hLMSC Secretome Affects Macrophage Activity Differentially Depending on Lung-Mimetic Environments

Abstract

Mesenchymal stromal cell (MSC)-based therapies for inflammatory diseases rely mainly on the paracrine ability to modulate the activity of macrophages. Despite recent advances, there is scarce information regarding changes of the secretome content attributed to physiomimetic cultures and, especially, how secretome content influence on macrophage activity for therapy. hLMSCs from human donors were cultured on devices developed in house that enabled lung-mimetic strain. hLMSC secretome was analyzed for typical cytokines, chemokines and growth factors. RNA was analyzed for the gene expression of CTGF and CYR61. Human monocytes were differentiated to macrophages and assessed for their phagocytic capacity and for M1/M2 subtypes by the analysis of typical cell surface markers in the presence of hLMSC secretome. CTGF and CYR61 displayed a marked reduction when cultured in lung-derived hydrogels (L-Hydrogels). The secretome showed that lung-derived scaffolds had a distinct secretion while there was a large overlap between L-Hydrogel and the conventionally (2D) cultured samples. Additionally, secretome from L-Scaffold showed an HGF increase, while IL-6 and TNF-α decreased in lung-mimetic environments. Similarly, phagocytosis decreased in a lung-mimetic environment. L-Scaffold showed a decrease of M1 population while stretch upregulated M2b subpopulations. In summary, mechanical features of the lung ECM and stretch orchestrate anti-inflammatory and immunosuppressive outcomes of hLMSCs.

Key Role of Mesenchymal Stromal Cell Interaction with Macrophages in Promoting Repair of Lung Injury

“…Regardless of whether MSCs or their derivatives were used in the studies, their interplay with monocytes/macrophages is a key mechanism of therapeutic benefits [ 66 , 67 ]. As summarized in Table 1 , most studies found Mφ involvement in the beneficial effects of MSCs in lung injury or described a role for alveolar IL-10 increase in the effect.…”

Current possibilities and future opportunities provided by three-dimensional lung ECM-derived hydrogels

“…As soon as cells are seeded in hydrogels they begin to remodel their microenvironment (Tjin et al, 2017;Martinez-Garcia et al, 2021b;Martinez-Garcia et al, 2022). Early reports of cells in lung ECM-derived hydrogels reflect findings in single component ECM hydrogels (Tjin et al, 2017), indicating that cells remodel the ECM in which they are embedded, and the nature of the ECM that they encounter directs these remodelling events (Nizamoglu et al, 2022b;Falcones et al, 2022). This fact makes the use of lung ECMderived hydrogels sourced from diseased lungs an ideal model to understand cellular responses within such a diseased microenvironment and to provide greater knowledge of the influence of the microenvironment to treatment effects.…”

Lung Extracellular Matrix Hydrogels-Derived Vesicles Contribute to Epithelial Lung Repair

“…In particular, the physical signals exerted by the ECM composition, topography, and rigidity are translated to the cells via mechanotransduction which has been found to be crucial in regulating stem cell fate [1]. In contrast to traditional cultures, the biomechanical properties of hydrogels can be modulated to provide a physiomimetic 3D environment reproducing physiological and disease conditions in vitro [2][3][4][5]. The stemness and differentiation characteristics of mesenchymal stromal cells (MSCs) in decellularized ECM hydrogels are significant for stem cell therapy and for designing new treatments [3,4].…”

“…In contrast to traditional cultures, the biomechanical properties of hydrogels can be modulated to provide a physiomimetic 3D environment reproducing physiological and disease conditions in vitro [2][3][4][5]. The stemness and differentiation characteristics of mesenchymal stromal cells (MSCs) in decellularized ECM hydrogels are significant for stem cell therapy and for designing new treatments [3,4]. Among the different opportunities and challenges, ECM-derived hydrogels are biomechanically tunable and have been recently used as MSCs delivery systems [6] and bioinks for 3D bioprinting [5] opening new possibilities for tissue engineering.…”

“…Potential limitations are the safety of these cells, their obtention procedure, and their viability after transplantation. Interestingly, MSCs cultured on decellularized lung scaffolds [11] and native lung-derived hydrogels [3] increased their therapeutic potential compared to conventional cell cultures. In a recent study, hydrogel-encapsulated MSCs could further alleviate acute lung injury, increasing the expression of several growth factors and interleukin-10 [12].…”