铁调素(Hepcidin)对细胞铁代谢影响的研究进展

Hepcidin是一种肝脏分泌的富含半胱氨酸的新型抗菌多肽,具有抗细菌和真菌等抗菌肽的特性.近几年的研究证实,Hepcidin在机体铁代谢平衡的调节中起关键作用,因而被人们称为铁调节激素.Hepcidin自肝细胞中合成之后分泌至血液,将体内铁调节的信号传至十二指肠细胞、巨噬细胞、脑细胞、心肌细胞等,通过影响铁转运相关蛋白的表达水平,进而调节机体铁的吸收、储存和转运.     

黄瓜香水提物对自由基损伤心肌细胞的作用

目的观察黄瓜香水提物对自由基损伤的心肌细胞的作用.方法体外培养心肌细胞,以不同浓度的黄瓜香水提物进行干预,测定心肌细胞搏动频率及培养液中乳酸脱氢酶(LDH)的活性,采用MTT法观察黄瓜香水提物对心肌细胞存活率的影响.结果自由基对心肌细胞造成损伤,不同浓度的黄瓜香水提物可减少LDH漏出,增加细胞存活率(P<0.05).结论黄瓜香对自由基损伤的心肌细胞具有保护作用.     

替米沙坦对血管紧张素Ⅱ诱导的心肌细胞肥大及p-ERK1/2的调节作用

观察替米沙坦(Telmisartan)对血管紧张素Ⅱ(Ang Ⅱ)诱导的心肌细胞肥大及p-ERK1/2表达的影响.通过培养新生大鼠心肌细胞,用相差显微镜计数心肌细胞搏动频率、细胞图像分析系统测量细胞体积、考马斯亮蓝法测定心肌细胞总蛋白含量、[3H]-亮氨酸掺入法测定蛋白合成速率作为心肌肥大指标;以ERK免疫沉淀活性试剂盒测定ERK活性;用Western-blot测定p-ERK1/2表达.实验结果显示Telmisartan能显著降低Ang Ⅱ诱导的心肌细胞搏动频率、体积、总蛋白含量、蛋白合成速率上升,同时对p-ERK1/2表达具有剂量、时间依赖性抑制作用.因此考虑Telmisartan可以抑制Ang Ⅱ诱导的心肌细胞肥大,其机制与抑制p-ERK1/2表达有关.     

膜铁转运辅助蛋白研究进展

膜铁转运辅助蛋白（Hp） 是研究性连锁遗传贫血（sla）小鼠时发现的一种新的铁转运相关蛋白．它与铜蓝蛋白（Cp）属同一家族．与Cp不同， Hp是具有一个跨膜结构的完整膜蛋白，主要存在于小肠绒毛的上皮细胞．作为亚铁氧化酶，Hp在铁从肠上皮细胞转运到血液的过程是必需的，该基因突变将造成机体严重的铁缺乏．脑内Hp的发现，为脑铁稳态的调控机制提供了新的认识．文中综述了Hp的发现、结构、表达、调控及其在脑铁代谢中的作用．     

基于Nrf2/HO-1信号通路探讨补阳还五汤对AngⅡ诱导的H9c2细胞铁死亡的保护作用

目的 基于Nrf2/HO-1铁死亡信号通路探讨补阳还五汤对血管紧张素Ⅱ（AngiotensinⅡ，AngⅡ）诱导的H9c2大鼠心肌细胞铁死亡的影响。 方法 体外培养H9c2心肌细胞，分别设正常组（ZC）、模型组（MX）、补阳还五汤低剂量组（BD）、补阳还五汤中剂量组（BZ）、补阳还五汤高剂量组（BG）和阳性对照组（YX）。除正常组外，其余各组采用1μM血管紧张素Ⅱ（AngⅡ）建立心肌细胞损伤模型，同时补阳还五汤低、中、高剂量组分别用含0.5mg/mL、1mg/mL、2mg/mL补阳还五汤的培养基培养，阳性对照组使用含10μM铁死亡抑制剂Ferrostatin-1（Fer-1）的培养基培养，24h后收集细胞。采用CCK-8法检测各组心肌细胞活性；细胞铁含量检测试剂盒测定细胞内铁含量；免疫荧光染色法检测各组Nrf2蛋白表达；q-PCR法检测各组细胞核转录相关因子2（Nrf2）、血红加氧酶-1（HO-1）、谷胱甘肽过氧化物酶4（GPX4）的mRNA表达水平；ELISA试剂盒检测细胞谷胱甘肽（GSH）和GPX4的蛋白表达水平；Western blot法检测Nrf2和HO-1的蛋白表达。结果 补阳还五汤高剂量组可明显提高AngⅡ诱导的H9c2细胞活力下降，减少AngⅡ条件下铁含量（P﹤0.05）；与模型组相比，补阳还五汤高剂量组能显著逆转AngⅡ诱导的H9c2细胞GSH、GPX4、Nrf2和HO-1的基因和蛋白表达水平的下降，使AngⅡ条件下受到抑制的Nrf2表达增加，与阳性对照组结果一致。结论 补阳还五汤可能通过Nrf2/HO-1信号通路调控心肌细胞铁死亡从而保护高血压继发的心肌损伤。     

