hUC-MSCs-derived MFGE8 ameliorates locomotor dysfunction via inhibition of ITGB3/ NF-κB signaling in an NMO mouse model.

Neuromyelitis optica (NMO) is a severe autoimmune inflammatory disease of the central nervous system that affects motor function and causes relapsing disability. Human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) have been used extensively in the treatment of various inflammatory diseases, due to their potent regulatory roles that can mitigate inflammation and repair damaged tissues. However, their use in NMO is currently limited, and the mechanism underlying the beneficial effects of hUC-MSCs on motor function in NMO remains unclear. In this study, we investigate the effects of hUC-MSCs on the recovery of motor function in an NMO systemic model. Our findings demonstrate that milk fat globule epidermal growth 8 (MFGE8), a key functional factor secreted by hUC-MSCs, plays a critical role in ameliorating motor impairments. We also elucidate that the MFGE8/Integrin αvß3/NF-κB signaling pathway is partially responsible for structural and functional recovery, in addition to motor functional enhancements induced by hUC-MSC exposure. Taken together, these findings strongly support the involvement of MFGE8 in mediating hUC-MSCs-induced improvements in motor functional recovery in an NMO mouse model. In addition, this provides new insight on the therapeutic potential of hUC-MSCs and the mechanisms underlying their beneficial effects in NMO.

[Human umbilical cord mesenchymal stem cell-derived exosomes alleviate pulmonary fibrosis in mice by inhibiting epithelial-mesenchymal transition].

OBJECTIVE: To study the anti- fibrotic effect of human umbilical cord mesenchymal stem cell-derived exosomes (hUCMSC-EXOs) and explore the mechanism. METHODS: Twenty-four C57 BL/6 mice were divided into 4 groups (n=6), including the control group treated with intratracheal injection of saline (3 mg/kg); lung fibrosis model group with intratracheal injection of 1.5 mg/mL bleomycin solution (prepared with saline, 3 mg/kg); EXOs1 group with intratracheal injection of 1.5 mg/mL bleomycin solution (3 mg/kg) and hUCMSC-EXOs (100 µg/250 µL, given by tail vein injection on the next day after modeling); and EXOs2 group with intratracheal injection of 1.5 mg/mL bleomycin solution (3 mg/kg) and hUCMSC-EXOs (100 µg/250 µL, given by tail vein injection on the 10th day after modeling). At 21 days after modeling, pulmonary index, lung tissue pathology and collagen deposition in the mice were assessed using HE staining and Masson staining. The expression level of TGF-ß1 was detected using ELISA, and vimentin, E-cadherin and phosphorylated Smad2/3 (p-Smad2/3) were detected using immunohistochemical staining. CCK8 assay was used to evaluate the effect of hUCMSCEXOs on the viability of A549 cells, and Western blotting was used to detect the expression levels of p-Smad2/3, vimentin, and E-cadherin in the cells. RESULTS: Compared with those in the model group, the mice treated with hUCMSC-EXOs showed significantly reduced the pulmonary index (P < 0.05), collagen deposition, lung tissue pathologies, lowered expressions of TGF-ß1 (P < 0.05), vimentin, and p-Smad2/3 and increased expression of E-cadherin. hUCMSC-EXOs given on the second day produced more pronounced effect than that given on the 11th day (P < 0.05). CCK8 assay results showed that hUCMSC-EXOs had no toxic effects on A549 cells (P > 0.05). Western blotting results showed that hUCMSC-EXOs treatment significantly increased the expression of E-cadherin and decreased the expressions of p-Smad2/3 and vimentin in the cells. CONCLUSIONS: hUCMSC-EXOs can alleviate pulmonary fibrosis in mice by inhibiting epithelialmesenchymal transition activated by the TGF-ß1/Smad2/3 signaling pathway, and the inhibitory effect is more obvious when it is administered on the second day after modeling.

Pretreatment of exosomes derived from hUCMSCs with TNF-α ameliorates acute liver failure by inhibiting the activation of NLRP3 in macrophage.

