Ana Paula Pereira Velosa

Collagen V-induced nasal tolerance downregulates pulmonary collagen mRNA gene and TGF-beta expression in experimental systemic sclerosis

BackgroundThe purpose of this study was to evaluate collagen deposition, mRNA collagen synthesis and TGF-beta expression in the lung tissue in an experimental model of scleroderma after collagen V-induced nasal tolerance.MethodsFemale New Zealand rabbits (N = 12) were immunized with 1 mg/ml of collagen V in Freunds adjuvant (IM). After 150 days, six immunized animals were tolerated by nasal administration of collagen V (25 μg/day) (IM-TOL) daily for 60 days. The collagen content was determined by morphometry, and mRNA expressions of types I, III and V collagen were determined by Real-time PCR. The TGF-beta expression was evaluated by immunostaining and quantified by point counting methods. To statistic analysis ANOVA with Bonferroni test were employed for multiple comparison when appropriate and the level of significance was determined to be p < 0.05.ResultsIM-TOL, when compared to IM, showed significant reduction in total collagen content around the vessels (0.371 ± 0.118 vs. 0.874 ± 0.282, p < 0.001), bronchioles (0.294 ± 0.139 vs. 0.646 ± 0.172, p < 0.001) and in the septal interstitium (0.027 ± 0.014 vs. 0.067 ± 0.039, p = 0.026). The lung tissue of IM-TOL, when compared to IM, showed decreased immunostaining of types I, III and V collagen, reduced mRNA expression of types I (0.10 ± 0.07 vs. 1.0 ± 0.528, p = 0.002) and V (1.12 ± 0.42 vs. 4.74 ± 2.25, p = 0.009) collagen, in addition to decreased TGF-beta expression (p < 0.0001).ConclusionsCollagen V-induced nasal tolerance in the experimental model of SSc regulated the pulmonary remodeling process, inhibiting collagen deposition and collagen I and V mRNA synthesis. Additionally, it decreased TGF-beta expression, suggesting a promising therapeutic option for scleroderma treatment.

Interstitial and vascular type V collagen morphologic disorganization in usual interstitial pneumonia

Recent evidence suggests that type V collagen plays a role in organizing collagen fibrils, thus maintaining fibril size and spatial organization uniform. In this study we sought to characterize the importance of type V collagen morphological disorganization and to study the relationship between type V collagen, active remodeling of the pulmonary vascular/parenchyma (fibroblastic foci), and other collagen types in usual interstitial pneumonia (UIP). We examined type V collagen and several other collagens in 24 open lung biopsies with histological pattern of UIP from patients with idiopathic pulmonary fibrosis (IPF). We used immunofluorescence, morphometry, and three-dimensional reconstruction to evaluate the amount of collagen V and its interaction with the active remodeling progression in UIP, as well as types I and III collagen fibers. Active remodeling progression was significantly related to type V collagen density (p<0.05), showing a gradual and direct increase to minimal, moderate, and severe fibrosis degree in UIP and in the three different areas: normal, intervening, and mural-organizing fibrosis in UIP. Parenchymal changes were characterized by morphological disorganization of fibrillar collagen with diverse disarray and thickness when observed by three-dimensional reconstruction. We concluded that in the different temporal stages of UIP, vascular/parenchyma collagen type V is increased, in disarray, and is the most important predictor of survival.

Abnormal collagen V deposition in dermis correlates with skin thickening and disease activity in systemic sclerosis.

OBJECTIVE The physiological and mechanical properties of the skin, the primary tissue affected by systemic sclerosis, depend on the assembly of collagen types I, III and V, which form heterotypic fibers. Collagen V (COLV) regulates heterotypic fiber diameter, and the maintenance of its properties is important for maintaining normal tissue architecture and function. Based on a COLV-induced experimental SSc model, in which overexpression of abnormal COLV was a prominent feature, we assumed that this abnormality could be present in SSc patients and could be correlated to disease duration, skin thickening and disease activity. METHODS Skin biopsies from 18 patients (6 early-stage and 12 late-stage) and 10 healthy controls were studied. Skin thickening assessment was performed with the Modified Rodnan Skin Score (MRSS), and activity was calculated using the Valentini Disease Activity Index. Morphology, morphometry of COLV deposition in dermis, as well as, quantitative RT-PCR and 3D-reconstruction of the dermal fibroblast culture were performed. RESULTS Structurally abnormal COLV was overexpressed in SSc skin, mainly in the early stages of the disease, when compared to normal controls and late-stage. A positive correlation between COLV expression and MRSS and disease activity was observed. Collagen V alpha-1 and alpha-2 mRNA expression levels were higher in SSc. Tridimensional reconstruction of SSc dermal heterotypic fibers confirmed the presence of atypical COLV. CONCLUSION Increased synthesis of abnormal COLV and its correlation with disease stage, activity and MRSS suggest that this collagen can be a possible trigger involved in the pathogenesis of SSc.

