FTY720 alleviates coxsackievirus B3-induced myocarditis and inhibits viral replication through regulating sphingosine 1-phosphate receptors and AKT/caspase-3 pathways.

Fingolimod (FTY720) after phosphorylation, as the ligand of sphingosine 1-phosphate receptors (S1PRs), plays an important role in cell proliferation and differentiation. In this article, FTY720 in the treatment of coxsackievirus B3 (CVB3)-induced viral myocarditis was closely related to apoptosis and AKT/caspase-3 apoptotic pathways. We found that CVB3 inhibited myocardial apoptosis at the early stage with upregulating p-AKT level and downregulating activated caspase-3 level for replication of virus progeny, whereas it promoted apoptosis at a late stage with downregulating p-AKT and upregulating activated caspase-3 for releasing the newly synthesized virus to spread. Interestingly, FTY720 could reverse this trend; it promoted apoptosis at an early stage and inhibited apoptosis at the late stage in vivo and vitro, which proved the antiviral effect. We also found that S1PR1, S1PR4, and S1PR5, rather than S1PR2 and S1PR3, were regulated by FTY720 in this process. The results confirmed that FTY720 alleviates CVB3-induced myocarditis and inhibits viral replication through regulating S1PRs and AKT/caspase-3 pathways with a bidirectional regulation of apoptosis.

LAP+ Treg is a better biomarker than total Treg in viral myocarditis.

Latency associated peptide (LAP) is a protein expressed on the membrane of some regulatory T cells (Treg). LAP+ Treg have a greater immunomodulatory effect than that of their negative counterparts. In this study, we presented the data on the proportion of LAP+ Treg out of CD4+ cells in mice with viral myocarditis, which we believed was more sensitive and specific than that of the ratio of total Treg in CD4+ cells. Comparing with the previously recognized total Treg, LAP+ Treg was a better biomarker on myocardial inflammation.

IgE Downregulates PTEN through MicroRNA-21-5p and Stimulates Airway Smooth Muscle Cell Remodeling.

The patho-mechanism leading to airway wall remodeling in allergic asthma is not well understood and remodeling is resistant to therapies. This study assessed the effect of immunoglobulin E (IgE) in the absence of allergens on human primary airway smooth muscle cell (ASMC) remodeling in vitro. ASMCs were obtained from five allergic asthma patients and five controls. Proliferation was determined by direct cell counts, mitochondrial activity by expression of cytochrome c, protein expression by immunoblotting and immuno-fluorescence, cell migration by microscopy imaging, and collagen deposition by cell based ELISA and RNA expression by real time PCR. Non-immune IgE activated two signaling pathways: (i) signal transducer and activator of transcription 3 (STAT3)→miR-21-5p→downregulating phosphatase and tensin homolog (PTEN) expression, and (ii) phosphatidylinositol 3-kinases (PI3K)→protein kinase B (Akt)→mammalian target of rapamycin (mTOR)→ribosomal protein S6 kinase beta-1 (p70s6k)→peroxisome proliferator-activated receptor gamma coactivator 1-α (PGC1-α)→peroxisome proliferator-activated receptor-γ (PPAR-γ)→cyclooxygenase-2 (COX-2)→mitochondrial activity, proliferation, migration, and extracellular matrix deposition. Reduced PTEN expression correlated with enhanced PI3K signaling, which upregulated ASMC remodeling. The inhibition of microRNA-21-5p increased PTEN and reduced mTOR signaling and remodeling. Mimics of microRNA-21-5p had opposing effects. IgE induced ASMC remodeling was significantly reduced by inhibition of mTOR or STAT3. In conclusion, non-immune IgE alone is sufficient for stimulated ASMC remodeling by upregulating microRNA-21-5p. Our findings suggest that the suppression of micoRNA-21-5p may present a therapeutic target to reduce airway wall remodeling.

HECTD1 controls the protein level of IQGAP1 to regulate the dynamics of adhesive structures.

