A structural variation in the promoter of the leucoanthocyanidin reductase gene AaLAR1 enhances freezing tolerance by modulating proanthocyanidin accumulation in kiwifruit (Actinidia arguta).

Proanthocyanidins (PAs) are important metabolites that enhance freezing tolerance of plants. Actinidia arguta, especially freezing-tolerant germplasms, accumulate abundant PAs in dormant shoots and thereby enhance freezing tolerance, but the underlying mechanism is unknown. In this study, we used two A. arguta with contrasting cold-resistant phenotypes, KL and RB, to explore the mechanisms in response to cold tolerance. We determined that a leucoanthocyanidin reductase gene (AaLAR1) was more highly expressed in freezing-tolerant KL than in freezing-sensitive RB. Moreover, overexpressing AaLAR1 in kiwifruit promoted PAs biosynthesis and enhanced cold tolerance. The AaLAR1 promoters of various A. arguta germplasms differ due to the presence of a 60-bp deletion in cold-tolerant genotypes that forms a functional binding site for MYC-type transcription factor. Yeast one-hybrid and two-hybrid, dual-luciferase reporter, bimolecular fluorescence complementation and coimmunoprecipitation assays indicated that the AaMYC2a binds to the MYC-core cis-element in the AaLAR1 promoter with the assistance of AaMYB5a, thereby promoting PAs accumulation in the shoots of cold-tolerant kiwifruit. We conclude that the variation in the AaLAR1 promoter and the AaMYC2a-AaMYB5a-AaLAR1 module shape freezing tolerance in A. arguta. The identification of a key structural variation in the AaLAR1 promoter offers a new target for resistance breeding of kiwifruit.

Piezo1 (Piezo-Type Mechanosensitive Ion Channel Component 1)-Mediated Mechanosensation in Macrophages Impairs Perfusion Recovery After Hindlimb Ischemia in Mice.

BACKGROUND: Angiogenesis is a promising strategy for those with peripheral artery disease. Macrophage-centered inflammation is intended to govern the deficiency of the angiogenic response after hindlimb ischemia. However, little is known about the mechanism of macrophage activation beyond signals from cytokines and chemokines. We sought to identify a novel mechanical signal from the ischemic microenvironment that provokes macrophages and the subsequent inflammatory cascade and to investigate the potential role of Piezo-type mechanosensitive ion channels (Piezo) on macrophages during this process. METHODS: Myeloid cell-specific Piezo1 (Piezo-type mechanosensitive ion channel component 1) knockout (Piezo1ΔMΦ) mice were generated by crossing Piezo1fl/fl (LysM-Cre-/-; Piezo1 flox/flox) mice with LysM-Cre transgenic mice to assess the roles of Piezo1 in macrophages after hindlimb ischemia. Furthermore, in vitro studies were carried out in bone marrow-derived macrophages to decipher the underlying mechanism. RESULTS: We found that tissue stiffness gradually increased after hindlimb ischemia, as indicated by Young's modulus. Compared to Piezo2, Piezo1 expression and activation were markedly upregulated in macrophages from ischemic tissues in concurrence with increased tissue stiffness. Piezo1ΔMΦ mice exhibited improved perfusion recovery by enhancing angiogenesis. Matrigel tube formation assays revealed that Piezo1 deletion promoted angiogenesis by enhancing FGF2 (fibroblast growth factor-2) paracrine signaling in macrophages. Conversely, activation of Piezo1 by increased stiffness or the agonist Yoda1 led to reduced FGF2 production in bone marrow-derived macrophages, which could be blocked by Piezo1 silencing. Mechanistically, Piezo1 mediated extracellular Ca2+ influx and activated Ca2+-dependent CaMKII (calcium/calmodulin-dependent protein kinase II)/ETS1 (ETS proto-oncogene 1) signaling, leading to transcriptional inactivation of FGF2. CONCLUSIONS: This study uncovers a crucial role of microenvironmental stiffness in exacerbating the macrophage-dependent deficient angiogenic response. Deletion of macrophage Piezo1 promotes perfusion recovery after hindlimb ischemia through CaMKII/ETS1-mediated transcriptional activation of FGF2. This provides a promising therapeutic strategy to enhance angiogenesis in ischemic diseases.

