Autophagy and Inflammasome Activation in Dilated Cardiomyopathy

Background: The clinical outcome of patients affected by dilated cardiomyopathy (DCM) is heterogeneous, since its pathophysiology is only partially understood. Interleukin 1 beta levels could predict the mortality and necessity of cardiac transplantation of DCM patients. Objective: To investigate mechanisms triggering sterile inflammation in dilated cardiomyopathy (DCM). Methods: Hearts explanted from 62 DCM patients were compared with 30 controls, employing immunohistochemistry, cellular and molecular biology, as well as metabolomics studies. Results: Although misfolded protein accumulation and aggresome formation characterize DCM hearts, aggresomes failed to trigger the autophagy lysosomal pathway (ALP), with consequent accumulation of both p62(SQSTM1) and dysfunctional mitochondria. In line, DCM hearts are characterized by accumulation of lipoperoxidation products and activation of both redox responsive pathways and inflammasome. Consistently with the fact that mTOR signaling may impair ALP, we observed, an increase in DCM activation, together with a reduction in the nuclear localization of Transcription Factor EB -TFEB- (a master regulator of lysosomal biogenesis). These alterations were coupled with metabolomic alterations, including accumulation of branched chain amino acids (BCAAs), known mTOR activators. Consistently, reduced levels of PP2Cm, a phosphatase that regulates the key catabolic step of BCAAs, coupled with increased levels of miR-22, a regulator of PP2Cm levels that triggers senescence, characterize DCM hearts. The same molecular defects were present in clinically relevant cells isolated from DCM hearts, but they could be reverted by downregulating miR-22. Conclusion: We identified, in human DCM, a complex series of events whose key players are miR-22, PP2Cm, BCAA, mTOR, and ALP, linking loss of proteostasis with inflammasome activation. These potential therapeutic targets deserve to be further investigated

Intracellular Function of Interleukin-1 Receptor Antagonist in Ischemic Cardiomyocytes

Background: Loss of cardiac myocytes due to apoptosis is a relevant feature of ischemic heart disease. It has been described in infarct and peri-infarct regions of the myocardium in coronary syndromes and in ischemia-linked heart remodeling. Previous studies have provided protection against ischemia-induced cardiomyocyte apoptosis by the anti-inflammatory cytokine interleukin-1 receptor-antagonist (IL-1Ra). Mitochondria triggering of caspases plays a central role in ischemia-induced apoptosis. We examined the production of IL-1Ra in the ischemic heart and, based on dual intra/extracellular function of some other interleukins, we hypothesized that IL-1Ra may also directly inhibit mitochondria-activated caspases and cardiomyocyte apoptosis. Methodology/Principal Findings: Synthesis of IL-1Ra was evidenced in the hearts explanted from patients with ischemic heart disease. In the mouse ischemic heart and in a mouse cardiomyocyte cell line exposed to long-lasting hypoxia, IL-1Ra bound and inhibited mitochondria-activated caspases, whereas inhibition of caspase activation was not observed in the heart of mice lacking IL-1Ra (Il-1ra−/−) or in siRNA to IL-1Ra-interfered cells. An impressive 6-fold increase of hypoxia-induced apoptosis was observed in cells lacking IL-1Ra. IL-1Ra down-regulated cells were not protected against caspase activation and apoptosis by knocking down of the IL-1 receptor, confirming the intracellular, receptor-independent, anti-apoptotic function of IL-1Ra. Notably, the inhibitory effect of IL-1Ra was not influenced by enduring ischemic conditions in which previously described physiologic inhibitors of apoptosis are neutralized. Conclusions/Significance: These observations point to intracellular IL-1Ra as a critical mechanism of the cell self-protection against ischemia-induced apoptosis and suggest that this cytokine plays an important role in the remodeling of heart by promoting survival of cardiomyocytes in the ischemic regions

Cardiac amyloidosis: the pathologist’s point of view

Cardiac amyloidosis is a well-known entity recently recognized as a common etiology of heart failure. This infiltrative disease is caused by the deposition of misfolded proteins within the heart. The most common types of cardiac amyloidosis result from fibrils composed of monoclonal immunoglobulin light chains or transthyretin. Clinical presentation is usually elusive, and this can result in diagnostic delay. Diagnosis can be reached with non-invasive methods, but it often requires tissue sampling with pathological analysis. It is fundamental to determine the type of protein being deposited in order to indicate the specific treatment. In this article, we review the main features of cardiac amyloidosis with a focus on different pathological presentations of this rare disorder

Tryptase-positive mast cells and CD8-positive T cells in human endometrial cancer

In this study, we correlated the number of tryptase-reactive mast cells with the number of CD8-positive T cells in human endometrial adenocarcinoma biopsy specimens by means of immunohistochemical techniques. Results have shown that CD8-positive T cell counts correlate to tryptase-positive mast cell counts and that these parameters increase in accordance with the tumor progression of human endometrial carcinoma. These data suggest that inhibition of inflammation or manipulation of inflammatory resolution pathways may be a new therapeutic approach for the treatment of endometrial adenocarcinoma

A pheochromocytoma with high adrenocorticotropic hormone and a silent lung nodule.

8Pheochromocytoma (PCC) is a challenging and life-threatening neoplasm. Herein, the authors report an interesting and unexpected solution for a clinical case concerning a patient with a PCC, who developed delayed ectopic adrenocorticotropic hormone Cushing syndrome originating from the PCC. In addition, after a misleading I-labeled metaiodobenzylguanidine single-photon emission computed tomography/computed tomography, an F-fluorodeoxyglucose positron emission tomography/computed tomography, executed to confirm the diagnosis of PCC, showed a silent pulmonary nodule that unexpectedly turned out to be a lung nocardiasis.reservedmixedBernardi, S; Grimaldi, F; Finato, N; De Marchi, S; Proclemer, A; Sabato, N; Bertolotto, M; Fabris, BBernardi, Stella; Grimaldi, F; Finato, N; De Marchi, S; Proclemer, A; Sabato, Nicoletta; Bertolotto, Michele; Fabris, Brun