ABSTRACT
BACKGROUND: Recent studies have demonstrated that energy metabolism-related genes play important roles in intervertebral disc (IVD) cell adaptation to negative environmental factors, such as hypoxia and insufficiency of nutrient. But the effects of these genes in pressure-induced intervertebral disc degeneration remain uncertain.OBJECTTVE: To investigate continuous pressure-induced expression of energy metabolism genes: hypoxia-inducible factor 1α(HIF-lo), glucose transporter-1 (GLUT-1) and vascular endothelial growth factor (VEGF) in rabbit annulus fibrosus (AF).DESIGN: A randomized controlled experiment.SETTING: The Central Laboratory and the Laboratory of Department of Orthopaedics, Union Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology.MATERIALS: The experiment was carried out in the Central Laboratory and the Laboratory of Department of Orthopaedics, Union Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology from May to October 2005. Twenty-five Japanese white rabbits(about 4 months old, weighting 2.5-3.0 kg, provided by the Experimental Animal Center of Tongji Medical College, Huazhong University of Science and Technology) were selected to establish the animal model.METHODS: A controllable pressure-induced rabbit intervertebral disc degeneration model was adopted to impose various pressured on rabbit IVDs in vivo. The survived animals whose IVDs were compressed successfully were divided randomly into 4 groups. The IVDs were treated with no pressure as control (control group), with 15 kg axial load for 24 hours (24hours group), 72 hours (72 hours group), and 24 hours with 48 hours free for self-reparation (reparation group). Reverse transcriptase-polymerase chain reaction was used to detect the expression of HIF-1α and GLUT-1. Western Blot and immunohistochemical test were carried out for the content and distribution of VEGF.MAIN OUTCOME MEASURES: Expression of HIF-1α and GLUT-1, content and distribution of VEGF.RESULTS: Twenty of 25 rabbits entered result analysis. Two rabbits were missed because of vertebral fracture, while death of 3 rabbits within 1-3 days postoperatively caused another loss. ①HIF-1α. A very low expression was detected in the control group, while the expression in the 24 hours group was raised over 20 times than that in the control group (t=25.022, P＜0.01). The expression in the 72 hours group and reparation group decreased as compared with the 24hours group. ②GLUT-1 expressed weakly in the control group. The expression in the 24 hours group rose a lot as compared with the control group (t=18.314, P＜0.01) and the expression in the 72 hours group rose slightly than that in the 24 hours group (t =2.819, P＜0.05). The expression in the reparation group is close to that in the 24 hours group. ③Littie VEGF content was detected in the control group, while the content rose significantly in the other 3 groups. Immunohistochemical staining showed more VEGF positive stained cells in outer AF than in inner AF.CONCLUSION: Continuous pressure can strongly up-regulate the expression of energy metabolism gene: HIF-1α,GLUT-1 and VEGF in vivo. These genes play important roles in AF adaptation and reparation in over load-caused damage.
ABSTRACT
The regulatory effects of niacinamide (Nia) on intervertebral disc (IVD) aggrecan in vitro was investigated. Chiba's 10 ng/mL interleukin-1 (IL-1)-induced rabbit IVD degeneration model in vitro was established. 0.5, 0.25 and 0.05 mg/mL Nia was added to normal and degenerated IVDs for intervention. On the first and second week after intervention, safranin O-fast green staining intensity and glycosaminoglycan (GS) content were measured. The expression of aggrecan core protein was detected by RT-PCR. The results showed: (1) After treatment with 0.5 mg/mL Nia for one week, the GS content in nucleus pulposus (NP) was increased by 44.8 % as compared with control group (P＜0.01); The GS content in IL-1 induction groups was increased with the increase of Nia concentrations: After treatment with 0.5 mg/mL for one week, the GS content in NP was increased by 68.3 % as compared with control group (P＜0.01). After two weeks, GS content in NP and fibrous rings was still higher than in control group at the same period (P＜0.01)and untreated group (P＜0.01). (2) Safranin O-fast green staining revealed that with the increase of Nia concentrations, staining density in NP and fibrous rings was increased and histological structure damage to IVDs by IL-1β was alleviated. (3) RT-PCR showed that the expression of core protein gene in IL-1β-induced degenerated IVDS was increased with the increase of Nia concentrations.It was concluded that under conditions in vitro, Nia could up-regulate the expression of aggrecan in IVDs and protect IVDs from IL-1β-induced degeneration at least partially, which offers a potential choice for IVD degeneration clinical therapy.
ABSTRACT
To investigate therapeutic efficiency of Ad/CMV- hTGF-beta1 gene for rabbit intervertebral disc degeneration model. 60 Japanese white rabbits were selected to form the 1.5-L6 Anterior-Lateral-Anulus-Fibrosus-Incision-Induced model in order to simulate human intervertebral disc degeneration. 36 rabbits, whose corresponding intervertebral discs were injected with 20 microl (10 x 10(6) pfu) of Ad/CMV- hTGF-beta1 gene, constituted the therapy group, 12 were injected with 20 microl (10 x 10(6) pfu)of Ad/CMV-LacZ gene as comparison group, while 12 were only injected with equivalent capacity of saline for empty comparison group, 3 weeks after injection, examples were taken for investigation of HE staining, MRI, Western Blotting and immunohistochemical research TGF-beta1. Wide distribution of TGF-beta1 was detected by immunohistochemical research in the degenerated annulus fibrosus after injection. Western Blotting research showed significant increase of TGF-beta1 content in intervertebral discs treated with TGF-beta1 gene than comparison groups. MRI signal transformed from low to comparatively high and that intervertebral disc pathological degree improved. Ad/CMV- hTGF-beta1 gene transfection is a potential method to increase TGF-beta1 content and reverse intervertebral disc degeneration.
Subject(s)
Animals , Rabbits , Adenoviridae , Genetics , Gene Transfer Techniques , Genetic Therapy , Genetic Vectors , Intervertebral Disc , Pathology , Lumbar Vertebrae , Spinal Diseases , Drug Therapy , Transfection , Transforming Growth Factor beta , Genetics , Transforming Growth Factor beta1ABSTRACT
To investigate therapeutic efficiency of Ad/CMV- hTGF-beta1 gene for rabbit intervertebral disc degeneration model. 60 Japanese white rabbits were selected to form the 1.5-L6 Anterior-Lateral-Anulus-Fibrosus-Incision-Induced model in order to simulate human intervertebral disc degeneration. 36 rabbits, whose corresponding intervertebral discs were injected with 20 microl (10 x 10(6) pfu) of Ad/CMV- hTGF-beta1 gene, constituted the therapy group, 12 were injected with 20 microl (10 x 10(6) pfu)of Ad/CMV-LacZ gene as comparison group, while 12 were only injected with equivalent capacity of saline for empty comparison group, 3 weeks after injection, examples were taken for investigation of HE staining, MRI, Western Blotting and immunohistochemical research TGF-beta1. Wide distribution of TGF-beta1 was detected by immunohistochemical research in the degenerated annulus fibrosus after injection. Western Blotting research showed significant increase of TGF-beta1 content in intervertebral discs treated with TGF-beta1 gene than comparison groups. MRI signal transformed from low to comparatively high and that intervertebral disc pathological degree improved. Ad/CMV- hTGF-beta1 gene transfection is a potential method to increase TGF-beta1 content and reverse intervertebral disc degeneration.