Isolation and purification of BVⅠ-2H from bee venom and analysis of its biological action

The medical use of bee venom for rheumatoid arthritis (RA) has a very long tradition. In this study, isolation and purification of polypeptides from bee venom were carried out on sephadex chromatography, heparin sepharose CL-6B chromatography and HPLC. Several fractions were extracted, and their effects on activation of splenocyte and THP-1 cell were studied. The inhibitory fraction was selected for further studies. Finally, BVⅠ-2H that the HPLC elution profiles was a single peak was isolated by C8 column. ESI- MS detection results showed that BVⅠ-2H was a fraction of bee venom, and the molecular weight of the major component was 644.8. BVⅠ-2H could inhibit ConA-induced splenocyte proliferation, IL-1 production and interfere with splenocyte cycle in mice. Moreover, BVⅠ-2H could inhibit PMA-induced TNFa production in THP-1 cells, which was due to its inhibitory effects on TNFa mRNA expression and protein phosphorylation of IkBa. Our studies indicated that BVⅠ-2H was one of the anti-inflammatory components of bee venom.     

The involvement of the renin-angiotensin system in the regulation of cell proliferation in the rat endometrium

Oestrogens are known to enhance angiotensin biosynthesis by increasing the elaboration of its precursor, angiotensinogen. On the other hand, we found that inhibition of angiotensin-converting enzyme (ACE) suppressed the proliferative response of the rat anterior pituitary gland to oestrogens. To answer the question whether the angiotensin system is involved in the control of the cell proliferation of the uterine epithelium, the effects of an ACE inhibitor, enalapril maleate, and of angiotensins II and IV, alone or together with losartan, an antagonist of angiotensin receptor type 1 (AT1), on endometrial epithelial cell proliferation have been studied. The experiments were performed on ovariectomized female Wistar rats. In the first experiment the animals were injected with a single dose of oestradiol benzoate or received an injection of solvent only. Half of the oestrogen-treated rats were injected additionally with enalapril maleate (EN, twice daily). The incorporation of bromodeoxyuridine (BrDU) into endometrial cell nuclei was used as an index of cell proliferation. It was found that oestradiol alone dramatically increased the BrDU labelling index (LI) of endometrial cell nuclei, and this effect was partially blocked by the simultaneous treatment with EN. In the second experiment, the animals were injected intraperitoneally with angiotensin II (AII), angiotensin IV (AIV) or saline, alone or together with losartan. It was found that AIV induced an increase in the LI in uterine epithelium, and this effect was not blocked by the simultaneous treatment with losartan. The increase in LI in uterine epithelium was also observed in the rats treated with AII and with losartan. These findings suggest an involvement of angiotensin IV in the control of uterine epithelium cell proliferation. Received 12 October 1998; received after revision 6 January 1999; accepted 2 February 1999     

The complexity of parathyroid hormone-related proteinsignalling

Our understanding of the mode of action of parathyroid hormone-related protein (PTHrP) has changed profoundly during the last decade. Most PTHrP activities are mediated by membrane receptors through autocrine/paracrine pathways. However, both endogenous and exogenous PTHrP also appear to have intracrine effects through translocation into the nucleus. The present review proposes unconventional PTHrP signalling, based on novel clues. First, PTHrP binding to its membrane receptor triggers internalization of the whole complex, mediated by beta-arrestin. There is growing evidence that the receptor and arrestin are the effectors of biological responses, rather than the ligand (or in addition to the ligand). Second, the existence of putative PTHrP targets within the cytoplasm is beginning to be supported. Recent findings of interactions between a COOH-terminus of PTHrP and beta-arrestin and between the PTHrP receptor and 14-3-3 proteins represent the starting point for identification of intracellular partners of both the hormone and its receptor.Received 19 June 2003; received after revision 10 July 2003; accepted 21 July 2003     

Angiogenesis and signal transduction in endothelial cells

Endothelial cells receive multiple information from their environment that eventually leads them to progress along all the stages of the process of formation of new vessels. Angiogenic signals promote endothelial cell proliferation, increased resistance to apoptosis, changes in proteolytic balance, cytoskeletal reorganization, migration and, finally, differentiation and formation of a new vascular lumen. We aim to review herein the main signaling cascades that become activated in angiogenic endothelial cells as well as the opportunities of modulating angiogenesis through pharmacological interference with these signaling mechanisms. We will deal mainly with the mitogen-activated protein kinases pathway, which is very important in the transduction of proliferation signals; the phosphatidylinositol-3-kinase/protein kinase B signaling system, particularly essential for the survival of the angiogenic endothelium; the small GTPases involved in cytoskeletal reorganization and migration; and the kinases associated to focal adhesions which contribute to integrate the pathways from the two main sources of angiogenic signals, i.e. growth factors and the extracellular matrix.Received 13 February 2004; received after revision 25 March 2004; accepted 19 April 2004     

Recombinant expression of perchloric acid-soluble protein reduces cell proliferation

