Rapamycin and bafilomycin A1 alter autophagy and megakaryopoiesis

Autophagy is an effective strategy for cell development by recycling cytoplasmic constituents. Genetic deletion of autophagy mediator Atg7 in hematopoietic stem cells (HSCs) can lead to failure of megakaryopoiesis and enhanced autophagy has been implicated in various hematological disorders such as immune thrombocytopenia and myelodysplastic syndrome. Here, we examined the hypothesis that optimal autophagy is essential for megakaryopoiesis and thrombopoiesis by altering autophagy using pharmacological approaches. When autophagy was induced by rapamycin or inhibited by bafilomycin A1 in fetal liver cells, we observed a significant decrease in high ploidy megakaryocytes, a reduction of CD41 and CD61 co-expressing cells, and less proplatelet or platelet formation. Additionally, reduced cell size was shown in megakaryocytes derived from rapamycin, but not bafilomycin A1-treated mouse fetal liver cells. However, when autophagy was altered in mature megakaryocytes, we observed no significant change in proplatelet formation, which was consistent with normal platelet counts, megakaryocyte numbers, and ploidy in Atg7^flox/flox PF4-Cre mice with megakaryocyte- and platelet-specific deletion of autophagy-related gene Atg7. Therefore, our findings suggest that either induction or inhibition of autophagy in the early stage of megakaryopoiesis suppresses megakaryopoiesis and thrombopoiesis.     

自噬与糖尿病骨骼肌病变

骨骼肌占人类体成分的40％～ 50％,是摄取和利用葡萄糖的重要组织,70％的葡萄糖通过胰岛素依赖的方式被骨骼肌摄取;同时骨骼肌也是2型糖尿病患者发生胰岛素抵抗的重要靶组织.现有研究发现,2型糖尿病患者骨骼肌内细胞器发生重构、外膜细胞退化及凋亡、肌膜下线粒体减少、肌细胞内脂质沉积、慢肌纤维与快肌纤维比值降低等,在临床上表现为胰岛素抵抗、骨骼肌萎缩等糖尿病骨骼肌肌病特征.糖尿病骨骼肌病变的发病机制至今不甚明确,自噬可能是主要原因之一.     

哺乳动物雷帕霉素靶蛋白介导的自噬在心血管疾病中作用的研究进展

自噬是生物进化过程中高度保守、依赖溶酶体的胞内降解途径。在心血管系统中,基础水平的自噬是维持心脏结构和功能稳态的一种机制;在应激状态下,自噬适度激活可保护心肌细胞免受应激损伤,而过度激活则会加重心肌损伤,从而参与多种心血管疾病的病理生理过程。生物体内存在多种自噬调控机制,其中哺乳动物雷帕霉素靶蛋白是自噬的关键负调控因子,研究其介导的自噬在心血管疾病中的作用机制,有助于探索临床预防和治疗心血管疾病的新靶点。     

HBV NAT positive [corrected] blood donors in the early and late stages of HBV infection: analyses of the window period and kinetics of HBV DNA

BACKGROUND AND OBJECTIVES: The Japanese Red Cross (JRC) carries out nucleic acid amplification testing (NAT) for hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus-1 (HIV-1) by using a multiplex (MPX) reagent. Screening is undertaken on serologically negative units. In this study we characterized HBV NAT-positive donations individually and analysed the window period and kinetics of HBV DNA, during acute infection, in follow-up studies. MATERIALS AND METHODS: Two hundred and seventy-seven HBV DNA-positive donations have been identified in Japan since the introduction of NAT screening of 50-donation minipools. The viral loads and genotypes of these HBV DNA-positive donations were characterized. The doubling time and half-life of HBV was estimated from the data of 123 follow-up donors. The sensitivity of the NAT system (based on 50-donation minipools) was compared with the sensitivities of the enzyme immunoassay (EIA) and the chemiluminescence immunoassay (CLIA). Samples that were CLIA negative, but with > 10(4) copies/ml of HBV DNA, were analysed by sequencing the hepatitis B surface antigen (HBsAg) region. RESULTS: Out of 277 HBV NAT-positive samples, 125 (45%) were found to have an increasing viral load and 45 (16%) a decreasing viral load. Forty per cent of HBV NAT-positive samples with an increasing viral load, and 33% of those with a decreasing viral load, were negative when tested by using the CLIA. No mutations related to escape mutants were found in the samples that were CLIA negative but with HBV DNA loads of > 10(4) copies/ml. The median HBV doubling time was 2.6 days (n = 93, 1.3-15.2 days) and the half-life was 1.6 days (n = 55, 0.9-6.3 days). Some kinetic difference was observed between genotypes A and B. CONCLUSIONS: HBV NAT screening detected HBV DNA in both early (the so-called serological window period) and late stages of acute HBV infection.     

