致敏树突状细胞抗乳腺癌作用的实验研究

目的 探讨负载肿瘤抗原DC诱导的CTLs对乳腺癌细胞的杀伤作用.方法 以负载肿瘤细胞抗原的DCs体外诱导CTLs,用ELISA法检测IFN-γ和IL-12的表达水平,用LDH法检测CTL对乳腺癌细胞的杀伤作用.结果 负载肿瘤抗原DC组IFN-γ和IL-12的浓度高于未致敏DC组、抗原组及单核细胞对照组(P＜0.05),且负载抗原DC组所刺激的CTLs的杀伤作用也强于未致敏DC组、抗原组及单个核细胞组(P＜0.01)及对照的HT-29组(P＜0.01).结论 采用乳腺癌细胞冻融抗原体外致敏DC,诱导产生肿瘤抗原特异性CTLs具有显著的抑瘤效应,实验证明致敏DC治疗乳腺癌是一种有效的方法 ,有望成为乳腺癌免疫治疗的新疗法.     

甲胎蛋白表位肽锚定的DC–CIK对AFP+肝癌细胞抗肿瘤活性的影响

目的:探讨甲胎蛋白(AFP)表位肽锚定的树突状细胞(DC)与细胞因子诱导的杀伤细胞(CIK)细胞共培养对AFP+的肝癌HepG2细胞杀伤活性的影响。方法:用AFP与Ii融合多肽锚定体外诱导的健康志愿者外周血单个核细胞(PBMCs)产生的DC,用肿瘤坏死因子–α(TNF–α)诱导DC成熟后,与CIK细胞共培养9 d。采用流式细胞术检测共培养体系中CD3+CD4+、CD3+CD8+、CD3+CD56+、CD3+CD25+表型细胞比例,用乳酸脱氢酶(LDH)方法和酶联免疫吸附试验(ELISA)试剂盒检测共培养细胞对肝癌细胞HepG2的杀伤作用以及培养上清液中白细胞介素(IL)–12和干扰素(IFN)–γ水平。结果:与未负载AFP–Ii锚定抗原的DC–CIK比较,AFP锚定抗原的DC–CIK体系中CD3+CD8+、CD3+CD56+双阳性分子表达增高,对HepG2细胞具有更强的杀伤活性,差异具有统计学意义(P 0.01),且其上清液中检测到的IL–12和IFN–γ较对照组高,差异具有统计学意义(P 0.01)。结论:AFP锚定抗原的DC细胞能显著加强CIK细胞对肝癌细胞系的抗肿瘤效应。     

激发型CD28单抗参与诱导的CIK对乳腺MDA-MB-231、MCF-7细胞的杀伤作用研究

目的观察激发型CD28单抗参与诱导的杀伤细胞(CIK)的增殖能力、表型特征及对乳腺癌MDA-MB-231、MCF-7细胞株的杀伤作用。方法制备鼠抗人激发型CD28单抗,采用激发型CD28单抗参与CIK的诱导,观察CIK细胞的增殖能力及表型特征;采用CCK-8法检测激发型CD28单抗参与诱导的CIK对乳腺癌MDA-MB-231、MCF-7细胞株的杀伤率,采用流式细胞术检测乳腺癌细胞的凋亡率。结果激发型CD28单抗能明显促进CIK细胞的体外增殖且能明显上调具有肿瘤杀伤活性的T细胞比例;CCK8检测发现,激发型CD28单抗诱导的CIK对乳腺癌细胞株MDA-MB-231、MCF-7的杀伤率均高于对照组(P均0.05),且杀伤率随效靶比升高,并确定20∶1为最终效靶比;流式细胞术检测发现,加入激发型CD28单抗诱导的CIK,可提高乳腺癌细胞株MDA-MB-231、MCF-7的凋亡率及坏死率(P均0.05)。结论激发型CD28单抗参与诱导的CIK能明显提高CIK的增殖能力及上调具有肿瘤杀伤活性的T细胞比例,增强对乳腺癌细胞的杀伤能力,可能为乳腺癌的免疫治疗提供新思路。     

