脂肪细胞特异性核酸适体对肥胖小鼠脂肪代谢的影响

Adipocyte specific aptamer impact on lipometabolism in obesity mouse

目的通过研究体外筛选的脂肪细胞特异性核酸适体adipo 8在肥胖小鼠体内是否可以与脂肪组织特异性结合,初步探讨adipo 8在肥胖小鼠体内对脂肪组织成脂的影响作用。方法 1高脂喂养雄性C57BL/6小鼠60只复制肥胖小鼠模型;2取小鼠4只,腹腔注射cy 3荧光标记并硫代碱基修饰,结合聚乙二醇的adipo 8,注射后1 h取肝脏、肾脏、肌肉及附睾脂肪组织于冷冻切片机制成冰冻切片2块,荧光显微镜下观察各组织荧光信号和HE染色;3取小鼠24只分为未修饰adipo 8组和修饰adipo 8组,每组12只。Cy 3荧光标记的未修饰和修饰adipo 8分别腹腔注射入两组小鼠体内,注射后30 min、1 h、2 h、4 h、8 h、24 h分别取附睾脂肪组织制成冷冻切片,荧光显微镜下显像;432只小鼠分为随机序列组和adipo 8组,每组16只。微型渗透压泵埋入小鼠腹腔,分别连续腹腔输注随机序列和修饰adipo 8,于连续腹腔输注第1、2、3、4周,分别取附睾脂肪组织制成冷冻切片,HE染色观察分析脂肪细胞大小改变。结果 1腹腔注射cy 3荧光标记并修饰的adipo 8,1 h荧光显微镜下观察显示:脂肪组织可见非常强的荧光信号,而其余组织仅可见微弱信号;2未修饰adipo 8与脂肪组织结合弱且作用时间短,修饰adipo 8与脂肪组织结合强且时间长。修饰adipo 8组中,脂肪组织的荧光信号呈先增后减,1 h最强,30 min和24 h信号弱;3光学显微镜相同放大倍数单个视野内,第1周,adipo 8组脂肪细胞大小较随机序列组无明显差异(P>0.05),第2、3、4周,adipo 8组脂肪细胞小于随机序列组(P<0.05)。结论 1核酸适体adipo 8在肥胖小鼠体内可与白色脂肪组织高度特异性结合;2Adipo 8经硫代碱基修饰、结合聚乙二醇,增强了其与脂肪组织结合的强度及延长结合时间;3Adipo 8在肥胖小鼠体内可以抑制脂肪组织成脂,并且该作用随着时间的延长而加强,即adipo 8在体内抑制成脂的作用呈时间依赖性。

[Objective] To investigate in vitro screening the adipocyte specific aptamer adipo 8 can com- bine with adipose tissue specifically in obesity mouse and adipo 8 impact on adipogenic in obesity mouse preliminarily. [Methods] 60 Obesity mouse model were established through feeding high fat diet to male C57BL/6 mouse. 4 mouse received intraperitoneal injection phosphorothioate modified and with polyethylene glycol adipo 8 fluorescein labeled by cy 3. Taking the liver, kidney, muscle and epididymal adipose tissue made into two frozen sections using freezing microtome after injection of 1 h, observed the tissue fluorescence signal using the fluorescence microscope and HE staining. 24 mouse divided into unmodified adipo 8 and modified adipo 8 groups, each of 12. They received intraperitoneal injection unmodified or modified adipo 8 fluorescein labeled by cy 3 separately. Taking the epididymal adipose tissue made into frozen section and im- aged using the upright fluorescence microscope after injection of 30 min, 1 h, 2 h, 4 h, 8 h, 24 h. 32 mouse divided into random sequence and adipo 8 groups, each of 16. The mini-osmotic pumps embedded into mouse peritoneal. Two groups accepted continuous intraperitoneal infusion random sequence or modified adipo 8 respectively. Taking epididymal adipose tissue made into frozen section, observed adipocyte size using HE staining 1, 2, 3, 4 week later respectively. [Results] Intraperitoneal injection modified adipo 8 fluorescein la- beled by cy 3 for 1 h, the result showed it was very strong fluorescence signal in adipose tissue while the other was only weak signals under the upright fluorescence microscope. Unmodified adipo 8 combined with adipose tissue weak and short time and modified adipo 8 was strong and long. In group of modified adipo 8, the fluorescence signal of adipose tissue first increased and then decreased. It was the strongest at 1 h and only weak signal at 30 min and 24 h. It showed that the adipocyte size was no significant difference between adipo 8 group and random sequence group in the first week （P 〉0.05） and it was smaller than random se- quence group from the second to the forth week （P〈0.05） by using optical microscope with the same magnifi- cation single vision observation. [Conclusions] Adipo 8 can combine with white adipose tissue specifically in obesity mouse. Adipo 8 by phosphorothioate modified and with polyethylene glycol, enhances its binding with adipose tissue strength and extends the time. Adipo 8 can inhibit adipogenic in obesity mouse and the effect is strengthen with the extension of time, namely the effect of adipo 8 inhibition of adipogenic is time depen- dent in vivo.