321 research outputs found

    AMatFormer: Efficient Feature Matching via Anchor Matching Transformer

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    Learning based feature matching methods have been commonly studied in recent years. The core issue for learning feature matching is to how to learn (1) discriminative representations for feature points (or regions) within each intra-image and (2) consensus representations for feature points across inter-images. Recently, self- and cross-attention models have been exploited to address this issue. However, in many scenes, features are coming with large-scale, redundant and outliers contaminated. Previous self-/cross-attention models generally conduct message passing on all primal features which thus lead to redundant learning and high computational cost. To mitigate limitations, inspired by recent seed matching methods, in this paper, we propose a novel efficient Anchor Matching Transformer (AMatFormer) for the feature matching problem. AMatFormer has two main aspects: First, it mainly conducts self-/cross-attention on some anchor features and leverages these anchor features as message bottleneck to learn the representations for all primal features. Thus, it can be implemented efficiently and compactly. Second, AMatFormer adopts a shared FFN module to further embed the features of two images into the common domain and thus learn the consensus feature representations for the matching problem. Experiments on several benchmarks demonstrate the effectiveness and efficiency of the proposed AMatFormer matching approach.Comment: Accepted by IEEE Transactions on Multimedia (TMM) 202

    HSP27 Alleviates Cardiac Aging in Mice via a Mechanism Involving Antioxidation and Mitophagy Activation

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    Aging-induced cardiac dysfunction is a prominent feature of cardiac aging. Heat shock protein 27 (HSP27) protects cardiac function against ischemia or chemical challenge. We hypothesized that HSP27 attenuates cardiac aging. Transgenic (Tg) mice with cardiac-specific expression of the HSP27 gene and wild-type (WT) littermates were employed in the experiments. Echocardiography revealed a significant decline in the cardiac function of old WT mice compared with young WT mice. In striking contrast, the aging-induced impairment of cardiac function was attenuated in old Tg mice compared with old WT mice. Levels of cardiac aging markers were lower in old Tg mouse hearts than in old WT mouse hearts. Less interstitial fibrosis and lower contents of reactive oxygen species and ubiquitin-conjugated proteins were detected in old Tg hearts than in old WT hearts. Furthermore, old Tg hearts demonstrated lower accumulation of LC3-II and p62 than old WT hearts. Levels of Atg13, Vps34, and Rab7 were also higher in old Tg hearts than in old WT hearts. Additionally, old Tg hearts had higher levels of PINK1 and Parkin than old WT hearts, suggesting that mitophagy was activated in old Tg hearts. Taken together, HSP27 alleviated cardiac aging and this action involved antioxidation and mitophagy activation

    Phosphoinositide-3-kinase/akt - Dependent Signaling is Required for Maintenance of [Ca\u3csup\u3e2+\u3c/sup\u3e]\u3csub\u3eI,\u3c/sub\u3eI\u3csub\u3eCa\u3c/sub\u3e, and Ca\u3csup\u3e2+\u3c/sup\u3e Transients in HL-1 Cardiomyocytes

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    The phosphoinositide 3-kinases (PI3K/Akt) dependent signaling pathway plays an important role in cardiac function, specifically cardiac contractility. We have reported that sepsis decreases myocardial Akt activation, which correlates with cardiac dysfunction in sepsis. We also reported that preventing sepsis induced changes in myocardial Akt activation ameliorates cardiovascular dysfunction. In this study we investigated the role of PI3K/Akt on cardiomyocyte function by examining the role of PI3K/Akt-dependent signaling on [Ca 2+]i, Ca2+ transients and membrane Ca2+ current, ICa, in cultured murine HL-1 cardiomyocytes. LY294002 (120 μM), a specific PI3K inhibitor, dramatically decreased HL-1 [Ca 2+]i, Ca2+ transients and ICa. We also examined the effect of PI3K isoform specific inhibitors, i.e. α (PI3-kinase α inhibitor 2; 28 nM); ? (TGX-221; 100 nM) and γ (AS-252424; 100 nM), to determine the contribution of specific isoforms to HL-1 [Ca 2+]i regulation. Pharmacologic inhibition of each of the individual PI3K isoforms significantly decreased [Ca2+]i, and inhibited Ca 2+ transients. Triciribine (120 μM), which inhibits AKT downstream of the PI3K pathway, also inhibited [Ca2+]i, and Ca 2+ transients and ICa. We conclude that the PI3K/Akt pathway is required for normal maintenance of [Ca2+]i in HL-1 cardiomyocytes. Thus, myocardial PI3K/Akt-PKB signaling sustains [Ca 2+]i required for excitation-contraction coupling in cardiomyoctyes

