Autoimmune hepatitis in children: diagnosis,pathology and treatment

Autoimmune hepatitis (AIH) is characterized by progressive inflammation of the liver and destruction of liver parenchyma. Rare in absolute terms, it is nevertheless an important cause of noninfectious chronic liver disease in children. In many ways, the diagnosis and treatment of children with AIH has changed little over the last 10 years. However, in recent years, steady progress in defining the genetic, immunologic and potential environmental triggers that underlie this disease, in addition to increasing experience with a wider array of therapeutic agents, promises to expand our understanding and ability to treat AIH effectively. This review will summarize the current clinical and pathophysiological understanding of AIH in children, along with therapeutic options.     

Human lymphocyte activation assay: An in vitro method for predictive immunotoxicity testing

Preclinical immunotoxicity assessments may be performed during pharmaceutical drug development in order to identify potential cause for concern prior to use in the clinic. The in vivo T-dependent antibody response (TDAR) is widely used in this regard, given its sensitivity to known immunosuppressive compounds, but may be impractical early in drug development where quantities of test article are limited. The goal of the current work is to develop an in vitro human cell-based assay that is sensitive to immunosuppression, uses relatively small quantities of test article, and is simple to perform with moderate to high throughput. Ideally, this assay would require the cooperation of multiple cellular compartments to produce a response, similar to the TDAR. Although the Mishell–Dutton assay (in vitro mouse splenic sheep red blood cell response) has been used for this purpose, it shows considerable inter-laboratory variability, and rodent cells are used which leads to potential difficulty in translation of findings to humans. We have developed an assay that measures an influenza antigen-specific response using frozen-stored human peripheral blood mononuclear cells, which we have termed the human lymphocyte activation (HuLA) assay. The HuLA assay is sensitive to cyclosporine, dexamethasone, rapamycin, mycophenolic acid, and methotrexate at concentrations within their respective therapeutic ranges. Although proliferation is the primary endpoint, we demonstrate that flow cytometry approaches may be used to characterize the proliferating lymphocyte subsets. Flu antigen-specific proliferation in the HuLA assay primarily involves both CD4⁺ and CD8⁺ T-lymphocytes and B-lymphocytes, although other lymphocyte subsets also proliferate. In addition, flu-specific antibody-secreting cells can be measured in this assay by ELISPOT, a response that is also sensitive to known immunosuppressive compounds. The HuLA assay represents a relatively straightforward assay with the capability of detecting immune suppression in human cells and can be applied to compound ranking and immunotoxicity assessment.     

雷帕霉素对豚鼠形觉剥夺性近视的干预作用及相关机制研究

目的　探讨球结膜下注射雷帕霉素对豚鼠形觉剥夺性近视（FDM）的干预作用及相关机制。方法　选取2～3周龄豚鼠80只（80眼）,雌雄不限,随机分为4组:空白对照组、FDM组、雷帕霉素组、FDM+雷帕霉素组;空白对照组不做任何处理;FDM组单纯缝合豚鼠右眼眼睑;雷帕霉素组于实验第1天、第7天豚鼠右眼球结膜下注射雷帕霉素50 μg;FDM+雷帕霉素组于实验第1天、第7天豚鼠右眼球结膜下注射雷帕霉素50 μg后再缝合右眼眼睑。记录各组豚鼠实验前及实验第7天、第14天的眼轴长度、屈光度;并取各组豚鼠视网膜行过碘酸-雪夫染色（PAS染色）及透射电镜检查,观察各组豚鼠视网膜形态变化;取各组豚鼠巩膜行RT-PCR检测巩膜组织中mTOR、基质金属蛋白酶-2（MMP-2）、α-平滑肌肌动蛋白（α-SMA）及转化生长因子β1（TGF-β1）的mRNA表达;利用Western blot 检测各组豚鼠巩膜组织中AKT、p-AKT、mTOR、p-mTOR的蛋白表达。结果　FDM组与空白对照组相比,实验第7天、第14天豚鼠的右眼眼轴长度、屈光度增加,形成了相对近视;FDM组巩膜中MMP-2、α-SMA 的mRNA相对表达量与空白对照组相比均增加,TGF-β1 mRNA相对表达量减少,差异均具有统计学意义（均为P<0.05）;与空白对照组相比,FDM组豚鼠巩膜中mTOR mRNA和AKT、P-AKT、mTOR、p-mTOR蛋白的相对表达量变化不大,差异均无统计学意义（均为P>0.05）,但视网膜变薄,各层结构排列紊乱、疏松。雷帕霉素组与空白对照组相比,实验第7天、第14天豚鼠右眼眼轴长度、屈光度差异均无统计学意义（均为P>0.05）,且视网膜形态无明显变化。FDM+雷帕霉素组与FDM组相比,实验第7天豚鼠右眼眼轴长度、屈光度差异均无统计学意义（均为P>0.05）,实验第14天右眼眼轴长度和屈光度均减小,差异均有统计学意义（均为P<0.05）,TGF-β1 mRNA的相对表达量增多,MMP-2、α-SMA、mTOR 的mRNA和AKT、p-AKT、mTOR、p-mTOR的蛋白相对表达量均减少,差异均有统计学意义（均为P<0.05）。结论　雷帕霉素球结膜下注射可延缓豚鼠FDM的形成,可能是通过抑制PI3K/AKT/mTOR信号通路、调节巩膜中的MMP-2、TGF-β1、α-SMA的表达而发挥作用的,且对正常豚鼠视网膜结构没有影响。     

