Th17/Treg imbalance plays a pivotal role in COPD development and progression. We aimed to assess Th17/Treg-related intracellular signaling at different COPD stages in local and systemic responses. Lung tissue and/or peripheral blood samples were collected and divided into non-obstructed (NOS), COPD stages I and II, and COPD stages III and IV groups. Gene expression of STAT3 and -5, RORγt, Foxp3, interleukin (IL)-6, -17, -10, and TGF-β was assessed by RT-qPCR. IL-6, -17, -10, and TGF-β levels were determined by ELISA. We observed increased STAT3, RORγt, Foxp3, IL-6, and TGF-β gene expression and IL-6 levels in the lungs of COPD I and II patients compared to those of NOS patients. Regarding the systemic response, we observed increased STAT3, RORγt, IL-6, and TGF-β gene expression in the COPD III and IV group and increased IL-6 levels in the COPD I and II group. STAT5 was increased in COPD III and IV patients, although there was a decrease in Foxp3 expression and IL-10 levels in the COPD I and II and COPD III and IV groups, respectively. We demonstrated that an increase in Th17 intracellular signaling in the lungs precedes this increase in the systemic response, whereas Treg intracellular signaling varies between the compartments analyzed in different COPD stages.

Patients with Systemic sclerosis (SSc) presents immune dysregulation, vasculopathy, and fibrosis of the skin and various internal organs. Pulmonary fibrosis leads to SSc-associated interstitial lung disease (ILD), which is the main cause of morbidity and mortality in SSc. Recently autoimmunity to type V collagen (Col V) has been characterized in idiopathic pulmonary fibrosis and show promise to be related to the development in SSc. Our aim was to evaluate autoimmunity to Col V α1(V) and α2(V) chains and to the antigenic peptides of these Col V chains in early-SSc sera employing lung tissue of SSc-ILD, as antigen source. We found that sera samples from patients with early-SSc were reactive to Col V (41.18%) and presented immunoreactivity for Col5A1(1.049) and Col5A1(1.439) peptides. The IgG isolated from early-SSc patients-anti-Col V positive sera (anti-ColV IgG) was adsorbed with α1(V) chain (anti-ColV IgG/ads-α1(V)) and α2(V) chain (anti-ColV IgG/ads-α2(V)) and biotinylated to evaluate the spectrum of reactivity in SSc-ILD patients lung biopsies by immunofluorescence. The SSc-ILD lung tissue samples immunostained with anti-ColV IgG showed increased green fluorescence in the vascular basement membrane, bronchiolar smooth muscle, and adventitial layer, contrasting with the tenue immunostaining in control lungs. Col V protein expression in these pulmonary compartments immunostained with early-SSc anti-ColV IgG was confirmed by immune colocalization assays with commercial anti-human Col V antibodies. In addition, SSc-ILD lung tissues immunostained with anti-ColV IgG/ads-α1(V) (sample in which Col V α1 chain-specific antibodies were removed) showed decreased green fluorescence compared to anti-ColV IgG and anti-ColV IgG/ads-α2(V). Our data show that autoimmunity to Col V in early-SSc was related to peptides of the α1(V) chain, suggesting that these antibodies could be biomarkers of SSc stages and potential target of immunotherapy with Col V immunogenic peptides.

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 (U_Na) 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 U_Na, 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.

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.

Type V collagen (Col V) has been implicated in the development of fibrosis in systemic sclerosis (SSc). In this study, we aimed to investigate the role of Col V in fibrillar matrix remodeling and fibroblast differentiation using an experimental SSc model. Skin fibroblasts from healthy C57BL/6 mice were stimulated in vitro with 25 and 50 μg of Col V to assess fibrillar collagen expression. An SSc model was induced in C57BL/6 mice by immunization with Col V emulsified in Freund’s adjuvant (IMU-COLV), with animals assigned to 15-, 30-, and 45-day IMU-COLV or control groups. In vitro, Col V stimulation caused a dose-dependent increase in myofibroblast markers (α-SMA, Col I, and Col V) and altered fibrillar collagen structure. Immunofluorescence revealed thickened Col V and Col III fibrils around myofibroblasts and the formation of a spiderweb-like matrix. In vivo, fibrosis progressed over time, characterized by increased myofibroblast accumulation and elevated Col I and Col V levels. Histological analysis revealed fibrillar disorganization and aggregated collagen fibers resembling early-stage human SSc. These findings suggest that enhanced Col V synthesis disrupts the fibrillar matrix, promoting myofibroblast differentiation and collagen deposition, which are hallmarks of SSc-related fibrosis.

Systemic sclerosis (SSc) is a complex autoimmune disease characterized by progressive fibrosis and immune dysregulation, with lung involvement being a major cause of morbidity and mortality. Type V collagen (COLV), a cryptic self-antigen, has been implicated in the pathogenesis of fibrosis in both SSc and lung allograft dysfunction. To characterize the early histological, molecular, and immunological events associated with lung remodeling following immunization with COLV in a murine model (IMU-COLV), and to establish a temporal framework for fibrosis progression. Using a time-course design, lung tissue from IMU-COLV mice was analyzed at multiple intervals post-immunization. Histopathological assessment, immunohistochemistry, and gene expression analysis were performed to evaluate inflammation, endothelial activation, extracellular matrix remodeling, and collagen composition. We observed a progressive and spatially organized pattern of lung remodeling, beginning with peribronchovascular immune infiltration and culminating in airway-centered fibrosis. These changes were accompanied by dynamic endothelial activation, increased expression of profibrotic markers, and alterations in collagen architecture particularly involving COLV. The remodeling pattern closely mirrors histological features observed in early SSc-associated interstitial lung disease and other fibrotic conditions, such as idiopathic pulmonary fibrosis and chronic lung allograft dysfunsion. The IMU-COLV model recapitulates key early features of SSc-related lung fibrosis, highlighting COLV’s potential role as a driver of immune-mediated tissue remodeling. These findings provide a valuable platform for investigating the mechanisms underlying fibrogenesis and for testing targeted interventions in the early phases of pulmonary fibrosis.