Dexmedetomidine protects rats from postoperative cognitive dysfunction via regulating the GABABR‐mediated cAMP‐PKA‐CREB signaling pathway

This work attempts to discuss whether dexmedetomidine (Dex) can protect rats from postoperative cognitive dysfunction (POCD) through regulating the γ‐aminobutyric acid‐_B receptor (GABA_BR)‐mediated cyclic adenosine monophosphate (cAMP) – protein kinase A (PKA) – cAMP‐response element binding (cAMP‐PKA‐CREB) signaling pathway. Sprague‐Dawley rats were divided into a non‐surgical group (Control), a surgical group (Model), a surgical group treated with Dex (Model + Dex), a surgical group treated with GABA_BR antagonist (Model + CGP 35348) and a surgical group treated with Dex and GABA_BR agonist (Model + Dex + Baclofen). Cognitive and memory functions were evaluated by Y‐maze test and open‐field test. The neuronal morphology of the hippocampus was observed by hematoxylin and eosin staining and neuronal apoptosis was by terminal deoxynucleotidyl transferase‐mediated dUTP‐biotin nick‐end labeling method. Inflammatory factors and cAMP levels were detected by enzyme‐linked immunosorbent assay while expressions of GABA_BR and PKA‐CREB pathway‐related molecules by Western blot. Compared with control rats, the model rats exhibited reduced alternation rates with a prolonged time spent in the central zone; meanwhile, levels of tumor necrosis factor‐α and interleukin‐1β and the apoptotic index, as well as GABA_BR1 and GABA_BR2 expressions were increased in the model rats, but the cAMP‐PKA‐CREB pathway was inhibited (all P < 0.05). When treated with either Dex or CGP 35348, the surgical rats displayed an opposite tendency concerning the above factors as compared to the model rats (all P < 0.05). Furthermore, Baclofen, the agonist of GABA_BR, could reverse the protective effect of Dex against POCD in rats. Dex protects rats from POCD possibly via suppressing GABA_BR to up‐regulate the cAMP‐PKA‐CREB signaling pathway, thereby alleviating the hippocampal inflammation caused by surgical trauma.     

Malignant progression of an extraventricular neurocytoma arising from the VIIIth cranial nerve: A case report and literature review

A rare case of extraventricular neurocytoma (EVN) arising from the VIIIth cranial nerve in a 34‐year‐old woman is reported. The patient had a 20‐year history of hearing loss and facial palsy. Computed tomography showed a 3‐cm enhancing lesion in the left cerebellopontine angle (CPA). At operation, the tumor was seen to originate from the cochlear and vestibular nerves. The tumor was subtotally resected. Histologically, the tumor consisted of uniform cells with oval to round nuclei and scant cytoplasm. Immunohistochemically, the tumor cells were positive for synaptophysin, but negative for glial fibrillary acid protein and S‐100 protein. The Ki‐67 labeling index was 0%. Twelve years after the operation, magnetic resonance imaging (MRI) showed tumor recurrence at the left CPA. The tumor was subtotally resected, and radiation therapy was given. Histologically, the tumor consisted of round cells with mild atypia and one mitosis/20 high‐power fields (HPF). Immunohistochemically, tumor cells showed the same findings as the first operation sample, except for the Ki‐67 labeling index (3%). Twelve years after the second operation, MRI showed a second tumor recurrence at the left CPA and surroundings of the brain stem. The tumor was subtotally resected. Histologically, the tumor consisted of anaplastic short spindle cells and five mitoses/10 HPF. The immunohistochemical findings were almost the same as the earlier operation samples. However, the Ki‐67 labeling index was 20%. In addition, tumor cells from the third specimen were more strongly and more diffusely positive for GAB1 (growth factor receptor‐bound protein 2‐associated binding protein 1) compared to those of the earlier specimens. Electron microscopy showed the presence of numerous cell processes with a dense core and clear vesicles and microtubules. GAB1 immunostaining also indicated that malignant progression might be associated with the sonic hedgehog signaling pathways. To the best of our knowledge, this is the first report of an EVN arising from the VIIIth cranial nerve with malignant progression.     

