Targeted delivery of MerTK protein via cell membrane engineered nanoparticle enhances efferocytosis and attenuates atherosclerosis in diabetic ApoE-/- Mice.

BACKGROUND: Clearance of apoptotic cells by efferocytosis is crucial for prevention of atherosclerosis progress, and impaired efferocytosis contributes to the aggravated atherosclerosis. RESULTS: In this study, we found that diabetic ApoE-/- mice showed aggravated atherosclerosis as hyperglycemia damaged the efferocytosis capacity at least partially due to decreased expression of Mer tyrosine kinase (MerTK) on macrophages. To locally restore MerTK in the macrophages in the plaque, hybrid membrane nanovesicles (HMNVs) were thus developed. Briefly, cell membrane from MerTK overexpressing RAW264.7 cell and transferrin receptor (TfR) overexpressing HEK293T cell were mixed with DOPE polymers to produce nanovesicles designated as HMNVs. HMNVs could fuse with the recipient cell membrane and thus increased MerTK in diabetic macrophages, which in turn restored the efferocytosis capacity. Upon intravenous administration into diabetic ApoE-/- mice, superparamagnetic iron oxide nanoparticles (SMN) decorated HMNVs accumulated at the aorta site significantly under magnetic navigation, where the recipient macrophages cleared the apoptotic cells efficiently and thus decreased the inflammation. CONCLUSIONS:  Our study indicates that MerTK decrease in macrophages contributes to the aggravated atherosclerosis in diabetic ApoE-/- mice and regional restoration of MerTK in macrophages of the plaque via HMNVs could be a promising therapeutic approach.

Drought Stress Induced Different Response Mechanisms in Three Dendrobium Species under Different Photosynthetic Pathways.

Many Dendrobium species, which hold a high status and value in traditional Chinese medicine, grow on barks and rocks in the wild, often encountering harsh environments and facing droughts. However, the molecular mechanisms underlying the shift in the photosynthetic pathway induced by drought remain unclear. To address this issue, three Dendrobium species with different photosynthetic pathways were selected for sequencing and transcriptome data analysis after drought treatment. The findings included 134.43 GB of sequencing data, with numerous Differentially Expressed Genes (DEGs) exhibiting different response mechanisms under drought stress. Gene Ontology (GO)-KEGG-based enrichment analysis of DEGs revealed that metabolic pathways contributed to drought tolerance and alterations in photosynthetic pathways. Phosphoenolpyruvate Carboxylase (PEPC) was subjected to phylogenetic tree construction, sequence alignment, and domain analysis. Under drought stress, variations were observed in the PEPC gene structure and expression among different Dendrobium species; the upregulation of Dc_gene2609 expression may be caused by dof-miR-384, which resulted in the shift from C3 photosynthesis to CAM, thereby improving drought tolerance in Dendrobium. This study revealed the expression patterns and roles of PEPC genes in enhancing plant drought tolerance and will provide an important basis for in-depth research on Dendrobium's adaptation mechanisms in arid environments.

Chemerin regulates formation and function of brown adipose tissue: Ablation results in increased insulin resistance with high fat challenge and aging.

Apart from its role in inflammation and immunity, chemerin is also involved in white adipocyte biology. To study the role of chemerin in adipocyte metabolism, we examined the function of chemerin in brown adipose tissue. Brown and white adipocyte precursors were differentiated into adipocytes in the presence of Chemerin siRNA. Chemerin-deficient (Chem-/- ) mice were compared to wild-type mice when fed a high-fat diet. Chemerin is expressed during brown adipocyte differentiation and knock down of chemerin mRNA results in decreased brown adipocyte differentiation with reduced fatty acid uptake in brown adipocytes. Chem-/- mice are leaner than wild-type mice but gain more weight when challenged with high-fat diet feeding, resulting in a larger increase in fat deposition. Chem-/- mice develop insulin resistance when on a high-fat diet or due to age. Brown adipose depots in Chem-/- mice weigh more than in wild-type mice, but with decreased mitochondrial content and function. Compared to wild-type mice, male Chem-/- mice have decreased oxygen consumption, CO2 production, energy expenditure, and a lower respiratory exchange ratio. Additionally, body temperature of Chem-/- mice is lower than that of wild-type mice. These results revealed that chemerin is expressed during brown adipocyte differentiation and has a pivotal role in energy metabolism through brown adipose tissue thermogenesis.

