视黄酸对小儿淋巴结B细胞发育的作用及其途径

目的探讨视黄酸(RA)对儿童淋巴结B细胞成熟分化的影响,及其与视黄酸受体基因表达水平变化的关系。方法本组24例,按年龄分为<1岁组、1～3岁组和～5岁组,每组8例。取患儿正常淋巴结分离细胞进行体外培养,分为RA组,RA+视黄酸受体α(RARα)拮抗剂(Ro415253)组(RA+Ro),脂多糖组(LPS),(LPS+RA)组和对照组。分别加入atRA、Ro415253、LPS。培养24、48h收集细胞。采用流式细胞术分析细胞表面标志,观察B细胞的成熟分化;RT荧光定量PCR测定视黄酸受体基因mRNA。结果<1岁组,RA组成熟B细胞的百分比明显高于对照组(24h:23%±5%vs17%±3%;48h:28%±6%vs22%±4%)(P均<0.05);LPS+RA组活化B细胞数明显高于LPS组(24h:82%±10%vs76%±8%;48h:83%±8%vs78%±10%)(P均<0.05)。同时,RARα基因表达水平也显著上调,而该受体拮抗剂可抑制RA的调节作用。1～3岁组淋巴结B细胞的成熟和活化呈现完全相同的调节变化,而～5岁组RA的这些调节作用不明显。结论RA能促进体外培养的淋巴结B细胞的分化发育和活化,该作用在3岁以下小儿明显。RARα基因的表达调节可能是介导RA作用的主要途径。     

视黄酸受体在脐血淋巴细胞细胞因子表达中的调节作用

目的研究视黄酸(RA)促进脐血淋巴细胞(CBL)细胞因子表达的作用途径,探讨视黄酸受体α在该过程中的可能作用. 方法收集19例健康新生儿的脐血标本进行体外培养,采用RT-PCR法检测CBL 中视黄酸受体α(RAR-α)、IL-2、IFN-γ和IL-4的mRNA水平.结果 RA上调CBL中RAR-α的基因表达水平, 培养24小时时的上调幅度为(1.17±0.07)倍(P＜0.001).RA上调IL-2的基因表达水平,培养24小时时的上调幅度为(1.29±0.20)倍(P＜0.001).RA也上调IFN-γ的基因表达水平,培养48小时时的上调幅度为(1.39±0.26)倍(P＜0.001).RA还上调IL-4的基因表达水平,培养24小时时的上调幅度为(1.52±0.44)倍(P＜0.002).RA 使RAR-α基因表达的上调幅度与RA使IL-2、IFN-γ和IL-4基因表达的上调幅度皆存在正相关,r值分别为0.40、0.39和0.46, (P<0.05).结论 RAR-α可能参与RA对CBL细胞因子(IL-2、IFN-γ和IL-4)表达的促进作用.RA可能通过增加RAR-α的表达而上调IL-2、IFN-γ及IL-4等细胞因子的表达,从而促进CBL的功能.     

