Table 2.

The application of BMSCs in vitro

Year	Team	Source of stem cells	Results
2014	Lehmann et al. [46]	Human BMSCs + Human NP cells	BMSCs differentiate into NP cells in indirect co-culture group, and form tunneling nanotubes structure which can promote the differentiation of BMSCs in direct co-culture group
2015	Cao et al. [42]	Rabbit BMSCs + rabbit NP cells	NP cells matrix degenerate delay, TGF-β expression↑, inhibit NF-KB signaling pathway
2017	Zhou et al. [43]	Rabbit BMSCs/ADMSCs + AF cells	COL I, COL II and proteoglycan content↑ in both two group, MSCs differentiate into AF cells in both two group, BMSCs perform better than ADMSCs
2017	Lu et al. [47]	Human NP-exos + human BMSCs	BMSCs differentiate into NP cells, ECM↑
2018	Zhan et al. [37]	Rat BMSCs + Fasudil	Activate MAPK signaling pathway, promote BMSCs migration, improve the homing ability of BMSCs
2018	Cheng et al. [48]	Human BMSCs-exos + NP cells	Activate PI3K/AKT signaling pathway to inhibit NP cells apoptosis induced by TNF-α
2019	Li et al. [44]	Rat BMSCs + rat NP cells	COL II content↑, MMP9 synthesis↓, β-galactosidase expression↓, inhibiting NF-KB signaling pathway can slow the aging of NP cells
2019	Li et al. [45]	Pig BMSCs + pig NP cells ECM	BMSCs differentiate into NP cells
2019	Xia et al. [49]	Human BMSCs-exos + NP cells	Inhibit the activation of inflammatory mediators and NLRP3 inflammasome

ADMSCs adipose mesenchymal stem cells, AF annulus fibrosus, BMSCs bone marrow mesenchymal stem cells, BMSCs-exos bone marrow mesenchymal stem cells exsomes, COL I collagen type I, COL II collagen type II, ECM extracellular matrix, MAPK mitogen activated protein kinase, MMPs matrix metalloproteinases, MSCs mesenchymal stem cells, NP nucleus pulposus, NP-exos nucleus pulposus exsomes, TGF transforming growth factor, TNF tumor necrosis factor