阿尔茨海默病中β淀粉样蛋白的生成及清除的调节

阿尔茨海默病（Alzheimer’s disease, AD）是一种慢性退行性神经系统疾病,临床主要表现为进行性认知能力下降、记忆力衰退、人格改变等。AD的标志性病理特征包括脑细胞外β淀粉样蛋白（β-amyloid protein,Aβ）沉积形成老年斑、细胞内神经纤维缠结(neurofibrillary tangles,NFT)、神经炎症增加以及神经元凋亡。β淀粉样蛋白主要在神经元产生,是淀粉样前体蛋白经过一系列酶解反应生成的由39～42个氨基酸组成的多肽,调节Aβ的生成和清除能够有效延缓甚至逆转阿尔茨海默病的进程,因而具有重大的研究价值。β-分泌酶（β-site APP cleaving enzyme 1,BACE1）为Aβ产生过程中的关键酶,其含量及活性的改变均能影响Aβ产生,在阿尔茨海默病的发生发展中发挥至关重要的作用;老年斑周围炎性细胞的聚集提示,AD与神经炎症高度相关,神经炎症相关细胞能够参与Aβ的清除,多种炎性因子也能调节Aβ的生成;非编码RNA虽很少直接参与Aβ的产生、沉积和清除,但其可以通过多种途径调节Aβ的产生。本文从β淀粉样蛋白生成及清除的机制着手,重点阐述了BACE1、神经炎症、非编码RNA对Aβ调控的重要作用,以期为AD发病机制的进一步研究提供思路,并对阿尔茨海默病早期干预及治疗提供理论参考。     

bFGF Promotes the Proliferation of Rat Peripheral Blood Mesenchymal Stem Cells Through β-Catenin Signaling

bFGF (basic fibroblast growth factor, bFGF) could promote the proliferation of bone marrow and cord blood mesenchymal stem cells. However, the effect of bFGF on the proliferation of peripheral blood mesenchymal stem cells (PBMSCs) needs further research. This study aimed to investigate the role of bFGF on the culture and expansion of PBMSCs in vitro. Firstly, arterial blood was collected from rats abdominal aorta. After mononuclear cells (MNCs) were separated with Ficoll separation fluid, MNCs were cultured in the DMEM medium without bFGF (served as control group) or with bFGF (10, 20 ng/mL, served as 10 or 20 ng/mL bFGF group). PBMSCs were obtained by adherent culture method. The third passage of PBMSCs was detected for the MSC surface markers and the effect of bFGF on the cell cycle of PBMSCs using flow cytometry. The effects of bFGF on colony formation, cell growth, and the expressions of cyclin D1, cyclin E, p21 and β-catenin were evaluated. PBMSCs showed no difference in morphology among the three groups. PBMSC clonies appeared 14 days after cultivation. Compared with the control group, the cell growth confluence of PBMSCs was obviously increased by 40% and 80% in groups treated with 10 ng/mL bFGF or 20 ng/mL bFGF respectively after culture of 21 days (all P<0.05). Compared with the group treated with 10 ng/mL bFGF, the confluence of PBMSCs in 20 ng/mL group was further increased by 28% (P<0.05). Cells of the third passage were positively stained for CD29 and CD90, while were negative for CD45. These results were consistent with the phenotypic characteristics of MSCs. Compared with the control group, the colony number of PBMSCs in the 10 ng/mL and 20 ng/mL bFGF groups was increased by 51% (P<0.05) and 92% (P<0.05), respectively. Compared with the 10 ng/mL group, the colony number of PBMSCs was further increased in 20 ng/mL group by 14% (P<0.05). The growth curve of PBMSCs showed that after 7 days of culture, the number of PBMSCs in 10 ng/mL bFGF group and 20 ng/mL bFGF group was increased by 41% (P<0.05) and 61% (P<0.05), respectively. Moreover, the cell number had a statistically significant difference between these two groups (P<0.05). Results from flow cytometry cell cycle showed that the numbers of PBMSCs in the G1 phase of experimental groups were significantly decreased as the concentration of bFGF increased when compared with the control group (P<0.05), whereas the number of PBMSCs in the S phase was significantly increased (P<0.05). Immunofluorescence experiments showed that, compared with the control group, bFGF significantly promoted the nuclear translocation and expression of β-catenin in PBMSCs. Compared with the 10 ng/mL group, the PBMSCs in 20 ng/mL bFGF group showed stronger nuclear translocation and expression of β-catenin. Western blot experiments showed that the levels of β-catenin and its target proteins cyclinD1 and cyclinE were significantly increased (all P<0.05), whereas expression of p21 was significantly decreased in PBMSCs in the bFGF groups in a concentration dependent pattern when compared with control group (P<0.05). The study firstly confirms that bFGF promotes the proliferation of PBMSCs by regulating the β-catenin signaling pathway, which may facilitate the aquisition of larger number of PBMSCs for stem cell engineering in vitro.     