BACKGROUND: Cell migration including collective cell movement and individual cell migration are crucial factors in embryogenesis. During the spreading/migration of cells, several types of adhesive structures physically interacting with the extracellular matrix (ECM) or with another cell have been described and the formation and maturation of adhesion structures are coordinated, however the molecular pathways involved are still not fully understood. RESULTS: We generated a mouse embryonic fibroblast line (MEF) from homozygous mutant (Hectd1 R/R , Hectd1 Gt(RRC200) ) mouse of the E3 ubiquitin ligase for inhibin B receptor (Hectd1). Detailed examination of cell motion on MEF cells demonstrated that loss of Hectd1 resulted in accelerated cell spreading and migration but impaired directionality of migration. In Hectd1 R/R cells paxillin and zyxin were largely mis-localized, whereas their expression levels were unchanged. In addition the formation of focal adhesions (FAs) was impaired and the focal complexes (FXs) were increased. We further identified HECTD1 as a key regulator of IQGAP1. IQGAP1 co-localized together with HECTD1 in the leading edge of cells. HECTD1 interacted with IQGAP1 and regulated its degradation through ubiquitination. Over-expression of IQGAP1 in control MEF phenocopied the spreading and migration defects of Hectd1 R/R cells. In contrast, siRNA-mediated knockdown of IQGAP1 rescued the defects in cellular movement of Hectd1 R/R cells. CONCLUSIONS: The E3 ligase activity of Hectd1 regulates the protein level of IQGAP1 through ubiquitination and therefore mediates the dynamics of FXs including the recruitment of paxillin and actinin. IQGAP1 is one of the effectors of HECTD1.

Sphingosine 1-phosphate alleviates Coxsackievirus B3-induced myocarditis by increasing invariant natural killer T cells.

Sphingosine 1-phosphate (S1P), via binding to its specific receptors of S1PR1, participates in the regulation of both innate and adaptive immunity. Recent reports have identified S1P as a messenger mediating inflammation. However, roles of S1P in Coxsackievirus B3 (CVB3)-induced myocarditis were largely unknown. Here, we investigated the effect of S1P treatment on CVB3-induced myocarditis in vivo. We found that CVB3 infection downregulated S1PR1 expression in spleen and decreased the proportion of invariant natural killer T cells (iNKT) in CD3 positive T cells both in spleen and in blood from left ventricle, which accompanied by severe inflammation lesions and more virus capsid protein (VP1) expression in heart tissue. In comparison, S1P supply upregulated iNKT in the spleen and in blood from left ventricle, which represented the strengthening of anti-inflammatory effects. Indeed, inflammation infiltration, VP1 expression and apoptosis in the myocardium was all downregulated. These results demonstrated that S1P supplement could alleviate CVB3-induced myocarditis.

Robust subspace discovery via relaxed rank minimization.

This letter examines the problem of robust subspace discovery from input data samples (instances) in the presence of overwhelming outliers and corruptions. A typical example is the case where we are given a set of images; each image contains, for example, a face at an unknown location of an unknown size; our goal is to identify or detect the face in the image and simultaneously learn its model. We employ a simple generative subspace model and propose a new formulation to simultaneously infer the label information and learn the model using low-rank optimization. Solving this problem enables us to simultaneously identify the ownership of instances to the subspace and learn the corresponding subspace model. We give an efficient and effective algorithm based on the alternating direction method of multipliers and provide extensive simulations and experiments to verify the effectiveness of our method. The proposed scheme can also be used to tackle many related high-dimensional combinatorial selection problems.

Investigation of interface states in single-negative metamaterial layered structures based on the phase properties.

The physical mechanism of the interface states in layered structures consisting of single-negative metamaterials is investigated using a simple resonant cavity model. We found that the interface states and their corresponding tunneling transmission modes appeared when the resonant condition is satisfied. Such resonant condition depends on the phase changes inside the resonant cavity. Based on these results, we proposed an efficient method to precisely predict the frequencies of the tunneling interface states inside the single-negative metamaterial layers. Our method is effective for interface states corresponding to perfect or imperfect tunneling transmission. Composite right/left-handed transmission lines were used to realize the pair and sandwich metamaterial layered structures in the microwave region. Electromagnetic tunneling interface states were observed in the measurements, which agreed well with the theory. Our study offers a way for effectively designing metamaterial devices with novel electromagnetic tunneling properties.

Shear stress inhibits apoptosis of ischemic brain microvascular endothelial cells.

