水母毒素研究与转化医学

水母蜇伤是最常见的海洋生物伤,其发生率随着近年来环境变化引起的水母爆发性增长在不断上升。水母毒素具有心血管、溶血、神经、肌肉等多种生物毒性,其作用机制不明确,水母蜇伤防治也以对症处理为主。注重水母蜇伤临床症状、救治措施与水母毒素纯化鉴定、作用机制之间的相互联系,将加速水母毒素研究的整体推进。     

水母毒素与水母蜇伤

水母蜇伤是最常见的海洋生物伤,其发生率随着人们与海洋环境的密切接触不断上升。水母形态结构虽然简单,但其毒素组成复杂,可造成机体多个系统不同程度的损伤,因此水母蜇伤后临床症状较为复杂,目前尚没有基于毒素作用机制的特效抗毒药物。本文从水母毒素、水母蜇伤症状以及蜇伤后综合治疗三个方面进行综述,着重阐述近年来水母毒素组分研究的新进展以及针对毒素组分的拮抗药物的研究动态。     

水母毒素心血管活性研究进展

简要介绍水母毒素的心血管毒性及其作用机制,重点讨论了Ca2+通道、儿荼酚胺受体、胆碱能受体等与水母毒素心血管效应的关系.     

蛋白酶抑制剂对霞水母毒素溶血活性的影响

目的研究蛋白酶抑制剂对霞水母毒素溶血活性的影响。方法首先制备霞水母刺丝囊细胞,再利用Mini-Beadbeater组织研磨器破碎细胞提取毒素,然后向获得的霞水母毒素中加入不同种类及剂量的蛋白酶抑制剂,如金属酶抑制剂EDTA、酸性蛋白酶抑制剂Pepstantin A、丝氨酸蛋白酶抑制剂PMSF和Aprotinin,巯基蛋白酶抑制剂Leupeptin,并且测定蛋白酶抑制剂对霞水母毒素溶血活性的影响。结果 EDTA和Pepstantin A能够明显抑制蛋白酶的活性从而增强霞水母毒素的溶血活性,1 mmol.L-1EDTA和4μg.ml-1 Pepstantin A使其溶血率分别从40%上升到93%和5%上升到78%;而PMSF、Aprotinin和Leupeptin却对霞水母毒素溶血活性的影响较小。结论金属蛋白酶抑制剂EDTA和酸性蛋白酶抑制剂Pepstantin A能有效地保护霞水母毒素的溶血活性,为深入研究霞水母毒素提供帮助。     

水母毒素及水母来源新功能蛋白研究进展

水母是海洋中一类数量庞大的浮游生物,其体内含有多种高效的生物活性成分,是一个潜在的海洋药物资源宝库。本文通过概述近年来水母毒素及水母来源新功能蛋白的研究进展,对水母生物活性物质的毒性、抗氧化、抗肿瘤和酶活性等作用特点及机理进行了归纳,为开发新型海洋药物提供科学线索。     

水母皮炎的研究进展

水母皮炎系由水母蜇伤所致,又名海蜇皮炎,每年的6-10月为水母皮炎的高发季节.由于本病地域性、季节性较强,且一般较少危及生命,所以医生和患者均未给与重视.近年来,随着海产品的捕捞加工和养殖,海水浴场和沿海旅游景点的开发,水母皮炎的发病逐年增多,给游人和沿海居民带来不便.本文就近10余年来有关水母皮炎的研究进展进行综述如下.     

沿海某部官兵海训致海蜇蜇伤的治疗

2006年7～8月,我军某部官兵在闽东海训时先后被海蜇(水母)蜇伤5例,经及时的诊治,均治愈,现报告如下.     

