Absence of the Peptide Transporter 1 Induces a Prediabetic and Depressive-Like Phenotype in Mice.

INTRODUCTION: Protein-enriched diets improve glycemic control in diabetes or emotional behavior in depressive patients. In mice, these benefits depend on intestinal gluconeogenesis activation by di-/tripeptides. Intestinal di-/tripeptides absorption is carried out by the peptide transporter 1, PEPT1. The lack of PEPT1 might thus alter glucose and emotional balance. METHODS: To determine the effects of PEPT1 deficiency under standard dietary conditions or during a dietary challenge known to promote both metabolic and cognitive dysfunction, insulin sensitivity, anxiety, and depressive-like traits, hippocampal serotonin (5-HT) and insulin signaling pathway were measured in wild-type (WT) and Pept1-/- mice fed either a chow or a high-fat high-sucrose (HF-HS) diet. RESULTS: Pept1-/- mice exhibited slight defects in insulin sensitivity and emotional behavior, which were aggravated by an HF-HS diet. Pept1-/- mice fed a chow diet had lower hippocampal 5-HT levels and exhibited cerebral insulin resistance under HF-HS diet. These defects were independent of intestinal gluconeogenesis but might be linked to increased plasma amino acids levels. CONCLUSION: Pept1-/- mice develop prediabetic and depressive-like traits and could thus be used to develop strategies to prevent or cure both diseases.

Cerebral amyloid angiopathy with focal presentation-about 3 cases.

Cerebral amyloid angiopathy (CAA) is a common cerebrovascular disease involved in ischemic and hemorrhagic strokes, and its progression is correlated to cognitive decline. In vivo diagnosis of CAA is guided by the modified Boston criteria, with the presence of multiple intracerebral hemorrhage or cerebral microbleeds (CMB), or single hemorrhage and cortical superficial siderosis. The diagnosis of CAA is highly dependent on the quality of imaging and the advent of susceptibility-weighted imaging (SWI) sequences has improved sensitivity of MRI to detect hemosiderin deposition and CMB, hallmarks of CAA. We report here 3 clinical cases of patients with Alzheimer's disease and a focal form (i.e., not disseminated) of probable CAA, diagnosed with SWI sequences. Focal CAA may require closer attention and could offer keys in the understanding of both Alzheimer's disease and CAA pathogenesis.