多胺在动脉粥样硬化发生发展过程中的变化

目的：探讨动脉粥样硬化的发病机制。方法：采用雄性日本鹌鹑喂饲高胆固醇膳食,造成动脉粥样硬化动物模型,动脉观察主动脉壁的中内膜的多胺变化。结果：血浆胆固醇和分类胆固醇提示高脂血症,结合病理切片,说明本实验动脉粥样硬化模型可靠。结论：1．多胺对动脉粥样硬化的发生起着重要作用;2．多胺在动脉粥样硬化发生（病理标准）前升高,后又依次降低的特殊现象。     

黄芪多糖调控多胺介导的Ca~(2+)-RhoA通路促进小肠上皮细胞迁移研究

目的考察黄芪多糖对小肠上皮细胞(IEC-6)迁移及迁移过程细胞内多胺水平、细胞质游离钙离子([Ca2+]cyto)的量、细胞骨架蛋白Rho A表达的影响,探讨黄芪修复胃肠黏膜损伤的疗效机制。方法黄芪药材经水提醇沉、Sevage法去蛋白后得到黄芪粗多糖,运用DEAE纤维素柱分离得到黄芪多糖I、II、III、IV,黄芪多糖I以Sephadex LH-20凝胶柱色谱得到黄芪多糖V。Tips划痕法建立IEC-6细胞损伤迁移模型,柱前衍生高效液相色谱法测定多胺的量,流式细胞仪检测[Ca2+]cyto水平,Western blotting法检测Rho A蛋白表达。考察黄芪多糖对正常IEC-6细胞[未加α-二氟甲基鸟氨酸(DFMO)]和多胺耗竭IEC-6细胞(加入DFMO)迁移、多胺水平、[Ca2+]cyto的量及Rho A蛋白表达的影响。结果黄芪粗多糖、黄芪多糖I、黄芪多糖V(50、100、200 mg/L)均能促进IEC-6细胞迁移(P0.01),并且可逆转多胺合成抑制剂DFMO所致的细胞迁移抑制效果(P0.01);在正常(未加DFMO)或多胺耗竭情况(加DFMO),黄芪多糖V均可提高迁移过程细胞内多胺的量(P0.01);黄芪多糖V可提高细胞迁移过程[Ca2+]cyto水平(P0.01),并且可逆转DFMO所致的[Ca2+]cyto水平下降(P0.01);黄芪多糖V(100、200 mg/L)可明显提高Rho A蛋白表达,同时可逆转DFMO所导致的Rho A蛋白表达抑制作用。结论黄芪多糖可加速胃肠黏膜损伤早期修复过程,其机制可能与增加黏膜上皮细胞多胺的量,提升[Ca2+]cyto,从而提高Rho A蛋白表达,进而促进胃肠黏膜上皮细胞迁移有关。     

多胺对白桦悬浮细胞生长和三萜积累的影响

目的 分析外源多胺对白桦悬浮细胞生长和三萜积累的影响。方法 在白桦悬浮细胞的生长末期添加0.1 mmol/L和1.0 mmol/L的腐胺（Put）、精胺（Spm）和亚精胺（Spd）,采用比色法和RT-PCR方法分析白桦三萜量及其合成关键酶羽扇豆醇合酶（LUS）基因的表达。结果 除1.0 mmol/L Spm处理使白桦悬浮细胞的活力和干质量积累降低外,其他处理均提高了白桦悬浮细胞的活力、干质量积累和三萜产量,且随着处理时间的延长,干质量积累和三萜产量呈增加趋势。其中1.0 mmol/L Put在处理的第2天对细胞干质量和三萜产量的促进效应最大,分别比对照增加了38.89%和116.35%。LUS基因的RT-PCR检测结果进一步证实了多胺对白桦三萜积累的促进作用。结论 Put可有效促进白桦悬浮细胞生长和三萜积累。     

大鼠局灶性脑缺血再灌注后PAO活性和多胺含量变化及意义

目的：检测大鼠局灶性脑缺血再灌注不同时相脑皮质及皮质下多胺氧化酶(PAO)活性和多胺含量,探讨局灶性脑缺血再灌注后PAO活性和多胺含量变化的时相规律及意义。方法：采用改良的Longa线栓法,建立大鼠局灶性脑缺血2h后再灌注2,4,8,24h动物模型,用高香草酸辣根过氧化物酶荧光法测定脑缺血区皮质和皮质下不同时相PAO活性变化,用高效液相色谱法测定脑缺血区皮质和皮质下不同时相多胺的含量。结果：实验组大鼠脑缺血区皮质和皮质下PAO活性在再灌注8h后开始升高(P<0.01),其高峰出现在再灌注24h后(P<0.01);实验组腐胺含量于再灌注4h后即开始逐渐升高(P<0.05),高峰出现在再灌注24h后(P<0.05);再灌注8,24h实验组精脒、精胺含量较对照组明显下降(P<0.05)。结论：脑缺血再灌注后PAO活性明显增高,PAO活性的增高促使腐胺高峰的形成,对脑缺血损伤有促进作用。     

Antitumor conjugates with polyamine vectors and their molecular mechanisms

Importance of the field: A polyamine conjugate is a special polyamine derivative composed of polyamine vectors appended directly or by a linker to a cargo with specific biological functions. In recent years, extensive researches have emphasized the fact that polyamine conjugates acting as promising antitumor candidates are becoming increasingly important in the polyamine field.

