Long-term hypoxic hUCMSCs-derived extracellular vesicles alleviates allergic rhinitis through triggering immunotolerance of their VEGF-mediated inhibition of dendritic cells maturation

Long-term hypoxic atmosphere enhances the stemness, immunoregulatory functions, and therapeutic application of human umbilical cord mesenchymal stem cells

Aims

Mesenchymal stem cells (MSCs) are usually cultured in a normoxic atmosphere (21%) in vitro, while the oxygen concentrations in human tissues and organs are 1% to 10% when the cells are transplanted in vivo. However, the impact of hypoxia on MSCs has not been deeply studied, especially its translational application.

Methods

In the present study, we investigated the characterizations of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) in hypoxic (1%) and normoxic (21%) atmospheres with a long-term culture from primary to 30 generations, respectively. The comparison between both atmospheres systematically analyzed the biological functions of MSCs, mainly including stemness maintenance, immune regulation, and resistance to chondrocyte apoptosis, and studied their joint function and anti-inflammatory effects in osteoarthritis (OA) rats constructed by collagenase II.

Results

We observed that long-term hypoxic culture surpassed normoxic atmosphere during hUC-MSCs culture in respect of promoting proliferation, anti-tumorigenicity, maintaining normal karyotype and stemness, inhibiting senescence, and improving immunoregulatory function and the role of anti-apoptosis in chondrocytes. Furthermore, we demonstrated that the transplantation of long-term hypoxic hUC-MSCs (Hy-MSCs) had a better therapeutic effect on OA rats compared with the hUC-MSCs cultured in the normoxic atmosphere (No-MSCs) in terms of the improved function and swelling recovery in the joints, and substantially inhibited the secretion of pro-inflammatory factors, which effectively alleviated cartilage damage by reducing the expression of matrix metallopeptidase 13 (MMP-13).

Conclusion

Our results demonstrate that Hy-MSCs possess immense potential for clinical applications via promoting stemness maintenance and enhancing immunoregulatory function.

New insights into allergic rhinitis treatment: MSC nanovesicles targeting dendritic cells

Allergic rhinitis (AR) is a condition with limited treatment options. This study investigates the potential use of mesenchymal stem cell (MSC) nanovesicles as a novel therapy for AR. Specifically, the study explores the underlying mechanisms of MSC nanovesicle therapy by targeting dendritic cells (DCs). The researchers fabricated DC-targeted P-D2-EVs nanovesicles and characterized their properties. Transcriptomic sequencing and single-cell sequencing analyses were performed to study the impact of P-D2-EVs on AR mice, identifying core genes involved in the treatment. In vitro cell experiments were conducted to validate the effects of P-D2-EVs on DC metabolism, Th2 differentiation, and ILC2 activation. The results showed that P-D2-EVs efficiently targeted DCs. Transcriptomic sequencing analysis revealed differential expression of 948 genes in nasal tissue DCs of mice treated with P-D2-EVs. Single-cell sequencing further revealed that P-D2-EVs had inhibitory effects on DC activation, Th2 differentiation, and ILC2 activation, with Fut1 identified as the core gene. Validation experiments demonstrated that P-D2-EVs improved IL10 metabolism in DCs by downregulating Fut1 expression, thereby suppressing Th2 differentiation and ILC2 activation. Animal experiments confirmed the inhibitory effects of P-D2-EVs and their ability to ameliorate AR symptoms in mice. The study suggests that P-D2-EVs reshape DC metabolism and suppress Th2 differentiation and ILC2 activation through the inhibition of the Fut1/ICAM1/P38 MAPK signaling pathway, providing a potential therapeutic approach for AR.

Functions and Clinical Applications of Extracellular Vesicles in TH2 Cell-Mediated Airway Inflammatory Diseases: A Review

Type 2 airway inflammation (T2AI), driven by type 2 innate lymphoid and CD4+ T helper 2 cells, leads to various diseases and conditions, such as chronic rhinosinusitis with nasal polyps, allergic rhinitis, and asthma. Emerging evidence suggests the involvement of extracellular vesicles (EVs) in these diseases. In this review, we describe the immunological T2AI pathogenic mechanisms, outline EV characteristics, and highlight their applications in the diagnosis and treatment of T2AI. An extensive literature search was conducted using appropriate strategies to identify relevant articles from various online databases. EVs in various biological samples showed disease-specific characteristics for chronic rhinosinusitis with nasal polyps, allergic rhinitis, and asthma, with some demonstrating therapeutic effects against these conditions. However, most studies have been limited to in vitro and animal models, highlighting the need for further clinical research on the diagnostic and therapeutic applications of EVs.

Therapeutic Efficacy of Interferon-Gamma and Hypoxia-Primed Mesenchymal Stromal Cells and Their Extracellular Vesicles: Underlying Mechanisms and Potentials in Clinical Translation

Multipotent mesenchymal stromal cells (MSCs) hold promises for cell therapy and tissue engineering due to their self-renewal and differentiation abilities, along with immunomodulatory properties and trophic factor secretion. Extracellular vesicles (EVs) from MSCs offer similar therapeutic effects. However, MSCs are heterogeneous and lead to variable outcomes. In vitro priming enhances MSC performance, improving immunomodulation, angiogenesis, proliferation, and tissue regeneration. Various stimuli, such as cytokines, growth factors, and oxygen tension, can prime MSCs. Two classical priming methods, interferon-gamma (IFN-γ) and hypoxia, enhance MSC immunomodulation, although standardized protocols are lacking. This review discusses priming protocols, highlighting the most commonly used concentrations and durations, along with mechanisms and in vivo therapeutics effects of primed MSCs and their EVs. The feasibility of up-scaling their production was also discussed. The review concluded that priming with IFN-γ or hypoxia (alone or in combination with other factors) boosted the immunomodulation capability of MSCs and their EVs, primarily via the JAK/STAT and PI3K/AKT and Leptin/JAK/STAT and TGF-β/Smad signalling pathways, respectively. Incorporating priming in MSC and EV production enables translation into cell-based or cell-free therapies for various disorders.

Mesenchymal stromal cell derived extracellular vesicles as a therapeutic tool: immune regulation, MSC priming, and applications to SLE

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by a dysfunction of the immune system. Mesenchymal stromal cell (MSCs) derived extracellular vesicles (EVs) are nanometer-sized particles carrying a diverse range of bioactive molecules, such as proteins, miRNAs, and lipids. Despite the methodological disparities, recent works on MSC-EVs have highlighted their broad immunosuppressive effect, thus driving forwards the potential of MSC-EVs in the treatment of chronic diseases. Nonetheless, their mechanism of action is still unclear, and better understanding is needed for clinical application. Therefore, we describe in this review the diverse range of bioactive molecules mediating their immunomodulatory effect, the techniques and possibilities for enhancing their immune activity, and finally the potential application to SLE.