西罗莫司的作用机制及应用研究进展

西罗莫司是一种大环内酯类抗生素，为一种免疫抑制剂，结构与他克莫司（FK506）相似，但其作用机制却与神经钙蛋白阻滞剂类免疫抑制剂如环孢素A（CsA）和FKS06等完全不同。近年来研究发现，它在抗移植排斥反应、抗肿瘤、预防支架植入术后再狭窄等方面均有作用。本文主要介绍了西罗莫司的作用机制及其应用的研究进展。     

西罗莫司高产突变株FC904-33

西罗莫司是吸水链霉菌FC904产生的新型强效免疫抑制剂。为了获得高产西罗莫司突变株,采用UV、硝苯胍和甲基磺酸乙酯诱变剂诱变处理吸水链霉菌FC904的孢子悬液和发芽孢子,随后用西罗莫司对存活菌株进行自身代谢产物的耐受性试验,获得西罗莫司高产突变株FC904-33,其生物合成能力是原出发菌株的4.6倍。本文报道该突变株的培养特征、对抗生素的敏感性、西罗莫司生产能力和副产物等。     

西罗莫司与器官移植

西罗莫司(SRL),是一种大环内酯抗生素类免疫抑制剂。1975年加拿大Ayerst研究室从太平洋Easter岛的土壤样品中分离链霉菌AYB-944产生的代谢产物,1977年SRL被发现具有免疫抑制作用,1999年9月美国国家食品药品管理局(FDA)批准上市,用于预防肾移植术后的急性排斥反应。由于SRL在肾移植术后的免疫抑制治疗中取得了满意疗效,临     

3L自动发酵罐中西罗莫司的发酵研究

采用美国NBS公司生产的BIOFLO3000型3L发酵罐进行西罗莫司发酵代谢过程的考察和代谢参数的累积,建立了较为适应的西罗莫司发酵条件,罐上发酵水平与摇瓶发酵水平相当.     

人工神经网络模型在肾移植患者西罗莫司个体化给药中的应用

目的:建立人工神经网络用于估算西罗莫司血药浓度的方法。方法:收集56例肾移植患者口服西罗莫司的182份全血浓度数据,采用遗传算法配合动量法优化网络参数,建立人工神经网络,并对测试数据进行处理,验证测试结果。结果:人工神经网络平均预测误差(MPE)与平均绝对误差(MAE)分别为(0.31±1.14)、(0.89±0.77)ng·mL-1,32例/次(88.9%)血药浓度数据绝对预测误差≤2.0ng·mL-1。人工神经网络模型准确性及精密度优于多元线性回归及非线性混合效应模型。结论:人工神经网络模型可用于预测西罗莫司血药浓度,指导个体化给药。     

姜黄素抗抑郁作用的研究

目的 研究姜黄素在西罗莫司介导后的抗抑郁作用。方法 在细胞实验中,实验分为空白组、模型组、阳性对照组(1μmol·L^-1氟西汀)、对照组(1μmol·L^-1姜黄素)、实验组(0.1 nmol·L^-1西罗莫司)、联合组(0.1 nmol·L^-1西罗莫司+1μmol·L^-1姜黄素)。除空白组外,其余各组用皮质酮建立SH-SY5Y细胞损伤模型,用CCK-8法检测细胞存活率,用荧光显微镜观察细胞突触变化。在动物实验中,将40只雄性ICR小鼠随机分为空白组、对照A组(50 mg·kg^-1姜黄素)、对照B组(150 nmol·L^-1西罗莫司)、实验组(150 nmol·L^-1西罗莫司+50 mg·kg^-1姜黄素)。各组均给予小鼠急性应激造模,并考察行为学指标变化。结果 模型组、对照组和联合组的细胞存活率分别为(32.38±5.45)%,(61.67±4.53)%和(39.40±12.33)%,突触长度分...     