视黄酸受体α通过调控视皮质轴突蛋白1参与维生素A缺乏大鼠孤独症样行为的机制研究北大核心CSCD

目的探讨视黄酸受体α(retinoic acid receptorα,RARα)信号变化通过调控视皮质轴突蛋白1(neurexin 1,NRXN1)参与维生素A缺乏(vitamin A deficiency,VAD)大鼠孤独症样行为的机制。方法构建孕期开始的维生素A正常(vitamin A normal,VAN)和VAD母鼠模型,并在生后早期对部分VAD母鼠和仔鼠给予维生素A补充(vitamin A supplement,VAS)。各组仔鼠(n=20)于6周龄进行行为学检测,利用三箱和旷场实验检测各组仔鼠社交行为和重复刻板行为;采用高效液相色谱法检测各组仔鼠血清视黄醇水平;采用电生理实验检测各组仔鼠视皮质的长时程增强(long-term potentiation,LTP)水平;采用实时荧光定量PCR法和Western blot法检测RARα、NRXN1和N-甲基-D-天冬氨酸受体1(N-methyl-D-aspartate receptor subunit 1,NMDAR1)的表达水平;采用染色质免疫共沉淀技术检测RARα转录因子在NRXN1基因启动子区的富集量。结果VAD组仔鼠出现社会交往障碍、重复刻板等孤独症样行为表现,生后开始的VAS可改善仔鼠大部分行为缺陷。VAD组仔鼠血清视黄醇水平明显低于VAN组和VAS组(P<0.05)。VAD组仔鼠视皮质NMDAR1、RARα和NRXN1的mRNA和蛋白表达水平及LTP水平均较VAN组和VAS组显著降低(P<0.05)。VAD组仔鼠视皮质中RARα转录因子在NRXN1基因启动子区的富集量较VAN组和VAS组显著下降(P<0.05)。结论RARα通过调控NRXN1影响VAD大鼠视皮质突触可塑性,从而参与VAD大鼠孤独症样行为的形成。[中国当代儿科杂志,2022,24(8):928-935]     

RARα调控稳态突触可塑性在孤独症谱系障碍发病机制中的研究进展

孤独症谱系障碍是儿童神经精神发育性疾病领域亟需解决的重要疾病, 发病率逐年增高, 给家庭和社会带来了沉重负担。不同单基因突变模型的功能研究表明稳态突触可塑性受损是导致这些重叠表型的共同机制。视黄酸受体α(retinoic acid receptor α, RARα)通过谷氨酸受体亚基1翻译控制和RARα/ mTOR信号传导途径双向调控神经系统稳态突触可塑性, 影响感觉信息整合和情境适应能力, 同时通过树突棘生长影响学习记忆功能和神经突触信号网络。这些研究进展提示RARα可能作为调节稳态突触可塑性和改善孤独症谱系障碍症状的潜在药物靶点, 有助于临床上对孤独症谱系障碍进行临床分子分型和精准诊治工作。     

维生素A对脐血树突状细胞分化与成熟及其功能的影响

目的　研究维生素A在体内的代谢活性产物视黄酸 (retinoicacid ,RA)对树突状细胞(dendriticcells ,DC)分化、成熟及功能的影响 ,进一步探索维生素A对免疫功能调节的机理。方法　取健康足月儿脐血 9份分离单个核细胞后 ,进行体外培养诱导DC的同时加入生理浓度的RA ,采用流式细胞仪检测DC的表面分子CD1a、CD83、HLR DR以判断RA对DC分化、成熟的影响 ;混合淋巴反应的强度观测RA对DC抗原递呈功能的作用 ;荧光定量PCR法检测细胞因子IL 12p35、IL 12p4 0、IFN γ(Th1)、IL 4、IL 10 (Th2 )mRNA转录水平 ,分析RA对DC诱导Th细胞分化的影响。结果　培养第 6天RA使DC数量显著下降 (P <0 0 0 1) ,培养第 9天 ,DC总数相仿 ,但RA处理后不成熟DC百分比增高 ,而成熟DC百分比降低 ,差异有显著意义 (P <0 0 0 1) ;DC混合淋巴反应的cpm值降低2 9 4 % (P <0 0 0 1)。细胞因子IL 12、IFN γmRNA下降 ,而IL 4、IL 10的mRNA水平升高 ,差异均具有显著意义。结论　维生素A延迟体外培养的脐血单个核细胞向DC的分化和成熟 ,且降低其混合淋巴细胞反应的能力 ,减少Th1细胞因子的产生而增加Th2细胞因子的产生 ,使免疫反应向Th2方向偏移。     

bFGF与RA对中枢神经系统细胞增殖分化的调节

碱性成纤维细胞生长因子是促进神经干细胞增殖的重要细胞因子，通过与靶细胞表面特异性酪氨酸激酶跨膜受体结合，促进神经干细胞增殖，推迟其分化，维持干细胞及其后裔细胞的存活，碱性成纤维细胞生长因子的撤退可触发神经干细胞分化。视黄酸(RA)是一种调节神经系统发育的重要营养素，通过核受体或直接通过RA反应元件调节细胞的基因表达。RA可加强干细胞向神经元、星形胶质细胞方向分化，而抑制其向少突胶质细胞方向分化。     