Neonatal resveratrol administration promotes skeletal muscle growth and insulin sensitivity in intrauterine growth-retarded suckling piglets associated with activation of FGF21-AMPKα pathway.

BACKGROUND: Skeletal muscle is a major insulin-sensitive tissue with a pivotal role in modulating glucose homeostasis. This study aimed to investigate the effect of resveratrol (RES) intervention during the suckling period on skeletal muscle growth and insulin sensitivity of neonates with intrauterine growth retardation (IUGR) in a pig model. RESULTS: Twelve pairs of normal birth weight (NBW) and IUGR neonatal male piglets were selected. The NBW and IUGR piglets were fed basal formula milk diet or identical diet supplemented with 0.1% RES from 7 to 21 days of age. Myofiber growth and differentiation, inflammation and insulin sensitivity in skeletal muscle were assessed. Early RES intervention promoted myofiber growth and maturity in IUGR piglets by ameliorating the myogenesis process and increasing thyroid hormone level. Administering RES also reduced triglyceride concentration in skeletal muscle of IUGR piglets, along with decreased inflammatory response, increased plasma fibroblast growth factor 21 (FGF21) concentration and improved insulin signaling. Meanwhile, the improvement of insulin sensitivity by RES may be partly regulated by activation of the FGF21/AMP-activated protein kinase α/sirtuin 1/peroxisome proliferator activated receptor-γ coactivator-1α pathway. CONCLUSION: Our results suggest that RES has beneficial effects in promoting myofiber growth and maturity and increasing skeletal muscle insulin sensitivity in IUGR piglets, which open a novel field of application of RES in IUGR infants for improving postnatal metabolic adaptation. © 2023 Society of Chemical Industry.

Physiological Characteristics and Transcriptome Analysis of Exogenous Brassinosteroid-Treated Kiwifruit.

Brassinosteroids (BRs) play pivotal roles in improving plant stress tolerance. To investigate the mechanism of BR regulation of salt tolerance in kiwifruit, we used 'Hongyang' kiwifruit as the test material. We exposed the plants to 150 mmol/L NaCl stress and irrigated them with exogenous BR (2,4-epibrassinolide). The phenotypic analysis showed that salt stress significantly inhibited photosynthesis in kiwifruit, leading to a significant increase in the H2O2 content of leaves and roots and a significant increase in Na+/K+, resulting in oxidative damage and an ion imbalance. BR treatment resulted in enhanced photosynthesis, reduced H2O2 content, and reduced Na+/K+ in leaves, alleviating the salt stress injury. Furthermore, transcriptome enrichment analysis showed that the differentially expressed genes (DEGs) related to BR treatment are involved in pathways such as starch and sucrose metabolism, pentose and glucuronate interconversions, and plant hormone signal transduction, among others. Among the DEGs involved in plant hormone signal transduction, those with the highest expression were involved in abscisic acid signal transduction. Moreover, there was a significant increase in the expression of the AcHKT1 gene, which regulates ion transduction, and the antioxidant enzyme AcFSD2 gene, which is a key gene for improving salt tolerance. The data suggest that BRs can improve salt tolerance by regulating ion homeostasis and reducing oxidative stress.

Knockdown of estrogen-related receptor α inhibits valve interstitial cell calcification in vitro by regulating heme oxygenase 1.

Calcific aortic valve disease (CAVD) is the most common valvular heart disease in adults. The cellular mechanisms of CAVD are still unknown, but accumulating evidence has revealed that osteogenic differentiation of human valve interstitial cells (hVICs) plays an important role in CAVD. Thus, we aimed to investigate the function of estrogen-related receptor α (ERRα) in the osteogenic differentiation of hVICs. We found that the level of ERRα was significantly increased in CAVD samples compared to normal controls. In addition, ERRα was significantly upregulated during hVIC osteogenic differentiation in vitro. Gain- and loss-of-function experiments were performed to identify the function of ERRα in hVIC calcification in vitro. Inhibition of endogenous ERRα attenuated hVIC calcification, whereas overexpression of ERRα in hVICs promoted this process. RNA sequencing results suggested that heme oxygenase-1 (Hmox1) was a downstream target of ERRα, which was further confirmed by western blotting. Additionally, we also found that downregulation of Hmox1 by shHmox1 efficiently reversed the inhibition of calcification induced by ERRα shRNA in hVICs. ChIP-qPCR and luciferase assays indicated that Hmox1 was negatively regulated by ERRα. We found that overexpression of Hmox1 or its substrates significantly inhibited hVIC calcification in vitro. In conclusion, we found that knockdown of ERRα can inhibit hVIC calcification through upregulating Hmox1 and that ERRα and Hmox1 are potential targets for the treatment of CAVD.

