Lysosomal integral membrane protein 2 (LIMP-2) restricts the invasion of Trypanosoma cruzi extracellular amastigotes through the activity of the lysosomal enzyme β-glucocerebrosidase

Lysosomal integral membrane protein 2 (LIMP-2, SCARB2) is directly linked to β-glucocerebrosidase enzyme (βGC) and mediates the transport of this enzyme from the Golgi complex to lysosomes. Active βGC cleaves the β-glycosidic linkages of glucosylceramide, an intermediate in the metabolism of sphingoglycolipids, generating ceramide. In this study we used mouse embryonic fibroblasts (MEFs) deficient for LIMP-2 and observed that these cells were more susceptible to infection by extracellular amastigotes of the protozoan parasite Trypanosoma cruzi when compared to wild-type (WT) fibroblasts. The absence of LIMP-2 decreases the activity of βGC measured in fibroblast extracts. Replacement of βGC enzyme in LIMP-2 deficient fibroblasts restores the infectivity indices to those of WT cells in T. cruzi invasion assays. Considering the participation of βGC in the production of host cell ceramide, we propose that T. cruzi extracellular amastigotes are more invasive to cells deficient in this membrane component. These results contribute to our understanding of the role of host cell lysosomal components in T. cruzi invasion.     

Piperine ameliorates the severity of cerulein-induced acute pancreatitis by inhibiting the activation of mitogen activated protein kinases

Piperine is a phenolic component of black pepper (Piper nigrum) and long pepper (Piper longum), fruits used in traditional Asian medicine. Our previous study showed that piperine inhibits lipopolysaccharide-induced inflammatory responses. In this study, we investigated whether piperine reduces the severity of cerulein-induced acute pancreatitis (AP). Administration of piperine reduced histologic damage and myeloperoxidase (MPO) activity in the pancreas and ameliorated many of the examined laboratory parameters, including the pancreatic weight (PW) to body weight (BW) ratio, as well as serum levels of amylase and lipase and trypsin activity. Furthermore, piperine pretreatment reduced the production of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 during cerulein-induced AP. In accordance with in vivo results, piperine reduced cell death, amylase and lipase activity, and cytokine production in isolated cerulein-treated pancreatic acinar cells. In addition, piperine inhibited the activation of mitogen-activated protein kinases (MAPKs). These findings suggest that the anti-inflammatory effect of piperine in cerulein-induced AP is mediated by inhibiting the activation of MAPKs. Thus, piperine may have a protective effect against AP.     

沉默MAPK1对牛磺胆酸钠诱导的胰腺腺泡细胞内胰蛋白酶原的细胞内激活及自噬流的影响

目的:探讨沉默丝裂素活化蛋白激酶(MAPK1)对牛磺胆酸钠诱导的胰腺腺泡细胞内胰蛋白酶原激活及自噬流的影响。方法:选择体外培养的AR42J细胞分为AR42J细胞+空白对照组,AR42J细胞+牛磺胆酸钠(TLC)(200μM的TLC作用40 min),AR42J细胞+RNA1(MAPK1)。分别转染MAPK1 si RNA以及阴性对照,采用BZi PAR、流式细胞术及激光共聚焦显微镜检测胰蛋白酶原激活,western blot技术检测各组自噬相关蛋白LC3、Beclin1、Cathepsin L,组织蛋白酶L(Cathepsin L,CTSL,也称为CTSL1)和溶酶体膜蛋白(Lysosomal associated membrane protein 2,LAMP2)。结果:TLC处理AR42J细胞后,胰蛋白酶原激活显著增加(阳性细胞相对比:15.12%±1.46%vs.7.82%±1.86%,P0.05,平均荧光强度:7.65±0.72 vs.3.76±0.57,P0.05),MAPK1 si RNA转染后TLC处理AR42J细胞后细胞内胰蛋白酶原激活则较TLC组明显降低(阳性细胞相对比:9.25%±1.16%vs.15.12%±1.46%,P0.05,平均荧光强度:4.31±0.27 vs.7.65±0.72,P0.05)。TLC组Beclin1与LC3表达显著性高于对照组(Beclin1:2.237±0.097 vs.1.103±0.057,P0.05。LC3:1.908±0.039 vs.0.973±0.081,P0.05),TLC+MAPK1si RNA组Beclin1与LC3的表达显著低于TLC组(Beclin1:1.214±0.049 vs.2.237±0.097,P0.05。LC3:1.315±0.037 vs.1.908±0.039,P0.05);而TLC组LAMP2及CTSL1表达较对照组显著下调(LAMP2:0.462±0.025 vs.1.009±0.039,P0.05。CTSL1:0.563±0.028 vs.1.135±0.041,P0.05),TLC+MAPK1si RNA组LAMP2及CTSL1表达显著高于TLC组(LAMP2:1.007±0.019 vs.0.462±0.025,P0.05。CTSL1:0.921±0.030 vs.0.563±0.028,P0.05)。结论:沉默MAPK1对TLC诱导的AR42J细胞中的胰蛋白酶原激活具有抑制作用,可能通过抑制MAPK1通路抑制自噬发生,同时使LAMP2及CTSL1的表达增强,自噬溶酶体的功能正常,自噬过程顺利进行,从而抑制胰蛋白酶原的激活,减轻急性胰腺炎。     

