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Background and objective: Hemorrhagic stroke, characterized by acute bleeding due to cerebrovascular lesions, is associated with plasma lipids and endothelial damage. The causal relationship between genetic plasma lipid levels and hemorrhagic stroke remains unclear. This study employs a two-sample Mendelian randomization (MR) analysis to explore the causal relationship between plasma lipid profiles with different fatty acid chains and the risk of intracerebral and subarachnoid hemorrhage, the two main subtypes of hemorrhagic stroke. Methods: The datasets for exposure and outcome summary statistics were obtained from publicly available sources such as the GWAS Catalog, IEU OpenGWAS project, and FinnGen. The two-sample MR analysis was employed to initially assess the causal relationship between 179 plasma lipid species and the risk of intracerebral and subarachnoid hemorrhage in the Finnish population, leading to the identification of candidate lipids. The same methods were applied to reanalyze data from European populations and conduct a meta-analysis of the candidate lipids. The Inverse Variance Weighting (IVW) method served as the primary analysis for causal inference, with additional methods used for complementary analyses. Sensitivity analysis was conducted to clarify causal relationships and reduce biases. Results: Two analyses using Mendelian randomization were performed, followed by meta-analyses of the results. A causal relationship was established between 11 specific lipid species and the occurrence of intracerebral hemorrhage within the European population. Additionally, 5 distinct lipid species were associated with subarachnoid hemorrhage. Predominantly, lipids with linoleic acid and arachidonic acid side chains were identified. Notably, lipids containing arachidonic acid chains (C20:4) such as PC 18:1;0_20:4;0 consistently showed a decreased risk of both intracerebral hemorrhage [p < 0.001; OR(95% CI) = 0.892(0.835-0.954)] and subarachnoid hemorrhage [p = 0.002; OR(95% CI) = 0.794(0.689-0.916)]. Conversely, lipids with linoleic acid chains (C18:2) were associated with an increased risk of intracerebral hemorrhage. Conclusion: This study identifies a potential causal relationship between lipids with different fatty acid side chains and the risk of intracerebral and subarachnoid hemorrhagic stroke, improving the understanding of the mechanisms behind the onset and progression of hemorrhagic stroke.
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OBJECTIVE: To investigate the potential diagnostic and prognostic implications of inflammatory cytokine levels in the cerebrospinal fluid (CSF) of patients with spontaneous intracerebral hemorrhage (SICH) upon their initial hospital admission. METHODS: Our cohort included 100 patients diagnosed with acute SICH, presenting to the Department of Neurosurgery. Additionally, we recruited 50 individuals without central nervous system (CNS) pathology, treated concurrently at our facility, as controls. CSF samples, collected upon hospital entry, were quantitatively assessed for 10 inflammatory cytokines using the Mesoscale Discovery Platform (MSD, Rockville, MD, USA) electrochemiluminescence technology, followed by validation through enzyme-linked immunosorbent assay (ELISA). RESULTS: We observed a marked elevation of IL-6, IL-8, IL-10, and TNF-α in the CSF of the SICH subgroup compared to controls. Higher Glasgow Coma Scale (GCS) scores in SICH patients corresponded with lower CSF concentrations of IL-6, IL-8, IL-10, and TNF-α, indicating an inverse relationship. Notably, CSF inflammatory cytokine levels were consistently higher in SICH patients with hydrocephalus than in those without. Increases in IL-6, IL-8, IL-10, and TNF-α in the CSF were notably more pronounced in the poor prognosis group (Glasgow Outcome Scale, GOS 1-3) compared to those with a favorable prognosis (GOS 4-5). The AUC values for these cytokines in predicting SICH prognosis were 0.750, 0.728, 0.717, and 0.743, respectively. CONCLUSIONS: Initial CSF levels of IL-6, IL-8, IL-10, and TNF-α upon admission provide significant insights into the severity of neural damage and are robust indicators for prognosis in SICH patients.