Low-Light Image Enhancement Based on Constraint Low-Rank Approximation Retinex Model.

Images captured in a low-light environment are strongly influenced by noise and low contrast, which is detrimental to tasks such as image recognition and object detection. Retinex-based approaches have been continuously explored for low-light enhancement. Nevertheless, Retinex decomposition is a highly ill-posed problem. The estimation of the decomposed components should be combined with proper constraints. Meanwhile, the noise mixed in the low-light image causes unpleasant visual effects. To address these problems, we propose a Constraint Low-Rank Approximation Retinex model (CLAR). In this model, two exponential relative total variation constraints were imposed to ensure that the illumination is piece-wise smooth and that the reflectance component is piece-wise continuous. In addition, the low-rank prior was introduced to suppress the noise in the reflectance component. With a tailored separated alternating direction method of multipliers (ADMM) algorithm, the illumination and reflectance components were updated accurately. Experimental results on several public datasets verify the effectiveness of the proposed model subjectively and objectively.

Overexpression of AcEXPA23 Promotes Lateral Root Development in Kiwifruit.

Kiwifruit is loved by consumers for its unique taste and rich vitamin C content. Kiwifruit are very sensitive to adverse soil environments owing to fleshy and shallow roots, which limits the uptake of water and nutrients into the root system, resulting in low yield and poor fruit quality. Lateral roots are the key organs for plants to absorb water and nutrients. Improving water and fertilizer use efficiency by promoting lateral root development is a feasible method to improve yield and quality. Expansin proteins plays a major role in lateral root growth; hence, it is important to identify expansin protein family members, screen key genes, and explore gene function in root development. In this study, 41 expansin genes were identified based on the genome of kiwifruit ('Hongyang', Actinidia chinensis). By clustering with the Arabidopsis thaliana expansin protein family, the 41 AcExpansin proteins were divided into four subfamilies. The AcExpansin protein family was further analysed by bioinformatics methods and was shown to be evolutionarily diverse and conserved at the DNA and protein levels. Based on previous transcriptome data and quantitative real-time PCR assays, we screened the candidate gene AcEXPA23. Overexpression of AcEXPA23 in kiwifruit increased the number of kiwifruit lateral roots.

Aldo-keto reductase family 1 member B induces aortic valve calcification by activating hippo signaling in valvular interstitial cells.

AIMS: Calcific aortic valve disease (CAVD) is a primary cause of cardiovascular mortality; however, its mechanisms are unknown. Currently, no effective pharmacotherapy is available for CAVD. Aldo-keto reductase family 1 member B (Akr1B1) has been identified as a potential therapeutic target for valve interstitial cell calcification. Herein, we hypothesized that inhibition of Akr1B1 can attenuate aortic valve calcification. METHODS AND RESULTS: Normal and degenerative tricuspid calcific valves from human samples were analyzed by immunoblotting and immunohistochemistry. The results showed significant upregulation of Akr1B1 in CAVD leaflets. Akr1B1 inhibition attenuated calcification of aortic valve interstitial cells in osteogenic medium. In contrast, overexpression of Akr1B1 aggravated calcification in osteogenic medium. Mechanistically, using RNA sequencing (RNAseq), we revealed that Hippo-YAP signaling functions downstream of Akr1B1. Furthermore, we established that the protein level of the Hippo-YAP signaling effector active-YAP had a positive correlation with Akr1B1. Suppression of YAP reversed Akr1B1 overexpression-induced Runx2 upregulation. Moreover, YAP activated the Runx2 promoter through TEAD1 in a manner mediated by ChIP and luciferase reporter systems. Animal experiments showed that the Akr1B1 inhibitor epalrestat attenuated aortic valve calcification induced by a Western diet in LDLR-/- mice. CONCLUSION: This study demonstrates that inhibition of Akr1B1 can attenuate the degree of calcification both in vitro and in vivo. The Akr1B1 inhibitor epalrestat may be a potential treatment option for CAVD.

