Migrasomes are newly discovered extracellular vesicles (EVs) that are formed in migrating cells and mediate intercellular communication. However, their size, biological generation, cargo packaging, transport, and effects on recipient cells by migrasomes are different from those of other EVs. In addition to mediating organ morphogenesis during zebrafish gastrulation, discarding damaged mitochondria, and lateral transport of mRNA and proteins, growing evidence has demonstrated that migrasomes mediate a variety of pathological processes. In this review, we summarize the discovery, mechanisms of formation, isolation, identification, and mediation of cellular communication in migrasomes. We discuss migrasome-mediated disease processes, such as osteoclast differentiation, proliferative vitreoretinopathy, tumor cell metastasis by PD-L1 transport, immune cell chemotaxis to the site of infection by chemokines, angiogenesis promotion via angiogenic factors by immune cells, and leukemic cells chemotaxis to the site of mesenchymal stromal cells. Moreover, as new EVs, we propose the potential of migrasomes for disease diagnosis and treatment.

Background: Accumulating evidence shows that mesenchymal stem cells (MSCs) have the potential as a cellular therapy avenue for schistosome-induced liver injury. Extracellular vesicles (EVs) are membranous vesicles released by almost all cell types, and EVs produced by MSCs (MSC-EVs) exert therapeutic effects in several disease models. However, the potential of MSC-EVs in schistosomiasis treatment remains unclear. Methods: Using survival analysis, HE and Masson’s trichrome staining, immunohistochemical, western blot analysis, real-time PCR, and EdU proliferation, we investigated the effects of human umbilical cord MSC-derived EVs (hUCMSC-EVs) on the survival and liver injury in the S. japonicum-infected mice and explored the underlying mechanism. Results: Here, we found that like hUCMSCs, hUCMSC-EVs significantly ameliorated liver injury and improved the survival of schistosome-infected mice. Indeed, the hUCMSC-EV-mediated alleviation of liver injury is associated with decreased expression of α-smooth muscle actin (α-SMA), collagen 1, and collagen 3. More importantly, we showed that hUCMSC-EVs directly suppressed the proliferation of LX2 (human hepatic stellate cell) in vitro. In addition, hUCMSC-EVs significantly downregulated the activation of LX2 after transforming growth factor-β1 (TGF-β1) treatment. Conclusion: Our results provided the first evidence that hUCMSC-EVs reduced liver injury in S. japonicum-infected mice, potentially creating new avenues for the treatment of liver damage in schistosomiasis.

Background: Harnessing helminth-based immunoregulation is a novel therapeutic strategy for many immune dysfunction disorders, including inflammatory bowel diseases (IBDs). We previously identified a small molecule peptide from Schistosoma japonicum and named it SJMHE1. SJMHE1 can suppress delayed-type hypersensitivity, collagen-induced arthritis and asthma in mice. In this study, we assessed the effects of SJMHE1 on dextran sulfate sodium (DSS)-induced acute and chronic colitis. Methods: Acute and chronic colitis were induced in C57BL/6 mice by DSS, following which the mice were injected with an emulsifier SJMHE1 or phosphate-buffered saline. The mice were then examined for body weight loss, disease activity index, colon length, histopathological changes, cytokine expression and helper T (Th) cell subset distribution. Results: SJMHE1 treatment significantly suppressed DSS-induced acute and chronic colitis, improved disease activity and pathological damage to the colon and modulated the expression of pro-inflammatory and anti-inflammatory cytokines in splenocytes and the colon. In addition, SJMHE1 treatment reduced the percentage of Th1 and Th17 cells and increased the percentage of Th2 and regulatory T (Treg) cells in the splenocytes and mesenteric lymph nodes of mice with acute colitis. Similarly, SJMHE1 treatment upregulated the expression of interleukin-10 (IL-10) mRNA, downregulated the expression of IL-17 mRNA and modulated the Th cell balance in mice with chronic colitis. Conclusions: Our data show that SJMHE1 provided protection against acute and chronic colitis by restoring the immune balance. As a small molecule, SJMHE1 might be a novel agent for the treatment of IBDs without immunogenicity concerns. Graphical

