Insulin-Like Growth Factor 2 As a Possible Neuroprotective Agent and Memory Enhancer-Its Comparative Expression, Processing and Signaling in Mammalian CNS.

A number of studies performed on rodents suggest that insulin-like growth factor 2 (IGF-2) or its analogs may possibly be used for treating some conditions like Alzheimer's disease, Huntington's disease, autistic spectrum disorders or aging-related cognitive impairment. Still, for translational research a comparative knowledge about the function of IGF-2 and related molecules in model organisms (rats and mice) and humans is necessary. There is a number of important differences in IGF-2 signaling between species. In the present review we emphasize species-specific patterns of IGF-2 expression in rodents, humans and some other mammals, using, among other sources, publicly available transcriptomic data. We provide a detailed description of Igf2 mRNA expression regulation and pre-pro-IGF-2 protein processing in different species. We also summarize the function of IGF-binding proteins. We describe three different receptors able to bind IGF-2 and discuss the role of IGF-2 signaling in learning and memory, as well as in neuroprotection. We hope that comprehensive understanding of similarities and differences in IGF-2 signaling between model organisms and humans will be useful for development of more effective medicines targeting IGF-2 receptors.

Involvement of CASP9 (caspase 9) in IGF2R/CI-MPR endosomal transport.

Recently, we reported that increased expression of CASP9 pro-domain, at the endosomal membrane in response to HSP90 inhibition, mediates a cell-protective effect that does not involve CASP9 apoptotic activity. We report here that a non-apoptotic activity of endosomal membrane CASP9 facilitates the retrograde transport of IGF2R/CI-MPR from the endosomes to the trans-Golgi network, indicating the involvement of CASP9 in endosomal sorting and lysosomal biogenesis. CASP9-deficient cells demonstrate the missorting of CTSD (cathepsin D) and other acid hydrolases, accumulation of late endosomes, and reduced degradation of bafilomycin A1-sensitive proteins. In the absence of CASP9, IGF2R undergoes significant degradation, and its rescue is achieved by the re-expression of a non-catalytic CASP9 mutant. This endosomal activity of CASP9 is potentially mediated by herein newly identified interactions of CASP9 with the components of the endosomal membrane transport complexes. These endosomal complexes include the retromer VPS35 and the SNX dimers, SNX1-SNX5 and SNX2-SNX6, which are involved in the IGF2R retrieval mechanism. Additionally, CASP9 interacts with HGS/HRS/ESCRT-0 and the CLTC (clathrin heavy chain) that participate in the initiation of the endosomal ESCRT degradation pathway. We propose that endosomal CASP9 inhibits the endosomal membrane degradative subdomain(s) from initiating the ESCRT-mediated degradation of IGF2R, allowing its retrieval to transport-designated endosomal membrane subdomain(s). These findings are the first to identify a cell survival, non-apoptotic function for CASP9 at the endosomal membrane, a site distinctly removed from the cytoplasmic apoptosome. Via its non-apoptotic endosomal function, CASP9 impacts the retrograde transport of IGF2R and, consequently, lysosomal biogenesis.Abbreviations: ACTB: actin beta; ATG7: autophagy related 7; BafA1: bafilomycin A1; CASP: caspase; CLTC/CHC: clathrin, heavy chain; CTSD: cathepsin D; ESCRT: endosomal sorting complexes required for transport; HEXB: hexosaminidase subunit beta; HGS/HRS/ESCRT-0: hepatocyte growth factor-regulated tyrosine kinase substrate; IGF2R/CI-MPR: insulin like growth factor 2 receptor; ILV: intraluminal vesicles; KD: knockdown; KO: knockout; M6PR/CD-MPR: mannose-6-phosphate receptor, cation dependent; MEF: murine embryonic fibroblasts; MWU: Mann-Whitney U test; PepA: pepstatin A; RAB7A: RAB7, member RAS oncogene family; SNX-BAR: sorting nexin dimers with a Bin/Amphiphysin/Rvs (BAR) domain each; TGN: trans-Golgi network; TUBB: tubulin beta; VPS26: VPS26 retromer complex component; VPS29: VPS29 retromer complex component; VPS35: VPS35 retromer complex component.

