Immunoregulatory Activities of Human Trophoblasts IVIediated by Polyamine Complexes

ABSTRACT: In a previous publication we described the presence in human placenta (HP) of immunosuppressive factors inhibiting the lymphoproliferative responses to mitogen. The results of further study reported herein indicate that the substance involved is of a syncytiotrophoblastic origin, that it is thermostable to 100°C for 1 hr, and of low molecular weight, i.e. 3,500. It was defined as a polyamine conjugate with nucleic acids. Trophoblast cell extracts lost their immunosuppressive ability after heating in cultures of human lymphocytes supplemented with 5% autologous serum. These effects were, however, preserved both in cultures assayed in 5% fetal calf serum and in those to which purified polyamine oxidase (PAO) was added to autologous serum. Trophoblast cell extract was found to contain polyamine oxidases. Placental PAO can be inhibited by quinacrin a typical inhibitor of flavoprotein enzymes but not by isoniazid, an inhibitor of pyridoxal enzymes; this would suggest that the enzymes in human placenta are of a tissular rather than seric origin. The implication of these observations is that immunosuppression is mediated by oxydative products issued from an interaction between polyamine and polyamine oxidase in the syncytiotrophoblast cytosol. This interaction may constitute the basis for a local immunological barrier and may be involved in the protection of the fetus against maternal immune rejection.     

胃癌病人尿多胺变化的研究

本文应用高效液相色谱法分析34例胃癌病人尿多胺含量,并与19例胃良性溃疡病人及23名正常人对比。结果表明胃癌病人尿多胺含量明显高于胃良性溃疡病人和正常人。有淋巴结转移和肝转移的胃癌病人尿多胺含量明显高于无淋巴结转移和肝转移的胃癌病人。胃癌根治切除术后病人尿多胺含量比术前明显降低。尿多胺含量与胃癌病理分化程度无明显关系。我们认为尿多胺含量测定对胃癌辅助诊断,术前预测肿瘤转移及监测治疗效果有一定的临床意义。     

The antibiotic edeine

Edeine D is pentapeptide amide produced with other edeines by Bacillus brevis Vm₄ strain. This antibiotic is composed of glycine (Gly), isoserine (Ise), 2,3-diaminopropionic acid (A₂pr), 2,6-diamino-7-hydroxyazelaic acid (A₂ha), 3-amino-3-phenyl-propionic acid (Iph), and spermidine (Spe). Partial and full acid hydrolysis, enzymatic degradation with carboxypeptidase B, periodate-permanganate oxidation and examination of Dnp-derivatives suggested the following structure of edeine D: (S)-Iph-(S)-Ise-(S)-A₂ pr-(R,S,R)-A₂ ha-(Gly-Spe).     

Structural control of poly(2-hydroxyethyl methacrylate)-graft-polyamine copolymers for differential retention of rat lymphocyte subpopulations

Poly(2-hydroxyethyl methacrylate)-graft-polyamine copolymers (HA copolymers) of varying composition and chain length of the polyamine graft were prepared by radical copolymerization of 2-hydroxyethyl methacrylate with a given quantity of polyamine macromonomer having a controlled molecular weight, and their interaction with lymphocyte subpopulations (B and T cells) was estimated using a column method. From these results, it was revealed that the most suitable molecular structure of HA copolymers for separating lymphocyte subpopulations is that of an HA copolymer with 13 wt% of polyamine graft with a chain length 3000-6600 in molecular weight. It is concluded that the retention process of lymphocytes on the HA graft copolymers is driven primarily by ionic interactions between the protonated amino groups and the cells. However, the mode of the polyamine microdomain structure, that is the distribution of protonated amino groups, and the conformation of the polyamine chains, which varies with the chain length of the HA copolymer, are also important factors in determining differential lymphocyte retention.     

