Affinity-Driven Aryl Diazonium Labeling of Peptide Receptors on Living Cells.

Peptide-receptor interactions play critical roles in a wide variety of physiological processes. Methods to link bioactive peptides covalently to unmodified receptors on the surfaces of living cells are valuable for studying receptor signaling, dynamics, and trafficking and for identifying novel peptide-receptor interactions. Here, we utilize peptide analogues bearing deactivated aryl diazonium groups for the affinity-driven labeling of unmodified receptors. We demonstrate that aryl diazonium-bearing peptide analogues can covalently label receptors on the surface of living cells using both the neurotensin and the glucagon-like peptide 1 receptor systems. Receptor labeling occurs in the complex environment of the cell surface in a sequence-specific manner. We further demonstrate the utility of this covalent labeling approach for the visualization of peptide receptors by confocal fluorescence microscopy and for the enrichment and identification of labeled receptors by mass spectrometry-based proteomics. Aryl diazonium-based affinity-driven receptor labeling is attractive due to the high abundance of tyrosine and histidine residues susceptible to azo coupling in the peptide binding sites of receptors, the ease of incorporation of aryl diazonium groups into peptides, and the relatively small size of the aryl diazonium group. This approach should prove to be a powerful and relatively general method to study peptide-receptor interactions in cellular contexts.

Meta-Analytic Findings on Reading in Children With Cochlear Implants.

This meta-analysis study aims to quantify the group differences in reading skills between children with cochlear implants and their hearing peers and between children with cochlear implants and children with hearing aids (aged between 3 and 18 years old). Of the 5,642 articles screened, 47 articles met predetermined inclusion criteria (published between 2002 and 2019). The robust variance estimation based meta-analysis models were used to synthesize all the effect sizes. Children with cochlear implants scored significantly lower than their hearing peers in phonological awareness (g = -1.62, p < 0.001), vocabulary (g = -1.50, p < 0.001), decoding (g = -1.24, p < 0.001), and reading comprehension (g = -1.39, p < 0.001), but not for fluency (g = -0.67, p = 0.054). Compared to children with hearing aids, children with cochlear implants scored significantly lower in phonological awareness (g = -0.30, p = 0.028). The percentage of unilateral cochlear implant negatively impacts the group difference between children with cochlear implants and their hearing peers. Findings from this study confirm a positive shift in reading outcomes for profoundly deaf children due to cochlear implantation. Some children with cochlear implants may need additional supports in educational settings.