Unité de Recherche en Biologie et Epidémiologie Parasitaires, Institut de Recherche Biomédicale des Armées, Antenne de Marseille, BP 60109, 13262 Marseille Cedex 07, France.
Malar J. 2010 May 25;9:141. doi: 10.1186/1475-2875-9-141.
The emergence of Plasmodium falciparum resistance to most anti-malarial compounds has highlighted the urgency to develop new drugs and to clarify the mechanisms of anti-malarial drugs currently used. Among them, doxycycline is used alone for malaria chemoprophylaxis or in combination with quinine or artemisinin derivatives for malaria treatment. The molecular mechanisms of doxycycline action in P. falciparum have not yet been clearly defined, particularly at the protein level.
A proteomic approach was used to analyse protein expression changes in the schizont stage of the malarial parasite P. falciparum following doxycycline treatment. A comparison of protein expression between treated and untreated protein samples was performed using two complementary proteomic approaches: two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) and isobaric tagging reagents for relative and absolute quantification (iTRAQ).
After doxycycline treatment, 32 and 40 P. falciparum proteins were found to have significantly deregulated expression levels by 2D-DIGE and iTRAQ methods, respectively. Although some of these proteins have been already described as being deregulated by other drug treatments, numerous changes in protein levels seem to be specific to doxycycline treatment, which could perturb apicoplast metabolism. Quantitative reverse transcription polymerase chain reaction (RT-PCR) was performed to confirm this hypothesis.
In this study, a specific response to doxycycline treatment was distinguished and seems to involve mitochondrion and apicoplast organelles. These data provide a starting point for the elucidation of drug targets and the discovery of mechanisms of resistance to anti-malarial compounds.
恶性疟原虫对大多数抗疟化合物的耐药性的出现，凸显了开发新药和阐明当前使用的抗疟药物机制的紧迫性。其中，多西环素单独用于疟疾化学预防，或与奎宁或青蒿素衍生物联合用于疟疾治疗。多西环素在恶性疟原虫中的作用机制尚未明确，特别是在蛋白质水平上。
采用蛋白质组学方法分析了多西环素处理后恶性疟原虫裂殖体阶段的蛋白表达变化。通过两种互补的蛋白质组学方法（二维荧光差异凝胶电泳（2D-DIGE）和等重同位素标记相对和绝对定量（iTRAQ））比较处理和未处理蛋白样品的蛋白表达。
多西环素处理后，2D-DIGE 和 iTRAQ 方法分别发现 32 种和 40 种恶性疟原虫蛋白的表达水平显著下调。虽然其中一些蛋白已被描述为其他药物处理所下调，但许多蛋白水平的变化似乎是多西环素处理所特有的，这可能会扰乱质体代谢。定量逆转录聚合酶链反应（RT-PCR）用于验证这一假设。
在这项研究中，区分出了对多西环素治疗的特异性反应，似乎涉及线粒体和质体细胞器。这些数据为阐明药物靶点和发现抗疟化合物耐药机制提供了起点。
