the GajAB displays enhanced activity for plasmid DNA, suggesting a role of substrate selection by GajB. Together, our study defines a framework for understanding anti-phage immune defense by the GajAB complex.
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Bacillus cereus , Proteínas de Bactérias , Microscopia Crioeletrônica , Modelos Moleculares , Bacillus cereus/virologia , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Multimerização Proteica , Plasmídeos/metabolismo , Plasmídeos/química , Trifosfato de Adenosina/metabolismo , Trifosfato de Adenosina/químicaRESUMO
Escherichia coli Septu system, an anti-phage defense system, comprises two components: PtuA and PtuB. PtuA contains an ATPase domain, while PtuB is predicted to function as a nuclease. Here we show that PtuA and PtuB form a stable complex with a 6:2 stoichiometry. Cryo-electron microscopy structure of PtuAB reveals a distinctive horseshoe-like configuration. PtuA adopts a hexameric arrangement, organized as an asymmetric trimer of dimers, contrasting the ring-like structure by other ATPases. Notably, the three pairs of PtuA dimers assume distinct conformations and fulfill unique roles in recruiting PtuB. Our functional assays have further illuminated the importance of the oligomeric assembly of PtuAB in anti-phage defense. Moreover, we have uncovered that ATP molecules can directly bind to PtuA and inhibit the activities of PtuAB. Together, the assembly and function of the Septu system shed light on understanding other ATPase-containing systems in bacterial immunity.
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Bacteriófagos , Inflamassomos , Microscopia Crioeletrônica , Bacteriófagos/metabolismo , Adenosina Trifosfatases/metabolismo , Escherichia coli/metabolismoRESUMO
BACKGROUND: As an innovative treatment, stapled transperineal rectovaginal fistula repair (STR) for rectovaginal fistula (RVF) has demonstrated effectiveness in preliminary reports. This study aims to compare STR with rectal mucosal advancement flap repair (RAF), a widely utilized surgical procedure, for the surgical outcome of the low- and mid-level RVF. METHODS: In this retrospective cohort study, patients with low- and mid-level RVF who underwent STR or RAF were included from both the Sixth Affiliated Hospital of Sun Yat-sen University and Xi'an Daxing Hospital. Among the 99 total patients, 77 underwent STR and 22 underwent RAF. Patient demographics, operative data, and outcomes were collected and analyzed. Recurrence rate and associated risk factors were evaluated. RESULTS: There were no statistically significant differences among patients in terms of clinical characteristics like age, BMI, aetiology, and fistula features. During the follow-up period of 20 months (interquartile range 3.0-41.8 months), a total of 28 patients relapsed, with a significantly lower recurrence rate in the STR group (20.8 %) than in the RAF group (54.6 %) (P = 0.005). In the multivariate Cox analysis, STR was an independent protective factor against recurrence (HR: 0.37, 95%CI: 0.17-0.79, P = 0.01). Logistic regression indicated that there was no statistically significant difference between these two procedures in terms of surgical complications (OR: 0.53, 95%CI: 0.19-1.48, P = 0.23). CONCLUSION: For low- and mid-level RVF, STR may be an alternative option for treatment modality that offers a lower recurrence rate, without observed disadvantage in terms of surgical complication rates.
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Fístula Retovaginal , Reto , Feminino , Humanos , Fístula Retovaginal/etiologia , Fístula Retovaginal/cirurgia , Estudos Retrospectivos , Reto/cirurgia , Retalhos Cirúrgicos , Fatores de Risco , Resultado do TratamentoRESUMO
SIR2-HerA, a bacterial two-protein anti-phage defense system, induces bacterial death by depleting NAD+ upon phage infection. Biochemical reconstitution of SIR2, HerA, and the SIR2-HerA complex reveals a dynamic assembly process. Unlike other ATPases, HerA can form various oligomers, ranging from dimers to nonamers. When assembled with SIR2, HerA forms a hexamer and converts SIR2 from a nuclease to an NAD+ hydrolase, representing an unexpected regulatory mechanism mediated by protein assembly. Furthermore, high concentrations of ATP can inhibit NAD+ hydrolysis by the SIR2-HerA complex. Cryo-EM structures of the SIR2-HerA complex reveal a giant supramolecular assembly up to 1 MDa, with SIR2 as a dodecamer and HerA as a hexamer, crucial for anti-phage defense. Unexpectedly, the HerA hexamer resembles a spiral staircase and exhibits helicase activities toward dual-forked DNA. Together, we reveal the supramolecular assembly of SIR2-HerA as a unique mechanism for switching enzymatic activities and bolstering anti-phage defense strategies.
