Role of hormones in the regulation of RACK1 expression as a signaling checkpoint in immunosenescence

Immunosenescence defines the decline in immune function that occurs with aging. This has been associated, at least in part, with defective cellular signaling via protein kinase C (PKC) signal transduction pathways. Our data suggest reduced PKC activation and consequently reduced response to lipopolysaccharide (LPS) stimulation and cytokine release. The lack of PKC activation seems to be dependent on the reduced expression of the receptor for activated C kinase 1 (RACK1), a scaffolding protein involved in multiple signal transduction cascades. The defective expression of RACK1 may be dependent on age-related alteration of the balance between the adrenal hormones cortisol and dehydroepiandrosterone (DHEA). DHEA levels reduce with aging, while cortisol levels remain substantially unchanged, resulting in an overall increase in the cortisol:DHEA ratio. These hormonal changes are significant in the context of RACK1 expression and signaling function because DHEA administration in vivo and in vitro can restore the levels of RACK1 and the function of the PKC signaling cascade in aged animals and in human cells. In contrast, there is evidence that cortisol can act as a negative transcriptional regulator of RACK1 expression. The rack1 gene promoter contains a glucocorticoid responsive element that is also involved in androgen signaling. Furthermore DHEA may have an indirect influence on the post-transcriptional regulation of the functions of the glucocorticoid receptor. In this review, we will examine the role of the hormonal regulation of rack1 gene transcriptional regulation and the consequences on signaling and function in immune cells and immunosenescence

Nature-Inspired Multifunctional Ligands: Focusing on Amyloid-Based Molecular Mechanisms of Alzheimer's Disease.

The amyloidogenic pathway is a prominent feature of Alzheimer's disease (AD). However, growing evidence suggests that a linear disease model based on β-amyloid peptide (Aβ) alone is not likely to be realistic, which therefore calls for further investigations on the other actors involved in the play. The pro-oxidant environment induced by Aβ in AD pathology is well established, and a correlation among Aβ, oxidative stress, and conformational changes in p53 has been suggested. In this study, we applied a multifunctional approach to identify allyl thioesters of variously substituted trans-cinnamic acids for which the pharmacological profile was strategically tuned by hydroxy substituents on the aromatic moiety. Indeed, only catechol derivative 3 [(S)-allyl (E)-3-(3,4-dihydroxyphenyl)prop-2-enethioate] inhibited Aβ fibrilization. Conversely, albeit to different extents, all compounds were able to decrease the formation of reactive oxygen species in SH-SY5Y neuroblastoma cells and to prevent alterations in the conformation of p53 and its activity mediated by soluble sub-lethal concentrations of Aβ. This may support an involvement of oxidative stress in Aβ function, with p53 emerging as a potential mediator of their functional interplay

Differences in views of schizophrenia during medical education: a comparative study of 1st versus 5th–6th year Italian medical students

Purpose This study explored medical students’ causal explanations and views of schizophrenia, and whether they changed during medical education. Method The survey was carried out on medical students of the Second University of Naples, Italy, who attended their first-year and their fifth- or sixth-year of lessons. The 381 who accepted were asked to read a case-vignette describing a person who met the ICD-10 criteria for schizophrenia and then fill in the Opinions on mental illness Questionnaire. Results The most frequently cited causes were psychological traumas (60 %) and stress (56 %), followed by misuse of street drugs (47 %), and heredity (42 %). 28 % of students stated that persons with the disorder could be well again, and 28 % that they were unpredictable. Labeling the case as “schizophrenia” and naming heredity among the causes were associated with pessimism about recovery and higher perception of social distance. First-year students more frequently reported psychological traumas among the causes (76 vs. 45 %), and less frequently heredity (35 vs. 81 %) and stress (42 vs. 69 %), and they perceived less social distance from the “schizophrenics” than fifth/sixth-year students. In particular, 18 % percent of first-year versus 38 % of fifth/sixth-year students believed that these persons were kept at a distance by the other, and 45 versus 57 % felt frightened by persons with the condition. Conclusions These results indicate a need to include education on stigma and recovery in schizophrenia in the training of medical students