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.     

Predictors of diagnosis and survival in idiopathic pulmonary fibrosis and connective tissue disease-related usual interstitial pneumonia

Background

Although usual interstitial pneumonia (UIP) appears to portend better survival when associated with connective tissue disease (CTD-UIP), little is known about the presenting clinical, radiologic, and pathologic features that differentiate pathologically confirmed UIP with CTD from idiopathic pulmonary fibrosis (IPF). In patients with atypical radiologic and clinical features, what specific findings predict underlying IPF vs. CTD-UIP diagnosis and their respective long term survival?

Methods

A large retrospective cohort analysis was done of consecutive patients seen from 1995 through 2010 with biopsy confirmed UIP completed or reviewed at our institution. CTD-UIP was defined by independent rheumatology consultation with exclusion of all other secondary causes of lung fibrosis. Primary clinical data was collected and compared for IPF and CTD-UIP along with logistic regression performed for predictors of disease likelihood and Cox proportional hazards analysis for predictors of survival.

Results

Six hundred and twenty five patients were included in the study of which 89 had diagnosed CTD-UIP representing 7 disease entities. Survival was better among those with CTD-UIP except in UIP associated with rheumatoid arthritis, which had similar presenting features and survival to IPF. Predictors of underlying CTD included female gender, younger age, positive autoimmune serology, and inconsistent presenting radiologic findings. Only age and forced vital capacity corrected for a priori covariates were predictive of survival in CTD-UIP.

Conclusions

UIP pathology occurs frequently among patients with atypically presenting clinical and radiologic features, and may represent IPF or CTD-UIP with improved prognosis if underlying CTD is diagnosed. Presenting radiologic and pathologic features alone are not predictive of underlying secondary cause or survival between the two groups.     

Second harmonic generation microscopy reveals altered collagen microstructure in usual interstitial pneumonia versus healthy lung

Background

It is not understood why some pulmonary fibroses such as cryptogenic organizing pneumonia (COP) respond well to treatment, while others like usual interstitial pneumonia (UIP) do not. Increased understanding of the structure and function of the matrix in this area is critical to improving our understanding of the biology of these diseases and developing novel therapies. The objectives herein are to provide new insights into the underlying collagen- and matrix-related biological mechanisms driving COP versus UIP.

Methods

Two-photon second harmonic generation (SHG) and excitation fluorescence microscopies were used to interrogate and quantify differences between intrinsic fibrillar collagen and elastin matrix signals in healthy, COP, and UIP lung.

Results

Collagen microstructure was different in UIP versus healthy lung, but not in COP versus healthy, as indicated by the ratio of forward-to-backward propagating SHG signal (F_SHG/B_SHG). This collagen microstructure as assessed by F_SHG/B_SHG was also different in areas with preserved alveolar architecture adjacent to UIP fibroblastic foci or honeycomb areas versus healthy lung. Fibrosis was evidenced by increased col1 and col3 content in COP and UIP versus healthy, with highest col1:col3 ratio in UIP. Evidence of elastin breakdown (i.e. reduced mature elastin fiber content), and increased collagen:mature elastin ratios, were seen in COP and UIP versus healthy.

Conclusions

Fibrillar collagen’s subresolution structure (i.e. “microstructure”) is altered in UIP versus COP and healthy lung, which may provide novel insights into the biological reasons why unlike COP, UIP is resistant to therapies, and demonstrates the ability of SHG microscopy to potentially distinguish treatable versus intractable pulmonary fibroses.     

