Efeito do tratamento da H. pylori na expressão de citocinas e microRNAs associados ao processo inflamatório

• Ano de defesa: 2015
• Autor(a) principal: Rossi, Ana Flávia Teixeira [UNESP]
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual Paulista (Unesp)
• Palavras-chave em Português: Genetica humana; Expressão gênica; Helicobacter pylori; Mucosa gastrica - Inflamação; MicroRNAs; Citocinas
• Link de acesso: http://hdl.handle.net/11449/127802

Persistent infection by Helicobacter pylori (H. pylori) promotes chronic inflammation resulting in damage to the mucosa and the consequent development of gastric lesions as chronic gastritis. This bacterium and its virulence factors vacA and cagA influence the host immune response, deregulating the expression of inflammatory mediators and microRNAs (miRNAs), and activate pathways related to carcinogenic process. Thus, H. pylori eradication may have a key role to reverse precursor lesions, preventing malignant transformation. In the present study evaluated whether the eradication therapy of bacterium influences the mRNA and protein expression of inflammatory mediators (TNFA, IL6, IL1B, IL12A, IL2 and TGFBRII) and miRNAs (hsa-miR-103a-3p, hsa-miR-181c-5p, hsa-miR-370-3p, hsa-miR-375 and miR-223-3p) in H. pylori-positive chronic gastritis patients (Hp+) and compared with non-infected gastritis patients (Hp-). We also evaluated the relationship between the expression levels of miRNAs with of mRNA and protein and participation in interaction networks, as well as the influence of bacterial virulence factors cagA and vacA on these mediators. Relative quantification (RQ) of mRNA and miRNAs was performed by qPCR-real time using TaqMan® assay in 20 patients Hp- and 31 Hp+, which were also evaluated three months after eradication treatment of the bacterium. Genotyping of cagA and vacA was performed by PCR, while the protein expression was assessed by immunohistochemistry. Hp+ patients showed increased mRNA levels for TNFA, IL6, IL1B and IL12A, while for IL2 and TGFBRII as well as for the miRNAs miR-103, miR-181c, miR-370 and miR-375 it were decreased. After treatment, only TNFA and IL6 mRNA were significantly reduced and TGFBRII increased in eradicated patients (p<0.05). On the other hand, all miRNAs, except to miR-223, were significantly increased after bacterium eradication (p<0.05). In general, the...