PTEN基因转染对人膀胱癌细胞BIU-87中P13K—Akt信号通路的影响

目的研究抑癌基因PTEN转染对人膀胱癌细胞BIU-87中P13K—Akt信号通路的作用。方法将携有PTEN基因的重组真核表达质粒pBp-PTEN转化大肠杆菌DH5=并扩增，抽提纯化质粒并进行酶切鉴定，pBp-PTEN体外转染BIU-87细胞（pBp-PTEN—BIU87），筛选稳定转染的细胞并扩增培养，以转染了空质粒pBp的BIU-87细胞（pBp—BIU87）和正常BIU-87细胞为对照，用RT—PCR检测PTEN的表达情况。将PTEN基因的真核表达质粒转染膀胱癌细胞BIU一87（pBp—PTEN—BIU87），以BIU87细胞和pBp-BIU87细胞为对照，应用Wester blot方法检测三组细胞P110（P13K的催化亚单位）、磷酸化P110、Akt和磷酸化Akt表达的情况。结果3种细胞P110和Akt蛋白总水平没有变化，但磷酸化P110和磷酸化Akt在PTEN转染细胞中的表达明显弱于对照组。结论PTEN是通过对PI3K—Akt信号传导途径的负调控而抑制肿瘤的形成。PTEN—PI3K—Akt途径可能是PTEN抑癌作用的重要机制。     

MK2206 inhibits hepatocellular carcinoma cellular proliferation via induction of apoptosis and cell cycle arrest

Background

Hepatocellular carcinoma (HCC) is commonly diagnosed at an advanced stage and has limited effective treatment options. The aberrant regulation of the phosphoinositide 3-kinase/Akt pathway in HCC makes it an attractive therapeutic target. The effect of MK2206, a novel, allosteric Akt inhibitor, on HCC cells is not yet fully understood. We hypothesized that inhibition of Akt by MK2206 would impact cellular viability.

Materials and methods

Human Huh7, Hep3B, and HepG2 cell lines were treated with 0–2 μM of MK2206 for 96 h. Cell viability was determined by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Western blot analysis was used to examine the expression level of various protein markers to assess the mechanism of drug action and proliferation inhibition.

Results

3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay showed a reduction in cellular viability by ≥55% for all cell lines (control versus 2 μM MK2206; P <0.001). Western blot analysis revealed reduction in the level of phosphorylated AKT-Ser473 with no change in AKT-thr308 expression confirming the specificity of MK2206. There was an observed reduction in caspase-9 and survivin. Importantly, there were increases in p21 and p27 along with decreased cyclinD1 expression after treatment.

Conclusions

This study demonstrates the anti-tumor activity of MK2206 in HCC cells. The observed reduction in survivin and pro-caspase 9 suggests that MK2206 induces apoptosis. However, HCC proliferation is also halted via induction of cell cycle arrest as indicated by the increase in p21 and p27 expression and decrease in cyclinD1. Importantly, the concentration needed to achieve growth inhibition in HCC is lower than that needed for other cancer types.     

病理性瘢痕中整合素链激酶、磷脂酰肌醇3激酶蛋白和mRNA表达及其临床意义

目的探讨正常皮肤、非病理性瘢痕及病理性瘢痕中整合素链激酶和磷脂酰肌醇3激酶的表达情况。方法统计整形外科病理性瘢痕40例,非病理性瘢痕12例,正常皮肤组织16例;采用免疫组织化学法和蛋白印迹及荧光实时定量PCR,检测3种组织中整合素链激酶和磷脂酰肌醇3激酶蛋白及mRNA表达情况。结果整合素链激酶蛋白在正常皮肤、非病理性瘢痕及病理性瘢痕中的阳性率分别是25．00％,41．67％,85．00％。磷脂酰肌醇3激酶蛋白在3种组织中的阳性率分别是12．50％,16．67％,80．00％;蛋白印迹及荧光实时定量PCR结果显示,与正常皮肤及非病理性瘢痕相比,病理性瘢痕中整合素链激酶、磷脂酰肌醇3激酶蛋白及mRNA表达均有统计学意义。病理性瘢痕中整合素链激酶与磷脂酰肌醇3激酶蛋白表达呈正相关（P=0．001,r=0．614）。结论整合素链激酶和磷脂酰肌醇3激酶蛋白可能通过磷脂酰肌醇3激酶／PKB信号通路参与病理性瘢痕的形成;整合素链激酶和磷脂酰肌醇3激酶蛋白协同促进病理性瘢痕的形成;整合素链激酶和磷脂酰肌醇3激酶蛋白靶向治疗阻止组织病理性瘢痕的形成有望成为可能。     

