Adipose tissue fibrosis in human cancer cachexia: the role of TGF beta pathway
BMC CANCER
Authors: Alves, Michele Joana; Figueredo, Raquel Galvao; Azevedo, Flavia Figueiredo; Cavallaro, Diego Alexandre; Pinto Neto, Nelson Inacio; Carola Lima, Joanna Darck; Matos-Neto, Emidio; Radloff, Katrin; Riccardi, Daniela Mendes; Camargo, Rodolfo Gonzalez; Martins De Alcantara, Paulo Sergio; Otoch, Jose Pinhata; Batista Junior, Miguel Luiz; Seelaender, Marilia
Abstract
Background: Cancer cachexia is a multifactorial syndrome that dramatically decreases survival. Loss of white adipose tissue (WAT) is one of the key characteristics of cachexia. WAT wasting is paralleled by microarchitectural remodeling in cachectic cancer patients. Fibrosis results from uncontrolled ECM synthesis, a process in which, transforming growth factor-beta (TGF beta) plays a pivotal role. So far, the mechanisms involved in adipose tissue (AT) re-arrangement, and the role of TGF beta in inducing AT remodeling in weight-losing cancer patients are poorly understood. This study examined the modulation of ECM components mediated by TGF beta pathway in fibrotic AT obtained from cachectic gastrointestinal cancer patients. Methods: After signing the informed consent form, patients were enrolled into the following groups: cancer cachexia (CC, n = 21), weight-stable cancer (WSC, n = 17), and control (n = 21). The total amount of collagen and elastic fibers in the subcutaneous AT was assessed by histological analysis and by immunohistochemistry. TGF beta isoforms expression was analyzed by Multiplex assay and by immunohistochemistry. Alpha-smooth muscle actin (aSMA), fibroblast-specific protein (FSP1), Smad3 and 4 were quantified by qPCR and/or by immunohistochemistry. Interleukin (IL) 2, IL5, IL8, IL13 and IL17 content, cytokines known to be associated with fibrosis, was measured by Multiplex assay. Results: There was an accumulation of collagen and elastic fibers in the AT of CC, as compared with WSC and controls. Collagens type I, III, VI, and fibronectin expression was enhanced in the tissue of CC, compared with both WSC and control. The pronounced expression of aSMA in the surrounding of adipocytes, and the increased mRNA content for FSP1 (20-fold) indicate the presence of activated myofibroblasts; particularly in CC. TGF beta 1 and TGF beta 3 levels were up-regulated by cachexia in AT, as well in the isolated adipocytes. Smad3 and Smad4 labeling was found to be more evident in the fibrotic areas of CC adipose tissue. Conclusions: Cancer cachexia promotes the development of AT fibrosis, in association with altered TGF beta signaling, compromising AT organization and function.
Dual roles of calpain in facilitating Coxsackievirus B3 replication and prompting inflammation in acute myocarditis
INTERNATIONAL JOURNAL OF CARDIOLOGY
Authors: Li, Minghui; Su, Yangang; Yu, Yong; Yu, Ying; Wang, Xinggang; Zou, Yunzeng; Ge, Junbo; Chen, Ruizhen
Abstract
Background: Viral myocarditis (VMC) treatment has long been lacking of effective methods. Our former studies indicated roles of calpain in VMC pathogenesis. This study aimed at verifying the potential of calpain in Coxsackievirus B3 (CVB3)-induced myocarditis treatment. Methods: A transgenic mouse overexpressing the endogenous calpain inhibitor, calpastatin, was introduced in the study. VMC mouse model was established via intraperitoneal injection of CVB3 in transgenic and wild mouse respectively. Myocardial injury was assayed histologically (HE staining and pathology grading) and serologically (myocardial damage markers of CK-MB and cTnI). CVB3 replication was observed in vivo and in vitro via the capsid protein VP1 detection or virus titration. Inflammation/fibrotic factors of MPO, perforin, IFN gamma, IL17, Smad3 and MMP2 were evaluated using western blot or immunohistology stain. Role of calpain in regulating fibroblast migration was studied in scratch assays. Results: Calpastatin overexpression ameliorated myocardial injury induced by CVB3 infection significantly in transgenic mouse indicated by reduced peripheral CK-MB and cTnI levels and improved histology injury. Comparing with CVB3-infected wild type mouse, the transgenic mouse heart tissue carried lower virus load. The inflammation factors of MPO, perforin, IFN gamma and IL17 were down-regulated accompanied with fibrotic agents of Smad3 and MMP2 inhibition. And calpain participated in the migration of fibroblasts in vitro, which further proves its role in regulating fibrosis. Conclusion: Calpain plays dual roles of facilitating CVB3 replication and inflammation promotion. Calpain inhibition in CVB3-induced myocarditis showed significant treatment effect. Calpain might be a novel target for VMC treatment in clinical practices. (C) 2016 Published by Elsevier Ireland Ltd.