Transplantation of Hypoxic-Preconditioned Bone Mesenchymal Stem Cells Retards Intervertebral Disc Degeneration via Enhancing Implanted Cell Survival and Migration in Rats

Abstract

Objective Special hypoxic and hypertonic microenvironment in intervertebral discs (IVDs) decreases the treatment effect of cell transplantation. We investigated the hypothesis that hypoxic preconditioning (HP) could improve the therapeutic effect of bone mesenchymal stem cells (BMSCs) to IVD degeneration. Methods BMSCs from green fluorescent protein-transgenic rats were pretreated with cobalt chloride (CoCl2, 100 μM, 24 h) for hypoxic conditions in vitro. Apoptosis (related pathways of caspase-3 and bcl-2) and migration (related pathways of HIF-1α and CXCR4) were detected in BMSCs. In vivo, BMSCs and HP BMSCs (H-BMSCs) were injected into the rat model of IVD degeneration. The IVD height, survival, migration, and differentiation of transplanted BMSCs and matrix protein expression (collagen II, aggrecan, and MMP-13) were tested. Results H-BMSCs could extensively decrease IVD degeneration by increasing IVD height and collagen II and aggrecan expressions when compared with BMSCs. Significantly, more GFP-positive BMSCs were observed in the nucleus pulposus and annulus fibrosus regions of IVD. HP could significantly decrease BMSC apoptosis (activating bcl-2 and inhibiting caspase-3) and improve BMSC migration (increasing HIF-1α and CXCR4) in vitro. Conclusion HP could significantly enhance the capacity of BMSCs to repair DDD by increasing the survival and migration of implanted cells and increasing matrix protein expression.

Hypoxic preconditioned bone mesenchymal stem cells ameliorate spinal cord injury in rats via improved survival and migration

“…P3 BMSCs were subjected to HP induced by 100 µ M cobalt chloride (CoCl 2 ) as described previously ( 37 , 38 ). Following pretreatment of BMSCs with HP for 0, 6, 12, 24 and 48 h, the proliferative activity of the cells was measured by Cell Counting Kit-8 (CCK-8; Beyotime Institute of Biotechnology, Haimen, China), and the apoptosis rate was examined by using a flow cytometer (FAC500; Beckman Coulter, Inc., Brea, CA, USA) with an Annexin V-Propidium iodide Apoptosis Detection kit (BD Biosciences, Franklin Lakes, NJ, USA) according to the manufacturer's protocol.…”

Controversies in regenerative medicine: Should intervertebral disc degeneration be treated with mesenchymal stem cells?

“…Aside from the beneficial effects of exposing MSCs to certain IVD microenvironmental condition (eg, induction of hypoxia via cobalt chloride, a chemical inducer of HIF‐1), preconditioning and differentiation of MSCs can be induced by a variety of other approaches: (a) Treatment of MSCs with specific induction medium is the most classical and well‐established approach. Recent research highlighted that the use of a certain growth factor combination (eg, TGF‐ β1 plus GDF‐5) is distinctively effective in promoting an NP phenotype .…”

Progress in research on functional mechanisms of mesenchymal stem cells

“…增强MSCs的旁分泌作用, 如低氧或γ-IFN预处理MSCs 可提高MSCs产生生物活性物质的能力 [189,190] . 通常基 因修饰MSCs可显著增强操作基因的功能, 如过量表 达CXCR4基因, 可增强修饰MSCs的迁移能力 [69] ; 过量 表达Bcl-2基因, 可增强修饰MSCs的抗凋亡能力, 修饰 细胞能够产生更多的血管内皮细胞生长因子, 显著提 高损伤心肌细胞的存活能力 [191] ; 过量表达Miro1基因, 可增强修饰MSCs的线粒体转移能力 [158] .…”