小肠微血管内皮细胞铁转运相关蛋白的发现

选用未离乳的SD大鼠十二指肠,采用2次酶消化及不同孔径滤网分级过滤等方法分离十二指肠微血管,通过体外培养、纯化成功获得了高纯度的原代培养的小肠微血管内皮细胞,并应用Western-blot技术,首次检测到了小肠微血管内皮细胞具有铁转运相关蛋白DMT1(divalent metal transporter1),FPN1(feerroportin1)和Tfr1的表达.这一新发现极大地丰富了小肠铁吸收及小肠铁吸收调节机制的理论,对进一步开展小肠铁代谢及其调节机制和铁代谢疾病的研究具有重要的理论和应用价值.     

灵芝免疫调节蛋白LZ-8及云芝免疫调节蛋白FIP-tvc对几种癌细胞系的抑制活性检测

在体外培养的人非小细胞肺癌A549细胞、人胃腺癌BGC-823细胞、人结肠癌HCT116细胞、人肝癌Hep 3B细胞、人宫颈癌Hela细胞中加入不同浓度的酵母异源表达的LZ-8或FIP-tvc,培养24 h后显微镜下观察细胞形态变化,并用CCK8试剂盒检测细胞存活率,以用来检测灵芝免疫调节蛋白LZ-8及云芝免疫调节蛋白FIP-tvc对几种癌细胞生长抑制能力.结果显示,LZ-8和FIP-tvc在5～10μg/mL浓度时使A549、BGC-823、Hela和Hep 3B细胞贴壁性变差,且CCK8结果显示前3种细胞的存活率有不同程度的降低(80%～95%存活率),而在20μg/mL浓度时FIP-tvc对Hep 3B细胞的存活率开始有明显抑制效果(89%存活率),但对HCT 116细胞的形态无影响,对其存活率也无抑制作用.     

小肠粘膜细胞铁吸收机制

缺铁性贫血和运动性低铁状态在运动员中发生率高于一般人群，运动员补铁效果不理想。寻求有效的补铁措施的关键问题是要阐明小肠粘膜上皮细胞究竟如何吸收铁，然而有关铁吸收的机制一直不清楚。近几年研究发现小肠粘膜上皮细胞存在DMT1、Dcytb、Fp1和Hp等铁转运蛋白TfR-1和TfR-2在隐窝细胞和绒毛细胞基底侧膜具有相对特异性分布。本根据这些发现以及对其转运机制、转运特性和调节机制的研究进展勾画出小肠粘膜上皮细胞铁吸收过程和调节机制模型。     

内脂素对心肌细胞ICAM-1和VCAM-1及相关因子的影响

为阐明内脂素(Visfatin)在心肌细胞炎性反应中对黏附分子ICAM-1和VCAM-1表达的影响及分子机制,利用原代培养心肌细胞在脂多糖(LPS)刺激发生炎性反应的基础上,检测了Visfatin对ICAM-1和VCAM-1表达的影响,并进一步检测了Visfatin对NF-κB以及NF-κB抑制蛋白Ⅰ-κB及磷酸化的影响.结果表明:Visfatin对LPS诱导的原代心肌细胞炎性因子ICAM-1和VCAM-1的表达具有显著的促进作用,而这一过程是通过促进Ⅰ-κB的磷酸化,增加NF-κB p65的核转移,启动下游的黏附分子mRNA转录和蛋白的表达实现的.     

CP1抗菌蛋白对出芽短梗霉内容物泄露及呼吸作用的影响

通过对CP1抗菌蛋白作用下出芽短梗霉胞内蛋白质及离子的泄漏进行研究表明,CP1抗菌蛋白引起菌丝和孢子蛋白质的泄漏较明显,CP1抗菌蛋白可直接引起菌丝体和孢子的外壁穿孔、破裂,胞内物质泄漏;CP1抗菌蛋白还能引起菌丝和孢子内Ca2+的泄漏,说明该抗菌蛋白能作用于出芽短梗霉菌丝体和孢子外膜,形成离子通道,使Ca2+从菌体细胞中释放出来.CP1抗菌蛋白对出芽短梗霉菌丝体和孢子的氧呼吸有明显的抑制作用,随着CP1抗菌蛋白浓度的增加,其耗氧百分率减少,呼吸作用从起始到停止经历的时间缩短.表明CP1抗菌蛋白对出芽短梗霉菌丝体和孢子氧呼吸的抑制作用是其活性作用的一个重要原因.     

