Stromal cell-derived factor-1α promotes recruitment and differentiation of nucleus pulposus-derived stem cells

• 作者: Di-Ke Ruan Jin-Wei Ying Ling-Hao Su Shi-Shen Pei Tian-Yong Wen
• 来源期刊: 世界干细胞杂志:英文版(电子版)
• 学科: 医学
• 关键词: STROMAL cell-derived factor 1α CXC CHEMOKINE receptor 4 Nucleus pulposusderived stem cells INTERVERTEBRAL disc degeneration Endogenous regeneration
• 年，卷（期）: 2019,（3）
• 页码范围: 196-211
• 页数: 16页
• 分类号: R457

摘要

BACKGROUND Intervertebral disc (IVD) degeneration is a condition characterized by a reduction in the water and extracellular matrix content of the nucleus pulposus (NP) and is considered as one of the dominating contributing factors to low back pain. Recent evidence suggests that stromal cell-derived factor 1α(SDF-1α) and its receptor CX- C chemokine receptor type 4 (CXCR4) direct the migration of stem cells associated with injury repair in different musculoskeletal tissues. AIM To investigate the effects of SDF-1α on recruitment and chondrogenic differentiation of nucleus pulposus-derived stem cells (NPSCs). METHODS We performed real-time RT-PCR and enzyme-linked immunosorbent assay to examine the expression of SDF-1α in nucleus pulposus cells after treatment with pro-inflammatory cytokines in vitro. An animal model of IVD degeneration was established using annular fibrosus puncture in rat coccygeal discs. Tissue samples were collected from normal control and degeneration groups. Differences in the expression of SDF-1α between the normal and degenerative IVDs were analyzed by immunohistochemistry. The migration capacity of NPSCs induced by SDF-1α was evaluated using wound healing and transwell migration assays. To determine the effect of SDF-1α on chondrogenic differentiation of NPSCs, we conducted cell micromass culture and examined the expression levels of Sox-9, aggrecan, and collagen II. Moreover, the roles of SDF-1/CXCR4 axis in the migration and chondrogenesis differentiation of NPSCs were analyzed by immunofluorescence, immunoblotting, and real-time RT-PCR.RESULTS SDF-1α was significantly upregulated in the native IVD cells cultured in vitro with pro-inflammatory cytokines, such as interleukin-1β and tumor necrosis factor-α, mimicking the degenerative settings. Immunohistochemical staining showed that the level of SDF-1α was also significantly higher in the degenerative group than in the normal group. SDF-1α enhanced the migration capacity of NPSCs in a dose-dependent manner. In addition, SDF-