Novel insights into biological roles of inducible cAMP early repressor ICER.

ICER corresponds to a group of alternatively spliced Inducible cAMP Early Repressors with high similarity, but multiple roles, including in circadian rhythm, and are involved in attenuation of cAMP-dependent gene expression. We present experimental and in silico data revealing biological differences between the isoforms with exon gamma (ICER) or without it (ICERγ). Both isoforms are expressed in the liver and the adrenal glands and can derive from differential splicing. In adrenals the expression is circadian, with maximum at ZT12 and higher amplitude of Icerγ. In the liver, the expression of Icerγ is lower than Icer in the 24 h time frame. Icer mRNA has a delayed early response to forskolin. The longer ICER protein binds to three DNA grooves of the Per1 promoter, while ICERγ only to two, as deduced by molecular modelling. This is in line with gel shift competition assays showing stronger binding of ICER to Per1 promotor. Only Icerγ siRNA provoked an increase of Per1 expression. In conclusion, we show that ICER and ICERγ have distinct biochemical properties in tissue expression, DNA binding, and response to forskolin. Data are in favour of ICERγ as the physiologically important form in hepatic cells where weaker binding of repressor might be preferred in guiding the cAMP-dependent response.

Detection of the activator cAMP responsive element modulator (CREM) isoform ortholog proteins in porcine spermatids and sperm.

It is necessary to obtain basic information on transcription factors expressed in the spermatids of livestock to determine mechanisms of defective spermiogenesis. In this study, we characterized the activator cAMP responsive element modulator (CREM) ortholog isoforms in porcine testicular germ cells and ejaculated sperm. At least two kinds of porcine activator CREM τ family ortholog mRNAs were more strongly expressed in the testis than in kidney or liver. The activator CREM isoform ortholog proteins were localized in nuclei of round spermatids and around nuclei of elongated spermatids. Furthermore, approximately 34% of ejaculated sperm had the activator CREM isoform ortholog proteins at their connecting piece. This is apparently the first report demonstrating the expression and localization of the activator CREM isoform ortholog proteins in spermatids and ejaculated sperm of a livestock species.

Cefditoren versus ceftazidime in inducer-substrate combinations for the evaluation of AmpC production in a disc approximation test

Objetivo: Evaluar el cefditoren en combinaciones inductor-substrato para la detección de inducción de AmpC.Métodos: 100 aislados clínicos (25 P. aeruginosa, 25 E.cloacae, 14 M. morganii, 13 S. marcescens, 12 C. freundii,7 P. rettgeri, and 4 E. aerogenes) se ensayaron por el métodode disco Kirby-Bauer utilizando discos de cefditoren yceftazidima como substratos y de cefditoren e imipenemcomo inductores.Resultados: Ninguna cepa mostró inducción de AmpCcon la combinación cefditoren-ceftazidima como inductorsubstrato.La combinación de imipenem-cefditoren comoinductor-substrato no fue adecuada para evaluar las cepasde P. aeruginosa ya que no hubo halo de inhibición alrededordel disco de cefditoren. En las enterobacterias que sepudieron evaluar (por presentar halo de inhibición alrededordel substrato), se detectó AmpC inducible en 48 de 63(76.2%) con cefditoren, y en 33 de 68 (48.5%) de los aisladoscon ceftazidima como substrato. Se detectó un númerosignificantivamente (p= 0.013) mayor de productores deAmpC con cefditoren que con ceftazidima (76.2% vs.48.5%), debido a las diferencias encontradas en E. cloacae(72.8% vs. 21.7%; p= 0.0009) y S. marcescens (100% vs.54.5%; p= 0.03). Las reducciones medias del diámetro alrededorde los discos del substrato fueron mayores para cefditoren(4.17 mm) que para ceftazidima (3.79 mm), alcanzandosignificación estadística (p<0.05) en proteáceasindol-positivo: M. morganii (5.32 mm vs. 3.92 mm) y P.rettgeri (3.47 mm vs. 2.64 mm).Conclusión: Cefditoren no presentó capacidad de inducción, y utilizado como substrato (con imipenem comoinductor) ofreció una tasa de detección de AmpC inducibleen enterobacterias superior de la de la combinación imipenem-ceftazidima, principalmente en Enterobacter spp. ySerratia spp., con mayores reducciones del diámetro enproteáceas indol-positivo(AU)

Objective: To evaluate cefditoren in inducer-substratecombinations to screen for AmpC induction.Methods: 100 clinical isolates (25 P. aeruginosa, 25 E.cloacae, 14 M. morganii, 13 S. marcescens, 12 C. freundii, 7 P.rettgeri, and 4 E. aerogenes) were tested by the Kirby-Bauerdisc approximation method using cefditoren and ceftazidimediscs as substrates, and cefditoren and imipenem discs asinducers.Results: None of the strains showed induction of AmpCwith cefditoren-ceftazidime as inducer-substrate combination.Imipenem-cefditoren as inducer-substrate combination wasnot useful for evaluating strains of P. aeruginosa since noinhibition zones surrounding the cefditoren disc were found.Among evaluable enterobacteria (those showing substrateinhibition zone), inducible Amp C was detected in 48 out of 63(76.2%) with cefditoren, and in 33 out of 68 (48.5%) isolateswith ceftazidime as substrate. Significantly (p= 0.013) highernumber of AmpC producers were detected with cefditorenversus ceftazidime (76.2% vs. 48.5%), due to the differencesfound for E. cloacae (72.8% vs. 21.7%; p= 0.0009) and S.marcescens (100% vs. 54.5%; p= 0.03). Higher meanreductions of diameters around substrate discs were found forcefditoren (4.17 mm) vs. ceftazidime (3.79 mm), reachingstatistical significance (p<0.05) for indol-positive proteae: M.morganii (5.32 mm vs. 3.92 mm) and P. rettgeri (3.47 mm vs.2.64 mm).Conclusion: Cefditoren showed no induction capability,and when used as substrate (with imipenem as inducer) itoffered detection rates of AmpC inducible enterobacteriahigher than the imipenem-ceftazidime combination, mainly forEnterobacter spp. and Serratia spp., with higher diameterreductions for indol-positive proteae(AU)

Effects of Rubus coreanus on sperm parameters and cAMP-responsive element modulator (CREM) expression in rat testes.

Rubi Fructus (RF), the dried, unripe fruit of Rubus coreanus M IQ. (Rosaceae), has been used to improve male reproductive function in traditional Korean medicine. In this study, we investigated the effects of RF on sperm parameters and expression of cAMP-responsive element modulator (CREM), which has a crucial role in spermatogenesis. RF was administered to 8-week-old male Wistar rats for 56 consecutive days (1.0 g/kg, daily, p.o.). Sperm analysis, RT-PCR, and Western blot assays were then carried out. The RF-treated animals showed significant increases in the weight of the testes, epididymal sperm count, and sperm motility compared to the control group. RF also increased the expression of CREM at both the mRNA and protein levels. These results suggest that RF may improve male fertility by enhancing spermatogenesis.