雷公藤红素抑制MGC - 823细胞增殖和迁移及诱导凋亡

目的 探索雷公藤红素对MGC - 823细胞的增殖，迁移及诱导凋亡的作用，并探讨其作用机制。方法 0、1、2、4、6、8、12 μM雷公藤红素作用于MGC - 823细胞，采用MTT法检测增殖比率。0、1、2和4 μM雷公藤红素作用于MGC - 823细胞0、24、48和72 h，显微镜下观察细胞形态，采用细胞划痕实验检测细胞迁移能力，流式细胞术检测细胞凋亡，western blot法检测细胞中凋亡相关蛋白Bcl - 2、Bax、Akt、p - Akt等的表达水平。结果 经雷公藤红素作用后，MGC - 823细胞的增殖率均下降（P＜0.05）；细胞数量减少，体积缩小，皱缩变圆，部分不再贴壁，细胞核缩小；细胞迁移率减小（P＜0.05）；早期凋亡率增加（P＜0.05）；MGC - 823细胞中Bax表达升高，Bcl - 2和p - Akt表达降低（P＜0.05）。结论 雷公藤红素对MGC - 823细胞的增殖和迁移有抑制作用，并诱导其凋亡。     

Inhibition of Frizzled-2 by small interfering RNA protects rat hepatic BRL-3A cells against cytotoxicity and apoptosis induced by Hypoxia/Reoxygenation

Frizzled-2 plays an important role in maintaining normal hepatic cell functionality. This study aimed to investigate the role of inhibition of Frizzled-2 in protecting rat liver BRL-3A cells from Hypoxia/Reoxygenation (H/R). In vitro H/R hepatic cell model was established by culturing BRL-3A cells under H/R condition. Frizzled-2 siRNA was transfected into BRL-3A cells to inhibit Frizzled-2 signaling. Wnt5a and Frizzled-2 were significantly increased in BRL-3A cells upon H/R treatment. H/R treatment induced cell cytotoxicity, the early apoptosis rate and the intracellular Ca²⁺ level in BRL-3A cells while silencing frizzled-2 gene decreased the H/R induced cell cytotoxicity, apoptosis and intracellular Ca²⁺ level. In vivo mice study further showed the up-regulation of Frizzled-2/Wnt 5 pathway and cleaved Caspase-3 expression in liver tissues under ischemia and reperfusion injury (IRI). In summary, inhibition of Frizzled-2 by its siRNA may protects BRL-3A cells by attenuating the H/R induced cell cytotoxicity and apoptosis.     

