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Conditions to which the cardiac graft is exposed during transplantation with donation after circulatory death (DCD) can trigger the recruitment of macrophages that are either unpolarized (M0) or pro‐inflammatory (M1) as well as the release of extracellular vesicles (EV). We aimed to characterize the effects of M0 and M1 macrophage‐derived EV administration on post‐ischaemic functional recovery and glucose metabolism using an isolated rat heart model of DCD. Isolated rat hearts were subjected to 20 min aerobic perfusion, followed by 27 min global, warm ischaemia or continued aerobic perfusion and 60 min reperfusion with or without intravascular administration of EV. Four experimental groups were compared: (1) no ischaemia, no EV; (2) ischaemia, no EV; (3) ischaemia with M0‐macrophage‐dervied EV; (4) ischaemia with M1‐macrophage‐derived EV. Post‐ischaemic ventricular and metabolic recovery were evaluated. During reperfusion, ventricular function was decreased in untreated ischaemic and M1‐EV hearts, but not in M0‐EV hearts, compared to non‐ischaemic hearts (p < 0.05). In parallel with the reduced functional recovery in M1‐EV versus M0‐EV ischaemic hearts, rates of glycolysis from exogenous glucose and oxidative metabolism tended to be lower, while rates of glycogenolysis and lactate release tended to be higher. EV from M0‐ and M1‐macrophages differentially affect post‐ischaemic cardiac recovery, potentially by altering glucose metabolism in a rat model of DCD. Targeted EV therapy may be a useful approach for modulating cardiac energy metabolism and optimizing graft quality in the setting of DCD.

The emergence of monkeypox has become a global health threat after the COVID‐19 pandemic. Due to the lack of available specifically treatment against MPV, developing an available vaccine is thus the most prospective and urgent strategy. Herein, a programmable macrophage vesicle based bionic self‐adjuvanting vaccine (AM@AEvs‐PB) is first developed for defending against monkeypox virus (MPV). Based on MPV‐related antigen‐stimulated macrophage‐derived vesicles, the nanovaccine is constructed by loading the mature virion (MV)‐related intracellular protein (A29L/M1R) and simultaneously modifying with the enveloped virion (EV) antigen (B6R), enabling them to effectively promote antigen presentation and enhance adaptive immune through self‐adjuvant strategy. Owing to the synergistic properties of bionic vaccine coloaded MV and EV protein in defensing MPV, the activation ratio of antigen‐presenting cells is nearly four times than that of single antigen in the same dose, resulting in stronger immunity in host. Notably, intramuscular injection uptake of AM@AEvs‐PB demonstrated vigorous immune‐protective effects in the mouse challenge attempt, offering a promising strategy for pre‐clinical monkeypox vaccine development. The monkeypox‐specific bionic vaccine (AM@AEvs‐PB) is consists of IMV antigens (A29L, M1R), the EEV antigen (B6R), and MPV‐preactivated macrophagederived vesicles. AM@AEvs‐PB can induce enhanced innate immune responses, promote cross‐presentation of antigens to dendritic cells (DCs), and elicit robust adaptive immune responses, realizing immunization protection against Monkeypox Virus.

Tumour cell metastasis can be genetically regulated by proteins contained in cancer cell-derived extracellular vesicles (EVs) released to the tumour microenvironment. Here, we found that the number of infiltrated macrophages was positively correlated with the expression of signal-induced proliferation-associated 1 (SIPA1) in invasive breast ductal carcinoma tissues and MDA-MB-231 xenograft tumours. EVs derived from MDA-MB-231 cells (231-EVs) significantly enhanced macrophage migration, compared with that from SIPA1-knockdown MDA-MB-231 cells (231/si-EVs) both in vitro and in vivo. We revealed that SIPA1 promoted the transcription of MYH9, which encodes myosin-9, and up-regulated the expression level of myosin-9 in breast cancer cells and their EVs. We also found that blocking myosin-9 by either down-regulating SIPA1 expression or blebbistatin treatment led to the suppression of macrophage infiltration. Survival analysis showed that breast cancer patients with high expression of SIPA1 and MYH9 molecules had worse relapse-free survival (p = 0.028). In summary, SIPA1high breast cancer can enhance macrophage infiltration through EVs enriched with myosin-9, which might aggravate the malignancy of breast cancer.