Perchloric acid-soluble protein (PSP) may play an important role in the regulation of cellular physiological functions because it has been highly conserved throughout evolution; however, this role has not been well elucidated. In previous reports, we suggested that PSP regulates cell proliferation. In this study, we examined the effect of PSP expression on proliferation of the normal rat kidney cell line NRK-52E, the rat hepatocyte cell line RLN-10, and the rat hepatoma cell line dRLh-84. Cells transfected with pcDNA-sense-PSP (pcDNA-S-PSP) over-expressed PSP mRNA and protein, and cell proliferation of the transfected cells was suppressed compared with that of cells transfected with pcDNA-empty (pcDNA-E). Cell viability of pcDNA-S-PSP-transfected cells was similar to that of pcDNA-E-transfected cells. Thus, over-expression of PSP suppresses cell proliferation without any influence on cell viability. These findings are the first to report an inhibitory activity of PSP on cell proliferation. Received 27 April 2001; received after revision 8 June 2001; accepted 8 June 2001     

姜黄素对鼻咽癌细胞株CNE-2Z-H5裸鼠移植瘤增殖的影响

目的研究姜黄素对人低分化鼻咽癌细胞系亚克隆株CNE-2Z-H5裸鼠移植瘤生长和增殖的影响。方法复制人低分化鼻咽癌细胞系亚克隆株CNE-2Z-H5裸鼠移植瘤模型,观察姜黄素对移植瘤生长的影响。结果裸鼠体内实验显示姜黄素可以抑制移植瘤的生长。不同浓度姜黄素组移植瘤瘤重与溶剂对照组比较有降低趋势,高剂量组降低更明显,差异有极显著性(P<0.001),抑瘤率达59.75%。结论姜黄素可以抑制CNE-2Z-H5细胞裸鼠移植瘤的生长,其可能在鼻咽癌的治疗中具有一定的价值,值得进一步深入研究。     

姜黄素对鼻咽癌细胞株CNE-2Z—H5裸鼠移植瘤增殖的影响

目的：研究姜黄素对人低分化鼻咽癌细胞系亚克隆株CNE-2Z—HS裸鼠移植瘤生长和增殖的影响。方法：复制人低分化鼻咽癌细胞系亚克隆株CNE-2Z-H5裸鼠移植瘤模型，观察姜黄素对移植瘤生长的影响。结果裸鼠体内实验显示姜黄素可以抑制移植瘤的生长。不同浓度姜黄素组移植瘤瘤重与溶剂对照组比较有降低趋势，高剂量组降低更明显，差异有极显著性（P〈O．001），抑瘤率达59．75％。结论姜黄素可以抑制CNE-2Z—H5细胞裸鼠移植瘤的生长，其可能在鼻咽癌的治疗中具有一定的价值，值得进一步深入研究。     

壳寡糖对Hela细胞的增殖抑制与诱导凋亡

为了明确壳寡糖(COS)对Hela细胞的增殖抑制作用及对凋亡的影响,采用3-(4,5-二甲基噻唑-2)-2,5-二苯基四氮唑溴盐(MTT)法检测增殖抑制作用,Wrights-Giemsa及吖啶橙-溴乙锭(AO-EB)染色观察凋亡细胞的形态,Annexin V-FITC/PI法检测凋亡率,免疫组化法分析Bax,Bcl-2和Survivin表达量变化.结果显示:不同浓度COS处理Hela细胞均能抑制增殖,5.0mg/mL并作用24h对其增殖抑制率为52.15%(P0.01).Wrights-Giemsa染色显示细胞形态趋近圆形,贴壁能力减弱,出现凋亡小体.AO-EB染色时细胞出现早期和晚期凋亡现象.AnnexinV-FITC/PI检测细胞凋亡率为31.75%(P0.05).免疫组化分析细胞内Bax表达量增加,Bcl-2和Survivin表达量降低.表明COS能够抑制Hela细胞增殖并诱导凋亡,其原因与Bax的上调和Bcl-2与Survivin的下调相关.     

虾青素的抗肿瘤作用及其机制

通过论述虾青素的抗肿瘤作用及机制研究,旨在为临床肿瘤治疗相关研究及未来应用提供参考。     

化橘红中主要活性成分对豚鼠气管平滑肌细胞增殖的影响

目的：初步观察化橘红中主要活性成分对豚鼠气管平滑肌细胞增殖的影响。方法通过原代培养豚鼠气管平滑肌细胞,采用 MTT 法观察化橘红中主要活性成分柚皮苷（Naringin）、橘皮内酯（Meranzin）和水合橘皮内酯（Meranzin hydrate）对细胞增殖的影响。结果柚皮苷（0.2~2.0 mg/mL）对豚鼠气管平滑肌细胞增殖有明显的促进作用（P<0.01）,水合橘皮内酯（0.1~1.0 mg/mL）对豚鼠气管平滑肌细胞增殖有明显的抑制作用（P<0.01）,橘皮内酯（0.05~0.5 mg/mL）对豚鼠气管平滑肌细胞的增殖作用不明显（P ＞0.05）。结论柚皮苷与水合橘皮内酯可能是化橘红主要药效活性成分。