Proregenerative Activity of IL-33 in Gastric Tissue Cells Undergoing Helicobacter Pylori-Induced Apoptosis

Abstract

Interleukin (IL)-33 is a proinflammatory mediator that alerts the host immune system to disorders in tissue homeostasis. Aim. To understand the role of IL-33 in modulating gastric tissue cell growth affected by Helicobacter pylori (H. pylori). Methods. IL-33 production in guinea pigs (Caviae porcellus) experimentally infected with H. pylori was evaluated by ELISA or immunohistochemical staining. The proregenerative activity of IL-33 was evaluated using gastric epithelial cells and fibroblasts that were naive or transfected with IL-33 siRNA exposed to H. pylori glycine acid extract antigenic complex (GE), as well as by measuring cell migration, proliferation, metabolic activity and apoptosis. Animals infected by H. pylori responded with increased production of IL-33. Also, cells treated in vitro with GE released more IL-33 than cells that were unstimulated. Silencing IL-33 in cells resulted in downregulation of metabolic activity, adhesion, migration and proliferation, especially after treatment with H. pylori GE, as well as upregulation of cells apoptosis associated with caspase 3 increase and Bcl-xL decrease, suggesting proregenerative activity of IL-33. Interestingly, upregulation of cell proliferation by IL-33 was Erk independent. Our results indicate that IL-33 may protect gastric tissue from loss of homeostasis caused by deleterious effects of H. pylori components and the inflammatory response developed during infection.

Use of Fourier-Transform Infrared Spectroscopy (FT-IR) for Monitoring Experimental Helicobacter pylori Infection and Related Inflammatory Response in Guinea Pig Model

“…In our model, the status of H . pylori infection in guinea pigs was confirmed at 28 days after inoculation of animals with these bacteria, by histological, molecular, and serological methods, as previously described [ 56 , 57 ]. The gastric mucosa of guinea pigs inoculated with H .…”

“…Previously we developed an experimental model of H. pylori infection in guinea pigs, which was followed by the inflammatory response in gastric tissue, similarly to humans infected with these bacteria [56,57,72]. This model allowed us to study the outcome of H. pylori-driven inflammatory and immune responses as well as induction of regeneration processes in the gastric tissue in response to this infection [72,73].…”

“…Previously we developed an experimental model of H. pylori infection in guinea pigs, which was followed by the inflammatory response in gastric tissue, similarly to humans infected with these bacteria [ 56 , 57 , 72 ]. This model allowed us to study the outcome of H .…”

“…For this purpose, we used sera of uninfected animals ( n = 20) or animals experimentally infected with H. pylori ( n = 40). H. pylori infection was confirmed in all guinea pigs that received H. pylori, as previously described [ 56 , 57 , 73 ]. Infrared spectra were measured using an FT-IR Spectrum 400 spectrometer in the range of wavenumber 3000–750 cm −1 and then subjected to mathematical pre-processing (calculation of first derivative).…”

“…Three-month-old, male Himalayan guinea pigs (400-600 g), free of pathogens, were housed in the Animal House at the Faculty of Biology and Environmental Protection, University of Lodz (Poland), kept in cages with free access to drinking water and fed with standard chow. The animals were inoculated per os with bacterial suspension of the reference H. pylori strain CCUG 17874 (Culture Collection University of Gothenburg, Sweden), three times in two day intervals as previously described [56,57]. Then, 28 days after the last H. pylori inoculation, the animals were euthanized according to a protocol approved by an ethics committee, and the gastric tissue was collected for analyses, whereas blood samples were processed to obtain serum and then stored at −80 • C. H. pylori infection was confirmed by microscopic imaging of HLOs, scoring tissue inflammation in thin layer preparations stained by routine histological staining, polymerase chain reaction (PCR) to detect H. pylori cagA and ureC gene sequences, as previously described [56].…”