Deletion of the inflammatory S100-A9/MRP14 protein does not influence survival in hSOD1 ALS mice.

Neuroinflammation is a hallmark of Amyotrophic Lateral Sclerosis (ALS) in hSOD1 mouse models where microglial cells contribute to the progressive motor neuron degenerative process. S100-A8 and S100-A9 (also known as MRP8 and MRP14, respectively) are cytoplasmic proteins expressed by inflammatory myeloid cells, including microglia and macrophages. Mainly acting as a heterodimer, S100-A8/A9, when secreted, can activate Toll-like Receptor 4 on immune cells, leading to deleterious proinflammatory cytokine production.