Type V collagen-induced nasal tolerance prevents lung damage in an experimental model: new evidence of autoimmunity to collagen V in COPD.

Background: Chronic obstructive pulmonary disease (COPD) has been linked to immune responses to lung-associated self-antigens. Exposure to cigarette smoke (CS), the main cause of COPD, causes chronic lung inflammation, resulting in pulmonary matrix (ECM) damage. This tissue breakdown exposes collagen V (Col V), an antigen typically hidden from the immune system, which could trigger an autoimmune response. Col V autoimmunity has been linked to several lung diseases, and the induction of immune tolerance can mitigate some of these diseases. Evidence suggests that autoimmunity to Col V might also occur in COPD; thus, immunotolerance to Col V could be a novel therapeutic approach. Objective: The role of autoimmunity against collagen V in COPD development was investigated by analyzing the effects of Col V-induced tolerance on the inflammatory response and lung remodeling in a murine model of CS-induced COPD. Methods: Male C57BL/6 mice were divided into three groups: one exposed to CS for four weeks, one previously tolerated for Col V and exposed to CS for four weeks, and one kept in clean air for the same period. Then, we proceeded with lung functional and structural evaluation, assessing inflammatory cells in bronchoalveolar lavage fluid (BALF) and inflammatory markers in the lung parenchyma, inflammatory cytokines in lung and spleen homogenates, and T-cell phenotyping in the spleen. Results: CS exposure altered the structure of elastic and collagen fibers and increased the pro-inflammatory immune response, indicating the presence of COPD. Col V tolerance inhibited the onset of emphysema and prevented structural changes in lung ECM fibers by promoting an immunosuppressive microenvironment in the lung and inducing Treg cell differentiation. Conclusion: Induction of nasal tolerance to Col V can prevent inflammatory responses and lung remodeling in experimental COPD, suggesting that autoimmunity to Col V plays a role in COPD development.

Aerobic Exercise Training Protects Against Insulin Resistance, Despite Low-Sodium Diet-Induced Increased Inflammation and Visceral Adiposity.

Dietary sodium restriction increases plasma triglycerides (TG) and total cholesterol (TC) concentrations as well as causing insulin resistance and stimulation of the renin-angiotensin-aldosterone system (RAAS) and the sympathetic nervous system. Stimulation of the angiotensin II type-1 receptor (AT1) is associated with insulin resistance, inflammation, and the inhibition of adipogenesis. The current study investigated whether aerobic exercise training (AET) mitigates or inhibits the adverse effects of dietary sodium restriction on adiposity, inflammation, and insulin sensitivity in periepididymal adipose tissue. LDL receptor knockout mice were fed either a normal-sodium (NS; 1.27% NaCl) or a low-sodium (LS; 0.15% NaCl) diet and were either subjected to AET for 90 days or kept sedentary. Body mass, blood pressure (BP), hematocrit, plasma TC, TG, glucose and 24-hour urinary sodium (UNa) concentrations, insulin sensitivity, lipoprotein profile, histopathological analyses, and gene and protein expression were determined. The results were evaluated using two-way ANOVA. Differences were not observed in BP, hematocrit, diet consumption, and TC. The LS diet was found to enhance body mass, insulin resistance, plasma glucose, TG, LDL-C, and VLDL-TG and reduce UNa, HDL-C, and HDL-TG, showing a pro-atherogenic lipid profile. In periepididymal adipose tissue, the LS diet increased tissue mass, TG, TC, AT1 receptor, pro-inflammatory macro-phages contents, and the area of adipocytes; contrarily, the LS diet decreased anti-inflammatory macrophages, protein contents and the transcription of genes related to insulin sensitivity. The AET prevented insulin resistance, but did not protect against dyslipidemia, adipose tissue pro-inflammatory profile, increased tissue mass, AT1 receptor expression, TG, and TC induced by the LS diet.

Alpha-7 Nicotinic Receptor Agonist Protects Mice Against Pulmonary Emphysema Induced by Elastase.

