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COVID-19 is associated with 5.1% mortality. Although the virological, epidemiological, clinical, and management outcome features of COVID-19 patients have been defined rapidly, the inflammatory and immune profiles require definition as they influence pathogenesis and clinical expression of COVID-19. Here we show lymphopenia, selective loss of CD4+ T cells, CD8+ T cells and NK cells, excessive T-cell activation and high expression of T-cell inhibitory molecules are more prominent in severe cases than in those with mild disease. CD8+ T cells in patients with severe disease express high levels of cytotoxic molecules. Histochemical studies of lung tissue from one fatality show sub-anatomical distributions of SARS-CoV-2 RNA and massive infiltration of T cells and macrophages. Thus, aberrant activation and dysregulation of CD8+ T cells occur in patients with severe COVID-19 disease, an effect that might be for pathogenesis of SARS-CoV-2 infection and indicate that immune-based targets for therapeutic interventions constitute a promising treatment for severe COVID-19 patients. Immunophenotyping of patients with COVID-19 is ongoing, but much remains to be learned. Here the authors analyze 41 hospitalized patients with COVID-19 and show a higher degree of lymphopenia in various immune cell subsets as well as cytotoxicity and T cell inhibitory marker expression in severe cases compared with mild.

Proprotein convertase subtilisin/kexin type 9 (PCSK9) promotes degradation of low-density lipoprotein receptor (LDLR) and plays a central role in regulating plasma levels of LDL cholesterol levels, lipoprotein(a) and triglyceride-rich lipoproteins, increasing the risk of cardiovascular disease. Additionally, PCSK9 promotes degradation of major histocompatibility protein class I and reduces intratumoral infiltration of cytotoxic T cells. Inhibition of PCSK9 increases expression of LDLR, thereby reducing plasma levels of lipoproteins and the risk of cardiovascular disease. PCSK9 inhibition also increases cell surface levels of major histocompatibility protein class I in cancer cells and suppresses tumor growth. Therefore, PCSK9 plays a vital role in the pathogenesis of cardiovascular disease and cancer, the top two causes of morbidity and mortality worldwide. Monoclonal anti-PCSK9 antibody-based therapy is currently the only available treatment that can effectively reduce plasma LDL-C levels and suppress tumor growth. However, high expenses limit their widespread use. PCSK9 promotes lysosomal degradation of its substrates, but the detailed molecular mechanism by which PCSK9 promotes degradation of its substrates is not completely understood, impeding the development of more cost-effective alternative strategies to inhibit PCSK9. Here, we review our current understanding of PCSK9 and focus on the regulation of its expression and functions.

Plasma low-density lipoprotein (LDL) is primarily cleared by LDL receptor (LDLR). LDLR can be proteolytically cleaved to release its soluble ectodomain (sLDLR) into extracellular milieu. However, the proteinase responsible for LDLR cleavage is unknown. Here we report that membrane type 1-matrix metalloproteinase (MT1-MMP) co-immunoprecipitates and co-localizes with LDLR and promotes LDLR cleavage. Plasma sLDLR and cholesterol levels are reduced while hepatic LDLR is increased in mice lacking hepatic MT1-MMP. Opposite effects are observed when MT1-MMP is overexpressed. MT1-MMP overexpression significantly increases atherosclerotic lesions, while MT1-MMP knockdown significantly reduces cholesteryl ester accumulation in the aortas of apolipoprotein E (apoE) knockout mice. Furthermore, sLDLR is associated with apoB and apoE-containing lipoproteins in mouse and human plasma. Plasma levels of sLDLR are significantly increased in subjects with high plasma LDL cholesterol levels. Thus, we demonstrate that MT1-MMP promotes ectodomain shedding of hepatic LDLR, thereby regulating plasma cholesterol levels and the development of atherosclerosis. Elevated plasma LDL cholesterol levels increase the risk of atherosclerotic cardiovascular disease. Here, the authors show that inhibition of MT1-MMP reduces plasma LDL cholesterol levels and the risk of atherosclerosis, indicating the potential of MT1-MMP inhibition as a lipid-lowering therapy.

