抗胰岛素样生长因子结合蛋白相关蛋白1对小鼠肝纤维化的保护作用

胰岛素样生长因子结合蛋白相关蛋白1(IGFBPrP1)是肝纤维化发生机制中的一种新的致病因子,能够激活体外培养的肝星状细胞(HSC),能够使重要的细胞外基质成分1型胶原(Coi Ⅰ)与纤维连接蛋白(FN)的合成增加[1].     

细胞外信号调节激酶在糖尿病大鼠肺病变中的作用

目的　观测糖尿病大鼠肺组织的病理改变及蛋白激酶C、胞外调节蛋白激酶活性的变化 ,探讨细胞信号传导系统在糖尿病大鼠肺病变中的作用。方法　制作糖尿病大鼠模型 ,4w后应用透射电镜观察大鼠肺组织病理改变 ,采用改良的Takay法测定蛋白激酶C活性 ,同位素法及蛋白质免疫印迹分析方法检测胞外调节蛋白激酶在糖尿病大鼠肺组织表达的变化。结果　糖尿病大鼠 4w肺组织病理改变为毛细血管基底膜及Ⅱ型肺泡上皮细胞基底膜不同程度增厚 ,肺间质胶原成份增多 ,蛋白激酶C、胞外调节蛋白激酶在肺组织活性增强。结论　链脲菌素糖尿病大鼠肺组织高糖环境下细胞内信号传导系统被激活 ,可能参与了糖尿病肺部并发症的发生和发展     

肝基质鼠尾胶对日本血吸虫培养细胞AKP和ACP影响的研究

目的 研究肝基质、鼠尾胶对日本血吸虫成虫培养细胞碱性磷酸酶(AKP)和酸性磷酸酶(ACP)活性的影响,筛选适合日本血吸虫细胞培养的基质。方法 将虫龄28d的日本血吸虫成虫细胞,接种于预先铺敷有肝基质和鼠尾胶的小盖玻片上常规培养,未铺敷基质者作对照。运用酶细胞化学方法,分别于培养5、14、21、35d对日本血吸虫成虫培养细胞进行AKP和ACP染色,显微镜下观察并拍照,图像分析仪测定其含量,并作统计分析。结果 铺敷的基质不同,培养细胞的AKP和ACP活性不同。AKP、ACP着色深浅均按对照组、鼠尾胶组、肝基质组依次加深。定量分析显示,培养14d内,肝基质组与鼠尾胶组细胞AKP活性明显高于对照组(肝基质组P<0.01;鼠尾胶组P<0.05);两基质组培养细胞之间差异也有显著性(P<0.05)。培养21d后,肝基质组细胞AKP活性分别高于鼠尾胶组和对照组(P<0.01);后两者培养细胞之间的AKP活性无明显差异(P>0.05)。培养5d细胞的ACP活性,肝基质组与鼠尾胶组明显高于对照组(P<0.05),两基质组相互比较差异无显著性(P>0.05);培养14d后,各组之间两两比较均有差异(P<0.05),肝基质组培养细胞ACP活性最强,鼠尾胶组次之,对照组最弱。结论 肝基质较为适合日本血吸虫培养细胞的存活与生长。     

Effects of hypoxia and altered K0 on the membrane potential of rabbit ventricle

The upstroke of the ventricular action potential in the rabbit consits of two depolarizing components with different rates of rise. The effects of hypoxia on the resting potential (RP); the upstroke phases (I and II) and the maximum rate of rise of phase I ( _max) were studied at different external K concentrations (K₀). Perfused hearts were submitted to N₂-equilibrated media containing 1.5 to 10 m K₀. Exposure of oxygenated hearts to different K₀ changed the regenerative response from a fast rising action potential at 1.5 m K₀ to a depressed fast response at 7.5 and 10 m K₀. Hypoxia decreased the action potential amplitude (APA) at all K concentrations. In K₀ ≤ 5 m the reduction of APA was due to a decrease in the amplitude of phase II of the upstroke but the maximum rate of rise ( _max) did not change. In contrast, phase I of the upstroke was markedly depressed by hypoxia in high K₀, but phase II was unmodified and its _max compared well with values reported for other normoxic cardiac cells. Hyperkalemia per se did not slow conduction during normoxia but increased conduction time in hypoxia. The resting potential of hypoxic cells was closer to the K equilibrium potential than in the control. The RP v. K₀/K_i relation suggested that electrogenic Na extrusion persists in hypoxia. The electrogenic fraction of the resting potential as determined from pump inhibition with 10⁻⁴ ouabain amounted to −6 mV. Our results did not indicate whether the differential effects of hypoxia on the upstroke components were potential dependent or were related to direct effects of K⁺ on the ionic currents that determine the action potential. The persistence of phase II during hypoxia in partly depolarized cells may assure the maintenance of propagated electrical activity under conditions that are likely to be encountered in vitro during cardiac ischemia.     