外源性视黄酸调节乳鼠心肌细胞Tbx1的表达

目的 研究视黄酸(RA)对心肌细胞Tbx1基因表达的影响.方法 分离培养乳鼠心肌细胞,经不同浓度的RA处理后,采用RT-PCR和Western blot方法分别检测乳鼠心肌细胞Tbx1基因在mRNA和蛋白水平表达的变化.结果 Tbx1基因在乳鼠心肌细胞有少量基础的表达,在予以RA刺激后,1×10-7mol/L RA使细胞内Tbx1基冈mRNA和蛋白含量表达分别增加1.51倍和1.10倍(P均<0.05),1×10-6 mol/L RA使细胞内Tbx1基因mRNA和蛋白含量表达分别增加2.21倍和2.38倍(P均<0.05).结论 RA可以上调乳鼠心肌细胞Tbx1的表达,且此作用呈剂量依赖效应.     

视黄酸对乙醇致斑马鱼胚胎心脏发育畸形的影响

目的探讨在斑马鱼胚胎发育中外源性视黄酸(RA)是否能逆转乙醇的毒性。方法采用原位杂交方法检测乙醇和RA共同处理、二者单独处理斑马鱼胚胎后nkx2.5基因的表达及DEAB(视黄醛脱氢酶的抑制剂)与乙醇共同处理及单独处理后nkx2.5基因的表达。采用RT-PCR的方法检测gata5、gata6、raldh2基因的表达,并检测raldh2基因敲除后gata5、gata6的表达变化。结果将RA和乙醇共同处理斑马鱼胚胎后,胚胎发育畸形更加明显,在受精后24 h(24 hpf)nkx2.5的原位杂交结果显示双侧心脏原基不能融合成单个原始心管;乙醇单独处理胚胎影响心脏的环化过程,且nkx2.5的表达上调;乙醇与RA共同处理后,gata5、gata6及raldh2的表达较正常对照组轻微上调,但差异无统计学意义,而敲除raldh2基因后,gata5、gata6的表达有显著下调;DEAB处理胚胎后,原始心管融合正常;300 mmol.L-1乙醇处理后,心脏原基不能融合成原始心管,与200 mmol.L-1乙醇及RA共同处理的表型相似。结论RA和乙醇共同处理后,通过影响原始心管融合而加重心脏发育的畸形,这种现象可能是因为乙醇代谢率...     

胰岛素样生长因子Ⅰ类受体反义核酸对脐血B淋巴细胞功能的调节

目的：探讨胰岛素样生长因子Ⅰ类受体（IGF－ⅠR）与脐血B淋巴细胞增殖以及IgM合成的关系。方法：通过反义核酸阻抑脐血B淋巴细胞IGF－ⅠR基因表达水平,采用同位素掺入法观察B淋巴细胞的增殖功能,利用酶联免疫吸附（ELISA）双抗夹心法检测IgM含量,通过逆转录聚合酶 链反应技术检测IGF－ⅠR基因表达。结果：经反义寡核苷酸（ASON）阻抑后,脐血B淋巴细胞IGF－ⅠRmRNA的表达水平明显降低,降低幅度波动于15％－49％;同时B淋巴细胞的增殖功能较单纯美洲商陆（PWM）刺激下降54％,细胞活化第5天IgM的生成量明显降低。结论：IGF－ⅠR参与脐血B淋巴细胞增殖、分化以及IgM的产生过程,提示IGF－ⅠR与IGF－Ⅰ结合发挥的生物活性在维持新生儿时期体液免疫水平方面起着重要的促进作用。     