    TLR3 Mediates Repair and Regeneration of Damaged Neonatal Heart through Glycolysis Dependent YAP1 Regulated miR-152 Expression

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    The present study investigated whether TLR3 is required for neonatal heart repair and regeneration following myocardial infarction (MI). TLR3 deficient neonatal mice exhibited impaired cardiac functional recovery and a larger infarct size, while wild type neonatal mice showed cardiac functional recovery and small infarct size after MI. The data suggest that TLR3 is essential for the regeneration and repair of damaged neonatal myocardium. In vitro treatment of neonatal cardiomyocytes with a TLR3 ligand, Poly (I:C), significantly enhances glycolytic metabolism, YAP1 activation and proliferation of cardiomyocytes which were prevented by a glycolysis inhibitor, 2-deoxyglucose (2-DG). Administration of 2-DG to neonatal mice abolished cardiac functional recovery and YAP activation after MI, suggesting that TLR3-mediated regeneration and repair of the damaged neonatal myocardium is through glycolytic-dependent YAP1 activation. Inhibition of YAP1 activation abolished Poly (I:C) induced proliferation of neonatal cardiomyocytes. Interestingly, activation of YAP1 increases the expression of miR-152 which represses the expression of cell cycle inhibitory proteins, P27kip1 and DNMT1, leading to cardiomyocyte proliferation. We conclude that TLR3 is required for neonatal heart regeneration and repair after MI. The mechanisms involve glycolytic-dependent YAP1 activation, resulting in miR-152 expression which targets DNMT1/p27kip1

    HSPA12B Attenuated Acute Myocardial Ischemia/reperfusion Injury via Maintaining Endothelial Integrity in a PI3K/Akt/mTOR-dependent Mechanism

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    Endothelial damage is a critical mediator of myocardial ischemia/reperfusion (I/R) injury. HSPA12B is an endothelial-cell-specifically expressed heat shock protein. However, the roles of HSPA12B in acute myocardial I/R injury is unknown. Here we reported that myocardial I/R upregulated HSPA12B expression in ventricular tissues, and endothelial overexpression of HSPA12B in transgenic mice (Tg) limited infarct size, attenuated cardiac dysfunction and improved cardiomyocyte survival compared with their wild type littermates. These improvements were accompanied with the diminished myocardial no-reflow phenomenon, decreased microvascular leakage, and better maintained endothelial tight junctions. The I/R-evoked neutrophil infiltration was also suppressed in Tg hearts compared with its wild type (WT) littermates. Moreover, Tg hearts exhibited the enhanced activation of PI3K/Akt//mTOR signaling following I/R challenge. However, pharmacological inhibition of PI3K abolished the HSPA12B-induced cardioprotection against myocardial I/R injury. The data demonstrate for the first time that the endothelial HSPA12B protected hearts against myocardial I/R injury. This cardioprotective action of HSPA12B was mediated, at least in part, by improving endothelial integrity in a PI3K/Akt/mTOR-dependent mechanism. Our study suggests that targeting endothelial HSPA12B could be an alternative approach for the management of patients with myocardial I/R injury