中药多糖与过继免疫联合治疗卵巢癌

目的:观察比较中药多糖干预后的多种细胞因子诱导的杀伤细胞(CIK)细胞在不同条件下特异性杀伤卵巢癌SKOV3细胞的效果,探讨中药与过继免疫联合治疗卵巢癌的可行性。方法:实验分4组,CIK组、PBOC-CIK组、SKOV3Ag-PBDC-CIK组及SKOV3Ag-ADC-CIK组。联合猪苓多糖(100 mg.L-1)、茯苓多糖(100 mg.L-1)、黄芪多糖(100 mg.L-1)及多种细胞因子对卵巢癌患者外周血CIK细胞进行体外诱导和扩增,以卵巢癌细胞株SKOV3冻融抗原致敏外周血与腹水来源的DC细胞,比较单纯CIK、未经抗原负载的外周血树突状细胞(DC)活化的CIK、经抗原负载的外周血DC活化的CIK、经抗原负载的腹水DC活化的CIK对SKOV3细胞的杀伤作用,并动态观察CIK细胞的增殖情况。结果:①CIK与DC共培养可显著增加CIK增殖倍数(P<0.01);②中药多糖干预后CIK对SKOV3卵巢癌细胞株有明显杀伤作用,且杀伤率随效靶比增加而提高,细胞杀伤率分别为(9.12±0.21)%,(10.15±0.27)%,(11.20±0.34)%和(12.73±0.43)%(P<0.05);③SKVO3冻融抗原负载的外周血DC可显著增加CIK特异性杀伤卵巢癌SKOV3细胞的能力,杀伤率显著高于未负载抗原外周血DC活化的CIK细胞和单纯CIK细胞(P<0.05或P<0.01);④腹水来源DC负载抗原后所活化的CIK细胞对SKOV3细胞杀伤率,与负载抗原的外周血来源DC活化的CIK无明显差异。结论:经SKOV3肿瘤细胞冻融抗原冲击致敏的DC,可促进中药多糖干预后CIK细胞扩增,增强CIK细胞对SKOV3卵巢癌细胞的杀伤作用,且卵巢癌腹水可作为过继免疫治疗中效应细胞的一个重要来源。     

肺积方扶正组份对中晚期肺癌患者自体CIK细胞生物学活性的影响

目的:探讨肺积方扶正组份对中晚期肺癌患者自体细胞因子诱导的杀伤细胞增殖及杀瘤活性的影响。方法:选取中晚期肺癌患者30例,抽取外周血并分离单个核细胞,在常规加入CIK细胞时,实验组加入肺积方扶正组份含药血清,对照组加生理盐水小鼠血清。检测并比较两组CIK细胞免疫表型、CIK细胞杀伤活性。结果:(1)在细胞培养的第14天,实验组和对照组细胞中CD3~+、CD56~+细胞百分比比较有差异,P0.05。(2)效靶比为5∶1时,实验组和对照组CIK细胞杀伤活性分别是(13.42±3.74)%和(12.78±3.75)%,P0.05;效靶比为10∶1时,实验组和对照组CIK细胞杀伤活性分别是(24.42±4.67)%和(21.89±5.32)%,P0.01;效靶比为20∶1时,实验组和对照组CIK细胞杀伤活性分别是(54.65±8.15)%和(50.06±9.12)%,P0.05。结论:肺积方拆方之扶正组份天冬、薏苡仁、北沙参有助于提高CIK细胞增殖及杀瘤活性,可能在提高免疫力中起重要作用。     

黄芪多糖诱导成熟的树突状细胞肿瘤疫苗体外抗肿瘤作用的实验研究

目的探讨经黄芪多糖（astragalus polysacharin,APS）诱导成熟的树突状细胞（dendritic cell,DC）肿瘤疫苗体外抗肿瘤作用及其机制。方法分离人外周血单个核细胞（peripheral blood mononuclear cell,PBMC）,制备DC细胞,加入营养液体外诱导为未成熟的DC细胞,培养第5天,黄芪多糖组加入终浓度为100μg/mL的黄芪多糖,细胞因子组加入终浓度为20 ng/mL重组人肿瘤坏死因子（rhTNF）-α诱导DC成熟,观察树突状细胞形态及表型变化;成熟DC以SGC-7901肿瘤抗原致敏,与同种异体T细胞共培养,采用MTT法检测T淋巴细胞增殖功能,E LISA法检测共培养上清IL-12、IFN-γ水平;经DC激活的细胞毒性T淋巴细胞（cytotoxic lymphocyte,CTL）细胞与SGC-7901肿瘤细胞共培养,采用LDH释放法检测CLT对靶细胞特异性杀伤能力。结果黄芪多糖诱导的DC经形态学观察和表型鉴定,符合成熟DC的特征。黄芪多糖诱导成熟的DC能刺激同种异体T淋巴细胞增殖,T细胞增殖指数随刺激细胞与效应细胞比值的增加而增加（P〈0.05）;DC与T细胞共培养上清IL-12、IFN-γ的水平显著增加且呈时间依赖性（P〈0.05）;经致敏DC激活的CTL能显著杀伤肿瘤细胞,随着效靶比的增加,杀伤作用增强。结论黄芪多糖可在体外诱导DC成熟,并促进其抗原递呈能力,有效活化CTL,增强机体抗肿瘤功能。     

