Table 2.

Experimentally verified miRNAs associated with IDD

MiRNA	Expression	Target(s)	Functions	Publication year	References
MiR-155	↓	FADD, caspase-3 ERK1/2, TCF7L2, MMP-16	↓NP cell apoptosis ↓ECM degradation	2011 2016–2018	[18] [33–35]
MiR-21	↓* ↑	PTEN PTEN, PDCD4 PTEN	↓NP cell apoptosis ↑NP cell proliferation ↑ECM degradation	2018 2014,2016 2018	[36] [21, 37] [38]
MiR-27a	↑	PI3K	↑NP cell apoptosis	2013	[39]
MiR-499a-5p	↓	SOX4	↓NP cell apoptosis ↓ECM degradation	2019 2019	[40] [40]
MiR-494	↑	SOX9, JunD SOX9	↑NP cell apoptosis ↑ECM degradation	2015,2017 2017	[41, 42] [41]
MiR-30d	↑	SOX9	↑NP cell apoptosis ↑ECM degradation	2018 2018	[43] [43]
MiR-222-3p	↑	CDKN1B	↑NP cell apoptosis ↓NP cell proliferation ↑ECM degradation	2019 2019 2019	[44] [44] [44]
MiR-15a	↑	MAP3K9	↑NP cell apoptosis ↓NP cell proliferation	2017 2017	[45] [45]
MiR-486-5p	↓	FOXO1	↓NP cell apoptosis ↓ECM degradation ↓inflammation	2019 2019 2019	[46] [46] [46]
MiR-200c	↑	XIAP	↑NP cell apoptosis ↑ECM degradation	2018 2018	[23] [23]
MiR-328-5p	↑	ERBB2	↑NP cell apoptosis	2018	[47]
MiR-34a	↑	GDF5 Bcl-2	↑ECM degradation ↑CEP cell apoptosis	2016 2015	[48] [7]
MiR-143	↑	Bcl-2	↑NP cell apoptosis	2017	[49]
MiR-532	↑	Bcl-9	↑NP cell apoptosis	2018	[50]
MiR-125a	↓	TP53INP1	↓NP cell apoptosis	2016	[51]
MiR-221	↑	ERα FOXO3, TRPS1 BMP-Smad pathway	↑CEP cell apoptosis ↑ECM degradation ↑inflammation ↓chondrogenesis ↓AF cell osteogenic differentiation	2018 2018 2018 2018 2016	[52] [52] [52] [53] [54]
MiR-138-5p	↑	SIRT1	↑NP cell apoptosis	2016	[55]
MiR-145	↓	ADAM17	↓NP cell apoptosis ↓ECM degradation	2019 2019	[56] [56]
MiR-573	↓	Bax	↓NP cell apoptosis	2019	[57]
MiR-153-3p	↓	ATG5	↓NP cell autophagy	2019	[58]
MiR-106a-5p	↑	ATG7	↑AF cell apoptosis ↓AF cell proliferation	2019 2019	[8] [8]
MiR-10b	↑	HOXD10	↑NP cell proliferation	2013	[59]
MiR-96	↑	ARID2	↑NP cell proliferation	2017	[60]
MiR-184	↑	GAS1	↑NP cell proliferation	2017	[61]
MiR-2355-5p	↑	ERFFI1	↑NP cell proliferation ↑inflammation	2019 2019	[62] [62]
MiR-365	↓	HDAC4	↑CEP cell proliferation	2019	[63]
MiR-125b-1-3p	↑	TSHZ3	↓NP cell proliferation	2018	[64]
MiR-665	↑	GDF5	↑NP cell proliferation ↑ECM degradation	2018 2018	[65] [65]
MiR-7	↑	GDF5	↑ECM degradation	2016	[66]
MiR-132	↑	GDF5	↑ECM degradation	2017	[67]
MiR-15b	↑	SMAD3	↑ECM degradation	2017	[68]
MiR-20a	↑	ANKH	↑CEP chondrocyte calcification	2016	[69]
MiR-377	↑	ADAMTS5	↑ECM degradation	2013	[70]
MiR-202-3p	↓	MMP1	↓ECM degradation	2019	[71]
MiR-17-3p	↓	MMP2	↓ECM degradation ↓NP cell apoptosis ↑NP cell proliferation	2018 2018 2018	[72] [72] [72]
MiR-93	↓	MMP3	↓ECM degradation	2015	[73]
MiR-133a	↓	MMP9	↓ECM degradation	2016	[74]
MiR-27b	↓	MMP13	↓ECM degradation	2016	[75]
MiR-127-5p	↓	MMP13	↓ECM degradation	2017	[76]
MiR-193a-3p	↓	MMP14	↓ECM degradation	2016	[77]
MiR-98	↓	IL-6	↓ECM degradation	2016	[78]
MiR-100	↑	FGFR3	↑ECM degradation	2015	[79]
MiR-146a	Not clear**	TRAF6	↑ECM degradation ↓inflammation	2015 2015,2017	[22] [22, 80]
MiR-210	↑	ATG7	↑ECM degradation	2017	[81]
MiR-194	↑	CHSY1/2/3	↑ECM degradation	2017	[82]
MiR-515	↑	CHSY1/2/3	↑ECM degradation	2017	[82]
MiR-3150a-3p	↑	ACAN	↑ECM degradation	2018	[83]
MiR-640	↑	LRP1,β-catenin, EP300	↑inflammation	2019	[84]
MiR-140-5p	↓	TLR4	↓inflammation	2018	[85]

The expression, targets, and functions of miRNAs related to IDD were displayed in Table 2. “↓” represents downregulation, while “↑” represents upregulation

*Decrease in apoptotic NP cells.**It is reported that miR-146a is significantly downregulated in the PBMCs of IDD patients, but its expression in NP cells is unclear [80]