Extracellular membrane vesicles from umbilical cord blood‐derived MSC protect against ischemic acute kidney injury, a feature that is lost after inflammatory conditioning

Abstract

BackgroundMesenchymal stromal cells (MSC) are shown to have a great therapeutic potential in many immunological disorders. Currently the therapeutic effect of MSCs is considered to be mediated via paracrine interactions with immune cells. Umbilical cord blood is an attractive but still less studied source of MSCs. We investigated the production of extracellular membrane vesicles (MVs) from human umbilical cord blood derived MSCs (hUCBMSC) in the presence (MVstim) or absence (MVctrl) of inflammatory stimulus.MethodshUCBMSCs were cultured in serum free media with or without IFN-γ and MVs were collected from conditioned media by ultracentrifugation. The protein content of MVs were analyzed by mass spectrometry. Hypoxia induced acute kidney injury rat model was used to analyze the in vivo therapeutic potential of MVs and T-cell proliferation and induction of regulatory T cells were analyzed by co-culture assays.ResultsBoth MVstim and MVctrl showed similar T-cell modulation activity in vitro, but only MVctrls were able to protect rat kidneys from reperfusion injury in vivo. To clarify this difference in functionality we made a comparative mass spectrometric analysis of the MV protein contents. The IFN-γ stimulation induced dramatic changes in the protein content of the MVs. Complement factors (C3, C4A, C5) and lipid binding proteins (i.e apolipoproteins) were only found in the MVctrls, whereas the MVstim contained tetraspanins (CD9, CD63, CD81) and more complete proteasome complex accompanied with MHCI. We further discovered that differently produced MV pools contained specific Rab proteins suggesting that same cells, depending on external signals, produce vesicles originating from different intracellular locations.ConclusionsWe demonstrate by both in vitro and in vivo models accompanied with a detailed analysis of molecular characteristics that inflammatory conditioning of MSCs influence on the protein content and functional properties of MVs revealing the complexity of the MSC paracrine regulation.

Nanosized UCMSC-derived extracellular vesicles but not conditioned medium exclusively inhibit the inflammatory response of stimulated T cells: implications for nanomedicine

“…Expression of HLA-II molecules in MSCs would trigger the activation of the host's innate immune system which in turn would impede their potential immunomodulatory effect. In fact, it has been suggested that the increased HLA expression in EVs from umbilical cord blood-derived MSCs after treatment with IFNγ may be responsible of the loss of their protective effect against ischemic acute kidney injury 31. Given that our results suggest that non-primed UCMSCs are as potent as primed MSCs in regulating T cell responses, we would consider using non-primed cells in therapeutic approaches.…”

“…MSCs have been described to suppress the immune response affecting T cell proliferation and polarization, to induce regulatory T cells, and to module Antigen Presenting Cells (APCs) 11,31-34. In our settings, UCMSCs were confirmed to have potent suppressive capabilities on T cell proliferation, but whereas IFNγ conditioning enhances immunosuppressive functions of both bone marrow- and adipose tissue-derived MSCs 7,9,35, no differences were found comparing IFNγ-primed to non-primed UCMSCs.…”

Mesenchymal stem cell derived secretome and extracellular vesicles for acute lung injury and other inflammatory lung diseases

“…MSC-derived EV biogenesis has been shown to be regulated by cross-talk between MSC and their surrounding microenvironment. Thus, extracellular conditions, such as hypoxia or inflammation, influence molecular packaging into EVs, and impact their functional properties[54, 55]. Both exosomes and microvesicles interact with their target cells via either ligand-receptor signaling pathways or internalization by phagocytosis, endocytosis, and direct membrane fusion (Figure 2).…”

“…Overall, MVs were found to mimic the beneficial effects of MSCs, modulating T-cells as well as innate immune cell functions[54]. The effects appeared to be mediated in part by the transfer of RNA by MSC MVs to the injured renal epithelium, as indicated by the loss of reparative effects after RNase pretreatment of the MVs[40, 69, 72].…”

Rationale of Mesenchymal Stem Cell Therapy in Kidney Injury

“…Another interesting finding is that MSC-MV change their content depending on the environment in which they are cultured; Kilpinen et al [12] compared MSC-conditioned media in the presence or absence of interferon-γ mimicking an inflammatory microenvironment. They compared the ability of MSC to protect rats from reperfusion injury in vivo; while the MSC cultured under normal conditions had a protective effect on kidney function, this effect was abrogated when the cells were cultured in the presence of interferon-γ.…”