Using a yeast two-hybrid system, we identified a novel protein which interacts with ras p21. This protein shares 69%6 amino acid homology with ral guanine nucleotide dissociation stimulator (ralGDS), a GDP/GTP exchange protein for ral p24. We designated this protein RGL, for ralGDS-like. Using the yeast two-hybrid system, we found that an effector loop mutant ofras p21 was defective in interacting with the ras p21-interacting domain of RGL, suggesting that this domain binds to ras p21 through the effector loop ofras p21. Since (2,17,24,32). ras p21 has GDP/GTP-binding and GTPase activities and cycles between the GDP-bound inactive and GTP-bound active forms. The GDP-bound inactive form can be activated by guanine nucleotide exchange proteins (24, 32) which promote the exchange of GDP for GTP, thereby converting ras p21 to the GTP-bound active form. Presumably the GTP-bound active form of ras p21 interacts with effector proteins that can mediate ras p21-dependent processes such as growth factor-stimulated cell proliferation.Identification of effector proteins of the active form of ras p21 has been difficult. One candidate effector protein of ras p21 is Raf, a cytoplasmic serine/threonine protein kinase that has been previously shown to act downstream of ras p21 (8,15,21). It has been recently demonstrated that Raf interacts with the GTP-bound but not with the GDP-bound form of ras p21 (18,20,29,(33)(34)(35)41), that Raf binds to the effector loop of ras p21 (20,(33)(34)(35)41), and that Raf inhibits the GTPase-activating activity of GTPase-activating protein (GAP), which is known to interact with the effector loop of ras p21 (35, 41). These results have indicated that Raf is an effector protein of ras p21, consistent with previous observations that Raf acts downstream of ras p21 in signaling pathways that mediate both the differentiation and mitogenic responses to receptor tyrosine kinases (8,15,17,21,24,30,36 (33,34,41), and that Bcl-2 binds to R-ras p23 (11). We report here the identification of a novel protein that interacts with ras p21 in the yeast two-hybrid system. Thi' p"rotpin, termed RGL (ralGDS-like), is highly homologous with rat' guanine nucleotide dissociation stimulator (ralGDS), a GDP/GTP exchange protein for ral p24, a member of small G-protein superfamily (1). Our results indicate that the ras p21-binding domain of RGL binds to ras p21 through the effector loop of ras p21 and that this domain is highly conserved in ralGDS. These results prompted us to examine whether this new family of proteins (RGL and ralGDS) could be effector proteins of ras p21. Since ralGDS has been well characterized (1), we used ralGDS to examine this possibility. We tested three characteristics that could be considered to be criteria for identification of an effector protein of ras p21: (i) the protein must interact with the GTP-bound active form of ras p21 but not with the GDPbound inactive form, (ii) it must interact with ras p21 through the effector loop of ras p21, and (iii) ideally the protein should inhibit the ...

We conducted a systematic review and meta-analysis to investigate whether the use of statins could be associated with the risk of all-caused dementia, Alzheimer’s disease (AD), vascular dementia (VaD), and mild cognitive impairment (MCI). Major electronic databases were searched until December 27th, 2017 for studies investigating use of statins and incident cognitive decline in adults. Random-effects meta-analyses calculating relative risks (RRs) were conducted to synthesize effect sizes of individual studies. Twenty-five studies met eligibility criteria. Use of statins was significantly associated with a reduced risk of all-caused dementia (k = 16 studies, adjusted RR (aRR) = 0.849, 95% CI = 0.787–0.916, p = 0.000), AD (k = 14, aRR = 0.719, 95% CI = 0.576–0.899, p = 0.004), and MCI (k = 6, aRR = 0.737, 95% CI = 0.556–0.976, p = 0.033), but no meaningful effects on incident VaD (k = 3, aRR = 1.012, 95% CI = 0.620–1.652, p = 0.961). Subgroup analysis suggested that hydrophilic statins were associated with reduced risk of all-caused dementia (aRR = 0.877; CI = 0.818–0.940; p = 0.000) and possibly lower AD risk (aRR = 0.619; CI = 0.383–1.000; p = 0.050). Lipophilic statins were associated with reduced risk of AD (aRR = 0.639; CI = 0.449–0.908; p = 0.013) but not all-caused dementia (aRR = 0.738; CI = 0.475–1.146; p = 0.176). In conclusion, our meta-analysis suggests that the use of statins may reduce the risk of all-type dementia, AD, and MCI, but not of incident VaD.