胰腺外分泌细胞的适应性细胞保护作用

用5％牛磺胆酸钠-胰蛋白酶溶液作为强刺激物直接注入大鼠胰导管系统,制成急性出血坏死性胰腺炎模型。若于48h前向胰导管内预先给予0.1％、0.2％或0.4％的低浓度牛磺胆酸钠-胰蛋白酶溶液作为弱刺激物,能使随后给予的强刺激物所致的损伤大大减轻,使病鼠死亡率由对照组的100％分别降低到27％、17％和17％;血清淀粉酶浓度升高的幅度由对照组的4680U/100ml血清降低到1990、2180和2710U/100ml血清。胰腺组织学切片检查可见,病变由急性出血坏死性胰腺炎转变为轻度急性胰腺炎或向慢性胰腺炎转化。这项结果提示:预先给予弱刺激可使胰腺外分泌细胞对随后给予的强刺激产生适应性细胞保护作用,其机制尚待探索。     

A proliferative melanoma cell phenotype is responsive to RAF/MEK inhibition independent of BRAF mutation status

Oncogenic mutations within the MAPK pathway are frequent in melanoma, and targeting of MAPK signaling has yielded spectacular responses in a significant number of patients that last for several months before relapsing. We investigated the effects of two different inhibitors of MAPK signaling in proliferative and invasive melanoma cell cultures with various mutations in the MAPK pathway. Proliferative melanoma cells were more susceptible to pathway inhibition than invasive phenotype cells, irrespective of BRAF mutation status, while invasive phenotype cell response was dependent on BRAF mutation status. Critically, MAPK pathway inhibition of proliferative phenotype cells resulted in acquisition of invasive phenotype characteristics. These results show that melanoma cell phenotype is an important factor in MAPK pathway inhibition response. This suggests that while current therapeutic strategies target proliferative melanoma cells, future approaches should also account for the invasive phenotype population.     

Role of apoptosis of renal tubular cells in acute renal failure: Therapeutic implications

Acute renal failure (ARF) can be defined as a sudden loss of renal function and is a common and serious clinical problem. There are many causes of ARF but the most common cause results from injury to the renal tubular epi-thelial cells (RTECs). RTECs can be injured by schemia or by cytotoxic agents and, once injured, can die by necrosis or apotosis. In general, necrosis occurs in response to any severe injury, which leads to the biochemical collapse of the cell. Milder forms of the same types of injury cause apoptosis. At the cellular level there are fundamental differences between necrosis and apoptosis. Necrosis results from the additive effect of a number of independent biochemical events that are activated by severe depletion of cell energy stores. By contrast, apoptosis occurs via a coordinated, predictable and pre-determined pathway. These biochemical differences between apoptosis and necrosis have important therapeutic implications. Once a cell has been severely injured, necrosis is difficult to prevent. By contrast, the apoptotic pathway can potentially be modulated to maintain cell viability. The components of the apoptotic pathway that are potentially amenable to therapeutic modulation are discussed in detail in this review.     

