Expression profile of IGF system during lung injury and recovery in rats exposed to hyperoxia: a possible role of IGF-1 in alveolar epithelial cell proliferation and differentiation

Although several studies have shown that an induction of insulin-like growth factor (IGF) components occurs during hyperoxia-mediated lung injury, the role of these components in tissue repair is not well known. The present study aimed to elucidate the role of IGF system components in normal tissue remodeling. We used a rat model of lung injury and remodeling by exposing rats to > 95% oxygen for 48 h and allowing them to recover in room air for up to 7 days. The mRNA expression of IGF-I, IGF-II, and IGF-1 receptor (IGF-1R) increased during injury. However, the protein levels of these components remained elevated until day 3 of the recovery and were highly abundant in alveolar type II cells. Among IGF binding proteins (IGFBPs), IGFBP-5 mRNA expression increased during injury and at all the recovery time points. IGFBP-2 and -3 mRNA were also elevated during injury phase. In an in vitro model of cell differentiation, the expression of IGF-I and IGF-II increased during trans-differentiation of alveolar epithelial type II cells into type-I like cells. The addition of anti-IGF-1R and anti-IGF-I antibodies inhibited the cell proliferation and trans-differentiation to some extent, as evident by cell morphology and the expression of type I and type II cell markers. These findings demonstrate that the IGF signaling pathway plays a critical role in proliferation and differentiation of alveolar epithelium during tissue remodeling.     

Ontogenetic changes in spot configuration (numbers,circularity, size and asymmetry) and lateral line in Neurergus microspilotus (Caudata: Salamandridae)

Coloration in three of four species of the genus Neurergus including N. microspilotus is characterized by the presence of yellow spots on a dark skin, but there is no available information about changes in spot configuration, speed of development and degree of association between melanophore‐free region and the lateral line. In this study, spot numbers, spot circularity, spot size and spot asymmetry were studied during larval to adult growth in N. microspilotus during July 2012 to June 2015. The mean numbers of spots increased during the late larval stage till postmetamorphic period from 13.33 ± 3.77 to 22.53 ± 4.09 and reached 42.62 ± 4.06 in adults. At the same time, the extent of spots gradually decreased in size from 5.80 ± 1.00 to 3.57 ± 0.97 mm² and reached 3.55 ± 1.42 mm² in adults, but the spot circularity increased from 0.48 ± 0.23 to 0.78 ± 0.49 and reached 0.80 ± 0.15 in adults. In adults, the numbers, circularity, size and asymmetry of spots remain stable with little but non‐significant changes during the study period. Histological study shows that formation of a melanophore‐free region correlates with the development of the lateral line receptors. This study demonstrates that the effects of lateral line on chromatophores persist through middle larval stages but diminish as metamorphosis completes.     

表达CD19~+CD56~-的多发性骨髓瘤浆细胞免疫表型的鉴别

目的:研究多发性骨髓瘤患者浆细胞和对照组正常浆细胞免疫表型,有效地识别表达CD19+CD56-的多发性骨髓瘤恶性浆细胞。方法:采用四色流式细胞仪(BD,FACSCalibur)检测44例MM患者浆细胞以及25例健康骨髓捐献者正常浆细胞膜上的抗原表达。采用CellQuest软件分析结果。细胞膜表面抗原表达率大于20%定义为表达阳性。阳性率为表达阳性的患者及健康对照者所占百分比。结果:44例MM患者浆细胞免疫表型表达频率为:CD138+:97.72%(43/44)、CD38+:100%(44/44)、CD56+:63.64%(28/44)、CD19-:84.09%(37/44)、CD200+:77.27%(34/44)、CD28+:38.64%(17/44);25例对照组正常浆细胞免疫表型表达频率为:CD138+:100%(25/25)、CD38+:100%(25/25)、CD56-:100%(25/25)、CD19+:96%(24/25)、CD200+:0%(0/25)、CD28+:0%(0/25)。在44例MM患者中,9%(4/44)患者表达CD19+CD56-,利用CD200检测4例表达CD19+CD56-的患者,有3例患者伴有CD200阳性表达,可与正常浆细胞鉴别。结论:CD200有利于鉴别表达CD19+CD56-MM恶性浆细胞与正常浆细胞。     

骨髓间质干细胞移植治疗大鼠脑出血模型的实验研究

目的:研究大鼠骨髓间质干细胞(MSCs)移植治疗脑出血的可行性。方法:分离MSCs后,连续传代培养、扩增,Brdu标记的MSCs通过颈动脉、侧脑室2种途径移植入脑出血大鼠模型体内,采用爬行计分法评估神经功能的恢复程度,并观察脑部Brdu阳性细胞的分布。结果:通过侧脑室、颈动脉移植后大鼠神经功能改善,明显优于对照组(P<0.05);经颈动脉注射组较经侧脑室注射组爬杆实验评分低(P<0.05)。移植的MSCs主要迁移到出血灶、大脑皮层、海马区等处。结论:MSCs移植对脑出血具有保护作用,而经颈动脉给药疗效优于经侧脑室给药。     

