215 research outputs found

    Roles and regulation of Aquaporin-3 in maintaining the gut health: an updated review

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    Aquaporin-3 (AQP3) is a predominant water channel protein expressed in the intestine, and plays important roles in the gut physiology and pathophysiology due to its permeability to water, glycerol and hydrogen peroxide. In this review, we systematically summarized the current understanding of the expression of AQP3 in the intestine of different species, and focused on the potential roles of AQP3 in water transport, different types of diarrhea and constipation, intestinal inflammation, intestinal barrier function, oxidative stress, and autophagy. These updated findings have supported that AQP3 may function as an important target in maintaining gut health of human and animals

    Composite Hydrogels with the Simultaneous Release of VEGF and MCP-1 for Enhancing Angiogenesis for Bone Tissue Engineering Applications

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    Rapid new microvascular network induction was critical for bone regeneration, which required the spatiotemporal delivery of growth factors and transplantation of endothelial cells. In this study, the linear poly(d,l-lactic-co-glycolic acid)-b-methoxy poly(ethylene glycol) (PLGA-mPEG) block copolymer microspheres were prepared for simultaneously delivering vascular endothelial growth factor (VEGF) and monocyte chemotactic protein-1 (MCP-1). Then, vascular endothelial cells (VECs) with growth factor loaded microspheres were composited into a star-shaped PLGA-mPEG block copolymer solution. After this, composite hydrogel (microspheres ratio: 5 wt%) was formed by increasing the temperature to 37 °C. The release profiles of VEGF and MCP-1 from composite hydrogels in 30 days were investigated to confirm the different simultaneous delivery systems. The VECs exhibited a good proliferation in the composite hydrogels, which proved that the composite hydrogels had a good cytocompatibility. Furthermore, in vivo animal experiments showed that the vessel density and the mean vessel diameters increased over weeks after the composite hydrogels were implanted into the necrosis site of the rabbit femoral head. The above results suggested that the VECs-laden hydrogel composited with the dual-growth factor simultaneous release system has the potential to enhance angiogenesis in bone tissue engineering

    Effects of High-Stakes Accountability Testing on Teacher Motivation

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    There is always a driving force behind our actions in any given situation. In 2000, NCLB instituted accountability testing with strict requirements for all schools in the U.S., hoping to motivate teachers to reach higher levels of instruction by using sanctions or rewards against teachers when standards were not met. However, Deci and Ryan¿s (2000) SDT explains that fostering intrinsic motivation and providing autonomy support for an individual results in more effective outcomes and increased satisfaction. Private and public school teachers in PA were surveyed using the Work Climate Questionnaire and the Work Task Motivation Scale for Teachers to examine differences in self-reported motivation and perceived autonomy support in order to investigate if the use of high-stakes accountability testing (HST) is related to decreased teacher motivation. The results from ANOVAs and correlations indicate differences in self-reported motivation levels of teachers in public and private schools, as well as aid ratio, grade taught, number of years in teaching, and the time the participant responded (before or after the PSSA), as well as perceived autonomy support, suggesting that the presence of HST may influence motivation in teachers

    Absence of Appl2 sensitizes endotoxin shock through activation of PI3K/Akt pathway

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    BACKGROUND: The adapter proteins Appl1 (adaptor protein containing pleckstrin homology domain, phosphotyrosine domain, and leucine zipper motif 1) and Appl2 are highly homologous and involved in several signaling pathways. While previous studies have shown that Appl1 plays a pivotal role in adiponectin signaling and insulin secretion, the physiological functions of Appl2 are largely unknown. RESULTS: In the present study, the role of Appl2 in sepsis shock was investigated by using Appl2 knockout (KO) mice. When challenged with lipopolysaccharides (LPS), Appl2 KO mice exhibited more severe symptoms of endotoxin shock, accompanied by increased production of proinflammatory cytokines. In comparison with the wild-type control, deletion of Appl2 led to higher levels of TNF-α and IL-1β in primary macrophages. In addition, phosphorylation of Akt and its downstream effector NF-κB was significantly enhanced. By co-immunoprecipitation, we found that Appl2 and Appl1 interacted with each other and formed a complex with PI3K regulatory subunit p85α, which is an upstream regulator of Akt. Consistent with these results, deletion of Appl1 in macrophages exhibited characteristics of reduced Akt activation and decreased the production of TNFα and IL-1β when challenged by LPS. CONCLUSIONS: Results of the present study demonstrated that Appl2 is a critical negative regulator of innate immune response via inhibition of PI3K/Akt/NF-κB signaling pathway by forming a complex with Appl1 and PI3K.published_or_final_versio