Comparison between chronic spontaneous urticaria and chronic induced urticaria on the efficacy of omalizumab treatment: A systematic review and meta-analysis.

This meta-analysis aimed to assess the efficacy of omalizumab in the treatment of refractory-to-antihistamines chronic induced urticaria (CIndU) in comparison with that of refractory-to-antihistamines chronic spontaneous urticaria (CSU). We retrieved interventional studies and observational studies on omalizumab efficacy to CIndU patients and efficacy comparison between CSU and CIndU both refractory to H1-antihistamines in electronic databases (accessed till May 2022). The odd ratio (OR) and 95% confidence interval (CI) was calculated with a random-effect model in this meta-analysis. The majority of patients with different CIndU subtypes gained complete or partial response and good safety after omalizumab treatment. A total of five studies with 355 CSU patients and 103 CIndU patients were included for the meta-analysis. There was no significant difference in the efficacy of omalizumab in the treatment of CSU and CIndU (OR -0.83, 95% CI [0.84, 2.21], P > 0.05). Based on the validity of omalizumab in the treatment of various CIndU subtypes and non-differential efficacy between CSU and CIndU, it is reasonable to list omalizumab as a third-line treatment of refractory CIndU.

Maleimide structure: a promising scaffold for the development of antimicrobial agents.

Natural compounds bearing maleimide rings are a series of secondary metabolites derived from fungi/marine microorganisms, which are characterized by a general structure -CO-N(R)-CO-, and the R group is normally substituted with alkyl or aryl groups. Maleimide compounds show various biological activities such as antibacterial, antifungal, and anticancer activity. In this review, the broad-spectrum antimicrobial activities of 15 maleimide compounds from natural sources and 32 artificially synthesized maleimides were summarized, especially against Candida albicans, Sclerotinia sclerotiorum, and Staphylococcus aureus. It highlights that maleimide scaffold has tremendous potential to be utilized in the development of novel antimicrobial agents.

Protection-Free Strategy for the Synthesis of Boro-Depsipeptides in Aqueous Media under Microwave-Assisted Conditions.

In this report, 19 boron-containing depsipeptides were synthesized via microwave-assisted Passerini three-component reaction (P-3CR) in an aqueous environment. The linker-free DAHMI fluorescent tagging approach was used on selected boron-containing compounds to study the relationship between their structures and their level of cellular uptake of HEK293 cells. The biological data retrieved from the DAHMI experiments indicated that while the structures of tested compounds may be highly similar, their bio-distribution profile could be vastly distinctive. The reported optimized one-pot synthetic strategy along the linker-free in vitro testing protocol could provide an efficient platform to accelerate the development of boron-containing drugs.

Exosomes Secreted by Young Mesenchymal Stem Cells Promote New Bone Formation During Distraction Osteogenesis in Older Rats.

Distraction osteogenesis (DO) is a clinically effective procedure to regenerate large bone defects. However, the treatment duration is undesirably lengthy, especially in elderly patients. Exosomes derived from mesenchymal stem cells (MSC-Exos) could exert the beneficial effects while avoiding the possible complications of stem cell transplantation. This study aimed to evaluate the effects of MSC-Exos on bone regeneration during DO in older rats. Exosomes were isolated from the supernatants of young bone marrow mesenchymal stem cells (BMSCs) through ultra-centrifugation, and characterized using transmission electron microscopy, western blot, and tunable resistive pulse sensing analysis. The effects of MSC-Exos on the proliferation and differentiation of older BMSCs were evaluated using CCK-8 assay, ALP and ARS staining, and qRT-PCR. Unilateral tibial DO model was established on older Sprague-Dawley rats and MSC-Exos or phosphate buffer saline was locally injected into the distraction gaps after distraction weekly. Bone regeneration were evaluated using X-ray, Micro-CT, mechanical test, and histological staining. The MSC-Exos were round or cup-shaped vesicles ranging from 60 to 130 nm in diameter and expressed markers including CD9, CD63, and TSG101. The in vitro results indicated that MSC-Exos could enhance the proliferation and osteogenic differentiation of older BMSCs. Bone regeneration was markedly accelerated in rats treated with MSC-Exos according to the results of X-ray, micro-CT, and histological analysis. The distracted tibias from the MSC-Exos group also demonstrated better mechanical properties. These results suggest that MSC-Exos promote DO-mediated bone regeneration in older rats through enhancing the proliferation and osteogenic capacity of BMSCs.

