Our prior studies have shown that B type Natriuretic Peptide (BNP) decreases absorption from the gastrointestinal (GI) tract. Since non-muscle myosin-type II (NMM-II) is known to have a role in epithelial tight junction regulation, we aimed to test whether BNP has an effect on the localization and expression of NMM-II in the intestinal villi. We treated wild type mice with a 10 ng/g intravenous bolus of BNP followed by infusion of BNP at 1ng/g/minute vs. vehicle control. The mice were then euthanized and intestinal tissue isolated and sectioned. The tissue was immune-stained for NMM-II and examined using fluorescence microscopy. The tissue section not treated with antibody to NMM-II was used as a methodological control to evaluate the non-specific binding. Scanning electron micrographic images were taken to compare structural differences between the two groups. Western blotting was performed to compare the regional protein expression of NMM-II and associated proteins including smooth muscle actin, kinesin, and E cadherin in small intestinal tissue between BNP vs. vehicle infused mice. Fluorescence microscopy revealed markedly increased localization of NMM-II at the crypts and core of intestinal villi of the jejunum, ileum and colon of BNP treated mice compared to vehicle. Transmission electron microscopy revealed that the microvilli of BNP treated mice assumed the distinctive appearance of ‘relaxed’ microvilli compared to vehicle. Such decrease in contractility was previously shown to decrease para-cellular permeability of epithelia. Our observation indicates that BNP alters the localization of NMM-II in intestinal villi and makes the intestinal villi structures assume a state of decreased permeability of the apical junctional complex. Further characterization of this process and understanding the specific mediators involved could lead to the identification of novel therapeutic targets for various disease states such as heart failure and malabsorption.

The lungs are among several organs that can be adversely affected by chronic alcohol consumption. We used a proteomic approach to identify changes in lung proteins in female C57Bl/6 mice chronically ingesting 20% EtOH for 6 weeks and in similarly maintained caloric control‐fed animals. Proteins from the lungs of EtOH‐and control‐mice were separated by 2‐D gel electrophoresis. Coomassie stained gels revealed many protein spots that shifted and densitometry showed these proteins either increased or decreased in abundance in response to EtOH exposure. Protein spots were excised from the gels, destained, and digested with trypsin before being identified by LC‐MS/MS. Chronic alcohol consumption affected the protein expression levels of a tight junction protein, kinases, and actin‐binding proteins. The differentially expressed protein spots were analyzed using the PDQuest software which revealed 31 unique protein spots in the control group, 49 unique protein spots in the EtOH group, and 54 unique protein spots that overlapped between the two groups. Western blot analysis was used to confirm proteins up or down regulation by chronic EtOH exposure. Chronic alcohol consumption and alcohol metabolism are linked to tissue damage and various diseases. Herein, we identified specific proteins that may be involved in the etiology of these diseases. Funding from NIH R00HL09226 awarded to MNH and NIH NRSA awarded to AAA.