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Citocinas , Interleucina-10 , Humanos , Fator de Necrose Tumoral alfa , Interleucina-6 , Interleucina-8/líquido cefalorraquidiano , Hemorragia Cerebral/diagnóstico , PrognósticoRESUMO
AIM: Intracerebral hemorrhage (ICH) is a serious complication of neurosurgery associated with high mortality and disability. Long non-coding RNA (lncRNA) maternally expressed gene 3 (MEG3) is an endogenous RNA that competes with miR-181b in the regulation of central nervous system (CNS) biological activity. Ubiquitin C-terminal hydrolase L1 (UCH-L1), a downstream target of miR-181b, is a prominent biomarker for ICH. MATERIAL AND METHODS: In this study, we studied the lncRNA MEG3 and miR-181b expression in 30 patients with ICH who were admitted to the General Hospital of Xinjiang Military Command from January 2021 to May 2021 by quantitative polymerase chain reaction. Serum levels of UCH-L1 were detected by enzyme-linked immune sorbent assay, and disease severity was evaluated using the Glasgow Coma Scale. We also recorded ICH-related deaths in hospital. RESULTS: In this study, we studied the lncRNA MEG3 and miR-181b expression in 30 patients with ICH who were admitted to the General Hospital of Xinjiang Military Command from January 2021 to May 2021 by quantitative polymerase chain reaction. Serum levels of UCH-L1 were detected by enzyme-linked immune sorbent assay, and disease severity was evaluated using the Glasgow Coma Scale. We also recorded ICH-related deaths in hospital. CONCLUSION: Our data indicated that lnc-MEG3, miR-181b, and UCH-L1 are likely involved in the pathophysiology of ICH, and could form the basis of future studies on potential targets for the treatment of traumatic CNS injuries. UCH-L1 could also find application in ICH management. Further studies on the plasma lncRNA-MEG3, miR-181b, and UCH-L1 levels in patients with ICH could yield novel biological targets for the prediction and treatment of ICH.
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Ginkgolide B (GB), a terpene lactone and active ingredient of Ginkgo biloba, shows protective effects in neuronal cells subjected to hypoxia. We investigated whether GB might protect neurons from hypoxic injury through regulation of neuronal Ca2+ homeostasis. Primary hippocampal neurons subjected to chemical hypoxia (0.7 mM CoCl2) in vitro exhibited an increase in cytoplasmic Ca2+ (measured from the fluorescence of fluo-4), but this effect was significantly diminished by pre-treatment with 0.4 mM GB. Electrophysiological recordings from the brain slices of rats exposed to hypoxia in vivo revealed increases in spontaneous discharge frequency, action potential frequency and calcium current magnitude, and all these effects of hypoxia were suppressed by pre-treatment with 12 mg/kg GB. Western blot analysis demonstrated that hypoxia was associated with enhanced mRNA and protein expressions of Cav1.2 (a voltage-gated Ca2+ channel), STIM1 (a regulator of store-operated Ca2+ entry) and RyR2 (isoforms of Ryanodine Receptor which mediates sarcoplasmic reticulum Ca2+ release), and these actions of hypoxia were suppressed by GB. Taken together, our in vitro and in vivo data suggest that GB might protect neurons from hypoxia, in part, by regulating Ca2+ influx and intracellular Ca2+ release to maintain Ca2+ homeostasis.