参芪扶正注射液对脐血CIK细胞体外增殖及杀瘤活性的影响

目的观察参芪扶正注射液对脐血细胞因子诱导的杀伤细胞(CIK细胞)体外增殖及杀瘤活性的影响。方法用脐血单个核细胞,诱导分化CIK细胞,分为4组。细胞因子组加入γ干扰素(IFN-γ)、白细胞介素1α(IL-1α)、白细胞介素2(IL-2)、CD3单抗细胞因子;参芪扶正注射液组:加入参芪扶正注射液;细胞因子+参芪扶正注射液组:加入参芪扶正注射液﹑IFN-γ、IL-1α、IL-2、CD3单抗细胞因子;对照组只加培养液。培养12天后CIK细胞达到增殖高峰期,用流式细胞仪检测细胞表型和增殖能力,MTT法检测CIK细胞对K562细胞的杀伤作用,ELISA法检测CIK细胞分泌的细胞因子IL-2、IFN-γ、肿瘤坏死因子α(TNF-α)水平。结果对脐血CIK细胞体外增殖的影响,在培养12天时,参芪扶正注射液组与细胞因子组比较差异无统计学意义(P>0.05),细胞因子+参芪扶正注射液组与细胞因子组相比差异有统计学意义(P<0.01);CIK细胞对K562细胞的杀伤作用,各实验组与对照组相比差异有统计学意义(P<0.01),参芪扶正注射液组CIK细胞在12、16天时分泌IL-2、IFN-γ、TNF-α因子水平优于对照组(P<0.01)。结论参芪扶正注射液对脐血CIK细胞既有显著的增殖和杀瘤作用,又可促进脐血CIK细胞分泌IFN-γ、IL-2和TNF-α。     

大量培养诱导乳腺癌患者自体DC和CIK细胞的研究

目的探讨获得大量乳腺癌患者自体树突状细胞(dendritic cells,DCs)和细胞因子诱导的杀伤细胞(cytokine-induced cells,CIK细胞)的可行性。方法实验组,乳腺癌患者经外周血干细胞动员,取50mL外周血分外周血单个核细胞(PBMC),用AIM-V无血清培养基培养DCs和CIK,并设健康人对照组,用RPMI1640完全营养培养基。结果实验组PBMC产出2×108个并诱导出1.2×107个DCs和2×109个CIK细胞,显著高于对照组(P<0.01)。DCs的CD86、CD11c和HLA-DR分子都有较高表达,CIK细胞CD3 、CD56 双阳性细胞达到14.41%。细胞毒实验提示CIK细胞有强大的杀瘤活性。结论乳腺癌患者经外周血干细胞动员,用AIM-V无血清系统培养,少量外周血可诱导大量优质自体DCs和CIK细胞。     

六味地黄汤对细胞诱导的杀伤细胞体外扩增及抗骨肉瘤细胞的影响

目的:探讨六味地黄汤对不同人群来源的多种细胞诱导的杀伤细胞(cytokine-induced killer cells,CIK)细胞增殖及其对骨肉瘤细胞毒活性的作用。方法:实验分为6组,通过向10名健康男性的外周血单个核细胞(PBMC)中分别加入在白介素-2(IL-2)、干扰素-γ(IFN-γ)、白介素-1(IL-1)、抗CD3单克隆抗体(CD3McAb)及不同浓度中药血清,诱导CIK细胞,检测其形态及表型,测定CIK细胞对骨肉瘤细胞的细胞毒性作用。结果:单纯中药含药血清对CIK无诱导作用,细胞因子联合含药血清培养的CIK增殖倍数明显高于无药血清和无血清培养(P<0.05),而在联合培养中中剂量中药的CIK增殖速度高于低和高剂量血清培养(P<0.05),且对CIK细胞CD3+CD5 6+表达最为稳定;各组对骨肉瘤细胞均有一定杀伤作用,其中联合培养含药血清中剂量培养CIK细胞对骨肉瘤细胞杀伤效果最好。结论:单纯六味地黄汤含药血清对CIK细胞基本无诱导作用,联合细胞因子有促进CIK细胞的体外扩增作用,对骨肉瘤细胞有较强的杀伤活性,但与浓度相关。     

