241 research outputs found
Fcγ receptors are required for NF-κB signaling, microglial activation and dopaminergic neurodegeneration in an AAV-synuclein mouse model of Parkinson's disease
Overexpression of alpha-synuclein (α-SYN), a protein which plays an important role in the pathogenesis of Parkinson's disease (PD), triggers microglial activation and adaptive immune responses, and leads to neurodegeneration of dopaminergic (DA) neurons. We hypothesized a link between the humoral adaptive immune response and microglial activation in α-SYN induced neurodegeneration. To test this hypothesis, we employed adeno-associated virus serotype 2 (AAV2) to selectively over-express human α-SYN in the substantia nigra (SN) of wild-type mice and FcγR-/- mice, which lack high-affinity receptors for IgG. We found that in wild-type mice, α-SYN induced the expression of NF-κB p65 and pro-inflammatory molecules. In FcγR-/- mice, NF-κB activation was blocked and pro-inflammatory signaling was reduced. Microglial activation was examined using immunohistochemistry for gp91PHOX. At four weeks, microglia were strongly activated in wild-type mice, while microglial activation was attenuated in FcγR-/- mice. Dopaminergic neurodegeneration was examined using immunohistochemistry for tyrosine hydroxylase (TH) and unbiased stereology. α-SYN overexpression led to the appearance of dysmorphic neurites, and a loss of DA neurons in the SN in wild-type animals, while FcγR-/- mice did not exhibit neuritic change and were protected from α-SYN-induced neurodegeneration 24 weeks after injection. Our results suggest that the humoral adaptive immune response triggered by excess α-SYN plays a causative role in microglial activation through IgG-FcγR interaction. This involves NF-κB signaling, and leads to DA neurodegeneration. Therefore, blocking either FcγR signaling or specific intracellular signal transduction events downstream of FcγR-IgG interaction, such as NF-κB activation, may be viable therapeutic strategies in PD
Artificial intelligence based approach to improve the frequency control in hybrid power system
Effects of advanced glycation end-products (AGEs) on skin keratinocytes by nuclear factor-kappa B (NF-κB) activation
Advance glycation end-products (AGEs) are produced in patients with long-term hyperglycemia metabolic disorder and responsible for multiple symptoms including impaired wound healing. This study was designed to reveal the roles and possible mechanism of AGE in diabetic wound healing. Sixteen Sprague-Dawley (SD) rats were divided into two groups randomly; the streptozotocin (STZ) induced diabetic group and the normal group. Eight weeks later, epidermal growth factor (EGF) and AGE levels, nuclear factor-kappa B (NF-κB) localization and cell viability were measured in vivo. Keratinocytes from normal skin were cultured in AGE-enriched conditional media, and the cell viability, apoptosis, adhesion and migration were detected in order to find the directed evidence between AGE and keratinocytes. AGE content was higher and NF-κB expression was more localized in the nuclear of keratinocytes in diabetic skins. AGE could inhibit normal cell growth by inducing apoptosis and arresting cell division cycle, inhibiting cell adhesion and promoting migration which might be mediated by NF-κB in vitro. Blocking NF-κB activity could reverse effects of AGE on cell proliferation and migration, but not adhesion. Therefore, AGE could damage the skin keratinocytes function in vivo and in vitro, and the activation of NF-κB is involved in this process.Key words: AGE, NF-kappaB, keratinocytes, diabetes, wound healing
Impact of road grid temporal and spatial changes on the ecosystem in the high-altitude plateau area : an empirical study
This empirical research utilized geographic information system (GIS) data and involved kernel density estimation (WKDE), ecological footprint modeling, landscape index analysis, and spatial analysis methods. A plateau landscape ecological risk model is constructed, and the temporal and spatial changes in the road network pattern and the landscape ecological risk in the region in 2012 and 2020 are investigated. The study results identify that the expansion of the road network led to a rapid increase in construction land area and a decrease in cultivated land area. However, there is little impact on other landscape types. The study reveals that road network expansion leads to landscape ecological risk changes, primarily in low-altitude urban centers. The risk levels decrease with increasing ecological risk levels, with the proportion of road level lengths increasing and decreasing. Landscape ecological risk and road level is correlated. This study will interest practitioners engaged in ecosystem management, infrastructure planning, and transportation systems development, as well as researchers in these and related areas.</p
Coal pillar burst mechanism and prevention based on local mine stiffness (LMS) criterion
