Interleukin-1 primes human mesenchymal stem cells towards an anti-inflammatory and pro-trophic phenotype in vitro

Abstract

BackgroundInflammation is a key contributor to central nervous system (CNS) injury such as stroke, and is a major target for therapeutic intervention. Effective treatments for CNS injuries are limited and applicable to only a minority of patients. Stem cell-based therapies are increasingly considered for the treatment of CNS disease, because they can be used as in-situ regulators of inflammation, and improve tissue repair and recovery. One promising option is the use of bone marrow-derived mesenchymal stem cells (MSCs), which can secrete anti-inflammatory and trophic factors, can migrate towards inflamed and injured sites or can be implanted locally. Here we tested the hypothesis that pre-treatment with inflammatory cytokines can prime MSCs towards an anti-inflammatory and pro-trophic phenotype in vitro.MethodsHuman MSCs from three different donors were cultured in vitro and treated with inflammatory mediators as follows: interleukin (IL)-1α, IL-1β, tumour necrosis factor alpha (TNF-α) or interferon-γ. After 24 h of treatment, cell supernatants were analysed by ELISA for expression of granulocyte-colony stimulating factor (G-CSF), IL-10, brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), IL-1 receptor antagonist (IL-1Ra) and vascular endothelial growth factor (VEGF). To confirm the anti-inflammatory potential of MSCs, immortalised mouse microglial BV2 cells were treated with bacterial lipopolysaccharide (LPS) and exposed to conditioned media (CM) of naïve or IL-1-primed MSCs, and levels of secreted microglial-derived inflammatory mediators including TNF-α, IL-10, G-CSF and IL-6 were measured by ELISA.ResultsUnstimulated MSCs constitutively expressed anti-inflammatory cytokines and trophic factors (IL-10, VEGF, BDNF, G-CSF, NGF and IL-1Ra). MSCs primed with IL-1α or IL-1β showed increased secretion of G-CSF, which was blocked by IL-1Ra. Furthermore, LPS-treated BV2 cells secreted less inflammatory and apoptotic markers, and showed increased secretion of the anti-inflammatory IL-10 in response to treatment with CM of IL-1-primed MSCs compared with CM of unprimed MSCs.ConclusionsOur results demonstrate that priming MSCs with IL-1 increases expression of trophic factor G-CSF through an IL-1 receptor type 1 (IL-1R1) mechanism, and induces a reduction in the secretion of inflammatory mediators in LPS-activated microglial cells. The results therefore support the potential use of preconditioning treatments of stem cells in future therapies.Electronic supplementary materialThe online version of this article (doi:10.1186/s13287-017-0531-4) contains supplementary material, which is available to authorized users.

Neuro‐Cells therapy improves motor outcomes and suppresses inflammation during experimental syndrome of amyotrophic lateral sclerosis in mice

“…These processes are likely to act on RNA‐dependent and RNA‐independent elements of FUS‐related pathology . Transplanted bone marrow derived stem cells were shown to secrete such anti‐inflammatory cytokines and growth factors, as IL‐10, vascular endothelial growth factor (VEGF), insulin‐like growth factor‐1 (IGF‐1), hepatocyte growth factor (HGF), brain‐derived neurotrophic factor (BDNF), neuronal growth factor (NGF), and others . This secretion was shown to be condition‐dependent, and in particular, the presence of inflammation was found to stimulate the release of the anti‐inflammatory molecules .…”

“…Transplanted bone marrow derived stem cells were shown to secrete such anti‐inflammatory cytokines and growth factors, as IL‐10, vascular endothelial growth factor (VEGF), insulin‐like growth factor‐1 (IGF‐1), hepatocyte growth factor (HGF), brain‐derived neurotrophic factor (BDNF), neuronal growth factor (NGF), and others . This secretion was shown to be condition‐dependent, and in particular, the presence of inflammation was found to stimulate the release of the anti‐inflammatory molecules . Given that FUS protein is considered to be functionally related with insulin/IGF‐signaling pathway, an important element of which is BDNF, a ligand of TrkB receptor, which regulates the mechanisms of cellular stress, it can be suggested that paracrine secretion of Neuro‐Cells cytokines and growth factors may underlie the anti‐inflammatory and antidegenerative changes observed in the FUS‐tg mice.…”

Pro-Inflammatory Priming of Umbilical Cord Mesenchymal Stromal Cells Alters the Protein Cargo of Their Extracellular Vesicles

“…In one experimental setting, UCMSCs were stimulated with pro-inflammatory cytokines (hereafter referred to as 'primed') for 48 h when they reached 80% confluence. They were treated with an inflammatory cocktail containing 5 ng/mL TNF-α, 2.5n g/mL IFN-γ and 2.5 ng/mL IL-1β (Peprotech, London, UK) [11,14,15]. Figure 1 outlines the experimental plan and culture conditions of UCMSCs.…”

Advancing cell therapies for intervertebral disc regeneration from the lab to the clinic: Recommendations of the ORS spine section

“…Given the varying stages of degeneration and microenvironments that exist in vivo, it will be important to tailor or design treatments for individuals. One way to achieve this could be to condition stem cells prior to implantation by acclimatizing them to patient specific in vivo microenvironmental milieu, which may include inflammatory cytokines, acidity, oxygen or nutrient deprivation . These treatments must be assessed using appropriate in vitro and ex vivo culture conditions which mimic those of the degenerate niche to assess the likely behavior and survival of transplanted cells prior to progressing to in vivo testing …”