自噬与糖尿病心脏病变

自噬是一种细胞应激和自我防御的机制,其主要生理作用是吞噬、降解变性的大分子物质及受损的细胞器,从而实现物质的再循环及细胞内环境的稳定.近年来有研究显示,自噬与糖尿病心脏病变发病有密切关系,自噬小体的生成及自噬与溶酶体解离功能紊乱在心肌细胞物质代谢紊乱、微血管病变、心肌纤维化等的发生、发展中发挥重要作用,被认为是糖尿病心脏病变发病机制之一.     

乙肝病毒感染者血清HBeAg模式与HBVDNA定量关系的研究

探讨乙肝病毒感染者血清HBeAg模式与HBV DNA定量之间的关系。采用酶联免疫技术和实时荧光定 量PCR法,分别检测随机选择的80例乙肝病毒感染者血清HBeAg模式及HBV DNA定量。结果显示,当乙肝病毒 感染者血清HBV DNA含量为A、C级时,血清HBeAg模式与HBV DNA定量之间亦无相关性(P>0．05)。当乙肝病 毒携带者血清HBV DNA含量为B级时,HBeAg阳性模式HBV DNA含量显著高于HBeAg阴性者,血清HBeAg模式 与HBV DNA定量之间有显著相关性(r=0．28,t=1．19,P<0．05)。由此可推测,只有当机体内乙型肝炎病毒水平在 一定的范围内,机体的免疫应答能力才与乙型肝炎病毒水平相呼应。     

乙型肝炎孕妇HBV血清标志物与HBVDNA载量及ALT的相关性分析

目的 分析乙型肝炎(乙肝)孕妇HBV血清标志物、HBVDNA载量及ALT检测结果,为HBV感染孕妇的诊治提供参考。方法 回顾性分析2016年11月—2017年11月在我区孕检的120例乙肝孕妇的临床资料,应用酶联免疫吸附法检测血清五项HBV标志物,同时采用荧光实时定量PCR技术检测HBVDNA水平,酶速率法检测ALT,并对检测结果进行统计分析。结果 120例孕妇血清中,感染模式Ⅰ(大三阳)HBsAg(+)、HBeAg(+)、HBcAb(+)58例,占48.33%;HBVDNA(+)49例,占84.48%,其中HBVDNA>106IU/ml42例,占72.41%;ALT增高39例,异常率为67.24%。感染模式Ⅱ(小三阳)HBsAg(+)、HBeAb(+)、HBcAb(+)45例,占37.50%;HBVDNA(+)27例,占60.00%,其中HBVDNA>106IU/ml15例,占33.33%;ALT增高20例,异常率为44.44%。感染模式Ⅰ孕妇HBVDNA阳性率、HBVDNA>106IU/ml率和ALT异常率最高,感染模式Ⅱ孕妇次之。结论 HBV血清标志物与HBVDNA高载量和ALT水平密切相关,三者相结合能为孕妇的临床诊断、围产期干预措施以及疗效观察提供参考依据。     

自噬与慢性阻塞性肺疾病

自噬现象是一个广泛存在于真核细胞中的生命过程,最早于1962年由Ashford和Porter发现的.近年来,随着对自噬作用研究的深入,发现自噬在多种疾病中都扮演着十分重要的角色.慢性阻塞性肺疾病(chronic obstructive pulmonary disease,COPD)逐渐成为一个不容忽视的公共健康问题,据世界卫生组织/世界银行研究推测,截至2020年该病将成为全球经济负担的第五大疾病.但是,COPD的发病机制尚不明确,随着自噬现象及其与COPD的关系研究进一步深入,为COPD的防治寻找新的治疗策略.因此,该文着重讨论自噬在COPD发病机制中的作用及其在COPD中的临床运用价值.     