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Proteínas de Escherichia coli , Escherichia coli , Sirtuínas , Fagos T , Adenosina Trifosfatases/genética , Proteínas de Bactérias/genética , NAD , Sirtuínas/metabolismo , Escherichia coli/enzimologia , Escherichia coli/virologia , Proteínas de Escherichia coli/metabolismoRESUMO
Although eukaryotic and long prokaryotic Argonaute proteins (pAgos) cleave nucleic acids, some short pAgos lack nuclease activity and hydrolyse NAD(P)+ to induce bacterial cell death1. Here we present a hierarchical activation pathway for SPARTA, a short pAgo consisting of an Argonaute (Ago) protein and TIR-APAZ, an associated protein2. SPARTA progresses through distinct oligomeric forms, including a monomeric apo state, a monomeric RNA-DNA-bound state, two dimeric RNA-DNA-bound states and a tetrameric RNA-DNA-bound active state. These snapshots together identify oligomerization as a mechanistic principle of SPARTA activation. The RNA-DNA-binding channel of apo inactive SPARTA is occupied by an auto-inhibitory motif in TIR-APAZ. After the binding of RNA-DNA, SPARTA transitions from a monomer to a symmetric dimer and then an asymmetric dimer, in which two TIR domains interact through charge and shape complementarity. Next, two dimers assemble into a tetramer with a central TIR cluster responsible for hydrolysing NAD(P)+. In addition, we observe unique features of interactions between SPARTA and RNA-DNA, including competition between the DNA 3' end and the auto-inhibitory motif, interactions between the RNA G2 nucleotide and Ago, and splaying of the RNA-DNA duplex by two loops exclusive to short pAgos. Together, our findings provide a mechanistic basis for the activation of short pAgos, a large section of the Ago superfamily.
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Proteínas Argonautas , Células Procarióticas , Apoproteínas/química , Apoproteínas/metabolismo , Proteínas Argonautas/química , Proteínas Argonautas/classificação , Proteínas Argonautas/metabolismo , DNA/metabolismo , Ativação Enzimática , NAD/metabolismo , Células Procarióticas/metabolismo , RNA/metabolismoRESUMO
BACKGROUND: The acute changes in brain function in newborn infants undergoing ET remain unclear. This study aimed to determine whether fully automated simultaneous peripheral arteriovenous ET would influence the brain function. METHODS: A retrospective analysis was conducted on the clinical data of 39 neonates with hyperbilirubinemia who received ET. Seventeen patients were in the encephalopathy group, and the other 22 patients were in the non-encephalopathy group. Changes in amplitude-integrated electroencephalogram (aEEG) during ETs were analyzed, including background activities, sleep-wake cycling (SWC), and seizures. Before and after the ET, routine blood test parameters, electrolytes, blood glucose, and blood gas parameters were measured. RESULTS: After ETs, there were no significant changes in the levels of pH, PaO2, PaCO2, lactate, and red blood cells, while the levels of total bilirubin, indirect bilirubin, blood potassium, blood sodium, serum calcium, while blood cells, and platelets were significantly lower and the level of blood glucose was significantly higher compared to those before therapy. There was no significant difference in the changes of electroencephalographic activities during ETs, including background activities, SWC, and seizures. However, there were significant differences in suppressions on background activities, while there were no significant statistical differences in SWC or seizures between the 2 groups. CONCLUSION: Fully automated simultaneous peripheral arteriovenous ET is safe and efficient without significant influence on the disorder of the internal environment and electroencephalographic activities after ET in neonates. However, background activities are more significantly depressed in infants of bilirubin encephalopathy than infants of non-encephalopathy during ET.