Quantification of low drug concentration in model formulations with multivariate analysis using surface enhanced Raman chemical imaging.

This paper reports the application of surface enhanced Raman chemical imaging (SER-CI) as a potentially non-destructive quantitative analytical method for the investigation of model pharmaceutical formulations containing the active pharmaceutical ingredient (API) in low concentrations (0.5-2%). The application of chemometric techniques for processing the spectra enables the determination of API distribution in products of different concentrations. In addition, the applied multivariate curve resolution can be proper method to identify unexpected contaminants in illicit drugs. The drastic Raman signal enhancement in the presence of silver nanoparticles provides significantly improved calibration accuracy and, at the same time, radically decreased image acquisition time compared to conventional Raman chemical imaging.

Evaluación de la actividad biológica de extractos de semillas de Crotalaria pallida (cascabelito) sobre el modelo Drosophila melanogaster / Evaluation of the biological activity of extracts from Crotalaria pallida (streaked rattlepod) seeds using the Drosophila melanogaster model

Introducción: la búsqueda de metabolitos de origen natural, con actividad biológica promisoria, particularmente la actividad insecticida, es un blanco interesante en las investigaciones sobre productos naturales. Objetivos: evaluar la bioactividad de extractos de diferente polaridad de semillas de Crotalaria pallida Aiton sobre el modelo biológico Drosophila melanogaster. Métodos: la bioactividad de los extractos de diferente polaridad de semillas secas de C. pallida se evalúo por ingestión en el modelo biológico; permitiendo purificar y determinar la estructura química del principio activo usando RMN. Resultados: la bioactividad expresada resultó de dos tipos; uno causó la inhibición de los estados larvarios, evidenciada con la disminución del número de pupas de los tratamientos con respecto a los controles no tratados, la relación dosis-respuesta permitió calcular una CI 50 de 156,47 ppm; el otro efecto inhibió el paso pupa-adulto, disminuyendo el número de adultos de los tratamientos frente a los controles, estableciéndose una CI50 de 7,95 ppm. Con el uso de diferentes ensayos de RMN se determinó el alcaloide usaramina como responsable de esta actividad biológica. Conclusiones : la bioactividad de los extractos de polaridad media/baja permitió el aislamiento de un metabolito con actividad insecticida promisoria, manifestada con la inhibición del normal desarrollo del ciclo de vida de D. melanogaster, el extracto no exhibe actividad sobre la oviposición, en el intervalo de concentraciones evaluado; a bajas concentraciones inhibe la eclosión de pupas y a altas concentraciones afecta el desarrollo de las larvas; actividades que se mantienen al probar el metabolito purificado.

Introduction: the search for metabolites of natural origin with promising biological -particularly insecticidal- activity, is an interesting target for research about natural products. Objectives: evaluate the bioactivity of extracts of varying polarity from Crotalaria pallida Aiton seeds using the Drosophila melanogaster biological model. Methods: an evaluation was conducted of the bioactivity of extracts of varying polarity from dry C. pallida seeds by ingestion into the biological model, with the purpose of purifying and determining the chemical structure of the active principle through NMR spectroscopy. Results: two types of bioactivity were expressed. One caused inhibition of larval stages, evidenced in a smaller number of pupae in treatment controls with respect to non-treatment controls. The dose-response relationship allowed estimation of a CI50 of 156.47 ppm. The other effect inhibited progress from pupa to adult, reducing the number of adults in the treatment vs. control groups, with an CI50 of 7.95 ppm. With the use of various NMR assays, it was determined that the alkaloid usaramine was responsible for this biological activity. Conclusions: the bioactivity of extracts of medium / low polarity permitted the isolation of a metabolite with promising insecticidal activity, manifested in the inhibition of the normal development of the life cycle of D. melanogaster. The extract does not show any activity on oviposition in the concentration range studied. At low concentrations it inhibits the eclosion of pupae, whereas at high concentrations it affects larval development. Both activities remained when the purified metabolite was tested.