Changes in histoanatomical distribution of types I, III and V collagen promote adaptative remodeling in posterior tibial tendon rupture

INTRODUCTION Posterior tibial tendon dysfunction is a common cause of adult flat foot deformity, and its etiology is unknown. PURPOSE In this study, we characterized the morphologic pattern and distribution of types I, III and V collagen in posterior tibial tendon dysfunction. METHOD Tendon samples from patients with and without posterior tibial tendon dysfunction were stained by immunofluorescence using antibodies against types I, III and V collagen. RESULTS Control samples showed that type V deposited near the vessels only, while surgically obtained specimens displayed type V collagen surrounding other types of collagen fibers in thicker adventitial layers. Type III collagen levels were also increased in pathological specimens. On the other hand, amounts of collagen type I, which represents 95% of the total collagen amount in normal tendon, were decreased in pathological specimens. CONCLUSION Fibrillogenesis in posterior tibial tendon dysfunction is altered due to higher expression of types III and V collagen and a decreased amount of collagen type I, which renders the originating fibrils structurally less resistant to mechanical forces.

Refractory remodeling of the microenvironment by abnormal type V collagen, apoptosis, and immune response in non-small cell lung cancer ☆

Collagen V shows promise as an inducer of the death response via caspases. Remodeling of the microenvironment by collagen V, tumoral/vascular apoptosis, and the immune response were evaluated, based on the prognosis of 65 patients with surgically excised non-small cell lung cancer. Immunofluorescence, immunohistochemistry, morphometry, tridimensional reconstruction, and a real-time polymerase chain reaction were used to evaluate the amount, structure, and molecular chains of collagen V, tumoral and vascular apoptosis, immune cells, and microvessel density. The impact of these markers was tested on follow-up until death from recurrent lung cancer occurred. A decreased and abnormal synthesis of collagen V was found to lead to increased angiogenesis due to a low endothelial death rate and a low immune response. A Cox model analysis, controlled for the lymph node stage, demonstrated that only collagen V and vascular apoptosis variables were significantly associated with survival time. A point at the median for collagen V and vascular apoptosis divided patients into 2 groups, each with a distinctive prognosis. Those with a collagen V higher than 9.40% and vascular apoptosis higher than 1.09% had a low risk of death (0.27 and 0.41, respectively) compared to those with a collagen V lower than 9.40% and vascular apoptosis lower than 1.09%. Collagen V and vascular apoptosis in resected non-small cell lung cancer was strongly related to the prognosis, suggesting that strategies aimed at preventing low collagen V synthesis, or local responses to low vascular apoptosis may have a greater impact in lung cancer treatment.

Effect of topical clay application on the synthesis of collagen in skin: an experimental study

Background.  Clay is often used in cosmetic treatments, although little is known about its action.

Collagenase mRNA Overexpression and Decreased Extracellular Matrix Components Are Early Events in the Pathogenesis of Emphysema.

To describe the progression of parenchymal remodeling and metalloproteinases gene expression in earlier stages of emphysema, mice received porcine pancreatic elastase (PPE) instillation and Control groups received saline solution. After PPE instillation (1, 3, 6 hours, 3 and 21 days) we measured the mean linear intercept, the volume proportion of types I and III collagen, elastin, fibrillin and the MMP-1, -8, -12 and -13 gene expression. We observed an initial decrease in type I (at the 3rd day) and type III collagen (from the 6th hour until the 3rd day), in posterior time points in which we detected increased gene expression for MMP-8 and -13 in PPE groups. After 21 days, the type III collagen fibers increased and the type I collagen values returned to similar values compared to control groups. The MMP-12 gene expression was increased in earlier times (3 and 6 hours) to which we detected a reduced proportion of elastin (3 days) in PPE groups, reinforcing the already established importance of MMP-12 in the breakdown of ECM. Such findings will be useful to better elucidate the alterations in ECM components and the importance of not only metalloelastase but also collagenases in earlier emphysema stages, providing new clues to novel therapeutic targets.