Pulmonary emphysema is a primary component of chronic obstructive pulmonary disease (COPD), a life-threatening disorder characterized by lung inflammation and restricted airflow, primarily resulting from the destruction of small airways and alveolar walls. Cumulative evidence suggests that nicotinic receptors, especially the α7 subtype (α7nAChR), is required for anti-inflammatory cholinergic responses. We postulated that the stimulation of α7nAChR could offer therapeutic benefits in the context of pulmonary emphysema. To investigate this, we assessed the potential protective effects of PNU-282987, a selective α7nAChR agonist, using an experimental emphysema model. Male mice (C57BL/6) were submitted to a nasal instillation of porcine pancreatic elastase (PPE) (50 µl, 0.667 IU) to induce emphysema. Treatment with PNU-282987 (2.0 mg/kg, ip) was performed pre and post-emphysema induction by measuring anti-inflammatory effects (inflammatory cells, cytokines) as well as anti-remodeling and anti-oxidant effects. Elastase-induced emphysema led to an increase in the number of α7nAChR-positive cells in the lungs. Notably, both groups treated with PNU-282987 (prior to and following emphysema induction) exhibited a significant decrease in the number of α7nAChR-positive cells. Furthermore, both groups treated with PNU-282987 demonstrated decreased levels of macrophages, IL-6, IL-1ß, collagen, and elastic fiber deposition. Additionally, both groups exhibited reduced STAT3 phosphorylation and lower levels of SOCS3. Of particular note, in the post-treated group, PNU-282987 successfully attenuated alveolar enlargement, decreased IL-17 and TNF-α levels, and reduced the recruitment of polymorphonuclear cells to the lung parenchyma. Significantly, it is worth noting that MLA, an antagonist of α7nAChR, counteracted the protective effects of PNU-282987 in relation to certain crucial inflammatory parameters. In summary, these findings unequivocally demonstrate the protective abilities of α7nAChR against elastase-induced emphysema, strongly supporting α7nAChR as a pivotal therapeutic target for ameliorating pulmonary emphysema.

Aerobic Exercise Training Reduces Atherogenesis Induced by Low-Sodium Diet in LDL Receptor Knockout Mice.

This study investigated the efficacy of aerobic exercise training (AET) in the prevention of dyslipidemia, insulin resistance (IR), and atherogenesis induced by severe low-sodium (LS) diet. LDL receptor knockout (LDLR KO) mice were fed a low-sodium (LS) (0.15% NaCl) or normal-sodium (NS; 1.27% NaCl) diet, submitted to AET in a treadmill, 5 times/week, 60 min/day, 15 m/min, for 90 days, or kept sedentary. Blood pressure (BP), plasma total cholesterol (TC) and triglyceride (TG) concentrations, lipoprotein profile, and insulin sensitivity were evaluated at the end of the AET protocol. Lipid infiltration, angiotensin II type 1 receptor (AT1), receptor for advanced glycation end products (RAGE), carboxymethyllysine (CML), and 4-hydroxynonenal (4-HNE) contents as well as gene expression were determined in the brachiocephalic trunk. BP and TC and gene expression were similar among groups. Compared to the NS diet, the LS diet increased vascular lipid infiltration, CML, RAGE, 4-HNE, plasma TG, LDL-cholesterol, and VLDL-TG. Conversely, the LS diet reduced vascular AT1 receptor, insulin sensitivity, HDL-cholesterol, and HDL-TG. AET prevented arterial lipid infiltration; increases in CML, RAGE, and 4-HNE contents; and reduced AT1 levels and improved LS-induced peripheral IR. The current study showed that AET counteracted the deleterious effects of chronic LS diet in an atherogenesis-prone model by ameliorating peripheral IR, lipid infiltration, CML, RAGE, 4-HNE, and AT1 receptor in the intima-media of the brachiocephalic trunk. These events occurred independently of the amelioration of plasma-lipid profile, which was negatively affected by the severe dietary-sodium restriction.

Is the colon mucosa affected by ten days of gastric restriction in an animal model?