Artificial intelligence (AI) drives transformative changes in orthopedic surgery, steering it toward precision and personalization through intelligent applications in preoperative planning, intraoperative assistance, and postoperative rehabilitation/monitoring. Breakthroughs in deep learning, robotics, and multimodal data fusion have enabled AI to demonstrate significant advantages. Nonetheless, current applications face challenges such as limited real‐time decision autonomy, fragmented medical data silos, standardization gaps restricting model generalization, and ethical/regulatory frameworks lagging behind technological advancements. Therefore, a critical analysis of the current status of AI and the acceleration of its clinical translation is urgently required. This study systematically reviews the core advancements, challenges, and future directions of AI in orthopedic surgery from technical, clinical, and ethical perspectives. It elaborates on the “perceptual‐decisional‐executional” intelligent closed loop formed by algorithmic innovation and hardware upgrades, summarizes AI applications across surgical continuum, analyzes ethical and regulatory challenges, and explores emerging trajectories. This review integrates the end‐to‐end applications of AI in orthopedics, illustrating its evolution. It introduces an “algorithm‐hardware‐ethics trinity” framework for technical translation, providing methodological guidance for interdisciplinary collaboration. Additionally, it evaluates the combined efficacy of diverse algorithms and devices through practical cases and details of future research frontiers, aiming to inform researchers of current landscapes and guide subsequent investigations. AI drives transformative changes in orthopedic surgery, steering it toward precision and personalization through intelligent applications in preoperative planning, intraoperative assistance, and postoperative rehabilitation/monitoring. Breakthroughs in deep learning, robotics, and multimodal data fusion have enabled AI to demonstrate significant advantages. Nonetheless, current applications face challenges such as limited real‐time decision autonomy (reliance on static preoperative data), fragmented medical data silos, standardization gaps restricting model generalization, and ethical/regulatory frameworks lagging behind technological advancements. Therefore, a critical analysis of the current status of AI and the acceleration of its clinical translation is urgently required. This study systematically reviews the core advancements, challenges, and future directions of AI in orthopedic surgery from technical, clinical, and ethical perspectives. It elaborates on the “perceptual‐decisional‐executional” intelligent closed loop formed by algorithmic innovation and hardware upgrades, summarizes AI applications across the full surgical continuum, analyzes ethical and regulatory challenges, and explores emerging trajectories. This review integrates the end‐to‐end applications of AI in orthopedics, illustrating its evolution from assistive to semi‐autonomous systems. It introduces an “algorithm‐hardware‐ethics trinity” framework for technical translation, providing methodological guidance for interdisciplinary collaboration. Additionally, it evaluates the combined efficacy of diverse algorithms and devices through practical cases and details of future research frontiers, aiming to inform researchers of current landscapes and guide subsequent investigations.

Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of mortality and morbidity worldwide despite advancements in therapeutic options for the management of atherosclerosis (AS). Treatments that lower low‐density lipoprotein (LDL) cholesterol levels, such as statins or proprotein convertase subtilisin/kexin type 9 inhibitors, have effectively reduced ASCVD risk. However, residual CVD risk remains high, highlighting the need for additional effective therapies. Recently, colchicine has been approved for managing AS, introducing new avenues for targeting inflammation, a key process in AS. Various factors contribute to AS progression, such as endothelial dysfunction, leukocyte transmigration, vascular smooth muscle cell migration and phenotype‐switching, increased lipid retention, production of pro‐inflammatory cytokines and regulated cell death processes such as apoptosis. The annexin A (AnxA) family of proteins is well‐known for their ability to bind Ca2+ and phospholipids, and they play diverse roles in inflammation, cell proliferation, migration, differentiation and signalling. Several AnxA proteins have been implicated in essential processes involved in AS development, including endothelial dysfunction, leukocyte transmigration and apoptosis. In this mini‐review, we highlight the roles of AnxA1, AnxA2, AnxA5, AnxA6, AnxA7 and AnxA8 in AS development and progression and their therapeutic potential in AS management. Annexin A (AnxA) family members, including AnxA1, AnxA2, AnxA5, AnxA6, AnxA7 and AnxA8, play diverse roles in the development and progression of atherosclerosis and present promising therapeutic targets for its treatment.

