Distinct B cell populations, designated regulatory B (B) cells, are known to restrain immune responses associated with autoimmune diseases. Additionally, obesity is known to induce local inflammation within adipose tissue that contributes to systemic metabolic abnormalities, but the underlying mechanisms that modulate adipose inflammation remain poorly understood. We identified B cells that produce interleukin-10 constitutively within adipose tissue. B cell-specific Il10 deletion enhanced adipose inflammation and insulin resistance in diet-induced obese mice, whereas adoptive transfer of adipose tissue B cells ameliorated those effects. Adipose environmental factors, including CXCL12 and free fatty acids, support B cell function, and B cell fraction and function were reduced in adipose tissue from obese mice and humans. Our findings indicate that adipose tissue B cells are a naturally occurring regulatory B cell subset that maintains homeostasis within adipose tissue and that B cell dysfunction contributes pivotally to the progression of adipose tissue inflammation in obesity.

The present study was designed to investigate the rewarding effect, G-protein activation and dopamine (DA) release following partial sciatic nerve ligation in the rat. Here we show for the first time that morphine failed to produce a place preference in rats with nerve injury. Various studies provide arguments to support that the mesolimbic dopaminergic system, which projects from the ventral tegmental area (VTA) to the nucleus accumbens (N.Acc), is critical of the motivational effects of opioids. In the present study, there were no significant differences between sham-operated and sciatic nerve-ligated rats in the increases in guanosine-5¢-o-(3-

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 β-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.

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.lncFAOis induced late after lipopolysaccharide (LPS) stimulation of cultured macrophages and in Ly6Chimonocyte-derived macrophages in damaged tissue during the resolution and reparative phases. We found thatlncFAOdirectly interacts with the HADHB subunit of mitochondrial trifunctional protein and activates FAO.lncFAOdeletion 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,lncFAOacts as a node of immunometabolic control in macrophages during the resolution and repair phases of inflammation.

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