The frequent occurrence of coal burst seriously threatens the safe and efficient recovery of coal resources. The research on the mechanism of coal burst is the basis of prediction and disaster prevention. Aiming at the coal burst event under the condition that the stress environment is stable and not affected by dynamic load, the concept of local mine stiffness (LMS) is introduced. Taking the mining area with complex mining layout of the mine as the engineering background, the mechanical response of coal pillar in the process of large-scale mining is analyzed by comprehensively using numerical analysis and field measurement, The evolution of LMS in this process is investigated. It is pointed out that the mining leads to the reduction of LMS, the rapid accumulation of energy in the coal seam and its roof and floor system, and the rapid release of energy when the coal pillar is unstable, resulting in impact damage. The engineering verification is carried out by comparing the evolution of LMS with the mining and the field measured ground sound and microseismic data. The research shows that:①the deformation, load and elastic energy accumulation of coal pillar increase with the overall mining operation, but the LMS decreases. The mining space size and the distance between the mining space and the research area are the main influencing factors. The response degree of the two to the mining of the working face is significantly greater than that of the roadway excavation. The significant influence range of the mining of the working face on the LMS reduction is 3.67 times that of the roadway excavation, and the LMS reduction under the unit advancing distance is 6.41 times that of the roadway excavation.②The good correspondence between the evolution of local mine stiffness with the advancement of the working face and the on-site ground sound and microseismic data indicates that the reduction of local mine stiffness caused by coal mining directly affects the failure mode of coal pillars. The energy in the coal seams and their roof and floor systems accumulates rapidly with the reduction of local mine stiffness and is released rapidly when the bearing capacity of coal pillars decreases, resulting in impact damage. ③After using large-diameter drilling to weaken the coal body, the microseismic energy and frequency are significantly reduced, indicating that large-diameter drilling destroys the coal body in this area, reduces its post peak stiffness, and effectively realizes the impact prevention effect
Optimization of Total Flavonoid Compound Extraction from Gynura medica Leaf Using Response Surface Methodology and Chemical Composition Analysis
Optimization of total flavonoid compound (TFC) extraction from Gynura medica leaf was investigated using response surface methodology (RSM) in this paper. The conditions investigated were 30–60% (v/v) ethanol concentration (X1), 85–95 °C extraction temperature (X2) and 30–50 (v/w) liquid-to-solid ratio (X3). Statistical analysis of the experiments indicated that temperature and liquid-to-solid ratio significantly affected TFC extraction (p < 0.01). The Box-Behnken experiment design showed that polynomial regression models were in good agreement with the experimental results, with the coefficients of determination of 0.9325 for TFC yield. The optimal conditions for maximum TFC yield were 55% ethanol, 92 °C and 50 (v/w) liquid-to-solid ratio with a 30 min extraction time. Extracts from these conditions showed a moderate antioxidant value of 54.78 μmol quercetin/g dry material (DM), 137.3 μmol trolox/g DM for 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 108.21 μmol quercetin/g DM, 242.31 μmol trolox/g DM for 2,2-azino-bis-(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS+), respectively. HPLC-DAD-MS analysis showed that kaempferol-3-O-glucoside was the principal flavonoid compound in Gynura medica leaf
Efficacy and safety of Lianhua Qingwen granule in the treatment of non-influenza viral pneumonia: a randomized, double-blind, placebo-controlled, multicenter clinical study
ObjectiveTo observe the effectiveness and safety of Lianhua Qingwen granule in the treatment of non-influenza viral pneumonia.MethodsThis study was a multicenter, randomized, double-blind, placebo-controlled trial. Subjects who met the inclusion and exclusion criteria and were clinically diagnosed with viral pneumonia (negative for influenza virus) were randomly divided into the Lianhua Qingwen granule trial group and placebo control group. Patients in the trial group was given Lianhua Qingwen granule, 2 bags at a time, 3 times a day, and the controls were given placebo, with a treatment course of 7 days. Patients’ clinical symptoms and signs, and treatment-associated adverse events were observed. Subjects should be included in the full analysis set (FAS) as long as they were all given the medication and had an effectiveness test performed after randomization. Subjects should be included in the Per Protocol Set (PPS),a subset of the total analysis set, which should contain those with strong compliance, no protocol violations, and complete baseline values for the primary indicators.ResultsA total of 169 subjects were enrolled in 12 subcenters, including 151 (76 in the trial group and 75 in the control group) in the FAS and 140 (68 in the trial group and 72 in the control group) in the PPS. After 7 days of treatment, the clinical symptom relief rates were 82.98% (FAS) and 87.12% (PPS) in the trial group, and 75.11% (FAS) and 76.02% (PPS) in the control group, respectively. The clinical symptom relief rates in the trial group were significantly higher than those in the control group (p < 0.001). Significant improvements in single symptoms of cough and expectoration in the trial group were observed compared with the control group (p < 0.05). There were no statistical differences in fever, sputum color change, chest pain, muscle pain, dyspnea, chills, and thirst between the two groups (p > 0.05).SafetyThere were no significant differences in body weight, vital signs, blood routine, urine routine, stool routine, and blood biochemical indicators (CK, AST, ALT, Cr, and Bun) between the two groups before and after treatment (p > 0.05). During treatment, there were no significant differences in the incidence of adverse events and serious adverse events between the two groups (p > 0.05).ConclusionLianhua Qingwen granules improved the clinical symptoms of patients with non-influenza virus pneumonia, especially ameliorating cough and expectoration. Lianhua Qingwen granules were associated with good safety
