BMSC-derived exosomal miR-148b-3p attenuates OGD/R-induced HMC3 cell activation by targeting DLL4 and Notch1

Microglial Responses to MSC-EVs Treatment in Animal and Cellular Models of Ischemic Stroke: a Systematic Review with Meta-analysis

The modulation of microglial reactivity has emerged as a potential target for developing ischemic stroke therapies. Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) possess immunomodulatory properties that may influence microglial responses following ischemia. However, individual studies assessing this influence have provided limited results. Therefore, we conducted a systematic review and meta-analysis to investigate whether MSC-EVs treatment alters microglial responses in animal and cellular models of ischemic stroke. In accordance with the PRISMA 2020 statement, we searched PubMed, Web of Science, and EMBASE until October 2023 for studies assessing cellular and molecular parameters of microglial reactivity following MSC-EVs treatment in models of ischemic stroke. We estimated treatment effects using a random-effects meta-analysis of standardized mean differences and estimated heterogeneity via the I2 statistic. The risk of bias was assessed using the SYRCLE questionnaire. The search identified 297 studies, 27 of which met the inclusion criteria. In animal models, MSC-EVs reduced the number, surface area, and fluorescence intensity of Iba1+ cells, as well as the number of Iba1+ cells co-expressing the pro-inflammatory markers CD16, CD32, CD85, and iNOS. Conversely, MSC-EVs increased the number of Iba1+ cells co-expressing the anti-inflammatory markers Arg-1 and CD206. In cellular models, we observed decreased concentrations of TNF-α, IL-1β, and IL-6 in the culture medium. Our meta-analysis consolidates the immunomodulatory effects of MSC-EVs on microglial responses to ischemia, underscoring the potential of microglia-specific therapeutics in the development of MSC-EVs-based and regenerative treatments for ischemic stroke.

Adipose-derived stem cell exosomal miR-21-5p enhances angiogenesis in endothelial progenitor cells to promote bone repair via the NOTCH1/DLL4/VEGFA signaling pathway

BACKGROUND

Angiogenesis is essential for repairing critical-sized bone defects. Although adipose-derived stem cell (ADSC)-derived exosomes have been shown to enhance the angiogenesis of endothelial progenitor cells (EPCs), the underlying mechanisms remain unclear. This study aims to explore the effects and mechanisms of ADSC-derived exosomes in enhancing bone repair by promoting EPC angiogenesis.

METHODS

Transmission electron microscopy, nanoparticle tracking analysis, and Dil reagent kit were employed to identify ADSC-derived exosomes and their internalization by EPCs. Micro-CT analysis, H&E staining, and Masson staining were used to assess bone mineral density (BMD), bone volume fraction (BV/TV), trabecular thickness (Tb.Th), and trabecular number (Tb.N), as well as the pathological changes and fibrosis at defect sites. Cell viability, migration, invasion, and tube formation of EPCs were evaluated using CCK-8, wound healing, Transwell, and tube formation assays. Immunohistochemical staining, RT-PCR, and Western blotting were utilized to measure the gene and protein expression of markers such as CD31, VEGFA, OCN, RUNX2, NOTCH1, and DLL4. Gene sequencing and bioinformatics analyses were conducted to identify the most highly expressed miRNA in exosomes, while miRDB and dual-luciferase reporter assays were used to explore the interaction between miR-21-5p and NOTCH1.

RESULTS

The ADSC-derived exosomes, averaging 126 nm in diameter, were internalized by EPCs. In vivo, these exosomes promoted new bone formation, increased BMD, BV/TV, Tb.Th, and Tb.N, reduced pathological damage to cranial defect tissues, enhanced vascular and bone tissue regeneration, and upregulated OCN and RUNX2 expression. In vitro, ADSC-derived exosomes enhanced EPC viability, migration, invasion, and tube formation. Both in vivo and in vitro experiments demonstrated that ADSC-derived exosomes upregulated CD31 and VEGFA expression. miR-21-5p, the most highly expressed miRNA in ADSC-derived exosomes, was found to target NOTCH1. Overexpression of miR-21-5p in these exosomes facilitated EPC migration, tube formation, and VEGFA expression while downregulating NOTCH1 and DLL4 expression. Inhibition of miR-21-5p produced opposite effects on EPCs.

CONCLUSIONS

These findings indicate that miR-21-5p in ADSC-derived exosomes promotes angiogenesis in EPCs to accelerate bone repair by targeting the NOTCH1/DLL4/VEGFA signaling pathway, offering a potential therapeutic strategy for bone defect treatment.