二甲双胍联合阿帕替尼对胃癌细胞的增殖抑制作用

目的 探讨二甲双胍联合阿帕替尼对胃癌BGC823细胞系的增殖抑制作用及其可能的机制。方法 MTT法检测不同浓度二甲双胍（0～30 mmol/L)、不同浓度阿帕替尼（0～60 μmol/L）及两药联合应用处理BGC823细胞24、48、72 h的增殖抑制率,结晶紫染色法检测细胞集落形成能力,流式细胞术检测细胞凋亡,western blot检测细胞中血管内皮生长因子信号通路及凋亡相关蛋白VEGFR2、PI3K、p - AKT、AKT、Bax、Bcl - 2表达水平。结果 二甲双胍和阿帕替尼单独处理BGC823后,细胞增殖抑制率均增加（P＜0.05）,联合用药产生协同作用（CI＜1）,二甲双胍和阿帕替尼单独及联合应用均能抑制细胞集落形成并使总凋亡比例增加（P＜0.05）。与对照组和单药组相比,联合用药可明显下调细胞中VEGFR2、PI3K、p - AKT、AKT、Bcl - 2蛋白的表达水平,上调Bax蛋白表达水平（P＜0.05）。结论 二甲双胍联合阿帕替尼具有协同抑制胃癌BGC823细胞增殖和诱导细胞凋亡的作用,其机制可能与抑制VEGF信号通路有关。     

STC1基因对A549细胞放射敏感性影响

目的 探讨斯钙素-1(STC1)基因对人肺癌A549细胞增殖凋亡及放射敏感性影响。方法 将合成的STC1-siRNA及不具有干扰作用的siRNA (阴性对照组)经Lipofectamine^TM2000转染人肺癌A549细胞,并设置空白组,通过Western blotting检测转染48 h后各组细胞STC1的蛋白表达。用克隆形成实验检测A549细胞经STC1-siRNA和照射处理后的增殖情况,用CCK8法检测细胞经STC1-siRNA和STC1-siRNA+8 Gy处理后的活力,用流式细胞仪检测细胞凋亡率。用Western blotting检测ki67、Bcl-2相关X蛋白(Bax)、STAT3和磷酸化的信号转导与转录因子3(p-STAT3)的蛋白表达。结果 STC1-siRNA转染的A549细胞STC1的蛋白表达低于空白组(P<0.05)。与单纯照射组比较,转染STC1-siRNA后的增敏比明显升高。与空白组比较,STC1-siRNA组细胞活力及ki67和p-STAT3的蛋白表达均降低,细胞凋亡率和Bax蛋白表达均升高;与STC1-siRNA组比较,STC1-siRNA+8 Gy组细胞活力及ki67和p-STAT3蛋白表达均降低,细胞凋亡率和Bax蛋白表达均升高(P<0.05)。结论 抑制STC1基因表达可增强非小细胞肺癌的放射敏感性并下调STAT3信号通路。     

沉默GOLPH3基因表达逆转人结肠癌细胞顺铂耐药的研究

背景与目的：化疗是结肠癌的重要治疗方法之一,其方案常含有铂类药物,而化疗耐药会影响结肠癌疗效和预后,其发生机制与基因异常表达有关。高尔基磷酸化蛋白3（Golgi phosphoprotein 3,GOLPH3）是一个癌基因,在结肠癌组织中存在过表达,可促进结肠癌细胞的增殖,与预后不良相关。目前,GOLPH3基因的高表达与结肠癌对铂类耐药的相关性尚不明确。探讨沉默GOLPH3基因逆转人结肠癌HT29细胞对顺铂的化疗耐药效应和机制。方法：HT29细胞分为5组。① 对照组：人结肠癌HT29细胞;② 转染组：siRNA-GOLPH3转染HT29细胞;③ 实验组1：经顺铂处理的HT29细胞;④ 实验组2：经顺铂处理的siRNA-GOLPH3转染HT29细胞;⑤ 实验组3：经顺铂和细胞外调节蛋白激酶（extracellular signal-regulated protein kinases,ERK）1/2抑制剂PD98059处理的HT29细胞。四甲基偶氮唑蓝（methyl thiazolyl tetrazolium,MTT）法、平板克隆形成实验检测各组结肠癌HT29细胞增殖及克隆形成能力。蛋白质印迹法（Western blot）检测GOLPH3、P-糖蛋白（P-glycoprotein,P-gp）、ERK1/2和pERK1/2蛋白的表达。结果：经顺铂处理后,实验组1、实验组2的细胞在波长490 nm处的吸光度（D）值均显著低于对照组（P<0.05）,实验组2的D₄₉₀值显著低于实验组1（P<0.001）;实验组1和实验组2的细胞集落数均显著低于对照组（P<0.01）,实验组2的细胞集落数显著低于实验组1（P<0.001）。实验组1的P-gp、GOLPH3、pERK1/2蛋白表达量显著高于实验组2（P<0.01）;实验组3的P-gp蛋白表达量较实验组1显著降低（P<0.01）。结论：沉默GOLPH3基因可通过抑制丝裂原活化蛋白激酶/细胞外信号调节激酶（mitogen-activated protein kinase/extracellular signal-regulated kinase,MAPK/ERK）信号通路逆转HT29结肠癌细胞对顺铂化疗的耐药性。     

