Association of Cardiac Galectin-3 Expression, Myocarditis, and Fibrosis in Chronic Chagas Disease Cardiomyopathy.
Am J Pathol. 2017 Mar 16;:
Authors: de Freitas Souza BS, Silva DN, Carvalho RH, de Almeida Sampaio GL, Paredes BD, Aragão França L, Azevedo CM, Vasconcelos JF, Meira CS, Neto PC, Macambira SG, da Silva KN, Allahdadi KJ, Tavora F, de Souza Neto JD, Dos Santos RR, Soares MB
Chronic Chagas disease cardiomyopathy, caused by Trypanosoma cruzi infection, is a major cause of heart failure in Latin America. Galectin-3 (Gal-3) has been linked to cardiac remodeling and poor prognosis in heart failure of different etiologies. Herein, we investigated the involvement of Gal-3 in the disease pathogenesis and its role as a target for disease intervention. Gal-3 expression in mouse hearts was evaluated during T. cruzi infection by confocal microscopy and flow cytometry analysis, showing a high expression in macrophages, T cells, and fibroblasts. In vitro studies using Gal-3 knockdown in cardiac fibroblasts demonstrated that Gal-3 regulates cell survival, proliferation, and type I collagen synthesis. In vivo blockade of Gal-3 with N-acetyl-d-lactosamine in T. cruzi-infected mice led to a significant reduction of cardiac fibrosis and inflammation in the heart. Moreover, a modulation in the expression of proinflammatory genes in the heart was observed. Finally, histological analysis in human heart samples obtained from subjects with Chagas disease who underwent heart transplantation showed the expression of Gal-3 in areas of inflammation, similar to the mouse model. Our results indicate that Gal-3 plays a role in the pathogenesis of experimental chronic Chagas disease, favoring inflammation and fibrogenesis. Moreover, by demonstrating Gal-3 expression in human hearts, our finding reinforces that this protein could be a novel target for drug development for Chagas cardiomyopathy.
PMID: 28322201 [PubMed - as supplied by publisher]
Complement Component C3 and Complement Factor B Promote Growth of Cutaneous Squamous Cell Carcinoma.
Am J Pathol. 2017 Mar 16;:
Authors: Riihilä P, Nissinen L, Farshchian M, Kallajoki M, Kivisaari A, Meri S, Grénman R, Peltonen S, Peltonen J, Pihlajaniemi T, Heljasvaara R, Kähäri VM
Cutaneous squamous cell carcinoma (cSCC) is one of the most common metastatic skin cancers with increasing incidence. We examined the roles of complement component C3 and complement factor B (CFB) in the growth of cSCC. Analysis of cSCC cell lines (n = 8) and normal human epidermal keratinocytes (n = 11) with real-time quantitative PCR and Western blotting revealed up-regulation of C3 and CFB expression in cSCC cells. Immunohistochemical staining revealed stronger tumor cell-specific labeling for C3 and CFB in invasive cSCCs (n = 71) and recessive dystrophic epidermolysis bullosa-associated cSCCs (n = 11) than in cSCC in situ (n = 69), actinic keratoses (n = 63), and normal skin (n = 5). Significant up-regulation of C3 and CFB mRNA expression was noted in chemically induced mouse skin cSCCs, compared to benign papillomas, hyperplastic skin, and normal skin. The expression of C3 and CFB was higher in aggressive Ha-ras-transformed cell line (RT3) than in less tumorigenic HaCaT cell lines (HaCaT, A5, II-4). Knockdown of C3 and CFB expression inhibited migration and proliferation of cSCC cells and resulted in potent inhibition of extracellular signal-regulated kinase 1/2 activation. Knockdown of C3 and CFB markedly inhibited growth of human cSCC xenograft tumors in vivo. These results provide evidence for the roles of C3 and CFB in the development of cSCC and identify them as biomarkers and potential therapeutic targets in this metastatic skin cancer.
PMID: 28322200 [PubMed - as supplied by publisher]
Adrenomedullin Suppresses Vascular Endothelial Growth Factor-Induced Vascular Hyperpermeability and Inflammation in Retinopathy.