Activation of Nrf2 by SFN Improves Hypoxic Exercise Endurance and Lactate Metabolism in Red and White Skeletal Muscles of Mice

Exercise endurance is closely related to the production and elimination of lactate in skeletal muscles. It has been confirmed in literature that nuclear factor erythroid-2-related factor 2 (Nrf2) plays an important role in exercise-induced skeletal muscle antioxidant, mitochondrial biosynthesis and energy metabolism. However, it is still unclear whether Nrf2 activation has any effect on lactate metabolism and exercise endurance under hypoxic environment. In this study, sulforaphane (SFN), the Nrf2 activator, was pretreated to mice and then the mice were subjected to an exhaustive exercise under hypoxia (11.2% O₂). The results showed that the exhaustive exercise significantly increased the blood lactate level in PBS-exercise group (P<0.05). However, this indicator in the SFN-exercise group was only 76% of that in the PBS-exercise group (P<0.05). Also, the running distance increased from 577.0 ± 52.9 m to 636.3 ± 101.4 m and the duration increased by 1.1 times as well (P<0.05). Western blotting was used to determine the relative expression of proteins in skeletal muscles. Protein expression levels of Nrf2 and p-Nrf2 in the SFN-control and SFN-exercise group were significantly increased in soleus (P<0.05). In extensor digitorum longus, SFN pretreatment induced the expression of p-Nrf2 increased by 38% and 52%, respectively (P<0.05). In addition, SFN pretreatment promoted MCT1 protein expression in SFN-Control/ SFN-Exercise group and decreased MCT4 protein expression level in SFN-Exercise group (P<0.05). Meanwhile, the expression of LDH-B proteins in soleus was increased by 62% (P<0.05). In extensor digitorum longus, expression of LDH-B in the SFN-control and SFN-exercise group was increased by 1.35 times and 1.31 times, respectively (P<0.05). These results suggested that activation of Nrf2 by SFN could improve the lactate transport and metabolism capacity of skeletal muscle, which probably was one of the potential reasons for the increased exercise endurance of mice in the hypoxic environment. This study provided some theoretical reference for the practical application of SFN in athletes, mountaineers and highland workers.     

卵巢早衰患者血清抑制素B、抗苗勒管激素及性激素水平与子宫动脉血流参数的相关性研究

目的:探讨卵巢早衰(POF)患者血清抑制素B(INHB)、抗苗勒管激素(AMH)及性激素水平与子宫动脉血流参数的相关性。方法:选择2018年5月至2020年5月期间我院收治的126例POF患者(POF组)和同期于我院进行体检的85例健康女性志愿者(对照组)。检测所有研究对象血清INHB、AMH以及促黄体生成素(LH)、促卵泡激素(FSH)、雌二醇(E2)水平,经阴道多普勒超声检测子宫动脉血流参数[收缩期峰值流速(PSV)、舒张末期流速(EDV),血流阻力指数(RI)、搏动指数(PI)]。Pearson相关性分析POF患者血清INHB、AMH、LH、FSH、E2水平与PSV、EDV、RI、PI的相关性。结果:POF组血清INHB、AMH、E2水平、PSV、EDV低于对照组(P<0.05),LH、FSH水平、RI、PI高于对照组(P<0.05)。Pearson相关性分析结果显示POF患者血清INHB、AMH、E2水平与PSV、EDV呈正相关(P<0.05),与RI、PI呈负相关(P<0.05),LH、FSH与PSV、EDV呈负相关(P<0.05),与RI、PI呈正相关(P<0.05)。结论:POF患者血清INHB、AMH、E2水平降低,LH、FSH水平升高,血清INHB、AMH和性激素与子宫动脉血流受限有关。     