Imidazole-based compounds are a series of heterocyclic compounds that exhibit a wide range of biological and pharmaceutical activities. However, those extant syntheses using conventional protocols can be time-costly, require harsh conditions, and result in low yields. As a novel and green technique, sonochemistry has emerged as a promising method for organic synthesis with several advantages over conventional methods, including enhancing reaction rates, improving yields, and reducing the use of hazardous solvents. Contemporarily, a growing body of ultrasound-assisted reactions have been applied in the preparation of imidazole derivatives, which demonstrated greater benefits and provided a new strategy. Herein, we introduce the brief history of sonochemistry and focus on the discussion of the multifarious approaches for the synthesis of imidazole-based compounds under ultrasonic irradiation and its advantages in comparison with conventional protocols, including typical name-reactions and various sorts of catalysts in those reactions.

Mitochondria are dynamic organelles with multiple functions. They participate in necrotic cell death and programmed apoptotic, and are crucial for cell metabolism and survival. Mitophagy serves as a cytoprotective mechanism to remove superfluous or dysfunctional mitochondria and maintain mitochondrial fine-tuning numbers to balance intracellular homeostasis. Growing evidences show that mitophagy, as an acute tissue stress response, plays an important role in maintaining the health of the mitochondrial network. Since the timely removal of abnormal mitochondria is essential for cell survival, cells have evolved a variety of mitophagy pathways to ensure that mitophagy can be activated in time under various environments. A better understanding of the mechanism of mitophagy in various diseases is crucial for the treatment of diseases and therapeutic target design. In this review, we summarize the molecular mechanisms of mitophagy-mediated mitochondrial elimination, how mitophagy maintains mitochondrial homeostasis at the system levels and organ, and what alterations in mitophagy are related to the development of diseases, including neurological, cardiovascular, pulmonary, hepatic, renal disease, etc., in recent advances. Finally, we summarize the potential clinical applications and outline the conditions for mitophagy regulators to enter clinical trials. Research advances in signaling transduction of mitophagy will have an important role in developing new therapeutic strategies for precision medicine.

The nucleocapsid protein (NP) of SARS-CoV-2, an RNA-binding protein, is capable of undergoing liquid-liquid phase separation (LLPS) during viral infection, which plays a crucial role in virus assembly, replication, and immune regulation. In this study, we developed a homogeneous time-resolved fluorescence (HTRF) method for identifying inhibitors of the SARS-CoV-2 NP-RNA interaction. Using this HTRF-based approach, we identified two natural products, sennoside A and sennoside B, as effective blockers of this interaction. Bio-layer interferometry assays confirmed that both sennosides directly bind to the NP, with binding sites located within the C-terminal domain. Additionally, fluorescence recovery after photobleaching (FRAP) experiments revealed that sennoside B significantly inhibited RNA-induced LLPS of the NP, while sennoside A displayed comparatively weaker activity. Thus, the developed HTRF-based assay is a valuable tool for identifying novel compounds that disrupt the RNA-binding activity and LLPS of the SARS-CoV-2 NP. Our findings may facilitate the development of antiviral drugs targeting SARS-CoV-2 NP.