Artificial light at night alter the impact of arsenic on microbial decomposers and leaf litter decomposition in streams.

Artificial light at night (ALAN, also known as light pollution) has been proved to be a contributor to environmental change and a biodiversity threat worldwide, yet little is known about its potential interaction with different metal pollutants, such as arsenic (As), one of the largest threats to aquatic ecosystems. To narrow this gap, an indoor microcosm study was performed using an ALAN simulation device to examine whether ALAN exposure altered the impact of arsenic on plant litter decomposition and its associated fungi. Results revealed that microbial decomposers involved in the conversion of As(III) to As(V), and ALAN exposure enhanced this effect; ALAN or arsenic only exposure altered fungal community composition and the correlations between fungi species, as well as stimulated or inhibited litter decomposition, respectively. The negative effects of arsenic on the decomposition of Pterocarya stenoptera leaf litter was alleviated by ALAN resulting in the enhanced photodegradation of leaf litter lignin and microbiological oxidation of As(III) to As(V), the increased microbial biomass and CBH activity, as well as the enhanced correlations between CBH and litter decomposition rate. Overall, results expand our understanding of ALAN on environment and highlight the contribution of ALAN to the toxicity of arsenic in aquatic ecosystems.

Ferulic acid improves self-renewal and differentiation of human tendon-derived stem cells by upregulating early growth response 1 through hypoxia.

We aimed to investigate the potential beneficial effect of ferulic acid (FA) on stemness of human tendon-derived stem cells (hTSCs) in vitro and to elucidate the underlying molecular mechanism. The self-renewal ability of hTSCs was evaluated by colony formation and cell proliferation was determined by CCK-8 kit. Adipogenesis, osteogenesis, and chondrogenesis were determined by Oil Red O, Alizarin Red, and Alcian Blue stainings, respectively. Relative mRNA levels of PPARγ, Col2A1, Acan, Runx2, HIF1α, and EGR1 were measured with real-time PCR. Protein levels of HIF1α and EGR1 were detected by western blot. Direct binding of HIF1α with EGR1 promoter was analyzed by ChIP assay. Hypoxia-induced expression of EGR1 was interrogated by luciferase reporter assay. We demonstrated that FA treatment improved both self-renewal ability and multi-differentiation potential of hTSCs. FA induced hypoxia which in turn upregulated EGR1 expression via direct association with its hypoxia response element consensus sequence. Furthermore, we showed that both HIF1α and EGR1 were required for the enhancing effects of FA on hTSC self-renewal and differentiation. We hereby characterize the beneficial effect of FA on the stemness of hTSCs and highlight the critical role of HIF1α-EGR1 axis in this process.

Von Hippel-Lindau (VHL) protein antagonist, VH298, promotes functional activities of tendon-derived stem cells and accelerates healing of entheses in rats by inhibiting ubiquitination of hydroxy-HIF-1α.

