36 research outputs found

    Pathogenesis mechanism of Pestalotiopsis funerea toxin (Pf-toxin) on the plasmalemma of needle cells of different pine species

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    The Pf-toxin (C5H11O5N) has been genetically associated with the pathogenesis mechanism in plasmalemma cells of pine needles in previous reports. In this study, a toxin was obtained from Pestalotiopsis funerea (called Pf- toxin) by concentrating and column chromatography. Responses of the needles of eight pine species against the toxin were investigated. The O2- production rate, malondialdehyde (MDA) content, fatty acid composition, relative conductivity, and lesion length of the needles were determined. The severest damage and lipid peroxidation were exhibited by the needle plasmalemma of Pinus massoniana, Pinus yunnanensis, and Pinus tabuliformis. Pinus elliottii and Pinus taeda followed. Pinus armandi, Pinus radiata and Pinus thunbergii came last. The resistance capability of resistant species against the Pf-toxin precedes that of susceptible species. Keywords: Pestalotiopsis funerea, Pestalotia needle blight, Pinus, resistance. African Journal of Biotechnology Vol. 11(29), pp. 7397-7407, 10 April, 201

    Inhibition of neutrophil extracellular trap formation attenuates NLRP1-dependent neuronal pyroptosis via STING/IRE1α pathway after traumatic brain injury in mice

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    IntroductionIncreased neutrophil extracellular trap (NET) formation has been reported to be associated with cerebrovascular dysfunction and neurological deficits in traumatic brain injury (TBI). However, the biological function and underlying mechanisms of NETs in TBI-induced neuronal cell death are not yet fully understood.MethodsFirst, brain tissue and peripheral blood samples of TBI patients were collected, and NETs infiltration in TBI patients was detected by immunofluorescence staining and Western blot. Then, a controlled cortical impact device was used to model brain trauma in mice, and Anti-Ly6G, DNase, and CL-amidine were given to reduce the formation of neutrophilic or NETs in TBI mice to evaluate neuronal death and neurological function. Finally, the pathway changes of neuronal pyroptosis induced by NETs after TBI were investigated by administration of peptidylarginine deiminase 4 (a key enzyme of NET formation) adenovirus and inositol-requiring enzyme-1 alpha (IRE1α) inhibitors in TBI mice.ResultsWe detected that both peripheral circulating biomarkers of NETs and local NETs infiltration in the brain tissue were significantly increased and had positive correlations with worse intracranial pressure (ICP) and neurological dysfunction in TBI patients. Furthermore, the depletion of neutrophils effectively reduced the formation of NET in mice subjected to TBI. we found that degradation of NETs or inhibition of NET formation significantly inhibited nucleotide-binding oligomerization domain (NOD)-like receptor pyrin domain containing 1 (NLRP1) inflammasome-mediated neuronal pyroptosis after TBI, whereas these inhibitory effects were abolished by cyclic GMP-AMP (cGAMP), an activator of stimulating Interferon genes (STING). Moreover, overexpression of PAD4 in the cortex by adenoviruses could aggravate NLRP1-mediated neuronal pyroptosis and neurological deficits after TBI, whereas these pro-pyroptotic effects were rescued in mice also receiving STING antagonists. Finally, IRE1α activation was significantly upregulated after TBI, and NET formation or STING activation was found to promote this process. Notably, IRE1α inhibitor administration significantly abrogated NETs-induced NLRP1 inflammasome-mediated neuronal pyroptosis in TBI mice.DiscussionOur findings indicated that NETs could contribute to TBI-induced neurological deficits and neuronal death by promoting NLRP1-mediated neuronal pyroptosis. Suppression of the STING/ IRE1α signaling pathway can ameliorate NETs-induced neuronal pyroptotic death after TBI

    MiR-124-3p attenuates brain microvascular endothelial cell injury in vitro by promoting autophagy