Improvement in Signal-to-Noise Ratio of Liquid-State NMR Spectroscopy via a Deep Neural Network DN-Unet.

Nuclear magnetic resonance (NMR) is one of the most powerful analytical tools and is extensively applied in many fields. However, compared to other spectroscopic techniques, NMR has lower sensitivity, impeding its wider applications. Using data postprocessing techniques to increase the NMR spectral signal-to-noise ratio (SNR) is a relatively simple and cost-effective method. In this work, a deep neural network, termed as DN-Unet, is devised to suppress noise in liquid-state NMR spectra to enhance SNR. It combines structures of encoder-decoder and convolutional neural network. Different from traditional deep learning training strategy, M-to-S strategy is developed to enhance DN-Unet capability that multiple noisy spectra (inputs) correspond to a same single noiseless spectrum (label) in the training stage. The trained 1D model can be used for denoising not only 1D but also high dimension spectra, further improving DN-Unet's performance. 1D, 2D, and 3D NMR spectra were utilized to evaluate DN-Unet performance. The results suggest that DN-Unet provides larger than 200-fold increase in SNR with weak peaks hidden in noise perfectly recovered and spurious peaks suppressed well. Since DN-Unet developed here to increase SNR is based on data postprocessing, it is universal for a variety of samples and NMR platforms. The great SNR enhancement and extreme excellence in differentiating signal and noise would greatly promote various liquid-state NMR applications.

Full-length transcriptome profiling reveals insight into the cold response of two kiwifruit genotypes (A. arguta) with contrasting freezing tolerances.

BACKGROUND: Kiwifruit (Actinidia Lindl.) is considered an important fruit species worldwide. Due to its temperate origin, this species is highly vulnerable to freezing injury while under low-temperature stress. To obtain further knowledge of the mechanism underlying freezing tolerance, we carried out a hybrid transcriptome analysis of two A. arguta (Actinidi arguta) genotypes, KL and RB, whose freezing tolerance is high and low, respectively. Both genotypes were subjected to - 25 °C for 0 h, 1 h, and 4 h. RESULTS: SMRT (single-molecule real-time) RNA-seq data were assembled using the de novo method, producing 24,306 unigenes with an N50 value of 1834 bp. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of DEGs showed that they were involved in the 'starch and sucrose metabolism', the 'mitogen-activated protein kinase (MAPK) signaling pathway', the 'phosphatidylinositol signaling system', the 'inositol phosphate metabolism', and the 'plant hormone signal transduction'. In particular, for 'starch and sucrose metabolism', we identified 3 key genes involved in cellulose degradation, trehalose synthesis, and starch degradation processes. Moreover, the activities of beta-GC (beta-glucosidase), TPS (trehalose-6-phosphate synthase), and BAM (beta-amylase), encoded by the abovementioned 3 key genes, were enhanced by cold stress. Three transcription factors (TFs) belonging to the AP2/ERF, bHLH (basic helix-loop-helix), and MYB families were involved in the low-temperature response. Furthermore, weighted gene coexpression network analysis (WGCNA) indicated that beta-GC, TPS5, and BAM3.1 were the key genes involved in the cold response and were highly coexpressed together with the CBF3, MYC2, and MYB44 genes. CONCLUSIONS: Cold stress led various changes in kiwifruit, the 'phosphatidylinositol signaling system', 'inositol phosphate metabolism', 'MAPK signaling pathway', 'plant hormone signal transduction', and 'starch and sucrose metabolism' processes were significantly affected by low temperature. Moreover, starch and sucrose metabolism may be the key pathway for tolerant kiwifruit to resist low temperature damages. These results increase our understanding of the complex mechanisms involved in the freezing tolerance of kiwifruit under cold stress and reveal a series of candidate genes for use in breeding new cultivars with enhanced freezing tolerance.