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Hiperbilirrubinemia Neonatal , Encéfalo , Eletroencefalografia , Transfusão Total , Humanos , Hiperbilirrubinemia Neonatal/terapia , Recém-Nascido , Estudos RetrospectivosRESUMO
Purpose: To investigate the relationship between sleep duration and bedtime with myopia progression and axial elongation during a 4-year follow-up in primary school children. Methods: This study included 1887 children (aged 7.09 ± 0.41 years) who had cycloplegic refractions data at baseline and a fourth visit and 2209 children (aged 7.10 ± 0.41 years) for axial length. All children underwent comprehensive ophthalmologic examinations, including cycloplegic refraction and ocular biometry, and standardized questionnaires, including average night-time sleep duration (h/d) and bedtime (time to bed). Myopia was defined as spherical equivalent < -0.5 diopters. Results: At the last follow-up, the mean myopia progression and axial elongation for all children were -1.89 ± 1.28 diopters and 1.22 ± 0.57 mm. After stratifying the sleep duration into tertile groups, myopia progression and axial elongation were slower in children with highest sleep duration tertile (P = 0.04 and P =0.014) in girls but not in boys, compared with the middle sleep duration tertile. However, after adjusting for potential confounders, no significant association was found for sleep duration with myopia progression and axial elongation for the children (P = 0.255 and P = 0.068), and the association with axial elongation was only of borderline significance in girls (P = 0.045). The bedtime was not associated with myopia progression and axial elongation in the regression analyses (P = 0.538; P = 0.801). Conclusions: These results show that there was no significant association between sleep duration and bedtime with myopia progression and axial elongation among children. The findings in girls might be related to the earlier onset of puberty.
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Povo Asiático/etnologia , Miopia/diagnóstico , Sono/fisiologia , Comprimento Axial do Olho/patologia , Criança , Pré-Escolar , China/epidemiologia , Progressão da Doença , Feminino , Seguimentos , Humanos , Masculino , Miopia/etnologia , Miopia/fisiopatologia , Refração Ocular/fisiologia , Fatores de Risco , Inquéritos e QuestionáriosRESUMO
BACKGROUND: Herbochip® technology is a high throughput drug screening platform in a reverse screening manner, in which potential chemical leads in herbal extracts are immobilized and drug target proteins can be used as probes for screening process [BMC Complementary and Alternative Medicine (2015) 15:146]. While herbal medicines represent an ideal reservoir for drug screenings, here a molecular chaperone GRP78 is demonstrated to serve as a potential target for antiviral drug discovery. METHODS: We cloned and expressed a truncated but fully functional form of human GRP78 (hGRP781-508) and used it as a probe for anti-HBV drug screening on herbochips. In vitro cytotoxicity and in vitro anti-HBV activity of the herbal extracts were evaluated by MTT and ELISA assays, respectively. Finally, anti-HBV activity was confirmed by in vivo assay using DHBV DNA levels in DHBV-infected ducklings as a model. RESULTS: Primary screenings using GRP78 on 40 herbochips revealed 11 positives. Four of the positives, namely Dioscorea bulbifera, Lasiosphaera fenzlii, Paeonia suffruticosa and Polygonum cuspidatum were subjected to subsequent assays. None of the above extracts was cytotoxic to AML12 cells, but P. cuspidatum extract (PCE) was found to be cytotoxic to HepG2 2.2.15 cells. Both PCE and P. suffruticosa extract (PSE) suppressed secretion of HBsAg and HBeAg in HepG2 2.2.15 cells. The anti-HBV activity of PSE was further confirmed in vivo. CONCLUSION: We have demonstrated that GRP78 is a valid probe for anti-HBV drug screening on herbochips. We have also shown that PSE, while being non-cytotoxic, possesses in vitro and in vivo anti-HBV activities. Taken together, our data suggest that PSE may be a potential anti-HBV agent for therapeutic use.
