Preventive approach against drug-induced pulmonary fibrosis through the suppression of epithelial-mesenchymal transition

A number of drugs induce pulmonary injury and subsequently lead to serious lung diseases such as pulmonary fibrosis as the adverse drug reactions. However, an effective preventive approach against drug-induced pulmonary fibrosis has not been established due to poor understanding of common preventive targets in a variety of drugs showing pulmonary toxicity. Epithelial-mesenchymal transition (EMT), a cellular phenotypic change of the epithelial to mesenchymal state, contributes to the development of pulmonary fibrosis through the conversion of damaged alveolar epithelium into myofibroblasts. As several drugs with pulmonary toxicity have been reported to induce EMT, EMT serves as a bridge between the drugs and pulmonary fibrosis. Accumulated evidence supports the potential of EMT as a preventive target against drug-induced pulmonary fibrosis. Additionally, since there are mechanistic differences between the main pharmacological effect and EMT induced by the drug, prevention based on EMT suppression would be possible and would contribute to continuous clinical treatment with the drug to avoid EMT-mediated serious pulmonary fibrosis. Furthermore, targeting EMT seems to be adequate for exerting a preventive effect since EMT in damaged alveolar epithelial cells occurs prior to the development of the pathophysiological state of the whole lung in a bleomycin-induced lung injury rat model. This viewpoint deals with the benefits and perspectives of preventive approaches against druginduced pulmonary fibrosis through the suppression of EMT, which has rarely been addressed.     

Dry powders for the inhalation of ciprofloxacin or levofloxacin combined with a mucolytic agent for cystic fibrosis patients

Objective: This study aimed to design and characterize an inhalable dry powder of ciprofloxacin or levofloxacin combined with the mucolytics acetylcysteine and dornase alfa for the management of pulmonary infections in patients with cystic fibrosis.

Methods: Ball milling, homogenization in isopropyl alcohol and spray drying processes were used to prepare dry powders for inhalation. Physico-chemical characteristics of the dry powders were assessed via thermogravimetric analysis, differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR), X-ray diffractometry and scanning electron microscopy. The particle size distribution, dissolution rate and permeability across Calu-3 cell monolayers were analyzed. The aerodynamic parameters of dry powders were determined using the Andersen cascade impactor (ACI).

Results: After the micronization process, the particle sizes of the raw materials significantly decreased. X-ray and DSC results indicated that although ciprofloxacin showed no changes in its crystal structure, the structure of levofloxacin became amorphous after the micronization process. FT-IR spectra exhibited the characteristic peaks for ciprofloxacin and levofloxacin in all formulations. The dissolution rates of micro-homogenized and spray-dried ciprofloxacin were higher than that of untreated ciprofloxacin. ACI results showed that all formulations had a mass median aerodynamic diameter less than 5?μm; however, levofloxacin microparticles showed higher respirability than ciprofloxacin powders did. The permeability of levofloxacin was higher than those of the ciprofloxacin formulations.

Conclusion: Together, our study showed that these methods could suitably characterize antibiotic and mucolytic-containing dry powder inhalers.     

Prediction of the antigenic sites of the cystic fibrosis transmembrane conductance regulator protein by molecular modelling

Antibodies are powerful tools for studying the in situ localizationand physiology of proteins. The prediction of epitopes by molecularmodelling has been used successfully for the papilloma virus,and valuable antibodies have been raised [Muller et aL (1990)J. Gen. Virol, 71, 2709–2717]. We have improved the modellingapproach to allow us to predict epitopes from the primary sequencesof the cystic fibrosis transmembrane conductance regulator.The procedure involves searching for fragments of primary sequenceslikely to make amphipathic secondary structures, which are hydrophilicenough to be at the surface of the folded protein and thus accessibleto antibodies. Amphipathic helices were predicted using themethods of Berzofsky, Eisenberg and Jahnig. Their hydrophobichydrophilicinterface was calculated and drawn, and used to predict theorientation of the helices at the surface of the native protein.Amino acids involved in turns were selected using the algorithmof Eisenberg. Tertiary structures were calculated using ‘FOLDING’,a software developed by R.Brasseur for the prediction of smallprotein structures [Brasseur (1995) J. MoL Graphics, in press].We selected sequences that folded as turns with at least fiveprotruding polar residues. One important property of antibodiesis selectivity. To optimize the selectivity of the raised antibodies,each sequence was screened for similarity (FASTA) to the proteinsequences from several databanks. Ubiquitous sequences werediscarded. This approach led to the identification of 13 potentialepitopes in the cystic fibrosis transmembrane conductance regulator:seven helices and six loops.     

维生素E对大鼠残肾纤维化的抑制作用

目的 观察维生素E对慢性肾衰残肾组织进行性纤维化的抑制作用。方法 在5/6肾切除大鼠慢性肾衰模型上, 以假手术大鼠为对照, 采用形态计量和生化测定方法, 对比分析术后30、60、90、120 天给予或不给予维生素E 治疗的慢性肾衰大鼠残肾纤维化程度。结果 大鼠行5/6 肾切除术后, 在残存肾小球代偿性肥大、肾小球毛细血管代偿性增生的同时, 肾小球显著硬化, 滤过膜显著增厚, 肾间质显著纤维化, 肾组织羟脯氨酸含量显著增高;而用维生素E 治疗的大鼠, 肾小球硬化、滤过膜增厚、肾间质纤维化和肾组织羟脯氨酸含量增高的程度显著减轻, 肾小球代偿性肥大和肾小球毛细血管代偿性增生的发生时间后移。结论 维生素E 能显著抑制5/6 肾切除所致慢性肾衰残肾组织的纤维化, 对其代偿性肾小球肥大和毛细血管增生无明显直接影响。     

Understanding the Renal Fibrotic Process in Leptospirosis

Leptospirosis is a neglected infectious disease caused by pathogenic species of the genus Leptospira. The acute disease is well-described, and, although it resembles other tropical diseases, it can be diagnosed through the use of serological and molecular methods. While the chronic renal disease, carrier state, and kidney fibrosis due to Leptospira infection in humans have been the subject of discussion by researchers, the mechanisms involved in these processes are still overlooked, and relatively little is known about the establishment and maintenance of the chronic status underlying this infectious disease. In this review, we highlight recent findings regarding the cellular communication pathways involved in the renal fibrotic process, as well as the relationship between renal fibrosis due to leptospirosis and CKD/CKDu.