IL-6、IL-10联合BISAP评分在重症急性胰腺炎预后评估中的作用研究

目的:探讨白细胞介素-6(IL-6)、白细胞介素-10(IL-10)联合急性胰腺炎严重程度床边指数(BISAP)评分在重症急性胰腺炎(SAP)预后评估中的作用。方法:回顾性分析2013年5月至2016年5月我院收治的131例SAP患者的临床病历资料,患者入院后24h内采用酶联免疫吸附法(ELISA)检测血清IL-6和IL-10水平,并进行BISAP评分,同时以接近IL-6、IL-10、BISAP评分中位数的自然值为界值,比较不同预后(死亡、感染、多器官功能障碍综合征(MODS)、局部并发症)的发生率。结果:死亡、MODS、感染患者血清IL-6水平、BISAP评分高于局部并发症患者,血清IL-10水平低于局部并发症患者(P0.05);死亡、MODS患者血清IL-6水平、BISAP评分高于感染患者,血清IL-10水平低于感染患者(P0.05);死亡患者血清IL-6水平、BISAP评分高于MODS患者,血清IL-10水平低于MODS患者,差异有统计学意义(P0.05)。IL-6≥65μg/L、IL-1040μg/L、BISAP评分≥3分患者死亡、MODS、感染发生率更高,差异有统计学意义(P0.05)。经Pearson积矩相关分析,IL-6、BISAP评分之间呈正相关关系(r=0.617,P0.05),IL-6、BISAP评分与IL-10之间呈负相关关系(r=-0.572、-0.611,P0.05)。结论:IL-6、IL-10、BISAP评分是评估SAP预后的重要指标,IL-6水平、BISAP评分越高、IL-10水平越低,患者预后越差,联合应用的预测价值高,临床可作为参考。     

重症急性胰腺炎患者并发感染的临床特征及相关危险因素分析

目的:分析重症急性胰腺炎(SAP)患者并发感染的临床特征及感染的相关危险因素。方法:选择我院2009年1月至2014年1月收治的SAP患者152例,所有患者入院后,根据有无发生并发感染分为感染组(n=48)和非感染组(n=105),详细记录两组临床资料,并对SAP患者并发感染的相关危险因素进行多因素回归分析。结果:152例SAP患者中有48例发生并发感染,并发感染率为31.58%,对感染组患者标本进行分析,检出病原菌58株,以肠杆菌属为主,其中阴沟肠杆菌最多,占比22.41%。经单因素及多因素回归分析显示年龄≥60岁、器官衰竭个数增加、禁食时间延长是SAP并发感染的独立危险因素(P0.05)。结论:内源性感染是SAP患者并发感染的主要原因,且临床诊治中应针对SAP并发感染的独立危险因素,及早给予必要的干预,降低SAP患者并发感染的风险。     

重症急性胰腺炎合并真菌感染的分布情况及防治

目的 探讨重症急性胰腺炎(severe acute pancreatitis,SAP)合并深部真菌感染(deep funsal infection,DFI)的特点和防治方法.方法 回顾性分析新疆维吾尔自治区人民医院2011年3月至2013年3月收治的97例SAP合并DFI患者的临床资料.结果 97例SAP合并DFI的患者中,常规治疗组和预防治疗组的死亡率分别为43.24％和21.56％,未治疗组患者全部死亡,组间两两比较差异有统计学意义(P＜0.05);其中以真菌引起的呼吸系统感染和泌尿系统感染为主,分别为35例(36.08％)和21例(21.64％);并且所感染的真菌中,以白色念珠菌和克柔假丝酵母菌居多,分别为49例(50.51％)和17例(17.52％).结论 DFI是重症急性胰腺炎的常见并发症,病死率较高,临床中应早期诊断,及时合理的抗真菌治疗.氟康唑可作为首选的抗真菌药物.     

重症急性胰腺炎的区域动脉灌注治疗研究进展*

重症急性胰腺炎以其复杂的病理生理过程,病情变化快,导致其虽然经历了非手术治疗,早期手术,手术非手术并重,个体化综合治疗等几个阶段后,其死亡率仍然高达22.7%。近年来动脉灌注越来越多地运用于重症急性胰腺炎,为了临床更好地把动脉灌注运用于重症急性胰腺炎,查阅国内外近年来区域动脉灌注治疗胰腺炎的文章,了解动脉灌注治疗重症急性胰腺炎的适应症、时机以及常用药物的选择,为动脉灌注寻找更好的给药时机提供一定的依据。     

SPECIFIC CHANGES IN THE PANCREACTIC EXPRESSION OF THE INTERLEUKIN 1 FAMILY OF GENES DURING EXPERIMENTAL ACUTE PANCREATITIS

