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We hypothesized that after synovial injury, collagen V (Col V) expose occult antigens, and Col V autoantibodies develop, indicating the loss of immune tolerance against this molecule, thus leading to damage to mesenchymal-derived cells as well as the extracellular matrix in experimental arthritis. Thus, the present study investigated the effects of oral administration of Col V on the synovium after the development of inflammation in mBSA/CFA-induced arthritis. After fourteen days of intraarticular administration of mBSA, 10 male Lewis rats were orally administered Col V (500 μg/300 μL) diluted in 0.01 N acetic acid (IA-Col V group). The arthritic group (IA group, n = 10) received only intraarticular mBSA. An intra-articular saline injection (20 μL) was given to the control group (CT-Col V, n = 5). IA group presented damaged synovia, the expansion of the extracellular matrix by cellular infiltrate, which was characterized by T and B lymphocytes, and fibroblastic infiltration. In contrast, after Col V oral immunotherapy IA-Col V group showed a significant reduction in synovial inflammation and intense expression of IL-10+ and FoxP3+ cells, in addition to a reduction in Col V and an increase in Col I in the synovia compared to those in the IA group. Furthermore, an increase in IL-10 production was detected after IA-Col V group spleen cell stimulation with Col V in vitro. PET imaging did not differ between the groups. The evaluation of oral treatment with Col V, after mBSA/CFA-induced arthritis in rats, protects against inflammation and reduces synovial tissue damage, through modulation of the synovial matrix, showing an immunotherapeutic potential in inhibiting synovitis., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Ramos da Silveira et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

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., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Robertoni, Velosa, Oliveira, Almeida, Silveira, Queiroz, Lobo, Contini, Baldavira, Carrasco, Fernezlian, Sato, Capelozzi, Lopes and Teodoro.)

Nuclear proliferation marker MIB-1 (Ki-67) immunohistochemistry (IHC) is used to examine tumor cell proliferation. However, the diagnostic or prognostic value of the Ki-67 nuclear staining intensity and location, defined as nuclear gradient (NG), has not been assessed. This study examined the potential association between Ki-67 NG and cell cycle phases and its effect on the prognosis of pulmonary typical carcinoid (PTC) tumors. We propose a method for classifying the NG of Ki-67 during the cell cycle and compare the results between PTC, pulmonary adenocarcinoma (PAD), and breast ductal carcinoma (BDC). A literature review and objective analysis of IHC-stained paraffin sections were used to determine the Ki-67 labeling index and composed a stratification of the NG into NG1, NG2, and NG3/4 categories. A semi-automated image analysis protocol was established to determine the Ki-67 NG in PTC, PAD, and BDC. High intraobserver consistency and moderate interobserver agreement were achieved in the determination of Ki-67 NG in tumor specimens. NG1 and NG2 were lower in PTC than in PAD and BDC. Cox multivariate analysis of PTC after adjusting for age and number of metastatic lymph nodes showed that Ki-67 NG1 and NG2 significantly predicted clinical outcomes. The semi-automated method for quantification of Ki-67 nuclear immunostaining proposed in this study could become a valuable diagnostic and prognostic tool in PTC.

Competing Interests: We declare no competing interests. We would like to thank all health professionals from IIER who provided medical care to the patients, and all autopsy and pathology laboratory technicians from Departamento de Patologia-FMUSP, who collaborated in the analysis of the cases. We acknowledge support from the Medical Research Council–São Paulo Research Foundation CADDE partnership award (MR/S0195/1; FAPESP18/143890; 2013/17159‐2), Wellcome Trust and Royal Society (Sir Henry Dale Fellowship 204311/Z/16/Z), and the Bill & Melinda Gates Foundation (INV-034540; INV-034652; and INV‐002396), and Bolsa de produtividade em pesquisa: Conselho Nacional de Desenvolvimento Científico e Tecnológico 304987/2017-4 (MD).

