Table 2.

miRNA dysregulated in serum of osteoporotic patients and their function.

miRNA	Expression in OP patients	Biological function	Target	Ref.
Let-7g-5p	Downregulated	Promotes osteogenesis and ectopic bone formation and suppresses adipogenesis	HMGA2	[69]
miR-10b-5p	Upregulated	Potent inhibitor of OB differentiation	Bcl6	[80]
miR-19a miR-19b	Downregulated	Part of a cluster of miRNAs that probably maintains OB in undcifferentiated state	Undetected	[64]
miR-21	Upregulated	Promotes OB differentiation and mineralization	Smad7	[43]
		Essential for OC formation and OC bone-resorbing activity, preserves OCs from apoptosis	FasL, PDCD4	[41, 42]
miR-22-3p	Downregulated	Important regulator of the balance between adipogenic and osteogenic differentiation. Promoter of OB differentiation	HDAC6	[68]
miR-23a	Upregulated	Potent inhibitor of OB apoptosis and promoter of osteogenic differentiation	Fas, Runx2	[70, 71]
miR-24	Upregulated	Inhibits OB differentiation and mineralization	Tcf-1	[81]
miR-27	Downregulated	Promotes OB differentiation by inhibition of the suppressor of β-catenin	APC	[56]
miR-29a-3p	Downregulated	Promotes OB differentiation by repressing endogenous levels of Wnt signaling antagonists	DKK1, Kremen2, sFRP2	[82]
miR-30 family	Downregulated	Downregulated during OB differentiation are considered negative regulators of osteogenesis. One component of this family promotes adipogenesis rather than OB genesis	Smad1, Runx2, LRP6	[59]
miR-100	Upregulated	Negative regulator of OB differentiation	BMPR2	[83]
miR-124	Upregulated	Enhances the adipogenic differentiation of BMSCs and inhibits osteogenesis. It is a suppressor of bone formation	Dlx5, Dlx3, Dlx2	[73]
		Negative regulator of RANKL-dependent OC genesis. It inhibits the migration of OC precursors	NFATc1, RhoA, Rac1	[73]
miR-125	Upregulated	Negative regulator of OB precursor proliferation and OB differentiation in the early stages	ErbB2	[63]
miR-140-5p	Downregulated	Downregulated during osteogenesis. It is a suppressor of OB differentiation	BMP2	[65]
miR-142	Downregulated	Positively regulates OB precursor differentiation by activating Wnt signaling	APC	[60]
miR-148a	Upregulated	Negative regulator of adipogenesis and promoter of OB differentiation	Kdm6b	[46]
		Promotes OC genesis and increased the bone resorption area on dentin slices	MAFB	[45]
miR-2861	Upregulated	Promoter of OB differentiation	HDAC5	[75]