哺乳动物雷帕霉素靶蛋白调控前列腺癌22RV1细胞雄激素受体及Akt磷酸化

目的:探索哺乳动物雷帕霉素靶蛋白mTORC1和mTORC2在前列腺癌22RV1细胞增殖及凋亡中的作用。方法:噻唑蓝(MTT)比色法检测mTORC1和mTORC2沉默后前列腺癌22RV1细胞增殖改变;流式细胞术(FCM)检测mTORC1和mTORC2沉默后前列腺癌22RV1细胞凋亡;Western印迹检测mTORC1和mTORC2沉默后前列腺癌22RV1细胞雄激素受体(AR)和Akt磷酸化表达。结果:MTT显示mTORC1沉默后,前列腺癌22RV1细胞的生长率无明显变化(P>0.05),而mTORC2沉默后,细胞的增殖受到了显著抑制(P<0.01);FCM显示mTORC1沉默后,细胞的凋亡率明显增加(P<0.01),而mTORC2沉默后,细胞的凋亡率无明显变化(P>0.05);Western印迹检测显示mTORC1沉默后,前列腺癌22RV1细胞中AR和Akt磷酸化表达显著增加(P<0.05),而mTORC2沉默后则显著抑制了前列腺癌22RV1细胞中AR和Akt磷酸化表达(P<0.05)。结论:mTORC2对于前列腺癌22RV1细胞的存活是必需的,mTORC2有可能成为治疗前列腺癌的一个有意义的靶点。     

Anti‐LFA‐1 or rapamycin overcome costimulation blockade‐resistant rejection in sensitized bone marrow recipients

While costimulation blockade‐based mixed chimerism protocols work well for inducing tolerance in rodents, translation to preclinical large animal/nonhuman primate models has been less successful. One recognized cause for these difficulties is the high frequency of alloreactive memory T cells (Tmem) found in the (pre)clinical setting as opposed to laboratory mice. In the present study, we therefore developed a murine bone marrow transplantation (BMT) model employing recipients harboring polyclonal donor‐reactive Tmem without concomitant humoral sensitization. This model was then used to identify strategies to overcome this additional immune barrier. We found that B6 recipients that were enriched with 3 × 10⁷ T cells isolated from B6 mice that had been previously grafted with Balb/c skin, rejected Balb/c BM despite costimulation blockade with anti‐CD40L and CTLA4Ig (while recipients not enriched developed chimerism). Adjunctive short‐term treatment of sensitized BMT recipients with rapamycin or anti‐LFA‐1 mAb was demonstrated to be effective in controlling Tmem in this model, leading to long‐term mixed chimerism and donor‐specific tolerance. Thus, rapamycin and anti‐LFA‐1 mAb are effective in overcoming the potent barrier that donor‐reactive Tmem pose to the induction of mixed chimerism and tolerance despite costimulation blockade.     

Role of mammalian target of rapamycin inhibitor in the treatment of metastatic epithelioid angiomyolipoma: A case report

Epithelioid angiomyolipoma has malignant potential; however, no effective therapy has been established for advanced cases. A 50‐year‐old woman with a history of right nephrectomy for epithelioid angiomyolipoma was referred to our institution. Computed tomography and magnetic resonance imaging showed multiple tumors in her lung, liver and pelvic cavity. The liver and pelvic tumor specimens obtained by needle biopsy confirmed the diagnosis of epithelioid angiomyolipoma recurrence. The patient was treated with everolimus (10 mg/day). Three months later, pulmonary lesions disappeared; liver and pelvic tumors significantly shrank in size, but the pelvic tumor gradually enlarged again. We carried out surgical resection of the residual liver and pelvic cavity tumors. Although the mammalian target of rapamycin inhibitor seems to be effective for treating epithelioid angiomyolipoma, its long‐term effects remain unknown. Thus, aggressive administration of a multidisciplinary treatment including molecular target therapy and surgical resection is required to improve the prognosis of epithelioid angiomyolipoma.     