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Nitric oxide (NO) is involved in neuronal modifications, and overproduction of NO contributes to memory deficits after acute hypobaric hypoxia-reoxygenation. This study investigated the ability of the iNOS inhibitor 1400W to counteract spatial memory deficits following acute hypobaric hypoxia-reoxygenation, and to affect expression of NOS, NO, 3-NT and MDA production, and apoptosis in rat cerebral cortex. We also used primary rat microglia to investigate the effect of 1400W on expression of NOS, NO, 3-NT and MDA production, and apoptosis. Acute hypobaric hypoxia-reoxygenation impaired spatial memory, and was accompanied by activated microglia, increased iNOS expression, NO, 3-NT and MDA production, and neuronal cell apoptosis in rat cerebral cortex one day post-reoxygenation. 1400W treatment inhibited iNOS expression without affecting nNOS or eNOS. 1400W also reduced NO, 3-NT and MDA production, and prevented neuronal cell apoptosis in cerebral cortex, in addition to reversing spatial memory impairment after acute hypobaric hypoxia-reoxygenation. Hypoxia-reoxygenation activated primary microglia, and increased iNOS and nNOS expression, NO, 3-NT, and MDA production, and apoptosis. Treatment with 1400W inhibited iNOS expression without affecting nNOS, reduced NO, 3-NT and MDA production, and prevented apoptosis in primary microglia. Based on the above findings, we concluded that the highly selective iNOS inhibitor 1400W inhibited iNOS induction in microglial cells, and reduced generation of NO, thereby mitigating oxidative stress and neuronal cell apoptosis in the rat cerebral cortex, and improving the spatial memory dysfunction caused by acute hypobaric hypoxia-reoxygenation.
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Transtornos Cognitivos , Regulação da Expressão Gênica/efeitos dos fármacos , Iminas/farmacologia , Iminas/uso terapêutico , Microglia/enzimologia , Óxido Nítrico Sintase Tipo II/metabolismo , Animais , Anexina A5/metabolismo , Apoptose/efeitos dos fármacos , Células Cultivadas , Transtornos Cognitivos/tratamento farmacológico , Transtornos Cognitivos/etiologia , Transtornos Cognitivos/patologia , Modelos Animais de Doenças , Regulação da Expressão Gênica/fisiologia , Hipóxia/complicações , Peroxidação de Lipídeos/efeitos dos fármacos , Malondialdeído/metabolismo , Aprendizagem em Labirinto/efeitos dos fármacos , Proteínas do Tecido Nervoso/metabolismo , Óxido Nítrico/metabolismo , Oxigênio/farmacologia , Ratos , Ratos Sprague-Dawley , Tirosina/análogos & derivados , Tirosina/metabolismoRESUMO
The physiological level of nitric oxide (NO) released by brain microvascular endothelial cells (BMECs) at normoxia can block the degradation of hypoxia-inducible factor-1α (HIF-1α) in astrocytes and initiate the compensatory response to hypoxia. However, it is unclear whether this occurs at mild hypoxia. This study was to investigate the expression of HIF-1α, VEGF and LDHA and the lactic acid production in astrocytes with or without co-culture with BMECs after mild hypoxia exposure. During mild hypoxia (5% O2), exogenous NO blocked the degradation of HIF-1α in astrocytes but up-regulated the transcription of VEGF and LDHA, accompanied by elevated expression of VEGF protein and increased production of lactic acid. This was further confirmed by silencing of HIF-1α expression in astrocytes. In astrocytes co-cultured with primary rat BMEC under mild hypoxia, NO was released by the BMECs and prevented the degradation of HIF-1α in astrocytes, leading to the up-regulated mRNA expression of VEGF and LDHA, elevated VEGF protein expression and increased production of lactic acid. In BMECs, NO was derived from intracellular eNOS. Based on these findings, we hypothesize that, under mild hypoxia, even though astrocytes do not respond to hypoxia, NO produced by BMECs may transmit a hypoxia signal to astrocytes, triggering their adaptive response via HIF-1α.