骨髓激酶X对宫颈癌细胞增殖的影响及可能的作用机制

目的 探讨骨髓激酶X（bone marrow X-linked kinase,BMX）对人宫颈癌细胞增殖的影响及其可能的作用。方法 收集2013—2017年本院34例正常宫颈、25例原位宫颈癌和52例浸润性宫颈癌的临床标本,采用免疫组织化学方法检测不同标本中BMX的表达。转染BMX-TALEN重组质粒构建敲低BMX表达宫颈癌细胞HeLa-BMX^+/-。宫颈癌细胞HeLa-BMX^+/-和HeLa-野生型细胞分别培养于含抑制剂MK-2206和雷帕霉素完全培养基中,并以培养于含有DMSO培养基的细胞为对照组。采用MTT分析测定细胞活力,Western blot检测BMX、Akt、p-Akt、mTOR和p-mTOR表达。结果 免疫组织化学法检测结果显示,正常宫颈组织、原位宫颈癌组织及浸润性宫颈癌组织BMX阳性率差异有统计学意义（26.5% vs 68.0% vs 88.5%,χ²=34.804,P<0.001）,两两比较差异亦有统计学意义（P<0.05）。成功构建低表达BMX宫颈癌细胞HeLa-BMX^+/-。Western blot结果显示,BMX和p-Akt在HeLa-BMX^+/-细胞中的表达低于HeLa-野生型细胞（t=6.282,8.117,P<0.001）,总Akt表达水平差异无统计学意义（t=2.035,P=0.126）。与对照组比较,经MK-2206和雷帕霉素处理的HeLa-野生型及BMX+/-细胞中p-Akt和p-mTOR的表达均明显受抑制。结论 BMX可能通过PI3K/Akt/mTOR信号通路促进宫颈癌细胞增殖。     

增生性瘢痕分子信号通路研究

增生性瘢痕是临床常见的皮肤纤维增生性疾病,因伤口过度愈合而形成的。其从外观和机体功能方面均给患者带来心理和生理上的痛苦,严重者甚至影响患者自信心,使其产生自卑心理。增生性瘢痕的形成机制虽未完全清楚,但伴随着相关研究的不断深化,目前关于该病发病机制的研究已经进入到细胞、分子和基因水平。其中转化生长因子-β1信号通路、磷脂酰肌醇3激酶/蛋白激酶B/哺乳动物雷帕霉素靶蛋白信号通路、Hippo信号通路、Notch信号通路和Hedgehog信号通路参与了增生性瘢痕的形成过程,本文主要就上述信号通路在增生性瘢痕发病机制中的研究做一综述,旨在为进一步认识增生性瘢痕的发病机制提供参考。     

β-arrestin 2 attenuates lipopolysaccharide-induced liver injury via inhibition of TLR4/NF-κB signaling pathwaymediated inflammation in mice

AIM To study the role and the possible mechanism of β-arrestin 2 in lipopolysaccharide(LPS)-induced liver injury in vivo and in vitro.METHODS Male β-arrestin 2~(+/+) and β-arrestin 2~(-/-)C57 BL/6 J mice were used for in vivo experiments, and the mouse macrophage cell line RAW264.7 was used for in vitro experiments. The animal model was established via intraperitoneal injection of LPS or physiological sodium chloride solution. Blood samples and liver tissues were collected to analyze liver injury and levels of pro-inflammatory cytokines. Cultured cell extracts were collected to analyze the production of pro-inflammatory cytokines and expression of key molecules involved in the TLR4/NF-κB signaling pathway.RESULTS Compared with wild-type mice, the β-arrestin 2 knockout mice displayed more severe LPS-induced liver injury and significantly higher levels of proinflammatory cytokines, including interleukin(IL)-1β, IL-6, tumor necrosis factor(TNF)-α, and IL-10. Compared with the control group, pro-inflammatory cytokines(including IL-1β, IL-6, TNF-α, and IL-10) produced by RAW264.7 cells in the β-arrestin 2 si RNA group were significantly increased at 6 h after treatment with LPS. Further, key molecules involved in the TLR4/NF-κB signaling pathway, including phosphoIκBα and phosho-p65, were upregulated.CONCLUSION β-arrestin 2 can protect liver tissue from LPS-induced injury via inhibition of TLR4/NF-κB signaling pathwaymediated inflammation.