香菇多糖对荷瘤鼠血清IL-10、TNF-α和肿瘤DC表达的影响

目的探讨香菇多糖对S180荷瘤鼠血清IL-10、TNF-α水平及肿瘤中DC表达的影响。方法检测各组小鼠血清TNF-α、IL-10水平;通过S100免疫组化标记,计算S100+细胞在参照物(肿瘤)中所占面积百分比;计算DC密度。结果肿瘤模型组血清IL-10、TNF-α均升高,使用香菇多糖后,IL-10、TNF-α回复接近正常组水平,与肿瘤模型组比较,差异有统计学意义(P<0.05)。香菇多糖实验组肿瘤细胞异型性较小,瘤巨细胞明显减少,其间的S100+细胞面积百分比和DC密度均高于肿瘤对照组(P<0.01)。结论香菇多糖能改善DC的功能,减少荷瘤机体(和/或肿瘤)免疫抑制因子的分泌,从而抑制肿瘤的发展。     

Effects of Bupleurum falcatum and its combination with an angiotensin II receptor blocker on cytokine and chemokine expression in human mesangial cells

This study aimed to investigate the inhibitory effect of Bupleurum falcatum and its combination with angiotensin II receptor blocker (ARB) on cytokine and chemokine production in cultured human mesangial cells. Human mesangial cells were isolated and cultured in Dulbecco's modified Eagle's medium culture medium. Bupleurum falcatum, ARB, and the combination of the two were added to human mesangial cells. Cytokine and chemokine levels were analysed using an enzyme‐linked immunosorbent assay. There were no significant differences in the expression of IL‐1ß, IL‐2 or TNF‐a between controls and the experimental groups. However, IL‐11 and monocyte chemoattractant protein‐1 (MCP‐1) levels were significantly reduced in response to ARB, Bupleurum falcatum, or their combination when compared with controls. IL‐8 expression was reduced significantly only in cells treated with ARB. Both Bupleurum falcatum and ARB treatments alone reduced the cytokine concentration, but there was not a stronger reduction when the two drugs were combined. It was shown that Bupleurum falcatum inhibited cytokine production in human mesangial cells. However, there were no additive effects on the suppression of cytokine production when Bupleurum falcatum was combined with ARB. Further studies are needed to elucidate the renoprotective effects of Bupleurum falcatum. Copyright © 2009 John Wiley & Sons, Ltd.     

Aqueous extracts from Menyanthes trifoliate and Achillea millefolium affect maturation of human dendritic cells and their activation of allogeneic CD4+ T cells in vitro

Ethnopharmacological relevance: Menyanthes trifoliate and Achillea millefolium have been used in traditional medicine to ameliorate chronic inflammatory conditions. The aim of this study was to identify the effects of ethanol and aqueous extracts of Menyanthes trifoliate and Achillea millefolium on maturation of dendritic cells (DCs) and their ability to activate allogeneic CD4⁺ T cells.

Materials and methods

Human monocyte-derived DCs were matured in the absence or presence of lyophilised aqoueous or ethanol extracts from Menyanthes trifoliate or Achillea millefolium and their expression of surface molecules analysed with flow cytometry and cytokine secretion measured by ELISA. DCs matured in the presence of aqueous extracts from Menyanthes trifoliate and Achillea millefolium were co-cultured with allogeneic CD4⁺ T cells and the expression of surface molecules by T cells and their cytokine secretion and cell proliferation determined.

Results

Maturation of DCs in the presence of aqueous extracts from Menyanthes trifoliate or Achillea millefolium did not affect expression of the surface molecules examined but reduced the ratio of secreted IL-12p40/IL-10, compared with that by DCs matured in the absence of extracts. Allogeneic CD4⁺ T cells co-cultured with DCs matured in the presence of aqueous extract from Menyanthes trifoliate secreted less IFN-γ, IL-10 and IL-17 than CD4⁺ T cells co-cultured with DCs matured without an extract. Maturation of DCs in the presence of aqueous extract from Achillea millefolium decreased IL-17 secretion but did not affect IFN-γ and IL-10 secretion by allogeneic CD4⁺ T cells.