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The p38 mitogen-activated protein kinase (MAPK) plays a key role in lipopolysaccharide (LPS)-induced signal transduction pathways that lead to inflammatory cytokine synthesis in macrophages; however, whether the inhibition of p38 MAPK regulates LPS-induced inflammatory cytokine expression in different types of macrophages remains the subject of debate. Herein, we assessed whether the inhibition of p38 MAPK by SB203580 regulates LPS-induced expression of the inflammatory cytokines tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) in RAW264.7 and resident peritoneal macrophages. Lipopolysaccharide stimulation of RAW264.7 macrophages or mouse resident peritoneal macrophages significantly increased TNF-α and IL-6 production. The addition of SB203580 to cultures dramatically blocked LPS-induced TNF-α production in RAW264.7 and mouse resident peritoneal macrophages, and dramatically blocked LPS-induced IL-6 production in RAW264.7 macrophages, but not in mouse resident peritoneal macrophages. Additionally, high concentrations of SB203580 resulted in increased IL-6 production. However, LPS-stimulation significantly up-regulated the mRNA transcript levels of TNF-α and IL-6 in RAW264.7 and mouse resident peritoneal macrophages, whereas pretreatment with SB203580 dramatically down-regulated LPS-induced mRNA transcript levels of TNF-α and IL-6 in these cells. Our data show that SB203580 differentially modulates LPS-induced production of the inflammatory cytokine IL-6 in two different sources of macrophages, and that this course of regulation occurs at the IL-6 mRNA post-transcriptional stage.
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Inflammatory responses are important to host immune reactions, but uncontrolled inflammatory mediators may aid in the pathogenesis of other inflammatory diseases. Geniposide, an iridoid glycoside found in the herb gardenia, is believed to have broad-spectrum anti-inflammatory effects in murine models but its mechanism of action is unclear. We investigated the action of this compound in murine macrophages stimulated by lipopolysaccharide (LPS), as the stimulation of macrophages by LPS is known to induce inflammatory reactions. We determined the effect of geniposide on LPS-induced production of the inflammatory mediators, nitric oxide (NO) and prostaglandin E2 (PGE2), the mRNA and protein expression of the NO and PGE2 synthases, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), respectively, and the mRNA and protein expression of the inflammatory cytokine, tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). Furthermore, nuclear factor (NF)-κB, mitogen-activated protein kinase (MAPK) and activator protein (AP)-1 activity were assayed. To understand the action of geniposide on the NF-κB and MAPK pathways, we studied the effect of NF-κB and MAPK inhibitors on the LPS-induced production of NO, PGE2 and TNF-α. Our findings clearly showed that geniposide mainly exerts its anti-inflammatory effects by inhibiting the LPS-induced NF-κB, MAPK and AP-1 signaling pathways in macrophages, which subsequently reduces overexpression of the inducible enzymes iNOS and COX-2 and suppresses the expression and release of the inflammatory factors, TNF-α, IL-6, NO and PGE2. Thus, geniposide shows promise as a therapeutic agent in inflammatory diseases.
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Anti-Inflamatórios/farmacologia , Gardenia , Iridoides/farmacologia , Macrófagos Peritoneais/efeitos dos fármacos , Animais , Butadienos/farmacologia , Linhagem Celular , Ciclo-Oxigenase 2/genética , Ciclo-Oxigenase 2/metabolismo , Dinoprostona/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , Imidazóis/farmacologia , Mediadores da Inflamação/metabolismo , Interleucina-6/genética , Interleucina-6/metabolismo , Lipopolissacarídeos/imunologia , Macrófagos Peritoneais/imunologia , Masculino , Camundongos , Camundongos Endogâmicos , NF-kappa B/antagonistas & inibidores , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Nitrilas/farmacologia , Piridinas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Sulfonas/farmacologia , Fator de Transcrição AP-1/metabolismo , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Acute exposure to high altitudes can cause neurological dysfunction due to decreased oxygen availability to the brain. In this study, the protective effects of Huperzine A on cognitive deficits along with oxidative and apoptotic damage, due to acute hypobaric hypoxia, were investigated in male Sprague-Dawley rats. Rats were exposed to simulated hypobaric hypoxia at 6,000 m in a specially fabricated animal decompression chamber while receiving daily Huperzine A orally at the dose of 0.05 or 0.1 mg/kg body weight. After exposure to hypobaric hypoxia for 5 days, rats were trained in a Morris Water Maze for 5 consecutive days. Subsequent trials revealed Huperzine A supplementation at a dose of 0.1 mg/kg body weight restored spatial memory significantly, as evident from decreased escape latency and path length to reach the hidden platform, and the increase in number of times of crossing the former platform location and time spent in the former platform quadrant. In addition, after exposure to hypobaric hypoxia, animals were sacrificed and biomarkers of oxidative damage, such as reactive oxygen species, lipid peroxidation, lactate dehydrogenase activity, reduced glutathione, oxidized glutathione and superoxide dismutase were studied in the hippocampus. Expression levels of pro-apoptotic proteins (Bax, caspase-3) and anti-apoptotic protein (Bcl-2) of hippocampal tissues were evaluated by Western blotting. There was a significant increase in oxidative stress along with increased expression of apoptotic proteins in hypoxia exposed rats, which was significantly improved by oral Huperzine A at 0.1 mg/kg body weight. These results suggest that supplementation with Huperzine A improves cognitive deficits, reduces oxidative stress and inhibits the apoptotic cascade induced by acute hypobaric hypoxia.