The CellKey (MDS Sciex, South San Francisco, CA) system enables comprehensive pharmacological evaluation of cell surface receptors, including G-protein coupled receptors (GPCRs) and tyrosine kinase receptors, using adherent and suspension cell lines and primary cells. A unique application enabled by the ability of the CellKey system to reliably quantify activation of endogenous receptors is receptor panning. This application allows investigators to easily screen disease-relevant cell types for functionally active target receptors by treating cells with a panel of receptor-specific ligands. Receptor panning of multiple cell types including Chinese hamster ovary, human embryonic kidney 293, HeLa, U-937, U-2 OS, and TE671 cells resulted in the identification of many functionally active, differently coupled endogenous GPCRs, some of which have not been previously documented in the literature. Upon detecting GPCR activation in live cells, unique cellular dielectric spectroscopy (CDS) response profiles are generated within minutes that reflect the signaling pathways utilized and have been shown to be characteristic of Gs, Gq, and Gi GPCRs. The fact that the CDS response profiles are predictive of the G-protein coupling mechanism of the receptor was demonstrated by using examples of subtype-selective agonists/antagonists to identify the subtypes of the endogenous histamine and beta-adrenergic receptors expressed in U-2 OS cells. A direct correlation is shown between receptor subtype G-protein coupling and CDS response profile. In addition, complex pharmacology, including detection of partial agonism and Schild analysis for endogenous receptors, is presented. The CellKey system allows investigators to conduct studies using endogenously expressed receptors to generate data that are physiologically relevant and in disease context.

IMPORTANCE Although several pharmacological interventions for delirium have been investigated, their overall benefit and safety remain unclear. OBJECTIVE To evaluate evidence regarding pharmacological interventions for delirium treatment and prevention.

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This meta-analysis provides evidence that breastfeeding (exclusively or including additional supplements) may protect against ASD. Prospective longitudinal research is required to disentangle the complex relationships and to explore potential pathophysiological mechanisms.

Key Points Question Is omega-3 polyunsaturated fatty acid treatment associated with an improvement in anxiety symptoms? Findings In this systematic review and meta-analysis of 19 clinical trials including 2240 participants from 11 countries, improvement in anxiety symptoms was associated with omega-3 polyunsaturated fatty acid treatment compared with controls in both placebo-controlled and non–placebo-controlled trials. The anxiolytic effects of omega-3 polyunsaturated fatty acids were also stronger in participants with clinical conditions than in subclinical populations. Meaning Omega-3 polyunsaturated fatty acid treatment for anxiety might be effective in clinical settings.

We report the identification of a novel class of phosphatidylinositol (PtdIns) 3-kinases whose members contain C-terminal C2 domains. We have isolated Drosophila and murine genes (termed cpk and cpk-m respectively) by polymerase chain reaction amplification of cDNA libraries with degenerate primers corresponding to conserved regions of PtdIns kinases. The amino acid sequences of Cpk and Cpk-m are most similar to that of p110, a family of PtdIns 3-kinases that mediates the responses of cells to mitogenic stimuli. The Cpk and Cpk-m sequences are similar to a large, central region of p110, but differ from p110 at their N and C termini. The N termini of the Cpk proteins do not contain any recognizable protein motif, while the C termini contain "C2 domains," a feature unique among PtdIns kinases. Cpk has an intrinsic PtdIns kinase activity and can phosphorylate PtdIns and PtdIns-4-P, but not PtdIns(4,5)P 2 , at the D3 position of the inositol ring. Cpk is the first PtdIns 3-kinase identified with this particular substrate specificity. We have identified two potential Cpk-binding proteins, p90 and p190, and have determined that both Cpk and p190 may be tyrosine phosphorylated. This finding suggests that Cpk function may be regulated by tyrosine kinases. PtdIns1 kinases regulate diverse cellular processes, which include cell signaling, cell cycle progression, and intracellular protein sorting (reviewed in Herman et al., 1992;Kapeller and Cantley, 1994;Stephens et al., 1993;Kunz et al., 1993). PtdIns kinases phosphorylate phosphoinositol lipids at distinct positions on the inositol ring; PtdIns 3-kinases phosphorylate the D3 hydroxyl group on the inositol ring, while PtdIns 4-kinases phosphorylate the D4 hydroxyl group (reviewed in Carpenter and Cantley (1990)). All PtdIns kinases contain a core region of sequence similarity, which is believed to be the catalytic domain. This domain, termed the "PtdIns kinase domain," shares limited sequence similarity with the catalytic domain of protein kinases (Hiles et al., 1992) and mutation of conserved residues results in loss of PtdIns kinase activity (Dhand et al., 1994;Schu et al., 1993). Surprisingly, the mechanism used by PtdIns kinases to modulate regulatory pathways remains unknown.A number of receptor tyrosine kinases, src-like tyrosine kinases and viral oncoproteins bind and activate a cellular PtdIns 3-kinase (reviewed in ). Studies of mutants that abrogate the binding of this PtdIns 3-kinase to these molecules suggest that PtdIns 3-kinases can mediate mitogenic and cell motility responses of cells to growth factors and oncoproteins. Purification of the polypeptide subunits of this PtdIns 3-kinase revealed that the enzyme exists as a heterodimeric complex composed of a 110-and an 85-kDa subunit Fry et al., 1992;Morgan et al., 1990;Shibasaki et al., 1991). The 110-kDa subunit contains a C-terminal PtdIns kinase domain, as well as a small domain at its N terminus that is sufficient for binding to the 85-kDa subunit (Holt et al., 1994;Hiles et al., 1992;Klippel et al., 199...