Background The gefitinib resistance mechanism in non-small cell lung cancer (NSCLC) remains unclear, albeit exosomal circular RNA (circRNA) is known to possibly play a vital role in it. Methods We employed high-throughput sequencing techniques to detect the expressions of exosomal circRNA both in gefitinib-resistant and gefitinib-sensitive cells in this study. The circKIF20B expression was determined in serum exosomes and tissues of patients by qRT-PCR. The structure, stability, and intracellular localization of circKIF20B were verified by Sanger sequencing, Ribonuclease R (RNase R)/actinomycin D (ACTD) treatments, and Fluorescence in situ hybridization (FISH). The functions of circKIF20B were investigated by 5-Ethynyl-20-deoxyuridine (EdU), flow cytometry, Cell Counting Kit-8 (CCK-8), oxygen consumption rate (OCR), and xenograft model. Co-culture experiments were performed to explore the potential ability of exosomal circKIF20B in treating gefitinib resistance. The downstream targets of circKIF20B were determined by luciferase assay, RNA pulldown, and RNA immunoprecipitation (RIP). Results We found that circKIF20B was poorly expressed in the serum exosomes of gefitinib-resistant patients (n = 24) and the tumor tissues of patients with NSCLC (n = 85). CircKIF20B was negatively correlated with tumor size and tumor stage. Decreasing circKIF20B was found to promote gefitinib resistance by accelerating the cell cycle, inhibiting apoptosis, and enhancing mitochondrial oxidative phosphorylation (OXPHOS), whereas increasing circKIF20B was found to restore gefitinib sensitivity. Mechanistically, circKIF20B is bound to miR-615-3p for regulating the MEF2A and then altering the cell cycle, apoptosis, and mitochondrial OXPHOS. Overexpressing circKIF20B parental cells can restore sensitivity to gefitinib in the recipient cells by upregulating the exosomal circKIF20B expression. Conclusions This study revealed a novel mechanism of circKIF20B/miR-615-3p/MEF2A signaling axis involving progression of gefitinib resistance in NSCLC. Exosomal circKIF20B is expected to be an easily accessible and alternative liquid biopsy candidate and potential therapeutic target in gefitinib-resistant NSCLC. Graphical Abstract The schematic diagram of mechanism in this study. Exosomal circKIF20B inhibits gefitinib resistance and cell proliferation by arresting the cell cycle, promoting apoptosis, and reducing OXPHOS via circKIF20B/miR-615-3p/MEF2A axis in NSCLC.

IntroductionThe diagnosis and treatment of osteoporosis, a frequent age-related metabolic bone disorder, remain incomprehensive and challenging. The potential regulatory role of lncRNA XIST and sphingosine kinase 1 (SPHK1) pathway need experimental investigations.Materials and methodsRAW264.7 cells and BMMs were obtained for in vitro studies and 30 ng/mL RANKL was implemented for induction of osteoclast differentiation. The suppressing of lncRNA XIST, SPHK1 and fused in sarcoma (FUS) was achieved using small hairpin RNA, while overexpression of XIST and FUS was constructed by pcDNA3.1 vector system. Tartrate-resistant acid phosphatase (TRAP) staining was used for observation of formation of osteoclasts. RNA-pulldown analysis and RNA binding protein immunoprecipitation (RIP) was implemented for measuring mRNA and protein interactions. RT-qPCR was conducted to determining mRNA expression, whereas ELISA and Western blotting assay was performed for monitoring protein expression.ResultsRANKL induced osteoclast differentiation and upregulated expression of osteoclastogenesis-related genes that included NFATc1, CTSK, TRAP and SPHK1 and the level of lncRNA XIST in both RAW264.7 cells and BMMs. However, knockdown of lncRNA XIST or suppressing SPHK1 significantly reserved the effects of RANKL. LncRNA XIST was further demonstrated to be interacted with FUS and increased the stability of SPHK1, indicating its ability in promoting osteoclast differentiation through SPHK1/S1P/ERK signaling pathway.ConclusionLncRNA XIST promoted osteoclast differentiation via interacting with FUS and upregulating SPHK1/S1P/ERK pathway.