Bellaye, P.-S. | Search bioRxiv

bioRxiv2021

Procollagen C-Proteinase Enhancer 1 (PCPE-1) is a marker of myocardial fibrosis and impaired cardiac function in a murine model of pressure overload

(1) AimsProcollagen C-proteinase enhancer 1 (PCPE-1) is an extracellular matrix protein and a major regulator of fibrillar collagen biosynthesis. Previous work has shown that its abundance is often increased in the context of tissue repair and fibrosis. The present study was designed to evaluate its potential as a biomarker of myocardial interstitial fibrosis (MIF), a well-established pathogenic pathway leading to heart failure. (2) Methods and ResultsCardiac fibrosis was induced in rats using an optimized model of chronic pressure overload triggered by angiotensin II and N{omega}-nitro-L-arginine methyl ester (L-NAME). All treated animals suffered from heart hypertrophy and the increase in heart collagen volume fraction (CVF), evidenced by histology and 68Ga-Collagelin uptake, confirmed the development of cardiac fibrosis. Functional analysis by simultaneous PET-MRI further showed that our model closely reflected the pathological features seen in human MIF, including left ventricle thickening and diastolic dysfunction associated with decreased ejection fraction. PCPE-1 mRNA and protein levels were augmented by factors of 3.4 and 6.1 respectively in the heart tissue of treated rats. Moreover, protein abundance was well-correlated with CVF (r=0.92, p<0.0001) and PCPE-1 immuno-detection mainly localized the protein to fibrotic areas. Finally, PCPE-1 plasma levels measured by ELISA were increased in fibrotic rats compared to controls. (3) ConclusionTogether, our findings demonstrate that PCPE-1 levels in the heart and circulation tightly reflect the cardiac fibrosis status and heart function impairment in rats and suggest that it could be a very useful marker to monitor human heart diseases leading to fibrosis.

physiology↗

bioRxiv2019

FK506-binding protein 13 expression is upregulated in interstitial lung disease and correlated with clinical severity: a potentially protective role.

Pulmonary fibrosis is a progressive lung disease characterized by myofibroblast accumulation and excessive extracellular matrix deposition. Endoplasmic reticulum (ER) stress initiates the unfolded protein response (UPR), a cellular stress response pathway that has been implicated in both inflammatory and fibrotic processes. Here, we sought to investigate the role of the 13 kDa FK506-binding protein (FKBP13), an ER stress-inducible molecular chaperone, in various forms of pulmonary fibrosis. We first characterized the gene and protein expression of FKBP13 in lung biopsy samples from 24 patients with idiopathic pulmonary fibrosis (IPF) and 17 control subjects. FKBP13 expression was found to be elevated in the fibrotic regions of IPF lung tissues, and within this cohort, was correlated with declining forced vital capacity and dyspnea severity. FKBP13 expression was also increased in lung biopsies of patients with hypersensitivity pneumonitis, rheumatoid arthritis, and sarcoidosis-associated interstitial lung disease. We next evaluated the role of this protein using FKBP13-/- mice in a bleomycin model of pulmonary fibrosis. Animals were assessed for lung function and histopathology at different stages of lung injury including the inflammatory (Day 7), fibrotic (Day 21) and resolution (Day 50) phase. FKBP13-/- mice showed increased infiltration of inflammatory cells and cytokines at Day 7, increased lung elastance and fibrosis at Day 21, and impaired resolution of fibrosis at Day 50. These changes were associated with an increased number of cells that stained positive for TUNEL and cleaved caspase 3 in the FKBP13-/- lungs, indicating a heightened cellular sensitivity to bleomycin. Our findings suggest that FKBP13 is a potential biomarker for severity or progression of interstitial lung diseases, and that it has a biologically relevant role in protecting mice against bleomycin-induced injury, inflammation and fibrosis.

pathology↗