巨噬细胞、内皮细胞对高密度脂蛋白的氧化修饰

为了探讨高密度脂蛋白 (HDL)在体内发生氧化修饰的部位及机制 ,分别观察了培养人动脉平滑肌细胞 (SMC)、动脉内皮细胞 (EC)及巨噬细胞 (MΦ)与HDL共同温育过程中 ,HDL的琼脂糖电泳相对迁移率 (REM)、硫代巴比妥酸反应物质 (TBARS)以及溶血卵磷脂 卵磷脂 (LPC PC)值等氧化指标的变化 .结果发现 ,HDL与 3种细胞温育 12h时 ,HDL几乎不发生氧化修饰 ,而HDL与MΦ和EC温育 2 4h后 ,其REM、TBARS、LPC PC值均显著上升 (p <0 0 1) ;而HDL与SMC温育后 ,其REM、TBARS值无显著改变 ,LPC PC值增加 (p <0 0 1) .结果提示 ,活体内HDL可能主要在动脉壁的内皮细胞及巨噬细胞的作用下发生氧化修饰     

猫嗅球外丛层和僧帽细胞层年龄相关形态学变化

分别用Nissl法及免疫组织化学ABC法标记青、老年猫嗅球中嗅觉二级神经元和外丛层胶质细胞,显微镜下观察其分布并计数,对嗅觉二级神经元胞体直径和外丛层厚度进行测量,比较其年龄相关性变化,研究神经元与胶质细胞之间的关系,探讨老年性嗅觉功能衰退的相关神经机理。结果显示,老年猫嗅觉二级神经元胞体直径和分布密度均有不同程度的显著性下降(P<0.05);外丛层厚度变化不明显(P>0.05);外丛层胶质细胞特别是星形胶质细胞显著性增生(P<0.05)。表明在衰老过程中嗅觉二级神经元有丢失,并呈现功能下降,可能是老年性嗅觉功能衰退的原因之一。同时外丛层胶质细胞增生以进一步保护神经元,延缓其衰老。     

β-TCP支架体外构建组织工程骨及其流体力学研究

骨髓基质干细胞在β-tricalciumphosphate(β-TCP)支架上分别进行了1、2和4周的三维动态培养,对支架上不同时间和部位的细胞面积/微孔面积及支架动态培养的流体环境进行了研究.研究表明,第1周细胞在支架大部分孔道内粘附生长并出现一定区域的单细胞层和多细胞层,第2周部分区域的部分孔道已填满了细胞并出现多细胞层,第4周大部分孔道几乎填满了细胞,主管道内壁出现了较多的细胞生长.同时发现,支架上各个区域细胞粘附面积不等,部分区域无细胞存在,有的部位2周后细胞逐渐减少.为了研究支架各个位置细胞増殖与流速、剪切应力的关系,建立了支架随机孔道结构的流体分析模型,通过支架上流速和剪切应力分布探讨实验中细胞分布现象的机理.结合计算和实验发现,流体能流到的部位几乎都有细胞生长,细胞生长较快的部位速度大多集中在0.24～0.53mm/s,剪切力大多在0.0050～0.023Pa,主管道底部及靠近进口的部位可能存在由于过大的剪切力影响细胞生长的区域.上述结果在一定程度上反映了细胞-支架-流体三者在成骨转化过程中的作用,对指导体外灌注培养的流量确定、灌注工艺及骨转化动力学研究有重要的意义.     

缺氧环境下白细胞介素8通过Akt-STAT3通路提高骨髓间充质干细胞自噬和增殖能力

探讨缺氧环境下,白细胞介素8(Interleukin-8,IL-8)对人骨髓间充质干细胞(Human bone marrow mesenchymal stem cells,hBMSC)增殖和自噬能力的影响以及机制。在缺氧模型下,未进行刺激的hBMSC为缺氧对照组;以100μmol/L人IL-8蛋白刺激的MSC为IL-8组;若先添加50μmol/L MK2206(Akt蛋白抑制剂)培养30 min,然后再添加100μmol/L IL-8则为Akt抑制剂组,在正常条件下培养的MSC为正常对照组。利用Ed U细胞增殖实验、TUNEL细胞凋亡实验、Western blotting或ELISA等实验分别检测各组MSC细胞Ed U标记阳性细胞的数目、细胞凋亡、自噬蛋白(LC-3)和Akt/STAT3等蛋白的表达。相对于缺氧对照组和Akt抑制剂组,IL-8明显提高hBMSC增殖和细胞自噬,并降低hBMSC的凋亡率,IL-8组hBMSC的Akt、STAT3和VEGF等蛋白表达增高。结果表明,缺氧环境下,IL-8通过Akt-STAT3通路发挥对MSC的保护作用,对保护MSC抗缺血缺氧性损伤,促进MSC在再生医学中应用具有重要意义。