RESUMO
OBJECTIVES: To determine whether histologic chorioamnionitis is associated with changes in gene expression of TLR-1, -2, -4 and -6, and to describe the localization of these receptors in fetal membranes. STUDY DESIGN: A total of 135 amniochorion membranes with or without histologic chorioamnionitis from preterm or term deliveries were included. Fragments of membranes were submitted to total RNA extraction. RNA was reverse transcribed and the quantification of TLRs expression measured by real time PCR. RESULTS: All amniochorion membranes expressed TLR-1 and TLR-4, whereas 99.1% of membranes expressed TLR-2 and 77.4% expressed TLR-6. TLR-1 and TLR-2 expressions were significantly higher in membranes with histologic chorioamnionitis as compared to membranes without chorioamnionitis in preterm pregnancies (p=0.003 and p<0.001, respectively). Among the membranes of term pregnancies there were no differences in the expressions of such receptors regardless of inflammatory status. Regarding TLR-4 and TLR-6 expression, there was no difference among membranes with or without histologic chorioamnionitis, regardless gestational age at delivery. TLR-1, TLR-2, TLR-4 and TLR-6 expressions were observed in amniotic epithelial, chorionic and decidual cells. CONCLUSION: Amniochorion membranes express TLR-1, TLR-2, TLR-4 and TLR-6 and increased expression of TLR-1 and TLR-2 is related to the presence of histologic chorioamnionitis in preterm pregnancies. This study provides further evidence that amniochorion membranes act as a mechanical barrier to microorganisms and as components of the innate immune system.
Assuntos
Corioamnionite/genética , Receptores Toll-Like/biossíntese , Adulto , Âmnio/metabolismo , Corioamnionite/metabolismo , Córion/metabolismo , Estudos Transversais , Membranas Extraembrionárias/metabolismo , Feminino , Expressão Gênica , Humanos , Trabalho de Parto Prematuro/metabolismo , Gravidez , Nascimento Prematuro/fisiopatologia , Receptor 1 Toll-Like/biossíntese , Receptor 2 Toll-Like/biossíntese , Receptor 4 Toll-Like/biossíntese , Receptor 6 Toll-Like/biossínteseRESUMO
INTRODUCTION: Pattern-recognition receptors (PRRs), which include Toll-like Receptor (TLRs) and Nacht leucine-rich repeat proteins (NLRP/NALPs), are molecules of innate immunity able to recognize a wide variety of ligands present in microorganisms and human tissues. Adipocytes (fat cells) may play an important role in the physiological regulation of their own immune responses via TLRs. During obesity, the inflammatory pathway is triggered and insulin responsiveness is altered in fat tissue as a result of TLR4 activation by dietary lipids. OBJECTIVE: Here, we investigate if other PRR family members could also participate in the inflammatory processes in the adipose tissue of obese mice. METHODS: The mRNA expression of TLRs, the NLRP3-inflammasome (NLRP3, ASC, caspase-1 and IL-lbeta), IL-6, and TNFα in the hepatic and adipose tissues of mice fed with a high fat diet (HFD) were studied by RT-PCR. RESULTS: Adipose tissue from mice fed with a HFD had decreased expression levels of TLR2, TLR6 and TLR7 and was similar to the pattern in hepatic tissue HFD mice. IL-6 and TNF-α expression also were decreased in adipose tissue of mice fed with a HFD. NLRP3-inflammasome expression was not modified. CONCLUSION: These results suggest that the low expression of TLR2, and TLR6 in the mice fed with a HFD could be regulating the inflammation induced by the diet employed in this study.