Interleukin 1β (IL-1β) is produced in large amounts during acute pancreatitis and is believed to play a primary role in determining pancreatitis severity and the degree of pancreatic tissue destruction. This study was undertaken to characterize intrapancreatic production of IL-1β and the remainder of the IL-1 family of genes during sterile acute pancreatitis. Moderate or severe necrotizing pancreatitis was induced by the intraperitoneal injection of a cholecystokinin analogue or the feeding of a choline deficient diet, respectively. Animals were killed during the progression of pancreatitis with severity scored by histological grading and serum amylase concentration. The expression of IL-1β, IL-1 Receptor 1 (IL-1R1), Il-1R2, IL-1R antagonist (IL-1Ra), and ICE mRNA within the pancreas was examined by quantitative differential RT-PCR. Corresponding intrapancreatic and serum proteins were measured by enzyme-linked immunosorbent assay (ELISA). There was constitutive expression of pancreatic IL-1R1, IL-1R2, IL-1Ra, and ICE but not IL-1β. As pancreatitis developed, mRNA for IL-1β, IL-1Ra, and ICE increased in parallel with the degree of pancreatitis severity (allP<0.001 vs baseline) while mRNA for both receptors remained stable (P=NS). Intrapancreatic and systemic IL-1β and IL-1Ra protein also increased as pancreatitis developed (bothP<0.001) with tissue levels being continuously greater than serum. This study demonstrated that sterile, endotoxin-free acute pancreatitis induces the upregulation of specific members of the IL-1 family of genes including production of large amounts of IL-1β and its receptor antagonist within the pancreatic parenchyma. These changes are indicative of pancreatitis severity and are not model dependent.     

空肠营养对重症急性胰腺炎的疗效观察

目的：探讨早期空肠营养对重症急性胰腺炎（SAP）的疗效。方法：118名重症急性胰腺炎患者随机分为EN组和TPN组．比较两组SAP病人住院时间、费用、感染率、并发症及死亡率等。结果：TPN组住院时间长,费用高,感染率、并发症及病死率高。差异具有显著性。结论：早期空肠营养支持可明显改善SAP病情,提高治疗效果。     

Adrenomedullin inhibits prostate cancer cell proliferation through a cAMP-independent autocrine mechanism

Adrenomedullin (AM) is a multifunctional peptide expressed in the normal and malignant prostate, and in prostate cancer cells. To elucidate the potential role of AM in prostate cancer, we have transfected the human AM gene into PC-3, DU 145, and LNCaP prostate cancer cells. Northern blot, Western blot, and radioimmunoassay techniques confirmed an increase in the synthesis and secretion of the 6kDa mature peptide, in the AM-transfected clones. Proliferation and cell cycle assays demonstrated that AM overexpression inhibited cell proliferation in PC-3 and LNCaP cells through a G0/G1 cell cycle arrest, but not in DU 145 cells. In vivo growth assays also confirmed that, at least in PC-3, AM produced a very significant reduction of tumor volume. In addition, the three cell lines expressed the CL/RCP/RAMP-2 receptor complex by RT-PCR, which suggests that AM peptide acts through an autocrine loop in prostate cancer cells. Although cAMP elevation is the most common pathway involved in AM signalling, stimulation of PC-3, DU 145, and LNCaP with synthetic AM did not increase intracellular cAMP. However, short-term stimulation of PC-3 cells with synthetic AM increased ERK1/2 activation. On the contrary, long-term stimulation, or AM overexpression, caused a reduction in the basal activation of ERK1/2. In summary, our results demonstrate that AM (either overexpressed or exogenously added) causes an inhibition of prostate cancer cell growth. This inhibition does not depend on changes in intracellular cAMP levels, but may be related to ERK1/2 activation.     

空肠营养对重症急性胰腺炎的疗效观察

目的:探讨早期空肠营养对重症急性胰腺炎(SAP)的疗效。方法:118名重症急性胰腺炎患者随机分为EN组和TPN组,比较两组SAP病人住院时间、费用、感染率、并发症及死亡率等。结果:TPN组住院时间长,费用高,感染率、并发症及病死率高,差异具有显著性。结论:早期空肠营养支持可明显改善SAP病情,提高治疗效果。