甘草黄酮提取物对小肠上皮细胞IEC-6迁移及多胺的影响

目的 观察甘草黄酮提取物对小肠隐窝上皮细胞IEC-6迁移及迁移过程细胞内多胺量的影响。方法 划痕法制备细胞迁移模型,观察在多胺合成抑制剂二氟甲基鸟氨酸（DFMO）及钾通道抑制剂4-氨基吡啶（4-AP）存在情况下,甘草黄酮提取物对细胞迁移的影响;柱前衍生-高效液相色谱法检测IEC-6细胞在正常及DFMO存在条件下,给予甘草黄酮提取物12、24 h后细胞内多胺（精脒）的量。结果 甘草黄酮提取物可逆转DFMO或4-AP所致IEC-6细胞迁移抑制;其给药12、24 h后可提高细胞内精脒的量,并逆转DFMO对多胺合成的抑制。结论 甘草黄酮提取物促进细胞迁移的作用与影响细胞内多胺调控信号通路有关。     

Synthesis and application of molecular probe for detection of hydroxyl radicals produced by Na125I and gamma-rays in aqueous solution

Purpose: To synthesize N-(3-(3-aminopropylamino)propyl)-2-oxo-2H-chromene-3-carboxamide (7), a novel DNA-binding, coumarin-based, fluorescent hydroxylradical (^?OH) indicator and to assess its quantum efficiency compared with that of coumarin-3-carboxylic acid (1) and N1,N12-bis[2-oxo-2H-chromene-3-carbonyl]- 1,12-diamine-4,9-diazadodecane (9).

Materials and methods: Using computer-generated molecular modeling, 7 and 9 and their respective 7-hydroxylated derivatives 8 and 10 were docked onto DNA dodecamer d(CGCGAATTCGCG)2, the ligand–DNA complexes were energy minimized, and binding free energies and inhibition constants were calculated. Compound 7 was judged an appropriate target molecule and was synthesized. Compounds 1, 7, and 9 were incubated with Na¹²⁵I or irradiated with ¹³⁷Cs γ-rays, and the influence of pH, dose, type of radiation, and the concentration of indicator on fluorescence yield were determined.

Results: Non-fluorescent 7 and 9 are converted to fluorescent, 7-hydroxylated derivatives 8 and 10 after interaction with ^?OH in aqueous solution. For 1, 7, and 9, hydroxylation yield increases linearly with both Na¹²⁵I dose (0–700×10⁶ decays) and ¹³⁷Cs dose (0–11.0 Gy). Fluorescence induction is significantly reduced at acidic pH and the fluorescent quantum yield of 8 is ～3 times that of 2 or 10 at pH 7.0. With Na¹²⁵I incubation and γ-ray irradiation, the fluorescence signal of 7 increases linearly with concentration and saturates at ～50 μM.

Conclusion: Compound 7 quantifies lower concentrations of ^?OH than do 1 and 9. This detector is therefore likely to be a good reporter of ^?OH produced within a few nanometers of DNA.     

Mouse skin chemical carcinogenesis is inhibited by antizyme in promotion-sensitive and promotion-resistant genetic backgrounds

Elevated polyamine content and increased ornithine decarboxylase (ODC) activity have been associated with neoplastic growth in numerous animal models and human tissues. Antizyme (AZ) is a negative regulator of polyamine metabolism that inhibits ODC activity, stimulates ODC degradation, and suppresses polyamine uptake. Preliminary evidence, obtained from transgenic mice with tissue specific overexpression of AZ indicates that tumor development can be suppressed by AZ. To extend these studies, we have examined the effect of keratin 5 (K5)- or K6-driven AZ transgenes on 7,12-dimethylbenz[a]anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA) chemical carcinogenesis of the skin, in promotion-resistant C57BL/6 and promotion-sensitive DBA/2 mice. On both genetic backgrounds, K6-AZ mice showed a reduction in tumor multiplicity, with 85% fewer tumors than wild-type controls on the C57BL/6 background and 50% fewer tumors on the DBA/2 background. K5-AZ mice developed 50% fewer tumors than controls on both backgrounds. The percent of mice with tumors and tumor size were also reduced in the K5-AZ and K6-AZ groups. Tumor and TPA-treated skin sections from K6-AZ mice exhibited the strongest AZ expression, with localization mainly in suprabasal keratinocytes. K6-AZ mice also had slightly reduced cell proliferation rates in tumors and TPA-treated skin. The lack of a more pronounced effect on cell proliferation is probably explained by the observation that AZ staining did not colocalize with proliferating cell nuclear antigen (PCNA), a marker for the proliferative compartment. These studies demonstrate a tumor-suppressive effect of AZ in C57BL/6 and DBA/2 mice, and confirm the importance of ODC and polyamines in tumor development.     