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    . Traumatic brain injury (TBI) can cause the pathological disruption of the blood-brain barrier (BBB) and associated neurological injury. Reducing the severity of such barrier disruption following TBI can decrease the degree of brain edema, suppress intracranial inflammation, and thereby protect against neurological damage. The BBB is made up of brain microvascular endothelial cells (BMVECs), neurons, pericytes, astrocytes, and extracellular matrix components. In prior analyses, we have demonstrated that miR-124-3p expression is enhanced in microglia-derived exosomes following TBI, with this miRNA being capable of promoting neural repair after such injury. Based upon these results, the present study was formulated to examine the impact of miR-124-3p on BMVEC function and to evaluatethe mechanistic basis for its activity by overexpressing miR-124-3p in these endothelial cells. We utilized a bEnd.3 cell scratch wound in vitro model to simulate TBI-associated brain microvascular endothelial cell injury. Lipofectamine3000 was used to transfect endothelial cells such that they overexpressed miR-124-3p. Fluorescence microscopy was used to observe the effects of miR-124-3p expression on these endothelial cells. TUNEL+CD31 immunofluorescence stainingwas employed to observe endothelial cell apoptosis. Tight junctions were observed via ionconductivity microscopy. Western blotting was used to detect the expression of tight junction proteins (occludin, ZO-1), autophagy-associated proteins (Beclin1, p62, LC3-II/LC3-I), and mTOR-associated proteins (p-mTOR, PDE4B). Chloroquine was used to treat these injured endothelial cells overexpressing miR-124-3p, and endothelial cell apoptosis was assessed via TUNEL+CD31 immunofluorescence staining. We found that the upregulation of miR-124-3p was sufficient to suppress bEnd.3 cell apoptotic death following in vitro scratch injury while promoting the upregulation of the tight junction proteins ZO-1 and occludin in these cells, thereby reducing the degree of leakage across the cerebral microvascular endothelial barrier. These protective effects may be related to the ability of miR124-3p to suppress mTOR signaling and to induce autophagic activity within BMVECs. These data support a model wherein miR-124-3p can inhibit mTOR signaling and promote autophagic induction in BMVECs, thereby protecting these cells against TBIinduced damage

    Abrocitinib Attenuates Microglia-Mediated Neuroinflammation after Traumatic Brain Injury via Inhibiting the JAK1/STAT1/NF-κB Pathway

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    Background and Purpose: Neuroinflammation has been shown to play a critical role in secondary craniocerebral injury, leading to poor outcomes for TBI patients. Abrocitinib, a Janus kinase1 (JAK1) selective inhibitor approved to treat atopic dermatitis (AD) by the Food and Drug Administration (FDA), possesses a novel anti-inflammatory effect. In this study, we investigated whether abrocitinib could ameliorate neuroinflammation and exert a neuroprotective effect in traumatic brain injury (TBI) models. Methods: First, next-generation sequencing (NGS) was used to select genes closely related to neuroinflammation after TBI. Then, magnetic resonance imaging (MRI) was used to dynamically observe the changes in traumatic focus on the 1st, 3rd, and 7th days after the induction of fluid percussion injury (FPI). Moreover, abrocitinib’s effects on neurobehaviors were evaluated. A routine peripheral blood test was carried out and Evans blue dye extravasation, cerebral cortical blood flow, the levels of inflammatory cytokines, and changes in the numbers of inflammatory cells were evaluated to investigate the function of abrocitinib on the 1st day post-injury. Furthermore, the JAK1/signal transducer and activator of transcription1 (STAT1)/nuclear factor kappa (NF-κB) pathway was assessed. Results: In vivo, abrocitinib treatment was found to shrink the trauma lesions. Compared to the TBI group, the abrocitinib treatment group showed better neurological function, less blood-brain barrier (BBB) leakage, improved intracranial blood flow, relieved inflammatory cell infiltration, and reduced levels of inflammatory cytokines. In vitro, abrocitinib treatment was shown to reduce the pro-inflammatory M1 microglia phenotype and shift microglial polarization toward the anti-inflammatory M2 phenotype. The WB and IHC results showed that abrocitinib played a neuroprotective role by restraining JAK1/STAT1/NF-κB levels after TBI. Conclusions: Collectively, abrocitinib treatment after TBI is accompanied by improvements in neurological function consistent with radiological, histopathological, and biochemical changes. Therefore, abrocitinib can indeed reduce excessive neuroinflammation by restraining the JAK1/STAT1/NF-κB pathway

    Interpenetrated nano- and submicro-fibrous biomimetic scaffolds towards enhanced mechanical and biological performances

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    Supplementary data to this article can be found online at https:// doi.org/10.1016/j.msec.2019.110416.Developing fibrous scaffolds with hierarchical structures that closely mimic natural extracellular matrix (ECM) is highly desirable. However, fabricating scaffolds with true nanofibers (90%. Additionally, the combination of CA submicrofibers with BC nanofibers leads to significantly improved mechanical properties over nanofibrous BC and submicrofibrous CA scaffolds and enlarged pores over nanofibrous BC scaffold. In addition, the biological behaviors of prepared BC/CA on MC3T3-E1 cells were investigated. Results suggested that BC/CA scaffold is beneficial for cell migration and proliferation. Moreover, the BC/CA scaffold shows higher alkaline phosphatase (ALP) activity, and calcium depositions. In addition, the hierarchical structures can effectively improve the expression of osteogenic gene (ALP mRNA and Runx2 mRNA) and protein (ALP). We believe that the methodology might provide biomimetic morphological microenvironments for enhanced tissue regeneration.This work is supported by the National Natural Science Foundation of China (Grant nos. 51973058, 31870963, 51572187, and 51563008), the Excellent Young Scientists Fund by National Natural Science Foundation of China (No. 31722022), the Youth Science Foundation of Jiangxi Province (No. 20171ACB21036 and 20181BAB216010).info:eu-repo/semantics/publishedVersio

