ABSTRACT
Glucocorticoids (GCs) are potent repressors of NF-κB activity, making them a preferred choice for treatment of inflammation-driven conditions. Despite the widespread use of GCs in the clinic, current models are inadequate to explain the role of the glucocorticoid receptor (GR) within this critical signaling pathway. GR binding directly to NF-κB itself-tethering in a DNA binding-independent manner-represents the standing model of how GCs inhibit NF-κB-driven transcription. We demonstrate that direct binding of GR to genomic NF-κB response elements (κBREs) mediates GR-driven repression of inflammatory gene expression. We report five crystal structures and solution NMR data of GR DBD-κBRE complexes, which reveal that GR recognizes a cryptic response element between the binding footprints of NF-κB subunits within κBREs. These cryptic sequences exhibit high sequence and functional conservation, suggesting that GR binding to κBREs is an evolutionarily conserved mechanism of controlling the inflammatory response.
Subject(s)
NF-kappa B/genetics , NF-kappa B/metabolism , Receptors, Glucocorticoid/genetics , Receptors, Glucocorticoid/metabolism , Response Elements , Amino Acid Substitution , Animals , Binding Sites/genetics , Crystallography, X-Ray , HEK293 Cells , HeLa Cells , Humans , Models, Molecular , Mutagenesis, Site-Directed , NF-kappa B/chemistry , Nuclear Magnetic Resonance, Biomolecular , Receptors, Glucocorticoid/chemistry , Tumor Necrosis Factor-alpha/metabolismABSTRACT
South Africa's rise in noncommunicable diseases (NCDs) and health care provider shortages has generated the need for community health workers (CHWs) in rural areas. However, roles and interactions with clinic staff are not well understood. Interviews with health care workers at community clinics in Limpopo Province revealed common themes, including resource scarcity, clinic-patient partnerships, management of NCDs, and collaboration between professionals. The data did not support CHW-physician interactions, necessitating further research to describe these practices and to evaluate CHWs' impact on patient outcomes. The CHW involvement in rural clinics is essential to patient-clinic partnerships and may help close treatment gaps in resource-poor areas.
Subject(s)
Community Health Workers/organization & administration , Noncommunicable Diseases/therapy , Rural Health Services/organization & administration , Humans , Pilot Projects , Rural Health , South AfricaABSTRACT
Bifunctional DNA oligonucleotides serve as templates for chromophoric silver clusters and as recognition sites for target DNA strands, and communication between these two components is the basis of an oligonucleotide sensor. Few-atom silver clusters exhibit distinct electronic spectra spanning the visible and near-infrared region, and they are selectively synthesized by varying the base sequence of the DNA template. In these studies, a 16-base cluster template is adjoined with a 12-base sequence complementary to the target analyte, and hybridization induces structural changes in the composite sensor that direct the conversion between two spectrally and stoichiometrically distinct clusters. Without its complement, the sensor strand selectively harbors ~7 Ag atoms that absorb at 400 nm and fold the DNA host. Upon association of the target with its recognition site, the sensor strand opens to expose the cluster template that has the binding site for ~11 Ag atoms, and absorption at 720 nm with relatively strong emission develops in lieu of the violet absorption. Variations in the length and composition of the recognition site and the cluster template indicate that these types of dual-component sensors provide a general platform for near-infrared-based detection of oligonucleotides in challenging biological environments.