同型半胱氨酸对孕鼠糖代谢的影响与机制分析

目的:探讨同型半胱氨酸(homocysteine,HCY)摄入后对孕鼠糖代谢的影响以及生物学机制分析。方法:孕鼠妊娠10 d后,将实验动物随机分为3组,每组12只,妊娠对照组(Ctrl)腹腔注射生理盐水,同型半胱氨酸高剂量组(HCYH)和同型半胱氨酸低剂量组(HCYL)腹腔注射HCY溶液,注射浓度分别为200 mg/kg·d和100 mg/kg·d,持续20 d(即为HCY20 d)后,利用血糖含量检测试剂盒和胰岛素试剂盒分别检测孕鼠空腹血糖水平、胰岛素水平;葡萄糖检测试剂盒对孕鼠葡萄糖耐量和胰岛素抵抗进行检测;蛋白免疫印迹法检测孕鼠目的蛋白过氧化物酶体增殖物激活受体γ(PPARγ)、葡萄糖转运蛋白4(GLUT4)、蛋白激酶B(AKT)、磷酸化AKT蛋白(P-AKT)的表达。结果:与Ctrl组比较,在孕鼠注射HCY后,空腹血糖水平升高、血清中胰岛素浓度下降、HOMA-β指数下降、HOMA-IR指数升高(P<0.05);摄入葡萄糖后,孕鼠血糖随时间的变化而下降,葡萄糖曲线下面积升高(P<0.05);摄入胰岛素后,孕鼠血糖随时间的变化而升高,胰岛素曲线下面积升高(P<0.05);PPARγ、P-AKT、GLUT4蛋白表达水平下降,HCYH组降低水平更为显著(P<0.05)。结论:孕鼠HCY摄入后,生物体糖代谢紊乱,AKT磷酸化表达水平抑制,HCY可能通过降低PPARγ的表达减少AKT磷酸化,导致胰岛素受体的活化,进而激活了PI3K/AKT通路,减少了脂肪组织中的GLUT4表达,增加了对于葡萄糖的摄取能力。     

雄激素去势治疗联合多西他赛对晚期前列腺癌患者血清hk2、miR-221及NF-κB水平的影响

目的:研究雄激素去势治疗联合多西他赛对晚期前列腺癌患者血清人激肽释放酶(hk2)、微核糖核酸-221(miR-221)及核转录因子-κB(NF-κB)水平的影响。方法:选择我院2014年9月~2016年1月收治的80例晚期前列腺癌患者为研究对象,依据随机数字表法分为对照组和实验组,各40例。对照组采用单纯雄激素去势治疗,实验组采用雄激素去势治疗联合多西他赛,对比两组临床疗效,治疗前后血清前列腺抗原(PSA),hk2、miR-221及NF-κB水平,生活质量,不良反应和生存情况。结果:治疗后,实验组总有效率显著高于对照组,差异有统计学意义(P<0.05)。治疗后,两组血清PSA、hk2、miR-221及NF-κB水平水平均显著低于治疗前,实验组以上指标明显低于对照组(P<0.05)。治疗后,实验组机体状况及生活状况较对照组高(P<0.05);两组家庭状况、情感状况、与医师关系及前列腺癌特异性生活质量评分比较差异无统计学意义(P>0.05)。治疗后,实验组机体状况及生活状况较对照组高(P<0.05);两组家庭状况、情感状况、与医师关系及前列腺癌特异性生活质量评分比较无统计学差异(P>0.05)。两组1年生存情况比较差异无统计学意义(P>0.05);实验组2年生存例数多于对照组(P<0.05)。结论:雄激素去势治疗联合多西他赛能够降低血清hk2、miR-221、NF-κB水平,改善患者生活质量及生存情况。     

A novel dominant-negative PD-1 armored anti-CD19 CAR T cell is safe and effective against refractory/relapsed B cell lymphoma

Refractory/relapsed B cell lymphoma patients who received the available anti-CD19 chimeric antigen receptor (CAR) T cells may still experience a short duration of remission. Here in this study, we evaluated the safety and efficacy of a novel dominant-negative programmed cell death-1 (PD-1) armored anti-CD19 CAR T cells. A total of 9 patients (including 4 diffuse large B cell lymphomas, DLBCL, 2 transformed follicular lymphomas, TFL, and 3 follicular lymphomas, FL) received the novel CAR T cells infusion at a dose of more than 1 × 10⁶/kg. Grade ≥ 3 cytokine release syndrome (CRS) and neurotoxicity were observed in 11.1% (n = 1/9) and 11.1% (n = 1/9) of patients, respectively. The overall response rate (ORR) was 77.8% (n = 7/9) and complete response (CR) rate was 55.6% (n = 5/9). Two patients have ongoing CR (all at 20+ months). CAR T cells expanded after infusion and continued to be detectable at 12+ months in patients with ongoing CR. This novel CD19-CAR T cell was safe and effective with durable remissions in patients with refractory/relapsed B cell lymphoma.     

