摘要
目的 探讨活性维生素D对糖尿病大鼠骨代谢的影响及其分子机制.方法 6～8周龄雄性SD大鼠45只,链脲佐菌素诱导建立糖尿病大鼠模型.将糖尿病大鼠按随机表分为3组:糖尿病组(DM)、糖尿病维生素D低剂量组(LD)、糖尿病维生素D高剂量组(HD).选取健康同龄大鼠12只作为正常对照组(NC),普通饲料同步喂养.LD组和HD组分别给予0.03和0.10 μg·kg-1·d-1的1,25-二羟维生素D3(溶于0.05 ml花生油灌胃),NC组及DM组给予花生油0.05 ml/d灌胃.12周后处死各组大鼠,测定血清钙、磷、骨钙素、Ⅰ型胶原交联氨基末端肽(NTX)、24 h尿钙水平;右股骨脱钙后HE染色观察骨组织形态学变化,免疫组化法检测成骨细胞护骨素、NF-κB受体活化因子配体(RANKL)、核结合因子1(Cbfa1)的表达;荧光实时定量PCR检测骨组织护骨素、RANKL、Cbfa1、骨钙素mRNA表达水平.结果 (1)DM组大鼠24 h尿钙水平较NC组显著升高(P＜0.05).(2)DM组大鼠血清骨钙素较NC组显著降低(P＜0.05),各组NTX差异无统计学意义(P＞0.05).(3)骨组织中Cbfa1 mRNA表达水平各组差异无统计学意义(P＞0.05);骨钙素mRNA表达水平DM组较NC组显著降低(P＜0.05);RANKL mRNA表达水平DM组较NC组显著降低(P＜0.05),LD、HD组较DM组显著升高(P＜0.05),HD组较LD组显著升高(P＜0.05);护骨素mRNA表达水平DM组较NC组显著降低(P＜0.05);RANKL/护骨素比值HD组较DM组显著升高(P＜0.05).结论 维生素D能通过上调骨钙素、RANKL表达等多种途径促进糖尿病大鼠的骨代谢.
Objective To study the effect of 1,25-dihydroxyvitamin D3 on bone metabolism in diabetic rats and the related molecular mechanism.Methods A total of 45 healthy 6-8 weeks old male Sprague Dawley (SD) rats were treated with streptozotocin.The streptozotocin-induced diabetic rats were randomly assigned to diabetic group (DM),low dose vitamin D treated group(LD),and high dose vitamin D treated group(HD).Another 12 healthy SD rats were used as normol control group(NC).The rats in NC group and DM group were fed with 0.05 ml/d nut oil;those in the LD group and HD group were fed respectively with 0.03 and0.10 μg · kg-1 · d-1 1,25-dihydroxyvitamin D3 dissolved in 0.05 ml nut oil.12 weeks later,serum calcium,phosphorus,osteocalcin,type Ⅰ collagen cross-linked telopeptide (NTX),and 24 h urinary calcium were determined.Right femurs were harvested for pathohistological analysis by hematoxylin-eosin (HE) staining.Expressions of osteoprotegerin,receptor activator nuclear factor κB ligand (RANKL),core binding factor α1(Cbfa1) were detected by immunohistochemical staining.The osteoprotegerin,RANKL,Cbfa1,osteocalcin mRNA levels of bone tissue were performed by realtime quantitative reverse transcription polymerase chain reaction assay.Results (1) Compared with the NC group,serum calcium and 24 h urinary calcium in LD and HD groups were significantly higher (P＜0.05) ; 24 h urinary calcium in DM group was significantly higher than that in NC group (P ＜ 0.05).(2) Serum osteocalcin level in DM and LD groups was significantly lower than that in NC group (P＜0.05) ; there was no significant difference between the serum NTX levels of all groups (P＞0.05).(3) There was no significant difference in the mRNA expression of Cbfa1 in all groups (P＞0.05).The mRNA expression of osteocalcin in DM group was significantly lower than that in NC group (P ＜0.05).The mRNA expression of RANKL in DM group was significantly lower than that in NC group (P＜0.05) ; and that in LD and HD group was significantly higher than that in DM group (P＜0.05),and that in HD group was significantly higher than that in LD group (P＜0.05).The mRNA expression of osteoprotegerin in DM group was significantly lower than that in NC group (P＜0.05).The ratio of RANKL to osteoprotegerin in HD group was significantly higher than that in DM group (P＜0.05).Conclusions Vitamin D may promote bone metabolism in diabetic rats by up-regulating the expressions of osteocalcin and RANKL or in addition to other means.
出处
《中华内分泌代谢杂志》
CAS
CSCD
北大核心
2014年第4期-,共6页
Chinese Journal of Endocrinology and Metabolism