    HSPA12B: A Novel Facilitator of Lung Tumor Growth

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    Lung tumor progression is regulated by proangiogenic factors. Heat shock protein A12B (HSPA12B) is a recently identified regulator of expression of proangiogenic factors. However, whether HSPA12B plays a role in lung tumor growth is unknown. To address this question, transgenic mice overexpressing HSPA12B (Tg) and wildtype littermates (WT) were implanted with Lewis lung cancer cells to induce lung tumorigenesis. Tg mice showed significantly higher number and bigger size of tumors than WT mice. Tg tumors exhibited increased angiogenesis and proliferation while reduced apoptosis compared with WT tumors. Interestingly, a significantly enhanced upregulation of Cox-2 was detected in Tg tumors than in WT tumors. Also, Tg tumors demonstrated upregulation of VEGF and angiopoietin-1, downregulation of AKAP12, and increased eNOS phosphorylation compared with WT tumors. Celecoxib, a selective Cox-2 inhibitor, suppressed the HSPA12B-induced increase in lung tumor burden. Moreover, celecoxib decreased angiogenesis and proliferation whereas increased apoptosis in Tg tumors. Additionally, celecoxib reduced angiopoietin-1 expression and eNOS phosphorylation but increased AKAP12 levels in Tg tumors. Our results indicate that HSPA12B stimulates lung tumor growth via a Cox-2-dependent mechanism. The present study identified HSPA12B as a novel facilitator of lung tumor growth and a potential therapeutic target for the treatment of lung cancer

    Baicalein inhibits IL-1β- and TNF-α-induced inflammatory cytokine production from human mast cells via regulation of the NF-κB pathway

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    <p>Abstract</p> <p>Background</p> <p>Human mast cells are multifunctional cells capable of a wide variety of inflammatory responses. Baicalein (BAI), isolated from the traditional Chinese herbal medicine Huangqin (<it>Scutellaria baicalensis Georgi</it>), has been shown to have anti-inflammatory effects. We examined its effects and mechanisms on the expression of inflammatory cytokines in an IL-1β- and TNF-α-activated human mast cell line, HMC-1.</p> <p>Methods</p> <p>HMC-1 cells were stimulated either with IL-1β (10 ng/ml) or TNF-α (100 U/ml) in the presence or absence of BAI. We assessed the expression of IL-6, IL-8, and MCP-1 by ELISA and RT-PCR, NF-κB activation by electrophoretic mobility shift assay (EMSA), and IκBα activation by Western blot.</p> <p>Results</p> <p>BAI (1.8 to 30 μM) significantly inhibited production of IL-6, IL-8, and MCP-1 in a dose-dependent manner in IL-1β-activated HMC-1. BAI (30 μM) also significantly inhibited production of IL-6, IL-8, and MCP-1 in TNF-α-activated HMC-1. Inhibitory effects appear to involve the NF-κB pathway. BAI inhibited NF-κB activation in IL-1β- and TNF-α-activated HMC-1. Furthermore, BAI increased cytoplasmic IκBα proteins in IL-1β- and TNF-α-activated HMC-1.</p> <p>Conclusion</p> <p>Our results showed that BAI inhibited the production of inflammatory cytokines through inhibition of NF-κB activation and IκBα phosphorylation and degradation in human mast cells. This inhibitory effect of BAI on the expression of inflammatory cytokines suggests its usefulness in the development of novel anti-inflammatory therapies.</p

    HSPA12A Is Required for Adipocyte Differentiation and Diet-Induced Obesity Through a Positive Feedback Regulation With PPARγ

