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.     

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。     

血小板源性生长因子C：脏器纤维化治疗的新兴靶点

脏器纤维化是一种严重的不可逆病理生理过程,尤其在肝、肾、肺、心等关键脏器中表现尤为显著。因其病因及复杂的发病机制尚未完全明确,给该疾病的诊治和预防带来了巨大的挑战。血小板源性生长因子C(platelet-derived growth factor-C,PDGF-C)是由多种细胞分泌的促有丝分裂因子,可通过自分泌或旁分泌途径,在生物体内发挥关键的生物学效应。PDGF-C能够激活上皮细胞、内皮细胞、免疫细胞以及成纤维细胞,诱导其在纤维化进程中进行增殖与迁移,促进细胞外基质成分的过度沉积,共同调控纤维化的发生发展。此外,PDGF-C还可与PDGF受体（PDGFR）特异性结合,进而激活JAK/STAT、PI3K/AKT、Ras-MAPK等多种信号转导途径,进一步加速纤维化进程。多项研究表明,在脏器纤维化进程中,PDGF-C因表达量呈现上调趋势的特点,有望成为治疗脏器纤维化疾病的潜在新兴靶点。本文综述了PDGF-C的结构功能、表达调控及其在脏器纤维化中的作用机制,同时探讨了靶向PDGF-C/PDGFR通路抑制剂的研发与应用前景,旨在为脏器纤维化的诊治及新药开发提供新的策略,促进相关领域的研究发展与思考。     

A gelatin-specific protease from hamster lung-derived cell cultures

Summary Gelatin-specific protease activity from hamster lung fibroblasts and their culture media is described. The fibroblasts were derived from hamster lung explant cultures. The gelatin-specific protease activity is latent and seen only after dialysis of either cells or media. The enzyme activity shares many properties of previously reported gelatinases. The activity is inhibited by EDTA, cysteine, and dithioerythritol, whereas it is not inhibited byp-chloromecuribenzoate,N-ethyl maleimide, or phenylmethylsulfonyl fluoride. Of all substrates tested, activity was observed only against gelatin and not against other substrates tested. It was inactive toward collagen, elastin, and methemoglobin. This enzyme may have a role in the digestion of collagen that has been previously cleaved by mammalian collagenase. This research was supported by Program Project Grant HL-19717 from the National Heart, Lung, and Blood Institute, Grant AG 000-38-02 from the National Institute of Aging, and National Institute of Health Grant 5T32HL07035.     

Rapid and reversible regulation of collagen XII expression by changes in tensile stress

We studied the expression of the fibril-associated collagen XII by fibroblasts cultured on attached (stretched) or floating (relaxed) collagen I gels. Accumulation of collagen XII in the medium as determined by semiquantitative immunoblotting was 8-16 times higher under stretched compared to relaxed conditions. Northern blot experiments showed that tensile stress controls collagen XII expression at the mRNA level. Tenascin-C mRNA levels were also influenced, whereas relative amounts of fibronectin and matrix metalloproteinase-2 mRNA were barely affected. The response to a change in tensile stress is rapid, since de novo biosynthesis of collagen XII was fully down-regulated 12 h after relaxation of a stretched culture. To demonstrate that the effect is also reversible, we mounted collagen gels with attached cells to movable polyethylene plugs. The cultures were relaxed or stretched at intervals of 24 and 48 h, and media samples were analyzed every 24 h. By ELISA, the amount of collagen XII secreted into the medium was found to increase or decrease in accordance with the tensile stress applied. This is evidence that the mechanical stimulus per se, rather than an indirect secondary effect, was responsible for the observed changes in collagen XII production.     

De-differentiation of primary human hepatocytes depends on the composition of specialized liver basement membrane

Despite the understanding of the importance of mitogen-activated protein (MAP) kinase activation in the stimulation of growth, little is known about the role of MAP kinase regulation during contact inhibited growth control. To investigate the role of the MAP kinase extracellular signal-regulated kinase (ERK) during the transition to a contact inhibited state, cultures of normal fibroblasts (BJ) were grown to different stages of confluency. The levels of MAP kinase phosphatase (MKP) expression and the amount of active ERK and MAP ERK kinase (MEK) in these cultures were assessed through western blot analysis and were compared to fibrosarcoma cell cultures (HT-1080), which lack contact inhibition. In normal fibroblasts, the amounts of active MEK and ERK decline at contact inhibition, concurrently with a rise in MKP-1, MKP-2, and MKP-3 protein levels. In contrast, fibrosarcoma cells appear to lack density-dependent regulation of the ERK pathway. Additionally, altering the redox environment of fibrosarcoma cells to a less reducing state, as seen during contact inhibition, results in increased MKP-1 expression. Taken together, these results suggest that the altered redox environment upon contact inhibition may contribute to the regulation of ERK inactivation by MKPs.     