As a therapeutic strategy for ischemic stroke, to restore or increase cerebral blood flow (CBF) is the most fundamental option. Laminar shear stress (LS), as an important force generated by CBF, mainly acts on brain microvascular endothelial cells (BMECs). In order to study whether LS was a protective factor in stroke, we investigated LS-intervented ischemic apoptosis of rat BMECs (rBMECs) through PE Annexin V/7-AAD, JC-1 and Hoechst 33258 staining to observe the membranous, mitochondrial and nuclear dysfunction. Real-time PCR and western blot were also used to test the gene and protein expressions of Tie-2, Bcl-2 and Akt, which were respectively related to maintain membranous, mitochondrial and nuclear norm. The results showed that LS could be a helpful stimulus for ischemic rBMECs survival. Simultaneously, membranous, mitochondrial and nuclear regulation played an important role in this process.

What Makes for Hierarchical Vision Transformer?

Recent studies indicate that hierarchical Vision Transformer (ViT) with a macro architecture of interleaved non-overlapped window-based self-attention & shifted-window operation can achieve state-of-the-art performance in various visual recognition tasks, and challenges the ubiquitous convolutional neural networks (CNNs) using densely slid kernels. In most recently proposed hierarchical ViTs, self-attention is the de-facto standard for spatial information aggregation. In this paper, we question whether self-attention is the only choice for hierarchical ViT to attain strong performance, and study the effects of different kinds of cross-window communication methods. To this end, we replace self-attention layers with embarrassingly simple linear mapping layers, and the resulting proof-of-concept architecture termed TransLinear can achieve very strong performance in ImageNet-[Formula: see text] image recognition. Moreover, we find that TransLinear is able to leverage the ImageNet pre-trained weights and demonstrates competitive transfer learning properties on downstream dense prediction tasks such as object detection and instance segmentation. We also experiment with other alternatives to self-attention for content aggregation inside each non-overlapped window under different cross-window communication approaches. Our results reveal that the macro architecture, other than specific aggregation layers or cross-window communication mechanisms, is more responsible for hierarchical ViT's strong performance and is the real challenger to the ubiquitous CNN's dense sliding window paradigm.

VoxelTrack: Multi-Person 3D Human Pose Estimation and Tracking in the Wild.

We present VoxelTrack for multi-person 3D pose estimation and tracking from a few cameras which are separated by wide baselines. It employs a multi-branch network to jointly estimate 3D poses and re-identification (Re-ID) features for all people in the environment. In contrast to previous efforts which require to establish cross-view correspondence based on noisy 2D pose estimates, it directly estimates and tracks 3D poses from a 3D voxel-based representation constructed from multi-view images. We first discretize the 3D space by regular voxels and compute a feature vector for each voxel by averaging the body joint heatmaps that are inversely projected from all views. We estimate 3D poses from the voxel representation by predicting whether each voxel contains a particular body joint. Similarly, a Re-ID feature is computed for each voxel which is used to track the estimated 3D poses over time. The main advantage of the approach is that it avoids making any hard decisions based on individual images. The approach can robustly estimate and track 3D poses even when people are severely occluded in some cameras. It outperforms the state-of-the-art methods by a large margin on four public datasets including Shelf, Campus, Human3.6 M and CMU Panoptic.

CCNet: Criss-Cross Attention for Semantic Segmentation.

Contextual information is vital in visual understanding problems, such as semantic segmentation and object detection. We propose a criss-cross network (CCNet) for obtaining full-image contextual information in a very effective and efficient way. Concretely, for each pixel, a novel criss-cross attention module harvests the contextual information of all the pixels on its criss-cross path. By taking a further recurrent operation, each pixel can finally capture the full-image dependencies. Besides, a category consistent loss is proposed to enforce the criss-cross attention module to produce more discriminative features. Overall, CCNet is with the following merits: 1) GPU memory friendly. Compared with the non-local block, the proposed recurrent criss-cross attention module requires 11× less GPU memory usage. 2) High computational efficiency. The recurrent criss-cross attention significantly reduces FLOPs by about 85 percent of the non-local block. 3) The state-of-the-art performance. We conduct extensive experiments on semantic segmentation benchmarks including Cityscapes, ADE20K, human parsing benchmark LIP, instance segmentation benchmark COCO, video segmentation benchmark CamVid. In particular, our CCNet achieves the mIoU scores of 81.9, 45.76 and 55.47 percent on the Cityscapes test set, the ADE20K validation set and the LIP validation set respectively, which are the new state-of-the-art results. The source codes are available at https://github.com/speedinghzl/CCNethttps://github.com/speedinghzl/CCNet.