Conclusions

Aqueous extract from Menyanthes trifoliate induces a suppressive phenotype of DCs that has reduced capacity to induce Th1 and Th17 stimulation of allogeneic CD4⁺ T cells, whereas aqueous extract from Achillea millefolium reduces the capacity of DCs to induce a Th17 response.     

Armillariella mellea induces maturation of human dendritic cells without induction of cytokine expression

ETHNOPHARMACOLOGICAL RELEVANCE: Armillariella mellea, an edible and medicinal mushroom possessing immuno-modulating potential, has been frequently used for the treatment of infectious diseases or cancers. AIM OF THE STUDY: In order to elucidate immune-regulatory mechanisms of Armillariella mellea, we investigated the effect of water-soluble components from Armillariella mellea (AME) on the regulation of human dendritic cell (DC) maturation and activation. MATERIALS AND METHODS: Immature DCs (iDCs) were prepared by differentiating human peripheral blood CD14-positive cells with GM-CSF and IL-4. Then, iDCs were treated with AME at 2-20mug/ml for 48h and subjected to flow cytometry to analyze the expression of DC markers. Dextran-FITC uptake assay and enzyme-linked immunosorbent assay were performed to examine the endocytic capacity of AME-stimulated DC and their production of cytokines, respectively. RESULTS: iDCs stimulated with AME showed representative features during DC maturation such as up-regulated expression of CD80, CD83, CD86, both MHC class I and II molecules, and CD205, with a simultaneous decrease in the expression of CD206 and the endocytic capacity. Interestingly, AME was not able to induce the production of TNF-alpha, IL-12p40, or IL-10, whereas lipopolysaccharides induced a substantial increase of all of the cytokines. CONCLUSION: Armillariella mellea induces maturation of human DCs through a unique mechanism without inducing cytokine expression.     

细胞因子自体回输联合干扰素、拉米夫定治疗慢性乙型肝炎疗效观察

目的研究细胞因子树突细胞(DC)及细胞因子诱导的杀伤细胞(CIK)自体回输对慢性乙型肝炎患者临床疗效的影响。方法选取慢性乙型肝炎患者480例,随机分成3组,第一组只接受活化DC联合HBsAg特异性CIK细胞自体回输治疗,第二组给予细胞因子自体回输联合干扰素治疗,第三组予细胞因子自体回输治疗联合拉米夫定治疗。分别检测治疗前及治疗结束后的肝功能、HBV DNA定量、HBeAg定量并进行比较。结果治疗后3组血清ALT、AST、TBil水平及HBV DNA定量、HbeAg定量均明显下降(P均<0.01)。结论细胞因子自体回输治疗可有效改善乙肝患者的肝功能及细胞免疫功能,联合干扰素、拉米夫定治疗效果更优。     

Complementary Usage of Rhodiola crenulata (L.) in Chronic Obstructive Pulmonary Disease Patients: The Effects on Cytokines and T Cells

Although chronic obstructive pulmonary disease (COPD) is an inflammatory disease predominantly involving T cells, no study of Rhodiola as an immunomodulator in COPD patients has been reported. In this study, COPD patients took Rhodiola crenulata 500 mg (n = 38) or placebo (starch/phosphate buffered saline) (n = 19) daily for 12 weeks and were compared with untreated, age‐matched, and sex‐matched non‐COPD control subjects. Our results showed that serum levels of IL‐2, IL‐10, and IFN‐γ in COPD patients before treatment are significantly higher than levels in non‐COPD controls (p < 0.05). A significant decrease in IFN‐γ was seen in the Rhodiola treatment group (p < 0.05) but not in the placebo group (p > 0.05). The results suggested that Rhodiola treatment had beneficial antiinflammation effects, lower COPD assessment test score and decreased high‐sensitivity C‐reactive protein, on COPD patients (p < 0.05). The effects of Rhodiola treatment on COPD patients were shown to decrease the IFN‐γ concentration and CD8⁺ count but increase the expressions of CD4⁺CD25⁺FOXP3⁺ and CD4⁺CD25⁺CD45⁺FOXP3⁺ in the blood significantly (p < 0.05). This is the first trial using Rhodiola as a complementary therapy for COPD patients. T cells play an important role in the pathogenesis of COPD through the increased expression of CD8⁺ T cells and IFN‐γ and may be a viable target for potential therapy. Copyright © 2014 John Wiley & Sons, Ltd.     

