Prevention of alcohol-induced osteonecrosis of femoral head in rabbits by small interfering RNA targeting specific gene by gavage

Abstract

Objective To observe the effect of small interfering RNA (siRNA) adenovirus vectors targeting PPARγto prevent the alcohol-induced osteonecrosis of the femoral head (ONFH) in rabbits.Methods Ninety-six rabbits were randomly divided into four groups. In group N, normal saline ( 10 ml/kg every day) was poured into stomach. In group M, the strong wine (the volume fraction was 46% alcohol,10 ml/kg every day) was poured into stomach. In group S, under the randomly selected side and anesthesia, the animals were injected with 25 μl siRNA adenovirus drip into the femoral head and then the puncture hole was closed on the 1st day at the 1st, 3rd and 5th month of the experiment, and at the same time the strong wine (the volume fraction was 46% alcohol, 10 ml/kg every day) was poured into stomach. In group CO, animals were treated with the same method as the group S, but not injected with siRNA adenovirus drip. The animals were sacrificed in batches at 2nd, 4th and 6th month after the experiment. The serology and pathological changes of the femoral head were studied. Results At the 6th month, the triglyceride (TG, mmol/L) contents in groups N, M, CO and S were (1.21 ±0. 12), (4.59 ± 1.58), (4.63 ±1.17) and (4. 32 ± 1.20), the cholesterol levels ( CHO, mmol/L) were (2. 35 ± 0. 33), ( 19. 59 ±1.58), (20. 13 ± 1. 17) and ( 18.32 ± 1.20), the average diameter of the max adipocyte (μm) was (40. 89 ± 2. 41 ), (48.65 ± 2.93 ), (49. 45 ± 2. 63 ) and ( 42. 52 ± 2. 57 ), the trabeculace area fraction was (41.80 ±2. 47)%, (30. 70 ±2. 86)%, (29. 80 ±2. 69)% and (41.60 ±2. 87)%, the percentage of empty osteocyte lacunae was (12.30 ± 1.73)%, (22.40 ± 1.52)%, (23. 10 ± 1.62)% and (11.70 ±1.46)%, the expreasion levels of PPARγ mRNA were (0.29 ±0.05), (0.66±0. 12), (0.61±0.15) and (0. 33 ± 0. 05 ), the expression levels of osteocalcin mRNA were (0. 92 ± 0. 07 ), (0. 19 ± 0. 11 ), (0. 23 ±0. 08) and (0. 88 ± 0. 11 ), the expression levels of PPARγprotein were ( 0. 75 ± 0. 08 ), ( 1.60 ± 0. 11 ),(1.55 ±0. 12) and (0.65 ±0.05), respectively. In groups M and CO, the pathological changes were obvious; there was decreased hematopoietic tissue, proliferation and hypertrophy of the adipocytes, increased fatty tissue, and thinned, sparse or breoken bone trabeculae in the femoral head; the area fraction of the trabeculae was reduced. In group S, the average diameter of the max adipocyte, percentage of empty osteocyte lacunae, incidence of ONFH, the expressions of PPARγmRNA and protein were obviously reduced as compared with groups M and CO (P ＜0. 01,P ＜0. 05). There was no statistically significant difference between group S and group N (P ＞ 0. 05). Conclusion siRNA adenovirus vectors targeting PPARγcan efficaciously suppress the expression of PPARγ gene and adipogenic differentiation of the MSCs in the femoral head induced by alcohol, which may prevent the development of the alcohol-induced ONFH in rabbits. Key words: siRNA; PPARγ; Alcohol; Osteonecrosis of femoral head; Rabbit; Prevent