Reversing the tumor microenvironment (TME) from “cold” to “hot” tumor represents a pivotal strategy to overcome the clinical bottleneck of poor response rates to immunotherapy in solid tumors. Herein, we innovatively employed a macrophage bioreactor to induce M0 macrophage polarization and the secretion of functional extracellular vesicles (M1‐EVs) through co‐incubation with hollow mesoporous silica nanoparticles loaded with the aggregation‐induced emission photothermal agent AXCB6 and the IDO1 inhibitor NLG919. Notably, this in‐situ bioengineering approach preserves the inherent biological properties and activity stability of functional agents’ components. Upon near‐infrared irradiation, AXCB6 induces direct tumor cell death via photothermal therapy (PTT) and elicits immunogenic cell death, which subsequently triggers both in‐situ vaccine responses and systemic immunity. Concomitantly, NLG919 inhibits the activity of PTT‐driven IDO1 overexpression, reversing tryptophan metabolism‐mediated immune suppression. Additionally, bioengineered M1‐EVs with inherent repolarization capacity further reshape the inflammatory microenvironment and synergize with IDO1 blockade to potentiate immune activation. Through this cascaded amplification, the triple combination therapy exhibits superior therapeutic efficacy and favorable safety profiles compared to monotherapy and dual‐drug combinations in both in vitro and in vivo. These findings indicate that the EV‐integrated multi‐dimensional system offers a promising strategy for converting “cold” tumors to “hot” tumors via Poseidon's “trident” mechanism: PTT‐mediated physical ablation—repolarization‐driven TME remodeling—immune checkpoint intervention. Illustration of A/I@REHM nanoparticles preparation (A) and “ICB ‐ Repolarization ‐ PTT” like Poseidon's trident synergistically anti‐tumor treatment (B).

Helminth coinfection with tuberculosis (TB) can alter the phenotype and function of macrophages, which are the major host cells responsible for controlling (Mtb). However, it is not known whether helminth infection stimulates the release of host-derived extracellular vesicles (EVs) to induce or maintain their regulatory network that suppresses TB immunity. We previously showed that pre-exposure of human monocyte-derived macrophages (hMDMs) with protein antigens (ASC) results in reduced Mtb infection-driven proinflammation and gained bacterial control. This effect was entirely dependent on the presence of soluble components in the conditioned medium from helminth antigen-pre-exposed macrophages. Our objective was to investigate the role of EVs released from helminth antigen-exposed hMDMs on Mtb-induced proinflammation and its effect on Mtb growth in hMDMs. Conditioned medium from 48-h pre-exposure with ASC or antigen (SM) was used to isolate EVs by ultracentrifugation. EVs were characterized by immunoblotting, flow cytometry, nanoparticle tracking assay, transmission electron microscopy, and a total of 377 microRNA (miRNA) from EVs screened by TaqMan array. Luciferase-expressing Mtb H37Rv was used to evaluate the impact of isolated EVs on Mtb growth control in hMDMs. EV characterization confirmed double-membraned EVs, with a mean size of 140 nm, expressing the classical exosome markers CD63, CD81, CD9, and flotillin-1. Specifically, EVs from the ASC conditioned medium increased the bacterial control in treatment-naïve hMDMs and attenuated Mtb-induced IL-1β at 5 days post-infection. Four miRNAs showed unique upregulation in response to ASC exposure in five donors. Pathway enrichment analysis showed that the MAPK and PI3K-AKT signaling pathways were regulated. Among the mRNA targets, relevant for regulating inflammatory responses and cellular stress pathways, CREB1 and MAPK13 were identified. In contrast, SM exposure showed significant regulation of the TGF-β signaling pathway with SMAD4 as a common target. Overall, our findings suggest that miRNAs in EVs released from helminth-exposed macrophages regulate important signaling pathways that influence macrophage control of Mtb and reduce inflammation. Understanding these interactions between helminth-induced EVs, miRNAs, and macrophage responses may inform novel therapeutic strategies for TB management.

Immunosuppression at tumor microenvironment (TME) is one of the major obstacles to be overcome for an effective therapeutic intervention against solid tumors. Tumor-associated macrophages (TAMs) comprise a sub-population that plays multiple pro-tumoral roles in tumor development including general immunosuppression, which can be identified in terms of high expression of mannose receptor (MR or CD206). Immunosuppressive TAMs, like other macrophage sub-populations, display functional plasticity that allows them to be re-programmed to inflammatory macrophages. In order to mitigate immunosuppression at the TME, several efforts are ongoing to effectively re-educate pro-tumoral TAMs. Extracellular vesicles (EVs), released by both normal and tumor cells types, are emerging as key mediators of the cell to cell communication and have been shown to have a role in the modulation of immune responses in the TME. Recent studies demonstrated the enrichment of high mannose glycans on the surface of small EVs (sEVs), a subtype of EVs of endosomal origin of 30–150 nm in diameter. This characteristic renders sEVs an ideal tool for the delivery of therapeutic molecules into MR/CD206-expressing TAMs. In this review, we report the most recent literature data highlighting the critical role of TAMs in tumor development, as well as the experimental evidences that has emerged from the biochemical characterization of sEV membranes. In addition, we propose an original way to target immunosuppressive TAMs at the TME by endogenously engineered sEVs for a new therapeutic approach against solid tumors.

As natural nanocarriers and intercellular messengers, extracellular vesicles (EVs) control communication among cells. Under physiological and pathological conditions, EVs deliver generic information including proteins and nucleic acids to recipient cells and exert regulatory effects. Macrophages help mediate immune responses, and macrophage-derived EVs may play immunomodulatory roles in the progression of chronic inflammatory diseases. Furthermore, EVs derived from various macrophage phenotypes have different biological functions. In this review, we describe the pathophysiological significance of macrophage-derived extracellular vesicles in the development of chronic inflammatory diseases, including diabetes, cancer, cardiovascular disease, pulmonary disease, and gastrointestinal disease, and the potential applications of these EVs.

