Diseases caused by silica: mechanisms of injury and disease development

Abstract

While silica particles are considered to be fibrogenic and carcinogenic agents, the mechanisms responsible are not well understood. This article summarizes literature on silica-induced accelerated silicosis, chronic silicosis, silico-tuberculosis, bronchogenic carcinoma, and immune-mediated diseases. This article also discusses the generation of reactive oxygen species (ROS) that occurs directly from the interaction of silica with aqueous medium and from silica-stimulated cells, the molecular mechanisms of silica-induced lung injuries with focus on silica-induced NF-kappaB activation, including its mechanisms, possible attenuation and relationship to silica-induced generation of cyclooxygenase II and TNF-alpha. Silica-induced AP-1 activation, protooncogene expression, and the role of ROS in these processes are also briefly discussed.