The complex of porcine seminal plasma heterodimers I and II (PSP-I/PSP-II), which are heterodimers of glycosylated spermadhesins, is the major component of porcine seminal fluid. The proinflammatory and immunostimulatory activities of this spermadhesin complex suggest its participation in modulation of the uterine immune activity that may ensure reproductive success. Spermadhesin PSP-I/PSP-II induced the migration of neutrophils into the peritoneal cavity of rats via activation of resident cells. In the present study, we have investigated the involvement of macrophages and mast cells in the neutrophil chemotactic activity of PSP-I/PSP-II and the underlying mechanism. Macrophages and mast cells were isolated, cultured, and stimulated with purified PSP-I/PSP-II. Pharmacological modulation was performed using the glucocorticoid dexamethasone, indomethacin (cyclooxygenase inhibitor), MK886 (leukotriene inhibitor), and the supernatant of spermadhesin-stimulated mast cells. Macrophages stimulated with PSP-I/PSP-II released into the culture supernatant a neutrophil chemotactic substance. This activity was partly inhibited by both dexamethasone (85%) and the supernatant of spermadhesin-stimulated mast cells (74%) but not by indomethacin and MK886. An anti-tumor necrosis factor (TNF) alpha antibody neutralized (by 68%) the neutrophil chemotactic activity of PSP-I/PSP-II-stimulated macrophages. An anti-interleukin (IL)-4 antibody blocked the inhibitory activity of spermadhesin-stimulated mast cells on release of a neutrophil chemotactic substance by PSP-I/PSP-II-stimulated macrophages. As a whole, these data indicate that the neutrophil migration-inducing ability of spermadhesin PSP-I/PSP-II involves the release of the inflammatory cytokine TNFalpha by stimulated macrophages and that this activity is modulated by the lymphokine IL-4 liberated by mast cells. The balance between these two cytokines may control onset of the local inflammatory reaction, avoiding excessive neutrophil recruitment that would lead to tissue damage.
Background and purpose Severe diarrhoea, a common gastrointestinal manifestation of anticancer treatment with irinotecan, might involve single nucleotide polymorphisms (SNPs) of toll‐like receptors (TLRs), described as critical bacterial sensors in the gut. Here, colorectal cancer patients carrying missense TLR4 A896G (rs4986790) or C1,196T (rs4986791) SNPs and Tlr4 knockout (Tlr4−/−) mice were given irinotecan to investigate the severity of the induced diarrhoea. Experimental approach Forty‐six patients treated with irinotecan‐based regimens had diarrhoea severity analysed according to TLR4 genotypes. In the experimental setting, wild‐type (WT) or Tlr4−/− mice were given irinotecan (45 or 75 mg·kg−1, i.p.) or saline (3 ml·kg−1). Diarrhoea severity was evaluated by measuring intestinal injury and inflammatory markers expression after animals were killed. Key results All patients with TLR4 SNPs chemotherapy‐treated presented diarrhoea, whereas gastrointestinal toxicity was observed in 50% of the wild homozygous individuals. Mice injected with irinotecan presented systemic bacterial translocation and increased TLR4 immunostaining in the intestine. In line with the clinical findings, Tlr4 gene deficiency enhanced irinotecan‐related diarrhoea and TLR9 expression in mice. An increased myeloperoxidase activity and Il‐18 expression along with IL‐10 decreased production in Tlr4−/− mice also indicated an intensified intestinal damage and inflammatory response. Conclusion and implications TLR4 deficiency upregulates TLR9 expression and enhances intestinal damage and the severity of late‐onset diarrhoea during irinotecan‐based treatment. Identifying patients genetically predisposed to chemotherapy‐associated diarrhoea is a strategy toward precision medicine.
Spermadhesins are a group of (glyco)proteins from seminal fluid involved in various aspects of porcine fertilization. PSP-I/PSP-II, a heterodimer of glycosylated spermadhesins, is the major component of porcine seminal fluid. Its biological function remains, however, enigmatic. Using an in vitro chemotaxis assay, we showed that PSP-I/PSP-II and its isolated subunits induced migration of purified neutrophils. A possible proinflammatory activity of PSP-I/PSP-II induced upon injection of the spermadhesin heterodimer and its isolated subunits into the peritoneal cavity of rats was investigated. Lavage of peritoneal cavities, thioglycolate treatment, and mast cell depletion were done before spermadhesin administration, and neutrophil migration was evaluated 4 h after injections. Pharmacological modulation was also investigated. Resident cell depletion by lavage reduced the neutrophil migration induced by PSP-I/PSP-II and the PSP-II subunit but had no effect on that induced by isolated PSP-I. Both an increase of macrophage population by thioglycolate treatment and mast cell depletion potentiated the neutrophil migration induced by PSP-I/PSP-II and by PSP-II. The glucocorticoid dexamethasone but not indomethacin (cyclooxygenase inhibitor), MK886 (leukotriene inhibitor), and BN50739 (platelet activation factor [PAF] antagonist) inhibited neutrophil migration induced by PSP-I/PSP-II. Coincubation with mannose-6-phosphate (a PSP-II-specific ligand) inhibited neutrophil recruitment induced by PSP-II but did not alter the PSP-I activity. As a whole, the data suggested that enhancement of the neutrophil migration-inducing activity of PSP-I/PSP-II and PSP-II involved an indirect mechanism, i.e., via activation of resident cells, probably macrophages. On the other hand, PSP-I appeared to act directly on neutrophils. We hypothesize that the neutrophil migration-inducing effect displayed by PSP-II might be due to interaction of its lectin domain with cellular receptors and that neutrophil recruitment induced by PSP-I may involve protein-protein interactions.
Gastric cancer is among the ten most common types of cancer worldwide. Most cases and deaths related to the disease occur in developing countries. Local socioeconomic , epidemiologic and healthcare particularities led us to create a Brazilian guideline for the management of gastric carcinomas. The Brazilian Group of Gastrointestinal Tumors (GTG) invited 50 physicians with different backgrounds, including radiology, pathology, endoscopy, nuclear medicine, genetics, oncological surgery, radiotherapy and clinical oncology, to collaborate. This document was prepared based on an extensive review of topics related to heredity,
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