RESUMEN
Helicobacter pylori employs unique methods to colonize the stomach, which induces chronic inflammation. It is also able to avoid eradication by macrophages and other immune cells. Leukocyte cell-derived chemotaxin 2 (LECT2), a multi-functional cytokine involved in many pathological conditions, has recently been shown to activate macrophages via the CD209a receptor. Therefore, we aimed to investigate the effects of LECT2 on H. pylori-infected macrophages. Macrophages were treated with recombinant LECT2, and both their ability to kill H. pylori and produce nitric oxide were analyzed. Western blot was performed to determine nuclear translocation and protein phosphorylation of p65, a subunit of nuclear factor (NF)-κB. Transfection experiments were performed to analyze the signaling pathway of LECT2 in macrophages. We found that treatment with LECT2 enhanced H. pylori killing and nitric oxide production in macrophages. In addition, DNA-binding activity and nuclear translocation of p65 were up-regulated by LECT2 treatment. Furthermore, we found that NF-κB activation by LECT2 was mediated by Raf-1 in macrophages, and Raf-1 phosphorylation was specifically altered in response to LECT2. Moreover, LECT2 induced Ser28 phosphorylation in the intracellular domain of CD209a. CD209a Ser28 phosphorylation was required for LECT2-induced Raf-1 and NF-κB activation in RAW264.7 macrophages. Our study showed that the effects of LECT2 on H. pylori killing and nitric oxide production were dependent on CD209a phosphorylation, Raf-1, and NF-κB activation. Together, these results demonstrate for the first time that exposure to LECT2 can modulate specific intracellular mechanisms downstream of CD209a to enhance H. pylori killing and nitric oxide production in macrophages.
Asunto(s)
Infecciones por Helicobacter/genética , Péptidos y Proteínas de Señalización Intercelular/genética , Proteínas Recombinantes/genética , Factor de Transcripción ReIA/biosíntesis , Animales , Moléculas de Adhesión Celular/genética , Moléculas de Adhesión Celular/inmunología , Infecciones por Helicobacter/inmunología , Infecciones por Helicobacter/microbiología , Helicobacter pylori/inmunología , Helicobacter pylori/patogenicidad , Humanos , Péptidos y Proteínas de Señalización Intercelular/farmacología , Lectinas Tipo C/genética , Lectinas Tipo C/inmunología , Macrófagos/inmunología , Ratones , Óxido Nítrico/biosíntesis , Óxido Nítrico/genética , Fosforilación , Células RAW 264.7 , Receptores de Superficie Celular/genética , Receptores de Superficie Celular/inmunología , Proteínas Recombinantes/farmacología , Transducción de Señal/genética , Estómago/inmunología , Estómago/microbiología , Factor de Transcripción ReIA/genética , Activación Transcripcional/genética , TransfecciónRESUMEN
Congenital heart disease (CHD) is the most common birth abnormality, but the etiology of CHD is unknown. ISL1 may play a fundamental role in cardiac morphogenesis, and mutations of this gene could cause CHD. To evaluate whether genetic variations of ISL1 are associated with CHD in Chinese Han people, polymerase chain reaction restriction fragment-length polymorphism and SNaPshot were used to examine 9 polymorphisms of ISL1 in 233 patients with CHD as well as 288 healthy controls. We found that one SNP (rs1017) in ISL1 was significantly associated with simple CHD. Genetic variation of ISL1 was confirmed to be associated with the risk of CHD. ISL1 is related to the atrial septal defect group and the ventricular septal defect group, and the genotypes were associated with the occurrence of CHD in the dominant mode of inheritance. We concluded that rs1017 contributed to the risk of CHD in Chinese Han people, and ISL1 may be involved in the formation and development of the heart.