免疫抑制剂FK506在排斥反应中的应用及其肝肾毒性研究

目的:对排斥反应的分类,诊断标准及免疫抑制剂FK506的临床应用和肝肾毒性加以综述.方法:查阅近年来国内外相关文献,对其进行分析比较.结果:在器官移植领域,免疫抑制剂FK506具有高效,不良反应少等优点,但仍不可忽略其肝肾毒性.结论:FK506是一种很有前途的免疫抑制剂,以其众多优点和广泛作用逐渐成为器官移植和自身免疫性疾病的首选药物.     

FKBP12 Depletion Leads to Loss of Sarcoplasmic Reticulum Ca2+ Stores in Rat Vas Deferens

The immunophilin 12-kDa FK506 binding protein (FKBP12) stabilizes intracellular Ca²⁺ release channel (CRC) activity in different tissues. In this work, the presence of FKBP12 in rat vas deferens (RVD) and its possible contribution to RVD function was investigated. Treatment under appropriate pH, temperature, and ionic conditions was used to strip FKBP12 from CRC binding sites; Western blotting revealed FKBP12 in control but not in treated homogenates. Disruption of the FKBP12-CRC complex in RVD decreased the Ca²⁺ content of sarcoplasmic reticulum (SR) by increasing Ca²⁺ leakage through the ryanodine receptor (RyR3 isoform) but not through 1,4,5-iNOSitol trisphosphate receptors (IP₃R1 and IP₃R3 isoforms). The decrease of SR Ca²⁺ content was not related to inhibition of SERCA ATPase. It seems that dissociation of FKBP12-RyR leads to conformational changes in RyR that make it difficult for ryanodine to access its binding site. Rapamycin, which is commonly used as a pharmacological tool to disrupt the FKBP12-RyR complex, decreased phenylephrine-induced contractions in RVD epididymal halves. The data suggest that FKBP12 is expressed in RVD in a labile association with RyR3. Disruption of the FKBP12-RyR3 complex may lead to modifications of RVD physiology and in consequence may compromise male fertility.     

Tacrolimus ointment improves psoriasis in a microplaque assay

Tacrolimus (FK506) is an effective and well tolerated immunosuppressant used to prevent allograft rejection. We describe the evaluation of two tacrolimus ointment formulations for treatment of chronic plaque-type psoriasis. This was a microplaque assay with randomized, double-blind design. Sixteen patients (15 men, one woman, all white and 28-69 years old) with chronic plaque-type psoriasis participated. Six different ointments were applied to discrete microplaques, 17 mm in diameter, on a descaled psoriasis lesion: these were tacrolimus ointment with diisopropyl adipate as penetration enhancer, tacrolimus ointment without diisopropyl adipate, 0.1% betamethasone 17alpha-valerate ointment, 0.005% calcipotriol ointment and, as controls, the ointment bases for tacrolimus and betamethasone. Ointments were reapplied and the area was sealed every 2-3 days during the 14-day treatment period. After 7 and 14 days, erythema and infiltration were graded on a scale of 0-4, and superficial blood flow was measured with a laser Doppler flowmeter. Epidermal thickness was measured histologically at the end of treatment. Compared with the vehicle controls, sites treated with tacrolimus ointment (with or without penetration enhancer) showed a significant reduction in erythema and infiltration (P < 0. 001), a significant reduction in superficial blood flow (P < 0.01) and a significant decrease in epidermal thickness (P < or = 0.001). Results for betamethasone and calcipotriol, when compared with the vehicle controls, were similar. These results suggest that, under conditions of descaling and occlusion, tacrolimus ointment is effective in the treatment of psoriasis.     