新生大鼠心肌细胞原代培养方法的改进

探讨更为简单的SD大鼠心肌细胞原代培养的方法,使分离的心肌细胞达到理想的存活率和纯度,为临床应用建立心肌细胞模型.取出生24 h内SD大鼠的左心室,剪碎、消化、分离和纯化,进行培养,0.1 g/L胰酶消化,可以分离到形态完整、贴壁生长的心肌细胞.进一步通过离心、差速贴壁和化学试剂抑制非心肌细胞生长,纯化得到95%以上的心肌细胞.成功建立了心肌细胞体外培养模型,获得了高纯度的心肌细胞.     

Regulations of thyroid hormone on cardiac protein kinase C signal pathway in vitro

The experiments were conducted to assess the influences of thyroid hormone on cardiac protein kinase C(PKC) signal pathway with cultured cardiac myocytes and fibroblasts as the models. Cells were pretreated with 1% newborn calf serum (NCS) or angiotensin II (Ang II), and then following by a triiodothyronine (T3) treatment. The PKC activity, PKC_α and PKC_ε expressions were analyzed and compared. In 1% NCS pretreatment, T3 could inhibit PKC activity and PKC_ε expression in cardiac myocytes. The AngII pretreatment led to an increase of PKC activity and PKC_ε expression in cardiac myocytes, and an increase of PKC activity in cardiac fibroblasts. Following by T3 treatment, the increased PKC activity and PKC_ε expression in cardiac myocytes were markedly decreased. In conclusion, whether in 1% NCS or in Ang II pretreatment, T3 could inhibit PKC activity and PKC_ε expression in cardiac myocytes. Foundation item: Supported by the Natural Science Foundation of Hubei Province (98091) Biography: WANG Bao-hua (1974-), female, Ph. D, research direction: cardiovascular pathophysiology.     

含晶界孔洞粗晶工业纯铁的循环变形及损伤特征

为了更好地了解体心立方(bcc)结构金属的循环变形机制,在恒总应变幅控制的条件下研究了含晶界孔洞粗晶工业纯铁的疲劳变形特征.结果表明,含晶界孔洞的粗晶工业纯铁在不同总应变幅"εt/2下均发生不同程度的循环硬化现象,无循环饱和阶段出现.疲劳寿命与塑性应变幅的关系基本符合Coffin-Manson法则.循环变形的表面变形特征与外加总应变幅具有一定的相关性:随着总应变幅的增加,滑移变形及其导致的挤出侵入现象更为严重,滑移开裂更趋显著;越来越多的原来位于晶界上的微观孔洞发生扭曲变形、聚合、长大而产生裂纹,甚至导致沿晶开裂.在相对较高的总应变幅下,在表面还观察到了滑移扭折现象以及沿晶裂纹扩展进入晶粒内部的现象.在低应变幅"εt/2=1.0×10-3下循环变形后发现了类驻留滑移带(PSB)楼梯位错结构,随着应变幅的增加,位错胞结构发展成为主要结构特征,其平均尺寸逐渐减小.     

枣仁皂甙A对海马神经细胞的影响

在实验室建立了体外培养新生大鼠海马神经细胞方法，观察和研究枣仁皂甙A（JuA）对海马神经细胞生长的影响，用免疫组化和免疫荧光法鉴定神经细胞，M1rr检测神经细胞存活率。试验结果表明，培养细胞为高纯度的海马神经细胞，JuA组的海马神经细胞存活率明显高于对照组（p〈0．01），且呈现一定剂量相关性，提示JuA对体外培养的新生大鼠海马神经细胞的生长有一定的促进作用     

单纯缺铁性贫血住院患者心率变异的研究

目的研究单纯缺铁性贫血住院患者心率变异。方法选取23名单纯缺铁性贫血患者为试验组,16名健康人为对照组,住院期间限制体力活动,并记录24小时动态心电图。结果试验组心率均值为（84．5±22．4）次／min显著高于对照组（72．6±13．2）次／min（P=0．005）。心率变异参数两组问均无显著性差异。结论体力活动受限的缺铁性贫血患者,心率变异没有显著性改变。     

Gene Product Expression of Cyclin D2 and p16 During the Transition from Cardiac Myocyte Hyperplasia to Hypertrophy