Areas covered in this review: Two key subjects are illustrated in this review. First, various drug-polyamine conjugates and relevant structure–activity relationships are discussed with a focus on the molecular recognition of polyamine transport system (PTS). Second, the design of polyamine conjugates is following a rational mechanism-based strategy. Therefore, it is critically important to understand the intrinsic properties of PTS on the cell membrane, enhanced pharmacological effects of polyamine vector on cellular components, and resulting comprehensive signaling networks.

What the reader will gain: A general design strategy of polyamine conjugates as well as recent progress in both fundamental mechanism studies and preclinical therapies are provided for the readers.

Take home message: The multiple functions of polyamine moieties in objective conjugates furnish broad development space for more efficacious antitumor agents.     

抗咯萘啶的伯氏疟原虫感染红细胞多胺量的测定

目的：了解疟原虫的多胺代谢与咯萘啶（ＰＮＤ）抗药性的关系。方法：感染伯氏疟原虫ＡＮＫＡ株（ＰＳ）和由该株培育的中抗ＰＮＤ品系（ＰＲＡ）及高抗ＰＮＤ品系（ＰＲＢ）的昆明株小鼠于腹腔接种（ｉｐ）后ｄ７取血，经薄层层析后用荧光分光光度法测定正常ＲＢＣ、ＰＳ、ＰＲＡ和ＰＲＢ感染ＲＢＣ的丁二胺（ＰＴＣ）、精脒（ＳＰＤ）和精胺（ＳＰＭ）量。另有感染ＰＳ和ＰＲＢ的小鼠于ｉｐ后ｄ６分别１次灌胃（ｉｇ）ＰＮＤ５ｍｇ／ｋｇ和１０ｍｇ／ｋｇ，ｄ７取血，按上述方法测定给药后感染ＲＢＣ的多胺量，并与不给药组比较。结果：ＰＳ感染ＲＢＣ的多胺量均明显高于未感染疟原虫的正常ＲＢＣ，而感染ＰＲＡ和ＰＲＢ的ＲＢＣ多胺量又显著高于ＰＳ感染ＲＢＣ，且多胺量的增高与抗性程度有关。经ＰＮＤ治疗后ＰＳ感染ＲＢＣ的ＳＰＤ和ＳＰＭ较未治疗组显著下降，而ＰＲＢ感染ＲＢＣ则未见明显变化。结论：伯氏疟原虫对ＰＮＤ的抗药性与其多胺代谢有关。     

ATP13A2-mediated endo-lysosomal polyamine export counters mitochondrial oxidative stress

Recessive loss-of-function mutations in ATP13A2 (PARK9) are associated with a spectrum of neurodegenerative disorders, including Parkinson’s disease (PD). We recently revealed that the late endo-lysosomal transporter ATP13A2 pumps polyamines like spermine into the cytosol, whereas ATP13A2 dysfunction causes lysosomal polyamine accumulation and rupture. Here, we investigate how ATP13A2 provides protection against mitochondrial toxins such as rotenone, an environmental PD risk factor. Rotenone promoted mitochondrial-generated superoxide (MitoROS), which was exacerbated by ATP13A2 deficiency in SH-SY5Y cells and patient-derived fibroblasts, disturbing mitochondrial functionality and inducing toxicity and cell death. Moreover, ATP13A2 knockdown induced an ATF4-CHOP-dependent stress response following rotenone exposure. MitoROS and ATF4-CHOP were blocked by MitoTEMPO, a mitochondrial antioxidant, suggesting that the impact of ATP13A2 on MitoROS may relate to the antioxidant properties of spermine. Pharmacological inhibition of intracellular polyamine synthesis with α-difluoromethylornithine (DFMO) also increased MitoROS and ATF4 when ATP13A2 was deficient. The polyamine transport activity of ATP13A2 was required for lowering rotenone/DFMO-induced MitoROS, whereas exogenous spermine quenched rotenone-induced MitoROS via ATP13A2. Interestingly, fluorescently labeled spermine uptake in the mitochondria dropped as a consequence of ATP13A2 transport deficiency. Our cellular observations were recapitulated in vivo, in a Caenorhabditis elegans strain deficient in the ATP13A2 ortholog catp-6. These animals exhibited a basal elevated MitoROS level, mitochondrial dysfunction, and enhanced stress response regulated by atfs-1, the C. elegans ortholog of ATF4, causing hypersensitivity to rotenone, which was reversible with MitoTEMPO. Together, our study reveals a conserved cell protective pathway that counters mitochondrial oxidative stress via ATP13A2-mediated lysosomal spermine export.