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Alcaloides/uso terapêutico , Transtornos Cognitivos/tratamento farmacológico , Transtornos Cognitivos/psicologia , Hipocampo/efeitos dos fármacos , Hipóxia Encefálica/tratamento farmacológico , Hipóxia Encefálica/psicologia , Fármacos Neuroprotetores/uso terapêutico , Estresse Oxidativo/efeitos dos fármacos , Sesquiterpenos/uso terapêutico , Pressão do Ar , Animais , Comportamento Animal/efeitos dos fármacos , Biomarcadores , Western Blotting , Doença da Descompressão/psicologia , Glutationa/metabolismo , Hipocampo/metabolismo , Hipóxia Encefálica/metabolismo , L-Lactato Desidrogenase/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Memória/efeitos dos fármacos , Desempenho Psicomotor/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismoRESUMO
A Yersinia pestis-human protein interaction network is reported here to improve our understanding of its pathogenesis. Up to 204 interactions between 66 Y. pestis bait proteins and 109 human proteins were identified by yeast two-hybrid assay and then combined with 23 previously published interactions to construct a protein-protein interaction network. Topological analysis of the interaction network revealed that human proteins targeted by Y. pestis were significantly enriched in the proteins that are central in the human protein-protein interaction network. Analysis of this network showed that signaling pathways important for host immune responses were preferentially targeted by Y. pestis, including the pathways involved in focal adhesion, regulation of cytoskeleton, leukocyte transendoepithelial migration, and Toll-like receptor (TLR) and mitogen-activated protein kinase (MAPK) signaling. Cellular pathways targeted by Y. pestis are highly relevant to its pathogenesis. Interactions with host proteins involved in focal adhesion and cytoskeketon regulation pathways could account for resistance of Y. pestis to phagocytosis. Interference with TLR and MAPK signaling pathways by Y. pestis reflects common characteristics of pathogen-host interaction that bacterial pathogens have evolved to evade host innate immune response by interacting with proteins in those signaling pathways. Interestingly, a large portion of human proteins interacting with Y. pestis (16/109) also interacted with viral proteins (Epstein-Barr virus [EBV] and hepatitis C virus [HCV]), suggesting that viral and bacterial pathogens attack common cellular functions to facilitate infections. In addition, we identified vasodilator-stimulated phosphoprotein (VASP) as a novel interaction partner of YpkA and showed that YpkA could inhibit in vitro actin assembly mediated by VASP.
