ABSTRACT
Cudrania tricuspidata Bureau (CTB), a species of the Moraceae plant, has been used as a bruise recovery treatment. This study aimed to determine whether the 75 kDa phytoglycoprotein extracted from CTB has a regulatory effect on the proliferation of human colon epithelial cells and the pathological process of inflammatory bowel disease (IBD). We found that CTB glycoprotein significantly induces the proliferation of human colon epithelial HT-29 cells by activating protein kinase C. CTB glycoprotein stimulated the phosphorylation of c-Jun N-terminal kinase and transcription factor nuclear factor-κB, which are responsible for the expression of cell-cycle-related proteins (CDK2, CDK4, cyclin D1 and cyclin E) during its promotion of cell proliferation. Experimental colitis was induced in mice by adding dextran sulfate sodium to their drinking water at a concentration of 4% (W/V) for seven days. We found that CTB glycoprotein ameliorates the pathological process of IBD and lowers the disease activity index score, which was composed of body weight change, diarrhea, and hematochezia in ICR mice treated with dextran sulfate sodium. Hence, we suggest that CTB glycoprotein has the ability to prevent IBD by promoting cell proliferation signaling events via the activation of PKC, JNK and NF-κB in colon epithelial cells.
ABSTRACT
Dioscorea batatas Decne (DBD) has been used to heal various illnesses of the kidney and intestine as an herbal medicine in Asia. As a source of therapeutic agents, many glycoproteins have been isolated from mushrooms and plants, but the functional role of glycoprotein in intestinal epithelial wound healing has not been understood yet. In the present study, we investigated the wound healing potentials of the 30 kDa glycoprotein (DBD glycoprotein) isolated from DBD in human intestinal epithelial (INT-407) cells. We found that DBD glycoprotein (100 μg·mL) significantly increased the motility of INT-407 cells for 24 h by activating protein kinase C (PKC). DBD glycoprotein stimulated the activation of p38 mitogen-activated protein kinase (MAPK), which is responsible for the phosphorylation of NF-κB inhibitor α (IκBα). DBD glycoprotein increased the level of profilin-1 (PFN1), α-actinin and F-actin expression via activation of transcription factor, nuclear factor-kappa B (NF-κB) during its promotion of cell migration. Experimental mouse colitis was induced by adding dextran sulfate sodium (DSS) to the drinking water at a concentration of 4% (W/V) for 7 days. We figured out that administration of DBD glycoprotein (10 and 20 mg·kg) lowers the levels of disease activity index and histological inflammation in DSS-treated ICR mice. In this regard, we suggest that DBD glycoprotein has ability to promote the F-actin-related migration signaling events via activation of PKC and NF-κB in intestinal epithelial cells and prevent inflammatory bowel disease.
ABSTRACT
The gut epithelial barrier, which is composed of the mucosal layer and the intestinal epithelium, has multiple defense mechanisms and interconnected regulatory mechanisms against enteric microbial pathogens. However, many bacterial pathogens have highly evolved infectious stratagems that manipulate mucin production, epithelial cell-cell junctions, cell death, and cell turnover to promote their replication and pathogenicity in the gut epithelial barrier. In this review, we focus on current knowledge about how bacterial pathogens regulate mucin levels to circumvent the epithelial mucus barrier and target cell-cell junctions to invade deeper tissues and increase their colonization. We also describe how bacterial pathogens manipulate various modes of epithelial cell death to facilitate bacterial dissemination and virulence effects. Finally, we discuss recent investigating how bacterial pathogens regulate epithelial cell turnover and intestinal stem cell populations to modulate intestinal epithelium homeostasis.
Subject(s)
Colon , Defense Mechanisms , Epithelial Cells , Homeostasis , Intercellular Junctions , Intestinal Mucosa , Mucins , Mucus , Stem Cells , Tight Junctions , VirulenceABSTRACT
Stem cells have attracted much attention due to their distinct features that support infinite self-renewal and differentiation into the cellular derivatives of three lineages. Recent studies have suggested that many stem cells both embryonic and adult stem cells reside in a specialized niche defined by hypoxic condition. In this respect, distinguishing functional differences arising from the oxygen concentration is important in understanding the nature of stem cells and in controlling stem cell fate for therapeutic purposes. ROS act as cellular signaling molecules involved in the propagation of signaling and the translation of environmental cues into cellular responses to maintain cellular homeostasis, which is mediated by the coordination of various cellular processes, and to adapt cellular activity to available bioenergetic sources. Thus, in this review, we describe the physiological role of ROS in stem cell fate and its effect on the metabolic regulation of stem cells.