High-resolution 2-D NMR spectroscopy based on the Radon transform and pure shift technique for studying chemical shifts perturbations.

Chemical shift plays an important role in molecular analysis. However, chemical shifts are influenced by temperature, solvent concentration, pressure, and so forth. Therefore, measuring chemical shift perturbations caused by these factors is helpful to molecular studies. A new form of 2-D spectroscopy (projection spectroscopy) has been introduced whose indirect dimension is derived by implementing the Radon transform on a series of conventional 1-D proton spectra and indicates such perturbations. However, signal overlap may exist in the conventional 1-D spectra and hence in the resulting projection spectra, hampering clear multiplet analysis and accurate extraction of perturbations. Here, the pure shift decoupling technique is employed to obtain clearer projection spectrum with higher spectral resolution. The combination of pure shift technique and the Radon transform is helpful to accurately extract chemical shift perturbations. It is believed that this application will open up a vast prospect for molecular analysis.

Grape Small Auxin Upregulated RNA (SAUR) 041 Is a Candidate Regulator of Berry Size in Grape.

Grape (Vitis vinifera) is an important horticultural crop that can be used to make juice and wine. However, the small size of the berry limits its yield. Cultivating larger berry varieties can be an effective way to solve this problem. As the largest family of auxin early response genes, SAUR (small auxin upregulated RNA) plays an important role in the growth and development of plants. Berry size is one of the important factors that determine grape quality. However, the SAUR gene family's function in berry size of grape has not been studied systematically. We identified 60 SAUR members in the grape genome and divided them into 12 subfamilies based on phylogenetic analysis. Subsequently, we conducted a comprehensive and systematic analysis on the SAUR gene family by analyzing distribution of key amino acid residues in the domain, structural features, conserved motifs, and protein interaction network, and combined with the heterologous expression in Arabidopsis and tomato. Finally, the member related to grape berry size in SAUR gene family were screened. This genome-wide study provides a systematic analysis of grape SAUR gene family, further understanding the potential functions of candidate genes, and provides a new idea for grape breeding.

AvNAC030, a NAC Domain Transcription Factor, Enhances Salt Stress Tolerance in Kiwifruit.

Kiwifruit (Actinidia chinensis Planch) is suitable for neutral acid soil. However, soil salinization is increasing in kiwifruit production areas, which has adverse effects on the growth and development of plants, leading to declining yields and quality. Therefore, analyzing the salt tolerance regulation mechanism can provide a theoretical basis for the industrial application and germplasm improvement of kiwifruit. We identified 120 NAC members and divided them into 13 subfamilies according to phylogenetic analysis. Subsequently, we conducted a comprehensive and systematic analysis based on the conserved motifs, key amino acid residues in the NAC domain, expression patterns, and protein interaction network predictions and screened the candidate gene AvNAC030. In order to study its function, we adopted the method of heterologous expression in Arabidopsis. Compared with the control, the overexpression plants had higher osmotic adjustment ability and improved antioxidant defense mechanism. These results suggest that AvNAC030 plays a positive role in the salt tolerance regulation mechanism in kiwifruit.

Fully Exploiting the Power of 2D NMR J-Resolved Spectroscopy.

Nuclear magnetic resonance (NMR) spectroscopy is a powerful analytical tool that enables one to study molecular properties and interactions. Homonuclear couplings provide valuable structural information but are often difficult to disentangle in crowded 1H NMR spectra where complex multiplets and signal overlap commonly exist. Multidimensional NMR experiments push the power of NMR to a new level by providing better signal dispersion. Among them, 2D J-resolved spectroscopy is widely used for multiplet analysis and the measurement of scalar coupling constants. Here, we present a new 2D J-resolved method, CASCADE, through which easier multiplet analysis and unambiguous measurement of specific coupling constants can be achieved at the same time, fully exploiting the power of 2D J-resolved spectroscopy. It is expected that this method may replace a conventional 2D J experiment in many cases, facilitating structural and configurational studies as well as chemical and biological analyses.

