of evidence shows that GWAS variants can destroy or create miRNA binding sites, hence, altering gene regulation and being associated with disease ( Wu et al . 2014 ). An illustrative example is the diabetes-associated gene HNF4A , which is regulated
Inês Cebola and Lorenzo Pasquali
Hseng-Kuang Hsu, Pei-Lin Shao, Ke-Li Tsai, Huei-Chuan Shih, Tzu-Ying Lee and Chin Hsu
, Sheriff et al. 2002 ). These results suggest that NMDA receptor activation is involved in transcriptional regulation of gene expression. Therefore, the present study was designed to identify a possible pathway leading to gene regulation and subsequent
Y Kazeto and J M Trant
and the pituitary during a reproductive cycle, and examined its mode of gene regulation. Materials and methods Animal and tissue collection Mature but inexperienced adult female channel catfish were directly
Sylvia C Hewitt, Wipawee Winuthayanon and Kenneth S Korach
gene. Initially, study of ER mediated gene regulation was carried out on a gene-by gene basis using a handful of known hormone regulated transcripts. Now, after numerous comprehensive analyses of hormonally regulated transcriptional profiles, using
Anke Schennink, Josephine F Trott, Rodrigo Manjarin, Danielle G Lemay, Bradley A Freking and Russell C Hovey
date of 5′ PRLR gene regulation across tissues for any species. Among the nine new first- PRLR exons we identified, we found that expression of one first exon, pE1.3, was primarily expressed in the kidney cortex and small intestine, where a homologous
Introduction The POMC gene has proven to be incredibly informative to study various aspects of gene regulation. Indeed, its restricted expression in two pituitary cell lineages provided the system to identify cell-restricted transcription
Leandro Nieto, Mariana Fuertes, Josefina Rosmino, Sergio Senin and Eduardo Arzt
Retinoic acid (RA), an active metabolite of Vitamin A, and bone morphogenetic protein 4 (BMP-4) pathways control the transcription of pro-opiomelanocortin (Pomc), the precursor of ACTH. We describe a novel mechanism by which RA and BMP-4 act together in the context of pituitary corticotroph tumoral cells to regulate Pomc transcription. BMP-4 and RA exert a potentiated inhibition on Pomc gene expression. This potentiation of the inhibitory action on Pomc transcription was blocked by the inhibitory SMADs of the BMP-4 pathway (SMAD6 and SMAD7), a negative regulator of BMP-4 signaling (TOB1) and a blocker of RA pathway (COUP-TFI). AtT-20 corticotrophinoma cells express RA receptors (RARB, RXRA and RXRG) which associate with factors of BMP-4 (SMAD4 and SMAD1) signaling cascade in transcriptional complexes that block Pomc transcription. COUP-TFI and TOB1 disrupt these complexes. Deletions and mutations of the Pomc promoter and a specific DNA-binding assay show that the complexes bind to the RARE site in the Pomc promoter. The enhanced inhibitory interaction between RA and BMP-4 pathways occurs also in another relevant corticotroph gene promoter, the corticotropin-releasing hormone receptor 1 (Crh-r1). The understanding of the molecules that participate in the control of corticotroph gene expression contribute to define more precise targets for the treatment of corticotrophinomas.
