Objective To investigate the effects of human insulin-like growth factor 1 (hIGF-1) gene transfected by recombinant adenovirus vector (Ad-hIGF-1) on the apoptosis of rabbit nucleus pulposus cells induced by tumor necrosis factor α (TNF-α). Methods The intervertebral disc nucleus pulposus were harvested from 8 healthy adult domestic rabbits (male or female, weighing 2.0-2.5 kg). The nucleus pulposus cells were isolated with collagenase II digestion and the passage 2 cells were cultured to logarithm growing period, and then they were divided into 3 groups according to culture condition: DMEM/F12 medium containing 10% PBS, DMEM/F12 medium containing 10% PBS and 100 ng/mL TNF-α, and DMEM/ F12 medium containing 10% PBS, 100 ng/ mL TNF-α, and Ad-hIGF-1 (multiplicity of infection of 50) were used in control group, TNF-α group, and Ad-hIGF-1 group, respectively. The results of transfection by adenovirus vector carrying hIGF-1 gene were observed by fluorescent microscopy; the expression of hIGF-1 protein was detected by Western blot, hIGF-1 mRNA expression by RT-PCR, and the cell apoptosis rate by TUNEL and flow cytometry. Results Green fluorescence was observed by fluorescent microscopy in Ad-hIGF-1 group, indicating that successful cell transfection. The expressions of hIGF-1 protein and mRNA were detected in Ad-hIGF-1 group by Western blot and RT-PCR, while the control group and TNF-α group had no expression. The cell apoptosis rates of TNF-α group, Ad-hIGF-1 group, and control group were 34.24% ± 4.60%, 6.59% ± 1.03%, and 0.40% ± 0.15%, respectively. The early apoptosis rates of TNF-α group, Ad-hIGF-1 group, and control group were 22.16% ± 2.69%, 5.03% ± 0.96%, and 0.49% ± 0.05%, respectively; the late cell apoptosis rates were 13.96% ± 4.86%, 10.68% ± 3.42%, and 0.29% ± 0.06%, respectively. Compared with TNF-α group, the cell apoptosis rates of Ad-hIGF-1 group and control group were significantly reduced (P lt; 0.05); the cell apoptosis rate of Ad-hIGF-1 group was significantly higher than that of control group (P lt; 0.05). Conclusion Ad-hIGF-1 could inhibit the apoptosis of nucleus pulposus cells induced by TNF-α.
Objective To observe the influence on adjacent lumbar bone density after strengthening of T12, L1 segment vertebral osteoporotic compression fracture by percutaneous vertebroplasty (PVP) and percutaneous kyphoplasty (PKP) in postmenopausal female. Methods Between January 2008 and June 2011, 59 patients with T12, L1 segment thoracolumbar osteoporotic compression fracture were treated with PVP in 29 cases (PVP group) and PKP in 30 cases (PKP group), who were in accordance with the inclusion and exclusion criteria. No significant difference was found in gender, duration of menopause, disease druation, causes of injury, fractured vertebral body, and vertebral fracture classification between 2 groups (P gt; 0.05). The kyphosis Cobb angle of surgical area was measured at preoperation, 1 week after operation, and last follow-up; the lower three lumbar spine bone mineral density (BMD) of the surgical area, the femoral neck BMD, and body mass index (BMI) of patients were measured at perioperative period and last follow-up to find out the statement of anti-osteoporosis; FRAX online tools were used to evaluate the probability of major osteoporotic fracture and hip fracture of the next 10 years. Results The average follow-up was 25.5 months (range, 12-48 months) in 2 groups. There was significant difference in kyphosis Cobb angle of T12, L1 between preoperation and last follow-up in 2 groups (P lt; 0.05); the Cobb angle of PKP group was significantly less than that of PVP group at 1 week after operation and last follow-up (P lt; 0.05). No significant difference was found in BMI between 2 groups, and between perioperative period and last follow-up in the same group (P gt; 0.05). The lower three lumbar spine BMD of the surgical area and its T value at last follow-up was improved significantly when compared with BMD at perioperative period (P lt; 0.05); there was no significant difference in the lower three lumbar spine BMD and its T value between 2 groups at perioperative period (P gt; 0.05), but significant difference was found between two groups at last follow-up (P lt; 0.05). Difference was not significant in the femoral neck BMD and its T value between 2 groups, and between perioperative period and last follow-up in the same group (P gt; 0.05). The probability of major osteoporotic fracture and hip fracture of the next 10 years was not significantly different between 2 groups and between perioperative period and last follow-up in the same group (P gt; 0.05). Conclusion The increased BMD of adjacent lumbar spine can improve the strength of the vertebral body and reduce the incidence of adjacent vertebral fracture in patients with T12, L1 segment vertebral osteoporotic compression fracture after PVP/PKP, and PKP is superior to PVP increasing BMD of adjacent lumbar spine.