Notogen Inc., Toronto, ON M5G OB7, Canada.
Austin Spine, Austin, TX 78705, USA.
Int J Mol Sci. 2022 May 20;23(10):5717. doi: 10.3390/ijms23105717.
Tissue sources of pain emanating from degenerative discs remains incompletely understood. Canine intervertebral discs (IVDs) were needle puncture injured, 4-weeks later injected with either phosphate-buffered saline (PBS) or NTG-101, harvested after an additional fourteen weeks and then histologically evaluated for the expression of NGFr, BDNF, TrkB and CALCRL proteins. Quantification was performed using the HALO automated cell-counting scoring platform. Immunohistochemical analysis was also performed on human IVD tissue samples obtained from spinal surgery. Immunohistochemical analysis and quantification of neurotrophins and neuropeptides was performed using an in vivo canine model of degenerative disc disease and human degenerative disc tissue sections. Discs injected with NTG-101 showed significantly lower levels of Nerve Growth Factor receptor (NGFr/TrkA, = 0.0001), BDNF ( = 0.009), TrkB ( = 0.002) and CALCRL ( = 0.008) relative to PBS injections. Human IVD tissue obtained from spinal surgery due to painful DDD show robust expression of NGFr, BDNF, TrkB and CALCRL proteins. A single intradiscal injection of NTG-101 significantly inhibits the expression of NGFr, BDNF, TrkB and CALCRL proteins in degenerative canine IVDs. These results strongly suggest that NTG-101 inhibits the development of neurotrophins that are strongly associated with painful degenerative disc disease and may have profound effects upon the management of patients living with discogenic pain.
疼痛源于退行性椎间盘的组织来源仍不完全清楚。对犬椎间盘（IVD）进行针刺损伤，4 周后注射磷酸盐缓冲盐水（PBS）或 NTG-101，14 周后收获，然后进行组织学评估，以评估 NGFr、BDNF、TrkB 和 CALCRL 蛋白的表达。使用 HALO 自动细胞计数评分平台进行定量。还对从脊柱手术中获得的人类 IVD 组织样本进行了免疫组织化学分析。使用退行性椎间盘疾病的体内犬模型和人类退行性椎间盘组织切片对神经营养因子和神经肽进行了免疫组织化学分析和定量。与 PBS 注射相比，NTG-101 注射的椎间盘神经生长因子受体（NGFr/TrkA， = 0.0001）、BDNF（ = 0.009）、TrkB（ = 0.002）和 CALCRL（ = 0.008）水平显著降低。由于患有疼痛性 DDD 而从脊柱手术中获得的人类 IVD 组织显示出强大的 NGFr、BDNF、TrkB 和 CALCRL 蛋白表达。单次椎间盘内注射 NTG-101 可显著抑制退行性犬 IVD 中 NGFr、BDNF、TrkB 和 CALCRL 蛋白的表达。这些结果强烈表明，NTG-101 抑制了与疼痛性退行性椎间盘疾病密切相关的神经营养因子的发展，并且可能对患有椎间盘源性疼痛的患者的管理产生深远影响。