FK506对大鼠心脏移植细胞凋亡的作用

目的　观察大鼠心脏移植急性排斥反应中的细胞凋亡现象及FK5 0 6对它的影响。方法　进行 48次SD→Wistar的大鼠颈部心脏移植 ,用苏木素 伊红 (HE)染色和原位末端标记(TUNEL)技术检测移植心切片 ,进行排斥反应的病理分级并计算凋亡指数 (AI)。结果　移植心的细胞凋亡主要发生于心肌细胞 ;FK5 0 6能明显减少心肌细胞的凋亡 ,减轻移植心的组织损伤。移植后第 3、5、7天AI对照组分别为 3.73± 2 .32、8.30± 2 .97、10 .2 2± 5 .5 2 ;FK5 0 6治疗组为 1.2 7± 1.2 0、2 .89± 2 .18、3.11± 1.6 8;两组比较差异有非常显著性 (P <0 .0 1)。结论　细胞凋亡是心脏移植急性排斥中组织损伤的重要机制 ;FK5 0 6能明显抑制心肌细胞凋亡 ,这可能是FK5 0 6发挥免疫抑制作用的重要方面。     

FK506-壳聚糖膜与体外培养雪旺细胞生物相容性的研究

目的 探讨FK506-壳聚糖膜片与培养的雪旺细胞生物相容性.方法 将生长状况和纯度较好的第3代雪旺细胞,分别传代接种于含有FK506-壳聚糖膜片、单纯壳聚糖膜片的培养皿中培养,以盖玻片作为对照组.计算3组雪旺细胞倍增时间、雪旺细胞纯度;用MTT法比较不同膜片上雪旺细胞的生长活力,绘制生长曲线;S-100免疫荧光染色.结果 雪旺细胞倍增时间对照组为5.9 d,单纯壳聚糖膜片及FK506-壳聚糖膜片组均为4.0 d;雪旺细胞纯度分别为80%、89%,93%;雪旺细胞增殖情况以FK506-壳聚糖组最佳,单纯壳聚糖组次之,对照组最差;各组雪旺细胞均呈S-100阳性,FK506-壳聚糖组与单纯壳聚糖组雪旺细胞排列呈典型的漩涡状或栅栏状.结论 FK506-壳聚糖膜片具有更显著的组织相容性与生物功能性,并保持了雪旺细胞的生物学特性.     

他克莫司局部缓释用药对大鼠胫神经损伤的疗效

目的:观察大鼠胫神经损伤后局部短暂应用他克莫司(FK506)纳米微球缓释颗粒对神经再生的影响。方法:Wistar大鼠36只,随机分为实验组(n=24)和对照组(n=12),实验组根据释放用药时间不同分为10 d亚组和15 d亚组各12只,建立左侧胫神经切断的端端缝合模型。于术后2周、3周分别取缝合口远侧端神经干进行变性轴索、变性髓鞘染色,观察其变性轴索、变性髓鞘、再生髓鞘纤维数。结果:术后2、3周,实验组缝合口远侧端神经干内变性轴索数少于对照组,差异有统计学意义(P<0.05);变性髓鞘数少于对照组,有显著性差异(P<0.01)。术后3周,10 d亚组髓鞘数多于15 d亚组,差异有统计学意义(P<0.05)。结论:局部短暂少量应用FK506纳米微球缓释颗粒,能缩短损伤远侧端神经溃变时间,利于药物充分吸收,减少用药部位结缔组织对局部药物缓释时的影响。     

miR-506在人结肠癌羟基喜树碱多药耐药中的功能研究

目的探讨miR-506在人结肠癌羟基喜树碱多药耐药中的潜在作用。方法首先通过PCR从基因组DNA中克隆出包含miR-506前体的片段,将其连接至miRNA表达载体pMIF-cGFP-Zeo中,测序进行验证。将构建成功的pMIF-miR-506转染至低表达miR-506的亲本细胞SW1116中,加入含G418的选择性培养基进行选择性培养。运用RT-PCR验证稳定转染pMIF-miR-506的SW1116细胞株中的miR-506的表达情况,MTT法检测稳定转染pMIF-miR-506的SW1116细胞株和亲本细胞SW1116对羟基喜树碱的敏感性差异,Annexin V/PI检测各自对羟基喜树碱的凋亡情况。结果测序结果表明hsa-miR-506的前体序列被成功地构建至miRNA表达载体pMIF-cGFP-Zeo中。TaqMan荧光定量PCR技术检测发现,相比亲本细胞SW1116,稳定表达绿色荧光的SW1116细胞克隆中miR-506的含量显著升高,约为33.7±8.3倍。细胞增殖试验表明稳定转染pMIF-miR-506的SW1116细胞株的IC50为(280±13)μg/L,而对照组SW1116的IC50为(152±12)μg/L。同时还发现在相同浓度的羟基喜树碱作用下,亲本细胞SW1116较稳定转染pMIF-miR-506的SW1116细胞株的凋亡细胞比率增高(150μg/L:7.8%±1.7%vs5.4%±1.2%;300μg/L:33.6%±3.9%vs18.2%±4.7%)。结论成功地构建了过表达miR-506的载体pMIF-miR-506;过表达miR-506能够增加SW1116对羟基喜树碱的抵抗性。     