正常胃黏膜上皮细胞原代培养方法

胃黏膜上皮细胞是进行胃生理功能、病变机制、药物治疗等研究的重要工具，已被广泛应用于科学实验。原代培养细胞能反映原始组织的特点，与体内姊妹细胞的生理状态相似，是进行相关研究的理想材料。但胃黏膜上皮细胞对内环境要求较高，分离纯化后并不象肝细胞等易于存活和生长，不少实验因这一环节而不能进行下去，不得不采用从肿瘤组织衍生的各种细胞株，此类细胞株与正常胃黏膜上皮细胞在生长特性、形态结构等方面存在较大差异，不能代表正常胃黏膜上皮。在我国，几乎所有的相关研究都是采用各种细胞株，因此本文较详细全面地介绍了文献报道中较成功的正常胃黏膜上皮细胞原代培养方法，以期对相关研究有所帮助。     

Ⅰ、Ⅲ、Ⅳ、Ⅴ型胶原和层连蛋白在人肝硬化和肝细胞癌中的分布

正常肝脏肝窦壁ＩＶ型胶原和层连蛋白染色阳性，说明存在基底膜结构，是为功能性基底膜。肝硬化时肝窦毛细血管化，使功能性基底膜破坏。肝硬化时各种细胞外基质成分显著增多，以Ⅰ型胶原为最多。由于各成分增多程度不一致，使细胞外基质的构成发生了改变。原发性肝细胞性肝癌组织中细胞外基质的分布与含量与癌组织的分化程度密切相关。分化程度高，细胞外基质沿癌组织小粱间的血窦壁排列成连续或断续线状；分化程度低，癌组织的细胞外基质仅见于血管壁。     

干扰素α干预对大鼠胰腺纤维化的影响

目的 观察干扰素α(INF-α)对DDC诱导的胰腺纤维化大鼠模型纤维增生程度、胰腺星状细胞活化标志物α-平滑肌肌动蛋白(α-SMA)和细胞外基质成分Ⅲ型胶原蛋白表达的影响.方法 Wistar大鼠40只随机数字法分成对照组、纤维化组和干扰素组.纤维化组和干扰素组每周2次腹腔内注射DDC,干扰素组在造模同时每天皮下注射INF-α10万U.6周末取材,光镜下观察胰腺病理学变化.免疫组化法测定胰腺组织中α-SMA、Ⅲ型胶原蛋白的表达.结果 第4周起纤维化组大鼠体重增长缓慢甚至下降,干扰素组体重仍缓慢增长,5周后两组差异显著[(309.8±19.7)g与(277.3±19.9)g,P＜0.05].纤维化组胰腺组织纤维化表现明显,纤维化分值、Masson染色值、α-SMA和Ⅲ型胶原蛋白相对表达量分别为2.679±0.899、218.713±36.102、148.971±30.686和88.142±42.581;干扰素组纤维化减轻,上述指标分别为1.952±0.219、114.732±24.912、77.237±9.275和59.952±25.498,均较纤维化组显著降低(P＜0.05).结论 给予INF-α能显著减轻纤维化程度和α-SMA、Ⅲ型胶原表达,对DDC诱导的大鼠胰腺纤维化有一定的预防作用.     

Role of extracellular matrix in insulin-like growth factor (IGF) binding protein-2 regulation of IGF-II action in normal human osteoblasts

Insulin-like growth factor binding protein-2 (IGFBP-2) in its native form had little affinity for extracellular matrix (ECM) derived from human or rat osteoblastic cells. However, in the presence of IGFs, IGFBP-2 binding to ECM was markedly enhanced, with IGF-II being more effective than IGF-I. IGF-II-enhanced binding of IGFBP-2 to ECM was specific for IGFBP-2 of the six known IGFBPs. In the presence of IGF-II, IGFBP-2 bound with high affinity to heparin-Sepharose, but not to type I collagen, fibronectin, or laminin. Furthermore, heparin and heparan sulfate, but not chondroitin sulfate, inhibited IGFBP-2/IGF-II binding to ECM. High salt (100 mM NaCl) inhibited, while CaCl(2) enhanced binding of IGFBP-2/IGF-II to ECM. In the presence of ECM, IGFBP-2/IGF-II was as effective as IGF-II alone in stimulating [3H]thymidine and [3H]proline incorporation and in inhibiting apoptosis in cultured human osteoblasts. On the other hand, IGFBP-2 was a potent inhibitor of IGF-II action in human breast and ovarian carcinoma cells. There was no difference between soluble and ECM-associated IGFBP-2 in affinity for IGF-I and IGF-II. These data suggest a unique mechanism for targeting an anabolic IGFBP-2/IGF-II complex in bone.     

Adrenomedullin and adrenotensin regulate collagen synthesis and proliferation in pulmonary arterial smooth muscle cells

To understand the pathophysiological mechanisms of pulmonary arterial smooth muscle cell (PASMC) proliferation and extracellular-matrix accumulation in the development of pulmonary hypertension and remodeling, this study determined the effects of different doses of adrenomedullin (ADM) and adrenotensin (ADT) on PASMC proliferation and collagen synthesis. The objective was to investigate whether extracellular signal-regulated kinase (ERK1/2) signaling was involved in ADM- and ADT-stimulated proliferation of PASMCs in 4-week-old male Wistar rats (body weight: 100-150 g, n=10). The proliferation of PASMCs was examined by 5-bromo-2-deoxyuridine incorporation. A cell growth curve was generated by the Cell Counting Kit-8 method. Expression of collagen I, collagen III, and phosphorylated ERK1/2 (p-ERK1/2) was evaluated by immunofluorescence. The effects of different concentrations of ADM and ADT on collagen I, collagen III, and p-ERK1/2 protein expression were determined by immunoblotting. We also investigated the effect of PD98059 inhibition on the expression of p-ERK1/2 protein by immunoblotting. ADM dose-dependently decreased cell proliferation, whereas ADT dose-dependently increased it; and ADM and ADT inhibited each other with respect to their effects on the proliferation of PASMCs. Consistent with these results, the expression of collagen I, collagen III, and p-ERK1/2 in rat PASMCs decreased after exposure to ADM but was upregulated after exposure to ADT. PD98059 significantly inhibited the downregulation by ADM and the upregulation by ADT of p-ERK1/2 expression. We conclude that ADM inhibited, and ADT stimulated, ERK1/2 signaling in rat PASMCs to regulate cell proliferation and collagen expression.