西罗莫司结构修饰的研究进展

自西罗莫司作为免疫抑制剂应用于临床以来,便受到了人们的广泛关注。随着研究的深入,其生物利用度低、疏水性差以及结构不稳定等缺点的存在,使得该抗生素的临床应用受到了一定的限制,因此开发新型西罗莫司衍生物具有重要的研究和应用价值。近年人们对西罗莫司进行了大量的结构修饰研究,并从中获得了一系列有价值的衍生物。本文对西罗莫司结构修饰的最新研究进展作了一个简要的综述,并重点对几个结构修饰成功的西罗莫司衍生物作了较为详细的介绍。     

肾移植术后西罗莫司的应用方案选择

本综述总结西罗莫司用于预防肾移植术后排斥反应的各种用药方案,从急性排斥发生率、肾功能、人/肾存活率4个方面综合比较各种用药方案同其他传统免疫抑制方案的优劣。综合比较显示,肾移植术后转换使用西罗莫司是最值得推荐的用药方案。在环孢素与西罗莫司联用（CsA＋SRL）过程中减、停环孢素也是可以考虑的方案,但要注意控制西罗莫司浓度。西罗莫司可以替换麦考酚酸酯,此时钙调神经蛋白抑制剂（CNI）应适当减量。起始低剂量西罗莫司与CNI联用（CNI＋SRL）,以及起始足量CNI＋SRL并维持、起始不含CNI以及术后移植肾功能延迟恢复（DGF）过渡期使用西罗莫司均应当避免。西罗莫司支持术后撤停激素,此种情况下推荐西罗莫司与他克莫司联用。需定期监测西罗莫司谷浓度,并多数情形下推荐使用首剂负荷剂量。     

儿童患者西罗莫司血药浓度监测及临床应用分析

目的:探讨西罗莫司在儿童患者中的血药浓度,考察血药浓度与相关实验室指标的关系,为西罗莫司的合理应用提供更多的临床依据.方法:选择54例使用西罗莫司治疗的患儿,记录基本信息、西罗莫司全血谷浓度(CSRL)、肝功能和中性粒细胞计数(NEU)等相关信息.结果:儿童患者西罗莫司血药浓度为(8.7±5.9) ng/mL,16.7...     

西罗莫司滴丸的研制及其体外性质考察

摘 要 目的： 研制西罗莫司（SRL）滴丸,以期改善其溶解性能。方法: 对SRL滴丸的基质进行筛选;用正交试验优选SRL滴丸的最佳处方及工艺;对其平衡溶解度、吸湿性及体外释药特性进行考察。结果:选用PEG6000为SRL滴丸的基质;优选出的最佳处方及制备条件为：SRL与基质的用量为1∶10,滴速为65滴/min,滴制温度为95℃,冷却剂温度为5℃;在不同溶剂中,SRL滴丸的平衡溶解度均较SRL有显著增加,吸湿性较强,与市售SRL纳米结晶片相比,SRL滴丸释药迅速而完全,无显著性差异。结论: SRL滴丸可显著提高SRL溶解度及改善溶出性能,值得进一步研究。     

阿司匹林对西罗莫司抗胃癌MKN45细胞体外增殖作用的影响研究

目的：研究阿司匹林对西罗莫司抗胃癌MKN45细胞体外增殖作用的影响及作用机制。方法：体外培养胃癌MKN45细胞,给予西罗莫司（0、0.5、1.0、2.0nmol·L-1）、阿司匹林（10mmol·L-1）＋西罗莫司（0、0.5、1.0、2.0nmol·L-1）,以MTT法测定并计算细胞增殖抑制率;通过实时定量聚合酶链式反应（PCR）测定正常胃上皮GES-1细胞、MKN45细胞和经西罗莫司（2.0nmol·L-1）、阿司匹林、阿司匹林＋西罗莫司（2.0nmol·L-1）处理后的MKN45细胞中环氧化酶2（COX-2）、白细胞介素1α（IL-1α）表达情况。结果：西罗莫司可抑制MKN45细胞增殖,且呈剂量依赖性;与西罗莫司比较,阿司匹林＋西罗莫司处理后的MKN45细胞增殖抑制率明显增加（P〈0.01）。mRNA相对表达量COX-2MKN45/GES-1、IL-1αMKN45/GES-1分别为1.49±0.17、1.58±0.19。与对照MKN45细胞比较,COX-2、IL-1α在经西罗莫司、阿司匹林、阿司匹林＋西罗莫司处理后的MKN45细胞中的表达均明显降低（P〈0.01）,其中组间均有统计学差异（P〈0.05或P〈0.01）。结论：阿司匹林可协同增强西罗莫司抑制胃癌MKN45细胞增殖的作用,其作用机制可能与抑制COX-2、IL-1α表达有关。     