A Learning-Enhanced Two-Pair Spatiotemporal Reflectance Fusion Model for GF-2 and GF-1 WFV Satellite Data.

Since requirements of related applications for time series remotely-sensed images with high spatial resolution have been hard to be satisfied under current observation conditions of satellite sensors, it is key to reconstruct high-resolution images at specified dates. As an effective data reconstruction technique, spatiotemporal fusion can be used to generate time series land surface parameters with a clear geophysical significance. In this study, an improved fusion model based on the Sparse Representation-Based Spatiotemporal Reflectance Fusion Model (SPSTFM) is developed and assessed with reflectance data from Gaofen-2 Multi-Spectral (GF-2 MS) and Gaofen-1 Wide-Field-View (GF-1 WFV). By introducing a spatially enhanced training method to dictionary training and sparse coding processes, the developed fusion framework is expected to promote the description of high-resolution and low-resolution overcomplete dictionaries. Assessment indices including Average Absolute Deviation (AAD), Root-Mean-Square Error (RMSE), Peak Signal to Noise Ratio (PSNR), Correlation Coefficient (CC), spectral angle mapper (SAM), structure similarity (SSIM) and Erreur Relative Global Adimensionnelle de Synthèse (ERGAS) are then used to test employed fusion methods for a parallel comparison. The experimental results show that more accurate prediction of GF-2 MS reflectance than that from the SPSTFM can be obtained and furthermore comparable with popular two-pair based reflectance fusion models like the Spatial and Temporal Adaptive Fusion Model (STARFM) and the Enhanced-STARFM (ESTARFM).

Engineered M2 macrophage-derived extracellular vesicles with platelet membrane fusion for targeted therapy of atherosclerosis.

Atherosclerosis is featured as chronic low-grade inflammation in the arteries, which leads to the formation of plaques rich in lipids. M2 macrophage-derived extracellular vesicles (M2EV) have significant potential for anti-atherosclerotic therapy. However, their therapeutic effectiveness has been hindered by their limited targeting capability in vivo. The objective of this study was to create the P-M2EV (platelet membrane-modified M2EV) using the membrane fusion technique in order to imitate the interaction between platelets and macrophages. P-M2EV exhibited excellent physicochemical properties, and microRNA (miRNA)-sequencing revealed that the extrusion process had no detrimental effects on miRNAs carried by the nanocarriers. Remarkably, miR-99a-5p was identified as the miRNA with the highest expression level, which targeted the mRNA of Homeobox A1 (HOXA1) and effectively suppressed the formation of foam cells in vitro. In an atherosclerotic low-density lipoprotein receptor-deficient (Ldlr-/-) mouse model, the intravenous injection of P-M2EV showed enhanced targeting and greater infiltration into atherosclerotic plaques compared to regular extracellular vesicles. Crucially, P-M2EV successfully suppressed the progression of atherosclerosis without causing systemic toxicity. The findings demonstrated a biomimetic platelet-mimic system that holds great promise for the treatment of atherosclerosis in clinical settings.

Enhancing aortic valve drug delivery with PAR2-targeting magnetic nano-cargoes for calcification alleviation.

Calcific aortic valve disease is a prevalent cardiovascular disease with no available drugs capable of effectively preventing its progression. Hence, an efficient drug delivery system could serve as a valuable tool in drug screening and potentially enhance therapeutic efficacy. However, due to the rapid blood flow rate associated with aortic valve stenosis and the lack of specific markers, achieving targeted drug delivery for calcific aortic valve disease has proved to be challenging. Here we find that protease-activated-receptor 2 (PAR2) expression is up-regulated on the plasma membrane of osteogenically differentiated valvular interstitial cells. Accordingly, we develop a magnetic nanocarrier functionalized with PAR2-targeting hexapeptide for dual-active targeting drug delivery. We show that the nanocarriers effectively deliver XCT790-an anti-calcification drug-to the calcified aortic valve under extra magnetic field navigation. We demonstrate that the nano-cargoes consequently inhibit the osteogenic differentiation of valvular interstitial cells, and alleviate aortic valve calcification and stenosis in a high-fat diet-fed low-density lipoprotein receptor-deficient (Ldlr-/-) mouse model. This work combining PAR2- and magnetic-targeting presents an effective targeted drug delivery system for treating calcific aortic valve disease in a murine model, promising future clinical translation.

