A long-term follow-up of necrobiotic xanthogranuloma with concomitant large-vessel vasculitis and heart failure with reduced ejection fraction: a case report.

Background: Necrobiotic xanthogranuloma (NXG) is a non-Langerhans cell histiocytosis and multisystem disorder. Low level of HDL cholesterol associated with a systemic inflammatory profile, which may result from the interaction of monoclonal immunoglobulin and lipoproteins, is a characteristic feature. There is no evidence of NXG-associated large-vessel vasculitis, nor are there any established treatments, although chemotherapy for comorbid multiple myeloma is most often administered. Case summary: We describe a case of a 53-year-old male with a first history of heart failure with impaired systolic function. He presented with orbital xanthomas and multiple subcutaneous nodules, and laboratory examination showed elevated levels of C-reactive protein, low HDL, and paraproteinemia. A constellation of these clinical features and pathological findings of skin biopsy led to the diagnosis of NXG. 18F-Fluorodeoxyglucose positron emission tomography (PET)/computed tomography (CT) confirmed increased uptake in the aorta and bilateral common carotid arteries. He began prednisolone treatment with reference to treatment for large-vessel vasculitis. After the treatment, C-reactive protein immediately decreased with markedly increased levels of apolipoprotein A1 (Apo-A1) and HDL. Systolic dysfunction was restored at 6-month follow-up. The patient has not experienced heart failure for 5 years after treatment, and the follow-up PET/CT demonstrated resolution of vascular inflammation. Discussion: This is the first report of NXG-associated large-vessel vasculitis. Low-dose prednisolone may benefit for NXG-associated vasculitis and cardiomyopathy. HDL, Apo-A1, and C-reactive protein levels may be useful for monitoring the activity of NXG, and PET/CT was a valuable diagnostic tool for NXG-associated vasculitis.

Novel AGL variants in a patient with glycogen storage disease type IIIb and pulmonary hypertension caused by pulmonary veno-occlusive disease: A case report.

Glycogen storage disease type III (GSD-III) is an autosomal recessive metabolic disorder caused by mutations in the AGL gene, and may develop various types of pulmonary hypertension (PH). Here, we report a case of 24-year-old man with GSD-IIIb with two novel null variants in AGL (c.2308 + 2T>C and c.3045_3048dupTACC). He developed multi-drug-resistant pulmonary veno-occlusive disease (PVOD) and was registered as a candidate for lung transplantation. No pathogenic variants were detected in previously known causative genes for pulmonary hypertension and the underlying mechanism of coincidence of two rare diseases was unknown. We discuss the association of the loss of glycogen-debranching enzyme with incident PVOD.

Cardiac macrophages prevent sudden death during heart stress.

Cardiac arrhythmias are a primary contributor to sudden cardiac death, a major unmet medical need. Because right ventricular (RV) dysfunction increases the risk for sudden cardiac death, we examined responses to RV stress in mice. Among immune cells accumulated in the RV after pressure overload-induced by pulmonary artery banding, interfering with macrophages caused sudden death from severe arrhythmias. We show that cardiac macrophages crucially maintain cardiac impulse conduction by facilitating myocardial intercellular communication through gap junctions. Amphiregulin (AREG) produced by cardiac macrophages is a key mediator that controls connexin 43 phosphorylation and translocation in cardiomyocytes. Deletion of Areg from macrophages led to disorganization of gap junctions and, in turn, lethal arrhythmias during acute stresses, including RV pressure overload and ß-adrenergic receptor stimulation. These results suggest that AREG from cardiac resident macrophages is a critical regulator of cardiac impulse conduction and may be a useful therapeutic target for the prevention of sudden death.

A long noncoding RNA regulates inflammation resolution by mouse macrophages through fatty acid oxidation activation.

Proper resolution of inflammation is vital for repair and restoration of homeostasis after tissue damage, and its dysregulation underlies various noncommunicable diseases, such as cardiovascular and metabolic diseases. Macrophages play diverse roles throughout initial inflammation, its resolution, and tissue repair. Differential metabolic reprogramming is reportedly required for induction and support of the various macrophage activation states. Here we show that a long noncoding RNA (lncRNA), lncFAO, contributes to inflammation resolution and tissue repair in mice by promoting fatty acid oxidation (FAO) in macrophages. lncFAO is induced late after lipopolysaccharide (LPS) stimulation of cultured macrophages and in Ly6Chi monocyte-derived macrophages in damaged tissue during the resolution and reparative phases. We found that lncFAO directly interacts with the HADHB subunit of mitochondrial trifunctional protein and activates FAO. lncFAO deletion impairs resolution of inflammation related to endotoxic shock and delays resolution of inflammation and tissue repair in a skin wound. These results demonstrate that by tuning mitochondrial metabolism, lncFAO acts as a node of immunometabolic control in macrophages during the resolution and repair phases of inflammation.

Errata: Can Anti-inflammatory Therapy Prevent Atrial Fibrillation in Myocardial Infarction Patients?

An error appeared in the article titled "Can Anti-inflammatory Therapy Prevent Atrial Fibrillation in Myocardial Infarction Patients?" by Yukiteru Nakayama and Katsuhito Fujiu (Vol. 59, No. 1, 3-5, 2018).The name of the last author on page 3 should be "Katsuhito Fujiu" and not "Katushito Fujiu".