二氟甲基鸟氨酸对人肺癌细胞L78细胞生长抑制、凋亡诱导及相关基因的表达调控

目的：研究二氟甲基鸟氨酸(DFMO)对人肺癌细胞L78生长及相关基因表达的影响。方法：应用细胞生长曲线、端粒酶活性、细胞形态及DNA电泳观察细胞生长速率及细胞凋亡情况，同时应用Northern blot及免疫组化技术检测相关基因的表达。结果：(1)DFMO处理的L78细胞与对照组相比生长受到抑制，同时，诱导细胞凋亡增多。(2)在DFMO作用下，L78细胞df4基因被诱导表达，同时伴有P21^ras表达下调，Fas基因表达的上调。结论：DFMO抑制L78细胞生长，诱导凋亡的作用与其对df4基因的诱导密切相关，DFMO通过对df4的诱导．调控P21^ras和Fas的表达．     

Hexachlorobenzene-induced early changes in ornithine decarboxylase and protein tyrosine kinase activities, polyamines and c-Myc, c-Fos and c-Jun proto-oncogenes in rat liver.

Hexachlorobenzene (HCB) is a lipophilic chemical compound that is widely distributed in the environment. HCB is known to cause liver tumors in experimental animals. In the present study the in vivo effect of HCB treatment on ornithine decarboxylase (ODC) and protein tyrosine kinase (PTK) activities, free polyamine content, and c-Myc, c-Fos, and c-Jun protein levels in rat liver were investigated. HCB (1000 mg/kg body weight) increased hepatic immunodetectable c-Myc, c-Fos, and c-Jun levels after 6 h, and ODC activity and spermine and putrescine content after 18 and 24 h, while maximum stimulation of PTK activity occurred at 12 h. PTK and ODC activities varied in a dose-dependent manner. The time-course of c-Myc, c-Fos, and c-Jun protein levels was different for each proto-oncogene. They were all elevated at the second day of treatment, while only c-Fos and c-Jun remained elevated after 10 days of HCB exposure. These data jointly suggest that the increase in ODC activity may be the consequence of proto-oncogene induction. The alterations in PTK activity suggest that the growth factor signal transduction pathway may be involved in the regulation of the proto-oncogene levels or/and ODC activity. The decrease in PTK activity after the first day, even in the presence of alpha-D-Difluoromethylornithine (DFMO), an inhibitor of ODC activity, suggests that it is not regulated by polyamines. These results may be relevant to the early molecular events involved in HCB tumor promoter activity in rat liver.     

伯氏疟原虫感染红细胞中的游离氨基酸和多胺生成的研究

伯氏疟原虫氯喹敏感株(CS)和抗氯喹株(CR)感染红细胞中的游离氨基酸量和鸟氨酸脱羧酶活力均相接近,用氯喹10mg/kg im两个株的感染小鼠,20h后对游离氨基酸无抑制作用.氯喹剂量为5mg/kg时,抑制CS和CR感染红细胞的鸟氨酸脱羧酶活力为79.6和55.7％。 CS和CR感染红细胞中的精脒量为139±27和528±140nmol/10~9感染红细胞。环亮氨酸剂量为80mg/kg时,能抑制CS和CR感染红细胞的精脒生成,其抑制率分别为44和57％,加喂甲硫氨酸(100mg/kg)后,精脒量分别上升至294和657nmol/10~9感染红细胞。但是与两者仍有一定差距,故认为在S-腺苷甲硫氨酸合成酶及其后的代谢环节仍有差异.