Enthesis is the region where a tendon attaches to a bone. It is a relatively vulnerable position, and in most cases surgical treatment is required upon rupture. The reconstructed enthesis is usually weaker compared to the original, and is prone to rupture again. Hypoxia-inducible factor-1 α (HIF-1α) is known to be involved in extensive activities in cells. It is inhibited under normoxic conditions, and undergoes two essential processes, hydroxylation and ubiquitination, the latter of which has been largely unexplored. Herein, we measured the levels of HIF-1α and hydroxy-HIF-1α in VH298-treated rat tendon-derived stem cells (TDSCs) by immunoblotting. We also detected the proliferation of TDSCs using CCK-8 assay and the mRNA levels of related genes by quantitative RT-PCR. The TDSCs were observed to be induced and the chondrogenic differentiation related genes were found to be enhanced. We also simulated in-vitro wounding in a scratch test and reconstructed the enthesis in a rat model of Achilles tendon by classical surgery followed by administration of phosphate buffer saline (PBS) injection or VH298 injection. We observed that HIF-1α and hydroxy-HIF-1α levels were increased in VH298-treated TDSCs in a dose- and time-dependent manner. Thirty micromolar VH298 could significantly increase cell proliferation, migration, and expression of collagen-1α, collagen-3α, decorin, tenomodulin, tenascin C genes, and chondrogenic differentiation-related genes, collagen-2α, SRY-box9, aggrecan. VH298-treated enthesis could tolerate more load-to-failure, had a better healing pattern, and activation of HIF signaling pathway. VH298 can thus enhance the functional activities of TDSCs, enhance their chondrogenic differentiation potential, and accelerate enthesis healing by inhibiting the ubiquitination of hydroxy-HIF-1α.

Toward Ultrasound Molecular Imaging of Endothelial Dysfunction in Diabetes: Targets, Strategies, and Challenges.

Diabetes vasculopathy is a significant complication of diabetes mellitus (DM), and early identification and timely intervention can effectively slow the progression. Accumulating studies have shown that diabetes causes vascular complications directly or indirectly through a variety of mechanisms. Direct imaging of the endothelial molecular changes not only identifies the early stage of diabetes vasculopathy but also sheds light on the precise treatment. Targeted ultrasound contrast agent (UCA)-based ultrasound molecular imaging (UMI) can noninvasively detect the expression status of molecular biomarkers overexpressed in the vasculature, thereby being a potential strategy for the diagnosis and treatment response evaluation of DM. Amounts of efforts have been focused on identification of the molecular targets expressed in the vasculature, manufacturing strategies of the targeted UCA, and the clinical translation for the diagnosis and evaluation of therapeutic efficacy in both micro- and macrovasculopathy in DM. This review summarizes the latest research progress on endothelium-targeted UCA and discusses their promising future and challenges in diabetes vasculopathy theranostics.

Correlation between COVID-19 infection and fetal situs inversus.

BACKGROUND: Situs inversus is a rare congenital condition, defined by the mirror-image transposition of the abdominothoracic organs. It is linked to an increased risk of different disorders, for example, congenital heart defects and primary ciliary dyskinesia. Recently, some reports have been on the increased incidence of situs inversus after the COVID-19 pandemic. OBJECTIVES: To investigate the association between maternal COVID-19 infection and fetal situs inversus occurrence risk. METHODS: All pregnant women who underwent fetal ultrasound examinations at Jinan Maternal and Child Health Hospital from January to May of 2022 and 2023 were recruited. A chi-square test was conducted to assess the association of maternal COVID-19 infection with the incidence rate of fetal situs inversus. RESULTS: A total of 8381 patients, including 25 with situs inversus fetuses were recruited. A total of 3956 patients had COVID-19, while 4400 did not. Among 25 mothers with situs inversus fetuses, 22 had COVID-19 and 3 without recent infection. Our analysis showed a strong link between COVID-19 and a higher risk of fetus situs inversus (P < .001, odds ratio 8.196). CONCLUSION: Maternal COVID-19 infection in the early stages of the pregnancy is associated with an increased risk of fetal situs inversion occurrence. Therefore, further research in this field seems necessary.

Supplementation of Clostridium butyricum Alleviates Vascular Inflammation in Diabetic Mice.

