17β-estradiol inhibits Notch1 activation in murine macrophage cell line RAW 264.7.

Background: Macrophages are major effectors in regulating immune response and inflammation. The pro-inflammatory phenotype (M1) is induced by the activation of the Toll-like receptor 4 (TLR4) on the macrophage surface, which recognizes lipopolysaccharide (LPS), a component of Gram-negative bacterial wall, and by the binding of interferon-gamma (IFNγ), a cytokine released by activated T lymphocytes, to its receptor (IFNGR). Among the pathways activated by LPS/IFNγ is the Notch pathway, which promotes the M1 phenotype.

ErbB2-NOTCH1 axis controls autophagy in cardiac cells.

Although the epidermal growth factor receptor 2 (ErbB2) and Notch1 signaling pathways have both significant roles in regulating cardiac biology, their interplay in the heart remains poorly investigated. Here, we present evidence of a crosstalk between ErbB2 and Notch1 in cardiac cells, with effects on autophagy and proliferation. Overexpression of ErbB2 in H9c2 cardiomyoblasts induced Notch1 activation in a post-transcriptional, p38-dependent manner, while ErbB2 inhibition with the specific inhibitor, lapatinib, reduced Notch1 activation.

Hypertensive Pressure Mechanosensing Alone Triggers Lipid Droplet Accumulation and Transdifferentiation of Vascular Smooth Muscle Cells to Foam Cells.

Arterial Vascular smooth muscle cells (VSMCs) play a central role in the onset and progression of atherosclerosis. Upon exposure to pathological stimuli, they can take on alternative phenotypes that, among others, have been described as macrophage like, or foam cells. VSMC foam cells make up >50% of all arterial foam cells and have been suggested to retain an even higher proportion of the cell stored lipid droplets, further leading to apoptosis, secondary necrosis, and an inflammatory response.