Shh和Fgf8介导的视黄酸对22q11.2微缺失综合征心肌细胞TBX1表达的影响

目的探讨Shh和Fgf8介导的视黄酸(RA)对22q11.2微缺失综合征中心肌细胞TBX1基因的调节机制。方法出生1～2 d SD乳鼠26只,分离培养乳鼠心肌细胞,48 h后用流式分选方法分选纯化心肌细胞,纯化的心肌细胞继续培养48 h。分为空白对照组;阴性对照组;处理1组:1×10-7mol/L RA;处理2组:3×10-7mol/L RA;处理3组:5×10-7mol/L RA。采用RT-PCR和Western blot方法分别检测乳鼠心肌细胞Shh、Fgf8 mRNA和蛋白相对量表达的变化。结果Shh和Fgf8在乳鼠心肌细胞有少量的表达,给予RA刺激后,与空白对照组比较,3×10-7mol/L RA使细胞内Shh mRNA和蛋白水平分别增加1.51倍和1.10倍(t=11.328,15.598 Pa<0.05),5×10-7mol/LRA使细胞内Shh mRNA和蛋白水平分别增加2.21倍和2.38倍(t=13.761,18.982Pa<0.05);3×10-7mol/L RA使细胞内Fgf8 mRNA和蛋白水平分别增加2.50倍和0.80倍(t=14.368,24.226 Pa<0.05),而5×10-7mol/LRA使细胞内Fgf8 mRNA和蛋白水平分别增加3.48倍和2.04倍(t=23.926,26.364 Pa<0.05)。结论RA可以上调乳鼠心肌细胞Shh和Fgf8的表达,且呈剂量依赖效应。Shh和Fgf8参与了RA对心肌细胞TBX1的调节过程。     

Successful treatment of retinoic acid syndrome with high-dose dexamethasone pulse therapy in a child with acute promyelocytic leukemia treated with ATRA

A 5 year old female developed femoral pain, fever, and hemorrhagic tendency. She was diagnosed as having acute promyelocytic leukemia (APL). Approximately 2 weeks after the administration of all-trans retinoic acid (ATRA), she developed a high fever, edema, and respiratory distress which met the criteria for retinoic acid syndrome. At first, we tried to treat the patient with oral corticosteroid, however, this approach was unsuccessful. Considering the worsening of her condition, we then chose to administer a large dose of intravenous dexamethasone therapy for 3 days. Immediately after this therapy, she became afebrile, respiratory distress and edema disappeared, and there was a general improvement of the symptoms. All-trans retinoic acid at the reduced dose of 25 mg/m², was continued for an additional 6 weeks and then discontinued. Since the cessation of dexamethasone and ATRA, there has been no relapse of APL in this patient. Although based on only one case, we recommend the intravenous high-dose dexamethasone pulse therapy (13 mg/m² per day, for 3 days) for treating retinoic acid syndrome which develops in pediatric APL patients treated with ATRA.     

Retinoids and Retinoid Receptors in Teratogenesis*

There is overwhelming evidence that vitamin A (retinol), presumably through its metabolite retinoic acid, participates in organogenesis at several stages and sites during normal development. Besides the important role of retinol and retinoic acid (RA) as micronutrients in growth and development, these retinoids and their synthetic analogs are now viewed as drugs for treatment of oncologic and dermatologic diseases. An excess of vitamin A, RA, or several other synthetic analogs are teratogenic. Mechanisms involved in teratogenesis remain unsolved but are under active investigation in many laboratories. The attention has recently focused on a series of endogenous proteins which serve as nuclear receptors for natural retinoids as means to discover how retinoids intervene in diverse cellular functions and which of their cellular and molecular targets are crucial to the developing embryo. There are two classes of receptors, termed retinoic acid receptors (RARs) and retinoid X receptors (RXRs). This brief review summarizes the results of our recent studies which suggest that: 1) the teratologic effects of retinoids are mediated by the nuclear receptors; 2) the heterodimer RXR/RAR pathway is the major mechanism for the induction of teratogenesis; 3) RXR-selective synthetic retinoids have diminished teratogenicity; and 4) an overexpression of specific RARs in response to RA disrupt skeletal morphogenesis resulting in limb reduction defects.     