Macrophages are innate immune cells present in all tissues and play an important role in almost all aspects of the biology of living organisms. Extracellular vesicles (EVs) are released by cells and transport their contents (micro RNAs, mRNA, proteins, and long noncoding RNAs) to nearby or distant cells for cell-to-cell communication. Numerous studies have shown that macrophage-derived extracellular vesicles (M-EVs) and their contents play an important role in a variety of diseases and show great potential as biomarkers, therapeutics, and drug delivery vehicles for diseases. This article reviews the biological functions and mechanisms of M-EVs and their contents in chronic non-communicable diseases such as cardiovascular diseases, metabolic diseases, cancer, inflammatory diseases and bone-related diseases. In addition, the potential application of M-EVs as drug delivery systems for various diseases have been summarized.

Obesity-induced chronic inflammation exacerbates multiple types of tissue/organ deterioration and stem cell dysfunction; however, the effects on skeletal tissue and the underlying mechanisms are still unclear. Here, we show that obesity triggers changes in the microRNA profile of macrophage-secreted extracellular vesicles, leading to a switch in skeletal stem/progenitor cell (SSPC) differentiation between osteoblasts and adipocytes and bone deterioration. Bone marrow macrophage (BMM)-secreted extracellular vesicles (BMM-EVs) from obese mice induced bone deterioration (decreased bone volume, bone microstructural deterioration, and increased adipocyte numbers) when administered to lean mice. Conversely, BMM-EVs from lean mice rejuvenated bone deterioration in obese recipients. We further screened the differentially expressed microRNAs in obese BMM-EVs and found that among the candidates, miR-140 (with the function of promoting adipogenesis) and miR-378a (with the function of enhancing osteogenesis) coordinately determine SSPC fate of osteogenic and adipogenic differentiation by targeting the Pparα-Abca1 axis. BMM miR-140 conditional knockout mice showed resistance to obesity-induced bone deterioration, while miR-140 overexpression in SSPCs led to low bone mass and marrow adiposity in lean mice. BMM miR-378a conditional depletion in mice led to obesity-like bone deterioration. More importantly, we used an SSPC-specific targeting aptamer to precisely deliver miR-378a-3p-overloaded BMM-EVs to SSPCs via an aptamer-engineered extracellular vesicle delivery system, and this approach rescued bone deterioration in obese mice. Thus, our study reveals the critical role of BMMs in mediating obesity-induced bone deterioration by transporting selective extracellular-vesicle microRNAs into SSPCs and controlling SSPC fate. [Display omitted] Please find the highlights of our study as follows.•Obese bone marrow macrophages (BMM)-secreted miRNA-containing extracellular vesicles (BMM-EVs) cause bone deterioration, while lean BMM-EVs rejuvenate bone in obese recipients.•We found BMM-EV miR-140 (with function of promoting adipogenesis) and miR-378a (with function of enhancing osteogenesis) coordinately determine SSPC cell fate of osteogenic and adipogenic differentiation via targeting Pparα-Abca1 axis.•For the first time, we reported the bone phenotype of transgenic mouse models with conditional knockout of miR-378a and miR-140 in BMMs, and conditional overexpression of miR-140 in skeleta stem/progenitor cells.•We used a skeletal stem/progenitor cell (SSPC)-specific targeting aptamer, precisely delivery miR-378a overloaded BMM-EVs to SSPCs using aptamer-engineered extracellular vesicle delivery system, rescued bone deterioration in obese mice.

Despite the efforts and advances done in the last few decades, cancer still remains one of the main leading causes of death worldwide. Nanomedicine and in particular extracellular vesicles are one of the most potent tools to improve the effectiveness of anticancer therapies. In these attempts, the aim of this work is to realize a hybrid nanosystem through the fusion between the M1 macrophages-derived extracellular vesicles (EVs-M1) and thermoresponsive liposomes, in order to obtain a drug delivery system able to exploit the intrinsic tumor targeting capability of immune cells reflected on EVs and thermoresponsiveness of synthetic nanovesicles. The obtained nanocarrier has been physicochemically characterized, and the hybridization process has been validated by cytofluorimetric analysis, while the thermoresponsiveness was in vitro confirmed through the use of a fluorescent probe. Tumor targeting features of hybrid nanovesicles were in vivo investigated on melanoma-induced mice model monitoring the accumulation in tumor site through live imaging and confirmed by cytofluorimetric analysis, showing higher targeting properties of hybrid nanosystem compared to both liposomes and native EVs. These promising results confirmed the ability of this nanosystem to combine the advantages of both nanotechnologies, also highlighting their potential use as effective and safe personalized anticancer nanomedicine. Graphical Abstract