肾移植受者应用西罗莫司治疗窗的临床研究

目的:探讨西罗莫司应用于国内肾移植受者的治疗窗范围。方法:采用多中心、开放性临床研究,来自国内4家移植中心的首次肾移植病人共100例。免疫抑制方案为西罗莫司联合环孢素和皮质激素的三联疗法。移植后48h内开始服用西罗莫司,首次负荷剂量为6mg·d-1,维持剂量为2mg·d-1,采用高效液相色谱法测定西罗莫司浓度。结果:100例病人西罗莫司总的全血谷浓度为(6.6±s2.8)μg·L-1,10及90百分位数浓度分别为3.2μg·L-1和10.26μg·L-1。肾移植后6mo内急性排斥发生率为10%(8/84),此8例病人急性排斥时的西罗莫司浓度明显低于非排斥时浓度(P<0.01)。主要不良反应为肝功能损害和高脂血症,三酰甘油浓度与西罗莫司浓度相关(r=0.276,P<0.01)。结论:西罗莫司浓度维持在4～8μg·L-1范围内较为合适,定期监测血药浓度,合理调整用量,可增加西罗莫司应用的有效性及安全性。     

药物相互作用致三酰甘油升高1例

目的 报道并分析西罗莫司致高三酰甘油血症1例,提高临床重视西罗莫司对血脂代谢的影响。方法 1例肝移植病人使用西罗莫司后引起高三酰甘油血症的关联性评价及查阅文献印证。结果 住院第7日查血生化示:总胆固醇2.80 mmol/L,三酰甘油7.74 mmol/L;西罗莫司血药浓度为20 ng/mL;立即停用西罗莫司。住院第14日西罗莫司血药浓度为7 ng/mL,住院第21日复查血生化示:总胆固醇2.75 mmol/L,三酰甘油4.77 mmol/L。结论 该肝移植术后病人并发高三酰甘油血症很可能是西罗莫司引起。在应用西罗莫司时,应严密监测病人血脂情况,一旦出现三酰甘油值增加,应及时调整西罗莫司给药方案以期维持其血药浓度在基线范围内,从而降低其对血脂代谢的影响。     

西罗莫司滴眼液在兔眼房水内的药动学

目的探讨西罗莫司滴眼液单次滴兔眼后在房水中的药动学特征。方法 40只新西兰大白兔,局部滴入西罗莫司滴眼液50μL,采用高效液相色谱法测定兔眼房水中西罗莫司的药物浓度,用DAS1.0软件计算药动学参数。结果给药后0～120 h,西罗莫司在兔眼房水中的ρ_(max)为(84.92±37.04)μg·mL~(-1)(-1),t_(1/2)为(43.28±18.11)h,AUC_(0-6)为(1 747.44±571.36)μg·h·mL~(-1),AUC_(0-∞)为(2 335.25±702.42)μg·h·mL~(-1)。空白房水不干扰西罗莫司的含量测定。结论单次滴眼后西罗莫司可以快速穿透眼组织到达前房,并在房水中达到较高的药物浓度。     

