Epithelial-interleukin-1 inhibits collagen formation by airway fibroblasts: Implications for asthma
SCIENTIFIC REPORTS
Authors: Osei, Emmanuel T.; Mostaco-Guidolin, Leila B.; Hsieh, Aileen; Warner, Stephanie M.; AL-Fouadi, May; Wang, Mary; Cole, Darren J.; Maksym, Geoffrey N.; Hallstrand, Teal S.; Timens, Wim; Brandsma, Corry-Anke; Heijink, Irene H.; Hackett, Tillie-Louise
Abstract
In asthma, the airway epithelium has an impaired capacity to differentiate and plays a key role in the development of airway inflammation and remodeling through mediator release. The study objective was to investigate the release of (IL)-1 family members from primary airway epithelial-cells during differentiation, and how they affect primary airway fibroblast (PAF)-induced inflammation, extracellular matrix (ECM) production, and collagen I remodeling. The release of IL-1 alpha/beta and IL-33 during airway epithelial differentiation was assessed over 20-days using air-liquid interface cultures. The effect of IL-1 family cytokines on airway fibroblasts grown on collagen-coated well-plates and 3-dimensional collagen gels was assessed by measurement of inflammatory mediators and ECM proteins by ELISA and western blot, as well as collagen fiber formation using non-linear optical microscopy after 24-hours. The production of IL-1 alpha is elevated in undifferentiated asthmatic-PAECs compared to controls. IL-1 alpha/beta induced fibroblast pro-inflammatory responses (CXCL8/IL-8, IL-6, TSLP, GM-CSF) and suppressed ECM-production (collagen, fibronectin, periostin) and the cell's ability to repair and remodel fibrillar collagen I via LOX, LOXL1 and LOXL2 activity, as confirmed by inhibition with beta-aminopropionitrile. These data support a role for epithelial-derived-IL-1 in the dysregulated repair of the asthmatic-EMTU and provides new insights into the contribution of airway fibroblasts in inflammation and airway remodeling in asthma.
LOX-related collagen crosslink changes act as an initiator of bone fragility in a ZDF rats model
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
Authors: Xiao, Xun; Ren, Jie; Chen, Jun; Liu, Zhaohui; Tian, Ye; Nabar, Neel R.; Wang, Min; Hao, Liang
Abstract
Diabetes mellitus type 2 (DM2) results in bone abnormalities that manifest as increased bone fragility. Bone consists of two phases, the mineral phase and the matrix phase, and disorders in both are seen in DM2. However, the phase in which DM2 mediated bone fragility is initiated is still unknown. In this study, a male Zucker diabetic fatty (fa/fa) (ZDF) rat model was used to investigate the underlying mechanism initiating DM2 mediated bone fragility. The fracture surface morphology, pre- and post-yield bone mechanical behavior, insoluble collagen volume, lysyl oxidase family (LOX) enzyme levels and correlation analysis was performed to determine the relationship between insoluble collagen and post yield behavior. Four weeks after the induction of diabetes, insoluble collagen was decreased in only the matrix phase in diabetic rats. Consistently, mechanical testing of the bone showed changes only in post yield behavior. Diabetic rats also had decreased levels of enzymes involved in insoluble collagen formation (LOX and LOXL1 families). Correlation analysis demonstrated that insoluble collagen was a positive regressor of post-yield displacement (R = 0.894, P < 0.001) and post-yield energy (R = 0.918, P < 0.001). Together, these findings suggest that bone fragility in DM2 is initiated in the matrix phase and that the LOX family may play a critical part in the pathogenesis of DM2 mediated bone fragility. (C) 2017 Elsevier Inc. All rights reserved.