Soluble factors secreted by human Wharton’s jelly mesenchymal stromal/stem cells exhibit therapeutic radioprotection: A mechanistic study with integrating network biology

摘要

BACKGROUND Human Wharton’s jelly-derived mesenchymal stromal/stem cells(hWJ-MSCs)have gained considerable attention in their applications in cell-based therapy due to several advantages offered by them.Recently,we reported that hWJ-MSCs and their conditioned medium have significant therapeutic radioprotective potential.This finding raised an obvious question to identify unique features of hWJ-MSCs over other sources of stem cells for a better understanding of its radioprotective mechanism.AIM To understand the radioprotective mechanism of soluble factors secreted by hWJMSCs and identification of their unique genes.METHODS Propidium iodide staining,endogenous spleen colony-forming assay,and survival study were carried out for radioprotection studies.Homeostasis-driven proliferation assay was performed for in vivo lymphocyte proliferation.Analysis of RNAseq data was performed to find the unique genes of WJ-MSCs by comparing them with bone marrow mesenchymal stem cells,embryonic stem cells,and human fibroblasts.Gene enrichment analysis and protein-protein interaction network were used for pathway analysis.RESULTS Co-culture of irradiated murine splenic lymphocytes with WJ-MSCs offered significant radioprotection to lymphocytes.WJ-MSC transplantation increased the homeostasis-driven proliferation of the lymphocytes.Neutralization of WJ-MSC conditioned medium with granulocyte-colony stimulating factor antibody abolished therapeutic radioprotection.Transcriptome analysis showed that WJ-MSCs share several common genes with bone marrow MSCs and embryonic stem cells and express high levels of unique genes such as interleukin(IL)1-α,IL1-β,IL-6,CXCL3,CXCL5,CXCL8,CXCL2,CCL2,FLT-1,and IL-33.It was also observed that WJ-MSCs preferentially modulate several cellular pathways and processes that handle the repair and regeneration of damaged tissues compared to stem cells from other sources.Cytokine-based network analysis showed that most of the radiosensitive tissues have a more complex network for the elevated cytokines.CONCLUSION Systemic infusion of WJ-MSC conditioned media will have significant potential for treating accidental radiation exposed victims。