Modulation of Glucagon-like Peptide-1 (GLP-1) Potency by Endocannabinoid-like Lipids Represents a Novel Mode of Regulating GLP-1 Receptor Signaling.

Glucagon-like peptide-1 (GLP-1) analogs are approved for treatment of type 2 diabetes and are in clinical trials for disorders including neurodegenerative diseases. GLP-1 receptor (GLP-1R) is expressed in many peripheral and neuronal tissues and is activated by circulating GLP-1. Other than food intake, little is known about factors regulating GLP-1 secretion. Given a normally basal circulating level of GLP-1, knowledge of mechanisms regulating GLP-1R signaling, which has diverse functions in extrapancreatic tissues, remains elusive. In this study, we found that the potency of GLP-1, not exendin 4, is specifically enhanced by the endocannabinoid-like lipids oleoylethanolamide (OEA) and 2-oleoylglycerol but not by stearoylethanolamide (SEA) or palmitoylethanolamide. 9.2 µM OEA enhances the potency of GLP-1 in stimulating cAMP production by 10-fold but does not affect its receptor binding affinity. OEA and 2-oleoylglycerol, but not SEA, bind to GLP-1 in a dose-dependent and saturable manner. OEA but not SEA promoted GLP-1(7-36) amide to trypsin inactivation in a dose-dependent and saturable manner. Susceptibility of GLP-1(7-36) amide to trypsin inactivation is increased 40-fold upon binding to OEA but not to SEA. Our findings indicate that OEA binds to GLP-1(7-36) amide and enhances the potency that may result from a conformational change of the peptide. In conclusion, modulating potency of GLP-1 by physiologically regulated endocannabinoid-like lipids allows GLP-1R signaling to be regulated spatiotemporally at a constant basal GLP-1 level.

Annexin II binds to capsid protein VP1 of enterovirus 71 and enhances viral infectivity.

Enterovirus type 71 (EV71) causes hand, foot, and mouth disease (HFMD), which is mostly self-limited but may be complicated with a severe to fatal neurological syndrome in some children. Understanding the molecular basis of virus-host interactions might help clarify the largely unknown neuropathogenic mechanisms of EV71. In this study, we showed that human annexin II (Anx2) protein could bind to the EV71 virion via the capsid protein VP1. Either pretreatment of EV71 with soluble recombinant Anx2 or pretreatment of host cells with an anti-Anx2 antibody could result in reduced viral attachment to the cell surface and a reduction of the subsequent virus yield in vitro. HepG2 cells, which do not express Anx2, remained permissive to EV71 infection, though the virus yield was lower than that for a cognate lineage expressing Anx2. Stable transfection of plasmids expressing Anx2 protein into HepG2 cells (HepG2-Anx2 cells) could enhance EV71 infectivity, with an increased virus yield, especially at a low infective dose, and the enhanced infectivity could be reversed by pretreating HepG2-Anx2 cells with an anti-Anx2 antibody. The Anx2-interacting domain was mapped by yeast two-hybrid analysis to VP1 amino acids 40 to 100, a region different from the known receptor binding domain on the surface of the picornavirus virion. Our data suggest that binding of EV71 to Anx2 on the cell surface can enhance viral entry and infectivity, especially at a low infective dose.

Assessment of GPs' beliefs relating to the care of people with intellectual disabilities: a Taiwan-based, opportunity-guided approach.

PURPOSE: This study was designed to investigate general practitioners' (GPs) beliefs about the perceived importance of their role in, and their satisfaction with, providing healthcare to people with intellectual disabilities. The identification of healthcare issues with potential for improvement was assessed using gap analysis and an opportunity-guided method. METHOD: A cross-sectional census survey by a mail-structured questionnaire recruited 331 GPs (response rate--16%) who provided information on healthcare for people with intellectual disabilities in 2006 in Taiwan. RESULTS: The results indicated that GPs considered their role in providing healthcare for people with intellectual disabilities to be important (mean score 7.2-8.3). However, the respondents generally did not feel satisfied (mean score 4.6-5.5) with their achievements in treating patients with intellectual disabilities. We found that the gender and educational level of the respondents were statistically correlated to the perceived importance they considered their work to have, while the factors of age, medical practice setting and training experience in intellectual disability were statistically correlated to GPs' perceived satisfaction in providing healthcare to people with intellectual disabilities (p < 0.05). Those healthcare issues of'training and experience in intellectual disability', 'multi-disciplinary and multi-sectoral cooperation', 'adequate competence in disability diagnosis', 'genetic consulting services', 'duty of disease prevention and health promotion', and 'adequate medical consultation time' were the five most promising areas to be improved in healthcare for people with intellectual disabilities according to the opportunity-guided analysis. CONCLUSIONS: This study highlights that health professionals need to examine carefully healthcare issues pertaining to people with ID, and that much more effort is required to develop appropriate healthcare policies based on the opportunity-guided health issues identified here.