    Prenatal whole-exome sequencing for fetal structural anomalies: a retrospective analysis of 145 Chinese cases

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    Abstract Background Whole-exome sequencing (WES) significantly improves the diagnosis of the etiology of fetal structural anomalies. This study aims to evaluate the diagnostic value of prenatal WES and to investigate the pathogenic variants in structurally abnormal fetuses. Methods We recruited 144 fetuses with structural anomalies between 14 and 2020 and 15 December 2021 in the study. Genetic screening was performed by WES combined with karyotyping and chromosomal microarray analysis. The molecular diagnostic yield of prenatal WES for each type of fetal structural anomaly and the identified pathogenic genes and mutations were reported. Results In this study, we retrospectively analyzed the clinical and genetic data of 145 structurally anomalous fetuses. These cases were classified into 9 phenotypic classes based on antenatal ultrasound findings. Thirty-eight pathogenic variants in 24 genes were identified in 35 of the 145 cases, including 14 novel variants in 13 genes (EP300, MYH3, TSC2, MMP9, CPLANE1, INVS, COL1A1, EYA1, TTC21B, MKS1, COL11A2, PDHA1 and L1CAM). Five additional pathogenic variants were classified as incidental findings. Our study showed that the overall diagnosis rate of WES was 28.1% (27/96) in the parent-fetus trio cases and 16.3% (8/49) in the proband-only cases. Fetuses with musculoskeletal anomalies had the highest diagnostic yield (51.4%, 19/37). In addition, FGFR3 and COL1A1 were the most common pathogenic genes. Conclusions Our work expands the mutation spectrum of the genes associated with fetal structural anomalies and provides valuable information for future parental genetic counselling and pregnancy management of the structurally anomalous fetuses

    Multiple Steady-States Analysis and Unstable Operating Point Stabilization in Homogeneous Azeotropic Distillation with Intermediate Entrainer

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    The steady-state multiplicity in azeotropic distillation processes has been theoretically predicted and verified experimentally for decades. However, it is a tough task to detect all the steady-state solutions. The purpose of this article is 2-fold: first, it provides a systematical study on the multiplicity in homogeneous azeotropic distillation with intermediate entrainer and a novel strategy is proposed to find all the steady-state solutions using “Design Specs/Vary” in Aspen Plus. Operating on the unstable steady-state branch benefits both energy saving and reducing capital investment with the product quality specified. Because of the great benefits that operating on the unstable steady-state branch offers, the second purpose is to present suitable control schemes to stabilize the operating point on the unstable steady-state branch to achieve robust control

    Intranasal Delivery of Gene-Edited Microglial Exosomes Improves Neurological Outcomes after Intracerebral Hemorrhage by Regulating Neuroinflammation

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    Neural inflammatory response is a crucial pathological change in intracerebral hemorrhage (ICH) which accelerates the formation of perihematomal edema and aggravates neural cell death. Although surgical and drug treatments for ICH have advanced rapidly in recent years, therapeutic strategies that target and control neuroinflammation are still limited. Exosomes are important carriers for information transfer among cells. They have also been regarded as a promising therapeutic tool in translational medicine, with low immunogenicity, high penetration through the blood-brain barrier, and ease of modification. In our previous research, we have found that exogenous administration of miRNA-124-overexpressed microglial exosomes (Exo-124) are effective in improving post-injury cognitive impairment. From this, we evaluated the potential therapeutic effects of miRNA-124-enriched microglial exosomes on the ICH mice in the present study. We found that the gene-edited exosomes could attenuate neuro-deficits and brain edema, improve blood–brain barrier integrity, and reduce neural cell death. Moreover, the protective effect of Exo-124 was abolished in mice depleted of Gr-1+ myeloid cells. It suggested that the exosomes exerted their functions by limiting the infiltration of leukocyte into the brain, thus controlling neuroinflammation following the onset of ICH. In conclusion, our findings provided a promising therapeutic strategy for improving neuroinflammation in ICH. It also opens a new avenue for intranasal delivery of exosome therapy using miRNA-edited microglial exosomes
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