夏日蛇虫叮咬急救法

蜂蜇伤急救方法:用消毒针将叮在肉内的断刺剔出,然后用力掐住被蜇伤的部分,用嘴反复吸吮,以吸出毒素。如果身边暂时没有药物,可用肥皂水充分洗患处,然后再涂些食醋或柠檬。被蜂蜇伤20分钟后无症状者,可以放心。若情况严     

水母毒素相关SCI文献分析

运用NCBI数据库pubmed检索窗口检索1965～2008年间在水母毒素研究方面发表的SCI论文,按关键词、期刊、年代、作者、实验室、国别等进行了系统的统计和分析,反映了水母毒素相关研究的方向、热点、水平和发展趋势。     

局麻药封闭在蜂蛰伤治疗中的临床应用体会

目的早期快速局部处理蜂蜇伤对患者症状缓解和毒素排除具有积极意义。方法收集临床蜂蛰伤40例病例,年龄在30~80岁,全部到医院第一时间采用局麻药局部封闭法,观察临床治疗效果及预后。结果全部治疗效果满意,35例门诊治疗1次回家,5例蜂群蜇伤治疗3~4 d回家,随访无异常及其他不适。结论局麻药封闭治疗蜂蜇伤的局部处理对中和毒素,减轻过敏症状、应激反应和伤口止痛缓解症状效果都是确切的安全的,实施应用简单方便。     

Immunological and toxinological responses to jellyfish stings

Just over a century ago, animal responses to injections of jellyfish extracts unveiled the phenomenon of anaphylaxis. Yet, until very recently, understanding of jellyfish sting toxicity has remained limited. Upon contact, jellyfish stinging cells discharge complex venoms, through thousands of barbed tubules, into the skin resulting in painful and, potentially, lethal envenomations. This review examines the immunological and toxinological responses to stings by prominent species of jellyfish including Physalia sp (Portuguese Man-o-War, Blue-bottle), Cubozoan jellyfish including Chironex fleckeri, several Carybdeids including Carybdea arborifera and Alatina moseri, Linuche unguiculta (Thimble jellyfish), a jellyfish responsible for Irukandji syndrome (Carukia barnesi) and Pelagia noctiluca. Jellyfish venoms are composed of potent proteinaceous porins (cellular membrane pore-forming toxins), neurotoxic peptides, bioactive lipids and other small molecules whilst the tubules contain ancient collagens and chitins. We postulate that immunologically, both tubular structural and functional biopolymers as well as venom components can initiate innate, adaptive, as well as immediate and delayed hypersensitivity reactions that may be amenable to topical anti-inflammatory-immunomodifier therapy. The current challenge for immunotoxinologists is to deconstruct the actions of venom components to target therapeutic modalities for sting treatment.     

A case of jellyfish sting

Jellyfish sting may result in a wide range of symptoms from common erythematous urticarial eruptions to the rare box-jelly induced acute respiratory failure. In Taiwan, with the increasing frequency of international travel, cases of jellyfish sting to foreigners are on the rise. We report a case of jellyfish sting with the rare presentation of painless contact dermatitis. A 38-y-o man accidentally stepped on a sea urchin with his right foot during scuba diving in a beach in Thailand. Traditional therapy with vinegar was applied on the lesion. However, when he returned to Taiwan, erythematous patches on the left thigh with linear radiations to the leg were discovered. The skin lesions had bizzare shapes and showed progressive change. No pain or numbness was noticed. Jellyfish stingwas suspected, topical medications were applied, and the patient recovered without complication. Jellyfish stings usually result in a painful erythematous eruption. In this case, though the lesion involved a large surface, there was no pain. Delayed diagnosis of jellyfish sting was due to the atypical presentation and the physician's unfamiliarity to the Thai jellyfish sting. Awareness to the wide spectrum of jellyfish sting symptoms should be promoted.     

Interactions of cnidarian toxins with the immune system

Cnidarians comprise four classes of toxic marine animals: Anthozoa, Cubozoa, Scyphozoa and Hydrozoa. They are the largest and probably the oldest phylum of toxic marine animals. Any contact with a cnidarian, especially the box jellyfish (Chironex fleckeri), can be fatal, but most cnidarians do not possess sufficiently strong venomous apparatus to penetrate the human skin, whereas others rarely come into contact with human beings. Only a small, almost negligible percentage of the vast wealth of cnidarian toxins has been studied in detail. Many polypeptide cnidarian toxins are immunogenic, and cross-reactivity between several jellyfish venoms has been reported. Cnidarians also possess components of innate immunity, and some of those components have been preserved in evolution. On the other hand, cnidarian toxins have already been used for the design of immunotoxins to treat cancer, whereas other cnidarian toxins can modulate the immune system in mammals, including man. This review will focus on a short overview of cnidarian toxins, on the innate immunity of cnidarians, and on the mode of action of cnidarian toxins which can modulate the immune system in mammals. Emphasis is palced on those toxins which block voltage activated potassium channels in the cells of the immune system.     

