Agonist-biased signaling at the sst2A receptor: the multi-somatostatin analogs KE108 and SOM230 activate and antagonize distinct signaling pathways

Somatostatin analogs that activate the somatostatin subtype 2A (sst2A) receptor are used to treat neuroendocrine cancers because they inhibit tumor secretion and growth. Recently, new analogs capable of activating multiple somatostatin receptor subtypes have been developed to increase tumor responsiveness. We tested two such multi-somatostatin analogs for functional selectivity at the sst2A receptor: SOM230, which activates sst1, sst2, sst3, and sst5 receptors, and KE108, which activates all sst receptor subtypes. Both compounds are reported to act as full agonists at their target sst receptors. In sst2A-expressing HEK293 cells, somatostatin inhibited cAMP production, stimulated intracellular calcium accumulation, and increased ERK phosphorylation. SOM230 and KE108 were also potent inhibitors of cAMP accumulation, as expected. However, they antagonized somatostatin stimulation of intracellular calcium and behaved as partial agonists/antagonists for ERK phosphorylation. In pancreatic AR42J cells, which express sst2A receptors endogenously, SOM230 and KE108 were both full agonists for cAMP inhibition. However, although somatostatin increased intracellular calcium and ERK phosphorylation, SOM230 and KE108 again antagonized these effects. Distinct mechanisms were involved in sst2A receptor signaling in AR42J cells; pertussis toxin pretreatment blocked somatostatin inhibition of cAMP accumulation but not the stimulation of intracellular calcium and ERK phosphorylation. Our results demonstrate that SOM230 and KE108 behave as agonists for inhibition of adenylyl cyclase but antagonize somatostatin's actions on intracellular calcium and ERK phosphorylation. Thus, SOM230 and KE108 are not somatostatin mimics, and their functional selectivity at sst2A receptors must be considered in clinical applications where it may have important consequences for therapy.

Reliability, construct and criterion validity of the KIDSCREEN-10 score: a short measure for children and adolescents' well-being and health-related quality of life

Background To assess the criterion and construct validity of the KIDSCREEN-10 well-being and health-related quality of life (HRQoL) score, a short version of the KIDSCREEN-52 and KIDSCREEN-27 instruments. Methods The child self-report and parent report versions of the KIDSCREEN-10 were tested in a sample of 22,830 European children and adolescents aged 8–18 and their parents (n = 16,237). Correlation with the KIDSCREEN-52 and associations with other generic HRQoL measures, physical and mental health, and socioeconomic status were examined. Score differences by age, gender, and country were investigated. Results Correlations between the 10-item KIDSCREEN score and KIDSCREEN-52 scales ranged from r = 0.24 to 0.72 (r = 0.27–0.72) for the self-report version (proxy-report version). Coefficients below r = 0.5 were observed for the KIDSCREEN-52 dimensions Financial Resources and Being Bullied only. Cronbach alpha was 0.82 (0.78), test–retest reliability was ICC = 0.70 (0.67) for the self- (proxy-)report version. Correlations between other children self-completed HRQoL questionnaires and KIDSCREEN-10 ranged from r = 0.43 to r = 0.63 for the KIDSCREEN children self-report and r = 0.22–0.40 for the KIDSCREEN parent proxy report. Known group differences in HRQoL between physically/mentally healthy and ill children were observed in the KIDSCREEN-10 self and proxy scores. Associations with self-reported psychosomatic complaints were r = −0.52 (−0.36) for the KIDSCREEN-10 self-report (proxy-report). Statistically significant differences in KIDSCREEN-10 self and proxy scores were found by socioeconomic status, age, and gender. Conclusions Our results indicate that the KIDSCREEN-10 provides a valid measure of a general HRQoL factor in children and adolescents, but the instrument does not represent well most of the single dimensions of the original KIDSCREEN-52. Test–retest reliability was slightly below a priori defined thresholds.

Atorvastatin attenuates hepatic fibrosis in rats after bile duct ligation via decreased turnover of hepatic stellate cells

Activation of hepatic stellate cells (HSC) and transdifferentiation to myofibroblasts following liver injury is the main culprit for hepatic fibrosis. Myofibroblasts show increased proliferation, migration, contraction, and production of extracellular matrix (ECM). In vitro, HMG-CoA reductase inhibitors (statins) inhibit proliferation and induce apoptosis of myofibroblastic HSC. To investigate the antifibrotic effects of atorvastatin in vivo we used bile duct ligated rats (BDL).

The venom composition of the parasitic wasp Chelonus inanitus resolved by combined expressed sequence tags analysis and proteomic approach