The differential immunological activities of Ganoderma lucidum on human pre-cancerous uroepithelial cells

Aims of the study

Ganoderma lucidum is active to stimulate immunological effector cells, but the effects on uroepithelial cells have never been explored. The present study compared the expression of major cytokines induced by the water (GLw) and ethanol (GLe) extracts of G. lucidum.

Materials and Methods

The pre-cancerous human uroepithelial cell (HUC-PC) line was employed. A total of 15 cytokines, including major Th1/Th2 cytokines and chemokines, were measured in the complete media after 24 h incubation with GLw and GLe. Additionally, the following assays were performed: cytotoxicity, apoptosis, migration of neutrophils, and nuclear factor-kappaB (NF-κB) DNA binding activity.

Results

GLe inhibited the growth of HUC-PC cells through apoptosis. Interleukins IL-2, IL-6, and IL-8 were significantly up-regulated by GLe in dose-dependent manners, but not by GLw. However, MCP-1 level was significantly increased by GLw but was oppositely reduced by GLe. Furthermore, the elevation of cytokine expression was correlated with the enhancement of p50/p65 NF-κB activity induced by GLe. The elevated IL-8 levels in GLe-treated cells were also correlated with the migration of neutrophils.

Conclusions

GLe and GLw exhibited different immunological activities on the HUC-PC cells. In particular, the activities of GLe may favor the clearance of high risk urothelial cells, suggesting potent chemopreventive ingredients are extractable by ethanol from G. lucidum.     

Early antiallergic inflammatory effects of Rhus verniciflua stokes on human mast cells

Rhus verniciflua Stokes (RVS) is a traditional medicine used in Korea, Japan and China to treat various diseases including catharsis, diaphoretic gastritis and stomach cancer. However, the effects of RVS on allergic inflammatory diseases are unknown to date. This study showed the antiallergic inflammatory effects of RVS on human mast cells (HMC‐1) which were stimulated by phorbol myristate acetate (PMA) and calcium ionophore A23187. RVS inhibited the expressions of TNF‐α, IL‐6 and IL‐8 that were stimulated by treatment with both PMA and A23187. Among the mitogen‐activated protein kinases (MAPKs), extracts of RVS suppressed the phosphorylation of ERK and p38, whereas RVS increased the phosphorylation of JNK in HMC‐1. Consistent with the regulation of MAPKs, it was found that RVS inhibited the nuclear translocation of nuclear factor (NF)‐κB via inhibition of the phosphorylation of IκB‐α, which are important processes in controlling inflammatory responses. Taken together, these results suggest that RVS modulates the expressions of signal molecules related to allergic inflammatory responses mainly through the ERK signaling pathway, suggesting that RVS could be used as a treatment for mast cell‐derived allergic inflammatory diseases. Copyright © 2009 John Wiley & Sons, Ltd.     

Mechanisms of Panax ginseng in preventing rat pheochromocytoma cells from apoptosis

Aims of the study

Although ginseng root possesses dominant central therapeutic effects and has recently undergone investigations for treating different neuronal diseases, most of its mechanisms are still unknown. Therefore, the neuroprotective mechanisms of ginseng were studied.

Materials and methods

The protection afforded by different methanol extracts of Panax ginseng (PG) was tested in a serum deprivation-induced apoptotic model using neuronal-like pheochromocytoma (PC12) cells. An MTT assay, annexin V-FITC staining, and Western blots were, respectively, applied to identify the viability of cells, the apoptotic form of cell death, and the activity of antiapoptotic signaling.

Results

The known antiapoptotic PI3-K/Akt and MEK/ERK pathways in this system were ruled out due to failure of LY 294002 and PD 98059 to block the protection by PG. A protein kinase A (PKA) inhibitor was found to block the protection by PG and PG-induced CREB phosphorylation, suggesting that the PKA/CREB pathway mediates the protective effect of PG. Downregulation of classical and novel PKCs failed to block the protection by PG, while an atypical PKC inhibitor blocked protection by PG.

Conclusions

PKA and atypical PKC are important for the protection afforded by PG in preventing serum deprivation-induced PC12 cell apoptosis.