A heart-brain-kidney network controls adaptation to cardiac stress through tissue macrophage activation.

Heart failure is a complex clinical syndrome characterized by insufficient cardiac function. In addition to abnormalities intrinsic to the heart, dysfunction of other organs and dysregulation of systemic factors greatly affect the development and consequences of heart failure. Here we show that the heart and kidneys function cooperatively in generating an adaptive response to cardiac pressure overload. In mice subjected to pressure overload in the heart, sympathetic nerve activation led to activation of renal collecting-duct (CD) epithelial cells. Cell-cell interactions among activated CD cells, tissue macrophages and endothelial cells within the kidney led to secretion of the cytokine CSF2, which in turn stimulated cardiac-resident Ly6Clo macrophages, which are essential for the myocardial adaptive response to pressure overload. The renal response to cardiac pressure overload was disrupted by renal sympathetic denervation, adrenergic ß2-receptor blockade or CD-cell-specific deficiency of the transcription factor KLF5. Moreover, we identified amphiregulin as an essential cardioprotective mediator produced by cardiac Ly6Clo macrophages. Our results demonstrate a dynamic interplay between the heart, brain and kidneys that is necessary for adaptation to cardiac stress, and they highlight the homeostatic functions of tissue macrophages and the sympathetic nervous system.

The H3K9 methyltransferase Setdb1 regulates TLR4-mediated inflammatory responses in macrophages.

Proinflammatory cytokine production in macrophages involves multiple regulatory mechanisms, which are affected by environmental and intrinsic stress. In particular, accumulating evidence has suggested epigenetic control of macrophage differentiation and function mainly in vitro. SET domain, bifurcated 1 (Setdb1, also known as Eset) is a histone 3 lysine 9 (H3K9)-specific methyltransferase and is essential for early development of embryos. Here we demonstrate that Setdb1 in macrophages potently suppresses Toll-like receptor 4 (TLR4)-mediated expression of proinflammatory cytokines including interleukin-6 through its methyltransferase activity. As a molecular mechanism, Setdb1-deficiency decreases the basal H3K9 methylation levels and augments TLR4-mediated NF-κB recruitment on the proximal promoter region of interleukin-6, thereby accelerating interleukin-6 promoter activity. Moreover, macrophage-specific Setdb1-knockout mice exhibit higher serum interleukin-6 concentrations in response to lipopolysaccharide challenge and are more susceptible to endotoxin shock than wildtype mice. This study provides evidence that the H3K9 methyltransferase Setdb1 is a novel epigenetic regulator of proinflammatory cytokine expression in macrophages in vitro and in vivo. Our data will shed insight into the better understanding of how the immune system reacts to a variety of conditions.

Excess Lymphangiogenesis Cooperatively Induced by Macrophages and CD4(+) T Cells Drives the Pathogenesis of Lymphedema.

Lymphedema is a debilitating progressive condition that severely restricts quality of life and is frequently observed after cancer surgery. The mechanism underlying lymphedema development remains poorly understood, and no effective pharmacological means to prevent or alleviate the ailment is currently available. Using a mouse model of lymphedema, we show here that excessive generation of immature lymphatic vessels is essential for initial edema development and that this early process is also important for later development of lymphedema pathology. We found that CD4(+) T cells interact with macrophages to promote lymphangiogenesis, and that both lymphangiogenesis and edema were greatly reduced in macrophage-depleted mice, lymphocyte-deficient Rag2(?/?) mice or CD4(+) T-cell-deficient mice. Mechanistically, T helper type 1 and T helper type 17 cells activate lesional macrophages to produce vascular endothelial growth factor-C, which promotes lymphangiogenesis, and inhibition of this mechanism suppressed not only early lymphangiogenesis, but also later development of lymphedema. Finally, we show that atorvastatin suppresses excessive lymphangiogenesis and lymphedema by inhibiting T helper type 1 and T helper type 17 cell activation. These results demonstrate that the interaction between CD4(+) T cells and macrophages is a potential therapeutic target for prevention of lymphedema after surgery.

A case of early phase dialysis associated effusive constrictive pericarditis with distinct surgical findings.

A 55-year-old male patient with a 10 year history of hemodialysis was admitted for examination of pericardial effusion. Specific echocardiography, MRI, and cardiac catheterization findings strongly suggested a diagnosis of effusive constrictive pericarditis. Pericardiectomy showed the following distinct findings. Two layers of fibrous tissue below the thickened pericardium emerged. The cardiac constriction had not been relieved until the inner layer was partially resected. We conclude that patients in dialysis associated constrictive pericarditis should undergo pericardiectomy before the adhesion between fibrous tissues becomes hard.

A case of transient 2:1 atrioventricular block, resolved by thyroxine supplementation for subclinical hypothyroidism.

A 42-year-old man was admitted to our hospital with palpitation attacks. Holter ECG showed 2:1 atrioventricular block and bradycardia with the minimum heart rate of 44 beats/min. There was a possible indication of electrophysiological study and cardiac pacemaker implantation. Laboratory data on admission revealed elevated thyrotropin level, with normal thyroxine level. To rule out functional atrioventricular block, we tried 2 weeks of the thyroxine supplementation, and Holter ECG showed improved heart rate without any atrioventricular block or long pause. We experienced that subclinical hypothyroidism caused severe bradycardia and 2:1 atrioventricular block, and that thyroxine supplementation completely improved these conditions.