Distribution of collagens type I,type III and type V in the pancreas of rat,dog, pig and man

The presence of collagens type I, type III and type V was determined immunohistochemically in pancreatic tissue of rat, pig, dog and man. The reaction to anti-collagen type I is weak (pig, dog) or moderate (rat, man) in the peri-insular region and in the lobar, lobular and acinar septa, whereas the reaction to anti-collagen type III is well developed. In rat and dog, the latter reaction deposit on the lobar and acinar septa is prominent. These elements only show a moderate reaction intensity in pig and man. The peri-insular region displays a weak (rat, dog, man) or very weak (pig) reaction against collagen type III. Anti-collagen type V reacts moderately (rat, dog, man) or weakly (pig) in the lobar and lobular septa. The acinar septa show a moderate (rat, dog, man) or very weak (pig) reaction. This information regarding the types and distribution of the collagenous compounds in pancreatic extracellular matrix could lead to differentiated enzymatic pancreas dissociation and, ultimately, increased islet yield and improved reproducibility of pancreatic islet isolation procedures for transplantation purposes.     

High molecular weight vimentin complex is formed after proteolytic digestion of vimentin by caspase-3: detection by sera of patients with interstitial pneumonia

In a previous study, we demonstrated anti-vimentin antibodies in sera of patients with interstitial pneumonia. We hypothesized that antibodies in sera might detect vimentin fragments formed during the process of apoptosis. To prove this, recombinant human vimentin was digested by recombinant human caspase-3 or caspase-8. Then, Western blotting using several commercially available antibodies against human vimentin or patients' sera which had anti-vimentin autoantibodies, was performed. As a result, after recombinant human vimentin was digested by caspase-3 or caspase-8, several vimentin fragments were formed and detected by 2 kinds of monoclonal anti-vimentin antibodies (clone 3B4 and clone V9) as well as by polyclonal sheep anti-human vimentin antibody. It was demonstrated that high molecular weight vimentin was formed after the digestion of vimentin by caspase-3, which was only detected by patients' sera. The high molecular weight vimentin was not formed after digestion of vimentin by caspase-8. Our present results show that high molecular weight vimentin was formed after the digestion of vimentin by caspase-3. In addition, it is suggested that this high molecular weight vimentin acted as an autoantigen to form anti-vimentin autoantibody in vivo.     

Expression of HSP47 in Usual Interstitial Pneumonia and Nonspecific Interstitial Pneumonia

Background

Heat shock protein (HSP) 47, a collagen-specific molecular chaperone, is involved in the processing and/or secretion of procollagens, and its expression is increased in various fibrotic diseases. The aim of this study was to determine whether quantitative immunohistochemical evaluation of the expression levels of HSP47, type I procollagen and α-smooth muscle actin (SMA) allows the differentiation of idiopathic usual interstitial pneumonia (UIP) from UIP associated with collagen vascular disease (CVD) and idiopathic nonspecific interstitial pneumonia (NSIP).

Methods

We reviewed surgical lung biopsy specimens of 19 patients with idiopathic UIP, 7 with CVD-associated UIP and 16 with idiopathic NSIP and assigned a score for the expression of HSP47, type I procollagen and α-SMA in type II pneumocytes and/or lung fibroblasts (score 0 = no; 1 = weak; 2 = moderate; 3 = strong staining).

Results

The expression level of HSP47 in type II pneumocytes of idiopathic UIP was significantly higher than in CVD-associated UIP and idiopathic NSIP. The expression of HSP47 in fibroblasts was significantly higher in idiopathic UIP and idiopathic NSIP than in CVD-associated UIP. The expression of type I procollagen in type II pneumocytes was significantly higher in idiopathic UIP than in idiopathic NSIP. The expression of type I procollagen in fibroblasts was not different in the three groups, while the expression of α-SMA in fibroblasts was significantly higher in idiopathic UIP than in idiopathic NSIP.

Conclusion

Our results suggest the existence of different fibrotic pathways among these groups involved in the expression of HSP47 and type I procollagen.     