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BACKGROUND/AIM: Estrogen is reported to promote the occurrence and development of several human cancers. Increasing evidence shows that most human lung tumors exert estrogen receptor expression. In the present study, we investigated the underlying mechanism of estrogen effect in lung cancer through estrogen receptor-epithelial-mesechymal-transition signaling pathways for the first time. MATERIALS AND METHODS: A total of 36 inbred C57BL/6 mice (18 male and 18 female) were injected subcutaneously with human lung adenocarcinoma cell line, Lewis. After the lung tumor model was established, mice with lung adenocarcinoma were randomly divided into three groups for each sex (n=6), such as vehicle group, estrogen group, and estrogen plus tamoxifen group. The six groups of mice were sacrificed after 21 days of drug treatment. Tumor tissue was stripped and weighed, and tumor inhibition rate was calculated based on average tumor weight. Protein and messenger RNA (mRNA) expressions of estrogen receptor α (ERα), estrogen receptor ß (ERß), phosphatidylinositol 3'-kinase (PI3K), AKT, E-cadherin, and vimentin were detected in both tumor tissue and lung tissue by using immunohistochemistry and real-time reverse transcription-polymerase chain reaction. RESULTS: 1) For male mice: in the estrogen group, estrogen treatment significantly increased ERα protein and mRNA expressions in tumor tissue and protein expression of PI3K, AKT, and vimentin in both tumor tissue and lung tissue compared with the vehicle-treated group. Besides, mRNA expression of E-cadherin was significantly reduced in estrogen-treated tumor tissues than that in vehicle-treated tissues. In the estrogen plus tamoxifen group, protein and mRNA expressions of ERα and AKT were dramatically reduced by tamoxifen treatment in tumor tissue compared with the estrogen group; mRNA expression of E-cadherin was increased in tumor tissue; protein expression of vimentin and PI3K were downregulated in tumor tissue; protein expression of E-cadherin increased in lung tissue; protein expression of ERα and PI3K were downregulated in lung tissue compared with the estrogen group. 2) For female mice: in the estrogen group, estrogen treatment significantly increased mRNA expression of ERß and PI3K, and protein expression of ERß, PI3K, AKT, and vimentin in both tumor tissue and lung tissue compared with the vehicle-treated group. mRNA expression of E-cadherin was downregulated in tumor tissue, and mRNA expression of AKT was increased in lung tissues compared with the vehicle-treated group. In the estrogen plus tamoxifen group, tamoxifen treatment dramatically reduced protein expression of ERα, ERß, AKT, and vimentin but significantly increased protein expression of E-cadherin in tumor tissues and lung tissue compared with the estrogen group. mRNA expression of ERß, PI3K, and AKT was dramatically reduced by tamoxifen treatment in lung tissues compared with the estrogen group. CONCLUSION: Estrogen promoted lung adenocarcinoma cell metastasis by inducing lung epithelial mesenchymal cells and reducing intercellular adhesion force through PI3K/AKT signaling pathway.
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The present study aimed to detect the role of 3, 4-dihydroxyl-phenyl lactic acid (DLA) during ischemia/reperfusion (I/R) induced myocardial injury with emphasis on the underlying mechanism of DLA antioxidant. Male Spragu-Dawley (SD) rats were subjected to left descending artery occlusion followed by reperfusion. Treatment with DLA ameliorated myocardial structure and function disorder, blunted the impairment of Complex I activity and mitochondrial function after I/R. The results of 2-D fluorescence difference gel electrophoresis revealed that DLA prevented the decrease in NDUFA10 expression, one of the subunits of Complex I. To find the target of DLA, the binding affinity of Sirtuin 1 (SIRT1) to DLA and DLA derivatives with replaced two phenolic hydroxyls was detected using surface plasmon resonance and bilayer interferometry. The results showed that DLA could activate SIRT1 after I/R probably by binding to this protein, depending on phenolic hydroxyl. Moreover, the importance of SIRT1 to DLA effectiveness was confirmed through siRNA transfection in vitro. These results demonstrated that DLA was able to prevent I/R induced decrease in NDUFA10 expression, improve Complex I activity and mitochondrial function, eventually attenuate cardiac structure and function injury after I/R, which was possibly related to its ability of binding to and activating SIRT1.
