Effect of Orally Administered Prostaglandin E2 and its 15-Methyl Analogues on Gastric Secretion

The effect of orally administered prostaglandin E₂ and its synthetic 15-methyl analogues on gastric secretion in man was studied. The parent E₂ compound did not inhibit basal secretion, whereas both the 15 (S) 15-methyl-E₂ methyl ester and its isomer, 15 (R) 15-methyl-E₂ methyl ester inhibited basal acid secretion. This action is likely to be a direct one on the parietal cell, and it could prove of value in the treatment of peptic ulcer.     

Detection of Pleiotropy through a Phenome-Wide Association Study (PheWAS) of Epidemiologic Data as Part of the Environmental Architecture for Genes Linked to Environment (EAGLE) Study

We performed a Phenome-wide association study (PheWAS) utilizing diverse genotypic and phenotypic data existing across multiple populations in the National Health and Nutrition Examination Surveys (NHANES), conducted by the Centers for Disease Control and Prevention (CDC), and accessed by the Epidemiological Architecture for Genes Linked to Environment (EAGLE) study. We calculated comprehensive tests of association in Genetic NHANES using 80 SNPs and 1,008 phenotypes (grouped into 184 phenotype classes), stratified by race-ethnicity. Genetic NHANES includes three surveys (NHANES III, 1999–2000, and 2001–2002) and three race-ethnicities: non-Hispanic whites (n = 6,634), non-Hispanic blacks (n = 3,458), and Mexican Americans (n = 3,950). We identified 69 PheWAS associations replicating across surveys for the same SNP, phenotype-class, direction of effect, and race-ethnicity at p<0.01, allele frequency >0.01, and sample size >200. Of these 69 PheWAS associations, 39 replicated previously reported SNP-phenotype associations, 9 were related to previously reported associations, and 21 were novel associations. Fourteen results had the same direction of effect across more than one race-ethnicity: one result was novel, 11 replicated previously reported associations, and two were related to previously reported results. Thirteen SNPs showed evidence of pleiotropy. We further explored results with gene-based biological networks, contrasting the direction of effect for pleiotropic associations across phenotypes. One PheWAS result was ABCG2 missense SNP rs2231142, associated with uric acid levels in both non-Hispanic whites and Mexican Americans, protoporphyrin levels in non-Hispanic whites and Mexican Americans, and blood pressure levels in Mexican Americans. Another example was SNP rs1800588 near LIPC, significantly associated with the novel phenotypes of folate levels (Mexican Americans), vitamin E levels (non-Hispanic whites) and triglyceride levels (non-Hispanic whites), and replication for cholesterol levels. The results of this PheWAS show the utility of this approach for exposing more of the complex genetic architecture underlying multiple traits, through generating novel hypotheses for future research.     

Conformational change of human lens insoluble α-crystallin

Human lens α-crystallin becomes progressively insoluble with age and is the major crystallin component in the water-insoluble (WI) fraction. The mechanism that causes the originally water-soluble (WS) α-crystallin to become insoluble is unknown. A conformational change by chemical modification may be the cause, but the nature of insolubility renders it impossible to study protein conformation in the WI fraction by most spectroscopic measurements. In the present study, α-crystallin in the WI fraction was extracted by urea and reconstituted to a folded protein by dialysis. The refolded urea-soluble (US) α-crystallin was compared with WS α-crystallin. The US α-crystallin has a greater amount of polymeric species, but fewer degraded subunits than the WS α-crystallin as shown by SDS-PAGE and Western blot. Circular dichroism (CD) measurements indicate that they have the same secondary structure but a different tertiary structure, possibly a partial unfolding in the US α-crystallin. This is supported by fluorescence measurements: Trp residues are more exposed and protein has a more-hydrophobic surface in the US than in the WS α-crystallin. Blue fluorescence further indicates that the US α-crystallin has a greater amount of pigment than the WS α-crystallin. Together, these results indicate that the US α-crystallin is a chemically and conformationally modified protein.     

RNA pull-down confocal nanoscanning (RP-CONA) detects quercetin as pri-miR-7/HuR interaction inhibitor that decreases α-synuclein levels

RNA–protein interactions are central to all gene expression processes and contribute to a variety of human diseases. Therapeutic approaches targeting RNA–protein interactions have shown promising effects on some diseases that are previously regarded as ‘incurable’. Here, we developed a fluorescent on-bead screening platform, RNA Pull-Down COnfocal NAnoscanning (RP-CONA), to identify RNA–protein interaction modulators in eukaryotic cell extracts. Using RP-CONA, we identified small molecules that disrupt the interaction between HuR, an inhibitor of brain-enriched miR-7 biogenesis, and the conserved terminal loop of pri-miR-7–1. Importantly, miR-7′s primary target is an mRNA of α-synuclein, which contributes to the aetiology of Parkinson’s disease. Our method identified a natural product quercetin as a molecule able to upregulate cellular miR-7 levels and downregulate the expression of α-synuclein. This opens up new therapeutic avenues towards treatment of Parkinson’s disease as well as provides a novel methodology to search for modulators of RNA–protein interaction.