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• Adipokines are expressed in SSc organ involvement and lung tissue affected by IPF. • Adiponectin, an adipokine with anti-fibrotic effects, is reduced in IPF. • Adiponectin expression is also reduced in SSc related gastritis. • Visfatin and resistin were associated with inflammation in SSc and IPF. The immunomodulatory properties of adipokines have previously been reported in autoimmune disorders. Less is known about the role of adipokines in systemic sclerosis (SSc). Lung and gastrointestinal tract are frequently involved in SSc; therefore, these organs were analyzed for adipokine expression as well as pulmonary samples of patients suffering from idiopathic pulmonary fibrosis (IPF) as comparison. Gastric samples (antrum, corpus) of SSc were analyzed immunohistochemically for adiponectin, resistin and visfatin compared with non-SSc related gastritis. Inflammatory cells were quantified in gastric samples and correlated with adipokine expression. Lung samples of SSc, IPF and healthy controls were also analyzed. Protein levels of lung tissue lysates and bronchoalveolar lavages (BAL) in minor fibrotic stages were measured by ELISA. Lung sections of donor parenchyma showed significantly stronger adiponectin signals as IPF and SSc (donor vs. IPF: p < 0.0001). In SSc and IPF, resistin and visfatin were increased within immune cell infiltrates, but overall no difference in expression for resistin or visfatin compared to controls was observed. In BAL and lung protein lysates of early stages of fibrosis, adiponectin and visfatin were not reduced in IPF and SSc compared to controls. In gastric samples collected by standard endoscopic gastric biopsy, adiponectin was also significantly reduced in SSc- compared to non-SSc gastritis (p = 0.049) while resistin and visfatin were comparable although deeper fibrotic layers were not included in the respective samples. Adiponectin-positive tissues showed higher amounts of CD4+ but not CD8+ T cells. Controls showed no correlation between CD4+ T cells and resistin, whereas SSc showed significantly more CD4+ T cells in resistin-negative tissues. Adipokines are expressed in gastric and lung samples of patients with SSc and in lung samples affected by IPF. Prominently, adiponectin levels were reduced in fibrotic SSc gastritic tissue as well as in IPF and SSc lung tissue. Consequently, adiponectin expression seems to be associated with fibrotic progression in the context of SSc and IPF. [ABSTRACT FROM AUTHOR]

Bleomycin is a widely accepted cancer drug but may induce life-threatening interstitial lung disease in a subset of patients. We evaluated the effect of bleomycin administration on pulmonary surfactant function and composition in rabbit lungs. In order to obtain a uniform response to bleomycin, aerosol technology was employed for bronchoalveolar delivery of 1.8 U/kg b.w. bleomycin. On days 4, 8, 16, 24, 32, and 64 after challenge, bronchoalveolar lavages were performed. Sham-aerosolized rabbits served as controls. In the early acute respiratory distress syndrome (ARDS)-like post-bleomycin period (4–16 days), marked loss of surface activity of the large surfactant aggregate (LA) fraction of surfactant was noted. In parallel, reduced percentages of LA, but only minor changes in surfactant apoproteins (SP)-A, SP-B, and SP-C, were encountered. Analysis of the surfactant lipid profile showed impressively enhanced cholesterol and significantly decreased phosphatidylglycerol (PG) levels. The relative content of dipalmitoyl-PC (DPPC) was slightly increased, and a several-fold increase within the 1-O-alkyl-2-acyl subclass of PC was observed. During the prolonged fibroproliferative period, a highly significant downregulation of SP-B and SP-C levels was observed. This was paralleled by an upregulation of the total extracellular phospholipid pool, with a far-reaching normalization of the (phospho)-lipid profile. The biophysical surfactant function never fully normalized within the 64-day observation period. In conclusion, bleomycin caused marked abnormalities of pulmonary surfactant, with the profile of changes being different between the early ARDS and the late fibrotic phase. [Copyright &y& Elsevier]