磷酯酰肌醇-3-激酶、丝氨酸／苏氨酸蛋白激酶在2型糖尿病大鼠骨组织中的表达及意义

Expression and roles of phosphatidylinositol-3-kinase, serine/threonine protein kinase in bone of type 2 diabetic rats

目的探讨磷酯酰肌醇-3-激酶（P13K）、丝氨酸／苏氨酸蛋白激酶（Akt）在糖尿病大鼠骨组织中的表达及意义。方法将50只体重180—200g的6月龄雌性Wistar大鼠按随机数字表法分为对照组（n=24）和2型糖尿病组（n=26）。2型糖尿病组大鼠予高糖高脂饮食喂养8周后，腹腔注射链脲佐菌素30mg／kg，对照组大鼠正常饮食。糖尿病成模后12周两组大鼠分别行腰椎骨密度测定；应用逆转录聚合酶链反应（RT—PCR）法检测骨组织P13K、Aktl和Akt2mRNA的相对表达。组间比较采用t检验。结果对照组大鼠骨密度高于糖尿病组，差异有统计学意义[（0．079±0．034）比（0．060±0．017）g／cm2，t=2．499，P〈0．05]；同时，对照组大鼠骨组织P13K、Aktl、Akt2mRNA均高于糖尿病组（分别为：0．65±0．05比0．51±0．04、0．756±O．031比0．694±0．017、0．77±0．04比0．66±0．04），差异均有统计学意义（t=4．969、3．924、4．515，均P〈0．01）。结论2型糖尿病大鼠骨组织P13K、Aktl及Akt2表达低于正常，这可能是2型糖尿病骨质疏松发生的分子生物学机制之一。

Objective To investigate the expression and roles of phosphatidylinositoi-3-kinase （PI3K） , serine/threonine protein kinase（Akt） 1 and Akt2 mRNA in bone of diabetic rats. Methods Fifty female Wistar rats aged 6-month, were randomly divided into control group （ NS group, n = 24） and diabetes group （DM group, n = 26 ）. The DM group were made by feeding with high-sugar-fat diet 8 weeks and injected small doses of streptozotocin （STZ） （30 mg/kg）, while the NS group were fed with normal diet. After 12 weeks, PI3K, Aktl and Akt2 mRNA in bone were measured respectively by RT-PCR. The t test was used for statistics. Results Compared with the NS group, the bone mineral density （BMD） levels of the DM group was significantly decreased （ （ 0. 079 ± 0. 034 ） vs （ 0. 060 ± 0. 017 ） g,/cm2, t = 2. 499, P 〈 0. 05）, and the expression of PI3K, Aktl and Akt2 mRNA in bone tissue of the DM group was also decreased （0. 65 ± 0.05 vs 0. 51 ± 0. 04, 0. 756 ± 0. 031 vs 0. 694 ± 0. 017, 0. 77 ± 0. 04 vs 0. 66 ± 0. 04, t = 4. 969,3. 924 and 4. 515, all P 〈 0. 01 ）. Conclusion Decreased expression of PI3K, Aktl and Akt2 mRNA in bone may be one of the pathogenesis in type 2 diabetic osteoporosis.