补肾壮骨方对去卵巢大鼠骨结构和骨代谢作用的研究

目的研究补肾壮骨方对骨质疏松大鼠骨结构和骨代谢的影响及其可能的作用机制。方法用SD雌性大鼠复制去卵巢骨质疏松模型,然后分别灌服补肾壮骨方水提液高剂量(1.4 g/kg)和低剂量(0.7 g/kg)12周。用生化法测定血清钙(S-Ca)、血清磷(S-P)、尿钙(U-Ca/Cr),尿磷(U-P/Cr)以及血清中高密度脂蛋白(high-density lipoprotein,HDL)、低密度脂蛋白(low-density lipoprotein,LDL)、总胆固醇(total cholesterol,TC)、甘油三酯(triglyceride,TG)的含量;Elisa法测定I型胶原氨基端前肽(procollagen I N-terminal propeptide,PINP)、I型胶原羧基端肽(collagen I carboxyl terminal peptide,CTX-I)、尿脱氧吡啶啉(deoxypyridine,DPD)、骨钙素(osteocalcin,OCN)的含量;用放免法测定血清碱性磷酸酶(alkaline phosphatase,ALP)的活性;用双能X线(DEXA)法、Viva CT和万能试验机测定骨密度、骨微结构和骨生物力学特性;用Western blot法测定骨组织蛋白酶(cathepsin)K表达。结果补肾壮骨方水提液能升高血清中的钙、磷、HDL-C和PINP的含量,降低血清中TC、TG、LDL、ALP、OCN和CTX-I及尿液中的钙、磷、DPD的含量。同时,补肾壮骨方水提液可以升高去卵巢大鼠股骨的骨密度,改善骨微结构,增加骨强度,降低胫骨Cathepsin K的表达水平。结论补肾壮骨方水提液能够抑制去卵巢大鼠的骨量丢失和骨强度下降,改善去卵巢大鼠的骨代谢,其作用机制可能与抑制Cathepsin K的表达有关。     

The role of PI3K/Akt signaling pathway in non‐physiological shear stress‐induced platelet activation

The PI3K/Akt signaling pathway has been implicated in playing an important role in platelet activation during hemostasis and thrombosis involving platelet‐matrix interaction and platelet aggregation. Its role in non‐physiological shear stress (NPSS)‐induced platelet activation relevant to high‐shear blood contacting medical devices (BCMDs) is unclear. In the context of blood cells flowing in BCMDs, platelets are subjected to NPSS (>100 Pa) with very short exposure time (<1 s). In this study, we investigated whether NPSS with short exposure time induces platelet activation through the PI3K/Akt signaling pathway. Healthy donor blood treated with or without PI3K inhibitor was subjected to NPSS (150 Pa) with short exposure time (0.5 s). Platelet activation indicated by the surface P‐selectin expression and activated glycoprotein (GP) IIb/IIIa was quantified using flow cytometry. The phosphorylation of Akt, activation of the PI3K signaling, was characterized by western blotting. Changes in adhesion behavior of NPSS‐sheared platelets on fibrinogen, collagen, and von Willebrand factor (vWF) were quantified with fluorescent microscopy by perfusing the NPSS‐sheared and PI3K inhibitor‐treated blood through fibrinogen, collagen, and vWF‐coated microcapillary tubes. The results showed that the PI3K/Akt signaling was involved with both NPSS‐induced platelet activation and platelet‐matrix interaction. NPSS‐sheared platelets exhibited exacerbated platelet adhesion on fibrinogen, but had diminished platelet adhesion on collagen and vWF. The inhibition of PI3K signaling reduced P‐selectin expression and GPIIb/IIIa activation with suppressed Akt phosphorylation and abolished NPSS‐enhanced platelet adhesion on fibrinogen in NPSS‐sheared blood. The inhibition of PI3K signaling can attenuate the adhesion of unsheared platelets (baseline) on collagen and vWF, while had no impact on adhesion of NPSS‐sheared platelets on collagen and vWF. This study confirmed the important role of PI3K/Akt signaling pathway in NPSS‐induced platelet activation. The finding of this study suggests that blocking PI3K/Akt signaling pathway could be a potential method to treat thrombosis in patients implanted with BCMDs.     

维生素K2联合维生素D3治疗青壮年早期膝骨关节炎的研究

目的探讨维生素K2联合维生素D3治疗青壮年早期膝骨关节炎的作用。 方法2016年1月至2017年6月广州医科大学附属第二医院骨外科门诊因膝关节疼痛的患者共387例。符合早期膝骨关节炎(KOA)的青壮年患者132例,均给予相同剂量的维生素K2和维生素D3(VD)口服,随访6个月,通过观察服药前后血清25-OH-VD、血清总Ⅰ型胶原氨基端延长肽(P1NP)检测、视觉模拟评分(VAS)及股四头肌肌力的比较,维生素K2和维生素D3治疗前后各指标采用配对t检验评价治疗效果。 结果随访6个月后,血清25-OH-VD(t ＝ 2.664)、血清P1NP(t＝3.265 )的水平及股四头肌肌力(最大肌力t ＝3.005;平均肌力t ＝2.564)均较用药前增加(均为P<0.05),总体VAS评分较用药前下降( t＝3.762,P<0.05)。同时治疗前发现其中33例患者膝关节MRI检查中提示胫骨平台或股骨内侧髁存在不同程度的软骨丢失和骨髓水肿。 结论维生素K2和维生素D3联合应用能改善青壮年膝骨关节炎患者的骨营养代谢,并促进成骨作用从而改善膝关节疼痛症状和活动能力。因此对于青壮年KOA,应该早期干预治疗,从而起到抑制作用。     