自噬与卒中

自噬是广泛存在于真核细胞的一种生命现象,其贯穿于细胞的正常生长、发育和生理病理学过程.近年来的研究表明,自噬参与了卒中后的病理学过程,并且影响神经细胞的生存和死亡.文章对自噬的分类、形成过程、分子机制、检测及其与卒中的关系做了综述,旨在为卒中的临床治疗提供新的方向.     

Preliminary results of HBV DNA testing of Polish haemophilia patients – lack of occult HBV infection

Identification of hepatitis B virus (HBV) infection in the absence of surface antigen (HbsAg) became possible with the introduction of HBV DNA detection methods. Such occult HBV infection was diagnosed recently in about half of the Japanese HBsAg-negative haemophilia patients. The aim of our study was to assess the prevalence of occult HBV infection in Polish severe haemophilia population on the sample of 115 haemophilia A and B patients (mean age 34.9 +/- 10.9) treated with non-virus inactivated clotting factor preparations before 1995. HBV DNA was detected in nine HBsAg-positive patients (7.8%). The mean HBV DNA load was 72,800 IU mL(-1) (250-400,000 IU mL(-1)). Hepatitis C virus (HCV) RNA was found in six out of nine HBV-positive patients. In conclusion, HBV DNA was identified only in HBsAg-positive patients. Unlike in Japan, the frequency of occult HBV infection in Polish haemophilia population seems extremely rare or absent.     

自噬与肝脏脂代谢

细胞自噬是利用溶酶体降解受损的细胞器、未折叠蛋白来维持细胞内稳态,在机体生长、发育和衰老中均起重要作用.研究表明,自噬可能与肝脏脂肪合成及分解相关.固醇调节元件结合蛋白通路、转录因子、激素与营养因素可能会影响自噬,从而改变脂代谢.     

慢性乙型肝炎血清标志物少见模式分析

HBV感染后血清标志物的模式表现呈多样化。本科血清免疫室2004年共检测到42例少见模式，占阳性总例数的0．6％（42／6744）。其中HBsAg（-）、抗HBs（-）、HBeAg（＋）、抗HBe（-）、抗HBc（＋）者33例，HBsAg（＋）、抗HBs（-）、HBeAg（＋）、抗HBe（＋）、抗HBc（＋）者9例。更换不同厂家试剂检得相同结果。HBVDNA．PCR检测42例均呈阳性。笔者分别对上述2种少见模式的HBsAg（-）（P／N0．1～2．0）和抗HBe（＋）（抑制率0．6～0．8））作进一步检测分析。     

Evidence that anti-HBc but not HBV DNA testing may prevent some HBV transmission by transfusion

Blood donor screening for antibody to hepatitis B core antigen (anti-HBc) implemented in some countries as a surrogate marker for non-A, non-B hepatitis has been superseded by anti-HCV screening. To assess the value of anti-HBc screening for the detection of hepatitis B surface antigen-negative blood donations that might contain infectious HBV, HBV genomic detection and recipient testing were used. Blood donations were screened and confirmed by multiple anti-HBc assays. Donations containing isolated anti-HBc and those with anti-hepatitis B surface antigen (anti-HBs) level < 0.1 IU/ml were tested for the presence of HBV DNA. Recipients of previous donations from the corresponding donors during the previous 5 years were traced and tested for markers of HBV infection. Of 103 869 donations screened, 586 (0.56%) were anti-HBc positive, two of which contained HBsAg, and 413 (0.4%) had protective (>/= 0.1 IU/ml) levels of anti-HBs. Anti-HBs < 0.1 IU/ml was found in 102 of these donations (0.1%) and isolated anti-HBc in 69 (0.07%). No donations with isolated anti-HBc were HBV DNA confirmed positive. Of 278 recipients of previous donations from 171 donors at risk of HBV carriage, 12 had markers of HBV infection. Six recipients had other identified risk factors. An association with blood transfusion was considered probable in two and possible in four recipients. None of the six corresponding donors had detectable HBV DNA 6-40 months after the implicated donation. The frequency of HBV transmission by chronic carriers negative for hepatitis B surface antigen was estimated in this study to be 1 in 52,000 donations (CI 0.3-7.8/100,000) from HBsAg-negative donors. Such HBV infectious donations may not be detected by DNA amplification.     