BACKGRUOUND: Gut microbiota is closely related to the occurrence and development of diabetes and affects the prognosis of diabetic complications, and the underlying mechanisms are only partially understood. We aimed to explore the possible link between the gut microbiota and vascular inflammation of diabetic mice. METHODS: The db/db diabetic and wild-type (WT) mice were used in this study. We profiled gut microbiota and examined the and vascular function in both db/db group and WT group. Gut microbiota was analyzed by 16s rRNA sequencing. Vascular function was examined by ultrasonographic hemodynamics and histological staining. Clostridium butyricum (CB) was orally administered to diabetic mice by intragastric gavage every 2 days for 2 consecutive months. Reactive oxygen species (ROS) and expression of nuclear factor erythroid-derived 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) were detected by fluorescence microscopy. The mRNA expression of inflammatory cytokines was tested by quantitative polymerase chain reaction. RESULTS: Compared with WT mice, CB abundance was significantly decreased in the gut of db/db mice, together with compromised vascular function and activated inflammation in the arterial tissue. Meanwhile, ROS in the vascular tissue of db/db mice was also significantly increased. Oral administration of CB restored the protective microbiota, and protected the vascular function in the db/db mice via activating the Nrf2/HO-1 pathway. CONCLUSION: This study identified the potential link between decreased CB abundance in gut microbiota and vascular inflammation in diabetes. Therapeutic delivery of CB by gut transplantation alleviates the vascular lesions of diabetes mellitus by activating the Nrf2/HO-1 pathway.

Increased risk of fetal left-right asymmetry disorders associated with maternal SARS-CoV-2 infection during the first trimester.

Our center has observed a substantial increase in the detection rate of fetal left-right(LR) asymmetry disorders between March and May 2023. This finding has raised concerns because these pregnant women experienced the peak outbreak of SARS-CoV-2 in China during their first trimester. To explore the relationship between maternal SARS-CoV-2 infection and fetal LR asymmetry disorders. A retrospective collection of clinical and ultrasound data diagnosed as fetal LR asymmetry disorders was conducted from January 2018 to December 2023. The case-control study involved fetuses with LR asymmetry disorders and normal fetuses in a 1:1 ratio. We evaluated and compared the clinical and fetal ultrasound findings in pregnant women with SARS-CoV-2 infection and pregnant women without infection. The Student t-test was utilized to compare continuous variables, while the chi-squared test was employed for univariable analyses. The incidence rate of LR asymmetry disorders from 2018 to 2023 was as follows: 0.17‰, 0.63‰, 0.61‰, 0.57‰, 0.59‰, and 3.24‰, respectively. A total of 30 fetuses with LR asymmetry disorders and 30 normal fetuses were included. This case-control study found that SARS-CoV-2 infection (96.67% vs 3.33%, P = .026) and infection during the first trimester (96.55% vs 3.45%, P = .008) were identified as risk factors. The odds ratio values were 10.545 (95% CI 1.227, 90.662) and 13.067 (95% CI 1.467, 116.419) respectively. In cases of SARS-CoV-2 infection in the first trimester, the majority of infections (88.1%, 37/42) occurred between 5 and 6 weeks of gestation. We found that 43.7% (66/151) of fetuses with LR asymmetry disorder had associated malformations, 90.9% (60/66) exhibited cardiac malformations. SARS-CoV-2 infection during the first trimester significantly increases the risk of fetal LR asymmetry disorders, particularly when the infection occurs between 5 and 6 gestation weeks. The most common associated malformation is heart malformation.

Small molecule deoxynyboquinone triggers alkylation and ubiquitination of Keap1 at Cys489 on Kelch domain for Nrf2 activation and inflammatory therapy.

Activation of nuclear factor erythroid 2-related factor 2 (Nrf2) by Kelch-like ECH-associated protein 1 (Keap1) alkylation plays a central role in anti-inflammatory therapy. However, activators of Nrf2 through alkylation of Keap1-Kelch domain have not been identified. Deoxynyboquinone (DNQ) is a natural small molecule discovered from marine actinomycetes. The current study was designed to investigate the anti-inflammatory effects and molecular mechanisms of DNQ via alkylation of Keap1. DNQ exhibited significant anti-inflammatory properties both in vitro and in vivo. The pharmacophore responsible for the anti-inflammatory properties of DNQ was determined to be the α, ß-unsaturated amides moieties by a chemical reaction between DNQ and N-acetylcysteine. DNQ exerted anti-inflammatory effects through activation of Nrf2/ARE pathway. Keap1 was demonstrated to be the direct target of DNQ and bound with DNQ through conjugate addition reaction involving alkylation. The specific alkylation site of DNQ on Keap1 for Nrf2 activation was elucidated with a synthesized probe in conjunction with liquid chromatography-tandem mass spectrometry. DNQ triggered the ubiquitination and subsequent degradation of Keap1 by alkylation of the cysteine residue 489 (Cys489) on Keap1-Kelch domain, ultimately enabling the activation of Nrf2. Our findings revealed that DNQ exhibited potent anti-inflammatory capacity through α, ß-unsaturated amides moieties active group which specifically activated Nrf2 signal pathway via alkylation/ubiquitination of Keap1-Kelch domain, suggesting the potential values of targeting Cys489 on Keap1-Kelch domain by DNQ-like small molecules in inflammatory therapies.