Structural Basis for the Acceleration of Procollagen Processing by Procollagen C-Proteinase Enhancer-1

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Purification and characterization of extracellular alkaline serine protease from Stenotrophomonas maltophilia strain S-1

AIMS: The present study was conducted by screening soil bacteria in an attempt to isolate a bacterium that produced extracellular alkaline protease, and for purification and characterization of the protease. METHODS AND RESULTS: Soil bacteria were screened by growth on casein as the sole carbon source. Characterization of a strain isolated from soil of Abashiri, Japan indicated a taxonomic affiliation to Stenotrophomonas maltophilia, and was named S-1 strain. The purified S-1 protease, designed S. maltophilia Protease-1 (SmP-1), exhibited an optimal pH of 12.0, optimal reaction temperature of 50 degrees C and a molecular mass of approximately 40 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The cleavage sites of the oxidized-insulin B chain by SmP-1 were identified as Leu6-Cys7, Cys7-Gly8, Tyr16-Leu17 and Leu17-Val18. The N-terminal amino acid sequence of the purified alkaline protease was determined as NH2-SASAPMVSGVAALVLE. CONCLUSION: A novel extracellular alkaline serine protease was isolated from S. maltophilia strain S-1. The optimal pH of the proteolytic activity was pH 12.0. SIGNIFICANCE AND IMPACT OF THE STUDY: The extremely high optimal pH and heat stability of the alkaline serine protease SmP-1 might make it widely applicable to food and other industries.     

Interleukin-17 Drives Interstitial Entrapment of Tissue Lipoproteins in Experimental Psoriasis

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Effect of angiotensin II on myocardial collagen gene expression

Molecular and Cellular Biochemistry - Recent studies suggest that angiotensin II (angiotensin) may be involved in the regulation of metabolism of the cardiac extracellular matrix (ECM). Two major...     

Myocardial matrix metalloproteinase(s): localization and activation

Matrix metalloproteinases (MMPs) and neutrophil elastate (NE) may each contribute to fibrillar collagen degradation in various disease states. Little, however, is known about the activation and localization of MMP in the heart. Accordingly, we extracted MMP and examined mechanisms of proMMP activation in whole tissue extracts of the adult rat myocardium. Incubation of extracts with serine proteases (i.e., trypsin or neutrophil elastase) at 37°C resulted in a time-dependent activation of proMMPs. Based on immunoblot and measurements of MMP activity by zymography, the molecular weight of active MMP was deduced to be 52 kDa. The second-order rate constant for activation of proMMP by serine protease was 5.5±0.2×10⁵ M^–1min^–1 and for oxidized glutathione (GSSG) 1.5±0.1 M^–1min^–1. Incubation of the extract with both serine protease and GSSG increased the rate of activation 30-fold. Based on reverse zymographic analysis of collagenase inhibition, tissue inhibitors of metalloproteinases were identified. Indirect immunofluorescence localized proMMPs/MMPs to the endothelium and subendothelial space of the endocardium and throughout the interstitial space found between groups of muscle fibers. These results suggest that the mechanism of activation of MMPs by either a serine protease and by oxidizing, thiol-modifying reagents are mechanistically different and the presence of either a serine protease or GSSG synergistically increase the rate of activation of proMMPs. Our results also suggest that MMPs may be regulated by its own endogenous inhibitors. The contribution of this proteolytic enzyme to tissue remodeling and wound healing responses that occur in various diseases states remains to be established.Abbreviations GSSG Oxidized Glutathione - MMP Matrix Metalloproteinase - NE Neutrophil Elastase - TIMP Tissue Inhibitor of Metalloproteinase     

Neoplastic association of enhanced type V collagen production in rat fibrosarcoma

Collagens present in the connective tissues of the extracellular matrix of fibrosarcoma were isolated and characterized. The fibrosarcoma was induced in rats by the administration of 3-methylcholanthrene. The results obtained were compared with normal muscle. An excess amount of type V collagen was found to be produced by the fibrosarcoma tissue compared to the normal muscle. Type V collagen from fibrosarcoma was characterized on the basis of solubility behavior in sodium chloride solutions, electrophoretic mobility on SDS-polyacrylamide gels, elution pattern of phosphocellulose chromatography and amino acid composition.     

抗bFGF抗体对肺纤维化模型的干预作用

目的:研究抗bFGF抗体对大鼠肺纤维化模型的干预作用及可能的机制。方法:雌性Wistar大鼠30只,体重180～250g,按照随机数字表法将大鼠随机分为3组(n=10):①对照组(C组);②模型组(M组);③抗bFGF抗体组(K组)。M、K组给大鼠气管内注入博莱霉素复制肺纤维化模型,C组气管内注入同等剂量的生理盐水作对照,K组于造模后1,2,3,8,12,19,25d腹腔内注射抗bFGF抗体。上述各组均于注药后1、4周各宰杀5只。通过苏木素-伊红染色观察肺泡炎、Masson胶原染色观察肺纤维化、用免疫组化及酶联免疫吸附测定(ELISA)法检测bFGF蛋白在大鼠肺组织,血清及肺泡灌洗液(BALF)的表达。结果:在1、4周时M组与C组比较肺泡炎、肺纤维化程度明显,M组在肺组织、血清和的BALF中的bFGF表达与C组的bFGF表达比较升高;在1、4周时K组与M组比较肺泡炎、肺纤维化程度减轻,K组在肺组织、血清和的BALF中的bFGF表达与M组的bFGF表达比较均有降低。结论:抗bFGF抗体可减轻博莱霉素诱导的肺纤维化,其抗纤维化作用的机制与抑制bFGF表达有关。     

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.