西罗莫司脂质体的体外释放研究

目的:研究西罗莫司脂质体的体外释放特性。方法:建立反相高效液相色谱法测定西罗莫司含量;采用反透析法,以500mL 20%乙醇为释放介质,考察24 h不同时间西罗莫司脂质体的体外累积释放率,利用药物释放模型方程拟合释放曲线。结果:西罗莫司检测浓度的线性范围为0.5～20 μg.mL~(-1)(r=0.999 8),平均回收率为99.42%,RSD=1.23%;脂质体前4 h的释药速率快,累积释放率为50%,之后释药相对缓慢,24 h的累积释放率为80%,释放曲线符合一级动力学方程。结论:西罗莫司脂质体具有一定缓释效应,其体外释放属于浓度依赖型渗透释药。     

Reccurence of Kaposi's sarcoma after increased exposure to sirolimus

The conversion to sirolimus treatment is recently indicated as an effective therapy of Kaposi's sarcoma (KS) in transplant patients. We present two treatment modalities in patients with KS and recurrence of the disease after increasing sirolimus dose. Among 1034 renal transplants performed at our center, three (0.3%) suffered from KS. Initial immunosuppression consisted of cyclosporine, azathioprine and prednisone in one patient; and tacrolimus, mycophenolate mofetil and prednisone in two patients. KS symptoms appeared within one year post-transplantation. Two patients developed cutaneous tumor; one disseminated disease, including the skin, mediastinal lymph nodes and both lungs. After histological confirmation of KS immunosuppression was minimized: Two were converted to sirolimus (1-2 mg/day, level 5-8 ng/ml) treatment; the third patient discontinued tacrolimus and was administered 1 g/day mycophenolate mofetil. Gradual regression of KS was observed in all the patients. In one patient, 8 months after regression of lung KS, the dose of sirolimus was increased to 2 mg/day (level raised to 13.8 ng/ml). Recurrent disease developed afterwards involving diffuse interstitial infiltrates with nodular changes in both lungs. For the second time the dose of sirolimus was reduced to 1 mg/day (level 4-5 ng/ml) and lung lesions regressed 5 months later. Renal function was stable (creatinine 1.3-1.9 mg/dl) in all patients, 24 months from KS onset. In conclusion: treatment by low sirolimus or mycophenolate mofetil doses caused regression of KS. Recurrence of KS after increasing sirolimus dose suggests that regression of KS is a result of diminished immunosuppression, not the direct antineoplastic effect of sirolimus. Careful maintenance of low sirolimus levels is suggested.     

Trimethoprim-sulphamethoxazole does not affect the pharmacokinetics of sirolimus in renal transplant recipients

AIMS: The influence of the trimethoprim-sulphamethoxazole combination on the steady-state pharmacokinetics of sirolimus, a potent macrocyclic immunosuppressant, was studied in renal transplant recipients. METHODS: Fifteen kidney transplant recipients were treated with sirolimus 8-23 mg m(-2) in combination with azathioprine and prednisolone from the day of transplantation. Whole blood sirolimus AUC and C(max) were determined on days 6 and 7 after transplantation. On day 7, sirolimus was coadministered with the first dose of trimethoprim (80 mg) and sulphamethoxazole (400 mg). RESULTS: On day 6, the mean (95% confidence interval) whole blood sirolimus AUC((0-24 h)) was 1040 (846, 1234) ng ml(-1) and mean C(max) was 109 (88, 129) ng ml(-1). Corresponding values on day 7 were AUC((0-24 h)) 1060 (826, 1293) ng ml(-1) and C(max) mean 107 (87, 127) ng ml(-1). The mean difference in the dose-corrected AUC((0-24 h)) was 0.40% (-9.4, +10). CONCLUSIONS: A single dose of trimethoprim-sulphamethoxazole does not affect the pharmacokinetics of sirolimus in renal transplant patients.     