Prognostic significance of proline, glutamic acid, leucine rich protein 1 (PELP1) in triple-negative breast cancer: a retrospective study on 129 cases
BACKGROUND: Triple-negative breast cancer (TNBC) is associated with an aggressive clinical course due to the lack of therapeutic targets. Therefore, identifying reliable prognostic biomarkers and novel therapeutic targets for patients with TNBC is required. Proline, glutamic acid, leucine rich protein 1 (PELP1) is a novel steroidal receptor co-regulator, functioning as an oncogene and its expression is maintained in estrogen receptor (ER) negative breast cancers. PELP1 has been proposed as a prognostic biomarker in hormone-related cancers, including luminal-type breast cancers, but its significance in TNBC has not been studied. METHODS: PELP1 immunoreactivity was evaluated using immunohistochemistry in 129 patients with TNBC. Results were correlated with clinicopathological variables including patient’s age, tumor size, lymph node stage, tumor grade, clinical stage, histological type, Ki-67 LI, as well as clinical outcome of the patients, including disease-free survival (DFS) and overall survival (OS). RESULTS: PELP1 was localized predominantly in the nuclei of carcinoma cells in TNBC. With the exception of a positive correlation between PELP1 protein expression and lymph node stage (p = 0.027), no significant associations between PELP1 protein expression and other clinicopathological variables, including DFS and OS, were found. However, when PELP1 and Ki-67 LI were grouped together, we found that patients in the PELP1/Ki-67 double high group (n = 48) demonstrated significantly reduced DFS (p = 0.005, log rank test) and OS (p = 0.002, log rank test) than others (n = 81). Multivariable analysis supported PELP1/Ki-67 double high expression as an independent prognostic factor in patients with TNBC, with an adjusted hazard ratio of 2.020 for recurrence (95 % CL, 1.022–3.990; p = 0.043) and of 2.380 for death (95 % CL, 1.138–4.978; p = 0.021). CONCLUSIONS: We found that evaluating both PELP1 and Ki-67 expression in TNBC could enhance the prognostic sensitivity of the two biomarkers. Therefore, we propose that PELP1/Ki-67 double high expression in tumors is an independent prognostic factor for predicting a poor outcome for patients with TNBC
Cytokine Signaling in a Mouse Model of Parkinson\u27s Disease
The protein alpha-synuclein (α-SYN), which is found in the Lewy bodies of dopaminergic (DA) neurons in the substantia nigra (SN), has an important role in the pathogenesis of Parkinson\u27s disease (PD). Fcγ receptors (FcγR) are proteins present on the surface of microglia, which bind immunoglobulin G (IgG) and other ligands. Our studies in an AAV-synuclein mouse model of PD showed that over-abundance of α-SYN triggered the expression of NF-κB p65, and led to microglial activation and DA neurodegeneration; however, in mice deficient of gamma chain subunit of the Fc receptors (FcγR-/- mice), α-SYN-induced NF-κB signaling was blocked, while microglial activation and DA neurodegeneration were attenuated. In order to study whether α-SYN interacts directly with microglia, we treated the primary microglia of wild-type (WT) and FcγR-/- mice with aggregated human α-SYN in vitro. We found that α-SYN was taken up by both WT and FcγR-/- microglia though with different internalization patterns. α-SYN-induced nuclear accumulation of NF-κB p65 and downstream chemokine expression in WT microglia were blocked in FcγR-/- ones. Moreover, we hypothesize that excess α-SYN causes further microgliosis through major histocompatibility complex-II (MHC-II) antigen presentation to T-lymphocytes, and this process is FcγR-dependent. To test this hypothesis, in vivo we selectively over-expressed human α-SYN in the SN of WT and FcγR-/- mice, and in vitro, we performed T-cell co-culture with WT and FcγR-/- microglia. Over-abundance of α-SYN in mouse SN triggered IgG deposition and vigorous MHC-II expression in the brain, and these immune responses were markedly attenuated in FcγR-/- mice. α-SYN-treated microglia-T cell co-culture produced increased pro-inflammatory molecules and this elevated cytokine expression was blocked with FcγR-/- microglia. Our results suggest that the humoral adaptive immune response triggered by excess α-SYN plays a causative role in microglial activation through IgG-FcγR interaction. This involves NF-κB signaling, and leads to DA neurodegeneration. To further activate microglia, α-SYN-induced microglial MHC-II antigen presentation to CD4+ T-lymphocytes is a crucial step, and FcγRs are indispensable in this process. Therefore, blocking either FcγR signaling or specific intracellular events downstream of FcγR-IgG interaction, such as NF-κB activation or MHC-II antigen presentation may be viable therapeutic strategies in PD
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