FK506对早期糖尿病肾病大鼠足细胞损伤的保护作用

目的探讨FK506对早期糖尿病肾病大鼠肾小球足细胞损伤的保护作用。方法将38只正常雄性SD大鼠随机分为正常对照组(N组)8只、糖尿病肾病组(DN组)10只、FK506治疗组(F组)10只、洛汀新治疗组(L组)10只,其中DN组、F组、L组应用链脲佐菌素(STZ)60 mg/kg腹腔注射建立糖尿病大鼠模型。F组成模4周后给予FK506 1 mg/(kg.d)灌胃,L组成模4周后给予洛汀新10 mg/(kg.d)灌胃,DN组与N组4周后给予等量蒸馏水灌胃,每4周末监测各组大鼠血糖(BS)、体质量(BW)、24 h尿蛋白定量,药物干预8周后测定各组大鼠的血肌酐(SCr)、尿素氮(BUN)、肾质量/体质量(KW/BW),在光镜、电镜下观察肾脏病理组织学改变,应用West-ern blot印迹检测足细胞特异标记物Nephrin的蛋白表达。结果①与N组比较,DN组大鼠BS、SCr、BUN、KW/BW、24 h尿蛋白定量均明显上升(P<0.05);与DN组比较,F组和L组上述指标除BS外均明显降低(P<0.05),且F组和L组之间差异无统计学意义(P>0.05);②光镜下,肾组织病理学观察N组无明显异常,DN组可见明显的肾小球体积增大,肾小球系膜细胞增生,系膜区增宽,基底膜增厚;F组、L组较DN组病理改变明显减轻(P<0.05),且F组和L组之间病理改变无显著性差异(P>0.05);③电镜下,DN组肾小球基底膜显著增宽,足突排列紊乱,足突增宽、融合,F组、L组较DN组上述病变有所减轻(P<0.05);④Western blot结果显示,DN组肾组织Nephrin蛋白表达较N组下降60.1%(P<0.05),F组和L组可明显恢复肾组织Nephrin蛋白的表达(P<0.05)。结论 FK506可能部分通过恢复糖尿病大鼠肾组织Nephrin蛋白表达、维护足细胞结构和功能的完整而发挥减少尿蛋白、延缓DN进展的作用。     

Histomorphological and functional impacts of postoperative motor training in rats after allograft sciatic nerve transplantation under low‐dose FK 506

This study aimed to determine the effect of motor training on recovery after nerve transplantation under low‐dose FK 506. Rats (n = 30) of two strains were randomly assigned to three groups. Group I served as untreated controls; groups II and III received allograft transplants for reconstruction of the sciatic nerve and FK 506 (0.1 mg/kg/d). Nonoperated limbs served as intra‐animal controls. Group III received postoperative motor training. Functional and histomorphological outcomes were assessed by walking track analysis and by blob analysis for myelinization of nerve sections. Regeneration occurred in both groups II and III. The control sections of the nonoperated limbs in group III showed significantly higher myelinization compared with group I and II; regeneration of the operated side was superior in group II. With regard to postoperative motor training, no benefit could be seen; however, the impact of postoperative motor training on the nonoperated limb were identified. Muscle Nerve, 2009