A novel mouse model of calcific aortic valve stenosis.

BACKGROUND: Calcific aortic valve stenosis (CAVS) is one of the most challenging heart diseases in clinical with rapidly increasing prevalence. However, study of the mechanism and treatment of CAVS is hampered by the lack of suitable, robust and efficient models that develop hemodynamically significant stenosis and typical calcium deposition. Here, we aim to establish a mouse model to mimic the development and features of CAVS. METHODS: The model was established via aortic valve wire injury (AVWI) combined with vitamin D subcutaneous injected in wild type C57/BL6 mice. Serial transthoracic echocardiography was applied to evaluate aortic jet peak velocity and mean gradient. Histopathological specimens were collected and examined in respect of valve thickening, calcium deposition, collagen accumulation, osteogenic differentiation and inflammation. RESULTS: Serial transthoracic echocardiography revealed that aortic jet peak velocity and mean gradient increased from 7 days post model establishment in a time dependent manner and tended to be stable at 28 days. Compared with the sham group, simple AVWI or the vitamin D group, the hybrid model group showed typical pathological features of CAVS, including hemodynamic alterations, increased aortic valve thickening, calcium deposition, collagen accumulation at 28 days. In addition, osteogenic differentiation, fibrosis and inflammation, which play critical roles in the development of CAVS, were observed in the hybrid model. CONCLUSIONS: We established a novel mouse model of CAVS that could be induced efficiently, robustly and economically, and without genetic intervention. It provides a fast track to explore the underlying mechanisms of CAVS and to identify more effective pharmacological targets.

Emerging roles of macrophages in heart failure and associated treatment approaches.

Heart failure is typically caused by different cardiovascular conditions and has a poor prognosis. Despite the advances in treatment in recent decades, heart failure has remained a major cause of morbidity and mortality worldwide. As revealed by in vivo and in vitro experiments, inflammation plays a crucial role in adverse cardiac remodeling, ultimately leading to heart failure. Macrophages are central to the innate immune system, and they are the most indispensable cell type for all cardiac injuries and remodeling stages. The immediate microenvironment regulates their polarization and secretion. In this review, we summarize the phenotypic heterogeneity and governing roles of macrophages in the infarcted, inflamed, and aging heart and assess their significance as potential therapeutic targets in heart failure. We also highlight the current missing links and major challenges in the field that remain to be addressed before macrophages can be exploited for therapeutic applications.

Programing Cell Assembly via Ink-Free, Label-Free Magneto-Archimedes Based Strategy.

Tissue engineering raised a high requirement to control cell distribution in defined materials and structures. In "ink"-based bioprintings, such as 3D printing and photolithography, cells were associated with inks for spatial orientation; the conditions suitable for one ink are hard to apply on other inks, which increases the obstacle in their universalization. The Magneto-Archimedes effect based (Mag-Arch) strategy can modulate cell locomotion directly without impelling inks. In a paramagnetic medium, cells were repelled from high magnetic strength zones due to their innate diamagnetism, which is independent of substrate properties. However, Mag-Arch has not been developed into a powerful bioprinting strategy as its precision, complexity, and throughput are limited by magnetic field distribution. By controlling the paramagnetic reagent concentration in the medium and the gaps between magnets, which decide the cell repelling scope of magnets, we created simultaneously more than a hundred micrometer scale identical assemblies into designed patterns (such as alphabets) with single/multiple cell types. Cell patterning models for cell migration and immune cell adhesion studies were conveniently created by Mag-Arch. As a proof of concept, we patterned a tumor/endothelial coculture model within a covered microfluidic channel to mimic epithelial-mesenchymal transition (EMT) under shear stress in a cancer pathological environment, which gave a potential solution to pattern multiple cell types in a confined space without any premodification. Overall, our Mag-Arch patterning presents an alternative strategy for the biofabrication and biohybrid assembly of cells with biomaterials featured in controlled distribution and organization, which can be broadly employed in tissue engineering, regenerative medicine, and cell biology research.