Purpose: To identify whether the colon mucosa is affected by ten days of gastric restriction in an animal model. Methods: An experimental model of gastric restriction was devised using rats. The animals were submitted to surgical gastrostomy, and a cylindrical loofah was inserted into the stomach. We studied 30 adult male Wistar rats divided into three groups: the stomach restriction group (R10); the sham group (S10), which underwent the same procedure except for the loofah insertion; and the control group (C10). The expression of neutral and acid mucins was evaluated using histochemical techniques. Goblet cells and protein content were compared between groups using generalized estimation equations (GEEs). Bonferronis multiple comparison was applied to identify differences between the groups. All tests considered a 5% significance level. Results: There was an increased expression of neutral mucins, acid mucins and goblet cells in the R10 group. Collagen was also enhanced in the R10 group. Conclusion: The colon mucosa is affected by ten days of gastric restriction in an animal model, increasing neutral mucins, acid mucins and collagen content with trophic maintenance.(AU)

Is the colon mucosa affected by ten days of gastric restriction in an animal model?

PURPOSE: To identify whether the colon mucosa is affected by ten days of gastric restriction in an animal model. METHODS: An experimental model of gastric restriction was devised using rats. The animals were submitted to surgical gastrostomy, and a cylindrical loofah was inserted into the stomach. We studied 30 adult male Wistar rats divided into three groups: the stomach restriction group (R10); the sham group (S10), which underwent the same procedure except for the loofah insertion; and the control group (C10). The expression of neutral and acid mucins was evaluated using histochemical techniques. Goblet cells and protein content were compared between groups using generalized estimation equations (GEEs). Bonferroni's multiple comparison was applied to identify differences between the groups. All tests considered a 5% significance level. RESULTS: There was an increased expression of neutral mucins, acid mucins and goblet cells in the R10 group. Collagen was also enhanced in the R10 group. CONCLUSION: The colon mucosa is affected by ten days of gastric restriction in an animal model, increasing neutral mucins, acid mucins and collagen content with trophic maintenance.

Th17/Treg imbalance in COPD progression: A temporal analysis using a CS-induced model.

BACKGROUND: The imbalance between pro- and anti-inflammatory immune responses plays a pivotal role in chronic obstructive pulmonary disease (COPD) development and progression. To clarify the pathophysiological mechanisms of this disease, we performed a temporal analysis of immune response-mediated inflammatory progression in a cigarette smoke (CS)-induced mouse model with a focus on the balance between Th17 and Treg responses. METHODS: C57BL/6 mice were exposed to CS for 1, 3 or 6 months to induce COPD, and the control groups were maintained under filtered air conditions for the same time intervals. We then performed functional (respiratory mechanics) and structural (alveolar enlargement) analyses. We also quantified the NF-κB, TNF-α, CD4, CD8, CD20, IL-17, IL-6, FOXP3, IL-10, or TGF-ß positive cells in peribronchovascular areas and assessed FOXP3 and IL-10 expression through double-label immunofluorescence. Additionally, we evaluated the gene expression of NF-κB and TNF in bronchiolar epithelial cells. RESULTS: Our CS-induced COPD model exhibited an increased proinflammatory immune response (increased expression of the NF-κB, TNF-α, CD4, CD8, CD20, IL-17, and IL-6 markers) with a concomitantly decreased anti-inflammatory immune response (FOXP3, IL-10, and TGF-ß markers) compared with the control mice. These changes in the immune responses were associated with increased alveolar enlargement and impaired lung function starting on the first month and third month of CS exposure, respectively, compared with the control mice. CONCLUSION: Our results showed that the microenvironmental stimuli produced by the release of cytokines during COPD progression lead to a Th17/Treg imbalance.

Is the colon mucosa affected by ten days of gastric restriction in an animal model?

Abstract Purpose To identify whether the colon mucosa is affected by ten days of gastric restriction in an animal model. Methods An experimental model of gastric restriction was devised using rats. The animals were submitted to surgical gastrostomy, and a cylindrical loofah was inserted into the stomach. We studied 30 adult male Wistar rats divided into three groups: the stomach restriction group (R10); the sham group (S10), which underwent the same procedure except for the loofah insertion; and the control group (C10). The expression of neutral and acid mucins was evaluated using histochemical techniques. Goblet cells and protein content were compared between groups using generalized estimation equations (GEEs). Bonferroni's multiple comparison was applied to identify differences between the groups. All tests considered a 5% significance level. Results There was an increased expression of neutral mucins, acid mucins and goblet cells in the R10 group. Collagen was also enhanced in the R10 group. Conclusion The colon mucosa is affected by ten days of gastric restriction in an animal model, increasing neutral mucins, acid mucins and collagen content with trophic maintenance.