YL Hsieh, A Chatterjee, JT Chien and JY Yu
The cDNAs encoding pituitary glycoprotein hormone alpha subunits (PGHalphas) of two species of duck (Muscovy duck, Cairina moschata and Pekin duck, Anas platyrhynchos domesticus) were cloned and sequenced to better understand the phylogenic diversity and evolution of PGHalpha molecules in vertebrates. Oligonucleotide primers were designed and used for reverse transcription PCR (RT-PCR) amplification of PGHalpha cDNA fragments from total cellular RNA of pituitary glands. The remaining sequences were completed by rapid amplification of the cDNA ends. The nucleotide sequence of isolated PGHalpha cDNA of both ducks are identical, including 81 bp of 5' untranslated region (UTR), 360 bp of coding region, and 272 bp of 3'-UTR followed by a 13 bp poly(A)(+) tract. The total number of amino acids deduced from the cDNA of the duck PGHalpha is 120 with a signal peptide of 24 amino acids and a mature protein of 96 amino acids. PGHalphas of the ducks (order Anseriformes) share 96% homology of amino acid sequence in signal peptide, and 100% homology in mature proteins with chicken, quail and turkey (order Galliformes). Our data thus demonstrate identical inter-order homology of PGHalpha mature protein in birds. Ten cysteine residues, presumably forming five disulfide bonds within the alpha subunit, and four proline residues, presumably responsible for folding of the molecule, are conserved in the alpha subunit of ducks. Northern blot analysis revealed that PGHalpha mRNA is expressed only in the pituitary. In order to study factors regulating the gene expression of PGHalpha mRNA, duck pituitary fragments were incubated with GnRH, TRH, testosterone, or triiodothyronine (T(3)). GnRH and TRH increased, while testosterone and T(3) decreased, PGHalpha mRNA levels. This is the first report in birds of TRH up-regulation and down-regulation by testosterone and T(3) under in vitro conditions. The present study demonstrates both ducks have the same cDNA nucleotide and deduced amino acid sequences in the PGHalpha subunit, exhibiting identical inter-genus homology within the family of Anatidae. The findings from mRNA expression work suggest that hypothalamic GnRH and TRH up-regulate, while testosterone and T(3) down-regulate, PGHalpha gene expression in ducks.
J M Gunnersen, P J Roche, G W Tregear and R J Crawford
Relaxin is a peptide hormone which is produced in human reproductive tissues including the ovary and prostate gland. Little is known of the molecular events regulating relaxin gene transcription. We have studied this question using gene transfer of relaxin promoter/reporter gene constructs into a relaxin-expressing cell line. A number of human cell lines expressed relaxin as detected by reverse transcription-PCR. In one of these lines, the prostate adenocarcinoma cell line LNCaP.FGC, relaxin mRNA was also detected by Northern blot analysis. The DNA sequences of the proximal 5′-flanking regions (∼900 nucleotides) of the two human relaxin genes, HI and H2, were determined. Deletion constructs containing portions of the 5′-flanking regions of HI and H2 linked to the bacterial chloramphenicol acetyl transferase reporter gene were prepared. The expression of the reporter gene constructs was analysed in the LNCaP.FGC cell line and the results of these transient transfection assays have led to the identification of positive and negative regulatory regions within the 5′-flanking DNA. A difference in activity of the H1 and H2 gene promoters in this prostate cell line was observed, with the H2 promoter being more active. This situation may mimic that occurring in vivo since the relaxin secreted from the prostate gland into seminal fluid is the product of the H2 gene.
Hui Wang, Wenjing Wu, Jun Duan, Ming Ma, Wei Kong, Yuannan Ke, Gang Li and Jingang Zheng
It has been reported that ischemic preconditioning (IPC) and adiponectin (APN) are cardioprotective in many cardiovascular disorders. However, whether APN mediates the effect of IPC on myocardial injury has not been elucidated. This study was conducted to investigate whether IPC affects myocardial ischemic injury by increasing APN expression. Male adult rats with cardiac knockdowns of APN and its receptors via intramyocardial small-interfering RNA injection were subjected to IPC and then myocardial infarction (MI) at 24 h after IPC. Globular APN (gAd) was injected at 10 min before MI. APN mRNA and protein levels in myocardium as well as the plasma APN concentration were markedly high at 6 and 12 h after IPC. IPC ameliorated myocardial injury as evidenced by improved cardiac functions and a reduced infarct size. Compared with the control MI group, rats in the IPC + MI group had elevated levels of left ventricular ejection fraction and fractional shortening and a smaller MI size (P < 0.05). However, the aforementioned protective effects were ameliorated in the absence of APN and APN receptors, followed by the inhibition of AMP-activated protein kinase (AMPK) phosphorylation, but reversed by gAd treatment in wild-type rats, and AMPK phosphorylation increased (P < 0.05). Overall, our results suggest that the cardioprotective effects of IPC are partially due to upregulation of APN and provide a further insight into IPC-mediated signaling effects.