UMR PAM A, Valmis team, 2 rue Angélique Ducoudray, BP 37013, 21070, Dijon Cedex, France.
Aix Marseille Univ, IRD, AP-HM, SSA, VITROME, Marseille, France.
Parasit Vectors. 2019 May 27;12(1):266. doi: 10.1186/s13071-019-3526-4.
Currently, there is no satisfactory treatment for leishmaniases, owing to the cost, mode of administration, side effects and to the increasing emergence of drug resistance. As a consequence, the proteins involved in Leishmania apoptosis seem a target of choice for the development of new therapeutic tools against these neglected tropical diseases. Indeed, Leishmania cell death, while phenotypically similar to mammalian apoptosis, is very peculiar, involving no homologue of the key mammalian apoptotic proteins such as caspases and death receptors. Furthermore, very few proteins involved in Leishmania apoptosis have been identified.
We identified a protein involved in Leishmania apoptosis from a library of genes overexpressed during Leishmania differentiation during which autophagy occurs. Indeed, the gene was overexpressed when L. major cell death was induced by curcumin or miltefosine. Furthermore, its overexpression increased L. major curcumin- and miltefosine-induced apoptosis. This gene, named LmjF.22.0600, whose expression is dependent on the expression of the metacaspase, another apoptotic protein, encodes a putative acetyltransferase.
This new protein, identified as being involved in Leishmania apoptosis, will contribute to a better understanding of Leishmania death, which is needed owing to the absence of a satisfactory treatment against leishmaniases. It will also allow a better understanding of the original apoptotic pathways of eukaryotes in general, while evidence of the existence of such pathways is accumulating.
目前,由于成本、给药方式、副作用以及耐药性的不断出现,尚无令人满意的利什曼病治疗方法。因此,涉及利什曼细胞凋亡的蛋白质似乎是开发针对这些被忽视的热带病的新治疗工具的首选靶标。事实上,虽然利什曼细胞死亡在表型上与哺乳动物凋亡相似,但非常特殊,不涉及细胞凋亡的关键哺乳动物蛋白如半胱天冬酶和死亡受体的同源物。此外,涉及利什曼细胞凋亡的蛋白质很少被鉴定。
我们从利什曼原虫分化过程中过度表达的基因文库中鉴定出一种与利什曼原虫凋亡有关的蛋白质。事实上,当用姜黄素或米替福新诱导 L. major 细胞死亡时,该基因表达上调。此外,其过表达增加了 L. major 姜黄素和米替福新诱导的细胞凋亡。该基因名为 LmjF.22.0600,其表达依赖于另一种凋亡蛋白——类半胱天冬酶的表达,编码一种假定的乙酰转移酶。
这种新鉴定出的与利什曼原虫凋亡有关的蛋白质将有助于更好地理解利什曼原虫的死亡,由于缺乏针对利什曼病的令人满意的治疗方法,这是必要的。它还将有助于更好地理解真核生物原始凋亡途径,因为越来越多的证据表明存在这种途径。