Experimental study on inhibitory effect of niacinamide on tumor necrosis factor-alpha-induced matrix degradation of annulus fibrous tissue in vitro

Abstract

The inhibitory effect of niacinamide on tumor necrosis factor-α (TNF-α) induced annulus fibrous (AF) degradation was assessed, and the mechanism of the inhibition was investigated. Chiba’s intervertebral disc (IVD) culture model was established. Forty-eight IVDs from 12 adult Japanese white rabbits were randomly divided into 4 groups (12 IVDs in each group), and various concentrations of niacinamide and TNF-α were added to the medium for intervention: negative control group, niacinamide control group (0.5 mg/mL niacinamide), degeneration group (10 ng/mL TNF-α), and treatment group (0.5 mg/mL niacinamide and 10 ng/mL TNF-α). After one week’s culture, AFs were collected for glycosaminoglycan (GS) content measurement, safranin O-fast green staining, and immunohistochemical staining for type I, II collagen and cysteine containing aspartate specific protease-3 (Caspase-3). It was found that the GS content in treatment group was increased by about 48% as compared with degeneration group (t=16.93, P<0.001), and close to that in niacinamide control group (t=0.71, P=0.667). Safranine O-fast green staining exhibited higher staining density and better histological structure of AF in the treatment group as compared with the degeneration group. Immunohistochemical staining for both Type I and II collagen demonstrated that lamellar structure and continuity of collagen in treatment group were better reserved than in degeneration group. Positive staining rate of Caspase-3 in AFs of negative control group, niacinamide control group, degeneration group and treatment group was 3.4%, 4.3%, 17.9% and 10.3% respectively. The positive rate in treatment group was significantly lower than in degeneration group (P<0.01). It was concluded that niacinamide could effectively alleviate TNF-α induced destruction and synthesis inhibition of matrix ingredients in AFs. The inhibition may be related with reduction of expression of Caspase-3. Thus, niacinamide is of potential for IVD degeneration clinical treatment.

Keywords

intervertebral disc degeneration / niacinamide / tumor necrosis factor-alpha

References

[1] HoylandJ. A., Le MaitreC., FreemontA. J.. Investigation of the role of IL-1 and TNF in matrix degradation in the intervertebral disc. Rheumatology (Oxford), 2008, 47(6): 809-814

[2] SeguinC. A., PilliarR. M., RoughleyP. J., et al.. Tumor necrosis factor modulates matrix production and catabolism in nucleus pulposus tissue. Spine, 2005, 30(17): 1940-1948

[3] WangD. L., JiangS. D., DaiL. Y.. Biologic response of the intervertebral disc to static and dynamic compression in vitro. Spine, 2007, 32(23): 2521-2528

[4] XiongX., YangS., ShaoZ., et al.. Up-regulation of niacinamide in intervertebral disc aggrecan in vitro. J Huazhong Univ Sci Technolog Med Sci, 2006, 26(1): 89-92

[5] DuanD., YangS., ShaoZ., et al.. Protective effect of niacinamide on interleukin-1beta-induced annulus fibrosus type II collagen degeneration in vitro. J Huazhong Univ Sci Technol [Med Sci], 2007, 27(1): 68-71

[6] ChibaK., AnderssonG. B., MasudaK., et al.. A new culture system to study the metabolism of the intervertebral disc in vitro. Spine, 1998, 23(17): 1821-1827

[7] HuX. J., ShaoZ. W.. The in vivo effects of tumor necrosis factor-α on the degeneration of rabbit lumbar intervertebral disc. Chin J Spine & Spinal Cord (Chinese), 2006, 16(7): 541-544

[8] XiongX. Q., ShaoZ. W., YangS. H.. The research advancement of aggrecan and intervertebral discs degeneration. Chin J Spine & Spinal Cord (Chinese), 2005, 15(1): 54-56

[9] KroemerG., ReedJ. C.. Mitochondrial control of cell death. Nat Med, 2000, 6(5): 513-519