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Proteínas de Bactérias/metabolismo , Peste/imunologia , Peste/microbiologia , Yersinia pestis/patogenicidade , Biologia Computacional , Regulação da Expressão Gênica/imunologia , Células HEK293 , Interações Hospedeiro-Patógeno/imunologia , Humanos , Ligação Proteica , Virulência , Yersinia pestis/imunologiaRESUMO
BACKGROUND: In the enteropathogenic Yersinia species, RovA regulates the expression of invasin, which is important for enteropathogenic pathogenesis but is inactivated in Yersinia pestis. Investigation of the RovA regulon in Y. pestis at 26 °C has revealed that RovA is a global regulator that contributes to virulence in part by the direct regulation of psaEFABC. However, the regulatory roles of RovA in Y. pestis at 37 °C, which allows most virulence factors in mammalian hosts to be expressed, are still poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: The transcriptional profile of an in-frame rovA mutant of Y. pestis biovar Microtus strain 201 was analyzed under type III secretion system (T3SS) induction conditions using microarray techniques, and it was revealed that many cell-envelope and transport/binding proteins were differentially expressed in the ΔrovA mutant. Most noticeably, many of the T3SS genes, including operons encoding the translocon, needle and Yop (Yersinia outer protein) effectors, were significantly up-regulated. Analysis of Yop proteins confirmed that YopE and YopJ were also expressed in greater amounts in the mutant. However, electrophoresis mobility shift assay results demonstrated that the His-RovA protein could not bind to the promoter sequences of the T3SS genes, suggesting that an indirect regulatory mechanism is involved. Transmission electron microscopy analysis indicated that there are small loose electron dense particle-like structures that surround the outer membrane of the mutant cells. The bacterial membrane permeability to CFSE (carboxyfluorescein diacetate succinimidyl ester) was significantly decreased in the ΔrovA mutant compared to the wild-type strain. Taken together, these results revealed the improper construction and dysfunction of the membrane in the ΔrovA mutant. CONCLUSIONS/SIGNIFICANCE: We demonstrated that the RovA regulator plays critical roles in the construction and functioning of the bacterial membrane, which sheds considerable light on the regulatory functions of RovA in antibiotic resistance and environmental adaptation. The expression of T3SS was upregulated in the ΔrovA mutant through an indirect regulatory mechanism, which is possibly related to the altered membrane construction in the mutant.
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Proteínas de Bactérias/metabolismo , Membrana Celular/metabolismo , Regulação Bacteriana da Expressão Gênica , Genes Reguladores , Fatores de Transcrição/metabolismo , Yersinia pestis/metabolismo , Animais , Proteínas de Bactérias/genética , Membrana Celular/genética , Humanos , Camundongos , Peste/microbiologia , Fatores de Transcrição/genética , Yersinia pestis/genéticaRESUMO
BACKGROUND: Although assays for detecting Yersinia pestis using TaqMan probe-based real-time PCR have been developed for years, little is reported on room-temperature-stable PCR reagents, which will be invaluable for field epidemic surveillance, immediate response to public health emergencies, counter-bioterrorism investigation, etc. In this work, a set of real-time PCR reagents for rapid detection of Y. pestis was developed with extraordinary stability at 37 degrees C. METHODS/PRINCIPAL FINDINGS: TaqMan-based real-time PCR assays were developed using the primers and probes targeting the 3a sequence in the chromosome and the F1 antigen gene caf1 in the plasmid pMT1of Y. pestis, respectively. Then, carbohydrate mixtures were added to the PCR reagents, which were later vacuum-dried for stability evaluation. The vacuum-dried reagents were stable at 37 degrees C for at least 49 days for a lower concentration of template DNA (10 copies/microl), and up to 79 days for higher concentrations (> or =10(2) copies/microl). The reagents were used subsequently to detect soil samples spiked with Y. pestis vaccine strain EV76, and 5x10(4) CFU per gram of soil could be detected by both 3a- and caf1-based PCR reagents. In addition, a simple and efficient method for soil sample processing is presented here. CONCLUSIONS/SIGNIFICANCE: The vacuum-dried reagents for real-time PCR maintain accuracy and reproducibility for at least 49 days at 37 degrees C, indicating that they can be easily transported at room temperature for field application if the machine for performing real-time PCR is available. This dry reagent is of great significance for routine plague surveillance.