Molecular evolution and expression profile of the chemerine encoding gene RARRES2 in baboon and chimpanzee
BIOLOGICAL RESEARCH
Authors: Gonzalez-Alvarez, Rafael; de Lourdes Garza-Rodriguez, Maria; Delgado-Enciso, Ivan; Manuel Trevino-Alvarado, Victor; Canales-Del-Castillo, Ricardo; Elia Martinez-De-Villarreal, Laura; Lugo-Trampe, Angel; Elizabeth Tejero, Maria; Schlabritz-Loutsevitch, Natalia E.; Del Refugio Rocha-Pizana, Maria; Cole, Shelley A.; Resendez-Perez, Diana; Moises-Alvarez, Mario; Comuzzie, Anthony G.; Alberto Barrera-Saldana, Hugo; Garza-Guajardo, Raquel; Barboza-Quintana, Oralia; Pablo Rodriguez-Sanchez, Iram
Abstract
Background: Chemerin, encoded by the retinoic acid receptor responder 2 (RARRES2) gene is an adipocytesecreted protein with autocrine/paracrine functions in adipose tissue, metabolism and inflammation with a recently described function in vascular tone regulation, liver, steatosis, etc. This molecule is believed to represent a critical endocrine signal linking obesity to diabetes. There are no data available regarding evolution of RARRES2 in non-human primates and great apes. Expression profile and orthology in RARRES2 genes are unknown aspects in the biology of this multigene family in primates. Thus; we attempt to describe expression profile and phylogenetic relationship as complementary knowledge in the function of this gene in primates. To do that, we performed A RT-PCR from different tissues obtained during necropsies. Also we tested the hypotheses of positive evolution, purifying selection, and neutrality. And finally a phylogenetic analysis was made between primates RARRES2 protein. Results: RARRES2 transcripts were present in liver, lung, adipose tissue, ovary, pancreas, heart, hypothalamus and pituitary tissues. Expression in kidney and leukocytes were not detectable in either species. It was determined that the studied genes are orthologous. Conclusions: RARRES2 evolution fits the hypothesis of purifying selection. Expression profiles of the RARRES2 gene are similar in baboons and chimpanzees and are also phylogenetically related.
Expression and Regulation of Retinoic Acid Receptor Responders in the Human Placenta
REPRODUCTIVE SCIENCES
Authors: Huebner, Hanna; Hartner, Andrea; Rascher, Wolfgang; Strick, Reiner R.; Kehl, Sven; Heindl, Felix; Wachter, David L.; Beckmann, Matthias W.; Fahlbusch, Fabian B.; Ruebner, Matthias
Abstract
Introduction: Retinoic acid (RA) signaling through its receptors (RARA, RARB, RARG, and the retinoic X receptor RXRA) is essential for healthy placental and fetal development. An important group of genes regulated by RA are the RA receptor responders (RARRES1, 2, and 3). We set out to analyze their expression and regulation in healthy and pathologically altered placentas of preeclampsia (PE) and intrauterine growth restriction (IUGR) as well as in trophoblast cell lines. Methods: We performed immunohistochemical staining on placental sections and analyzed gene expression by real-time polymerase chain reaction. Additionally, we performed cell culture experiments and stimulated Swan71 and Jeg-3 cells with different RA derivates and 2-deoxy-5-azacytidine (AZA) to induce DNA demethylation. Results: RARRES1, 2, and 3 and RARA, RARB, RARG, and RXRA are expressed in the extravillous part of the placenta. RARRES1, RARA, RARG, and RXRA were additionally detected in villous cytotrophoblasts. RARRES gene expression was induced via activation of RARA, RARB, and RARG in trophoblast cells. RARRES1 was overexpressed in villous trophoblasts and the syncytiotrophoblast from PE placentas, but not in IUGR without PE. Promoter methylation was detectable for RARRES1 and RARB based on their sensitivity toward AZA treatment of trophoblast cell lines. Discussion: RARRES1, 2 and 3 are expressed in the functional compartments of the human placenta and can be regulated by RA. We hypothesize that the epigenetic suppression of trophoblast RARRES1 and RARB expression and the upregulation of RARRES1 in PE trophoblast cells suggest an involvement of environmental factors (eg, maternal vitamin A intake) in the pathogenesis of this pregnancy complication.