The current study was to investigate mRNA expression of cyclin D2 and p16 during the transition from cardiac myocyte hyperplasia to hypertrophy. Cultured cardiac myocytes (CM) and fibroblasts (FC) obtained from 1-day-old Sparague-Dawley rats were used in this study. We have determined (1) hyperplasia by cell growth curve and fluorescence activated cell sorting (FACS); and (2) ultrastructure by electron microscope observation; and (3) expressions of cyclin D2 mRNA and p16 mRNA by using in situ hybridization and image analysis. The results were shown (1) Results of cell growth curve and FACS analysis showed CM could proliferate in the first 3 cultured days (4 days in postnatal development). But the ability decreased quickly, concomitant with the differentiation. (2) The ultrastructure of CM showed the large amount of myofilaments and mitochondrion and FC showed moderate amount of rough endoplasmic reticulum. (3) The expression of cyclin D2 mRNA in 3-, 4-, 5-day CM group was 0.89 times(p<0.05), 0.80 times (p<0.05)and 0.56 times (p<0.01)of that in 1-day group respectively. P16 mRNA in 2-, 3-, 4-, 5-day CM group were 1.63 times(p<0.01),1.72 times(p<0.01),1.99 times (p<0.01)and 2.84 times (p<0.01) of that in 1-day group respectively. It can be concluded that cultured neonatal rat cardiac myocytes could proliferate during the first 3 cultured days, but the ability of proliferation decreased, from the fourth day, concomitant with differentiation. Cyclin D2 and p16 have the key roles during the transition from myocyte hyperplasia to hypertrophy.     

硫铁化物自燃性的研究

储罐内壁铁的腐蚀产物之一Fe2O3与湿H2S发生反应生成不同形式的硫铁化物,硫铁化物的氧化放热是引起含硫油品储罐着火的主要原因。研究了在75℃条件下,硫化时间对Fe2O3硫化产物的生成及其自燃性的影响。通过X-射线衍射对硫化时间为6h、3d．6d以及17d条件下生成的硫铁化物成分进行了鉴定,并对3d和6d条件下的硫铁化物进行了定量分析。结果表明,在高温条件下,随着硫化时间的延长,有更多的FeS2和Fe3S4生成,并且Fe3S4不断向FeS2转化,自燃性增强,对储罐安全运行构成威胁。     

Caffeine induces a transient inward current in cultured cardiac cells

Electrical excitation of cardiac muscle may sometimes be due to initiation of inward current by the presence of Ca2+ ions at the inner surface of the cell membrane. During digitalis toxicity and other conditions that abnormally augment cellular Ca2+ stores, premature release of Ca2+ from the sarcoplasmic reticulum leads to a transient inward current, which is large enough to initiate premature beats and is accompanied by a transient contractile response. This inward current may be mediated either by electrogenic sodium-calcium exchange or by specific Ca2+-activated cation channels that have recently been characterized in tissue cultures of cardiac myocytes. An obvious question raised by these observations is whether release of the sequestered Ca2+ stores during each normal beat exerts a similar influence on membrane potential. To explore this, chick embryonic myocardial cell aggregates were voltage-clamped during abrupt exposure to caffeine, which is known to release Ca2+ from the sarcoplasmic reticulum. The speed of the perfusion system and the relative absence of diffusion barriers in the tissue-cultured cells allowed the effects of caffeine-induced Ca2+ release to be studied on a time scale comparable to that of a single normal beat. We report here that abrupt exposure of the cells to caffeine produced a transient inward current having similar features to that of digitalis toxicity, and which was both large enough and rapid enough to potentially contribute to the action potential.     

模拟文物铸铁的阴极保护

在模拟的文物铸铁上，研究已生成较厚锈层的带锈铸铁在３．５％ＮａＣｌ溶液中阴极保护的可能性和可行性，并确定最佳保护参数。结果表明，带锈铸铁的阴极保护是可行的；在本体系中最佳保护电位范围是－９００～－１０００ｍＶ（ＳＣＥ）；当保护电位比－１１００ｍＶ（ＳＣＥ）更负时，保护效率将显著降低。     

Iron deficiency induces the formation of an antenna ring around trimeric photosystem I in cyanobacteria

Although iron is the fourth most abundant element in the Earth's crust, its concentration in the aquatic ecosystems-particularly the open oceans-is sufficiently low to limit photosynthetic activity and phytoplankton growth. Cyanobacteria, a major class of phytoplankton, respond to iron deficiency by expressing the 'iron-stress-induced' gene, isiA(ref. 3). The protein encoded by this gene has an amino-acid sequence that shows significant homology with one of the chlorophyll a-binding proteins (CP43) of photosystem II (PSII). The precise function of the CP43-like protein, here called CP43', has not been elucidated, although there have been many suggestions. Here we show that CP43' associates with photosystem I (PSI) to form a complex that consists of a ring of 18 CP43' molecules around a PSI trimer. This significantly increases the size of the light-harvesting system of PSI. The utilization of a PSII-like protein as an extra antenna for PSI emphasises the flexibility of cyanobacterial light-harvesting systems, and seems to be a strategy which compensates for the lowering of phycobilisome and PSI levels in response to iron deficiency.