TNF and obesity due to melanocortin 4 receptor deficiency: The use of prolonged exposure of microglia to three potent pro-inflammatory stimulants, i.e., LPS, PA, and TNFα, showed that PA can be metabolized to LDs, which, taking into account many months of endotoxemia and systemic inflammation accompanying obesity and ME, may ultimately lead to neurodegeneration, similarly to the LPS-induced increase in ceramides.