Preincubation With Everolimus and Sirolimus Reduces Organic Anion-Transporting Polypeptide (OATP)1B1- and 1B3-Mediated Transport Independently of mTOR Kinase Inhibition: Implication in Assessing OATP1B1- and OATP1B3-Mediated Drug-Drug Interactions

Organic anion transporting polypeptides (OATP)1B1 and OATP1B3 mediate hepatic uptake of many drugs including lipid-lowering statins. Current studies determined the OATP1B1/1B3-mediated drug-drug interaction (DDI) potential of mammalian target of rapamycin (mTOR) inhibitors, everolimus and sirolimus, using R-value and physiologically based pharmacokinetic models. Preincubation with everolimus and sirolimus significantly decreased OATP1B1/1B3-mediated transport even after washing and decreased inhibition constant values up to 8.3- and 2.9-fold for OATP1B1 and both 2.7-fold for OATP1B3, respectively. R-values of everolimus, but not sirolimus, were greater than the FDA-recommended cutoff value of 1.1. Physiologically based pharmacokinetic models predict that everolimus and sirolimus have low OATP1B1/1B3-mediated DDI potential against pravastatin. OATP1B1/1B3-mediated transport was not affected by preincubation with INK-128 (10 μM, 1 h), which does however abolish mTOR kinase activity. The preincubation effects of everolimus and sirolimus on OATP1B1/1B3-mediated transport were similar in cells before preincubation with vehicle control or INK-128, suggesting that inhibition of mTOR activity is not a prerequisite for the preincubation effects observed for everolimus and sirolimus. Nine potential phosphorylation sites of OATP1B1 were identified by phosphoproteomics; none of these are the predicted mTOR phosphorylation sites. We report the everolimus/sirolimus-preincubation-induced inhibitory effects on OATP1B1/1B3 and relatively low OATP1B1/1B3-mediated DDI potential of everolimus and sirolimus.     

HPLC-MS/MS法测定全血中西罗莫司的药物浓度

目的:建立简便、快速地测定人全血中西罗莫司血药浓度的HPLC-MS/MS方法。方法:全血样品经硫酸锌及含有子囊霉素(内标)的乙腈溶液沉淀后,取上清液20μL进样分析。采用Symmetry-C18色谱柱(2.1 mm×50 mm,3.5μm),流动相梯度洗脱,流速为0.5 mL.min-1,质谱采用电喷雾离子化电离源,经多反应监测模式检测。结果:西罗莫司和子囊霉素的保留时间分别为2.24 min和2.21 min,空白血浆中内源性物质不干扰测定;西罗莫司的血药浓度在1~30 ng.mL-1时,线性关系良好(r=0.999 5);日内、日间RSD值均小于10%,提取回收率为86.4%~90.4%。结论:本方法灵敏、准确、简单、快速,可用于西罗莫司的血药浓度监测和早期肝移植患者药代动力学研究。     

Tacrolimus and sirolimus decrease oxidative phosphorylation of isolated rat kidney mitochondria

1. Tacrolimus and sirolimus are potent immunosuppressors used in transplantation. Tacrolimus has been suspected to alter mitochondrial respiration of different tissues but sirolimus has not been evaluated. 2. We evaluated the in vitro effect of tacrolimus and sirolimus on oxidative phosphorylation of isolated rat kidney mitochondria. 3. Oxygen consumption was measured with a Clark-type electrode. Tacrolimus and sirolimus increased the resting rate (state 4) and had no significant effect on ADP-stimulated respiration (state 3). The decrease of respiratory control ratio was concentration-dependent with a biphasic curve for tacrolimus. The EC(50)s were 3.4 x 10(-11) M and 2.3 x 10(-8) M for tacrolimus and 4.4 x 10(-10) M for sirolimus. The maximal inhibition was 20 and 14% for tacrolimus and sirolimus, respectively. 4. Tacrolimus and sirolimus had an uncoupling effect on oxidative phosphorylation related to a decrease of the inner membrane fluidity. At the opposite of cyclosporin A, no effect on swelling or Ca(2+) fluxes was observed. 5. All events occurred at therapeutic concentrations and then could appear during long-term treatment. Cellular consequences such as chronic nephrotoxicity with tacrolimus are suggested. The risk of cyclosporin A nephrotoxicity potentiation by sirolimus is discussed.