Bariatric endoscopy: from managing complications to primary metabolic procedures

Obesity is a worldwide epidemic and is the second leading cause of preventable death. The approach to treating obesity involves a multidisciplinary approach including lifestyle interventions, pharmacological therapies, and bariatric surgery. Endoscopic interventions are emerging as important tools in the treatment of obesity with primary and revisional bariatric endoscopic therapies. These include intragastric balloons, aspiration therapy, suturing and plication, duodenal-jejunal bypass liners, endoscopic duodenal mucosal resurfacing, and incisionless magnetic anastomosis systems.  Endoscopic interventions have also demonstrated efficacy in treating complications of bariatric surgery. Approaches include stenting, endoscopic internal drainage, and endoscopic vacuum-assisted closure. This review aimed to discuss the current endoscopic procedures used as primary and revisional bariatric therapy including those used for managing bariatric surgical complications.

Protein kinase A-dependent phosphorylation of B/K protein

We have previously isolated a novel protein "B/K" that contains two C2-like domains. Here, we report the isolatioin and mRNA distribution of a human B/K isoform, and protein kinase A (PKA)-dependent phosphorylation of the B/K protein. The 1.5 kb human B/K cDNA clone exhibits 89% and 97% identities with rat B/K in the sequences of nucleotide and amino acid, respectively. Human B/K isoform encodes a 474 amino acid protein and shows structural features similar to the rat counterpart including two C2 domains, three consensus sequences for PKA, absence of a transmembrane region, and conservation of the N-terminal cysteine cluster. On Northern and dot blot analyses, a 3.0 kb B/K transcript was abundantly present in human brain, kidney, and prostate. Among the brain regions, strong signals were observed in the frontal and temporal lobes, the hippocampus, the hypothalamus, the amygdala, the substantia nigra, and the pituitary. Recombinant B/K proteins containing three consensus sites for PKA was very efficiently phosphorylated in vitro by PKA catalytic subunit. B/K protein which was overexpressed in LLC-PK1 cells was also strongly phosphorylated in vivo by vasopressin analog DDAVP, and PKA-specific inhibitor H89 as well as type 2 vasopressin receptor antagonist specifically suppressed DDAVP-induced B/K phosphorylation. These results suggest that B/K proteins play a role as potential substrates for PKA in the area where they are expressed.