Table 6.

The application of WJMSCs, IVDSCs and PSCs in vitro

Year	Team	Source of stem cells	Results
2016	Wang et al. [81]	Human WJMSCs	WJMSCs genes expression pattern is similar to ADMSCs, inflammatory stimulation can regulate genes expression
2018	Beeravolu et al. [82]	Induce human WJMSCs differentiating into CPCs	Cell structure change, glycosaminoglycan content and ECM↑
2019	Qi et al. [83]	Human WJMSCs	Activate MAPK signaling pathway, promote B-cell lymphoma-2 expression and inhibit Bax expression, ECM↑and ECM degradation ↓, COL II and proteoglycan content↑, regulate mitosis and apoptosis
2020	Zhao et al. [84]	Human WJMSCs + human NP cells	Reverse the apoptotic ratio of NP cells, block Wnt/β-catenin pathway to inhibit Wnt-related genes expression
2013	Barreto et al. [85]	Rabbit NPSCs	NPSCs migrate along the fibers and cells in IVD
2016	Wang et al. [86]	BMSCs/NPSCs/AFSCs/CESCs	CESCs are stronger in osteogenesis and chondrogenesis than the other three
2017	Huang et al. [87]	NPSCs	Hypoxia can promote NPSCs proliferation related to HIF-1α signaling pathway, Simvastatin can promote NPSCs transfer into NP cells
2018	He et al. [88]	Human CESCs	Promote CEPs repair, promote NP cells proliferation
2015	Liu et al. [89]	Human IPSCs + pig NP cell ECM	NP cells secret regulatory factors, mediate the differentiation of IPSCs into NP cells
2020	Hu et al. [90]	GDF-5 transfected human IPSCs + rat NP cells	Chondrocyte markers genes expression↑

ADMSCs adipose mesenchymal stem cells, AFSCs annulus fibrosus stem cells, BMSCs bone marrow mesenchymal stem cells, CEPs cartilaginous endplates, CESCs cartilage endplate stem cells, COL II collagen type II, CPCs chondrogenic progenitor cells, ECM extracellular matrix, GDF growth differentiation factor, HIF hypoxia inducible factor, IPSCs induced pluripotent stem cells, IVD intervertebral disc, MAPK mitogen activated protein kinase, NP nucleus pulposus, NPSCs nucleus pulposus stem cells, WJMSCs Wharton's Jelly mesenchymal stem cells