Background Parasitic wasps constitute one of the largest group of venomous animals. Although some physiological effects of their venoms are well documented, relatively little is known at the molecular level on the protein composition of these secretions. To identify the majority of the venom proteins of the endoparasitoid wasp Chelonus inanitus (Hymenoptera: Braconidae), we have randomly sequenced 2111 expressed sequence tags (ESTs) from a cDNA library of venom gland. In parallel, proteins from pure venom were separated by gel electrophoresis and individually submitted to a nano-LC-MS/MS analysis allowing comparison of peptides and ESTs sequences. Results About 60% of sequenced ESTs encoded proteins whose presence in venom was attested by mass spectrometry. Most of the remaining ESTs corresponded to gene products likely involved in the transcriptional and translational machinery of venom gland cells. In addition, a small number of transcripts were found to encode proteins that share sequence similarity with well-known venom constituents of social hymenopteran species, such as hyaluronidase-like proteins and an Allergen-5 protein. An overall number of 29 venom proteins could be identified through the combination of ESTs sequencing and proteomic analyses. The most highly redundant set of ESTs encoded a protein that shared sequence similarity with a venom protein of unknown function potentially specific of the Chelonus lineage. Venom components specific to C. inanitus included a C-type lectin domain containing protein, a chemosensory protein-like protein, a protein related to yellow-e3 and ten new proteins which shared no significant sequence similarity with known sequences. In addition, several venom proteins potentially able to interact with chitin were also identified including a chitinase, an imaginal disc growth factor-like protein and two putative mucin-like peritrophins. Conclusions The use of the combined approaches has allowed to discriminate between cellular and truly venom proteins. The venom of C. inanitus appears as a mixture of conserved venom components and of potentially lineage-specific proteins. These new molecular data enrich our knowledge on parasitoid venoms and more generally, might contribute to a better understanding of the evolution and functional diversity of venom proteins within Hymenoptera.

Identification of bracovirus particle proteins and analysis of their transcript levels at the stage of virion formation

http://www.ncbi.nlm.nih.gov/pubmed/20554796

Impact of Thrombolysis on Stroke Outcome at 12 Months in a Population: The Bern Stroke Project

Thrombolysis improves outcome of patients with acute ischemic stroke, but it is unknown whether thrombolysis has a measurable effect on long-term outcome in a defined population.

Early occurrence of lung adenocarcinoma and breast cancer after radiotherapy of a chest wall sarcoma in a patient with a de novo germline mutation in TP53

We report a 26-year-old female patient who was diagnosed within 4 years with chest sarcoma, lung adenocarcinoma, and breast cancer. While her family history was unremarkable, DNA sequencing of TP53 revealed a germline de novo non-sense mutation in exon 6 p.Arg213X. One year later, she further developed a contralateral ductal carcinoma in situ, and 18 months later a jaw osteosarcoma. This case illustrates the therapeutic pitfalls in the care of a young cancer patient with TP53 de novo germline mutations and the complications related to her first-line therapy. Suggestion is made to use the less stringent Chompret criteria for germline TP53 mutation screening. Our observation underlines the possibly negative effect of radiotherapy in generating second tumors in patients with a TP53 mutation. We also present a review of six previously reported cases, comparing their cancer phenotypes with those generally produced by TP53 mutations.

Alba-domain proteins of Trypanosoma brucei are cytoplasmic RNA-binding proteins that interact with the translation machinery

Trypanosoma brucei and related pathogens transcribe most genes as polycistronic arrays that are subsequently processed into monocistronic mRNAs. Expression is frequently regulated post-transcriptionally by cis-acting elements in the untranslated regions (UTRs). GPEET and EP procyclins are the major surface proteins of procyclic (insect midgut) forms of T. brucei. Three regulatory elements common to the 3' UTRs of both mRNAs regulate mRNA turnover and translation. The glycerol-responsive element (GRE) is unique to the GPEET 3' UTR and regulates its expression independently from EP. A synthetic RNA encompassing the GRE showed robust sequence-specific interactions with cytoplasmic proteins in electromobility shift assays. This, combined with column chromatography, led to the identification of 3 Alba-domain proteins. RNAi against Alba3 caused a growth phenotype and reduced the levels of Alba1 and Alba2 proteins, indicative of interactions between family members. Tandem-affinity purification and co-immunoprecipitation verified these interactions and also identified Alba4 in sub-stoichiometric amounts. Alba proteins are cytoplasmic and are recruited to starvation granules together with poly(A) RNA. Concomitant depletion of all four Alba proteins by RNAi specifically reduced translation of a reporter transcript flanked by the GPEET 3' UTR. Pulldown of tagged Alba proteins confirmed interactions with poly(A) binding proteins, ribosomal protein P0 and, in the case of Alba3, the cap-binding protein eIF4E4. In addition, Alba2 and Alba3 partially cosediment with polyribosomes in sucrose gradients. Alba-domain proteins seem to have exhibited great functional plasticity in the course of evolution. First identified as DNA-binding proteins in Archaea, then in association with nuclear RNase MRP/P in yeast and mammalian cells, they were recently described as components of a translationally silent complex containing stage-regulated mRNAs in Plasmodium. Our results are also consistent with stage-specific regulation of translation in trypanosomes, but most likely in the context of initiation.

Deep resequencing of GWAS loci identifies independent rare variants associated with inflammatory bowel disease

More than 1,000 susceptibility loci have been identified through genome-wide association studies (GWAS) of common variants; however, the specific genes and full allelic spectrum of causal variants underlying these findings have not yet been defined. Here we used pooled next-generation sequencing to study 56 genes from regions associated with Crohn's disease in 350 cases and 350 controls. Through follow-up genotyping of 70 rare and low-frequency protein-altering variants in nine independent case-control series (16,054 Crohn's disease cases, 12,153 ulcerative colitis cases and 17,575 healthy controls), we identified four additional independent risk factors in NOD2, two additional protective variants in IL23R, a highly significant association with a protective splice variant in CARD9 (P < 1 × 10(-16), odds ratio ≈ 0.29) and additional associations with coding variants in IL18RAP, CUL2, C1orf106, PTPN22 and MUC19. We extend the results of successful GWAS by identifying new, rare and probably functional variants that could aid functional experiments and predictive models.