EFFECTS OF HUMAN URINE-DERIVED STEM CELL EXOSOMES ON THE PROLIFERATION AND DIFFERENTIATION OF NUCLEUS PULPOSUS-LIKE URINE-DERIVED STEM CELLS

Objective To explore the relationship between degree of differentiation and time of differentiation of nucleus pulposus-like urine-derived stem cells (NP-USC) and the effects of human urine-derived stem cell exosomes (USC-EXO) on the proliferation and differentiation of NP-USC. Methods Nucleus pulposus cells (NPC) and urine-derived stem cells (USC) were extracted, identified, and cultured. According to the co-cultivation time, the cells were divided into group A (after 7 d of co-culture, the NP-USC were cultured in exosome-free USC medium for 14 d), group B (after 14 d of co-culture, the NP-USC were cultured in exosome-free USC medium for 7 d), group C (USC were cultured alone for 21 d), and NPC group (NPC were cultured alone for 21 d). Quantitative real-time PCR (RT-qPCR) and Western blot were used to measure the mRNA and protein expression of hypoxia-inducible factor 1α (HIF-1α), glucose transporter 1 (GLUT1), type Ⅱ collagen (COL2), and proteoglycan (ACAN) in the five groups. The cells in the five groups w