RESUMEN
BACKGROUND: Infection with Helicobacter pylori, a high-risk factor for gastric cancer, is frequently associated with chronic inflammation through activation of nuclear factor κB (NF-κB). Trefoil factor 1 (TFF1) is a constitutively expressed protein in the stomach that has tumor-suppressor functions and plays a critical role in maintaining mucosal integrity. This study investigated the role of TFF1 in regulating the proinflammatory response to H. pylori infections. METHODS: For in vitro studies, immunofluorescence, luciferase reporter assays, Western blots, and quantitative real-time polymerase chain reaction were performed to investigate the activation of NF-κB and its target genes in response to infections with H. pylori strains J166 and 7.13. In addition, Tff1-knockout (KO) and Tff1-wild-type mice were used for infections with the H. pylori strain called premouse Sydney strain 1. RESULTS: The reconstitution of TFF1 expression in gastric cancer cells significantly suppressed H. pylori-mediated increases in NF-κB-p65 nuclear staining, transcriptional activity, and expression of proinflammatory cytokine genes (tumor necrosis factor α, interleukin 1ß, chemokine [C-X-C motif] ligand 5, and interleukin 4 receptor) that were associated with reductions in the expression and phosphorylation of NF-κB-p65 and IκB kinase α/ß proteins. The in vivo studies using the Tff1-KO mouse model of gastric neoplasia confirmed the in vitro findings. Furthermore, they demonstrated increases in chronic inflammation scores and in the frequency of invasive gastric adenocarcinoma in the Tff1-KO mice infected with H. pylori versus the uninfected Tff1-KO mice. CONCLUSIONS: These findings underscore an important protective role of TFF1 in abrogating H. pylori-mediated inflammation, a crucial hallmark of gastric tumorigenesis. Therefore, loss of TFF1 expression could be an important step in H. pylori-mediated gastric carcinogenesis.
Asunto(s)
Adenocarcinoma/genética , Carcinogénesis/genética , Mucosa Gástrica/metabolismo , Infecciones por Helicobacter/genética , Péptidos/genética , Neoplasias Gástricas/genética , Adenocarcinoma/inmunología , Adenocarcinoma/microbiología , Animales , Quimiocina CXCL5/inmunología , Mucosa Gástrica/inmunología , Mucosa Gástrica/microbiología , Infecciones por Helicobacter/inmunología , Helicobacter pylori , Humanos , Quinasa I-kappa B/metabolismo , Técnicas In Vitro , Inflamación , Interleucina-1beta/inmunología , Ratones , Ratones Noqueados , Fosforilación , Reacción en Cadena en Tiempo Real de la Polimerasa , Receptores de Interleucina-4/inmunología , Estómago/inmunología , Estómago/microbiología , Neoplasias Gástricas/inmunología , Neoplasias Gástricas/microbiología , Factor de Transcripción ReIA/metabolismo , Factor Trefoil-1 , Células Tumorales Cultivadas , Factor de Necrosis Tumoral alfa/inmunologíaRESUMEN
Previous studies have demonstrated that mesenchymal stromal cells (MSCs) enhance cell survival through upregulation and secretion of stanniocalcin-1 (STC1). This study shows that MSC-derived STC1 promotes survival of lung cancer cells by uncoupling oxidative phosphorylation, reducing intracellular reactive oxygen species (ROS), and shifting metabolism towards a more glycolytic metabolic profile. MSC-derived STC1 upregulated uncoupling protein 2 (UCP2) in injured A549 cells in an STC1-dependent manner. Knockdown of UCP2 reduced the ability of MSCs and recombinant STC1 (rSTC1) to reduce cell death in the A549 population. rSTC1-treated A549 cells displayed decreased levels of ROS, mitochondrial membrane potential (MMP), and increased lactate production, all of which were dependent on the upregulation of UCP2. Our data suggest that MSCs can promote cell survival by regulating mitochondrial respiration via STC1.
Asunto(s)
Apoptosis , Glicoproteínas/metabolismo , Células Madre Mesenquimatosas/metabolismo , Neoplasias/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Anaerobiosis , Apoptosis/efectos de los fármacos , Comunicación Autocrina/genética , Glucólisis , Glicoproteínas/genética , Humanos , Canales Iónicos/genética , Canales Iónicos/metabolismo , Proteínas Mitocondriales/genética , Proteínas Mitocondriales/metabolismo , Neoplasias/genética , Comunicación Paracrina/genética , Especies Reactivas de Oxígeno/farmacología , Proteína Desacopladora 2RESUMEN
Multipotent stromal cells (MSCs) ameliorate several types of lung injury. The differentiation of MSCs into specific cells at the injury site has been considered as the important process in the MSC effect. However, although MSCs reduce destruction in an elastase-induced lung emphysema model, MSC differentiation is relatively rare, suggesting that MSC differentiation into specific cells does not adequately explain the recuperation observed. Humoral factors secreted by MSCs may also play an important role in ameliorating emphysema. To confirm this hypothesis, emphysema was induced in the lungs of C57BL/6 mice by intratracheal elastase injection 14 days before intratracheal MSC or phosphate-buffered saline (PBS) administration. Thereafter, lungs were collected at several time points and evaluated. Our results showed that MSCs reduced the destruction in elastase-induced emphysema. Furthermore, double immunofluorescence staining revealed infrequent MSC engraftment and differentiation into epithelial cells. Real-time PCR showed increased levels of hepatocyte growth factor (HGF) and epidermal growth factor (EGF). Real-time PCR and western blotting showed enhanced production of secretory leukocyte protease inhibitor (SLPI) in the lung. In-vitro coculture studies confirmed the in vivo observations. Our findings suggest that paracrine factors derived from MSCs is the main mechanism for the protection of lung tissues from elastase injury.