Elevated TRAF4 expression impaired LPS-induced autophagy in mesenchymal stem cells from ankylosing spondylitis patients

A combination of bacterial infection and genetic factors may lead to development of ankylosing spondylitis (AS). The pathogenesis of AS, a form of spinal arthritis that causes fusion of vertebrae, is poorly understood; genetic mutations and bacterial infection have both been proposed. Huiyong Shen, Yanfeng Wu, and coworkers at the Sun Yat-sen Memorial Hospital, Guangzhou, China investigated how bacterial infection might trigger changes that lead to AS. They examined mesenchymal stem cells (MSCs), which can turn into bone-producing cells. They found that when MSCs from AS patients were exposed to lipopolysaccharide, a substance found in the membranes of many pathogenic bacteria, they did not undergo controlled destruction at the same rate as MSCs from healthy donors. The researchers traced the difference to two proteins, further study of which may clarify the pathogenesis of AS.