Loss-of-function mutations in ATP13A2 (PARK9) are causative for a spectrum of neurodegenerative disorders, including Kufor-Rakeb syndrome (KRS, a juvenile onset parkinsonism with dementia) (1), early-onset Parkinson’s disease (PD) (2, 3), hereditary spastic paraplegia (HSP) (4), neuronal ceroid lipofuscinosis (5), and amyotrophic lateral sclerosis (6), which are commonly hallmarked by lysosomal and mitochondrial dysfunction (4, 6, 7). Also, ATP13A2 deficiency causes lysosomal and mitochondrial impairment in various models, as evidenced by decreased lysosomal functionality (8, 9), reduced mitochondrial clearance capacity (8–10), mitochondrial fragmentation, mitochondrial DNA damage, and increased oxygen consumption (11, 12).We recently discovered that ATP13A2 transports the polyamines spermidine and spermine from the late endo/lysosome to the cytosol (9). Polyamines are ubiquitous polycationic aliphatic amines that stabilize nucleic acids, influence protein folding, regulate ion channels, and modulate cell proliferation and differentiation (13–15). We found that the late endo-lysosomal transporter ATP13A2 strongly contributes to the total cellular polyamine content via a two-step process: Firstly, polyamines enter the cell via endocytosis and subsequently, polyamines are transported by ATP13A2 into the cytosol (9). This process complements polyamine biosynthesis via the ornithine decarboxylase (ODC) pathway (9). Importantly, ATP13A2’s polyamine transport function is crucial for its neuroprotective effect, since it prevents lysosomal polyamine accumulation and subsequent lysosomal rupture, while improving lysosomal health and functionality (9). Moreover, when activated by its two regulatory lipids—phosphatidylinositol-3,5-bisphosphate [PI(3,5)P2] and phosphatidic acid (PA)—ATP13A2 exerts a cell protective effect against the mitochondrial neurotoxin rotenone (16), an environmental risk factor for PD (17). Rotenone is a mitochondrial complex I inhibitor, which leads to high levels of reactive oxygen species (ROS), promoting protein aggregation and damaging organelles. However, how ATP13A2’s polyamine transport function exerts a cell protective effect against rotenone, or other mitochondrial neurotoxins, is not yet clear.Interestingly, the transported substrates spermine and spermidine reduce oxidative stress (14, 15). Spermine is a potent free radical scavenger (18) and a biologically important antioxidant (19–23). We therefore hypothesize that ATP13A2-mediated polyamine transport may counteract oxidative stress (16, 24) and preserve mitochondrial health (11, 12). Here, we demonstrate in complementary human cell models and Caenorhabditis elegans that lysosomal polyamine export by ATP13A2 effectively lowers ROS levels and promotes mitochondrial health and functionality, pointing to a lysosomal-dependent cell protective pathway that may be implicated in ATP13A2-related neurodegenerative disorders.     

多胺对细菌生物膜作用的多样性

生物膜的形成和分散受多种因素调控,阻断生物膜的形成及促进生物膜的解离分散是目前的研究热点和前沿方向。近年来的研究表明,多胺这一在原核和真核生物中广泛存在的物质同样在细菌生物膜的形成和分散过程中起到了非常重要的作用,本文就多胺对细菌生物膜相关作用的研究作一综述。     

自制多聚胺阳离子脂质体转染效率及细胞毒性的评价

目的: 评估制备的多聚胺阳离子脂质体转染哺乳动物细胞的转染效率及细胞毒性. 方法: 多聚胺阳离子脂质TC-Chol与中性磷脂DOPE以3: 1摩尔比,制备多聚胺阳离子脂质体,通过转染以增强型绿色荧光蛋白为报告基因的质粒PIRES2-EGFP入HeLa细胞, Hep2细胞,倒置荧光显微镜下检测转染细胞的报告基因表达,通过MTT法,检测细胞存活分数,并以Lipofectamine2000为对照,评价制备阳离子脂质体转染效率及细胞毒性. 结果: 多聚胺阳离子脂质体转染效率略低于Lipofectamine 2000,但细胞毒性较低,为一种相对高效低毒的阳离子脂质体. 结论: 多聚胺阳离子脂质体为一种相对高效低毒的阳离子脂质体,在基因转染和基因治疗方面具有较广阔的前景.