Asthma is a prevalent respiratory disease, and its management remains largely unsatisfactory. Mesenchymal stem cells (MSCs) have been demonstrated to be efficacious in reducing airway inflammation in experimental allergic diseases, representing a potential alternative treatment for asthma. Migrasomes are recently identified extracellular vesicles (EVs) generated in migrating cells and facilitate intercellular communication. The objective of this study was to investigate the therapeutic effects of migrasomes obtained from MSC in a model of asthma. Migrasomes produced by human umbilical cord MSCs (hUCMSCs) were isolated by sequential centrifugation. Characterization of hUCMSC-derived migrasomes were carried out by transmission electron microscopy and western blot analysis. The therapeutic effects of migrasomes on airway inflammation in ovalbumin (OVA)-induced asthmatic mice were evaluated by hematoxylin-eosin (HE) and periodic-acid schiff (PAS) staining, and their mechanism were further testified by immunofluorescent staining, real-time PCR and flow cytometry. Here, we showed that inhibition of migrasomes’ production dramatically impaired the anti-inflammatory effects of hUCMSCs in OVA animals, as evidenced by a notable increase in both the infiltration of inflammatory cells and the number of epithelial goblet cells. We successfully isolated hUCMSC-migrasomes, which were morphologically intact and positive for the specific migrasomes markers. The administration of hUCMSC-migrasomes was observed to significantly ameliorate the symptoms of airway inflammation and mucus production in asthmatic mice. Additionally, the expression of Th2 cytokines (IL-4, IL-5 and IL-13) were found to be reduced, while the activation of dendritic cells (DCs) was inhibited. HUCMSC-migrasomes could possibly be delivered to lung region after injection, and were able to be taken in by DCs both in vivo and in vitro. Notably, in vitro, migraosmes decreased the capacity of BMDCs to stimulate OVA-specific Th2-cell responses. More importantly, we found that adoptive transfer of hUCMSC-migrasomes-treated BMDCs was sufficient to protect mice from allergic airway inflammation. In addition, we found that hUCMSC-migrasomes inhibited the receptor for advanced glycation end-products (RAGE) signal in OVA-treated BMDCs in vitro and in asthma mice lung in vivo. Our results provided the first evidence that hUCMSC-migrasomes possess anti-inflammatory properties in OVA-induced allergic mice, which may provide a novel “MSC-cell free” therapeutic agent for the management of asthma.

Inflammatory factors exert a significant role in the development of adult-onset Still’s disease (AOSD) and sepsis. Although platelet counts and platelet parameters have long served as indicators for inflammatory diseases, their role in the differential diagnosis between adult-onset stilĺs disease and sepsis remains unclear. We designed this retrospective study to explore whether the platelet to mean platelet volume (MPV) ratio (PMR) can help to distinguish AOSD from sepsis. A total of 110 AOSD patients and 84 sepsis patients were enrolled in the study. Seventy-three AOSD patients and 56 sepsis patients between January 2010 and June 2017 were enrolled in the test cohort to analyze PMR values, which was then validated in the validation cohort (37 AOSD patients and 28 sepsis patients between June 2017 and December 2019). The values of PMR were significantly higher in AOSD patients than in sepsis patients (test cohort, validation cohort, and entire cohort), In the test cohort, logistic regression analysis showed that PMR was an independent risk factor of AOSD (odds ratios [OR]: 9.22, 95% confidence interval [CI] 2.15-39.46, p=0.003). Further receiver operating characteristic curve (ROC) analysis showed that the area under the ROC curve was 0.735 (95% CI 0.631-0.839, p<0.001) for PMR alone and 0.925 (95% CI 0.869-0.980, p<0.001) for the combination of PMR and serum ferritin. Consistently, the validation cohort exhibited analogous results. PMR could be used as a single indicator or a complementary indicator to distinguish AOSD from sepsis.