Cloning, expression pattern and heterologous expression of recombinant glycoprotein hormone subunits-related molecules GPA2 and GPB5 from rat, bovine and amphioxus

International audienc

Effects of rapeseed meal-glucosinolates on thyroid metabolism and feed utilization in rainbow trout

Two rapeseed meals (RM1 and RM2), containing glucosinolates at a concentration of 26 and 40 micromol/g, respectively, were incorporated at increasing levels (10, 20, and 30% for RM1 and 30 and 50% for RM2) in diets of juvenile rainbow trout. Disturbances in the thyroid axis appeared after 14 days of feeding (with a dietary incorporation level of 10%). The dietary supplementation with T(3) or iodine induced an increase in plasma T(3) levels, compared to that in fish fed the RM diets, and reduced the deleterious effect of RM on growth. When trout were reared in seawater, there was also a slight increase in thyroid hormone levels. TSH treatment had no effect on the thyroid hormone plasma levels. The incorporation of 30% of RM1, which induced a lower dietary content of toxic compounds than RM2, led to a rapid decrease of plasma T(4) and T(3) levels, but growth was affected only after 6 months of feeding. During these studies, the deiodinase activities responded in a complex manner to restore plasma and tissue levels of T(3).status: publishe

Toward the identification of viral cap-methyltransferase inhibitors by fluorescence screening assay

International audienceTwo highly pathogenic human coronaviruses associated with severe respiratory syndromes emerged since the beginning of the century. The severe acute respiratory syndrome SARS-coronavirus (CoV) spread first in southern China in 2003 with about 8000 infected cases in few months. Then in 2012, the Middle East respiratory syndrome (MERS-CoV) emerged from the Arabian Peninsula giving a still ongoing epidemic associated to a high fatality rate. CoVs are thus considered a major health threat. This is especially true as no vaccine nor specific therapeutic are available against either SARS-or MERS-CoV. Therefore, new drugs need to be identified in order to develop antiviral treatments limiting CoV repli-cation. In this study, we focus on the nsp14 protein, which plays a key role in virus replication as it methylates the RNA cap structure at the N7 position of the guanine. We developed a high-throughput N7-MTase assay based on Homogenous Time Resolved Fluorescence (HTRF ®) and screened chemical libraries (2000 compounds) on the SARS-CoV nsp14. 20 compounds inhibiting the SARS-CoV nsp14 were further evaluated by IC 50 determination and their specificity was assessed toward flavivirus-and human cap N7-MTases. Our results reveal three classes of compounds: 1) molecules inhibiting several MTases as well as the dengue virus polymerase activity unspecifically, 2) pan MTases inhibitors targeting both viral and cellular MTases, and 3) inhibitors targeting one viral MTase more specifically showing however activity against the human cap N7-MTase. These compounds provide a first basis towards the development of more specific inhibitors of viral methyltransferases

Supplementary Material for: Identification and Analysis of Two Novel Sites of Rat GnRH Receptor Gene Promoter Activity: The Pineal Gland and Retina

<b><i>Background and Aims:</i></b> In mammals, activation of pituitary GnRH receptor (GnRHR) by hypothalamic GnRH increases the synthesis and secretion of LH and FSH, which, in turn, regulate gonadal functions. However, GnRHR gene <i>(Gnrhr)</i> expression is not restricted to the pituitary. <b><i>Methods:</i></b> To gain insight into the extrapituitary expression of <i>Gnrhr</i>, a transgenic mouse model that expresses the human placental alkaline phosphatase reporter gene driven by the rat <i>Gnrhr</i> promoter was created. <b><i>Results:</i></b> This study shows that the rat <i>Gnrhr</i> promoter is operative in two functionally related organs, the pineal gland, as early as embryonic day (E) 13.5, and the retina where activity was only detected at E17.5. Accordingly, <i>Gnrhr</i> mRNA were present in both tissues. Transcription factors known to regulate <i>Gnrhr</i> promoter activity such as the LIM homeodomain factors LHX3 and ISL1 were also detected in the retina. Furthermore, transient transfection studies in CHO and gonadotrope cells revealed that OTX2, a major transcription factor in both pineal and retina cell differentiation, is able to activate the <i>Gnrhr</i> promoter together with either CREB or PROP1, depending on the cell context. <b><i>Conclusion:</i></b> Rather than using alternate promoters, <i>Gnrhr</i> expression is directed to diverse cell lineages through specific associations of transcription factors acting on distinct response elements along the same promoter. These data open new avenues regarding GnRH-mediated control of seasonal and circadian rhythms in reproductive physiology

The viral capping enzyme nsP1: a novel target for the inhibition of chikungunya virus infection

The chikungunya virus (CHIKV) has become a substantial global health threat due to its massive re-emergence, the considerable disease burden and the lack of vaccines or therapeutics. We discovered a novel class of small molecules ([1,2,3]triazolo[4,5-d]pyrimidin-7(6H)-ones) with potent in vitro activity against CHIKV isolates from different geographical regions. Drug-resistant variants were selected and these carried a P34S substitution in non-structural protein 1 (nsP1), the main enzyme involved in alphavirus RNA capping. Biochemical assays using nsP1 of the related Venezuelan equine encephalitis virus revealed that the compounds specifically inhibit the guanylylation of nsP1. This is, to the best of our knowledge, the first report demonstrating that the alphavirus capping machinery is an excellent antiviral drug target. Considering the lack of options to treat CHIKV infections, this series of compounds with their unique (alphavirus-specific) target offers promise for the development of therapy for CHIKV infections.status: publishe