Background: Fluid regimens in acute respiratory distress syndrome (ARDS) are conflicting. The amount of fluid and positive end-expiratory pressure (PEEP) level may interact leading to ventilator-induced lung injury (VILI). We therefore evaluated restrictive and liberal fluid strategies associated with low and high PEEP levels with regard to lung and kidney damage, as well as cardiorespiratory function in endotoxin-induced ARDS. Methods: Thirty male Wistar rats received an intratracheal instillation of Escherichia coli lipopolysaccharide. After 24 h, the animals were anesthetized, protectively ventilated (V T = 6 ml/kg), and randomized to restrictive (5 ml/kg/h) or liberal (40 ml/kg/h) fluid strategies (Ringer lactate). Both groups were then ventilated with PEEP = 3 cmH 2 O (PEEP3) and PEEP = 9 cmH 2 O (PEEP9) for 1 h ( n = 6/group). Echocardiography, arterial blood gases, and lung mechanics were evaluated throughout the experiments. Histologic analyses were done on the lungs, and molecular biology was assessed in lungs and kidneys using six non-ventilated animals with no fluid therapy. Results: In lungs, the liberal group showed increased transpulmonary plateau pressure compared with the restrictive group (liberal, 23.5 ± 2.9 cmH 2 O; restrictive, 18.8 ± 2.3 cmH 2 O, p = 0.046) under PEEP = 9 cmH 2 O. Gene expression associated with inflammation (interleukin [IL]-6) was higher in the liberal-PEEP9 group than the liberal-PEEP3 group ( p = 0.006) and restrictive-PEEP9 ( p = 0.012), Regardless of the fluid strategy, lung mechanical power and the heterogeneity index were higher, whereas birefringence for claudin-4 and zonula-ocludens-1 gene expression were lower in the PEEP9 groups. Perivascular edema was higher in liberal groups, regardless of PEEP levels. Markers related to damage to epithelial cells [club cell secreted protein (CC16)] and the extracellular matrix (syndecan) were higher in the liberal-PEEP9 group than the liberal-PEEP3 group ( p = 0.010 and p = 0.024, respectively). In kidneys, the expression of IL-6 and neutrophil gelatinase-associated lipocalin was higher in PEEP9 groups, regardless of the fluid strategy. For the liberal strategy, PEEP = 9 cmH 2 O compared with PEEP = 3 cmH 2 O reduced the right ventricle systolic volume (37%) and inferior vena cava collapsibility index (45%). Conclusion: The combination of a liberal fluid strategy and high PEEP led to more lung damage. The application of high PEEP, regardless of the fluid strategy, may also be deleterious to kidneys., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Felix, Maia, Rocha, Rodrigues, Medeiros, da Silva, Baldavira, Fernezlian, Eher, Capelozzi, Malbrain, Pelosi, Rocco and Silva.)

This study aimed to report the effects of different doses of ionizing radiation on inflammatory and repair stage of human skin graft adherence in Nude mice wounds. Animals were divided into transplanted with irradiated human skin grafts (IHSG) at 25 and 50 kGy (IHSG 25 kGy; IHSG 50 kGy) and non-IHSG and euthanized on the 3rd, 7th and 21st days after the surgery, by gross and microscopic changes, immunostaining for human type I collagen (Col I) and mouse Col I and Col III and inflammatory cells. We found an effectiveness of human split-thickness graft adherence in mice transplanted with IHSG 25 kGy, as well decrease in dermo-epidermal necrosis and neutrophils, lower loss of skin thickness, epithelization and neo-vascularization. Day 21 post-transplantation with IHSG 25 kGy was observed a well-preserved human skin in the border of the graft, a prominent granulation tissue in an organization by proliferated fibroblasts, Col III deposition and increased B-cells and macrophages. A complete adherence of human skin graft occurred with IHSG 25 kGy. We suggest that the ionizing radiation at 25 kGy mediates inflammation and the repair stage of human skin graft adherence in murine model, thus emerging as a potential tool in healing cutaneous wounds., Competing Interests: The authors have declared that no competing interests exist.

Background: Type V collagen (Col V) has the potential to become an autoantigen and has been associated with the pathogenesis of systemic sclerosis (SSc). We characterized serological, functional, and histopathological features of the skin and lung in a novel SSc murine model induced by Col V immunization., Methods: Female C57BL/6 mice (n = 19, IMU-COLV) were subcutaneously immunized with two doses of Col V (125 μg) emulsified in complete Freund adjuvant, followed by two intramuscular boosters. The control group (n = 19) did not receive Col V. After 120 days, we examined the respiratory mechanics, serum autoantibodies, and vascular manifestations of the mice. The skin and lung inflammatory processes and the collagen gene/protein expressions were analyzed., Results: Vascular manifestations were characterized by endothelial cell activity and apoptosis, as shown by the increased expression of VEGF, endothelin-1, and caspase-3 in endothelial cells. The IMU-COLV mice presented with increased tissue elastance and a nonspecific interstitial pneumonia (NSIP) histologic pattern in the lung, combined with the thickening of the small and medium intrapulmonary arteries, increased Col V fibers, and increased COL1A1, COL1A2, COL3A1, COL5A1, and COL5A2 gene expression. The skin of the IMU-COLV mice showed thickness, epidermal rectification, decreased papillary dermis, atrophied appendages, and increased collagen, COL5A1, and COL5A2 gene expression. Anti-collagen III and IV and ANA antibodies were detected in the sera of the IMU-COLV mice., Conclusion: We demonstrated that cutaneous, vascular, and pulmonary remodeling are mimicked in the Col V-induced SSc mouse model, which thus represents a suitable preclinical model to study the mechanisms and therapeutic approaches for SSc.

There is an intimate relationship between the extracellular matrix (ECM) and smooth muscle cells within the airways. Few studies have comprehensively assessed the composition of different ECM components and its regulators within the airway smooth muscle (ASM) in asthma. With the aid of image analysis, the fractional areas of total collagen and elastic fibres were quantified within the ASM of 35 subjects with fatal asthma (FA) and compared with 10 nonfatal asthma (NFA) patients and 22 nonasthmatic control cases. Expression of collagen I and III, fibronectin, versican, matrix metalloproteinase (MMP)-1, -2, -9 and -12 and tissue inhibitor of metalloproteinase-1 and -2 was quantified within the ASM in 22 FA and 10 control cases. In the large airways of FA cases, the fractional area of elastic fibres within the ASM was increased compared with NFA and controls. Similarly, fibronectin, MMP-9 and MMP-12 were increased within the ASM in large airways of FA cases compared with controls. Elastic fibres were increased in small airways in FA only in comparison with NFA cases. There is altered extracellular matrix composition and a degradative environment within the airway smooth muscle in fatal asthma patients, which may have important consequences for the mechanical and synthetic functions of airway smooth muscle.

