AB2039 Sigma-AldrichAnti-Elastin Antibody

The pathophysiology of adhesion formation needs to be clarified to reduce the adhesion-related morbidity. The epithelial characteristics of the peritoneum suggest a protective role against adhesion formation, yet how the peritoneum is involved in adhesion formation is not well characterized. We microscopically observed an experimental model of adhesion formation to investigate the effects of an injured tissue on the opposite intact peritoneum. Adhesions were induced between injured and intact hepatic lobes, and the intact peritoneum opposite to the injured tissue was examined for 8 days. The opposite intact peritoneum was denuded of mesothelial cells for 6 hours, and the remnant mesothelial cells changed morphologically for 24 hours. The detachment of mesothelial cells allowed fibrin to attach to the basement membrane of the opposite peritoneum, connecting the two lobes. Moreover, macrophages and myofibroblasts accumulated between the two lobes, and angiogenesis occurred from the opposite intact lobe to the injured lobe. These observations indicate that an injured tissue deprives the opposite intact peritoneum of its epithelial structure and causes fibrous adhesions to the opposite intact tissue. This study implies a possible role of mesothelial cells for barrier function against adhesion formation, that is, keeping mesothelial cells intact might lead to its prophylaxis.

The extracellular matrix (ECM) of the embryonic heart guides assembly and maturation of cardiac cell types and, thus, may serve as a useful template, or blueprint, for fabrication of scaffolds for cardiac tissue engineering. Surprisingly, characterization of the ECM with cardiac development is scattered and fails to comprehensively reflect the spatiotemporal dynamics making it difficult to apply to tissue engineering efforts. The objective of this work was to define a blueprint of the spatiotemporal organization, localization, and relative amount of the four essential ECM proteins, collagen types I and IV (COLI, COLIV), elastin (ELN), and fibronectin (FN) in the left ventricle of the murine heart at embryonic stages E12.5, E14.5, and E16.5 and 2 days postnatal (P2). Second harmonic generation (SHG) imaging identified fibrillar collagens at E14.5, with an increasing density over time. Subsequently, immunohistochemistry (IHC) was used to compare the spatial distribution, organization, and relative amounts of each ECM protein. COLIV was found throughout the developing heart, progressing in amount and organization from E12.5 to P2. The amount of COLI was greatest at E12.5 particularly within the epicardium. For all stages, FN was present in the epicardium, with highest levels at E12.5 and present in the myocardium and the endocardium at relatively constant levels at all time points. ELN remained relatively constant in appearance and amount throughout the developmental stages except for a transient increase at E16.5. Expression of ECM mRNA was determined using quantitative polymerase chain reaction and allowed for comparison of amounts of ECM molecules at each time point. Generally, COLI and COLIII mRNA expression levels were comparatively high, while COLIV, laminin, and FN were expressed at intermediate levels throughout the time period studied. Interestingly, levels of ELN mRNA were relatively low at early time points (E12.5), but increased significantly by P2. Thus, we identified changes in the spatial and temporal localization of the primary ECM of the developing ventricle. This characterization can serve as a blueprint for fabrication techniques, which we illustrate by using multiphoton excitation photochemistry to create a synthetic scaffold based on COLIV organization at P2. Similarly, fabricated scaffolds generated using ECM components, could be utilized for ventricular repair.

Curcumin, a potent anti-inflammatory and antioxidant agent, modulates peroxisome proliferator-activated receptor-γ signaling, a key molecule in the etiology of bronchopulmonary dysplasia (BPD). We have previously shown curcumin's acute protection against neonatal hyperoxia-induced lung injury. However, its longer-term protection against BPD is not known. Hypothesizing that concurrent treatment with curcumin protects the developing lung against hyperoxia-induced lung injury long-term, we determined if curcumin protects against hyperoxic neonatal rat lung injury for the first 5 days of life, as determined at postnatal day (PND) 21. One-day-old rat pups were exposed to either 21 or 95% O₂ for 5 days with or without curcumin treatment (5 mg/kg) administered intraperitoneally one time daily, following which the pups grew up to PND21 in room air. At PND21 lung development was determined, including gross and cellular structural and functional effects, and molecular mediators of inflammatory injury. To gain mechanistic insights, embryonic day 19 fetal rat lung fibroblasts were examined for markers of apoptosis and MAP kinase activation following in vitro exposure to hyperoxia for 24 h in the presence or absence of curcumin (5 μM). Curcumin effectively blocked hyperoxia-induced lung injury based on systematic analysis of markers for lung injury (apoptosis, Bcl-2/Bax, collagen III, fibronectin, vimentin, calponin, and elastin-related genes) and lung morphology (radial alveolar count and alveolar septal thickness). Mechanistically, curcumin prevented the hyperoxia-induced increases in cleaved caspase-3 and the phosphorylation of Erk1/2. Molecular effects of curcumin, both structural and cytoprotective, suggest that its actions against hyperoxia-induced lung injury are mediated via Erk1/2 activation and that it is a potential intervention against BPD.

Among elastic system fibers, oxytalan fibers are known as a ubiquitous component of the periodontal ligament, but the localization and role of elastin-containing fibers, i.e., elastic and elaunin fibers, has yet to be clarified. In this study, we immunohistochemically investigated the localization of elastin and fibrillin, major proteins of elastin-containing fibers in the periodontal ligament of rat lower first molars. At the light microscope level, distribution of elastin-positive fibers was not uniform but often concentrated in the vicinity of blood vessels in the apical region of the ligament. In contrast, fibrillin-positive fibers were more widely distributed throughout the ligament, and the pattern of their distribution was comparable to the reported distribution of oxytalan fibers. At the ultrastructural level, assemblies or bundles of abundant fibrillin-containing microfibrils were intermingled with a small amount of elastin. This observation indicated that elastin-positive fibers observed under the light microscope were elaunin fibers. No mature elastic fibers, however, were found in the ligament. These results show that the major components of elastic system fibers in the periodontal ligament of the rat mandibular first molar were oxytalan and elaunin fibers, suggesting that the elastic system fibers play a role in the mechanical protection of the vascular system.

BACKGROUND/PURPOSE: Extracellular matrix proteins are implicated in regulating cell proliferation and differentiation. The authors systematically analysed the expression of elastin; collagen types I, III, IV; laminin; and fibronectin during mouse detrusor muscle development, a period during which downregulation of detrusor proliferation and increasing smooth muscle differentiation is known to occur. METHODS: Embryonic days 14 (E14) and 18 (E18), and postnatal day 1 (D1) and week 6 (6wk) were examined, a period spanning the inception of the bladder to postnatal maturity. Immunohistochemistry of whole bladders was used to immunolocalise protein expression, and Western blot of dissected detrusor layers was used to semiquantify soluble protein expression. RESULTS: All proteins were detected at all 4 stages. Statistically significant increases were documented for elastin (E14 to 6wk), collagen type I (E18 to 6wk), collagen type III (D1 to 6wk) and laminin (E14 to 6wk). Fibronectin levels were relatively high up to D1, after which levels declined significantly. Collagen type IV levels decreased significantly (E18 to 6wk). CONCLUSIONS: The authors postulate that changing levels of laminin and fibronectin have opposing effects on the transition from proliferating primitive mesenchymal cells to differentiated detrusor muscle. Furthermore, changes in collagen type III and elastin may be important for bladder compliance.