Exosomes derived from TREM-2 knocked-out macrophages alleviated renal fibrosis via HSPa1b/AKT pathway

ABSTRACT: Macrophages are recognized as the vital players in renal fibrosis, with a high degree of heterogeneity and plasticity, and triggering receptor expressed on myeloid cell-2(TREM-2) was highly expressed on macrophages and participated in the progression of tissue fibrosis. However, the mechanism by which TREM-2 mediate the progress of renal fibrosis is still unclear. Our study have found the exosomes derived from TREM-2 deficient (TREM-2-/-) macrophages could suppress the progression of fibrosis, showing a higher matrix metalloproteinase-9 (MMP-9) / tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) ration at protein level in secreted exosomes than exosomes from WT（wild type）macrophages in the fibrotic microenvironment. Besides, renal tubular epithelial cells (TECs) engulfed theses nanoscale vesicles, the expression of collagen I and α-smooth muscle actin (α-SMA) (fibrosis related marker) was obviously decreased. Through the RNA-seq, we found that TREM-2-/- macrophages upregulate the MMP-9/TIMP-1 ratio in its exosomes via HSPa1b/AKT pathway. Furthermore, it’s noteworthy that the renal fibrosis was effectively alleviated in the obstructed kidney from mice received a renal pelvis injection of adeno associated virus (AAV-shTREM-2) containing the sequence of silencing TREM-2. However, VER-155008 (inhibitor of HSPa1b) and Ly294002 (inhibitor of AKT) reversed this effect. Moreover, polyclonal antibodies against TREM-2 also effectively relieved the UUO-induced renal fibrosis. Above all, we have validated that the knocking down TREM-2 expression can inhibit the progression of renal fibrosis through a macrophage exosome-dependent pathway in vitro and vivo. Hence, our finding suggest TREM-2 is potential therapeutic target for CKD.

ORGANISM(S): Mus musculus

PROVIDER: GSE262665 | GEO | 2024/11/29

REPOSITORIES: GEO