Journal of Epithelial Biology & Pharmacology 

About: Journal of Epithelial Biology & Pharmacology is an academic journal. The journal publishes majorly in the area(s): Barrier function & Tight junction. Over the lifetime, 42 publications have been published receiving 425 citations.

Role of chitotriosidase (chitinase 1) under normal and disease conditions.

Abstract: Mammalian chitinases belong to the glycosyl hydrolase 18 family based on structural homology and the family includes a large number of bacterial and eukaryotic chitinases. Among the mammalian chitinases, chitotriosidase (CHIT1) and acidic mammalian chitinase (AMCase) are capable of hydrolyzing the β-(1, 4)-linkage between the adjacent N-acetyl glucosamine residues of chitin. CHIT1 is one of the most abundantly secreted proteins, being mainly produced by activated macrophages and epithelial cells. CHIT1 plays a pivotal role in the context of infectious disease including malaria and fungi infections as a host defense towards chitin in pathogen's cell structure and as a diagnostic marker of disease. In contrast, CHI1 released by activated Kupffer cells in liver could induce hepatic fibrosis and cirrhosis. Increased serum levels of CHIT1 were observed in patients with many disorders, including Gaucher's disease, bronchial asthma, and atherosclerosis. Therefore, CHIT1 seems to have dual (regulatory and pathogenic) roles depending on the disease and producing cell types during the inflammatory conditions.

Role of glutamine in protection of intestinal epithelial tight junctions

Abstract: Glutamine, a conditionally essential amino acid, is consumed predominantly in the gastrointestinal tract as a source of energy, particularly under the conditions of trauma, sepsis and surgery. In this article, we discuss the unique role of glutamine in the preservation of epithelial barrier function in the gastrointestinal tract. Glutamine supplementation protects the gastrointestinal mucosal homeostasis during total parenteral nutrition, diarrhea, radiation injury, starvation, sepsis and trauma. A significant body of evidence indicates that glutamine preserves the gut barrier function and prevents permeability to toxins and pathogens from the gut lumen into mucosal tissue and circulation. Recent studies demonstrated that the mucosal barrier protective effect of glutamine relates to its effect on preservation of epithelial tight junction integrity. The current understanding of glutamine-mediated protection of intestinal epithelial tight junction integrity and the potential mechanisms involved in this protective effect of glutamine are discussed.

Enhancement of Epithelial Barrier Function by Probiotics

Abstract: Probiotics are microbial organisms that are administered in supplements or foods to enhance the well-being of the host. There exists substantial evidence that in a strain and dose-dependent manner, probiotics can modulate systemic and mucosal immune function, improve intestinal barrier function, alter gut microecology, and exert metabolic effects on the host. Several strains of Lactobacillus and Bifidobacterium are able to compete with pathogens for binding to intestinal epithelial cells, and can displace pathogens. Epithelial cell signalling pathways are stimulated by whole microbes, structural components, and microbial-produced metabolites. In particular, the NF-kB pathway is modulated by probiotics at many different levels with effects seen on IB degradation and ubiquitination, proteasome function, and nuclear- cytoplasmic movement of RelA through a PPAR-gamma dependent pathway. In a strain and dose-dependent manner, probiotic strains have been shown to alter tight junction protein expression and/or localization in both in vivo and in vitro models. Probiotics can also enhance gut barrier function via increased production of cytoprotective molecules such as heat-shock proteins. In addition, probiotics are able to prevent cytokine- and oxidant-induced epithelial damage by promoting cell survival. Lactobacillus GG and soluble factors (p75 and p40) released from LGG prevented epithelial cell apoptosis through activating anti-apoptotic Akt in a phosphatidylinositol-3'-kinase (PI3K)-dependent manner and inhibiting pro-apoptotic p38/MAPK activation. It is clear that host-microbial interactions at the gut mucosal surface are critical for health and overall homeostasis and probiotics may possibly be harnessed to enhance barrier function in order to maintain health and protect against disease.

Drug Delivery to the Lung: Permeability and Physicochemical Characteristics of Drugs as the Basis for a Pulmonary Biopharmaceutical ClassificationSystem (pBCS)

Abstract: The respiratory tract is currently considered as an alternative to gastrointestinal and dermal drug delivery sys- tems and is used to deliver drugs for respiratory diseases as well as the treatment of non-pulmonary disorders. The first step in drug profiling for delivery via the respiratory tract needs to address intrinsic physicochemical parameters and their impact on or correlation with absorption. Moreover, the more the pulmonary drug delivery shall find acceptance, the greater will be the need for validated test systems, methods, and guidelines for regulatory purposes. The Biopharmaceuti- cal Classification System (BCS) remains the simplest and most common guiding principle for predicting drug absorption, but it is limited to the gastrointestinal tract. This review suggests an extension, the pulmonary Biopharmaceutical Classi- fication System (pBCS), that will take into consideration the specific biology of the lung as well as particle deposition, aerosol physics, and the subsequent processes of drug absorption and solubility. We will describe the steps to be taken to develop a pBCS as well as the compounds that will be used to establish this classification. Furthermore, we will introduce two cellular models with which drug permeability across the pulmonary barrier will be determined as an alternative to the currently and widely used studies with animals.

Tear Film and Ocular Surface Surfactants

Abstract: The hydrophobic surfactant proteins B (SP-B) and C (SP-C) are tightly bound to phospholipids. These proteins play important roles in maintaining the surface tension-lowering properties of pulmonary surfactant. Surfactant protein A (SP-A) and D (SP-D) are extremely hydrophilic and are thought to have a role in recycling surfactant and especially in improving host defense in the lung. Moreover, SP-A supports the hydrophobic surfactant proteins during surfactant sub- type assembly and inhibits secretion of lamellar bodies into the alveolar space. During recent years surfactant proteins have also been detected at locations outside the lung such as the lacrimal apparatus. In this review, the latest information regarding SP function and regulation in the human lacrimal system, the tear film and the ocular surface is summarized with regard to mucous epithelial integrity, rheological and antimicrobial properties of the tear film, tear outflow, certain disease states and possible therapeutic perspectives.