玉米灵芝菌粮营养成分及加工特性变化研究

玉米作为主要的杂粮谷物,营养价值高,维生素、膳食纤维等含量丰富,可以预防多种亚健康疾病,受到市场追捧。但是玉米粉营养结构不均衡、加工性差,限制其应用。有研究表明,微生物发酵技术可以改善谷物的营养成分、大分子物质结构和加工特性。基于此,利用灵芝固态发酵玉米,得到玉米灵芝菌粮（简称菌粮）,从营养成分、大分子物质结构和加工特性3个方面对其进行评价。结果显示,与未发酵玉米相比,菌粮中碳水化合物、蛋白质含量分别提高了748%、28.00%,且蛋白质的氨基酸评分提高,而脂肪含量降低了52.56%;维生素C、核黄素和烟酸含量均显著提高（P<0.05）,分别提高了56.19%、73.91%和20.27%,且玉米中缺乏的硫胺素在菌粮中被检测到;菌粮中各类淀粉和纤维的含量也发生了显著变化（P<0.05）,淀粉、支链淀粉含量分别降低了11.17%、34.70%,直链淀粉含量提高了26.66%,粗纤维、不溶性膳食纤维含量分别降低了21.07%、21.47%,可溶性膳食纤维含量提高了13.57%;菌粮粉粘度降低,水溶性指数提高,吸水性指数和溶胀力降低;此外,与灵芝子实体相比,菌粮中灵芝三萜和灵芝酸含量均显著提高（P<0.05）,分别为灵芝子实体的1.68和2.07倍。灵芝固态发酵玉米得到的玉米灵芝菌粮,营养结构更加均衡,功能活性提高,具有更高的营养价值;大分子物质结构发生改变,加工特性得到改善,冲调特性更好。研究结果为食用菌发酵改良谷物特性的研究提供了参考和指导。     

小麦抗赤霉病外源种质的创制和育种利用

小麦赤霉病是危害小麦安全生产的重要病害之一,种植抗病品种是防治赤霉病最经济有效的手段。目前在生产上应用的抗源很少,越来越多的研究者将目光转移到小麦的近缘属种,寻找新的抗源以及寻求新的育种突破。携带抗性基因的外源染色体可以通过染色体工程手段以附加系、代换系和易位系等形式导入小麦。综述了将大赖草等多个小麦近缘种的抗赤霉病基因导入普通小麦、创制抗病外源种质和育种利用的最新研究进展,以期为小麦抗赤霉病育种提供参考信息。     

环状RNA及其在生态毒理学研究中的应用进展

环状RNA（circular RNAs,circRNAs）是一类共价闭合环状非编码RNA,具有进化上保守、结构上稳定、组织特异性表达等特点。CircRNAs可作为miRNAs海绵影响其对基因的调控,还可与RNA结合蛋白（RNA binding proteins,RBPs）相互作用,也有研究表明某些circRNAs还具有被翻译成蛋白质的潜能。CircRNAs已被证实对某些疾病具有特异性、稳定性和调节功能,如癌症、糖尿病、心血管疾病、神经退行性疾病等,其可作为潜在的诊断、预后生物标志物和治疗靶点。最近,有研究发现circRNAs参与了环境化学污染物诱导的毒性效应发生及发展的过程。目前,生态毒理学研究中评价环境化学污染物和毒效应之间关系的毒性终点通常会受遗传多态性和表观遗传学影响,考虑到经环境化学污染物暴露后生物体内circRNAs差异性表达的现象,或许在生态毒理学研究中circRNAs也有作为生物标志物的可能性。基于此,对circRNAs的生物合成与降解、生物学功能、分析方法及其目前在生态毒理学研究中的应用展开综述,并对其作为分子生物标志物在环境污染物暴露早期诊断和生态风险评价中的应用进行了展望,以期为生态毒理学研究和环境风险评价提供参考。