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Myocardial ischemia-reperfusion injury (MIRI) significantly worsens the outcomes of patients with cardiovascular diseases. Dexmedetomidine (Dex) is recognized for its cardioprotective properties, but the related mechanisms, especially regarding metabolic reprogramming, have not been fully clarified. A total of 60 patients with heart valve disease are randomly assigned to Dex or control group. Blood samples are collected to analyze cardiac injury biomarkers and metabolomics. In vivo and vitro rat models of MIRI are utilized to assess the effects of Dex on cardiac function, lactate production, and mitochondrial function. It is found that postoperative CK-MB and cTNT levels are significantly lower in the Dex group. Metabolomics reveals that Dex regulates metabolic reprogramming and reduces lactate level. In Dex-treated rats, the myocardial infarction area is reduced, and myocardial contractility is improved. Dex inhibits glycolysis, reduces lactate, and improves mitochondrial function following MIRI. Lactylation proteomics identifies that Dex reduces the lactylation of Malate Dehydrogenase 2（MDH2), thus alleviating myocardial injury. Further studies reveal that MDH2 lactylation induces ferroptosis, leading to MIRI by impairing mitochondrial function. Mechanistic analyses reveal that Dex upregulates Nuclear Receptor Subfamily 3 Group C Member 1（NR3C1) phosphorylation, downregulates Pyruvate Dehydrogenase Kinase 4 (PDK4), and reduces lactate production and MDH2 lactylation. These findings provide new therapeutic targets and mechanisms for the treatment for MIRI., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

Background: The development of biomaterials capable of accelerating bone wound repair is a critical focus in bone tissue engineering. This study aims to evaluate the osteointegration and bone regeneration potential of a novel multilayer gelatin-supported Bone Morphogenetic Protein 9 (BMP-9) coated nano-calcium-deficient hydroxyapatite/poly-amino acid (n-CDHA/PAA) composite biomaterials, focusing on the material-bone interface, and putting forward a new direction for the research on the interface between the coating material and bone., Methods: The BMP-9 recombinant adenovirus (Adenovirus (Ad)-BMP-9/Bone Marrow Mesenchymal Stem Cells (BMSc)) was produced by transfecting BMSc and supported using gelatin (Ad-BMP-9/BMSc/Gelatin (GT). Multilayer Ad-BMP-9/BMSc/GT coated nano-calcium deficient hydroxyapatite/polyamino acid (n-CDHA/PAA) composite biomaterials were then prepared and co-cultured with MG63 cells for 10 days, with biocompatibility assessed through microscopy, Cell Counting Kit-8 (CCK-8), and alkaline phosphatase (ALP) assays. Subsequently, multilayer Ad-BMP-9/BMSc/GT coated n-CDHA/PAA composite biomaterial screws were fabricated, and the adhesion of the coating to the substrate was observed using scanning electron microscopy (SEM). In vivo studies were conducted using a New Zealand White rabbit intercondylar femoral fracture model. The experimental group was fixed with screws featuring multilayer Ad-BMP-9/BMSc/GT coatings, while the control groups used medical metal screws and n-CDHA/PAA composite biomaterial screws. Fracture healing was monitored at 1, 4, 12, and 24 weeks, respectively, using X-ray observation, Micro-CT imaging, and SEM. Integration at the material-bone interface and the condition of neo-tissue were assessed through these imaging techniques., Results: The Ad-BMP-9/GT coating significantly enhanced MG63 cell adhesion, proliferation, and differentiation, while increasing BMP-9 expression in vitro . In vivo studies using a rabbit femoral fracture model confirmed the biocompatibility and osteointegration potential of the multilayer Ad-BMP-9/BMSc/GT coated n-CDHA/PAA composite biomaterial screws. Compared to control groups (medical metal screws and n-CDHA/PAA composite biomaterial screws), this material demonstrated faster fracture healing, stronger osteointegration, and facilitated new bone tissue formation with increased calcium deposition at the material-bone interface., Conclusion: The multilayer GT-supported BMP-9 coated n-CDHA/PAA composite biomaterials have demonstrated favorable osteogenic cell interface performance, both in vitro and in vivo . This study provides a foundation for developing innovative bone repair materials, holding promise for significant advancements in clinical applications., (© 2024 The Author(s). Published by IMR Press.)

Reactive oxidative stress (ROS) related apoptosis in chondrocytes and extracellular matrix (ECM) degradation play crucial roles in the process of osteoarthritis. Prussian blue nanoparticles are known to scavenge ROS in cellular. Low-intensity pulsed ultrasound has been used as a non-invasive modality for the is widely used in clinical rehabilitation management of OA. In this study, we aim to investigate the effects of PBNPs/LIPUS combined treatment on knee osteoarthritis (KOA) and to determine whether phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling pathway mediates this process. Use LPS to process primary cells of knee joint cartilage to establish a cartilage knee arthritis model. After treated with LIPUS and PBNPs, cell viability was rated by CCK-8 and ROS levels were assessed by DCFH-DA. Articular pathological changes were observed by naked eyes, H&E, and Safranin O staining, then monitored by cartilage lesion grades and Mankin's score. Cellular ROS, apoptosis rate, and TUNEL staining of chondrocytes were fairly decreased in the PBNPs group and the LIPUS group but drastically down-regulated in the PBNPs/LIPUS combination treatment group when compared with the LPS group. Western blot results showed that the cleaved caspase-3, Bax, IL-1β, MMP3 and MMP13 in the PBNPs and LIPUS groups slightly decreased, and Bcl2 increased slightly, while in the combination treatment group, the former was significantly decreased, and Bcl2 was Significantly increased. The PBNPs/LIPUS combination treatment reduced cellular ROS, apoptosis, and matrix metalloproteinases (MMPs), as a consequence, alleviated articular cartilage damage in KOA. Moreover, the PBNPs/LIPUS combination treatment suppressed the JNK/c-Jun signal pathway., Competing Interests: None., (AJTR Copyright © 2021.)