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Ácido Láctico/farmacologia , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/patologia , NADH Desidrogenase/metabolismo , Subunidades Proteicas/metabolismo , Animais , Apoptose/efeitos dos fármacos , Cardiotônicos/administração & dosagem , Cardiotônicos/farmacologia , Linhagem Celular , Modelos Animais de Doenças , Complexo I de Transporte de Elétrons/metabolismo , Expressão Gênica , Ácido Láctico/administração & dosagem , Ácido Láctico/análogos & derivados , Leucócitos/patologia , Masculino , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Traumatismo por Reperfusão Miocárdica/fisiopatologia , NADH Desidrogenase/genética , Ligação Proteica , Subunidades Proteicas/genética , Ratos , Espécies Reativas de Oxigênio/metabolismo , Sirtuína 1/metabolismo , Função Ventricular Esquerda/efeitos dos fármacosRESUMO
Lipopolysaccharide (LPS) causes microvascular barrier disruption, leading to albumin leakage from microvessels resulting in a range of disastrous sequels. Salvianolic acid B (SalB) is a major water-soluble component derived from Salvia miltiorrhiza. Previous studies showed its potential to attenuate microvascular barrier dysfunction, but the underlying mechanism is not fully understood. The present study was intended to investigate the impact of SalB on endothelial cell barrier in vivo in rat mesenteric venules as well as in vitro in human umbilical vein endothelial cells (HUVECs), aiming at disclosing the mechanism thereof, particularly the role of Src in its action. Male Wistar rats were challenged by infusion of LPS (2 mg/kg/h) through left femoral vein for 90 min. SalB (5 mg/kg/h) was administrated either simultaneously with LPS or 30 min after LPS infusion through the left jugular vein. Vesicles in venular walls were observed by electron microscopy. HUVECs were incubated with LPS with or without SalB. The expression of Zonula occluden-1 (ZO-1), VE-cadherin, caveolin-1 and Src in HUVECs was assessed by Western blot and confocal microscopy, binding of SalB to Src was measured using Surface Plasmon Resonance and BioLayer Interferometry. Treatment with SalB inhibited albumin leakage from rat mesenteric venules and inhibited the increase of vesicle number in venular endothelial cells induced by LPS. In addition, SalB inhibited the degradation of ZO-1, the phosphorylation and redistribution of VE-cadherin, the expression and phosphorylation of caveolin-1, and phosphoirylation of Src in HUVECs exposed to LPS. Furthermore, SalB was found able to bind to Src. This study demonstrates that protection of SalB against microvascular barrier disruption is a process involving both para- and trans-endothelial cell pathway, and highly suggests Src as the key enzyme for SalB to work.
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Albuminas/metabolismo , Benzofuranos/farmacologia , Lipopolissacarídeos/farmacologia , Veias Mesentéricas/metabolismo , Proteínas Proto-Oncogênicas pp60(c-src)/metabolismo , Animais , Células Endoteliais da Veia Umbilical Humana , Humanos , Masculino , Fosforilação , Ratos , Ratos Sprague-Dawley , Vênulas/metabolismoRESUMO
BACKGROUND: Geranium wilfordii is one of the major species used as Herba Geranii (lao-guan-cao) in China, it is commonly used solely or in polyherbal formulations for treatment of joint pain resulted from rheumatoid arthritis (RA) and gout. This herb is used to validate a target-based drug screening platform called Herbochip® and evaluate anti-inflammatory effects of Geranium wilfordii ethanolic extract (GWE) using tumor necrosis factor-alpha (TNF-α) as a drug target together with subsequent in vitro and in vivo assays. METHODS: A microarray-based drug screening platform was constructed by arraying HPLC fractions of herbal extracts onto a surface-activated polystyrene slide (Herbochip®). Using TNF-α as a molecular probe, fractions of 82 selected herbal extracts, including GWE, were then screened to identify plant extracts containing TNF-α-binding agents. Cytotoxicity of GWE and modulatory effects of GWE on TNF-α expression were evaluated by cell-based assays using TNF-α sensitive murine fibrosarcoma L929 cells as an in vitro model. RESULTS: The in vivo anti-inflammatory effects of GWE were further assessed by animal models including carrageenan-induced hind paw edema in rats and xylene-induced ear edema in mice, in comparison with aspirin. The hybridization data obtained by Herbochip® analysis showed unambiguous signals which confirmed TNF-α binding activity in 46 herbal extracts including GWE. In L929 cells GWE showed significant inhibitory effect on TNF-α expression with negligible cytotoxicity. GWE also significantly inhibited formation of carrageenan-induced hind paw edema and xylene-induced ear edema in animal models, indicating that it indeed possessed anti-inflammatory activity. CONCLUSION: We have thus validated effectiveness of the Herbochip® drug screening platform using TNF-α as a molecular target. Subsequent experiments on GWE lead us to conclude that the anti-RA activity of GWE can be attributed to inhibitory effect of GWE on the key inflammatory factor, TNF-α. Our results contribute towards validation of the traditional use of GWE in the treatment of RA and other inflammatory joint disorders.
