Penicillin-induced convulsions have preferential effects on transmitter glutamate pools in rat neostriatum

Convulsant doses of penicillin and elevated ambient pressure of 41 bar enhance the excitability of neurons. Their effects have been studied in neostriatal tissue with methods allowing differentiation between transmitter and metabolic glutamate pools. Levels of glutamate (Glu), glutamine (Gln), aspartate (Asp); -aminobutyric acid and taurine were measured in the intact and decorticated neostriatum and parieto-occipital cortex of rats with a unilateral frontal cortex ablation. Intravenous infusion of penicillin at 1 bar decreased the neostriatal Glu content in the intact but not in the decorticated hemisphere. Pressure of 41 bar significantly decreased the level of Asp in the decorticated side only. Infusion of penicillin at 41 bar reduced the levels of Glu by 20.1% and Gln by 21.0% in the intact neostriatum only, whereas it decreased the Asp level in both sides as compared to control. The cortical Glu content was decreased only after infusion of penicillin at 41 bar. The results suggest that intravenous penicillin has a more pronounced effect on transmitter than on metabolic Glu pools in rat brain.     

Teaching Industrial Ecology to Graduate Students: Experiences at the Norwegian University of Science and Technology

We reflect on our experiences in developing and teaching industrial ecology to interdisciplinary classes of M.Sc. and Ph.D. students. During a three-year period different ways of teaching a course in industrial ecology were tested. We conclude that an industrial ecology course has positive effects on the students' ability to acquire a holistic understanding of life-cycle environmental performance, a skill much in demand by industry. Such a course should be based on problem-oriented learning. We recommend the use of thematically-focused seminars with time for both lectures and workshops. We found that substantial participation by teachers from different disciplines and partners from industry and government is very effective. Such a course also facilitates a broader process of change within the university. Implementing industrial ecology in the university requires a joint effort and collaboration among various faculties and departments, where research activities, student projects, as well as regular student teaching and tutoring, must be complementary elements of a major interdisciplinary strategy. Such a strategy has been employed at the Norwegian University of Science and Technology (NTNU) since the first initiatives in this area were taken in 1993, and this has led to our present more comprehensive Industrial Ecology Programme (IndEcol).     

Genetic and Molecular Functional Characterization of Variants within TNFSF13B,a Positional Candidate Preeclampsia Susceptibility Gene on 13q

Background

Preeclampsia is a serious pregnancy complication, demonstrating a complex pattern of inheritance. The elucidation of genetic liability to preeclampsia remains a major challenge in obstetric medicine. We have adopted a positional cloning approach to identify maternal genetic components, with linkages previously demonstrated to chromosomes 2q, 5q and 13q in an Australian/New Zealand familial cohort. The current study aimed to identify potential functional and structural variants in the positional candidate gene TNFSF13B under the 13q linkage peak and assess their association status with maternal preeclampsia genetic susceptibility.

Methodology/Principal Findings

The proximal promoter and coding regions of the positional candidate gene TNFSF13B residing within the 13q linkage region was sequenced using 48 proband or founder individuals from Australian/New Zealand families. Ten sequence variants (nine SNPs and one single base insertion) were identified and seven SNPs were successfully genotyped in the total Australian/New Zealand family cohort (74 families/480 individuals). Borderline association to preeclampsia (p = 0.0153) was observed for three rare SNPs (rs16972194, rs16972197 and rs56124946) in strong linkage disequilibrium with each other. Functional evaluation by electrophoretic mobility shift assays showed differential nuclear factor binding to the minor allele of the rs16972194 SNP, residing upstream of the translation start site, making this a putative functional variant. The observed genetic associations were not replicated in a Norwegian case/control cohort (The Nord-Trøndelag Health Study (HUNT2), 851 preeclamptic and 1,440 non-preeclamptic women).

Conclusion/Significance

TNFSF13B has previously been suggested to contribute to the normal immunological adaption crucial for a successful pregnancy. Our observations support TNFSF13B as a potential novel preeclampsia susceptibility gene. We discuss a possible role for TNFSF13B in preeclampsia pathogenesis, and propose the rs16972194 variant as a candidate for further functional evaluation.     

Endosome-to-Golgi transport is regulated by protein kinase A type II alpha

Studies of RII alpha-deficient B lymphoid cells and stable transfectants expressing the type II alpha regulatory subunit (RII alpha) of cAMP-dependent protein kinase (PKA), which is targeted to the Golgi-centrosomal area, reveal that the presence of a Golgi-associated pool of PKA type II alpha mediates a change in intracellular transport of the plant toxin ricin. The transport of ricin from endosomes to the Golgi apparatus, measured as sulfation of a modified ricin (ricin sulf-1), increased in RII alpha-expressing cells when PKA was activated. However, not only endosome-to-Golgi transport, but also retrograde ricin transport to the endoplasmic reticulum (ER), measured as sulfation and N-glycosylation of another modified ricin (ricin sulf-2), seemed to be increased in cells expressing RII alpha in the presence of a cAMP analog, 8-(4-chlorophenylthio)-cAMP. Thus, PKA type II alpha seems to be involved in both endosome-to-Golgi and Golgi-to-ER transport. Because ricin, after being retrogradely transported to the ER, is translocated to the cytosol, where it inhibits protein synthesis, we also investigated the influence of RII alpha expression on ricin toxicity. In agreement with the other data obtained, 8-(4-chlorophenylthio)-cAMP and RII alpha were found to sensitize cells to ricin, indicating an increased transport of ricin to the cytosol. In conclusion, our results demonstrate that transport of ricin from endosomes to the Golgi apparatus and further to the ER is regulated by PKA type II alpha isozyme.     