    CACNA2D3 Enhances the Chemosensitivity of Esophageal Squamous Cell Carcinoma to Cisplatin via Inducing Ca2+-Mediated Apoptosis and Suppressing PI3K/Akt Pathways

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    Resistance to platinum-based combination chemotherapy is the main cause of poor prognosis in patients with advanced esophageal squamous cell carcinoma (ESCC). Previously, we showed that CACNA2D3 (voltage-dependent subunit alpha 2 delta 3 of a calcium channel complex) was significantly downregulated and functioned as a tumor suppressor in ESCC, but its role in the chemosensitivity of ESCC to cisplatin remained unknown. Here, we found that the expression of CACNA2D3 was significantly associated with poor platinum response in ESCC patients from the Gene Expression Omnibus database. Overexpression of CACNA2D3 increased sensitivity to cisplatin in ESCC in vitro, whereas knockdown of CACNA2D3 increased cisplatin resistance. CACNA2D3 promoted cisplatin-induced apoptosis by modulating intracellular Ca2+ stores. In vivo experiments further showed that overexpression of CACNA2D3 enhanced cisplatin anti-tumor effects in a xenograft mouse model. CACNA2D3 overexpression also resulted in the attenuation of PI3K and Akt phosphorylation. Treatment with the PI3K/Akt inhibitor LY294002 restored the chemosensitivity of CACAN2D3-knockdown cells to cisplatin. In conclusion, the results of the current study indicate that CACAN2D3 enhances the chemosensitivity of ESCC to cisplatin via inducing Ca2+-mediated apoptosis and suppressing PI3K/Akt pathways. Therefore, regulating the expression of CACNA2D3 is a potential new strategy to increase the efficacy of cisplatin in ESCC patients

    Bacteroides vulgatus alleviates dextran sodium sulfate-induced colitis and depression-like behaviour by facilitating gut-brain axis balance

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    BackgroundPatients with inflammatory bowel disease (IBD) have a higher prevalence of depression. Gut microbiota dysbiosis plays an important role in IBD and depression. However, few studies have explored the characteristic microbiota of patients with IBD and depression (IBDD), or their role in IBDD.MethodsWe performed deep metagenomic sequencing and 16S rDNA quantitative PCR to characterise the gut microbial communities of patients with IBDD and patients with IBD without depression (IBDND). We then assessed the effect of the microbiota on colitis and depression in mouse models of dextran sulfate sodium salt (DSS)-induced colitis and lipopolysaccharide (LPS)-induced depression. Furthermore, liquid chromatography–tandem mass spectrometry was used to analyse the microbiota-derived metabolites involved in gut–brain communication. Evans Blue tracer dye was used to assess blood–brain barrier (BBB) permeability.ResultsOur results showed that the faecal abundance of Bacteroides vulgatus (B. vulgatus) was lower in patients with IBDD than in those with IBDND. In the DSS-induced colitis mouse model, the B. vulgatus group showed a significantly lower disease activity index score, lesser weight loss, and longer colon length than the DSS group. Moreover, B. vulgatus relieved depression-like behaviour in the DSS-induced colitis mouse model and in the LPS-induced depression mouse model. Furthermore, the key metabolite of B. vulgatus was p-hydroxyphenylacetic acid (4-HPAA), which was found to relieve intestinal inflammation and alleviate depression-like behaviours in mouse models. By increasing the expression of the tight junction protein claudin-5 in the vascular endothelium of the BBB, B. vulgatus and 4-HPAA play critical roles in gut–brain communication.ConclusionB. vulgatus and B. vulgatus-derived 4-HPAA ameliorated intestinal inflammation and relieved depressive symptoms through the gut–brain axis. Thus, administration of B. vulgatus or 4-HPAA supplementation is a promising therapeutic strategy for treating IBD, particularly IBDD
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