IRCM-Caps: An X-ray image detection method for COVID-19.

OBJECTIVE: COVID-19 is ravaging the world, but traditional reverse transcription-polymerase reaction (RT-PCR) tests are time-consuming and have a high false-negative rate and lack of medical equipment. Therefore, lung imaging screening methods are proposed to diagnose COVID-19 due to its fast test speed. Currently, the commonly used convolutional neural network (CNN) model requires a large number of datasets, and the accuracy of the basic capsule network for multiple classification is limital. For this reason, this paper proposes a novel model based on CNN and CapsNet. METHODS: The proposed model integrates CNN and CapsNet. And attention mechanism module and multi-branch lightweight module are applied to enhance performance. Use the contrast adaptive histogram equalization (CLAHE) algorithm to preprocess the image to enhance image contrast. The preprocessed images are input into the network for training, and ReLU was used as the activation function to adjust the parameters to achieve the optimal. RESULT: The test dataset includes 1200 X-ray images (400 COVID-19, 400 viral pneumonia, and 400 normal), and we replace CNN of VGG16, InceptionV3, Xception, Inception-Resnet-v2, ResNet50, DenseNet121, and MoblieNetV2 and integrate with CapsNet. Compared with CapsNet, this network improves 6.96%, 7.83%, 9.37%, 10.47%, and 10.38% in accuracy, area under the curve (AUC), recall, and F1 scores, respectively. In the binary classification experiment, compared with CapsNet, the accuracy, AUC, accuracy, recall rate, and F1 score were increased by 5.33%, 5.34%, 2.88%, 8.00%, and 5.56%, respectively. CONCLUSION: The proposed embedded the advantages of traditional convolutional neural network and capsule network and has a good classification effect on small COVID-19 X-ray image dataset.

The position of the median nerve in relation to the palmaris longus tendon at the wrist: a study of 784 MR images.

Iatrogenic injury of the median nerve has been reported after endoscopic carpal tunnel release and corticoid injection. In 784 MR images of the wrist, the position of the median nerve in relation to the palmaris longus tendon was analysed. The ulnar edge of the median nerve was found medial to the palmaris longus tendon in 14% and 36% of patients at the proximal wrist crease and entrance of the carpal tunnel, respectively, compared with 23% and 40% of patients with carpal tunnel syndrome (88 patients). The position of the median nerve in relation to the palmaris longus tendon varies widely. It is suggested that the palmaris longus tendon may not be considered a safe landmark to locate the position of the median nerve and care should be taken when introducing an endoscopic instrument or during steroid injection for carpal tunnel syndrome.Level of evidence: IV.

Design, synthesis, and antifungal activity of novel dithiin tetracarboximide derivatives as potential succinate dehydrogenase inhibitors.