树突状细胞相关的C型凝集素1在小鼠肾缺血再灌注中的作用及其机制

目的探究树突状细胞相关的C型凝集素-1(Dectin-1)在小鼠肾缺血再灌注损伤中的作用及其机制。方法C56BL/6雄性小鼠60只,随机数字表法分为假手术组、肾缺血再灌注损伤(RIRI)组、生理盐水组、昆布多糖(LAM)低剂量组(20 mg/kg)、LAM中剂量组(40 mg/kg)、LAM高剂量组(80 mg/kg)。采集小鼠血液标本,测定血清肌酐(Cr)及尿素氮(BUN)水平;苏木精-伊红(HE)染色评估各组小鼠肾组织病理学改变;原位缺口末端标记法(TUNEL)法检测细胞凋亡数量;定时定量反转录-聚合酶链反应(RT-qPCR)法检测白细胞介素(IL)-1β、半胱氨酰天冬氨酸特异性蛋白酶(Caspase)-1、核苷酸结合寡聚化结构域样受体3(NLRP3)、凋亡相关微粒蛋白(ASC)的mRNA水平;蛋白质印迹法(Western blot)检测葡萄糖调节蛋白78(GRP78)、磷酸化真核细胞翻译启始子2α(p-eIF2α)/真核细胞翻译启始子2α(eIF2α)、C/EBP同源蛋白(CHOP)的蛋白水平。组间比较采用t检验。结果RIRI组小鼠BUN及Cr水平明显高于假手术组(Cr 157.23±15.90比15.97±0.70,t=23.963,P<0.05;BUN 16.66±0.87比4.34±0.49,t=28.217,P<0.05),LAM组小鼠BUN及Cr水平明显低于假手术组(Cr 123.70±9.66比103.33±3.95比79.90±4.04比157.23±15.90,t=6.653、7.159、12.861,P值均<0.05;BUN 11.56±0.80比9.37±0.81比7.13±0.63比16.66±0.87,t=5.427、13.593、34.028,P值均<0.05),差异均有统计学意义;LAM组小鼠凋亡细胞明显低于RIRI组(14.44±1.91比40.89±4.53,t=10.137,P<0.05);LAM组小鼠IL-1β、Caspase-1、NLRP3、ASC的信使RNA(mRNA)水平明显低于RIRI组,差异有统计学意义(IL-1β为2.56±0.09比4.98±0.44,t=7.932,P<0.05;Caspase-1为1.77±0.12比4.00±0.22,t=12.160,P<0.05;NLRP3为2.43±0.28比4.71±0.28,t=16.474,P<0.05;ASC为1.99±0.16比3.14±0.17,t=15.977,P<0.05);LAM组小鼠GRP78、p-eIF2α/eIF2α、CHOP蛋白水平明显低于RIRI组,差异均有统计学意义(GRP78为0.472±0.026比1.215±0.073,t=26.501,P<0.05;eIF2α/p-eIF2α为0.697±0.016比0.871±0.028,t=9.877,P<0.05;0.621±0.035比1.086±0.115,t=5.419,P<0.05)。结论Dectin-1拮抗剂Laminarin可减轻小鼠肾缺血再灌注损伤,其机制可能与抑制细胞凋亡、焦亡及内质网应激有关。     

雷帕霉素对去甲氧柔红霉素诱导急性髓系白血病THP-1细胞凋亡的影响

目的:探讨雷帕霉素（Rapa）对去甲氧柔红霉素（IDA）诱导急性髓系白血病THP-1细胞凋亡的影响及其分子机制。方法:分别用10、20、40、80 nmol/L Rapa处理THP-1细胞1 h，另设未经Rapa处理的细胞。采用蛋白质印迹法检测THP-1细胞自噬标志物LC3蛋白的转换情况（LC3Ⅱ/LC3Ⅰ），采用流式细胞术检测细胞凋亡，确定Rapa处理浓度。用不同浓度IDA作用THP-1细胞24 h，采用CCK-8法检测IDA对THP-1细胞的增殖抑制率，计算半数抑制浓度（ IC50）。以低于 IC50的IDA作用Rapa处理或未处理的THP-1细胞24 h，CCK-8法检测细胞增殖抑制率，流式细胞术检测细胞凋亡情况，实时荧光定量聚合酶链反应检测自噬相关基因Beclin-1、LC3和p62的表达变化，蛋白质印迹法检测自噬标志物LC3蛋白的转换情况。 结果:20 nmol/L Rapa处理的THP-1细胞LC3Ⅱ/LC3Ⅰ高于未处理的细胞（ P=0.002 4）；80 nmol/L Rapa处理的细胞凋亡率高于未处理的细胞（ P=0.007 3）。根据蛋白质印迹法和流式细胞术检测结果，选取20 nmol/L Rapa作为预处理浓度。IDA对THP-1细胞作用24 h的 IC50为59.874 nmol/L。50 nmol/L IDA作用24 h后，Rapa预处理的THP-1细胞增殖抑制率[（69.67±5.03）%比（41.67±3.51）%]和细胞凋亡率[（74.35±4.83）%比（41.25±5.24）%]均高于未预处理的细胞（均 P<0.05）；Rapa预处理的THP-1细胞Beclin-1、LC3 mRNA表达水平及LC3Ⅱ/LC3Ⅰ均高于未预处理的细胞，p62 mRNA表达水平低于未预处理的细胞（均 P<0.05）。 结论:Rapa能增强较低剂量IDA诱导的THP-1细胞凋亡，此效应可能是通过其引起THP-1细胞过度自噬实现的。     

Effect of Diacerein on HOTAIR/IL-6/STAT3, Wnt/β-Catenin and TLR-4/NF-κB/TNF-α axes in colon carcinogenesis