Contrasting patterns of gene diversity between microsatellites and mitochondrial SNPs in farm and wild Atlantic salmon

Levels of genetic variability at 12 microsatellite loci and 19 single nucleotide polymorphisms in mitochondrial DNA were studied in four farm strains and four wild populations of Atlantic salmon. Within populations, the farm strains showed significantly lower allelic richness and expected heterozygosity than wild populations at the 12 microsatellite loci, but a significantly higher genetic variability with respect to observed number of haplotypes and haplotype diversity in mtDNA. Significant differences in allele- and haplotype-frequencies were observed between farm strains and wild populations, as well as between different farm strains and between different wild populations. The large genetic differentiation at mitochondrial DNA between wild populations (F_ST = 0.24), suggests that the farm strains attained a high mitochondrial genetic variability when created from different wild populations seven generations ago. A large proportion of this variability remains despite an expected lower effective population size for mitochondrial than nuclear DNA. This is best explained by the particular mating schemes in the breeding programmes, with 2–4 females per male. Our observations suggest that for some genetic polymorphisms farm populations might currently hold equal or higher genetic variability than wild populations, but lower overall genetic variability. In the short-term, genetic interactions between escaped farm salmon and wild salmon might increase genetic variability in wild populations, for some, but not most, genetic polymorphisms. In the long term, further losses of genetic variability in farm populations are expected for all genetic polymorphisms, and genetic variability in wild populations will be reduced if escapes of farm salmon continue.     

Insulin and TNF alpha induce expression of the forkhead transcription factor gene Foxc2 in 3T3-L1 adipocytes via PI3K and ERK 1/2-dependent pathways

We have recently identified the winged helix/forkhead gene Foxc2 as a key regulator of adipocyte metabolism that counteracts obesity and diet-induced insulin resistance. This study was performed to elucidate the hormonal regulation of Foxc2 in adipocytes. We find that TNF alpha and insulin induce Foxc2 mRNA in differentiated 3T3-L1 cells with the kinetics of an immediate early response (1-2 h with 100 ng/ml insulin or 5 ng/ml TNF alpha). This induction is, in both cases, attenuated by the PI3K inhibitor wortmannin as well as the MAPK kinase inhibitor PD98059. Furthermore, we show that stimulation of 3T3-L1 adipocytes with phorbol-12-myristate-13-acetate or 8-(4-chlorophenyl)thio-cAMP induces the expression of Foxc2. Interestingly, we find that the basal level of Foxc2 mRNA is down-regulated whereas hormonal responsiveness increases during differentiation of 3T3-L1 from preadipocytes to adipocytes. At the protein level, immunoblots with Foxc2 antibody demonstrated an induction of Foxc2 by insulin and TNF alpha in nuclear extracts of 3T3-L1 adipocytes. EMSA of nuclear proteins from phorbol-12-myristate-13-acetate- and TNF alpha-treated 3T3-L1 adipocytes using a forkhead consensus oligonucleotide revealed specific binding of a Foxc2/DNA complex. In conclusion, our data suggest that insulin and TNF alpha regulate the expression of Foxc2 via a PI3K- and ERK 1/2-dependent pathway in 3T3-L1 adipocytes. Also, signaling pathways downstream of PKA and PKC induce the expression of Foxc2 mRNA.     

Synthesis and pharmacological properties of novel hydrophilic 5-HT4 receptor antagonists

Serotonin (5-hydroxytryptamine, 5-HT) is an important signalling molecule in the human body. The 5-HT(4) serotonin receptor, coupled to the G protein G(s), plays important physiological and pathophysiological roles in the heart, urinary bladder, gastrointestinal tract and the adrenal gland. Both 5-HT(4) antagonists and agonists have been developed in the aim to treat diseases in these organs. 5-HT(4) agonists might have beneficial effects in the central nervous system (CNS) and therefore, 5-HT(4) antagonists might cause CNS side effects. In this study, we have developed new amphoteric 5-HT(4) antagonists. A series of cyclic indole amide derivatives possessing an oxazine ring and a piperidine alkane carboxylic acid side chain and the corresponding prodrug esters were synthesized and their binding to 5-HT(4) receptors and antagonist properties were evaluated. In addition, an indole ester without the oxazine ring and the corresponding indole amide derivatives were also tested. Octanol-water distribution (LogD(Oct7.4)) was tested for some of the synthesized ligands. The main structure-affinity characteristics of the 5-HT(4) compounds tested were that the prodrug esters show higher affinity than their corresponding free acids, indole esters show higher affinity than the corresponding amides and ligands containing the oxazine ring in the indole skeleton show higher affinity than indole derivatives not containing the ring. One representative prodrug ester and its corresponding free acid were tested for binding on a panel of receptors and showed preserved selectivity for the 5-HT(4) receptor. These new molecules may be useful to target peripheral 5-HT(4) receptors.