Written informed consent were obtained from both parents within PROG/09/18 and written informed consent was independently obtained from the healthy volunteer sampled for inner cheek mechanically exfoliated epithelial cells. Concerning studies on rat pups, animal experiments were realized according to the rules of the Nantes animal experimental unit and the Principles of laboratory animal care . The protocol was strictly non-invasive for rat pups and mothers and as such was approved under the number P-2010-01 by the local review board of UMR-1280 animal husbandry . Animals were euthanized by carbon dioxide exposure. Fluid aspirates of preterm infants or gastric 133407-82-6 contents of rat pups were stored at 270uC and processed within one month of sampling using identical procedure and buffers to recover exfoliated epithelial cells. The procedure to obtain gastric fluid aspirates is standard in our neonatalogy unit. Preterm infants equipped with a nasogastric tube are fed over 3-hour periods, using, for instance 30 mL of milk slowly instilled by a syringe pump device into the stomach lumen. At the end of each 3-hour period, the nursing staff disconnects the device and collects empties the infant��s gastric residues by manual aspiration using a sterile syringe connected to the nasogastric tube. Undigested milk and gastric fluids are then removed by a slow depression of the syringe. The gastric fluid aspirate is transferred into sterile plastic tubes for immediate processing or direct storage at 270uC. Briefly, gastric samples were thawed and diluted out in 15 ml EDTA/DTT buffer ). The H+/K+ ATPase, or gastric pump, share structural similarities like an alpha and beta subunit, with the ubiquitous Na+/K+ ATPase. The monoclonal antibody that we used is specific for the beta-subunit which may play a role in maintaining the structural and functional integrity of the complex. To our knowledge, expression of H+/K+ ATPase has never been reported to occur in exfoliated epithelial cells from the mammary gland. Survivin, a member of the inhibitors-of-apoptosis protein family, has been BYL719 PI3K inhibitor described as expressed in gastric parietal cells of adult rats and humans . In situ detection of microtubule-associated protein light chain 3b by primary antibodies has been recommended when this protein constitutive of the autophagosome is overexpressed during progressive autophagy . However, autophagy has been demonstrated to occur in vivo in the surface epithelial cells of neonatal small intestine of piglets .