Up-regulation of THY1 attenuates interstitial pulmonary fibrosis and promotes lung fibroblast apoptosis during acute interstitial pneumonia by blockade of the WNT signaling pathway

Acute interstitial pneumonia (AIP) is an idiopathic pulmonary disease featuring rapid progressive dyspnea and respiratory failure. These symptoms typically develop within several days or weeks in patients without any pre-existing lung disease or external chest disease. Thymocyte differentiation antigen-1 (THY1) has been reported to have an effect on lung fibroblast proliferation and fibrogenic signaling. In this study, the mechanism of THY1 in AIP in influencing pulmonary fibrosis in terms of lung fibroblast proliferation and apoptosis was examined. An AIP mouse model with the pathological changes of lung tissues observed was established to identify the role of THY1 in the pathogenesis of AIP. The expression of THY1, a key regulator of the WNT pathway β-catenin and fibroblasts markers MMP-2, Occludin, α-SMA and Vimentin were determined. Lung fibroblasts of mice were isolated, in which THY1 expression was altered to identify roles THY1 plays in cell viability and apoptosis. A TOP/TOPflash assay was utilized to determine the activation of WNT pathway. Decrement of pulmonary fibrosis was achieved through THY1 up-regulation. The expression of MMP-2, Occludin, α-SMA, Vimentin and β-catenin, and the extent of β-catenin phosphorylation, significantly decreased, thereby indicating that THY1 overexpression inactivated WNT. Cell proliferation was inhibited and apoptosis was accelerated in lung fibroblasts transfected with vector carrying overexpressed THY1. Altogether, this study defines the potential role of THY1 in remission of AIP, via the upregulation of THY1, which renders the WNT pathway inactive. This inactivation of the WNT signaling pathway could alleviate pulmonary fibrosis by reducing lung fibroblast proliferation in AIP.

Abbreviations: AIP: Acute interstitial pneumonia; ILDs: interstitial lung diseases; DAD: diffuse alveolar damage; SPF: specific-pathogen-free; NC: negative control; HCMV: human cytomegalovirus; HE: Hematoxylin-eosin; RIPA: radio-immunoprecipitation assay; SDS-PAGE: sodium dodecyl sulfate-polyacrylamide gel electrophoresis; BSA: bovine serum albumin; HRP: horseradish peroxidase; ECL: electrochemiluminescence; FBS: fetal bovine serum; DMSO: dimethyl sulfoxide; OD: optical density     

Circulating peripheral blood fibrocytes in human fibrotic interstitial lung disease

Fibrotic interstitial lung diseases are illnesses of unknown cause characterized by progressive decline in lung function. Fibrocytes are bone marrow-derived, circulating progenitor cells capable of differentiating into diverse mesenchymal cell types. Prior work has shown fibrocytes to traffic to the lung via the CXCL12-CXCR4 chemokine axis in an animal model of pulmonary fibrosis. We therefore assessed the relevance of fibrocytes in patients with fibrotic interstitial lung disease. We found enhanced expression of CXCL12 in both the lungs and plasma of patients with lung fibrosis. CXCL12 levels were associated with an order of magnitude higher number of circulating fibrocytes in the peripheral blood of these patients. Most of the circulating fibrocytes in patients with interstitial lung diseases were negative for the myofibroblast marker alpha-smooth muscle actin, suggesting a relatively undifferentiated phenotype. Taken together, these data suggest that fibrocytes are involved in the pathogenesis of human lung fibrosis.     

Characterization of lymphocyte populations in nonspecific interstitial pneumonia*

Study objectives

Nonspecific interstitial pneumonia (NSIP) has been identified as a distinct entity with a more favorable prognosis and better response to immunosuppressive therapies than usual interstitial pneumonia (UIP). However the inflammatory profile of NSIP has not been characterized.

Design

Using immunohistochemistry techniques on open lung biopsy specimens, the infiltrate in NSIP was characterized in terms of T and B cells, and macrophages, and the T cell population further identified as either CD4 (helper) or CD8 (suppressor-cytotoxic) T cells. The extent of Th1 and Th2 cytokine producing cells was determined and compared to specimens from patients with UIP.