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Anti-Inflamatórios/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Medicamentos de Ervas Chinesas/farmacologia , Geranium/química , Inflamação/tratamento farmacológico , Fitoterapia , Fator de Necrose Tumoral alfa/metabolismo , Animais , Anti-Inflamatórios/análise , Anti-Inflamatórios/farmacologia , Artrite Reumatoide/metabolismo , Carragenina/uso terapêutico , Linhagem Celular , China , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/uso terapêutico , Edema/tratamento farmacológico , Edema/metabolismo , Inflamação/induzido quimicamente , Inflamação/metabolismo , Masculino , Camundongos Endogâmicos ICR , Análise em Microsséries/métodos , Ratos Sprague-Dawley , XilenosRESUMO
PURPOSE: To describe distributions of ocular biometry and their associations with refraction in 7- and 14-year-old children in urban areas of Anyang, central China. METHODS: A total of 2271 grade 1 students aged 7.1 ± 0.4 years and 1786 grade 8 students aged 13.7 ± 0.5 years were measured with ocular biometry and cycloplegic refraction. A parental myopia questionnaire was administered to parents. RESULTS: Mean axial length, anterior chamber depth, lens thickness, central corneal thickness, corneal diameter, corneal radius of curvature, axial length/corneal radius of curvature ratio, and spherical equivalent refraction were 22.72 ± 0.76 mm, 2.89 ± 0.24 mm, 3.61 ± 0.19 mm, 540.5 ± 31 µm, 12.06 ± 0.44 mm, 7.80 ± 0.25 mm, 2.91 ± 0.08, and +0.95 ± 1.05 diopters (D), respectively, in 7-year-old children. They were 24.39 ± 1.13 mm, 3.42 ± 0.41 mm, 3.18 ± 0.24 mm, 548.9 ± 33 µm, 12.03 ± 0.43 mm, 7.80 ± 0.26 mm, 3.13 ± 0.14, and -2.06 ± 2.20 D, respectively, in 14-year-old children. Compared with 7-year-old children, the older group had significantly more myopia (-3.0 D), longer axial length (1.7 mm), deeper anterior chamber depth (0.3 mm), thinner lens thickness (-0.2 mm), thicker central corneal thickness (10 µm), and greater axial length/corneal radius of curvature ratio (0.22) (all p < 0.001), as well as smaller corneal diameter (-0.03 mm, p = 0.02) and similar corneal radius of curvature. Sex differences were similar in both age groups, with boys having longer axial length (0.5 mm), deeper anterior chamber depth (0.1 mm), shorter lens thickness (0.03 mm), greater central corneal thickness (5 µm), greater corneal diameter (0.15 mm), and greater corneal radius of curvature (0.14 mm) than girls (all p < 0.01). The most important variables related to spherical equivalent refraction were vitreous length, corneal radius of curvature, and lens thickness. CONCLUSIONS: The 14-year-old group had larger parameter dimensions than the 7-year-old group except for corneal radius of curvature (unchanged) and lens thickness and corneal diameter (both smaller). Boys had large parameter dimensions than girls except for lens thickness (smaller). Axial length, corneal radius of curvature, and lens thickness were the most important determinants of refraction.