Modeling the emetic potencies of food-borne trichothecenes by benchmark dose methodology

Trichothecene mycotoxins commonly co-contaminate cereal products. They cause immunosuppression, anorexia, and emesis in multiple species. Dietary exposure to such toxins often occurs in mixtures. Hence, if it were possible to determine their relative toxicities and assign toxic equivalency factors (TEFs) to each trichothecene, risk management and regulation of these mycotoxins could become more comprehensive and simple. We used a mink emesis model to compare the toxicities of deoxynivalenol, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, nivalenol, fusarenon-X, HT-2 toxin, and T-2 toxin. These toxins were administered to mink via gavage and intraperitoneal injection. The United States Environmental Protection Agency (EPA) benchmark dose software was used to determine benchmark doses for each trichothecene. The relative potencies of each of these toxins were calculated as the ratios of their benchmark doses to that of DON. Our results showed that mink were more sensitive to orally administered toxins than to toxins administered by IP. T-2 and HT-2 toxins caused the greatest emetic responses, followed by FX, and then by DON, its acetylated derivatives, and NIV. Although these results provide key information on comparative toxicities, there is still a need for more animal based studies focusing on various endpoints and combined effects of trichothecenes before TEFs can be established.     

Proteomic Changes during the Dermal Toxicity Induced by Nemopilema nomurai Jellyfish Venom in HaCaT Human Keratinocyte

Jellyfish venom is well known for its local skin toxicities and various lethal accidents. The main symptoms of local jellyfish envenomation include skin lesions, burning, prickling, stinging pain, red, brown, or purplish tracks on the skin, itching, and swelling, leading to dermonecrosis and scar formation. However, the molecular mechanism behind the action of jellyfish venom on human skin cells is rarely understood. In the present study, we have treated the human HaCaT keratinocyte with Nemopilema nomurai jellyfish venom (NnV) to study detailed mechanisms of actions behind the skin symptoms after jellyfish envenomation. Using two-dimensional gel electrophoresis (2-DE) and matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF/MS), cellular changes at proteome level were examined. The treatment of NnV resulted in the decrease of HaCaT cell viability in a concentration-dependent manner. Using NnV (at IC₅₀), the proteome level alterations were determined at 12 h and 24 h after the venom treatment. Briefly, 70 protein spots with significant quantitative changes were picked from the gels for MALDI-TOF/MS. In total, 44 differentially abundant proteins were successfully identified, among which 19 proteins were increased, whereas 25 proteins were decreased in the abundance levels comparing with their respective control spots. DAPs involved in cell survival and development (e.g., Plasminogen, Vinculin, EMILIN-1, Basonuclin2, Focal adhesion kinase 1, FAM83B, Peroxisome proliferator-activated receptor-gamma co-activator 1-alpha) decreased their expression, whereas stress or immune response-related proteins (e.g., Toll-like receptor 4, Aminopeptidase N, MKL/Myocardin-like protein 1, hypoxia up-regulated protein 1, Heat shock protein 105 kDa, Ephrin type-A receptor 1, with some protease (or peptidase) enzymes) were up-regulated. In conclusion, the present findings may exhibit some possible key players during skin damage and suggest therapeutic strategies for preventing jellyfish envenomation.     

Biochemical and molecular characterisation of cubozoan protein toxins

Class Cubozoa includes several species of box jellyfish that are harmful to humans. The venoms of box jellyfish are stored and discharged by nematocysts and contain a variety of bioactive proteins that are cytolytic, cytotoxic, inflammatory or lethal. Although cubozoan venoms generally share similar biological activities, the diverse range and severity of effects caused by different species indicate that their venoms vary in protein composition, activity and potency. To date, few individual venom proteins have been thoroughly characterised, however, accumulating evidence suggests that cubozoan jellyfish produce at least one group of homologous bioactive proteins that are labile, basic, haemolytic and similar in molecular mass (42-46 kDa). The novel box jellyfish toxins are also potentially lethal and the cause of cutaneous pain, inflammation and necrosis, similar to that observed in envenomed humans. Secondary structure analysis and remote protein homology predictions suggest that the box jellyfish toxins may act as α-pore-forming toxins. However, more research is required to elucidate their structures and investigate their mechanism(s) of action. The biological, biochemical and molecular characteristics of cubozoan venoms and their bioactive protein components are reviewed, with particular focus on cubozoan cytolysins and the newly emerging family of box jellyfish toxins.     

