The relationship between depressive symptoms, diabetes symptoms, and self-management among an urban, low-income Latino population.

Objective: To investigate the prevalence of depression symptoms among Latinos with diabetes following transition from hospital to home and the relationship of depressive symptoms to diabetes symptom severity and self-management activities.

Methods: 203 Latino patients with diagnosed diabetes completed a survey assessing depressive symptoms (PHQ-9), diabetes symptom severity, and diabetes self-management activities (SDSCA). Characteristics and diabetes outcomes between patients with and without probable major depression were compared.

Atomic models of de novo designed cc beta-Met amyloid-like fibrils.

The common characteristics of amyloid and amyloid-like fibrils from disease- and non-disease-associated proteins offer the prospect that well-defined model systems can be used to systematically dissect the driving forces of amyloid formation. We recently reported the de novo designed cc beta peptide model system that forms a native-like coiled-coil structure at low temperatures and which can be switched to amyloid-like fibrils by increasing the temperature. Here, we report a detailed molecular description of the system in its fibrillar state by characterizing the cc beta-Met variant using several microscopic techniques, circular dichroism spectroscopy, X-ray fiber diffraction, solid-state nuclear magnetic resonance, and molecular dynamics calculations.

Time-lapse atomic force microscopy in the characterization of amyloid-like fibril assembly and oligomeric intermediates.

The atomic force microscope (AFM) images the topography of biological structures adsorbed to surfaces with nanometer to angstrom scale resolution. Amyloid-like fibrils and oligomers can be imaged in buffer solutions, allowing the samples to retain physiological-like properties while temporal changes in structure are monitored, e.g.

Exploring amyloid formation by a de novo design.

Protein deposition as amyloid fibrils underlies many debilitating human disorders. The complexity and size of disease-related polypeptides, however, often hinders a detailed rational approach to study effects that contribute to the process of amyloid formation. We report here a simplified peptide sequence successfully designed de novo to fold into a coiled-coil conformation under ambient conditions but to transform into amyloid fibrils at elevated temperatures.

Human amylin oligomer growth and fibril elongation define two distinct phases in amyloid formation.

Human amylin (hA), a 37-amino-acid polypeptide, is one of a number of peptides with the ability to form amyloid fibrils and cause disease. It is the main constituent of the pancreatic amyloid deposits associated with type 2 diabetes. Increasing interest in early assembly intermediates rather than the mature fibrils as the cytotoxic agent has led to this study in which the smallest hA oligomers have been captured by atomic force microscopy.

Hepatocyte nuclear factor 1 negatively regulates amylin gene expression.

Maturity-onset diabetes of the young (MODY) is a monogenic subtype of Type 2 diabetes, defined as having an early age of onset, with a dominant inheritance pattern. Hepatocyte nuclear factor 1 (HNF1), which is encoded by the MODY3 gene, has been shown to bind the insulin promoter. Since the promoters of three pancreas-specific genes involved in glucose homeostasis-insulin, glucokinase, and amylin bind similar transcription factors, we were interested in whether HNF1 could also regulate amylin expression.

Full-length rat amylin forms fibrils following substitution of single residues from human amylin.

Pancreatic amyloid deposits, composed of the 37 amino acid residue peptide amylin, represent an integral part of type 2 diabetes mellitus pathology. Human amylin (hA) forms fibrils in vitro and is toxic to cultured pancreatic islet beta-cells. In contrast, rat amylin (rA) which differs from hA by only six amino acid residues in the central region of the peptide, residues 18-29, does not form fibrils and is not cytotoxic.