Exosomes as Vehicles for Noncoding RNA in Modulating Inflammation: A Promising Regulatory Approach for Ischemic Stroke and Myocardial Infarction

Exosomes have grown as promising carriers for noncoding RNAs (ncRNAs) in the treatment of inflammation, particularly in conditions like ischemic stroke and myocardial infarction. These ncRNAs, which include microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), play a crucial role in regulating inflammatory pathways, presenting new therapeutic opportunities. In both ischemic stroke and myocardial infarction, inflammation significantly influences disease progression and severity. Exosomes can deliver ncRNAs directly to specific cells and tissues, providing a targeted approach to modulate gene expression and reduce inflammation. Their biocompatibility and low risk of inducing immune responses make exosomes ideal therapeutic vehicles. Ongoing research is focused on optimizing the loading of ncRNAs into exosomes, ensuring efficient delivery, and understanding the mechanisms by which these ncRNAs mitigate inflammation. In ischemic stroke, exosome-derived ncRNAs originate from various cell types, including neurons, M2 microglia, patient serum, genetically engineered HEK293T cells, and mesenchymal stromal cells. In the case of myocardial infarction, these ncRNAs are sourced from mesenchymal stem cells, endothelial cells, and patient plasma. These exosome-loaded ncRNAs play a significant role in modulating inflammation in both ischemic stroke and myocardial infarction. As this research advances, therapies based on exosomes may completely change how diseases linked to inflammation are treated, offering new avenues for patient care and recovery. This review explores the latest advancements in understanding how exosomes impact specific inflammatory components, with a particular emphasis on the role of ncRNAs contained in exosomes. The review concludes by highlighting the clinical potential of exosome-derived ncRNAs as innovative therapeutic and diagnostic tools.

GATA-4 overexpressing BMSC-derived exosomes suppress H/R-induced cardiomyocyte ferroptosis

Bone marrow mesenchymal stem cell (BMSC)-derived exosomes overexpressing GATA-4 (Exosoe-GATA-4) can protect cardiac function. Mitochondrial permeability transition pore (mPTP) has a crucial role in ferroptosis. This study aimed to assess the mechanism of Exosoe-GATA-4 in myocardial ischemia/reperfusion (I/R) injury. Exos were successfully excreted, and 185 differential expression miRNAs were obtained using bioinformatics. The Exosoe-GATA-4 effectively suppressed hypoxia/reoxygenation (H/R)-induced cardiomyocytes' ferroptosis, while the effects were reversed by miR-330-3p inhibitor. miR-330-3p targeted negative regulated BAP1. The effects of miR-330-3p inhibitor were reversed by knock-down BAP1. Also, BAP1 reversed the effects of Exosoe-GATA-4 on H/R-induced cardiomyocytes' ferroptosis by downregulating SLC7A11. Mechanistically, BAP1 interacted with IP3R and increased cardiomyocytes' Ca2+ level, causing mPTP opening and mitochondrial dysfunction, promoting H/R-induced cardiomyocytes' ferroptosis. Moreover, hydrogen sulfide (H2S) content was increased and regulated the keap1/Nrf2 signaling pathway by Exosoe-GATA-4 treated. Exosoe-GATA-4 effectively suppresses H/R-induced cardiomyocytes' ferroptosis by upregulating miR-330-3p, which regulates the BAP1/SLC7A11/IP3R axis and inhibits mPTP opening.

Effects of Bone Marrow Mesenchymal Stem Cell-Derived Exosomes in Central Nervous System Diseases

Central nervous system (CNS) diseases are one of the diseases that threaten human health. The delivery of drugs targeting the CNS has always been a significant challenge; the blood-brain barrier (BBB) is the main obstacle that must be overcome. The rise of bone marrow mesenchymal stem cell (BMSC) therapy has brought hope for the treatment of CNS diseases. However, the problems of low homing rate, susceptibility differentiation into astrocytes, immune rejection, and formation of iatrogenic tumors of transplanted BMSCs limit their clinical application. Bone marrow mesenchymal stem cell-derived exosomes (BMSC-Exos) have become a hot research topic in the treatment of CNS diseases in recent years because of their excellent histocompatibility, low immunogenicity, ease of crossing the BBB, and their ability to serve as natural carriers for treatment. This article reviews the mechanisms of BMSC-Exos in CNS diseases and provides direction for further research.

Reveal the correlation between hub hypoxia/immune-related genes and immunity and diagnosis, and the effect of SAP30 on cell apoptosis, ROS and MDA production in cerebral ischemic stroke

BACKGROUND

Cerebral ischemic stroke (CIS) is a common cerebrovascular disease. The purpose of this study was to investigate the potential mechanism of hypoxia and immune-related genes in CIS.

METHODS

All data were downloaded from public databases. Hub mRNAs was identified by differential expression analysis, WGCNA analysis and machine learning. Hub mRNAs were used to construct the classification models. Pearson correlation analysis was used to analyze the correlation between hub mRNAs and immune cell infiltration. Finally, the SAP30 was selected for verification in HMC3 cells.

RESULTS

The SVM, RF and DT classification models constructed based on 6 hub mRNAs had higher area under the curve values, which implied that these classification models had high diagnostic accuracy. Pearson correlation analysis found that Macrophage has the highest negative correlation with CCR7, while Neutrophil has the highest positive correlation with SLC2A3. Drug prediction found that ruxolitinib, methotrexate, resveratrol and resatorvid may play a role in disease treatment by targeting different hub mRNAs. Notably, inhibition of SAP30 expression can reduce the apoptosis of HMC3 cells and inhibit the production of ROS and MDA.

CONCLUSION

The identification of hub miRNAs and the construction of classification diagnosis models provide a theoretical basis for the diagnosis and management of CIS.