Somatostatin receptors: From signaling to clinical practice

Somatostatin is a peptide with a potent and broad antisecretory action, which makes it an invaluable drug target for the pharmacological management of pituitary adenomas and neuroendocrine tumors. Somatostatin receptors (SSTR1, 2A and B, 3, 4 and 5) belong to the G protein coupled receptor family and have a wide expression pattern in both normal tissues and solid tumors. Investigating the function of each SSTR in several tumor types has provided a wealth of information about the common but also distinct signaling cascades that suppress tumor cell proliferation, survival and angiogenesis. This provided the rationale for developing multireceptor-targeted somatostatin analogs and combination therapies with signaling-targeted agents such as inhibitors of the mammalian (or mechanistic) target of rapamycin (mTOR). The ability of SSTR to internalize and the development of rabiolabeled somatostatin analogs have improved the diagnosis and treatment of neuroendocrine tumors.     

Eight‐year results of the Spiesser study,a randomized trial comparing de novo sirolimus and cyclosporine in renal transplantation

We present the results at 8 years of the Spiesser study, a randomized trial comparing de novo sirolimus and cyclosporine in kidney transplant recipients at low immunologic risk. We assessed estimated glomerular filtration (eGFR), graft, patient, and death‐censored graft survival (log‐rank compared), de novo DSA appearance, risk of malignancy, post‐transplant diabetes mellitus (PTDM), and anemia. Intent‐to‐treat and on‐treatment analyses were performed. Graft survival was similar in both groups (sirolimus: 73.3%, cyclosporine: 77.7, P = 0.574). No difference was observed between treatment groups concerning patient survival (P = 0.508) and death‐censored graft survival (P = 0.858). In conditional intent‐to‐treat analysis, mean eGFR was greater in sirolimus than in cyclosporine group (62.5 ± 27.3 ml/min vs. 47.8 ± 17.1 ml/min, P = 0.004), in particular because graft function was excellent in patients maintained under sirolimus (eGFR = 74.0 ml/min). Importantly, no detrimental impact was observed in patients in whom sirolimus has been withdrawn (eGFR = 49.5 ml/min). Overall, 17 patients showed de novo DSAs, with no difference between the two groups (P = 0.520). Malignancy did not differ by treatment. An initial maintenance regimen based on sirolimus provides a long‐term improvement in renal function for kidney transplant patients, especially for those maintained on sirolimus.     

针刺对缺氧缺血性脑病模型大鼠哺乳动物雷帕霉素靶蛋白的干预研究

目的：观察针刺对缺氧缺血性脑病模型大鼠哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)的干预作用。方法7日龄 SD 大鼠按区组随机法随机分为6组。假手术组：分离双侧颈总动脉不结扎,不做低氧处理;模型组：分离双侧颈总动脉并结扎,置于低氧气体中,不行干预;假针刺组：缺氧缺血后进行针刺,针刺位点距“百会”、“大椎”、“曲池”、“涌泉”四穴旁开1 cm 处;针刺组：缺氧缺血后第2天针刺“百会”、“大椎”、“曲池”、“涌泉”四穴;拮抗剂组：缺氧缺血后幼鼠左侧脑室注射渥曼青霉素5μl,不行干预;针刺加拮抗剂组：缺氧缺血后幼鼠左侧脑室注射渥曼青霉素5μl,其他方面同针刺组。每组又分为1 d、3 d、7 d、21 d 四个亚组,观察大鼠缺氧缺血侧脑组织的形态学变化,RT-PCR 方法检测 mTOR mRNA 的表达。结果病理结果显示,21 d 时针刺组神经细胞肿胀变轻,排列有序,可见胶质细胞增生,细胞轮廓及核仁较清晰。与模型组比较,针刺组1 d、3 d、7 d、21 d mTOR mRNA 均表达增加,差异有统计学意义(Q 值分别为7.0991,9.0099,7.8940,9.9147,P ﹤0.05)。针刺加拮抗剂组中,1 d、3 d、7 d 时 mTOR mRNA 的表达与假手术组比较,差异有统计学意义(Q 值分别为9.8689,15.8434,21.0072,P ﹤0.05),至21 d 时,与假手术组及模型组比较差异均有统计学意义(Q =18.2360,Q =4.7297,P 均﹤0.05)。结论针刺能够促进 mTOR mRNA 的表达,对缺氧缺血性脑病大鼠发挥较好的脑保护作用。