Preparation and Neutralization Efficacy of Novel Jellyfish Antivenoms against Cyanea nozakii Toxins

Jellyfish stings are a common issue globally, particularly in coastal areas in the summer. Victims can suffer pain, itching, swelling, shock, and even death. Usually, hot water, vinegar, or alumen is used to treat the normal symptoms of a jellyfish sting. However, a specific antivenom may be an effective treatment to deal with severe jellyfish stings. Cyanea nozakii often reach a diameter of 60 cm and are responsible for hundreds of thousands of stings per year in coastal Chinese waters. However, there has been no specific C. nozakii antivenom until now, and so the development of this antivenom is very important. Herein, we collected C. nozakii antisera from tentacle extract venom immunized rabbits and purified the immunoglobulin (IgG) fraction antivenom (AntiCnTXs). Subsequently, two complete procedures to produce a refined F(ab’)₂ type of antivenom (F(ab’)₂-AntiCnTXs) and Fab type of antivenom (Fab-AntiCnTXs) by multiple optimizations and purification were established. The neutralization efficacy of these three types of antivenoms was compared and analyzed in vitro and in vivo, and the results showed that all types of antibodies displayed some neutralization effect on the lethality of C. nozakii venom toxins, with the neutralization efficacy as follows: F(ab’)₂-AntiCnTXs ≥ AntiCnTXs > Fab-AntiCnTXs. This study describes the preparation of novel C. nozakii jellyfish antivenom preparations towards the goal of developing a new, effective treatment for jellyfish stings.     

Isolation and in vitro partial characterization of hemolytic proteins from the nematocyst venom of the jellyfish Stomolophus meleagris

Jellyfish venom contains various toxins and can cause itching, edema, muscle aches, shortness of breath, blood pressure depression, shock or even death after being stung. Hemolytic protein is one of the most hazardous components in the venom. The present study investigated the hemolytic activity of the nematocyst venom from jellyfish Stomolophus meleagris. Anion exchange chromatography, DEAE Sepharose Fast Flow, and gel filtration chromatography, Superdex200 had been employed to isolate hemolytic proteins from the nematocyst venom of jellyfish S. meleagris. Hemolysis of chicken red blood cells was used to quantify hemolytic potency of crude nematocyst venom and chromatography fractions during the purification process. Native-PAGE profile displayed one protein band in the purified hemolytic protein (SmTX); however, two protein bands with apparent molecular weights of ～45 kDa and 52 kDa were observed in the reducing SDS–PAGE analysis. Approximately 70 μg/mL of SmTX caused 50% hemolysis (HU₅₀) of the erythrocyte suspension. The hemolytic activity of SmTX was shown to be temperature and pH dependent, with the optimum temperature and pH being 37 °C and pH 5.0. The present study is the first report of isolation and partial characterization of hemolytic proteins from the nematocyst venom of the jellyfish S. meleagris. The mechanism of the hemolytic activity of SmTX is not clear and deserves further investigation.     

Sea wasp (Chironex fleckeri) antivenene: neutralizing potency against the venom of three other jellyfish species

Neutralization of the lethal, haemolytic and dermonecrotic effects of the venom of the cubomedusan jellyfish Chiropsalmus quadrigatus by antivenenes prepared against the milked venom of Chironex fleckeri was studied. In vitro neutralization of all three properties was obtained, and passive immunization of mice with the antivenene reduced dermonecrosis but did not protect against the lethal effect. Whole tentacle extracts of Chironex fleckeri and of an unidentified tropical cubomedusan, which may contain additional toxins from the tentacle substances, were neutralized by the antivenene. It is concluded that the antivenene would be useful for treatment of envenomation by either of the related cubomedusan species dangerous to man. Venoms of two other jellyfish species, Physalia physalis and Chrysaora quinquecirrha, which have toxic effects similar in some respects to the box jellyfish, were not neutralized by the antivenene.