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Kurland, I. J.

Publications and source records attributed to Kurland, I. J..

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Neuronal glucose metabolism sets cholinergic tone and controls thermo-regulated signaling at the neuromuscular junction

Cholinergic and sympathetic counter-regulatory networks control numerous physiologic functions including learning/memory/cognition, stress responsiveness, blood pressure, heart rate and energy balance. As neurons primarily utilize glucose as their primary metabolic energy source, we generated mice with increased glycolysis in cholinergic neurons by specific deletion of the fructose-2,6-phosphatase protein TIGAR. Steady-state and stable isotope flux analyses demonstrated increased rates of glycolysis, acetyl-CoA production, acetylcholine levels and density of neuromuscular synaptic junction clusters with enhanced acetylcholine release. The increase in cholinergic signaling reduced blood pressure and heart rate with a remarkable resistance to cold-induced hypothermia. These data directly demonstrate that increased cholinergic signaling through the modulation of glycolysis has several metabolic benefits particularly to increase energy expenditure and heat production upon cold exposure. HighlightsO_LIDeficiency of a negative regulator of glycolysis (TIGAR) in cholinergic neurons increases the biosynthesis and content of the neurotransmitter acetylcholine. C_LIO_LIIncreased cholinergic tone reduces blood pressure and heart rate while enhancing signaling at neuromuscular junction. C_LIO_LIUpregulation of neuromuscular junction activation provides protection against the paralytic curare and cold-induced hypothermia. C_LIO_LIModulation of cholinergic neuron glycolysis may provide a novel therapeutic approach for treatment of diseases stemming from reduced acetylcholine signaling such as myasthenia gravis and sarcopenic pre-synaptic dysfunction. C_LI

cell biology

Radiation Exposure of the Base of the Heart Accelerates Coronary Atherosclerosis

Clinical studies have identified cardiac exposure as an independent predictor for cardiovascular mortality in patients treated with radiation therapy (RT) for thoracic malignancies. Although the mechanisms are not completely understood, the available evidence indicate that direct injury to the coronary arteries endothelium is implicated. In these studies we tested the hypothesis that different areas of the heart are more sensitive to the effects of RT on the formation of atherosclerotic plaque in apolipoprotein E deficient (ApoE-/-) mice, a well validated model of atherosclerosis. MethodsApoE-/- mice on a high fat diet (HFD) received 16Gy cardiac irradiation targeted to the whole or partial (apical or basal) region of the heart at 9 weeks or 16 weeks of age. Atherosclerotic lesions and inflammatory changes in the hearts as compared to control unirradiated mice were assessed eight weeks following radiation. ResultsAfter either basal or whole heart RT at 9 weeks of age the number of subendocardial atherosclerotic lesions at the heart base was higher as compared to unirradiated mice. Irradiation of the apex did not increase the number of subendocardial atherosclerotic lesions in any region. After basal RT at 16 weeks of age the number of coronary and subendocardial atherosclerotic lesions was higher as compared to controls. Neither apical or whole heart RT had an impact on the development or acceleration of lesions in the basal region of the hearts of 16 week old mice, thus demonstrating the adverse impact of basal irradiation. Infiltration of inflammatory cells (CD45+ and CD3+) and enhanced expression of endothelial adhesion molecules (CD31), were differentially and locally regulated based upon the site of irradiation. In support of a role of eicosanoid mediators for base or whole heart atherogenic irradiation effects, apex irradiation eicosanoid mediators are not clearly atherogenic, in contrast to eicosanoid mediators detected in serum after base heart irradiation. These results indicate that the base of the heart is significantly more prone to the development of atherosclerotic lesions in the coronary arteries post-RT. ConclusionOur results indicate that the base of the heart is more susuceptible to development of RT-induced atherosclerotic lesions and therefore avoidance from RT direct exposure to this area may reduce the risk for atherosclerotic disease in patients undergoing RT.

cancer biology