全反式维甲酸对足细胞损伤保护作用的研究进展

全反式维甲酸(ATRA)是维生素A类衍生物,在调节细胞聚集、分化、凋亡、增殖及炎症反应中起重要作用。近年来ATRA在肾脏疾病的作用,特别是对足细胞保护作用的研究取得了一定进展。该文就足细胞损伤、ATRA作用特点,以及ATRA诱导足细胞分化及再生、抗增殖与纤维沉积、抑制凋亡等保护作用研究进展作综述。     

Masked Deficit of Vitamin B12in a Turkish Girl with Thalassemia

A 12-year-old girl with acute promyelocytic leukemia has been treated with conventional chemotherapy. The patient remained in complete remission for a year when the first bone marrow relapse occurred. Since reinduction chemotherapy was rejected by the parents, an alternative treatment with oral all-trans retinoic acid was administered. A second complete remission was achieved within 100 days. After 14 months a second bone marrow relapse occurred. AM-trans retinoic acid and the combination with interferon-a failed.     

All-Trans Retinoic Acid as an Alternative to Chemotherapy in the Treatment of Acute Promyelocyte Leukemia

A 12-year-old girl with acute promyelocytic leukemia has been treated with conventional chemotherapy. The patient remained in complete remission for a year when the first bone marrow relapse occurred. Since reinduction chemotherapy was rejected by the parents, an alternative treatment with oral all-trans retinoic acid was administered. A second complete remission was achieved within 100 days. After 14 months a second bone marrow relapse occurred. AM-trans retinoic acid and the combination with interferon-a failed.     

地塞米松、维甲酸对大鼠肺发育的影响及与胰岛素样生长因子关系

目的探索地塞米松(Dex)、维甲酸(RA)对大鼠肺发育的影响及其与胰岛素样生长因子(IGF)_Ⅰ、(IGF)_Ⅱ的关系。方法将80只SD孕鼠分为4组,即对照组(A组)、Dex1组(B组)、Dex2组(C组)、RA组(D组)。A、B、D组于孕18～20d分别皮下注射生理盐水、Dex,腹腔注射RA,C组于生后1～3d皮下注射Dex。各组于孕18、20、21d(C组孕期不取)、生后1、3、5、7、10、14、21d取肺标本作病理学检查、辐射状肺泡计数(RAC)、IGF_Ⅰ、IGF_Ⅱ多肽或mRNA之肺表达强度。结果①形态学及肺表达:B、C组早期肺泡发育提前(数目多,壁薄),晚期则腔大数少;IGF_Ⅰ主要表达于肺胞分隔期(生后4～10d),A、D组等肺泡发育时,IGF_Ⅰ呈强阳性表达,其他各组或时间点则呈弱阳性或阴性表达;IGF_Ⅱ的表达主要见于出生前支气管,小血管等管道组织,受Dex等影响较小。②Westernblot结果:IGF_Ⅰ多肽的表达:A组生后5～7d达高峰,随后渐降低;B组孕20d～生后3d,各时间点强度明显高于A组(P<0.01),以后均低于A组(P<0.01);C组晚期强度明显低于A组(P<0.01);D组各时间点浓度明显高于A组(P<0.01)。IGF_Ⅱ多肽的表达:各组孕18d最高,随后渐降低直至微量。③RT_PCR结果:IGF_Ⅰ、IGF_ⅡmRNA表达的强度变化与各自的肽浓度变化相似。结论IGF_Ⅰ、IGF_Ⅱ与肺发育过程有密切关系,IGF_     