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Povo Asiático/etnologia , Biometria/métodos , Hiperopia/etnologia , Miopia/etnologia , População Urbana/estatística & dados numéricos , Adolescente , Distribuição por Idade , Comprimento Axial do Olho/anatomia & histologia , Criança , China/epidemiologia , Feminino , Humanos , Masculino , Refração Ocular/fisiologia , Distribuição por Sexo , Inquéritos e QuestionáriosRESUMO
PURPOSE: To determine the distribution of peripheral refraction, including astigmatism, in 7- and 14-year-old Chinese children. METHODS: 2134 7-year-old and 1780 14-year-old children were measured with cycloplegic central and horizontal peripheral refraction (15° and 30° at temporal and nasal visual fields). RESULTS: 7- and 14-year-old children included 9 and 594, respectively, with moderate and high myopia (≤-3.0â D), 259 and 831 with low myopia (-2.99 to -0.5â D), 1207 and 305 with emmetropia (-0.49 to +1.0â D), and 659 and 50 with hyperopia (>1.0â D), respectively. Myopic children had relative peripheral hyperopia while hyperopic and emmetropic children had relative peripheral myopia, with greater changes in relative peripheral refraction occurring in the nasal than the temporal visual field. The older group had the greater relative peripheral hyperopia and higher peripheral J180. Both age groups showed positive slopes of J45 across the visual field, with greater slopes in the older group. CONCLUSIONS: Myopic children in mainland China have relative peripheral hyperopia while hyperopic and emmetropic children have relative peripheral myopia. Significant differences exist between 7- and 14-year-old children, with the latter showing more relative peripheral hyperopia, greater rate of change in J45 across the visual field, and higher peripheral J180.
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Hiperopia/epidemiologia , Miopia/epidemiologia , Refração Ocular/fisiologia , Adolescente , Astigmatismo/epidemiologia , Astigmatismo/fisiopatologia , Criança , China/epidemiologia , Feminino , Humanos , Hiperopia/fisiopatologia , Masculino , Miopia/fisiopatologia , Fatores de RiscoRESUMO
BACKGROUND/AIMS: Acute kidney injury (AKI) is a major complication of kidney transplantation, resulting in early graft dysfunction. Since diuretic acetazolamide (AZA) has been shown to improve contrast induced AKI, we hypothesized that AZA also protected against ischemia-reperfusion (I/R) caused AKI. METHODS: An in vivo mouse renal I/R injury model and an in vitro H2O2 stimulated HK-2 cell injury model were utilized to examine the renoprotective effect of AZA. Renal injury and blood flow were measured. Nitric oxide synthase (eNOS)/Nitric oxide (NO), cell apoptosis and hypoxia-inducible factor-1α (HIF-1α) changes were analyzed. RESULTS: AZA reduced kidney injury scores and improved renal function by decreasing serum creatinine and BUN levels after I/R. Impaired renal blood flow was restored by increasing eNOS activities and NO production, as indicated by Laser Doppler imaging. TUNEL staining presented that AZA reduced apoptotic cells due to attenuated caspase activation and increased Bcl-2/Bax ratio. Furthermore, HIF-1α induction by AZA was demonstrated. AZA also enhanced in vitro NO production, reduced cell apoptosis and increased HIF-1α expression. Knockdown of HIF-1α by RNAi confirmed that AZA exerted its protective role depending on HIF-1α. AZA's effects were significantly reduced by Akt inhibitor LY294002. CONCLUSIONS: The present study demonstrated that AZA exerted a renoprotective role against I/R induced AKI through activating HIF-1α and downstream pathways.
Assuntos
Acetazolamida/farmacologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Rim/irrigação sanguínea , Rim/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/prevenção & controle , Acetazolamida/farmacocinética , Animais , Apoptose/efeitos dos fármacos , Células Cultivadas , Técnicas de Silenciamento de Genes , Humanos , Peróxido de Hidrogênio/farmacologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Rim/metabolismo , Rim/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Óxido Nítrico , Óxido Nítrico Sintase Tipo III/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Circulação Renal/efeitos dos fármacosRESUMO
Cardiotonic pill (CP) is a compound Chinese medicine currently used in China for treatment of ischemic angina pectoris. Our previous results indicated that a single dosing of CP pretreatment at 0.8 g/kg attenuates ischemia/reperfusion- (I/R-) induced myocardial injury and cardiac microcirculatory disturbance. The present study aimed to investigate the effect of CP at low dosage in a multiple dosing manner and to uncover the mechanism of antioxidative activity of CP. Male Sprague-Dawley rats were subjected to left anterior descending artery occlusion for 30 min followed by 60 min reperfusion. CP was administrated daily by gavage for six days at 0.1, 0.4, and 0.8 g/kg/day before I/R. Results showed that multiple dosing of CP at three doses significantly reduced I/R-induced myocardial injury, microcirculatory disturbance, and oxidative stress. CP dramatically inhibited I/R-induced nicotinamide adenosine dinucleotide phosphate (NADPH) oxidase subunit gp91(phox) expression and p67(phox) and p47(phox) translocation from cytosol to cell membrane. Translocation of cytosolic subunits to membrane is required for the activation of NADPH oxidase. These data suggested that multiple dosing of CP at doses ranging from 0.1 to 0.8 g/kg/day reduced I/R-induced rat myocardial injury and microcirculatory disturbance, which was mediated by inhibition of NADPH oxidase activation.