AIMS: The management of acute liver failure (ALF) is a major challenge worldwide. The current study aimed to determine the therapeutic potential of TNF-α pretreatment of umbilical cord mesenchymal stem cell-derived exosomes (T-Exo) in ALF. MAIN METHODS: Here, we enriched T-Exo and untreated exosomes (Exo), them were measured by nanoparticle tracking analysis (NTA) for particle size detection and identified surface marker by Western blot and flow cytometry. Then the cell proliferation was detected by CCK-8 and the effect of T-Exo on the expression levels of pro-inflammatory cytokines was tested by ELISA. ALF mouse models were induced by LPS and D-GalN. H&E staining, immunohistochemistry, and Western blot were used to detect the effect of T-Exo on the levels of NLRP3 and other inflammation-related pathway proteins. qPCR was used to detect the expression level of microRNA-299-3p in T-Exo and its transfer to macrophages. Laser confocal microscopy was used to detect colocalization of exosomes,Golgi and NLRP3 in macrophages. KEY FINDINGS: Our study shows that T-Exo can reduce serum ALT, AST and proinflammatory cytokines level and inhibit activation of NLRP3 inflammation-associated pathway proteins. T-Exo treatment reduces pathological liver damage caused by ALF. Anti-inflammatory-related miRNA-299-3p is up-regulated in TNF-α-stimulated MSCs and selectively packaged into exosomes for role in exosomal treatment. And conducted preliminary exploration and hypothesis on the specific mechanism of this effect. SIGNIFICANCE: These in vitro and in vivo studies indicate that T-Exo attenuates inflammatory damage caused by ALF and promotes liver tissue repair by inhibiting the activation of the NLRP3 pathway.

Exosomes derived from human umbilical cord mesenchymal stem cells alleviate acute liver failure by reducing the activity of the NLRP3 inflammasome in macrophages.

Human umbilical cord mesenchymal stem cell-derived exosomes (hUCMSC-EXOs) play an important role in the regulation of the immune system and inflammatory responses; however, their role in acute liver failure (ALF) and related pathological conditions is unclear. In this study, we found that hUCMSC-EXOs can reduce the expression of the NLRP3 inflammasome and downstream inflammatory factors in acute liver failure. Western blot and ELISA results showed that hUCMSC-EXOs decreased the expression of NLRP3, caspase-1, IL-1ß and IL-6 in LPS-stimulated RAW 264.7 macrophages. In vivo, the hUCMSC-EXOs repaired damaged liver tissue and decreased the expression of the NLRP3 inflammasome and the levels of ALT and AST in a mouse ALF model. The results of this study provide a new strategy for the application of human umbilical cord mesenchymal stem cell-derived exosomes in the treatment of ALF.

[DREAM: a multifunctional transcriptional regulator].

DREAM (downstream regulatory element antagonist modulator), Calsenilin and KChIP3 (potassium channel interacting protein 3) belong to the neuronal calcium sensor (NCS) superfamily, which transduces the intracellular calcium signaling into a variety of activities. They are encoded by the same gene locus, but have distinct subcellular locations. DREAM was first found to interact with DRE (downstream regulatory element) site in the vicinity of the promoter of prodynorphin gene to suppress gene transcription. Calcium can disassemble this interaction by binding reversibly to DREAM protein on its four EF-hand motifs. Apart from having calcium dependent DRE site binding, DREAM can also interact with other transcription factors, such as cAMP responsive element binding protein (CREB), CREB-binding protein (CBP) and cAMP responsive element modulator (CREM), by this concerted actions, DREAM extends the gene pool under its control. DREAM is predominantly expressed in central nervous system with its highest level in cerebellum, and accumulating evidence demonstrated that DREAM might play important roles in pain sensitivity. Novel findings have shown that DREAM is also involved in learning and memory processes, Alzheimer's disease and stroke. This mini-review provides a brief introduction of its discovery history and protein structure properties, focusing on the mechanism of DREAM nuclear translocation and gene transcription regulation functions.