Excited state charge-transfer dynamics study of poplar plastocyanin by ultrafast pump-probe spectroscopy and molecular dynamics simulation

We have applied ultrafast pump-probe spectroscopy to investigate the excited state dynamics of the blue copper protein poplar plastocyanin, by exciting in the blue side of its 600-nm absorption band. The decay of the charge-transfer excited state occurs exponentially with a time constant of approximately 280 fs and is modulated by well visible oscillations. The Fourier transform of the oscillatory component, besides providing most of the vibrational modes found by conventional resonance Raman, presents additional bands in the low frequency region modes, which are reminiscent of collective motions of biological relevance. Notably, a high frequency mode at approximately 508 cm(-1), whose dynamics are consistent with that of the excited state and already observed for other blue copper proteins, is shown to be present also in poplar plastocyanin. This vibrational mode is reproduced by a molecular dynamics simulation involving the excited state of the copper site.     

Circ_0025039 acts an oncogenic role in the progression of non-small cell lung cancer through miR-636-dependent regulation of CORO1C

Non-small cell lung cancer remains the leading cause of cancer-related death worldwide. Circular RNA plays vital roles in NSCLC progression. This study is designed to reveal the role of circ_0025039 in NSCLC cell malignancy. The RNA expression of circ_0025039, microRNA-636 (miR-636), and coronin 1C was detected by quantitative real-time polymerase chain reaction. Protein expression was checked by Western blot analysis or immunohistochemistry assay. Cell proliferation, migration, invasion, tube formation ability, sphere formation capacity, and apoptosis were investigated by cell counting kit-8, 5-Ethynyl-29-deoxyuridine, transwell assay, tube formation assay, sphere formation assay, and flow cytometry analysis, respectively. Mouse model assay was conducted to reveal the effect of circ_0025039 silencing on tumor formation in vivo. The interaction between miR-636 and circ_0025039 or CORO1C was identified through dual-luciferase reporter and RNA pull-down assays. The expression of circ_0025039 and CORO1C was significantly increased, while miR-636 was decreased in NSCLC tissues and cells compared with controls. Circ_0025039 depletion repressed NSCLC cell proliferation, migration, invasion, tube-forming capacity, and sphere formation ability, but induced cell apoptosis. The neoplasm formation was repressed after circ_0025039 silencing. Additionally, circ_0025039 acted as a sponge for miR-636, which was found to target CORO1C. Importantly, the contribution of circ_0025039 to NSCLC progression was mediated by miR-636/CORO1C axis. Circ_0025039 silencing repressed NSCLC malignant progression by reducing CORO1C expression through miR-636, showing the possibility of circ_0025039 as a therapeutic target for NSCLC.

     

乳杆菌对全子宫切除术后阴道微生态的影响

目的分析甲硝唑阴道准备联合全子宫切除术对患者阴道微生态的影响及乳杆菌的应用价值。方法采用前瞻性分析,收集2015年1月至2018年5月我院符合本研究相关标准并行腹腔镜全子宫切除的患者100例为研究对象,患者术前均用甲硝唑进行阴道准备。采用随机数字表将入选患者分为2组,每组50例。观察组患者在术后2个月时采用乳杆菌活菌胶囊阴道给药,1次/d,2粒/次,10 d/疗程,共3个疗程;对照组不处理。观察2组患者术前、术后2个月、术后3个月时阴道乳杆菌数量、pH值、菌群多样性、菌群密集度分级差异,同时对比观察组与对照组患者治疗前后阴道乳杆菌检出率、阴道菌群失衡率、pH值、FSFI分值。结果 (1)100例患者术后2个月时阴道乳杆菌数量、pH值、菌群多样性、菌群密度分级均显著减少,以Ⅰ级为主;术后3个月时以Ⅳ级为主。(2)与治疗前相比,两组患者阴道乳杆菌检出率均升高,阴道菌群失衡率均降低,pH值均降低,FSFI分值均升高(均P0.05);治疗前观察组与对照组阴道乳杆菌检出率、阴道菌群失衡率、阴道pH值、FSFI分值比较差异均无统计学意义(均P0.05);治疗后观察组患者阴道乳杆菌检出率高于对照组,阴道菌群失衡率、pH值低于对照组,FSFI分值高于对照组(均P0.05)。(3)观察组术后6个月内细菌性阴道病发生率为4.00%(2/50),对照组为16.00%(8/50),差异有统计学意义(χ~2=3.78,P=0.022)。结论甲硝唑阴道准备联合腹腔镜全子宫切除术患者术后阴道微生态环境被破坏,尤其以术后2个月最为明显,给予乳杆菌干预能促使被破坏的阴道微生态环境恢复正常,减少术后细菌性阴道病的发生,值得应用和推广。     

mTOR和PLGF在胎儿宫内生长受限中的作用机制

胎儿宫内生长受限(IUGR)是一种常见孕期疾病,有报道称其与滋养细胞的侵袭能力减弱有关,而mTOR和PLGF对滋养细胞侵袭有重要作用。为了探究m TOR和PLGF对滋养细胞侵袭力的影响,明确两者在IUGR发生和发展过程中的作用机制,本研究以孕早期人滋养细胞Swan 71为对象,利用雷帕霉素抑制mTOR的活化,通过小室侵袭实验、基因沉默和蛋白印迹法(Western blotting)观察了滋养细胞侵袭力和相关基因表达的变化,以及外源PLGF的添加对其结果有无影响。结果表明m TOR磷酸化受到抑制会导致滋养细胞的侵袭能力减弱,而PLGF能改善这种减弱现象,改善机制与增强p70、ERK和AKT磷酸化有关。然而,当mTOR基因被沉默后,PLGF就不能再改善或逆转因m TOR磷酸化缺失带来的细胞侵袭力的减弱。此外,本研究还发现mTOR磷酸化能调控PLGF和sflt-1的表达,后两者在IUGR发展中,常因为滋养细胞侵袭力的减弱而受到影响。