Immunomodulatory Effects of Adipose-derived Mesenchymal Stem Cells on Epithelial Cells Function in Response to Vibrio cholera in a Co-culture Model

Abstract

Inflammation-induced by the interaction of the Vibrio cholerae with the epithelial cells is considered as a main cause of bacteria spreading through the gastrointestinal tract and its consequences. Because of the immunomodulatory and antibacterial properties of adipose-derived mesenchymal stem cells (AD-MSCs), this study aimed to investigate the effect of AD-MSCs on the interaction of the bacterial-epithelial cell.
 Caco-2 differentiated to intestinal epithelial cells co-cultured with AD-MSCs in a 1:1 ratio of the surface area of six-well plates, for 48 hours. After exposure to Vibrio cholerae, bacterial attachment and internalization were evaluated. Secretions of interleukin (IL-6), prostaglandin E2 (PGE2), and nitric oxide (NO) were also measured using ELISA, and Griess assay, respectively. In addition, the expression of chloratoxin (Ctx-β) and inflammatory cytokines such as TNF-α, IL-1β, and IL-8 were evaluated by real-time polymerase chain reaction (RT-PCR). The rate of apoptosis was also evaluated by Annexin V-PI flow cytometry.
 Bacterial attachment and Ctx-β expression were significantly reduced in the co-culture group compared to the Vibrio cholerae-exposed Caco-2. IL-6 and PGE2 secretion increased in the co-culture group. NO, was also slightly reduced in exposure to Vibrio cholerae. An elevated level of bacterial internalization was observed in the co-culture group compared to the Caco-2 cells leading to an increase in the expression of pro-inflammatory cytokines. The rate of apoptosis was also increased significantly.
 Cell-to-cell contact of AD-MSCs and Caco-2 promoted inflammatory responses and disruption of the epithelium barrier by enhancing bacterial invasion. This may be due to the high expression of surface matrix metalloproteinases on MSCs.

Secretome of adipose derived-mesenchymal stem cells reduces the Vibrio cholerae attachment to Caco-2 cells and subsequent inflammatory responses

“…At the end of the secretome treatment, Caco-2 cells were infected with Vibrio cholerae in two doses of 5 × 10 6 CFU and 2 × 10 7 CFU. The bacterial attachment and invasion were evaluated according to our previous study ( 8 ).…”

“…Caco-2 cells were treated with secretome of Mesenchymal Stem Cells for 48h and then exposed to 5 × 10 6 CFU V. cholerae for 2h. The IL-6 and PGE2 production was evaluated by ELISA assay according to our previous study with the application of mitomycin (10 μg/mL) for the prevention of bacterial growth ( 8 ). Nitric oxide production was also evaluated by Griess assay in collected supernatants after 12 h and 48 h of incubation ( 8 ).…”

“…In spite of the mentioned evidence, our previous study showed that MSCs in direct contact with epithelial cells, induce V. cholerae internalization to epithelial cells followed by an increase in inflammatory cytokine production and apoptosis. We related this result to the formation of the peri-cellular zone of matrix metalloproteinases (MMPs) by MSCs, because MMPs provide the context for the attachment and entry of bacteria into epithelial cells ( 8 ). Since MSCs secrete large amounts of tissue inhibitor matrix metalloproteinases (TIMMPs) that inactivate metalloproteases, the present study was designed to investigate the effect of MSCs secretion on the attachment of V. cholerae to epithelial cells and its inflammatory responses ( 9 ).…”

Mesenchymal Stem Cells and MSCs-Derived Extracellular Vesicles in Infectious Diseases: From Basic Research to Clinical Practice

“…Thus, A-MSCs are able to exert different effects on the inflammatory response and the integrity of the epithelial barrier by reducing bacterial adhesion and enhancing bacterial internalization. The probable reason for this effect is the high level of MSC expression of matrix metalloproteinases and tissue inhibitor of proteinases (TIMP), as well as other antibacterial peptides [ 256 ]. Therefore, it is recommended that future studies focus on the protective effects of MSCs’ secretome.…”