Background and Objectives: Human mesenchymal stem cells (MSCs) are emerging as a treatment for atopic dermatitis (AD), a chronic inflammatory skin disorder that affects a large number of people across the world. Treatment of AD using human umbilical cord blood-derived MSCs (hUCB-MSCs) has recently been studied. However, the mechanism underlying their effect needs to be studied continuously. Thus, the objective of this study was to investigate the immunomodulatory effect of epidermal growth factor (EGF) secreted by hUCB-MSCs on AD. Methods: and Results: To explore the mechanism involved in the therapeutic effect of MSCs for AD, a secretome array was performed using culture medium of hUCB-MSCs. Among the list of genes common for epithelium development and skin diseases, we focused on the function of EGF. To elucidate the effect of EGF secreted by hUCB-MSCs, EGF was downregulated in hUCB-MSCs using EGF-targeting small interfering RNA. These cells were then co-cultured with keratinocytes, Th2 cells, and mast cells. Depletion of EGF disrupted immunomodulatory effects of hUCB-MSCs on these AD-related inflammatory cells. In a Dermatophagoides farinae-induced AD mouse model, subcutaneous injection of hUCB-MSCs ameliorated gross scoring, histopathologic damage, and mast cell infiltration. It also significantly reduced levels of inflammatory cytokines including interleukin (IL)-4, tumor necrosis factor (TNF)-α, thymus and activation-regulated chemokine (TARC), and IL-22, as well as IgE levels. These therapeutic effects were significantly attenuated at all evaluation points in mice injected with EGF-depleted hUCB-MSCs. Conclusions EGF secreted by hUCB-MSCs can improve AD by regulating inflammatory responses of keratinocytes, Th2 cells, and mast cells.

Acute Respiratory Distress Syndrome (ARDS) is a severe condition characterized by extensive lung inflammation and increased alveolar-capillary permeability, often triggered by infections or systemic inflammatory responses. Mesenchymal stem cells (MSCs)-based therapy holds promise for treating ARDS, as MSCs manifest immunomodulatory and regenerative properties that mitigate inflammation and enhance tissue repair. Primed MSCs, modified to augment specific functionalities, demonstrate superior therapeutic efficacy in targeted therapies compared to naive MSCs. This study explored the immunomodulatory potential of MSCs using mixed lymphocyte reaction (MLR) assays and co-culture experiments with M1/M2 macrophages. Additionally, RNA sequencing was employed to identify alterations in immune and inflammation-related factors in primed MSCs. The therapeutic effects of primed MSCs were assessed in an LPS-induced ARDS mouse model, and the underlying mechanisms were investigated through spatial transcriptomics analysis. The study revealed that MSCs primed with IFN-γ and IL-1β significantly enhanced the suppression of T cell activity compared to naive MSCs, concurrently inhibiting TNF-α while increasing IL-10 production in macrophages. Notably, combined treatment with these two cytokines resulted in a significant upregulation of immune and inflammation-regulating factors. Furthermore, our analyses elucidated the mechanisms behind the therapeutic effects of primed MSCs, including the inhibition of inflammatory cell infiltration in lung tissue, modulation of immune and inflammatory responses, and enhancement of elastin fiber formation. Signaling pathway analysis confirmed that efficacy could be enhanced by modulating NFκB and TNF-α signaling. In conclusion, in early-phase ARDS, primed MSCs displayed enhanced homing capabilities, improved lung function, and reduced inflammation.

Acute Respiratory Distress Syndrome (ARDS) is a severe condition characterized by extensive lung inflammation and increased alveolar-capillary permeability, often triggered by infections or systemic inflammatory responses. Mesenchymal stem cells (MSCs)-based therapy holds promise for treating ARDS, as MSCs manifest immunomodulatory and regenerative properties that mitigate inflammation and enhance tissue repair. Primed MSCs, modified to augment specific functionalities, demonstrate superior therapeutic efficacy in targeted therapies compared to naive MSCs. This study explored the immunomodulatory potential of MSCs using mixed lymphocyte reaction (MLR) assays and co-culture experiments with M1/M2 macrophages. Additionally, RNA sequencing was employed to identify alterations in immune and inflammation-related factors in primed MSCs. The therapeutic effects of primed MSCs were assessed in an LPS-induced ARDS mouse model, and the underlying mechanisms were investigated through spatial transcriptomics analysis. The study revealed that MSCs primed with IFN-γ and IL-1β significantly enhanced the suppression of T cell activity compared to naive MSCs, concurrently inhibiting TNF-α while increasing IL-10 production in macrophages. Notably, combined treatment with these two cytokines resulted in a significant upregulation of immune and inflammation-regulating factors. Furthermore, our analyses elucidated the mechanisms behind the therapeutic effects of primed MSCs, including the inhibition of inflammatory cell infiltration in lung tissue, modulation of immune and inflammatory responses, and enhancement of elastin fiber formation. Signaling pathway analysis confirmed that efficacy could be enhanced by modulating NFκB and TNF-α signaling. In conclusion, in early-phase ARDS, primed MSCs displayed enhanced homing capabilities, improved lung function, and reduced inflammation.

Acute Respiratory Distress Syndrome (ARDS) is a severe condition characterized by extensive lung inflammation and increased alveolar-capillary permeability, often triggered by infections or systemic inflammatory responses. Mesenchymal stem cells (MSCs)-based therapy holds promise for treating ARDS, as MSCs manifest immunomodulatory and regenerative properties that mitigate inflammation and enhance tissue repair. Primed MSCs, modified to augment specific functionalities, demonstrate superior therapeutic efficacy in targeted therapies compared to naive MSCs. This study explored the immunomodulatory potential of MSCs using mixed lymphocyte reaction (MLR) assays and co-culture experiments with M1/M2 macrophages. Additionally, RNA sequencing was employed to identify alterations in immune and inflammation-related factors in primed MSCs. The therapeutic effects of primed MSCs were assessed in an LPS-induced ARDS mouse model, and the underlying mechanisms were investigated through spatial transcriptomics analysis. The study revealed that MSCs primed with IFN-γ and IL-1β significantly enhanced the suppression of T cell activity compared to naive MSCs, concurrently inhibiting TNF-α while increasing IL-10 production in macrophages. Notably, combined treatment with these two cytokines resulted in a significant upregulation of immune and inflammation-regulating factors. Furthermore, our analyses elucidated the mechanisms behind the therapeutic effects of primed MSCs, including the inhibition of inflammatory cell infiltration in lung tissue, modulation of immune and inflammatory responses, and enhancement of elastin fiber formation. Signaling pathway analysis confirmed that efficacy could be enhanced by modulating NFκB and TNF-α signaling. In conclusion, in early-phase ARDS, primed MSCs displayed enhanced homing capabilities, improved lung function, and reduced inflammation.