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Zeboudj, L.

Publications and source records attributed to Zeboudj, L..

2 recordsLinked to original sources

Inhibition of Bruton’s tyrosine kinase reduces NF-kB and NLRP3 inflammasome activity preventing insulin resistance and microvascular disease

Activation of inflammatory pathways in myeloid cells initiates insulin resistance leading to the development of type-2 diabetes and microvascular disease. Currently, there are no therapies available that target inflammation in T2D or microvascular disease. In the present study we investigate if Brutons tyrosine kinase (BTK) may represent a novel therapeutic target using the FDA approved medication ibrutinib. Ibrutinib treatment protected high fat diet (HFD)-fed mice from developing insulin resistance and improved glycaemic control by restoring signalling through IRS-1/Akt/GSK-3{beta} pathway. These improvements were independent of body weight and calorific intake. Treatment with ibrutinib to mice fed a HFD reduced NF-{kappa}B and reduced inflammatory gene expression, this was coupled with decreased activation of the NLRP3 inflammasome in the diabetic liver and kidney. Ibrutinib treatment also protected mice from the development of diabetic nephropathy by reducing monocyte/macrophage infiltration due to reduced expression of the pro-inflammatory chemokines. Ibrutinib treatment to human monocyte derived macrophages significantly reduced pro-inflammatory gene expression and a significant reduction in IL-1{beta} and TNF after LPS stimulation. In the present study we provide proof of concept evidence that BTK is a novel therapeutic target for the treatment of T2D and ibrutinib may be a candidate for drug repurposing in T2D.

systems biology

Efferocytosis perpetuates substance accumulation inside macrophage populations

In both cells and animals, cannibalism can transfer harmful substances from the consumed to the consumer. Macrophages are immune cells that consume their own dead via a process called cannibalistic efferocytosis. Macrophages that contain harmful substances are found at sites of chronic inflammation, yet the role of cannibalism in this context remains unexplored. Here we take mathematical and experimental approaches to study the relationship between cannibalistic efferocytosis and substance accumulation in macrophages. Through mathematical modelling, we deduce that substances which transfer between individuals through cannibalism will concentrate inside the population via a coalescence process. This prediction was confirmed for macrophage populations inside a closed system. We used image analysis of whole slide photomicrographs to measure both latex microbead and neutral lipid accumulation inside murine bone marrow-derived macrophages (104 - 105 cells) following their stimulation into an inflammatory state ex vivo. While the total number of phagocytosed beads remained constant, cell death reduced cell numbers and efferocytosis concentrated the beads among the surviving macrophages. Since lipids are also conserved during efferocytosis, these cells accumulated lipid derived from the membranes of dead and consumed macrophages (becoming macrophage foam cells). Consequently, enhanced macrophage cell death increased the rate and extent foam cell formation. Our results demonstrate that cannibalistic efferocytosis perpetuates exogenous (e.g. beads) and endogenous (e.g. lipids) substance accumulation inside macrophage populations. As such, cannibalism has similar detrimental consequences in both cells and animals.

immunology