Mesenchymal stem cell and endothelial progenitor cells coinjection improves LPS-induced lung injury via Tie2 activation and downregulation of the TLR4/MyD88 pathway

TREATMENT WITH HUMAN UMBILICAL CORD-DERIVED MESENCHYMAL STEM CELLS IN A PIG MODEL OF SEPSIS-INDUCED ACUTE KIDNEY INJURY: EFFECTS ON MICROVASCULAR ENDOTHELIAL CELLS AND TUBULAR CELLS IN THE KIDNEY

ABSTRACT

Background: Approximately 50% of patients with sepsis develop acute kidney injury (AKI), which is predictive of poor outcomes, with mortality rates of up to 70%. The endothelium is a major target for treatments aimed at preventing the complications of sepsis. We hypothesized that human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) could attenuate tubular and endothelial injury in a porcine model of sepsis-induced AKI. Methods: Anesthetized pigs were induced to fecal peritonitis, resulting in septic shock, and were randomized to treatment with fluids, vasopressors, and antibiotics (sepsis group; n = 11) or to that same treatment plus infusion of 1 × 10 6 cells/kg of hUC-MSCs (sepsis+MSC group; n = 11). Results: At 24 h after sepsis induction, changes in serum creatinine and mean arterial pressure were comparable between the two groups, as was mortality. However, the sepsis+MSC group showed some significant differences in comparison with the sepsis group: lower fractional excretions of sodium and potassium; greater epithelial sodium channel protein expression; and lower protein expression of the Na-K-2Cl cotransporter and aquaporin 2 in the renal medulla. Expression of P-selectin, thrombomodulin, and vascular endothelial growth factor was significantly lower in the sepsis+MSC group than in the sepsis group, whereas that of Toll-like receptor 4 (TLR4) and nuclear factor-kappa B (NF-κB) was lower in the former. Conclusion: Treatment with hUC-MSCs seems to protect endothelial and tubular cells in sepsis-induced AKI, possibly via the TLR4/NF-κB signaling pathway. Therefore, it might be an effective treatment for sepsis-induced AKI.

Mesenchymal Stem Cells-derived Exosomes Ameliorate Lupus by Inducing M2 Macrophage Polarization and Regulatory T Cell Expansion in MRL/lpr Mice

Previous studies have implicated that the transplantation of human umbilical cord mesenchymal stem cells (hUC-MSCs) effectively alleviates systemic lupus erythematosus (SLE) primarily due to immunomodulatory effects. However, little is known about the role of hUC-MSC-derived exosomes in SLE. This study is carried out to investigate the modifying effects of hUC-MSC-exosomes on the differentiation and function of immune cells in SLE. hUC-MSC-derived exosomes were extracted from the cultural supernatant of hUC-MSCs by ultrahigh speed centrifugation. Quantitative real-time polymerase chain reaction, western blot, enzyme-linked immunosorbent assay, and flow cytometry were performed to estimate the effect of hUC-MSC-derived exosomes on macrophage and regulatory T cell (Treg) polarization. In vivo, hUC-MSC-exosomes were injected intravenously into 28-week-old MRL/lpr mice. We had found that exosomes derived from hUC-MSC restrained the proliferation and inflammation of macrophages in vitro. Besides, MSC-exosomes inhibited CD68⁺M1 and HLA-DR⁺M1 but promoted CD206⁺M2 and CD163⁺M2 in vitro. Moreover, MRL/lpr mice administrated by intravenous injection of MSC-exosomes had less infiltration of CD14⁺CD11c⁺M1 cells but more CD14⁺CD163⁺M2 cells as well as Tregs in spleens compared with those in MRL/lpr mice treated by PBS. Additionally, MSC-exosomes could alleviate nephritis, liver and lung injuries of MRL/lpr mice. The survival of lupus mice could be improved after MSC-exosome treatment. This study has suggested that MSC-derived exosomes exert anti-inflammatory and immunomodulatory effects in SLE. MSC-exosomes ameliorate nephritis and other key organ injuries by inducing M2 macrophages and Tregs polarization. As natural nanocarriers, MSC-exosomes may serve as a promising cell-free therapeutic strategy for SLE.Abbreviations: SLE: Systemic lupus erythematosus; hUC-MSCs: Human umbilical cord mesenchymal stem cells; MSCs: Mesenchymal stem cells; qRT-PCR: Quantitative real-time polymerase chain reaction; ELISA: Enzyme-linked immunosorbent assay; Tregs: Regulatory cells; TNF-α: Tumor necrosis factor alfa; IL: Interleukin; COVID-19: Coronavirus disease 2019; pTHP-1: PMA-induced THP-1 macrophages; TEM: Transmission electron microscopy; LPS: Lipopolysaccharide; EVs: Extracellular vesicles; TRAF1: Tumor necrosis factor receptor-associated factor 1; IRAK1: Interferon-α-interleukin-1 receptor-associated kinase 1; NF-κB: Nuclear factor-κB; BLyS: B lymphocyte stimulator; APRIL: A proliferation-inducing ligand.

Proteomic and phosphorylated proteomic landscape of injured lung in juvenile septic rats with therapeutic application of umbilical cord mesenchymal stem cells

Acute lung injury (ALI) is the most common complication of sepsis. Intravenous injection of HUMSCs can regulate the level of circulating endothelial cytokines and alleviate lung injury in juvenile septic rats. In this study, we performed proteomic and phosphorylated proteomic analysis of lung tissue of juvenile septic rats after Human Umbilical Cord Mesenchymal Stem Cells (HUMSCs) intervention for the first time, and screened the potential proteins and pathways of HUMSCs for therapeutic effect. The 4D proteome quantitative technique was used to quantitatively analyze the lung tissues of septic rats 24 hours (3 biological samples) and 24 hours after HUMSCs intervention (3 biological samples). A total of 213 proteins were identified as differentially expressed proteins, and 971 phosphorylation sites changed significantly. Based on the public database, we analyzed the functional enrichment of these proteins and phosphorylated proteins. In addition, Tenascin-C may be the key differential protein and ECM receptor interaction pathway may be the main signal pathway by using various algorithms to analyze the protein-protein interaction network. Phosphorylation analysis showed that tight junction pathway was closely related to immune inflammatory reaction, and EGFR interacted most, which may be the key differential phosphorylated protein. Finally, 123 conserved motifs of serine phosphorylation site (pS) and 17 conserved motifs of threonine (pT) phosphorylation sites were identified by motif analysis of phosphorylation sites. Results from proteomics and phosphorylated proteomics, the potential new therapeutic targets of HUMSCs in alleviating lung injury in juvenile septic rats were revealed.