Condition-Adaptive Graph Convolution Learning for Skeleton-Based Gait Recognition.

Graph convolutional networks have been widely applied in skeleton-based gait recognition. A key challenge in this task is to distinguish the individual walking styles of different subjects across various views. Existing state-of-the-art methods employ uniform convolutions to extract features from diverse sequences and ignore the effects of viewpoint changes. To overcome these limitations, we propose a condition-adaptive graph (CAG) convolution network that can dynamically adapt to the specific attributes of each skeleton sequence and the corresponding view angle. In contrast to using fixed weights for all joints and sequences, we introduce a joint-specific filter learning (JSFL) module in the CAG method, which produces sequence-adaptive filters at the joint level. The adaptive filters capture fine-grained patterns that are unique to each joint, enabling the extraction of diverse spatial-temporal information about body parts. Additionally, we design a view-adaptive topology learning (VATL) module that generates adaptive graph topologies. These graph topologies are used to correlate the joints adaptively according to the specific view conditions. Thus, CAG can simultaneously adjust to various walking styles and viewpoints. Experiments on the two most widely used datasets (i.e., CASIA-B and OU-MVLP) show that CAG surpasses all previous skeleton-based methods. Moreover, the recognition performance can be enhanced by simply combining CAG with appearance-based methods, demonstrating the ability of CAG to provide useful complementary information.

ADSeg: A flap-attention-based deep learning approach for aortic dissection segmentation.

Accurate and rapid segmentation of the lumen in an aortic dissection (AD) is an important prerequisite for risk evaluation and medical planning for patients with this serious condition. Although some recent studies have pioneered technical advances for the challenging AD segmentation task, they generally neglect the intimal flap structure that separates the true and false lumens. Identification and segmentation of the intimal flap may simplify AD segmentation, and the incorporation of long-distance z axis information interaction along the curved aorta may improve segmentation accuracy. This study proposes a flap attention module that focuses on key flap voxels and performs operations with long-distance attention. In addition, a pragmatic cascaded network structure with feature reuse and a two-step training strategy are presented to fully exploit network representation power. The proposed ADSeg method was evaluated on a multicenter dataset of 108 cases, with or without thrombus; ADSeg outperformed previous state-of-the-art methods by a significant margin and was robust against center variation.

Focalizing regions of biomarker relevance facilitates biomarker prediction on histopathological images.

Image-based AI has thrived as a potentially revolutionary tool for predicting molecular biomarker statuses, which aids in categorizing patients for appropriate medical treatments. However, many methods using hematoxylin and eosin-stained (H&E) whole-slide images (WSIs) have been found to be inefficient because of the presence of numerous uninformative or irrelevant image patches. In this study, we introduced the region of biomarker relevance (ROB) concept to identify the morphological areas most closely associated with biomarkers for accurate status prediction. We actualized this concept within a framework called saliency ROB search (SRS) to enable efficient and effective predictions. By evaluating various lung adenocarcinoma (LUAD) biomarkers, we showcased the superior performance of SRS compared to current state-of-the-art AI approaches. These findings suggest that AI tools, built on the ROB concept, can achieve enhanced molecular biomarker prediction accuracy from pathological images.

Long-term reproductive consequences of no-scalpel vasectomy in beagles.

The effects of vasectomy on the reproductive organs in various species are controversial. This study investigated the morphological change and apoptosis of the testis, epididymis, and vas deferens in beagle dogs 12 months after vasectomy. The male beagles were divided into two groups: vasectomized and sham-operated groups (n=5 in each). Histopathological, ultrastructural, and TUNEL evaluation of the changes in the testis, epididymis, and ductus deferens of each animal were conducted 12 months after surgery. The mean lumen diameter, cellular thickness, mean interstitial distance, and lumen area fraction of each seminiferous tubule and ductus epididymis were measured by stereological analysis. The results showed that, compared with the sham-operated group, the seminiferous tubular epithelial cells of the testes in the vasectomized group were disorderly arranged and scattered. Significant atrophy and apoptosis were found in the endothelial cells, and a range of ultrastructural variations were observed in the cells of testes, epididymis, and vas deferens in vasectomized group. It was concluded that complete obstruction of the vas deferens as a traditional contraception method is not absolutely safe in terms of the reversal of fertility in the long run. Techniques of relieving the inner pressure in the vas deferens while maintaining the efficacy of male contraception need to be explored.

