Grupo de Genômica e Biologia Computacional, Instituto Nacional de Ciência e Tecnologia em Doenças Tropicais and Centro de Excelência em Bioinformática- CEBio, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz - FIOCRUZ, Belo Horizonte, Minas Gerais, Brazil.
Biologia Parasitária, Departamento de Ensino, Pavilhão Arthur Neiva, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, Rio de Janeiro, Brazil; Laboratório de Helmintologia Romero Lascasas Porto, Departamento de Patologia e Laboratórios, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil.
PLoS Negl Trop Dis. 2014 Jun 19;8(6):e2949. doi: 10.1371/journal.pntd.0002949. eCollection 2014 Jun.
Protein kinases are proven targets for drug development with an increasing number of eukaryotic Protein Kinase (ePK) inhibitors now approved as drugs. Mitogen-activated protein kinase (MAPK) family members connect cell-surface receptors to regulatory targets within cells and influence a number of tissue-specific biological activities such as cell proliferation, differentiation and survival. However, the contributions of members of the MAPK pathway to schistosome development and survival are unclear.
METHODOLOGY/PRINCIPAL FINDINGS: We employed RNA interference (RNAi) to elucidate the functional roles of five S. mansoni genes (SmCaMK2, SmJNK, SmERK1, SmERK2 and SmRas) involved in MAPK signaling pathway. Mice were injected with post-infective larvae (schistosomula) subsequent to RNAi and the development of adult worms observed. The data demonstrate that SmJNK participates in parasite maturation and survival of the parasites, whereas SmERK are involved in egg production as infected mice had significantly lower egg burdens with female worms presenting underdeveloped ovaries. Furthermore, it was shown that the c-fos transcription factor was overexpressed in parasites submitted to RNAi of SmERK1, SmJNK and SmCaMK2 indicating its putative involvement in gene regulation in this parasite's MAPK signaling cascade.
We conclude that MAPKs proteins play important roles in the parasite in vivo survival, being essential for normal development and successful survival and reproduction of the schistosome parasite. Moreover SmERK and SmJNK are potential targets for drug development.
蛋白激酶是药物开发的既定靶点，越来越多的真核蛋白激酶 (ePK) 抑制剂现已被批准为药物。丝裂原活化蛋白激酶 (MAPK) 家族成员将细胞表面受体与细胞内的调节靶标连接起来，并影响许多组织特异性的生物学活性，如细胞增殖、分化和存活。然而，MAPK 途径成员对血吸虫发育和存活的贡献尚不清楚。
方法/主要发现：我们采用 RNA 干扰 (RNAi) 技术阐明了 MAPK 信号通路中五个 S. mansoni 基因 (SmCaMK2、SmJNK、SmERK1、SmERK2 和 SmRas) 的功能作用。在 RNAi 后，用感染后的幼虫（尾蚴）注射小鼠，并观察成虫的发育。数据表明 SmJNK 参与寄生虫的成熟和寄生虫的存活，而 SmERK 则参与产卵，因为受感染的小鼠的卵负荷明显降低，而雌性蠕虫的卵巢发育不良。此外，还表明 c-fos 转录因子在接受 SmERK1、SmJNK 和 SmCaMK2 RNAi 的寄生虫中过度表达，表明其在寄生虫的 MAPK 信号级联中可能参与基因调控。
我们得出结论，MAPK 蛋白在寄生虫体内的存活中发挥着重要作用，对于寄生虫的正常发育以及成功的生存和繁殖至关重要。此外，SmERK 和 SmJNK 是药物开发的潜在靶点。