Results

In ten NSIP tissue samples 41.4 ± 4% of mononuclear cells expressed CD3, 24.7 ± 1.8% CD4, 19.1 ± 2% CD8, 27.4 ± 3.9% CD20, and 14.3 ± 1.6% had CD68 expression. Mononuclear cells expressed INFγ 21.9 ± 1.9% of the time and IL-4 in 3.0 ± 1%. In contrast, biopsies from eight patients with UIP demonstrated substantially less cellular staining for either cytokine (INFγ; 4.6 ± 1.7% and IL-4; 0.6 ± 0.3%). Significant populations of CD20 positive B-cells were also identified.

Conclusion

The lymphocytic infiltrate in NSIP is characterized by an elevated CD4/CD8 T-cell ratio, and is predominantly of Th1 type, with additional populations rich in B-cells. Such features are consistent with the favorable clinical course observed in patients with NSIP compared to UIP.     

Serum biomarkers in interstitial lung diseases

The use of biomarkers in medicine lies in their ability to detect disease and support diagnostic and therapeutic decisions. New research and novel understanding of the molecular basis of the disease reveals an abundance of exciting new biomarkers who present a promise for use in the everyday clinical practice. The past fifteen years have seen the emergence of numerous clinical applications of several new molecules as biologic markers in the research field relevant to interstitial lung diseases (translational research). The scope of this review is to summarize the current state of knowledge about serum biomarkers in interstitial lung diseases and their potential value as prognostic and diagnostic tools and present some of the future perspectives and challenges.     

Serum procollagen type III is associated with elevated right-sided filling pressures in stable outpatients with congestive heart failure

Elevated filling pressures are associated with heart failure deterioration, but mechanisms underlying this association remain poorly understood. We sought to investigate whether or not elevated filling pressures are associated with increased collagen turnover, evaluated by procollagen type III aminoterminal peptide (PIIINP) levels, in stable systolic heart failure. Eighty patients with heart failure with severe systolic dysfunction (ejection fraction 26?±?7%) were included. Patients underwent simultaneous echocardiogram with evaluation of haemodynamic parameters and blood sampling for PIIINP measurement. Mean PIIINP level was 6.11?±?2.62 μg l^?1. PIIINP was positively associated with estimated right atrial pressure (RAP) (r?=?0.36; p?=?0.001). Mean PIIINP values were 5.04?±?2.42 μg l^?1 in patients with estimated RAP ≤?5?mmHg, and 7.59?±?2.54 μg l^?1 in those with RAP >?15?mmHg (p?相似文献   

血清标记物在类风湿关节炎相关间质性肺疾病中的作用

类风湿关节炎相关间质性肺疾病(rheumatoid arthritis-associated interstitial lung disease, RA-ILD)是类风湿关节炎(rheumatoid arthritis, RA)最具破坏性的并发症,一旦发展成普通型间质性肺炎模式,患者的死亡率急剧上升,且缺乏有效的治疗手段和特异性的诊断方法。血清标记物,特别是MMPs、KL-6、SP-D、CCL18、OPN、WNT5A、Anti-CarP抗体、抗MAA抗体、抗PAD抗体等,可以早期识别RA-ILD的高危患者,预测亚型、评价疗效、监测预后,日益受到人们关注。本文就血清标记物与RAILD异常表达和肺纤维化发生、进展及预后的相关性作一综述,旨在为RA-ILD寻找可靠的血清标记物,为临床诊治工作提供参考。     

Computer simulation of Gd(III) speciation in human interstitial fluid

The speciation and distribution of Gd(III) in human interstitial fluid was studied by computer simulation. The results show that at the background concentration, all the Gd(III) species are soluble and no precipitates appear. However as the total concentration of Gd(III) rises above 2.610 × 10^–9 mol/l,the insoluble species become predominant. GdPO₄ is formed first as a precipitate and then Gd₂(CO₃)₃. Among soluble species, free Gd(III), [Gd(HSA)], [Gd(Ox)] and the ternary complexes of Gd(III) with citrate as the primary ligand are main species when the total concentration of Gd(III) is below 2.074 × 10^–2 mol/l. With the total concentration of Gd(III) further rising, [Gd₃(OH)₄] begins to appear and gradually becomes a predominant species.     

