Gene expression profile of human placenta from T. Cruzi infected mothers

Background. More than one million women in fertile age are infected with Trypanosoma cruzi worldwide. Anti-T.cruzi seropositivity in mothers has been associated with adverse pregnancy outcome but there is still a knowledge gap regarding this effect. Our aim was to compare the gene expression profile of term placental environment from T. cruzi seropositive (SP) and seronegative (SN) mothers. Methods. A RNA-Seq was performed in 9 pools of 2 different placental RNA samples each: 3 belonging to placentas from SN and 6 from SP. Each pool consisted of a binomial of a female/male newborn and a vaginal/caesarean delivery. None of the newborns resulted infected. Results. Only 42 genes showed a significant fold change between SP and SN groups. Among the down-regulated genes were KISS1 and CGB5. In the up-regulated genes group were: KIF12, HLA-G, PRG2, TAC3, FN1 and ATXN3L. To identify pathways significantly associated with maternal T. cruzi-infection, a gene-set association analysis was implemented. The placental environment transcriptomic profile of SP consisted of an enrichment in immunological genes sets (inflammatory response and lymphocytic activation were over-expressed) whereas numerous biosynthetic processes were down-regulated. Conclusions. It is worth noting that several differentially expressed genes in SP placentas code for proteins associated to preeclampsia and miscarriage. This first transcriptomics study in human term placental environment from non-infected deliveries shows a placental response that may affect the faetus while protecting it from the parasite infection; this host response could be responsible for the low rate of congenital transmission observed in human chronic Chagas disease. Background. More than one million women in fertile age are infected with Trypanosoma cruzi worldwide. Anti-T.cruzi seropositivity in mothers has been associated with adverse pregnancy outcome but there is still a knowledge gap regarding this effect. Our aim was to compare the gene expression profile of term placental environment from T. cruzi seropositive (SP) and seronegative (SN) mothers. Methods. A RNA-Seq was performed in 9 pools of 2 different placental RNA samples each: 3 belonging to placentas from SN and 6 from SP. Each pool consisted of a binomial of a female/male newborn and a vaginal/caesarean delivery. None of the newborns resulted infected. Results. Only 42 genes showed a significant fold change between SP and SN groups. Among the down-regulated genes were KISS1 and CGB5. In the up-regulated genes group were: KIF12, HLA-G, PRG2, TAC3, FN1 and ATXN3L. To identify pathways significantly associated with maternal T. cruzi-infection, a gene-set association analysis was implemented. The placental environment transcriptomic profile of SP consisted of an enrichment in immunological genes sets (inflammatory response and lymphocytic activation were over-expressed) whereas numerous biosynthetic processes were down-regulated. Conclusions. It is worth noting that several differentially expressed genes in SP placentas code for proteins associated to preeclampsia and miscarriage. This first transcriptomics study in human term placental environment from non-infected deliveries shows a placental response that may affect the faetus while protecting it from the parasite infection; this host response could be responsible for the low rate of congenital transmission observed in human chronic Chagas disease. Overall design: Serodiagnosis of pregnant women was done by means of conventional serological methods and carried out by the respective health centres based on routine assays. In maternal and umbilical cord blood samples T. cruzi presence was tested using multiplex Real Time PCR as previously described [6]. Maternal infection with other pathogens that produce congenital transmission and adverse pregnancy outcome were considered as exclusion criteria, as well as missing data or incorrect sampling. Fresh normal placentas were obtained after labour from vaginal or caesarean deliveries and placed within 24 hours at 4°C. Each placenta was dissected and the middle section [7] at 2 cm distance from the umbilical cord was isolated and placed into RNAlater solution (Applied Biosystems, Foster City, CA). Total RNA was extracted with TRIzol reagent (Invitrogen, Carlsbad, CA) and stored at -80°C until used. Transcriptomic studies. A RNA-Seq experiment was done in 9 pools of 2 different placental RNA samples each: 3 pools (C1, C2 and C3) belonging to placentas from seronegative mothers (SN) and 6 pools (TC4 to TC9) from seropositive mothers (SP). Each pool consisted of a binomial of a female/male newborn and a vaginal/caesarean delivery. The cDNA Libraries were prepared according to Illumina''s TruSeq Stranded Total RNA with Ribo-Zero Gold for Human and a Hiseq 2.500 Illumina platform with 100 bp paired-end reads was used for sequencing

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Juiz NA, Torrejón I, Burgos M, Torres AMF, Duffy T, Cayo NM, Tabasco A, Salvo M, Longhi SA, Schijman AG