Histomorphometric analysis of cutaneous remodeling in the early stage of the scleroderma model

INTRODUCTION/OBJECTIVES Systemic sclerosis, or scleroderma, is a rheumatic disease characterized by autoimmunity, vasculopathy, and fibrosis of the skin and several internal organs. In the present study, our aim was to assess the skin alterations in animals with scleroderma during the first stages of disease induction. METHODS: To induce scleroderma, female New Zealand rabbits (n = 12) were subcutaneously immunized with 1 mg/ml of collagen V (Col V) in complete Freund’s adjuvant, twice with a thirty-day interval. Fifteen days later, the animals received an intramuscular booster with type V collagen in incomplete Freund’s adjuvant, twice with a fifteen-day interval. The control group was inoculated with 1 ml of 10 mM acetic acid solution diluted with an equal amount of Freund’s adjuvant. Serial dorsal skin biopsies were performed at 7, 15, and 30 days and stained with H&E, Masson’s trichrome and Picrosírius for morphological and morphometric analyses. RESULTS: Immunized rabbits presented a significant increase in collagen in skin collected seven days after the first immunization (p=0.05). CONCLUSION: The results from this experimental model may be very important to a better understanding of the pathogenic mechanisms involved in the beginning of human SSc. Therapeutic protocols to avoid early remodeling of the skin may lead to promising treatments for SSc in the future.

Abnormal collagen deposition in synovia after collagen type V immunization in rabbits

Sinovitis in Scleroderma (SSc) is rare, usually aggressive and fully resembles rheumatoid arthritis. Experimental models of SSc have been used in an attempt to understand its pathogenesis. Previous studies done in our laboratory had already revealed the presence of a synovial remodeling process in rabbits immunized with collagen V. To validate the importance of collagen type V and to explore the quantitative relationship between this factor and synovia remodeling as well as the relationship between collagen type V and other collagens, we studied the synovial tissue in immunized rabbits. Rabbits (N=10) were immunized with collagen V plus Freunds adjuvant and compared with animals inoculated with adjuvant only (N=10). Synovial tissues were submitted to histological analysis, immunolocalization to collagen I, III and V and biochemical analysis by eletrophoresis, immunoblot and densitometric method. The synovial tissue presented an intense remodeling process with deposits of collagen types I, III and V after 75 and 120 days of immunization, mainly distributed around the vessels and interstitium of synovial extracellular matrix. Densitometric analysis confirmed the increased synthesis of collagen I, III and V chains (407.69+/-80.31; 24.46+/-2.58; 70.51+/-7.66, respectively) in immunized rabbits when compared with animals from control group (164.91+/-15.67; 12.89+/-1.05; 32+/-3.57) (p<0.0001). We conclude that synovial remodeling observed in the experimental model can reflect the articular compromise present in patients with scleroderma. Certainly, this experimental model induced by collagen V immunization will bring new insights in to pathogenic mechanisms and allow the testing of new therapeutic strategies to ameliorate the prognosis for scleroderma patients.

Aerobic Exercise Attenuated Bleomycin-Induced Lung Fibrosis in Th2-Dominant Mice

Introduction The aim of this study was to investigate the effect of aerobic exercise (AE) in reducing bleomycin-induced fibrosis in mice of a Th2-dominant immune background (BALB/c). Methods BALB/c mice were distributed into: sedentary, control (CON), Exercise-only (EX), sedentary, bleomycin-treated (BLEO) and bleomycin-treated+exercised (BLEO+EX); (n = 8/group). Following treadmill adaptation, 15 days following a single, oro-tracheal administration of bleomycin (1.5U/kg), AE was performed 5 days/week, 60min/day for 4 weeks at moderate intensity (60% of maximum velocity reached during a physical test) and assessed for pulmonary inflammation and remodeling, and cytokine levels in bronchoalveolar lavage (BAL). Results At 45 days post injury, compared to BLEO, BLEO+EX demonstrated reduced collagen deposition in the airways (p<0.001) and also in the lung parenchyma (p<0.001). In BAL, a decreased number of total leukocytes (p<0.01), eosinophils (p<0.001), lymphocytes (p<0.01), macrophages (p<0.01), and neutrophils (p<0.01), as well as reduced pro-inflammatory cytokines (CXCL-1; p<0.01), (IL-1β; p<0.001), (IL-5; p<0.01), (IL-6; p<0.001), (IL-13; p<0.01) and pro-fibrotic growth factor IGF-1 (p<0.001) were observed. Anti-inflammatory cytokine IL-10 was increased (p<0.001). Conclusion AE attenuated bleomycin-induced collagen deposition, inflammation and cytokines accumulation in the lungs of mice with a predominately Th2-background suggesting that therapeutic AE (15–44 days post injury) attenuates the pro-inflammatory, Th2 immune response and fibrosis in the bleomycin model.