Objective: Hypoglycemia is associated with a variety of adverse behaviors including fatigue, confusion and social withdrawal. While these clinical symptoms are well characterized, the mechanism of their cause is not understood. Here we investigated how insulin-induced hypoglycemia causes social withdrawal.
View Article and Find Full Text PDFBackground: Macrophages (MPhis) utilize macropinocytosis to integrate immune and metabolic signals in order to initiate an effective immune response. Diabetes is characterized by metabolic abnormalities and altered immune function. Here we examine the influence of diabetes on macropinocytosis in primary mouse macrophages and in an in vitro diabetes model.
View Article and Find Full Text PDFThe incidence of type 2 diabetes (T2D) is rapidly expanding. Some of the more obvious pathologies associated with it include: defective glucose metabolism, obesity, cardiovascular disease and an inability to mount an effective immune response to infection by certain pathogenic organisms, leading to sepsis and death. A common tie linking these seemingly disparate complications is chronic inflammation.
View Article and Find Full Text PDFMacrophages are capable of assuming numerous phenotypes in order to adapt to endogenous and exogenous challenges but many of the factors that regulate this process are still unknown. We report that Ca(2+)/calmodulin-dependent kinase kinase alpha (CaMKKalpha) is expressed in human monocytic cells and demonstrate that its inhibition blocks type-II monocytic cell activation and promotes classical activation. Affinity chromatography with paramagnetic beads isolated an approximately 50 kDa protein from nuclear lysates of U937 human monocytic cells activated with phorbol-12-myristate-13-acetate (PMA).
View Article and Find Full Text PDFType 2 diabetes (T2D) is associated with accelerated atherosclerosis, which accounts for approximately 75% of all diabetes-related deaths. Here we investigate the link between diabetes and macrophage cholesteryl ester accumulation. When diabetic (db/db) mice are given cholesteryl ester intraperitoneally (IP), peritoneal macrophages (PerMPhis) recovered from these animals showed a 58% increase in intracellular cholesteryl ester accumulation over PerMPhis from heterozygote control (db/+) mice.
View Article and Find Full Text PDFChronic elevation of proinflammatory markers in type 2 diabetes (T2D) is well defined, but the role of anti-inflammatory cytokines in T2D is less clear. In this study, we report that normal IL-4-dependent elaboration of IL-1 receptor antagonist (IL-1RA) requires IRS-2-mediated PI3K activity in primary macrophages. We also show that macrophages isolated from obese/diabetic db/db mice have impaired IRS-2-mediated PI3K activity and constitutively overexpress suppressor of cytokine signaling (SOCS)-3, which impairs an important IL-4 anti-inflammatory function.
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