Icaritin Attenuates Lipid Accumulation by Increasing Energy Expenditure and Autophagy Regulated by Phosphorylating AMPK

Background and AimsLipid accumulation is the major characteristic of non-alcoholic fatty liver disease, the prevalence of which continues to rise. We aimed to investigate the effects and mechanisms of icaritin on lipid accumulation.MethodsCells were treated with icaritin at 0.7, 2.2, 6.7, or 20 µM for 24 h. The effects on lipid accumulation in L02 and Huh-7 cells were detected by Bodipy and oil red O staining, respectively. Mitochondria biogenesis of L02 cells was detected by MitoTracker Orange staining. Glucose uptake and adenosine triphosphate content of 3T3-L1 adipocytes and C2C12 myotubes were detected. The expression levels of proteins in the adenosine 5′-monophosphate-activated protein kinase (AMPK) signaling pathway, biomarkers of autophagy, and mitochondria biogenesis were measured by western blotting. LC3 puncta were detected by immunofluorescence.ResultsIcaritin significantly attenuated lipid accumulation in L02 and Huh-7 cells and boosted the mitochondria biogenesis of L02 cells. Icaritin enhanced glucose uptake, decreased adenosine triphosphate content, and activated the AMPK signaling pathway in 3T3-L1 adipocytes and C2C12 myotubes. Icaritin boosted autophagy and also enhanced the initiation of autophagic flux in 3T3-L1 preadipocytes and C2C12 myoblasts. However, icaritin decreased autophagy and promoted mitochondria biogenesis in 3T3-L1 adipocytes and C2C12 myotubes.ConclusionsIcaritin attenuates lipid accumulation by increasing energy expenditure and regulating autophagy by activating the AMPK pathway.     

慢性乙型肝炎患者外周血单个核细胞内HBV RNA、HBV DNA的检测及其与血清HBV DNA的关系

目的:探讨慢性乙型肝炎(慢乙肝)患者外周血单个核细胞(PBMC)中HBV感染情况及复制状态,以及与血清HBV DNA的关系.方法:应用PCR技术特异性,选择地检测慢乙肝患者PBMC中HBV RNA、HBV DNA,并与血清HBV DNA进行比较.结果:在慢乙肝患者PBMC中能检测出HBV RNA及HBV DNA,阳性率分别为38.78%及77.55%,且两者的检出率有一致性.当PBMC中HBV RNA阳性时,HBV DNA均为阳性(100%),而当HBV DNA阳性时,部分病例可表现为HBV RNA阴性,两者阳性符合率为50%.血清中HBV DNA阳性率为71.42%.PBMC中HBV RNA的阳性率与血清中HBV DNA的阳性符合率为63.33%,血清中HBV DNA与PBMC中HBV DNA阳性符合率为76.32%.结果提示:HBV能感染PBMC,在部分患者存在着活动性复制,这种复制表现为不同于肝细胞内的低水平复制.此外,HBV感染PBMC后也存在着非复制状态,表现为PBMC中HBV DNA阳性,但HBV RNA阴性.另外,当血中HBV DNA阴性时,少数病例PBMC仍可表现为HBV RNA及HBV DNA阳性.结论:HBV能够感染PBMC并存在活动性复制,可能是造成患者免疫功能紊乱、肝脏损害慢性化的重要原因之一.     

雷帕霉素对1型糖尿病小鼠免疫功能的影响及其分子机制

目的研究雷帕霉素对1型糖尿病（T1DM）小鼠的影响及其分子机制。方法40mg／kg的STZ腹腔注射C57BL／6小鼠连续5d建立T1DM模型,正常和T1DM小鼠按2mg／kg腹腔注射RAPA连续两周。监测血糖、体重、进食量和饮水量;观测胰岛炎、主要脏器的超微结构和凋亡和自噬的发生;检测脾脏Th1／Th2分群和调节性T细胞。结果RAPA对正常小鼠一般特性及主要脏器的超微结构无明显影响。但可使T1DM小鼠血糖升高、体重下降、采食和饮水量增加（P〈0．05）,并加重其胰岛炎程度;诱导其胰腺、肾脏、脾脏和胸腺细胞自噬或凋亡,并使LC3、Beclin1、Caspase-3的表达增加;减少正常和T1DM小鼠的Th1细胞,增加Th2细胞,并上调CD4^＋CD25%＋T细胞的数量。结论RAPA既可诱导免疫耐受,发挥免疫抑制作用,又可通过自噬直接破坏胰岛从而加重T1DM代谢紊乱和并发症。     