Colorectal cancer (CRC) is a common malignancy with high mortality and poor prognosis. Diacerein (DIA) is an anti-inflammatory used for treatment of osteoarthritis. We delineated some underlying molecular mechanisms of DIA’s anti-carcinogenic effect in CRC using in vivo and in vitro models. Human Caco-2 cells were treated with DIA followed by MTT and Annexin V assays and CRC was experimentally induced using 1,2-dimethylhydrazine. DIA (50 mg/kg/day, orally) was administrated for 8 weeks. The MTT assay confirmed cytotoxic effect of DIA in vitro and Annexin V confirmed its apoptotic effect. DIA resulted in regression of tumour lesions with reduced colonic TLR4, NF-κB and TNF-α protein levels and down-regulated VEGF expression, confirming anti-angiogenic impact. DIA triggered caspase-3 expression and regulated Wnt/β-Catenin pathway, by apparently interrupting the IL-6/STAT3/ lncRNA HOTAIR axis. In conclusion, DIA disrupted IL-6/STAT3/ lncRNA HOTAIR axis which could offer an effective therapeutic strategy for the management of CRC.     

Hepatitis C virus-specific cytotoxic T cell response restoration after treatment-induced hepatitis C virus control

Hepatitis C virus(HCV)-specific cytotoxic T cell(CTL) response plays a major role in viral control during spontaneous infection resolution. These cells develop an exhausted and pro-apoptotic status during chronic onset, being unable to get rid of HCV. The role of this response in contributing to sustained viral response(SVR) after anti-HCV is controversial. Recent studies show that after successful interferon-based anti-HCV treatment, HCV traces are still detectable and this correlates with a peak of HCV-specific CTL response activation, probably responsible for maintaining SVR by subsequent complete HCV clearing. Moreover, SVR patients’ serum is still able to induce HCV infection in na?ve chimpanzees, suggesting that the infection could be under the control of the immune system after a successful treatment, being transmissible in absence of this adaptive response. At least theoretically, treatmentinduced viral load decrease could allow an effective HCV-specific CTL response reestablishment. This effect has been recently described with anti-HCV interferonfree regimes, based on direct-acting antivirals. Nevertheless, this is to some extent controversial with interferon-based therapies, due to the detrimental immunoregulatory α-interferon effect on T cells. Moreover, HCV-specific CTL response features during anti-HCV treatment could be a predictive factor of SVR that could have clinical implications in patient management. In this review, the recent knowledge about the role of HCV-specific CTL response in the development of SVR after anti-HCV treatment is discussed.     

Effect of UVC radiation on mouse fibroblasts deficient for FAS-associated protein with death domain

Purpose: Ultraviolet (UV) radiation-induced apoptosis enabled us to study the mechanism of DNA damage and to investigate how cells avoid consequences of damaged DNA. Cells with extensive DNA damage activate extrinsic and intrinsic pathways of apoptosis. The extrinsic pathway is coupled to a FAS-associated protein with death domain (FADD), an adaptor protein molecule necessary for mediating apoptotic signals through the cell.

Materials and methods: Viability and apoptosis of wild-type and FADD-deficient mouse embryonic fibroblasts were investigated 1, 3, 24 and 48?h after exposure to three doses (50, 75 and 300 J/m²) of UVC radiation. Morphological changes were observed using DNA binding dyes (Hoechst and propidium iodide) while biochemical changes were monitored using immunodetection of the poly (ADP-ribose) polymerase (PARP) protein cleavage and caspase-3 activity assay.

Results: Results showed that the difference in cell death response between wild-type and FADD-deficient cells depended on dose and incubation time after exposure to UVC radiation. FADD-deficient cells are more sensitive to UVC radiation. Even though FADD-deficient cells lack an adapter protein of apoptotic extrinsic pathway, higher doses of UVC triggered their apoptotic response, while wild-type cells die mainly due to necrosis. A different pattern of caspase 3 activity and PARP cleavage was observed 24?h after radiation between two cell lines confirming higher apoptotic response in FADD-deficient cells.

Conclusions: Wild-type cells can execute apoptosis via both, the mitochondrial and the receptor-mediated pathway whereas FADD-deficient cells can only activate the intrinsic pathway. There is a difference in UVC radiation response between two cell lines indicating the role of FADD in the selection of cell death modality.