RESUMO
QiShenYiQi Pills (QSYQ) is a compound Chinese medicine used for treatment of cardiovascular diseases. The present study investigated the effects of QSYQ on the Doxorubicin- (DOX-) induced disorders in rat cardiac structure and function and the possible mechanism underlying. A total of 24 male Sprague-Dawley rats were administrated by intraperitoneal injections with DOX at a dose of 2.5 mg/kg, once every day for a total of 6 times. After the 6th injection, the rats were evaluated by echocardiographic analysis, and the animals with injured heart (n = 14) were divided into 2 groups and further treated with (n = 7) or without (n = 7) QSYQ by gavage at a dose of 0.2 g/day, once a day, over the next 2 weeks. Two weeks after QSYQ treatment, the following variables were assessed: myocardial blood flow (MBF) by Laser-Doppler Perfusion Imager, the ratio of heart weight to body weight (HW/BW), myocardial histology, myocardial content of ATP, AMP, free fatty acids (FFAs) and AMP/ATP by ELISA, and expression of PPAR α , PGC-1 α , and ATP 5D by Western blot. Statistical analysis was performed using one-way ANOVA followed by Turkey test for multiple comparisons. DOX challenge significantly increased left ventricular internal diameter and HW/BW and decreased the thickness of the left ventricular posterior wall, the left ventricle ejection fraction, and the left ventricle fractional shortening. DOX also increased AMP, FFA, and AMP/ATP, decreased ATP, and downregulated the protein content of ATP 5D, PPAR α , and PGC-1 α . All these DOX-induced cardiac insults were attenuated significantly by QSYQ treatment. These results show the potential of QSYQ to ameliorate DOX-induced disorders in cardiac structure and function; this effect may be related to the increase in myocardial ATP content via the upregulation of ATP 5D, PPAR α , and PGC-1 α and the oxidation of FFA.
RESUMO
BACKGROUND: QiShenYiQi Pills® (QSYQ) is a compound Chinese medicine used in China for alleviating cardiac function. The present study was designed to explore the effect and mechanism of QSYQ on ischemia-reperfusion (I/R)-induced disorders in myocardial structure and function, with particularly focusing on the regulation of energy metabolism. METHODS: Sprague-Dawley rats, with or without QSYQ pretreatment, were subjected to 30 min occlusion of the left anterior descending coronary artery and followed by 90 min or 24h reperfusion. Myocardial blood flow (MBF) and cardiac function were evaluated at baseline, immediately after ischemia and 30, 60, 90 min, and 24h after reperfusion. Myocardial infarction, myocardial histology and ultrastructure were assessed. Double staining of alpha-cardiac actinin and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling was conducted to assess myocardial apoptosis. ATP, ADP and AMP content was determined by Enzyme-Linked Immunosorbent Assay, F-actin in myocardial cells determined by immunofluorescence microscopy and expression of ATP synthase α, ATP5D, and phosphorylated-Myosin Light Chain (P-MLC) determined by western blotting. RESULTS: Pre-treatment with QSYQ protected against I/R-induced MBF decrease, myocardial infarction and apoptosis at 90 min and 24h after reperfusion. Moreover, I/R 90 min caused an impairment on cardiac function, a decrease in the ratio of ADP/ATP and AMP/ATP, accompanying with reduction of ATP 5D expression and increase in the expression of P-MLC, meanwhile, myocardium to exhibit myocardial fiber rupture, interstitial edema, and mitochondria swelling, all of which were significantly ameliorated by pre-treatment with QSYQ. CONCLUSIONS: The results of the present study suggest an involvement of regulation of energy metabolism in the action of QSYQ to protect against myocardial I/R injury.