[Role of triggering receptor expressed on myeloid cells-1 on coxsackievirus B3-induced inflammation and cardiomyocyte injury].

OBJECTIVE: To determine the expression of TREM-1 (triggering receptor expressed on myeloid cells-1) in macrophages after coxsackievirus B3 (CVB3) infection and the cardiomyocytes viability after culturing with supernatant of macrophages in the absence and presence of TREM-1 inhibitor LP-17 to explore if TREM-1 is involved in the pathogenesis of CVB3 infection induced inflammation and cardiomyocytes injury. METHODS: TREM-1 mRNA and TREM-1 and DAP-12 protein expression in macrophages were detected by Real-time PCR at 0, 1, 4, 8 and 12 h and by Western blot at 0, 16, 24 and 48 h post CVB3 infection. TNF-α secretion of macrophages was measure by ELISA, vitality and the apoptosis degree of cardiomyocytes was assessed by CCK8 and Annexin V-FITC after the cardiomyocytes were cultured with the supernatant of macrophages in normal control group, CVB3 infection group and LP-17 pretreated CVB3 infection group. RESULTS: TREM-1 mRNA expression was significantly upregulated at 4, 8, and 12 h (peaked at 8 h) and TREM-1 protein expression was significantly upregulated at 16 and 24 h and returned to baseline level at 48 h after CVB3 infection. The protein expression of DAP-12, a direct downstream signaling molecule of TREM-1, also significantly increased at 24 and 48 h post CVB3 infection (P < 0.01). Level of macrophages secreted TNF-α post CVB3 infection was significantly reduced in LP-17 pretreated cells (P < 0.01), LP-17 pretreatment also significantly improved viability and significantly reduced apoptosis of cardiomyocytes cultured with supernatant of CVB3 infected macrophages (P < 0.01). CONCLUSION: TREM-1 might be an important mediator post CVB3 infection and a major player on inducing excess macrophages-related inflammation and resulting in an indirect injury to cardiomyocytes.

Downregulation of PLK4 expression induces apoptosis and G0/G1-phase cell cycle arrest in keloid fibroblasts.

OBJECTIVES: Keloids are benign fibroproliferative tumors that display many cancer-like characteristics, such as progressive uncontrolled growth, lack of spontaneous regression, and extremely high rates of recurrence. Polo-like kinase 4 (PLK4) was recently identified as a master regulator of centriole replication, and its aberrant expression is closely associated with tumorigenesis. This study aimed to investigate the expression and biological role of PLK4 in the pathogenesis of keloids. MATERIALS AND METHODS: We evaluated the expression of PLK4 in keloids and adjacent normal skin tissue samples. Then, we established PLK4 knockdown and overexpression cell lines in keloid fibroblasts (KFs) and normal skin fibroblasts (NFs), respectively, to investigate the roles of PLK4 in the regulation of proliferation, migration, invasion, apoptosis, and cell cycle in KFs. Centrinone B (Cen-B), a highly selective PLK4 inhibitor, was used to inhibit PLK4 activity in KFs to evaluate the therapeutic effect on KFs. RESULTS: We discovered that PLK4 was overexpressed in keloid dermal samples and KFs compared with adjacent normal skin samples and NFs derived from the same patients. High PLK4 expression was positively associated with the proliferation, migration, and invasion of KFs. Furthermore, knockdown of PLK4 expression or inhibition of PLK4 activity by Cen-B suppressed KF growth, induced KF apoptosis via the caspase-9/3 pathway, and induced cell cycle arrest at the G0/G1 phase in vitro. CONCLUSIONS: These findings demonstrate that PLK4 is a critical regulator of KF proliferation, migration, and invasion, and thus, Cen-B is a promising candidate drug for keloid treatment.