Mesenchymal stem cell-derived microRNAs: Key immunomodulators to prevent ocular tissue degeneration

Table 1 Effects of mesenchymal stem cell-derived microRNAs in corneal diseases

Type of MSC	MiRNA	Target	Expression pattern	Function	Ref.
Human umbilical cord-MSC	MiR-21	PTEN	Upregulated	Enhanced corneal epithelial cell proliferation, migration, and wound healing, both in vitro and in vivo	Liu et al[53]
Human limbal MSC	MiR-155, miR-29	TGF-β1/β3	Upregulated	Negatively regulated corneal fibrosis by inhibiting collagen matrix synthesis instead of inhibiting myofibroblast formation	Altug et al[58]
Mouse bone marrow-MSC	MiR-29b-3p	PI3K	Upregulated	Improved the therapeutic effect via activated autophagy and inhibited corneal inflammation and fibrosis	Liu et al[59]
Rabbit adipose derived MSC	MiR-19	HIPK2	Upregulated	Suppressed fetal bovine serum induced differentiation of rabbit corneal keratocytes into myofibroblasts by inhibiting HIPK2 expression	Shen et al[57]
Rabbit adipose-derived MSC	MiR-24-3p	-	Upregulated	Enhanced healing of corneal epithelial defect, cell migration, and maturation while inhibiting fibrosis and reducing the levels of inflammatory cytokines (CD163, and MMP9) in both in vitro and in vivo	Sun et al[56]
Human adipose-derived MSC	Let-7a-5p, miR-23a-3p, miR-29b-3p, miR-302-3p, and miR-1246	-	Upregulated	Improved the wound healing and migration of corneal epithelial cells by inducing a shift in the cell cycle, and inhibiting senescence and autophagy pathways	Ryu et al[55]

HIPK2: Homeodomain-interacting protein kinase 2; miRNA: MicroRNA; MMP9: Matrix metalloproteinase-9; MSC: Mesenchymal stem cell; PI3K: Phosphatidylinositol 3-kinase; PTEN: Phosphatase and tensin homolog; TGF-1: Transforming growth factor beta 1.