BACKGROUND: Succinate dehydrogenase inhibitor (SDHI) fungicides are an important class of agricultural fungicides with the advantages of high efficiency and a broad bactericidal spectrum. To pursue novel SDHIs, a series of N-substituted dithiin tetracarboximide derivatives were designed, synthesized, and characterized by 1 H NMR, 13 C NMR, and high resolution mass spectrum (HRMS). RESULTS: These engineered compounds displayed potent fungicidal activity against phytopathogens, including Sclerotinia sclerotiorum, Botrytis cinerea, and Rhizoctonia solani, comparable with that of the commercial SDHI fungicide boscalid. In particular, compound 18 stood out with prominent activity against S. sclerotiorum with a half-maximal effective concentration (EC50 ) value of 1.37 µg ml-1 . Compound 1 exhibited the most potent antifungal activity against B. cinerea with EC50 values of 5.02 µg ml-1 . As for R. solani, 12 and 13 exhibited remarkably inhibitory activity with EC50 values of 4.26 and 5.76 µg ml-1 , respectively. In the succinate dehydrogenase (SDH) inhibition assay, 13 presented significant inhibitory activity with a half-maximal inhibitory concentration (IC50 ) value of 15.3 µm, which was approximately equivalent to that of boscalid (14.2 µm). Furthermore, molecular docking studies revealed that 13 could anchor in the binding site of SDH. CONCLUSION: Taken together, results suggested that the dithiin tetracarboximide scaffold possessed a huge potential to be developed as novel fungicides and SDHIs. © 2023 Society of Chemical Industry.

Targeted elimination of senescent cells by engineered extracellular vesicles attenuates atherosclerosis in ApoE-/- mice with minimal side effects.

Senescent cells in plaques emerge as a detrimental factor for atherosclerosis (AS), for which targeted senolysis might be a promising therapeutic strategy. The development of safe and efficient senolytics for senescent cell eradication by targeted delivery is greatly needed. Methods: Pro-apoptotic intelligent Bax (iBax)-overexpressing plasmid was constructed by molecular cloning, in which Bax CDS was fused to miR-122 recognition sites. Extracellular vesicle-based senolytics (EViTx) were developed to be conjugated with magnetic nanoparticles on the surface, iBax mRNA encapsulated inside, and BAX activator BTSA1 incorporated into the membrane. EViTx was characterized, and in vivo distribution was tracked via fluorescence imaging. The therapeutic effects of EViTx on AS and its systemic side effects were analyzed in ApoE-/- mice. Results: Magnetic nanoparticles, iBax mRNA and BAX activator BTSA1 were efficiently loaded into/onto EViTx. With external magnetic field navigation, EViTx was delivered into atherosclerotic plaques and induced significant apoptosis in senescent cells regardless of origins. Repeated delivery of EViTx via tail vein injection has achieved high therapeutic efficacy in ApoE-/- mice. Notably, EViTx is inevitably accumulated in liver cells, while the iBax mRNA was translationally repressed by miR-122, an endogenous miRNA highly expressed in hepatocytes, and thus the liver cells are protected from the potential toxicity of Bax mRNA. Conclusion: Our work demonstrated that magnetic EV-based delivery of iBax mRNA and the BAX activator BTSA1, efficiently induced apoptosis in recipient senescent cells in atherosclerotic plaques. This strategy represents a promising treatment approach for AS and other age-related diseases.

Exosome-Based Mitochondrial Delivery of circRNA mSCAR Alleviates Sepsis by Orchestrating Macrophage Activation.

Sepsis is one of the most common causes of death, which is closely related to the uncontrolled systemic inflammation. Dysregulation of M1 macrophage polarization is the primary contributor to serious inflammation. In this study, it is revealed that the murine homologue of circRNA SCAR (steatohepatitis-associated circRNA ATP5B regulator), denoted as circRNA mSCAR hereafter, decreases in the macrophages of septic mice, which correlates with the excessive M1 polarization. To restore circRNA mSCAR in mitochondria, exosomes encapsulated with circRNA mSCAR are further electroporated with poly-D-lysine-graft-triphenylphosphine (TPP-PDL), and thus TPP-PDL facilitates the bound circRNA delivered into mitochondria when the exosomes engulf by the recipient cells. In in vivo septic mouse model and in vitro cell model, it is shown that the exosome-based mitochondria delivery system delivers circRNA mSCAR into mitochondria preferentially in the macrophages, favoring macrophage polarization toward M2 subtype. Accordingly, the systemic inflammation is attenuated by exosome-based mitochondrial delivery of circRNA mSCAR, together with alleviated mortality. Collectively, the results uncover the critical role of circRNA mSCAR in sepsis, and provide a promising approach to attenuate sepsis via exosome-based mitochondrial delivery of circRNA mSCAR.