Am J Pathol. 2017 Mar 16;:
Authors: Imai A, Toriyama Y, Iesato Y, Hirabayashi K, Sakurai T, Kamiyoshi A, Ichikawa-Shindo Y, Kawate H, Tanaka M, Liu T, Xian X, Zhai L, Dai K, Tanimura K, Liu T, Cui N, Yamauchi A, Murata T, Shindo T
Diabetic macular edema (DME) is caused by blood-retinal barrier breakdown associated with retinal vascular hyperpermeability and inflammation, and it is the major cause of visual dysfunction in diabetic retinopathy. Adrenomedullin (ADM) is an endogenous peptide first identified as a strong vasodilator. ADM is expressed in the eyes and is up-regulated in various eye diseases, although the pathophysiological significance is largely unknown. We investigated the effect of ADM on DME. In Kimba mice, which overexpress human vascular endothelial growth factor in their retinas, the capillary dropout, vascular leakage, and vascular fragility characteristic of diabetic retinopathy were observed, and these changes were accompanied by retinal inflammation. Intravitreal or systemic administration of ADM to Kimba mice ameliorated both the capillary dropout and vascular leakage. Evaluation of the transendothelial electrical resistance and fluorescein isothiocyanate-dextran permeability of an endothelial cell monolayer using TR-iBRB retinal capillary endothelial cells revealed that vascular endothelial growth factor enhanced vascular permeability but that co-administration of ADM suppressed the effect, in part by enhancing tight junction formation between endothelial cells. In addition, a comprehensive PCR array analysis showed that ADM administration suppressed various molecules related to inflammation and NF-κB signaling within retinas. From these results, we suggest that by exerting inhibitory effects on retinal inflammation, vascular permeability, and blood-retinal barrier breakdown, ADM could serve as a novel therapeutic agent for the treatment of DME.
PMID: 28322199 [PubMed - as supplied by publisher]
Carbon Monoxide-Releasing Molecule-401 Suppresses Polymorphonuclear Leukocyte Migratory Potential by Modulating F-Actin Dynamics.
Am J Pathol. 2017 Mar 17;:
Authors: Inoue K, Patterson EK, Capretta A, Lawendy AR, Fraser DD, Cepinskas G
Carbon monoxide-releasing molecules (CORMs) suppress inflammation by reducing polymorphonuclear leukocyte (PMN) recruitment to the affected organs. We investigated modulation of PMN-endothelial cell adhesive interactions by water-soluble CORM-401 using an experimental model of endotoxemia in vitro. Human umbilical vein endothelial cells grown on laminar-flow perfusion channels were stimulated with 1 μg/mL lipopolysaccharide for 6 hours and perfused with 100 μmol/L CORM-401 (or inactive compound iCORM-401)-pretreated PMN for 5 minutes in the presence of 1.0 dyn/cm(2) shear stress. Human umbilical vein endothelial cell:PMN co-cultures were perfused for additional 15 minutes with PMN-free medium containing CORM-401/inactive CORM-401. The experiments were videorecorded (phase-contrast microscopy), and PMN adhesion/migration were assessed off-line. In parallel, CORM-401-dependent modulation of PMN chemotaxis, F-actin expression/distribution, and actin-regulating pathways [eg, p21-activated protein kinases (PAK1/2) and mitogen-activated protein kinase (MAPK) activation] were assessed in response to N-formyl-methionyl-leucyl-phenylalanine (fMLP) stimulation. Pretreating PMN with CORM-401 did not suppress PMN adhesion, but significantly reduced PMN transendothelial migration (P < 0.0001) and fMLP-induced PMN chemotaxis (ie, migration directionality and velocity). These changes were associated with CORM-401-dependent suppression of F-actin levels/cellular distribution and fMLP-induced phosphorylation of PAK1/2 and extracellular signal-regulated kinase/C-Jun N-terminal kinase MAPK (P < 0.05). CORM-401 had no effect on p38 MAPK activation. In summary, this study demonstrates, for the first time, CORM-401-dependent suppression of neutrophil migratory potential associated with modulation of PAK1/2 and extracellular signal-regulated kinase/C-Jun N-terminal kinase MAPK signaling and intracellular F-actin dynamics.
PMID: 28320610 [PubMed - as supplied by publisher]