Hepatic lesions in alcoholic HBV carriers

Liver biopsies were taken from 54 alcoholic HBV carriers with liver dysfunction to assess whether HBV infection or habitual drinking was the main cause of their illness. In 28 cases, ultrastructural studies were done. Results showed that 50% of the cases predominantly displayed virus-related histological changes, whereas 13% of them mainly had alcohol-related ones. Both pathological changes were evenly distributed in four cases. The remaining 15 cases showed nonspecific or other histological changes. Electron microscopy revealed that HBV core and Dane particles were seen with Mallory bodies in the same hepatocytes. Thus, we postulate that HBV-related changes are more often encountered than alcoholic ones in alcoholic HBV carriers and that HBV replication can occur even in hepatocytes bearing Mallory bodies.     

高龄冠心病患者应用雷帕霉素洗脱支架研究

目的探讨雷帕霉素洗脱支架在高龄冠心病患者中应用的安全性和有效性。方法2003年3月至2006年2月间共80例冠心病患者接受雷帕霉素洗脱支架治疗(包括进口Cypher支架和国产Firebird支架),按年龄分为高龄组(≥70岁)51例,对照组(<60岁)29例。记录并比较两组基本临床情况、冠状动脉造影与介入治疗情况和术后临床疗效及随访结果。结果两组患者除了年龄外,其他基本临床特征无显著差异;造影结果显示高龄组多支血管病变比例大于对照组;支架手术时高龄组在靶病变严重程度、平均手术血管支数、支架个数、支架总长度均高于对照组,完全血运重建比例低于对照组;两组直接支架术比例分别为7.84%和27.59%(P<0.05),需后扩张修饰分别为43.14%和20.69%(P<0.05);术后18.9±8.5个月临床随访,两组心绞痛复发率分别为25.49%和6.90%(P<0.05),严重心脏不良事件发生率分别为13.73%和6.70%(P>0.05)。结论雷帕霉素洗脱支架在高龄冠心病患者中应用是安全有效的,但术后随访心绞痛复发率较高。     

雷帕霉素药物洗脱支架对糖尿病小型猪冠状动脉支架置入后内膜增生的影响

目的:评估雷帕霉素药物洗脱支架(SES)对糖尿病小型猪冠状动脉支架置入后内膜增生的作用.方法:建立链脲菌素诱导的糖尿病小型猪模型(糖尿病组,n=12),随机选取2支冠状动脉置入SES,共计置入24枚支架,术后饲养6个月,与非糖尿病置入SES支架的小型猪模型(对照组,n=12)比较冠状动脉造影、血管内超声及组织切片检查结果.结果:两组动物支架置入冠状动脉分布,术前参照血管直径[糖尿病组:(2.78±0.35)mm,对照组:(2.81±0.29)mm]及术后即刻最小管腔内径[糖尿病组:(2.90±0.42)mm,对照组:(2.89±0.33)mm]均相似(P均>0.05).术后6个月糖尿病组支架内狭窄程度[(35.6±9.2)%和(7.9±3.1)%,P<0.001]、支架内晚期管腔丢失[(0.32±0.09)mm和(0.09±0.04)mm,P<0.001]、新生内膜厚度[血管内超声:(0.35±0.12)mm和(0.11±0.08)mm,P<0.05]及新生内膜面积[血管内超声:(1.29±0.51)mm~2和(0.26±0.11)mm~2,P<0.001;组织切片:(1.24±0.76)mm~2和(0.19±0.08)mm~2,P<0.05]均显著高于对照组.结论:糖尿病小型猪冠状动脉置入SES后内膜增生程度显著高于无糖尿病模型.