全反式维A酸对缺氧性肾小管上皮细胞Prohibitin1和Prohibitin2表达的影响

目的 探讨全反式维A酸(ATRA)对缺氧性肾小管上皮细胞(RTEC) Prohibitin1(PHB1)和Prohibitin2(PHB2)表达的影响.方法 购自上海生物细胞库的大鼠近端肾小管上皮细胞株NRK-52E,采用混有胎牛血清和双抗的培养基(100 mL培养基中加5 mL胎牛血清和1 mL双抗)在37℃、50 mL/L二氧化碳的培养箱中培养.传代3次后分为正常组、模型组和ATRA干预组.正常组细胞不做任何处理,模型组细胞置于真空罐中,负压吸引器吸尽残余空气,充人缺氧气体(950 mL/L氮气和50 mL/L二氧化碳)密封建立缺氧性RTEC损伤模型,ATRA干预组细胞中加入0.1 μmol/L ATRA后参照模型组的方法进行缺氧.于缺氧24 h、36 h采用实时荧光定量PCR法测定各组NRK-52E细胞PHB1、PHB2、转化生长因子-β1(TGF-β1)的mRNA表达,Western blot法检测各组NRK-52E细胞PHB1、PHB2、TGF-β1的蛋白表达.结果 1.与正常组比较,模型组和ATRA干预组2个时间点NRK-52E细胞的PHB1和PHB2的蛋白表达量及其mRNA表达量均显著下降(P均＜0.05),缺氧时间越长,表达量越低；与模型组比较,ATRA干预组2个时间点NRK-52E细胞的PHB1和PHB2的蛋白表达量及其mRNA表达量均显著上升(P均＜0.05).2.与正常组比较,模型组和ATRA干预组2个时间点NRK-52E细胞的TGF-β1的蛋白表达量及其mRNA表达量均显著上升(P均＜0.05),缺氧时间越长,表达量越高；与模型组比较,ATRA干预组2个时间点NRK-52E细胞的TGF-β1的蛋白表达量及其mRNA表达量均显著下降(P均＜0.05).结论 ATRA可显著增强缺氧性RTEC中PHB1和PHB2蛋白表达量及其mRNA表达量,可能对缺氧性RTEC有保护作用.     

Conducting Developmental Toxicity Studies Using the Ferret: Retinoic Acid as a Positive Control

The search for a carnivore as an addition to a multilevel test system for determining developmental toxicity has been extended to include the ferret. The following discussion is an effort to simplify the procedures which should be used with this species when conducting a typical Segment II - Teratology Study and to reduce the uncertainties which always accompany the introduction of a different animal model. It is recommended that developmental toxicity studies in ferrets include a positive control group. All- trans retinoic acid (15 mg/kg on day 14 of gestation) had minimal effects on the dam and her pregnancy and maximal effects on the fetus. Administration of retinoic acid did not alter maternal weight or weight gain nor affect the average numbers of corpora lutea, implantations, resorptions or litter sizes. It did, however, reduce fetal body weight, produce gross external alterations in 90.6% of the fetuses and increase the skeletal alterations (particularly of the skull) in the exposed fetuses as compared with controls. Timed pregnant ferrets may be received from a supplier within a day or two after mating without interfering with implantation which occurs on day 12. Intubation with the test article is conducted throughout organogenesis from day 12 to day 30 with sacrifice on day 35 of gestation. Examination of the ferret fetuses is similar to that conducted with rat fetuses.     

急性白血病对维A酸耐药及其逆转研究进展

目前维A酸(RA)及其衍生物被广泛应用于急性早幼粒细胞白血病的治疗,并已开始尝试于其他类型急性髓系白血病的治疗.但白血病治疗出现了不少RA耐药现象,明确其耐药机制并探讨逆转策略有助于改善临床疗效和应用前景.现就近年来全反式RA耐药机制及其逆转方面取得的进展作一综述.