Symmetric Arginine Dimethylation Is Selectively Required for mRNA Splicing and the Initiation of Type I and Type III Interferon Signaling

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Corneal and scleral type I collagens: analyses of physical properties and molecular flexibility

The physical properties of type I collagen were studied by electron microscopy of rotary shadowed collagen molecules and laser light scattering techniques. The physical properties, molecular structure and flexibility of type I collagen molecules from two structurally and functionally different connective tissues, cornea and sclera, were similar when measured in HCl, pH 2.0. The molecular weights were 328 and 298 × 10² for corneal and scleral type I collagen, respectively, while the values of T_M were 33.7°C for both preparations. These values were in agreement with those obtained for other type I collagens. The higher level of glycosylation in corneal versus scleral type I collagen did not significantly modify the physical properties of type I collagen in acid solution or the charge distribution along the molecule as determined from the positively stained SLS banding patterns. Our morphological studies indicated that the collagen molecule, although relatively flexible based on electron microscopy, behaved as a long thin rod in solution. The mean end-to-end distances measured from electron micrographs were 253 and 256 nm for corneal and cler type I collagen, respectively, while the molecular contour lengths were 298 and 305 nm. The translational diffusion coefficients (0.849 and 0.857 × 10^?7cm²s^?1) were consistent with the contour lengths while the reported values in the literature for the rotational diffusion coefficient of type I collagen were consistent with the end-to-end distances. The intermediate value for molecular length obtained from the particle scattering factor (277 nm) reflects contributions from all possible molecular configurations.     

Kinetics of hydrolysis of type I, II, and III collagens by the class I and II Clostridium histolyticum collagenases.

The kinetics of hydrolysis of rat tendon type I, bovine nasal septum type II, and human placental type III collagens by class I and class IIClostridium histolyticum collagenases (CHC) have been investigated. To facilitate this study, radioassays developed previously for the hydrolysis of these [³H]acetylated collagens by tissue collagenases have been adapted for use with the CHC. While the CHC are known to make multiple scissions in these collagens, the assays are shown to monitor the initial proteolytic events. The individual kinetic parametersk _cat andK _M have been determined for the hydrolysis of all three collagens by both class I and class II CHC. The specific activities of these CHC toward fibrillar type I and III collagens have also been measured. In contrast to human tissue collagenases, neither class of CHC exhibits a marked specificity toward any collagen type either in solution or in fibrillar form. The values of the kinetic parametersk _cat andK _M for the CHC are similar in magnitude to those of the human enzymes acting on their preferred substrates. Thus, the widely held view that the CHC are more potent collagenases is not strictly correct. As with the tissue collagenases, the local collagen structure at the cleavage sites is believed to play an important role in determining the rates of the reactions studied.     

Identification and characterization of a type III secretion-associated chaperone in the type III secretion system 1 of Vibrio parahaemolyticus

Vibrio parahaemolyticus causes human gastroenteritis. Genomic sequencing of this organism has revealed that it has two sets of type III secretion systems, T3SS1 and T3SS2, both of which are important for its pathogenicity. However, the mechanism of protein secretion via T3SSs is unknown. A characteristic of many effectors is that they require specific chaperones for efficient delivery via T3SSs; however, no chaperone has been experimentally identified in the T3SSs of V. parahaemolyticus . In this study, we identified candidate T3SS1-associated chaperones from genomic sequence data and examined their roles in effector secretion/translocation and binding to their cognate substrates. From these experiments, we concluded that there is a T3S-associated chaperone, VecA, for a cytotoxic T3SS1-dependent effector, VepA. Further analysis using pulldown and secretion assays characterized the chaperone-binding domain encompassing the first 30–100 amino acids and an amino terminal secretion signal encompassing the first 5–20 amino acids on VepA. These findings will provide a strategy to clarify how the T3SS1 of V. parahaemolyticus secretes its specific effectors.