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    Obesity is one of the most serious public health problems. Peroxisome proliferator-activated receptor γ (PPARγ) plays the master role in adipocyte differentiation for obesity development. However, optimum anti-obesity drug has yet been developed, mandating more investigation to identify novel regulator in obesity pathogenesis. Heat shock protein 12A (HSPA12A) encodes a novel member of the HSP70 family. Here, we report that obese patients showed increased adipose HSPA12A expression, which was positively correlated with increase of body mass index. Intriguingly, knockout of HSPA12A (Hspa12a−/−) in mice attenuated high-fat diet (HFD)-induced weight gain, adiposity, hyperlipidemia, and hyperglycemia compared to their wild type (WT) littermates. Increased insulin sensitivity was observed in Hspa12a−/− mice compared to WT mice. The HFD-induced upregulation of PPARγ and its target adipogenic genes in white adipose tissues (WAT) of Hspa12a−/− mice were also attenuated. Loss- and gain-of-function studies revealed that the differentiation of primary adipocyte precursors, as well as the expression of PPARγ and target adipogenic genes during the differentiation, was suppressed by HSPA12A deficiency whereas promoted by HSPA12A overexpression. Importantly, PPARγ inhibition by GW9662 reversed the HSPA12A-mediated adipocyte differentiation. On the other hand, HSPA12A expression was downregulated by PPARγ inhibition but upregulated by PPARγ activation in primary adipocytes. A direct binding of PPARγ to the PPAR response element in the Hspa12a promoter region was confirmed by chromatin immunoprecipitation assay, and this binding was increased after differentiation of primary adipocytes. These findings indicate that HSPA12A is a novel regulator of adipocyte differentiation and diet-induced obesity through a positive feedback regulation with PPARγ. HSPA12A inhibition might represent a viable strategy for the management of obesity in humans

    Baicalein Inhibits IL-1β- and TNF-α-Induced Inflammatory Cytokine Production From Human Mast Cells via Regulation of the NF-κB Pathway

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    Background: Human mast cells are multifunctional cells capable of a wide variety of inflammatory responses. Baicalein (BAI), isolated from the traditional Chinese herbal medicine Huangqin (Scutellaria baicalensis Georgi), has been shown to have anti-inflammatory effects. We examined its effects and mechanisms on the expression of inflammatory cytokines in an IL-1β- and TNF-α-activated human mast cell line, HMC-1. Methods: HMC-1 cells were stimulated either with IL-1β (10 ng/ml) or TNF-α (100 U/ml) in the presence or absence of BAI. We assessed the expression of IL-6, IL-8, and MCP-1 by ELISA and RT-PCR, NF-κB activation by electrophoretic mobility shift assay (EMSA), and IκBα activation by Western blot. Results: BAI (1.8 to 30 μM) significantly inhibited production of IL-6, IL-8, and MCP-1 in a dose-dependent manner in IL-1β-activated HMC-1. BAI (30 μM) also significantly inhibited production of IL-6, IL-8, and MCP-1 in TNF-α-activated HMC-1. Inhibitory effects appear to involve the NF-κB pathway. BAI inhibited NF-κB activation in IL-1β- and TNF-α-activated HMC-1. Furthermore, BAI increased cytoplasmic IκBα proteins in IL-1β- and TNF-α-activated HMC-1. Conclusion: Our results showed that BAI inhibited the production of inflammatory cytokines through inhibition of NF-κB activation and IκBα phosphorylation and degradation in human mast cells. This inhibitory effect of BAI on the expression of inflammatory cytokines suggests its usefulness in the development of novel anti-inflammatory therapies

    Lactate and Immunosuppression in Sepsis

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    Serum lactate levels are traditionally interpreted as a marker of tissue hypoxia and often used clinically as an indicator of severity and outcome of sepsis/septic shock. Interestingly, recent studies involving the effects of tumor-derived lactate suggest that lactate itself may have an immunosuppressive effect in its local environment. This finding adds to the recent advances in immunometabolism that shed light on the importance of metabolism and metabolic intermediates in the regulation of innate immune and inflammatory responses in sepsis. In this article, we summarize recent studies, showing that the activation of immune cells requires aerobic glycolytic metabolism and that lactate produced by aerobic glycolysis may play an immunosuppressive role in sepsis
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