Integrin-immunoglobulin family ligand (CAMs) interactions between lung parenchymal cells (fibroblasts and epithelial cells) and integrin-extracellular matrix component interactions may be involved in the pathogenesis of idiopathic interstitial pneumonia (IIP). Among these, CD34 immunoquantitation allows determination of the degree of vascular proliferation (angiogenesis), whereas VCAM-1 immunoquantitation allows evaluation of the degree of endothelial activity and is strong evidence of inflammation. To validate the importance of vascular proliferation and endothelial cell activity within the alveolar walls and to explore the quantitative relationship between this factor and organizing fibrosis after parenchymal remodeling, we studied surgical lung biopsies in major IIP histologic patterns. We evaluated alveolar vascularity and activity in relation to the various degrees of organizing fibrosis in surgical lung biopsies of diffuse alveolar damage, nonspecific interstitial pneumonia, and usual interstitial pneumonia. Alveolar capillary endothelial cells were intensely immunoreactive with CD34 and VCAM-1. Vascular activity progressively increased in no-organizing fibrotic areas (normal, collapsed, and inflammatory septal areas), whereas vascular density gradually decreased as the degree of organizing fibrosis increased and was lower than that in control lungs in the most extensively fibrotic lesions (mural organizing fibrosis of usual interstitial pneumonia). These results indicate the presence of temporal nonhomogeneic vascular remodeling indiopathic interstitial pneumonia.

Objective: To compare acute pulmonary changes secondary to sodium taurocholate hemorrhagic pancreatitis with those changes secondary to a less severe pancreatitis induced by saline infusion into the biliopancreatic duct., Design: Prospective, randomized controlled trial., Setting: University pulmonary laboratory., Subjects: A total of 110 male Wistar rats., Interventions: Pancreatitis was induced by either 0.5 mL of a 4% solution of sodium taurocholate (TAU group) or 0.5 mL of normal saline (SAL group) injection into the biliopancreatic duct. Data were compared with data from control (sham-operated) animals (SHAM group)., Measurements and Main Results: The severity of pancreatic and pulmonary injuries was evaluated 1, 3, and 8 days after the induction of acute pancreatitis by morphometric and pulmonary mechanical studies. Biliopancreatic duct pressure was measured during infusion of solutions in SAL and TAU groups. SAL and TAU groups developed an intense necrohemorrhagic pancreatitis on day 1 without differences in biliopancreatic duct pressures (134.0+/-45.1 cm H2O vs. 123.3+/-23.4 cm H2O). Acute pancreatic lesions were still intense on day 3 in the TAU group only. Pulmonary resistance in SAL and TAU groups was significantly greater than in the SHAM group on day 3 only. On day 1, there was an increase in intraalveolar edema in both groups (p < .02). There was an increase in polymorphonuclear cells in alveolar septa on day 1 only in the TAU group (p < .001). In contrast, both experimental groups presented greater values of PMN cells on day 8 compared with the SHAM group (p < .001). Both groups with pancreatitis showed an increase in alveolar distention and collapse on day 1 that persisted only in the TAU group on days 3 and 8. No deaths were observed in the control (SHAM) group. In contrast, the SAL group had lower mortality than the TAU group in the first two days (17% and 52%, respectively, p = .03)., Conclusion: High-pressure infusion of normal saline into the biliopancreatic duct of rats results in significant pancreatic and lung alterations. These changes are worse in the presence of sodium taurocholate.

The role of neurokinins in the acute pulmonary response to antigen was studied in guinea pigs that received ovalbumin (50 mg/kg ip) on days 1 and 3 and capsaicin (50 mg/kg sc) on day 21 (OAC); ovalbumin on days 1 and 3 (OA1); capsaicin on day 1 and OA on days 8 and 10 (COA); and ovalbumin on days 8 and 10 (OA2). On day 28, guinea pigs were submitted to ovalbumin aerosol challenge. Maximal values of pulmonary dynamic elastance (Edyn) and pulmonary resistance (RL) were significantly lower in OAC and COA groups compared with OA1 and OA2 groups (P < 0.001). There was no difference between maximal Edyn and RL values obtained in OAC and COA groups. Morphometric analysis of lungs showed significantly (P < 0.05) lower values of contraction index of airways, peribronchial edema, and alveoli over inflation in guinea pigs that received capsaicin compared with intact guinea pigs. Capsaicin treatment did not influence the formation of specific IgG1 anaphylactic antibodies. We conclude that neurokinin depletion results in a decrease in the pulmonary mechanical and inflammatory responses to antigen challenge in sensitized guinea pigs. These effects are observed when capsaicin is given either before or after sensitization.