黄芩素通过抑制PI3K/AKT/mTOR通路诱导膀胱癌细胞凋亡

目的 研究黄芩素对膀胱癌细胞的作用及机制。 方法 膀胱癌细胞T24和5637经黄芩素(处理组)或二甲基亚砜(对照组)处理后,3-(4,5-二甲基噻唑-2)-2,5-二苯基四氮唑溴盐(MTT)以及胸腺嘧啶核苷类似物(EdU)插入实验检测细胞增殖和DNA复制速率;划痕实验和Transwell实验检测细胞的迁移和侵袭能力;流式细胞技术检测细胞周期和细胞凋亡水平;Western blotting检测PI3K/AKT/mTOR信号通路蛋白、B淋巴细胞瘤-2(Bcl-2)和B淋巴细胞瘤-2相关X蛋白(Bax)等蛋白的表达水平;裸鼠成瘤实验检测黄芩素对于体内膀胱癌细胞增殖能力的影响。 结果 黄芩素可以在体内和体外抑制膀胱癌细胞的增殖速率,高浓度黄芩素体外抑制率可达80%以上,体内抑制率约50%。黄芩素可以减缓DNA复制并降低肿瘤细胞的迁移和侵袭能力,诱导细胞停滞在G₀/G₁期,发生细胞凋亡,与对照组相比差异有统计学意义。黄芩素处理后,PI3K的表达以及AKT和mTOR的磷酸化水平降低,Bax/Bcl-2的比值升高。 结论 黄芩素通过抑制PI3K/AKT/mTOR信号通路抑制膀胱癌细胞增殖,发生周期阻滞,诱导细胞凋亡。     

羟基红花黄色素A对卵巢癌细胞PI3K/Akt信号通路的影响

目的研究羟基红花黄色素A(HSYA)对人顺铂耐药的卵巢癌A2780/DDP细胞株顺铂耐药性的逆转作用及具体机制。方法培养A2780/DDP细胞,接种至20只BALB/C雌性裸鼠,按随机数字表法分为对照组、红花组、顺铂组和联合组,每组5只,均采用腹腔注射给药的方式,对照组予0.9%氯化钠溶液,顺铂组按3mg/kg剂量给予顺铂,红花组按1.1g/kg给予HSYA,联合组予HSYA(1.1g/kg)联合顺铂(3mg/kg),每3天给药1次,连续给药4周。第5周后处死小鼠,解剖取瘤记录瘤重并计算抑瘤率,HE染色观察各组肿瘤的病理改变,Western blot检测Akt、p-Akt蛋白表达。结果对照组瘤重(4.71±0.17)g,顺铂组瘤重(3.53±0.28)g,抑瘤率25.08%,红花组瘤重(4.54±0.25)g,抑瘤率3.61%,联合组瘤重(2.76±0.17)g,抑瘤率41.36%。与对照组和顺铂组相比,联合组的肿瘤质量下降(P0.05),抑瘤率明显增加(P0.05);HE染色显示,与顺铂组比较联合组肿瘤坏死程度更高;Western blot结果示,对照组Akt蛋白相对表达水平为(0.61±0.11),顺铂组为(0.62±0.09),红花组为(0.42±0.10),联合组为(0.44±0.07)。与对照组比较,顺铂组Akt、p-Akt蛋白表达无统计学差异(P0.05),与对照组与顺铂组比较,红花组与联合组的Akt、p-Akt蛋白表达较低,差异有统计学意义(P0.05)。结论 HSYA可能通过下调PI3K/AKT通路的关键组分Akt、p-Akt蛋白,来增强A2780/DDP对顺铂的化疗敏感性,逆转顺铂耐药。     

成纤维细胞生长因子21对缺氧复氧心肌细胞的保护作用及机制研究

【摘要】 目的 探讨成纤维细胞生长因子21（FGF21）对缺氧复氧（H/R）心肌细胞的保护作用及对PI3K/AKT通路的影响。方法 重组腺病毒载体Ad FGF21诱导原代心肌细胞过表达FGF21。腺病毒转染心肌细胞后构建H/R损伤模型（3h缺氧联合3h复氧）。实验分为对照组（Con组）、H/R组、H/R+Ad GFP组、H/R+Ad FGF21组4组。心肌细胞存活率评估细胞损伤程度;SOD/MDA检测联合DHE荧光染色评估氧化应激反应（ROS）;流式细胞术评估细胞凋亡;Western blot检测相关蛋白水平。在机制探讨实验中给予PI3K/AKT抑制剂（LY294002）进行干预。结果 与Con组相比,H/R损伤后FGF21蛋白表达显著下调,并伴随心肌细胞活性降低、ROS与凋亡反应激活。腺病毒介导的心肌细胞过表达FGF21能够明显抑制H/R损伤,表现为细胞活力、ROS与凋亡反应均有不同程度改善。FGF21心肌细胞过表达能够增加PI3K/AKT磷酸化水平,而抑制PI3K/AKT通路后FGF21过表达介导的细胞保护功能被逆转。结论 FGF21主要通过PI3K/AKT依赖性途径改善心肌细胞H/R损伤。