Published online Jun 21, 2021. doi: 10.3748/wjg.v27.i23.3342
Peer-review started: February 4, 2021
First decision: February 24, 2021
Revised: March 5, 2021
Accepted: May 19, 2021
Article in press: May 19, 2021
Published online: June 21, 2021
Processing time: 134 Days and 2.7 Hours
Inflammatory bowel diseases (IBD) is related to uncontrolled immune response. Currently, there is no successful treatment for significant improvement in IBD. Stem cells display their therapeutic effects through their repopulating capacity or secreting factors.
To investigate the effects of conditioned mouse adipose-derived stem cells (mADSCs) secretome on colitis-induced mice.
mADSCs were isolated from adipose tissue of C57BL/6 mice. Conditioned mADSCs secrectome was obtained by culturing of mADSCs with lipopolysaccharides (LPS, 1 μg/mL) for 24 h. Acute colitis was induced by 2% dextran sulfate sodium (DSS) drinking water for 7 d and then normal drinking water for 4 d. The mice were treated with normal culture medium (NM group), conditioned mADSCs secretome (CM group) or mADSCs (SC group). The length of colon and histopatholgy of colon tissues were evaluated. The mRNA expression levels of inflammatory cytokines in colon tissue and the serum interleukin (IL)-6 levels were determined.
The isolated mADSCs maintained the mADSCs specific gene expression profiles during experiment. The conditioned mADSCs secretome released by the treatment of mADSCs with LPS contained mainly inflammatory chemokines, colony-stimulating factors and inflammatory cytokines. The loss of body weight and reduction in colon length were ameliorated in the CM group. The conditioned mADSCs secretome reduced the histological score in colon tissue. The expression of IL-1b and IL-6 mRNAs in colon tissues significantly inhibited in the CM group compared to SC group and NM group, respectively. The elevation of serum IL-6 levels was also ameliorated in the CM group. These results indicate that the conditioned mADSCs secretome suppressed the synthesis of inflammatory cytokines in damaged colon tissue and the elevation of serum IL-6 concentration in DSS-induced mice
Conditioned mADSCs secretome might play regenerative roles by the suppression of IL-6 in serum and tissue during acute colitis, and may be more effective than stem cells themselves in the regeneration of colon tissue.
Core Tip: The therapeutic ability of mesenchymal stem cells (MSCs) is mostly mediated by their paracrine effects. Cell free therapy using MSCs secretome could be more promising strategy than stem cells based therapy. The present study demonstrates that the conditioned secretome of adipose–derived stem cells (ADSCs) has more efficient effects for improving acute colitis in dextran sulfate-sodium-induced mouse model. The effects by the conditioned secretome of ADSCs were mediated by suppression of interleukin (IL)-6 mRNA synthesis in colon tissue and serum IL-6 protein levels, which suggests that the stem cell secretome may have efficient therapeutic potential for incurable inflammatory bowel diseases.