Neuropeptide Ys-Regulate Food Intake & Body Weight

Role of salivary PYY in the modulation of food intake.

This is a study that comprehensively shows the expression of Neuropeptide Ys  (PYY _3–36 ) are present in saliva and showed the expression of its preferred receptor, Y2R, in the basal layer of the progenitor cells of the tongue epithelia and von Ebner's gland. The researchers used our Y2R antibody (dilution 1:3000) to determine level of expression. This receptor appears to be the main player in mediating hunger and body weight: Hurtado MD, Acosta A, Riveros PP, Baum BJ, Ukhanov K, et al. (2012) Distribution of Y-Receptors in Murine Lingual Epithelia. PLoS ONE 7(9): e46358. doi:10.1371/journal.pone.0046358.

Images: Immunolocalization of Y1, Y2, Y4, and Y5 receptors (Rs) in the dorsal epithelium of murine tongue. Images: Mirror section pairs (Panels A and B, C and D, E and F) were hybridized to the respective YR antibody (green), followed by DAPI counterstain (blue), as indicated in the upper left corner of each panel. For better viewing, the confocal images in B, D, and F were reflected horizontally. Representative areas of the epithelium, positive for either YR (dashed rectangles in the left-sided panels), are shown as close-up images on the right next to each respective panel. The irregular columned structures at the epithelial surface are transversely sectioned filiform papillae. G - Y4R-positive neuronal fibers (green) are located in the subepithelial region underlying the basal laminae. H – co-localization of Y4R and NCAM (red) immunoreactivity within mechanoreceptors of Meissner corpuscles (MC). As a morpho-histological reference of the dorsal lingual epithelium structure, an hematoxylin and eosin stained section is shown in panel I. Panel J shows a hypothetical diagram of a lingual dorsal epithelium layer and the differentiation/migration lineage of cell types expressing respective YR subtypes. K5 – cytokeratin-5 [2]. doi:10.1371/journal.pone.0046358.g006.

Note: this study is further validation of the potency of our NPY Y2 antibody.

Conclusion: NPY family peptides and their cognate receptors in the oral cavity may mediate a wide variety of functions, including proliferation, differentiation, motility, taste perception, as well as satiation. All of these multiple functions and their respective molecular mechanisms are subjects of the ongoing investigations.

Understanding these molecular mechanisms could provide the foundation for discovering less intrusive therapies for obesity. I will keep you posted.

Salivary Neuropeptides Y2s and Satiety

A possible new slant for combating obesity

The researchers in this study acheived a sustained increased PYY_3-36 (a neuropeptide) expression via viral vector-mediated gene delivery targeting salivary glands and the good news: this increase resulted in a significant long-term reduction in food intake (FI) and body weight (BW). This is evidence for new functions of the previously characterized gut peptide PYY_3-36 suggesting a potential simple and efficient alternative therapeutic approach for the treatment of obesity: Andres Acosta1, Maria D. Hurtado1, Oleg Gorbatyuk, Michael La Sala, David Duncan, George Aslanidi, Martha Campbell-Thompson, Lei Zhang, Herbert Herzog, Antonis Voutetakis, Bruce J. Baum, Sergei Zolotukhin. Salivary PYY: A Putative Bypass to Satiety. PLoS ONE 6(10): e26137. doi:10.1371/journal.pone.0026137. Received: July 22, 2011; Accepted: September 20, 2011; Published: October 10, 2011...Rabbit anti-Y2R (Dilution: 1:3000) using TSA...

Images: A) Immunolocalization of Y2R-positive cells in the hippocampus of C57Bl/6J mouse (WT), a (+) control. (B) Immunolocalization of Y2R in the tongue epithelia of Y2R KO mouse, a (-) control. VEG – von Ebner's gland. (C) Immunolocalization of Y2R-positive cells in the CV area of the tongue of a C57Bl/6J mouse. (D) close-up of (C). (E), and (F) close ups of (D), top and bottom rectangles, respectively. doi:10.1371/journal.pone.0026137.g003

These findings could prove a first step in identifying new targets for obesity fighting therapies. Increasing PYY salivary output would provide satiety with less food intake. This would give a whole new perspective on dieting. If we are satsified with less food intake is this really dieting? Stay tuned.